Cut-Off Lows, Severe Weather, and the Three Amigos
Thursday, May 23rd, 2013
Snow in May? Thanks to the National Weather Service out of Missoula, MT for the picture below out of Drummond, MT. The elevation here is around 4000ft. – there have been some impressive tallies so far.
Snow Reports So Far…
Here are some of the reports of snow so far in Montana.
Cover Your Tomatoes!
Clear skies, light winds and dry air will allow temps to drop down into the frosty category by early Friday morning. Don’t forget to cover your tomatoes if you live in parts of Wisconsin and Michigan tonight!
Slow Moving Lows
The snow in the Northwest and the severe weather across the eastern two-thirds of the nation since last week is the result of two slow moving low pressure systems. The image below shows the large and lazy lows taking up residence now in the Northwest and in the Northeast.
The slow moving low pressure system hanging out over the Northeast is the same low pressure system responsible for much of the national precipitation over the last 7 days across the country. Take a look at some of the radar estimated rainfall and note how there are several pockets of 2″ to 4″+!! Although some of this moisture came with severe weather, the silver lining is that we are seeing the drought ease in many spots.
Sudden Spike in Severe Weather
2013 has a whole so far, has been a bit quite in terms of severe weather. Because of the slow moving low pressure system mentioned above, we’ve seen a sudden spike in severe weather including tornadoes! According to Hamweather.com, since last Thursday, there have been nearly 3,000 reports of hail, high wind and/or tornadoes!
2013 Tornado Drought Continues
May is typically the most active month for tornadoes with nearly 300 on average across the nation. May 2013 has been fairly quiet until just recently across the middle part of the country. According the the Storm Prediction Center, thru May 22nd, there have only been 342 PRELIMINARY tornado reports across the nation. On average, the U.S. typically sees nearly 750 tornado reports by this date!
The large and lethargic low in the Northwest will be responsible for additional active weather over the coming days as it slowly wobbles east. The image below suggests the precipitation potential through early next week! Thunderstorm potential in the middle part of the country could bring 2″ to 3″+ to some around the Midwest by early next week.
The U.S. Drought Monitor released it’s latest outlook today with a number of areas seeing improvements thanks to the recent heavy rainfall.
“Weather Summary: For several days in mid-May, corn planting and other Midwestern fieldwork accelerated in advance of a developing storm. Producers planted 43% of the U.S. corn crop during the week ending May 19, tying a weekly record set from May 4-10, 1992. However, heavy rain eventually overspread the northern Plains and Midwest, halting planting progress but providing further drought relief or eradication. The same storm responsible for the rain in the north-central U.S. contributed to a multi-day severe weather outbreak. Iowa’s longest stretch without a tornado (359 days from May 25, 2012, to May 18, 2013) ended when several twisters were spotted on May 19. Previously, Iowa’s longest spell of tornado-free weather lasted 355 days in 1955-56. One day after Iowa’s tornadoes, tragedy struck Moore, Oklahoma, on May 20 in the form of a devastating EF-5 twister—the nation’s first category five event since a similarly powerful tornado struck El Reno, Oklahoma, on May 24, 2011.
Several days of warmth preceded the storm across the western and central U.S. On May 14, a phenomenal surge of heat reached the central Plains and western Corn Belt, resulting in several monthly record highs and widespread readings above 100°F. Later, triple-digit heat developed and persisted in the south-central U.S. In addition, rainfall largely bypassed the southern High Plains, resulting in further deterioration in the condition of rangeland, pastures, and winter wheat. Hot, mostly dry weather also prevailed from California into the Southwest. Farther north, however, scattered showers provided beneficial moisture for crops and pastures in the Northwest. More significant precipitation dampened the northern Intermountain West, particularly across portions of Wyoming and southern Montana.”
Severe Threat Thursday
The Storm Prediction Center has issued a MODERATE RISK of severe weather for parts of Texas. Surrounding areas are under a SLIGHT RISK including Dallas/Ft. Worth. There is also a SLIGHT RISK of severe weather in the Northeast. Keep in mind that these threat areas will change as the day moves on…
Severe Threat Friday
The SPC has also issued a SLIGHT RISK of severe weather for Friday as the next boundary sets up across the Central Plains.
MEAN UPPER RIDGE WILL REMAIN ANCHORED OVER THE MIDDLE OF THE CONUS THROUGH THE DAY2 PERIOD. WHILE EMBEDDED SHORT-WAVES WILL ROTATE INTO THE BASE OF THE WRN U.S. TROUGH AND EJECT NEWD…IT APPEARS THE PRIMARY INFLUENCE OF THESE FEATURES WILL BE NOTED ACROSS THE GREAT BASIN INTO THE NRN ROCKIES…WELL WEST OF THE HIGH PLAINS. EVEN SO…FAVORABLE LEE TROUGHING SHOULD ENCOURAGE A MOISTENING BOUNDARY LAYER ACROSS THE HIGH PLAINS AND SFC DEW POINTS IN THE 50S SHOULD EASILY BE TRANSPORTED ACROSS WRN KS INTO THE NEB PANHANDLE. STRONG BOUNDARY LAYER HEATING IS ANTICIPATED ACROSS SERN WY/ERN CO FRIDAY AFTERNOON AND THIS WILL PROVE INSTRUMENTAL IN CONVECTIVE DEVELOPMENT NEAR/JUST EAST OF PALMER DIVIDE SFC LOW THAT IS EXPECTED TO MIGRATE INTO NERN CO DURING THE EVENING. FAVORABLE UPSLOPE FLOW AND SFC HEATING SHOULD PROVE ADEQUATE IN AT LEAST ISOLATED SUPERCELLS BENEATH MODEST SWLY FLOW ALOFT…ON THE ORDER OF 35KT AT 500MB. LARGE HAIL IS EXPECTED WITH THESE STORMS AND IF DEW POINTS CAN RISE INTO THE UPPER 50S CLOUD BASES SHOULD BE ADEQUATELY LOW AND SUPPORTIVE OF TORNADOES. FARTHER SOUTH…MUCH WEAKER FLOW IS EXPECTED ACROSS THE SRN PLAINS WHERE SFC-6KM DEEP LAYER SHEAR SHOULD BE ON THE ORDER OF 15KT. IT/S NOT ENTIRELY CLEAR HOW CONVECTION WILL EVOLVE ACROSS THIS REGION BUT SFC HEATING BENEATH MID LEVEL WEAKNESS/COOLER MID LEVEL TEMPERATURES FAVOR A FEW STRONG STORMS…ESPECIALLY GIVEN THE HIGHER DEW POINTS/INSTABILITY. HAIL IS THE PRIMARY THREAT WITH THE MORE ROBUST ACTIVITY.
A FEW TSTMS MAY DEVELOP ACROSS THE CNTRL/SRN PENINSULA DURING THE HEAT OF THE DAY AND ALONG NW-SE ORIENTED CONFLUENCE ZONE ACROSS SERN TX INTO SRN LA. CONVECTION ACROSS BOTH REGIONS SHOULD EVOLVE WITHIN AN ENVIRONMENT SUPPORTIVE OF GUSTY WINDS OR SMALL HAIL BUT LITTLE CHANCE FOR MEANINGFUL ORGANIZATION.
Memorial Day Outlook
Here’s a quick look at the Memorial Day… It appears the most unsettled weather will stay across the High Plains to the Middle Mississippi Valley. The same boundary that is expected to kick out thundery weather across the Central and Southern Plains today and tomorrow is the same boundary that we’ll have plaguing the areas mentioned above.
Memorial Day Temps
If you have big plans to fire up the ol’ BBQ on Memorial Day, temps might be a bit cool in spots across the country especially in the Northwest and Northeast.
Highs From Normal
Here’s a peek at highs from normal on Memorial Day and it appears that most spots will be running a little bit cooler than average!
Atlantic Hurricane Season Starts June 1st
Are you kidding me?? Believe it or not, the Atlantic Hurricane Season starts a week from this Saturday! According to NOAA, we are expected to have a fairly active season.
In its 2013 Atlantic hurricane season outlook issued today, NOAA’s Climate Prediction Center is forecasting an active or extremely active season this year. For the six-month hurricane season, which begins June 1, NOAA’s Atlantic Hurricane Season Outlook says there is a 70 percent likelihood of 13 to 20 named storms (winds of 39 mph or higher), of which 7 to 11 could become hurricanes (winds of 74 mph or higher), including 3 to 6 major hurricanes (Category 3, 4 or 5; winds of 111 mph or higher). These ranges are well above the seasonal average of 12 named storms, 6 hurricanes and 3 major hurricanes.
Here are some of the factors that are leading to their active forecast:
“Three climate factors that strongly control Atlantic hurricane activity are expected to come together to produce an active or extremely active 2013 hurricane season. These are:
1.) A continuation of the atmospheric climate pattern, which includes a strong west African monsoon, that is responsible for the ongoing era of high activity for Atlantic hurricanes that began in 1995;
2.) Warmer-than-average water temperatures in the tropical Atlantic Ocean and Caribbean Sea.
3.) El Niño is not expected to develop and suppress hurricane formation.”
Thanks for checking in, have a great weekend ahead
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The Three Amigos