Aikyam-Lab/Synoptic-Bench huggingface dataset:
219 AM EDT WED JUN 3 2015 HIGH PRESSURE WILL BRING CLEARING SKIES TODAY, BEFORE ANOTHER FRONT MOVES ACROSS THE REGION ON THURSDAY WITH A CHANCE FOR A SHOWER OR A THUNDERSTORM. AS THE UL TROF LIFTS OUT OF NY, SKIES WILL RAPIDLY CLEAR TONIGHT. UPPER LEVEL LOW ACROSS THE CAROLINAS WILL BE PUSHING MOISTURE INTO THE SOUTHERN PORTIONS OF THE REGION WITH CLOUDS MOVING IN FROM THE SOUTH OVERNIGHT INTO DAYBREAK.
145 AM EDT WED JUN 3 2015 HIGH PRESSURE WILL BRING CLEARING SKIES TODAY, BEFORE ANOTHER FRONT MOVES ACROSS THE REGION ON THURSDAY WITH A CHANCE FOR A SHOWER OR A THUNDERSTORM. QUIET WEATHER IS EXPECTED WEDNESDAY INTO WEDNESDAY EVENING AS HIGH PRESSURE BUILDS ACROSS QUEBEC AND NORTHERN NEW ENGLAND PUSHING CLOUDS AND RAIN WELL TO OUR SOUTH. AS THE UL TROF LIFTS OUT OF NY, SKIES WILL RAPIDLY CLEAR TONIGHT. UPPER LEVEL LOW ACROSS THE CAROLINAS WILL BE PUSHING MOISTURE INTO THE SOUTHERN PORTIONS OF THE REGION WITH CLOUDS MOVING IN FROM THE SOUTH OVERNIGHT INTO DAYBREAK.
AN UPPER LEVEL TROUGH WILL REMAIN OVER THE REGION TODAY BEFORE UNDERGOING A SPLIT OVERNIGHT AND THURSDAY. THIS SPLIT WILL DRIVE THE SOUTHERN PORTION OF THE TROUGH INTO CALIFORNIA WHERE IT WILL FORM A CLOSED LOW. FOR TODAY THE TROUGH WILL PROVIDE SOME MARGINAL ATMOSPHERIC INSTABILITY WHICH WILL BE TRIGGERED AS THE TEMPERATURES RISE THROUGH THE DAY. WITH THE TROUGH SPLITTING THURSDAY THERE WILL BE EVEN LESS INSTABILITY SO JUST LOOKING AT A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AGAIN MAINLY OVER THE EASTERN MOUNTAINS.
250 AM MDT WED JUN 3 2015 A PROMINENT TROUGH WILL AMPLIFY ALONG THE CALIFORNIA COAST TODAY AND EVENTUALLY FORMS A CLOSED CIRCULATION OVER SAN FRANCISCO AND MONTEREY AREA. LOW PRESSURE DEEPENING ALONG THE WEST COAST AND BOTTOMING OUT NEAR SOUTHERN CALIFORNIA WILL BECOME A BIG PLAYER IN OUR WEATHER FOR THIS UPCOMING WEEKEND. THIS LOW IS EXPECTED TO TAP TROPICAL MOISTURE FROM NOW TROPICAL STORM ANDRES AND HURRICANE BLANCA IN THE EASTERN PACIFIC.
THUNDERSTORM CHANCES EXPAND OVER THE SIERRA AND WESTERN NEVADA THURSDAY AS LOW PRESSURE DROPS INTO CALIFORNIA. THIS IS ASSOCIATED WITH A SOUTH-TO-NORTH JET EMERGING ALONG THE WEST SIDE OF AN UPPER LOW LOCATED OVER CENTRAL CA. WITH THE UPPER LOW NEARBY, STEERING FLOW FOR THUNDERSTORMS WILL BE VARIABLE AND WEAK.
AN UPPER TROUGH WILL REMAIN OVER THE REGION TODAY WITH LOW LEVEL ONSHORE FLOW. AN UPPER RIDGE WILL BUILD OVER THE PACIFIC NORTHWEST THURSDAY THROUGH THE WEEKEND FOR SUNNY AND WARMER WEATHER.
SUPPORTING THE CONCEPT OF MID LEVEL RIDGING BUILDING OVER THE AREA.
A WEAK UPPER LOW OVER EASTERN TN WILL DRIFT SOUTHWARD.
351 AM EDT WED JUN 3 2015 THE UPPER LEVEL LOW WILL CONTINUE TO SHIFT SLOWLY SOUTHEAST ACROSS THE APPALACHIANS TODAY. PERHAPS JUST A FEW DEGREES WARMER. THE LOW WILL HAVE SHIFTED SLIGHTLY FARTHER AWAY FROM THE REGION AS IT TRAVERSES THE CAROLINAS. THE STUBBORN UPPER LEVEL LOW WHICH HAS BEEN CONTROLLING OUR WEATHER WILL BE DRIFTING SOUTHEAST AT THE START OF THIS FORECAST PERIOD.
STRONG HIGH PRESSURE ALOFT WILL CONTINUE THE ABOVE AVERAGE TEMPERATURES THROUGH AT LEAST MID WEEK. LATEST GFS AND ECMWF MODELS WERE IN FAIRLY DECENT AGREEMENT WITH PULLING MID LEVEL MOISTURE INTO THE DESERT SOUTHWEST AS A LOW PRESSURE TROUGH DEEPENS ALONG THE WEST COAST.
425 AM CDT WED JUN 3 2015 THE CURRENT WEATHER PATTERN CONTINUES TO BE DOMINATED BY AN AMPLIFYING UPPER-LEVEL RIDGE EXTENDING FROM NORTHERN MEXICO INTO THE NORTHERN HIGH PLAINS. WITH DEEPENING UPPER LOWS OVER THE WEST AND EAST COASTS. DRY AND WARM SOUTHERLY LOW-LEVEL WINDS AND THE THERMAL RIDGE WILL PUSH AFTERNOON HIGH TEMPS INTO THE UPPER 80S/LOW 90S INTO THE WEEKEND FOR THE PANHANDLES. AS MODELS CURRENTLY SUGGEST A WEAKENING OF THE RIDGE IN ADVANCE OF HURRICANE BLANCA.
133 AM EDT WED JUN 3 2015 DRY AND INCREASINGLY WARMER WEATHER WILL BE IN STORE FOR THE REGION AS HIGH PRESSURE SLOWLY DRIFTS EAST. TRANQUIL WEATHER WILL PERSIST THROUGH TOMORROW AS LOW LEVEL RIDGE REMAINS LOCKED IN PLACE BETWEEN CUTOFF LOW TO OUR SOUTHEAST AND MAIN BELT OF WESTERLIES ACROSS CANADA. OBVIOUSLY NOT AS COLD AS LAST NIGHT BUT DID LEAN ON THE COOLER SIDE OF LATEST GUIDANCE AND CUT FORECAST TEMPS BY A FEW DEGREES.
356 AM EDT WED JUN 3 2015 HIGH PRESSURE WILL BUILD IN BRIEFLY FROM THE NORTH TODAY BRINGING DRIER CONDITIONS.
LARGE UPPER LEVEL LOW REMAINS OVER WESTERN CANADA. BRINGING JUST THE RIGHT STEERING FLOW TO KEEP THUNDERSTORMS GOING WITH UNSTABLE AIR THAT HAS JUST ENOUGH MOISTURE TO GENERATE THE THUNDERSTORMS OVER THE HIGH TERRAIN. WILL HAVE TO MONITOR THOUGH TO MAKE SURE THE HIGHER P. THE LOW THAT ENTERS SOUTHERN CALIFORNIA BEGINS TO LIFT NORTH-NORTHEASTWARD AND BRINGS MUCH BETTER UPPER LEVEL SUPPORT/INSTABILITY AND LARGE AMOUNTS OF MOISTURE FOR WHAT SHOULD BE A DAY FOR STRONG THUNDERSTORMS ON SAT AFTERNOON/EVENING. THE LOW IS EXPECTED TO STALL OVER NORTHERN UTAH. THE RIDGE TAKES OVER AND CONDITIONS DRY OUT CONSIDERABLY. AN UPPER LEVEL LOW PRESSURE WILL MOVE ON SHORE IN CALIFORNIA TODAY AND DOMINATE SOUTHEAST IDAHO WEATHER FOR SEVERAL DAYS. EXPECT DAILY SHOWERS AND THUNDERSTORMS TODAY THROUGH THE WEEKEND AS MOIST SOUTHERLY FLOW ALOFT WILL PERPETUATE AHEAD OF THE UPPER LOW.
CHATTANOOGA AIRPORT, TN 71 48 73 52 / 0 10 30 50 KNOXVILLE MCGHEE TYSON AIRPORT, TN 67 46 70 46 / 0 10 40 40 OAK RIDGE, TN 67 45 69 47 / 0 10 50 40 TRI CITIES AIRPORT, TN 64 40 68 45 / 10 20 50 30.
WV imagery shows zonal flow over West Texas and Southeast New Mexico this morning, w/an upper trough swinging thru the Great Lakes Region, and another off the coast of SoCal/Baja, south of a ridge extending up into the PacNW. An incoming trough to the PacNW over the next few days will push the ridge east and deepen the Baja trough, transitioning zonal flow aloft to SW over the next 24 hours. Wednesday, flow aloft becomes even more SW as the upper trough makes landfall, w/temps remaining abv-normal and even increasing a degree or two.
656 AM CDT TUE APR 21 2015 UPPER LOW WAS PARKED NEAR THE ARROWHEAD OF MN EARLY THIS AM WITH CWA RESIDING IN COOL NORTHWEST FLOW. CLOSED LOW WILL MEANDER SLOWLY EASTWARD THROUGH THE GREAT LAKES NEXT 24 HOURS WITH CWA REMAINING IN COOL NORTHWEST FLOW. COULD ALSO SEE A FEW PM SHOWERS NEAR/NORTH OF HWY 20 CORRIDOR WITH SPOKE OF ENERGY SHEARING ON BACKSIDE OF UPPER LOW.
1036 AM EDT TUE APR 21 2015 HIGH PRESSURE BUILDS OVER THE REGION THROUGH WEDNESDAY.
THE UPPER LEVEL RIDGE WILL SHIFT EAST INTO IDAHO IN RESPONSE TO THE APPROACHING UPSTREAM TROUGH. AT THE SURFACE A COLD FRONT WILL MOVE ASHORE THIS MORNING.
WITH LOW-LEVEL RIDGE SHIFTING SOUTHEASTWARD ACROSS THE CENTRAL GULF COAST EXPECTED TO RESULT IN A LIGHT SOUTHWEST RETURN FLOW BY LATE AFTERNOON. PRECIPITATION THIS EVENING AND OVERNIGHT SHOULD REMAIN CONFINED TO THE VICINITY OF A REINFORCING COLD FRONT WELL TO THE NORTH/WEST OF THE LOCAL FORECAST AREA. THE COLD FRONT WHICH HELPED DRIVE MUCH OF THE STRONG CONVECTIVE ACTIVITY EARLY MON. AS HIGH PRESSURE MAKES ITS WAY EWD ACROSS THE GULF REGION. BEFORE WARMER CONDITIONS/MOISTURE GRADUALLY RETURN TO THE AREA WED.
LOW LEVEL MOISTURE WILL SURGE NORTH ALONG/SOUTH OF WARM FRONT INTO SOUTHERN OKLAHOMA. SOME TIMING UNCERTAINTIES STILL REMAIN INCLUDING PLACEMENT OF WARM FRONT AND ANY LINGERING BOUNDARIES FROM THE EARLIER MORNING STORMS.
DRY AND COOLER TODAY WITH CLEARING SKIES. SURFACE COLD FRONT WAS PUSHING SOUTHWARD FROM SGJ TO JUST SOUTH OF GNV THIS HOUR TRAILED BY COOL AND DRY AIR ADVECTION. SURFACE DEW PTS WERE IN THE LOWER 50S NEAR THE ALTAMAHA RIVER BASIN WITH NNW WINDS NEAR 10 MPH. HIGH TEMPS WERE ON TRACK TO RISE INTO THE MID/UPPER 70S OVER SE GA TO THE LOWER 80S ACROSS NE FL WITH A MUCH DRIER AIRMASS IN PLACE AS AFTERNOON RELATIVE HUMIDITY FALLS INTO THE 30-40% RANGE INLAND.
as weak trough drops south along the coast. Some of the cloudiness is remnants from yesterday afternoon and evening's convection, while the clouds moving up from central California are associated with the deformation zone to the north of the weak closed mid/upper level low moving toward SoCal.
Deep upper low over the Great Lakes was making slow eastward progress early this morning with likely a few small scale waves rotating around it through the Northern and Central Plains. At least minor amounts of EPV along the moist layer allowing some showers to form aloft, with weak returns on radar showing some very light precip reaching to the lower troposphere. Cold front via a stronger wave rotating around the low arrives this evening and makes quick south progress through the state tonight.
MAIN STORY TODAY APPEARS TO BE NERLY/ERLY WINDS RUNNING AROUND 10 KNOTS AS HIGH PRESSURE BUILDS PAST THE REGION. THE MORE ONSHORE FLOW EXPECTED LATER ON WILL ALLOW THE LOW-LEVELS TO MOISTEN. /ISSUED 407 AM CDT TUE APR 21 2015/ A CONTINENTAL TYPE AIRMASS WILL CONTINUE ACROSS THE FORECAST AREA TODAY AS HIGH PRESSURE AT THE SURFACE MOVES ACROSS THE LOWER MISSISSIPPI VALLEY.
THE REGION WILL GET ONE MORE DAY OF ABOVE NORMAL TEMPERATURES BEFORE A BROAD AREA OF LOW PRESSURE BRINGS CHANGES STARTING ON WEDNESDAY.
94 INCHES OF PRECIPITABLE WATER WITH A SLIGHTLY VEERING FLOW THROUGH THE LOWER LEVELS. UNDER LIGHT SOUTHWESTERLY WINDS WE WOULD ANTICIPATE THE DEVELOPMENT OF A REVERSE CLOUD LINE ALONG THE LOWER AND MIDDLE KEYS.
TEMPERATURES REMAIN COOLER THAN NORMAL WITH BREEZY WINDS TODAY. ESPECIALLY THIS AFTERNOON AS A MID-LEVEL TROUGH AXIS SWINGS THROUGH. PRODUCING ONE TO THREE INCHES ALONG THE HIGHER TERRAIN OF THE SOUTH SHORE OF LAKE SUPERIOR. AS HIGH PRESSURE BUILDS IN TO THE WEST EXPECT SOME CLEARING SKIES IN THE WESTERN PARTS OF THE CWA BY WEDNESDAY AFTERNOON. WENT ON THE COOLER SIDE OF MOST GUIDANCE DUE TO THE CLOUD COVER ACROSS THE REGION AND GENERAL COLD AIR ADVECTION REGIME IN PLACE. ONE TO THREE INCHES OF SNOWFALL WILL BE POSSIBLE ACROSS THE HIGHER TERRAIN. HIGHS EDGING WARMER IN THE MID 30S TO LOW 40S.
710 AM CDT TUE APR 21 2015 AS VORT MAX DIVES FROM SOUTHEASTERN SASK THRU CNTRL ND INTO CNTRL SD THIS EARLY MORNING A LOBE OF MOISTURE IS WRAPPING BACK AROUND THE UPPER LOW NEAR DULUTH THRU THE RRV AND NORTHERN MN PRODUCING -SN. AS THIS MOISTURE AREA MOVES SOUTH AROUND THE UPPER LOW. EXPECT A DECREASE IN LIGHT PRECIP MIDDAY AND INTO THE AFTN AND AS THE UPPER LOW STARTS MOVING EAST. UPPER LEVEL LOW NEAR DULUTH WILL BEGIN TO MOVE EAST TODAY. WITH THE CLOUDS HAVING BEEN SHIFTING A BIT SOUTHWEST WITH TIME DURING THE NIGHT AS AN IMPULSE DROPS BACK SOUTH AROUND THE UPPER LOW. AS THE UPPER LOW MOVES EAST LOOK FOR THE CLOUDS TO GRADUALLY CLEAR FROM WEST TO EAST THIS AFTN INTO ERN ND AND THEN THIS EVENING INTO NW MN.
A GENERALLY ZONAL FLOW TO A WEAK RIDGE ALOFT IS PROGD THROUGH THE SHORT TERM. MODELS SHOW DRYING IN THE MID/UPPER LEVELS AND INCREASING MOISTURE IN THE LOW LEVELS THROUGH THE AFTERNOON. SOME WEAK TO MOD CAPE IS ALSO PROGD FOR THIS AFTERNOON WITH THE HIGHER VALUES ACROSS THE S CWA. THE CHC POPS SHIFT E WED AS MODELS PROG CAPES TO INCREASE TO BTWN 3K-4K J/KG WITH THE HIGHER VALUES ACROSS THE CENTRAL AND E CWA.
CREST OF THE UPPER RIDGE RESIDES OVER SE OREGON/SW IDAHO TODAY. LIMITED MOISTURE AND INSTABILITY AHEAD OF A COLD FRONT IN CENTRAL OREGON WILL LEAD TO ISOLATED SHOWERS AND THUNDERSTORMS IN WESTERN HARNEY COUNTY LATE THIS AFTERNOON. SKIES WILL REMAIN MOSTLY CLEAR WITH SOME CUMULUS BUILDUPS OVER THE HIGHER TERRAIN. ON WEDNESDAY EXPECT ISOLATED AFTERNOON AND EVENING THUNDERSTORMS OVER THE HIGHER TERRAIN OF CENTRAL AND SOUTHWEST IDAHO AND EASTERN OREGON. BECOMING NORTHWEST AND INCREASING TO 15-20G30 KTS ON WEDNESDAY FOLLOWING A COLD FRONT PASSAGE TONIGHT.
the second short wave is fcst to pass north of the area tonight pushing a cold front thru the region.
AN UPPER LEVEL HIGH PRESSURE RIDGE WILL TO APPROACH THE ROCKIES TODAY AND LIGHT, NORTHWEST FLOW ALOFT WILL CONTINUE OVER THE ZONES. HIGH PRESSURE RIDGING WILL CONTINUE TO BUILD INTO MONTANA, WITH LIGHT SURFACE WINDS AND SCT-BKN MID AND HIGH LEVEL CLOUDS EXPECTED TODAY. SLIGHTLY UNSTABLE CONDITIONS DEVELOP THIS AFTN, LEADING TO ISOLATED SHOWERS AND A FEW SHORT-LIVED THUNDERSTORMS OVER THE HIGHER TERRAIN NEAR KBZN/KHLN.
707 AM EDT TUE APR 21 2015 HIGH PRESSURE WILL BUILD IN TODAY THROUGH WEDNESDAY.
WESTERLY WINDS WILL REMAIN GUSTY THIS AFTERNOON AS A TIGHT SFC PRESSURE GRADIENT IS IN PLACE BEHIND A LARGE SCALE LOW PRESSURE SYSTEM. A BRIEF WINTRY MIX IS POSSIBLE THIS AFTERNOON WITH THESE COOLER TEMPERATURES. EXPECT THE LOW END VFR CIGS TO CONTINUE. THE LARGE UPPER LOW WILL SLOWLY MOVE ACROSS THE NRN GREAT LAKES AND ONTARIO CANADA THROUGH THE PERIOD. THE PRESSURE GRADIENT AND STEEP LOW LEVEL LAPSE WILL MAINTAIN BRISK WLY WINDS THAT WILL TURN NWLY TNT WITH THE PASSAGE OF ANOTHER COLD FRONT.
1237 PM EDT TUE APR 21 2015 LOW PRESSURE WILL DRIVE AN OCCLUDED FRONT ACROSS THE REGION TODAY PRECEDED BY LOCALLY HEAVY RAIN AND SCATTERED THUNDERSTORMS.
THE LAST COUPLE OF AFTERNOONS WINDS HAVE NOT BEEN QUITE AS STRONG WITH THE LOW LEVEL CLOUDS HANGING TOUGH. UPPER LEVEL LOW NEAR DULUTH WILL BEGIN TO MOVE EAST TODAY. WITH THE CLOUDS HAVING BEEN SHIFTING A BIT SOUTHWEST WITH TIME DURING THE NIGHT AS AN IMPULSE DROPS BACK SOUTH AROUND THE UPPER LOW. AS THE UPPER LOW MOVES EAST LOOK FOR THE CLOUDS TO GRADUALLY CLEAR FROM WEST TO EAST THIS AFTN INTO ERN ND AND THEN THIS EVENING INTO NW MN.
COOLER AND MUCH DRIER CONDITIONS NOTED BEHIND THE FRONT WITH MID 40S DEWPOINTS AND TEMPS IN THE MID 50S. SUPERB CONDITIONS FOR TODAY WITH HIGHS CLOSE TO AVERAGE BUT LIKELY FEELING SLIGHTLY COOLER DUE TO THE DRIER CONDITIONS AND ELEVATED WINDS THROUGH EARLY AFTERNOON.
SURFACE ANALYSIS PLACES A RIDGE OF HIGH PRESSURE OVER PORTIONS OF NORTHEAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY.
703 AM EDT TUE APR 21 2015 A TROUGH/SECONDARY COLD FRONT WILL MOVE ACROSS THE AREA LATE TODAY USHERING IN MUCH COOLER CONDITIONS.
AN UPPER LOW CURRENTLY OVER SOUTHERN CA WILL CONTINUE TO CARVE DEEPER OVER THE BAJA PENINSULA THROUGH WEDNESDAY.
1114 AM EDT TUE APR 21 2015 COOLER AIR TAKING OVER IN THE WAKE OF A COLD FRONT. WILL BE REINFORCED BY ANOTHER COLD FRONT WEDNESDAY.
537 AM MDT TUE APR 21 2015 NORTHWEST FLOW CONTINUES ACROSS THE CENTRAL PLAINS THROUGH TONIGHT AHEAD OF A RIDGE BUILDING INTO THE ROCKIES.
612 AM CDT TUE APR 21 2015 QUIETER AND COOLER WEATHER IS ARRIVING INTO THE AREA. UPPER-LEVEL RIDGE WAS NOTED ACROSS CA. WITH TROUGH JUST OFF THE PACIFIC NORTHWEST COAST. WITH WARM AIR ADVECTION IN THE CENTRAL PLAINS AND RIDGING ACROSS THE WESTERN US. TEMPERATURES TONIGHT SHOULD FALL TO NEAR OR BELOW FREEZING IN MOST LOCATIONS TONIGHT. MOST IMPACTS OF THIS FREEZE WOULD BE TO A FEW EARLY- GROWTH PERENNIALS AND EARLY PLANTINGS IN HOME GARDENS COMPLETED DURING THE WARMER TEMPERATURES LAST WEEK. BUT WEDNESDAY NIGHT TEMPERATURES SHOULD STAY SLIGHTLY WARMER THAN TONIGHT AS MID-LEVEL WARM/MOIST AIR ADVECTION COMMENCES.
AND A W COAST RIDGE THAT MAKES SLOW BUT STEADY PROGRESS INTO THE INTERMOUNTAIN W. THIS TROF WILL CONT AROUND THE BACKSIDE OF THE GREAT LAKES LOW AND HEAD INTO THE MIDWEST TONIGHT. THE NEXT SHOT OF COOL AIR WILL BE DELIVERED BY THIS TROF. THIS LOW WILL MOVE SSE AND ACROSS NEB TODAY ALONG WITH ITS TRAILING COOL FRONT. HIGHS WILL BE A LITTLE WARMER THAN NORMAL.
1155 AM CDT TUE APR 21 2015 QUIETER AND COOLER WEATHER IS ARRIVING INTO THE AREA. UPPER-LEVEL RIDGE WAS NOTED ACROSS CA. WITH TROUGH JUST OFF THE PACIFIC NORTHWEST COAST. WITH WARM AIR ADVECTION IN THE CENTRAL PLAINS AND RIDGING ACROSS THE WESTERN US. TEMPERATURES TONIGHT SHOULD FALL TO NEAR OR BELOW FREEZING IN MOST LOCATIONS TONIGHT. MOST IMPACTS OF THIS FREEZE WOULD BE TO A FEW EARLY- GROWTH PERENNIALS AND EARLY PLANTINGS IN HOME GARDENS COMPLETED DURING THE WARMER TEMPERATURES LAST WEEK. BUT WEDNESDAY NIGHT TEMPERATURES SHOULD STAY SLIGHTLY WARMER THAN TONIGHT AS MID-LEVEL WARM/MOIST AIR ADVECTION COMMENCES.
1023 AM EDT TUE APR 21 2015 HIGH PRESSURE WILL BUILD IN TODAY THROUGH WEDNESDAY.
925 AM EDT TUE APR 21 2015 A TROUGH/SECONDARY COLD FRONT WILL MOVE ACROSS THE AREA LATE TODAY USHERING IN MUCH COOLER CONDITIONS.
WINDY CONDITIONS WILL PREVAIL TODAY AND TOMORROW AS CENTRAL INDIANA IS IMPACTED BY A BROAD LOW PRESSURE SYSTEM OVER THE GREAT LAKES REGION.
TODAY WILL BE A BEAUTIFUL SPRING DAY WITH HIGHS TOPPING OUT IN THE LOWER 70S WITH ABUNDANT SUNSHINE. SURFACE ANALYSIS PLACES A RIDGE OF HIGH PRESSURE OVER PORTIONS OF NORTHEAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY.
HIGH PRESSURE WILL BUILD OVER NC FROM THE SOUTHWEST TODAY AND TONIGHT.
1030 AM CDT TUE APR 21 2015 UPDATED GRID/PUBLIC FORECAST TO BETTER REFLECT TEMP TRENDS (WARMER) AND ALTER PRECIP WORDING TO COVERAGE TERMINOLOGY. LOW FREEZING LEVEL HEIGHTS. (CN) A PASSING WAVE IN THE MEAN BROAD CYCLONE'S TROF WILL ALLOW FRONTOGENETIC FORCING/ASSOCIATED POPS TO REDEVELOP AND SPREAD ALONG THE LOWER OHIO RIVER VALLEY LATER TODAY-TONIGHT. SO POPS WILL END WEST TO EAST AS HIGH PRESSURE BUILDS ACROSS THE MIDDLE AND UPPER MISSISSIPPI VALLEY AT THE SURFACE. SOME DIRTY OVERRUN OF THE HIGH FROM THE SOUTH MAY WARRANT A SMALL CHANCE POP REAPPEARANCE THERE WED NIGHT. OTHERWISE WE'LL CLOSE OUT THE SHORT TERM MAINLY DRY/UNDER THE INFLUENCE OF THE HIGH.
WITH A SHARP FULL-LATITUDE RIDGE JUST INLAND FM THE WEST COAST. AND A DEEP TROF OVER THE GREAT LAKES RGN. THE PATTERN IS EXPECTED TO EVOLVE INTO A BLOCKING REGIME AS STG POSITIVE UPR HEIGHT ANOMALY BUILDS WWD FM THE NORTH ATLANTIC. SETTLING IN N OF NEGATIVE ANOMALY WITH THE GREAT LAKES UPR TROF.
LATER THIS AFTERNOON AND EVENING A SLOW MOVING COLD FRONT WILL APPROACH THE STATE FROM THE NORTH AND BRING CHANCES FOR PRECIPITATION ACROSS NORTHERN ARKANSAS.
SURFACE RIDGING SHOULD KEEP MOIST ADVECTION OFF THE GULF OF MEXICO OUT OF THE PICTURE FOR FLIGHT OPERATIONS THROUGH THE PERIOD WHICH SHOULD RESULT IN CEILINGS ABOVE FIVE THOUSAND FEET. THERE COULD BE SOME SCATTERED TO BROKEN AC AT TIMES AS ENERGY ROTATES AROUND A BROAD UPPER LEVEL TROUGH IN PLACE OVER MUCH OF THE NORTH CENTRAL THROUGH EASTERN U.
ONLY MINOR CHANGES NEEDED FOR THE HIGHS. THE MEAN TROUGH AXIS HAS SHIFTED EAST OF CENTRAL ALABAMA WITH BENIGN WEATHER THROUGH MUCH OF WEDNESDAY.
HAVE THEREFORE MAINTAINED OUR FORECAST HIGHS IN THE LOW TO MID 70S. LOW LEVEL MOISTURE WILL SURGE NORTH ALONG/SOUTH OF WARM FRONT INTO SOUTHERN OKLAHOMA. SOME TIMING UNCERTAINTIES STILL REMAIN INCLUDING PLACEMENT OF WARM FRONT AND ANY LINGERING BOUNDARIES FROM THE EARLIER MORNING STORMS.
OUR FORECAST AREA REMAINS UNDER A WEAKLY CYCLONIC NORTHWEST FLOW AS A RIDGE TO OUR WEST ATTEMPTS TO PUSH EAST. THE OTHER WEAK FEATURE WE HAVE IS A BACK DOOR COLD FRONT TRYING TO PUSH INTO OUR EASTERN ZONES THIS MORNING. THE RIDGE AXIS MOVES OVER MONTANA WEDNESDAY WITH SOME MOISTURE SNEAKING UP UNDER IT AND DECENT INSTABILITY TO INCLUDE SOME LOW MOUNTAINS POPS. THERMAL RIDGE WILL MAX OUT OVER US WEDNESDAY FOR HIGHS AROUND 70 IN MANY LOCATIONS.
A COLD FRONT WILL MOVE INLAND THIS AFTERNOON AND EVENING BRINGING AN ABRUPT CHANGE IN THE WEATHER.
632 AM CDT TUE APR 21 2015 AN ARCTIC COLD FRONT ACROSS NORTH DAKOTA WILL BACK INTO THE FCST AREA THIS AFTN PRODUCING SOME CLOUDINESS. BY 12Z WEDNESDAY A SMALL AREA OF HIGH PRESSURE HAS SETTLED OVER NCNTL NEB WHICH SHOULD PRODUCE LOWS IN THE 20S. THE MODELS SUGGEST ANY CLOUD COVER WOULD LIE ACROSS THE PANHANDLE AND SOUTHWEST NEB WHICH WOULD HOLD UP LOWS IN THE LOWER 30S. THE RADAR RETURNS ACROSS NORTH DAKOTA MOVE EAST OF THE FCST AREA IN THE NAM MODEL WHILE THE HRRR SHOWS TOO MUCH DRY AIR IN THE LOWER LEVELS FOR ANYTHING MORE THAN SPRINKLES THIS AFTN AND TONIGHT. MEANWHILE AN UPPER LEVEL LOW LIFTS TOWARDS THE DESERT SW.
744 AM EDT TUE APR 21 2015 AN APPROACHING COLD FRONT WILL BRING MORE INSTABILITY TO THE ATMOSPHERE OVER SOUTH FLORIDA. THE COLD FRONT IS THEN EXPECTED TO PUSH INTO SOUTH FLORIDA LATER TODAY WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING AND PUSHING INTO THE AREA AHEAD OF THE FRONT BEGINNING LATE THIS MORNING. COVERAGE OF SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO SLOWLY DECREASE TOWARD THE END OF THE WEEK AND INTO THE WEEKEND AS STRONG UPPER RIDGING IS STILL EXPECTED TO BUILD INTO THE EASTERN GULF OF MEXICO.
WINDS WILL AGAIN BE A CONCERN OVER THE JAMES RIVER VALLEY REGION TODAY AS PRESSURE GRADIENT REMAINS TIGHT WHILE HIGH PRESSURE SETTLES IN OVER THE WEST KEEPING CONDITIONS MUCH CALMER. THIS WILL AGAIN BRING FIRE WEATHER CONCERNS TO THE JAMES RIVER VALLEY REGION GIVEN THE LOW HUMIDITY VALUES EXPECTED AGAIN TODAY. A NORTHWEST FLOW ALOFT WILL PERSIST THROUGH THE MIDDLE OF THE WEEK WITH A QUASI-BLOCKING PATTERN IN PLACE.
Winds will be mostly from the south or south-southeast, with the higher speeds and gusts at KABI. A weak upper low off the coast of southern California will move east into the southern part of that state late today and tonight. A weak disturbance out ahead of this low may approach the Big Bend region by early Wednesday morning. Temperatures will be warmer, with highs this afternoon expected to be in the upper 70s to lower 80s, and lows tonight in the lower to mid 60s. Weak upper level ridging will track east into the Southern Plains, but it will not be strong enough to suppress convection.
WITH LOW-LEVEL RIDGE SHIFTING SOUTHEASTWARD ACROSS THE CENTRAL GULF COAST EXPECTED TO RESULT IN A LIGHT SOUTHWEST RETURN FLOW BY LATE AFTERNOON. PRECIPITATION THIS EVENING AND OVERNIGHT SHOULD REMAIN CONFINED TO THE VICINITY OF A REINFORCING COLD FRONT WELL TO THE NORTH/WEST OF THE LOCAL FORECAST AREA.
UPPER LEVEL LOW NEAR DULUTH WILL BEGIN TO MOVE EAST TODAY. WITH THE CLOUDS HAVING BEEN SHIFTING A BIT SOUTHWEST WITH TIME DURING THE NIGHT AS AN IMPULSE DROPS BACK SOUTH AROUND THE UPPER LOW. AS THE UPPER LOW MOVES EAST LOOK FOR THE CLOUDS TO GRADUALLY CLEAR FROM WEST TO EAST THIS AFTN INTO ERN ND AND THEN THIS EVENING INTO NW MN.
909 AM EDT TUE APR 21 2015 LOW PRESSURE WILL DRIVE AN OCCLUDED FRONT ACROSS THE REGION TODAY PRECEDED BY LOCALLY HEAVY RAIN AND SCATTERED THUNDERSTORMS.
THE COLD FRONT WHICH HELPED DRIVE MUCH OF THE STRONG CONVECTIVE ACTIVITY EARLY MON. AS HIGH PRESSURE MAKES ITS WAY EWD ACROSS THE GULF REGION. BEFORE WARMER CONDITIONS/MOISTURE GRADUALLY RETURN TO THE AREA WED.
633 AM CDT TUE APR 21 2015 12Z TAF CYCLE AN UPPER RIDGE WILL SLOWLY BUILD IN FROM THE WEST TONIGHT AND WEDNESDAY WHILE A COLD FRONT MOVES THROUGH THE PANHANDLES TONIGHT AND EARLY WEDNESDAY. A SFC TROF OF LOW PRESSURE WILL ORIENT ITSELF ALONG THE NM AND TX STATE LINE THIS AFTERNOON. WHICH WILL LIKELY IMPINGE ON A SWD MOVG COLD FRONT. WITH MINOR DIFFERENCES ON COLD FRONTAL TIMING. SFC COLD FRONT WILL SETTLE TO A POSITION JUST SOUTH AND WEST OF THE FCST AREA ON WEDNESDAY.
706 AM EDT TUE APR 21 2015 UPPER AIR PATTERN CONSISTS OF A 500 MB LOW OVER THE UPPER GREAT LAKES EMBEDDED IN A TROUGH ACROSS THE GREAT LAKES REGION. LOOKS LIKE THERE COULD BE SOME INSTABILITY SHOWERS TODAY WITH THE UPPER LOW OVERHEAD AND ALSO A LAKE BREEZE CONTRIBUTION IN THE EASTERN CWA WHICH WILL ENHANCE THE SHOWERS AND THIS WAS ALREADY COVERED IN THE POPS. NORTHWEST LAKE EFFECT SNOW BELTS WILL HAVE THE HIGHEST POPS FOR THIS FORECAST PERIOD AND THERE WILL BE SOME ACCUMULATING SNOW ON THE GRASS THIS FORECAST PERIOD WITH 2 INCHES IN THE WEST FOR TODAY AND UP TO 3 INCHES TONIGHT.
A cold front will sweep through the region from late this evening through the early overnight hours, ushering in colder temperatures and very briefly gusty northwest winds. Have mentioned patchy frost in areas where the low temperature is expected to meet or drop below 35 degrees, but do not feel that the potential for frost is high enough to warrant an advisory at this time. High temps will be significantly cooler on the north side of the front, topping out only in the mid to upper 50s Wednesday afternoon.
A WARM FRONT WILL MOVE ACROSS DEEP SOUTH TEXAS LATER TODAY. THE COMBINATION OF INCREASING DEWPOINTS AND PRECIPITABLE WATERS ALONG WITH LIFT ASSOCIATED WITH A WARM FRONT WILL RESULT IN A CHANCE OF SHOWERS AND EMBEDDED THUNDERSTORMS FOR TODAY. TODAY WILL BE WARM WITH HIGH TEMPERATURES IN THE LOW TO MID 80S UNDER MOSTLY CLOUDY SKIES. HIGH TEMPERATURES WEDNESDAY WILL RANGE FROM THE LOW 80S ALONG THE BEACHES.
ALLOWING THE LONGWAVE TROF TO EXPAND AND REMAIN ANCHORED OVER ERN NOAM THRU TNGT. THIS SCENARIO COMBINED WITH DECRG CLOUDS AND CONTINUED CAA WILL ALLOW FOR TEMPERATURES SO DROP BELOW THE FREEZING MARK EARLY WED MRNG.