Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/03/15


AREA FORECAST DISCUSSION
NWS PHOENIX AZ
854 PM MST SAT MAY 2 2015 .SYNOPSIS...A SERIES OF PACIFIC WEATHER DISTURBANCES IS FORECAST TO MOVE INTO THE REGION THROUGH TUESDAY...RESULTING IN A COOLING TREND. ENOUGH MOISTURE WILL BE PRESENT FOR A SLIGHT CHANCE OF AFTERNOON AND EARLY EVENING SHOWERS AND THUNDERSTORMS MAINLY OVER NORTHERN AND EASTERN ARIZONA SUNDAY. A MUCH LARGER AND COLDER DISTURBANCE IS FORECAST TO MOVE INTO THE REGION MONDAY AND TUESDAY FOR A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS AREA-WIDE. CLEARING IS EXPECTED WEDNESDAY...HOWEVER ANOTHER LOW PRESSURE SYSTEM IS FORECAST TO MOVE INTO THE REGION LATER NEXT WEEK. && .DISCUSSION... VERY ISOLATED SHOWERS/TSTORMS CONTINUE TO MOVE THROUGH THE EAST VALLEY OF THE PHOENIX METRO AREA AS OF 0345Z THIS EVENING...AS THE LAST BIT OF THIS AFTERNOON`S BL INSTABILITY IS EXHAUSTED. NOT SURPRISINGLY...MOST OF THIS EVENING`S ACTIVITY WAS IN THE FORM OF BLOWING DUST/OUTFLOW WINDS...BUT A FEW SPOTS MANAGED TO SEE MEASURABLE PRECIP. AT THIS POINT THE FEW SHOWERS THAT REMAIN ARE ONLY PRODUCING SPRINKLES/VIRGA AND PATCHY BLOWING DUST...AND IT WOULD APPEAR THE ACTIVITY WILL CONTINUE TO TREND DOWNWARD THROUGH THE EVENING/OVERNIGHT HOURS. LAST FEW RUNS OF THE HRRR SUGGEST 100-250 J/KG OF ELEVATED INSTABILITY THROUGH 06Z...THEN RAPID STABILIZATION FOR THE DURATION OF THE OVERNIGHT HOURS. MADE A FEW FORECAST ADJUSTMENTS OVER THE PAST FEW HOURS TO CAPTURE WIND/DEWPOINT/SKY TRENDS. POPS STILL LOOK REASONABLE AND SINGLE DIGIT VALUES AFTER 06Z SEEM WARRANTED. NO ADDITIONAL CHANGES APPEAR NECESSARY AT THIS POINT. && .PREVIOUS DISCUSSION... SUNDAY THROUGH TUESDAY... A MAJOR CHANGE IN THE FLOW PATTERN/JET STREAM WILL TAKE PLACE SUNDAY THROUGH TUESDAY AS A NUMBER OF SMALL DISTURBANCES MOVE THROUGH THE REGION THIS EVENING AND SUNDAY AFTERNOON...FOLLOWED BY A MAJOR COOL TROF MONDAY AND TUESDAY. AS THE MULTITUDE OF SHORTWAVES CONTINUE TO MOVE INTO THE REGION FROM THE WEST...MODELS FORECAST A LONG SOUTHERLY FETCH OF 850 MB WINDS EMANATING FROM THE LOWER GULF OF CA. PRECIP WATER (PW) IMAGERY DETECTED THE HIGHEST VALUES OF PW IN THAT DIRECTION...SO AN INCREASINGLY MOIST BOUNDARY LAYER IS EXPECTED INTO SOUTHERN AZ THE NEXT 48 HOURS. SUNDAY. CONTINUED UPPER LEVEL CYCLONIC FLOW WITH A SECONDARY WEAK SHORTWAVE...COMBINED WITH A LITTLE MORE BOUNDARY LAYER MOISTURE AND ANOTHER WARM AFTERNOON...WILL CONTINUE A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS OVER THE MOUNTAINS OF SOUTH CENTRAL AZ FROM PHOENIX EAST AND SOUTHEAST. SKIES WILL BECOME PARTLY CLOUDY SUNDAY NIGHT. MONDAY AND TUESDAY...A MAJOR COOL PACIFIC TROF IS FORECAST TO MOVE INTO SOUTHERN CA EARLY MONDAY MORNING...THEN INTO AZ BY MONDAY AFTERNOON. THIS TROF IS MUCH COLDER AND UNSTABLE ALOFT...HAS STRONGER UPPER LEVEL DYNAMICS...AND WITH INCREASED BOUNDARY LAYER MOISTURE WILL LEAD TO A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS AREA-WIDE. SINCE IT WILL BE A SLOW EASTWARD MOVING TROF...THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO EARLY TUESDAY. WEDNESDAY...PARTLY CLOUDY WEDNESDAY WITH NO PRECIP AS A MINOR SHORTWAVE RIDGE MOVES QUICKLY THROUGH THE REGION. THURSDAY AND FRIDAY...ANOTHER COOL TROF IS FORECAST TO MOVE INTO THE REGION THE NORTHWEST. PRECIP CHANCES FOR NOW WILL BE CONFINED TO PARTS OF SOUTHEAST CA. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... SUSPENDED DUST/HAZE WILL CONTINUE TO MOVE THROUGH THE METRO THIS EVENING AND WHILE SURFACE VSBYS WILL REMAIN P6SM...SLANTWISE VSBYS WILL BE COMPROMISED THROUGH SUNDAY MORNING. EXPECTING LESS CONVECTION DURING THE DAY SUNDAY AND I WILL ONLY INCLUDE FEW/SCT MID CLOUDS SUNDAY AFTERNOON ALONG WITH TYPICAL DIURNAL WINDS. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... STILL EXPECTING LOW-IMPACT WEATHER EXPECTED ACROSS SOUTHEAST CALIFORNIA. WINDS WILL FOLLOW TYPICAL DIURNAL TRENDS THROUGH SUNDAY EVENING. ANY STORMS THAT DEVELOP ON SUNDAY WOULD LIKELY BE CONFINED TO AREAS WELL NORTH/EAST OF THE LOWER COLORADO RIVER. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... A COUPLE OF LATE-SEASON STORM SYSTEMS TO BRING COOLER TEMPS TO THE REGION DURING THE UPCOMING WEEK...WITH HIGHS REMAINING NEAR...OR SLIGHTLY BELOW NORMAL EACH DAY. THE 1ST STORM CENTER WILL ALSO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE REGION ON MONDAY AND TUESDAY...WITH THE BEST CHANCES FOR WETTING RAINS TO BE OVER THE HIGHER TERRAIN OF SOUTH-CENTRAL ARIZONA. THE 2ND STORM CENTER TO BRING AN INCREASE IN CLOUDINESS AND WINDS TO THE REGION ON WEDNESDAY AND THURSDAY. THE COMBINATION OF THESE STRONGER WINDS...AND AFTERNOON HUMIDITIES IN THE TEENS WILL DEFINITELY ALLOW FIRE DANGER LEVELS TO RISE DURING THIS PERIOD. OTHERWISE...AFTERNOON HUMIDITIES ARE EXPECTED TO FALL INTO THE 15-30 PERCENT RANGE ON MONDAY AND TUESDAY...AND AGAIN ON FRIDAY. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...LEINS/VASQUEZ AVIATION...LEINS FIRE WEATHER...PERCHA
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
413 PM MST SAT MAY 2 2015 .UPDATE...UPDATED AVIATION DISCUSSION... && .SYNOPSIS...A SERIES OF PACIFIC WEATHER DISTURBANCES IS FORECAST TO MOVE INTO THE REGION THROUGH TUESDAY...RESULTING IN A COOLING TREND. ENOUGH MOISTURE WILL BE PRESENT FOR A SLIGHT CHANCE OF AFTERNOON AND EARLY EVENING SHOWERS AND THUNDERSTORMS MAINLY OVER NORTHERN AND EASTERN ARIZONA SUNDAY. A MUCH LARGER AND COLDER DISTURBANCE IS FORECAST TO MOVE INTO THE REGION MONDAY AND TUESDAY FOR A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS AREA-WIDE. CLEARING IS EXPECTED WEDNESDAY...HOWEVER ANOTHER LOW PRESSURE SYSTEM IS FORECAST TO MOVE INTO THE REGION LATER NEXT WEEK. && .DISCUSSION... TONIGHT THROUGH TUESDAY...A MAJOR CHANGE IN THE FLOW PATTERN/JET STREAM WILL TAKE PLACE TODAY THROUGH TUESDAY AS A NUMBER OF SMALL DISTURBANCES MOVE THROUGH THE REGION THIS EVENING AND SUNDAY AFTERNOON...FOLLOWED BY A MAJOR COOL TROF MONDAY AND TUESDAY. THE DISTURBANCE WORKING ITS WAY INTO CENTRAL THIS AFTERNOON...BEST SEEN IN WATER VAPOR IMAGERY...ALONG WITH AN INCREASE IN BOUNDARY LAYER MOISTURE HAS LEAD TO SCATTERED THUNDERSTORMS MAINLY IN THE HIGH COUNTRY FROM PRESCOTT EAST TO THE WHITE MOUNTAINS AS 2 PM. THIS MORNINGS ANALYSIS SHOWED THERE WAS A SLIGHT THREAT OF AFTERNOON THUNDERSTORMS ACROSS PARTS OF THE SOUTH CENTRAL AZ DESERTS AND MOUNTAINS FROM PHOENIX EAST AND SOUTHEAST AS A FUNCTION OF THIS SHORTWAVE AND UPPER LEVEL CYCLONIC FLOW. SPECIAL EXPERIMENTAL HRRR SATELLITE DERIVED FUTURE PRECIP FORECASTS DID SHOW A TSTM THREAT JUST EAST AND SOUTHEAST OF PHOENIX FLOWING NORTH FROM SOUTHERN AZ FOR LATE TODAY. THEREFORE A SLIGHT CHANCE OF THUNDERSTORMS THROUGH EARLY EVENING WILL CONTINUE FOR AREAS EAST AND SOUTHEAST OF PHOENIX. CLEARING SKIES TONIGHT. INCREASING LOW LEVEL MOISTURE. AS THE MULTITUDE OF SHORTWAVES CONTINUE TO MOVE INTO THE REGION FROM THE WEST...MODELS FORECAST A LONG SOUTHERLY FETCH OF 850 MB WINDS EMANATING FROM THE LOWER GULF OF CA. PRECIP WATER (PW) IMAGERY DETECTED THE HIGHEST VALUES OF PW IN THAT DIRECTION...SO AN INCREASINGLY MOIST BOUNDARY LAYER IS EXPECTED INTO SOUTHERN AZ THE NEXT 48 HOURS. SUNDAY. CONTINUED UPPER LEVEL CYCLONIC FLOW WITH A SECONDARY WEAK SHORTWAVE...COMBINED WITH A LITTLE MORE BOUNDARY LAYER MOISTURE AND ANOTHER WARM AFTERNOON...WILL CONTINUE A SLIGHT CHANCE OF AFTERNOON THUNDERSTORMS OVER THE MOUNTAINS OF SOUTH CENTRAL AZ FROM PHOENIX EAST AND SOUTHEAST. SKIES WILL BECOME PARTLY CLOUDY SUNDAY NIGHT. MONDAY AND TUESDAY...A MAJOR COOL PACIFIC TROF IS FORECAST TO MOVE INTO SOUTHERN CA EARLY MONDAY MORNING...THEN INTO AZ BY MONDAY AFTERNOON. THIS TROF IS MUCH COLDER AND UNSTABLE ALOFT...HAS STRONGER UPPER LEVEL DYNAMICS...AND WITH INCREASED BOUNDARY LAYER MOISTURE WILL LEAD TO A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS AREA-WIDE. SINCE IT WILL BE A SLOW EASTWARD MOVING TROF...THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO EARLY TUESDAY. WEDNESDAY...PARTLY CLOUDY WEDNESDAY WITH NO PRECIP AS A MINOR SHORTWAVE RIDGE MOVES QUICKLY THROUGH THE REGION. THURSDAY AND FRIDAY...ANOTHER COOL TROF IS FORECAST TO MOVE INTO THE REGION THE NORTHWEST. PRECIP CHANCES FOR NOW WILL BE CONFINED TO PARTS OF SOUTHEAST CA. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... STORMS HAVE FORMED ACROSS THE AREA BUT THE BULK OF THE ACTIVITY HAS REMAINED TO THE SOUTH/EAST OF PHOENIX. LAST FEW RUNS OF THE HRRR AND OTHER HI-RES MODELS SUGGEST STORMS WILL DIMINISH BEFORE THEY REACH THE LOWER DESERTS AND I WILL KEEP ANY MENTION OF THUNDER OUT OF THE PHOENIX TERMINALS. WILL NEED TO KEEP AN EYE ON OUTFLOWS OUT OF THE SOUTH - ESPECIALLY AT KIWA ALTHOUGH CONFIDENCE IS LOW THAT THEY WOULD SURVIVE LONG ENOUGH TO BE OF MUCH IMPACT. KPHX/KSDL SHOULD SEE TYPICAL DIURNAL WINDS THIS EVENING THROUGH SUNDAY. SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... LOW-IMPACT WEATHER EXPECTED ACROSS SOUTHEAST CALIFORNIA. OUTSIDE OF SOME BREEZINESS AT KBLH THIS EVENING...WINDS WILL FOLLOW TYPICAL DIURNAL TRENDS. ANY STORMS THAT DEVELOP SHOULD REMAIN EAST OF THE COLORADO RIVER. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... TUESDAY THROUGH SATURDAY... A COUPLE OF LATE-SEASON STORM SYSTEMS TO BRING COOLER TEMPS TO THE REGION DURING THE UPCOMING WEEK...WITH HIGHS REMAINING NEAR...OR SLIGHTLY BELOW NORMAL EACH DAY. THE 1ST STORM CENTER WILL ALSO BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE REGION ON MONDAY AND TUESDAY...WITH THE BEST CHANCES FOR WETTING RAINS TO BE OVER THE HIGHER TERRAIN OF SOUTH-CENTRAL ARIZONA. THE 2ND STORM CENTER TO BRING AN INCREASE IN CLOUDINESS AND WINDS TO THE REGION ON WEDNESDAY AND THURSDAY. THE COMBINATION OF THESE STRONGER WINDS...AND AFTERNOON HUMIDITIES IN THE TEENS WILL DEFINITELY ALLOW FIRE DANGER LEVELS TO RISE DURING THIS PERIOD. OTHERWISE...AFTERNOON HUMIDITIES ARE EXPECTED TO FALL INTO THE 15-30 PERCENT RANGE ON MONDAY AND TUESDAY...AND AGAIN ON FRIDAY. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX DISCUSSION...VASQUEZ AVIATION...LEINS FIRE WEATHER...PERCHA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
259 PM MDT FRI MAY 1 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 257 PM MDT FRI MAY 1 2015 ...STORMS MOVING INTO EASTERN COLORADO THIS EVENING... ...WARM WEEKEND ON THE WAY... LATEST HRRR HAS A DECENT HANDLE ON THE CONVECTION...AND ALONG WITH OTHER HI-RES GUIDANCE SHOWS A WAVE OF CONVECTION INCREASING IN COVERAGE OVER THE I-25 CORRIDOR THIS AFTERNOON...THEN CLEARING I-25 BY 00-01Z THIS EVENING. STORMS WILL THEN CONSOLIDATE INTO AN MCS OVER THE ERN PLAINS THIS EVENING. THEN...SHOULD SEE SHOWERS AND STORMS MOVING INTO WRN KS BY 03Z OR SO THIS EVE. AFTER 06Z...PRECIP SHOULD BE OVER FOR MOST OF THE AREA...WITH JUST SOME LINGERING SHOWERS POSSIBLE OVER THE FAR ERN PLAINS AND HYR TRRN. UPPER RIDGE AND ASSOCIATED AVA SHOULD HELP SUPPRESS THINGS THROUGH SAT MORNING. TOMORROW...A WARMER DAY IS IN STORE...AS FLOW BECOMES A BIT MORE ZONAL AND H7 TEMPS RISE TO AROUND 10 DEG C. EXPECT 80 PLUS DEG TEMPS OVER MUCH OF THE PLAINS BY AFTERNOON...WITH 60S AND 70S FOR THE HIGHER ELEVATIONS. ANOTHER WEAK DISTURBANCE WILL SPARK SOME AFTERNOON STORMS MOVING OFF THE MTS SAT AFTERNOON...BUT WITH DEW POINTS IN THE 30S CONVECTION WILL NOT BE AS STRONG AS IT IS/WILL BE TODAY...AND COVERAGE A BIT LESS AS WELL. ROSE .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 257 PM MDT FRI MAY 1 2015 A RATHER WET PERIOD IS EXPECTED THE FIRST PART HALF OF NEXT WEEK. ON SUN AN UPR TROF WL MOVE TO ALONG THE CA COAST...WITH MSTR AHEAD OF THIS SYSTEM MOVING INTO THE FORECAST AREA...ALONG WITH A SHORTWAVE TROF IN THE AFTERNOON AND EVENING HOURS. IT STILL LOOKS LIKE A FRONT WL HANG UP ALONG THE PALMER DVD SUN AFTERNOON AND THEN WORK ITS WAY SOUTH IN THE EVENING HOURS. MUCH OF THE AREA WL SEE AT LEAST ISOLD TO SCT SHOWERS AND TSTMS SUN AND SUN EVENING. HIGH TEMPS ON SUN SHOULD STILL BE ABOVE AVERAGE BY ABOUT 5-10 DEG. ON MON THE UPR TROF MOVES INTO THE WRN STATES...WITH AN UPR LOW CENTER EXPECTED TO BE OVR SWRN AZ BY 00Z TUE. MSTR WL CONTINUE STREAMING INTO THE FORECAST AREA AHEAD OF THIS SYSTEM. OVR ERN PORTIONS OF THE FORECAST AREA...LOW TO MID LEVEL SERLY WINDS SHOULD HELP ENHANCE PCPN CHANCE ALONG AND ADJACENT TO THE ERN MTNS. WIDESPREAD PCPN IS EXPECTED ON MON ALONG WITH COOLER TEMPS. THE ECMWF AND GFS LIFT THE UPR LOW NORTHEASTWARD ON TUE. THE GFS IS A LITTLE FARTHER NORTH THAN THE GFS WITH THE LOW CENTER. THE GFS HAS IT IN NERN CO BY 00Z WED WITH THE ECMWF SHOWING IT OVR SERN CO. EITHER WAY...WIDESPREAD PCPN SHOULD CONTINUE THRU TUE. THIS SYSTEM WEAKENS AS IT MOVES NORTH-NORTHEASTWARD TUE NIGHT THROUGH WED...MOVING INTO THE WRN DAKOTAS BY 00Z THU. ALTHOUGH PCPN CHANCES ARE EXPECTED TO DECREASE SOME TUE NIGHT...THERE SHOULD STILL BE PLENTY OF MSTR AROUND FOR AN INCREASE IN ACTIVITY IN THE AFTERNOON AND EVENING HOURS ON WED AS THINGS REMAIN UNSETTLED. TEMPS REMAIN QUITE WARM AS THIS SYSTEM AFFECTS THE AREA AND SNOW ACCUMULATIONS ARE GENERALLY EXPECTED TO REMAIN OVR THE HYR MTN AREAS. SOME AREAS...ESPECIALLY NR THE ERN MTN...COULD SEE PERIODS OF HEAVY RAIN. ANOTHER UPR LOW IS THEN FORECAST TO MOVE INTO THE GREAT BASIN FOR LATE THU AND FRI. THIS WL KEEP THE WX UNSETTLED WITH PROBABLY FAIRLY WIDESPREAD PCPN CHANCES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING) ISSUED AT 257 PM MDT FRI MAY 1 2015 MAIN CONCERN WILL BE FROM NOW THROUGH ABOUT 02Z THIS EVENING...AS A BROKEN LINE OF STORMS MOVES EWD ACROSS THE I-25 CORRIDOR. COULD SEE SOME BRIEF IFR-MVFR IN STRONGER CELLS DURING THIS TIME...WITH BRIEF RA+ AND POSSIBLY SOME SMALL GR. STORMS WILL CONSOLIDATE OVER THE SERN CO PLAINS THIS EVENING BEFORE MOVING ON INTO WRN KS TONIGHT. THERE IS A SLIGHT CHANCE SOME PATCHY LOW CIGS OR BR COULD DEVELOP VC KCOS OR KPUB AFTER 03Z TONIGHT...DEPENDING ON THE EXTENT OF STORMS LATER THIS AFTERNOON AND EVENING. BUT ANY IMPACT SHOULD BE MINIMAL...WITH VFR CONDITIONS EXPECTED TO PERSIST THROUGH SATURDAY. STORMS SAT AFTERNOON SHOULD NOT BER AS WIDESPREAD OR STRONG AS THE STORMS TODAY. ROSE && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ROSE LONG TERM...28 AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1028 AM MDT FRI MAY 1 2015 .UPDATE... ISSUED AT 1028 AM MDT FRI MAY 1 2015 WILL BE UPDATING THE FORECAST TO INCREASE THE THUNDERSTORMS TO THE LIKELY CATEGORY ON THE PALMER DIVIDE AND EASTERN PLAINS DURING THE AFTERNOON AND EVENING. SATELLITE PICTURES SHOW THAT THE STRATUS ALONG THE FOOTHILLS IS THICKEST FROM THE NORTHWEST SIDE OF DENVER TO THE WYOMING BORDER. THIS IS LEAVING THE PALMER DIVIDE IN NEARLY FULL SUNSHINE. THE STRONGER HEATING OVER THE PALMER DIVIDE WILL CAUSE THE AIRMASS TO DE-STABILIZE THERE FIRST. THE LATEST RUNS OF THE HRRR AND RAP SHOW THE STRONGEST CONVECTION DEVELOPING OVER DOUGLAS COUNTY BY SHORTLY AFTER 18Z. THE MORNING SOUNDING SHOWED A PRECIPITABLE WATER OF .66 INCHES WHICH IS JUST SHORT OF THE RECORD FOR MAY 1. SHOULD SEE A GOOD ROUND OF SHOWERS DEVELOP EARLY IN THE AFTERNOON WHICH WILL DRIFT EASTWARD. THE OTHER MAIN AREA OF PRECIPITATION IS EXPECTED TO DEVELOP OVER THE CHEYENNE RIDGE AFTER ABOUT 21Z WHICH WILL MOVE OVER THE NORTHERN PLAINS ZONES THROUGH THE EVENING. WITH CAPE VALUES IN THE 1000-1500 J/KG RANGE THIS AFTERNOON...STORMS MAY GET STRONG ENOUGH TO PRODUCE SOME HAIL CLOSE TO 1 INCH IN DIAMETER. OTHERWISE...THEY WILL PRODUCE BRIEF HEAVY RAIN AND SOME GUSTY WINDS. MOST THUNDERSTORM ACTIVITY ALONG THE FRONT RANGE SHOULD BE DONE BY EARLY EVENING...WITH THE FOCUS OF CONVECTION THROUGH THE EVENING OUT ON THE NORTHEAST PLAINS. && .SHORT TERM...(TODAY THROUGH TONIGHT ) ISSUED AT 337 AM MDT FRI MAY 1 2015 MUCH OF THE SHOWERS HAVE DISSIPATED OVER THE NORTHEAST PLAINS WITH JUST A FEW LIGHT SHOWERS EXITING WASHINGTON AND PARK COUNTIES. STILL QUITE A BIT OF STRATUS AROUND AT VARIOUS LEVELS AND IS NOT WIDESPREAD OR UNIFORM. NO FOG BEING REPORTED YET BUT STILL EXPECT SOME PATCHY FOG STILL TO DEVELOP OVER LOW LYING AREAS AS SOME T/TD SPREADS ARE ONLY 2-5 DEGREES. COLORADO WILL BE UNDER A MODERATE WESTERLY FLOW ALOFT TODAY FOLLOWING LAST NIGHTS DISTURBANCE WITH STILL SOME UPSTREAM MOISTURE TO WORK WITH. MOST IMPRESSIVE IS THE INCREASE IN PW VALUES OVER THE PAST 24 HOURS...WITH INCREASES OVER .40" OVER THE FRONT RANGE WITH READINGS AROUND .75" FROM INTEGRATED PW FROM GPS. SHOULD SEE ANOTHER ROUND OF AFTERNOON/EVENING THUNDERSTORMS TODAY GIVEN AMPLE MOISTURE AS SURFACE DEWPOINTS SHOULD REMAIN IN THE 40S. THIS WILL RESULT IN SURFACE BASED CAPES FROM 800-1500J/KG. THERE IS SOME INITIAL STABILITY WITH LOW LEVEL INVERSIONS AROUND 750MB THIS AM WHICH MODELS EVENTUALLY ERODE BY LATE AFTERNOON. EXPECT HIGHER COVERAGE OF STORMS TODAY OVER FRONT RANGE FOOTHILLS AND PALMER DIVIDE AND LOWER COVERAGE OVER THE FAR PLAINS AS HIGHER STABILITY REMAINS. GIVEN CAPE VALUES AND THE INCREASE SHEAR ALOFT COULD BE A FEW SEVERE STORMS WITH HAIL UP TO ONE INCH IN DIAMETER AND DAMAGING WINDS. NOT MUCH HELP UPSTAIRS TODAY AS QG VERTICAL VELOCITY FIELDS INDICATE A NEUTRAL TO SLIGHTLY SUBSIDENT AIRMASS. STORMS SHOULD FOLLOW DIURNAL TRENDS WITH MOST STORMS ENDING BEFORE MIDNIGHT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 337 AM MDT FRI MAY 1 2015 EXPECT THE UPPER RIDGE TO REMAIN ALOFT ON SATURDAY. AT THE SURFACE...A TROUGH DIGGING ALONG THE EASTERN CO PLAINS WILL HELP MIX OUT THE POST FRONTAL STABLE AIRMASS FOR MUCH WARMER TEMPERATURES. SHOWERS AND STORMS ARE NOT EXPECTED TO FORM UNTIL THE AFTERNOON WITH SOME DECENT CAPE OVER THE FAR EASTERN PLAINS. COULD SEE SOME STRONGER STORMS IN THE LATE AFTERNOON AND EARLY EVENING OUT THAT WAY. ANOTHER COLD FRONT IS PROGGED TO PUSH DOWN THE PLAINS SUNDAY COMBINED WITH MOISTURE ADVECTING UP FROM NEAR BAJA. LOOK FOR COOLER TEMPERATURES AND AN INCREASE IN SHOWER AND STORM COVERAGE. AN UPPER LOW WILL DIG DOWN OVER SRN CALIFORNIA/BAJA SUNDAY NIGHT. THIS UPPER LOW WILL PUSH EAST EARLY MONDAY THEN GET PICKED UP AND BROUGHT NORTHEAST OVER THE STATE AS A LARGER LOW OVER THE PACIFIC NORTHWEST MOVES ONSHORE TUESDAY. UPSLOPE FLOW FROM SUNDAY NIGHT IS EXPECTED TO CONTINUE THROUGH TUESDAY AFTERNOON AS THE UPPER LOW APPROACHES. THIS WILL BRING A VERY GOOD CHANCE FOR RAIN SHOWERS AND THUNDERSTORMS TO THE AREA MONDAY THROUGH TUESDAY AFTERNOON. HAVE PUT POPS IN THE HIGH CHANCE CATEGORY...WITH THE FAR EASTERN PLAINS SEEING LIKELY POPS ON TUESDAY AFTERNOON. THEN AS THE UPPER LOW PUSHES NORTHEAST OF THE AREA AND A SURFACE LOW FORMS OVER THE EASTERN COLORADO PLAINS...CHANCES WILL START DECREASING FROM THE SOUTH BUT WILL STILL SEE SHOWERS AROUND THROUGH WEDNESDAY. SYSTEM WILL BE QUITE WARM WITH SNOW LEVELS REMAINING AROUND 10KFT. PAST WEDNESDAY REMAINS AN UNCLEAR FORECAST...AS MODELS CONTINUE TO STRUGGLE WITH THE EVOLUTION AND TRACK OF THE PACNW UPPER LOW. MODELS HAD BEEN SEEMING TO TAKE A MORE SOUTHERLY TRACK...UNTIL THE 00Z EC CAME IN PUSHING IT BACK FARTHER NOR TH. HOWEVER...EITHER WAY...MOISTURE WILL CONTINUE TO BE PRESENT WEDNEDAY INTO THURSDAY...THE MODEL DIFFERENCES WILL MAINLY AFFECT TEMPERATURES. && .AVIATION...(FOR THE TAFS THROUGH 18Z SATURDAY MORNING) ISSUED AT 1028 AM MDT FRI MAY 1 2015 WILL MENTION THE BEST TIME FOR THUNDERSTORMS ACROSS THE DENVER AREA AIRPORTS FROM 3 PM THROUGH ABOUT 7 PM. OVERNIGHT...THINGS SHOULD CLEAR OUT NICELY WITH DECENT DRAINAGE WINDS WHICH SHOULD KEEP FOG OR STRATUS FROM DEVELOPING. NO OTHER AVIATION IMPACTS ARE EXPECTED AFTER THE ROUND OF AFTERNOON THUNDERSTORMS. && .BOU WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...DANKERS SHORT TERM...ENTREKIN LONG TERM...KRIEDERMAN AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
748 PM EDT SAT MAY 2 2015 .SYNOPSIS... HIGH PRESSURE BUILDS EASTWARD TO THE MID ATLANTIC COAST THROUGH SUNDAY...WHILE A WEAK TROUGH WILL DEVELOP OVER THE INTERIOR SUNDAY AFTERNOON. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES MONDAY NIGHT...GRADUALLY PASS TO THE SOUTH TUESDAY INTO TUESDAY NIGHT...THEN DISSIPATE ON WEDNESDAY. HIGH PRESSURE WILL THEN BUILD DOWN FROM CANADA THURSDAY THROUGH THURSDAY NIGHT. A BACK DOOR COLD FRONT MAY PUSH THROUGH ON FRIDAY AS THE HIGH RETREATS TO THE NORTHEAST. ANOTHER FRONTAL SYSTEM WILL APPROACH NEXT WEEKEND. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... SHOWER POTENTIAL WITH SEABREEZE BOUNDARY...NOW IN ORANGE COUNTY...WILL QUICKLY COME TO AND END OVER THE NEXT HOUR OR SO WITH LOSS OF DAYTIME HEATING AND IN WAKE OF SHORTWAVE. CLOUDS GRADUALLY DISSIPATE AS WELL...LEAVING MOSTLY CLEAR SKIES OVERNIGHT. HRRR AND NARRE KEEPING STRATUS OF NEW ENGLAND COAST...DRIFTING NORTH TOWARDS MAINE OVERNIGHT. LOWS WILL FALL TO THE LOWER 50S IN THE NYC URBAN HEAT ISLAND...INTO THE 40S MOST ELSEWHERE...AND THE MID/UPPER 30S IN THE LONG ISLAND PINE BARRENS AND POSSIBLE IN ISOLD SPOTS ACROSS THE INTERIOR VALLEYS. SOME PATCHY FROST IN THOSE COLDER SPOTS. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... HEIGHTS ALOFT WILL CONTINUE TO RISE ON SUNDAY. AS SURFACE HIGH PRESSURE BUILDS TO THE MID ATLANTIC COAST...REDEVELOPMENT OF THERMAL TROUGH WILL TAKE PLACE FARTHER INLAND. EXPECT WARMER TEMPS ON SUNDAY...WITH HIGHS IN THE MID/UPPER 70S FROM NYC NORTH/WEST...BUT COASTAL SECTIONS IN SEA BREEZE REGIME SHOULD ONLY REACH THE MID AND UPPER 60S...WITH TEMPS FALLING DURING MID TO LATE AFTERNOON AFTER REACHING THEIR PEAK AT OR JUST AFTER MIDDAY. LOWS SUNDAY NIGHT SHOULD ALSO BE NOT AS COOL...WITH 50S ACROSS MOST OF THE AREA...AND 40S CONFINED TO ERN LONG ISLAND...MOST OF SRN CT AND THE VALLEYS WELL NORTH/WEST OF NYC. BACKED OFF ON ISOLD SHOWER DEVELOPMENT SUNDAY AFTERNOON TO THE FAR NRN TIER OF ZONES...AS THE THERMAL TROUGH WILL BE WEAKER AND FARTHER INLAND...AND AIR MASS WILL BE A LITTLE DRIER. && .LONG TERM /MONDAY THROUGH SATURDAY/... UPPER RIDGING TO START THE WEEK WILL TRANSITION TO A SPLIT FLOW REGIME WITH THE REGION IN BETWEEN A DEEP UPPER LOW OVER EASTERN CANADA AND A DEVELOPING CLOSED LOW OFF THE SE US COAST FOR THE MID TO LATE WEEK. UNSEASONABLY WARM TEMPS EXPECTED ON MONDAY AND POSSIBLY TUESDAY WITH SW FLOW AROUND HIGH PRESSURE TO THE SOUTH OF THE REGION. TEMPS ON MONDAY LIKELY INTO THE LOWER 80S NYC/NJ METRO AND INTERIOR AND MID 70S TO THE COAST. A COLD FRONT PRESSES ON THE REGION TUESDAY AS SHORTWAVE ENERGY SWINGS THROUGH ONTARIO/QUEBEC. INCREASING CLOUDS AND AFTERNOON SCATTERED SHRA/TSTM ACTIVITY SHOULD KEEP TEMPS A BIT COOLER ON TUESDAY...PARTICULARLY ACROSS CT/LOWER HUD. BUT HIGHS FARTHER SOUTH COULD STILL TOP OUT IN THE MID 70S FOR COAST AND AROUND 80 NYC/NJ METRO. ALTHOUGH FORCING IS NOT STRONG...MODELS ARE INDICATING SOME CONVECTIVELY INDUCED VORTS RUNNING THROUGH THE ZONAL FLOW ALOFT...AND WITH MOISTURE CONVERGENCE AND AT LEAST MARGINAL INSTABILITY TO WORK WITH AHEAD OF THE SLOW MOVING COLD FRONT...CHANCE POPS FOR SHRA/TSRA ARE WARRANTED. INSTABILITY/WIND/SHEAR FIELDS ARE NOT INDICATIVE OF ORGANIZED SEVERE WEATHER. WITH THE FRONT PARALLELING THE UPPER FLOW TUE INTO TUE NIGHT...THE FRONT WILL BE SLOW TO MOVE SOUTH...KEEPING A CHANCE FOR SHRA TUE NIGHT. WITH TROUGHING DEEPENING INTO NEW ENGLAND WEDNESDAY THE WEAKENING COLD FRONT SHOULD CONTINUE TO SINK SOUTH WITH GRADUAL DRYING. CANADIAN HIGH PRESSURE GRADUALLY BUILDS INTO THE REGION WED NIGHT INTO THU NIGHT AS THE UPPER LOW MAINTAIN CONTROL OVER THE CANADIAN MARITIMES. WITH A CONTINENTAL AIR MASS WED AND THU...TEMPS SHOULD STILL RUN ABOVE SEASONABLE. MODELS SIGNALING SOME POTENTIAL FOR A BACKDOOR COLD FRONT FRI...WHICH IS PLAUSIBLE BASED ON LOCATION OF CLOSED LOW TO THE NE...WHICH WOULD RESULT IN TEMPS FALLING TO BELOW SEASONABLE LEVELS ALONG THE COAST ON FRI AND POSSIBLY SAT. OTHERWISE...MODELS INDICATING POTENTIAL FOR RIDGING TO WORK BACK INTO THE REGION FOR THE WEEKEND AS THE CANADIAN LOW SLIDES OFFSHORE. THIS WOULD SPELL AN INCREASINGLY WARM AND MOIST AIR MASS FOR THE WEEKEND AHEAD OF THE NEXT APPROACHING FRONTAL SYSTEM. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... A WEAK...BROAD TROUGH OF LOW PRESSURE OVER THE AREA WILL WEAKEN TONIGHT AS HIGH PRESSURE BUILDS TOWARD THE MID ATLANTIC COAST. VFR THRU THE TAF PERIOD. LGT AND VRB WINDS TNGT. DIRECTION BECOMES S ON SUN WITH SEA BREEZE ENHANCEMENT AT THE COASTS. EXCEPTION WILL BE KSWF WHERE THERE WILL BE W FLOW AT TIMES WITH A SFC TROF DEVELOPING ALONG THE HUDSON VALLEY. .OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY... .SUNDAY NIGHT-MON NIGHT...VFR. SW WINDS G15-20KT POSSIBLE MON AFTERNOON. .TUE-TUE NIGHT...MVFR OR LOWER CONDS POSSIBLE WITH ANY SHOWERS/TSTMS. .WED...LOW CHANCE OF MVFR OR LOWER CONDS IN ANY SHOWERS...OTHERWISE VFR. .THU...VFR. && .MARINE... OCEAN SWELLS CONTINUE CLOSE TO 5 FT...WITH RELATIVELY SHORT PD...SO HAVE CONTINUED SCA FOR HAZARDOUS SEAS W OF MORICHES INLET FOR TONIGHT. UPWARD TREND HAS NOT BEEN NOTED AT 44017 WITH SEA REMAINING JUST SHY OF 4 FT...SO HAVE NOT INCLUDED WATERS FARTHER E YET. THE NEXT CHANCE FOR SCA CONDITIONS WILL BE LATE MON INTO MON NIGHT AHEAD OF AN APPROACHING COLD FRONT...WITH WIND GUSTS TO 25 KT AND OCEAN SEAS BUILDING TO NEAR 5 FT. SEAS UP TO 5 FT COULD LINGER OVER THE OCEAN WATERS E OF MORICHES INLET ON TUE. && .HYDROLOGY... LOCALLY HEAVY RAINFALL AMOUNTS ARE POSSIBLE TUE AFTERNOON/EVENING WITH SCATTERED CONVECTION AHEAD OF A COLD FRONT. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT SUNDAY FOR ANZ353-355. && $$ SYNOPSIS...GOODMAN/NV NEAR TERM...GOODMAN/NV SHORT TERM...GOODMAN LONG TERM...NV AVIATION...BC/JMC MARINE...GOODMAN/NV HYDROLOGY...NV
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NWS MELBOURNE FL
924 AM EDT FRI MAY 1 2015 .DISCUSSION... RELATIVELY DRY NW FLOW WILL SLOWLY DIMINISH IN SPEED WHILE VEERING MORE NLY LATER TODAY. AN ONSHORE WIND IN THE FORM OF AN AFTERNOON SEABREEZE WL WORK INLAND THROUGH MID AFTERNOON. UNDER MOSTLY SUNNY SKIES TEMPS WILL RISE INTO TEH LWR 80S INLAND AND AROUND 80 ALONG THE COAST. THE CURRENT FORECAST IS IN GOOD SHAPE. && .AVIATION...VFR. && .MARINE... TODAY-TONIGHT...NORTHWEST WINDS WILL RESULT IN RATHER BENIGN CONDITIONS FOR SMALL CRAFT OPERATORS NEAR THE COAST THIS MORNING. A SEA BREEZE ALONG THE IMMEDIATE CST WILL VEER WINDS TO NE AT EARLY TO MID AFTERNOON. A NORTHERLY SURGE TO 15 KNOTS IS INDICATED LATE IN THE AFTERNOON IN THE NORTH AND SHIFTING TO THE SOUTHERN WATERS AFTER MIDNIGHT. A CAUTION STATEMENT MAY BE NECESSARY LATE TODAY / TONIGHT IN THE GULF STREAM IF THE SURGE TURNS OUT TO BE SLIGHTLY STRONGER AS IS INDICATED BY LTST HRRR GUID. && .FIRE WEATHER...COT`S ADVECTION SWD OF DRIER AIR WILL CAUSE MIN RH VALUES TO FALL SLIGHTLY BELOW 35 PERCENT ALONG/NORTHWEST OF I-4. WINDS ARE FORECAST TO REMAIN BELOW 15 MPH. && .CLIMATE... APRIL WAS THE RECORD WARMEST AT DAB/MLB/VRB. IT WAS THE SECOND WARMEST APRIL AT MCO. EVERY DAY WAS WARMER THAN NORMAL AT THESE SITES IN APRIL...EXCEPT ON THE 30TH DAB WAS A FEW DEGREES BELOW THAN NORMAL WHILE MCO AND MLB WERE RIGHT AT NORMAL. STATION AVERAGE TEMP RECORD DAB 75.3 74.4 IN 1947 MCO 77.6 78.7 IN 1908 MLB 77.1 75.1 IN 1947 VRB 76.9 75.4 IN 1945 & 1947 APRIL WAS WETTER THAN NORMAL: DAB WAS THE 7TH WETTEST ON RECORD AND VRB WAS THE 10TH WETTEST ON RECORD. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. && $$ JP/ALM
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
238 AM EDT FRI MAY 1 2015 .SYNOPSIS... LOW PRESSURE JUST OFF THE NORTH CAROLINA COAST TODAY WILL BE FARTHER OFFSHORE SATURDAY AND SUNDAY. A PRESSURE RIDGE IN THE MISSISSIPPI RIVER VALLEY TODAY WILL SHIFT EASTWARD. THE RIDGE WILL EXTEND ALONG THE EAST COAST SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... SOME WRAP-AROUND MOISTURE ASSOCIATED WITH LOW PRESSURE JUST OFF THE NORTH CAROLINA COAST WILL AFFECT MAINLY THE NORTHEAST PART OF THE FORECAST AREA TODAY. INSTABILITY ASSOCIATED WITH THE UPPER LOW OVER NORTH CAROLINA WILL BE GREATER IN THE NORTH PART OF THE FORECAST AREA. THE MODELS INDICATE LIFT ASSOCIATED WITH A SHORTWAVE TROUGH ROTATING AROUND THE UPPER LOW WILL HAVE MOVED OUT OF THE FORECAST AREA THIS AFTERNOON. THE PATTERN SUPPORTS A CHANCE OF SHOWERS MAINLY IN THE NORTHEAST SECTION EARLY TODAY. THE LOW GUIDANCE POPS APPEAR REASONABLE BECAUSE OF CONTINUED SHALLOW MOISTURE. THE HIGH-RESOLUTION MODELS DISPLAY WIDELY SCATTERED COVERAGE IN THE NORTH PART. THUNDERSTORMS COULD POSSIBLY OCCUR IN THE NORTH PART CLOSER TO THE COLDER TEMPERATURES ALOFT. LOW WET-BULB ZERO HEIGHTS FAVOR HAIL...BUT ANY HAIL SHOULD BE SMALL BECAUSE OF WEAK INSTABILITY. USED THE COOLER HIGH TEMPERATURE GUIDANCE BECAUSE OF THE COLD TEMPERATURES ALOFT. ANY SHOWERS SHOULD DISSIPATE TONIGHT WITH THE LOSS OF HEATING. THE MODELS DISPLAY MOISTURE FURTHER DIMINISHING AS THE AREA OF LOW PRESSURE OFF THE NORTH CAROLINA COAST SHIFTS A LITTLE FARTHER EASTWARD. IT WILL BE A COOL NIGHT. THE GUIDANCE WAS CLOSE WITH LOWS AROUND 50. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... THE PRESSURE RIDGE APPROACHING FROM THE WEST SHOULD EXTEND THROUGH THE AREA SUNDAY. EXPECT DRY WEATHER. THE TEMPERATURE GUIDANCE WAS CONSISTENT. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE MODELS HAVE BEEN CONSISTENT WITH RIDGING DOMINATING THROUGH THE MEDIUM-RANGE PERIOD. THE GFS...ECMWF...AND EKD MOS HAVE POPS LESS THAN 20 PERCENT THROUGH THE PERIOD. THE MOS HAS LOW TEMPERATURES IN THE 50S WITH HIGHS IN THE LOWER AND MIDDLE 80S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WEAK SURFACE LOW ALONG THE CAROLINA COAST. UPPER LOW SINKING SOUTHEAST ACROSS NORTH CAROLINA. WIDELY SCATTERED SHOWERS ASSOCIATED WITH UPPER LOW MOVING SOUTHEAST FROM THE UPSTATE INTO PORTIONS OF THE NORTHERN AND CENTRAL MIDLANDS. LATEST HRRR GUIDANCE AND RADAR TRENDS SUGGEST SOME SHOWERS MAY MOVE NEAR THE TERMINALS IN THE 06Z-08Z TIME FRAME. PRECIPITATION WILL BE LIGHT AND VSBYS WILL REMAIN VFR. GIVEN LATEST RADAR TRENDS...WILL MENTION -RA AT CAE/CUB UNTIL 08Z. WINDS LIGHT AND MAINLY SOUTHWEST TO NORTHWEST DURING THE PRE-DAWN HOURS. DRIER AIR IN PLACE AND BOUNDARY LAYER MIXING SHOULD PREVENT FOG DEVELOPMENT BEFORE SUNRISE. SCATTERED TO BROKEN STRATO-CU EXPECTED LATER TODAY WITH GUSTY NORTHWEST TO NORTH WINDS AS SURFACE LOW ALONG THE CAROLINA COAST MOVES TO THE NORTHEAST. WINDS WILL DIMINISH THIS EVENING. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH HIGH PRESSURE OVER THE REGION. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
134 AM EDT FRI MAY 1 2015 .SYNOPSIS... LOW PRESSURE OFF THE CAROLINA COAST WILL TRACK TO THE NORTHEAST AWAY FROM THE AREA FOR THE WEEKEND. AN UPPER-LEVEL LOW WILL REMAIN IN THE REGION THROUGH FRIDAY. THIS FEATURE WILL GENERATE WIDELY SCATTERED MAINLY AFTERNOON SHOWERS. HIGH PRESSURE WILL BUILD INTO THE REGION THROUGH THE WEEKEND INTO NEXT WEEK WITH DRY AND SEASONABLE CONDITIONS. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... SURFACE LOW PRESSURE OFF THE NC COAST WILL LIFT NORTHEAST OVERNIGHT AS HIGH PRESSURE OVER THE CENTRAL CONUS BUILDS INTO THE REGION. AN UPPER LEVEL LOW OVER THE OHIO RIVER VALLEY WILL MOVE SOUTHWARD INTO NC BY SUNRISE FRIDAY. COLD AIR ALOFT ASSOCIATED WITH THE UPPER LOW AND A SHORT WAVE ROTATING AROUND THE UPPER LOW WILL BRING CLOUDS AND SCATTERED TO ISOLATED SHOWERS TO THE MIDLANDS AND UPPER SAVANNAH RIVER AREA OVERNIGHT. THUS...HAVE INCREASED POPS FOR THE OVERNIGHT ALTHOUGH RAINFALL AMOUNTS WILL BE LIGHT. OVERNIGHT LOWS ARE EXPECTED TO FALL INTO THE UPPER 40S AND LOWER 50S. && .SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY/... SLIGHT CHANCE OF SHOWERS IN THE NORTHERN MIDLANDS/PEE DEE REGIONS THROUGH FRIDAY MORNING AS A STRONG S/W MOVES SE THROUGH THE AREA. MODELS HAVE THE S/WV CLEARING THE AREA FRIDAY AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND WITH MOSTLY CLEAR SKIES AND BELOW NORMAL TEMPS. HIGHS WILL BE IN THE LOWER 70S FRIDAY AND MID TO UPPER 70S SATURDAY. OVERNIGHT LOWS WILL BE IN THE UPPER 40S TO LOWER 50S FRIDAY NIGHT AND IN THE 50S SATURDAY NIGHT. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... MODELS HAVE BEEN CONSISTENT SHOWING AN UPPER LEVEL RIDGE MOVING OVER THE REGION AT THE BEGINNING OF NEXT WEEK. SURFACE HIGH PRESSURE IS EXPECTED TO DOMINATE FROM MONDAY THROUGH THURSDAY. POPS NEXT WEEK ARE EXPECTED TO BE LESS THAN 20 PERCENT. TEMPERATURES ARE LIKELY TO BE NEAR NORMAL WITH HIGHS IN THE LOW TO MID 80S. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WEAK SURFACE LOW ALONG THE CAROLINA COAST. UPPER LOW SINKING SOUTHEAST ACROSS NORTH CAROLINA. WIDELY SCATTERED SHOWERS ASSOCIATED WITH UPPER LOW MOVING SOUTHEAST FROM THE UPSTATE INTO PORTIONS OF THE NORTHERN AND CENTRAL MIDLANDS. LATEST HRRR GUIDANCE AND RADAR TRENDS SUGGEST SOME SHOWERS MAY MOVE NEAR THE TERMINALS IN THE 06Z-08Z TIME FRAME. PRECIPITATION WILL BE LIGHT AND VSBYS WILL REMAIN VFR...BUT CONFIDENCE IS LOW WHETHER TO MENTION IN THE TAFS SO WILL LEAVE OUT FOR NOW. WINDS LIGHT AND MAINLY SOUTHWEST TO NORTHWEST DURING THE PRE-DAWN HOURS. DRIER AIR IN PLACE AND BOUNDARY LAYER MIXING SHOULD PREVENT FOG DEVELOPMENT BEFORE SUNRISE. SCATTERED TO BROKEN STRATO-CU EXPECTED LATER TODAY WITH GUSTY NORTHWEST TO NORTH WINDS AS SURFACE LOW ALONG THE CAROLINA COAST MOVES TO THE NORTHEAST. WINDS WILL DIMINISH THIS EVENING. EXTENDED AVIATION OUTLOOK...VFR CONDITIONS EXPECTED THROUGH THE PERIOD WITH HIGH PRESSURE OVER THE REGION. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...NONE. GA...NONE. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
857 PM CDT SAT MAY 2 2015 .UPDATE... ISSUED AT 857 PM CDT SAT MAY 2 2015 ISOLATED TO SCATTERED SHOWERS ARE MOVING INTO THE AREA FROM THE WEST AND IT APPEARS THEY WILL CONTINUE TO MOVE EAST THROUGH THE NIGHT. MODELS CONTINUE TO SHOW THIS AREA WEAKENING AS IT MOVES EAST, AND IR SATELLITE LOOP SEEMS TO SUPPORT THIS WITH CLOUD TOPS WARMING ACROSS THE WHOLE AREA OF WHERE THE SHOWERS ARE. ITS ALSO MOVING AWAY INTO A DRIER AIRMASS. HAVE TRIED TO MAKE SOME ADJUSTMENTS TO POPS FOR REMAINDER OF THE NIGHT IN THE GRIDS. OTHER PARAMETERS SHOULD BE OK OR RELATIVELY CLOSE TO CURRENT AND EXPECTED CONDITIONS REMAINDER OF THE NIGHT. OTHER SHOWERS AND THUNDERSTORMS HAVE BEEN DEVELOPING FURTHER WEST IN THE PLAINS. HRRR MODEL SHOWS THESE MAKING THEIR WAY INT WESTERN AND NORTHWESTERN IL TOMORROW MORNING. WILL BE TAKING A CLOSER LOOK AT THIS OVER THE NEXT SEVERAL HOURS. ANOTHER UPDATE MAY BE NEEDED LATER THIS EVENING BEFORE NEW FORECAST PACKAGE COMES OUT AT 4AM. UPDATE TO FORECAST WILL BE COMING SHORTLY. && .SHORT TERM...(TONIGHT) ISSUED AT 255 PM CDT SAT MAY 2 2015 A WEAK SHORT WAVE OVER WESTERN IA WILL TRACK EAST TO THE IL/IA BORDER BY MIDNIGHT AND WEAKEN AS IT MOVES ACROSS CENTRAL AND NORTHERN IL OVERNIGHT. AN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS OVER NORTHERN MO AND SOUTHERN IA WILL CONTINUE TO TRACK EASTWARD INTO WEST CENTRAL IL EARLY THIS EVENING BETWEEN 6-8 PM AND INTO CENTRAL IL LATER THIS EVENING AND OVERNIGHT AS SHOWERS BECOME MORE ISOLATED. HAVE 20-30% CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS FROM I-55 NW AFTER SUNSET TONIGHT AND LINGERING ISOLATED LIGHT SHOWERS UNTIL MID SUNDAY MORNING NORTH OF I-72 UNTIL WEAKENING SHORT WAVE PASSES EAST OF IL INTO WESTERN IN BY MIDDAY SUNDAY. MID AND HIGH CLOUDS WILL CONTINUE TO INCREASE FROM THE WEST LATE THIS AFTERNOON AND EVENING WITH SOUTHEAST IL SEEING LESS CLOUD COVER TONIGHT SINCE CLOSER TO HIGH PRESSURE RIDGE OVER SOUTHEAST STATES. LOWS TONIGHT IN THE LOW TO MID 50S WITH COOLEST READINGS NEAR WABASH RIVER WHERE LIGHTER WINDS AND LESS CLOUD COVER TONIGHT. SSW WINDS 7- 14 MPH AND GUSTS 15-20 MPH THIS AFTERNOON TO DIMINISH LESS THAN 10 MPH AFTER SUNSET AND VEER SSE. .LONG TERM...(SUNDAY THROUGH SATURDAY) ISSUED AT 255 PM CDT SAT MAY 2 2015 IOWA SHORTWAVE FORECAST BY MODELS TO TRACK ACROSS THE AREA OVERNIGHT AND INTO THE MORNING HOURS OF SUNDAY BRINGING ISOLATED SHOWERS TO PARTS OF THE FORECAST AREA. SOUNDINGS STILL SHOWING A VERY DRY PROFILE BELOW 725 MB (~8500 FEET) INTO SUNDAY MORNING BEFORE THE WAVE SHIFTS OFF TO OUR EAST DURING THE MORNING. WILL KEEP SLIGHTS GOING FOR A FEW HOURS IN THE MORNING BEFORE THE WAVE MOVES OUT OF THE AREA. OUR ATTENTION THEN TURNS TO A NORTHERN STREAM SHORTWAVE THAT WILL DRAG A COLD FRONT SOUTHEAST INTO THE LOWER GREAT LAKES LATE SUNDAY AND INTO MONDAY INCREASING THE CHANCES FOR MORE WIDESPREAD SHOWERS AND STORMS...ESPECIALLY OVER THE NORTHERN HALF OF THE FORECAST AREA WHERE THE BOUNDARY IS FORECAST TO BECOME STATIONARY. AFTER OUR SLIGHT CHANCES SUNDAY MORNING...THE REST OF THE DAY LOOKS QUIET AND WARM WITH A GUSTY SOUTH TO SOUTHWEST WIND HELPING TO PUSH AFTERNOON TEMPS INTO THE UPPER 70S TO LOWER 80S. POPS START TO RAMP UP SUNDAY NIGHT ACROSS THE FAR NORTHWEST AS THE BOUNDARY EDGES SLOWLY SOUTHEAST WITH MODELS TRENDING SLOWER WITH THE FRONTAL BOUNDARY AND QPF ALONG IT. MAY HAVE TO SLOW THE ONSET OF THE SHOWERS EVEN MORE IF THESE TRENDS CONTINUE. BETTER LOW LEVEL JET SUPPORT AND 850 MB THETA-E ADVECTION REMAINS OUT TO OUR NORTHWEST LATE SUNDAY NIGHT WITH MOST MODELS SUGGESTING THAT A CLUSTER OF STORMS...AT LEAST WHAT`S LEFT OF THEM...WILL APPROACH OUR FAR NORTHWEST COUNTIES WELL AFTER MIDNIGHT SUNDAY NIGHT. THE SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE TO SPREAD SLOWLY SOUTHEAST ON MONDAY AND INTO MONDAY NIGHT WITH THE HIGHER THREAT BEING AGAIN WHERE THE BOUNDARY IS EXPECTED TO BECOME STATIONARY... WHICH AT THIS TIME LOOKS TO BE NORTH OF I-72. FORECAST SOUNDINGS SHOWING MIXED LAYER CAPES OF AROUND 1500 J/KG MONDAY AFTERNOON INTO EARLY MONDAY EVENING WITH THE STRONGER 500 MB WIND FLOW TO OUR NORTH WITH 30-35 KTS FORECAST. SPC HAS A LARGE AREA OF MARGINAL RISK FOR SEVERE STORMS MONDAY AFTERNOON AND EVENING STRETCHING FROM THE SOUTHERN PLAINS UP ACROSS THE NORTHERN HALF OF OUR CWA. SEVERE PARAMETERS BORDERLINE AT THIS TIME BUT WITH THE BOUNDARY IN THE AREA AND FORECAST CONVECTIVE TEMPS AROUND 80...MULTI-CELL STORMS SHOULD DEVELOP DURING THE AFTERNOON AND CONTINUE INTO THE EVENING WITH THE POSSIBILITY FOR SOME GUSTY WINDS...HAIL AND HEAVY RAINFALL WITH SOME OF THE MORE ORGANIZED CLUSTERS OF STORMS THAT FORM ALONG THE STALLED FRONTAL BOUNDARY. MODELS SUGGEST THE BOUNDARY WILL SHIFT NORTH OF THE AREA STARTING ON TUESDAY AS UPPER LEVEL HEIGHTS BUILD IN RESPONSE TO A RATHER VIGOROUS UPPER WAVE THAT WILL BE PUSHING ACROSS THE SOUTHERN ROCKIES AND EVENTUALLY SWING NORTHEAST INTO THE PLAINS BY MID TO LATE IN THE UPCOMING WORK WEEK. WILL INDICATE A BIT OF A LULL IN THE SHOWER AND STORM CHANCES UNTIL LATE THURSDAY OR FRIDAY WHEN THE WAVE WILL APPROACH OUR AREA. TEMPERATURES LOOK TO BE ABOVE NORMAL THRU THE WORK WEEK WITH AFTERNOON HIGHS CLIMBING INTO THE UPPER 70S TO LOWER 80S...WHILE EARLY MORNING LOWS ONLY DROP OFF INTO THE UPPER 50S TO LOWER 60S TUESDAY MORNING...WITH MOST OF OUR AREA SEEING LOW TEMPERATURES IN THE LOW TO MID 60S FOR THE REMAINDER OF THE WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 614 PM CDT SAT MAY 2 2015 HIGH CLOUDS HAVE OVERSPREAD THE TAF SITES THIS EVENING AND AM EXPECTING MID CLOUDS TO ADVECT INTO THE AREA AS A WEAK WAVE MOVES INTO THE AREA FROM THE WEST. SHOWERS IS ASSOCIATED WITH THIS WAVE IN NORTHEASTERN MO AND WEST CENTRAL ILLINOIS. HRRR AND OTHER SHORT TERM MODELS SHOW THESE LIGHT SHOWERS DISSIPATING AS THEY MOVE EAST INTO DRIER AIRMASS OVER ILLINOIS. SO WILL BRING IN LOWER CLOUDS AROUND 8KFT THIS EVENING WITH VCSH. HRRR INDICATES THE SCATTERED SHOWERS COULD LAST UNTIL MORNING, SO WILL KEEP VCSH UNTIL THEN. THEN SKY COVER BECOMES SCATTERED MID CLOUDS OR CLEAR FOR TOMORROW. SOUTHWEST WINDS WILL BECOME SOUTHERLY AS THE WEAK WAVE MOVES INTO THE AREA AND CONTINUE DURING THE OVERNIGHT HOURS. SOUTH-SOUTHWEST WINDS WILL BE ON THE BACK SIDE OF THE WAVE TOMORROW AND PRESSURE GRADIENT WILL TIGHTEN SOME, SO EXPECTING SOME GUSTS OF 22-25KTS DURING THE LATE MORNING AND INTO THE AFTERNOON. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AUTEN SHORT TERM...07 LONG TERM...SMITH AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
614 PM CDT SAT MAY 2 2015 .SHORT TERM...(TONIGHT) ISSUED AT 255 PM CDT SAT MAY 2 2015 A WEAK SHORT WAVE OVER WESTERN IA WILL TRACK EAST TO THE IL/IA BORDER BY MIDNIGHT AND WEAKEN AS IT MOVES ACROSS CENTRAL AND NORTHERN IL OVERNIGHT. AN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS OVER NORTHERN MO AND SOUTHERN IA WILL CONTINUE TO TRACK EASTWARD INTO WEST CENTRAL IL EARLY THIS EVENING BETWEEN 6-8 PM AND INTO CENTRAL IL LATER THIS EVENING AND OVERNIGHT AS SHOWERS BECOME MORE ISOLATED. HAVE 20-30% CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS FROM I-55 NW AFTER SUNSET TONIGHT AND LINGERING ISOLATED LIGHT SHOWERS UNTIL MID SUNDAY MORNING NORTH OF I-72 UNTIL WEAKENING SHORT WAVE PASSES EAST OF IL INTO WESTERN IN BY MIDDAY SUNDAY. MID AND HIGH CLOUDS WILL CONTINUE TO INCREASE FROM THE WEST LATE THIS AFTERNOON AND EVENING WITH SOUTHEAST IL SEEING LESS CLOUD COVER TONIGHT SINCE CLOSER TO HIGH PRESSURE RIDGE OVER SOUTHEAST STATES. LOWS TONIGHT IN THE LOW TO MID 50S WITH COOLEST READINGS NEAR WABASH RIVER WHERE LIGHTER WINDS AND LESS CLOUD COVER TONIGHT. SSW WINDS 7- 14 MPH AND GUSTS 15-20 MPH THIS AFTERNOON TO DIMINISH LESS THAN 10 MPH AFTER SUNSET AND VEER SSE. .LONG TERM...(SUNDAY THROUGH SATURDAY) ISSUED AT 255 PM CDT SAT MAY 2 2015 IOWA SHORTWAVE FORECAST BY MODELS TO TRACK ACROSS THE AREA OVERNIGHT AND INTO THE MORNING HOURS OF SUNDAY BRINGING ISOLATED SHOWERS TO PARTS OF THE FORECAST AREA. SOUNDINGS STILL SHOWING A VERY DRY PROFILE BELOW 725 MB (~8500 FEET) INTO SUNDAY MORNING BEFORE THE WAVE SHIFTS OFF TO OUR EAST DURING THE MORNING. WILL KEEP SLIGHTS GOING FOR A FEW HOURS IN THE MORNING BEFORE THE WAVE MOVES OUT OF THE AREA. OUR ATTENTION THEN TURNS TO A NORTHERN STREAM SHORTWAVE THAT WILL DRAG A COLD FRONT SOUTHEAST INTO THE LOWER GREAT LAKES LATE SUNDAY AND INTO MONDAY INCREASING THE CHANCES FOR MORE WIDESPREAD SHOWERS AND STORMS...ESPECIALLY OVER THE NORTHERN HALF OF THE FORECAST AREA WHERE THE BOUNDARY IS FORECAST TO BECOME STATIONARY. AFTER OUR SLIGHT CHANCES SUNDAY MORNING...THE REST OF THE DAY LOOKS QUIET AND WARM WITH A GUSTY SOUTH TO SOUTHWEST WIND HELPING TO PUSH AFTERNOON TEMPS INTO THE UPPER 70S TO LOWER 80S. POPS START TO RAMP UP SUNDAY NIGHT ACROSS THE FAR NORTHWEST AS THE BOUNDARY EDGES SLOWLY SOUTHEAST WITH MODELS TRENDING SLOWER WITH THE FRONTAL BOUNDARY AND QPF ALONG IT. MAY HAVE TO SLOW THE ONSET OF THE SHOWERS EVEN MORE IF THESE TRENDS CONTINUE. BETTER LOW LEVEL JET SUPPORT AND 850 MB THETA-E ADVECTION REMAINS OUT TO OUR NORTHWEST LATE SUNDAY NIGHT WITH MOST MODELS SUGGESTING THAT A CLUSTER OF STORMS...AT LEAST WHAT`S LEFT OF THEM...WILL APPROACH OUR FAR NORTHWEST COUNTIES WELL AFTER MIDNIGHT SUNDAY NIGHT. THE SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE TO SPREAD SLOWLY SOUTHEAST ON MONDAY AND INTO MONDAY NIGHT WITH THE HIGHER THREAT BEING AGAIN WHERE THE BOUNDARY IS EXPECTED TO BECOME STATIONARY... WHICH AT THIS TIME LOOKS TO BE NORTH OF I-72. FORECAST SOUNDINGS SHOWING MIXED LAYER CAPES OF AROUND 1500 J/KG MONDAY AFTERNOON INTO EARLY MONDAY EVENING WITH THE STRONGER 500 MB WIND FLOW TO OUR NORTH WITH 30-35 KTS FORECAST. SPC HAS A LARGE AREA OF MARGINAL RISK FOR SEVERE STORMS MONDAY AFTERNOON AND EVENING STRETCHING FROM THE SOUTHERN PLAINS UP ACROSS THE NORTHERN HALF OF OUR CWA. SEVERE PARAMETERS BORDERLINE AT THIS TIME BUT WITH THE BOUNDARY IN THE AREA AND FORECAST CONVECTIVE TEMPS AROUND 80...MULTI-CELL STORMS SHOULD DEVELOP DURING THE AFTERNOON AND CONTINUE INTO THE EVENING WITH THE POSSIBILITY FOR SOME GUSTY WINDS...HAIL AND HEAVY RAINFALL WITH SOME OF THE MORE ORGANIZED CLUSTERS OF STORMS THAT FORM ALONG THE STALLED FRONTAL BOUNDARY. MODELS SUGGEST THE BOUNDARY WILL SHIFT NORTH OF THE AREA STARTING ON TUESDAY AS UPPER LEVEL HEIGHTS BUILD IN RESPONSE TO A RATHER VIGOROUS UPPER WAVE THAT WILL BE PUSHING ACROSS THE SOUTHERN ROCKIES AND EVENTUALLY SWING NORTHEAST INTO THE PLAINS BY MID TO LATE IN THE UPCOMING WORK WEEK. WILL INDICATE A BIT OF A LULL IN THE SHOWER AND STORM CHANCES UNTIL LATE THURSDAY OR FRIDAY WHEN THE WAVE WILL APPROACH OUR AREA. TEMPERATURES LOOK TO BE ABOVE NORMAL THRU THE WORK WEEK WITH AFTERNOON HIGHS CLIMBING INTO THE UPPER 70S TO LOWER 80S...WHILE EARLY MORNING LOWS ONLY DROP OFF INTO THE UPPER 50S TO LOWER 60S TUESDAY MORNING...WITH MOST OF OUR AREA SEEING LOW TEMPERATURES IN THE LOW TO MID 60S FOR THE REMAINDER OF THE WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 614 PM CDT SAT MAY 2 2015 HIGH CLOUDS HAVE OVERSPREAD THE TAF SITES THIS EVENING AND AM EXPECTING MID CLOUDS TO ADVECT INTO THE AREA AS A WEAK WAVE MOVES INTO THE AREA FROM THE WEST. SHOWERS IS ASSOCIATED WITH THIS WAVE IN NORTHEASTERN MO AND WEST CENTRAL ILLINOIS. HRRR AND OTHER SHORT TERM MODELS SHOW THESE LIGHT SHOWERS DISSIPATING AS THEY MOVE EAST INTO DRIER AIRMASS OVER ILLINOIS. SO WILL BRING IN LOWER CLOUDS AROUND 8KFT THIS EVENING WITH VCSH. HRRR INDICATES THE SCATTERED SHOWERS COULD LAST UNTIL MORNING, SO WILL KEEP VCSH UNTIL THEN. THEN SKY COVER BECOMES SCATTERED MID CLOUDS OR CLEAR FOR TOMORROW. SOUTHWEST WINDS WILL BECOME SOUTHERLY AS THE WEAK WAVE MOVES INTO THE AREA AND CONTINUE DURING THE OVERNIGHT HOURS. SOUTH-SOUTHWEST WINDS WILL BE ON THE BACK SIDE OF THE WAVE TOMORROW AND PRESSURE GRADIENT WILL TIGHTEN SOME, SO EXPECTING SOME GUSTS OF 22-25KTS DURING THE LATE MORNING AND INTO THE AFTERNOON. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...07 LONG TERM...SMITH AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1012 PM CDT SAT MAY 2 2015 .UPDATE... ISSUED AT 957 PM CDT SAT MAY 2 2015 UPDATE MADE TO THE FORECAST FOR THE EVENING CONCERNS PRECIP UNCERTAINTIES FOR THE OVERNIGHT. THE HI-RES MODELS ALL PICK UP ON SOME ELEVATED INSTABILITY DRIBBLING ACROSS THE FORECAST AREA TONIGHT WHILE THE OTHER MODELS KEEP US DRY. WATER VAPOR SHOWS A VORT MAX AND A SECONDARY SHORTWAVE PUSHING EAST OUT OF OMAHA WHICH THE HRRR BRINGS ACROSS IOWA THROUGH THE OVERNIGHT. CERTAINLY THE STORMS OVER EASTERN NEBRASKA HAVE HELD TOGETHER AS THEY CROSSED INTO IOWA AND ADDITIONAL SHOWERS/STORMS ARE CURRENTLY RE- DEVELOPING ACROSS OUR WESTERN FORECAST AREA. THE UPDATE BROUGHT PRECIP BACK INTO THE WEST THIS EVENING INTO THE OVERNIGHT BUT JUST HOW LONG IT WILL PERSIST IS THE QUESTION. DESPITE THE HI-RES MODELS SOLUTION...THE STORMS OUT WEST ARE DYING THE FURTHER EAST THEY COME AND WE ARE FORECAST TO LOSE AT LEAST SOME OF OUR INSTABILITY OVERNIGHT. ANY SHOWERS THAT WOULD HAPPEN WOULD BE VERY HIT OR MISS IN POCKETS OF RESIDUAL INSTABILITY WHICH ARE JUST TOO HARD TO FORECAST AND CERTAINLY NOT WORTH PAINTING SLIGHT CHANCE POPS ACROSS OUR ENTIRE FORECAST AREA...AT LEAST AT THIS POINT. IF WE SEE BETTER EVIDENCE OF MORE WIDESPREAD INSTABILITY TO COINCIDE WITH THE HRRR`S WEAK SHORTWAVE AND VORT MAX DRIFTING ACROSS THE CWA OVERNIGHT WE MAY NEED TO ADD A LITTLE MORE WIDESPREAD SLIGHT CHANCE POPS TO THE GRIDS. CERTAINLY AN INTERESTING AND NOT CLEAR CUT FORECAST TONIGHT. && .SHORT TERM /TONIGHT/... ISSUED AT 310 PM CDT SAT MAY 2 2015 AREA OF SHOWERS AND A FEW THUNDERSTORMS HAS SLOWLY PROGRESSED EASTWARD ACROSS THE SOUTHERN HALF OF IOWA TODAY. THIS ACTIVITY IS IN AN AREA OF MID LEVEL THETA-E ADVECTION AND WARM ADVECTION AHEAD OF A WEAK SHORTWAVE THAT IS QUITE EVIDENT IN THE WATER VAPOR IMAGERY. THIS ACTIVITY WILL CONTINUE TO PROGRESS EASTWARD THIS EVENING WITHOUT AND EVENTUALLY EXIT THE EAST LATER THIS EVENING AS SUBSIDENCE INCREASES FROM THE WEST BEHIND THE WAVE. OVERNIGHT WILL BE RELATIVELY QUIET WITH MODEST SOUTHERLY SURFACE WINDS AND GENERALLY CLEAR TO PARTLY CLOUDY SKIES. HAVE KEPT TEMPERATURES AT OR SLIGHTLY ABOVE GUIDANCE GIVEN THE ONGOING WARM ADVECTION OVERNIGHT AND INCREASING MOISTURE. .LONG TERM /SUNDAY THROUGH SATURDAY/... ISSUED AT 310 PM CDT SAT MAY 2 2015 ACTIVE WEATHER PATTERN SETS UP ACROSS THE REGION SUNDAY NIGHT AND LASTS THROUGHOUT MUCH OF THE WEEK. SEVERE POTENTIAL SUNDAY LATE AFTERNOON INTO THE EVENING OVER THE NORTH BUT NO OTHER CLEAR CUT TIME FRAME FOR SEVERE WEATHER THE REMAINDER OF THE WEEK. LEANED TOWARD A BLEND OF THE NAM12/ECMWF FOR TEMPS AND POPS THROUGH TUESDAY...THEN A GFS/ECMWF BLEND THROUGH THE REST OF THE WEEK. SUNDAY INTO TUESDAY...GOOD SURGE OF WAA ACROSS THE STATE WILL PUSH MAX TEMPS WELL INTO THE 80S ACROSS CENTRAL IOWA. BUMPED UP MAX TEMPS UP A COUPLE DEGREES AS WELL AS WINDS DURING THE AFTERNOON WITH THE STRONG SOUTHWEST FLOW AND MIXING TO AROUND 900MB. BOUNDARY SAGS SOUTH INTO NORTHERN IOWA SUNDAY EVENING AND HELPS WEAKEN THE CAP OVER NORTHERN IOWA PAST 22Z SUNDAY. MUCAPE INCREASES TO 1500-2200 J/KG LATE IN THE AFTERNOON INTO THE EVENING WITH DEEP LAYER SHEAR STRONG ENOUGH TO SUPPORT UPDRAFTS FOR A CONSIDERABLE TIME FRAME. LOW LEVEL SHEAR IS WEAK...SO MAINLY LOOKING AT ELEVATED HAIL OVER THE NORTHERN SECTIONS OF THE FORECAST AREA WITH A SECONDARY THREAT OF DAMAGING WINDS PER LOW VALUES OF DCAPE PRESENT. TEMPERATURES MONDAY WILL BE COOLER WITH THE BOUNDARY STALLING ACROSS CENTRAL IOWA FROM WEST TO EAST...BASICALLY ALONG INTERSTATE 80 TO HIGHWAY 30 CORRIDOR THROUGH MONDAY EVENING. THUNDERSTORMS CHANCES CONTINUED SOUTH OF THE BOUNDARY DURING THE DAY MONDAY AND BY MONDAY NIGHT INTO TUESDAY...THE WARM FRONT SURGES BACK NORTHWARD AND HAVE LIKELY POPS GOING ACROSS THE ENTIRE FORECAST AREA THROUGH TUESDAY MORNING WITH FORCING AND MOISTURE TRANSPORT INTO THE STATE DURING THIS TIME. SEVERE THREAT LOOKS MINIMAL ATTM WITH THE LACK OF SIGNIFICANT INSTABILITY AND SHEAR PRESENT. THE WARM FRONT CONTINUES TO SURGE NORTH INTO SOUTHERN MINNESOTA ON TUESDAY AND PLACES THE FORECAST AREA WELL INTO THE WARM SECTOR. THE 850MB TEMPS WARM TO +12C TO +14C AND BUMPED UP MAX TEMPS CONSIDERABLY...ESPECIALLY OVER NORTHERN IOWA FOR TUESDAY. THE ATMOSPHERE BECOMES STABILIZED BY TUESDAY NIGHT INTO WEDNESDAY...AND WENT COMPLETELY DRY ACROSS MUCH OF THE FORECAST AREA DURING THIS TIME. MODELS ARE IN GOOD AGREEMENT WITH THIS DRY PERIOD. WEDNESDAY THROUGH SATURDAY...MORE PERIODIC RAIN CHANCES DURING THIS TIME FRAME WITH THE BEST POTENTIAL LOOK TO BE LATE WEDNESDAY INTO THURSDAY AS A DECENT SHORTWAVE EJECTS OUT OF THE CENTRAL ROCKIES INTO WESTERN IOWA. AFTER THURSDAY...DEPENDING ON WHICH MODEL...THERE IS THUNDERSTORM CHANCES EACH PERIOD THROUGH NEXT WEEKEND. && .AVIATION...03/00Z ISSUED AT 635 PM CDT SAT MAY 2 2015 UPPER LEVEL WAVE MOVING ACROSS CENTRAL IOWA THIS EVENING AND PRODUCING SCT SHRA WITH ISOLD TSRA MAINLY AFFECTING KDSM AND KOTM. THIS WAVE SHOULD PASS EAST BY 03Z OR SO DIMINISHING ANY THREAT FOR PRECIP THOUGH THERE IS SOME SUGGESTION THAT A MOISTENING MID LAYER COULD PRODUCE SOME ISOLD SHRA NEAR KALO BEFORE 06Z AS WELL BEFORE THE WAVE FINALLY EXITS. VFR CIGS EXPECTED THROUGH THE TAF PERIOD AND SOUTHERLY SFC WIND WILL DIMINISH TO AROUND 10-15KT THROUGH 12Z THEN INCREASE ONCE AGAIN TO 15G25KTS AFT 16-18Z. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...FAB SHORT TERM...COGIL LONG TERM...PODRAZIK AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
339 PM CDT FRI MAY 1 2015 .SYNOPSIS... ISSUED AT 321 PM CDT FRI MAY 1 2015 WEAK FRONTAL BOUNDARY WILL DISSIPATE OVER IOWA TONIGHT AS A FRONTAL BOUNDARY DEVELOPS TO THE NORTHWEST ON SATURDAY. THIS FRONT WILL MOVE SOUTHEAST THROUGH THE AREA SUNDAY AFTERNOON AND NIGHT BEFORE STALLING. THE OVERALL WEATHER PATTERN WILL BE ACTIVE WITH THE FRONT IN THE VICINITY THROUGH THE NEXT WEEK. && .SHORT TERM /TONIGHT/... ISSUED AT 321 PM CDT FRI MAY 1 2015 MAIN FORECAST CONCERN WILL BE PRECIPITATION CHANCES THIS EVENING AND AGAIN VERY LATE IN THE PERIOD. ONGOING PRECIPITATION ACROSS CENTRAL PORTION OF THE CWA WILL PERSIST THROUGH THE EVENING...CONTINUING TO PUSH SLOWLY SOUTHEAST. WEAK BOUNDARY AND FORCING WITH PRECIPITATION WILL CONTINUE TO WEAKEN AND WILL SEE PRECIPITATION CONTINUE TO BECOME MORE SCATTERED THROUGH THE LATE EVENING. HRRR MODEL HAS A GOOD HANDLE ON PRECIPITATION TRENDS...AND HAVE TRENDED THIS WAY FOR POPS. GIVEN CURRENT LACK OF INSTABILITY HAVE LEFT THUNDER MENTION OUT...THOUGH COULD SEE SOME ISOLATED THUNDER IN THE LATE AFTERNOON OR EARLY EVENING WITH INCREASING INSTABILITY IN THE FAR WEST. SHORTWAVE LIFTING NORTH FROM KS/NE WILL BEGIN TO PUSH INTO SOUTHWEST NEAR 12Z. HAVE CUT BACK ON POPS WITH SLIGHTLY SLOWER PROGRESSION OF WAVE AND MOISTURE NOTED...NOT PUSHING INTO CWA UNTIL AFTER 12Z. HOWEVER...PLACEMENT MAY BE TOO FAR SOUTH ACROSS THE WEST. HAVE KEPT OVERNIGHT LOW TEMPERATURES DOWN A DEGREE OR TWO GIVEN HOW PRECIPITATION LIMITED DAYTIME HIGHS...AND EXPECT CLEARING SKIES ACROSS THE NORTH TONIGHT. .LONG TERM /SATURDAY THROUGH FRIDAY/... ISSUED AT 321 PM CDT FRI MAY 1 2015 CONTINUED WAA AND POCKETS OF STRONGER THETA-E WILL DOMINATE THROUGH THE NEXT WEEK. A WEAK FEATURE WILL MOVE THROUGH THE AREA ON SATURDAY BRINGING WIDELY SCATTERED SHOWERS AND THUNDERSTORMS...BUT NOTHING TO REALLY FOCUS ON WITH THIS. SUNDAY LOOKS TO BE MORE ACTIVE AS DEW POINTS COME UP AND A STRONGER FRONT MOVES IN. CAPE RISES TO AROUND 2000 J/KG OR SO BY MID DAY SUNDAY WITH LITTLE RESIDUAL CAP. OTHER PARAMETERS ARE NOT AS FAVORABLE WITH INFLOW RELATIVELY WEAK AND OVERALL CONVERGENCE ALONG THE FRONT NOT OPTIMAL. STILL, THUNDER CHANCES ARE DECENT AND IT APPEARS THAT MARGINAL TO SLIGHT THREAD FOR SEVERE LOOKS REASONABLE. THE REST OF THE WEEK WILL BE WARMER THAN NORMAL AND WET. TROUGH IN THE WEST WILL SEND OUT PERIODIC PIECES WITH THE NEXT STRONGER PIECE ARRIVING ABOUT THURSDAY...THE NEXT BEYOND THE FORECAST PERIOD. THOUGH THE SEVERE THREAT LOOKS RELATIVELY LOW...THE CHANCES FOR WIDESPREAD RAINFALL IN EXCESS OF 2 INCHES IN A WEEK IS PRETTY GOOD. DO NOT EXPECT THE RAINFALL TO BE A PROBLEM...BUT IT WILL PUT A CRIMP IN PLANTING PROGRESS. && .AVIATION...01/18Z ISSUED AT 1220 PM CDT FRI MAY 1 2015 BOUNDARY WILL BRING CHANCE FOR -RA OR -DZ TO SITES BEFORE 00Z...THOUGH WILL BE MOSTLY SCATTERED AND CONDITIONS WILL REMAIN VFR. WINDS WILL BECOME MORE SOUTHERLY AND DECREASE AFTER 00Z. LATE IN PERIOD...BEYOND 12Z WINDS WILL SHIFT TO THE SOUTHWEST AND WILL INCREASE. IN ADDITION...SHRA WILL BE POSSIBLE AND KDSM AND KFOD VERY LATE IN PERIOD OR BEYOND PERIOD. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...MS MAY 15 SHORT TERM...AWB LONG TERM...MS MAY 15 AVIATION...AWB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
821 PM MDT SAT MAY 2 2015 .UPDATE... ISSUED AT 814 PM MDT SAT MAY 2 2015 BASED ON RADAR TRENDS OVER THE LAST COUPLE HOURS AND LATEST MODEL DATA...HAVE LOWERED RAINFALL CHANCES ACROSS MOST OF THE AREA EXCEPT FOR THE YUMA COUNTY AREA AND GREELEY AND WICHITA COUNTIES WHERE RAINFALL IS OR WILL BE MOVING OVER IN THE NEXT FEW HOURS. LATEST DATA INDICATES THE LIFT OVER THE NORTHWEST QUADRANT OF THE IS AT ITS BEST NOW AND WILL DECLINE RATHER QUICKLY OVER THE NEXT COUPLE OF HOURS. FURTHER SOUTH...THE TRACK OF THE 700MB SHORT WAVE TROUGH HAS BEEN PUSHED FURTHER SOUTH FOR TONIGHT...WITH THE MAJORITY OF THE LIFT REMAINING SOUTH OF THE AREA. STILL EXPECTING RAINFALL CHANCES TO END BY OR SHORTLY AFTER MIDNIGHT AS THE LIFT WITH THE SHORT WAVE TROUGH COMES TO AN END AS THE TROUGH FILLS/MOVES OUT OF THE AREA. UPDATE ISSUED AT 552 PM MDT SAT MAY 2 2015 MAIN CHANGE WAS TO INCREASE RAINFALL CHANCES FOR THE EVENING BASED ON LATEST DATA. LATEST RADAR SHOWS LINE OF STORMS AHEAD OF A 700MB SHORT WAVE TROUGH OVER EASTERN COLORADO. 700-500MB FRONTOGENESIS STRENGTHENS RAPIDLY DURING THE EARLY EVENING AND SHIFTS EAST TO THE CENTRAL PART OF THE AREA BY MID EVENING ACCOMPANYING THE 700MB SHORT WAVE TROUGH. MEANWHILE ISENTROPIC LIFT STRENGTHENS THROUGH THE FIRST HALF OF THE EVENING...WITH THE STRONGEST LIFT WEST OF HIGHWAY 25 WHILE CONDENSATION PRESSURE DEFICITS DECLINE. TOWARD MIDNIGHT THE LIFT DECLINES AND CONDENSATION PRESSURE DEFICITS INCREASE AS THE SHORT WAVE TROUGH MOVES ACROSS THE EAST HALF OF THE AREA. WITH THIS IN MIND HAVE THE HIGHEST CHANCES FOR RAINFALL DURING THE FIRST HALF OF THE EVENING MAINLY FOR LOCATIONS SOUTH OF I-70. TOWARD MIDNIGHT...AS ENVIRONMENT BECOMES LESS FAVORABLE FOR RAINFALL...HAVE RAINFALL CHANCES QUICKLY DECLINING OVER THE EAST HALF OF THE AREA. LOOKING AT THE SEVERE WEATHER POTENTIAL...STRONGEST STORMS STILL REMAIN WEST OF THE AREA WHERE THE BEST FORCING IS LOCATED. HAVE HAD SOME ISOLATED STORMS DEVELOP ALONG THE SURFACE TROUGH EXTENDING FROM SOUTHWEST TO NORTHEAST OVER THE CENTRAL PART OF THE AREA. HOWEVER THESE STORMS HAVE BEEN TOO FAR REMOVED FROM THE BETTER UPPER LEVEL FORCING TO LAST VERY LONG AND HAVE BEEN FAIRLY WEAK. AS STORMS MOVE EAST INTO THE AREA...THE LIKELIHOOD FOR SEVERE OUTFLOW WINDS INCREASES OVER THE NEXT HOUR OR SO BEFORE THE INVERSION DEVELOPS. OVERALL SEVERE STORMS ARE MOST LIKELY WEST OF HIGHWAY 25 PRIOR TO 9 PM CT OR 8 PM MT. AFTER THAT THE FORCING...SHEAR...AND INSTABILITY DECLINE. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 157 PM MDT SAT MAY 2 2015 LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW WESTERLY ZONAL FLOW IN PLACE FROM THE GREAT BASIN ACROSS THE CENTRAL ROCKIES INTO THE MISSISSIPPI VALLEY WITH EMBEDDED H5/H7 SHORTWAVE TROUGHS MOVING THROUGH THE MEAN FLOW. AT THE SURFACE LEE TROUGH HAS DEVELOPED ACROSS EASTERN COLORADO WITH A MEAN SURFACE TROUGH FROM THE NE PANHANDLE AND ALONG THE COLORADO BORDER. THUNDERSTORM ACTIVITY HAS ALREADY DEVELOPED ALONG THE CHEYENNE RIDGE AND HIGHER TERRAIN IN COLORADO. THIS AFTERNOON-TONIGHT...RAP ANALYSIS (WHICH IS IN LINE WITH EARLIER NAM) SHOWS 2000 J/KG OF SB CAPE IN PLACE ALONG AND AHEAD OF THE SURFACE TROUGH...CENTERED OVER OUR CWA. CINH APPEARS TO BE WEAKENING...HOWEVER ONLY SOME SHALLOW CU HAVE FORMED SO FAR THIS AFTERNOON. AS MID LEVEL VORTICITY ROTATES FROM THE CENTRAL ROCKIES INTO EASTERN COLORADO I WOULD EXPECT DEVELOPMENT TO SPREAD EAST WHICH IS IN LINE WITH SYNOPTIC SCALE GUIDANCE. HRRR/RAP BOTH INDICATE ISOLATED ACTIVITY DEVELOPING ALONG AND EAST OF THE SURFACE TROUGH OVER OUR CWA WITH ADDITIONAL ACTIVITY SPREADING IN FROM THE WEST. BULK SHEER/HELICITY ARE NOT VERY IMPRESSIVE AT THIS POINT WHERE BETTER INSTABILITY IS IN PLACE (WEST). MOISTURE PROFILES ARE NOT PARTICULARLY IMPRESSIVE...AND THIS COULD LIMIT COVERAGE TO ISOLATE/SCATTERED. BETTER PRECIP SIGNAL AND INSTABILITY ARE SHOW IN IN THE LOWER SHEER ENVIRONMENT...WHERE PULSE TYPE THUNDERSTORMS WOULD BE MORE LIKELY. STEEP MID LEVEL LAPSE RATES AND MODERATE INSTABILITY COULD SUPPORT STRONGER UPDRAFTS/CORES...WITH LARGE HAIL/SEVERE WINDS POSSIBLE. DCAPE VALUES 1000-1500 J/KG AND IN HIGHER TD DEPRESSIONS (MAINLY WEST) DO RAISE A CONCERN FOR INCREASED MICROBURST POTENTIAL WITH SOME OF THESE STORMS. IF ANY OF THIS ACTIVITY WAS TO MOVE INTO THE EASTERN CWA IT COULD BECOME MORE ORGANIZED WITH INCREASING SPEED SHEER (35KT BULK EFFECTIVE SHEER AROUND 00Z). AS THE SUN SETS AND WE LOOSE DAYTIME HEATING ANY LINGERING ACTIVITY SHOULD QUICKLY WEAKEN AS THERE IS ELEVATED CAPE LATE AND ONLY A WEAK LLJ IN PLACE OVERNIGHT. SUNDAY...ANOTHER VERY WARM DAY IS EXPECTED AS SURFACE TROUGH DEEPENS A LITTLE OVER THE CWA AND WAA INCREASES OVER THE CWA. THIS IS IN RESPONSE TO A STRONGER SHORTWAVE TROUGH MOVING INTO THE NORTHERN PLAINS AND A COLD FRONT DROPPING SOUTH INTO NORTHERN NEBRASKA. HIGHS SHOULD BE SIMILAR TO TODAY WITH MOST IN THE 80S...AND A FEW LOCATIONS APPROACHING 90 (MAINLY MCCOOK/HILL CITY). SURFACE TROUGH WILL SHIFT JUST A LITTLE BIT EAST AND LOW LEVEL MOISTURE RETURN COULD BRING HIGHER TD VALUES INTO NORTH CENTRAL KS. NAM MAY BE A LITTLE HIGH...BUT EITHER WAY THIS BETTER BL MOISTURE WILL SUPPORT HIGHER CAPE VALUES IN THE AFTERNOON IN THE 2000-2500 J/KG RANGE. SHEER MAY ALSO BE A LITTLE BIT BETTER WHERE GOOD INSTABILITY IS IN PLACE THAN TODAY...SO THERE MAY BE A BIGGER THREAT FOR MORE ORGANIZE THUNDERSTORM DEVELOPMENT IF ANYTHING IS TO DEVELOP IN THE AFTERNOON. THUNDERSTORM ACTIVITY IS SHOWN TO INITIATE PRIMARILY ALONG SURFACE TROUGH IN THE AFTERNOON. HOWEVER WITH DRIER MOISTURE PROFILES AGAIN IN PLACE COVERAGE COULD BE LIMITED AT LEAST UNTIL LATER WHEN BETTER LARGE SCALE FORCING/DEEPER MOISTURE MOVINGS IN TO THE REGION FROM THE NORTHWEST. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 233 PM MDT SAT MAY 2 2015 UPPER LEVEL FLOW WILL BE SOUTHWEST FROM SUNDAY NIGHT THROUGH TUESDAY AHEAD OF A LOW MOVING EAST FROM THE DESERT SOUTHWEST INTO THE CENTRAL AND SOUTHERN ROCKIES. A SURFACE TROUGH NEAR NORTHWEST KANSAS WILL MOVE EAST MONDAY. HIGH PRESSURE WILL BUILD INTO NORTHWEST KANSAS MONDAY NIGHT AND TUESDAY. AN AREA OF LOW PRESSURE WILL MOVE INTO COLORADO TUESDAY. A SHORTWAVE SHOULD AFFECT THE FA SUNDAY EVENING AND INITIATE STORMS NEAR THE SURFACE TROUGH OVER NORTHEAST COLORADO INTO SOUTHWEST NEBRASKA. PLAN TO USE HIGH CHANCE POPS IN THAT AREA WITH LOWER CHANCE POPS ELSEWHERE ACROSS THE FA. PLAN TO KEEP HIGHER CHANCE POPS ACROSS THE NORTHERN FA AS STORMS DRIFT NORTHEAST INTO THE FA OVERNIGHT. THERE SHOULD BE A LULL MONDAY MORNING BEHIND THE EXITING WAVE. POPS WILL INCREASE TO HIGH CHANCE MONDAY AFTERNOON AND EVENING AS THE NEXT SHORTWAVE COMES THROUGH. MOISTURE AND DYNAMICS LOOK GOOD FOR MONDAY NIGHT SO WILL CONTINUE HIGH CHANCE AND LIKELY POPS. GOOD DYNAMICS AND MOISTURE CONTINUE TO STREAM ACROSS THE FA TUESDAY AS THE MAIN TROUGH MOVES INTO THE AREA. PRECIPITABLE WATER VALUES ACROSS THE FA FOR TUESDAY RANGE FROM 1.0 TO 1.2 INCHES. PLAN TO CONTINUE LIKELY AND DEFINITE POPS. MIN TEMPERATURES THROUGH MONDAY NIGHT SHOULD COOL INTO THE MID 40S IN EASTERN COLORADO TO THE MID 50S IN THE EASTERN FA. MAX TEMPERATURES MONDAY SHOULD RANGE FROM THE LOWER 60S IN EASTERN COLORADO TO THE LOWER 70S IN THE EASTERN FA. IN THE EXTENDED...(TUESDAY NIGHT THROUGH SATURDAY)...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE CENTRAL PLAINS TUESDAY NIGHT AND WEDNESDAY AND THEN LIFT OUT OF THE AREA WEDNEDAY NIGHT. GOOD DYNAMICS AND MOISTURE SUPPORT HIGH POPS THROUGH WEDNESDAY. POPS WILL DECREASE TO CHANCE THURSDAY AND FRIDAY BEHIND THE EXITING TROUGH WITH A COUPLE OF SHORTWAVES IN SOUTHWEST FLOW PRODUCING STORMS. POPS WILL INCREASE AGAIN SATURDAY AS THE NEXT UPPER LEVEL TROUGH BEGINS IMPACTING THE CENTRAL PLAINS. MIN TEMPERATURES SHOULD RANGE FROM 45 TO 55 THROUGH FRIDAY NIGHT WITH COOLER READINGS IN EASTERN COLORADO. MAX TEMPERATURES WILL GENERALLY WARM TO THE 70S EACH DAY WITH SOME UPPER 60S POSSIBLE IN EASTERN COLORADO AND NEAR 80 IN THE EASTERN FA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 552 PM MDT SAT MAY 2 2015 VFR CONDITIONS EXPECTED FOR THE 0Z TAFS. MAIN ISSUE WILL BE TIMING OF THE STORMS FOR KGLD DURING THE EVENING. AM THINKING THE MAJORITY OF THE ACTIVITY SHOULD BE SOUTH OF KGLD...BUT THERE WILL BE A BRIEF WINDOW FOR SOME STORMS NEAR THE SITE. OTHERWISE LIGHT SOUTHWEST WINDS WILL TURN TO THE NORTHWEST SUNDAY MORNING AS A SURFACE TROUGH MOVES THROUGH FROM THE WEST. BEHIND THE TROUGH WINDS WILL TURN CLOCKWISE TO THE NORTHEAST BY LATE AFTERNOON. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...DR LONG TERM...FS AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
613 PM MDT SAT MAY 2 2015 .UPDATE... ISSUED AT 552 PM MDT SAT MAY 2 2015 MAIN CHANGE WAS TO INCREASE RAINFALL CHANCES FOR THE EVENING BASED ON LATEST DATA. LATEST RADAR SHOWS LINE OF STORMS AHEAD OF A 700MB SHORT WAVE TROUGH OVER EASTERN COLORADO. 700-500MB FRONTOGENESIS STRENGTHENS RAPIDLY DURING THE EARLY EVENING AND SHIFTS EAST TO THE CENTRAL PART OF THE AREA BY MID EVENING ACCOMPANYING THE 700MB SHORT WAVE TROUGH. MEANWHILE ISENTROPIC LIFT STRENGTHENS THROUGH THE FIRST HALF OF THE EVENING...WITH THE STRONGEST LIFT WEST OF HIGHWAY 25 WHILE CONDENSATION PRESSURE DEFICITS DECLINE. TOWARD MIDNIGHT THE LIFT DECLINES AND CONDENSATION PRESSURE DEFICITS INCREASE AS THE SHORT WAVE TROUGH MOVES ACROSS THE EAST HALF OF THE AREA. WITH THIS IN MIND HAVE THE HIGHEST CHANCES FOR RAINFALL DURING THE FIRST HALF OF THE EVENING MAINLY FOR LOCATIONS SOUTH OF I-70. TOWARD MIDNIGHT...AS ENVIRONMENT BECOMES LESS FAVORABLE FOR RAINFALL...HAVE RAINFALL CHANCES QUICKLY DECLINING OVER THE EAST HALF OF THE AREA. LOOKING AT THE SEVERE WEATHER POTENTIAL...STRONGEST STORMS STILL REMAIN WEST OF THE AREA WHERE THE BEST FORCING IS LOCATED. HAVE HAD SOME ISOLATED STORMS DEVELOP ALONG THE SURFACE TROUGH EXTENDING FROM SOUTHWEST TO NORTHEAST OVER THE CENTRAL PART OF THE AREA. HOWEVER THESE STORMS HAVE BEEN TOO FAR REMOVED FROM THE BETTER UPPER LEVEL FORCING TO LAST VERY LONG AND HAVE BEEN FAIRLY WEAK. AS STORMS MOVE EAST INTO THE AREA...THE LIKELIHOOD FOR SEVERE OUTFLOW WINDS INCREASES OVER THE NEXT HOUR OR SO BEFORE THE INVERSION DEVELOPS. OVERALL SEVERE STORMS ARE MOST LIKELY WEST OF HIGHWAY 25 PRIOR TO 9 PM CT OR 8 PM MT. AFTER THAT THE FORCING...SHEAR...AND INSTABILITY DECLINE. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 157 PM MDT SAT MAY 2 2015 LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW WESTERLY ZONAL FLOW IN PLACE FROM THE GREAT BASIN ACROSS THE CENTRAL ROCKIES INTO THE MISSISSIPPI VALLEY WITH EMBEDDED H5/H7 SHORTWAVE TROUGHS MOVING THROUGH THE MEAN FLOW. AT THE SURFACE LEE TROUGH HAS DEVELOPED ACROSS EASTERN COLORADO WITH A MEAN SURFACE TROUGH FROM THE NE PANHANDLE AND ALONG THE COLORADO BORDER. THUNDERSTORM ACTIVITY HAS ALREADY DEVELOPED ALONG THE CHEYENNE RIDGE AND HIGHER TERRAIN IN COLORADO. THIS AFTERNOON-TONIGHT...RAP ANALYSIS (WHICH IS IN LINE WITH EARLIER NAM) SHOWS 2000 J/KG OF SB CAPE IN PLACE ALONG AND AHEAD OF THE SURFACE TROUGH...CENTERED OVER OUR CWA. CINH APPEARS TO BE WEAKENING...HOWEVER ONLY SOME SHALLOW CU HAVE FORMED SO FAR THIS AFTERNOON. AS MID LEVEL VORTICITY ROTATES FROM THE CENTRAL ROCKIES INTO EASTERN COLORADO I WOULD EXPECT DEVELOPMENT TO SPREAD EAST WHICH IS IN LINE WITH SYNOPTIC SCALE GUIDANCE. HRRR/RAP BOTH INDICATE ISOLATED ACTIVITY DEVELOPING ALONG AND EAST OF THE SURFACE TROUGH OVER OUR CWA WITH ADDITIONAL ACTIVITY SPREADING IN FROM THE WEST. BULK SHEER/HELICITY ARE NOT VERY IMPRESSIVE AT THIS POINT WHERE BETTER INSTABILITY IS IN PLACE (WEST). MOISTURE PROFILES ARE NOT PARTICULARLY IMPRESSIVE...AND THIS COULD LIMIT COVERAGE TO ISOLATE/SCATTERED. BETTER PRECIP SIGNAL AND INSTABILITY ARE SHOW IN IN THE LOWER SHEER ENVIRONMENT...WHERE PULSE TYPE THUNDERSTORMS WOULD BE MORE LIKELY. STEEP MID LEVEL LAPSE RATES AND MODERATE INSTABILITY COULD SUPPORT STRONGER UPDRAFTS/CORES...WITH LARGE HAIL/SEVERE WINDS POSSIBLE. DCAPE VALUES 1000-1500 J/KG AND IN HIGHER TD DEPRESSIONS (MAINLY WEST) DO RAISE A CONCERN FOR INCREASED MICROBURST POTENTIAL WITH SOME OF THESE STORMS. IF ANY OF THIS ACTIVITY WAS TO MOVE INTO THE EASTERN CWA IT COULD BECOME MORE ORGANIZED WITH INCREASING SPEED SHEER (35KT BULK EFFECTIVE SHEER AROUND 00Z). AS THE SUN SETS AND WE LOOSE DAYTIME HEATING ANY LINGERING ACTIVITY SHOULD QUICKLY WEAKEN AS THERE IS ELEVATED CAPE LATE AND ONLY A WEAK LLJ IN PLACE OVERNIGHT. SUNDAY...ANOTHER VERY WARM DAY IS EXPECTED AS SURFACE TROUGH DEEPENS A LITTLE OVER THE CWA AND WAA INCREASES OVER THE CWA. THIS IS IN RESPONSE TO A STRONGER SHORTWAVE TROUGH MOVING INTO THE NORTHERN PLAINS AND A COLD FRONT DROPPING SOUTH INTO NORTHERN NEBRASKA. HIGHS SHOULD BE SIMILAR TO TODAY WITH MOST IN THE 80S...AND A FEW LOCATIONS APPROACHING 90 (MAINLY MCCOOK/HILL CITY). SURFACE TROUGH WILL SHIFT JUST A LITTLE BIT EAST AND LOW LEVEL MOISTURE RETURN COULD BRING HIGHER TD VALUES INTO NORTH CENTRAL KS. NAM MAY BE A LITTLE HIGH...BUT EITHER WAY THIS BETTER BL MOISTURE WILL SUPPORT HIGHER CAPE VALUES IN THE AFTERNOON IN THE 2000-2500 J/KG RANGE. SHEER MAY ALSO BE A LITTLE BIT BETTER WHERE GOOD INSTABILITY IS IN PLACE THAN TODAY...SO THERE MAY BE A BIGGER THREAT FOR MORE ORGANIZE THUNDERSTORM DEVELOPMENT IF ANYTHING IS TO DEVELOP IN THE AFTERNOON. THUNDERSTORM ACTIVITY IS SHOWN TO INITIATE PRIMARILY ALONG SURFACE TROUGH IN THE AFTERNOON. HOWEVER WITH DRIER MOISTURE PROFILES AGAIN IN PLACE COVERAGE COULD BE LIMITED AT LEAST UNTIL LATER WHEN BETTER LARGE SCALE FORCING/DEEPER MOISTURE MOVINGS IN TO THE REGION FROM THE NORTHWEST. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 233 PM MDT SAT MAY 2 2015 UPPER LEVEL FLOW WILL BE SOUTHWEST FROM SUNDAY NIGHT THROUGH TUESDAY AHEAD OF A LOW MOVING EAST FROM THE DESERT SOUTHWEST INTO THE CENTRAL AND SOUTHERN ROCKIES. A SURFACE TROUGH NEAR NORTHWEST KANSAS WILL MOVE EAST MONDAY. HIGH PRESSURE WILL BUILD INTO NORTHWEST KANSAS MONDAY NIGHT AND TUESDAY. AN AREA OF LOW PRESSURE WILL MOVE INTO COLORADO TUESDAY. A SHORTWAVE SHOULD AFFECT THE FA SUNDAY EVENING AND INITIATE STORMS NEAR THE SURFACE TROUGH OVER NORTHEAST COLORADO INTO SOUTHWEST NEBRASKA. PLAN TO USE HIGH CHANCE POPS IN THAT AREA WITH LOWER CHANCE POPS ELSEWHERE ACROSS THE FA. PLAN TO KEEP HIGHER CHANCE POPS ACROSS THE NORTHERN FA AS STORMS DRIFT NORTHEAST INTO THE FA OVERNIGHT. THERE SHOULD BE A LULL MONDAY MORNING BEHIND THE EXITING WAVE. POPS WILL INCREASE TO HIGH CHANCE MONDAY AFTERNOON AND EVENING AS THE NEXT SHORTWAVE COMES THROUGH. MOISTURE AND DYNAMICS LOOK GOOD FOR MONDAY NIGHT SO WILL CONTINUE HIGH CHANCE AND LIKELY POPS. GOOD DYNAMICS AND MOISTURE CONTINUE TO STREAM ACROSS THE FA TUESDAY AS THE MAIN TROUGH MOVES INTO THE AREA. PRECIPITABLE WATER VALUES ACROSS THE FA FOR TUESDAY RANGE FROM 1.0 TO 1.2 INCHES. PLAN TO CONTINUE LIKELY AND DEFINITE POPS. MIN TEMPERATURES THROUGH MONDAY NIGHT SHOULD COOL INTO THE MID 40S IN EASTERN COLORADO TO THE MID 50S IN THE EASTERN FA. MAX TEMPERATURES MONDAY SHOULD RANGE FROM THE LOWER 60S IN EASTERN COLORADO TO THE LOWER 70S IN THE EASTERN FA. IN THE EXTENDED...(TUESDAY NIGHT THROUGH SATURDAY)...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE CENTRAL PLAINS TUESDAY NIGHT AND WEDNESDAY AND THEN LIFT OUT OF THE AREA WEDNEDAY NIGHT. GOOD DYNAMICS AND MOISTURE SUPPORT HIGH POPS THROUGH WEDNESDAY. POPS WILL DECREASE TO CHANCE THURSDAY AND FRIDAY BEHIND THE EXITING TROUGH WITH A COUPLE OF SHORTWAVES IN SOUTHWEST FLOW PRODUCING STORMS. POPS WILL INCREASE AGAIN SATURDAY AS THE NEXT UPPER LEVEL TROUGH BEGINS IMPACTING THE CENTRAL PLAINS. MIN TEMPERATURES SHOULD RANGE FROM 45 TO 55 THROUGH FRIDAY NIGHT WITH COOLER READINGS IN EASTERN COLORADO. MAX TEMPERATURES WILL GENERALLY WARM TO THE 70S EACH DAY WITH SOME UPPER 60S POSSIBLE IN EASTERN COLORADO AND NEAR 80 IN THE EASTERN FA. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 552 PM MDT SAT MAY 2 2015 VFR CONDITIONS EXPECTED FOR THE 0Z TAFS. MAIN ISSUE WILL BE TIMING OF THE STORMS FOR KGLD DURING THE EVENING. AM THINKING THE MAJORITY OF THE ACTIVITY SHOULD BE SOUTH OF KGLD...BUT THERE WILL BE A BRIEF WINDOW FOR SOME STORMS NEAR THE SITE. OTHERWISE LIGHT SOUTHWEST WINDS WILL TURN TO THE NORTHWEST SUNDAY MORNING AS A SURFACE TROUGH MOVES THROUGH FROM THE WEST. BEHIND THE TROUGH WINDS WILL TURN CLOCKWISE TO THE NORTHEAST BY LATE AFTERNOON. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...DR LONG TERM...FS AVIATION...JTL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
612 PM CDT Sat May 2 2015 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Sunday) Issued at 404 PM CDT SAT MAY 2 2015 19Z water vapor imagery shows a shortwave moving across IA while 500MB profiler data suggests a more subtle wave has passed through eastern KS. Meanwhile a weak mid level ridge has propagated east and is centered over the TX big bend region with the mean westerlies remain north along the Canadian boarder. At the surface, high pressure over the southeast U.S. and low pressure in the northern plains has favored continued moisture advection with southerly winds bringing mid 50s dewpoints into the central plains. For tonight and Sunday, large scale forcing continues to be absent from the pattern. However models hint at the possibility for sporadic shower activity as early as this evening. The HRRR and RAP are the most optimistic in generating the shower activity. It appears the evening QPF is driven by warm air advection and isentropic upglide around 700MB. However RAP soundings suggest moisture will be rather limited in this layer. Because of this and the general subsidence behind the subtle wave, am not convinced showers will redevelop across central KS this evening. There are also signs that another subtle wave could come out of the CO Rockies late tonight and Sunday morning with some elevated light shower activity. There is a more organized signal in the isentropic surfaces of a shallow layer of lift Sunday morning. With bases at 10 KFT and little if any instability above this layer, am not sure any precip would amount to much and it end up being mainly virga. So have maintained a dry forecast for now, but there could be some light hit or miss precip with not much impact. Thanks for the collaboration EAX and ICT. Southerly winds and increased low level moisture should help keep lows tonight around 60 degrees. Increasing clouds from the west should also help keep overnight lows mild. With continued southerly winds, models continue the warming trend at 850MB with good mixing. Therefore have maintained highs in the lower and mid 80s. However if there is elevated shower activity, the forecast may be to warm for areas that remain cloudy. .LONG TERM...(Sunday Night through Saturday) Issued at 404 PM CDT SAT MAY 2 2015 Several opportunities for precipitation remain present through the forecast, with challenges on where and when the higher chances will be being the main challenge. The main trend in the nearer periods is the trend for a farther north settling of the cold front as it enters the area. Getting the front much past the northwest counties could be difficult with little/no additional frontogenesis from convection through Sunday afternoon along it and west to southwest flow over it. Have continued to taper precip chances, especially in the south into Monday night. There continues to be at least minor potential for severe weather and perhaps training storms near the boundary. NAM continues to look overdone with low level moisture and thus CAPE, but values near 2000 J/kg seem possible along the front with flow aloft nearly parallel to the boundary with slow cell motions and PWs near 1.5", more likely late Monday into Monday night. The front/effective front remains on track to mix back north Tuesday with some drier air moving in through the day, but attention then turns to the southwest as an upper wave remains on track to push slowly northeast through the Central Plains Tuesday night through Wednesday night. Models are fairly consistent with better upper forcing to the northwest and southeast, but also with widespread convection developing to the south-southwest and translating through late Tuesday night into Wednesday. Beyond Wednesday night, there continues to be indications of a weak boundary near to just west of the area with continued moisture availability into the area into Saturday. && .AVIATION...(For the 00Z TAFs through 00Z Sunday Evening) Issued at 611 PM CDT SAT MAY 2 2015 VFR conditions expected through the taf period. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Wolters LONG TERM...65 AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS TOPEKA KS
333 PM CDT Fri May 1 2015 .SHORT TERM...(This Evening through Saturday) Issued at 333 PM CDT FRI MAY 1 2015 19Z water vapor shows a ridge of high pressure centered over the AZ/NM boarder and broad cyclonic flow from the Gulf of AK through western Canada. Within this pattern, much of the shortwave activity remains along the Canadian boarder. At the surface, a ridge of high pressure was centered over the MS river valley with a weak trough of low pressure from northwest KS through the eastern Dakotas. For tonight and Saturday, there are two potential sources for forcing convection, and confidence in either one is rather so-so. The first is a possible convectively induced vort max (MCV) coming off the central Rockies this evening. The HRRR and RAP have been the most aggressive in holding precip together off the higher terrain and into the forecast area through Saturday morning. These solutions have also be to aggressive in this afternoon`s precip so I don`t know how much weight to put behind this idea with the GFS and NAM shearing out any MCV. At this point, have taken a wait and see approach for the convection to fully move off the mountains. Additionally the MCV may tend to move just southwest of the forecast area. The second forcing mechanism may end up being the low level jet and isentropic lift. The NAM and GFS seem to favor this, developing precip along the NEB state line and moving it into northern MO Saturday morning. However it appears the low level jet will be veered to the southwest with the stronger wind speeds to the west of the area. Additionally theta-e advection is marginal with the low level jet. The models do prog some isentropic lift over far northeast KS which may explain why they are generating precip. Nevertheless confidence is marginal since the low level jet itself is not very strong and moisture advection with the jet is weak. Have kept some 20 to 30 percent POPs across the northern counties through the morning to account for the possibility. Lows tonight should be a little more mild with readings remaining in the lower and mid 50s. Think skies are likely to remain at least partly cloudy with debris clouds spreading in from the west, helping to keep lows in the 50s. Models show some warm air advection through the day Saturday as low level flow remains southerly. Based on 850 temp progs and some insolation through the afternoon, think highs should warm into the upper 70s and lower 80s. .LONG TERM...(Saturday Night through Friday) Issued at 333 PM CDT FRI MAY 1 2015 Increasing low level southerly flow Saturday night into Sunday brings precipitable water values further above normal to near 1.5 inches. Main forcing mechanism approaches Sunday afternoon as a northern branch wave allows a cold front to settle south into the area, likely from southwest Kansas into east central Nebraska. Could see far western locations impacted late in the afternoon as storms could fire not far to the west-southwest, but chances increase in the next few periods as the front ceases its southerly push, between the northern and southern branches. Just how far the front gets is obviously a challenge and will be key for precip potential. Have tapered southern end of precip chances for Sunday night, with best mean chances Monday into Monday night until southerly flow returns to the northwest, ushering the front back north. At this point Tuesday appears the most likely dry period, with a modest but increasingly powerful upper wave rotating northeast into the Plains Tuesday night into Wednesday night. Expect most locations to see at least some precip in this period with deep south flow keeping available moisture plentiful. Beyond this, model differences increase for a much less confidence forecast, though a modified front could be in play with a still warm and moist airmass to support chance PoPs. As for thunderstorm severity, mid/upper flow is not very strong being between the northern and southern branches. With greater confidence in the late weekend/early next week boundary in the vicinity, there will of course be low level shear potential here with ML CAPE likely around 1500 J/kg. In the latter wetter period, the wave`s orientation keeps winds somewhat unidirectional with height, and instability specifics anything but certain with periodic precip quite likely. Expect highs to be generally near to a few degrees above normal, with main problem being depth/persistence of cloud/precip north of the front Monday to bring possibly cooler temps possible in northern areas. && .AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon) Issued at 1224 PM CDT FRI MAY 1 2015 Very limited forcing should keep any shower activity isolated through the period. Therefore will maintain a VFR forecast expecting only some mid level clouds lingering in the weak mid level flow. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Wolters LONG TERM...65 AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
220 PM MDT FRI MAY 1 2015 .SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY) ISSUED AT 150 PM MDT FRI MAY 1 2015 EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS BROAD RIDGE IN PALACE ACROSS THE SOUTHERN PLAINS WITH WESTERLY FLOW EXTENDING FROM THE GREAT BASIN ACROSS THE CENTRAL ROCKIES AND INTO THE CENTRAL PLAINS. A WEAK SHORTWAVE H5/H7 TROUGH IS IN THE PROCESS OF ROTATING THROUGH THE MEAN FLOW ACROSS THE CENTRAL ROCKIES WITH SHOWER/THUNDERSTORM DEVELOPMENT APPARENT ON UPSTREAM RADARS MOVING EAST OFF THE HIGHER TERRAIN. AT THE SURFACE LOW PRESSURE IS IN PLACE ACROSS THE CWA WITH A STATIONARY FRONT ALONG THE SOUTHEASTERN CORNER OF THE CWA EXTENDING SOUTH IN SOUTHEAST COLORADO. THIS AFTERNOON-TONIGHT...FOCUS CONTINUES TO BE ON POTENTIAL FOR THUNDERSTORMS DEVELOPING OVER THE CWA OR SPREADING EAST INTO THE CWA AS SHORTWAVE MOVES THROUGH THE REGION. WITH FRONT IN PLACE AND AIR MASS DESTABILIZING THERE IS SOME CONCERN THAT ISOLATED THUNDERSTORMS COULD DEVELOP AHEAD OF MAIN SHORTWAVE. HIGH CINH VALUES CURRENTLY IN PLACE ARE INHIBITING CONVECTION CURRENTLY OVER THE CWA DESPITE INCREASING INSTABILITY. AS SHORTWAVE MOVES EAST IT APPEARS THE CAP SHOULD WEAKEN ALLOWING FOR INCREASING CHANCES FROM THE WEST TO THE EAST. BEST PRECIP SIGNAL FROM RAP/HRRR CONTINUES TO BE IN THE SOUTHWEST PART OF THE CWA. 12Z GUIDANCE WAS RUNNING HIGH REGARDING CAPE VALUES MOST OF THE DAY...THOUGH AS SKIES HAVE CLEARED THE LATEST RAP ANALYSIS DOES SHOW 500-1000 KG/J ML CAPE DEVELOPING OVER THE REGION. SHEER IS NOT PARTICULARLY IMPRESSIVE AND AT THIS POINT SEVERE THREAT SEEMS TO BE LIMITED. ANY SHOWER/THUNDERSTORM ACTIVITY SHOULD QUICKLY DISSIPATE OR TRANSITION EAST OF THE CWA THROUGH LATE THIS EVENING AS A SHARP AREA OF SUBSIDENCE MOVES IN BEHIND EXITING SHORTWAVE. SATURDAY...VERY GOOD WAA IS ADVERTISED AND WITH CLEARING SKIES DURING THE FIRST PART OF THE DAY HIGHS SHOULD REACH THE 80S ACROSS THE CWA...POSSIBLY IN THE MID/UPPER 80S IN THE EAST. THE NEXT SHORTWAVE IS SHOWN TO APPROACH THE REGION FROM THE CENTRAL ROCKIES LATE AFTERNOON WITH THUNDERSTORM INITIATION NEAR SURFACE TROUGH ALONG CO/KS BORDER POSSIBLE AFTER 21Z...OTHERWISE BETTER CHANCES ARRIVE LATER IN THE EVENING. MODELS ARE SHOWING VERY UNSTABLE AIR BUILDING OVER THE REGION WITH NAM ADVERTISING 1500-2500 J/KG OF ML CAPE BY LATE AFTERNOON. SHEER IS A LITTLE BETTER THAN TODAY WITH EFFECTIVE SHEER IN EXCESS OF 35KT. WITH THIS IN MIND ANY THUNDERSTORMS THAT DEVELOP LATE TUESDAY AFTERNOON COULD POTENTIALLY ORGANIZE AND BECOME SEVERE. WITH MINIMAL LOW LEVEL SHEER LARGE HAIL/DAMAGING WIND CONTINUE TO BE MAIN CONCERNS. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 218 PM MDT FRI MAY 1 2015 A FLATTENED RIDGE WILL BE OVER THE SOUTHERN PLAINS THROUGH SUNDAY NIGHT WITH WESTERLY FLOW OVER THE CENTRAL PLAINS. THE SOUTHERN PLAINS RIDGE WILL SHIFT EASTWARD MONDAY WITH SOUTHWEST FLOW OVER THE CENTRAL PLAINS. A SURFACE TROUGH OVER EASTERN COLORADO WILL MIGRATE SLOWLY EAST ACROSS NORTHWEST KANSAS THROUGH SUNDAY NIGHT. SURFACE HIGH PRESSURE WILL MOVE INTO THE REGION MONDAY BEHIND THE EXITING TROUGH. A SHORTWAVE MOVES ACROSS THE FA SATURDAY EVENING WITH SUBSIDENCE INDICATED AFTER 06Z TUESDAY AS THE SHORTWAVE SLIDES SOUTHEAST OUT OF THE AREA. H8-7 LAYER MEAN RH IS NOT IDEAL SO WILL KEEP POPS AT SLIGHT CHANCE. CAPE VALUES UP TO 1000 J/KG ARE EXPECTED WITH AN AREA OF 35 KTS SHEAR OVER NORTHEAST COLORADO. A FEW ISOLATED MARGINALLY SEVERE STORMS ARE POSSIBLE. SUBSIDENCE CONTINUES THROUGH SUNDAY MORNING AND INTO THE AFTERNOON. THE NEXT SHORTWAVE SHOULD IMPACT EASTERN COLORADO BY MID TO LATE AFTERNOON. PLAN TO GO WITH CHANCE POPS OVER WESTERN PORTIONS OF EASTERN COLORADO AND ALSO NEAR THE TROUGH AXIS IN THE SOUTHEASTERN FA. GOOD DYNAMICS AND MOISTURE MOVE ACROSS THE FA SUNDAY NIGHT SO WILL GO WITH HIGHER CHANCE POPS ESPECIALLY IN THE WEST DURING THE EVENING WHERE STORMS SHOULD ALREADY BE IN PROGRESS. HIGH CHANCE POPS WILL CONTINUE AFTER 06Z MONDAY AS THE SHORTWAVE IMPACTS THE ENTIRE AREA. MONDAY DOES NOT APPEAR TO BE AS FAVORABLE FOR PRECIPITATION AS HIGH PRESSURE BUILDING IN FROM THE NORTH PUSHES THE SURFACE BOUNDARY FURTHER SOUTH. FURTHERMORE, THE MAIN SURFACE LOW IS OVER SOUTHERN CALIFORNIA, DYNAMICS ARE MORE UNCERTAIN. CONSEQUENTLY LOWERED POPS SOME BUT STILL KEPT CHANCE POPS OVER THE AREA MONDAY AFTERNOON. MIN TEMPERATURES SHOULD VARY FROM THE UPPER 40S TO THE LOWER 50S SATURDAY AND SUNDAY NIGHTS. MAX TEMPERATURES SHOULD RISE TO THE LOWER TO MID 80S SUNDAY AND THEN COOL TO THE MID 60S TO AROUND 70 MONDAY. IN THE EXTENDED...(TUESDAY THROUGH FRIDAY)...ACTIVE WEATHER IS EXPECTED FOR THIS PART OF THE FORECAST. AN UPPER LEVEL TROUGH OVER THE SW CONUS WILL MOVE NORTHEAST AND PHASE INTO A TROUGH OVER THE PACIFIC NORTHWEST. NUMEROUS SHORTWAVES WILL MOVE THROUGH THE FLOW AND ACROSS THE CENTRAL PLAINS. THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE FA ON A DAILY BASIS THROUGH FRIDAY. MIN TEMPERATURES WILL COOL TO THE UPPER 40S AND LOWER 50S. MAX TEMPERATURES SHOULD RANGE FROM 65 TO 70 TUESDAY WARMING TO THE 70S WEDNESDAY THROUGH FRIDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1125 AM MDT FRI MAY 1 2015 VFR CONDITIONS CURRENTLY EXPECTED TO PREVAIL AT BOTH KGLD AND KMCK. THERE IS SOME INDICATION OF INCREASING BOUNDARY LAYER MOISTURE AND THE POSSIBILITY FOR STRATUS DEVELOPMENT LATE...HOWEVER THIS WILL BE HEAVILY DEPENDENT ON POSITION OF SURFACE FRONT AND COVERAGE OF SHOWERS/THUNDERSTORMS. AT THIS TIME THERE WAS TOO MUCH UNCERTAINTY TO INCLUDE LOWER CONDITIONS IN THE TAF. I INCLUDED A VCSH AT KGLD AS BETTER PRECIP SIGNAL INDICATES SCATTERED COVERAGE FROM THE WEST AND LESS COVERAGE IN THE NORTHEAST NEAR KMCK. MODELS APPEAR TO BE OVERDONE REGARDING INSTABILITY AND COVERAGE OF THUNDERSTORMS IS UNCERTAIN WITH SHOWERS POSSIBLY FAVORED THIS AFTERNOON/EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...FS AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
151 PM MDT FRI MAY 1 2015 .SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY) ISSUED AT 150 PM MDT FRI MAY 1 2015 EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS BROAD RIDGE IN PALACE ACROSS THE SOUTHERN PLAINS WITH WESTERLY FLOW EXTENDING FROM THE GREAT BASIN ACROSS THE CENTRAL ROCKIES AND INTO THE CENTRAL PLAINS. A WEAK SHORTWAVE H5/H7 TROUGH IS IN THE PROCESS OF ROTATING THROUGH THE MEAN FLOW ACROSS THE CENTRAL ROCKIES WITH SHOWER/THUNDERSTORM DEVELOPMENT APPARENT ON UPSTREAM RADARS MOVING EAST OFF THE HIGHER TERRAIN. AT THE SURFACE LOW PRESSURE IS IN PLACE ACROSS THE CWA WITH A STATIONARY FRONT ALONG THE SOUTHEASTERN CORNER OF THE CWA EXTENDING SOUTH IN SOUTHEAST COLORADO. THIS AFTERNOON-TONIGHT...FOCUS CONTINUES TO BE ON POTENTIAL FOR THUNDERSTORMS DEVELOPING OVER THE CWA OR SPREADING EAST INTO THE CWA AS SHORTWAVE MOVES THROUGH THE REGION. WITH FRONT IN PLACE AND AIR MASS DESTABILIZING THERE IS SOME CONCERN THAT ISOLATED THUNDERSTORMS COULD DEVELOP AHEAD OF MAIN SHORTWAVE. HIGH CINH VALUES CURRENTLY IN PLACE ARE INHIBITING CONVECTION CURRENTLY OVER THE CWA DESPITE INCREASING INSTABILITY. AS SHORTWAVE MOVES EAST IT APPEARS THE CAP SHOULD WEAKEN ALLOWING FOR INCREASING CHANCES FROM THE WEST TO THE EAST. BEST PRECIP SIGNAL FROM RAP/HRRR CONTINUES TO BE IN THE SOUTHWEST PART OF THE CWA. 12Z GUIDANCE WAS RUNNING HIGH REGARDING CAPE VALUES MOST OF THE DAY...THOUGH AS SKIES HAVE CLEARED THE LATEST RAP ANALYSIS DOES SHOW 500-1000 KG/J ML CAPE DEVELOPING OVER THE REGION. SHEER IS NOT PARTICULARLY IMPRESSIVE AND AT THIS POINT SEVERE THREAT SEEMS TO BE LIMITED. ANY SHOWER/THUNDERSTORM ACTIVITY SHOULD QUICKLY DISSIPATE OR TRANSITION EAST OF THE CWA THROUGH LATE THIS EVENING AS A SHARP AREA OF SUBSIDENCE MOVES IN BEHIND EXITING SHORTWAVE. TUESDAY...VERY GOOD WAA IS ADVERTISED AND WITH CLEARING SKIES DURING THE FIRST PART OF THE DAY HIGHS SHOULD REACH THE 80S ACROSS THE CWA...POSSIBLY IN THE MID/UPPER 80S IN THE EAST. THE NEXT SHORTWAVE IS SHOWN TO APPROACH THE REGION FROM THE CENTRAL ROCKIES LATE AFTERNOON WITH THUNDERSTORM INITIATION NEAR SURFACE TROUGH ALONG CO/KS BORDER POSSIBLE AFTER 21Z...OTHERWISE BETTER CHANCES ARRIVE LATER IN THE EVENING. MODELS ARE SHOWING VERY UNSTABLE AIR BUILDING OVER THE REGION WITH NAM ADVERTISING 1500-2500 J/KG OF ML CAPE BY LATE AFTERNOON. SHEER IS A LITTLE BETTER THAN TODAY WITH EFFECTIVE SHEER IN EXCESS OF 35KT. WITH THIS IN MIND ANY THUNDERSTORMS THAT DEVELOP LATE TUESDAY AFTERNOON COULD POTENTIALLY ORGANIZE AND BECOME SEVERE. WITH MINIMAL LOW LEVEL SHEER LARGE HAIL/DAMAGING WIND CONTINUE TO BE MAIN CONCERNS. .LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 348 AM MDT FRI MAY 1 2015 AN UPPER LEVEL LOW SITUATED OVER THE PACIFIC NORTHWEST WILL SLOWLY MOVE SOUTHEAST INTO THE INTERMOUNTAIN WEST MONDAY THROUGH WEDNESDAY. SEVERAL SHORTWAVES WILL FORM ALONG THE SOUTHERN AXIS OF THIS LOW AND MOVE ACROSS THE REGION NEXT WEEK. A POTENT AREA OF LOW PRESSURE WILL FORM ON MONDAY IN THE SOUTHWEST US AND MOVE NORTHWARD INTO SOUTHERN COLORADO ON TUESDAY. LOOKING AT THE 500MB AND 700MB HEIGHT FIELDS... A NEGATIVE TROUGH WILL TAKE SHAPE AS WE HEAD INTO LATE MONDAY NIGHT AND TUESDAY MORNING AND AMPLIFY OVER THE COURSE OF THE DAY. CAPE AND OMEGA VALUES TUESDAY MORNING WILL BE HIGHEST IN THE SOUTHERN PORTIONS OF THE CWA AND WILL SPREAD NORTHWARD THROUGH THE DAY HOWEVER CAPE VALUES ARE RELATIVELY MODEST AT THIS POINT. SHEAR IS EXPECTED TO INCREASE AS THE DAY PROGRESSES AS WELL. THERE IS A POTENTIAL FOR ISOLATED SEVERE THUNDERSTORMS ON BOTH MONDAY AND TUESDAY AS THIS SYSTEM SLOWLY LIFTS NORTHWARD. THERE WILL BE ENOUGH MOISTURE AND INSTABILITY ON WEDNESDAY TO ALLOW THE CHANCE FOR AT LEAST ISOLATED TO SCATTERED THUNDERSTORMS AS THE DISTURBANCE CONTINUES TO INFLUENCE THE REGION... CONTINUING NORTHWARD THROUGH THE DAY. GIVEN THE PRESENCE OF RELATIVELY HIGH SHEAR... MARGINAL CAPE AND DCAPE... AND HIGH PW VALUES WE COULD SEE LOCALLY HEAVY RAIN... SEVERE HAIL AND GUSTY WINDS. THERE IS STILL SOME UNCERTAINTY IN THE FORECAST HOWEVER BRIEF TORNADOES CANNOT BE RULED OUT ESPECIALLY DURING THE AFTERNOON AND EARLY EVENING HOURS MAINLY ON MONDAY AND TUESDAY AS SHEAR BEGINS TO TAPER OFF ON WEDNESDAY. EARLY INDICATIONS SHOW THE POSSIBILITY OF SLIGHT RAIN CHANCES AS WE HEAD INTO THURSDAY AS THE MAIN AREA OF LOW PRESSURE LOCATED OVER THE PACIFIC NORTHWEST CONTINUES TO PUSH SHORTWAVES ACROSS THE REGION FROM SOUTHWEST TO NORTHEAST. AT THIS POINT POP REMAINS IN THE 20-30 PERCENT RANGE HOWEVER THERE IS MUCH DISAGREEMENT BETWEEN THE GLOBAL MODELS AT THIS TIME WITH THE GFS CONTINUING THE TREND OF BEING MORE AGGRESSIVE WITH BOTH MOISTURE AVAILABILITY AND TROUGH STRENGTH. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1125 AM MDT FRI MAY 1 2015 VFR CONDITIONS CURRENTLY EXPECTED TO PREVAIL AT BOTH KGLD AND KMCK. THERE IS SOME INDICATION OF INCREASING BOUNDARY LAYER MOISTURE AND THE POSSIBILITY FOR STRATUS DEVELOPMENT LATE...HOWEVER THIS WILL BE HEAVILY DEPENDENT ON POSITION OF SURFACE FRONT AND COVERAGE OF SHOWERS/THUNDERSTORMS. AT THIS TIME THERE WAS TOO MUCH UNCERTAINTY TO INCLUDE LOWER CONDITIONS IN THE TAF. I INCLUDED A VCSH AT KGLD AS BETTER PRECIP SIGNAL INDICATES SCATTERED COVERAGE FROM THE WEST AND LESS COVERAGE IN THE NORTHEAST NEAR KMCK. MODELS APPEAR TO BE OVERDONE REGARDING INSTABILITY AND COVERAGE OF THUNDERSTORMS IS UNCERTAIN WITH SHOWERS POSSIBLY FAVORED THIS AFTERNOON/EVENING. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...TML AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1224 PM CDT Fri May 1 2015 .UPDATE... Issued at 1224 PM CDT FRI MAY 1 2015 The light shower activity seems to be having a hard time holding together against the dry air seen in this morning`s 12Z RAOB. With the water vapor imagery showing the upper shortwave trough well north of the area, may remove POPs from this afternoon and this evening all together. Will also trend afternoon highs a little warmer, though based on RAP and GFS forecast soundings think temps will remain below 80 degrees this afternoon. Tonight`s precip chances appear to be dependent on whether a convectively induced vort max moves out from the central Rockies this evening. Only the high resolution models seem to think this is possible. Still have some things to look at, but I do not foresee precip chances to be very high. && .SHORT TERM...(Today and Tonight) Issued at 332 AM CDT FRI MAY 1 2015 Water vapor loop shows nearly zonal stronger flow aloft across the northern Rockies and northern Plains states with a well-defined shortwave trough from the eastern Dakotas into northwest MN. A band of showers is associated with lift ahead of upper trough moving through western MN trailing back into northeast Nebraska at this time. Forcing associated with this system should stay well to north of forecast area today. However, regional radar loops show showers and isolated thunderstorms occurring with trailing cold front/trough from central Nebraska into northwest KS. There is some disagreement among models but NAM, RAP and HRRR show remnants of this high-based precip making it into north central KS by early afternoon and then moving across far northeastern KS during the rest of the afternoon. While confidence is not high in measurable precip with this activity, have continued slight chance POPs for far northern counties this afternoon. Something similar could happen again tonight with developing showers and thunderstorms over western Nebraska, which is forecast by some models to persist and move into far northern parts of our area tonight. Once again, without a stronger upper level system or recognizable front coming through, this will be a low chance event, with slightly better chances to our north. Considerable mid and high level cloudiness today could make high temp forecast tricky. Still think enough sunshine will get through to allow highs to reach the mid to upper 70s. .LONG TERM...(Saturday through Thursday) Issued at 332 AM CDT FRI MAY 1 2015 By Saturday, fairly zonal mid-level flow will be in place with surface high pressure prevailing across the southeastern U.S. and surface low pressure extending along the High Plains. Models continue to show a few weak embedded shortwaves developing within the zonal flow on Saturday as a vort max skims just north of the CWA. However, with no surface feature to help further support these waves and with model soundings showing a decent amount of dry air in the low levels, have only slight chance PoPs in across far northern and far northeast Kansas Saturday morning with dry conditions by the afternoon as the associated vort max lifts to the northeast. With the above-mentioned surface pattern in place, southerly surface winds should boost high temperatures into the upper 70s/low 80s. Have gone with a dry forecast Saturday afternoon through Sunday before the next system moves into the region, which will be the beginning of a wet stretch of weather that looks to extend through the latter part of next week. Models show the surface low advancing eastward toward the CWA on Sunday, resulting in an increased pressure gradient, breezy southerly winds, and thus good warm air advection that should support the warmest temperatures of the week with highs reaching into the low/mid 80s. Precipitation chances will increase Sunday night through Monday as a cold front slowly sags southeastward across the CWA. However, models show the front stalling out over the southern portions of the forecast area and pivoting over the area before lifting northward as a warm front to just north of the KS/NE border on Tuesday. As a result, have chance to likely PoPs for thunderstorms from Sunday night through Monday night. Even though the cap looks to significantly weaken through the day on Monday and the amount of available instability is modest, wind shear looks to be fairly weak across the region, thus limiting the potential for strong storms. With the warm front lifting into Nebraska, ECMWF/GEM actually keep Tuesday predominantly dry while the GFS tries to hold on to some scattered precipitation chances, so have lowered PoPs. However, thunderstorm chances increase once again by Tuesday night as a mid-level trough becomes negatively tilted and begins to lift northward into the central U.S. This approaching trough will not only provide additional forcing to support thunderstorm development, but also push another area of surface low pressure into the area by mid week. However, there are still model discrepancies in the evolution of the mid-level trough as it lifts northward and in the timing of the passage of the cold front, which should track eastward across the area sometime during the latter part of the week. As a result, there is uncertainty still with when this system will exit the region. At this time, have chance to likely PoPs in from Tuesday night through Thursday night. The best potential for some more-organized storms looks to be during the mid to late week period in which the combination of the surface low pressure system and mid-level trough should provide decent forcing along with decent instability and some slightly improved wind shear. At this time, temperatures next week look to be fairly steady with highs in the 70s and lows in the 50s to low 60s. && .AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon) Issued at 1224 PM CDT FRI MAY 1 2015 Very limited forcing should keep any shower activity isolated through the period. Therefore will maintain a VFR forecast expecting only some mid level clouds lingering in the weak mid level flow. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...Wolters SHORT TERM...GDP LONG TERM...Hennecke AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
619 AM CDT Fri May 1 2015 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 332 AM CDT FRI MAY 1 2015 Water vapor loop shows nearly zonal stronger flow aloft across the northern Rockies and northern Plains states with a well-defined shortwave trough from the eastern Dakotas into northwest MN. A band of showers is associated with lift ahead of upper trough moving through western MN trailing back into northeast Nebraska at this time. Forcing associated with this system should stay well to north of forecast area today. However, regional radar loops show showers and isolated thunderstorms occurring with trailing cold front/trough from central Nebraska into northwest KS. There is some disagreement among models but NAM, RAP and HRRR show remnants of this high-based precip making it into north central KS by early afternoon and then moving across far northeastern KS during the rest of the afternoon. While confidence is not high in measurable precip with this activity, have continued slight chance POPs for far northern counties this afternoon. Something similar could happen again tonight with developing showers and thunderstorms over western Nebraska, which is forecast by some models to persist and move into far northern parts of our area tonight. Once again, without a stronger upper level system or recognizable front coming through, this will be a low chance event, with slightly better chances to our north. Considerable mid and high level cloudiness today could make high temp forecast tricky. Still think enough sunshine will get through to allow highs to reach the mid to upper 70s. .LONG TERM...(Saturday through Thursday) Issued at 332 AM CDT FRI MAY 1 2015 By Saturday, fairly zonal mid-level flow will be in place with surface high pressure prevailing across the southeastern U.S. and surface low pressure extending along the High Plains. Models continue to show a few weak embedded shortwaves developing within the zonal flow on Saturday as a vort max skims just north of the CWA. However, with no surface feature to help further support these waves and with model soundings showing a decent amount of dry air in the low levels, have only slight chance PoPs in across far northern and far northeast Kansas Saturday morning with dry conditions by the afternoon as the associated vort max lifts to the northeast. With the above-mentioned surface pattern in place, southerly surface winds should boost high temperatures into the upper 70s/low 80s. Have gone with a dry forecast Saturday afternoon through Sunday before the next system moves into the region, which will be the beginning of a wet stretch of weather that looks to extend through the latter part of next week. Models show the surface low advancing eastward toward the CWA on Sunday, resulting in an increased pressure gradient, breezy southerly winds, and thus good warm air advection that should support the warmest temperatures of the week with highs reaching into the low/mid 80s. Precipitation chances will increase Sunday night through Monday as a cold front slowly sags southeastward across the CWA. However, models show the front stalling out over the southern portions of the forecast area and pivoting over the area before lifting northward as a warm front to just north of the KS/NE border on Tuesday. As a result, have chance to likely PoPs for thunderstorms from Sunday night through Monday night. Even though the cap looks to significantly weaken through the day on Monday and the amount of available instability is modest, wind shear looks to be fairly weak across the region, thus limiting the potential for strong storms. With the warm front lifting into Nebraska, ECMWF/GEM actually keep Tuesday predominantly dry while the GFS tries to hold on to some scattered precipitation chances, so have lowered PoPs. However, thunderstorm chances increase once again by Tuesday night as a mid-level trough becomes negatively tilted and begins to lift northward into the central U.S. This approaching trough will not only provide additional forcing to support thunderstorm development, but also push another area of surface low pressure into the area by mid week. However, there are still model discrepancies in the evolution of the mid-level trough as it lifts northward and in the timing of the passage of the cold front, which should track eastward across the area sometime during the latter part of the week. As a result, there is uncertainty still with when this system will exit the region. At this time, have chance to likely PoPs in from Tuesday night through Thursday night. The best potential for some more-organized storms looks to be during the mid to late week period in which the combination of the surface low pressure system and mid-level trough should provide decent forcing along with decent instability and some slightly improved wind shear. At this time, temperatures next week look to be fairly steady with highs in the 70s and lows in the 50s to low 60s. && .AVIATION...(For the 12Z TAFs through 12Z Saturday Morning) Issued at 613 AM CDT FRI MAY 1 2015 Expect considerably high level cloudiness today. But clouds should be at 10,000 ft and above. A very weak upper system could affect area tonight and isolated showers are a possibility. However, coverage is expected to be too isolated to mention in TAFs. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GDP LONG TERM...Hennecke AVIATION...GDP
AREA FORECAST DISCUSSION
NWS TOPEKA KS
355 AM CDT Fri May 1 2015 .SHORT TERM...(Today and Tonight) Issued at 332 AM CDT FRI MAY 1 2015 Water vapor loop shows nearly zonal stronger flow aloft across the northern Rockies and northern Plains states with a well-defined shortwave trough from the eastern Dakotas into northwest MN. A band of showers is associated with lift ahead of upper trough moving through western MN trailing back into northeast Nebraska at this time. Forcing associated with this system should stay well to north of forecast area today. However, regional radar loops show showers and isolated thunderstorms occurring with trailing cold front/trough from central Nebraska into northwest KS. There is some disagreement among models but NAM, RAP and HRRR show remnants of this high-based precip making it into north central KS by early afternoon and then moving across far northeastern KS during the rest of the afternoon. While confidence is not high in measurable precip with this activity, have continued slight chance POPs for far northern counties this afternoon. Something similar could happen again tonight with developing showers and thunderstorms over western Nebraska, which is forecast by some models to persist and move into far northern parts of our area tonight. Once again, without a stronger upper level system or recognizable front coming through, this will be a low chance event, with slightly better chances to our north. Considerable mid and high level cloudiness today could make high temp forecast tricky. Still think enough sunshine will get through to allow highs to reach the mid to upper 70s. .LONG TERM...(Saturday through Thursday) Issued at 332 AM CDT FRI MAY 1 2015 By Saturday, fairly zonal mid-level flow will be in place with surface high pressure prevailing across the southeastern U.S. and surface low pressure extending along the High Plains. Models continue to show a few weak embedded shortwaves developing within the zonal flow on Saturday as a vort max skims just north of the CWA. However, with no surface feature to help further support these waves and with model soundings showing a decent amount of dry air in the low levels, have only slight chance PoPs in across far northern and far northeast Kansas Saturday morning with dry conditions by the afternoon as the associated vort max lifts to the northeast. With the above-mentioned surface pattern in place, southerly surface winds should boost high temperatures into the upper 70s/low 80s. Have gone with a dry forecast Saturday afternoon through Sunday before the next system moves into the region, which will be the beginning of a wet stretch of weather that looks to extend through the latter part of next week. Models show the surface low advancing eastward toward the CWA on Sunday, resulting in an increased pressure gradient, breezy southerly winds, and thus good warm air advection that should support the warmest temperatures of the week with highs reaching into the low/mid 80s. Precipitation chances will increase Sunday night through Monday as a cold front slowly sags southeastward across the CWA. However, models show the front stalling out over the southern portions of the forecast area and pivoting over the area before lifting northward as a warm front to just north of the KS/NE border on Tuesday. As a result, have chance to likely PoPs for thunderstorms from Sunday night through Monday night. Even though the cap looks to significantly weaken through the day on Monday and the amount of available instability is modest, wind shear looks to be fairly weak across the region, thus limiting the potential for strong storms. With the warm front lifting into Nebraska, ECMWF/GEM actually keep Tuesday predominantly dry while the GFS tries to hold on to some scattered precipitation chances, so have lowered PoPs. However, thunderstorm chances increase once again by Tuesday night as a mid-level trough becomes negatively tilted and begins to lift northward into the central U.S. This approaching trough will not only provide additional forcing to support thunderstorm development, but also push another area of surface low pressure into the area by mid week. However, there are still model discrepancies in the evolution of the mid-level trough as it lifts northward and in the timing of the passage of the cold front, which should track eastward across the area sometime during the latter part of the week. As a result, there is uncertainty still with when this system will exit the region. At this time, have chance to likely PoPs in from Tuesday night through Thursday night. The best potential for some more-organized storms looks to be during the mid to late week period in which the combination of the surface low pressure system and mid-level trough should provide decent forcing along with decent instability and some slightly improved wind shear. At this time, temperatures next week look to be fairly steady with highs in the 70s and lows in the 50s to low 60s. && .AVIATION...(For the 06Z TAFs through 06Z Friday Night) Issued at 1148 PM CDT THU APR 30 2015 Expect VFR conditions through the next 24 hours. Light east to southeast winds this morning will become southerly after 14Z, but will remain below 10 KTS. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...GDP LONG TERM...Hennecke AVIATION...Gargan
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
110 AM EDT Fri May 1 2015 ...Updated Aviation Discussion... .SHORT TERM (Now through Friday Night)... Issued at 305 PM EDT Thu Apr 30 2015 Unseasonably cold mid-level low continues to move southward and was centered over west-central IN at mid-afternoon. The low will propagate over central and eastern KY this evening. As expected, cold mid-level temperatures combined with modest low-level heating have steepened lapse rates and facilitated development of scattered to numerous showers and a few thunderstorms. A few cells have produced pea size hail, brief wind gusts up to 40 mph, and some lightning strikes. Currently, radar data shows better precipitation coverage over east-central KY including the Lexington area, and approaching the eastern half of south-central IN from the north. Latest HRRR model reflectivity forecast captures these areas reasonably well. It maintains the southern IN cells, moving them south-southeast into north-central and east-central KY late this afternoon. Other pop up cells could occur elsewhere as well. Thus, will maintain highest coverage/percentage of precipitation east of Interstate 65, especially over east-central KY. Rainfall intensity and coverage will slowly diminish this evening with loss of daytime heating and as the upper low moves eastward. Overnight, dry weather is expected with some clouds remaining over the east, with fewer clouds over western parts of our forecast area. There could be patchy fog near daybreak over parts of east-central KY. It will be chilly, with lows Friday morning in the upper 30s and lower 40s in many areas. On Friday, the mid-level low will continue pulling eastward away from our area. There could be some residual clouds over the east half of our forecast area, but dry weather is expected. Temperatures will begin a warming trend that will last through the weekend and into next week. Expect highs Friday afternoon in the mid 60s to lower 70s. .LONG TERM (Saturday through Thursday)... Issued at 315 PM EDT Thu Apr 30 2015 Saturday - Saturday Night... NW flow aloft will dominate the pattern, meanwhile surface high pressure will be in place. Models have been consistent now for the past several runs in depicting a shortwave embedded in the flow traversing the area on Saturday. Will continue to keep the forecast dry as this feature looks starved of moisture. Instead, will depict an increase in cloud cover through the afternoon, although still expect partly sunny skies. With plenty of peaks at the sun, will call for temps mostly in the mid 70s. A few spots that see more clouds may stay in the low 70s. Dry conditions will continue into Saturday night where weak and progressive upper ridging slides over the Ohio River Valley. Meanwhile, surface high pressure remains at the surface. Given good radiational cooling conditions, lows will still slide into the upper 40s and low 50s. Sunday - Thursday... Low amplitude NW flow aloft will transition to upper ridging over the CWA to end the weekend and start the new work week. This ridge is then expected to hold over the area through the end of the week. A frontal boundary that looks to stall nearly parallel to the upper flow should stay well to the north across the southern Great Lakes. This pattern will result in continued dry conditions and temperatures rising above normal for this time of year. Can`t rule out an extremely isolated shower or t-storm at some point through the week, however lack of a trigger and mid level subsidence inversion is enough to keep a dry forecast going. Have nudged temperatures up around MEX guidance given the warmer pattern, and wouldn`t be surprised if they end up a couple of degrees warmer. This will result in forecast temperatures more solidly in the low and mid 80s Tue-Thur. Will go with upper 70s to around 80 for Sunday, and around 80 for Monday. Lows each night should mostly be in the 50s, with the usual warm spots likely around 60. && .AVIATION (06Z TAF Update)... Updated at 109 AM EDT Fri May 1 2015 High pressure building in from the north should keep the TAFs VFR during this forecast period. There`s a small chance of some MVFR BR at BWG early this morning, but right now it looks like dew point depressions will remain large enough to warrant a VFR TAF. Also, there is a small chance of an MVFR ceiling at LEX in the hours before and after sunrise, but it`s looking like the best chances for low ceilings will stay just east of the terminal. Lastly, there is some concern for MVFR BR at LEX, but with expected cloud cover and continued north wind, will not include it in the TAF at this time. && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ Short Term........TWF Long Term.........BJS Aviation..........13
AREA FORECAST DISCUSSION
NWS DULUTH MN
940 PM CDT SAT MAY 2 2015 .UPDATE... ISSUED AT 940 PM CDT SAT MAY 2 2015 THE DECAYING LINE OF SHOWERS AND THUNDERSTORMS CONTINUED TO DIMINISH AS IT MOVES EASTWARD INTO THE CWA DURING THE EVENING. SOME GUSTY WINDS REMAINED ACROSS AREAS WEST OF THE BRAINERD LAKES REGION...ALTHOUGH WIND SPEED VALUES HAVE DECREASED CONSIDERABLY. COULD STILL BE SOME GUSTY WINDS...MAINLY ACROSS THE BRAINERD LAKES AND LEECH LAKE AREAS DURING THE REMAINDER OF THE EVENING. OVERALL...THINK THINGS WILL QUIET DOWN FURTHER AS THE NIGHT WEARS ON...PER HRRR AND RAP SIMULATED REFLECTIVITY AS WELL AS THE 4KM NMM WRF. WILL CONTINUE ISOLATED TO SCATTERED MENTION FOR MUCH OF THE AREA AS THE NIGHT WEARS ON. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 324 PM CDT SAT MAY 2 2015 A SFC LOW WAS MOVING INTO NW ONTARIO AT 19Z WITH A TRAILING COLD FRONT SWWD INTO WESTERN ND. A SFC TROF WAS ALSO FOUND IN CENTRAL ND. THUNDERSTORMS WERE FIRING AHEAD OF THIS TROF IN THE VCNTY OF EMBEDDED PIECES OF ENERGY IN FAST ZONAL FLOW ALOFT. AN AREA OF SFC FGEN WAS ALSO CO-LOCATED WITH THE STORMS. EXPECT THIS LINE OF STORMS TO REACH NW MN BY 21Z. THE STORMS WILL CONTINUE TO MOVE EWD AND REACH THE NW CORNER OF KOOCHICHING COUNTY BY 01Z. HOWEVER...IT IS AT THIS POINT IN TIME WHEN THE STORMS BEGIN TO ENCOUNTER DRIER AIR THAT HAS BEEN CAMPED OUT OVER THE FORECAST AREA. LATEST SHORT TERM HIRES MODELS INCLUDING THE HRRR AND RAP SHOW THIS TREND AS WELL. AS THIS INITIAL ROUND OF STORMS DISSOLVES...THE NEXT ROUND WILL BEGIN TO DEVELOP OVER THE WESTERN HALF OF THE AREA AROUND 06Z AS THE SFC FRONT MAKES PROGRESS EWD INTO THE REGION. A LOW LEVEL INVERSION SEEN ON AREA FORECAST SOUNDINGS INDICATE THAT THESE STORMS WILL BE ELEVATED IN NATURE. ON SUNDAY...THE FRONT WILL PROGRESS SLOWLY EWD THROUGH THE DAY. SOME WEAK THUNDERSTORMS WILL BE AROUND IN THE MORNING AS A THERMAL RIDGE AXIS IS OVER THE REGION AND INSTABILITY IS WEAK. BY AFTERNOON...THE FRONT PUSHES INTO NW WI WITH MAX HEATING...STORMS WILL BECOME A BIT MORE VIGOROUS...AND BORDER ON SEVERE. SBCAPE INCREASES TO NEAR 3000 J/KG AND LI/S TO -8C PER FORECAST SOUNDINGS. SHOULD SEE SOME STORMS NEAR SEVERE WITH LARGE HAIL AND BRIEF HEAVY RAIN AS PWATS ARE 1 TO 1.25 INCHES. MODELS COME INTO AGREEMENT WITH THIS SOLUTION AND HAVE ROBUST QPF BY 00Z MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 324 PM CDT SAT MAY 2 2015 SUNDAY EVENING THE COLD FRONT MOVES SOUTHEAST AWAY FROM THE AREA...AND WHILE I HAVE MAINTAINED SOME POPS FOR THE EVENING HOURS...EXPECT THEY WILL ONLY BE ONGOING AT THE VERY BEGINNING OF THE PERIOD AND EXIT QUICKLY DURING THE EVENING. A COOLER AND DRIER AIRMASS MOVES INTO THE AREA AFTER MIDNIGHT AND WILL LINGER THROUGH MONDAY AND MONDAY NIGHT. LOWS SUNDAY NIGHT AND MONDAY NIGHT TO FALL INTO THE MID 30S TO MID 40S FOR MUCH OF THE AREA...WITH HIGHS MONDAY BACK IN THE 60S TO AROUND 70. THE UPPER LEVEL PATTERN IS EXPECTED TO SHIFT TO A LONGWAVE TROUGH OVER THE WEST COAST AND ROCKIES...WITH WEAK RIDGING TO ZONAL FLOW OVER THE EASTERN CONUS. THIS TROUGHINESS TO OUR WEST IS GOING TO SENT A STRONG...SLOW MOVING UPPER LEVEL LOW SHORTWAVE ACROSS THE UPPER MIDWEST TUESDAY THROUGH FRIDAY...WITH SOME FAIRLY HIGH CHANCES FOR PRECIPITATION DURING THE PERIOD. TEMPERATURES WILL ALSO BE ABOVE NORMAL WITH HIGHS IN THE 70S EVEN WITH INCREASED CLOUD COVER AND PRECIPITATION. THIS SYSTEM TO MOVE OFF TO THE NORTHEAST BY SATURDAY...BUT THE UPPER LEVEL PATTERN OF A TROUGH OUT WEST REMAINS WITH WARM AIR STILL BEING FUNNELED IN OUR DIRECTION AND SOME LINGERING PRECIPITATION CHANCES INTO THE WEEKEND. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 735 PM CDT SAT MAY 2 2015 A COLD FRONT HAS TRIGGERED SHOWERS AND THUNDERSTORMS IN EASTERN NORTH DAKOTA AND IN PORTIONS OF FAR NORTHWEST MINNESOTA. THE FRONT WILL CONTINUE MOVING INTO NORTHWEST MINNESOTA TONIGHT. THE LATEST RADAR TRENDS SHOW SHOWERS AND THUNDERSTORMS WEAKENING AS THEY MOVE INTO NORTHWEST MINNESOTA...SO TOOK OUT THE MENTION OF THUNDER AT KINL. LATEST GUIDANCE SHOWS SHOWER AND THUNDERSTORM ACTIVITY DIMINISH IN COVERAGE AS THE NIGHT PROGRESSES DUE TO THE LOSS OF DAYTIME HEATING. HOWEVER THERE STILL COULD BE A COUPLE OF SHOWERS AROUND...SO KEPT VCSH AT KINL...KBRD AND KHIB AS THE FRONT MOVES IN. SUSPECT LITTLE IF ANY PRECIPITATION WILL REACH THE GROUND DUE TO THE VERY DRY AIR IN THE LOWER LEVELS. AS THE FRONT MOVES IN WINDS AT 1.5-2 KFT INCREASE TO 30-35 KTS BETWEEN 06Z-12Z. SO KEPT LLWS AT KDLH AND KHIB...BUT STILL MAY NEED FOR KHYR. SUNDAY AFTERNOON...ADDITIONAL THUNDERSTORM ACTIVITY IS EXPECTED AS THE FRONT MOVES THROUGH. STORMS SHOULD DEVELOP AROUND 18Z...BUT UNCERTAIN ON EXACTLY WHERE THESE STORMS WILL DEVELOP SO KEPT KDLH AT VCTS. PRETTY CONFIDENT THAT KHYR WILL SEE THUNDERSTORMS MOVE THROUGH BETWEEN 20Z-00Z. && .PRELIMINARY POINT TEMPS/POPS... DLH 52 77 44 67 / 30 40 0 0 INL 48 73 38 66 / 20 10 0 0 BRD 54 76 44 70 / 40 30 0 0 HYR 53 77 44 70 / 10 60 20 0 ASX 50 80 44 67 / 10 60 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ UPDATE...DAP SHORT TERM...GSF LONG TERM...LE AVIATION...DAP/WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
735 PM CDT SAT MAY 2 2015 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 324 PM CDT SAT MAY 2 2015 A SFC LOW WAS MOVING INTO NW ONTARIO AT 19Z WITH A TRAILING COLD FRONT SWWD INTO WESTERN ND. A SFC TROF WAS ALSO FOUND IN CENTRAL ND. THUNDERSTORMS WERE FIRING AHEAD OF THIS TROF IN THE VCNTY OF EMBEDDED PIECES OF ENERGY IN FAST ZONAL FLOW ALOFT. AN AREA OF SFC FGEN WAS ALSO CO-LOCATED WITH THE STORMS. EXPECT THIS LINE OF STORMS TO REACH NW MN BY 21Z. THE STORMS WILL CONTINUE TO MOVE EWD AND REACH THE NW CORNER OF KOOCHICHING COUNTY BY 01Z. HOWEVER...IT IS AT THIS POINT IN TIME WHEN THE STORMS BEGIN TO ENCOUNTER DRIER AIR THAT HAS BEEN CAMPED OUT OVER THE FORECAST AREA. LATEST SHORT TERM HIRES MODELS INCLUDING THE HRRR AND RAP SHOW THIS TREND AS WELL. AS THIS INITIAL ROUND OF STORMS DISSOLVES...THE NEXT ROUND WILL BEGIN TO DEVELOP OVER THE WESTERN HALF OF THE AREA AROUND 06Z AS THE SFC FRONT MAKES PROGRESS EWD INTO THE REGION. A LOW LEVEL INVERSION SEEN ON AREA FORECAST SOUNDINGS INDICATE THAT THESE STORMS WILL BE ELEVATED IN NATURE. ON SUNDAY...THE FRONT WILL PROGRESS SLOWLY EWD THROUGH THE DAY. SOME WEAK THUNDERSTORMS WILL BE AROUND IN THE MORNING AS A THERMAL RIDGE AXIS IS OVER THE REGION AND INSTABILITY IS WEAK. BY AFTERNOON...THE FRONT PUSHES INTO NW WI WITH MAX HEATING...STORMS WILL BECOME A BIT MORE VIGOROUS...AND BORDER ON SEVERE. SBCAPE INCREASES TO NEAR 3000 J/KG AND LI/S TO -8C PER FORECAST SOUNDINGS. SHOULD SEE SOME STORMS NEAR SEVERE WITH LARGE HAIL AND BRIEF HEAVY RAIN AS PWATS ARE 1 TO 1.25 INCHES. MODELS COME INTO AGREEMENT WITH THIS SOLUTION AND HAVE ROBUST QPF BY 00Z MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 324 PM CDT SAT MAY 2 2015 SUNDAY EVENING THE COLD FRONT MOVES SOUTHEAST AWAY FROM THE AREA...AND WHILE I HAVE MAINTAINED SOME POPS FOR THE EVENING HOURS...EXPECT THEY WILL ONLY BE ONGOING AT THE VERY BEGINNING OF THE PERIOD AND EXIT QUICKLY DURING THE EVENING. A COOLER AND DRIER AIRMASS MOVES INTO THE AREA AFTER MIDNIGHT AND WILL LINGER THROUGH MONDAY AND MONDAY NIGHT. LOWS SUNDAY NIGHT AND MONDAY NIGHT TO FALL INTO THE MID 30S TO MID 40S FOR MUCH OF THE AREA...WITH HIGHS MONDAY BACK IN THE 60S TO AROUND 70. THE UPPER LEVEL PATTERN IS EXPECTED TO SHIFT TO A LONGWAVE TROUGH OVER THE WEST COAST AND ROCKIES...WITH WEAK RIDGING TO ZONAL FLOW OVER THE EASTERN CONUS. THIS TROUGHINESS TO OUR WEST IS GOING TO SENT A STRONG...SLOW MOVING UPPER LEVEL LOW SHORTWAVE ACROSS THE UPPER MIDWEST TUESDAY THROUGH FRIDAY...WITH SOME FAIRLY HIGH CHANCES FOR PRECIPITATION DURING THE PERIOD. TEMPERATURES WILL ALSO BE ABOVE NORMAL WITH HIGHS IN THE 70S EVEN WITH INCREASED CLOUD COVER AND PRECIPITATION. THIS SYSTEM TO MOVE OFF TO THE NORTHEAST BY SATURDAY...BUT THE UPPER LEVEL PATTERN OF A TROUGH OUT WEST REMAINS WITH WARM AIR STILL BEING FUNNELED IN OUR DIRECTION AND SOME LINGERING PRECIPITATION CHANCES INTO THE WEEKEND. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 735 PM CDT SAT MAY 2 2015 A COLD FRONT HAS TRIGGERED SHOWERS AND THUNDERSTORMS IN EASTERN NORTH DAKOTA AND IN PORTIONS OF FAR NORTHWEST MINNESOTA. THE FRONT WILL CONTINUE MOVING INTO NORTHWEST MINNESOTA TONIGHT. THE LATEST RADAR TRENDS SHOW SHOWERS AND THUNDERSTORMS WEAKENING AS THEY MOVE INTO NORTHWEST MINNESOTA...SO TOOK OUT THE MENTION OF THUNDER AT KINL. LATEST GUIDANCE SHOWS SHOWER AND THUNDERSTORM ACTIVITY DIMINISH IN COVERAGE AS THE NIGHT PROGRESSES DUE TO THE LOSS OF DAYTIME HEATING. HOWEVER THERE STILL COULD BE A COUPLE OF SHOWERS AROUND...SO KEPT VCSH AT KINL...KBRD AND KHIB AS THE FRONT MOVES IN. SUSPECT LITTLE IF ANY PRECIPITATION WILL REACH THE GROUND DUE TO THE VERY DRY AIR IN THE LOWER LEVELS. AS THE FRONT MOVES IN WINDS AT 1.5-2 KFT INCREASE TO 30-35 KTS BETWEEN 06Z-12Z. SO KEPT LLWS AT KDLH AND KHIB...BUT STILL MAY NEED FOR KHYR. SUNDAY AFTERNOON...ADDITIONAL THUNDERSTORM ACTIVITY IS EXPECTED AS THE FRONT MOVES THROUGH. STORMS SHOULD DEVELOP AROUND 18Z...BUT UNCERTAIN ON EXACTLY WHERE THESE STORMS WILL DEVELOP SO KEPT KDLH AT VCTS. PRETTY CONFIDENT THAT KHYR WILL SEE THUNDERSTORMS MOVE THROUGH BETWEEN 20Z-00Z. && .PRELIMINARY POINT TEMPS/POPS... DLH 52 77 44 67 / 10 40 0 0 INL 48 73 38 66 / 10 10 0 0 BRD 54 76 44 70 / 30 30 0 0 HYR 53 77 44 70 / 10 60 20 0 ASX 53 80 44 67 / 10 60 10 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR MNZ010-018-025- 026. WI...NONE. LS...NONE. && $$ SHORT TERM...GSF LONG TERM...LE AVIATION...DAP/WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
331 AM CDT FRI MAY 1 2015 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 331 AM CDT FRI MAY 1 2015 A TROUGH AND SHORTWAVE WERE MOVING INTO WESTERN MINNESOTA THIS MORNING WITH AN AREA OF RAIN OCCURRING AHEAD OF THESE FEATURES. AS OF 0830Z...RAIN STRETCHED FROM NEAR KINL TO KDTL AND SOUTH INTO SOUTHWEST MINNESOTA. THERE WERE ALSO A FEW SHOWERS FURTHER WEST TOWARD KABR. THE MODELS REMAIN IN DECENT AGREEMENT THAT THIS AREA OF RAIN WILL BECOME LESS ORGANIZED AND DIMINISH AS IT MOVES FURTHER EAST INTO DRIER AIR AND AWAY FROM THE BETTER FORCING. OUR POPS REFLECT THIS TREND WITH LIKELY WORDING OVER THE WEST EARLY...AND A SLIGHT CHANCE FAR EAST. ONE CHANGE WE DID MAKE WAS TO ADD A CHANCE FOR SHOWERS TO PORTIONS OF EASTERN MINNESOTA AND NORTHWEST WISCONSIN THIS AFTERNOON INTO THE EVENING. THE LOW LEVEL TROUGH WILL BE A FOCUS AND ACT ON SOME LOW STABILITY AIR WHICH MAY SET OFF A FEW LIGHT SHOWERS. THE MODELS WERE INDICATING THIS CHANCE WITH EARLIER RUNS...AND CONTINUE TO DO SO. SEVERAL OF THE HIGH RESOLUTION MODELS SHOW THIS AS WELL. WE HAVE HIGHS IN THE LOWER SIXTIES TO LOWER SEVENTIES ACROSS THE CWA...WARMEST OVER THE WEST WHERE MORE SUN IS EXPECTED. CLOUDS WILL DIMINISH TONIGHT AND THERE MAY BE SOME PATCHY FOG IN SPOTS INTO EARLY SATURDAY MORNING. SATURDAY WILL BE A WARM DAY FOR MOST AREAS WITH HIGHS FROM THE MID SEVENTIES TO AROUND 80. THERE IS A CONCERN THAT WE MAY BE TOO WARM AROUND LAKE SUPERIOR. THERE MAY BE AN ONSHORE WIND ALONG THE SOUTH SHORE INTO THE TWIN PORTS/TWO HARBORS AREAS THROUGH THE MORNING...BUT MOST OF THE GUIDANCE SUGGESTS WINDS WILL TURN TO SOUTHWEST. IF THIS HAPPENS...IT WILL WARM THE AREAS MENTIONED...BUT KEEP THE NORTH SHORE COOLER THROUGH THE DAY. LOW HUMIDITY AND SOME AFTERNOON SOUTHERLY GUSTS WILL MEAN FIRE WEATHER VALUES WILL APPROACH CRITICAL CONDITIONS...ESPECIALLY FROM THE BRAINERD LAKES REGION NORTH THROUGH INTERNATIONAL FALLS. THE RAIN TODAY WILL DO LITTLE TO MOISTEN FUELS. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 331 AM CDT FRI MAY 1 2015 FORECAST REMAINS WARM AND UNSETTLED INTO NEXT WEEK. A COLD FRONT ASSOCIATED WITH A H85 TROUGH IS FCST TO SWEEP ACROSS NORTH CENTRAL MN SUNDAY MORNING...REACHING THE WESTERN TIP OF LAKE SUPERIOR AND NW WISCONSIN DURING THE AFTERNOON/EARLY EVENING HRS. ATTM...THERE IS SUFFICIENT SHEAR/INSTABILITY AND MOISTURE TO SUPPORT THUNDER AND EVEN A FEW STRONG STORMS WITH THE FRONTAL PASSAGE SUNDAY. LOCATIONS IN NRN WISCONSIN WILL HAVE A THREAT FOR AN ISOLATED SEVERE STORMS WITH LARGE HAIL...AS LATEST NAM BUFR SOUNDINGS SUGGEST PWATS CLIMB IN EXCESS OF AN INCH AND SFC BASED CAPE VALUES ARE IN EXCESS OF 2000 J/KG SUNDAY AFTERNOON. SFC HIGH PRESSURE RETURNS SUNDAY NIGHT/MONDAY AS COLD AIR ALOFT SINKS OVER THE NORTHLAND. MODELS ARE IN GOOD AGREEMENT THAT H85 TEMPERATURES COMMENCE IN THE MID TEENS SUNDAY MORNING...FALLING INTO THE SINGLE DIGITS BY MONDAY MORNING. ALTHOUGH HIGH TEMPS WILL BE COOLER MONDAY...IN THE 50S TO 60S...THE DRY AIR MASS AND STEEP LAPSE RATES WILL PROMOTE DEEP MIXING AND LOW RH VALUES AROUND 20 PERCENT. WINDS WILL GENERALLY BE OUT OF THE NORTHWEST TO NORTH WITH AFTERNOON GUSTS AROUND 15 MPH. FOCUS TURNS TO LONG WAVE TROUGH IN THE WESTERN CONUS THAT EJECTS A SHORT WAVE INTO THE UPPER PLAINS MID-WEEK. THE WAVE WILL BRING GUSTY SOUTHERLY WINDS /EXCEPT EAST NEAR LAKE SUPERIOR/ AND INCREASING MOISTURE TO THE THE REGION. LONG RANGE MODELS SHOW SIGNIFICANT DIFFERENCES IN THE UPPER LEVEL SPLIT FLOW BEYOND WEDNESDAY...WITH A TREND TOWARDS A WET PERIOD THROUGH THE END OF THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1259 AM CDT FRI MAY 1 2015 VFR CONDITIONS EXPECTED AT ALL TERMINALS EXCEPT FOR KBRD BETWEEN 12Z-15Z. MVFR CIGS EXPECTED DURING THIS TIMEFRAME...AS -RA DEVELOPS DUE TO A COLD FRONT PASSING THROUGH. KINL MAY SEE MVFR CIGS FROM TIME TO TIME BETWEEN 10Z AND 15Z...BUT WAS NOT CONFIDENT ENOUGH DUE TO DRIER AIR IN THE LOWER LEVELS. LAST SEVERAL HRRR RUNS SHOW PRECIPITATION DIMINISH IN COVERAGE AS THE FRONT WEAKENS WHILE MOVING THROUGH. AS A RESULT ONLY KEPT VCSH FOR KDLH AND KHIB DUE TO THE DRY AIR AND WEAKENING FRONT. BEHIND THE FRONT CONDITIONS WILL IMPROVE AS HIGH PRESSURE BUILDS IN. && .PRELIMINARY POINT TEMPS/POPS... DLH 67 44 75 49 / 50 20 0 20 INL 70 45 81 49 / 50 10 10 20 BRD 69 48 81 53 / 70 10 0 30 HYR 65 43 80 53 / 20 20 0 10 ASX 69 41 77 51 / 20 20 0 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...MELDE LONG TERM...GRANING AVIATION...GRANING/WL
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1259 AM CDT FRI MAY 1 2015 .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 341 PM CDT THU APR 30 2015 A WEAK COLD FRONT/TROUGH AXIS WILL MOVE THROUGH THE FORECAST AREA TONIGHT AND EARLY FRIDAY...DRAGGING SOME RAIN SHOWERS WITH IT. THE FRONTOGENESIS IS FAIRLY DECENT NOW OVER NORTH DAKOTA WHERE THERE IS A NICE FIELD OF NUMEROUS SHOWERS...BUT WEAKENS TONIGHT AND FRIDAY AS THE FRONT MOVES EAST. TOGETHER WITH THE LARGE AMOUNT OF DRY AIR TO BE OVERCOME AT THE LOW LEVELS...THIS IS GOING TO LIMIT OUR PRECIPITATION AMOUNTS. THE WESTERN CWA HAS THE BEST POTENTIAL FOR GETTING FROM ONE TO TWO TENTHS OF AN INCH...BUT SOME LOCATIONS FARTHER EAST MAY ONLY GET A TRACE. TEMPERATURES TOMORROW WILL BE LIMITED BY THE CLOUD COVER AND PRECIPITATION...BUT WITH THE STRONG WARM AIR ADVECTION GOING ON WE SHOULD STILL GET BACK INTO THE MID 60S TO NEAR 70. LOWS TONIGHT WILL BE BACK IN THE MID 30S TO MID 40S MOST LOCATIONS...THOUGH SOME PLACES ALONG THE NORTH SHORE MAY DIP TO AROUND FREEZING. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 341 PM CDT THU APR 30 2015 A MILD AND ACTIVE WEATHER PATTERN THROUGH THE WEEKEND AND THROUGH MUCH OF NEXT WEEK. ON THE SYNOPTIC SCALE MID/UPPER LEVEL FLOW WILL BE GENERALLY WEST-SOUTHWEST THROUGH THE WEEKEND WITH SOUTHWESTERLY FLOW AT LOW LEVELS BRINGING IN MUCH WARMER AIR...ALLOWING HIGHS TO REACH THE MID TO UPPER 70S ON SATURDAY AND SUNDAY. A COLD FRONT WILL MOVE THROUGH ON SATURDAY NIGHT INTO SUNDAY WHICH WILL BRING CLOUDS AND A CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS. MOST OF THE RAIN WILL FALL SUNDAY AFTERNOON INTO THE EVENING ACROSS NORTHWEST WISCONSIN...WITH THE POTENTIAL FOR UP TO A HALF INCH OR MORE IN SOME LOCATIONS FROM THE SAINT CROIX RIVER VALLEY EAST TO SOUTHERN PORTIONS OF THE CHEQUAMEGON NATIONAL FOREST. HIGH PRESSURE MOVES IN BEHIND THE COLD FRONT WITH 850MB TEMPS PLUNGING FROM 12-14C SATURDAY AFTERNOON TO 3-5C BY MONDAY MORNING...THOUGH WITH CLEARING SKIES AS HIGH PRESSURE MOVES IN AND DEEP MIXING TAKING PLACE EXPECT HIGHS IN THE 60S MONDAY AND APPROACHING 70 ON TUESDAY. IT WILL ALSO BE DRY WITH MINIMUM AFTERNOON RELATIVE HUMIDITY VALUES IN THE 25 TO 35 PERCENT RANGE...WITH LIGHT AND VARIABLE WINDS AS HIGH PRESSURE MOVES ACROSS THE UPPER GREAT LAKES. AN UPPER LEVEL LOW WILL MOVE ACROSS THE FOUR CORNERS REGION ON TUESDAY AND BE EJECTED NORTH/NORTHEAST INTO THE PLAINS AND UPPER MIDWEST LATE WEDNESDAY INTO THURSDAY...WITH A STREAM OF MOIST GULF AIR AHEAD OF IT RAISING PWAT VALUES TO WELL ABOVE NORMAL. THERE IS THE POTENTIAL FOR MODERATE TO HEAVY RAINFALL WITH THIS PATTERN THROUGH THE LATTER PORTION OF THE WORK WEEK. TEMPERATURES WILL GENERALLY BE SEASONABLE TO ABOVE NORMAL...WITH HIGHS IN THE 60S TO NEAR 70 ON WEDNESDAY AND THURSDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1259 AM CDT FRI MAY 1 2015 VFR CONDITIONS EXPECTED AT ALL TERMINALS EXCEPT FOR KBRD BETWEEN 12Z-15Z. MVFR CIGS EXPECTED DURING THIS TIMEFRAME...AS -RA DEVELOPS DUE TO A COLD FRONT PASSING THROUGH. KINL MAY SEE MVFR CIGS FROM TIME TO TIME BETWEEN 10Z AND 15Z...BUT WAS NOT CONFIDENT ENOUGH DUE TO DRIER AIR IN THE LOWER LEVELS. LAST SEVERAL HRRR RUNS SHOW PRECIPITATION DIMINISH IN COVERAGE AS THE FRONT WEAKENS WHILE MOVING THROUGH. AS A RESULT ONLY KEPT VCSH FOR KDLH AND KHIB DUE TO THE DRY AIR AND WEAKENING FRONT. BEHIND THE FRONT CONDITIONS WILL IMPROVE AS HIGH PRESSURE BUILDS IN. && .PRELIMINARY POINT TEMPS/POPS... DLH 45 73 50 72 / 0 0 20 50 INL 40 78 49 70 / 0 10 20 20 BRD 45 78 54 74 / 0 0 30 50 HYR 44 76 53 77 / 10 0 10 40 ASX 42 75 51 76 / 10 0 10 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...LE LONG TERM...LE AVIATION...GRANING/WL
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1244 PM CDT Fri May 1 2015 .UPDATE: Issued at 1152 AM CDT Fri May 1 2015 Based on cloud trends from this morning`s satellite imagery, afternoon update will increase the clouds a bit faster over our far NW counties. Otherwise, forecast is looking good and generally remains unchanged. Truett && .SHORT TERM: (Through Late This Afternoon) Issued at 322 AM CDT Fri May 1 2015 Dry and tranquil weather is expected today as weak height rises commence aloft with the departure of the mid Atlantic upper low/trof and eastward shift in the upper ridge currently centered in the southern Rockies. The surface high centered in northern IL will only meander southeast. This will translate to a nice day with light winds, lots of morning sun, and some thin high clouds in the afternoon. Temperatures will be seasonable and forecast highs are a blend of the warmer MAV MOS and RAP 2m temps. Glass .LONG TERM: (Tonight through Thursday) Issued at 322 AM CDT Fri May 1 2015 The tail end of a weak short wave passing to the north will bring an increase in cloudiness overnight. The persistent and ever so slowly retreating low level anticyclone will limit low level moisture transport/return to the Plains into Iowa. That said the increase in mid level moisture and warm advection may be sufficient for spotty showers across parts of northeast MO. While southerly flow and WAA becomes better established Saturday and Saturday night in the wake of the slow retreating anticyclone, trajectories are poor for low level moisture return. Once again the main impetus for pops will be mid level moisture, WAA, glancing influence from passing disturbances, and some marginal elevated instability leading to slight chance pops across parts of northeast MO and west central IL. The ridge aloft builds east into the OH Valley on Sunday and the threat of precipitation takes a decided northward shift to the vicinity of a cold front moving through the northern Plains and upper MS Valley. The threat of showers and thunderstorms will progressively increase late Sunday night into Monday night as the cold front approaches Sunday night and then becomes quasi-stationary across northern MO and west central IL Monday into Monday night. By this time the low level moisture and hence instability is much improved owing to persistent s-sw lower trop flow and presence of steep mid level lapse rates. This front then moves back north by midweek leading to a diminished precipitation threat, which increases again late week with the development of southwest flow aloft and accompanying disturbances and continued low level moisture transport. Temperatures will be above average beginning this weekend and continuing all of next week. Glass && .AVIATION: (For the 18z TAFs through 18z Saturday Afternoon) Issued at 1242 PM CDT Fri May 1 2015 Several weak shortwaves will pass over the region during the next 24 hours. However, low level moisture will be non-existent thanks to surface ridge maintaining its firm grip over the mid- Mississippi Valley, so impacts of the shortwave energy will be limited to occasional bands of mid level cloudiness (with bases aoa 8kft). Any threat of rain will remain very low. Surface winds will also remain quite light. Specifics for KSTL: VFR conditions will continue into the start of the weekend, with the clear skies of this afternoon giving way to a bit of mid level cloudiness (bases aoa 8kft) tonight and into Saturday. Winds will remain quite light...generally aob 6 kts...into Saturday morning. Truett && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1154 AM CDT Fri May 1 2015 .UPDATE: Issued at 1152 AM CDT Fri May 1 2015 Based on cloud trends from this morning`s satellite imagery, afternoon update will increase the clouds a bit faster over our far NW counties. Otherwise, forecast is looking good and generally remains unchanged. Truett && .SHORT TERM: (Through Late This Afternoon) Issued at 322 AM CDT Fri May 1 2015 Dry and tranquil weather is expected today as weak height rises commence aloft with the departure of the mid Atlantic upper low/trof and eastward shift in the upper ridge currently centered in the southern Rockies. The surface high centered in northern IL will only meander southeast. This will translate to a nice day with light winds, lots of morning sun, and some thin high clouds in the afternoon. Temperatures will be seasonable and forecast highs are a blend of the warmer MAV MOS and RAP 2m temps. Glass .LONG TERM: (Tonight through Thursday) Issued at 322 AM CDT Fri May 1 2015 The tail end of a weak short wave passing to the north will bring an increase in cloudiness overnight. The persistent and ever so slowly retreating low level anticyclone will limit low level moisture transport/return to the Plains into Iowa. That said the increase in mid level moisture and warm advection may be sufficient for spotty showers across parts of northeast MO. While southerly flow and WAA becomes better established Saturday and Saturday night in the wake of the slow retreating anticyclone, trajectories are poor for low level moisture return. Once again the main impetus for pops will be mid level moisture, WAA, glancing influence from passing disturbances, and some marginal elevated instability leading to slight chance pops across parts of northeast MO and west central IL. The ridge aloft builds east into the OH Valley on Sunday and the threat of precipitation takes a decided northward shift to the vicinity of a cold front moving through the northern Plains and upper MS Valley. The threat of showers and thunderstorms will progressively increase late Sunday night into Monday night as the cold front approaches Sunday night and then becomes quasi-stationary across northern MO and west central IL Monday into Monday night. By this time the low level moisture and hence instability is much improved owing to persistent s-sw lower trop flow and presence of steep mid level lapse rates. This front then moves back north by midweek leading to a diminished precipitation threat, which increases again late week with the development of southwest flow aloft and accompanying disturbances and continued low level moisture transport. Temperatures will be above average beginning this weekend and continuing all of next week. Glass && .AVIATION: (For the 12z TAFs through 12z Saturday Morning) Issued at 550 AM CDT Fri May 1 2015 VFR conditions with light and vrb winds anticipated thru the period. RA can not be ruled out at UIN late tonight. Otherwise, no precip anticipated at terminals. && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
551 AM CDT Fri May 1 2015 .SHORT TERM: (Through Late This Afternoon) Issued at 322 AM CDT Fri May 1 2015 Dry and tranquil weather is expected today as weak height rises commence aloft with the departure of the mid Atlantic upper low/trof and eastward shift in the upper ridge currently centered in the southern Rockies. The surface high centered in northern IL will only meander southeast. This will translate to a nice day with light winds, lots of morning sun, and some thin high clouds in the afternoon. Temperatures will be seasonable and forecast highs are a blend of the warmer MAV MOS and RAP 2m temps. Glass .LONG TERM: (Tonight through Thursday) Issued at 322 AM CDT Fri May 1 2015 The tail end of a weak short wave passing to the north will bring an increase in cloudiness overnight. The persistent and ever so slowly retreating low level anticyclone will limit low level moisture transport/return to the Plains into Iowa. That said the increase in mid level moisture and warm advection may be sufficient for spotty showers across parts of northeast MO. While southerly flow and WAA becomes better established Saturday and Saturday night in the wake of the slow retreating anticyclone, trajectories are poor for low level moisture return. Once again the main impetus for pops will be mid level moisture, WAA, glancing influence from passing disturbances, and some marginal elevated instability leading to slight chance pops across parts of northeast MO and west central IL. The ridge aloft builds east into the OH Valley on Sunday and the threat of precipitation takes a decided northward shift to the vicinity of a cold front moving through the northern Plains and upper MS Valley. The threat of showers and thunderstorms will progressively increase late Sunday night into Monday night as the cold front approaches Sunday night and then becomes quasi-stationary across northern MO and west central IL Monday into Monday night. By this time the low level moisture and hence instability is much improved owing to persistent s-sw lower trop flow and presence of steep mid level lapse rates. This front then moves back north by midweek leading to a diminished precipitation threat, which increases again late week with the development of southwest flow aloft and accompanying disturbances and continued low level moisture transport. Temperatures will be above average beginning this weekend and continuing all of next week. Glass && .AVIATION: (For the 12z TAFs through 12z Saturday Morning) Issued at 550 AM CDT Fri May 1 2015 VFR conditions with light and vrb winds anticipated thru the period. RA can not be ruled out at UIN late tonight. Otherwise, no precip anticipated at terminals. && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
343 AM CDT Fri May 1 2015 .SHORT TERM: (Through Late This Afternoon) Issued at 322 AM CDT Fri May 1 2015 Dry and tranquil weather is expected today as weak height rises commence aloft with the departure of the mid Atlantic upper low/trof and eastward shift in the upper ridge currently centered in the southern Rockies. The surface high centered in northern IL will only meander southeast. This will translate to a nice day with light winds, lots of morning sun, and some thin high clouds in the afternoon. Temperatures will be seasonable and forecast highs are a blend of the warmer MAV MOS and RAP 2m temps. Glass .LONG TERM: (Tonight through Thursday) Issued at 322 AM CDT Fri May 1 2015 The tail end of a weak short wave passing to the north will bring an increase in cloudiness overnight. The persistent and ever so slowly retreating low level anticyclone will limit low level moisture transport/return to the Plains into Iowa. That said the increase in mid level moisture and warm advection may be sufficient for spotty showers across parts of northeast MO. While southerly flow and WAA becomes better established Saturday and Saturday night in the wake of the slow retreating anticyclone, trajectories are poor for low level moisture return. Once again the main impetus for pops will be mid level moisture, WAA, glancing influence from passing disturbances, and some marginal elevated instability leading to slight chance pops across parts of northeast MO and west central IL. The ridge aloft builds east into the OH Valley on Sunday and the threat of precipitation takes a decided northward shift to the vicinity of a cold front moving through the northern Plains and upper MS Valley. The threat of showers and thunderstorms will progressively increase late Sunday night into Monday night as the cold front approaches Sunday night and then becomes quasi-stationary across northern MO and west central IL Monday into Monday night. By this time the low level moisture and hence instability is much improved owing to persistent s-sw lower trop flow and presence of steep mid level lapse rates. This front then moves back north by midweek leading to a diminished precipitation threat, which increases again late week with the development of southwest flow aloft and accompanying disturbances and continued low level moisture transport. Temperatures will be above average beginning this weekend and continuing all of next week. Glass && .AVIATION: (For the 06z TAFs through 06z Friday Night) Issued at 1143 PM CDT Thu Apr 30 2015 Large dome of high pressure over the upper Great Lakes and upper Mississippi Valley will be building south, maintaining a firm control over the region`s weather heading into the start of the weekend. VFR conditions will continue at all TAF locations, with little in the way of cloudiness and light winds. Specifics for KSTL: VFR conditions are forecast through Friday, with only a bit of cirrus from time to time along with light surface winds. Truett && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
908 AM MDT FRI MAY 1 2015 .SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SUNDAY... CHINOOK ARCH HAS INTRODUCED A BOUNTIFUL AMOUNT OF HIGH CLOUDINESS ACROSS THE CWA THIS MORNING. WITH WATER VAPOR SHOWING ADDITIONAL MOISTURE UPSTREAM...THINK RUC HAS A GOOD HANDLE ON SKY AND THUS HAVE INCREASED CLOUDS INTO TONIGHT. ALSO RAISED RH A BIT. REST OF FORECAST LOOKED GOOD. TFJ PREVIOUS DISCUSSION... ZONAL FLOW OVER THE PACIFIC NORTHWEST AND NORTHERN ROCKIES OVER THE NEXT FEW DAYS WILL PRODUCE DRY AND WARM CONDITIONS FOR NORTHEAST MONTANA. A SHORTWAVE DIPPING THROUGH WESTERN CANADA OVER THE WEEKEND WILL INTRODUCE SOME SLIGHT CYCLONIC CURVATURE TO THE UPPER FLOW AND PUSH A COLD FRONT INTO NORTHERN MONTANA. MOST OF THE MOISTURE AND ENERGY WITH THIS SYSTEM REMAINS WELL NORTH...SO MAINLY EXPECT A WIND SHIFT FROM SOUTHWEST TO NORTHWEST EARLY ON SATURDAY AND TEMPERATURES COOLING SLIGHTLY FROM TODAY INTO SUNDAY. EBERT .LONG TERM...SUNDAY NIGHT THROUGH FRIDAY... THE EXTENDED FORECAST PERIOD BEGINS SUNDAY NIGHT WITH GENERALLY ZONAL FLOW ALOFT OVER NORTHEAST MONTANA. OFF TO THE WEST THERE WILL BE SHALLOW...MEDIUM-WAVE RIDGE BEGINNING TO WORK ITS WAY EAST. THE WAVE NEVER GAINS MUCH STRENGTH AS IT PASSES OVER THE LOCAL REGION LATE MONDAY. BUT GREAT BASIN WARMTH DOES PUSH NORTH INTO MONTANA TO MAINTAIN SLIGHTLY ABOVE NORMAL TEMPERATURES. BOTH GFS AND THE EC DEVELOP A CLOSED UPPER LOW OFF THE NORTHWEST COAST MONDAY NIGHT. THIS LOW BEGINS TO PUSH THROUGH THE INTER- MOUNTAIN WEST. MORE WARM AIR IS THUS NUDGED NORTH INTO OUR AREA FOR A WARMER TUESDAY. TUESDAY NIGHT AND WEDNESDAY BEGINS A WET PROGRESSIVE PATTERN...A SURFACE TROUGH IN THE LEE OF THE NORTHERN ROCKIES MOVES OVER THE LOCAL REGION CREATING INSTABILITY. FLOW ALOFT TURNS SOUTHWEST SENDING MOISTURE FROM THE WESTERN TROUGH INTO THE LOCAL AREA. TIMING IS NOT CERTAIN YET BUT BOTH GFS AND EC SUGGEST MODERATE CAPE AND NEGATIVE LIFTED INDEX VALUES. THE SET-UP APPEARS GOODS FOR AT LEAST GENERAL THUNDERSTORM DEVELOP LATE TUESDAY AND WEDNESDAY. INTO THURSDAY THE MODELS SPLIT THE TROUGH INTO A SOUTHWESTERN WAVE AND A NORTHEASTERN WAVE...WITH THE NORTHERN PORTION AFFECTING THE AREA WITH CONTINUED CONVECTION AND SHOWERS. SCT && .AVIATION... SOME HIGH CLOUDS AROUND FL240 DUE TO CHINOOK ARCHING FROM WESTERLY FLOW ALOFT OVER THE NORTHERN ROCKIES. FLOW PATTERN ALOFT IS FAIRLY STABLE FOR THE NEXT 24 HOURS. AT THE SURFACE...A TROUGH OF LOW PRESSURE WILL PASS THROUGH THE AREA FRIDAY EVENING AND VEER THE WINDS AROUND FROM 5 TO 15KTS SOUTHWESTERLY TO 5 TO 15 KTS NORTHWESTERLY. NO PRECIPITATION IS EXPECTED WITH THE FRONTAL PASSAGE AND CONDITIONS WILL REMAIN WELL WITHIN VFR LIMITS. MARTIN && .CLIMATE... APRIL CAME UP A BIT WET FOR THE WESTERN ZONES AND NEAR NORMAL TO THE EAST. A GRAPHIC EXPLAINING THIS A BIT WAS POSTED ON OUR FACEBOOK PAGE THIS MORNING. TFJ && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
857 AM MDT FRI MAY 1 2015 .UPDATE... MADE JUST A FEW ADJUSTMENTS TO THE GOING FORECAST. A DRY ZONAL FLOW WITH A JET TO THE N WAS OVER THE FORECAST AREA THIS MORNING. JET WAS BRINGING SOME CLOUDINESS TO FAR NORTHERN SECTIONS PER SATELLITE IMAGERY...SO ADJUSTED SKY COVER TO MATCH UP WITH SATELLITE TRENDS. SOME CLOUDS WILL MOVE IN THIS AFTERNOON AS WELL...AS A WEAK SHORTWAVE MOVES INTO THE AREA. FORECAST HAS THIS COVERED WELL. THE RAP SOUNDINGS SHOWED A VERY DRY AIRMASS THROUGH JUST ABOUT THE ENTIRE COLUMN THROUGH THIS AFTERNOON WHICH WILL ALLOW FOR GOOD MIXING. LOWERED DEWPOINTS A FEW DEGREES AND INCREASED WIND SPEEDS A BIT. SOME AFTERNOON GUSTS ABOVE 20 MPH ARE POSSIBLE. TEMPERATURES WERE IN GOOD SHAPE BASED ON THE EXPECTED MIXING. A COLD FRONT WILL MOVE S THROUGH THE AREA ON SAT AND GENERATE ISOLATED MOUNTAIN SHOWERS WITH POSSIBLE THUNDERSTORMS. ARTHUR && .SHORT TERM...VALID FOR TDY AND SAT... QUIET WEATHER PATTERN FOR THE MOST PART CAN BE EXPECTED FOR THE NEXT COUPLE OF DAYS ACROSS OUR FORECAST AREA. A FAST ZONAL FLOW ALOFT WILL MOVE ACROSS OUR AREA TODAY AND THROUGH MOST OF SATURDAY BEFORE THE FLOW BECOMES A BIT NORTHWEST BY LATE SATURDAY. SKIES WILL BE MOSTLY SUNNY TODAY WITH ABOVE NORMAL TEMPERATURES AS READINGS WILL WARM INTO THE MIDDLE TO UPPER 70S FOR MOST LOCATIONS. A COLD FRONT DROPS SOUTH ACROSS THE AREA SATURDAY AFTERNOON BRINGING A WIND SHIFT TO THE NORTHWEST THEN NORTHEAST BY SATURDAY NIGHT. MODELS DON`T SHOW MUCH IN THE WAY OF MOISTURE ASSOCIATED WITH THE FRONT BUT WE CAN`T RULE OUT AN ISOLATED SHOWER. TEMPERATURES AGAIN WILL BE QUITE WARM WITH READINGS IN THE MIDDLE TO UPPER 70S AND POSSIBLY AN 80 DEGREE READING FOR SOME AREAS SATURDAY AFTERNOON. HOOLEY .LONG TERM...VALID FOR SUN...MON...TUE...WED...THU... THE DISPARITY BETWEEN THE MODEL SOLUTIONS FOR THE LOW MIDWEEK NEXT WEEK CONTINUES...IF NOT HAS WIDENED A LITTLE. THE GFS CONTINUES TO TRACK THE LOW SOUTH OVER NEVADA AND ARIZONA...THE ECMWF TRACKS THE LOW ACROSS SOUTHERN CANADA. THE 12Z RUN OF THE EC HAD BETTER AGREEMENT WITH THE GFS SOLUTIONS...BUT WITH THE 00Z RUN HAS SINCE BACKED OFF THE PREVIOUS TRACK. GIVEN THAT NONE OF THE SOLUTIONS ARE STABLE ENOUGH TO LEAN ONE WAY OR THE OTHER...HAVE NOT MADE ANY MAJOR CHANGES TO THE FORECAST. PRETTY MUCH KEPT POPS IN THE 30 TO 40 PERCENT RANGE. ONE THING THAT DOES LOOK LIKELY IS A GENERAL COOLING TREND DURING THE SECOND HALF OF THE WEEK. THE QUESTION OF HOW MUCH REMAINS UNCERTAIN. KEPT TEMPERATURES MAINLY IN THE LOWER 60S..MAYBE TRENDING A DEGREE OR TWO COOLER. FOR THE FIRST HALF OF THE WEEK...THE AREA WILL REMAIN IN FAST WESTERLY FLOW. SEVERAL WEAK WAVES WILL QUICKLY MOVE ACROSS THE AREA. THIS WILL KEEP CHANCES FOR RAIN. THE BEST CHANCES WILL BE IN THE HIGHER TERRAIN...BUT SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE OUT ONTO THE PLAINS. REIMER && .AVIATION... VFR CONDITIONS WILL PREVAIL AT ALL TERMINALS TODAY. WIND GUSTS MAY APPROACH 20 MPH NEAR KLVM AND KBIL BY THIS AFTERNOON...BUT SHOULD DWINDLE BY THE EVENING HOURS. SINGER && .PRELIMINARY POINT TEMP/POPS... TDY SAT SUN MON TUE WED THU ------------------------------------------------------- BIL 078 048/078 045/066 043/070 045/076 047/067 042/060 0/U 00/B 22/T 32/T 22/T 23/W 33/W LVM 075 039/075 036/068 037/071 040/075 040/065 037/059 0/U 02/T 13/T 32/T 23/T 33/W 33/W HDN 082 043/083 041/069 042/071 043/077 045/070 041/061 0/U 00/B 21/B 32/T 22/T 23/W 33/W MLS 077 048/079 044/066 042/067 045/074 047/068 042/063 0/U 00/B 21/B 32/T 12/T 23/W 33/W 4BQ 078 043/081 043/068 043/065 045/071 047/067 041/062 0/U 00/U 11/B 33/T 22/T 33/W 33/W BHK 078 044/078 041/064 039/061 041/069 045/065 040/061 0/U 00/B 21/B 33/T 11/N 23/W 33/W SHR 075 039/077 040/066 039/067 041/070 040/064 040/057 0/U 00/U 12/T 33/T 23/T 33/W 33/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
243 PM CDT FRI MAY 1 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 242 PM CDT FRI MAY 1 2015 WEAK HIGH PRESSURE OVERHEAD WILL PIVOT MOISTURE NORTHWARD THIS EVENING. THE RAP AND HRRR SUGGEST WEAKLY ORGANIZED DISCRETE SHOWER AND THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON AND THIS EVENING. OTHER THAN GUSTY OUTFLOW WINDS...NO SIGNIFICANT WEATHER IS EXPECTED AND NO STORMS SHOULD REACH SEVERE LIMITS. A WARM FRONT WILL LIFT NORTH AS THE HIGH MOVES EAST LATER THIS EVENING. DEW POINTS SHOULD INCREASE TO AROUND 50F BY MID SATURDAY MORNING. THE NAM CONTINUES TO ADVERTISE A FAIRLY ROBUST DRYLINE SURGE SATURDAY AFTN FOCUSED ALONG HIGHWAY 20 WEST OF VALENTINE. DESTABILIZATION IS POSSIBLE ACROSS PINE RIDGE AND THE WRN SANDHILLS SOUTH THROUGH IMPERIAL AROUND 21Z. THE NAM DID SHOW ABOUT 20 TO 30 J/KG OF INHIBITION SO POPS ARE ISOLATED. MLCAPE NEAR 1500 J/KG AND BULK SHEAR TO 450 MB OF 30 TO 35 KT COULD SUPPORT AN ISOLATED STRONG OR SEVERE STORM DURING THE PEAK HEATING PERIOD. THE BULK RICHARDSON NUMBER IS CLOSE TO 50 AT THIS TIME AND SHEAR PROFILES LOOK SMOOTHLY CURVED. LOWS TONIGHT FALL TO THE UPPER 40S TO AROUND 50. HIGHS SATURDAY RISE INTO THE LOW TO MID 80S WITH MIXING HEIGHTS NEAR 700 MB. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 242 PM CDT FRI MAY 1 2015 A TRAJECTORY FROM THE PACIFIC SOUTHWEST CONTINUES SATURDAY NIGHT WHILE A TRAJECTORY FROM THE TEXAS GULF COAST CROSSES CENTRAL AND EASTERN NEBRASKA. THE PACIFIC MOISTURE WILL THUS BE IN PLACE WHEN A SURFACE FRONT COMES THROUGH SUNDAY MORNING. THE TIMING OF THE FRONT IS NOT REAL FAVORABLE FOR THUNDERSTORMS. HOWEVER...THE LIFT SHOULD BE SUFFICIENT TO TRIGGER ISOLATED CONVECTION BY SUNDAY EVENING WITH IT CONTINUING SUNDAY NIGHT AND MONDAY IN CENTRAL AND SOUTHWEST NEBRASKA. WITH THE FRONT BECOMING STATIONARY ACROSS CENTRAL KANSAS...SOME UPGLIDE WILL CONTINUE INTO MONDAY AFTERNOON AND EVENING. THIS CAN BE SEEN WITH THE PRESSURE LEVELS AND MOISTURE TRANSPORT VECTORS OVER CENTRAL...SOUTH CENTRAL AND SOUTHWEST NEBRASKA ON THE 300K AND 305K SURFACES. THE INSTABILITY...AT ABOUT 0C FOR THE 800MB BASED LIFTED INDEX...IS EXPECTED TO BE MARGINAL. AS A RESULT...ONLY A FEW EMBEDDED THUNDERSTORMS ARE EXPECTED IN AN AREA OF GENERAL RAIN OR SHOWERS. WITH PRECIPITABLE WATER EXCEEDING 0.7 INCH...SIGNIFICANT PRECIPITATION TOTALS CAN BE EXPECTED ALONG A BROKEN BOW-NORTH PLATTE-IMPERIAL LINE AND SOUTH WITH AMOUNTS DROPPING OFF SHARPLY NORTH OF THAT LINE. AS THE ACTIVE UPPER PATTERN CONTINUES...ANOTHER NEGATIVELY TILTED TROUGH PIVOTS ACROSS THE NORTHERN PLAINS. AHEAD OF THE SYSTEM...A GOOD MOISTURE TRAJECTORY CONTINUES TUESDAY NIGHT AND WEDNESDAY FROM THE TEXAS GULF COAST INTO NEBRASKA AND THE DAKOTAS. AS THE CYCLONE MAKES ITS WAY NORTHWARD...WARM ADVECTION ALOFT WILL CONTINUE BRINGING WIDESPREAD RAINFALL TO WESTERN NEBRASKA. BY EARLY THURSDAY...THE DRY INTRUSION OVERTAKES THE CYCLONE AND BRINGS AN END TO THE PRECIPITATION IN CENTRAL AND WESTERN NEBRASKA. THERE IS SIGNIFICANT DISAGREEMENT BETWEEN THE 00Z ECMWF AND THE 12Z GFS40 WITH THIS SYSTEM...SO CONFIDENCE IS NOT HIGH IN THE SOLUTIONS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1224 PM CDT FRI MAY 1 2015 VFR IS EXPECTED ALONG AND NORTH OF HIGHWAY 2 THIS AFTN THROUGH SATURDAY MORNING. SOUTH OF THIS AREA ISOLATED WEAKLY ORGANIZED SHOWER AND THUNDERSTORM COVERAGE IS EXPECTED FROM 21Z THIS AFTERNOON THROUGH 08Z TONIGHT. VFR IS EXPECTED ALL AREAS THEREAFTER. STORM DEVELOPMENT IS EXPECTED ALONG THE LARAMIE AND COLORADO RANGES 18Z-21Z WITH ACTIVITY MOVING EAST INTO THE FORECAST AREA THIS EVENING. OTHER ISOLATED ACTIVITY COULD DEVELOP ALONG AND SOUTH OF INTERSTATE 80 THIS AFTERNOON 21Z-00Z. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CDC LONG TERM...SPRINGER AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
110 PM CDT FRI MAY 1 2015 .SHORT TERM...(TODAY) ISSUED AT 341 AM CDT FRI MAY 1 2015 PCPN CHANCES/PCPN COVERAGE AND TEMPERATURES WILL PROVIDE THE MAIN FORECAST CHALLENGES FOR THE TODAY PERIOD. REGIONAL RADAR LOOP EARLY THIS MORNING SHOWED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS OCCURRING IN ASSOCIATION WITH A WEAK COLD FRONT MOVING EASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS. THIS FRONT SHOULD STALL OUT AND THEN WASH OUT THIS EVENING. LATEST SHORT RANGE HIGH RESOLUTION MODELS ARE IN DECENT AGREEMENT SHOWING SOME SCATTERED AND MAINLY LIGHT PCPN MOVING ACROSS THE FORECAST AREA THIS MORNING. 06Z RAP SEEMED TO HAVE A FAIRLY GOOD HANDLE ON THE PATTERN. LOOK FOR HIGHS MOSTLY IN THE LOWER AND MID 70S BUT A FEW LOCATIONS IN WEST CENTRAL IOWA MAY ONLY REACH NEAR 70. MILLER SHORT TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 341 AM CDT FRI MAY 1 2015 FOCUS FOR POSSIBLE PCPN SHIFTS TO THE SRN CWA TONIGHT AND SATURDAY MORNING WHERE 310K UPGLIDE AND LOW COND PRES DEF WILL BE MOST PREVALENT. NEXT ROUND OF PCPN ASSOCIATED WITH A COLD FRONT DROPPING THRU THE DAKOTAS/UPPER MID WEST SATURDAY NIGHT THE INTO THE CWA ON SUNDAY. MODELS HOLD OFF DEVELOPMENT UNTIL AFTN WHEN ENVIRONMENT BECOMES ADEQUATELY UNSTABLE...THEN INCREASES IN AREAL COVERAGE AND INTENSITY SUNDAY NIGHT IN RESPONSE TO STRENGTHENING BNDRY LYR MOISTURE CONVERGENCE. WITH RELATIVELY HIGH CONCENTRATION OF ENVIRONMENTAL MOISTURE AND PERSISTENT FORCING...CONDITIONS WILL BE FAVORABLE FOR SOME LOCATIONS TO SEE RAINFALL AMOUNTS OF HALF AND INCH OR SO. DEE .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 341 AM CDT FRI MAY 1 2015 SFC BNDRY AT THIS POINT PROGGED TO BECOME NEARLY STATIONARY MONDAY MORNING THRU TUESDAY MORNING. PERSISTENT INFLUX OF GULF MOISTURE COUPLED WITH MOIST BNDRY LYR CONVERGENCE/INSTABILITY AXIS SITUATED OVER THE CWA WOULD SUGGEST CONDITIONS WILL AGAIN BE FAVORABLE FOR SIGNIFICANT RAINFALL ACCUMULATIONS. TUESDAY AFTN THRU THURSDAY NIGHT PCPN ACCUMULATIONS BEING DRIVEN BY EXTENDED PERIOD OF 305K UPGLIDE/PRESIDENT LLVL MOISTURE ADVECTION. OTHERWISE...METEOGRAMS STILL SHOWING MODERATE COOL NEXT WEEK IN LIGHT OF SFC BNDRY MOVING IN. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 107 PM CDT FRI MAY 1 2015 MAINLY VFR CONDITIONS ARE FORECAST THROUGH SATURDAY MORNING. SCATTERED SHOWERS MAY AFFECT ALL TAF SITES THROUGH THE AFTERNOON...BUT STILL EXPECT VFR CIGS/VSBYS IN ALL BUT THE HEAVIEST SHOWERS. THERE SHOULD BE PERIOD OF DRY WEATHER DURING THE EVENING...WITH MORE SHOWERS MOVING TOWARD KLNK AND KOMA AFTER 06Z. AGAIN MAINLY VFR CIGS/VSBYS ARE FORECAST WITH THIS ACTIVITY. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER/DEE LONG TERM...DEE AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
620 AM CDT FRI MAY 1 2015 .SHORT TERM...(TODAY) ISSUED AT 341 AM CDT FRI MAY 1 2015 PCPN CHANCES/PCPN COVERAGE AND TEMPERATURES WILL PROVIDE THE MAIN FORECAST CHALLENGES FOR THE TODAY PERIOD. REGIONAL RADAR LOOP EARLY THIS MORNING SHOWED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS OCCURRING IN ASSOCIATION WITH A WEAK COLD FRONT MOVING EASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS. THIS FRONT SHOULD STALL OUT AND THEN WASH OUT THIS EVENING. LATEST SHORT RANGE HIGH RESOLUTION MODELS ARE IN DECENT AGREEMENT SHOWING SOME SCATTERED AND MAINLY LIGHT PCPN MOVING ACROSS THE FORECAST AREA THIS MORNING. 06Z RAP SEEMED TO HAVE A FAIRLY GOOD HANDLE ON THE PATTERN. LOOK FOR HIGHS MOSTLY IN THE LOWER AND MID 70S BUT A FEW LOCATIONS IN WEST CENTRAL IOWA MAY ONLY REACH NEAR 70. MILLER SHORT TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 341 AM CDT FRI MAY 1 2015 FOCUS FOR POSSIBLE PCPN SHIFTS TO THE SRN CWA TONIGHT AND SATURDAY MORNING WHERE 310K UPGLIDE AND LOW COND PRES DEF WILL BE MOST PREVALENT. NEXT ROUND OF PCPN ASSOCIATED WITH A COLD FRONT DROPPING THRU THE DAKOTAS/UPPER MID WEST SATURDAY NIGHT THE INTO THE CWA ON SUNDAY. MODELS HOLD OFF DEVELOPMENT UNTIL AFTN WHEN ENVIRONMENT BECOMES ADEQUATELY UNSTABLE...THEN INCREASES IN AREAL COVERAGE AND INTENSITY SUNDAY NIGHT IN RESPONSE TO STRENGTHENING BNDRY LYR MOISTURE CONVERGENCE. WITH RELATIVELY HIGH CONCENTRATION OF ENVIRONMENTAL MOISTURE AND PERSISTENT FORCING...CONDITIONS WILL BE FAVORABLE FOR SOME LOCATIONS TO SEE RAINFALL AMOUNTS OF HALF AND INCH OR SO. DEE .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 341 AM CDT FRI MAY 1 2015 SFC BNDRY AT THIS POINT PROGGED TO BECOME NEARLY STATIONARY MONDAY MORNING THRU TUESDAY MORNING. PERSISTENT INFLUX OF GULF MOISTURE COUPLED WITH MOIST BNDRY LYR CONVERGENCE/INSTABILITY AXIS SITUATED OVER THE CWA WOULD SUGGEST CONDITIONS WILL AGAIN BE FAVORABLE FOR SIGNIFICANT RAINFALL ACCUMULATIONS. TUESDAY AFTN THRU THURSDAY NIGHT PCPN ACCUMULATIONS BEING DRIVEN BY EXTENDED PERIOD OF 305K UPGLIDE/PRESIDENT LLVL MOISTURE ADVECTION. OTHERWISE...METEOGRAMS STILL SHOWING MODERATE COOL NEXT WEEK IN LIGHT OF SFC BNDRY MOVING IN. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 620 AM CDT FRI MAY 1 2015 SOME CEILINGS AROUND 5000 FEET AND VSBYS IN THE MVFR CATEGORY WILL BE POSSIBLE INTO THIS EVENING WITH SCATTERED SHRA. DID NOT MENTION THUNDER WITH THE 12Z TAFS BECAUSE ANYTHING SHOULD BE ISOLATED. WE CAN AMEND THE TAFS IF CONFIDENCE INCREASES. WINDS WILL BE MAINLY LESS THAN 12 KNOTS. .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER/DEE LONG TERM...DEE AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
345 AM CDT FRI MAY 1 2015 .SHORT TERM...(TODAY) ISSUED AT 341 AM CDT FRI MAY 1 2015 PCPN CHANCES/PCPN COVERAGE AND TEMPERATURES WILL PROVIDE THE MAIN FORECAST CHALLENGES FOR THE TODAY PERIOD. REGIONAL RADAR LOOP EARLY THIS MORNING SHOWED SHOWERS AND A FEW EMBEDDED THUNDERSTORMS OCCURRING IN ASSOCIATION WITH A WEAK COLD FRONT MOVING EASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS. THIS FRONT SHOULD STALL OUT AND THEN WASH OUT THIS EVENING. LATEST SHORT RANGE HIGH RESOLUTION MODELS ARE IN DECENT AGREEMENT SHOWING SOME SCATTERED AND MAINLY LIGHT PCPN MOVING ACROSS THE FORECAST AREA THIS MORNING. 06Z RAP SEEMED TO HAVE A FAIRLY GOOD HANDLE ON THE PATTERN. LOOK FOR HIGHS MOSTLY IN THE LOWER AND MID 70S BUT A FEW LOCATIONS IN WEST CENTRAL IOWA MAY ONLY REACH NEAR 70. .SHORT TERM...(TONIGHT THROUGH SUNDAY) ISSUED AT 341 AM CDT FRI MAY 1 2015 FOCUS FOR POSSIBLE PCPN SHIFTS TO THE SRN CWA TONIGHT AND SATURDAY MORNING WHERE 310K UPGLIDE AND LOW COND PRES DEF WILL BE MOST PREVALENT. NEXT ROUND OF PCPN ASSOCIATED WITH A COLD FRONT DROPPING THRU THE DAKOTAS/UPPER MID WEST SATURDAY NIGHT THE INTO THE CWA ON SUNDAY. MODELS HOLD OFF DEVELOPMENT UNTIL AFTN WHEN ENVIRONMENT BECOMES ADEQUATELY UNSTABLE...THEN INCREASES IN AREAL COVERAGE AND INTENSITY SUNDAY NIGHT IN RESPONSE TO STRENGTHENING BNDRY LYR MOISTURE CONVERGENCE. WITH RELATIVELY HIGH CONCENTRATION OF ENVIRONMENTAL MOISTURE AND PERSISTENT FORCING...CONDITIONS WILL BE FAVORABLE FOR SOME LOCATIONS TO SEE RAINFALL AMOUNTS OF HALF AND INCH OR SO. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 341 AM CDT FRI MAY 1 2015 SFC BNDRY AT THIS POINT PROGGED TO BECOME NEARLY STATIONARY MONDAY MORNING THRU TUESDAY MORNING. PERSISTENT INFLUX OF GULF MOISTURE COUPLED WITH MOIST BNDRY LYR CONVERGENCE/INSTABILITY AXIS SITUATED OVER THE CWA WOULD SUGGEST CONDITIONS WILL AGAIN BE FAVORABLE FOR SIGNIFICANT RAINFALL ACCUMULATIONS. TUESDAY AFTN THRU THURSDAY NIGHT PCPN ACCUMULATIONS BEING DRIVEN BY EXTENDED PERIOD OF 305K UPGLIDE/PRESIDENT LLVL MOISTURE ADVECTION. OTHERWISE...METEOGRAMS STILL SHOWING MODERATE COOL NEXT WEEK IN LIGHT OF SFC BNDRY MOVING IN. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1144 PM CDT THU APR 30 2015 FORECAST REASONING REMAINS FROM PREVIOUS TAF CYCLE. VFR CONDITIONS ARE EXPECTED TO CONTINUE. ISOLATED TO SCATTERED SHOWERS AND A POSSIBLE RUMBLE OF THUNDER SHOULD MOVE INTO THE AREA FROM LATE OVERNIGHT/EARLY MORNING THROUGH THE AFTERNOON...BUT COVERAGE CONCERNS PRECLUDES MENTION AT THIS TIME. SOUTHEAST WINDS WILL BECOME SOUTHWESTERLY...WITH SPEEDS AT OR BELOW 10KT. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ TONIGHT...BCM SHORT TERM...DEE LONG TERM...DEE AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 PM EDT FRI MAY 1 2015 .SYNOPSIS...AN UPPER LEVEL LOW AND ASSOCIATED SURFACE LOW WILL MOVE EAST OF THE AREA TONIGHT...AS HIGH PRESSURE AND MORE SEASONABLE CONDITIONS SPREAD IN FOR THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 320 PM FRIDAY... WATER VAPOR AND LATEST RAP DATA SUGGEST THE UPPER LOW IS NOW OVER THE PAMLICO SOUND AND CONTINUING TO DRIFT EAST...WHILE THE STRONGEST ASSOCIATED VORTICITY IS NOW OVER SOUTHEASTERN NC. MOIST NORTHEASTERLY FLOW...30-35KT AT 850MB...AND ISENTROPIC LIFT OVER THE NORTHERN COASTAL PLAIN HAS GIVEN WAY TO SOME ISENTROPIC DOWNGLIDE THIS AFTERNOON PER RAP ANALYSIS. THE STEEPER LAPSE RATES THAT WERE OVER CENTRAL NC THIS MORNING HAVE ALSO SHIFTED SOUTH/EAST...AND WITH THE LOSS OF BETTER FORCING/LAPSE RATES...SHOWERS HAVE BECOME MORE SCATTERED ACROSS THE NORTHERN PIEDMONT/COASTAL PLAIN OVER THE PAST COUPLE HOURS. THERE ARE SOME ADDITIONAL SMALL DISTURBANCES IN THE CYCLONIC FLOW ALOFT THAT SHOULD AID SHOWER ACTIVITY FOR A FEW MORE HOURS...MOST NOTABLY WITH AN AREA OF SHOWERS MOVING SOUTH THROUGH SOUTHWESTERN VA. THE LATEST HRRR SHOWS THIS CONVECTION REACHING THE TRIAD AROUND 21Z BUT DWINDLING BEFORE MOVING MUCH FURTHER SOUTHEAST AS HEATING...WHAT LITTLE WE HAVE HAD...IS LOST. WILL TREND POPS DOWN FROM WEST TO EAST FOR MOST OF THE AREA...KEEPING A CHANCE POP ACROSS THE WEST THROUGH 00Z. TONIGHT...SKIES WILL BEGIN TO CLEAR WITHIN THE SUBSIDENCE BEHIND THE UPPER LOW...THOUGH GUIDANCE IS IN PRETTY GOOD AGREEMENT ON SOME LINGERING MOISTURE NEAR 5K FT...WHICH SHOULD ALSO DRIFT SOUTHEAST WITH TIME AS THE LOW LEVEL FLOW CONTINUES TO BACK AROUND TO MORE NORTHERLY. A LIGHT WIND WILL CONTINUE OVER THE COASTAL PLAIN...BUT BUT TO THE WEST SOME PATCHY FOG SEEMS POSSIBLE GIVEN LITTLE CHANGE IN AIRMASS AND LIGHT WINDS/DRYING ALOFT. SREF PROBABILITIES FOR FOG ARE NOT VERY HIGH...SO DENSE FOG IS NOT EXPECTED. LOWS IN THE UPPER 40S. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 320 PM FRIDAY... ONE LAST RIBBON OF VORTICITY IS EXPECTED TO DROP SOUTH ACROSS THE COASTAL PLAIN AROUND MIDDAY...AND ALL MODELS SHOW A SIGNAL FOR AT LEAST ISOLATED SHOWERS WITH SOME SHALLOW INSTABILITY BEFORE THE ATMOSPHERE DRIES OUT MORE SUBSTANTIALLY AND STRONGER SUBSIDENCE SETS IN. WILL KEEP THE SLIGHT CHANCE POP FROM ROUGHLY ROXBORO TO CLINTON THROUGH MID AFTERNOON. HIGHS 72-76 NORTHEAST TO SOUTHWEST. HIGHS PRESSURE WILL FINALLY BUILD OVERHEAD SATURDAY NIGHT AND SKIES WILL FULLY CLEAR. DESPITE THE GOOD RADIATIONAL COOLING CONDITIONS...THE AIRMASS ACTUALLY MODIFIES SLIGHTLY AND LOWS WILL BE COMPARABLE TO TONIGHT...IF NOT WARMER IN SOME SPOTS WITH UPPER 40S AND LOWER 50S. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 240 PM FRIDAY... HIGH PRESSURE OVERHEAD ON SUNDAY WILL SLOWLY MIGRATE OFFSHORE BUT CONTINUE TO RIDGE WESTWARD INTO NC THROUGH TUESDAY. A WEAK TROUGH WILL GET SANDWICHED BETWEEN THE EXITING HIGH AND A HIGH OVER THE GREAT LAKES MID-WEEK. ALTHOUGH SOME OF THE MODELS INDICATE A SLIGHT CHANCE FOR SOME SHOWERS IN THE FAR NORTHWEST DURING THE AFTERNOON PERIODS MON-WED...MOST OF THE SHOWER ACTIVITY SHOULD STAY WELL TO THE NORTH AND NORTHWEST. CENTRAL NC WILL REMAIN UNDER HIGH PRESSURE BUT GENERALLY WEAK SURFACE FLOW FOR THE REMAINDER OF THE WEEK. WEDNESDAY THROUGH FRIDAY GETS INTERESTING TO OUR SOUTHEAST AS BOTH THE GFS AND ECMWF GENERATE A TROPICAL LOW PRESSURE SYSTEM OVER THE CARIBBEAN...MOVING SLOWLY NORTH AND STALLING OFF THE CAROLINA COAST. WHILE THERE IS STILL A GOOD DEAL OF UNCERTAINTY WITH THIS SYSTEM GIVEN THAT IT IS FAR OUT IN THE MODEL FORECAST PERIOD...THE FACT THAT BOTH MODELS SHOW SIMILAR FEATURES INCREASES THE CHANCE THAT SOMETHING OF INTEREST WILL DEVELOP OFF THE SOUTHEAST ATLANTIC COAST TOWARD THE END OF THE WEEK. REGARDLESS...ITS EVOLUTION WILL BE SOMETHING TO WATCH. AS FOR TEMPERATURES...STILL EXPECT OUR FIRST EXTENDED PERIOD OF 80 DEGREE DAYS...WITH HIGHS INCREASING ABOUT A DEGREE OR SO A DAY FROM THE MID TO UPPER 70S ON SUNDAY INTO THE LOW TO MID 80S BY FRIDAY. LOWS WILL SEE A SIMILAR TREND...INCREASING FROM THE MID 50S SUNDAY NIGHT INTO THE UPPER 50S TO LOW 60S BY FRIDAY NIGHT. SKIES WILL GENERALLY BE CLEAR TO PARTLY CLOUDY THROUGH MOST OF THE PERIOD...WITH FAIRLY LIGHT WINDS...EXCEPT IN THE SOUTHEAST AS THAT LOW HANGS OFF THE CAROLINA COAST. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 200 PM FRIDAY... DESPITE THE CONTINUED AREAS OF LIGHT RAIN MOVING FROM NNE TO SSW ACROSS THE AREA TODAY...CEILINGS HAVE BEEN ABLE TO LIFT A BIT INTO THE MVFR RANGE...WITH SOME VFR CONDITIONS AT TIMES ACROSS THE WESTERN PIEDMONT AREA. THE UPPER LOW THAT IS RESPONSIBLE FOR THE PRECIP WILL CONTINUE TO SLOWLY MOVE EAST THIS AFTERNOON AND EVENING...EVENTUALLY BRINGING MOST OF THE SHOWERS TO AN FROM WEST TO EAST IN THE 20Z TO 00Z TIME FRAME. HOWEVER..THERE IS A SLIGHT CHANCE OF SOME SOME ADDITIONAL SHOWERS CURRENTLY NEAR ROANOKE VA MOVING SOUTH TOWARD THIS TRIAD AROUND 21Z...WHICH COULD BRING ANOTHER SHORT PERIOD OF MVFR CEILINGS/VSBYS TO KGSO/KINT...BUT THESE ARE EXPECTED TO DWINDLE BY SUNSET AND NOT IMPACT ANY SITES TO THE EAST. MEANWHILE...CEILINGS WILL LIFT TO VFR AND REMAIN MOSTLY VFR THROUGH TONIGHT AND INTO THE WEEKEND. AS THE CLOUDS LIFT AND THIN...SOME LOW VSBYS MAY DEVELOP AFTER MIDNIGHT...WITH SREF PROBABILITIES INDICATING AREA FROM KRDU TO KFAY HAVING THE BEST CHANCE OF MAINLY MVFR VSBYS. HOWEVER...IF WINDS ARE LIGHT ENOUGH BEHIND THE DEPARTING LOW AND SKIES CLEAR...SOME DENSE FOG CANT BE RULED OUT. OUTLOOK... VFR CONDITIONS LIKELY SAT MORNING THROUGH TUE... AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST... SHIFTING OVERHEAD LATE IN THE WEEKEND AND MOVING OFFSHORE EARLY NEXT WEEK. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...22 NEAR TERM...22 SHORT TERM...22 LONG TERM...KC AVIATION...HARTFIELD/22
AREA FORECAST DISCUSSION
NWS RALEIGH NC
240 PM EDT FRI MAY 1 2015 .SYNOPSIS...LOW PRESSURE WILL LINGER OVER AND JUST OFF THE CAROLINA COAST TODAY... AS A STRONG UPPER LEVEL DISTURBANCE CROSSES THE REGION. THE LOW AND DISTURBANCE WILL MOVE OFFSHORE LATE TONIGHT... AND HIGH PRESSURE WILL BUILD IN FROM THE WEST OVER THE WEEKEND. && .NEAR TERM /TODAY/... AS OF 1030 AM FRIDAY... THE INTENSITY OF THE RAIN OVER THE CENTRAL PIEDMONT EARLIER THIS MORNING HAS DECREASED AS IT PUSHES SOUTH INTO THE SOUTHERN PIEDMONT AND SANDHILLS. AN UPPER LOW WITHIN A LARGER POSITIVELY TILTED UPPER TROUGH IS ROTATING OVERHEAD...AND THE MAIN LOBE OF STRONG VORTICITY RESPONSIBLE FOR THAT BATCH OF RAIN IS SHIFTING MORE TOWARD SC AND SOUTHEAST NC. MORNING OBS ANALYSIS SHOWS ANOTHER...WEAKER SHORTWAVE NORTH OF THE LOW THAT WILL ROTATE OUR WAY THIS AFTERNOON...ALONG WITH 30-35KT OF 850MB FLOW THAT WILL ENHANCE LOW-LEVEL CONVERGENCE. SPC TROPOSPHERIC LAPSE RATES ARE STILL RELATIVELY STEEP WITHIN THE UPPER LOW...WITH AN AXIS AREA OF NEAR -7C STRETCHING FROM WSW TO ENE ACROSS THE AREA....SO SOME WEAK INSTABILITY MAY DEVELOP AGAIN THIS AFTERNOON...THOUGH THE WIDESPREAD AND CONTINUED FEED OF RAIN FROM THE NORTHEAST WILL LIKELY INHIBIT WARMING MORE THAN YESTERDAY. THUS...EXPECT MAINLY SHOWERS THIS AFTERNOON BECOMING INCREASINGLY FOCUSED EAST OF US 1. THE LATEST HRRR SHOWS SOME DEEPER CONVECTION FIRING ACROSS THE SOUTHERN COASTAL PLAIN AFTER 18Z...AND WITH THE FREEZING LEVEL BELOW 6K FT ON THE KGSO RAOB AND THE -10C TO -20C LAYER CENTERED AROUND 15K FT...SOME SMALL HAIL CANT BE COMPLETELY RULED OUT. HOWEVER...THE PROBABILITY SEEMS VERY LOW AT THIS POINT. CURRENT TEMP FORECAST LOOKS PRETTY REASONABLE WITH LIMITED WARMING...STRONGEST ACROSS THE SOUTHERN PIEDMONT THIS AFTERNOON AS PRECIP MOVES OFF TO THE EAST....WITH UPPER 50S NORTHEAST TO SOME MID 60S SOUTHWEST. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... AS OF 255 AM FRIDAY... TONIGHT: EXPECT SLOW CLEARING WITH MODEST BUT DEEP SUBSIDENCE AND DRYING IN THE WAKE OF THE EXITING LOW. SURFACE WINDS WILL BECOME FAIRLY LIGHT FROM THE NNW WHILE 950-850 MB WINDS WILL BE MAINLY FROM THE NNE... ALLOWING ATLANTIC MOISTURE TO CONTINUE TO SPILL IN ON THE NW SIDE OF THE LOW... SO SCATTERED STRATOCU MAY LINGER WELL INTO THE NIGHT. LOWS 45-50 WITH WEAK COOL AIR ADVECTION AS SURFACE HIGH PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST... BUT INITIALLY GETS HELD UP BY THE MOUNTAINS. SAT/SAT NIGHT: MOSTLY DRY AND QUIET WEATHER IS EXPECTED. A BAND OF ISOLATED SHOWERS IS EXPECTED OVER THE NRN/ERN PORTIONS OF CENTRAL NC IN THE AFTERNOON... AS A NOSE OF ENHANCED PW AND WEAK VORTICITY DROPS TO THE SSE AROUND THE WEST SIDE OF THE OFFSHORE LOW. MOISTURE IS UNIMPRESSIVE HOWEVER... WITH VERY SMALL FORECAST MUCAPE... SO WILL MAINTAIN JUST ISOLATED COVERAGE... FOCUSED ON THE NW PIEDMONT AND NRN/CENTRAL COASTAL PLAIN... AS SUGGESTED BY THE HI-RES WRF MODEL RUNS. EXPECT MOSTLY CLEAR SKIES SAT NIGHT WITH WINDS BECOMING LIGHT/VARIABLE AS THE CENTER OF THE SURFACE HIGH SHIFTS OVERHEAD. HIGHS 71-76 NE TO SW... AND LOWS IN THE UPPER 40S TO LOWER 50S. -GIH && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 240 PM FRIDAY... HIGH PRESSURE OVERHEAD ON SUNDAY WILL SLOWLY MIGRATE OFFSHORE BUT CONTINUE TO RIDGE WESTWARD INTO NC THROUGH TUESDAY. A WEAK TROUGH WILL GET SANDWICHED BETWEEN THE EXITING HIGH AND A HIGH OVER THE GREAT LAKES MID-WEEK. ALTHOUGH SOME OF THE MODELS INDICATE A SLIGHT CHANCE FOR SOME SHOWERS IN THE FAR NORTHWEST DURING THE AFTERNOON PERIODS MON-WED...MOST OF THE SHOWER ACTIVITY SHOULD STAY WELL TO THE NORTH AND NORTHWEST. CENTRAL NC WILL REMAIN UNDER HIGH PRESSURE BUT GENERALLY WEAK SURFACE FLOW FOR THE REMAINDER OF THE WEEK. WEDNESDAY THROUGH FRIDAY GETS INTERESTING TO OUR SOUTHEAST AS BOTH THE GFS AND ECMWF GENERATE A TROPICAL LOW PRESSURE SYSTEM OVER THE CARIBBEAN...MOVING SLOWLY NORTH AND STALLING OFF THE CAROLINA COAST. WHILE THERE IS STILL A GOOD DEAL OF UNCERTAINTY WITH THIS SYSTEM GIVEN THAT IT IS FAR OUT IN THE MODEL FORECAST PERIOD...THE FACT THAT BOTH MODELS SHOW SIMILAR FEATURES INCREASES THE CHANCE THAT SOMETHING OF INTEREST WILL DEVELOP OFF THE SOUTHEAST ATLANTIC COAST TOWARD THE END OF THE WEEK. REGARDLESS...ITS EVOLUTION WILL BE SOMETHING TO WATCH. AS FOR TEMPERATURES...STILL EXPECT OUR FIRST EXTENDED PERIOD OF 80 DEGREE DAYS...WITH HIGHS INCREASING ABOUT A DEGREE OR SO A DAY FROM THE MID TO UPPER 70S ON SUNDAY INTO THE LOW TO MID 80S BY FRIDAY. LOWS WILL SEE A SIMILAR TREND...INCREASING FROM THE MID 50S SUNDAY NIGHT INTO THE UPPER 50S TO LOW 60S BY FRIDAY NIGHT. SKIES WILL GENERALLY BE CLEAR TO PARTLY CLOUDY THROUGH MOST OF THE PERIOD...WITH FAIRLY LIGHT WINDS...EXCEPT IN THE SOUTHEAST AS THAT LOW HANGS OFF THE CAROLINA COAST. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 200 PM FRIDAY... DESPITE THE CONTINUED AREAS OF LIGHT RAIN MOVING FROM NNE TO SSW ACROSS THE AREA TODAY...CEILINGS HAVE BEEN ABLE TO LIFT A BIT INTO THE MVFR RANGE...WITH SOME VFR CONDITIONS AT TIMES ACROSS THE WESTERN PIEDMONT AREA. THE UPPER LOW THAT IS RESPONSIBLE FOR THE PRECIP WILL CONTINUE TO SLOWLY MOVE EAST THIS AFTERNOON AND EVENING...EVENTUALLY BRINGING MOST OF THE SHOWERS TO AN FROM WEST TO EAST IN THE 20Z TO 00Z TIME FRAME. HOWEVER..THERE IS A SLIGHT CHANCE OF SOME SOME ADDITIONAL SHOWERS CURRENTLY NEAR ROANOKE VA MOVING SOUTH TOWARD THIS TRIAD AROUND 21Z...WHICH COULD BRING ANOTHER SHORT PERIOD OF MVFR CEILINGS/VSBYS TO KGSO/KINT...BUT THESE ARE EXPECTED TO DWINDLE BY SUNSET AND NOT IMPACT ANY SITES TO THE EAST. MEANWHILE...CEILINGS WILL LIFT TO VFR AND REMAIN MOSTLY VFR THROUGH TONIGHT AND INTO THE WEEKEND. AS THE CLOUDS LIFT AND THIN...SOME LOW VSBYS MAY DEVELOP AFTER MIDNIGHT...WITH SREF PROBABILITIES INDICATING AREA FROM KRDU TO KFAY HAVING THE BEST CHANCE OF MAINLY MVFR VSBYS. HOWEVER...IF WINDS ARE LIGHT ENOUGH BEHIND THE DEPARTING LOW AND SKIES CLEAR...SOME DENSE FOG CANT BE RULED OUT. OUTLOOK... VFR CONDITIONS LIKELY SAT MORNING THROUGH TUE... AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST... SHIFTING OVERHEAD LATE IN THE WEEKEND AND MOVING OFFSHORE EARLY NEXT WEEK. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD/22 SHORT TERM...HARTFIELD LONG TERM...KC AVIATION...HARTFIELD/22
AREA FORECAST DISCUSSION
NWS RALEIGH NC
200 PM EDT FRI MAY 1 2015 .SYNOPSIS...LOW PRESSURE WILL LINGER OVER AND JUST OFF THE CAROLINA COAST TODAY... AS A STRONG UPPER LEVEL DISTURBANCE CROSSES THE REGION. THE LOW AND DISTURBANCE WILL MOVE OFFSHORE LATE TONIGHT... AND HIGH PRESSURE WILL BUILD IN FROM THE WEST OVER THE WEEKEND. && .NEAR TERM /TODAY/... AS OF 1030 AM FRIDAY... THE INTENSITY OF THE RAIN OVER THE CENTRAL PIEDMONT EARLIER THIS MORNING HAS DECREASED AS IT PUSHES SOUTH INTO THE SOUTHERN PIEDMONT AND SANDHILLS. AN UPPER LOW WITHIN A LARGER POSITIVELY TILTED UPPER TROUGH IS ROTATING OVERHEAD...AND THE MAIN LOBE OF STRONG VORTICITY RESPONSIBLE FOR THAT BATCH OF RAIN IS SHIFTING MORE TOWARD SC AND SOUTHEAST NC. MORNING OBS ANALYSIS SHOWS ANOTHER...WEAKER SHORTWAVE NORTH OF THE LOW THAT WILL ROTATE OUR WAY THIS AFTERNOON...ALONG WITH 30-35KT OF 850MB FLOW THAT WILL ENHANCE LOW-LEVEL CONVERGENCE. SPC TROPOSPHERIC LAPSE RATES ARE STILL RELATIVELY STEEP WITHIN THE UPPER LOW...WITH AN AXIS AREA OF NEAR -7C STRETCHING FROM WSW TO ENE ACROSS THE AREA....SO SOME WEAK INSTABILITY MAY DEVELOP AGAIN THIS AFTERNOON...THOUGH THE WIDESPREAD AND CONTINUED FEED OF RAIN FROM THE NORTHEAST WILL LIKELY INHIBIT WARMING MORE THAN YESTERDAY. THUS...EXPECT MAINLY SHOWERS THIS AFTERNOON BECOMING INCREASINGLY FOCUSED EAST OF US 1. THE LATEST HRRR SHOWS SOME DEEPER CONVECTION FIRING ACROSS THE SOUTHERN COASTAL PLAIN AFTER 18Z...AND WITH THE FREEZING LEVEL BELOW 6K FT ON THE KGSO RAOB AND THE -10C TO -20C LAYER CENTERED AROUND 15K FT...SOME SMALL HAIL CANT BE COMPLETELY RULED OUT. HOWEVER...THE PROBABILITY SEEMS VERY LOW AT THIS POINT. CURRENT TEMP FORECAST LOOKS PRETTY REASONABLE WITH LIMITED WARMING...STRONGEST ACROSS THE SOUTHERN PIEDMONT THIS AFTERNOON AS PRECIP MOVES OFF TO THE EAST....WITH UPPER 50S NORTHEAST TO SOME MID 60S SOUTHWEST. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... AS OF 255 AM FRIDAY... TONIGHT: EXPECT SLOW CLEARING WITH MODEST BUT DEEP SUBSIDENCE AND DRYING IN THE WAKE OF THE EXITING LOW. SURFACE WINDS WILL BECOME FAIRLY LIGHT FROM THE NNW WHILE 950-850 MB WINDS WILL BE MAINLY FROM THE NNE... ALLOWING ATLANTIC MOISTURE TO CONTINUE TO SPILL IN ON THE NW SIDE OF THE LOW... SO SCATTERED STRATOCU MAY LINGER WELL INTO THE NIGHT. LOWS 45-50 WITH WEAK COOL AIR ADVECTION AS SURFACE HIGH PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST... BUT INITIALLY GETS HELD UP BY THE MOUNTAINS. SAT/SAT NIGHT: MOSTLY DRY AND QUIET WEATHER IS EXPECTED. A BAND OF ISOLATED SHOWERS IS EXPECTED OVER THE NRN/ERN PORTIONS OF CENTRAL NC IN THE AFTERNOON... AS A NOSE OF ENHANCED PW AND WEAK VORTICITY DROPS TO THE SSE AROUND THE WEST SIDE OF THE OFFSHORE LOW. MOISTURE IS UNIMPRESSIVE HOWEVER... WITH VERY SMALL FORECAST MUCAPE... SO WILL MAINTAIN JUST ISOLATED COVERAGE... FOCUSED ON THE NW PIEDMONT AND NRN/CENTRAL COASTAL PLAIN... AS SUGGESTED BY THE HI-RES WRF MODEL RUNS. EXPECT MOSTLY CLEAR SKIES SAT NIGHT WITH WINDS BECOMING LIGHT/VARIABLE AS THE CENTER OF THE SURFACE HIGH SHIFTS OVERHEAD. HIGHS 71-76 NE TO SW... AND LOWS IN THE UPPER 40S TO LOWER 50S. -GIH && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 230 AM FRIDAY... THE LONG TERM WILL FEATURE WARM AND DRY CONDITIONS WITH OUR FIRST REAL STRETCH OF 80 DEGREE DAYS OF THE YEAR. THE PATTERN WILL FEATURE SURFACE HIGH PRESSURE OFFSHORE WITH WEAK SOUTHERLY RETURN FLOW ACROSS CENTRAL NC. THE NORTHWESTERLIES ALOFT WILL WEAKEN CONSIDERABLY TO VERY LIGHT WINDS FOR THE FIRST HALF OF THE WEEK. IN FACT THE GFS FORECAST SOUNDING FOR GREENSBORO ON MONDAY AFTERNOON HAS LESS THAN 10 KTS OF WIND ALL THE WAY UP THROUGH 200 MB. WHILE THE TEMPERATURES WILL FEEL VERY WARM IN CONTRAST TO WHAT WE HAVE BEEN EXPERIENCING THIS PAST WEEK...THE LOW TO MID 80S WILL ONLY BE ABOUT 5 DEGREES ABOVE NORMAL FOR THIS TIME OF THE YEAR AND NOT EVEN CLOSE TO APPROACHING RECORDS AS THESE ARE ALL IN THE LOW TO MID 90S. LOWS WILL BE IN THE UPPER 50S TO LOW 60S. NOT MUCH IN THE WAY OF PRECIPITATION IS EXPECTED DURING THE PERIOD BUT SOME CONVECTION ASSOCIATED WITH A TROUGH NORTHWEST OF THE AREA COULD IMPINGE ON THE TRIAD ON WEDNESDAY AND THURSDAY AFTERNOONS BUT COVERAGE...AND DURATION SHOULD BE MINIMAL AS MOST ACTIVITY SHOULD REMAIN NORTH OF THE AREA. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 200 PM FRIDAY... DESPITE THE CONTINUED AREAS OF LIGHT RAIN MOVING FROM NNE TO SSW ACROSS THE AREA TODAY...CEILINGS HAVE BEEN ABLE TO LIFT A BIT INTO THE MVFR RANGE...WITH SOME VFR CONDITIONS AT TIMES ACROSS THE WESTERN PIEDMONT AREA. THE UPPER LOW THAT IS RESPONSIBLE FOR THE PRECIP WILL CONTINUE TO SLOWLY MOVE EAST THIS AFTERNOON AND EVENING...EVENTUALLY BRINGING MOST OF THE SHOWERS TO AN FROM WEST TO EAST IN THE 20Z TO 00Z TIME FRAME. HOWEVER..THERE IS A SLIGHT CHANCE OF SOME SOME ADDITIONAL SHOWERS CURRENTLY NEAR ROANOKE VA MOVING SOUTH TOWARD THIS TRIAD AROUND 21Z...WHICH COULD BRING ANOTHER SHORT PERIOD OF MVFR CEILINGS/VSBYS TO KGSO/KINT...BUT THESE ARE EXPECTED TO DWINDLE BY SUNSET AND NOT IMPACT ANY SITES TO THE EAST. MEANWHILE...CEILINGS WILL LIFT TO VFR AND REMAIN MOSTLY VFR THROUGH TONIGHT AND INTO THE WEEKEND. AS THE CLOUDS LIFT AND THIN...SOME LOW VSBYS MAY DEVELOP AFTER MIDNIGHT...WITH SREF PROBABILITIES INDICATING AREA FROM KRDU TO KFAY HAVING THE BEST CHANCE OF MAINLY MVFR VSBYS. HOWEVER...IF WINDS ARE LIGHT ENOUGH BEHIND THE DEPARTING LOW AND SKIES CLEAR...SOME DENSE FOG CANT BE RULED OUT. OUTLOOK... VFR CONDITIONS LIKELY SAT MORNING THROUGH TUE... AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST... SHIFTING OVERHEAD LATE IN THE WEEKEND AND MOVING OFFSHORE EARLY NEXT WEEK. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD/22 SHORT TERM...HARTFIELD LONG TERM...ELLIS AVIATION...HARTFIELD/22
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1034 AM EDT FRI MAY 1 2015 .SYNOPSIS...LOW PRESSURE WILL LINGER OVER AND JUST OFF THE CAROLINA COAST TODAY... AS A STRONG UPPER LEVEL DISTURBANCE CROSSES THE REGION. THE LOW AND DISTURBANCE WILL MOVE OFFSHORE LATE TONIGHT... AND HIGH PRESSURE WILL BUILD IN FROM THE WEST OVER THE WEEKEND. && .NEAR TERM /TODAY/... AS OF 1030 AM FRIDAY... THE INTENSITY OF THE RAIN OVER THE CENTRAL PIEDMONT EARLIER THIS MORNING HAS DECREASED AS IT PUSHES SOUTH INTO THE SOUTHERN PIEDMONT AND SANDHILLS. AN UPPER LOW WITHIN A LARGER POSITIVELY TILTED UPPER TROUGH IS ROTATING OVERHEAD...AND THE MAIN LOBE OF STRONG VORTICITY RESPONSIBLE FOR THAT BATCH OF RAIN IS SHIFTING MORE TOWARD SC AND SOUTHEAST NC. MORNING OBS ANALYSIS SHOWS ANOTHER...WEAKER SHORTWAVE NORTH OF THE LOW THAT WILL ROTATE OUR WAY THIS AFTERNOON...ALONG WITH 30-35KT OF 850MB FLOW THAT WILL ENHANCE LOW-LEVEL CONVERGENCE. SPC TROPOSPHERIC LAPSE RATES ARE STILL RELATIVELY STEEP WITHIN THE UPPER LOW...WITH AN AXIS AREA OF NEAR -7C STRETCHING FROM WSW TO ENE ACROSS THE AREA....SO SOME WEAK INSTABILITY MAY DEVELOP AGAIN THIS AFTERNOON...THOUGH THE WIDESPREAD AND CONTINUED FEED OF RAIN FROM THE NORTHEAST WILL LIKELY INHIBIT WARMING MORE THAN YESTERDAY. THUS...EXPECT MAINLY SHOWERS THIS AFTERNOON BECOMING INCREASINGLY FOCUSED EAST OF US 1. THE LATEST HRRR SHOWS SOME DEEPER CONVECTION FIRING ACROSS THE SOUTHERN COASTAL PLAIN AFTER 18Z...AND WITH THE FREEZING LEVEL BELOW 6K FT ON THE KGSO RAOB AND THE -10C TO -20C LAYER CENTERED AROUND 15K FT...SOME SMALL HAIL CANT BE COMPLETELY RULED OUT. HOWEVER...THE PROBABILITY SEEMS VERY LOW AT THIS POINT. CURRENT TEMP FORECAST LOOKS PRETTY REASONABLE WITH LIMITED WARMING...STRONGEST ACROSS THE SOUTHERN PIEDMONT THIS AFTERNOON AS PRECIP MOVES OFF TO THE EAST....WITH UPPER 50S NORTHEAST TO SOME MID 60S SOUTHWEST. && .SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/... AS OF 255 AM FRIDAY... TONIGHT: EXPECT SLOW CLEARING WITH MODEST BUT DEEP SUBSIDENCE AND DRYING IN THE WAKE OF THE EXITING LOW. SURFACE WINDS WILL BECOME FAIRLY LIGHT FROM THE NNW WHILE 950-850 MB WINDS WILL BE MAINLY FROM THE NNE... ALLOWING ATLANTIC MOISTURE TO CONTINUE TO SPILL IN ON THE NW SIDE OF THE LOW... SO SCATTERED STRATOCU MAY LINGER WELL INTO THE NIGHT. LOWS 45-50 WITH WEAK COOL AIR ADVECTION AS SURFACE HIGH PRESSURE ATTEMPTS TO BUILD IN FROM THE WEST... BUT INITIALLY GETS HELD UP BY THE MOUNTAINS. SAT/SAT NIGHT: MOSTLY DRY AND QUIET WEATHER IS EXPECTED. A BAND OF ISOLATED SHOWERS IS EXPECTED OVER THE NRN/ERN PORTIONS OF CENTRAL NC IN THE AFTERNOON... AS A NOSE OF ENHANCED PW AND WEAK VORTICITY DROPS TO THE SSE AROUND THE WEST SIDE OF THE OFFSHORE LOW. MOISTURE IS UNIMPRESSIVE HOWEVER... WITH VERY SMALL FORECAST MUCAPE... SO WILL MAINTAIN JUST ISOLATED COVERAGE... FOCUSED ON THE NW PIEDMONT AND NRN/CENTRAL COASTAL PLAIN... AS SUGGESTED BY THE HI-RES WRF MODEL RUNS. EXPECT MOSTLY CLEAR SKIES SAT NIGHT WITH WINDS BECOMING LIGHT/VARIABLE AS THE CENTER OF THE SURFACE HIGH SHIFTS OVERHEAD. HIGHS 71-76 NE TO SW... AND LOWS IN THE UPPER 40S TO LOWER 50S. -GIH && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 230 AM FRIDAY... THE LONG TERM WILL FEATURE WARM AND DRY CONDITIONS WITH OUR FIRST REAL STRETCH OF 80 DEGREE DAYS OF THE YEAR. THE PATTERN WILL FEATURE SURFACE HIGH PRESSURE OFFSHORE WITH WEAK SOUTHERLY RETURN FLOW ACROSS CENTRAL NC. THE NORTHWESTERLIES ALOFT WILL WEAKEN CONSIDERABLY TO VERY LIGHT WINDS FOR THE FIRST HALF OF THE WEEK. IN FACT THE GFS FORECAST SOUNDING FOR GREENSBORO ON MONDAY AFTERNOON HAS LESS THAN 10 KTS OF WIND ALL THE WAY UP THROUGH 200 MB. WHILE THE TEMPERATURES WILL FEEL VERY WARM IN CONTRAST TO WHAT WE HAVE BEEN EXPERIENCING THIS PAST WEEK...THE LOW TO MID 80S WILL ONLY BE ABOUT 5 DEGREES ABOVE NORMAL FOR THIS TIME OF THE YEAR AND NOT EVEN CLOSE TO APPROACHING RECORDS AS THESE ARE ALL IN THE LOW TO MID 90S. LOWS WILL BE IN THE UPPER 50S TO LOW 60S. NOT MUCH IN THE WAY OF PRECIPITATION IS EXPECTED DURING THE PERIOD BUT SOME CONVECTION ASSOCIATED WITH A TROUGH NORTHWEST OF THE AREA COULD IMPINGE ON THE TRIAD ON WEDNESDAY AND THURSDAY AFTERNOONS BUT COVERAGE...AND DURATION SHOULD BE MINIMAL AS MOST ACTIVITY SHOULD REMAIN NORTH OF THE AREA. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... AS OF 655 AM FRIDAY... MVFR TO IFR CONDITIONS WILL DOMINATE CENTRAL NC TAFS THROUGH THIS MORNING... FOLLOWED BY SLOW IMPROVEMENT TO VFR MID-LATE FRI AFTERNOON (AFTER 20Z). A STRONG UPPER LEVEL LOW MOVING OVER THE REGION THROUGH TODAY WILL BRING UNSETTLED WEATHER WITH MVFR CIGS COMMON AT ALL SITES... AND PERIODS OF VFR-MVFR VSBYS IN SHOWERS... FROM MORNING THROUGH THE MID AFTERNOON HOURS. CIGS MAY DROP TO IFR FOR A FEW HOURS EARLY THIS MORNING BETWEEN 07Z AND 13Z. AN ISOLATED THUNDERSTORM OR TWO IS ALSO POSSIBLE ESPECIALLY AT THE EASTERN TERMINALS OF RDU/RWI/FAY 14Z-20Z TODAY... BUT THE THUNDER COVERAGE SHOULD BE TOO LOW TO MENTION IN THE TAFS. WINDS WILL INCREASE THIS MORNING FROM THE NORTH OR NE AT 10-14 KTS GUSTING UP TO 20 KTS... THEN DROP BACK UNDER 10 KTS AFTER 22Z. VFR CONDITIONS ARE LIKELY THIS EVENING ON THROUGH TONIGHT. LOOKING BEYOND 12Z SAT MORNING: VFR CONDITIONS LIKELY SAT MORNING THROUGH TUE... AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE WEST... SHIFTING OVERHEAD LATE IN THE WEEKEND AND MOVING OFFSHORE EARLY NEXT WEEK. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD/22 SHORT TERM...HARTFIELD LONG TERM...ELLIS AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
147 AM EDT FRI MAY 1 2015 .SYNOPSIS... THE PASSAGE OF A STRONG UPPER LEVEL DISTURBANCE LATE IN THE DAY WILL FINALLY KICK LOW PRESSURE ALONG THE NORTH CAROLINA COAST WELL OFFSHORE...ENDING THE RISK FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD ACROSS THE AREA FOR THE WEEKEND AND INTO THE FIRST PART OF NEXT WEEK. THE DRY WEATHER AND RETURNING SUNSHINE WILL ALLOW TEMPERATURES TO RETURN TO SEASONABLE LEVELS BY THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1015 PM THURSDAY...SHOWERS BREAKING OUT ACROSS THE FORECAST AREA AS AN UPPER DISTURBANCE DROPS SE ACROSS THE CAROLINAS. SOME LIGHTNING BEING DETECTED OVER PENDER COUNTY BUT OTHERWISE WE ARE SEEING JUST ISOLATED TO WIDELY SCATTERED SHOWER ACTIVITY. OTHER THAN THE LIGHTNING THIS ACTIVITY IS FAIRLY BENIGN AND WILL CONTINUE ON AND OFF THROUGH THE EVENING HOURS. FORECAST IN GOOD SHAPE...PREVIOUS DISCUSSION FOLLOWS: LOW PRESSURE CENTERED SOUTH OF CAPE HATTERAS SHOULD SLOW TONIGHT AS A POWERFUL UPPER LEVEL DISTURBANCE DIVES SOUTHWARD FROM INDIANA INTO NORTH CAROLINA. ALTHOUGH LOW- LEVEL BAROCLINICITY IS VERY WEAK...A FAVORABLY ORIENTED JET STREAK OFFSHORE PLUS INCOMING VORTICITY WITH THE DISTURBANCE SHOULD LEAD TO SLOWLY FALLING PRESSURES OFFSHORE. AWAY FROM EXTREME EASTERN NC (INCLUDING WILMINGTON) THERE HAS BEEN PLENTY OF SUNSHINE TODAY. TEMPERATURES RISING INTO THE 70S PLUS RATHER COOL TEMPERATURES ALOFT HAVE HELPED GENERATE SURFACE-BASED CAPE AS LARGE AS 500 J/KG ALONG AND WEST OF I-95. SO FAR THIS HAS RESULTED IN AN EXPANSIVE CUMULUS FIELD ACROSS WESTERN NC PLUS A SMATTERING OF SHOWERS. AS 800-600 MB TEMPERATURES FALL FURTHER THIS EVENING AND THE FIRST OF SEVERAL UPPER DISTURBANCES ARRIVES FROM THE WEST...THE POTENTIAL FOR SHOWERS WILL EXPAND ACROSS SOUTHEASTERN NORTH CAROLINA AND NORTHERN PORTIONS OF THE PEE DEE REGION. I HAVE DECIDED NOT TO INCLUDE THUNDER IN THE FORECAST AS IT APPEARS AN INVERSION BETWEEN 500-600 MB SHOULD BE SUFFICIENTLY STRONG TO CAP OFF UPDRAFTS BEFORE THEY BECOME COLD ENOUGH ALOFT. 12Z MODELS HAVE BACKED OFF A LITTLE COMPARED TO THEIR 00Z/06Z COUNTERPARTS WITH THE SOUTHERN EXTENT OF PRECIPITATION...AND THIS TREND IS ECHOED BY THE LAST FEW HRRR RUNS AS WELL. BY LATE TONIGHT THE MAIN UPPER LOW WILL WOBBLE INTO CENTRAL NORTH CAROLINA. NEAR AND NORTH OF THE LOW IS WHERE UNSTABLE CONDITIONS SHOULD CONTINUE OVERNIGHT DUE TO COLD AIR ALOFT. OUR FORECAST AREA SHOULD LARGELY REMAIN SOUTH OF THE INSTABILITY...SO ASIDE FROM MAINTAINING 30-40 PERCENT POPS ACROSS LUMBERTON-ELIZABETHTOWN-BURGAW I HAVE CUT POPS TO 10-20 POPS OVERNIGHT...WITH LOWS GENERALLY IN THE LOWER 50S EXCEPT MID 50S AT THE BEACHES. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...A STRONG UPPER LOW WILL CUT BY TO OUR NORTH ON FRIDAY. EVEN SO WE SHOULD SEE VERY STRONG PVA AND HEIGHT FALLS LOCALLY AND SOME LIGHT SHOWERS SEEM LIKELY OVER NORTHERN ZONES. STILL TOUGH TO RULE OUT THUNDER WITH UPWARDS OF 600J/KG OF CAPE DEVELOPING. SOME OF THIS INSTABILITY MAY GO SUFFICIENTLY INTO THE HAIL GROWTH LAYER FOR SOME PEA SIZED HAIL TO REACH THE GROUND UNDERNEATH THE DEEPER CONVECTIVE CELLS. CLOUD COVER WILL MEANWHILE BRING ONE LAST DAY OF CONSIDERABLY COOL TEMPS WITH HIGHS STUCK IN THE 60S. DRY AIR MOVES IN FRIDAY NIGHT INTO SATURDAY. THERE IS HOWEVER ONE TRAILING VORT AND WRAPAROUND MOISTURE ON SATURDAY AND SOME GUIDANCE HINTING AT PRECIP OVER CAPE FEAR/COASTAL NC ZONES. FEEL IF ANYTHING AT ALL WILL BE JUST NON-MEASURABLE AND HAVE KEPT THE FORECAST DRY AT THIS TIME. THE DECREASED CLOUD COVER WILL ALLOW FOR A NICE BUMP IN TEMPERATURES COME SATURDAY BUT THE NORTHERLY FLOW COMPONENT THROUGH A DEEP LAYER WILL STILL KEEP US A TAD BELOW CLIMO. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 300 PM THURSDAY...BERMUDA HIGH AND MID LEVEL RIDGE BUILDING OVER THE SOUTHEAST WILL KEEP THE REGION DRY DURING THE PERIOD WITH TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO. AS FAR AS THE TROPICAL WAVE/LOW COMBO EMERGING FROM THE BAHAMAS NEXT WEEK GOES THE LATEST MEDIUM RANGE GUIDANCE HAS FALLEN OUT OF FAVOR WITH THIS SCENARIOS. NEARLY ALL OF THE GUIDANCE (INCLUDING THE ENSEMBLES) NOW SHOW A SHEARED OUT SURFACE WAVE MOVING EAST-NORTHEAST...REMAINING WELL SOUTHEAST OF THE COAST. LATER IN THE PERIOD CANNOT RULE OUT AN ISOLATED SEA BREEZE SHOWER AS LOW LEVEL MOISTURE INCREASES BUT COVERAGE WILL BE QUITE LIMITED AND DOES NOT WARRANT INCLUSION OF POP GREATER THAN 15 AT THIS TIME. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 06Z...SHOWERS WILL TEND TO INCREASE EARLY THIS MORNING MAINLY KILM TO KLBT AS A STRONG UPPER LOW APPROACHES. THERE IS MODERATE CONFIDENCE IFR WILL DEVELOP AT KLBT/KILM/KCRE. IFR IS POSSIBLE AT KMYR AND KFLO AROUND SUNRISE...BUT CONFIDENCE IS HIGHER CIGS WILL BE MVFR WITH ANY IFR OF A SHORT TEMPO DURATION. GENERALLY CIGS WILL IMPROVE TO MVFR THEN VFR DURING THE MORNING HOURS AS WINDS BECOME NW 10-12 KT. SHOWERS WILL CONTINUE...BUT STILL MOST LIKELY NEAR KILM. VFR EXPECTED IN THE AFTERNOON...BUT MVFR CIGS WILL BECOME POSSIBLE AGAIN WITH BEST CONFIDENCE OF OCCURRENCE AT KILM AND KLBT. WINDS WILL BE NW-N FRIDAY...GUSTING TO 20-25 KT BY AFTERNOON. WINDS DECREASE AFTER 23-00Z AS SKIES BECOME SCT. EXTENDED OUTLOOK...VFR THROUGH THE EXTENDED PERIOD. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1015 PM THURSDAY...NO CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: LOW PRESSURE HAS MOVED SOUTH OF HATTERAS THIS AFTERNOON BUT SHOULD SLOW TONIGHT AS A STRONG UPPER LEVEL DISTURBANCE APPROACHES FROM THE WEST. THIS DISTURBANCE WILL CREATE A ZONE OF WEAKENED PRESSURE GRADIENT ACROSS EASTERN NORTH CAROLINA TONIGHT...WHILE TO THE SOUTH ACROSS SOUTH CAROLINA THE GRADIENT SHOULD GRADUALLY TIGHTEN WITH INCREASING WESTERLY WINDS EXPECTED. BY DAYBREAK WINDS JUST EAST OF WINYAH BAY/GEORGETOWN COULD REACH 15-20 KT. THE VARIOUS COMPUTER MODELS HAVE DIFFERING POSITIONS OF WHERE THE BOUNDARY BETWEEN THESE STRONGER WEST WINDS AND LIGHTER NORTH WINDS CLOSER TO THE LOW WILL SET UP...AND I HAVE FOLLOWED THE 12Z GFS AS A GUIDE TONIGHT. SEAS CURRENTLY RANGE FROM 2-3 FEET INSIDE 20 MILES OF SHORE...TO 4 FEET OUT AT THE FRYING PAN SHOALS BUOY. SEAS MAY SUBSIDE A BIT THIS EVENING BUT SHOULD INCREASE AGAIN OVERNIGHT...ESPECIALLY SOUTH OF CAPE FEAR...DUE TO THE INCREASING WIND SPEEDS. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 300 PM THURSDAY...LOW PRESSURE OFF CAPE HATTERAS WILL BE SLOW TO MOVE ON FRIDAY, ENERGIZED IN PART BY A STRONG LOW IN THE MID LEVELS. THIS FEATURE WILL STRENGTHEN VERTICAL MIXING MORE THAN THE ACTUAL SURFACE PRESSURE GRADIENT, POSSIBLY ENOUGH FOR SOME ADVISORY-WORTHY 25KT WINDS OVER MAINLY JUST OUR NORTHERNMOST ZONE- MAINLY FRIDAY NIGHT. ALL MODELS ARE NOT CONVINCED OF THIS AND THERE IS STILL A BIT OF TIME TO IRON OUT THE UNCERTAINTY SO ONE WILL NOT BE RAISED AT THIS TIME. THE LOW WILL BE GRADUALLY PULLING AWAY TO THE NORTHEAST ON SATURDAY. WINDS LOCALLY WILL REMAIN N TO NW AND SLOWLY SUBSIDE. THERE MAY EVEN BE A BIT OF BACKSWELL FROM THE OFFSHORE STORM AS IT GROWS A BIT LARGER IN SIZE. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 300 PM THURSDAY...SURFACE HIGH MOVING OFF THE COAST SUN MORNING WILL SETUP NEAR BERMUDA SUN EVENING AND REMAIN IN PLACE THROUGH THE END OF THE PERIOD. LIGHT AND VARIABLE WINDS ON SUN...WITH SEA BREEZE DOMINATING NEAR SHORE FLOW...WILL BECOME SOUTHEAST TO SOUTH MON AND TUE. GRADIENT WILL REMAIN ON THE WEAK SIDE WITH SPEEDS GENERALLY 10 KT OR LESS. DAILY SEA BREEZE WILL RESULT IN A SLIGHT BUMP IN SPEEDS NEAR SHORE IN THE AFTERNOON. SEAS AROUND 2 FT WILL BE MAINTAINED THROUGH THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...REK/TRA SHORT TERM...MBB LONG TERM...III AVIATION...RJD/MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
259 AM CDT FRI MAY 1 2015 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 259 AM CDT FRI MAY 1 2015 PRECIP THIS MORNING AND AGAIN SATURDAY AFTERNOON WILL BE THE MAIN CONCERNS...ALONG WITH WIND TODAY FOR FIRE WEATHER. NEAR ZONAL FLOW ALOFT SETS UP AS THE UPPER RIDGE PUSHES OFF TO THE EAST. THE SFC TROUGH OVER THE CWA THIS MORNING WILL MOVE SOUTHEASTWARD TODAY AND WASH OUT...LEAVING RELATIVELY LIGHTER WEST WINDS. RAINFALL OVER THE EASTERN COUNTIES WILL MOVE OUT OF THE AREA SHORTLY AFTER 12Z. THERE WILL BE A PERIOD BEFORE THE WESTERLY WINDS START TO PICK UP BUT AFTER CLOUDS CLEAR OUT. WITH RECENT RAINFALL SOME RADIATION FOG HAS DEVELOPED IN THE NORTHWESTERN CWA. IT IS SOMEWHAT PATCHY...WITH KDVL SHOWING 10SM RIGHT NOW. EXPANDED THE FOG MENTION IN THE GRIDS BUT GIVEN THE PATCHY NATURE WILL JUST KEEP AN EYE ON WEB CAMS AND OBS FOR NOW AND HOLD OFF ON ANY DENSE FOG ADVISORIES. WITH WESTERLY WINDS TODAY WE SHOULD DRY OUT NICELY BY AFTERNOON AND TEMPS WILL AGAIN WARM INTO THE 70S ALTHOUGH NOT AS WARM AS YESTERDAY. DRY CONDITIONS WILL AGAIN BE AN ISSUE BUT WINDS WILL BE MUCH LESS TODAY...AROUND 10 KTS IN THE VALLEY AND EASTWARD...WITH MAX OF LESS THAN 15 KTS IN THE NORTHWESTERN COUNTIES. THERE SHOULD BE A DEEP ADIABATIC LAYER...BUT MODEL SOUNDINGS FOR KDVL SHOW AT MOST A 10 TO 15 KTS AT THE TOP...SO THINK THAT GUSTINESS WILL NOT BE TOO HIGH. THE SOUTH WINDS WILL CONTINUE TO SLOWLY RAMP UP INTO TONIGHT AS SFC LOW PRESSURE DEVELOPS ALONG THE SASKATCHEWAN/MANITOBA BORDER. THE WINDS SHOULD HELP TEMPS FRIDAY NIGHT TO STAY IN THE UPPER 40S TO NEAR 50 DEGREES. SATURDAY...A DECENT SHORTWAVE TROUGH MOVES INTO SASKATCHEWAN...WITH THE SFC TROUGH AXIS PUSHING INTO CENTRAL ND. TEMPS WILL BE VERY WARM WITH THE THERMAL RIDGE OVER THE AREA...AND WITH DECENT MIXING HIGHS COULD GET INTO THE LOW 80S IN SOME AREAS. SFC DEWPOINTS WILL BE INCREASING...WITH PWAT VALUES UP TO AND EVEN ABOVE 1 INCH. THERE COULD BE SOME CAPE VALUES NEAR 1000 J/KG AND WITH DEEP LAYER BULK SHEAR VALUES OF 45 TO 50 KTS SOME MARGINAL SEVERE STORMS ARE POSSIBLE. HAVE POPS STARTING OUT SLOW IN THE WEST DURING THE EARLY AFTERNOON BUT RAMPING UP LATE SATURDAY TOWARDS SATURDAY NIGHT. .LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 259 AM CDT FRI MAY 1 2015 SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE UPPER SHORTWAVE WILL MOVE FROM MANITOBA INTO ONTARIO...BRINGING A COLD FRONT DOWN THROUGH THE NORTHERN PLAINS. THERE SHOULD BE SOME GOOD THUNDERSTORM ACTIVITY ALONG THE FRONT OVER THE SOUTHERN AND EASTERN COUNTIES AT THE START OF THE PERIOD...AND MODELS SHOW ACTIVITY CONTINUING INTO SUNDAY BEFORE THE BOUNDARY PUSHES OFF TO THE SOUTHEAST SUNDAY NIGHT. KEPT THE HIGHEST POPS IN THE SOUTH AND EAST...BUT SOME MODELS SHOW SOME ADDITIONAL DEVELOPMENT FURTHER BACK BEHIND THE FRONT TOWARDS SUNDAY MORNING. TEMPS WILL BE MILD SATURDAY NIGHT THANKS TO CLOUDS AND PRECIP. HIGHS ON SUNDAY WILL BE QUITE A BIT COOLER THAN SATURDAY ALTHOUGH STILL ABOVE AVERAGE IN THE 60S TO LOW 70S...DROPPING DOWN INTO THE UPPER 30S TO 40S SUNDAY NIGHT. MONDAY THROUGH THURSDAY...THE UPPER LEVEL FLOW WILL SHIFT TO A SOUTHWEST FLOW PATTERN FOR THE LONG TERM AND BRING AN INCREASED CHANCE FOR PRECIPITATION...ESPECIALLY DURING THE MIDWEEK. MODELS ARE INDICATING AN OPEN GULF WITH AMPLE MOISTURE TO BRING SHOWERS AND CONVECTION THROUGHOUT THE CNTRL PLAINS AND NORTHERN TIER OF THE CONUS. HOWEVER...THERE ARE STILL DIFFERENCES ON PLACEMENT AND TIMING OF CYCLONE AND WILL REMOVE ANY LIKELY POPS AT THIS TIME ALTHOUGH THERE IS A HIGH LIKELIHOOD IN THE WED/THU TIMEFRAME. DAYTIME HIGHS WILL GENERALLY BE IN THE 60S AND 70S WITH A LITTLE MORE HUMIDITY THAN WE HAVE SEEN THE LAST COUPLE OF WEEKS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1144 PM CDT THU APR 30 2015 RAIN SHOWER BAND MOVING EAST AS EXPECTED WITH VFR CIGS. SKIES CLEARING QUICKY BEHIND IT WITH SKY CLEAR AT DVL NOW AND SKIES WILL CLEAR OVERNIGHT INTO THE RRV AND REACH BJI AREA MID MORNING. QUESTION WILL BE FOG POTENTIAL. CLEAR SKY BEHIND LINE AND LIGHT WINDS AFTER SOME LIGHT RAIN MEANS SOME FOG POTENTIAL. HRRR MODEL SHOWS SOME AND THREW IN SOME MVFR VSBYS FOR BR INTO TVF/DVL/GFK OVERNIGHT AS THAT MODELS SHOWS A BETTER CHC IN THIS AREA. AS USUAL WITH RADIATIONAL FOG DEVELOPMENT AND COVERAGE/INTENSITY IS UNCERTAIN. SKIES WILL BE CLEAR ON FRIDAY WITH A WEST WIND NR 10 KTS. && .FIRE WEATHER... ISSUED AT 259 AM CDT FRI MAY 1 2015 A VERY DRY AIRMASS WILL REMAIN IN PLACE IN THE CENTRAL AND WESTERN DAKOTAS FRIDAY. LIGHT RAIN SHOWERS DEVELOPED IN FAR EASTERN ND AND MOVED ACROSS NW AND W CNTRL MN THIS EVENING...BUT THE DVL REGION RECEIVED LITTLE IF ANY PRECIP. DEWPOINTS THIS AFTERNOON WILL BE IN THE UPPER TEENS. HOWEVER...WHILE A DEEP ADIABATIC LAYER WILL SET UP BY 21Z...WINDS THROUGHOUT THE COLUMN ARE ON THE ORDER OF 10 KTS. FURTHER WEST...COLUMN WINDS ARE AROUND 20KTS AT MINOT. NEAR CRITICAL FIRE WEATHER CONDITIONS WILL EXIST IN THE DEVILS LAKE REGION UP THROUGH LANGDON...BUT THE HIGHER THREAT WILL BE ACROSS WESTERN AND N CNTRL ND AND WILL HOLD OFF ON A RED FLAG WARNING DUE TO WEAK FLOW. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...JR LONG TERM...JR/SPEICHER AVIATION...RIDDLE FIRE WEATHER...SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1214 AM CDT FRI MAY 1 2015 .UPDATE... ISSUED AT 1211 AM CDT FRI MAY 1 2015 LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH EXITING THE JAMES RIVER VALLEY AT THIS TIME...WITH RAIN SHOWERS EXPECTED TO DIMINISH AND END ACROSS THE SOUTHERN JAMES RIVER VALLEY BY 07Z. SURFACE OBSERVATIONS AND SATELLITE SHOW FOG JUST EAST OF THE TURTLE MOUNTAINS...WITH THE LATEST HRRR LOW VISIBILITY FORECAST JUST GRAZING ROLETTE AND POSSIBLY PIERCE COUNTIES OVERNIGHT...SO HAVE ADDED IN PATCHY FOG. OTHERWISE CLEAR FORECAST WITH HIGH CLOUDS APPROACHING THE NORTHWEST AND NORTH CENTRAL OVERNIGHT. CONCERN FOR FRIDAY AFTERNOON WILL BE FIRE WEATHER AND WILL BE FOCUSING ON THIS FOR THE NEXT UPDATE. UPDATE ISSUED AT 956 PM CDT THU APR 30 2015 FORECAST FOR THE REMAINDER OF THE NIGHT REMAINS ON TRACK AS THE COLD FRONT HAS EXITED INTO THE RED RIVER VALLEY. FOLLOWING TRENDS IN THE 00-01 UTC HRRR ITERATIONS...POST-FRONTAL RAIN SHOWERS ARE EXPECTED TO CONTINUE ACROSS THE JAMES RIVER VALLEY THROUGH 06-07 UTC. UPDATE ISSUED AT 704 PM CDT THU APR 30 2015 QUICK UPDATE TO EXPIRE THE RED FLAG WARNING ON TIME AT 00 UTC. AS OF 00 UTC...THE SURFACE COLD FRONT WAS LOCATED FROM FAR NORTHEAST NORTH DAKOTA THROUGH LAKE OAHE...WITH LIGHT RAIN ALONG AND BEHIND THE FRONT. HOWEVER...A SIGNIFICANT PORTION OF THIS PRECIPITATION WAS NOT REACHING THE GROUND ACROSS THE SOUTH CENTRAL. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 244 PM CDT THU APR 30 2015 MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE FIRE WEATHER CONCERNS THIS AFTERNOON...AND AGAIN FRIDAY AFTERNOON. CURRENTLY...A COLD FRONT IS SITUATED FROM AROUND BOTTINEAU TO BISMARCK. AHEAD OF THE FRONT...SOUTHERLY WINDS 15 TO 20 MPH WITH GUSTS OF 25 TO 30 MPH. THIS IS RESULTING IN MINIMUM HUMIDITIES AROUND 25 PERCENT FROM SOUTHEAST EMMONS COUNTY...TO THE UPPER TEENS OVER THE JAMES RIVER VALLEY. CRITICAL FIRE WEATHER CRITERIA IS MARGINAL OVER THE THE WESTERN PORTION OF THE WARNING BUT WINDS WILL INITIALLY BE GUSTY BEHIND THE FRONT...SO ALTHOUGH HUMIDITIES WILL RISE WITH THE FRONTAL PASSAGE...WILL KEEP THE RED FLAG WARNING IN EFFECT UNTIL AFTER THE FRONTAL PASSAGE WHEN WINDS DIMINISH AND HUMIDITIES RISE. WILL KEEP THE MENTION OF AFTERNOON THUNDER...ALTHOUGH CHANCES WILL BE MINIMAL. TONIGHT...SHOWERS WILL END ACROSS CENTRAL NORTH DAKOTA THIS EVENING...WITH MOSTLY CLEAR SKIES DEVELOPING WEST TO EAST OVERNIGHT. LOWS WILL BE IN THE MID 30S WEST TO MID 40S SOUTHEAST. FRIDAY...MOSTLY SUNNY AND CONTINUED MILD FRIDAY BEHIND THE FRONT WITH A WEST TO SOUTHWEST SURFACE FLOW. BUFR SOUNDINGS INDICATE SUSTAINED WINDS 15 TO 20 MPH FRIDAY AFTERNOON WITH GUSTS OF 25 TO 30 MPH...ACROSS THE NORTHWEST AND NORTH CENTRAL. WITH MINIMUM HUMIDITIES AROUND 20 PERCENT...CRITICAL FIRE WEATHER CONDITIONS WILL BE POSSIBLE. WILL ISSUE A FIRE WEATHER WATCH FOR PORTIONS OF THE WEST CENTRAL..THE NORTHWEST AND NORTH CENTRAL 18Z FRIDAY TO 00Z SATURDAY. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 244 PM CDT THU APR 30 2015 CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS THROUGH THE WEEKEND WITH THE POTENTIAL FOR CONSIDERABLE RAIN BY MID WEEK...HIGHLIGHTS THE LONG TERM. THE CURRENT MODEL PACKAGE PROVIDES GOOD AGREEMENT ON AN UPPER LEVEL TROUGH DEVELOPING AND MOVING EASTWARD ACROSS THE CENTRAL CANADIAN PLAINS THROUGH THE WEEKEND. SHOWERS AND THUNDERSTORMS ARE POSSIBLE AHEAD OF THE ASSOCIATED SURFACE FRONT. THE GREATEST CHANCES FOR THUNDERSTORM ACTIVITY LOOK TO BE IN THE SOUTHEAST. THEREAFTER...ZONAL FLOW ALOFT WILL TRANSITION TO SOUTHWESTERLY FLOW AHEAD OF AN UPPER LEVEL TROUGH DIGGING INTO THE PACIFIC NORTHWEST...EARLY NEXT WEEK. AS A RESULT...LEE TROUGHING IS EXPECTED AT THE SURFACE WITH MOISTURE TRANSPORT AND ATMOSPHERIC INSTABILITY CREATING WIDESPREAD CHANCES FOR SHOWERS AND THUNDERSTORMS. ALTHOUGH MODELS HAVE SHOWN CONSISTENT AGREEMENT ON OVERALL PRECIPITATION DEVELOPMENT...TIMING/LOCATION REMAINS UNCERTAIN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1211 AM CDT FRI MAY 1 2015 VFR CIGS/VSBYS NEXT 24HR. EXPECT SOUTHWEST WINDS TO AROUND 25KT AT KISN/KMOT/KDIK FRIDAY AFTERNOON. && .BIS WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM THIS AFTERNOON THROUGH THIS EVENING FOR NDZ001>005-009>013-017>019-021-031-032. && $$ UPDATE...KS SHORT TERM...TWH LONG TERM...AC AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1148 PM CDT THU APR 30 2015 .UPDATE... ISSUED AT 1144 PM CDT THU APR 30 2015 COLD FRONT ENTERING ERN FCST AREA NEAR A WARROAD TO FOSSTON TO NEAR WAHPETON LINE. AREA OF SHOWERS JUST WEST OF FRONT MOVIGN EAST AS WELL. ONE BIT HEAVIER BATCH LIFTED INTO MANITOBA AND A BIT HEAVIER RAIN AREA (MAYBE UP TO 0.25) SOUTHWEST OF FARGO. OTHERWISE RAINFALL IS LIGHT (AROUND 0.05 OR SO). SKIES CLEAR QUICKYL BEHIND SHOWER BAND. QUESTION IS FOG IN CLEARING LATER TONIGHT. LATEST HRRR HINTS AS SOME LOWER VSBYS IN NRN VALLEY OVERNGITH AND LAST OBS FROM LANGDON ND (KD55) SHOWS SOME BR ALREADY. SO WILL THROW IN SOME PATCHY FOG TO MAINLY NRN VALLEY OVERNIGHT. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT) ISSUED AT 347 PM CDT THU APR 30 2015 A PROGRESSIVE PATTERN WAS ACROSS THE STATES IN A ZONAL FLOW. UPPER LEVEL JET MOVING INTO SOUTHWEST CANADA WILL MOVE ACROSS SOUTHERN MANITOBA FRI THROUGH SUN. UPPER LEVEL TROUGH OVER MT WILL MOVE ACROSS THE FORECAST AREA TONIGHT. PRECIPITATION WAS GENERALLY IN THE 700 HPA THETA-E RIDGE OR THE GRADIENT. PRECIPITABLE WATER WILL RISE TO NEAR AN INCH OVERNIGHT OR EAST OF THE FRONT. FRONT/WIND SHIFT WILL MOVE THROUGH FORECAST AREA TONIGHT THEN WASH OUT. RETURN FLOW TO OCCUR FRI. NEXT TROUGH OVER THE GULF OF AK WILL MOVE ACROSS SOUTHERN CANADA ON SUN. TROUGH WILL SEND ANOTHER COLD FRONT ACROSS THE FORECAST AREA SAT AFTERNOON AND SAT NIGHT. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 347 PM CDT THU APR 30 2015 FOR SUNDAY NIGHT THROUGH THURSDAY...THE PERIOD WILL START OUT DRY TO START THE WEEK. MODELS ARE COMING INTO BETTER AGREEMENT WITH INCREASING CHANCES FOR SHOWERS AND SOME THUNDER WED/THU. PWATS WILL RISE TO AROUND 1.30 INCHES...ALONG WITH SOME ELEVATED INSTABILITY WITH SHOWALTERS SLIGHTLY NEGATIVE AND STRONG MOISTURE TRANSPORT. THIS WOULD BE BENEFICIAL RAIN THAT COULD TOTAL AN INCH OR MORE PERHAPS IN SOME AREAS FOR WED THROUGH THU. TEMPS SHOULD BE ABOVE NORMAL THROUGH THE PERIOD WITH SOME COOLING BY WED/THU WITH MORE CLOUDS/PRECIP. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1144 PM CDT THU APR 30 2015 RAIN SHOWER BAND MOVING EAST AS EXPECTED WITH VFR CIGS. SKIES CLEARING QUICKY BEHIND IT WITH SKY CLEAR AT DVL NOW AND SKIES WILL CLEAR OVERNIGHT INTO THE RRV AND REACH BJI AREA MID MORNING. QUESTION WILL BE FOG POTENTIAL. CLEAR SKY BEHIND LINE AND LIGHT WINDS AFTER SOME LIGHT RAIN MEANS SOME FOG POTENTIAL. HRRR MODEL SHOWS SOME AND THREW IN SOME MVFR VSBYS FOR BR INTO TVF/DVL/GFK OVERNIGHT AS THAT MODELS SHOWS A BETTER CHC IN THIS AREA. AS USUAL WITH RADIATIONAL FOG DEVELOPMENT AND COVERAGE/INTENSITY IS UNCERTAIN. SKIES WILL BE CLEAR ON FRIDAY WITH A WEST WIND NR 10 KTS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...RIDDLE SHORT TERM...HOPPES LONG TERM...DK AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
139 AM EDT FRI MAY 1 2015 .SYNOPSIS... VIGOROUS MID/UPPER LOW PRESSURE CROSSES TO OUR SOUTHEAST TONIGHT. INSTABILITY SHOWERS THEN LINGERING LOWER CLOUDS/SHOWERS OVERNIGHT. HIGH PRESSURE FOR THE WEEKEND...WITH A WARMING TREND INTO NEXT WEEK. && .NEAR TERM /THROUGH TODAY/... 800 PM UPDATE... NOT MUCH CHANGE IN THE FCST WITH THE EVE UPDATE. FINESSED POPS USING LATEST HRRR AS A BASE WHICH PIVOTS BANDS OF SHRA THRU OVERNIGHT ACROSS S ZONES. PREVIOUS DISCUSSION BELOW... AN UPPER LEVEL LOW PRESSURE SYSTEM DROPS SOUTH INTO OH TONIGHT...TURNING SOUTHEAST ACROSS EASTERN KY OVERNIGHT. SCATTERED SHOWERS ARE NOTED ALONG THE PERIPHERY OF THIS CIRCULATION WITH EMBEDDED THUNDERSTORMS SOUTH AND WEST OF ITS CENTER. TONIGHT THE WEATHER REMAINS UNSETTLED WITH LIGHT SHOWERS DRIFTING EAST. FEW THUNDERSTORMS CAN BE POSSIBLE ACROSS THE EXTREME SOUTHERN PORTIONS OF WV...NORTHEAST OH...AND SOUTHWEST VA TONIGHT. AS THE LOW EXITS SOUTHEAST...IMPROVING CONDITIONS WILL SPREAD FROM WEST TO EAST EARLY FRIDAY. MODELS SUGGEST THAT ABUNDANT LINGERING MOISTURE WILL PROVIDE FOR LOW LEVEL CLOUDS OVERNIGHT INTO EARLY FRIDAY. BUFKIT SOUNDINGS INDICATE DRIER AIR FILTERS IN FROM THE WEST LATE FRIDAY...PERHAPS BRINGING PERIODS OF SUNSHINE DURING THE AFTERNOON HOURS ACROSS SOUTHEAST OH. WITH ABUNDANT CLOUDINESS...TEMPERATURES TONIGHT WILL BE IN THE 40S. FRIDAY...TEMPERATURES WILL RANGE FROM THE MID 60S LOWLANDS...INTO THE MID 50S HIGHEST ELEVATIONS. WENT CLOSER TO THE COOLER BIAS CORRECTED ECMWF FOR LOWS TONIGHT...AND WITH THE CONSENSUS RAW FOR HIGHS ON FRIDAY. && .SHORT TERM /TONIGHT THROUGH SUNDAY/... INSTABILITY AND LOW LEVEL UPSLOPE FLOW WANE FRI EVENING WITH LOSS OF HEATING AND UPPER LEVEL TROUGH PULLING AWAY. ANY MOUNTAIN SHOWERS WILL DIE OFF BY MIDNIGHT AS A RESULT. OTHERWISE HIGH PRESSURE SAILS SLOWLY ACROSS THE AREA THIS WEEKEND TO PROVIDE NICE WEATHER. UPPER LEVEL RIDGING BUILDS TO THE W OF THE FCST AREA...BUT A WEAK S/W TROUGH CROSSING LATE SAT AND AN EVEN WEAKER ONE LATE SUNDAY WILL BRING SOME MID AND HIGH CLOUD...AND THERE WILL ALSO BE SOME AFTERNOON CU...SO THE DAYTIME HOURS WILL BRING A MIX OF CLOUDS AND SUNSHINE. LEFT THE SCHC FOR A SHOWER IN THE WV MOUNTAINS SAT AFTERNOON ON ELEVATED HEATING...ALTHOUGH THE AREA MAY BE UNDERNEATH WEAK RIDGING BETWEEN THE EXITING UPPER LEVEL TROUGH...AND THE S/W COMING FROM THE W WHICH CROSSES SAT AFTERNOON AND NT. TEMPERATURES ARE CLOSE TO GUIDANCE AND NORMAL IN THIS RELATIVELY TRANQUIL PATTERN...EXCEPT HIGHS SAT WERE A LITTLE ABOVE GUIDANCE AND WERE LEFT ALONE IN LIGHT OF EARLY MAY SUNSHINE. TRIED TO TWEAK HIGHS SUNDAY UPWARD TOWARD THE LATEST MEX...AGAIN IN TH EARLY MAY SUN. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... USED THE ECMWF ENSEMBLE MEAN AS THE BASIS FOR THE FORECAST. THIS WOULD HAVE HIGH PRESSURE IN CONTROL FOR SUNDAY NIGHT AND MONDAY. WITH THE HIGH SLIDING EASTWARD...MOISTURE INCREASES. THIS MAY ALLOW FOR SOME AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ON TUESDAY. BY WEDNESDAY...A FRONTAL BOUNDARY ATTEMPTS TO SLIDE INTO SOUTHEAST OHIO AND NORTHERN WEST VIRGINIA BEFORE RETURNING BACK NORTHWARD ON THURSDAY. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... UPPER LEVEL LOW IS ROTATING SLOWLY TO THE SOUTH WHILE SATURATING THE LOWER LEVELS OF THE ATMOSPHERE. ALSO...SHOWERS ARE PRESENT OVER THE MOUNTAINS...AND WILL BE DEVELOPING OVER THE NORTHERN LOWLANDS. FORECAST SOUNDINGS SHOW THE POTENTIAL FOR MVFR TO IFR CEILINGS AS WE GO TOWARDS 12Z THIS MORNING. THIS DECREASES CONFIDENCE IN THE OVERALL FORECAST. FIGURE VISIBILITIES WILL NOT BE A CONSISTENT ISSUE WITH CLOUDS AND BRIEF SHOWER ACTIVITY...ALONG WITH A LIGHT WIND REMAINING IN PLACE. MOUNTAINS WILL HAVE THE POSSIBILITY OF THUNDER IN THE VICINITY DURING THE AFTERNOON HOURS FRIDAY. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SATURDAY... FORECAST CONFIDENCE: MEDIUM. ALTERNATE SCENARIOS: LOWERING CEILING TONIGHT MAY NOT DEVELOP...OR MAY NEED MORE EXTENSIVE IFR. AMENDMENTS MAY BE NEEDED. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE FRI 05/01/15 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY M M H M M M L H H H M M HTS CONSISTENCY M M H H H M M H H H H H BKW CONSISTENCY H H H H H H H H H H M M EKN CONSISTENCY L L L L H H H H H H H H PKB CONSISTENCY M M M L H M H M M M M H CKB CONSISTENCY H H H H H H H H M M M H AFTER 06Z SATURDAY... NO WIDESPREAD IFR CONDITIONS EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ARJ/TRM/RPY NEAR TERM...ARJ/30/26 SHORT TERM...TRM LONG TERM...RPY AVIATION...26
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
258 PM EDT FRI MAY 1 2015 .SHORT TERM...(TONIGHT THROUGH SUNDAY)...SEEING MOSTLY CLOUDS THIS AFTERNOON ACROSS THE NE HALF OF THE FORECAST AREA. NO SHOWERS AS OF YET WITH A MORE STABLE AIRMASS THAN EXPECTED. LATEST HRRR MODEL RUN WOULD ONLY BRING A STRAY SHOWER THIS EVENING TO OUR FAR NE CORNER SO POPS WERE DROPPED ELSEWHERE...WITH A SLIGHT CHANCE OF SHOWERS MENTIONED FOR RUSSELL/WASHINGTON VA COUNTIES AND OUR NE TN MTNS. SLOWED DOWN THE DECREASE IN CLOUDS JUST A BIT...AND KEPT THE PATCHY AREAS OF FOG FROM PREVIOUS GRIDS FOR LATE TONIGHT AROUND THE LAKES & STREAMS. UPPER AND SURFACE RIDGING STILL LOOKS TO BRING US AN AWESOME WEEKEND WITH DRY WEATHER AND TEMPS ACTUALLY WARMING ABOVE SEASONAL NORMALS BY SUNDAY. THE SREF AND NAM MODELS TRY TO ALLOW FOR SOME POP UP CONVECTION IN THE SMOKY MTNS SUNDAY AFTERNOON...WHILE GFS AND ECMWF REMAIN DRY. SAW NO REASON TO ADD SLIGHT CHANCE POPS JUST YET FOR SUNDAY AFTERNOON...AS GFS/NAM SOUNDINGS SHOW WARMING TEMPS ALOFT TO INHIBIT ANY CONVECTION. CLOSELY FOLLOWED THE SIMILAR NAM AND GFS MOS TEMPS THROUGH THE SHORT TERM. .LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY NIGHT)...THE MODELS CONTINUE TO SHOW A RATHER PLEASANT EXTENDED PERIOD WITH A FAIRLY EXTENDED PERIOD OF UPPER RIDGING AND AN ATMOSPHERE THAT MAY NOT HAVE QUITE ENOUGH MOISTURE TO GENERATE RAINFALL. THE GFS TRIES TO GENERATE A TINY LITTLE WEAKNESS IN THE RIDGE PATTERN IN THE VICINITY OF THE MOUNTAINS AND WITH SOME OROGRAPHICS IT SEEMS TO "OVERDO" THE CHANCE FOR A SHOWER OR THUNDERSTORM IN THE TERRAIN. STAYED WITH THE RATHER SMALL POPS THAT THE SUPERBLEND CREATE OVER THE FORECAST AREA AND TRIED TO TRIM BACK TO THE MORE ORGRAPHICALLY FAVORED PARTS OF THE VIEWING AREA NEXT WEEK. LOW LEVEL MOISTURE WILL BE GRADUALLY INCREASING THROUGH THE WEEK AS A LIGHT SOUTHERLY COMPONENT EDGES INTO THE SOUTHERN APPALACHIAN REGION AND THIS MAY LEAD TO AN EVER SO SLIGHT INCREASE IN POP FOR WIDELY SCATTERED...MAINLY TERRAIN INFLUENCED SHOWERS AND A POSSIBLE THUNDERSTORM TOWARD THE END OF THE WEEK. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 49 75 51 79 / 0 0 0 0 KNOXVILLE MCGHEE TYSON AIRPORT, TN 48 73 49 77 / 0 0 0 0 OAK RIDGE, TN 46 73 48 78 / 0 0 0 0 TRI CITIES AIRPORT, TN 43 70 44 76 / 10 0 0 0 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ TG
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
556 PM EDT FRI MAY 1 2015 .SYNOPSIS... AN UPPER LEVEL LOW PRESSURE SYSTEM WILL PROGRESS EASTWARD...OUT OF THE REGION TONIGHT. HIGH PRESSURE WILL BUILD INTO THE REGION THIS WEEKEND AND BE POSITIONED ACROSS OUR REGION INTO MUCH OF NEXT WEEK. OUR NEXT BEST CHANCE OF PRECIPITATION WILL COME DURING THE MIDDLE OF NEXT WEEK WHEN A BACKDOOR COLD FRONT APPROACHES OUR AREA. && .NEAR TERM /THROUGH SATURDAY/... AS OF 555 PM EDT FRIDAY... ADJUSTED TEMPERATURES DOWN IN RAIN COOLED LOCATIONS AND BLEND LAMP TEMPERATURES INTO THE OVERNIGHT. MODIFIED POPS AND WEATHER WITH LATEST WSR-88D TRENDS AND SHAPED POPS THIS EVENING INTO TONIGHT TOWARDS A BLEND OF THE HRRR AND THE RNK WRFARW. AS THE UPPER LOW PUSHES EAST...AREAL COVERAGE OF CONVECTION WILL DIMINISH AND EXIT THE REGION. PATCHES OF FOG WILL DEVELOP ESPECIALLY WHERE IT RAIN THIS AFTERNOON AND THIS EVENING AND CONTINUE INTO THE OVERNIGHT. HELD ON TO THE THE OVERNIGHT LOW TEMPERATURES FROM AROUND 40 DEGREES IN THE NORTHWEST MOUNTAINS TO THE UPPER 40S IN THE PIEDMONT. AS OF 300 PM EDT FRIDAY... AN AREA OF SHOWERS WITH A FEW THUNDERSTORMS CONTINUES TO EXPAND IN COVERAGE BETWEEN ROUGHLY HOT SPRINGS AND BLACKSBURG VA. THE PRECIPITATION WAS EXPANDING TOWARDS THE S-SW. HEADING INTO THIS EVENING...THE REGION OF PRECIPITATION WILL GRADUALLY MAKE PROGRESS EASTWARD...IN PACE WITH THE PROGRESSION OF THE RESPONSIBLE UPPER LEVEL LOW PRESSURE SYSTEM. COVERAGE WILL START TO DECREASE AT SUNSET...WITH THE LAST SHOWERS EXITING THE AREA OR DISSIPATING AROUND 11PM BETWEEN DANVILLE AND LYNCHBURG. CLOUD COVER WILL BE ON THE DECREASE THE REMAINDER OF THE NIGHT. PATCHY LIGHT RIVER VALLEY FOG WILL BE POSSIBLE...AND ALSO IN VALLEYS THAT RECEIVED PRECIPITATION THIS AFTERNOON OR EVENING. LOW TEMPERATURES WILL RANGE FROM AROUND 40 TO THE MID 40S ACROSS THE MOUNTAINS...WITH MID 40S TO UPPER 40S ACROSS THE PIEDMONT. ON SATURDAY...HIGH PRESSURE WILL START TO WORK ITS WAY INTO THE REGION FROM THE WEST. ONE LATE SHORTWAVE TROUGH ROUNDING THE BACKSIDE OF THE DEPARTING UPPER LOW IS EXPECTED TO MOVE SOUTH THROUGH CENTRAL VIRGINIA AND NORTH CAROLINA TOMORROW AFTERNOON. THIS FEATURE PASSING AT THE TIME OF PEAK HEATING MAY HELP TO GENERATE SOME ISOLATED SHOWERS...GENERALLY ALONG AND EAST OF A LEXINGTON VA TO REIDSVILLE NORTH CAROLINA LINE. THANKS TO BUILDING HEIGHTS AND LESS CLOUD COVER...ANTICIPATE A MILDER DAY ON SATURDAY AS COMPARED TO TODAY. HIGHS ACROSS THE MOUNTAINS WILL RANGE FROM THE MID 60S TO NEAR 70 DEGREES...WITH LOW TO MID 70S ACROSS THE PIEDMONT. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... AS OF 315 PM EDT FRIDAY... 500 MB HEIGHTS GRADUALLY RISE SATURDAY NIGHT AND SUNDAY AS THE PATTERN BECOMES MORE ZONAL. BUFKIT DATA FOR SUNDAY IN THE SOUTHWEST COUNTY WARNING AREA SHOWED A LARGE ENOUGH LOW LEVEL LAPSE RATE AND A LAYER OF MOISTURE THAT WOULD SUPPORT SHOWERS ISOLATED THUNDERSTORMS. HOWEVER...THERE WILL ONLY BE MINIMAL LIFT FROM ANY VORTICITY SO COVERAGE WILL BE CONFINED TO AREAS WITH THE BEST HEATING AND INSTABILITY. AIR MASS WARMS THROUGH THE PERIOD AND WILL BE CLOSE TO +10 TO +12 VALUES AT 850 MB BY THE END OF THE DAY ON MONDAY. THIS WILL PUT MAXIMUM TEMPERATURES JUST ABOVE NORMAL MONDAY. HIGH PRESSURE WILL BE OVER THE AREA SATURDAY NIGHT AND SUNDAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 125 PM EDT FRIDAY... LONG WAVE PATTERN ADVERTISED BY MODELS SHOWED TROFING IN THE WESTERN UNITED STATES AND A BROAD SOUTHEAST U.S. RIDGE. A SURFACE COLD FRONT THE THE NORTHERN STREAM WILL BE OVER THE GREAT LAKES ON MONDAY AND WILL PUSH SOUTH AS A BACKDOOR FRONT OVER THE MID ATLANTIC REGION TUESDAY AND WEDNESDAY. QUESTIONABLE HOW FAR SOUTH THIS BOUNDARY GETS HEADING INTO A LARGE RIDGE OVER THE SOUTHEAST. BEST PROBABILITY OF PRECIPITATION WILL BE IN THE VICINITY OF THIS BOUNDARY. OTHERWISE THE CHANCE WILL BE LIMITED TO AIRMASS TYPE THUNDERSTORMS...MAINLY IN THE MOUNTAINS EACH AFTERNOON AND EVENING. MAXIMUM/MINIMUM TEMPERATURES WILL REMAIN 5 TO 15 DEGREES ABOVE NORMAL TUESDAY THROUGH FRIDAY. && .AVIATION /22Z FRIDAY THROUGH WEDNESDAY/... AS OF 140 PM EDT FRIDAY... FORECAST CONFIDENCE IS MODERATE TO HIGH THROUGH SATURDAY. MIX OF MVFR AND LOW END VFR CIGS PREVAIL ACROSS THE REGION THIS AFTERNOON AS THE AREA AS AN AREA OF UPPER LEVEL LOW PRESSURE CROSS THE REGION. SHOWERS HAD STARTED TO DECREASE IN COVERAGE UNTIL RECENTLY. NOW THE FOCUS FOR NEW DEVELOPMENT WILL BE ALONG A KLWB- KBCB LINE...AND THEN POINTS EAST AS THE CONVECTION TRANSITIONS EASTWARD...FOLLOWING THE TRACK OF THE UPPER LOW. BRIEF...ISOLATED IFR CONDITIONS WILL BE POSSIBLE UNDER THE HEAVIER SHOWERS AND STORMS THAT DEVELOP. OVERNIGHT...CLOUDS WILL DECREASE IN COVERAGE AS DRIER AIR STARTS TO WORK ITS WAY INTO THE AREA...AND PRECIPITATION WILL DECREASE IN COVERAGE THROUGH THE EVENING HOURS. LINGERING BOUNDARY LAYER MOISTURE MAY DEVELOP INTO SOME PATCHY FOG IN THE RIVER AND MOUNTAIN VALLEYS AS WINDS TREND LIGHTER. BETWEEN KBLF-KLWB...A SHALLOW IFR CIG MAY DEVELOP AS LIGHT NORTHWEST FLOW GENERATES A SMALL UPSLOPE COMPONENT IN THIS AREA. ON SATURDAY...ANY SUB-VFR OVERNIGHT CONDITIONS WILL TRANSITION FAIRLY QUICKLY TO VFR AFTER SUNRISE. THE VISIBILITY SENSOR AT THE ASOS AT KBLF CONTINUES TO MALFUNCTION. WILL CONTINUE WITH AMD NOT SKED APPENDED TO ITS TAF. FORECAST CONFIDENCE IS HIGH SATURDAY AFTERNOON THROUGH MONDAY NIGHT. OTHER THAN SOME PATCHY LATE NIGHT/EARLY MORNING RIVER VALLEY FOG IN THE TYPICAL LOCATIONS...VFR CONDITIONS ARE EXPECTED THROUGH MONDAY NIGHT. FORECAST CONFIDENCE TUESDAY THROUGH WEDNESDAY IS MODERATE. LOOK FOR AN INCREASING AMOUNT OF SHOWERS AND LOWER BASED CLOUDS TUESDAY AND WEDNESDAY AS LOW LEVEL MOISTURE FLOW INCREASES ACROSS THE AREA...AND A BACKDOOR FRONT DRIFTS SOUTH TOWARD OR INTO OUR AREA. && .EQUIPMENT... AS OF 330 PM EDT FRIDAY... THE VISIBILITY SENSOR AT THE BLUEFIELD...KBLF...ASOS MAY ALTERNATE BETWEEN AVAILABLE AND UNAVAILABLE UNTIL SUCH TIME APPROPRIATE CORRECTIVE MEASURES CAN BE COMPLETED. THE NOAA WEATHER RADIO AT ROANOKE VIRGINIA...WXL60...WHICH BROADCASTS AT A FREQUENCY OF 162.475 MHZ...IS BACK ON THE AIR. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...DS NEAR TERM...DS/KK SHORT TERM...AMS LONG TERM...AMS AVIATION...DS EQUIPMENT...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
217 AM EDT FRI MAY 1 2015 .SYNOPSIS... AN UPPER LEVEL LOW WILL HEAD INTO NORTH CAROLINA TODAY. THIS UPPER LEVEL LOW SHOULD DEPART BY FRIDAY NIGHT...AND HIGH PRESSURE WILL ARRIVE TO BRING WARMER WEATHER FOR EARLY NEXT WEEK. THE CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS WILL RETURN AS THE WEEK PROGRESSES. && .NEAR TERM /THROUGH TODAY/... AS OF 200 AM EDT FRIDAY... FORECAST UPDATED TO CONCENTRATE HIGHER POPS FROM SRN WV...SOUTHEAST ACROSS THE NEW RIVER VALLEY INTO THE NW PIEDMONT OF NC...ALONG AXIS OF BEST SFC AND UPPER LEVEL FORCING AHEAD OF THE UPPER LOW. EXPECT THE SHOWERS TO PIVOT SW OVER THE MTNS AND TO THE NORTH OVER THE PIEDMONT AS EVIDENCED ON RADAR. AS THE LOW MOVES ACROSS NRN NC LATER THIS MORNING THE SHOWERS TO SHIFT FURTHER NORTHEAST TOWARD THE LYH/FVX AREA WITH SOME DRY SLOTTING DEVELOPING OVER THE NC MTNS/FOOTHILLS. AS SUCH KEPT SOME TREND OF OFFICIAL FORECAST THEN MADE SOME ADJUSTMENTS BASED ON LATEST HRRR/LOCAL WRF. OTHER ISSUE IS COLD AIR ALOFT. RADAR SHOWING BRIGHT BANDING OVER THE NRV INTO SRN WV...WITH EVIDENCE OF FZ LVL ABOUT 2000FT AGL. AS SUCH ADDED SOME SNOW MIXED IN ALONG THE HIGHER TERRAIN ABOVE 4KFT. PLACES LIKE MT ROGERS AND BEECH MTN COULD SEE A DUSTING TO AN MAYBE AN INCH. TEMP AT BEECH MTN AT 32F. PREVIOUS DISCUSSION FROM LATE THURSDAY EVENING... UPPER LOW CONTINUES TO DRIFT SOUTHEAST AND IN SO DOING...RAIN SHOWERS HAVE SPREAD BACK INTO THE REGION FROM THE NORTHWEST...GENERALLY PIVOTING ABOUT THE ROA/BCB REGION. ONE AREA OF RAIN PERSISTED FOR QUITE SOME TIME ACROSS NORTHERN PITTSYLVANIA/SOUTHERN CAMPBELL COUNTY WHERE DOPPLER RAINFALL ESTIMATES 1.5 TO 2.0 INCHES OF RAIN HAS FALLEN TODAY. CURRENT TREND ON POPS LOOKS GOOD. NOT SEEING ANY LIGHTNING ANY MORE AND WITH THE LOSS OF DAYTIME HEATING WOULD NOT EXPECT ANY FROM THIS POINT FORWARD. PREVIOUS GRIDS CAPTURED THE ENDING TIME OF THAT AS WELL. EARLIER ADJUSTMENT DOWNWARD OF TEMPERATURES HAS BEEN ON TRACK AND OTHER THAN A MINOR ADJUSTMENT DOWNWARD ACROSS THE PIEDMONT...TEMPERATURES APPEAR TO BE ON TRACK FOR THE REMAINDER OF THE NIGHT. SYNOPTIC SITUATION NOT PARTICULARLY SUPPORTIVE OF FOG...SO WILL NOT ADD ANY IN THE GRIDS AT THIS TIME. AS OF 730 PM EDT THURSDAY... SCATTERED RAIN SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO ROTATE AROUND THE UPPER LOW. MAIN AREA AT THIS MOMENT HAS SHIFTED OVER INTO THE NC PIEDMONT OUT OF OUR CWA...BUT A NEW AREA IS POISED TO MOVE INTO FAR SW VA. HRRR INDICATES ACTIVITY UP IN PA/NORTHERN VA/MD WILL SHIFT SOUTH OVERNIGHT ACROSS THE CWA FROM NORTH-SOUTH AS THE UPPER LOW MOVES ESE TOWARD THE COAST. THE PRECIPITATION RESULTED IN SOME SIGNIFICANT EVAPORATIVE COOLING IN THE WEST WITH TEMPERATURES DOWN IN THE 40S IN THE WESTERN COUNTIES. THUS...HAD TO LOWER TEMPERATURES IN THOSE AREAS A GOOD 10 DEGREES. HOWEVER...ADDITIONAL COOLING OVERNIGHT SHOULD BE LIMITED AS TEMPERATURES NEAR DEWPOINT. ONLY ADJUSTED OVERNIGHT MINS DOWN A COUPLE OF DEGREES. DID NOT ADJUST POPS MUCH AS HRRR SHOWS ACTIVITY CONTINUING MUCH OF THE NIGHT. WILL RE-EVALUATE POPS WITH LATER UPDATES. AS OF 405 PM EDT THURSDAY... AN UPPER LEVEL LOW CONTINUES TO HEAD CLOSER TO THE WESTERN PORTION OF THE CWA. CURRENTLY...SCATTERED SHOWERS AND THUNDERSTORMS ARE LINING UP OVER THE PIEDMONT. WEAK FLOW ALOFT IS CAUSING CONSIDERABLY SLOW STORM MOTIONS. DUE TO EARLIER SUNSHINE AND STEEPENING LAPSE RATES AS COOLER AIR ARRIVES ALOFT...SOME SMALL HAIL IS LIKELY IN THE STRONGER STORMS. WE HAVE ALREADY RECEIVED SEVERAL REPORTS OF PEA TO DIME SIZE HAIL THIS AFTERNOON...BUT NOTHING HAS REACHED SEVERE LIMITS. MEANWHILE...MORE SHOWERS AND THUNDERSTORMS ARE SPREADING OVER THE WESTERN MOUNTAINS. THIS ACTIVITY IS MUCH LESS ORGANIZED...BUT IT COULD PICK UP A LITTLE DURING THE NEXT SEVERAL HOURS. BY TONIGHT...THE UPPER LEVEL LOW WILL BE DIRECTLY OVERHEAD...WHICH WILL KEEP THE SHOWER ACTIVITY ONGOING THROUGHOUT THE NIGHT. HOWEVER...THUNDER CHANCES SHOULD DIMINISH AFTER MIDNIGHT. CLOUD COVER WILL BE WIDESPREAD...WHICH MEANS LOW TEMPERATURES COULD DROP NO FURTHER THAN THE 40S. ALTHOUGH MOISTURE WILL GRADUALLY SUBSIDE DURING FRIDAY...THE SHOWERS WILL LINGER INTO FRIDAY AFTERNOON. THE ACTIVITY SHOULD SPREAD EASTWARD INTO THE PIEDMONT...AND EVENTUALLY CLEAR THE CWA BY SUNSET. HIGHS ON FRIDAY MAY BE A LITTLE TRICKY IF THE CLOUD COVER TRIES TO SCATTER SOONER THAN ANTICIPATED BY THE MODELS. ONLY MID 50S TO LOWER 60S ARE EXPECTED FOR HIGHS...WHICH ARE A COUPLE DEGREES BELOW MOS GUIDANCE. && .SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/... AS OF 215 PM EDT THURSDAY... SATURDAY NIGHT...SOME LINGERING SHOWERS WILL STILL BE POSSIBLE DURING THE EARLY EVENING HOURS FROM EARLIER CONVECTION SATURDAY AFTERNOON. THE GREATEST CONCENTRATION WILL BE ACROSS THE MOUNTAINS...ALONG AND NORTH OF ROUTE 460. ON SATURDAY...ONE LAST SHORTWAVE TROUGH WILL SPIRAL AROUND THE WEST SIDE OF THE DEPARTING UPPER LOW. ANTICIPATED ISOLATED TO SCATTERED SHOWERS TO DEVELOP DURING THE PEAK HEATING OF THE AFTERNOON ACROSS THE EASTERN HALF OF THE REGION. INSTABILITY AT THIS TIME APPEARS TOO WEAK TO INCLUDE MENTION OF ISOLATED STORMS. SATURDAY NIGHT INTO SUNDAY...AN UPPER RIDGE WILL START TO BUILD JUST WEST OF THE REGION. THIS WILL BE THE START OF THE TREND OF MILDER CONDITIONS AND A MUCH LOWER PROBABILITY OF PRECIPITATION. AT BEST...ISOLATED SHOWERS MAY OCCUR SUNDAY AFTERNOON ACROSS THE NORTHERN MOUNTAINS OF NORTH CAROLINA. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 1230 PM EDT THURSDAY... UPPER LEVEL RIDGING WILL CONTINUE ACROSS THE REGION DURING THE MAJORITY OF THIS PORTION OF THE FORECAST. AN UPPER LOW MOVING EASTWARD THROUGH CANADA WILL WEAKEN THE RIDGE A BIT WEDNESDAY INTO THURSDAY...SHIFTING A BACKDOOR FRONT TOWARD OUR REGION. WHILE ALL OF THIS IS OCCURRING...AN ELONGATED TROUGH/UPPER LOW WILL BE DEVELOPING ACROSS THE CENTRAL PART OF THE COUNTRY. WE ARE ANTICIPATING PROGRESSIVELY MILDER TEMPERATURES EACH DAY WITHIN THIS REGIME. FOR PRECIPITATION...THE CENTER OF THE SURFACE HIGH WILL JUST BE SHIFTING EAST OF THE AREA ON MONDAY. THIS WILL LIMIT THE DEGREE OF RETURN MOISTURE INTO THE AREA TO THE NORTHERN MOUNTAINS OF NORTH CAROLINA. IT IS HERE WHERE ISOLATED SHOWERS WILL BE FORECAST FOR THE AFTERNOON. FROM TUESDAY INTO THURSDAY...COVERAGE OF SHOWERS AND STORMS WILL BE INCREASING...ESPECIALLY IN THE WEST...WITH THE APPROACH...AND POTENTIAL ARRIVAL...OF THE BACKDOOR FRONT. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... AS OF 200 AM EDT FRIDAY... SHOWERS WILL BE MORE NUMEROUS OVERNIGHT INTO FRIDAY AS UPPER LOW MOVES FROM THE MTNS OF SW VA INTO THE NC PIEDMONT. AXIS OF MODERATE TO HEAVY SHOWER SHOULD AFFECT BLF-BCB-DAN THIS MORNING THEN LIFT NE TO ROA/LYH AND POSSIBLY LWB THROUGH THE MORNING. NOT GOING TO GET CUTE WITH THE INS AND OUTS OF LIGHT TO MODERATE RAIN AND KEEP IT MOSTLY LIGHT. FREEZING LEVEL IS ABOUT 4-5KFT MSL...SO MAY HAVE TO DEAL WITH ICING. THE TERMINALS SHOULD GO TO SUB VFR IF NOT ALREADY THERE AS LOW LVLS MOISTEN UP. KEEPING SOME FOG IN AS WELL ACROSS THE MTNS LATER THIS MORNING. MODELS SHOWING INCREASE IN CIGS TOWARD MID TO LATE MORNING AND WILL TREND THAT WAY...WHICH WE ALREADY HAD IN THE PREVIOUS TAFS. THE RAIN SHOWER SWING EAST THROUGH THE DAY AND SHOULD BE GONE FRIDAY AFTERNOON...WITH ALL SITES TURNING TO VFR...THOUGH NW FLOW IS GOING TO PERSIST INTO THE MTNS...SO BLF APPEARS THEY MAY KEEP MVFR CIGS THRU THE END OF THIS TAF PERIOD. CONFIDENCE IS FAIRLY HIGH FOR WINDS/CIGS AND MEDIUM ON RAINFALL INTENSITY AND VSBYS. A SIGNIFICANT WEATHER PATTERN CHANCE WILL TAKE PLACE THIS WEEKEND...AS HIGH PRESSURE BUILDS OVERHEAD. OTHER THAN POSSIBLE EARLY MORNING MVFR FOG IN THE USUAL RIVER VALLEY LOCATIONS...VFR CONDITIONS SHOULD PERSIST THROUGH THIS WEEKEND INTO EARLY NEXT WEEK. A WARMER AND MOISTER AIR MASS COULD ALLOW FOR A FEW SHOWERS TO POP UP DURING MONDAY AFTERNOON. A GREATER CHANCE OF SHOWERS...WITH A FEW ISOLATED THUNDERSTORMS IN THE WESTERN MOUNTAINS...ARE POSSIBLE FOR TUESDAY. && .EQUIPMENT... AS OF 150 AM EDT FRIDAY... PART FOR THE UPPER AIR ARRIVED LATE FRIDAY EVENING AND TECHNICIANS WILL WORK ON GETTING THIS FIXED TO HAVE A 12Z UPPER AIR RUN TODAY. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...PW NEAR TERM...PW/WP SHORT TERM...DS/RAB LONG TERM...DS AVIATION...KK/PW/WP EQUIPMENT...WP
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AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
937 PM CDT SAT MAY 2 2015 .UPDATE...EXPECT SHOWERS AND ISOLD THUNDER OVER ERN IA TO MOVE OFF TO THE SOUTHEAST NEXT SEVERAL HOURS AS MID-LEVEL SHORT WAVE PASSES INTO CENTRAL IL. THIS WL ALLOW LOW LEVEL JET TO REFOCUS INTO SRN WI REGION DURING THE LATE NIGHT. COLUMN PWAT VALUES EXPECTED TO DOUBLE TO AROUND 1 INCH BY 12Z. SFC DEWPTS WL REMAIN STEADY OR RISE THROUGH THE 40S. DUE TO EXPECTED LOW LEVEL MOISTURE CONVERGENCE AND WEAK 700H SHORT WAVE...WL CONTINUE SMALL CHANCE FOR SHOWERS AND ISOLD THUNDER LATE TONIGHT INTO SUN MRNG ACROSS MOST OF THE AREA. SLY BREEZES AND RETURNING CLOUDS WL KEEP TEMPS MILD...BUT DID NEED TO LOWER SHEBOYGAN A FEW DEGREES. && .AVIATION/06Z TAFS/...VFR CONDITIONS TO CONTINUE THROUGH SUN. STRENGTHENING LOW LEVEL JET OVERNIGHT WILL RESULT IN WINDS APPROACHING LOW LEVEL WIND SHEAR CRITERIA AT KMSN...AS DEPICTED BY RAP BUFKIT SOUNDINGS. APPEARS WIND SHEAR TO REMAIN JUST BELOW THRESHOLD SO WL HOLD OFF ON INTRODUCING INTO KMSN TAF AT THIS TIME. WL INCLUDE THUNDER IN MOST TAFS LATER SUN EVE. && .MARINE...SHALLOW INVERSION OVER NEAR SHORE WATERS OVERNIGHT WILL OCCASIONALLY RESULT IN WIND GUSTS OF 15 TO 20 KNOTS AWAY FROM THE SHORE. OTHERWISE...STRONGER LOW LEVEL MIXING ON SUNDAY WILL RESULT IN WIND GUSTS TO 25 KNOTS DEVELOPING DURING THE MORNING. SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT. THUNDERSTORMS WITH THE POTENTIAL FOR STRONG WIND GUSTS WILL AFFECT THE NEAR SHORE WATERS AFTER 02Z/MON. && .PREV DISCUSSION... /ISSUED 325 PM CDT SAT MAY 2 2015/ SHORT TERM... TONIGHT AND SUNDAY...FORECAST CONFIDENCE...HIGH A WEAK SHORTWAVE WILL MOVE THROUGH TONIGHT INTO SUNDAY MORNING...BRINGING A CHANCE FOR SHOWERS. BEST CHANCE WILL BE LATER TONIGHT THROUGH THROUGH THE MIDDLE OF SUNDAY MORNING ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. MAY HEAR A RUMBLE OR TWO OF THUNDER AS INSTABILITY SLOWLY INCREASES. SHOULD BE MAINLY DRY THEN LATE MORNING INTO THE AFTERNOON...WITH DECREASING CLOUDS AS WELL. WITH CLOUDS EXPECTED AGAIN TONIGHT AND MILD TEMPS ALOFT...LOWS WILL LIKELY BE IN THE 50S. TEMPS WILL VERY PLEASANT AGAIN SUNDAY...WITH HIGHS IN THE UPPER 70S TO LOW 80S...THOUGH IT WILL BE BREEZIER THAN TODAY. ALONG SHORE WINDS WILL LIKELY BRING SOME COOLER AIR INTO LAKESHORE AREAS MAINLY NORTH OF MILWAUKEE...PARTICULARY TOWARD THE SHEBOYGAN AREA. SUNDAY NIGHT AND MONDAY...FORECAST CONFIDENCE IS HIGH. A MID AND UPPER LEVEL SHORTWAVE MOVES ACROSS SOUTH CENTRAL CANADA AS THE 250 MB UPPER JET MAX INCREASES TO 125 KNOTS AS IT MOVES ACROSS THE LAKE SUPERIOR REGION. THE STRONGEST UPPER DIVERGENCE AFFECTS NORTHERN AND WESTERN AREAS OF THE FORECAST AREA EARLY SUNDAY NIGHT...AND WEAKENS AS IT SAGS SOUTHEAST. THEN AS THE SHORTWAVE MOVES INTO SOUTHEAST CANADA THE RIGHT ENTRANCE REGION OF THE JET BEGINS TO INCREASE THE UPPER DIVERGENCE AGAIN LATER MONDAY AFTERNOON. AN 850/700 MB WARM AXIS PUSHES INTO SOUTHERN WISCONSIN...BUT COOLS SOMEWHAT LATER SUNDAY NIGHT AND MONDAY...ESPECIALLY AT 700 MB. THE STRONGEST 850/700 MB WINDS ARE ALREADY ACROSS THE UPPER GREAT LAKES BY MIDNIGHT...WITH WIND SPEEDS WEAKENING LATER SUNDAY NIGHT AND MONDAY. THE 850/700 MB RH INCREASES SUNDAY NIGHT...BUT DOES NOT SATURATE UNTIL LATER MONDAY...ESPECIALLY IN THE FAR SOUTH. MODELS IN DECENT AGREEMENT WITH SLIDING COLD FRONT INTO SOUTHERN WISCONSIN FROM THE NORTHWEST SUNDAY NIGHT THEN EXITING THE FAR SOUTHEAST MONDAY AFTERNOON. EXPECT A LINE OF THUNDERSTORMS TO PUSH INTO SOUTHERN WISCONSIN SUNDAY NIGHT...THEN WEAKEN AS THE LOW/MID LEVEL CONVERGENCE WEAKENS WITH THE BEST MID/UPPER LEVEL FORCING STAYING NORTH BEFORE MOVING OFF. THE NAM HAS THE HIGHEST ZERO-1 KM CAPE...ALMOST 2000 JOULES/KG NORTHWEST TOWARDS THE DELLS AT 7PM CDT SUNDAY...DUE TO THE TYPICAL NAM BIAS OF HIGHER LOW LEVEL MOISTURE. THE CAPE DROPS TO AROUND 500 JOULES/KG LATE SUNDAY NIGHT. SOME POTENTIAL WITH INSTABILITY RISING AGAIN MONDAY NEAR THE ILLINOIS BORDER BEFORE THE COLD FRONT EXITS AND LAKE COOLING INCREASES. SPC DAY 2 OUTLOOK HAS OUR FAR NORTHWEST TOWARDS THE DELLS IN A SLIGHT RISK OF SEVERE NOW WITH THE REST OF SOUTH CENTRAL AND NORTHWEST PORTIONS OF SOUTHEAST WISCONSIN CONTINUING IN THE MARGINAL CATEGORY. MONDAY NIGHT AND TUESDAY...FORECAST CONFIDENCE IS HIGH. A ZONAL WEST TO EAST FLOW EXTENDS ACROSS THE U.S./CANADIAN BORDER WITH A WEAKENING UPPER JET MAX ACROSS THE NORTHERN GREAT LAKES. STILL SOME WEAK UPPER LEVEL DIVERGENCE DUE TO THE PROXIMITY OF THE JETS RIGHT ENTRANCE REGION. THE 850/700 MB SOUTHWEST FLOW INCREASES AGAIN AS IT LIFTS TO THE NORTH. THIS INCREASES THE 850/800 MB MOISTURE CONVERGENCE AND 700 MB UPWARD MOTION AS IT PUSHES TO THE NORTH. THE 700 MB RH BECOMES SATURATED MONDAY NIGHT WITH THE SATURATION LIFTING INTO CENTRAL WISCONSIN TUESDAY. THE 950/850 MB PATTERN IS SIMILAR...JUST NOT QUITE SATURATED. MEANWHILE THE SURFACE FRONT STAYS JUST SOUTH OF THE ILLINOIS BORDER. THE NAM SOUNDINGS INDICATE A LOW STRATUS OVER MUCH OF SOUTHERN WISCONSIN...WITH SOME ELEVATED CAPE. HOWEVER THE MODEL BRINGS THE SOUNDING TO MOIST ADIABATIC DUE TO THE GENERATED PRECIPITATION. LONG TERM... TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS HIGH. AN UPPER RIDGE BUILDS INTO WISCONSIN FROM THE OHIO RIVER VALLEY AS A SHORTWAVE TROUGH PUSHES INTO THE CENTRAL PLAINS. LOW PRESSURE EXPANDS ACROSS THE PLAINS WITH AN INCREASING SOUTH FLOW ACROSS WISCONSIN. THIS LIFTS THE SURFACE BOUNDARY NORTH INTO SOUTHERN WISCONSIN...AND APPROACHES CENTRAL WISCONSIN WEDNESDAY AFTERNOON. AS A RESULT THE SHOWERS AND SCATTERED THUNDERSTORM POTENTIAL WOULD LIFT NORTH ACROSS MUCH OF SOUTHERN WISCONSIN... WITH THE FAR SOUTH POTENTIALLY PRECIPITATION FREE WEDNESDAY AFTERNOON. WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE IS MEDIUM. THE SHORTWAVE TROUGH LIFTS NORTHEAST AND WEAKENS. THE 12Z GFS IS FASTER WITH THE TROUGH THAN THE 00Z ECMWF. THE MODELS ARE MAINLY PRECIP FREE OVER MOST OF THE AREA...WITH SOUTHERN WISCONSIN IN A WARM AND INCREASINGLY MOIST AIRMASS. FRIDAY AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM. THE WEAKENING SHORTWAVE CONTINUES TO LIFT NORTHEAST TOWARD WISCONSIN AND THE LAKE SUPERIOR AREA. AS LOW PRESSURE MOVES NORTHEAST FROM MINNESOTA TOWARDS THE LAKE SUPERIOR AREA...A TRAILING COLD FRONT ENTERS SOUTH CENTRAL WISCONSIN FRIDAY AFTERNOON AND EVENING...EXITING THE SOUTHEAST SATURDAY. THE 12Z GFS STALLS THE FRONT ACROSS SOUTHERN WISCONSIN. THIS WILL KEEP THE SHOWER AND THUNDERSTORM CHANCES THROUGH THE PERIOD ON THE GFS...BUT WOULD DRY THINGS OUT BEHIND THE FRONT FRIDAY ON THE 00Z ECMWF. AVIATION/00Z TAFS/... VFR CONDITIONS ARE EXPECTED THROUGH THE DAY SUNDAY. A WEAK WAVE WILL MOVE THROUGH TONIGHT INTO SUNDAY...POSSIBLY KICKING OFF A FEW SHOWERS AND MAYBE A RUMBLE OR TWO OF THUNDER. BETTER CHANCE FOR WIDESPREAD SHOWERS/STORMS WILL COME SUNDAY EVENING AND OVERNIGHT AS A COLD FRONT MOVES THROUGH. WILL PROBABLY SEE LOWER VSBYS WITH ANY MODERATE TO HEAVY RAIN. MARINE... A SMALL CRAFT ADVISORY IS BEING ISSUED THIS AFTERNOON FOR SUNDAY...MID MORNING UNTIL EVENING. SOUTH TO SOUTHWEST WINDS WILL GUST TO 25 KNOTS. WAVES SHOULD STAY GENERALLY LESS THAN 4 FEET GIVEN THE WIND DIRECTION. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...SMALL CRAFT ADVISORY FROM 10 AM TO 7 PM CDT SUNDAY FOR LMZ643>646. && $$ UPDATE...MBK
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
930 AM CDT FRI MAY 1 2015 .UPDATE... SHOWERS OVER MINNESOTA AND IOWA ASSOCIATED WITH A SHORTWAVE WILL MOVE EASTWARD INTO WISCONSIN TODAY. MODELS CONTINUE TO SUGGEST THAT THE SHOWERS WILL MAINLY FALL APART...THOUGH A FEW MAY SURVIVE AS THE SHORTWAVE MOVES THROUGH. WILL CONSIDER ADDING LOW POPS OR SPRINKLES TO THE FORECAST FOR LATE AFTERNOON AND EVENING...DEPENDING ON RADAR TRENDS LATER ON. TEMPERATURES ARE ON TRACK FOR FORECAST HIGHS...SO NO SIGNIFICANT FORECAST UPDATES ARE EXPECTED FOR THE REMAINDER OF THE DAY. && .AVIATION/18Z TAFS/... VFR CONDITIONS WILL PERSIST THROUGH SATURDAY. COULD SEE A FEW SHOWERS OR SPRINKLES ARRIVE LATE AFTERNOON INTO THIS EVENING...BUT EXPECTING UPSTREAM AREA OF RAIN TO MAINLY FALL APART AS IT HEADS EASTWARD TODAY. MODELS SHOWING A STRAY SHOWER OR TWO POSSIBLE SATURDAY...BUT MOST PLACES SHOULD REMAIN DRY THROUGH TOMORROW. WINDS WILL TURN EAST TO SOUTHEAST NEAR LAKE MICHIGAN LATE THIS MORNING INTO THE AFTERNOON. WILL HAVE TO WATCH FOR A POSSIBLE WIND SHIFT SATURDAY AFTERNOON NEAR THE LAKE...DEPENDING ON HOW STRONG PREVAILING SOUTHWEST WINDS ARE. BEST CHANCE FOR SOUTH TO SOUTHEAST WINDS LOOKS TO BE NORTH OF MILWAUKEE. && .PREV DISCUSSION... /ISSUED 328 AM CDT FRI MAY 1 2015/ TODAY...FORECAST CONFIDENCE IS HIGH. DRY AND SUNNY TO START THE DAY WITH HIGH PRESSURE OVER REGION. SLOWLY INCREASING HIGH TO MID LEVEL CLOUDS FROM THE WEST WITH APPROACHING SHORT WAVE TROUGH. BRIEF PERIOD OF STRONG UPPER LIFT WITH CVA AHEAD OF SHORT MOVES INTO THE WEST BETWEEN 21Z AND 00Z. NAM AND RAP SOUNDINGS/CROSS SECTIONS DEPICTING A DEEPER MOIST LAYER ABOVE 10K FT THAN GFS COINCIDENT WITH THIS LIFT...BUT ALL FORECAST SOUNDINGS ARE VERY DRY BELOW 10K FEET...REFLECTING THE DRY LOWER LEVEL AIR IN PLACE WITH THE HIGH. CURRENT SHOWERS IN THE EASTERN DAKOTAS WITHIN NARROW RIBBON OF MOISTURE RETURN/POOLING LIMITED TO RIGHT ALONG THE SURFACE TROUGH. BUT SURFACE TROUGH WASHES OUT AS IT MOVES TOWARD WESTERN WISCONSIN...WITH AN ATTENDANT SHARP REDUCTION IN FRONTOGENETIC FORCING, ADDED ISOLATED SPRINKLES IN THE FAR WEST MORE FOR COLLABORATION... BUT WILL BE HARD TO GET ANY PRECIPITATION TO REACH THE SURFACE THROUGH THE DEEP DRY LAYER AND WEAKENING FORCING. SLOWLY RISING 925 MB TEMPERATURES WILL YIELD HIGHS AROUND 70 IN SOUTH CENTRAL WISCONSIN...WITH MID TO UPPER 60S OVER SOUTHEAST WISCONSIN AWAY FROM THE LAKE...WITH WEAK GRADIENT ALLOWING A LIGHT LAKE BREEZE THAT KEEPS AREAS WITHIN 5-10 MILES OF THE LAKE IN THE 50 TO 60 DEGREE RANGE. TONIGHT...FORECAST CONFIDENCE IS HIGH. DECENT UPPER LEVEL LIFT CROSSES REST OF THE REGION WITH SHORT WAVE THIS EVENING...BUT LAYERS BELOW 5K FEET NEVER SATURATE...AND LOWER LEVEL FORCING WEAKENS RAPIDLY AHEAD OF TROUGH. WILL KEEP TONIGHT DRY WITH ONLY CLOUDS MARKING THE PASSAGE OF THE TROUGH. THE MOSTLY CLOUDY SKIES AND WEAK WARM ADVECTION ON SOUTHERLY WINDS WILL KEEP LOWS IN THE MID-UPPER 40S...WITH A FEW 50 DEGREE LOWS IN THE WEST. SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. MODELS ARE IN GOOD AGREEMENT WITH WARM AIR ADVECTION LINGERING ACROSS THE AREA DURING THIS PERIOD. INCREASING SOUTH TO SOUTHWEST WINDS ARE EXPECTED...BRINGING WARM TEMPERATURES TO MOST OF THE AREA. ONSHORE WINDS NORTH OF PORT WASHINGTON MAY KEEP COOLER TEMPERATURES THERE. HIGHS SHOULD REACH INTO THE 70S ON SATURDAY...WITH HIGHS IN THE MID 70S TO AROUND 80 ON SUNDAY. MOISTURE IS MEAGER SATURDAY INTO SATURDAY NIGHT ACROSS THE AREA...SO NOT EXPECTING MUCH IN THE WAY OF PRECIPITATION...DESPITE WARM AIR ADVECTION AND WEAK 500 MB VORTICITY MAXIMUM PASSING SOUTH OF THE AREA. SUNDAY MAY END UP DRY AS WELL...WITH BEST UPWARD VERTICAL MOTION AND MOISTURE COMBINATION NOT ARRIVING UNTIL SUNDAY NIGHT...AS THE COLD FRONT APPROACHES FROM THE NORTHWEST. KEPT SOME POPS FOR SUNDAY FOR NOW...BUT MAY NEED TO BE LOWERED OR REMOVED IN LATER FORECASTS. KEPT LIKELY POPS FOR SUNDAY NIGHT...WHICH MAY NEED TO BE RAISED IN LATER FORECASTS. AREA FORECAST SOUNDINGS SUGGEST 500 TO 1000 J/KG MEAN LAYER OR ELEVATED CAPE...THOUGH DEEP LAYER SHEAR IS MODEST AT BEST. SPC KEPT MARGINAL SEVERE RISK NORTHWEST OF THE AREA SUNDAY...CLOSER TO THE FRONT. SHOULD BRING SOME NEEDED RAINFALL TO THE AREA. LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS MEDIUM. ECMWF/GFS IN DECENT AGREEMENT WITH TAKING COLD FRONT INTO NORTHERN ILLINOIS MONDAY...STALLING OUT MONDAY NIGHT INTO TUESDAY...BEFORE SHIFTING BACK NORTH AS A WARM FRONT TUESDAY NIGHT INTO WEDNESDAY. KEPT POPS GOING FOR THIS PERIOD...THOUGH THERE MAY BE MORE BREAKS DURING THIS TIME. GFS WAS SHOWING WEAK CAPE...SO HAVE SOME SLIGHT CHANCES FOR THUNDER GOING IN FORECAST. TEMPERATURES RETURN CLOSER TO SEASONAL NORMALS...WITH ONSHORE WINDS NEAR THE LAKE. MODELS DIFFER MORE INTO THURSDAY...THOUGH BOTH SHOWING SOME WARM AIR ADVECTION DEVELOPING INTO THE AREA. USED CONSENSUS POPS AND TEMPERATURES FOR WEDNESDAY NIGHT INTO THURSDAY FOR NOW. AVIATION/12Z TAFS/... VFR CONDITIONS THROUGH THE FORECAST WITH HIGH PRESSURE DOMINATING THE FORECAST. WILL SEE INCREASING VFR CLOUDS...MAINLY ABOVE 10K FT...MOVE FROM WEST TO EAST THIS AFTERNOON INTO THIS EVENING WITH A WEAK UPPER LEVEL WAVE...BUT CLOUD DECK WILL NOT LOWER MORE THAN 5K FEET WITH NO PRECIPITATION EXPECTED. FIRE WEATHER... MAX TEMPERATURES WEST OF THE KETTLE MORAINE WILL RANGE BETWEEN 65 AND 70 DEGREES...WITH MINIMUM RELATIVE HUMIDITY VALUES OF 25 TO 30 PERCENT WEST OF A RIPON...WATERTOWN TO DELAVAN LINE. SW WINDS WILL BE BETWEEN 8 AND 10 MPH...WITH GUSTS BELOW 15 MPH THIS AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ UPDATE...DDV TODAY/TONIGHT AND AVIATION/FIRE WEATHER...REM SATURDAY THROUGH THURSDAY...WOOD
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
328 AM CDT FRI MAY 1 2015 .TODAY...FORECAST CONFIDENCE IS HIGH. DRY AND SUNNY TO START THE DAY WITH HIGH PRESSURE OVER REGION. SLOWLY INCREASING HIGH TO MID LEVEL CLOUDS FROM THE WEST WITH APPROACHING SHORT WAVE TROUGH. BRIEF PERIOD OF STRONG UPPER LIFT WITH CVA AHEAD OF SHORT MOVES INTO THE WEST BETWEEN 21Z AND 00Z. NAM AND RAP SOUNDINGS/CROSS SECTIONS DEPICTING A DEEPER MOIST LAYER ABOVE 10K FT THAN GFS COINCIDENT WITH THIS LIFT...BUT ALL FORECAST SOUNDINGS ARE VERY DRY BELOW 10K FEET...REFLECTING THE DRY LOWER LEVEL AIR IN PLACE WITH THE HIGH. CURRENT SHOWERS IN THE EASTERN DAKOTAS WITHIN NARROW RIBBON OF MOISTURE RETURN/POOLING LIMITED TO RIGHT ALONG THE SURFACE TROUGH. BUT SURFACE TROUGH WASHES OUT AS IT MOVES TOWARD WESTERN WISCONSIN...WITH AN ATTENDANT SHARP REDUCTION IN FRONTOGENETIC FORCING, ADDED ISOLATED SPRINKLES IN THE FAR WEST MORE FOR COLLABORATION... BUT WILL BE HARD TO GET ANY PRECIPITATION TO REACH THE SURFACE THROUGH THE DEEP DRY LAYER AND WEAKENING FORCING. SLOWLY RISING 925 MB TEMPERATURES WILL YIELD HIGHS AROUND 70 IN SOUTH CENTRAL WISCONSIN...WITH MID TO UPPER 60S OVER SOUTHEAST WISCONSIN AWAY FROM THE LAKE...WITH WEAK GRADIENT ALLOWING A LIGHT LAKE BREEZE THAT KEEPS AREAS WITHIN 5-10 MILES OF THE LAKE IN THE 50 TO 60 DEGREE RANGE. .TONIGHT...FORECAST CONFIDENCE IS HIGH. DECENT UPPER LEVEL LIFT CROSSES REST OF THE REGION WITH SHORT WAVE THIS EVENING...BUT LAYERS BELOW 5K FEET NEVER SATURATE...AND LOWER LEVEL FORCING WEAKENS RAPIDLY AHEAD OF TROUGH. WILL KEEP TONIGHT DRY WITH ONLY CLOUDS MARKING THE PASSAGE OF THE TROUGH. THE MOSTLY CLOUDY SKIES AND WEAK WARM ADVECTION ON SOUTHERLY WINDS WILL KEEP LOWS IN THE MID-UPPER 40S...WITH A FEW 50 DEGREE LOWS IN THE WEST. .SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM. MODELS ARE IN GOOD AGREEMENT WITH WARM AIR ADVECTION LINGERING ACROSS THE AREA DURING THIS PERIOD. INCREASING SOUTH TO SOUTHWEST WINDS ARE EXPECTED...BRINGING WARM TEMPERATURES TO MOST OF THE AREA. ONSHORE WINDS NORTH OF PORT WASHINGTON MAY KEEP COOLER TEMPERATURES THERE. HIGHS SHOULD REACH INTO THE 70S ON SATURDAY...WITH HIGHS IN THE MID 70S TO AROUND 80 ON SUNDAY. MOISTURE IS MEAGER SATURDAY INTO SATURDAY NIGHT ACROSS THE AREA...SO NOT EXPECTING MUCH IN THE WAY OF PRECIPITATION...DESPITE WARM AIR ADVECTION AND WEAK 500 MB VORTICITY MAXIMUM PASSING SOUTH OF THE AREA. SUNDAY MAY END UP DRY AS WELL...WITH BEST UPWARD VERTICAL MOTION AND MOISTURE COMBINATION NOT ARRIVING UNTIL SUNDAY NIGHT...AS THE COLD FRONT APPROACHES FROM THE NORTHWEST. KEPT SOME POPS FOR SUNDAY FOR NOW...BUT MAY NEED TO BE LOWERED OR REMOVED IN LATER FORECASTS. KEPT LIKELY POPS FOR SUNDAY NIGHT...WHICH MAY NEED TO BE RAISED IN LATER FORECASTS. AREA FORECAST SOUNDINGS SUGGEST 500 TO 1000 J/KG MEAN LAYER OR ELEVATED CAPE...THOUGH DEEP LAYER SHEAR IS MODEST AT BEST. SPC KEPT MARGINAL SEVERE RISK NORTHWEST OF THE AREA SUNDAY...CLOSER TO THE FRONT. SHOULD BRING SOME NEEDED RAINFALL TO THE AREA. .LONG TERM...MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE IS MEDIUM. ECMWF/GFS IN DECENT AGREEMENT WITH TAKING COLD FRONT INTO NORTHERN ILLINOIS MONDAY...STALLING OUT MONDAY NIGHT INTO TUESDAY...BEFORE SHIFTING BACK NORTH AS A WARM FRONT TUESDAY NIGHT INTO WEDNESDAY. KEPT POPS GOING FOR THIS PERIOD...THOUGH THERE MAY BE MORE BREAKS DURING THIS TIME. GFS WAS SHOWING WEAK CAPE...SO HAVE SOME SLIGHT CHANCES FOR THUNDER GOING IN FORECAST. TEMPERATURES RETURN CLOSER TO SEASONAL NORMALS...WITH ONSHORE WINDS NEAR THE LAKE. MODELS DIFFER MORE INTO THURSDAY...THOUGH BOTH SHOWING SOME WARM AIR ADVECTION DEVELOPING INTO THE AREA. USED CONSENSUS POPS AND TEMPERATURES FOR WEDNESDAY NIGHT INTO THURSDAY FOR NOW. && .AVIATION/12Z TAFS/... VFR CONDITIONS THROUGH THE FORECAST WITH HIGH PRESSURE DOMINATING THE FORECAST. WILL SEE INCREASING VFR CLOUDS...MAINLY ABOVE 10K FT...MOVE FROM WEST TO EAST THIS AFTERNOON INTO THIS EVENING WITH A WEAK UPPER LEVEL WAVE...BUT CLOUD DECK WILL NOT LOWER MORE THAN 5K FEET WITH NO PRECIPITATION EXPECTED. && .FIRE WEATHER... MAX TEMPERATURES WEST OF THE KETTLE MORAINE WILL RANGE BETWEEN 65 AND 70 DEGREES...WITH MINIMUM RELATIVE HUMIDITY VALUES OF 25 TO 30 PERCENT WEST OF A RIPON...WATERTOWN TO DELAVAN LINE. SW WINDS WILL BE BETWEEN 8 AND 10 MPH...WITH GUSTS BELOW 15 MPH THIS AFTERNOON. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...NONE. LM...NONE. && $$ TODAY/TONIGHT AND AVIATION/MARINE...REM SATURDAY THROUGH THURSDAY...WOOD
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
356 PM MDT FRI MAY 1 2015 .SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT) ISSUED AT 354 PM MDT FRI MAY 1 2015 SHOWERS AND THUNDERSTORMS ARE ON THE UPTICK ALONG THE INTERSTATE 80 CORRIDOR IN SOUTHEAST WY THIS AFTERNOON. AS EXPECTED...THE GREATEST COVERAGE HAS BEEN IN ALBANY IN LARAMIE COUNTIES WITH ENHANCED LOWER LEVEL CONVERGENCE ALONG THE LARAMIE RANGE. THE KCYS RADAR LOOP ALSO SHOWS NUMEROUS BOUNDARIES IN THE VICINITY OF CYS...LIKELY PLAYING A ROLE IN CONVECTIVE EVOLUTION. CLOUDS CLEARED LATE THIS AM...HELPING PUSH SFC TEMPS INTO THE 55-65 DEGREE RANGE AMID DECENT LLVL MOISTURE WITH DEWPOINTS IN THE MID 40S F. THIS BENEATH STEEP MID LEVEL LAPSE RATES ON THE ORDER OF 8-9 DEG C/KM IS CONTRIBUTING TO SBCAPES ON THE ORDER OF 1500 J/KG PER THE 21Z SPC MESOANALYSIS. GFS AND NAM BUFKIT SOUNDINGS BOTH SHOW H5 FLOW AROUND 30 KTS...WHICH COMBINED WITH GOOD VEERING IN THE SFC-500 MILLIBAR LAYER IS CONTRIBUTING TO EFFECTIVE BULK SHEAR VALUES FAVORABLE FOR ROTATING UPDRAFTS (35-45 KTS). COULD SEE A HAIL THREAT EVOLVE WITH SOME CELLS...BUT DO NOT EXPECT TO SEE MORE THAN ONE OR TWO SEVERE STORMS. OPTED TO MAINTAIN SMALL HAIL AND GUSTY WIND WORDING IN THE OFFICIAL FORECAST. LATEST HRRR HAS CHANGED VERY LITTLE FROM THIS MORNING...AND APPEARS TO BE ACCURATELY SHOWING CONVECTIVE ELEMENTS BETWEEN LARAMIE AND CHEYENNE. FOR THAT REASON... WILL MAINTAIN LIKELY POPS FOR THOSE AREAS. CONVECTIVE COVERAGE WILL DWINDLE OVERNIGHT WITH THE LOSS OF DAYTIME HEATING/INSTABILITY. QUASI-ZONAL FLOW ALOFT PERSISTS INTO SATURDAY. A SERIES OF MID LEVEL DISTURBANCES WILL TRAVERSE THE FLOW OVER THE CENTRAL ROCKIES...ONCE AGAIN PROMOTING AFTERNOON CONVECTION CHANCES. THE DAY 2 SPC OUTLOOK HAS SHIFTED THE MARGINAL RISK EAST OF OUR CWA...WHICH MAKES SENSE AS THE LATEST IN-HOUSE WRF PLACES THE BEST INSTABILITY AXIS EAST OF AN ALLIANCE TO SIDNEY LINE BETWEEN 18-20Z SAT. POTENTIAL FOR WIDESPREAD THUNDERSTORMS WILL DEPEND ON THE TIMING OF THE DRYLINE. GFS AND NAM BOTH PUSH THIS FEATURE EAST OF THE CWA BY EARLY TO MID AFTERNOON... BUT MODELS TEND TO MIX DRYLINES A BIT QUICKLY. LATER SHIFTS MAY NEED TO ADJUST POPS ACCORDINGLY IF IT APPEARS THE LOW-LEVEL CONVERGENCE ZONE WILL HANG ANY FURTHER WEST. A MUCH WARMER DAY APPEARS TO BE ON TAP TOMORROW FOR THE PLAINS WITH WESTERLY DOWNSLOPE FLOW...AND 700 MILLIBAR TEMPS AROUND 8-10 DEG C. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 354 PM MDT FRI MAY 1 2015 THIS PERIOD WILL BE DOMINATED BY GENERALLY CONSISTENT SOUTHWEST FLOW ACROSS THE INTERMOUNTAIN WEST AS YET ANOTHER LARGE SCALE TROUGH IS CARVED INTO THE WRN CONUS. MOISTURE ADVECTION ALONG WITH DIFFICULT TO TIME SHORTWAVES EMBEDDED WTIHIN THIS FLOW WILL SET THE STAGE FOR A RELATIVELY UNSETTLED PERIOD. THIS BEGINS ON SUNDAY/MONDAY AS WEAK SFC BOUNDARY SETTLES SOUTH ACROSS THE PLAINS HANGING UP AROUND THE FRONT RANGE. MEANWHILE...RELATIVELY WEAK SHORTWAVE ENERGY WILL LIFT ACROSS THIS BOUNDARY AND WHEN COMBINED WITH WEAK INSTABILITY PROGS (SBCAPE 300- 500 J/KG) WILL PRODUCE AFTERNOON/EVENING CONVECTION BOTH DAYS. A STRONGER EJECTING TROUGH WILL MOVE THROUGH THE CWFA TUE/WED. BUT WITH MORE MOISTURE AND THICKER CLOUD CANOPY...INSTABILITIES ARE PROGD TO BE LESS. SOUTHWEST FLOW PERSISTS INTO THURSDAY WITH THE NEXT TROUGH SWINGING OUT OF THE DEEPENING WEST COAST TROUGH FOR FRIDAY OR FRIDAY NIGHT...DEPENDING ON THE MEDIUM RANGE GUIDANCE OF CHOICE. ISOLATED TO SCATTERED LATE DAY SHOWERS AND THUNDERSTORMS ARE HARD TO ARGUE WITH REALLY ANY DAY NEXT WEEK. SO HAVE KEPT PRECIP CHANCES FAIRLY BROAD BRUSH BUT NOT WIDESPREAD NEXT WEEK. SUNDAY WILL BE THE WARMEST DAY OF THE WEEK WITH HIGHS REACHING THE 60S/70S. HIGHS WILL FALL BACK INTO THE 60S GENERALLY MON-FRI. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1134 AM MDT FRI MAY 1 2015 AVIATION CONCERNS CENTER AROUND TIMING AND PLACEMENT OF CONVECTION THIS AFTERNOON AND EARLY EVENING...WHILE CAN ALWAYS BE A TRICKY. ALL SITES WITH THE EXCEPTION OF KCYS WILL BEGIN THE PERIOD IN VFR. PESKY STRATOCU DECK WILL KEEP BKN020-030 AGL IN PLACE AT KCYS AT LEAST FOR THE NEXT HOUR OR TWO. LATEST HRRR INITIATE -SHRA/-TSRA DEVELOPMENT ALONG THE DIFFERENTIAL HEATING AXIS (NR THE LARAMIE RANGE W OF KCYS) BETWEEN THIS STRATOCU DECK AND THE CLEARING TO THE WEST 20-21Z. CONFIDENCE HAS INCREASED ENOUGH TO ADD A TEMPO -TSRA GROUP INTO KCYS. CONFIDENCE IS LOWER WEST OF THIS AREA OF DIFFERENTIAL HEATING...SO HAVE KEPT VCTS IN KCYS. HAVE ADDED VCTS TO THE NEBRASKA PANHANDLE SITES AS WELL LATER THIS AFTERNOON AS WHATEVER CONVECTION DOES MANAGE TO DEVELOP TRANSLATES EAST. IF THIS ACTIVITY DOES IMPACT AN AIRIFIELD...EXPECT MVFR CIGS/VSBYS ALONG WITH BRIEF +RA...THE POTENTIAL FROM SMALL GS ALONG WITH GUSTY WINDS. AM NOT CONFIDENT ENOUGH IN TIMING OR PLACEMENT TO INCLUDE IN THE TAF...BUT WILL BE MONITORING RADAR TRENDS CLOSELY THIS AFTERNOON. && .FIRE WEATHER... ISSUED AT 354 PM MDT FRI MAY 1 2015 FIRE WEATHER CONCERNS WILL BE ON THE LOW SIDE WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS. WHILE ANY GIVEN STORM MAY PRODUCE GUSTY AND ERRATIC WINDS...NO DRY LIGHTNING IS EXPECTED. AFTERNOON RELATIVE HUMIDITY VALUES SHOULD REMAIN ABOVE 15 PERCENT. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ SHORT TERM...CLH LONG TERM...CAH AVIATION...CAH FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1134 AM MDT FRI MAY 1 2015 .UPDATE... ISSUED AT 1048 AM MDT FRI MAY 1 2015 AREA WEBCAMS AND VISIBLE SATELLITE IMAGERY SHOW FOG AND/OR LOW STRATUS RAPIDLY DIMINISHING ACROSS PORTIONS OF CARBON AND ALBANY COUNTIES THIS AM. CLOUD COVER HAS BEEN SLOW TO ERODE OVER THE CO FRONT RANGE WITH WEAK LLVL UPSLOPE...BUT CLOUDS ARE THINNING AND LLVL MIXING SHOULD GIVE WAY TO AT LEAST PARTLY SUNNY SKIES AS WE HEAD INTO THE AFTERNOON. OUR ATTENTION THEN SHIFTS TO CONVECTIVE POTENTIAL LATER TODAY. FORCING IS NOT AS PRONOUNCED AS PREVIOUS DAYS...BUT INSTABILITY SHOULD BE THERE WITH STEEP MIDLEVEL LAPSE RATES AND GOOD LLVL MOISTURE WITH SURFACE DEWPOINTS IN THE MID 40S. IF WE CAN BREAK OUT OF THE CLOUDS...OUR LOCAL WRF SUGGESTS SBCAPE NEAR 750-1000 J/KG. 0-6KM SHEAR VECTORS ARE WESTERLY AT AROUND 40 KTS...SUPPORTING POTENTIAL FOR ROTATING UPDRAFTS AND HAIL PRODUCTION. THE HRRR INITIATES CONVECTION AROUND 20Z OVER ALBANY AND LARAMIE COUNTIES...SO WENT AHEAD AND INCREASED POPS INTO THE LIKELY CATEGORY. ALSO ADDED SMALL HAIL AND GUSTY WINDS GIVEN THE THERMODYNAMIC/KINEMATIC ENVIRONMENT. WE COULD HAVE A SEVERE STORM OR TWO...BUT OPTED NOT TO MENTION IN THE GRIDS AS UNCERTAINTIES REMAIN WITH HOW CLOUDS WILL IMPACT COVERAGE OF STRONGER STORMS. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 300 AM MDT FRI MAY 1 2015 PATTERN WILL BE CHARACTERIZED BY A ZONAL FLOW ALOFT WITH SEVERAL WEAK IMPULSES PASSING ACROSS THE CWA IN THIS FLOW PATTERN. A SFC BOUNDARY WILL REMAIN BANKED UP ALONG THE HIGHER TERRAIN OF SE WYOMING TODAY BEFORE ERODING EASTWARD OVERNIGHT INTO SATURDAY. THIS BOUNDARY SHOULD INTERACT WITH THESE WEAK DISTURBANCES AND SOME INSTABILITY TO PRODUCE SCTD SHOWERS AND A FEW STORMS MAINLY OVER SE WYOMING TODAY. CAPE VALUES RANGE FROM ABOUT 500-1000J/KG AGAINST THE LARAMIE RANGE THIS AFTERNOON BUT SHEAR VALUES RATHER LOW SO A FEW STRONGER STORMS POSSIBLE. ACTIVITY SHOULD MOVE OUT/DISSIPATE THIS EVENING LEAVING A QUIET NIGHT TONIGHT. MORE OF THE SAME EXPECTED FOR SATURDAY AND SUNDAY EXCEPT AFTERNOON AND EVENING CONVECTION SHOULD MAKE MORE PROGRESS EASTWARD AS THE SFC BOUNDARY SHIFTS EAST. CAPE VALUES MUCH LESS OVERALL EXCEPT OVER PARTS OF THE PANHANDLE WHERE THEY EXCEED 1500 J/KG LATE IN THE MORNING BEFORE SHIFTING EAST OF THE CWA. WARMER TEMPS FOR SATURDAY THEN THE NEXT COOL FRONT WILL PASS ACROSS EARLY SUNDAY RESULTING IN ABOUT 5-15 DEGREES OF COOLING...GREATEST OVER THE PANHANDLE. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 300 AM MDT FRI MAY 1 2015 MUCH OF THE LONG TERM REMAINS UNSETTLED AS GUIDANCE CONTINUES TO SHOW ALMOST DAILY PRECIP CHANCES OVER THE CWFA. AREA REMAINS UNDER EASTERLY TO SOUTHEASTERLY UPSLOPE FLOW SUNDAY NIGHT INTO MONDAY AS A SURFACE HIGH OVER WESTERN SOUTH DAKOTA REMAINS NEARLY STATIONARY. EACH DAY THERE LOOKS TO BE PIECES OF ENERGY BEING DRAWN NORTH INTO THE AREA FROM THE DESERT SOUTHWEST THAT INTERACTS WITH A BOUNDARY THAT IS STALLED ALONG THE LARAMIE RANGE. MONDAY AFTERNOON...CONVECTION IS CONCENTRATED MAINLY ACROSS OUR WESTERN ZONES...BUT AS THE LOW PRESSURE SYSTEM MOVES INTO COLORADO TUESDAY...OUR EASTERN ZONES GET SOME PRETTY GOOD RAINFALL. BEST PRECIP CHANCES APPEAR TO BE ALONG THE WYOMING/COLORADO BORDER ALONG INTERSTATE 80. UPPER LOW SLOW TO MOVE OUT OF COLORADO AND WE SHOULD SEE WIDESPREAD CHANCES FOR SHOWERS AND THUNDERSTORMS WEDNESDAY ACROSS THE ENTIRE CWFA. FINALLY BY THURSDAY...UPPER LOW MOVES NORTHEAST INTO THE DAKOTAS. NOT MUCH OF A BREAK IN PRECIP THOUGH AS A SECOND SHORTWAVE MOVES IN BEHIND THIS ONE FOR FRIDAY. AREA WILL CONTINUE TO SEE ABOVE NORMAL CHANCES FOR MUCH NEEDED RAINFALL INTO THE END OF THE WEEK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1134 AM MDT FRI MAY 1 2015 AVIATION CONCERNS CENTER AROUND TIMING AND PLACEMENT OF CONVECTION THIS AFTERNOON AND EARLY EVENING...WHILE CAN ALWAYS BE A TRICKY. ALL SITES WITH THE EXCEPTION OF KCYS WILL BEGIN THE PERIOD IN VFR. PESKY STRATOCU DECK WILL KEEP BKN020-030 AGL IN PLACE AT KCYS AT LEAST FOR THE NEXT HOUR OR TWO. LATEST HRRR INITIATE -SHRA/-TSRA DEVELOPMENT ALONG THE DIFFERENTIAL HEATING AXIS (NR THE LARAMIE RANGE W OF KCYS) BETWEEN THIS STRATOCU DECK AND THE CLEARING TO THE WEST 20-21Z. CONFIDENCE HAS INCREASED ENOUGH TO ADD A TEMPO -TSRA GROUP INTO KCYS. CONFIDENCE IS LOWER WEST OF THIS AREA OF DIFFERENTIAL HEATING...SO HAVE KEPT VCTS IN KCYS. HAVE ADDED VCTS TO THE NEBRASKA PANHANDLE SITES AS WELL LATER THIS AFTERNOON AS WHATEVER CONVECTION DOES MANAGE TO DEVELOP TRANSLATES EAST. IF THIS ACTIVITY DOES IMPACT AN AIRIFIELD...EXPECT MVFR CIGS/VSBYS ALONG WITH BRIEF +RA...THE POTENTIAL FROM SMALL GS ALONG WITH GUSTY WINDS. AM NOT CONFIDENT ENOUGH IN TIMING OR PLACEMENT TO INCLUDE IN THE TAF...BUT WILL BE MONITORING RADAR TRENDS CLOSELY THIS AFTERNOON. && .FIRE WEATHER... ISSUED AT 300 AM MDT FRI MAY 1 2015 CONCERNS TO REMAIN LOW THROUGH THE WEEKEND INTO EARLY NEXT WEEK WITH NEARLY DAILY CHANCES FOR SHOWERS AND A FEW STORMS...BUT NO DRY LIGHTNING. WEATHER FACTORS REMAINING NON-CRITICAL. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...CLH SHORT TERM...RE LONG TERM...GCC AVIATION...CAH FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1117 AM MDT FRI MAY 1 2015 .UPDATE... ISSUED AT 1048 AM MDT FRI MAY 1 2015 AREA WEBCAMS AND VISIBLE SATELLITE IMAGERY SHOW FOG AND/OR LOW STRATUS RAPIDLY DIMINISHING ACROSS PORTIONS OF CARBON AND ALBANY COUNTIES THIS AM. CLOUD COVER HAS BEEN SLOW TO ERODE OVER THE CO FRONT RANGE WITH WEAK LLVL UPSLOPE...BUT CLOUDS ARE THINNING AND LLVL MIXING SHOULD GIVE WAY TO AT LEAST PARTLY SUNNY SKIES AS WE HEAD INTO THE AFTERNOON. OUR ATTENTION THEN SHIFTS TO CONVECTIVE POTENTIAL LATER TODAY. FORCING IS NOT AS PRONOUNCED AS PREVIOUS DAYS...BUT INSTABILITY SHOULD BE THERE WITH STEEP MIDLEVEL LAPSE RATES AND GOOD LLVL MOISTURE WITH SURFACE DEWPOINTS IN THE MID 40S. IF WE CAN BREAK OUT OF THE CLOUDS...OUR LOCAL WRF SUGGESTS SBCAPE NEAR 750-1000 J/KG. 0-6KM SHEAR VECTORS ARE WESTERLY AT AROUND 40 KTS...SUPPORTING POTENTIAL FOR ROTATING UPDRAFTS AND HAIL PRODUCTION. THE HRRR INITIATES CONVECTION AROUND 20Z OVER ALBANY AND LARAMIE COUNTIES...SO WENT AHEAD AND INCREASED POPS INTO THE LIKELY CATEGORY. ALSO ADDED SMALL HAIL AND GUSTY WINDS GIVEN THE THERMODYNAMIC/KINEMATIC ENVIRONMENT. WE COULD HAVE A SEVERE STORM OR TWO...BUT OPTED NOT TO MENTION IN THE GRIDS AS UNCERTAINTIES REMAIN WITH HOW CLOUDS WILL IMPACT COVERAGE OF STRONGER STORMS. && .SHORT TERM...(TODAY THROUGH SUNDAY) ISSUED AT 300 AM MDT FRI MAY 1 2015 PATTERN WILL BE CHARACTERIZED BY A ZONAL FLOW ALOFT WITH SEVERAL WEAK IMPULSES PASSING ACROSS THE CWA IN THIS FLOW PATTERN. A SFC BOUNDARY WILL REMAIN BANKED UP ALONG THE HIGHER TERRAIN OF SE WYOMING TODAY BEFORE ERODING EASTWARD OVERNIGHT INTO SATURDAY. THIS BOUNDARY SHOULD INTERACT WITH THESE WEAK DISTURBANCES AND SOME INSTABILITY TO PRODUCE SCTD SHOWERS AND A FEW STORMS MAINLY OVER SE WYOMING TODAY. CAPE VALUES RANGE FROM ABOUT 500-1000J/KG AGAINST THE LARAMIE RANGE THIS AFTERNOON BUT SHEAR VALUES RATHER LOW SO A FEW STRONGER STORMS POSSIBLE. ACTIVITY SHOULD MOVE OUT/DISSIPATE THIS EVENING LEAVING A QUIET NIGHT TONIGHT. MORE OF THE SAME EXPECTED FOR SATURDAY AND SUNDAY EXCEPT AFTERNOON AND EVENING CONVECTION SHOULD MAKE MORE PROGRESS EASTWARD AS THE SFC BOUNDARY SHIFTS EAST. CAPE VALUES MUCH LESS OVERALL EXCEPT OVER PARTS OF THE PANHANDLE WHERE THEY EXCEED 1500 J/KG LATE IN THE MORNING BEFORE SHIFTING EAST OF THE CWA. WARMER TEMPS FOR SATURDAY THEN THE NEXT COOL FRONT WILL PASS ACROSS EARLY SUNDAY RESULTING IN ABOUT 5-15 DEGREES OF COOLING...GREATEST OVER THE PANHANDLE. .LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY) ISSUED AT 300 AM MDT FRI MAY 1 2015 MUCH OF THE LONG TERM REMAINS UNSETTLED AS GUIDANCE CONTINUES TO SHOW ALMOST DAILY PRECIP CHANCES OVER THE CWFA. AREA REMAINS UNDER EASTERLY TO SOUTHEASTERLY UPSLOPE FLOW SUNDAY NIGHT INTO MONDAY AS A SURFACE HIGH OVER WESTERN SOUTH DAKOTA REMAINS NEARLY STATIONARY. EACH DAY THERE LOOKS TO BE PIECES OF ENERGY BEING DRAWN NORTH INTO THE AREA FROM THE DESERT SOUTHWEST THAT INTERACTS WITH A BOUNDARY THAT IS STALLED ALONG THE LARAMIE RANGE. MONDAY AFTERNOON...CONVECTION IS CONCENTRATED MAINLY ACROSS OUR WESTERN ZONES...BUT AS THE LOW PRESSURE SYSTEM MOVES INTO COLORADO TUESDAY...OUR EASTERN ZONES GET SOME PRETTY GOOD RAINFALL. BEST PRECIP CHANCES APPEAR TO BE ALONG THE WYOMING/COLORADO BORDER ALONG INTERSTATE 80. UPPER LOW SLOW TO MOVE OUT OF COLORADO AND WE SHOULD SEE WIDESPREAD CHANCES FOR SHOWERS AND THUNDERSTORMS WEDNESDAY ACROSS THE ENTIRE CWFA. FINALLY BY THURSDAY...UPPER LOW MOVES NORTHEAST INTO THE DAKOTAS. NOT MUCH OF A BREAK IN PRECIP THOUGH AS A SECOND SHORTWAVE MOVES IN BEHIND THIS ONE FOR FRIDAY. AREA WILL CONTINUE TO SEE ABOVE NORMAL CHANCES FOR MUCH NEEDED RAINFALL INTO THE END OF THE WEEK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 647 AM MDT FRI MAY 1 2015 PATCHY FOG AND LOW CLOUDS RESIDE WEST OF THE LARAMIE RANGE THIS MORNING. KRWL DOWN NOW IN STRATUS THAT IS EXPECTED TO CONTINUE UNTIL 15Z OR SO. MVFR CONDITIONS HERE AT KCYS SHOULD IMPROVE BY MID MORNING WITH HEATING. AFTERNOON CONVECTION FOR KCYS...KLAR AND POSSIBLY THE SOUTHERN PANHANDLE AIRPORTS. && .FIRE WEATHER... ISSUED AT 300 AM MDT FRI MAY 1 2015 CONCERNS TO REMAIN LOW THROUGH THE WEEKEND INTO EARLY NEXT WEEK WITH NEARLY DAILY CHANCES FOR SHOWERS AND A FEW STORMS...BUT NO DRY LIGHTNING. WEATHER FACTORS REMAINING NON-CRITICAL. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...CLH SHORT TERM...RE LONG TERM...GCC AVIATION...GCC FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
339 AM CDT SUN MAY 3 2015 .SHORT TERM...(TODAY) ISSUED AT 338 AM CDT SUN MAY 3 2015 SURFACE TROUGH AND FRONTAL BOUNDARY REMAIN WELL OFF TO THE NORTHWEST THIS MORNING...DRAPED FROM SD NORTHEAST THROUGH MN. THIS WILL BECOME THE FOCUS FOR CONVECTIVE ACTIVITY LATER TODAY AS IT MOVES CLOSER TO CENTRAL IL IN THE LATE AFTERNOON. THIS MORNING A SHORTWAVE EVIDENT ON WATER VAPOR IMAGERY OVER CENTRAL IL CONTINUES TO PRODUCE A FEW SHOWERS...EXPECTED TO MOVE EASTWARD AND DISSIPATE LATER THIS MORNING IN EAST CENTRAL IL ACCORDING TO LATEST HRRR RUN. ANOTHER SHORTWAVE OVER WEST IA IS EXPECTED TO TRACK ENE AND PASS BY THE CENTRAL IL FORECAST AREA TO THE NORTH. WITH GENERAL SUBSIDENCE INDICATED ACROSS THE AREA...HAVE KEPT THE FORECAST DRY LATE MORNING THROUGH LATE AFTERNOON/EARLY EVENING ONCE THE INITIAL ROUND OF MORNING SHOWERS PASSES THROUGH. LOW LEVEL SOUTHERLY FLOW WILL KEEP THE WARMING TREND GOING FOR TODAY WITH HIGHS REACHING AROUND 80 DEGREES. FORECAST SOUNDINGS INDICATE BOUNDARY LAYER MOMENTUM CAPABLE OF PRODUCING GUSTS 20-25 MPH FROM I-70 NORTHWARD...WITH SUSTAINED SOUTHERLY WINDS 12-18 MPH. && .LONG TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 338 AM CDT SUN MAY 3 2015 NOT A LOT OF CHANGES IN THE FORECAST. MAJORITY OF FORECAST REVOLVES AROUND A SLOWING/STALLED FRONTAL BOUNDARY ACROSS THE REGION FOR TONIGHT AND THROUGH TOMORROW BEFORE BEING EDGED TO THE NORTH BEFORE ANOTHER SYSTEM SPINS UP OVER THE PLAINS AND MOVES INTO THE REGION. FOR TONIGHT, THE FRONTAL BOUNDARY SETTLING IN JUST TO THE NORTHWEST WILL PROVIDE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS FOR THE AREA...SETTLING INTO THE NORTHERN HALF OF THE STATE AND BECOMING HUNG UP IN QUASI ZONAL FLOW ALOFT. BEST CHANCES FOR PRECIP REMAIN IN THE NORTHERN HALF OF THE STATE PROVIDING SOME FOCUS FOR STORM DEVELOPMENT. MODELS HAVE TRENDED A LITTLE MORE SCATTERED IN THE QPF FIELDS, ALTHOUGH THE NORTHERN HALF OF THE STATE STILL SEEMS PRIMED FOR THE BEST CHANCES OF PRECIP THROUGH MONDAY NIGHT, SPECIFICALLY THE AREAS WHERE THE BOUNDARY STALLS. SPC HAS KEPT THE NORTHERN HALF OF THE CWA IN A MARGINAL RISK FOR STORMS INVOF THE BOUNDARY ON MONDAY. CLUSTERS OF STORMS NEAR A WEAK BOUNDARY LOOKING BORDERLINE AT THIS POINT, BUT IN AN AREA OF CONTINUING WARM AIR ADVECTION PROVIDING POTENTIAL INSTABILITY JUST SOUTH OF THE BOUNDARY THAT WILL SLOWLY BE SETTLING SOUTH INTO THE WARMER AND MORE BUOYANT AIR. A RIDGE BEGINS TO BUILD INTO THE MIDWEST FROM THE SOUTHEAST...WITH ENOUGH SUBSIDENCE IN THE REGION OF THE RIDGE AXIS TO ERODE SHOWER CHANCES AT LEAST TUES NIGHT THROUGH WED NIGHT. ANOTHER PATTERN SHIFT TAKES HOLD FOR THE LATER HALF OF THE WEEK, SETTING UP MORE OF A SOUTHWESTERLY FLOW AND AN ACTIVE WEATHER PATTERN AGAIN AS WAVES CONTINUE TO RIPPLE AROUND THE SWRN LOW AND INTO THE MIDWEST. A RATHER WET FORECAST OVERALL, WITH SEVERAL DIFFERENT PATTERNS ESTABLISHING THEMSELVES...AND KEEPING SHOWERS AND THUNDERSTORMS IN THE OUTLOOK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1150 PM CDT SAT MAY 2 2015 ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TO MOVE ACROSS THE AREA OVERNIGHT. SO WILL BE KEEPING VCSH IN OVERNIGHT FOR ALL SITES. OTHERWISE, VFR AND MID LEVEL CIGS WILL BE HAD AT ALL SITES OVERNIGHT. HRRR MODEL ENDS THE PCPN TOWARD EARLY MORNING BUT MID LEVEL CIGS CONTINUE FOR A FEW HOURS. THEN CLOUDS WILL SCATTER OUT. WILL HAVE HIGH CIRRUS WHICH WILL BE THE BLOW OFF FROM THE STORMS CURRENTLY WELL WEST OF THE AREA. NOT EXPECTING TO SEE ANY OF THE PCPN ASSOCIATED WITH THESE STORMS IN THE AREA TOMORROW, BUT MODELS ADVECT SOME REMNANTS OF THESE STORMS INTO NORTHERN IL. WINDS WILL BE SOUTH TO SOUTHWEST THROUGH THE PERIOD WITH STILL THINKING OF SOME GUSTS AROUND 22-25KTS TOMORROW LATE MORNING THROUGH AFTERNOON AFTER THE CLOUDS CLEAR AND GOOD MIXING TAKES PLACE. MAY SEE SOME LLWS TOMORROW NIGHT BUT SOME UNCERTAINTY, SO NOT GOING TO PUT IN TAFS AT THIS POINT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ONTON LONG TERM...HJS AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1150 PM CDT SAT MAY 2 2015 .UPDATE... ISSUED AT 857 PM CDT SAT MAY 2 2015 ISOLATED TO SCATTERED SHOWERS ARE MOVING INTO THE AREA FROM THE WEST AND IT APPEARS THEY WILL CONTINUE TO MOVE EAST THROUGH THE NIGHT. MODELS CONTINUE TO SHOW THIS AREA WEAKENING AS IT MOVES EAST, AND IR SATELLITE LOOP SEEMS TO SUPPORT THIS WITH CLOUD TOPS WARMING ACROSS THE WHOLE AREA OF WHERE THE SHOWERS ARE. ITS ALSO MOVING AWAY INTO A DRIER AIRMASS. HAVE TRIED TO MAKE SOME ADJUSTMENTS TO POPS FOR REMAINDER OF THE NIGHT IN THE GRIDS. OTHER PARAMETERS SHOULD BE OK OR RELATIVELY CLOSE TO CURRENT AND EXPECTED CONDITIONS REMAINDER OF THE NIGHT. OTHER SHOWERS AND THUNDERSTORMS HAVE BEEN DEVELOPING FURTHER WEST IN THE PLAINS. HRRR MODEL SHOWS THESE MAKING THEIR WAY INT WESTERN AND NORTHWESTERN IL TOMORROW MORNING. WILL BE TAKING A CLOSER LOOK AT THIS OVER THE NEXT SEVERAL HOURS. ANOTHER UPDATE MAY BE NEEDED LATER THIS EVENING BEFORE NEW FORECAST PACKAGE COMES OUT AT 4AM. UPDATE TO FORECAST WILL BE COMING SHORTLY. && .SHORT TERM...(TONIGHT) ISSUED AT 255 PM CDT SAT MAY 2 2015 A WEAK SHORT WAVE OVER WESTERN IA WILL TRACK EAST TO THE IL/IA BORDER BY MIDNIGHT AND WEAKEN AS IT MOVES ACROSS CENTRAL AND NORTHERN IL OVERNIGHT. AN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS OVER NORTHERN MO AND SOUTHERN IA WILL CONTINUE TO TRACK EASTWARD INTO WEST CENTRAL IL EARLY THIS EVENING BETWEEN 6-8 PM AND INTO CENTRAL IL LATER THIS EVENING AND OVERNIGHT AS SHOWERS BECOME MORE ISOLATED. HAVE 20-30% CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS FROM I-55 NW AFTER SUNSET TONIGHT AND LINGERING ISOLATED LIGHT SHOWERS UNTIL MID SUNDAY MORNING NORTH OF I-72 UNTIL WEAKENING SHORT WAVE PASSES EAST OF IL INTO WESTERN IN BY MIDDAY SUNDAY. MID AND HIGH CLOUDS WILL CONTINUE TO INCREASE FROM THE WEST LATE THIS AFTERNOON AND EVENING WITH SOUTHEAST IL SEEING LESS CLOUD COVER TONIGHT SINCE CLOSER TO HIGH PRESSURE RIDGE OVER SOUTHEAST STATES. LOWS TONIGHT IN THE LOW TO MID 50S WITH COOLEST READINGS NEAR WABASH RIVER WHERE LIGHTER WINDS AND LESS CLOUD COVER TONIGHT. SSW WINDS 7- 14 MPH AND GUSTS 15-20 MPH THIS AFTERNOON TO DIMINISH LESS THAN 10 MPH AFTER SUNSET AND VEER SSE. .LONG TERM...(SUNDAY THROUGH SATURDAY) ISSUED AT 255 PM CDT SAT MAY 2 2015 IOWA SHORTWAVE FORECAST BY MODELS TO TRACK ACROSS THE AREA OVERNIGHT AND INTO THE MORNING HOURS OF SUNDAY BRINGING ISOLATED SHOWERS TO PARTS OF THE FORECAST AREA. SOUNDINGS STILL SHOWING A VERY DRY PROFILE BELOW 725 MB (~8500 FEET) INTO SUNDAY MORNING BEFORE THE WAVE SHIFTS OFF TO OUR EAST DURING THE MORNING. WILL KEEP SLIGHTS GOING FOR A FEW HOURS IN THE MORNING BEFORE THE WAVE MOVES OUT OF THE AREA. OUR ATTENTION THEN TURNS TO A NORTHERN STREAM SHORTWAVE THAT WILL DRAG A COLD FRONT SOUTHEAST INTO THE LOWER GREAT LAKES LATE SUNDAY AND INTO MONDAY INCREASING THE CHANCES FOR MORE WIDESPREAD SHOWERS AND STORMS...ESPECIALLY OVER THE NORTHERN HALF OF THE FORECAST AREA WHERE THE BOUNDARY IS FORECAST TO BECOME STATIONARY. AFTER OUR SLIGHT CHANCES SUNDAY MORNING...THE REST OF THE DAY LOOKS QUIET AND WARM WITH A GUSTY SOUTH TO SOUTHWEST WIND HELPING TO PUSH AFTERNOON TEMPS INTO THE UPPER 70S TO LOWER 80S. POPS START TO RAMP UP SUNDAY NIGHT ACROSS THE FAR NORTHWEST AS THE BOUNDARY EDGES SLOWLY SOUTHEAST WITH MODELS TRENDING SLOWER WITH THE FRONTAL BOUNDARY AND QPF ALONG IT. MAY HAVE TO SLOW THE ONSET OF THE SHOWERS EVEN MORE IF THESE TRENDS CONTINUE. BETTER LOW LEVEL JET SUPPORT AND 850 MB THETA-E ADVECTION REMAINS OUT TO OUR NORTHWEST LATE SUNDAY NIGHT WITH MOST MODELS SUGGESTING THAT A CLUSTER OF STORMS...AT LEAST WHAT`S LEFT OF THEM...WILL APPROACH OUR FAR NORTHWEST COUNTIES WELL AFTER MIDNIGHT SUNDAY NIGHT. THE SHOWER AND THUNDERSTORM CHANCES WILL CONTINUE TO SPREAD SLOWLY SOUTHEAST ON MONDAY AND INTO MONDAY NIGHT WITH THE HIGHER THREAT BEING AGAIN WHERE THE BOUNDARY IS EXPECTED TO BECOME STATIONARY... WHICH AT THIS TIME LOOKS TO BE NORTH OF I-72. FORECAST SOUNDINGS SHOWING MIXED LAYER CAPES OF AROUND 1500 J/KG MONDAY AFTERNOON INTO EARLY MONDAY EVENING WITH THE STRONGER 500 MB WIND FLOW TO OUR NORTH WITH 30-35 KTS FORECAST. SPC HAS A LARGE AREA OF MARGINAL RISK FOR SEVERE STORMS MONDAY AFTERNOON AND EVENING STRETCHING FROM THE SOUTHERN PLAINS UP ACROSS THE NORTHERN HALF OF OUR CWA. SEVERE PARAMETERS BORDERLINE AT THIS TIME BUT WITH THE BOUNDARY IN THE AREA AND FORECAST CONVECTIVE TEMPS AROUND 80...MULTI-CELL STORMS SHOULD DEVELOP DURING THE AFTERNOON AND CONTINUE INTO THE EVENING WITH THE POSSIBILITY FOR SOME GUSTY WINDS...HAIL AND HEAVY RAINFALL WITH SOME OF THE MORE ORGANIZED CLUSTERS OF STORMS THAT FORM ALONG THE STALLED FRONTAL BOUNDARY. MODELS SUGGEST THE BOUNDARY WILL SHIFT NORTH OF THE AREA STARTING ON TUESDAY AS UPPER LEVEL HEIGHTS BUILD IN RESPONSE TO A RATHER VIGOROUS UPPER WAVE THAT WILL BE PUSHING ACROSS THE SOUTHERN ROCKIES AND EVENTUALLY SWING NORTHEAST INTO THE PLAINS BY MID TO LATE IN THE UPCOMING WORK WEEK. WILL INDICATE A BIT OF A LULL IN THE SHOWER AND STORM CHANCES UNTIL LATE THURSDAY OR FRIDAY WHEN THE WAVE WILL APPROACH OUR AREA. TEMPERATURES LOOK TO BE ABOVE NORMAL THRU THE WORK WEEK WITH AFTERNOON HIGHS CLIMBING INTO THE UPPER 70S TO LOWER 80S...WHILE EARLY MORNING LOWS ONLY DROP OFF INTO THE UPPER 50S TO LOWER 60S TUESDAY MORNING...WITH MOST OF OUR AREA SEEING LOW TEMPERATURES IN THE LOW TO MID 60S FOR THE REMAINDER OF THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1150 PM CDT SAT MAY 2 2015 ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TO MOVE ACROSS THE AREA OVERNIGHT. SO WILL BE KEEPING VCSH IN OVERNIGHT FOR ALL SITES. OTHERWISE, VFR AND MID LEVEL CIGS WILL BE HAD AT ALL SITES OVERNIGHT. HRRR MODEL ENDS THE PCPN TOWARD EARLY MORNING BUT MID LEVEL CIGS CONTINUE FOR A FEW HOURS. THEN CLOUDS WILL SCATTER OUT. WILL HAVE HIGH CIRRUS WHICH WILL BE THE BLOW OFF FROM THE STORMS CURRENTLY WELL WEST OF THE AREA. NOT EXPECTING TO SEE ANY OF THE PCPN ASSOCIATED WITH THESE STORMS IN THE AREA TOMORROW, BUT MODELS ADVECT SOME REMNANTS OF THESE STORMS INTO NORTHERN IL. WINDS WILL BE SOUTH TO SOUTHWEST THROUGH THE PERIOD WITH STILL THINKING OF SOME GUSTS AROUND 22-25KTS TOMORROW LATE MORNING THROUGH AFTERNOON AFTER THE CLOUDS CLEAR AND GOOD MIXING TAKES PLACE. MAY SEE SOME LLWS TOMORROW NIGHT BUT SOME UNCERTAINTY, SO NOT GOING TO PUT IN TAFS AT THIS POINT. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AUTEN SHORT TERM...07 LONG TERM...SMITH AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
404 AM CDT Sun May 3 2015 .SHORT TERM...(Today and Tonight) Issued at 346 AM CDT SUN MAY 3 2015 Isolated thunderstorms developed this morning shortly after 06Z in warm/moist advection within the low level jet. Vad wind profiles as well as water vapor imagery shows a mid level wave around 700 mb moving across central Kansas at 08Z. Latest runs of the HRRR and RAP move the isolated convection east into Missouri by 12Z-13Z. After this early morning round of convection, the rest of the day should be dry with clouds gradually decreasing through the early afternoon hours. Deep mixing today along with warm advection will yield highs in the low to mid 80s. Main thermal axis sets up from New Mexico through north central Kansas into northeast Nebraska today. Winds will increase by mid morning as pressure gradient increases. Surface front moves southeast into western Kansas this afternoon while it moves little across Nebraska. Expect afternoon heating out west will overcome convective inhibition for scattered storms to develop. These will remain to the west of north central Kansas into the early evening hours. Models eject weak waves northeast across western Kansas into southern Nebraska overnight. Expect convection to fire along the front in Nebraska tonight with outflow pushing south into north central and northeast Kansas. Southerly low level jet will help to develop scattered showers and thunderstorms overnight. Shear is marginal 20 to 30 kts overnight with MUCAPE 800-1000 J/kg. Expect some strong storms are possible with a few severe storms not out of the question later this evening across north central Kansas. Hail and winds will be the main hazards. Lows tonight will be mild with readings in the lower 60s. .LONG TERM...(Monday through Saturday) Issued at 346 AM CDT SUN MAY 3 2015 A wet pattern looks to be setting up for this upcoming week with several chances for precipitation all the way into next weekend. By Monday, a mid-level ridge will stretch across the Southern Plains and southeastern U.S. with a surface low centered over southwest Kansas. Models show the associated cold front extending into north central Kansas and southeast Nebraska, however the last few models runs have shown this front becoming fairly stationary over northern Kansas Monday into Monday night, limiting the southeastern extent of precipitation chances across the CWA. As a result, have continued to diminish PoPs across far east central Kansas through that period with likely PoPs along the KS/NE border with the stationary boundary. There continues to be the potential for some strong to severe thunderstorms to develop along this stationary boundary Monday afternoon into Monday evening as storms should be surface-based due to little to no inhibition present. The NAM continues to be the most aggressive with the amount of available moisture, thus increasing the parameters for severe thunderstorms. However, CAPE values could reach upwards of 1000-2000 J/kg with decent low-level lapse rates. However, 0-6km bulk shear continues to look fairly weak with most models showing upwards of only about 30kts. The main concern with any strong to severe storms will likely be some large hail and potentially some locally heavy rain as thunderstorms may train across north central Kansas into the evening and overnight hours with the low-level jet looking to be parallel to the boundary. The mid-level ridge should stretch further northward into the Central Plains Monday night into Tuesday, helping to push the cold front northward into Nebraska and further limiting the precipitation potential across the southeastern portions of the forecast area. At this time, Tuesday looks to show the best potential for being dry across much of the forecast area. However, focus quickly shifts to the southwest where a mid-level trough will be beginning to lift northeastward across the High Plains through Wednesday and into the Northern Plains by Wednesday night. At the surface, a low pressure system will strengthen across the High Plains but looks to become anchored over that region through mid to late week, resulting in persistent southerly surface winds advecting warm, moist air into the region. The combination of this steady stream of moisture and a frontal boundary that will likely remain hung up just west of the forecast area through much of the remainder of the week will help to support continued scattered shower and thunderstorm chances through the end of the week. While there is decent model agreement with the timing and tracking of the mid-level trough and the development of weak embedded waves within the pattern by late week, there is less agreement with the surface features in when the associated cold front will become tilted enough to move into the forecast area during the latter part of the week. Due to the low confidence in this boundary placement, have lowered PoPs some from the consensus blend but still have chance PoPs in for the entire forecast area through Saturday. This fairly stationary surface pattern should result in fairly similar temperatures throughout the week with highs in the 70s/near 80, lows in the upper 50s/low 60s, and dewpoints in the 50s and 60s. && .AVIATION...(For the 06Z TAFs through 06Z Sunday Night) Issued at 1126 PM CDT SAT MAY 2 2015 VFR conditions expected through most of the taf period. There is a slight chance for showers and storms towards the end of the period, but confidence is low on timing at this point. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...Hennecke AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
321 AM CDT SUN MAY 3 2015 ...UPDATED SHORT TERM AND LONG TERM SECTIONS... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 320 AM CDT SUN MAY 3 2015 THE MAIN CONCERN FOR THE SHORT TERM IS CONVECTIVE CHANCES, COVERAGE, AND STRENGTH FOR LATE THIS AFTERNOON INTO THE EVENING. ON THE SYNOPTIC SCALE, A RATHER WEAK WEST-TO-EAST FLOW WAS FOUND IN THE MID AND UPPER TROPOSPHERE, WITH 500MB FLOW AVERAGING ABOUT 15 TO 20 KNOTS ACROSS THE CENTRAL ROCKIES AND PLAINS WITH 250MB FLOW NOT MUCH STRONGER AT 25 TO 30 KNOTS. THIS IS MORE LIKE A LATE JUNE/EARLY JULY FLOW REGIME. AS A RESULT, THE CONVECTION THAT IS EXPECTED TO DEVELOP LATE THIS AFTERNOON WILL BEHAVE MORE LIKE LATE JUNE/JULY STORMS: SLOW MOVING, AND MARGINAL-AT-BEST SEVERE WEATHER PROSPECTS. THUNDERSTORMS WILL DEVELOP IN THE DEEPLY MIXED AIRMASS THAT WILL DEVELOP ALONG AND WEST OF THE LEE TROUGH AXIS/NEBULOUS DRYLINE. THE CONVERGENCE WILL NOT BE ALL THAT STRONG, BUT THE LOWER TO MID TROPOSPHERIC LAPSE RATES OF EARLY MAY WILL BE STEEP ENOUGH SUCH THAT EVEN WEAK CONVERGENCE WILL AID IN THUNDERSTORM DEVELOPMENT ALONG THE WEAK DRYLINE/LEE TROUGH. WHEN COMPARED AGAINST THE GFS, ECMWF, AND WRF-ARW, THE NAM12/NMMB SURFACE DEWPOINTS APPEAR TO BE TOO AMBITIOUS WITH MID 50S DEWPOINTS AS FAR WEST AS HIGHWAY 283 BY LATE AFTERNOON, RESULTING IN LARGE AREA OF 2000+ J/KG SBCAPE. THERE WILL LIKELY BE A BIT MORE MIXING THAN WHAT THE NAM12 SHOWS WITH TEMPERATURES WARMING WELL INTO THE MID TO UPPER 80S AND THE LACK OF ANY EASTERLY COMPONENT WIND. THAT SAID, THE EARLY RUNS OF THE RAP13 AND HRRR APPEAR TO BE WHACKED OUT WITH SURFACE FLOW TOO VEERED OUT/WESTERLY COMPONENT WITH DEWPOINTS TANKING INTO THE UPPER 30S TO AROUND 40F FOR ALL OF SOUTHWEST KANSAS. BELIEVE THAT SOMETHING IN THE MIDDLE IS MORE REALISTIC IN TERMS OF WHAT WILL REALLY PAN OUT WITH THE SURFACE SETUP LATE THIS AFTERNOON. NEVERTHELESS, 1000 TO 1500 J/KG SBCAPE SHOULD BE REALIZED AHEAD OF THE DEVELOPING CONVECTION THIS AFTERNOON. THE GREATEST THREAT FROM ANY OF THE STORMS WILL BE SOME LOCALIZED DOWNBURST WIND GUSTS IN EXCESS OF 50 KNOTS/58 MPH GIVEN THE ANTICIPATED HIGH TEMPERATURE- DEWPOINT SPREADS APPROACHING 40F LATE THIS AFTERNOON. THE HAIL RISK LOOKS QUITE LOW GIVEN THE POOR CAPE-SHEAR COMBINATION AND LACK OF ANY UPPER TROPOSPHERIC FLOW TO SUPPORT MID-UPPER STORM-RELATIVE SHEAR. THE STRONGEST STORM WILL STILL BE CAPABLE OF QUARTER TO PERHAPS HALF-DOLLAR SIZE HAIL, THOUGH. THE FORECAST POPS OF 40 TO 50 PERCENT WILL COVER AREAS ALONG AND BETWEEN THE HIGHWAY 83 AND 283 CORRIDOR, INCLUDING SCOTT CITY, GARDEN, LIBERAL, NESS CITY, WAKEENEY, AND HAYS. ANTICIPATED SLOW STORM MOTIONS WILL RESULT IN LOCALIZED HEAVY RAINFALL, ESPECIALLY DURING THE EVENING WHEN UPSCALE GROWTH OCCURS BETWEEN 00-03Z. LOSS OF DIURNAL HEATING WILL LIKELY RESULT IN THE DEMISE OF CONVECTION BY 06Z MUCH LIKE WE HAVE SEEN OVER THE PAST COUPLE NIGHTS OUT ALONG THE KS-CO BORDER. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 320 AM CDT SUN MAY 3 2015 AN UPPER LEVEL LOW IS EXPECTED TO MOVE INTO THE DESERT SOUTHWEST SUNDAY INTO MONDAY THEN WEAKEN INTO AN OPEN WAVE AND CURLS NORTHEASTWARD INTO THE CENTRAL ROCKIES BY TUESDAY INTO TUESDAY NIGHT. THIS FEATURE THEN MOVES INTO THE CENTRAL PLAINS WEDNESDAY THEN INTO THE NORTHERN PLAINS THURSDAY. MOISTURE ABOVE WESTERN KANSAS WILL INCREASE AS THIS FEATURE APPROACHES LEADING TO INCREASING CLOUDS MONDAY WITH MOSTLY CLOUDY SKIES EXPECTED MONDAY NIGHT THROUGH TUESDAY NIGHT. A FRONTAL BOUNDARY AT THE SURFACE IS ANTICIPATED TO SPRAWL OUT ACROSS WEST CENTRAL KANSAS MONDAY THEN SHIFT NORTHWARD MONDAY NIGHT INTO TUESDAY AS A WARM FRONT. WINDS AHEAD OF THIS BOUNDARY WILL GENERALLY BE FROM A SOUTHERLY DIRECTION WITH WINDS BEHIND THIS BOUNDARY FROM MORE OF A NORTHERLY DIRECTION. A DOME OF HIGH PRESSURE WILL BE LOCATED ACROSS THE EASTERN UNITED STATES WITH TRAJECTORIES ON THE WEST SIDE BRINGING UP COPIOUS AMOUNTS OF MOISTURE FROM THE GULF INTO THE CENTRAL PLAINS. AS FOR PRECIPITATION CHANCES, THUNDERSTORMS MAY BE POSSIBLE ACROSS CENTRAL KANSAS MONDAY MORNING BUT SHOULD QUICKLY MOVE OUT OF THE CWA BY LATE MORNING. ADDITIONAL THUNDERSTORMS ARE PROGGED TO DEVELOP ACROSS WESTERN KANSAS IN THE AFTERNOON AND SPREAD ACROSS THE REMAINDER OF THE AREA MONDAY NIGHT. A FEW STORMS COULD BECOME STRONG TO SEVERE ACROSS CENTRAL KANSAS DEPENDING ON HOW MUCH HEATING OCCURS DURING THE DAY. RAIN CHANCES BECOME LIKELY TUESDAY AS MOISTURE CONTINUES TO BE PULLED UP FROM THE GULF AND PWAT`S SURPASS AN INCH. MEANWHILE, AN UPPER LEVEL LOW ENTERS THE WESTERN UNITED STATES TUESDAY THEN SLIDES SOUTHWARD INTO THE DESERT SOUTHWEST BY THURSDAY. THIS LOW THEN CURLS NORTHEAST INTO THE CENTRAL ROCKIES FRIDAY THEN INTO THE NORTHERN ROCKIES WEEKEND. WEAK SHORTWAVES ARE EXPECTED TO MOVE AROUND THE PERIPHERY OF THIS SYSTEM AND TOWARDS THE CENTRAL PLAINS FOR THE REMAINDER OF THE WEEK. THIS WILL ALLOW PRECIPITATION CHANCES TO CONTINUE ACROSS THE AREA WITH THE BEST CHANCE OF BENEFICIAL RAINFALL ACROSS CENTRAL AND SOUTH CENTRAL KANSAS. AS FOR TEMPERATURES, HIGHS MONDAY LOOK TO RANGE FROM THE LOWER 70S ACROSS WEST CENTRAL KANSAS WHERE THE FRONTAL BOUNDARY WILL BE LOCATED TO LOWER 80S ACROSS SOUTH CENTRAL KANSAS. HIGHS TUESDAY ARE ANTICIPATED TO BE AROUND 70 DEGREES. LOWS MONDAY NIGHT AND TUESDAY NIGHT ARE PROGGED TO RANGE FROM AROUND 50 DEGREES ACROSS FAR WESTERN KANSAS TO AROUND 60 DEGREES ACROSS CENTRAL AND SOUTH CENTRAL KANSAS. HIGHS FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S WITH LOWS RANGING FROM AROUND 50 DEGREES ACROSS FAR WESTERN KANSAS TO AROUND 60 DEGREES ACROSS CENTRAL AND SOUTH CENTRAL KANSAS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1203 AM CDT SUN MAY 3 2015 THE PERSISTENT LEE TROUGH WILL REMAIN THROUGH SUNDAY...ALTHOUGH IT WILL PUSH FARTHER EAST, WHICH WILL RESULT IN LESSER WIND ESPECIALLY FOR GCK TERMINAL. IN FACT, GCK SHOULD SEE WIND BELOW 10 KNOTS THROUGH JUST ABOUT THE ENTIRE PERIOD...OUTSIDE OF CONVECTION. SPEAKING OF CONVECTION, THERE IS A PRETTY HIGH LIKELIHOOD OF STORMS LATE TOMORROW AFTERNOON/EVENING ACROSS SOUTHWEST KANSAS, WITH THE GCK TERMINAL MOST LIKELY AFFECTED ANYTIME AFTER 23Z OR SO. && .PRELIMINARY POINT TEMPS/POPS... DDC 88 58 80 57 / 20 30 50 70 GCK 88 55 78 55 / 30 40 60 90 EHA 88 54 75 53 / 30 30 60 80 LBL 90 57 79 56 / 30 30 60 90 HYS 87 58 78 57 / 20 40 60 60 P28 86 60 81 59 / 10 10 20 40 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...UMSCHEID LONG TERM...HOVORKA_42 AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS GOODLAND KS
220 AM MDT SUN MAY 3 2015 .UPDATE... ISSUED AT 814 PM MDT SAT MAY 2 2015 BASED ON RADAR TRENDS OVER THE LAST COUPLE HOURS AND LATEST MODEL DATA...HAVE LOWERED RAINFALL CHANCES ACROSS MOST OF THE AREA EXCEPT FOR THE YUMA COUNTY AREA AND GREELEY AND WICHITA COUNTIES WHERE RAINFALL IS OR WILL BE MOVING OVER IN THE NEXT FEW HOURS. LATEST DATA INDICATES THE LIFT OVER THE NORTHWEST QUADRANT OF THE IS AT ITS BEST NOW AND WILL DECLINE RATHER QUICKLY OVER THE NEXT COUPLE OF HOURS. FURTHER SOUTH...THE TRACK OF THE 700MB SHORT WAVE TROUGH HAS BEEN PUSHED FURTHER SOUTH FOR TONIGHT...WITH THE MAJORITY OF THE LIFT REMAINING SOUTH OF THE AREA. STILL EXPECTING RAINFALL CHANCES TO END BY OR SHORTLY AFTER MIDNIGHT AS THE LIFT WITH THE SHORT WAVE TROUGH COMES TO AN END AS THE TROUGH FILLS/MOVES OUT OF THE AREA. UPDATE ISSUED AT 552 PM MDT SAT MAY 2 2015 MAIN CHANGE WAS TO INCREASE RAINFALL CHANCES FOR THE EVENING BASED ON LATEST DATA. LATEST RADAR SHOWS LINE OF STORMS AHEAD OF A 700MB SHORT WAVE TROUGH OVER EASTERN COLORADO. 700-500MB FRONTOGENESIS STRENGTHENS RAPIDLY DURING THE EARLY EVENING AND SHIFTS EAST TO THE CENTRAL PART OF THE AREA BY MID EVENING ACCOMPANYING THE 700MB SHORT WAVE TROUGH. MEANWHILE ISENTROPIC LIFT STRENGTHENS THROUGH THE FIRST HALF OF THE EVENING...WITH THE STRONGEST LIFT WEST OF HIGHWAY 25 WHILE CONDENSATION PRESSURE DEFICITS DECLINE. TOWARD MIDNIGHT THE LIFT DECLINES AND CONDENSATION PRESSURE DEFICITS INCREASE AS THE SHORT WAVE TROUGH MOVES ACROSS THE EAST HALF OF THE AREA. WITH THIS IN MIND HAVE THE HIGHEST CHANCES FOR RAINFALL DURING THE FIRST HALF OF THE EVENING MAINLY FOR LOCATIONS SOUTH OF I-70. TOWARD MIDNIGHT...AS ENVIRONMENT BECOMES LESS FAVORABLE FOR RAINFALL...HAVE RAINFALL CHANCES QUICKLY DECLINING OVER THE EAST HALF OF THE AREA. LOOKING AT THE SEVERE WEATHER POTENTIAL...STRONGEST STORMS STILL REMAIN WEST OF THE AREA WHERE THE BEST FORCING IS LOCATED. HAVE HAD SOME ISOLATED STORMS DEVELOP ALONG THE SURFACE TROUGH EXTENDING FROM SOUTHWEST TO NORTHEAST OVER THE CENTRAL PART OF THE AREA. HOWEVER THESE STORMS HAVE BEEN TOO FAR REMOVED FROM THE BETTER UPPER LEVEL FORCING TO LAST VERY LONG AND HAVE BEEN FAIRLY WEAK. AS STORMS MOVE EAST INTO THE AREA...THE LIKELIHOOD FOR SEVERE OUTFLOW WINDS INCREASES OVER THE NEXT HOUR OR SO BEFORE THE INVERSION DEVELOPS. OVERALL SEVERE STORMS ARE MOST LIKELY WEST OF HIGHWAY 25 PRIOR TO 9 PM CT OR 8 PM MT. AFTER THAT THE FORCING...SHEAR...AND INSTABILITY DECLINE. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 157 PM MDT SAT MAY 2 2015 LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW WESTERLY ZONAL FLOW IN PLACE FROM THE GREAT BASIN ACROSS THE CENTRAL ROCKIES INTO THE MISSISSIPPI VALLEY WITH EMBEDDED H5/H7 SHORTWAVE TROUGHS MOVING THROUGH THE MEAN FLOW. AT THE SURFACE LEE TROUGH HAS DEVELOPED ACROSS EASTERN COLORADO WITH A MEAN SURFACE TROUGH FROM THE NE PANHANDLE AND ALONG THE COLORADO BORDER. THUNDERSTORM ACTIVITY HAS ALREADY DEVELOPED ALONG THE CHEYENNE RIDGE AND HIGHER TERRAIN IN COLORADO. THIS AFTERNOON-TONIGHT...RAP ANALYSIS (WHICH IS IN LINE WITH EARLIER NAM) SHOWS 2000 J/KG OF SB CAPE IN PLACE ALONG AND AHEAD OF THE SURFACE TROUGH...CENTERED OVER OUR CWA. CINH APPEARS TO BE WEAKENING...HOWEVER ONLY SOME SHALLOW CU HAVE FORMED SO FAR THIS AFTERNOON. AS MID LEVEL VORTICITY ROTATES FROM THE CENTRAL ROCKIES INTO EASTERN COLORADO I WOULD EXPECT DEVELOPMENT TO SPREAD EAST WHICH IS IN LINE WITH SYNOPTIC SCALE GUIDANCE. HRRR/RAP BOTH INDICATE ISOLATED ACTIVITY DEVELOPING ALONG AND EAST OF THE SURFACE TROUGH OVER OUR CWA WITH ADDITIONAL ACTIVITY SPREADING IN FROM THE WEST. BULK SHEER/HELICITY ARE NOT VERY IMPRESSIVE AT THIS POINT WHERE BETTER INSTABILITY IS IN PLACE (WEST). MOISTURE PROFILES ARE NOT PARTICULARLY IMPRESSIVE...AND THIS COULD LIMIT COVERAGE TO ISOLATE/SCATTERED. BETTER PRECIP SIGNAL AND INSTABILITY ARE SHOW IN IN THE LOWER SHEER ENVIRONMENT...WHERE PULSE TYPE THUNDERSTORMS WOULD BE MORE LIKELY. STEEP MID LEVEL LAPSE RATES AND MODERATE INSTABILITY COULD SUPPORT STRONGER UPDRAFTS/CORES...WITH LARGE HAIL/SEVERE WINDS POSSIBLE. DCAPE VALUES 1000-1500 J/KG AND IN HIGHER TD DEPRESSIONS (MAINLY WEST) DO RAISE A CONCERN FOR INCREASED MICROBURST POTENTIAL WITH SOME OF THESE STORMS. IF ANY OF THIS ACTIVITY WAS TO MOVE INTO THE EASTERN CWA IT COULD BECOME MORE ORGANIZED WITH INCREASING SPEED SHEER (35KT BULK EFFECTIVE SHEER AROUND 00Z). AS THE SUN SETS AND WE LOOSE DAYTIME HEATING ANY LINGERING ACTIVITY SHOULD QUICKLY WEAKEN AS THERE IS ELEVATED CAPE LATE AND ONLY A WEAK LLJ IN PLACE OVERNIGHT. SUNDAY...ANOTHER VERY WARM DAY IS EXPECTED AS SURFACE TROUGH DEEPENS A LITTLE OVER THE CWA AND WAA INCREASES OVER THE CWA. THIS IS IN RESPONSE TO A STRONGER SHORTWAVE TROUGH MOVING INTO THE NORTHERN PLAINS AND A COLD FRONT DROPPING SOUTH INTO NORTHERN NEBRASKA. HIGHS SHOULD BE SIMILAR TO TODAY WITH MOST IN THE 80S...AND A FEW LOCATIONS APPROACHING 90 (MAINLY MCCOOK/HILL CITY). SURFACE TROUGH WILL SHIFT JUST A LITTLE BIT EAST AND LOW LEVEL MOISTURE RETURN COULD BRING HIGHER TD VALUES INTO NORTH CENTRAL KS. NAM MAY BE A LITTLE HIGH...BUT EITHER WAY THIS BETTER BL MOISTURE WILL SUPPORT HIGHER CAPE VALUES IN THE AFTERNOON IN THE 2000-2500 J/KG RANGE. SHEER MAY ALSO BE A LITTLE BIT BETTER WHERE GOOD INSTABILITY IS IN PLACE THAN TODAY...SO THERE MAY BE A BIGGER THREAT FOR MORE ORGANIZE THUNDERSTORM DEVELOPMENT IF ANYTHING IS TO DEVELOP IN THE AFTERNOON. THUNDERSTORM ACTIVITY IS SHOWN TO INITIATE PRIMARILY ALONG SURFACE TROUGH IN THE AFTERNOON. HOWEVER WITH DRIER MOISTURE PROFILES AGAIN IN PLACE COVERAGE COULD BE LIMITED AT LEAST UNTIL LATER WHEN BETTER LARGE SCALE FORCING/DEEPER MOISTURE MOVINGS IN TO THE REGION FROM THE NORTHWEST. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 219 AM MDT SUN MAY 3 2015 THERE WILL BE CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS THE TRI STATE AREA ON WEDNESDAY AS AN UPPER LEVEL SHORTWAVE TROUGH MOVES ACROSS THE AREA. THE NEGATIVELY TILTED FEATURE WILL BRING SOME STEEPER LAPSE RATES ALOFT AND AREA CAPE VALUES AROUND 1000 J/KG WEDNESDAY AFTERNOON BASED ON GFS MODEL SOUNDINGS...HOWEVER WEAK SPEED AND DIRECTIONAL SHEAR DOES NOT SUPPORT THE DEVELOPMENT OF STRONGER STORMS. WITH SOUTHERLY ADVECTION THROUGH MOST OF THE PROFILE WEDNESDAY MORNING...DEEP SATURATION IS LIKELY WITH PRECIPITABLE WATER VALUES BETWEEN 0.80 AND 1.00 INCHES. THEREFORE...RAIN SHOWERS AND GENERAL WIDESPREAD THUNDERSTORMS ARE EXPECTED WEDNESDAY AFTERNOON AND EVENING WITH LOCALLY HEAVY RAINFALL POSSIBLE. THE UPPER LEVEL TROUGH CONTINUES TO DEEPEN OVERNIGHT WEDNESDAY AND BECOMES SEPARATED FROM THE UPPER LEVEL FLOW THURSDAY OVER THE WESTERN CONUS. MODELS DIFFER SLIGHTLY ON THE PROGRESSION OF THE PATTERN...BUT THE TIMING IS GENERALLY IN AGREEMENT FOR THE FEATURE TO CONTINUE TO SPIN SLOWLY EASTWARD FOR THURSDAY THROUGH THE BEGINNING OF NEXT WEEKEND...THUS AFFECTING THE TRI STATE AREA. BECAUSE OF THE POSITION OF THE SLOW MOVING UPPER LEVEL SYSTEM...THERE WILL BE CHANCES FOR SHOWERS AND THUNDERSTORMS FOR THE ENTIRETY OF THE EXTENDED FORECAST. SURFACE TEMPERATURES THROUGH THE PERIOD WILL REMAIN STEADY DUE TO THE RELATIVELY UNCHANGING UPPER FLOW...WITH HIGHS IN THE MID TO UPPER 70S AND LOWS IN THE UPPER 40S TO LOWER 50S. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1055 PM MDT SAT MAY 2 2015 VFR CONDITIONS FORECAST FOR THE 6Z TAFS. STORM ACTIVITY HAS COME TO AN END ACROSS THE TRI-STATE AREA. LIGHT WINDS WILL CONTINUE THROUGH THE REST OF THE NIGHT AND SUNDAY. DURING THE DAY A SURFACE TROUGH WILL MOVE THROUGH THE AREA CAUSING THE WINDS TO TURN CLOCKWISE THROUGH THE DAY...BECOMING NORTHEAST TO EAST BY EARLY EVENING. DURING THE EVENING STORM COVERAGE WILL INCREASE. DID NOT PLACE A MENTION IN THE TAFS AT THIS TIME SINCE THERE IS A POSSIBILITY THE STORMS WILL NOT MOVE NEAR THE SITES UNTIL AFTER 6Z...WHEN CHANCES FOR STORMS WILL INCREASE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...DR LONG TERM...MK AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 PM MDT SAT MAY 2 2015 .UPDATE... ISSUED AT 814 PM MDT SAT MAY 2 2015 BASED ON RADAR TRENDS OVER THE LAST COUPLE HOURS AND LATEST MODEL DATA...HAVE LOWERED RAINFALL CHANCES ACROSS MOST OF THE AREA EXCEPT FOR THE YUMA COUNTY AREA AND GREELEY AND WICHITA COUNTIES WHERE RAINFALL IS OR WILL BE MOVING OVER IN THE NEXT FEW HOURS. LATEST DATA INDICATES THE LIFT OVER THE NORTHWEST QUADRANT OF THE IS AT ITS BEST NOW AND WILL DECLINE RATHER QUICKLY OVER THE NEXT COUPLE OF HOURS. FURTHER SOUTH...THE TRACK OF THE 700MB SHORT WAVE TROUGH HAS BEEN PUSHED FURTHER SOUTH FOR TONIGHT...WITH THE MAJORITY OF THE LIFT REMAINING SOUTH OF THE AREA. STILL EXPECTING RAINFALL CHANCES TO END BY OR SHORTLY AFTER MIDNIGHT AS THE LIFT WITH THE SHORT WAVE TROUGH COMES TO AN END AS THE TROUGH FILLS/MOVES OUT OF THE AREA. UPDATE ISSUED AT 552 PM MDT SAT MAY 2 2015 MAIN CHANGE WAS TO INCREASE RAINFALL CHANCES FOR THE EVENING BASED ON LATEST DATA. LATEST RADAR SHOWS LINE OF STORMS AHEAD OF A 700MB SHORT WAVE TROUGH OVER EASTERN COLORADO. 700-500MB FRONTOGENESIS STRENGTHENS RAPIDLY DURING THE EARLY EVENING AND SHIFTS EAST TO THE CENTRAL PART OF THE AREA BY MID EVENING ACCOMPANYING THE 700MB SHORT WAVE TROUGH. MEANWHILE ISENTROPIC LIFT STRENGTHENS THROUGH THE FIRST HALF OF THE EVENING...WITH THE STRONGEST LIFT WEST OF HIGHWAY 25 WHILE CONDENSATION PRESSURE DEFICITS DECLINE. TOWARD MIDNIGHT THE LIFT DECLINES AND CONDENSATION PRESSURE DEFICITS INCREASE AS THE SHORT WAVE TROUGH MOVES ACROSS THE EAST HALF OF THE AREA. WITH THIS IN MIND HAVE THE HIGHEST CHANCES FOR RAINFALL DURING THE FIRST HALF OF THE EVENING MAINLY FOR LOCATIONS SOUTH OF I-70. TOWARD MIDNIGHT...AS ENVIRONMENT BECOMES LESS FAVORABLE FOR RAINFALL...HAVE RAINFALL CHANCES QUICKLY DECLINING OVER THE EAST HALF OF THE AREA. LOOKING AT THE SEVERE WEATHER POTENTIAL...STRONGEST STORMS STILL REMAIN WEST OF THE AREA WHERE THE BEST FORCING IS LOCATED. HAVE HAD SOME ISOLATED STORMS DEVELOP ALONG THE SURFACE TROUGH EXTENDING FROM SOUTHWEST TO NORTHEAST OVER THE CENTRAL PART OF THE AREA. HOWEVER THESE STORMS HAVE BEEN TOO FAR REMOVED FROM THE BETTER UPPER LEVEL FORCING TO LAST VERY LONG AND HAVE BEEN FAIRLY WEAK. AS STORMS MOVE EAST INTO THE AREA...THE LIKELIHOOD FOR SEVERE OUTFLOW WINDS INCREASES OVER THE NEXT HOUR OR SO BEFORE THE INVERSION DEVELOPS. OVERALL SEVERE STORMS ARE MOST LIKELY WEST OF HIGHWAY 25 PRIOR TO 9 PM CT OR 8 PM MT. AFTER THAT THE FORCING...SHEAR...AND INSTABILITY DECLINE. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 157 PM MDT SAT MAY 2 2015 LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW WESTERLY ZONAL FLOW IN PLACE FROM THE GREAT BASIN ACROSS THE CENTRAL ROCKIES INTO THE MISSISSIPPI VALLEY WITH EMBEDDED H5/H7 SHORTWAVE TROUGHS MOVING THROUGH THE MEAN FLOW. AT THE SURFACE LEE TROUGH HAS DEVELOPED ACROSS EASTERN COLORADO WITH A MEAN SURFACE TROUGH FROM THE NE PANHANDLE AND ALONG THE COLORADO BORDER. THUNDERSTORM ACTIVITY HAS ALREADY DEVELOPED ALONG THE CHEYENNE RIDGE AND HIGHER TERRAIN IN COLORADO. THIS AFTERNOON-TONIGHT...RAP ANALYSIS (WHICH IS IN LINE WITH EARLIER NAM) SHOWS 2000 J/KG OF SB CAPE IN PLACE ALONG AND AHEAD OF THE SURFACE TROUGH...CENTERED OVER OUR CWA. CINH APPEARS TO BE WEAKENING...HOWEVER ONLY SOME SHALLOW CU HAVE FORMED SO FAR THIS AFTERNOON. AS MID LEVEL VORTICITY ROTATES FROM THE CENTRAL ROCKIES INTO EASTERN COLORADO I WOULD EXPECT DEVELOPMENT TO SPREAD EAST WHICH IS IN LINE WITH SYNOPTIC SCALE GUIDANCE. HRRR/RAP BOTH INDICATE ISOLATED ACTIVITY DEVELOPING ALONG AND EAST OF THE SURFACE TROUGH OVER OUR CWA WITH ADDITIONAL ACTIVITY SPREADING IN FROM THE WEST. BULK SHEER/HELICITY ARE NOT VERY IMPRESSIVE AT THIS POINT WHERE BETTER INSTABILITY IS IN PLACE (WEST). MOISTURE PROFILES ARE NOT PARTICULARLY IMPRESSIVE...AND THIS COULD LIMIT COVERAGE TO ISOLATE/SCATTERED. BETTER PRECIP SIGNAL AND INSTABILITY ARE SHOW IN IN THE LOWER SHEER ENVIRONMENT...WHERE PULSE TYPE THUNDERSTORMS WOULD BE MORE LIKELY. STEEP MID LEVEL LAPSE RATES AND MODERATE INSTABILITY COULD SUPPORT STRONGER UPDRAFTS/CORES...WITH LARGE HAIL/SEVERE WINDS POSSIBLE. DCAPE VALUES 1000-1500 J/KG AND IN HIGHER TD DEPRESSIONS (MAINLY WEST) DO RAISE A CONCERN FOR INCREASED MICROBURST POTENTIAL WITH SOME OF THESE STORMS. IF ANY OF THIS ACTIVITY WAS TO MOVE INTO THE EASTERN CWA IT COULD BECOME MORE ORGANIZED WITH INCREASING SPEED SHEER (35KT BULK EFFECTIVE SHEER AROUND 00Z). AS THE SUN SETS AND WE LOOSE DAYTIME HEATING ANY LINGERING ACTIVITY SHOULD QUICKLY WEAKEN AS THERE IS ELEVATED CAPE LATE AND ONLY A WEAK LLJ IN PLACE OVERNIGHT. SUNDAY...ANOTHER VERY WARM DAY IS EXPECTED AS SURFACE TROUGH DEEPENS A LITTLE OVER THE CWA AND WAA INCREASES OVER THE CWA. THIS IS IN RESPONSE TO A STRONGER SHORTWAVE TROUGH MOVING INTO THE NORTHERN PLAINS AND A COLD FRONT DROPPING SOUTH INTO NORTHERN NEBRASKA. HIGHS SHOULD BE SIMILAR TO TODAY WITH MOST IN THE 80S...AND A FEW LOCATIONS APPROACHING 90 (MAINLY MCCOOK/HILL CITY). SURFACE TROUGH WILL SHIFT JUST A LITTLE BIT EAST AND LOW LEVEL MOISTURE RETURN COULD BRING HIGHER TD VALUES INTO NORTH CENTRAL KS. NAM MAY BE A LITTLE HIGH...BUT EITHER WAY THIS BETTER BL MOISTURE WILL SUPPORT HIGHER CAPE VALUES IN THE AFTERNOON IN THE 2000-2500 J/KG RANGE. SHEER MAY ALSO BE A LITTLE BIT BETTER WHERE GOOD INSTABILITY IS IN PLACE THAN TODAY...SO THERE MAY BE A BIGGER THREAT FOR MORE ORGANIZE THUNDERSTORM DEVELOPMENT IF ANYTHING IS TO DEVELOP IN THE AFTERNOON. THUNDERSTORM ACTIVITY IS SHOWN TO INITIATE PRIMARILY ALONG SURFACE TROUGH IN THE AFTERNOON. HOWEVER WITH DRIER MOISTURE PROFILES AGAIN IN PLACE COVERAGE COULD BE LIMITED AT LEAST UNTIL LATER WHEN BETTER LARGE SCALE FORCING/DEEPER MOISTURE MOVINGS IN TO THE REGION FROM THE NORTHWEST. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 233 PM MDT SAT MAY 2 2015 UPPER LEVEL FLOW WILL BE SOUTHWEST FROM SUNDAY NIGHT THROUGH TUESDAY AHEAD OF A LOW MOVING EAST FROM THE DESERT SOUTHWEST INTO THE CENTRAL AND SOUTHERN ROCKIES. A SURFACE TROUGH NEAR NORTHWEST KANSAS WILL MOVE EAST MONDAY. HIGH PRESSURE WILL BUILD INTO NORTHWEST KANSAS MONDAY NIGHT AND TUESDAY. AN AREA OF LOW PRESSURE WILL MOVE INTO COLORADO TUESDAY. A SHORTWAVE SHOULD AFFECT THE FA SUNDAY EVENING AND INITIATE STORMS NEAR THE SURFACE TROUGH OVER NORTHEAST COLORADO INTO SOUTHWEST NEBRASKA. PLAN TO USE HIGH CHANCE POPS IN THAT AREA WITH LOWER CHANCE POPS ELSEWHERE ACROSS THE FA. PLAN TO KEEP HIGHER CHANCE POPS ACROSS THE NORTHERN FA AS STORMS DRIFT NORTHEAST INTO THE FA OVERNIGHT. THERE SHOULD BE A LULL MONDAY MORNING BEHIND THE EXITING WAVE. POPS WILL INCREASE TO HIGH CHANCE MONDAY AFTERNOON AND EVENING AS THE NEXT SHORTWAVE COMES THROUGH. MOISTURE AND DYNAMICS LOOK GOOD FOR MONDAY NIGHT SO WILL CONTINUE HIGH CHANCE AND LIKELY POPS. GOOD DYNAMICS AND MOISTURE CONTINUE TO STREAM ACROSS THE FA TUESDAY AS THE MAIN TROUGH MOVES INTO THE AREA. PRECIPITABLE WATER VALUES ACROSS THE FA FOR TUESDAY RANGE FROM 1.0 TO 1.2 INCHES. PLAN TO CONTINUE LIKELY AND DEFINITE POPS. MIN TEMPERATURES THROUGH MONDAY NIGHT SHOULD COOL INTO THE MID 40S IN EASTERN COLORADO TO THE MID 50S IN THE EASTERN FA. MAX TEMPERATURES MONDAY SHOULD RANGE FROM THE LOWER 60S IN EASTERN COLORADO TO THE LOWER 70S IN THE EASTERN FA. IN THE EXTENDED...(TUESDAY NIGHT THROUGH SATURDAY)...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE CENTRAL PLAINS TUESDAY NIGHT AND WEDNESDAY AND THEN LIFT OUT OF THE AREA WEDNEDAY NIGHT. GOOD DYNAMICS AND MOISTURE SUPPORT HIGH POPS THROUGH WEDNESDAY. POPS WILL DECREASE TO CHANCE THURSDAY AND FRIDAY BEHIND THE EXITING TROUGH WITH A COUPLE OF SHORTWAVES IN SOUTHWEST FLOW PRODUCING STORMS. POPS WILL INCREASE AGAIN SATURDAY AS THE NEXT UPPER LEVEL TROUGH BEGINS IMPACTING THE CENTRAL PLAINS. MIN TEMPERATURES SHOULD RANGE FROM 45 TO 55 THROUGH FRIDAY NIGHT WITH COOLER READINGS IN EASTERN COLORADO. MAX TEMPERATURES WILL GENERALLY WARM TO THE 70S EACH DAY WITH SOME UPPER 60S POSSIBLE IN EASTERN COLORADO AND NEAR 80 IN THE EASTERN FA. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1055 PM MDT SAT MAY 2 2015 VFR CONDITIONS FORECAST FOR THE 6Z TAFS. STORM ACTIVITY HAS COME TO AN END ACROSS THE TRI-STATE AREA. LIGHT WINDS WILL CONTINUE THROUGH THE REST OF THE NIGHT AND SUNDAY. DURING THE DAY A SURFACE TROUGH WILL MOVE THROUGH THE AREA CAUSING THE WINDS TO TURN CLOCKWISE THROUGH THE DAY...BECOMING NORTHEAST TO EAST BY EARLY EVENING. DURING THE EVENING STORM COVERAGE WILL INCREASE. DID NOT PLACE A MENTION IN THE TAFS AT THIS TIME SINCE THERE IS A POSSIBILITY THE STORMS WILL NOT MOVE NEAR THE SITES UNTIL AFTER 6Z...WHEN CHANCES FOR STORMS WILL INCREASE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JTL SHORT TERM...DR LONG TERM...FS AVIATION...JTL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1129 PM CDT Sat May 2 2015 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Sunday) Issued at 404 PM CDT SAT MAY 2 2015 19Z water vapor imagery shows a shortwave moving across IA while 500MB profiler data suggests a more subtle wave has passed through eastern KS. Meanwhile a weak mid level ridge has propagated east and is centered over the TX big bend region with the mean westerlies remain north along the Canadian boarder. At the surface, high pressure over the southeast U.S. and low pressure in the northern plains has favored continued moisture advection with southerly winds bringing mid 50s dewpoints into the central plains. For tonight and Sunday, large scale forcing continues to be absent from the pattern. However models hint at the possibility for sporadic shower activity as early as this evening. The HRRR and RAP are the most optimistic in generating the shower activity. It appears the evening QPF is driven by warm air advection and isentropic upglide around 700MB. However RAP soundings suggest moisture will be rather limited in this layer. Because of this and the general subsidence behind the subtle wave, am not convinced showers will redevelop across central KS this evening. There are also signs that another subtle wave could come out of the CO Rockies late tonight and Sunday morning with some elevated light shower activity. There is a more organized signal in the isentropic surfaces of a shallow layer of lift Sunday morning. With bases at 10 KFT and little if any instability above this layer, am not sure any precip would amount to much and it end up being mainly virga. So have maintained a dry forecast for now, but there could be some light hit or miss precip with not much impact. Thanks for the collaboration EAX and ICT. Southerly winds and increased low level moisture should help keep lows tonight around 60 degrees. Increasing clouds from the west should also help keep overnight lows mild. With continued southerly winds, models continue the warming trend at 850MB with good mixing. Therefore have maintained highs in the lower and mid 80s. However if there is elevated shower activity, the forecast may be to warm for areas that remain cloudy. .LONG TERM...(Sunday Night through Saturday) Issued at 404 PM CDT SAT MAY 2 2015 Several opportunities for precipitation remain present through the forecast, with challenges on where and when the higher chances will be being the main challenge. The main trend in the nearer periods is the trend for a farther north settling of the cold front as it enters the area. Getting the front much past the northwest counties could be difficult with little/no additional frontogenesis from convection through Sunday afternoon along it and west to southwest flow over it. Have continued to taper precip chances, especially in the south into Monday night. There continues to be at least minor potential for severe weather and perhaps training storms near the boundary. NAM continues to look overdone with low level moisture and thus CAPE, but values near 2000 J/kg seem possible along the front with flow aloft nearly parallel to the boundary with slow cell motions and PWs near 1.5", more likely late Monday into Monday night. The front/effective front remains on track to mix back north Tuesday with some drier air moving in through the day, but attention then turns to the southwest as an upper wave remains on track to push slowly northeast through the Central Plains Tuesday night through Wednesday night. Models are fairly consistent with better upper forcing to the northwest and southeast, but also with widespread convection developing to the south-southwest and translating through late Tuesday night into Wednesday. Beyond Wednesday night, there continues to be indications of a weak boundary near to just west of the area with continued moisture availability into the area into Saturday. && .AVIATION...(For the 06Z TAFs through 06Z Sunday Night) Issued at 1126 PM CDT SAT MAY 2 2015 VFR conditions expected through most of the taf period. There is a slight chance for showers and storms towards the end of the period, but confidence is low on timing at this point. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Wolters LONG TERM...65 AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 AM EDT SUN MAY 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 505 AM EDT SUN MAY 3 2015 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION. UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50. A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR 10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND 1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS INTO THE MID TO UPPER 70S OVER THE WEST HALF. THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING. LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K- 10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER SOUTH. EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY 06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 AM EDT SUN MAY 3 2015 ABOVE AVERAGE TEMPS WITH GENERALLY DRY CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA THROUGH TUESDAY BEFORE OFF AND ON CHANCES OF SHOWERS AND THUNDERSTORMS CLOSE OUT THE WEEK. MONDAY AND TUESDAY...A SPLIT UPPER JET PATTERN WILL BE WELL IN PLACE TO BEGIN THE PERIOD...WITH A VERY BROAD MID-LEVEL TROUGH ACROSS THE UPPER MS VALLEY AND UPPER GREAT LAKES. THE COLD FRONT AND ASSOCIATED CONVECTION EXPECTED TO INFLUENCE THE CWA THIS AFTERNOON AND TONIGHT WILL CLEAR THE CWA BY 12Z MONDAY. WITH SFC HIGH PRESSURE SHIFTING ACROSS THE CWA AND A MID-LEVEL RIDGE BUILDING ACROSS THE NORTHERN PLAINS...DRY CONDITIONS ARE EXPECTED MONDAY THROUGH TUESDAY. TEMPS WILL BE COOLER THAN TODAY FOR BOTH MONDAY AND TUESDAY AS 850 HPA TEMPS FALL TO 3-7C. WITH A WNW WIND MON...TEMPS WILL BE CHILLY ACROSS PORTIONS OF THE LAKE SUPERIOR SHORELINE...ESPECIALLY EAST OF MARQUETTE. SOME HINTS AS LINGERING LOW-LEVEL MOISTURE OVER EASTERN LAKE SUPERIOR MAY ALSO RESULT IN SOME FOG ALONG THE SHORELINE THROUGH MOST OF MONDAY. TUESDAY NIGHT AND WEDNESDAY...A BROAD SFC LOW FORMING UNDER THE SOUTHERN UPPER JET AND A MID-LEVEL TROUGH OVER THE SW STATES WILL BEGIN TO LIFT INTO THE CENTRAL PLAINS BY THIS TIME. MEANWHILE...THE MID-LEVEL RIDGE ACROSS THE PLAINS AND MS VALLEY WILL CONTINUE TO BUILD WHILE DRIFTING EASTWARD. LOW-LEVEL WAA/ISENTROPIC LIFT WELL AHEAD OF THIS LOW IS EXPECTED ACROSS WI AND THE WEST AND CENTRAL CWA TUESDAY NIGHT INTO WEDNESDAY...AND SHOULD BE ENOUGH TO GENERATE LIGHT RAIN ALOFT. HOW MUCH REACHES THE GROUND REMAINS IN QUESTION AS THE LOW-LEVELS WILL BE QUITE DRY TUESDAY. BECAUSE OF THIS...ALL MODEL SOLUTIONS SHOW A RAPID DETERIORATION OF THE PRECIP AS IT MOVES OVER UPPER MI. HAVE OPTED TO KEEP ONLY LOW CHANCE POPS ALONG THE WI BORDER TUESDAY NIGHT...AND ACROSS MUCH OF WESTERN AND CENTRAL UPPER MI ON WEDNESDAY. THURSDAY THROUGH SATURDAY...THE SFC LOW OVER THE PLAINS WILL CONTINUE TO MEANDER TO THE NE AS THE ASSOCIATED MID-LEVEL WAVE ATTEMPTS TO ROUND THE RIDGE. WITH MINIMAL FORCING...MUCH OF THE AREA SHOULD REMAIN DRY WED NIGHT INTO THU MORNING. BY THE AFTERNOON...FORCING FROM THE APPROACHING MID-LEVEL SHORTWAVE WILL BE ENOUGH TO INDUCE SCATTERED SHOWERS AND POSSIBLY SOME THUNDERSTORMS ACROSS THE WEST HALF OF THE CWA. WITH THE WAVE AND SFC LOW LIFTING ACROSS THE ARROWHEAD OF MN AND NORTH OF LAKE SUPERIOR...SCATTERED SHOWERS AND STORMS ARE EXPECTED INTO FRIDAY MORNING. COVERAGE MAY INCREASE FRIDAY AFTERNOON AS THE SFC COLD FRONT BEGINS TO MOVE IN FROM THE WEST. OVERALL...DO NOT SEE ANY REASON TO GO WITH ANYTHING HIGHER THAN HIGH-END CHANCE POPS GIVEN THE OVERALL SCATTERED NATURE OF EXPECTED PRECIP. BY SATURDAY...THE SFC COLD FRONT WILL CLEAR THE AREA AS IT BEGINS TO STALL/WASH OUT OVER WI. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 125 AM EDT SUN MAY 3 2015 EXPECT VFR CONDITIONS THRU THIS MRNG AT ALL THE TAF SITES WITH RELATIVELY DRY AIRMASS ASSOCIATED WITH RETREATING HI PRES DOMINATING. DURING THE AFTN...THE INTERACTION BTWN AN APRCHG DISTURBANCE/COLD FNT...INCRSG LLVL ABSOLUTE MSTR IN A GUSTY SW FLOW AHEAD OF THE FNT AND DAYTIME HEATING/DESTABILIZATION WL RESULT IN SOME SHRA AND TS. THERE IS STILL SOME UNCERTAINTY ON THE DEGREE OF LLVL MOISTENING/DESTABILIZATION...BUT DID INCLUDE A MENTION OF SOME TS AT SAW...WHICH IS MORE LIKELY TO SEE SUFFICIENT MOISTENING. MVFR CONDITIONS ARE LIKELY TO ACCOMPANY THE STRONGER SHRA/TS. ANY STRONGER TS COULD ALSO PRODUCE VERY GUSTY WINDS. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 505 AM EDT SUN MAY 3 2015 OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD. LOW PRESSURE OVER NW ONTARIO WILL LIFT NORTHEAST TO HUDSON BAY...DRAGGING A COLD FRONT ACROSS LAKE SUPERIOR LATE THIS AFTERNOON AND EVENING ALONG WITH A CHANCE OF THUNDERSTORMS...AND PATCHY TO AREAS OF FOG. LOOK FOR HIGH PRESSURE ACROSS NORTH DAKOTA TONIGHT TO BUILD ACROSS THE UPPER GREAT LAKES MONDAY...WITH DRIER AIR LIMITING ANY LINGERING FOG ACROSS LAKE SUPERIOR. THE HIGH WILL SLOWLY EXIT ACROSS THE LOWER GREAT LAKES WEDNESDAY NIGHT...IN RESPONSE TO A LOW NEARING FROM THE N AND CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY. THE CHANCE OF THUNDERSTORMS WILL ALSO RETURN WEDNESDAY AFTERNOON THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KLUBER AVIATION...KC MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
1216 AM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 940 PM CDT SAT MAY 2 2015 THE DECAYING LINE OF SHOWERS AND THUNDERSTORMS CONTINUED TO DIMINISH AS IT MOVES EASTWARD INTO THE CWA DURING THE EVENING. SOME GUSTY WINDS REMAINED ACROSS AREAS WEST OF THE BRAINERD LAKES REGION...ALTHOUGH WIND SPEED VALUES HAVE DECREASED CONSIDERABLY. COULD STILL BE SOME GUSTY WINDS...MAINLY ACROSS THE BRAINERD LAKES AND LEECH LAKE AREAS DURING THE REMAINDER OF THE EVENING. OVERALL...THINK THINGS WILL QUIET DOWN FURTHER AS THE NIGHT WEARS ON...PER HRRR AND RAP SIMULATED REFLECTIVITY AS WELL AS THE 4KM NMM WRF. WILL CONTINUE ISOLATED TO SCATTERED MENTION FOR MUCH OF THE AREA AS THE NIGHT WEARS ON. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 324 PM CDT SAT MAY 2 2015 A SFC LOW WAS MOVING INTO NW ONTARIO AT 19Z WITH A TRAILING COLD FRONT SWWD INTO WESTERN ND. A SFC TROF WAS ALSO FOUND IN CENTRAL ND. THUNDERSTORMS WERE FIRING AHEAD OF THIS TROF IN THE VCNTY OF EMBEDDED PIECES OF ENERGY IN FAST ZONAL FLOW ALOFT. AN AREA OF SFC FGEN WAS ALSO CO-LOCATED WITH THE STORMS. EXPECT THIS LINE OF STORMS TO REACH NW MN BY 21Z. THE STORMS WILL CONTINUE TO MOVE EWD AND REACH THE NW CORNER OF KOOCHICHING COUNTY BY 01Z. HOWEVER...IT IS AT THIS POINT IN TIME WHEN THE STORMS BEGIN TO ENCOUNTER DRIER AIR THAT HAS BEEN CAMPED OUT OVER THE FORECAST AREA. LATEST SHORT TERM HIRES MODELS INCLUDING THE HRRR AND RAP SHOW THIS TREND AS WELL. AS THIS INITIAL ROUND OF STORMS DISSOLVES...THE NEXT ROUND WILL BEGIN TO DEVELOP OVER THE WESTERN HALF OF THE AREA AROUND 06Z AS THE SFC FRONT MAKES PROGRESS EWD INTO THE REGION. A LOW LEVEL INVERSION SEEN ON AREA FORECAST SOUNDINGS INDICATE THAT THESE STORMS WILL BE ELEVATED IN NATURE. ON SUNDAY...THE FRONT WILL PROGRESS SLOWLY EWD THROUGH THE DAY. SOME WEAK THUNDERSTORMS WILL BE AROUND IN THE MORNING AS A THERMAL RIDGE AXIS IS OVER THE REGION AND INSTABILITY IS WEAK. BY AFTERNOON...THE FRONT PUSHES INTO NW WI WITH MAX HEATING...STORMS WILL BECOME A BIT MORE VIGOROUS...AND BORDER ON SEVERE. SBCAPE INCREASES TO NEAR 3000 J/KG AND LI/S TO -8C PER FORECAST SOUNDINGS. SHOULD SEE SOME STORMS NEAR SEVERE WITH LARGE HAIL AND BRIEF HEAVY RAIN AS PWATS ARE 1 TO 1.25 INCHES. MODELS COME INTO AGREEMENT WITH THIS SOLUTION AND HAVE ROBUST QPF BY 00Z MONDAY. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 324 PM CDT SAT MAY 2 2015 SUNDAY EVENING THE COLD FRONT MOVES SOUTHEAST AWAY FROM THE AREA...AND WHILE I HAVE MAINTAINED SOME POPS FOR THE EVENING HOURS...EXPECT THEY WILL ONLY BE ONGOING AT THE VERY BEGINNING OF THE PERIOD AND EXIT QUICKLY DURING THE EVENING. A COOLER AND DRIER AIRMASS MOVES INTO THE AREA AFTER MIDNIGHT AND WILL LINGER THROUGH MONDAY AND MONDAY NIGHT. LOWS SUNDAY NIGHT AND MONDAY NIGHT TO FALL INTO THE MID 30S TO MID 40S FOR MUCH OF THE AREA...WITH HIGHS MONDAY BACK IN THE 60S TO AROUND 70. THE UPPER LEVEL PATTERN IS EXPECTED TO SHIFT TO A LONGWAVE TROUGH OVER THE WEST COAST AND ROCKIES...WITH WEAK RIDGING TO ZONAL FLOW OVER THE EASTERN CONUS. THIS TROUGHINESS TO OUR WEST IS GOING TO SENT A STRONG...SLOW MOVING UPPER LEVEL LOW SHORTWAVE ACROSS THE UPPER MIDWEST TUESDAY THROUGH FRIDAY...WITH SOME FAIRLY HIGH CHANCES FOR PRECIPITATION DURING THE PERIOD. TEMPERATURES WILL ALSO BE ABOVE NORMAL WITH HIGHS IN THE 70S EVEN WITH INCREASED CLOUD COVER AND PRECIPITATION. THIS SYSTEM TO MOVE OFF TO THE NORTHEAST BY SATURDAY...BUT THE UPPER LEVEL PATTERN OF A TROUGH OUT WEST REMAINS WITH WARM AIR STILL BEING FUNNELED IN OUR DIRECTION AND SOME LINGERING PRECIPITATION CHANCES INTO THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1212 AM CDT SUN MAY 3 2015 A COLD FRONT WILL MOVE EASTWARD ACROSS THE NORTHLAND ON SUNDAY. ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TO BE FOUND ACROSS THE AREA OVERNIGHT...AS INCREASINGLY UNSTABLE AIR DEVELOPS ACROSS THE REGION INTO SUNDAY. THE COLD FRONT SHOULD REACH A KBRD TO KCDD LINE BY 15Z SUNDAY...AND KSTC TO NEAR KDLH LINE BY 18Z. THE FRONT WILL BE THE CATALYST FOR STRONG THUNDERSTORM DEVELOPMENT ON SUNDAY... WITH STORMS EXPECTED TO FIRE UP FROM EAST CENTRAL MINNESOTA INTO KDLH AND THE NORTH SHORE BY MIDDAY. THE BEST CHANCE FOR STORMS WILL BE IN WISCONSIN...ESPECIALLY FOR KHYR AND AREAS TO THE SOUTH AND EAST. SOME VSBY AND CIG RESTRICTIONS TO MVFR WILL BE POSSIBLE IN AND AROUND THE THUNDERSTORMS BUT OVERALL IT SHOULD BE VFR DUE TO DRY AIR IN THE LOWER LEVELS OF THE ATMOSPHERE. CONDITIONS WILL THEN IMPROVE FROM NW TO SE AS THE DAY WEARS ON AND INTO THE EVENING WITH SKIES CLEARING AND GUSTY WINDS DEVELOPING FOR A TIME. && .PRELIMINARY POINT TEMPS/POPS... DLH 44 67 40 68 / 0 0 0 0 INL 38 66 38 74 / 0 0 0 0 BRD 44 70 41 70 / 0 0 0 10 HYR 44 70 40 69 / 20 0 0 10 ASX 44 67 37 69 / 10 0 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ UPDATE...DAP SHORT TERM...GSF LONG TERM...LE AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
341 AM CDT Sun May 3 2015 .SHORT TERM: (Today and Tonight) Issued at 325 AM CDT Sun May 3 2015 There is quite a bit of cloud cover early this morning across the region courtesy of two weak short waves in the westerly flow aloft. The first of these currently centered from northern IL into southeast MO has been generating some spotty high-based showers from the associated mid clouds/moisture. Present indications are this wave and the mid level moisture will continue to push east this morning with a few sprinkles still possible after 12z in south central IL. The other short wave is currently centered near the Nebraska/Iowa border into northeast KS and is more problematic. The associated convection has generated a sizeable cloud canopy which has not been resolved by the models and will overspread a good portion of the CWA this morning. Unclear is how it will evolve with time - i.e. thinning, but the RAP has this wave centered through far eastern IA at midday and the current thought is to have quite a bit of clouds the first half of this morning then thinning and moving east by midday into early afternoon. There are also suggestions in the RAP, ECMWF, and a few of the hi-res WRFs that the southwest stretching tail of this short wave could generate a few showers across northeast MO and west central IL this afternoon and early this evening. I have added a slight chance as a result. Otherwise a warm day is on tap with well above normal temperatures expected. While the morning clouds will hamper the temp rise a bit, increasing south-southwesterly low level flow and rising low- level temperatures should compensate and will result in highs in the upper 70s to mid 80s across the area. South-southwest lower trop flow will maintain a low-level warm advection region tonight and moisture will gradually be improving. The thermal and moisture advection combined with a plume of relatively steep mid level lapse rates will result in a swath of weak instability across northern parts of the CWA in advance of the southward sinking cold front. While the front will remain well north of the CWA at daybreak Monday, northwest steering flow will help push at least scattered showers and thunderstorms or thunderstorm clusters into northeast MO and west central IL late tonight. We could also see spotty WAA generated showers well in advance of the activity that has moved off the front, hence the low pops all the way down to St. Louis. Glass .LONG TERM: (Monday through Saturday) Issued at 325 AM CDT Sun May 3 2015 The west-east oriented cold front will ooze southward out of IA and northern IL into northern sections of the CWA by early Monday evening. Ongoing showers and thunderstorms at daybreak should dissipate by midday. Heating and continued low-level moistening in their wake will result in weak-moderate instability along the frontal zone and the combo of a migrating impulse and good low level convergence along the boundary should result in extensive convective development during the later half of the afternoon spanning from KS across northern MO/southern IA into central IL. A broad veering southwesterly LLJ will maintain numberous thunderstorms/clusters during the evening, with the activity shunting a bit northward overnight in response to increasing ridging aloft and a slight northward shift in the frontal zone. The front will continue to shift northward on Tuesday as ridging aloft continues to build from the lower TN Valley into the upper MS Valley. There are some suggestions of air mass type convection across southern portions of the CWA but I`m not sold on it and have kept pops in the slight range and confined the coverage. Otherwise Tuesday will be another day of above normal temps with highs in the 80s. This warmth will persist on Wednesday and even into Thursday with the chance of showers and thunderstorms slowly increasing west-east over the 2 day period as the ridging aloft shunts east and southwest flow aloft becomes more dominant with time. The greatest threat of showers and thunderstorms in the extended period will be Friday-Saturday with an active southwest flow aloft, moist unstable warm sector, and slowly encroaching cold front. Glass && .AVIATION: (For the 06z TAFs through 06z Sunday Night) Issued at 1128 PM CDT Sat May 2 2015 VFR flight conditions are expected to continue through Sunday. Very light showers continue to drift southeast over parts of the area. Shower activity should continue to diminish slowly through the rest of the night. Showers are so light that there should be no impact to operations if one does move over an airport. Low level wind shear is a good possibility especially over central and northeast Missouri as well as west central Illinois. Models are indicating that the wind will increase to around 30kts between 400-800 ft providing +/- 20-25 kts of shear from the surface to those altitudes. Shear values look to fall off further east/southeast. Expect increasing south-southwest wind on Sunday morning with gusts to around 20kts during the afternoon. Specifics for KSTL: VFR flight conditions are expected to continue through Sunday. There may be a sprinkle or two through the rest of the night, but airport operations are not expected to be affected. Some low level wind shear still looks possible at Lambert, but values do not look high enough to warrant a mention in the TAF at this time. Wind will increase from the south-southwest Sunday morning with gusts to around 20kts during the afternoon. Carney && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
436 AM CDT SUN MAY 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 433 AM CDT SUN MAY 3 2015 BIGGEST CHALLENGE WILL BE DETERMINING CHANCES AND TIMING OF SHOWERS/THUNDERSTORMS AS WELL AS THE POTENTIAL FOR STRONG STORMS. ANOTHER CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES FOR TODAY. SPLIT FLOW FOR TODAY...CAUGHT BETWEEN THE NORTH AND SOUTH STREAMS. LOCAL SYNOPTIC FLOW WILL BE ZONAL...BUT TURN MORE SOUTHWEST TONIGHT AS A NEGATIVELY TILTED BROAD UPPER LEVEL TROUGH ENTERS THE SOUTHWESTERN UNITED STATES. AT THE SURFACE...A COLD FRONT IS ON ITS WAY SOUTH ACROSS SOUTH DAKOTA. THE TIMING OF THIS FRONT SUGGESTS THAT WE WILL WARM UP SIGNIFICANTLY DUE TO COMPRESSIONAL WARMING. MODELS ARE GENERALLY NOT PICKING UP ON THIS WELL ENOUGH...SO I AM GOING OUT ON A BIT OF A LIMB AND GOING QUITE A BIT MORE THAN GENERAL GUIDANCE IN THE MID 80S. GOING FOR 91 FOR THE TRI-CITIES...FAVORING THE HI RES NMM SOLUTION. BELIEVE IT OR NOT...THIS WOULD BREAK OUR RECORD IN HASTINGS BY 2 DEGREES AND BE ONE DEGREE SHORT OF THE RECORD HIGH IN GRAND ISLAND. THE RAP MODEL BUMPS UP TEMPERATURES EVEN MORE IN NORTH CENTRAL KANSAS TO THE MID 90S. THESE WARMER TEMPERATURES WOULD HAVE PUT US IN THE REALM OF APPROACHING CRITICAL FIRE WEATHER ISSUES IF IT WERE NOT FOR THE FACT THAT WE HAVE GREENED UP. CHANCES OF PRECIPITATION ARE NOT CERTAIN. COVERAGE IS A BIT SPOTTY UNTIL THE CAP BREAKS IN THE EVENING. EVENT THEN...COVERAGE IS IN QUESTION...ESPECIALLY DEPENDING ON THE EXACT PLACEMENT OF THE FRONT WHEN STORMS FIRE. WE WILL PROBABLY NEED A HIGHER NARROW CORRIDOR OF CATEGORICAL CHANCES OF SHOWERS/THUNDERSTORMS...BUT AT THIS TIME...THAT IS VERY DIFFICULT TO DETERMINE...ESPECIALLY AS THE FRONT MAY TEMPORARILY STALL FOR A SHORT TIME TOWARD EVENING. A SECONDARY IMPULSE WITHIN MID-LEVEL FLOW COULD BOOST CHANCES OF RAIN OVERNIGHT...PROBABLY IN OUR SOUTH. I DO NOT GO OVER A 60 PERCENT CHANCE ANYWHERE IN THE CWA...AND HANG AROUND 40-50 PERCENT CHANCE FOR THE TRI-CITIES. AS FOR STRONG/SEVERE CHANCES...WE COULD GET SOME STRONG STORMS WITH MARGINAL INSTABILITY OF 500 TO 1500 J/KG AND LOW- LEVEL WIND SHEAR APPROACHING 30-35 IN OUR NORTH...BUT PROBABLY LOWER IN MOST OF THE REST OF THE CWA. THIS COULD BE ENOUGH TO GIVE US SOME STRONG STORMS WITH NICKEL SIZE HAIL AND PERHAPS A STRONG WIND GUST...BUT THE BETTER SUPPORT FOR SEVERE WEATHER LOOKS LIKE IT SHOULD BE EAST/NORTHEAST OF THE CWA. WENT WITH SIMILAR LOWS FOR TONIGHT COMPARED TO THE PREVIOUS FORECAST AND STUCK WITH SUPERBLEND IN THE 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 433 AM CDT SUN MAY 3 2015 PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND THE MULTIPLE CHANCES FOR THUNDERSTORMS THROUGH THE ENTIRE PERIOD. THE UNSETTLED WEATHER PATTERN HAS SETTLED IN ACROSS THE REGION BY THE START OF THE PERIOD MON/MON NIGHT...WITH MODELS SHOWING THE AREA UNDER SOUTHWESTERLY FLOW ALOFT...WITH THE PARENT LOW PRESSURE OVER SRN CALIFORNIA AND WEAK RIDGING EXTENDING NORTH FROM THE GULF COAST INTO PORTIONS OF THE MIDWEST. MAY HAVE SOME LINGERING PRECIP ACROSS THE AREA DURING THE MORNING HOURS FROM OVERNIGHT ACTIVITY...BUT WOULD THINK THERE WOULD BE A LULL AT SOME POINT. HARD TO PINPOINT EXACTLY WHERE THAT LINGERING ACTIVITY MAY BE...SO HAVE CHANCE POPS ACROSS THE ENTIRE CWA. AT THE SFC...MODELS CONTINUE TO BE IN PRETTY GOOD AGREEMENT SHOWING THE PLACEMENT OF THE MAIN SFC FRONT OVER SRN PORTIONS OF THE CWA NEAR THE NEB/KS STATE LINE...WITH SOME SHOWING A LOW PLACED IN CLOSE PROXIMITY TO THE S/SWRN CORNER OF THE CWA. THE PLACEMENT OF THE SFC FRONT...UNCERTAINTY WITH THE AMOUNT OF SKY COVER /LIKELY HIGH/ AND ANY LINGERING PRECIP MAKES THE HIGH TEMP FORECAST TRICKY. MUCH OF SC NEB IS LOOKING AT ERLY WINDS NORTH OF THE FRONT...WITH MORE SRLY WINDS ACROSS NC KS. FORECAST HIGH TEMP IS A BLEND...AND COULD SEE CLOSE TO A 20 DEGREE GRADIENT ACROSS THE CWA /SOME MODELS ARE MORE DRASTIC/...WITH ARND 60 IN THE NORTH TO NEAR 80 IN THE FAR SOUTH. DURING THE AFTERNOON HOURS AND INTO THE EVENING/OVERNIGHT...THIS FRONTAL BOUNDARY WILL BE A FOCUS FOR ADDITIONAL THUNDERSTORM DEVELOPMENT AS YET ANOTHER DISTURBANCE MAKES ITS WAY INTO THE REGION...AIDED ALSO BY AN INCREASING LLJ. SEVERE WEATHER REMAINS A CONCERN WITH MODEST INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR...LARGE HAIL/DAMAGING WINDS REMAIN THE PRIMARY CONCERNS...BUT WILL HAVE TO MONITOR THE POTENTIAL FOR AN ISOLATED TORNADO WITH THOSE MORE ERLY WINDS/INCREASED LOW LEVEL SHEAR IN THE AREA. SPC DAY 2 OUTLOOK SLIGHT RISK AREA INCLUDES ROUGHLY THE SERN HALF OF THE CWA. SIMILAR TO MONDAY...TUESDAY MORNING MAY HAVE SOME LINGERING ACTIVITY FROM OVERNIGHT...BUT MODELS SUGGEST THE OVERALL COVERAGE MAY NOT BE AS WIDESPREAD. THE MAIN UPPER LEVEL LOW HAS SHIFTED EAST INTO THE FOUR CORNERS REGION BY TUESDAY MORNING...AND MODELS CONTINUE TO SHOW THE POTENTIAL FOR THE LOW TO WEAKEN SOME/FILL...AS IT COMES UNDER INCREASING INFLUENCE OF A STRONGER UPPER LEVEL LOW MOVING INTO THE PAC NW REGION. AT THE SFC...DURING THE DAYTIME HOURS...THE FRONTAL BOUNDARY CONTINUING TO MEANDER AROUND CENTRAL PORTIONS OF THE CWA LOOKS TO PUSH NORTH AS A WARM FRONT...WITH MOST MODELS SHOWING SRLY WINDS IN PLACE ACROSS THE ENTIRE CWA DURING THE AFTERNOON. MODELS CONTINUE TO SHOW THE BETTER THUNDERSTORMS CHANCES ACROSS WRN PORTIONS OF THE CWA DURING THE AFTERNOON...SPREADING ACROSS THE REST OF THE CWA OVERNIGHT AS LIFT CONTINUES TO INCREASE WITH THE APPROACHING MAIN UPPER TROUGH/LOW...WHICH IS STARTING TO MAKE MORE OF A PUSH ONTO THE THE PLAINS DURING THE LATE TUES NIGHT HOURS/WED MORNING. WED/WED NIGHT CONTINUES TO BE THE PERIOD GENERALLY SHOWN BY MODELS WHEN THAT MAIN TROUGH AXIS /CLOSED LOW?/ MAKES ITS TREK NE THROUGH THE REGION...AS THAT STRONGER UPPER LEVEL LOW DIGS FURTHER SOUTH ALONG THE WEST COAST. THE HIGH CHANCE/LOW END LIKELY POPS CONTINUE IN THE FORECAST...SIMILAR TO PERIODS PRIOR AND FOLLOWING...HARD TO TRIM AREAS OUT OR RAISE POPS IN OTHERS WHEN SO MANY DETAILS HAVE YET TO BE IRONED OUT. THE LOCATION OF THE SFC LOW/ASSOCIATED BOUNDARIES LOOK TO BE PLAYING A BIGGER ROLE/FOCUS FOR CONVECTIVE DEVELOPMENT NEAR/ACROSS THE CWA...SO AS THEIR ULTIMATE PLACEMENT BECOMES MORE CLEAR IN THE COMING MODEL RUNS...CAN PIN DOWN BETTER DETAILS WITH POPS AND SEVERE WEATHER POTENTIAL. THROUGH THE REST OF THE LONG TERM PERIOD THURSDAY THROUGH SATURDAY...ONE NOTABLE DISTURBANCE MOVES OUT...BUT SOUTHWESTERLY FLOW REMAINS IN PLACE IN THE UPPER LEVEL AS THAT NEXT LOW PRESSURE SYSTEM CONTINUES TO DIG FURTHER SOUTH INTO CALIFORNIA. PIECES OF SHORTWAVE ENERGY ASSOCIATED WITH THAT LOW LOOK TO CONTINUE TO BRING AT LEAST PERIODIC THUNDERSTORM CHANCES...KEPT THE FORECAST CLOSE TO THE CR INIT/SUPERBLEND OUTPUT. && .AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1257 AM CDT SUN MAY 3 2015 WIND SHEAR WILL BE A CONCERN FOR THE FIRST FEW HOURS DURING THE OVERNIGHT...BUT SHOULD WANE FROM WEST TO EAST AS THE LOW-LEVEL JET MOVES EAST. ANY CLOUDS SHOULD REMAIN PRIMARILY MID-HIGH LEVEL OVERNIGHT INTO SUNDAY. AS A COLD FRONT APPROACHES FROM THE NORTH...THERE WILL BE AN INCREASED CHANCE OF SHOWERS/T-STORMS. && .CLIMATE... ISSUED AT 433 AM CDT SUN MAY 3 2015 PREDICTED HIGH TODAY: HASTINGS 91 GRAND ISLAND 91 RECORD HIGH: HASTINGS 89 (1959) GRAND ISLAND 92 (1959) && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...HEINLEIN LONG TERM...ADP AVIATION...HEINLEIN CLIMATE...HEINLEIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
322 AM CDT SUN MAY 3 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 320 AM CDT SUN MAY 3 2015 TODAY...STORMS SHOULD CONTINUE EASTWARD OUT OF THE FORECAST AREA EARLY THIS MORNING. HIGH RES MODELS ARE IN GOOD AGREEMENT WITH THAT. STORMS LAST EVENING DID PRODUCE SOME LARGE HAIL AND A FEW SPOTS RECEIVED STRONG WINDS AS STORMS MIXED DOWN A STRONG LOW LEVEL JET. AS OF AROUND 07Z RUC MODEL INITIALIZATION SHOWED WINDS AT AROUND 1 KM AGL OF AROUND 40-50 KNOTS STRETCHING FROM WESTERN OKLAHOMA INTO SOUTHEAST NEBRASKA AND PARTS OF IOWA. THESE WINDS WILL DECREASE THIS MORNING. COLD FRONT AS OF 08Z STRETCHED FROM NORTHEAST MINNESOTA BACK INTO WESTERN SOUTH DAKOTA. THAT FRONT WILL MOVE SOUTHEAST INTO NORTHEAST NEBRASKA THIS AFTERNOON. LOOK FOR HIGHS IN THE MID TO UPPER 80S AT MOST SPOTS TODAY WITH A FEW HIGHS AROUND 90 POSSIBLE. THIS WILL CREATE CAPE VALUES FROM 1500 TO 2500 J/KG BY MID AFTERNOON. EXPECT CAP TO BREAK NEAR THE FRONT BY MID/LATE AFTERNOON. SOME MODELS ALSO HINT AT THE CAP WEAKENING FARTHER SOUTH...BUT WITH A LACK OF FOCUS AT THAT TIME WILL KEEP HIGHEST POPS CLOSER TO THE FRONT. SOME SEVERE STORMS APPEAR POSSIBLE...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS. GENERALLY USED A BLEND OF SHORT RANGE GUIDANCE FOR TONIGHT WITH THE HIGHEST WEIGHT GIVEN TO THE 00Z HIGH RES WRF-ARW MODEL. LIKE SOME OF THE OTHER MODELS...IT DEVELOPED STORMS LATE AFTERNOON THEN MOVED THEM SOUTH AND EAST. SOME STORMS MAY CONTINUE TO BE SEVERE IN THE EVENING. COVERAGE SHOULD DECREASE AFTER MIDNIGHT. CONVECTION WILL LIKELY FORCE THE FRONT DOWN AT LEAST AS FAR AS SOUTHEAST NEBRASKA AND MAYBE INTO NORTHEAST KANSAS BY 12Z MONDAY. MOST MODELS SHOW LIFT OCCURRING OVER THE BOUNDARY DURING THE DAY MONDAY WITH PCPN COVERAGE INCREASING...SO HAVE POPS INCREASING TO MATCH THAT. TWO CLUSTERS OF STORMS MAY TAKE SHAPE BY LATE AFTERNOON OR EARLY EVENING. ONE NEAR THE NEBRASKA/SOUTH DAKOTA BORDER AND ANOTHER LIFTING FROM NORTHERN KANSAS THROUGH OUR AREA AND TOWARD CENTRAL IOWA MONDAY NIGHT. TUESDAY...WE MAY SEE SOMEWHAT OF A BREAK IN THE WIDESPREAD PCPN... AT LEAST OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. HAVE POPS RANGING FROM 15 TO 50 PERCENT...HIGHEST IN NORTHEAST NEBRASKA. SOUTHERLY FLOW WILL INCREASE AND HELP A WARM FRONT LIFT NORTH OF THE AREA. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 320 AM CDT SUN MAY 3 2015 PATTERN WILL BE ACTIVE MUCH OF THIS PERIOD. A LARGE MID TROPOSPHERIC TROUGH SHOULD BE OVER THE WESTERN UNITED STATES AT THE START OF THIS PERIOD WITH EMBEDDED SHORTWAVES. ONE OF THESE WAVES WILL LIFT ACROSS MID AMERICA WEDNESDAY/WEDNESDAY NIGHT...WHILE A CLOSED LOW STARTS TO DIG SOUTHWARD FROM THE PACIFIC NORTHWEST. THIS WILL GENERALLY KEEP OUR AREA IN SOUTHWEST FLOW WITH A DECENT SUPPLY OF LOW LEVEL MOISTURE FOR SHOWERS AND STORMS TO WORK WITH. MODEL AGREEMENT STARTS TO FALL OFF BY DAY 7...SO CONFIDENCE FALLS TO AVERAGE BY DAY 7. TEMPERATURES AND PCPN SHOULD BE AT OR ABOVE NORMAL FOR THIS PERIOD. && .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1215 AM CDT SUN MAY 3 2015 LOOK FOR SCT TSRA WILL MOVE EASTWARD AWAY FROM THE TAF SITES THE NEXT FEW HOURS. TSRA SHOULD DEVELOP ALONG A COLD FRONT NEAR KOFK BY MID AFTERNOON THEN MOVE/DEVELOP SOUTHEAST TOWARD KOMA AND KLNK THROUGH THE EVENING. MVFR OR LOWER CEILINGS AND VSBYS WILL BE POSSIBLE IN THE TSRA. OTHERWISE...LOW LEVEL WIND SHEAR EXPECTED EARLY THIS MORNING WITH STRONG LOW LEVEL JET AROUND 1000-3000 FEET AGL. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...PEARSON/MILLER LONG TERM...MILLER AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1234 AM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 1234 AM CDT SUN MAY 3 2015 LATEST BOWMAN RADAR CONTINUES TO SHOW AN EXPANDING AREA OF REFLECTIVITY`S IN SOUTHEAST MONTANA AND INTO SOUTHWEST NORTH DAKOTA...WITH MORE ISOLATED ECHOES FARTHER NORTH. THE HRRR COMPOSITE REFLECTIVITY SEEMS TO BE HANDLING THE CURRENT SCENARIO WELL AND HAVE FOLLOWED A BLEND OF THE HRRR AND NAM12. THE NAM12 SHOWS A LAYER OF FRONTOGENESIS/750MB-650MB...INITIATING OVER SOUTHWEST NORTH DAKOTA AND SHIFTING INTO SOUTH CENTRAL THROUGH 12Z SUNDAY. VERTICAL MOTION/MAX OMEGA FIELD OCCURRING ATOP THIS LAYER WILL RESULT IN LOWERING CLOUDS TO BETWEEN 7KFT AND 10KFT OVERNIGHT...SUFFICIENT ENOUGH FOR PRECIPITATION TO REACH THE GROUND. AFTER COLLABORATING WITH OUR NEIGHBORING OFFICES...HAVE EXPANDED POPS OVERNIGHT FARTHER NORTH AND EAST...RANGING BETWEEN ISOLATED AND SCATTERED THROUGH 15Z SUNDAY. WILL LOOK MORE INTO THE FIRE WEATHER FORECAST AND POSSIBLE HEADLINES IN THE NEXT FORECAST. UPDATE ISSUED AT 1003 PM CDT SAT MAY 2 2015 RADAR RETURNS SOUTHEAST AND ACROSS THE WEST. WILL MAINTAIN SLIGHT CHANCE SHOWERS SOUTHEAST THIS EVENING AND SOUTHWEST OVERNIGHT. WHILE NOT MUCH WILL REACH THE GROUND SOUTHWEST LATE TONIGHT...RADAR RETURNS VIA BOWMAN RADAR APPEAR ROBUST ENOUGH FOR AN ISOLATED SHOWER SO WILL KEEP SOME LOW POPS IN 06-12Z. UPDATE ISSUED AT 825 PM CDT SAT MAY 2 2015 RED FLAG WAS ALLOWED TO EXPIRE AT 02Z. NO OTHER UPDATES AT THIS TIME. UPDATE ISSUED AT 658 PM CDT SAT MAY 2 2015 COLD FRONT NEARLY THROUGH THE JAMES RIVER VALLEY...SO HAVE SCALED BACK ON EVENING PRECIPITATION/THUNDER CHANCES A BIT...ENDING ALL POPS OVER MY FAR SOUTHEAST BY 04Z. WINDS SHOULD TAPER OFF QUICKLY BETWEEN NOW AND SUNSET (~01Z)...SO WILL BE ABLE TO EXPIRE THE RED FLAG WARNING AS SCHEDULED BY 02Z. REMAINDER OF THE FORECAST ON TRACK...SO NO MAJOR CHANGES. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 245 PM CDT SAT MAY 2 2015 CURRENT SURFACE ANALYSIS PLACES COLD FRONT PUSHING THROUGH NORTH CENTRAL INTO WESTERN NORTH DAKOTA WHILE SHOWERS AND THUNDERSTORMS FIRE UP NEAR A PRE-FRONTAL TROUGH PUSHING OVER NORTHEAST INTO SOUTH CENTRAL NORTH DAKOTA. UPPER LEVEL ANALYSIS PLACES WEAK SHORT WAVE SLIDING THROUGH WEST/SOUTHWEST FLOW AHEAD OF A LOW AMPLITUDE TROUGH PUSHING TO THE EAST OF THE ROCKIES. FOR THE REST OF THIS AFTERNOON INTO TONIGHT...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP AND PUSH TO THE EAST. MOST ACTIVITY SHOULD SLIDE TO THE EAST OF OUR AREA EARLY THIS EVENING PER LATEST HIGH-RES IMAGERY WHICH HAS HAD A RATHER GOOD HANDLE ON THE TIMING OF THE STORMS. THERE REMAINS A LOW SEVERE WIND/HAIL CONCERN GIVEN STEEP MID-LEVEL LAPSE RATES AND DRY LOW LAYERS...THOUGH WITH WEAK FORCING AND MODEST INSTABILITY DO NOT EXPECT THIS TO BECOME WIDESPREAD. ANOTHER WEAK WAVE PUSHES INTO THE SOUTHWEST LATE TONIGHT WHICH MAY BRING A FEW LIGHT SHOWERS. ON SUNDAY...QUIET WEATHER EXPECTED IN THE WAKE OF THE COLD FRONT BRINGING NORTHWEST WINDS AND DRY CONDITIONS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 245 PM CDT SAT MAY 2 2015 THE MAIN CONCERN IN THE LONG TERM WILL BE THE ACTIVE WEATHER PATTERN TAKING SHAPE FOR THE MIDDLE AND END OF NEXT WEEK. NEAR TERM MODEL SOLUTIONS SUGGEST A SMALL CHANCE OF SHOWERS IN THE SOUTHWEST PART OF THE STATE SUNDAY NIGHT INTO MONDAY...BUT ANY RAINFALL LOOKS SPOTTY. ATTENTION THEN SHIFTS TO A LARGE TROUGH /H5 LOW WHICH WILL MOVE INTO THE WESTERN UNITED STATES. AHEAD OF THE LOW...AN INITIAL SHORT WAVE WILL EJECT INTO THE CENTRAL AND NORTHERN PLAINS...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TUESDAY NIGHT THAT CONTINUES THROUGH THURSDAY. A BRIEF H5 RIDGE MOVES INTO THE NORTHERN PLAINS THURSDAY NIGHT AND FRIDAY...HOWEVER THE LARGE TROUGH ACROSS THE WESTERN UNITED STATES LIFTS INTO THE REGION FOR NEXT WEEKEND. IT APPEARS MUCH OF THE AREA COULD RECEIVE MUCH NEEDED RAIN AS WE HEAD INTO THIS MORE ACTIVE PATTERN. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1234 AM CDT SUN MAY 3 2015 A VCSH WILL CONTINUE FOR KDIK/KBIS/KJMS UNTIL AROUND 15Z-8Z SUNDAY AS AN ISOLATED TO SCATTERED RAIN SHOWERS MOVE FROM SOUTHEAST MONTANA ACROSS CENTRAL AND SOUTHERN NORTH DAKOTA. DESPITE THE THREAT OF SHOWERS THROUGH SUNDAY MORNING...CIGS/VSBYS WILL REMAIN VFR. AFTER 18Z SUNDAY...EXPECT A CLEARING SKY WHICH WILL CONTINUE THROUGH THE REST OF THE TAF PERIOD. && .FIRE WEATHER... ISSUED AT 825 PM CDT SAT MAY 2 2015 ON SUNDAY...NEAR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED AS MINIMUM RELATIVE HUMIDITY VALUES RANGE AROUND 20 TO 25 PERCENT WHILE NORTHWEST WINDS INCREASE TO AROUND 15 TO 20 MPH. CONDITIONS WILL BE MONITORED TO SEE IF A FIRE WEATHER HEADLINE WILL BE NEEDED. WETTING RAINS ARE EXPECTED OVER THE REGION TOWARDS THE MIDDLE OF NEXT WEEK. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...KS SHORT TERM...JJS LONG TERM...CK AVIATION...KS FIRE WEATHER...JJS/NH
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1152 AM EDT SUN MAY 3 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE OVER THE EASTERN UNITED STATES TODAY WILL GRADUALLY MOVE OFFSHORE ON MONDAY. A COLD FRONT IS FORECAST TO WEAKEN AS IT DROPS SOUTHWARD ACROSS THE AREA TUESDAY THROUGH EARLY WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK. THE HIGH WILL EVENTUALLY SHIFT OFF THE EAST COAST NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 12Z UA ANLYS VERY DRY AT 850MB AND 925MB LEVELS IN THE EASTERN CONUS. HAVE TO CLIMB TO 700MB TO FIND SOME APPRECIABLE MOISTURE. 925MB TEMPS IN THE GREAT LAKES AROUND 18C WITH 850MB TEMPS NORTH OF 10C. THAT WILL BE OUR AIR MASS TOMORROW. WE ARE PLANNING NO BIG CHANGES WITH THE NEXT UPDATE. 12Z MODEL DATA EXCEPT FOR THE GFS AND ALL OTHER MESOSCALE MODELS KEEP US DRY INTO THIS EVENING. THE GFS HAS HAD THE HIGHEST .01" ISOHYET WET BIAS (AMONG IT, SREF, NAM AND EC) WI 24HR DURING THE PAST MONTH AND THE LOWEST QPF SKILL SCORE OF ALL THOSE MODELS IN THE NORTHEAST WITH QPF OF LESS THAN .75". THERMALLY IT IS SIMILAR TO YESTERDAY WITH LOCATIONS NW RISING FASTER THAN FORECAST WITH SOME LOCALES LAGGING NEAR THE COAST. OVERALL WE ARE WITHIN ABOUT 3F OF EXPECTATIONS, SO JUST SLIGHT ADJUSTMENTS WILL BE MADE. HIGH PRES WILL BE OVER THE SERN CONUS TODAY. SWLY FLOW WILL INCREASE AND TEMPS WILL WARM IN RESPONSE. HIGHS ARE EXPECTED TO BE IN THE MID TO UPPER 70S, WITH SOME LOCATIONS MAKING A RUN AT 80 DEGREES. NO PRECIP IS ANTICIPATED. THERE WILL BE SOME SCT CLOUDS ON AN OTHERWISE BEAUTIFUL DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... THE AREA OF HIGH PRES WILL MOVE EWD AND OFF THE CST AND A GENLY CLEAR SKY IS IN STORE WITH LIGHT WIND. && .LONG TERM /MONDAY THROUGH SATURDAY/... THE CENTER OF SURFACE HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC COAST ON MONDAY. SOUTHWESTERLY RETURN FLOW AROUND THE HIGH WILL DRAW EVEN WARMER AND MORE HUMID AIR UP THE EASTERN SEABOARD. MONDAY WILL CONTEND WITH APRIL 18TH FOR THE WARMEST DAY SO FAR THIS YEAR WITH HIGHS 80-85 DEGREES (EXCEPT COOLER ALONG THE COAST AND IN THE POCONOS). CONDITIONS ACROSS THE FORECAST AREA WILL BE DRY THROUGH MONDAY NIGHT OWING TO STRONG SUBSIDENCE PRESENT BENEATH THE H8 RIDGE. A COLD FRONT WILL MOVE SLOWLY SOUTHWARD THROUGH THE AREA TUESDAY AFTERNOON AND NIGHT. CLOUDS OVERSPREADING NORTHEAST PA AND NORTHWEST NJ WILL RESULT IN SLIGHTLY COOLER HIGHS IN THE 70S ON TUESDAY. FARTHER SOUTH IN THE WARM SECTOR, HIGHS TUESDAY HAVE THE POTENTIAL TO BE CLOSE TO MONDAY`S FROM ABOUT PHILLY SOUTHWARD IF THE FRONT AND ITS ASSOCIATED CLOUD COVER HANGS BACK TO THE NORTH. MOISTURE WILL POOL ALONG THE FRONT AS NOTED BY PWATS INCREASING TO NEAR 1.5 INCHES AND SURFACE DEWPOINTS TO NEAR 60F BY THE AFTERNOON. BUFKIT SOUNDINGS FROM THE 00Z GFS AND 21Z SREF SHOW MODEST INSTABILITY (ML CAPE AROUND 500 J/KG) WHILE THE 00Z NAM DEPICTS A CONSIDERABLY MORE UNSTABLE ENVIRONMENT (ML CAPE AOA 1000 J/KG). WENT MORE CONSERVATIVE WITH FORECAST COVERAGE OF THUNDERSTORMS DUE TO THE PRESENCE OF WEAK SHEAR AND LIMITED FORCING IN ADDITION TO THE QUESTIONABLE INSTABILITY. A GENERAL WEAKENING TREND IS EXPECTED WITH THE CONVECTION AFTER SUNSET, ALTHOUGH SHOWERS MAY LINGER INTO THE OVERNIGHT AS SLIGHTLY BETTER LIFT ASSOCIATED WITH AN UPPER SHORTWAVE TROUGH ARRIVES LATE. THE FRONT MAY EITHER CONTINUE TO SAG SOUTHWARD SLOWLY OR EVEN STALL OVER THE DELMARVA WEDNESDAY MORNING. LIFT ASSOCIATED WITH THE FRONT ITSELF SHOULD WEAKEN AS THE BOUNDARY IS EXPECTED TO BECOME INCREASINGLY DIFFUSE. CONSEQUENTIALLY, COVERAGE OF SHOWERS EXPECTED TO BE RELATIVELY LOW ON WEDNESDAY. THUNDERSTORM CHANCES CONFINED TO THE LOWER DELMARVA, WHERE THESE LOCATIONS HAVE THE BEST CHANCE OF RESIDING IN THE WARM SECTOR TO THE SOUTH OF THE BOUNDARY. THE CAA BEHIND THE FRONT IS NOT SIGNIFICANT, SO THE TREND OF ABOVE NORMAL TEMPS SHOULD CONTINUE INTO WEDNESDAY. HOWEVER, WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF ONSHORE FLOW TO DEVELOP. THIS MAY PREVENT TEMPS FROM REACHING 70F IN THE COASTAL PLAIN, ESPECIALLY THE EASTERLY WIND BECOMES ENHANCED BY A SEABREEZE. EXPANSIVE HIGH PRESSURE OVER THE EASTERN SEABOARD WILL PROVIDE A MAINLY DRY PATTERN THURSDAY THROUGH SATURDAY. THE HUMIDITY IS FORECAST TO INCREASE A BIT FRIDAY AND SATURDAY AS SOUTHERLY RETURN FLOW DEVELOPS WITH THE SURFACE HIGH MOVING OFFSHORE. CANNOT RULE OUT THE POSSIBILITY OF A A SHOWER DEVELOPING DURING THE AFTERNOON HOURS FRIDAY AND SATURDAY BUT THE SUBSIDENCE INVERSION UNDERNEATH THE RIDGE SHOULD MINIMIZE THE CONVECTIVE POTENTIAL. ABOVE NORMAL TEMPS WILL PERSIST WITH HIGHS IN THE 70S TO NEAR 80F EACH DAY. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDS WILL PREVAIL THRU THE TAF PD WITH HIGH PRES TO THE SE TODAY MOVG OFFSHORE TONIGHT. THE FLOW WILL BECOME SWLY BY AFTN BUT WILL BE LESS THAN 10 KTS. ONLY SCT CLOUDS ARE ANTICIPATED. WITH LIGHT FLOW, STILL EXPECTING ANOTHER SEA BREEZE AT KACY AND KMIV. AT THESE LOCATIONS, WIND COULD REACH 10 KT OR SO. OUTLOOK... MONDAY AND MONDAY NIGHT...VFR. SWLY MAY GUST TO 20 KT LATE IN THE DAY. TUESDAY AND TUESDAY NIGHT...PREDOMINATELY VFR. SCT SHRA AND ISO TSRA DURING THE AFTERNOON AND NIGHT COULD YIELD LOCAL MVFR/IFR CONDITIONS. WEDNESDAY...SHRA MAY LINGER INTO WEDNESDAY BUT MOST OF THE TERMINALS SHOULD DRY OUT. SOME MODEL SOLUTIONS ARE INDICATING EASTERLY WINDS TO DEVELOP. WILL HAVE TO WATCH FOR LOW CLOUDS AND MVFR CIGS TO ACCOMPANY MARINE LAYER. WEDNESDAY NIGHT AND THURSDAY...VFR. && .MARINE... SEAS AS OF 10 AM HAVE DROPPED TO 4.6 FEET AT BOTH BUOY9 AND 65. IN ADDITION, THE PERIOD HAS INCREASED TO AROUND 10 SECONDS. WITH THE DOWNWARD TREND UNDERWAY, WE WILL FINALLY PUT THIS SMALL CRAFT ADVISORY IN THE BOOKS AND HAVE NO FURTHER EXTENSION. WE ADJUSTED THE WINDS IN DELAWARE BAY THIS AFTERNOON AND EVE BASED ON HRRR AND ARW MODELS AS THEY HANDLED THE UP THE BAY BREEZE WELL YESTERDAY. NO ADDITIONAL FLAGS ARE EXPECTED DURG THE REMAINDER OF THE NR AND SHORT TERM PDS. OUTLOOK... MONDAY THROUGH THURSDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA. THE STRONGEST WINDS ARE EXPECTED MONDAY AND TUESDAY AS HIGH PRESSURE MOVES OFFSHORE AND A S-SW FLOW AROUND 15-20 KT ENSUES. && .FIRE WEATHER... RELATIVE HUMIDITY VALUES NEAR 30 PERCENT, ALONG WITH OCCASIONAL WIND GUSTS TO NEAR 20 MPH MAY ENHANCE THE FIRE WEATHER RISK LATE IN THE DAY ON MONDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...KLEIN NEAR TERM...GIGI/NIERENBERG SHORT TERM...NIERENBERG LONG TERM...KLEIN AVIATION...KLEIN/NIERENBERG MARINE...GIGI/KLEIN/NIERENBERG FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1052 AM EDT SUN MAY 3 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE OVER THE EASTERN UNITED STATES TODAY WILL GRADUALLY MOVE OFFSHORE ON MONDAY. A COLD FRONT IS FORECAST TO WEAKEN AS IT DROPS SOUTHWARD ACROSS THE AREA TUESDAY THROUGH EARLY WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK. THE HIGH WILL EVENTUALLY SHIFT OFF THE EAST COAST NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO BIG CHANGES MADE WITH THIS UPDATE. 12Z SOUNDINGS HAVE HIGH TEMPS REACHING THE 70S TODAY, BUT WITH CONTINUED AIR MASS MODIFICATION AND SOME WAA, SOME LOW 80S ARE POSSIBLE INLAND. SINCE THE HRRR DID PRETTY WELL WITH THE SEA BREEZE FRONT YESTERDAY, WE ADJUSTED WINDS BASED ON ITS LATEST RUN OR TWO. HIGH PRES WILL BE OVER THE SERN CONUS TODAY. SWLY FLOW WILL INCREASE AND TEMPS WILL WARM IN RESPONSE. HIGHS ARE EXPECTED TO BE IN THE MID TO UPPER 70S, WITH SOME LOCATIONS MAKING A RUN AT 80 DEGREES. NO PRECIP IS ANTICIPATED. THERE WILL BE SOME SCT CLOUDS ON AN OTHERWISE BEAUTIFUL DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... THE AREA OF HIGH PRES WILL MOVE EWD AND OFF THE CST AND A GENLY CLEAR SKY IS IN STORE WITH LIGHT WIND. && .LONG TERM /MONDAY THROUGH SATURDAY/... THE CENTER OF SURFACE HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC COAST ON MONDAY. SOUTHWESTERLY RETURN FLOW AROUND THE HIGH WILL DRAW EVEN WARMER AND MORE HUMID AIR UP THE EASTERN SEABOARD. MONDAY WILL CONTEND WITH APRIL 18TH FOR THE WARMEST DAY SO FAR THIS YEAR WITH HIGHS 80-85 DEGREES (EXCEPT COOLER ALONG THE COAST AND IN THE POCONOS). CONDITIONS ACROSS THE FORECAST AREA WILL BE DRY THROUGH MONDAY NIGHT OWING TO STRONG SUBSIDENCE PRESENT BENEATH THE H8 RIDGE. A COLD FRONT WILL MOVE SLOWLY SOUTHWARD THROUGH THE AREA TUESDAY AFTERNOON AND NIGHT. CLOUDS OVERSPREADING NORTHEAST PA AND NORTHWEST NJ WILL RESULT IN SLIGHTLY COOLER HIGHS IN THE 70S ON TUESDAY. FARTHER SOUTH IN THE WARM SECTOR, HIGHS TUESDAY HAVE THE POTENTIAL TO BE CLOSE TO MONDAY`S FROM ABOUT PHILLY SOUTHWARD IF THE FRONT AND ITS ASSOCIATED CLOUD COVER HANGS BACK TO THE NORTH. MOISTURE WILL POOL ALONG THE FRONT AS NOTED BY PWATS INCREASING TO NEAR 1.5 INCHES AND SURFACE DEWPOINTS TO NEAR 60F BY THE AFTERNOON. BUFKIT SOUNDINGS FROM THE 00Z GFS AND 21Z SREF SHOW MODEST INSTABILITY (ML CAPE AROUND 500 J/KG) WHILE THE 00Z NAM DEPICTS A CONSIDERABLY MORE UNSTABLE ENVIRONMENT (ML CAPE AOA 1000 J/KG). WENT MORE CONSERVATIVE WITH FORECAST COVERAGE OF THUNDERSTORMS DUE TO THE PRESENCE OF WEAK SHEAR AND LIMITED FORCING IN ADDITION TO THE QUESTIONABLE INSTABILITY. A GENERAL WEAKENING TREND IS EXPECTED WITH THE CONVECTION AFTER SUNSET, ALTHOUGH SHOWERS MAY LINGER INTO THE OVERNIGHT AS SLIGHTLY BETTER LIFT ASSOCIATED WITH AN UPPER SHORTWAVE TROUGH ARRIVES LATE. THE FRONT MAY EITHER CONTINUE TO SAG SOUTHWARD SLOWLY OR EVEN STALL OVER THE DELMARVA WEDNESDAY MORNING. LIFT ASSOCIATED WITH THE FRONT ITSELF SHOULD WEAKEN AS THE BOUNDARY IS EXPECTED TO BECOME INCREASINGLY DIFFUSE. CONSEQUENTIALLY, COVERAGE OF SHOWERS EXPECTED TO BE RELATIVELY LOW ON WEDNESDAY. THUNDERSTORM CHANCES CONFINED TO THE LOWER DELMARVA, WHERE THESE LOCATIONS HAVE THE BEST CHANCE OF RESIDING IN THE WARM SECTOR TO THE SOUTH OF THE BOUNDARY. THE CAA BEHIND THE FRONT IS NOT SIGNIFICANT, SO THE TREND OF ABOVE NORMAL TEMPS SHOULD CONTINUE INTO WEDNESDAY. HOWEVER, WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF ONSHORE FLOW TO DEVELOP. THIS MAY PREVENT TEMPS FROM REACHING 70F IN THE COASTAL PLAIN, ESPECIALLY THE EASTERLY WIND BECOMES ENHANCED BY A SEABREEZE. EXPANSIVE HIGH PRESSURE OVER THE EASTERN SEABOARD WILL PROVIDE A MAINLY DRY PATTERN THURSDAY THROUGH SATURDAY. THE HUMIDITY IS FORECAST TO INCREASE A BIT FRIDAY AND SATURDAY AS SOUTHERLY RETURN FLOW DEVELOPS WITH THE SURFACE HIGH MOVING OFFSHORE. CANNOT RULE OUT THE POSSIBILITY OF A A SHOWER DEVELOPING DURING THE AFTERNOON HOURS FRIDAY AND SATURDAY BUT THE SUBSIDENCE INVERSION UNDERNEATH THE RIDGE SHOULD MINIMIZE THE CONVECTIVE POTENTIAL. ABOVE NORMAL TEMPS WILL PERSIST WITH HIGHS IN THE 70S TO NEAR 80F EACH DAY. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDS WILL PREVAIL THRU THE TAF PD WITH HIGH PRES TO THE SE TODAY MOVG OFFSHORE TONIGHT. THE FLOW WILL BECOME SWLY BY AFTN BUT WILL BE LESS THAN 10 KTS. ONLY SCT CLOUDS ARE ANTICIPATED. WITH LIGHT FLOW, STILL EXPECTING ANOTHER SEA BREEZE AT KACY AND KMIV. AT THESE LOCATIONS, WIND COULD REACH 10 KT OR SO. OUTLOOK... MONDAY AND MONDAY NIGHT...VFR. SWLY MAY GUST TO 20 KT LATE IN THE DAY. TUESDAY AND TUESDAY NIGHT...PREDOMINATELY VFR. SCT SHRA AND ISO TSRA DURING THE AFTERNOON AND NIGHT COULD YIELD LOCAL MVFR/IFR CONDITIONS. WEDNESDAY...SHRA MAY LINGER INTO WEDNESDAY BUT MOST OF THE TERMINALS SHOULD DRY OUT. SOME MODEL SOLUTIONS ARE INDICATING EASTERLY WINDS TO DEVELOP. WILL HAVE TO WATCH FOR LOW CLOUDS AND MVFR CIGS TO ACCOMPANY MARINE LAYER. WEDNESDAY NIGHT AND THURSDAY...VFR. && .MARINE... SEAS AS OF 10 AM HAVE DROPPED TO 4.6 FEET AT BOTH BUOY9 AND 65. IN ADDITION, THE PERIOD HAS INCREASED TO AROUND 10 SECONDS. WITH THE DOWNWARD TREND UNDERWAY, WE WILL FINALLY PUT THIS SMALL CRAFT ADVISORY IN THE BOOKS AND HAVE NO FURTHER EXTENSION. WE ADJUSTED THE WINDS IN DELAWARE BAY THIS AFTERNOON AND EVE BASED ON HRRR AND ARW MODELS AS THEY HANDLED THE UP THE BAY BREEZE WELL YESTERDAY. NO ADDITIONAL FLAGS ARE EXPECTED DURG THE REMAINDER OF THE NR AND SHORT TERM PDS. OUTLOOK... MONDAY THROUGH THURSDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA. THE STRONGEST WINDS ARE EXPECTED MONDAY AND TUESDAY AS HIGH PRESSURE MOVES OFFSHORE AND A S-SW FLOW AROUND 15-20 KT ENSUES. && .FIRE WEATHER... RELATIVE HUMIDITY VALUES NEAR 30 PERCENT, ALONG WITH OCCASIONAL WIND GUSTS TO NEAR 20 MPH MAY ENHANCE THE FIRE WEATHER RISK LATE IN THE DAY ON MONDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...KLEIN NEAR TERM...GIGI/NIERENBERG SHORT TERM...NIERENBERG LONG TERM...KLEIN AVIATION...KLEIN/NIERENBERG MARINE...GIGI/KLEIN/NIERENBERG FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
920 AM EDT SUN MAY 3 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE OVER THE EASTERN UNITED STATES TODAY WILL GRADUALLY MOVE OFFSHORE ON MONDAY. A COLD FRONT IS FORECAST TO WEAKEN AS IT DROPS SOUTHWARD ACROSS THE AREA TUESDAY THROUGH EARLY WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK. THE HIGH WILL EVENTUALLY SHIFT OFF THE EAST COAST NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO BIG CHANGES MADE WITH THIS UPDATE. 12Z SOUNDINGS HAVE HIGH TEMPS REACHING THE 70S TODAY, BUT WITH CONTINUED AIR MASS MODIFICATION AND SOME WAA, SOME LOW 80S ARE POSSIBLE INLAND. SINCE THE HRRR DID PRETTY WELL WITH THE SEA BREEZE FRONT YESTERDAY, WE ADJUSTED WINDS BASED ON ITS LATEST RUN OR TWO. HIGH PRES WILL BE OVER THE SERN CONUS TODAY. SWLY FLOW WILL INCREASE AND TEMPS WILL WARM IN RESPONSE. HIGHS ARE EXPECTED TO BE IN THE MID TO UPPER 70S, WITH SOME LOCATIONS MAKING A RUN AT 80 DEGREES. NO PRECIP IS ANTICIPATED. THERE WILL BE SOME SCT CLOUDS ON AN OTHERWISE BEAUTIFUL DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... THE AREA OF HIGH PRES WILL MOVE EWD AND OFF THE CST AND A GENLY CLEAR SKY IS IN STORE WITH LIGHT WIND. && .LONG TERM /MONDAY THROUGH SATURDAY/... THE CENTER OF SURFACE HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC COAST ON MONDAY. SOUTHWESTERLY RETURN FLOW AROUND THE HIGH WILL DRAW EVEN WARMER AND MORE HUMID AIR UP THE EASTERN SEABOARD. MONDAY WILL CONTEND WITH APRIL 18TH FOR THE WARMEST DAY SO FAR THIS YEAR WITH HIGHS 80-85 DEGREES (EXCEPT COOLER ALONG THE COAST AND IN THE POCONOS). CONDITIONS ACROSS THE FORECAST AREA WILL BE DRY THROUGH MONDAY NIGHT OWING TO STRONG SUBSIDENCE PRESENT BENEATH THE H8 RIDGE. A COLD FRONT WILL MOVE SLOWLY SOUTHWARD THROUGH THE AREA TUESDAY AFTERNOON AND NIGHT. CLOUDS OVERSPREADING NORTHEAST PA AND NORTHWEST NJ WILL RESULT IN SLIGHTLY COOLER HIGHS IN THE 70S ON TUESDAY. FARTHER SOUTH IN THE WARM SECTOR, HIGHS TUESDAY HAVE THE POTENTIAL TO BE CLOSE TO MONDAY`S FROM ABOUT PHILLY SOUTHWARD IF THE FRONT AND ITS ASSOCIATED CLOUD COVER HANGS BACK TO THE NORTH. MOISTURE WILL POOL ALONG THE FRONT AS NOTED BY PWATS INCREASING TO NEAR 1.5 INCHES AND SURFACE DEWPOINTS TO NEAR 60F BY THE AFTERNOON. BUFKIT SOUNDINGS FROM THE 00Z GFS AND 21Z SREF SHOW MODEST INSTABILITY (ML CAPE AROUND 500 J/KG) WHILE THE 00Z NAM DEPICTS A CONSIDERABLY MORE UNSTABLE ENVIRONMENT (ML CAPE AOA 1000 J/KG). WENT MORE CONSERVATIVE WITH FORECAST COVERAGE OF THUNDERSTORMS DUE TO THE PRESENCE OF WEAK SHEAR AND LIMITED FORCING IN ADDITION TO THE QUESTIONABLE INSTABILITY. A GENERAL WEAKENING TREND IS EXPECTED WITH THE CONVECTION AFTER SUNSET, ALTHOUGH SHOWERS MAY LINGER INTO THE OVERNIGHT AS SLIGHTLY BETTER LIFT ASSOCIATED WITH AN UPPER SHORTWAVE TROUGH ARRIVES LATE. THE FRONT MAY EITHER CONTINUE TO SAG SOUTHWARD SLOWLY OR EVEN STALL OVER THE DELMARVA WEDNESDAY MORNING. LIFT ASSOCIATED WITH THE FRONT ITSELF SHOULD WEAKEN AS THE BOUNDARY IS EXPECTED TO BECOME INCREASINGLY DIFFUSE. CONSEQUENTIALLY, COVERAGE OF SHOWERS EXPECTED TO BE RELATIVELY LOW ON WEDNESDAY. THUNDERSTORM CHANCES CONFINED TO THE LOWER DELMARVA, WHERE THESE LOCATIONS HAVE THE BEST CHANCE OF RESIDING IN THE WARM SECTOR TO THE SOUTH OF THE BOUNDARY. THE CAA BEHIND THE FRONT IS NOT SIGNIFICANT, SO THE TREND OF ABOVE NORMAL TEMPS SHOULD CONTINUE INTO WEDNESDAY. HOWEVER, WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF ONSHORE FLOW TO DEVELOP. THIS MAY PREVENT TEMPS FROM REACHING 70F IN THE COASTAL PLAIN, ESPECIALLY THE EASTERLY WIND BECOMES ENHANCED BY A SEABREEZE. EXPANSIVE HIGH PRESSURE OVER THE EASTERN SEABOARD WILL PROVIDE A MAINLY DRY PATTERN THURSDAY THROUGH SATURDAY. THE HUMIDITY IS FORECAST TO INCREASE A BIT FRIDAY AND SATURDAY AS SOUTHERLY RETURN FLOW DEVELOPS WITH THE SURFACE HIGH MOVING OFFSHORE. CANNOT RULE OUT THE POSSIBILITY OF A A SHOWER DEVELOPING DURING THE AFTERNOON HOURS FRIDAY AND SATURDAY BUT THE SUBSIDENCE INVERSION UNDERNEATH THE RIDGE SHOULD MINIMIZE THE CONVECTIVE POTENTIAL. ABOVE NORMAL TEMPS WILL PERSIST WITH HIGHS IN THE 70S TO NEAR 80F EACH DAY. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. VFR CONDS WILL PREVAIL THRU THE TAF PD WITH HIGH PRES TO THE SE TODAY MOVG OFFSHORE TONIGHT. THE FLOW WILL BECOME SWLY BY AFTN BUT WILL BE LESS THAN 10 KTS. ONLY SCT CLOUDS ARE ANTICIPATED. WITH LIGHT FLOW, STILL EXPECTING ANOTHER SEA BREEZE AT KACY AND KMIV. AT THESE LOCATIONS, WIND COULD REACH 10 KT OR SO. OUTLOOK... MONDAY AND MONDAY NIGHT...VFR. SWLY MAY GUST TO 20 KT LATE IN THE DAY. TUESDAY AND TUESDAY NIGHT...PREDOMINATELY VFR. SCT SHRA AND ISO TSRA DURING THE AFTERNOON AND NIGHT COULD YIELD LOCAL MVFR/IFR CONDITIONS. WEDNESDAY...SHRA MAY LINGER INTO WEDNESDAY BUT MOST OF THE TERMINALS SHOULD DRY OUT. SOME MODEL SOLUTIONS ARE INDICATING EASTERLY WINDS TO DEVELOP. WILL HAVE TO WATCH FOR LOW CLOUDS AND MVFR CIGS TO ACCOMPANY MARINE LAYER. WEDNESDAY NIGHT AND THURSDAY...VFR. && .MARINE... DOGGEDLY PERSISTENT 5 FOOT SEAS NOW HAVE MADE IT INTO ALL OF OUR MARINE ZONES. WE HAVE EXTENDED THE SCA THROUGH ALL OUR WATERS FOR THIS MORNING. SINCE WINDS ARE NOW WELL BELOW SCA THRESHOLD FOR WINDS, WE CONVERTED THE SCA OVER TO HAZARDOUS SEAS ALL OCEAN ZONES. ONCE THIS SCA COMES DOWN, NO ADDITIONAL FLAGS ARE EXPECTED DURG THE REMAINDER OF THE NR AND SHORT TERM PDS. OUTLOOK... MONDAY THROUGH THURSDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA. THE STRONGEST WINDS ARE EXPECTED MONDAY AND TUESDAY AS HIGH PRESSURE MOVES OFFSHORE AND A S-SW FLOW AROUND 15-20 KT ENSUES. && .FIRE WEATHER... RELATIVE HUMIDITY VALUES NEAR 30 PERCENT, ALONG WITH OCCASIONAL WIND GUSTS TO NEAR 20 MPH MAY ENHANCE THE FIRE WEATHER RISK LATE IN THE DAY ON MONDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM EDT THIS MORNING FOR ANZ450>455. && $$ SYNOPSIS...KLEIN NEAR TERM...GIGI/NIERENBERG SHORT TERM...NIERENBERG LONG TERM...KLEIN AVIATION...KLEIN/NIERENBERG MARINE...GIGI/KLEIN/NIERENBERG FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MIAMI FL
954 AM EDT SUN MAY 3 2015 .UPDATE... THE CURRENT MODEL ANALYSIS SHOWS MOSTLY ZONAL FLOW ACROSS THE FLORIDA PENINSULA WITH A VERY WEAK MID LEVEL TROUGH OVER SOUTH FLORIDA. AT THE SURFACE, A BROAD AREA OF HIGH PRESSURE EXISTS ACROSS THE SOUTHEAST STATES CENTERED FROM WEST VIRGINIA TO NORTHERN GEORGIA. THE MID LEVEL TROUGH IS REFLECTED WELL ON THE 12Z MFL SOUNDING SHOWING A NORTH-NORTHEAST WIND IN THE LAYER FROM 600MB TO 450MB WITH WESTERLY FLOW ABOVE AND BELOW THAT. LOW LEVEL FLOW IS EAST-NORTHEAST WITH THE HIGH PRESSURE CENTERED TO THE NORTH. THE SURFACE HIGH WILL RAPIDLY SHIFT EAST TODAY IN RESPONSE TO A COLD FRONT THAT WILL MOVE INTO THE CENTRAL PORTION OF THE CONTINENTAL U.S. WITH THE PRESSURE GRADIENT TIGHTENING ACROSS SOUTH FLORIDA BY EARLY THIS AFTERNOON. THIS WILL KEEP THE HIGH RISK OF RIP CURRENTS AT THE ATLANTIC BEACHES WITH MIAMI BEACH OCEAN RESCUE ALREADY REPORTING STRONG CURRENTS THIS MORNING. THE 12Z SOUNDING ALSO SHOWS A VERY STABLE AIRMASS LAYER BETWEEN 850MB AND 750MB SO THIS WILL CONTINUE TO KEEP RAIN CHANCES OUT OF THE FORECAST ALTHOUGH THE HRRR IS INDICATING THE POSSIBILITY OF A COUPLE OF QUICK PASSING SHOWERS. HOWEVER, IT IS ONLY DEPICTING 20-25 DBZ INTENSITY SO NOT WORTH MENTIONING AT THIS TIME AND THE HRRR OFTEN TIMES OVER EMPHASIZES SHOWERS IN A DRY EASTERLY FLOW REGIME. BUT STILL, SOMETHING TO MONITOR. FOR THE MARINE FORECAST, DO NOT PLAN ANY CHANGES AT THIS TIME. HOWEVER, THE LATEST GFS MODEL GUIDANCE IS SHOWING A TAD BIT STRONGER WINDS OVER THE ATLANTIC WATERS THIS AFTERNOON THAN IS CURRENTLY DEPICTED. DUE TO THIS BEING FROM THE INTERMEDIATE RUN AT 06Z AND ONLY ONE UPDATE SHOWING THIS, WILL WAIT FOR THE 12Z RUN TO MAKE ANY DECISIONS BUT MAY NEED TO BUMP UP THE WIND TO 20 KNOTS FROM THE CURRENT 15-20 KNOTS WHICH COULD AFFECT THE SIGNIFICANT WAVE HEIGHTS AS WELL AND MAY NEED TO BEGIN THE SCA FOR THOSE WATERS EARLIER THAN THE 00Z START NOW. KOB && .PREV DISCUSSION... /ISSUED 744 AM EDT SUN MAY 3 2015/ AVIATION... MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EARLY MORNING HOURS AND THROUGH THE AFTERNOON WITH MAINLY STABLE WEATHER CONDITIONS ANTICIPATED. AS HIGH PRESSURE BUILDS...EAST NORTHEAST WINDS FORECAST TO INCREASE TO THE 15 TO 20 KNOTS RANGE BY LATE MORNING WITH HIGHER GUSTS POSSIBLE AND SUBSIDING OVERNIGHT BUT STILL REMAINING AROUND 10-15 KTS EXCEPT AROUND 10 KNOTS AT APF AND TMB. PREV DISCUSSION... /ISSUED 433 AM EDT SUN MAY 3 2015/ DISCUSSION... THE REGIONAL SYNOPTIC FEATURES EARLY THIS MORNING INCLUDE A WEAK SURFACE TROUGH JUST WEST OF THE KEYS AND EXTENDING NORTHWARD...A MID TO UPPER LEVEL TROUGH EXTENDING INTO THE CENTRAL TO EASTERN GULF AND A COLD FRONT ACROSS EASTERN CUBA THAT EXTENDS NORTHWARD TO A SURFACE LOW NORTHEAST OF THE MID-ATLANTIC STATES. FOR TODAY...HIGH PRESSURE WILL SLOWLY DEVELOP OFF THE GEORGIA/CAROLINAS COAST WITH THE AFOREMENTIONED SURFACE TROUGH ERODING. IN ADDITION DEEPER LAYERED MOISTURE WILL LIKELY REMAIN ACROSS THE KEYS TODAY. WITH HIGHER PRESSURE BUILDING INTO THE REGION THE WEST COAST SEA BREEZE WILL BE SUPPRESSED AND WITH PWAT EXPECTED TO BE AROUND ONLY AN INCH CONVECTION IS NOT LIKELY TODAY ALTHOUGH SOME ISOLATED SHOWER ACTIVITY IS POSSIBLE ACROSS THE SOUTHERN TIP OF THE PENINSULA. THERE WILL BE A HIGH RISK OF RIP CURRENTS ALONG THE ATLANTIC COAST BEACHES TODAY AND TONIGHT WITH A LONG PERIOD NORTHEASTERLY SWELL IN THE 2 TO 4 FOOT RANGE FORECAST TO ENTER THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY THIS MORNING...WITH THE GREATEST IMPACT EXPECTED ACROSS THE WATERS TO THE EAST OF PALM BEACH COUNTY. FOR MONDAY...MOISTURE AND CLOUDINESS WILL BEGIN TO RETURN TO THE REGION. THE MID TO UPPER LEVEL TROUGH ACROSS THE GULF IS FORECAST TO DEEPEN WITH THE FLORIDA PENINSULA TO THE EAST OF THE TROUGH AXIS. THE LOW LEVEL FLOW WILL BECOME SOUTHERLY BRINGING DEEP MOISTURE ACROSS CUBA NORTHWARD INTO THE REGION. MODERATE EASTERLY WINDS WILL FAVOR SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS MAINLY ALONG THE EASTERN THIRD OF THE PENINSULA AND THE ADJACENT ATLANTIC WATERS. FOR TUESDAY...PREVIOUS DISCUSSIONS HAVE ALREADY INDICATED THAT DEEP TROPICAL MOISTURE IS FORECAST TO ENTER ON TUESDAY WITH THE MID TO UPPER LEVEL TROUGH AXIS JUST WEST OF FLORIDA AND A BROAD LOW LEVEL TROUGH DEVELOPING ACROSS THE FLORIDA STRAITS AND EXTENDING INTO THE NORTHWEST BAHAMAS. THE PWAT IS FORECAST TO BE ABOUT 1.7 INCHES AND MID LEVEL TEMPERATURES FORECAST TO BE SIGNIFICANTLY COOL FOR THIS TIME OF YEAR...ABOUT 3 DEGREES COOLER. ALL THESE FACTORS ARE FORECAST TO BRING SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS TO THE REGION ON TUESDAY WITH A SYNOPTIC PATTERN SUPPORTIVE OF LOCALLY HEAVY RAINFALL WITH FLOODING POTENTIAL POSSIBLE IN ISOLATED AREAS. BY WEDNESDAY THE GLOBAL MODELS START TO DIVERGE SOME IN THEIR SOLUTIONS BUT THE GFS ENSEMBLE SHOWS BROAD FEATURES THAT SEEM LIKE A GENERAL CONSENSUS BETWEEN THE GFS AND THE ECMWF. THE ENSEMBLE INDICATES THAT THE UPPER LEVEL TROUGH AXIS IS FORECAST TO SHIFT EAST ACROSS THE FLORIDA PENINSULA WITH A BROAD LOW LEVEL AND SURFACE TROUGH OFF THE EAST CENTRAL FLORIDA COAST WITH DEEP MOISTURE EXTENDING ACROSS SOUTH FLORIDA. SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST WITH A SYNOPTIC PATTERN AGAIN SUPPORTIVE OF LOCALLY HEAVY RAINFALL. FOR THE EXTENDED FORECAST...BY THURSDAY THE ECMWF...GFS AND THE GFS ENSEMBLE HAVE BROAD AGREEMENT THAT THE UPPER LEVEL TROUGH WILL PERSIST NEAR THE FLORIDA PENINSULA WITH A CLOSED SURFACE LOW FORECAST OFF THE NORTHEAST FLORIDA COAST. THE GUIDANCE GENERALLY SUGGESTS THAT THE LOW COULD SLOWLY DRIFT TO THE NORTHWEST INTO NEXT WEEKEND. OBVIOUSLY ITS TOO EARLY TO SPECULATE ON THIS SCENARIO AND WHAT IF ANY IMPACT IT MIGHT HAVE FOR SOUTH FLORIDA AND WILL HAVE TO WAIT AND SEE WHAT CONSENSUS THE GUIDANCE HAS DURING THIS WEEK. MARINE... A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GULF WATERS FOR WINDS TO NEAR 20 KNOTS OR JUST ABOVE THROUGH 10 AM. WINDS ARE FORECAST TO SLOWLY DECREASE TODAY THEN INCREASE AGAIN TO 20 KNOTS OR JUST ABOVE MAINLY ACROSS THE OFF SHORE WATERS. THEREFORE THE SMALL CRAFT ADVISORY WILL BE ALLOWED TO EXPIRE THIS MORNING BUT A NEW ONE WILL BE ISSUED FOR TONIGHT...STARTING AT 00Z FOR THE OFF SHORE GULF WATERS. WITH THE COMBINATION OF NORTHEASTERLY WINDS IN THE 15 TO 20 KNOT RANGE ACROSS THE ATLANTIC WATERS AND A LONG PERIOD NORTHEASTERLY SWELL IN THE 2 TO 4 FOOT RANGE FORECAST TO ENTER THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY LATER THIS MORNING...HAZARDOUS SEAS TO NEAR 7 FEET ARE FORECAST ACROSS THE ATLANTIC WATERS WITH A SMALL CRAFT ADVISORY IN EFFECT TODAY STARTING AT 18Z THROUGH 00Z TUESDAY BUT MAY HAVE TO BE EXTENDED WITH LATER GUIDANCE. THERE IS A LOT OF UNCERTAINTY IN THE EXTENDED FORECAST GIVEN THE UNCERTAINTIES OUTLINED IN THE DISCUSSION ABOVE. SO THERE COULD BE CONSIDERABLE CHANGES TO THE WIND AND WAVES FORECAST IN THE EXTENDED PERIODS IN THE NEXT FEW DAYS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 79 69 82 73 / 10 0 20 60 FORT LAUDERDALE 80 71 82 73 / 10 10 20 70 MIAMI 81 70 82 72 / 10 10 20 70 NAPLES 87 63 86 67 / 10 10 10 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR FLZ168-172-173. AM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM EDT THIS MORNING FOR AMZ651-671. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 2 PM THIS AFTERNOON TO 8 PM EDT MONDAY FOR AMZ650-651-670-671. GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 AM EDT THIS MORNING FOR GMZ656-657-676. SMALL CRAFT ADVISORY FOR WINDS FROM 8 PM THIS EVENING TO 8 AM EDT MONDAY FOR GMZ676. && $$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1044 AM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 1045 AM CDT SUN MAY 3 2015 FORECAST WAS UPDATED TWICE THIS MORNING TO ADDRESS THE SMALL CHANCES OF SHOWERS AND ISOLATED THUNDERSTORMS OVER NORTHERN COUNTIES TODAY AND HANDLING CLOUD COVER. HAVE 20% CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON MAINLY NW OF I-55 WITH 30% CHANCE FAR NORTHERN COUNTIES OF KNOX, STARK AND MARSHALL COUNTIES. SCATTERED SHOWERS OVER SE IA INTO NW IL JUST NW OF ILX CWA WAS TRACKING ENE AHEAD OF ANOTHER WEAK SHORT WAVE OVER CENTRAL IA THAT WILL WEAKEN A LIFT INTO NE IL THIS AFTERNOON KEEPING BETTER CHANCES OF CONVECTION NORTH OF CENTRAL IL REST OF TODAY. IL RIVER VALLEY WILL BE ON SOUTHERN EDGE OF THIS WEATHER SYSTEM TO HAVE SMALL CHANCES OF CONVECTION THERE. TEMPS AT 1030 AM HAVE WARMED INTO THE UPPER 60S TO MID 70S AND WARM HIGHS IN THE LOWER 80S EXPECTED BY 4 PM TODAY ACROSS MUCH OF THE AREA. BREEZY SOUTHWEST WINDS OF 15 TO 25 MPH AND PARTLY TO MOSTLY SUNNY SKIES. && .SHORT TERM...(TODAY) ISSUED AT 338 AM CDT SUN MAY 3 2015 SURFACE TROUGH AND FRONTAL BOUNDARY REMAIN WELL OFF TO THE NORTHWEST THIS MORNING...DRAPED FROM SD NORTHEAST THROUGH MN. THIS WILL BECOME THE FOCUS FOR CONVECTIVE ACTIVITY LATER TODAY AS IT MOVES CLOSER TO CENTRAL IL IN THE LATE AFTERNOON. THIS MORNING A SHORTWAVE EVIDENT ON WATER VAPOR IMAGERY OVER CENTRAL IL CONTINUES TO PRODUCE A FEW SHOWERS...EXPECTED TO MOVE EASTWARD AND DISSIPATE LATER THIS MORNING IN EAST CENTRAL IL ACCORDING TO LATEST HRRR RUN. ANOTHER SHORTWAVE OVER WEST IA IS EXPECTED TO TRACK ENE AND PASS BY THE CENTRAL IL FORECAST AREA TO THE NORTH. WITH GENERAL SUBSIDENCE INDICATED ACROSS THE AREA...HAVE KEPT THE FORECAST DRY LATE MORNING THROUGH LATE AFTERNOON/EARLY EVENING ONCE THE INITIAL ROUND OF MORNING SHOWERS PASSES THROUGH. LOW LEVEL SOUTHERLY FLOW WILL KEEP THE WARMING TREND GOING FOR TODAY WITH HIGHS REACHING AROUND 80 DEGREES. FORECAST SOUNDINGS INDICATE BOUNDARY LAYER MOMENTUM CAPABLE OF PRODUCING GUSTS 20-25 MPH FROM I-70 NORTHWARD...WITH SUSTAINED SOUTHERLY WINDS 12-18 MPH. .LONG TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 338 AM CDT SUN MAY 3 2015 NOT A LOT OF CHANGES IN THE FORECAST. MAJORITY OF FORECAST REVOLVES AROUND A SLOWING/STALLED FRONTAL BOUNDARY ACROSS THE REGION FOR TONIGHT AND THROUGH TOMORROW BEFORE BEING EDGED TO THE NORTH BEFORE ANOTHER SYSTEM SPINS UP OVER THE PLAINS AND MOVES INTO THE REGION. FOR TONIGHT, THE FRONTAL BOUNDARY SETTLING IN JUST TO THE NORTHWEST WILL PROVIDE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS FOR THE AREA...SETTLING INTO THE NORTHERN HALF OF THE STATE AND BECOMING HUNG UP IN QUASI ZONAL FLOW ALOFT. BEST CHANCES FOR PRECIP REMAIN IN THE NORTHERN HALF OF THE STATE PROVIDING SOME FOCUS FOR STORM DEVELOPMENT. MODELS HAVE TRENDED A LITTLE MORE SCATTERED IN THE QPF FIELDS, ALTHOUGH THE NORTHERN HALF OF THE STATE STILL SEEMS PRIMED FOR THE BEST CHANCES OF PRECIP THROUGH MONDAY NIGHT, SPECIFICALLY THE AREAS WHERE THE BOUNDARY STALLS. SPC HAS KEPT THE NORTHERN HALF OF THE CWA IN A MARGINAL RISK FOR STORMS INVOF THE BOUNDARY ON MONDAY. CLUSTERS OF STORMS NEAR A WEAK BOUNDARY LOOKING BORDERLINE AT THIS POINT, BUT IN AN AREA OF CONTINUING WARM AIR ADVECTION PROVIDING POTENTIAL INSTABILITY JUST SOUTH OF THE BOUNDARY THAT WILL SLOWLY BE SETTLING SOUTH INTO THE WARMER AND MORE BUOYANT AIR. A RIDGE BEGINS TO BUILD INTO THE MIDWEST FROM THE SOUTHEAST...WITH ENOUGH SUBSIDENCE IN THE REGION OF THE RIDGE AXIS TO ERODE SHOWER CHANCES AT LEAST TUES NIGHT THROUGH WED NIGHT. ANOTHER PATTERN SHIFT TAKES HOLD FOR THE LATER HALF OF THE WEEK, SETTING UP MORE OF A SOUTHWESTERLY FLOW AND AN ACTIVE WEATHER PATTERN AGAIN AS WAVES CONTINUE TO RIPPLE AROUND THE SWRN LOW AND INTO THE MIDWEST. A RATHER WET FORECAST OVERALL, WITH SEVERAL DIFFERENT PATTERNS ESTABLISHING THEMSELVES...AND KEEPING SHOWERS AND THUNDERSTORMS IN THE OUTLOOK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 656 AM CDT SUN MAY 3 2015 VFR CONDITIONS AND LIGHT SOUTHERLY WINDS ACROSS CENTRAL IL THIS MORNING WITH ISOLATED -SHRA THROUGH MORNING. PARTIAL CLEARING EXPECTED LATE MORNING THROUGH AFTERNOON WITH SSW WINDS INCREASING TO AROUND 15 KTS WITH GUSTS 20-25 KTS. A FRONTAL BOUNDARY APPROACHING FROM THE NORTHWEST OVERNIGHT EXPECTED TO SPREAD SCT SHRA/ISOLD TSRA INTO CENTRAL IL AFTER 00Z. INCLUDED LOWER VFR CEILINGS AND VCSH IN TAFS FROM KSPI-KBMI NORTHWESTWARD BEFORE 12Z...HOWEVER KDEC-KCMI SOUTHEASTWARD NOT LIKELY TO BE AFFECTED BEFORE 12Z. ISOLD MVFR CIGS/VSBYS POSSIBLE WITH STRONGER STORMS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...ONTON LONG TERM...HJS AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
656 AM CDT SUN MAY 3 2015 .SHORT TERM...(TODAY) ISSUED AT 338 AM CDT SUN MAY 3 2015 SURFACE TROUGH AND FRONTAL BOUNDARY REMAIN WELL OFF TO THE NORTHWEST THIS MORNING...DRAPED FROM SD NORTHEAST THROUGH MN. THIS WILL BECOME THE FOCUS FOR CONVECTIVE ACTIVITY LATER TODAY AS IT MOVES CLOSER TO CENTRAL IL IN THE LATE AFTERNOON. THIS MORNING A SHORTWAVE EVIDENT ON WATER VAPOR IMAGERY OVER CENTRAL IL CONTINUES TO PRODUCE A FEW SHOWERS...EXPECTED TO MOVE EASTWARD AND DISSIPATE LATER THIS MORNING IN EAST CENTRAL IL ACCORDING TO LATEST HRRR RUN. ANOTHER SHORTWAVE OVER WEST IA IS EXPECTED TO TRACK ENE AND PASS BY THE CENTRAL IL FORECAST AREA TO THE NORTH. WITH GENERAL SUBSIDENCE INDICATED ACROSS THE AREA...HAVE KEPT THE FORECAST DRY LATE MORNING THROUGH LATE AFTERNOON/EARLY EVENING ONCE THE INITIAL ROUND OF MORNING SHOWERS PASSES THROUGH. LOW LEVEL SOUTHERLY FLOW WILL KEEP THE WARMING TREND GOING FOR TODAY WITH HIGHS REACHING AROUND 80 DEGREES. FORECAST SOUNDINGS INDICATE BOUNDARY LAYER MOMENTUM CAPABLE OF PRODUCING GUSTS 20-25 MPH FROM I-70 NORTHWARD...WITH SUSTAINED SOUTHERLY WINDS 12-18 MPH. .LONG TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 338 AM CDT SUN MAY 3 2015 NOT A LOT OF CHANGES IN THE FORECAST. MAJORITY OF FORECAST REVOLVES AROUND A SLOWING/STALLED FRONTAL BOUNDARY ACROSS THE REGION FOR TONIGHT AND THROUGH TOMORROW BEFORE BEING EDGED TO THE NORTH BEFORE ANOTHER SYSTEM SPINS UP OVER THE PLAINS AND MOVES INTO THE REGION. FOR TONIGHT, THE FRONTAL BOUNDARY SETTLING IN JUST TO THE NORTHWEST WILL PROVIDE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS FOR THE AREA...SETTLING INTO THE NORTHERN HALF OF THE STATE AND BECOMING HUNG UP IN QUASI ZONAL FLOW ALOFT. BEST CHANCES FOR PRECIP REMAIN IN THE NORTHERN HALF OF THE STATE PROVIDING SOME FOCUS FOR STORM DEVELOPMENT. MODELS HAVE TRENDED A LITTLE MORE SCATTERED IN THE QPF FIELDS, ALTHOUGH THE NORTHERN HALF OF THE STATE STILL SEEMS PRIMED FOR THE BEST CHANCES OF PRECIP THROUGH MONDAY NIGHT, SPECIFICALLY THE AREAS WHERE THE BOUNDARY STALLS. SPC HAS KEPT THE NORTHERN HALF OF THE CWA IN A MARGINAL RISK FOR STORMS INVOF THE BOUNDARY ON MONDAY. CLUSTERS OF STORMS NEAR A WEAK BOUNDARY LOOKING BORDERLINE AT THIS POINT, BUT IN AN AREA OF CONTINUING WARM AIR ADVECTION PROVIDING POTENTIAL INSTABILITY JUST SOUTH OF THE BOUNDARY THAT WILL SLOWLY BE SETTLING SOUTH INTO THE WARMER AND MORE BUOYANT AIR. A RIDGE BEGINS TO BUILD INTO THE MIDWEST FROM THE SOUTHEAST...WITH ENOUGH SUBSIDENCE IN THE REGION OF THE RIDGE AXIS TO ERODE SHOWER CHANCES AT LEAST TUES NIGHT THROUGH WED NIGHT. ANOTHER PATTERN SHIFT TAKES HOLD FOR THE LATER HALF OF THE WEEK, SETTING UP MORE OF A SOUTHWESTERLY FLOW AND AN ACTIVE WEATHER PATTERN AGAIN AS WAVES CONTINUE TO RIPPLE AROUND THE SWRN LOW AND INTO THE MIDWEST. A RATHER WET FORECAST OVERALL, WITH SEVERAL DIFFERENT PATTERNS ESTABLISHING THEMSELVES...AND KEEPING SHOWERS AND THUNDERSTORMS IN THE OUTLOOK. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 656 AM CDT SUN MAY 3 2015 VFR CONDITIONS AND LIGHT SOUTHERLY WINDS ACROSS CENTRAL IL THIS MORNING WITH ISOLATED -SHRA THROUGH MORNING. PARTIAL CLEARING EXPECTED LATE MORNING THROUGH AFTERNOON WITH SSW WINDS INCREASING TO AROUND 15 KTS WITH GUSTS 20-25 KTS. A FRONTAL BOUNDARY APPROACHING FROM THE NORTHWEST OVERNIGHT EXPECTED TO SPREAD SCT SHRA/ISOLD TSRA INTO CENTRAL IL AFTER 00Z. INCLUDED LOWER VFR CEILINGS AND VCSH IN TAFS FROM KSPI-KBMI NORTHWESTWARD BEFORE 12Z...HOWEVER KDEC-KCMI SOUTHEASTWARD NOT LIKELY TO BE AFFECTED BEFORE 12Z. ISOLD MVFR CIGS/VSBYS POSSIBLE WITH STRONGER STORMS. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...ONTON LONG TERM...HJS AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS TOPEKA KS
638 AM CDT Sun May 3 2015 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 346 AM CDT SUN MAY 3 2015 Isolated thunderstorms developed this morning shortly after 06Z in warm/moist advection within the low level jet. Vad wind profiles as well as water vapor imagery shows a mid level wave around 700 mb moving across central Kansas at 08Z. Latest runs of the HRRR and RAP move the isolated convection east into Missouri by 12Z-13Z. After this early morning round of convection, the rest of the day should be dry with clouds gradually decreasing through the early afternoon hours. Deep mixing today along with warm advection will yield highs in the low to mid 80s. Main thermal axis sets up from New Mexico through north central Kansas into northeast Nebraska today. Winds will increase by mid morning as pressure gradient increases. Surface front moves southeast into western Kansas this afternoon while it moves little across Nebraska. Expect afternoon heating out west will overcome convective inhibition for scattered storms to develop. These will remain to the west of north central Kansas into the early evening hours. Models eject weak waves northeast across western Kansas into southern Nebraska overnight. Expect convection to fire along the front in Nebraska tonight with outflow pushing south into north central and northeast Kansas. Southerly low level jet will help to develop scattered showers and thunderstorms overnight. Shear is marginal 20 to 30 kts overnight with MUCAPE 800-1000 J/kg. Expect some strong storms are possible with a few severe storms not out of the question later this evening across north central Kansas. Hail and winds will be the main hazards. Lows tonight will be mild with readings in the lower 60s. .LONG TERM...(Monday through Saturday) Issued at 346 AM CDT SUN MAY 3 2015 A wet pattern looks to be setting up for this upcoming week with several chances for precipitation all the way into next weekend. By Monday, a mid-level ridge will stretch across the Southern Plains and southeastern U.S. with a surface low centered over southwest Kansas. Models show the associated cold front extending into north central Kansas and southeast Nebraska, however the last few models runs have shown this front becoming fairly stationary over northern Kansas Monday into Monday night, limiting the southeastern extent of precipitation chances across the CWA. As a result, have continued to diminish PoPs across far east central Kansas through that period with likely PoPs along the KS/NE border with the stationary boundary. There continues to be the potential for some strong to severe thunderstorms to develop along this stationary boundary Monday afternoon into Monday evening as storms should be surface-based due to little to no inhibition present. The NAM continues to be the most aggressive with the amount of available moisture, thus increasing the parameters for severe thunderstorms. However, CAPE values could reach upwards of 1000-2000 J/kg with decent low-level lapse rates. However, 0-6km bulk shear continues to look fairly weak with most models showing upwards of only about 30kts. The main concern with any strong to severe storms will likely be some large hail and potentially some locally heavy rain as thunderstorms may train across north central Kansas into the evening and overnight hours with the low-level jet looking to be parallel to the boundary. The mid-level ridge should stretch further northward into the Central Plains Monday night into Tuesday, helping to push the cold front northward into Nebraska and further limiting the precipitation potential across the southeastern portions of the forecast area. At this time, Tuesday looks to show the best potential for being dry across much of the forecast area. However, focus quickly shifts to the southwest where a mid-level trough will be beginning to lift northeastward across the High Plains through Wednesday and into the Northern Plains by Wednesday night. At the surface, a low pressure system will strengthen across the High Plains but looks to become anchored over that region through mid to late week, resulting in persistent southerly surface winds advecting warm, moist air into the region. The combination of this steady stream of moisture and a frontal boundary that will likely remain hung up just west of the forecast area through much of the remainder of the week will help to support continued scattered shower and thunderstorm chances through the end of the week. While there is decent model agreement with the timing and tracking of the mid-level trough and the development of weak embedded waves within the pattern by late week, there is less agreement with the surface features in when the associated cold front will become tilted enough to move into the forecast area during the latter part of the week. Due to the low confidence in this boundary placement, have lowered PoPs some from the consensus blend but still have chance PoPs in for the entire forecast area through Saturday. This fairly stationary surface pattern should result in fairly similar temperatures throughout the week with highs in the 70s/near 80, lows in the upper 50s/low 60s, and dewpoints in the 50s and 60s. && .AVIATION...(For the 12Z TAFs through 12Z Monday Morning) Issued at 638 AM CDT SUN MAY 3 2015 Isolated shra and tsra are possible at TOP and FOE terminals through 14Z. VFR conditions are expected through the period outside of convective activity. South to southwest winds will increase to near 15 kts with gusts to 24kts from 14Z-00Z, then decrease to around 10 kts. TSRA may be possible at the terminals after 06Z. Confidence to low for timing at the terminals attm to go with more than VCTS. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...Hennecke AVIATION...53
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 AM CDT SUN MAY 3 2015 ...UPDATED AVIATION SECTION... .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 320 AM CDT SUN MAY 3 2015 THE MAIN CONCERN FOR THE SHORT TERM IS CONVECTIVE CHANCES, COVERAGE, AND STRENGTH FOR LATE THIS AFTERNOON INTO THE EVENING. ON THE SYNOPTIC SCALE, A RATHER WEAK WEST-TO-EAST FLOW WAS FOUND IN THE MID AND UPPER TROPOSPHERE, WITH 500MB FLOW AVERAGING ABOUT 15 TO 20 KNOTS ACROSS THE CENTRAL ROCKIES AND PLAINS WITH 250MB FLOW NOT MUCH STRONGER AT 25 TO 30 KNOTS. THIS IS MORE LIKE A LATE JUNE/EARLY JULY FLOW REGIME. AS A RESULT, THE CONVECTION THAT IS EXPECTED TO DEVELOP LATE THIS AFTERNOON WILL BEHAVE MORE LIKE LATE JUNE/JULY STORMS: SLOW MOVING, AND MARGINAL-AT-BEST SEVERE WEATHER PROSPECTS. THUNDERSTORMS WILL DEVELOP IN THE DEEPLY MIXED AIRMASS THAT WILL DEVELOP ALONG AND WEST OF THE LEE TROUGH AXIS/NEBULOUS DRYLINE. THE CONVERGENCE WILL NOT BE ALL THAT STRONG, BUT THE LOWER TO MID TROPOSPHERIC LAPSE RATES OF EARLY MAY WILL BE STEEP ENOUGH SUCH THAT EVEN WEAK CONVERGENCE WILL AID IN THUNDERSTORM DEVELOPMENT ALONG THE WEAK DRYLINE/LEE TROUGH. WHEN COMPARED AGAINST THE GFS, ECMWF, AND WRF-ARW, THE NAM12/NMMB SURFACE DEWPOINTS APPEAR TO BE TOO AMBITIOUS WITH MID 50S DEWPOINTS AS FAR WEST AS HIGHWAY 283 BY LATE AFTERNOON, RESULTING IN LARGE AREA OF 2000+ J/KG SBCAPE. THERE WILL LIKELY BE A BIT MORE MIXING THAN WHAT THE NAM12 SHOWS WITH TEMPERATURES WARMING WELL INTO THE MID TO UPPER 80S AND THE LACK OF ANY EASTERLY COMPONENT WIND. THAT SAID, THE EARLY RUNS OF THE RAP13 AND HRRR APPEAR TO BE WHACKED OUT WITH SURFACE FLOW TOO VEERED OUT/WESTERLY COMPONENT WITH DEWPOINTS TANKING INTO THE UPPER 30S TO AROUND 40F FOR ALL OF SOUTHWEST KANSAS. BELIEVE THAT SOMETHING IN THE MIDDLE IS MORE REALISTIC IN TERMS OF WHAT WILL REALLY PAN OUT WITH THE SURFACE SETUP LATE THIS AFTERNOON. NEVERTHELESS, 1000 TO 1500 J/KG SBCAPE SHOULD BE REALIZED AHEAD OF THE DEVELOPING CONVECTION THIS AFTERNOON. THE GREATEST THREAT FROM ANY OF THE STORMS WILL BE SOME LOCALIZED DOWNBURST WIND GUSTS IN EXCESS OF 50 KNOTS/58 MPH GIVEN THE ANTICIPATED HIGH TEMPERATURE- DEWPOINT SPREADS APPROACHING 40F LATE THIS AFTERNOON. THE HAIL RISK LOOKS QUITE LOW GIVEN THE POOR CAPE-SHEAR COMBINATION AND LACK OF ANY UPPER TROPOSPHERIC FLOW TO SUPPORT MID-UPPER STORM-RELATIVE SHEAR. THE STRONGEST STORM WILL STILL BE CAPABLE OF QUARTER TO PERHAPS HALF-DOLLAR SIZE HAIL, THOUGH. THE FORECAST POPS OF 40 TO 50 PERCENT WILL COVER AREAS ALONG AND BETWEEN THE HIGHWAY 83 AND 283 CORRIDOR, INCLUDING SCOTT CITY, GARDEN, LIBERAL, NESS CITY, WAKEENEY, AND HAYS. ANTICIPATED SLOW STORM MOTIONS WILL RESULT IN LOCALIZED HEAVY RAINFALL, ESPECIALLY DURING THE EVENING WHEN UPSCALE GROWTH OCCURS BETWEEN 00-03Z. LOSS OF DIURNAL HEATING WILL LIKELY RESULT IN THE DEMISE OF CONVECTION BY 06Z MUCH LIKE WE HAVE SEEN OVER THE PAST COUPLE NIGHTS OUT ALONG THE KS-CO BORDER. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 320 AM CDT SUN MAY 3 2015 AN UPPER LEVEL LOW IS EXPECTED TO MOVE INTO THE DESERT SOUTHWEST SUNDAY INTO MONDAY THEN WEAKEN INTO AN OPEN WAVE AND CURLS NORTHEASTWARD INTO THE CENTRAL ROCKIES BY TUESDAY INTO TUESDAY NIGHT. THIS FEATURE THEN MOVES INTO THE CENTRAL PLAINS WEDNESDAY THEN INTO THE NORTHERN PLAINS THURSDAY. MOISTURE ABOVE WESTERN KANSAS WILL INCREASE AS THIS FEATURE APPROACHES LEADING TO INCREASING CLOUDS MONDAY WITH MOSTLY CLOUDY SKIES EXPECTED MONDAY NIGHT THROUGH TUESDAY NIGHT. A FRONTAL BOUNDARY AT THE SURFACE IS ANTICIPATED TO SPRAWL OUT ACROSS WEST CENTRAL KANSAS MONDAY THEN SHIFT NORTHWARD MONDAY NIGHT INTO TUESDAY AS A WARM FRONT. WINDS AHEAD OF THIS BOUNDARY WILL GENERALLY BE FROM A SOUTHERLY DIRECTION WITH WINDS BEHIND THIS BOUNDARY FROM MORE OF A NORTHERLY DIRECTION. A DOME OF HIGH PRESSURE WILL BE LOCATED ACROSS THE EASTERN UNITED STATES WITH TRAJECTORIES ON THE WEST SIDE BRINGING UP COPIOUS AMOUNTS OF MOISTURE FROM THE GULF INTO THE CENTRAL PLAINS. AS FOR PRECIPITATION CHANCES, THUNDERSTORMS MAY BE POSSIBLE ACROSS CENTRAL KANSAS MONDAY MORNING BUT SHOULD QUICKLY MOVE OUT OF THE CWA BY LATE MORNING. ADDITIONAL THUNDERSTORMS ARE PROGGED TO DEVELOP ACROSS WESTERN KANSAS IN THE AFTERNOON AND SPREAD ACROSS THE REMAINDER OF THE AREA MONDAY NIGHT. A FEW STORMS COULD BECOME STRONG TO SEVERE ACROSS CENTRAL KANSAS DEPENDING ON HOW MUCH HEATING OCCURS DURING THE DAY. RAIN CHANCES BECOME LIKELY TUESDAY AS MOISTURE CONTINUES TO BE PULLED UP FROM THE GULF AND PWAT`S SURPASS AN INCH. MEANWHILE, AN UPPER LEVEL LOW ENTERS THE WESTERN UNITED STATES TUESDAY THEN SLIDES SOUTHWARD INTO THE DESERT SOUTHWEST BY THURSDAY. THIS LOW THEN CURLS NORTHEAST INTO THE CENTRAL ROCKIES FRIDAY THEN INTO THE NORTHERN ROCKIES WEEKEND. WEAK SHORTWAVES ARE EXPECTED TO MOVE AROUND THE PERIPHERY OF THIS SYSTEM AND TOWARDS THE CENTRAL PLAINS FOR THE REMAINDER OF THE WEEK. THIS WILL ALLOW PRECIPITATION CHANCES TO CONTINUE ACROSS THE AREA WITH THE BEST CHANCE OF BENEFICIAL RAINFALL ACROSS CENTRAL AND SOUTH CENTRAL KANSAS. AS FOR TEMPERATURES, HIGHS MONDAY LOOK TO RANGE FROM THE LOWER 70S ACROSS WEST CENTRAL KANSAS WHERE THE FRONTAL BOUNDARY WILL BE LOCATED TO LOWER 80S ACROSS SOUTH CENTRAL KANSAS. HIGHS TUESDAY ARE ANTICIPATED TO BE AROUND 70 DEGREES. LOWS MONDAY NIGHT AND TUESDAY NIGHT ARE PROGGED TO RANGE FROM AROUND 50 DEGREES ACROSS FAR WESTERN KANSAS TO AROUND 60 DEGREES ACROSS CENTRAL AND SOUTH CENTRAL KANSAS. HIGHS FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S WITH LOWS RANGING FROM AROUND 50 DEGREES ACROSS FAR WESTERN KANSAS TO AROUND 60 DEGREES ACROSS CENTRAL AND SOUTH CENTRAL KANSAS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 612 AM CDT SUN MAY 3 2015 A FRONTAL BOUNDARY WILL BIFURCATE THE AREA TODAY WITH SOUTHERLY WINDS FELT AHEAD OF THE FRONT WITH NORTHWESTERLY WINDS BEHIND THE FRONT. THE DDC TERMINAL LOOKS TO STAY AHEAD OF THE FRONT THROUGHOUT THE DAY WHERE AS THE GCK AND HYS TERMINALS LOOK TO BE VERY CLOSE TO THE FRONT THIS MORNING. THIS IS THE REASON FOR THE VRB CONDITIONS CURRENTLY IN THE TAFS. WINDS LOOK TO BE FROM A SOUTHERLY DIRECTION BY THIS AFTERNOON AS THE AFOREMENTIONED FRONT MOVES NORTH AS A WARM FRONT. VFR CONDITIONS WILL PREVAIL TODAY WITH SCATTERED HIGH CLOUDS THIS MORNING. THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS AROUND THE HYS TERMINAL THIS EVENING AND A PROB30 HAS BEEN ADDED TO ACCOUNT FOR THIS. && .PRELIMINARY POINT TEMPS/POPS... DDC 88 58 80 57 / 30 30 50 70 GCK 88 55 78 55 / 40 40 60 90 EHA 88 54 75 53 / 30 20 60 80 LBL 90 57 79 56 / 40 50 60 90 HYS 87 58 78 57 / 40 50 60 60 P28 86 60 81 59 / 10 20 20 40 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...UMSCHEID LONG TERM...HOVORKA_42 AVIATION...HOVORKA_42
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
740 AM EDT SUN MAY 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 505 AM EDT SUN MAY 3 2015 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION. UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50. A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR 10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND 1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS INTO THE MID TO UPPER 70S OVER THE WEST HALF. THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING. LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K- 10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER SOUTH. EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY 06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 AM EDT SUN MAY 3 2015 ABOVE AVERAGE TEMPS WITH GENERALLY DRY CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA THROUGH TUESDAY BEFORE OFF AND ON CHANCES OF SHOWERS AND THUNDERSTORMS CLOSE OUT THE WEEK. MONDAY AND TUESDAY...A SPLIT UPPER JET PATTERN WILL BE WELL IN PLACE TO BEGIN THE PERIOD...WITH A VERY BROAD MID-LEVEL TROUGH ACROSS THE UPPER MS VALLEY AND UPPER GREAT LAKES. THE COLD FRONT AND ASSOCIATED CONVECTION EXPECTED TO INFLUENCE THE CWA THIS AFTERNOON AND TONIGHT WILL CLEAR THE CWA BY 12Z MONDAY. WITH SFC HIGH PRESSURE SHIFTING ACROSS THE CWA AND A MID-LEVEL RIDGE BUILDING ACROSS THE NORTHERN PLAINS...DRY CONDITIONS ARE EXPECTED MONDAY THROUGH TUESDAY. TEMPS WILL BE COOLER THAN TODAY FOR BOTH MONDAY AND TUESDAY AS 850 HPA TEMPS FALL TO 3-7C. WITH A WNW WIND MON...TEMPS WILL BE CHILLY ACROSS PORTIONS OF THE LAKE SUPERIOR SHORELINE...ESPECIALLY EAST OF MARQUETTE. SOME HINTS AS LINGERING LOW-LEVEL MOISTURE OVER EASTERN LAKE SUPERIOR MAY ALSO RESULT IN SOME FOG ALONG THE SHORELINE THROUGH MOST OF MONDAY. TUESDAY NIGHT AND WEDNESDAY...A BROAD SFC LOW FORMING UNDER THE SOUTHERN UPPER JET AND A MID-LEVEL TROUGH OVER THE SW STATES WILL BEGIN TO LIFT INTO THE CENTRAL PLAINS BY THIS TIME. MEANWHILE...THE MID-LEVEL RIDGE ACROSS THE PLAINS AND MS VALLEY WILL CONTINUE TO BUILD WHILE DRIFTING EASTWARD. LOW-LEVEL WAA/ISENTROPIC LIFT WELL AHEAD OF THIS LOW IS EXPECTED ACROSS WI AND THE WEST AND CENTRAL CWA TUESDAY NIGHT INTO WEDNESDAY...AND SHOULD BE ENOUGH TO GENERATE LIGHT RAIN ALOFT. HOW MUCH REACHES THE GROUND REMAINS IN QUESTION AS THE LOW-LEVELS WILL BE QUITE DRY TUESDAY. BECAUSE OF THIS...ALL MODEL SOLUTIONS SHOW A RAPID DETERIORATION OF THE PRECIP AS IT MOVES OVER UPPER MI. HAVE OPTED TO KEEP ONLY LOW CHANCE POPS ALONG THE WI BORDER TUESDAY NIGHT...AND ACROSS MUCH OF WESTERN AND CENTRAL UPPER MI ON WEDNESDAY. THURSDAY THROUGH SATURDAY...THE SFC LOW OVER THE PLAINS WILL CONTINUE TO MEANDER TO THE NE AS THE ASSOCIATED MID-LEVEL WAVE ATTEMPTS TO ROUND THE RIDGE. WITH MINIMAL FORCING...MUCH OF THE AREA SHOULD REMAIN DRY WED NIGHT INTO THU MORNING. BY THE AFTERNOON...FORCING FROM THE APPROACHING MID-LEVEL SHORTWAVE WILL BE ENOUGH TO INDUCE SCATTERED SHOWERS AND POSSIBLY SOME THUNDERSTORMS ACROSS THE WEST HALF OF THE CWA. WITH THE WAVE AND SFC LOW LIFTING ACROSS THE ARROWHEAD OF MN AND NORTH OF LAKE SUPERIOR...SCATTERED SHOWERS AND STORMS ARE EXPECTED INTO FRIDAY MORNING. COVERAGE MAY INCREASE FRIDAY AFTERNOON AS THE SFC COLD FRONT BEGINS TO MOVE IN FROM THE WEST. OVERALL...DO NOT SEE ANY REASON TO GO WITH ANYTHING HIGHER THAN HIGH-END CHANCE POPS GIVEN THE OVERALL SCATTERED NATURE OF EXPECTED PRECIP. BY SATURDAY...THE SFC COLD FRONT WILL CLEAR THE AREA AS IT BEGINS TO STALL/WASH OUT OVER WI. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 740 AM EDT SUN MAY 3 2015 EXPECT VFR CONDITIONS THROUGH THIS MORNING AT ALL THE TAF SITES WITH RELATIVELY DRY AIRMASS ASSOCIATED WITH RETREATING HIGH PRES DOMINATING. DURING THE AFTERNOON...THE INTERACTION BETWEEN AN APPROACHING DISTURBANCE/COLD FRONT...INCREASING LOW LEVEL MOISTURE IN A GUSTY SW FLOW AHEAD OF THE FRONT AND DAYTIME HEATING/DESTABILIZATION WILL RESULT IN SOME SHRA AND TSRA. THERE IS STILL SOME UNCERTAINTY ON THE DEGREE OF LOW LEVEL MOISTENING/DESTABILIZATION...BUT DID INCLUDE A MENTION OF SOME TS AT SAW...WHICH IS MORE LIKELY TO SEE HIGHER INSTABILITY. MVFR CONDITIONS ARE LIKELY TO ACCOMPANY THE STRONGER SHRA/TS. ANY STRONGER TS COULD ALSO PRODUCE VERY GUSTY WINDS. LOOK FOR VFR CONDITIONS OVERNIGHT WITH DRYING BEHIND THE COLD FRONT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 505 AM EDT SUN MAY 3 2015 OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD. LOW PRESSURE OVER NW ONTARIO WILL LIFT NORTHEAST TO HUDSON BAY...DRAGGING A COLD FRONT ACROSS LAKE SUPERIOR LATE THIS AFTERNOON AND EVENING ALONG WITH A CHANCE OF THUNDERSTORMS...AND PATCHY TO AREAS OF FOG. LOOK FOR HIGH PRESSURE ACROSS NORTH DAKOTA TONIGHT TO BUILD ACROSS THE UPPER GREAT LAKES MONDAY...WITH DRIER AIR LIMITING ANY LINGERING FOG ACROSS LAKE SUPERIOR. THE HIGH WILL SLOWLY EXIT ACROSS THE LOWER GREAT LAKES WEDNESDAY NIGHT...IN RESPONSE TO A LOW NEARING FROM THE N AND CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY. THE CHANCE OF THUNDERSTORMS WILL ALSO RETURN WEDNESDAY AFTERNOON THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KLUBER AVIATION...JLB MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
700 AM CDT Sun May 3 2015 .SHORT TERM: (Today and Tonight) Issued at 325 AM CDT Sun May 3 2015 There is quite a bit of cloud cover early this morning across the region courtesy of two weak short waves in the westerly flow aloft. The first of these currently centered from northern IL into southeast MO has been generating some spotty high-based showers from the associated mid clouds/moisture. Present indications are this wave and the mid level moisture will continue to push east this morning with a few sprinkles still possible after 12z in south central IL. The other short wave is currently centered near the Nebraska/Iowa border into northeast KS and is more problematic. The associated convection has generated a sizeable cloud canopy which has not been resolved by the models and will overspread a good portion of the CWA this morning. Unclear is how it will evolve with time - i.e. thinning, but the RAP has this wave centered through far eastern IA at midday and the current thought is to have quite a bit of clouds the first half of this morning then thinning and moving east by midday into early afternoon. There are also suggestions in the RAP, ECMWF, and a few of the hi-res WRFs that the southwest stretching tail of this short wave could generate a few showers across northeast MO and west central IL this afternoon and early this evening. I have added a slight chance as a result. Otherwise a warm day is on tap with well above normal temperatures expected. While the morning clouds will hamper the temp rise a bit, increasing south-southwesterly low level flow and rising low- level temperatures should compensate and will result in highs in the upper 70s to mid 80s across the area. South-southwest lower trop flow will maintain a low-level warm advection region tonight and moisture will gradually be improving. The thermal and moisture advection combined with a plume of relatively steep mid level lapse rates will result in a swath of weak instability across northern parts of the CWA in advance of the southward sinking cold front. While the front will remain well north of the CWA at daybreak Monday, northwest steering flow will help push at least scattered showers and thunderstorms or thunderstorm clusters into northeast MO and west central IL late tonight. We could also see spotty WAA generated showers well in advance of the activity that has moved off the front, hence the low pops all the way down to St. Louis. Glass .LONG TERM: (Monday through Saturday) Issued at 325 AM CDT Sun May 3 2015 The west-east oriented cold front will ooze southward out of IA and northern IL into northern sections of the CWA by early Monday evening. Ongoing showers and thunderstorms at daybreak should dissipate by midday. Heating and continued low-level moistening in their wake will result in weak-moderate instability along the frontal zone and the combo of a migrating impulse and good low level convergence along the boundary should result in extensive convective development during the later half of the afternoon spanning from KS across northern MO/southern IA into central IL. A broad veering southwesterly LLJ will maintain numberous thunderstorms/clusters during the evening, with the activity shunting a bit northward overnight in response to increasing ridging aloft and a slight northward shift in the frontal zone. The front will continue to shift northward on Tuesday as ridging aloft continues to build from the lower TN Valley into the upper MS Valley. There are some suggestions of air mass type convection across southern portions of the CWA but I`m not sold on it and have kept pops in the slight range and confined the coverage. Otherwise Tuesday will be another day of above normal temps with highs in the 80s. This warmth will persist on Wednesday and even into Thursday with the chance of showers and thunderstorms slowly increasing west-east over the 2 day period as the ridging aloft shunts east and southwest flow aloft becomes more dominant with time. The greatest threat of showers and thunderstorms in the extended period will be Friday-Saturday with an active southwest flow aloft, moist unstable warm sector, and slowly encroaching cold front. Glass && .AVIATION: (For the 12z TAFs through 12z Monday Morning) Issued at 700 AM CDT Sun May 3 2015 VFR conditions to prevail through forecast period with just mid and high clouds. Low level wind shear to diminish by mid morning with winds mixing down to surface. Winds to pickup from the south to southwest and gust to around 20kts at times this afternoon before diminishing towards sunset. Some showers possible around KUIN but will be widely scattered so no mention for now. As for next system that will approach late tonight, did add vicinity shower mention at KUIN, dry elsewhere. Specifics for KSTL: VFR conditions to prevail through forecast period with just mid and high clouds. Low level wind shear to diminish by 14z Sunday with winds mixing down to surface. Winds to pickup from the south and gust to around 20kts at times this afternoon before diminishing after 01z Monday. As for next system that will approach late tonight, activity to remain north of metro area. Byrd && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
905 AM MDT SUN MAY 3 2015 .UPDATE... WEAK ECHOES ON RADAR FROM S OF KBIL THROUGH SE MT THIS MORNING WERE MAINLY MID CLOUDS PER SURFACE OBSERVATIONS...WITH POSSIBLE SPRINKLES. WEB CAMS SHOWED DRY CONDITIONS. SPRINKLES/MID CLOUDS WERE BEING INDUCED BY WEAK RIGHT-REAR JET QUADRANT UPPER DIVERGENCE WHICH WILL CONTINUE THROUGH THE EVENING FROM THE 90 KT JET TO THE N OF THE AREA. NEW WRF SHOWED MID-LEVEL FRONTOGENESIS OVER THE AREA OF RADAR ECHOES INTO THE AFTERNOON. CHANCE OF SPRINKLES WILL END BY 18Z AS FRONTOGENESIS MOVES OUT. ISENTROPIC LIFT INCREASES OVER WESTERN AREAS BY 00Z TONIGHT. TRIMMED BACK THE SPRINKLES TO BETTER FIT THE CURRENT RADAR ECHOES AND REMOVED POPS FROM THE NE BIGHORNS THIS MORNING. THE AFTERNOON POPS OVER THE MOUNTAINS WERE FINE AND NO MENTION OF THUNDER MADE SENSE GIVEN THE LOW CAPES ON THE SREF...AND RAP SOUNDINGS. TEMPERATURES AND DEWPOINTS LOOKED GOOD TODAY. ADJUSTED SKY COVER BASED ON CURRENT SATELLITE...AND WIND SPEEDS BASED ON LATEST GUIDANCE. KLVM TENDS TO BECOME GUSTY WITH AN E WIND. LOW-LEVEL SE FLOW INCREASES TONIGHT AND MON WHILE ISENTROPIC LIFT CONTINUES OVER THE AREA. POPS WERE IN GOOD SHAPE. ARTHUR && .SHORT TERM...VALID FOR TDY AND MON... QUIET END TO THE WEEKEND EXPECTED AS A WESTERLY FLOW ALOFT WILL CONTINUE OVER THE FORECAST AREA TODAY. SATELLITE SHOWING AN AREA OF CLOUDS ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE STATE WITH CLEARING JUST TO THE WEST OF OUR AREA. EXPECT THESE CLOUDS TO MOVE EAST ALLOWING FOR PARTLY SUNNY SKIES TO DEVELOP FROM WEST TO EAST TODAY. RADAR HAS BEEN SHOWING SOME RETURNS FROM ABOUT BIG HORN COUNTY EAST TO THE DAKOTAS. HOWEVER...BELIEVE MOST IF NOT ALL OF THIS IS VIRGA AS TEMPERATURE/DEWPOINT SPREADS ARE QUITE HIGH AND CLOUD BASES ARE AROUND 11K FEET. TEMPERATURES TODAY WILL BE A GOOD 10 DEGREES COOLER AS A RESULT OF THE FRONT THAT MOVED THROUGH LAST EVENING. MOST AREAS WILL SEE HIGHS IN THE 60S WHICH IS NORMAL FOR THIS TIME OF YEAR. AN UPPER LOW AND TROUGH APPROACH THE PACIFIC NORTHWEST COAST LATE IN THE DAY MONDAY. THIS WILL ALLOW THE FLOW TO BUCKLE SOMEWHAT RESULTING IN WEAK RIDGING BUILDING ACROSS OUR AREA...AS WELL AS A SOUTHWEST FLOW ALOFT. A WEAK DISTURBANCE WILL MOVE NORTHEAST OUT OF THE GREAT BASIN AREA DURING THE AFTERNOON AND EVENING BRINGING A SLIGHT SHOWER AND ISOLATED THUNDERSTORM CHANCE TO OUR FAR WESTERN AREAS WITH THE BEST CHANCES OVER THE ABSAROKA/BEARTOOTH AND BIG HORN MOUNTAINS AND ADJACENT FOOTHILLS. AS THE DISTURBANCE MOVES EAST...THE BETTER SHOWER CHANCES WILL SHIFT ACROSS OUR SOUTHEAST COUNTIES MONDAY NIGHT. TEMPERATURES MONDAY WILL WARM BACK TO ABOVE NORMAL WITH READINGS IN THE 70S...EXCEPT FOR SOME 60S OUT TOWARD THE DAKOTA BORDERS. HOOLEY .LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT... MODELS HAVE CONTINUED THE SAME GENERAL PATTERN IN THE LONG TERM...WETTER AND COOLER. TUESDAY THE LOW OVER THE PACIFIC WILL BEGIN TO MOVE ALONG THE COAST AS IT DIGS SOUTH. THIS WILL BRING MOIST SOUTHWEST FLOW INTO THE AREA. THE FLOW WILL GENERALLY BE UNSETTLED AS SEVERAL IMPULSES OF ENERGY MOVE THROUGH THE FLOW. THIS WILL GIVE THE AREA A SHOT AT RAIN...BUT MOSTLY IN THE MOUNTAINS. THE BEST CHANCES FOR RAIN WILL COME TOWARDS THE WEEKEND AS THE LOW IN THE GREAT BASIN LIFTS INTO WYOMING. THIS WILL BRING THE GREATEST ENERGY MOVING THROUGH COINCIDENT WITH SOME DECENT FORCING. THERE CONTINUES TO BE SOME TIMING AND PLACEMENT ISSUES BETWEEN THE MODELS WITH THE PRECIP...SO HAVE NOT GOTTEN TOO SPECIFIC. WITH THE INCREASED MOISTURE AND CLOUDINESS...CONTINUE TO EXPECT TEMPERATURES TO BE NEAR NORMAL...GENERALLY IN THE 60S FOR HIGHS. REIMER && .AVIATION... VFR CONDITIONS WILL CONTINUE TO PREVAIL OVER THE NEXT 24 HOURS. WINDS WILL GENERALLY BE LIGHT THROUGHOUT THE DAY. SOME SHOWERS WILL CONTINUE TO BE POSSIBLE IN THE MOUNTAINS WITH LOCALIZED MOUNTAIN OBSCURATION. REIMER/FRIEDERS && .PRELIMINARY POINT TEMP/POPS... TDY MON TUE WED THU FRI SAT ------------------------------------------------------- BIL 065 045/075 050/076 047/065 045/051 040/053 041/058 1/B 11/B 12/T 54/T 34/W 44/W 55/W LVM 066 038/074 043/075 041/062 039/047 035/049 036/059 2/W 12/T 23/T 55/T 45/W 44/W 55/W HDN 067 043/078 045/079 046/067 044/054 040/056 040/062 1/B 21/B 12/T 43/T 34/W 33/W 44/W MLS 066 045/073 049/076 050/067 044/059 041/060 042/060 0/B 11/N 11/B 44/T 33/W 33/W 34/W 4BQ 066 043/070 046/074 048/066 045/059 042/056 040/060 1/B 32/W 11/N 45/T 33/W 33/W 44/W BHK 064 039/067 045/070 047/064 043/058 038/057 038/056 1/B 12/W 11/N 46/T 33/W 22/W 34/W SHR 065 043/072 044/072 044/063 041/054 038/055 039/057 2/W 32/T 22/T 44/T 34/W 44/W 55/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...NONE. WY...NONE. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
924 AM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 924 AM CDT SUN MAY 3 2015 JUST UPDATED TO ADD A 2-3 HOUR WINDOW OF OPPORTUNITY FOR ISOLATED RAIN SHOWERS/WEAK THUNDERSTORMS TO SEVERAL COUNTIES MAINLY EAST OF AN OSBORNE-CLAY CENTER-OSCEOLA LINE THIS MORNING. ALTHOUGH FORCING IS SUBTLE...THIS RECENT UPTICK IN ELEVATED ACTIVITY APPEARS TO BE TIED TO A SUBTLE MID LEVEL PASSING THROUGH AND GENERATING "JUST ENOUGH" LOW-MID LEVEL THETA-E ADVECTION TO KICK THINGS OFF. ALTHOUGH MODELS HAVE STRUGGLED TO PICK UP ON THIS...WOULD BE SURPRISED TO SEE ANY OF THIS EASTERN ACTIVITY LINGER PAST THE 11AM-12PM HOUR...AS STILL EXPECT THE MAJORITY OF THE CWA TO REMAIN DRY THE MAJORITY OF THE DAY. AS FOR THE LATE AFTERNOON/EVENING/OVERNIGHT STORM CHANCES...UNFORTUNATELY...UNCERTAINTY MAY BE HIGHER IN THE NOW THAN IT WAS 24 HOURS AGO REGARDING HOW THIS PLAYS OUT. PER SOME MODELS...THE OVERALL SEVERE THREAT MAY BE A BIT LESS THAN THOUGHT 24 HOURS AGO...BUT THAT BEING SAID...GIVEN WHAT HAPPENED YESTERDAY WITH THE GREATER-THAN-EXPECTED COVERAGE OF STRONG- SEVERE STORMS IN THE NORTHEAST CWA...THIS PATTERN IS PRONE TO YIELDING SURPRISES. STAY TUNED FOR PLENTY MORE THOUGHTS/UPDATED THINKING WITH THE AFTERNOON DISCUSSION. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 433 AM CDT SUN MAY 3 2015 BIGGEST CHALLENGE WILL BE DETERMINING CHANCES AND TIMING OF SHOWERS/THUNDERSTORMS AS WELL AS THE POTENTIAL FOR STRONG STORMS. ANOTHER CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES FOR TODAY. SPLIT FLOW FOR TODAY...CAUGHT BETWEEN THE NORTH AND SOUTH STREAMS. LOCAL SYNOPTIC FLOW WILL BE ZONAL...BUT TURN MORE SOUTHWEST TONIGHT AS A NEGATIVELY TILTED BROAD UPPER LEVEL TROUGH ENTERS THE SOUTHWESTERN UNITED STATES. AT THE SURFACE...A COLD FRONT IS ON ITS WAY SOUTH ACROSS SOUTH DAKOTA. THE TIMING OF THIS FRONT SUGGESTS THAT WE WILL WARM UP SIGNIFICANTLY DUE TO COMPRESSIONAL WARMING. MODELS ARE GENERALLY NOT PICKING UP ON THIS WELL ENOUGH...SO I AM GOING OUT ON A BIT OF A LIMB AND GOING QUITE A BIT MORE THAN GENERAL GUIDANCE IN THE MID 80S. GOING FOR 91 FOR THE TRI-CITIES...FAVORING THE HI RES NMM SOLUTION. BELIEVE IT OR NOT...THIS WOULD BREAK OUR RECORD IN HASTINGS BY 2 DEGREES AND BE ONE DEGREE SHORT OF THE RECORD HIGH IN GRAND ISLAND. THE RAP MODEL BUMPS UP TEMPERATURES EVEN MORE IN NORTH CENTRAL KANSAS TO THE MID 90S. THESE WARMER TEMPERATURES WOULD HAVE PUT US IN THE REALM OF APPROACHING CRITICAL FIRE WEATHER ISSUES IF IT WERE NOT FOR THE FACT THAT WE HAVE GREENED UP. CHANCES OF PRECIPITATION ARE NOT CERTAIN. COVERAGE IS A BIT SPOTTY UNTIL THE CAP BREAKS IN THE EVENING. EVENT THEN...COVERAGE IS IN QUESTION...ESPECIALLY DEPENDING ON THE EXACT PLACEMENT OF THE FRONT WHEN STORMS FIRE. WE WILL PROBABLY NEED A HIGHER NARROW CORRIDOR OF CATEGORICAL CHANCES OF SHOWERS/THUNDERSTORMS...BUT AT THIS TIME...THAT IS VERY DIFFICULT TO DETERMINE...ESPECIALLY AS THE FRONT MAY TEMPORARILY STALL FOR A SHORT TIME TOWARD EVENING. A SECONDARY IMPULSE WITHIN MID-LEVEL FLOW COULD BOOST CHANCES OF RAIN OVERNIGHT...PROBABLY IN OUR SOUTH. I DO NOT GO OVER A 60 PERCENT CHANCE ANYWHERE IN THE CWA...AND HANG AROUND 40-50 PERCENT CHANCE FOR THE TRI-CITIES. AS FOR STRONG/SEVERE CHANCES...WE COULD GET SOME STRONG STORMS WITH MARGINAL INSTABILITY OF 500 TO 1500 J/KG AND LOW- LEVEL WIND SHEAR APPROACHING 30-35 IN OUR NORTH...BUT PROBABLY LOWER IN MOST OF THE REST OF THE CWA. THIS COULD BE ENOUGH TO GIVE US SOME STRONG STORMS WITH NICKEL SIZE HAIL AND PERHAPS A STRONG WIND GUST...BUT THE BETTER SUPPORT FOR SEVERE WEATHER LOOKS LIKE IT SHOULD BE EAST/NORTHEAST OF THE CWA. WENT WITH SIMILAR LOWS FOR TONIGHT COMPARED TO THE PREVIOUS FORECAST AND STUCK WITH SUPERBLEND IN THE 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 433 AM CDT SUN MAY 3 2015 PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND THE MULTIPLE CHANCES FOR THUNDERSTORMS THROUGH THE ENTIRE PERIOD. THE UNSETTLED WEATHER PATTERN HAS SETTLED IN ACROSS THE REGION BY THE START OF THE PERIOD MON/MON NIGHT...WITH MODELS SHOWING THE AREA UNDER SOUTHWESTERLY FLOW ALOFT...WITH THE PARENT LOW PRESSURE OVER SRN CALIFORNIA AND WEAK RIDGING EXTENDING NORTH FROM THE GULF COAST INTO PORTIONS OF THE MIDWEST. MAY HAVE SOME LINGERING PRECIP ACROSS THE AREA DURING THE MORNING HOURS FROM OVERNIGHT ACTIVITY...BUT WOULD THINK THERE WOULD BE A LULL AT SOME POINT. HARD TO PINPOINT EXACTLY WHERE THAT LINGERING ACTIVITY MAY BE...SO HAVE CHANCE POPS ACROSS THE ENTIRE CWA. AT THE SFC...MODELS CONTINUE TO BE IN PRETTY GOOD AGREEMENT SHOWING THE PLACEMENT OF THE MAIN SFC FRONT OVER SRN PORTIONS OF THE CWA NEAR THE NEB/KS STATE LINE...WITH SOME SHOWING A LOW PLACED IN CLOSE PROXIMITY TO THE S/SWRN CORNER OF THE CWA. THE PLACEMENT OF THE SFC FRONT...UNCERTAINTY WITH THE AMOUNT OF SKY COVER /LIKELY HIGH/ AND ANY LINGERING PRECIP MAKES THE HIGH TEMP FORECAST TRICKY. MUCH OF SC NEB IS LOOKING AT ERLY WINDS NORTH OF THE FRONT...WITH MORE SRLY WINDS ACROSS NC KS. FORECAST HIGH TEMP IS A BLEND...AND COULD SEE CLOSE TO A 20 DEGREE GRADIENT ACROSS THE CWA /SOME MODELS ARE MORE DRASTIC/...WITH ARND 60 IN THE NORTH TO NEAR 80 IN THE FAR SOUTH. DURING THE AFTERNOON HOURS AND INTO THE EVENING/OVERNIGHT...THIS FRONTAL BOUNDARY WILL BE A FOCUS FOR ADDITIONAL THUNDERSTORM DEVELOPMENT AS YET ANOTHER DISTURBANCE MAKES ITS WAY INTO THE REGION...AIDED ALSO BY AN INCREASING LLJ. SEVERE WEATHER REMAINS A CONCERN WITH MODEST INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR...LARGE HAIL/DAMAGING WINDS REMAIN THE PRIMARY CONCERNS...BUT WILL HAVE TO MONITOR THE POTENTIAL FOR AN ISOLATED TORNADO WITH THOSE MORE ERLY WINDS/INCREASED LOW LEVEL SHEAR IN THE AREA. SPC DAY 2 OUTLOOK SLIGHT RISK AREA INCLUDES ROUGHLY THE SERN HALF OF THE CWA. SIMILAR TO MONDAY...TUESDAY MORNING MAY HAVE SOME LINGERING ACTIVITY FROM OVERNIGHT...BUT MODELS SUGGEST THE OVERALL COVERAGE MAY NOT BE AS WIDESPREAD. THE MAIN UPPER LEVEL LOW HAS SHIFTED EAST INTO THE FOUR CORNERS REGION BY TUESDAY MORNING...AND MODELS CONTINUE TO SHOW THE POTENTIAL FOR THE LOW TO WEAKEN SOME/FILL...AS IT COMES UNDER INCREASING INFLUENCE OF A STRONGER UPPER LEVEL LOW MOVING INTO THE PAC NW REGION. AT THE SFC...DURING THE DAYTIME HOURS...THE FRONTAL BOUNDARY CONTINUING TO MEANDER AROUND CENTRAL PORTIONS OF THE CWA LOOKS TO PUSH NORTH AS A WARM FRONT...WITH MOST MODELS SHOWING SRLY WINDS IN PLACE ACROSS THE ENTIRE CWA DURING THE AFTERNOON. MODELS CONTINUE TO SHOW THE BETTER THUNDERSTORMS CHANCES ACROSS WRN PORTIONS OF THE CWA DURING THE AFTERNOON...SPREADING ACROSS THE REST OF THE CWA OVERNIGHT AS LIFT CONTINUES TO INCREASE WITH THE APPROACHING MAIN UPPER TROUGH/LOW...WHICH IS STARTING TO MAKE MORE OF A PUSH ONTO THE THE PLAINS DURING THE LATE TUES NIGHT HOURS/WED MORNING. WED/WED NIGHT CONTINUES TO BE THE PERIOD GENERALLY SHOWN BY MODELS WHEN THAT MAIN TROUGH AXIS /CLOSED LOW?/ MAKES ITS TREK NE THROUGH THE REGION...AS THAT STRONGER UPPER LEVEL LOW DIGS FURTHER SOUTH ALONG THE WEST COAST. THE HIGH CHANCE/LOW END LIKELY POPS CONTINUE IN THE FORECAST...SIMILAR TO PERIODS PRIOR AND FOLLOWING...HARD TO TRIM AREAS OUT OR RAISE POPS IN OTHERS WHEN SO MANY DETAILS HAVE YET TO BE IRONED OUT. THE LOCATION OF THE SFC LOW/ASSOCIATED BOUNDARIES LOOK TO BE PLAYING A BIGGER ROLE/FOCUS FOR CONVECTIVE DEVELOPMENT NEAR/ACROSS THE CWA...SO AS THEIR ULTIMATE PLACEMENT BECOMES MORE CLEAR IN THE COMING MODEL RUNS...CAN PIN DOWN BETTER DETAILS WITH POPS AND SEVERE WEATHER POTENTIAL. THROUGH THE REST OF THE LONG TERM PERIOD THURSDAY THROUGH SATURDAY...ONE NOTABLE DISTURBANCE MOVES OUT...BUT SOUTHWESTERLY FLOW REMAINS IN PLACE IN THE UPPER LEVEL AS THAT NEXT LOW PRESSURE SYSTEM CONTINUES TO DIG FURTHER SOUTH INTO CALIFORNIA. PIECES OF SHORTWAVE ENERGY ASSOCIATED WITH THAT LOW LOOK TO CONTINUE TO BRING AT LEAST PERIODIC THUNDERSTORM CHANCES...KEPT THE FORECAST CLOSE TO THE CR INIT/SUPERBLEND OUTPUT. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 541 AM CDT SUN MAY 3 2015 WIND WILL BE PRIMARILY OUT OF THE SOUTH BEFORE A COLD FRONT MOVES IN BY THIS EVENING...AND SHIFTS TO THE NORTH...WHEN SHOWERS/THUNDERSTORMS WILL BE POSSIBLE. TIMING OF ANY THUNDERSTORMS IS SO UNCERTAIN...THAT A RATHER GENERAL VCTS WAS INCLUDED FOR 00Z AND BEYOND. && .CLIMATE... ISSUED AT 433 AM CDT SUN MAY 3 2015 PREDICTED HIGH TODAY: HASTINGS 91 GRAND ISLAND 91 RECORD HIGH: HASTINGS 89 (1959) GRAND ISLAND 92 (1959) && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...PFANNKUCH SHORT TERM...HEINLEIN LONG TERM...ADP AVIATION...HEINLEIN CLIMATE...HEINLEIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
637 AM CDT SUN MAY 3 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 320 AM CDT SUN MAY 3 2015 TODAY...STORMS SHOULD CONTINUE EASTWARD OUT OF THE FORECAST AREA EARLY THIS MORNING. HIGH RES MODELS ARE IN GOOD AGREEMENT WITH THAT. STORMS LAST EVENING DID PRODUCE SOME LARGE HAIL AND A FEW SPOTS RECEIVED STRONG WINDS AS STORMS MIXED DOWN A STRONG LOW LEVEL JET. AS OF AROUND 07Z RUC MODEL INITIALIZATION SHOWED WINDS AT AROUND 1 KM AGL OF AROUND 40-50 KNOTS STRETCHING FROM WESTERN OKLAHOMA INTO SOUTHEAST NEBRASKA AND PARTS OF IOWA. THESE WINDS WILL DECREASE THIS MORNING. COLD FRONT AS OF 08Z STRETCHED FROM NORTHEAST MINNESOTA BACK INTO WESTERN SOUTH DAKOTA. THAT FRONT WILL MOVE SOUTHEAST INTO NORTHEAST NEBRASKA THIS AFTERNOON. LOOK FOR HIGHS IN THE MID TO UPPER 80S AT MOST SPOTS TODAY WITH A FEW HIGHS AROUND 90 POSSIBLE. THIS WILL CREATE CAPE VALUES FROM 1500 TO 2500 J/KG BY MID AFTERNOON. EXPECT CAP TO BREAK NEAR THE FRONT BY MID/LATE AFTERNOON. SOME MODELS ALSO HINT AT THE CAP WEAKENING FARTHER SOUTH...BUT WITH A LACK OF FOCUS AT THAT TIME WILL KEEP HIGHEST POPS CLOSER TO THE FRONT. SOME SEVERE STORMS APPEAR POSSIBLE...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS. GENERALLY USED A BLEND OF SHORT RANGE GUIDANCE FOR TONIGHT WITH THE HIGHEST WEIGHT GIVEN TO THE 00Z HIGH RES WRF-ARW MODEL. LIKE SOME OF THE OTHER MODELS...IT DEVELOPED STORMS LATE AFTERNOON THEN MOVED THEM SOUTH AND EAST. SOME STORMS MAY CONTINUE TO BE SEVERE IN THE EVENING. COVERAGE SHOULD DECREASE AFTER MIDNIGHT. CONVECTION WILL LIKELY FORCE THE FRONT DOWN AT LEAST AS FAR AS SOUTHEAST NEBRASKA AND MAYBE INTO NORTHEAST KANSAS BY 12Z MONDAY. MOST MODELS SHOW LIFT OCCURRING OVER THE BOUNDARY DURING THE DAY MONDAY WITH PCPN COVERAGE INCREASING...SO HAVE POPS INCREASING TO MATCH THAT. TWO CLUSTERS OF STORMS MAY TAKE SHAPE BY LATE AFTERNOON OR EARLY EVENING. ONE NEAR THE NEBRASKA/SOUTH DAKOTA BORDER AND ANOTHER LIFTING FROM NORTHERN KANSAS THROUGH OUR AREA AND TOWARD CENTRAL IOWA MONDAY NIGHT. TUESDAY...WE MAY SEE SOMEWHAT OF A BREAK IN THE WIDESPREAD PCPN... AT LEAST OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. HAVE POPS RANGING FROM 15 TO 50 PERCENT...HIGHEST IN NORTHEAST NEBRASKA. SOUTHERLY FLOW WILL INCREASE AND HELP A WARM FRONT LIFT NORTH OF THE AREA. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 320 AM CDT SUN MAY 3 2015 PATTERN WILL BE ACTIVE MUCH OF THIS PERIOD. A LARGE MID TROPOSPHERIC TROUGH SHOULD BE OVER THE WESTERN UNITED STATES AT THE START OF THIS PERIOD WITH EMBEDDED SHORTWAVES. ONE OF THESE WAVES WILL LIFT ACROSS MID AMERICA WEDNESDAY/WEDNESDAY NIGHT...WHILE A CLOSED LOW STARTS TO DIG SOUTHWARD FROM THE PACIFIC NORTHWEST. THIS WILL GENERALLY KEEP OUR AREA IN SOUTHWEST FLOW WITH A DECENT SUPPLY OF LOW LEVEL MOISTURE FOR SHOWERS AND STORMS TO WORK WITH. MODEL AGREEMENT STARTS TO FALL OFF BY DAY 7...SO CONFIDENCE FALLS TO AVERAGE BY DAY 7. TEMPERATURES AND PCPN SHOULD BE AT OR ABOVE NORMAL FOR THIS PERIOD. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 637 AM CDT SUN MAY 3 2015 A COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA THIS AFTERNOON AND EARLY EVENING. LOOK FOR GUSTY SOUTH WINDS AHEAD OF THE FRONT. SHOWERS AND THUNDERSTORMS SHOULD DEVELOP THIS EVENING AND CONTINUE INTO THE EARLY OVERNIGHT HOURS. A LOT OF LOW-LEVEL MOISTURE IS FORECAST TO REMAIN BEHIND TODAY`S FRONT...THUS HAVE KEPT MVFR CEILINGS IN THE FORECAST THROUGH 12Z MONDAY. WITH SEVERAL WEATHER SYSTEMS EXPECTED TO MOVE THROUGH THIS COMING WEEK EXPECT UNSETTLED WEATHER TO CONTINUE OFF AND ON THROUGH THE WORK WEEK. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...PEARSON/MILLER LONG TERM...MILLER AVIATION...PEARSON
AREA FORECAST DISCUSSION
NWS HASTINGS NE
543 AM CDT SUN MAY 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 433 AM CDT SUN MAY 3 2015 BIGGEST CHALLENGE WILL BE DETERMINING CHANCES AND TIMING OF SHOWERS/THUNDERSTORMS AS WELL AS THE POTENTIAL FOR STRONG STORMS. ANOTHER CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES FOR TODAY. SPLIT FLOW FOR TODAY...CAUGHT BETWEEN THE NORTH AND SOUTH STREAMS. LOCAL SYNOPTIC FLOW WILL BE ZONAL...BUT TURN MORE SOUTHWEST TONIGHT AS A NEGATIVELY TILTED BROAD UPPER LEVEL TROUGH ENTERS THE SOUTHWESTERN UNITED STATES. AT THE SURFACE...A COLD FRONT IS ON ITS WAY SOUTH ACROSS SOUTH DAKOTA. THE TIMING OF THIS FRONT SUGGESTS THAT WE WILL WARM UP SIGNIFICANTLY DUE TO COMPRESSIONAL WARMING. MODELS ARE GENERALLY NOT PICKING UP ON THIS WELL ENOUGH...SO I AM GOING OUT ON A BIT OF A LIMB AND GOING QUITE A BIT MORE THAN GENERAL GUIDANCE IN THE MID 80S. GOING FOR 91 FOR THE TRI-CITIES...FAVORING THE HI RES NMM SOLUTION. BELIEVE IT OR NOT...THIS WOULD BREAK OUR RECORD IN HASTINGS BY 2 DEGREES AND BE ONE DEGREE SHORT OF THE RECORD HIGH IN GRAND ISLAND. THE RAP MODEL BUMPS UP TEMPERATURES EVEN MORE IN NORTH CENTRAL KANSAS TO THE MID 90S. THESE WARMER TEMPERATURES WOULD HAVE PUT US IN THE REALM OF APPROACHING CRITICAL FIRE WEATHER ISSUES IF IT WERE NOT FOR THE FACT THAT WE HAVE GREENED UP. CHANCES OF PRECIPITATION ARE NOT CERTAIN. COVERAGE IS A BIT SPOTTY UNTIL THE CAP BREAKS IN THE EVENING. EVENT THEN...COVERAGE IS IN QUESTION...ESPECIALLY DEPENDING ON THE EXACT PLACEMENT OF THE FRONT WHEN STORMS FIRE. WE WILL PROBABLY NEED A HIGHER NARROW CORRIDOR OF CATEGORICAL CHANCES OF SHOWERS/THUNDERSTORMS...BUT AT THIS TIME...THAT IS VERY DIFFICULT TO DETERMINE...ESPECIALLY AS THE FRONT MAY TEMPORARILY STALL FOR A SHORT TIME TOWARD EVENING. A SECONDARY IMPULSE WITHIN MID-LEVEL FLOW COULD BOOST CHANCES OF RAIN OVERNIGHT...PROBABLY IN OUR SOUTH. I DO NOT GO OVER A 60 PERCENT CHANCE ANYWHERE IN THE CWA...AND HANG AROUND 40-50 PERCENT CHANCE FOR THE TRI-CITIES. AS FOR STRONG/SEVERE CHANCES...WE COULD GET SOME STRONG STORMS WITH MARGINAL INSTABILITY OF 500 TO 1500 J/KG AND LOW- LEVEL WIND SHEAR APPROACHING 30-35 IN OUR NORTH...BUT PROBABLY LOWER IN MOST OF THE REST OF THE CWA. THIS COULD BE ENOUGH TO GIVE US SOME STRONG STORMS WITH NICKEL SIZE HAIL AND PERHAPS A STRONG WIND GUST...BUT THE BETTER SUPPORT FOR SEVERE WEATHER LOOKS LIKE IT SHOULD BE EAST/NORTHEAST OF THE CWA. WENT WITH SIMILAR LOWS FOR TONIGHT COMPARED TO THE PREVIOUS FORECAST AND STUCK WITH SUPERBLEND IN THE 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 433 AM CDT SUN MAY 3 2015 PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND THE MULTIPLE CHANCES FOR THUNDERSTORMS THROUGH THE ENTIRE PERIOD. THE UNSETTLED WEATHER PATTERN HAS SETTLED IN ACROSS THE REGION BY THE START OF THE PERIOD MON/MON NIGHT...WITH MODELS SHOWING THE AREA UNDER SOUTHWESTERLY FLOW ALOFT...WITH THE PARENT LOW PRESSURE OVER SRN CALIFORNIA AND WEAK RIDGING EXTENDING NORTH FROM THE GULF COAST INTO PORTIONS OF THE MIDWEST. MAY HAVE SOME LINGERING PRECIP ACROSS THE AREA DURING THE MORNING HOURS FROM OVERNIGHT ACTIVITY...BUT WOULD THINK THERE WOULD BE A LULL AT SOME POINT. HARD TO PINPOINT EXACTLY WHERE THAT LINGERING ACTIVITY MAY BE...SO HAVE CHANCE POPS ACROSS THE ENTIRE CWA. AT THE SFC...MODELS CONTINUE TO BE IN PRETTY GOOD AGREEMENT SHOWING THE PLACEMENT OF THE MAIN SFC FRONT OVER SRN PORTIONS OF THE CWA NEAR THE NEB/KS STATE LINE...WITH SOME SHOWING A LOW PLACED IN CLOSE PROXIMITY TO THE S/SWRN CORNER OF THE CWA. THE PLACEMENT OF THE SFC FRONT...UNCERTAINTY WITH THE AMOUNT OF SKY COVER /LIKELY HIGH/ AND ANY LINGERING PRECIP MAKES THE HIGH TEMP FORECAST TRICKY. MUCH OF SC NEB IS LOOKING AT ERLY WINDS NORTH OF THE FRONT...WITH MORE SRLY WINDS ACROSS NC KS. FORECAST HIGH TEMP IS A BLEND...AND COULD SEE CLOSE TO A 20 DEGREE GRADIENT ACROSS THE CWA /SOME MODELS ARE MORE DRASTIC/...WITH ARND 60 IN THE NORTH TO NEAR 80 IN THE FAR SOUTH. DURING THE AFTERNOON HOURS AND INTO THE EVENING/OVERNIGHT...THIS FRONTAL BOUNDARY WILL BE A FOCUS FOR ADDITIONAL THUNDERSTORM DEVELOPMENT AS YET ANOTHER DISTURBANCE MAKES ITS WAY INTO THE REGION...AIDED ALSO BY AN INCREASING LLJ. SEVERE WEATHER REMAINS A CONCERN WITH MODEST INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR...LARGE HAIL/DAMAGING WINDS REMAIN THE PRIMARY CONCERNS...BUT WILL HAVE TO MONITOR THE POTENTIAL FOR AN ISOLATED TORNADO WITH THOSE MORE ERLY WINDS/INCREASED LOW LEVEL SHEAR IN THE AREA. SPC DAY 2 OUTLOOK SLIGHT RISK AREA INCLUDES ROUGHLY THE SERN HALF OF THE CWA. SIMILAR TO MONDAY...TUESDAY MORNING MAY HAVE SOME LINGERING ACTIVITY FROM OVERNIGHT...BUT MODELS SUGGEST THE OVERALL COVERAGE MAY NOT BE AS WIDESPREAD. THE MAIN UPPER LEVEL LOW HAS SHIFTED EAST INTO THE FOUR CORNERS REGION BY TUESDAY MORNING...AND MODELS CONTINUE TO SHOW THE POTENTIAL FOR THE LOW TO WEAKEN SOME/FILL...AS IT COMES UNDER INCREASING INFLUENCE OF A STRONGER UPPER LEVEL LOW MOVING INTO THE PAC NW REGION. AT THE SFC...DURING THE DAYTIME HOURS...THE FRONTAL BOUNDARY CONTINUING TO MEANDER AROUND CENTRAL PORTIONS OF THE CWA LOOKS TO PUSH NORTH AS A WARM FRONT...WITH MOST MODELS SHOWING SRLY WINDS IN PLACE ACROSS THE ENTIRE CWA DURING THE AFTERNOON. MODELS CONTINUE TO SHOW THE BETTER THUNDERSTORMS CHANCES ACROSS WRN PORTIONS OF THE CWA DURING THE AFTERNOON...SPREADING ACROSS THE REST OF THE CWA OVERNIGHT AS LIFT CONTINUES TO INCREASE WITH THE APPROACHING MAIN UPPER TROUGH/LOW...WHICH IS STARTING TO MAKE MORE OF A PUSH ONTO THE THE PLAINS DURING THE LATE TUES NIGHT HOURS/WED MORNING. WED/WED NIGHT CONTINUES TO BE THE PERIOD GENERALLY SHOWN BY MODELS WHEN THAT MAIN TROUGH AXIS /CLOSED LOW?/ MAKES ITS TREK NE THROUGH THE REGION...AS THAT STRONGER UPPER LEVEL LOW DIGS FURTHER SOUTH ALONG THE WEST COAST. THE HIGH CHANCE/LOW END LIKELY POPS CONTINUE IN THE FORECAST...SIMILAR TO PERIODS PRIOR AND FOLLOWING...HARD TO TRIM AREAS OUT OR RAISE POPS IN OTHERS WHEN SO MANY DETAILS HAVE YET TO BE IRONED OUT. THE LOCATION OF THE SFC LOW/ASSOCIATED BOUNDARIES LOOK TO BE PLAYING A BIGGER ROLE/FOCUS FOR CONVECTIVE DEVELOPMENT NEAR/ACROSS THE CWA...SO AS THEIR ULTIMATE PLACEMENT BECOMES MORE CLEAR IN THE COMING MODEL RUNS...CAN PIN DOWN BETTER DETAILS WITH POPS AND SEVERE WEATHER POTENTIAL. THROUGH THE REST OF THE LONG TERM PERIOD THURSDAY THROUGH SATURDAY...ONE NOTABLE DISTURBANCE MOVES OUT...BUT SOUTHWESTERLY FLOW REMAINS IN PLACE IN THE UPPER LEVEL AS THAT NEXT LOW PRESSURE SYSTEM CONTINUES TO DIG FURTHER SOUTH INTO CALIFORNIA. PIECES OF SHORTWAVE ENERGY ASSOCIATED WITH THAT LOW LOOK TO CONTINUE TO BRING AT LEAST PERIODIC THUNDERSTORM CHANCES...KEPT THE FORECAST CLOSE TO THE CR INIT/SUPERBLEND OUTPUT. && .AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 541 AM CDT SUN MAY 3 2015 WIND WILL BE PRIMARILY OUT OF THE SOUTH BEFORE A COLD FRONT MOVES IN BY THIS EVENING...AND SHIFTS TO THE NORTH...WHEN SHOWERS/THUNDERSTORMS WILL BE POSSIBLE. TIMING OF ANY THUNDERSTORMS IS SO UNCERTAIN...THAT A RATHER GENERAL VCTS WAS INCLUDED FOR 00Z AND BEYOND. && .CLIMATE... ISSUED AT 433 AM CDT SUN MAY 3 2015 PREDICTED HIGH TODAY: HASTINGS 91 GRAND ISLAND 91 RECORD HIGH: HASTINGS 89 (1959) GRAND ISLAND 92 (1959) && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...HEINLEIN LONG TERM...ADP AVIATION...HEINLEIN CLIMATE...HEINLEIN
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
543 AM MDT SUN MAY 3 2015 .AVIATION... 12Z TAF CYCLE ISO-SCT SHRA/TSRA WILL DEVELOP AROUND OR JUST AFTER 18Z TODAY. SIMILAR STORM COVERAGE AS YDAY THOUGH SLIGHTLY MORE WIDESPREAD ACROSS THE EAST. STORM MOTION WILL BE TOWARD THE EAST AROUND 10KTS. BASED ON HRRR OUTPUT...ANY TAF SITE MAY BE IMPACTED... ESPECIALLY WITH GUSTY OUTFLOW WINDS UP TO 40KTS. THE STRONGER STORMS WILL ALSO BE CAPABLE OF PEA SIZE HAIL AND BRIEF MVFR CIGS/VSBYS. STORMS WILL LARGELY DISSIPATE AFTER SUNSET. 34 && .PREV DISCUSSION...335 AM MDT SUN MAY 3 2015... .SYNOPSIS... SLIGHTLY COOLER TODAY WEST AND CENTRAL BUT HIGHS OVERALL REMAINING ABOVE AVERAGE BEFORE FALLING TO BELOW AVERAGE MONDAY THROUGH THURSDAY. ISOLATED TO SCATTERED SHOWERS AND STORMS WILL DEVELOP AGAIN TODAY OVER THE HIGHER TERRAIN AND TRACK INTO THE VALLEYS AND PLAINS. A SLOW MOVING STORM SYSTEM WILL BRING WIDESPREAD SHOWERS AND STORMS MONDAY THROUGH TUESDAY NIGHT. HEAVY RAIN WILL BE POSSIBLE FROM THE CENTRAL MOUNTAIN CHAIN TO THE TEXAS BORDER...AND POTENTIAL EXISTS FOR A FEW STRONG TO SEVERE THUNDERSTORMS TO DEVELOP BOTH MONDAY AND TUESDAY FROM THE PECOS VALLEY TO THE TEXAS BORDER...MAINLY OVER DE BACA...CHAVES...CURRY AND ROOSEVELT COUNTIES. DRIER AND BREEZY TO WINDY WEATHER IS FORECAST FOR LATE IN THE WEEK. && .DISCUSSION... SPOTTY SHOWERS AND ISOLD STORMS PERSISTING SOUTH OF I-40 EARLY THIS MORNING...AND EXPECTING ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS AND STORMS TODAY...DEVELOPING OVER THE HIGHER TERRAIN AND MOVING INTO THE LOWER ELEVATIONS THIS AFTERNOON/EVENING. HIGHS CENTRAL AND WEST SLIDE A FEW MORE DEGREES BEFORE COOLING DOWN BELOW AVERAGE OVER THE ENTIRE FORECAST AREA MONDAY AND TUESDAY. A WIDESPREAD PRECIPITATION EVENT IS LOOKING MORE LIKELY FOR NORTHERN AND CENTRAL NM MONDAY THROUGH TUESDAY NIGHT. HEAVY RAIN WILL BE POSSIBLE FOR THE EASTERN PLAINS...WHERE SIGNIFICANT AMOUNTS COULD RESULT IN POTENTIAL FOR AT LEAST LOCALIZED FLOODING...ESPECIALLY ALONG AND EAST OF THE PECOS. COORDINATED WITH MAF ON POSSIBLE FLASH FLOOD WATCH...WILL LEAVE THAT DECISION TO SUCCEEDING SHIFTS...BUT NEW QPF AMOUNTS UPWARDS OF 2 INCHES MONDAY-TUESDAY NIGHT EAST OF THE PECOS. IN ADDITION...SPC DAY 2 AND 3 CONVECTIVE OUTLOOKS PUT THE EASTERN PLAINS IN A MARGINAL AREA...WITH SLIGHT RISK FOR SEVERE STORMS FOCUSED OVER DE BACA...CHAVES...ROOSEVELT AND CURRY COUNTIES BOTH MONDAY AND TUESDAY. GFS IS TRENDING A BIT DRIER EARLIER...TUESDAY NIGHT...THAN IT HAD BEEN...BUT BY WEDNESDAY THE UPPER TROUGH WILL BE EXITING AND THE FOCUS FOR ANY CONVECTION SHOULD BE OVER THE NORTHWEST THIRD AND PERHAPS ALONG THE EASTERN BORDER WITH TX. THEREAFTER...A LARGE AREA OF LOW PRESSURE ALOFT WILL DEVELOP OVER THE GREAT BASIN...BUT NEW MEXICO WILL BE ON THE DRY AND WINDY SIDE OF THE LOW AS IT EJECTS INTO THE CENTRAL ROCKIES OVER THE UPCOMING WEEKEND. A FEW STORMS COULD IGNITE ALONG THE FAR EASTERN PLAINS LATE IN THE WEEK AS LOW LEVEL MOISTURE SLOSHES BACK AND FORTH. && .FIRE WEATHER... STILL LOOKING FOR ANOTHER ROUND OF SHOWERS AND A MIX OF WET AND DRY THUNDERSTORMS THIS AFTERNOON. CONVECTIVE COVERAGE SHOULD BE SIMILAR TO YESTERDAY...WITH PERHAPS SLIGHTLY MORE ACTIVITY ACROSS THE CENTRAL HIGHLANDS AND EAST CENTRAL PLAINS. OTHERWISE...TEMPS ARE EXPECTED TO BE WITHIN 5 DEGREES OF YESTERDAYS READINGS WITH MINIMUM HUMIDITIES GENERALLY ABOVE 15 PERCENT. HUMIDITY RECOVERIES TONIGHT WILL IMPROVE AGAIN OVER THIS MORNINGS READINGS...MAINLY ACROSS THE EAST...AS GULF MOISTURE ADVECTS INTO THE PLAINS. RECOVERIES WILL BE GOOD TO EXCELLENT MOST AREAS. A PACIFIC LOW WILL APPROACH NM ON MONDAY AND CROSS THE STATE ON TUESDAY. THE AFOREMENTIONED GULF MOISTURE PLUS LIFT AND INSTABILITY AHEAD AND BELOW THE UPPER LOW WILL RESULT IN WIDESPREAD SHOWERS AND THUNDERSTORMS. AREAS ACROSS THE EASTERN PLAINS MAY RECEIVE BETWEEN ONE AND THREE INCHES OF RAINFALL. FLOODING IS POSSIBLE...AS WELL AS SOME SEVERE STORMS IN THE AFTERNOON BOTH MONDAY AND TUESDAY. ELSEWHERE...EXPECT STORMS...THOUGH RAINFALL AMOUNTS WILL NOT BE QUITE AS SIGNIFICANT. TEMPERATURES WILL COOL THROUGH THIS PERIOD...WITH ALL AREAS BETWEEN 5 AND 10 DEGREES BELOW NORMAL TUESDAY AFTERNOON. A WARMING AND DRYING TREND WILL FOLLOW ON WEDNESDAY AND THURSDAY AS A DRY SLOT PUNCHES THROUGH THE STATE. HOWEVER...TEMPS WILL BE NEAR TO JUST BELOW NORMAL. STILL LOOKING FOR A FEW SHOWERS ACROSS THE NORTHWEST ON WEDNESDAY...BUT MOST AREAS SHOULD BE DRY ON THURSDAY...THOUGH SOME DRYLINE ACTIVITY IS NOT OUT OF THE QUESTION. A STRONG LEE SIDE TROUGH WILL DEVELOP ON WEDNESDAY...ALLOWING WEST-SOUTHWESTERLY WINDS TO INCREASE ACROSS THE PLAINS. HUMIDITIES WILL STAY ABOVE 15 PERCENT...PLUS THIS AREA IS EXPECTED TO RECEIVE ABUNDANT RAIN ON MON/TUE...SO NO CRITICAL CONDITIONS ARE EXPECTED. WIND SPEEDS WILL TREND UP ON THURSDAY AND FRIDAY...AS THE NEXT STORM SYSTEM DIVES TOWARD THE GREAT BASIN AND LEE SIDE TROUGHING PERSISTS. A STRONGER DRY SLOT WILL ALSO PUNCH IN OVER NM ON FRIDAY. THE STRONGEST WINDS OF THE WEEK MAY ARRIVE NEXT SATURDAY AS THE SYSTEM LIFTS AND SHIFTS EASTWARD ACROSS UTAH AND COLORADO. TEMPS LOOK TO REMAIN NEAR TO BELOW NORMAL THRU THIS PERIOD. VENTILATION VALUES SHOULD BE GOOD OR BETTER THROUGH THE NEXT 7 DAYS. 34 && .ABQ WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
957 AM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 953 AM CDT SUN MAY 3 2015 BASED ON CURRENT RADAR TRENDS AND HIGH RESOLUTION MODEL SOLUTIONS MAINTAINED ISOLD T THROUGH THE REMAINDER OF THE MORNING ACROSS THE FAR SE CORNER OF THE FA. ALSO MENTIONED SOME SPRINKLES VCNTY VALLEY CITY IN ZONE OF WEAKENING FRONTOGENETIC FORCING. ALSO INCREASED CLOUD COVER THIS MORNING ACROSS ALL BUT THE FAR NORTH AND SOUTH. UPDATE ISSUED AT 648 AM CDT SUN MAY 3 2015 SOME DECENT RADAR RETURNS HAVE DEVELOPED OVER CENTRAL ND ALONG THE 700MB FRONTOGENESIS BAND...WITH A LITTLE BIT OF LIGHT RAIN REACHING THE GROUND AT BIS. THE FRONTOGENESIS WILL BEGIN TO MOVE INTO OUR SOUTHERN COUNTIES BY 15Z...BUT THE RAP AND HRRR HAVE LITTLE TO NO QPF. WILL CONTINUE TO KEEP SOME MINIMAL POPS IN THE SOUTH AND EAST THIS MORNING BUT THINK THAT IT SHOULD BE FAIRLY QUIET. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 346 AM CDT SUN MAY 3 2015 WINDS TODAY AND TEMPERATURES THROUGHOUT THE PERIOD WILL BE THE MAIN FORECAST ISSUES FOR THE SHORT TERM. A SHORTWAVE TROUGH MOVING ACROSS SOUTHERN MANITOBA TODAY AND INTO ONTARIO WILL HELP PUSH A WEAK COLD FRONT THROUGH THE CWA. WINDS HAVE ALREADY SHIFTED TO THE NORTH ACROSS THE DEVILS LAKE BASIN AND NORTHERN RED RIVER VALLEY. THINK THAT THE BOUNDARY WILL BE THROUGH THE SOUTHERN AND EASTERN CWA BY THE 15 TO 18Z TIME FRAME. A FEW LINGERING SHOWERS MAINLY OVER THE SOUTHEASTERN COUNTIES WILL BE POSSIBLE...BUT ANY AMOUNTS WILL BE EVEN LIGHTER THAN YESTERDAY. WINDS WILL BE THE MAIN CONCERN THIS AFTERNOON. THERE WILL BE A FAIRLY DECENT PRESSURE GRADIENT WHICH SHOULD MAKE IT SOMEWHAT BREEZY. MIXING UP TO AROUND 800MB OR SO IS LIKELY...BUT WINDS AT THE TOP OF THE MIXED LAYER ARE ONLY AROUND 20 KTS. THINK THAT SOME SUSTAINED WINDS IN THE TEENS WITH GUSTS ABOVE 20 MPH WILL BE POSSIBLE...ENOUGH TO CAUSE SOME FIRE WEATHER HEADACHES. TEMPS SHOULD BE COOLER THAN YESTERDAY BUT STILL PRETTY MILD...RISING INTO THE 60S TO LOW 70S. TONIGHT...SFC HIGH PRESSURE WILL BUILD INTO THE REGION...BRINGING MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS SHOULD ALLOW TEMPS TO FALL INTO THE UPPER 30S TO LOW 40S. MONDAY WILL ALSO BE VERY QUIET UNDER NEAR ZONAL FLOW AS THE SFC HIGH BEGINS TO MOVE EAST. WINDS SHOULD BE SHIFTING TO THE SOUTH BUT WILL REMAIN FAIRLY LIGHT AND THINK THAT HIGHS AGAIN WILL BE IN THE 60S TO LOW 70S. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 346 AM CDT SUN MAY 3 2015 MONDAY NIGHT THROUGH TUESDAY NIGHT...THE MAIN EVENT WILL BE AN UPPER TROUGH MOVING FROM THE DESERT SOUTHWEST THROUGH COLORADO AND OUT INTO THE CENTRAL PLAINS. SFC LOW PRESSURE WILL BEGIN TO DEVELOP TO OUR WEST AND BRING SOME HIGHER MOISTURE LEVELS AS SOUTHERLY WINDS KICK IN. TEMPS SHOULD BE RISING AGAIN WITH MORE HIGHS IN THE 70S FOR TUESDAY. SFC LOW PRESSURE WILL BE MOVING UP INTO WESTERN SD TUESDAY NIGHT...WITH A WARM FRONT PUSHING INTO ND MAINLY AFTER MIDNIGHT. CONTINUED WITH HIGH POPS FOR TUESDAY NIGHT...AND WITH SHOWALTERS NEAR ZERO KEPT MAINLY SHOWERS WITH ISOLATED THUNDER FOR NOW. WEDNESDAY THROUGH SATURDAY...THE LONG TERM MODELS CONTINUE TO LOOK WET FOR THE MIDDLE PART OF THE WORK WEEK...WITH THE GULF OPENING UP ON TUESDAY FOR DECENT MOISTURE FLUX INTO THE CENTRAL AND NORTHERN PLAINS. A SW UPPER FLOW PATTERN SETS UP ON TUESDAY AND PRECIPITATION BEGINS TO LIFT OUT OF THE CENTRAL PLAINS TUE NIGHT INTO WEDNESDAY. A SFC LOW THEN MOVES INTO NE/SD WED INTO THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS CONTINUE TO HAVE SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY DRY SLOT WHICH MAY OCCUR AS THE LOW LIFTS INTO NW MN AND ONTARIO...HOWEVER THERE IS A STRONG SIGNAL FOR PRECIPITATION ACROSS THE CWA IN THE WED/THU TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO THE DRY FIRE WX CONDS WE HAVE HAD OVER THE LAST SEVERAL WEEKS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 648 AM CDT SUN MAY 3 2015 VFR CONDITIONS CONTINUE WITH ONLY SOME MID AND HIGH CLOUDS THROUGHOUT THE PERIOD. NORTHWEST WINDS WILL PICK UP TO AROUND 15 KTS SUSTAINED WITH GUSTS ABOVE 20 KTS. WINDS WILL DIMINISH BY THIS EVENING AND STAY UNDER 10 KTS THROUGH SUNDAY NIGHT. && .FIRE WEATHER... ISSUED AT 337 AM PM CDT SAT MAY 2 2015 THE LONG TERM MODELS CONTINUE TO LOOK WET FOR THE MIDDLE PART OF THE WORK WEEK...WITH THE GULF OPENING UP ON TUESDAY FOR DECENT MOISTURE FLUX INTO THE CENTRAL AND NORTHERN PLAINS. A SW UPPER FLOW PATTERN SETS UP ON TUESDAY AND PRECIPITATION BEGINS TO LIFT OUT OF THE CENTRAL PLAINS TUE NIGHT INTO WEDNESDAY. A SFC LOW THEN MOVES INTO NE/SD WED INTO THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS CONTINUE TO HAVE SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY DRY SLOT WHICH MAY OCCUR AS THE LOW LIFTS INTO NW MN AND ONTARIO...HOWEVER THERE IS A STRONG SIGNAL FOR PRECIPITATION ACROSS THE CWA IN THE WED/THU TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO THE DRY FIRE WX CONDS WE HAVE HAD OVER THE LAST SEVERAL WEEKS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...VOELKER SHORT TERM...JR LONG TERM...JR/SPEICHER AVIATION...JR FIRE WEATHER...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
648 AM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 648 AM CDT SUN MAY 3 2015 SOME DECENT RADAR RETURNS HAVE DEVELOPED OVER CENTRAL ND ALONG THE 700MB FRONTOGENESIS BAND...WITH A LITTLE BIT OF LIGHT RAIN REACHING THE GROUND AT BIS. THE FRONTOGENESIS WILL BEGIN TO MOVE INTO OUR SOUTHERN COUNTIES BY 15Z...BUT THE RAP AND HRRR HAVE LITTLE TO NO QPF. WILL CONTINUE TO KEEP SOME MINIMAL POPS IN THE SOUTH AND EAST THIS MORNING BUT THINK THAT IT SHOULD BE FAIRLY QUIET. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 346 AM CDT SUN MAY 3 2015 WINDS TODAY AND TEMPERATURES THROUGHOUT THE PERIOD WILL BE THE MAIN FORECAST ISSUES FOR THE SHORT TERM. A SHORTWAVE TROUGH MOVING ACROSS SOUTHERN MANITOBA TODAY AND INTO ONTARIO WILL HELP PUSH A WEAK COLD FRONT THROUGH THE CWA. WINDS HAVE ALREADY SHIFTED TO THE NORTH ACROSS THE DEVILS LAKE BASIN AND NORTHERN RED RIVER VALLEY. THINK THAT THE BOUNDARY WILL BE THROUGH THE SOUTHERN AND EASTERN CWA BY THE 15 TO 18Z TIME FRAME. A FEW LINGERING SHOWERS MAINLY OVER THE SOUTHEASTERN COUNTIES WILL BE POSSIBLE...BUT ANY AMOUNTS WILL BE EVEN LIGHTER THAN YESTERDAY. WINDS WILL BE THE MAIN CONCERN THIS AFTERNOON. THERE WILL BE A FAIRLY DECENT PRESSURE GRADIENT WHICH SHOULD MAKE IT SOMEWHAT BREEZY. MIXING UP TO AROUND 800MB OR SO IS LIKELY...BUT WINDS AT THE TOP OF THE MIXED LAYER ARE ONLY AROUND 20 KTS. THINK THAT SOME SUSTAINED WINDS IN THE TEENS WITH GUSTS ABOVE 20 MPH WILL BE POSSIBLE...ENOUGH TO CAUSE SOME FIRE WEATHER HEADACHES. TEMPS SHOULD BE COOLER THAN YESTERDAY BUT STILL PRETTY MILD...RISING INTO THE 60S TO LOW 70S. TONIGHT...SFC HIGH PRESSURE WILL BUILD INTO THE REGION...BRINGING MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS SHOULD ALLOW TEMPS TO FALL INTO THE UPPER 30S TO LOW 40S. MONDAY WILL ALSO BE VERY QUIET UNDER NEAR ZONAL FLOW AS THE SFC HIGH BEGINS TO MOVE EAST. WINDS SHOULD BE SHIFTING TO THE SOUTH BUT WILL REMAIN FAIRLY LIGHT AND THINK THAT HIGHS AGAIN WILL BE IN THE 60S TO LOW 70S. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 346 AM CDT SUN MAY 3 2015 MONDAY NIGHT THROUGH TUESDAY NIGHT...THE MAIN EVENT WILL BE AN UPPER TROUGH MOVING FROM THE DESERT SOUTHWEST THROUGH COLORADO AND OUT INTO THE CENTRAL PLAINS. SFC LOW PRESSURE WILL BEGIN TO DEVELOP TO OUR WEST AND BRING SOME HIGHER MOISTURE LEVELS AS SOUTHERLY WINDS KICK IN. TEMPS SHOULD BE RISING AGAIN WITH MORE HIGHS IN THE 70S FOR TUESDAY. SFC LOW PRESSURE WILL BE MOVING UP INTO WESTERN SD TUESDAY NIGHT...WITH A WARM FRONT PUSHING INTO ND MAINLY AFTER MIDNIGHT. CONTINUED WITH HIGH POPS FOR TUESDAY NIGHT...AND WITH SHOWALTERS NEAR ZERO KEPT MAINLY SHOWERS WITH ISOLATED THUNDER FOR NOW. WEDNESDAY THROUGH SATURDAY...THE LONG TERM MODELS CONTINUE TO LOOK WET FOR THE MIDDLE PART OF THE WORK WEEK...WITH THE GULF OPENING UP ON TUESDAY FOR DECENT MOISTURE FLUX INTO THE CENTRAL AND NORTHERN PLAINS. A SW UPPER FLOW PATTERN SETS UP ON TUESDAY AND PRECIPITATION BEGINS TO LIFT OUT OF THE CENTRAL PLAINS TUE NIGHT INTO WEDNESDAY. A SFC LOW THEN MOVES INTO NE/SD WED INTO THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS CONTINUE TO HAVE SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY DRY SLOT WHICH MAY OCCUR AS THE LOW LIFTS INTO NW MN AND ONTARIO...HOWEVER THERE IS A STRONG SIGNAL FOR PRECIPITATION ACROSS THE CWA IN THE WED/THU TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO THE DRY FIRE WX CONDS WE HAVE HAD OVER THE LAST SEVERAL WEEKS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 648 AM CDT SUN MAY 3 2015 VFR CONDITIONS CONTINUE WITH ONLY SOME MID AND HIGH CLOUDS THROUGHOUT THE PERIOD. NORTHWEST WINDS WILL PICK UP TO AROUND 15 KTS SUSTAINED WITH GUSTS ABOVE 20 KTS. WINDS WILL DIMINISH BY THIS EVENING AND STAY UNDER 10 KTS THROUGH SUNDAY NIGHT. && .FIRE WEATHER... ISSUED AT 337 AM PM CDT SAT MAY 2 2015 THE LONG TERM MODELS CONTINUE TO LOOK WET FOR THE MIDDLE PART OF THE WORK WEEK...WITH THE GULF OPENING UP ON TUESDAY FOR DECENT MOISTURE FLUX INTO THE CENTRAL AND NORTHERN PLAINS. A SW UPPER FLOW PATTERN SETS UP ON TUESDAY AND PRECIPITATION BEGINS TO LIFT OUT OF THE CENTRAL PLAINS TUE NIGHT INTO WEDNESDAY. A SFC LOW THEN MOVES INTO NE/SD WED INTO THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS CONTINUE TO HAVE SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY DRY SLOT WHICH MAY OCCUR AS THE LOW LIFTS INTO NW MN AND ONTARIO...HOWEVER THERE IS A STRONG SIGNAL FOR PRECIPITATION ACROSS THE CWA IN THE WED/THU TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO THE DRY FIRE WX CONDS WE HAVE HAD OVER THE LAST SEVERAL WEEKS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...JR SHORT TERM...JR LONG TERM...JR/SPEICHER AVIATION...JR FIRE WEATHER...SPEICHER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1048 AM EDT SUN MAY 3 2015 .SYNOPSIS... HIGH PRESSURE WILL GENERALLY DOMINATE THE REGION THROUGH MUCH OF NEXT WEEK. ISOLATED SHOWERS AND OR THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON DURING PEAK HEATING OVER THE MOUNTAINS...WITH CHANCES IMPROVING SLIGHT OUT OVER THE PIEDMONT BY THURSDAY AS A WEAK FRONT SLIDES INTO THE REGION. TEMPERATURES WILL RISE TO ABOVE NORMAL LEVELS...WITH HIGHS TOPPING OUT IN THE LOWER TO MID 80S THE LATTER HALF OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1045 AM EDT...TEMPERATURES ARE OFF TO A WARM START IN MOST PLACES AS THE EXPECTED HIGH LEVEL STRATOCUMULUS FIELD HAS NOT FILLED IN APPRECIABLY YET. STILL ANTICIPATE SOME INCREASING CLOUD COVER BELOW A MID LEVEL CAP...BUT WARM MORNING THICKNESSES WILL REQUIRE A ONE DEGREE BOOST IN TEMPS IN MOST PLACES. THE LATEST HRRR RUNS CONTINUE TO FEATURE LITTLE MORE THAN ISOLD AIRMASS TYPE SHOWERS...BUT WITH A GENERAL FOCUS ALONG THE ERN SIDE OF THE MTNS IN DEVELOPING LIGHT UPSLOPE. VERY LITTLE CHANGE TO THE POP FORECAST IS EXPECTED...WITH A RELATIVE FORCING MAXIMUM TOWARD 21Z WITH THE PASSING OF AN UPPER SHORTWAVE TO THE N. ANY AFTN/EARLY EVENING SHOWER ACTIVITY WILL WANE QUICKLY WITH SUNSET TONIGHT. ANOTHER ROUND OF HIGH STRATOCUMULUS/LOW ALTOCU TRAPPED UNDER THE INVERSION WILL KEEP SOME MEASURE OF CLOUDS GOING ALL NIGHT. IN ADDITION...THE AIRMASS WILL CONTINUE TO MODIFY WITH RISING MIN TEMPS. && .SHORT TERM /MONDAY THROUGH TUESDAY/... AS OF 230 AM EDT SUNDAY...THE SHORT TERM FCST PERIOD INITIALIZES MONDAY MORNING AMIDST BROAD FLAT H5 SUBTROPICAL RIDGE...WITH A WEAK DISTURBANCE SLIDING THROUGH THE MEAN FLOW ATOP THE SOUTHERN APPS. AT THE SURFACE...HIGH PRESSURE OFF THE CAROLINA COAST WILL CONTINUE TO ALLOW FOR SOUTHERLY WAA ACROSS NORTHEAST GA AND THE WESTERN CAROLINAS. STEEPENING LOW LEVEL LAPSE RATES DUE TO DIURNAL HEATING ALONG WITH ABOVE MENTIONED UPPER IMPULSE WARRANT CHANCE LEVELS POPS ACROSS THE HIGH TERRAIN ON MONDAY WHERE REGION OF BEST INSTABILITY AND LEAST CIN WILL RESIDE. POPS TAPER SHARPLY TO NON MENTIONABLE LEVEL THROUGH THE FOOTHILLS...LEADING TO A DRY FCST FOR THE PIEDMONT AREAS DUE TO PROXIMITY OF THE PARENT SURFACE HIGH. THE PRIMARY UPPER RIDGE AXIS WILL SHIFT OVERHEAD ON TUESDAY WHICH IS EXPECTED TO LIMIT CONVECTION SOMEWHAT...ESPECIALLY OUTSIDE OF THE MTNS. INSTABILITY WILL BE MAXIMIZED OVER THE HIGH TERRAIN...WHICH COMBINED WITH WEAKER LOW LEVEL CIN DUE TO RETREATING PARENT SURFACE HIGH...CONTINUE TO WARRANT CHANCE POPS. AS STATED ABOVE...EXPECTING ANY CAPPING TO HOLD OUTSIDE OF THE HIGH TERRAIN THUS THE FCST REMAINS DRY FOR TUESDAY ACROSS THESE ZONES. ANY HEAVIER SHOWERS/THUNDERSTORMS THAT DO DEVELOP COULD PRODUCE LOCALLY HEAVY RAINFALL AMOUNTS AS STORM MOTIONS WILL LIKELY BE LESS THAN 5-8KTS...ESPECIALLY ON TUESDAY WHEN MID LEVEL FLOW WEAKENS. OTHERWISE...PARTLY CLOUDY SKIES WILL PREVAIL AMIDST LIGHT SOUTHERLY FLOW. TEMPERATURES THROUGH THE PERIOD WILL EXCEED NORMAL LEVELS WITH HIGHS TOPPING OUT IN THE LOWER 80S ON TUESDAY. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 245 AM EDT SUNDAY...THE MEDIUM RANGE FCST PERIOD INITIALIZES WEDNESDAY MORNING WITH LITTLE TO NO CHANGES MADE TO THE PREVIOUS FCST. HIGHLIGHTS OF THE PERIOD CONTINUE TO BE PREVAILING SUBTROPICAL H5 RIDGE OVER EAST/CENTRAL CONUS WHILE SURFACE HIGH PRESSURE REMAINS CENTERED OVER NEW ENGLAND. FURTHER SOUTH OVER THE NORTHERN CARRIBEAN...A MIDLEVEL DISTURBANCE AND ASSOCIATED HYBRID LOW WILL HAVE FORMED AND MIGRATED NORTHWARD OF THE EAST COAST OF FLORIDA. CLOSER TO HOME...BROAD MID/UPPER LEVEL SUBSIDENCE PATTERN IS EXPECTED TO PREVAIL INITIALLY LEADING TO A CAPPED ENVIRONMENT WITH LITTLE IN THE WAY OF TRIGGERING AVAILABLE FOR CONVECTION ACROSS THE PIEDMONT REGIONS. HOWEVER...OVER THE MOUNTAINS MODELS FAVOR INCREASING INSTABILITY WITH ESE UPSLOPING FLOW PRESENT TO AID CAP EROSION ON WEDNESDAY. THUS...SLIGHT/CHANCE LEVEL POPS ARE FEATURED. ON THURSDAY POPS WILL EXPAND FURTHER INTO THE NC/SC PIEDMONT AND NORTHEAST GA AS THE ABOVE MENTIONED HYBRID LOW...AND ITS LOCATION AT THE TIME BECOMES VITAL TO THE FCST. MODEL DISCONTINUITY AS TO ITS LOCATION WOULD PROVIDE VASTLY DIFFERENT OUTCOMES AS IT PERTAINS TO SENSIBLE WX FOR THE REMAINDER OF THE PERIOD. THE GFS HAS THE LOW SETUP APPROX 2-3 HUNDRED MILES OFF THE SC COAST THURSDAY AFTERNOON...WHILE THE ECMWF IS ABOUT THE SAME DISTANCE FURTHER OUT TO SEA. THE GFS SOLUTION WOULD RESULT IN FLOW ON THE WESTERN FLANK OF THE WAVE YIELDING A NORTHERLY COMPONENT OF MOTION...WHICH WOULD AID INTRUSION OF A WEAK BACK DOOR FRONT INTO THE REGION. THE ECMWF ON THE OTHER HAND INDICATES THE SAME BACK DOOR FRONT...ALBEIT WEAKER. IF THE GFS VERIFIED THE FROPA COULD PROVIDE ENOUGH OF A FOCUS FOR CONVECTION TO OCCUR OUTSIDE OF THE MTNS...THEREFORE FOR THE FCST SLIGHT CHANCE POPS ARE MENTIONED. BOTH THE GFS/ECMWF ILLUSTRATE A WESTWARD JAUNT OF THE LOW ON FRIDAY/SATURDAY EFFECTIVELY KEEPING IT JUST OFF THE GA/SC COAST PER THE GFS...AND THE SC/NC COAST PER THE ECMWF. MOISTURE WRAPPING AROUND THE LOW SHOULD STAY JUST TO THE EAST...THEREFORE THE FCST IS DRY FOR PIEDMONT REGIONS ALL THE WHILE FEATURING SLIGHT/CHANCE LEVEL POPS OVER MTNS WHERE DIURNAL CONVECTION IS FAVORED. TEMPERATURES THROUGH THE PERIOD WILL CONTINUE TO MODERATE TO 5-8 DEGREES ABOVE CLIMO. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... AT KCLT AND ELSEWHERE...VFR IS EXPECTED THROUGH THE PERIOD COURTESY OF DRY HIGH PRESSURE. WILL CONTINUE TO SEE SOME HIGH BASED STRATOCU TRAPPED UNDER THE SUBSIDENCE INVERSION...BUT THIS SHOULD NOT BE OPERATIONALLY SIGNIFICANT. EXPECT WINDS TO COME UP FROM THE SSE TO SSW THROUGH EARLY AFTN AS HIGH PRESSURE MOVES OFF THE COAST. WITH HIGH PRESSURE TO THE EAST...SOME MOISTURE RETURN WILL TAKE PLACE FROM THE S. A CU FIELD IS EXPECTED TO DEVELOP FROM MIDDAY ONWARD...THAT WILL PROBABLY RESULT IN A CEILING IN MOST PLACES IN THE AFTERNOON...BUT WITH A CLOUD BASE AT 060 OR HIGHER. THE MODELS ARE MORE SUPPORTIVE/REACTIVE WITH PRECIP OVER THE HIGHER TERRAIN THIS AFTERNOON...SO A VICINITY SHOWER WAS INCLUDED AT KAVL. OUTLOOK...RETURN FLOW MOISTURE WILL SLOWLY REDEVELOP THROUGH MID WEEK...PRODUCING ISOLD TO SCATTERED DIURNAL CONVECTION EACH DAY... MAINLY OVER THE HIGH TERRAIN. CONFIDENCE TABLE... 14-20Z 20-02Z 02-08Z 08-12Z KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100% KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100% KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100% KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE) WWW.WEATHER.GOV/GSP/AVIATION_TABLES && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...CDG/HG NEAR TERM...HG SHORT TERM...CDG LONG TERM...CDG AVIATION...HG/PM
AREA FORECAST DISCUSSION
NWS AMARILLO TX
520 AM CDT SUN MAY 3 2015 .DISCUSSION... NO SIGNIFICANT CHANGES WERE NEEDED TO THE PREVIOUS FORECAST. CURRENT WATER VAPOR AND RAP ANALYSIS SHOW AN UPPER LOW CURRENTLY OFF THE CALIFORNIA COAST MOVING EASTWARD. THIS WILL BE THE IMPETUS FOR WIDESPREAD POTENTIALLY HEAVY RAINFALL EARLY NEXT WEEK ACROSS THE ENTIRE FORECAST AREA. BROAD BUT WEAK UPPER LEVEL RIDGING IS PRESENT OVER THE SOUTH-CENTRAL UNITED STATES AND WILL HAVE LESS INFLUENCE ON OUR WEATHER AS IT CONTINUES TO WEAKEN AND SHIFT EASTWARD. INITIAL PRECIPITATION CHANCES WILL BE TIED TO DIURNAL CYCLE AND OROGRAPHIC EFFECTS OF THE HIGH TERRAIN IN NEW MEXICO WITH CONVECTION BECOMING FAIRLY NUMEROUS THERE BY EARLY/MID AFTERNOON. MEAN WESTERLY FLOW WILL REMAIN RATHER WEAK RESULTING IN SLOW EASTWARD PROGRESSION OF THIS CONVECTION. FURTHER EAST ONTO THE NEW MEXICO PLAINS AND ACROSS AT LEAST THE WESTERN PORTION OF THE PANHANDLES...DEEP MIXING DURING THE AFTERNOON SHOULD BE SUFFICIENT FOR SCATTERED HIGH BASED CONVECTION TO DEVELOP. DEEP DRY SUB-CLOUD LAYER WILL LIMIT PRECIPITATION AMOUNTS BUT COULD RESULT IN STRONG WIND GUSTS WITH THE MOST ROBUST CONVECTION. CONVECTION SHOULD SLOWLY WEAKEN DURING THE EVENING AND EARLY SUNDAY NIGHT. UPPER FLOW BECOMES INCREASINGLY DIFLUENT ON MONDAY AS THE UPPER LOW APPROACHES. EVEN EARLY IN THE DAY SUFFICIENT LARGE SCALE FORCING AND MOISTURE ADVECTION IS PRESENT TO JUSTIFY AT LEAST LOW PRECIPITATION PROBABILITIES PRIMARILY ACROSS THE WESTERN HALF OF THE AREA. 00Z RAOB FROM COASTAL TEXAS OFFICES STILL LACK DEEP MOISTURE BUT LATEST SATELLITE DERIVED TPW SHOWS INCREASING MOISTURE ACROSS THE WESTERN GULF. MODEL GUIDANCE IS INSISTENT ON A SURGE OF LOW LEVEL MOISTURE AND ABOVE CLIMO PWAT VALUES INTO THE AREA BY LATE MONDAY WITH STRENGTHENING LEE TROUGH AND SOUTHERLY WINDS. THIS INCREASE IN MOISTURE COMBINED WITH THE ABOVE MENTIONED LARGE SCALE FORCING SHOULD RESULT IN WIDESPREAD RAIN. SPATIAL AND TEMPORAL DETAILS OF HEAVY RAIN AND POTENTIAL FLOODING ARE STILL A BIT UNCLEAR BUT THE PATTERN FITS THESE THREATS. ONE TO THREE INCHES SEEMS LIKELY. THE MAJORITY OF THE RAINFALL WILL OCCUR MONDAY NIGHT THROUGH THE FIRST HALF OF TUESDAY. SEVERE THUNDERSTORM POTENTIAL SHOULD BE MOST LIKELY...ALBEIT STILL RELATIVELY LOW AND MARGINAL...MONDAY AFTERNOON AND EVENING COINCIDENT WITH LOW LEVEL MOISTURE SURGE BENEATH STEEPENING MID LEVEL LAPSE RATES. THIS SHOULD YIELD AT LEAST MARGINAL INSTABILITY AND DEEPER/STRONGER CONVECTION THAN THE PREVIOUS DAY. EFFECTIVE SHEAR MAY BE MARGINAL FOR STORM ORGANIZATION THOUGH. SIGNIFICANT CONVECTIVE OVERTURNING SHOULD WEAKEN MID LEVEL LAPSE RATES ON TUESDAY PRECLUDING A NOTEWORTHY SEVERE WEATHER THREAT ALTHOUGH IF POCKETS OF INSTABILITY CAN DEVELOP SOME STRONG TO SEVERE THUNDERSTORMS WOULD BE POSSIBLE. ONE OF THE FEW CHANGES THAT WERE MADE TO THE FORECAST WAS TO LOWER HIGH TEMPERATURES ON TUESDAY TO ACCOUNT FOR WIDESPREAD CLOUDS AND PRECIPITATION THAT WILL LIKELY LIMIT THE MAGNITUDE OF DIURNAL HEATING. AS UPPER LOW/OPENING WAVE DEPARTS...WEAK SHORTWAVE RIDGING WILL BRIEFLY INFLUENCE THE AREA RESULTING IN A MOSTLY DRY DAY AND TEMPERATURES RETURNING TO THE UPPER 70S AND LOWER 80S. A DEEP CLOSED LOW WILL EVOLVE ALONG THE WEST COAST BY THURSDAY AND WITH STRENGTHENING MEAN SOUTHWESTERLY FLOW LEE TROUGHING WILL PERSIST/STRENGTHEN. MULTIPLE DAYS OF DRYLINE CONVECTION MAY OCCUR FROM LATE WEEK THROUGH THE WEEKEND WITH HIGHEST PRECIPITATION PROBABILITIES ACROSS THE EASTERN HALF OF THE AREA. SPREAD IN THE ENSEMBLE AND UNCERTAINTY WITH TIMING OF SMALL LEAD WAVES AND EASTWARD PROGRESSION OF UPPER LOW MAKES IT DIFFICULT TO DELINEATE WHEN THE HIGHEST PROBABILITY OF PRECIPITATION WILL BE. SUBSEQUENT FORECASTS WILL REFINE THESE DETAILS. BRB && .PRELIMINARY POINT TEMPS/POPS... AMARILLO TX 84 59 75 57 64 / 20 30 50 80 80 BEAVER OK 89 60 82 60 66 / 20 30 40 70 80 BOISE CITY OK 84 56 75 54 65 / 30 30 60 80 70 BORGER TX 87 60 78 59 65 / 20 30 50 80 80 BOYS RANCH TX 87 59 78 58 66 / 30 40 60 80 80 CANYON TX 85 59 75 57 65 / 20 30 60 80 80 CLARENDON TX 84 60 76 59 65 / 10 30 30 70 80 DALHART TX 85 56 76 55 66 / 40 30 60 80 80 GUYMON OK 87 58 79 58 65 / 30 30 60 80 80 HEREFORD TX 85 58 76 57 65 / 30 30 60 80 80 LIPSCOMB TX 85 60 79 60 65 / 20 30 30 70 80 PAMPA TX 83 58 76 57 63 / 20 30 40 80 80 SHAMROCK TX 83 60 77 60 66 / 10 20 30 70 80 WELLINGTON TX 85 61 78 61 68 / 5 20 30 60 80 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 15/17
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
630 AM CDT SUN MAY 3 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 321 AM CDT SUN MAY 3 2015 REGIONAL RADARS THIS MORNING SHOWING SOME CONVECTIVE ACTIVITY OVER CENTRAL AND WESTERN IOWA. THIS IS OCCURRING ON THE NOSE OF THE LOW LEVEL JET AND AHEAD OF A SHORT WAVE TROUGH MOVING ACROSS NORTHERN NEBRASKA. THE 03.03Z RAP INDICATES THIS WAVE WILL CONTINUE TO TRACK EASTWARD ACROSS NORTHERN IOWA THROUGH THE MORNING WITH THE LOW LEVEL JET VEERING TO THE EAST TO REMAIN AHEAD OF THE WAVE. THE RAP...03.04Z HRRR AND THE 03.00Z HI-RES ARW AND NMM ALL SUGGEST THERE IS A CHANCE THAT SOME OF THE ACTIVITY WITH THIS WAVE COULD GET INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN AND HAVE ADDED IN A SMALL CHANCE FOR THIS THROUGH ABOUT THE MIDDLE OF THE MORNING. THE MAIN CONVECTIVE SHOW WILL COME LATE THIS AFTERNOON INTO THE EVENING. THE 03.00Z MODELS HAVE REMAIN FAIRLY CONSISTENT TAKING THE MAIN SHORT WAVE TROUGH...CURRENTLY OVER SASKATCHEWAN...ALMOST DUE EAST WITH A SLIGHT POSITIVE TILT AND THE PV ADVECTION IN THE 500-300 MB LAYER REMAINING NORTH OF THE AREA. AS THIS WAVE MOVES EAST...IT WILL PUSH A COLD FRONT INTO THE AREA LATE THIS AFTERNOON AND THEN ACROSS THE REGION TONIGHT. BUFKIT SOUNDINGS FROM THE 03.00Z NAM INDICATE A PRETTY DEEP MIXED LAYER...UP TO ABOUT 850 MB...AHEAD OF THE FRONT THAT COULD BRING DOWN SOME DRIER AIR AND KEEP THE DEW POINTS CAPPED IN THE MID 50S. WITH 925 MB TEMPERATURES RISING ABOUT 2 TO 3C OVER SATURDAY...EXPECT THE SURFACE TEMPERATURES TO BE WARMER THAN SATURDAY WITH MIDDLE 80S FOR MUCH OF THE AREA. THE COMBINATION OF THESE TEMPS AND DEW POINTS SHOULD YIELD ML CAPES AROUND 1500 J/KG OR SO ALONG AND AHEAD OF THE FRONT. THE FORECAST SOUNDINGS ALSO SHOW A WEAK CAP IN THE WARM SECTOR AHEAD OF THE FRONT AND WITH MINIMAL HEIGHT FALLS...IT WILL TAKE THE THERMODYNAMIC FORCING WITH THE FRONT TO BREAK THE CAP. THE FRONTOGENESIS WITH THE FRONT LOOKS TO BE MODERATE IN STRENGTH IN THE 1000-850 MB AND THEN WEAK FROM 850 MB UP THROUGH 500 MB. THIS SHOULD BE ENOUGH TO BREAK THE WEAK CAP AND ALLOW CONVECTION TO FORM ALONG THE FRONT. THERE IS GOOD CLUSTERING AMONG THE HI-RES MESO MODELS...THE 03.00Z NAM12 AND 03.00Z NESTED NAM THAT THE FRONT SHOULD START TO APPROACH LATE THIS AFTERNOON WITH THE CONVECTION FIRST IMPACTING THE NORTHERN PARTS OF THE AREA IN THE 21Z-24Z WINDOW AND THEN DEVELOPING SOUTHWEST ALONG THE FRONT VERY LATE IN THE AFTERNOON INTO THE EARLY EVENING. THIS ACTIVITY SHOULD REMAIN STRONG INTO THE MIDDLE OF THE EVENING BEFORE THE CAPE QUICKLY DWINDLES WITH JUST GENERAL CONVECTION EXPECTED FOR CENTRAL AND SOUTHWEST WISCONSIN. THE SEVERE THREAT IS STILL PRESENT FROM ABOUT 4 PM THROUGH 10 PM WITH LARGE HAIL LOOKING TO BE THE MAIN THREAT AS GOOD MID LEVEL LAPSE RATES SHOULD AID IN THE HAIL PRODUCTION. NOT EXPECTING THE HAIL TO BE OVERLY LARGE AS A GENERAL LACK OF SHEAR WILL KEEP THE UPDRAFT ROTATION SUBDUED. WHAT SHEAR THERE IS WILL BE IN THE 0-3KM LAYER AND IS EXPECTED TO BE ON THE ORDER OF 25 TO 30 KNOTS...WHICH SHOULD BE ENOUGH TO PRODUCE SOME WIND GUSTS BUT MAY NOT BE ENOUGH TO KEEP THE GUST FRONTS CLOSE TO THE STORMS. THE MODELS NOW SUGGEST THE FRONT MAY NOT PUSH AS FAR SOUTH AS PREVIOUSLY INDICATED BEFORE STALLING OUT MONDAY. THE GENERAL MODEL CONSENSUS NOW SHOWS THE FRONT STALLING OVER SOUTHERN IOWA INSTEAD OF NORTHERN MISSOURI. THIS CLOSER PROXIMITY TO THE AREA COULD ALLOW SOME OF THE SHOWERS AND STORMS EXPECTED TO OCCUR NORTH OF THE FRONT TO CONTINUE OVER NORTHEAST IOWA INTO SOUTHWEST WISCONSIN MONDAY AFTERNOON AND EVENING. THE UPPER LEVEL PATTERN WILL START TO SHIFT TO MORE OF A SOUTHWEST FLOW AND BEGIN TO PUSH THE FRONT BACK TO THE NORTH LATE MONDAY NIGHT RESULTING IN A NORTHWARD EXPANSION OF THE RAIN CHANCES OVER ALL OF SOUTHEAST MINNESOTA AND MUCH OF WESTERN AND CENTRAL WISCONSIN. MOST OF THE AREA WILL THEN HAVE A CHANCE FOR RAIN TUESDAY AS THE FRONT MOVES BACK INTO THE AREA AND COULD POSSIBLY BE ACCOMPANIED BY A SHORT WAVE TROUGH ALOFT IN THE SOUTHWEST FLOW. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 321 AM CDT SUN MAY 3 2015 THE SOUTHWEST FLOW ALOFT LOOKS TO CONTINUE THROUGH THE PERIOD AS THE MAIN RIDGE REMAINS OVER THE EASTERN CONUS AND A LARGE UPPER LEVEL LOW SINKS SLOWLY SOUTH OVER THE WESTERN CONUS. WITH THIS FLOW PATTERN...SEVERAL PIECES OF ENERGY ARE EXPECTED TO COME OUT AND ACROSS THE UPPER MIDWEST. IT LOOKS AS IF IT WILL TAKE UNTIL SOMETIME WEDNESDAY OR WEDNESDAY NIGHT FOR THE RETREATING FRONT TO GET NORTH OF THE AREA. ONCE THIS HAPPENS...A COLD FRONT AND SURFACE LOW PRESSURE WILL START TO APPROACH FROM THE WEST WITH WHAT SHOULD BE A STRONGER SHORT WAVE TROUGH ALOFT. THIS FRONT WILL THEN MOVE ACROSS THE AREA IN THE END OF THE WORK WEEK WITH IT POSSIBLY BECOME STALLED OUT JUST TO THE SOUTH OF THE AREA INTO THE START OF THE WEEKEND. WITH THIS MESSY PATTERN...WILL CARRY RAIN CHANCES EACH DAY...ALTHOUGH WOULD NOT BE SURPRISED TO SEE A DRY PERIOD OR TWO...ESPECIALLY ONCE THE RETURNING FRONT GETS PAST THE AREA. HOWEVER...CONFIDENCE ON THIS IS TOO LOW TO WORK INTO THE FORECAST AT THIS TIME. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 630 AM CDT SUN MAY 3 2015 MAIN AVIATION CONCERNS ARE THUNDERSTORMS AT BOTH RST/LSE TAF SITES LATE THIS AFTERNOON INTO THIS EVENING. LATEST 11Z SURFACE ANALYSIS SHOWS COLD FRONT EXTENDING FROM SOUTHERN ONTARIO INTO SOUTHERN SOUTH DAKOTA. COLD FRONT IS EXPECTED TO PUSH EAST INTO WESTERN WISCONSIN AND SOUTHEAST MINNESOTA LATE THIS AFTERNOON AND EVENING. DUE TO DAYTIME HEATING OUT AHEAD OF THE COLD FRONT...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND BEHIND THE FRONT AFTER 21Z TODAY. THE LATEST MODEL TRENDS HAVE SLOWED THE PROGRESSION OF THE FRONT/DEVELOPMENT OF CONVECTION AND HAVE DELAYED THE ONSET OF CONVECTION AT THE RST/LSE TAF SITES BEGINNING AROUND 00Z AT RST AND 01Z LSE. COLD FRONT...AND ASSOCIATED CONVECTION...WILL MOVE SOUTH OF THE TAF SITES BY 04-06Z MONDAY. FEW OF THE THUNDERSTORMS MAY BECOME SEVERE...HOWEVER CONFIDENCE IN THE EXACT PLACEMENT/LOCATION OF ANY SEVERE THUNDERSTORMS IS LOW. WIND GUST OF UP TO 60 MPH AND LARGE HAIL ARE POSSIBLE WITH THE THUNDERSTORMS FROM 21Z TODAY TO 04Z MONDAY. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS PUEBLO CO
236 PM MDT SUN MAY 3 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 234 PM MDT SUN MAY 3 2015 SHOWERS AND STORMS THAT HAVE DEVELOPED THIS AFTERNOON HAVE GENERALLY BE FAIRLY SLOW MOVING AND SHORT LIVED. ISOLATED TO SCATTERED SHOWERS AND TSTMS OVR THE AREA WL CONTINUE INTO THE EVENING HOURS...AND DECREASING TOWARD MIDNIGHT. A COLD FRONT WL MOVE SOUTH INTO THE SOUTHEAST PLAINS THIS EVENING...WITH THE NAM SHOWING IT REACHING THE SRN CO BORDER EARLY MON MORNING. BEHIND THE FRONT...SFC DEW POINTS INCREASE INTO THE 40S...AND LOW STRATUS IS FORECAST TO DEVELOP OVR NORTHERN EL PASO COUNTY BY MIDNIGHT AND THEN SPREADING SOUTHWARD OVERNIGHT. THE HRRR...NSSL WRF AND NAM CONTINUE TO SHOW PCPN BEHIND THE FRONT OVR EL PASO AND TELLER COUNTIES DURING THE LATE NIGHT HOURS...WITH MUCH OF THE REST OF THE FORECAST AREA BEING DRY. THE HRRR SPREADS PCPN SOUTHWARD INTO PUEBLO AND FREMONT COUNTIES AS WELL. ON MONDAY AN UPR LOW BECOME CENTERED OVR THE CA AND AZ BORDER WITH SOUTHERLY FLOW ALOFT OVR THE FORECAST AREA AHEAD OF THIS SYSTEM...DRAWING MSTR NORTHWARD. WITH MOIST LOW TO MID LEVEL SOUTHEASTERLY WINDS...KEEPING AFTERNOON SFC DEW POINTS ACRS THE SERN PLAINS IN THE MID40S TO LOWER 50S. MOST OF THE LOW STRATUS IS EXPECTED TO DISSIPATE BEFORE AFTERNOON. THE NAM SHOWS SHOWERS/TSTMS DEVELOPING IN THE MID MORNING HOURS OVR THE MTNS...ESPECIALLY ALONG THE CONTDVD...WHERE A SHORTWAVE TROF IS EXPECTED TO MOVE NORTHWARD THRU THE AREA. PCPN WL INCREASE ACRS THE MTNS BY MIDDAY AND WL SPREAD TO THE ADJACENT LOWER ELEVATIONS...AND THEN THROUGH THE AFTERNOON WL BECOME WIDESPREAD ACRS MOST OF THE FORECAST AREA. THERE WL BE THE POTENTIAL FOR LOCALIZED HEAVY RAIN. ALSO...PORTIONS OF THE SERN PLAINS COULD SEE ONE OR TWO MARGINALLY SEVERE STORMS IN THE AFTERNOON. HIGH TEMPS ON MON WILL BE COOLER THAN TODAY AND SHOULD GENERALLY BE JUST A LITTLE BELOW NORMAL. HIGH TEMPS IN THE SAN LUIS VALLEY SHOULD BE CLOSE TO NORMAL. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 234 PM MDT SUN MAY 3 2015 ...STORMY WEATHER THROUGH TUESDAY... MONDAY NIGHT...WILL SEE SEVERAL ONGOING ROUNDS OF PRECIP AND STORMS OVER THE AREA. THE STRONGEST OF THESE WILL LIKELY BE OVER THE ERN PLAINS...GENERALLY E OF KLHX...AND ANOTHER AREA OVER THE PALMER DVD. GIVEN THE ABUNDANT LLVL MOISTURE AND INCREASED SHEAR DUE TO BACKED LLVL FLOW...CANNOT RULE OUT A STRONG TO SVR STORM OR TWO ESPECIALLY IN THESE FAVORED AREAS. COULD SEE A BRIEF LULL IN THE PRECIP MON EVE BEFORE PRECIP COVERAGE INCREASES LATER MON NIGHT...IN BANDS OF CONVECTION ROTATING UP FROM THE SOUTH. WILL MAINTAIN ISOLD OR SLIGHT CHANCE OF TS OVERNIGHT ALONG WITH MORE WIDESPREAD LIKELY POPS ACROSS THE MTS AND PLAINS. ON TUE...THE UPPER LOW WILL MOVE INTO THE FOUR CORNERS REGION...THEN TRACK TO THE NE DURING THE DAY. TEMPS WILL BE COOLER...IN THE 60S FOR THE PLAINS...DUE TO WIDESPREAD CLOUDS AND PRECIP. IT LOOKS LIKE MUCH OF THE BEST PRECIP COVERAGE WILL BE TUE MORNING...ALTHOUGH EVEN IF THERE ARE ANY BREAKS IN THE SHOWERS AND STORMS...THEY SHOULD PICK UP AGAIN BY TUE AFTERNOON. SNOW LEVELS MON-TUE WILL BE PRETTY HIGH...BUT GIVEN THE AMOUNT OF QPF...COULD SEE SOME LOCAL SIGNIFICANT ACCUMS IN THE MTS OF SIX INCHES OR MORE...ESPECIALLY ABOVE 12000 FEET. SO...RECREATIONISTS SHOULD BE AWARE OF WINTER CONDITIONS FOR THE HIGH PEAKS. GIVEN ALL THE PRECIP...THE BL SHOULD BE PRETTY STABILIZED BY TUE SO SURFACE BASED CONVECTION LOOKS UNLIKELY. BUT...A STRONG STORM OR TWO CANNOT BE RULED OUT OVER THE AREA AS THE UPPER LOW MOVES THROUGH NRN CO. BY WED...SHOULD SEE THINGS WINDING DOWN AS THE FIRST UPPER LOW MOVES OFF INTO THE DAKOTAS AND NE. WILL STILL SEE SOME WRAP AROUND PRECIP OVER THE DVD AND NRN PORTIONS OF THE CWA. TEMPS SHOULD REBOUND NICELY BACK INTO THE 70S OVER THE PLAINS. THE NEXT SYSTEM WILL DROP SWD FROM THE PACNW ON WED...THEN CUTOFF OVER CA THU-SAT...AND SLOWLY MOVE TO THE NE OVER THE WEEKEND. GLOBAL MODELS ARE STILL IN GOOD AGREEMENT THAT THIS SYSTEM WILL TRACK TO OUR NORTH NEXT WEEKEND...ALTHOUGH LATEST RUNS HINT THAT THE TRACK MAY BE A BIT FARTHER SOUTH. STILL LOOKS LIKE MOST OF SE CO WILL BE STUCK IN THE DRY SW FLOW TO THE SOUTH OF THE LOW...BUT GIVEN THE UNCERTAINTIES WILL MAINTAIN POPS OVER THE AREA...ESPECIALLY FOR THE MTS. TEMPS WILL BE CONSIDERABLY LOWER WITH THIS SYSTEM...AS H7 TEMPS ARE MINUS THREE OR LOWER...SO SOME MTN SNOWS SEEM LIKE A GOOD BET. ROSE && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 234 PM MDT SUN MAY 3 2015 VFR CONDITIONS ARE EXPECTED AT THE TAF SITES UNTIL LATE TONIGHT. ISOLATED TO SCATTERED TSTMS MAY MOVE INTO THE VCNTY OF THE TAF SITES THIS EVENING WITH ERRATIC GUSTY WINDS BEING THE MAIN THREAT. LATE TONIGHT IT LOOKS LIKE AT KCOS AN MVFR OR IFR CIG WL DEVELOP AS LOW STRATUS DEVELOPS BEHIND A COLD FRONT. ISOLD SHOWERS AND TSTMS MAY ALSO CONTINUE AT KCOS INTO THE LATE NIGHT HOURS. KPUB COULD ALSO SEE SOME PCPN LATE TONIGHT AND MAYBE EVEN SEE SOME LOW STRATUS MOVE INTO THE VCNTY...HOWEVER CHANCES OF THIS OCCURRING ARE A BIT UNCERTAIN AT THIS TIME. THE LOW STRATUS IS FORECAST TO DISSIPATE BY MID TO LATE MORNING WITH VFR CONDITIONS EXPECTED AT THE TAF SITES ON MONDAY. SHOWERS AND TSTMS ARE ONCE AGAIN A POSSIBILITY AT THE TAF SITES...MAINLY IN THE AFTERNOON HOURS. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...28 LONG TERM...ROSE AVIATION...28
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1255 PM EDT SUN MAY 3 2015 .SYNOPSIS... A LARGE AREA OF HIGH PRESSURE OVER THE EASTERN UNITED STATES TODAY WILL GRADUALLY MOVE OFFSHORE ON MONDAY. A COLD FRONT IS FORECAST TO WEAKEN AS IT DROPS SOUTHWARD ACROSS THE AREA TUESDAY THROUGH EARLY WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK. THE HIGH WILL EVENTUALLY SHIFT OFF THE EAST COAST NEXT WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 12Z UA ANLYS VERY DRY AT 850MB AND 925MB LEVELS IN THE EASTERN CONUS. HAVE TO CLIMB TO 700MB TO FIND SOME APPRECIABLE MOISTURE. 925MB TEMPS IN THE GREAT LAKES AROUND 18C WITH 850MB TEMPS NORTH OF 10C. THAT WILL BE OUR AIR MASS TOMORROW. WE ARE PLANNING NO BIG CHANGES WITH THE NEXT UPDATE. 12Z MODEL DATA EXCEPT FOR THE GFS AND ALL OTHER MESOSCALE MODELS KEEP US DRY INTO THIS EVENING. THE GFS HAS HAD THE HIGHEST .01" ISOHYET WET BIAS (AMONG IT, SREF, NAM AND EC) WI 24HR DURING THE PAST MONTH AND THE LOWEST QPF SKILL SCORE OF ALL THOSE MODELS IN THE NORTHEAST WITH QPF OF LESS THAN .75". THERMALLY IT IS SIMILAR TO YESTERDAY WITH LOCATIONS NW RISING FASTER THAN FORECAST WITH SOME LOCALES LAGGING NEAR THE COAST. OVERALL WE ARE WITHIN ABOUT 3F OF EXPECTATIONS, SO JUST SLIGHT ADJUSTMENTS WILL BE MADE. HIGH PRES WILL BE OVER THE SERN CONUS TODAY. SWLY FLOW WILL INCREASE AND TEMPS WILL WARM IN RESPONSE. HIGHS ARE EXPECTED TO BE IN THE MID TO UPPER 70S, WITH SOME LOCATIONS MAKING A RUN AT 80 DEGREES. NO PRECIP IS ANTICIPATED. THERE WILL BE SOME SCT CLOUDS ON AN OTHERWISE BEAUTIFUL DAY. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... THE AREA OF HIGH PRES WILL MOVE EWD AND OFF THE CST AND A GENLY CLEAR SKY IS IN STORE WITH LIGHT WIND. && .LONG TERM /MONDAY THROUGH SATURDAY/... THE CENTER OF SURFACE HIGH PRESSURE WILL MOVE OFF THE MID-ATLANTIC COAST ON MONDAY. SOUTHWESTERLY RETURN FLOW AROUND THE HIGH WILL DRAW EVEN WARMER AND MORE HUMID AIR UP THE EASTERN SEABOARD. MONDAY WILL CONTEND WITH APRIL 18TH FOR THE WARMEST DAY SO FAR THIS YEAR WITH HIGHS 80-85 DEGREES (EXCEPT COOLER ALONG THE COAST AND IN THE POCONOS). CONDITIONS ACROSS THE FORECAST AREA WILL BE DRY THROUGH MONDAY NIGHT OWING TO STRONG SUBSIDENCE PRESENT BENEATH THE H8 RIDGE. A COLD FRONT WILL MOVE SLOWLY SOUTHWARD THROUGH THE AREA TUESDAY AFTERNOON AND NIGHT. CLOUDS OVERSPREADING NORTHEAST PA AND NORTHWEST NJ WILL RESULT IN SLIGHTLY COOLER HIGHS IN THE 70S ON TUESDAY. FARTHER SOUTH IN THE WARM SECTOR, HIGHS TUESDAY HAVE THE POTENTIAL TO BE CLOSE TO MONDAY`S FROM ABOUT PHILLY SOUTHWARD IF THE FRONT AND ITS ASSOCIATED CLOUD COVER HANGS BACK TO THE NORTH. MOISTURE WILL POOL ALONG THE FRONT AS NOTED BY PWATS INCREASING TO NEAR 1.5 INCHES AND SURFACE DEWPOINTS TO NEAR 60F BY THE AFTERNOON. BUFKIT SOUNDINGS FROM THE 00Z GFS AND 21Z SREF SHOW MODEST INSTABILITY (ML CAPE AROUND 500 J/KG) WHILE THE 00Z NAM DEPICTS A CONSIDERABLY MORE UNSTABLE ENVIRONMENT (ML CAPE AOA 1000 J/KG). WENT MORE CONSERVATIVE WITH FORECAST COVERAGE OF THUNDERSTORMS DUE TO THE PRESENCE OF WEAK SHEAR AND LIMITED FORCING IN ADDITION TO THE QUESTIONABLE INSTABILITY. A GENERAL WEAKENING TREND IS EXPECTED WITH THE CONVECTION AFTER SUNSET, ALTHOUGH SHOWERS MAY LINGER INTO THE OVERNIGHT AS SLIGHTLY BETTER LIFT ASSOCIATED WITH AN UPPER SHORTWAVE TROUGH ARRIVES LATE. THE FRONT MAY EITHER CONTINUE TO SAG SOUTHWARD SLOWLY OR EVEN STALL OVER THE DELMARVA WEDNESDAY MORNING. LIFT ASSOCIATED WITH THE FRONT ITSELF SHOULD WEAKEN AS THE BOUNDARY IS EXPECTED TO BECOME INCREASINGLY DIFFUSE. CONSEQUENTIALLY, COVERAGE OF SHOWERS EXPECTED TO BE RELATIVELY LOW ON WEDNESDAY. THUNDERSTORM CHANCES CONFINED TO THE LOWER DELMARVA, WHERE THESE LOCATIONS HAVE THE BEST CHANCE OF RESIDING IN THE WARM SECTOR TO THE SOUTH OF THE BOUNDARY. THE CAA BEHIND THE FRONT IS NOT SIGNIFICANT, SO THE TREND OF ABOVE NORMAL TEMPS SHOULD CONTINUE INTO WEDNESDAY. HOWEVER, WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF ONSHORE FLOW TO DEVELOP. THIS MAY PREVENT TEMPS FROM REACHING 70F IN THE COASTAL PLAIN, ESPECIALLY THE EASTERLY WIND BECOMES ENHANCED BY A SEABREEZE. EXPANSIVE HIGH PRESSURE OVER THE EASTERN SEABOARD WILL PROVIDE A MAINLY DRY PATTERN THURSDAY THROUGH SATURDAY. THE HUMIDITY IS FORECAST TO INCREASE A BIT FRIDAY AND SATURDAY AS SOUTHERLY RETURN FLOW DEVELOPS WITH THE SURFACE HIGH MOVING OFFSHORE. CANNOT RULE OUT THE POSSIBILITY OF A A SHOWER DEVELOPING DURING THE AFTERNOON HOURS FRIDAY AND SATURDAY BUT THE SUBSIDENCE INVERSION UNDERNEATH THE RIDGE SHOULD MINIMIZE THE CONVECTIVE POTENTIAL. ABOVE NORMAL TEMPS WILL PERSIST WITH HIGHS IN THE 70S TO NEAR 80F EACH DAY. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS. 18Z TAFS WILL BE VFR. THIS AFTERNOON...VERY HIGH BASED (7K) FEW TO SCATTERED CUMULUS CLOUDS EXPECTED. LIGHT WEST WINDS (AROUND 5 KNOTS) ALL TERMINALS PRECEDING ANY SEA/BAY BREEZE FRONTAL PASSAGE. SEA/BAY BREEZE FRONT SHOULD BE FROM LEWES THROUGH CAPE MAY COUNTY, JUST WEST OF KACY AND KBLM AT START OF TAF PERIOD. BY 21Z SHOULD BE WEST OF KGED AND KDOV AND THRU KMIV, MOST OF ATLC COUNTY, SERN BURLINGTON COUNTY AND OCEAN AND MONMOUTH COUNTIES. FROM THERE THE PROGRESS IS EXPECTED TO BE SLOWER PASSING KILG BY 22Z AND REACHING THE DELAWARE RIVER TERMINALS AROUND 00Z. WINDS BEHIND THE FRONT SHOULD AVERAGE SOUTH-SOUTHEAST AT AROUND 10 KNOTS. TONIGHT...CLEAR SKIES AND WINDS BECOMING LIGHT AND VARIABLE. AIR MASS AGAIN IS QUITE CLEAN AND WE ARE NOT ANTICIPATING ANY FOG AT THE TERMINALS. MONDAY...A SOUTHWEST WIND WILL DEVELOP IN THE MORNING AND SHOULD AVERAGE CLOSE TO 10 KNOTS. SOME GUSTINESS IS LIKELY AS THE DAY PROGRESS, MORE LIKELY IN THE AFTERNOON. THE PREDICTED MOISTURE AT THE CUMULUS LEVEL IS SLIGHTLY MORE THAN TODAY, SO MAYBE A FEW MORE HIGH BASED (LOOKS AROUND 7K AGAIN) CUMULUS CLOUDS AGAIN. OUTLOOK... MONDAY AFTERNOON AND MONDAY NIGHT...VFR. SWLY MAY GUST TO 20 KT LATE IN THE DAY. TUESDAY AND TUESDAY NIGHT...PREDOMINATELY VFR. SCT SHRA AND ISO TSRA DURING THE AFTERNOON AND NIGHT COULD YIELD LOCAL MVFR/IFR CONDITIONS. WEDNESDAY...SHRA MAY LINGER INTO WEDNESDAY BUT MOST OF THE TERMINALS SHOULD DRY OUT. SOME MODEL SOLUTIONS ARE INDICATING EASTERLY WINDS TO DEVELOP. WILL HAVE TO WATCH FOR LOW CLOUDS AND MVFR CIGS TO ACCOMPANY MARINE LAYER. WEDNESDAY NIGHT AND THURSDAY...VFR. && .MARINE... SEAS AS OF 10 AM HAVE DROPPED TO 4.6 FEET AT BOTH BUOY9 AND 65. IN ADDITION, THE PERIOD HAS INCREASED TO AROUND 10 SECONDS. WITH THE DOWNWARD TREND UNDERWAY, WE WILL FINALLY PUT THIS SMALL CRAFT ADVISORY IN THE BOOKS AND HAVE NO FURTHER EXTENSION. WE ADJUSTED THE WINDS IN DELAWARE BAY THIS AFTERNOON AND EVE BASED ON HRRR AND ARW MODELS AS THEY HANDLED THE UP THE BAY BREEZE WELL YESTERDAY. NO ADDITIONAL FLAGS ARE EXPECTED DURG THE REMAINDER OF THE NR AND SHORT TERM PDS. OUTLOOK... MONDAY THROUGH THURSDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA. THE STRONGEST WINDS ARE EXPECTED MONDAY AND TUESDAY AS HIGH PRESSURE MOVES OFFSHORE AND A S-SW FLOW AROUND 15-20 KT ENSUES. && .FIRE WEATHER... RELATIVE HUMIDITY VALUES NEAR 30 PERCENT, ALONG WITH OCCASIONAL WIND GUSTS TO NEAR 20 MPH MAY ENHANCE THE FIRE WEATHER RISK LATE IN THE DAY ON MONDAY. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && $$ SYNOPSIS...KLEIN NEAR TERM...GIGI/NIERENBERG SHORT TERM...NIERENBERG LONG TERM...KLEIN AVIATION...GIGI/KLEIN/NIERENBERG MARINE...GIGI/KLEIN/NIERENBERG FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS MIAMI FL
140 PM EDT SUN MAY 3 2015 .AVIATION... VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD. WINDS THIS AFTERNOON WILL CONTINUE TO BE OUT OF THE EAST BETWEEN 15 TO 20 KNOTS WITH HIGHER GUSTS POSSIBLE. WINDS WILL SLIGHTLY SUBSIDE DURING THE OVERNIGHT HOURS, HOWEVER, THEY ARE EXPECTED TO INCREASE TO 15 TO 20 KNOTS AGAIN ON MONDAY MORNING WITH HIGHER GUSTS ONCE AGAIN POSSIBLE. && .PREV DISCUSSION... /ISSUED 954 AM EDT SUN MAY 3 2015/ UPDATE... THE CURRENT MODEL ANALYSIS SHOWS MOSTLY ZONAL FLOW ACROSS THE FLORIDA PENINSULA WITH A VERY WEAK MID LEVEL TROUGH OVER SOUTH FLORIDA. AT THE SURFACE, A BROAD AREA OF HIGH PRESSURE EXISTS ACROSS THE SOUTHEAST STATES CENTERED FROM WEST VIRGINIA TO NORTHERN GEORGIA. THE MID LEVEL TROUGH IS REFLECTED WELL ON THE 12Z MFL SOUNDING SHOWING A NORTH-NORTHEAST WIND IN THE LAYER FROM 600MB TO 450MB WITH WESTERLY FLOW ABOVE AND BELOW THAT. LOW LEVEL FLOW IS EAST-NORTHEAST WITH THE HIGH PRESSURE CENTERED TO THE NORTH. THE SURFACE HIGH WILL RAPIDLY SHIFT EAST TODAY IN RESPONSE TO A COLD FRONT THAT WILL MOVE INTO THE CENTRAL PORTION OF THE CONTINENTAL U.S. WITH THE PRESSURE GRADIENT TIGHTENING ACROSS SOUTH FLORIDA BY EARLY THIS AFTERNOON. THIS WILL KEEP THE HIGH RISK OF RIP CURRENTS AT THE ATLANTIC BEACHES WITH MIAMI BEACH OCEAN RESCUE ALREADY REPORTING STRONG CURRENTS THIS MORNING. THE 12Z SOUNDING ALSO SHOWS A VERY STABLE AIRMASS LAYER BETWEEN 850MB AND 750MB SO THIS WILL CONTINUE TO KEEP RAIN CHANCES OUT OF THE FORECAST ALTHOUGH THE HRRR IS INDICATING THE POSSIBILITY OF A COUPLE OF QUICK PASSING SHOWERS. HOWEVER, IT IS ONLY DEPICTING 20-25 DBZ INTENSITY SO NOT WORTH MENTIONING AT THIS TIME AND THE HRRR OFTEN TIMES OVER EMPHASIZES SHOWERS IN A DRY EASTERLY FLOW REGIME. BUT STILL, SOMETHING TO MONITOR. FOR THE MARINE FORECAST, DO NOT PLAN ANY CHANGES AT THIS TIME. HOWEVER, THE LATEST GFS MODEL GUIDANCE IS SHOWING A TAD BIT STRONGER WINDS OVER THE ATLANTIC WATERS THIS AFTERNOON THAN IS CURRENTLY DEPICTED. DUE TO THIS BEING FROM THE INTERMEDIATE RUN AT 06Z AND ONLY ONE UPDATE SHOWING THIS, WILL WAIT FOR THE 12Z RUN TO MAKE ANY DECISIONS BUT MAY NEED TO BUMP UP THE WIND TO 20 KNOTS FROM THE CURRENT 15-20 KNOTS WHICH COULD AFFECT THE SIGNIFICANT WAVE HEIGHTS AS WELL AND MAY NEED TO BEGIN THE SCA FOR THOSE WATERS EARLIER THAN THE 00Z START NOW. KOB PREV DISCUSSION... /ISSUED 744 AM EDT SUN MAY 3 2015/ AVIATION... MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE EARLY MORNING HOURS AND THROUGH THE AFTERNOON WITH MAINLY STABLE WEATHER CONDITIONS ANTICIPATED. AS HIGH PRESSURE BUILDS...EAST NORTHEAST WINDS FORECAST TO INCREASE TO THE 15 TO 20 KNOTS RANGE BY LATE MORNING WITH HIGHER GUSTS POSSIBLE AND SUBSIDING OVERNIGHT BUT STILL REMAINING AROUND 10-15 KTS EXCEPT AROUND 10 KNOTS AT APF AND TMB. PREV DISCUSSION... /ISSUED 433 AM EDT SUN MAY 3 2015/ DISCUSSION... THE REGIONAL SYNOPTIC FEATURES EARLY THIS MORNING INCLUDE A WEAK SURFACE TROUGH JUST WEST OF THE KEYS AND EXTENDING NORTHWARD...A MID TO UPPER LEVEL TROUGH EXTENDING INTO THE CENTRAL TO EASTERN GULF AND A COLD FRONT ACROSS EASTERN CUBA THAT EXTENDS NORTHWARD TO A SURFACE LOW NORTHEAST OF THE MID-ATLANTIC STATES. FOR TODAY...HIGH PRESSURE WILL SLOWLY DEVELOP OFF THE GEORGIA/CAROLINAS COAST WITH THE AFOREMENTIONED SURFACE TROUGH ERODING. IN ADDITION DEEPER LAYERED MOISTURE WILL LIKELY REMAIN ACROSS THE KEYS TODAY. WITH HIGHER PRESSURE BUILDING INTO THE REGION THE WEST COAST SEA BREEZE WILL BE SUPPRESSED AND WITH PWAT EXPECTED TO BE AROUND ONLY AN INCH CONVECTION IS NOT LIKELY TODAY ALTHOUGH SOME ISOLATED SHOWER ACTIVITY IS POSSIBLE ACROSS THE SOUTHERN TIP OF THE PENINSULA. THERE WILL BE A HIGH RISK OF RIP CURRENTS ALONG THE ATLANTIC COAST BEACHES TODAY AND TONIGHT WITH A LONG PERIOD NORTHEASTERLY SWELL IN THE 2 TO 4 FOOT RANGE FORECAST TO ENTER THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY THIS MORNING...WITH THE GREATEST IMPACT EXPECTED ACROSS THE WATERS TO THE EAST OF PALM BEACH COUNTY. FOR MONDAY...MOISTURE AND CLOUDINESS WILL BEGIN TO RETURN TO THE REGION. THE MID TO UPPER LEVEL TROUGH ACROSS THE GULF IS FORECAST TO DEEPEN WITH THE FLORIDA PENINSULA TO THE EAST OF THE TROUGH AXIS. THE LOW LEVEL FLOW WILL BECOME SOUTHERLY BRINGING DEEP MOISTURE ACROSS CUBA NORTHWARD INTO THE REGION. MODERATE EASTERLY WINDS WILL FAVOR SHOWERS AND A SLIGHT CHANCE OF THUNDERSTORMS MAINLY ALONG THE EASTERN THIRD OF THE PENINSULA AND THE ADJACENT ATLANTIC WATERS. FOR TUESDAY...PREVIOUS DISCUSSIONS HAVE ALREADY INDICATED THAT DEEP TROPICAL MOISTURE IS FORECAST TO ENTER ON TUESDAY WITH THE MID TO UPPER LEVEL TROUGH AXIS JUST WEST OF FLORIDA AND A BROAD LOW LEVEL TROUGH DEVELOPING ACROSS THE FLORIDA STRAITS AND EXTENDING INTO THE NORTHWEST BAHAMAS. THE PWAT IS FORECAST TO BE ABOUT 1.7 INCHES AND MID LEVEL TEMPERATURES FORECAST TO BE SIGNIFICANTLY COOL FOR THIS TIME OF YEAR...ABOUT 3 DEGREES COOLER. ALL THESE FACTORS ARE FORECAST TO BRING SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS TO THE REGION ON TUESDAY WITH A SYNOPTIC PATTERN SUPPORTIVE OF LOCALLY HEAVY RAINFALL WITH FLOODING POTENTIAL POSSIBLE IN ISOLATED AREAS. BY WEDNESDAY THE GLOBAL MODELS START TO DIVERGE SOME IN THEIR SOLUTIONS BUT THE GFS ENSEMBLE SHOWS BROAD FEATURES THAT SEEM LIKE A GENERAL CONSENSUS BETWEEN THE GFS AND THE ECMWF. THE ENSEMBLE INDICATES THAT THE UPPER LEVEL TROUGH AXIS IS FORECAST TO SHIFT EAST ACROSS THE FLORIDA PENINSULA WITH A BROAD LOW LEVEL AND SURFACE TROUGH OFF THE EAST CENTRAL FLORIDA COAST WITH DEEP MOISTURE EXTENDING ACROSS SOUTH FLORIDA. SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST WITH A SYNOPTIC PATTERN AGAIN SUPPORTIVE OF LOCALLY HEAVY RAINFALL. FOR THE EXTENDED FORECAST...BY THURSDAY THE ECMWF...GFS AND THE GFS ENSEMBLE HAVE BROAD AGREEMENT THAT THE UPPER LEVEL TROUGH WILL PERSIST NEAR THE FLORIDA PENINSULA WITH A CLOSED SURFACE LOW FORECAST OFF THE NORTHEAST FLORIDA COAST. THE GUIDANCE GENERALLY SUGGESTS THAT THE LOW COULD SLOWLY DRIFT TO THE NORTHWEST INTO NEXT WEEKEND. OBVIOUSLY ITS TOO EARLY TO SPECULATE ON THIS SCENARIO AND WHAT IF ANY IMPACT IT MIGHT HAVE FOR SOUTH FLORIDA AND WILL HAVE TO WAIT AND SEE WHAT CONSENSUS THE GUIDANCE HAS DURING THIS WEEK. MARINE... A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE GULF WATERS FOR WINDS TO NEAR 20 KNOTS OR JUST ABOVE THROUGH 10 AM. WINDS ARE FORECAST TO SLOWLY DECREASE TODAY THEN INCREASE AGAIN TO 20 KNOTS OR JUST ABOVE MAINLY ACROSS THE OFF SHORE WATERS. THEREFORE THE SMALL CRAFT ADVISORY WILL BE ALLOWED TO EXPIRE THIS MORNING BUT A NEW ONE WILL BE ISSUED FOR TONIGHT...STARTING AT 00Z FOR THE OFF SHORE GULF WATERS. WITH THE COMBINATION OF NORTHEASTERLY WINDS IN THE 15 TO 20 KNOT RANGE ACROSS THE ATLANTIC WATERS AND A LONG PERIOD NORTHEASTERLY SWELL IN THE 2 TO 4 FOOT RANGE FORECAST TO ENTER THE ATLANTIC WATERS EAST OF PALM BEACH COUNTY LATER THIS MORNING...HAZARDOUS SEAS TO NEAR 7 FEET ARE FORECAST ACROSS THE ATLANTIC WATERS WITH A SMALL CRAFT ADVISORY IN EFFECT TODAY STARTING AT 18Z THROUGH 00Z TUESDAY BUT MAY HAVE TO BE EXTENDED WITH LATER GUIDANCE. THERE IS A LOT OF UNCERTAINTY IN THE EXTENDED FORECAST GIVEN THE UNCERTAINTIES OUTLINED IN THE DISCUSSION ABOVE. SO THERE COULD BE CONSIDERABLE CHANGES TO THE WIND AND WAVES FORECAST IN THE EXTENDED PERIODS IN THE NEXT FEW DAYS. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 69 82 73 78 / 0 20 60 70 FORT LAUDERDALE 71 82 73 80 / 10 20 70 70 MIAMI 70 82 72 81 / 10 20 70 70 NAPLES 63 86 67 86 / 10 10 20 60 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...HIGH RIP CURRENT RISK UNTIL MIDNIGHT EDT TONIGHT FOR FLZ168-172- 173. AM...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM EDT MONDAY FOR AMZ650-651-670-671. GM...SMALL CRAFT ADVISORY FOR WINDS FROM 8 PM THIS EVENING TO 8 AM EDT MONDAY FOR GMZ676. && $$ SHORT TERM...52/PS LONG TERM....52/PS AVIATION...55/CWC
AREA FORECAST DISCUSSION
NWS LINCOLN IL
256 PM CDT SUN MAY 3 2015 .SHORT TERM...(TONIGHT) ISSUED AT 250 PM CDT SUN MAY 3 2015 A WEAKENING SHORT WAVE OVER EASTERN IA AND NW IL BY MS RIVER WILL LIFT INTO SE WI BY SUNSET AND KEEP BEST CHANCES OF SHOWERS AND THUNDERSTORMS NORTH OF I-80 THROUGH SUNSET WITH JUST ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS OVER THE IL RIVER VALLEY. CHANCES OF SHOWERS AND THUNDERSTORMS WILL INCREASE DURING THE NIGHT ESPECIALLY OVERNIGHT OVER THE IL RIVER VALLEY WITH SLIGHT CHANCES EXTENDING AS FAR SE AT CHARLESTON/MATTOON BY SUNRISE MONDAY AS YET ANOTHER SHORT WAVE OVER EASTERN NEBRASKA TRACKS EAST TOWARD THE IA/IL BORDER BY 12Z/7 AM MONDAY. SPC KEEPS RISK OF SEVERE STORMS NW OF IL OVER NORTHERN IA, SE MN AND INTO CENTRAL WI THROUGH DAYBREAK MONDAY WHERE BETTER FORCING WILL BE AS COLD FRONT PUSHES SE INTO CENTRAL PARTS OF WI/IA BY SUNRISE MONDAY. STAYED CLOSE TO MET/MAV GUIDANCE LOWS TONIGHT IN THE UPPER 50S AND LOWER 60S WITH COOLEST READINGS IN EASTERN/SE IL. BREEZY SSW WINDS 15-25 MPH THIS AFTERNOON WILL DIMINISH SOUTH 7-14 MPH AFTER SUNSET. && .LONG TERM...(MONDAY THROUGH SUNDAY) ISSUED AT 250 PM CDT SUN MAY 3 2015 MAIN FORECAST CHALLENGE WILL BE POSITION OF FRONTAL BOUNDARY AND HIGHER RAIN CHANCES LATER TONIGHT THRU MONDAY NIGHT. REMNANTS OF TODAY`S MCV SHOULD PUSH OFF TO OUR NORTHEAST PUSHING THE SHOWERS EVEN FURTHER AWAY FROM THE FORECAST AREA THIS EVENING. WEAK UPPER LEVEL DISTURBANCE OVER THE MISSOURI VALLEY HAS A FEW SHOWERS ASSOCIATED WITH IT BUT THE LAST FEW RUNS OF THE RAP AND HRRR HAVE BACKED OFF SOME ON ANY ORGANIZED SHOWER AND THUNDERSTORM THREAT WITH THAT FEATURE. IT STILL APPEARS OUR MAIN THREAT WILL COME LATER TONIGHT AND THRU THE MORNING HOURS OF MONDAY WITH REDEVELOPMENT TAKING PLACE LATER TOMORROW AFTERNOON INTO THE EVENING RIGHT ALONG THE STALLED FRONTAL BOUNDARY. HAVE TRENDED MORE TOWARDS THE HIGH RESOLUTION MODEL SOLUTIONS FROM THE NSSL-ARW AND 4KM NAM-WRF WITH RESPECT TO FRONTAL POSITION ON MONDAY AND ASSOCIATED PRECIP CHANCES ALONG IT. THE HIGHER POPS WILL REMAIN ACROSS THE NORTHERN HALF OF THE FORECAST AREA BEFORE THE BOUNDARY SHIFTS BACK NORTH LATE TUESDAY INTO WEDNESDAY AS UPPER LEVEL RIDGING BUILDS ACROSS THE REGION. SEVERE THREAT WILL BE TIED TO THE POSITION OF THE BOUNDARY MONDAY AFTERNOON AND EVENING WITH THE NAM-WRF INDICATING A 40-45 KT LOW LEVEL JET SETTING UP TONIGHT FROM NORTHERN MISSOURI NORTHEAST INTO NORTHERN IL WITH THE STRONGER 850 MB THETA-E ADVECTION AND MOISTURE TRANSPORT LOCATED FROM NORTHEAST MISSOURI INTO NORTHERN IL. STORMS SHOULD DEVELOP WELL OUT TO OUR WEST AND NORTHWEST LATER THIS EVENING AND THEN TRANSLATE EAST AND SOUTHEAST INTO OUR NORTHERN AREAS BY LATE EVENING OR DURING THE EARLY MORNING HOURS OF MONDAY. IF A DECENT COLD POOL DEVELOPS LATER TONIGHT...THOSE STORMS MAY TRACK FURTHER SOUTH AND AFFECT THE POSITION OF THE SYNOPTIC SCALE BOUNDARY IN OUR AREA ON MONDAY/MONDAY EVENING. WITH THE WEST TO EAST BOUNDARY LOCATED ACROSS A PORTION OF THE FORECAST AREA MONDAY AFTERNOON AND EVENING...LOOK FOR STORMS TO FIRE AGAIN ALONG THE INSTABILITY AXIS WHICH SHOULD BE ALIGNED FROM NORTHERN MISSOURI INTO WEST CENTRAL IL BY MID AFTERNOON. MIXED LAYER CAPES OF 1500-2000 J/KG AND EFFECTIVE SHEAR VALUES OF 25 KTS SHOULD PROMOTE STORM ORGANIZATION WITH ISOLATED STRONG WIND GUSTS AND HAIL POSSIBLE WITH 700-500 MB LAPSE RATES OF 6.5-7 DEG/C DEPICTED ON SOUNDINGS TOMORROW AFTERNOON ACROSS THE NORTH. SCATTERED STORMS SHOULD CONTINUE MONDAY NIGHT AND THEN BEGIN TO EDGE NORTHWARD BY TUESDAY AS THE UPPER LEVEL RIDGING BEGINS TO AMPLIFY ACROSS THE MIDWEST. ONCE THE 500 MB RIDGE BUILDS OVER THE AREA ON TUESDAY...SHOWER AND THUNDERSTORM CHANCES WILL SHIFT NORTH CLOSER TO THE RETREATING SURFACE BOUNDARY. OUR NEXT THREAT WILL BE ASSOCIATED WITH A LEAD SHORTWAVE TROF THAT IS FORECAST TO EJECT NORTHEAST INTO THE SOUTHERN AND CENTRAL PLAINS ON THURSDAY WITH THE HIGHEST POPS...AT LEAST INITIALLY...ACROSS THE WEST AS MODELS SUGGEST MOST OF THE STRONGER LIFT AND INSTABILITY WILL SHIFT MORE NORTH THAN EAST. HOWEVER...OUR AREA WILL BE UNDER A SOUTHWEST FLOW ALOFT LATE IN THE WEEK AND INTO NEXT WEEKEND WITH A DEEPER UPPER LEVEL LOW FORECAST BY MEDIUM RANGE MODELS TO PUSH OUT OF THE PLAINS AND INTO THE MIDWEST BY LATE IN THE WEEKEND. UNFORTUNATELY...THIS TYPE OF A PATTERN THIS TIME OF YEAR BRINGS DAILY CHANCES FOR SHOWERS AND STORMS BUT AT LEAST THE TEMPERATURES WILL REMAIN ABOVE NORMAL. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1255 PM CDT SUN MAY 3 2015 VFR CONDITIONS GENERALLY EXPECTED TO CONTINUE ACROSS THE CENTRAL IL AIRPORTS NEXT 24 HOURS THROUGH 18Z/1 PM MONDAY DUE TO UPPER LEVEL RIDGE INTO THE MID MS RIVER VALLEY. SCATTERED TO BROKEN MID/HIGH CLOUDS TO OCCUR AT TIMES THROUGH MONDAY MORNING. FEW TO SCATTERED CUMULUS CLOUDS 5-8 KFT APPEARING THIS AFTERNOON AND COULD GO BROKEN AT TIMES TONIGHT INTO MID MONDAY MORNING. VCSH AT PIA THIS AFTERNOON WHILE BRUNT OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON STAY NORTH OF I-80 AS WEAKENING SHORT WAVE IN EASTERN IA LIFT ACROSS NORTHERN IL AND SE WI THROUGH SUNSET. CARRIED VCSH SHOWERS AT PIA AND BMI THIS EVENING THOUGH BEST CHANCES AGAIN TO THE NW PER HIGH RES MODELS LIKE HRRR AND RAP. A LITTLE BETTER CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS FROM 09Z-15Z ESPECIALLY AT NORTHERN AIRPORTS OF BMI AND PIA AS ANOTHER SHORT WAVE TRACKS EASTWARD FROM IA INTO THE IL RIVER VALLEY BY 15Z/MON. BREEZY SSW WINDS 13-18 KTS WITH GUSTS OF 20-27 KTS THIS AFTERNOON TO DIMINISH SOUTH CLOSER TO 10 KTS AFTER SUNSET AND BECOME SW 10-13 KTS WITH GUSTS 15-20 KTS AFTER 15Z/MONDAY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...07 LONG TERM...SMITH AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1256 PM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 1045 AM CDT SUN MAY 3 2015 FORECAST WAS UPDATED TWICE THIS MORNING TO ADDRESS THE SMALL CHANCES OF SHOWERS AND ISOLATED THUNDERSTORMS OVER NORTHERN COUNTIES TODAY AND HANDLING CLOUD COVER. HAVE 20% CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON MAINLY NW OF I-55 WITH 30% CHANCE FAR NORTHERN COUNTIES OF KNOX, STARK AND MARSHALL COUNTIES. SCATTERED SHOWERS OVER SE IA INTO NW IL JUST NW OF ILX CWA WAS TRACKING ENE AHEAD OF ANOTHER WEAK SHORT WAVE OVER CENTRAL IA THAT WILL WEAKEN A LIFT INTO NE IL THIS AFTERNOON KEEPING BETTER CHANCES OF CONVECTION NORTH OF CENTRAL IL REST OF TODAY. IL RIVER VALLEY WILL BE ON SOUTHERN EDGE OF THIS WEATHER SYSTEM TO HAVE SMALL CHANCES OF CONVECTION THERE. TEMPS AT 1030 AM HAVE WARMED INTO THE UPPER 60S TO MID 70S AND WARM HIGHS IN THE LOWER 80S EXPECTED BY 4 PM TODAY ACROSS MUCH OF THE AREA. BREEZY SOUTHWEST WINDS OF 15 TO 25 MPH AND PARTLY TO MOSTLY SUNNY SKIES. && .SHORT TERM...(TODAY) ISSUED AT 338 AM CDT SUN MAY 3 2015 SURFACE TROUGH AND FRONTAL BOUNDARY REMAIN WELL OFF TO THE NORTHWEST THIS MORNING...DRAPED FROM SD NORTHEAST THROUGH MN. THIS WILL BECOME THE FOCUS FOR CONVECTIVE ACTIVITY LATER TODAY AS IT MOVES CLOSER TO CENTRAL IL IN THE LATE AFTERNOON. THIS MORNING A SHORTWAVE EVIDENT ON WATER VAPOR IMAGERY OVER CENTRAL IL CONTINUES TO PRODUCE A FEW SHOWERS...EXPECTED TO MOVE EASTWARD AND DISSIPATE LATER THIS MORNING IN EAST CENTRAL IL ACCORDING TO LATEST HRRR RUN. ANOTHER SHORTWAVE OVER WEST IA IS EXPECTED TO TRACK ENE AND PASS BY THE CENTRAL IL FORECAST AREA TO THE NORTH. WITH GENERAL SUBSIDENCE INDICATED ACROSS THE AREA...HAVE KEPT THE FORECAST DRY LATE MORNING THROUGH LATE AFTERNOON/EARLY EVENING ONCE THE INITIAL ROUND OF MORNING SHOWERS PASSES THROUGH. LOW LEVEL SOUTHERLY FLOW WILL KEEP THE WARMING TREND GOING FOR TODAY WITH HIGHS REACHING AROUND 80 DEGREES. FORECAST SOUNDINGS INDICATE BOUNDARY LAYER MOMENTUM CAPABLE OF PRODUCING GUSTS 20-25 MPH FROM I-70 NORTHWARD...WITH SUSTAINED SOUTHERLY WINDS 12-18 MPH. .LONG TERM...(TONIGHT THROUGH SATURDAY) ISSUED AT 338 AM CDT SUN MAY 3 2015 NOT A LOT OF CHANGES IN THE FORECAST. MAJORITY OF FORECAST REVOLVES AROUND A SLOWING/STALLED FRONTAL BOUNDARY ACROSS THE REGION FOR TONIGHT AND THROUGH TOMORROW BEFORE BEING EDGED TO THE NORTH BEFORE ANOTHER SYSTEM SPINS UP OVER THE PLAINS AND MOVES INTO THE REGION. FOR TONIGHT, THE FRONTAL BOUNDARY SETTLING IN JUST TO THE NORTHWEST WILL PROVIDE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS FOR THE AREA...SETTLING INTO THE NORTHERN HALF OF THE STATE AND BECOMING HUNG UP IN QUASI ZONAL FLOW ALOFT. BEST CHANCES FOR PRECIP REMAIN IN THE NORTHERN HALF OF THE STATE PROVIDING SOME FOCUS FOR STORM DEVELOPMENT. MODELS HAVE TRENDED A LITTLE MORE SCATTERED IN THE QPF FIELDS, ALTHOUGH THE NORTHERN HALF OF THE STATE STILL SEEMS PRIMED FOR THE BEST CHANCES OF PRECIP THROUGH MONDAY NIGHT, SPECIFICALLY THE AREAS WHERE THE BOUNDARY STALLS. SPC HAS KEPT THE NORTHERN HALF OF THE CWA IN A MARGINAL RISK FOR STORMS INVOF THE BOUNDARY ON MONDAY. CLUSTERS OF STORMS NEAR A WEAK BOUNDARY LOOKING BORDERLINE AT THIS POINT, BUT IN AN AREA OF CONTINUING WARM AIR ADVECTION PROVIDING POTENTIAL INSTABILITY JUST SOUTH OF THE BOUNDARY THAT WILL SLOWLY BE SETTLING SOUTH INTO THE WARMER AND MORE BUOYANT AIR. A RIDGE BEGINS TO BUILD INTO THE MIDWEST FROM THE SOUTHEAST...WITH ENOUGH SUBSIDENCE IN THE REGION OF THE RIDGE AXIS TO ERODE SHOWER CHANCES AT LEAST TUES NIGHT THROUGH WED NIGHT. ANOTHER PATTERN SHIFT TAKES HOLD FOR THE LATER HALF OF THE WEEK, SETTING UP MORE OF A SOUTHWESTERLY FLOW AND AN ACTIVE WEATHER PATTERN AGAIN AS WAVES CONTINUE TO RIPPLE AROUND THE SWRN LOW AND INTO THE MIDWEST. A RATHER WET FORECAST OVERALL, WITH SEVERAL DIFFERENT PATTERNS ESTABLISHING THEMSELVES...AND KEEPING SHOWERS AND THUNDERSTORMS IN THE OUTLOOK. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1255 PM CDT SUN MAY 3 2015 VFR CONDITIONS GENERALLY EXPECTED TO CONTINUE ACROSS THE CENTRAL IL AIRPORTS NEXT 24 HOURS THROUGH 18Z/1 PM MONDAY DUE TO UPPER LEVEL RIDGE INTO THE MID MS RIVER VALLEY. SCATTERED TO BROKEN MID/HIGH CLOUDS TO OCCUR AT TIMES THROUGH MONDAY MORNING. FEW TO SCATTERED CUMULUS CLOUDS 5-8 KFT APPEARING THIS AFTERNOON AND COULD GO BROKEN AT TIMES TONIGHT INTO MID MONDAY MORNING. VCSH AT PIA THIS AFTERNOON WHILE BRUNT OF SHOWERS AND ISOLATED THUNDERSTORMS THIS AFTERNOON STAY NORTH OF I-80 AS WEAKENING SHORT WAVE IN EASTERN IA LIFT ACROSS NORTHERN IL AND SE WI THROUGH SUNSET. CARRIED VCSH SHOWERS AT PIA AND BMI THIS EVENING THOUGH BEST CHANCES AGAIN TO THE NW PER HIGH RES MODELS LIKE HRRR AND RAP. A LITTLE BETTER CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS FROM 09Z-15Z ESPECIALLY AT NORTHERN AIRPORTS OF BMI AND PIA AS ANOTHER SHORT WAVE TRACKS EASTWARD FROM IA INTO THE IL RIVER VALLEY BY 15Z/MON. BREEZY SSW WINDS 13-18 KTS WITH GUSTS OF 20-27 KTS THIS AFTERNOON TO DIMINISH SOUTH CLOSER TO 10 KTS AFTER SUNSET AND BECOME SW 10-13 KTS WITH GUSTS 15-20 KTS AFTER 15Z/MONDAY. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...07 SHORT TERM...ONTON LONG TERM...HJS AVIATION...07
AREA FORECAST DISCUSSION
NWS GOODLAND KS
234 PM MDT SUN MAY 3 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 224 PM MDT SUN MAY 3 2015 EARLY AFTERNOON WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW WESTERLY FLOW IN PLACE ACROSS THE PLAINS WITH A SHORTWAVE TROUGH UPSTREAM OVER THE CENTRAL ROCKIES. AT THE SURFACE A TROUGH IS CURRENTLY IN PLACE OVER THE CWA...WITH A COLD FRONT NEAR IMPERIAL NEBRASKA EXTENDING INTO NORTHEAST COLORADO. REGIONAL RADAR SHOWS SCATTERED THUNDERSTORM ACTIVITY ALREADY MOVING OFF THE HIGHER TERRAIN IN COLORADO AND MOVING OFF THE PALMER DIVIDE TOWARDS THE WESTERN PART OF OUR CWA. THIS AFTERNOON-TONIGHT...WINDOW FOR SEVERE WEATHER APPEARS TO BE MAINLY AHEAD OF COLD FRONT WHERE MODELS HAD BEEN ADVERTISING MODERATE INSTABILITY DEVELOPING BY 00Z (MAINLY EAST OF SURFACE TROUGH). SO FAR RAP ANALYSIS SHOWS ML CAPE GENERALLY AROUND 500 J/KG LIKELY DUE TO MUCH LOWER TD VALUES AHEAD OF COLD FRONT THAN PREVIOUSLY ANTICIPATED. HRRR/RAP HAVE BEEN SHOWING ISOLATED DEVELOPMENT ALONG SURFACE TROUGH AXIS WHERE CAP HAS BEEN WEAKENED. THERE IS A WINDOW FOR INCREASING SHEER AS COLD FRONT MOVES SOUTH AND DEPENDING ON STRENGTH OF UPDRAFTS WE COULD SEE SOME ORGANIZED CELLS...OTHERWISE IT APPEARS TO BE AN ENVIRONMENT FAVORING PULSE TYPE THUNDERSTORMS THROUGH MOST OF THE NIGHT. DCAPE VALUES IN EXCESS OF 1000 J/KG DO RAISE CONCERNS FOR MICROBURST POTENTIAL AHEAD OF COLD FRONT SO EVEN WEAKER UPDRAFTS COULD PRODUCE NEAR SEVERE OR SEVERE WINDS AS THEY COLLAPSE. SHOWER AND THUNDERSTORM COVERAGE WILL INCREASE LATE THIS EVENING ALONG/NORTH OF COLD FRONT WITH INCREASING MOISTURE RETURN AND ELEVATED CAPE IN PLACE. BY LATE TONIGHT INSTABILITY BEGINS TO WANE...WHILE LARGE SCALE FORCING STARTS TO SHIFT NORTH AND EAST OF THE REGION. THIS IS WHERE MODELS DIVERGE WITH NAM CONTINUING TO INDICATE AND LULL OR DRY PERIOD WHILE ECMWF/GFS INDICATE POSSIBLE OVERRUNNING OR STRATUS/FOG/DRIZZLE DEVELOPMENT ALONG/NORTH OF THE FRONT. TOUGH CALL AND WHILE I HEDGED TOWARD THE DRY NAM AT 12Z...I COULD SEE IN THIS TYPE OF PATTERN A LIGHT PRECIP/DRIZZLE EVEN EVOLVING BY MONDAY MORNING. MONDAY...UPPER LOW OVER THE SOUTHWEST US BEGINS TO DEEPEN AND MOVE EAST WITH BETTER LARGE SCALE FORCING SPREADING OVER THE CWA BY LATE AFTERNOON. DEPENDING ON WHAT HAPPENS TO POSSIBLE STRATUS DURING THE DAY WE MAY OR MAY NOT HAVE A WINDOW FOR SEVERE THUNDERSTORMS IN THE EASTERN PART OF OUR CWA WHERE MODELS SHOW WAA AND INCREASING TDS/INSTABILITY. FURTHER NORTH AND WEST STRATUS IS MORE LIKELY TO LINGER...HOLDING TEMPS DOWN IN AND ANY INSTABILITY WOULD BE ELEVATED AND WEAKER. DEPENDING ON CHOICE IN MODEL SHOWERS/THUNDERSTORMS COULD BE POSSIBLE THROUGH THE DAY...HOWEVER BETTER CHANCES SHOULD BE TIED TO STRONGER LARGE SCALE FORCING LATER DURING THE DAY MONDAY. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 224 PM MDT SUN MAY 3 2015 SOUTHWEST FLOW WILL PRECEDE AN UPPER TROUGH THAT WILL AFFECT THE CENTRAL PLAINS TUESDAY THROUGH WEDNESDAY. SURFACE HIGH PRESSURE WILL SHIFT EAST ACROSS THE CENTRAL PLAINS MONDAY NIGHT AS LOW PRESSURE MOVES INTO COLORADO TUESDAY. LOW PRESSURE WILL REMAIN OVER COLORADO AND WESTERN KANSAS THROUGH WEDNESDAY. POPS WILL INCREASE FROM MONDAY EVENING TO OVERNIGHT AS BETTER DYNAMICS AND MOISTURE MOVE NORTH INTO THE FA. PLAN TO GO WITH CHANCE POPS ACROSS THE WESTERN PORTION OF THE FA DURING THE EVENING WITH LIKELY POPS OVER THE SOUTHEAST ZONES CLOSER TO THE SURFACE BOUNDARY. LIKELY POPS WILL SPREAD NORTH ACROSS THE FA OVERNIGHT AS VERY FAVORABLE MOISTURE AND LIFT MOVE INTO THE FA. LIKELY AND DEFINITE POPS WILL BE USED ACROSS THE ENTIRE FA TUESDAY AND TUESDAY EVENING AS GOOD DYNAMICS AND MOISTURE CONTINUE TO STREAM NORTHWARD ACROSS THE FA. PRECIPITABLE WATER VALUES ARE AROUND AN INCH SO WILL INCLUDE MODERATE RAIN IN THE GRIDS TUESDAY. POPS WILL START DECREASING TO CHANCE POPS AFTER 06Z WEDNESDAY AS THE UPPER TROUGH STARTS TO LIFT OUT OF THE AREA. SOME LIKELY POPS WILL STILL EXIST ACROSS THE NORTHERN FA WEDNESDAY AFTERNOON AS INSTABILITY INCREASES. MIN TEMPERATURES MONDAY NIGHT SHOULD COOL TO THE MID 40S IN EASTERN COLORADO AND THE MID 50S IN THE EASTERN FA. MIN TEMPERATURES TUESDAY NIGHT WILL RANGE FROM THE LOWER TO MID 50S. MAX TEMPERATURES TUESDAY SHOULD RANGE FROM 65 TO 70 AND 70 TO 75 WEDNESDAY. IN THE EXTENDED...(WEDNESDAY NIGHT THROUGH SUNDAY)...THE UPPER TROUGH LIFTS NORTHEAST WEDNESDAY NIGHT WITH SOUTHWEST FLOW FOLLOWING THROUGH SATURDAY. THE NEXT UPPER TROUGH MOVES INTO THE PLAINS SATURDAY NIGHT AND SUNDAY. SHORTWAVES MOVING THROUGH THE FLOW AND INCREASING DYNAMICS WITH THE NEXT TROUGH SATURDAY NIGHT AND SUNDAY WILL KEEP AT LEAST A CHANCE OF THUNDERSTORMS ACROSS THE FA EACH DAY. MIN TEMPERATURES THROUGH SATURDAY NIGHT SHOULD RANGE FROM 45 TO 55. MAX TEMPERATURES WILL GENERALLY RANGE FROM THE MID 60S TO THE MID 70S. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1132 AM MDT SUN MAY 3 2015 SCATTERED THUNDERSTORMS SHOULD DEVELOP THIS AFTERNOON ALONG SURFACE TROUGH WITHIN VICINITY OF BOTH KGLD AND KMCK...WITH BETTER COVERAGE LATE AFTERNOON AND EVENING. A COLD FRONT WILL DROP SOUTH OVERNIGHT WITH INSTABILITY DECREASING LEADING TO TRANSITION TO MAINLY LIGHT SHOWERS LATE...WITH A LULL IN ACTIVITY BY MONDAY MORNING POSSIBLE. SOME GUIDANCE SHOWS LIGHT PRECIP AND LOW STRATUS DEVELOPING NORTH OF THIS FRONT AND CONTINUING TO IMPACT BOTH KGLD AND KMCK AFTER 11-13Z PERIOD THROUGH MIDDAY MONDAY. THERE IS QUITE A BIT OF SPREAD IN GUIDANCE AFTER 09Z...SO CONFIDENCE IS LOW. CONDITIONAL CLIMATOLOGY FAVORS AT LEAST IFR CIGS WITH EASTERLY FLOW/LOW LEVEL MOISTURE INCREASING NORTH OF THE FRONT. I INTRODUCED 2000-2500 CIG GROUPS FOR MONDAY MORNING AS A START AS I WOULD RATHER NOT GO AS LOW AS IFR AT THIS TIME CONSIDERING LEVEL OF CONFIDENCE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...FS AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
329 PM CDT Sun May 3 2015 .SHORT TERM...(This Evening through Monday) Issued at 328 PM CDT SUN MAY 3 2015 Zonal but weak flow aloft continues over the Central Plains between northern and southern branches with a few weak waves moving through. Appears moderate mid-level isentropic lift combined with one of these waves to spark overnight convection, with another wave keeping isolated showers going in eastern Kansas into the early afternoon. High- based nature of this activity keeping much precip from what there is in check however. Water vapor imagery suggesting a stronger wave rotating northeast out of eastern New Mexico with convection firing ahead of it into southeastern Colorado. Cold front was from northwestern Kansas into northeastern Nebraska early this afternoon with a few cumulus along it in central Nebraska. Dewpoints have dropped to around 40F in southwest Kansas with thermal ridge ahead of front pushing temp at CNK to near record levels. Precipitation chances remain the main challenge through Monday afternoon. Recent HRRR and RAP runs continue to attempt to produce convection along the front, but have been too fast to do so. With low levels rather dry to the west, the main player with convection to the west and south could be via the New Mexico wave, or other convective-induced waves from eastern Colorado. Isentropic upglide looks less impressive than this morning but some is again present and could be enough to continue or even produce convection into east central Kansas late this evening and into much of Monday. Other prime scenario for convection seems to be with eventual convection generated in eastern Nebraska sinking south into northeast Kansas on decent 850mb moisture convergence as a moderate low level jet veers with time. This could linger well into Monday morning, and with the earlier possibilities as well, have kept chance PoPs going into the morning Monday, with lesser confidence in precip in the northwest counties nearer the drier low level air. Details in precip activity Monday afternoon will be largely impacted by the earlier activity, but models increase low level moisture further, though NAM likely a bit aggressive again, with CAPE possibly near 2000 J/kg ahead of any outflow or front/effective front. Shear values again look meager to support much severe weather but some potential remains. Have kept highs cooler than today with more cloud/precip/moisture anticipated. .LONG TERM...(Monday Night through Sunday) Issued at 328 PM CDT SUN MAY 3 2015 Models continue to show an active pattern for Monday night through Sunday as they dig another closed low into the southwestern U.S. by the end of the work week. This causes mid level flow to remain from the southwest while gulf moisture continues advecting north. So there looks to be plenty of moisture available with occasional forcing mechanisms passing overhead such that there is a chance for precip in every period of the forecast. The one period with the lowest chance for precip remain Tuesday. There seems to be agreement among the models that shortwave ridge will propagate over eastern KS with some relatively dryer air moving in. Therefore have a dry forecast for northeast and east central KS. North central KS may be close enough to shortwave energy lifting north through the high plains that have kept a small chance for the western counties for Tuesday. The best chance for showers and thunderstorms appears to be late Tuesday night and Wednesday as a well defined shortwave is progged to lift across northeast KS. There are some minor differences in timing of the vort max lifting out. Nevertheless with little or no inhibition to convection expect showers and thunderstorms to overspread the area and have increased POPs into the 70 to 80 percent range. Wednesday night through Saturday does not look like it will be constant precip, but the pattern makes it difficult to say when chances are better than not. With occasional low amplitude waves within the southwest flow and a moist airmass remaining in place, the forecast has a chance for precip each day. There are even some signs of a weak frontal boundary moving into the forecast on Friday which may help focus moisture and provide some lift. Otherwise think chances could be on the increase for Saturday night and Sunday as the upper low begins to lift out of the southern Rockies. Because the GFS is a little further north and doesn`t have as much shortwave energy rotating through the southern plains, have kept POPs in the chance category for now. There should not be any big swings in temps through the period due to the persistent pattern. If anything there may be a slight cool down for Wednesday expecting cloud cover and precip to limit heating. Otherwise temps should be seasonable with lows around 60 and highs in the mid 70s to near 80 && .AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon) Issued at 1229 PM CDT SUN MAY 3 2015 The main aviation concern for the afternoon will be the strong and gusty southerly winds. These will diminish around sunset. Winds likely strong enough overnight to minimize the possibility of wind shear conditions. With the frontal system just off to the North of the terminals, there is some suggestion that KMHK, KTOP/KFOE terminals could at least see some VCSH or perhaps VCTS, but this would be high based and confidence is to low at this point to carry in the TAFs. This is something to stay tuned to though if planning transit to or from the terminals. && .TOP WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...65 LONG TERM...Wolters AVIATION...Drake
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1237 PM CDT Sun May 3 2015 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 346 AM CDT SUN MAY 3 2015 Isolated thunderstorms developed this morning shortly after 06Z in warm/moist advection within the low level jet. Vad wind profiles as well as water vapor imagery shows a mid level wave around 700 mb moving across central Kansas at 08Z. Latest runs of the HRRR and RAP move the isolated convection east into Missouri by 12Z-13Z. After this early morning round of convection, the rest of the day should be dry with clouds gradually decreasing through the early afternoon hours. Deep mixing today along with warm advection will yield highs in the low to mid 80s. Main thermal axis sets up from New Mexico through north central Kansas into northeast Nebraska today. Winds will increase by mid morning as pressure gradient increases. Surface front moves southeast into western Kansas this afternoon while it moves little across Nebraska. Expect afternoon heating out west will overcome convective inhibition for scattered storms to develop. These will remain to the west of north central Kansas into the early evening hours. Models eject weak waves northeast across western Kansas into southern Nebraska overnight. Expect convection to fire along the front in Nebraska tonight with outflow pushing south into north central and northeast Kansas. Southerly low level jet will help to develop scattered showers and thunderstorms overnight. Shear is marginal 20 to 30 kts overnight with MUCAPE 800-1000 J/kg. Expect some strong storms are possible with a few severe storms not out of the question later this evening across north central Kansas. Hail and winds will be the main hazards. Lows tonight will be mild with readings in the lower 60s. .LONG TERM...(Monday through Saturday) Issued at 346 AM CDT SUN MAY 3 2015 A wet pattern looks to be setting up for this upcoming week with several chances for precipitation all the way into next weekend. By Monday, a mid-level ridge will stretch across the Southern Plains and southeastern U.S. with a surface low centered over southwest Kansas. Models show the associated cold front extending into north central Kansas and southeast Nebraska, however the last few models runs have shown this front becoming fairly stationary over northern Kansas Monday into Monday night, limiting the southeastern extent of precipitation chances across the CWA. As a result, have continued to diminish PoPs across far east central Kansas through that period with likely PoPs along the KS/NE border with the stationary boundary. There continues to be the potential for some strong to severe thunderstorms to develop along this stationary boundary Monday afternoon into Monday evening as storms should be surface-based due to little to no inhibition present. The NAM continues to be the most aggressive with the amount of available moisture, thus increasing the parameters for severe thunderstorms. However, CAPE values could reach upwards of 1000-2000 J/kg with decent low-level lapse rates. However, 0-6km bulk shear continues to look fairly weak with most models showing upwards of only about 30kts. The main concern with any strong to severe storms will likely be some large hail and potentially some locally heavy rain as thunderstorms may train across north central Kansas into the evening and overnight hours with the low-level jet looking to be parallel to the boundary. The mid-level ridge should stretch further northward into the Central Plains Monday night into Tuesday, helping to push the cold front northward into Nebraska and further limiting the precipitation potential across the southeastern portions of the forecast area. At this time, Tuesday looks to show the best potential for being dry across much of the forecast area. However, focus quickly shifts to the southwest where a mid-level trough will be beginning to lift northeastward across the High Plains through Wednesday and into the Northern Plains by Wednesday night. At the surface, a low pressure system will strengthen across the High Plains but looks to become anchored over that region through mid to late week, resulting in persistent southerly surface winds advecting warm, moist air into the region. The combination of this steady stream of moisture and a frontal boundary that will likely remain hung up just west of the forecast area through much of the remainder of the week will help to support continued scattered shower and thunderstorm chances through the end of the week. While there is decent model agreement with the timing and tracking of the mid-level trough and the development of weak embedded waves within the pattern by late week, there is less agreement with the surface features in when the associated cold front will become tilted enough to move into the forecast area during the latter part of the week. Due to the low confidence in this boundary placement, have lowered PoPs some from the consensus blend but still have chance PoPs in for the entire forecast area through Saturday. This fairly stationary surface pattern should result in fairly similar temperatures throughout the week with highs in the 70s/near 80, lows in the upper 50s/low 60s, and dewpoints in the 50s and 60s. && .AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon) Issued at 1229 PM CDT SUN MAY 3 2015 The main aviation concern for the afternoon will be the strong and gusty southerly winds. These will diminish around sunset. Winds likely strong enough overnight to minimize the possibility of wind shear conditions. With the frontal system just off to the North of the terminals, there is some suggestion that KMHK, KTOP/KFOE terminals could at least see some VCSH or perhaps VCTS, but this would be high based and confidence is to low at this point to carry in the TAFs. This is something to stay tuned to though if planning transit to or from the terminals. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...53 LONG TERM...Hennecke AVIATION...Drake
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1211 PM CDT SUN MAY 3 2015 ...UPDATED SYNOPSIS AND AVIATION DISCUSSION... .SYNOPSIS... ISSUED AT 1207 PM CDT SUN MAY 3 2015 AT 12Z SUNDAY AN UPPER LEVEL TROUGH/LOW WAS LOCATED JUST OFF THE SOUTHERN CALIFORNIA COAST WITH WEAK UPPER LEVEL RIDGING OCCURRING OVER THE SOUTHERN AND CENTRAL PLAINS. FURTHER NORTH AN UPPER LEVEL TROUGH WAS CROSS THE NORTHERN PLAINS. AT 12Z SUNDAY A 700MB TROUGH WAS LOCATED OVER WESTERN KANSAS WITH A THERMAL RIDGE AXIS EXTENDING FROM SOUTHEAST COLORADO INTO THE PANHANDLE OF TEXAS. A SURFACE COLD FRONT STRETCHED FROM EASTERN WYOMING, ACROSS NEBRASKA, TO SOUTHWEST MINNESOTA. JUST SOUTH OF THIS COLD FRONT A A SURFACE TROUGH EXTENDED FROM NORTH CENTRAL NEBRASKA INTO THE TEXAS PANHANDLE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 320 AM CDT SUN MAY 3 2015 THE MAIN CONCERN FOR THE SHORT TERM IS CONVECTIVE CHANCES, COVERAGE, AND STRENGTH FOR LATE THIS AFTERNOON INTO THE EVENING. ON THE SYNOPTIC SCALE, A RATHER WEAK WEST-TO-EAST FLOW WAS FOUND IN THE MID AND UPPER TROPOSPHERE, WITH 500MB FLOW AVERAGING ABOUT 15 TO 20 KNOTS ACROSS THE CENTRAL ROCKIES AND PLAINS WITH 250MB FLOW NOT MUCH STRONGER AT 25 TO 30 KNOTS. THIS IS MORE LIKE A LATE JUNE/EARLY JULY FLOW REGIME. AS A RESULT, THE CONVECTION THAT IS EXPECTED TO DEVELOP LATE THIS AFTERNOON WILL BEHAVE MORE LIKE LATE JUNE/JULY STORMS: SLOW MOVING, AND MARGINAL-AT-BEST SEVERE WEATHER PROSPECTS. THUNDERSTORMS WILL DEVELOP IN THE DEEPLY MIXED AIRMASS THAT WILL DEVELOP ALONG AND WEST OF THE LEE TROUGH AXIS/NEBULOUS DRYLINE. THE CONVERGENCE WILL NOT BE ALL THAT STRONG, BUT THE LOWER TO MID TROPOSPHERIC LAPSE RATES OF EARLY MAY WILL BE STEEP ENOUGH SUCH THAT EVEN WEAK CONVERGENCE WILL AID IN THUNDERSTORM DEVELOPMENT ALONG THE WEAK DRYLINE/LEE TROUGH. WHEN COMPARED AGAINST THE GFS, ECMWF, AND WRF-ARW, THE NAM12/NMMB SURFACE DEWPOINTS APPEAR TO BE TOO AMBITIOUS WITH MID 50S DEWPOINTS AS FAR WEST AS HIGHWAY 283 BY LATE AFTERNOON, RESULTING IN LARGE AREA OF 2000+ J/KG SBCAPE. THERE WILL LIKELY BE A BIT MORE MIXING THAN WHAT THE NAM12 SHOWS WITH TEMPERATURES WARMING WELL INTO THE MID TO UPPER 80S AND THE LACK OF ANY EASTERLY COMPONENT WIND. THAT SAID, THE EARLY RUNS OF THE RAP13 AND HRRR APPEAR TO BE WHACKED OUT WITH SURFACE FLOW TOO VEERED OUT/WESTERLY COMPONENT WITH DEWPOINTS TANKING INTO THE UPPER 30S TO AROUND 40F FOR ALL OF SOUTHWEST KANSAS. BELIEVE THAT SOMETHING IN THE MIDDLE IS MORE REALISTIC IN TERMS OF WHAT WILL REALLY PAN OUT WITH THE SURFACE SETUP LATE THIS AFTERNOON. NEVERTHELESS, 1000 TO 1500 J/KG SBCAPE SHOULD BE REALIZED AHEAD OF THE DEVELOPING CONVECTION THIS AFTERNOON. THE GREATEST THREAT FROM ANY OF THE STORMS WILL BE SOME LOCALIZED DOWNBURST WIND GUSTS IN EXCESS OF 50 KNOTS/58 MPH GIVEN THE ANTICIPATED HIGH TEMPERATURE- DEWPOINT SPREADS APPROACHING 40F LATE THIS AFTERNOON. THE HAIL RISK LOOKS QUITE LOW GIVEN THE POOR CAPE-SHEAR COMBINATION AND LACK OF ANY UPPER TROPOSPHERIC FLOW TO SUPPORT MID-UPPER STORM-RELATIVE SHEAR. THE STRONGEST STORM WILL STILL BE CAPABLE OF QUARTER TO PERHAPS HALF-DOLLAR SIZE HAIL, THOUGH. THE FORECAST POPS OF 40 TO 50 PERCENT WILL COVER AREAS ALONG AND BETWEEN THE HIGHWAY 83 AND 283 CORRIDOR, INCLUDING SCOTT CITY, GARDEN, LIBERAL, NESS CITY, WAKEENEY, AND HAYS. ANTICIPATED SLOW STORM MOTIONS WILL RESULT IN LOCALIZED HEAVY RAINFALL, ESPECIALLY DURING THE EVENING WHEN UPSCALE GROWTH OCCURS BETWEEN 00-03Z. LOSS OF DIURNAL HEATING WILL LIKELY RESULT IN THE DEMISE OF CONVECTION BY 06Z MUCH LIKE WE HAVE SEEN OVER THE PAST COUPLE NIGHTS OUT ALONG THE KS-CO BORDER. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 320 AM CDT SUN MAY 3 2015 AN UPPER LEVEL LOW IS EXPECTED TO MOVE INTO THE DESERT SOUTHWEST SUNDAY INTO MONDAY THEN WEAKEN INTO AN OPEN WAVE AND CURLS NORTHEASTWARD INTO THE CENTRAL ROCKIES BY TUESDAY INTO TUESDAY NIGHT. THIS FEATURE THEN MOVES INTO THE CENTRAL PLAINS WEDNESDAY THEN INTO THE NORTHERN PLAINS THURSDAY. MOISTURE ABOVE WESTERN KANSAS WILL INCREASE AS THIS FEATURE APPROACHES LEADING TO INCREASING CLOUDS MONDAY WITH MOSTLY CLOUDY SKIES EXPECTED MONDAY NIGHT THROUGH TUESDAY NIGHT. A FRONTAL BOUNDARY AT THE SURFACE IS ANTICIPATED TO SPRAWL OUT ACROSS WEST CENTRAL KANSAS MONDAY THEN SHIFT NORTHWARD MONDAY NIGHT INTO TUESDAY AS A WARM FRONT. WINDS AHEAD OF THIS BOUNDARY WILL GENERALLY BE FROM A SOUTHERLY DIRECTION WITH WINDS BEHIND THIS BOUNDARY FROM MORE OF A NORTHERLY DIRECTION. A DOME OF HIGH PRESSURE WILL BE LOCATED ACROSS THE EASTERN UNITED STATES WITH TRAJECTORIES ON THE WEST SIDE BRINGING UP COPIOUS AMOUNTS OF MOISTURE FROM THE GULF INTO THE CENTRAL PLAINS. AS FOR PRECIPITATION CHANCES, THUNDERSTORMS MAY BE POSSIBLE ACROSS CENTRAL KANSAS MONDAY MORNING BUT SHOULD QUICKLY MOVE OUT OF THE CWA BY LATE MORNING. ADDITIONAL THUNDERSTORMS ARE PROGGED TO DEVELOP ACROSS WESTERN KANSAS IN THE AFTERNOON AND SPREAD ACROSS THE REMAINDER OF THE AREA MONDAY NIGHT. A FEW STORMS COULD BECOME STRONG TO SEVERE ACROSS CENTRAL KANSAS DEPENDING ON HOW MUCH HEATING OCCURS DURING THE DAY. RAIN CHANCES BECOME LIKELY TUESDAY AS MOISTURE CONTINUES TO BE PULLED UP FROM THE GULF AND PWAT`S SURPASS AN INCH. MEANWHILE, AN UPPER LEVEL LOW ENTERS THE WESTERN UNITED STATES TUESDAY THEN SLIDES SOUTHWARD INTO THE DESERT SOUTHWEST BY THURSDAY. THIS LOW THEN CURLS NORTHEAST INTO THE CENTRAL ROCKIES FRIDAY THEN INTO THE NORTHERN ROCKIES WEEKEND. WEAK SHORTWAVES ARE EXPECTED TO MOVE AROUND THE PERIPHERY OF THIS SYSTEM AND TOWARDS THE CENTRAL PLAINS FOR THE REMAINDER OF THE WEEK. THIS WILL ALLOW PRECIPITATION CHANCES TO CONTINUE ACROSS THE AREA WITH THE BEST CHANCE OF BENEFICIAL RAINFALL ACROSS CENTRAL AND SOUTH CENTRAL KANSAS. AS FOR TEMPERATURES, HIGHS MONDAY LOOK TO RANGE FROM THE LOWER 70S ACROSS WEST CENTRAL KANSAS WHERE THE FRONTAL BOUNDARY WILL BE LOCATED TO LOWER 80S ACROSS SOUTH CENTRAL KANSAS. HIGHS TUESDAY ARE ANTICIPATED TO BE AROUND 70 DEGREES. LOWS MONDAY NIGHT AND TUESDAY NIGHT ARE PROGGED TO RANGE FROM AROUND 50 DEGREES ACROSS FAR WESTERN KANSAS TO AROUND 60 DEGREES ACROSS CENTRAL AND SOUTH CENTRAL KANSAS. HIGHS FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND ARE EXPECTED TO BE IN THE UPPER 70S TO LOWER 80S WITH LOWS RANGING FROM AROUND 50 DEGREES ACROSS FAR WESTERN KANSAS TO AROUND 60 DEGREES ACROSS CENTRAL AND SOUTH CENTRAL KANSAS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1207 PM CDT SUN MAY 3 2015 A SURFACE BOUNDARY WILL REMAIN NEARLY STATIONARY TODAY ACROSS WESTERN KANSAS TODAY. GIVE THE LOCATION OF THIS SURFACE BOUNDARY THE WINDS TODAY WILL AVERAGE LESS THAN 10 KNOTS. AFTER SUNSET THE PREVAILING WINDS WILL BECOME SOUTHEAST AT 10 TO 15 KNOTS. SCATTERED THUNDERSTORMS ARE ALSO EXPECTED TO DEVELOP ALONG AND EAST OF THIS SURFACE BOUNDARY LATE TODAY AND THEN CONTINUE THROUGH EARLY TONIGHT. BUFR SOUNDINGS KEEP CLOUD BASES WITH THESE STORMS AT OR ABOVE 5000FT AGL SO VFR CONDITIONS ARE EXPECTED WITH THESE STORMS. SOME OF THESE STORMS EARLY THIS EVENING WILL BE CAPABLE OF PRODUCING QUARTER SIZE HAIL AND WIND GUSTS OF 50 TO 60 MPH. AT THIS TIME THE THUNDERSTORMS WILL BE MORE LIKELY AT GCK BETWEEN 23Z SUNDAY AND 02Z MONDAY. AT DDC AND HAY FROM 02Z TO 06Z. && .PRELIMINARY POINT TEMPS/POPS... DDC 88 58 80 57 / 30 30 50 70 GCK 88 55 78 55 / 40 40 60 90 EHA 88 54 75 53 / 30 20 60 80 LBL 90 57 79 56 / 40 50 60 90 HYS 88 58 78 57 / 40 50 60 60 P28 86 60 81 59 / 10 20 20 40 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BURGERT SHORT TERM...UMSCHEID LONG TERM...HOVORKA_42 AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1234 PM CDT SUN MAY 3 2015 .AVIATION...HIGH PRESSURE RIDGING IN FROM JUST OFF THE CAROLINAS PROVIDING A LIGHT ANTICYCLONIC ONSHORE FLOW. MAINLY HIGH BASED FAIR WX CU WITH SOME ENHANCEMENT BETWEEN LCH AND LFT ON VISIBLE IMAGERY. SHORTWAVE ENERGY AROUND BPT AND AEX DUE PARTIALLY TO SOME UPPER DIVERGENCE AND HRRR IMPLIES ISOLD SHOWERS A POSSIBLILITY BUT WILL LEAVE OUT OF THE TAFS AS COVERAGE WOULD BE TOO SPARSE TO WORRY ABOUT. CONTINUED VFR. SWEENEY && .PREV DISCUSSION... /ISSUED 1058 AM CDT SUN MAY 3 2015/ DISCUSSION... FORECAST IS GENERALLY ON TRACK THIS MORNING. LATEST HIGH RESOLUTION MODELS POINT TWD THE POTENTIAL FOR ISOLD -RW ACROSS THE AREA IN RESPONSE TO INCREASING MSTR...A WEAK SHORTWAVE PUSHING EAST FROM TX...AND WEAK LL CONVERGENCE. SATELLITE IMAGERY AND A QUICK LOOK OUTSIDE REVEALS MOSTLY FLAT CU...THOUGH SOME VERTICAL DEPTH WAS NOTED OFF TO THE EAST/SE. KLCH/KPOE 88DS HAVE SHOWN SOME BRIEF LIGHT SHOWERS AS WELL. WITH ALL OF THIS IN MIND...INTRODUCED A LOW POP ALONG WITH ISOLATED SHOWERS TO THE FCST FOR TODAY. REMAINING GRIDS LOOK FINE WITH ONLY MINOR ADJUSTMENTS MADE. 13 PREV DISCUSSION... /ISSUED 410 AM CDT SUN MAY 3 2015/ DISCUSSION... EARLY MORNING SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER THE TENNESSEE VALLEY KEEPING A LOW-LEVEL SRLY FLOW IN PLACE OVER THE REGION. MEANWHILE WATER VAPOR IMAGERY SHOWS WEAK RIDGING IN PLACE FROM THE WRN GULF UP THROUGH THE SRN PLAINS. SATELLITE IMAGERY AND SFC OBS INDICATE LITTLE CLOUDINESS OVERHEAD ATTM...WHILE REGIONAL 88DS ARE ACCORDINGLY PPINE. ONE MORE DRY DAY LOOKS ON TAP FOR THE FORECAST AREA AS THE RIDGE ALOFT HOLDS FIRM. SEASONAL TEMPS IN THE LOWER 80S SHOULD BE THE RULE FOR THE AFTERNOON. OVER THE EARLY PART OF THE COMING WEEK THE NEXT PACIFIC STORM SYSTEM ALOFT MOVING ASHORE ALONG THE WEST COAST WILL GIVE A PUSH TO THE RIDGE...EVENTUALLY SHOVING IT TO THE SERN CONUS. IN THE MEANTIME A WEAK ERLY WAVE IS PROGGED TO SLIP PAST THE REGION ON MONDAY...ALLOWING FOR WIDELY SCATTERED SHOWERS OR STORMS TO DEVELOP BY AFTERNOON/EVENING. THEREAFTER SMALL POPS...MAINLY DAYTIME...LINGER THROUGH THE REMAINDER OF THE FORECAST AS THE PACIFIC SYSTEM GRADUALLY OPENS AND LIFTS THROUGH THE WRN CONUS AND PLAINS STATES...USHERING IN A SERIES OF WEAK DISTURBANCES ACROSS THE WRN GULF STATES. MARINE... AN ONSHORE FLOW...THOUGH SOMETIMES MORE ERLY...WILL LINGER THROUGH THE PERIOD WITH HIGH PRESSURE CENTERED OVER THE SERN CONUS AND OFF THE SRN ATLANTIC COAST. A TIGHTENING GRADIENT WITH LOW PRESSURE DEVELOPING OVER THE SRN PLAINS WILL ALLOW FOR AT LEAST CAUTION-CRITERIA WINDS BY LATE TUESDAY. && .PRELIMINARY POINT TEMPS/POPS... AEX 82 58 82 63 / 20 10 20 10 LCH 81 61 82 66 / 20 0 20 20 LFT 82 61 81 64 / 20 10 30 20 BPT 83 63 83 67 / 20 0 10 20 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ AVIATION...11
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
340 PM EDT SUN MAY 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 505 AM EDT SUN MAY 3 2015 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION. UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50. A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR 10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND 1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS INTO THE MID TO UPPER 70S OVER THE WEST HALF. THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING. LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K- 10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER SOUTH. EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY 06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 300 PM EDT SUN MAY 3 2015 THE MODELS INDICATE THAT THE NRN STREAM ZONAL FLOW WILL GIVE WAY TO RIDGING OVER THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH DEVELOPING OVER THE WRN CONUS. BY LATE IN THE WEEK...SHORTWAVES EMERGING FROM THE SW CONUS AND CNTRL PLAINS WILL HELP TO FLATTEN THE RIDGE AND BRING AN INCREASING POTENTIAL FOR PCPN INTO THE WRN GREAT LAKES. TEMPS ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH MUCH OF THE PERIOD. HIGH PRES WILL DOMIMATE KEEPING CONDITIONS DRY MON NIGHT THROUGH TUE. WITH PWATS DROPPING DOWN BLO .25 INCH AND LIGHT WINDS EXPECTED UNDER THE SFC HIGH...MIN TEMPS MON NIGHT COULD VERY WELL DROP BELOW FREEZING AT SEVERAL OF THE TYPICAL INLAND COLD SPOTS. EXPECT TEMPS TO REBOUND ON TUESDAY AND MAYBE BE A FEW DEGREES WARMER THAN MONDAY/S READINGS...WITH HIGHS IN THE 60S AND LOWER 70S...WARMEST WEST. COOLER READINGS IN THE 50S CAN BE EXPECTED NEAR THE GREAT LAKES...ESPECIALLY NEAR LAKE MICHIGAN WITH DEVELOPING LIGHT SE FLOW ON BACKSIDE OF SFC RIDGE AXIS. TUE NIGHT-WED NIGHT...INCLUDED SOME LOW POPS FOR SHRA OVER MAINLY WEST HALF (ESPECIALLY ALONG THE WI BORDER) WHICH MAY DEVELOP LATE TUE NIGHT INTO WED ALONG AN 850 MB WARM FRONT LIFTING SLOWLY NNE FROM THE UPPER MS VALLEY AND AHEAD OF A STRENGTHENING 850 MB JET NOSING INTO THE WRN GREAT LAKES. TEMPS WILL BEGIN TO INCREASE WED WITH WAA BUT THERE COULD BE SOME WAA CLOUDS AROUND TO KEEP TEMPS DOWN A BIT. MODELS SUGGEST A LULL IN PCPN WED NIGHT AS 850 MB WARM FRONT LIFTS NORTH OF THE AREA AND WRN GREAT LAKES REGION BECOMES CAPPED BY WARMER/DRIER AIR ALOFT. THU-FRI...TEMPS SHOULD REALLY CLIMB THU ALONG WITH INCREASING GULF MOISTURE IN STRENGTHENING SRLY FLOW AHEAD OF A PLAINS SFC TROUGH THAT WILL EDGE TOWARD THE UPPER MS VALLEY. LAYER PWATS INCREASE FROM NEAR 1.5 INCHES WEST TO 1.25 INCHES EAST. MODELS STILL DIFFER ON TIMING OF COLD FRONTAL PASSAGE LATE IN THE WEEK WITH THE 00Z ECMWF 12-18 HRS FASTER THAN EITHER THE 12Z GFS OR 12Z CANADIAN MODEL. 00Z ECMWF HAS FRONT MOVING THROUGH LATE THU NIGHT AND FRI WHILE THE 12Z GFS/CANADIAN SHOW A FRONTAL TIMING OF FRI ATFERNOON AND FRI NIGHT. ALL MODELS SHOW INCREASING PCPN CHANCES OVER THE WEST HALF THU AFTERNOON SPREADING INTO THE EAST HALF THU NIGHT AHEAD OF APPROACHING FRONTAL BOUNDARY. MOST OF THE MODELS SHOW SHRA/TSRA HANGING AROUND ON FRIDAY WITH ECMWF SHOWING FRONTAL PASSAGE TAKING PLACE AND GFS/CANADIAN SHOWING FRONTAL BOUNDARY APPROACHING THE WRN CWA. FRI NIGHT-SATURDAY...MODEL DIFFERENCES WILL HAVE BIGGEST IMPACT ON FCST TOWARD NEXT WEEKEND. IF 00Z ECMWF VERIFIES THEN FRI NIGHT AND SAT WILL BE MOSTLY DRY AND COOLER IN WAKE OF FRONTAL PASSAGE. THE 12Z SLOWER GFS AND CANADIAN SOLN WITH FRONT WOULD WARRANT KEEPING SHRA/TSRA CHCS IN FOR AT LEAST THE CENTRAL AND ERN FCST AREA FRI NIGHT AND MAYBE EVEN LINGERING INTO SAT MORNING. GFS AND CANADIAN WOULD THEN ARGUE FOR DRIER/COOLER CONDITIONS SAT AFTERNOON INTO SAT NIGHT AS HIGH PRES BUILDS IN FM THE NW IN THE WAKE OF THE FRONTAL PASSAGE. GIVEN POOR MODEL AGREEMENT WILL PROBABLY EMPLOY A BLEND OF FCST GUIDANCE FOR POPS DURING THIS PERIOD. NEXT SUNDAY...AGAIN MODEL DIFFERENCES WILL PROBABLY ARGUE FOR USING A BLEND OF MODEL GUIDANCE BY DAY 7 FCST. THIS WOULD WARRANT A DRY FCST FOR MUCH OF THE CWA ESPECIALLY CENTRAL AND EAST STILL UNDER INFLUENCE OF CANADIAN HIGH PRES OVER AREA. THE ECMWF SHOWS SYSTEM DEVELOPING OVER CENTRAL PLAINS AND TRIES TO DEVELOP PCPN ALONG THE WI BORDER COUNTIES IN STRENGTHENING WAA PATTERN OUT AHEAD OF IT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 151 PM EDT SUN MAY 3 2015 EXPECT MAINLY VFR CEILINGS/VIS THROUGH THE PERIOD. THE ONLY EXCEPTION WILL BE IF AND WHEN TS ENTER THE AREA. SHOWERS AND ISOLATED TS ACTIVITY ACROSS CENTRAL MN WILL CONTINUE TO EDGE NE...WITH ADDITIONAL SHOWERS AND TS DEVELOPMENT ALONG THE NEARING COLD FRONT STRETCHING FROM SE ACROSS CENTRAL MANITOBA TO NEAR THE W LAKE SUPERIOR SHORELINE...AND THROUGH CENTRAL MN. LOOK FOR THE BEST CHANCE FOR TS DEVELOPMENT AT IWD 20-22Z. WHILE SAW WILL HAVE A CHANCE OF TS AROUND 23Z...IT WAS LESS LIKELY...SO LEFT VCTS OUT OF THE TAF FOR THEM. DRY HIGH PRESSURE ROLLING INTO E MT AND THE DAKOTAS THIS AFTERNOON WILL QUICKLY BUILD IN BEHIND THE FRONT. THE RESULT WILL BE A CLEAR/MOSTLY CLEAR BY DAYBREAK MONDAY IF NOT EARLIER. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 339 PM EDT SUN MAY 3 2015 OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD. A LOW OVER S HUDSON BAY WILL MOVE INTO FAR N QUEBEC TONIGHT AND DRAG A TROUGH/COLD FRONT OVER LAKE SUPERIOR...WITH SHOWER AND THUNDERSTORMS...AND THE POTENTIAL FOR AREAS OF FOG. FOG WILL LINGER INTO MONDAY OVER THE E HALF OF LAKE SUPERIOR. IN THE WAKE OF THE TROUGH...HIGH PRESSURE WILL BUILD OVER THE UPPER LAKES FROM THE W-NW ON MONDAY. EXPECT THIS HIGH TO DRIFT INTO SE ONTARIO LATER TUESDAY INTO WEDNESDAY...AS ANOTHER AREA OF HIGH PRESSURE MOVES INTO NW ONTARI...AND A LOW TAKES SHAPE OVER THE PLAINS. A LOW PRESSURE CENTER EMERGING FROM THIS TROUGH WILL MOVE THROUGH THE N PLAINS ON THURSDAY WHILE THE ONTARIO HIGH DRIFTS ACROSS HUDSON BAY INTO QUEBEC. THE LOW WILL DRAG A TROUGHACROSS THE UPPER GREAT LAKES REGION THURSDAY NIGHT THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...VOSS AVIATION...KF MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
300 PM EDT SUN MAY 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 505 AM EDT SUN MAY 3 2015 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION. UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50. A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR 10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND 1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS INTO THE MID TO UPPER 70S OVER THE WEST HALF. THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING. LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K- 10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER SOUTH. EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY 06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 300 PM EDT SUN MAY 3 2015 THE MODELS INDICATE THAT THE NRN STREAM ZONAL FLOW WILL GIVE WAY TO RIDGING OVER THE WRN GREAT LAKES DOWNSTREAM FROM A TROUGH DEVELOPING OVER THE WRN CONUS. BY LATE IN THE WEEK...SHORTWAVES EMERGING FROM THE SW CONUS AND CNTRL PLAINS WILL HELP TO FLATTEN THE RIDGE AND BRING AN INCREASING POTENTIAL FOR PCPN INTO THE WRN GREAT LAKES. TEMPS ARE EXPECTED TO REMAIN ABOVE NORMAL THROUGH MUCH OF THE PERIOD. HIGH PRES WILL DOMIMATE KEEPING CONDITIONS DRY MON NIGHT THROUGH TUE. WITH PWATS DROPPING DOWN BLO .25 INCH AND LIGHT WINDS EXPECTED UNDER THE SFC HIGH...MIN TEMPS MON NIGHT COULD VERY WELL DROP BELOW FREEZING AT SEVERAL OF THE TYPICAL INLAND COLD SPOTS. EXPECT TEMPS TO REBOUND ON TUESDAY AND MAYBE BE A FEW DEGREES WARMER THAN MONDAY/S READINGS...WITH HIGHS IN THE 60S AND LOWER 70S...WARMEST WEST. COOLER READINGS IN THE 50S CAN BE EXPECTED NEAR THE GREAT LAKES...ESPECIALLY NEAR LAKE MICHIGAN WITH DEVELOPING LIGHT SE FLOW ON BACKSIDE OF SFC RIDGE AXIS. TUE NIGHT-WED NIGHT...INCLUDED SOME LOW POPS FOR SHRA OVER MAINLY WEST HALF (ESPECIALLY ALONG THE WI BORDER) WHICH MAY DEVELOP LATE TUE NIGHT INTO WED ALONG AN 850 MB WARM FRONT LIFTING SLOWLY NNE FROM THE UPPER MS VALLEY AND AHEAD OF A STRENGTHENING 850 MB JET NOSING INTO THE WRN GREAT LAKES. TEMPS WILL BEGIN TO INCREASE WED WITH WAA BUT THERE COULD BE SOME WAA CLOUDS AROUND TO KEEP TEMPS DOWN A BIT. MODELS SUGGEST A LULL IN PCPN WED NIGHT AS 850 MB WARM FRONT LIFTS NORTH OF THE AREA AND WRN GREAT LAKES REGION BECOMES CAPPED BY WARMER/DRIER AIR ALOFT. THU-FRI...TEMPS SHOULD REALLY CLIMB THU ALONG WITH INCREASING GULF MOISTURE IN STRENGTHENING SRLY FLOW AHEAD OF A PLAINS SFC TROUGH THAT WILL EDGE TOWARD THE UPPER MS VALLEY. LAYER PWATS INCREASE FROM NEAR 1.5 INCHES WEST TO 1.25 INCHES EAST. MODELS STILL DIFFER ON TIMING OF COLD FRONTAL PASSAGE LATE IN THE WEEK WITH THE 00Z ECMWF 12-18 HRS FASTER THAN EITHER THE 12Z GFS OR 12Z CANADIAN MODEL. 00Z ECMWF HAS FRONT MOVING THROUGH LATE THU NIGHT AND FRI WHILE THE 12Z GFS/CANADIAN SHOW A FRONTAL TIMING OF FRI ATFERNOON AND FRI NIGHT. ALL MODELS SHOW INCREASING PCPN CHANCES OVER THE WEST HALF THU AFTERNOON SPREADING INTO THE EAST HALF THU NIGHT AHEAD OF APPROACHING FRONTAL BOUNDARY. MOST OF THE MODELS SHOW SHRA/TSRA HANGING AROUND ON FRIDAY WITH ECMWF SHOWING FRONTAL PASSAGE TAKING PLACE AND GFS/CANADIAN SHOWING FRONTAL BOUNDARY APPROACHING THE WRN CWA. FRI NIGHT-SATURDAY...MODEL DIFFERENCES WILL HAVE BIGGEST IMPACT ON FCST TOWARD NEXT WEEKEND. IF 00Z ECMWF VERIFIES THEN FRI NIGHT AND SAT WILL BE MOSTLY DRY AND COOLER IN WAKE OF FRONTAL PASSAGE. THE 12Z SLOWER GFS AND CANADIAN SOLN WITH FRONT WOULD WARRANT KEEPING SHRA/TSRA CHCS IN FOR AT LEAST THE CENTRAL AND ERN FCST AREA FRI NIGHT AND MAYBE EVEN LINGERING INTO SAT MORNING. GFS AND CANADIAN WOULD THEN ARGUE FOR DRIER/COOLER CONDITIONS SAT AFTERNOON INTO SAT NIGHT AS HIGH PRES BUILDS IN FM THE NW IN THE WAKE OF THE FRONTAL PASSAGE. GIVEN POOR MODEL AGREEMENT WILL PROBABLY EMPLOY A BLEND OF FCST GUIDANCE FOR POPS DURING THIS PERIOD. NEXT SUNDAY...AGAIN MODEL DIFFERENCES WILL PROBABLY ARGUE FOR USING A BLEND OF MODEL GUIDANCE BY DAY 7 FCST. THIS WOULD WARRANT A DRY FCST FOR MUCH OF THE CWA ESPECIALLY CENTRAL AND EAST STILL UNDER INFLUENCE OF CANADIAN HIGH PRES OVER AREA. THE ECMWF SHOWS SYSTEM DEVELOPING OVER CENTRAL PLAINS AND TRIES TO DEVELOP PCPN ALONG THE WI BORDER COUNTIES IN STRENGTHENING WAA PATTERN OUT AHEAD OF IT. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 151 PM EDT SUN MAY 3 2015 EXPECT MAINLY VFR CEILINGS/VIS THROUGH THE PERIOD. THE ONLY EXCEPTION WILL BE IF AND WHEN TS ENTER THE AREA. SHOWERS AND ISOLATED TS ACTIVITY ACROSS CENTRAL MN WILL CONTINUE TO EDGE NE...WITH ADDITIONAL SHOWERS AND TS DEVELOPMENT ALONG THE NEARING COLD FRONT STRETCHING FROM SE ACROSS CENTRAL MANITOBA TO NEAR THE W LAKE SUPERIOR SHORELINE...AND THROUGH CENTRAL MN. LOOK FOR THE BEST CHANCE FOR TS DEVELOPMENT AT IWD 20-22Z. WHILE SAW WILL HAVE A CHANCE OF TS AROUND 23Z...IT WAS LESS LIKELY...SO LEFT VCTS OUT OF THE TAF FOR THEM. DRY HIGH PRESSURE ROLLING INTO E MT AND THE DAKOTAS THIS AFTERNOON WILL QUICKLY BUILD IN BEHIND THE FRONT. THE RESULT WILL BE A CLEAR/MOSTLY CLEAR BY DAYBREAK MONDAY IF NOT EARLIER. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 505 AM EDT SUN MAY 3 2015 OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD. LOW PRESSURE OVER NW ONTARIO WILL LIFT NORTHEAST TO HUDSON BAY...DRAGGING A COLD FRONT ACROSS LAKE SUPERIOR LATE THIS AFTERNOON AND EVENING ALONG WITH A CHANCE OF THUNDERSTORMS...AND PATCHY TO AREAS OF FOG. LOOK FOR HIGH PRESSURE ACROSS NORTH DAKOTA TONIGHT TO BUILD ACROSS THE UPPER GREAT LAKES MONDAY...WITH DRIER AIR LIMITING ANY LINGERING FOG ACROSS LAKE SUPERIOR. THE HIGH WILL SLOWLY EXIT ACROSS THE LOWER GREAT LAKES WEDNESDAY NIGHT...IN RESPONSE TO A LOW NEARING FROM THE N AND CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY. THE CHANCE OF THUNDERSTORMS WILL ALSO RETURN WEDNESDAY AFTERNOON THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...VOSS AVIATION...KF MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
152 PM EDT SUN MAY 3 2015 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 505 AM EDT SUN MAY 3 2015 WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD SHALLOW MID/UPPER LEVEL TROUGH OVER WRN CANADA...FROM BC INTO NW ONTARIO. A SHORTWAVE TROUGH AND ASSOCIATED SFC LOW WAS LIFTING NE FROM FAR NW ONTARIO TO TOWARD HUDSON BAY WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING INTO SRN MANITOBA. AT THE SFC...SSW FLOW WAS INCREASING THROUGH THE UPPER MS VALLEY INTO THE WRN LAKES AHEAD OF A COLD FRONT STRETCHING FROM NW MN INTO ERN SD. SCT SHRA AND ISOLD TSRA HAD DEVELOPED AHEAD OF THE FRONT OVER CNTRL INTO NE MN WITH FAVORABLE 925 MB THETA-E ADVECTION. UPSTREAM DEWPOINTS FROM MN INTO NW WI HAD CLIMBED TO AROUND 50. A SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL SLIDE THROUGH THE NRN GREAT LAKES LATE THIS AFTERNOON AND TONIGHT. MOISTURE IS EXPECTED TO INCREASE AHEAD OF THE FRONT WITH 850 MB DEWPOINTS NEAR 10C...SFC DEWPOINTS INTO THE LOWER 50S AND PWAT VALUES TO AROUND 1.25 INCH. EVEN WITH INCREASING CLOUDS...WAA WILL HELP PUSH TEMPS INTO THE MID TO UPPER 70S OVER THE WEST HALF. THE COMBINATION OF WEAK TO MODERATE 700-500 MB QVECTOR CONV AHEAD OF THE SHRTWV AND LOW LEVEL CONV ALONG AND AHEAD OF THE FRONT WILL SUPPORT SCT/NUMEROUS SHRA/TSRA INTO THE WEST HALF OF UPPER MI BY MID TO LATE SUN AFTERNOON AND ACROSS THE REST OF THE CWA SUN EVENING. LAKE BREEZE BOUNDARIES WILL ALSO PROVIDE A FOCUS FOR TSRA DEVELOPMENT. MLCAPE LIKELY TO AROUND 1K J/KG DURING PEAK AFTERNOON HEATING ALONG WITH 0-6KM SHEAR OF 30-35KT AND WBZERO HEIGHTS OF 9K- 10K FT MAY BE ENOUGH TO SUPPORT SOME ISOLD SEVERE STORMS WITH DAMAGING WINDS AND LARGE HAIL...MAINLY OVER THE SW CWA WHERE THE INSTABILITY IS EXPECTED TO GREATEST. THERE IS STILL SOME UNCERTAINTY WITH THE SEVERE RISK INTO UPPER MICHIGAN AS NAM REMAINS MORE AGGRESSIVE WITH THE AMOUNT OF MLCAPE AVAILABLE COMPARED TO THE ECMWF/GFS/GEM WHICH KEEP THE GREATER MOISTURE/INSTABILITY FARTHER SOUTH. EXPECT MOST OF THE SHRA/TSRA TO MOVE SOUTH AND EAST OF THE CWA BY 06Z WITH SOME LINGERING PCPN OVER THE FAR S AND E LATE. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 AM EDT SUN MAY 3 2015 ABOVE AVERAGE TEMPS WITH GENERALLY DRY CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA THROUGH TUESDAY BEFORE OFF AND ON CHANCES OF SHOWERS AND THUNDERSTORMS CLOSE OUT THE WEEK. MONDAY AND TUESDAY...A SPLIT UPPER JET PATTERN WILL BE WELL IN PLACE TO BEGIN THE PERIOD...WITH A VERY BROAD MID-LEVEL TROUGH ACROSS THE UPPER MS VALLEY AND UPPER GREAT LAKES. THE COLD FRONT AND ASSOCIATED CONVECTION EXPECTED TO INFLUENCE THE CWA THIS AFTERNOON AND TONIGHT WILL CLEAR THE CWA BY 12Z MONDAY. WITH SFC HIGH PRESSURE SHIFTING ACROSS THE CWA AND A MID-LEVEL RIDGE BUILDING ACROSS THE NORTHERN PLAINS...DRY CONDITIONS ARE EXPECTED MONDAY THROUGH TUESDAY. TEMPS WILL BE COOLER THAN TODAY FOR BOTH MONDAY AND TUESDAY AS 850 HPA TEMPS FALL TO 3-7C. WITH A WNW WIND MON...TEMPS WILL BE CHILLY ACROSS PORTIONS OF THE LAKE SUPERIOR SHORELINE...ESPECIALLY EAST OF MARQUETTE. SOME HINTS AS LINGERING LOW-LEVEL MOISTURE OVER EASTERN LAKE SUPERIOR MAY ALSO RESULT IN SOME FOG ALONG THE SHORELINE THROUGH MOST OF MONDAY. TUESDAY NIGHT AND WEDNESDAY...A BROAD SFC LOW FORMING UNDER THE SOUTHERN UPPER JET AND A MID-LEVEL TROUGH OVER THE SW STATES WILL BEGIN TO LIFT INTO THE CENTRAL PLAINS BY THIS TIME. MEANWHILE...THE MID-LEVEL RIDGE ACROSS THE PLAINS AND MS VALLEY WILL CONTINUE TO BUILD WHILE DRIFTING EASTWARD. LOW-LEVEL WAA/ISENTROPIC LIFT WELL AHEAD OF THIS LOW IS EXPECTED ACROSS WI AND THE WEST AND CENTRAL CWA TUESDAY NIGHT INTO WEDNESDAY...AND SHOULD BE ENOUGH TO GENERATE LIGHT RAIN ALOFT. HOW MUCH REACHES THE GROUND REMAINS IN QUESTION AS THE LOW-LEVELS WILL BE QUITE DRY TUESDAY. BECAUSE OF THIS...ALL MODEL SOLUTIONS SHOW A RAPID DETERIORATION OF THE PRECIP AS IT MOVES OVER UPPER MI. HAVE OPTED TO KEEP ONLY LOW CHANCE POPS ALONG THE WI BORDER TUESDAY NIGHT...AND ACROSS MUCH OF WESTERN AND CENTRAL UPPER MI ON WEDNESDAY. THURSDAY THROUGH SATURDAY...THE SFC LOW OVER THE PLAINS WILL CONTINUE TO MEANDER TO THE NE AS THE ASSOCIATED MID-LEVEL WAVE ATTEMPTS TO ROUND THE RIDGE. WITH MINIMAL FORCING...MUCH OF THE AREA SHOULD REMAIN DRY WED NIGHT INTO THU MORNING. BY THE AFTERNOON...FORCING FROM THE APPROACHING MID-LEVEL SHORTWAVE WILL BE ENOUGH TO INDUCE SCATTERED SHOWERS AND POSSIBLY SOME THUNDERSTORMS ACROSS THE WEST HALF OF THE CWA. WITH THE WAVE AND SFC LOW LIFTING ACROSS THE ARROWHEAD OF MN AND NORTH OF LAKE SUPERIOR...SCATTERED SHOWERS AND STORMS ARE EXPECTED INTO FRIDAY MORNING. COVERAGE MAY INCREASE FRIDAY AFTERNOON AS THE SFC COLD FRONT BEGINS TO MOVE IN FROM THE WEST. OVERALL...DO NOT SEE ANY REASON TO GO WITH ANYTHING HIGHER THAN HIGH-END CHANCE POPS GIVEN THE OVERALL SCATTERED NATURE OF EXPECTED PRECIP. BY SATURDAY...THE SFC COLD FRONT WILL CLEAR THE AREA AS IT BEGINS TO STALL/WASH OUT OVER WI. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 151 PM EDT SUN MAY 3 2015 EXPECT MAINLY VFR CEILINGS/VIS THROUGH THE PERIOD. THE ONLY EXCEPTION WILL BE IF AND WHEN TS ENTER THE AREA. SHOWERS AND ISOLATED TS ACTIVITY ACROSS CENTRAL MN WILL CONTINUE TO EDGE NE...WITH ADDITIONAL SHOWERS AND TS DEVELOPMENT ALONG THE NEARING COLD FRONT STRETCHING FROM SE ACROSS CENTRAL MANITOBA TO NEAR THE W LAKE SUPERIOR SHORELINE...AND THROUGH CENTRAL MN. LOOK FOR THE BEST CHANCE FOR TS DEVELOPMENT AT IWD 20-22Z. WHILE SAW WILL HAVE A CHANCE OF TS AROUND 23Z...IT WAS LESS LIKELY...SO LEFT VCTS OUT OF THE TAF FOR THEM. DRY HIGH PRESSURE ROLLING INTO E MT AND THE DAKOTAS THIS AFTERNOON WILL QUICKLY BUILD IN BEHIND THE FRONT. THE RESULT WILL BE A CLEAR/MOSTLY CLEAR BY DAYBREAK MONDAY IF NOT EARLIER. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 505 AM EDT SUN MAY 3 2015 OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WINDS ACROSS LAKE SUPERIOR SHOULD BE AROUND 25KTS OR LESS THROUGH THE PERIOD. LOW PRESSURE OVER NW ONTARIO WILL LIFT NORTHEAST TO HUDSON BAY...DRAGGING A COLD FRONT ACROSS LAKE SUPERIOR LATE THIS AFTERNOON AND EVENING ALONG WITH A CHANCE OF THUNDERSTORMS...AND PATCHY TO AREAS OF FOG. LOOK FOR HIGH PRESSURE ACROSS NORTH DAKOTA TONIGHT TO BUILD ACROSS THE UPPER GREAT LAKES MONDAY...WITH DRIER AIR LIMITING ANY LINGERING FOG ACROSS LAKE SUPERIOR. THE HIGH WILL SLOWLY EXIT ACROSS THE LOWER GREAT LAKES WEDNESDAY NIGHT...IN RESPONSE TO A LOW NEARING FROM THE N AND CENTRAL PLAINS WEDNESDAY NIGHT AND THURSDAY. THE CHANCE OF THUNDERSTORMS WILL ALSO RETURN WEDNESDAY AFTERNOON THROUGH FRIDAY. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...JLB LONG TERM...KLUBER AVIATION...KF MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
122 PM CDT Sun May 3 2015 .UPDATE: Issued at 104 PM CDT Sun May 3 2015 Nudged temps up a degree or two from the metro area east. Lowered Dps across s cntrl IL which match observed RH values already below 30%. The low RHs and fuel moisture below 10 percent will combine with breezy conditions to create elevated fire conditions this afternoon across s cntrl IL. Reduced going sky cover to clear/mostly. Also reduced PoPs this aftn across NE MO and w cntrl IL as it doesn`t appear that this threat will materialize. 2% && .SHORT TERM: (Today and Tonight) Issued at 325 AM CDT Sun May 3 2015 There is quite a bit of cloud cover early this morning across the region courtesy of two weak short waves in the westerly flow aloft. The first of these currently centered from northern IL into southeast MO has been generating some spotty high-based showers from the associated mid clouds/moisture. Present indications are this wave and the mid level moisture will continue to push east this morning with a few sprinkles still possible after 12z in south central IL. The other short wave is currently centered near the Nebraska/Iowa border into northeast KS and is more problematic. The associated convection has generated a sizable cloud canopy which has not been resolved by the models and will overspread a good portion of the CWA this morning. Unclear is how it will evolve with time - i.e. thinning, but the RAP has this wave centered through far eastern IA at midday and the current thought is to have quite a bit of clouds the first half of this morning then thinning and moving east by midday into early afternoon. There are also suggestions in the RAP, ECMWF, and a few of the hi-res WRFs that the southwest stretching tail of this short wave could generate a few showers across northeast MO and west central IL this afternoon and early this evening. I have added a slight chance as a result. Otherwise a warm day is on tap with well above normal temperatures expected. While the morning clouds will hamper the temp rise a bit, increasing south-southwesterly low level flow and rising low- level temperatures should compensate and will result in highs in the upper 70s to mid 80s across the area. South-southwest lower trop flow will maintain a low-level warm advection region tonight and moisture will gradually be improving. The thermal and moisture advection combined with a plume of relatively steep mid level lapse rates will result in a swath of weak instability across northern parts of the CWA in advance of the southward sinking cold front. While the front will remain well north of the CWA at daybreak Monday, northwest steering flow will help push at least scattered showers and thunderstorms or thunderstorm clusters into northeast MO and west central IL late tonight. We could also see spotty WAA generated showers well in advance of the activity that has moved off the front, hence the low pops all the way down to St. Louis. Glass .LONG TERM: (Monday through Saturday) Issued at 325 AM CDT Sun May 3 2015 The west-east oriented cold front will ooze southward out of IA and northern IL into northern sections of the CWA by early Monday evening. Ongoing showers and thunderstorms at daybreak should dissipate by midday. Heating and continued low-level moistening in their wake will result in weak-moderate instability along the frontal zone and the combo of a migrating impulse and good low level convergence along the boundary should result in extensive convective development during the later half of the afternoon spanning from KS across northern MO/southern IA into central IL. A broad veering southwesterly LLJ will maintain numerous thunderstorms/clusters during the evening, with the activity shunting a bit northward overnight in response to increasing ridging aloft and a slight northward shift in the frontal zone. The front will continue to shift northward on Tuesday as ridging aloft continues to build from the lower TN Valley into the upper MS Valley. There are some suggestions of air mass type convection across southern portions of the CWA but I`m not sold on it and have kept pops in the slight range and confined the coverage. Otherwise Tuesday will be another day of above normal temps with highs in the 80s. This warmth will persist on Wednesday and even into Thursday with the chance of showers and thunderstorms slowly increasing west-east over the 2 day period as the ridging aloft shunts east and southwest flow aloft becomes more dominant with time. The greatest threat of showers and thunderstorms in the extended period will be Friday-Saturday with an active southwest flow aloft, moist unstable warm sector, and slowly encroaching cold front. Glass && .AVIATION: (For the 18z TAFs through 18z Monday Afternoon) Issued at 104 PM CDT Sun May 3 2015 VFR fcst thru the prd. The region is on the backside of a large sfc ridge that is fcst to remain anchored just off the east coast. This will keep the area in return flow for an extended prd. Guidance indicates that a cold front will approach the region tonight but should stall along or near the IA/MO border. This will limit the best precip chances to those areas and have included a VCSH group at KUIN late tonight to account for the threat...though not confident that precip will make it that far south. Can`t completely rule out precip further south tonight into Monday mrng near I70 as these types of patterns often produce isld light precip further east and south than expected. Specifics for KSTL: Dry VFR fcst with sthrly flow...diurnal cu and aftn gusts. 2% && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1259 PM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 924 AM CDT SUN MAY 3 2015 JUST UPDATED TO ADD A 2-3 HOUR WINDOW OF OPPORTUNITY FOR ISOLATED RAIN SHOWERS/WEAK THUNDERSTORMS TO SEVERAL COUNTIES MAINLY EAST OF AN OSBORNE-CLAY CENTER-OSCEOLA LINE THIS MORNING. ALTHOUGH FORCING IS SUBTLE...THIS RECENT UPTICK IN ELEVATED ACTIVITY APPEARS TO BE TIED TO A SUBTLE MID LEVEL PASSING THROUGH AND GENERATING "JUST ENOUGH" LOW-MID LEVEL THETA-E ADVECTION TO KICK THINGS OFF. ALTHOUGH MODELS HAVE STRUGGLED TO PICK UP ON THIS...WOULD BE SURPRISED TO SEE ANY OF THIS EASTERN ACTIVITY LINGER PAST THE 11AM-12PM HOUR...AS STILL EXPECT THE MAJORITY OF THE CWA TO REMAIN DRY THE MAJORITY OF THE DAY. AS FOR THE LATE AFTERNOON/EVENING/OVERNIGHT STORM CHANCES...UNFORTUNATELY...UNCERTAINTY MAY BE HIGHER IN THE NOW THAN IT WAS 24 HOURS AGO REGARDING HOW THIS PLAYS OUT. PER SOME MODELS...THE OVERALL SEVERE THREAT MAY BE A BIT LESS THAN THOUGHT 24 HOURS AGO...BUT THAT BEING SAID...GIVEN WHAT HAPPENED YESTERDAY WITH THE GREATER-THAN-EXPECTED COVERAGE OF STRONG- SEVERE STORMS IN THE NORTHEAST CWA...THIS PATTERN IS PRONE TO YIELDING SURPRISES. STAY TUNED FOR PLENTY MORE THOUGHTS/UPDATED THINKING WITH THE AFTERNOON DISCUSSION. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 433 AM CDT SUN MAY 3 2015 BIGGEST CHALLENGE WILL BE DETERMINING CHANCES AND TIMING OF SHOWERS/THUNDERSTORMS AS WELL AS THE POTENTIAL FOR STRONG STORMS. ANOTHER CHALLENGE WILL BE DETERMINING HIGH TEMPERATURES FOR TODAY. SPLIT FLOW FOR TODAY...CAUGHT BETWEEN THE NORTH AND SOUTH STREAMS. LOCAL SYNOPTIC FLOW WILL BE ZONAL...BUT TURN MORE SOUTHWEST TONIGHT AS A NEGATIVELY TILTED BROAD UPPER LEVEL TROUGH ENTERS THE SOUTHWESTERN UNITED STATES. AT THE SURFACE...A COLD FRONT IS ON ITS WAY SOUTH ACROSS SOUTH DAKOTA. THE TIMING OF THIS FRONT SUGGESTS THAT WE WILL WARM UP SIGNIFICANTLY DUE TO COMPRESSIONAL WARMING. MODELS ARE GENERALLY NOT PICKING UP ON THIS WELL ENOUGH...SO I AM GOING OUT ON A BIT OF A LIMB AND GOING QUITE A BIT MORE THAN GENERAL GUIDANCE IN THE MID 80S. GOING FOR 91 FOR THE TRI-CITIES...FAVORING THE HI RES NMM SOLUTION. BELIEVE IT OR NOT...THIS WOULD BREAK OUR RECORD IN HASTINGS BY 2 DEGREES AND BE ONE DEGREE SHORT OF THE RECORD HIGH IN GRAND ISLAND. THE RAP MODEL BUMPS UP TEMPERATURES EVEN MORE IN NORTH CENTRAL KANSAS TO THE MID 90S. THESE WARMER TEMPERATURES WOULD HAVE PUT US IN THE REALM OF APPROACHING CRITICAL FIRE WEATHER ISSUES IF IT WERE NOT FOR THE FACT THAT WE HAVE GREENED UP. CHANCES OF PRECIPITATION ARE NOT CERTAIN. COVERAGE IS A BIT SPOTTY UNTIL THE CAP BREAKS IN THE EVENING. EVENT THEN...COVERAGE IS IN QUESTION...ESPECIALLY DEPENDING ON THE EXACT PLACEMENT OF THE FRONT WHEN STORMS FIRE. WE WILL PROBABLY NEED A HIGHER NARROW CORRIDOR OF CATEGORICAL CHANCES OF SHOWERS/THUNDERSTORMS...BUT AT THIS TIME...THAT IS VERY DIFFICULT TO DETERMINE...ESPECIALLY AS THE FRONT MAY TEMPORARILY STALL FOR A SHORT TIME TOWARD EVENING. A SECONDARY IMPULSE WITHIN MID-LEVEL FLOW COULD BOOST CHANCES OF RAIN OVERNIGHT...PROBABLY IN OUR SOUTH. I DO NOT GO OVER A 60 PERCENT CHANCE ANYWHERE IN THE CWA...AND HANG AROUND 40-50 PERCENT CHANCE FOR THE TRI-CITIES. AS FOR STRONG/SEVERE CHANCES...WE COULD GET SOME STRONG STORMS WITH MARGINAL INSTABILITY OF 500 TO 1500 J/KG AND LOW- LEVEL WIND SHEAR APPROACHING 30-35 IN OUR NORTH...BUT PROBABLY LOWER IN MOST OF THE REST OF THE CWA. THIS COULD BE ENOUGH TO GIVE US SOME STRONG STORMS WITH NICKEL SIZE HAIL AND PERHAPS A STRONG WIND GUST...BUT THE BETTER SUPPORT FOR SEVERE WEATHER LOOKS LIKE IT SHOULD BE EAST/NORTHEAST OF THE CWA. WENT WITH SIMILAR LOWS FOR TONIGHT COMPARED TO THE PREVIOUS FORECAST AND STUCK WITH SUPERBLEND IN THE 50S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 433 AM CDT SUN MAY 3 2015 PRIMARY FORECAST CONCERN CONTINUES TO REVOLVE AROUND THE MULTIPLE CHANCES FOR THUNDERSTORMS THROUGH THE ENTIRE PERIOD. THE UNSETTLED WEATHER PATTERN HAS SETTLED IN ACROSS THE REGION BY THE START OF THE PERIOD MON/MON NIGHT...WITH MODELS SHOWING THE AREA UNDER SOUTHWESTERLY FLOW ALOFT...WITH THE PARENT LOW PRESSURE OVER SRN CALIFORNIA AND WEAK RIDGING EXTENDING NORTH FROM THE GULF COAST INTO PORTIONS OF THE MIDWEST. MAY HAVE SOME LINGERING PRECIP ACROSS THE AREA DURING THE MORNING HOURS FROM OVERNIGHT ACTIVITY...BUT WOULD THINK THERE WOULD BE A LULL AT SOME POINT. HARD TO PINPOINT EXACTLY WHERE THAT LINGERING ACTIVITY MAY BE...SO HAVE CHANCE POPS ACROSS THE ENTIRE CWA. AT THE SFC...MODELS CONTINUE TO BE IN PRETTY GOOD AGREEMENT SHOWING THE PLACEMENT OF THE MAIN SFC FRONT OVER SRN PORTIONS OF THE CWA NEAR THE NEB/KS STATE LINE...WITH SOME SHOWING A LOW PLACED IN CLOSE PROXIMITY TO THE S/SWRN CORNER OF THE CWA. THE PLACEMENT OF THE SFC FRONT...UNCERTAINTY WITH THE AMOUNT OF SKY COVER /LIKELY HIGH/ AND ANY LINGERING PRECIP MAKES THE HIGH TEMP FORECAST TRICKY. MUCH OF SC NEB IS LOOKING AT ERLY WINDS NORTH OF THE FRONT...WITH MORE SRLY WINDS ACROSS NC KS. FORECAST HIGH TEMP IS A BLEND...AND COULD SEE CLOSE TO A 20 DEGREE GRADIENT ACROSS THE CWA /SOME MODELS ARE MORE DRASTIC/...WITH ARND 60 IN THE NORTH TO NEAR 80 IN THE FAR SOUTH. DURING THE AFTERNOON HOURS AND INTO THE EVENING/OVERNIGHT...THIS FRONTAL BOUNDARY WILL BE A FOCUS FOR ADDITIONAL THUNDERSTORM DEVELOPMENT AS YET ANOTHER DISTURBANCE MAKES ITS WAY INTO THE REGION...AIDED ALSO BY AN INCREASING LLJ. SEVERE WEATHER REMAINS A CONCERN WITH MODEST INSTABILITY AND SUFFICIENT DEEP LAYER SHEAR...LARGE HAIL/DAMAGING WINDS REMAIN THE PRIMARY CONCERNS...BUT WILL HAVE TO MONITOR THE POTENTIAL FOR AN ISOLATED TORNADO WITH THOSE MORE ERLY WINDS/INCREASED LOW LEVEL SHEAR IN THE AREA. SPC DAY 2 OUTLOOK SLIGHT RISK AREA INCLUDES ROUGHLY THE SERN HALF OF THE CWA. SIMILAR TO MONDAY...TUESDAY MORNING MAY HAVE SOME LINGERING ACTIVITY FROM OVERNIGHT...BUT MODELS SUGGEST THE OVERALL COVERAGE MAY NOT BE AS WIDESPREAD. THE MAIN UPPER LEVEL LOW HAS SHIFTED EAST INTO THE FOUR CORNERS REGION BY TUESDAY MORNING...AND MODELS CONTINUE TO SHOW THE POTENTIAL FOR THE LOW TO WEAKEN SOME/FILL...AS IT COMES UNDER INCREASING INFLUENCE OF A STRONGER UPPER LEVEL LOW MOVING INTO THE PAC NW REGION. AT THE SFC...DURING THE DAYTIME HOURS...THE FRONTAL BOUNDARY CONTINUING TO MEANDER AROUND CENTRAL PORTIONS OF THE CWA LOOKS TO PUSH NORTH AS A WARM FRONT...WITH MOST MODELS SHOWING SRLY WINDS IN PLACE ACROSS THE ENTIRE CWA DURING THE AFTERNOON. MODELS CONTINUE TO SHOW THE BETTER THUNDERSTORMS CHANCES ACROSS WRN PORTIONS OF THE CWA DURING THE AFTERNOON...SPREADING ACROSS THE REST OF THE CWA OVERNIGHT AS LIFT CONTINUES TO INCREASE WITH THE APPROACHING MAIN UPPER TROUGH/LOW...WHICH IS STARTING TO MAKE MORE OF A PUSH ONTO THE THE PLAINS DURING THE LATE TUES NIGHT HOURS/WED MORNING. WED/WED NIGHT CONTINUES TO BE THE PERIOD GENERALLY SHOWN BY MODELS WHEN THAT MAIN TROUGH AXIS /CLOSED LOW?/ MAKES ITS TREK NE THROUGH THE REGION...AS THAT STRONGER UPPER LEVEL LOW DIGS FURTHER SOUTH ALONG THE WEST COAST. THE HIGH CHANCE/LOW END LIKELY POPS CONTINUE IN THE FORECAST...SIMILAR TO PERIODS PRIOR AND FOLLOWING...HARD TO TRIM AREAS OUT OR RAISE POPS IN OTHERS WHEN SO MANY DETAILS HAVE YET TO BE IRONED OUT. THE LOCATION OF THE SFC LOW/ASSOCIATED BOUNDARIES LOOK TO BE PLAYING A BIGGER ROLE/FOCUS FOR CONVECTIVE DEVELOPMENT NEAR/ACROSS THE CWA...SO AS THEIR ULTIMATE PLACEMENT BECOMES MORE CLEAR IN THE COMING MODEL RUNS...CAN PIN DOWN BETTER DETAILS WITH POPS AND SEVERE WEATHER POTENTIAL. THROUGH THE REST OF THE LONG TERM PERIOD THURSDAY THROUGH SATURDAY...ONE NOTABLE DISTURBANCE MOVES OUT...BUT SOUTHWESTERLY FLOW REMAINS IN PLACE IN THE UPPER LEVEL AS THAT NEXT LOW PRESSURE SYSTEM CONTINUES TO DIG FURTHER SOUTH INTO CALIFORNIA. PIECES OF SHORTWAVE ENERGY ASSOCIATED WITH THAT LOW LOOK TO CONTINUE TO BRING AT LEAST PERIODIC THUNDERSTORM CHANCES...KEPT THE FORECAST CLOSE TO THE CR INIT/SUPERBLEND OUTPUT. && .AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1247 PM CDT SUN MAY 3 2015 ALTHOUGH CONFIDENCE IS REASONABLY HIGH IN WIND TRENDS...INCLUDING THE PASSAGE OF A FAIRLY NOTICEABLE COLD FRONT/DIRECTIONAL SHIFT LATE THIS AFTERNOON INTO THIS EVENING...CONFIDENCE IS BELOW AVERAGE REGARDING THE TIMING OF POTENTIAL MVFR CEILING DURING THE LATTER HALF OF THE PERIOD...AND WITH WHAT TIME FRAME(S) CARRIES THE HIGHEST POTENTIAL FOR SHOWER/THUNDERSTORM ACTIVITY. STARTING WITH THESE FIRST SEVERAL HOURS THIS AFTERNOON...DRY AND VFR CONDITIONS WILL PERSIST WITH A GENERALLY WESTERLY BREEZE LARGELY UNDER 12KT. STARTING AT 22Z AND LASTING THROUGH 06Z...HAVE INTRODUCED A GENERIC VICINITY THUNDERSTORM (VCTS) MENTION AS THIS SEEMS TO BE THE MAIN 8-HOUR WINDOW OF OPPORTUNITY FOR POSSIBLE STORMS NEAR THE TAF SITES (LATER UPDATES CAN "UPGRADE" TO TEMPO GROUPS AS NECESSARY). SHOULD ANY STORMS DIRECTLY AFFECT KGRI/KEAR...A PERIOD OF GUSTY WIND AND SMALL HAIL IS CERTAINLY POSSIBLE. AT LEAST FOR NOW...HAVE NOT MENTIONED ANY PRECIPITATION DURING THE 06Z-13Z TIME FRAME...BUT FROM 13Z ONWARD HAVE INTRODUCED AN MVFR CEILING ALONG WITH A GENERIC VICINITY SHOWERS (VCSH) MENTION. RE-VISITING SURFACE WIND TRENDS...ONCE THE COLD FRONT TRACKS THROUGH LATE THIS AFTERNOON/EVENING...A PREVAILING NORTH-NORTHEAST COMPONENT SETTLES IN WITH GUST POTENTIAL AT LEAST 15-20KT THROUGH THE REMAINDER OF THE PERIOD. && .CLIMATE... ISSUED AT 433 AM CDT SUN MAY 3 2015 PREDICTED HIGH TODAY: HASTINGS 91 GRAND ISLAND 91 RECORD HIGH: HASTINGS 89 (1959) GRAND ISLAND 92 (1959) && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...PFANNKUCH SHORT TERM...HEINLEIN LONG TERM...ADP AVIATION...PFANNKUCH CLIMATE...HEINLEIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1217 PM CDT SUN MAY 3 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 320 AM CDT SUN MAY 3 2015 TODAY...STORMS SHOULD CONTINUE EASTWARD OUT OF THE FORECAST AREA EARLY THIS MORNING. HIGH RES MODELS ARE IN GOOD AGREEMENT WITH THAT. STORMS LAST EVENING DID PRODUCE SOME LARGE HAIL AND A FEW SPOTS RECEIVED STRONG WINDS AS STORMS MIXED DOWN A STRONG LOW LEVEL JET. AS OF AROUND 07Z RUC MODEL INITIALIZATION SHOWED WINDS AT AROUND 1 KM AGL OF AROUND 40-50 KNOTS STRETCHING FROM WESTERN OKLAHOMA INTO SOUTHEAST NEBRASKA AND PARTS OF IOWA. THESE WINDS WILL DECREASE THIS MORNING. COLD FRONT AS OF 08Z STRETCHED FROM NORTHEAST MINNESOTA BACK INTO WESTERN SOUTH DAKOTA. THAT FRONT WILL MOVE SOUTHEAST INTO NORTHEAST NEBRASKA THIS AFTERNOON. LOOK FOR HIGHS IN THE MID TO UPPER 80S AT MOST SPOTS TODAY WITH A FEW HIGHS AROUND 90 POSSIBLE. THIS WILL CREATE CAPE VALUES FROM 1500 TO 2500 J/KG BY MID AFTERNOON. EXPECT CAP TO BREAK NEAR THE FRONT BY MID/LATE AFTERNOON. SOME MODELS ALSO HINT AT THE CAP WEAKENING FARTHER SOUTH...BUT WITH A LACK OF FOCUS AT THAT TIME WILL KEEP HIGHEST POPS CLOSER TO THE FRONT. SOME SEVERE STORMS APPEAR POSSIBLE...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN THREATS. GENERALLY USED A BLEND OF SHORT RANGE GUIDANCE FOR TONIGHT WITH THE HIGHEST WEIGHT GIVEN TO THE 00Z HIGH RES WRF-ARW MODEL. LIKE SOME OF THE OTHER MODELS...IT DEVELOPED STORMS LATE AFTERNOON THEN MOVED THEM SOUTH AND EAST. SOME STORMS MAY CONTINUE TO BE SEVERE IN THE EVENING. COVERAGE SHOULD DECREASE AFTER MIDNIGHT. CONVECTION WILL LIKELY FORCE THE FRONT DOWN AT LEAST AS FAR AS SOUTHEAST NEBRASKA AND MAYBE INTO NORTHEAST KANSAS BY 12Z MONDAY. MOST MODELS SHOW LIFT OCCURRING OVER THE BOUNDARY DURING THE DAY MONDAY WITH PCPN COVERAGE INCREASING...SO HAVE POPS INCREASING TO MATCH THAT. TWO CLUSTERS OF STORMS MAY TAKE SHAPE BY LATE AFTERNOON OR EARLY EVENING. ONE NEAR THE NEBRASKA/SOUTH DAKOTA BORDER AND ANOTHER LIFTING FROM NORTHERN KANSAS THROUGH OUR AREA AND TOWARD CENTRAL IOWA MONDAY NIGHT. TUESDAY...WE MAY SEE SOMEWHAT OF A BREAK IN THE WIDESPREAD PCPN... AT LEAST OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. HAVE POPS RANGING FROM 15 TO 50 PERCENT...HIGHEST IN NORTHEAST NEBRASKA. SOUTHERLY FLOW WILL INCREASE AND HELP A WARM FRONT LIFT NORTH OF THE AREA. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 320 AM CDT SUN MAY 3 2015 PATTERN WILL BE ACTIVE MUCH OF THIS PERIOD. A LARGE MID TROPOSPHERIC TROUGH SHOULD BE OVER THE WESTERN UNITED STATES AT THE START OF THIS PERIOD WITH EMBEDDED SHORTWAVES. ONE OF THESE WAVES WILL LIFT ACROSS MID AMERICA WEDNESDAY/WEDNESDAY NIGHT...WHILE A CLOSED LOW STARTS TO DIG SOUTHWARD FROM THE PACIFIC NORTHWEST. THIS WILL GENERALLY KEEP OUR AREA IN SOUTHWEST FLOW WITH A DECENT SUPPLY OF LOW LEVEL MOISTURE FOR SHOWERS AND STORMS TO WORK WITH. MODEL AGREEMENT STARTS TO FALL OFF BY DAY 7...SO CONFIDENCE FALLS TO AVERAGE BY DAY 7. TEMPERATURES AND PCPN SHOULD BE AT OR ABOVE NORMAL FOR THIS PERIOD. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1211 PM CDT SUN MAY 3 2015 SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE IN AREAL COVERAGE THIS AFTN ALONG A COLD FRONT PUSHING THRU ERN NEB. IT IS POSSIBLE THAT A FEW STORMS MAY APPROACH OR BECOME SEVERE LATE THIS AFTN. HAVE ADDED TEMPO GROUPS AT ALL TERMINALS FOR POSSIBLE LATE AFTN/EARLY EVENING MVFR CONDITIONS. VFR CONDITIONS THEN PREVAILING THIS EVENING THRU THE REST OF THE FCST PD. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...PEARSON/MILLER LONG TERM...MILLER AVIATION...DEE
AREA FORECAST DISCUSSION
NWS ELKO NV
319 PM PDT SUN MAY 3 2015 .SYNOPSIS...WARMER THAN NORMAL CONDITIONS WILL CONTINUE THROUGH TUESDAY...THEN MUCH COOLER FOR THE MIDDLE AND END OF NEXT WEEK COURTESY OF A COOL LOW PRESSURE SYSTEM. THUNDERSTORMS POSSIBLE EACH AFTERNOON...SOME OF THE STORMS WILL PRODUCE STRONG GUSTY WINDS BUT VERY LITTLE IN THE WAY OF RAINFALL. HOWEVER BEGINNING THURSDAY MUCH OF THE AREA WILL HAVE A GOOD SHOT OF WELCOME PRECIPITATION. && .SHORT TERM...TODAY THROUGH WEDNESDAY. RESIDUAL MOISTURE FROM YESTERDAY RESULTING IN MORE INSTABILITY THAN PREVIOUSLY INDICATED. BEST INSTABILITY IS LOCATED IN NORTHERN LANDER/EUREKA AND ELKO COUNTIES. SHEAR IS MINIMAL...WITH MOST AREAS 15 TO 25KTS. THAT IS GOOD ENOUGH FOR SOME MULTICELLUAR STORMS WITH SMALL HAIL AND GUSTY WINDS TO 55 MPH. WOULD NOT BE SHOCKED TO SEE SOME SLIGHTLY HIGHER GUSTS NEAR OR ABOVE 55 MPH...DUE TO FAVORABLE INVERTED V SOUNDINGS AND DRY SUB CLOUD LAYER. JUST EAST INTO UTAH...ALREADY HAD A GUST TO 57 MPH. THE LATEST HRRR MODEL RUNS SHOWS THIS ACTIVITY SHIFTING NORTHWARD/NORTHEASTWARD THROUGH THE EVENING. LIGHTNING WILL DIMINISH AFTER SUNSET...BUT SHOWERS WILL CONTINUE THROUGH THE EVENING. EXPECT MORE OF THE SAME MONDAY AND TUESDAY AS INSTABILITY AND MOISTURE REMAIN. COULD BE A SLIGHT UPTICK IN CONVECTION TOMORROW WITH ADDITIONAL STRONG STORMS POSSIBLE. TUESDAY...CONVECTION WILL FOCUS IN CENTRAL AND EASTERN NEVADA. ON WEDNESDAY...UPPER LEVEL TROUGH STARTS TO DIG INTO NORTHERN NEVADA WITH A COLD FRONT SLOWING/STALLING ACROSS EASTERN NEVADA. WITH INSTABILITY AND FRONTAL DYNAMICS...COULD SEE SOME MODERATE TO HEAVY SHOWERS/STORMS FORM ALONG/BEHIND THAT FRONT IN EASTERN NEVADA. .LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY. A STRONG UPPER LEVEL TROUGH ACCOMPANIED BY AN UPPER LEVEL JET /H3 100 KT/ WILL DIG SOUTHWARD FROM THE PACIFIC NORTHWEST TO NORTHERN CALIFORNIA WEDNESDAY NIGHT. HAVE INCREASED POPS FOR A SMOOTH TRANSITION FROM THE END OF THE SHORT TERM PERIOD INTO WEDNESDAY NIGHT. THURSDAY...MODELS BRING THE UPPER LEVEL SYSTEM TO NORTH CENTRAL CALIFORNIA DURING THURSDAY. BOTH THE GFS/ECMWF ARE NOW IN FAIRLY GOOD POSITIONAL AGREEMENT. HAVE TRENDED THE POPS UP AS THE ASSOCIATED SURFACE COLD FRONT TRANSITIONS ACROSS NORTHERN AND CENTRAL NEVADA DURING THE DAY. SURFACE WINDS WILL BE BREEZY IN ADVANCE AND ALONG THE SURFACE COLD FRONT ESPECIALLY OVER WHITE PINE AND NORTHEAST NYE COUNTIES. NOT MUCH CHANGE WAS NOTED WITH THE SNOW LEVELS AS THEY WILL REMAIN AROUND 6500-7500 FEET. WITH IS SYSTEM INFLUENCING THE CWA...THE CLOUD COVER...PRECIPITATION AND COLD AIR WILL RESULT IN BELOW NORMAL THURSDAY. THURSDAY NIGHT THROUGH SATURDAY...THE GFS AND ECMWF ARE IN GOOD AGREEMENT MOVING THE UPPER LOW ACROSS SOUTHERN NEVADA AND INTO CENTRAL UTAH THROUGH SATURDAY. WITH THE COLD CORE OF THIS TROUGH MOVING THROUGH THE GREAT BASIN...SCATTERED RAIN AND SNOW SHOWERS WILL BE COMMON ALONG WITH THE POTENTIAL FOR AFTERNOON AND EVENING THUNDER FRIDAY AND SATURDAY AFTERNOON. AFTERNOON MAX TEMPERATURES WILL REMAIN AOB NORMAL LEVELS DURING THIS PERIOD. SUNDAY...AS THE TROUGH SHIFTS INTO THE INTER-MOUNTAIN WEST...A SHORT WAVE RIDGE BUILDS INTO THE GREAT BASIN SUNDAY. MID/HIGH LEVEL CLOUDS WILL BE EVIDENT SPILLING OVER THE RIDGE WHICH WILL HOLD AFTERNOON TEMPERATURES DOWN TO NEAR NORMAL LEVELS. && .AVIATION...CONVECTION HAS FIRED UP BASICALLY ON A FROM LANDER/EUREKA COUNTIES NORTHEASTWARD INTO SOUTHERN AND NORTHEASTERN ELKO COUNTIES. SOME OF THE STRONGER CELLS AND ASSOCIATED OUTFLOWS HAVE PRODUCED SURFACE WIND GUSTS FROM 35 TO 45 MPH. EXPECT THIS TO CONTINUE INTO THIS EVENING BEFORE TRANSITIONING INTO SHOWERS LATER TONIGHT. SIMILAR CONDITIONS ARE EXPECTED AGAIN ON MONDAY. EXPECT VFR CONDITIONS WITH THE POSSIBILITY OF MVFR CONDITIONS NEAR THE CORES OF THE STRONGEST STORMS. .EQUIPMENT...THE WINNEMUCCA ASOS IS EXPERIENCING TELECOMMUNICATIONS ISSUES AT THIS TIME. ALTHOUGH THE ASOS IS NOT TRANSMITTING OBSERVATIONS THROUGH THE INTERNET...LANDLINE COMMUNICATIONS REMAIN OPERATIONAL. IT IS NOT KNOWN AT THIS TIME WHEN THIS WILL BE REPAIRED. && .LKN WATCHES/WARNINGS/ADVISORIES...NONE. && $$ 94/89/89
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1251 PM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 1234 PM CDT SUN MAY 3 2015 FORECAST ON TRACK. NO CHANGES NEEDED. UPDATE ISSUED AT 953 AM CDT SUN MAY 3 2015 BASED ON CURRENT RADAR TRENDS AND HIGH RESOLUTION MODEL SOLUTIONS MAINTAINED ISOLD T THROUGH THE REMAINDER OF THE MORNING ACROSS THE FAR SE CORNER OF THE FA. ALSO MENTIONED SOME SPRINKLES VCNTY VALLEY CITY IN ZONE OF WEAKENING FRONTOGENETIC FORCING. ALSO INCREASED CLOUD COVER THIS MORNING ACROSS ALL BUT THE FAR NORTH AND SOUTH. UPDATE ISSUED AT 648 AM CDT SUN MAY 3 2015 SOME DECENT RADAR RETURNS HAVE DEVELOPED OVER CENTRAL ND ALONG THE 700MB FRONTOGENESIS BAND...WITH A LITTLE BIT OF LIGHT RAIN REACHING THE GROUND AT BIS. THE FRONTOGENESIS WILL BEGIN TO MOVE INTO OUR SOUTHERN COUNTIES BY 15Z...BUT THE RAP AND HRRR HAVE LITTLE TO NO QPF. WILL CONTINUE TO KEEP SOME MINIMAL POPS IN THE SOUTH AND EAST THIS MORNING BUT THINK THAT IT SHOULD BE FAIRLY QUIET. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 346 AM CDT SUN MAY 3 2015 WINDS TODAY AND TEMPERATURES THROUGHOUT THE PERIOD WILL BE THE MAIN FORECAST ISSUES FOR THE SHORT TERM. A SHORTWAVE TROUGH MOVING ACROSS SOUTHERN MANITOBA TODAY AND INTO ONTARIO WILL HELP PUSH A WEAK COLD FRONT THROUGH THE CWA. WINDS HAVE ALREADY SHIFTED TO THE NORTH ACROSS THE DEVILS LAKE BASIN AND NORTHERN RED RIVER VALLEY. THINK THAT THE BOUNDARY WILL BE THROUGH THE SOUTHERN AND EASTERN CWA BY THE 15 TO 18Z TIME FRAME. A FEW LINGERING SHOWERS MAINLY OVER THE SOUTHEASTERN COUNTIES WILL BE POSSIBLE...BUT ANY AMOUNTS WILL BE EVEN LIGHTER THAN YESTERDAY. WINDS WILL BE THE MAIN CONCERN THIS AFTERNOON. THERE WILL BE A FAIRLY DECENT PRESSURE GRADIENT WHICH SHOULD MAKE IT SOMEWHAT BREEZY. MIXING UP TO AROUND 800MB OR SO IS LIKELY...BUT WINDS AT THE TOP OF THE MIXED LAYER ARE ONLY AROUND 20 KTS. THINK THAT SOME SUSTAINED WINDS IN THE TEENS WITH GUSTS ABOVE 20 MPH WILL BE POSSIBLE...ENOUGH TO CAUSE SOME FIRE WEATHER HEADACHES. TEMPS SHOULD BE COOLER THAN YESTERDAY BUT STILL PRETTY MILD...RISING INTO THE 60S TO LOW 70S. TONIGHT...SFC HIGH PRESSURE WILL BUILD INTO THE REGION...BRINGING MOSTLY CLEAR SKIES AND LIGHT WINDS. THIS SHOULD ALLOW TEMPS TO FALL INTO THE UPPER 30S TO LOW 40S. MONDAY WILL ALSO BE VERY QUIET UNDER NEAR ZONAL FLOW AS THE SFC HIGH BEGINS TO MOVE EAST. WINDS SHOULD BE SHIFTING TO THE SOUTH BUT WILL REMAIN FAIRLY LIGHT AND THINK THAT HIGHS AGAIN WILL BE IN THE 60S TO LOW 70S. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 346 AM CDT SUN MAY 3 2015 MONDAY NIGHT THROUGH TUESDAY NIGHT...THE MAIN EVENT WILL BE AN UPPER TROUGH MOVING FROM THE DESERT SOUTHWEST THROUGH COLORADO AND OUT INTO THE CENTRAL PLAINS. SFC LOW PRESSURE WILL BEGIN TO DEVELOP TO OUR WEST AND BRING SOME HIGHER MOISTURE LEVELS AS SOUTHERLY WINDS KICK IN. TEMPS SHOULD BE RISING AGAIN WITH MORE HIGHS IN THE 70S FOR TUESDAY. SFC LOW PRESSURE WILL BE MOVING UP INTO WESTERN SD TUESDAY NIGHT...WITH A WARM FRONT PUSHING INTO ND MAINLY AFTER MIDNIGHT. CONTINUED WITH HIGH POPS FOR TUESDAY NIGHT...AND WITH SHOWALTERS NEAR ZERO KEPT MAINLY SHOWERS WITH ISOLATED THUNDER FOR NOW. WEDNESDAY THROUGH SATURDAY...THE LONG TERM MODELS CONTINUE TO LOOK WET FOR THE MIDDLE PART OF THE WORK WEEK...WITH THE GULF OPENING UP ON TUESDAY FOR DECENT MOISTURE FLUX INTO THE CENTRAL AND NORTHERN PLAINS. A SW UPPER FLOW PATTERN SETS UP ON TUESDAY AND PRECIPITATION BEGINS TO LIFT OUT OF THE CENTRAL PLAINS TUE NIGHT INTO WEDNESDAY. A SFC LOW THEN MOVES INTO NE/SD WED INTO THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS CONTINUE TO HAVE SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY DRY SLOT WHICH MAY OCCUR AS THE LOW LIFTS INTO NW MN AND ONTARIO...HOWEVER THERE IS A STRONG SIGNAL FOR PRECIPITATION ACROSS THE CWA IN THE WED/THU TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO THE DRY FIRE WX CONDS WE HAVE HAD OVER THE LAST SEVERAL WEEKS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1245 PM CDT SUN MAY 3 2015 MODERATE NORTHWEST BOUNDARY LAYER WINDS ACROSS THE FA THIS AFTERNOON WILL DIMINISH WITH NIGHTFALL. MID TO UPPER LEVEL CLOUDS ALG AND EAST OF A ROX-RDR-JMS LINE WILL STEADILY SHIFT EASTWARD WITH VFR CONDS PERSISTING THROUGHOUT THE PERIOD. SURFACE HIGH PRESSURE SHOULD BE CENTERED OVER THE RRV EARLY MONDAY MORNING WITH LIGHT AND VARIABLE WINDS AND FAIR SKIES. && .FIRE WEATHER... ISSUED AT 337 AM PM CDT SAT MAY 2 2015 THE LONG TERM MODELS CONTINUE TO LOOK WET FOR THE MIDDLE PART OF THE WORK WEEK...WITH THE GULF OPENING UP ON TUESDAY FOR DECENT MOISTURE FLUX INTO THE CENTRAL AND NORTHERN PLAINS. A SW UPPER FLOW PATTERN SETS UP ON TUESDAY AND PRECIPITATION BEGINS TO LIFT OUT OF THE CENTRAL PLAINS TUE NIGHT INTO WEDNESDAY. A SFC LOW THEN MOVES INTO NE/SD WED INTO THU...KEEPING PRECIP ACROSS ND AND NW MN. MODELS CONTINUE TO HAVE SLIGHT DIFFERENCES IN PLACEMENT AND TIMING OF ANY DRY SLOT WHICH MAY OCCUR AS THE LOW LIFTS INTO NW MN AND ONTARIO...HOWEVER THERE IS A STRONG SIGNAL FOR PRECIPITATION ACROSS THE CWA IN THE WED/THU TIMEFRAME. THIS COULD PROVIDE SOME RELIEF TO THE DRY FIRE WX CONDS WE HAVE HAD OVER THE LAST SEVERAL WEEKS. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...VOELKER SHORT TERM...JR LONG TERM...JR/SPEICHER AVIATION...GUST FIRE WEATHER...SPEICHER
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
324 PM CDT SUN MAY 3 2015 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 323 PM CDT SUN MAY 3 2015 HAVE SEEN SCATTERED SPRINKLES/LIGHT SHOWERS DEVELOP OVER THE WESTERN CWA ALONG ELEVATED BOUNDARY AHEAD OF THE MID LEVEL WAVE. UPDATED GRIDS TO PROGRESS THIS ACTIVITY EASTWARD ACROSS THE AREA THIS AFTERNOON...WITH CONVECTIVE POTENTIAL GRADUALLY INCREASING ACROSS SOUTHEAST HALF OF THE FORECAST AREA AS THE ELEVATED FRONT WORKS INTO MORE UNSTABLE AIR MASS. SURFACE BASED STORMS MAY BE TOUGHER TO COME BY...AS SURFACE CONVERGENCE SOMEWHAT ILL-DEFINED WITH BROAD AREA OF WEAK/VARIABLE FLOW AHEAD OF THE BOUNDARY... LOCATED SOUTH OF KYKN-KFSD-KTKC LINE AT 18Z. ISOLATED SEVERE STILL APPEAR POSSIBLE ACROSS THE SOUTHEAST...WITH RECENT HRRR MODEL RUNS INDICATING A POTENTIAL FOR WIND THREAT ASSOCIATED WITH COLD POOL AHEAD OF ELEVATED STORMS AS THEY TRACK ACROSS EXTREME SOUTHEAST SD/NORTHWEST IA. NOT WHOLLY CONVINCED THIS WILL PAN OUT...BUT DOES NOT SEEM ENTIRELY UNREASONABLE GIVEN HIGHER-BASED STORMS WITH DRIER AIR UNDERCUTTING BEHIND SURFACE BOUNDARY...SO WILL DEFINITELY NEED TO MONITOR THROUGH THE LATE AFTERNOON/EARLY EVENING. OVERALL CONVECTIVE CHANCES SHOULD WANE AFTER 02Z-03Z AS THE WAVE PASSES BY...WITH OVERNIGHT HOURS INTO EARLY MONDAY MORNING EXPECTED TO BE DRY ACROSS THE AREA. INCREASING ISENTROPIC LIFT AHEAD OF BROAD WAVE SHOULD BEGIN TO SPREAD PRECIP BACK INTO SOUTHERN PARTS OF THE AREA MONDAY AFTERNOON...WITH MAIN QUESTION BEING HOW QUICKLY IT EXPANDS TO THE NORTHEAST THE DRY LOW LEVEL EAST-NORTHEAST FLOW FIRMLY IN PLACE. WILL HOLD GENERALLY SOUTHWEST OF KHON-KFSD-KSPW LINE...SUPPORTED BY GREATER MODEL CONSENSUS OF NAM/ECMWF/GEM. MONDAY SHOULD BE A COOLER DAY...WITH THICKER CLOUDS HOLDING TEMPS IN THE 60S THROUGH THE MISSOURI VALLEY...WITH LOWER 70S MORE PREVALENT TO THE NORTHEAST. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 323 PM CDT SUN MAY 3 2015 ON MONDAY NIGHT AND TUESDAY A WARM FRONT BEGINS TO LIFT NORTHWARD THROUGH NEBRASKA...WITH INCREASING MIDLEVEL THETA E ADVECTION ACROSS OUR AREA DURING THE PERIOD. WITH THIS WILL HAVE INCREASING PRECIPITATION CHANCES...ESPECIALLY IN OUR SOUTH AND EAST. INSTABILITY IS NOT ESPECIALLY IMPRESSIVE SO STAYED MAINLY WITH ISOLATED THUNDER...ALTHOUGH IT DOES LOOK TO BE A LITTLE MORE UNSTABLE IN OUR SOUTH ON TUESDAY AFTERNOON. HIGHS ON TUESDAY WILL MAINLY BE UPPER 60S TO LOWER 70S...THOUGH AREAS THROUGH THE LOWER MO RIVER VALLEY MAY APPROACH 80. ON WEDNESDAY A MORE SIGNIFICANT VORT LOBE BEGINS TO LIFT OUT OF THE WESTERN CONUS UPPER LEVEL TROUGH AND INTO THE CENTRAL AND NORTHERN PLAINS. THIS WILL MOSTLY LIKELY BRING MORE SIGNIFICANT PRECIPITATION TO THE AREA FOR LATER ON WEDNESDAY INTO WEDNESDAY NIGHT. WHILE IT WILL BE FAIRLY UNSTABLE ON WEDNESDAY...SHEAR IS RATHER UNIMPRESSIVE...BUT THERE WILL MOST LIKELY BE THUNDERSTORMS AROUND. HIGHS AGAIN WILL BE RUNNING LOWER TO MID 70S. RAIN CHANCES THEN CONTINUE INTO THURSDAY WHEN A SURFACE FRONTAL BOUNDARY SWINGS ACROSS THE AREA AS THE UPPER LEVEL SHORTWAVE PULLS OFF INTO THE WESTERN GREAT LAKES REGION. MAY FINALLY BEGIN TO DRY OUT BY THURSDAY NIGHT AND FRIDAY AS HIGH PRESSURE BEGINS TO BUILD BACK INTO THE REGION BEHIND THE EXITING SYSTEM. SLIGHTLY COOLER AIR FILTERS INTO THE AREA FOR FRIDAY...THOUGH STILL LOOKING AT HIGHS MID 60S TO LOWER 70S. RAIN DOES LOOK TO RETURN BY NEXT WEEKEND HOWEVER AS ANOTHER UPPER LEVEL LOW LIFTS OUT OF THE WESTERN CONUS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 147 PM CDT SUN MAY 3 2015 CONVECTIVE CHANCES THROUGH THE AFTERNOON/EARLY EVENING...ALONG WITH GUSTY POST-FRONTAL SURFACE WINDS...ARE PRIMARY CONCERNS FOR THIS TAF PERIOD. CONVECTIVE THREAT SOMEWHAT ILL-DEFINED AS COOL FRONT WORKS THROUGH MODERATELY UNSTABLE AIR MASS IN NORTHWEST IOWA THIS AFTERNOON. SCATTERED THUNDERSTORMS STILL APPEAR POSSIBLE IN AREAS SOUTH/EAST OF KFSD AND WILL MAINTAIN DRY FORECAST FOR KFSD AS THIS POINT...THOUGH POTENTIAL FOR ISOLATED ELEVATED SHRA/TSRA FOR AN HOUR OR TWO IN THE LATE AFTERNOON. GREATER CHANCE FOR THE KSUX AREA IN THE EARLY EVENING AS ELEVATED FRONT WORKS THROUGH THE AREA. LATE AFTERNOON/EVENING THUNDERSTORM ACTIVITY COULD PRODUCE VARIABLE GUSTY WINDS...POSSIBLY IN EXCESS OF 40KT...THOUGH LOWER CONFIDENCE IN TIMING/LOCATION OF WIND THREAT PRECLUDES MENTION IN TAFS AT THIS TIME. POST-FRONTAL WINDS GUSTING 20-30KT MORE WIDESPREAD AND EXPECTED TO PERSIST INTO THE EVENING BEFORE DIMINISHING AFTER DARK. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ SHORT TERM...JH LONG TERM...JM AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
147 PM CDT SUN MAY 3 2015 .UPDATE... ISSUED AT 147 PM CDT SUN MAY 3 2015 HAVE SEEN SCATTERED SPRINKLES/LIGHT SHOWERS DEVELOP OVER THE WESTERN CWA ALONG ELEVATED BOUNDARY AHEAD OF THE MID LEVEL WAVE. UPDATED GRIDS TO PROGRESS THIS ACTIVITY EASTWARD ACROSS THE AREA THIS AFTERNOON...WITH CONVECTIVE POTENTIAL GRADUALLY INCREASING ACROSS SOUTHEAST HALF OF THE FORECAST AREA AS THE ELEVATED FRONT WORKS INTO MORE UNSTABLE AIR MASS. SURFACE BASED STORMS MAY BE TOUGHER TO COME BY...AS SURFACE CONVERGENCE SOMEWHAT ILL-DEFINED WITH BROAD AREA OF WEAK/VARIABLE FLOW AHEAD OF THE BOUNDARY... LOCATED SOUTH OF KYKN-KFSD-KTKC LINE AT 18Z. ISOLATED SEVERE STILL APPEAR POSSIBLE ACROSS THE SOUTHEAST...WITH RECENT HRRR MODEL RUNS INDICATING A GREATER POTENTIAL FOR WIND THREAT ASSOCIATED WITH EXPANDING COLD POOL AHEAD OF ELEVATED STORMS AS THEY TRACK ACROSS EXTREME SOUTHEAST SD/NORTHWEST IA. OTHERWISE FORECAST APPEARS FAIRLY WELL ON TRACK. POST-FRONTAL WINDS BECAME STRONGER THAN ANTICIPATED WITH INITIAL DEEPER MIXING ACROSS NORTHWEST PARTS OF THE CWA IN THE LATE MORNING...BUT SEEM TO HAVE TAMED DOWN CLOSER TO EXPECTED RANGES NOW. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 358 AM CDT SUN MAY 3 2015 CONCERNS THIS TODAY AND TONIGHT DEAL WITH CONVECTION CHANCES THIS AFTERNOON ALONG WITH POST FRONTAL FIRE DANGER. EARLY THIS MORNING...LOW LVL JET CONTINUES TO VEER AND PUSH CONVECTION EASTWARD AND AWAY FROM THE CWA INTO CENTRAL IOWA. THERE REMAINS AN OUTSIDE CHANCE FOR A FEW SHOWERS TO POPUP OVER THE EASTERN ZONES...BUT LOOKING LESS LIKELY. THE MAIN STORY TODAY WILL BE FOCUSED ON A FRONTAL BOUNDARY DROPPING SOUTHEAST THROUGH THE AREA THIS EVENING. EARLY THIS MORNING...THE FRONT WAS DRAPED ACROSS CENTRAL SOUTH DAKOTA...ALLOWING LOW TO MID 50 DEW POINTS TO POOL AHEAD OF IT. THIS FRONT WILL SLOWLY PRESS SOUTHEAST STRETCHING FROM WORTHINGTON TO YANKTON BY 4PM. MODELS CONTINUE TO SHOW MODEST DESTABILIZATION THROUGH THE DAY...WITH UPWARDS OF 1500-2000 J/KG MLCAPE VALUES DEVELOPING ALONG AND BEHIND THE BOUNDARY BY LATE AFTERNOON. THERE WILL LIKELY BE TWO MAIN FORCING MECHANISMS THIS AFTERNOON...INCREASING FRONTAL CONVERGENCE LATE THIS AFTERNOON ACROSS THE NORTHEASTERN HALF OF THE FRONT IN MN...AND A SHORTWAVE ROTATING ACROSS NEBRASKA. WHILE DIFFICULT TO PICKUP IN WV IMAGERY...THIS SHORTWAVE WAS BEGINNING TO ENTER THE WESTERN PLAINS EARLY THIS MORNING...EVIDENT BY VEERING NPN/VWP. THE DIFFICULTY THUS FAR...IS ASSESSING THE STRENGTH OF THIS SHORTWAVE...WHICH MODELS HAVE BEEN STRUGGLING WITH. SOUNDINGS INDICATE A RELATIVELY CAPPED ENVIRONMENT...WHICH SHOULD HOLD OFF SFC BASED CONVECTION UNTIL MID-LATE AFTERNOON...WHEN CONVERGENCE ALONG THE BOUNDARY OVER CENTRAL MN SHOULD BE SUFFICIENT. LATEST GUIDANCE SUGGESTS THIS BOUNDARY MAY SURGE A BIT FASTER OVER NORTHERN AND CENTRAL MINNESOTA WITH RATHER HIGH PRESSURE RISES ACROSS THE WESTERN DAKOTAS. THIS IN RETURN COULD LIMIT THE CONVECTIVE POTENTIAL OVER OUR SW MN COUNTIES. HOWEVER...FURTHER SOUTHWEST ALONG THE LINE...INTO FAR SE SD...NW IA...AND NE...INITIAL ISOLATED CONVECTION MAY BE MORE POST FRONTAL AND ELEVATED IN NATURE...DEVELOPING ALONG A SECONDARY 925:850 CONVERGENCE ZONE. MORE ISOLATED TO PERHAPS SCATTERED SFC BASED CONVECTION COULD DEVELOP ONCE FORCING ALOFT CATCHES UP TO THE SFC FRONT TOWARD 00Z. AT THIS POINT...FORCING ASSOCIATED WITH THE SHORTWAVE MAY BE THE MORE DOMINATE FOCUS FOR CONVECTION AS OPPOSED TO THE FRONT...WITH THE BEST CHANCES FOR THUNDER ALONG A YANKTON TO SPENCER LINE. THAT SAID...WOULD NOT BE SURPRISED IF CONVECTION IS JUST NOT THAT WIDESPREAD. AGAIN...INSTABILITY IS MODERATE...BUT SHEAR PROFILE SEEMS MARGINAL FOR THE EVENT. BEST SHEAR IS ACTUALLY IN THE POST FRONTAL ENVIRONMENT. THAT SAID...WOULD ANTICIPATE FAIRLY ISOLATED TO AT MOST SCATTERED CONVECTION...WITH ISOLATED SVR STORMS. RELATIVELY STEEP LAPSE RATES...AND POCKET OF MID-LVL DRY AIR WOULD SUPPORT DAMAGING WIND THREAT. CAPE PROFILE FAIRLY ELONGATED...BUT SKINNY IN NATURE. WITH THE RELATIVELY LOW SHEAR ENVIRONMENT...LOOKING AT A MARGINAL HAIL THREAT. TORNADIC THREAT APPEARS LOW...GIVEN POOR 0-1KM SHEAR...AND RATHER HIGH LCLS. THE SHORTWAVE WILL MOVE QUICKLY EASTWARD IN THE EVENING...WITH CONVECTION PUSHING THE ELEVATED MOISTURE LAYER SOUTH OF THE CWA. DEPENDING ON THE CLEARING...LOOKING AT LOWS IN THE 40S. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 358 AM CDT SUN MAY 3 2015 WHILE STRONGER RIDGING WILL ATTEMPT TO BECOME REESTABLISHED ACROSS THE NORTHERN PLAINS ON MONDAY...WILL HAVE TO DEAL WITH LIFT ASSOCIATED WITH EXITING UPPER JET ENTRANCE REGION PULLING ACROSS THE AREA MONDAY INTO MONDAY EVENING. THE MORNING HOURS WILL SEE MAIN BOUNDARY AT LOWER LEVELS CONTINUING THE PUSH TO AREAS BETWEEN I-80 AND I-70...WITH FAIRLY STRONG PUSH OF LOWER LEVEL DRY AIR THROUGH MUCH OF THE CWA. MID LEVEL MOISTURE SHOULD STALL ACROSS THE AREA... BUT NO MORE THAN A MINIMAL THREAT OF A MID BASED SHOWER ALONG THE EXTREME SOUTHERN BORDER THROUGH THE MORNING. INSTABILITY DISPLACED WELL SOUTHWARD TO PRECLUDE ANY THUNDER MENTION...BUT THIS SHOULD START TO CHANGE DURING THE AFTERNOON AS STRONGER UPPER FORCING WILL COMBINE WITH INCREASE IN ISENTROPIC LIFT TO BULGE PRECIPITATION BACK NORTHWARD THROUGH THE MISSOURI RIVER CORRIDOR ALONG WITH WEAK ELEVATED INSTABILITY FOR AN ISOLATED THUNDER MENTION. GOING THROUGH MONDAY NIGHT AND TUESDAY...LARGER SCALE BROAD ISENTROPIC LIFT WILL SPREAD GRADUALLY NORTHWARD TO THE NORTH OF STRONG SURFACE WARM FRONT LIFTING GRADUALLY NORTH OF I-80. MOST SOLUTIONS DO SUGGEST THAT MAY SEE A MIDDAY MINIMA IN QG SUPPORT FOR PRECIP WITH RIDGING STRENGTHENING ALOFT TO EAST...AND AHEAD OF NEXT LOBE EJECTING FROM SOUTHERN ROCKIES CLOSED LOW PUSHING TOWARD WESTERN CWA. HOWEVER...WITH PERSISTENT ISENTROPIC LIFT...EXPECT AT LEAST A SCATTERING OF SHOWERS TO BE PRESENT. INSTABILITY IS JUST TO THE WEAK SIDE OF NEUTRAL...SO THUNDER WILL BE FAR FROM PREDOMINANT IN COVERAGE...AND HAVE GENERALLY KEPT A CATEGORY OR TWO BELOW ANY PRECIP MENTION. ON TUESDAY NIGHT...COULD ACTUALLY SEE A DECREASE IN COVERAGE OF PRECIP CYCLING NORTHWARD THROUGH THE EASTERN CWA...WITH MAIN ISENTROPIC BAND LIFTING NORTH OF THE CWA...AND LULL AHEAD OF MOISTURE CONVEYOR LOBE WHICH WILL WRAP RAPIDLY NORTH AND EASTWARD TOWARD THE MISSOURI VALLEY BY LATE NIGHT. THE MAIN DYNAMIC FORCING WILL SWING NORTHEASTWARD LATER WEDNESDAY AND WEDNESDAY NIGHT AS UPPER LOW LIFTS FROM COLORADO THROUGH THE DAKOTAS...AND SHOULD FOCUS PERIOD OF MOST SIGNIFICANT RAINFALL ACROSS THE AREA. INSTABILITY JUST A BIT STRONGER...BUT DEEP LAYER SHEAR IS QUITE MINIMAL...SO PROSPECT OF SEVERE STORMS MINIMAL WITH WAVE OUT OF PHASE WITH DIURNAL CYCLE AS WELL. THURSDAY WILL SEE THE LOW LEVEL BOUNDARY PUSHING EASTWARD ACROSS THE CWA AS UPPER LOW LIFTS NORTH OF THE REGION. DEPENDING ON TIMING OF BOUNDARY...DEGREE OF POTENTIAL WARMING AHEAD...MAY SEE SEVERE PARAMETERS FALL OUT A BIT STRONGER NEAR FRONTAL ZONE. MUCH OF THE TUESDAY TO THURSDAY PERIOD WILL HAVE QUITE A BIT OF CLOUDINESS AND MOISTURE...WITH LOWER DIURNAL RANGE. STILL SHOULD SEE TEMPS AT OR ABOVE NORMAL WITH UPPER 60S TO MID 70S COMMON FOR HIGHS...AND 50S TO AROUND 60 FOR LOWS. THE END OF THE LONGER RANGE FOR THURSDAY THROUGH SATURDAY CONTINUES TO ADVERTISE SOME SIGNIFICANT DIFFERENCES IN DETAILS...WHILE A LARGER SCALE AGREEMENT OF WESTERN TROUGHING TO EASTERN PLAINS RIDGING REMAINS IN PLAY. ECMWF/CANADIAN SUGGEST A BIT MORE SOUTHWARD AND QUICKER PUSH TO BAROCLINIC ZONE BY THURSDAY NIGHT AND FRIDAY RESULTING IN A DRIER PERIOD PERHAPS LASTING INTO SATURDAY...AND WOULD NOT BE SURPRISED TO HAVE THINGS SHAKE OUT IN THAT MANNER. ANOTHER FAIRLY STRONG LOBE WILL BE MOVING IN JUST BEYOND THE END OF THE FORECAST PERIOD...AND MAY HAVE SOMEWHAT SLIGHTLY BETTER SHEAR AND INSTABILITY AT HAND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 147 PM CDT SUN MAY 3 2015 CONVECTIVE CHANCES THROUGH THE AFTERNOON/EARLY EVENING...ALONG WITH GUSTY POST-FRONTAL SURFACE WINDS...ARE PRIMARY CONCERNS FOR THIS TAF PERIOD. CONVECTIVE THREAT SOMEWHAT ILL-DEFINED AS COOL FRONT WORKS THROUGH MODERATELY UNSTABLE AIR MASS IN NORTHWEST IOWA THIS AFTERNOON. SCATTERED THUNDERSTORMS STILL APPEAR POSSIBLE IN AREAS SOUTH/EAST OF KFSD AND WILL MAINTAIN DRY FORECAST FOR KFSD AS THIS POINT...THOUGH POTENTIAL FOR ISOLATED ELEVATED SHRA/TSRA FOR AN HOUR OR TWO IN THE LATE AFTERNOON. GREATER CHANCE FOR THE KSUX AREA IN THE EARLY EVENING AS ELEVATED FRONT WORKS THROUGH THE AREA. LATE AFTERNOON/EVENING THUNDERSTORM ACTIVITY COULD PRODUCE VARIABLE GUSTY WINDS...POSSIBLY IN EXCESS OF 40KT...THOUGH LOWER CONFIDENCE IN TIMING/LOCATION OF WIND THREAT PRECLUDES MENTION IN TAFS AT THIS TIME. POST-FRONTAL WINDS GUSTING 20-30KT MORE WIDESPREAD AND EXPECTED TO PERSIST INTO THE EVENING BEFORE DIMINISHING AFTER DARK. && .FIRE WEATHER... ISSUED AT 358 AM CDT SUN MAY 3 2015 HIGH TO VERY HIGH FIRE DANGER EXPECTED TODAY...PRIMARILY ALONG AND WEST OF A MARSHALL TO YANKTON LINE. THE DRIVING FORCE BEHIND TODAYS HIGH FIRE DANGER WILL BE STRONG POST FRONTAL WINDS UP TO 20 KNOTS AT TIMES. THE AIR IMMEDIATELY BEHIND THE INCOMING FRONTAL BOUNDARY WILL NOT BE ALL THAT DRY...SO RH VALUES WILL ONLY FALL TO AROUND 25 TO 30 PERCENT. THUS...NOT ANTICIPATING RED FLAG WARNING CONDITIONS BUT ANY BURNING SHOULD BE DONE WITH CAUTION. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ UPDATE...JH SHORT TERM...DUX LONG TERM...CHAPMAN AVIATION...JH FIRE WEATHER...DUX
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
322 PM MDT SUN MAY 3 2015 .SYNOPSIS... AFTER THREE DAYS OF VERY WARM TEMPERATURES...THE BORDERLAND WILL SEE A COOLER STRETCH OF WEATHER AS A SERIES OF UPPER LOWS TRACK ACROSS THE SOUTHERN U.S. MOISTURE AND INSTABILITY WILL CONTINUE TONIGHT AND MONDAY...ALLOWING ISOLATED THUNDERSTORMS THROUGH MONDAY NIGHT. LOW LEVEL MOISTURE BEGINS DECREASING TUESDAY...THOUGH A SLIGHT CHANCE OF THUNDERSTORMS WILL CONTINUE EAST OF EL PASO. WEDNESDAY THROUGH SATURDAY SHOULD SEE PLENTY OF SUNSHINE...WITH HIGHS REMAINING NEAR NORMAL. && .DISCUSSION... LOOKS LIKE WE ARE ENTERING A COOLER PHASE OF WEATHER THOUGH NOT MUCH WETTER. WV IMAGERY SHOWING DEEPER LAYERED MOISTURE NOW OFF TO OUR EAST AS LARGE DRY SLOT WITH PW`S OF AROUND .4 TO .6 INCHES MOVES OVER THE AREA. HOWEVER IMAGERY DOES APPEAR TO SHOW SEVERAL WEAK DISTURBANCES TRACKING ACROSS THE BAJA TO FAR SOUTHERN ARIZONA AND SOUTHERN NEW MEXICO...ASSOCIATED WITH STRONG 130 KT JET. THE COMBINATION OF THE MODERATE MOISTURE AND DISTURBANCES SHOULD BE ENOUGH TO CONTINUE ISOLATED SHOWERS/THUNDERSTORMS TONIGHT AND MONDAY ACROSS THE CWA. VISIBLE SATELLITE SHOWS CONSIDERABLE CU GROWTH WITH NICE AMOUNT OF TCU/CB. LIGHTNING LOOKS TO BE LIMITED TO MOSTLY DEMING WEST AND ALSO OVER HUDSPETH CO AT THIS TIME. EXPECT THESE ISOLATED TSTMS TO CONTINUE MONDAY...PERHAPS BECOMING SCATTERED OVER THE MOUNTAINS. HRRR SHOWING DCAPES OF 700-900 J/KG...COMBINED WITH DEW POINT DEPRESSIONS OF 50-55 DEG...WILL GIVE SOME WIND GUST POTENTIAL OF 45 TO 55 MPH NEAR ANY SHOWERS TONIGHT. LARGE DEPRESSIONS SHOULD LIMIT ANY RAINFALL AMOUNTS TO QUITE MODEST TOTALS. TUESDAY...MODELS SHOW WHAT LITTLE LOW LEVEL MOISTURE REMAINS...TO BEGIN SCOURING OUT FROM THE WEST AS UPPER LOW PASSES THROUGH NEW MEXICO. LEFT LOW POPS IN FAR EAST IN CASE MOISTURE REMAINS INTO HEATING PERIOD. FLOW TURNS SOUTHWEST WEDNESDAY INTO SATURDAY AHEAD OF A BROAD UPPER TROUGH SLOWLY MOVING ONSHORE OF THE WEST COAST. PATTERN LOOKS LIKE IT SHOULD BE WARM...BUT MODELS NEVER REALLY DEVELOP STRONG LEE SIDE TROUGHING TO DEVELOP WARM SOUTHWEST WINDS. SO HIGH TEMPS LOOK TO REMAIN AROUND NORMAL LAST HALF OF THE WEEK. NICE DAYS WITH SEASONABLE TEMPS AND YET NOT MUCH IN THE WAY OF WINDS. && .AVIATION...VALID 04/00Z-05/00Z... VFR CONDS THRU PD. P6SM SCT-BKN080-100 BKN150-200 WITH ISOLD TO SCT VRB25G40KT -TSRA BKN070-090 THRU 04Z AND AGAIN AFT 18Z. GENERALLY W TO SW WINDS UNDER 12KTS THRU 20Z...THEN INCREASING TO 12-18G25KTS. && .FIRE WEATHER... AN UPPER LEVEL TROUGH WILL BE LIFTING OUT OF THE SOUTHWEST OVER THE NEXT COUPLE OF DAYS. THIS WILL BRING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TO THE REGION. THERE WILL BE SOME DRY LIGHTNING POSSIBLE AS TEMP-DEW POINT SPREAD WILL BE AROUND 50 DEGREES INTO THE EARLY EVENING AND AROUND 45 DEGREES ON MONDAY. WINDS WILL ALSO START TO INCREASE MONDAY AFTERNOON OUT OF THE SOUTHWEST AT 15 TO 20 MPH. TEMPERATURES WILL COOL DOWN ON THE BACK SIDE OF THIS SYSTEM INTO THE UPPER 70S TO LOWER 80S BUT RELATIVE HUMIDITIES WILL STAY AT OR BELOW 15 PERCENT FOR MOST LOWLAND LOCATIONS THROUGH THE UPCOMING WEEK. && .PRELIMINARY POINT TEMPS/POPS... EL PASO 62 86 60 82 58 / 10 10 20 0 0 SIERRA BLANCA 57 83 54 82 54 / 20 10 40 0 0 LAS CRUCES 53 83 51 81 50 / 10 10 20 0 0 ALAMOGORDO 56 83 54 81 53 / 10 20 30 0 0 CLOUDCROFT 45 63 42 60 40 / 20 50 50 30 0 TRUTH OR CONSEQUENCES 53 81 50 79 50 / 10 20 20 10 0 SILVER CITY 48 75 46 72 45 / 10 20 30 20 0 DEMING 51 83 48 81 48 / 10 10 20 0 0 LORDSBURG 52 81 48 80 48 / 10 20 20 10 0 WEST EL PASO METRO 61 85 60 82 59 / 10 10 20 0 0 DELL CITY 55 85 54 81 52 / 20 20 40 20 0 FORT HANCOCK 58 87 56 83 55 / 20 10 30 0 0 LOMA LINDA 58 81 58 79 56 / 10 10 30 0 0 FABENS 57 86 55 82 54 / 10 10 30 0 0 SANTA TERESA 57 85 55 82 54 / 10 10 20 0 0 WHITE SANDS HQ 60 82 58 81 57 / 10 20 20 0 0 JORNADA RANGE 52 83 50 81 48 / 10 20 20 0 0 HATCH 53 83 50 82 49 / 10 20 20 0 0 COLUMBUS 55 81 54 81 53 / 10 10 20 0 0 OROGRANDE 59 84 57 82 57 / 10 20 30 0 0 MAYHILL 51 72 48 70 46 / 20 50 50 30 0 MESCALERO 49 72 45 70 43 / 20 50 50 30 0 TIMBERON 50 71 47 69 45 / 20 50 50 20 0 WINSTON 44 71 44 73 41 / 20 30 40 30 0 HILLSBORO 50 80 48 79 46 / 10 20 20 20 0 SPACEPORT 50 82 48 81 48 / 10 20 30 0 0 LAKE ROBERTS 44 74 44 71 42 / 10 30 30 30 0 HURLEY 47 76 47 75 44 / 10 10 20 20 0 CLIFF 46 80 42 78 42 / 10 20 20 30 0 MULE CREEK 42 78 39 75 39 / 20 20 20 30 0 FAYWOOD 49 77 47 76 46 / 10 10 20 20 0 ANIMAS 51 80 48 81 49 / 10 20 20 0 0 HACHITA 49 81 47 81 48 / 10 10 20 0 0 ANTELOPE WELLS 49 80 46 80 48 / 10 10 20 0 0 CLOVERDALE 48 78 47 77 47 / 10 10 10 0 0 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...NONE. TX...NONE. && $$ HEFNER/GRZYWACZ
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1154 AM CDT SUN MAY 3 2015 .AVIATION... 18Z TAF CYCLE AN UPPER LOW WILL APPROACH THE PANHANDLES FROM THE WEST THROUGH MONDAY AND A FRONTAL BOUNDARY WILL PUSH INTO THE NORTHWEST SECTIONS OF THE PANHANDLES TONIGHT AND MONDAY. CONVECTION WILL DEVELOP AND MOVE EAST OUT OF NEW MEXICO THIS AFTERNOON AND TONIGHT OR DEVELOP ACROSS MAINLY THE WESTERN HALF OF THE PANHANDLES. WILL MENTION VCTS AT ALL THREE TAF SITES FOR NOW BETWEEN ABOUT 00Z MONDAY AND 08Z MONDAY WITH VFR CONDITIONS. LIGHT MOSTLY WEST AND SOUTHWEST WINDS 5 TO 15 KNOTS WILL INCREASE FROM THE SOUTH 10 TO 20 KNOTS WITH SOME HIGHER GUSTS POSSIBLE AFTER 20Z TODAY...THEN DIMINISHING TO AROUND 5 TO 15 KNOTS FROM THE SOUTH AND SOUTHEAST AFTER 00Z MONDAY. SCHNEIDER && .PREV DISCUSSION... /ISSUED 618 AM CDT SUN MAY 3 2015/ AVIATION... MORE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EVENING ACROSS MUCH OF THE PANHANDLES. BUT WILL NOT MENTION THUNDERSTORMS AT THE TAF SITES AS THE COVERAGE WILL NOT BE WIDESPREAD ENOUGH TO MENTION AT THIS TIME. SKIES WILL REMAIN VFR...UNLESS A TAF SITE TAKES A DIRECT HIT FROM A THUNDERSTORM...THEN CONDITIONS WILL LIKELY DROP INTO THE MVFR RANGE. GUSTY SOUTHERLY WINDS WILL GRADUALLY DECREASE WITH SUNSET. PREV DISCUSSION... /ISSUED 520 AM CDT SUN MAY 3 2015/ DISCUSSION... NO SIGNIFICANT CHANGES WERE NEEDED TO THE PREVIOUS FORECAST. CURRENT WATER VAPOR AND RAP ANALYSIS SHOW AN UPPER LOW CURRENTLY OFF THE CALIFORNIA COAST MOVING EASTWARD. THIS WILL BE THE IMPETUS FOR WIDESPREAD POTENTIALLY HEAVY RAINFALL EARLY NEXT WEEK ACROSS THE ENTIRE FORECAST AREA. BROAD BUT WEAK UPPER LEVEL RIDGING IS PRESENT OVER THE SOUTH-CENTRAL UNITED STATES AND WILL HAVE LESS INFLUENCE ON OUR WEATHER AS IT CONTINUES TO WEAKEN AND SHIFT EASTWARD. INITIAL PRECIPITATION CHANCES WILL BE TIED TO DIURNAL CYCLE AND OROGRAPHIC EFFECTS OF THE HIGH TERRAIN IN NEW MEXICO WITH CONVECTION BECOMING FAIRLY NUMEROUS THERE BY EARLY/MID AFTERNOON. MEAN WESTERLY FLOW WILL REMAIN RATHER WEAK RESULTING IN SLOW EASTWARD PROGRESSION OF THIS CONVECTION. FURTHER EAST ONTO THE NEW MEXICO PLAINS AND ACROSS AT LEAST THE WESTERN PORTION OF THE PANHANDLES...DEEP MIXING DURING THE AFTERNOON SHOULD BE SUFFICIENT FOR SCATTERED HIGH BASED CONVECTION TO DEVELOP. DEEP DRY SUB-CLOUD LAYER WILL LIMIT PRECIPITATION AMOUNTS BUT COULD RESULT IN STRONG WIND GUSTS WITH THE MOST ROBUST CONVECTION. CONVECTION SHOULD SLOWLY WEAKEN DURING THE EVENING AND EARLY SUNDAY NIGHT. UPPER FLOW BECOMES INCREASINGLY DIFLUENT ON MONDAY AS THE UPPER LOW APPROACHES. EVEN EARLY IN THE DAY SUFFICIENT LARGE SCALE FORCING AND MOISTURE ADVECTION IS PRESENT TO JUSTIFY AT LEAST LOW PRECIPITATION PROBABILITIES PRIMARILY ACROSS THE WESTERN HALF OF THE AREA. 00Z RAOB FROM COASTAL TEXAS OFFICES STILL LACK DEEP MOISTURE BUT LATEST SATELLITE DERIVED TPW SHOWS INCREASING MOISTURE ACROSS THE WESTERN GULF. MODEL GUIDANCE IS INSISTENT ON A SURGE OF LOW LEVEL MOISTURE AND ABOVE CLIMO PWAT VALUES INTO THE AREA BY LATE MONDAY WITH STRENGTHENING LEE TROUGH AND SOUTHERLY WINDS. THIS INCREASE IN MOISTURE COMBINED WITH THE ABOVE MENTIONED LARGE SCALE FORCING SHOULD RESULT IN WIDESPREAD RAIN. SPATIAL AND TEMPORAL DETAILS OF HEAVY RAIN AND POTENTIAL FLOODING ARE STILL A BIT UNCLEAR BUT THE PATTERN FITS THESE THREATS. ONE TO THREE INCHES SEEMS LIKELY. THE MAJORITY OF THE RAINFALL WILL OCCUR MONDAY NIGHT THROUGH THE FIRST HALF OF TUESDAY. SEVERE THUNDERSTORM POTENTIAL SHOULD BE MOST LIKELY...ALBEIT STILL RELATIVELY LOW AND MARGINAL...MONDAY AFTERNOON AND EVENING COINCIDENT WITH LOW LEVEL MOISTURE SURGE BENEATH STEEPENING MID LEVEL LAPSE RATES. THIS SHOULD YIELD AT LEAST MARGINAL INSTABILITY AND DEEPER/STRONGER CONVECTION THAN THE PREVIOUS DAY. EFFECTIVE SHEAR MAY BE MARGINAL FOR STORM ORGANIZATION THOUGH. SIGNIFICANT CONVECTIVE OVERTURNING SHOULD WEAKEN MID LEVEL LAPSE RATES ON TUESDAY PRECLUDING A NOTEWORTHY SEVERE WEATHER THREAT ALTHOUGH IF POCKETS OF INSTABILITY CAN DEVELOP SOME STRONG TO SEVERE THUNDERSTORMS WOULD BE POSSIBLE. ONE OF THE FEW CHANGES THAT WERE MADE TO THE FORECAST WAS TO LOWER HIGH TEMPERATURES ON TUESDAY TO ACCOUNT FOR WIDESPREAD CLOUDS AND PRECIPITATION THAT WILL LIKELY LIMIT THE MAGNITUDE OF DIURNAL HEATING. AS UPPER LOW/OPENING WAVE DEPARTS...WEAK SHORTWAVE RIDGING WILL BRIEFLY INFLUENCE THE AREA RESULTING IN A MOSTLY DRY DAY AND TEMPERATURES RETURNING TO THE UPPER 70S AND LOWER 80S. A DEEP CLOSED LOW WILL EVOLVE ALONG THE WEST COAST BY THURSDAY AND WITH STRENGTHENING MEAN SOUTHWESTERLY FLOW LEE TROUGHING WILL PERSIST/STRENGTHEN. MULTIPLE DAYS OF DRYLINE CONVECTION MAY OCCUR FROM LATE WEEK THROUGH THE WEEKEND WITH HIGHEST PRECIPITATION PROBABILITIES ACROSS THE EASTERN HALF OF THE AREA. SPREAD IN THE ENSEMBLE AND UNCERTAINTY WITH TIMING OF SMALL LEAD WAVES AND EASTWARD PROGRESSION OF UPPER LOW MAKES IT DIFFICULT TO DELINEATE WHEN THE HIGHEST PROBABILITY OF PRECIPITATION WILL BE. SUBSEQUENT FORECASTS WILL REFINE THESE DETAILS. BRB && .AMA WATCHES/WARNINGS/ADVISORIES... TX...NONE. OK...NONE. && $$ 11/14
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE

.SHORT TERM...TONIGHT AND MONDAY ISSUED AT 327 PM CDT SUN MAY 3 2015 TIMING AND INTENSITY OF THUNDERSTORMS ARE THE MAIN CONCERNS DURING THIS PART OF THE FORECAST. A COLD FRONT MOVED INTO EXTREME NORTHWEST WISCONSIN THIS AFTERNOON AND RADAR AND LIGHTNING DETECTION DATA INDICATED A LINE OF THUNDERSTORMS AHEAD OF THE FRONT ACROSS THE FAR NORTHWEST PART OF THE STATE...ALONG WITH WIDESPREAD CONVECTION IN UPPER MICHIGAN...AT 1945Z. LOCAL MESOANALYSIS GRAPHICS WERE SHOWING 1000+J/KG OF MUCAPE IN NORTH CENTRAL WISCONSIN WITH LITTLE TO NO CIN SINCE ABOUT 16Z. BY 19Z MUCAPE VALUES ACROSS MOST OF THE REST OF THE AREA WERE MAINLY IN THE 250-1000J/KG RANGE...WITH LESS THAN 250J/KG GENERALLY EAST OF A LINE FROM ABOUT WAUSAUKEE TO OSHKOSH. WOULD EXPECT STORMS TO CONTINUE AS THE FRONT REACHES THE UNSTABLE AIR IN THE NORTHERN PART OF THE STATE. 12Z MODELS GENERALLY SHOWED QPF SPREADING ACROSS THE ENTIRE AREA BETWEEN 18Z AND 00Z MONDAY. BUT MESOSCALE MODELS...ARW/HRRR...DID NOT HAVE PRECIPITATION REACHING NORTH CENTRAL WISCONSIN UNTIL SHORTLY BEFORE 00Z MONDAY WITH ONLY ISOLATED SMALL VALUES OF QPF ACROSS THE REST OF THE AREA. MESO MODELS APPEARED TO BE DOING A BETTER JOB OF HANDLING THE SITUATION SO HAVE SLOWED THE PROGRESSION OF THE CONVECTION ACROSS THE AREA. SPC HAS KEPT THE MAJORITY OF THE AREA IN A SLIGHT RISK FOR SEVERE STORMS THIS AFTERNOON AND EVENING. WBZ HEIGHTS AT 20Z RANGED FROM LESS THAN 7500FT IN NORTH CENTRAL WISCONSIN TO MORE THAN 9000FT IN EAST CENTRAL WISCONSIN. 0-6KM SHEAR ACROSS THE NORTH WAS MAINLY 25-35KTS. THERE IS NOT QUITE AS MUCH INSTABILITY AS MODELS SHOWED YESTERDAY...SHEAR WAS NOT ALL THAT IMPRESSIVE AND THERE IS NOT A LOT OF UPPER SUPPORT AVAILABLE...SO STRENGTH OF THE STORMS IS A BIT UNCERTAIN. .LONG TERM...MONDAY NIGHT THROUGH SUNDAY ISSUED AT 327 PM CDT SUN MAY 3 2015 THE TRAILING END OF THE COLD FRONT WILL STALL OVER NORTHERN ILLINOIS AND SERVE AS A WEAK FOCAL POINT FOR SHOWERS DURING THE FIRST HALF OF THE WEEK AS IT GRADUALLY PUSHES NORTH-NORTHEAST OVER WISCONSIN AND WASHES OUT. MEANWHILE...A BROAD SFC-500MB HIGH PRESSURE RIDGE WILL SPREAD IN FROM THE WEST AS THE WEEK PROGRESSES. THE RIDGE AXIS WILL MOVE EAST OF WISCONSIN BY THE END OF THE WORK WEEK. GFS AND ECMWF MODELS ARE IN AGREEMENT THAT WISCONSIN WILL THEN REMAIN UNDER THE UNSTABLE WEST SIDE OF THE RIDGE THROUGH THE WEEKEND...ENABLING GULF MOISTURE TO ADVECT INTO WISCONSIN FROM THE SOUTHWEST...ALONG WITH A DISTURBANCE OR TWO. ML. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 104 PM CDT SUN MAY 3 2015 CONDITIONS WERE VFR ACROSS THE AREA AT MIDDAY AS A COLD FRONT WAS JUST ENTERING THE NORTHWEST CORNER OF WISCONSIN. CONFIDENCE HAS WANED WITH REGARD TO FORECAST OF CONVECTION ACROSS THE AREA THIS AFTERNOON INTO MONDAY MORNING. ONLY MADE MINOR ADJUSTMENTS TO TIMING FROM THE PREVIOUS FORECAST FOR NOW. THE MOST UNSTABLE CONDITIONS APPEARED TO BE ACROSS NORTH CENTRAL WISCONSIN WHERE MUCAPE VALUES WERE 500+ J/KG WITH LITTLE TO NO CIN THERE...BUT NO CONVECTION WAS YET EVIDENT IN THAT AREA. SHOWERS AND ISOLATED THUNDERSTORMS WERE CONFINED TO MINNESOTA AND EASTERN LAKE SUPERIOR AT 1745Z. MOST OF THE 12Z MODELS SHOWED QPF WITH THE FRONT GREATLY EXPANDING DURING THE AFTERNOON TO COVER THE ENTIRE AREA. A QUICK LOOK AT THE 16Z HRRR INDICATED ISOLATED-SCATTERED LIGHT QPF UNTIL A MORE SOLID AREA OF PRECIPITATION REACHES NORTH CENTRAL WISCONSIN. THIS LOOKS LIKE ITS ON TRACK...AT LEAST RIGHT NOW...SO MAINLY VFR AND DRY THE REST OF THE DAY IF IT REMAINS ON TRACK. CANNOT RULE OUT CONVECTIVE DEVELOPMENT WITH SPC DAY 1 SEVERE OUTLOOK INCLUDING MUCH OF THE AREA IN A SLIGHT RISK FOR SEVERE...WITH POSSIBLE DAMAGING WINDS AND LARGE HAIL THIS AFTERNOON AND TONIGHT. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MG LONG TERM......ML AVIATION.......MG
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
104 PM CDT SUN MAY 3 2015 UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE .SHORT TERM...TODAY...TONIGHT...AND MONDAY ISSUED AT 338 AM CDT SUN MAY 3 2015 THUNDERSTORM TIMING TODAY INTO TONIGHT AS WELL AS POTENTIAL OF SEVERE STORMS THE PRIMARY ISSUE FOR THIS PERIOD. RADARS THIS MORNING SHOW SCATTERED SHOWERS AND STORMS OVER MINNESOTA AHEAD OF THE COLD FRONT AND ANOTHER CLUSTER OF SHOWERS AND STORMS OVER IOWA ASSOCIATED WITH A WEAK SHORT WAVE DRIFTING IN THE WEST TO SOUTHWEST FLOW. THIS IOWA SHORT WAVE TROUGH IS PROGGED TO STAY SOUTH BUT DID NOTICE SOME MID LEVEL CLOUDS GRADUALLY DRIFTING NORTHEASTWARD INTO SOUTHWEST WISCONSIN. PROGS OVERALL KEEP THIS CONVECTION SOUTH BUT A FEW DO EXTEND SOME LIGHT AMOUNTS INTO PARTS OF CENTRAL AND EAST CENTRAL WISCONSIN LATER THIS MORNING. OTHERWISE THE BRUNT OF THE CONVECTION TODAY WILL BE WITH THE CONVERGENCE GENERATED ALONG THE COLD FRONT. UPPER JET SUPPORT WELL NORTH OF THE AREA. WILL HAVE AN EARLIER START TIME OF THE CONVECTION AROUND MID DAY FOR NORTH CENTRAL DUE TO POSSIBLE EARLY MORNING MINNESOTA CONVECTION MAY HOLD TOGETHER AND REACH THIS AREA. STRONGEST STORMS WILL LIKELY ARRIVE MID TO LATE AFTERNOON OVER NORTH CENTRAL WISCONSIN AND CENTRAL WISCONSIN DURING PEAK HEATING PERIOD. SPC CONTINUES TO PLACE MUCH OF CENTRAL AND NORTH CENTRAL IN A SLIGHT RISK. SOME MODEL ISSUES WITH RESPECT TO AVAILABLE INSTABILITY DUE TO SURFACE DEWPOINTS TRENDS...NAM PRODUCES UP TO 2000 J/KG CAPES LATE THIS AFTERNOON OVER CENTRAL AND NORTH CENTRAL WISCONSIN WHILE THE GFS FORECAST SOUNDINGS ARE BETWEEN 100O TO 1500. SOME LOWER TO MID 50S NOTED OVER THE CENTRAL PLAINS AND ANTICIPATE SIMILAR VALUES LATER TODAY ALONG AND JUST AHEAD OF THE COLD FRONT. CAPES OF 1000 TO 1500 J/KG WILL BE WORKING WITH AN INCREASINGLY SHEARED ENVIRONMENT DUE TO THE MID LEVEL WESTERLY FLOW. BY THE TIME THE STORMS REACH EAST CENTRAL WISCONSIN LATER THIS EVENING...INSTABILITY DUE TO DAYTIME HEATING WILL DIMINISH...BUT THE WESTERLY MID LEVEL WINDS WILL WORK INTO THE AREA AS THE COLD FRONT PASSES. THE LINGERING SHEARED ENVIRONMENT MAY BE ENOUGH TO MAINTAIN A FEW NEAR SEVERE STORMS THIS EVENING OVER EAST CENTRAL WISCONSIN. SHOWERS AND STORMS WILL BE ON THE DECREASE AFTER MIDNIGHT AND TOWARD MONDAY MORNING AFTER FROPA. HIGH PRESSURE WILL BUILD INTO NORTHWEST WISCONSIN MONDAY FOR SUNNY SKIES ACROSS THE NORTH. SINCE THE COLD FRONT STALLS OVER NORTHERN OR CENTRAL ILLINOIS...CLOUDS MAY HANG AROUND OVER EAST CENTRAL WISCONSIN. NORTHEAST WINDS OFF THE LAKE MAY ALSO CONTRIBUTE TO LOWER LEVEL CLOUDS MONDAY. DUE TO CLOUDS SUNDAY NIGHT...AND A WARM START MONDAY MORNING AND DECREASING CLOUDS MONDAY...FORECAST MAX TEMPERATURES MAY REBOUND INTO AT LEAST THE LOWER 70S AWAY FROM LAKE MICHIGAN AND THE BAY. .LONG TERM...MONDAY NIGHT THROUGH SATURDAY ISSUED AT 338 AM CDT SUN MAY 3 2015 AMPLIFIED MEAN FLOW TO PERSIST THRU MUCH OF THE WEEK WITH A BROAD UPR TROF OVER THE WRN CONUS AND AN UPR RDG OVER THE SE CONUS. THIS PATTERN WOULD BRING A PREVAILING SW FLOW TO THE CNTRL CONUS (INCLUDING WI) WHICH WL KEEP TEMPS ABOVE NORMAL AND ALLOW GULF MOISTURE TO EASILY FLOW NWD. AN ACTIVE WEATHER PERIOD IS EXPECTED FOR NE WI AS A WRMFNT MOVES THRU THE AREA LATE TUE INTO WED... FOLLOWED BY A WEAKENING SHORTWAVE TROF/SFC CDFNT LATE IN THE WEEK. THE EXPECTED PCPN SHOULD HELP TO ALLEVIATE THE DRY CONDITIONS/FIRE DANGER OVER THE REGION. THE SFC HI WL SLOWLY SHIFT TOWARD NE SECTIONS OF THE GREAT LAKES TUE NGT...BUT KEEP A DRY E-NE WIND OVER THE FCST AREA. MEANWHILE... WL BE WATCHING THE STALLED BOUNDARY TO OUR SOUTH WHICH MAY EDGE A BIT NORTH IN RESPONSE TO AN INCREASING LOW-LEVEL JET OVER THE PLAINS. NRN WI TO REMAIN MOSTLY CLEAR THRU THE NGT...HOWEVER EXPECT CNTRL/E-CNTRL WI TO BECOME PARTLY TO MOSTLY CLOUDY OVRNGT AND CANNOT RULE OUT A FEW LIGHT SHWRS REACHING OUR SRN TIER OF COUNTIES TOWARD DAYBREAK AS ADDITIONAL SHWRS/TSTMS MOVE ALONG THE FRONTAL BOUNDARY. MIN TEMPS TO RANGE FROM THE LWR TO MID 30S NEAR THE MI BORDER...TO THE LWR TO MID 40 SOUTH. MODELS SEEM CONVINCED NOW THAT THE STALLED BOUNDARY WL BEGIN TO STEADILY LIFT NORTH AS A WRMFNT ON TUE IN RESPONSE TO A SIGNIFICANT SHORTWAVE TROF MOVING NEWD THRU THE SRN ROCKIES. THE FNT IS EXPECTED TO STRETCH ROUGHLY FROM SRN MN E-SE THRU THE WI/IL BORDER BY 00Z WED WITH CONVERGENCE ALONG THE FNT/GULF MOISTURE LIFTING OVER THE FNT LEADING TO MORE SHWR/TSTM ACTIVITY. MAY NEED TO BRING POPS NORTH A TIER OF COUNTIES...LEAVING ONLY FAR NRN WI DRY THRU THE DAYLIGHT HOURS. MORE CLOUDS/HIGHER POPS WL LEAD TO A COOLER DAY WITH MAX TEMPS RANGING FROM THE LWR 60S SOUTH (COOLER LAKESIDE)...TO NEAR 70 DEGS ALONG THE MI BORDER. CHC OF SHWRS/TSTMS WL CONT ACROSS NE WI TUE NGT AS THE WRMFNT SLOWLY LIFTS NORTH INTO SRN WI. AS THE SHORTWAVE TROF MOVES TOWARD THE CNTRL PLAINS ON WED...THE WRMFNT WL CONT TO LIFT NWD THRU WI AND ESSENTIALLY BE NORTH OF THE FCST AREA BY LATE WED. ANTICIPATE AT LEAST A CHC OF SHWRS/TSTMS TO ACCOMPANY THE WRMFNT...BUT BELIEVE THE PCPN WL HAVE A TENDENCY OF BECOMING MORE ISOLATED IN NATURE ACROSS CNTRL/E-CNTRL WI WED AFTERNOON AS THE MAIN FOCUS SHIFTS NORTH WITH THE FNT AND THERE IS A LACK OF ANY TRIGGER IN THE SOUTH. WED WL FEEL MORE LIKE A SUMMER DAY WITH MAX TEMPS RANGING FROM AROUND 70 DEGS NORTH...UPR 70S CNTRL WI (COOLER NEAR LAKE MI) AND DEW POINTS CLIMBING INTO THE 50S. THE SHORTWAVE TROF IS PROGGED TO MOVE THRU THE CNTRL PLAINS WED NGT AND BEGIN TO WEAKEN IN THE PROCESS. BY THU...WHAT IS LEFT OF THE TROF WL REACH THE UPR MS VALLEY WITH A CDFNT EXTENDED SW THRU THE CNTRL PLAINS. PCPN CHCS APPEAR MINIMAL WED NGT INTO THU MORNING...HOWEVER AS BETTER MID-LEVEL FORCING/INCREASING INSTABILITY BECOME MORE PREVALENT THU AFTERNOON...PCPN CHCS LOOK TO BE ON THE INCREASE ONCE AGAIN. GUSTY SOUTH WINDS ON THU WL CONT TO PUMP GULF MOISTURE INTO WI WITH DEW POINTS EXPECTED TO BE IN THE MID TO UPR 50S. COMBINE THESE DEW POINTS WITH MAX TEMPS IN THE 75-80 DEG RANGE (AWAY FROM LAKE MI) AND WE WL HAVE A SUMMER FEEL TO THE AIR MASS. PCPN CHCS WL CONT THU NGT AS STRONGER WAA SURGES THRU WI AHEAD OF THE ADVANCING CDFNT. THIS CDFNT IS FCST TO PUSH INTO WI ON FRI AND SET THE STAGE FOR ADDITIONAL SHWRS/TSTMS. TOO EARLY TO DETERMINE THE STRENGTH OF THESE STORMS...BUT WITH THE MODELS SHOWING LITTLE IN THE WAY OF MID OR UPR SUPPORT...THIS WOULD LIMIT THE SEVERE RISK. MAX TEMPS ON FRI SHOULD BE A FEW DEGS COOLER THAN THU DUE TO THICKER CLOUDS/HIGHER CHC OF PCPN. JUST LIKE ITS PREDECESSOR...THIS CDFNT IS FCST TO SAG SOUTH AND EVENTUALLY STALL SOMEWHERE IN THE VICINITY OF THE WI/IL BORDER NEXT WEEKEND. THE EXACT LOCATION OF THIS BOUNDARY WL ULTIMATELY DETERMINE THE NRN EXTENT OF ANY PCPN IN THE VICINITY OF CNTRL/E-CNTRL WI. FOR THE MOST PART...NRN WI REMAIN DRY NEXT SAT AS HI PRES OVER SRN CANADA FEEDS DRIER AIR INTO NRN SECTIONS OF THE GREAT LAKES. SAT WL ALSO BE COOLER BEHIND THE INITIAL CDFNT WITH MAX TEMPS RANGING ONLY IN THE MID 50S LAKESIDE...TO THE LWR 70S OVER CNTRL WI. && .AVIATION...FOR 18Z TAF ISSUANCE ISSUED AT 104 PM CDT SUN MAY 3 2015 CONDITIONS WERE VFR ACROSS THE AREA AT MIDDAY AS A COLD FRONT WAS JUST ENTERING THE NORTHWEST CORNER OF WISCONSIN. CONFIDENCE HAS WANED WITH REGARD TO FORECAST OF CONVECTION ACROSS THE AREA THIS AFTERNOON INTO MONDAY MORNING. ONLY MADE MINOR ADJUSTMENTS TO TIMING FROM THE PREVIOUS FORECAST FOR NOW. THE MOST UNSTABLE CONDITIONS APPEARED TO BE ACROSS NORTH CENTRAL WISCONSIN WHERE MUCAPE VALUES WERE 500+ J/KG WITH LITTLE TO NO CIN THERE...BUT NO CONVECTION WAS YET EVIDENT IN THAT AREA. SHOWERS AND ISOLATED THUNDERSTORMS WERE CONFINED TO MINNESOTA AND EASTERN LAKE SUPERIOR AT 1745Z. MOST OF THE 12Z MODELS SHOWED QPF WITH THE FRONT GREATLY EXPANDING DURING THE AFTERNOON TO COVER THE ENTIRE AREA. A QUICK LOOK AT THE 16Z HRRR INDICATED ISOLATED-SCATTERED LIGHT QPF UNTIL A MORE SOLID AREA OF PRECIPITATION REACHES NORTH CENTRAL WISCONSIN. THIS LOOKS LIKE ITS ON TRACK...AT LEAST RIGHT NOW...SO MAINLY VFR AND DRY THE REST OF THE DAY IF IT REMAINS ON TRACK. CANNOT RULE OUT CONVECTIVE DEVELOPMENT WITH SPC DAY 1 SEVERE OUTLOOK INCLUDING MUCH OF THE AREA IN A SLIGHT RISK FOR SEVERE...WITH POSSIBLE DAMAGING WINDS AND LARGE HAIL THIS AFTERNOON AND TONIGHT. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....TDH LONG TERM......KALLAS AVIATION.......MG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1224 PM CDT SUN MAY 3 2015 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 321 AM CDT SUN MAY 3 2015 REGIONAL RADARS THIS MORNING SHOWING SOME CONVECTIVE ACTIVITY OVER CENTRAL AND WESTERN IOWA. THIS IS OCCURRING ON THE NOSE OF THE LOW LEVEL JET AND AHEAD OF A SHORT WAVE TROUGH MOVING ACROSS NORTHERN NEBRASKA. THE 03.03Z RAP INDICATES THIS WAVE WILL CONTINUE TO TRACK EASTWARD ACROSS NORTHERN IOWA THROUGH THE MORNING WITH THE LOW LEVEL JET VEERING TO THE EAST TO REMAIN AHEAD OF THE WAVE. THE RAP...03.04Z HRRR AND THE 03.00Z HI-RES ARW AND NMM ALL SUGGEST THERE IS A CHANCE THAT SOME OF THE ACTIVITY WITH THIS WAVE COULD GET INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN AND HAVE ADDED IN A SMALL CHANCE FOR THIS THROUGH ABOUT THE MIDDLE OF THE MORNING. THE MAIN CONVECTIVE SHOW WILL COME LATE THIS AFTERNOON INTO THE EVENING. THE 03.00Z MODELS HAVE REMAIN FAIRLY CONSISTENT TAKING THE MAIN SHORT WAVE TROUGH...CURRENTLY OVER SASKATCHEWAN...ALMOST DUE EAST WITH A SLIGHT POSITIVE TILT AND THE PV ADVECTION IN THE 500-300 MB LAYER REMAINING NORTH OF THE AREA. AS THIS WAVE MOVES EAST...IT WILL PUSH A COLD FRONT INTO THE AREA LATE THIS AFTERNOON AND THEN ACROSS THE REGION TONIGHT. BUFKIT SOUNDINGS FROM THE 03.00Z NAM INDICATE A PRETTY DEEP MIXED LAYER...UP TO ABOUT 850 MB...AHEAD OF THE FRONT THAT COULD BRING DOWN SOME DRIER AIR AND KEEP THE DEW POINTS CAPPED IN THE MID 50S. WITH 925 MB TEMPERATURES RISING ABOUT 2 TO 3C OVER SATURDAY...EXPECT THE SURFACE TEMPERATURES TO BE WARMER THAN SATURDAY WITH MIDDLE 80S FOR MUCH OF THE AREA. THE COMBINATION OF THESE TEMPS AND DEW POINTS SHOULD YIELD ML CAPES AROUND 1500 J/KG OR SO ALONG AND AHEAD OF THE FRONT. THE FORECAST SOUNDINGS ALSO SHOW A WEAK CAP IN THE WARM SECTOR AHEAD OF THE FRONT AND WITH MINIMAL HEIGHT FALLS...IT WILL TAKE THE THERMODYNAMIC FORCING WITH THE FRONT TO BREAK THE CAP. THE FRONTOGENESIS WITH THE FRONT LOOKS TO BE MODERATE IN STRENGTH IN THE 1000-850 MB AND THEN WEAK FROM 850 MB UP THROUGH 500 MB. THIS SHOULD BE ENOUGH TO BREAK THE WEAK CAP AND ALLOW CONVECTION TO FORM ALONG THE FRONT. THERE IS GOOD CLUSTERING AMONG THE HI-RES MESO MODELS...THE 03.00Z NAM12 AND 03.00Z NESTED NAM THAT THE FRONT SHOULD START TO APPROACH LATE THIS AFTERNOON WITH THE CONVECTION FIRST IMPACTING THE NORTHERN PARTS OF THE AREA IN THE 21Z-24Z WINDOW AND THEN DEVELOPING SOUTHWEST ALONG THE FRONT VERY LATE IN THE AFTERNOON INTO THE EARLY EVENING. THIS ACTIVITY SHOULD REMAIN STRONG INTO THE MIDDLE OF THE EVENING BEFORE THE CAPE QUICKLY DWINDLES WITH JUST GENERAL CONVECTION EXPECTED FOR CENTRAL AND SOUTHWEST WISCONSIN. THE SEVERE THREAT IS STILL PRESENT FROM ABOUT 4 PM THROUGH 10 PM WITH LARGE HAIL LOOKING TO BE THE MAIN THREAT AS GOOD MID LEVEL LAPSE RATES SHOULD AID IN THE HAIL PRODUCTION. NOT EXPECTING THE HAIL TO BE OVERLY LARGE AS A GENERAL LACK OF SHEAR WILL KEEP THE UPDRAFT ROTATION SUBDUED. WHAT SHEAR THERE IS WILL BE IN THE 0-3KM LAYER AND IS EXPECTED TO BE ON THE ORDER OF 25 TO 30 KNOTS...WHICH SHOULD BE ENOUGH TO PRODUCE SOME WIND GUSTS BUT MAY NOT BE ENOUGH TO KEEP THE GUST FRONTS CLOSE TO THE STORMS. THE MODELS NOW SUGGEST THE FRONT MAY NOT PUSH AS FAR SOUTH AS PREVIOUSLY INDICATED BEFORE STALLING OUT MONDAY. THE GENERAL MODEL CONSENSUS NOW SHOWS THE FRONT STALLING OVER SOUTHERN IOWA INSTEAD OF NORTHERN MISSOURI. THIS CLOSER PROXIMITY TO THE AREA COULD ALLOW SOME OF THE SHOWERS AND STORMS EXPECTED TO OCCUR NORTH OF THE FRONT TO CONTINUE OVER NORTHEAST IOWA INTO SOUTHWEST WISCONSIN MONDAY AFTERNOON AND EVENING. THE UPPER LEVEL PATTERN WILL START TO SHIFT TO MORE OF A SOUTHWEST FLOW AND BEGIN TO PUSH THE FRONT BACK TO THE NORTH LATE MONDAY NIGHT RESULTING IN A NORTHWARD EXPANSION OF THE RAIN CHANCES OVER ALL OF SOUTHEAST MINNESOTA AND MUCH OF WESTERN AND CENTRAL WISCONSIN. MOST OF THE AREA WILL THEN HAVE A CHANCE FOR RAIN TUESDAY AS THE FRONT MOVES BACK INTO THE AREA AND COULD POSSIBLY BE ACCOMPANIED BY A SHORT WAVE TROUGH ALOFT IN THE SOUTHWEST FLOW. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 321 AM CDT SUN MAY 3 2015 THE SOUTHWEST FLOW ALOFT LOOKS TO CONTINUE THROUGH THE PERIOD AS THE MAIN RIDGE REMAINS OVER THE EASTERN CONUS AND A LARGE UPPER LEVEL LOW SINKS SLOWLY SOUTH OVER THE WESTERN CONUS. WITH THIS FLOW PATTERN...SEVERAL PIECES OF ENERGY ARE EXPECTED TO COME OUT AND ACROSS THE UPPER MIDWEST. IT LOOKS AS IF IT WILL TAKE UNTIL SOMETIME WEDNESDAY OR WEDNESDAY NIGHT FOR THE RETREATING FRONT TO GET NORTH OF THE AREA. ONCE THIS HAPPENS...A COLD FRONT AND SURFACE LOW PRESSURE WILL START TO APPROACH FROM THE WEST WITH WHAT SHOULD BE A STRONGER SHORT WAVE TROUGH ALOFT. THIS FRONT WILL THEN MOVE ACROSS THE AREA IN THE END OF THE WORK WEEK WITH IT POSSIBLY BECOME STALLED OUT JUST TO THE SOUTH OF THE AREA INTO THE START OF THE WEEKEND. WITH THIS MESSY PATTERN...WILL CARRY RAIN CHANCES EACH DAY...ALTHOUGH WOULD NOT BE SURPRISED TO SEE A DRY PERIOD OR TWO...ESPECIALLY ONCE THE RETURNING FRONT GETS PAST THE AREA. HOWEVER...CONFIDENCE ON THIS IS TOO LOW TO WORK INTO THE FORECAST AT THIS TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1224 PM CDT SUN MAY 3 2015 VFR CONDITIONS EXPECTED THROUGH THIS AFTERNOON BEFORE A COLD FRONT ENTERS THE AREA EARLY THIS EVENING. EXPECTING A LINE OF THUNDERSTORMS TO ACCOMPANY THE FRONT...MAKING PASSAGE THROUGH KRST IN THE 23Z-03Z TIME FRAME...AND IN THE 01Z-05Z TIME FRAME AT KLSE. EXPECT DETERIORATING CONDITIONS WITH THE SHRA/TS ACTIVITY WITH CIGS/VSBY TEMPORARILY DIPPING INTO THE MVFR/IFR RANGE. THERE REMAINS THE POSSIBILITY THAT A FEW OF THE STORMS WILL BE CAPABLE OF PRODUCING STRONG GUSTY WINDS IN EXCESS OF 50KT AND HAIL TO THE SIZE OF QUARTERS. LOOK FOR THE FRONT AND SHRA/TS ACTIVITY TO CLEAR SOUTHEAST OF THE AREA IN THE 07-09Z TIME FRAME WITH A RETURN TO VFR CONDITIONS. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...04 LONG TERM...04 AVIATION...DAS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1213 PM MDT SUN MAY 3 2015 .UPDATE... ISSUED AT 1156 AM MDT SUN MAY 3 2015 CLOUDS ARE ALREADY STARTING TO INCREASE ACROSS MUCH OF THE AREA PER RECENT WATER VAPOR SATELLITE IMAGERY. POTENTIAL FOR SHOWERS AND THUNDERSTORMS LIKELY TO INCREASE CONSIDERABLY OVER THE NEXT FEW HOURS...ESPECIALLY ALONG/EAST OF THE LARAMIE RANGE. A WEAK SURFACE BOUNDARY WAS EVIDENT NORTHEAST OF CHEYENNE ON THE 18Z RADAR LOOP. AS THIS FEATURE SHIFTS SOUTHWEST...HIGH-RES MODELS TURN LLVL WINDS NORTHEAST AND UPSLOPE BY 18-19Z. THIS IS ALREADY REFLECTED IN SURFACE OBS OVER WESTERN NE. THE LAST COUPLE RUNS OF THE HRRR HAVE BEEN CONSISTENT WITH SHOWERS/TSTMS BECOMING FAIRLY WIDESPREAD AFTER 21Z OVER FAR SOUTHEAST WY...SO DECIDED TO BUMP POPS UP TO CATEGORICAL. ONLY OTHER CHANGE WAS TO INCREASE HIGHS A FEW DEGREES OVER THE PLAINS. WE ARE ALREADY 67F IN CHEYENNE AT NOON. ANOTHER DEGREE OR TWO OF WARMING IS POSSIBLE BEFORE CLOUDS AND PCPN HELP TO COOL THINGS DOWN. && .SHORT TERM...(TODAY THROUGH TUESDAY NIGHT) ISSUED AT 300 AM MDT SUN MAY 3 2015 STARTING OFF THIS MORNING...SURFACE ANALYSIS SHOWING A FRONTAL BOUNDARY LAYING WEST TO EAST ACROSS NORTHERN WYOMING...VERY SLOWLY MOVING SOUTH THIS MORNING. LOOKS TO LAY ALONG THE LARAMIE RANGE BY 18Z OR SO TODAY WITH NORTHEASTERLY WINDS BEHIND THE FRONT FOR AREAS EAST OF THE LARAMIE RANGE. MEANWHILE...THE UPPER LEVEL LOW THAT HAS BEEN SENDING US PIECES OF ENERGY THE PAST COUPLE DAYS CONTINUES OVER THE DESERT SOUTHWEST. BEST FOCUS FOR SHOWERS AND THUNDERSTORMS TODAY LOOKS TO BE WEST AND SOUTH OF THIS FRONT...BASICALLY ALONG AND WEST OF THE LARAMIE RANGE. BUT IT AL DEPENDS ON WHERE THIS FRONT ULTIMATELY ENDS UP BY EARLY AFTERNOON. SHOULD IT HAPPEN TO TAKE A LITTLE LONGER TO GET TO THE LARAMIE RANGE...SHOWERS AND STORMS COULD BE FURTHER EAST. A LITTLE MORE UNSTABLE TODAY OVER YESTERDAY WITH NAM SHOWING A POCKET OF 850MB CAPE AROUND 1000 J/KG NEAR LARAMIE OVER TO SARATOGA AND 700MB CAPES AROUND 600 J/KG. LIFTED INDICES NEAR -4C...SO DO BELIEVE THE STRONGEST STORMS WILL BE IN THIS AREA. LOCATIONS BEHIND THE FRONT WILL MOST LIKELY EXPERIENCE COOLER TEMPERATURES IN THE NORTHEAST FLOW...SO DID NOT STRAY TOO MUCH FROM THE LOW CHANCE POPS WE HAD GOING EAST OF I-25. DID INCREASE POPS THOUGH OUT WEST AS MODELS ARE IN GREAT AGREEMENT WITH THE LARAMIE RANGE...CARBON AND ALBANY COUNTIES SEEING DECENT RAINFALL THIS AFTERNOON. SHOWERS AND THUNDERSTORMS COULD LAST INTO THE LATE EVENING HOURS TONIGHT WITH THE FRONTAL BOUNDARY IN THE AREA AND FAIRLY GOOD UPSLOPING WINDS. SOME DIFFERENCES IN GFS AND ECMWF ON WHAT IS GOING TO HAPPEN MONDAY. BOTH ARE SHOWING SOME ENERGY MOVING NORTH FORM THE DESERT SOUTHWEST TO INTERACT WITH THE STALLED FRONTAL BOUNDARY. GFS KEEPS HIGHER POPS WEST...WHILE ECMWF SHOWS THE SOUTH LARAMIE RANGE AND POINTS SOUTH SEEING MOST OF THE POPS. WENT MORE WITH THE ECMWF/NAM SOLUTION WITH THE HIGHER POPS ACROSS THE SOUTH AND EAST. .LONG TERM...(WEDNESDAY THROUGH SATURDAY) ISSUED AT 300 AM MDT SUN MAY 3 2015 THE MODELS ARE STILL SHOWING A RATHER UNSETTLED EXTENDED PERIOD. ON WED THE SHORTWAVE TROUGH WILL BE LOCATED OVER CENTRAL NEBRASKA. GOOD LLVL MOISTURE IS INDICATED BY THE GFS WITH DEWPOINTS IN THE MID 40S TO LOW 50S ACROSS THE PLAINS AND PW VALUES ARE QUITE HIGH FOR EARLY MAY (0.75-1.0 INCHES). WITH MORE SUNSHINE ON WED COMPARED TO PREVIOUS DAYS...THERE WILL BE BETTER INSTABILITY. SO SCATTERED TO NUMEROUS SHOWERS AND TSTMS WILL DEVELOP BY WED AFTN...SOME WITH HEAVY RAIN. WHILE THE MODELS YESTERDAY WERE SHOWING A BRIEF BREAK IN THE PRECIP ON THURS...THIS IS REALLY NO LONGER THE CASE. AN UPPER LOW WILL BE CUT OFF ACROSS NORTHERN CALIFORNIA WITH EAST TO SOUTHEAST WINDS ACROSS THE CWA. THE GFS INDICATES ANOTHER AFTN OF DECENT CAPE (600-800 J/KG) SO DID RAISE POPS SOME INTO THE 30-40 PERCENT RANGE BY THURS EVENING. IT WILL LIKELY BECOME EVEN WETTER AS WE HEAD INTO FRI. THE UPPER LOW MOVES EASTWARD INTO THE GREAT BASIN ON FRI WITH UPPER LEVEL DIFFLUENCE INCREASING ACROSS SOUTHEAST WY. THERE IS ALSO GOOD LLVL UPSLOPE WITH A SFC HIGH OVER THE NORTHERN PLAINS...SO THE POTENTIAL EXISTS FOR SOME PRETTY HIGH RAINFALL AMOUNTS FROM FRI AFTN INTO SAT. BOTH THE GFS AND ECMWF SHOW WIDESPREAD QPF AMOUNTS OF 0.5-1.5 INCHES. WILL ALSO HAVE TO MONITOR THE POTENTIAL FOR SOME STRONG TO SVR STORMS AS THE EVENT DRAWS CLOSER...ALTHOUGH AT THIS TIME THE THREAT LOOKS MARGINAL WITH LIMITED INSTABILITY (MORE OF A STRATIFORM EVENT WITH EMBEDDED CONVECTIVE CELLS). && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1213 PM MDT SUN MAY 3 2015 CONCERNS ARE TWO-FOLD FOR THIS TAF CYCLE. THE INITIAL CONCERN WILL BE DEVELOPING CONVECTION NR KRWL AND KLAR AND PROBABLY GETTING INTO KCYS AFTER 20Z. FAVORED VCTS AT ALL THESE SITES UNTIL INDIVIDUAL CELLS CAN BE IDENTIFIED AND TIMED. PANHANDLE SITES WILL SEE LESS OF A CHANCE TO SEE THIS THUNDERSTORM ACTIVITY...ALTHOUGH KBFF MAY GET INTO IT AFTER 22Z. LATEST MODELS SUGGEST THIS ACTIVITY WILL LINGER INTO THE OVERNIGHT AND MORNING HOURS AS WELL AND EXPECT AVIATION CONDITIONS TO WORSEN AFTER 03-06Z AS WINDS TURN UPSLOPE FLOPPING AROUND TO THE SOUTHEAST. THIS IS A FAVORABLE DIRECTION FOR THE DEVELOPMENT OF LOW STRATUS/FG. ALSO EXPECT ANOTHER BAND OF SHOWERS TO LIFT NORTH ACROSS PRIMARILY PANHANDLE SITES AFTER 06Z. ANY STRATUS OR FOG THAT DOES EXIST WILL LIKELY LIFT IF THESE SHOWERS MATERIALIZE. FOR NOW HAVE TRENDED CONDITIONS DOWNWARD AFTER 06Z TO ACCOUNT FOR THIS ACTIVITY. && .FIRE WEATHER... ISSUED AT 300 AM MDT SUN MAY 3 2015 DAILY CHANCES FOR WETTING RAINS FOR MOST LOCATIONS AS A COLD FRONT MOVE SOUTH OUT OF MONTANA AND STALLS NEAR THE LARAMIE RANGE. THIS FRONT WILL INTERACT WITH ENERGY FROM A DISTURBANCE OVER THE FOUR CORNERS AREA AND WILL FOCUS SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST WYOMING. COOLER TEMPERATURES AND WETTING RAINS WILL AID IN ONGOING GREENUP OF FUELS...SO NO FIRE WEATHER CONCERNS ARE ANTICIPATED THROUGH MUCH OF THE UPCOMING WEEK. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...NONE. NE...NONE. && $$ UPDATE...CLH SHORT TERM...GCC LONG TERM...ZF AVIATION...CAH FIRE WEATHER...GCC