Aikyam-Lab/Synoptic-Bench huggingface dataset:
633 AM EDT FRI AUG 7 2015 AN UPPER TROUGH AND ASSOCIATED FRONTAL BOUNDARY WILL MOVE EAST OF THE FORECAST AREA BY TONIGHT. DRIER ATMOSPHERE FOR SATURDAY AS WEAK HIGH PRESSURE BUILDS IN FROM THE WEST. MODELS INDICATE UPPER RIDGE WILL SHIFT BACK TO THE WEST SOME. WITH UPPER TROUGH DEEPENING OVER THE E CONUS. UPPER TROUGH AXIS IS CROSSING THE AREA THIS MORNING AND THE SHOWERS ASSOCIATED WITH IT ARE SHIFTING NORTH AND EAST OF THE TERMINALS. WIDESPREAD MVFR CIGS ASSOCIATED WITH THE PASSING UPPER TROUGH WILL LINGER THROUGH MID MORNING BEFORE VFR CIGS RETURN BY 15Z. WINDS WILL PICK UP FROM THE WEST AROUND 10 KNOTS AFTER 15Z THEN A WEAK COLD FRONT WILL CROSS THE REGION AND WINDS WILL SHIFT TO THE NORTHWEST.
TODAY THROUGH SATURDAY NIGHT CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER SOUTHERN SK. ANOTHER AREA OF LOW PRESSURE IS LOCATED ACROSS NORTHWEST WI. A STRONG JET STREAK IS NOTED OVER CENTRAL AND EASTERN MT TO THE SOUTH OF THE LOW. THE BEST CHANCES FOR PCPN STILL LOOK TO BE SATURDAY AFTERNOON INTO SATURDAY NIGHT AS THE REMNANTS OF THE LOW OFF THE CA COAST MOVES NORTHEAST THROUGH THE REGION. COOLER TEMPS CAN BE EXPECTED.
After that, upper level high over the southern plains and southwest conus will expand northeast towards the Ozarks later today and tonight. Expect warmest readings across southeast Kansas into southwest Missouri where highs will be in the lower to middle 90s, and just middle 80s over the eastern Ozarks. A warm and humid night is in store tonight with lows in the lower to middle 70s.
AND A DEEP BUT NARROW RIDGE ACROSS THE KEYS AND NORTHWEST BAHAMAS.
321 AM EDT FRI AUG 7 2015 AN UPPER LOW WILL CONTINUE TO SLOWLY PULL AWAY FROM THE REGION WHILE WEAK HIGH PRESSURE BUILDS AT THE SURFACE. LOW PRESSURE WILL TRACK SOUTH OF THE AREA ON SATURDAY. MODELS ARE STILL IN AGREEMENT ABOUT A WEAK BROAD UPPER TROF OVR ERN QB XTNDG SWRD INTO THE N HLF OF THE FA THRU SAT. WHATS LEFT OF THE UPPER TROF WILL MOVE E OF THE FA LATER SAT NGT INTO SUN. ADDITIONAL S/WV ENERGY DIGGING SE FROM CNTRL CAN COULD RESULT IN THE FORMATION OF AN UPPER LOW OVR SRN QB BY LATE WED INTO WED NGT. AND TO A LESSER DEGREE THU AFTN A THE UPPER LOW REMAINS IN PLACE OVR SRN QB. A WEAK RIDGE OF HIGH PRESSURE OVER THE WATERS WILL KEEP WINDS AND SEAS BELOW SMALL CRAFT LEVELS.
AN UPPER LEVEL LOW PRESSURE SYSTEM IS NEAR SAN FRANCISCO BAY EARLY THIS MORNING.
An upper level wave is forecast to eject from a strong upper trough over the northern Rockies and initiate convection well to the north of forecast area in the Dakotas. Upper level ridging shifts east and amplifies slightly heading into the weekend.
UPPER LOW CURRENTLY OFF THE CALIFORNIA COAST WILL MOVE NORTHEAST TONIGHT AND FRIDAY. A MUCH LARGER UPPER LOW CURRENTLY IN THE GULF OF ALASKA WILL APPROACH THE PACIFIC NORTHWEST THIS WEEKEND.
WEAK SURFACE TROF AND LIGHT STEERING CURRENT TODAY.
403 AM EDT FRI AUG 7 2015 HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH THE WEEKEND BRINGING DRY CONDITIONS AND COMFORTABLE TEMPERATURES.
JUST SOME ISOLD ACTIVITY POSSIBLE ACROSS THE FAR SE AND THE HIGHER ELEVATIONS OF THE NE.
THE LOW WILL GRADUALLY EXIT OFF TO THE EAST TODAY. BETTER CLEARING WILL TAKE PLACE TONIGHT AS UPPER LEVEL RIDGING ENSUES. THE PERIOD BEGINS WITH UPPER LEVEL HIGH RETROGRADING EAST IN THE ARKLATEX REGION. THIS WILL BRING HEIGHT RISES TO THE REGION AND TRANSLATE TO WARMER AND MORE HUMID AIR AT THE SURFACE.
328 AM EDT FRI AUG 7 2015 AN UPPER LOW WILL CONTINUE TO SLOWLY PULL AWAY FROM THE REGION WHILE WEAK HIGH PRESSURE BUILDS AT THE SURFACE. LOW PRESSURE WILL TRACK SOUTH OF THE AREA ON SATURDAY. MODELS ARE STILL IN AGREEMENT ABOUT A WEAK BROAD UPPER TROF OVR ERN QB XTNDG SWRD INTO THE N HLF OF THE FA THRU SAT. WHATS LEFT OF THE UPPER TROF WILL MOVE E OF THE FA LATER SAT NGT INTO SUN. ADDITIONAL S/WV ENERGY DIGGING SE FROM CNTRL CAN COULD RESULT IN THE FORMATION OF AN UPPER LOW OVR SRN QB BY LATE WED INTO WED NGT. AND TO A LESSER DEGREE THU AFTN AS THE UPPER LOW REMAINS IN PLACE OVR SRN QB. A WEAK RIDGE OF HIGH PRESSURE OVER THE WATERS WILL KEEP WINDS AND SEAS BELOW SMALL CRAFT LEVELS.
532 AM EDT FRI AUG 7 2015 AN UPPER LOW WILL CONTINUE TO SLOWLY PULL AWAY FROM THE REGION WHILE WEAK HIGH PRESSURE BUILDS AT THE SURFACE. LOW PRESSURE WILL TRACK SOUTH OF THE AREA ON SATURDAY. MODELS ARE STILL IN AGREEMENT ABOUT A WEAK BROAD UPPER TROF OVR ERN QB XTNDG SWRD INTO THE N HLF OF THE FA THRU SAT. WHATS LEFT OF THE UPPER TROF WILL MOVE E OF THE FA LATER SAT NGT INTO SUN. ADDITIONAL S/WV ENERGY DIGGING SE FROM CNTRL CAN COULD RESULT IN THE FORMATION OF AN UPPER LOW OVR SRN QB BY LATE WED INTO WED NGT. AND TO A LESSER DEGREE THU AFTN AS THE UPPER LOW REMAINS IN PLACE OVR SRN QB. A WEAK RIDGE OF HIGH PRESSURE OVER THE WATERS WILL KEEP WINDS AND SEAS BELOW SMALL CRAFT LEVELS.
UPPER LOW THAT BROUGHT COOL TEMPERATURES AND PRECIP TO THE AREA HAS QUICKLY MOVED NORTH AND IS CURRENTLY LOCATED NEAR THE IDAHO PANHANDLE. KEPT FOG IN THE FORECAST FOR AREAS NEAR BAKER CITY AND MCCALL AND IN THE LOWEST ELEVATIONS OF THE SNAKE PLAIN.
STRONG COLD FRONT WILL BE PUSHING SOUTHEAST THROUGH EASTERN MONTANA THIS EVENING. AND A THIRD COMPLEX ACROSS NORTHWEST NORTH DAKOTA ON THE APEX OF THE LOW LEVEL JET WHERE WARM AIR ADVECTION IS BEING MAXIMIZED. 12 UTC NAM NEST AND 12 UTC WRF-ARW/NMM RUNS ALL SHOW A CONVECTIVE COMPLEX PROPAGATING OUT OF MONTANA INTO WESTERN NORTH DAKOTA ASSOCIATED WITH STRONG DIFFLUENCE AHEAD OF THE DEEPENING UPPER LEVEL LOW ACROSS SOUTHEAST ALBERTA. WITH A COOLER.
HIGH PRESSURE WILL REBUILD OVER THE WEST LEADING TO VERY WARM AND DRY CONDITIONS FOR THE UPCOMING WEEK. LOWS IN THE COLDER SIERRA VALLEYS (TRUCKEE, BODIE, BRIDGEPORT TO NAME A FEW) MAY DIP INTO THE UPPER TEENS. WARMER WEATHER RETURNS TOMORROW AS HIGH PRESSURE REBUILDS OVER THE SOUTHWEST.
AND WITH IT THE HIGHEST COVERAGE OF SHOWERS AND STORMS.
MAIN CONTRIBUTING FACTORS TO THIS IS THE UNSEASONABLE LOW LEVEL HEAT AND THE SLIGHTLY COOLER TEMPERATURES WELL ALOFT THANKS TO A LARGE UPPER LOW RETROGRADING TOWARD THE REGION FROM THE EAST. GRADUALLY BUILDING MOIST LOW LEVEL EASTERLY FLOW TIED TO THE INCOMING UPPER LOW COULD PRODUCE ENOUGH MOISTURE TRANSPORT TO FUEL SOME CONVECTION NEAR THE COAST THROUGH THE NIGHT.
332 PM CDT SAT SEP 5 2015 South to southwest deep layer flow will continue into Sunday afternoon, though changes begin to take shape late in the day as the Pacific NW wave makes eastward progress and brings a cold front near the area late in the day. Somewhat more veered 850mb flow will boost temps both tonight and Sunday with lows only the lower and middle 70s and highs in the middle and upper 90s, both around 5 degrees below record values. As a upper level trough moves northeast into Canada Sunday night with the southward extension moving across the Northern Plains. This will gradually move a cold frontal boundary into north central Kansas during the late evening and overnight hours.
AN APPROACHING TROUGH WILL BRING COOLER MID AND UPPER LEVEL AIR INTO THE AREA.
LOW PRESSURE OVER THE NORTHERN PLAINS AND A FRONTAL BOUNDARY EXTENDING NORTHEAST INTO NORTHWEST MINNESOTA THIS AFTERNOON WILL START TO MOVE EAST TONIGHT AND MORE SO SUNDAY INTO SUNDAY NIGHT. 74" WHICH IS THE HIGHEST REPORTED ON THIS DATE. WE DO EXPECT MORE STORMS TO DEVELOP ALONG THE EASTWARD MOVING COLD FRONT THROUGH THE DAY.
SHOWERS HAVE TAPERED OFF AS THE UPPER LEVEL RIDGE THAT BROUGHT SHOWERS AND THUNDERSTORMS CONTINUED TO MOVE EAST OF THE REGION. WITH THE COLDER AIR MASS OVER THE AREA AND CLEARING THIS WILL BRING ANOTHER NIGHT OF UNSEASONABLY COLD TEMPERATURES EAST OF THE CASCADES A WEAK COLD FRONT BRUSHES THE NORTHERN PORTIONS OF THE WEST SIDE SUNDAY MORNING ON THE LEFT EXIT REGION OF A 70 KT JET.
522 PM EDT SAT SEP 5 2015 HIGH PRESSURE WILL ENSURE MAINLY DRY WEATHER FOR LABOR DAY WEEKEND WITH ABOVE NORMAL WARMTH AND JUST THE CHANCE OF AN AFTERNOON OR EVENING POP-UP SHOWER OR THUNDERSTORM. THE PATTERN WILL START TO CHANGE IN THE MIDDLE OF THE WEEK AS THE UPPER LEVEL FLOW FLATTENS OUT AND A COLD FRONT DROPS DOWN FROM THE NORTH. A MORE SOUTHERLY COMPONENT TO THE LOW LEVEL FLOW ON SUNDAY WILL ALLOW ANY MORNING CLOUDS TO DISSIPATE AREAWIDE.
TEMPS IN THE LOWER 80S THIS EVENING WILL ONLY FALL INTO THE MID/UPPER 70S BY DAYBREAK. /ISSUED 333 PM CDT SAT SEP 5 2015/ LATEST UA ANALYSIS AND WV IMAGERY SHOW RIDGING OVER WRN TX WITH A WEAK TROF ACRS THE LOWER APPALACHIANS AND THE CAROLINAS. NLY FLOW WAS PREVAILING ALOFT OVER THE LOWER MS VALLEY. A HIGH PRES RIDGE OVER THE GULF COAST WAS PROVIDING A S-SWLY FLOW OF GULF MOISTURE INTO THE AREA. THE REGION WILL REMAIN UNDER NLY FLOW ALOFT BETWEEN UPPER RIDGE OVER TX AND LOW PRES OVER THE SE. MAINTAINING A LIGHT VRBL OR SLY FLOW AND AN INFLUX OF GULF MOISTURE IN THE LOWER LEVELS. THE LOW OVER THE SE CONUS WILL SLOWLY RETROGRADE THROUGH THE UPCOMING WEEK.
A BROAD UPPER LEVEL RIDGE EXTENDS FROM THE CENTRAL PLAINS TO THE EAST COAST. ALONG THE NORTHERN FRINGE OF THE THIS RIDGE IS A CUT-OFF LOW OVER THE GREAT LAKES STATES. THERE IS ANOTHER WEAK UPPER LEVEL LOW FEATURE LOCATED OFF THE GA/SC COAST. WHAT IS EXPECTED TO HAPPEN IS A SECONDARY HIGH WILL FORM EAST OF THE CUT-OFF LOW OVER THE NERN U. THIS WILL WEAKEN THE CUT-OFF LOW AND PUSH THE WEAK FEATURE OFF THE GA/SC COAST WESTWARD INTO THE TN/LOWER MS VALLEYS TODAY INTO SUNDAY. AS THIS HAPPENS THE LOW/MID LEVEL FLOW SHIFTS TO THE E/SE AND WILL PULL IN SOME LIMITED MOISTURE OFF OF THE ATLANTIC.
333 PM CDT SAT SEP 5 2015 LATEST UA ANALYSIS AND WV IMAGERY SHOW RIDGING OVER WRN TX WITH A WEAK TROF ACRS THE LOWER APPALACHIANS AND THE CAROLINAS. NLY FLOW WAS PREVAILING ALOFT OVER THE LOWER MS VALLEY. A HIGH PRES RIDGE OVER THE GULF COAST WAS PROVIDING A S-SWLY FLOW OF GULF MOISTURE INTO THE AREA. THE REGION WILL REMAIN UNDER NLY FLOW ALOFT BETWEEN UPPER RIDGE OVER TX AND LOW PRES OVER THE SE. MAINTAINING A LIGHT VRBL OR SLY FLOW AND AN INFLUX OF GULF MOISTURE IN THE LOWER LEVELS. THE LOW OVER THE SE CONUS WILL SLOWLY RETROGRADE THROUGH THE UPCOMING WEEK.
248 PM MDT SAT SEP 5 2015 SOUTHWEST FLOW ALOFT WILL PREVAIL THROUGH SUNDAY AS AN UPPER LEVEL LOW MOVES ACROSS THE NORTHERN ROCKIES WHILE A RIDGE RESIDES OVER THE SOUTHERN PLAINS. WILL KEEP SCATTERED STORMS OVER THE HIGHER TERRAIN WITH ISOLATED POPS FOR THE FRONT RANGE AND EASTERN PLAINS THROUGH EARLY EVENING. AS HIGH PRESSURE BUILDS IN BEHIND IT. TEMPERATURES WILL BE A FEW DEGREES COOLER ON SUNDAY WITH HIGHS IN THE LOWER TO MID 80S ACROSS NORTHEAST COLORADO. COLORADO REMAINS UNDER SWLY FLOW ALOFT IN BETWEEN A DEEP UPPER TROUGH OVER THE PACIFIC NORTHWEST/NORTHERN ROCKIES AND LARGE UPPER RIDGE OVER SOUTH-CENTRAL/SOUTHEAST U. MODELS SHOW WEAK NELY/UPSLOPE FLOW OVER NERN COLORADO AFTER PASSAGE OF A WEAK COLD FRONT EARLY SUNDAY MORNING.
UPPER RIDGE GETS STRONGER WITH LESS MOISTURE TO WORK WITH ON SUNDAY. THEN BEGINS TO WEAKEN AS UPPER LOW RETROGRADES TOWARD AREA (BUT STILL STAYS TO THE WEST) SUNDAY NIGHT. THEN POSSIBLY A SLIGHT CHANCE FOR SHOWERS LATE SUNDAY NIGHT WITH THE BETTER MOISTURE AND THE APPROACHING UPPER LOW. CONTINUED HOT AND HUMID FOR LABOR DAY AS MID LEVEL RIDGE IS PROG TO REMAIN STRONG ACROSS TEXAS.
719 PM EDT SAT SEP 5 2015 HIGH PRESSURE WILL ENSURE MAINLY DRY WEATHER FOR LABOR DAY WEEKEND WITH ABOVE NORMAL WARMTH AND JUST THE CHANCE OF AN AFTERNOON OR EVENING POP-UP SHOWER OR THUNDERSTORM. THE PATTERN WILL START TO CHANGE IN THE MIDDLE OF THE WEEK AS THE UPPER LEVEL FLOW FLATTENS OUT AND A COLD FRONT DROPS DOWN FROM THE NORTH. THE LOW CLOUDS WHICH MOVED IN COURTESY OF THE MARITIME FLOW. A MORE SOUTHERLY COMPONENT TO THE LOW LEVEL FLOW ON SUNDAY WILL ALLOW ANY MORNING CLOUDS TO DISSIPATE AREA-WIDE.
A TROUGH OF LOW PRESSURE WILL RESULT IN A DRY SOUTHWESTERLY FLOW TO MUCH OF THE REGION ALONG WITH NEAR NORMAL TEMPERATURES THROUGH LABOR DAY.
WITH THE FILTERED SUNSHINE AND COOLER THAN EXPECTED TEMPERATURES. THE LOW LEVEL JET ONCE AGAIN KICKS IN LATE TONIGHT AND WILL LIKELY REIGNITE SHOWERS AND STORMS. BY MID MORNING THE LOW LEVEL JET WEAKENS. HOWEVER A COLD FRONT IS EXPECTED TO PUSH INTO THE WESTERN FORECAST AREA AND GRADUALLY TRACK SOUTHEAST THROUGH THE FORECAST AREA INTO THE AFTERNOON. EXPECT MOST PLACES TO REACH THE LOW TO MID 80S.
IN THE LOW LEVELS OF THE ATMOSPHERE. A TROUGH OF LOW PRESSURE WILL BE LOCATED OVER SOUTH FLORIDA OVERNIGHT. AN AREA OF LOW PRESSURE WILL BE CENTERED JUST NORTH OF THE BAHAMAS TONIGHT. A TROUGH OF LOW PRESSURE WILL DEEPEN OVER THE EASTERN GULF OF MEXICO OVERNIGHT.
AND A TROUGH EXTENDING FROM WEAK LOW OVER NORTHEAST WY/WESTERN SD INTO WESTERN KS. TOUGH LOOKING UPPER LOW/TROUGH SPINNING OVER NORTHERN ID. CONVECTIVE POTENTIAL AHEAD OF THE UPPER TROUGH MAIN QUESTION WITH SIGNIFICANT DRY SLOT EXPECTED TO PLOW THROUGH CWA THIS EVENING.
AS MOST OF THE LOW/MID CLOUDS ARE SHOWING SIGNS OF ALSO DISSIPATING.
EAST/WEST ORIENTED LOW-LEVEL TROUGH VICINITY FAR NORTH BAHAMAS WILL SLOWLY WEAKEN BUT WITH HIGH PRESSURE ALONG THE EASTERN SEABOARD. THE GREATEST CHANCE SHOULD BE ALONG THE TREASURE COAST WHICH IS CLOSEST TO THE LOW LEVEL BOUNDARY. SO THE HIGHEST COASTAL CHANCES SHOULD BE SOUTH OF CANAVERAL. MID LEVEL TROUGH IS FORECAST TO CUT OFF OVER SOUTH GEORGIA AND NORTH FLORIDA ON SUNDAY. THE GFS IS SHOWING COOLER TEMPS ALOFT AS A RESULT WITH 500 MB READINGS -8 TO -9 CELSIUS.
TWO MORE VERY WARM AND HUMID DAYS ARE EXPECTED TO ROUND OUT THE LABOR DAY WEEKEND WITH HIGHS AROUND 90 DEGREES AND HEAT INDICES IN THE LOWER TO MID 90S. KEPT THE FORECAST DRY FOR NOW AS THE UPPER LEVEL RIDGE BUILDS INTO THE AREA. HIGHS SHOULD BE NEAR 90 WITH HEAT INDICES IN THE LOW TO MID 90S.
A WEAK LOW PRESSURE SYSTEM WILL BRING RAIN TO THE AREA TONIGHT THROUGH SUNDAY. EXPECT WEAK HIGH PRESSURE ALOFT TO FOLLOW ON LABOR DAY.
404 PM EDT SAT SEP 5 2015 DRY WEATHER CONTINUES THIS HOLIDAY WEEKEND UNDER HIGH PRESSURE ALONG WITH ABOVE NORMAL TEMPERATURES.
46 WEAK HIGH PRESSURE FROM 500 TO 200 MB OVER WESTERN TEXAS PUT A NORTHERLY FLOW OVER SE TEXAS THIS AFTERNOON. WHILE THE LOWER LEVEL FLOW WAS OUT OF THE SOUTH AND SOUTHEAST.
319 PM CDT SAT SEP 5 2015 WEAK HIGH PRESSURE FROM 500 TO 200 MB OVER WESTERN TEXAS PUT A NORTHERLY FLOW OVER SE TEXAS THIS AFTERNOON. WHILE THE LOWER LEVEL FLOW WAS OUT OF THE SOUTH AND SOUTHEAST.
SKIES ARE MOSTLY CLEAR AS AN UPPER RIDGE OF HIGH PRESSURE REMAINS OVER THE AREA. /ISSUED 315 PM CDT SAT SEP 5 2015/ SKIES REMAIN MOSTLY SUNNY ACROSS MUCH OF THE FORECAST AREA THIS AFTERNOON WITH TEMPERATURES IN THE LOW TO MID 90S.
DRY SLOT WORKING INTO JAMESTOWN-HARVEY-BISMARCK AREA AND SOME FOG IS FORMING NEAR THE LOW IN THAT AREA. WV LOOP CURRENTLY SHOWS THE MAIN UPPER LOW STILL OUT OVER IDAHO. BUT TEMPS HAVE MANAGED TO REACH THE LOW 80S AND SPC MESOANALYSIS HAS SOME GREATER THAN 2000 J/KG ML CAPE WITH THE CAP ALMOST GONE.
ITS HARD TO PINPOINT WHERE THE HIGHEST RAIN CHANCES MIGHT BE OVER THE NEXT FEW HOURS. GIVEN THE PRESENCE OF THE TROF A LITTLE UPPER LEVEL SUPPORT LOOKS TO KEEP AT LEAST LIGHT DEBRIS RAIN WITH AN EMBEDDED STORMS OR TWO WILL BE POSSIBLE FOR MOST OF THE AREA THROUGH LATE EVENING. AND WITH IT THE HIGHEST COVERAGE OF SHOWERS AND STORMS.
LATEST WATER VAPOR IMAGERY AND 500 MB HEIGHTS SHOWS BROAD LARGE SCALE RIDGING FROM SOUTHERN TEXAS INTO NEW ENGLAND. HIGH PRESSURE OFF THE NEW ENGLAND COAST PROVIDED THE REGION WITH A LIGHT EASTERLY FLOW WHILE READINGS SO FAR THIS AFTERNOON HAVE CLIMBED INTO THE LOWER 90S. A REPEAT PERFORMANCE ON SUNDAY AS THE UPPER RIDGES HOLDS STRONG OVER THE REGION. BLENDING PERSISTENCE WITH THE HIGHEST PERFORMING BIAS- CORRECTED GUIDANCE YIELDS HIGHS ONCE AGAIN IN THE 89 TO 95 RANGE.
DRY WEATHER IS EXPECTED ON SUNDAY AS RESIDENT UPPER LOW OPENS AND LIFTS EAST OUT OF THE AREA AND A FLAT UPPER RIDGE AXIS SHIFTS EAST OVER THE CENTRAL GREAT LAKES. WITH SURFACE RIDGING STILL EXTENDING WEST INTO THE AREA FROM EAST COAST HIGH PRESSURE. WARM CONDITIONS WILL PERSIST SUNDAY NIGHT AS THE PRESSURE GRADIENT BEGINS TO TIGHTEN SOMEWHAT AS A COLD FRONT ENCROACHES ON THE AREA FROM THE WEST.
1129 PM EDT SAT SEP 5 2015 HIGH PRESSURE WILL ENSURE MAINLY DRY WEATHER FOR LABOR DAY WEEKEND WITH ABOVE NORMAL WARMTH AND JUST THE CHANCE OF AN AFTERNOON OR EVENING POP-UP SHOWER OR THUNDERSTORM. THE PATTERN WILL START TO CHANGE IN THE MIDDLE OF THE WEEK AS THE UPPER LEVEL FLOW FLATTENS OUT AND A COLD FRONT DROPS DOWN FROM THE NORTH. THE LOW CLOUDS HAVE PRETTY MUCH ALL MELTED AWAY AS OF MID EVENING. A MORE SOUTHERLY COMPONENT TO THE LOW LEVEL FLOW ON SUNDAY WILL ALLOW ANY MORNING CLOUDS TO DISSIPATE AREA-WIDE.
A COLD FRONT WILL ALSO BE ENTERING NORTHEAST NEBRASKA SUNDAY MORNING. TEMPS SHOULD AGAIN REACH THE LOWER 90S.
HOWEVER, A THERMAL TROUGH ALONG THE COAST WILL STRENGTHEN SUNDAY EVENING AND THEN REMAIN IN PLACE THROUGH MUCH OF THE UPCOMING WEEK.
South to southwest deep layer flow will continue into Sunday afternoon, though changes begin to take shape late in the day as the Pacific NW wave makes eastward progress and brings a cold front near the area late in the day. Somewhat more veered 850mb flow will boost temps both tonight and Sunday with lows only the lower and middle 70s and highs in the middle and upper 90s, both around 5 degrees below record values. As a upper level trough moves northeast into Canada Sunday night with the southward extension moving across the Northern Plains. This will gradually move a cold frontal boundary into north central Kansas during the late evening and overnight hours.
WV LOOP CURRENTLY SHOWS THE MAIN UPPER LOW STILL OUT OVER IDAHO. BUT TEMPS HAVE MANAGED TO REACH THE LOW 80S AND SPC MESOANALYSIS HAS SOME GREATER THAN 2000 J/KG ML CAPE WITH THE CAP ALMOST GONE.
CONDITIONS STILL FAVORABLE FOR A PERIOD OF SEVERE WX LATE THIS AFTERNOON AND EVENING AS APPROACHING PACIFIC TROF INTERACTS WITH A MOIST AND UNSTABLE AIRMASS WITH AMPLE SHEAR.
AN UPPER TROF OVER THE WESTERN ATLANTIC AND EXTREME SOUTHEAST STATES SHIFTS WESTWARD AND EVOLVES INTO AN UPPER LOW OVER THE SOUTHEAST STATES BY SUNDAY. A LONGWAVE RIDGE OVER THE PLAINS AND SOUTH CENTRAL STATES RETREATS SLIGHTLY WESTWARD MEANWHILE. MODEL SOUNDINGS SHOW A RELATIVELY WARM LAYER APPROXIMATELY BETWEEN 700 AND 400 MB WHICH IS MORE PRONOUNCED OVER THE WESTERN PORTION OF THE AREA AND IS ASSOCIATED WITH FRINGE EFFECTS OF THE LONGWAVE RIDGE WEST OF THE REGION. SBCAPE VALUES ON SUNDAY WILL RANGE FROM UP TO 2000 J/KG OVER THE INTERIOR EASTERN PORTION DUE TO MORE FAVORABLE CONVECTIVE ENVIRONMENT WITH THE LIMITED BY WARMER MID LEVEL TEMPERATURES. LOWS TONIGHT WILL RANGE FROM THE LOWER 70S INLAND TO THE MID 70S NEAR THE COAST. HIGHS ON SUNDAY WILL BE MOSTLY IN THE LOWER 90S.
SUNDAY NIGHT THE NEXT TROUGH WORKS THROUGH THE NORTHERN ROCKIES FOR SOME FORCING NEAR THE WYOMING BORDER.
THEY ARE MOVING SLOWLY SOUTH AROUND THE EAST SIDE OF THE UPPER LEVEL RIDGE CENTERED IN EASTERN TEXAS. THE UPPER LEVEL RIDGE WILL RETROGRADE TO THE WEST AS A WEAK CUT OFF UPPER LEVEL LOW DEVELOPS OVER THE SOUTHEAST U. THIS UPPER LEVEL LOW WILL MIGRATE SLOWLY SOUTHWEST THROUGH THE LABOR DAY WEEKEND. AS THE UPPER LEVEL LOW MOVES WEST OF THE FORECAST AREA BY MID WEEK THERE WILL BE AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE REGION.
959 PM EDT SAT SEP 5 2015 THE NEAR TERM SECTION HAS BEEN UPDATED BELOW HOT AND HUMID WEATHER IE EXPECTED TO CONTINUE THROUGH LABOR DAY AS WEAK BUT BROAD HIGH PRESSURE OVER THE MIDDLE ATLANTIC STATES CONTINUES TO PROVIDE WARM.
DESPITE THE UPPER LEVEL RIDGE REMAINING IN PLACE. AS THE UPPER LEVEL HIGH MOVES A BIT CLOSER TO NORTH TEXAS. AS THE UPPER HIGH KEEPS THE DEEPEST MOISTURE IN THE EASTERN THIRD OF THE REGION. BUT THE HOT AND HUMID CONDITIONS WILL BE THE HIGHER RISK FOR ANYONE OUTDOORS. FOCUS THEN TURNS TO THE WEAKENING OF THE UPPER HIGH AND THE PROGRESS OF THE NEXT COLD FRONT.
WE ARE LOOKING AT PWATS WELL OUTSIDE THE NORM AND WET BULB FREEZING LEVELS UPWARDS OF 14KFT. AS THE UPPER LOW TRANSITIONS FROM THE NORTHERN ROCKIES INTO THE NORTHERN PLAINS/SOUTHERN CANADA. THIS FEATURE DISLODGES THE COOLER AIR TO THE WEST.
332 PM CDT SAT SEP 5 2015 South to southwest deep layer flow will continue into Sunday afternoon, though changes begin to take shape late in the day as the Pacific NW wave makes eastward progress and brings a cold front near the area late in the day. Somewhat more veered 850mb flow will boost temps both tonight and Sunday with lows only the lower and middle 70s and highs in the middle and upper 90s, both around 5 degrees below record values. This will gradually move a cold frontal boundary into north central Kansas during the late evening and overnight hours.
315 PM CDT SAT SEP 5 2015 SKIES REMAIN MOSTLY SUNNY ACROSS MUCH OF THE FORECAST AREA THIS AFTERNOON WITH TEMPERATURES IN THE LOW TO MID 90S.
A REGION-WIDE WARMING TREND IS FORECAST TO CONTINUE THROUGH LABOR DAY AS HIGH PRESSURE BUILDS OVER THE STATE AND LIGHT OFFSHORE FLOW PERSISTS. THE FORECAST FOR THE REMAINDER OF THE HOLIDAY WEEKEND CALLS FOR WARMER TEMPERATURES AS HIGH PRESSURE BEGINS TO STRENGTHEN NEAR THE WEST COAST AND LIGHT OFFSHORE FLOW PERSISTS.
1016 PM EDT SAT SEP 5 2015 HIGH PRESSURE WILL ENSURE MAINLY DRY WEATHER FOR LABOR DAY WEEKEND WITH ABOVE NORMAL WARMTH AND JUST THE CHANCE OF AN AFTERNOON OR EVENING POP-UP SHOWER OR THUNDERSTORM. THE PATTERN WILL START TO CHANGE IN THE MIDDLE OF THE WEEK AS THE UPPER LEVEL FLOW FLATTENS OUT AND A COLD FRONT DROPS DOWN FROM THE NORTH. THE LOW CLOUDS HAVE PRETTY MUCH ALL MELTED AWAY AS OF MID EVENING. A MORE SOUTHERLY COMPONENT TO THE LOW LEVEL FLOW ON SUNDAY WILL ALLOW ANY MORNING CLOUDS TO DISSIPATE AREA-WIDE.
THIS CONVECTION WAS BEING DRIVEN BY A RATHER STRONG MID LVL TROUGH WHICH WAS LOCATED OVER THE NORTHWESTERN CONUS. GUSTY SOUTHWEST FLOW WAS NOTED OVER MOST OF THE REGION AND TEMPS RANGED FROM 80 AT KCOS TO MID 90S ACROSS THE LOWER ARK RVR VALLEY. A LEE TROUGH WAS NOTED EXTENDING NE-SW. AND ALONG THE LEE TROUGH OVER THE PLAINS. FLOW ALOFT WILL WEAKEN A BIT AS THE TROUGH LIFTS OFF TO OUR NORTHEAST.
HOT AND HUMID WEATHER IE EXPECTED TO CONTINUE THROUGH LABOR DAY AS WEAK BUT BROAD HIGH PRESSURE OVER THE MIDDLE ATLANTIC STATES CONTINUES TO PROVIDE WARM.
1032 PM EDT SAT SEP 5 2015 HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH THE HOLIDAY WEEKEND.
748 PM EDT SAT SEP 5 2015 HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH THE HOLIDAY WEEKEND.
TONIGHT AND SUNDAY THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE CENTERED OVER NORTHWEST ONTARIO AND A CONNECTING COLD FRONT RUNNING SOUTHWEST FROM THE LOW ACROSS THE DAKOTAS. FOLLOWED BY THE COLD FRONT LATE ON SUNDAY. MID-LEVEL RIDGING WILL HANG OVERHEAD FOR MUCH OF THE NIGHT. AS A COLD FRONT MOVES INTO THE NORTHERN MISSISSIPPI VALLEY.
ALTHOUGH SOME DOWNSLOPE BREEZES WILL KEEP WARMER TEMPS NEAR THE FOOTHILLS. SOUTHWEST FLOW ALOFT WILL PREVAIL THROUGH SUNDAY AS AN UPPER LEVEL LOW MOVES ACROSS THE NORTHERN ROCKIES WHILE A RIDGE RESIDES OVER THE SOUTHERN PLAINS. WILL KEEP SCATTERED STORMS OVER THE HIGHER TERRAIN WITH ISOLATED POPS FOR THE FRONT RANGE AND EASTERN PLAINS THROUGH EARLY EVENING. AS HIGH PRESSURE BUILDS IN BEHIND IT. TEMPERATURES WILL BE A FEW DEGREES COOLER ON SUNDAY WITH HIGHS IN THE LOWER TO MID 80S ACROSS NORTHEAST COLORADO. COLORADO REMAINS UNDER SWLY FLOW ALOFT IN BETWEEN A DEEP UPPER TROUGH OVER THE PACIFIC NORTHWEST/NORTHERN ROCKIES AND LARGE UPPER RIDGE OVER SOUTH-CENTRAL/SOUTHEAST U. MODELS SHOW WEAK NELY/UPSLOPE FLOW OVER NERN COLORADO AFTER PASSAGE OF A WEAK COLD FRONT EARLY SUNDAY MORNING.
CHATTANOOGA AIRPORT, TN 70 89 69 88 / 30 30 20 20 KNOXVILLE MCGHEE TYSON AIRPORT, TN 68 87 66 87 / 30 30 10 20 OAK RIDGE, TN 68 87 66 87 / 30 30 10 20 TRI CITIES AIRPORT, TN 64 85 63 85 / 30 20 20 20.
302 PM CDT SAT SEP 5 2015 POSITIVELY TILTED UPPER LEVEL RIDGING WILL CONTINUE TO CONTROL THE WEATHER LOCALLY THROUGH SUNDAY EVEN AS THE NORTHWESTERN CONUS STORM SYSTEM TRANSLATES INTO ALBERTA AND SASKATCHEWAN. BUT WATER VAPOR ALSO SHOWS DRIER MID/UPPER AIR ADVANCING TOWARD THE REGION WITHIN THE RIDGE FROM THE SOUTHWEST. THOUGH PERHAPS A DEGREE OR TWO WARMER VERSUS THE LAST 24 HOURS FOR BOTH LOWS TONIGHT AND HIGHS TOMORROW. GENERAL EVOLUTION OF THE UPPER PATTERN REMAINS ONE FROM WRN CONUS TROUGH AND RIDGING OVER WEST TEXAS TO A FLAT RIDGE OVER THE WEST TEXAS AS THE TROUGH MOVES ONTO THE NRN PLAINS TO AN AMPLIFYING RIDGE ALONG THE WEST COAST.