Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/06/13


AREA FORECAST DISCUSSION
NWS PUEBLO CO
1113 PM MDT THU OCT 3 2013 .UPDATE... ISSUED AT 1107 PM MDT THU OCT 3 2013 ADDED FOG TO PARTS OF THE PLAINS TONIGHT...MAINLY ALONG AND NORTH OF THE ARKANSAS RIVER. ALSO...LOADED FRESH OBSERVATIONS INTO THE FRONT END OF THE FORECAST GRIDS. UPDATE ISSUED AT 603 PM MDT THU OCT 3 2013 LOADED CURRENT OBSERVATIONS INTO FRONT END OF FORECAST GRIDS AND BLENDED INTO REST OF FORECAST. NO OTHER CHANGES AT THIS TIME. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 240 PM MDT THU OCT 3 2013 CURRENTLY... SFC BOUNDARY EXTENDS FROM NEAR CANON CITY...SOUTHEASTWARD TOWARDS KSPD. BOUNDARY BEST DEFINED BY DWPTS AS S OF BOUNDARY DWPTS WERE IN THE 20S WHILE N OF THE BOUNDARY DWPTS WERE IN THE U30S/40S. LOTS OF LOW CLOUDS WERE NOTED OVER FAR NE CO/NW KS. CLOUDS WERE INCREASING OVER THE C MTNS. KGJT 88D NOTED SHOWERS WERE INCREASING OVER NW CO INTO E UTAH. ON THE LARGE SCALE...A BROAD 50 MB LOW WAS LOCATED OVER IDAHO AND WAS DROPPING EAST-SOUTHEAST. REST OF TODAY INTO TONIGHT... MAIN CONCERN TONIGHT WILL BE OVER THE C MTNS. THIS REGION WILL LIKELY SEE PRECIP INCREASING EARLY THIS EVENING AND THIS PRECIP WILL INTENSIFY AS THE EVENING PROGRESSES. WITH STRONG FORCING MOVING ACROSS THE REGION AND STRONG UPSLOPE OVER THE CONTDVD...SNOW WILL BECOME HEAVY FOR A PD OF TIME TONIGHT. SEVERAL INCHES OF SNOW WILL BE LIKELY. THE NEXT CONCERN IS LOW CLOUDS OVER THE PLAINS. SFC FLOW WILL LIKELY NOT CHANGE TOO MUCH FROM CURRENT REGIME. HRRR SHOWS HI RH AT SFC MOVING BACK TOWARDS THE MTNS WHILE OTHER GUIDANCE HAS QUITE A BIT OF DRY AIR JUST ABOVE THE SFC....AND THESE GUIDANCE PRODUCTS KEEP THE PLAINS CLEAR. WILL LIKELY WAIT TIL THE LAST MINUTE TO LOOK AT LATEST GUIDANCE TO DECIDE IF LOW CLOUDS WILL BE NEEDED OVER THE PLAINS. BY LATE TONIGHT...FORCING WILL BE MOVING EASTWARD AND SHOWER MAY START TO AFFECT THE PIKES PEAK REGION. PRECIP WILL BE SNOW AT HIGHER ELEVATIONS WITH RAIN SHOWERS AT LOWER ELEVATIONS EXCEPT FOR AREAS DISCUSSED ABOVE...THE REST OF THE REGION WILL REMAIN DRY. TOMORROW... STRONG COLD FRONT WILL BLAST DOWN THE PLAINS. FRONT WILL BE UP ALONG THE PALMER DIVIDE AT SUNRISE AND WILL QUICKLY BLAST SOUTHEAST DURING THE REST OF THE MORNING. WINDS WILL PICK UP AND BECOME GUSTY FROM THE NORTHWEST AS THE MORNING PROGRESSES. I ANTICIPATE WINDS WILL BE IN THE G40 TO 45 MPH RANGE...MAINLY EAST OF A LINE FROM E EL PASO COUNTY TO EASTERN LAS ANIMAS COUNTY. WINDS WILL ALSO BE GUSTY ELSEWHERE....ESPECIALLY OVER THE MTNS. TEMPERATURES TOMORROW WILL NOT RISE TOO MUCH...IF AT ALL. TEMPS IN THE 80S TODAY WILL ONLY REACH INTO THE 40S AND 50S TOMORROW...WITH SOME 60S POSSIBLE EARLY ACROSS THE FAR SE PLAINS. THE WARMEST TEMPS WILL OCCUR MAINLY IN THE MORNING HOURS. SHOWERS WILL CONTINUE ACROSS THE C MTNS AND SW MTNS TOMORROW...AND POSSIBLY ACROSS THE HIGHER ELEVATIONS OF THE S MTNS AND PALMER DVD. SHOWERS OVER THE REGION WILL BE ENHANCED BY A SECONDARY PIECE OF ENERGY WRAPPING AROUND THE UPPER LOW COMING ACROSS THE REGION. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 240 PM MDT THU OCT 3 2013 FRIDAY NIGHT...NAM...GFS AND EC MODELS PLACE THE UPPER LOW OVER THE NE CORNER OF THE STATE AT 00Z SAT...AND THEN QUICKLY MOVING THE SYSTEM OFF TO THE E-NE THROUGH THE NIGHT. STRONG GUSTY NORTH WINDS ARE FORECAST TO CONTINUE THROUGH THE EARLY EVENING FOR THE E PLAINS AS WRAPAROUND FROM THE DEPARTING SYSTEM DRAWS A STRONG COLD POOL DOWN INTO THE CWA. MODELS ARE NOT SHOWING A LOT OF PCPN WITH THIS SYSTEM...SO THE MAIN STORY WILL BE INITIALLY THE STRONG WINDS BUT THEN THE SIGNIFICANTLY COLDER AIR OVERNIGHT INTO EARLY SAT MORNING. THIS PROMPTED A FREEZE WATCH ISSUANCE EARLIER TODAY...IN EFFECT FROM MIDNIGHT FRI THROUGH 9 AM SAT MORN...FOR THE I-25 CORRIDOR AS WELL AS CROWLEY AND OTERO COUNTIES. THE MAIN AREA THOUGH MOST LIKELY WILL BE ALONG THE I-25 CORRIDOR AND NEAR THE MTS WHERE THE COLD AIR WILL POOL AND DROP MIN TEMPS DOWN INTO THE MID TO UPPER 20S. SATURDAY THROUGH TUESDAY...THE UPPER SYSTEM QUICKLY EXITS TO THE E-NE SAT MORNING...THEN MODELS INDICATE THAT AN UPPER RIDGE OF HIGH PRESSURE WILL SLOWLY SLIDE EASTWARD ACROSS THE WESTERN HALF OF THE COUNTRY THROUGH TUESDAY. LOOK FOR DRY CONDITIONS AND GRADUALLY WARMING TEMPS OVER THE WEEKEND AND INTO THE BEGINNING OF THE NEXT WORK WEEK. EXPECT 50S AND 60S ON SAT...60S AND 70S SUN...THEN 70S TO AROUND 80 F BOTH MON AND TUE. THERE IS THE OUTSIDE CHANCE THAT SAT NIGHT/SUN MORN WILL SEE ANOTHER FREEZE FOR THE EASTERN PLAINS DUE TO CLEAR SKIES AND LINGERING COLD AIR. WEDNESDAY AND THURSDAY...EC AND GFS MODELS INDICATE THAT ANOTHER UPPER TROUGH WILL DROP DOWN ACROSS THE GREAT BASIN BY MID-WEEK...BRINGING WARM AND DRY CONDITIONS DUE TO SW FLOW ON WED. BY WED NIGHT SHOWERS WILL RETURN TO THE CONTDVD...WITH COOLER TEMPS AND A BETTER CHANCE FOR PCPN FOR ALL OF THE CWA ON THU. MOORE && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1107 PM MDT THU OCT 3 2013 MAIN CONCERN AT ALL 3 TAF SITES WILL BE GUSTY WINDS NEXT 24H. A STRONG COLD FRONT WILL CROSS KPUB AND KCOS TOMORROW MORNING AROUND SUNRISE AND GUSTY NORTHWEST WINDS WILL DEVELOP TOMORROW MORNING INTO TOMORROW AFTERNOON. NORTHWEST WINDS TO 15 TO 30+ KNTS WILL BE POSSIBLE. GUSTY SOUTHWEST WINDS WILL ALSO OCCUR AT KALS SHIFTING TO WNW LATER TOMORROW AFTERNOON. KALS SHOULD SEE VFR THROUGH THE PD. FOR KCOS AND KPUB...THERE IS A LOW CHANCE THAT WE MAY SEE SOME LOW CIGS LATER TONIGHT. SOME MEMBERS OF THE SREF ALONG WITH HRRR GUIDANCE SHOW SOME LOW CIGS POSSIBLE...HOWEVER THE LARGE MAJORITY OF THE GUIDANCE KEEPS LOW CIGS AWAY FROM KPUB AND KALS. THERE MAY BE A FEW SHOWERS AT KCOS TOMORROW...BUT BRUNT OF PRECIP SHOULD REMAIN NORTH ALONG THE PALMER DVD. && .PUB WATCHES/WARNINGS/ADVISORIES... FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING FOR COZ083>089-093. && $$ UPDATE...LW SHORT TERM...HODANISH LONG TERM...MOORE AVIATION...LW
AREA FORECAST DISCUSSION
NWS ALBANY NY
943 AM EDT FRI OCT 4 2013 .SYNOPSIS... A WARM FRONT WILL LIFT SLOWLY NORTHWARD FROM THE LOWER GREAT LAKES REGION AND THE MID ATLANTIC STATES. THIS FRONT WILL PRODUCE SOME SHOWERS ALONG WITH A FEW RUMBLES OF THUNDER THROUGH TODAY ACROSS THE REGION. INCREASING HUMIDITY LEVELS...AND THE THREAT FOR ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH THE WEEKEND WITH THIS BOUNDARY IN THE VICINITY OF THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM...SHOWERS HAVE BECOME NUMEROUS FROM THE EASTERN MOHAWK AND SCHIHARIE VALLEYS TO SOUTHERN VERMONT AND BERKSHIRE COUNTY. HAVE RAISED POPS THERE TO LIKELY FOR THE REST OF THE MORNING...WHILE KEEPING CHANCE POPS IN ALL AREAS DURING THE AFTERNOON. REST OF THE PREVIOUS FORECAST PACKAGE IS GENERALLY UNCHANGED. PREV DISC... SURFACE ANALYSIS HAS A WARM FRONT DRAPED ACROSS WESTERN NY INTO CENTRAL PA AND OFF THE MID ATLANTIC COAST. IN THE UPPER LEVELS...H2O VAPOR LOOP SHOWS A WEAK SHORT WAVE APPROACHING WESTERN NY WHERE RUC13 ISENTROPIC ANALYSIS ON THE 300-305K SURFACE REVEALS BROAD LIFT. REGIONAL RADARS CONFIRM THIS WITH SHOWERS AND SOME THUNDERSTORMS /PER THE NLDN/ ACROSS THE MOHAWK VALLEY WITH MORE CONCENTRATION OF ACTIVITY ACROSS WESTERN NY. TRENDS FOR THE DAYLIGHT HOURS ARE FOR ADDITIONAL SHOWERS AND SOME THUNDERSTORMS TO MOVE ACROSS THE REGION WITH THE BETTER CONCENTRATION ALONG THE I90 CORRIDOR WHERE THE WARM FRONT IS FORECAST TO BE PLACED WITH ADDITIONAL MID LEVEL INSTABILITY PER THE SHOWALTER VALUES AROUND 0C. THIS TOO IS SUGGESTED BY THE HRRR EXPERIENTIAL REFLECTIVITY FORECASTS. WITH CONSIDERABLE CLOUD COVER EXPECTED...HAVE SHADED ON THE COOLER SIDE OF THE GUIDANCE. THE AFOREMENTIONED SHORT WAVE IS FORECAST TO EXIT OUR REGION BY THIS EVENING. SOME RESIDUAL SHOWERS AND PERHAPS A RUMBLE OF THUNDER ARE EXPECTED THROUGH EARLY THIS EVENING...THEN ISOLATED ACTIVITY FOR THE REMAINDER OF THE OVERNIGHT PERIOD. WARM FRONT WILL BE IN THE VICINITY OF THE REGION SO CLOUD COVER WILL LIKELY BE IN PLACE AND POCKETS OF DRIZZLE AS THE LOWER LEVELS ARE EXPECTED TO BE QUITE MOIST PER TH BUFR SOUNDINGS. LOW LEVEL FLOW SLOWLY INCREASES FROM THE NORTH WHICH WILL PLAY HAVOC ON TEMPERATURES TONIGHT. GUIDANCE NUMBERS ARE RATHER CLOSE AS WE UTILIZED A BLENDED APPROACH. HOWEVER...IF THE DRAINAGE IS A BIT STRONGER...THEN TEMPERATURES COULD BE A LITTLE COOLER. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... THE CENTRAL PLAINS STORM IS FORECAST TO BE QUITE MATURE AT THIS TIME FRAME. MEANWHILE...THE WARM FRONT REMAINS IN THE VICINITY WITH SOME TENDENCY TO SLIP A LITTLE FURTHER SOUTH AS HIGH PRESSURE ACROSS SOUTHERN CANADA ATTEMPTS TO NOSE SOUTHWARD ACROSS OUR REGION SATURDAY. EITHER WAY...CONSIDERABLE CLOUDINESS IS EXPECTED AS LOWER LEVELS REMAIN QUITE MOIST ALONG WITH A SLIGHT CHANCE FOR A SHOWER. WE WILL SHADE ON THE COOLER SIDE OF THE GUIDANCE ENVELOPE AS THE LOW LEVEL NORTHERLY FLOW AND CLOUD COVER SHOULD KEEP TEMPS INTO THE 60S FOR MOST LOCATIONS WITH LOWER 70S FOR THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD COUNTY. THE WARM FRONT WILL ATTEMPT TO SLOWLY LIFT NORTHWARD SATURDAY NIGHT AND THROUGH SUNDAY. MOISTURE TRANSPORT AND ASSOCIATED LIFT INCREASES TO OUR WEST AND NORTH WHERE WE WILL PLACE THE HIGHER POPS. TEMPERATURES WILL BE RATHER STAGNATE AS SUGGESTED BY THE GFS-MOS WITH NOT MUCH RANGE EXPECTED. IT DOES SEEM WE WILL BECOME ENTRENCHED INTO THE WARM SECTOR DURING SUNDAY BUT THE COMBINATION OF MARINE AIR INFLUENCE AND CLOUD COVER THOSE H850 TEMPS INTO THE LOW-MID TEENS WILL NOT BE FULLY REALIZED. THUS WE HAVE LOWERED HIGH TEMPERATURES A FEW DEGREES. AS FOR PRECIP CHANCES...MAINLY TO OUR WEST AND NORTH ONCE AGAIN AND AS THIS FRONT LIFTS FURTHER NORTH...SO WILL THE DECREASING TENDENCY FOR SHOWERS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE EXTENDED PERIOD WILL START OFF RATHER ACTIVE...BUT ANOTHER EXTENDED PERIOD OF DRY AND MILD WEATHER WILL FOLLOW. OUR REGION WILL BE IN A WARM SECTOR OF A FRONTAL SYSTEM ON SUNDAY NIGHT. WITH PLENTY OF MOISTURE IN PLACE...THERE WILL BE A CHC FOR RAIN SHOWERS ACROSS THE ENTIRE REGION. THE BEST CHC FOR RAIN SHOWERS WILL BE ACROSS FAR NORTHWESTERN PARTS OF THE REGION...ESP TOWARDS SUNRISE MONDAY. WITH A SOUTHERLY FLOW IN PLACE...IT WILL BE MILD AND MUGGY...WITH MIN TEMPS IN THE MID 50S TO LOW 60S. A STRONG COLD FRONT WILL BE MOVING ACROSS THE REGION SOMETIME MONDAY INTO MONDAY EVENING. THE MODELS DON/T AGREE ON THE EXACT TIMING RIGHT NOW...WITH THE 00Z GFS A LITTLE FASTER THAN THE 00Z ECMWF. BY THIS POINT....NHC SHOWS THAT TC KAREN BE IN THE PROCESS OF TRANSITIONING FROM A TROPICAL ENTITY...AND THE REMAINS LOOK TO BE ABSORBED ALONG THE FRONTAL BOUNDARY WELL TO OUR SOUTH. STILL...A STRONG LOW LEVEL JET OF 50-60 KTS WILL TRANSPORT PLENTY OF MOISTURE UP ALONG THE FRONT FROM THE GULF OF MEXICO...WITH PWAT VALUES EXCEEDING 1.50 INCHES ACROSS OUR REGION. WITH THE STRONG SFC FORCING...A BAND OF LOCALLY HEAVY RAIN SHOWERS WILL BE POSSIBLE JUST AHEAD AND ALONG THE FRONTAL BOUNDARY. ALONG WITH LIKELY POPS FOR RAIN SHOWERS...WE WILL INCLUDE A SLIGHT CHC OF THUNDER...BUT WIDESPREAD THUNDER DOESN/T APPEAR LIKELY DUE TO MEAGER AMOUNTS OF INSTABILITY. IT WILL BE FAIRLY WARM ON MONDAY IN ADVANCE OF THE FRONTAL BOUNDARY WITH MID 60S TO MID 70S ACROSS THE REGION. MIN TEMPS WILL ON MONDAY NIGHT WILL BE COOLER THAN SUN NIGHT...BUT THE EXACT TIMING WILL DEPEND JUST HOW MUCH COOLS OFF. FOR NOW...WE ARE FORECASTING MIN TEMPS FROM THE LOW 40S IN THE DACKS TO THE MID 50S IN THE MID HUDSON VALLEY AND NW CT. WE WILL STILL ALLOW FOR A SHOWER ACROSS SOUTHERN AREAS TUESDAY MORNING IN CASE THE FRONT SLOWS...OTHERWISE THE COLD FRONT SHOULD HAVE PUSHED OFF TO OUR EAST BY TUESDAY...ALLOWING A DRIER AND SOMEWHAT COOLER AIR MASS TO MOVE INTO OUR REGION. IT WILL BE DRY FOR THE MID WEEK PERIOD /TUES AND WED/ WITH MAX TEMPS IN THE 60S...AND LOWS IN THE 40S /SOME 30S ACROSS THE ADIRONDACKS AND SRN GREEN MTNS/. THESE MAX TEMPS STILL LOOK A FEW DEGREES ABOVE NORMAL. BY LATE IN THE WEEK...STRONG RIDGING WILL REESTABLISH ITSELF ALONG THE EASTERN SEABOARD...AND EVEN MORE ABOVE NORMAL WARMTH WILL BE IN PLACE FOR THURS/FRI. IT WILL CONTINUE TO BE DRY...WITH DAYTIME TEMPS IN THE UPPER 60S TO MID 70S FOR VALLEY AREAS...AND MINS GENERALLY IN THE MID 40S TO LOW 50S. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... A WARM FRONT IS SITUATED SOUTH OF THE REGION IS SLOWLY MOVING NORTHWARD. OVC CIGS OF 4-6 KFT ARE IN PLACE ACROSS THE REGION. REGIONAL MOSAIC RADAR SHOWS SOME SHOWERS WEST OF THE REGION...AND THESE MAY AFFECT MAINLY THE NORTHERN SITES THROUGH THE MORNING HOURS. WILL INCLUDE A VCSH AT ALL SITES WITH A TEMPO FOR MVFR CIGS/VSBYS WITHIN RAIN SHOWERS FOR KALB/KGFL/KPSF. AT THIS POINT...WIDESPREAD IFR CONDITIONS ARE NOT ANTICIPATED TODAY. LIGHT AND VARIABLE WINDS ARE EXPECTED TODAY. FLYING CONDITIONS WILL GENERALLY BE VFR DURING THE AFTN HOURS FOR THE VALLEY TERMINALS...ALTHOUGH CIGS MAY REMAIN MVFR AT KPSF. WITH LOW LEVEL MOISTURE REMAINING HIGH TONIGHT...ALL SITES LOOK TO HAVE MVFR CIGS TONIGHT WITH MVFR BR POSSIBLE AT KPSF/KPOU AS WELL. ALTHOUGH NOT AS WIDESPREAD AS THIS MORNING...STILL CANNOT RULE OUT A SHOWER OR TWO THIS AFTERNOON INTO TONIGHT AS WELL. WINDS WILL BE NEARLY CALM TONIGHT. OUTLOOK... SATURDAY-SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SUNDAY-MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A WARM FRONT WILL LIFT SLOWLY NORTHWARD FROM THE LOWER GREAT LAKES REGION AND THE MID ATLANTIC STATES. THIS FRONT WILL PRODUCE SCATTERED SHOWERS ALONG WITH A FEW RUMBLES OF THUNDER THROUGH TODAY FROM THE MOHAWK VALLEY AND THE CAPITAL REGION SOUTH. INCREASING HUMIDITY LEVELS...AND THE THREAT FOR ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH THE WEEKEND WITH THE BOUNDARY IN THE VICINITY OF THE REGION. THE RH VALUES WILL FALL TO 50 TO 65 PERCENT THIS AFTERNOON...THEN RECOVER TO 80 TO 100 PERCENT BY SATURDAY MORNING. THE WINDS BECOME LIGHT TO CALM THIS MORNING AND SATURDAY NIGHT...THEN BE FROM THE EAST TO NORTHEAST AT 5 TO 10 MPH DURING THE DAYLIGHT HOURS TODAY. A COLD FRONT WILL BRING WIDESPREAD SHOWERS TO THE REGION LATE SUNDAY INTO EARLY NEXT WEEK. && .HYDROLOGY... NO WIDESPREAD PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE NEXT 5 DAYS. FLOWS CONTINUE AT NORMAL TO BELOW NORMAL LEVELS FOR EARLY OCTOBER. THE DRY WEATHER STRETCH OVER THE PAST 10 DAYS OR SO WILL BE COMING TO AN END AS A WARM FRONT APPROACHES ALONG WITH THE CHANCE FOR SHOWERS FOR THE REMAINDER OF THIS WEEK AND INTO THE WEEKEND. AT THIS TIME...QPF AMOUNTS RANGE FROM A TENTH OF AN INCH OVER THE NRN PORTIONS OF THE HSA TO A THIRD OF AN INCH OVER THE SRN THIRD FROM TONIGHT INTO SATURDAY MORNING. THERE IS SIGNIFICANT UNCERTAINTY IN THE GUIDANCE IN THE TIMING AND TRACK OF A STRONGER LOW PRESSURE SYSTEM AND ITS FRONTAL BOUNDARY FOR LATE IN THE WEEKEND AND EARLY NEXT WEEK. FURTHERMORE...WE CONTINUE TO MONITOR TRENDS ON THE TRACK OF TS KAREN IN THE GULF OF MEXICO FROM THE GUIDANCE FROM THE NATIONAL HURRICANE CENTER. THE AMOUNT OF RAINFALL VARIES GREATLY IN THE GUIDANCE AT THIS TIME FOR PORTIONS OF EXTREME SRN NY AND NEW ENGLAND EARLY IN THE WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...GJM/BGM NEAR TERM...GJM/BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
659 AM EDT FRI OCT 4 2013 .SYNOPSIS... A WARM FRONT WILL STALL JUST TO THE SOUTHWEST TODAY...LEADING TO SOME SHOWERS AND POSSIBLY EVEN AN ISOLATED THUNDERSTORM TO THE REGION. ANOTHER BRIEF PERIOD OF MOSTLY DRY WEATHER THEN RETURNS LATE TONIGHT INTO SATURDAY. THE FRONT BEGINS TO LIFT NORTH OF THE AREA AS A WARM FRONT SUNDAY YIELDING WARMER TEMPERATURES MONDAY ALONG WITH A BETTER CHANCE OF WIDESPREAD SHOWERS EARLY NEXT WEEK...AS A COLD FRONT SLOWLY MOVES ACROSS NEW ENGLAND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 7 AM UPDATE... SHOWERS ACROSS NY STATE CONTINUE TO MARCH EASTWARD INTO SOUTHERN VT AND NH AT 7 AM. THESE SHOWERS WERE ASSOCIATED WITH THE LEADING EDGE OF AN AIRMASS CHANGE ALOFT...WITH WARM AIR ADVECTING EASTWARD ON A MODEST MID LEVEL JET. SOME INSTABILITY ALOFT SO DECIDED TO LEAVE SLIGHT CHANCE OF AN ELEVATED TSTM TODAY ACROSS THE REGION. 06Z NAM AND GFS NOT CAPTURING THE SHOWER ACTIVITY VERY WELL. THE LATEST HRRR AND 00Z ECMWF DOING A MUCH BETTER JOB. THUS HAVE UPDATED HOURLY POPS TO BETTER REFLECT MOST RECENT RADAR TRENDS. OTHERWISE PREVIOUS FORECAST ON TRACK. ANY RAINFALL RECEIVED TODAY WILL BE NEEDED AS LAST MEASUREABLE RAINFALL OCCURRED SEP 22! PREVIOUS DISCUSSION BELOW. -------------------------------------------------------------- THE COMBINATION OF A SFC WARM FRONT STALLING TO THE SW AND A WEAK DISTURBANCE MOVING THROUGH ZONAL FLOW ALOFT WILL LEAD TO MORE UNSETTLED WX TODAY THAN WE HAVE SEEN OF LATE. LIFT IS RELATIVELY WEAK WITH EACH OF THESE FEATURES...BUT PRECIPITAL WATERS ARE EXPECTED TO REACH 1.5-1.75 INCHES. THEREFORE...EXPECTING SOME SHOWERS TO SLIDE INTO THE W EARLY TODAY...THEN CONTINUE ESE THROUGH THE DAY. AM ALREADY NOTING SOME WIDELY SCATTERED -SHRA ON KBGM/KENX RADARS...WHICH WILL BE THE FIRST OF THESE -SHRA. AM NOTING 40+ DBZ ON A FEW OF THESE -SHRA...WHICH CONFIRMS THE THREAT THAT INDIVIDUAL CELLS COULD ACTUALLY BE BRIEFLY HEAVY GIVEN THE HIGH MOISTURE CONTENT FOR EARLY OCT. ALSO...IN THE S AND W...AM NOTING SFC LI/S NEAR TO BELOW 0...WITH K VALUES 30+...SO AN ISOLATED RUMBLE OF THUNDER MAY ALSO ACCOMPANY THESE HEAVIER -SHRA LATE THIS MORNING AND INTO THE EVENING. THESE -SHRA WILL LIKELY BE HIT OR MISS...WITH SOME AREAS...PARTICULARLY TOWARD THE NE...POSSIBLY SEEING LITTLE TO NO PRECIP. THIS IS DUE TO A BUILDING SUBTROPICAL RIDGE OVER THE ERN CONUS...AND THE RESPONSE OF SFC RIDGING ACROSS SRN QUEBEC AND NRN NEW ENGLAND...WHICH WILL GRADUALLY SHUNT THE ATTENDANT SHORTWAVES TO THE S. GIVEN A FAIR AMOUNT OF EXPECTED CLOUD COVER...PARTICULARLY IN THE W INITIALLY...EXPECT TEMPERATURES TO REMAIN A BIT COOLER TODAY. HIGHS IN THE W /WHERE CLOUD COVER IS LIKELY TO LINGER FOR THE WHOLE DAY/ HIGHS WILL ONLY REACH INTO THE UPPER 60S...WHILE LOW TO MID 70S ARE POSSIBLE IN THE E WITH A BETTER CHANCE FOR SUNSHINE. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... TONIGHT... WEAK UPPER LVL DISTURBANCE WILL BE SLIDING ESE OF THE REGION WITH TIME...ALLOWING FOR MID LVL RIDGING AND ATTENDANT INVERTED SFC RIDGE FROM NRN NEW ENGLAND TO REGAIN CONTROL. THEREFORE...EXPECT THAT ANY -SHRA/T-STORMS PRODUCED BY THE WEAK INSTABILITY AND SHORTWAVE TO BE GRADUALLY WEAKENING AND SHIFTING ESE THEMSELVES AS DIURNAL HEAT IS LOST AND THE BEST LIFT MOVES OFFSHORE. WILL GRADUALLY BE LOWING POPS FROM N TO S WITH TIME. MAY BE THAT CONDITIONS ARE MOSTLY DRY BY THE MORNING HOURS AS DRY AIR BUILDS BACK INTO THE COLUMN AND THE UNSETTLED CONDITIONS DECOUPLE FROM THE WARM FRONT STALLED UPSTREAM. MIN TEMPERATURES ARE EXPECTED TO BE MILD THANKS TO CONTINUED CLOUD COVER AND HIGHER DWPTS FROM THE GRADUALLY DRYING AIRMASS. EXPECT MOST MINS IN THE LOW TO MID 50S. SAT... MID LVL RIDGE CONTINUES TO BUILD FED BY STRONG WARM ADVECTION AHEAD OF A STRONG CUTOFF APPROACHING THE GREAT LAKES. THIS ALLOWS THE SFC HIGH PRES TO THE N TO GAIN CONTROL THROUGH THE DAY. AM NOTING MORE STABLE AND DRIER SOUNDINGS ACROSS THE REGION WITH ONLY WEAK ISENTROPIC LIFT AHEAD OF THE WARM FRONT TO THE SW. THEREFORE...WILL SUGGEST ONLY SLIGHT CHANCE OR LOWER POPS THROUGH THE DAY WITH A FOCUS ON THE SRN HALF OF THE REGION...CLOSER TO THE FRONT ITSELF. IT IS VERY POSSIBLE THAT MANY LOCALES REMAIN DRY THROUGH THE DAY...AND THAT BREAKS OF SUN ARE POSSIBLE ESPECIALLY ACROSS THE N. THEREFORE...EXPECT SLIGHTLY WARMER HIGHS WITH H85 TEMPS AVERAGING +12C...IN THE LOW TO MID 70S. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... HIGHLIGHTS... * TEMPERATURES AT OR WARMER THAN NORMAL * UNSETTLED BUT NOT A WASHOUT SUNDAY * WIDESPREAD SHOWERS WITH LOCALLY HEAVY RAIN POSSIBLE MON/TUE SYNOPTIC OVERVIEW... A WARM FRONT WILL BE LIFTING NORTH THROUGH THE REGION SUNDAY AS ITS PARENT LOW EXITS THE GREAT LAKES INTO ONTARIO. THE ATTENDING COLD FRONT WILL BE PROGRESSIVE AND SWEEP ACROSS NEW ENGLAND SOMETIME MON/TUE. THE FRONT WILL MOVE OFFSHORE LATER TUE WITH CONFLUENT FLOW ALOFT AND HIGH PRES AT THE SURFACE BUILDING INTO NEW ENGLAND LATER TUE INTO WED/THU. THIS MAY LEAVE THE REMNANTS OF TS KAREN MEANDERING SOMEWHERE OVER THE SOUTHEAST STATES NEXT WEEK. MODELS/GUIDANCE... GOOD AGREEMENT ON THE OVERALL SYNOPTIC SCALE FLOW/FORECAST THEME. 00Z GFS/GEFS AND 12Z ECENS DISPLAY GOOD CLUSTERING ON POWERFUL CLOSED MID LEVEL LOW OVER THE GREAT LAKES SUN NIGHT...THEN DEAMPLIFYING AND BECOMING AN OPEN WAVE AS IT RACES ACROSS ONTARIO AND QUEBEC MON. THIS RESULTS IN A PROGRESSIVE COLD FRONT CROSSING NEW ENGLAND MON-TUE. THIS PROGRESSIVE NORTHERN STREAM SYSTEM RESULTS IN AN UNPHASED SOLUTION WITH REMNANTS OF TS KAREN BEING LEFT BEHIND ACROSS THE SOUTHEAST STATES EARLY NEXT WEEK. HOWEVER THE 00Z ECMWF REMAINS MORE AMPLIFIED WITH THE GREAT LAKES MID LEVEL LOW WHICH CAPTURES THE REMNANTS OF KAREN AND INGEST ITS MOISTURE PLUME INTO THE FRONTAL BOUNDARY CROSSING NEW ENGLAND MON/TUE. HOWEVER ITS SOLUTION TOO IS VERY PROGRESSIVE WITH ONLY A BRIEF PERIOD OF HEAVY RAIN/SHOWERS SOMETIME MON/TUE. HOWEVER THE 00Z GFS/GEFS AND 12Z ECENS ALL SUGGEST REMNANTS OF TS KAREN REMAINING WELL SOUTH OF NEW ENGLAND. EITHER WAY NONE OF THE MODEL GUIDANCE SUPPORTS A HIGH IMPACT/HEAVY RAINFALL EVENT FOR SOUTHERN NEW ENGLAND. SENSIBLE WEATHER... SAT NIGHT/SUNDAY...WARM FRONT LIFTS ACROSS AND NORTH OF THE REGION. DEEP LAYER MOISTURE AND LIFT ARE LACKING SO THINKING ANY SHOWER ACTIVITY WILL BE SPOTTY AND NOT WIDESPREAD. HENCE MANY HOURS OF DRY WEATHER. COOLER AS WARM SECTOR MAY NOT OVERSPREAD THE REGION UNTIL SUN NIGHT OR MON. MON/TUE...A PERIOD OF SHOWERS WITH LOCALLY HEAVY RAIN APPEARS LIKELY. DEPARTURE TIME OF SHOWERS STILL SOMEWHAT UNCERTAIN. MILD TO WARM WITH FROPA NOT TIL LATE TUE OR TUE NIGHT. WED/THU...UNCERTAINTY HERE BUT SOME MODEL CONSENSUS ON A DRYING TREND WITH HIGH PRES BUILDING OVER NEW ENGLAND AND SUPPRESSING REMNANTS OF TS KAREN WELL SOUTH OF NEW ENGLAND. IF THIS TREND CONTINUES NEXT SHIFT MAY NEED TO LOWER POPS HERE. COOLER BUT PROBABLY STILL NEAR OR SLIGHTLY WARMER THAN NORMAL. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE. 7 AM UPDATE... NO CHANGE FROM PREVIOUS FORECAST. EARLIER DISCUSSION BELOW. --------------------------------------------------------------- SOME SHOWERS POSSIBLE DURING THE DAY WITH A FOCUS ON WRN AND SRN PORTIONS OF THE AREA. AN ISOLATED THUNDERSTORM IS ALSO POSSIBLE THIS AFTERNOON/EVENING IN CT. MAINLY VFR IS EXPECTED TO PREVAIL THROUGH THE PERIOD. THE ONLY CAVEAT WILL BE THE POTENTIAL FOR SOME MVFR CIGS AND VSBYS WITH SOME OF THE -SHRA THIS AFTERNOON ALONG A PSF- BAF/BDL- PVD LINE THIS AFTERNOON AND EVENING. OTHERWISE...SOME BREAKS IN BOTH THE -SHRA AND CLOUDS OVERNIGHT INTO SATURDAY. KBOS TERMINAL...HIGH CONFIDENCE VFR. LIGHT WINDS SHIFT TO THE E WITH A SEABREEZE THEN REMAIN MOSTLY E. THIS MAY INTRODUCE SOME LOW CIGS LATE IN THE DAY/EVENING...BUT CONFIDENCE IS LOW. KBDL TERMINAL...MAINLY VFR...BUT SOME MVFR CIGS POSSIBLE THIS AFTERNOON. SCT SHOWERS THROUGH THE DAY TODAY. LOW PROB OF ISOLD TSTM FRI AFTERNOON. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... MODERATE CONFIDENCE. SAT NIGHT/SUN...VFR LIKELY WITH SPOTTY SHOWERS POSSIBLE. MON/TUE...A PERIOD OF MVFR/IFR POSSIBLE IN SHOWERS WITH AN APPROACHING COLD FRONT. && .MARINE... FORECASTER CONFIDENCE LEVELS... LOW...LESS THAN 30 PERCENT. MODERATE...30 TO 60 PERCENT. HIGH...GREATER THAN 60 PERCENT. SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE. EXPECT WINDS AND SEAS TO REMAIN BELOW SMALL CRAFT CRITERIA THROUGH SATURDAY. A FEW SHOWERS AND POSSIBLY EVEN A RUMBLE OF THUNDER MAY AFFECT THE SOUTHERN WATERS THIS AFTERNOON AFTERNOON AND TONIGHT WITH LOCAL VSBY RESTRICTIONS. OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY... SAT NIGHT/SUN...LIGHT SE WINDS WITH HIGH PRES OVER THE MARITIMES. SUN NIGHT/MON...INCREASING SSW WINDS WITH APPROACHING COLD FRONT. VSBY LIMITED IN SHOWERS AND FOG. MON NIGHT/TUE...COLD FRONTAL PASSAGE WITH REMNANTS OF TS KAREN LIKELY REMAINING WELL SOUTH OF NEW ENGLAND. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...NONE. && $$ SYNOPSIS...NOCERA/DOODY NEAR TERM...NOCERA/DOODY SHORT TERM...DOODY LONG TERM...NOCERA AVIATION...NOCERA/DOODY MARINE...NOCERA/DOODY
AREA FORECAST DISCUSSION
NWS ALBANY NY
617 AM EDT FRI OCT 4 2013 .SYNOPSIS... A WARM FRONT WILL LIFT SLOWLY NORTHWARD FROM THE LOWER GREAT LAKES REGION AND THE MID ATLANTIC STATES. THIS FRONT WILL PRODUCE SCATTERED SHOWERS ALONG WITH A FEW RUMBLES OF THUNDER THROUGH TODAY FROM THE MOHAWK VALLEY AND THE CAPITAL REGION SOUTH. INCREASING HUMIDITY LEVELS...AND THE THREAT FOR ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH THE WEEKEND WITH THE BOUNDARY IN THE VICINITY OF THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 6 AM EDT...BANDS OF SHOWERS/STORMS HAS DEVELOPED ALONG AND JUST NORTH OF THE I90 CORRIDOR PER THE LATEST RADAR SCANS THIS MORNING. THE THETA-E ADVECTION WAS A TOUCH STRONGER AND FURTHER NORTH PER THE HOURLY RUC13 ANALYSIS AND HAVE ADJUSTED THE FORECAST/GRIDS ACCORDINGLY. OTHERWISE...FORECAST REMAINS IN PLACE AS CLOUDS AND SHOWERS WILL CONTINUE TO OVERSPREAD THE CWFA THIS MORNING. PREV DISC... SURFACE ANALYSIS HAS A WARM FRONT DRAPED ACROSS WESTERN NY INTO CENTRAL PA AND OFF THE MID ATLANTIC COAST. IN THE UPPER LEVELS...H2O VAPOR LOOP SHOWS A WEAK SHORT WAVE APPROACHING WESTERN NY WHERE RUC13 ISENTROPIC ANALYSIS ON THE 300-305K SURFACE REVEALS BROAD LIFT. REGIONAL RADARS CONFIRM THIS WITH SHOWERS AND SOME THUNDERSTORMS /PER THE NLDN/ ACROSS THE MOHAWK VALLEY WITH MORE CONCENTRATION OF ACTIVITY ACROSS WESTERN NY. TRENDS FOR THE DAYLIGHT HOURS ARE FOR ADDITIONAL SHOWERS AND SOME THUNDERSTORMS TO MOVE ACROSS THE REGION WITH THE BETTER CONCENTRATION ALONG THE I90 CORRIDOR WHERE THE WARM FRONT IS FORECAST TO BE PLACED WITH ADDITIONAL MID LEVEL INSTABILITY PER THE SHOWALTER VALUES AROUND 0C. THIS TOO IS SUGGESTED BY THE HRRR EXPERIENTIAL REFLECTIVITY FORECASTS. WITH CONSIDERABLE CLOUD COVER EXPECTED...HAVE SHADED ON THE COOLER SIDE OF THE GUIDANCE. THE AFOREMENTIONED SHORT WAVE IS FORECAST TO EXIT OUR REGION BY THIS EVENING. SOME RESIDUAL SHOWERS AND PERHAPS A RUMBLE OF THUNDER ARE EXPECTED THROUGH EARLY THIS EVENING...THEN ISOLATED ACTIVITY FOR THE REMAINDER OF THE OVERNIGHT PERIOD. WARM FRONT WILL BE IN THE VICINITY OF THE REGION SO CLOUD COVER WILL LIKELY BE IN PLACE AND POCKETS OF DRIZZLE AS THE LOWER LEVELS ARE EXPECTED TO BE QUITE MOIST PER TH BUFR SOUNDINGS. LOW LEVEL FLOW SLOWLY INCREASES FROM THE NORTH WHICH WILL PLAY HAVOC ON TEMPERATURES TONIGHT. GUIDANCE NUMBERS ARE RATHER CLOSE AS WE UTILIZED A BLENDED APPROACH. HOWEVER...IF THE DRAINAGE IS A BIT STRONGER...THEN TEMPERATURES COULD BE A LITTLE COOLER. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... THE CENTRAL PLAINS STORM IS FORECAST TO BE QUITE MATURE AT THIS TIME FRAME. MEANWHILE...THE WARM FRONT REMAINS IN THE VICINITY WITH SOME TENDENCY TO SLIP A LITTLE FURTHER SOUTH AS HIGH PRESSURE ACROSS SOUTHERN CANADA ATTEMPTS TO NOSE SOUTHWARD ACROSS OUR REGION SATURDAY. EITHER WAY...CONSIDERABLE CLOUDINESS IS EXPECTED AS LOWER LEVELS REMAIN QUITE MOIST ALONG WITH A SLIGHT CHANCE FOR A SHOWER. WE WILL SHADE ON THE COOLER SIDE OF THE GUIDANCE ENVELOPE AS THE LOW LEVEL NORTHERLY FLOW AND CLOUD COVER SHOULD KEEP TEMPS INTO THE 60S FOR MOST LOCATIONS WITH LOWER 70S FOR THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD COUNTY. THE WARM FRONT WILL ATTEMPT TO SLOWLY LIFT NORTHWARD SATURDAY NIGHT AND THROUGH SUNDAY. MOISTURE TRANSPORT AND ASSOCIATED LIFT INCREASES TO OUR WEST AND NORTH WHERE WE WILL PLACE THE HIGHER POPS. TEMPERATURES WILL BE RATHER STAGNATE AS SUGGESTED BY THE GFS-MOS WITH NOT MUCH RANGE EXPECTED. IT DOES SEEM WE WILL BECOME ENTRENCHED INTO THE WARM SECTOR DURING SUNDAY BUT THE COMBINATION OF MARINE AIR INFLUENCE AND CLOUD COVER THOSE H850 TEMPS INTO THE LOW-MID TEENS WILL NOT BE FULLY REALIZED. THUS WE HAVE LOWERED HIGH TEMPERATURES A FEW DEGREES. AS FOR PRECIP CHANCES...MAINLY TO OUR WEST AND NORTH ONCE AGAIN AND AS THIS FRONT LIFTS FURTHER NORTH...SO WILL THE DECREASING TENDENCY FOR SHOWERS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE EXTENDED PERIOD WILL START OFF RATHER ACTIVE...BUT ANOTHER EXTENDED PERIOD OF DRY AND MILD WEATHER WILL FOLLOW. OUR REGION WILL BE IN A WARM SECTOR OF A FRONTAL SYSTEM ON SUNDAY NIGHT. WITH PLENTY OF MOISTURE IN PLACE...THERE WILL BE A CHC FOR RAIN SHOWERS ACROSS THE ENTIRE REGION. THE BEST CHC FOR RAIN SHOWERS WILL BE ACROSS FAR NORTHWESTERN PARTS OF THE REGION...ESP TOWARDS SUNRISE MONDAY. WITH A SOUTHERLY FLOW IN PLACE...IT WILL BE MILD AND MUGGY...WITH MIN TEMPS IN THE MID 50S TO LOW 60S. A STRONG COLD FRONT WILL BE MOVING ACROSS THE REGION SOMETIME MONDAY INTO MONDAY EVENING. THE MODELS DON/T AGREE ON THE EXACT TIMING RIGHT NOW...WITH THE 00Z GFS A LITTLE FASTER THAN THE 00Z ECMWF. BY THIS POINT....NHC SHOWS THAT TC KAREN BE IN THE PROCESS OF TRANSITIONING FROM A TROPICAL ENTITY...AND THE REMAINS LOOK TO BE ABSORBED ALONG THE FRONTAL BOUNDARY WELL TO OUR SOUTH. STILL...A STRONG LOW LEVEL JET OF 50-60 KTS WILL TRANSPORT PLENTY OF MOISTURE UP ALONG THE FRONT FROM THE GULF OF MEXICO...WITH PWAT VALUES EXCEEDING 1.50 INCHES ACROSS OUR REGION. WITH THE STRONG SFC FORCING...A BAND OF LOCALLY HEAVY RAIN SHOWERS WILL BE POSSIBLE JUST AHEAD AND ALONG THE FRONTAL BOUNDARY. ALONG WITH LIKELY POPS FOR RAIN SHOWERS...WE WILL INCLUDE A SLIGHT CHC OF THUNDER...BUT WIDESPREAD THUNDER DOESN/T APPEAR LIKELY DUE TO MEAGER AMOUNTS OF INSTABILITY. IT WILL BE FAIRLY WARM ON MONDAY IN ADVANCE OF THE FRONTAL BOUNDARY WITH MID 60S TO MID 70S ACROSS THE REGION. MIN TEMPS WILL ON MONDAY NIGHT WILL BE COOLER THAN SUN NIGHT...BUT THE EXACT TIMING WILL DEPEND JUST HOW MUCH COOLS OFF. FOR NOW...WE ARE FORECASTING MIN TEMPS FROM THE LOW 40S IN THE DACKS TO THE MID 50S IN THE MID HUDSON VALLEY AND NW CT. WE WILL STILL ALLOW FOR A SHOWER ACROSS SOUTHERN AREAS TUESDAY MORNING IN CASE THE FRONT SLOWS...OTHERWISE THE COLD FRONT SHOULD HAVE PUSHED OFF TO OUR EAST BY TUESDAY...ALLOWING A DRIER AND SOMEWHAT COOLER AIR MASS TO MOVE INTO OUR REGION. IT WILL BE DRY FOR THE MID WEEK PERIOD /TUES AND WED/ WITH MAX TEMPS IN THE 60S...AND LOWS IN THE 40S /SOME 30S ACROSS THE ADIRONDACKS AND SRN GREEN MTNS/. THESE MAX TEMPS STILL LOOK A FEW DEGREES ABOVE NORMAL. BY LATE IN THE WEEK...STRONG RIDGING WILL REESTABLISH ITSELF ALONG THE EASTERN SEABOARD...AND EVEN MORE ABOVE NORMAL WARMTH WILL BE IN PLACE FOR THURS/FRI. IT WILL CONTINUE TO BE DRY...WITH DAYTIME TEMPS IN THE UPPER 60S TO MID 70S FOR VALLEY AREAS...AND MINS GENERALLY IN THE MID 40S TO LOW 50S. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... A WARM FRONT IS SITUATED SOUTH OF THE REGION IS SLOWLY MOVING NORTHWARD. OVC CIGS OF 4-6 KFT ARE IN PLACE ACROSS THE REGION. REGIONAL MOSAIC RADAR SHOWS SOME SHOWERS WEST OF THE REGION...AND THESE MAY AFFECT MAINLY THE NORTHERN SITES THROUGH THE MORNING HOURS. WILL INCLUDE A VCSH AT ALL SITES WITH A TEMPO FOR MVFR CIGS/VSBYS WITHIN RAIN SHOWERS FOR KALB/KGFL/KPSF. AT THIS POINT...WIDESPREAD IFR CONDITIONS ARE NOT ANTICIPATED TODAY. LIGHT AND VARIABLE WINDS ARE EXPECTED TODAY. FLYING CONDITIONS WILL GENERALLY BE VFR DURING THE AFTN HOURS FOR THE VALLEY TERMINALS...ALTHOUGH CIGS MAY REMAIN MVFR AT KPSF. WITH LOW LEVEL MOISTURE REMAINING HIGH TONIGHT...ALL SITES LOOK TO HAVE MVFR CIGS TONIGHT WITH MVFR BR POSSIBLE AT KPSF/KPOU AS WELL. ALTHOUGH NOT AS WIDESPREAD AS THIS MORNING...STILL CANNOT RULE OUT A SHOWER OR TWO THIS AFTERNOON INTO TONIGHT AS WELL. WINDS WILL BE NEARLY CALM TONIGHT. OUTLOOK... SATURDAY-SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SUNDAY-MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .FIRE WEATHER... A WARM FRONT WILL LIFT SLOWLY NORTHWARD FROM THE LOWER GREAT LAKES REGION AND THE MID ATLANTIC STATES. THIS FRONT WILL PRODUCE SCATTERED SHOWERS ALONG WITH A FEW RUMBLES OF THUNDER THROUGH TODAY FROM THE MOHAWK VALLEY AND THE CAPITAL REGION SOUTH. INCREASING HUMIDITY LEVELS...AND THE THREAT FOR ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH THE WEEKEND WITH THE BOUNDARY IN THE VICINITY OF THE REGION. THE RH VALUES WILL FALL TO 50 TO 65 PERCENT THIS AFTERNOON...THEN RECOVER TO 80 TO 100 PERCENT BY SATURDAY MORNING. THE WINDS BECOME LIGHT TO CALM THIS MORNING AND SATURDAY NIGHT...THEN BE FROM THE EAST TO NORTHEAST AT 5 TO 10 MPH DURING THE DAYLIGHT HOURS TODAY. A COLD FRONT WILL BRING WIDESPREAD SHOWERS TO THE REGION LATE SUNDAY INTO EARLY NEXT WEEK. && .HYDROLOGY... NO WIDESPREAD PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE NEXT 5 DAYS. FLOWS CONTINUE AT NORMAL TO BELOW NORMAL LEVELS FOR EARLY OCTOBER. THE DRY WEATHER STRETCH OVER THE PAST 10 DAYS OR SO WILL BE COMING TO AN END AS A WARM FRONT APPROACHES ALONG WITH THE CHANCE FOR SHOWERS FOR THE REMAINDER OF THIS WEEK AND INTO THE WEEKEND. AT THIS TIME...QPF AMOUNTS RANGE FROM A TENTH OF AN INCH OVER THE NRN PORTIONS OF THE HSA TO A THIRD OF AN INCH OVER THE SRN THIRD FROM TONIGHT INTO SATURDAY MORNING. THERE IS SIGNIFICANT UNCERTAINTY IN THE GUIDANCE IN THE TIMING AND TRACK OF A STRONGER LOW PRESSURE SYSTEM AND ITS FRONTAL BOUNDARY FOR LATE IN THE WEEKEND AND EARLY NEXT WEEK. FURTHERMORE...WE CONTINUE TO MONITOR TRENDS ON THE TRACK OF TS KAREN IN THE GULF OF MEXICO FROM THE GUIDANCE FROM THE NATIONAL HURRICANE CENTER. THE AMOUNT OF RAINFALL VARIES GREATLY IN THE GUIDANCE AT THIS TIME FOR PORTIONS OF EXTREME SRN NY AND NEW ENGLAND EARLY IN THE WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
610 AM EDT FRI OCT 4 2013 .SYNOPSIS... A WARM FRONT WILL LIFT SLOWLY NORTHWARD FROM THE LOWER GREAT LAKES REGION AND THE MID ATLANTIC STATES. THIS FRONT WILL PRODUCE SCATTERED SHOWERS ALONG WITH A FEW RUMBLES OF THUNDER THROUGH TODAY FROM THE MOHAWK VALLEY AND THE CAPITAL REGION SOUTH. INCREASING HUMIDITY LEVELS...AND THE THREAT FOR ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH THE WEEKEND WITH THE BOUNDARY IN THE VICINITY OF THE REGION. && .NEAR TERM /THROUGH TONIGHT/... AS OF 6 AM EDT...BANDS OF SHOWERS/STORMS HAS DEVELOPED ALONG AND JUST NORTH OF THE I90 CORRIDOR PER THE LATEST RADAR SCANS THIS MORNING. THE THETA-E ADVECTION WAS A TOUCH STRONGER AND FURTHER NORTH PER THE HOURLY RUC13 ANALYSIS AND HAVE ADJUSTED THE FORECAST/GRIDS ACCORDINGLY. OTHERWISE...FORECAST REMAINS IN PLACE AS CLOUDS AND SHOWERS WILL CONTINUE TO OVERSPREAD THE CWFA THIS MORNING. PREV DISC... SURFACE ANALYSIS HAS A WARM FRONT DRAPED ACROSS WESTERN NY INTO CENTRAL PA AND OFF THE MID ATLANTIC COAST. IN THE UPPER LEVELS...H2O VAPOR LOOP SHOWS A WEAK SHORT WAVE APPROACHING WESTERN NY WHERE RUC13 ISENTROPIC ANALYSIS ON THE 300-305K SURFACE REVEALS BROAD LIFT. REGIONAL RADARS CONFIRM THIS WITH SHOWERS AND SOME THUNDERSTORMS /PER THE NLDN/ ACROSS THE MOHAWK VALLEY WITH MORE CONCENTRATION OF ACTIVITY ACROSS WESTERN NY. TRENDS FOR THE DAYLIGHT HOURS ARE FOR ADDITIONAL SHOWERS AND SOME THUNDERSTORMS TO MOVE ACROSS THE REGION WITH THE BETTER CONCENTRATION ALONG THE I90 CORRIDOR WHERE THE WARM FRONT IS FORECAST TO BE PLACED WITH ADDITIONAL MID LEVEL INSTABILITY PER THE SHOWALTER VALUES AROUND 0C. THIS TOO IS SUGGESTED BY THE HRRR EXPERIENTIAL REFLECTIVITY FORECASTS. WITH CONSIDERABLE CLOUD COVER EXPECTED...HAVE SHADED ON THE COOLER SIDE OF THE GUIDANCE. THE AFOREMENTIONED SHORT WAVE IS FORECAST TO EXIT OUR REGION BY THIS EVENING. SOME RESIDUAL SHOWERS AND PERHAPS A RUMBLE OF THUNDER ARE EXPECTED THROUGH EARLY THIS EVENING...THEN ISOLATED ACTIVITY FOR THE REMAINDER OF THE OVERNIGHT PERIOD. WARM FRONT WILL BE IN THE VICINITY OF THE REGION SO CLOUD COVER WILL LIKELY BE IN PLACE AND POCKETS OF DRIZZLE AS THE LOWER LEVELS ARE EXPECTED TO BE QUITE MOIST PER TH BUFR SOUNDINGS. LOW LEVEL FLOW SLOWLY INCREASES FROM THE NORTH WHICH WILL PLAY HAVOC ON TEMPERATURES TONIGHT. GUIDANCE NUMBERS ARE RATHER CLOSE AS WE UTILIZED A BLENDED APPROACH. HOWEVER...IF THE DRAINAGE IS A BIT STRONGER...THEN TEMPERATURES COULD BE A LITTLE COOLER. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... THE CENTRAL PLAINS STORM IS FORECAST TO BE QUITE MATURE AT THIS TIME FRAME. MEANWHILE...THE WARM FRONT REMAINS IN THE VICINITY WITH SOME TENDENCY TO SLIP A LITTLE FURTHER SOUTH AS HIGH PRESSURE ACROSS SOUTHERN CANADA ATTEMPTS TO NOSE SOUTHWARD ACROSS OUR REGION SATURDAY. EITHER WAY...CONSIDERABLE CLOUDINESS IS EXPECTED AS LOWER LEVELS REMAIN QUITE MOIST ALONG WITH A SLIGHT CHANCE FOR A SHOWER. WE WILL SHADE ON THE COOLER SIDE OF THE GUIDANCE ENVELOPE AS THE LOW LEVEL NORTHERLY FLOW AND CLOUD COVER SHOULD KEEP TEMPS INTO THE 60S FOR MOST LOCATIONS WITH LOWER 70S FOR THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD COUNTY. THE WARM FRONT WILL ATTEMPT TO SLOWLY LIFT NORTHWARD SATURDAY NIGHT AND THROUGH SUNDAY. MOISTURE TRANSPORT AND ASSOCIATED LIFT INCREASES TO OUR WEST AND NORTH WHERE WE WILL PLACE THE HIGHER POPS. TEMPERATURES WILL BE RATHER STAGNATE AS SUGGESTED BY THE GFS-MOS WITH NOT MUCH RANGE EXPECTED. IT DOES SEEM WE WILL BECOME ENTRENCHED INTO THE WARM SECTOR DURING SUNDAY BUT THE COMBINATION OF MARINE AIR INFLUENCE AND CLOUD COVER ...THOSE H850 TEMPS INTO THE LOW-MID TEENS WILL NOT BE FULLY REALIZED. THUS WE HAVE LOWERED HIGH TEMPERATURES A FEW DEGREES. AS FOR PRECIP CHANCES...MAINLY TO OUR WEST AND NORTH ONCE AGAIN AND AS THIS FRONT LIFTS FURTHER NORTH...SO WILL THE DECREASING TENDENCY FOR SHOWERS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE EXTENDED PERIOD WILL START OFF RATHER ACTIVE...BUT ANOTHER EXTENDED PERIOD OF DRY AND MILD WEATHER WILL FOLLOW. OUR REGION WILL BE IN A WARM SECTOR OF A FRONTAL SYSTEM ON SUNDAY NIGHT. WITH PLENTY OF MOISTURE IN PLACE...THERE WILL BE A CHC FOR RAIN SHOWERS ACROSS THE ENTIRE REGION. THE BEST CHC FOR RAIN SHOWERS WILL BE ACROSS FAR NORTHWESTERN PARTS OF THE REGION...ESP TOWARDS SUNRISE MONDAY. WITH A SOUTHERLY FLOW IN PLACE...IT WILL BE MILD AND MUGGY...WITH MIN TEMPS IN THE MID 50S TO LOW 60S. A STRONG COLD FRONT WILL BE MOVING ACROSS THE REGION SOMETIME MONDAY INTO MONDAY EVENING. THE MODELS DON/T AGREE ON THE EXACT TIMING RIGHT NOW...WITH THE 00Z GFS A LITTLE FASTER THAN THE 00Z ECMWF. BY THIS POINT....NHC SHOWS THAT TC KAREN BE IN THE PROCESS OF TRANSITIONING FROM A TROPICAL ENTITY...AND THE REMAINS LOOK TO BE ABSORBED ALONG THE FRONTAL BOUNDARY WELL TO OUR SOUTH. STILL...A STRONG LOW LEVEL JET OF 50-60 KTS WILL TRANSPORT PLENTY OF MOISTURE UP ALONG THE FRONT FROM THE GULF OF MEXICO...WITH PWAT VALUES EXCEEDING 1.50 INCHES ACROSS OUR REGION. WITH THE STRONG SFC FORCING...A BAND OF LOCALLY HEAVY RAIN SHOWERS WILL BE POSSIBLE JUST AHEAD AND ALONG THE FRONTAL BOUNDARY. ALONG WITH LIKELY POPS FOR RAIN SHOWERS...WE WILL INCLUDE A SLIGHT CHC OF THUNDER...BUT WIDESPREAD THUNDER DOESN/T APPEAR LIKELY DUE TO MEAGER AMOUNTS OF INSTABILITY. IT WILL BE FAIRLY WARM ON MONDAY IN ADVANCE OF THE FRONTAL BOUNDARY WITH MID 60S TO MID 70S ACROSS THE REGION. MIN TEMPS WILL ON MONDAY NIGHT WILL BE COOLER THAN SUN NIGHT...BUT THE EXACT TIMING WILL DEPEND JUST HOW MUCH COOLS OFF. FOR NOW...WE ARE FORECASTING MIN TEMPS FROM THE LOW 40S IN THE DACKS TO THE MID 50S IN THE MID HUDSON VALLEY AND NW CT. WE WILL STILL ALLOW FOR A SHOWER ACROSS SOUTHERN AREAS TUESDAY MORNING IN CASE THE FRONT SLOWS...OTHERWISE THE COLD FRONT SHOULD HAVE PUSHED OFF TO OUR EAST BY TUESDAY...ALLOWING A DRIER AND SOMEWHAT COOLER AIR MASS TO MOVE INTO OUR REGION. IT WILL BE DRY FOR THE MID WEEK PERIOD /TUES AND WED/ WITH MAX TEMPS IN THE 60S...AND LOWS IN THE 40S /SOME 30S ACROSS THE ADIRONDACKS AND SRN GREEN MTNS/. THESE MAX TEMPS STILL LOOK A FEW DEGREES ABOVE NORMAL. BY LATE IN THE WEEK...STRONG RIDGING WILL REESTABLISH ITSELF ALONG THE EASTERN SEABOARD...AND EVEN MORE ABOVE NORMAL WARMTH WILL BE IN PLACE FOR THURS/FRI. IT WILL CONTINUE TO BE DRY...WITH DAYTIME TEMPS IN THE UPPER 60S TO MID 70S FOR VALLEY AREAS...AND MINS GENERALLY IN THE MID 40S TO LOW 50S. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... MID AND HIGH LEVEL CLOUDS ARE INCREASING ACROSS THE REGION AS A WARM FRONT APPROACHES THE AREA. THE HIGH CLOUDS HAVE BEEN THIN ENOUGH FOR TEMPS TO COOL RAPIDLY DOWN TO THE DEWPOINT AT KGFL...WHICH HAS ALLOWED SOME IFR FOG TO DEVELOP THERE. PERIODS OF IFR FOG WILL BE POSSIBLE THROUGH THE REMAINDER OF THE NIGHT AT KGFL. OTHERWISE...INCREASING AMOUNTS OF CLOUDS SHOULD PREVENT RADIATIONAL FOG FROM DEVELOPING FURTHER SOUTH AT KALB/KPSF/KPOU. WINDS WILL BE CALM FOR THE REMAINDER OF THE OVERNIGHT HOURS. ANY FOG WILL DISSIPATE AT KGFL BY AROUND SUNRISE. CLOUDS WILL CONTINUE TO LOWER WITH BKN-OVC STRATUS CLOUDS AT 5-8 KFT. SOME LIGHT RAIN SHOWERS WILL BE POSSIBLE BEGINNING IN THE MORNING HOURS AS THE WARM FRONT GETS CLOSER. WE HAVE INCLUDED A VCSH AT ALL SITES TO ACCOUNT FOR THIS POSSIBILITY. IT/S POSSIBLE THAT A BRIEF PERIOD OF MVFR VSBYS/CIGS IS POSSIBLE WITHIN ANY RAIN SHOWERS WITH THE PASSAGE OF THE WARM FRONT DURING THE DAY FRIDAY INTO FRIDAY EVENING...BUT UNCERTAINTY REGARDING THE TIMING/EXTENT OF THIS PREVENTS THE INCLUSION IN THE TAF AT THIS TIME...EXCEPT FOR AT KPSF...WHERE MVFR CIGS ARE EXPECTED AFTER 16Z. CIGS MAY LOWER TO AROUND 3500-5000 FT BY AFTERNOON HOURS FOR KALB/KGFL/KPOU. LIGHT AND VARIABLE WINDS ARE EXPECTED DURING THE DAY FRIDAY AND INTO FRIDAY EVENING. OUTLOOK... FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SATURDAY NIGHT TO SUNDAY: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SUNDAY NIGHT TO TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA. && .FIRE WEATHER... A WARM FRONT WILL LIFT SLOWLY NORTHWARD FROM THE LOWER GREAT LAKES REGION AND THE MID ATLANTIC STATES. THIS FRONT WILL PRODUCE SCATTERED SHOWERS ALONG WITH A FEW RUMBLES OF THUNDER THROUGH TODAY FROM THE MOHAWK VALLEY AND THE CAPITAL REGION SOUTH. INCREASING HUMIDITY LEVELS...AND THE THREAT FOR ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH THE WEEKEND WITH THE BOUNDARY IN THE VICINITY OF THE REGION. THE RH VALUES WILL FALL TO 50 TO 65 PERCENT THIS AFTERNOON...THEN RECOVER TO 80 TO 100 PERCENT BY SATURDAY MORNING. THE WINDS BECOME LIGHT TO CALM THIS MORNING AND SATURDAY NIGHT...THEN BE FROM THE EAST TO NORTHEAST AT 5 TO 10 MPH DURING THE DAYLIGHT HOURS TODAY. A COLD FRONT WILL BRING WIDESPREAD SHOWERS TO THE REGION LATE SUNDAY INTO EARLY NEXT WEEK. && .HYDROLOGY... NO WIDESPREAD PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE NEXT 5 DAYS. FLOWS CONTINUE AT NORMAL TO BELOW NORMAL LEVELS FOR EARLY OCTOBER. THE DRY WEATHER STRETCH OVER THE PAST 10 DAYS OR SO WILL BE COMING TO AN END AS A WARM FRONT APPROACHES ALONG WITH THE CHANCE FOR SHOWERS FOR THE REMAINDER OF THIS WEEK AND INTO THE WEEKEND. AT THIS TIME...QPF AMOUNTS RANGE FROM A TENTH OF AN INCH OVER THE NRN PORTIONS OF THE HSA TO A THIRD OF AN INCH OVER THE SRN THIRD FROM TONIGHT INTO SATURDAY MORNING. THERE IS SIGNIFICANT UNCERTAINTY IN THE GUIDANCE IN THE TIMING AND TRACK OF A STRONGER LOW PRESSURE SYSTEM AND ITS FRONTAL BOUNDARY FOR LATE IN THE WEEKEND AND EARLY NEXT WEEK. FURTHERMORE...WE CONTINUE TO MONITOR TRENDS ON THE TRACK OF TS KAREN IN THE GULF OF MEXICO FROM THE GUIDANCE FROM THE NATIONAL HURRICANE CENTER. THE AMOUNT OF RAINFALL VARIES GREATLY IN THE GUIDANCE AT THIS TIME FOR PORTIONS OF EXTREME SRN NY AND NEW ENGLAND EARLY IN THE WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
354 AM EDT FRI OCT 4 2013 .SYNOPSIS... A WARM FRONT WILL LIFT SLOWLY NORTHWARD FROM THE LOWER GREAT LAKES REGION AND THE MID ATLANTIC STATES. THIS FRONT WILL PRODUCE SCATTERED SHOWERS ALONG WITH A FEW RUMBLES OF THUNDER THROUGH TODAY FROM THE MOHAWK VALLEY AND THE CAPITAL REGION SOUTH. INCREASING HUMIDITY LEVELS...AND THE THREAT FOR ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH THE WEEKEND WITH THE BOUNDARY IN THE VICINITY OF THE REGION. && .NEAR TERM /THROUGH TONIGHT/... SURFACE ANALYSIS HAS A WARM FRONT DRAPED ACROSS WESTERN NY INTO CENTRAL PA AND OFF THE MID ATLANTIC COAST. IN THE UPPER LEVELS...H2O VAPOR LOOP SHOWS A WEAK SHORT WAVE APPROACHING WESTERN NY WHERE RUC13 ISENTROPIC ANALYSIS ON THE 300-305K SURFACE REVEALS BROAD LIFT. REGIONAL RADARS CONFIRM THIS WITH SHOWERS AND SOME THUNDERSTORMS /PER THE NLDN/ ACROSS THE MOHAWK VALLEY WITH MORE CONCENTRATION OF ACTIVITY ACROSS WESTERN NY. TRENDS FOR THE DAYLIGHT HOURS ARE FOR ADDITIONAL SHOWERS AND SOME THUNDERSTORMS TO MOVE ACROSS THE REGION WITH THE BETTER CONCENTRATION ALONG THE I90 CORRIDOR WHERE THE WARM FRONT IS FORECAST TO BE PLACED WITH ADDITIONAL MID LEVEL INSTABILITY PER THE SHOWALTER VALUES AROUND 0C. THIS TOO IS SUGGESTED BY THE HRRR EXPERIENTIAL REFLECTIVITY FORECASTS. WITH CONSIDERABLE CLOUD COVER EXPECTED...HAVE SHADED ON THE COOLER SIDE OF THE GUIDANCE. THE AFOREMENTIONED SHORT WAVE IS FORECAST TO EXIT OUR REGION BY THIS EVENING. SOME RESIDUAL SHOWERS AND PERHAPS A RUMBLE OF THUNDER ARE EXPECTED THROUGH EARLY THIS EVENING...THEN ISOLATED ACTIVITY FOR THE REMAINDER OF THE OVERNIGHT PERIOD. WARM FRONT WILL BE IN THE VICINITY OF THE REGION SO CLOUD COVER WILL LIKELY BE IN PLACE AND POCKETS OF DRIZZLE AS THE LOWER LEVELS ARE EXPECTED TO BE QUITE MOIST PER TH BUFR SOUNDINGS. LOW LEVEL FLOW SLOWLY INCREASES FROM THE NORTH WHICH WILL PLAY HAVOC ON TEMPERATURES TONIGHT. GUIDANCE NUMBERS ARE RATHER CLOSE AS WE UTILIZED A BLENDED APPROACH. HOWEVER...IF THE DRAINAGE IS A BIT STRONGER...THEN TEMPERATURES COULD BE A LITTLE COOLER. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... THE CENTRAL PLAINS STORM IS FORECAST TO BE QUITE MATURE AT THIS TIME FRAME. MEANWHILE...THE WARM FRONT REMAINS IN THE VICINITY WITH SOME TENDENCY TO SLIP A LITTLE FURTHER SOUTH AS HIGH PRESSURE ACROSS SOUTHERN CANADA ATTEMPTS TO NOSE SOUTHWARD ACROSS OUR REGION SATURDAY. EITHER WAY...CONSIDERABLE CLOUDINESS IS EXPECTED AS LOWER LEVELS REMAIN QUITE MOIST ALONG WITH A SLIGHT CHANCE FOR A SHOWER. WE WILL SHADE ON THE COOLER SIDE OF THE GUIDANCE ENVELOPE AS THE LOW LEVEL NORTHERLY FLOW AND CLOUD COVER SHOULD KEEP TEMPS INTO THE 60S FOR MOST LOCATIONS WITH LOWER 70S FOR THE MID HUDSON VALLEY AND SOUTHERN LITCHFIELD COUNTY. THE WARM FRONT WILL ATTEMPT TO SLOWLY LIFT NORTHWARD SATURDAY NIGHT AND THROUGH SUNDAY. MOISTURE TRANSPORT AND ASSOCIATED LIFT INCREASES TO OUR WEST AND NORTH WHERE WE WILL PLACE THE HIGHER POPS. TEMPERATURES WILL BE RATHER STAGNATE AS SUGGESTED BY THE GFS-MOS WITH NOT MUCH RANGE EXPECTED. IT DOES SEEM WE WILL BECOME ENTRENCHED INTO THE WARM SECTOR DURING SUNDAY BUT THE COMBINATION OF MARINE AIR INFLUENCE AND CLOUD COVER ...THOSE H850 TEMPS INTO THE LOW-MID TEENS WILL NOT BE FULLY REALIZED. THUS WE HAVE LOWERED HIGH TEMPERATURES A FEW DEGREES. AS FOR PRECIP CHANCES...MAINLY TO OUR WEST AND NORTH ONCE AGAIN AND AS THIS FRONT LIFTS FURTHER NORTH...SO WILL THE DECREASING TENDENCY FOR SHOWERS. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... THE EXTENDED PERIOD WILL START OFF RATHER ACTIVE...BUT ANOTHER EXTENDED PERIOD OF DRY AND MILD WEATHER WILL FOLLOW. OUR REGION WILL BE IN A WARM SECTOR OF A FRONTAL SYSTEM ON SUNDAY NIGHT. WITH PLENTY OF MOISTURE IN PLACE...THERE WILL BE A CHC FOR RAIN SHOWERS ACROSS THE ENTIRE REGION. THE BEST CHC FOR RAIN SHOWERS WILL BE ACROSS FAR NORTHWESTERN PARTS OF THE REGION...ESP TOWARDS SUNRISE MONDAY. WITH A SOUTHERLY FLOW IN PLACE...IT WILL BE MILD AND MUGGY...WITH MIN TEMPS IN THE MID 50S TO LOW 60S. A STRONG COLD FRONT WILL BE MOVING ACROSS THE REGION SOMETIME MONDAY INTO MONDAY EVENING. THE MODELS DON/T AGREE ON THE EXACT TIMING RIGHT NOW...WITH THE 00Z GFS A LITTLE FASTER THAN THE 00Z ECMWF. BY THIS POINT....NHC SHOWS THAT TC KAREN BE IN THE PROCESS OF TRANSITIONING FROM A TROPICAL ENTITY...AND THE REMAINS LOOK TO BE ABSORBED ALONG THE FRONTAL BOUNDARY WELL TO OUR SOUTH. STILL...A STRONG LOW LEVEL JET OF 50-60 KTS WILL TRANSPORT PLENTY OF MOISTURE UP ALONG THE FRONT FROM THE GULF OF MEXICO...WITH PWAT VALUES EXCEEDING 1.50 INCHES ACROSS OUR REGION. WITH THE STRONG SFC FORCING...A BAND OF LOCALLY HEAVY RAIN SHOWERS WILL BE POSSIBLE JUST AHEAD AND ALONG THE FRONTAL BOUNDARY. ALONG WITH LIKELY POPS FOR RAIN SHOWERS...WE WILL INCLUDE A SLIGHT CHC OF THUNDER...BUT WIDESPREAD THUNDER DOESN/T APPEAR LIKELY DUE TO MEAGER AMOUNTS OF INSTABILITY. IT WILL BE FAIRLY WARM ON MONDAY IN ADVANCE OF THE FRONTAL BOUNDARY WITH MID 60S TO MID 70S ACROSS THE REGION. MIN TEMPS WILL ON MONDAY NIGHT WILL BE COOLER THAN SUN NIGHT...BUT THE EXACT TIMING WILL DEPEND JUST HOW MUCH COOLS OFF. FOR NOW...WE ARE FORECASTING MIN TEMPS FROM THE LOW 40S IN THE DACKS TO THE MID 50S IN THE MID HUDSON VALLEY AND NW CT. WE WILL STILL ALLOW FOR A SHOWER ACROSS SOUTHERN AREAS TUESDAY MORNING IN CASE THE FRONT SLOWS...OTHERWISE THE COLD FRONT SHOULD HAVE PUSHED OFF TO OUR EAST BY TUESDAY...ALLOWING A DRIER AND SOMEWHAT COOLER AIR MASS TO MOVE INTO OUR REGION. IT WILL BE DRY FOR THE MID WEEK PERIOD /TUES AND WED/ WITH MAX TEMPS IN THE 60S...AND LOWS IN THE 40S /SOME 30S ACROSS THE ADIRONDACKS AND SRN GREEN MTNS/. THESE MAX TEMPS STILL LOOK A FEW DEGREES ABOVE NORMAL. BY LATE IN THE WEEK...STRONG RIDGING WILL REESTABLISH ITSELF ALONG THE EASTERN SEABOARD...AND EVEN MORE ABOVE NORMAL WARMTH WILL BE IN PLACE FOR THURS/FRI. IT WILL CONTINUE TO BE DRY...WITH DAYTIME TEMPS IN THE UPPER 60S TO MID 70S FOR VALLEY AREAS...AND MINS GENERALLY IN THE MID 40S TO LOW 50S. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... MID AND HIGH LEVEL CLOUDS ARE INCREASING ACROSS THE REGION AS A WARM FRONT APPROACHES THE AREA. THE HIGH CLOUDS HAVE BEEN THIN ENOUGH FOR TEMPS TO COOL RAPIDLY DOWN TO THE DEWPOINT AT KGFL...WHICH HAS ALLOWED SOME IFR FOG TO DEVELOP THERE. PERIODS OF IFR FOG WILL BE POSSIBLE THROUGH THE REMAINDER OF THE NIGHT AT KGFL. OTHERWISE...INCREASING AMOUNTS OF CLOUDS SHOULD PREVENT RADIATIONAL FOG FROM DEVELOPING FURTHER SOUTH AT KALB/KPSF/KPOU. WINDS WILL BE CALM FOR THE REMAINDER OF THE OVERNIGHT HOURS. ANY FOG WILL DISSIPATE AT KGFL BY AROUND SUNRISE. CLOUDS WILL CONTINUE TO LOWER WITH BKN-OVC STRATUS CLOUDS AT 5-8 KFT. SOME LIGHT RAIN SHOWERS WILL BE POSSIBLE BEGINNING IN THE MORNING HOURS AS THE WARM FRONT GETS CLOSER. WE HAVE INCLUDED A VCSH AT ALL SITES TO ACCOUNT FOR THIS POSSIBILITY. IT/S POSSIBLE THAT A BRIEF PERIOD OF MVFR VSBYS/CIGS IS POSSIBLE WITHIN ANY RAIN SHOWERS WITH THE PASSAGE OF THE WARM FRONT DURING THE DAY FRIDAY INTO FRIDAY EVENING...BUT UNCERTAINTY REGARDING THE TIMING/EXTENT OF THIS PREVENTS THE INCLUSION IN THE TAF AT THIS TIME...EXCEPT FOR AT KPSF...WHERE MVFR CIGS ARE EXPECTED AFTER 16Z. CIGS MAY LOWER TO AROUND 3500-5000 FT BY AFTERNOON HOURS FOR KALB/KGFL/KPOU. LIGHT AND VARIABLE WINDS ARE EXPECTED DURING THE DAY FRIDAY AND INTO FRIDAY EVENING. OUTLOOK... FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA. SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SATURDAY NIGHT TO SUNDAY: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA. SUNDAY NIGHT TO TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA. && .FIRE WEATHER... A WARM FRONT WILL LIFT SLOWLY NORTHWARD FROM THE LOWER GREAT LAKES REGION AND THE MID ATLANTIC STATES. THIS FRONT WILL PRODUCE SCATTERED SHOWERS ALONG WITH A FEW RUMBLES OF THUNDER THROUGH TODAY FROM THE MOHAWK VALLEY AND THE CAPITAL REGION SOUTH. INCREASING HUMIDITY LEVELS...AND THE THREAT FOR ISOLATED TO SCATTERED SHOWERS WILL CONTINUE THROUGH THE WEEKEND WITH THE BOUNDARY IN THE VICINITY OF THE REGION. THE RH VALUES WILL FALL TO 50 TO 65 PERCENT THIS AFTERNOON...THEN RECOVER TO 80 TO 100 PERCENT BY SATURDAY MORNING. THE WINDS BECOME LIGHT TO CALM THIS MORNING AND SATURDAY NIGHT...THEN BE FROM THE EAST TO NORTHEAST AT 5 TO 10 MPH DURING THE DAYLIGHT HOURS TODAY. A COLD FRONT WILL BRING WIDESPREAD SHOWERS TO THE REGION LATE SUNDAY INTO EARLY NEXT WEEK. && .HYDROLOGY... NO WIDESPREAD PROBLEMS ARE EXPECTED ON THE MAIN STEM RIVERS OVER THE NEXT 5 DAYS. FLOWS CONTINUE AT NORMAL TO BELOW NORMAL LEVELS FOR EARLY OCTOBER. THE DRY WEATHER STRETCH OVER THE PAST 10 DAYS OR SO WILL BE COMING TO AN END AS A WARM FRONT APPROACHES ALONG WITH THE CHANCE FOR SHOWERS FOR THE REMAINDER OF THIS WEEK AND INTO THE WEEKEND. AT THIS TIME...QPF AMOUNTS RANGE FROM A TENTH OF AN INCH OVER THE NRN PORTIONS OF THE HSA TO A THIRD OF AN INCH OVER THE SRN THIRD FROM TONIGHT INTO SATURDAY MORNING. THERE IS SIGNIFICANT UNCERTAINTY IN THE GUIDANCE IN THE TIMING AND TRACK OF A STRONGER LOW PRESSURE SYSTEM AND ITS FRONTAL BOUNDARY FOR LATE IN THE WEEKEND AND EARLY NEXT WEEK. FURTHERMORE...WE CONTINUE TO MONITOR TRENDS ON THE TRACK OF TS KAREN IN THE GULF OF MEXICO FROM THE GUIDANCE FROM THE NATIONAL HURRICANE CENTER. THE AMOUNT OF RAINFALL VARIES GREATLY IN THE GUIDANCE AT THIS TIME FOR PORTIONS OF EXTREME SRN NY AND NEW ENGLAND EARLY IN THE WEEK. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...BGM NEAR TERM...BGM SHORT TERM...BGM LONG TERM...FRUGIS AVIATION...FRUGIS FIRE WEATHER...BGM HYDROLOGY...BGM FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
705 PM CDT SAT OCT 5 2013 .UPDATE... 453 PM CDT ONE CLUSTER OF SEVERE STORMS CONTINUES TO MOVE ACROSS NORTHERN COOK COUNTY AND OUT OVER LAKE MICHIGAN AT 450 PM CDT WITH WEAKER THOUGH STILL INTENSE STORMS SOUTHWARD INTO KANKAKEE COUNTY. SURFACE OBS SHOW AN AREA OF LOW LEVEL CONVERGENCE WHICH HAS DEVELOPED FROM EASTERN WILL OR CENTRAL KANKAKEE COUNTY SOUTHWESTWARD TOWARD BLOOMINGTON AND LINCOLN. ANOTHER SHORTWAVE IS MOVING NORTHEAST ACROSS WESTERN IL WITH AN AREA OF RAIN SHOWERS CLOSELY TIED TO IT APPROACHING LACON...PEORIA AND SPRINGFIELD. RADAR MOSAIC ALSO SHOWS SOME SPOTTY ECHOES DEVELOPING ALONG THE AFOREMENTIONED CONVERGENCE/TROUGH...LIKELY BEING AIDED BY THE APPROACHING WAVE. EXPECT THAT DEVELOPMENT WILL CONTINUE ALONG THE TROUGH FROM GARY TO KANKAKEE TO PONTIAC AND MOVE EAST-NORTHEAST OVER THE NEXT FEW HOURS. RAIN COOLED AIR IS TO THE SOUTH AND EAST OF THIS AREA WITH TEMPS IN THE 60S BUT MUCH OF THE SOUTHEAST CWA ITSELF HAS REMAINED NORTH OF THE RAIN ACTIVITY SO INSTABILITY IS STILL SUFFICIENT. LATEST RAP ANALYSIS SHOWS THE EFFECTIVE SHEAR HAS INCREASED INTO THE 40 KT RANGE. THEREFORE THE SEVERE THREAT WILL CONTINUE AND LIKELY BE FOCUSED ALONG AND EAST OF THE GARY TO KANKAKEE TO PONTIAC LINE WITH A SHORTER TERM THREAT ALSO CONTINUING ACROSS EASTERN LAKE COUNTY IL AND ADJACENT LAKE MICHIGAN WATERS AS EXISTING STORM CLUSTER MOVES OFFSHORE. HEAVY RAINFALL WILL CONTINUE WITH ANY STORMS WITH REPORTS OF 1 TO 1.5 INCHES OF RAIN IN LESS THAN AN HOURS TIME. COVERAGE MAY STILL BE FAIRLY LOCALIZED...ESPECIALLY WITH THE FAIRLY NARROW LINEAR STRUCTURE OF NEWLY DEVELOPING STORMS. AREAS TO THE NORTH AND WEST OF THE AREAS OUTLINED ABOVE WILL LIKELY SEE ANOTHER BAND OF LIGHTER RAINFALL AND POSSIBLY SOME EMBEDDED THUNDER ARRIVE FOR THE EARLY EVENING BASED ON THE MOVEMENT OF CURRENT ACTIVITY TOWARDS PEORIA AND SPRINGFIELD. THE ADDITIONAL SHORTWAVES NOTED IN THE EARLY AFTERNOON DISCUSSION BELOW WILL ALSO BRING ADDITIONAL CHANCES FOR ADDITIONAL SHOWERS AND POSSIBLY A FEW STORMS INTO THE OVERNIGHT...WITH THE WESTERN EDGE OF THE COVERAGE GRADUALLY SHIFTING EAST WITH EACH WAVE. THE THUNDER THREAT WILL DIMINISH OVERALL THROUGH THE EVENING AND END ACROSS THE WESTERN CWA INTO THE OVERNIGHT. MDB //PREV DISCUSSION... 215 PM CDT LATE AFTERNOON AND EARLY EVENING...STORMS AND ASSOCIATED SEVERE POTENTIAL ARE THE INITIAL FOCUS WITH SHRA/TSRA COVERAGE OVERNIGHT THE SECOND FOCUS. SURFACE LOW PRESSURE REMAINS CENTERED OVER FAR EASTERN SOUTH DAKOTA WITH AN OCCLUDED FRONT ARCHING EAST THEN SOUTHEAST TO A VERY WEAK LOW CIRCULATION NORTHEAST OF DECORAH IOWA. A COLD FRONT THEN EXTENDS SOUTHWARD ACROSS THE QUAD CITIES BACK INTO CENTRAL MISSOURI AS NOTED BY THE SHARP DROP OFF IN DEWPOINTS. THERE IS ANOTHER TROUGH AHEAD OF THE FRONT WHICH MAY BE THE REMNANTS OF EARLIER OUTFLOW THAT MOVED ACROSS EASTERN MISSOURI. WATER VAPOR SHOWS SEVERAL UPPER SHORTWAVES MOVING NORTHEASTWARD AROUND THE EASTERN FLANK OF A BIG CLOSED UPPER LOW CENTERED OVER SOUTHEAST SOUTH DAKOTA. THE TRACK OF THESE WAVES WILL BE RIGHT ACROSS THE LOCAL AREA THROUGH TONIGHT. THE FIRST WAVE IS MOVING INTO EASTERN IOWA WITH ANOTHER WAVE OVER WEST CENTRAL MISSOURI. A THIRD WAVE IS MOVING ACROSS EASTERN OKLAHOMA AND WESTERN ARKANSAS. ADDITIONAL WAVES HAVE ALSO BEEN ROLLING NORTHEAST ACROSS THE LOWER OHIO VALLEY AND CENTRAL IL/IN. ALL OF THIS MAKES FOR A RATHER MESSY PRECIP SITUATION. CURRENT RADAR MOSAIC SHOWS SEVERAL CLUSTERS OF BETTER ORGANIZED CONVECTION MAINLY AFFECTING THE NORTHERN AND SOUTHEASTERN EXTENTS OF THE CWA TIED TO VARIOUS SHORTWAVES TRAVERSING THE UPPER FLOW. ADDITIONAL SPOTTY SHOWERS CONTINUE TO POP ACROSS THE CHICAGO METRO AREA WHERE STRATUS HAS BEEN ERODING AND INSTABILITY GROWING. THE NEXT WAVE COMING FROM EASTERN IOWA SEEMS TO BE DRIVING ANOTHER CLUSTER OF WEAKER BUT SLOWLY INTENSIFYING CONVECTION NEAR STERLING AND PERU. THE IMMEDIATE CONCERN IS THE MORE INTENSE STORMS MOVING INTO THE SOUTHEASTERN CWA AND THE WEAKER CLUSTER NEAR PERU/STERLING WHICH MAY INTENSIFY AS IT MOVES INTO THE CWA. WITH LOWEST CLOUDS ERODING SIGNALING EROSION OF EARLIER CAP ALONG WITH WARMING ATMOSPHERE IS BETTER PRIMED WITH MIXED LAYER CAPES AROUND 1500 J/KG. EFFECTIVE SHEAR HAS BEEN ABLE TO INTENSIFY BASED ON LATEST RAP ANALYSIS WITH AROUND 40 KT EXPECTED. STORMS THAT HAVE AFFECTED THE AREA THUS FAR HAVE EXHIBITED LOW AND MID LEVEL ROTATION THOUGH IT HAS BEEN WEAK. IT DOES APPEAR THAT COVERAGE WILL BEGIN TO EXPAND OUTSIDE AREAS THAT ARE CURRENTLY SEEING STORMS SO WILL CONTINUE TO MONITOR FOR SEVERE GIVEN THE SUPPORTIVE ATMOSPHERE. COVERAGE IS THE MAIN QUESTION HOWEVER...WITH OVERALL SEVERE THREAT STILL SEEMING ISOLATED-SCATTERED. THREATS REMAIN LARGE HAIL AND DAMAGING WIND GUSTS...WITH ISOLATED TORNADOES STILL POSSIBLE BUT AT THIS POINT WITH NORTHERN AREAS STILL FAVORED WITH LOCALLY BACKED FLOW A BETTER POSSIBILITY GIVEN THE WEAK LOW CIRCULATION JUST TO THE NORTHWEST...BUT HAVE SEEN SEVERAL SITES ACROSS THE CENTRAL AND EASTERN CWA BACK SLIGHTLY. VERY HIGH LOW LEVEL CAPE IS IN PLACE ACROSS MUCH OF THE AREA SO CANNOT DISCOUNT THE TORNADO THREAT ELSEWHERE. WITH PRECIPITABLE WATER VALUES OF 1.5-1.7+ INCHES HEAVY RAINFALL IS A CONCERN WITH ANY STRONGER STORMS. WITH RECENT DRY WEATHER AND UNCERTAINTY IN THE COVERAGE OF THE MOST INTENSE STORMS VS. LESS INTENSE BROADER RAIN/EMBEDDED THUNDER WILL HOLD OFF ON A FLASH FLOOD WATCH FOR NOW BUT CONTINUE TO MONITOR. TONIGHT...DURATION OF SEVERE POTENTIAL IS THE NEXT QUESTION. WITH THE FRONT VERY SLOWLY MOVING EASTWARD THE MOIST AIRMASS WILL REMAIN IN PLACE BUT SUNSET WILL LIKELY ALLOW INSTABILITY TO WANE SO SEVERE THREAT SHOULD BE DIMINISHING THROUGH THE EVENING. POPS HOWEVER LOOK TO REMAIN RATHER HIGH AS THE NEXT SEVERAL SHORTWAVES MOVE ACROSS. THUS EXPECT THAT THERE WILL BE A FEW MORE ROUNDS OF SHOWERS AND STORMS TO AFFECT THE AREA...WITH THE THUNDER THREAT DIMINISHING ACROSS THE WESTERN CWA AS THE FRONT APPROACHES. WILL NEED TO HANG ONTO POPS THROUGH MUCH OF THE NIGHT ACROSS THE EASTERN HALF OR SO OF THE CWA...NAMELY BECAUSE THE OK/AR WAVE IS EXPECTED TO ARRIVE AFTER MIDNIGHT BRINGING MORE SHRA/TSRA WITH IT. ULTIMATELY...POPS WILL DECREASE FROM WEST TO EAST OVERNIGHT...WITH A QUICKER EASTWARD PROGRESSION TOWARD DAYBREAK. DRIER AIR WILL BEGIN TO WORK INTO THE WEST WITH DEWPOINTS FALLING INTO THE 40S WEST AND 50S EAST OVERNIGHT. MDB SUNDAY THROUGH NEXT SATURDAY... LINGERING UPPER LEVEL CUT OFF LOW AND ASSOCIATED INSTABILITY SHOWERS INITIALLY WILL BE REPLACED BY HIGH PRESSURE AND A GRADUAL WARMING TREND LATER IN THE WEEK LASTING INTO SATURDAY. UPPER LOW TO TRUDGE ACROSS NORTHERN IL LATER SUNDAY AND SUNDAY NIGHT.. AND INTO NW INDIANA MONDAY MORNING. MODELS APPEAR TO CONTINUE TO STRUGGLE WITH THIS PROGRESSION WITH BOTH MODEL TO MODEL AND RUN TO RUN INCONSISTENCIES. 12Z GFS SEEMS SOMEWHAT A MIDDLE GROUND BETWEEN THE SLOWER NAM/CANADIAN AND FASTER ECMWF AND WILL TREND IN THIS DIRECTION WITH DETERMINISTIC FORECAST/GRIDS. THE MOST SIGNIFICANT WEATHER ELEMENT HAVING BEARING ON THE DEPARTURE SPEED OF THE UPPER LOW IS LIKELY THE DURATION OF THE CHANCE OF INSTABILITY SHOWERS ASSOCIATED WITH THE THERMAL TROUGH AND STEEPER LAPSE RATES WITH AND IN THE WAKE OF THE LOW. MIDDLE GROUND APPROACH WOULD HAVE INSTABILITY SHOWERS ENDING BY ABOUT DUSK MONDAY...BUT SHOULD A SLOWER SOLUTION LIKE THE NAM/CANADIAN VERIFY...WE COULD SEE ISOLATED SHOWERS LINGERING INTO TUESDAY. EVENING AND OVERNIGHT FORECAST SHIFTS WILL MONITOR AND ADJUST ACCORDINGLY. INITIAL RESIDUAL MOISTURE/LOW CLOUDS AND WIDELY SCT SHOWERS IN THE WAKE OF THE FRONT WILL EXIT EASTERN ILLINOIS AND NW INDIANA SUNDAY MORNING AS DRY SLOT PUNCHES INTO THE AREA FROM THE SW. GIVEN DRYING SW SFC FLOW EXPECT VARIABLE CONDITIONS SUNDAY WITH A FAIR AMOUNT OF SUNSHINE FOR A PERIOD AT MOST LOCATIONS AND DESPITE PASSAGE OF A COLD FRONT MAX TEMPS WILL STILL BE NEAR TO ONLY A FEW DEGREES BELOW SEASONAL NORMS. DEPENDING ON AFOREMENTIONED TIMING OF UPPER LOW... MAY SEE WIDELY SCATTERED INSTABILITY SHOWERS DEVELOP WEST OF I-39 LATE IN THE DAY. UPPER LEVEL THERMAL TROUGH TRAVERSES THE AREA EARLY MONDAY. GIVEN THE PRESENCE OF LIMITED MOISTURE... AND THIS OUT OF PHASE TIMING OF THE UPPER THERMAL TROUGH WITH THE MIN/MAX DIURNAL HEATING OF THE DAY... FEEL COVERAGE OF INSTABILITY SHOWERS ON MONDAY WILL BE SOMEWHAT LIMITED AND WILL CONTINUE TO PLAY LOW POPS FOR THAT EVENT. INCREASED CLOUDINESS ON MONDAY WILL LIMIT MAX TEMPS TO LOWER 60S.. WITH PERHAPS A FEW AREAS STAYING IN THE UPPER 50S. UPPER LEVEL HEIGHTS RISE RATHER ABRUPTLY IN THE WAKE OF THE UPPER CUT OFF LOW TUESDAY AS A PROGRESSIVE UPPER LEVEL RIDGE BUILDS EAST ACROSS THE PLAINS AND INTO THE WESTERN GREAT LAKES TUESDAY NIGHT INTO WEDNESDAY. THIS ALLOWS FOR ABUNDANT SUNSHINE AND MILDER TEMPS TO RETURN TO THE AREA ON TUESDAY... AND BE THE START OF A GRADUAL WARMING TREND THAT WILL LAST THROUGH THE REST OF THE WEEK. SPRAWLING HIGH PRESSURE WILL HELP ENABLE MOSTLY SUNNY MILD DAYS AND MOSTLY CLEAR...COOL...AND CRISP NIGHTS MID TO LATE WEEK. WITH THE HIGH SLIDING TO JUST EAST OF THE AREA THURS-SAT...AN EXTENDED PERIOD OF WEAK SOUTHERLY FLOW WILL ALLOW FOR TEMPS TO RETURN TO ABOVE SEASONAL AVERAGES AND ANOTHER STRETCH OF DELIGHTFUL AUTUMN WEATHER. THE NEXT CHANCE OF RAIN WILL THEN COME LATE SATURDAY OR SUNDAY. ED F && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 00Z... * LINGERING SHOWERS OVER THE NEXT SEVERAL HOURS...WITH A POSSIBILITY FOR ISOLATED SHOWERS ONCE AGAIN LATE IN THE FORECAST PERIOD. * VFR CEILINGS...WITH A CHANCE FOR BRIEF MVFR CEILINGS OVERNIGHT. RODRIGUEZ //DISCUSSION...UPDATED 00Z... THE BULK OF THE SHOWERS AND THUNDERSTORMS HAVE EXITED THE TERMINALS THIS HOUR...WITH SOME LINGERING DEVELOPMENT STILL ONGOING ACROSS THE MDW/GYY AREA. EXPECT THIS TO ALSO EXIT WITH ONLY ISOL/SCT SHOWER DEVELOPMENT OVER THE NEXT SEVERAL HOURS...WITH DRIER CONDITIONS EXPECTED OVERNIGHT INTO SUNDAY. ALTHOUGH THERE IS THE POSSIBILITY FOR SHOWERS ONCE AGAIN SUNDAY AFTERNOON...HAVE OPTED TO LEAVE OUT OF THE TAFS AT THIS TIME. VFR CONDITIONS WILL PREVAIL TONIGHT INTO SUNDAY WITH A BRIEF 1-2 HOUR WINDOW AROUND THE 6Z TIME FRAME TONIGHT WHEN MVFR CEILINGS AROUND 2KFT COULD MOVE ACROSS THE TERMINALS. CONFIDENCE IS LOW WITH THIS POSSIBILITY...BUT CONFIDENCE HIGHER WITH REGARD TO THE BRIEF NATURE OF THESE LOWER CEILINGS. CLEARING SHOULD OCCUR EARLY SUNDAY MORNING...BUT WITH SOME BRIEF VFR CEILINGS REDEVELOPING ONCE AGAIN SUNDAY AFTERNOON. SOUTH SOUTHEAST WINDS WILL SLOWLY BECOME MORE SOUTH SOUTHWEST EVENTUALLY TURNING SOUTHWEST AND INCREASING SLIGHTLY IN SPEEDS OVERNIGHT WITH FROPA...AND REMAINING SOUTHWEST THROUGH THE REMAINDER OF THE FORECAST PERIOD. RODRIGUEZ //ORD AND MDW CONFIDENCE...UPDATED 00Z... * HIGH CONFIDENCE WITH SHOWER TRENDS IN THE NEAR TERM. * HIGH CONFIDENCE WITH VFR CEILINGS...LOW CONFIDENCE WITH MVFR POTENTIAL OVERNIGHT. RODRIGUEZ //OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z... MONDAY...CHANCE OF SHRA...OTHERWISE VFR. TUESDAY...VFR. WEDNESDAY...VFR. THURSDAY...VFR. FRIDAY...VFR. RODRIGUEZ && .MARINE... 1228 PM CDT LOW PRESSURE WAS OVER EASTERN SOUTH DAKOTA THIS AFTERNOON WITH A WITH AN OCCLUDED FRONT INTO WISCONSIN AND A COLD FRONT EXTENDING SOUTH THROUGH ILLINOIS. THE COLD FRONT WILL MOVE THROUGH SOUTH AND CENTRAL LAKE MICHIGAN TONIGHT WITH PERIODS OF SHOWERS AND THUNDERSTORMS. THIS WILL TURN WINDS FROM SOUTH TO SOUTHWEST. STRONG EASTERLY FLOW WILL CONTINUE NORTH OF THE FRONT OVER NORTHERN LAKE MICHIGAN. THE FRONT WILL FINALLY REACH NORTHERN LAKE MICHIGAN SUNDAY AS THE LOW MOVES TO EASTERN LAKE SUPERIOR. THIS WILL ALLOW WINDS TO DIMINISH AND SHIFT SOUTH TO SOUTHWEST OVER THE NORTH END OF THE LAKE. THE LOW WILL CONTINUE TO LIFT NORTHEAST INTO EASTERN ONTARIO SUNDAY NIGHT AND MONDAY BUT A WEAK TROF OF LOW PRESSURE WILL REMAIN OVER LAKE MICHIGAN. AS THE TROF PASSES...WINDS WILL SHIFT TO NORTHWEST AND INCREASE MONDAY AFTERNOON. HIGH PRESSURE WILL GRADUALLY BUILD INTO THE WESTERN GREAT LAKES MONDAY NIGHT AND TUESDAY MORNING CAUSING WINDS TO BECOME LIGHT AND VARIABLE. SOUTHERLY FLOW WILL RETURN TO LAKE MICHIGAN FOR AN EXTENDED PERIOD FROM WEDNESDAY THROUGH THE END OF THE WEEK. ALLSOPP && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
103 AM CDT FRI OCT 4 2013 .DISCUSSION... 854 PM CDT FOR EVENING UPDATE... CONVECTIVE COMPLEX NUMBER TWO AFFECTING CENTRAL AND SOUTHERN PARTS OF THE WFO LOT CWA THIS EVENING. MCV EMBEDDED WITHIN SHORT WAVE TROUGH INDICATED IN RADAR IMAGERY JUST EAST OF STREATOR. SEVERAL STRONG CELLS HAVE DEVELOPED OVER THE PAST HOUR NORTH-NORTHEAST OF THE CIRCULATION CENTER INTO NORTHEAST IL. THESE APPEAR TO BE FORMING IN WARM ADVECTION REGION OF MCV CIRCULATION...IN A REGION OF SLIGHTLY STRONGER EFFECTIVE DEEP BULK SHEAR THAN ARE THE NORTH-SOUTH ORIENTED LINE OF STORMS FARTHER SOUTH. DESPITE SOME COOLING OF THE NOCTURNAL BOUNDARY LAYER...CONTINUE TO SEE SOME VELOCITY SIGNATURES ASSOCIATED WITH WET MICROBURSTS...WITH REPORTS OF 40-45 MPH WIND RECENTLY NEAR PLAINFIELD. WOULD EXPECT THESE STORMS TO CONTINUE TO PUSH EAST-NORTHEAST ACROSS AREAS EAST OF THE FOX RIVER/I-55 THROUGH ABOUT 10-11 PM CDT. STRONGER CELLS MAY PRODUCE BRIEF 40-50 MPH GUSTS AND PERHAPS SOME PENNY-QUARTER SIZE HAIL...IN ADDITION TO BRIEF HEAVY RAINFALL. ATTENTION THEN TURNS TO THE WEST OVER IA...WHERE ADDITIONAL THUNDERSTORMS WERE DEVELOPING AHEAD OF ANOTHER SHORT WAVE TROUGH OVER EASTERN NEBRASKA/WESTERN IOWA. GUIDANCE DEPICTS THIS ACTIVITY SHOULD SPREAD NORTHEAST AS SOUTHWEST LOW LEVEL JET INCREASES OVERNIGHT...SPREADING INTO NORTHWESTERN PORTIONS OF THE CWA PRE-DAWN FRIDAY MORNING. RECENT HRRR HIGH-RES CONVECTION ALLOWING SOLUTION BREAKS OUT ADDITIONAL CONVECTION AFTER MIDNIGHT ACROSS WESTERN CWA...THOUGH THE STRONGEST MOISTURE TRANSPORT APPEARS TO FOCUS ACROSS THE NORTHWEST. HAVE ADJUSTED POP GRIDS TO ADD DETAIL WITH CURRENT ACTIVITY ACROSS THE CENTRAL/EASTERN PARTS OF THE CWA...AND HAVE BOOSTED POPS A BIT NORTHWEST DURING THE LATE NIGHT HOURS. RATZER //PREV DISCUSSION... 303 PM CDT SYNOPSIS...UNSETTLED WEATHER IS EXPECTED THROUGH THIS WEEKEND...BUT A DRY WARMING TREND IS EXPECTED NEXT WEEK. REST OF DAY AND TONIGHT... A LOW PRESSURE TROUGH EXTENDS FROM THE PLAINS INTO SW WI WITH A STATIONARY/WARM FRONT OVER SOUTHERN WI. A SHORTWAVE TROUGH IS ALSO OVER MN/WI AND THE SHORTWAVE WILL PASS OVER IL LATER THIS AFTN. THE STRONGEST PART OF THE SHORTWAVE AND SUBSEQUENT FORCING WILL STAY NORTH OF THE CWA AND PASS OVER CENTRAL/SOUTHERN WI. EXPECTING THE MAJORITY OF PRECIP TO STAY OVER WI CLOSER TO THE FORCING. HOWEVER GIVEN RECENT RADAR TRENDS...THINKING THE NAM MAY BE ON TO SOMETHING WITH MEASURABLE PRECIP ACROSS THE CWA LATE THIS AFTN THROUGH THIS EVENING. THE HRRR WOULD ALSO SUPPORT THIS THEORY AS WELL...THEREFORE PUT A LINE OF SHRA/TSRA MOVING THROUGH NORTHERN IL AND INDIANA IN THE GRIDS. OVERTIME HAVE THE SOUTHERN EXTENT OF THE LINE...SOUTH OF I-80...WEAKENING. THE SHOWERS AND THUNDERSTORMS WILL CONTINUE TO LIFT NORTH OVERNIGHT WITH THE WARM FRONT. FOR SVR POTENTIAL...THINKING A COUPLE OF STORMS MAY PULSE UP TO STRONG OR SVR...BUT OVERALL JUST EXPECTING GENERAL THUNDERSTORMS. MOISTURE IS PLENTIFUL WITH DEWPOINTS AROUND 70 AND PWAT VALUES AROUND 1.5 INCHES...2 STANDARD DEVIATIONS ABOVE NORMAL FOR OCTOBER. SFC CAPE VALUES ARE 1000-2500 J/KG WITH 30 KT OF SHEAR. FORECAST SOUNDINGS FEATURE SKINNY CAPE SO NOT EXPECTING LARGE HAIL...BUT A WIND THREAT IS CERTAINLY POSSIBLE. SOME OF THE CELLS HAVE ALREADY FEATURE BOW-ESQ CHARACTERISTICS. THEREFORE THINKING THE MAIN THREATS WILL BE HEAVY RAIN AND GUSTY WINDS. KEPT TEMPS A BIT WARMER TONIGHT AS THICK STRATUS SHOULD BE PLENTIFUL. LOOKING AT LOW TEMPS IN THE MID 60S. WITH DEWPOINTS IN THE MID 60S AS WELL...EXPECTING AREAS OF FOG AND POSSIBLE DENSE FOG AGAIN AFTER MIDNIGHT THROUGH EARLY FRIDAY MORNING. FRIDAY AND SATURDAY... A STRONG SURFACE LOW EJECTS OUT OF THE ROCKIES TOMORROW AND PASSES TO OUR NW THROUGH WI SATURDAY NIGHT. GUIDANCE STILL DIFFERS ON HOW FAST THE LOW WILL PASS THROUGH THE REGION...BUT IN GENERAL EXPECTING THE COLD FRONT TO IMPACT THE CWA SATURDAY AND SATURDAY NIGHT. FOR FRIDAY...EXPECTING A PRIMARILY DRY DAY BUT COULD SEE A FEW SHOWERS AND/OR STORMS ALONG THE IL/WI BORDER AS THE WARM FRONT SHIFTS NORTH. ANOTHER HOT AND MUGGY DAY WITH HIGHS IN THE MID TO UPPER 80S AND DEWPOINTS IN THE MID 60S. THERE IS A CONCERN SIMILAR TO TODAY THAT IF THE STRATUS LINGERS TOO LONG...TEMPS COULD BE COOLER THAN FORECAST. HOWEVER THE FRONT WILL START OUT FARTHER NORTH TOMORROW AND THERE WILL BE BETTER MIXING...SO THINKING THE STRATUS WILL BURN OFF FASTER THAN THIS MORNING. SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH FORECAST CAPE VALUES OF 1000-1500 J/KG AND PWAT VALUES 1.5-1.75 INCHES. 0-6 KM SHEAR LOOKS FAVORABLE FOR SEVERE WEATHER WITH VALUES OF 35-40 KT AHEAD OF THE FRONT AND 50-70 KT ALONG THE FRONT. TIMING IS ALSO FAVORABLE AS INSTABILITY CAN GROW ACROSS THE REGION BEFORE THE FRONT SLIDES ACROSS. EXPECTING THE STRONGER STORMS AND PRECIP TO FALL ONCE AGAIN OVER WI AS THE UPPER LEVEL JETS LEFT EXIT REGION WILL PROVIDE ADDITIONAL LIFT. EXTENDED...SUNDAY THROUGH WEDNESDAY... THE UPPER LEVEL LOW PASSES OVER THE REGION LATE THIS WEEKEND AS THE SURFACE LOW LIFTS NORTHEAST INTO QUEBEC. UPPER LEVEL RIDGING AND A SURFACE HIGH MOVE OVER THE CWA BEFORE CONTINUING EAST AND REACHING THE ATLANTIC COAST BY MID WEEK. THE SURFACE LOW WILL PASS OVER NORTHERN LAKE MI SUNDAY WITH WRAP AROUND SHOWERS POSSIBLE SUNDAY NIGHT/MONDAY MORNING. GUIDANCE DOES DIFFER ON HOW QUICKLY THE LOW SHIFTS TO THE NE...AND THE SOUTHERN EXTENT OF THE WRAP AROUND SHOWERS WILL DEPEND ON THE TRACK OF THE LOW. THE END OF THE WEEKEND WILL BE COOL BUT A GRADUAL WARM UP TO ABOVE NORMAL TEMPS IS EXPECTED THROUGH MID NEXT WEEK AS THE HIGH BUILDS IN. JEE && .AVIATION... //ORD AND MDW CONCERNS...UPDATED 06Z... * PSBL VCTS ARRIVING AFT 07Z THRU 09Z. * PATCHY MVFR CIGS DEVELOPING THRU DAYBREAK. * SOUTHWEST WINDS BACKING SOUTHEAST THIS AFTN...SPEEDS INCREASING TO ARND 10KT AND OCCASIONAL GUSTS TO 18KT THIS AFTN. BEACHLER //DISCUSSION...UPDATED 06Z... IR IMAGERY EARLY THIS MORNING SHOWS A COMPLEX OF SHOWERS/THUNDERSTORMS DEVELOPING OVER CENTRAL/WESTERN IOWA...WITH A WARM FRONTAL BOUNDARY EXTENDING EAST THROUGH SOUTHERN WISCONSIN. IT IS LIKELY THAT THIS COMPLEX OF THUNDERSTORMS WILL CONTINUE TO SLIDE EAST/NORTHEAST ALONG THIS BOUNDARY. A FEW ISOLATED THUNDERSTORMS HAVE DEVELOPED OVER NORTHWEST IL...AND MAY ARRIVE NEAR RFD/DPA/ORD/MDW BTWN 07-11Z...THEN SHOULD LIFT NORTHEAST OF TAF SITES. THERE IS ALSO SOME INDICATION THAT PATCHY MVFR CIGS MAY DEVELOP...AND EVEN ISOLATED AREAS OF IFR CIGS. ALTHOUGH FEEL THAT WITH THE SOUTHERLY FLOW CURRENTLY GOING ON AND JUST ENOUGH WIND TO KEEP THINGS MIXING AT THE SFC...THAT IF CIGS AND VSBYS DO REDUCE THEY SHOULD NOT BE TOO LOW. SO HAVE BROUGHT CIGS UP SLIGHTLY...WHICH SEEMS TO MATCH UP WITH WHAT IS GOING ON TO THE WEST/SOUTHWEST OF THE REGION. GUIDANCE HAS BEEN INDICATING THAT AS THE COMPLEX OF THUNDERSTORMS SLIDES NORTHEAST THAT IT MAY HELP PUSH THE FRONTAL BOUNDARY BACK SOUTH ACROSS NORTHERN IL/NORTHWEST IN AIRFIELDS MIDDAY/EARLY AFTN. IF THIS OCCURS WINDS WILL BACK FURTHER TO THE SOUTHEAST AND POSSIBLY TO THE EAST ACROSS FAR NORTHEAST IL. THE GRADIENT DOES INCREASE MIDDAY AND HAVE HELD ONTO MENTION OF OCCASIONAL GUSTS INTO THE MID TEENS. AT THIS TIME IT DOES APPEAR THE BULK OF TODAY WILL REMAIN VFR WITH A DRY FORECAST...HOWEVER AN ISOLATED SHOWER/THUNDERSTORM CANNOT BE RULED OUT BY LATE THIS AFTN/EVENING. BEACHLER //ORD AND MDW CONFIDENCE...UPDATED 06Z... * MEDIUM CONFIDENCE IN VCTS TIMING AND COVERAGE. * MEDIUM CONFIDENCE IN CIGS/VSBY FORECAST IN CURRENT TAF. * MEDIUM/HIGH CONFIDENCE IN WIND DIR/SPEED FORECAST. * MEDIUM/HIGH CONFIDENCE IN TSRA THIS AFT HOLDING OFF UNTIL AFT 21Z. BEACHLER //OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z... SATURDAY...TSRA LIKELY. SUNDAY...CHC OF SHRA. MONDAY-WEDNESDAY...VFR. DZ && .MARINE... 324 PM CDT LOW PRESSURE SITTING ON THE MN-IA BORDER AT MID AFTERNOON WILL MOVE ENE ALONG A STATIONARY FRONT DRAPED ACROSS CENTRAL LAKE MI TONIGHT...WITH THE LOW REACHING CENTRAL LOWER MI BY DAWN. STRONG LOW PRESSURE WILL REMAIN IN THE CENTRAL HIGH PLAINS TONIGHT AND THEN MOVE NE FRI...REACHING SOUTHERN MN BY SAT MORNING. AS THIS LOW CONTINUES NE TO THE WESTERN U.P. OF MI SAT...AND THEN ACROSS LAKE SUPERIOR INTO ONTARIO SAT NIGHT IT WILL SWEEP A STRONG COLD FRONT ACROSS THE UPPER MIDWEST AND INTO THE UPPER GREAT LAKES. THIS LOW MOVES FURTHER OFF TO THE NE TOWARD SOUTHERN HUDSON BAY SUN AND SUN NIGHT. A STRONG S TO SW FLOW WILL PRECEDE THE PLAINS LOW AND ITS COLD FRONT...BUT DUE TO THE VERY WARM AIR IT WILL CONTINUE TO SPREAD ACROSS THE REGION IT WILL BE QUITE STABLE AT AND CLOSE TO THE SURFACE OF THE LAKE WHICH WILL PREVENT THE STRONGER WINDS FROM PENETRATING DOW TO NEAR THE LAKE SURFACE. HOWEVER...ONCE THE COLD FRONT PASSES W TO E ACROSS THE LAKE DURING LATER SAT AND SAT EVENING MUCH COOLER AIR WILL QUICKLY BE SWEPT ACROSS THE REGION. WITH THE STILL RELATIVELY WARM LAKE WATER AND THE LOW LEVEL COLD AIR ADVECTION BEHIND THE FRONT IT WILL TURN FROM A STABLE TO A VERY UNSTABLE CONDITION AT THE LAKE SURFACE...WHICH WILL ALLOW STRONG SW TO W WINDS BEHIND THE COLD FRONT AND IN THE WAKE OF THE DEPARTING LOW TO EFFICIENTLY MIX ALL THE WAY DOWN TO THE LAKE SURFACE. WHILE THERE MAY BE A LOW END GALE FORCE GUST OR TWO OBSERVED SATURDAY NIGHT AFTER THE COLD FRONTAL PASSAGE...BASED ON CURRENT MODEL GUIDANCE AN UPPER LIMIT OF 30KT SUSTAINED WINDS APPEARS TO BE THE APPROPRIATE FORECAST. MODELS GENERALLY AGREE IN MOVING THE LOW QUICKLY TO THE NE AND NNE ACROSS ONTARIO TO NEAR SOUTHERN HUDSON BAY BY SUNDAY NIGHT...THE GRADIENT ACROSS LAKE MI WILL BE RELAXING DURING THE DAY SUN...WITH A CORRESPONDING GRADUAL DECREASE IN WIND SPEEDS OCCURRING AS THE DAY PROGRESSES. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... IL...NONE. IN...NONE. LM...NONE. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
434 PM EDT FRI OCT 4 2013 .SYNOPSIS... ISSUED AT 434 PM EDT FRI OCT 4 2013 A WARM AND MOIST AIRMASS WILL REMAIN OVER THE REGION INTO THE WEEKEND. PERIODIC SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS EVENING THROUGH LATE SATURDAY NIGHT WHEN A COLD FRONT APPROACHES THE AREA FROM THE WEST. WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE WITH HIGHS IN THE LOW 80S AND LOWS IN THE MID 60S. && .UPDATE... ISSUED AT 113 PM EDT FRI OCT 4 2013 GRID UPDATE EARLY THIS AFTERNOON TO ACCOUNT FOR DEVELOPMENT OF SCT SHOWERS AND THUNDERSTORMS. BREAKS IN CLOUD COVER LATE THIS MORNING AND EARLY AFTERNOON HAVE ALLOWED FOR TEMPERATURES TO QUICKLY WARM INTO THE UPPER 70S TO LOW 80S IN MOST LOCATIONS. SCT SHOWERS POPPING UP AS CONVECTIVE TEMPS REACHED WITH SB CAPE VALUES EXCEEDING 1000 J/KG. LATEST HRRR AND RAP RUNS HAVE CAPTURED THIS DECENTLY AND SUSPECT THIS ACTIVITY WILL CONTINUE INTO THE EVENING HOURS. THEREFORE HAVE ADDED SCT TSRA ACROSS ENTIRE AREA THRU 00Z. ONLY MINOR CHANGES MADE TO TEMPS AND SKY COVER GRIDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM EDT FRI OCT 4 2013 LEE CYCLOGENESIS IS NOW WELL UNDERWAY ACROSS THE CENTRAL PLAINS AS 100+ KT JET ROUNDS THE BASE OF LONGWAVE TROUGH PRESENTLY OVER THE ROCKIES. ASSOCIATED VORT MAX IS VERY IMPRESSIVE WITH A CLASSIC TREBLE CLEF SIGNATURE DEVELOPING ON THE 1.5 PVU SURFACE TODAY...AND THE MAIN PV LOBE EXTENDING THROUGH MOST OF THE TROPOSPHERE. THIS STRONG PV ADVECTION WILL COMBINE WITH GOOD DIFFLUENCE ALOFT AND SOME SEMBLANCE OF A COUPLED UPPER JET STRUCTURE TO SUPPORT CONTINUED STRENGTHENING OF THE CENTRAL PLAINS SURFACE LOW. WHAT THIS MEANS LOCALLY IS THAT SOUTHWEST FLOW/THETA-E ADVECTION WILL PERSIST THROUGH THE SHORT TERM WITH A LITANY OF CONVECTIVELY ENHANCED SHORTWAVES CONTINUING TO IMPACT THE SOUTHERN GREAT LAKES. SURFACE WARM FRONT WILL REMAIN DRAPED JUST TO OUR NORTH AND SUBTLE HEIGHT RISES DOWNSTREAM OF APPROACHING TROUGH SHOULD KEEP THE BULK OF OUR AREA DRY TODAY AS THE FOCUS OF CONVECTION REMAINS IN LOWER MICHIGAN. CONFIDENCE IN THIS SCENARIO REMAINS LOW HOWEVER GIVEN WEAK/BROAD 300-305K ISENTROPIC ASCENT AND VERY LITTLE CONVECTIVE INHIBITION ON NEWEST NAM AND GFS BUFR SOUNDINGS. NOTHING IN THE LATEST RADAR IMAGERY OR HI-RES GUIDANCE TO SUPPORT ALTERING DRY FORECAST AFTER REMAINING SHOWERS EXIT AROUND 12Z...BUT WILL HAVE TO KEEP AN EYE ON THIS THROUGHOUT THE DAY AS AN ISOLATED SHOWERS/STORM IS CERTAINLY NOT OUTSIDE THE REALM OF POSSIBILITY. THIS WILL BE ESPECIALLY TRUE IN OUR FAR NORTHERN COUNTIES...CLOSER TO THE SURFACE WARM FRONT AND EXPECTED TRAIN OF W-E ORIENTED CONVECTIVE CLUSTERS. CONFIDENCE IN HIGH TEMP FORECAST IS SIMILARLY LOW. ANY SUSTAINED BREAKS IN CLOUD COVER COULD ALLOW HIGHS TO SURGE WELL INTO THE MID 80S GIVEN 850MB TEMPS AROUND 16C. EXPECT THERE WILL STILL BE A FAIR AMOUNT OF CLOUDS IN THE AFTERNOON THOUGH AND WILL MAINTAIN HIGHS IN THE LOW TO MID 80S. LITTLE CHANGES DURING THE OVERNIGHT PERIOD AS WE REMAIN IN A REGION OF BROAD WARM/MOIST AIR ADVECTION. LACK OF CLEAR FORCING MECHANISM AT THIS POINT WARRANTS JUST A LOW CHANCE OF POPS. LOWS WILL BE VERY MILD...LIKELY NOT DROPPING MUCH BELOW THE UPPER 60S IN THIS VERY MOIST ENVIRONMENT. COULD ALSO BE A FEW AREAS OF FOG OVERNIGHT GIVEN POOLING MOISTURE AND LIGHT SURFACE WINDS BENEATH A STRENGTHENING INVERSION. MAV AND MET GUIDANCE BOTH SUPPORT PERIODS OF FOG BUT WITH THE FRONT NORTH OF HERE AND VERY LITTLE FOG THIS MORNING...WILL LEAVE OUT MENTION FOR NOW AND LET LATER SHIFT MODIFY AS NECESSARY. && .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 342 AM EDT FRI OCT 4 2013 VRY INTENSE SW TROUGH AND ATTENDANT UPR JET STREAK CARVING OUT AN IMPRESSIVE CYCLONE ACRS THE CNTRL ROCKIES THIS MORNING. SFC LOW CNTRD OVR SE CO WILL LIFT NEWD AND OCCLUDE INTO SAT MORNING ACRS SERN SD AND YIELD A SLW EWD EJECTION OF SFC OCCLUSION. BROAD/MOIST WARM SECTOR WILL PERSIST EWD ACRS THE LAKES/OH VALLEY YET W/MINIMAL BACKGROUND FOCUS. THUS KEPT W/A MINIMIZED LOWER BLENDED POP THROUGH SAT AFTN. CONTD EWD PROGRESSION OF OCCLUDED FNT LT SAT NIGHT WILL BRING ABT A PD OF SHRA/TSRA AND LIKELY LINGER ACRS ERN ZONES THROUGH SUN AFTN. OTRWS STG NEG THETA-E ADVTN SHLD WRAP QUICKLY EWD SWD OF MID LVL CYCLONE SUN NIGHT. SFC RIDGING AND FLATTENING FLW ALOFT FOLLOW IN WAKE OF THIS SYS FOR MID PD W/ABV NORMAL TEMPS DVLPG LT PD IN RESPONSE TO RENEWED DEEP WRN TROUGHING TWD DYS 6-7. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 140 PM EDT FRI OCT 4 2013 ABUNDANT MOISTURE...MODEST INSTABILITY AND A SUBTLE SHORT WAVE COMBINED WITH TRIGGER TEMPERATURES IN THE LOWER 80S HAVE LED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EARLY THIS AFTERNOON. SLIGHTLY BETTER INSTABILITY TOWARD KFWA SO INCLUDED A TEMPO TSRA THERE COUPLED WITH RADAR TRENDS. WEAKER RETURNS TOWARD KSBN SO KEPT THIS AS JUST A SHRA. REMAINDER OF FORECAST LATER THIS AFTERNOON AND TONIGHT REMAIN UNCERTAIN FOR MANY REASONS. CONTINUED UNSTABLE AND MOISTURE RICH ATMOSPHERE COULD ALLOW SHRA/TSRA TO DEVELOP THROUGH THE PERIOD. BUT NO STRONG FORCING MAKES TIMING ANY PCPN AT TAF SITES NEARLY IMPOSSIBLE. THEREFORE LEFT MENTION OUT AFTER THIS AFTERNOON. FOG AND STRATUS ONCE AGAIN POSSIBLE OVERNIGHT BUT LIKE THIS MORNING COULD BE HINDERED BY ANY CONVECTION AND LINGERING HIGHER CLOUDS. KEPT A MVFR GROUP IN FOR NOW AND WILL WAIT TO SEE HOW THINGS DEVELOP. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...CEO SYNOPSIS...CEO/KG SHORT TERM...AGD LONG TERM...T AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
141 PM EDT FRI OCT 4 2013 .SYNOPSIS... ISSUED AT 113 PM EDT FRI OCT 4 2013 A WARM AND MOIST AIRMASS WILL REMAIN OVER THE REGION INTO THE WEEKEND. PERIODIC SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON THROUGH LATE SATURDAY NIGHT WHEN A COLD FRONT APPROACHES THE AREA FROM THE WEST. WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE WITH HIGHS IN THE LOW 80S AND LOWS IN THE MID 60S. && .UPDATE... ISSUED AT 113 PM EDT FRI OCT 4 2013 GRID UPDATE EARLY THIS AFTERNOON TO ACCOUNT FOR DEVELOPMENT OF SCT SHOWERS AND THUNDERSTORMS. BREAKS IN CLOUD COVER LATE THIS MORNING AND EARLY AFTERNOON HAVE ALLOWED FOR TEMPERATURES TO QUICKLY WARM INTO THE UPPER 70S TO LOW 80S IN MOST LOCATIONS. SCT SHOWERS POPPING UP AS CONVECTIVE TEMPS REACHED WITH SB CAPE VALUES EXCEEDING 1000 J/KG. LATEST HRRR AND RAP RUNS HAVE CAPTURED THIS DECENTLY AND SUSPECT THIS ACTIVITY WILL CONTINUE INTO THE EVENING HOURS. THEREFORE HAVE ADDED SCT TSRA ACROSS ENTIRE AREA THRU 00Z. ONLY MINOR CHANGES MADE TO TEMPS AND SKY COVER GRIDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM EDT FRI OCT 4 2013 LEE CYCLOGENESIS IS NOW WELL UNDERWAY ACROSS THE CENTRAL PLAINS AS 100+ KT JET ROUNDS THE BASE OF LONGWAVE TROUGH PRESENTLY OVER THE ROCKIES. ASSOCIATED VORT MAX IS VERY IMPRESSIVE WITH A CLASSIC TREBLE CLEF SIGNATURE DEVELOPING ON THE 1.5 PVU SURFACE TODAY...AND THE MAIN PV LOBE EXTENDING THROUGH MOST OF THE TROPOSPHERE. THIS STRONG PV ADVECTION WILL COMBINE WITH GOOD DIFFLUENCE ALOFT AND SOME SEMBLANCE OF A COUPLED UPPER JET STRUCTURE TO SUPPORT CONTINUED STRENGTHENING OF THE CENTRAL PLAINS SURFACE LOW. WHAT THIS MEANS LOCALLY IS THAT SOUTHWEST FLOW/THETA-E ADVECTION WILL PERSIST THROUGH THE SHORT TERM WITH A LITANY OF CONVECTIVELY ENHANCED SHORTWAVES CONTINUING TO IMPACT THE SOUTHERN GREAT LAKES. SURFACE WARM FRONT WILL REMAIN DRAPED JUST TO OUR NORTH AND SUBTLE HEIGHT RISES DOWNSTREAM OF APPROACHING TROUGH SHOULD KEEP THE BULK OF OUR AREA DRY TODAY AS THE FOCUS OF CONVECTION REMAINS IN LOWER MICHIGAN. CONFIDENCE IN THIS SCENARIO REMAINS LOW HOWEVER GIVEN WEAK/BROAD 300-305K ISENTROPIC ASCENT AND VERY LITTLE CONVECTIVE INHIBITION ON NEWEST NAM AND GFS BUFR SOUNDINGS. NOTHING IN THE LATEST RADAR IMAGERY OR HI-RES GUIDANCE TO SUPPORT ALTERING DRY FORECAST AFTER REMAINING SHOWERS EXIT AROUND 12Z...BUT WILL HAVE TO KEEP AN EYE ON THIS THROUGHOUT THE DAY AS AN ISOLATED SHOWERS/STORM IS CERTAINLY NOT OUTSIDE THE REALM OF POSSIBILITY. THIS WILL BE ESPECIALLY TRUE IN OUR FAR NORTHERN COUNTIES...CLOSER TO THE SURFACE WARM FRONT AND EXPECTED TRAIN OF W-E ORIENTED CONVECTIVE CLUSTERS. CONFIDENCE IN HIGH TEMP FORECAST IS SIMILARLY LOW. ANY SUSTAINED BREAKS IN CLOUD COVER COULD ALLOW HIGHS TO SURGE WELL INTO THE MID 80S GIVEN 850MB TEMPS AROUND 16C. EXPECT THERE WILL STILL BE A FAIR AMOUNT OF CLOUDS IN THE AFTERNOON THOUGH AND WILL MAINTAIN HIGHS IN THE LOW TO MID 80S. LITTLE CHANGES DURING THE OVERNIGHT PERIOD AS WE REMAIN IN A REGION OF BROAD WARM/MOIST AIR ADVECTION. LACK OF CLEAR FORCING MECHANISM AT THIS POINT WARRANTS JUST A LOW CHANCE OF POPS. LOWS WILL BE VERY MILD...LIKELY NOT DROPPING MUCH BELOW THE UPPER 60S IN THIS VERY MOIST ENVIRONMENT. COULD ALSO BE A FEW AREAS OF FOG OVERNIGHT GIVEN POOLING MOISTURE AND LIGHT SURFACE WINDS BENEATH A STRENGTHENING INVERSION. MAV AND MET GUIDANCE BOTH SUPPORT PERIODS OF FOG BUT WITH THE FRONT NORTH OF HERE AND VERY LITTLE FOG THIS MORNING...WILL LEAVE OUT MENTION FOR NOW AND LET LATER SHIFT MODIFY AS NECESSARY. && .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 342 AM EDT FRI OCT 4 2013 VRY INTENSE SW TROUGH AND ATTENDANT UPR JET STREAK CARVING OUT AN IMPRESSIVE CYCLONE ACRS THE CNTRL ROCKIES THIS MORNING. SFC LOW CNTRD OVR SE CO WILL LIFT NEWD AND OCCLUDE INTO SAT MORNING ACRS SERN SD AND YIELD A SLW EWD EJECTION OF SFC OCCLUSION. BROAD/MOIST WARM SECTOR WILL PERSIST EWD ACRS THE LAKES/OH VALLEY YET W/MINIMAL BACKGROUND FOCUS. THUS KEPT W/A MINIMIZED LOWER BLENDED POP THROUGH SAT AFTN. CONTD EWD PROGRESSION OF OCCLUDED FNT LT SAT NIGHT WILL BRING ABT A PD OF SHRA/TSRA AND LIKELY LINGER ACRS ERN ZONES THROUGH SUN AFTN. OTRWS STG NEG THETA-E ADVTN SHLD WRAP QUICKLY EWD SWD OF MID LVL CYCLONE SUN NIGHT. SFC RIDGING AND FLATTENING FLW ALOFT FOLLOW IN WAKE OF THIS SYS FOR MID PD W/ABV NORMAL TEMPS DVLPG LT PD IN RESPONSE TO RENEWED DEEP WRN TROUGHING TWD DYS 6-7. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 140 PM EDT FRI OCT 4 2013 ABUNDANT MOISTURE...MODEST INSTABILITY AND A SUBTLE SHORT WAVE COMBINED WITH TRIGGER TEMPERATURES IN THE LOWER 80S HAVE LED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EARLY THIS AFTERNOON. SLIGHTLY BETTER INSTABILITY TOWARD KFWA SO INCLUDED A TEMPO TSRA THERE COUPLED WITH RADAR TRENDS. WEAKER RETURNS TOWARD KSBN SO KEPT THIS AS JUST A SHRA. REMAINDER OF FORECAST LATER THIS AFTERNOON AND TONIGHT REMAIN UNCERTAIN FOR MANY REASONS. CONTINUED UNSTABLE AND MOISTURE RICH ATMOSPHERE COULD ALLOW SHRA/TSRA TO DEVELOP THROUGH THE PERIOD. BUT NO STRONG FORCING MAKES TIMING ANY PCPN AT TAF SITES NEARLY IMPOSSIBLE. THEREFORE LEFT MENTION OUT AFTER THIS AFTERNOON. FOG AND STRATUS ONCE AGAIN POSSIBLE OVERNIGHT BUT LIKE THIS MORNING COULD BE HINDERED BY ANY CONVECTION AND LINGERING HIGHER CLOUDS. KEPT A MVFR GROUP IN FOR NOW AND WILL WAIT TO SEE HOW THINGS DEVELOP. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...CEO SYNOPSIS...CEO SHORT TERM...AGD LONG TERM...T AVIATION...LASHLEY VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
113 PM EDT FRI OCT 4 2013 .SYNOPSIS... ISSUED AT 113 PM EDT FRI OCT 4 2013 A WARM AND MOIST AIRMASS WILL REMAIN OVER THE REGION INTO THE WEEKEND. PERIODIC SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON THROUGH LATE SATURDAY NIGHT WHEN A COLD FRONT APPROACHES THE AREA FROM THE WEST. WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE WITH HIGHS IN THE LOW 80S AND LOWS IN THE MID 60S. && .UPDATE... ISSUED AT 113 PM EDT FRI OCT 4 2013 GRID UPDATE EARLY THIS AFTERNOON TO ACCOUNT FOR DEVELOPMENT OF SCT SHOWERS AND THUNDERSTORMS. BREAKS IN CLOUD COVER LATE THIS MORNING AND EARLY AFTERNOON HAVE ALLOWED FOR TEMPERATURES TO QUICKLY WARM INTO THE UPPER 70S TO LOW 80S IN MOST LOCATIONS. SCT SHOWERS POPPING UP AS CONVECTIVE TEMPS REACHED WITH SB CAPE VALUES EXCEEDING 1000 J/KG. LATEST HRRR AND RAP RUNS HAVE CAPTURED THIS DECENTLY AND SUSPECT THIS ACTIVITY WILL CONTINUE INTO THE EVENING HOURS. THEREFORE HAVE ADDED SCT TSRA ACROSS ENTIRE AREA THRU 00Z. ONLY MINOR CHANGES MADE TO TEMPS AND SKY COVER GRIDS. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 342 AM EDT FRI OCT 4 2013 LEE CYCLOGENESIS IS NOW WELL UNDERWAY ACROSS THE CENTRAL PLAINS AS 100+ KT JET ROUNDS THE BASE OF LONGWAVE TROUGH PRESENTLY OVER THE ROCKIES. ASSOCIATED VORT MAX IS VERY IMPRESSIVE WITH A CLASSIC TREBLE CLEF SIGNATURE DEVELOPING ON THE 1.5 PVU SURFACE TODAY...AND THE MAIN PV LOBE EXTENDING THROUGH MOST OF THE TROPOSPHERE. THIS STRONG PV ADVECTION WILL COMBINE WITH GOOD DIFFLUENCE ALOFT AND SOME SEMBLANCE OF A COUPLED UPPER JET STRUCTURE TO SUPPORT CONTINUED STRENGTHENING OF THE CENTRAL PLAINS SURFACE LOW. WHAT THIS MEANS LOCALLY IS THAT SOUTHWEST FLOW/THETA-E ADVECTION WILL PERSIST THROUGH THE SHORT TERM WITH A LITANY OF CONVECTIVELY ENHANCED SHORTWAVES CONTINUING TO IMPACT THE SOUTHERN GREAT LAKES. SURFACE WARM FRONT WILL REMAIN DRAPED JUST TO OUR NORTH AND SUBTLE HEIGHT RISES DOWNSTREAM OF APPROACHING TROUGH SHOULD KEEP THE BULK OF OUR AREA DRY TODAY AS THE FOCUS OF CONVECTION REMAINS IN LOWER MICHIGAN. CONFIDENCE IN THIS SCENARIO REMAINS LOW HOWEVER GIVEN WEAK/BROAD 300-305K ISENTROPIC ASCENT AND VERY LITTLE CONVECTIVE INHIBITION ON NEWEST NAM AND GFS BUFR SOUNDINGS. NOTHING IN THE LATEST RADAR IMAGERY OR HI-RES GUIDANCE TO SUPPORT ALTERING DRY FORECAST AFTER REMAINING SHOWERS EXIT AROUND 12Z...BUT WILL HAVE TO KEEP AN EYE ON THIS THROUGHOUT THE DAY AS AN ISOLATED SHOWERS/STORM IS CERTAINLY NOT OUTSIDE THE REALM OF POSSIBILITY. THIS WILL BE ESPECIALLY TRUE IN OUR FAR NORTHERN COUNTIES...CLOSER TO THE SURFACE WARM FRONT AND EXPECTED TRAIN OF W-E ORIENTED CONVECTIVE CLUSTERS. CONFIDENCE IN HIGH TEMP FORECAST IS SIMILARLY LOW. ANY SUSTAINED BREAKS IN CLOUD COVER COULD ALLOW HIGHS TO SURGE WELL INTO THE MID 80S GIVEN 850MB TEMPS AROUND 16C. EXPECT THERE WILL STILL BE A FAIR AMOUNT OF CLOUDS IN THE AFTERNOON THOUGH AND WILL MAINTAIN HIGHS IN THE LOW TO MID 80S. LITTLE CHANGES DURING THE OVERNIGHT PERIOD AS WE REMAIN IN A REGION OF BROAD WARM/MOIST AIR ADVECTION. LACK OF CLEAR FORCING MECHANISM AT THIS POINT WARRANTS JUST A LOW CHANCE OF POPS. LOWS WILL BE VERY MILD...LIKELY NOT DROPPING MUCH BELOW THE UPPER 60S IN THIS VERY MOIST ENVIRONMENT. COULD ALSO BE A FEW AREAS OF FOG OVERNIGHT GIVEN POOLING MOISTURE AND LIGHT SURFACE WINDS BENEATH A STRENGTHENING INVERSION. MAV AND MET GUIDANCE BOTH SUPPORT PERIODS OF FOG BUT WITH THE FRONT NORTH OF HERE AND VERY LITTLE FOG THIS MORNING...WILL LEAVE OUT MENTION FOR NOW AND LET LATER SHIFT MODIFY AS NECESSARY. && .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 342 AM EDT FRI OCT 4 2013 VRY INTENSE SW TROUGH AND ATTENDANT UPR JET STREAK CARVING OUT AN IMPRESSIVE CYCLONE ACRS THE CNTRL ROCKIES THIS MORNING. SFC LOW CNTRD OVR SE CO WILL LIFT NEWD AND OCCLUDE INTO SAT MORNING ACRS SERN SD AND YIELD A SLW EWD EJECTION OF SFC OCCLUSION. BROAD/MOIST WARM SECTOR WILL PERSIST EWD ACRS THE LAKES/OH VALLEY YET W/MINIMAL BACKGROUND FOCUS. THUS KEPT W/A MINIMIZED LOWER BLENDED POP THROUGH SAT AFTN. CONTD EWD PROGRESSION OF OCCLUDED FNT LT SAT NIGHT WILL BRING ABT A PD OF SHRA/TSRA AND LIKELY LINGER ACRS ERN ZONES THROUGH SUN AFTN. OTRWS STG NEG THETA-E ADVTN SHLD WRAP QUICKLY EWD SWD OF MID LVL CYCLONE SUN NIGHT. SFC RIDGING AND FLATTENING FLW ALOFT FOLLOW IN WAKE OF THIS SYS FOR MID PD W/ABV NORMAL TEMPS DVLPG LT PD IN RESPONSE TO RENEWED DEEP WRN TROUGHING TWD DYS 6-7. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 555 AM EDT FRI OCT 4 2013 MAINLY VFR CONDITIONS EXPECTED TODAY AS SURFACE WARM FRONT AND ASSOCIATED CONVECTION REMAIN DRAPED JUST NORTH OF OUR AREA. LOW END VFR CEILINGS POSSIBLE ONCE DIURNAL HEATING BEGINS BUT FOCUS OF WARM/MOIST AIR ADVECTION WILL KEEP MOST PRECIP NORTH AND WEST OF THE TERMINALS. PATCHY FOG IS POSSIBLE AGAIN TONIGHT GIVEN LIGHT WINDS AND HIGH SURFACE DEWPOINTS. MAV AND MET GUIDANCE SHOW PERIODS OF FOG DEVELOPING BUT CLOUD COVER MAY INHIBIT RADIATIONAL LOSSES ONCE AGAIN AND WILL HOLD OFF ON ANY MENTION FOR NOW GIVEN ONLY WEAK SIGNAL SEEN IN FORECAST SOUNDINGS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ UPDATE...CEO SYNOPSIS...CEO SHORT TERM...AGD LONG TERM...T AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1244 PM CDT FRI OCT 4 2013 .UPDATE... ISSUED AT 1236 PM CDT FRI OCT 4 2013 UPDATED THE FORECAST TO REFLECT CURRENT TRENDS ACROSS MY CWA. ABUNDANT CLOUD COVER AND SCATTERED SHOWERS AND THUNDERSTORMS ARE KEEPING TEMPERATURES LOWER THAN PREVIOUSLY FORECAST SO TEMPERATURES WERE LOWER BY ROUGHLY 5 DEGREES ALONG AND NORTH OF INTERSTATE 80 TO A COUPLE OF DEGREES TO THE SOUTH. WILL BE A BREAK IN THE ACTIVITY THIS AFTERNOON BEFORE THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ARE EXPECTED BY LATE AFTERNOON INTO THE EARLY EVENING. $$ DC UPDATE ISSUED AT 648 AM CDT FRI OCT 4 2013 THE FIRST STORM COMPLEX IS MOVING INTO SOUTHERN WISCONSIN. THE NEXT STORM SYSTEM IN WESTERN/CENTRAL IOWA IS SLOWLY FALLING APART BUT ISOLATED TO SCATTERED SHOWERS AND SOME THUNDERSTORMS WILL BE POSSIBLE THROUGH LATE MORNING. THERE ARE CONCERNS ABOUT TEMPERATURES DUE TO CLOUD COVER AND THE REMNANT COLD POOL FROM THE OVERNIGHT STORMS. THE COLD POOL AND CLOUD COVER MAY SUPPRESS TEMPERATURES ACROSS THE NORTHERN CWFA DURING THE DAY WITH COOLER THAN EXPECTED READINGS. THE EDGE OF THE COLD POOL WILL ALSO PROVIDE A BOUNDARY FOR ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON AND EVENING HOURS. && .SYNOPSIS... ISSUED AT 248 AM CDT FRI OCT 4 2013 06Z SFC ANALYSIS HAD A WEAK LOW NEAR KOLZ WITH ADDITIONAL LOWS FROM NORTHWEST KANSAS INTO SOUTHEAST COLORADO. THE MAIN FRONT RAN FROM UPPER MICHIGAN...TO NEAR KOLZ...BACK TO AROUND KHLC. WEAK BOUNDARIES FROM CONVECTION WERE ACROSS NORTHERN ILLINOIS AND EASTERN IOWA. DEW POINTS WERE IN THE 60S SOUTH AND EAST OF THE FRONT WITH 40S AND 50S BEHIND THE FRONT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 248 AM CDT FRI OCT 4 2013 THE CURRENT CONVECTION IS BEING SUPPORTED BY A DISTURBANCE ALOFT. PER THE GEM REGIONAL AND RAP TRENDS THIS SHORTWAVE WILL ALLOW CONVECTION TO PERSIST THROUGH SUNRISE AND THE MORNING HOURS GENERALLY NORTH OF I-80. INTERACTION WITH BOUNDARIES MAY ALLOW ISOLATED CONVECTION TO DEVELOP JUST SOUTH OF I-80. ONCE THE SHORTWAVE PASSES A LULL IN PRECIPITATION SHOULD BE SEEN THROUGH THE AFTERNOON. DIFFERENTIAL HEATING MAY ALLOW ISOLATED TO LOW END SCATTERED CONVECTION TO DEVELOP DURING THE HEAT OF THE DAY. THE SEVERE WEATHER THREAT TODAY APPEARS TO BE LOW RIGHT NOW. TEMPERATURES WILL BE HIGHLY DEPENDENT UPON CLOUD COVER AND PRECIPITATION. THE POTENTIAL DOES EXIST FOR A 15 DEGREE GRADIENT ACROSS THE AREA WITH THE COOLEST READINGS IN THE HWY 20 CORRIDOR. TONIGHT...ISOLATED TO LOW END SCATTERED CONVECTION SHOULD BE SEEN DURING THE EVENING. BETTER FORCING ASSOCIATED WITH THE MAIN COLD FRONT IS EXPECTED TO ALLOW MORE WIDESPREAD CONVECTION TO DEVELOP DURING THE LATE EVENING AND OVERNIGHT HOURS THAT MOVES FROM WEST TO EAST ACROSS THE CWFA. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 248 AM CDT FRI OCT 4 2013 EARLY FALL COLD TO BRING COLDEST AIR OF THE FALL WITH RISK OF PATCHY FROST WITH DRY WEATHER AFTER ITS PASSAGE. OVERVIEW...INITIALIZATION AND VERIFICATION FAIR WITH ONGOING PROBLEMS WITH COLD AIR IN PLAINS UNDERDONE. THIS HAS BEEN THE CASE THE PAST 24 PLUS HOURS WITH A MORE SOUTHERLY AND TRACK OF LOW AND ALSO COLDER WEATHER AFTER FRONT. THIS IS RELATED TO STRONG NEGATIVE FEEDBACK ISSUES OF MAJOR SNOWS IN NORTHERN HIGH PLAINS AND DEEP MOIST AIR. SOME FURTHER SHIFT OF LOW TRACK SUPPORTED NEXT 24 HOURS WITH UPPER LOW PASSING OVER AT LEAST NORTH SECTIONS WITH A DEEPLY OCCLUDED LOW SYSTEM ON SUNDAY. CONTINUITY AND THERMAL FIELDS SUPPORTS A 70/30 MIX OF HI-RES ECMWF AND GFS. THIS WOULD SUGGEST COLDER TEMPERATURES AFTER FRONTAL PASSAGE AND SLIGHT COLDER TEMPERATURES INTO TUESDAY AM FOR LATER SHIFTS. SATURDAY...DEEPLY OCCLUDED SURFACE FRONT TO PASS IN AM WITH LIMITED INSTABILITY FOR SHOWERS AND ISOLATED EMBEDDED STORMS THAT WOULD NOT BE SEVERE. RAISED POPS WITH DEEPER FORCING WITH WIDESPREAD MODERATE RAIN AMOUNTS WITH PASSAGE. FALLING TEMPERATURES MOST OF THE REGION BY MID/LATE PM WITH BLUSTERY WESTERLY WINDS. SATURDAY NIGHT..DRY SLOW FOR CLEAR TO PARTLY CLOUDY SKIES AND LOW DEWPOINT AND LOTS OF COLD AIR ALOFT MAY ALLOW FOR UPPER 30S FOR LATER SHIFTS TO REASSESS. THIS MAY ALSO BE NEEDED WITH COLDER TRENDS FROM NEGATIVE FEEDBACK ISSUES DISCUSSED EARLIER. IF FRONT ARRIVES SOONER THEN HIGHS WILL NEED LOWERING BY 5 DEGREES OR MORE FOR LATER SHIFTS TO RECONSIDER. SUNDAY...INCREASED POPS...CLOUDS AND A BIT COLDER WITH NW SECTIONS POSSIBLY NEEDING LOWERING BY AT LEAST ANOTHER CATEGORY WITH NEAR 50F READINGS NOT OUT OF THE QUESTION. LIGHT RAIN AND SHOWERS WITH DIURNAL HEATING MAY NEED RAISING TO LIKELY OVER NORTHERN SECTIONS WITH A FEW HUNDREDTHS OF AN INCH...ENOUGH TO WET THE GROUND. BLUSTERY WESTERLY WINDS OF 15 TO 25 MPH TO MAKE COOLER WEATHER MORE NOTICEABLE. SUNDAY NIGHT...CLEARING AND COOL WITH KEY QUESTION OF BL DECOUPLING AND CLEARING...IF THIS OCCURS THEN LOWS TO NEAR FREEZING ARE POSSIBLE FOR LATER SHIFTS TO REASSESS. THE POOR CONFIDENCE IN MODEL TRENDS MAKE THIS POOR TO QUANTIFY ATTM. MONDAY AND TUESDAY...FAIR WITH A WARMING TREND WITH WIDE DIURNAL TEMPERATURE CHANGES. LATER SHIFTS MAY NEED TO TRIM MINS BY A CATEGORY. HIGHS IN THE 60S MONDAY AND UPPER 60S TO LOWER 70S TUESDAY WITH LOWS TUESDAY AM CURRENTLY IN THE MIDDLE 40S. WEDNESDAY AND THURSDAY...MILD WITH LIGHT TO MODERATE SOUTHERLY WINDS AND FAIR SKIES TO MAKE NICE EARLY OCTOBER WEATHER. HIGHS IN THE 70S AND LOWS MOSTLY IN THE LOWER 50S. UPPER 40S IN FAVORED LOW LYING LOCATIONS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1236 PM CDT FRI OCT 4 2013 SCATTERED SHOWERS AND THUNDERSTORMS ARE CURRENTLY MOVING THROUGH KDBQ...KMLI...AND KBRL. CURRENT MVFR CEILINGS AND VISIBILITIES WILL QUICKLY IMPROVE OVER THE NEXT HOUR AS THIS LINE OF SHOWERS AND THUNDERSTORMS EXITS EASTWARD. SHOULD BE A BREAK IN ACTIVITY THIS AFTERNOON BEFORE THE REDEVELOPMENT OF SHOWER AND THUDNERSTORMS ACTIVITY THIS EVENING AND CONTINUING OVERNIGHT AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH THE REGION AROUND 18 UTC ON SATURDAY. EXPECT AT LEAST MVFR CEILINGS TO DEVELOP AT ALL TAF SITES BY LATE TONIGHT AND CONTINUE INTO THE MORNING. SOUTHERLY WINDS WILL INCREASE BY MID MORNING ON SATURDAY AND QUICKLY BECOME SOUTHWESTERLY AS THE FRONT APPROACHES. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...DC SYNOPSIS...08 SHORT TERM...08 LONG TERM...NICHOLS AVIATION...DC
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
657 AM CDT FRI OCT 4 2013 .UPDATE... ISSUED AT 648 AM CDT FRI OCT 4 2013 THE FIRST STORM COMPLEX IS MOVING INTO SOUTHERN WISCONSIN. THE NEXT STORM SYSTEM IN WESTERN/CENTRAL IOWA IS SLOWLY FALLING APART BUT ISOLATED TO SCATTERED SHOWERS AND SOME THUNDERSTORMS WILL BE POSSIBLE THROUGH LATE MORNING. THERE ARE CONCERNS ABOUT TEMPERATURES DUE TO CLOUD COVER AND THE REMNANT COLD POOL FROM THE OVERNIGHT STORMS. THE COLD POOL AND CLOUD COVER MAY SUPPRESS TEMPERATURES ACROSS THE NORTHERN CWFA DURING THE DAY WITH COOLER THAN EXPECTED READINGS. THE EDGE OF THE COLD POOL WILL ALSO PROVIDE A BOUNDARY FOR ISOLATED TO SCATTERED CONVECTION DURING THE AFTERNOON AND EVENING HOURS. && .SYNOPSIS... ISSUED AT 248 AM CDT FRI OCT 4 2013 06Z SFC ANALYSIS HAD A WEAK LOW NEAR KOLZ WITH ADDITIONAL LOWS FROM NORTHWEST KANSAS INTO SOUTHEAST COLORADO. THE MAIN FRONT RAN FROM UPPER MICHIGAN...TO NEAR KOLZ...BACK TO AROUND KHLC. WEAK BOUNDARIES FROM CONVECTION WERE ACROSS NORTHERN ILLINOIS AND EASTERN IOWA. DEW POINTS WERE IN THE 60S SOUTH AND EAST OF THE FRONT WITH 40S AND 50S BEHIND THE FRONT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 248 AM CDT FRI OCT 4 2013 THE CURRENT CONVECTION IS BEING SUPPORTED BY A DISTURBANCE ALOFT. PER THE GEM REGIONAL AND RAP TRENDS THIS SHORTWAVE WILL ALLOW CONVECTION TO PERSIST THROUGH SUNRISE AND THE MORNING HOURS GENERALLY NORTH OF I-80. INTERACTION WITH BOUNDARIES MAY ALLOW ISOLATED CONVECTION TO DEVELOP JUST SOUTH OF I-80. ONCE THE SHORTWAVE PASSES A LULL IN PRECIPITATION SHOULD BE SEEN THROUGH THE AFTERNOON. DIFFERENTIAL HEATING MAY ALLOW ISOLATED TO LOW END SCATTERED CONVECTION TO DEVELOP DURING THE HEAT OF THE DAY. THE SEVERE WEATHER THREAT TODAY APPEARS TO BE LOW RIGHT NOW. TEMPERATURES WILL BE HIGHLY DEPENDENT UPON CLOUD COVER AND PRECIPITATION. THE POTENTIAL DOES EXIST FOR A 15 DEGREE GRADIENT ACROSS THE AREA WITH THE COOLEST READINGS IN THE HWY 20 CORRIDOR. TONIGHT...ISOLATED TO LOW END SCATTERED CONVECTION SHOULD BE SEEN DURING THE EVENING. BETTER FORCING ASSOCIATED WITH THE MAIN COLD FRONT IS EXPECTED TO ALLOW MORE WIDESPREAD CONVECTION TO DEVELOP DURING THE LATE EVENING AND OVERNIGHT HOURS THAT MOVES FROM WEST TO EAST ACROSS THE CWFA. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 248 AM CDT FRI OCT 4 2013 EARLY FALL COLD TO BRING COLDEST AIR OF THE FALL WITH RISK OF PATCHY FROST WITH DRY WEATHER AFTER ITS PASSAGE. OVERVIEW...INITIALIZATION AND VERIFICATION FAIR WITH ONGOING PROBLEMS WITH COLD AIR IN PLAINS UNDERDONE. THIS HAS BEEN THE CASE THE PAST 24 PLUS HOURS WITH A MORE SOUTHERLY AND TRACK OF LOW AND ALSO COLDER WEATHER AFTER FRONT. THIS IS RELATED TO STRONG NEGATIVE FEEDBACK ISSUES OF MAJOR SNOWS IN NORTHERN HIGH PLAINS AND DEEP MOIST AIR. SOME FURTHER SHIFT OF LOW TRACK SUPPORTED NEXT 24 HOURS WITH UPPER LOW PASSING OVER AT LEAST NORTH SECTIONS WITH A DEEPLY OCCLUDED LOW SYSTEM ON SUNDAY. CONTINUITY AND THERMAL FIELDS SUPPORTS A 70/30 MIX OF HI-RES ECMWF AND GFS. THIS WOULD SUGGEST COLDER TEMPERATURES AFTER FRONTAL PASSAGE AND SLIGHT COLDER TEMPERATURES INTO TUESDAY AM FOR LATER SHIFTS. SATURDAY...DEEPLY OCCLUDED SURFACE FRONT TO PASS IN AM WITH LIMITED INSTABILITY FOR SHOWERS AND ISOLATED EMBEDDED STORMS THAT WOULD NOT BE SEVERE. RAISED POPS WITH DEEPER FORCING WITH WIDESPREAD MODERATE RAIN AMOUNTS WITH PASSAGE. FALLING TEMPERATURES MOST OF THE REGION BY MID/LATE PM WITH BLUSTERY WESTERLY WINDS. SATURDAY NIGHT..DRY SLOW FOR CLEAR TO PARTLY CLOUDY SKIES AND LOW DEWPOINT AND LOTS OF COLD AIR ALOFT MAY ALLOW FOR UPPER 30S FOR LATER SHIFTS TO REASSESS. THIS MAY ALSO BE NEEDED WITH COLDER TRENDS FROM NEGATIVE FEEDBACK ISSUES DISCUSSED EARLIER. IF FRONT ARRIVES SOONER THEN HIGHS WILL NEED LOWERING BY 5 DEGREES OR MORE FOR LATER SHIFTS TO RECONSIDER. SUNDAY...INCREASED POPS...CLOUDS AND A BIT COLDER WITH NW SECTIONS POSSIBLY NEEDING LOWERING BY AT LEAST ANOTHER CATEGORY WITH NEAR 50F READINGS NOT OUT OF THE QUESTION. LIGHT RAIN AND SHOWERS WITH DIURNAL HEATING MAY NEED RAISING TO LIKELY OVER NORTHERN SECTIONS WITH A FEW HUNDREDTHS OF AN INCH...ENOUGH TO WET THE GROUND. BLUSTERY WESTERLY WINDS OF 15 TO 25 MPH TO MAKE COOLER WEATHER MORE NOTICEABLE. SUNDAY NIGHT...CLEARING AND COOL WITH KEY QUESTION OF BL DECOUPLING AND CLEARING...IF THIS OCCURS THEN LOWS TO NEAR FREEZING ARE POSSIBLE FOR LATER SHIFTS TO REASSESS. THE POOR CONFIDENCE IN MODEL TRENDS MAKE THIS POOR TO QUANTIFY ATTM. MONDAY AND TUESDAY...FAIR WITH A WARMING TREND WITH WIDE DIURNAL TEMPERATURE CHANGES. LATER SHIFTS MAY NEED TO TRIM MINS BY A CATEGORY. HIGHS IN THE 60S MONDAY AND UPPER 60S TO LOWER 70S TUESDAY WITH LOWS TUESDAY AM CURRENTLY IN THE MIDDLE 40S. WEDNESDAY AND THURSDAY...MILD WITH LIGHT TO MODERATE SOUTHERLY WINDS AND FAIR SKIES TO MAKE NICE EARLY OCTOBER WEATHER. HIGHS IN THE 70S AND LOWS MOSTLY IN THE LOWER 50S. UPPER 40S IN FAVORED LOW LYING LOCATIONS. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 648 AM CDT FRI OCT 4 2013 THUNDERSTORM COMPLEX ALONG THE MISSISSIPPI RIVER WILL MOVE INTO SOUTHERN WISCONSIN AND FAR NORTHERN ILLINOIS. CONDITIONS RANGE FROM VFR TO IFR DUE TO STORMS AND LOW CLOUDS. MVFR TO VFR CONDITIONS ARE EXPECTED THROUGH 00Z/05 BUT THE POTENTIAL DOES EXIST FOR BLO 1KFT CIGS DUE TO HIGH MOISTURE LEVELS IN THE LOWER ATMOSPHERE AT KMLI/KBRL. ISOLD TO SCT CONVECTION WILL BE POSSIBLE THROUGH 04Z/05. AFT 04Z/05 A STRONG COLD FRONT WILL SWEEP THROUGH EASTERN IOWA AND ILLINOIS WITH TSRA POSSIBLE ALONG WITH MVFR CONDITIONS. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...08 SHORT TERM...08 LONG TERM...NICHOLS AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
327 AM CDT FRI OCT 4 2013 .SYNOPSIS... ISSUED AT 248 AM CDT FRI OCT 4 2013 06Z SFC ANALYSIS HAD A WEAK LOW NEAR KOLZ WITH ADDITIONAL LOWS FROM NORTHWEST KANSAS INTO SOUTHEAST COLORADO. THE MAIN FRONT RAN FROM UPPER MICHIGAN...TO NEAR KOLZ...BACK TO AROUND KHLC. WEAK BOUNDARIES FROM CONVECTION WERE ACROSS NORTHERN ILLINOIS AND EASTERN IOWA. DEW POINTS WERE IN THE 60S SOUTH AND EAST OF THE FRONT WITH 40S AND 50S BEHIND THE FRONT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 248 AM CDT FRI OCT 4 2013 THE CURRENT CONVECTION IS BEING SUPPORTED BY A DISTURBANCE ALOFT. PER THE GEM REGIONAL AND RAP TRENDS THIS SHORTWAVE WILL ALLOW CONVECTION TO PERSIST THROUGH SUNRISE AND THE MORNING HOURS GENERALLY NORTH OF I-80. INTERACTION WITH BOUNDARIES MAY ALLOW ISOLATED CONVECTION TO DEVELOP JUST SOUTH OF I-80. ONCE THE SHORTWAVE PASSES A LULL IN PRECIPITATION SHOULD BE SEEN THROUGH THE AFTERNOON. DIFFERENTIAL HEATING MAY ALLOW ISOLATED TO LOW END SCATTERED CONVECTION TO DEVELOP DURING THE HEAT OF THE DAY. THE SEVERE WEATHER THREAT TODAY APPEARS TO BE LOW RIGHT NOW. TEMPERATURES WILL BE HIGHLY DEPENDENT UPON CLOUD COVER AND PRECIPITATION. THE POTENTIAL DOES EXIST FOR A 15 DEGREE GRADIENT ACROSS THE AREA WITH THE COOLEST READINGS IN THE HWY 20 CORRIDOR. TONIGHT...ISOLATED TO LOW END SCATTERED CONVECTION SHOULD BE SEEN DURING THE EVENING. BETTER FORCING ASSOCIATED WITH THE MAIN COLD FRONT IS EXPECTED TO ALLOW MORE WIDESPREAD CONVECTION TO DEVELOP DURING THE LATE EVENING AND OVERNIGHT HOURS THAT MOVES FROM WEST TO EAST ACROSS THE CWFA. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 248 AM CDT FRI OCT 4 2013 EARLY FALL COLD TO BRING COLDEST AIR OF THE FALL WITH RISK OF PATCHY FROST WITH DRY WEATHER AFTER ITS PASSAGE. OVERVIEW...INITIALIZATION AND VERIFICATION FAIR WITH ONGOING PROBLEMS WITH COLD AIR IN PLAINS UNDERDONE. THIS HAS BEEN THE CASE THE PAST 24 PLUS HOURS WITH A MORE SOUTHERLY AND TRACK OF LOW AND ALSO COLDER WEATHER AFTER FRONT. THIS IS RELATED TO STRONG NEGATIVE FEEDBACK ISSUES OF MAJOR SNOWS IN NORTHERN HIGH PLAINS AND DEEP MOIST AIR. SOME FURTHER SHIFT OF LOW TRACK SUPPORTED NEXT 24 HOURS WITH UPPER LOW PASSING OVER AT LEAST NORTH SECTIONS WITH A DEEPLY OCCLUDED LOW SYSTEM ON SUNDAY. CONTINUITY AND THERMAL FIELDS SUPPORTS A 70/30 MIX OF HI-RES ECMWF AND GFS. THIS WOULD SUGGEST COLDER TEMPERATURES AFTER FRONTAL PASSAGE AND SLIGHT COLDER TEMPERATURES INTO TUESDAY AM FOR LATER SHIFTS. SATURDAY...DEEPLY OCCLUDED SURFACE FRONT TO PASS IN AM WITH LIMITED INSTABILITY FOR SHOWERS AND ISOLATED EMBEDDED STORMS THAT WOULD NOT BE SEVERE. RAISED POPS WITH DEEPER FORCING WITH WIDESPREAD MODERATE RAIN AMOUNTS WITH PASSAGE. FALLING TEMPERATURES MOST OF THE REGION BY MID/LATE PM WITH BLUSTERY WESTERLY WINDS. SATURDAY NIGHT..DRY SLOW FOR CLEAR TO PARTLY CLOUDY SKIES AND LOW DEWPOINT AND LOTS OF COLD AIR ALOFT MAY ALLOW FOR UPPER 30S FOR LATER SHIFTS TO REASSESS. THIS MAY ALSO BE NEEDED WITH COLDER TRENDS FROM NEGATIVE FEEDBACK ISSUES DISCUSSED EARLIER. IF FRONT ARRIVES SOONER THEN HIGHS WILL NEED LOWERING BY 5 DEGREES OR MORE FOR LATER SHIFTS TO RECONSIDER. SUNDAY...INCREASED POPS...CLOUDS AND A BIT COLDER WITH NW SECTIONS POSSIBLY NEEDING LOWERING BY AT LEAST ANOTHER CATEGORY WITH NEAR 50F READINGS NOT OUT OF THE QUESTION. LIGHT RAIN AND SHOWERS WITH DIURNAL HEATING MAY NEED RAISING TO LIKELY OVER NORTHERN SECTIONS WITH A FEW HUNDREDTHS OF AN INCH...ENOUGH TO WET THE GROUND. BLUSTERY WESTERLY WINDS OF 15 TO 25 MPH TO MAKE COOLER WEATHER MORE NOTICEABLE. SUNDAY NIGHT...CLEARING AND COOL WITH KEY QUESTION OF BL DECOUPLING AND CLEARING...IF THIS OCCURS THEN LOWS TO NEAR FREEZING ARE POSSIBLE FOR LATER SHIFTS TO REASSESS. THE POOR CONFIDENCE IN MODEL TRENDS MAKE THIS POOR TO QUANTIFY ATTM. MONDAY AND TUESDAY...FAIR WITH A WARMING TREND WITH WIDE DIURNAL TEMPERATURE CHANGES. LATER SHIFTS MAY NEED TO TRIM MINS BY A CATEGORY. HIGHS IN THE 60S MONDAY AND UPPER 60S TO LOWER 70S TUESDAY WITH LOWS TUESDAY AM CURRENTLY IN THE MIDDLE 40S. WEDNESDAY AND THURSDAY...MILD WITH LIGHT TO MODERATE SOUTHERLY WINDS AND FAIR SKIES TO MAKE NICE EARLY OCTOBER WEATHER. HIGHS IN THE 70S AND LOWS MOSTLY IN THE LOWER 50S. UPPER 40S IN FAVORED LOW LYING LOCATIONS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 248 AM CDT FRI OCT 4 2013 A LOW CONFIDENCE AND SOMEWHAT STORMY LATE NIGHT OF AVIATION WEATHER IS EXPECTED. SCATTERED SHOWERS AND SOME THUNDERSTORMS WILL BE FOUND OVER THE REGION...MAINLY NORTH OF THE IOWA AND MISSOURI BORDER. THESE WILL CONTINUE TO BECOME MUCH MORE NUMEROUS INTO EARLY FRIDAY MORNING. THUNDERSTORMS HAVE BEEN INCREASED IN DURATION AT ALL SITES EXCEPT BRL AS THE WARM FRONT WILL NOT MOVE INTO WISCONSIN...BUT STAY OVER SOUTHERN IOWA. AFTER A PERIOD OF MORNING SHOWERS AND STORMS...A BREAK IS EXPECTED UNTIL LATE EVENING WHEN THE COLD FRONT AND UPPER SYSTEM WILL BRING ANOTHER ROUND OF SHOWERS AND POSSIBLE STORMS. IN ADDITION TO ALL THIS...THERE IS POTENTIAL FOR FOG AT DBQ...WHICH IS FAR ENOUGH NORTH OF THE FRONT THAT SOME GROUND FOG MAY MOVE IN PRIOR TO SUNRISE. THIS IS A CHALLENGING FORECAST...AND UPDATES ARE LIKELY DUE TO THE CHANGEABLE SIGNIFICANT WEATHER EXPECTED. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...08 SHORT TERM...08 LONG TERM...NICHOLS AVIATION...08
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1044 PM CDT Sat Oct 5 2013 ...Update to short term forecast... .UPDATE... Issued at 1029 PM CDT SAT OCT 5 2013 Have updated the overnight forecast primarily for the addition of sprinkles across northern Kansas, mainly after midnight. The upper low will track toward the southeast overnight and light shower activity currently over central and eastern Nebraska will make their way southeast into northern Kansas. Do not expect anything measurable at this time. Temperatures have been tracking fairly well, and while a reinforcing shot of cold air is working its way into Kansas this evening, it is accompanied by cloud cover and continued winds/mixing. All of this together should keep overnight lows around the 40 degree mark, with a few upper 30s possible. In the odd event that temps fall below 38, wind should help prevent any frost development. && .SHORT TERM...(This Evening through Sunday) Issued at 320 PM CDT SAT OCT 5 2013 20Z water vapor imagery shows the closed upper low over southeast SD slowly propagating east. A shortwave trough axis has rotated through eastern KS helping to clear out the mid level clouds. At the surface the cold front had pushed well east and south with dry cool air advecting in from the west. For tonight and Sunday, the forecast calls for generally dry weather as there is little moisture to work with and large scale forcing should remain to the north and east of the forecast area. Did leave some slight chance pops in the far northeastern corner of the forecast area during the day Sunday. As the upper low drifts across southwest IA, lapse rates could steepen enough for some isolated showers to move across Nemaha and Brown counties. The main thing to watch will be the STRATOCU deck to the north. The RAP and NAM show these clouds eventually moving into much of the forecast area overnight. This should have an impact on MIN and MAX temps. Models are in good agreement that the boundary layer will remain well mixed overnight with increasing clouds from the north. Therefore am fairly confident that MIN temps will not fall below 40 and even tweaks temps up a degree or two. The forecast may still be on the cool side if the clouds move in quicker. Highs Sunday are expected to warm back into the 60s for most areas. Forecast soundings mix the boundary layer almost to 800MB and models indicate the cold air advection will have ended. The main question is whether clouds will hold temps down. Added about 3 to 5 degrees to MAX temps across the western and southern counties where there should be more insolation with good mixing. Across northeastern KS where clouds are likely to hang in tough, kept highs in the middle 50s. Wolters .LONG TERM...(Sunday Night through Saturday) Issued at 320 PM CDT SAT OCT 5 2013 Upper low still on track to progress eastward through the mid MO and OH river valleys through Monday. Most of the moisture wrapping around the backside of the exiting upper may linger across the far northeast corner of the cwa early Sunday evening...so have left a slight chance in for that time period. Otherwise will go with a dry fcst Monday through Thursday night as upper level ridging will develop across the plains in the wake of the first trough exiting trough and ahead of the second upper trough that deepens over the west CONUS. Will continue to slowly but steadily increase high temps through the 70s Monday through Thursday...with a few low 80s on Thursday. As the western trough then lift out into the plains on Friday and Friday night...with more clouds and the potential for showers and thunderstorms cooled temps slightly for Friday before the frontal passage and and even cooler readings in the low to middle 70s on Saturday. Warmed low temps from near 40 Monday morning into the 50s by Wednesday on through the end of the week. && .AVIATION...(For the 00Z TAFs through 00Z Sunday Evening) Issued at 625 PM CDT SAT OCT 5 2013 Expect VFR conditions for the majority of the TAF period. The highest likelihood for MVFR cigs appears to fall between 11Z and 16Z, with better chances as you go northeast. For now, have introduced MVFR at TOP, but left MHK/FOE at SCT025. Otherwise, west to northwest winds will become gusty at 24 to 30 kts after 15Z through the remainder of the TAF. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barjenbruch SHORT TERM...Wolters LONG TERM...63 AVIATION...Barjenbruch
AREA FORECAST DISCUSSION
NWS JACKSON KY
934 PM EDT SAT OCT 5 2013 .UPDATE... ISSUED AT 934 PM EDT SAT OCT 5 2013 PRECIP HAS MOVED OUT OF THE AREA FOR THE TIME BEING. IT NOW APPEARS THAT IT WILL STAY MAINLY TO OUR NORTH AND WEST TONIGHT INTO SUNDAY. WOULD NOT RULE OUT SOMETHING SNEAKING INTO OUR NW COUNTIES...BUT IT LOOKS LIKE NOTHING MORE THAN 20-30 PERCENT POPS ARE IN ORDER NOW. UPDATE ISSUED AT 553 PM EDT SAT OCT 5 2013 SHOWERS/THUNDERSTORMS WHICH DEVELOPED IN CENTRAL KY HAVE HELD TOGETHER AS THEY MOVED INTO THE JKL FORECAST AREA...BUT WERE WEAKENING. UPDATED TO INCREASE POPS FOR EARLY THIS EVENING IN OUR NORTHERN COUNTIES. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 303 PM EDT SAT OCT 5 2013 COLD FRONT THROUGH THE AREA TONIGHT...SUNDAY...AND INTO THE DAY MONDAY. WILL CONCENTRATE ON TONIGHT THROUGH 0Z TUESDAY SINCE THIS IS WHEN THE MAIN ACTION WILL OCCUR. LATEST HI-RES MODEL GUIDANCE CONTINUES TO SHOW A SLOW PROGRESSION OF THE FRONT AND IT/S ASSOCIATED PRECIP. CREDIT PREVIOUS FORECAST FOR TAKING A SLOWER APPROACH OF THE SYSTEM...SINCE THIS SEEMS TO MATCH UP WELL WITH LATEST MODELS. AS IT IS...LATEST HRRR SHOWS SOME ISO PRECIP DEVELOPING ACROSS THE WESTERN EDGE OF THE CWA BY LATE THIS AFTERNOON...AHEAD OF THE MAIN LINE CURRENTLY LOCATED ACROSS FAR WESTERN KY...NORTH CENTRAL KY...AND PARTS OF INDIANA AND OHIO. WHAT CONVECTIVE INDUCED PRECIP THAT DOES DEVELOP WILL THEN DIE OFF WITH LOSS OF DAYTIME HEATING OVERNIGHT...AS THE MAIN LINE BEGINS ITS TREK SLIGHTLY EASTWARD. BY 15Z SUNDAY...THE LINE OF PRECIP WILL HAVE PROGRESSED TO CENTRAL KY AND EXPANDED ACROSS MUCH OF INDIANA AND WESTERN TN. IF THE LATEST NAM12 HOLDS TRUE...PRECIP CHANCES WILL NOT RE-ENTER THE CWA UNTIL AFTER THIS TIME. BY THIS POINT THE LINE WILL BE MOVING SLIGHTLY QUICKER...BUT WILL STILL HOLD ENOUGH MOISTURE TO DROP ABOUT AN INCH OF QPF IN IT/S DURATION. BY 0Z MONDAY...MUCH OF THE PRECIP SHOULD HAVE MOVED OUT OF THE REGION. HOWEVER...TROPICAL STORM KAREN...MOVING NE FROM THE GULF OF MEXICO...WILL BEGIN MERGING WITH THE LOW PRESSURE SYSTEM. THIS WILL CAUSE THE FRONT TO STALL OUT ONCE MORE ACROSS THE MORE MOUNTAINOUS AREAS TO OUR EAST...WITH HEAVY RAINS EXPECTED. ALTHOUGH THE UPPER LEVEL PATTERN IS IN FAIRLY GOOD AGREEMENT UP UNTIL THIS POINT...BY 0Z MONDAY THE PLACEMENT OF THE UPPER LEVEL TROUGH STARTS TO SHIFT DEPENDING ON THE MODEL. IF IT PASSES JUST A BIT FARTHER NORTH THAN THE OHIO RIVER...ALL RAIN CHANCES WILL CEASE BY 0Z TUESDAY. HOWEVER...IF THE LATEST NAM IS CORRECT...IT WILL TRACK THE LOW JUST A BIT FURTHER SOUTHWARD. ENOUGH TO CAUSE SOME WRAP AROUND MOISTURE ACROSS THE FAR NORTHERN SECTIONS OF THE STATE AS IT STALLS OUT. AT THIS POINT IT SEEMS AS THOUGH THIS WRAP AROUND MOISTURE WILL STAY JUST TO OUR WEST. AS FOR INSTABILITY...FOR THIS AFTERNOON AND TOMORROW AFTERNOON...WILL PROBABLY SEE THE BEST CHANCE FOR ANY ISOLATED TO SCT THUNDERSTORM DEVELOPMENT. HOWEVER SOUNDINGS STILL LOOK WEAK AT BEST FOR THIS TO HAPPEN. AS A RESULT...WILL NOT RULE OUT A FEW RUMBLES OF THUNDER HERE AND THERE WITH ANY SCT SHOWERS...BUT THE MAIN CONCERN WILL STILL BE THE RAINS. AS WAS NOTED BY THE PREVIOUS FORECASTER...THERE IS SOME MID/LEVEL DRYING IN THE LATEST NAM SOUNDINGS...SO SOME WINDY DOWNBURSTS COULD NOT BE OUT OF THE QUESTION. THAT BEING SAID...BY 3Z MONDAY...FORECAST SOUNDINGS SHOW A COMPLETELY SATURATED AIR MASS...LEADING TO THE LOSS OF CONVECTIVE ABILITY AND TURNING TO A MORE STRATIFORM EVENT AS THE MAIN LINE PASSES OVER. DRY AIR WILL FINALLY START TO WORK IN FOR MONDAY MORNING...BRINGING AN END TO ANY LINGERING PRECIP. AS FOR TEMPERATURES...AFTER A WARM START TO TODAY THANKS TO WARM AND MOIST SOUTHERLY FLOW...EXPECT SIMILAR CONDITIONS TOMORROW. THIS WILL HELP TO FURTHER INITIATE ANY SCT CONVECTION OUT AHEAD OF THE MAIN LINE OF SHOWERS. ONCE THE MAIN LINE OF SHOWERS STARTS MOVING INTO THE REGION DURING THE AFTERNOON HOURS...CONTINUOUS RAIN WILL BEGIN DROPPING THE TEMPERATURES FROM WEST TO EAST. AS A RESULT...HIGHS WILL BE MET EARLY ON...REACHING THE HIGHEST VALUES IN THE FAR EAST. ONCE THE FRONT PASSES THROUGH ON MONDAY...COLD AIR WILL FILTER IN BEHIND AND TEMPERATURES WILL START FALLING BEFORE THEY ARE ABLE TO REACH THEIR MAXIMUM POTENTIAL. HIGHS WILL ONLY REACH THE LOW TO MID 60S BY EARLY AFTERNOON BEFORE THEY START DROPPING BACK DOWN. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 245 PM EDT SAT OCT 5 2013 ANY LINGERING SHOWERS IN THE FAR EAST WILL BE ENDING EARLY MONDAY EVENING. THEN WITH THE COLD FRONT WELL TO OUR EAST AND SURFACE HIGH PRESSURE BUILDING INTO THE AREA MONDAY NIGHT WE WILL SEE COOL TEMPERATURES AND DRY WEATHER FOR THE START OF THE FORECAST PERIOD. IN THE WAKE OF THE EXITING UPPER LOW TO OUR NORTHEAST EARLY IN THE WEEK...RESIDUAL TROUGHING WILL GIVE WAY TO RISING HEIGHTS AS UPPER RIDGING GRADUALLY BUILDS INTO THE OH VALLEY. WITH UPPER RIDGING REMAINING OVER THE AREA INTO NEXT WEEKEND AND SURFACE HIGH PRESSURE SHIFTING TO OUR EAST WE WILL SEE SLOWLY WARMING TEMPERATURES AS THE WEEK CONTINUES...ESPECIALLY FOR MAXIMUMS. ALSO THE PATTERN WILL BE CONDUCIVE FOR RIDGE VALLEY TEMPERATURE DIFFERENCES FOR OVERNIGHT MINIMUMS...WITH INCREASING DIURNAL TEMPERATURE RANGES ESPECIALLY IN THE VALLEYS LATER IN THE WEEK. THE COMING WEEK WILL BE DRY WITH THE NEXT CHANCE FOR RAIN HOLDING OFF UNTIL THE APPROACH OF THE NEXT COLD FRONT WHICH IS STILL MORE THAN SEVEN DAYS AWAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 907 PM EDT SAT OCT 5 2013 ACTIVE WEATHER IN THE FORM OF SHOWERS AND THUNDERSTORMS WAS LOOMING JUST TO OUR NW...BUT SHOWERS WERE LEAVING THE JKL FORECAST AREA AS THE FORECAST PERIOD STARTED. CAN NOT RULE OUT SOMETHING SNEAKING INTO OUR NW COUNTIES BEFORE LATE SUNDAY...BUT IT SHOULD BE QUIET MOST OF THE TIME. FOG WILL AFFECT SOME OF THE TYPICALLY FOG PRONE VALLEYS IN THE FAR EASTERN AND SOUTHEASTERN PORTIONS OF THE STATE TONIGHT INTO EARLY SUNDAY MORNING...BUT IS NOT EXPECTED TO HAVE A SIGNIFICANT IMPACT AT TAF SITES. WIDESPREAD PRECIP IS EXPECTED TO BE MOVING INTO THE WESTERN PORTION OF THE FORECAST AREA NEAR THE END OF THE PERIOD...WITH DETERIORATING CONDITIONS WEST OF A LINE FROM SOMERSET TO FLEMINGSBURG BY 00Z SUNDAY EVENING. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...JMW LONG TERM...SBH AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
907 PM EDT SAT OCT 5 2013 .UPDATE... ISSUED AT 553 PM EDT SAT OCT 5 2013 SHOWERS/THUNDERSTORMS WHICH DEVELOPED IN CENTRAL KY HAVE HELD TOGETHER AS THEY MOVED INTO THE JKL FORECAST AREA...BUT WERE WEAKENING. UPDATED TO INCREASE POPS FOR EARLY THIS EVENING IN OUR NORTHERN COUNTIES. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 303 PM EDT SAT OCT 5 2013 COLD FRONT THROUGH THE AREA TONIGHT...SUNDAY...AND INTO THE DAY MONDAY. WILL CONCENTRATE ON TONIGHT THROUGH 0Z TUESDAY SINCE THIS IS WHEN THE MAIN ACTION WILL OCCUR. LATEST HI-RES MODEL GUIDANCE CONTINUES TO SHOW A SLOW PROGRESSION OF THE FRONT AND IT/S ASSOCIATED PRECIP. CREDIT PREVIOUS FORECAST FOR TAKING A SLOWER APPROACH OF THE SYSTEM...SINCE THIS SEEMS TO MATCH UP WELL WITH LATEST MODELS. AS IT IS...LATEST HRRR SHOWS SOME ISO PRECIP DEVELOPING ACROSS THE WESTERN EDGE OF THE CWA BY LATE THIS AFTERNOON...AHEAD OF THE MAIN LINE CURRENTLY LOCATED ACROSS FAR WESTERN KY...NORTH CENTRAL KY...AND PARTS OF INDIANA AND OHIO. WHAT CONVECTIVE INDUCED PRECIP THAT DOES DEVELOP WILL THEN DIE OFF WITH LOSS OF DAYTIME HEATING OVERNIGHT...AS THE MAIN LINE BEGINS ITS TREK SLIGHTLY EASTWARD. BY 15Z SUNDAY...THE LINE OF PRECIP WILL HAVE PROGRESSED TO CENTRAL KY AND EXPANDED ACROSS MUCH OF INDIANA AND WESTERN TN. IF THE LATEST NAM12 HOLDS TRUE...PRECIP CHANCES WILL NOT RE-ENTER THE CWA UNTIL AFTER THIS TIME. BY THIS POINT THE LINE WILL BE MOVING SLIGHTLY QUICKER...BUT WILL STILL HOLD ENOUGH MOISTURE TO DROP ABOUT AN INCH OF QPF IN IT/S DURATION. BY 0Z MONDAY...MUCH OF THE PRECIP SHOULD HAVE MOVED OUT OF THE REGION. HOWEVER...TROPICAL STORM KAREN...MOVING NE FROM THE GULF OF MEXICO...WILL BEGIN MERGING WITH THE LOW PRESSURE SYSTEM. THIS WILL CAUSE THE FRONT TO STALL OUT ONCE MORE ACROSS THE MORE MOUNTAINOUS AREAS TO OUR EAST...WITH HEAVY RAINS EXPECTED. ALTHOUGH THE UPPER LEVEL PATTERN IS IN FAIRLY GOOD AGREEMENT UP UNTIL THIS POINT...BY 0Z MONDAY THE PLACEMENT OF THE UPPER LEVEL TROUGH STARTS TO SHIFT DEPENDING ON THE MODEL. IF IT PASSES JUST A BIT FARTHER NORTH THAN THE OHIO RIVER...ALL RAIN CHANCES WILL CEASE BY 0Z TUESDAY. HOWEVER...IF THE LATEST NAM IS CORRECT...IT WILL TRACK THE LOW JUST A BIT FURTHER SOUTHWARD. ENOUGH TO CAUSE SOME WRAP AROUND MOISTURE ACROSS THE FAR NORTHERN SECTIONS OF THE STATE AS IT STALLS OUT. AT THIS POINT IT SEEMS AS THOUGH THIS WRAP AROUND MOISTURE WILL STAY JUST TO OUR WEST. AS FOR INSTABILITY...FOR THIS AFTERNOON AND TOMORROW AFTERNOON...WILL PROBABLY SEE THE BEST CHANCE FOR ANY ISOLATED TO SCT THUNDERSTORM DEVELOPMENT. HOWEVER SOUNDINGS STILL LOOK WEAK AT BEST FOR THIS TO HAPPEN. AS A RESULT...WILL NOT RULE OUT A FEW RUMBLES OF THUNDER HERE AND THERE WITH ANY SCT SHOWERS...BUT THE MAIN CONCERN WILL STILL BE THE RAINS. AS WAS NOTED BY THE PREVIOUS FORECASTER...THERE IS SOME MID/LEVEL DRYING IN THE LATEST NAM SOUNDINGS...SO SOME WINDY DOWNBURSTS COULD NOT BE OUT OF THE QUESTION. THAT BEING SAID...BY 3Z MONDAY...FORECAST SOUNDINGS SHOW A COMPLETELY SATURATED AIR MASS...LEADING TO THE LOSS OF CONVECTIVE ABILITY AND TURNING TO A MORE STRATIFORM EVENT AS THE MAIN LINE PASSES OVER. DRY AIR WILL FINALLY START TO WORK IN FOR MONDAY MORNING...BRINGING AN END TO ANY LINGERING PRECIP. AS FOR TEMPERATURES...AFTER A WARM START TO TODAY THANKS TO WARM AND MOIST SOUTHERLY FLOW...EXPECT SIMILAR CONDITIONS TOMORROW. THIS WILL HELP TO FURTHER INITIATE ANY SCT CONVECTION OUT AHEAD OF THE MAIN LINE OF SHOWERS. ONCE THE MAIN LINE OF SHOWERS STARTS MOVING INTO THE REGION DURING THE AFTERNOON HOURS...CONTINUOUS RAIN WILL BEGIN DROPPING THE TEMPERATURES FROM WEST TO EAST. AS A RESULT...HIGHS WILL BE MET EARLY ON...REACHING THE HIGHEST VALUES IN THE FAR EAST. ONCE THE FRONT PASSES THROUGH ON MONDAY...COLD AIR WILL FILTER IN BEHIND AND TEMPERATURES WILL START FALLING BEFORE THEY ARE ABLE TO REACH THEIR MAXIMUM POTENTIAL. HIGHS WILL ONLY REACH THE LOW TO MID 60S BY EARLY AFTERNOON BEFORE THEY START DROPPING BACK DOWN. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 245 PM EDT SAT OCT 5 2013 ANY LINGERING SHOWERS IN THE FAR EAST WILL BE ENDING EARLY MONDAY EVENING. THEN WITH THE COLD FRONT WELL TO OUR EAST AND SURFACE HIGH PRESSURE BUILDING INTO THE AREA MONDAY NIGHT WE WILL SEE COOL TEMPERATURES AND DRY WEATHER FOR THE START OF THE FORECAST PERIOD. IN THE WAKE OF THE EXITING UPPER LOW TO OUR NORTHEAST EARLY IN THE WEEK...RESIDUAL TROUGHING WILL GIVE WAY TO RISING HEIGHTS AS UPPER RIDGING GRADUALLY BUILDS INTO THE OH VALLEY. WITH UPPER RIDGING REMAINING OVER THE AREA INTO NEXT WEEKEND AND SURFACE HIGH PRESSURE SHIFTING TO OUR EAST WE WILL SEE SLOWLY WARMING TEMPERATURES AS THE WEEK CONTINUES...ESPECIALLY FOR MAXIMUMS. ALSO THE PATTERN WILL BE CONDUCIVE FOR RIDGE VALLEY TEMPERATURE DIFFERENCES FOR OVERNIGHT MINIMUMS...WITH INCREASING DIURNAL TEMPERATURE RANGES ESPECIALLY IN THE VALLEYS LATER IN THE WEEK. THE COMING WEEK WILL BE DRY WITH THE NEXT CHANCE FOR RAIN HOLDING OFF UNTIL THE APPROACH OF THE NEXT COLD FRONT WHICH IS STILL MORE THAN SEVEN DAYS AWAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 907 PM EDT SAT OCT 5 2013 ACTIVE WEATHER IN THE FORM OF SHOWERS AND THUNDERSTORMS WAS LOOMING JUST TO OUR NW...BUT SHOWERS WERE LEAVING THE JKL FORECAST AREA AS THE FORECAST PERIOD STARTED. CAN NOT RULE OUT SOMETHING SNEAKING INTO OUR NW COUNTIES BEFORE LATE SUNDAY...BUT IT SHOULD BE QUIET MOST OF THE TIME. FOG WILL AFFECT SOME OF THE TYPICALLY FOG PRONE VALLEYS IN THE FAR EASTERN AND SOUTHEASTERN PORTIONS OF THE STATE TONIGHT INTO EARLY SUNDAY MORNING...BUT IS NOT EXPECTED TO HAVE A SIGNIFICANT IMPACT AT TAF SITES. WIDESPREAD PRECIP IS EXPECTED TO BE MOVING INTO THE WESTERN PORTION OF THE FORECAST AREA NEAR THE END OF THE PERIOD...WITH DETERIORATING CONDITIONS WEST OF A LINE FROM SOMERSET TO FLEMINGSBURG BY 00Z SUNDAY EVENING. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HAL SHORT TERM...JMW LONG TERM...SBH AVIATION...HAL
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1229 PM CDT Fri Oct 4 2013 .UPDATE... ISSUED AT 1223 PM CDT FRI OCT 4 2013 Updated the aviation section for the 18Z TAF issuance. && UPDATE ISSUED AT 1109 AM CDT FRI OCT 4 2013 A little uncomfortable broad-brushing PoPs and weather for the remainder of this first period (this afternoon), so went more conservative with the coverage versus intensity of the convective activity. With yesterday`s package, had originally expected the overnight convection to be over southwest Illinois, but it ended up over the lower Wabash valley. In addition, where the stable layer clouds over Southwest Illinois and Southeast Missouri have been noted this morning, expected isolated to widely scattered convection. For today, differential heating and theta-e convergence along and east of the stable cloud layer should aid in convection from noon into the middle of the afternoon. Spatially adjusted HRRR guidance seems to have a decent handle on the main area of convection this afternoon. GOES Lifted index values are falling at or below zero as of 15z, and GOES Precipitable Water values are running around 1.5 inches. This should yield a quick 0.60-0.70 inch hourly amounts in small, but heavy rain showers or thunderstorms this afternoon. && .SHORT TERM...(Today and Tonight) ISSUED AT 406 AM CDT FRI OCT 4 2013 Have just a few light showers over the Evansville Tri State Region early this morning. They are moving northeast and should be out of the area near sunrise. The 00Z models raise 500mb heights across the region and struggle to generate much QPF today. However, with temperatures pushing record levels this afternoon and dewpoints pooling in the upper 60s, will leave a 20-30 PoP for diurnal potential. Any storms this afternoon should dissipate with sunset, leaving the evening dry across the entire region. The 00Z models really do not have a coherent signal on best placement of QPF late tonight through much of Saturday. One fairly common signal is for convective development over southeast Missouri late tonight that then spreads across much of west Kentucky through midday Saturday. This activity would be well ahead of the front. In general, the emphasis would shift to the northwest fringe of the area late in the afternoon, as the primary frontal convective band approaches. This should continue eastward across southeast Missouri and southern Illinois in the evening, as the front pushes eastward across the area. The best signal in the models seems to be that the front will slow down, if not hang up completely, near our eastern border late Saturday night. The 00Z NAM really holds it up, and generates an intense band of QPF over west Kentucky through Sunday morning. It has strong frontogenetical forcing around 925mb along with slightly negative Showalter indices and an extreme amount of moisture to play with, which result in a relatively narrow band of torrential rainfall. The 00Z GFS has similar forcing, but it is more progressive, which seems more realistic given the constant eastward movement of the parent storm system. The 06Z NAM is more progressive. Will cap PoPs at likely levels Saturday and then ramp up to categoricals in the southeast Saturday night and Sunday. The models all have trended slower with the system as a whole, which keeps significant PoPs and QPf over the southeast half of the area through much of Sunday. Even left a sliver of a slight chance in the far east into Sunday evening. Will not mention heavy rain in the grids at this time, due to the likely progressive nature of the heaviest band. If confidence increases in a more prolonged period of heavy rainfall over west Kentucky with subsequent model cycles, a Flash Flood Watch may need to be considered. As for severe weather, instability will be lacking on Saturday due to a general lack of insolation expected. The best wind fields definitely lag the frontal convection, but there may be enough unidirectional shear through the column to support a few line segments within the primary frontal band, mainly into Saturday evening over southeast Missouri and southern Illinois. However, heavy rainfall and frequent lightning will be the bigger concerns Saturday through Sunday. As for temperatures, given that any convection is expected to be diurnal in nature this afternoon, figure the warmer MAV numbers will be closer for highs. The opposite will be true for Saturday, as the cooler MET numbers should be closer to reality. Leaned toward the consensus of raw model data for highs behind the front on Sunday. Lows will be mild tonight, consensus guidance may not be warm enough. Did not stray far from the consensus of raw model data for Saturday nights lows. .LONG TERM...(Monday through Thursday) ISSUED AT 406 AM CDT FRI OCT 4 2013 Surface high pressure will build across the Great Lakes region into the southern plains for the early part of the work week. Dry conditions and cooler than average temperatures can be expected Monday into Monday night, with temperatures moderating back to near seasonal Tuesday into Tuesday night. By Tuesday night into Wednesday night, ECMWF, GEM and GFS all bring an upper level low from the gulf coast states over the eastern U.S. ECMWF and GEM show the track of this low farther west over eastern Kentucky by mid week, while GFS tracks the low farther east along the central Atlantic coast. The ECMWF and GEM show some significant moisture with the low, but keep any precip just east of the PAH forecast area. To account for this, increased cloud cover late Tuesday night through Thursday evening, mainly across our eastern counties. Winds will become southerly for mid to late week as the Great Lakes high moves off the east coast. This will continue the gradual warm up, with readings a few degrees above normal by Thursday. && .AVIATION... ISSUED AT 1223 PM CDT FRI OCT 4 2013 MVFR possible at KCGI for the first couple of hours, otherwise VFR conditions expected at all sites through at least 10Z. Beyond that VCSH/SHRA could easily push cigs and/or vsbys into MVFR territory through the end of the period. South to south southwest winds aob 10 knots should prevail through the period. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ SHORT TERM/FIRE WX...SMITH LONG TERM/AVIATION...JP
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1109 AM CDT Fri Oct 4 2013 .UPDATE... ISSUED AT 1109 AM CDT FRI OCT 4 2013 A little uncomfortable broad-brushing PoPs and weather for the remainder of this first period (this afternoon), so went more conservative with the coverage versus intensity of the convective activity. With yesterday`s package, had originally expected the overnight convection to be over southwest Illinois, but it ended up over the lower Wabash valley. In addition, where the stable layer clouds over Southwest Illinois and Southeast Missouri have been noted this morning, expected isolated to widely scattered convection. For today, differential heating and theta-e convergence along and east of the stable cloud layer should aid in convection from noon into the middle of the afternoon. Spatially adjusted HRRR guidance seems to have a decent handle on the main area of convection this afternoon. GOES Lifted index values are falling at or below zero as of 15z, and GOES Precipitable Water values are running around 1.5 inches. This should yield a quick 0.60-0.70 inch hourly amounts in small, but heavy rain showers or thunderstorms this afternoon. && .SHORT TERM...(Today and Tonight) ISSUED AT 406 AM CDT FRI OCT 4 2013 Have just a few light showers over the Evansville Tri State Region early this morning. They are moving northeast and should be out of the area near sunrise. The 00Z models raise 500mb heights across the region and struggle to generate much QPF today. However, with temperatures pushing record levels this afternoon and dewpoints pooling in the upper 60s, will leave a 20-30 PoP for diurnal potential. Any storms this afternoon should dissipate with sunset, leaving the evening dry across the entire region. The 00Z models really do not have a coherent signal on best placement of QPF late tonight through much of Saturday. One fairly common signal is for convective development over southeast Missouri late tonight that then spreads across much of west Kentucky through midday Saturday. This activity would be well ahead of the front. In general, the emphasis would shift to the northwest fringe of the area late in the afternoon, as the primary frontal convective band approaches. This should continue eastward across southeast Missouri and southern Illinois in the evening, as the front pushes eastward across the area. The best signal in the models seems to be that the front will slow down, if not hang up completely, near our eastern border late Saturday night. The 00Z NAM really holds it up, and generates an intense band of QPF over west Kentucky through Sunday morning. It has strong frontogenetical forcing around 925mb along with slightly negative Showalter indices and an extreme amount of moisture to play with, which result in a relatively narrow band of torrential rainfall. The 00Z GFS has similar forcing, but it is more progressive, which seems more realistic given the constant eastward movement of the parent storm system. The 06Z NAM is more progressive. Will cap PoPs at likely levels Saturday and then ramp up to categoricals in the southeast Saturday night and Sunday. The models all have trended slower with the system as a whole, which keeps significant PoPs and QPf over the southeast half of the area through much of Sunday. Even left a sliver of a slight chance in the far east into Sunday evening. Will not mention heavy rain in the grids at this time, due to the likely progressive nature of the heaviest band. If confidence increases in a more prolonged period of heavy rainfall over west Kentucky with subsequent model cycles, a Flash Flood Watch may need to be considered. As for severe weather, instability will be lacking on Saturday due to a general lack of insolation expected. The best wind fields definitely lag the frontal convection, but there may be enough unidirectional shear through the column to support a few line segments within the primary frontal band, mainly into Saturday evening over southeast Missouri and southern Illinois. However, heavy rainfall and frequent lightning will be the bigger concerns Saturday through Sunday. As for temperatures, given that any convection is expected to be diurnal in nature this afternoon, figure the warmer MAV numbers will be closer for highs. The opposite will be true for Saturday, as the cooler MET numbers should be closer to reality. Leaned toward the consensus of raw model data for highs behind the front on Sunday. Lows will be mild tonight, consensus guidance may not be warm enough. Did not stray far from the consensus of raw model data for Saturday nights lows. .LONG TERM...(Monday through Thursday) ISSUED AT 406 AM CDT FRI OCT 4 2013 Surface high pressure will build across the Great Lakes region into the southern plains for the early part of the work week. Dry conditions and cooler than average temperatures can be expected Monday into Monday night, with temperatures moderating back to near seasonal Tuesday into Tuesday night. By Tuesday night into Wednesday night, ECMWF, GEM and GFS all bring an upper level low from the gulf coast states over the eastern U.S. ECMWF and GEM show the track of this low farther west over eastern Kentucky by mid week, while GFS tracks the low farther east along the central Atlantic coast. The ECMWF and GEM show some significant moisture with the low, but keep any precip just east of the PAH forecast area. To account for this, increased cloud cover late Tuesday night through Thursday evening, mainly across our eastern counties. Winds will become southerly for mid to late week as the Great Lakes high moves off the east coast. This will continue the gradual warm up, with readings a few degrees above normal by Thursday. && .AVIATION... ISSUED AT 638 AM CDT FRI OCT 4 2013 The four state region will be firmly in the warm sector of a developing storm system throughout the 12Z TAF period. Winds will be from the south through the period. Generally light at night, and increasing during the day towards 10kts with some gusts near 15kts possible, especially at KCGI. An area of IFR ceilings over the Ozarks of southeast Missouri will flirt with KCGI for a few hours this morning. Put a prevailing 1kft ceiling in to handle it. May see some isolated convection this afternoon, but the expected coverage is too low to mention the potential in any of the TAFs. A scattered cu layer is expected along with some periodic mid-level ceilings. Guidance has been fairly persistent in generating shra/tsra over southeast Missouri and the Purchase area of west Kentucky late tonight. This may be rather expansive, so will mention the potential in a PROB30 group at KCGI and KPAH. KPAH looks like it will be the most likely to get hit late tonight. There should be enough wind to keep fog from forming at any of the sites late tonight. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...Smith SHORT TERM...DRS LONG TERM...RST AVIATION...DRS
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
513 PM EDT FRI OCT 4 2013 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND THROUGH SATURDAY WHILE A STATIONARY FRONT REMAINS OVER SOUTHERN NEW ENGLAND AND EASTERN NEW YORK STATE. LOW PRESSURE WILL PULL A WARM FRONT NORTH ACROSS THE AREA LATE SUNDAY OR SUNDAY NIGHT...WITH A TRAILING COLD FRONT TO CROSS THE REGION TUESDAY. SOME OF THE MOISTURE FROM THE REMAINS OF TROPICAL STORM KAREN MAY MOVE UP ALONG THIS FRONT. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... UPDATE...A FEW MINOR CHANGES TO KEEP FORECAST IN LINE WITH CURRENT OBSERVATIONAL TRENDS. HAVE TRENDED POP LOWER TO ACCOUNT FOR DRYING IN ASSOCIATION WITH RIDGING OVER NRN ME EATING AWAY AT INCOMING CLOUDS/PCPN. PREVIOUS DISCUSSION...CLOUD SHIELD HAS FINALLY REACHED EASTERN PORTIONS OF THE FORECAST AREA...DESPITE DRY AIR ASSOCIATED WITH SURFACE HIGH PRESSURE OVER NORTHERN NEW ENGLAND. AN AREA OF SHOWERS HAS JUST EXITED THE NH SEACOAST...MUCH IN LINE WITH THE TIMING OF THE LATEST HRRR MODEL. MORE SHOWERS CONTINUE TO DEVELOP OVER QUEBEC PROVINCE AND SLIDE TO THE SOUTH AND EAST. THERE IS STILL A GOOD AMOUNT OF DRY AIR IN THE SOUNDING...HOWEVER A FEW OF THESE SHOWERS MAY SURVIVE THE TRIP THROUGH THE REGION. PLACED A SMALL AREA OF PATCHY LATE NIGHT FOG INTO THE CT RIVER VALLEY TONIGHT. DESPITE CLOUD COVER...SOME FOG MAY DEVELOP IN THE LEBANON AND ADJACENT VALLEY AREAS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... THE BATTLE BETWEEN THE RIDGE TO OUR NORTH AND EAST...AND A STATIONARY FRONT TO OUR SOUTH AND WEST WILL CONTINUE ON SATURDAY AND SATURDAY NIGHT. BY LATE SATURDAY NIGHT...THIS FRONT ADVANCES TOWARDS NORTHERN NEW ENGLAND AS A WARM FRONT. LIMITED MOISTURE MOVING INTO THE RIDGE UNDER A WARM AIR ADVECTION PATTERN MAY BRING A FEW LIGHT SHOWERS TO THE REGION. THE PROBABILITY OF PRECIPITATION WILL INCREASE LATE SATURDAY NIGHT AS THE FRONT APPROACHES. USED A BLEND OF MET/MAV MOS FOR TEMPS THIS PERIOD. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A DIRTY UPPER RIDGE AXIS WILL EXTEND ACROSS NEW ENGLAND BUT A SHORT WAVE MOVES THROUGH ON SUNDAY AS A VERY MOIST ONSHORE SSELY FLOW DEVELOPS ALLOWING OVERRUNNING RAINS TO DEVELOP FROM S-N DURING THE DAY SUNDAY AND CONTINUE SUNDAY NIGHT INTO MON NIGHT AND PSBLY TUE. OVERNIGHT LOWS WILL REMAIN MILD BUT DAYTIME HIGHS WILL REMAIN COOL DUE TO THE ONSHORE FLOW EVEN THO H85 TEMPS WILL BE +12 TO +14C. THE MOISTURE THAT WILL BE ASSOCIATED FROM THE REMNANTS OF KAREN WILL ALSO GET ENTRAINED EARLY NEXT WEEK INTO THE SOUTHERLY FLOW ALOFT SO SOME HEAVY RAINS EXPECTED. BY WED AND THU THE GT LAKES UPR LOW DRIFTS EWD OVER NEW ENGL WITH A COOL CYCLONIC FLOW ALOFT SO A FEW INSTBLTY MAINLY AFTN SHWRS CAN`T BE RULED OUT EACH DAY BUT MAINLY IN THE MTNS. TEMPS TO REMAIN COOL THRU THE END OF THE WEEK DUE TO THE CYCLONIC UPR LOW OVER THE REGION. USED A BLEND OF THE EURO/MAV/MET/MEX GUID FOR THIS PCKG. && .AVIATION /21Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM...CHALLENGING FORECAST FOR TONIGHT IN TERMS OF CLOUD COVER AND POSSIBLE FOG. PLAN ON KEEPING ANY FOG LIMITED TO THE CT RIVER VALLEY...AND ONLY BRIEFLY FOR LATE TONIGHT. LONG TERM...SUN THRU LATE MON MVFR TO IFR CONDS EXPECTED IN RN/SHWRS/PATCHY DRZL. AREAS OF FOG ALG THE COAST WILL DEVELOP SUN NIGHT INTO MON REDUCING CONDS TO LIFR AT KPWM/KPSM/KRKD. IPVG CONDS EXPECTED TO MOSTLY VFR BY MIDWEEK. && .MARINE... SHORT TERM...WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA. LONG TERM...WINDS AND SEAS WILL INCREASE BUT SHOULD REMAIN JUST BELOW SCA CRITERIA THROUGH MIDWEEK. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS GRAY ME
248 PM EDT FRI OCT 4 2013 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND THROUGH SATURDAY WHILE A STATIONARY FRONT REMAINS OVER SOUTHERN NEW ENGLAND AND EASTERN NEW YORK STATE. LOW PRESSURE WILL PULL A WARM FRONT NORTH ACROSS THE AREA LATE SUNDAY OR SUNDAY NIGHT...WITH A TRAILING COLD FRONT TO CROSS THE REGION TUESDAY. SOME OF THE MOISTURE FROM THE REMAINS OF TROPICAL STORM KAREN MAY MOVE UP ALONG THIS FRONT. && .NEAR TERM /THROUGH TONIGHT/... WSR-88D MODE CONFLICT REPAIRED. WE NOW REMAIN IN VCP21 LATE THIS AFTERNOON. CLOUD SHIELD HAS FINALLY REACHED EASTERN PORTIONS OF THE FORECAST AREA...DESPITE DRY AIR ASSOCIATED WITH SURFACE HIGH PRESSURE OVER NORTHERN NEW ENGLAND. AN AREA OF SHOWERS HAS JUST EXITED THE NH SEACOAST...MUCH IN LINE WITH THE TIMING OF THE LATEST HRRR MODEL. MORE SHOWERS CONTINUE TO DEVELOP OVER QUEBEC PROVINCE AND SLIDE TO THE SOUTH AND EAST. THERE IS STILL A GOOD AMOUNT OF DRY AIR IN THE SOUNDING...HOWEVER A FEW OF THESE SHOWERS MAY SURVIVE THE TRIP THROUGH THE REGION. PLACED A SMALL AREA OF PATCHY LATE NIGHT FOG INTO THE CT RIVER VALLEY TONIGHT. DESPITE CLOUD COVER...SOME FOG MAY DEVELOP IN THE LEBANON AND ADJACENT VALLEY AREAS. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... THE BATTLE BETWEEN THE RIDGE TO OUR NORTH AND EAST...AND A STATIONARY FRONT TO OUR SOUTH AND WEST WILL CONTINUE ON SATURDAY AND SATURDAY NIGHT. BY LATE SATURDAY NIGHT...THIS FRONT ADVANCES TOWARDS NORTHERN NEW ENGLAND AS A WARM FRONT. LIMITED MOISTURE MOVING INTO THE RIDGE UNDER A WARM AIR ADVECTION PATTERN MAY BRING A FEW LIGHT SHOWERS TO THE REGION. THE PROBABILITY OF PRECIPITATION WILL INCREASE LATE SATURDAY NIGHT AS THE FRONT APPROACHES. USED A BLEND OF MET/MAV MOS FOR TEMPS THIS PERIOD. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A DIRTY UPPER RIDGE AXIS WILL EXTEND ACROSS NEW ENGLAND BUT A SHORT WAVE MOVES THROUGH ON SUNDAY AS A VERY MOIST ONSHORE SSELY FLOW DEVELOPS ALLOWING OVERUNNING RAINS TO DEVELOP FROM S-N DURING THE DAY SUNDAY AND CONTINUE SUNDAY NIGHT INTO MON NIGHT AND PSBLY TUE. OVERNIGHT LOWS WILL REMAIN MILD BUT DAYTIME HIGHS WILL REMAIN COOL DUE TO THE ONSHORE FLOW EVEN THO H85 TEMPS WILL BE +12 TO +14C. THE MOISTURE THAT WILL BE ASSOCIATED FROM THE REMNANTS OF KAREN WILL ALSO GET ENTRAINED EARLY NEXT WEEK INTO THE SOUTHERLY FLOW ALOFT SO SOME HEAVY RAINS EXPECTED. BY WED AND THU THE GT LAKES UPR LOW DRIFTS EWD OVER NEW ENGL WITH A COOL CYCLONIC FLOW ALOFT SO A FEW INSTBLTY MAINLY AFTN SHWRS CAN`T BE RULED OUT EACH DAY BUT MAINLY IN THE MTNS. TEMPS TO REMAIN COOL THRU THE END OF THE WEEK DUE TO THE CYCLONIC UPR LOW OVER THE REGION. USED A BLEND OF THE EURO/MAV/MET/MEX GUID FOR THIS PCKG. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... SHORT TERM...CHALLENGING FORECAST FOR TONIGHT IN TERMS OF CLOUD COVER AND POSSIBLE FOG. PLAN ON KEEPING ANY FOG LIMITED TO THE CT RIVER VALLEY...AND ONLY BRIEFLY FOR LATE TONIGHT. LONG TERM...SUN THRU LATE MON MVFR TO IFR CONDS EXPECTED IN RN/SHWRS/PATCHY DRZL. AREAS OF FOG ALG THE COAST WILL DEVELOP SUN NIGHT INTO MON REDUCING CONDS TO LIFR AT KPWM/KPSM/KRKD. IPVG CONDS EXPECTED TO MOSTLY VFR BY MIDWEEK. && .MARINE... SHORT TERM...WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA. LONG TERM...WINDS AND SEAS WILL INCREASE BUT SHOULD REMAIN JUST BELOW SCA CRITERIA THROUGH MIDWEEK. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAY ME
1222 PM EDT FRI OCT 4 2013 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND THROUGH SATURDAY. LOW PRESSURE WILL PULL A WARM FRONT NORTH ACROSS THE AREA LATE SUNDAY OR SUNDAY NIGHT, WITH A TRAILING COLD FRONT TO CROSS THE REGION MONDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... HAVE UPDATED GRIDS TO INCREASE POPS FURTHER FOR SOUTHERN NEW HAMPSHIRE AND EXTREME SOUTHWEST MAINE FOR EARLY THIS AFTERNOON. HAVE ALSO INCREASED CLOUD GRIDS FOR MUCH OF THE AREA BASED ON LATEST STLT IMAGES AND SURFACE OBSERVATIONS. LATEST HRRR MODEL BRINGS AN AREA OF PRECIPITATION EASTWARD...FROM ABOUT PORTLAND AND POINTS SOUTH THIS AFTERNOON. SOME OF THIS PRECIPITATION MAY NOT REACH THE GROUND AS A RIDGE OF HIGH PRESSURE CONTINUES TO ENTER MAINE FROM QUEBEC PROVINCE. PREV DISC... UPDATED FORECAST TO ADD SLGT CHC OR CHC -SHRA TO SRN MOST ZONES PER LATEST RADAR TRENDS...OTRW NO NOTICEABLE CHANGES TO THE PREVIOUS FORECAST. WEAK HIGH PRES OVER THE REGION TODAY GIVES US FAIR DRY WX WITH MILD TEMPS. THERE WILL BE SOME MID TO HIGH LVL CLOUDS AROUND DUE TO MOISTURE ALOFT MOVING THRU WITH A WEAK UPPER LEVEL SHORT WAVE TROF THAT HAS LIMITED SUPPORT TO PRODUCE ANY PRCP AS IT WEAKENS WHILE MOVING THRU THE BROAD UPPER LEVEL RIDGE OVER THE EASTERN US. AREAS OF VALLEY FOG...MAINLY ACROSS NRN AND WRN NH SHOULD LIFT SHORTLY AFTER SUNRISE. HIGHS EXPECTED TO REACH THE 60S N AND 70 TO 75 SOUTH THOUGH A DEVELOPING ONSHORE SEA BREEZE WILL LIKELY COOL OFF COASTAL TOWNS A BIT THIS AFTERNOON. GENERALLY USED A BLEND OF GFS/NAM AND MET/MAV MOS GUIDANCE ALONG WITH HPC QPF. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... WEAK HIGH PRES REMAINS IN CONTROL TNGT AND SATURDAY AS THE UPPER LEVEL RIDGE STRENGTHENS OVER THE NE AS THE WEAKENING SHORT WAVE TROF MOVES OFF TO THE EAST. STILL SOME CLOUDS LINGER DUE TO TRAPPED MOISTURE UNDER THE SUBSIDENCE FROM HIGH PRES PUSHING IN FROM THE NW. THIS WILL KEEP TEMPS FROM GETTING REAL COLD TNGT... STILL SHOULD COOL DOWN INTO THE MID 30S TO LOWER 40S N AND INTO THE 40S TO AROUND 50 S. CLOUDS WILL LIKELY HELP HOLD OFF ANY FOG FORMING OVERNIGHT. MORE CLOUDS AROUND ON SATURDAY DESPITE THE HIGH OVERHEAD AS A FRONTAL BOUNDARY TO OUR S BEGINS TO PUSH N SPREADING HIGH AND MID LVL CLOUDS NORTHWARD. SHOULD BE MILD THOUGH CLOUDS WILL HOLD TEMPS DOWN A BIT. STILL LOOKING FOR HIGHS IN THE LOWER TO MID 60S N AND MID 60S TO AROUND 70 SOUTH. && .LONG TERM /SUNDAY THROUGH THURSDAY/... WE BEGIN THE PERIOD WITH MILD WEATHER UNDER A SHORT WAVE RIDGE. BY MONDAY...A SHORT WAVE TROUGH ARRIVES FROM THE GREAT LAKES AND DRIVES A SURFACE COLD FRONT ACROSS THE FORECAST AREA. IN THE WAKE OF THE FRONTAL PASSAGE...WE STAY A BIT UNSETTLED THROUGH LATE WEEK AS AN UPPER TROUGH LINGERS ACROSS THE REGION. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH SATURDAY/...DESPITE LOTS OF HIGH AND MID LVL CLOUDS TODAY WITH SOME LOWER OF CIG TNGT INTO SATURDAY IT SHOULD BE VFR THRU THE SHORT TERM EXCEPT FOR AREAS OF VALLEY FOG THAT WILL MOST LIKELY IMPACT LEB AND MAYBE HIE EARLY THIS MORNING. LONG TERM... SUN NIGHT - MON...AREAS OF MVFR IN SHOWERS. && .MARINE... SHORT TERM /TODAY THROUGH SATURDAY/...UPDATED FORECAST TO INPUT LATEST OBSERVED DATA RESULTING IN NO NOTICEABLE CHANGES TO THE PREVIOUS FORECAST. HIGH PRESSURE KEEPS WINDS AND SEAS WELL BELOW SCA LEVELS THRU SATURDAY. LONG TERM... SUN NIGHT - MON...SMALL CRAFT WINDS AND SEAS ARE LIKELY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAY ME
1124 AM EDT FRI OCT 4 2013 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND THROUGH SATURDAY. LOW PRESSURE WILL PULL A WARM FRONT NORTH ACROSS THE AREA LATE SUNDAY OR SUNDAY NIGHT, WITH A TRAILING COLD FRONT TO CROSS THE REGION MONDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... HAVE UPDATED GRIDS TO INCREASE POPS FURTHER FOR SOUTHERN NEW HAMPSHIRE AND EXTREME SOUTHWEST MAINE FOR LATER THIS MORNING. LATEST HRRR MODEL BRINGS AN AREA OF PRECIPITATION EASTWARD...FROM ABOUT PORTLAND AND POINTS SOUTH LATER THIS MORNING AND EARLY THIS AFTERNOON. SOME OF THIS PRECIPITATION MAY NOT REACH THE GROUND AS A RIDGE OF HIGH PRESSURE CONTINUES TO ENTER MAINE FROM QUEBEC PROVINCE. PREV DISC... UPDATED FORECAST TO ADD SLGT CHC OR CHC -SHRA TO SRN MOST ZONES PER LATEST RADAR TRENDS...OTRW NO NOTICEABLE CHANGES TO THE PREVIOUS FORECAST. WEAK HIGH PRES OVER THE REGION TODAY GIVES US FAIR DRY WX WITH MILD TEMPS. THERE WILL BE SOME MID TO HIGH LVL CLOUDS AROUND DUE TO MOISTURE ALOFT MOVING THRU WITH A WEAK UPPER LEVEL SHORT WAVE TROF THAT HAS LIMITED SUPPORT TO PRODUCE ANY PRCP AS IT WEAKENS WHILE MOVING THRU THE BROAD UPPER LEVEL RIDGE OVER THE EASTERN US. AREAS OF VALLEY FOG...MAINLY ACROSS NRN AND WRN NH SHOULD LIFT SHORTLY AFTER SUNRISE. HIGHS EXPECTED TO REACH THE 60S N AND 70 TO 75 SOUTH THOUGH A DEVELOPING ONSHORE SEA BREEZE WILL LIKELY COOL OFF COASTAL TOWNS A BIT THIS AFTERNOON. GENERALLY USED A BLEND OF GFS/NAM AND MET/MAV MOS GUIDANCE ALONG WITH HPC QPF. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... WEAK HIGH PRES REMAINS IN CONTROL TNGT AND SATURDAY AS THE UPPER LEVEL RIDGE STRENGTHENS OVER THE NE AS THE WEAKENING SHORT WAVE TROF MOVES OFF TO THE EAST. STILL SOME CLOUDS LINGER DUE TO TRAPPED MOISTURE UNDER THE SUBSIDENCE FROM HIGH PRES PUSHING IN FROM THE NW. THIS WILL KEEP TEMPS FROM GETTING REAL COLD TNGT... STILL SHOULD COOL DOWN INTO THE MID 30S TO LOWER 40S N AND INTO THE 40S TO AROUND 50 S. CLOUDS WILL LIKELY HELP HOLD OFF ANY FOG FORMING OVERNIGHT. MORE CLOUDS AROUND ON SATURDAY DESPITE THE HIGH OVERHEAD AS A FRONTAL BOUNDARY TO OUR S BEGINS TO PUSH N SPREADING HIGH AND MID LVL CLOUDS NORTHWARD. SHOULD BE MILD THOUGH CLOUDS WILL HOLD TEMPS DOWN A BIT. STILL LOOKING FOR HIGHS IN THE LOWER TO MID 60S N AND MID 60S TO AROUND 70 SOUTH. && .LONG TERM /SUNDAY THROUGH THURSDAY/... WE BEGIN THE PERIOD WITH MILD WEATHER UNDER A SHORT WAVE RIDGE. BY MONDAY...A SHORT WAVE TROUGH ARRIVES FROM THE GREAT LAKES AND DRIVES A SURFACE COLD FRONT ACROSS THE FORECAST AREA. IN THE WAKE OF THE FRONTAL PASSAGE...WE STAY A BIT UNSETTLED THROUGH LATE WEEK AS AN UPPER TROUGH LINGERS ACROSS THE REGION. && .AVIATION /16Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH SATURDAY/...DESPITE LOTS OF HIGH AND MID LVL CLOUDS TODAY WITH SOME LOWER OF CIG TNGT INTO SATURDAY IT SHOULD BE VFR THRU THE SHORT TERM EXCEPT FOR AREAS OF VALLEY FOG THAT WILL MOST LIKELY IMPACT LEB AND MAYBE HIE EARLY THIS MORNING. LONG TERM... SUN NIGHT - MON...AREAS OF MVFR IN SHOWERS. && .MARINE... SHORT TERM /TODAY THROUGH SATURDAY/...UPDATED FORECAST TO INPUT LATEST OBSERVED DATA RESULTING IN NO NOTICEABLE CHANGES TO THE PREVIOUS FORECAST. HIGH PRESSURE KEEPS WINDS AND SEAS WELL BELOW SCA LEVELS THRU SATURDAY. LONG TERM... SUN NIGHT - MON...SMALL CRAFT WINDS AND SEAS ARE LIKELY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$
AREA FORECAST DISCUSSION
NWS GRAY ME
839 AM EDT FRI OCT 4 2013 .SYNOPSIS... WEAK HIGH PRESSURE WILL REMAIN OVER NEW ENGLAND THROUGH SATURDAY. LOW PRESSURE WILL PULL A WARM FRONT NORTH ACROSS THE AREA LATE SUNDAY OR SUNDAY NIGHT, WITH A TRAILING COLD FRONT TO CROSS THE REGION MONDAY. && .NEAR TERM /THROUGH TONIGHT/... UPDATE... HAVE UPDATED GRIDS TO INCREASE POPS FURTHER FOR SOUTHERN NEW HAMPSHIRE AND EXTREME SOUTHWEST MAINE FOR LATER THIS MORNING. LATEST HRRR MODEL BRINGS AN AREA OF PRECIPITATION EASTWARD...FROM ABOUT PORTLAND AND POINTS SOUTH LATER THIS MORNING AND EARLY THIS AFTERNOON. SOME OF THIS PRECIPITATION MAY NOT REACH THE GROUND AS A RIDGE OF HIGH PRESSURE CONTINUES TO ENTER MAINE FROM QUEBEC PROVINCE. PREV DISC... UPDATED FORECAST TO ADD SLGT CHC OR CHC -SHRA TO SRN MOST ZONES PER LATEST RADAR TRENDS...OTRW NO NOTICEABLE CHANGES TO THE PREVIOUS FORECAST. WEAK HIGH PRES OVER THE REGION TODAY GIVES US FAIR DRY WX WITH MILD TEMPS. THERE WILL BE SOME MID TO HIGH LVL CLOUDS AROUND DUE TO MOISTURE ALOFT MOVING THRU WITH A WEAK UPPER LEVEL SHORT WAVE TROF THAT HAS LIMITED SUPPORT TO PRODUCE ANY PRCP AS IT WEAKENS WHILE MOVING THRU THE BROAD UPPER LEVEL RIDGE OVER THE EASTERN US. AREAS OF VALLEY FOG...MAINLY ACROSS NRN AND WRN NH SHOULD LIFT SHORTLY AFTER SUNRISE. HIGHS EXPECTED TO REACH THE 60S N AND 70 TO 75 SOUTH THOUGH A DEVELOPING ONSHORE SEA BREEZE WILL LIKELY COOL OFF COASTAL TOWNS A BIT THIS AFTERNOON. GENERALLY USED A BLEND OF GFS/NAM AND MET/MAV MOS GUIDANCE ALONG WITH HPC QPF. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... WEAK HIGH PRES REMAINS IN CONTROL TNGT AND SATURDAY AS THE UPPER LEVEL RIDGE STRENGTHENS OVER THE NE AS THE WEAKENING SHORT WAVE TROF MOVES OFF TO THE EAST. STILL SOME CLOUDS LINGER DUE TO TRAPPED MOISTURE UNDER THE SUBSIDENCE FROM HIGH PRES PUSHING IN FROM THE NW. THIS WILL KEEP TEMPS FROM GETTING REAL COLD TNGT... STILL SHOULD COOL DOWN INTO THE MID 30S TO LOWER 40S N AND INTO THE 40S TO AROUND 50 S. CLOUDS WILL LIKELY HELP HOLD OFF ANY FOG FORMING OVERNIGHT. MORE CLOUDS AROUND ON SATURDAY DESPITE THE HIGH OVERHEAD AS A FRONTAL BOUNDARY TO OUR S BEGINS TO PUSH N SPREADING HIGH AND MID LVL CLOUDS NORTHWARD. SHOULD BE MILD THOUGH CLOUDS WILL HOLD TEMPS DOWN A BIT. STILL LOOKING FOR HIGHS IN THE LOWER TO MID 60S N AND MID 60S TO AROUND 70 SOUTH. && .LONG TERM /SUNDAY THROUGH THURSDAY/... WE BEGIN THE PERIOD WITH MILD WEATHER UNDER A SHORT WAVE RIDGE. BY MONDAY...A SHORT WAVE TROUGH ARRIVES FROM THE GREAT LAKES AND DRIVES A SURFACE COLD FRONT ACROSS THE FORECAST AREA. IN THE WAKE OF THE FRONTAL PASSAGE...WE STAY A BIT UNSETTLED THROUGH LATE WEEK AS AN UPPER TROUGH LINGERS ACROSS THE REGION. && .AVIATION /13Z FRIDAY THROUGH TUESDAY/... SHORT TERM /THROUGH SATURDAY/...DESPITE LOTS OF HIGH AND MID LVL CLOUDS TODAY WITH SOME LOWER OF CIG TNGT INTO SATURDAY IT SHOULD BE VFR THRU THE SHORT TERM EXCEPT FOR AREAS OF VALLEY FOG THAT WILL MOST LIKELY IMPACT LEB AND MAYBE HIE EARLY THIS MORNING. LONG TERM... SUN NIGHT - MON...AREAS OF MVFR IN SHOWERS. && .MARINE... SHORT TERM /TODAY THROUGH SATURDAY/...UPDATED FORECAST TO INPUT LATEST OBSERVED DATA RESULTING IN NO NOTICEABLE CHANGES TO THE PREVIOUS FORECAST. HIGH PRESSURE KEEPS WINDS AND SEAS WELL BELOW SCA LEVELS THRU SATURDAY. LONG TERM... SUN NIGHT - MON...SMALL CRAFT WINDS AND SEAS ARE LIKELY. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...NONE. NH...NONE. MARINE...NONE. && $$ JC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 PM EDT FRI OCT 4 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 533 AM EDT FRI OCT 4 2013 TODAY...LATEST 09Z WATER VAPOR LOOP AND RUC ANALYSIS SHOW A SHORTWAVE EXITING UPPER MI. MODELS INDICATE DNVA AND A TRANSITION TO Q-VECT DIV IN THE WAKE OF THIS SHORTWAVE FOR THE REST OF THE OVERNIGHT INTO MUCH OF DAY TODAY. THESE FACTORS ALONG WITH A LOSS OF ANY MEANINGFUL WAA/ISENTROPIC ASCENT INTO AT LEAST EARLY AFTERNOON SHOULD ALLOW ANY LINGERING SHRA TO DIE OUT TOWARD SUNRISE. ALREADY SEEING A DIMINISHING TREND ON SHRA IN PAST HR OR TWO. EXPECT MUCH OF TODAY TO STAY MOSTLY DRY AS MODELS INDICATE SHORTWAVE RDGG AND 5H HEIGHT RISES OVER THE AREA IN RESPONSE TO POTENT STORM SYSTEM SLOWLY ADVANCING FROM THE SRN/CNTRL PLAINS. THUS...HAVE DRASTICALLY TRIMMED POPS BACK TO JUST SLIGHT CHC FOR MUCH OF THE FCST AREA. BROUGHT IN LOW CHC (30 PCT) POPS LATE IN THE DAY ALONG THE WI BORDER AS WAA DOES BEGIN TO INCREASE FROM THE SW. TONIGHT...THE MODELS WERE IN REASONABLE AGREEMENT SHOWING INCREASING 300-310K ISENTROPIC ASCENT SPREADING FROM WEST TO EAST FROM LATE EVENING INTO THE OVERNIGHT HRS TONIGHT IN RESPONSE TO CONTINUED SLOW ADVANCE OF STORM SYSTEM THROUGH THE CENTRAL PLAINS. AS A RESULT...I HAVE SLOWLY BROUGHT BACK LIKELY TO CATEGORICAL POPS FROM WEST TO EAST MAINLY BETWEEN 06-12Z LATE TONIGHT. THERE MAY BE A PERIOD OF HEAVY RAIN GIVEN THE FAVORABLE MOISTURE TRANSPORT AND PWAT VALUES TO AROUND 1.5 INCHES. HOWEVER...CONVECTION SHOULD BE LIMITED AS BEST MODEL MUCAPE VALUES AND NEGATIVE SHOWALTER INDICES STAY SOUTH TONIGHT. EXPECT PCPN AMOUNTS GEENRALLY IN THE 0.20 TO 0.60 INCH RANGE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 533 AM EDT FRI OCT 4 2013 NAM SHOWS A CLOSED 500 MB LOW OVER SD 12Z SAT WITH A RIDGE OVER THE SERN U.S. WITH A RIDGE OVER THE WESTERN U.S. THIS CLOSED LOW WILL CONTINUE TO MOVE SLOWLY EASTWARD THROUGH THE PERIOD THROUGH THE UPPER GREAT LAKES. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE WITH SOME DEEPER MOISTURE MOVING THROUGH THE CWA WITH A DRY SLOT MOVING THROUGH ON SUNDAY. NAM SHOWS SOME ISENTROPIC LIFT AND MOISTURE ON I300K-I315K SURFACES 12Z SAT WITH THE DRY SLOT MOVING IN ON SUNDAY. LOOKS LIKE A DECENT WIDESPREAD RAIN EVENT FOR THIS FORECAST PERIOD AND WENT CATEGORICAL POPS ON SAT WITH A DRY SLOT MOVING THROUGH ON SUN. KEPT IN SOME THUNDER CHANCES FOR SAT AND SAT NIGHT. WRAPAROUND MOISTURE COMES INTO THE WEST ON SUN AND WENT CHANCE POPS THEN. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT RAISED LOW TEMPERATURES SAT NIGHT A COUPLE DEGREES AS THEY LOOKED TOO COLD. MAIN REASON IS NOT SURE THAT THE DRY SLOT WILL ALLOW CLEARING IN THE LOWEST LEVELS FOR CLOUDS AND COLDER AIR DOES NOT ARRIVE UNTIL SUN. IN THE EXTENDED...UPPER AIR PATTERN CONSISTS OF A 500 TROUGH OVER THE EASTERN HALF OF THE U.S. WITH A RIDGE OVER THE ROCKIES 12Z MON. THE RIDGE MOVES INTO THE PLAINS 12Z TUE WITH A TROUGH OVER THE WESTERN U.S. THE TROUGH STAYS PUT 12Z WED WITH RIDGING OVER THE GREAT LAKES REGION WHICH STAYS INTO THU. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL THROUGH THE PERIOD WITH UPPER RIDGING ALLOWING DRY WEATHER TO CONTINUE. KEPT IN SLIGHT CHANCE POPS FOR MON AS UPPER TROUGH MOVES AWAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 139 PM EDT FRI OCT 4 2013 HAVE WORSENING CONDITIONS THROUGH THE PERIOD AS A WARM FROM LIFTS N INTO THE AREA TONIGHT INTO SATURDAY. WILL SEE PRECIPITATION MOVE IN AT SOME POINT...BUT THAT IS FAIRLY UNCERTAIN. HOWEVER...WENT WITH BEST GUESS FOR PRECIP TIMING IN THE TAFS. DID NOT LOWER VIS TOO MUCH AS RAIN SHOULD BE MORE OF A STEADY RAIN...ALTHOUGH IT COULD BE HEAVIER AT TIMES REDUCING VISIBILITIES FURTHER...BUT WAS TOO UNCERTAIN TO GET INTO THESE DETAILS AT THIS TIME. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 533 AM EDT FRI OCT 4 2013 EXPECT EAST-NORTHEAST WINDS 15 TO 25 KTS EARLY THIS MORNING TO INCREASE TO 20 TO 30 KT WITH A FEW GALE GUSTS OVER FAR WESTERN LAKE SUPERIOR. LOOK FOR NE WINDS WILL INCREASE TO GALES TO 35 KTS OVER FAR WRN LAKE SUPERIOR LATE TONIGHT/EARLY SATURDAY MORNING AND THEN CONTINUE THROUGH SATURDAY EVENING. WINDS WILL THEN DIMINISH SAT NIGHT/SUN AS THE LOW LIFTS ACROSS THE UPPER GREAT LAKES. DEPENDING ON THE STRENGTH OF THE SFC LOW AS IT PASSES...WILL NEED TO WATCH FOR A PERIOD OF STRONGER NW WINDS ON THE BACKSIDE OF THE SYSTEM SUNDAY NIGHT INTO MON. WINDS WILL BE LIGHT MON NIGHT INTO TUESDAY AS HIGH PRESSURE MOVES OVER THE AREA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 5 PM EDT /4 PM CDT/ THIS AFTERNOON TO 2 AM EDT /1 AM CDT/ SUNDAY FOR LSZ162. GALE WARNING FROM 11 PM THIS EVENING TO 11 PM EDT SATURDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...07 AVIATION...TITUS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
741 AM EDT FRI OCT 4 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 533 AM EDT FRI OCT 4 2013 TODAY...LATEST 09Z WATER VAPOR LOOP AND RUC ANALYSIS SHOW A SHORTWAVE EXITING UPPER MI. MODELS INDICATE DNVA AND A TRANSITION TO Q-VECT DIV IN THE WAKE OF THIS SHORTWAVE FOR THE REST OF THE OVERNIGHT INTO MUCH OF DAY TODAY. THESE FACTORS ALONG WITH A LOSS OF ANY MEANINGFUL WAA/ISENTROPIC ASCENT INTO AT LEAST EARLY AFTERNOON SHOULD ALLOW ANY LINGERING SHRA TO DIE OUT TOWARD SUNRISE. ALREADY SEEING A DIMINISHING TREND ON SHRA IN PAST HR OR TWO. EXPECT MUCH OF TODAY TO STAY MOSTLY DRY AS MODELS INDICATE SHORTWAVE RDGG AND 5H HEIGHT RISES OVER THE AREA IN RESPONSE TO POTENT STORM SYSTEM SLOWLY ADVANCING FROM THE SRN/CNTRL PLAINS. THUS...HAVE DRASTICALLY TRIMMED POPS BACK TO JUST SLIGHT CHC FOR MUCH OF THE FCST AREA. BROUGHT IN LOW CHC (30 PCT) POPS LATE IN THE DAY ALONG THE WI BORDER AS WAA DOES BEGIN TO INCREASE FROM THE SW. TONIGHT...THE MODELS WERE IN REASONABLE AGREEMENT SHOWING INCREASING 300-310K ISENTROPIC ASCENT SPREADING FROM WEST TO EAST FROM LATE EVENING INTO THE OVERNIGHT HRS TONIGHT IN RESPONSE TO CONTINUED SLOW ADVANCE OF STORM SYSTEM THROUGH THE CENTRAL PLAINS. AS A RESULT...I HAVE SLOWLY BROUGHT BACK LIKELY TO CATEGORICAL POPS FROM WEST TO EAST MAINLY BETWEEN 06-12Z LATE TONIGHT. THERE MAY BE A PERIOD OF HEAVY RAIN GIVEN THE FAVORABLE MOISTURE TRANSPORT AND PWAT VALUES TO AROUND 1.5 INCHES. HOWEVER...CONVECTION SHOULD BE LIMITED AS BEST MODEL MUCAPE VALUES AND NEGATIVE SHOWALTER INDICES STAY SOUTH TONIGHT. EXPECT PCPN AMOUNTS GEENRALLY IN THE 0.20 TO 0.60 INCH RANGE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 533 AM EDT FRI OCT 4 2013 NAM SHOWS A CLOSED 500 MB LOW OVER SD 12Z SAT WITH A RIDGE OVER THE SERN U.S. WITH A RIDGE OVER THE WESTERN U.S. THIS CLOSED LOW WILL CONTINUE TO MOVE SLOWLY EASTWARD THROUGH THE PERIOD THROUGH THE UPPER GREAT LAKES. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE WITH SOME DEEPER MOISTURE MOVING THROUGH THE CWA WITH A DRY SLOT MOVING THROUGH ON SUNDAY. NAM SHOWS SOME ISENTROPIC LIFT AND MOISTURE ON I300K-I315K SURFACES 12Z SAT WITH THE DRY SLOT MOVING IN ON SUNDAY. LOOKS LIKE A DECENT WIDESPREAD RAIN EVENT FOR THIS FORECAST PERIOD AND WENT CATEGORICAL POPS ON SAT WITH A DRY SLOT MOVING THROUGH ON SUN. KEPT IN SOME THUNDER CHANCES FOR SAT AND SAT NIGHT. WRAPAROUND MOISTURE COMES INTO THE WEST ON SUN AND WENT CHANCE POPS THEN. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT RAISED LOW TEMPERATURES SAT NIGHT A COUPLE DEGREES AS THEY LOOKED TOO COLD. MAIN REASON IS NOT SURE THAT THE DRY SLOT WILL ALLOW CLEARING IN THE LOWEST LEVELS FOR CLOUDS AND COLDER AIR DOES NOT ARRIVE UNTIL SUN. IN THE EXTENDED...UPPER AIR PATTERN CONSISTS OF A 500 TROUGH OVER THE EASTERN HALF OF THE U.S. WITH A RIDGE OVER THE ROCKIES 12Z MON. THE RIDGE MOVES INTO THE PLAINS 12Z TUE WITH A TROUGH OVER THE WESTERN U.S. THE TROUGH STAYS PUT 12Z WED WITH RIDGING OVER THE GREAT LAKES REGION WHICH STAYS INTO THU. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL THROUGH THE PERIOD WITH UPPER RIDGING ALLOWING DRY WEATHER TO CONTINUE. KEPT IN SLIGHT CHANCE POPS FOR MON AS UPPER TROUGH MOVES AWAY. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 737 AM EDT FRI OCT 4 2013 AS SFC WARM FNT TO THE S EDGES VERY SLOWLY TOWARD UPR MI...EXPECT A TREND FM VFR TO MVFR CIGS AT IWD AND SAW LATER THIS MORNING. THE ARRIVAL OF MORE NMRS SHRA AT IWD AND SAW MAY CAUSE CIGS TO FALL TO IFR LATE THIS EVENING AND OVERNIGHT RESPECTIVELY. CMX IS LIKELY TO REMAIN VFR UNTIL PREVAILING SHRA LOWERS CIGS TO MVFR LATE TONIGHT. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 533 AM EDT FRI OCT 4 2013 EXPECT EAST-NORTHEAST WINDS 15 TO 25 KTS EARLY THIS MORNING TO INCREASE TO 20 TO 30 KT WITH A FEW GALE GUSTS OVER FAR WESTERN LAKE SUPERIOR. LOOK FOR NE WINDS WILL INCREASE TO GALES TO 35 KTS OVER FAR WRN LAKE SUPERIOR LATE TONIGHT/EARLY SATURDAY MORNING AND THEN CONTINUE THROUGH SATURDAY EVENING. WINDS WILL THEN DIMINISH SAT NIGHT/SUN AS THE LOW LIFTS ACROSS THE UPPER GREAT LAKES. DEPENDING ON THE STRENGTH OF THE SFC LOW AS IT PASSES...WILL NEED TO WATCH FOR A PERIOD OF STRONGER NW WINDS ON THE BACKSIDE OF THE SYSTEM SUNDAY NIGHT INTO MON. WINDS WILL BE LIGHT MON NIGHT INTO TUESDAY AS HIGH PRESSURE MOVES OVER THE AREA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 4 AM EDT /3 AM CDT/ SATURDAY TO 2 AM EDT /1 AM CDT/ SUNDAY FOR LSZ162. GALE WARNING FROM 4 AM TO 11 PM EDT SATURDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...07 AVIATION...VOSS MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
533 AM EDT FRI OCT 4 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 533 AM EDT FRI OCT 4 2013 TODAY...LATEST 09Z WATER VAPOR LOOP AND RUC ANALYSIS SHOW A SHORTWAVE EXITING UPPER MI. MODELS INDICATE DNVA AND A TRANSITION TO Q-VECT DIV IN THE WAKE OF THIS SHORTWAVE FOR THE REST OF THE OVERNIGHT INTO MUCH OF DAY TODAY. THESE FACTORS ALONG WITH A LOSS OF ANY MEANINGFUL WAA/ISENTROPIC ASCENT INTO AT LEAST EARLY AFTERNOON SHOULD ALLOW ANY LINGERING SHRA TO DIE OUT TOWARD SUNRISE. ALREADY SEEING A DIMINISHING TREND ON SHRA IN PAST HR OR TWO. EXPECT MUCH OF TODAY TO STAY MOSTLY DRY AS MODELS INDICATE SHORTWAVE RDGG AND 5H HEIGHT RISES OVER THE AREA IN RESPONSE TO POTENT STORM SYSTEM SLOWLY ADVANCING FROM THE SRN/CNTRL PLAINS. THUS...HAVE DRASTICALLY TRIMMED POPS BACK TO JUST SLIGHT CHC FOR MUCH OF THE FCST AREA. BROUGHT IN LOW CHC (30 PCT) POPS LATE IN THE DAY ALONG THE WI BORDER AS WAA DOES BEGIN TO INCREASE FROM THE SW. TONIGHT...THE MODELS WERE IN REASONABLE AGREEMENT SHOWING INCREASING 300-310K ISENTROPIC ASCENT SPREADING FROM WEST TO EAST FROM LATE EVENING INTO THE OVERNIGHT HRS TONIGHT IN RESPONSE TO CONTINUED SLOW ADVANCE OF STORM SYSTEM THROUGH THE CENTRAL PLAINS. AS A RESULT...I HAVE SLOWLY BROUGHT BACK LIKELY TO CATEGORICAL POPS FROM WEST TO EAST MAINLY BETWEEN 06-12Z LATE TONIGHT. THERE MAY BE A PERIOD OF HEAVY RAIN GIVEN THE FAVORABLE MOISTURE TRANSPORT AND PWAT VALUES TO AROUND 1.5 INCHES. HOWEVER...CONVECTION SHOULD BE LIMITED AS BEST MODEL MUCAPE VALUES AND NEGATIVE SHOWALTER INDICES STAY SOUTH TONIGHT. EXPECT PCPN AMOUNTS GEENRALLY IN THE 0.20 TO 0.60 INCH RANGE. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 533 AM EDT FRI OCT 4 2013 NAM SHOWS A CLOSED 500 MB LOW OVER SD 12Z SAT WITH A RIDGE OVER THE SERN U.S. WITH A RIDGE OVER THE WESTERN U.S. THIS CLOSED LOW WILL CONTINUE TO MOVE SLOWLY EASTWARD THROUGH THE PERIOD THROUGH THE UPPER GREAT LAKES. NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE WITH SOME DEEPER MOISTURE MOVING THROUGH THE CWA WITH A DRY SLOT MOVING THROUGH ON SUNDAY. NAM SHOWS SOME ISENTROPIC LIFT AND MOISTURE ON I300K-I315K SURFACES 12Z SAT WITH THE DRY SLOT MOVING IN ON SUNDAY. LOOKS LIKE A DECENT WIDESPREAD RAIN EVENT FOR THIS FORECAST PERIOD AND WENT CATEGORICAL POPS ON SAT WITH A DRY SLOT MOVING THROUGH ON SUN. KEPT IN SOME THUNDER CHANCES FOR SAT AND SAT NIGHT. WRAPAROUND MOISTURE COMES INTO THE WEST ON SUN AND WENT CHANCE POPS THEN. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST EXCEPT RAISED LOW TEMPERATURES SAT NIGHT A COUPLE DEGREES AS THEY LOOKED TOO COLD. MAIN REASON IS NOT SURE THAT THE DRY SLOT WILL ALLOW CLEARING IN THE LOWEST LEVELS FOR CLOUDS AND COLDER AIR DOES NOT ARRIVE UNTIL SUN. IN THE EXTENDED...UPPER AIR PATTERN CONSISTS OF A 500 TROUGH OVER THE EASTERN HALF OF THE U.S. WITH A RIDGE OVER THE ROCKIES 12Z MON. THE RIDGE MOVES INTO THE PLAINS 12Z TUE WITH A TROUGH OVER THE WESTERN U.S. THE TROUGH STAYS PUT 12Z WED WITH RIDGING OVER THE GREAT LAKES REGION WHICH STAYS INTO THU. TEMPERATURES WILL CONTINUE TO BE ABOVE NORMAL THROUGH THE PERIOD WITH UPPER RIDGING ALLOWING DRY WEATHER TO CONTINUE. KEPT IN SLIGHT CHANCE POPS FOR MON AS UPPER TROUGH MOVES AWAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 131 AM EDT FRI OCT 4 2013 AS SFC WARM FNT TO THE S EDGES VERY SLOWLY TOWARD UPR MI...EXPECT A TREND FM VFR TO MVFR CIGS AT IWD. SAW HAS ALREADY SEEN CIGS LOWER TO MVFR. THE ARRIVAL OF MORE NMRS SHRA AT IWD LATER IN THE TAF TIME MAY CAUSE CIGS LATER THIS EVNG TO FALL TO IFR THERE. CMX IS LIKELY TO REMAIN FAR ENUF N THAT CONDITIONS REMAIN VFR THERE THRU THE PERIOD. && .MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 533 AM EDT FRI OCT 4 2013 EXPECT EAST-NORTHEAST WINDS 15 TO 25 KTS EARLY THIS MORNING TO INCREASE TO 20 TO 30 KT WITH A FEW GALE GUSTS OVER FAR WESTERN LAKE SUPERIOR. LOOK FOR NE WINDS WILL INCREASE TO GALES TO 35 KTS OVER FAR WRN LAKE SUPERIOR LATE TONIGHT/EARLY SATURDAY MORNING AND THEN CONTINUE THROUGH SATURDAY EVENING. WINDS WILL THEN DIMINISH SAT NIGHT/SUN AS THE LOW LIFTS ACROSS THE UPPER GREAT LAKES. DEPENDING ON THE STRENGTH OF THE SFC LOW AS IT PASSES...WILL NEED TO WATCH FOR A PERIOD OF STRONGER NW WINDS ON THE BACKSIDE OF THE SYSTEM SUNDAY NIGHT INTO MON. WINDS WILL BE LIGHT MON NIGHT INTO TUESDAY AS HIGH PRESSURE MOVES OVER THE AREA. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WARNING FROM 4 AM EDT /3 AM CDT/ SATURDAY TO 2 AM EDT /1 AM CDT/ SUNDAY FOR LSZ162. GALE WARNING FROM 4 AM TO 11 PM EDT SATURDAY FOR LSZ263. LAKE MICHIGAN... NONE. && $$ SHORT TERM...VOSS LONG TERM...07 AVIATION...KC MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
139 AM EDT FRI OCT 4 2013 .UPDATE... ISSUED AT 831 PM EDT THU OCT 3 2013 LATEST SHORTER TERM NUMERICAL MODELS HAVE A POOR HANDLE ON AREA OF SHRA MOVING NEWD INTO UPR MI FM WI IN ASSOCIATION WITH SHRTWV LIFTING NEWD THRU NW WI PER LATEST WV IMAGERY. OPTED TO BUMP UP POPS THRU LATE EVNG FOR MUCH OF THE CWA PER THE LATEST RUC FCST FAIRLY VIGOROUS H7-3 QVECTOR CNVGC/UPR DVGC AHEAD OF THIS SHRTWV. STILL EXPECT THE SHRA TO DIMINISH WITH TIME AS THE RUC SHOWS AREA OF QVECTOR CNVGC/UPR DVGC WEAKENING BY 06Z AS THE PRECIP AREA RUNS INTO DRIER AIR TO THE NE. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 452 PM EDT THU OCT 3 2013 THE SHORT TERM WILL BE DOMINATED BY STRENGTHENING LOW PRESSURE OVER THE PLAINS AS A 500MB LOW OVER ID MOVES TO WRN NE BY 00Z SAT. AT THE SFC...THERE IS CURRENTLY A LOW LEEWARD OF THE CO ROCKIES...WITH A SFC TROUGH/WARM FRONT EXTENDING INTO SRN WI AND LOWER MI. SHOWERS AND THUNDERSTORMS HAVE BEEN MOVING ALONG THE SFC WARM FRONT TODAY...WHILE PRECIP LAST NIGHT MOVED PRIMARILY ALONG THE 850MB WARM FRONT/TROUGH THAT EXTENDS OVER THE CWA. ADDITIONAL SHOWERS AND THUNDERSTORMS HAVE FORMED ALONG THE FROM...BUT MOISTURE TRANSPORT WILL BE BEST OVER FAR WRN LAKE SUPERIOR DUE TO BLOCKING OF MOISTURE TRANSPORT OVER THE REST OF THE CWA BY PRECIP TO THE S. THINK THE CURRENT PRECIP OVER SRN/CENTRAL WI WILL STAY FOCUSED ALONG THE SFC WARM FRONT AND STAY TO THE S...MAYBE BRUSHING THE SCENTRAL CWA. VERY TRICKY FORECAST THROUGH 00Z SAT AS MODELS ARE HAVING A HARD TIME WITH THE CURRENT AND FORECAST CONVECTION. THE WARM FRONTS WILL STAY NEARLY STATIONARY...WITH CONVECTION FIRING ALONG THE SFC WARM FRONT TO THE S AS THE LLJ KICKS IN. THIS CONVECTION SHOULD BLOCK MOISTURE TRANSPORT INTO MUCH OF THE CWA TONIGHT...KEEPING PRECIP SUPPRESSED ALONG THE 850MB WARM FRONT. MODELS GENERALLY AGREE WITH THIS IN SHOWING EITHER NO TO VERY LITTLE PRECIP TONIGHT...OR A QUICK MOVING BAND OF PRECIP THAT MAY MOVE ACROSS THE CWA. WITH THE SFC LOW DEEPENING TO AROUND 1000MB AS IT MOVES TO FAR ERN NE BY 00Z SAT...THE WARM FRONT WILL MOVE SLIGHTLY N/NW. THINK THAT BEST CHANCES FOR PRECIP WILL BE OVER THE WRN CWA CLOSER TO THE 850MB WARM FRONT WHERE THE BEST MOISTURE TRANSPORT IS LOCATED. STILL FAIRLY UNCERTAIN WITH PRECIP PLACEMENT GIVEN MODEL DISAGREEMENT...SO BROAD BRUSHED POPS. NE WINDS PICK UP /ESPECIALLY OVER THE GREAT LAKES/ FRI AFTERNOON/EVENING AS THE PRESSURE GRADIENT OVER THE REGION INCREASES. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 452 PM EDT THU OCT 3 2013 FRIDAY NIGHT...THE MODELS WERE IN REASONABLE AGREEMENT WITH THE MID LEVEL LOW MOVING INTO SE SD AND THE SFC LOW/TROUGH INTO SRN MN BY 12Z/SAT. CATEGORICAL PCPN CHANCES LOOK ON TRACK FRIDAY NIGHT WITH 300K-310K ISENTROPIC ALONG AND NORTH OF THE 850 MB WARM FRONT BRINGING WIDESPREAD RAIN THROUGH UPPER MI. ALTHOUGH THEIR MAY BE A PERIOD OF HEAVY RAIN GIVEN THE FAVORABLE MOISTURE TRANSPORT AND PWAT VALUES TO AROUND 1.5 INCHES...THE AREA OF STRONGEST OF LIFT IS EXPECTED TO MAKE STEADY PROGRESS TO THE NNE. CONVECTION SHOULD ALSO BE LIMITED WITH FCST MUCAPE VALUES ONLY TO AROUND 400 J/KG OVER THE SRN PORTION OF THE CWA. PCPN AMOUNTS IN THE 0.50 TO 0.75 INCH RANGE ARE EXPECTED. SAT INTO SAT NIGHT...THE MODELS BEGIN TO DIVERGE WITH THE GFS/GEFS/GEM/UKMET REMAINING FASTER WITH THE MID/SFC LOW MOVEMENT COMPARED TO THE ECMWF. UNCERTAINTY IS GREATER...BUT THE FCST WAS TRENDED MORE TOWARD THE GFS/GEM/UKMET. ALTHOUGH THE MORE WIDESPREAD PCPN IS EXPECTED TO DEPART EARLY...LIKELY POPS REMAIN THROUGH THE DAY WITH 700-300 MB QVECTOR CONV AHEAD OF THE MID LEVEL LOW SUPPORTED SCT/NMRS SHRA AND A FEW ELEVATED TSRA IN THE 850 MB WARM SECTOR...ESPECIALLY OVER THE WEST. PCPN CHANCES WILL DIMINISH SATURDAY NIGHT AS THE DRY SLOT MOVES INTO THE AREA. SUN INTO MON...EXPECT SOME -SHRA TO LINGER WITH DEFORMATION/COMMA HEAD MOISTURE/PCPN WRAPPING AROUND THE BACKSIDE OF MID LEVEL LOW. LOW LEVEL CYCLONIC FLOW AND 850MB TEMPS FALLING TO -2C TO 2C ALSO SUGGEST POTENTIAL OF SCT LAKE ENHANCED -SHRA BEHIND THE SYSTEM FOR LOCATIONS FAVORED BY WNW FLOW. ALTHOUGH THE DEEPER MOISTURE AND ASSOCIATED PCPN CHANCES WITH THE STORM SYSTEM MOVE OUT SUN NIGHT WITH THE FASTER GFS/GEM/UKMET...LOWER END PCPN CHANCES LINGER INTO MON OVER MAINLY THE NORTH WITH THE POSSIBILITY OF A TRAILING CLIPPER SHORTWAVE BRUSHING THE AREA. DRY WEATHER WILL THEN FOLLOW TUE THROUGH THU AS A TROF DEEPENING OVER THE ROCKIES/WRN PLAINS ALLOWS A BROAD MID-LVL RIDGE TO BUILD INTO THE GREAT LAKES REGION. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 131 AM EDT FRI OCT 4 2013 AS SFC WARM FNT TO THE S EDGES VERY SLOWLY TOWARD UPR MI...EXPECT A TREND FM VFR TO MVFR CIGS AT IWD. SAW HAS ALREADY SEEN CIGS LOWER TO MVFR. THE ARRIVAL OF MORE NMRS SHRA AT IWD LATER IN THE TAF TIME MAY CAUSE CIGS LATER THIS EVNG TO FALL TO IFR THERE. CMX IS LIKELY TO REMAIN FAR ENUF N THAT CONDITIONS REMAIN VFR THERE THRU THE PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 452 PM EDT THU OCT 3 2013 GENERALLY LIGHT EAST-NORTHEAST WINDS AHEAD OF AN APPROACHING WARM FRONT WILL INCREASE TO 15 TO 25 KTS LATE TODAY AND TONIGHT...WITH THE HIGHEST GUSTS ACROSS WESTERN LAKE SUPERIOR. WINDS WILL INCREASE FURTHER TO 20-30 KTS FRI THRU SAT AS SFC LOW PRES SLOWLY LIFTS TOWARD THE UPPER GREAT LAKES. A BRIEF PERIOD OF GALES TO 35 KTS MAY OCCUR FRI NIGHT AND EARLY SAT MORNING OVER WRN LAKE SUPERIOR. WINDS WILL THEN DIMINISH SAT NIGHT/SUN AS THE LOW LIFTS ACROSS THE UPPER GREAT LAKES. DEPENDING ON THE STRENGTH OF THE SFC LOW AS IT PASSES...WILL NEED TO WATCH FOR A PERIOD OF STRONGER WINDS ON THE BACKSIDE OF THE SYSTEM LATER SUN INTO EARLY MON. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... GALE WATCH FROM THIS EVENING THROUGH SATURDAY MORNING FOR LSZ162- 263-264. LAKE MICHIGAN... NONE. && $$ UPDATE...KC SHORT TERM...TITUS LONG TERM...JLB AVIATION...KC MARINE...TITUS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1053 PM CDT SAT OCT 5 2013 .SYNOPSIS... ISSUED AT 315 PM CDT SAT OCT 5 2013 OCCLUDED AND VERTICALLY STACKED LOW WAS SPINNING OVER SOUTHEAST SODAK THIS AFTERNOON. AN OCCLUDED FRONT AT THE SFC STRETCHES FROM NEAR AXN...DOWN TO THE NRN TWIN CITIES METRO AND SOUTHEAST FROM THERE TO A TRIPLE POINT IN SW WISCONSIN. THIS LOW HAS STARTED TO SLIP ESE TOWARD SW MN THIS AFTERNOON. THIS IS ALLOWING THE BLIZZARD THAT HAS BEEN RAGING FOR THE BETTER PART OF 3 DAYS ACROSS THE NRN HIGH PLAINS TO SLOWLY WIND DOWN TODAY...WITH AN IMPRESSIVE BANK OF SNOW SHOWING UP ON VIS SATELLITE THIS AFTERNOON ACROSS WYOMING INTO WRN NEB/SODAK. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 315 PM CDT SAT OCT 5 2013 STRONG MID LEVEL JET HAS ROUNDED THE BASE OF THE STACKED LOW OVER SODAK TODAY. THIS HAS HELPED ENHANCE MID-LEVEL TEMP GRADIENTS ACROSS THE AREA. THIS HAS RESULTED IN AN ENHANCED AREA OF FGEN DEVELOPING IN THE H7 TO H5 LAYER...MIX IN SOME ADIABATIC OMEGA ON THE 305K SFC AND YOU GET THE DEVELOPING BAND OF SHOWERS ACROSS THE TWIN CITIES METRO AT 300 PM. THE HRRR ALONG WITH THE HOPWRF HAVE BEEN CONSISTENT IN DEVELOPING THIS FEATURE ALL DAY...SO FOLLOWED THESE MODELS CLOSELY TO MOVE THIS BAND OF PRECIP THROUGH ERN AND CENTRAL MN AND WRN WI THIS EVENING INTO TONIGHT. STILL HAVE BEST LI/S BETWEEN 0 AND -2 OVER WRN WI..SO HAVE SOME ISO THUNDER WORDING IN THE EAST THIS AFTERNOON. THIS ALSO MATCHES UP WELL WITH WHERE THE HRRR IS DEVELOPING MORE ROBUST CONVECTION. THOUGH WE ARE NOT EXPECTING ANY SEVERE WEATHER...COOLER TEMPERATURES ALOFT MOVING IN FROM THE SOUTHWEST HAS RESULTED IN SOME GRAUPEL/SMALL HAIL BEING REPORTED THIS AFTERNOON...WHICH WILL CONTINUE TO BE THE CASE THROUGH THIS EVENING BEFORE WE LOOSE THE CONVECTIVE ASPECT OF THE PRECIP AND IT BECOMES MAINLY STRATIFORM. FOR TONIGHT...THE BIG QUESTION IS WHETHER OR NOT SKIES TRY TO CLEAR OUT AGAIN ACROSS THE SOUTH AS THE DEVELOPING PRECIP BAND MOVES INTO CENTRAL MN AND NW WI. TO SOME EXTENT...THE NAM/ECMWF/GFS ALL SHOW SKIES CLEARING OUT TONIGHT FOR AT LEAST A PERIOD FROM SRN MN INTO WRN WI. THE NAM IS THE MOST AGGRESSIVE WITH THIS...WITH LOWS DOWN INTO THE 30S FROM SOUTH CENTRAL MN UP INTO WRN WI. BESIDE THE COOLER TEMPS...IF SKIES DO CLEAR OUT LIKE THAT...THEN THOSE CLEAR SKIES WOULD LIKELY FILL IN WITH DENSE FOG...SO THAT WILL NEED TO BE WATCHED AS WE GO THROUGH THE NIGHT. FOR SUNDAY...THINGS ARE LOOKING UP WEATHER WISE FOR THE TWIN CITIES MARATHON IN THE MORNING...AS PRECIP LOOKS TO HOLD OFF IN THE TWIN CITIES UNTIL THE AFTERNOON. BY 12Z THE LOW WILL HAVE FILLED IN TO THE POINT WHERE IT WILL BE A RATHER BROAD AREA OF LOW PRESSURE EXTENDING FROM SW MN UP INTO THE WRN UP OF MICH. COLD CONVEYOR BELT PRECIP BY SUNDAY MORNING WILL STRETCH ACROSS NRN WI ACROSS CENTRAL/NRN MN...THEN DOWN ACROSS THE ERN DAKOTAS...ALMOST WRAPPING AROUND THE MPX AREA. AS SFC AND UPPER AIR FEATURES DRIFT TOWARD THE GREAT LAKES DURING THE DAY...THE WRN EDGE OF THE PRECIP WILL BEGIN MOVING ACROSS THE AREA. USED A BLEND OF THE GEM/NAM/SREF TO BRING THIS PRECIP BACK EAST ACROSS THE AREA SUNDAY...THIS RESULTED IN A SLOWING OF THE EWD PROGRESSION OF POPS TOMORROW. IN FACT...MOST OF THE 12Z GUIDANCE KEEPS PRECIP THROUGH 7 PM SUNDAY EVENING WEST OF WISCONSIN...SO A FURTHER SLOWING IN POP GRIDS MAY BE NEEDED TONIGHT. OTHER CHANGE FOR SUNDAY WAS TO LOWER TEMPS A BIT...ESPECIALLY ACROSS MN. WITH MOSTLY CLOUDY CONDITIONS EXPECTED TO PREVAIL...WILL BE A STRUGGLE FOR MUCH OF THE MN AREA TO CRACK 50 FOR HIGHS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT SAT OCT 5 2013 AS THE SHORT TERM MENTIONED...THE UPPER LOW CONTINUES TO SLOW AND LOW POPS REMAIN IN PLACE OVER ERN/SRN MN AND WRN WI INTO SUNDAY NIGHT. CLEARING WILL GRADUALLY TAKE PLACE AND IT IS POSSIBLE TO GET AREAS OF FOG BY MONDAY MORNING DEPENDING ON TIMING OF CLEARING AND STRENGTH OF WIND. ANOTHER LONG STRETCH OF LATE SUMMER WEATHER WILL TAKE HOLD NEXT WEEK...PARTICULARLY TUESDAY ONWARD AS A DIGGING WEST COAST TROUGH LEADS TO A LARGE RIDGE BUILDING EASTWARD ACROSS THE PLAINS. STRONG RETURN FLOW AND GUSTY SOUTH WINDS TUESDAY WILL EASE MID/LATE WEEK AS A BAGGIER PRESSURE PATTERN DEVELOPS UNDER THE RIDGE. 925 MB TEMPS REACH THE MID/UPPER TEENS CELSIUS FOR MUCH OF NEXT WEEK...BRINGING HIGHS FIRMLY INTO THE 70S. GUIDANCE IS IN STRONG AGREEMENT FOR MID 70S...INCLUDING THE CLIMATOLOGICALLY FAVORING MOS PRODUCT AT EXTENDED RANGES. HIGHS AND LOWS WILL BE ABOUT 15 DEGREES ABOVE AVERAGE WITH NEARLY UNRESTRICTED SUNSHINE EACH DAY THROUGH THURSDAY. ANOTHER POTENT STORM SYSTEM WILL DEVELOP TO THE LEE OF THE ROCKIES THURSDAY NIGHT AND TRACK NORTHWARD INTO THE DAKOTAS FRIDAY NIGHT. THIS SHOULD KEEP THE MAJORITY OF THE AREA DRY THROUGH FRIDAY BEFORE THE COLD FRONT SWINGS THROUGH FRIDAY NIGHT. OVERALL...THE GFS AND ECMWF REMAIN IN RATHER GOOD AGREEMENT SO FORECAST CONFIDENCE IS HIGH THROUGHOUT THE LONG TERM PERIOD. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1053 PM CDT SAT OCT 5 2013 A FRONTAL BOUNDARY ARCS FROM NEAR KAXN TO KEAU LATE THIS EVENING WITH SHOWERS NOW NORTH AND EAST OF THE TAF SITES. ALTHOUGH VFR CEILINGS ARE CURRENTLY IN PLACE AT THE TAF SITES...LOW MVFR/IFR SHOULD BEGIN FILLING IN NEAR THE BOUNDARY IN THE 06Z-08Z TIME FRAME. THIS WOULD PRIMARILY AFFECT KAXN...KSTC...KRNH AND KEAU. THE LOW CEILINGS WILL THEN PERSIST THROUGH MUCH OF SUNDAY. CONFIDENCE NOT AS HIGH ON MVFR OR LOWER CEILINGS DEVELOPING AT KMSP BY 08Z WITH A TEMPO GROUP USED INSTEAD OF A PREDOMINATE GROUP. KRWF WILL BE OVC035-045 OVERNIGHT WITH SOME POTENTIAL FOR MVFR CEILINGS NEAR DAYBREAK WITH A BETTER CHANCE FOR THE MVFR CEILINGS AND SOME LIGHT RAIN ON SUNDAY AS A TROUGH AXIS MOVES THROUGH. LIGHT AND VARIABLE WINDS OVERNIGHT BECOMING NW 10-15 KNOTS WITH SOME GUSTS TO 20 KNOTS FOR THE MN TAF SITES. KMSP...A NW-SE ORIENTATED DRY SLOT COVERS THE TWIN CITIES LATE THIS EVENING WITH FEW-SCT CLOUDS. CONCERN OVERNIGHT IS THE POTENTIAL FOR LOW MVFR/IFR CEILINGS TO DEVELOP AS WELL AS SOME MVFR OR LOWER BR/FG. CONFIDENCE IS NOT HIGH ON EITHER ONE EARLY ON WITH CHANCES INCREASING TOWARDS DAYBREAK. MVFR CEILINGS ON SUNDAY WITH SOME SPRINKLES IN THE AFTERNOON. IMPROVEMENT BACK TO VFR SUNDAY EVENING. /OUTLOOK FOR KMSP/ MON...VFR. WINDS NW 5-10 KT. TUE...VFR. WINDS S15G25 KT. WED...VFR. WINDS SSE 10-15 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SYNOPSIS...MPG SHORT TERM...MPG LONG TERM...BORGHOFF AVIATION...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
654 PM CDT SAT OCT 5 2013 .SYNOPSIS... ISSUED AT 315 PM CDT SAT OCT 5 2013 OCCLUDED AND VERTICALLY STACKED LOW WAS SPINNING OVER SOUTHEAST SODAK THIS AFTERNOON. AN OCCLUDED FRONT AT THE SFC STRETCHES FROM NEAR AXN...DOWN TO THE NRN TWIN CITIES METRO AND SOUTHEAST FROM THERE TO A TRIPLE POINT IN SW WISCONSIN. THIS LOW HAS STARTED TO SLIP ESE TOWARD SW MN THIS AFTERNOON. THIS IS ALLOWING THE BLIZZARD THAT HAS BEEN RAGING FOR THE BETTER PART OF 3 DAYS ACROSS THE NRN HIGH PLAINS TO SLOWLY WIND DOWN TODAY...WITH AN IMPRESSIVE BANK OF SNOW SHOWING UP ON VIS SATELLITE THIS AFTERNOON ACROSS WYOMING INTO WRN NEB/SODAK. .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 315 PM CDT SAT OCT 5 2013 STRONG MID LEVEL JET HAS ROUNDED THE BASE OF THE STACKED LOW OVER SODAK TODAY. THIS HAS HELPED ENHANCE MID-LEVEL TEMP GRADIENTS ACROSS THE AREA. THIS HAS RESULTED IN AN ENHANCED AREA OF FGEN DEVELOPING IN THE H7 TO H5 LAYER...MIX IN SOME ADIABATIC OMEGA ON THE 305K SFC AND YOU GET THE DEVELOPING BAND OF SHOWERS ACROSS THE TWIN CITIES METRO AT 300 PM. THE HRRR ALONG WITH THE HOPWRF HAVE BEEN CONSISTENT IN DEVELOPING THIS FEATURE ALL DAY...SO FOLLOWED THESE MODELS CLOSELY TO MOVE THIS BAND OF PRECIP THROUGH ERN AND CENTRAL MN AND WRN WI THIS EVENING INTO TONIGHT. STILL HAVE BEST LI/S BETWEEN 0 AND -2 OVER WRN WI..SO HAVE SOME ISO THUNDER WORDING IN THE EAST THIS AFTERNOON. THIS ALSO MATCHES UP WELL WITH WHERE THE HRRR IS DEVELOPING MORE ROBUST CONVECTION. THOUGH WE ARE NOT EXPECTING ANY SEVERE WEATHER...COOLER TEMPERATURES ALOFT MOVING IN FROM THE SOUTHWEST HAS RESULTED IN SOME GRAUPEL/SMALL HAIL BEING REPORTED THIS AFTERNOON...WHICH WILL CONTINUE TO BE THE CASE THROUGH THIS EVENING BEFORE WE LOOSE THE CONVECTIVE ASPECT OF THE PRECIP AND IT BECOMES MAINLY STRATIFORM. FOR TONIGHT...THE BIG QUESTION IS WHETHER OR NOT SKIES TRY TO CLEAR OUT AGAIN ACROSS THE SOUTH AS THE DEVELOPING PRECIP BAND MOVES INTO CENTRAL MN AND NW WI. TO SOME EXTENT...THE NAM/ECMWF/GFS ALL SHOW SKIES CLEARING OUT TONIGHT FOR AT LEAST A PERIOD FROM SRN MN INTO WRN WI. THE NAM IS THE MOST AGGRESSIVE WITH THIS...WITH LOWS DOWN INTO THE 30S FROM SOUTH CENTRAL MN UP INTO WRN WI. BESIDE THE COOLER TEMPS...IF SKIES DO CLEAR OUT LIKE THAT...THEN THOSE CLEAR SKIES WOULD LIKELY FILL IN WITH DENSE FOG...SO THAT WILL NEED TO BE WATCHED AS WE GO THROUGH THE NIGHT. FOR SUNDAY...THINGS ARE LOOKING UP WEATHER WISE FOR THE TWIN CITIES MARATHON IN THE MORNING...AS PRECIP LOOKS TO HOLD OFF IN THE TWIN CITIES UNTIL THE AFTERNOON. BY 12Z THE LOW WILL HAVE FILLED IN TO THE POINT WHERE IT WILL BE A RATHER BROAD AREA OF LOW PRESSURE EXTENDING FROM SW MN UP INTO THE WRN UP OF MICH. COLD CONVEYOR BELT PRECIP BY SUNDAY MORNING WILL STRETCH ACROSS NRN WI ACROSS CENTRAL/NRN MN...THEN DOWN ACROSS THE ERN DAKOTAS...ALMOST WRAPPING AROUND THE MPX AREA. AS SFC AND UPPER AIR FEATURES DRIFT TOWARD THE GREAT LAKES DURING THE DAY...THE WRN EDGE OF THE PRECIP WILL BEGIN MOVING ACROSS THE AREA. USED A BLEND OF THE GEM/NAM/SREF TO BRING THIS PRECIP BACK EAST ACROSS THE AREA SUNDAY...THIS RESULTED IN A SLOWING OF THE EWD PROGRESSION OF POPS TOMORROW. IN FACT...MOST OF THE 12Z GUIDANCE KEEPS PRECIP THROUGH 7 PM SUNDAY EVENING WEST OF WISCONSIN...SO A FURTHER SLOWING IN POP GRIDS MAY BE NEEDED TONIGHT. OTHER CHANGE FOR SUNDAY WAS TO LOWER TEMPS A BIT...ESPECIALLY ACROSS MN. WITH MOSTLY CLOUDY CONDITIONS EXPECTED TO PREVAIL...WILL BE A STRUGGLE FOR MUCH OF THE MN AREA TO CRACK 50 FOR HIGHS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT SAT OCT 5 2013 AS THE SHORT TERM MENTIONED...THE UPPER LOW CONTINUES TO SLOW AND LOW POPS REMAIN IN PLACE OVER ERN/SRN MN AND WRN WI INTO SUNDAY NIGHT. CLEARING WILL GRADUALLY TAKE PLACE AND IT IS POSSIBLE TO GET AREAS OF FOG BY MONDAY MORNING DEPENDING ON TIMING OF CLEARING AND STRENGTH OF WIND. ANOTHER LONG STRETCH OF LATE SUMMER WEATHER WILL TAKE HOLD NEXT WEEK...PARTICULARLY TUESDAY ONWARD AS A DIGGING WEST COAST TROUGH LEADS TO A LARGE RIDGE BUILDING EASTWARD ACROSS THE PLAINS. STRONG RETURN FLOW AND GUSTY SOUTH WINDS TUESDAY WILL EASE MID/LATE WEEK AS A BAGGIER PRESSURE PATTERN DEVELOPS UNDER THE RIDGE. 925 MB TEMPS REACH THE MID/UPPER TEENS CELSIUS FOR MUCH OF NEXT WEEK...BRINGING HIGHS FIRMLY INTO THE 70S. GUIDANCE IS IN STRONG AGREEMENT FOR MID 70S...INCLUDING THE CLIMATOLOGICALLY FAVORING MOS PRODUCT AT EXTENDED RANGES. HIGHS AND LOWS WILL BE ABOUT 15 DEGREES ABOVE AVERAGE WITH NEARLY UNRESTRICTED SUNSHINE EACH DAY THROUGH THURSDAY. ANOTHER POTENT STORM SYSTEM WILL DEVELOP TO THE LEE OF THE ROCKIES THURSDAY NIGHT AND TRACK NORTHWARD INTO THE DAKOTAS FRIDAY NIGHT. THIS SHOULD KEEP THE MAJORITY OF THE AREA DRY THROUGH FRIDAY BEFORE THE COLD FRONT SWINGS THROUGH FRIDAY NIGHT. OVERALL...THE GFS AND ECMWF REMAIN IN RATHER GOOD AGREEMENT SO FORECAST CONFIDENCE IS HIGH THROUGHOUT THE LONG TERM PERIOD. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 315 PM CDT SAT OCT 5 2013 STRONG MID LEVEL JET HAS ROUNDED THE BASE OF THE STACKED LOW OVER SODAK TODAY. THIS HAS HELPED ENHANCE MID-LEVEL TEMP GRADIENTS ACROSS THE AREA. THIS HAS RESULTED IN AN ENHANCED AREA OF FGEN DEVELOPING IN THE H7 TO H5 LAYER...MIX IN SOME ADIABATIC OMEGA ON THE 305K SFC AND YOU GET THE DEVELOPING BAND OF SHOWERS ACROSS THE TWIN CITIES METRO AT 300 PM. THE HRRR ALONG WITH THE HOPWRF HAVE BEEN CONSISTENT IN DEVELOPING THIS FEATURE ALL DAY...SO FOLLOWED THESE MODELS CLOSELY TO MOVE THIS BAND OF PRECIP THROUGH ERN AND CENTRAL MN AND WRN WI THIS EVENING INTO TONIGHT. STILL HAVE BEST LI/S BETWEEN 0 AND -2 OVER WRN WI..SO HAVE SOME ISO THUNDER WORDING IN THE EAST THIS AFTERNOON. THIS ALSO MATCHES UP WELL WITH WHERE THE HRRR IS DEVELOPING MORE ROBUST CONVECTION. THOUGH WE ARE NOT EXPECTING ANY SEVERE WEATHER...COOLER TEMPERATURES ALOFT MOVING IN FROM THE SOUTHWEST HAS RESULTED IN SOME GRAUPEL/SMALL HAIL BEING REPORTED THIS AFTERNOON...WHICH WILL CONTINUE TO BE THE CASE THROUGH THIS EVENING BEFORE WE LOOSE THE CONVECTIVE ASPECT OF THE PRECIP AND IT BECOMES MAINLY STRATIFORM. FOR TONIGHT...THE BIG QUESTION IS WHETHER OR NOT SKIES TRY TO CLEAR OUT AGAIN ACROSS THE SOUTH AS THE DEVELOPING PRECIP BAND MOVES INTO CENTRAL MN AND NW WI. TO SOME EXTENT...THE NAM/ECMWF/GFS ALL SHOW SKIES CLEARING OUT TONIGHT FOR AT LEAST A PERIOD FROM SRN MN INTO WRN WI. THE NAM IS THE MOST AGGRESSIVE WITH THIS...WITH LOWS DOWN INTO THE 30S FROM SOUTH CENTRAL MN UP INTO WRN WI. BESIDE THE COOLER TEMPS...IF SKIES DO CLEAR OUT LIKE THAT...THEN THOSE CLEAR SKIES WOULD LIKELY FILL IN WITH DENSE FOG...SO THAT WILL NEED TO BE WATCHED AS WE GO THROUGH THE NIGHT. FOR SUNDAY...THINGS ARE LOOKING UP WEATHER WISE FOR THE TWIN CITIES MARATHON IN THE MORNING...AS PRECIP LOOKS TO HOLD OFF IN THE TWIN CITIES UNTIL THE AFTERNOON. BY 12Z THE LOW WILL HAVE FILLED IN TO THE POINT WHERE IT WILL BE A RATHER BROAD AREA OF LOW PRESSURE EXTENDING FROM SW MN UP INTO THE WRN UP OF MICH. COLD CONVEYOR BELT PRECIP BY SUNDAY MORNING WILL STRETCH ACROSS NRN WI ACROSS CENTRAL/NRN MN...THEN DOWN ACROSS THE ERN DAKOTAS...ALMOST WRAPPING AROUND THE MPX AREA. AS SFC AND UPPER AIR FEATURES DRIFT TOWARD THE GREAT LAKES DURING THE DAY...THE WRN EDGE OF THE PRECIP WILL BEGIN MOVING ACROSS THE AREA. USED A BLEND OF THE GEM/NAM/SREF TO BRING THIS PRECIP BACK EAST ACROSS THE AREA SUNDAY...THIS RESULTED IN A SLOWING OF THE EWD PROGRESSION OF POPS TOMORROW. IN FACT...MOST OF THE 12Z GUIDANCE KEEPS PRECIP THROUGH 7 PM SUNDAY EVENING WEST OF WISCONSIN...SO A FURTHER SLOWING IN POP GRIDS MAY BE NEEDED TONIGHT. OTHER CHANGE FOR SUNDAY WAS TO LOWER TEMPS A BIT...ESPECIALLY ACROSS MN. WITH MOSTLY CLOUDY CONDITIONS EXPECTED TO PREVAIL...WILL BE A STRUGGLE FOR MUCH OF THE MN AREA TO CRACK 50 FOR HIGHS. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 315 PM CDT SAT OCT 5 2013 AS THE SHORT TERM MENTIONED...THE UPPER LOW CONTINUES TO SLOW AND LOW POPS REMAIN IN PLACE OVER ERN/SRN MN AND WRN WI INTO SUNDAY NIGHT. CLEARING WILL GRADUALLY TAKE PLACE AND IT IS POSSIBLE TO GET AREAS OF FOG BY MONDAY MORNING DEPENDING ON TIMING OF CLEARING AND STRENGTH OF WIND. ANOTHER LONG STRETCH OF LATE SUMMER WEATHER WILL TAKE HOLD NEXT WEEK...PARTICULARLY TUESDAY ONWARD AS A DIGGING WEST COAST TROUGH LEADS TO A LARGE RIDGE BUILDING EASTWARD ACROSS THE PLAINS. STRONG RETURN FLOW AND GUSTY SOUTH WINDS TUESDAY WILL EASE MID/LATE WEEK AS A BAGGIER PRESSURE PATTERN DEVELOPS UNDER THE RIDGE. 925 MB TEMPS REACH THE MID/UPPER TEENS CELSIUS FOR MUCH OF NEXT WEEK...BRINGING HIGHS FIRMLY INTO THE 70S. GUIDANCE IS IN STRONG AGREEMENT FOR MID 70S...INCLUDING THE CLIMATOLOGICALLY FAVORING MOS PRODUCT AT EXTENDED RANGES. HIGHS AND LOWS WILL BE ABOUT 15 DEGREES ABOVE AVERAGE WITH NEARLY UNRESTRICTED SUNSHINE EACH DAY THROUGH THURSDAY. ANOTHER POTENT STORM SYSTEM WILL DEVELOP TO THE LEE OF THE ROCKIES THURSDAY NIGHT AND TRACK NORTHWARD INTO THE DAKOTAS FRIDAY NIGHT. THIS SHOULD KEEP THE MAJORITY OF THE AREA DRY THROUGH FRIDAY BEFORE THE COLD FRONT SWINGS THROUGH FRIDAY NIGHT. OVERALL...THE GFS AND ECMWF REMAIN IN RATHER GOOD AGREEMENT SO FORECAST CONFIDENCE IS HIGH THROUGHOUT THE LONG TERM PERIOD. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 650 PM CDT SAT OCT 5 2013 LOW CONFIDENCE FOR THE FORECAST OVERNIGHT AS AN OCCLUDED FRONT ARCS FROM KFSD THROUGH KSTC TO KEAU. DRIER LOW LEVEL AIR HAS PUSHED IN FROM THE SOUTH BEHIND THIS BOUNDARY SCOURING OUT THE LESS THAN MVFR CEILINGS AT KAXN...KSTC...KRNH AND KEAU LATE THIS AFTERNOON. HOWEVER... PLENTY OF FORCING UPSTAIRS HAS LEAD TO THE FORMATION OF A LARGE AREA OF LIGHT RAIN SHOWERS ACROSS CENTRAL AND EASTERN MN AND WEST CENTRAL WI. THE RAIN IS BASICALLY FALLING FROM CEILINGS AOB 070. THE CONCERN OVERNIGHT IS THAT A LOW PRESSURE SYSTEM IS EASTERN SD WILL BE DRIFTING SE. THIS WILL CAUSE THE FRONTAL BOUNDARY TO SAG SOUTH. IT WOULD SEEM THAT KAXN AND KSTC WOULD BE MOST VULNERABLE TO MVFR OR LOWER CEILINGS RETURNING. THE PIVOT ON THIS BOUNDARY IS RIGHT ACROSS THE NORTH METRO LATE TONIGHT... SO EVEN KMSP AND KRNH ARE NOT HOME FREE. KEAU MAY BE BEST OVERALL WITH VFR... BUT THE RAIN THIS EVENING COMBINED WITH THE HIGH CEILINGS MAY ALLOW FOG FORMATION AND LIFR CEILINGS BY DAYBREAK. THE FORECAST CONFIDENCE FOR MVFR CEILINGS IS LITTLE HIGHER ON SUNDAY AS THE AFOREMENTIONED BOUNDARY MOVES BACK SE ACROSS THE FORECAST AREA. THIS WILL BRING HIGH CHANCES FOR MVFR CEILINGS ALONG WITH SOME LIGHT RAIN. KMSP...NOT TOO MANY CONCERNS THIS EVENING FOR THE AIRFIELD WITH CEILINGS AOB 070. THE MAIN PROBLEM MAY BE THAT THE WIND MAY BE MORE NORTH THAN WEST DUE TO A LOW PRESSURE SYSTEM FORMING OVER WESTERN WISCONSIN. SOME LIGHT RAIN/SPRINKLES WILL CONTINUE FOR ANOTHER HOUR OR TWO THEN END. ATTENTION THEN TURNS TO THE POSSIBILITY OF IFR CEILINGS RETURNING FROM THE NORTH AROUND 08Z. EVEN IF THE AIRFIELD CAN STAY OUT OF THE LOW CEILINGS DURING THE LATE NIGHT HOURS...LOW MVFR CEILINGS ARE EXPECTED TO MOVE BACK IN SUNDAY MORNING. /OUTLOOK FOR KMSP/ MON...VFR...MVFR POSSIBLE EARLY. WINDS NW 5-10 KT. TUE...VFR. WINDS S 15G25 KT. WED...VFR. WINDS SSE 10-15 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SYNOPSIS...MPG SHORT TERM...MPG LONG TERM...BORGHOFF AVIATION...RAH
AREA FORECAST DISCUSSION
NWS DULUTH MN
647 PM CDT SAT OCT 5 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 319 PM CDT SAT OCT 5 2013 STACKED LOW PRESSURE OVER SOUTHEAST SOUTH DAKOTA WILL MOVE EAST/SOUTHEAST TONIGHT...ALTHOUGH THE SURFACE LOW IS FORECAST TO MOVE TOWARD UPPER MICHIGAN TONIGHT. AS THE SURFACE LOW NEARS THE NORTHLAND LATER TONIGHT...WINDS SHOULD GRADUALLY SUBSIDE. WE CONTINUE TO GET GUSTS OF 35 TO 45 MPH AT THE HEAD OF LAKE SUPERIOR...AND WE`LL EXTEND THE WIND ADVISORY FOR DOUGLAS...SOUTHERN SAINT LOUIS...CARLTON...AND SOUTHERN LAKE COUNTIES UNTIL 10 PM. THE STRONGEST WINDS WILL REMAIN WILL BE CLOSE TO LAKE SUPERIOR. RAIN WAS DEVELOPING ACROSS PORTIONS OF CENTRAL/SOUTHEAST MINNESOTA SIMILAR TO WHAT THE MODELS INCLUDING THE HRRR WERE DEPICTING. WE SHOULD CONTINUE TO SEE RAIN DEVELOP AND MOVE NORTH THROUGH THE NORTHLAND THIS EVENING/OVERNIGHT...BECOMING WIDESPREAD. WE`VE SEEN A FEW LIGHTNING STRIKES CLOSE TO THE AREA...SO ADDED A SLIGHT CHANCE FOR A STORM TO ALL AREAS LATE THIS AFTERNOON/EARLY EVENING...THEN TO EASTERN AREAS THROUGH LATE EVENING. SOME FOG WILL ALSO BE POSSIBLE...ESPECIALLY AROUND THE LAKE AND AS THE GRADIENT RELAXES. THERE WILL BE A CONTINUED CHANCE FOR SHOWERS ON SUNDAY...ALTHOUGH COVERAGE WILL BE LESS THAN WHAT HAS OCCURRED TODAY AND WHAT IS EXPECTED TONIGHT. THERE SHOULD STILL BE PLENTY OF CLOUDS AROUND THOUGH...AND THE MODELS CONTINUE TO SHOW PLENTY OF LOW LEVEL MOISTURE REMAINING. THE EXCEPTION WILL BE PORTIONS OF OUR SOUTHEAST ZONES EARLY...AND OUR FAR NORTHWEST ZONES LATE. HIGHS SUNDAY WILL RANGE FROM 55 TO 60 OVER OUR WESTERN/SOUTHEAST ZONES...WITH AREAS BETWEEN AROUND 50. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 319 PM CDT SAT OCT 5 2013 TAIL END OF A DEPARTING LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL ALLOW A FEW LIGHT RAIN SHOWERS TO LINGER ACROSS THE ERN HALF OF THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY MORNING. RAINFALL AMTS WILL BE LOW. HIGH PRESSURE WILL BUILD IN ACROSS THE UPPER MIDWEST MONDAY AND TUESDAY WITH QUIET WEATHER CONDITIONS AND WARMER TEMPERATURES. SKIES WILL REMAIN MOSTLY SUNNY EARLY IN THE WEEK BEFORE A WEAK SFC FRONT SLIDES ACROSS THE NRN PLAINS AND USHERS IN ADDITIONAL CLOUD COVER WED AND THURSDAY...MAINLY OVER THE NRN COUNTIES. THE UPPER RIDGE OVER THE ERN US WILL AMPLIFY LATE IN THE WEEK AS A TROUGH IN THE WEST DEEPENS THROUGH THE ROCKIES. THIS UPPER LOW WILL EVENTUALLY MOVE INTO THE MIDWEST BY THE WEEKEND AND BRING ADDITIONAL CHANCES FOR PRECIPITATION. TEMPERATURES WILL REMAIN ABOVE AVERAGE THIS WEEK WITH VERY MILD AFTERNOON HIGHS IN THE 60S AND LOWER 70S. OVERNIGHT LOWS EARLY IN THE WEEK WILL BE SLIGHTLY CHILLY INTO THE 30S AND LOWER 40S...BUT RISE INTO THE UPPER 40S AND LOWER 50S BY THE LATTER HALF OF THE WEEK. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 646 PM CDT SAT OCT 5 2013 YET ANOTHER BAND OF RAIN POISED TO MOVE ACROSS THE AREA THIS EVENING AND OVERNIGHT HOURS. WIDESPREAD IFR TO LIFR TO PERSIST AS THIS BAND MOVES THROUGH...WITH IFR TO MVFR VSBYS FOR THE NEXT SEVERAL HOURS. EVEN AFTER THE RAIN CLEARS THE TERMINALS LATE TONIGHT THE LOW CIGS AND VSBYS TO PERSIST WITH -DZ AND SCATTERED SHOWERS. DAYTIME SHOULD SEE SOME SMALL IMPROVEMENT TO IFR INSTEAD OF LIFR. SOME REAL IMPROVEMENT IN CIGS TO BE SEEN FOR WESTERN TERMINALS LATE AFTERNOON SUNDAY AS NORTHWEST FLOW BRINGS IN DRIER AIR. && .PRELIMINARY POINT TEMPS/POPS... DLH 47 51 40 62 / 90 60 20 10 INL 39 55 37 62 / 60 40 0 0 BRD 46 51 39 65 / 80 60 10 0 HYR 46 56 40 61 / 80 50 30 10 ASX 49 54 43 62 / 80 60 40 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR MNZ020-037. WI...WIND ADVISORY UNTIL 10 PM CDT THIS EVENING FOR WIZ001. LS...GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR LSZ141>147. SMALL CRAFT ADVISORY UNTIL 10 AM CDT SUNDAY FOR LSZ121-140-148. && $$ SHORT TERM...MELDE LONG TERM...BJT AVIATION...LE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
347 PM CDT FRI OCT 4 2013 .SYNOPSIS... ISSUED AT 347 PM CDT FRI OCT 4 2013 IMPRESSIVE FALL SYSTEM TAKING CENTER STAGE ACROSS THE CENTRAL CONUS TODAY. THE UPPER LOW IS NEAR THE NEB/CO/WY BORDER WITH AN IMPRESSIVE PV/UPPER JET INDUCED DRY SLOT WORKING ACROSS NEB. ON THE NOSE OF THE PV BOOT WE HAVE SEEN AN IMPRESSIVE BURST OF LIGHTNING NEAR THE BADLANDS. AS THE JET/DRY SLOT CONTINUES TO PUSH EAST ACROSS NEB...IT WILL BECOME AN INITIATION SOURCE FOR SEVERE CONVECTION OVER ERN NEB BY 22Z. AT THE SFC...A 1001 MB LOW WAS CENTERED OVER CENTRAL NEB WITH A COLD FRONT BEGINNING TO SURGE SE ACROSS KS AND THE OK/TX PANHANDLES. PERSISTENT CLOUD ACROSS MN/IA HAS PUT THE SKIDS ON THE NORTHWARD PROGRESSION OF THE WARM FRONT...BUT CLEARING RECENTLY OVER NRN IA HAS ALLOWED FOR THE WARM FRONT TO BECOME BETTER DEFINED. AT 3 PM THIS BOUNDARY WAS LOCATED JUST NORTH OF THE I-80 CORRIDOR... EXTENDING EAST TOWARD MILWAUKEE. PERSISTENT THUNDERSTORM DEVELOPMENT ACROSS IOWA NORTH OF THE WARM FRONT HAS HELPED REINFORCE IT TO THE SOUTH...AND ALSO AIDED IN THE MPX CWA REMAINING DRY. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 347 PM CDT FRI OCT 4 2013 BIGGEST CHANGE SEEN WITH THE FORECAST AS COMPARED TO LAST NIGHT IS EVERYTHING IS A BIT SLOWER...SO DELAYING THE ONSET OF CATEGORICAL POPS WAS THE BIGGEST CHANGE MADE TO THE FORECAST DURING THE DAY. THE HRRR HAS BEEN FAIRLY STABLE WITH ITS DEPICTION OF THINGS TODAY AND HAS SUPPORT FROM THE 04.12 HIRES-ARW...SO USED THESE TWO PIECES OF GUIDANCE TO GUIDE THE POP FORECAST THIS PERIOD. HAVE DELAYED BRINGING ANY LIKELY OR GREATER POPS INTO THE MPX AREA UNTIL AFTER 00Z. THIS COINCIDES WITH A SIGNIFICANT INCREASE IN H85 MOISTURE TRANSPORT IN RESPONSE TO A LLJ INCREASING TO OVER 30 KTS FROM IA BACK NW INTO ERN SODAK. MOISTURE CONVERGENCE AT THE NOSE OF THE LLJ WILL LEAD TO A RAPID EXPANSION OF SHRA/TSRA ACTIVITY FROM SE MN INTO WC MN BETWEEN 00Z AND 03Z AND LIFT NORTHEAST ACROSS THE AREA TONIGHT. AFTER 03Z...AN OCCLUDED FRONT WILL START MOVING INTO SRN MN...WHICH WILL ALREADY START DIMINISHING PRECIP COVERAGE ACROSS THE SOUTH BY 6Z. FOR THE SEVERE THREAT...THE SLOWER TIMING HAS CERTAINLY DIMINISHED THE CHANCES THE MPX AREA WILL SEE SEVERE WEATHER...WITH THE MAIN THREAT CORRIDOR LOOKING TO EXTEND FROM THE NEB/IA BORDER OVER TO ABOUT I-35 IN CENTRAL IOWA. THE MAIN THREAT FOR THE MPX AREA LOOKS TO BE DOWN ALONG THE I-90 CORRIDOR WHERE SOME ELEVATED LARGE HAIL STORMS COULD BE SEEN. FOR THE DAY SATURDAY...HOW THE DRY SLOT EVOLVES WILL HELP DETERMINE WHERE WE SEE A REPEAT OF THE LAST TWO DAYS AND WHERE WE COULD SEE A FAIR AMOUNT OF SUN. CURRENTLY...HAVE SKIES BEGINNING TO CLEAR AFTER 9Z IN SW MN...THEN SLOWLY TRACK THAT ENE DURING THE DAY. BY THE AFTERNOON...BOTH THE GFS AND NAM ARE INDICATING THAT MUCH OF THE TWIN CITIES COULD SEE MOSTLY SUNNY SKIES. ONLY CHANGES REALLY MADE TO THE FORECAST FOR TOMORROW WAS TO DECREASE CLOUD COVER AMOUNT ACROSS SRN MN AND DECREASE POPS OUTSIDE OF THE NRN AND ERN PERIPHERY OF THE MPX CWA...AS MOST GUIDANCE SHOW WRAP AROUND PRECIP ON THE WEST SIDE OF THE SYSTEM WAITING UNTIL 00Z TO MOVE BACK INTO WRN MN. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 347 PM CDT FRI OCT 4 2013 BY 00Z SUNDAY...THE SURFACE LOW WILL BE NEARLY STATIONARY AROUND SIOUX FALLS SD. THE DRY SLOT WILL STILL BE FIRMLY IN PLACE OVER MUCH OF SRN MN/WRN WI...WITH AN ARC OF RAIN ASSOCIATED WITH DECENT FRONTOGENESIS EXTENDING FROM CENTRAL/ERN WI THROUGH CENTRAL/NRN MN INTO THE EASTERN DAKOTAS. THE LOW WILL FILL AND EVENTUALLY WILL BE SHOVED EASTWARD IN RESPONSE TO THE BUILDING RIDGE OVER THE ROCKIES. THUS...THIS ARC OF RAIN WILL SLIDE EAST LATE SATURDAY NIGHT THROUGH SUNDAY...ALTHOUGH IN A DIMINISHING PHASE AS IT DOES SO. NONETHELESS...IT WILL BE CLOUDY AND RAINY/DRIZZLY UNDER THIS BAND FOR MUCH OF THE DAY SUNDAY UNTIL MUCH DRIER AIR CAN FINALLY PUSH IN FROM THE NORTHWEST SUNDAY EVENING. RIDGING WILL BUILD OVER THE MIDWEST THROUGH THE REST OF THE LONG TERM PERIOD AS A DEEP TROUGH DIGS DOWN THE WEST COAST. HIGH TEMPERATURES WILL MODERATE QUICKLY BACK INTO THE 70S BY MIDWEEK/LATE WEEK WHICH WILL BE 10 TO 15 DEGREES ABOVE AVERAGE. ANOTHER SIGNIFICANT STORM SYSTEM WILL DEVELOP TO THE LEE OF THE ROCKIES THURSDAY NIGHT AND TRACK MORE OR LESS NORTHWARD INTO THE DAKOTAS FRIDAY NIGHT. THIS SHOULD KEEP THE MAJORITY OF THE AREA DRY THROUGH THE FORECAST PERIOD...EXCEPT FOR PERHAPS WRN MN FRIDAY AFTERNOON. GFS AND ECMWF ARE IN RATHER GOOD AGREEMENT AT THIS TIME RANGE SO FORECAST CONFIDENCE IS HIGH FOR THE LONG TERM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 113 PM CDT FRI OCT 4 2013 TOUGH CIG FORECAST FOR THIS AFTERNOON...AS MOISTURE OVERRUNNING THE WARM FRONT TO THE SOUTH HAS HAD LIFR CIGS OVER SRN MN ALL DAY...BUT THE DRY NE FLOW IN PLACE HAS BEEN SLOWLY BRINGING MVFR CIGS SOUTHWEST INTO THE MPX TERMINALS. ALL BUT RWF SHOULD SEE A PERIOD OF MVFR CIGS THIS AFTERNOON...BEFORE IFR/LIFR CONDITIONS SPREAD BACK NORTH AFTER 00Z AS THE WARM FRONT LIFTS NORTH ACROSS IOWA. TRENDED TIMING OF RETURN OF PRECIP ON THE HRRR AND COULD SEE PRECIP ONSET IN TAFS NEEDING TO BE PUSHED BACK ANOTHER HOUR OR TWO. A PRONOUNCED DRY SLOT WILL BE MOVING IN WITH THE WARM FRONT LATE TONIGHT...WITH VFR AND MAINLY CLEAR SKIES OVER SRN MN SAT MORNING...WITH THE MAIN QUESTION BEING HOW FAR NORTH DOES THE CLEARING MAKE IT...ALONG WITH HOW QUICKLY DOES IT PUSH NORTHEAST. KMSP...MOST AIRPORTS IN THE METRO HAVE GONE MVFR...SO CONFIDENT IN CIGS RISING ABOVE 010...BUT WILL REMAIN BELOW 017. MAY SEE OCCASIONAL SHOWERS THROUGH THE AFTERNOON...BUT ALL GUIDANCE IN FAIRLY GOOD AGREEMENT WITH AN AREA OF SHRA AND A FEW TSRA MOVING ACROSS THE FIELD BETWEEN 2Z AND 8Z. AFTER THIS MAIN ROUND MOVES THROUGH...WILL LIKELY SEE OCCASIONAL BOUTS OF SHRA INTO SAT MORNING BEFORE THE DRY SLOT MOVES IN A ENDS ANY PRECIP. /OUTLOOK FOR KMSP/ SUN...MVFR OR LOWER. PERIODS OF -SHRA/-DZ. WINDS NW 10-15 KTS. MON...VFR. WINDS W 5-10 KT. TUE...VFR. WINDS S 5-10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ SYNOPSIS...MPG SHORT TERM...MPG LONG TERM...BORGHOFF AVIATION...MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
333 PM CDT FRI OCT 4 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY AFTERNOON) ISSUED AT 331 PM CDT FRI OCT 4 2013 MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE SHOWERS EXPECTED TO DEVELOP LATE THIS AFTERNOON...SPREAD SLOWLY NWD THROUGH THE NORTHLAND TONIGHT...WITH HEAVY RAIN POSSIBLE...AND LINGER THROUGH MUCH OF THE DAY TOMORROW. STRONG NORTHEAST WINDS OFF LAKE SUPERIOR ARE ALSO OF CONCERN IN THE SHORT TERM...AND A WIND ADVISORY REMAINS IN EFFECT UNTIL 4 PM SATURDAY FOR LAKESHORE AREAS AROUND THE HEAD OF THE LAKE. DEEP CUT-OFF UPPER LOW CONTINUES TO BARREL EWD ACROSS THE SRN ROCKIES INTO THE PLAINS THIS AFTERNOON...AS A SFC LOW STRENGTHENS OVER CENTRAL KS AND A WARM FRONT EXTENDS EWD THROUGH IA INTO SRN WI. LATEST SATELLITE IMAGERY SHOWS A WEDGE OF DRY AIR ALOFT PUSH SW TO NE FROM CENTRAL KS INTO SRN MN...WHICH HAS ALLOWED MUCH OF THE NORTHLAND TO REMAIN DRY THROUGH THE DAY. HOWEVER...THERE IS A WEAK BAND OF MID-LEVEL F-GEN ACROSS NRN/CENTRAL WI/MN THAT IS TRYING TO TRIGGER A FEW SHOWERS FROM BRAINERD MN TO LADYSMITH WI...AS EVIDENT ON LATEST RADAR SCAN. CURRENT THINKING IS THAT THIS LAYER OF F-GEN...FROM ROUGHLY 925 TO 700MB WILL BECOME ENHANCED AT 850MB AS THE UPPER LOW TO THE SW CONTINUES TO WRAP UP AND DRAW UP THE WARM/MOIST MID-LEVEL AIR FROM THE SOUTH. THE INTERACTION OF THE WARM AIR WITH THE COLD AIR ON THE BACK SIDE OF THE SYSTEM WILL ACT TO STRENGTHEN THE BAROCLINIC ZONE AND PROVIDE ENOUGH LIFT TO PRODUCE RAIN SHOWERS ACROSS MUCH OF THE REGION AND EVEN A FEW ISOLATED STORMS TO THE SOUTH TONIGHT. THE FORCING FROM THE UPPER LOW AND AVAILABLE MOISTURE...PWATS AROUND 1 INCH...SHOULD BE ENOUGH TO PRODUCE WIDESPREAD RAIN SHOWERS WITH LOCALLY HEAVY RAIN POSSIBLE LATE TONIGHT. MOST OF THE REGION COULD SEE AT LEAST A HALF INCH THROUGH SATURDAY AFTERNOON...WITH NUMEROUS LOCATIONS POSSIBLY SEEING UPWARDS OF AN INCH OR MORE. ADDITIONAL RAIN IS EXPECTED SAT NIGHT AND SUNDAY...SO STORM TOTAL RAINFALL AMTS WILL LIKELY REACH OR EXCEED 2 INCHES IN SOME LOCATIONS. THE HIGHER AMTS ARE EXPECTED ACROSS THE SRN COUNTIES. VERY STRONG NE WINDS AROUND THE HEAD OF LAKE SUPERIOR...INCLUDING THE TWIN PORTS...WILL BE THE OTHER IMPACT FROM THIS STORM. AS THE SFC LOW STRENGTHENS AND MOVES EWD ACROSS SRN MN AND CENTRAL WI TONIGHT AND TOMORROW...STRONG PRESSURE FALLS WILL OCCUR AHEAD OF THE LOW AND COMBINE WITH A SFC HIGH OVER ONTARIO...AND SMALL-SCALE FUNNELING THROUGH THE HEAD OF WRN LAKE SUPERIOR TO PRODUCE SUSTAINED WINDS AROUND 20 TO 30 MPH AND GUSTS 35 TO 45 MPH FROM THIS EVENING THROUGH SATURDAY AFTERNOON. THE WIND ADVISORY FOR THE LAKE SHORE FROM SILVER BAY TO DULUTH/SUPERIOR TO BAYFIELD IS IN EFFECT UNTIL 4 PM SATURDAY. THE REST OF THE NORTHLAND WILL SEE BREEZY CONDITIONS AS WELL WITH GUSTS TO 25 MPH. TEMPERATURES WILL REMAIN STEADY TONIGHT AS CLOUD COVER PERSISTS. LOWS TONIGHT WILL ONLY FALL INTO THE 40S TO THE NORTH AND LOWER 50S SOUTH. HIGHS ON SATURDAY WILL NOT RISE TOO FAR FROM THE MORNING LOWS. MID TO UPPER 40S ARE EXPECTED FOR MOST OF THE REGION...WITH MID TO UPPER 50S POSSIBLE OVER PARTS OF NW WI. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 331 PM CDT FRI OCT 4 2013 THE REGION WILL CONTINUE TO BE UNDER THE INFLUENCE OF THE STRONG LOW PRESSURE SYSTEM EARLY IN THE PERIOD. A BROAD AREA OF LOW AT THE SURFACE WILL BE OVER SOUTHERN MINNESOTA/NORTHERN IOWA AT 00Z SUNDAY AND IS FORECAST TO MOVE SLOWLY EAST/NORTHEAST SATURDAY NIGHT INTO SUNDAY. THERE SHOULD BE A FAIRLY WIDESPREAD AREA OF RAIN OVER MUCH OF OUR CWA SATURDAY NIGHT...WIT THE FAR NORTHWEST SEEING LOWEST CHANCES. STRONG WINDS WILL CONTINUE OFF OF LAKE SUPERIOR...BUT SHOULD BE A BIT LOWER THAN WHAT WE`LL EXPERIENCE TONIGHT INTO SATURDAY. A DEFORMATION BAND OF RAIN/DRIZZLE WILL CONTINUE INTO SUNDAY AND THAT WILL MOVE EAST SUNDAY NIGHT AND DIMINISH AS THE LOW MOVES FURTHER TO THE EAST. WE HAVE LOWERING POPS AS SUNDAY AFTERNOON AND SUNDAY NIGHT...BUT SEVERAL OF THE MODELS...ESPECIALLY THE 12Z ECMWF...SHOW A SLOWER END TO THE DEFORMATION BAND OF LIGHT RAIN/DRIZZLE. WE HELD ONTO CHANCES FOR RAIN A BIT LONGER...AND LATER SHIFTS MAY NEED TO DO SO MORE. WEAK HIGH PRESSURE BUILDS IN MONDAY AND WE KEPT THE FORECAST DRY. THE ECMWF STILL HANGS ONTO SOME LIGHT PRECIP OVER NORTHWEST WISCONSIN...AND A SMALL POP MAY HAVE TO BE ADDED IF THIS TREND CONTINUES. UPPER RIDGING SLOWLY BUILDS IN BEHIND THE DEPARTING DEEP SURFACE LOW TUESDAY WITH THE FLOW ALOFT BECOMING SOUTHERLY AS THE RIDGE PASSES BY THURSDAY/FRIDAY. A DRY PERIOD IS EXPECTED MONDAY THROUGH FRIDAY FOR MOST AREAS. TEMPERATURES WILL START OUT COOL SUNDAY WITH HIGHS ONLY FROM THE UPPER FORTIES TO MID FIFTIES BUT WILL WARM AS THE UPPER RIDGE APPROACHES. HIGHS BY WEDNESDAY ARE EXPECTED IN THE MIDDLE SIXTIES FOR MOST AREAS...WITH MID-UPPER SIXTIES THURSDAY/FRIDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1244 PM CDT FRI OCT 4 2013 A STRONG LOW PRESSURE SYSTEM WILL IMPACT THE REGION THROUGH THE PERIOD WITH CONDITIONS GRADUALLY BECOMING WIDESPREAD MVFR/IFR. AS OF EARLY THIS AFTERNOON...THERE WAS A MIX OF MVFR CEILINGS WITH VFR. AS THE PERIOD PROGRESSES...CEILINGS WILL LOWER AND RAIN WILL DEVELOP FROM SOUTH TO NORTH. THE BEST CHANCE FOR RAIN WILL OCCUR AFTER 03Z THROUGH 15Z SATURDAY. MVFR/IFR VSBYS/CEILINGS WILL OCCUR AS THE RAIN BECOMES MORE WIDESPREAD. THE RAP SUGGESTS IT WILL TAKE LONGER FOR THE MVFR CEILINGS TO DEVELOP TODAY/THIS EVENING OVER NORTHERN AREAS DUE TO A DRIER EASTERLY FLOW THERE. WE LEFT THE MENTION OF THUNDERSTORMS OUT OF THE TAFS FOR NOW...BUT THERE COULD BE SOME THAT DEVELOP...ESPECIALLY ACROSS KHYR/KBRD/KDLH. STRONG NORTHEAST/EAST WINDS OFF OF LAKE SUPERIOR CAN BE EXPECTED THROUGH THE TAF PERIOD. THE STRONGEST WINDS WILL OCCUR TONIGHT INTO SATURDAY. && .PRELIMINARY POINT TEMPS/POPS... DLH 48 49 43 50 / 90 80 90 60 INL 41 47 36 54 / 60 70 50 20 BRD 49 50 39 52 / 90 80 80 60 HYR 50 54 45 51 / 90 80 70 50 ASX 49 52 46 53 / 80 80 80 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...WIND ADVISORY UNTIL 4 PM CDT SATURDAY FOR MNZ020-037. WI...WIND ADVISORY UNTIL 4 PM CDT SATURDAY FOR WIZ001-002. LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ143>147. GALE WARNING UNTIL 4 PM CDT SATURDAY FOR LSZ143>147. SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-140>142- 148. && $$ SHORT TERM...BJT LONG TERM...MELDE AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
113 PM CDT FRI OCT 4 2013 .UPDATE... ISSUED AT 113 PM CDT FRI OCT 4 2013 SIGNIFICANTLY CUT BACK ON POPS THIS AFTERNOON BASED ON CURRENT RADAR TRENDS ALONG WITH THE HRRR...THEN DELAYED ARRIVAL OF THINGS TONIGHT. HAVE SEEN DRY AIR WORK IN ON WATER VAPOR IMAGERY THIS AFTERNOON...WHICH HAS CUT BACK ON THE PRECIP GENERATION. WILL LIKELY BE AFTER 00Z WHEN THE LLJ BEGINS TO RE-INTENSIFY AND MOVE NORTH ACROSS IOWA THAT THE MPX AREA SEES ANY SIGNIFICANT RAIN. SYSTEM IN GENERAL IS TRENDING SLOWER THAN ORIGINALLY THOUGHT OVERNIGHT...WITH EVEN THE SPC PULLING THE MODERATE RISK A BIT SW WITH THEIR NOON UPDATE...KEEPING IT OUT OF THE MPX AREA. AT 1 PM...THE WARM FRONT WAS STILL SOUTH OF I-80 IN IOWA AND ALL INDICATIONS SHOW IT NOT ARRIVING INTO SRN MN UNTIL WELL AFTER 00Z. TRIED FOLLOWING TIMING OF THE HRRR AND 04.12 HIRES-ARW FOR BRINGING IN NEXT ROUND OF THUNDERSTORMS TONIGHT...WHICH DO NOT LOOK TO BEGIN IMPACTING SRN MN UNTIL 00Z AT THE EARLIEST BEFORE RAPIDLY SPREADING NORTHEAST WITH THE LLJ. GIVEN THE SHEAR...WILL CERTAINLY STILL BE A SEVERE THREAT FOR SOUTH CENTRAL MN FOR MAINLY LARGE HAIL AND WIND TONIGHT...BUT FINDING IT HARD PRESSED TO SEE MUCH OF SEVERE THREAT ONCE YOU START GOING NORTH OF A NEW ULM TO ROCHESTER LINE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 432 AM CDT FRI OCT 4 2013 THE THREAT FOR SEVERE WEATHER EXISTS TODAY ACROSS PORTIONS OF SOUTHERN MN AND WESTERN WI. NOTE: THERE WAS LITTLE CHANGE FROM YESTERDAY`S DAY 2 MODERATE RISK TO THIS MORNING`S DAY 1 MODERATE RISK AREA FROM THE STORM PREDICTION CENTER. THIS MORNING`S OUTLOOK STILL HAS THE MODERATE RISK CLIPPING FAR SOUTHERN PORTIONS OF THE FORECAST AREA. THE FIRST ORDER OF BUSINESS WAS TO DROP TEMPERATURES TODAY AND KEEP EVERYTHING IN THE 50S AND LOW 60S...EXCEPT FOR LOCATIONS NEAR THE MN/IA BORDER WHERE THE WARM FRONT WILL LIKELY ARRIVE LATE THIS EVENING. IT WILL BE ONE GLOOMY DAY NORTH OF THE FRONT. THE THEME ALONG WITH THIS SYSTEM HAS BEEN A SLOWING TREND WITH TIME...AND THE AVAILABLE 00-06Z RUNS ARE EVEN A BIT SLOWER YET AND FARTHER TO THE SOUTHWEST WITH THE DEVELOPMENT OF THE SURFACE CYCLONE. IN FACT...THE 500 MB LOW IS STILL DIGGING SOUTH EARLY THIS MORNING AS EVIDENT BY THE WATER VAPOR LOOP AND LOCATION OF THE HEIGHT FALLS. NOW EVENTUALLY /BETWEEN 12-18Z/ THE TROUGH IS GOING TO BEGIN TO LIFT AND TAKE MORE OF AN E/NE TRACK. SEE THE DAY 1 SPC DISCUSSION: WWW.SPC.NOAA.GOV/PRODUCTS/OUTLOOK/DAY1OTLK.HTML FOR A SLIGHTLY MORE THOROUGH DISCUSSION OF THE LARGE-SCALE ENVIRONMENT AND OVERALL SEVERE WEATHER THREAT. NO BIG OBJECTIONS TO THE POSITION OF THE SPC RISK AREAS. ONE COULD MAKE AN ARGUMENT THAT THE SLIGHT RISK IS TOO FAR TO THE NORTH GIVEN THE SLOWER EVOLUTION AND ALSO DUE TO THE FACT THAT THUNDERSTORMS HAVE BEEN ONGOING ACROSS NE/IA FOR MOST OF THE NIGHT AND HAVE PUSHED THE BOUNDARY WELL SOUTH. THE WARM FRONT IS GOING TO HAVE TO COVER SOME SERIOUS GROUND TO GET BACK NEAR MN THIS EVENING. FURTHERMORE...WE SHOULD CONTINUE TO BE SHROUDED IN CLOUD COVER WITH A FEW BOUTS OF LIGHT RAIN OR DRIZZLE. THAT BEING SAID...THE WARM SECTOR DOES SURGE NORTH AND APPROACHES THE SOUTH TWIN CITIES METRO NEAR MIDNIGHT OFF THE NAM...THE GFS AND ECMWF ARE SLOWER. THERE WILL STILL BE ELEVATED INSTABILITY IN SOUTHERN MN...SO MARGINALLY SEVERE HAIL WOULD BE A THREAT LATE THIS EVENING EVEN IF THE WARM FRONT IS SLOW TO RETURN. THE BIG CYCLONICALLY LOPING HODOGRAPHS IN THE SOUTH ARE IMPRESSIVE BECAUSE MOST OF THE CURVATURE IS IN THE LOWEST 2-3 KM WITH THE BACKED FLOW...SO I CAN SEE THE TORNADO CONCERN IN IOWA WHERE THEY SHOULD RECOVER AND GENERATE SOME INSTABILITY BY THE LATE AFTERNOON. OBVIOUSLY...THUNDERSTORM INITIATION OR COVERAGE WILL NOT BE A CONCERN WITH THIS SYSTEM. THE INCREASING UPPER JET /100+ KTS/ AND GOOD THICKNESS DIFFLUENCE IS VACATING A LOT OF AIR ALOFT...JUST BEGGING SURFACE PARCELS TO GO FOR A RIDE. THE QUESTION IN MN WILL BE HOW FAST THE INSTABILITY IS ADVECTED INTO THE AREA. SPC`S SIGNIFICANT SEVERE AREA IS PREDICATED ON THE DEVELOPMENT OF SUPERCELLS /PREFERABLE DISCRETE/ IN IOWA LATE THIS AFTERNOON AND EARLY EVENING - THAT`S HOW SOUTHERN MN WOULD END UP WITH SIG SEVERE HAIL OR ANY TORNADOES AS WELL. IT HAPPENED IN EASTERN NEBRASKA LAST NIGHT ALONG THE COLD FRONT BEFORE STORMS DEVELOPED A COLD POOL. MORE LIKELY...THE CONVECTIVE MODE WILL BE EVOLVING UPSCALE INTO MORE OF A WIND/SMALLER HAIL EVENT WHEN IT REACHES THE FORECAST AREA. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 432 AM CDT FRI OCT 4 2013 POTENT WOUND-UP LOW PRES CENTER WILL BE LOCATED IN ERN SD BY DAYBREAK SAT MRNG WITH A LINE OF OR CLUSTERS OF TSTMS ONGOING IN FAR ERN PORTIONS OF THE WFO MPX CWFA. THE PRECIP WILL ACTUALLY COME TO A SHARP END SAT MRNG AS ALL MODELS ARE IN GOOD AGREEMENT OF A WELL-DEFINED AND DEEP DRY SLOT ON THE SRN AND ERN SIDES OF THE LOW PRES CENTER. THIS DRY SLOT WILL THEN PROCEED EWD THRU THE DAY...BUT AS THE UPR LOW BEGINS TO OVERTAKE THE SFC REFLECTION... THE DRY SLOT WILL GRADUALLY FILL UP WITH A RESURGENCE OF MOISTURE. THIS WILL ALLOW FOR THE FORMATION OF ADDITIONAL SHOWERS SAT NIGHT THRU MUCH OF SUN. NOT EXPECTING TSTMS ASIDE FROM FAR SE MN INTO SW WI...BUT THE COLD POOL ALOFT WITH THIS SYSTEM COULD ALLOW FOR SOME GRAUPEL /SMALL HAIL/ TO DEVELOP WITH SOME OF THE SHOWERS. THE PRECIP WILL OVERALL SHIFT OFF TO THE E SUN NIGHT INTO MON...BEING REPLACED BY DEEP RIDGING AND SFC HIGH PRES THAT WILL PREVENT SYSTEMS OF ANY CONSEQUENCE FROM IMPACTING THE AREA. FROM MON ON...A DRY FCST IS IN PLACE. AS FOR TEMPS...NOTICEABLE DIFFERENCES E-W ACRS THE AREA WILL BE PRESENT ON SAT AS THE LOW PRES CENTER MOVES ATOP THE REGION...WITH SFC FLOW NEARLY 180 DEGREES DIFFERENT ACRS THE REGION. BY SUN...WITH THE LOW PRES CENTER E OF THE AREA...MORE PRONOUNCED NLY FLOW WILL KICK IN NOTICEABLE CAA FOR THE AREA. THE COOLDOWN WILL NOT LAST LONG AS RIDGING ALOFT WILL MAKE FOR INCRG H5 HEIGHTS AND DEVELOPING SLY LLVL FLOW WHICH WILL BRING IN MUCH WARMER TEMPERATURES FOR MON THRU THU...INCLUDING HIGHS REACHING THE MID 70S IN SRN MN ON THU. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 113 PM CDT FRI OCT 4 2013 TOUGH CIG FORECAST FOR THIS AFTERNOON...AS MOISTURE OVERRUNNING THE WARM FRONT TO THE SOUTH HAS HAD LIFR CIGS OVER SRN MN ALL DAY...BUT THE DRY NE FLOW IN PLACE HAS BEEN SLOWLY BRINGING MVFR CIGS SOUTHWEST INTO THE MPX TERMINALS. ALL BUT RWF SHOULD SEE A PERIOD OF MVFR CIGS THIS AFTERNOON...BEFORE IFR/LIFR CONDITIONS SPREAD BACK NORTH AFTER 00Z AS THE WARM FRONT LIFTS NORTH ACROSS IOWA. TRENDED TIMING OF RETURN OF PRECIP ON THE HRRR AND COULD SEE PRECIP ONSET IN TAFS NEEDING TO BE PUSHED BACK ANOTHER HOUR OR TWO. A PRONOUNCED DRY SLOT WILL BE MOVING IN WITH THE WARM FRONT LATE TONIGHT...WITH VFR AND MAINLY CLEAR SKIES OVER SRN MN SAT MORNING...WITH THE MAIN QUESTION BEING HOW FAR NORTH DOES THE CLEARING MAKE IT...ALONG WITH HOW QUICKLY DOES IT PUSH NORTHEAST. KMSP...MOST AIRPORTS IN THE METRO HAVE GONE MVFR...SO CONFIDENT IN CIGS RISING ABOVE 010...BUT WILL REMAIN BELOW 017. MAY SEE OCCASIONAL SHOWERS THROUGH THE AFTERNOON...BUT ALL GUIDANCE IN FAIRLY GOOD AGREEMENT WITH AN AREA OF SHRA AND A FEW TSRA MOVING ACROSS THE FIELD BETWEEN 2Z AND 8Z. AFTER THIS MAIN ROUND MOVES THROUGH...WILL LIKELY SEE OCCASIONAL BOUTS OF SHRA INTO SAT MORNING BEFORE THE DRY SLOT MOVES IN A ENDS ANY PRECIP. /OUTLOOK FOR KMSP/ SUN...MVFR OR LOWER. PERIODS OF -SHRA/-DZ. WINDS NW 10-15 KTS. MON...VFR. WINDS W 5-10 KT. TUE...VFR. WINDS S 5-10 KT. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ UPDATE...MPG SHORT TERM...CLF LONG TERM...JPC AVIATION...MPG
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
332 PM CDT Fri Oct 4 2013 .SHORT TERM: (Through Late Tonight) Issued at 330 PM CDT Fri Oct 4 2013 Diurnal heating of the unseasonably warm and moist air mass has resulted in weak instability across the region this afternoon. However with little impetus, attempts for convective development thus far across far southeast Missouri and southern Illinois have been short-lived. The HRRR continues to indicate potential for spot storms through sunset within the southern CWA so will continue with some slight chance pops until then. Otherwise attention for tonight turns to the strong storm system currently across the Plains region. Anticipating that a squall line will evolve ahead of the attendant cold front from Nebraska into Oklahoma this evening and this will move eastward as the whole system progresses, with a swath of precipitation also developing overnight in the wake of the front in response to frontogenetical forcing and large scale ascent as a short-wave rotates through the base of the progressive upper trof. The main question then is just how far eastward all of this precipitation will get before daybreak Saturday. The consensus of the model guidance is that it may be after 12z before entering the CWA. At this time I didn`t deviate dramatically from the previous forecast with the leading edge just making it into the western CWA, but reduced pops further east. Areas to the east of the main line will still be under the threat of spotty warm advection activity overnight. Glass .LONG TERM: (Saturday through Next Friday) Issued at 300 PM CDT Fri Oct 4 2013 By Saturday morning, surface cold front to be just west of St. Louis metro area. As the occluded surface low, over southeastern SD, associated with it slowly lifts out to the northeast, front to slowly slide through rest of forecast area. Expect activity that initially forms tonight to diminish by mid morning. Then trying to determine when and where activity will refire as atmosphere becomes more unstable by early afternoon is hard to pin down. With front extending from Quincy to just west of St. Louis to near Monett by 18z Saturday, best chances of storms refiring and some severe weather will be over southeast MO and southern IL. This matches well with the day 2 outlook with this area in a slight risk. Another forecast issue will be temperatures on Saturday. Will see a non-diurnal trend as high temps will be reached early in the day then either remain steady or fall during the afternoon hours. Showers and isolated thunderstorms will taper off Saturday evening before coming to an end. However, could see some scattered showers on Sunday, especially during the afternoon hours as wrap around clouds on back side of system moves through with an upper level shortwave. So have added low chance pops over northeast MO/west central IL with silent slight chance pops further south for now as well as increase cloud cover through this period. Lows Saturday night will be in the low 40s to low 50s with highs only rising into the mid 50s to mid 60s on Sunday. Sunday night could be our coldest night depending on how fast the clouds clear out. For now will err on side of caution and keep more clouds over the region with lows in the low to mid 40s. If clouds completely clear out and winds remain light, could see even cooler temps. Beyond that, surface ridge moves off to the east with a slow warming trend through the week. Temperatures to warm back up into the mid to upper 70s by Thursday. Byrd && .AVIATION: (For the 18z TAFs through 18z Saturday Afternoon) Issued at 1209 PM CDT Fri Oct 4 2013 Diurnal cu continues to develop in response to heating of the unseasonably warm and moist air mass across the region. We should see scattered-broken cu with bases from 3000-4000 ft initially rising slowly through the afternoon. There could also be some isolated showers and thunderstorms, especially across the southeast third of Missouri and southern Illinois but coverage and uncertainty is too low to mention in the St. Louis area TAFS. The diurnal cu should dissipate by/around sunset with high clouds through the evening and then increasing low clouds overnight ahead of an approaching cold front. There will be a 2-4 hour window with shower and thunderstorms chances along/ahead of the front as it progresses across the area on Saturday. Given how far this is into the valid TAF period I have opted for -SHRA VCTS. In the wake of the front it appears we should see a period of rain with MVFR conditions previaling. Specifics for KSTL: Expecting see scattered-broken diurnal cu this afternoon. There could also be some isolated showers and thunderstorms but coverage and uncertainty is too low to mention in TAF. The diurnal cu should dissipate by/around sunset with high clouds through the evening and then increasing low clouds overnight ahead of an approaching cold front. There will be a roughly 3 hour window with shower and thunderstorms chances along/ahead of the front as it progresses across the area on Saturday morning from around 16-19z. Given how far this is into the valid TAF period I have opted for -SHRA VCTS. Fropa is expected around 19z, and in the wake of the front it appears we should see a period of rain with MVFR conditions previaling. Glass && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1239 PM CDT Fri Oct 4 2013 .UPDATE... Issued at 1128 AM CDT FRI OCT 4 2013 Forecast thoughts for today and tonight have not changed much. Still expect the cold front to sweep into eastern Kansas and far western Missouri as a large upper level trough transits east from the Rocky Mountains, bringing strong to potentially severe thunderstorms to portions of the forecast area this evening. Timing on storms continues to point at storms bubbling up and moving through extreme eastern Kansas this evening --7PM to 9PM--. However, ahead of the front storms are expected to continue bubbling up with isolated to scattered showers or thunderstorms possible west of St Joseph and Kansas City. Activity through the remainder of the morning and much of the afternoon is not expected to be severe, though small hail and locally heavy rain will be possible with the afternoon activity. && .SHORT TERM...(Today through Saturday) Issued at 414 AM CDT FRI OCT 4 2013 The next 48 hours will be a tale of two air masses, one more common during mid-summer and the other more like late Fall. Much better agreement between the models on timing of the cold front as well as the placement of the upper level trough lends to a more confident forecast and increase in PoPs with the frontal boundary. For today a strong upper trough over the Great Basin centered just east of SLC will lift northeast and into the Northern and Central Plains by Saturday. Increasing downstream pressure falls have already induced a surface low over northwest KS which will deepen and likewise track northeast as the increasing dynamics aloft overspread the Plains. A large warm sector exists east of the Central Rockies with an impressive southwesterly low level jet in excess of 50kts extending through OK, KS and western MO. A narrow band of scattered elevated convection has formed as the right rear quad of a 70kt wind max at 200mb encounters an axis of MLCAPES around 1000 J/kg aligned near the low level jet axis. Earlier versions of the HRRR and the 00Z NAM did a good job of forecasting this activity. Expect this convection to spread across northwest MO and northeast KS this morning before weakening towards the noon hour. The afternoon hours should be mainly dry except for late in the day over northwest MO. Temperatures will be impacted by the increasing mid level cloud cover this morning and the convection over northwest MO. However, should see clouds scatter out this afternoon and allow good mixing to reach highs well into the 80s. The weather will become quite active this evening as a convection rapidly forms along a cold front over KS and southeast NE. This boundary is attached to the low pressure center and will swing eastward through the CWA. Given a moderate to highly unstable airmass with over 2000 J/kg of MLCAPE plus the above noted h8 jet and steepening mid level lapse rates due to cold air aloft overspreading the region, the cap now in place will be lifted allowing for rapid development of convection along the frontal boundary. Expect this activity to form over eastern KS and southeast NE by late afternoon and enter the far northwest CWA around 00Z. Severe storms will be possible this evening mainly west of the I-35 corridor with large hail and damaging winds initially and as the squall line matures evolving into a high wind threat. With precipitable water values progged close to two standard deviations above normal any training cells will produce very heavy rainfall. This may be especially true after midnight as the NAM hints at post frontal elevated convection forming due to increasing frontogenesis within the 850-750mb layer. While the cold front is expected to clear the CWA by Saturday morning the post frontal stratiform rain with embedded thunder will likely linger through Saturday morning over the eastern half of the CWA. A major influx of cold air will be ushered into the CWA on gusty westerly winds. Even with clearing skies the cold air advection will overwhelm what little warming the sun will provide. As such temperatures will struggle to warm much past 60 over the western half of the CWA. Saturday night promises a need to turn on your furnace as deep cold air advection continues with h8 temperatures around 0C possible. Should see some lows fall into the upper 30s across northern MO. .LONG TERM...(Sunday through Thursday) Issued at 414 AM CDT FRI OCT 4 2013 Model differences in the beginning of the extended period will make for a tricky forecast on Sunday. The associated upper level trough, that will be responsible for driving a cold front through the area Friday night into Saturday morning, will develop a cut off low in the base of the trough. This upper low will be a slow mover and by Sunday is expected to be moving north of the CWA. However, models are different as to the placement of the low. The EC and GFS ensemble mean are the slowest and furthest south taking the upper low across Iowa on the day Sunday. The operational GFS and GEM are further north and more progressive with the upper low. The GEM and operational GFS would lead to a dry and slightly warmer solution whereas, the GFS ensemble and EC solution would be cooler with even a chance for some light precipitation across northern Missouri. for now, sided with the ALLBlend which is a compromise solution in keeping conditions dry with highs in the upper 50 and lower 60s. As surface high pressure builds in Sunday night temperatures will bottom out in the lower 40s. Beyond Sunday, the general trend amongst models is similar in keeping conditions dry with a warming trend. Monday will be a transitional day with northwest flow aloft behind the departing upper level system. A return to southwesterly flow and plentiful sunshine should allow highs to warm into the mid 60s to near 70. Tuesday, an upper level ridge will begin to build into the area in response to an upper level trough digging southward down the western CONUS. This upper level ridge is expected to dominate the area as well as much of the eastern half of the CONUS through Thursday. Highs will warm through the middle part of the week with highs in the mid to upper 70s by Thursday. && .AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon) Issued at 1238 PM CDT FRI OCT 4 2013 Focus for the terminals over the next 24 hours is squarely on the evening hours of today as a cold front, and associated thunderstorms, blow through. Breezy southerly winds ahead of the front today will keep much of the afternoon storm activity passing to the north of the terminals. However, starting around 23Z to 00Z the front will be nosing into northwest Missouri. Expectations are for activity to reach the terminals between 01Z to 03Z this evening with a couple hours of strong storms expected. These storms will likely bring widely variable winds this evening, along with the threat of hail. Strong storms should blow through before midnight, but low clouds --MVFR-- with showers will likely spread across the terminals through much of the early morning hours. Otherwise, winds behind the cold front will be rather strong and gusty Saturday, but the current onset time of these winds looks late enough in the period to warrant not including in the TAF at this time. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ UPDATE...Cutter SHORT TERM...MJ LONG TERM...73 AVIATION...Cutter
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1128 AM CDT Fri Oct 4 2013 .UPDATE... Issued at 1128 AM CDT FRI OCT 4 2013 Forecast thoughts for today and tonight have not changed much. Still expect the cold front to sweep into eastern Kansas and far western Missouri as a large upper level trough transits east from the Rocky Mountains, bringing strong to potentially severe thunderstorms to portions of the forecast area this evening. Timing on storms continues to point at storms bubbling up and moving through extreme eastern Kansas this evening --7PM to 9PM--. However, ahead of the front storms are expected to continue bubbling up with isolated to scattered showers or thunderstorms possible west of St Joseph and Kansas City. Activity through the remainder of the morning and much of the afternoon is not expected to be severe, though small hail and locally heavy rain will be possible with the afternoon activity. && .SHORT TERM...(Today through Saturday) Issued at 414 AM CDT FRI OCT 4 2013 The next 48 hours will be a tale of two air masses, one more common during mid-summer and the other more like late Fall. Much better agreement between the models on timing of the cold front as well as the placement of the upper level trough lends to a more confident forecast and increase in PoPs with the frontal boundary. For today a strong upper trough over the Great Basin centered just east of SLC will lift northeast and into the Northern and Central Plains by Saturday. Increasing downstream pressure falls have already induced a surface low over northwest KS which will deepen and likewise track northeast as the increasing dynamics aloft overspread the Plains. A large warm sector exists east of the Central Rockies with an impressive southwesterly low level jet in excess of 50kts extending through OK, KS and western MO. A narrow band of scattered elevated convection has formed as the right rear quad of a 70kt wind max at 200mb encounters an axis of MLCAPES around 1000 J/kg aligned near the low level jet axis. Earlier versions of the HRRR and the 00Z NAM did a good job of forecasting this activity. Expect this convection to spread across northwest MO and northeast KS this morning before weakening towards the noon hour. The afternoon hours should be mainly dry except for late in the day over northwest MO. Temperatures will be impacted by the increasing mid level cloud cover this morning and the convection over northwest MO. However, should see clouds scatter out this afternoon and allow good mixing to reach highs well into the 80s. The weather will become quite active this evening as a convection rapidly forms along a cold front over KS and southeast NE. This boundary is attached to the low pressure center and will swing eastward through the CWA. Given a moderate to highly unstable airmass with over 2000 J/kg of MLCAPE plus the above noted h8 jet and steepening mid level lapse rates due to cold air aloft overspreading the region, the cap now in place will be lifted allowing for rapid development of convection along the frontal boundary. Expect this activity to form over eastern KS and southeast NE by late afternoon and enter the far northwest CWA around 00Z. Severe storms will be possible this evening mainly west of the I-35 corridor with large hail and damaging winds initially and as the squall line matures evolving into a high wind threat. With precipitable water values progged close to two standard deviations above normal any training cells will produce very heavy rainfall. This may be especially true after midnight as the NAM hints at post frontal elevated convection forming due to increasing frontogenesis within the 850-750mb layer. While the cold front is expected to clear the CWA by Saturday morning the post frontal stratiform rain with embedded thunder will likely linger through Saturday morning over the eastern half of the CWA. A major influx of cold air will be ushered into the CWA on gusty westerly winds. Even with clearing skies the cold air advection will overwhelm what little warming the sun will provide. As such temperatures will struggle to warm much past 60 over the western half of the CWA. Saturday night promises a need to turn on your furnace as deep cold air advection continues with h8 temperatures around 0C possible. Should see some lows fall into the upper 30s across northern MO. .LONG TERM...(Sunday through Thursday) Issued at 414 AM CDT FRI OCT 4 2013 Model differences in the beginning of the extended period will make for a tricky forecast on Sunday. The associated upper level trough, that will be responsible for driving a cold front through the area Friday night into Saturday morning, will develop a cut off low in the base of the trough. This upper low will be a slow mover and by Sunday is expected to be moving north of the CWA. However, models are different as to the placement of the low. The EC and GFS ensemble mean are the slowest and furthest south taking the upper low across Iowa on the day Sunday. The operational GFS and GEM are further north and more progressive with the upper low. The GEM and operational GFS would lead to a dry and slightly warmer solution whereas, the GFS ensemble and EC solution would be cooler with even a chance for some light precipitation across northern Missouri. for now, sided with the ALLBlend which is a compromise solution in keeping conditions dry with highs in the upper 50 and lower 60s. As surface high pressure builds in Sunday night temperatures will bottom out in the lower 40s. Beyond Sunday, the general trend amongst models is similar in keeping conditions dry with a warming trend. Monday will be a transitional day with northwest flow aloft behind the departing upper level system. A return to southwesterly flow and plentiful sunshine should allow highs to warm into the mid 60s to near 70. Tuesday, an upper level ridge will begin to build into the area in response to an upper level trough digging southward down the western CONUS. This upper level ridge is expected to dominate the area as well as much of the eastern half of the CONUS through Thursday. Highs will warm through the middle part of the week with highs in the mid to upper 70s by Thursday. && .AVIATION...(For the 12Z TAFS through 12Z Saturday Morning) Issued at 651 AM CDT FRI OCT 4 2013 Band of scattered showers and storms will affect far northwest MO and northeast KS this morning, missing the Kansas City terminals and may pass just to the west of KSTJ. MVFR stratus has formed in the very humid airmass and latest BUFR soundings indicate these ceilings will linger into the late morning before lifting. Attention then turns to this evening when a band of strong/possibly severe storms forms along a cold front. Models are in good agreement with timing giving a boost to confidence. Expect showers and storms to pass through the terminals during the evening hours. VFR ceilings most likely except with the heavy showers which could lower ceilings to MVFR with IFR visibilities. Frontal passage likely with initial line of storms but convection will linger well past the passage of the front. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ UPDATE...Cutter SHORT TERM...MJ LONG TERM...73 AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
700 AM CDT Fri Oct 4 2013 .SHORT TERM...(Today through Saturday) Issued at 414 AM CDT FRI OCT 4 2013 The next 48 hours will be a tale of two air masses, one more common during mid-summer and the other more like late Fall. Much better agreement between the models on timing of the cold front as well as the placement of the upper level trough lends to a more confident forecast and increase in PoPs with the frontal boundary. For today a strong upper trough over the Great Basin centered just east of SLC will lift northeast and into the Northern and Central Plains by Saturday. Increasing downstream pressure falls have already induced a surface low over northwest KS which will deepen and likewise track northeast as the increasing dynamics aloft overspread the Plains. A large warm sector exists east of the Central Rockies with an impressive southwesterly low level jet in excess of 50kts extending through OK, KS and western MO. A narrow band of scattered elevated convection has formed as the right rear quad of a 70kt wind max at 200mb encounters an axis of MLCAPES around 1000 J/kg aligned near the low level jet axis. Earlier versions of the HRRR and the 00Z NAM did a good job of forecasting this activity. Expect this convection to spread across northwest MO and northeast KS this morning before weakening towards the noon hour. The afternoon hours should be mainly dry except for late in the day over northwest MO. Temperatures will be impacted by the increasing mid level cloud cover this morning and the convection over northwest MO. However, should see clouds scatter out this afternoon and allow good mixing to reach highs well into the 80s. The weather will become quite active this evening as a convection rapidly forms along a cold front over KS and southeast NE. This boundary is attached to the low pressure center and will swing eastward through the CWA. Given a moderate to highly unstable airmass with over 2000 J/kg of MLCAPE plus the above noted h8 jet and steepening mid level lapse rates due to cold air aloft overspreading the region, the cap now in place will be lifted allowing for rapid development of convection along the frontal boundary. Expect this activity to form over eastern KS and southeast NE by late afternoon and enter the far northwest CWA around 00Z. Severe storms will be possible this evening mainly west of the I-35 corridor with large hail and damaging winds initially and as the squall line matures evolving into a high wind threat. With precipitable water values progged close to two standard deviations above normal any training cells will produce very heavy rainfall. This may be especially true after midnight as the NAM hints at post frontal elevated convection forming due to increasing frontogenesis within the 850-750mb layer. While the cold front is expected to clear the CWA by Saturday morning the post frontal stratiform rain with embedded thunder will likely linger through Saturday morning over the eastern half of the CWA. A major influx of cold air will be ushered into the CWA on gusty westerly winds. Even with clearing skies the cold air advection will overwhelm what little warming the sun will provide. As such temperatures will struggle to warm much past 60 over the western half of the CWA. Saturday night promises a need to turn on your furnace as deep cold air advection continues with h8 temperatures around 0C possible. Should see some lows fall into the upper 30s across northern MO. .LONG TERM...(Sunday through Thursday) Issued at 414 AM CDT FRI OCT 4 2013 Model differences in the beginning of the extended period will make for a tricky forecast on Sunday. The associated upper level trough, that will be responsible for driving a cold front through the area Friday night into Saturday morning, will develop a cut off low in the base of the trough. This upper low will be a slow mover and by Sunday is expected to be moving north of the CWA. However, models are different as to the placement of the low. The EC and GFS ensemble mean are the slowest and furthest south taking the upper low across Iowa on the day Sunday. The operational GFS and GEM are further north and more progressive with the upper low. The GEM and operational GFS would lead to a dry and slightly warmer solution whereas, the GFS ensemble and EC solution would be cooler with even a chance for some light precipitation across northern Missouri. for now, sided with the ALLBlend which is a compromise solution in keeping conditions dry with highs in the upper 50 and lower 60s. As surface high pressure builds in Sunday night temperatures will bottom out in the lower 40s. Beyond Sunday, the general trend amongst models is similar in keeping conditions dry with a warming trend. Monday will be a transitional day with northwest flow aloft behind the departing upper level system. A return to southwesterly flow and plentiful sunshine should allow highs to warm into the mid 60s to near 70. Tuesday, an upper level ridge will begin to build into the area in response to an upper level trough digging southward down the western CONUS. This upper level ridge is expected to dominate the area as well as much of the eastern half of the CONUS through Thursday. Highs will warm through the middle part of the week with highs in the mid to upper 70s by Thursday. && .AVIATION...(For the 12Z TAFS through 12Z Saturday Morning) Issued at 651 AM CDT FRI OCT 4 2013 Band of scattered showers and storms will affect far northwest MO and northeast KS this morning, missing the Kansas City terminals and may pass just to the west of KSTJ. MVFR stratus has formed in the very humid airmass and latest BUFR soundings indicate these ceilings will linger into the late morning before lifting. Attention then turns to this evening when a band of strong/possibly severe storms forms along a cold front. Models are in good agreement with timing giving a boost to confidence. Expect showers and storms to pass through the terminals during the evening hours. VFR ceilings most likely except with the heavy showers which could lower ceilings to MVFR with IFR visibilities. Frontal passage likely with initial line of storms but convection will linger well past the passage of the front. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ SHORT TERM...MJ LONG TERM...73 AVIATION...MJ
AREA FORECAST DISCUSSION...CORRECTED
NWS KANSAS CITY/PLEASANT HILL MO
435 AM CDT FRI OCT 4 2013 .SHORT TERM...(TODAY THROUGH SATURDAY) ISSUED AT 414 AM CDT FRI OCT 4 2013 THE NEXT 24 HOURS WILL BE A TALE OF TWO AIR MASSES, ONE MORE COMMON DURING MID-SUMMER AND THE OTHER MORE LIKE LATE FALL. MUCH BETTER AGREEMENT BETWEEN THE MODELS ON TIMING OF THE COLD FRONT AS WELL AS THE PLACEMENT OF THE UPPER LEVEL TROUGH LENDS TO A MORE CONFIDENT FORECAST AND INCREASE IN POPS WITH THE FRONTAL BOUNDARY. FOR TODAY A STRONG UPPER TROUGH OVER THE GREAT BASIN CENTERED JUST EAST OF SLC WILL LIFT NORTHEAST AND INTO THE NORTHERN AND CENTRAL PLAINS BY SATURDAY. INCREASING DOWNSTREAM PRESSURE FALLS HAVE ALREADY INDUCED A SURFACE LOW OVER NORTHWEST KS WHICH WILL DEEPEN AND LIKEWISE TRACK NORTHEAST AS THE INCREASING DYNAMICS ALOFT OVERSPREAD THE PLAINS. A LARGE WARM SECTOR EXISTS EAST OF THE CENTRAL ROCKIES WITH AN IMPRESSIVE SOUTHWESTERLY LOW LEVEL JET IN EXCESS OF 50KTS EXTENDING THROUGH OK, KS AND WESTERN MO. A NARROW BAND OF SCATTERED ELEVATED CONVECTION HAS FORMED AS THE RIGHT REAR QUAD OF A 70KT WIND MAX AT 200MB ENCOUNTERS AN AXIS OF MLCAPES AROUND 1000 J/KG ALIGNED NEAR THE LOW LEVEL JET AXIS. EARLIER VERSIONS OF THE HRRR AND THE 00Z NAM DID A GOOD JOB OF FORECASTING THIS ACTIVITY. EXPECT THIS CONVECTION TO SPREAD ACROSS NORTHWEST MO AND NORTHEAST KS THIS MORNING BEFORE WEAKENING TOWARDS THE NOON HOUR. THE AFTERNOON HOURS SHOULD BE MAINLY DRY EXCEPT FOR LATE IN THE DAY OVER NORTHWEST MO. TEMPERATURES WILL BE IMPACTED BY THE INCREASING MID LEVEL CLOUD COVER THIS MORNING AND THE CONVECTION OVER NORTHWEST MO. HOWEVER, SHOULD SEE CLOUDS SCATTER OUT THIS AFTERNOON AND ALLOW GOOD MIXING TO REACH HIGHS WELL INTO THE 80S. THE WEATHER WILL BECOME QUITE ACTIVE THIS EVENING AS A CONVECTION RAPIDLY FORMS ALONG A COLD FRONT OVER KS AND SOUTHEAST NE. THIS BOUNDARY IS ATTACHED TO THE LOW PRESSURE CENTER AND WILL SWING EASTWARD THROUGH THE CWA. GIVEN A MODERATE TO HIGHLY UNSTABLE AIRMASS WITH OVER 2000 J/KG OF MLCAPE PLUS THE ABOVE NOTED H8 JET AND STEEPENING MID LEVEL LAPSE RATES DUE TO COLD AIR ALOFT OVERSPREADING THE REGION, THE CAP NOW IN PLACE WILL BE LIFTED ALLOWING FOR RAPID DEVELOPMENT OF CONVECTION ALONG THE FRONTAL BOUNDARY. EXPECT THIS ACTIVITY TO FORM OVER EASTERN KS AND SOUTHEAST NE BY LATE AFTERNOON AND ENTER THE FAR NORTHWEST CWA AROUND 00Z. SEVERE STORMS WILL BE POSSIBLE THIS EVENING MAINLY WEST OF THE I-35 CORRIDOR WITH LARGE HAIL AND DAMAGING WINDS INITIALLY AND AS THE SQUALL LINE MATURES EVOLVING INTO A HIGH WIND THREAT. WITH PRECIPITABLE WATER VALUES PROGGED CLOSE TO TWO STANDARD DEVIATIONS ABOVE NORMAL ANY TRAINING CELLS WILL PRODUCE VERY HEAVY RAINFALL. THIS MAY BE ESPECIALLY TRUE AFTER MIDNIGHT AS THE NAM HINTS AT POST FRONTAL ELEVATED CONVECTION FORMING DUE TO INCREASING FRONTOGENESIS WITHIN THE 850-750MB LAYER. WHILE THE COLD FRONT IS EXPECTED TO CLEAR THE CWA BY SATURDAY MORNING THE POST FRONTAL STRATIFORM RAIN WITH EMBEDDED THUNDER WILL LIKELY LINGER THROUGH SATURDAY MORNING OVER THE EASTERN HALF OF THE CWA. A MAJOR INFLUX OF COLD AIR WILL BE USHERED INTO THE CWA ON GUSTY WESTERLY WINDS. EVEN WITH CLEARING SKIES THE COLD AIR ADVECTION WILL OVERWHELM WHAT LITTLE WARMING THE SUN WILL PROVIDE. AS SUCH TEMPERATURES WILL STRUGGLE TO WARM MUCH PAST 60 OVER THE WESTERN HALF OF THE CWA. SATURDAY NIGHT PROMISES A NEED TO TURN ON YOUR FURNACE AS DEEP COLD AIR ADVECTION CONTINUES WITH H8 TEMPERATURES AROUND 0C POSSIBLE. SHOULD SEE SOME LOWS FALL INTO THE UPPER 30S ACROSS NORTHERN MO. .LONG TERM...(SUNDAY THROUGH THURSDAY) ISSUED AT 414 AM CDT FRI OCT 4 2013 MODEL DIFFERENCES IN THE BEGINNING OF THE EXTENDED PERIOD WILL MAKE FOR A TRICKY FORECAST ON SUNDAY. THE ASSOCIATED UPPER LEVEL TROUGH, THAT WILL BE RESPONSIBLE FOR DRIVING A COLD FRONT THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY MORNING, WILL DEVELOP A CUT OFF LOW IN THE BASE OF THE TROUGH. THIS UPPER LOW WILL BE A SLOW MOVER AND BY SUNDAY IS EXPECTED TO BE MOVING NORTH OF THE CWA. HOWEVER, MODELS ARE DIFFERENT AS TO THE PLACEMENT OF THE LOW. THE EC AND GFS ENSEMBLE MEAN ARE THE SLOWEST AND FURTHEST SOUTH TAKING THE UPPER LOW ACROSS IOWA ON THE DAY SUNDAY. THE OPERATIONAL GFS AND GEM ARE FURTHER NORTH AND MORE PROGRESSIVE WITH THE UPPER LOW. THE GEM AND OPERATIONAL GFS WOULD LEAD TO A DRY AND SLIGHTLY WARMER SOLUTION WHEREAS, THE GFS ENSEMBLE AND EC SOLUTION WOULD BE COOLER WITH EVEN A CHANCE FOR SOME LIGHT PRECIPITATION ACROSS NORTHERN MISSOURI. FOR NOW, SIDED WITH THE ALLBLEND WHICH IS A COMPROMISE SOLUTION IN KEEPING CONDITIONS DRY WITH HIGHS IN THE UPPER 50 AND LOWER 60S. AS SURFACE HIGH PRESSURE BUILDS IN SUNDAY NIGHT TEMPERATURES WILL BOTTOM OUT IN THE LOWER 40S. BEYOND SUNDAY, THE GENERAL TREND AMONGST MODELS IS SIMILAR IN KEEPING CONDITIONS DRY WITH A WARMING TREND. MONDAY WILL BE A TRANSITIONAL DAY WITH NORTHWEST FLOW ALOFT BEHIND THE DEPARTING UPPER LEVEL SYSTEM. A RETURN TO SOUTHWESTERLY FLOW AND PLENTIFUL SUNSHINE SHOULD ALLOW HIGHS TO WARM INTO THE MID 60S TO NEAR 70. TUESDAY, AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD INTO THE AREA IN RESPONSE TO AN UPPER LEVEL TROUGH DIGGING SOUTHWARD DOWN THE WESTERN CONUS. THIS UPPER LEVEL RIDGE IS EXPECTED TO DOMINATE THE AREA AS WELL AS MUCH OF THE EASTERN HALF OF THE CONUS THROUGH THURSDAY. HIGHS WILL WARM THROUGH THE MIDDLE PART OF THE WEEK WITH HIGHS IN THE MID TO UPPER 70S BY THURSDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY MORNING) ISSUED AT 428 AM CDT FRI OCT 4 2013 HAVE UPDATED THE KSTJ FORECAST TO ACCOUNT FOR THE BAND OF SCATTERED CONVECTION WHICH HAS FORMED OVER CENTRAL KS. A COUPLE OF THE SHORT TERM CONVECTIVE ALLOWING MODELS HAD PICKED UP ON THIS DEVELOPMENT BEFORE IT FORMED AND GIVEN THE LATEST RADAR AND SATELLITE TRENDS THIS ACTIVITY WILL TRACK INTO NORTHWEST MO THIS MORNING. THE CONVECTION WILL LIKELY REMAIN HIGH-BASED BUT MVFR VISIBILITIES MAY MATERIALIZE DUE TO THE HEAVY RAINS ASSOCIATED WITH THE HIGHLY CONCENTRATED REFLECTIVITIES. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ SHORT TERM...MJ LONG TERM...73 AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
432 AM CDT Fri Oct 4 2013 .SHORT TERM...(Today through Saturday) Issued at 414 AM CDT FRI OCT 4 2013 The next 48 hours will be a tale of two air masses, one more common during mid-summer and the other more like late Fall. Much better agreement between the models on timing of the cold front as well as the placement of the upper level trough lends to a more confident forecast and increase in PoPs with the frontal boundary. For today a strong upper trough over the Great Basin centered just east of SLC will lift northeast and into the Northern and Central Plains by Saturday. Increasing downstream pressure falls have already induced a surface low over northwest KS which will deepen and likewise track northeast as the increasing dynamics aloft overspread the Plains. A large warm sector exists east of the Central Rockies with an impressive southwesterly low level jet in excess of 50kts extending through OK, KS and western MO. A narrow band of scattered elevated convection has formed as the right rear quad of a 70kt wind max at 200mb encounters an axis of MLCAPES around 1000 J/kg aligned near the low level jet axis. Earlier versions of the HRRR and the 00Z NAM did a good job of forecasting this activity. Expect this convection to spread across northwest MO and northeast KS this morning before weakening towards the noon hour. The afternoon hours should be mainly dry except for late in the day over northwest MO. Temperatures will be impacted by the increasing mid level cloud cover this morning and the convection over northwest MO. However, should see clouds scatter out this afternoon and allow good mixing to reach highs well into the 80s. The weather will become quite active this evening as a convection rapidly forms along a cold front over KS and southeast NE. This boundary is attached to the low pressure center and will swing eastward through the CWA. Given a moderate to highly unstable airmass with over 2000 J/kg of MLCAPE plus the above noted h8 jet and steepening mid level lapse rates due to cold air aloft overspreading the region, the cap now in place will be lifted allowing for rapid development of convection along the frontal boundary. Expect this activity to form over eastern KS and southeast NE by late afternoon and enter the far northwest CWA around 00Z. Severe storms will be possible this evening mainly west of the I-35 corridor with large hail and damaging winds initially and as the squall line matures evolving into a high wind threat. With precipitable water values progged close to two standard deviations above normal any training cells will produce very heavy rainfall. This may be especially true after midnight as the NAM hints at post frontal elevated convection forming due to increasing frontogenesis within the 850-750mb layer. While the cold front is expected to clear the CWA by Saturday morning the post frontal stratiform rain with embedded thunder will likely linger through Saturday morning over the eastern half of the CWA. A major influx of cold air will be ushered into the CWA on gusty westerly winds. Even with clearing skies the cold air advection will overwhelm what little warming the sun will provide. As such temperatures will struggle to warm much past 60 over the western half of the CWA. Saturday night promises a need to turn on your furnace as deep cold air advection continues with h8 temperatures around 0C possible. Should see some lows fall into the upper 30s across northern MO. .LONG TERM...(Sunday through Thursday) Issued at 414 AM CDT FRI OCT 4 2013 Model differences in the beginning of the extended period will make for a tricky forecast on Sunday. The associated upper level trough, that will be responsible for driving a cold front through the area Friday night into Saturday morning, will develop a cut off low in the base of the trough. This upper low will be a slow mover and by Sunday is expected to be moving north of the CWA. However, models are different as to the placement of the low. The EC and GFS ensemble mean are the slowest and furthest south taking the upper low across Iowa on the day Sunday. The operational GFS and GEM are further north and more progressive with the upper low. The GEM and operational GFS would lead to a dry and slightly warmer solution whereas, the GFS ensemble and EC solution would be cooler with even a chance for some light precipitation across northern Missouri. for now, sided with the ALLBlend which is a compromise solution in keeping conditions dry with highs in the upper 50 and lower 60s. As surface high pressure builds in Sunday night temperatures will bottom out in the lower 40s. Beyond Sunday, the general trend amongst models is similar in keeping conditions dry with a warming trend. Monday will be a transitional day with northwest flow aloft behind the departing upper level system. A return to southwesterly flow and plentiful sunshine should allow highs to warm into the mid 60s to near 70. Tuesday, an upper level ridge will begin to build into the area in response to an upper level trough digging southward down the western CONUS. This upper level ridge is expected to dominate the area as well as much of the eastern half of the CONUS through Thursday. Highs will warm through the middle part of the week with highs in the mid to upper 70s by Thursday. && .AVIATION...(For the 06Z TAFS through 06Z Saturday Morning) Issued at 428 AM CDT FRI OCT 4 2013 Have updated the KSTJ forecast to account for the band of scattered convection which has formed over central KS. A couple of the short term convective allowing models had picked up on this development before it formed and given the latest radar and satellite trends this activity will track into northwest MO this morning. The convection will likely remain high-based but MVFR visibilities may materialize due to the heavy rains associated with the highly concentrated reflectivities. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ SHORT TERM...MJ LONG TERM...73 AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
418 AM CDT Fri Oct 4 2013 .SHORT TERM...(Today through Saturday) Issued at 414 AM CDT FRI OCT 4 2013 The next 48 hours will be a tale of two airmasses, one more common during mid-summer and the other more like late Fall. Much better agreement between the models on timing of the cold front as well as the placement of the upper level trough lends to a more confident forecast and increase in PoPs with the frontal boundary. For today a strong upper trough over the Great Basin centered just east of SLC will lift northeast and into the Northern and Central Plains by Saturday. Increasing downstream pressure falls have already induced a surface low over northwest KS which will deepen and likewise track northeast as the increasing dynamics aloft overspread the Plains. A large warm sector exists east of the Central Rockies with an impressive southwesterly low level jet in excess of 50kts extending through OK, KS and western MO. A narrow band of scattered elevated convection has formed as the right rear quad of a 70kt wind max at 200mb encounters an axis of MLCAPES around 1000 J/kg aligned near the low level jet axis. Earlier versions of the HRRR and the 00Z NAM did a good job of forecasting this activity. Expect this convection to spread across northwest MO and northeast KS this morning before weakening towards the noon hour. The afternoon hours should be mainly dry except for late in the day over northwest MO. Temperatures will be impacted by the increasing mid level cloud cover this morning and the convection over northwest MO. However, should see clouds scatter out this afternoon and allow good mixing to reach highs well into the 80s. The weather will become quite active this evening as a convection rapidly forms along a cold front over KS and southeast NE. This boundary is attached to the low pressure center and will swing eastward through the CWA. Given a moderate to highly unstable airmass with over 2000 J/kg of MLCAPE plus the above noted h8 jet and steepening mid level lapse rates due to cold air aloft overspreading the region, the cap now in place will be lifted allowing for rapid development of convection along the frontal boundary. Expect this activity to form over eastern KS and southeast NE by late afternoon and enter the far northwest CWA around 00Z. Severe storms will be possible this evening mainly west of the I-35 corridor with large hail and damaging winds initially and as the squall line matures evolving into a high wind threat. With precipitable water values progged close to two standard deviations above normal any training cells will produce very heavy rainfall. This may be especially true after midnight as the NAM hints at post frontal elevated convection forming due to increasing frontogenesis within the 850-750mb layer. While the cold front is expected to clear the CWA by Saturday morning the post frontal stratiform rain with embedded thunder will likely linger through Saturday morning over the eastern half of the CWA. A major influx of cold air will be ushered into the CWA on gusty westerly winds. Even with clearing skies the cold air advection will overwhelm what little warming the sun will provide. As such temperatures will struggle to warm much past 60 over the western half of the CWA. Saturday night promises a need to turn on your furnace as deep cold air advection continues with h8 temperatures around 0C possible. Should see some lows fall into the upper 30s across northern MO. .LONG TERM...(Sunday through Thursday) Issued at 414 AM CDT FRI OCT 4 2013 Model differences in the beginning of the extended period will make for a tricky forecast on Sunday. The associated upper level trough, that will be responsible for driving a cold front through the area Friday night into Saturday morning, will develop a cut off low in the base of the trough. This upper low will be a slow mover and by Sunday is expected to be moving north of the CWA. However, models are different as to the placement of the low. The EC and GFS ensemble mean are the slowest and furthest south taking the upper low across Iowa on the day Sunday. The operational GFS and GEM are further north and more progressive with the upper low. The GEM and operational GFS would lead to a dry and slightly warmer solution whereas, the GFS ensemble and EC solution would be cooler with even a chance for some light precipitation across northern Missouri. for now, sided with the ALLBlend which is a compromise solution in keeping conditions dry with highs in the upper 50 and lower 60s. As surface high pressure builds in Sunday night temperatures will bottom out in the lower 40s. Beyond Sunday, the general trend amongst models is similar in keeping conditions dry with a warming trend. Monday will be a transitional day with northwest flow aloft behind the departing upper level system. A return to southwesterly flow and plentiful sunshine should allow highs to warm into the mid 60s to near 70. Tuesday, an upper level ridge will begin to build into the area in response to an upper level trough digging southward down the western CONUS. This upper level ridge is expected to dominate the area as well as much of the eastern half of the CONUS through Thursday. Highs will warm through the middle part of the week with highs in the mid to upper 70s by Thursday. && .AVIATION...(For the 06Z TAFS through 06Z Friday Night) Issued at 1207 AM CDT FRI OCT 4 2013 Widespread storms over Nebraska and Iowa will generally remain north of the STJ-IRK corridor tonight and are not expected to have impacts on the KC area. There is a slight chance for a band of showers to develop toward sunrise near the ICT-MCI corridor, but these would be light and of minimal impact. Chances for this are only running around 20-30 percent so did not add any mention to the TAFs for now. Confidence is high that a line of storms will track out of eastern KS into western MO after 00Z and quickly race into central MO overnight. This line of storms should be moving fast enough that only a couple of hours of thunder are expected at a given terminal. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ SHORT TERM...MJ LONG TERM...73 AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1208 AM CDT Fri Oct 4 2013 .UPDATE... Issued at 834 PM CDT THU OCT 3 2013 Strengthening low-level jet over KS and MO has led to scattered thunderstorm development over its nose over southern parts of Nebraska and Iowa. This region will be the primary focus for thunderstorm development tonight as the LLJ continues to strengthen and isentropic ascent increases. RAP and NAM bring some convergence at the nose of this jet a bit further south into far northern MO later this evening, and it wouldn`t be surprising to see a few cells make it into northern parts of the forecast area through midnight. However, the window for thunderstorm development should end shortly after midnight as a strong EML evident on the 00Z TOP RAOB begins to overspread the area and cuts off any available instability. Given MUCAPE around 1500 J/kg and modest effective shear, a few strong storms are possible with large hail the main threat. Therefore severe thunderstorm watch 537 has been issued through 5 AM CDT for far northern Missouri. However given the cap that will overspread the area after midnight, this watch may need to be expired early for northern MO as the main severe threat pushes farther north into Iowa. && .SHORT TERM...(This Evening through Friday Night) Issued at 318 PM CDT THU OCT 3 2013 20Z surface observations showed a synoptic stationary front anchored from NW KS through eastern Nebraska into NW Iowa. A secondary warm front, associated with reinforced convective outflow, arced southeast from north central KS into Mid Missouri. Strong pressure falls over ern KS/wrn MO suggest that convectively induced wind field will erode quickly, with strong southerly flow quickly becoming re-established over the area. This should allow unseasonably warm/moist air over central/srn MO to spread quickly northward this afternoon/evening, aided aloft by a developing low level jet. For tonight, models generally lack QPF over the area, but a closer inspection yields rather robust isentropic lift by mid evening as the developing low level jet ascends warm/moist air atop the retreating warm front. Have painted an area of 20-25% POPs across the northern half of the CWA by 03Z, with the area slowly retreating northward overnight. Given the current boundary placement, would not be surprised to see isolated activity initiate further south. The only thing precluding higher POPs is the expectation that low level flow will become more uniform over the next several hours, eliminating the strong convergence currently in place over the srn CWA. On Friday, very warm and humid conditions will overspread the area as a surface low rapidly deepens from SW KS into south central Nebraska by 00Z. Strong southerly winds approaching 30 mph will continue to transport Gulf air into the region, promoting considerable shallow Cu development. This may be the only thing keeping temperatures from breaking the 90 degree mark (record for KC is 92 in 1938), which is still not entirely out of the question. Large scale height falls will begin to overspread the eastern Plains by late afternoon as the mid level cyclone matures to a whopping 546 dm at 500mb. This will eliminate any mid level capping, allowing the surface cold front/dryline to realize 2000+ J/kg of MLCAPE that will be yielded by upper 80F temperatures and mid-upper 60F dewpoint. Boundary parallel deep layer shear, augmented by an impressive 80-90kt 500mb jet streak, will likely result in rapid upscale growing into a frontal squall line over eastern KS. 12Z model guidance has jumped toward the consistent, but faster NAM-WRF, advancing the cold front through the CWA tomorrow evening. Although better 700-500mb flow will be focused into nrn IA/srn MN, sufficient deep layer shear will exist over wrn MO/ern KS (mainly west of I-35) to support damaging wind gusts as cells race off toward the northeast. Hodographs suggest that storms may be able to remain along/ahead of the undercutting cold front, which would certainly amplify any embedded severe weather potential through 03Z before stabilization occurs. .LONG TERM...(Saturday through Thursday) Issued at 318 PM CDT THU OCT 3 2013 Saturday - Sunday: A drastic change in conditions from those of Friday are to be expected for the upcoming weekend. By daybreak Saturday the cold front will have swept across much of Missouri, with strong cold advection aloft beginning to push into the area. Daybreak temperatures in the 40s to low 50s will struggle to climb given the cold advection aloft and increased afternoon strato-cu. Many areas will fail to reach 60 degrees. Some model discrepancies appear on Sunday regarding the depth and track of the upper low through the Midwest. The ECMWF remains slightly deeper and the resultant slowdown in forward progression would keep higher cloud cover over the northern CWA. The GFS/NAM both suggest a slightly more progressive solution, keeping the majority of cloud cover north of the CWA. Again, given existing cold air aloft, feel we`ll again struggle to reach the lower 60s. Monday - Thursday: The good news is that the blustery conditions of the weekend will be short-lived as heights quickly begin to rise in the wake of the departing upper trough. Once again, a deepening trough in the southwestern CONUS will lead to a return of southwesterly low-level flow aloft. With dry conditions prevailing, temperatures are again expected to climb above normal for much of next week. && .AVIATION...(For the 06Z TAFS through 06Z Friday Night) Issued at 1207 AM CDT FRI OCT 4 2013 Widespread storms over Nebraska and Iowa will generally remain north of the STJ-IRK corridor tonight and are not expected to have impacts on the KC area. There is a slight chance for a band of showers to develop toward sunrise near the ICT-MCI corridor, but these would be light and of minimal impact. Chances for this are only running around 20-30 percent so did not add any mention to the TAFs for now. Confidence is high that a line of storms will track out of eastern KS into western MO after 00Z and quickly race into central MO overnight. This line of storms should be moving fast enough that only a couple of hours of thunder are expected at a given terminal. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ UPDATE...Hawblitzel SHORT TERM...Bookbinder LONG TERM...Dux AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
315 PM MDT FRI OCT 4 2013 .DISCUSSION... FRONT HAS BEEN HUNG UP JUST NORTH OF THE UNION COUNTY BORDER ALL DAY...ALTHOUGH THE LOW CLOUDS ASSOCIATED WITH IT LAST NIGHT HAVE DISSIPATED OVER SOUTHEAST AND EAST CENTRAL CO. RUC INDICATES THE BOUNDARY TO PLUNGE SWD WITHIN THE NEXT 3 HOURS. IT ALSO INDICATES A LITTLE MORE MOISTURE OVER PARTS OF THE NORTHEAST...AND RESULT HAS BEEN TO UPGRADE SKY COVER TO PARTLY CLOUDY RATHER THAN CLEAR. STILL MODELS NOT SUGGESTING A HUGE UPTICK IN DEWPOINTS THERE OVERNIGHT. NORTHERLY WINDS ASSOCIATED WITH THE FRONT AS IT TRACKS THROUGH THE PLAINS TO BE GUSTY BUT NOT QUITE AS STRONG AS INDICATED 24 HOURS AGO. AS FOR FREEZE HIGHLIGHTS...STILL SOME MARGINAL TEMPERATURES FOR PORTIONS OF THE EAST CENTRAL AND RGV AS WELL AS THE SOUTH CENTRAL HIGHLANDS. AND SATURDAY NIGHT TEMPERATURE GUIDANCE IS STILL LEANING TOWARDS SOME WARMING. FORECAST BOUNDARY LAYER WINDS TONIGHT NORTHEAST OVER THE PLAINS BUT FOR SATURDAY NIGHT THE GFS FORECASTS A MORE WLY WIND FLOW IN THE LOWER LEVELS...AS OPPOSED TO THE NAM/S LIGHT AND VRBL TO WEAK NW WINDS. FORECAST SOUNDINGS INDICATE SOME STEEP INVERSIONS OFF THE DECK AT SELECTED POINTS SATURDAY NIGHT BUT OVERALL THE SOUNDINGS EXHIBIT A WARMING TREND. THINK THERE MAY BE SOME POINTS IN SHELTERED AREAS UNAFFECTED BY WIND THAT COULD REACH THE MAGIC 32 OR SLIGHTLY BELOW OUTSIDE OF OUR FORECAST POINTS TONIGHT...SO WENT AHEAD AND UPGRADED REMAINING EAST CENTRAL ZONES IN THE WATCH. ALSO ADDED THE SOUTH CENTRAL HIGHLANDS TO THE WARNING TONIGHT WITH FORECAST LOWS AGAIN HOVERING NEAR THE FREEZING MARK. BASED ON THE ABOVE MODEL DISCUSSION...HAVE HELD OFF ON ISSUING FURTHER FREEZE HIGHLIGHTS FOR SATURDAY NIGHT. WILL WAIT TO SEE WHAT THE GUIDANCE DOES AS WELL AS WHAT MINS TONIGHT DO. WINDS STILL TO TAPER OFF SATURDAY WITH A WARMING TREND SUNDAY THROUGH TUESDAY. MODELS CONTINUE TO FOCUS ON AN UPPER LOW DIGGING INTO THE SW US AROUND THE MID TO LATE WEEK PERIOD NEXT WEEK. WINDS LOOK TO INCREASE TUESDAY AND MORESO WEDNESDAY WITH TEMPERATURES FALLING THURSDAY/FRIDAY. WE NOW HAVE SOME MEAGER POPS FOR THE NORTH AND WEST DURING THIS PERIOD...BUT MODELS NOT EXACTLY IN AGREEMENT HOW THIS WILL PLAY OUT. && .FIRE WEATHER... CURRENT FIRE WEATHER HIGHLIGHTS ARE MARGINAL BUT WILL KEEP THEM RUNNING THROUGH EVENT EXPIRATION. TUCUMCARI IS SHOWING NEAR RED FLAG CONDITIONS WITH GUSTY WINDS AND TEEN HUMIDITY. THE UPPER LOW WHICH IS CURRENTLY OVER THE CENTRAL ROCKIES AND GREAT PLAINS WILL GRADUALLY SHIFT EASTWARD THE REST OF TODAY...TONIGHT INTO SATURDAY. THE SURFACE WIND FLOW WILL GENERALLY RELAX AS A RESULT ALTHOUGH A BACK DOOR COLD FRONT WILL PUSH ACROSS THE EASTERN PLAINS TONIGHT AND INCREASE WINDS FOR A TIME. A CHILLY NIGHT IS IN STORE WITH FREEZING TO NEAR FREEZING TEMPERATURES EXPECTED ACROSS THE MAJORITY OF THE FIRE WEATHER FORECAST AREA. A HARD FREEZE WILL BE FELT ACROSS THE NORTHERN AND WESTERN MOUNTAINS AND INCLUDE SOME LOWLAND SITES AS WELL. HIGH PRESSURE WILL BE IN CONTROL DURING THE WEEKEND. THE SURFACE WIND FLOW WILL BE MUCH MORE RELAXED ALTHOUGH LOOK FOR SOME NORTHERLY BREEZES ACROSS SOME WESTERN AND CENTRAL AREAS SATURDAY AFTERNOON. THE FLOW ALOFT WILL BE MUCH WEAKER SO MAINLY SURFACE DRIVEN. FAIRLY LIGHT WINDS FOR SUNDAY WITH JUST A FEW BREEZES ALONG INTERSTATE 25 BETWEEN LAS VEGAS TO RATON. MIXING HEIGHTS WILL BE ON THE LOWER SIDE THANKS TO POST COLD FRONTAL INVERSION EFFECTS. THUS VENTILATION RATES WILL BE LOWER. VENTILATION WILL BE THE POOREST ON SUNDAY. EXPECTING A STRONG LOW LEVEL RADIATION INVERSION TO DEVELOP SATURDAY NIGHT. THIS WILL BE ACCOMPANIED BY ADDITIONAL FREEZING TEMPERATURES WITHIN BASINS AND VALLEYS. HIGH TEMPERATURES WILL BE WELL BELOW NORMAL SATURDAY AND BE AROUND 5 TO 10 DEGREES BELOW NORMAL SUNDAY AFTERNOON. HUMIDITY VALUES WILL BE NEAR SEASONABLE LEVELS ON SATURDAY BUT LOWER ON SUNDAY WITH LOTS OF MINIMUM VALUES IN THE TEENS. A MID LEVEL DRY INTRUSION PLUS A WARM UP WILL BE THE CATALYST FOR LOWER HUMIDITY VALUES SUNDAY. WEATHER MODELS REMAIN PERSISTENT WITH DEPICTING RIDGING ON MONDAY AND THEN BREAKING DOWN OR SHIFTING EASTWARD ON TUESDAY. TEMPERATURES WOULD CONTINUE TO WARM WHILE THE UPPER FLOW TURNS MORE SOUTHWESTERLY ON TUESDAY. DRY CONDITIONS WOULD CONTINUE. VENTILATION RATES WILL REMAIN ON THE LOWER SIDE MONDAY ALTHOUGH IMPROVE IN A FEW AREAS COMPARED TO SUNDAY/S READINGS. TRANSPORT WINDS WILL INCREASE TUESDAY SO THE VENTILATION WILL IMPROVE SIGNIFICANTLY THEN. NEAR TO ABOVE NORMAL TEMPERATURES EXPECTED EARLY NEXT WEEK AND SURFACE HUMIDITY WILL REMAIN ON THE LOWER SIDE. CURRENTLY HAVE SOME LOCALIZED CRITICAL FIRE WEATHER GROWTH CONDITIONS DEPICTED WITHIN OUR GRIDDED FORECAST TUESDAY AFTERNOON ACROSS THE NORTHEAST SO WILL BE MONITORING THAT TREND. THE LATEST LONG RANGE MODELS CONTINUE TO SHOW A BREEZY TO WINDY PATTERN WEDNESDAY THROUGH FRIDAY AS ANOTHER PACIFIC TROUGH CROSSES OVER THE INTERMOUNTAIN WEST. IT STILL APPEARS TO BE A DRY TROUGH PASSAGE FOR THE FORECAST AREA. THUS...CANT RULE OUT SOME CRITICAL FIRE WEATHER AREAS...MOST LIKELY FAVORING THE EAST...WHERE TEMPERATURES WOULD BE ABOVE NORMAL FOR THE LONGEST. COOLING EXPECTED ACROSS THE WEST ON THURSDAY AND SPREAD ACROSS THE ENTIRE AREA ON FRIDAY. THIS AIRMASS APPEARS TO BE LESS CHILLY COMPARED TO THE CURRENT ONE. VENTILATION WOULD BE QUITE HIGH WEDNESDAY AND THURSDAY AND PROBABLY LOWER SOME ON FRIDAY. CONFIDENCE IS AT LEAST MODERATE FOR THIS SCENARIO. && .AVIATION... 18Z TAF CYCLE TRADITIONAL COLD FRONT CURRENTLY FINISHING ITS SWEEP ACROSS THE FORECAST AREA LATE THIS MORNING. THE WINDS ALOFT WILL BE WEAKENING BUT THE SURFACE PRESSURE GRADIENT WILL REMAIN QUITE STRONG. LOOK FOR STEADY ALTHOUGH SOMEWHAT DECREASING WIND BY LATE AFTERNOON. GUST TO AROUND 30 KT WILL BE OBSERVED AT LVS AND TCC THROUGH MOST OF THE AFTERNOON. THE MAIN BACK DOOR COLD FRONT WILL PLUNGE SOUTHWARD TONIGHT AND EFFECT LVS/TCC AND ROW. THE MAIN EFFECT WILL BE AN ABRUPT NORTHERLY WIND SHIFT. THE ATMOSPHERE IS PRETTY DRY SO CIGS AND VIS SHOULD NOT BE AN ISSUE THE NEXT 24 HOURS. 50 && .PRELIMINARY POINT TEMPS/POPS... FARMINGTON...................... 27 58 27 66 / 0 0 0 0 DULCE........................... 22 55 23 63 / 0 0 0 0 CUBA............................ 23 55 26 65 / 0 0 0 0 GALLUP.......................... 20 58 21 67 / 0 0 0 0 EL MORRO........................ 19 55 21 65 / 0 0 0 0 GRANTS.......................... 21 57 22 68 / 0 0 0 0 QUEMADO......................... 25 62 25 68 / 0 0 0 0 GLENWOOD........................ 30 69 28 74 / 0 0 0 0 CHAMA........................... 20 52 26 60 / 0 0 0 0 LOS ALAMOS...................... 27 56 34 65 / 0 0 0 0 PECOS........................... 27 55 33 64 / 0 0 0 0 CERRO/QUESTA.................... 17 53 23 64 / 0 0 0 0 RED RIVER....................... 17 44 18 56 / 5 5 0 0 ANGEL FIRE...................... 20 53 20 62 / 5 0 0 0 TAOS............................ 19 56 21 65 / 0 0 0 0 MORA............................ 23 55 25 66 / 0 0 0 0 ESPANOLA........................ 21 60 28 70 / 0 0 0 0 SANTA FE........................ 23 55 30 65 / 0 0 0 0 SANTA FE AIRPORT................ 26 58 30 68 / 0 0 0 0 ALBUQUERQUE FOOTHILLS........... 32 57 37 68 / 0 0 0 0 ALBUQUERQUE HEIGHTS............. 36 60 36 69 / 0 0 0 0 ALBUQUERQUE VALLEY.............. 30 61 31 71 / 0 0 0 0 ALBUQUERQUE WEST MESA........... 30 60 32 71 / 0 0 0 0 LOS LUNAS....................... 33 63 31 71 / 0 0 0 0 RIO RANCHO...................... 31 61 33 71 / 0 0 0 0 SOCORRO......................... 36 65 37 73 / 0 0 0 0 SANDIA PARK/CEDAR CREST......... 30 56 37 67 / 0 0 0 0 TIJERAS......................... 30 58 38 67 / 0 0 0 0 MORIARTY/ESTANCIA............... 27 57 29 65 / 0 0 0 0 CLINES CORNERS.................. 28 56 33 65 / 0 0 0 0 GRAN QUIVIRA.................... 31 60 34 66 / 0 0 0 0 CARRIZOZO....................... 35 63 35 67 / 0 0 0 0 RUIDOSO......................... 39 57 32 62 / 0 0 0 0 CAPULIN......................... 20 54 22 67 / 0 0 0 0 RATON........................... 24 58 24 70 / 0 0 0 0 SPRINGER........................ 23 56 27 71 / 0 0 0 0 LAS VEGAS....................... 24 54 29 67 / 0 0 0 0 CLAYTON......................... 29 62 35 71 / 0 0 0 0 ROY............................. 27 59 33 69 / 0 0 0 0 CONCHAS......................... 33 62 33 73 / 0 0 0 0 SANTA ROSA...................... 33 63 34 73 / 0 0 0 0 TUCUMCARI....................... 34 64 34 75 / 0 0 0 0 CLOVIS.......................... 35 61 36 71 / 0 0 0 0 PORTALES........................ 35 63 35 72 / 0 0 0 0 FORT SUMNER..................... 36 64 34 74 / 0 0 0 0 ROSWELL......................... 43 68 36 74 / 0 0 0 0 PICACHO......................... 39 63 35 71 / 0 0 0 0 ELK............................. 40 60 34 65 / 0 0 0 0 && .ABQ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...NMZ103-104-108. FREEZE WARNING FROM 1 AM TO 9 AM MDT SATURDAY FOR THE FOLLOWING ZONES...NMZ518-519-524-530>534. && $$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
122 PM EDT FRI OCT 4 2013 .SYNOPSIS... HIGH PRESSURE WILL HANG ON OVER MUCH OF THE NORTH COUNTRY THROUGH SATURDAY AS A FRONTAL SYSTEM REMAINS SUPPRESSED TO THE SOUTH. CHANCES FOR SHOWERS WILL INCREASE SUNDAY AS A WARM FRONT LIFTS NORTH ACROSS THE AREA. MORE RAIN CAN BE EXPECTED MONDAY AS LOW PRESSURE AND ITS ASSOCIATED COLD FRONT MOVE THROUGH THE REGION. HIGH PRESSURE THEN RETURNS FOR THE REMAINDER OF NEXT WEEK. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 1249 PM EDT FRIDAY...HAVE UPDATED FCST TO MENTION ADDITIONAL SHOWERS/SPRINKLES THIS AFTN...AS CRNT RADAR CONTS TO SHOW MORE SHOWERS MOVING ACRS NORTHERN NY. MOST OF THIS PRECIP IS VERY LIGHT WITH ONLY A COUPLE 0.01 OF AN INCH ANTICIPATED. WEAK EMBEDDED SHORT WAVES RIDING ALONG SEVERAL SFC BOUNDARIES CONTS TO SUPPORT THE MENTION OF POPS THRU THIS AFTN. HOWEVER...EVENTUALLY SFC HIGH PRES LOCATED NEAR HUDSON BAY WL ADVECT DRIER AIR INTO OUR REGION ON NORTHERLY WINDS TO DECREASE THE THREAT FOR LIGHT PRECIP BY THIS EVENING. TEMPS WL RANGE MAINLY IN THE U50S TO M60S...VERY CLOSE TO NORMAL. HAVE INCREASED POPS ACRS OUR SOUTHERN VT ZNS TO LIKELY/LOW CAT (70 TO 80%) AND HIGH CHC (40 TO 50%) FOR PARTS OF THE SLV/WESTERN DACKS FOR THIS MORNING. CRNT RADAR SHOWS A BAND OF LIGHT RAIN ACRS SOUTHERN VT WITH LIGHT RAIN BEING OBSERVED AT VSF. IN ADDITION...ANOTHER BAND OF LIGHT RAIN IS ENTERING THE SLV ATTM. LATEST 12Z RAP 13 SHOWS BEST 850 TO 700MB LIFT ASSOCIATED WITH WAA AND EMBEDDED 5H VORT WL BE ACRS OUR CENTRAL/SOUTHERN CWA THRU 16Z...BEFORE SHIFTING TO OUR EAST. MEANWHILE...PRECIP ACRS SLV IS EXPECTED TO WEAKEN ACRS THE DACKS/WESTERN CPV BY 16Z...AS LLVL ENVIRONMENT IS VERY DRY. OVERALL...NOT EXPECTING MUCH QPF>0.10" THRU TODAY...WITH A GENERAL DECREASE IN AREAL COVERAGE OF PRECIP THIS AFTN. TEMPS WL BE TRICKY AND HIGHLY DEPEND UPON CLOUD CLOUD...WHICH WL PREVAIL MOST OF THE DAY...THEREFORE WL TREND TEMPS DOWN SEVERAL DEGREES. THINKING U50S TO M60S MOST LOCATIONS. PREVIOUS DISCUSSION... WARM FRONT STRETCHING FROM NORTHERN MICHIGAN SOUTHEAST TO JERSEY COASTAL WATERS AT THIS TIME. THIS FRONT WILL NOT ADVANCE MUCH FURTHER NORTH TODAY BEFORE BECOMING STATIONARY. MEANWHILE...WEAK COLD FRONT NORTH OF THE BORDER WILL DISSIPATE AS IT DEPRESSES SOUTH. SKIES STILL MOSTLY CLEAR ACROSS A GOOD PORTION OF FORECAST AREA AT THIS TIME...BUT CLOUDS TO THE WEST WILL OVERSPREAD THE REGION TODAY WITH ANY FOG DISSIPATING BY MID MORNING. SOME SHOWERS AND EVEN A LITTLE EMBEDDED THUNDER NORTH OF THE WARM FRONT AT THIS TIME...BUT MOST OF THIS ACTIVITY IS EXPECTED TO PASS JUST SOUTH OF BTV CWA TODAY. ANY SHOWERS ASSOCIATED WITH COLD FRONT TO THE NORTH SHOULD DISSIPATE. SO BEST CHANCE FOR SEEING A FEW SHOWERS TODAY WILL BE ACROSS SOUTHERN PORTION OF FORECAST AREA...WHERE 20-30 POPS PREFERRED. TEMPERATURES WILL BE A BIT COOLER THAN PREVIOUS DAYS...WITH HIGHS IN THE MID 60S TO AROUND 70. && .SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/... AS OF 441 AM EDT FRIDAY...STATIONARY BOUNDARY WILL REMAIN SOUTH OF THE FORECAST TONIGHT THROUGH SATURDAY NIGHT. FRONT MAY ACTUALLY BE PUSHED FURTHER SOUTH TONIGHT THROUGH SATURDAY AS HIGH PRESSURE ANCHORED OVER HUDSON BAY NOSES SOUTHEAST INTO NEW YORK/NEW ENGLAND WHILE FLOW ALOFT CONTINUES FROM THE WEST-NORTHWEST. ALTHOUGH SKIES ARE EXPECTED TO BE MOSTLY CLOUDY...IT SHOULD ALSO BE MAINLY DRY TONIGHT THROUGH SATURDAY...WITH JUST A SLIGHT CHANCE SHOWERS SOUTH. CONDITIONS BEGIN TO CHANGE LATER SATURDAY NIGHT INTO SUNDAY AS UPPER RIDGE SLOWLY SHIFTS EAST. THIS IS IN RESPONSE TO DEEP UPPER LOW APPROACHING THE WESTERN GREAT LAKES SUNDAY. AS FLOW ALOFT BECOMES MORE SOUTHWESTERLY...THIS WILL ALLOW WARM FRONT TO FINALLY MAKE ITS PUSH NORTHWARD. SURGE OF DEEP MOISTURE...WITH PRECIPITABLE WATER VALUES INCREASING TO 1.50 TO 1.75 INCHES...COMBINED WITH BAND OF FRONTOGENESIS ASSOCIATED WITH WARM FRONT WILL RESULT IN AT LEAST LIKELY POPS FOR LATE SATURDAY NIGHT AND ESPECIALLY DURING THE DAY ON SUNDAY. CAN`T RULE OUT EMBEDDED THUNDER OVER WESTERN ZONES SUNDAY AFTERNOON WITH SOME WEAK INSTABILITY INDICATED. HIGH TEMPERATURES BOTH SATURDAY AND SUNDAY WILL BE MAINLY IN THE MID60S TO NEAR 70...WITH LOWS IN THE 40S TONIGHT AND AROUND 50 SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 352 AM EDT FRIDAY...IT TOOK AWHILE...BUT MEDIUM RANGE GUIDANCE OF THE GFS AND ECMWF HAVE FINALLY COME INTO GOOD AGREEMENT IN REGARDS TO A POTENT LOW PRESSURE SYSTEM MOVING OUT OF THE ROCKIES TODAY WHICH WILL AFFECT THE NORTHEAST THIS WEEKEND INTO EARLY NEXT WEEK. FORECASTER CONFIDENCE IS INCREASING THAT WE`LL SEE A MODEST RAIN EVENT LATE SUNDAY NIGHT THROUGH MONDAY. YOU CAN READ MORE ABOUT THE EVOLUTION OF THIS SYSTEM THROUGH THE WEEKEND IN THE SHORT TERM SECTION ABOVE...BUT THE SYNOPTIC SETUP TO START THE EXTENDED PERIOD SUNDAY NIGHT WILL FEATURE A DEEP CLOSED LOW SHIFTING NORTHEAST INTO THE GREAT LAKES REGION...WHILE AN UPPER TROUGH ACROSS CENTRAL CANADA DIGS SOUTHEASTWARD TOWARDS THE INTERNATIONAL BORDER. THESE TWO FEATURES EVENTUALLY PHASE TOGETHER BY MIDDAY MONDAY WITH THE ATTENDING SURFACE WARM FRONT SHIFTING NORTH OF THE BTV CWA SUNDAY NIGHT...AND THE COLD FRONT SWEEPING THROUGH ON MONDAY. FOR SUNDAY NIGHT...HAVE BACKED OFF POPS A BIT AS STRONG SOUTH/SOUTHWESTERLY FLOW IN THE WARM SECTOR SHOULD KEEP MUCH OF THE AREA DRY...WITH THE EXCEPTION BEING ACROSS THE ST. LAWRENCE VALLEY WHERE SHOWERS WILL BE LIKELY CLOSER TO THE COLD FRONT. ANOMALOUSLY HIGH PWATS FOR OCTOBER BETWEEN 1.50 AND 1.75" ON THE NOSE OF A STRONG 50KT 850MB SOUTHWESTERLY JET WILL ENHANCE DEEP LAYER LIFT ALONG THE COLD FRONT LATE SUNDAY NIGHT THROUGH MONDAY AS IT TRACKS ACROSS THE FORECAST AREA AND THUS...HAVE CONTINUED THE IDEA OF LIKELY POPS FOR THIS TIME RANGE. ALSO ADDING MOISTURE INTO THE MIX WILL BE THE REMNANTS OF TROPICAL STORM KAREN WHICH GETS ABSORBED INTO THE UPPER FLOW DURING THIS TIME AS WELL. LATEST RUNS OF THE GFS AND ECMWF DIFFER ONLY SLIGHTLY ON TIMING OF THE COLD FROPA...WITH THE ECMWF LAGGING SLIGHTLY BEHIND. WITH THE RECENT BETTER CONSISTENCY OF THE GFS AND CONTINUED TO LEAN TOWARDS THAT SOLUTION...WHICH PUSHES THE FRONT EAST OF THE CONNECTICUT RIVER VALLEY BY 00Z TUESDAY AS SURFACE HIGH PRESSURE BEGINS TO BUILD IN FROM THE WEST. PARTLY TO MOSTLY CLOUDY SKIES PERSIST THROUGH MUCH OF TUESDAY ON NORTHWEST UPPER FLOW...BUT BY TUESDAY NIGHT RIDGING ALOFT BUILDS IN AND HIGH PRESSURE SHOULD DOMINATE THE NORTH COUNTRY`S WEATHER THROUGH THE REMAINDER OF THE WEEK. && .AVIATION /17Z FRIDAY THROUGH WEDNESDAY/... THROUGH 18Z SATURDAY...SATELLITE IMAGERY SHOWS QUITE A BIT OF CLOUD COVER MOVING FROM WEST TO EAST ACROSS THE AREA THIS AFTERNOON AND THIS WILL BE THE TREND THROUGH THE REMAINDER OF THE PERIOD WITH MORE CLOUDS UPSTREAM OVER THE EASTERN GREAT LAKES POISED TO MOVE INTO THE AREA AS WELL. HOWEVER...CEILINGS WILL GENERALLY BE AT OR ABOVE 5000 FEET WITH SOME LOWERING OF THE CLOUDS TONIGHT INTO THE 3000-5000 FOOT RANGE. NEVERTHELESS...LOOKING AT VFR CEILINGS THOUGH THE ENTIRE PERIOD. SCATTERED LIGHT RAIN SHOWERS WILL MOVE ACROSS THE AREA THROUGH 00Z TONIGHT...BUT VISIBILITIES WILL REMAIN IN THE VFR CATEGORY. WINDS WILL GENERALLY HAVE A NORTHERLY COMPONENT TO THEM...BUT SPEEDS WILL BE 10 KNOTS OR LESS THROUGH THE PERIOD. OUTLOOK 18Z SATURDAY THROUGH WEDNESDAY... 18Z SATURDAY THROUGH 00Z SUNDAY...MAINLY VFR THOUGH CEILINGS WILL CONTINUE TO LOWER THRU THE PERIOD. SLIGHT CHANCE FOR SHOWERS. 00Z SUNDAY THROUGH 00Z MONDAY...MAINLY VFR WITH INCREASING CHANCES FOR MVFR RAIN SHOWERS AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST...ESPECIALLY ACROSS NORTHERN NEW YORK. 00Z MONDAY THROUGH 00Z TUESDAY...MVFR RAIN SHOWERS LIKELY AS A COLD FRONT MOVES THROUGH THE REGION. 00Z TUESDAY THROUGH 00Z THURSDAY...VFR UNDER HIGH PRESSURE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...RJS NEAR TERM...RJS/TABER SHORT TERM...RJS LONG TERM...LAHIFF AVIATION...EVENSON/LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1254 PM EDT FRI OCT 4 2013 .SYNOPSIS... HIGH PRESSURE WILL HANG ON OVER MUCH OF THE NORTH COUNTRY THROUGH SATURDAY AS A FRONTAL SYSTEM REMAINS SUPPRESSED TO THE SOUTH. CHANCES FOR SHOWERS WILL INCREASE SUNDAY AS A WARM FRONT LIFTS NORTH ACROSS THE AREA. MORE RAIN CAN BE EXPECTED MONDAY AS LOW PRESSURE AND ITS ASSOCIATED COLD FRONT MOVE THROUGH THE REGION. HIGH PRESSURE THEN RETURNS FOR THE REMAINDER OF NEXT WEEK. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 1249 PM EDT FRIDAY...HAVE UPDATED FCST TO MENTION ADDITIONAL SHOWERS/SPRINKLES THIS AFTN...AS CRNT RADAR CONTS TO SHOW MORE SHOWERS MOVING ACRS NORTHERN NY. MOST OF THIS PRECIP IS VERY LIGHT WITH ONLY A COUPLE 0.01 OF AN INCH ANTICIPATED. WEAK EMBEDDED SHORT WAVES RIDING ALONG SEVERAL SFC BOUNDARIES CONTS TO SUPPORT THE MENTION OF POPS THRU THIS AFTN. HOWEVER...EVENTUALLY SFC HIGH PRES LOCATED NEAR HUDSON BAY WL ADVECT DRIER AIR INTO OUR REGION ON NORTHERLY WINDS TO DECREASE THE THREAT FOR LIGHT PRECIP BY THIS EVENING. TEMPS WL RANGE MAINLY IN THE U50S TO M60S...VERY CLOSE TO NORMAL. HAVE INCREASED POPS ACRS OUR SOUTHERN VT ZNS TO LIKELY/LOW CAT (70 TO 80%) AND HIGH CHC (40 TO 50%) FOR PARTS OF THE SLV/WESTERN DACKS FOR THIS MORNING. CRNT RADAR SHOWS A BAND OF LIGHT RAIN ACRS SOUTHERN VT WITH LIGHT RAIN BEING OBSERVED AT VSF. IN ADDITION...ANOTHER BAND OF LIGHT RAIN IS ENTERING THE SLV ATTM. LATEST 12Z RAP 13 SHOWS BEST 850 TO 700MB LIFT ASSOCIATED WITH WAA AND EMBEDDED 5H VORT WL BE ACRS OUR CENTRAL/SOUTHERN CWA THRU 16Z...BEFORE SHIFTING TO OUR EAST. MEANWHILE...PRECIP ACRS SLV IS EXPECTED TO WEAKEN ACRS THE DACKS/WESTERN CPV BY 16Z...AS LLVL ENVIRONMENT IS VERY DRY. OVERALL...NOT EXPECTING MUCH QPF>0.10" THRU TODAY...WITH A GENERAL DECREASE IN AREAL COVERAGE OF PRECIP THIS AFTN. TEMPS WL BE TRICKY AND HIGHLY DEPEND UPON CLOUD CLOUD...WHICH WL PREVAIL MOST OF THE DAY...THEREFORE WL TREND TEMPS DOWN SEVERAL DEGREES. THINKING U50S TO M60S MOST LOCATIONS. PREVIOUS DISCUSSION... WARM FRONT STRETCHING FROM NORTHERN MICHIGAN SOUTHEAST TO JERSEY COASTAL WATERS AT THIS TIME. THIS FRONT WILL NOT ADVANCE MUCH FURTHER NORTH TODAY BEFORE BECOMING STATIONARY. MEANWHILE...WEAK COLD FRONT NORTH OF THE BORDER WILL DISSIPATE AS IT DEPRESSES SOUTH. SKIES STILL MOSTLY CLEAR ACROSS A GOOD PORTION OF FORECAST AREA AT THIS TIME...BUT CLOUDS TO THE WEST WILL OVERSPREAD THE REGION TODAY WITH ANY FOG DISSIPATING BY MID MORNING. SOME SHOWERS AND EVEN A LITTLE EMBEDDED THUNDER NORTH OF THE WARM FRONT AT THIS TIME...BUT MOST OF THIS ACTIVITY IS EXPECTED TO PASS JUST SOUTH OF BTV CWA TODAY. ANY SHOWERS ASSOCIATED WITH COLD FRONT TO THE NORTH SHOULD DISSIPATE. SO BEST CHANCE FOR SEEING A FEW SHOWERS TODAY WILL BE ACROSS SOUTHERN PORTION OF FORECAST AREA...WHERE 20-30 POPS PREFERRED. TEMPERATURES WILL BE A BIT COOLER THAN PREVIOUS DAYS...WITH HIGHS IN THE MID 60S TO AROUND 70. && .SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/... AS OF 441 AM EDT FRIDAY...STATIONARY BOUNDARY WILL REMAIN SOUTH OF THE FORECAST TONIGHT THROUGH SATURDAY NIGHT. FRONT MAY ACTUALLY BE PUSHED FURTHER SOUTH TONIGHT THROUGH SATURDAY AS HIGH PRESSURE ANCHORED OVER HUDSON BAY NOSES SOUTHEAST INTO NEW YORK/NEW ENGLAND WHILE FLOW ALOFT CONTINUES FROM THE WEST-NORTHWEST. ALTHOUGH SKIES ARE EXPECTED TO BE MOSTLY CLOUDY...IT SHOULD ALSO BE MAINLY DRY TONIGHT THROUGH SATURDAY...WITH JUST A SLIGHT CHANCE SHOWERS SOUTH. CONDITIONS BEGIN TO CHANGE LATER SATURDAY NIGHT INTO SUNDAY AS UPPER RIDGE SLOWLY SHIFTS EAST. THIS IS IN RESPONSE TO DEEP UPPER LOW APPROACHING THE WESTERN GREAT LAKES SUNDAY. AS FLOW ALOFT BECOMES MORE SOUTHWESTERLY...THIS WILL ALLOW WARM FRONT TO FINALLY MAKE ITS PUSH NORTHWARD. SURGE OF DEEP MOISTURE...WITH PRECIPITABLE WATER VALUES INCREASING TO 1.50 TO 1.75 INCHES...COMBINED WITH BAND OF FRONTOGENESIS ASSOCIATED WITH WARM FRONT WILL RESULT IN AT LEAST LIKELY POPS FOR LATE SATURDAY NIGHT AND ESPECIALLY DURING THE DAY ON SUNDAY. CAN`T RULE OUT EMBEDDED THUNDER OVER WESTERN ZONES SUNDAY AFTERNOON WITH SOME WEAK INSTABILITY INDICATED. HIGH TEMPERATURES BOTH SATURDAY AND SUNDAY WILL BE MAINLY IN THE MID60S TO NEAR 70...WITH LOWS IN THE 40S TONIGHT AND AROUND 50 SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 352 AM EDT FRIDAY...IT TOOK AWHILE...BUT MEDIUM RANGE GUIDANCE OF THE GFS AND ECMWF HAVE FINALLY COME INTO GOOD AGREEMENT IN REGARDS TO A POTENT LOW PRESSURE SYSTEM MOVING OUT OF THE ROCKIES TODAY WHICH WILL AFFECT THE NORTHEAST THIS WEEKEND INTO EARLY NEXT WEEK. FORECASTER CONFIDENCE IS INCREASING THAT WE`LL SEE A MODEST RAIN EVENT LATE SUNDAY NIGHT THROUGH MONDAY. YOU CAN READ MORE ABOUT THE EVOLUTION OF THIS SYSTEM THROUGH THE WEEKEND IN THE SHORT TERM SECTION ABOVE...BUT THE SYNOPTIC SETUP TO START THE EXTENDED PERIOD SUNDAY NIGHT WILL FEATURE A DEEP CLOSED LOW SHIFTING NORTHEAST INTO THE GREAT LAKES REGION...WHILE AN UPPER TROUGH ACROSS CENTRAL CANADA DIGS SOUTHEASTWARD TOWARDS THE INTERNATIONAL BORDER. THESE TWO FEATURES EVENTUALLY PHASE TOGETHER BY MIDDAY MONDAY WITH THE ATTENDING SURFACE WARM FRONT SHIFTING NORTH OF THE BTV CWA SUNDAY NIGHT...AND THE COLD FRONT SWEEPING THROUGH ON MONDAY. FOR SUNDAY NIGHT...HAVE BACKED OFF POPS A BIT AS STRONG SOUTH/SOUTHWESTERLY FLOW IN THE WARM SECTOR SHOULD KEEP MUCH OF THE AREA DRY...WITH THE EXCEPTION BEING ACROSS THE ST. LAWRENCE VALLEY WHERE SHOWERS WILL BE LIKELY CLOSER TO THE COLD FRONT. ANOMALOUSLY HIGH PWATS FOR OCTOBER BETWEEN 1.50 AND 1.75" ON THE NOSE OF A STRONG 50KT 850MB SOUTHWESTERLY JET WILL ENHANCE DEEP LAYER LIFT ALONG THE COLD FRONT LATE SUNDAY NIGHT THROUGH MONDAY AS IT TRACKS ACROSS THE FORECAST AREA AND THUS...HAVE CONTINUED THE IDEA OF LIKELY POPS FOR THIS TIME RANGE. ALSO ADDING MOISTURE INTO THE MIX WILL BE THE REMNANTS OF TROPICAL STORM KAREN WHICH GETS ABSORBED INTO THE UPPER FLOW DURING THIS TIME AS WELL. LATEST RUNS OF THE GFS AND ECMWF DIFFER ONLY SLIGHTLY ON TIMING OF THE COLD FROPA...WITH THE ECMWF LAGGING SLIGHTLY BEHIND. WITH THE RECENT BETTER CONSISTENCY OF THE GFS AND CONTINUED TO LEAN TOWARDS THAT SOLUTION...WHICH PUSHES THE FRONT EAST OF THE CONNECTICUT RIVER VALLEY BY 00Z TUESDAY AS SURFACE HIGH PRESSURE BEGINS TO BUILD IN FROM THE WEST. PARTLY TO MOSTLY CLOUDY SKIES PERSIST THROUGH MUCH OF TUESDAY ON NORTHWEST UPPER FLOW...BUT BY TUESDAY NIGHT RIDGING ALOFT BUILDS IN AND HIGH PRESSURE SHOULD DOMINATE THE NORTH COUNTRY`S WEATHER THROUGH THE REMAINDER OF THE WEEK. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... THROUGH 12Z SATURDAY...OUTSIDE OF SOME LINGERING FOG AT KSLK AND KMPV THROUGH 14Z...GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH MID CLOUDS FROM 5-10 KFT STREAMING ACROSS THE AREA. COULD SEE A FEW SHOWERS MAINLY ACROSS SOUTHERN VT AND NORTHERN NEW YORK...BUT SHOULDN`T IMPACT FLIGHT CONDITIONS. AFTER 00Z WHEN CIGS LOWER FURTHER TO 4-6 KFT BUT SHOULD REMAIN VFR. WINDS THROUGH THE PERIOD WILL BE LIGHT AND VARIABLE. OUTLOOK 12Z SATURDAY THROUGH TUESDAY... 12Z SATURDAY THROUGH 00Z SUNDAY...MAINLY VFR THOUGH CEILINGS WILL CONTINUE TO LOWER THRU THE PERIOD. SLIGHT CHANCE FOR SHOWERS. 00Z SUNDAY THROUGH 00Z MONDAY...MAINLY VFR WITH INCREASING CHANCES FOR MVFR RAIN SHOWERS AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST...ESPECIALLY ACROSS NORTHERN NEW YORK. 00Z MONDAY THROUGH 00Z TUESDAY...MVFR RAIN SHOWERS LIKELY AS A COLD FRONT MOVES THROUGH THE REGION. 00Z TUESDAY THROUGH 00Z WEDNESDAY...VFR UNDER HIGH PRESSURE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...RJS NEAR TERM...RJS/TABER SHORT TERM...RJS LONG TERM...LAHIFF AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
957 AM EDT FRI OCT 4 2013 .SYNOPSIS... HIGH PRESSURE WILL HANG ON OVER MUCH OF THE NORTH COUNTRY THROUGH SATURDAY AS A FRONTAL SYSTEM REMAINS SUPPRESSED TO THE SOUTH. CHANCES FOR SHOWERS WILL INCREASE SUNDAY AS A WARM FRONT LIFTS NORTH ACROSS THE AREA. MORE RAIN CAN BE EXPECTED MONDAY AS LOW PRESSURE AND ITS ASSOCIATED COLD FRONT MOVE THROUGH THE REGION. HIGH PRESSURE THEN RETURNS FOR THE REMAINDER OF NEXT WEEK. && .NEAR TERM /UNTIL 8 PM THIS EVENING/... AS OF 949 AM EDT FRIDAY...HAVE INCREASED POPS ACRS OUR SOUTHERN VT ZNS TO LIKELY/LOW CAT (70 TO 80%) AND HIGH CHC (40 TO 50%) FOR PARTS OF THE SLV/WESTERN DACKS FOR THIS MORNING. CRNT RADAR SHOWS A BAND OF LIGHT RAIN ACRS SOUTHERN VT WITH LIGHT RAIN BEING OBSERVED AT VSF. IN ADDITION...ANOTHER BAND OF LIGHT RAIN IS ENTERING THE SLV ATTM. LATEST 12Z RAP 13 SHOWS BEST 850 TO 700MB LIFT ASSOCIATED WITH WAA AND EMBEDDED 5H VORT WL BE ACRS OUR CENTRAL/SOUTHERN CWA THRU 16Z...BEFORE SHIFTING TO OUR EAST. MEANWHILE...PRECIP ACRS SLV IS EXPECTED TO WEAKEN ACRS THE DACKS/WESTERN CPV BY 16Z...AS LLVL ENVIRONMENT IS VERY DRY. OVERALL...NOT EXPECTING MUCH QPF>0.10" THRU TODAY...WITH A GENERAL DECREASE IN AREAL COVERAGE OF PRECIP THIS AFTN. TEMPS WL BE TRICKY AND HIGHLY DEPEND UPON CLOUD CLOUD...WHICH WL PREVAIL MOST OF THE DAY...THEREFORE WL TREND TEMPS DOWN SEVERAL DEGREES. THINKING U50S TO M60S MOST LOCATIONS. PREVIOUS DISCUSSION... WARM FRONT STRETCHING FROM NORTHERN MICHIGAN SOUTHEAST TO JERSEY COASTAL WATERS AT THIS TIME. THIS FRONT WILL NOT ADVANCE MUCH FURTHER NORTH TODAY BEFORE BECOMING STATIONARY. MEANWHILE...WEAK COLD FRONT NORTH OF THE BORDER WILL DISSIPATE AS IT DEPRESSES SOUTH. SKIES STILL MOSTLY CLEAR ACROSS A GOOD PORTION OF FORECAST AREA AT THIS TIME...BUT CLOUDS TO THE WEST WILL OVERSPREAD THE REGION TODAY WITH ANY FOG DISSIPATING BY MID MORNING. SOME SHOWERS AND EVEN A LITTLE EMBEDDED THUNDER NORTH OF THE WARM FRONT AT THIS TIME...BUT MOST OF THIS ACTIVITY IS EXPECTED TO PASS JUST SOUTH OF BTV CWA TODAY. ANY SHOWERS ASSOCIATED WITH COLD FRONT TO THE NORTH SHOULD DISSIPATE. SO BEST CHANCE FOR SEEING A FEW SHOWERS TODAY WILL BE ACROSS SOUTHERN PORTION OF FORECAST AREA...WHERE 20-30 POPS PREFERRED. TEMPERATURES WILL BE A BIT COOLER THAN PREVIOUS DAYS...WITH HIGHS IN THE MID 60S TO AROUND 70. && .SHORT TERM /8 PM THIS EVENING THROUGH SATURDAY NIGHT/... AS OF 441 AM EDT FRIDAY...STATIONARY BOUNDARY WILL REMAIN SOUTH OF THE FORECAST TONIGHT THROUGH SATURDAY NIGHT. FRONT MAY ACTUALLY BE PUSHED FURTHER SOUTH TONIGHT THROUGH SATURDAY AS HIGH PRESSURE ANCHORED OVER HUDSON BAY NOSES SOUTHEAST INTO NEW YORK/NEW ENGLAND WHILE FLOW ALOFT CONTINUES FROM THE WEST-NORTHWEST. ALTHOUGH SKIES ARE EXPECTED TO BE MOSTLY CLOUDY...IT SHOULD ALSO BE MAINLY DRY TONIGHT THROUGH SATURDAY...WITH JUST A SLIGHT CHANCE SHOWERS SOUTH. CONDITIONS BEGIN TO CHANGE LATER SATURDAY NIGHT INTO SUNDAY AS UPPER RIDGE SLOWLY SHIFTS EAST. THIS IS IN RESPONSE TO DEEP UPPER LOW APPROACHING THE WESTERN GREAT LAKES SUNDAY. AS FLOW ALOFT BECOMES MORE SOUTHWESTERLY...THIS WILL ALLOW WARM FRONT TO FINALLY MAKE ITS PUSH NORTHWARD. SURGE OF DEEP MOISTURE...WITH PRECIPITABLE WATER VALUES INCREASING TO 1.50 TO 1.75 INCHES...COMBINED WITH BAND OF FRONTOGENESIS ASSOCIATED WITH WARM FRONT WILL RESULT IN AT LEAST LIKELY POPS FOR LATE SATURDAY NIGHT AND ESPECIALLY DURING THE DAY ON SUNDAY. CAN`T RULE OUT EMBEDDED THUNDER OVER WESTERN ZONES SUNDAY AFTERNOON WITH SOME WEAK INSTABILITY INDICATED. HIGH TEMPERATURES BOTH SATURDAY AND SUNDAY WILL BE MAINLY IN THE MID60S TO NEAR 70...WITH LOWS IN THE 40S TONIGHT AND AROUND 50 SATURDAY NIGHT. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 352 AM EDT FRIDAY...IT TOOK AWHILE...BUT MEDIUM RANGE GUIDANCE OF THE GFS AND ECMWF HAVE FINALLY COME INTO GOOD AGREEMENT IN REGARDS TO A POTENT LOW PRESSURE SYSTEM MOVING OUT OF THE ROCKIES TODAY WHICH WILL AFFECT THE NORTHEAST THIS WEEKEND INTO EARLY NEXT WEEK. FORECASTER CONFIDENCE IS INCREASING THAT WE`LL SEE A MODEST RAIN EVENT LATE SUNDAY NIGHT THROUGH MONDAY. YOU CAN READ MORE ABOUT THE EVOLUTION OF THIS SYSTEM THROUGH THE WEEKEND IN THE SHORT TERM SECTION ABOVE...BUT THE SYNOPTIC SETUP TO START THE EXTENDED PERIOD SUNDAY NIGHT WILL FEATURE A DEEP CLOSED LOW SHIFTING NORTHEAST INTO THE GREAT LAKES REGION...WHILE AN UPPER TROUGH ACROSS CENTRAL CANADA DIGS SOUTHEASTWARD TOWARDS THE INTERNATIONAL BORDER. THESE TWO FEATURES EVENTUALLY PHASE TOGETHER BY MIDDAY MONDAY WITH THE ATTENDING SURFACE WARM FRONT SHIFTING NORTH OF THE BTV CWA SUNDAY NIGHT...AND THE COLD FRONT SWEEPING THROUGH ON MONDAY. FOR SUNDAY NIGHT...HAVE BACKED OFF POPS A BIT AS STRONG SOUTH/SOUTHWESTERLY FLOW IN THE WARM SECTOR SHOULD KEEP MUCH OF THE AREA DRY...WITH THE EXCEPTION BEING ACROSS THE ST. LAWRENCE VALLEY WHERE SHOWERS WILL BE LIKELY CLOSER TO THE COLD FRONT. ANOMALOUSLY HIGH PWATS FOR OCTOBER BETWEEN 1.50 AND 1.75" ON THE NOSE OF A STRONG 50KT 850MB SOUTHWESTERLY JET WILL ENHANCE DEEP LAYER LIFT ALONG THE COLD FRONT LATE SUNDAY NIGHT THROUGH MONDAY AS IT TRACKS ACROSS THE FORECAST AREA AND THUS...HAVE CONTINUED THE IDEA OF LIKELY POPS FOR THIS TIME RANGE. ALSO ADDING MOISTURE INTO THE MIX WILL BE THE REMNANTS OF TROPICAL STORM KAREN WHICH GETS ABSORBED INTO THE UPPER FLOW DURING THIS TIME AS WELL. LATEST RUNS OF THE GFS AND ECMWF DIFFER ONLY SLIGHTLY ON TIMING OF THE COLD FROPA...WITH THE ECMWF LAGGING SLIGHTLY BEHIND. WITH THE RECENT BETTER CONSISTENCY OF THE GFS AND CONTINUED TO LEAN TOWARDS THAT SOLUTION...WHICH PUSHES THE FRONT EAST OF THE CONNECTICUT RIVER VALLEY BY 00Z TUESDAY AS SURFACE HIGH PRESSURE BEGINS TO BUILD IN FROM THE WEST. PARTLY TO MOSTLY CLOUDY SKIES PERSIST THROUGH MUCH OF TUESDAY ON NORTHWEST UPPER FLOW...BUT BY TUESDAY NIGHT RIDGING ALOFT BUILDS IN AND HIGH PRESSURE SHOULD DOMINATE THE NORTH COUNTRY`S WEATHER THROUGH THE REMAINDER OF THE WEEK. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... THROUGH 12Z SATURDAY...OUTSIDE OF SOME LINGERING FOG AT KSLK AND KMPV THROUGH 14Z...GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH MID CLOUDS FROM 5-10 KFT STREAMING ACROSS THE AREA. COULD SEE A FEW SHOWERS MAINLY ACROSS SOUTHERN VT AND NORTHERN NEW YORK...BUT SHOULDN`T IMPACT FLIGHT CONDITIONS. AFTER 00Z WHEN CIGS LOWER FURTHER TO 4-6 KFT BUT SHOULD REMAIN VFR. WINDS THROUGH THE PERIOD WILL BE LIGHT AND VARIABLE. OUTLOOK 12Z SATURDAY THROUGH TUESDAY... 12Z SATURDAY THROUGH 00Z SUNDAY...MAINLY VFR THOUGH CEILINGS WILL CONTINUE TO LOWER THRU THE PERIOD. SLIGHT CHANCE FOR SHOWERS. 00Z SUNDAY THROUGH 00Z MONDAY...MAINLY VFR WITH INCREASING CHANCES FOR MVFR RAIN SHOWERS AS A LOW PRESSURE SYSTEM APPROACHES FROM THE WEST...ESPECIALLY ACROSS NORTHERN NEW YORK. 00Z MONDAY THROUGH 00Z TUESDAY...MVFR RAIN SHOWERS LIKELY AS A COLD FRONT MOVES THROUGH THE REGION. 00Z TUESDAY THROUGH 00Z WEDNESDAY...VFR UNDER HIGH PRESSURE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS...RJS NEAR TERM...RJS/TABER SHORT TERM...RJS LONG TERM...LAHIFF AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
854 PM EDT SAT OCT 5 2013 .SYNOPSIS... HIGH PRESSURE OVER THE REGION WILL MOVE SLOWLY EAST AND OFF SHORE OF THE CAROLINA COAST TONIGHT AND SUNDAY. WEAK LOW PRESSURE...AND MOISTURE STREAMING AWAY FROM KAREN...WILL MOVE NORTHEAST ALONG A COLD FRONT THAT WILL CROSS THE CAROLINAS ON MONDAY. && .NEAR TERM /TONIGHT/... AS OF 850 PM SATURDAY... OBSERVATIONAL DATA TRENDS PROVIDE LITTLE REASON TO STRAY FROM PERSISTENCE...FROM BOTH THE PREVIOUS FORECAST AND PREVIOUS NIGHT. 00Z/6TH UPPER AIR DATA REVEALS A DEEP LAYER ANTICYCLONE SITUATED DIRECTLY OVER THE CAROLINAS THIS EVENING...WITH AN ACCOMPANYING BERMUDA RIDGE AXIS AND FLAT PRESSURE GRADIENT AT THE SURFACE. THE VISIBILITY FORECAST FROM THE PAST SEVERAL RUNS OF THE HRRR ALL STRONGLY SUPPORT THE IDEA OF AREAS OF FOG BECOMING LOCALLY DENSE...MAINLY INVOF AND EAST OF US HWY 1. LOWS AGAIN MOSTLY IN THE LOWER 60S. && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... AS OF 255 PM SATURDAY... PRECIPITABLE WATER VALUES HOLD IN THE NORMAL RANGE...AROUND AN INCH TO 1.25 INCHES...THROUGH THE DAY SUNDAY. 850MB THETA-E STARTS TO INCREASE LATE IN THE DAY ESPECIALLY OVER THE FAR WESTERN PIEDMONT...BUT K INDICES REMAIN RELATIVELY LOW IN THE TEENS... INDICATIVE OF DRY MID-LEVEL AIR. BUFR SOUNDINGS SHOW A GOOD CAP PERSISTS AROUND 600MB THROUGH THE DAY SUNDAY...AND ALTHOUGH THE GFS QPF HAS MARGINAL VALUES TOWARD KFAY AND KCTZ LATE SUNDAY AFTERNOON...LIKELY ALONG THE SEA BREEZE...THE SREF AND NAM ARE DRY...THE GFS BUFR SOUNDINGS REMAIN CAPPED...AND MAV MOS GUIDANCE POPS ARE IN SINGLE FIGURES. WILL CONTINUE A DRY FORECAST FOR THE DAY SUNDAY. 850MB MOISTURE OVERALL IS GREATER ON BOTH THE NAM AND GFS BUFR SOUNDINGS SUNDAY COMPARED TO TODAY...WHICH SHOULD RESULT IN AT LEAST GREATER COVERAGE OF CU...HOLDING TEMPERATURES A LITTLE LOWER DESPITE A MORE NOTICEABLE SOUTHERLY BREEZE...AVERAGING AT OR JUST UNDER 10MPH AFTER MIXING. 1000-850MB THICKNESSES SUPPORT TEMPERATURES NEAR THE MOS GUIDANCE...CONSISTENT AMONG THE MAV AND MET IN THE MID TO UPPER 80S. SUNDAY NIGHT...FAIRLY RAPID MOISTENING TAKES PLACE MAINLY AFTER MIDNIGHT AS A 50KT 500MB JET APPROACHES TO OUR NORTHWEST LATE SUNDAY NIGHT...AND A LOW-LEVEL JET WITH WINDS AROUND 35KT AT 850MB AND 30KT AT 925MB MOVES EAST TOWARD...OR INTO...THE WESTERN PIEDMONT BY SUNRISE MONDAY. THE GFS IS FASTER THAN THE NAM...WITH THE FORMER CERTAINLY FARTHER EAST WITH THE LOW-LEVEL JET AND INCREASE IN 850MB THETA-E BY 12Z MONDAY. BOTH THE NAM AND THE GFS SUPPORT AT LEAST A MODEST MID-LEVEL SHORTWAVE MOVING ACROSS THE WESTERN PIEDMONT LATE AT NIGHT...WITH INCREASING LIFT ALONG AND AHEAD OF THE WAVE AND THE INCREASING WINDS ALOFT. IN DEFERENCE TO THE NAM...WILL REFRAIN FROM CATEGORICAL CHANCES OF PRECIPITATION FOR NOW...WHILE FORECASTING HIGH LIKELY POPS TOWARD THE TRIAD AND THE YADKIN RIVER LATE SUNDAY NIGHT...AND INCREASING SIMPLE CHANCE FARTHER EAST PARTICULARLY TOWARD U.S. 1. BUFR SOUNDINGS SHOW CHANCES FOR THUNDER SHOULD BE SOMEWHAT REMOTE UNTIL POSSIBLY VERY LATE SUNDAY NIGHT...AS 0-3KM SHEAR INCREASES TO 25 TO 30KT. 0-3KM HELICITY REMAINS JUST UNDER 100M2/S2 LATE ESPECIALLY ON THE GFS...THOUGH THERE IS SOME CONCERN CURRENTLY FOR LATE NIGHT ROTATING SHOWERS AS THE SHEAR AND MOISTURE INCREASE...AND AS THERE DEVELOPS BETTER LOW-LEVEL TURNING OF THE WINDS LATE. WILL CONTINUE TO MONITOR LATER GUIDANCE RUNS REGARDING THIS. CLOUDS INCREASE OVERNIGHT...AND WINDS MAINTAIN THEMSELVES... LEADING TO MUCH WARMER OVERNIGHT LOWS MAINLY IN THE MID TO UPPER 60S. && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 255 PM SATURDAY... MONDAY AND MONDAY NIGHT...TROPICAL STORM KAREN...CURRENTLY LOCATED IN THE NORTHERN GULF OF MEXICO CONTINUES TO WEAKEN AS IT IS SHEARED APART BY STRONGER WINDS ALOFT. WHAT THIS MEANS FOR OUR REGION...IS IT NOW APPEARS THAT THE STRONG UPPER LEVEL TROUGH (CURRENTLY SITUATED ACROSS THE MIDWEST) WILL BE THE DOMINATE WEATHER FEATURE AT THE START OF THE LONG TERM PERIOD AS THE REMNANTS OF KAREN REMAIN SHUNTED TO OUR SOUTH. THIS TROUGH AND ASSOCIATED SURFACE FRONT ARE EXPECTED TO IMPACT THE AREA MONDAY/MONDAY NIGHT...WITH THE FRONT MOVING EAST OF THE AREA BY TUESDAY MORNING. GULF MOISTURE IS PROGGED TO STREAM UP INTO THE REGION AHEAD OF THE APPROACHING SYSTEM...WITH PWAT VALUES POSSIBLY REACHING CLOSE TO 2 INCHES...WHICH IS SIGNIFICANTLY ABOVE NORMAL (BY 200+ PERCENT). THEREFORE...AM STILL EXPECTING THIS TO BE A GOOD RAIN EVENT AS WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS MOVE ACROSS THE AREA...WITH QPF AMOUNTS GENERALLY BETWEEN 1-1.5 INCHES. HOWEVER...SINCE WE HAVE NOT RECEIVED ANY SIGNIFICANT RAINFALL DURING THE PAST COUPLE OF WEEKS...AM NOT EXPECTING TOO MUCH OF A FLOODING THREAT. EVEN THOUGH THE BEST UPPER LEVEL DYNAMICS ARE PROGGED TO PASS NORTH OF THE AREA...SOME POCKETS OF MARGINAL INSTABILITY COULD COMBINE WITH THE INCREASED SHEAR AND RESULT IN A LOW END SEVERE WEATHER THREAT...WHICH WILL CONTINUE TO BE HIGHLIGHTED IN THE HWO. TUESDAY THROUGH SATURDAY...THERE IS STILL SOME UNCERTAINTY WITH RESPECT TO THE UPPER LEVEL PATTERN FOR THIS TIME FRAME AS SOME RESIDUAL TROUGHING (BUT TO WHAT DEGREE IS IN QUESTION) WILL REMAIN OVER THE SOUTHEAST. REGARDLESS...THE LOW LEVELS ARE GOING TO DRY OUT SIGNIFICANTLY BEHIND THE DEPARTING FRONT AS HIGH PRESSURE BUILDS OVER THE REGION AND THEN REMAINS IN PLACE FOR THE REST OF THE PERIOD. THIS WILL LEAD A RETURN TO DRY AND MORE SEASONABLE TEMPS (GENERALLY MID 70S FOR HIGHS AND LOWER 50S FOR OVERNIGHT LOWS). HOWEVER...IT SHOULD BE NOTED THAT SOME MODEL GUIDANCE (PRIMARILY THE ECMWF) INDICATES A LOW FORMATION ALONG THE OLD FRONT OFF THE COAST AND TRACKS IT NORTHEASTWARD...WHICH WOULD POSSIBLY LEAD TO SOME PRECIP OVER OUR AREA. THIS WILL CONTINUE TO BE MONITORED...BUT FOR NOW WILL MAINTAIN A DRY FORECAST. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 657 PM SATURDAY... PERSISTENCE FORECAST WITH VFR CONDITIONS GIVING WAY TO AREAS OF FOG LATE TONIGHT BETWEEN 06 TO 12Z....WITH HIGHEST PROBABILITIES AND CORRESPONDINGLY LOWER VISIBILITIES EXPECTED IN THE EAST AT KRWI AND KFAY. VFR CONDITIONS SHOULD RETURN BY 14 TO 15Z WITH TIGHTENING PRESSURE GRADIENT IN RESPONSE TO THE APPROACHING COLD FRONT FROM THE WEST PROVIDING A GOOD 7 TO 10KT SOUTHERLY BREEZY SUNDAY AFTERNOON. BEYOND THE 24 HOUR TAF PERIOD...STRENGTHENING SOUTHERLY MOISTURE TRANSPORT IN ADVANCE OF A COLD FRONT APPROACHING FROM THE WEST WILL RESULTING IN DETERIORATING AVIATION CONDITIONS LATE SUNDAY NIGHT/MONDAY MORNING WITH LOW CLOUDS AND SHOWERS DEVELOPING OVER THE THE AREA...WITH BEST COVERAGE AND CORRESPONDING LOWER RESTRICTIONS IN THE WEST. A BAND OF SHOWERS AND POSSIBLY STORMS ARE THEN EXPECTED TO CROSS THE AREA MONDAY AFTERNOON/EVENING. VFR CONDITIONS ARE LIKELY TO RETURN BY TUESDAY AND SHOULD CONTINUE THROUGH THURSDAY...WITH ONLY A SMALL PROBABILITY OF LOW CLOUDS IN A LOW-LEVEL NORTHEAST FLOW LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SEC/DJF NEAR TERM...MWS SHORT TERM...DJF LONG TERM...KRR AVIATION...CBL/DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
156 PM EDT FRI OCT 4 2013 .SYNOPSIS... HIGH PRESSURE CONTINUES TO AFFECT THE WEATHER OF THE REGION THROUGH THE DAY SUNDAY. INCREASING MOISTURE AHEAD OF BOTH A COLD FRONT...AND TROPICAL STORM KAREN...SPREADS INTO THE REGION FOR THE START OF THE NEXT WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1007 AM FRIDAY... WATER VAPOR IMAGERY SHOWED A MODEST MID-LEVEL SHORTWAVE MOVING ACROSS CENTRAL NORTH CAROLINA BUT WITH DRY AIR ALOFT. AT THE SURFACE...THE PIEDMONT TROUGH IS IN PLACE...WITH DEW POINTS IN THE 60S. DESPITE THE AVAILABLE LOW-LEVEL MOISTURE AND MOISTURE AT 850MB ON THE 12Z UPPER-AIR ANALYSIS...DRY AIR ALOFT AND CAPPING SHOULD PRECLUDE DEEP CONVECTION. THE AMDAR SOUNDINGS EARLY THIS MORNING AT BOTH GSO AND RDU COMPARED VERY WELL WITH THE RAP FORECAST SOUNDINGS AT THE SAME TIME...SHOWING SOME COOLING THAT TOOK PLACE ALOFT AROUND 700MB BUT STILL WITH ENOUGH OF A CAP...AND VERY MODEST WARMING BEHIND THE MID-LEVEL SHORTWAVE FORECAST THIS AFTERNOON...THAT THE CHANCES FOR ANY SHOWERS APPEAR PRETTY REMOTE. ALTHOUGH NAM MOS GUIDANCE HAS LOW 20S CHANCES FOR SHOWERS AT KGSO AND KTDF...ALL OTHER GUIDANCE IS DRY...AND THE LATEST HRRR WRF IS DRY AS WELL. COULD BE A FEW CLOUDS DRIFTING IN FROM THE WEST AND NORTHWEST DUE TO SOME DEEPER CONVECTION IN DIRECT VICINITY OF THE HIGHER ELEVATIONS LATE IN THE DAY...BUT OTHERWISE...CONSIDERABLE SUNSHINE EXPECTED THIS AFTERNOON UNDER 700MB SUBSIDENCE. MLCAPE BARELY REGISTERS... WITH A MODIFIED KGSO SOUNDING SHOWING AN MLCAPE IN LOW DOUBLE FIGURES. HIGH TEMPERATURES WILL REMAIN IN THE MID TO UPPER 80S...IN CONJUNCTION WITH 1000-850MB THICKNESSES WHICH COINCIDE WELL WITH MOS GUIDANCE HIGHS...ALONG WITH PERSISTENCE FROM THURSDAY. -DJF TONIGHT...LOW LEVEL SLY FLOW WILL ADVECT MOISTURE INTO THE REGION. THIS WILL BE EVIDENT IN SFC DEWPOINTS NEAR 60-LOWER 60S. WITH MAINLY CLEAR SKIES ALOFT AND A LIGHT-NEAR CALM WIND REGIME...MAY SEE AREAS OF FOG DEVELOP WELL AFTER MIDNIGHT. MIN TEMPS UPPER 50S TO LOWER 60S. -WSS && .SHORT TERM /SATURDAY THROUGH SUNDAY/... AS OF 314 AM FRIDAY... SATURDAY...MID-UPPER LEVEL RIDGE OVER THE SE U.S. AND A SFC HIGH ANCHORED OFFSHORE WILL RESULT IN ANOTHER MOSTLY SUNNY AND WARM DAY. THICKNESSES STEADY IN THE 1410-1415M SO EXPECT SIMILAR HIGHS TEMPS COMPARED TO TODAY....MID-UPPER 80S (POSSIBLY 90 IN THE SANDHILLS). WITH SFC DEWPOINTS IN THE LOWER 60S...IT WILL START FEEL A BIT UNCOMFORTABLE TO MOST FOLKS. BY SATURDAY NIGHT...T.C. KAREN WILL BE LURKING OFF THE NORTHERN GULF OF MEXICO COAST. MEANWHILE A DEEP UPPER LEVEL LOW WILL BE OVER THE CENTRAL PLAINS. THESE WEATHER FEATURES WILL SERVE TO WEAKEN THE UPPER LEVEL RIDGE OVER THE SE U.S. THIS PROCESS WILL ALLOW LOW AND UPPER LEVEL MOISTURE TO INCREASE ACROSS CENTRAL NC SATURDAY NIGHT INTO SUNDAY. WITH SFC DEWPOINTS SOLIDLY IN THE LOWER 60S AND SKIES MOSTLY CLEAR TO START...AREAS OF FOG SHOULD DEVELOP ONCE AGAIN. MIN TEMPS MAINLY NEAR 60-LOWER 60S. SUNDAY...EXPECT TO SEE AN INCREASE IN CLOUDINESS AS MID-UPPER LEVEL WINDS BACK IN RESPONSE TO THE EWD ADVANCING UPPER LEVEL LOW MOVING INTO THE WESTERN GREAT LAKES. THIS WEATHER SYSTEM WILL ALSO CAUSE T.C. KAREN TO LIFT NEWD INTO THE SE U.S. LATE SUNDAY-SUNDAY NIGHT. THE AIR MASS OVER CENTRAL NC WILL QUICKLY BECOME MOISTURE LADEN...ESPECIALLY IN THE WEST. INCREASING DIVERGENCE ALOFT COUPLED WITH WEAK ISENTROPIC UPGLIDE WILL SUPPORT THE DEVELOPMENT OF A FEW SHOWERS LATE IN THE DAY...MAINLY OVER THE SW THIRD OF THE FORECAST AREA. EXTENT/THICKNESS OF CLOUD COVER BY SUNDAY AFTERNOON WILL PLAY A ROLE IN AFTERNOON TEMPS. BELIEVE THAT THERE WILL BE ENOUGH PARTIAL SUN SUNDAY AFTERNOON TO WARM TEMPS BACK INTO THE MID 80S OVER MOST OF THE REGION. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 235 AM FRIDAY... ...KAREN`S REMNANTS WILL AFFECT NC SUNDAY NIGHT THROUGH TUESDAY MORNING... MODEL SOLUTIONS CONCERNING FINER DETAILS OF THE TRACK OF TROPICAL CYCLONE KAREN AND ITS INTERACTION WITH AN APPROACHING COLD FRONT ARE STILL ON THE LOWER END OF THE CONFIDENCE SCALE. ON THE OTHER HAND...WHILE IT IS TOO EARLY TO PINPOINT A NARROW TIME WINDOW OF HEAVY RAIN...A SIGNIFICANT AND WIDESPREAD BENEFICIAL RAIN EVENT APPEARS LIKELY AS THE TROPICAL MOISTURE PLUME FROM KAREN SPREADS INTO THE WEST SUNDAY AFTERNOON/EVENING...AND OVER MOST OF CENTRAL NORTH CAROLINA BY MONDAY MORNING. WIDESPREAD RAINFALL AMOUNTS OF >1 INCH ARE A GOOD BET...AND A STRIPE OF 2+ INCHES CAN REASONABLY BE EXPECTED ALONG AND WEST OF THE EVENTUAL TRACK...WHICH IS NOT CERTAIN AT THIS POINT BUT HAS A GOOD CHANCE OF BEING OVER OR JUST SKIRTING THE CWFA. THE POTENTIAL FOR VERY HEAVY SHOWERS WITH HIGH RAINFALL RATES AND TRAINING CELLS WOULD PRODUCE A THREAT FOR FLASH FLOODING...WHICH WOULD BE MORE LIKELY IN MORE URBANIZED AREAS. CHANGES TO THE FORECAST AT THIS POINT ARE TO INCREASE POPS LATER SUNDAY NIGHT AND MONDAY...WITH A NUDGE UPWARDS IN THE AMOUNTS AS WELL. WILL CONTINUE PROGRESSIVE TAPERING OFF OF THE PRECIP MONDAY NIGHT...WITH LINGERING SHOWERS IN THE NORTHEAST ON TUESDAY. HIGH TEMPS ON MONDAY AND TUESDAY WILL BE IN THE 70S...PERHAPS SOME NEAR 80 READINGS IN THE EAST MONDAY IF PRECIP SPREADS IN A LITTLE SLOWER. MODEL DIVERGENCE IS MORE EVIDENT AS TO LATER DEVELOPMENTS DUE TO DIFFERENCES IN THE EVOLUTION OF A MID-LATE WEEK CUTOFF LOW AND A REX-ISH BLOCKING PATTERN. THE ECMWF AND GFS TAKE DIFFERING ROUTES TO ARRIVE AT A RATHER SIMILAR LOOKING PATTERN. ECMWF DEVELOPS THE CUTOFF TO THE WEST AND MEANDERS IT NORTHEAST AND NEARLY OVERHEAD... WHILE THE GFS DEVELOPS THE CUTOFF OVER NORTHEAST NC AND RETROGRADES IT WEST AND OVERHEAD. AT THIS EARLY JUNCTURE WILL HOLD OFF MAKING ANY CHANGES TO THE ONGOING DRY AND SLIGHTLY BELOW SEASONABLE FORECAST BEYOND TUESDAY AS WE AWAIT LATER MODEL CONSENSUS. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... AS OF 155 PM FRIDAY... VFR CONDITIONS CONTINUE INTO THE OVERNIGHT HOURS. LATE TONIGHT... SOME AREAS OF FOG ARE ANTICIPATED...WITH THE HIGHEST PROBABILITY... AND CORRESPONDINGLY THE LOWER EXPECTED VISIBILITIES...TOWARD KRWI AND KFAY. SREF MODEL PROBABILITIES OF VISIBILITIES BELOW 3 MILES ARE HIGHEST TOWARD THOSE TAF SITES LATE TONIGHT INTO EARLY SATURDAY. SURFACE WINDS WERE FORECAST MAINLY WITH A GENERAL SOUTH OR SOUTHWEST DIRECTION...BUT WITH HIGH PRESSURE DIRECTLY OVERHEAD...THERE IS THE POTENTIAL OF A MORE VARIABLE DIRECTION ESPECIALLY EARLY SATURDAY... WITH THE NAM MODEL SUGGESTIVE OF A BRIEF PERIOD OF LIGHT NORTHEAST WIND BEFORE 15Z SATURDAY. BEYOND THE 18Z VALID TAF PERIOD...ONE AVIATION IMPACT IS AREAS OF FOG AND LOW CLOUDS...WITH GUIDANCE STRONGLY HINTING AT THIS THROUGHOUT CENTRAL NORTH CAROLINA LATE SATURDAY NIGHT AND SUNDAY MORNING. DEPENDING ON THE AMOUNT OF CLOUD COVER IN ADVANCE OF INCREASING MOISTURE AHEAD OF AN APPROACHING COLD FRONT AND THE INFLUENCE OF KAREN...SUB-VFR CONDITIONS ARE POSSIBLE AGAIN LATE SUNDAY NIGHT AND MONDAY MORNING. IN ADDITION...RAIN CHANCES INCREASE INTO MONDAY...CONTINUING INTO TUESDAY...WITH CORRESPONDING AREAS OF SUB-VFR CONDITIONS WHICH SHOULD BE NUMEROUS. WIDESPREAD VFR CONDITIONS ARE LIKELY TO RETURN BY WEDNESDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...DJF/WSS SHORT TERM...WSS LONG TERM...MLM AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1007 AM EDT FRI OCT 4 2013 .SYNOPSIS... HIGH PRESSURE WILL REMAIN ANCHORED OVER THE REGION THROUGH SATURDAY. A COLD FRONT WILL APPROACH FROM THE WEST ON SUNDAY. THE FRONT COMBINED WITH THE REMNANTS OF TROPICAL STORM KAREN ARE EXPECTED TO AFFECT CENTRAL NORTH CAROLINA LATE SUNDAY THROUGH EARLY TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1007 AM FRIDAY... WATER VAPOR IMAGERY SHOWED A MODEST MID-LEVEL SHORTWAVE MOVING ACROSS CENTRAL NORTH CAROLINA BUT WITH DRY AIR ALOFT. AT THE SURFACE...THE PIEDMONT TROUGH IS IN PLACE...WITH DEW POINTS IN THE 60S. DESPITE THE AVAILABLE LOW-LEVEL MOISTURE AND MOISTURE AT 850MB ON THE 12Z UPPER-AIR ANALYSIS...DRY AIR ALOFT AND CAPPING SHOULD PRECLUDE DEEP CONVECTION. THE AMDAR SOUNDINGS EARLY THIS MORNING AT BOTH GSO AND RDU COMPARED VERY WELL WITH THE RAP FORECAST SOUNDINGS AT THE SAME TIME...SHOWING SOME COOLING THAT TOOK PLACE ALOFT AROUND 700MB BUT STILL WITH ENOUGH OF A CAP...AND VERY MODEST WARMING BEHIND THE MID-LEVEL SHORTWAVE FORECAST THIS AFTERNOON...THAT THE CHANCES FOR ANY SHOWERS APPEAR PRETTY REMOTE. ALTHOUGH NAM MOS GUIDANCE HAS LOW 20S CHANCES FOR SHOWERS AT KGSO AND KTDF...ALL OTHER GUIDANCE IS DRY...AND THE LATEST HRRR WRF IS DRY AS WELL. COULD BE A FEW CLOUDS DRIFTING IN FROM THE WEST AND NORTHWEST DUE TO SOME DEEPER CONVECTION IN DIRECT VICINITY OF THE HIGHER ELEVATIONS LATE IN THE DAY...BUT OTHERWISE...CONSIDERABLE SUNSHINE EXPECTED THIS AFTERNOON UNDER 700MB SUBSIDENCE. MLCAPE BARELY REGISTERS... WITH A MODIFIED KGSO SOUNDING SHOWING AN MLCAPE IN LOW DOUBLE FIGURES. HIGH TEMPERATURES WILL REMAIN IN THE MID TO UPPER 80S...IN CONJUNCTION WITH 1000-850MB THICKNESSES WHICH COINCIDE WELL WITH MOS GUIDANCE HIGHS...ALONG WITH PERSISTENCE FROM THURSDAY. -DJF TONIGHT...LOW LEVEL SLY FLOW WILL ADVECT MOISTURE INTO THE REGION. THIS WILL BE EVIDENT IN SFC DEWPOINTS NEAR 60-LOWER 60S. WITH MAINLY CLEAR SKIES ALOFT AND A LIGHT-NEAR CALM WIND REGIME...MAY SEE AREAS OF FOG DEVELOP WELL AFTER MIDNIGHT. MIN TEMPS UPPER 50S TO LOWER 60S. -WSS && .SHORT TERM /SATURDAY THROUGH SUNDAY/... AS OF 314 AM FRIDAY... SATURDAY...MID-UPPER LEVEL RIDGE OVER THE SE U.S. AND A SFC HIGH ANCHORED OFFSHORE WILL RESULT IN ANOTHER MOSTLY SUNNY AND WARM DAY. THICKNESSES STEADY IN THE 1410-1415M SO EXPECT SIMILAR HIGHS TEMPS COMPARED TO TODAY....MID-UPPER 80S (POSSIBLY 90 IN THE SANDHILLS). WITH SFC DEWPOINTS IN THE LOWER 60S...IT WILL START FEEL A BIT UNCOMFORTABLE TO MOST FOLKS. BY SATURDAY NIGHT...T.C. KAREN WILL BE LURKING OFF THE NORTHERN GULF OF MEXICO COAST. MEANWHILE A DEEP UPPER LEVEL LOW WILL BE OVER THE CENTRAL PLAINS. THESE WEATHER FEATURES WILL SERVE TO WEAKEN THE UPPER LEVEL RIDGE OVER THE SE U.S. THIS PROCESS WILL ALLOW LOW AND UPPER LEVEL MOISTURE TO INCREASE ACROSS CENTRAL NC SATURDAY NIGHT INTO SUNDAY. WITH SFC DEWPOINTS SOLIDLY IN THE LOWER 60S AND SKIES MOSTLY CLEAR TO START...AREAS OF FOG SHOULD DEVELOP ONCE AGAIN. MIN TEMPS MAINLY NEAR 60-LOWER 60S. SUNDAY...EXPECT TO SEE AN INCREASE IN CLOUDINESS AS MID-UPPER LEVEL WINDS BACK IN RESPONSE TO THE EWD ADVANCING UPPER LEVEL LOW MOVING INTO THE WESTERN GREAT LAKES. THIS WEATHER SYSTEM WILL ALSO CAUSE T.C. KAREN TO LIFT NEWD INTO THE SE U.S. LATE SUNDAY-SUNDAY NIGHT. THE AIR MASS OVER CENTRAL NC WILL QUICKLY BECOME MOISTURE LADEN...ESPECIALLY IN THE WEST. INCREASING DIVERGENCE ALOFT COUPLED WITH WEAK ISENTROPIC UPGLIDE WILL SUPPORT THE DEVELOPMENT OF A FEW SHOWERS LATE IN THE DAY...MAINLY OVER THE SW THIRD OF THE FORECAST AREA. EXTENT/THICKNESS OF CLOUD COVER BY SUNDAY AFTERNOON WILL PLAY A ROLE IN AFTERNOON TEMPS. BELIEVE THAT THERE WILL BE ENOUGH PARTIAL SUN SUNDAY AFTERNOON TO WARM TEMPS BACK INTO THE MID 80S OVER MOST OF THE REGION. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... AS OF 235 AM FRIDAY... ...KAREN`S REMNANTS WILL AFFECT NC SUNDAY NIGHT THROUGH TUESDAY MORNING... MODEL SOLUTIONS CONCERNING FINER DETAILS OF THE TRACK OF TROPICAL CYCLONE KAREN AND ITS INTERACTION WITH AN APPROACHING COLD FRONT ARE STILL ON THE LOWER END OF THE CONFIDENCE SCALE. ON THE OTHER HAND...WHILE IT IS TOO EARLY TO PINPOINT A NARROW TIME WINDOW OF HEAVY RAIN...A SIGNIFICANT AND WIDESPREAD BENEFICIAL RAIN EVENT APPEARS LIKELY AS THE TROPICAL MOISTURE PLUME FROM KAREN SPREADS INTO THE WEST SUNDAY AFTERNOON/EVENING...AND OVER MOST OF CENTRAL NORTH CAROLINA BY MONDAY MORNING. WIDESPREAD RAINFALL AMOUNTS OF >1 INCH ARE A GOOD BET...AND A STRIPE OF 2+ INCHES CAN REASONABLY BE EXPECTED ALONG AND WEST OF THE EVENTUAL TRACK...WHICH IS NOT CERTAIN AT THIS POINT BUT HAS A GOOD CHANCE OF BEING OVER OR JUST SKIRTING THE CWFA. THE POTENTIAL FOR VERY HEAVY SHOWERS WITH HIGH RAINFALL RATES AND TRAINING CELLS WOULD PRODUCE A THREAT FOR FLASH FLOODING...WHICH WOULD BE MORE LIKELY IN MORE URBANIZED AREAS. CHANGES TO THE FORECAST AT THIS POINT ARE TO INCREASE POPS LATER SUNDAY NIGHT AND MONDAY...WITH A NUDGE UPWARDS IN THE AMOUNTS AS WELL. WILL CONTINUE PROGRESSIVE TAPERING OFF OF THE PRECIP MONDAY NIGHT...WITH LINGERING SHOWERS IN THE NORTHEAST ON TUESDAY. HIGH TEMPS ON MONDAY AND TUESDAY WILL BE IN THE 70S...PERHAPS SOME NEAR 80 READINGS IN THE EAST MONDAY IF PRECIP SPREADS IN A LITTLE SLOWER. MODEL DIVERGENCE IS MORE EVIDENT AS TO LATER DEVELOPMENTS DUE TO DIFFERENCES IN THE EVOLUTION OF A MID-LATE WEEK CUTOFF LOW AND A REX-ISH BLOCKING PATTERN. THE ECMWF AND GFS TAKE DIFFERING ROUTES TO ARRIVE AT A RATHER SIMILAR LOOKING PATTERN. ECMWF DEVELOPS THE CUTOFF TO THE WEST AND MEANDERS IT NORTHEAST AND NEARLY OVERHEAD... WHILE THE GFS DEVELOPS THE CUTOFF OVER NORTHEAST NC AND RETROGRADES IT WEST AND OVERHEAD. AT THIS EARLY JUNCTURE WILL HOLD OFF MAKING ANY CHANGES TO THE ONGOING DRY AND SLIGHTLY BELOW SEASONABLE FORECAST BEYOND TUESDAY AS WE AWAIT LATER MODEL CONSENSUS. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... AS OF 1007 AM FRIDAY... EXPECT VFR CONDITIONS THROUGH 06Z SATURDAY UNDER A LIGHT WIND REGIME...MOSTLY WEST IN DIRECTION BACKING TO SOUTH OR SOUTHWEST... THOUGH SOMEWHAT VARIABLE ESPECIALLY EARLY THIS AFTERNOON. AREAS OF FOG ARE EXPECTED TO BE MORE COMMON ACROSS CENTRAL NC LATE TONIGHT INTO EARLY SATURDAY MORNING...AND AGAIN LATE SATURDAY NIGHT INTO EARLY SUNDAY. WIDESPREAD IFR-LIFR VISIBILITIES ARE HIGHLY PROBABLE. THE FOG SHOULD LIFT AND DISSIPATE BY 15Z EACH DAY. OTHERWISE...A CONTINUATION OF VFR CONDITIONS EXPECTED AS HIGH PRESSURE LINGERS OVER THE REGION. AN APPROACHING COLD FRONT COUPLED WITH THE REMNANTS OF TROPICAL CYCLONE KAREN WILL LIKELY BRING ADVERSE AVIATION WEATHER CONDITIONS TO CENTRAL NC...POSSIBLY BEGINNING AS EARLY AS SUNDAY EVENING...BUT MORE LIKELY MONDAY INTO TUESDAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...WSS NEAR TERM...DJF/WSS SHORT TERM...WSS LONG TERM...MLM AVIATION...DJF/WSS
AREA FORECAST DISCUSSION
NWS TULSA OK
942 PM CDT SAT OCT 5 2013 .DISCUSSION... BACK EDGE OF RAIN APPEARS TO FINALLY BE PUSHING OUT OF FAR SOUTHEAST OK AT THIS TIME WITH SKIES CLEARING IN FAIRLY RAPID FASHION AS WELL. COOLEST TEMPS OF THE SEASON THUS FAR EXPECTED WITH SOME SPOTS ALREADY INTO MID 40S AS OF 930 PM. LIGHT SW WIND KEEPING TEMP AT KTUL SEVERAL DEGREES ABOVE SURROUNDING LOCATIONS...HOWEVER SHOULD SEE GRADUAL VEERING TO MORE NW COMPONENT WHICH SHOULD EVENTUALLY NEUTRALIZE URBAN EFFECT. BASED ON RADAR TRENDS WILL BE ABLE TO GO AHEAD AND REMOVE PRECIP FROM TONIGHT`S FORECAST BY 10 PM...AND WILL MAKE SOME MINOR CHANGES TO TEMPS AS WELL. && .PREV DISCUSSION... /ISSUED 630 PM CDT SAT OCT 5 2013/ DISCUSSION... THE 00Z TAF DISCUSSION IS INCLUDED BELOW. AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. ALL SITES TRENDING TO VFR BY THE START OF THE TAF PERIOD. SOME LINGERING MOISTURE NEAR THE GROUND AT KFSM COULD LEAD TO SOME LIGHT MVFR FOG AROUND 12Z. LIGHT WINDS WILL BECOME NWRLY AT 10 TO 20 KTS AFT 15Z SUNDAY MORNING. LACY PREV DISCUSSION... /ISSUED 326 PM CDT SAT OCT 5 2013/ DISCUSSION... BAND OF ONGOING CONVECTION IS ALIGNED ALONG THE 850MB FRONT...AND GIVEN THE LATEST RUC PROJECTIONS...THIS BOUNDARY WILL BE ACROSS FAR WESTERN AR INTO EXTREME SE OK BY 00Z AND PUSHING EASTWARD. ANY EVENING PRECIP WILL BE CONFINED TO THIS ZONE BEFORE PUSHING FURTHER EASTWARD AND CLEAR OF THE FORECAST AREA. SKIES WILL CONTINUE TO CLEAR FROM NW TO SE AND ALLOW FOR A COOL SUNDAY MORNING. BREEZY NORTHWEST WINDS WILL DEVELOP SUNDAY WHILE TEMPERATURES REMAIN BELOW SEASONAL NORMALS. WINDS WILL DROP OFF AROUND SUNSET AND ALLOW TEMPS TO FALL QUICKLY. A SEVERAL DAY WARMING TREND COMMENCES MONDAY WITH TEMPS RETURNING TO ABOVE NORMAL READINGS BY MID WEEK. THE WARM AND DRY WEATHER WILL PREVAIL INTO THE WEEKEND WHEN THE NEXT STORM SYSTEM PUSHES INTO THE PLAINS. WILL INTRODUCE LOW PRECIP CHANCES FOR NEXT WEEKEND PENDING THE EVOLUTION OF THIS SYSTEM. && .PRELIMINARY POINT TEMPS/POPS... TUL 46 70 45 75 / 0 0 0 0 FSM 46 71 46 75 / 10 0 0 0 MLC 43 72 43 77 / 10 0 0 0 BVO 40 69 40 75 / 0 10 0 0 FYV 41 65 39 70 / 10 0 0 0 BYV 43 63 44 69 / 10 0 0 0 MKO 42 70 42 75 / 10 0 0 0 MIO 42 66 42 72 / 0 10 0 0 F10 43 71 44 76 / 0 0 0 0 HHW 47 76 44 79 / 20 0 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ SHORT TERM...14 LONG TERM....99
AREA FORECAST DISCUSSION
NWS TULSA OK
630 PM CDT SAT OCT 5 2013 .DISCUSSION... THE 00Z TAF DISCUSSION IS INCLUDED BELOW. && .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. ALL SITES TRENDING TO VFR BY THE START OF THE TAF PERIOD. SOME LINGERING MOISTURE NEAR THE GROUND AT KFSM COULD LEAD TO SOME LIGHT MVFR FOG AROUND 12Z. LIGHT WINDS WILL BECOME NWRLY AT 10 TO 20 KTS AFT 15Z SUNDAY MORNING. LACY && .PREV DISCUSSION... /ISSUED 326 PM CDT SAT OCT 5 2013/ DISCUSSION... BAND OF ONGOING CONVECTION IS ALIGNED ALONG THE 850MB FRONT...AND GIVEN THE LATEST RUC PROJECTIONS...THIS BOUNDARY WILL BE ACROSS FAR WESTERN AR INTO EXTREME SE OK BY 00Z AND PUSHING EASTWARD. ANY EVENING PRECIP WILL BE CONFINED TO THIS ZONE BEFORE PUSHING FURTHER EASTWARD AND CLEAR OF THE FORECAST AREA. SKIES WILL CONTINUE TO CLEAR FROM NW TO SE AND ALLOW FOR A COOL SUNDAY MORNING. BREEZY NORTHWEST WINDS WILL DEVELOP SUNDAY WHILE TEMPERATURES REMAIN BELOW SEASONAL NORMALS. WINDS WILL DROP OFF AROUND SUNSET AND ALLOW TEMPS TO FALL QUICKLY. A SEVERAL DAY WARMING TREND COMMENCES MONDAY WITH TEMPS RETURNING TO ABOVE NORMAL READINGS BY MID WEEK. THE WARM AND DRY WEATHER WILL PREVAIL INTO THE WEEKEND WHEN THE NEXT STORM SYSTEM PUSHES INTO THE PLAINS. WILL INTRODUCE LOW PRECIP CHANCES FOR NEXT WEEKEND PENDING THE EVOLUTION OF THIS SYSTEM. && .PRELIMINARY POINT TEMPS/POPS... TUL 46 70 45 75 / 0 0 0 0 FSM 46 71 46 75 / 20 0 0 0 MLC 43 72 43 77 / 10 0 0 0 BVO 40 69 40 75 / 0 10 0 0 FYV 41 65 39 70 / 10 0 0 0 BYV 43 63 44 69 / 30 0 0 0 MKO 42 70 42 75 / 10 0 0 0 MIO 42 66 42 72 / 0 10 0 0 F10 43 71 44 76 / 0 0 0 0 HHW 47 76 44 79 / 30 0 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
801 AM EDT FRI OCT 4 2013 .SYNOPSIS... A WARM FRONT DRAPED JUST TO THE NORTH OF THE STATE WILL STAY IN PLACE OVER THE NEXT FEW DAYS. FAST WESTERLY FLOW ALOFT WILL ALLOW A SERIES OF WEAK WAVES TO ROLL ACROSS THE AREA THIS WEEKEND. A STRONG COLD FRONT WILL MOVE THROUGH LATE SUNDAY OR EARLY MONDAY. TROPICAL MOISTURE FROM TROPICAL STORM KAREN MAY BE DRAWN INTO THE STATE FROM THE SOUTH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 5 PM THIS AFTERNOON/... CLOUDS ASSOCIATED WITH A DYING SHORTWAVE ARE BREAKING UP AS THEY TRY TO TRAVEL ACROSS THE CENTRAL MOUNTAINS. HOWEVER...ANOTHER WAVE IS MOVING DOWN FROM MICHIGAN...AND SHOULD PASS THROUGH LATE THIS MORNING AND THROUGH THE AFTERNOON. THIS SHORTWAVE WILL ENHANCE THE LIFT OF ANOMALOUSLY WARM AND MOIST AIR OVER THE REGION FOR EARLY OCTOBER. EXPECT SCT SHRA AND ISOLD TSRA TO FORM THROUGH THE MORNING HOURS IN WRN PA AND ROLL INTO THE AREA. MOST OF THE SHOWERS SHOULD BE TO THE NW OF AOO/UNV/IPT...BUT ISOLD SHRA ARE POSS IN THE SE. WILL KEEP A 20 POP THERE FOR THE MORNING...BUT RAISE THEM TO SCT POPS IN THE AFTERNOON. SHOWERS WILL BE MOVING ALONG STEADILY WITH GENERAL 20-30KT WEST WIND FOR THE ENTIRE ATMOS BELOW 300MB. PWATS IN THE 1.5 INCH RANGE WILL ALLOW FOR A FEW INTENSE BUT VERY BRIEF DOWNPOURS. MAXES WILL BE LIMITED BY THE CLOUD COVER OVER THE NORTH...BUT BIG BREAKS IN THE SRN HALF OF THE AREA WILL HELP TEMPS TO GET ABOVE 80F OVER ALMOST HALF THE AREA. STILL...THESE ARE WAYYYY ABOVE NORMS FOR THE DATE. && .SHORT TERM /5 PM THIS AFTERNOON THROUGH 6 PM SATURDAY/... SHORT WAVE SHOULD BE PUSHING TO THE EAST AND TAKING THE SHOWERS/THUNDER WITH IT AS LOW SUN ANGLE/SHORTER DAYS LIMIT THE INSTABILITY. WARM FRONT REMAINS GENERALLY TO THE NORTH...BUT SKY SHOULD BE CLOUDY IN THE NE AND PARTLY CLOUDY ELSEWHERE TONIGHT. ONCE AGAIN...DEWPOINTS HIGH FOR THE DATE AND TEMPS WILL STAY MUCH ABOVE NORMALS WITH MINS NEAR 55F IN THE N AND NEAR 60F IN THE S. RIDGE ALOFT PUMPS UP SLIGHTLY DURING THE DAY ON SATURDAY. BUT THE FRONT TO OUR NORTH MAY PUSH SOUTHWARD A HUNDRED MILES OR SO...KEEPING A LOW THREAT OF RAIN IN THE NORTH LATER TONIGHT AND INTO SAT NIGHT. DIURNAL CONVECTION COULD CREATE SHOWERS OVER THE WRN HILLS SAT AFTN...BUT THESE SHOULD BREAK UP AS THEY TRY TO MOVE ACROSS THE CWA. THE HIGHER CLOUD COVER IN THE N/NE SHOULD KEEP MAXES TO THE M70S...BUT ALL OTHER LOCATIONS SHOULD ADD A DEG OR TWO TO FRI/S MAXES WITH MORE SUN/LESS CLOUDS ON THE WHOLE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... DIGGING TROUGH EXITS THE ROCKY MTNS ON FRI AND SLOWLY HEADS TOWARD THE GREAT LAKES THROUGH THE WEEKEND...PUSHING A COLD FRONT GRADUALLY TOWARD PENNSYLVANIA. THIS WEEKEND WILL FEATURE A WEAK W-E ORIENTED WARM FRONT SNAKED ACROSS THE REGION THAT WILL LIFT INTO NY STATE...ALLOWING A WARM AND FAIRLY HUMID AIRMASS TO SETTLE IN OVER THE FCST AREA. MODELS CONTINUE TO SPLASH AROUND SOME LIGHT QPF WHICH SEEMS MAINLY DIURNALLY FAVORED...BUT ODDS ARE THAT FOR MAJORITY IF CENTRAL PA IT SHOULD BE A MAINLY NICE AND DRY WEEKEND. BEST CHANCES FOR LIGHT SHOWERS WILL BE IN THE NORTH AND WEST. HIGH TEMPS WILL BE IN THE MID 70S TO LOWER 80S...A SOLID 15F ABOVE NORMAL. THEN FOCUS TURNS TO APPROACHING COLD FRONT. GUIDANCE HAS TRENDED BACK TO NOTABLE TIMING DIFFERENCES...WITH THE GFS MORE PROGRESSIVE IN BRINGING FRONT ACROSS SUN NIGHT...WHILE THE ECMWF HOLDS IT BACK UNTIL MONDAY AND THEN SLOWS THE FRONTAL BOUNDARY ORIENTED SW-NE OVER SOUTHEAST PA. SREF AND NAM ALSO SEEM TO FAVOR THE QUICKER FROPA...SO SHADED HIGHEST POPS TOWARD SUN NIGHT/EARLY MON...ESP IN THE WEST. EARLY NEXT WEEK THE ISSUE BECOMES HOW TROPICAL MOISTURE FROM EVENTUAL REMNANTS OF KAREN /MOVING TOWARD GULF COAST/ WILL ULTIMATELY INTERACT WITH THE LINGERING FRONTAL BOUNDARY OVER MID ATLANTIC STATES. BEST FORECAST REMAINS THAT KAREN WILL TRACK UP ALONG OR EVEN MORE LIKELY EAST OF THE COLD FRONT THROUGH THE CAROLINAS AND THEN OFF THE MID ATLC COAST...NOT BEING A THREAT TO PA. THE ECMWF IS A SIG OUTLIER...TAKING THE STORM FURTHER WEST AND ABSORBING IT INTO ITS SLOWER MOVING FRONT...BRINGING SIG RAINS UP INTO WESTERN/CENTRAL PA FOR MID NEXT WEEK. I DID SHADE POPS IN EASTERN COUNTIES A LITTLE HIGHER...HOLDING ONTO POPS FURTHER INTO TUE ATTM. QUIET AND SLIGHTLY COOLER WEATHER WILL ULTIMATELY RETURN FOR MIDWEEK AFTER THE FRONT AND TROPICAL MOISTURE MOVES THROUGH...DROPPING TEMPS BACK TOWARD YET STILL SLIGHTLY ABOVE NORMAL. BUT WITH THE LONGER RANGE MODELS ADVERTISING A RESURGENCE IN THE EASTERN RIDGE...WARMER AIR SHOULD MAKE A RETURN FOR THE LATTER HALF OF NEXT WEEK. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... WARM FRONT AND BULK OF SHRA HAVE LIFTED NORTH OF PA EARLY THIS MORNING. IN IT/S WAKE...LOW LVL MOISTURE ASCENDING THE NW MTNS IS PRODUCING LOW CIGS AT BFD. MDL SOUNDINGS SUGGEST IT WILL TAKE UNTIL ARND 15Z TO MIX OUT THESE LOW CIGS. ACROSS SOUTHEAST PA...CLEAR SKIES ALL NIGHT ALLOWED RADIATION FOG TO FORM AT LNS...WHERE THE 11Z VIS IS 1SM. LATEST HRRR AND NAMPARA SUGGEST THIS FOG BURNS OFF BTWN 13Z-14Z. WIDESPREAD VFR CONDS APPEAR NEARLY CERTAIN OVER MOST OF CENTRAL PA BY MIDDAY...WITH THE POSSIBLE EXCEPTION OF BFD. A FEW LATE DAY SHRA/TSRA MAY DEVELOP ACROSS NORTHERN PA IN VICINITY OF QUASI- STATIONARY FRONT ACROSS UPSTATE NY. THUS...CAN/T RULE OUT A BRIEF LATE DAY VSBY REDUCTION AT THE NORTHERN PA AIRFIELDS. MCLEAR SKIES...A CALM WIND AND ABUNDANT LOW LVL MOISTURE SHOULD LEAD TO AREAS OF FOG TONIGHT. MANY LOCATIONS WILL LIKELY BECOME IFR BY DAWN ACROSS NORTHERN PA BASED ON LATEST SREF OUTPUT. OUTLOOK... SAT...AM FOG POSSIBLE...MAINLY NORTH. ISOLD PM TSRA IMPACTS POSS NORTH. SUN...AM FOG POSS EAST. ISOLD PM TSRA IMPACTS POSS W MTNS. MON...SHRA/LOW CIGS POSSIBLE...ESP EARLY. TUE...SLIGHT CHC OF SHRA/LOW CIGS SOUTHEAST. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO/GARTNER SHORT TERM...DANGELO LONG TERM...RXR AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
726 AM EDT FRI OCT 4 2013 .SYNOPSIS... A WARM FRONT DRAPED JUST TO THE NORTH OF THE STATE WILL STAY IN PLACE OVER THE NEXT FEW DAYS. FAST WESTERLY FLOW ALOFT WILL ALLOW A SERIES OF WEAK WAVES TO ROLL ACROSS THE AREA THIS WEEKEND. A STRONG COLD FRONT WILL MOVE THROUGH LATE SUNDAY OR EARLY MONDAY. TROPICAL MOISTURE FROM TROPICAL STORM KAREN MAY BE DRAWN INTO THE STATE FROM THE SOUTH EARLY NEXT WEEK. && .NEAR TERM /UNTIL 5 PM THIS AFTERNOON/... CLOUDS ASSOCIATED WITH A DYING SHORT WAVE ARE BREAKING UP AS THEY TRY TO TRAVEL ACROSS THE CENTRAL MOUNTAINS. HOWEVER...ANOTHER WAVE IS MOVING DOWN FROM MICHIGAN...AND SHOULD PASS THROUGH LATE THIS MORNING AND THOUGH THE AFTERNOON. THIS SHORT WAVE WILL ENHANCE THE LIFT OF ANOMALOUSLY WARM AND MOIST AIR FOR EARLY OCTOBER. EXPECT SCT SHRA AND ISOLD TSRA TO FORM THIS MORNING IN WRN PA AND ROLL INTO THE AREA. MOST OF THE SHOWERS SHOULD BE TO THE NW OF AOO/UNV/IPT...BUT ISLOD SHRA ARE POSS IN THE SE. WILL KEEP A 20 POP THERE FOR THE MORNING...BUT RAISE THEM TO SCT POPS IN THE AFTERNOON. SHOWERS WILL BE MOVING ALONG STEADILY WITH GENERAL 20-30KT WEST WIND FOR THE ENTIRE ATMOS BELOW 300MB. PWATS IN THE 1.5 INCH RANGE WILL ALLOW FOR A FEW INTENSE BUT VERY BRIEF DOWNPOURS. MAXES WILL BE LIMITED BY THE CLOUD COVER OVER THE NORTH...BUT BIG BREAKS IN THE SRN HALF OF THE AREA WILL HELP TEMPS TO GET ABOVE 80F OVER ALMOST HALF THE AREA. STILL...THESE ARE WAYYYY ABOVE NORMS FOR THE DATE. && .SHORT TERM /5 PM THIS AFTERNOON THROUGH 6 PM SATURDAY/... SHORT WAVE SHOULD BE PUSHING TO THE EAST AND TAKING THE SHOWERS/THUNDER WITH IT AS LOW SUN ANGLE/SHORTER DAYS LIMIT THE INSTABILITY. WARM FRONT REMAINS GENERALLY TO THE NORTH...BUT SKY SHOULD BE CLOUDY IN THE NE AND PARTLY CLOUDY ELSEWHERE TONIGHT. ONCE AGAIN...DEWPOINTS HIGH FOR THE DATE AND TEMPS WILL STAY MUCH ABOVE NORMALS WITH MINS NEAR 55F IN THE N AND NEAR 60F IN THE S. RIDGE ALOFT PUMPS UP SLIGHTLY DURING THE DAY ON SATURDAY. BUT THE FRONT TO OUR NORTH MAY PUSH SOUTHWARD A HUNDRED MILES OR SO...KEEPING A LOW THREAT OF RAIN IN THE NORTH LATER TONIGHT AND INTO SAT NIGHT. DIURNAL CONVECTION COULD CREATE SHOWERS OVER THE WRN HILLS SAT AFTN...BUT THESE SHOULD BREAK UP AS THEY TRY TO MOVE ACROSS THE CWA. THE HIGHER CLOUD COVER IN THE N/NE SHOULD KEEP MAXES TO THE M70S...BUT ALL OTHER LOCATIONS SHOULD ADD A DEG OR TWO TO FRI/S MAXES WITH MORE SUN/LESS CLOUDS ON THE WHOLE. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... DIGGING TROUGH EXITS THE ROCKY MTNS ON FRI AND SLOWLY HEADS TOWARD THE GREAT LAKES THROUGH THE WEEKEND...PUSHING A COLD FRONT GRADUALLY TOWARD PENNSYLVANIA. THIS WEEKEND WILL FEATURE A WEAK W-E ORIENTED WARM FRONT SNAKED ACROSS THE REGION THAT WILL LIFT INTO NY STATE...ALLOWING A WARM AND FAIRLY HUMID AIRMASS TO SETTLE IN OVER THE FCST AREA. MODELS CONTINUE TO SPLASH AROUND SOME LIGHT QPF WHICH SEEMS MAINLY DIURNALLY FAVORED...BUT ODDS ARE THAT FOR MAJORITY IF CENTRAL PA IT SHOULD BE A MAINLY NICE AND DRY WEEKEND. BEST CHANCES FOR LIGHT SHOWERS WILL BE IN THE NORTH AND WEST. HIGH TEMPS WILL BE IN THE MID 70S TO LOWER 80S...A SOLID 15F ABOVE NORMAL. THEN FOCUS TURNS TO APPROACHING COLD FRONT. GUIDANCE HAS TRENDED BACK TO NOTABLE TIMING DIFFERENCES...WITH THE GFS MORE PROGRESSIVE IN BRINGING FRONT ACROSS SUN NIGHT...WHILE THE ECMWF HOLDS IT BACK UNTIL MONDAY AND THEN SLOWS THE FRONTAL BOUNDARY ORIENTED SW-NE OVER SOUTHEAST PA. SREF AND NAM ALSO SEEM TO FAVOR THE QUICKER FROPA...SO SHADED HIGHEST POPS TOWARD SUN NIGHT/EARLY MON...ESP IN THE WEST. EARLY NEXT WEEK THE ISSUE BECOMES HOW TROPICAL MOISTURE FROM EVENTUAL REMNANTS OF KAREN /MOVING TOWARD GULF COAST/ WILL ULTIMATELY INTERACT WITH THE LINGERING FRONTAL BOUNDARY OVER MID ATLANTIC STATES. BEST FORECAST REMAINS THAT KAREN WILL TRACK UP ALONG OR EVEN MORE LIKELY EAST OF THE COLD FRONT THROUGH THE CAROLINAS AND THEN OFF THE MID ATLC COAST...NOT BEING A THREAT TO PA. THE ECMWF IS A SIG OUTLIER...TAKING THE STORM FURTHER WEST AND ABSORBING IT INTO ITS SLOWER MOVING FRONT...BRINGING SIG RAINS UP INTO WESTERN/CENTRAL PA FOR MID NEXT WEEK. I DID SHADE POPS IN EASTERN COUNTIES A LITTLE HIGHER...HOLDING ONTO POPS FURTHER INTO TUE ATTM. QUIET AND SLIGHTLY COOLER WEATHER WILL ULTIMATELY RETURN FOR MIDWEEK AFTER THE FRONT AND TROPICAL MOISTURE MOVES THROUGH...DROPPING TEMPS BACK TOWARD YET STILL SLIGHTLY ABOVE NORMAL. BUT WITH THE LONGER RANGE MODELS ADVERTISING A RESURGENCE IN THE EASTERN RIDGE...WARMER AIR SHOULD MAKE A RETURN FOR THE LATTER HALF OF NEXT WEEK. && .AVIATION /11Z FRIDAY THROUGH TUESDAY/... WARM FRONT AND BULK OF SHRA HAVE LIFTED NORTH OF PA EARLY THIS MORNING. IN IT/S WAKE...LOW LVL MOISTURE ASCENDING THE NW MTNS IS PRODUCING LOW CIGS AT BFD. MDL SOUNDINGS SUGGEST IT WILL TAKE UNTIL ARND 15Z TO MIX OUT THESE LOW CIGS. ACROSS SOUTHEAST PA...CLEAR SKIES ALL NIGHT ALLOWED RADIATION FOG TO FORM AT LNS...WHERE THE 11Z VIS IS 1SM. LATEST HRRR AND NAMPARA SUGGEST THIS FOG BURNS OFF BTWN 13Z-14Z. WIDESPREAD VFR CONDS APPEAR NEARLY CERTAIN OVER MOST OF CENTRAL PA BY MIDDAY...WITH THE POSSIBLE EXCEPTION OF BFD. A FEW LATE DAY SHRA/TSRA MAY DEVELOP ACROSS NORTHERN PA IN VICINITY OF QUASI- STATIONARY FRONT ACROSS UPSTATE NY. THUS...CAN/T RULE OUT A BRIEF LATE DAY VSBY REDUCTION AT THE NORTHERN PA AIRFIELDS. MCLEAR SKIES...A CALM WIND AND ABUNDANT LOW LVL MOISTURE SHOULD LEAD TO AREAS OF FOG TONIGHT. MANY LOCATIONS WILL LIKELY BECOME IFR BY DAWN ACROSS NORTHERN PA BASED ON LATEST SREF OUTPUT. OUTLOOK... SAT...AM FOG POSSIBLE...MAINLY NORTH. ISOLD PM TSRA IMPACTS POSS NORTH. SUN...AM FOG POSS EAST. ISOLD PM TSRA IMPACTS POSS W MTNS. MON...SHRA/LOW CIGS POSSIBLE...ESP EARLY. TUE...SLIGHT CHC OF SHRA/LOW CIGS SOUTHEAST. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...RXR AVIATION...FITZGERALD
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
541 PM MDT SAT OCT 5 2013 .SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT ISSUED AT 301 PM MDT SAT OCT 5 2013 THE STORM CONTINUES TO WIND DOWN SLOWLY FOR THE BLACK HILLS REGION THIS AFTERNOON. A STRONG CLOSED LOW OVER EASTERN SOUTH DAKOTA IS MAKING A LITTLE PROGRESS EASTWARD THIS AFTERNOON. THE RESULT FOR THE WESTERN HALF OF THE STATE IS DECREASING SNOWFALL AND WIND AS THE WEAKENING BAND OF PRECIPITATION AND STRONG WIND SHFTS EASTWARD. THE 18Z HRRR SHOWS THE SURFACE LOW CENTER WEAKENING RAPIDLY AND REFORMING OVER MINNESOTA DURING THE NEXT SEVERAL HOURS. AS THE SYSTEM MOVES INTO CENTRAL SOUTH DAKOTA BOTH THE PRECIPITATION RATE AND DURATION OF STRONG WINDS ARE EXPECTED TO DECREASE RESULTING IN A LESS POTENT EVENT IN THOSE PARTS. A MUCH WELCOME DAY OF BLUE SKIES AND SUNSHINE ARE IN STORE FOR SUNDAY AS A TRANSITORY HIGH PRESSURE RIDGE SHIFTS INTO THE HIGH PLAINS. GUIDANCE WARMING SEEMS A LITTLE TOO AGGRESSIVE CONSIDERING THE EXTENSIVE SNOWPACK WE`VE ACQUIRED SO TEMPS WERE TRIMMED DOWN A BIT. THIS IS BETTER THAN A RAPID MELTOFF ANYWAY. WILL HAVE TO KEEP AN EYE ON HOW THE STREAMS RESPOND OVER THE NEXT COUPLE OF DAYS. THE MILD SUNNY WEATHER IS FORECAST TO CONTINUE MONDAY AS THE RIDGE LINGERS OVER THE REGION. && .LONG TERM...MONDAY THROUGH SATURDAY ISSUED AT 301 PM MDT SAT OCT 5 2013 PROGRESSIVE LONG WAVE RIDGE BUILDS IN BEHIND THE RECORD-BREAKING BLIZZARD... MOVING QUICKLY FROM NEAR 110W ON MON TO JUST E OF 100W ON TUE AND TO 85W ON WED. AS IT DOES SO...A NEW LONG WAVE TROF IS CARVED OUT IN THE WEST. GFS CONTINUES TREND OF LAST SEVERAL RUNS IN SPLITTING OFF A NRN STREAM SHORT WAVE AND MOVING IT ACROSS WRN CAN WHILE THE STRONGER PORTION OF THE WAVE DIGS S WARD INTO CA. BY 12Z WED A CLOSED LOW IS SHOWN OVER NRN CA. THE DIGGING PROCESS IS COMPLETED BY THU AT 12Z AND THE LOW IS FCST TO MOVE OUT TO THE NE...PERHAPS TO SE SD BY 12Z SAT. THIS RUN OF GFS IS SLIGHTLY FARTHER S AND E THAN YESTERDAY`S. WHILE THE TRACK IS REMINISCENT OF OUR PRESENT STORM...1000 TO 500MB THICKNESSES ARE PRESENTLY FCST TO BE WELL ABOVE SNOW RELATED VALUES AND THE UPPER LOW IS FAR LESS INTENSE. BUT IT IS EARLY IN THE GAME. ACCEPTED THE EXTENDED INIT TEMPS...THOUGH THEY ARE MUCH BELOW GFS MOS GUIDANCE FOR WED AND THU. THINKING IS THAT THERE WILL STILL BE SOME WET GROUND FROM THE HEAVY SNOW AND THAT THE STORM-FOLLOWING RIDGE IS FCST TO MOVE E WARD SO QUICKLY THAT UPPER LEVEL COOLING WILL ALREADY BE UNDERWAY AS THE TROF IN THE W INTENSIFIES AND APPROACHES THE AREA. CLOUDS...POPS...AND PRECIP BROUGHT IN THU NIGHT INTO SAT IN LINE WITH APPROACHING CLOSED LOW. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 527 PM MDT SAT OCT 5 2013 THE INTENSE CYCLONE OVER SE SD IS WEAKENING AS A SECOND CENTER FORMS IN SE MN THIS AFTN. RELAXING PRESSURE GRADIENTS WEST OF THE PRIMARY LOW ARE ASSOCIATED WITH GRADUALLY DIMINISHING WINDS OVER WRN SD. THIS PROCESS SHOULD CONTINUE THIS EVENING. RADAR DATA SHOW SEVERAL WEAKENING N-S BANDS OF LIGHT SNOW CONTINUING OVER ERN PORTIONS OF THE FCST AREA. IFR CIGS AND VSBYS ACCOMPANY THESE BANDS...BUT SHOULD BE IMPROVING AS THE BANDS CONTINUE TO WEAKEN. ELSEWHERE VFR CONDITIONS WITH ONLY HIGH CLOUDS ARE EVIDENT AND WILL BECOME THE RULE OVER THE ENTIRE FCST AREA LATER TONIGHT. SUNDAY SHOULD SEE VFR CONDITIONS WITH LIGHT...MOSTLY WESTERLY WINDS. NO OBSERVATIONS HAVE BEEN AVAILABLE SINCE FRIDAY AFTERNOON FROM KRAP DUE TO COMMUNICATIONS ISSUES. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WINTER STORM WARNING UNTIL 6 PM MDT THIS EVENING FOR SDZ044. WINTER WEATHER ADVISORY UNTIL 7 PM CDT THIS EVENING FOR SDZ046- 047-049. BLIZZARD WARNING UNTIL 6 PM MDT THIS EVENING FOR SDZ014-032-043. WY...NONE. && $$ SHORT TERM...CARPENTER LONG TERM...BARBER AVIATION...BARBER
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
101 PM CDT FRI OCT 4 2013 .UPDATE... 18Z AVIATION DISCUSSION UPDATED BELOW. SCATTERED/NUMEROUS SHOWERS WERE LIFTING NORTH ACROSS MAINLY CENTRAL AND NORTH CENTRAL SOUTH DAKOTA LATE THIS MORNING. ALSO...REPORTS IN WESTERN CORSON OF THE RAIN CHANGING OVER TO SNOW. THE LATEST HRRR RUN SHOWS MORE SHOWERS/THUNDERSTORMS DEVELOPING THIS AFTERNOON/EARLY EVENING ALONG DRY SLOT LIFTING NORTHWARD IN THE DEEPENING UPPER LOW PRESSURE AREA. ADDED SNOW OR RAIN/SNOW TO THE FAR WESTERN COUNTIES THROUGH THE AFTERNOON. THE OTHER ISSUE IS THE STRONG WINDS ALREADY OCCURRING. THE LATEST MODEL RUNS AND GUIDANCE SHOW THESE STRONG WINDS CONTINUING THROUGH THE AFTERNOON AND NIGHT. WINDS MAY BE CLOSE TO HIGH WINDS AT TIMES. WILL LEAVE WIND ADVISORY GOING THROUGH THE NIGHT AND MAY HAVE TO EXTEND THIS EVEN THROUGH SATURDAY. NOT MUCH CHANGE IN TEMPERATURES THROUGH THE AFTERNOON WITH CLOUD COVER AND PRECIPITATION. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH SATURDAY NIGHT HEADLINES OVER THE NEXT 24 TO 30 HOURS WILL BE THE MAIN FORECAST CHALLENGE. MODELS ARE IN A REASONABLE AGREEMENT THIS MORNING WITH THE HANDLING OF THE FIRST SNOWSTORM OF THE SEASON. ISENTROPIC UPGLIDE IS CURRENTLY ONGOING OVER WESTERN SOUTH DAKOTA WHERE WIDESPREAD LIGHT TO MODERATE RAIN IS OCCURRING. SO FAR ONLY THE HIGHER TERRAIN AREAS OF THE BLACK HILLS AND EASTERN WYOMING HAS TRANSITIONED OVER TO ALL SNOW. WITH LIMITED CAA...WAA AT H7...NOT TOO SURPRISED TO SEE A SLOW TRANSITION OVER TO SNOW. THE 0Z MODEL RUNS OF THE GFS/NAM/HI-RES ARW ALL SUGGEST LITTLE TO NO SNOW FOR LOCATIONS ALONG AND EAST OF THE MISSOURI RIVER FOR THIS EVENT. A FEW MODELS ACTUALLY SHOW KPIR CHANGING OVER TO SNOW SEVERAL HOURS BEFORE KMBG DOES DUE TO THE PLACEMENT OF THE H5 LOW PRESSURE. THERE WILL DEFINITELY BE A FINE LINE BETWEEN SIGNIFICANT SNOW ACCUMULATIONS AND NO SNOWFALL. WITH THE CENTRAL AND WESTERN PORTIONS OF CORSON AND DEWEY COUNTY SEEING A MORE PROLONGED TIME PERIOD OF SNOW...HAVE UPGRADED THESE COUNTIES TO A WINTER STORM WARNING. SINCE SNOW WILL BE DELAYED ELSEWHERE...WILL PUSH THE WINTER STORM WATCH BACK UNTIL 0Z. FURTHER EAST...MODELS HAVE DEVELOPED A NOTICEABLE DRY SLOT MOVING ACROSS THE EASTERN CWA AFTER 6Z SATURDAY. THE CONSENSUS AMONG MODELS WITH REGARDS TO QPF IS DRASTICALLY LOWER THAN THE PREVIOUS FORECAST. MODEL SOUNDINGS ARE MORE SUPPORTIVE OF CONTINUOUS DRIZZLE THAN MODERATE RAINFALL. HAVE LEFT OUT THE MENTION OF DRIZZLE FOR NOW HOWEVER. IT HAS BEEN NOTED FOR A WHILE NOW THAT IS STORM SYSTEM WILL BRING VERY STRONG NORTHERLY WINDS WITH GUSTS AROUND 50 MPH POSSIBLE. THE PREVIOUS FORECAST SHIFT HAD ALREADY ISSUED A WIND ADVISORY WHICH LOOKS REALLY GOOD. BASED ON THE GFS LAMP GUIDANCE...HAVE DECIDED TO ADD BROWN COUNTY INTO THE ADVISORY...AND HAVE EXTENDED THE ADVISORY IN TIME UNTIL 12Z SATURDAY. CONDITIONS SHOULD GRADUALLY IMPROVE DURING THE AFTERNOON HOURS ON SATURDAY FROM WEST TO EAST. .LONG TERM...SUNDAY THROUGH FRIDAY A QUIET PERIOD EXPECTED AFTER THE LOW CURRENTLY AFFECTING THE PLAINS EXITS THIS CWA SUNDAY MORNING. UPPER RIDGING AND A SURFACE BASED LEE SIDE TROUGH WILL MOVE IN FROM THE WEST ON MONDAY AND TEMPERATURES WILL REBOUND NICELY WITH EXPECTED HIGHS IN THE 60S THROUGH THE WEEK. WEAK SFC LOW PRESSURE WILL SPREAD OVER THE REGION BY WED BUT WILL BE MOISTURE STARVED INITIALLY. AS ANOTHER UPPER TROF MOVES IN THU NIGHT/FRIDAY AND A WELL STACKED LOW DEVELOPS OVER THE PLAINS PRECIP CHANCES INCREASE. && .AVIATION... 18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS STRONG UPPER LEVEL LOW PRESSURE AREA WILL CONTINUE TO WRAP RAIN/ISOLATED STORMS UP TO THE NORTHWEST AND WEST ACROSS ALL OF THE REGION THROUGH TONIGHT AND SATURDAY MORNING. THUS...HAVE RAIN/DRIZZLE/FOG IN FOR ALL LOCATIONS THROUGH SATURDAY MORNING ALONG WITH SOME VICINITY THUNDER IN THIS AFTERNOON AT MBG/PIR. ABR AND ATY MAY ALSO HAVE SOME THUNDER INTO THE EVENING HOURS. WILL WATCH FOR THIS. WITH THE DRY SLOT WRAPPING UP INTO THE REGION TONIGHT...MAY HAVE SOME DRIZZLE OCCUR AT ABR AND ATY. OTHERWISE...ADDED SOME RAIN/SNOW IN OUT WEST FOR PIR AND MBG AS TEMPERATURES FALL SOME OUT THERE. CEILINGS AND VISIBILITIES WILL BE IFR/LOW MVFR THROUGH THE FORECAST PERIOD. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ SATURDAY FOR BROWN- BUFFALO-CAMPBELL-CORSON-DEWEY-EDMUNDS-FAULK-HAND-HUGHES- HYDE-JONES-LYMAN-MCPHERSON-POTTER-STANLEY-SULLY-WALWORTH. WINTER STORM WATCH FROM 7 PM CDT /6 PM MDT/ THIS EVENING THROUGH SATURDAY AFTERNOON FOR CAMPBELL-HUGHES-JONES-POTTER-STANLEY- SULLY-WALWORTH. WINTER STORM WARNING UNTIL NOON MDT SATURDAY FOR CORSON-DEWEY. MN...NONE. && $$ UPDATE...MOHR SHORT TERM...SD LONG TERM...WISE AVIATION...MOHR WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...CORRECTED
NWS ABERDEEN SD
1054 AM CDT FRI OCT 4 2013 .UPDATE... SCATTERED/NUMEROUS SHOWERS ALONG WITH A FEW THUNDERSTORMS WERE LIFTING NORTH ACROSS MAINLY CENTRAL AND NORTH CENTRAL SOUTH DAKOTA LATE THIS MORNING. ALSO...REPORTS IN WESTERN CORSON OF THE RAIN CHANGING OVER TO SNOW. THE LATEST HRRR RUN SHOWS MORE SHOWERS/THUNDERSTORMS DEVELOPING THIS AFTERNOON/EARLY EVENING ALONG DRY SLOT LIFTING NORTHWARD IN THE DEEPENING UPPER LOW PRESSURE AREA. ADDED SNOW OR RAIN/SNOW TO THE FAR WESTERN COUNTIES THROUGH THE AFTERNOON. THE OTHER ISSUE IS THE STRONG WINDS ALREADY OCCURRING. THE LATEST MODEL RUNS AND GUIDANCE SHOW THESE STRONG WINDS CONTINUING THROUGH THE AFTERNOON AND NIGHT. WINDS MAY BE CLOSE TO HIGH WINDS AT TIMES. WILL LEAVE WIND ADVISORY GOING THROUGH THE NIGHT AND MAY HAVE TO EXTEND THIS EVEN THROUGH SATURDAY. NOT MUCH CHANGE IN TEMPERATURES THROUGH THE AFTERNOON WITH CLOUD COVER AND PRECIPITATION. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH SATURDAY NIGHT HEADLINES OVER THE NEXT 24 TO 30 HOURS WILL BE THE MAIN FORECAST CHALLENGE. MODELS ARE IN A REASONABLE AGREEMENT THIS MORNING WITH THE HANDLING OF THE FIRST SNOWSTORM OF THE SEASON. ISENTROPIC UPGLIDE IS CURRENTLY ONGOING OVER WESTERN SOUTH DAKOTA WHERE WIDESPREAD LIGHT TO MODERATE RAIN IS OCCURRING. SO FAR ONLY THE HIGHER TERRAIN AREAS OF THE BLACK HILLS AND EASTERN WYOMING HAS TRANSITIONED OVER TO ALL SNOW. WITH LIMITED CAA...WAA AT H7...NOT TOO SURPRISED TO SEE A SLOW TRANSITION OVER TO SNOW. THE 0Z MODEL RUNS OF THE GFS/NAM/HI-RES ARW ALL SUGGEST LITTLE TO NO SNOW FOR LOCATIONS ALONG AND EAST OF THE MISSOURI RIVER FOR THIS EVENT. A FEW MODELS ACTUALLY SHOW KPIR CHANGING OVER TO SNOW SEVERAL HOURS BEFORE KMBG DOES DUE TO THE PLACEMENT OF THE H5 LOW PRESSURE. THERE WILL DEFINITELY BE A FINE LINE BETWEEN SIGNIFICANT SNOW ACCUMULATIONS AND NO SNOWFALL. WITH THE CENTRAL AND WESTERN PORTIONS OF CORSON AND DEWEY COUNTY SEEING A MORE PROLONGED TIME PERIOD OF SNOW...HAVE UPGRADED THESE COUNTIES TO A WINTER STORM WARNING. SINCE SNOW WILL BE DELAYED ELSEWHERE...WILL PUSH THE WINTER STORM WATCH BACK UNTIL 0Z. FURTHER EAST...MODELS HAVE DEVELOPED A NOTICEABLE DRY SLOT MOVING ACROSS THE EASTERN CWA AFTER 6Z SATURDAY. THE CONSENSUS AMONG MODELS WITH REGARDS TO QPF IS DRASTICALLY LOWER THAN THE PREVIOUS FORECAST. MODEL SOUNDINGS ARE MORE SUPPORTIVE OF CONTINUOUS DRIZZLE THAN MODERATE RAINFALL. HAVE LEFT OUT THE MENTION OF DRIZZLE FOR NOW HOWEVER. IT HAS BEEN NOTED FOR A WHILE NOW THAT IS STORM SYSTEM WILL BRING VERY STRONG NORTHERLY WINDS WITH GUSTS AROUND 50 MPH POSSIBLE. THE PREVIOUS FORECAST SHIFT HAD ALREADY ISSUED A WIND ADVISORY WHICH LOOKS REALLY GOOD. BASED ON THE GFS LAMP GUIDANCE...HAVE DECIDED TO ADD BROWN COUNTY INTO THE ADVISORY...AND HAVE EXTENDED THE ADVISORY IN TIME UNTIL 12Z SATURDAY. CONDITIONS SHOULD GRADUALLY IMPROVE DURING THE AFTERNOON HOURS ON SATURDAY FROM WEST TO EAST. .LONG TERM...SUNDAY THROUGH FRIDAY A QUIET PERIOD EXPECTED AFTER THE LOW CURRENTLY AFFECTING THE PLAINS EXITS THIS CWA SUNDAY MORNING. UPPER RIDGING AND A SURFACE BASED LEE SIDE TROUGH WILL MOVE IN FROM THE WEST ON MONDAY AND TEMPERATURES WILL REBOUND NICELY WITH EXPECTED HIGHS IN THE 60S THROUGH THE WEEK. WEAK SFC LOW PRESSURE WILL SPREAD OVER THE REGION BY WED BUT WILL BE MOISTURE STARVED INITIALLY. AS ANOTHER UPPER TROF MOVES IN THU NIGHT/FRIDAY AND A WELL STACKED LOW DEVELOPS OVER THE PLAINS PRECIP CHANCES INCREASE. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS RAIN IS EXPECTED TO CONTINUE TO SPREAD ACROSS THE REMAINDER OF THE REGION TODAY. CURRENT CIGS AND VSBYS REMAIN IN THE VFR TO MVFR CATEGORIES...WITH THE EXCEPTION OF KATY WHERE A 300 FT STRATUS DECK IS ALREADY IN PLACE. CIGS ARE EXPECTED TO FALL TO IFR AT ALL SITES AS HEAVIER PRECIP MOVES IN. NORTHERLY WINDS WILL INCREASE TODAY TO 25 TO 35 KTS WITH HIGHER GUSTS. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ SATURDAY FOR BROWN- BUFFALO-CAMPBELL-CORSON-DEWEY-EDMUNDS-FAULK-HAND-HUGHES- HYDE-JONES-LYMAN-MCPHERSON-POTTER-STANLEY-SULLY-WALWORTH. WINTER STORM WATCH FROM 7 PM CDT /6 PM MDT/ THIS EVENING THROUGH SATURDAY AFTERNOON FOR CAMPBELL-HUGHES-JONES-POTTER-STANLEY- SULLY-WALWORTH. WINTER STORM WARNING UNTIL NOON MDT SATURDAY FOR CORSON-DEWEY. MN...NONE. && $$ UPDATE...MOHR SHORT TERM...SD LONG TERM...WISE AVIATION...MOHR WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1053 AM CDT FRI OCT 4 2013 .UPDATE... SCATTERED/NUMEROUS SHOWERS WERE LIFTING NORTH ACROSS MAINLY CENTRAL AND NORTH CENTRAL SOUTH DAKOTA LATE THIS MORNING. ALSO...REPORTS IN WESTERN CORSON OF THE RAIN CHANGING OVER TO SNOW. THE LATEST HRRR RUN SHOWS MORE SHOWERS/THUNDERSTORMS DEVELOPING THIS AFTERNOON/EARLY EVENING ALONG DRY SLOT LIFTING NORTHWARD IN THE DEEPENING UPPER LOW PRESSURE AREA. ADDED SNOW OR RAIN/SNOW TO THE FAR WESTERN COUNTIES THROUGH THE AFTERNOON. THE OTHER ISSUE IS THE STRONG WINDS ALREADY OCCURRING. THE LATEST MODEL RUNS AND GUIDANCE SHOW THESE STRONG WINDS CONTINUING THROUGH THE AFTERNOON AND NIGHT. WINDS MAY BE CLOSE TO HIGH WINDS AT TIMES. WILL LEAVE WIND ADVISORY GOING THROUGH THE NIGHT AND MAY HAVE TO EXTEND THIS EVEN THROUGH SATURDAY. NOT MUCH CHANGE IN TEMPERATURES THROUGH THE AFTERNOON WITH CLOUD COVER AND PRECIPITATION. && .PREVIOUS DISCUSSION... .SHORT TERM...TODAY THROUGH SATURDAY NIGHT HEADLINES OVER THE NEXT 24 TO 30 HOURS WILL BE THE MAIN FORECAST CHALLENGE. MODELS ARE IN A REASONABLE AGREEMENT THIS MORNING WITH THE HANDLING OF THE FIRST SNOWSTORM OF THE SEASON. ISENTROPIC UPGLIDE IS CURRENTLY ONGOING OVER WESTERN SOUTH DAKOTA WHERE WIDESPREAD LIGHT TO MODERATE RAIN IS OCCURRING. SO FAR ONLY THE HIGHER TERRAIN AREAS OF THE BLACK HILLS AND EASTERN WYOMING HAS TRANSITIONED OVER TO ALL SNOW. WITH LIMITED CAA...WAA AT H7...NOT TOO SURPRISED TO SEE A SLOW TRANSITION OVER TO SNOW. THE 0Z MODEL RUNS OF THE GFS/NAM/HI-RES ARW ALL SUGGEST LITTLE TO NO SNOW FOR LOCATIONS ALONG AND EAST OF THE MISSOURI RIVER FOR THIS EVENT. A FEW MODELS ACTUALLY SHOW KPIR CHANGING OVER TO SNOW SEVERAL HOURS BEFORE KMBG DOES DUE TO THE PLACEMENT OF THE H5 LOW PRESSURE. THERE WILL DEFINITELY BE A FINE LINE BETWEEN SIGNIFICANT SNOW ACCUMULATIONS AND NO SNOWFALL. WITH THE CENTRAL AND WESTERN PORTIONS OF CORSON AND DEWEY COUNTY SEEING A MORE PROLONGED TIME PERIOD OF SNOW...HAVE UPGRADED THESE COUNTIES TO A WINTER STORM WARNING. SINCE SNOW WILL BE DELAYED ELSEWHERE...WILL PUSH THE WINTER STORM WATCH BACK UNTIL 0Z. FURTHER EAST...MODELS HAVE DEVELOPED A NOTICEABLE DRY SLOT MOVING ACROSS THE EASTERN CWA AFTER 6Z SATURDAY. THE CONSENSUS AMONG MODELS WITH REGARDS TO QPF IS DRASTICALLY LOWER THAN THE PREVIOUS FORECAST. MODEL SOUNDINGS ARE MORE SUPPORTIVE OF CONTINUOUS DRIZZLE THAN MODERATE RAINFALL. HAVE LEFT OUT THE MENTION OF DRIZZLE FOR NOW HOWEVER. IT HAS BEEN NOTED FOR A WHILE NOW THAT IS STORM SYSTEM WILL BRING VERY STRONG NORTHERLY WINDS WITH GUSTS AROUND 50 MPH POSSIBLE. THE PREVIOUS FORECAST SHIFT HAD ALREADY ISSUED A WIND ADVISORY WHICH LOOKS REALLY GOOD. BASED ON THE GFS LAMP GUIDANCE...HAVE DECIDED TO ADD BROWN COUNTY INTO THE ADVISORY...AND HAVE EXTENDED THE ADVISORY IN TIME UNTIL 12Z SATURDAY. CONDITIONS SHOULD GRADUALLY IMPROVE DURING THE AFTERNOON HOURS ON SATURDAY FROM WEST TO EAST. .LONG TERM...SUNDAY THROUGH FRIDAY A QUIET PERIOD EXPECTED AFTER THE LOW CURRENTLY AFFECTING THE PLAINS EXITS THIS CWA SUNDAY MORNING. UPPER RIDGING AND A SURFACE BASED LEE SIDE TROUGH WILL MOVE IN FROM THE WEST ON MONDAY AND TEMPERATURES WILL REBOUND NICELY WITH EXPECTED HIGHS IN THE 60S THROUGH THE WEEK. WEAK SFC LOW PRESSURE WILL SPREAD OVER THE REGION BY WED BUT WILL BE MOISTURE STARVED INITIALLY. AS ANOTHER UPPER TROF MOVES IN THU NIGHT/FRIDAY AND A WELL STACKED LOW DEVELOPS OVER THE PLAINS PRECIP CHANCES INCREASE. && .AVIATION... 12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS RAIN IS EXPECTED TO CONTINUE TO SPREAD ACROSS THE REMAINDER OF THE REGION TODAY. CURRENT CIGS AND VSBYS REMAIN IN THE VFR TO MVFR CATEGORIES...WITH THE EXCEPTION OF KATY WHERE A 300 FT STRATUS DECK IS ALREADY IN PLACE. CIGS ARE EXPECTED TO FALL TO IFR AT ALL SITES AS HEAVIER PRECIP MOVES IN. NORTHERLY WINDS WILL INCREASE TODAY TO 25 TO 35 KTS WITH HIGHER GUSTS. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...WIND ADVISORY UNTIL 7 AM CDT /6 AM MDT/ SATURDAY FOR BROWN- BUFFALO-CAMPBELL-CORSON-DEWEY-EDMUNDS-FAULK-HAND-HUGHES- HYDE-JONES-LYMAN-MCPHERSON-POTTER-STANLEY-SULLY-WALWORTH. WINTER STORM WATCH FROM 7 PM CDT /6 PM MDT/ THIS EVENING THROUGH SATURDAY AFTERNOON FOR CAMPBELL-HUGHES-JONES-POTTER-STANLEY- SULLY-WALWORTH. WINTER STORM WARNING UNTIL NOON MDT SATURDAY FOR CORSON-DEWEY. MN...NONE. && $$ UPDATE...MOHR SHORT TERM...SD LONG TERM...WISE AVIATION...MOHR WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 PM CDT FRI OCT 4 2013 .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 330 PM CDT FRI OCT 4 2013 FORECAST CONCERNS ARE ON SEVERE THUNDERSTORM POTENTIAL TONIGHT AND THE POSSIBILITY OF A FEW SEVERE STORMS IN CENTRAL WISCONSIN LATE SATURDAY MORNING INTO EARLY SATURDAY AFTERNOON. LATEST SURFACE OBSERVATIONS SHOWED SURFACE LOW PRESSURE OVER CENTRAL NEBRASKA...LIFTING NORTHEAST. A WARM FRONT EXTENDED SOUTHEAST THROUGH SOUTHWEST AND CENTRAL IOWA. THE FRONT WILL LIFT NORTH LATE THIS AFTERNOON INTO THIS EVENING AND BE THE FOCUS FOR STRONG TO SEVERE THUNDERSTORM DEVELOPMENT AS A POTENT UPPER LOW PUSHES EAST ACROSS THE NEBRASKA PANHANDLE. THE WARM FRONT IS EXPECTED TO LIFT NORTH INTO NORTHERN IOWA AND PERHAPS EXTREME SOUTHWEST WISCONSIN THIS EVENING. STRONG 850 MB MOISTURE TRANSPORT FOCUSES INTO THE FRONT THIS EVENING...LEADING TO SHOWERS AND THUNDERSTORMS DEVELOPING OVER NORTHEAST IOWA...SOUTHEAST MINNESOTA AND PORTIONS OF SOUTHWEST WISCONSIN. MEANWHILE THE SURFACE LOW WILL LIFT NORTH INTO SOUTHEAST SOUTH DAKOTA AS THE LOW OCCLUDES. A TRIPLE POINT LIFTS NORTHEAST FROM NORTHEAST IOWA INTO SOUTH CENTRAL MINNESOTA LATE IN THE EVENING. THE 04.17 HRRR SHOWS ISOLATED STRONG STORMS DEVELOPING ALONG THE FRONT. STORMS ALSO DEVELOP OVER WESTERN IOWA EARLY THIS EVENING CLOSER TO THE OCCLUSION. THESE STORMS WILL LIKELY BE SUPERCELLS...CAPABLE OF PRODUCING LARGE HAIL...DAMAGING WINDS AND ISOLATED TORNADOES. THE STORMS FURTHER TO THE NORTH OVER THE FORECAST AREA...SHOULD BE NORTH OF THE WARM FRONT AND ELEVATED IN NATURE. 1-7 KM BULK SHEAR VALUES HOVER RIGHT AROUND 30 KTS DURING THE EVENING HOURS SO CANNOT RULE OUT ISOLATED SEVERE STORMS CAPABLE OF PRODUCING LARGE HAIL...HEAVY RAINFALL...AND POSSIBLY DAMAGING WINDS. THE HIGHEST CHANCES FOR SEVERE WEATHER WILL BE OVER NORTHEAST IOWA AND SOUTHEAST MINNESOTA...WEST OF HIGHWAY 52. A FEW OF THESE STRONGER STORMS COULD MAINTAIN INTENSITY INTO PORTIONS OF WESTERN WISCONSIN BUT SHOULD THEN WEAKEN AS THEY MOVE EAST...BUT STILL CAPABLE OF PRODUCING HEAVY RAINFALL. THE 850 MB MOISTURE TRANSPORT GRADUALLY SHIFTS EAST INTO WESTERN WISCONSIN OVERNIGHT WITH WIDESPREAD SHOWERS AND STORMS PERSISTING. THE MAIN THREAT FROM THE STORMS SHOULD GRADUALLY SHIFT TOWARDS HEAVY RAIN LATE IN THE NIGHT. A COLD FRONT THEN PUSHES EAST ACROSS THE REGION EARLY SATURDAY MORNING AND SHOULD BE POSITIONED RIGHT ALONG THE MISSISSIPPI RIVER BY THE MID TO LATE MORNING HOURS. IF ENOUGH INSTABILITY CAN BUILD AHEAD OF THE FRONT...THERE IS THE POSSIBILITY OF SEEING A FEW STRONG TO SEVERE STORMS OVER CENTRAL WISCONSIN. THE MAIN HAZARDS FROM THESE STORMS WOULD BE DAMAGING WINDS. SHOWERS AND STORMS WILL END FROM WEST TO EAST SATURDAY AFTERNOON AS A DRY SLOT PUSHES INTO THE REGION. TEMPERATURES SHOULD FALL ACROSS THE AREA SATURDAY AFTERNOON IN THE WAKE OF THE COLD FRONT. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 330 PM CDT FRI OCT 4 2013 MOST OF THE FORECAST AREA WILL REMAIN IN THE DRY SLOT SATURDAY NIGHT...WITH THE EXCEPTION OF NORTH CENTRAL WISCONSIN WHERE A FEW SHOWERS MAY LINGER. PLAN ON A COOLER NIGHT WITH LOWS FALLING INTO THE 40S. A FEW 30S CANNOT BE RULED OUT OVER CENTRAL WISCONSIN. THE UPPER LOW MOVES INTO INTO WESTERN IOWA ON SUNDAY AND EVENTUALLY INTO WESTERN ILLINOIS SUNDAY NIGHT. SHOWERS WRAPPING AROUND THE LOW LOOK TO MOVE INTO THE REGION SUNDAY AND WILL LIKELY CONTINUE INTO SUNDAY NIGHT AS THE LOW PROGRESSES EAST. THE LOW THEN LOOKS TO MOVE INTO THE EASTERN GREAT LAKES LATE ON TUESDAY WITH HIGH PRESSURE BUILDING INTO THE AREA IN ITS WAKE. HIGH PRESSURE THEN BUILDS OVER THE AREA WEDNESDAY INTO THURSDAY WITH DRY AND QUIET WEATHER EXPECTED...OUTSIDE OF THE POSSIBILITY OF OF SOME EARLY MORNING VALLEY FOG. A TROUGH IS EXPECTED TO DIG INTO THE SOUTHWEST CONUS LATE IN THE WEEK. SOUTHWEST FLOW LOOKS TO DEVELOP OVER THE UPPER MISSISSIPPI RIVER VALLEY LATE FRIDAY INTO SATURDAY. FORECAST MODELS SHOWS THE TROUGH EJECTING INTO THE CENTRAL AND NORTHERN PLAINS...WILL HAVE TO KEEP A VERY CLOSE EYE ON THIS SYSTEM OVER THE NEXT SEVERAL MODEL RUNS. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1217 PM CDT FRI OCT 4 2013 BULK OF AREA SOCKED UNDER IFR TO LIFR CONDITIONS NORTH OF A BOUNDARY THAT LIES CLOSER TO HIGHWAY 20 IN IOWA. THESE CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH IN THE SHORT TERM BUT AS DYNAMICS TAKE OVER WITH SIGNIFICANT UPPER LOW PROGRESSING INTO CENTRAL STATES... WIDESPREAD LIFT AND ASSOCIATED CONVECTION SHOULD REFORM TO THE SOUTHWEST AND SWEEP IN. HIGHEST RISK FOR CONVECTION IS IN EVENING HOURS AND INTO THE OVERNIGHT...WHERE VISIBILITIES COULD ACTUALLY IMPROVE A BIT UNDER THE RAIN. CEILINGS THOUGH WILL REMAIN LOW SIDE FOR POOR AVIATION WEATHER OVERALL. MAIN COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL BE SWEEPING THROUGH ON SATURDAY. BESIDES WIND SHIFT...EXPECT RAPIDLY IMPROVING CONDITIONS AS COOLER AND DRIER AIR SWEEPS IN. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1217 PM CDT FRI OCT 4 2013 .UPDATE...(SEVERE WEATHER RISK TODAY/TONIGHT) ISSUED AT 1027 AM CDT FRI OCT 4 2013 SETUP FOR LATER TODAY EVEN MORE MUDDLED WITH MAIN WARM FRONT SO FAR SOUTH AT MOMENT. TRENDS IN MESOSCALE GUIDANCE AND OBSERVATIONS SUGGEST...AS PREVIOUS FORECASTERS POINTED OUT...THAT HIGH RISK OF SEVERE WEATHER APPEARS TO BE SHIFTING WEST AND SOUTH. STORM PREDICTION CENTER GUIDANCE ALSO TRENDING THAT WAY AND WILL BE INTERESTING TO SEE WHAT LATER UPDATES PROGRESS TO. ALONG AND NORTH OF INTERSTATE 90...COOL FLOW NORTH OF BOUNDARY SEEMS TO BE WELL ESTABLISHED AND REINFORCING LOW CLOUDS AND FOG. FLOW MORE DISCRETE ACROSS IOWA INTO SOUTHERN WISCONSIN BEHIND EXITING MESOSCALE CONVECTIVE SYSTEM...WITH MAIN OUTFLOW NEARLY TO THE MISSOURI BORDER AT MOMENT. YOU HAVE TO GO TO SOUTHWEST IOWA TO FIND BREAKS IN CLOUDS BUT LOTS OF CLOUD DEBRIS UPSTREAM THAT MAY DAMPEN THREATS OF WARM SECTOR ADVANCING NORTH. DYNAMICS OF APPROACHING WAVE WILL CERTAINLY PROVIDE PUSH NORTH BUT THIS MIGHT MATERIALIZE AS WIDESPREAD CONVECTIVE DEVELOPMENT. WINDOW FOR STRONGER SUPERCELLS AND RELATED HIGHER SEVERE WEATHER RISK MAY BE NARROW AND AGAIN... FURTHER WEST OR SOUTHWEST OF AREA. WIDESPREAD SHOWER ACTIVITY WILL LIKELY HAVE EMBEDDED...FAST MOVING ELEVATED THUNDERSTORMS FROM LATE AFTERNOON INTO EVENING...WITH THREAT OF STRONGER TO SEVERE STORMS MOVING IN LATER IN EVENING IN DIMINISHING STATE. ALL IN ALL...LOTS OF UNCERTAINTIES BUT THREAT FOR ROUNDS OF HEAVY RAIN AND LIGHTNING STILL THERE. WILL CONTINUE TO MONITOR SEVERE WEATHER TRENDS AND IF NEEDED...TRANSITION PRODUCT SUITE TO LESS OF A RISK. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CDT FRI OCT 4 2013 MOST OF THE FORECAST WAS SPENT ON TRYING TO IMPROVE THE FORECAST TODAY THROUGH SATURDAY AND EVALUATING THE SEVERE WEATHER RISK. IT LOOKS LIKE THERE IS A RISK...BUT THE THREAT HAS DIMINISHED SOMEWHAT AND SHIFTED WEST. SURFACE ANALYSIS SHOWING COMPLEX YET FAIRLY ORGANIZED AIR MASS FRONTAL BOUNDARIES THIS MORNING. STALLED SURFACE BOUNDARY ORIENTED SW-NE ACROSS NE IA AND SWRN WI WITH SOME CAPE ALONG AND TO ITS SOUTH. MORE OF THE MARITIME TROPICAL AIR IS LOCATED SOUTH OF A WARM-STATIONARY FRONT IN THE VICINITY OF THE IA-MO BORDER...FEEDING WITH MUCH OF THE NOCTURNAL CONVECTION IN IA. MAIN SYNOPTIC SURFACE LOW ASSOCIATED WITH THE STRONG-DEEP TROPOSPHERIC SYSTEM OVER UTAH IS STILL LOCATED BACK IN WRN KS. WEAK PRESSURE FALLS OF 1MB/3HR CENTERED OVER NEBRASKA SUGGEST THE LOW CENTER SHOULD EJECT WEST OF OMAHA. 04.00Z NAM HAS THE BEST LOOKING SEA- LEVEL VERIFICATION AT 06Z. MID-UPPER LEVEL SYSTEM CENTERED OVER UT PER WATER VAPOR IMAGERY...WITH SIGNIFICANT POTENTIAL VORTICITY IN THE SRN MOST PART OF THE STATE WITH A TROP FOLD DOWN TO ABOUT 500MB. HAVE SOME CONCERNS WITH UPPER JET ENERGY ON NORTHWEST SIDE OF TROUGH WITH SPOKANE RAOB COMING IN WITH 130 KTS...WHICH 04.00Z GFS INITIALIZED BEST BUT STILL TOO WEAK...AND 110 KTS IN SRN B.C. NET EFFECT OF UNDER INITIALIZATION /10-15KTS/ WOULD BE TO HOLD THE MID-UPPER TROUGH ENERGY BACK IN THE SW U.S. AND EJECT THE SRN UT ENERGY SLIGHTLY FURTHER WEST THAN CURRENTLY FORECAST. WATER VAPOR ALSO YIELDING A FOOTPRINT OF A SHORTWAVE TROUGH SW OF OMAHA AT 05Z ENHANCING CONVECTION SHIFTING NORTHEAST. THIS WILL MOVE THROUGH THE FORECAST AREA. FOR THE MOST PART THE LATEST MODEL GUIDANCE PROVIDES SOME CONSENSUS ON THE NEXT DAYS. BUT THE DETAILS ON TIMING ARE STILL GOING TO BE DIFFICULT. LOOKING AT THE TRENDS IN THE MODELS...THE 12 HOUR TREND /12-18-00Z MODEL RUNS/ AT THE SURFACE IS FOR A SLOWER AND FURTHER SOUTHWEST POSITION TO THE SYNOPTIC FEATURES. THIS FAVORS A SURFACE LOW IN NERN NEB BY EARLY THIS EVENING...WITH THE SLOWLY NORTHWARD MOVING WARM FRONT JUST TO OUR SOUTH IN IA /VERSUS I-90/ AND THE FORECAST AREA IN SE-EASTERLY FLOW...COOLER THERMAL CONDITIONS ALL DAY FRIDAY NORTH OF THE WARM FRONT. WITH MUCH OF THE CAPE TIED TO THE WARM SECTOR...AND THE SLOWER TIMING INTO THE OVERNIGHT FOR THE WARM SECTOR ARRIVAL...THIS SHOULD DECREASE THE SEVERE WEATHER POTENTIAL ACROSS THE AREA...AT LEAST FOR TORNADOES AND LARGE HAIL AND DAMAGING WIND COVERAGE. IT APPEARS THE HIGHEST RISK IS FURTHER WEST/SOUTH THAN YESTERDAYS FORECAST. THIS MORNINGS SHORTWAVE TROUGH EAST OF KDSM AT 08Z LOOKS TO CONTINUE NORTHEAST THIS MORNING BRINGING RAIN NORTHWARD. MUCAPE ANALYSIS INDICATES ABOUT 500 J/KG FROM NE IA TO CENTRAL WI AND SOUTHEAST. PER THE LATEST WIND PROFILES...THE LOW-LEVEL JET IS CONVERGENT INTO SRN IA AND PER THE LATEST RAP FORECASTS...THAT THE STRONGER FORCING REMAINS /SRN IA/ UNTIL LATER WHEN IT STARTS TO SHIFT NORTH. HOWEVER...THE 04.07Z RAP NOW SUGGESTS A SLIGHT MOISTURE TRANSPORT SIGNAL MOVES NORTH WITH THE SHORTWAVE INTO CENTRAL WI. WEAK...BUT MAYBE ENOUGH TO KEEP SOME SHOWERS GOING INTO CENTRAL WI. HAVE DETAILED THE PRECIPITATION CHANCES FOR TODAY TO HAVE MINIMUM AROUND MID DAY AFTER MORNING RAINS...ESPECIALLY IN THE SOUTH. TODAY WITH BOUNDARY ACROSS THE FORECAST AREA AND THE SOUTHERN WARM FRONT MERGING TODAY...THERE IS PLENTY OF SOUTHEAST FLOW ACROSS THE SOUTH MAKING FOR LARGER CURVING HODOGRAPHS BY LATER AFTERNOON. HOWEVER...THE LOW-LEVEL WIND FIELD IS NOT CONVERGENT EXCEPT ON THE FRONT FURTHER SOUTH OF THE FORECAST AREA. THE AIR MASS SEEMS TO HAVE LITTLE CAP INDICATED IN THE FORECAST MODELS IN THE SOUTH AROUND MID-DAY. THUS...AS THE SYSTEM EJECTS FROM THE ROCKIES AND THE SOUTHERLY JET INCREASES...WIDESPREAD SHOWERS AND STORMS SHOULD DEVELOP IN ISENTROPIC LIFT AND A CONVERGENT LOW-LEVEL JET ACROSS NRN IA BY MID-LATE AFTERNOON. THIS BROAD LIFT AND LACK OF SURFACE CONVERGENCE IN THE FORECAST AREA SEEMS TO SUGGEST A BROAD AREA OF COMPETING STORMS WOULD USE THE AVAILABLE CAPE....NOT A SURFACE- BOUNDARY-FORCED CAP BREAKING EVENT WHICH WOULD FAVOR TORNADOES AND MORE SEVERE WEATHER. THUS...IT SEEMS EMBEDDED SEVERE STORMS WITH IN A BROADER HEAVY RAIN PRECIPITATION REGION SHOULD DEVELOP ACROSS THE SOUTH LATER THIS AFTERNOON. THE FORCING IS BEST WEST OF THE MISSISSIPPI RIVER. THE SPC MODERATE RISK HAS NOT EVOLVED WEST...EVEN THOUGH THE WEATHER SYSTEM SOLUTION HAS...TO FURTHER WEST AND SLOWER. WOULD THINK THE MODERATE RISK IS WEST OF THE FORECAST AREA. THE BEST THREAT FOR THE SEVERE STORMS LOOKS TO BE SOUTHWEST OF A DODGE CENTER MN TO BOSCOBEL WISCONSIN LINE...AND WILL CHANGE FORECAST PRODUCTS ACCORDINGLY. IT SEEMS THE LACK OF A GOOD SURFACE WARM FRONTAL BOUNDARY AND CONVERGENCE WILL FAVOR A BROAD CONVECTIVE MODE RATHER THAN SUPERCELLS...AND THUS A VERY REDUCED TORNADO THREAT. TONIGHT MAY PROVIDE A BETTER SEVERE THREAT AS THE COLD FRONT INITIATED CONVECTIVE LINE FROM WESTERN IA SHIFTS EAST AND ARRIVES IN THE LATE EVENING. FORCING AND DYNAMICS ARE STRONGER...BUT CAPE IS REALLY LOWERING IN THAT 03-06Z PERIOD...HOWEVER THE FORECAST AREA...ESPECIALLY I-90 AND SOUTH...SEEMS TO GET INTO A NARROW WARM SECTOR REGION. SO...BOWING WIND SEGMENTS OF CONVECTION ARE WITH WIND DAMAGE POSSIBLE. THIS IS A DIFFICULT FORECAST AS SOME STORMS/RAIN ARE EXPECTED ASSOCIATED WITH THE WARM FRONT FORCING IN THE HOURS PRIOR. THUS LATE EVENING AND OVERNIGHT CONVECTION MAY BE ALL DYNAMICS AND LITTLE CAPE. NORTH OF THE TRIPLE POINT...SERN MN INTO CENTRAL WI...HEAVY RAIN IN STRONGLY FORCED ISENTROPIC LIFT SEEMS TO BE A STRONG SIGNAL IN THE MODELS. THERE COULD BE LOCALIZED FLOODING THREATS THERE...DEPENDING ON RATES. THE SOILS SHOULD BE ABLE TO HANDLE A FEW INCHES IF IT DOESNT COME AT ONCE. WILL REISSUE AN ESF/DISCUSSION ON THIS RAIN POTENTIAL. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 337 AM CDT FRI OCT 4 2013 THE COLD FRONT IS MOVING THROUGH THE FORECAST AREA OVERNIGHT AND SATURDAY IT WILL BE FOUND IN CENTRAL WI AROUND MID-DAY. STORMS MAY INITIATE ON THE FRONT...BUT IT WOULD APPEAR THE BETTER SEVERE RISK WOULD BE EAST OF THE FORECAST AREA. SHOULD THE FRONT SLOW...INSTABILITY WOULD IN THE LOWER CATEGORY IN HIGH SHEAR...CAPABLE OF MINI-SUPERCELLS AND HAIL-WIND THREATS. SUNDAY CONTINUES TO BE COOL IN THE POST-FRONTAL ENVIRONMENT. THERE STILL APPEARS TO BE SOME TIMING AND INTENSITY DIFFERENCES WITH THE DEFORMATION BAND OF PRECIPITATION BEHIND THE DEPARTING LOW. HAVE DECIDED TO INCREASE PRECIPITATION CHANCES SUNDAY ESPECIALLY FURTHER NORTHWEST. MONDAY THROUGH THURSDAY...ANOTHER PERIOD OF ABOVE NORMAL FALL DAYS WITH A GOOD AMOUNT OF SUNSHINE AS LONG WAVE RIDGING AGAIN BUILDS IN. MODEL AGREEMENT AND CONFIDENCE IS HIGH FOR THIS PERIOD AS THE LONG WAVE TROUGH DIGS OVER THE SOUTHWEST U.S. WEATHER SHOULD BECOME MORE ACTIVE FOR THE WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON) ISSUED AT 1217 PM CDT FRI OCT 4 2013 BULK OF AREA SOCKED UNDER IFR TO LIFR CONDITIONS NORTH OF A BOUNDARY THAT LIES CLOSER TO HIGHWAY 20 IN IOWA. THESE CONDITIONS ARE NOT EXPECTED TO CHANGE MUCH IN THE SHORT TERM BUT AS DYNAMICS TAKE OVER WITH SIGNIFICANT UPPER LOW PROGRESSING INTO CENTRAL STATES... WIDESPREAD LIFT AND ASSOCIATED CONVECTION SHOULD REFORM TO THE SOUTHWEST AND SWEEP IN. HIGHEST RISK FOR CONVECTION IS IN EVENING HOURS AND INTO THE OVERNIGHT...WHERE VISIBILITIES COULD ACTUALLY IMPROVE A BIT UNDER THE RAIN. CEILINGS THOUGH WILL REMAIN LOW SIDE FOR POOR AVIATION WEATHER OVERALL. MAIN COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL BE SWEEPING THROUGH ON SATURDAY. BESIDES WIND SHIFT...EXPECT RAPIDLY IMPROVING CONDITIONS AS COOLER AND DRIER AIR SWEEPS IN. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE.......SHEA SHORT TERM...BAUMGARDT LONG TERM....BAUMGARDT AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1027 AM CDT FRI OCT 4 2013 .UPDATE...(SEVERE WEATHER RISK TODAY/TONIGHT) ISSUED AT 1027 AM CDT FRI OCT 4 2013 SETUP FOR LATER TODAY EVEN MORE MUDDLED WITH MAIN WARM FRONT SO FAR SOUTH AT MOMENT. TRENDS IN MESOSCALE GUIDANCE AND OBSERVATIONS SUGGEST...AS PREVIOUS FORECASTERS POINTED OUT...THAT HIGH RISK OF SEVERE WEATHER APPEARS TO BE SHIFTING WEST AND SOUTH. STORM PREDICTION CENTER GUIDANCE ALSO TRENDING THAT WAY AND WILL BE INTERESTING TO SEE WHAT LATER UPDATES PROGRESS TO. ALONG AND NORTH OF INTERSTATE 90...COOL FLOW NORTH OF BOUNDARY SEEMS TO BE WELL ESTABLISHED AND REINFORCING LOW CLOUDS AND FOG. FLOW MORE DISCRETE ACROSS IOWA INTO SOUTHERN WISCONSIN BEHIND EXITING MESOSCALE CONVECTIVE SYSTEM...WITH MAIN OUTFLOW NEARLY TO THE MISSOURI BORDER AT MOMENT. YOU HAVE TO GO TO SOUTHWEST IOWA TO FIND BREAKS IN CLOUDS BUT LOTS OF CLOUD DEBRIS UPSTREAM THAT MAY DAMPEN THREATS OF WARM SECTOR ADVANCING NORTH. DYNAMICS OF APPROACHING WAVE WILL CERTAINLY PROVIDE PUSH NORTH BUT THIS MIGHT MATERIALIZE AS WIDESPREAD CONVECTIVE DEVELOPMENT. WINDOW FOR STRONGER SUPERCELLS AND RELATED HIGHER SEVERE WEATHER RISK MAY BE NARROW AND AGAIN... FURTHER WEST OR SOUTHWEST OF AREA. WIDESPREAD SHOWER ACTIVITY WILL LIKELY HAVE EMBEDDED...FAST MOVING ELEVATED THUNDERSTORMS FROM LATE AFTERNOON INTO EVENING...WITH THREAT OF STRONGER TO SEVERE STORMS MOVING IN LATER IN EVENING IN DIMINISHING STATE. ALL IN ALL...LOTS OF UNCERTAINTIES BUT THREAT FOR ROUNDS OF HEAVY RAIN AND LIGHTNING STILL THERE. WILL CONTINUE TO MONITOR SEVERE WEATHER TRENDS AND IF NEEDED...TRANSITION PRODUCT SUITE TO LESS OF A RISK. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CDT FRI OCT 4 2013 MOST OF THE FORECAST WAS SPENT ON TRYING TO IMPROVE THE FORECAST TODAY THROUGH SATURDAY AND EVALUATING THE SEVERE WEATHER RISK. IT LOOKS LIKE THERE IS A RISK...BUT THE THREAT HAS DIMINISHED SOMEWHAT AND SHIFTED WEST. SURFACE ANALYSIS SHOWING COMPLEX YET FAIRLY ORGANIZED AIR MASS FRONTAL BOUNDARIES THIS MORNING. STALLED SURFACE BOUNDARY ORIENTED SW-NE ACROSS NE IA AND SWRN WI WITH SOME CAPE ALONG AND TO ITS SOUTH. MORE OF THE MARITIME TROPICAL AIR IS LOCATED SOUTH OF A WARM-STATIONARY FRONT IN THE VICINITY OF THE IA-MO BORDER...FEEDING WITH MUCH OF THE NOCTURNAL CONVECTION IN IA. MAIN SYNOPTIC SURFACE LOW ASSOCIATED WITH THE STRONG-DEEP TROPOSPHERIC SYSTEM OVER UTAH IS STILL LOCATED BACK IN WRN KS. WEAK PRESSURE FALLS OF 1MB/3HR CENTERED OVER NEBRASKA SUGGEST THE LOW CENTER SHOULD EJECT WEST OF OMAHA. 04.00Z NAM HAS THE BEST LOOKING SEA- LEVEL VERIFICATION AT 06Z. MID-UPPER LEVEL SYSTEM CENTERED OVER UT PER WATER VAPOR IMAGERY...WITH SIGNIFICANT POTENTIAL VORTICITY IN THE SRN MOST PART OF THE STATE WITH A TROP FOLD DOWN TO ABOUT 500MB. HAVE SOME CONCERNS WITH UPPER JET ENERGY ON NORTHWEST SIDE OF TROUGH WITH SPOKANE RAOB COMING IN WITH 130 KTS...WHICH 04.00Z GFS INITIALIZED BEST BUT STILL TOO WEAK...AND 110 KTS IN SRN B.C. NET EFFECT OF UNDER INITIALIZATION /10-15KTS/ WOULD BE TO HOLD THE MID-UPPER TROUGH ENERGY BACK IN THE SW U.S. AND EJECT THE SRN UT ENERGY SLIGHTLY FURTHER WEST THAN CURRENTLY FORECAST. WATER VAPOR ALSO YIELDING A FOOTPRINT OF A SHORTWAVE TROUGH SW OF OMAHA AT 05Z ENHANCING CONVECTION SHIFTING NORTHEAST. THIS WILL MOVE THROUGH THE FORECAST AREA. FOR THE MOST PART THE LATEST MODEL GUIDANCE PROVIDES SOME CONSENSUS ON THE NEXT DAYS. BUT THE DETAILS ON TIMING ARE STILL GOING TO BE DIFFICULT. LOOKING AT THE TRENDS IN THE MODELS...THE 12 HOUR TREND /12-18-00Z MODEL RUNS/ AT THE SURFACE IS FOR A SLOWER AND FURTHER SOUTHWEST POSITION TO THE SYNOPTIC FEATURES. THIS FAVORS A SURFACE LOW IN NERN NEB BY EARLY THIS EVENING...WITH THE SLOWLY NORTHWARD MOVING WARM FRONT JUST TO OUR SOUTH IN IA /VERSUS I-90/ AND THE FORECAST AREA IN SE-EASTERLY FLOW...COOLER THERMAL CONDITIONS ALL DAY FRIDAY NORTH OF THE WARM FRONT. WITH MUCH OF THE CAPE TIED TO THE WARM SECTOR...AND THE SLOWER TIMING INTO THE OVERNIGHT FOR THE WARM SECTOR ARRIVAL...THIS SHOULD DECREASE THE SEVERE WEATHER POTENTIAL ACROSS THE AREA...AT LEAST FOR TORNADOES AND LARGE HAIL AND DAMAGING WIND COVERAGE. IT APPEARS THE HIGHEST RISK IS FURTHER WEST/SOUTH THAN YESTERDAYS FORECAST. THIS MORNINGS SHORTWAVE TROUGH EAST OF KDSM AT 08Z LOOKS TO CONTINUE NORTHEAST THIS MORNING BRINGING RAIN NORTHWARD. MUCAPE ANALYSIS INDICATES ABOUT 500 J/KG FROM NE IA TO CENTRAL WI AND SOUTHEAST. PER THE LATEST WIND PROFILES...THE LOW-LEVEL JET IS CONVERGENT INTO SRN IA AND PER THE LATEST RAP FORECASTS...THAT THE STRONGER FORCING REMAINS /SRN IA/ UNTIL LATER WHEN IT STARTS TO SHIFT NORTH. HOWEVER...THE 04.07Z RAP NOW SUGGESTS A SLIGHT MOISTURE TRANSPORT SIGNAL MOVES NORTH WITH THE SHORTWAVE INTO CENTRAL WI. WEAK...BUT MAYBE ENOUGH TO KEEP SOME SHOWERS GOING INTO CENTRAL WI. HAVE DETAILED THE PRECIPITATION CHANCES FOR TODAY TO HAVE MINIMUM AROUND MID DAY AFTER MORNING RAINS...ESPECIALLY IN THE SOUTH. TODAY WITH BOUNDARY ACROSS THE FORECAST AREA AND THE SOUTHERN WARM FRONT MERGING TODAY...THERE IS PLENTY OF SOUTHEAST FLOW ACROSS THE SOUTH MAKING FOR LARGER CURVING HODOGRAPHS BY LATER AFTERNOON. HOWEVER...THE LOW-LEVEL WIND FIELD IS NOT CONVERGENT EXCEPT ON THE FRONT FURTHER SOUTH OF THE FORECAST AREA. THE AIR MASS SEEMS TO HAVE LITTLE CAP INDICATED IN THE FORECAST MODELS IN THE SOUTH AROUND MID-DAY. THUS...AS THE SYSTEM EJECTS FROM THE ROCKIES AND THE SOUTHERLY JET INCREASES...WIDESPREAD SHOWERS AND STORMS SHOULD DEVELOP IN ISENTROPIC LIFT AND A CONVERGENT LOW-LEVEL JET ACROSS NRN IA BY MID-LATE AFTERNOON. THIS BROAD LIFT AND LACK OF SURFACE CONVERGENCE IN THE FORECAST AREA SEEMS TO SUGGEST A BROAD AREA OF COMPETING STORMS WOULD USE THE AVAILABLE CAPE....NOT A SURFACE- BOUNDARY-FORCED CAP BREAKING EVENT WHICH WOULD FAVOR TORNADOES AND MORE SEVERE WEATHER. THUS...IT SEEMS EMBEDDED SEVERE STORMS WITH IN A BROADER HEAVY RAIN PRECIPITATION REGION SHOULD DEVELOP ACROSS THE SOUTH LATER THIS AFTERNOON. THE FORCING IS BEST WEST OF THE MISSISSIPPI RIVER. THE SPC MODERATE RISK HAS NOT EVOLVED WEST...EVEN THOUGH THE WEATHER SYSTEM SOLUTION HAS...TO FURTHER WEST AND SLOWER. WOULD THINK THE MODERATE RISK IS WEST OF THE FORECAST AREA. THE BEST THREAT FOR THE SEVERE STORMS LOOKS TO BE SOUTHWEST OF A DODGE CENTER MN TO BOSCOBEL WISCONSIN LINE...AND WILL CHANGE FORECAST PRODUCTS ACCORDINGLY. IT SEEMS THE LACK OF A GOOD SURFACE WARM FRONTAL BOUNDARY AND CONVERGENCE WILL FAVOR A BROAD CONVECTIVE MODE RATHER THAN SUPERCELLS...AND THUS A VERY REDUCED TORNADO THREAT. TONIGHT MAY PROVIDE A BETTER SEVERE THREAT AS THE COLD FRONT INITIATED CONVECTIVE LINE FROM WESTERN IA SHIFTS EAST AND ARRIVES IN THE LATE EVENING. FORCING AND DYNAMICS ARE STRONGER...BUT CAPE IS REALLY LOWERING IN THAT 03-06Z PERIOD...HOWEVER THE FORECAST AREA...ESPECIALLY I-90 AND SOUTH...SEEMS TO GET INTO A NARROW WARM SECTOR REGION. SO...BOWING WIND SEGMENTS OF CONVECTION ARE WITH WIND DAMAGE POSSIBLE. THIS IS A DIFFICULT FORECAST AS SOME STORMS/RAIN ARE EXPECTED ASSOCIATED WITH THE WARM FRONT FORCING IN THE HOURS PRIOR. THUS LATE EVENING AND OVERNIGHT CONVECTION MAY BE ALL DYNAMICS AND LITTLE CAPE. NORTH OF THE TRIPLE POINT...SERN MN INTO CENTRAL WI...HEAVY RAIN IN STRONGLY FORCED ISENTROPIC LIFT SEEMS TO BE A STRONG SIGNAL IN THE MODELS. THERE COULD BE LOCALIZED FLOODING THREATS THERE...DEPENDING ON RATES. THE SOILS SHOULD BE ABLE TO HANDLE A FEW INCHES IF IT DOESNT COME AT ONCE. WILL REISSUE AN ESF/DISCUSSION ON THIS RAIN POTENTIAL. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 337 AM CDT FRI OCT 4 2013 THE COLD FRONT IS MOVING THROUGH THE FORECAST AREA OVERNIGHT AND SATURDAY IT WILL BE FOUND IN CENTRAL WI AROUND MID-DAY. STORMS MAY INITIATE ON THE FRONT...BUT IT WOULD APPEAR THE BETTER SEVERE RISK WOULD BE EAST OF THE FORECAST AREA. SHOULD THE FRONT SLOW...INSTABILITY WOULD IN THE LOWER CATEGORY IN HIGH SHEAR...CAPABLE OF MINI-SUPERCELLS AND HAIL-WIND THREATS. SUNDAY CONTINUES TO BE COOL IN THE POST-FRONTAL ENVIRONMENT. THERE STILL APPEARS TO BE SOME TIMING AND INTENSITY DIFFERENCES WITH THE DEFORMATION BAND OF PRECIPITATION BEHIND THE DEPARTING LOW. HAVE DECIDED TO INCREASE PRECIPITATION CHANCES SUNDAY ESPECIALLY FURTHER NORTHWEST. MONDAY THROUGH THURSDAY...ANOTHER PERIOD OF ABOVE NORMAL FALL DAYS WITH A GOOD AMOUNT OF SUNSHINE AS LONG WAVE RIDGING AGAIN BUILDS IN. MODEL AGREEMENT AND CONFIDENCE IS HIGH FOR THIS PERIOD AS THE LONG WAVE TROUGH DIGS OVER THE SOUTHWEST U.S. WEATHER SHOULD BECOME MORE ACTIVE FOR THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 625 AM CDT FRI OCT 4 2013 ABUNDANT LOW LEVEL MOISTURE OVER THE AREA COMBINED WITH INCREASING LIFT AHEAD OF A STRONG MID LEVEL TROUGH AND APPROACHING SFC LOW LOOKS TO PRODUCE AN EXTENDED PERIOD OF IFR/MVFR FOR THE AREA TODAY THRU SAT. A FRONTAL BOUNDARY PUSHED SOUTH OF THE AREA LATE THU...AND APPEARS AS THOUGH IT WILL STAY SOUTH OF THE AREA THRU TONIGHT. IF THE FRONT DOES STAY SOUTH OF THE AREA...THIS WILL LIMIT THE POTENTIAL OF SEVERE STORMS THIS AFTERNOON/EVENING. NORTH OF THIS BOUNDARY...LOW STRATUS AND BR/FG WILL PREVAIL MUCH OF TODAY/ TONIGHT. INCREASING LIFT AHEAD OF THE APPROACHING SYSTEM WILL SEND ROUNDS OF SHRA/TSRA ACROSS THE TAF SITES TODAY/TONIGHT. ONE OF THESE WILL MOVE ACROSS THE AREA THIS MORNING...WITH ANOTHER ROUND EXPECTED TO DEVELOP NORTH OF THE FRONTAL BOUNDARY ACROSS CENTRAL IA AND MOVE ACROSS THE AREA THIS AFTERNOON/EVENING. YET ANOTHER ROUND LATER TONIGHT AS THE SFC LOW MOVES INTO MN AND THE COLD FRONT APPROACHES. GIVEN PLENTY OF DETAIL AND TIMING UNCERTAINTIES BEYOND THIS MORNING...GENERALLY CARRIED VCSH/VCTS IN THE TAFS VS. LONGER PERIODS OF SHRA/TSRA. BR/LOW STRATUS WILL GENERALLY KEEP FLIGHT CATEGORIES IFR/MVFR WITH OR WITHOUT SHRA/TSRA...THOUGH SHRA/TSRA PASSING THU MAY ACTUALLY RAISE THE CIGS/VSBYS. LATER TAF CYCLES OR UPDATES CAN ADD MORE SHRA/TSRA WHEN TIMING DETAILS BECOME CLEARER. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
625 AM CDT FRI OCT 4 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CDT FRI OCT 4 2013 MOST OF THE FORECAST WAS SPENT ON TRYING TO IMPROVE THE FORECAST TODAY THROUGH SATURDAY AND EVALUATING THE SEVERE WEATHER RISK. IT LOOKS LIKE THERE IS A RISK...BUT THE THREAT HAS DIMINISHED SOMEWHAT AND SHIFTED WEST. SURFACE ANALYSIS SHOWING COMPLEX YET FAIRLY ORGANIZED AIR MASS FRONTAL BOUNDARIES THIS MORNING. STALLED SURFACE BOUNDARY ORIENTED SW-NE ACROSS NE IA AND SWRN WI WITH SOME CAPE ALONG AND TO ITS SOUTH. MORE OF THE MARITIME TROPICAL AIR IS LOCATED SOUTH OF A WARM-STATIONARY FRONT IN THE VICINITY OF THE IA-MO BORDER...FEEDING WITH MUCH OF THE NOCTURNAL CONVECTION IN IA. MAIN SYNOPTIC SURFACE LOW ASSOCIATED WITH THE STRONG-DEEP TROPOSPHERIC SYSTEM OVER UTAH IS STILL LOCATED BACK IN WRN KS. WEAK PRESSURE FALLS OF 1MB/3HR CENTERED OVER NEBRASKA SUGGEST THE LOW CENTER SHOULD EJECT WEST OF OMAHA. 04.00Z NAM HAS THE BEST LOOKING SEA- LEVEL VERIFICATION AT 06Z. MID-UPPER LEVEL SYSTEM CENTERED OVER UT PER WATER VAPOR IMAGERY...WITH SIGNIFICANT POTENTIAL VORTICITY IN THE SRN MOST PART OF THE STATE WITH A TROP FOLD DOWN TO ABOUT 500MB. HAVE SOME CONCERNS WITH UPPER JET ENERGY ON NORTHWEST SIDE OF TROUGH WITH SPOKANE RAOB COMING IN WITH 130 KTS...WHICH 04.00Z GFS INITIALIZED BEST BUT STILL TOO WEAK...AND 110 KTS IN SRN B.C. NET EFFECT OF UNDER INITIALIZATION /10-15KTS/ WOULD BE TO HOLD THE MID-UPPER TROUGH ENERGY BACK IN THE SW U.S. AND EJECT THE SRN UT ENERGY SLIGHTLY FURTHER WEST THAN CURRENTLY FORECAST. WATER VAPOR ALSO YIELDING A FOOTPRINT OF A SHORTWAVE TROUGH SW OF OMAHA AT 05Z ENHANCING CONVECTION SHIFTING NORTHEAST. THIS WILL MOVE THROUGH THE FORECAST AREA. FOR THE MOST PART THE LATEST MODEL GUIDANCE PROVIDES SOME CONSENSUS ON THE NEXT DAYS. BUT THE DETAILS ON TIMING ARE STILL GOING TO BE DIFFICULT. LOOKING AT THE TRENDS IN THE MODELS...THE 12 HOUR TREND /12-18-00Z MODEL RUNS/ AT THE SURFACE IS FOR A SLOWER AND FURTHER SOUTHWEST POSITION TO THE SYNOPTIC FEATURES. THIS FAVORS A SURFACE LOW IN NERN NEB BY EARLY THIS EVENING...WITH THE SLOWLY NORTHWARD MOVING WARM FRONT JUST TO OUR SOUTH IN IA /VERSUS I-90/ AND THE FORECAST AREA IN SE-EASTERLY FLOW...COOLER THERMAL CONDITIONS ALL DAY FRIDAY NORTH OF THE WARM FRONT. WITH MUCH OF THE CAPE TIED TO THE WARM SECTOR...AND THE SLOWER TIMING INTO THE OVERNIGHT FOR THE WARM SECTOR ARRIVAL...THIS SHOULD DECREASE THE SEVERE WEATHER POTENTIAL ACROSS THE AREA...AT LEAST FOR TORNADOES AND LARGE HAIL AND DAMAGING WIND COVERAGE. IT APPEARS THE HIGHEST RISK IS FURTHER WEST/SOUTH THAN YESTERDAYS FORECAST. THIS MORNINGS SHORTWAVE TROUGH EAST OF KDSM AT 08Z LOOKS TO CONTINUE NORTHEAST THIS MORNING BRINGING RAIN NORTHWARD. MUCAPE ANALYSIS INDICATES ABOUT 500 J/KG FROM NE IA TO CENTRAL WI AND SOUTHEAST. PER THE LATEST WIND PROFILES...THE LOW-LEVEL JET IS CONVERGENT INTO SRN IA AND PER THE LATEST RAP FORECASTS...THAT THE STRONGER FORCING REMAINS /SRN IA/ UNTIL LATER WHEN IT STARTS TO SHIFT NORTH. HOWEVER...THE 04.07Z RAP NOW SUGGESTS A SLIGHT MOISTURE TRANSPORT SIGNAL MOVES NORTH WITH THE SHORTWAVE INTO CENTRAL WI. WEAK...BUT MAYBE ENOUGH TO KEEP SOME SHOWERS GOING INTO CENTRAL WI. HAVE DETAILED THE PRECIPITATION CHANCES FOR TODAY TO HAVE MINIMUM AROUND MID DAY AFTER MORNING RAINS...ESPECIALLY IN THE SOUTH. TODAY WITH BOUNDARY ACROSS THE FORECAST AREA AND THE SOUTHERN WARM FRONT MERGING TODAY...THERE IS PLENTY OF SOUTHEAST FLOW ACROSS THE SOUTH MAKING FOR LARGER CURVING HODOGRAPHS BY LATER AFTERNOON. HOWEVER...THE LOW-LEVEL WIND FIELD IS NOT CONVERGENT EXCEPT ON THE FRONT FURTHER SOUTH OF THE FORECAST AREA. THE AIR MASS SEEMS TO HAVE LITTLE CAP INDICATED IN THE FORECAST MODELS IN THE SOUTH AROUND MID-DAY. THUS...AS THE SYSTEM EJECTS FROM THE ROCKIES AND THE SOUTHERLY JET INCREASES...WIDESPREAD SHOWERS AND STORMS SHOULD DEVELOP IN ISENTROPIC LIFT AND A CONVERGENT LOW-LEVEL JET ACROSS NRN IA BY MID-LATE AFTERNOON. THIS BROAD LIFT AND LACK OF SURFACE CONVERGENCE IN THE FORECAST AREA SEEMS TO SUGGEST A BROAD AREA OF COMPETING STORMS WOULD USE THE AVAILABLE CAPE....NOT A SURFACE- BOUNDARY-FORCED CAP BREAKING EVENT WHICH WOULD FAVOR TORNADOES AND MORE SEVERE WEATHER. THUS...IT SEEMS EMBEDDED SEVERE STORMS WITH IN A BROADER HEAVY RAIN PRECIPITATION REGION SHOULD DEVELOP ACROSS THE SOUTH LATER THIS AFTERNOON. THE FORCING IS BEST WEST OF THE MISSISSIPPI RIVER. THE SPC MODERATE RISK HAS NOT EVOLVED WEST...EVEN THOUGH THE WEATHER SYSTEM SOLUTION HAS...TO FURTHER WEST AND SLOWER. WOULD THINK THE MODERATE RISK IS WEST OF THE FORECAST AREA. THE BEST THREAT FOR THE SEVERE STORMS LOOKS TO BE SOUTHWEST OF A DODGE CENTER MN TO BOSCOBEL WISCONSIN LINE...AND WILL CHANGE FORECAST PRODUCTS ACCORDINGLY. IT SEEMS THE LACK OF A GOOD SURFACE WARM FRONTAL BOUNDARY AND CONVERGENCE WILL FAVOR A BROAD CONVECTIVE MODE RATHER THAN SUPERCELLS...AND THUS A VERY REDUCED TORNADO THREAT. TONIGHT MAY PROVIDE A BETTER SEVERE THREAT AS THE COLD FRONT INITIATED CONVECTIVE LINE FROM WESTERN IA SHIFTS EAST AND ARRIVES IN THE LATE EVENING. FORCING AND DYNAMICS ARE STRONGER...BUT CAPE IS REALLY LOWERING IN THAT 03-06Z PERIOD...HOWEVER THE FORECAST AREA...ESPECIALLY I-90 AND SOUTH...SEEMS TO GET INTO A NARROW WARM SECTOR REGION. SO...BOWING WIND SEGMENTS OF CONVECTION ARE WITH WIND DAMAGE POSSIBLE. THIS IS A DIFFICULT FORECAST AS SOME STORMS/RAIN ARE EXPECTED ASSOCIATED WITH THE WARM FRONT FORCING IN THE HOURS PRIOR. THUS LATE EVENING AND OVERNIGHT CONVECTION MAY BE ALL DYNAMICS AND LITTLE CAPE. NORTH OF THE TRIPLE POINT...SERN MN INTO CENTRAL WI...HEAVY RAIN IN STRONGLY FORCED ISENTROPIC LIFT SEEMS TO BE A STRONG SIGNAL IN THE MODELS. THERE COULD BE LOCALIZED FLOODING THREATS THERE...DEPENDING ON RATES. THE SOILS SHOULD BE ABLE TO HANDLE A FEW INCHES IF IT DOESNT COME AT ONCE. WILL REISSUE AN ESF/DISCUSSION ON THIS RAIN POTENTIAL. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 337 AM CDT FRI OCT 4 2013 THE COLD FRONT IS MOVING THROUGH THE FORECAST AREA OVERNIGHT AND SATURDAY IT WILL BE FOUND IN CENTRAL WI AROUND MID-DAY. STORMS MAY INITIATE ON THE FRONT...BUT IT WOULD APPEAR THE BETTER SEVERE RISK WOULD BE EAST OF THE FORECAST AREA. SHOULD THE FRONT SLOW...INSTABILITY WOULD IN THE LOWER CATEGORY IN HIGH SHEAR...CAPABLE OF MINI-SUPERCELLS AND HAIL-WIND THREATS. SUNDAY CONTINUES TO BE COOL IN THE POST-FRONTAL ENVIRONMENT. THERE STILL APPEARS TO BE SOME TIMING AND INTENSITY DIFFERENCES WITH THE DEFORMATION BAND OF PRECIPITATION BEHIND THE DEPARTING LOW. HAVE DECIDED TO INCREASE PRECIPITATION CHANCES SUNDAY ESPECIALLY FURTHER NORTHWEST. MONDAY THROUGH THURSDAY...ANOTHER PERIOD OF ABOVE NORMAL FALL DAYS WITH A GOOD AMOUNT OF SUNSHINE AS LONG WAVE RIDGING AGAIN BUILDS IN. MODEL AGREEMENT AND CONFIDENCE IS HIGH FOR THIS PERIOD AS THE LONG WAVE TROUGH DIGS OVER THE SOUTHWEST U.S. WEATHER SHOULD BECOME MORE ACTIVE FOR THE WEEKEND. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING) ISSUED AT 625 AM CDT FRI OCT 4 2013 ABUNDANT LOW LEVEL MOISTURE OVER THE AREA COMBINED WITH INCREASING LIFT AHEAD OF A STRONG MID LEVEL TROUGH AND APPROACHING SFC LOW LOOKS TO PRODUCE AN EXTENDED PERIOD OF IFR/MVFR FOR THE AREA TODAY THRU SAT. A FRONTAL BOUNDARY PUSHED SOUTH OF THE AREA LATE THU...AND APPEARS AS THOUGH IT WILL STAY SOUTH OF THE AREA THRU TONIGHT. IF THE FRONT DOES STAY SOUTH OF THE AREA...THIS WILL LIMIT THE POTENTIAL OF SEVERE STORMS THIS AFTERNOON/EVENING. NORTH OF THIS BOUNDARY...LOW STRATUS AND BR/FG WILL PREVAIL MUCH OF TODAY/ TONIGHT. INCREASING LIFT AHEAD OF THE APPROACHING SYSTEM WILL SEND ROUNDS OF SHRA/TSRA ACROSS THE TAF SITES TODAY/TONIGHT. ONE OF THESE WILL MOVE ACROSS THE AREA THIS MORNING...WITH ANOTHER ROUND EXPECTED TO DEVELOP NORTH OF THE FRONTAL BOUNDARY ACROSS CENTRAL IA AND MOVE ACROSS THE AREA THIS AFTERNOON/EVENING. YET ANOTHER ROUND LATER TONIGHT AS THE SFC LOW MOVES INTO MN AND THE COLD FRONT APPROACHES. GIVEN PLENTY OF DETAIL AND TIMING UNCERTAINTIES BEYOND THIS MORNING...GENERALLY CARRIED VCSH/VCTS IN THE TAFS VS. LONGER PERIODS OF SHRA/TSRA. BR/LOW STRATUS WILL GENERALLY KEEP FLIGHT CATEGORIES IFR/MVFR WITH OR WITHOUT SHRA/TSRA...THOUGH SHRA/TSRA PASSING THU MAY ACTUALLY RAISE THE CIGS/VSBYS. LATER TAF CYCLES OR UPDATES CAN ADD MORE SHRA/TSRA WHEN TIMING DETAILS BECOME CLEARER. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
338 AM CDT FRI OCT 4 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 337 AM CDT FRI OCT 4 2013 MOST OF THE FORECAST WAS SPENT ON TRYING TO IMPROVE THE FORECAST TODAY THROUGH SATURDAY AND EVALUATING THE SEVERE WEATHER RISK. IT LOOKS LIKE THERE IS A RISK...BUT THE THREAT HAS DIMINISHED SOMEWHAT AND SHIFTED WEST. SURFACE ANALYSIS SHOWING COMPLEX YET FAIRLY ORGANIZED AIR MASS FRONTAL BOUNDARIES THIS MORNING. STALLED SURFACE BOUNDARY ORIENTED SW-NE ACROSS NE IA AND SWRN WI WITH SOME CAPE ALONG AND TO ITS SOUTH. MORE OF THE MARITIME TROPICAL AIR IS LOCATED SOUTH OF A WARM-STATIONARY FRONT IN THE VICINITY OF THE IA-MO BORDER...FEEDING WITH MUCH OF THE NOCTURNAL CONVECTION IN IA. MAIN SYNOPTIC SURFACE LOW ASSOCIATED WITH THE STRONG-DEEP TROPOSPHERIC SYSTEM OVER UTAH IS STILL LOCATED BACK IN WRN KS. WEAK PRESSURE FALLS OF 1MB/3HR CENTERED OVER NEBRASKA SUGGEST THE LOW CENTER SHOULD EJECT WEST OF OMAHA. 04.00Z NAM HAS THE BEST LOOKING SEA- LEVEL VERIFICATION AT 06Z. MID-UPPER LEVEL SYSTEM CENTERED OVER UT PER WATER VAPOR IMAGERY...WITH SIGNIFICANT POTENTIAL VORTICITY IN THE SRN MOST PART OF THE STATE WITH A TROP FOLD DOWN TO ABOUT 500MB. HAVE SOME CONCERNS WITH UPPER JET ENERGY ON NORTHWEST SIDE OF TROUGH WITH SPOKANE RAOB COMING IN WITH 130 KTS...WHICH 04.00Z GFS INITIALIZED BEST BUT STILL TOO WEAK...AND 110 KTS IN SRN B.C. NET EFFECT OF UNDER INITIALIZATION /10-15KTS/ WOULD BE TO HOLD THE MID-UPPER TROUGH ENERGY BACK IN THE SW U.S. AND EJECT THE SRN UT ENERGY SLIGHTLY FURTHER WEST THAN CURRENTLY FORECAST. WATER VAPOR ALSO YIELDING A FOOTPRINT OF A SHORTWAVE TROUGH SW OF OMAHA AT 05Z ENHANCING CONVECTION SHIFTING NORTHEAST. THIS WILL MOVE THROUGH THE FORECAST AREA. FOR THE MOST PART THE LATEST MODEL GUIDANCE PROVIDES SOME CONSENSUS ON THE NEXT DAYS. BUT THE DETAILS ON TIMING ARE STILL GOING TO BE DIFFICULT. LOOKING AT THE TRENDS IN THE MODELS...THE 12 HOUR TREND /12-18-00Z MODEL RUNS/ AT THE SURFACE IS FOR A SLOWER AND FURTHER SOUTHWEST POSITION TO THE SYNOPTIC FEATURES. THIS FAVORS A SURFACE LOW IN NERN NEB BY EARLY THIS EVENING...WITH THE SLOWLY NORTHWARD MOVING WARM FRONT JUST TO OUR SOUTH IN IA /VERSUS I-90/ AND THE FORECAST AREA IN SE-EASTERLY FLOW...COOLER THERMAL CONDITIONS ALL DAY FRIDAY NORTH OF THE WARM FRONT. WITH MUCH OF THE CAPE TIED TO THE WARM SECTOR...AND THE SLOWER TIMING INTO THE OVERNIGHT FOR THE WARM SECTOR ARRIVAL...THIS SHOULD DECREASE THE SEVERE WEATHER POTENTIAL ACROSS THE AREA...AT LEAST FOR TORNADOES AND LARGE HAIL AND DAMAGING WIND COVERAGE. IT APPEARS THE HIGHEST RISK IS FURTHER WEST/SOUTH THAN YESTERDAYS FORECAST. THIS MORNINGS SHORTWAVE TROUGH EAST OF KDSM AT 08Z LOOKS TO CONTINUE NORTHEAST THIS MORNING BRINGING RAIN NORTHWARD. MUCAPE ANALYSIS INDICATES ABOUT 500 J/KG FROM NE IA TO CENTRAL WI AND SOUTHEAST. PER THE LATEST WIND PROFILES...THE LOW-LEVEL JET IS CONVERGENT INTO SRN IA AND PER THE LATEST RAP FORECASTS...THAT THE STRONGER FORCING REMAINS /SRN IA/ UNTIL LATER WHEN IT STARTS TO SHIFT NORTH. HOWEVER...THE 04.07Z RAP NOW SUGGESTS A SLIGHT MOISTURE TRANSPORT SIGNAL MOVES NORTH WITH THE SHORTWAVE INTO CENTRAL WI. WEAK...BUT MAYBE ENOUGH TO KEEP SOME SHOWERS GOING INTO CENTRAL WI. HAVE DETAILED THE PRECIPITATION CHANCES FOR TODAY TO HAVE MINIMUM AROUND MID DAY AFTER MORNING RAINS...ESPECIALLY IN THE SOUTH. TODAY WITH BOUNDARY ACROSS THE FORECAST AREA AND THE SOUTHERN WARM FRONT MERGING TODAY...THERE IS PLENTY OF SOUTHEAST FLOW ACROSS THE SOUTH MAKING FOR LARGER CURVING HODOGRAPHS BY LATER AFTERNOON. HOWEVER...THE LOW-LEVEL WIND FIELD IS NOT CONVERGENT EXCEPT ON THE FRONT FURTHER SOUTH OF THE FORECAST AREA. THE AIR MASS SEEMS TO HAVE LITTLE CAP INDICATED IN THE FORECAST MODELS IN THE SOUTH AROUND MID-DAY. THUS...AS THE SYSTEM EJECTS FROM THE ROCKIES AND THE SOUTHERLY JET INCREASES...WIDESPREAD SHOWERS AND STORMS SHOULD DEVELOP IN ISENTROPIC LIFT AND A CONVERGENT LOW-LEVEL JET ACROSS NRN IA BY MID-LATE AFTERNOON. THIS BROAD LIFT AND LACK OF SURFACE CONVERGENCE IN THE FORECAST AREA SEEMS TO SUGGEST A BROAD AREA OF COMPETING STORMS WOULD USE THE AVAILABLE CAPE....NOT A SURFACE- BOUNDARY-FORCED CAP BREAKING EVENT WHICH WOULD FAVOR TORNADOES AND MORE SEVERE WEATHER. THUS...IT SEEMS EMBEDDED SEVERE STORMS WITH IN A BROADER HEAVY RAIN PRECIPITATION REGION SHOULD DEVELOP ACROSS THE SOUTH LATER THIS AFTERNOON. THE FORCING IS BEST WEST OF THE MISSISSIPPI RIVER. THE SPC MODERATE RISK HAS NOT EVOLVED WEST...EVEN THOUGH THE WEATHER SYSTEM SOLUTION HAS...TO FURTHER WEST AND SLOWER. WOULD THINK THE MODERATE RISK IS WEST OF THE FORECAST AREA. THE BEST THREAT FOR THE SEVERE STORMS LOOKS TO BE SOUTHWEST OF A DODGE CENTER MN TO BOSCOBEL WISCONSIN LINE...AND WILL CHANGE FORECAST PRODUCTS ACCORDINGLY. IT SEEMS THE LACK OF A GOOD SURFACE WARM FRONTAL BOUNDARY AND CONVERGENCE WILL FAVOR A BROAD CONVECTIVE MODE RATHER THAN SUPERCELLS...AND THUS A VERY REDUCED TORNADO THREAT. TONIGHT MAY PROVIDE A BETTER SEVERE THREAT AS THE COLD FRONT INITIATED CONVECTIVE LINE FROM WESTERN IA SHIFTS EAST AND ARRIVES IN THE LATE EVENING. FORCING AND DYNAMICS ARE STRONGER...BUT CAPE IS REALLY LOWERING IN THAT 03-06Z PERIOD...HOWEVER THE FORECAST AREA...ESPECIALLY I-90 AND SOUTH...SEEMS TO GET INTO A NARROW WARM SECTOR REGION. SO...BOWING WIND SEGMENTS OF CONVECTION ARE WITH WIND DAMAGE POSSIBLE. THIS IS A DIFFICULT FORECAST AS SOME STORMS/RAIN ARE EXPECTED ASSOCIATED WITH THE WARM FRONT FORCING IN THE HOURS PRIOR. THUS LATE EVENING AND OVERNIGHT CONVECTION MAY BE ALL DYNAMICS AND LITTLE CAPE. NORTH OF THE TRIPLE POINT...SERN MN INTO CENTRAL WI...HEAVY RAIN IN STRONGLY FORCED ISENTROPIC LIFT SEEMS TO BE A STRONG SIGNAL IN THE MODELS. THERE COULD BE LOCALIZED FLOODING THREATS THERE...DEPENDING ON RATES. THE SOILS SHOULD BE ABLE TO HANDLE A FEW INCHES IF IT DOESNT COME AT ONCE. WILL REISSUE AN ESF/DISCUSSION ON THIS RAIN POTENTIAL. .LONG TERM...(SATURDAY THROUGH THURSDAY) ISSUED AT 337 AM CDT FRI OCT 4 2013 THE COLD FRONT IS MOVING THROUGH THE FORECAST AREA OVERNIGHT AND SATURDAY IT WILL BE FOUND IN CENTRAL WI AROUND MID-DAY. STORMS MAY INITIATE ON THE FRONT...BUT IT WOULD APPEAR THE BETTER SEVERE RISK WOULD BE EAST OF THE FORECAST AREA. SHOULD THE FRONT SLOW...INSTABILITY WOULD IN THE LOWER CATEGORY IN HIGH SHEAR...CAPABLE OF MINI-SUPERCELLS AND HAIL-WIND THREATS. SUNDAY CONTINUES TO BE COOL IN THE POST-FRONTAL ENVIRONMENT. THERE STILL APPEARS TO BE SOME TIMING AND INTENSITY DIFFERENCES WITH THE DEFORMATION BAND OF PRECIPITATION BEHIND THE DEPARTING LOW. HAVE DECIDED TO INCREASE PRECIPITATION CHANCES SUNDAY ESPECIALLY FURTHER NORTHWEST. MONDAY THROUGH THURSDAY...ANOTHER PERIOD OF ABOVE NORMAL FALL DAYS WITH A GOOD AMOUNT OF SUNSHINE AS LONG WAVE RIDGING AGAIN BUILDS IN. MODEL AGREEMENT AND CONFIDENCE IS HIGH FOR THIS PERIOD AS THE LONG WAVE TROUGH DIGS OVER THE SOUTHWEST U.S. WEATHER SHOULD BECOME MORE ACTIVE FOR THE WEEKEND. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1131 PM CDT THU OCT 3 2013 WITH THE MAIN BOUNDARY NOW SOUTH OF BOTH TAF SITES THE CONCERN FOR THE OVERNIGHT HAS SHIFTED TO IFR CONDITIONS DUE TO FOG AND CEILINGS. THE FOG HAS SETTLED IN OVER KRST AND INDICATIONS ARE THAT IT WILL REMAIN FOR THE NIGHT WITH LITTLE TO NO TEMP/DEW POINT SPREAD AND ONLY LIGHT NORTH WINDS. THE 04.02Z RAP FORECAST SOUNDINGS SHOW NO SIGNIFICANT CHANGES OCCURRING OVERNIGHT SO WILL LEAVE THE LIFR CONDITIONS IN PLACE UNTIL THE MIDDLE OF FRIDAY MORNING WHEN SOME IMPROVEMENT COULD OCCUR IF THE CONVECTION OVER SOUTHWEST IOWA CAN MOVE INTO THE AREA AND CLEAN THE ATMOSPHERE OUT. FOG HAS YET TO DEVELOP IN THE MISSISSIPPI RIVER VALLEY BUT THE LOW CEILINGS ARE IN PLACE. HOWEVER...WITH ONLY A 2 DEGREE TEMP/DEW POINT SPREAD AT 04Z...EXPECT TO SEE THE FOG FORM WITH THE VISIBILITY GOING DOWN TO IFR OVERNIGHT. CONSIDERABLE UNCERTAINTY STILL EXISTS ON HOW FRIDAY WILL PLAY OUT IN THE AFTERNOON AND EVENING. THE 04.00Z NAM SUGGESTS THE BOUNDARY WILL STAY SOUTH OF BOTH TAF SITES THROUGH THE EVENING AS THE MAIN SURFACE LOW MOVES INTO SOUTHEAST SOUTH DAKOTA OR SOUTHWEST MINNESOTA. IT DOES SUGGEST THAT A LEAD SHORT WAVE TROUGH COULD TRACK OVER THE AREA DURING THE AFTERNOON AND EVENING TO SPARK CONVECTION ALONG AND NORTH OF THE BOUNDARY SO HAVE INCLUDED VCTS AT BOTH SITES TO HAND THIS. OTHERWISE...THE BEST CHANCE FOR CONVECTION MAY NOT OCCUR UNTIL LATE FRIDAY EVENING INTO THE OVERNIGHT HOURS AS THE COLD FRONT APPROACHES FROM THE WEST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1131 PM CDT THU OCT 3 2013 .UPDATE... ISSUED AT 747 PM CDT THU OCT 3 2013 THE MAIN SURFACE BOUNDARY HAS BEEN SLIPPING SLOWLY SOUTH THROUGH THE AREA THIS EVENING AND NOW EXTENDS FROM ABOUT KDLL TO KIFA. TRENDS IN THE HRRR HAVE BEEN FOR THE BOUNDARY TO CONTINUE SLIPPING TO THE SOUTH AS IT BECOMES ORIENTED A LITTLE MORE EAST/WEST EVENTUALLY SETTLING IN OVER THE FAR SOUTHERN PARTS OF THE FORECAST AREA OR A LITTLE FARTHER SOUTH AND THEN REMAIN THERE IN FRIDAY MORNING. A WEAK SHORT WAVE TROUGH IS COMING ACROSS NEBRASKA AND KANSAS THAT WILL INITIATE CONVECTION ALONG THE BOUNDARY AS THE LOW LEVEL JET GETS CRANKED UP. SIGNS OF THIS STARTING TO OCCUR OVER SOUTHERN IOWA AND THIS SHOULD THEN MOVE NORTHEAST ALONG THE BOUNDARY GIVING THE BEST CHANCE FOR ADDITIONAL SHOWERS AND STORMS OVERNIGHT ACROSS THE SOUTH. HAVE ALREADY ADJUSTED THE RAIN CHANCES TO SHOW THE HIGHEST CHANCES ACROSS THE SOUTH FOR THE OVERNIGHT. FURTHER ADJUSTMENTS MAY BE MADE TO LIMIT THE THUNDER CHANCES TO THE SOUTH AS WELL AND POSSIBLY GO TO MORE A DRIZZLE EVENT NORTH OF THE BOUNDARY. FOG ALSO DEVELOPING NORTH OF THE BOUNDARY AND WILL HAVE TO MONITOR THE POSSIBLE DEVELOPMENT OF DENSE FOG. && .SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 356 PM CDT THU OCT 3 2013 MAIN FORECAST CONCERNS ARE ON SEVERE THUNDERSTORM POTENTIAL FRIDAY INTO FRIDAY NIGHT WITH THE POSSIBILITY OF HEAVY RAIN...LARGE HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES. LATEST WATER VAPOR IMAGERY SHOWED SEVERAL SHORTWAVE MOVING ACROSS THE UPPER MIDWEST. THE LEADING SHORTWAVE WAS MOVING OVER THE FORECAST AREA THIS AFTERNOON...PRODUCING SHOWERS AND THUNDERSTORMS. THE MAIN FEATURE TO KEY IN ON IS A POTENT UPPER LOW DIGGING INTO THE CENTRAL ROCKIES. THIS FEATURE WILL EJECT EASTWARD INTO THE PLAINS DRIVING A SURFACE LOW AND WARM FRONT INTO THE REGION FRIDAY INTO FRIDAY NIGHT. MEANWHILE...SURFACE OBSERVATIONS SHOWED A VERY MOIST AIRMASS SURGING INTO THE FORECAST AREA WITH DEWPOINTS CLIMBING INTO UPPER 60S ACROSS ALL OF NORTHEAST IOWA AND SOUTHWEST WISCONSIN. SHOWER AND THUNDERSTORMS SHOULD GRADUALLY MOVE NORTHEAST...IMPACTING CENTRAL AND NORTH CENTRAL WISCONSIN LATE THIS AFTERNOON INTO EARLY THIS EVENING THEN TAPERING OFF. ANOTHER ROUND OF SHOWER AND STORMS ARE EXPECTED TO REDEVELOP TONIGHT AS A STRONG LOW LEVEL JET FOCUSES INTO AREAS ALONG AND SOUTH OF INTERSTATE 90...POSSIBLY IMPACTING MOST AREAS SOUTH AND WEST OF THE INTERSTATE 94 CORRIDOR. ANY STORMS THAT DEVELOP TONIGHT WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL WITH PRECIPITABLE WATER VALUES 1.4 TO 1.6 INCHES...WHICH IS RIGHT AROUND 200 PERCENT OF NORMAL. IN ADDITION...WARM CLOUD DEPTHS HOVER AROUND 3.5 KM. WILL HAVE TO KEEP A VERY CLOSE WATCH ON RAINFALL AMOUNTS TONIGHT...ESPECIALLY ACROSS AREAS THAT RECEIVED HEAVIER RAINS TODAY. CANNOT RULE OUT SOME SMALL TO POSSIBLY LARGE HAIL TONIGHT WITH THE SOME OF THE STRONGER STORMS...WITH 0-3KM MUCAPE VALUES CLIMBING TO AROUND 1500 J/KG LATE TONIGHT. FOCUS QUICKLY TURNS TO FRIDAY AS A WARM FRONT LIFTS INTO THE REGION AND SURFACE LOW PRESSURE DEEPENS OVER NORTHEAST NEBRASKA AND LIFTS INTO SOUTHWEST MINNESOTA. A WARM FRONT SHOULD BE SET UP FROM NORTHWEST IOWA THROUGH NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN BY EARLY FRIDAY AFTERNOON. SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER NORTHWEST IOWA/SOUTHWEST MINNESOTA BY MID AFTERNOON AND WILL RACE EAST INTO THE FORECAST AREA DURING THE LATE AFTERNOON AND EVENING HOURS. ALSO...CANNOT RULE OUT A STORM OR TWO DEVELOPING IN THE WARM SECTOR FURTHER EAST OVER NORTHEAST IOWA AND SOUTHWEST WISCONSIN. THESE STORMS WOULD LIKELY BE SUPERCELLS...WITH 0-6 KM BULK SHEAR VALUES OF 40 TO 45 KTS. INTERESTING TO NOTE THAT MUCH OF THIS SHEAR IS LOCATED IN THE 0-3 KM LAYER. THE SUPERCELLS COULD FORM INTO BOWS AS THEY RACE EAST WITH AN ENHANCED THREAT FOR DAMAGING WINDS AND PERHAPS AN EMBEDDED TORNADO OR TWO. THE WARM FRONT LIFTS NORTH TO ALONG THE INTERSTATE 90 CORRIDOR BY EARLY FRIDAY EVENING. THE BEST PARAMETERS FOR TORNADOES APPEARS TO BE WEST OF THE MISSISSIPPI RIVER IN THE 21Z TO 4Z TIMEFRAME...THEN SHIFTING NORTHEAST. ONE OF THE BIGGEST CONCERNS IS THE RAPID INCREASE IN 0-1KM BULK SHEAR IN THE 00Z TO 03Z TIMEFRAME WHEN VALUES GO FROM 20 TO 25KTS TO AROUND 40 KTS. AS THE STORMS WORK EAST THEY WILL BE ENCOUNTERING THIS STRONGER LOWER LEVEL SHEAR. THE STORMS SHOULD PUSH TO ALONG THE MISSISSIPPI RIVER IN THE LATE EVENING TO LATE NIGHT HOURS. THE STORMS WILL THEN PUSH INTO WESTERN WISCONSIN AND MAY STILL BE SEVERE WITH DAMAGING WINDS...LARGE HAIL...AND ISOLATED TORNADOES. THE VERY MOIST AIRMASS WILL REMAIN IN PLACE FRIDAY NIGHT AND COULD LEAD TO THE POTENTIAL FOR HEAVY RAIN AND POSSIBLY SOME LOCALIZED FLOODING CONCERNS. A FLASH FLOOD WATCH MAY BE NEEDED. THE COLD FRONT LOOKS TO PUSH THROUGH THE FORECAST AREA LATE FRIDAY NIGHT INTO SATURDAY MORNING. .LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 356 PM CDT THU OCT 3 2013 SHOWERS AND STORMS WILL LIKELY BE ONGOING SATURDAY MORNING. ANOTHER ROUND OF STRONG TO POSSIBLY SEVERE STORM COULD OCCUR OVER WESTERN AN CENTRAL WISCONSIN EARLY SATURDAY AFTERNOON BUT THIS WILL DEPEND ON THE TIMING OF THE COLD FRONT. THE LOW PRESSURE SYSTEM THEN FINALLY LIFTS NORTHEAST OF THE AREA SATURDAY NIGHT INTO SUNDAY. MUCH OF THE AREA WILL LIKELY BE DRY SLOTTED SATURDAY NIGHT INTO EARLY SUNDAY MORNING. WRAP AROUND MOISTURE ON THE BACK SIDE OF THE LOW COULD BRING SOME SHOWERS TO THE AREA ON SUNDAY. MUCH COOLER AIR WILL MOVE INTO THE REGION SATURDAY NIGHT WITH TEMPERATURES FALLING INTO THE UPPER 30S TO LOWER 40S. HIGHS ON SUNDAY WILL ONLY BE IN THE 50S. HIGH PRESSURE LOOKS TO BUILD OVER THE REGION MONDAY AND REMAINS OVER THE AREA THROUGH THURSDAY. DRY WEATHER IS EXPECTED THROUGH THE PERIOD WITH HIGHS WARMING INTO THE 60S ON MONDAY AND TUESDAY. HIGHS WARM INTO THE 70S ON WEDNESDAY AND THURSDAY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT 1131 PM CDT THU OCT 3 2013 WITH THE MAIN BOUNDARY NOW SOUTH OF BOTH TAF SITES THE CONCERN FOR THE OVERNIGHT HAS SHIFTED TO IFR CONDITIONS DUE TO FOG AND CEILINGS. THE FOG HAS SETTLED IN OVER KRST AND INDICATIONS ARE THAT IT WILL REMAIN FOR THE NIGHT WITH LITTLE TO NO TEMP/DEW POINT SPREAD AND ONLY LIGHT NORTH WINDS. THE 04.02Z RAP FORECAST SOUNDINGS SHOW NO SIGNIFICANT CHANGES OCCURRING OVERNIGHT SO WILL LEAVE THE LIFR CONDITIONS IN PLACE UNTIL THE MIDDLE OF FRIDAY MORNING WHEN SOME IMPROVEMENT COULD OCCUR IF THE CONVECTION OVER SOUTHWEST IOWA CAN MOVE INTO THE AREA AND CLEAN THE ATMOSPHERE OUT. FOG HAS YET TO DEVELOP IN THE MISSISSIPPI RIVER VALLEY BUT THE LOW CEILINGS ARE IN PLACE. HOWEVER...WITH ONLY A 2 DEGREE TEMP/DEW POINT SPREAD AT 04Z...EXPECT TO SEE THE FOG FORM WITH THE VISIBILITY GOING DOWN TO IFR OVERNIGHT. CONSIDERABLE UNCERTAINTY STILL EXISTS ON HOW FRIDAY WILL PLAY OUT IN THE AFTERNOON AND EVENING. THE 04.00Z NAM SUGGESTS THE BOUNDARY WILL STAY SOUTH OF BOTH TAF SITES THROUGH THE EVENING AS THE MAIN SURFACE LOW MOVES INTO SOUTHEAST SOUTH DAKOTA OR SOUTHWEST MINNESOTA. IT DOES SUGGEST THAT A LEAD SHORT WAVE TROUGH COULD TRACK OVER THE AREA DURING THE AFTERNOON AND EVENING TO SPARK CONVECTION ALONG AND NORTH OF THE BOUNDARY SO HAVE INCLUDED VCTS AT BOTH SITES TO HAND THIS. OTHERWISE...THE BEST CHANCE FOR CONVECTION MAY NOT OCCUR UNTIL LATE FRIDAY EVENING INTO THE OVERNIGHT HOURS AS THE COLD FRONT APPROACHES FROM THE WEST. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ UPDATE...04 SHORT TERM...WETENKAMP LONG TERM...WETENKAMP AVIATION...04
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
555 AM EDT SUN OCT 6 2013 .SYNOPSIS... ISSUED AT 356 AM EDT SUN OCT 6 2013 A COLD FRONT WILL CROSS THE REGION TODAY WITH WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS. HEAVY RAINFALL WILL BE POSSIBLE ALONG AND EAST OF I-69. THE CHANCE OF SHOWERS WILL THEN CONTINUE INTO TOMORROW WITH MUCH COLDER AIR ARRIVING FOR EARLY NEXT WEEK. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 356 AM EDT SUN OCT 6 2013 LATEST WATER VAPOR LOOP SHOWS CENTRAL CONUS "BOWLING BALL" OF VERY STRONG VORTICITY IS CURRENTLY ENTERING IOWA AND SLOWLY PROGRESSING EASTWARD. CORRESPONDINGLY...THE EASTERN EDGE OF MERIDIONAL 100+ KT UPPER LEVEL JET IS ENTERING EASTERN ILLINOIS WITH THE BAND OF ENHANCED 925-850MB FGEN ENTERING NORTHWEST INDIANA. TIGHTENING OF LOW LEVEL HEIGHT GRADIENT HAS ALSO SUPPORTED THE DEVELOPMENT OF A 50 KT LLJ CURRENTLY SURGING NORTHWARD THROUGH CENTRAL INDIANA. STRONG MOISTURE FLUX CONVERGENCE ON THE NOSE OF THIS JET IS LEADING TO AN INCREASE IN BOTH COVERAGE AND INTENSITY OF RAINFALL LOCALLY. WIDESPREAD SHOWERS AND THUNDERSTORMS ALSO BEING SUPPORTED BY GOOD 305K ISENTROPIC ASCENT AHEAD OF THE COLD FRONT AND SEVERAL SMALL SCALE...CONVECTIVELY INDUCED...VORTICITY MAXIMA LIFTING NORTH THROUGH THE REGION. LATEST BUFR SOUNDINGS AND RAP MESOANALYSIS ALSO SHOW A FEW HUNDRED J/KG OF ELEVATED INSTABILITY...NOT ENOUGH FOR SEVERE WEATHER CONCERNS BUT THE ADDED BUOYANCY IS FURTHER AIDING UVM`S IN AN ALREADY RESPECTABLE REGION OF SYNOPTIC FORCING. MOISTURE QUALITY IS EXCELLENT...BY OCTOBER STANDARDS ANYWAY...WITH PW VALUES HOVERING AROUND 1.75 INCHES. LOW CAPE DENSITY AND HIGH FREEZING LEVELS/DEEP WARM CLOUD LAYER ARE ALSO PROMOTING HIGHLY EFFICIENT WARM RAIN PROCESSES AND MEAN FLOW ALOFT NEARLY PARALLEL TO THE FRONT RAISES THE CONCERN FOR TRAINING OF STORMS AND POTENTIALLY HEAVY RAINFALL. ONLY FLY IN THE OINTMENT IS FASTER SYSTEM SPEED NOTED IN PREVIOUS DISCUSSION. 00Z NWP SUITE CONTINUES TO SHOW MORE PHASING WITH THE TROUGH DIVING INTO CENTRAL ONTARIO AND A QUICKER EXIT OF STRONG FRONTAL PRECIP LOCALLY. LATEST SURFACE OBSERVATIONS EVEN SHOW THE COLD FRONT IS ALREADY CLOSING IN ON OUR WESTERN COUNTIES. STILL EXPECT A FAIR AMOUNT OF RAINFALL...ESPECIALLY IN OUR EASTERN COUNTIES...BUT THE LIKELIHOOD OF PRODIGIOUS AMOUNTS SUGGESTED BY SOME OF LAST NIGHTS MODEL RUNS HAS DECREASED. NAM12 IS STILL SHOWING SOME HINTS OF SURFACE WAVE DEVELOPMENT ALONG THE FRONT LATER THIS EVENING BUT IS MUCH MORE PROGRESSIVE THAN LAST NIGHT AND KEEPS THE LONGEST DURATION/HEAVIEST RAINFALL IN THE FAR EASTERN EDGES OF OUR CWA. MEANWHILE OUR WESTERN COUNTIES WILL ONLY SEE A BRIEF SHOT AT RAINFALL THIS MORNING...LIKELY ENDING AROUND MIDDAY...AND SEVERELY LIMITING ADDITIONAL RAINFALL TOTALS. PRECIP WILL CONTINUE IN OUR EASTERN COUNTIES THROUGH THE EVENING AND GIVEN THE AFOREMENTIONED INGREDIENTS FOR HEAVY RAINFALL THERE IS STILL THE POTENTIAL FOR AN ADDITIONAL 1-2 INCHES EAST OF I-69. GIVEN SOME AREAS OF NORTHWEST OHIO HAVE ALREADY SEEN 1-3 INCHES OF RAIN OVER THE PAST 36 HOURS...INHERITED FLASH FLOOD WATCH STILL LOOKS GOOD AND NO CHANGES NECESSARY AT THE MOMENT. LATER SHIFTS MAY BE ABLE TO CANCEL THE WATCH EARLY GIVEN FASTER EXIT OF PRECIP AND LOWER QPF TOTALS. WITH REGARD TO THE SEVERE WEATHER POTENTIAL...FASTER FRONTAL PASSAGE AND COPIOUS PREFRONTAL CLOUDS/PRECIP WILL SEVERELY LIMIT ANY DIURNAL GAIN IN INSTABILITY. MODELS SUGGEST 1000 J/KG AT BEST...CONFINED TO OUR OHIO COUNTIES WITH GENERALLY MOIST ADIABATIC LAPSE RATES ALOFT. VERY STRONG LOW LEVEL WIND/SHEAR PROFILES DO RAISE THE CONCERN FOR DAMAGING WIND GUSTS AND POSSIBLE TORNADOES BUT STABLE ENVIRONMENT WILL BE A SIGNIFICANT LIMITING FACTOR AND EXPECT JUST A SLIGHT CHANCE FOR SEVERE WEATHER...AND ONLY IN OUR OHIO COUNTIES. AIRMASS BEHIND COLD FRONT IS NOT PARTICULARLY COLD BY OCTOBER STANDARDS BUT IS QUITE A BIT COOLER THAN WHAT WE HAVE EXPERIENCED RECENTLY. CAA WILL GRADUALLY SEND 850MB TEMPS BACK INTO THE MID...AND EVENTUALLY LOW...SINGLE DIGITS. THUS EXPECT DAYTIME HIGHS TO REMAIN SIMILAR TO CURRENT VALUES. COLDER AIR WILL SPILL INTO THE CWA BY LATE AFTERNOON AND TEMPS WILL GRADUALLY DROP INTO THE MID TO UPPER 40S BY TONIGHT. MIDLEVEL DRY SLOT MAY BRING A TEMPORARY END TO PRECIP FROM WEST-EAST BY LATER TODAY BUT EXPECT THERE WILL STILL BE A FAIR AMOUNT OF LOW CLOUDS THROUGH THE OVERNIGHT WITH PERHAPS SOME LIGHT...DEFORMATION-FORCED PRECIP RETURNING BY THE EARLY MORNING HOURS. && .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 356 AM EDT SUN OCT 6 2013 INTENSE CLOSED LOW OVR WRN IA WILL SWING EWD ACRS THE GREAT LAKES SHRT TERM AND OPEN UP ON MON AS IT ACCELERATE NEWD THROUGH THE ST LAW VALLEY. LINGERING SHRA XPCD ESP NORTH WITHIN RESIDUAL BUT RAPIDLY WKNG TROWAL/DEFORMATION ZONE AS COLD POCKET ALOFT CROSSES OVERHEAD MON MORNING. OTRWS SFC RIDGE BLDS EWD OUT OF THE ROCKIES IN THIS SYS/S WAKE W/SEASONABLY COOL TEMPS TO START THE WORKWEEK BUT MODERATING TO BACK ABV NORMAL BY WED AS DOWNSTREAM RIDGING DVLPS IN EARNEST IN RESPONSE TO RENEWED DEEP WRN TROUGH DVLPMNT. THIS NXT SYS XPCD TO LIFT OUT WELL WWD OF WRN GREAT LAKES W/DRY WX XPCD LOCALLY THROUGH AT LEAST DY7 (SAT). && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 555 AM EDT SUN OCT 6 2013 LATEST SURFACE ANALYSIS SHOWS COLD FRONT SLOWLY APPROACHING KSBN. NUMEROUS SHOWERS ARE EXPECTED TO CONTINUE THROUGH THE MORNING AS THIS FRONT PASSES. AN ISOLATED THUNDERSTORM REMAINS POSSIBLE BUT THE CHANCES ARE TOO LOW...AND THE TIMING IS TOO UNCERTAIN...FOR INCLUSION IN THE TAF AT THIS TIME. IFR CONDITIONS WILL ALSO REMAIN POSSIBLE UNTIL THE FRONT CLEARS AND DRIER AIR OVER ILLINOIS ADVECTS INTO THE AREA. IMPROVING CONDITIONS MAY ARRIVE EARLIER THAN PRESENTLY IN THE TAFS...AS THE FRONT IS MOVING QUICKER THAN PREVIOUS MODEL RUNS INDICATED...AND WILL ADJUST THE TIMING A BIT WITH THE 12Z ISSUANCE. VFR CONDITIONS EXPECTED TO RETURN BY THE AFTERNOON AND PERSIST THROUGH THE END OF THE PERIOD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR INZ007-009-018-026- 027-033-034. MI...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MIZ081. OH...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR OHZ001-002-004-005- 015-016-024-025. LM...NONE. && $$ SYNOPSIS...AGD SHORT TERM...AGD LONG TERM...T AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
356 AM EDT SUN OCT 6 2013 .SYNOPSIS... ISSUED AT 356 AM EDT SUN OCT 6 2013 A COLD FRONT WILL CROSS THE REGION TODAY WITH WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS. HEAVY RAINFALL WILL BE POSSIBLE ALONG AND EAST OF I-69. THE CHANCE OF SHOWERS WILL THEN CONTINUE INTO TOMORROW WITH MUCH COLDER AIR ARRIVING FOR EARLY NEXT WEEK. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 356 AM EDT SUN OCT 6 2013 LATEST WATER VAPOR LOOP SHOWS CENTRAL CONUS "BOWLING BALL" OF VERY STRONG VORTICITY IS CURRENTLY ENTERING IOWA AND SLOWLY PROGRESSING EASTWARD. CORRESPONDINGLY...THE EASTERN EDGE OF MERIDIONAL 100+ KT UPPER LEVEL JET IS ENTERING EASTERN ILLINOIS WITH THE BAND OF ENHANCED 925-850MB FGEN ENTERING NORTHWEST INDIANA. TIGHTENING OF LOW LEVEL HEIGHT GRADIENT HAS ALSO SUPPORTED THE DEVELOPMENT OF A 50 KT LLJ CURRENTLY SURGING NORTHWARD THROUGH CENTRAL INDIANA. STRONG MOISTURE FLUX CONVERGENCE ON THE NOSE OF THIS JET IS LEADING TO AN INCREASE IN BOTH COVERAGE AND INTENSITY OF RAINFALL LOCALLY. WIDESPREAD SHOWERS AND THUNDERSTORMS ALSO BEING SUPPORTED BY GOOD 305K ISENTROPIC ASCENT AHEAD OF THE COLD FRONT AND SEVERAL SMALL SCALE...CONVECTIVELY INDUCED...VORTICITY MAXIMA LIFTING NORTH THROUGH THE REGION. LATEST BUFR SOUNDINGS AND RAP MESOANALYSIS ALSO SHOW A FEW HUNDRED J/KG OF ELEVATED INSTABILITY...NOT ENOUGH FOR SEVERE WEATHER CONCERNS BUT THE ADDED BUOYANCY IS FURTHER AIDING UVM`S IN AN ALREADY RESPECTABLE REGION OF SYNOPTIC FORCING. MOISTURE QUALITY IS EXCELLENT...BY OCTOBER STANDARDS ANYWAY...WITH PW VALUES HOVERING AROUND 1.75 INCHES. LOW CAPE DENSITY AND HIGH FREEZING LEVELS/DEEP WARM CLOUD LAYER ARE ALSO PROMOTING HIGHLY EFFICIENT WARM RAIN PROCESSES AND MEAN FLOW ALOFT NEARLY PARALLEL TO THE FRONT RAISES THE CONCERN FOR TRAINING OF STORMS AND POTENTIALLY HEAVY RAINFALL. ONLY FLY IN THE OINTMENT IS FASTER SYSTEM SPEED NOTED IN PREVIOUS DISCUSSION. 00Z NWP SUITE CONTINUES TO SHOW MORE PHASING WITH THE TROUGH DIVING INTO CENTRAL ONTARIO AND A QUICKER EXIT OF STRONG FRONTAL PRECIP LOCALLY. LATEST SURFACE OBSERVATIONS EVEN SHOW THE COLD FRONT IS ALREADY CLOSING IN ON OUR WESTERN COUNTIES. STILL EXPECT A FAIR AMOUNT OF RAINFALL...ESPECIALLY IN OUR EASTERN COUNTIES...BUT THE LIKELIHOOD OF PRODIGIOUS AMOUNTS SUGGESTED BY SOME OF LAST NIGHTS MODEL RUNS HAS DECREASED. NAM12 IS STILL SHOWING SOME HINTS OF SURFACE WAVE DEVELOPMENT ALONG THE FRONT LATER THIS EVENING BUT IS MUCH MORE PROGRESSIVE THAN LAST NIGHT AND KEEPS THE LONGEST DURATION/HEAVIEST RAINFALL IN THE FAR EASTERN EDGES OF OUR CWA. MEANWHILE OUR WESTERN COUNTIES WILL ONLY SEE A BRIEF SHOT AT RAINFALL THIS MORNING...LIKELY ENDING AROUND MIDDAY...AND SEVERELY LIMITING ADDITIONAL RAINFALL TOTALS. PRECIP WILL CONTINUE IN OUR EASTERN COUNTIES THROUGH THE EVENING AND GIVEN THE AFOREMENTIONED INGREDIENTS FOR HEAVY RAINFALL THERE IS STILL THE POTENTIAL FOR AN ADDITIONAL 1-2 INCHES EAST OF I-69. GIVEN SOME AREAS OF NORTHWEST OHIO HAVE ALREADY SEEN 1-3 INCHES OF RAIN OVER THE PAST 36 HOURS...INHERITED FLASH FLOOD WATCH STILL LOOKS GOOD AND NO CHANGES NECESSARY AT THE MOMENT. LATER SHIFTS MAY BE ABLE TO CANCEL THE WATCH EARLY GIVEN FASTER EXIT OF PRECIP AND LOWER QPF TOTALS. WITH REGARD TO THE SEVERE WEATHER POTENTIAL...FASTER FRONTAL PASSAGE AND COPIOUS PREFRONTAL CLOUDS/PRECIP WILL SEVERELY LIMIT ANY DIURNAL GAIN IN INSTABILITY. MODELS SUGGEST 1000 J/KG AT BEST...CONFINED TO OUR OHIO COUNTIES WITH GENERALLY MOIST ADIABATIC LAPSE RATES ALOFT. VERY STRONG LOW LEVEL WIND/SHEAR PROFILES DO RAISE THE CONCERN FOR DAMAGING WIND GUSTS AND POSSIBLE TORNADOES BUT STABLE ENVIRONMENT WILL BE A SIGNIFICANT LIMITING FACTOR AND EXPECT JUST A SLIGHT CHANCE FOR SEVERE WEATHER...AND ONLY IN OUR OHIO COUNTIES. AIRMASS BEHIND COLD FRONT IS NOT PARTICULARLY COLD BY OCTOBER STANDARDS BUT IS QUITE A BIT COOLER THAN WHAT WE HAVE EXPERIENCED RECENTLY. CAA WILL GRADUALLY SEND 850MB TEMPS BACK INTO THE MID...AND EVENTUALLY LOW...SINGLE DIGITS. THUS EXPECT DAYTIME HIGHS TO REMAIN SIMILAR TO CURRENT VALUES. COLDER AIR WILL SPILL INTO THE CWA BY LATE AFTERNOON AND TEMPS WILL GRADUALLY DROP INTO THE MID TO UPPER 40S BY TONIGHT. MIDLEVEL DRY SLOT MAY BRING A TEMPORARY END TO PRECIP FROM WEST-EAST BY LATER TODAY BUT EXPECT THERE WILL STILL BE A FAIR AMOUNT OF LOW CLOUDS THROUGH THE OVERNIGHT WITH PERHAPS SOME LIGHT...DEFORMATION-FORCED PRECIP RETURNING BY THE EARLY MORNING HOURS. && .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 356 AM EDT SUN OCT 6 2013 INTENSE CLOSED LOW OVR WRN IA WILL SWING EWD ACRS THE GREAT LAKES SHRT TERM AND OPEN UP ON MON AS IT ACCELERATE NEWD THROUGH THE ST LAW VALLEY. LINGERING SHRA XPCD ESP NORTH WITHIN RESIDUAL BUT RAPIDLY WKNG TROWAL/DEFORMATION ZONE AS COLD POCKET ALOFT CROSSES OVERHEAD MON MORNING. OTRWS SFC RIDGE BLDS EWD OUT OF THE ROCKIES IN THIS SYS/S WAKE W/SEASONABLY COOL TEMPS TO START THE WORKWEEK BUT MODERATING TO BACK ABV NORMAL BY WED AS DOWNSTREAM RIDGING DVLPS IN EARNEST IN RESPONSE TO RENEWED DEEP WRN TROUGH DVLPMNT. THIS NXT SYS XPCD TO LIFT OUT WELL WWD OF WRN GREAT LAKES W/DRY WX XPCD LOCALLY THROUGH AT LEAST DY7 (SAT). && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 136 AM EDT SUN OCT 6 2013 LLJ AND ASSOCIATED REGION OF HEAVY RAIN/EMBEDDED THUNDERSTORMS WILL CONTINUE TO MOVE NORTH ACROSS INDIANA THROUGH THE MORNING HOURS. THIS ACTIVITY WILL MAINLY IMPACT KFWA BUT UPSTREAM OBSERVATIONS NEAR KSBN ALSO SHOW IFR/LIFR CEILINGS THAT WILL LIKELY IMPACT THE TERMINAL LATER THIS MORNING DESPITE LIGHTER RAINFALL. CONFIDENCE IN THUNDER AT KFWA REMAINS LOW AS THE BEST FORCING/INSTABILITY MAY BE SHUNTED JUST TO THE SOUTHEAST BUT WILL LEAVE TEMPO MENTION FOR NOW. PERIODIC THUNDERSTORMS...AND IFR CONDITIONS...WILL ALSO BE POSSIBLE AT KFWA THROUGHOUT THE DAY AS COLD FRONT DOES NOT FULLY CROSS THE AREA UNTIL LATE AFTERNOON. DRY SLOT CURRENTLY OVER WESTERN ILLINOIS WILL THEN BRING VFR CONDITIONS FOR THE REST OF THE PERIOD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR INZ007-009-018-026- 027-033-034. MI...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MIZ081. OH...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR OHZ001-002-004-005- 015-016-024-025. LM...NONE. && $$ SYNOPSIS...AGD SHORT TERM...AGD LONG TERM...T AVIATION...AGD VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1154 PM CDT Sat Oct 5 2013 ...Update to aviation forecast discussion... .UPDATE... Issued at 1029 PM CDT SAT OCT 5 2013 Have updated the overnight forecast primarily for the addition of sprinkles across northern Kansas, mainly after midnight. The upper low will track toward the southeast overnight and light shower activity currently over central and eastern Nebraska will make their way southeast into northern Kansas. Do not expect anything measurable at this time. Temperatures have been tracking fairly well, and while a reinforcing shot of cold air is working its way into Kansas this evening, it is accompanied by cloud cover and continued winds/mixing. All of this together should keep overnight lows around the 40 degree mark, with a few upper 30s possible. In the odd event that temps fall below 38, wind should help prevent any frost development. && .SHORT TERM...(This Evening through Sunday) Issued at 320 PM CDT SAT OCT 5 2013 20Z water vapor imagery shows the closed upper low over southeast SD slowly propagating east. A shortwave trough axis has rotated through eastern KS helping to clear out the mid level clouds. At the surface the cold front had pushed well east and south with dry cool air advecting in from the west. For tonight and Sunday, the forecast calls for generally dry weather as there is little moisture to work with and large scale forcing should remain to the north and east of the forecast area. Did leave some slight chance pops in the far northeastern corner of the forecast area during the day Sunday. As the upper low drifts across southwest IA, lapse rates could steepen enough for some isolated showers to move across Nemaha and Brown counties. The main thing to watch will be the STRATOCU deck to the north. The RAP and NAM show these clouds eventually moving into much of the forecast area overnight. This should have an impact on MIN and MAX temps. Models are in good agreement that the boundary layer will remain well mixed overnight with increasing clouds from the north. Therefore am fairly confident that MIN temps will not fall below 40 and even tweaks temps up a degree or two. The forecast may still be on the cool side if the clouds move in quicker. Highs Sunday are expected to warm back into the 60s for most areas. Forecast soundings mix the boundary layer almost to 800MB and models indicate the cold air advection will have ended. The main question is whether clouds will hold temps down. Added about 3 to 5 degrees to MAX temps across the western and southern counties where there should be more insolation with good mixing. Across northeastern KS where clouds are likely to hang in tough, kept highs in the middle 50s. Wolters .LONG TERM...(Sunday Night through Saturday) Issued at 320 PM CDT SAT OCT 5 2013 Upper low still on track to progress eastward through the mid MO and OH river valleys through Monday. Most of the moisture wrapping around the backside of the exiting upper may linger across the far northeast corner of the cwa early Sunday evening...so have left a slight chance in for that time period. Otherwise will go with a dry fcst Monday through Thursday night as upper level ridging will develop across the plains in the wake of the first trough exiting trough and ahead of the second upper trough that deepens over the west CONUS. Will continue to slowly but steadily increase high temps through the 70s Monday through Thursday...with a few low 80s on Thursday. As the western trough then lift out into the plains on Friday and Friday night...with more clouds and the potential for showers and thunderstorms cooled temps slightly for Friday before the frontal passage and and even cooler readings in the low to middle 70s on Saturday. Warmed low temps from near 40 Monday morning into the 50s by Wednesday on through the end of the week. && .AVIATION...(For the 06Z TAFs through 06Z Sunday Night) Issued at 1152 PM CDT SAT OCT 5 2013 TAF beings VFR but with increasing clouds in the 3k to 4k foot range. Have increasing confidence that MVFR ceilings will develop at all TAF sites, likely in the 09Z to 11Z time frame, and persisting through approximately 15Z before lifting above 3k feet. Winds will be gusty after 15Z with gusts in the 24 to 30 kt range. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barjenbruch SHORT TERM...Wolters LONG TERM...63 AVIATION...Barjenbruch
AREA FORECAST DISCUSSION
NWS DULUTH MN
1243 AM CDT SUN OCT 6 2013 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 319 PM CDT SAT OCT 5 2013 STACKED LOW PRESSURE OVER SOUTHEAST SOUTH DAKOTA WILL MOVE EAST/SOUTHEAST TONIGHT...ALTHOUGH THE SURFACE LOW IS FORECAST TO MOVE TOWARD UPPER MICHIGAN TONIGHT. AS THE SURFACE LOW NEARS THE NORTHLAND LATER TONIGHT...WINDS SHOULD GRADUALLY SUBSIDE. WE CONTINUE TO GET GUSTS OF 35 TO 45 MPH AT THE HEAD OF LAKE SUPERIOR...AND WE`LL EXTEND THE WIND ADVISORY FOR DOUGLAS...SOUTHERN SAINT LOUIS...CARLTON...AND SOUTHERN LAKE COUNTIES UNTIL 10 PM. THE STRONGEST WINDS WILL REMAIN WILL BE CLOSE TO LAKE SUPERIOR. RAIN WAS DEVELOPING ACROSS PORTIONS OF CENTRAL/SOUTHEAST MINNESOTA SIMILAR TO WHAT THE MODELS INCLUDING THE HRRR WERE DEPICTING. WE SHOULD CONTINUE TO SEE RAIN DEVELOP AND MOVE NORTH THROUGH THE NORTHLAND THIS EVENING/OVERNIGHT...BECOMING WIDESPREAD. WE`VE SEEN A FEW LIGHTNING STRIKES CLOSE TO THE AREA...SO ADDED A SLIGHT CHANCE FOR A STORM TO ALL AREAS LATE THIS AFTERNOON/EARLY EVENING...THEN TO EASTERN AREAS THROUGH LATE EVENING. SOME FOG WILL ALSO BE POSSIBLE...ESPECIALLY AROUND THE LAKE AND AS THE GRADIENT RELAXES. THERE WILL BE A CONTINUED CHANCE FOR SHOWERS ON SUNDAY...ALTHOUGH COVERAGE WILL BE LESS THAN WHAT HAS OCCURRED TODAY AND WHAT IS EXPECTED TONIGHT. THERE SHOULD STILL BE PLENTY OF CLOUDS AROUND THOUGH...AND THE MODELS CONTINUE TO SHOW PLENTY OF LOW LEVEL MOISTURE REMAINING. THE EXCEPTION WILL BE PORTIONS OF OUR SOUTHEAST ZONES EARLY...AND OUR FAR NORTHWEST ZONES LATE. HIGHS SUNDAY WILL RANGE FROM 55 TO 60 OVER OUR WESTERN/SOUTHEAST ZONES...WITH AREAS BETWEEN AROUND 50. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 319 PM CDT SAT OCT 5 2013 TAIL END OF A DEPARTING LOW PRESSURE SYSTEM OVER THE GREAT LAKES WILL ALLOW A FEW LIGHT RAIN SHOWERS TO LINGER ACROSS THE ERN HALF OF THE FORECAST AREA SUNDAY NIGHT INTO EARLY MONDAY MORNING. RAINFALL AMTS WILL BE LOW. HIGH PRESSURE WILL BUILD IN ACROSS THE UPPER MIDWEST MONDAY AND TUESDAY WITH QUIET WEATHER CONDITIONS AND WARMER TEMPERATURES. SKIES WILL REMAIN MOSTLY SUNNY EARLY IN THE WEEK BEFORE A WEAK SFC FRONT SLIDES ACROSS THE NRN PLAINS AND USHERS IN ADDITIONAL CLOUD COVER WED AND THURSDAY...MAINLY OVER THE NRN COUNTIES. THE UPPER RIDGE OVER THE ERN US WILL AMPLIFY LATE IN THE WEEK AS A TROUGH IN THE WEST DEEPENS THROUGH THE ROCKIES. THIS UPPER LOW WILL EVENTUALLY MOVE INTO THE MIDWEST BY THE WEEKEND AND BRING ADDITIONAL CHANCES FOR PRECIPITATION. TEMPERATURES WILL REMAIN ABOVE AVERAGE THIS WEEK WITH VERY MILD AFTERNOON HIGHS IN THE 60S AND LOWER 70S. OVERNIGHT LOWS EARLY IN THE WEEK WILL BE SLIGHTLY CHILLY INTO THE 30S AND LOWER 40S...BUT RISE INTO THE UPPER 40S AND LOWER 50S BY THE LATTER HALF OF THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1243 AM CDT SUN OCT 6 2013 BAND OF RAIN OVER THE TERMINALS AS OF MIDNIGHT WILL CONTINUE TO SHIFT NORTH AND NARROW OVER THE NEXT FEW HOURS. LIFR TO IFR CONDITIONS OVER TERMINALS SHOULD REMAIN STEADY OR SLOWLY IMPROVE TO IFR OVERNIGHT WITH -RA OR -DZ. SUNDAY MORNING CIGS SHOULD GRADUALLY IMPROVE TO MVFR...WITH GRADUAL CLEARING FROM WEST TO EAST EXPECTED AFTER 22Z. CLEAR AND COLD VFR CONDITIONS EXPECTED AFTER THAT. && .PRELIMINARY POINT TEMPS/POPS... DLH 40 62 41 64 / 20 10 0 0 INL 37 62 40 66 / 0 0 0 0 BRD 39 65 42 68 / 10 0 0 0 HYR 40 61 41 67 / 30 10 0 0 ASX 43 62 43 66 / 40 10 0 10 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 10 AM CDT THIS MORNING FOR LSZ121- 140>143-146>148. GALE WARNING UNTIL 4 AM CDT EARLY THIS MORNING FOR LSZ144-145. && $$ SHORT TERM...MELDE LONG TERM...BJT AVIATION...LE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
304 AM EDT SUN OCT 6 2013 .SYNOPSIS... A STATIONARY FRONT...CURRENTLY NEAR THE NEW YORK PENNSYLVANIA BORDER...WILL GRADUALLY LIFT NORTH AS A WARM FRONT TODAY. THIS WILL KEEP OUR WEATHER UNSETTLED WITH SCATTERED SHOWERS AND THUNDERSTORMS. A STRONG COLD FRONT WILL CROSS THE REGION ON MONDAY WITH MORE SHOWERS AND THUNDERSTORMS ALONG WITH THE POSSIBILITY OF HEAVY RAIN. HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY WITH FAIR WEATHER EXPECTED TO CONTINUE THROUGH THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... S/WV...MOST EVIDENT IN THE 700 MB WIND FIELD OVER WRN NY...AND NEARLY STNRY FNTL BNDRY ACRS THE TWIN TIERS...HELPING TO TRIGGER SCT SHRA/TSRA ACRS THE FCST AREA. RUC INDICATES THAT ANOTHER WEAK S/WV OVER SW PA WILL MAKE A RUN TWDS THE SRN TIER TWDS MRNG WHICH MAY TRIGGER MORE SCT ACTIVITY. 925-850 RH`S SUGGEST THE CNTRL SRN TIER AND FINGER LAKES BREAK OUT THIS AFTN (ALSO PORTIONS OF NE PA) LOW CLD AND COOLER TEMPS XPCTD ACRS ERN ZONES...PRIMARILY THE CATSKILLS...ERN SUSQ RGN AND WRN MOHAWK VLY WHERE MOIST LOW LVL SELY FLOW HELPS KEEP MSTR LOCKED IN. INTERESTINGLY..THE LCL WRF SUGGESTS THAT DIFF HEATING DUE TO THESE CLDS MAY HELP TO TRIGGER SCT TSRA OVER THE FINGER LAKES AND CNTRL SRN TIER THIS AFTN. WILL KEEP HIEST POPS ACRS NRN ZONES TDA...WITH MAXES FROM THE U70S WRN ZONES TO M/U60S ACRS PORTIONS OF THE CATSKILLS. A RELATIVE LACK OF PCPN IS XPCTD TNGT. PROFILES SUGGEST THAT SELY FLOW WILL ADVECT LOW CLDS/STRATUS BACK INTO THE FCST AREA OVRNGT. LOWS WILL BE VERY MILD...FROM THE MID AND PSBLY U60S ACRS THE FINGER LAKES...TO AROUND 60 IN FAR EAST. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... SIG CHGS MADE TO THE SHORT TERM GIVEN GOOD AGREEMENT BETWEEN THE 00Z GFS AND 12Z EURO...WHICH ADVERTISED A QUICKER PROGRESSION OF THE FNT/UPR TROF THRU THE FCST AREA. LOOKING AT WATER VAPOR IMAGERY THIS MRNG...IT APPEARS LIKELY THAT NRN STREAM S/WV WILL GIVE THIS SYSTEM A NUDGE AND KEEP IT PROGRESSIVE AS IT MOVS NEWD. THEREFORE WE SPED UP THE FNTL TIMING...XPCTNG IT TO PASS ON MONDAY. THIS WILL REDUCE THE POTNL FOR FLOODING PRBLMS...BUT WITH PW`S IN THE 1.5 TO 1.75 RNG...+RA WILL BE PSBL IN ADDITION TO EMBEDDED TSRA. TEMPS LIKELY TO BE FALLING SPCLY W OF I-81 DURING THE AFTN POST FROPA. POTNL FOR SOME -SHRA ACRS FAR NRN ZONES DUE TO LINGERING EFFECTS OF THE UPR TROF AND NW FLOW. HI PRES WILL BUILD INTO THE REGION FROM THE OH VLY/GTLAKES ON TUE...WITH MRNG CLDS GIVING WAY TO A MOSTLY SUNNY DAY AS RIDGING OCCURS. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... 3 AM UPDATE... HIPRES BOTH AT THE SFC AND ALOFT WL KEEP THE LONG TERM QUIET. HV GONE COMPLETELY DRY TO START OFF THE EXTNDD PD WITH BOTH GFS COMING INTO LINE WITH THE FASTER EURO IN BUILDING THE RIDGE IN BY TUE AND WELL-ESTABLISHED BY WED. STILL EXPECTING TEMPS TO START OFF SEASONAL AND THEN SLOWLY MODERATE THRU THE END OF THE WEEK. PREV DISCUSSION BLO... 240 PM EDT UPDATE... A MUCH DRIER WEATHER PATTERN IS EXPECTED IN THE EXTENDED THAN IN THE NEAR TERM. THE UPR LVL TROUGH THAT WILL BRING SHOWERS AND THUNDERSTORMS OVER THE NEXT COUPLE OF DAYS WILL PUSH OUT OF THE AREA TUESDAY/TUESDAY NIGHT. IN ITS WAKE AN UPPER AND LOWER LVL RIDGE WILL BUILD INTO THE REGION. THERE WILL STILL BE A SLIGHT CHANCE FOR SHOWERS ON TUESDAY/TUESDAY NIGHT FROM LINGERING MOISTURE OF KAREN BUT WILL DIMINISH QUICKLY THEREAFTER. WENT CLOSELY WITH WPC GUIDANCE AND KEPT THE FORECAST DRY AS CHANCES FOR RAIN ARE VERY MINIMAL THROUGH THE EXTENDED. HIGH TEMPS STARTING WED THROUGH SAT WILL BE MUCH COOLER AS WELL... WITH HIGHS REMAINING IN THE MID TO UPPER 60S EVEN THOUGH CLOUD COVERAGE WILL BE FOR THE MOST PART PARTLY CLOUDY. THESE TEMPS WILL BE CLOSER TO THE SEASONABLE NORM BUT ARE STILL ABOVE AVERAGE. COOLER TEMPS ARE AHEAD. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... 06Z UPDATE... LOW MVFR/IFR CONDITIONS EXPECTED THROUGH MORNING AS AREA REMAINS IN MOIST AIRMASS COURTESY OF STATIONARY FRONT. KITH AND KBGM WILL BE BELOW AIRFIELD MINIMUMS THROUGH AT LEAST 13Z THIS MORNING, BEFORE GRADUALLY COMING UP. ELSEWHERE MVFR AND POSSIBLY IFR WILL SET IN THROUGH 14Z. FRONTAL BOUNDARY WILL MOVE NORTH AS A WARM FRONT BUT CONDITIONS WILL BE SLOW TO IMPROVE AND MOST LOCATIONS WITH THE EXCEPTION OF KELM/KITH AND KAVP WILL REMAIN MVFR FOR THE NEXT 24 HOURS. CONDITIONS WILL DETERIORATE AFTER SUNSET THIS EVENING. HAVE TRIED TO INDICATE BEST CHANCE FOR SHOWERS WITH RME/SYR EXPERIENCING SHOWERS BETWEEN 18Z AND 23Z AND KELM/KITH AND KBGM BETWEEN 15Z AND 19Z. HOWEVER, SHOWERS MAY DEVELOP AT ANYTIME AND POSSIBLY THUNDER AS WELL. LGT/VRB SFC WINDS EARLY...WILL BECOME SRLY ON SUN...INCREASING TO 8-12 KT. OUTLOOK... MON THRU TUE...AN UNSETTLED PERIOD...WITH SCATTERED TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF RESTRICTIVE CONDS FROM TIME TO TIME. TUE NGT THRU THUR...MAINLY VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM...KAH/PVN AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
257 AM EDT SUN OCT 6 2013 .SYNOPSIS... A STATIONARY FRONT...CURRENTLY NEAR THE NEW YORK PENNSYLVANIA BORDER...WILL GRADUALLY LIFT NORTH AS A WARM FRONT TODAY. THIS WILL KEEP OUR WEATHER UNSETTLED WITH SCATTERED SHOWERS AND THUNDERSTORMS. A STRONG COLD FRONT WILL CROSS THE REGION ON MONDAY WITH MORE SHOWERS AND THUNDERSTORMS ALONG WITH THE POSSIBILITY OF HEAVY RAIN. HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY WITH FAIR WEATHER EXPECTED TO CONTINUE THROUGH THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... S/WV...MOST EVIDENT IN THE 700 MB WIND FIELD OVER WRN NY...AND NEARLY STNRY FNTL BNDRY ACRS THE TWIN TIERS...HELPING TO TRIGGER SCT SHRA/TSRA ACRS THE FCST AREA. RUC INDICATES THAT ANOTHER WEAK S/WV OVER SW PA WILL MAKE A RUN TWDS THE SRN TIER TWDS MRNG WHICH MAY TRIGGER MORE SCT ACTIVITY. 925-850 RH`S SUGGEST THE CNTRL SRN TIER AND FINGER LAKES BREAK OUT THIS AFTN (ALSO PORTIONS OF NE PA) LOW CLD AND COOLER TEMPS XPCTD ACRS ERN ZONES...PRIMARILY THE CATSKILLS...ERN SUSQ RGN AND WRN MOHAWK VLY WHERE MOIST LOW LVL SELY FLOW HELPS KEEP MSTR LOCKED IN. INTERESTINGLY..THE LCL WRF SUGGESTS THAT DIFF HEATING DUE TO THESE CLDS MAY HELP TO TRIGGER SCT TSRA OVER THE FINGER LAKES AND CNTRL SRN TIER THIS AFTN. WILL KEEP HIEST POPS ACRS NRN ZONES TDA...WITH MAXES FROM THE U70S WRN ZONES TO M/U60S ACRS PORTIONS OF THE CATSKILLS. A RELATIVE LACK OF PCPN IS XPCTD TNGT. PROFILES SUGGEST THAT SELY FLOW WILL ADVECT LOW CLDS/STRATUS BACK INTO THE FCST AREA OVRNGT. LOWS WILL BE VERY MILD...FROM THE MID AND PSBLY U60S ACRS THE FINGER LAKES...TO AROUND 60 IN FAR EAST. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... SIG CHGS MADE TO THE SHORT TERM GIVEN GOOD AGREEMENT BETWEEN THE 00Z GFS AND 12Z EURO...WHICH ADVERTISED A QUICKER PROGRESSION OF THE FNT/UPR TROF THRU THE FCST AREA. LOOKING AT WATER VAPOR IMAGERY THIS MRNG...IT APPEARS LIKELY THAT NRN STREAM S/WV WILL GIVE THIS SYSTEM A NUDGE AND KEEP IT PROGRESSIVE AS IT MOVS NEWD. THEREFORE WE SPED UP THE FNTL TIMING...XPCTNG IT TO PASS ON MONDAY. THIS WILL REDUCE THE POTNL FOR FLOODING PRBLMS...BUT WITH PW`S IN THE 1.5 TO 1.75 RNG...+RA WILL BE PSBL IN ADDITION TO EMBEDDED TSRA. TEMPS LIKELY TO BE FALLING SPCLY W OF I-81 DURING THE AFTN POST FROPA. POTNL FOR SOME -SHRA ACRS FAR NRN ZONES DUE TO LINGERING EFFECTS OF THE UPR TROF AND NW FLOW. HI PRES WILL BUILD INTO THE REGION FROM THE OH VLY/GTLAKES ON TUE...WITH MRNG CLDS GIVING WAY TO A MOSTLY SUNNY DAY AS RIDGING OCCURS. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... 240 PM EDT UPDATE... A MUCH DRIER WEATHER PATTERN IS EXPECTED IN THE EXTENDED THAN IN THE NEAR TERM. THE UPR LVL TROUGH THAT WILL BRING SHOWERS AND THUNDERSTORMS OVER THE NEXT COUPLE OF DAYS WILL PUSH OUT OF THE AREA TUESDAY/TUESDAY NIGHT. IN ITS WAKE AN UPPER AND LOWER LVL RIDGE WILL BUILD INTO THE REGION. THERE WILL STILL BE A SLIGHT CHANCE FOR SHOWERS ON TUESDAY/TUESDAY NIGHT FROM LINGERING MOISTURE OF KAREN BUT WILL DIMINISH QUICKLY THEREAFTER. WENT CLOSELY WITH WPC GUIDANCE AND KEPT THE FORECAST DRY AS CHANCES FOR RAIN ARE VERY MINIMAL THROUGH THE EXTENDED. HIGH TEMPS STARTING WED THROUGH SAT WILL BE MUCH COOLER AS WELL... WITH HIGHS REMAINING IN THE MID TO UPPER 60S EVEN THOUGH CLOUD COVERAGE WILL BE FOR THE MOST PART PARTLY CLOUDY. THESE TEMPS WILL BE CLOSER TO THE SEASONABLE NORM BUT ARE STILL ABOVE AVERAGE. COOLER TEMPS ARE AHEAD. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... 06Z UPDATE... LOW MVFR/IFR CONDITIONS EXPECTED THROUGH MORNING AS AREA REMAINS IN MOIST AIRMASS COURTESY OF STATIONARY FRONT. KITH AND KBGM WILL BE BELOW AIRFIELD MINIMUMS THROUGH AT LEAST 13Z THIS MORNING, BEFORE GRADUALLY COMING UP. ELSEWHERE MVFR AND POSSIBLY IFR WILL SET IN THROUGH 14Z. FRONTAL BOUNDARY WILL MOVE NORTH AS A WARM FRONT BUT CONDITIONS WILL BE SLOW TO IMPROVE AND MOST LOCATIONS WITH THE EXCEPTION OF KELM/KITH AND KAVP WILL REMAIN MVFR FOR THE NEXT 24 HOURS. CONDITIONS WILL DETERIORATE AFTER SUNSET THIS EVENING. HAVE TRIED TO INDICATE BEST CHANCE FOR SHOWERS WITH RME/SYR EXPERIENCING SHOWERS BETWEEN 18Z AND 23Z AND KELM/KITH AND KBGM BETWEEN 15Z AND 19Z. HOWEVER, SHOWERS MAY DEVELOP AT ANYTIME AND POSSIBLY THUNDER AS WELL. LGT/VRB SFC WINDS EARLY...WILL BECOME SRLY ON SUN...INCREASING TO 8-12 KT. OUTLOOK... MON THRU TUE...AN UNSETTLED PERIOD...WITH SCATTERED TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF RESTRICTIVE CONDS FROM TIME TO TIME. TUE NGT THRU THUR...MAINLY VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM...KAH AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
256 AM EDT SUN OCT 6 2013 .SYNOPSIS... A STATIONARY FRONT. CURRENTLY NEAR THE NEW YORK PENNSYLVANIA BORDER, WILL GRADUALLY LIFT NORTH AS A WARM FRONT TODAY. THIS WILL KEEP OUR WEATHER UNSETTLED WITH SCATTERED SHOWERS AND THUNDERSTORMS. A STRONG COLD FRONT WILL CROSS THE REGION ON MONDAY WITH MORE SHOWERS AND THUNDERSTORMS ALONG WITH THE POSSIBILITY OF HEAVY RAIN. HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY WITH FAIR WEATHER EXPECTED TO CONTINUE THROUGH THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... S/WV...MOST EVIDENT IN THE 700 MB WIND FIELD OVER WRN NY...AND NEARLY STNRY FNTL BNDRY ACRS THE TWIN TIERS...HELPING TO TRIGGER SCT SHRA/TSRA ACRS THE FCST AREA. RUC INDICATES THAT ANOTHER WEAK S/WV OVER SW PA WILL MAKE A RUN TWDS THE SRN TIER TWDS MRNG WHICH MAY TRIGGER MORE SCT ACTIVITY. 925-850 RH`S SUGGEST THE CNTRL SRN TIER AND FINGER LAKES BREAK OUT THIS AFTN (ALSO PORTIONS OF NE PA) LOW CLD AND COOLER TEMPS XPCTD ACRS ERN ZONES...PRIMARILY THE CATSKILLS...ERN SUSQ RGN AND WRN MOHAWK VLY WHERE MOIST LOW LVL SELY FLOW HELPS KEEP MSTR LOCKED IN. INTERESTINGLY..THE LCL WRF SUGGESTS THAT DIFF HEATING DUE TO THESE CLDS MAY HELP TO TRIGGER SCT TSRA OVER THE FINGER LAKES AND CNTRL SRN TIER THIS AFTN. WILL KEEP HIEST POPS ACRS NRN ZONES TDA...WITH MAXES FROM THE U70S WRN ZONES TO M/U60S ACRS PORTIONS OF THE CATSKILLS. A RELATIVE LACK OF PCPN IS XPCTD TNGT. PROFILES SUGGEST THAT SELY FLOW WILL ADVECT LOW CLDS/STRATUS BACK INTO THE FCST AREA OVRNGT. LOWS WILL BE VERY MILD...FROM THE MID AND PSBLY U60S ACRS THE FINGER LAKES...TO AROUND 60 IN FAR EAST. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... SIG CHGS MADE TO THE SHORT TERM GIVEN GOOD AGREEMENT BETWEEN THE 00Z GFS AND 12Z EURO...WHICH ADVERTISED A QUICKER PROGRESSION OF THE FNT/UPR TROF THRU THE FCST AREA. LOOKING AT WATER VAPOR IMAGERY THIS MRNG...IT APPEARS LIKELY THAT NRN STREAM S/WV WILL GIVE THIS SYSTEM A NUDGE AND KEEP IT PROGRESSIVE AS IT MOVS NEWD. THEREFORE WE SPED UP THE FNTL TIMING...XPCTNG IT TO PASS ON MONDAY. THIS WILL REDUCE THE POTNL FOR FLOODING PRBLMS...BUT WITH PW`S IN THE 1.5 TO 1.75 RNG...+RA WILL BE PSBL IN ADDITION TO EMBEDDED TSRA. TEMPS LIKELY TO BE FALLING SPCLY W OF I-81 DURING THE AFTN POST FROPA. POTNL FOR SOME -SHRA ACRS FAR NRN ZONES DUE TO LINGERING EFFECTS OF THE UPR TROF AND NW FLOW. HI PRES WILL BUILD INTO THE REGION FROM THE OH VLY/GTLAKES ON TUE...WITH MRNG CLDS GIVING WAY TO A MOSTLY SUNNY DAY AS RIDGING OCCURS. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... 240 PM EDT UPDATE... A MUCH DRIER WEATHER PATTERN IS EXPECTED IN THE EXTENDED THAN IN THE NEAR TERM. THE UPR LVL TROUGH THAT WILL BRING SHOWERS AND THUNDERSTORMS OVER THE NEXT COUPLE OF DAYS WILL PUSH OUT OF THE AREA TUESDAY/TUESDAY NIGHT. IN ITS WAKE AN UPPER AND LOWER LVL RIDGE WILL BUILD INTO THE REGION. THERE WILL STILL BE A SLIGHT CHANCE FOR SHOWERS ON TUESDAY/TUESDAY NIGHT FROM LINGERING MOISTURE OF KAREN BUT WILL DIMINISH QUICKLY THEREAFTER. WENT CLOSELY WITH WPC GUIDANCE AND KEPT THE FORECAST DRY AS CHANCES FOR RAIN ARE VERY MINIMAL THROUGH THE EXTENDED. HIGH TEMPS STARTING WED THROUGH SAT WILL BE MUCH COOLER AS WELL... WITH HIGHS REMAINING IN THE MID TO UPPER 60S EVEN THOUGH CLOUD COVERAGE WILL BE FOR THE MOST PART PARTLY CLOUDY. THESE TEMPS WILL BE CLOSER TO THE SEASONABLE NORM BUT ARE STILL ABOVE AVERAGE. COOLER TEMPS ARE AHEAD. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... 06Z UPDATE... LOW MVFR/IFR CONDITIONS EXPECTED THROUGH MORNING AS AREA REMAINS IN MOIST AIRMASS COURTESY OF STATIONARY FRONT. KITH AND KBGM WILL BE BELOW AIRFIELD MINIMUMS THROUGH AT LEAST 13Z THIS MORNING, BEFORE GRADUALLY COMING UP. ELSEWHERE MVFR AND POSSIBLY IFR WILL SET IN THROUGH 14Z. FRONTAL BOUNDARY WILL MOVE NORTH AS A WARM FRONT BUT CONDITIONS WILL BE SLOW TO IMPROVE AND MOST LOCATIONS WITH THE EXCEPTION OF KELM/KITH AND KAVP WILL REMAIN MVFR FOR THE NEXT 24 HOURS. CONDITIONS WILL DETERIORATE AFTER SUNSET THIS EVENING. HAVE TRIED TO INDICATE BEST CHANCE FOR SHOWERS WITH RME/SYR EXPERIENCING SHOWERS BETWEEN 18Z AND 23Z AND KELM/KITH AND KBGM BETWEEN 15Z AND 19Z. HOWEVER, SHOWERS MAY DEVELOP AT ANYTIME AND POSSIBLY THUNDER AS WELL. LGT/VRB SFC WINDS EARLY...WILL BECOME SRLY ON SUN...INCREASING TO 8-12 KT. OUTLOOK... MON THRU TUE...AN UNSETTLED PERIOD...WITH SCATTERED TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF RESTRICTIVE CONDS FROM TIME TO TIME. TUE NGT THRU THUR...MAINLY VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ LONG TERM...KAH AVIATION...PVN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
229 AM EDT SUN OCT 6 2013 .SYNOPSIS... HIGH PRESSURE OVER THE REGION WILL MOVE SLOWLY EAST AND OFFSHORE THIS AFTERNOON AND TONIGHT. A COLD FRONT WILL MOVE INTO THE PIEDMONT MONDAY AFTERNOON... THEN PUSH EAST ACROSS THE AREA MONDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTH TUESDAY THROUGH MID-WEEK. && .NEAR TERM /TONIGHT/... AS OF 850 PM SATURDAY... OBSERVATIONAL DATA TRENDS PROVIDE LITTLE REASON TO STRAY FROM PERSISTENCE...FROM BOTH THE PREVIOUS FORECAST AND PREVIOUS NIGHT. 00Z/6TH UPPER AIR DATA REVEALS A DEEP LAYER ANTICYCLONE SITUATED DIRECTLY OVER THE CAROLINAS THIS EVENING...WITH AN ACCOMPANYING BERMUDA RIDGE AXIS AND FLAT PRESSURE GRADIENT AT THE SURFACE. THE VISIBILITY FORECAST FROM THE PAST SEVERAL RUNS OF THE HRRR ALL STRONGLY SUPPORT THE IDEA OF AREAS OF FOG BECOMING LOCALLY DENSE...MAINLY INVOF AND EAST OF US HWY 1. LOWS AGAIN MOSTLY IN THE LOWER 60S. && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... AS OF 255 PM SATURDAY... PRECIPITABLE WATER VALUES HOLD IN THE NORMAL RANGE...AROUND AN INCH TO 1.25 INCHES...THROUGH THE DAY SUNDAY. 850MB THETA-E STARTS TO INCREASE LATE IN THE DAY ESPECIALLY OVER THE FAR WESTERN PIEDMONT...BUT K INDICES REMAIN RELATIVELY LOW IN THE TEENS... INDICATIVE OF DRY MID-LEVEL AIR. BUFR SOUNDINGS SHOW A GOOD CAP PERSISTS AROUND 600MB THROUGH THE DAY SUNDAY...AND ALTHOUGH THE GFS QPF HAS MARGINAL VALUES TOWARD KFAY AND KCTZ LATE SUNDAY AFTERNOON...LIKELY ALONG THE SEA BREEZE...THE SREF AND NAM ARE DRY...THE GFS BUFR SOUNDINGS REMAIN CAPPED...AND MAV MOS GUIDANCE POPS ARE IN SINGLE FIGURES. WILL CONTINUE A DRY FORECAST FOR THE DAY SUNDAY. 850MB MOISTURE OVERALL IS GREATER ON BOTH THE NAM AND GFS BUFR SOUNDINGS SUNDAY COMPARED TO TODAY...WHICH SHOULD RESULT IN AT LEAST GREATER COVERAGE OF CU...HOLDING TEMPERATURES A LITTLE LOWER DESPITE A MORE NOTICEABLE SOUTHERLY BREEZE...AVERAGING AT OR JUST UNDER 10MPH AFTER MIXING. 1000-850MB THICKNESSES SUPPORT TEMPERATURES NEAR THE MOS GUIDANCE...CONSISTENT AMONG THE MAV AND MET IN THE MID TO UPPER 80S. SUNDAY NIGHT...FAIRLY RAPID MOISTENING TAKES PLACE MAINLY AFTER MIDNIGHT AS A 50KT 500MB JET APPROACHES TO OUR NORTHWEST LATE SUNDAY NIGHT...AND A LOW-LEVEL JET WITH WINDS AROUND 35KT AT 850MB AND 30KT AT 925MB MOVES EAST TOWARD...OR INTO...THE WESTERN PIEDMONT BY SUNRISE MONDAY. THE GFS IS FASTER THAN THE NAM...WITH THE FORMER CERTAINLY FARTHER EAST WITH THE LOW-LEVEL JET AND INCREASE IN 850MB THETA-E BY 12Z MONDAY. BOTH THE NAM AND THE GFS SUPPORT AT LEAST A MODEST MID-LEVEL SHORTWAVE MOVING ACROSS THE WESTERN PIEDMONT LATE AT NIGHT...WITH INCREASING LIFT ALONG AND AHEAD OF THE WAVE AND THE INCREASING WINDS ALOFT. IN DEFERENCE TO THE NAM...WILL REFRAIN FROM CATEGORICAL CHANCES OF PRECIPITATION FOR NOW...WHILE FORECASTING HIGH LIKELY POPS TOWARD THE TRIAD AND THE YADKIN RIVER LATE SUNDAY NIGHT...AND INCREASING SIMPLE CHANCE FARTHER EAST PARTICULARLY TOWARD U.S. 1. BUFR SOUNDINGS SHOW CHANCES FOR THUNDER SHOULD BE SOMEWHAT REMOTE UNTIL POSSIBLY VERY LATE SUNDAY NIGHT...AS 0-3KM SHEAR INCREASES TO 25 TO 30KT. 0-3KM HELICITY REMAINS JUST UNDER 100M2/S2 LATE ESPECIALLY ON THE GFS...THOUGH THERE IS SOME CONCERN CURRENTLY FOR LATE NIGHT ROTATING SHOWERS AS THE SHEAR AND MOISTURE INCREASE...AND AS THERE DEVELOPS BETTER LOW-LEVEL TURNING OF THE WINDS LATE. WILL CONTINUE TO MONITOR LATER GUIDANCE RUNS REGARDING THIS. CLOUDS INCREASE OVERNIGHT...AND WINDS MAINTAIN THEMSELVES... LEADING TO MUCH WARMER OVERNIGHT LOWS MAINLY IN THE MID TO UPPER 60S. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 229 AM SUNDAY... A MUCH COOLER AIR MASS WILL FILTER INTO OUR REGION COURTESY OF THE STRONG (1030 MB) SURFACE HIGH PRESSURE PRESSURE THAT IS FORECAST TO BE CENTERED OVER NEW ENGLAND TUESDAY INTO WEDNESDAY. THE MAIN FORECAST QUESTION WILL BE THE EXTENT OF THE POST-FRONTAL CLOUDINESS AND POSSIBLY SOME LIGHT RAIN IN THE EAST AND SOUTH TUESDAY. THE POTENTIAL FOR LINGERING CLOUDINESS/LIGHT RAIN MAY ALSO BE ENHANCED BY THE POTENTIAL FOR SOME UPPER SUPPORT TO LINGER ALONG THE SE US COAST INTO TUESDAY AS WELL. NOT ALL MODEL SOLUTIONS ARE ON BOARD WITH THE LINGERING UPPER SUPPORT. HOWEVER... THERE APPEARS TO BE GOOD OVERALL AGREEMENT IN AT LEAST LOW LEVEL MOISTURE LINGERING INTO TUESDAY DUE TO THE MOIST ONSHORE NE FLOW ALONG THE COAST EXTENDING INLAND INTO THE FAR EASTERN COASTAL PLAIN. MODELS SUGGEST MUCH DRIER AIR INLAND WHERE THE PIEDMONT SHOULD SEE AMPLE CLEARING TUESDAY AS THE DRIER MID LEVEL AIR DIVES INTO THE PIEDMONT. FOR TUESDAY THROUGH WEDNESDAY... A CHANCE OF LINGERING LIGHT SHOWERS IN THE SE ZONES EARLY TUESDAY... THEN VARIABLY CLOUDY BREEZY AND COOLER. PARTLY SUNNY ELSEWHERE... BREEZY AND COOLER TUESDAY. THEN MOSTLY CLEAR TO PARTLY CLOUDY TUESDAY NIGHT AND WEDNESDAY NIGHT. TEMPS SHOULD BE NEAR NORMAL (HIGHS 70-75)... LOWS 50-55. THE FORECAST FOR THURSDAY THROUGH SATURDAY HAS BECOME MUDDLED IN THE PAST FEW DAYS. THERE ARE A WIDE RANGE OF POSSIBILITIES WITHIN THE MODELS RANGING FROM THE POTENTIAL FOR SIGNIFICANT WAVE DEVELOPMENT ALONG THE OLD SURFACE BOUNDARY ALONG THE SE COAST... TO EVEN THE POTENTIAL FOR A RETROGRADING MID/UPPER LOW FROM THE WESTERN ATLANTIC BACK TOWARD... OR EVEN INLAND... ALONG THE EASTERN SEABOARD LATE IN THE WEEK INTO THE WEEKEND. THE TRENDS ARE FOR THE VERY LEAST A MORE UNSETTLED PATTERN... WITH INCREASING POTENTIAL FOR WETNESS LATE IN THE WEEK. FOR NOW... WE WILL SHOW A GRADUAL INCREASE IN CLOUDS WED-THU... WITH A CHANCE OF RAIN BY FRI-SAT. THE HIGH PRESSURE TO THE NORTH WILL CONTINUE THE COOL TEMPERATURE RESUME THROUGH THE WEEK AS THE FLOW CONTINUES FROM THE NE. LOWS UPPER 40S TO MID 50S INCREASING TO MID TO UPPER 50S BY SAT. HIGHS IN THE LOWER TO MID 70S. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 657 PM SATURDAY... PERSISTENCE FORECAST WITH VFR CONDITIONS GIVING WAY TO AREAS OF FOG LATE TONIGHT BETWEEN 06 TO 12Z....WITH HIGHEST PROBABILITIES AND CORRESPONDINGLY LOWER VISIBILITIES EXPECTED IN THE EAST AT KRWI AND KFAY. VFR CONDITIONS SHOULD RETURN BY 14 TO 15Z WITH TIGHTENING PRESSURE GRADIENT IN RESPONSE TO THE APPROACHING COLD FRONT FROM THE WEST PROVIDING A GOOD 7 TO 10KT SOUTHERLY BREEZY SUNDAY AFTERNOON. BEYOND THE 24 HOUR TAF PERIOD...STRENGTHENING SOUTHERLY MOISTURE TRANSPORT IN ADVANCE OF A COLD FRONT APPROACHING FROM THE WEST WILL RESULTING IN DETERIORATING AVIATION CONDITIONS LATE SUNDAY NIGHT/MONDAY MORNING WITH LOW CLOUDS AND SHOWERS DEVELOPING OVER THE THE AREA...WITH BEST COVERAGE AND CORRESPONDING LOWER RESTRICTIONS IN THE WEST. A BAND OF SHOWERS AND POSSIBLY STORMS ARE THEN EXPECTED TO CROSS THE AREA MONDAY AFTERNOON/EVENING. VFR CONDITIONS ARE LIKELY TO RETURN BY TUESDAY AND SHOULD CONTINUE THROUGH THURSDAY...WITH ONLY A SMALL PROBABILITY OF LOW CLOUDS IN A LOW-LEVEL NORTHEAST FLOW LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...BADGETT NEAR TERM...MWS SHORT TERM...DJF LONG TERM...BADGETT AVIATION...CBL/DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
132 AM EDT SUN OCT 6 2013 .SYNOPSIS... WARM CONDITIONS WILL CONTINUE THROUGH THE WEEKEND WITH SHOWERS POSSIBLE SUNDAY AS ATLANTIC MOISTURE INCREASES. A STRONG COLD FRONT WILL MERGE WITH THE REMNANTS OF TROPICAL DEPRESSION KAREN...BRINGING UNSETTLED WEATHER TO THE AREA LATE MONDAY INTO EARLY TUESDAY. DRY AND COOLER HIGH PRESSURE WILL BUILD FROM THE NORTH MID WEEK. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... AS OF 130 AM SUNDAY...THE ONLY SIGNIFICANT CHANGE TO THE FORECAST EARLY THIS MORNING WAS TO ADD CONSIDERABLY LOW CLOUDINESS THROUGH DAYBREAK. SPECIAL 11-3.9 MICRON SATELLITE IMAGERY CONFIRMS SURFACE OBSERVATIONS OF STRATUS DEVELOPING WITH BASES 200-300 FT AGL ACROSS MOST OF THE COASTAL CAROLINAS. PATCHY/AREAS OF FOG WILL DEVELOP AS WELL. NO SIGNIFICANT CHANGES TO OTHER FORECAST ELEMENTS. PREVIOUS DISCUSSION FROM 1100 PM SATURDAY FOLLOWS... DECENT RAD COOLING CONDITIONS TONIGHT WILL AGAIN PROMOTE FOG DEVELOPMENT ACROSS THE FA...WITH DENSE YET AGAIN A POSSIBILITY. SLIGHTLY STRONGER...RELATIVELY SPEAKING...SE FLOW PROGGED AT THE LOWER LEVELS VIA MODEL TIME HEIGHT CHARTS AND MODEL SOUNDINGS BY SUNDAY DAYBREAK. THIS CONTINUES TO WARRANT AREAS OF FOG DEVELOPMENT AS RAD COOLING CONDITIONS WILL BE ADVANTAGEOUS ALTHOUGH NOT AS PRONOUNCED LIKE PREVIOUS NIGHTS/EARLY MORNINGS. ONSHORE MOVEMENT OF SC/CU BY DAYBREAK FROM A DEEPER LOW LEVEL SE FLOW...WILL KEEP THE FOG DEVELOPMENT...COVERAGE AND INTENSITY LOWER ALONG THE IMMEDIATE COAST COMPARED TO THE PAST FEW NIGHTS. HOWEVER...FARTHER INLAND BASICALLY INCLUDING THE BULK OF THE ILM CWA...FOG WILL AGAIN BE THE PROBLEM OF THE NIGHT AND WILL IDENTIFY ITS OCCURRENCE IN THE FORECAST AND THE HWO. TONIGHTS LOWS WILL BE 1 TO 3 DEGREES HIGHER THAN THE PREVIOUS NIGHTS MINS...AND POSSIBLY EVEN HIGHER ALONG THE IMMEDIATE COAST WHERE THE PRONOUNCED ONSHORE MOVING AIRMASS WILL HAVE BEEN MODIFIED BY SSTS THAT ARE WELL INTO THE 70S. OVERALL...WILL BE LOOKING AT TONIGHTS MINS AT 5 TO 10 DEGREES ABOVE CLIMO NORMS. MODELS IN GENERAL OF LATE...ARE HAVING A SOMEWHAT DIFFICULT TIME FORECASTING SFC DEWPOINTS WITHIN THE NEAR TERM PERIOD. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/... AS OF 3 PM SATURDAY...A MILD TO WARM DAY ANTICIPATED SUNDAY AS AN UPPER RIDGE HOLDS ALONG THE SE US COAST WHILE SOUTHERLY WINDS CIRCULATE AROUND SURFACE HIGH PRESSURE POSITIONED OFFSHORE. DEEP ONSHORE WIND FLOW WILL BRING INCREASING COLUMN MOISTURE OVER THE FORECAST AREA BY SUNDAY AFTERNOON. THIS COMBINED WITH A COINCIDENT UPTICK IN LOW-LEVEL WIND CONVERGENCE COULD TRIP OFF A FEW SHOWERS SUNDAY AFTERNOON AND EVENING. DESPITE AN INCREASING TREND IN SOUTHERLY WINDS ON MONDAY...A DRY MID-LEVEL LAYER WILL SERVE TO HINDER PRECIPITATION COVERAGE. IT IS NOT UNTIL MONDAY NIGHT THAT POP VALUES ARE RAMPED UP INTO THE LIKELY CATEGORY...AS A PLUME OF MOISTURE RICH AND TROPICALLY ENHANCED AIR MOVES EAST ACROSS THE AREA. INCREASING ONSHORE LOW- LEVEL WINDS WILL MAINTAIN A TREND OF WARMING MINIMUM TEMPS THE NEXT FEW DAYS. BY DAYBREAK TUESDAY NORTH WINDS MAY BE GREETING THE DAY AS A SURFACE LOW PULLS OFFSHORE AND HIGH PRESSURE STRENGTHENS OVER THE GREAT LAKES REGION. WITH TROPICAL MOISTURE STILL DEEPLY ENTRENCHED OVER THE REGION AT THIS TIME...STRONG COOLING IS NOT EXPECTED UNTIL LATER IN THE FORECAST PERIOD. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 3 PM SATURDAY...A MUCH WEAKENED KAREN WILL NOW TRAVEL FURTHER SOUTH AND EAST THAN PREVIOUSLY FORECAST...IN FACT REMAINING SOUTHEAST OF THE AREA ALTOGETHER. WHATEVER IS LEFT FROM THE SYSTEM MOVES UP THE FRONTAL BOUNDARY WELL OFFSHORE ON TUESDAY. IT MAY HAVE ENOUGH A PRESENCE TO FLING A LITTLE RAIN-PRODUCING MOISTURE MAINLY EARLY IN THE DAY AND ALONG THE COAST. THE BALANCE OF TUESDAY SHOULD BRING A DRYING TREND AS SURFACE HIGH BUILDS IN FROM THE NORTH AND MID LEVEL TROUGH AXIS EXITS TO OUR EAST. MODELS NOW HINTING THAT THIS HIGH WILL KEEP A WIND OUT OF THE NORTH FOR THE REMAINDER OF THE PERIOD KEEPING DEWPOINTS FAIRLY LOW WHILE TEMPERATURES HANG CLOSE TO CLIMO. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 06Z...PLENTY OF LOW LEVEL MOISTURE IS BEING BROUGHT ONSHORE IN THE WEAK SOUTHEAST SYNOPTIC FLOW. WIDESPREAD LOW STRATUS WITH BASES 200-300 FT AGL IS ALREADY DEVELOPING JUST INLAND FROM THE COAST...AND LOCALIZED 1-3 SM VSBY IN FOG/MIST IS DEVELOPING WHERE CLOUDS HAVE NOT. VERY BAD AVIATION CONDITIONS HAVE A HIGH LIKELIHOOD OF PERSISTING AT FLO/LBT THROUGH 12Z...AND A MODERATE TO HIGH LIKELIHOOD OF DEVELOPING AT ILM ALTHOUGH THERE IS POTENTIAL FOR OCCASIONAL BREAKS TO MVFR/VFR CONDITIONS HERE. AT CRE/MYR ONSHORE WINDS HAVE KEPT CONDITIONS VFR SO FAR...ALTHOUGH AS THE NOCTURNAL BOUNDARY LAYER CONTINUES TO COOL AND WINDS BECOME CALM THERE IS THE POSSIBILITY FOR LOW CEILINGS AND FOG TO DEVELOP HERE TOO...WITH CONFIDENCE IN THE MODERATE CATEGORY AT CRE AND LOW TO MODERATE AT MYR. LATEST MODELS SHOW ISOLATED SHOWERS DEVELOPING OFF THE CAPE FEAR COAST MAY SURGE INLAND A COUPLE HOURS AFTER SUNRISE...WITH THE 13-16Z WINDOW HIGHLIGHTED FOR SCATTERED SHOWERS. VFR CONDITIONS SHOULD DEVELOP REGARDLESS. EXTENDED OUTLOOK...INCREASING CHANCES FOR SHOWERS AND MVFR CIGS MONDAY AND TUESDAY AS TROPICAL MOISTURE STREAMS AHEAD OF AN APPROACHING COLD FRONT. EXPECT MAINLY VFR WEDNESDAY AND THURSDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 130 AM SUNDAY...NO SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST. I DID EXPAND THE AREA OF ISOLATED SHOWERS GIVEN LATEST OBSERVED TRENDS FROM THE LTX RADAR AND THE LATEST HRRR RUN. PREVIOUS DISCUSSION FROM 1100 PM FOLLOWS... E-W SFC RIDGE AXIS EXTENDING FROM THE HIGHS CENTER WELL OFFSHORE FROM NC...WILL LIE ACROSS THE AREA WATERS AND EXTEND INLAND IN THE VICINITY OF CAPE FEAR. ENOUGH OF A SFC PRESSURE PATTERN TO IDENTIFY AND FORECAST A PREDOMINATE WIND DIRECTION WITH MORE AUTHORITY...COMPARED TO THE PREVIOUS SEVERAL NIGHTS. THE SFC PG WILL BE SLIGHTLY TIGHTER...AGAIN...COMPARED TO THE PAST FEW NIGHTS/MORNINGS...WITH SPEEDS AROUND 10 KT. SIGNIFICANT SEAS WILL BE AROUND 2 FT THRUOUT. MAJORITY OF THE SIGNIFICANT SEAS WILL BE COMPRISED OF THE 1.0 TO 1.5 FOOT EASTERLY GROUND SWELL EXHIBITING 9-11 SECOND PERIODS. THE FOG ALONG THE IMMEDIATE COAST WILL NOT BE AS INTENSE COMPARED TO THE PREVIOUS 2 NIGHTS/MORNINGS BUT WILL STILL POSE MARINERS PROBLEMS ACROSS THE FURTHER INLAND WATERWAYS IE. WINYAH BAY...LAKE WACCAMAW...AND POSSIBLY THE INTRACOASTAL WATERWAY. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3 PM SATURDAY...MARINE CONDITIONS WILL DETERIORATE SUNDAY INTO MONDAY AS A COLD FRONT APPROACHES FROM THE WEST. AN UPWARD TREND IN SSE WINDS IS EXPECTED SUNDAY AFTERNOON THROUGH MUCH OF MONDAY. THIS SHOULD BRING SEAS TO 4-5 FEET DURING THE DAY MONDAY AND S WIND GUSTS TO 20 KT...BRINGING A GOOD DOSE FOR AT LEAST "EXERCISE CAUTION" CONDITIONS MONDAY. SEAS WILL BE COMPRISED OF BUILDING SE WAVES IN INTERVALS RANGING BETWEEN MAINLY 6-9 SEC. A FEW THUNDERSTORMS WILL BE POSSIBLE ON THE WATERS MONDAY NIGHT. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 3 PM SATURDAY...ALTHOUGH THERE ARE STILL CONSIDERABLE UNCERTAINTIES IT SEEMS MUCH OF THE LONG TERM WILL BE QUITE UNSETTLED. THE UNCERTAINTY MAINLY RELATED TO THE REMNANTS OF TS KAREN AS IT MOVES UP THE FRONT OFF THE SOUTHEAST COAST. HOW MUCH THIS SYSTEM DROPS IN PRESSURE WILL AFFECT HOW TIGHT THE LOCAL GRADIENT BECOMES...AND OUR RESULTING WINDS/SEAS. GFS GUIDANCE IS TRENDING STRONGER WHILE OTHER MODELS SUCH AS ECMWF MUCH MORE TAME. NUDGED THE FORECAST IN A MORE PESSIMISTIC DIRECTION BUT NOT QUITE AS STRONG AS GFS SINCE NOT MANY OF THE ENSEMBLE PERTURBATIONS HAVE AS STRONG A SYSTEM AS THE OPERATIONAL RUN. NORTH TO NORTHEAST WINDS FOR MOST OF THE PERIOD WITH HIGH PRESSURE COVERING COPIOUS REAL ESTATE ACROSS THE EASTERN U.S. INCREASED DURATION OF THIS FETCH TO YIELD AN UPTICK IN SWELL ENERGY AS THE PERIOD PROGRESSES. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...DCH/TRA SHORT TERM...MJC LONG TERM...MBB AVIATION...TRA
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1147 PM CDT SAT OCT 5 2013 .UPDATE... ISSUED AT 1147 PM CDT SAT OCT 5 2013 THE BAND OF RAIN IS SHRINKING IN COVERAGE AND STARTING TO SHOW SIGNS OF WEAKENING. THE 02Z HRRR INDICATES THAT THIS TREND WILL CONTINUE WITH ONLY SCATTERED PRECIP REMAINING BY 09Z. TRENDED THE POPS TOWARD THIS THINKING. THE FREEZE/FROST HEADLINES IN GOOD SHAPE AS CLEARING ALONG WITH LIGHTER WINDS AND UPPER 20F DEWPOINTS WILL BE OVER THE HEADLINED AREA EARLY THIS MORNING. DO NOT THINK THAT THE HEADLINES WILL NEED TO BE EXPANDED AS LATEST RAP/HRRR SHOW THE CLEARING LINE GENERALLY WHERE THE HEADLINES ARE LOCATED (AND CLEAR SKY/NARROW RIDGE OF HIGH PRESSURE WILL BE THE KEY FOR LOWER MIN TEMPS). && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 325 PM CDT SAT OCT 5 2013 FORECAST CHALLENGE CONCERNS CONTINUED RAIN POTENTIAL/COVERAGE AND AMOUNTS. MODELS OVERALL IN PRETTY GOOD AGREEMENT WITH MAIN FEATURES. CONCERNING QPF WILL FOLLOW GEM/ECMWF/NAM BLEND AS GFS LOOKS A LITTLE OVERDONE FIRST 12 HOURS. STACKED LOW TO FINALLY START PROPAGATING EAST OVERNIGHT. PRIOR TO MORE PROGRESSIVE MOVEMENT RAIN TO BECOME MORE WIDESPREAD ACROSS MINNESOTA ARCING WEST AND SOUTHWEST ACROSS FA TONIGHT. THIS STARTING TO OCCUR WITH RAIN EXPANDING ACROSS EAST HALF OF MN IN ZONE OF UPPER LEVEL DIVERGENCE WITH EXIT REGION OF UPPER JET. MOST SIGNIFICANT BAND CURRENTLY DEVELOPING ACROSS NORTHERN FA IN MOIST AXIS WITH EVEN A FEW LTG STRIKES ACROSS NW MN. THIS BAND THEN TO PIVOT SE WITH TIME AS UPPER SYSTEM SHIFTS EAST. MADE BEST ATTEMPT WITH POPS HOWEVER EVENING SHIFT WILL LIKELY NEED TO ADJUST AS MAIN BAND DEVELOPS. AS LOW EXITS LATER THIS EVENING CLEARING SHOULD START WORKING INTO NW FA. WITH CURRENT TEMPERATURES IN THE 40S AND UPSTREAM DEWPOINTS IN THE 20S AREAS WHICH CLEAR OUT LONG ENOUGH SHOULD SEE TEMPERATURES DROP ENOUGH FOR FREEZE CONDITIONS. ISSUED FREEZE WARNING FOR FAR NW BUFFERED BY FROST ADVISORY. EXTENT OF COLDER TEMPERATURES WILL BE DEPENDENT ON AMOUNT OF CLEARING. CLOUDS SHOULD LIMIT COOLING ELSEWHERE. PCPN SHOULD CONTINUE TO WIND DOWN SUNDAY AS SYSTEM CONTINUES TO PROPAGATE EAST AND WEAKEN. SE 1/3RD OF FA WILL SEE BEST POTENTIAL FOR SOME ADDITIONAL -RA MAINLY DURING THE AM. COLUMN NOT VERY COLD SO AREAS WHICH SEE SOME SOLAR SHOULD SEE A MODEST TEMPERATURE RECOVERY. BASED ON THERMAL PROFILES AND LOW LEVEL RH NOT ANTICIPATING ANY FROST/FREEZE CONDITIONS SUNDAY NIGHT BUT WILL NEED TO MONITOR. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 PM CDT SAT OCT 5 2013 WEATHER SETTLES DOWN INTO FIRST HALF OF NEXT WEEK. COLUMN WARMS THROUGH THE PERIOD SO WILL SEE GRADUALLY WARMER CONDITIONS WITH MAXIMUM TEMPERATURES CLIMBING ABOVE AVERAGE. WED-THU PERIOD REMAINS QUIET AS 500 MB RIDGE BUILDS BACK OVER THE GREAT LAKES-OHIO VALLEY WITH LOCAL AREA IN SOUTHWEST FLOW ALOFT. TEMPS LOOK TO RUN ABOVE NORMAL WITH DRY WEATHER. NEXT 500 MB LOW AND ASSOCIATED SFC LOW PROGGED TO MOVE NORTHEAST INTO THE NRN PLAINS FRI-SAT PERIOD. 12Z GFS/ECMWF DIFFER IN STRENGTH AND TRACK OF THIS SYSTEM WITH GFS FARTHER SOUTH AND A BIT WEAKER WHILE EURO STRONGER AND FARTHER NORTH AND WEST. EITHER WAY WILL BRING CHC OF RAIN SHOWERS INTO THE AREA FRI AFTN INTO SATURDAY. EURO WOULD HAVE HIGHER QPF THAN GFS. KEPT IDEA OF ISOLD THUNDER AS WELL FRI AFTN-FRI NIGHT...ESP IF EURO TRACK IS RIGHT AS IT BRINGS UP MORE UNSTABLE AIR VS THE FARTHER SOUTH GFS. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1147 PM CDT SAT OCT 5 2013 THE GENERAL TREND WILL BE IMPROVING CONDITIONS INTO SUNDAY MORNING. CLEARING SKY ACROSS KDVL WILL SLOWLY MOVE EASTWARD...IMPROVING THE IFR/MVFR CONDITIONS ACROSS THE OTHER TAF SITES. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FREEZE WARNING FROM 3 AM TO 9 AM CDT SUNDAY FOR NDZ006-007-014- 015-024. FROST ADVISORY FROM 3 AM TO 9 AM CDT SUNDAY FOR NDZ008-016-026- 054. MN...NONE. && $$ UPDATE...TG SHORT TERM...VOELKER LONG TERM...RIDDLE/VOELKER AVIATION...TG
AREA FORECAST DISCUSSION
NWS TULSA OK
1153 PM CDT SAT OCT 5 2013 .DISCUSSION... THE 06Z TAF DISCUSSION IS INCLUDED BELOW. && .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. VFR CONDITIONS WILL PREVAIL THRU THE PERIOD AT ALL SITES...WITH ONE EXCEPTION. THE LATEST RUC DATA MOISTURE PROFILE SHOWS SOME LINGERING LOW LVL MOISTURE DOWN IN THE LOWER ARK RIVER VALLEY NEAR KFSM...AND INDEED THERE IS SOME EVIDENCE OF THIS BASED ON LATEST OB FROM SALLISAW AND FOG ENHANCED SAT IMAGE SHOWING LOW CLOUDS/FOG IN THE VCNTY. SINCE THIS IS SO CLOSE BY...I HAVE TEMPO`D IN LIFR CONDITIONS TOWARD 12Z. SURFACE WINDS WILL BCM NWRLY AT 10 TO 20 KTS AFT 15Z SUNDAY MORNING. LACY && .PREV DISCUSSION... /ISSUED 942 PM CDT SAT OCT 5 2013/ DISCUSSION... BACK EDGE OF RAIN APPEARS TO FINALLY BE PUSHING OUT OF FAR SOUTHEAST OK AT THIS TIME WITH SKIES CLEARING IN FAIRLY RAPID FASHION AS WELL. COOLEST TEMPS OF THE SEASON THUS FAR EXPECTED WITH SOME SPOTS ALREADY INTO MID 40S AS OF 930 PM. LIGHT SW WIND KEEPING TEMP AT KTUL SEVERAL DEGREES ABOVE SURROUNDING LOCATIONS...HOWEVER SHOULD SEE GRADUAL VEERING TO MORE NW COMPONENT WHICH SHOULD EVENTUALLY NEUTRALIZE URBAN EFFECT. BASED ON RADAR TRENDS WILL BE ABLE TO GO AHEAD AND REMOVE PRECIP FROM TONIGHT`S FORECAST BY 10 PM...AND WILL MAKE SOME MINOR CHANGES TO TEMPS AS WELL. PREV DISCUSSION... /ISSUED 630 PM CDT SAT OCT 5 2013/ DISCUSSION... THE 00Z TAF DISCUSSION IS INCLUDED BELOW. AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. ALL SITES TRENDING TO VFR BY THE START OF THE TAF PERIOD. SOME LINGERING MOISTURE NEAR THE GROUND AT KFSM COULD LEAD TO SOME LIGHT MVFR FOG AROUND 12Z. LIGHT WINDS WILL BECOME NWRLY AT 10 TO 20 KTS AFT 15Z SUNDAY MORNING. LACY PREV DISCUSSION... /ISSUED 326 PM CDT SAT OCT 5 2013/ DISCUSSION... BAND OF ONGOING CONVECTION IS ALIGNED ALONG THE 850MB FRONT...AND GIVEN THE LATEST RUC PROJECTIONS...THIS BOUNDARY WILL BE ACROSS FAR WESTERN AR INTO EXTREME SE OK BY 00Z AND PUSHING EASTWARD. ANY EVENING PRECIP WILL BE CONFINED TO THIS ZONE BEFORE PUSHING FURTHER EASTWARD AND CLEAR OF THE FORECAST AREA. SKIES WILL CONTINUE TO CLEAR FROM NW TO SE AND ALLOW FOR A COOL SUNDAY MORNING. BREEZY NORTHWEST WINDS WILL DEVELOP SUNDAY WHILE TEMPERATURES REMAIN BELOW SEASONAL NORMALS. WINDS WILL DROP OFF AROUND SUNSET AND ALLOW TEMPS TO FALL QUICKLY. A SEVERAL DAY WARMING TREND COMMENCES MONDAY WITH TEMPS RETURNING TO ABOVE NORMAL READINGS BY MID WEEK. THE WARM AND DRY WEATHER WILL PREVAIL INTO THE WEEKEND WHEN THE NEXT STORM SYSTEM PUSHES INTO THE PLAINS. WILL INTRODUCE LOW PRECIP CHANCES FOR NEXT WEEKEND PENDING THE EVOLUTION OF THIS SYSTEM. && .PRELIMINARY POINT TEMPS/POPS... TUL 46 70 45 75 / 0 0 0 0 FSM 46 71 46 75 / 10 0 0 0 MLC 43 72 43 77 / 10 0 0 0 BVO 40 69 40 75 / 0 0 0 0 FYV 41 65 39 70 / 10 0 0 0 BYV 43 63 44 69 / 10 0 0 0 MKO 42 70 42 75 / 10 0 0 0 MIO 42 66 42 72 / 0 10 0 0 F10 43 71 44 76 / 0 0 0 0 HHW 47 76 44 79 / 10 0 0 0 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && $$ AVIATION...30
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1247 AM MDT SUN OCT 6 2013 .SHORT TERM...THIS EVENING THROUGH SUNDAY NIGHT ISSUED AT 301 PM MDT SAT OCT 5 2013 THE STORM CONTINUES TO WIND DOWN SLOWLY FOR THE BLACK HILLS REGION THIS AFTERNOON. A STRONG CLOSED LOW OVER EASTERN SOUTH DAKOTA IS MAKING A LITTLE PROGRESS EASTWARD THIS AFTERNOON. THE RESULT FOR THE WESTERN HALF OF THE STATE IS DECREASING SNOWFALL AND WIND AS THE WEAKENING BAND OF PRECIPITATION AND STRONG WIND SHFTS EASTWARD. THE 18Z HRRR SHOWS THE SURFACE LOW CENTER WEAKENING RAPIDLY AND REFORMING OVER MINNESOTA DURING THE NEXT SEVERAL HOURS. AS THE SYSTEM MOVES INTO CENTRAL SOUTH DAKOTA BOTH THE PRECIPITATION RATE AND DURATION OF STRONG WINDS ARE EXPECTED TO DECREASE RESULTING IN A LESS POTENT EVENT IN THOSE PARTS. A MUCH WELCOME DAY OF BLUE SKIES AND SUNSHINE ARE IN STORE FOR SUNDAY AS A TRANSITORY HIGH PRESSURE RIDGE SHIFTS INTO THE HIGH PLAINS. GUIDANCE WARMING SEEMS A LITTLE TOO AGGRESSIVE CONSIDERING THE EXTENSIVE SNOWPACK WE`VE ACQUIRED SO TEMPS WERE TRIMMED DOWN A BIT. THIS IS BETTER THAN A RAPID MELTOFF ANYWAY. WILL HAVE TO KEEP AN EYE ON HOW THE STREAMS RESPOND OVER THE NEXT COUPLE OF DAYS. THE MILD SUNNY WEATHER IS FORECAST TO CONTINUE MONDAY AS THE RIDGE LINGERS OVER THE REGION. && .LONG TERM...MONDAY THROUGH SATURDAY ISSUED AT 301 PM MDT SAT OCT 5 2013 PROGRESSIVE LONG WAVE RIDGE BUILDS IN BEHIND THE RECORD-BREAKING BLIZZARD... MOVING QUICKLY FROM NEAR 110W ON MON TO JUST E OF 100W ON TUE AND TO 85W ON WED. AS IT DOES SO...A NEW LONG WAVE TROF IS CARVED OUT IN THE WEST. GFS CONTINUES TREND OF LAST SEVERAL RUNS IN SPLITTING OFF A NRN STREAM SHORT WAVE AND MOVING IT ACROSS WRN CAN WHILE THE STRONGER PORTION OF THE WAVE DIGS S WARD INTO CA. BY 12Z WED A CLOSED LOW IS SHOWN OVER NRN CA. THE DIGGING PROCESS IS COMPLETED BY THU AT 12Z AND THE LOW IS FCST TO MOVE OUT TO THE NE...PERHAPS TO SE SD BY 12Z SAT. THIS RUN OF GFS IS SLIGHTLY FARTHER S AND E THAN YESTERDAY`S. WHILE THE TRACK IS REMINISCENT OF OUR PRESENT STORM...1000 TO 500MB THICKNESSES ARE PRESENTLY FCST TO BE WELL ABOVE SNOW RELATED VALUES AND THE UPPER LOW IS FAR LESS INTENSE. BUT IT IS EARLY IN THE GAME. ACCEPTED THE EXTENDED INIT TEMPS...THOUGH THEY ARE MUCH BELOW GFS MOS GUIDANCE FOR WED AND THU. THINKING IS THAT THERE WILL STILL BE SOME WET GROUND FROM THE HEAVY SNOW AND THAT THE STORM-FOLLOWING RIDGE IS FCST TO MOVE E WARD SO QUICKLY THAT UPPER LEVEL COOLING WILL ALREADY BE UNDERWAY AS THE TROF IN THE W INTENSIFIES AND APPROACHES THE AREA. CLOUDS...POPS...AND PRECIP BROUGHT IN THU NIGHT INTO SAT IN LINE WITH APPROACHING CLOSED LOW. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1242 AM MDT SUN OCT 6 2013 AN APPROACHING HIGH PRESURE RIDGE....A WEAK PRESSURE GRADIENT AND A MOSTLY DRY AIRMASS ALOFT WILL COMBINE TO PRODUCE VFR CONDITIONS AREA WIDE DURING THE FORECAST PERIOD. NO OBSERVATIONS HAVE BEEN AVAILABLE SINCE FRIDAY AFTERNOON FROM KRAP DUE TO COMMUNICATIONS ISSUES. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...NONE. WY...NONE. && $$ SHORT TERM...CARPENTER LONG TERM...BARBER AVIATION...CARPENTER
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1133 PM CDT SAT OCT 5 2013 .DISCUSSION... SEE AVIATION FOR THE 06Z TAF DISCUSSION. && .AVIATION... THE COLD FRONT HAS MOVED SOUTH OF SOUTH CENTRAL TEXAS WITH ASSOCIATED THUNDERSTORMS LOCATED OVER THE BRUSH COUNTRY. THESE STORMS WILL NOT HAVE AN IMPACT ON OUR TERMINALS. HOWEVER A SW TO NE BAND OF ELEVATED POST-FRONTAL SHOWERS EXTENDED FROM NEAR KDRT TO KLZZ. THE BAND IS MOVING EAST WHILE THE INDIVIDUAL CELLS ARE MOVING NORTHEAST. WE WILL USE THE LATEST RUC13 TO TIME THE ARRIVAL OF THE SHOWERS AT THE I-35 TERMINALS. VFR CONDITIONS WILL PREVAIL OVERNIGHT WITH MVFR IN AND AROUND THE SHOWERS. THE SHOWERS WILL MOVE ACROSS THE I-35 TERMINALS BETWEEN 07Z AND 11Z. SFC WINDS OVERNIGHT WILL BE NORTHERLY AT 10 TO 20 KTS. SHOWERS WILL BE SOUTHEAST OF THE TERMINALS ON SUNDAY WITH VFR CONDITIONS PREVAILING. SFC WINDS WILL BE NORTH AT 10 TO 15 KTS...DIMINISHING AFTER SUNSET. && .PREV DISCUSSION... /ISSUED 933 PM CDT SAT OCT 5 2013/ UPDATE... COLD FRONT HAS FINALLY MOVED SOUTH OF SOUTH CENTRAL TEXAS. SHOWERS ARE NOW DEVELOPING AHEAD OF AN UPPER LEVEL TROUGH AND IN FAVORABLE JET QUADRANT. AREAL COVERAGE OF SHOWERS INCREASES TOWARD MIDNIGHT AS UPWARD FORCING STRENGTHENS AND THEN SLOWLY DECREASES TOWARD MORNING AS UPWARD FORCING WEAKENS. HAVE GONE WITH SAME POPS ALL OF TONIGHT. DUE TO MINIMAL INSTABILITY HAVE REDUCED THUNDERSTORMS TO SLIGHT CHANCE. UPPER LEVEL FEATURES ARE A LITTLE SLOWER AND HAVE ADDED SLIGHT CHANCE SHOWERS FOR A LITTLE PAST SUNRISE ON SUNDAY ACROSS SOUTHERN AREAS. HAVE ALSO RE-ESTABLISHED TRENDS TO SENSIBLE WEATHER GRIDS BASED ON SURFACE OBSERVATIONS. PREV DISCUSSION... /ISSUED 617 PM CDT SAT OCT 5 2013/ DISCUSSION... SEE AVIATION FOR THE 00Z TAF DISCUSSION. AVIATION... AT 23Z THE COLD FRONT EXTENDED FROM K11R TO KBAZ TO KUVA TO KFTN. THE FRONT WAS MOVING SE AT 10 TO 15 MPH. SFC BASED CONVECTION WILL OCCUR OVER THE COASTAL PLAINS THIS EVENING WHEN THE COLD FRONT COLLIDES WITH THE SEA-BREEZE BOUNDARY. ELEVATED POST-FRONTAL SHOWERS WILL OCCUR OVERNIGHT WITH THE APPROACH OF THE UPPER LEVEL TROF. THE ELEVATED SHOWERS MAY IMPACT THE I-35 TERMINALS...SO HAVE USED THE 22Z RAP13 MODEL FOR TIMING. VFR CONDITIONS WILL PREVAIL WITH MVFR CONDITIONS POSSIBLE BETWEEN 07Z AND 09Z IN AND AROUND THE POST-FRONTAL SHOWERS. SFC WINDS WILL BE NORTHERLY AT 10 TO 15 KTS BEHIND THE COLD FRONT. PREV DISCUSSION... /ISSUED 309 PM CDT SAT OCT 5 2013/ SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)... COLD FRONT CURRENTLY PUSHING THRU THE NRN CWA WITH A FINE LINE EVIDENT ON RADAR. POST FRONTAL OVERRUNNING CONVECTION WAS DEVELOPING WELL TO THE NW ACROSS THE BIG COUNTRY INTO THE EDWARDS PLATEAU REGION. AS THE COLD FRONT CONTINUES SEWD THRU THE CWA THIS EVENING...WILL SEE SCATTERED TO NUMEROUS SHOWERS/ISOLD STORMS DEVELOP BEHIND THE FRONTAL BOUNDARY AHEAD OF THE MID LEVEL TROUGH OVER WEST TEXAS. COLD AIR ADVECTION PREVAILING OVERNIGHT...AND THE DRIER LOW LEVEL AIR SHOULD LIMIT AVERAGE QPF AMOUNTS TO ONE QUARTER INCH OR LESS OVER THE SWRN CWA TO ONE TENTH INCH OVER EAST AND NE. CONVECTION WILL END FROM THE NORTH SUNDAY MORNING AS THE TROUGH AXIS SLIDES SEWD ACROSS THE CWA. SUNNY BREEZY AND COOLER SUNDAY. MUCH COOLER SUNDAY NIGHT WITH MIN TEMPS APPROACHING 40 DEGREES IN THE HILL COUNTRY BY DAYBREAK...UNDER CLEAR SKIES WITH IDEAL RADIATIONAL COOLING. LONG TERM (MONDAY THROUGH SATURDAY)... A GRADUAL WARMING TREND FOR THE WORK WEEK AS SLY WINDS RESUME MONDAY NIGHT INTO TUESDAY AND PREVAIL FOR THE REST OF THE WEEK. A HIGH PRESSURE RIDGE WILL GENERALLY PREVAIL ALOFT AS A LOW DIGS SWD ALONG THE WEST COAST. ALTHOUGH LOW LEVEL MOISTURE WILL RETURN BY WEDNESDAY...THE UPPER RIDGE SHOULD SUPPRESS ANY CHANCES FOR RAIN. THE DRY LINE COULD GENERATE ISOLATED STORMS IN WEST TX LATE IN THE WEEK AS THE UPPER LOW KICKS OUT ACROSS THE GREAT BASIN AND ACROSS THE SOUTH CENTRAL ROCKIES. A FEW STORMS COULD APPROACH THE FAR WESTERN CWA THU THRU SATURDAY...BUT WILL LEAVE POPS AS SILENT 10S FOR NOW. WITH THE LONG RANGE MODELS LIFTING THE UPPER LOW FURTHER NORTH LATE NEXT WEEK...IT APPEARS THE CHANCES FOR A COLD FRONT INTO THE AREA HAVE DIMINISHED AS THE FRONT STALLS NORTH OF THE AREA. THEREFORE HAVE KEPT TEMPERATURES ABOVE NORMAL LATE IN THE WEEK/SATURDAY...BUT HAVE KEPT IN SLIGHT RAIN CHANCES CROSS-SECTIONS SHOW A SURGE OF DEEPER MOISTURE INTO SOUTH TEXAS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 56 82 52 85 55 / 40 - 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 55 81 47 86 51 / 40 - 0 0 0 NEW BRAUNFELS MUNI AIRPORT 55 81 48 87 53 / 40 - 0 0 0 BURNET MUNI AIRPORT 53 79 47 84 53 / 40 - 0 0 0 DEL RIO INTL AIRPORT 56 81 52 86 55 / 20 - 0 0 0 GEORGETOWN MUNI AIRPORT 55 81 48 85 53 / 40 - 0 0 0 HONDO MUNI AIRPORT 56 83 47 88 53 / 50 - 0 0 0 SAN MARCOS MUNI AIRPORT 55 79 48 86 53 / 40 - 0 0 0 LA GRANGE - FAYETTE REGIONAL 60 83 51 85 52 / 20 - 0 0 0 SAN ANTONIO INTL AIRPORT 56 82 52 87 56 / 50 - 0 0 0 STINSON MUNI AIRPORT 57 83 51 87 55 / 50 - 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...13 SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
327 AM CDT SUN OCT 6 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT SUN OCT 6 2013 FORECAST A BIT MORE QUIET THAN PREVIOUS DAYS WITH LOW IMPACT WEATHER THROUGH THE PERIOD. A BIT OF A CHALLENGE WITH THE LONGWAVE LOW SHIFTING ACROSS THE REGION AND THE WRAP AROUND MOISTURE COMING IN LATE TODAY AND OVERNIGHT. WATER VAPOR IMAGERY LOCATES THE CENTER OF THE 300-500MB CIRCULATION EAST OF KSUX IOWA WITH A SLOW DRIFT EAST. REGIONAL RADARS ARE INDICATING WRAP AROUND MOIST PLUME CONTINUING FROM KINL-KFAR-KABR- CENTRAL NEBRASKA WITH RAINFALL OF .03 TO .08 PER HOUR IN THE BAND. CLOUDS ARE LOW TOO...SO A WELL SATURATED ENVIRONMENT. PER RAP ANALYSIS...GOOD CORRELATION WITH THE 305-308 THETA-E SURFACE AND FLOW UP THE SURFACE WITHIN THE MOIST PLUME / TROWAL. ANOTHER DEFORMATION BAND CLOSER TO THE LOW CENTER ITSELF IS FOUND IN NW IA WITH A FEW HUNDREDTHS PER HOUR THERE. THESE ARE PLAYERS FOR THE OVERNIGHT FORECAST. AT 3 AM...DRY SLOT AND CLEAR SKIES RUNNING THROUGH MOST OF THE FORECAST AREA...BUT LOWER CLOUD NOW MOVING SLOWLY EAST TOWARD MISS RIVER IN NERN IA AND SERN MN. SOME PATCHY FOG MAY BE AROUND WITH LIGHT WIND IN THE CLEAR SECTOR THIS MORNING AS DEWPOINT DEPRESSIONS ARE NEAR ZERO. THE LOW WILL SHIFT EAST TODAY AND THE CONSENSUS MODEL SOLUTIONS TRACK IT THROUGH THE QUAD CITIES OR A BIT NORTH. THIS PLACES THE NORTHERN SIDE OF THE LOW OVER THE SOUTHERN FORECAST AREA. LOW- LEVEL LAPSE RATES ARE PRETTY STEEP BY LATER AFTERNOON /7.5-8.5 C PER KM/ AS THIS OCCURS AND WITH CIRCULATION CENTER SO CLOSE...THINKING SCT SHOWERS WILL DEVELOP ACROSS THE SOUTH THIS AFTERNOON. THIS ALSO COMBINES WITH LIFT UP THE THETA-E SURFACES IN THAT AREA AND A SPOKE OF SHORTWAVE TROUGH ENERGY WORKING NORTH AROUND THE LOW. THIS SCT SHOWERS AREA WILL EXTEND BACK TOWARD THE WEST WHERE MAIN MOIST PLUME WILL BE INCOMING. TONIGHT...GOOD CONSENSUS ON DRAGGING THE WRAP AROUND RAIN BAND THROUGH THE AREA. SOUNDINGS ACROSS THE MODELS ARE SATURATED...SOME VERY SATURATED FROM 0-3KM. FORCING REMAINS THAT TROWAL AIR STREAM WITH THETA-E SURFACE LIFT RISING AS THE PARCEL MOVE SOUTH. ALTHOUGH WEAKER FORCING THAN CURRENTLY OUT WEST...THE 06.00Z GFS HAS 7 UB/S OF LIFT FROM 0-3KM AT KLSE AT 06Z AND THE LAYER IS TOTALLY SATURATED. THUS...HAVE PUT IN SCATTERED SHOWERS OVERNIGHT TO ACCOUNT FOR THIS...BUT THINKING THAT OUR RAIN CHANCES MAY BE TOO LOW. DAY SHIFT MAY NEED TO BUMP THE RAIN CHANCES. THE LOW MOVES EAST MONDAY AND WITH IT THE RAIN CHANCES AND THE CLOUDS. VERY LITTLE CHANGE TO THE TEMPERATURES FOR THE FORECAST CYCLE - VERY NEAR TO PREVIOUS FORECAST. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 AM CDT SUN OCT 6 2013 PRETTY QUIET PERIOD OVERALL WITH LONGWAVE RIDGE BUILDING OVER THE MIDWEST AS THE LONGWAVE TROUGH DIGS INTO THE SOUTHWEST U.S. THE GFS ENSEMBLES ARE IN GOOD AGREEMENT ON THE 500MB PATTERN THROUGH ABOUT THURSDAY WHICH DEFINES THE DIGGING OF THE LONGWAVE TROUGH OUT WEST. THE ENSEMBLES AND THE DETERMINISTIC ECMWF 05.12Z/06.00Z AND 06.00Z GEM/GFS SOLUTIONS DIVERGE ON HOW THAT TROUGH ENERGY LIFTS NORTHEAST TOWARD THE GREAT LAKES AND DAKOTAS FOR NEXT WEEKEND. OVERALL IT WILL BE A VERY MILD WEEK WITH ABOVE NORMAL TEMPERATURES AND SOUTHERLY FLOW UNDER THE RIDGE. BY LATE NEXT WEEK...THUNDERSTORMS CHANCES MOVE INTO THE FORECAST AS THE TROUGH EJECTS NORTHEAST. OVERALL...THERE ARE TIMING DIFFERENCES AND PREFER THE SLIGHTLY MORE STABLE ECMWF FAMILY OF SOLUTIONS FOR SLOWER TIMING. BOTTOM LINE IS THUNDERSTORM CHANCES LATE WEEK AFTER A WARM SUNNY WEEK. NOT SURE THERE IS EVEN A FROST OR VALLEY FOG DAY IN THERE WITH THE CLEAR SKIES PREDICTED BECAUSE THE SOUTHERLY FLOW KICKS IN SO RAPIDLY. ONLY FROST TIME FRAME IS POSSIBLY TUESDAY MORNING IN CENTRAL WISCONSIN IF THE SOUTHERLY FLOW DOESNT KICK IN FAST ENOUGH. A CALM MONDAY EVENING AND RAPID COOL DOWN WOULD SEEM TO SUGGEST LOWS IN THE UPPER 30S....WITH LIGHT SOUTH WINDS KICKING IN AFTER MIDNIGHT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT) ISSUED AT 1147 PM CDT SAT OCT 5 2013 CLEAR SLOT OVER BOTH TAF SITES THIS EVENING BUT CLOUDS IN THE DEFORMATION AREA ARE MAKING STEADY EASTWARD PROGRESS. EXPECT THESE WILL SPREAD OVER KRST OVERNIGHT WITH A VFR CEILING. STILL A THREAT FOR FOG TO FORM AT KLSE IF THE CLOUDS HOLD OFF UNTIL SUNRISE OR AFTER. THE RAP RUNS THROUGH THE EVENING HAVE BEEN SUGGESTING THE FORMATION OF SOME MVFR VISIBILITIES IN THE EVENING...BUT OPTED TO STAY WITH BCFG AS THERE WAS STILL AN 11F TEMP/DEW POINT SPREAD AT 04Z. CLOUDS SHOULD THEN SPREAD OVER KLSE BY MID MORNING. SOME SHOWERS REMAIN POSSIBLE IN THE DEFORMATION BAND OVER SOUTHEAST MINNESOTA AND WILL CONTINUE TO SHOW A VCSH AT KRST FOR THE AFTERNOON. CEILINGS AT KRST HAVE THE POTENTIAL TO GO DOWN TO MVFR SUNDAY EVENING. THESE CEILINGS ARE CURRENTLY IN PLACE OVER NORTHERN MINNESOTA AND AS THE UPPER LEVEL SYSTEM MOVES SOUTHEAST AWAY FROM THE AREA...THE 06.00Z NAM INDICATES THESE LOWER CEILINGS WILL MOVE INTO THE REGION. COULD STILL BE A FEW SHOWERS AROUND SUNDAY EVENING AS WELL...BUT CONFIDENCE IS NOT HIGH ENOUGH TO EVEN INCLUDE A VCSH AT THIS POINT. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM...BAUMGARDT AVIATION...04
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
741 AM EDT SUN OCT 6 2013 .SYNOPSIS... HIGH PRESSURE OVER THE REGION WILL WEAKEN AND MOVE OFFSHORE THROUGH TONIGHT. A COLD FRONT WILL CROSS THE AREA MONDAY AND MONDAY NIGHT WITH BROAD HIGH PRESSURE THEN BUILDING IN FROM THE NORTHWEST AND PERSISTING THROUGH NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... NEAR-DAWN...DENSE FOG WAS LIFTING INLAND IN SE COASTAL SOUTH CAROLINA SLOWLY THIS MORNING AS A LOW LEVEL MARITIME PUSH WAS UNDERWAY. FOG HAS CLEARED OUT OF NORTH CHARLESTON BUT THAT WAS THE EXCEPTION RATHER THAN THE NORM AS DENSE FOG AND WIDESPREAD STRATUS BLANKET MOST AREAS INLAND FROM U.S. HIGHWAY 17. FAR INLAND AREAS MAY NEED BRIEF EXTENSION TO THE ADVISORY UNTIL 10 AM PER LATEST HRRR AND SREF MODEL TRENDS. DEEP LAYERED RIDGING WILL CONTINUE AN EROSION PHASE AS UPPER HEIGHT FALLS UPSTREAM BUILD IN RESPONSE TO THE DEEP CUT-OFF SYSTEM OVER THE UPPER PLAINS DIGGING TOWARD THE OHIO VALLEY REGION. THE AIR MASS OVER THE FORECAST AREA STARTS OFF DRY UPSTAIRS BUT MODELS INDICATE DEEPER MOISTURE ADVECTION FROM THE ATLC TODAY WITH 2 INCH PWATS GETTING INTO SW GEORGIA BY DUSK. LAYERED CUMULUS AND STRATOCU FIELDS SHOULD INCREASE TODAY...ESPECIALLY THIS AFTERNOON AS ISENTROPIC LIFT BEGINS TO INCREASE. THERE IS STILL A GOOD SUBSIDENCE CAP NOTED ON SOUNDINGS THIS AFTERNOON AND ENOUGH INSTABILITY WILL BE AROUND TO GENERATE SOME CONVECTIVE RAINS. SEVERAL MODELS GENERATE DEEP CONVECTION INLAND FROM THE SEA BREEZE LATER THIS AFTERNOON BUT WE FOUND THAT DIFFICULT TO BUY INTO GIVEN VERY POOR MID LEVEL LAPSE RATES AND THE LINGERING WARM LAYER BETWEEN 700 MB AND 500 MB. WE MAINTAINED 20/30 POP THIS AFTERNOON WITH WARM HIGHS IN THE MID 80S WITH A FEW UPPER 80S W OF I-95 POSSIBLE IF GREATER INSOLATION OCCURS. CLOUDS WILL LOWER AND THICKEN TONIGHT AS A COLD FRONT APPROACHES FROM THE WEST AND UPPER FORCING FOR ASCENT INCREASES OVER THE AREA. DEEP MOISTURE AND UPPER DIFLUENCE SHOULD ALLOW SCATTERED CONVECTIVE RAINS TO BLOSSOM OVER THE ENTIRE AREA BY DAYBREAK. REGIONAL SOUNDINGS INDICATE SOME STRONG SHEAR PROFILES BRUSHING THE REGION LATE TONIGHT AND A FEW CONVECTIVE ELEMENTS COULD PRODUCE ROTATION DURING THE LATE NIGHT HOURS. THE RISK FOR ISOLATED SEVERE WEATHER MAY BE ON AN UPTICK IF INSTABILITY PARAMETERS ARE THERE. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... THE GOOD NEWS IS THAT TROPICAL CYCLONE KAREN IS NO LONGER EXPECTED TO HAVE AN APPRECIABLE IMPACT ON OUR AREA. THE MAIN FEATURE THIS PERIOD IS A COLD FRONT MOVING IN FROM THE WEST. DEEP SOUTHERLY FLOW AHEAD OF THE FRONT ON MONDAY WILL PUSH PWATS ABOVE 2 INCHES. AT UPPER LEVELS AN 80 KT JET STREAK WILL MOVE ACROSS THE SOUTHEAST STATES WITH SOME ACCOMPANYING DIVERGENCE. DECENT VORTICITY ENERGY WILL CROSS THE AREA MONDAY ALONG WITH THE COLD FRONT...THEN THE BEST FORCING WILL SHIFT OFF THE COAST MONDAY NIGHT. PRECIPITATION IS PRETTY MUCH A CERTAINTY ON MONDAY SO WE BUMPED POPS INTO THE CATEGORICAL RANGE BY EARLY AFTERNOON. INSTABILITY PARAMETERS SUPPORT SOME THUNDERSTORMS ON MONDAY. SHEAR WILL BE DECREASING AS THE DAY WEARS ON BUT A FEW STORMS WILL BE CAPABLE OF DOWNING A TREE OR TWO. DRY CANADIAN HIGH PRESSURE WILL SLOWLY FILTER IN FROM THE NORTHWEST TUESDAY...PUSHING THE PRECIP OFF THE COAST BY LATE MORNING. THE AIRMASS WILL BE MUCH COOLER THAN THE ONE IT REPLACES. WE LOWERED HIGH TEMPS QUITE A BIT ON TUESDAY IN RESPONSE TO GUIDANCE TRENDS. WE NOW SHOW READINGS TOPPING OUT IN THE MIDDLE 70S. CLOUD COVER WILL DIMINISH TUESDAY NIGHT AND WEDNESDAY WITH HIGH PRESSURE BECOMING FIRMLY ENTRENCHED ALONG THE EASTERN SEABOARD. TUESDAY NIGHT LOWS WILL BE IN THE 50S AND HIGHS WEDNESDAY WILL AGAIN BE IN THE MID TO UPPER 70S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... DEEP LAYERED RIDGING WILL DOMINATE THE PATTERN IN THE EXTENDED RANGE. REINFORCING CANADIAN HIGH PRESSURE WILL MAINTAIN BELOW NORMAL TEMPS WITH LOWS IN THE MID/UPPER 50S AND HIGHS IN THE UPPER 70S WITH MAINLY DRY CONDITIONS. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... KCHS...FOG APPEARS TO BE DONE FOR THE DAY AS ATTENTION TURNS TO MVFR LAYER POTENTIAL FOR A WHILE THIS MORNING AND LOWER CIGS AGAIN TONIGHT. WE WILL NOT HAVE TO DEAL WITH DENSE FOG FOR THE 4TH CONSECUTIVE NIGHT AS A STRONG LOW LEVEL JET WILL KEEP THE LOWER ATMOSPHERE MIXING. THERE IS STILL GOOD CHANCES FOR MVFR OR IFR CIGS TONIGHT AS MOISTURE BECOMES DEEP. LATER TAF CYCLES CAN REFINE RAIN CHANCES/TIMING TONIGHT...FOR NOW A VCSH AFTER MIDNIGHT. KSAV...THE FOG IS STILL DENSE AT THE TERMINAL AT 1130Z BUT IS EXPECTED TO DISSIPATE AROUND 13Z AND NO LATER THAN 14Z. THIS AFTERNOON...CLOUDS WILL INCREASE WITH A SLIGHT CHANCE OF SHOWERS BUT MOST LIKELY VFR CIGS. TONIGHT...MVFR OR EVEN IFR CIGS WILL RETURN BUT NOT THE DENSE FOG AS A STRONG LOW LEVEL JET IS FORECAST TO DEVELOP. RAIN CHANCES WILL BE INCREASING LATE BUT VCSH WILL BE THE INTRODUCTION ON THE 12Z CYCLE. EXTENDED AVIATION OUTLOOK...CEILINGS WILL OCCASIONALLY DROP TO MVFR OR PERHAPS IFR MONDAY AND MONDAY NIGHT DUE TO SHOWERS ALONG A COLD FRONT. VFR THEREAFTER. && .MARINE... LIGHT E WINDS WILL INCREASING SLOWLY THIS AFTERNOON AND VEERING SE TONIGHT INCREASING TO 15 KT AND EVEN NEAR 20 KT AT TIMES OVER OUTER GEORGIA WATERS AFTER MIDNIGHT. SEAS WILL BUILD FROM 2 FT OR LESS THIS MORNING TO 3 TO 4 FT TONIGHT WITH WAVES TO 5 FT OVER OUTER GEORGIA WATERS IN FAVORABLE ESE FETCH OFF THE WEST WALL OF THE GULF STREAM. AN INCREASE IN SOUTHERLY WINDS ON MONDAY AHEAD OF THE COLD FRONT MAY RESULT IN A BRIEF PERIOD OF SOME 6 FT SEAS ACROSS OFFSHORE PORTIONS BUT THERE IS NOT ENOUGH CONFIDENCE TO PROMPT ANY ADVISORIES. THE BETTER CHANCE FOR MARINE HEADLINES BEGINS TUESDAY AS CANADIAN HIGH PRESSURE BUILDS IN...THE FLOW BECOMES NNE AND THE GRADIENT PINCHES. SMALL CRAFT ADVISORIES ARE LIKELY BY TUESDAY AFTERNOON IN MOST IF NOT ALL OF THE MARINE ZONES...PRIMARILY DUE TO 6+ FT SEAS. THESE CONDITIONS LOOK TO CONTINUE INTO THURSDAY OR FRIDAY THOUGH WINDS/SEAS WILL SLOWLY BE DIMINISHING. && .TIDES/COASTAL FLOODING... ASTRONOMICAL HIGH TIDES MAY COMBINE WITH MODERATE NORTHEAST WINDS BEGINNING TUESDAY TO PRODUCE SOME MINOR SALTWATER INUNDATION IN LOW-LYING AREAS NEAR THE COAST AROUND THE TIMES OF THE LATE MORNING HIGH TIDES. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR GAZ087-088- 099>101-114>116-118-137-138-140. SC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ040- 042>045-047>052. MARINE...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...JRL LONG TERM...JRL AVIATION... MARINE...JRL TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
644 AM EDT SUN OCT 6 2013 .SYNOPSIS... A STATIONARY FRONT...CURRENTLY NEAR THE NEW YORK PENNSYLVANIA BORDER...WILL GRADUALLY LIFT NORTH AS A WARM FRONT TODAY. THIS WILL KEEP OUR WEATHER UNSETTLED WITH SCATTERED SHOWERS AND THUNDERSTORMS. A STRONG COLD FRONT WILL CROSS THE REGION ON MONDAY WITH MORE SHOWERS AND THUNDERSTORMS ALONG WITH THE POSSIBILITY OF HEAVY RAIN. HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY WITH FAIR WEATHER EXPECTED TO CONTINUE THROUGH THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... S/WV...MOST EVIDENT IN THE 700 MB WIND FIELD OVER WRN NY...AND NEARLY STNRY FNTL BNDRY ACRS THE TWIN TIERS...HELPING TO TRIGGER SCT SHRA/TSRA ACRS THE FCST AREA. RUC INDICATES THAT ANOTHER WEAK S/WV OVER SW PA WILL MAKE A RUN TWDS THE SRN TIER TWDS MRNG WHICH MAY TRIGGER MORE SCT ACTIVITY. 925-850 RH`S SUGGEST THE CNTRL SRN TIER AND FINGER LAKES BREAK OUT THIS AFTN (ALSO PORTIONS OF NE PA) LOW CLD AND COOLER TEMPS XPCTD ACRS ERN ZONES...PRIMARILY THE CATSKILLS...ERN SUSQ RGN AND WRN MOHAWK VLY WHERE MOIST LOW LVL SELY FLOW HELPS KEEP MSTR LOCKED IN. INTERESTINGLY..THE LCL WRF SUGGESTS THAT DIFF HEATING DUE TO THESE CLDS MAY HELP TO TRIGGER SCT TSRA OVER THE FINGER LAKES AND CNTRL SRN TIER THIS AFTN. WILL KEEP HIEST POPS ACRS NRN ZONES TDA...WITH MAXES FROM THE U70S WRN ZONES TO M/U60S ACRS PORTIONS OF THE CATSKILLS. A RELATIVE LACK OF PCPN IS XPCTD TNGT. PROFILES SUGGEST THAT SELY FLOW WILL ADVECT LOW CLDS/STRATUS BACK INTO THE FCST AREA OVRNGT. LOWS WILL BE VERY MILD...FROM THE MID AND PSBLY U60S ACRS THE FINGER LAKES...TO AROUND 60 IN FAR EAST. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... SIG CHGS MADE TO THE SHORT TERM GIVEN GOOD AGREEMENT BETWEEN THE 00Z GFS AND 12Z EURO...WHICH ADVERTISED A QUICKER PROGRESSION OF THE FNT/UPR TROF THRU THE FCST AREA. LOOKING AT WATER VAPOR IMAGERY THIS MRNG...IT APPEARS LIKELY THAT NRN STREAM S/WV WILL GIVE THIS SYSTEM A NUDGE AND KEEP IT PROGRESSIVE AS IT MOVS NEWD. THEREFORE WE SPED UP THE FNTL TIMING...XPCTNG IT TO PASS ON MONDAY. THIS WILL REDUCE THE POTNL FOR FLOODING PRBLMS...BUT WITH PW`S IN THE 1.5 TO 1.75 RNG...+RA WILL BE PSBL IN ADDITION TO EMBEDDED TSRA. TEMPS LIKELY TO BE FALLING SPCLY W OF I-81 DURING THE AFTN POST FROPA. POTNL FOR SOME -SHRA ACRS FAR NRN ZONES DUE TO LINGERING EFFECTS OF THE UPR TROF AND NW FLOW. HI PRES WILL BUILD INTO THE REGION FROM THE OH VLY/GTLAKES ON TUE...WITH MRNG CLDS GIVING WAY TO A MOSTLY SUNNY DAY AS RIDGING OCCURS. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... 3 AM UPDATE... HIPRES BOTH AT THE SFC AND ALOFT WL KEEP THE LONG TERM QUIET. HV GONE COMPLETELY DRY TO START OFF THE EXTNDD PD WITH BOTH GFS COMING INTO LINE WITH THE FASTER EURO IN BUILDING THE RIDGE IN BY TUE AND WELL-ESTABLISHED BY WED. STILL EXPECTING TEMPS TO START OFF SEASONAL AND THEN SLOWLY MODERATE THRU THE END OF THE WEEK. PREV DISCUSSION BLO... 240 PM EDT UPDATE... A MUCH DRIER WEATHER PATTERN IS EXPECTED IN THE EXTENDED THAN IN THE NEAR TERM. THE UPR LVL TROUGH THAT WILL BRING SHOWERS AND THUNDERSTORMS OVER THE NEXT COUPLE OF DAYS WILL PUSH OUT OF THE AREA TUESDAY/TUESDAY NIGHT. IN ITS WAKE AN UPPER AND LOWER LVL RIDGE WILL BUILD INTO THE REGION. THERE WILL STILL BE A SLIGHT CHANCE FOR SHOWERS ON TUESDAY/TUESDAY NIGHT FROM LINGERING MOISTURE OF KAREN BUT WILL DIMINISH QUICKLY THEREAFTER. WENT CLOSELY WITH WPC GUIDANCE AND KEPT THE FORECAST DRY AS CHANCES FOR RAIN ARE VERY MINIMAL THROUGH THE EXTENDED. HIGH TEMPS STARTING WED THROUGH SAT WILL BE MUCH COOLER AS WELL... WITH HIGHS REMAINING IN THE MID TO UPPER 60S EVEN THOUGH CLOUD COVERAGE WILL BE FOR THE MOST PART PARTLY CLOUDY. THESE TEMPS WILL BE CLOSER TO THE SEASONABLE NORM BUT ARE STILL ABOVE AVERAGE. COOLER TEMPS ARE AHEAD. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... 12Z UPDATE... FRONTAL BOUNDARY CONTINUES TO SIT ACROSS THE AREA LEADING TO MVFR/IFR CONDITIONS THIS MORNING. POTENTIAL EXISTS FOR KBGM TO DROP BELOW AIRFIELD MINIMUMS BETWEEN 12Z AND 13Z. RESTRICTIONS SHOULD RISE TO VFR/MVFR AFTER 15Z THIS MORNING, WITH VFR AT KAVP AND MVFR AT NY TERMINALS ALONG AND JUST NORTH OF FRONTAL BOUNDARY. AREA OF SHOWERS IS MOVING NORTHEAST THIS MORNING AND SHOULD IMPACT KELM AND KITH BETWEEN 12Z AND 13Z THEN MOVING INTO KSYR/KRME TERMINALS BETWEEN 13Z AND 15Z. TRIED TO INDICATE BEST CHANCE FOR SHOWERS WITH RME/SYR EXPERIENCING SHOWERS BETWEEN 18Z AND 23Z AND KELM/KITH AND KBGM BETWEEN 15Z AND 19Z. HOWEVER, SHOWERS MAY DEVELOP AT ANYTIME AND POSSIBLY THUNDER AS WELL. AFTER 06Z TONIGHT AT KRME AND KSYR CONDITIONS SHOULD BECOME VFR THOUGH STILL A CHANCE FOR LOW CIGS. FURTHER TO THE SOUTH LOW MVFR AND IFR WILL EXIST TOWARD END OF TAF VALID TIME AS LOW LEVEL MOISTURE POOLS AHEAD OF APPROACHING COLD FRONT. LGT SRLY SFC WINDS EARLY...WILL INCREASE TO 8-12 KT. OUTLOOK... MON THRU TUE...AN UNSETTLED PERIOD...WITH SCATTERED TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF RESTRICTIVE CONDS FROM TIME TO TIME. TUE NGT THRU THUR...MAINLY VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM...KAH/PVN AVIATION...PVN
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
953 AM EDT SUN OCT 6 2013 .SYNOPSIS... HIGH PRESSURE EXTENDING OVER THE AREA FROM OFFSHORE WILL GRADUALLY MOVE EAST TODAY AND TONIGHT AS A COLD FRONT APPROACHES FROM THE WEST. THE FRONT WILL MOVE ACROSS THE AREA MONDAY NIGHT...THEN STALL OFFSHORE. COOL HIGH PRESSURE WILL BUILD OVER THE AREA TUESDAY...AND EXTEND OVER THE AREA FROM THE NORTH THROUGH THURSDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 950 AM SUNDAY...PATCHY DENSE FOG AND LOW STRATUS DISSIPATING AS DRIER AIR MIXES TO THE SURFACE. DESPITE WEAK HIGH PRESSURE AT THE SURFACE AND AN UPPER RIDGE AXIS ALONG THE COAST...LIGHT SHOWERS ARE FORMING IN A NARROW AXIS OF MOISTURE CONVERGENCE NEAR CAPE FEAR AND STREAMING NORTH INTO ONSLOW AND DUPLIN COUNTIES. LATEST 3 KM HRRR HAS A GOOD HANDLE ON THESE SHOWERS AND THEY MAY MOVE AS FAR NORTH AS THE GREENVILLE AREA BY EARLY AFTERNOON AND HAVE A 20 TO 30 PCT POP WEST OF HIGHWAY 17 INTO THE AFTERNOON. NO OTHER MAJOR CHANGES...AS PLENTIFUL SUNSHINE OUTSIDE OF THE SHOWERS SHOULD ALLOW TEMPERATURES TO AGAIN GET WELL INTO THE 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/... AS OF 300 AM SUN...MODELS CONTINUE TO INDICATE MOISTURE ADVECTION AHEAD OF APPROACHING FRONT...WITH SCT SHOWERS FROM OFF THE WATER AFFECTING MAINLY COASTAL SECTIONS. THUS NO CHANGE TO PREVIOUS 20/30 POPS. SRLY FLOW AND AT LEAST PT CLDY SKIES WILL KEEP TEMPS UP FOR LOWS MAINLY UPR 60S INLAND TO AROUND 70 COAST. && .LONG TERM /MONDAY THROUGH SATURDAY/... AS OF 345 AM SUN...BY MON MORNING A STRONG UPPER TROUGH WILL BE MOVING ACROSS THE EASTERN GREAT LAKES TOWARDS NEW ENGLAND WITH A COLD FRONT DRAPED ACROSS THE PIEDMONT OF THE CAROLINAS. THE FRONT WILL PUSH OFFSHORE MON NIGHT WITH WINDS SHIFTING N/NE BY TUES MORNING. MINOR TWEAKS TO POPS/WX/QPF WITH OVERALL DECENT MODEL AGREEMENT. HELD ONTO MID 80S FOR MAX TEMPS MON AS GOOD INSOLATION SHOULD EXIST EARLY ON ALLOWING TEMPS TO QUICKLY REBOUND FROM MORNING MINS. PRECIP/CLOUDS SHOULD KEEP TEMPS IN THE LOW/MID 60S MON NIGHT ALONG WITH BOUNDARY LAYER MIXING OVERNIGHT. LATEST GUIDANCE IN AGREEMENT WITH THE FRONT STALLING JUST OFF THE COAST TUES THEN SAGGING SOUTH SLIGHTLY TUES NIGHT INTO WED. STRONG RIDGE WILL SETUP OVER THE NORTHEASTERN U.S. TUES/TUES NIGHT AND RESIDE THERE THROUGH LATE WEEK. TRENDED POPS TO REFLECT LATEST MODEL BLEND WITH CHANCE POPS TUES MORN...DIMINISHING TO 10 PERCENT INLAND WITH LOW SLIGHT CHANCE ALONG THE CRYSTAL COAST/SOUTHERN OBX TUES NIGHT THROUGH WED. NE SURFACE FLOW WITH WEAK/BROAD UPPER LOW OVER THE REGION WED WILL LEAD TO COOLER TEMPS WITH HIGHS IN THE MID 70S. LATE WEEK FORECAST HIGHLY DEPENDENT ON BOUNDARY STALLED WELL OFF THE COAST. 00Z GUIDANCE INDICATES GREATER SPREAD IN GUIDANCE THURS WITH THE 00Z ECMWF DEVELOPING A SURFACE WAVE ALONG THE BOUNDARY OFF THE COAST WHICH RETROGRADES OVER EASTERN NC WED NIGHT INTO THURS...WHILE THE 00Z GFS DEVELOPS A WEAKER SURFACE REFLECTION AND KEEPS ITS ENERGY FARTHER OFF THE COAST. HEDGED TOWARDS A MODEL BLEND FOR LATE WEEK WITH HIGHER WEIGHT ON LATEST WPC GUIDANCE. NE SURFACE FLOW WILL PERSIST THROUGH THURS THEN SHIFT N FRI INTO SAT...WITH SPEEDS DEPENDENT ON LOW DEVELOPMENT. TEMPS WED-SAT WILL REMAIN 3-6 DEGREES BELOW CLIMO FOR EARLY OCTOBER. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... SHORT TERM /THROUGH 12Z MON/... AS OF 730 AM SUNDAY...CURRENT WDSPRD IFR/LIFR CONDITIONS WILL LIFT TO VFR BY 14Z. PRE-FRONTAL WARM SECTOR VFR CONDITIONS WILL PREVAIL REST OF TODAY INTO THESE EVENING...WITH ISOLATED SHOWER THREAT MAINLY SRN SECTIONS LATE MORNING AND AFTN. MOS GDNC IS INDICATING ANOTHER PERIOD OF IFR/LIFR CIGS/VSBYS LATE TONIGHT...BUT WINDS NOT EXPECTED TO DECOUPLE...AND LIGHT SRLY FLOW LIKELY TO RESULT IN STRATUS CIGS NEAR 1K FT. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 330 AM SUN...LOW-LEVEL MOISTURE INCREASES WITH SHOWERS BECOMING NUMEROUS MON INTO MON NIGHT. EXPECT PERIODS OF MVFR CEILINGS AND VSBYS FROM LATE SUN NIGHT THROUGH TUES. HIGH PRESSURE RETURNS WED AND THURS BUT WILL HAVE A WEAK BOUNDARY LINGERING OFF THE COAST SO CANNOT RULE OUT PRECIP POSSIBILITY MAINLY FOR EWN/OAJ. NE FLOW WILL PERSIST ACROSS THE TERMINALS THROUGH THE LONG TERM WITH GENERALLY VFR CONDITIONS EXPECTED. && .MARINE... SHORT TERM /THROUGH TONIGHT/... AS OF 955 AM SUNDAY...LIGHT SOUTHERLY WINDS AND SEAS OF 1 TO 2 FEET CONTINUE THIS MORNING. WINDS/SEAS BUILD TONIGHT AS GRADIENT TIGHTENS BETWEEN APPROACHING COLD FRONT AND HIGH PRESSURE WELL TO THE EAST. MINIMAL CHANGES TO THE SHORT TERM MARINE FORECAST. LONG TERM /MONDAY THROUGH THURSDAY/... AS OF 350 PM SUN...MODEST CHANGES TO THE LONG TERM MARINE FORECAST. ADJUSTED SCA TO REFLECT LATEST THINKING ON TIMING OF SE WINDS APPROACHING 20 KTS AND SEAS BUILDING TO 6 FT FROM OFF OREGON INLET SOUTH TO ONSLOW BAY...MID MORNING MON TO MON EVENING. A COLD FRONT WILL PUSH THROUGH THE WATERS MON NIGHT AND EXPECT SE WINDS TO INCREASE AHEAD OF THE FRONT DUE TO GRADIENT BETWEEN THE FRONT AND HIGH PRESSURE OFF THE COAST. EXPECT ANOTHER SURGE OF WINDS BEHIND THE FRONT TUES WITH N/NE WINDS GUSTING NEAR 20 KTS AND SEAS BUILDING TO 6+ FT WITH SMALL CRAFT ADVISORY CONDITIONS AGAIN LIKELY FROM TUES INTO THURS. LATEST LOCAL NWPS/SWAN MODEL AND 00Z WW3 GUIDANCE IN GOOD AGREEMENT THROUGH TUES. WW3 WITH SMALL ADJUSTMENTS WAS USED WED/THURS ALTHOUGH WINDS/SEAS MAY NEED TO BE INCREASED IF 00Z ECMWF SCENARIO OF LOW PRESSURE JUST OFF THE NC COAST COMES TO FRUITION. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 9 PM EDT MONDAY FOR AMZ152- 154-156-158. && $$ SYNOPSIS...JBM NEAR TERM...CTC SHORT TERM...JBM LONG TERM...DAG AVIATION...JBM/DAG MARINE...JBM/CTC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
900 AM EDT SUN OCT 6 2013 .SYNOPSIS... HIGH PRESSURE WILL SHIFT OFFSHORE TODAY...IN ADVANCE OF A COLD FRONT APPROACHING THE MOUNTAINS FROM THE WEST. THE COLD FRONT WILL TRACK SLOWLY EAST ACROSS THE CAROLINAS ON MONDAY BEFORE PROGRESSING OFFSHORE MONDAY NIGHT. IN THE WAKE OF THE FRONT...STRONG HIGH PRESSURE WILL EXTEND SOUTHWARD INTO THE REGION ON TUESDAY AND WEDNESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 900 AM SUNDAY... EXTENDED THE DENSE FOG ADVISORY THROUGH 10 AM. FOG SHOULD START TO LIFT BETWEEN 9 AM AND 10 AM. HRRR VISIBILITY FORECAST SHOWS A RAPID REDUCTION IN FOG BY 14Z. A FEW SPOTS MAY EXTENDED JUST PAST 14Z IN TERMS OF LOCALLY DENSE...BUT ANTICIPATE IMPROVEMENT DURING THE MID-MORNING. FOR THE REST OF THE DAY...THE LATEST SPC MESOANALYSIS SHOWS WEAK INSTABILITY ALONG THE COAST...WITH MLCAPE AROUND 250J/KG. GIVEN THE MOIST LOW-LEVEL AIR MASS...AND ENOUGH INSTABILITY BELOW WHAT IS A GOOD CAP AROUND 600MB ON KGSO AND KMHX SOUNDINGS...A FEW SHOWERS WERE MOVING NORTH-NORTHWEST TOWARD THE FAR SOUTHERN TIP OF SAMPSON COUNTY DURING THE MID-MORNING. AS THE GFS WAS THE LONE MODEL TO DO IT SATURDAY AFTERNOON...ALL OF THE GUIDANCE IS NOW ON BOARD WITH ISOLATED-TO-SCATTERED SHOWERS MAINLY SOUTH OF A LINE FROM ABOUT KMEB TO KRWI DEVELOPING DURING THE DAY...IN THE MOIST SOUTHERLY FLOW... WITH LIMITED INSTABILITY OF ROUGHLY 100 TO 300J/KG OF MLCAPE IN THE LOWEST KM...AND JUST ENOUGH LIFT IN THE STEEP LAPSE RATES BELOW THE CAP. ACTIVITY SHOULD BE LOW-TOPPED AND LIKELY WITHOUT THUNDER...BUT HAVE SPREAD ISOLATED-TO-SCATTERED SHOWERS IN THE FORECAST FARTHER NORTHWEST WITH THE MID-MORNING UPDATE. CONSEQUENTLY LOWERED MAXES A DEGREE OR TWO IN MANY AREAS...MOSTLY SHOWING HIGHS IN THE MID 80S. -DJF OVERNIGHT...DPVA ASSOCIATED WITH SMALL AMPLITUDE DISTURBANCES IN STRENGTHENING SW FLOW ALOFT AND STRENGTHENING LOW-LEVEL WARM ADVECTION /MARGINAL INSTABILITY/ SHOULD RESULT IN WIDESPREAD SHOWERS OVER THE MOUNTAINS/FOOTHILLS WHERE LIFT WILL BE FURTHER ENHANCED BY OROGRAPHIC EFFECTS...WITH PRECIP CHANCES INCREASING OVER THE WESTERN PIEDMONT AFTER MIDNIGHT. EAST OF THE HWY 1 CORRIDOR...CHANCES WILL BE MUCH LOWER...THOUGH AT LEAST ISOLD SHOWERS WILL REMAIN POSSIBLE GIVEN AN ONSHORE FLOW. LOWS TONIGHT WILL BE TEMPERED BY INCREASING CLOUD COVER AND A SOUTHERLY BREEZE...IN THE UPPER 60S TO LOWER 70S. -VINCENT && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... AS OF 330 AM SUNDAY... PRECIP CHANCES: ALTHOUGH THE BEST UPPER LEVEL FORCING WILL TRACK NORTHEAST OF CENTRAL NC ACROSS THE MID-ATLANTIC MON INTO MON NIGHT...HEIGHT FALLS AND DPVA ASSOCIATED WITH SMALL AMPLITUDE DISTURBANCES IN SW FLOW ALOFT ALONG THE LEADING EDGE OF THE APPROACHING UPPER LEVEL TROUGH AND LOW-LEVEL CONVERGENCE ASSOCIATED WITH THE ATTENDANT LOW-LEVEL TROUGH AND SURFACE FRONT SHOULD PROVIDE MORE THAN ADEQUATE FORCING FOR WIDESPREAD CONVECTION ON MONDAY...ESP WITH EXCELLENT LOW-LEVEL MOISTURE AND FAVORABLE DIURNAL TIMING CONTRIBUTING TO MODERATE INSTABILITY (1000-1500 J/KG MLCAPE). WILL INDICATE PRECIP CHANCES BETWEEN 80-100%...WITH THE BEST COVERAGE BETWEEN 15Z MONDAY MORNING AND 00-03Z MONDAY EVENING. TEMPERATURES: HIGH TEMPS ON MONDAY WILL LARGELY BE DICTATED BY CLOUD COVER AND CONVECTION. GIVEN THAT PRECIP CHANCES WILL INCREASE EARLY IN THE MORNING FROM THE WEST...EXPECT THE COOLEST HIGHS (MID 70S) IN THE WESTERN PIEDMONT AND WARMEST (LOW/MID 80S) IN THE COASTAL PLAIN. UNCERTAINTY PERSISTS W/REGARD TO THE TIMING OF FROPA MON EVE/NIGHT. GIVEN THAT TEMPS WILL ENTIRELY DEPEND ON COLD ADVECTION...LOWS ARE VERY MUCH IN QUESTION TUE MORNING. THE LATEST 00Z GUIDANCE INDICATES FROPA SHOULD OCCUR BY MIDNIGHT (EARLIEST W/NW AND LATEST SE)...WITH PRONOUNCED PRESSURE RISES RESULTING IN GUSTY NORTHERLY WINDS (10-15 KT SUSTAINED WITH GUSTS UP TO 20-25 KT) /STRONG COLD ADVECTION/ MON NIGHT. GIVEN THAT THE LATEST FCST SOUNDINGS INDICATE LOWS FALLING TO NEAR 50F IN THE FAR NW PIEDMONT AND INTO THE 50S EVERYWHERE ELSE (UPPER 50S TO NEAR 60F IN THE SE COASTAL PLAIN)...FEEL CONFIDENT ENOUGH TO DECREASE LOWS A GOOD 5-8F FROM PREVIOUS FORECASTS. SEVERE THREAT: RELATIVELY STRONG/VEERING LOW-LEVEL FLOW WILL BE PRESENT LATE TONIGHT THROUGH EARLY MONDAY AFTERNOON. FCST SOUNDINGS SHOW CYCLONICALLY CURVED HODOGRAPHS WITH 150-200 M2/S2 OF 0-1 KM SRH TONIGHT THROUGH ~18Z MON...ESPECIALLY FROM THE TRIANGLE INTO THE NORTHERN AND WESTERN PIEDMONT (IN RELATIVE CLOSER VICINITY TO THE UPPER LEVEL LOW) WHERE DEEP-LAYER SHEAR WILL BE ON THE ORDER OF 35-45 KT...SLIGHTLY STEEPER MID-LEVEL LAPSE RATES WILL BEGIN ADVECTING INTO THE REGION FROM THE SW...AND LCL`S WILL BE VERY LOW AT 500-1000M. THIS IS ALL PROGGED TO OCCUR IN THE PRESENCE OF GOOD LOW-LEVEL FORCING ASSOC/W THE LOW-LEVEL TROUGH PROGRESSING INTO THE AREA FROM THE WEST AND POSSIBLY DPVA ASSOC/W SMALL AMPLITUDE WAVES IN SW FLOW ALOFT JUST DOWNSTREAM OF THE UPPER LOW TRACKING INTO THE OH VALLEY. WITH THE ABOVE IN MIND...EXPECT A THREAT FOR ISOLD SUPERCELLS CAPABLE OF PRODUCING DAMAGING WINDS AND PERHAPS A TORNADO. THE TORNADO POTENTIAL WOULD APPEAR TO BE GREATEST ALONG AND WEST OF HWY 1 AND PRIOR TO ~18Z (GIVE OR TAKE A FEW HOURS)...BEFORE LOW-LEVEL FLOW BECOMES INCREASINGLY UNIDIRECTIONAL AND HODOGRAPHS STRAIGHTEN. BASED ON THE LATEST DATA...WOULD BE SURPRISED IF AT LEAST PORTIONS OF CENTRAL NC ARE NOT INCLUDED IN A SLIGHT RISK ON FUTURE CONVECTIVE OUTLOOKS FOR MONDAY. -VINCENT && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 229 AM SUNDAY... A MUCH COOLER AIR MASS WILL FILTER INTO OUR REGION COURTESY OF THE STRONG (1030 MB) SURFACE HIGH PRESSURE PRESSURE THAT IS FORECAST TO BE CENTERED OVER NEW ENGLAND TUESDAY INTO WEDNESDAY. THE MAIN FORECAST QUESTION WILL BE THE EXTENT OF THE POST-FRONTAL CLOUDINESS AND POSSIBLY SOME LIGHT RAIN IN THE EAST AND SOUTH TUESDAY. THE POTENTIAL FOR LINGERING CLOUDINESS/LIGHT RAIN MAY ALSO BE ENHANCED BY THE POTENTIAL FOR SOME UPPER SUPPORT TO LINGER ALONG THE SE US COAST INTO TUESDAY AS WELL. NOT ALL MODEL SOLUTIONS ARE ON BOARD WITH THE LINGERING UPPER SUPPORT. HOWEVER... THERE APPEARS TO BE GOOD OVERALL AGREEMENT IN AT LEAST LOW LEVEL MOISTURE LINGERING INTO TUESDAY DUE TO THE MOIST ONSHORE NE FLOW ALONG THE COAST EXTENDING INLAND INTO THE FAR EASTERN COASTAL PLAIN. MODELS SUGGEST MUCH DRIER AIR INLAND WHERE THE PIEDMONT SHOULD SEE AMPLE CLEARING TUESDAY AS THE DRIER MID LEVEL AIR DIVES INTO THE PIEDMONT. FOR TUESDAY THROUGH WEDNESDAY... A CHANCE OF LINGERING LIGHT SHOWERS IN THE SE ZONES EARLY TUESDAY... THEN VARIABLY CLOUDY BREEZY AND COOLER. PARTLY SUNNY ELSEWHERE... BREEZY AND COOLER TUESDAY. THEN MOSTLY CLEAR TO PARTLY CLOUDY TUESDAY NIGHT AND WEDNESDAY NIGHT. TEMPS SHOULD BE NEAR NORMAL (HIGHS 70-75)... LOWS 50-55. THE FORECAST FOR THURSDAY THROUGH SATURDAY HAS BECOME MUDDLED IN THE PAST FEW DAYS. THERE ARE A WIDE RANGE OF POSSIBILITIES WITHIN THE MODELS RANGING FROM THE POTENTIAL FOR SIGNIFICANT WAVE DEVELOPMENT ALONG THE OLD SURFACE BOUNDARY ALONG THE SE COAST... TO EVEN THE POTENTIAL FOR A RETROGRADING MID/UPPER LOW FROM THE WESTERN ATLANTIC BACK TOWARD... OR EVEN INLAND... ALONG THE EASTERN SEABOARD LATE IN THE WEEK INTO THE WEEKEND. THE TRENDS ARE FOR THE VERY LEAST A MORE UNSETTLED PATTERN... WITH INCREASING POTENTIAL FOR WETNESS LATE IN THE WEEK. FOR NOW... WE WILL SHOW A GRADUAL INCREASE IN CLOUDS WED-THU... WITH A CHANCE OF RAIN BY FRI-SAT. THE HIGH PRESSURE TO THE NORTH WILL CONTINUE THE COOL TEMPERATURE RESUME THROUGH THE WEEK AS THE FLOW CONTINUES FROM THE NE. LOWS UPPER 40S TO MID 50S INCREASING TO MID TO UPPER 50S BY SAT. HIGHS IN THE LOWER TO MID 70S. && .AVIATION /13Z SUNDAY THROUGH THURSDAY/... AS OF 900 AM SUNDAY... 24-HR TAF PERIOD: FOG AND LOW CEILINGS PRIMARILY AFFECTING THE FAY/RWI TERMINALS (THOUGH VERY NEAR THE RDU TERMINAL) WILL LIFT AND SCATTER OUT TO VFR BY 15Z THIS MORNING. AFTER 15Z...VFR CONDITIONS WILL PREVAIL WITH CEILINGS BETWEEN 3500-4500 FT AGL. ISOLD LOW- TOPPED SHOWERS WILL BE POSSIBLE AT ALL TERMINALS BUT MAINLY TOWARD KFAY AND KRWI THIS AFTERNOON INTO THE EARLY EVENING...THOUGH CHANCES ARE TOO LOW TO INCLUDE MENTION AT THIS TIME. BY THE END OF THE TAF PERIOD... WIDESPREAD IFR/LIFR CEILINGS ARE EXPECTED TO RAPIDLY DEVELOP BY OR SHORTLY AFTER MIDNIGHT (04Z) WITH WIDESPREAD SHOWER ACTIVITY PROGRESSING EAST INTO THE WESTERN PIEDMONT (INT/GSO TERMINALS) BY SUNRISE MON. LOOKING AHEAD: EXPECT WIDESPREAD SHOWERS/THUNDERSTORMS DURING THE DAY MONDAY AS A COLD FRONT TRACKS EASTWARD INTO THE CAROLINAS. UNCERTAINTY IN THE FCST INCREASES THEREAFTER. PRECIP CHANCES SHOULD DECREASE FROM WEST-EAST MON EVENING AS THE FRONT PROGRESSES EAST TO THE CAROLINA COAST BEFORE STALLING NEAR OR JUST OFFSHORE. SUB-VFR CEILINGS MAY PERSIST MON NIGHT INTO TUE...ESP IN EASTERN TERMINALS IN CLOSER VICINITY TO THE STALLED FRONT. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NCZ010-011- 026>028-040>043-073>078-083>086-088-089. && $$ SYNOPSIS...VINCENT NEAR TERM...DJF/VINCENT SHORT TERM...VINCENT LONG TERM...BADGETT AVIATION...DJF/VINCENT
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
950 AM CDT SUN OCT 6 2013 .UPDATE... ISSUED AT 950 AM CDT SUN OCT 6 2013 MORNING UPDATE PRIMARILY FOCUSES ON SKY AND TEMPS AS WESTERN TWO THIRDS OF CWA IS NOW CLEAR WITH A BAND OF LOW CLOUDS STILL OVER EASTERN AND SOUTHEASTERN ZONES. ONLY SEEING A FEW REPORTS OF RAIN...LATEST AT DETROIT LAKES. 12Z NAM AND LATEST RAP OVERDOING PRECIP FOR THE AM...STILL PRODUCING ANOTHER TENTH OF AN INCH. EXPECT ANY MEASURABLE PRECIP TO BE MORE IN THE RANGE OF A COUPLE OF HUNDREDTHS OF AN INCH. WILL LOWER POPS SOME AND KEEP MENTION OF DRIZZLE...BUT THINK ANY PRECIP SHOULD END BY NOON TODAY. UPDATE ISSUED AT 703 AM CDT SUN OCT 6 2013 RADAR STILL INDICATING A NARROW BAND OF LIGHT RAIN/SPRINKLES FROM FERTILE MN TO FAR TO GWINNER ND. BAND WAS SHIFTING SOUTH AT 5 KNOTS. EXPECT RAIN TO CONTINUE TO DIMINISH AND SHIFT SOUTH. WILL LET FREEZE WARNING/FROST ADVISORY EXPIRE AT 9 AM CDT. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 401 AM CDT SUN OCT 6 2013 THE NAM WAS THE FAST MODEL WITH THE ECMWF AND GEM SLOWER AND THE GFS THE SLOWEST MODEL RUN. WILL PREFER THE GFS AND ECMWF. UPPER AIR PATTERN REMAINS PROGRESSIVE. WATER VAPOR LOOP INDICATED UPPER LEVEL RIDGE AXIS OVER THE PACIFIC NORTHWEST. RIDGE FORECAST TO MOVE ACROSS THE NORTHERN PLAINS BY TUE MORNING. RADAR INDICATED PRECIPITATION WAS DECREASING IN AREA AND INTENSITY AND WAS IN A NARROW BAND FROM NEAR BDE TO FORMAN ND. INDIVIDUAL CELLS WERE MOVING TO THE SOUTHWEST ABOUT 45 KNOTS WHILE THE BAND WAS MOVING WEST ABOUT 4 KNOTS. MODELS REDUCE QPF TO AROUND A HUNDRED OF AN INCH...ESSENTIALLY ZERO...AFTER 12Z SUN. ALSO MODELS SIGNIFICANTLY DECREASE THE MID LEVEL RH FIELD (700-500 HPA) AFTER 12Z. WILL REDUCE POPS FOR TODAY. WILL ADD DRIZZLE FOR SOUTHEAST ZONES TODAY. LITTLE ADDITIONAL PRECIPITATION EXPECTED FOR TODAY. LITTLE CHANGE TO HIGH TEMPS TODAY AND LOW TEMP TUE MORNING. WENT A COUPLE DEGREES HIGHER FOR TONIGHT AND TUE AFTERNOON. WENT COOLER NORTHEAST ZONES FOR MON HIGH AND A COUPLE DEGREES LOWER FOR WESTERN ZONES WED MORN. OTHERWISE RISING TEMPS EXPECTED FOR THE NEXT COUPLE DAYS. WILL KEEP FREEZE WARNING/FROST ADVISORY FOR NORTHWEST ZONES THIS MORNING. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 401 AM CDT SUN OCT 6 2013 A QUIET SOUTHWEST FLOW PATTERN IS EXPECTED FOR MID-WEEK. A WEAK SFC BOUNDARY MAY BE DRAPED SOMEWHERE ACROSS THE AREA ON WEDNESDAY IN ASSOCIATION WITH AN UPPER LEVEL DISTURBANCE PASSING WELL TO THE NORTH ACROSS CANADA...BUT NOT EXPECTING ANY PRECIP WITH DRY AIR STILL IN PLACE. INCREASINGLY MOIST SOUTHERLY LOW-LEVEL FLOW WILL DEVELOP LATE WEEK AS ANOTHER STRONG UPPER LOW LIFTS OUT OF THE ROCKIES. THE 00Z GFS/ECMWF ARE IN GOOD AGREEMENT LIFTING THE UPPER LOW INTO THE NORTHERN PLAINS BY LATE FRIDAY...WITH THE ECMWF JUST A TAD SLOWER OVERALL. SHOWERS/STORMS MAY DEVELOP BY FRIDAY...WITH SOME SHOWERS POSSIBLY LINGERING INTO SATURDAY. THE 00Z ECMWF/GFS INDICATE A MORE PROGRESSIVE SOLUTION COMPARED WITH THE 12Z ECMWF...BUT WITH THE STRENGTH OF DOWNSTREAM RIDGING...SOME UNCERTAINTY EXISTS WITH THE TIMING AND PLACEMENT OF THE SYSTEM. TEMPS WILL REMAIN ABOVE NORMAL THROUGH FRIDAY...WITH HIGHS IN THE 60S AND 70S AND LOWS IN THE 40S AND 50S. TEMPS WILL TREND COOLER NEXT WEEKEND BEHIND THE SYSTEM. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 703 AM CDT SUN OCT 6 2013 IFR CONDITIONS WERE LOCATED ROUGHLY SOUTHEAST OF A LINE FROM BDE TO FAR TO GWINNER ND. FOG AND DRIZZLE WAS OCCURRING ACROSS MUCH OF NORTHWEST AND WEST CENTRAL MN. FOG LOOP INDICATED CLEARING LINE WEST OF A LINE FROM ROX TO ELLENDALE ND AND WAS MOVING TO THE SOUTHEAST AT 15 KNOTS. CLEARING LINE SHOULD EXIT THE FORECAST AREA BY MID AFTERNOON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...SPEICHER SHORT TERM...HOPPES LONG TERM...MAKOWSKI AVIATION...HOPPES
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
953 AM CDT SUN OCT 6 2013 .DISCUSSION... THE RAIN AREA CONTINUED TO WEAKEN AND MOVE TO THE COAST AT MID MORNING. ADJUSTED POPS AND WEATHER TO REFLECT THE CURRENT TRENDS. 40 && .PREV DISCUSSION... /ISSUED 647 AM CDT SUN OCT 6 2013/ DISCUSSION... SEE AVIATION FOR 12Z TAF ISSUANCE. AVIATION... RAIN SHOWERS ARE MOVING IN FROM THE WEST THIS MORNING WITH KCLL HAVING ALREADY EXPERIENCED RAIN. SHOWERS ON THE NORTHERN EDGE OF THE LINE APPEAR TO BE FALLING APART WHILE THE SOUTHERN EXTENT OF CELLS IS STILL HOLDING TOGETHER. THESE SHOWERS ARE IN ASSOCIATION WITH THE 850MB FRONT. RAP HAS BY FAR DONE THE BEST WITH THIS SHOWING GOOD LIFT IN ASSOCIATION WITH THE FRONT. THE RAP DOES WEAKEN THE STRENGTH OF LIFT THOUGH AS IT MOVES EASTWARD. IN GENERAL WOULD AGREE WITH THIS SOLUTION GIVEN THAT SHOWERS ARE ALREADY SHOWING SIGNS OF WEAKENING. FORECAST SOUNDINGS ALSO SHOW INSTABILITY BEING LIMITED. IN ASSOCIATION WITH THE SHOWERS IS AN OVC DECK AROUND 5000 FT. LOOKS LIKE SITES SHOULD STAY VFR WITH SHOWERS COMING TO AN END AT KGLS BY NOON. CLEARING CONDITIONS WILL THEN START TO COMMENCE AFTER THE RAIN WITH GUSTY NORTHERLY WINDS. 23 PREV DISCUSSION... /ISSUED 615 AM CDT SUN OCT 6 2013/ UPDATE... STORMS TO THE WEST HAVE CONTINUE TO MARCH EAST AS ENTRANCE REGION ADVANCES EAST INTO THE AREA. HAVE UPDATED THE FORECAST AND RAISED POPS TO LIKELY IN THE WEST AND CHANCE IN THE CENTRAL. STILL EXPECT THAT THESE WILL WEAKEN IN THE NEXT FEW HOURS. BY NOON ONLY STORMS SHOULD BE NEAR THE COAST IN THE SW AREAS AND IN THE COASTAL WATERS. 45 PREV DISCUSSION... /ISSUED 444 AM CDT SUN OCT 6 2013/ DISCUSSION... COLD FRONT HAS MOVED WELL OFFSHORE BUT ENTRANCE REGION OF SPEED MAX LIFTING OUT THROUGH NORTH TEXAS AND THE NORTHERN HILL COUNTRY AIDING DEVELOPMENT OF RA/SHRA/TSRA NEAR THE 825-850MB FRONTAL BOUNDARY THIS MORNING. STORMS SHOULD SPREAD EAST BUT INSTABILITY SHOULD WANE THIS MORNING SO EXPECT THE WESTERN COUNTIES WILL HAVE A DECENT CHANCE AT RAINFALL BEFORE 7 AM WITH LOWER CHANCES FOR THE CENTRAL COUNTIES THEN TAPERING OFF AND SHIFTING SOUTH AND SOUTHWEST THIS MORNING. CLOUD COVER WILL LIKELY CONTINUE THROUGH NOON THEN CLEAR FROM THE NORTHWEST. TEMPERATURES WILL BE A GOOD DEAL COOLER WITH HIGHS ONLY REACHING 78-80 DEGREES TODAY WITH NORTHERLY WINDS. THIS AFTERNOON MUCH DRIER CONDITIONS WILL PREVAIL THOUGH STRONGER WINDS SHOULD COME THROUGH THIS MORNING AND MAINLY IN THE WESTERN CWA. IF NOT FOR THE MOIST FUELS AND RAINFALL THIS MORNING WOULD BE NEAR RED FLAG WARNING FOR THE WESTERN COUNTIES...BY MID AFTERNOON HUMIDITY 17-22 PERCENT SHOULD BE COMMON THERE. RIDGE BUILDS IN AND THE REGION WILL SEE A FEW COOL EARLY OCTOBER NIGHTS AND PLEASANT AFTERNOONS. GREAT WEATHER FOR PATIO PARTIES AND PICNICS AND FOOTBALL. UPPER TROUGH OVER THE CENTRAL PLAINS MOVES INTO THE GREAT LAKES BY MONDAY AFTERNOON AND UPPER RIDGING BUILDS OVER TEXAS KEEP SE TX DRY THEN THE NEXT TROUGH IN THE DEVELOPING PROGRESSIVE PATTERN SINKS DOWN OVER THE WESTERN U.S. AND TX RIDGE SHIFTS EAST BY THURSDAY THIS WILL OPEN THE GULF BACK UP WITH A MODIFYING AIRMASS OVER THE GULF RETURNING. TEMPS SHOULD FOLLOW A WARMING TREND WITH RAIN CHANCES COMING BACK IN ON SATURDAY AS TROUGH LIFTS OUT. FAVORING THE ECMWF IN THE EXTENDED AND MAY HAVE A STRONGER SUBTROPICAL JET TO DEAL WITH NEXT WEEKEND WITH A FRONT SETTLING INTO TEXAS AND POTENTIALLY STALLING. RECORD HIGH OF 93 TIED AT HOBBY YESTERDAY. 45 MARINE... THE SURFACE COLD FRONT HAS PUSHED THROUGH THE WATERS THIS MORNING LEAVING STRONG OFFSHORE WINDS IN ITS WAKE. ADVISORY CRITERIA HAS ALREADY BEEN REACHED SO WILL CONTINUE THE SMALL CRAFT ADVISORY UNTIL NOON TODAY. THIS AFTERNOON WINDS WILL START TO DECREASE SLOWLY. BY SUNDAY EVENING WINDS SHOULD BE BELOW ADVISORY CRITERIA WHILE STILL ABOVE SCEC CRITERIA. WINDS WILL CONTINUE TO FALL BELOW SCEC CRITERIA MONDAY AFTERNOON. SURFACE HIGH PRESSURE WHICH WILL ALLOW FOR OFFSHORE WINDS TODAY WILL DRIFT EASTWARDS THE NEXT COUPLE OF DAYS ALLOWING FOR ONSHORE WINDS TO RETURN WEDNESDAY. LIGHT TO OCCASIONALLY MODERATE ONSHORE WINDS WILL CONTINUE THROUGH THE REMAINDER OF THE WORK WEEK. 23 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 79 52 84 55 87 / 10 0 0 0 0 HOUSTON (IAH) 79 52 84 55 86 / 70 0 0 0 0 GALVESTON (GLS) 78 63 82 67 82 / 40 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 5 PM CDT THIS AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM... WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM. && $$ DISCUSSION...40 AVIATION/MARINE...47
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
647 AM CDT SUN OCT 6 2013 .DISCUSSION... SEE AVIATION FOR 12Z TAF ISSUANCE. && .AVIATION... RAIN SHOWERS ARE MOVING IN FROM THE WEST THIS MORNING WITH KCLL HAVING ALREADY EXPERIENCED RAIN. SHOWERS ON THE NORTHERN EDGE OF THE LINE APPEAR TO BE FALLING APART WHILE THE SOUTHERN EXTENT OF CELLS IS STILL HOLDING TOGETHER. THESE SHOWERS ARE IN ASSOCIATION WITH THE 850MB FRONT. RAP HAS BY FAR DONE THE BEST WITH THIS SHOWING GOOD LIFT IN ASSOCIATION WITH THE FRONT. THE RAP DOES WEAKEN THE STRENGTH OF LIFT THOUGH AS IT MOVES EASTWARD. IN GENERAL WOULD AGREE WITH THIS SOLUTION GIVEN THAT SHOWERS ARE ALREADY SHOWING SIGNS OF WEAKENING. FORECAST SOUNDINGS ALSO SHOW INSTABILITY BEING LIMITED. IN ASSOCIATION WITH THE SHOWERS IS AN OVC DECK AROUND 5000 FT. LOOKS LIKE SITES SHOULD STAY VFR WITH SHOWERS COMING TO AN END AT KGLS BY NOON. CLEARING CONDITIONS WILL THEN START TO COMMENCE AFTER THE RAIN WITH GUSTY NORTHERLY WINDS. 23 && .PREV DISCUSSION... /ISSUED 615 AM CDT SUN OCT 6 2013/ UPDATE... STORMS TO THE WEST HAVE CONTINUE TO MARCH EAST AS ENTRANCE REGION ADVANCES EAST INTO THE AREA. HAVE UPDATED THE FORECAST AND RAISED POPS TO LIKELY IN THE WEST AND CHANCE IN THE CENTRAL. STILL EXPECT THAT THESE WILL WEAKEN IN THE NEXT FEW HOURS. BY NOON ONLY STORMS SHOULD BE NEAR THE COAST IN THE SW AREAS AND IN THE COASTAL WATERS. 45 PREV DISCUSSION... /ISSUED 444 AM CDT SUN OCT 6 2013/ DISCUSSION... COLD FRONT HAS MOVED WELL OFFSHORE BUT ENTRANCE REGION OF SPEED MAX LIFTING OUT THROUGH NORTH TEXAS AND THE NORTHERN HILL COUNTRY AIDING DEVELOPMENT OF RA/SHRA/TSRA NEAR THE 825-850MB FRONTAL BOUNDARY THIS MORNING. STORMS SHOULD SPREAD EAST BUT INSTABILITY SHOULD WANE THIS MORNING SO EXPECT THE WESTERN COUNTIES WILL HAVE A DECENT CHANCE AT RAINFALL BEFORE 7 AM WITH LOWER CHANCES FOR THE CENTRAL COUNTIES THEN TAPERING OFF AND SHIFTING SOUTH AND SOUTHWEST THIS MORNING. CLOUD COVER WILL LIKELY CONTINUE THROUGH NOON THEN CLEAR FROM THE NORTHWEST. TEMPERATURES WILL BE A GOOD DEAL COOLER WITH HIGHS ONLY REACHING 78-80 DEGREES TODAY WITH NORTHERLY WINDS. THIS AFTERNOON MUCH DRIER CONDITIONS WILL PREVAIL THOUGH STRONGER WINDS SHOULD COME THROUGH THIS MORNING AND MAINLY IN THE WESTERN CWA. IF NOT FOR THE MOIST FUELS AND RAINFALL THIS MORNING WOULD BE NEAR RED FLAG WARNING FOR THE WESTERN COUNTIES...BY MID AFTERNOON HUMIDITY 17-22 PERCENT SHOULD BE COMMON THERE. RIDGE BUILDS IN AND THE REGION WILL SEE A FEW COOL EARLY OCTOBER NIGHTS AND PLEASANT AFTERNOONS. GREAT WEATHER FOR PATIO PARTIES AND PICNICS AND FOOTBALL. UPPER TROUGH OVER THE CENTRAL PLAINS MOVES INTO THE GREAT LAKES BY MONDAY AFTERNOON AND UPPER RIDGING BUILDS OVER TEXAS KEEP SETX DRY THEN THE NEXT TROUGH IN THE DEVELOPING PROGRESSIVE PATTERN SINKS DOWN OVER THE WESTERN U.S. AND TX RIDGE SHIFTS EAST BY THURSDAY THIS WILL OPEN THE GULF BACK UP WITH A MODIFYING AIRMASS OVER THE GULF RETURNING. TEMPS SHOULD FOLLOW A WARMING TREND WITH RAIN CHANCES COMING BACK IN ON SATURDAY AS TROUGH LIFTS OUT. FAVORING THE ECMWF IN THE EXTENDED AND MAY HAVE A STRONGER SUBTROPICAL JET TO DEAL WITH NEXT WEEKEND WITH A FRONT SETTLING INTO TEXAS AND POTENTIALLY STALLING. RECORD HIGH OF 93 TIED AT HOBBY YESTERDAY. 45 MARINE... THE SURFACE COLD FRONT HAS PUSHED THROUGH THE WATERS THIS MORNING LEAVING STRONG OFFSHORE WINDS IN ITS WAKE. ADVISORY CRITERIA HAS ALREADY BEEN REACHED SO WILL CONTINUE THE SMALL CRAFT ADVISORY UNTIL NOON TODAY. THIS AFTERNOON WINDS WILL START TO DECREASE SLOWLY. BY SUNDAY EVENING WINDS SHOULD BE BELOW ADVISORY CRITERIA WHILE STILL ABOVE SCEC CRITERIA. WINDS WILL CONTINUE TO FALL BELOW SCEC CRITERIA MONDAY AFTERNOON. SURFACE HIGH PRESSURE WHICH WILL ALLOW FOR OFFSHORE WINDS TODAY WILL DRIFT EASTWARDS THE NEXT COUPLE OF DAYS ALLOWING FOR ONSHORE WINDS TO RETURN WEDNESDAY. LIGHT TO OCCASIONALLY MODERATE ONSHORE WINDS WILL CONTINUE THROUGH THE REMAINDER OF THE WORK WEEK. 23 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 79 52 84 55 87 / 60 0 0 0 0 HOUSTON (IAH) 79 52 84 55 86 / 40 0 0 0 0 GALVESTON (GLS) 79 63 82 67 82 / 30 0 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL NOON CDT TODAY FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM. && $$ AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
635 AM CDT SUN OCT 6 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT SUN OCT 6 2013 FORECAST A BIT MORE QUIET THAN PREVIOUS DAYS WITH LOW IMPACT WEATHER THROUGH THE PERIOD. A BIT OF A CHALLENGE WITH THE LONGWAVE LOW SHIFTING ACROSS THE REGION AND THE WRAP AROUND MOISTURE COMING IN LATE TODAY AND OVERNIGHT. WATER VAPOR IMAGERY LOCATES THE CENTER OF THE 300-500MB CIRCULATION EAST OF KSUX IOWA WITH A SLOW DRIFT EAST. REGIONAL RADARS ARE INDICATING WRAP AROUND MOIST PLUME CONTINUING FROM KINL-KFAR-KABR- CENTRAL NEBRASKA WITH RAINFALL OF .03 TO .08 PER HOUR IN THE BAND. CLOUDS ARE LOW TOO...SO A WELL SATURATED ENVIRONMENT. PER RAP ANALYSIS...GOOD CORRELATION WITH THE 305-308 THETA-E SURFACE AND FLOW UP THE SURFACE WITHIN THE MOIST PLUME / TROWAL. ANOTHER DEFORMATION BAND CLOSER TO THE LOW CENTER ITSELF IS FOUND IN NW IA WITH A FEW HUNDREDTHS PER HOUR THERE. THESE ARE PLAYERS FOR THE OVERNIGHT FORECAST. AT 3 AM...DRY SLOT AND CLEAR SKIES RUNNING THROUGH MOST OF THE FORECAST AREA...BUT LOWER CLOUD NOW MOVING SLOWLY EAST TOWARD MISS RIVER IN NERN IA AND SERN MN. SOME PATCHY FOG MAY BE AROUND WITH LIGHT WIND IN THE CLEAR SECTOR THIS MORNING AS DEWPOINT DEPRESSIONS ARE NEAR ZERO. THE LOW WILL SHIFT EAST TODAY AND THE CONSENSUS MODEL SOLUTIONS TRACK IT THROUGH THE QUAD CITIES OR A BIT NORTH. THIS PLACES THE NORTHERN SIDE OF THE LOW OVER THE SOUTHERN FORECAST AREA. LOW- LEVEL LAPSE RATES ARE PRETTY STEEP BY LATER AFTERNOON /7.5-8.5 C PER KM/ AS THIS OCCURS AND WITH CIRCULATION CENTER SO CLOSE...THINKING SCT SHOWERS WILL DEVELOP ACROSS THE SOUTH THIS AFTERNOON. THIS ALSO COMBINES WITH LIFT UP THE THETA-E SURFACES IN THAT AREA AND A SPOKE OF SHORTWAVE TROUGH ENERGY WORKING NORTH AROUND THE LOW. THIS SCT SHOWERS AREA WILL EXTEND BACK TOWARD THE WEST WHERE MAIN MOIST PLUME WILL BE INCOMING. TONIGHT...GOOD CONSENSUS ON DRAGGING THE WRAP AROUND RAIN BAND THROUGH THE AREA. SOUNDINGS ACROSS THE MODELS ARE SATURATED...SOME VERY SATURATED FROM 0-3KM. FORCING REMAINS THAT TROWAL AIR STREAM WITH THETA-E SURFACE LIFT RISING AS THE PARCEL MOVE SOUTH. ALTHOUGH WEAKER FORCING THAN CURRENTLY OUT WEST...THE 06.00Z GFS HAS 7 UB/S OF LIFT FROM 0-3KM AT KLSE AT 06Z AND THE LAYER IS TOTALLY SATURATED. THUS...HAVE PUT IN SCATTERED SHOWERS OVERNIGHT TO ACCOUNT FOR THIS...BUT THINKING THAT OUR RAIN CHANCES MAY BE TOO LOW. DAY SHIFT MAY NEED TO BUMP THE RAIN CHANCES. THE LOW MOVES EAST MONDAY AND WITH IT THE RAIN CHANCES AND THE CLOUDS. VERY LITTLE CHANGE TO THE TEMPERATURES FOR THE FORECAST CYCLE - VERY NEAR TO PREVIOUS FORECAST. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 AM CDT SUN OCT 6 2013 PRETTY QUIET PERIOD OVERALL WITH LONGWAVE RIDGE BUILDING OVER THE MIDWEST AS THE LONGWAVE TROUGH DIGS INTO THE SOUTHWEST U.S. THE GFS ENSEMBLES ARE IN GOOD AGREEMENT ON THE 500MB PATTERN THROUGH ABOUT THURSDAY WHICH DEFINES THE DIGGING OF THE LONGWAVE TROUGH OUT WEST. THE ENSEMBLES AND THE DETERMINISTIC ECMWF 05.12Z/06.00Z AND 06.00Z GEM/GFS SOLUTIONS DIVERGE ON HOW THAT TROUGH ENERGY LIFTS NORTHEAST TOWARD THE GREAT LAKES AND DAKOTAS FOR NEXT WEEKEND. OVERALL IT WILL BE A VERY MILD WEEK WITH ABOVE NORMAL TEMPERATURES AND SOUTHERLY FLOW UNDER THE RIDGE. BY LATE NEXT WEEK...THUNDERSTORMS CHANCES MOVE INTO THE FORECAST AS THE TROUGH EJECTS NORTHEAST. OVERALL...THERE ARE TIMING DIFFERENCES AND PREFER THE SLIGHTLY MORE STABLE ECMWF FAMILY OF SOLUTIONS FOR SLOWER TIMING. BOTTOM LINE IS THUNDERSTORM CHANCES LATE WEEK AFTER A WARM SUNNY WEEK. NOT SURE THERE IS EVEN A FROST OR VALLEY FOG DAY IN THERE WITH THE CLEAR SKIES PREDICTED BECAUSE THE SOUTHERLY FLOW KICKS IN SO RAPIDLY. ONLY FROST TIME FRAME IS POSSIBLY TUESDAY MORNING IN CENTRAL WISCONSIN IF THE SOUTHERLY FLOW DOESNT KICK IN FAST ENOUGH. A CALM MONDAY EVENING AND RAPID COOL DOWN WOULD SEEM TO SUGGEST LOWS IN THE UPPER 30S....WITH LIGHT SOUTH WINDS KICKING IN AFTER MIDNIGHT. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING) ISSUED AT 635 AM CDT SUN OCT 6 2013 A STRONG MID LEVEL LOW ROTATING SLOWLY EAST ACROSS IA WILL SPREAD VFR CLOUD DECKS IN THE 4K-5K FT RANGE ACROSS THE TAF SITES TODAY. DEEPER WRAP AROUND MOISTURE ALONG WITH MVFR/IFR CLOUD DECKS AND SOME MVFR VSBYS IN -RA/-SHRA NORTH/WEST OF THIS LOW WAS LOCATED OVER WESTERN MN/EASTERN SD EARLY THIS MORNING. AS THE MID LEVEL LOW MOVES INTO NORTHWEST IL BY LATE THIS AFTERNOON/EVENING...THE LOWER CLOUDS/-RA/-SHRA WILL SPREAD EAST/SOUTHEAST ACROSS THE TAF SITES TONIGHT. WITH ANY PRECIP EXPECTED TO BE QUITE LIGHT...DID LEAVE VSBYS AT KRST/KLSE AS P6SM TONIGHT. WITH SOME DIURNAL WARMING/ MIXING...CIGS IN THE BAND OF DEEPER MOISTURE EXPECTED TO RISE TODAY. THUS ONLY BROUGHT CIGS DOWN TO THE 1500-2500 FT RANGE AT THE TAF SITES WITH THE -RA/-SHRA TONIGHT. A BIT DIFFICULT TO TIME...BUT DECREASING CLOUDS/CLEARING SHOULD SPREAD INTO THE NORTHWEST END OF THE FCST AREA LATE TONIGHT...THEN QUICKLY SOUTHEAST ACROSS AREA MON MORNING. INTRODUCED SCT CLOUDS AT KRST AT 10Z...WITH THIS LOOKING TO REACH KLSE AROUND 14Z MON. GOOD VFR CONDITIONS THEN EXPECTED AT KRST/KLSE FOR MOST OF THE MON-FRI PERIOD...BUT FOR THE SMALL POSSIBILITY OF SOME VALLEY BR/FG TUE MORNING. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM....BAUMGARDT AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
115 PM EDT SUN OCT 6 2013 .SYNOPSIS... ISSUED AT 356 AM EDT SUN OCT 6 2013 A COLD FRONT WILL CROSS THE REGION TODAY WITH WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS. HEAVY RAINFALL WILL BE POSSIBLE ALONG AND EAST OF I-69. THE CHANCE OF SHOWERS WILL THEN CONTINUE INTO TOMORROW WITH MUCH COLDER AIR ARRIVING FOR EARLY NEXT WEEK. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 356 AM EDT SUN OCT 6 2013 LATEST WATER VAPOR LOOP SHOWS CENTRAL CONUS "BOWLING BALL" OF VERY STRONG VORTICITY IS CURRENTLY ENTERING IOWA AND SLOWLY PROGRESSING EASTWARD. CORRESPONDINGLY...THE EASTERN EDGE OF MERIDIONAL 100+ KT UPPER LEVEL JET IS ENTERING EASTERN ILLINOIS WITH THE BAND OF ENHANCED 925-850MB FGEN ENTERING NORTHWEST INDIANA. TIGHTENING OF LOW LEVEL HEIGHT GRADIENT HAS ALSO SUPPORTED THE DEVELOPMENT OF A 50 KT LLJ CURRENTLY SURGING NORTHWARD THROUGH CENTRAL INDIANA. STRONG MOISTURE FLUX CONVERGENCE ON THE NOSE OF THIS JET IS LEADING TO AN INCREASE IN BOTH COVERAGE AND INTENSITY OF RAINFALL LOCALLY. WIDESPREAD SHOWERS AND THUNDERSTORMS ALSO BEING SUPPORTED BY GOOD 305K ISENTROPIC ASCENT AHEAD OF THE COLD FRONT AND SEVERAL SMALL SCALE...CONVECTIVELY INDUCED...VORTICITY MAXIMA LIFTING NORTH THROUGH THE REGION. LATEST BUFR SOUNDINGS AND RAP MESOANALYSIS ALSO SHOW A FEW HUNDRED J/KG OF ELEVATED INSTABILITY...NOT ENOUGH FOR SEVERE WEATHER CONCERNS BUT THE ADDED BUOYANCY IS FURTHER AIDING UVM`S IN AN ALREADY RESPECTABLE REGION OF SYNOPTIC FORCING. MOISTURE QUALITY IS EXCELLENT...BY OCTOBER STANDARDS ANYWAY...WITH PW VALUES HOVERING AROUND 1.75 INCHES. LOW CAPE DENSITY AND HIGH FREEZING LEVELS/DEEP WARM CLOUD LAYER ARE ALSO PROMOTING HIGHLY EFFICIENT WARM RAIN PROCESSES AND MEAN FLOW ALOFT NEARLY PARALLEL TO THE FRONT RAISES THE CONCERN FOR TRAINING OF STORMS AND POTENTIALLY HEAVY RAINFALL. ONLY FLY IN THE OINTMENT IS FASTER SYSTEM SPEED NOTED IN PREVIOUS DISCUSSION. 00Z NWP SUITE CONTINUES TO SHOW MORE PHASING WITH THE TROUGH DIVING INTO CENTRAL ONTARIO AND A QUICKER EXIT OF STRONG FRONTAL PRECIP LOCALLY. LATEST SURFACE OBSERVATIONS EVEN SHOW THE COLD FRONT IS ALREADY CLOSING IN ON OUR WESTERN COUNTIES. STILL EXPECT A FAIR AMOUNT OF RAINFALL...ESPECIALLY IN OUR EASTERN COUNTIES...BUT THE LIKELIHOOD OF PRODIGIOUS AMOUNTS SUGGESTED BY SOME OF LAST NIGHTS MODEL RUNS HAS DECREASED. NAM12 IS STILL SHOWING SOME HINTS OF SURFACE WAVE DEVELOPMENT ALONG THE FRONT LATER THIS EVENING BUT IS MUCH MORE PROGRESSIVE THAN LAST NIGHT AND KEEPS THE LONGEST DURATION/HEAVIEST RAINFALL IN THE FAR EASTERN EDGES OF OUR CWA. MEANWHILE OUR WESTERN COUNTIES WILL ONLY SEE A BRIEF SHOT AT RAINFALL THIS MORNING...LIKELY ENDING AROUND MIDDAY...AND SEVERELY LIMITING ADDITIONAL RAINFALL TOTALS. PRECIP WILL CONTINUE IN OUR EASTERN COUNTIES THROUGH THE EVENING AND GIVEN THE AFOREMENTIONED INGREDIENTS FOR HEAVY RAINFALL THERE IS STILL THE POTENTIAL FOR AN ADDITIONAL 1-2 INCHES EAST OF I-69. GIVEN SOME AREAS OF NORTHWEST OHIO HAVE ALREADY SEEN 1-3 INCHES OF RAIN OVER THE PAST 36 HOURS...INHERITED FLASH FLOOD WATCH STILL LOOKS GOOD AND NO CHANGES NECESSARY AT THE MOMENT. LATER SHIFTS MAY BE ABLE TO CANCEL THE WATCH EARLY GIVEN FASTER EXIT OF PRECIP AND LOWER QPF TOTALS. WITH REGARD TO THE SEVERE WEATHER POTENTIAL...FASTER FRONTAL PASSAGE AND COPIOUS PREFRONTAL CLOUDS/PRECIP WILL SEVERELY LIMIT ANY DIURNAL GAIN IN INSTABILITY. MODELS SUGGEST 1000 J/KG AT BEST...CONFINED TO OUR OHIO COUNTIES WITH GENERALLY MOIST ADIABATIC LAPSE RATES ALOFT. VERY STRONG LOW LEVEL WIND/SHEAR PROFILES DO RAISE THE CONCERN FOR DAMAGING WIND GUSTS AND POSSIBLE TORNADOES BUT STABLE ENVIRONMENT WILL BE A SIGNIFICANT LIMITING FACTOR AND EXPECT JUST A SLIGHT CHANCE FOR SEVERE WEATHER...AND ONLY IN OUR OHIO COUNTIES. AIRMASS BEHIND COLD FRONT IS NOT PARTICULARLY COLD BY OCTOBER STANDARDS BUT IS QUITE A BIT COOLER THAN WHAT WE HAVE EXPERIENCED RECENTLY. CAA WILL GRADUALLY SEND 850MB TEMPS BACK INTO THE MID...AND EVENTUALLY LOW...SINGLE DIGITS. THUS EXPECT DAYTIME HIGHS TO REMAIN SIMILAR TO CURRENT VALUES. COLDER AIR WILL SPILL INTO THE CWA BY LATE AFTERNOON AND TEMPS WILL GRADUALLY DROP INTO THE MID TO UPPER 40S BY TONIGHT. MIDLEVEL DRY SLOT MAY BRING A TEMPORARY END TO PRECIP FROM WEST-EAST BY LATER TODAY BUT EXPECT THERE WILL STILL BE A FAIR AMOUNT OF LOW CLOUDS THROUGH THE OVERNIGHT WITH PERHAPS SOME LIGHT...DEFORMATION-FORCED PRECIP RETURNING BY THE EARLY MORNING HOURS. && .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 356 AM EDT SUN OCT 6 2013 INTENSE CLOSED LOW OVR WRN IA WILL SWING EWD ACRS THE GREAT LAKES SHRT TERM AND OPEN UP ON MON AS IT ACCELERATE NEWD THROUGH THE ST LAW VALLEY. LINGERING SHRA XPCD ESP NORTH WITHIN RESIDUAL BUT RAPIDLY WKNG TROWAL/DEFORMATION ZONE AS COLD POCKET ALOFT CROSSES OVERHEAD MON MORNING. OTRWS SFC RIDGE BLDS EWD OUT OF THE ROCKIES IN THIS SYS/S WAKE W/SEASONABLY COOL TEMPS TO START THE WORKWEEK BUT MODERATING TO BACK ABV NORMAL BY WED AS DOWNSTREAM RIDGING DVLPS IN EARNEST IN RESPONSE TO RENEWED DEEP WRN TROUGH DVLPMNT. THIS NXT SYS XPCD TO LIFT OUT WELL WWD OF WRN GREAT LAKES W/DRY WX XPCD LOCALLY THROUGH AT LEAST DY7 (SAT). && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING) ISSUED AT 115 PM EDT SUN OCT 6 2013 FINE LINE ON KIWX RADAR DEPICTING FRONTAL PASSAGE AT KFWA ATTM WHILE BACK EDGE OF PRECIP NOW EXITING KSBN AREA. PLENTY OF IFR CIGS ALONG WITH MVFR/IFR VSBYS INDICATED WEST OF KFWA SO WILL INCLUDE 2HR TEMPO GROUP TO ACCT FOR THIS UNTIL PRECIP MOVES OUT BY 20Z. WATER VAPOR IMAGERY SHOWING DRY SLOT NOW WORKING INTO WESTERN INDIANA WITH CLOSED UPPER LOW STILL WELL TO THE WEST IN EASTERN IOWA. EVEN WITH ADDL WRAP AROUND MOISTURE EXPECTED TO MOVE BACK INTO THE AREA OVERNIGHT...UPSTREAM OBS INDICATING VFR CONDITIONS CAN BE EXPECTED AT BOTH LOCATIONS OVERNIGHT AND THRU THE END OF THE TAF PERIOD. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR INZ007-009-018-026- 027-033-034. MI...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR MIZ081. OH...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR OHZ001-002-004-005- 015-016-024-025. LM...NONE. && $$ SYNOPSIS...AGD SHORT TERM...AGD LONG TERM...T AVIATION...JAL VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DULUTH MN
331 PM CDT SUN OCT 6 2013 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 329 PM CDT SUN OCT 6 2013 MID LEVEL DEFORMATION ZONE EVIDENT ON SATELLITE AND RADAR ACROSS THE CWA. A LINE OF LIGHT RAIN/DRIZZLE EXTENDED FROM THE ARROWHEAD THROUGH AITKIN INTO SOUTHWEST MINNESOTA. THE HRRR HAS BEEN SHOWING THIS BAND DEVELOPING TODAY...BUT WAS A BIT TOO STRONG AND SLOW WITH IT. WE HAVE CHANCE FOR RAIN OVER OUR FAR EASTERN MN CWA AND NORTHWEST WISCONSIN THIS EVENING...AND DIMINISH OVERNIGHT. ANY RAINFALL SHOULD BE RATHER LIGHT...FROM A TRACE TO A COUPLE HUNDREDTHS OF AN INCH. CLEARING WAS ALSO WORKING INTO OUR WESTERN CWA...AND THAT SHOULD CONTINUE AS WELL THROUGH THE NIGHT. WE DO DECREASE SKY COVER TO CLEAR TO PARTLY CLOUDY OVERNIGHT...WITH LOWS IN THE MID THIRTIES TO AROUND FORTY. WE DO NOT EXPECT WINDS TO DECOUPLE OVER A LARGE AREA...BUT A FEW FAVORED LOCATIONS LIKELY WILL SUCH AS KHIB/KBFW AND WE LOWERED TEMPS A BIT MORE THERE. SURFACE HIGH PRESSURE WILL LEAD TO PARTLY TO MOSTLY SUNNY SKIES MONDAY WITH TEMPERATURES WARMING INTO THE UPPER FIFTIES TO LOWER SIXTIES. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 329 PM CDT SUN OCT 6 2013 THE WESTERN GREAT LAKES REGION WILL BE SITUATED BETWEEN THE DEPARTING RIDGE AND AN APPROACHING NEGATIVELY TILTED LONG WAVE TROUGH THROUGH THE TUESDAY-FRIDAY TIME FRAME. THIS WILL RESULT IN AN INCREASING SW FLOW WITH A RETURN TO UNSEASONABLY WARM H92-H85 TEMPS BY MID WEEK. HAVE INCREASED THE SOUTH WINDS TUESDAY AS LATEST MODEL RUNS ARE IN GOOD AGREEMENT THAT A 40-50 KT LLJ PUSHES OVER MINNESOTA THROUGH TUESDAY AFTERNOON. LATEST NAM BUFR SOUNDINGS AT LOCATIONS ACROSS THE DLH CWA SHOW WINDS AROUND 35 KT IN THE MIX LAYER TUESDAY AFTERNOON AS TEMPERATURES ARE EXPECTED TO WARM INTO THE UPPER 60 TO LOW 70S. HOWEVER...HIGHER GUSTS TO 40 KT ARE NOT OUT OF THE QUESTION IF TEMPERATURES WARM JUST A FEW DEGREES HIGHER ALLOWING FOR DEEPER MIXING. RAIN CHANCES RETURN TO THE FCST FRIDAY NIGHT/SATURDAY AS A STRONG VORT MAX /WITH CLOSED H85-H50 LOW/ ROUNDS THE BASE OF THE LONG WAVE TROUGH AND LIFTS INTO THE UPPER MIDWEST. THIS LOW WILL BRING CLOUDS AND ONGOING RAIN CHANCES TO THE NORTHLAND THROUGH MUCH OF THE UPCOMING WEEKEND. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1234 PM CDT SUN OCT 6 2013 A LARGE AREA OF LOW CLOUDS/DRIZZLE AND IFR/LIFR CEILINGS IS FOUND ACROSS THE WESTERN GREAT LAKES REGION. AT 100 PM...THE BACK EDGE OF THE CLOUDS WAS SEEN ON SATELLITE IMAGERY EXTENDING FROM KBRD....SOUTHWEST TO KDTL AND KYKN. THE CLEARING LINE WILL VERY SLOWLY TRACK EAST THROUGH THE TAF. THE KINL AREA WILL SEE THE RETURN OF VFR CIGS BY 20Z...REACHING KBRD IN THE LATE AFTERNOON...AND FINALLY KHYR AFTER MIDNIGHT. && .PRELIMINARY POINT TEMPS/POPS... DLH 39 60 42 67 / 10 0 0 0 INL 37 61 41 69 / 0 0 0 0 BRD 39 64 44 72 / 0 0 0 0 HYR 39 61 39 70 / 30 10 0 0 ASX 42 61 43 70 / 50 10 0 0 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. && $$ SHORT TERM...MELDE LONG TERM...GRANING AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
219 PM EDT SUN OCT 6 2013 .SYNOPSIS... A STATIONARY FRONT...CURRENTLY NEAR THE NEW YORK PENNSYLVANIA BORDER...WILL GRADUALLY LIFT NORTH AS A WARM FRONT TODAY. THIS WILL KEEP OUR WEATHER UNSETTLED WITH SCATTERED SHOWERS AND THUNDERSTORMS. A STRONG COLD FRONT WILL CROSS THE REGION ON MONDAY WITH MORE SHOWERS AND THUNDERSTORMS ALONG WITH THE POSSIBILITY OF HEAVY RAIN. HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY WITH FAIR WEATHER EXPECTED TO CONTINUE THROUGH THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... S/WV...MOST EVIDENT IN THE 700 MB WIND FIELD OVER WRN NY...AND NEARLY STNRY FNTL BNDRY ACRS THE TWIN TIERS...HELPING TO TRIGGER SCT SHRA/TSRA ACRS THE FCST AREA. RUC INDICATES THAT ANOTHER WEAK S/WV OVER SW PA WILL MAKE A RUN TWDS THE SRN TIER TWDS MRNG WHICH MAY TRIGGER MORE SCT ACTIVITY. 925-850 RH`S SUGGEST THE CNTRL SRN TIER AND FINGER LAKES BREAK OUT THIS AFTN (ALSO PORTIONS OF NE PA) LOW CLD AND COOLER TEMPS XPCTD ACRS ERN ZONES...PRIMARILY THE CATSKILLS...ERN SUSQ RGN AND WRN MOHAWK VLY WHERE MOIST LOW LVL SELY FLOW HELPS KEEP MSTR LOCKED IN. INTERESTINGLY..THE LCL WRF SUGGESTS THAT DIFF HEATING DUE TO THESE CLDS MAY HELP TO TRIGGER SCT TSRA OVER THE FINGER LAKES AND CNTRL SRN TIER THIS AFTN. WILL KEEP HIEST POPS ACRS NRN ZONES TDA...WITH MAXES FROM THE U70S WRN ZONES TO M/U60S ACRS PORTIONS OF THE CATSKILLS. A RELATIVE LACK OF PCPN IS XPCTD TNGT. PROFILES SUGGEST THAT SELY FLOW WILL ADVECT LOW CLDS/STRATUS BACK INTO THE FCST AREA OVRNGT. LOWS WILL BE VERY MILD...FROM THE MID AND PSBLY U60S ACRS THE FINGER LAKES...TO AROUND 60 IN FAR EAST. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... SIG CHGS MADE TO THE SHORT TERM GIVEN GOOD AGREEMENT BETWEEN THE 00Z GFS AND 12Z EURO...WHICH ADVERTISED A QUICKER PROGRESSION OF THE FNT/UPR TROF THRU THE FCST AREA. LOOKING AT WATER VAPOR IMAGERY THIS MRNG...IT APPEARS LIKELY THAT NRN STREAM S/WV WILL GIVE THIS SYSTEM A NUDGE AND KEEP IT PROGRESSIVE AS IT MOVS NEWD. THEREFORE WE SPED UP THE FNTL TIMING...XPCTNG IT TO PASS ON MONDAY. THIS WILL REDUCE THE POTNL FOR FLOODING PRBLMS...BUT WITH PW`S IN THE 1.5 TO 1.75 RNG...+RA WILL BE PSBL IN ADDITION TO EMBEDDED TSRA. TEMPS LIKELY TO BE FALLING SPCLY W OF I-81 DURING THE AFTN POST FROPA. POTNL FOR SOME -SHRA ACRS FAR NRN ZONES DUE TO LINGERING EFFECTS OF THE UPR TROF AND NW FLOW. HI PRES WILL BUILD INTO THE REGION FROM THE OH VLY/GTLAKES ON TUE...WITH MRNG CLDS GIVING WAY TO A MOSTLY SUNNY DAY AS RIDGING OCCURS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... EXTENDED PERIOD WILL FEATURE PLEASANT FALL WEATHER AS HIGH PRESSURE BOTH AT THE SFC AND ALOFT RESIDES OVER THE NORTHEAST. MODELS INDICATE A SYSTEM OFF THE MID ATLANTIC COAST WITHIN THE STRONG UPPER LEVEL RIDGE BUT THE MOISTURE ASSOCIATED WITH THIS SYSTEM SHOULD REMAIN WELL SOUTH OF FORECAST AREA. WILL CONTINUE WITH DRY WEATHER THROUGH THE PERIOD. LOW TEMPERATURES WILL BE NEAR SEASONAL LEVELS GENERALLY UPPER 30S TO MIDDLE 40S WHILE THE HIGHS WILL RUN 5 TO 10 DEGREES ABOVE NORMAL WITH MAXES FROM THE MID 60S TO AROUND 70. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... SFC WARM FRONT IS CURRENTLY LIFTING NORTH OF THE AREA ALONG WITH THE SHOWERS. MVFR CIGS MAY PERSIST OVER THE KRME/KSYR TERMINALS THROUGH MID AFTERNOON BUT IN GENERAL CONDITIONS WILL IMPROVE TO VFR. ACROSS THE REST OF THE TERMINALS CONDITIONS ARE CURRENTLY VFR AND EXPECTED TO PERSIST UNTIL LATER THIS EVENING. MOIST SOUTHEAST FLOW OVERNIGHT WILL BRING MVFR CIGS BACK ACROSS TERMINALS BEFORE 06Z WITH ALL TERMINALS BUT KSYR OCCASIONALLY FALLING BELOW IFR ESPECIALLY BETWEEN 08Z-12Z. MONDAY MORNING A STRONG COLD FRONT WILL CROSS THE REGION BETWEEN MID MORNING AND EARLY AFTERNOON. FOR KSYR/KITH/KELM INCLUDED MVFR SHOWERS WITH HEAVY RAIN BEGINNING AROUND 14Z-16Z. THIS ACTIVITY WAS NOT INCLUDED IN THE KRME/KBGM/KAVP TERMINALS AS FRONT WILL JUST REACH AIRPORTS AT OR JUST SLIGHTLY AFTER 18Z WITH SIMILAR CONDITIONS EXPECTED. SOUTH WINDS THROUGH LATE AFTERNOON AT 10 KNOTS WITH GUSTS AROUND 20 KNOTS. SOUTHEAST WINDS OVERNIGHT AT 5-10 KNOTS BECOMING SOUTHWEST AND GUSTY MONDAY MORNING. OUTLOOK... MON NIGHT...SHOWERS WILL BE EAST OF AREA BUT MVFR CIG RESTRICTIONS ARE POSSIBLE. TUE THRU FRIDAY...VFR WITH THE EXCEPTION OF VALLEY FOG ACROSS THE SOUTHERN TIER EACH MORNING. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM...RRM AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1228 PM EDT SUN OCT 6 2013 .SYNOPSIS... A STATIONARY FRONT...CURRENTLY NEAR THE NEW YORK PENNSYLVANIA BORDER...WILL GRADUALLY LIFT NORTH AS A WARM FRONT TODAY. THIS WILL KEEP OUR WEATHER UNSETTLED WITH SCATTERED SHOWERS AND THUNDERSTORMS. A STRONG COLD FRONT WILL CROSS THE REGION ON MONDAY WITH MORE SHOWERS AND THUNDERSTORMS ALONG WITH THE POSSIBILITY OF HEAVY RAIN. HIGH PRESSURE WILL BUILD INTO THE REGION ON TUESDAY WITH FAIR WEATHER EXPECTED TO CONTINUE THROUGH THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... S/WV...MOST EVIDENT IN THE 700 MB WIND FIELD OVER WRN NY...AND NEARLY STNRY FNTL BNDRY ACRS THE TWIN TIERS...HELPING TO TRIGGER SCT SHRA/TSRA ACRS THE FCST AREA. RUC INDICATES THAT ANOTHER WEAK S/WV OVER SW PA WILL MAKE A RUN TWDS THE SRN TIER TWDS MRNG WHICH MAY TRIGGER MORE SCT ACTIVITY. 925-850 RH`S SUGGEST THE CNTRL SRN TIER AND FINGER LAKES BREAK OUT THIS AFTN (ALSO PORTIONS OF NE PA) LOW CLD AND COOLER TEMPS XPCTD ACRS ERN ZONES...PRIMARILY THE CATSKILLS...ERN SUSQ RGN AND WRN MOHAWK VLY WHERE MOIST LOW LVL SELY FLOW HELPS KEEP MSTR LOCKED IN. INTERESTINGLY..THE LCL WRF SUGGESTS THAT DIFF HEATING DUE TO THESE CLDS MAY HELP TO TRIGGER SCT TSRA OVER THE FINGER LAKES AND CNTRL SRN TIER THIS AFTN. WILL KEEP HIEST POPS ACRS NRN ZONES TDA...WITH MAXES FROM THE U70S WRN ZONES TO M/U60S ACRS PORTIONS OF THE CATSKILLS. A RELATIVE LACK OF PCPN IS XPCTD TNGT. PROFILES SUGGEST THAT SELY FLOW WILL ADVECT LOW CLDS/STRATUS BACK INTO THE FCST AREA OVRNGT. LOWS WILL BE VERY MILD...FROM THE MID AND PSBLY U60S ACRS THE FINGER LAKES...TO AROUND 60 IN FAR EAST. && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... SIG CHGS MADE TO THE SHORT TERM GIVEN GOOD AGREEMENT BETWEEN THE 00Z GFS AND 12Z EURO...WHICH ADVERTISED A QUICKER PROGRESSION OF THE FNT/UPR TROF THRU THE FCST AREA. LOOKING AT WATER VAPOR IMAGERY THIS MRNG...IT APPEARS LIKELY THAT NRN STREAM S/WV WILL GIVE THIS SYSTEM A NUDGE AND KEEP IT PROGRESSIVE AS IT MOVS NEWD. THEREFORE WE SPED UP THE FNTL TIMING...XPCTNG IT TO PASS ON MONDAY. THIS WILL REDUCE THE POTNL FOR FLOODING PRBLMS...BUT WITH PW`S IN THE 1.5 TO 1.75 RNG...+RA WILL BE PSBL IN ADDITION TO EMBEDDED TSRA. TEMPS LIKELY TO BE FALLING SPCLY W OF I-81 DURING THE AFTN POST FROPA. POTNL FOR SOME -SHRA ACRS FAR NRN ZONES DUE TO LINGERING EFFECTS OF THE UPR TROF AND NW FLOW. HI PRES WILL BUILD INTO THE REGION FROM THE OH VLY/GTLAKES ON TUE...WITH MRNG CLDS GIVING WAY TO A MOSTLY SUNNY DAY AS RIDGING OCCURS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... EXTENDED PERIOD WILL FEATURE PLEASANT FALL WEATHER AS HIGH PRESSURE BOTH AT THE SFC AND ALOFT RESIDES OVER THE NORTHEAST. MODELS INDICATE A SYSTEM OFF THE MID ATLANTIC COAST WITHIN THE STRONG UPPER LEVEL RIDGE BUT THE MOISTURE ASSOCIATED WITH THIS SYSTEM SHOULD REMAIN WELL SOUTH OF FORECAST AREA. WILL CONTINUE WITH DRY WEATHER THROUGH THE PERIOD. LOW TEMPERATURES WILL BE NEAR SEASONAL LEVELS GENERALLY UPPER 30S TO MIDDLE 40S WHILE THE HIGHS WILL RUN 5 TO 10 DEGREES ABOVE NORMAL WITH MAXES FROM THE MID 60S TO AROUND 70. && .AVIATION /16Z SUNDAY THROUGH THURSDAY/... 12Z UPDATE... FRONTAL BOUNDARY CONTINUES TO SIT ACROSS THE AREA LEADING TO MVFR/IFR CONDITIONS THIS MORNING. POTENTIAL EXISTS FOR KBGM TO DROP BELOW AIRFIELD MINIMUMS BETWEEN 12Z AND 13Z. RESTRICTIONS SHOULD RISE TO VFR/MVFR AFTER 15Z THIS MORNING, WITH VFR AT KAVP AND MVFR AT NY TERMINALS ALONG AND JUST NORTH OF FRONTAL BOUNDARY. AREA OF SHOWERS IS MOVING NORTHEAST THIS MORNING AND SHOULD IMPACT KELM AND KITH BETWEEN 12Z AND 13Z THEN MOVING INTO KSYR/KRME TERMINALS BETWEEN 13Z AND 15Z. TRIED TO INDICATE BEST CHANCE FOR SHOWERS WITH RME/SYR EXPERIENCING SHOWERS BETWEEN 18Z AND 23Z AND KELM/KITH AND KBGM BETWEEN 15Z AND 19Z. HOWEVER, SHOWERS MAY DEVELOP AT ANYTIME AND POSSIBLY THUNDER AS WELL. AFTER 06Z TONIGHT AT KRME AND KSYR CONDITIONS SHOULD BECOME VFR THOUGH STILL A CHANCE FOR LOW CIGS. FURTHER TO THE SOUTH LOW MVFR AND IFR WILL EXIST TOWARD END OF TAF VALID TIME AS LOW LEVEL MOISTURE POOLS AHEAD OF APPROACHING COLD FRONT. LGT SRLY SFC WINDS EARLY...WILL INCREASE TO 8-12 KT. OUTLOOK... MON THRU TUE...AN UNSETTLED PERIOD...WITH SCATTERED TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF RESTRICTIVE CONDS FROM TIME TO TIME. TUE NGT THRU THUR...MAINLY VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM...RRM AVIATION...PVN
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
403 PM EDT SUN OCT 6 2013 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE WEST. THE FRONT WILL MOVE ACROSS THE AREA MONDAY NIGHT...THEN STALL OFFSHORE. COOL HIGH PRESSURE WILL BUILD OVER THE AREA TUESDAY...AND EXTEND OVER THE AREA FROM THE NORTH THROUGH LATE WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... AS OF 320 PM SUNDAY...LIGHT TO MODERATE SHOWERS CONTINUE TO SPREAD FROM SOUTH TO NORTH ALONG AN AXIS OF HIGHER PRECIPITABLE WATERS OVER OUR WESTERN CWA. THE 3 KM HRRR MODEL HAS A PRETTY GOOD HANDLE ON THIS AND HAVE KEPT CHANCE POPS GOING INTO THIS EVENING MAINLY WEST OF THE HIGHWAY 17 CORRIDOR. THE AXIS OF HIGH MOISTURE MOVES TO THE COAST LATER TONIGHT AND HAVE LOW POPS COASTAL SECTIONS FROM 00Z TO 06Z BEFORE INCREASING MOISTURE AHEAD OF THE FRONT LEADS TO POPS AREA-WIDE TOWARD MORNING. INCREASED CLOUD COVER AND MOISTURE SHOULD HOLD MINIMUM TEMPERATURES IN THE 65 TO 70 DEGREE RANGE. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... AS OF 320 PM SUN...AS THE COLD FRONT APPROACHES SLOWLY FROM THE WEST ON MONDAY...LOW-LEVEL MOISTURE FLUX INCREASES THROUGH THE DAY FROM WEST TO EAST. HAVE LIKELY POPS MOVING FROM WEST TO EAST AS THE DAY WEARS ON. THERE IS SUFFICIENT INSTABILITY WITH LI`S IN THE -2 TO -3 RANGE...FOR A FEW GUSTY THUNDERSTORMS DURING THE AFTERNOON AND EVENING HOURS. QPF TOTALS SHOULD GENERALLY BE IN THE ONE QUARTER TO ONE HALF INCH RANGE...ALTHOUGH THERE COULD BE HEAVIER AMOUNTS IN A FEW DOWNPOURS. CLOUDS AND PRECIPITATION SHOULD HOLD MAXIMUM TEMPERATURES IN THE LOWER 80S. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... AS OF 4 PM SUNDAY...LONG TERM PERIOD WILL FEATURE UNSETTLED WEATHER AND COOLER TEMPERATURES. PARENT UPPER LOW OVER THE MID MISSISSIPPI VALLEY TODAY WILL BE SHUNTED OFF TO THE NORTH AND EAST WITH NORTHERN JET STREAM EARLY THIS WEEK. MODELS HAVE BEEN COMING INTO BETTER AGREEMENT ON A PIECE OF ENERGY BECOMING LEFT BEHIND AND MEANDERING OVER THE SOUTHEAST CONUS THROUGH AT LEAST MID WEEK. THIS FEATURE WILL BRING THE AREA UNSETTLED WEATHER IN THE FORM OF SHOWERS AND PLENTIFUL CLOUD COVER. THIS THINKING BASED ON BULK OF SPAGHETTI MODELS INDICATING CLOSED OR CUT OFF H580-582M LOW IN WEAK SOUTHERN STREAM FLOW. AT THE SAME TIME...A SFC REFLECTION LOOKS TO DEVELOP OFF THE SE TO MID ATLANTIC COAST AND MEANDER JUST OFFSHORE THROUGH THE PERIOD... BRINGING A PROLONGED PERIOD OF GUSTY NE WINDS TO THE COASTAL OBX AREAS. HAVE RAISED POPS TO LIKELY SOUTHERN/EASTERN ZONES ON TUE WITH HIGH CHANCE FURTHER NORTH AND WEST. FOR WED...CAPPED POPS BELOW LIKELY THOUGH IF WETTER TREND HOLDS THEY WILL NEED TO BE RAISED AS WELL. UPPER LOW MAY DRIFT NORTH BY LATE WEEK TAKING BEST SHOWER CHANCES WITH IT. BEST POPS WILL RESIDE IN THE NORTHEAST DURING THIS PERIOD. FOR TEMPS...IT WILL BE BELOW CLIMO...ESP FOR MAX T`S AS CLOUDS AND SHOWERS HOLD TEMPS DOWN INTO THE UPPER 60S TO NEAR 70 INLAND. LOWS WILL GENERALLY BE IN THE 50S. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... SHORT TERM /TONIGHT AND MONDAY/... AS OF 330 PM SUNDAY...WITH AXIS OF HIGHER MOISTURE OVER OUR WESTERN CWA...KOAJ AND KISO AND PERHAPS KPGV WILL SEE SOME PASSING SHOWERS OVER THE NEXT FEW HOURS AND WILL INCLUDE A VICINITY SHOWER IN THE EARLY PORTION OF THE TAF FOR THESE SITES. MOS GDNC IS INDICATING ANOTHER PERIOD OF IFR/LIFR CIGS/VSBYS LATE TONIGHT...BUT WINDS NOT EXPECTED TO DECOUPLE...AND LIGHT SRLY FLOW LIKELY TO RESULT IN STRATUS CIGS NEAR 1K FT. MORE WIDESPREAD SHOWERS AND A FEW GUSTY THUNDERSTORMS ARE EXPECTED MONDAY WITH OCCASIONAL MVFR CEILINGS AND VSBYS POSSIBLE. LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 330 PM SUN...COLD FRONT WILL SWEEP THROUGH E NC MON NIGHT WITH WIDESPREAD SHOWERS AND AN ISO THUNDERSTORM. CIGS WILL DROP TO MVFR TO POTENTIALLY IFR MON NIGHT. IFR CONDITIONS LOOK LIKELY TUE THROUGH MID WEEK AS MOIST NORTHEAST FLOW DEVELOPS WITH UPPER LOW LINGERING OVER THE VICINITY. WINDS WILL BE GUSTY AT TIMES AS WELL WITH HIGH PRES INLAND AND LOW PRES OVER THE WATERS PRODUCING TIGHT GRADIENT. && .MARINE... SHORT TERM /TONIGHT AND MONDAY/... AS OF 330 PM SUNDAY...S/SE WINDS AT 10 TO 15 KNOTS SHOULD PREVAIL THROUGH THIS EVENING...THEN INCREASE TO 15 TO 20 KNOTS LATE AS GRADIENT TIGHTENS AHEAD OF COLD FRONT. PER LOCAL NWPS MODEL...SEAS SHOULD BUILD TO 4 TO 6 FEET AFTER MIDNIGHT FOR ALL BUT THE FAR NORTHERN WATERS. WITH PERSISTENT SOUTHERLY WINDS IN THE 15 TO 20 KNOT RANGE ON MONDAY...SEAS BUILD TO 5 TO 7 FEET OVER THE COASTAL WATERS. HAVE ADJUSTED THE SMALL CRAFT ADVISORY TO START A BIT EARLIER AT AROUND 08Z OR SO TONIGHT AND CONTINUE THROUGH THE DAY ON MONDAY. LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 330 PM SUN...DETERIORATING BOATING CONDITIONS LATE MON NIGHT AS A SHARP COLD FRONT PASSES THROUGH THE WATERS. WINDS WILL TURN SHARPLY NORTHEAST FOR THE NORTHERN WATERS LATE NIGHT...WITH THE SURGE REACHING THE SOUTHERN WATERS BY TUE MORNING. SEAS WILL RESPOND BY BUILDING TO ABOVE 6 FEET. THE NORTHEAST SURGE WILL BE PROLONGED THROUGH THE END OF THE WEEK AS HIGH PRES WILL BE WEDGED ACROSS THE INTERIOR CAROLINAS WITH PERSISTENT LOW PRES OFF THE COAST. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 9 PM EDT MONDAY FOR AMZ150-152- 154-156-158. && $$ SYNOPSIS...CTC NEAR TERM...CTC SHORT TERM...CTC LONG TERM...TL AVIATION...CTC/TL MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1245 PM CDT SUN OCT 6 2013 .UPDATE... ISSUED AT 1245 PM CDT SUN OCT 6 2013 EARLY AFTERNOON UPDATE PRIMARILY FOR ADDITION OF AVIATION DISCUSSION. TEMPERATURES AND CLOUD TRENDS ON TRACK. NOT A LOT OF CONFIDENCE ON HOW MUCH CLOUD INCREASE NEEDED FOR BAND ACROSS SOUTHEASTERN SASK AND WEST CNTRL MB AS IT APPEARS TO BE DRYING UP QUITE A BIT WHILE ADVECTING EAST. WILL KEEP SKY COVER IN THE 40 TO 50 PER CENT RANGE FOR NORTHERN TIER AND REDUCE SKY COVER ELSEWHERE...WITH EXCEPTION OF SLOWLY DISSIPATING AREA ACROSS FAR SOUTHEASTERN ZONES. UPDATE ISSUED AT 950 AM CDT SUN OCT 6 2013 MORNING UPDATE PRIMARILY FOCUSES ON SKY AND TEMPS AS WESTERN TWO THIRDS OF CWA IS NOW CLEAR WITH A BAND OF LOW CLOUDS STILL OVER EASTERN AND SOUTHEASTERN ZONES. ONLY SEEING A FEW REPORTS OF RAIN...LATEST AT DETROIT LAKES. 12Z NAM AND LATEST RAP OVERDOING PRECIP FOR THE AM...STILL PRODUCING ANOTHER TENTH OF AN INCH. EXPECT ANY MEASURABLE PRECIP TO BE MORE IN THE RANGE OF A COUPLE OF HUNDREDTHS OF AN INCH. WILL LOWER POPS SOME AND KEEP MENTION OF DRIZZLE...BUT THINK ANY PRECIP SHOULD END BY NOON TODAY. UPDATE ISSUED AT 703 AM CDT SUN OCT 6 2013 RADAR STILL INDICATING A NARROW BAND OF LIGHT RAIN/SPRINKLES FROM FERTILE MN TO FAR TO GWINNER ND. BAND WAS SHIFTING SOUTH AT 5 KNOTS. EXPECT RAIN TO CONTINUE TO DIMINISH AND SHIFT SOUTH. WILL LET FREEZE WARNING/FROST ADVISORY EXPIRE AT 9 AM CDT. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 401 AM CDT SUN OCT 6 2013 THE NAM WAS THE FAST MODEL WITH THE ECMWF AND GEM SLOWER AND THE GFS THE SLOWEST MODEL RUN. WILL PREFER THE GFS AND ECMWF. UPPER AIR PATTERN REMAINS PROGRESSIVE. WATER VAPOR LOOP INDICATED UPPER LEVEL RIDGE AXIS OVER THE PACIFIC NORTHWEST. RIDGE FORECAST TO MOVE ACROSS THE NORTHERN PLAINS BY TUE MORNING. RADAR INDICATED PRECIPITATION WAS DECREASING IN AREA AND INTENSITY AND WAS IN A NARROW BAND FROM NEAR BDE TO FORMAN ND. INDIVIDUAL CELLS WERE MOVING TO THE SOUTHWEST ABOUT 45 KNOTS WHILE THE BAND WAS MOVING WEST ABOUT 4 KNOTS. MODELS REDUCE QPF TO AROUND A HUNDRED OF AN INCH...ESSENTIALLY ZERO...AFTER 12Z SUN. ALSO MODELS SIGNIFICANTLY DECREASE THE MID LEVEL RH FIELD (700-500 HPA) AFTER 12Z. WILL REDUCE POPS FOR TODAY. WILL ADD DRIZZLE FOR SOUTHEAST ZONES TODAY. LITTLE ADDITIONAL PRECIPITATION EXPECTED FOR TODAY. LITTLE CHANGE TO HIGH TEMPS TODAY AND LOW TEMP TUE MORNING. WENT A COUPLE DEGREES HIGHER FOR TONIGHT AND TUE AFTERNOON. WENT COOLER NORTHEAST ZONES FOR MON HIGH AND A COUPLE DEGREES LOWER FOR WESTERN ZONES WED MORN. OTHERWISE RISING TEMPS EXPECTED FOR THE NEXT COUPLE DAYS. WILL KEEP FREEZE WARNING/FROST ADVISORY FOR NORTHWEST ZONES THIS MORNING. .LONG TERM...(MONDAY NIGHT THROUGH SATURDAY) ISSUED AT 401 AM CDT SUN OCT 6 2013 A QUIET SOUTHWEST FLOW PATTERN IS EXPECTED FOR MID-WEEK. A WEAK SFC BOUNDARY MAY BE DRAPED SOMEWHERE ACROSS THE AREA ON WEDNESDAY IN ASSOCIATION WITH AN UPPER LEVEL DISTURBANCE PASSING WELL TO THE NORTH ACROSS CANADA...BUT NOT EXPECTING ANY PRECIP WITH DRY AIR STILL IN PLACE. INCREASINGLY MOIST SOUTHERLY LOW-LEVEL FLOW WILL DEVELOP LATE WEEK AS ANOTHER STRONG UPPER LOW LIFTS OUT OF THE ROCKIES. THE 00Z GFS/ECMWF ARE IN GOOD AGREEMENT LIFTING THE UPPER LOW INTO THE NORTHERN PLAINS BY LATE FRIDAY...WITH THE ECMWF JUST A TAD SLOWER OVERALL. SHOWERS/STORMS MAY DEVELOP BY FRIDAY...WITH SOME SHOWERS POSSIBLY LINGERING INTO SATURDAY. THE 00Z ECMWF/GFS INDICATE A MORE PROGRESSIVE SOLUTION COMPARED WITH THE 12Z ECMWF...BUT WITH THE STRENGTH OF DOWNSTREAM RIDGING...SOME UNCERTAINTY EXISTS WITH THE TIMING AND PLACEMENT OF THE SYSTEM. TEMPS WILL REMAIN ABOVE NORMAL THROUGH FRIDAY...WITH HIGHS IN THE 60S AND 70S AND LOWS IN THE 40S AND 50S. TEMPS WILL TREND COOLER NEXT WEEKEND BEHIND THE SYSTEM. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1245 PM CDT SUN OCT 6 2013 IFR CIGS TO PERSIST CROSS FAR EASTERN FA (BJI TAF) FOR ANOTHER HOUR OR SO BEFORE SCATTERING OUT. REMAINDER OF THE FA WILL BE VFR WITH NO CIGS ANTICIPATED. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...SPEICHER SHORT TERM...HOPPES LONG TERM...MAKOWSKI AVIATION...VOELKER
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
511 PM CDT SUN OCT 6 2013 .UPDATE... HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO INTRODUCE A THROUGH THE LATE AFTERNOON HOURS GROUPING ALL COUNTIES TO DEAL WITH CURRENT AND EXPECTED SHORT TERM PROGRESSION OF SHWRS AND ISO TSTMS W TO E ACROSS MID STATE. TEMPS SHOULD FALL ACROSS THE ENTIRE MID STATE INTO THE UPPER 50S BY THE LATE AFTERNOON HRS. ALSO. && .PREV DISCUSSION.../ISSUED 213 PM CDT SUN OCT 6 2013/ DISCUSSION...SURFACE FRONT HAS MADE IT EAST OF NASHVILLE, WITH A BROKEN LINE OF MODERATE TO HEAVY SHOWERS OCCURRING ALONG THE BOUNDARY. HRRR DOING A REASONABLE JOB WITH ONGOING ACTIVITY, AND THE SHORT-RANGE MODEL SHOWS NUMEROUS CELLS LASTING WELL PAST 00Z. SIGNIFICANTLY COOLER AIR AND LOWER DEW POINTS ARE OBVIOUSLY RUSHING IN BEHIND THE FRONT, EVEN AS SCATTERED SHOWERS CONTINUE DEVELOPING IN THE COLD POOL. EXPECT MOST OF THE ACTIVITY TO MOVE EAST OF THE AREA BY 06Z, WITH SHOWERS EXITING THE PLATEAU BY 12Z. A BROAD RIDGE OF HIGH PRESSURE WILL QUICKLY BUILD IN AND DRY OUT THE ATMOSPHERE AND KEEP A COOLER AIR MASS LOCKED IN PLACE OVER MIDDLE TENNESSEE THE REMAINDER OF THE WEEK. NO PRECIPITATION IS EXPECTED FROM TOMORROW THROUGH THE END OF THE 7-DAY FORECAST PERIOD. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
213 PM CDT SUN OCT 6 2013 .DISCUSSION...SURFACE FRONT HAS MADE IT EAST OF NASHVILLE, WITH A BROKEN LINE OF MODERATE TO HEAVY SHOWERS OCCURRING ALONG THE BOUNDARY. HRRR DOING A REASONABLE JOB WITH ONGOING ACTIVITY, AND THE SHORT-RANGE MODEL SHOWS NUMEROUS CELLS LASTING WELL PAST 00Z. SIGNIFICANTLY COOLER AIR AND LOWER DEW POINTS ARE OBVIOUSLY RUSHING IN BEHIND THE FRONT, EVEN AS SCATTERED SHOWERS CONTINUE DEVELOPING IN THE COLD POOL. EXPECT MOST OF THE ACTIVITY TO MOVE EAST OF THE AREA BY 06Z, WITH SHOWERS EXITING THE PLATEAU BY 12Z. A BROAD RIDGE OF HIGH PRESSURE WILL QUICKLY BUILD IN AND DRY OUT THE ATMOSPHERE AND KEEP A COOLER AIR MASS LOCKED IN PLACE OVER MIDDLE TENNESSEE THE REMAINDER OF THE WEEK. NO PRECIPITATION IS EXPECTED FROM TOMORROW THROUGH THE END OF THE 7-DAY FORECAST PERIOD. && .PRELIMINARY POINT TEMPS/POPS... NASHVILLE 46 67 47 72 / 30 0 0 05 CLARKSVILLE 43 66 45 71 / 10 0 05 05 CROSSVILLE 45 63 42 68 / 80 0 05 05 COLUMBIA 46 69 47 73 / 30 0 0 05 LAWRENCEBURG 45 69 45 73 / 30 0 0 05 WAVERLY 44 67 45 72 / 10 0 05 05 && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ ROSE
AREA FORECAST DISCUSSION
NWS SEATTLE WA
931 AM PDT SUN OCT 6 2013 .SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION TODAY. LOOK FOR A FAST MOVING COLD FRONT TO SWEEP ACROSS THE AREA TONIGHT. A LOW PRESSURE SYSTEM WILL PREVAIL OVER THE REGION MONDAY AND TUESDAY FOR COOL AND UNSETTLED CONDITIONS. DRY WEATHER WILL RETURN ON WEDNESDAY. && .SHORT TERM... THERE WAS LOCALIZED LOW STRATUS AND FOG OVER THE CWA THIS MORNING. THE LOW CLOUDS AND FOG SHOULD DISSIPATE BY LATE THIS MORNING. MEANWHILE...AN UPPER RIDGE WILL REMAIN OVER THE REGION TODAY FOR CONTINUED DRY WEATHER AND NEAR OR SLIGHTLY ABOVE NORMAL TEMPS. THE NEXT LOW PRESSURE SYSTEM WAS STILL WELL OFFSHORE AND WILL NOT IMPACT THE AREA UNTIL TONIGHT. THE TREND IN THE MODELS WAS TOWARD A SLOWER ARRIVAL OF THE PRECIP SHIELD. RAIN IS NOT EXPECTED TO REACH THE COAST UNTIL SOMETIME THIS EVENING AND THE CASCADES UNTIL ABOUT MIDNIGHT. MUCH OF THE PRECIP WILL OCCUR WITH AND BEHIND THE COLD FRONT THAT WILL SWEEP ACROSS THE AREA OVERNIGHT. THE UPPER TROF WILL MOVE OVER THE PACIFIC NORTHWEST ON MON AND THEN LINGER OVER THE REGION THROUGH TUE FOR COOL AND UNSETTLED CONDITIONS. .LONG TERM FROM THE PREVIOUS DISCUSSION... A RIDGE OF HIGH PRES AT THE SURFACE AND ALOFT WILL GIVE A SUNNY DAY TO THE AREA ON WEDNESDAY WITH SOMEWHAT COOL TEMPERATURES IN THE MID 50S TO LOWER 60S. CLOUDS WILL BEGIN INCREASING WEDNESDAY NIGHT. THEN A SPLITTING AND WEAKENING FRONTAL SYSTEM WILL MOVE ACROSS THE AREA ON THURSDAY BRING CLOUDS...BUT RATHER A LOW CHANCE OF RAIN. MODEL CONSISTENCY AND CONTINUITY BREAKS DOWN SOMEWHAT TOWARD THE END OF NEXT WEEK. A DRY PERIOD IS POSSIBLE ON FRIDAY AND ANOTHER SYSTEM IS LIKELY NEXT WEEKEND...BUT CONFIDENCE IN TIMING IS LOW. NO CHANGES WERE MADE BEYOND THU. ALBRECHT && .AVIATION...A COLD FRONT NEAR 130W THIS MORNING WILL MOVE THROUGH WESTERN WASHINGTON TONIGHT. SW FLOW ALOFT. AIR MASS DRY AND STABLE EXCEPT PATCHES OF MORNING FOG. THERE IS SOME MARINE STRATUS OFFSHORE AND THE HRRR MODEL HAS THAT MOVING ON TO THE OREGON BEACHES MIDDAY AND SPREADING NORTH INTO GRAYS HARBOR AROUND 21Z. THOSE LOW CLOUDS SHOULD BE UP AND DOWN THE WA COAST BY LATE THIS AFTERNOON THEN SPREAD INLAND OVERNIGHT AS THE FRONT MOVES IN AND ONSHORE FLOW INCREASES. KSEA...SOUTHERLY FLOW WILL DEVELOP THIS AFTERNOON AND CLOUDS JUST AHEAD OF THE COLD FRONT WILL MOVE IN QUICKLY THIS EVENING. && .MARINE...SOUTHERLIES WILL PICK UP THROUGH THE DAY TODAY AS A COLD FRONT NEARS WESTERN WA. THE STRONG COLD FRONT WILL MOVE THROUGH THE WATERS TONIGHT WITH SMALL CRAFT ADVISORY WINDS SOUTHERLY WINDS TURNING TO WESTERLY IN THE STRAIT MONDAY AND PEAKING IN THE CENTRAL STRAIT MONDAY EVENING. THE ONSHORE FLOW WILL EASE TUESDAY WITH THE FLOW BECOMING LIGHT WEDNESDAY. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...NONE. PZ...SMALL CRAFT ADVISORY IN EFFECT FOR ALL WATERS EXCEPT THE CENTRAL STRAIT OF JUAN DE FUCA AND PUGET SOUND/HOOD CANAL. && $$ WWW.WEATHER.GOV/SEATTLE FOR THE GRAPHICAL AFD...VISIT WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1249 PM CDT SUN OCT 6 2013 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CDT SUN OCT 6 2013 FORECAST A BIT MORE QUIET THAN PREVIOUS DAYS WITH LOW IMPACT WEATHER THROUGH THE PERIOD. A BIT OF A CHALLENGE WITH THE LONGWAVE LOW SHIFTING ACROSS THE REGION AND THE WRAP AROUND MOISTURE COMING IN LATE TODAY AND OVERNIGHT. WATER VAPOR IMAGERY LOCATES THE CENTER OF THE 300-500MB CIRCULATION EAST OF KSUX IOWA WITH A SLOW DRIFT EAST. REGIONAL RADARS ARE INDICATING WRAP AROUND MOIST PLUME CONTINUING FROM KINL-KFAR-KABR- CENTRAL NEBRASKA WITH RAINFALL OF .03 TO .08 PER HOUR IN THE BAND. CLOUDS ARE LOW TOO...SO A WELL SATURATED ENVIRONMENT. PER RAP ANALYSIS...GOOD CORRELATION WITH THE 305-308 THETA-E SURFACE AND FLOW UP THE SURFACE WITHIN THE MOIST PLUME / TROWAL. ANOTHER DEFORMATION BAND CLOSER TO THE LOW CENTER ITSELF IS FOUND IN NW IA WITH A FEW HUNDREDTHS PER HOUR THERE. THESE ARE PLAYERS FOR THE OVERNIGHT FORECAST. AT 3 AM...DRY SLOT AND CLEAR SKIES RUNNING THROUGH MOST OF THE FORECAST AREA...BUT LOWER CLOUD NOW MOVING SLOWLY EAST TOWARD MISS RIVER IN NERN IA AND SERN MN. SOME PATCHY FOG MAY BE AROUND WITH LIGHT WIND IN THE CLEAR SECTOR THIS MORNING AS DEWPOINT DEPRESSIONS ARE NEAR ZERO. THE LOW WILL SHIFT EAST TODAY AND THE CONSENSUS MODEL SOLUTIONS TRACK IT THROUGH THE QUAD CITIES OR A BIT NORTH. THIS PLACES THE NORTHERN SIDE OF THE LOW OVER THE SOUTHERN FORECAST AREA. LOW- LEVEL LAPSE RATES ARE PRETTY STEEP BY LATER AFTERNOON /7.5-8.5 C PER KM/ AS THIS OCCURS AND WITH CIRCULATION CENTER SO CLOSE...THINKING SCT SHOWERS WILL DEVELOP ACROSS THE SOUTH THIS AFTERNOON. THIS ALSO COMBINES WITH LIFT UP THE THETA-E SURFACES IN THAT AREA AND A SPOKE OF SHORTWAVE TROUGH ENERGY WORKING NORTH AROUND THE LOW. THIS SCT SHOWERS AREA WILL EXTEND BACK TOWARD THE WEST WHERE MAIN MOIST PLUME WILL BE INCOMING. TONIGHT...GOOD CONSENSUS ON DRAGGING THE WRAP AROUND RAIN BAND THROUGH THE AREA. SOUNDINGS ACROSS THE MODELS ARE SATURATED...SOME VERY SATURATED FROM 0-3KM. FORCING REMAINS THAT TROWAL AIR STREAM WITH THETA-E SURFACE LIFT RISING AS THE PARCEL MOVE SOUTH. ALTHOUGH WEAKER FORCING THAN CURRENTLY OUT WEST...THE 06.00Z GFS HAS 7 UB/S OF LIFT FROM 0-3KM AT KLSE AT 06Z AND THE LAYER IS TOTALLY SATURATED. THUS...HAVE PUT IN SCATTERED SHOWERS OVERNIGHT TO ACCOUNT FOR THIS...BUT THINKING THAT OUR RAIN CHANCES MAY BE TOO LOW. DAY SHIFT MAY NEED TO BUMP THE RAIN CHANCES. THE LOW MOVES EAST MONDAY AND WITH IT THE RAIN CHANCES AND THE CLOUDS. VERY LITTLE CHANGE TO THE TEMPERATURES FOR THE FORECAST CYCLE - VERY NEAR TO PREVIOUS FORECAST. .LONG TERM...(MONDAY THROUGH SATURDAY) ISSUED AT 325 AM CDT SUN OCT 6 2013 PRETTY QUIET PERIOD OVERALL WITH LONGWAVE RIDGE BUILDING OVER THE MIDWEST AS THE LONGWAVE TROUGH DIGS INTO THE SOUTHWEST U.S. THE GFS ENSEMBLES ARE IN GOOD AGREEMENT ON THE 500MB PATTERN THROUGH ABOUT THURSDAY WHICH DEFINES THE DIGGING OF THE LONGWAVE TROUGH OUT WEST. THE ENSEMBLES AND THE DETERMINISTIC ECMWF 05.12Z/06.00Z AND 06.00Z GEM/GFS SOLUTIONS DIVERGE ON HOW THAT TROUGH ENERGY LIFTS NORTHEAST TOWARD THE GREAT LAKES AND DAKOTAS FOR NEXT WEEKEND. OVERALL IT WILL BE A VERY MILD WEEK WITH ABOVE NORMAL TEMPERATURES AND SOUTHERLY FLOW UNDER THE RIDGE. BY LATE NEXT WEEK...THUNDERSTORMS CHANCES MOVE INTO THE FORECAST AS THE TROUGH EJECTS NORTHEAST. OVERALL...THERE ARE TIMING DIFFERENCES AND PREFER THE SLIGHTLY MORE STABLE ECMWF FAMILY OF SOLUTIONS FOR SLOWER TIMING. BOTTOM LINE IS THUNDERSTORM CHANCES LATE WEEK AFTER A WARM SUNNY WEEK. NOT SURE THERE IS EVEN A FROST OR VALLEY FOG DAY IN THERE WITH THE CLEAR SKIES PREDICTED BECAUSE THE SOUTHERLY FLOW KICKS IN SO RAPIDLY. ONLY FROST TIME FRAME IS POSSIBLY TUESDAY MORNING IN CENTRAL WISCONSIN IF THE SOUTHERLY FLOW DOESNT KICK IN FAST ENOUGH. A CALM MONDAY EVENING AND RAPID COOL DOWN WOULD SEEM TO SUGGEST LOWS IN THE UPPER 30S....WITH LIGHT SOUTH WINDS KICKING && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1249 PM CDT SUN OCT 6 2013 MAIN CHALLENGE FOR THE FORECAST PERIOD ARE THE CEILINGS AS A BAND OF STRATUS WITH EMBEDDED RAIN SHOWERS MOVES ACROSS CENTRAL / SOUTHERN MINNESOTA INTO THE TAF SITES. THERE IS ABOVE AVERAGE CONFIDENCE IN A QUICK DROP FROM VFR TO LOW-END MVFR AS A SECONDARY SURFACE TROUGH PASSES THIS AFTERNOON...AND THE LIGHT RAIN SHOWERS BEGIN. CEILINGS ARE EXPECTED TO LOWER FURTHER TO LIFR AT KRST...AND POSSIBLY IFR AT KLSE...THROUGH THE EVENING HOURS DURING WHAT SHOULD BE THE PEAK OF THE SHOWER ACTIVITY. MODEL GUIDANCE IN DECENT AGREEMENT THAT PRECIPITATION SHOULD SUBSIDE/WEAKEN OR MOVE EAST OF THE TERMINALS DURING THE OVERNIGHT...WITH THE LOW STRATUS LINGERING A FEW HOURS MORE. AT THIS TIME...BACK EDGE OF CLOUD DECK SHOULD MAKE IT TO KRST BY 10-12Z AND KLSE A FEW HOURS LATER. VFR CONDITIONS ARE THEN EXPECTED FOR MUCH OF MONDAY AS SURFACE RIDGE OF HIGH PRESSURE BUILDS IN. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...BAUMGARDT LONG TERM....BAUMGARDT AVIATION.....ZT