BLIND SPOT – RADAR GAP – MODERATE SNOW THIS MORNING March 28, 2011
Posted by mikeheard in Uncategorized.1 comment so far
On KBZK/KXLF TV we show you and discuss the radar gap frequently and is one of the most frustrating aspects about predicting weather here in SW Montana.
A classic example occurred this morning between Butte and Bozeman. On radar absolutely NOTHING is shown to emphasize the intensity of the snow. Here is a picture of the NWS radar and a close up radar shot from the Storm Tracker Weather computer.
NWS Radar at 8:30am March 28, 2011
STORMTRACKER Doppler Radar at 8:15am March 28, 2011
Ok, now look at web cam pictures from the ICAM network and MDOT network over the mountain passes.
Bozeman ICAM March 28th, 2011
MDOT Bozeman Pass 8:30am March 28, 2011
My backyard, up to 3″ of snow in most areas I measured and a few 4″ measurements as well.
Distance between radar sites is great. Billings NWS to Great Falls NWS to Missoula NWS to Pocatello, ID NWS are the 4 nexrad 88D radar sites that cover SW Montana. The problem is the vast distance. As a radar beam travels away from it’s origin the higher and higher the beam travels. The other hurtle is the numerous mountain ranges that block the lowest radar beams.
So what do we use to offset this radar gap, satellite imagery and surface observations with the numerous web cameras.
Enhanced Infra Red Satellite Image
Analyzing the above infra red satellite image you can see a very small area of red and pink over northern Gallatin County. The colors tell us that the cloud tops are rather high and the thus there is more moisture within that region. I find it amazing that such a small wave of moisture can dump that much moisture.
I measured 3″ to 4″ of snow around 8:30am this morning on my deck.
April Forecast – Temperature & Precipitation for NW March 23, 2011
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April Temperature Outlook
CPC April Precipitation Forecast
A weakening La Nina continues to impact the weather patterns across the western US through March with cooler and wetter than normal conditions for most areas in Montana.
Hardest hit regions in the state are the far northern half of Montana with above normal snowpack at all levels and a serious threat of flooding once all that snow melts up north.
Typically, in a normal season, snowpack will continue to accumulate up to about April 15th and thereafter the accumulation to melting ratio’s start to favor more melting than accumulating. Looking at the Climate Predicition Center long range forecast for April (graphics above) we are likely to see more of the same, below normal temperatures and above normal precipitation across Montana. There is a 40% to 50% chance that average temperatures for April will be below normal and a 30% to 40% chance that we will experience above normal precipitation.
February Ranked 17th Warmest on Record March 15, 2011
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February Ranked 17th Warmest on Record
March 15, 2011
This year, the globe experienced the 17th warmest February since record keeping began in 1880, as the climate phenomenon La Niña continued to be a significant factor. Last month’s average Arctic sea ice extent tied with 2005 as the smallest extent for February in its 32-year period of record.
The monthly analysis from NOAA’s National Climatic Data Center is part of the suite of climate services NOAA provides government, business and community leaders so they can make informed decisions.
Global Temperature Highlights – February
- The combined global land and ocean average surface temperature for February 2011 was the 17th warmest on record at 54.62 F (12.50 C), which is 0.72 F (0.40 C) above the 20th century average of 53.9 F (12.1 C). The margin of error associated with this temperature is +/- 0.18 F (0.10 C).
- Separately, the global land surface temperature was 0.92 F (0.51 C) above the 20th century average of 37.8 F (3.2 C), which tied for the 28th warmest February on record. The margin of error is +/- 0.56 F (0.31 C). Warmer-than-average conditions occurred across most of Asia, central Africa, northern Alaska and southern Greenland. Cooler-than-average regions included Eastern Europe, western Russia, eastern Siberia and the western United States.
- The February global ocean surface temperature was 0.65 F (0.36 C) above the 20th century average of 60.6 F (15.9 C), making it the 10th warmest February on record. The margin of error is +/- 0.13 F (0.07 C). The warmth was most pronounced across the northern Pacific Ocean, the tropical Atlantic Ocean and part of the North Atlantic near Greenland and Canada.
Global Temperature Highlights – December 2010 – February 2011
- The combined global land and ocean average surface temperature for Northern Hemisphere winter (December 2010 – February 2011) was 0.70 F (0.39 C) above the 20th century average of 53.8 F (12.1 C), making it the 16th warmest on record. The margin of error is +/- 0.16 F (0.09 C).
- The December 2010 – February 2011 worldwide land surface temperature was 0.81 F (0.45 C) above the 20th century average of 37.8 F (3.2 C) — the 26th warmest such period on record. The margin of error is +/- 0.32 F (0.18 C). Warmer-than-average conditions were particularly felt across eastern Canada, southern Greenland and northern Siberia. Cooler-than-average regions included Eastern Europe, western Russia and Mongolia.
- The global ocean surface temperature for December 2010 – February 2011 was 0.65 F (0.36 C) above the 20th century average of 60.5 F (15.8 C) and tied for the 10th warmest such period on record. The margin of error is +/-0.13 F (0.07 C). The warmth was most pronounced across the northern Pacific Ocean, the tropical Atlantic Ocean, and the North Atlantic, near Greenland and Canada.
- La Niña conditions weakened in February, although sea-surface temperatures remained below normal across the central and eastern equatorial Pacific Ocean. According to NOAA’s Climate Prediction Center, La Niña will continue to have global impacts for the next several months, but neither La Niña nor El Niño are expected to affect the region by June.
Polar Sea Ice and Precipitation Highlights
- The average Arctic sea ice extent for February was 5.54 million square miles (14.36 million square km), which is 8.2 percent below average. This ties with February 2005 as the smallest February Arctic sea ice extent since records began in 1979 and is the third consecutive month with record low Arctic ice extent.
- For the winter period, the Northern Hemisphere snow cover extent over land averaged 760,000 square miles (1.98 million square km) above average, ranking as the third largest seasonal snow cover extent on record behind the winters of 1977–1978 and 2009–2010. The North American season snow cover extent was the third largest on record, while Eurasia’s was fourth largest.
- Average rainfall across Australia was 76 percent above average during February, making it the second wettest February on record behind 2000. Rainfall in South Australia was more than four times above average, the wettest February on record for the state. The summer period (December 2010 – February 2011) was the second wettest summer on record for Australia.
Scientists, researchers and leaders in government and industry use NOAA’s monthly reports to help track trends and other changes in the world’s climate. This climate service has a wide range of practical uses, from helping farmers know what and when to plant, to guiding resource managers with critical decisions about water, energy and other vital assets.
NOAA’s mission is to understand and predict changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Visit us on Facebook.
* Included in this report: Based on requests from our users, NOAA is now making it easier to find information in its global State of the Climate report about margins of error associated with its global temperature calculations. NCDC previously displayed this information in certain graphics associated with the report, but it will now publish these ranges in the form of “plus or minus” values associated with each monthly temperature calculation. These values are calculated using techniques published in peer-reviewed scientific literature. More information.
Japan Earthquake and Tsunami March 11, 2011
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http://www.youtube.com/watch?v=PBZGH3yieLc
http://cnettv.cnet.com/av/video/cbsnews/atlantis2/cbsnews_player_embed.swf
HYDROLOGIC OUTLOOK March 10, 2011
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GUS75 KTFX 102231
ESFTFX
092231-
WATER SUPPLY OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
331 PM MST THU MAR 10 2011
…MONTANA WATER SUPPLY OUTLOOK AS OF MARCH 2011…
MONTANA WATER SUPPLY FORECAST ISSUED BY THE NATIONAL WEATHER SERVICE OFFICE IN GREAT FALLS IN COOPERATION AND COORDINATION WITH THE NATIONAL WEATHER SERVICE OFFICE IN MISSOULA AND THE NATURAL RESOURCES CONSERVATION SERVICE…USDA.
THE WATER SUPPLY OUTLOOK FOR THE 2011 SUMMER SEASON PROJECTS WATER SUPPLIES EAST AND WEST OF THE CONTINENTAL DIVIDE TO BE ABOVE AVERAGE. THESE FORECASTS ASSUME NEAR NORMAL MOISTURE AND RUNOFF CONDITIONS FOR MARCH THROUGH JULY AND DO NOT ACCOUNT FOR MUCH BELOW AVERAGE…70 PERCENT OR LESS…OR ABOVE AVERAGE…110 PERCENT OR MORE…SNOWMELT OR SPRING RAINS.
FEBRUARY WAS ANOTHER MONTH OF WINTER WEATHER FOR MONTANA.
TEMPERATURES ACROSS THE STATE AVERAGED OVER 8 DEGREES BELOW
AVERAGE…MAKING FEBRUARY 2011 THE COOLEST SINCE 2001 AND THE 24TH COOLEST ON RECORD FOR THE STATE. PRECIPITATION AND SNOWFALL CAME IN ABOVE AVERAGE…IT WAS THE 13TH WETTEST OF RECORD AND THE THIRD CONSECUTIVE MONTH OF ABOVE NORMAL PRECIPITATION. HEAVIEST AMOUNTS FELL WEST OF THE DIVIDE AND OVER PORTIONS OF CENTRAL MONTANA.
BILLINGS…GLASGOW…GREAT FALLS…HELENA…LIVINGSTON AND MISSOULA ALL SET ONE OR MORE DAILY RECORDS FOR TOTAL PRECIPITATION AND/OR TOTAL SNOWFALL. GREAT FALLS ALSO SET A RECORD FOR THEIR SNOWIEST FEBRUARY. THE HIGHEST AMOUNTS OF PRECIPITATION WERE 7.91 INCHES AT
MULLAN PASSAND 10.1 INCHES AT STAHL PEAK SNOTEL NEAR LINCOLN.
SNOWPACK…
MARCH 1 MOUNTAIN SNOWPACK CONTINUES THE TREND OF THE PREVIOUS THREE MONTHS COMING IN ABOVE AVERAGE AND WELL ABOVE LAST YEAR AT THIS TIME. THE SNOW WATER CONTENT ON MARCH 1 REPRESENTS ABOUT 82 PERCENT OF THE SEASONAL SNOWFALL WEST OF THE DIVIDE AND 75 PERCENT OF THE SEASONAL SNOWFALL EAST OF THE DIVIDE.
MOUNTAIN SNOWPACK AS OF MARCH 1…
PERCENT OF PERCENT OF
AVERAGE LAST YEAR
STATEWIDE 113 165
WEST OF THE CONTINENTAL DIVIDE 115 178
EAST OF THE CONTINENTAL DIVIDE 110 153
PERCENT OF PERCENT OF JANUARY
AVERAGE LAST YEAR PERCENT CHANGE
COLUMBIA BASIN 115 178 +2
MISSOURI BASIN 111 148 -2
YELLOWSTONE BASIN 108 158 +3
ST. MARY BASIN 111 158 +3
ST. MARY/MILK BASIN 144 154 -11
PRECIPITATION…
MOUNTAIN PRECIPITATION AVERAGES FOR FEBRUARY BY BASIN…
WEST OF THE CONTINENTAL DIVIDE 106
EAST OF THE CONTINENTAL DIVIDE 105
MOUNTAIN AND VALLEY PRECIPITATION AVERAGES FOR FEBRUARY…
PERCENT OF PERCENT OF
AVERAGE LAST YEAR
STATEWIDE 110 229
WEST OF THE CONTINENTAL DIVIDE 110 283
EAST OF THE CONTINENTAL DIVIDE 110 193
MOUNTAIN AND VALLEY PRECIPITATION AVERAGES FOR THE WATER YEAR…
PERCENT OF PERCENT OF
AVERAGE LAST YEAR
STATEWIDE 113 145
WEST OF THE CONTINENTAL DIVIDE 114 162
EAST OF THE CONTINENTAL DIVIDE 112 131
CALENDAR YEAR 2011 AND WATER YEAR 2011 PERCENT OF NORMAL
PRECIPITATION FOR SELECTED CITIES ARE SHOWN BELOW…
PERCENT OF NORMAL PERCENT OF NORMAL
CALENDAR YEAR 2011 WATER YEAR 2011
CITY JAN 1 TO FEB 28 OCT 1 TO FEB 28
BILLINGS 69 109
BOZEMAN 37 85
BUTTE 70 86
CUT BANK M M
DILLON 13 114
GLASGOW 400 221
GREAT FALLS 187 177
HAVRE 176 161
HELENA 127 148
KALISPELL 135 132
LEWISTOWN 73 106
MILES CITY 69 54
MISSOULA 198 157
RESERVOIRS…
MAJOR RESERVOIR STORAGE AS OF MARCH 1
PERCENT OF PERCENT OF
AVERAGE LAST YEAR
STATEWIDE 111 109
WEST OF THE CONTINENTAL DIVIDE 133 93
EAST OF THE CONTINENTAL DIVIDE 105 115
PERCENT OF NORMAL RESERVOIR STORAGE AS OF MARCH 1 FOR SELECTED
RESERVOIRS…
RESERVOIR PERCENT OF NORMAL
MAR 1 MAR 1
2011 2010
BIGHORN RESERVOIR 103 112
CANYON FERRY RESERVOIR 94 105
CLARK CANYON RESERVOIR 113 114
FLATHEAD LAKE 105 98
FORT PECK LAKE 115 85
FRESNO RESERVOIR 192 99
MARCH 9…164 PERCENT
GIBSON RESERVOIR 36 52
HEBGEN RESERVOIR 106 108
HUNGRY HORSE RESERVOIR 115 127
LAKE ELWELL / TIBER RESERVOIR 115 109
LAKE KOOCANUSA 124 178
LAKE SHERBURNE 237 133
LIMA RESERVOIR 133 114
NELSON RESERVOIR 124 114
PISHKIN RESERVOIR 109 108
SWIFT RESERVOIR 79 105
WILLOW CREEK RESERVOIR 126 125
STREAMFLOW…
STREAMFLOW FORECAST FOR THE PERIOD APRIL 1 THROUGH JULY 31…ASSUMING
NORMAL PRECIPITATION
STATEWIDE 110
WEST OF THE CONTINENTAL DIVIDE 115
EAST OF THE CONTINENTAL DIVIDE 106
BELOW ARE AVERAGED RIVER BASIN RUNOFF FORECAST SUMMARIES FOR THE PERIOD APRIL THROUGH SEPTEMBER. THESE FORECASTS ASSUME NEAR NORMAL SPRING CONDITIONS AND DO NOT ACCOUNT FOR WELL BELOW AVERAGE…70 OR LESS…OR ABOVE AVERAGE…110 OR MORE…SNOWMELT OR SPRING RAIN.
FORECASTS FOR RIVERS AND SITES WEST OF THE CONTINENTAL DIVIDE ARE PROVIDED BY THE NORTHWEST RIVER FORECAST CENTER IN
PORTLAND…OREGON. FORECASTS FOR RIVERS AND SITES EAST OF THE
CONTINENTAL DIVIDE ARE FROM THE MISSOURI BASIN RIVER FORECAST CENTER IN PLEASANT HILL…MISSOURI. ALL FORECASTS ARE IN COOPERATION AND COORDINATION WITH NATURAL RESOURCES CONSERVATION SERVICE…USDA.
MOST
PROBABLE REASONABLE REASONABLE
FORECAST MAXIMUM MINIMUM
PERIOD /PCT AVG/ /PCT AVG/ /PCT AVG/
COLUMBIA RIVER BASIN
KOOTENAI RIVER
LIBBY RESVR INFLOW APR-SEP 105 126 84
CLARK FORK
ABOVE BLACKFOOT RIVER APR-SEP 111 165 57
ABOVE MISSOULA APR-SEP 113 146 80
BELOW MISSOULA APR-SEP 110 137 84
ST. REGIS APR-SEP 112 147 76
NEAR PLAINS APR-SEP 114 139 89
BLACKFOOT RIVER
NEAR BONNER APR-SEP 122 158 85
BITTERROOT RIVER
AT MOUTH APR-SEP 106 128 84
NORTH FORK FLATHEAD RIVER
NEAR COLUMBIA FALLS APR-SEP 113 132 94
MIDDLE FORK FLATHEAD RIVER
NEAR WEST GLACIER NR APR-SEP 116 134 98
SOUTH FORK FLATHEAD RIVER
HUNGRY HORSE RES INFLOW APR-SEP 121 146 97
FLATHEAD RIVER
COLUMBIA FALLS APR-SEP 117 139 95
FLATHEAD LAKE INFLOW APR-SEP 117 140 93
SASKATCHEWAN RIVER BASIN
ST. MARY RIVER
BABB NR APR-SEP 110 126 94
MISSOURI RIVER BASIN
RED ROCK RIVER
LIMA RES INFLOW APR-SEP 93 133 54
BEAVERHEAD RIVER
CLARK CANYON INFLOW APR-SEP 85 144 34
BARRETTS APR-SEP 71 133 29
RUBY RIVER
RUBY RESERVOIR INFLOW APR-SEP 102 135 69
BIG HOLE RIVER
NEAR MELROSE APR-SEP 108 142 74
MADISON RIVER
HEBGEN RES INFLOW APR-SEP 98 114 82
ENNIS RESERVOIR INFLOW APR-SEP 93 112 74
GALLATIN RIVER
NEAR GALLATIN GATEWAY APR-SEP 103 125 81
LOGAN APR-SEP 106 140 72
MISSOURI RIVER
TOSTON APR-SEP 99 132 67
FORT BENTON APR-SEP 101 134 68
VIRGELLE APR-SEP 100 134 67
NEAR LANDUSKY APR-SEP 100 134 67
BELOW FORT PECK DAM APR-SEP 89 117 61
SHEEP CREEK
WHITE SULPHUR SPRINGS APR-SEP 125 160 92
SUN RIVER
GIBSON RES INFLOW APR-SEP 110 132 88
MARIAS RIVER
NEAR SHELBY APR-SEP 106 149 63
MUSSELSHELL RIVER
HARLOWTON APR-SEP 120 196 43
MILK RIVER
WESTERN CROSSING APR-SEP 130 179 81
EASTERN CROSSING APR-SEP 161 233 89
YELLOWSTONE RIVER
YELLOWSTN LK OUTLT…WY APR-SEP 105 124 86
CORWIN SPRINGS APR-SEP 112 130 93
NEAR LIVINGSTON APR-SEP 110 130 90
BILLINGS APR-SEP 107 133 80
MILES CITY APR-SEP 103 129 76
NEAR SIDNEY APR-SEP 103 130 77
BOULDER RIVER
BIG TIMBER APR-SEP 106 130 83
STILLWATER RIVER
NEAR ABSAROKEE APR-SEP 91 113 70
CLARKS FORK YELLOWSTONE RIVER
NEAR BELFRY APR-SEP 105 124 87
LITTLE BIGHORN RIVER
NEAR HARDIN APR-SEP 97 133 60
TONGUE RIVER
TONGUE RIVER RES INFLOW APR-SEP 88 134 42
POWDER RIVER
MOORHEAD APR-SEP 98 150 47
LOCATE APR-SEP 98 154 42
DEFINITIONS
MOST PROBABLE FORECAST…GIVEN THE CURRENT HYDROMETEOROLOGICAL
CONDITIONS TO DATE…THIS IS THE BEST ESTIMATE OF WHAT THE ACTUAL RUNOFF VOLUME WILL BE THIS SEASON.
REASONABLE MAXIMUM FORECAST…GIVEN CURRENT HYDROMETEOROLOGICAL
CONDITIONS…THE SEASONAL RUNOFF THAT HAS A TEN (10) PERCENT CHANCE OF BEING EXCEEDED.
REASONABLE MINIMUM FORECAST…GIVEN CURRENT HYDROMETEOROLOGICAL
CONDITIONS…THE SEASONAL RUNOFF THAT HAS A NINETY (90) PERCENT
CHANCE OF BEING EXCEEDED.
SURFACE WATER SUPPLY INDEX…
THE SURFACE WATER SUPPLY INDEX…SWSI…IS A MEASURE OF AVAILABLE SURFACE WATER AVAILABILITY FOR THE SPRING AND SUMMER MONTHS. WATER USERS WHO RELY ON MOUNTAIN PRECIPITATION CAN USE THE INDEX TO EVALUATE SEASONAL SURFACE WATER SUPPLIES. THE SWSI ACCOUNTS FOR MOUNTAIN SNOWPACK…MOUNTAIN PRECIPITATION…
STREAMFLOW…RESERVOIR STORAGE AND SOIL MOISTURE. SWSI VALUES ARE CALCULATED FOR 54 BASINS IN MONTANA. SWSI VALUES ARE PROVIDED BY THE NATURAL RESOURCES CONSERVATION SERVICE…USDA.
NUMBER OF BASINS
SWSI RATING SURFACE WATER CONDITION 2011 2010
-3.0 TO -4.0 EXTREMELY DRY 0 14
-2.0 TO -2.9 MODERATELY DRY 0 13
-1.0 TO -1.9 SLIGHTLY DRY 0 13
-0.9 TO +0.9 NEAR AVERAGE 11 7
+1.0 TO +1.9 SLIGHTLY WET 22 1
+2.0 TO +2.9 MODERATELY WET 14 0
+3.0 TO +4.0 EXTREMELY WET 4 1
NOT AVAILABLE 1 3
VALUES FOR SPECIFIC BASINS AS OF MAR 1 2011 AND MAR 1 2010 ARE LISTED
BELOW…
SWSI SWSI
BASIN 2011 2010
TOBACCO RIVER 1.7 -3.2
KOOTENAI FT. STEELE TO LIBBY DAM 1.5 -2.9
KOOTENAI RIVER BELOW LIBBY DAM 2.9 -0.1
FISHER RIVER 1.5 -2.8
YAAK RIVER 0.8 -3.4
NORTH FORK FLATHEAD RIVER 2.3 -3.2
MIDDLE FORK FLATHEAD RIVER 2.1 -3.2
SOUTH FORK FLATHEAD RIVER 3.7 -0.4
FLATHEAD RIVER AT COLUMBIA FALLS 2.7 -2.4
SWAN RIVER 3.4 -1.2
FLATHEAD RIVER AT POLSON 2.4 -2.9
MISSION VALLEY NA -3.5
LITTLE BITTERROOT RIVER 1.3 -3.6
CLARK FORK RIVER ABOVE MILLTOWN 1.5 -2.2
BLACKFOOT RIVER 2.4 -2.9
BITTERROOT RIVER 1.4 -3.4
CLARK FORK RIVER BELOW BITTERROOT RIVER 1.8 -3.0
CLARK FORK RIVER BELOW FLATHEAD RIVER 2.2 -2.9
BEAVERHEAD RIVER 0.8 -0.8
RUBY RIVER 1.1 -1.7
BIG HOLE RIVER 1.2 -1.3
BOULDER RIVER (JEFFERSON) 0.2 -1.7
JEFFERSON RIVER 1.8 -0.7
MADISON RIVER 0.3 -1.8
GALLATIN RIVER 1.1 -1.4
MISSOURI RIVER ABOVE CANYON FERRY 0.5 -1.6
MISSOURI RIVER BELOW CANYON FERRY 0.1 -1.5
SMITH RIVER 2.6 -0.2
SUN RIVER 1.4 -3.6
TETON RIVER 1.7 -1.4
BIRCH/DUPUYER CREEKS 1.3 -2.4
UPPER JUDITH RIVER 3.5 3.4
MARIAS RIVER ABOVE TIBER 0.6 NA
MARIAS RIVER BELOW TIBER 2.7 NA
MUSSELSHELL RIVER 2.4 1.2
MISSOURI RIVER ABOVE FT. PECK 0.9 NA
MISSOURI RIVER BELOW FT. PECK 1.1 -1.6
ST. MARY RIVER 2.5 -2.9
MILK RIVER 3.1 -0.5
DEARBORN RIVER NEAR CRAIG 2.0 -3.0
YELLOWSTONE RIVER ABOVE LIVINGSTON 1.7 -3.2
SHIELDS RIVER 2.1 -0.9
BOULDER RIVER (YELLOWSTONE) 2.4 -2.9
STILLWATER RIVER -0.1 -3.1
ROCK/RED LODGE CREEKS -0.9 -1.0
CLARKS FORK RIVER 1.5 -3.0
YELLOWSTONE RIVER ABOVE BIGHORN RIVER 1.5 -3.1
BIGHORN RIVER BELOW BIGHORN LAKE 0.4 -1.7
LITTLE BIGHORN RIVER 1.2 -2.7
YELLOWSTONE RIVER BELOW BIGHORN RIVER 1.0 -2.5
TONGUE RIVER 1.0 -2.1
POWDER RIVER 1.1 -1.9
OUTLOOK…
THE OUTLOOK FOR MARCH INDICATES THAT THERE IS A 50 TO 60 PERCENT CHANCE TEMPERATURES WILL BE BELOW AVERAGE WEST OF THE DIVIDE…AND A 40 TO 50 PERCENT CHANCE TEMPERATURES WILL BE BELOW AVERAGE EAST OF THE DIVIDE. THERE IS A 40 TO 50 PERCENT CHANCE PRECIPITATION WILL BE ABOVE AVERAGE OVER WEST…SOUTHWEST AND THE FAR NORTHEAST CORNER OF MONTANA. THERE IS A 33 TO 40 PERCENT CHANCE PRECIPITATION WILL BE ABOVE AVERAGE FROM NORTH CENTRAL TO SOUTHEAST MONTANA.
FOR THE PERIOD APRIL THROUGH JUNE…THERE IS A 40 TO 50 PERCENT
CHANCE TEMPERATURES WILL BE BELOW AVERAGE OVER CENTRAL AND NORTHERN MONTANA. THERE IS A 33 TO 40 PERCENT CHANCE TEMPERATURES WILL BE BELOW AVERAGE ACROSS SOUTHERN MONTANA. FOR PRECIPITATION…FORECAST TOOLS SHOW NO TENDENCIES TOWARD WETTER OR DRIER FOR THIS PERIOD. AS A RESULT…THERE ARE EQUAL CHANCES PRECIPITATION WILL BE ABOVE…BELOW OR NEAR AVERAGE.
THE NEXT WATER SUPPLY OUTLOOK FOR 2011 WILL BE ISSUED BY APRIL 15.
$$
A Look At The Winter Season 2010-2011 for Montana March 6, 2011
Posted by mikeheard in Uncategorized.add a comment
The winter season of 2010-2011 was greatly influenced by a La Nina event in the equatorial pacific with much colder than normal sea surface temperatures. This La Nina event was a stronger event than the La Nina in the 2008-2009 winter season. Moderate to Strong La Nina episodes typically lock Montana into a colder and wetter winter weather pattern. Also the stronger the event the more likely it is to redevelop again, not a guarantee, but La Nina’s typically run in back to back years. The data is showing the current La Nina weakening and should be in a neutral state by late spring or early summer and by late summer we should have enough data to determine if La Nina conditions will redevelop or not.
Looking back at this winter season the data is showing that overall Montana endured one of the coldest winter season in many years. Listed below is the average monthly temperature from November to February and overall the data shows well below average temperatures with the exception of January for southwest Montana.
Average Monthly Temperatures winter season 2010-2011
……………….Butte Bozeman Helena Dillon………………………
November -2.5 -3.1 -3.5 -6 COLD
December -.5 -2.2 -3.3 -4.2 COLD
January 3.6 4.5 6.3 -.7 MILD
February -5.2 -6.4 -5.1 -8 VERY COLD
The month of February-2011 across Montana was Extremely Cold especially for the northern half of the state and far eastern cities. February avg temperatures: Great Falls -9.5, Cut Bank -10.6, Havre -8.9, Glasgow -10.9, Miles City -10.5, Billings -9.6, Bozeman -6.4, Dillon -8, Lewistown -8.7, Missoula -6, Kalispell -5.8, Butte -5.2, Helena -5.1. When we analyze climate data and see average temperatures vary a few degrees is not unusual, however, when we see average temperatures vary more the 3 to 5 degrees is alarming but when the vary 8 to 12 degrees is exceptional. So most of Montana saw below average temperatures in February -5 to -11 degrees and again that signals an extreme event.
An interesting side note on the winter season was the month of January. Average temperatures for January 2011 saw a complete reversal with above to well above average temperatures. La Nina was still in a very strong state but apparently there were other atmospheric conditions offsetting the normal La Nina effects on Montana during that month. A few record highs were noted within Southwest Montana during January as max values reached the lower to mid 50′s.
Arctic Cold below zero mornings
Gallatin Field
Nov 8 mornings below zero
Dec 9 mornings below zero
Jan 7 mornings below zero
Feb 8 mornings below zero
Total 32 mornings with below zero lows Nov through Feb.
Gallatin Field -10 to -20 Nov to Feb = 15 mornings
Gallatin Field -20 or colder Nov to Feb = 5 mornings and 4 of those in Feb.
Coldest morning low this past winter season 2010-2011 at Gallatin Field -22, Feb. 25th
Butte – Bert Mooney Airport
Nov 7 mornings below zero
Dec 10 mornings below zero
Jan 9 mornings below zero
Feb 10 mornings below zero
Total 36 mornings with below zero lows Nov through Feb.
Bert Mooney Airport -10 to -20 Nov to Feb = 16 mornings
-20 or colder = 6 mornings Nov to Feb and 4 of those where in February.
Coldest morning low at Bert Mooney Airport for the winter season 2010-2011 was -25, February 26th.
The 30 to 90 day forecast continues to bring more of the same with La Nina still controlling the overall weather pattern so colder than normal temperatures will likely persist into the early half of spring. Climate Prediction Center longer range forecast for this summer is showing a complete reversal with above to well above normal temperatures July through September due to the La Nina reaching a neutral state.
This is the time of the year we start to see how the upcoming spring/summer could fair as far as forest fires and/or flooding. The current data shows average to well above average snowpack across the entire state of Montana. The highline and NE counties of Montana has a double threat with colder than normal temperatures and well above normal ground snow which increases the potential for moderate to major flooding this spring. North and South Dakota through Minnesota has a high probability for major flooding as well as the high plains has been inundated with plenty of snow and a colder than normal winter season as well. The rest of Montana has a good chance for minor flooding due to snowmelt especially on those rivers and tributaries that are free flowing or not augmented by reservoir storage.
The next 4 to 6 weeks will determine the severity of spring flooding across the state, if forecasts trends continue with colder than normal temperatures and near normal precipitation flooding will occur in Montana this spring. Hardest hit areas will be the NE and far eastern counties, minor for the rest of Montana with some moderate flooding possible in isolated areas if conditions are just right. One possible weather pattern I am most concerned with is the colder than normal pattern will keep most of the snowpack in place up to the beginning of the rainy season in May. If a warm and very wet pattern where to hit the above normal snowpack flooding probabilities will increase substantially.
I’ll continue to monitor the weather patterns to see how fast the current La Nina weakens to a neutral state, how mountain snowpack data trends develop and we will keep a very close eye on the longer range forecast for this summer to see how the summer fire season could develop. Right now we are most concerned with the increasing possibility of flooding this spring.
