Aikyam-Lab/Synoptic-Bench huggingface dataset:
140 PM EDT MON JUL 13 2015 WV IMAGERY AND RAP ANALYSIS INDICATED A BORAD MID/UPPER LEVEL RIDGE CENTERED OVER THE SRN PLAINS AND A TROUGH OVER SRN MANITOBA. EXPECT THE MID LEVEL TROUGH INTO THE NRN LAKES TO GRADUALLY SINK OFF TO THE SE. WITH THE LOSS OF DAYTIME INSTABILITY AND ANY WEAK MID LEVEL FORCING WITH THE TROUGH. THERE MAY BE SOME SHOWERS LATE INTO THE NORTH AS THE COLD FRONT SLIDES INTO THE AREA. AND MAY BE MORE LIMITED THROUGH THE REST OF THE FCST PERIOD IF THE NEXT COUPLE OF SYSTEMS ARE UNABLE TO BREAK DOWN THE STUBBORN 500MB RIDGE ACROSS MUCH OF THE CENTRAL U. AND LARGE HIGH PRESSURE PUSHES IN FROM CENTRAL CANADA. THIS WILL BE WHILE THE 500MB LOW OVER N QUEBEC AND TROUGH EXTENDING ACROSS LOWER MI EXIT TOO.
VERY LITTLE DAY TO DAY CHANGE EXPECTED WITH UPPER LEVEL RIDGING ANCHORED OVER NORTH TEXAS SO LEANED TOWARD PERSISTENCE. /ISSUED 355 AM CDT MON JUL 13 2015/ TYPICAL SUMMER TIME PATTERN HAS SET UP OVER MUCH OF TEXAS WITH 00Z 500MB ANALYSIS SHOWING 596 DM RIDGE OVER W TX. RIDGE STRETCHES OVER MUCH OF THE S PLAINS TOWARDS THE MISS RIVER VALLEY AND NW GULF OF MEXICO. GFS/ECMWF SUGGEST THAT GOING INTO THE NEXT SUN/MON TIME FRAME THAT THE RIDGE MAY BEGIN TO RETROGRADE BACK OVER THE S ROCKIES ALLOWING FOR A WEAK NW FLOW PATTERN TO DEVELOP.
AN UPPER TROUGH AS WELL AS WEAK LOW LEVEL CONVERGENCE WERE ACTING ON A MOIST AIRMASS WITH SFC DEWPOINTS IN THE LOWER TO MIDDLE SIXTIES. HIGH PRESSURE WILL BUILD OVER LAKE SUPERIOR ON TUESDAY WITH OFF LAKE WINDS DEVELOPING. AREAS AROUND THE LAKE WILL ALSO BE MUCH COOLER.
HIGH PRESSURE REMAINS IN CONTROL. CONTINUED HOT AND DRY WEATHER FOR THE SHORT TERM PERIOD AS MID/UPPER LEVEL RIDGING REMAINS CENTERED OVER TEXAS.
A BROAD MID/UPPER LEVEL TROUGH REMAINS POSITIONED ALONG THE ENTIRE WEST COAST WHILE HIGH PRESSURE IS CENTERED OVER TEXAS AND NEW MEXICO. MILD CONDITIONS PERSIST THIS MORNING WITH TEMPERATURES GENERALLY IN THE LOW/MID 60S REGION-WIDE AS SEA SURFACE TEMPERATURES REMAIN IN THE LOW 60S. WEAK DISTURBANCES WILL CONTINUE TO PROPAGATE THROUGH THE TROUGH AND WILL BRING MID/HIGH LEVEL CLOUDS ACROSS THE REGION. TEMPERATURES ARE FORECAST TO BEGIN A SLIGHT WARMING TREND TODAY AND TUESDAY AS THE TROUGH WEAKENS AND BEGINS TO SLOWLY SHIFT NORTHWARD.
EXPECT SOME REDEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND EVENING AS THE UPPER TROUGH AND SFC COLD FRONT MOVE IN. AND MAY BE MORE LIMITED THROUGH THE REST OF THE FCST PERIOD IF THE NEXT COUPLE OF SYSTEMS ARE UNABLE TO BREAK DOWN THE STUBBORN 500MB RIDGE ACROSS MUCH OF THE CENTRAL U. AND LARGE HIGH PRESSURE PUSHES IN FROM CENTRAL CANADA. THIS WILL BE WHILE THE 500MB LOW OVER N QUEBEC AND TROUGH EXTENDING ACROSS LOWER MI EXIT TOO.
THIS AREA OF CONVECTION A RESULT OF A MINOR MID LEVEL TROUGH CROSSING THE REGION AIDED BY A ZONE OF LOW LEVEL WARM AIR ADVECTION.
245 PM CDT MON JUL 13 2015 WV imagery shows that the upper ridge has shifted slightly east over the last 24 hours, but remains centered over the Texas South Plains. W/a modest cap in place, and the theta-e ridge well west into New Mexico, vis sat imagery shows even cu having a hard time developing this afternoon. Instead, widespread triple-digit temps are expected across West Texas and Southeast New Mexico this afternoon, w/similar conditions Tuesday before thicknesses fall as the ridge shifts east to the ArklaTex Tuesday night in response to a trough deepening along the west coast. Forecast soundings, 850mb temp fields, and model performance over the past few days suggest staying toward the cooler end of guidance, but this will still yield temps well-abv normal.
THE TROUGH OVER THE REGION BRINGS CONDITIONS THAT HAVE THE POSSIBILITY OF INITIATING SHOWERS AND ISOLATED THUNDERSTORMS OVER THE HIGH TERRAIN OF NW CALIFORNIA LATE THIS AFTERNOON AND EVENING. ACTIVITY WILL BEGIN TO SUBSIDE TONIGHT WITH ONLY A SLIGHT CHANCE OF SHOWERS OVER THE TRINITY HORN TUESDAY AFTERNOON AS HIGH PRESSURE BEGINS TO BUILD BACK OVER THE EASTERN PACIFIC. CONVECTIVE ACTIVITY IS EXPECTED ACROSS THE INTERIOR LATE THIS AFTERNOON AND EVENING AS THE TROUGH PERSISTS ALOFT.
OVERALL WE THINK TUE-WED WILL BE A PERIOD OF FAIRLY QUIET AND SLIGHTLY COOLER WEATHER FOR THE LOCAL AREA.
BUT SHOWERS AND STORMS ARE STARTING TO REDEVELOP FURTHER UPSTREAM OVER NORTH DAKOTA AND S CENTRAL CANADA WITHIN AN AREA OF STRONGER LOW LEVEL CONVERGENCE/UPPER LEVEL DIVERGENCE UNDER THE 500 MB TROUGH AXIS. UPPER LEVEL TROUGH AND SURFACE RESPONSE WILL SWING SE INTO MICHIGAN TONIGHT.
MID LEVEL RIDGE BUILDS INTO THE FA TUESDAY AND HOLDS INTO MID WEEK. WATER VAPOR SHOWING WEAK UPSTREAM IMPULSES WHICH MAY RIDE THROUGH RIDGE.
A strengthening upper level high pressure area centered over the forecast area will continue to bring hot and dry weather. Lows tonight will be in the lower to mid 70s, with highs Tuesday in the upper 90s and possibly a few triple digit readings.
TONIGHT AND TUESDAY AN UPPER LOW MOVING THROUGH THE GREAT LAKES REGION WILL PROVIDE ANOTHER OPPORTUNITY FOR SHOWERS AND STORMS TO DEVELOP THIS AFTERNOON BEFORE COMING TO AN END THIS EVENING. BEFORE RIDGING BUILDS IN AND BRINGS PRECIP CHANCES TO AN END AS AN ENTRY INTO A RELATIVELY QUIET MID-WEEK.
1210 PM CDT MON JUL 13 2015 FOR 18Z TAFS /ISSUED 1110 AM CDT MON JUL 13 2015/ THE TENNESSEE VALLEY CONTINUE TO BE CONTROLLED MOSTLY BY RIDGING EXTENDING NORTHEAST FROM A STRONG AREA OF HIGH PRESSURE OVER THE CENTRAL GULF COAST STATES. THE MAIN PLAYER IN OUR FORECAST TODAY WILL CONTINUE TO BE THE STRONG RIDGING IN PLACE AND A WEAK BOUNDARY WHICH STRETCHES FROM NEAR NASHVILLE TO EXTREME SW TENNESSEE.
THIS MOISTURE WILL THEN MOVE NORTHEAST AND EAST OVER OUR AREA ON THE NORTHERN PERIPHERY OF THE SOUTHERN PLAINS UPPER LEVEL HIGH PRESSURE SYSTEM. THE PERSISTENT UPPER RIDGE OVER THE SOUTHERN U.
THE MAIN UPPER TROUGH AND ASSOCIATED SURFACE SYSTEM WILL PASS BY TO OUR NE LATE TUESDAY AND TUESDAY EVENING. THE ATMOSPHERE IS EXPECTED TO BE PRIMED FOR CONVECTIVE DEVELOPMENT AGAIN IN THE AFTERNOON AND EVENING AHEAD OF THE COLD FRONT ASSOCIATED WITH THE SYSTEM.
CU FIELD IS ALSO DEVELOPING A LITTLE EARLIER TODAY ACROSS THE NORTH ALONG MOUNTAIN RIDGES. 19 AN UPPER HIGH CENTERED TO THE WEST OF ALABAMA WILL PRODUCE A NORTHWEST FLOW PATTERN.
621 AM EDT TUE OCT 20 2015 HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE END OF THE WEEK. BELOW NORMAL TEMPERATURES WILL MODERATE FOR THE LATTER HALF OF THE WORKWEEK AS AN UPPER-LEVEL RIDGE BUILDS OVER THE AREA.
The chance for will improve during the overnight hours as moisture and improving upper level lift develops ahead of an upper level trough that is forecast to cross western Kansas tonight.
A STATIONARY FRONT EXTENDED EAST FROM THIS LOW FROM FARIBAULT MINNESOTA TO GREEN BAY WISCONSIN. TEMPERATURES RANGED FROM THE UPPER 50S TO MID 60S WHICH IS WARMER THAN OUR NORMAL HIGH TEMPERATURES FOR MID OCTOBER. 20Z MODELS ARE IN GENERAL AGREEMENT THAT A SHORT WAVE TROUGH. MOST PLACES HAVE THEIR HIGH TEMPERATURES IN THE LOWER TO MID 80S WHICH OCCURRED IN 1953. 00Z MODELS ARE IN GOOD AGREEMENT THAT A COLD FRONT WILL MOVE THROUGH THE AREA.
HIGHS TODAY AND WEDNESDAY WILL BE IN THE LOWER TO MID 70S. TEMPERATURES WILL BE EVEN WARMER TODAY THAN YESTERDAY GIVEN FAVORABLE INSOLATION. WITH GREATEST LOWERING THU NIGHT AS CORE OF LOW LEVEL THERMAL TROF ANCHORED FROM MI THUMB INTO NERN CWA AND 1033 MB ANTICYCLONE SITUATED NORTH OF LK SUPR. BLENDED POPS A BIT EGGREGIOUS IN BRINGING POP/WX FRI NIGHT AMID DEVOLUTION OF SPLIT FLOW REGIME/STRONG LONGWAVE RIDGING INTO GRTLKS AS SWRN SYSTEM LIFTS THROUGH PLAINS IN NEG TILTED FASHION.
AND GENERALLY IN THE LOW TO MID 50S OVER CENTRAL LOUISIANA INTO INTERIOR SOUTHEAST TEXAS. OVERALL PATTERN EXPECTED TO REMAIN QUIET THROUGH MID-WEEK AS HIGH PRESSURE OVER THE MID-GULF AMPLIFIES NORTH IN RESPONSE TO A DEEPENING WEST CONUS TROF.
HIGHS TODAY WILL REACH FROM AROUND 70 TO THE LOWER 70S. AND WHILE THE HIGHER END 30 KNOT GUSTS WILL DIMINISH TOWARD SUNSET. ALTHOUGH SHORT WAVE RIDGING MOVING INTO THE AREA ON TUESDAY AHEAD OF A MORE AMPLIFIED SHORT WAVE FOR MIDWEEK WILL LIMIT THE SOUTHWARD PUSH OF THIS FRONT. BETTER PROXIMITY TO LOW LEVEL THERMAL RIDGE ON TUESDAY WILL PROVIDE MILD MINS AROUND 70 MOST LOCATIONS. CLOSED UPPER LOW WILL MOVE ACROSS SOUTHERN CANADA AND SLOWLY PUSH A FRONTAL BOUNDARY SOUTH INTO THE REGION.
DRY AND WARMER WEATHER IS EXPECTED TUESDAY AND WEDNESDAY AS AN UPPER LEVEL RIDGE BUILDS OVER THE AREA. DEEP UPPER LEVEL TROUGH OVER THE WESTERN US WILL FORM INTO A CUTOFF LOW OVER SOUTHERN CALIFORNIA TODAY. AS THE LOW MOVES EAST INTO ARIZONA AN UPPER LEVEL RIDGE WILL MOVE OVER THE AREA. THE COMBINATION OF THE OFFSHORE FLOW AND THE UPPER RIDGE WILL RESULT IN 5 TO 10 DEGREES OF WARMING TODAY AND WEDNESDAY. THE RIDGE WILL BREAK DOWN LATE IN THE WEEK AND TEMPERATURES WILL LEVEL OFF OR COOL A LITTLE.
250 AM EDT TUE OCT 20 2015 HIGH PRESSURE OVER EAST COAST WITH GRADUALLY MODERATING TEMPERATURES INTO MID WEEK.
THE 500MB PATTERN WILL BECOME MORE AMPLIFIED AS A LARGE TROUGH ACROSS THE WESTERN U.
423 AM CDT TUE OCT 20 2015 THE SURFACE TO 700 MB HIGH PRESSURE RIDGE OVER SE TEXAS WILL RECEDE EASTWARD TODAY AND WEDNESDAY AS AN UPPER LEVEL LOW PRESSURE TROUGH OVER THE ROCKIES AND BAJA CA MOVES EASTWARD. AS THE UPPER TROUGH MOVES OUT WEST SLOWLY EASTWARD. AN UPPER LEVEL LOW IS EXPECTED TO FORM OVER AZ ON WEDNESDAY WITH A DIFFLUENT FLOW DEVELOPING OVER SE TEXAS. THE LOW WILL SHEAR OUT AS IT MOVES INTO THE PLAINS OVER THE NEXT FEW DAYS.
WATER VAPOR LOOP ALSO SHOWING A SHORT WAVE TROUGH OVER BC/ALTA BORDER. COLD FRONT WILL DROP OUT OF CANADA LATE TUE/EARLY WED. PRECIPITABLE WATER RISES TO AROUND A LITTLE UNDER AN INCH BY LATE TUE THEN DROPS OFF WED AFTERNOON WITH COLD FRONTAL PASSAGE. UPPER LEVEL LOW PRESSURE SYSTEM OVER THE DESERT SOUTHWEST WILL MOVE OUT IN THE PLAINS LATE THU.
619 AM EDT TUE OCT 20 2015 A WARM FRONT WILL CROSS THE REGION EARLY THIS MORNING. A COLD FRONT WILL SWEEP SOUTHWARD ACROSS THE AREA THIS AFTERNOON. HIGH PRESSURE BUILDS TONIGHT INTO WEDNESDAY.
123 AM EDT TUE OCT 20 2015 HIGH PRESSURE WILL PROVIDE DRY WEATHER AND WARMER TEMPERATURES THROUGH MIDWEEK.
Cloud cover associated with this wave will hold temperatures down during the morning and even early afternoon hours, but with overnight lows in the lower to even mid 60s, not much of a diurnal rise will be necessary to get temperatures back into the 70s to near 80 by late afternoon once clouds begin to clear out.
607 AM EDT TUE OCT 20 2015 HIGH PRESSURE WILL PROVIDE DRY WEATHER AND WARMER TEMPERATURES THROUGH MIDWEEK.
359 AM EDT TUE OCT 20 2015 HIGH PRESSURE REMAINS OVER THE REGION THROUGH THE MIDDLE OF THE WEEK.
118 AM EDT TUE OCT 20 2015 A COLD FRONT WILL SINK SOUTH OUT OF MICHIGAN OVERNIGHT AND STALL JUST NORTH OF THE LAKE ON TUESDAY.
A LOW PRESSURE SYSTEM WILL BECOME CENTERED NEAR YUMA ARIZONA TODAY AND BRING SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THE MIDDLE OF THE WEEK.
333 AM EDT TUE OCT 20 2015 HIGH PRESSURE REMAINS OVER THE REGION THROUGH MID WEEK.
358 AM EDT TUE OCT 20 2015 HIGH PRESSURE IS FORECAST TO KEEP DRY WEATHER OVER THE AREA TODAY THROUGH WEDNESDAY.
SOUTH AND THEN WESTERLY BY THE LATE AFTERNOON WEST AND OVERNIGHT IN THE EAST AS A 1024MB HIGH PRESSURE BUILDS INTO THE REGION.
Current thinking is that lows in the upper 30s to the lower-mid 40s will prevail. This dry air with slightly warmer temperatures than yesterday will allow afternoon relative humidity values to drop into the 23-29% range. Afternoon highs will range from the upper 60s to the lower 70s across the region with overnight lows cooling into the lower-mid 40s in the east with mid-upper 40s in the west. Highs on Wednesday look to be a little warmer with lower 70s in the east and mid 70s along and west of I-65.
301 AM EDT TUE OCT 20 2015 A COLD FRONT WILL MOVE SOUTH ACROSS THE LOWER GREAT LAKES AND BECOME NEARLY STATIONARY TODAY. THE FRONT WILL LIFT NORTHEAST AS A WARM FRONT WEDNESDAY AS LOW PRESSURE MOVES NORTHEAST THROUGH THE NORTHERN GREAT LAKES.
609 AM EDT TUE OCT 20 2015 A COLD FRONT WILL DROP SLOWLY SOUTH AND EAST ACROSS THE REGION TODAY. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM THE NORTHWEST TONIGHT THROUGH EARLY WEDNESDAY. A WARM FRONT WILL LIFT NORTH THROUGH THE REGION WEDNESDAY NIGHT.
A LOW PRESSURE SYSTEM WILL MAINTAIN UNSETTLED CONDITIONS ACROSS THE REGION THROUGH MIDWEEK.
With the upper ridge building in today, high temperatures will be around 5 degrees warmer than what was observed yesterday. Based on recent trends, also leaned towards the warmer side of guidance for highs this afternoon.
642 AM EDT TUE OCT 20 2015 HIGH PRESSURE IS FORECAST TO KEEP DRY WEATHER OVER THE AREA TODAY THROUGH WEDNESDAY.
EXPECT ANOTHER ROUND OF AREAWIDE SHOWERS AND THUNDERSTORMS LATER TODAY INTO WEDNESDAY AS A LOW PRESSURE SYSTEM MOVES ACROSS THE AREA.
412 AM EDT TUE OCT 20 2015 HIGH PRESSURE WILL PROVIDE DRY WEATHER AND WARMER TEMPERATURES THROUGH MIDWEEK.
and temperatures are already 8-10 degrees warmer than they were at this time yesterday morning. However, would expect the warmer start to the day to mitigate these negative factors so have leaned heavily toward warmest guidance for highs. Limiting factor for preicp continues to be moisture as the low levels remain quite dry.
EXPECT TO SEE THE BREAK FROM PRECIPITATION FOR THE REST OF THE MORNING INTO THE EARLY AFTERNOON WITH WEAK SHORT WAVE RIDGING AND WEAKENING 850 MB WINDS. WHILE GFS KEEPS AREA CLOUDIER AND THUS COOLER.
348 AM EDT TUE OCT 20 2015 HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE END OF THE WEEK. BELOW NORMAL TEMPERATURES WILL MODERATE FOR THE LATTER HALF OF THE WORKWEEK AS AN UPPER-LEVEL RIDGE BUILDS OVER THE AREA. LOWS ARE FORECAST IN THE LOWER AND MIDDLE 30S.
233 AM EDT TUE OCT 20 2015 HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS ACROSS THE AREA THROUGH WEDNESDAY.
408 AM CDT TUE OCT 20 2015 SOUTHEASTWARD MOVING UPPER LOW CURRENTLY JUST WEST OF LOS ANGELES WILL CUTOFF WHILE CROSSING NORTHERN BAJA AND THE GULF OF CALIFORNIA THIS AFTERNOON.
12Z TAFS VERY LITTLE CHANGE EXPECTED TO THE RECENT PATTERN AS DRY AIR AND HIGH PRESSURE HOLD STEADY ACROSS THE REGION.
PARTLY TO MOSTLY CLOUDY SKIES OVER THE AREA AS REMNANTS OF LEE-SIDE TROUGH CONTINUE TO MEANDER OVER THE REGION. AS WIND REGIME BEHIND TROUGH PROVIDING COOLER AIRFLOW ON WNW WINDS. AND A CUTOFF UPPER LOW OVER THE DESERT SW. BY TONIGHT THOUGH MOISTURE FROM WRAPPING AROUND THE CLOSED LOW WILL BEGIN TO FUNNEL UP INTO THE CWA.
334 AM EDT TUE OCT 20 2015 SCATTERED LIGHT TO MODERATE SHOWERS ARE BLAZING QUICKLY WESTWARD OVER THE STRAITS WELL OFFSHORE FROM THE LOWER AND MIDDLE KEYS. SMALLER AND GENERALLY WEAKER SHOWERS HAVE CLIPPED THE LOWER KEYS OVER THE PAST HOUR OR SO. THE MAIN FEATURE FOR THE SHORT AND MID TERMS PORTION OF THE FORECAST IS THE BROAD AND RELATIVELY STRONG HIGH PRESSURE CURRENTLY CENTERED NEAR THE CAROLINA COASTLINE. THIS HIGH PRESSURE WILL KEEP A TIGHT GRADIENT ACROSS THE LOCAL AREA FOR AT LEAST ANOTHER DAY. A SMALL CRAFT ADVISORY WILL REMAIN ACROSS ALL WATERS SURROUNDING THE FLORIDA KEYS TODAY AND TONIGHT THANKS TO A TIGHT GRADIENT BETWEEN A LARGE AREA OF HIGH PRESSURE CURRENTLY NEAR THE CAROLINA COASTLINE AND LINGERING LOWER PRESSURE IN THE WESTERN CARIBBEAN.
H5 TROUGH PROGRESSING SOUTHWARD TOWARD AZ. WHILE WEAK RIDGE REMAINS ACROSS TEXAS. THE TROUGH IS LINING UP THE VALLEY FOR INCREASED MIDLEVEL MOISTURE. BROAD LOW PRESSURE STROLLING UP THE WESTERN GULF OF MEXICO COAST WILL BRING ALONG A SIGNIFICANT AMOUNT OF GULF MOISTURE INTO TEXAS.
236 AM EDT TUE OCT 20 2015 A COLD FRONT WILL DROP SLOWLY SOUTH AND EAST ACROSS THE REGION TODAY. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM THE NORTHWEST TONIGHT THROUGH EARLY WEDNESDAY. A WARM FRONT WILL LIFT NORTH THROUGH THE REGION WEDNESDAY NIGHT.
After another round of morning fog on Wednesday, the afternoon will be warm and dry as high pressure strengthens overhead.
A SMALL UPPER LOW IS CURRENTLY ROTATING INTO SAN DIEGO COUNTY. AT THE SAME TIME NE UPPER LVL FLOW IS SETTING UP OVER THE REST OF CA AS A LARGE EAST PAC RIDGE PUSHES EASTWARD. THE RIDGE PUSHES INTO THE AREA OVERNIGHT AND THE OFFSHORE FLOW INCREASES JUST A BIT. THIS WILL KEEP THE LOW CLOUDS AWAY. JUST AS QUICK AS IT ARRIVED THE UPPER RIDGE MOVES OUT.
The main difference is that 850mb temps will be 1-2 degrees warmer, which will help high temperatures climb a bit more into the upper 60s and lower 70s. Forecast soundings show the potential for some drier air mixing down again Tuesday afternoon, which will help drop dewpoints into the low/mid 30s in spots. This dry air coupled with the warmer temperatures will drop relative humidity values to near 25-30% tomorrow afternoon.
BUT AN UPPER RIDGE MOVING INTO WESTERN WASHINGTON SHOULD BRING SOME SUNSHINE THIS AFTERNOON. A WEAK COLD FRONT COULD PRODUCE A LITTLE RAIN WEDNESDAY.
The winds will be driven by a relatively tight pressure gradient across IL from NW to SE, as our area remains wedged between high pressure in the southeast states and a cold front extending from Lake Superior to western Kansas. The cold front will sag closer to IL this afternoon, with spotty showers or sprinkles possible after 21z/4 pm for areas NW of the Illinois river. High pressure has settled over the southern Atlantic Coast this morning as south/southwesterly flow continues into the Midwest. The warmer temperatures will continue through tomorrow.
236 AM EDT TUE OCT 20 2015 HIGH PRESSURE REMAINS OVER THE REGION THROUGH THE MIDDLE OF THE WEEK.
That front will be driven by a strong upper low that will track over southern Canada, which will not be affected by the southwest trough.
TEMPERATURES ACROSS WESTERN NEBRASKA STILL RANGE IN THE LOWER TO MID 50S. A NORTHERN STREAM TROUGH WILL ADVANCE INTO NWRN NORTH DAKOTA BY LATE THIS AFTERNOON. THE SRN STREAM TROUGH WHICH HAS LINGERED ACROSS THE SWRN U. A THERMAL RIDGE WILL CONTINUE TO BRING VERY MILD TEMPERATURES. A WEAK COLD FRONT WILL SAG THROUGH THE NORTHWESTERN FA BY LATE THIS AFTERNOON. THE APPROACH OF THE UPPER TROUGH AND A PASSING COLD FRONT WILL BRING A CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS TO THE SRN HALF OF THE FA TONIGHT. WITH LOWS FROM THE LOWER 40S SHERIDAN COUNTY TO THE UPPER 80S CENTRAL. COLD FRONT WILL PUSH SOUTH INTO KANSAS WEDNESDAY MORNING.
CURRENT WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES A DEEPENING TROUGH ACROSS THE WESTERN CONUS WITH UPPER LEVEL HEIGHT RISES ACROSS THE CENTRAL AND EASTERN CONUS. THE HIGH PRESSURE CENTER IS LOCATED JUST TO THE EAST OF THE AREA WITH SOUTHERLY FLOW EXPECTED TO CONTINUE TODAY. OVERNIGHT LOWS WILL ALSO BE A BIT WARMER TOMORROW MORNING WITH LOWS IN THE UPPER 30S TO MID 40S. HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE END OF THE WORK WEEK. RIDGE WILL FLATTEN LATE THIS WEEK.
TODAY THROUGH WEDNESDAY NIGHT UPPER TROUGH COVERS THE WESTERN CONUS. UPPER TROUGH WILL SPLIT TODAY. UPPER LOW SPINNING OVER THE SOUTHWESTERN CONUS WILL AFFECT THE REGION LATER IN THE WEEK. HIGHS TODAY WILL RANGE FROM THE LOW 60S ACROSS NORTHEASTERN WY TO THE UPPER 70S ACROSS SOUTH CENTRAL SD. ENERGY FROM UPPER LOW WILL EJECT NORTHWARD INTO NEBRASKA TONIGHT. BUT WITH HIGH PRESSURE PUSHING INTO THE DAKOTAS. UNDER TRANSIENT WEAK UPPER RIDGING ON WEDNESDAY. AND HIGHS WILL BE IN THE LOWER 60S.
An Upper trough over the Great Basin this morning will move south to the US/Mex border by tomorrow then slowly swing east. After this trough weakens and lifts NE a secondary trough will move down over Srn CA. This trough may take a similar track along the border and into the area bringing another shot at rain late in the week.
THE WEATHER PATTERN FEATURING A DEEP LAYER RIDGE LOCKED IN OVER THE ARKLAMISS IS RELATIVELY UNCHANGED WITH PRECIPITABLE WATER REMAINING NEAR OR BELOW AN INCH.
612 AM EDT TUE OCT 20 2015 HIGH PRESSURE INTO MID WEEK.
115 AM EDT TUE OCT 20 2015 HIGH PRESSURE OVER EAST COAST WITH GRADUALLY MODERATING TEMPERATURES INTO MID WEEK.
TEMPERATURES WILL BE COOLER WEDNESDAY AND WEDNESDAY NIGHT BEHIND THE FRONT ACROSS NORTHERN IOWA. THROUGH HAVE KEPT A BIT WARMER IN THE SOUTH WITH CLOUDS EXPECTED TO BE CLEAR NORTH BUT LINGERING SOUTH. ATTENTION THEN TURNS TO BEST CHANCES FOR WIDESPREAD PRECIPITATION AS LOW PRESSURE SYSTEM BEGINS TO LIFT NORTHEAST FROM SOUTHWEST US.
SOUTH AND THEN WESTERLY BY THE LATE AFTERNOON FOR THE WESTERN CWA AND OVERNIGHT IN THE EAST AS A 1024MB HIGH PRESSURE BUILDS INTO THE REGION.
BUT BY MIDDAY THE BETTER ACTIVITY WILL HAVE SPREAD INTO THE EASTERN PORTION OF THE FORECAST AREA AS THE UPPER LOW DROPS INTO THE DESERT SOUTHWEST. UPSTREAM OF THE LOW. THE UPPER JET WILL TAKE AIM ON THE FOUR CORNERS AS IT ROTATES AROUND THE UPPER LOW. THE LOW MEANDERS THROUGH AZ ON WED/WED EVENING BEFORE GRADUALLY LIFTING TO THE NORTHEAST OVERNIGHT AND ON THU. THE MAIN TROUGH WILL BE OVERHEAD ON THU. EXCEPT SHOWERS WILL STILL FAVOR THE HIGHER TERRAIN. AND WILL FORM A TROUGH OVER WESTERN AZ ON FRI. THIS TROUGH WILL THEN EXTEND FROM THE FOUR CORNERS THROUGH AZ FRI NIGHT. WEAK RIDGE WILL DEVELOP NORTH OF THE TROUGH.
321 AM CDT TUE OCT 20 2015 HIGH PRESSURE WAS MOVING THROUGH CENTRAL CANADA AT 0730Z. PLENTY OF HIGH CLOUDS WERE DRIFTING OVER THE FORECAST AREA AHEAD OF LOW PRESSURE IN THE LEE OF THE ROCKIES. A NE FLOW HAS ALREADY DEVELOPED OVER MUCH OF THE REGION IN RESPONSE TO THE HIGH. THE HIGH WILL TRAVEL EASTWARD AND REACH CENTRAL ONTARIO BY 00Z WEDNESDAY. A RIDGE AXIS FROM THE HIGH WILL FORM OVER WESTERN LAKE SUPERIOR BY AFTERNOON. THE DRY AIR FROM THE HIGH WILL COVER THE REGION TODAY. AND MUCH COOLER MAX TEMPS COMPARED TO YESTERDAY. MODELS DO AGREE THAT A DIGGING SHORT WAVE TROF WILL REACH EASTERN ND BY 06Z. MODELS AGREE THAT THE UPPER TROF WILL MOVE INTO MN BY 12Z WEDNESDAY. THE UPPER TROF MOVES EASTWARD WHILE AN UPPER LOW FORMS IN NW ONTARIO.
325 AM EDT TUE OCT 20 2015 UPPER RIDGING THIS MORNING WAS ORIENTED FROM SOUTHWEST TO NORTHEAST FROM THE SOUTHWEST GULF TO THE SOUTHEASTERN CONUS. LOW LEVEL MOISTURE WILL INCREASE TODAY AND TONIGHT WITH DEWPOINTS INCREASING INTO THE LOW TO MID 60S ALONG THE COASTAL AREAS BY TONIGHT. A COASTAL TROUGH WILL DEVELOP OFFSHORE TONIGHT.
HIGH CLOUDS WERE BEGINNING TO ENCROACH UPON WESTERN NORTH DAKOTA AS ENERGY WITHIN AN ELONGATED UPPER LEVEL TROUGH OVER THE WESTERN U. THE AFOREMENTIONED ELONGATED UPPER TROUGH SPLITS WITH THE NORTHERN STREAM ENERGY TRACKING ALONG THE INTERNATIONAL BORDER. WITH THE UPPER TROUGH MOVING EAST OF OUR AREA AFTER MIDNIGHT. COOLER AIR MOVING INTO THE REGION. WITH DRY HIGH PRESSURE OVER THE STATE WEDNESDAY. AND LOWS IN THE LOW TO MID 30S.
300 AM EDT TUE OCT 20 2015 A WARM FRONT WILL CROSS THE REGION EARLY THIS MORNING. A COLD FRONT WILL SWEEP SOUTHWARD ACROSS THE AREA THIS AFTERNOON. HIGH PRESSURE BUILDS TONIGHT INTO WEDNESDAY.
347 AM PDT TUE OCT 20 2015 A DRY OFFSHORE FLOW WILL PREVAIL OVER THE CENTRAL CALIFORNIA INTERIOR TODAY THROUGH WEDNESDAY BETWEEN A STORM SYSTEM OVER THE DESERT SOUTHWEST AND A HIGH PRESSURE RIDGE OVER THE PACIFIC NORTHWEST.
UPPER FLOW ALREADY TRANSITIONING FROM NORTHWESTERLY TO MORE ZONAL AND WEAK UPPER RIDGING BEGINS BUILDING IN OVERNIGHT.
310 AM CDT TUE OCT 20 2015 LATEST WATER VAPOR IMAGERY SHOWS A FAIRLY STRONG UPPER LEVEL TROUGH SITUATED ALONG THE WESTERN US. WHILE A WEAKER UPPER RIDGE CONTINUES TO LINGER OVER THE EASTERN CONUS. THE AXIS OF THE HIGH REMAINS OVER THE SOUTHERN ALTANTIC COAST. WITH MOSTLY CLEAR SKIES AND HIGHS WARMING INTO THE LOW TO MID 70S. AS THE TROUGH OVER THE WEST MOVES EASTWARD AND DEVELOPS INTO A CLOSED LOW BY LATE TONIGHT. THE RIDGE OVER THE SOUTHEAST WILL AMPLIFY.
PROGS THEN LIFT THIS FRONT BACK NORTH AGAIN TONIGHT AS A WARM FRONT AS A STRONG SHORT WAVE TROUGH APPROACHES FROM THE WEST. AND ESPECIALLY LATER TONIGHT AS MID LEVEL LAPSE INCREASE FROM THE WEST WITH THE SHORT WAVE TROUGH APPROACHING. WILL CONTINUE CHANCE POPS FOR WEDNESDAY WITH THE TROUGH AND COLD FRONT PASSAGE.
TEMPERATURES WILL ALSO WARM BACK ABOVE SEASONAL AVERAGES THROUGH MIDWEEK AS AN UPPER LEVEL RIDGE BUILDS ALONG THE CALIFORNIA COAST.
243 AM EDT TUE OCT 20 2015 HIGH PRESSURE REMAINS OVER THE REGION THROUGH MID WEEK.