Somewhat Soggy Sunday - Scatter PM Thunder
By Todd Nelson, filling in for Douglas.
I'm beat. I wore myself out yesterday trying to pack in as much outdoor stuff as I could. Maybe Mother Nature is telling me to take it easy today. Cloudier skies and increased rain chances may be ideal napping weather. I see some Zzzs in my future.
Weather maps look active over the next several days. A series of Pacific storms will make the end of April a little more interesting for us. The first storm system will be with us through early next week. However, scattered showers and a few strong rumbles will flirt with southern Minnesota later today.
The next, more impressive storm system moves in by the middle part of next week. The Storm Prediction Center has highlighted Tuesday and Wednesday as potential severe weather outbreak days in the Central U.S. for several days now. It appears that Tuesday will feature the strongest of storms.
Extended rainfall forecasts are suggesting heavier moisture for us through the end of next week. This is good news! May flowers and recently fertilized lawns will be delighted.
Average Low: 41F (Record: 24F set in 1875)
*Daylight gained since winter solstice: ~5hours & 12mins
3.1 Days After Full (Pink) Moon
...SUMMARY... STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON AND EVENING ACROSS PARTS OF OKLAHOMA AND EASTERN KANSAS INTO THE MIDDLE MISSOURI VALLEY TO SOUTHERN MINNESOTA...AND ACROSS PARTS OF SOUTH TEXAS. ...SYNOPSIS... A WELL-DEFINED MID-UPPER-LEVEL SHORTWAVE TROUGH IS EVIDENT ON THE MOST RECENT WATER VAPOR LOOP OVER THE GREAT BASIN...AND THIS FEATURE WILL SHIFT EWD INTO THE CNTRL HIGH PLAINS BY 12Z SUN MORNING. A GENERAL WEAKENING/DEAMPLIFICATION OF THIS SHORTWAVE TROUGH WILL OCCUR WITH EWD PROGRESSION ACROSS THE CNTRL PLAINS AND MID-MO VALLEY...AS AN ASSOCIATED MIDLEVEL LOW LAGS ACROSS SD/NEB. THE PRIMARY AREA OF SFC CYCLOGENESIS WILL INITIALLY OCCUR ACROSS SD...IN VICINITY OF A PREEXISTING QUASI-STATIONARY W-E ORIENTED BOUNDARY ACROSS THE DAKOTAS. A DRYLINE WILL EXTEND SWD FROM THIS FEATURE ACROSS THE CNTRL PORTIONS OF NEB/KS...AND SHOULD SERVE AS ONE FOCUS FOR TSTM DEVELOPMENT DURING THE AFTERNOON. ADDITIONAL TSTMS ARE ALSO LIKELY ALONG/N OF THE QUASI-STATIONARY BOUNDARY EARLY IN THE PERIOD...WITH ADDITIONAL TSTM REDEVELOPMENT POSSIBLE ACROSS THE DAKOTAS INTO THE UPPER MS VALLEY DURING THE AFTERNOON/EVENING. ELSEWHERE...SUBSTANTIAL AMPLIFICATION OF A MID-UPPER-LEVEL TROUGH WILL OCCUR OVER THE WRN CONUS AS A POWERFUL SPEED MAX APPROACHES THE CA COAST. A SRN STREAM IMPULSE MOVING ACROSS NRN MX WILL REACH THE RIO GRANDE VALLEY SUN MORNING AND CONTRIBUTE TO INCREASED CONVECTIVE POTENTIAL OVER SOUTH TX.
...DISCUSSION... CONCERN FOR A MORE ACTIVE SPRINGTIME SEVERE WEATHER PATTERN CONTINUES WITH THIS OUTLOOK ISSUANCE FOR THE CENTRAL AND SOUTHERN PLAINS ON DAY 4/TUESDAY AND INTO THE MID MS VALLEY TO NORTHEAST TX REGION ON DAY 5/WEDNESDAY.
Severe Threat Tuesday, April 26th
...DAY 4/TUESDAY... THE GREATEST THREAT FOR SEVERE WEATHER APPEARS TO BE ON DAY 4/TUE. DETERMINISTIC AND ENSEMBLE GUIDANCE CONTINUES TO BE IN FAIRLY GOOD AGREEMENT...INDICATING INGREDIENTS IN PLACE FOR A POTENTIAL SEVERE WEATHER OUTBREAK ACROSS PORTIONS OF THE SOUTHERN/CENTRAL PLAINS TUESDAY AFTERNOON/EVENING. A STRONG UPPER TROUGH OVER THE WESTERN STATES WILL BECOME NEGATIVELY TILTED WHILE PIVOTING EAST TOWARD THE PLAINS. A 50-60+ KT SOUTHWESTERLY MIDLEVEL JET WILL OVERSPREAD NM INTO WRN TX/OK AND KS BY TUESDAY AFTERNOON. AT THE SURFACE...A LEE CYCLONE WILL DEVELOP OVER EASTERN CO AND SHIFT TO THE EAST/NORTHEAST INTO CENTRAL AND OR NORTHWEST KS. A SHARP DRYLINE WILL EXTEND SOUTH THROUGH SOUTHWEST/SOUTH-CENTRAL KS THROUGH WESTERN OK TO WEST-CENTRAL TX. MEANWHILE...A WARM FRONT SHOULD BE DRAPED ACROSS NRN KS INTO THE MID-MS VALLEY. MODEL VARIABILITY WITH THE PLACEMENT OF THE SURFACE LOW...WARM FRONT AND DRY LINE HAS RESULTED IN WEST AND NORTHWEST EXPANSIONS OF THE 15% AND 30% SEVERE-WEATHER THREAT AREAS. SOUTH/SOUTHEASTERLY LOW LEVEL FLOW WILL TRANSPORT MID 60S TO NEAR 70 DEW POINTS NORTHWARD ACROSS THE WARM SECTOR...WITH MODERATE TO STRONG INSTABILITY IN PLACE BY AFTERNOON. STEEP MIDLEVEL LAPSE RATES AND STRONG...VERTICALLY VEERING SHEAR PROFILES WILL FAVOR SUPERCELLS CAPABLE OF ALL SEVERE HAZARDS INCLUDING VERY LARGE HAIL AND TORNADOES. THESE THREATS ARE EXPECTED TO PERSIST TUESDAY EVENING ACROSS THE CENTRAL AND SOUTHERN PLAINS AS STRONGER FORCING/HEIGHT FALLS SPREAD ACROSS THESE AREAS.
...DAY 5/WEDNESDAY... THE SEVERE THREAT IS EXPECTED TO SHIFT EASTWARD ON DAY 6/WED ACROSS PARTS OF THE MIDDLE MS VALLEY TO NORTHEAST TX AHEAD OF THE EASTWARD-ADVANCING SURFACE LOW AND COLD FRONT. CONVECTION WILL LIKELY BE ONGOING WEDNESDAY MORNING ACROSS EASTERN PARTS OF THE CENTRAL AND SOUTHERN PLAINS INTO THE MID-MS VALLEY. THE FORECAST CAPE/SHEAR PARAMETER SPACE ACROSS THE WARM SECTOR SUGGESTS A 15% SEVERE-WEATHER THREAT AREA REMAINS WARRANTED FROM THE MID MS VALLEY TO THE NORTHEAST TX REGION FOR WEDNESDAY AFTERNOON AND EVENING...WITH ALL SEVERE HAZARDS POSSIBLE.
...DAY 6/THURSDAY - DAY 7/FRIDAY... WHILE THERE IS SOME MODEL VARIABILITY IN THE TRACK OF THE CENTRAL U.S. TROUGH AND SURFACE FEATURES DURING DAYS 4 AND 5...THE MODEL SPREAD INCREASES LATE THIS WEEK. ALTHOUGH STRONG TO SEVERE STORMS COULD OCCUR ON DAY 6/THURSDAY ACROSS THE MIDWEST/OH VALLEY...MODEL SYNOPTIC VARIABILITY RESULTS IN DIFFERING LOW-LEVEL MASS RESPONSES AND DEGREE OF DESTABILIZATION. THEREFORE...NO SEVERE PROBABILITY AREA WILL BE DELINEATED FOR DAY 6 IN THE MIDWEST/OH VALLEY. MEANWHILE...MODELS ARE IN GENERAL AGREEMENT FARTHER WEST SHOWING AN MID- TO UPPER-LEVEL TROUGH DEEPENING ACROSS THE GREAT BASIN INTO THE NORTHWEST MEXICO ON DAY 6/THU AND SHIFTING EAST INTO THE CENTRAL/ SOUTHERN ROCKIES AND NORTHERN MEXICO ON DAY 7/FRI. THIS UPPER PATTERN WILL RESULT IN SOUTHWEST FLOW EXTENDING ACROSS THE DRY LINE IN WEST TX ON THURSDAY AND FRIDAY...AND POSSIBLY INTO WESTERN KS ON FRIDAY AS WELL. THIS SCENARIO WOULD SUPPORT STRONG TO SEVERE STORM DEVELOPMENT ALONG THE DRY LINE...BUT UNCERTAINTY IN THE STRENGTH OF LOW-LEVEL CONVERGENCE AND TIMING OF ANY MIDLEVEL IMPULSES PRECLUDES THE INTRODUCTION OF 15% SEVERE PROBABILITIES FOR THU/FRI.
Read more from ScientificAmerican.com HERE:
(Image Credit: Presidencia de la República Mexicana/Flickr, CC BY 2.0 via ScientificAmerican.com)
The Key Players in Climate Change
Diplomats from at least 167 countries are gathering in New York to sign the climate accord reached in December in Paris. Whether they make good on their pledges to slow dangerous greenhouse gas emissions will depend in large part on the actions in the years ahead by the world’s largest polluters. A status report on the key players follows.
Read more from NYTimes.com HERE:
(Image Courtesy: Spencer Platt/Getty Images via NYTIMES.com)
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