Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/07/13
AREA FORECAST DISCUSSION
NWS ALBANY NY
641 AM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONTAL BOUNDARY OVER THE NEW YORK PENNSYLVANIA
BORDER...WILL KEEP CLOUDS ALONG WITH AN ISOLATED TO SCATTERED
THREAT OF SHOWERS FOR THE FIRST HALF OF THIS WEEKEND. AS THE
BOUNDARY MOVES NORTH OF THE CAPITAL REGION TONIGHT INTO
SUNDAY...MORE WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS WILL
INCREASE ACROSS THE REGION...ALONG WITH HIGHER HUMIDITY LEVELS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM EDT...A FEW LIGHT SHOWERS PER THE LATEST 88D SCANS WERE
TRACKING ACROSS THE DACKS WITH A MORE CONCENTRATED AREA OF
CONVECTION IN THE BUFFALO VICINITY. LATEST HRRR REFLECTIVITY
FORECASTS SUGGESTS THIS UPSTREAM BAND OF CONVECTION SHOULD WEAKEN AS
IT APPROACHES A MORE STABLE DOWNSTREAM AIR MASS. OTHERWISE...THE
FRONTAL BOUNDARY HAS MOVED LITTLE WITH THE BETTER PROGRESS ACROSS
SOUTHWEST NY STATE. NO OTHER CHANGES AT THIS TIME.
PREV DISC...
QUASI-STATIONARY BOUNDARY WAS SITUATED ALONG THE NY/PA BORDER.
REGIONAL RADAR MOSAIC REVEALS WIDELY SCATTERED SHOWERS ACROSS
CENTRAL AND WESTERN NY WITH MORE ROBUST CONVECTION ACROSS LOWER
MICHIGAN AND APPROACHING LOWER ONTARIO PROVENCE. H2O VAPOR LOOP
DOES HINT AT A WEAK SHORT WAVE EMBEDDED WITHIN THE WESTERLY FLOW
NORTH OF THIS FRONTAL BOUNDARY THAT IS THE LIKELY CULPRIT FOR THE
AFOREMENTIONED DEEPER CONVECTION UPSTREAM. LATEST HOURLY RUN OF
THE RUC13/HRRR AND 4KM SPC WRF MODELS SUGGEST THIS UPSTREAM SHOULD
WEAKEN AS IT OUTRUNS THE LOW LEVEL JET /AOA 20KTS/ AND ELEVATED
INSTABILITY. MEANWHILE...SURFACE HIGH SITUATED NORTH OF THE GREAT
LAKES REGION CONTINUES TO EXTEND ITS INFLUENCE EAST AND SOUTHWARD
WHICH WILL LIKELY KEEP THIS FRONTAL BOUNDARY FROM MOVING FURTHER
NORTH THROUGH THE DAY. WITH THAT SAID...WE REMAIN ON THE COOLER
SIDE OF THE BOUNDARY WITH CONSIDERABLE CLOUD COVER AND THE CHANCE
/SLIGHT-CHC FOR SOME SHOWER ACTIVITY. WE WILL SHADE ON THE COOLER
SIDE OF THE GUIDANCE...CLOSER TO THE MET MOS VALUES AND HOURLY
LAMP/LAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
00Z NCEP MODEL SUITE AND INTERNATIONAL GUIDANCE HAVE RESULTED IN A
LARGER SHIFT TOWARD A SLOWER MORE AMPLIFIED PATTERN. THE RESULT IS
A SLOWER TIMING OF THE WARM FRONTAL PASSAGE TO BE FOLLOWED BY THE
COLD FRONT LATE MONDAY OR MONDAY NIGHT.
TONIGHT...THE LOW LEVEL JET UPSTREAM WILL INCREASE IN EARNEST AS
PRECIPITATION/CONVECTION UNFOLD. THE BEST WARM ADVECTION AND
ISENTROPIC LIFT IS EXPECTED TO OCCUR OVER WESTERN AND CENTRAL NY.
PER THE CORFIDI VECTORS AND THICKNESS...THIS ACTIVITY WILL LIKELY
SPREAD INTO THE WESTERN ZONES AND THE DACKS THROUGH THE OVERNIGHT
AND GRADUALLY SPREAD ACROSS THE REMAINDER OF THE CWA. WE WILL
GRADUALLY INCREASE POPS FROM WEST TO EAST AND KEEP TEMPERATURES A
BIT STEADY AS THE WARMER AIR BEGINS TO ADVECT NORTHWARD.
THROUGH SUNDAY...THE PROGRESS OF THIS WARM FRONT WILL BE
INTERESTING TO WATCH AS THE SURFACE HIGH /1024MB/ NORTH OF THE
GREAT LAKES MIGRATES ACROSS NORTHERN NEW ENGLAND AND KEEPING THE
LOWER LEVEL AGEOSTROPHIC FLOW ACROSS THE HUDSON RIVER VALLEY AND
POINTS EAST. ONCE AGAIN CONSIDERABLE CLOUD COVER ALONG WITH
SHOWERS AS WE WILL FAVOR A MOS BLEND OF THE NAM/GFS.
SUNDAY NIGHT...TRENDS ARE FAVORING FOR A MID LEVEL DRY SLOT TO
ADVECT INTO THE REGION WHICH SHOULD REDUCE COVERAGE OF PRECIP BUT
KEEP THE LOW LEVEL MOISTURE IN PLACE. IN FACT...CROSS SECTIONS
REVEAL AMPLE WIND SHEAR AT OR JUST ABOVE THE LOW LEVEL MOISTURE
THAT POCKETS OF DRIZZLE MAY DEVELOP. TEMPERATURES SHOULD BE A
LITTLE MILDER.
MONDAY...A FAIRLY DEEP UPR LOW ACROSS THE MID WEST AND ITS
ASSOCIATED SURFACE LOW/COLD FRONT ARE EXPECTED TO SLOW THE FORWARD
PROGRESSION OF THIS SYSTEM. THIS WILL LIKELY PLACE OUR REGION WELL
WITHIN THE WARM SECTOR...HOWEVER...MARINE INFLUENCE COMPONENT
REMAINS TO BE SEEN AS THE LOW LEVEL JET WILL BE INCREASING FROM
THE SSW. FOR NOW WE WILL FAVOR A BLENDED APPROACH TO THE MAV/MET
MOS. AS FOR PRECIP CHANCES...WE WILL REDUCE THE POPS FROM THE
PREVIOUS FORECAST DUE TO THE SLOWER ARRIVAL TIME BUT STILL KEEP
THE MENTION OF THUNDER.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A DYNAMIC STORM SYSTEM WILL BE APPROACHING AT THE START OF THE
EXTENDED PERIOD. A LARGE CLOSED LOW WILL BE MOVING ACROSS THE OHIO
VALLEY/EASTERN GREAT LAKES WITH A STRONG COLD FRONT AT THE SURFACE.
AHEAD OF THIS BOUNDARY...A STRONG SOUTHERLY LOW LEVEL JET WILL
TRANSPORT PLENTY OF MOISTURE /SOME OF WHICH WAS ASSOCIATED WITH THE
REMAINS OF TC KAREN...WHICH WILL ALREADY HAVE BEEN ABSORBED INTO THE
FRONTAL ZONE ACROSS THE SOUTHEAST/ TOWARDS THE REGION. THE 00Z GEFS
SHOWS PWAT VALUES 2-3 STD ABOVE NORMAL ACROSS THE REGION FOR MON
NIGHT INTO TUESDAY.
THE MODELS CONTINUE TO SHOW PLENTY OF DISAGREEMENT WITH THE TIMING
OF THIS FRONT. THE ECMWF DOESN/T CLOSE THE UPPER LOW OFF...AND A
RESULT...IS MUCH QUICKER WITH THE BOUNDARY. WE WILL FAVOR THE SLOWER
00Z GFS SOLUTION...WHICH IS ALSO BETTER IN LINE WITH THE 00Z GGEM
AND 00Z GEFS. AS A RESULT...MONDAY NIGHT MAY START OFF VERY MILD
AND MUGGY WITH TEMPS IN THE 60S AND ONLY SCT RAIN SHOWERS...AND
STEADY PRECIP MAY NOT ARRIVE UNTIL VERY LATE AT NIGHT OR UNTIL
DURING THE DAY TUESDAY. TEMPS WILL STILL BE MILD ON TUESDAY...WITH
UPPER 60S TO LOW 70S ACROSS THE REGION.
A LINE OF SHOWERS ALONG/JUST AHEAD OF THE FRONT LOOK TO MOVE THROUGH
SOMETIME ON TUESDAY. THE RAIN MAY BRIEFLY FALL HEAVY AT TIMES. WE
WILL INCLUDE A SLIGHT CHC FOR THUNDER...BUT MEAGER INSTABILITY
LEVELS SHOULD KEEP THUNDER FROM BEING MORE WIDESPREAD. MOST AREAS
WILL SEE AROUND AN INCH OF RAINFALL...WHICH IS ACTUALLY NEEDED DUE
TO THE RECENT DRY STRETCH. FLOODING ISSUES OUTSIDE LOW
LYING/URBAN/POOR DRAINAGE AREAS AREN/T ANTICIPATED DUE TO THE DRY
ANTECEDENT CONDITIONS AND HIGH FFG.
BEHIND THE FRONT...STEADY RAIN WILL MOVE OFF TO THE EAST AND
END...AND TEMPS AND HUMIDITY LEVELS WILL START TO FALL OFF. THE
THREAT FOR PRECIP WON/T BE ENTIRELY GONE...AS THE UPPER LOW LOOKS TO
PASS OVER THE REGION...SO THE THREAT FOR RAIN SHOWERS WILL CONTINUE
FOR WED/THURS...MAINLY ACROSS THE HIGH TERRAIN AND NORTHERN AREAS.
TEMPS WILL BE COOLER FOR TUES NIGHT BEHIND THE FRONT WITH 40S AND
50S. DAYTIME TEMPS ON WED/THURS WILL BE A BIT COOLER THAN RECENT
DAYS...BUT STILL ABOVE NORMAL...WITH MID 60S FOR VALLEY AREAS.
OVERNIGHT LOWS WED AND THURS NIGHTS WILL MAINLY BE IN THE 40S.
ONCE THE UPPER LOW EXITS...A STRONG RIDGE WILL ESTABLISH ITSELF
ALONG THE EASTERN SEABOARD...ALLOWING FOR EVEN MILDER AIR TO RETURN
TO THE REGION. AN EXTENDED PERIOD OF DRY WEATHER LOOKS TO BE IN
PLACE FROM THURSDAY NIGHT INTO MUCH OF THE WEEKEND...WITH ABOVE
NORMAL WARMTH. DAYTIME TEMPS MAY RETURN TO NEAR 70 FOR
FRI/SAT...WHICH IS ABOUT 10 DEGREES ABOVE NORMAL FOR MID OCT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
FLYING CONDITIONS LOOK TO STAY MVFR FOR KALB/KGFL FOR MUCH OF THE
MORNING WITH LOTS OF LINGERING LOW CLOUDS AS A STALLED OUT FRONTAL
BOUNDARY WILL CONTINUE TO BE DRAPED OVER THE REGION. KPOU/KPSF MAY
CONTINUE TO SEE A FEW MORE HOURS OF IFR CIGS BEFORE CIGS RISE TO
MVFR CONDITIONS BY MID TO LATE MORNING. THERE MAY BE A BRIEF PERIOD
OF IMPROVEMENT DURING AFTERNOON WITH VFR CONDITIONS POSSIBLE AT
KGFL/KALB/KPOU. SOME SCT RAIN SHOWERS MAY AFFECT THE REGION WITH
LIGHT AND VARIABLE SFC WINDS DURING THE AFTN HOURS AS WELL.
ALL SITES LOOK TO BE BACK IN MVFR CONDITIONS FOR LOW CIGS BY THIS
EVENING WITH CALM WINDS AND POSSIBLE RAIN SHOWERS AS THE SLOW MOVING
FRONTAL BOUNDARY REMAINS NEARLY STATIONARY OVER THE AREA. IFR
CONDITIONS FOR LOW CIGS MAY BE POSSIBLE LATE TONIGHT AS WELL...BUT
CONFIDENCE IN THIS IS NOT HIGH ENOUGH TO INCLUDE IN THE TAFS AT THIS
TIME.
OUTLOOK...
SUNDAY NIGHT-MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
MONDAY NIGHT-TUESDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
LOW LEVEL MOISTURE WILL REMAIN RATHER HIGH ALONG WITH THE INCREASE
THREAT FOR MORE SHOWERS. WINDS WILL BE RATHER LIGHT WITH A
TENDENCY FROM THE NORTHERLY DIRECTION THROUGH TONIGHT AT SPEEDS
LESS THAN 10 MPH. FIRE WEATHER CONCERNS WILL BE AT A MINIMUM.
&&
.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.
RAINFALL FORECASTS WILL RANGE FROM ONE QUARTER TO ONE HALF OF AN
INCH BASIN AVERAGE NORTH AND WEST OF THE CAPITAL DISTRICT WITH ONE
TENTH TO ONE QUARTER OF AN INCH FROM THE CAPITAL DISTRICT TO
POINTS EAST AND SOUTH. THESE VALUES WILL BE SLIGHTLY HIGHER ACROSS
THE HIGHER TERRAIN BUT LIKELY HAVE LITTLE IMPACT TO THE RIVERS
WITH SLIGHT RISES EXPECTED.
MAIN CHALLENGE WILL BE THE INCREASING MOISTURE PROFILES HEADING
INTO MONDAY. MOISTURE FROM WHAT IS LEFT OF TS KAREN MAY BECOME
ABSORBED WITHIN THE FRONTAL SYSTEM AS IT APPROACHES LATE MONDAY.
RAINFALL AMOUNTS UP TO AND OVER ONE INCH ARE POSSIBLE. WITHIN BANK
RIVER RISES ARE EXPECTED WITH POSSIBLE ISSUES FROM FALLEN LEAFS
BLOCKING STORM DRAINS TO RESULT IN PONDING WATER. PLEASE REFER TO
THE LATEST TROPICAL GUIDANCE FROM THE NATIONAL HURRICANE CENTER.
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/WASULA
HYDROLOGY...BGM/WASULA
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
519 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 22Z...
* SSE WINDS SLOWLY BECOMING SOUTHWEST BY LATE THIS EVENING.
* SCT -SHRA/-TSRA REMAINS POSSIBLE AROUND THE TERMINALS THROUGH
00Z...WITH MVFR CEILINGS IN THIS -TSRA.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
VERY MESSY FORECAST FOR THIS AFTERNOON. THE SURFACE LOW IS OVER SE
SOUTH DAKOTA...ITS WARM FRONT IS OVER SOUTHERN WISCONSIN...AND ITS
COLD FRONT IS OVER EASTERN IOWA. STRATUS IS STILL HOLDING STRONG
ACROSS THE REGION...BUT LOOKING OUT THE WINDOW HERE...A FEW HOLES
ARE BEGINNING TO FORM. EXPECTING CIGS TO LIFT TO HIGH END MVFR BY
19Z.
WHILE THE LOW CIGS HAVE CAUSED HAVOC WITH BREAK AWAY POINTS...IT IS
LIMITING OUR MIXING AND HAVE LOWERED WIND GUSTS TO 15KT. THERE IS A
CHANCE WE MAY NOT SEE ANY WIND GUSTS AT ALL THIS AFTN. IN
ADDITION...INSTABILITY IS MUCH LOWER THAN INITIALLY THOUGHT DUE TO
THE STRATUS. THEREFORE MADE SOME CHANGES TO TS CHANCES THIS AFTN.
FIRST AT RFD...THINKING THE TSRA PASSING OVER THE TERMINAL NOW WILL
BE THE MAIN SHOW. EXPECTING JUST SHOWERS AFT 20Z...AND THEN DRY
CONDITIONS AFT 22Z. FOR THE EASTERN TERMINALS...TIMING OF THE
CURRENT AREA OF SCT TS HAS THEM ARRIVING AT 19Z. WIDER COVERAGE IS
EXPECTED BTWN 20Z AND 23Z. SOME OF THE STORMS MAY PULSE UP AND
BECOME STRONG TO SEVERE...BUT WIDESPREAD SEVERE WEATHER IS NO LONGER
EXPECTED.
THE SOUPY ENVIRONMENT OUTSIDE WILL RESULT IN REDUCED VSBYS IF ANY
STRONG SHOWERS OR TSRA PASS OVERHEAD. OBSERVED VSBYS RANGE FROM
2.5SM TO 5SM SO KEPT 3SM GOING. ADDITIONAL SHOWERS ARE EXPECTED
BEHIND THE TSRA FOR A FEW HOURS...THROUGH 03Z. WINDS WILL BECOME SW
TONIGHT ARND 8KT. DESPITE THE DRIER AIR MOVING INTO THE REGION
BEHIND THE COLD FRONT...KEPT MVFR CIGS IN THE TAFS AFT 00Z. ON
SATELLITE THERE IS A REGION OF MVFR CIGS JUST ALONG AND BEHIND THE
FRONT. GUIDANCE INDICATES THAT THE MOISTURE WILL LINGER BEHIND THE
FRONT WITH MVFR CIGS HOLDING ON. WITH NO GOOD REASON TO PULL THE
CIGS...DECIDED TO LEAVE THEM IN.
EXPECTING THE LOWER CIGS TO BURN OFF SUNDAY MORNING WITH SW WINDS
10-15KT. THERE WILL BE A WINDOW OF SCT TO CLEAR SKIES ASSOCIATED
WITH THE LOWS DRY SLOT MOVING OVER THE TERMINALS TOMORROW WITH
ANOTHER ROUND OF MVFR-VFR CIGS BEHIND IT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED/DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH -SHRA/-TSRA TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PSBL MVFR CIGS AND CHC SHRA.
MONDAY...MVFR CIGS/VSBYS WITH SHRA. PSBL POCKETS OF IFR CIGS.
TUESDAY THROUGH FRIDAY...VFR.
BEACHLER
&&
.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:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
458 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 20Z...
* SOUTH WINDS ARND 10 KT. GUSTS ARND 15KT THIS AFTN AT MDW.
* SCATTERED THUNDERSTORMS EXPECTED THRU 23Z. SOME MAY BE STRONG TO
SEVERE.
* MODERATE RAIN THAT MAY CAUSE 6SM VSBY 00Z-03Z.
* WINDS BECOME SW AFTER THE FRONT ALONG WITH MVFR CIGS IMPROVING
TO VFR MID SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
VERY MESSY FORECAST FOR THIS AFTERNOON. THE SURFACE LOW IS OVER SE
SOUTH DAKOTA...ITS WARM FRONT IS OVER SOUTHERN WISCONSIN...AND ITS
COLD FRONT IS OVER EASTERN IOWA. STRATUS IS STILL HOLDING STRONG
ACROSS THE REGION...BUT LOOKING OUT THE WINDOW HERE...A FEW HOLES
ARE BEGINNING TO FORM. EXPECTING CIGS TO LIFT TO HIGH END MVFR BY
19Z.
WHILE THE LOW CIGS HAVE CAUSED HAVOC WITH BREAK AWAY POINTS...IT IS
LIMITING OUR MIXING AND HAVE LOWERED WIND GUSTS TO 15KT. THERE IS A
CHANCE WE MAY NOT SEE ANY WIND GUSTS AT ALL THIS AFTN. IN
ADDITION...INSTABILITY IS MUCH LOWER THAN INITIALLY THOUGHT DUE TO
THE STRATUS. THEREFORE MADE SOME CHANGES TO TS CHANCES THIS AFTN.
FIRST AT RFD...THINKING THE TSRA PASSING OVER THE TERMINAL NOW WILL
BE THE MAIN SHOW. EXPECTING JUST SHOWERS AFT 20Z...AND THEN DRY
CONDITIONS AFT 22Z. FOR THE EASTERN TERMINALS...TIMING OF THE
CURRENT AREA OF SCT TS HAS THEM ARRIVING AT 19Z. WIDER COVERAGE IS
EXPECTED BTWN 20Z AND 23Z. SOME OF THE STORMS MAY PULSE UP AND
BECOME STRONG TO SEVERE...BUT WIDESPREAD SEVERE WEATHER IS NO LONGER
EXPECTED.
THE SOUPY ENVIRONMENT OUTSIDE WILL RESULT IN REDUCED VSBYS IF ANY
STRONG SHOWERS OR TSRA PASS OVERHEAD. OBSERVED VSBYS RANGE FROM
2.5SM TO 5SM SO KEPT 3SM GOING. ADDITIONAL SHOWERS ARE EXPECTED
BEHIND THE TSRA FOR A FEW HOURS...THROUGH 03Z. WINDS WILL BECOME SW
TONIGHT ARND 8KT. DESPITE THE DRIER AIR MOVING INTO THE REGION
BEHIND THE COLD FRONT...KEPT MVFR CIGS IN THE TAFS AFT 00Z. ON
SATELLITE THERE IS A REGION OF MVFR CIGS JUST ALONG AND BEHIND THE
FRONT. GUIDANCE INDICATES THAT THE MOISTURE WILL LINGER BEHIND THE
FRONT WITH MVFR CIGS HOLDING ON. WITH NO GOOD REASON TO PULL THE
CIGS...DECIDED TO LEAVE THEM IN.
EXPECTING THE LOWER CIGS TO BURN OFF SUNDAY MORNING WITH SW WINDS
10-15KT. THERE WILL BE A WINDOW OF SCT TO CLEAR SKIES ASSOCIATED
WITH THE LOWS DRY SLOT MOVING OVER THE TERMINALS TOMORROW WITH
ANOTHER ROUND OF MVFR-VFR CIGS BEHIND IT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN THUNDERSTORM FORECAST.
* MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS THIS EVENING AND OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PSBL MVFR CIGS AND CHC SHRA.
MONDAY...MVFR CIGS/VSBYS WITH SHRA. PSBL POCKETS OF IFR CIGS.
TUESDAY THROUGH FRIDAY...VFR.
BEACHLER
&&
.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
247 PM CDT SAT OCT 5 2013
.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 20Z...
* SOUTH WINDS ARND 10 KT. GUSTS ARND 15KT THIS AFTN AT MDW.
* SCATTERED THUNDERSTORMS EXPECTED THRU 23Z. SOME MAY BE STRONG TO
SEVERE.
* MODERATE RAIN THAT MAY CAUSE 6SM VSBY 00Z-03Z.
* WINDS BECOME SW AFTER THE FRONT ALONG WITH MVFR CIGS IMPROVING
TO VFR MID SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
VERY MESSY FORECAST FOR THIS AFTERNOON. THE SURFACE LOW IS OVER SE
SOUTH DAKOTA...ITS WARM FRONT IS OVER SOUTHERN WISCONSIN...AND ITS
COLD FRONT IS OVER EASTERN IOWA. STRATUS IS STILL HOLDING STRONG
ACROSS THE REGION...BUT LOOKING OUT THE WINDOW HERE...A FEW HOLES
ARE BEGINNING TO FORM. EXPECTING CIGS TO LIFT TO HIGH END MVFR BY
19Z.
WHILE THE LOW CIGS HAVE CAUSED HAVOC WITH BREAK AWAY POINTS...IT IS
LIMITING OUR MIXING AND HAVE LOWERED WIND GUSTS TO 15KT. THERE IS A
CHANCE WE MAY NOT SEE ANY WIND GUSTS AT ALL THIS AFTN. IN
ADDITION...INSTABILITY IS MUCH LOWER THAN INITIALLY THOUGHT DUE TO
THE STRATUS. THEREFORE MADE SOME CHANGES TO TS CHANCES THIS AFTN.
FIRST AT RFD...THINKING THE TSRA PASSING OVER THE TERMINAL NOW WILL
BE THE MAIN SHOW. EXPECTING JUST SHOWERS AFT 20Z...AND THEN DRY
CONDITIONS AFT 22Z. FOR THE EASTERN TERMINALS...TIMING OF THE
CURRENT AREA OF SCT TS HAS THEM ARRIVING AT 19Z. WIDER COVERAGE IS
EXPECTED BTWN 20Z AND 23Z. SOME OF THE STORMS MAY PULSE UP AND
BECOME STRONG TO SEVERE...BUT WIDESPREAD SEVERE WEATHER IS NO LONGER
EXPECTED.
THE SOUPY ENVIRONMENT OUTSIDE WILL RESULT IN REDUCED VSBYS IF ANY
STRONG SHOWERS OR TSRA PASS OVERHEAD. OBSERVED VSBYS RANGE FROM
2.5SM TO 5SM SO KEPT 3SM GOING. ADDITIONAL SHOWERS ARE EXPECTED
BEHIND THE TSRA FOR A FEW HOURS...THROUGH 03Z. WINDS WILL BECOME SW
TONIGHT ARND 8KT. DESPITE THE DRIER AIR MOVING INTO THE REGION
BEHIND THE COLD FRONT...KEPT MVFR CIGS IN THE TAFS AFT 00Z. ON
SATELLITE THERE IS A REGION OF MVFR CIGS JUST ALONG AND BEHIND THE
FRONT. GUIDANCE INDICATES THAT THE MOISTURE WILL LINGER BEHIND THE
FRONT WITH MVFR CIGS HOLDING ON. WITH NO GOOD REASON TO PULL THE
CIGS...DECIDED TO LEAVE THEM IN.
EXPECTING THE LOWER CIGS TO BURN OFF SUNDAY MORNING WITH SW WINDS
10-15KT. THERE WILL BE A WINDOW OF SCT TO CLEAR SKIES ASSOCIATED
WITH THE LOWS DRY SLOT MOVING OVER THE TERMINALS TOMORROW WITH
ANOTHER ROUND OF MVFR-VFR CIGS BEHIND IT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN THUNDERSTORM FORECAST.
* MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS THIS EVENING AND OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PSBL MVFR CIGS AND CHC SHRA.
MONDAY...MVFR CIGS/VSBYS WITH SHRA. PSBL POCKETS OF IFR CIGS.
TUESDAY THROUGH FRIDAY...VFR.
BEACHLER
&&
.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.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
216 PM CDT SAT OCT 5 2013
.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 18Z...
* SOUTH WINDS ARND 10 KT WITH GUSTS ARND 15KT THIS AFTN.
* SCATTERED THUNDERSTORMS EXPECTED AFT 19Z WITH MORE WIDESPREAD
STORMS EXPECTED 20Z-23Z. SOME MAY BE STRONG TO SEVERE.
* MODERATE RAIN THAT MAY CAUSE 6SM VSBY 00Z-03Z.
* WINDS BECOME SW AFTER THE FRONT ALONG WITH MVFR CIGS IMPROVING
TO VFR MID SUNDAY MORNING.
JEE
//DISCUSSION...UPDATED 18Z...
VERY MESSY FORECAST FOR THIS AFTERNOON. THE SURFACE LOW IS OVER SE
SOUTH DAKOTA...ITS WARM FRONT IS OVER SOUTHERN WISCONSIN...AND ITS
COLD FRONT IS OVER EASTERN IOWA. STRATUS IS STILL HOLDING STRONG
ACROSS THE REGION...BUT LOOKING OUT THE WINDOW HERE...A FEW HOLES
ARE BEGINNING TO FORM. EXPECTING CIGS TO LIFT TO HIGH END MVFR BY
19Z.
WHILE THE LOW CIGS HAVE CAUSED HAVOC WITH BREAK AWAY POINTS...IT IS
LIMITING OUR MIXING AND HAVE LOWERED WIND GUSTS TO 15KT. THERE IS A
CHANCE WE MAY NOT SEE ANY WIND GUSTS AT ALL THIS AFTN. IN
ADDITION...INSTABILITY IS MUCH LOWER THAN INITIALLY THOUGHT DUE TO
THE STRATUS. THEREFORE MADE SOME CHANGES TO TS CHANCES THIS AFTN.
FIRST AT RFD...THINKING THE TSRA PASSING OVER THE TERMINAL NOW WILL
BE THE MAIN SHOW. EXPECTING JUST SHOWERS AFT 20Z...AND THEN DRY
CONDITIONS AFT 22Z. FOR THE EASTERN TERMINALS...TIMING OF THE
CURRENT AREA OF SCT TS HAS THEM ARRIVING AT 19Z. WIDER COVERAGE IS
EXPECTED BTWN 20Z AND 23Z. SOME OF THE STORMS MAY PULSE UP AND
BECOME STRONG TO SEVERE...BUT WIDESPREAD SEVERE WEATHER IS NO LONGER
EXPECTED.
THE SOUPY ENVIRONMENT OUTSIDE WILL RESULT IN REDUCED VSBYS IF ANY
STRONG SHOWERS OR TSRA PASS OVERHEAD. OBSERVED VSBYS RANGE FROM
2.5SM TO 5SM SO KEPT 3SM GOING. ADDITIONAL SHOWERS ARE EXPECTED
BEHIND THE TSRA FOR A FEW HOURS...THROUGH 03Z. WINDS WILL BECOME SW
TONIGHT ARND 8KT. DESPITE THE DRIER AIR MOVING INTO THE REGION
BEHIND THE COLD FRONT...KEPT MVFR CIGS IN THE TAFS AFT 00Z. ON
SATELLITE THERE IS A REGION OF MVFR CIGS JUST ALONG AND BEHIND THE
FRONT. GUIDANCE INDICATES THAT THE MOISTURE WILL LINGER BEHIND THE
FRONT WITH MVFR CIGS HOLDING ON. WITH NO GOOD REASON TO PULL THE
CIGS...DECIDED TO LEAVE THEM IN.
EXPECTING THE LOWER CIGS TO BURN OFF SUNDAY MORNING WITH SW WINDS
10-15KT. THERE WILL BE A WINDOW OF SCT TO CLEAR SKIES ASSOCIATED
WITH THE LOWS DRY SLOT MOVING OVER THE TERMINALS TOMORROW WITH
ANOTHER ROUND OF MVFR-VFR CIGS BEHIND IT.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN THUNDERSTORM TRENDS...MEDIUM-HIGH CONFIDENCE
IN TIMING.
* MEDIUM-LOW CONFIDENCE IN CIG HEIGHTS THIS EVENING AND OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PSBL MVFR CIGS AND CHC SHRA.
MONDAY...MVFR CIGS/VSBYS WITH SHRA. PSBL POCKETS OF IFR CIGS.
TUESDAY THROUGH FRIDAY...VFR.
BEACHLER
&&
.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.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
322 AM CDT SAT OCT 5 2013
.DISCUSSION...
322 AM...PRIMARY FORECAST CONCERN/CHALLENGE IS POTENTIAL FOR
SEVERE WEATHER INTO THIS EVENING.
FRONTAL BOUNDARY HAS BEEN SLOWLY LIFTING NORTH ACROSS NORTHERN IL
WITH SOUTHERLY WINDS REACHING A RFD/ORD LINE. WHILE VISIBILITIES
HAVE REMAINED GENERALLY IN THE 1-3SM RANGE NEAR THE FRONT...ACROSS
FAR NORTHEAST IL SATELLITE IMAGERY SUGGESTS FOG IS RATHER THICK
OVER NORTHERN SECTIONS OF LAKE AND MCHENRY COUNTIES WITH UGN
REPORTING 1/4SM FOR THE PAST FEW HRS. WHILE THIS WILL LIKELY BE
SHORT-LIVED...OPTED TO ISSUE A DENSE FOG ADVISORY FOR THESE TWO
COUNTIES THROUGH 8AM. AS WINDS TURN SOUTHERLY...VISIBILITIES WILL
IMPROVE.
SOUTH OF THE FRONT...FAIRLY IMPRESSIVE AIRMASS THIS FAR NORTH FOR
EARLY OCTOBER WITH DEWPOINTS IN THE UPPER 60S AND MOISTURE IS
EXPECTED TO POOL THIS MORNING WITH PERHAPS LOWER 70 DEWPOINTS
ACROSS MUCH OF THE AREA. UPSTREAM CLOUD COVER IS MOSTLY MID/HIGH
CLOUDS THAT WILL LIKELY THIN THROUGH MID MORNING...SO APPEARS MUCH
OF THIS MORNING WILL BE MOSTLY SUNNY/PARTLY CLOUDY. THIS SHOULD
AID TEMPERATURES RISING INTO THE LOWER 80S ACROSS THE SOUTHEAST
HALF OF THE AREA AND WITH SUCH A MOIST AIRMASS IN PLACE...ONCE
HEATING BEGINS...POSSIBLE FOR ISOLATED THUNDERSTORMS THIS MORNING.
BULK OF THE ACTIVITY HOWEVER APPEARS TO HOLD OFF UNTIL THIS
AFTERNOON...BOTH FROM INCREASING DIURNALLY DRIVEN STORMS BUT ALSO
AS A SHORTWAVE LIFTS NORTHEAST ACROSS NORTH CENTRAL ILLINOIS THIS
AFTERNOON INTO THIS EVENING...AHEAD OF THE APPROACHING COLD FRONT.
WITH THUNDERSTORMS SPREADING EAST THIS EVENING BUT SLOWING.
OVERALL CONFIDENCE REGARDING THIS SCENARIO IS SOMEWHAT LOW IN
ADDITION TO THE POTENTIAL FOR SEVERE WEATHER. THE MAIN SEVERE
WEATHER THREAT WILL BE DAMAGING WINDS GUSTS BUT LACK OF STRONG
SHEAR ALOFT WOULD SUGGEST THESE WOULD BE MORE ISOLATED...RATHER
THEN A LINE OF STRONG/SEVERE STORMS. IN ADDITION...THE VERY MOIST
LOW LEVELS WILL YIELD LOW LCL HEIGHTS AND MODELS ARE IN FAIR
AGREEMENT WITH SURFACE WINDS BACKING SOME THIS AFTERNOON. THUS
INDIVIDUAL CELLS THAT FORM AWAY FROM CLUSTERS OR LINES OF
CONVECTION WILL HAVE SOME POTENTIAL TO PRODUCE A TORNADO.
FORECAST PRECIPITABLE WATER VALUES OF 1.5 INCHES OR HIGHER WILL
LEAD TO LOCALLY VERY HEAVY RAIN AND WITH LITTLE CHANGE TO STORM
MOTION...GENERALLY SOUTHWEST TO NORTHEAST...ANY TRAINING OF STORMS
COULD EASILY CAUSE FLOODING CONCERNS.
ACTIVITY WILL SLOWLY SHIFT EAST LATE TONIGHT INTO SUNDAY MORNING
AND HAVE INCLUDED CHANCE POPS EAST OF I-57 INTO THE MORNING.
UNCERTAINTY HAS INCREASED WITH THE ARRIVAL OF THE 00Z ECMWF WHICH
IS CONSIDERABLY FASTER THAN OTHER 00Z GUIDANCE WITH THE
PROGRESSION OF THE UPPER LOW EAST ACROSS THE LAKES REGION. SUNDAY
WAS SHAPING UP TO BE MAINLY DRY WITH PERHAPS SOME INSTABILITY
SHOWERS ARRIVING IN THE WEST BY EVENING. AND WITH THE POSSIBILITY
OF SOME SUNSHINE...TEMPS PERHAPS IN THE 60S AND WHILE THAT WILL BE
MUCH COLDER THAN TODAY...IT WOULD ONLY BE A FEW DEGREES BELOW
NORMAL. A FASTER SHIFT EAST OF THE UPPER LOW WILL ALSO END THE
SHOWER POTENTIAL MONDAY OR MONDAY EVENING...RATHER THAN TUESDAY
MORNING WITH THE SLOWER SOLUTIONS. CHANGES TO THE SUNDAY-TUESDAY
TIME PERIOD CAN BE EXPECTED DEPENDING ON THE SPEED OF THE UPPER
LOW. HOWEVER...THE WARMING TREND STILL LOOKS ON TRACK...PERHAPS
JUST DELAYED BY A DAY OR SO WITH HIGHS BACK INTO THE 70S BY
WEDNESDAY AND THURSDAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LOWERING VISIBILITY AND CIGS INTO IFR CATEGORY INTO OVERNIGHT.
* NORTHEAST WINDS BECOMING EAST THEN SOUTHEAST TONIGHT WITH SPEEDS
MOST OF TIME BELOW 10 KT.
* SMALL CHANCE OF TSRA SAT MORNING GRADUALLY INCREASING INTO MID-
AFTERNOON.
* THUNDERSTORMS LIKELY 22Z-00Z SOME OF WHICH COULD BE STRONG.
BEACHLER
//DISCUSSION...UPDATED 06Z...
VERY CHALLENGEING AVIATION CONDITIONS ARE IN STORE FOR THE NEXT 24
HOURS ACROSS THE REGION...ESPECIALLY OVER NORTHERN IL/NORTHWEST
IN. A STALLED FRONTAL BOUNDARY WAS ORIENTED ACROSS NORTHERN
IL...WHICH HAS RESULTED IN LIGHT WINDS TO AT TIMES CALM FOR
DPA/ORD/MDW/GYY. IN ADDITION VERY MOIST AIR WAS OVER THESE
AIRFIELDS AND HAS RESULTED IN VSBYS BEING REDUCED. IT APPEARS ORD
SHOULD ONLY REDUCE TO ARND 3-4SM OVERNIGHT...HOWEVER ELSEWHERE
MDW/GYY/DPA/RFD WILL LIKELY SEE VSBYS DOWN BTWN 1/2SM AT RFD/DPA
TO 2-3SM AT GYY/MDW. IR IMAGERY INDICATED SOME IFR CIGS WERE
DEVELOPING OVER FAR NORTHWEST IL WHICH HAS BROUGHT CIGS DOWN AT
RFD...AND IT IS POSSIBLE CIGS COULD DROP TO ARND 200-300FT AGL
BEFORE DAYBREKA THEN SLOWLY IMPROVE AFT DAYBREAK.
THEN THE FOCUS TURNS TOWARDS CONVECTIVE TIMING/PLACEMENT LATER
TODAY. AFTER SUNRISE VSBYS SHUD BE SLOW TO IMPROVE WITH JUST A
CIRRUS SHIELD EXPECTED OVERHEAD TO START THE DAY. THE COLD FRONT
WILL BE WELL WEST OF THE REGION...HOWEVER STEADILY PIVOTING EAST
TOWARDS NORTHERN IL AIRFIELDS. GUIDANCE CONTINUES TO INDICATE
WINDS BY MID MORNING WILL BECOME SOUTHERLY ARND 10KT AND
OCCASIONAL GUSTS TO THE MID-TEENS ARE LIKELY. CLOUDS WILL THICKEN
BY MIDDAY WITH A DECK ARND 3-4KFT AGL. WITH CONSIDERABLE ELEMENTS
SUGGESTING CONVECTION WILL BE FIRING ARND 18-19Z...IT IS LIKELY
THAT THE BEST CHC FOR CONVECTION WILL BE ARND 19Z-00Z...AND THE
BETTER COVERAGE WILL FALL WITHIN A 22-00Z TIMEFRAME. WINDS WILL
SLOWLY TURN TO THE 240-260 DEG RANGE FRONTAL PASSAGE...WITH
RAIN/THUNDER SLOWLY ENDING AFT 03-06Z SUN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN STABLE/SLIGHTLY LOWERING TREND OF
CIG...MEDIUM CONFIDENCE ON VISIBILITY. MEDIUM CONFIDENCE ON HOW
LOW CIG AND VISIBILITY WILL FALL.
* MEDIUM-HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE ON TSRA TIMING OF 21Z-02Z.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR DURING THE DAY WITH MVFR CIGS AND CHC SHRA DURING THE
NIGHT.
MONDAY...CHC OF MVFR AND SLT CHC OF SHRA DURING THE MORNING.
TUESDAY-THURSDAY...MAINLY VFR.
MTF
&&
.MARINE...
341 PM CDT
A TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY ARE
SITUATED ACROSS THE UPPER MISSISSIPPI VALLEY EAST ACROSS TO THE
SOUTHERN GREAT LAKES REGION...WITH THESE FEATURES STEMMING FROM AN
AREA OF LOW PRESSURE SITUATED OVER THE CENTRAL PLAINS. ITS THESE
FEATURES THAT ARE PROVIDING...AND WILL CONTINUE TO PROVIDE
DRASTICALLY VARYING CONDITIONS ACROSS THE ENTIRE LAKE. A LIGHTER
WIND FIELD IS CURRENTLY PRESENT OVER THE SOUTHERN PORTIONS OF THE
LAKE WHERE THE PRESSURE GRADIENT IS RELAXED...BUT WITH SPEEDS
INCREASING TO 15 TO 25 KT FOR THE FAR NORTHERN PORTIONS OF THE
LAKE. THIS BOUNDARY WILL LIFT BACK NORTH ACROSS THE LAKE TONIGHT
INTO SATURDAY WHILE THIS LOW PRESSURE SYSTEM SLOWLY TRACKS
NORTHEAST TOWARDS THE MISSISSIPPI VALLEY. AS THIS OCCURS...EXPECT
A GRADUAL TRANSITION TO THE EAST SOUTHEAST WITH SPEEDS INCREASING
ACROSS THE ENTIRE LAKE. EXPECT THE HIGHEST SPEEDS OF 30KT TO BE
OBSERVED ACROSS THE NORTH...WITH THESE EASTERLY WINDS/SPEEDS
LIKELY PERSISTING INTO EARLY SATURDAY NIGHT. EXPECT THIS LOW TO
THEN CONTINUE NORTHEAST AND REACH THE CENTRAL GREAT LAKES LATE
SATURDAY NIGHT INTO SUNDAY...AND THEN CONTINUE EAST TOWARDS THE
EASTERN GREAT LAKES SUNDAY NIGHT INTO MONDAY. AS THIS
OCCURS...EXPECT SPEEDS TO DIMINISH WHILE BECOMING MORE SOUTHERLY
ON SUNDAY AND THEN WEST/NORTHWEST INTO MONDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ005-ILZ006 UNTIL 8 AM SATURDAY.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
301 AM CDT Sat Oct 5 2013
.DISCUSSION...
ISSUED 301 AM CDT Sat Oct 5 2013
After a stormy day across central Illinois today, much cooler
weather will arrive for early next week.
07z/2am surface map shows 1000mb low centered over South Dakota,
with cold front extending southeastward into Iowa/Missouri. Very
warm and humid airmass remains in place ahead of the front, with
temps in the 70s and dewpoints in the upper 60s. Meanwhile,
sharply colder conditions are noted further west behind the
boundary where readings are only in the 30s across the Dakotas and
Nebraska.
SHORT TERM...Today through Monday
Deep upper-level low currently spinning over South Dakota will be
the main weather-maker across the region for the next couple of
days. As this system slowly wobbles eastward, it will push a
strong cold front through central Illinois later today into tonight.
00z models have slowed eastward progression of the front just a bit,
bringing it into the Illinois River Valley by around 21z/4pm.
Given occluded nature of system, this slower trend seems
reasonable. As such, have lowered POPs across the western KILX CWA
into the chance category during the morning hours, opting to hit
POPs hardest during the afternoon and evening as best forcing
arrives. The front will have plenty of moisture to work with as
forecast soundings show precipitable water values greater than
1.50. The airmass will also be moderately unstable, with CAPE
values ranging from 1500 to 2000J/kg. Main mitigating factor for
widespread severe weather will be weak wind fields/shear. While
instability axis will be positioned across Illinois and the Ohio
River Valley this afternoon, strongest wind shear will be
displaced well to the west across Iowa and Missouri. With these
two key severe weather parameters not coinciding with one another,
am not expecting a major severe event today. Thunderstorms will
increase in areal coverage during the afternoon, with perhaps a
few of them producing severe wind gusts. Outside of thunderstorms,
it will be another very warm day with highs ranging from the
middle 70s west to the lower 80s east. Based on expected speed of
front, temps will likely drop into the 60s along/west of the
Illinois River late this afternoon after FROPA.
Due to slower frontal movement, have increased POPs tonight. Will
carry likely to categorical POPs along/east of the Illinois River
during the evening, with best rain chances shifting to the I-57
corridor and eastward after midnight. Once front passes, skies
will clear across the Illinois River Valley late tonight. Low
temperatures will range from the lower 40s far west around
Galesburg and Rushville, to the upper 50s near the Indiana border.
Will linger some shower chances along/east of I-57 through Sunday
morning, as front slowly progresses eastward across Indiana. Mid-level
dry slot behind front and immediately ahead of slowly approaching
upper low will allow skies to be partly to mostly sunny across the
central and western CWA Sunday morning before clouds begin to
increase from the west by late in the day. Given slow movement of
system, have pulled back POPs from previous forecast to feature
only a slight chance for showers across the far west Sunday afternoon.
Cold core upper low will track overhead Sunday night into Monday,
creating a chilly and showery weather pattern. NAM/GFS/GEM are all
in excellent agreement with the position of the 500mb closed low
over Illinois by 12z Mon. Meanwhile, the latest run of the ECMWF
has made a drastic shift from its previous solution, now placing
the low over Michigan Monday morning. Will reject the ECMWF in
favor of the model consensus here. As a result, have added low
POPs for showers both Sunday night and Monday. Have also lowered
highs considerably for Monday, with readings only reaching the
lower 60s.
LONG TERM...Tuesday through Friday
Once upper low lifts further northeast, upper heights will once
again be on the rise across the central and eastern CONUS next
week. 850mb temps respond accordingly, with readings back into the
14 to 16c range by Thursday and Friday. This will support highs
well into the 70s and perhaps the lower 80s by the end of the week.
Barnes
&&
.AVIATION...
ISSUED 1151 PM CDT Fri Oct 4 2013
Latest runs of the high resolution models and the 00z NAM/GFS
indicate that the aviation forecast for central IL TAF sites needs
few changes from the previous issuance.
Still looking for light fog/mist to form toward early morning,
although it is looking less likely that a stratus ceiling will
develop. Plenty of high and mid clouds from upstream convective
debris will move into central and eastern Illinois overnight.
Radar trends, as well as the latest HRRR and RAP forecasts,
indicating that convective remnants to approach central Illinois
shortly after daybreak ahead of the cold front. Plenty of moisture,
instability and increasing low/mid level wind shear will be
present for t-storms to redevelop in a linear fashion by early
afternoon. Maintained the predominant thunderstorm forecast to
account for this expected development and movement of a line of
storms.
The higher resolution models were also indicating that the front
will move a bit slower than previously forecast. Thus, the 06z TAFs
will extend the thunderstorms a couple of hours from the previous
forecast, and also hold off the frontal passage/wind shift until
late afternoon- evening.
Miller
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
105 AM CDT SAT OCT 5 2013
.DISCUSSION...
804 PM CDT
THIS EVENING...WARM FRONT STRETCHES FROM NEAR DBQ ESE TO JOT...THEN
EAST TO VPZ. TEMPERATURES CONTINUE TO RUN IN THE MID TO UPPER 70S
SOUTH OF THE FRONT...WITH DEWPOINTS INTO THE MID TO UPPER 60S. NORTH
OF THE BOUNDARY...TEMPERATURES QUICKLY TAPER INTO THE MID 60S...WITH
LOW DEW POINT DEPRESSIONS. FOG/LOW STRATUS ALREADY STARTING TO
DEVELOP ACROSS THESE AREAS...AND SHOULD CONTINUE TO EXPAND OVERNIGHT.
REMOVED PRECIP MENTION OVERNIGHT FOR ALL BUT THE NORTHERN TIER OF
COUNTIES. LAST VISIBLE SATELLITE IMAGES BEFORE SUNSET SHOWED CU
FIELD QUICKLY DISSIPATING...AND THE MAIN IMPETUS FOR ANY PRECIP
OVERNIGHT IS NEAR THE IL/WI STATE LINE WHERE THE BEST FOCUSED
ISENTROPIC ASCENT IS NOTED. FORECAST OTHERWISE ON TRACK WITH ONLY
MINOR TWEAKS TO THE HOURLY TRENDS.
DEUBELBEISS
//PREV DISCUSSION...
240 PM
FOR THE REMAINDER OF THE AFTERNOON THROUGH SATURDAY...THE MAIN
CONCERN WILL BE SEVERE WEATHER POTENTIAL...WITH A SECONDARY CONCERN
FOR TEMPERATURES.
EARLY THIS AFTERNOON...CONVECTIVE ACTIVITY IS FOCUSING ON THE NOSE
OF A STRONG LOW LEVEL JET POINTING INTO NRN IL...WHICH IS ENHANCING
THE ISENTROPIC LIFT ALREADY IN PLACE AS WARM MOIST AIR CONTINUES TO
STREAM INTO THE REGION. A SECONDARY FOCUS OF CONVECTIVE ACTIVITY IS
A SFC TROUGH/SECONDARY WARM FRONT EXTENDING FROM NRN MO...THROUGH
NRN IL AND NRN INDIANA. LATEST RADAR IMAGERY SHOWS THE WARM
ADVECTION CONVECTION ALREADY INTO NWRN IL AND WITH COPIOUS AMOUNTS
OF HEAT...TEMPS IN THE UPPERS 70S-LOW 80S...MOISTURE...DEWPOINTS IN
THE UPPER 60S TO LOWERS 70S...AND INSTABILITY...MIXED LAYER CAPE OF
1500-2000 J/KG...EXPLOSIVE CONVECTION IS QUITE POSSIBLE WHERE ALL
ELEMENTS LINE UP JUST RIGHT. WITH THE LOW LEVEL JET OF 30KT+ OVER
THE AREA...STRONGER WINDS CAN CERTAINLY MIX DOWN TO THE SURFACE.
THE ONE QUESTION MARK AT THIS TIME IS THE CLOUD COVER. LATEST
SATELLITE IMAGERY SHOWS DENSE OVC OVER NRN IL...WITH MORE
CONVECTIVELY DRIVEN CU/TOWERING CU SOUTH OF THE I-80 CORRIDOR. OF
PARTICULAR CONCERN IS THE SECONDARY WARM FRONT...WHICH LIES IN THE
AREA OF GREATER SFC INSOLATION SOUTH OF I-80. THE 12Z ILX SOUNDING
INDICATES AT LEAST SOME VEERING OF WINDS THROUGH THE LOWER LEVELS
WHICH WOULD HELP ADD SOME ROTATIONAL ASPECT TO STORMS...WHICH IN
TURN COULD ADD A LARGE HAIL OR TORNADIC POTENTIAL TO THE STRONG WIND
THREAT. ON TOP OF ALL OF THIS WILL BE A HEAVY RAINFALL POTENTIAL.
THE 12Z KDVN SOUNDING INDICATES PWAT OF 1.4 INCHES...SO DEEP LAYER
MOISTURE IS ALREADY IN PLACE. THE VARIOUS MODEL FORECAST PWATS
INDICATE THAT A CORRIDOR OF EXTREME DEEP LAYER MOISTURE POOLING IN A
CORRIDOR FROM SWRN WISCONSIN TO NERN KANSAS. WITH TIME AND
PROGRESSION OF THE PATTERN...EXPECT THAT PWATS WILL ONLY INCREASE
OVER THE LOCAL AREA THROUGH THE NEXT 36HRS. THE KDVN PWAT
CLIMATOLOGY INDICATES THAT FOR OCTOBER...2 STANDARD DEVIATIONS FROM
NORMAL IS 1.6 INCHES AND THE 99TH PERCENTILE PWAT IS 1.9 INCHES.
THE LATEST MODEL RUNS SHOW PWAT INCREASING TO IN EXCESS OF 1.5
INCHES IN THE ENVIRONMENT AHEAD OF THE APPROACHING COLD FRONT.
SO...FOR THE SEVERE WEATHER THREAT...TIMING AND COVERAGE ARE THE BIG
QUESTIONS. ANTICIPATE THAT THE GREATEST SEVERE WEATHER THREAT WILL
BE WITH THE COLD FRONT DUE TO THE GREATER SFC FORCING WHICH WILL
LINE UP WITH THE FAVORABLE UPPER DYNAMICS WITH THE UPPER TROUGH.
HOWEVER...THERE WILL STILL BE A MORE ISOLATED SEVERE WEATHER THREAT
ACROSS THE LOCAL AREA SIMPLY DUE TO THE UNSEASONABLY STRONG LOWER
LEVEL THERMODYNAMICS AND EXTREME DEEP LAYER MOISTURE. ALONG WITH
THE SEVERE WEATHER THREAT...HEAVY RAINFALL AND LOCALIZED FLOODING
WILL BE A CONCERN. THE PRIMARY LOCATION FOR POSSIBLE FLOODING WILL
BE ALONG THE SECONDARY WARM FRONT AS RADAR TRENDS INDICATE THAT THE
BOUNDARY ITSELF IS QUASISTATIONARY WHILE INDIVIDUAL CELLS TRACK TO
THE EAST. THE CURRENT CONVECTIVE ACTIVITY ALONG THIS BOUNDARY IS
CURRENTLY OVER NRN INDIANA...BUT RADAR SHOWS A FINE-LINE WEST INTO
NERN IL. IF CONVECTION FILLS IN ALONG THE BOUNDARY AND IT REMAINS
QUASISTATIONARY OR AT LEAST SLOWLY PROGRESSIVE...LOCALIZED FLOODING
WILL BECOME AN INCREASING CONCERN.
FOR TIMING OF THE PROGRESSION OF THE COLD FRONT...THE VARIOUS MODELS
HAVE CONVERGED INTO GOOD AGREEMENT ON THE PROGRESSION...CROSSING THE
RIVER INTO NWRN IL BY ARND 12Z SATURDAY AND STEADILY PROGRESSING EWD
TO NRN INDIANA BY LATE AFTERNOON OR EARLY EVENING. THE THUNDERSTORM
THREAT SHOULD BE CONFINED TO A ZONE ALONG AND AHEAD OF THE FRONT.
FOLLOWING THE FRONTAL PASSAGE...CONDITIONS SHOULD QUICKLY
IMPROVE...FOR A TIME...WITH TEMPERATURES DROPPING OFF QUICKLY.
TEMPERATURES WILL DROP OFF FROM HIGHS IN THE LOW TO MIDDLE 80S TODAY
AND SATURDAY TO LOWS IN THE UPPER 40S TO MIDDLE 50S SUNDAY MORNING
AND LOWS IN THE MIDDLE 40S BY MONDAY MORNING. HIGHS FOR SUNDAY AND
MONDAY SHOULD BE IN THE LOWER TO MIDDLE 60S. THERE WILL STILL BE
SOME CHANCE FOR SOME PCPN SUNDAY AND MONDAY AS THE CENTER OF THE
UPPER LOW TRACKS RIGHT OVER NRN IL/IN...BUT ANY PCPN SHOULD
GENERALLY BE SCT SHOWERS AND PCPN AMOUNTS GENERALLY LIGHT.
FOR THE EXTENDED FORECAST PERIOD...FROM TUESDAY THROUGH
FRIDAY...EXPECT A PERIOD OF SLOWLY MODERATING TEMPERATURES WITH
LITTLE TO NO CHANCE OF PCPN. FOLLOWING THE PASSAGE OF THE UPPER
LOW...A BUILDING UPPER LEVEL RIDGE WILL SLOWLY MOVE OUT OVER THE
PLAINS AND MISSISSIPPI VALLEY AS ANOTHER DEEP UPPER LOW DROPS DOWN
THE WEST COAST INTO THE DESERT SOUTHWEST. THE AMPLIFYING...BUT
SLOWLY PROGRESSIVE PATTERN ALOFT WILL KEEP CONDITIONS DRY WITH ABOVE
NORMAL TEMPS OVER THE LOCAL WITH HIGHS IN THE LOWER TO MIDDLE 70S
AND LOWS IN THE UPPER 40S TO MIDDLE 50S.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LOWERING VISIBILITY AND CIGS INTO IFR CATEGORY INTO OVERNIGHT.
* NORTHEAST WINDS BECOMING EAST THEN SOUTHEAST TONIGHT WITH SPEEDS
MOST OF TIME BELOW 10 KT.
* SMALL CHANCE OF TSRA SAT MORNING GRADUALLY INCREASING INTO MID-
AFTERNOON.
* THUNDERSTORMS LIKELY 22Z-00Z SOME OF WHICH COULD BE STRONG.
BEACHLER
//DISCUSSION...UPDATED 06Z...
VERY CHALLENGEING AVIATION CONDITIONS ARE IN STORE FOR THE NEXT 24
HOURS ACROSS THE REGION...ESPECIALLY OVER NORTHERN IL/NORTHWEST
IN. A STALLED FRONTAL BOUNDARY WAS ORIENTED ACROSS NORTHERN
IL...WHICH HAS RESULTED IN LIGHT WINDS TO AT TIMES CALM FOR
DPA/ORD/MDW/GYY. IN ADDITION VERY MOIST AIR WAS OVER THESE
AIRFIELDS AND HAS RESULTED IN VSBYS BEING REDUCED. IT APPEARS ORD
SHOULD ONLY REDUCE TO ARND 3-4SM OVERNIGHT...HOWEVER ELSEWHERE
MDW/GYY/DPA/RFD WILL LIKELY SEE VSBYS DOWN BTWN 1/2SM AT RFD/DPA
TO 2-3SM AT GYY/MDW. IR IMAGERY INDICATED SOME IFR CIGS WERE
DEVELOPING OVER FAR NORTHWEST IL WHICH HAS BROUGHT CIGS DOWN AT
RFD...AND IT IS POSSIBLE CIGS COULD DROP TO ARND 200-300FT AGL
BEFORE DAYBREKA THEN SLOWLY IMPROVE AFT DAYBREAK.
THEN THE FOCUS TURNS TOWARDS CONVECTIVE TIMING/PLACEMENT LATER
TODAY. AFTER SUNRISE VSBYS SHUD BE SLOW TO IMPROVE WITH JUST A
CIRRUS SHIELD EXPECTED OVERHEAD TO START THE DAY. THE COLD FRONT
WILL BE WELL WEST OF THE REGION...HOWEVER STEADILY PIVOTING EAST
TOWARDS NORTHERN IL AIRFIELDS. GUIDANCE CONTINUES TO INDICATE
WINDS BY MID MORNING WILL BECOME SOUTHERLY ARND 10KT AND
OCCASIONAL GUSTS TO THE MID-TEENS ARE LIKELY. CLOUDS WILL THICKEN
BY MIDDAY WITH A DECK ARND 3-4KFT AGL. WITH CONSIDERABLE ELEMENTS
SUGGESTING CONVECTION WILL BE FIRING ARND 18-19Z...IT IS LIKELY
THAT THE BEST CHC FOR CONVECTION WILL BE ARND 19Z-00Z...AND THE
BETTER COVERAGE WILL FALL WITHIN A 22-00Z TIMEFRAME. WINDS WILL
SLOWLY TURN TO THE 240-260 DEG RANGE FRONTAL PASSAGE...WITH
RAIN/THUNDER SLOWLY ENDING AFT 03-06Z SUN.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN STABLE/SLIGHTLY LOWERING TREND OF
CIG...MEDIUM CONFIDENCE ON VISIBILITY. MEDIUM CONFIDENCE ON HOW
LOW CIG AND VISIBILITY WILL FALL.
* MEDIUM-HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE ON TSRA TIMING OF 21Z-02Z.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR DURING THE DAY WITH MVFR CIGS AND CHC SHRA DURING THE
NIGHT.
MONDAY...CHC OF MVFR AND SLT CHC OF SHRA DURING THE MORNING.
TUESDAY-THURSDAY...MAINLY VFR.
MTF
&&
.MARINE...
341 PM CDT
A TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY ARE
SITUATED ACROSS THE UPPER MISSISSIPPI VALLEY EAST ACROSS TO THE
SOUTHERN GREAT LAKES REGION...WITH THESE FEATURES STEMMING FROM AN
AREA OF LOW PRESSURE SITUATED OVER THE CENTRAL PLAINS. ITS THESE
FEATURES THAT ARE PROVIDING...AND WILL CONTINUE TO PROVIDE
DRASTICALLY VARYING CONDITIONS ACROSS THE ENTIRE LAKE. A LIGHTER
WIND FIELD IS CURRENTLY PRESENT OVER THE SOUTHERN PORTIONS OF THE
LAKE WHERE THE PRESSURE GRADIENT IS RELAXED...BUT WITH SPEEDS
INCREASING TO 15 TO 25 KT FOR THE FAR NORTHERN PORTIONS OF THE
LAKE. THIS BOUNDARY WILL LIFT BACK NORTH ACROSS THE LAKE TONIGHT
INTO SATURDAY WHILE THIS LOW PRESSURE SYSTEM SLOWLY TRACKS
NORTHEAST TOWARDS THE MISSISSIPPI VALLEY. AS THIS OCCURS...EXPECT
A GRADUAL TRANSITION TO THE EAST SOUTHEAST WITH SPEEDS INCREASING
ACROSS THE ENTIRE LAKE. EXPECT THE HIGHEST SPEEDS OF 30KT TO BE
OBSERVED ACROSS THE NORTH...WITH THESE EASTERLY WINDS/SPEEDS
LIKELY PERSISTING INTO EARLY SATURDAY NIGHT. EXPECT THIS LOW TO
THEN CONTINUE NORTHEAST AND REACH THE CENTRAL GREAT LAKES LATE
SATURDAY NIGHT INTO SUNDAY...AND THEN CONTINUE EAST TOWARDS THE
EASTERN GREAT LAKES SUNDAY NIGHT INTO MONDAY. AS THIS
OCCURS...EXPECT SPEEDS TO DIMINISH WHILE BECOMING MORE SOUTHERLY
ON SUNDAY AND THEN WEST/NORTHWEST INTO MONDAY.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1151 PM CDT Fri Oct 4 2013
.DISCUSSION...
ISSUED 850 PM CDT Fri Oct 4 2013
Updated the forecast for tonight to increase the PoPs early in
southeast IL for the isolated showers and few rumbles of thunder.
Also dropped the PoPs a bit in areas west of the IL River. Radar
trends with the convection in Iowa and western Missouri, along
with high res model solutions from the HRRR and RAP, indicate that
the showers and t-storms may not impact west central IL until
close to daybreak.
Otherwise, the forecast low temperatures, sky cover and wind are
all on track for the rest of tonight.
&&
.AVIATION...
ISSUED 1151 PM CDT Fri Oct 4 2013
Latest runs of the high resolution models and the 00z NAM/GFS
indicate that the aviation forecast for central IL TAF sites needs
few changes from the previous issuance.
Still looking for light fog/mist to form toward early morning,
although it is looking less likely that a stratus ceiling will
develop. Plenty of high and mid clouds from upstream convective
debris will move into central and eastern Illinois overnight.
Radar trends, as well as the latest HRRR and RAP forecasts,
indicating that convective remnants to approach central Illinois
shortly after daybreak ahead of the cold front. Plenty of moisture,
instability and increasing low/mid level wind shear will be
present for t-storms to redevelop in a linear fashion by early
afternoon. Maintained the predominant thunderstorm forecast to
account for this expected development and movement of a line of
storms.
The higher resolution models were also indicating that the front
will move a bit slower than previously forecast. Thus, the 06z TAFs
will extend the thunderstorms a couple of hours from the previous
forecast, and also hold off the frontal passage/wind shift until
late afternoon- evening.
Miller
&&
.PREV DISCUSSION...
ISSUED 300 PM CDT Fri Oct 4 2013
The current heat and humidity will be displaced by a chilly
Canadian airmass after a strong cold front moves through on
Saturday. Severe weather potential will increase as we head into
Saturday afternoon, especially if sunshine is able to help
destabilized the boundary layer for any portion of the day. A
slight risk for severe storms has been outlined by SPC for nearly
all of Illinois. The timing of the front remains in question, with
a compromise used between the faster NAM/Canadian and the slower
GFS/ECMWF. That basically allowed for some consistency with the
going forecast. Dry air will be wrapping into the back side of the
cold front, but as the occlusion process occurs, bands of moisture
will trail the front and allow for a few post frontal showers to
linger into Sunday and possibly even Monday.
SHORT TERM...Tonight through Sunday night.
A Pacific moisture connection will continue to feed into the warm
sector across the nations heartland over the next 24-36 hours...as
the warm front lingers in N Iowa and S Wisconsin. Localized
pockets of energy will tap into that moisture to fuel isolated
showers in our SE counties as well as our far NW counties into
this evening. Most areas should remain dry this evening, and even
overnight. We left a wide area of slight chance pops across the
area after midnight, with chance PoPs in the far NW closer to the
expected storm track.
Tonight and early Saturday, low pressure in the western plains will
lift north into eastern South Dakota before stalling during
occlusion. It`s eastward progression will pick up speed as a
kicker trough enters the northwest coast. The timing of the front
will be key in where severe potential is maximized, mainly from
the amount of sunshine for low level heating. There may be some
isolated severe storms overnight west of our area as the nocturnal
jet intensifies ahead of the cold front. The cold front is
projected to reach the I-55 corridor by Noon or 1 pm, then slow
down and reach the Indiana border mid- evening.
Instability params and hodographs are pointing toward damaging
winds as the main hazard in our area, with better directional
shear and rotating storms farther north near the warm front and
track of the low. Hail potential will increase closer to the cold
front and moisture pooling and updraft strength intensify. Severe
chances will linger into the evening east of I-57, but should
become more isolated as the front slows down.
We kept likely PoPs east of I-57 Sat eve, and near the Indiana
border after midnight. Coverage of storms will likely diminish Sat
night as will intensity. Some clearing behind the cold front will
low temps drop into the 40s by Sunday morning west of I-55.
The cold air will limit highs on Sunday to the upper 50s near GBG
and mid 60s near LWV. Scattered rain will be possible across
the east and north associated with cold pool-instability
showers...as the upper trough lingers just west of IL.
Sunday night will be coldest night of the next week, with lows in
the low to mid 40s everywhere.
LONG TERM...Monday through Friday.
The upper vortex may still be over IL on Monday if the GFS and
ECMWF verify, which would put showers across IL during the day. We
left Mon dry for now, but at least sprinkles may be needed if the
next couple of model runs show the slower progression.
A warming trend will begin on Tue and continue through Friday.
Highs should reach above normal into the mid 70s Thur/Fri. Dry
conditions are expected to prevail all week, with comfortable
humidity levels. The next chance of rain may hold off until the
Sunday Oct 13.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
154 PM EDT SAT OCT 5 2013
.SYNOPSIS...
ISSUED AT 342 AM EDT SAT OCT 5 2013
A LARGE LOW PRESSURE SYSTEM WILL BRING INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS THROUGH EARLY NEXT WEEK. THIS LOW
PRESSURE SYSTEM WILL ALSO SEND A COLD FRONT THROUGH THE AREA WITH
TEMPERATURES RETURNING TO NEAR NORMAL VALUES AFTER HIGHS IN THE
LOW 80S AGAIN TODAY.
&&
.UPDATE...
ISSUED AT 1125 AM EDT SAT OCT 5 2013
A COUPLE OF SMALL SCALE EMBEDDED WAVES IN SOUTHWEST UPPER FLOW
HAVE RESULTED IN CLUSTERS OF SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS CENTRAL/NORTHEAST INDIANA. ADDITIONAL SCATTERED SHOWERS AND
THUNDERSTORMS CONTINUE TO DEVELOP OTHER SOUTHERN LAKE MICHIGAN IN
CLOSER PROXIMITY TO MORE PRONOUNCED UPPER LEVEL DIFFLUENCE
DOWNSTREAM OF VIGOROUS NORTHERN PLAINS UPPER TROUGH. AREAS
ROUGHLY ALONG AND SOUTHEAST OF A HUNTINGTON INDIANA TO FORT WAYNE
INDIANA TO DEFIANCE LINE HAVE LIKELY RECEIVED BETWEEN A HALF INCH
TO AN INCH OF RAINFALL SO FAR THIS MORNING. SOME OF THESE SAME
LOCATIONS ACROSS NORTHWEST OHIO HAVE ALSO RECEIVED HEAVY RAINFALL
YESTERDAY. GIVEN INCREASING CONFIDENCE IN SIGNIFICANT RAINFALL
LATE TONIGHT INTO SUNDAY EVENING ALONG WITH RECENT HEAVY
RAIN...WILL BE ISSUING A FLASH FLOOD WATCH SHORTLY FOR FAR
NORTHEAST INDIANA...PORTIONS OF SOUTH CENTRAL LOWER
MICHIGAN....AND ALL OF NORTHWEST OHIO COUNTIES FROM 06Z TONIGHT TO
06Z MONDAY.
IN TERMS OF CONVECTIVE POTENTIAL...15Z RUC ANALYSIS DEPICTS
1000-1500 J/KG OF 100 HPA MLCAPES ACROSS MUCH OF WESTERN HALF OF
THE AREA WITH 0 TO 6 KM BULK SHEAR VALUES IN THE 25 TO 30 KNOT
RANGE. DESPITE SIGNIFICANT CLOUD COVER...DEEP MOISTURE PROFILES
SHOULD CONTINUE TO YIELD CAPES ON THE ORDER OF 1000-1500 J/KG
THIS AFTERNOON. DEEP LAYER SHEAR TO ALSO INCREASE LATE AFTERNOON
ACROSS WESTERN HALF OF THE AREA AS A 500 HPA SPEED MAX LIFTS INTO
NORTHWEST INDIANA AFTER 21Z. THUS...NO CHANGE IN THINKING FROM
PREVIOUS FORECAST WITH LOW/ISOLATED SEVERE THREAT ACROSS
ESPECIALLY WESTERN AREAS LATE AFTERNOON/EARLY EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM EDT SAT OCT 5 2013
GRADUAL APPROACH OF IMPRESSIVE CLOSED OFF CYCLONIC GYRE EXTENDING
THROUGH THE BULK OF THE TROPOSPHERE WILL BRING INCREASING CHANCES
FOR RAIN THROUGH THE SHORT TERM PERIOD. SURFACE FRONTAL BOUNDARY
EXTENDING INTO THE SOUTHERN GREAT LAKES WILL MOVE LITTLE THROUGH
THE PERIOD WITH PERSISTENT THETA-E ADVECTION IN A LARGELY UNCAPPED
ENVIRONMENT LEADING TO CONTINUED PERIODS OF CONVECTION. SMALL
SCALE VORTICES IN SOUTHWEST FLOW ALOFT EMANATING FROM THE CENTRAL
CONUS WILL ALSO SUPPORT INCREASING CHANCES FOR RAINFALL AS THE
MAIN SYSTEM APPROACHES. OCCLUSION PROCESS IS ALREADY BEGINNING AND
EARLIER NOTED SLOWING TREND HAS CONTINUED. MAIN SURFACE COLD FRONT
IS NOT EXPECTED TO REACH OUR CWA UNTIL LATE TONIGHT. WILL STILL BE
PLENTY OF RAIN AHEAD OF THE MAIN FRONT THOUGH. TIGHTENING LOW
LEVEL MASS GRADIENT ASSOCIATED WITH APPROACHING PV ANOMALY WILL
LEAD TO A STRENGTHENING OF THE LLJ AND A CORRESPONDING UPTICK IN
305K ISENTROPIC ASCENT. MOISTURE WILL CERTAINLY NOT BE LACKING
EITHER. 305K MIXING RATIOS ARE ABOVE 8 G/KG AND PW VALUES ARE
HOVERING AROUND 1.75 INCHES...NEAR THE 99TH PERCENTILE FOR THIS
TIME OF YEAR BASED ON REGIONAL UPPER AIR CLIMATOLOGY. EXACT
TIMING/PLACEMENT OF CONVECTION REMAINS HIGHLY UNCERTAIN BUT EXPECT
COVERAGE TO INCREASE AS THE DAY WEARS ON GIVEN INCREASING DIURNAL
INSTABILITY AND APPROACHING TROUGH. LATEST HI-RES GUIDANCE SHOWS
CONVECTION NEAR INDIANAPOLIS WILL CONTINUE TO SPREAD NORTH THROUGH
THE MORNING WITH A BRIEF BREAK BEFORE ADDITIONAL CONVECTION
ARRIVES IN THE LATE AFTERNOON. TRIED TO INCORPORATE THIS INTO THE
LATEST POP FORECAST BUT MAINTAINED FAIRLY BROADBRUSH APPROACH
GIVEN UNCERTAINTY IN CONVECTIVE TRENDS. HIGHER CONFIDENCE THAT
SHOWERS AND THUNDERSTORMS WILL BECOME WIDESPREAD BY TONIGHT THOUGH
AS THE COLD FRONT APPROACHES...AND HAVE PUSHED POPS INTO
CATEGORICAL VALUES. HIGHS TODAY WILL BE SIMILAR TO YESTERDAY...AS
ANY BREAKS IN THE CLOUD COVER WILL ALLOW TEMPS TO MAKE A RUN AT
THE MID 80S GIVEN WARM PROFILES ALOFT. LOWS TONIGHT WILL BE HIGHLY
DEPENDENT ON EXACT TIMING OF FRONT BUT HAVE RAISED THEM A BIT IN
ANTICIPATION OF A SLOWER FRONTAL PASSAGE. LAPSE RATES NEARLY MOIST
ADIABATIC WILL LIKELY ONLY SUPPORT AROUND 1000 J/KG OR LESS OF
SBCAPE TODAY. DEEP LAYER SHEAR IS ALSO MARGINAL DURING THE DAY AND
EXPECT ONLY A SLIGHT CHANCE FOR SEVERE WEATHER...MAINLY IN AREAS
THAT SEE A SUSTAINED PERIOD OF INSOLATION THAT ALLOWS INSTABILITY
TO BUILD. SHEAR WILL INCREASE BY TONIGHT...BUT INSTABILITY WILL BE
AT A MINIMUM AND AGAIN ONLY EXPECTING A LOW RISK OF SEVERE WEATHER
AT THE MOMENT. HEAVY RAIN WILL LIKELY BE THE BIGGEST THREAT. A
VERY MOIST ENVIRONMENT AND CONTINUED POTENTIAL FOR TRAINING STORMS
COULD LEAD TO HIGH RAINFALL TOTALS BY THE TIME ALL IS SAID AND
DONE EARLY NEXT WEEK.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 342 AM EDT SAT OCT 5 2013
RATHER DRAMATIC CHGS REQUIRED TO BEGIN THE PD ON ACCOUNT OF CONTD
MODEL CONSENSUS SLWG IN EWD PROGRESSION OF PLAINS BOWLING BALL.
INTERESTINGLY STILL SOME SIG SPREAD ALOFT STILL AT THIS TIME RANGE
W/POSITION AND INTENSITY OF MID LVL CYCLONE WHICH RANGES FROM NRN IL
IN NAM TO SRN IL IN GEM AT FHR60. REGARDLESS ENOUGH OF A CONSENSUS
SIGNAL EXISTS TO EXTEND/BUMP POPS/WX THROUGH MON NIGHT. HWVR WILL
FORGO ALLBLEND POP GUIDANCE FOR TUE IN LIGHT OF RAPID UPSTREAM HGT
RISES FOLLOWING IN WAKE OF UPR TROUGH WHICH AT THAT POINT SHLD BE IN
SE CANADA.
OF GREATEST INTEREST W/SLWG SOLUTIONS ALOFT IS CONTD PUMP OF
ANOMALOUS GOMEX MSTR FLUX INTO THE GREAT LAKES INADV OF MIDLVL
CYCLONE WHICH SHOWS LTL SIGN OF WKNG UNTIL MON. SLWR EWD ADV OF FNTL
BNDRY ALG W/PWS OF NEAR 1.8IN (99TH PERCENTILE) WOULD PREPOSE AT
LEAST THE ERN HALF OF CWA FOR A CLASSIC MADDOX TYPE I HEAVY RAIN
EVENT AND NOTED IN SVRL DETERMINISTIC QPF SOLUTIONS SUN-SUN NIGHT.
SINCE THIS THREAT IS XPCD TO DVLP DY2 WILL FOLLOWUP PRIOR WELL
DESERVED ESF. AS AN ASIDE...FAIR NUMBER OF SOLUTIONS DEPICT THE
DVLPMNT OF A SFC FNTL WAVE SUN AFTN WHICH IF TRUE WOULD YIELD A
HEIGHTENED RISK FOR LOW TOPPED SUPERCELLS ACRS ERN IN/WRN OH AND
INHERENT TOR THREAT W/FVRBL OVERLAP OF MIXED LYR CAPE/SHEAR.
OTRWS SWD TRENDING PROGRESSION OF AT LEAST MOD INTENSE MID LVL
CYCLONE LEADS TO ADDNL ESCALATION/EXPANSION OF POPS MON AFTN/MON
NIGHT. IN FACT SWD CNTRD CLUSTER OF SVRL SOLUTIONS INCLUDING GFS/GEM
WOULD PORTEND A SECONDARY DEFORMATION ZONE DVLPG IN RESPONSE TO
TRAILING FNTL WAVE MON NIGHT W/ASSUMED SEPARATION W/REMNANTS OF TS
KAREN AS SOME SEMBLANCE OF THE TROWAL REMAINS INTACT.
GIVEN ALL OF THE ABOVE...SIG CHGS TO TEMPS WERE MADE SUN/MON. HWVR
SIG MODERATION STILL ON TAP IN WAKE OF THIS INTENSE SYS MID WEEK
TIMED W/SECONDARY DEEP WRN TROUGH DVLPMNT AND DOWNSTREAM RIDGE
AMPLIFICATION W/RTN TO ABV NORMAL TEMPS XPCD BY THU.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 145 PM EDT SAT OCT 5 2013
CONVECTION BEGINNING TO INCREASE IN COVERAGE FROM SOUTHERN
ILLINOIS INTO SOUTHWEST LOWER MICHIGAN WITH A POCKET OF 1000-2000
J/KG OF 100 HPA MLCAPES ACROSS THE REGION. A COUPLE OF SHORT WAVES
EMBEDDED IN SOUTHWEST UPPER FLOW WILL AID IN EXPANSION OF
SHRA/TSRA COVERAGE THROUGH EARLY EVENING ACROSS NORTH CENTRAL
INDIANA...WITH LIKELIHOOD OF SHOWERS AND EMBEDDED THUNDERSTORMS
OVERSPREADING NORTHEAST INDIANA THROUGH THE EARLY TO LATE EVENING
HOURS. DIURNAL MIXING HAS IMPROVED THE IFR CIGS TO MVFR AT KSBN
EARLY THIS AFTERNOON. HAVE MAINTAINED TEMPO MVFR CONDS IN HEAVIER
SHOWERS AND THUNDERSTORMS THIS AFTERNOON/EARLY EVENING...WITH
TREND BACK TO IFR CONDITIONS LATE EVENING/HOUR NIGHT AS DEEPER
MOISTURE LIFTS NORTHWARD INTO THE AREA. A BRIEF LULL IN COVERAGE
OF SHOWERS AND THUNDERSTORMS IS POSSIBLE IN THE 04Z-08Z
TIMEFRAME...BUT SHOULD INCREASE ONCE AGAIN TOWARD DAYBREAK AS
LARGE SCALE FORCING/LOW LEVEL FRONTOGENESIS INCREASES WITH
APPROACHING UPPER TROUGH
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR INZ007-009-018-026-027-033-034.
MI...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR MIZ081.
OH...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
UPDATE...MARSILI
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...T
AVIATION...MARSILI
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
1147 AM EDT SAT OCT 5 2013
.SYNOPSIS...
ISSUED AT 342 AM EDT SAT OCT 5 2013
A LARGE LOW PRESSURE SYSTEM WILL BRING INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS THROUGH EARLY NEXT WEEK. THIS LOW
PRESSURE SYSTEM WILL ALSO SEND A COLD FRONT THROUGH THE AREA WITH
TEMPERATURES RETURNING TO NEAR NORMAL VALUES AFTER HIGHS IN THE
LOW 80S AGAIN TODAY.
&&
.UPDATE...
ISSUED AT 1125 AM EDT SAT OCT 5 2013
A COUPLE OF SMALL SCALE EMBEDDED WAVES IN SOUTHWEST UPPER FLOW
HAVE RESULTED IN CLUSTERS OF SHOWERS AND ISOLATED THUNDERSTORMS
ACROSS CENTRAL/NORTHEAST INDIANA. ADDITIONAL SCATTERED SHOWERS AND
THUNDERSTORMS CONTINUE TO DEVELOP OTHER SOUTHERN LAKE MICHIGAN IN
CLOSER PROXIMITY TO MORE PRONOUNCED UPPER LEVEL DIFFLUENCE
DOWNSTREAM OF VIGOROUS NORTHERN PLAINS UPPER TROUGH. AREAS
ROUGHLY ALONG AND SOUTHEAST OF A HUNTINGTON INDIANA TO FORT WAYNE
INDIANA TO DEFIANCE LINE HAVE LIKELY RECEIVED BETWEEN A HALF INCH
TO AN INCH OF RAINFALL SO FAR THIS MORNING. SOME OF THESE SAME
LOCATIONS ACROSS NORTHWEST OHIO HAVE ALSO RECEIVED HEAVY RAINFALL
YESTERDAY. GIVEN INCREASING CONFIDENCE IN SIGNIFICANT RAINFALL
LATE TONIGHT INTO SUNDAY EVENING ALONG WITH RECENT HEAVY
RAIN...WILL BE ISSUING A FLASH FLOOD WATCH SHORTLY FOR FAR
NORTHEAST INDIANA...PORTIONS OF SOUTH CENTRAL LOWER
MICHIGAN....AND ALL OF NORTHWEST OHIO COUNTIES FROM 06Z TONIGHT TO
06Z MONDAY.
IN TERMS OF CONVECTIVE POTENTIAL...15Z RUC ANALYSIS DEPICTS
1000-1500 J/KG OF 100 HPA MLCAPES ACROSS MUCH OF WESTERN HALF OF
THE AREA WITH 0 TO 6 KM BULK SHEAR VALUES IN THE 25 TO 30 KNOT
RANGE. DESPITE SIGNIFICANT CLOUD COVER...DEEP MOISTURE PROFILES
SHOULD CONTINUE TO YIELD CAPES ON THE ORDER OF 1000-1500 J/KG
THIS AFTERNOON. DEEP LAYER SHEAR TO ALSO INCREASE LATE AFTERNOON
ACROSS WESTERN HALF OF THE AREA AS A 500 HPA SPEED MAX LIFTS INTO
NORTHWEST INDIANA AFTER 21Z. THUS...NO CHANGE IN THINKING FROM
PREVIOUS FORECAST WITH LOW/ISOLATED SEVERE THREAT ACROSS
ESPECIALLY WESTERN AREAS LATE AFTERNOON/EARLY EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM EDT SAT OCT 5 2013
GRADUAL APPROACH OF IMPRESSIVE CLOSED OFF CYCLONIC GYRE EXTENDING
THROUGH THE BULK OF THE TROPOSPHERE WILL BRING INCREASING CHANCES
FOR RAIN THROUGH THE SHORT TERM PERIOD. SURFACE FRONTAL BOUNDARY
EXTENDING INTO THE SOUTHERN GREAT LAKES WILL MOVE LITTLE THROUGH
THE PERIOD WITH PERSISTENT THETA-E ADVECTION IN A LARGELY UNCAPPED
ENVIRONMENT LEADING TO CONTINUED PERIODS OF CONVECTION. SMALL
SCALE VORTICES IN SOUTHWEST FLOW ALOFT EMANATING FROM THE CENTRAL
CONUS WILL ALSO SUPPORT INCREASING CHANCES FOR RAINFALL AS THE
MAIN SYSTEM APPROACHES. OCCLUSION PROCESS IS ALREADY BEGINNING AND
EARLIER NOTED SLOWING TREND HAS CONTINUED. MAIN SURFACE COLD FRONT
IS NOT EXPECTED TO REACH OUR CWA UNTIL LATE TONIGHT. WILL STILL BE
PLENTY OF RAIN AHEAD OF THE MAIN FRONT THOUGH. TIGHTENING LOW
LEVEL MASS GRADIENT ASSOCIATED WITH APPROACHING PV ANOMALY WILL
LEAD TO A STRENGTHENING OF THE LLJ AND A CORRESPONDING UPTICK IN
305K ISENTROPIC ASCENT. MOISTURE WILL CERTAINLY NOT BE LACKING
EITHER. 305K MIXING RATIOS ARE ABOVE 8 G/KG AND PW VALUES ARE
HOVERING AROUND 1.75 INCHES...NEAR THE 99TH PERCENTILE FOR THIS
TIME OF YEAR BASED ON REGIONAL UPPER AIR CLIMATOLOGY. EXACT
TIMING/PLACEMENT OF CONVECTION REMAINS HIGHLY UNCERTAIN BUT EXPECT
COVERAGE TO INCREASE AS THE DAY WEARS ON GIVEN INCREASING DIURNAL
INSTABILITY AND APPROACHING TROUGH. LATEST HI-RES GUIDANCE SHOWS
CONVECTION NEAR INDIANAPOLIS WILL CONTINUE TO SPREAD NORTH THROUGH
THE MORNING WITH A BRIEF BREAK BEFORE ADDITIONAL CONVECTION
ARRIVES IN THE LATE AFTERNOON. TRIED TO INCORPORATE THIS INTO THE
LATEST POP FORECAST BUT MAINTAINED FAIRLY BROADBRUSH APPROACH
GIVEN UNCERTAINTY IN CONVECTIVE TRENDS. HIGHER CONFIDENCE THAT
SHOWERS AND THUNDERSTORMS WILL BECOME WIDESPREAD BY TONIGHT THOUGH
AS THE COLD FRONT APPROACHES...AND HAVE PUSHED POPS INTO
CATEGORICAL VALUES. HIGHS TODAY WILL BE SIMILAR TO YESTERDAY...AS
ANY BREAKS IN THE CLOUD COVER WILL ALLOW TEMPS TO MAKE A RUN AT
THE MID 80S GIVEN WARM PROFILES ALOFT. LOWS TONIGHT WILL BE HIGHLY
DEPENDENT ON EXACT TIMING OF FRONT BUT HAVE RAISED THEM A BIT IN
ANTICIPATION OF A SLOWER FRONTAL PASSAGE. LAPSE RATES NEARLY MOIST
ADIABATIC WILL LIKELY ONLY SUPPORT AROUND 1000 J/KG OR LESS OF
SBCAPE TODAY. DEEP LAYER SHEAR IS ALSO MARGINAL DURING THE DAY AND
EXPECT ONLY A SLIGHT CHANCE FOR SEVERE WEATHER...MAINLY IN AREAS
THAT SEE A SUSTAINED PERIOD OF INSOLATION THAT ALLOWS INSTABILITY
TO BUILD. SHEAR WILL INCREASE BY TONIGHT...BUT INSTABILITY WILL BE
AT A MINIMUM AND AGAIN ONLY EXPECTING A LOW RISK OF SEVERE WEATHER
AT THE MOMENT. HEAVY RAIN WILL LIKELY BE THE BIGGEST THREAT. A
VERY MOIST ENVIRONMENT AND CONTINUED POTENTIAL FOR TRAINING STORMS
COULD LEAD TO HIGH RAINFALL TOTALS BY THE TIME ALL IS SAID AND
DONE EARLY NEXT WEEK.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 342 AM EDT SAT OCT 5 2013
RATHER DRAMATIC CHGS REQUIRED TO BEGIN THE PD ON ACCOUNT OF CONTD
MODEL CONSENSUS SLWG IN EWD PROGRESSION OF PLAINS BOWLING BALL.
INTERESTINGLY STILL SOME SIG SPREAD ALOFT STILL AT THIS TIME RANGE
W/POSITION AND INTENSITY OF MID LVL CYCLONE WHICH RANGES FROM NRN IL
IN NAM TO SRN IL IN GEM AT FHR60. REGARDLESS ENOUGH OF A CONSENSUS
SIGNAL EXISTS TO EXTEND/BUMP POPS/WX THROUGH MON NIGHT. HWVR WILL
FORGO ALLBLEND POP GUIDANCE FOR TUE IN LIGHT OF RAPID UPSTREAM HGT
RISES FOLLOWING IN WAKE OF UPR TROUGH WHICH AT THAT POINT SHLD BE IN
SE CANADA.
OF GREATEST INTEREST W/SLWG SOLUTIONS ALOFT IS CONTD PUMP OF
ANOMALOUS GOMEX MSTR FLUX INTO THE GREAT LAKES INADV OF MIDLVL
CYCLONE WHICH SHOWS LTL SIGN OF WKNG UNTIL MON. SLWR EWD ADV OF FNTL
BNDRY ALG W/PWS OF NEAR 1.8IN (99TH PERCENTILE) WOULD PREPOSE AT
LEAST THE ERN HALF OF CWA FOR A CLASSIC MADDOX TYPE I HEAVY RAIN
EVENT AND NOTED IN SVRL DETERMINISTIC QPF SOLUTIONS SUN-SUN NIGHT.
SINCE THIS THREAT IS XPCD TO DVLP DY2 WILL FOLLOWUP PRIOR WELL
DESERVED ESF. AS AN ASIDE...FAIR NUMBER OF SOLUTIONS DEPICT THE
DVLPMNT OF A SFC FNTL WAVE SUN AFTN WHICH IF TRUE WOULD YIELD A
HEIGHTENED RISK FOR LOW TOPPED SUPERCELLS ACRS ERN IN/WRN OH AND
INHERENT TOR THREAT W/FVRBL OVERLAP OF MIXED LYR CAPE/SHEAR.
OTRWS SWD TRENDING PROGRESSION OF AT LEAST MOD INTENSE MID LVL
CYCLONE LEADS TO ADDNL ESCALATION/EXPANSION OF POPS MON AFTN/MON
NIGHT. IN FACT SWD CNTRD CLUSTER OF SVRL SOLUTIONS INCLUDING GFS/GEM
WOULD PORTEND A SECONDARY DEFORMATION ZONE DVLPG IN RESPONSE TO
TRAILING FNTL WAVE MON NIGHT W/ASSUMED SEPARATION W/REMNANTS OF TS
KAREN AS SOME SEMBLANCE OF THE TROWAL REMAINS INTACT.
GIVEN ALL OF THE ABOVE...SIG CHGS TO TEMPS WERE MADE SUN/MON. HWVR
SIG MODERATION STILL ON TAP IN WAKE OF THIS INTENSE SYS MID WEEK
TIMED W/SECONDARY DEEP WRN TROUGH DVLPMNT AND DOWNSTREAM RIDGE
AMPLIFICATION W/RTN TO ABV NORMAL TEMPS XPCD BY THU.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 555 AM EDT SAT OCT 5 2013
AREA OF CONVECTION CURRENTLY OVER CENTRAL INDIANA WILL CONTINUE TO
SLOWLY WORK NORTHWARD THIS MORNING...AIDED BY PERSISTENT THETA-E
ADVECTION AND A WEAK SHORTWAVE EMBEDDED IN SOUTHWEST FLOW ALOFT.
PRECIP MAY CLIP KFWA BUT PLAN TO LEAVE OUT THUNDER MENTION SINCE
LIGHTNING HAS BEEN FAIRLY ISOLATED AND MAY PASS TO THE SOUTHEAST
OF THE TERMINAL. SPORADIC SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE FOR MUCH OF THE TAF PERIOD AND TIMING THIS PRECIP WILL BE
NEARLY IMPOSSIBLE MORE THAN A FEW HOURS OUT. HAVE HIGHLIGHTED LATE
AFTERNOON AS THE BEST CHANCE GIVEN DIURNAL INSTABILITY PEAK BUT
SCATTERED CONVECTION WILL BE POSSIBLE THROUGH THE OVERNIGHT PERIOD
WITH MVFR...OR LOWER...CONDITIONS IN THE STRONGER STORMS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR INZ007-009-018-026-027-033-034.
MI...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR MIZ081.
OH...FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT
FOR OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
UPDATE...MARSILI
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
323 PM CDT Sat Oct 5 2013
.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 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1209 PM CDT SAT OCT 5 2013
VFR forecast at KTOP/KFOE/KMHK with west winds gusting between 15
and 23 kts this afternoon. Winds stay up near 10 kts overnight as
upper low passes to the northeast. Latest RAP and high res
guidance are hinting at cigs redeveloping aft 08z at KMHK and 09z
at KTOP/KFOE. Not confident enough to lower to MVFR however
increased VFR cloud coverage at this time and will reevaluate MVFR
potential at next issuance.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1233 PM CDT Sat Oct 5 2013
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 316 AM CDT SAT OCT 5 2013
Closed upper level low is currently centered over central SD with a
well defined mid level dry punch stretched across the central
plains. Surface cold front responsible for yesterday`s thunderstorms
has moved east into western MO. Trailing stratiform behind the main
line of thunderstorms will continue for a few more hours in the far
southeast cwa. An area of scattered showers with isolated thunder is
working through parts of the cwa this morning due to some elevated
instability rooted at around 750 mb. These showers will move
northeast through the cwa during the next few hours exiting the area
by sunrise.
Cold dry air has begun to push into the region behind the front with
temperatures in the mid 40s already in north central KS. Low
temperatures tonight will range from the low 40s in north central KS
to the upper 50s in east central KS. The winds have shifted to the
west northwest and are forecast to increase to around 15 to 20 mph
with gusts up to 30 mph during the day today. Clouds will continue
to move east today with partly to mostly sunny skies expected by
this afternoon and high temperatures in the upper 50s to low 60s.
Cold air advection will persist through out the day today and
tonight. The 850 mb temperatures will approach 0C later tonight
therefore overnight low temperatures drop to around 40 across most
of the area.
.LONG TERM...(Sunday through Friday)
Issued at 316 AM CDT SAT OCT 5 2013
Through Sunday afternoon the upper low is forecast to drop east
southeast out from near Sioux Falls into Missouri. This takes an
area of stratus and the colder air aloft across the northeastern
counties. By afternoon hours, there is enough lift associated with
the low to generate showers through the saturated layer in the
column. In fact 850mb temperatures are running just near or below
freezing, and soundings suggest the top of the lift in the column
just clips where the -10/-20 layer is saturated aloft. However
expect to see enough warmer air in the low levels to keep precip
in the form of rain or a light drizzle. Could go on for a few
hours in the afternoon, and would not be surprised to see some
cold air funnels ad cold pool moves through. This will also keep
high temperatures across the NE down int he 50s with 60s possible
elsewhere.
Mon-Fro continue to advertise a nice warm up through the end of the
week as Monday starts out around 70 and Friday brings highs in the
upper 70s. Lows Sunday night into Morning may be pretty chilly as
skies clear and winds lighten before warm air advection returns.
May see lows around 40 common over the area. These lows slowly
moderate back into the 50s as southwesterly flow aloft returns to
the plains and the next trof approaches the Rockies on Friday.
Will carry just a slight chance for some pops mainly in the
western counties. 67
&&
.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1209 PM CDT SAT OCT 5 2013
VFR forecast at KTOP/KFOE/KMHK with west winds gusting between 15
and 23 kts this afternoon. Winds stay up near 10 kts overnight as
upper low passes to the northeast. Latest RAP and high res
guidance are hinting at cigs redeveloping aft 08z at KMHK and 09z
at KTOP/KFOE. Not confident enough to lower to MVFR however
increased VFR cloud coverage at this time and will reevaluate MVFR
potential at next issuance.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...67
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS JACKSON KY
553 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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 119 PM EDT SAT OCT 5 2013
A LARGE AREA OF LOW PRESSURE OFF TO OUR NE HAS SPAWNED A STRONG COLD
FRONT AND A LARGE AREA OF PRECIPITATION TO ACCOMPANY IT. THIS PRECIP
IS CURRENTLY IMPACTING WESTERN KY...AND PORTIONS OF TN AND OHIO. THE
LINE WILL CONTINUE TO SLOWLY PUSH EASTERLY AHEAD OF THE COLD
FRONT...REACHING THE TAF SITES SOMETIME TOMORROW AFTERNOON. IF MODELS
CONTINUE WITH ONGOING SOLUTIONS...PRECIP SHOULD NOT ARRIVE AT TAF
LOCATIONS UNTIL AFTER THE FORECAST PERIOD. HOWEVER...PUT IN SOME VCSH
AT KSME AND KLON JUST IN CASE THINGS DO IN FACT SPEED UP AND TO
ACCOUNT FOR ANY PRECIP WHICH MAY DEVELOP OUT AHEAD OF THE MAIN LINE.
WITH THAT IN MIND...SOME OF THE HI-RES MODELS ARE ALSO POINTING AT SOME
DEVELOPING ISL TO SCT CONVECTION THIS AFTERNOON AS WELL. BUT WITH NO
EVIDENCE OF ANY SH/TSRA DEVELOPMENT AT THIS TIME IN OUR CWA...CONFIDENCE
ON WHETHER OR NOT THESE CONVECTIVE CELLS WILL AFFECT THE TAF SITES IS
QUITE LOW...SO CHOSE TO LEAVE OUT AT TAFS. IMPOSING CLOUD COVER
TONIGHT SHOULD BE ENOUGH TO KEEP ANY FOG POTENTIAL AT BAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...JMW
LONG TERM...SBH
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
303 PM EDT SAT OCT 5 2013
.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 AIRMASS...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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 119 PM EDT SAT OCT 5 2013
A LARGE AREA OF LOW PRESSURE OFF TO OUR NE HAS SPAWNED A STRONG COLD
FRONT AND A LARGE AREA OF PRECIPITATION TO ACCOMPANY IT. THIS PRECIP
IS CURRENTLY IMPACTING WESTERN KY...AND PORTIONS OF TN AND OHIO. THE
LINE WILL CONTINUE TO SLOWLY PUSH EASTERLY AHEAD OF THE COLD
FRONT...REACHING THE TAF SITES SOMETIME TOMORROW AFTERNOON. IF MODELS
CONTINUE WITH ONGOING SOLUTIONS...PRECIP SHOULD NOT ARRIVE AT TAF
LOCATIONS UNTIL AFTER THE FORECAST PERIOD. HOWEVER...PUT IN SOME VCSH
AT KSME AND KLON JUST IN CASE THINGS DO IN FACT SPEED UP AND TO
ACCOUNT FOR ANY PRECIP WHICH MAY DEVELOP OUT AHEAD OF THE MAIN LINE.
WITH THAT IN MIND...SOME OF THE HI-RES MODELS ARE ALSO POINTING AT SOME
DEVELOPING ISL TO SCT CONVECTION THIS AFTERNOON AS WELL. BUT WITH NO
EVIDENCE OF ANY SH/TSRA DEVELOPMENT AT THIS TIME IN OUR CWA...CONFIDENCE
ON WHETHER OR NOT THESE CONVECTIVE CELLS WILL AFFECT THE TAF SITES IS
QUITE LOW...SO CHOSE TO LEAVE OUT AT TAFS. IMPOSING CLOUD COVER
TONIGHT SHOULD BE ENOUGH TO KEEP ANY FOG POTENTIAL AT BAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JMW
LONG TERM...SBH
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
301 PM EDT SAT OCT 5 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 301 PM EDT SAT OCT 5 2013
ALL MODELS ARE STILL ON TRACK TO BRING US A POTENT AND SLOW MOVING
COLD FRONT THROUGH THE AREA TONIGHT...SUNDAY...AND INTO THE DAY
MONDAY. WILL CONCENTRATE ON TONIGHT THROUGH 0Z MONDAY 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 AIRMASS...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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 119 PM EDT SAT OCT 5 2013
A LARGE AREA OF LOW PRESSURE OFF TO OUR NE HAS SPAWNED A STRONG COLD
FRONT AND A LARGE AREA OF PRECIPITATION TO ACCOMPANY IT. THIS PRECIP
IS CURRENTLY IMPACTING WESTERN KY...AND PORTIONS OF TN AND OHIO. THE
LINE WILL CONTINUE TO SLOWLY PUSH EASTERLY AHEAD OF THE COLD
FRONT...REACHING THE TAF SITES SOMETIME TOMORROW AFTERNOON. IF MODELS
CONTINUE WITH ONGOING SOLUTIONS...PRECIP SHOULD NOT ARRIVE AT TAF
LOCATIONS UNTIL AFTER THE FORECAST PERIOD. HOWEVER...PUT IN SOME VCSH
AT KSME AND KLON JUST IN CASE THINGS DO IN FACT SPEED UP AND TO
ACCOUNT FOR ANY PRECIP WHICH MAY DEVELOP OUT AHEAD OF THE MAIN LINE.
WITH THAT IN MIND...SOME OF THE HI-RES MODELS ARE ALSO POINTING AT SOME
DEVELOPING ISL TO SCT CONVECTION THIS AFTERNOON AS WELL. BUT WITH NO
EVIDENCE OF ANY SH/TSRA DEVELOPMENT AT THIS TIME IN OUR CWA...CONFIDENCE
ON WHETHER OR NOT THESE CONVECTIVE CELLS WILL AFFECT THE TAF SITES IS
QUITE LOW...SO CHOSE TO LEAVE OUT AT TAFS. IMPOSING CLOUD COVER
TONIGHT SHOULD BE ENOUGH TO KEEP ANY FOG POTENTIAL AT BAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JMW
LONG TERM...SBH
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
927 PM EDT SUN OCT 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ALONG THE EASTERN SEABOARD THIS EVENING. A
STRONG COLD FRONT WILL APPROACH THE REGION OVERNIGHT... AND CROSS
THE REGION MONDAY. HIGH PRESSURE BUILDS IN FROM THE WEST TUESDAY
THROUGH THURSDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
A COLD FRONT EXTENDS FROM THE UPPER GREAT LAKES SOUTH THROUGH THE
OHIO VALLEY AND INTO THE GULF COAST STATES REACHING THE REMENENTS OF
WHAT WAS TS KAREN THIS EVENING. HIGH PRESSURE HAS MOVED OFF THE COAST
AND THE MID ATLANTIC IS RECEIVING RETURN FLOW AS SOUTHERLY WINDS
HAVE INCREASED. THE PRESSURE GRADIENT HAS TIGHTENED AND MOISTURE
WILL CONTINUE TO MOVE INTO THE REGION AHEAD OF THE ADVANCING COLD
FRONT.
ALTHOUGH AIR MASS IS STILL QUITE DRY AS 00Z IAD RAOB SHOWS DRY AIR
ALOFT LOW STRATUS CLOUDS WILL FORM ACROSS THE REGION TONIGHT.
THESE CLOUDS ARE STARTING TO SHOW UP ALONG THE MTN RIDGES ON THE 11-3.9
SAT CHANNEL. PER 00Z IAD RAOB...SOUTHERLY FLOW HAS INCREASED TO 25-30 KTS AT
850MB AND WILL INCREASE TO 40 KTS BY 12Z MONDAY. ISENTROPIC LIFT
AND MOISTURE ADVECTION WILL SPREAD LOW CLOUDS NORTHWARD MAKING IT
TO I-95 BY SUNRISE MONDAY MORNING. AS LLJ INCREASES SHOWERS WILL
MOVE INTO THE REGION AS WELL. 3KM HRRR HAS ISO-SCT SHOWERS
FORMING AND MOVING NORTHWARD OVERNIGHT AND INTO MONDAY MORNING. COLD
FRONT WILL BE AT THE ALLEGHENY FRONT MONDAY MORNING AND SHOWERS
AND GUSTY WINDS WILL BEGIN TO PROPAGATE EASTWARD TOWARD THE
CHESAKPEAKE BAY.
&&
.SHORT TERM /MONDAY NIGHT/...
CONDITIONS WILL DETERIORATE ON MONDAY WITH THE APPROACH OF THE
COLD FRONT FROM THE WEST. THE MAIN AREA OF SHOWERS SHOULD CROSS
I-81 AND REACH THE BLUE RIDGE BEFORE NOON...THEN SPREAD EAST
ACROSS THE REMAINDER OF THE REGION BY OR JUST AFTER NOON.
WL BE IN A HIGH SHEAR/LOW CAPE ENVIRONMENT...BUT DEWPTS IN THE MID
60S AND A LOW LVL JET UPWRDS OF 50 KT MAY BE ABLE TO INDUCE SOME
CNVCTV DVLPMNT-- LKLY LOW-TOPPED BUT STILL CAPABLE OF PRODUCING
DOWNDRAFTS AND A FEW SPINNERS. SPC HAS ADDED A SLGT RISK AREA TO
DAY 2 OUTLK...INCL NE MD.
W/ PWAT NEAR 2 INCHES...WL BE PLACING EMPHASIS IN WX GRIDS ON THE
SHRA...AS SOME CNVCTN MAY BE LACKING THUNDER/LTNG. A PLUME OF MSTR
WL BE TRANSPORTED NWD AHD OF CDFNT...W/ PLENTY OF LIFT ALONG FRNTL
BNDRY. HV RAISED POPS TO 100 PCT. ORDINARILY...THESE ANTICIPATED
RAFL RATES IN OCT WUD LEAD TO AUTOMATIC FLASH FLOODING CONCERNS.
HWVR...AREA HAS BEEN SO DRY RECENTLY THAT WL STILL BE HOLDING OFF
ON ANY WATCH ISSUANCE. CANNOT RULE OUT LCLZD ISSUES DUE TO HARD
GRND IF HVY RAFL IS PROLONGED. THAT CUD BE A CONSIDERATION FOR
FCSTRS TNGT/TMRW MRNG.
CDFNT WL BE CROSSING DELMARVA BY ELY-MID EVNG. CLRG SKIES...A
DRYING AMS...AND NW/NLY WNDS WL ENSUE FOR THE BALANCE OF THE NGT.
MOS GDNC FOR MAXT DROPPED QUITE A BIT FM PRVS CYCLES. WHILE AGREE
THAT CLDS/RAFL WL IMPEDE DIURNAL TEMP RISE...AM LEERY OF TEMPS
FALLING OFF TOO MUCH DUE TO STRONG SLY FLOW. SHADED MAXT DOWN ONLY
A CPL DEGF FM PRVS FCST. DID LOWER QUITE A BIT FOR MIN-T MON NGT
THO
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO NEW ENGLAND FROM THE OHIO VALLEY ON
TUESDAY...PUTTING OUR REGION IN NE FLOW WITH MOSTLY CLEAR SKIES.
06/00Z MEX GDNC IS GIVING THE AREA NEAR NORMAL TEMPS WITH HIGHS
AROUND 70 AND NIGHTIME LOWS IN THE MID 40S.
ON THURSDAY...BOTH THE 06/00Z GFS AND 05/12Z ECMWF CUT AN UPPER
LOW OFF THE NC COAST WITH THE SFC REFLECTION A LARGE WARM CORE LOW
PRESSURE SYSTEM. THE AREA OFF THE NC/SC IN OCTOBER IS A FAVORED
REGION FOR LIKELY TROPICAL DEVELOPMENT PER NHC CLIMO DATA. THE
EXTENDED GFS MEANDERS THE LOW OFF THE COAST BEFORE FINALLY TAKING IT
OUT TO SEA. RIGHT NOW RUNNING WITH WPC GUIDANCE FOR DAYS 4-7...WHICH
CONTINUES THE REGION IN NE FLOW AND FAIR WEATHER THROUGH SATURDAY.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED TONIGHT. MVFR/IFR CIGS EXPECTED EARLY
MONDAY MORNING. A STRONG SOUTHERLY JET WILL ADVECT MOISTURE INTO
THE REGION. ISO-SCT SHOWERS ARE POSSIBLE ACROSS THE TERMINALS
OVERNIGHT WHILE HEAVY RAIN APPROACHES MRB BY LATE MONDAY MORNING.
GUSTY WINDS...HEAVY RAIN AND LIGHTNING ARE ALL POSSBILE AHEAD AND
ALONG COLD FRONT. A 40 KT JET AT 240 DEG AT 2K FEET MAY PRODUCE
LLWS MONDAY MORNING BUT CONFIDENCE IS LOW AT THIS TIME.
VSBYS WILL BE REDUCED IN HEAVY SHOWERS AND ISO
THUNDERSTORMS. BEST TIMING WILL BE MONDAY AFTERNOON FOR TS. COLD
FRONT WILL CROSS BWI- MTN BY LATE MON AFTERNOON. NW FLOW BEHIND
FRONT WILL CONTINUE THROUGH TUESDAY MORNING. VFR CONDITIONS
EXPECTED AFTER COLD FRONT.
FOR THE EXTENDED AVIATION BEYOND MONDAY NIGHT...LOOKING FOR VFR
CONDITIONS AT ALL TERMINALS TUESDAY THROUGH THURSDAY WITH NE WINDS
LIKELY AS HIGH IS CENTERED OVER NEW ENGLAND.
&&
.MARINE...
S-SE FLOW WILL CONTINUE ACROSS THE POTOMAC AND BAY TONIGHT AND
MONDAY. A COLD FRONT WILL CROSS THE WATERS MONDAY AFTERNOON AND
HEAVY RAIN AND GUSTY WINDS ARE EXPECTED. SOUTHERLY WINDS MAY GUST
NEAR GALE CRITERIA TOWARDS LATE MONDAY MORNING AS STRONG JET ALOFT
MIXES DOWN. THESE WILL SUBSIDE SOME TOWARDS THE AFTERNOON. WATERSPOUTS
AND LIGHTNING ARE ALSO POSSIBLE AHEAD OF COLD FRONT MON AFTERNOON.
A SCA IS IN EFFECT THROUGH THE FRONTAL PASSAGE MONDAY NIGHT FOR
MOST WATER ZONES. AFTER THE FRONTAL PASSAGE...NW WINDS WILL
INCREASE AND A SCA IS IN EFFECT MONDAY NIGHT INTO EARLY TUESDAY
MORNING FOR THE BAY SOUTH OF NORTH BEACH AND LOWER TIDAL POTOMAC.
NO MORE MARINE HEADLINES EXPECTED THROUGH THE REMAINDER OF THE
MARINE PERIOD/THURSDAY/.
&&
.TIDES/COASTAL FLOODING...
SOUTHERLY FLOW HAS INCREASED AND WILL CONTINUE TO INCREASE AHEAD OF
AN APPROACHING COLD FRONT IN THE OHIO VALLEY.
TIDAL ANOMALIES HAVE INCREASED TO AROUND A FOOT ACROSS THE WESTERN
SHORE OF THE MD CHESAPEAKE BAY AND TIDAL POTOMAC. A CF ADVISORY IS
IN EFFECT FOR THE NEXT HIGH TIDE CYCLES ON THE WESTERN SHORE OF THE
BAY. THE HIGH TIDE FOR DC/SW WATERFRONT IS CURRENTLY REACHING
MINOR THRESHOLD TONIGHT. LOCATIONS THAT HAVE HIGH TIDES PRIOR TO
COLD FRONT PASSAGE WILL BE SUSEPTIBLE TO MINOR INUNDATION.
XPCT TIDAL DEPARTURES TO INCREASE FURTHER ON MON...BUT ITS THE
LOWER OF THE TWO TIDES ASTRONOMICALLY. THAT MAY BALANCE EACH OTHER
OUT. THE EXTENT OF THE SLY FLOW MAY SUGGEST THAT THE MON DAYTIME
TIDE MAY BE THE HIGHEST. GDNC SUGGESTING THAT TOO.
WINDS BECOME NWLY MON EVNG...BUT MAY NOT BE ENOUGH FOR A RAPID
BLOWOUT. TIMING WL BE KEY IN DETERMINING IF THERE WILL BE ISSUES
FOR THE MON NIGHT TIDE CYCLE.
&&
.CLIMATE...
RECORD HIGH TEMP OF 89 DEGREES WAS SET AT IAD TODAY BREAKING THE
OLD RECORD OF 86 DEGREES IN 1995.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...COASTAL FLOOD ADVISORY UNTIL 11 PM EDT THIS EVENING FOR DCZ001.
MD...COASTAL FLOOD ADVISORY FROM 2 AM TO 11 AM EDT MONDAY FOR
MDZ011-014-017-018.
COASTAL FLOOD ADVISORY UNTIL 11 PM EDT THIS EVENING FOR MDZ011-
014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT MONDAY FOR ANZ530-
535-536-538-539.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ531>534-537-
540>543.
SMALL CRAFT ADVISORY FROM 2 AM TO 8 AM EDT TUESDAY FOR
ANZ532>534-537-540>543.
&&
$$
SYNOPSIS...HTS
NEAR TERM...HAS
SHORT TERM...LEE/HAS/HTS
LONG TERM...LEE
AVIATION...LEE/HAS
MARINE...LEE/HAS
TIDES/COASTAL FLOODING...HAS
CLIMATE...HAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
756 PM EDT SUN OCT 6 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 409 PM EDT SUN OCT 6 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE OVER THE WRN CONUS AND
A TROUGH FROM HUDSON BAY INTO NRN ONTARIO. THE PERSISTENT MID/UPPER
LEVEL LOW HAD EDGED EASTWARD INTO ERN IA. AT THE SFC...LOW PRES WAS
LOCATED OVER S CNTRL LAKE SUPERIOR WITH A COLD FRONT INTO CNTRL
LOWER MI AND A TROUGH TO THE SW INTO SE MN. RAIN ASSOCIATED WITH A
WEAK SHORTWAVE IN THE WARM CONVEYOR AHEAD OF THE COLD FRONT WAS
LIFTING NNE THROUGH ERN CWA. OTHERWISE...RADAR INDICATED ONLY VERY
WEAK RETURNS OVER THE WEST WITH SOME SPRINKLES OR DRIZZLE. FARTHER
WEST...A NARROW BAND OF RAIN TO NEAR DLH WAS ASSOCIATED WITH THE MID
LEVEL DEFORMATION/FGEN BAND/TROWAL ON THE NRN FLANK OF THE MID LEVEL
LOW. VIS LOOP SHOWED CLEARING OVER SRN UPPER MI WITH THE ADVANCING
DRY SLOT.
TONIGHT...MODELS SUGGEST THAT THE NE MN RAIN BAND WILL CONTINUE TO
SLOWLY SPREAD INTO WEST UPPER MI THIS EVENING AND GRADUALLY SHRINK
OVERNIGHT...PER FCST 310KE SURFACE. THERE MAY ALSO BE A FEW LIGHT
SHOWERS THROUGH CNTRL UPPER MI THIS EVENING AS THE DRY SLOT AREA
GIVES WAY TO INCREASING CLOUDS WITH INCREASING 700-300 MB QVECTOR
CONV AND LOW LEVEL CONV NEAR THE TROUGH. IN ADDITION...SOME LAKE
ENHANCED SHOWERS MAY DEVELOP OVERNIGHT AS 850 MB TEMPS DROP TO AROUND
1C WITH NNW LOW CYCLONIC FLOW INCREASING. SO...CHANCE POPS WERE
MAINTAINED OVER MOST OF THE CWA TONIGHT EVEN IF ONLY INTERMITTENT
PERIODS OF RAIN DEVELOP.
MONDAY...THE REMAINING SYNOPTIC AND LAKE ENHANCED PCPN OVER THE EAST
IS EXPECTED TO DIMINISH DURING THE MORNING AS THE MID LEVEL QVECTOR
CONV FORCING AND DEEPER MOISTURE DEPART TO THE EAST.
OTHERWISE...GRADUAL CLEARING AND SOME SUNSHINE DURING THE AFTERNOON
WILL BRING TEMPS AGAIN TO NEAR SEASONAL NORMALS IN THE UPPER 50S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 409 PM EDT SUN OCT 6 2013
QUIETER WEATHER WILL REPLACE THE UNSETTLED ACTIVITY OF THIS PAST
WEEK STARTING MONDAY NIGHT. A 500MB RIDGE BUILDS ACROSS THE NORTHERN
PLAINS BY 00Z TUESDAY...AND CONTINUES EASTWARD THROUGHOUT THE
FORECAST PERIOD. SURFACE HIGH PRESSURE EXPANDS INTO THE GREAT LAKES
DURING THE DAY TUESDAY...AND GRADUALLY CENTERS ITSELF OVER THE LOWER
LAKES THROUGH FRIDAY AFTERNOON. THE ECMWF/GFS HAVE 925 MB TEMPS UP
TO 14-15C FOR WEDNESDAY-FRIDAY AFTERNOON OUT WEST...WHICH PUTS HIGHS
ROUGHLY IN THE UPPER 60S/NEAR 70. FOR THE REST OF THE AREA...EXPECT
LOW TO MID 60S. BUMPED UP WINDS FOR TUESDAY AND WEDNESDAY TO ACCOUNT
FOR TIGHTENING PRESSURE GRADIENT ACROSS UPPER MICHIGAN ASSOCIATED
WITH THE SURFACE LOW MOVING JUST NORTH OF LAKE SUPERIOR AND HIGH
PRESSURE CENTERED OVER THE LOWER GREAT LAKES. THOUGH SOUTHERLY WINDS
MAY GUST UP TO 20 KTS AND TEMPS WILL BE CLOSE TO 70...AFTERNOON RH
WILL BE IN THE 35-40 PERCENT RANGE SO DO NOT EXPECT ANY FIRE WX
CONCERNS.
FRIDAY NIGHT INTO SUNDAY...A NEGATIVELY TILTED 500MB
TROUGH/POSSIBLE CUT OFF LOW WILL DIVE INTO THE PLAINS. THIS WILL
PROVIDE THE NEXT CHANCES FOR PRECIPITATION ACROSS UPPER MICHIGAN.
RECENT MODEL RUNS HAVE THE SFC LOW PRESSURE SYSTEM MOVING NORTHEAST
INTO HUDSON BAY BY SUNDAY MORNING...BRINGING A COLD FRONT ACROSS
UPPER MI. BOTH THE GFS/ECMWF HAVE THIS...THOUGH THERE ARE
DIFFERENCES IN TIMING...WITH THE GFS BRINGING THE FRONT THROUGH
FRIDAY NIGHT AND THE ECMWF BRINGING IT THROUGH SATURDAY AFTERNOON.
EVEN MORE SIGNIFICANT DIFFERENCES BETWEEN THE GFS/ECMWF SHOW UP ON
SUNDAY AS ANOTHER TROUGH APPROACHES FROM THE WEST. THE GFS BRINGS
SATURDAYS FRONT OUT OF UPPER MICHIGAN BY 12Z SUNDAY...AND THE DRY
SLOT MOVES IN OVERHEAD WHICH ENDS PRECIPITATION. BY 00Z MONDAY IT
HAS A SHORTWAVE SLIDING INTO THE DAKOTAS AND PRECIPITATION MOVING
INTO WESTERN LAKE SUPERIOR OUT AHEAD OF IT. THE ECMWF KEEPS A
STRONGER RIDGE OVER THE LOWER LAKES AND NEW ENGLAND STATES FOR
SATURDAY AND SUNDAY...SO THE PROGRESSION OF THE FRONT ON SATURDAY IS
SLOWER THAN THE GFS...AND IT STALLS OUT OVER CENTRAL/EASTERN UPPER
MICHIGAN FOR SUNDAY. OVERALL...GENERAL CHANCE-SLIGHT CHANCE POPS ARE
IN THE FORECAST FOR THESE DAYS. IT SEEMS BOTH MODELS HAVE BEEN
FAIRLY INCONSISTENT FROM RUN TO RUN ON THE WEEKEND SOLUTION...SO
WILL NOT GET CUTE WITH TIMING UNTIL THINGS IRON THEMSELVES OUT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 755 PM EDT SUN OCT 6 2013
LOW-LEVEL MOISTURE WRAPPING BACK INTO THE AREA BEHIND EXITING LOW
PRES SHOULD RESULT IN IFR CONDITIONS THIS EVENING AT KIWD...LIFR AT
KCMX AND MVFR FALLING TO IFR THIS EVENING AT KSAW. EXPECT A FEW
-SHRA AS WELL. PER SATELLITE/SFC OB TRENDS...EXPECT IMPROVEMENT TO
MVFR FROM NW TO SE LATE EVENING AND OVERNIGHT...AND LOW CLOUDS MAY
EVEN SCATTER OUT LATE AT KIWD/KCMX. MVFR CIGS SHOULD RETURN FOR A
TIME MON MORNING AT KIWD/KCMX AS DAYTIME HEATING GENERATES STRATOCU.
VFR CONDITIONS SHOULD THEN DEVELOP AT KIWD/KCMX EARLY IN THE AFTN
AND AT KSAW AROUND MID AFTN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT SUN OCT 6 2013
NNW WINDS AT 20 TO 30 KNOTS ARE EXPECTED TO DEVELOP LATE TONIGHT
INTO MONDAY AS THE LOW PRES TROUGH OVER THE UPPER LAKES MOVES OFF TO
THE EAST AND THE GRADIENT TIGHTENS ACROSS THE AREA. A HIGH PRESSURE
RIDGE WILL THEN BUILD EAST INTO THE UPPER GREAT LAKES FOR MONDAY
NIGHT WITH WINDS DROPPING BELOW 25KTS. AT THIS HIGH SHIFTS EAST ON
WEDNESDAY...SOUTHERLY FLOW WILL DEVELOP OVER THE UPPER GREAT LAKES AS
A LOW PRESSURE SYSTEM MOVES THROUGH CENTRAL CANADA. AT THIS
TIME...THE SOUTHERLY FLOW LOOKS TO STAY BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EDT SUN OCT 6 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 409 PM EDT SUN OCT 6 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE OVER THE WRN CONUS AND
A TROUGH FROM HUDSON BAY INTO NRN ONTARIO. THE PERSISTENT MID/UPPER
LEVEL LOW HAD EDGED EASTWARD INTO ERN IA. AT THE SFC...LOW PRES WAS
LOCATED OVER S CNTRL LAKE SUPERIOR WITH A COLD FRONT INTO CNTRL
LOWER MI AND A TROUGH TO THE SW INTO SE MN. RAIN ASSOCIATED WITH A
WEAK SHORTWAVE IN THE WARM CONVEYOR AHEAD OF THE COLD FRONT WAS
LIFTING NNE THROUGH ERN CWA. OTHERWISE...RADAR INDICATED ONLY VERY
WEAK RETURNS OVER THE WEST WITH SOME SPRINKLES OR DRIZZLE. FARTHER
WEST...A NARROW BAND OF RAIN TO NEAR DLH WAS ASSOCIATED WITH THE MID
LEVEL DEFORMATION/FGEN BAND/TROWAL ON THE NRN FLANK OF THE MID LEVEL
LOW. VIS LOOP SHOWED CLEARING OVER SRN UPPER MI WITH THE ADVANCING
DRY SLOT.
TONIGHT...MODELS SUGGEST THAT THE NE MN RAIN BAND WILL CONTINUE TO
SLOWLY SPREAD INTO WEST UPPER MI THIS EVENING AND GRADUALLY SHRINK
OVERNIGHT...PER FCST 310KE SURFACE. THERE MAY ALSO BE A FEW LIGHT
SHOWERS THROUGH CNTRL UPPER MI THIS EVENING AS THE DRY SLOT AREA
GIVES WAY TO INCREASING CLOUDS WITH INCREASING 700-300 MB QVECTOR
CONV AND LOW LEVEL CONV NEAR THE TROUGH. IN ADDITION...SOME LAKE
ENHANCED SHOWERS MAY DEVELOP OVERNIGHT AS 850 MB TEMPS DROP TO AROUND
1C WITH NNW LOW CYCLONIC FLOW INCREASING. SO...CHANCE POPS WERE
MAINTAINED OVER MOST OF THE CWA TONIGHT EVEN IF ONLY INTERMITTENT
PERIODS OF RAIN DEVELOP.
MONDAY...THE REMAINING SYNOPTIC AND LAKE ENHANCED PCPN OVER THE EAST
IS EXPECTED TO DIMINISH DURING THE MORNING AS THE MID LEVEL QVECTOR
CONV FORCING AND DEEPER MOISTURE DEPART TO THE EAST.
OTHERWISE...GRADUAL CLEARING AND SOME SUNSHINE DURING THE AFTERNOON
WILL BRING TEMPS AGAIN TO NEAR SEASONAL NORMALS IN THE UPPER 50S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 409 PM EDT SUN OCT 6 2013
QUIETER WEATHER WILL REPLACE THE UNSETTLED ACTIVITY OF THIS PAST
WEEK STARTING MONDAY NIGHT. A 500MB RIDGE BUILDS ACROSS THE NORTHERN
PLAINS BY 00Z TUESDAY...AND CONTINUES EASTWARD THROUGHOUT THE
FORECAST PERIOD. SURFACE HIGH PRESSURE EXPANDS INTO THE GREAT LAKES
DURING THE DAY TUESDAY...AND GRADUALLY CENTERS ITSELF OVER THE LOWER
LAKES THROUGH FRIDAY AFTERNOON. THE ECMWF/GFS HAVE 925 MB TEMPS UP
TO 14-15C FOR WEDNESDAY-FRIDAY AFTERNOON OUT WEST...WHICH PUTS HIGHS
ROUGHLY IN THE UPPER 60S/NEAR 70. FOR THE REST OF THE AREA...EXPECT
LOW TO MID 60S. BUMPED UP WINDS FOR TUESDAY AND WEDNESDAY TO ACCOUNT
FOR TIGHTENING PRESSURE GRADIENT ACROSS UPPER MICHIGAN ASSOCIATED
WITH THE SURFACE LOW MOVING JUST NORTH OF LAKE SUPERIOR AND HIGH
PRESSURE CENTERED OVER THE LOWER GREAT LAKES. THOUGH SOUTHERLY WINDS
MAY GUST UP TO 20 KTS AND TEMPS WILL BE CLOSE TO 70...AFTERNOON RH
WILL BE IN THE 35-40 PERCENT RANGE SO DO NOT EXPECT ANY FIRE WX
CONCERNS.
FRIDAY NIGHT INTO SUNDAY...A NEGATIVELY TILTED 500MB
TROUGH/POSSIBLE CUT OFF LOW WILL DIVE INTO THE PLAINS. THIS WILL
PROVIDE THE NEXT CHANCES FOR PRECIPITATION ACROSS UPPER MICHIGAN.
RECENT MODEL RUNS HAVE THE SFC LOW PRESSURE SYSTEM MOVING NORTHEAST
INTO HUDSON BAY BY SUNDAY MORNING...BRINGING A COLD FRONT ACROSS
UPPER MI. BOTH THE GFS/ECMWF HAVE THIS...THOUGH THERE ARE
DIFFERENCES IN TIMING...WITH THE GFS BRINGING THE FRONT THROUGH
FRIDAY NIGHT AND THE ECMWF BRINGING IT THROUGH SATURDAY AFTERNOON.
EVEN MORE SIGNIFICANT DIFFERENCES BETWEEN THE GFS/ECMWF SHOW UP ON
SUNDAY AS ANOTHER TROUGH APPROACHES FROM THE WEST. THE GFS BRINGS
SATURDAYS FRONT OUT OF UPPER MICHIGAN BY 12Z SUNDAY...AND THE DRY
SLOT MOVES IN OVERHEAD WHICH ENDS PRECIPITATION. BY 00Z MONDAY IT
HAS A SHORTWAVE SLIDING INTO THE DAKOTAS AND PRECIPITATION MOVING
INTO WESTERN LAKE SUPERIOR OUT AHEAD OF IT. THE ECMWF KEEPS A
STRONGER RIDGE OVER THE LOWER LAKES AND NEW ENGLAND STATES FOR
SATURDAY AND SUNDAY...SO THE PROGRESSION OF THE FRONT ON SATURDAY IS
SLOWER THAN THE GFS...AND IT STALLS OUT OVER CENTRAL/EASTERN UPPER
MICHIGAN FOR SUNDAY. OVERALL...GENERAL CHANCE-SLIGHT CHANCE POPS ARE
IN THE FORECAST FOR THESE DAYS. IT SEEMS BOTH MODELS HAVE BEEN
FAIRLY INCONSISTENT FROM RUN TO RUN ON THE WEEKEND SOLUTION...SO
WILL NOT GET CUTE WITH TIMING UNTIL THINGS IRON THEMSELVES OUT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 409 PM EDT SUN OCT 6 2013
IFR CONDITIONS ARE EXPECTED TO CONTINUE AT CMX WITH ABUNDANT LOW
LEVEL MOISTURE OVER THE REGION AND UPSLOPE W TO NW FLOW. MVFR CIGS
ARE EXPECTED THIS AFTERNOON AT IWD/SAW AS DRIER MOVES INTO THE AREA
AND GREATER DAYTIME MIXING OCCURS. CIGS MAY THEN FALL BACK AGAIN IN
THE LATE AFTERNOON AND EVENING AS LOW-LEVEL MOISTURE WRAPS BACK INTO
THE AREA BEHIND SFC LOW MOVING EXITING TO THE E OF THE AREA. VFR
CONDITIONS WILL MOVE IN WITH DRIER AIR INTO IWD AND CMX LATE TONIGHT
AND INTO SAW BY MID MON MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT SUN OCT 6 2013
NNW WINDS AT 20 TO 30 KNOTS ARE EXPECTED TO DEVELOP LATE TONIGHT
INTO MONDAY AS THE LOW PRES TROUGH OVER THE UPPER LAKES MOVES OFF TO
THE EAST AND THE GRADIENT TIGHTENS ACROSS THE AREA. A HIGH PRESSURE
RIDGE WILL THEN BUILD EAST INTO THE UPPER GREAT LAKES FOR MONDAY
NIGHT WITH WINDS DROPPING BELOW 25KTS. AT THIS HIGH SHIFTS EAST ON
WEDNESDAY...SOUTHERLY FLOW WILL DEVELOP OVER THE UPPER GREAT LAKES AS
A LOW PRESSURE SYSTEM MOVES THROUGH CENTRAL CANADA. AT THIS
TIME...THE SOUTHERLY FLOW LOOKS TO STAY BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
1023 PM CDT SUN OCT 6 2013
.UPDATE...
ISSUED AT 1017 PM CDT SUN OCT 6 2013
SOME PATCHY RADIATIONAL FOG HAS DEVELOPED OVER THE ARROWHEAD OF
MINNESOTA. DEWPOINT DEPRESSIONS AROUND SUNSET WERE LESS THAN 10
DEGREES FOR MOST OF THE FORECAST AREA...EXCEPT FOR THE FAR
NORTHWEST COUNTIES. THEN...AS OF 9PM SOME DRIER AIR HAD FILTERED
IN FROM THE NORTHWEST AND THE BETTER DEWPOINT DEPRESSIONS REMAIN
IN THE SAME AREAS. HAVE PUT IN PATCHY TO AREAS OF FOG INTO THE
GRIDS FOR THE REST OF THE NIGHT FOR A FAIRLY LARGE PORTION OF THE
FORECAST AREA...AND AM ALSO IN THE PROCESS OF UPDATING TERMINAL
FORECASTS AS WELL.
UPDATE ISSUED AT 641 PM CDT SUN OCT 6 2013
SOME MINOR ADJUSMENTS TO EVENING FORECAST...MAINLY FOR CLOUD
TRENDS AND TEMPERATURES FOR THE NEXT FEW HOURS. HAVE SOME CONCERNS
FOR THE RECENT RAINFALL SETTING UP GOOD PRECONDITIONS FOR
FOG...WITH PLENTY OF LOW LEVEL MOISTURE AND LIGHT NORTHWEST WINDS.
CURRENTLY GUIDANCE INDICATES NO FOG IS LIKELY TO FORM. EXPERIENCE
BEGS TO DIFFER. FOR NOW WILL MONITOR LOW LEVEL MOISTURE
PARAMETERS AND WINDS...AND RE-EVALUATE HERE BEFORE 10 PM.
ALSO UPDATED AVIATION SECTION BELOW.
&&
.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 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 641 PM CDT SUN OCT 6 2013
LIFR CIGS AT KDLH AND KHYR TO CLEAR BY 03Z THIS EVENING...LEAVING
VFR CONDITIONS AND LIGHT NORTHWEST WINDS AT THE TERMINALS THE REST
OF THE NIGHT. HAVE CONCERNS FOR FOG POTENTIAL AS MENTIONED IN
UPDATE SECTION ABOVE...AND WILL MAKE ADJUSTMENTS AS NEEDED. VFR
CONDITIONS TO CONTINUE THROUGH TOMORROW...WITH WINDS REMAINING
NORTHWEST AT OR BELOW 10 KTS THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 36 60 42 67 / 10 0 0 0
INL 35 61 41 69 / 0 0 0 0
BRD 38 64 44 72 / 0 0 0 0
HYR 36 61 39 70 / 30 10 0 0
ASX 38 61 43 70 / 30 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...MELDE
LONG TERM...GRANING
AVIATION...LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
644 PM CDT SUN OCT 6 2013
.UPDATE...
ISSUED AT 641 PM CDT SUN OCT 6 2013
SOME MINOR ADJUSMENTS TO EVENING FORECAST...MAINLY FOR CLOUD
TRENDS AND TEMPERATURES FOR THE NEXT FEW HOURS. HAVE SOME CONCERNS
FOR THE RECENT RAINFALL SETTING UP GOOD PRECONDITIONS FOR
FOG...WITH PLENTY OF LOW LEVEL MOISTURE AND LIGHT NORTHWEST WINDS.
CURRENTLY GUIDANCE INDICATES NO FOG IS LIKELY TO FORM. EXPERIENCE
BEGS TO DIFFER. FOR NOW WILL MONITOR LOW LEVEL MOISTURE
PARAMETERS AND WINDS...AND RE-EVALUATE HERE BEFORE 10 PM.
ALSO UPDATED AVIATION SECTION BELOW.
&&
.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 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 641 PM CDT SUN OCT 6 2013
LIFR CIGS AT KDLH AND KHYR TO CLEAR BY 03Z THIS EVENING...LEAVING
VFR CONDITIONS AND LIGHT NORTHWEST WINDS AT THE TERMINALS THE REST
OF THE NIGHT. HAVE CONCERNS FOR FOG POTENTIAL AS MENTIONED IN
UPDATE SECTION ABOVE...AND WILL MAKE ADJUSTMENTS AS NEEDED. VFR
CONDITIONS TO CONTINUE THROUGH TOMORROW...WITH WINDS REMAINING
NORTHWEST AT OR BELOW 10 KTS THROUGH THE PERIOD.
&&
.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 / 30 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...MELDE
LONG TERM...GRANING
AVIATION...LE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
353 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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1239 PM CDT SAT OCT 5 2013
LOW CONFIDENCE WITH CIG FORECAST IN TAFS. DRYING ASSOCIATED WITH
OCCLUDED LOW OVER SE SODAK HAS BEEN SLOWLY SPREADING NORTH/EAST.
THE RAP ALONG WITH THE GFS/NAM TAKES VFR CONDITIONS ACROSS ALL
TERMINALS FOR A TIME. THERE IS LOTS OF DISAGREEMENT WITH WHEN MVFR
CIGS WILL DROP BACK SOUTH AND EAST THIS EVENING...WITH RAP BEING
THE MOST AGGRESSIVE WITH BRINGING MVFR OR LOWER CIGS BACK AND
THE GFS/NAM SIGNIFICANTLY SLOWER. THESE TAFS WERE WRITTEN MORE
TOWARD THE GFS/NAM IDEA FOR CIGS. CONFIDENCE INCREASING IN AN AREA
OF SHRA DEVELOPING SHORTLY FROM STC DOWN TO MKT ON EAST FOR THE
AFTERNOON. THE HRRR ALONG WITH THE HOPWRF HAVE BOTH BEEN DEPICTING
THIS ALL MORNING AND WITH MID LEVEL CLOUDS EXPANDING ON SATELLITE
ALONG WITH RETURNS SHOWING UP ON RADAR IN SOUTH CENTRAL MN...SIDED
CLOSELY WITH THE HRRR IN BRINGING PRECIP BACK TO ALL BUT RWF. THE
LOW OFF TO THE WEST WILL DRIFT ACROSS MN TONIGHT...WITH WINDS
BECOMING LIGHT AND VRB AS A RESULT. WITH THE LIGHT WINDS...
ANYWHERE THAT REMAINS RELATIVELY CLEAR TONIGHT WILL HAVE TO THREAT
FOR DENSE FOG. AT THE MOMENT...THE MOST LIKELY PLACE FOR THAT TO
HAPPEN WOULD BE OVER WRN WI.
KMSP...TOUGH TO PIN DOWN THE CIGS FOR THIS FORECAST...AS THE 12Z
NAM/GFS WOULD BOTH INDICATE THAT CIGS WILL REMAIN VFR UNTIL LATE
SUNDAY AFTERNOON. CONFIDENCE HIGH IN ANOTHER ROUND OF SHOWERS
MOVING ACROSS THE FIELD BETWEEN 20Z AND 01Z PER THE HRRR AND
HOPWRF...THOUGH CONFIDENCE LOWER IN CIGS COMING BACK DOWN AS LOW
AS THEY ARE CURRENTLY FORECAST TO BE...MAY ONLY COME AS LOW AS 6K
FT WITH THE PRECIP. OPTIMISTIC CIG FORECAST TOMORROW BASED ON THE
GFS/NAM...BUT THE RAP SHOWS MVFR CIGS RETURNING TO MSP AROUND
09Z. IF THE CIGS DO COME IN BEFORE 12Z SUNDAY...THERE IS A GOOD
CHANCE THEY WILL COME IN BELOW 017.
/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...MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
320 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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1232 PM CDT SAT OCT 5 2013
IFR AND MVFR CIGS/VSBYS WILL PERSIST THROUGH TODAY AND MOST OF
TONIGHT BEFORE GRADUAL IMPROVEMENT IS SEEN BY LATE SUNDAY MORNING
ACROSS THE WRN TERMINALS. LIGHT SCATTERED RAIN SHOWERS ARE
EXPECTED THIS AFTERNOON WITH MORE WIDESPREAD HEAVIER SHOWERS
POSSIBLE THIS EVENING...AFTER 23/00Z...LASTING THROUGH 05/06Z.
VSBYS WILL LOWER IN THE STRONGER SHOWERS...WITH POSSIBLY PATCHY
FOG AROUND DLH AND HYR TONIGHT. GUSTY NE WINDS WILL SLOWLY
DIMINISH IN INTENSITY AND BACK TO THE NORTH TONIGHT.
&&
.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...BJT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
111 PM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 1034 AM CDT SAT OCT 5 2013
A TRICKY FORECAST TO SAY THE LEAST FOR TODAY. DRY SLOT HAS MOVED
IN BEHIND THE OCCLUDED FRONT THIS MORNING...WITH PARTIAL CLEARING
OF SKIES SEEN WEST AND SOUTH OF THE TWIN CITIES. AFTER MAKING GOOD
PROGRESS OVERNIGHT...THIS CLEARING HAS PUT ON THE BREAKS AS THE
LOW OVER SE SODAK HAS STARTED TO DRIFT ESE. THIS WILL KEEP THE
CLEARING FROM MAKING IT MUCH FARTHER NORTH...BUT IT WILL CONTINUE
TO SLOWLY CRAWL TOWARD THE EAST TODAY.
OF COURSE AS THIS IS GOING ON THE BIGGEST CHANGE TO THE FORECAST
IS THE ADDITION OF SHOWERS THIS AFTERNOON FROM MANKATO TO ST.
CLOUD ON EAST. THE HRRR HAS BEEN SHOWING THIS AREA OF SHOWERS
DEVELOPING BACK TO THE WEST FOR SEVERAL RUNS NOW. LOOKING AT THE
RAP...THIS IS IN RESPONSE TO A STRONG BAND OF FGEN COMING UP FROM
IOWA IN THE H7-H5 LAYER. LOOKING DOWN TO THE SOUTHWEST ON
SATELLITE...YOU CAN SEE THIS AREA OF PRECIP STARTING TO TAKE
SHAPE FROM ERN KANSAS UP INTO WRN IOWA. BOOSTED POPS UP TO AROUND
50 PERCENT BACK TO THE CITIES THIS AFTERNOON...BUT IF THE HRRR IS
CORRECT...MAY NEED TO BOOST THEM UP SIGNIFICANTLY IN THE NEAR
FUTURE...ESPECIALLY CONSIDERING ALL 4 MEMBERS OF THE 05.09 HOPWRF
SHOW SOMETHING SIMILAR HAPPENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CDT SAT OCT 5 2013
THE POTENCY OF THIS EARLY FALL SYSTEM WAS AGAIN ON DISPLAY LAST
NIGHT WITH STRONG TO SEVERE STORMS IN THE WARM SECTOR AND A RAGING
BLIZZARD IN WESTERN SOUTH DAKOTA. FURTHERMORE...THE SYSTEM HAS
BEEN OCCLUDED FOR 12-18 HOURS NOW AND WE STILL SAW A 1-2 MB MSLP
PRESSURE DROP OVERNIGHT. THE TROWAL IS CREATING A HOME RUN HITTING
DEFORMATION BAND FROM NORTHERN MN TO ND TO SD. IN FACT...THE
PRECIP SHIELD ALONG THE COLD CONVEYOR BELT ACTUALLY EXTENDS ALL
THE WAY FROM WYOMING TO MICHIGAN...AND THUNDERSTORMS ALONG THE
COLD FRONT EXTEND FROM MICHIGAN TO TEXAS. NOT A SMALL SYSTEM BY
ANY MEANS.
THE FORECAST AREA WILL FIND ITSELF IN THE DRY SLOT MOST OF THE DAY
TODAY AND ALSO TONIGHT TO SOME DEGREE. HOWEVER SOME DRIZZLE IS
POSSIBLE AND THE CLOUDS SHOULD LARGELY STAY IN TACT. THE OCCLUDED
BOUNDARY ISN`T GOING ANYWHERE...ESPECIALLY FOR CENTRAL MN/WI.
SOUTHERN PORTIONS OF THE FORECAST AREA /THAT`S RIGHT...SOUTHERN/
ARE CLOSER TO THE COLDER AND DRIER AIR...SO THERE IS A BETTER
CHANCE OF AT LEAST PARTIAL CLEARING TODAY IN SOUTHERN MN. MUCH
COLDER AIR ALOFT ARRIVES TONIGHT...SO THE STRATUS WON`T BE FAR
BEHIND EVEN IF THERE IS CLEARING DURING THE DAY TODAY. THE 00-06Z
GUIDANCE IS TOO FAR SOUTH WITH THE DEFORMATION PRECIP BAND THIS
MORNING...AS THE FORECAST AREA IS VIRTUALLY PRECIP FREE. IT`S ALSO
NOT DEEP ENOUGH WITH THE SURFACE LOW. TRIED TO KEEP THE POPS TODAY
ON THE OUTER EDGES OF THE FORECAST AREA TO COUNTER THIS AND ALSO
TO STAY CLOSE TO SURROUND FORECAST OFFICES. OTHERWISE...WINDS WILL
FALL OFF AS THE LOW SLOWLY FILLS AND MOVES OVERHEAD. IF THE CLOUDS
CLEAR ANYWHERE TONIGHT...FOG COULD BE A PROBLEM...TOOK THE SIDE OF
LOW STRATUS FOR NOW. NEAR STEADY TEMPERATURE TODAY SO MADE LITTLE
ADJUSTMENT TO THE PREVIOUS FORECAST. WE ADJUSTED DEWPOINTS BY
KEEPING SLIGHTLY HIGHER VALUES NEAR THE FRONT AND COOLER VALUES
CLOSER TO THE DRY SLOT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 342 AM CDT SAT OCT 5 2013
THE SFC LOW FROM THE POTENT/DEEP SYSTEM AFFECTING THE REGION WILL
SHIFT INTO WI BY DAYBREAK SUN MRNG WHILE THE LOW PRES CENTER ALOFT
WILL SHIFT SE INTO NRN IA. AS THESE TWO LOWS MOVE EAST IN TANDEM
SLOWLY DURG THE DAY ON SUN...THE DRY SLOT OVER MUCH OF THE AREA
WILL FILL BACK IN WITH DEEPER MOISTURE WRAPPING AROUND THE UPPER
LEVEL LOW. COLD ALOFT COMBINED WITH LOW LEVEL WINDS SHIFTING TO A
MORE NLY DIRECTION WILL AID IN KEEPING LOW CLOUDS IN PLACE FOR
MUCH OF THE DAY...ALONG WITH A DRIZZLE/RAIN SCENARIO FOR SENSIBLE
WX. THE UPPER LOW WILL SHIFT ESE INTO CENTRAL IL BY MON
MRNG...DRAGGING MUCH OF THE MOISTURE WITH IT BUT THERE WILL STILL
BE A CHC FOR LINGERING SHOWERS IN WRN WI ON MON WHILE SRN/CENTRAL
MN STARTS TO CLEAR OUT. CONDS WILL GRADUALLY IMPROVE DURG THE DAY
ON MON AS HIGH PRES FROM SW CANADA DROPS IN. DESPITE THE COOL
ORIGIN OF THIS AIRMASS...IT WILL BE QUICKLY MODIFIED BY AN UPPER
LEVEL RIDGE THAT WITH INCRG H5 HEIGHTS WILL SPELL A WARMING TREND
ALONG WITH A PROLONGED DRYING-OUT PERIOD FOR THE AREA. DRY WX IS
FORECAST MON THRU THU WITH HIGHS RISING BACK INTO THE MID 70S.
MODELS CONTINUE TO ADVERTISE ANOTHER POTENT SYNOPTIC-SCALE LOW
PRES SYSTEM TO DEVELOP IN THE LEE OF THE ROCKIES THU NIGHT INTO
FRI MORNING...WITH IT QUICKLY MOVG NEWD INTO THE DAKOTAS FRI. THIS
MAY ALLOW FOR SOME MID-TO-LATE DAY SHWRS/TSTMS OVER WRN MN ON FRI
AS THIS SYSTEM ADVANCES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1239 PM CDT SAT OCT 5 2013
LOW CONFIDENCE WITH CIG FORECAST IN TAFS. DRYING ASSOCIATED WITH
OCCLUDED LOW OVER SE SODAK HAS BEEN SLOWLY SPREADING NORTH/EAST.
THE RAP ALONG WITH THE GFS/NAM TAKES VFR CONDITIONS ACROSS ALL
TERMINALS FOR A TIME. THERE IS LOTS OF DISAGREEMENT WITH WHEN MVFR
CIGS WILL DROP BACK SOUTH AND EAST THIS EVENING...WITH RAP BEING
THE MOST AGGRESSIVE WITH BRINGING MVFR OR LOWER CIGS BACK AND
THE GFS/NAM SIGNIFICANTLY SLOWER. THESE TAFS WERE WRITTEN MORE
TOWARD THE GFS/NAM IDEA FOR CIGS. CONFIDENCE INCREASING IN AN AREA
OF SHRA DEVELOPING SHORTLY FROM STC DOWN TO MKT ON EAST FOR THE
AFTERNOON. THE HRRR ALONG WITH THE HOPWRF HAVE BOTH BEEN DEPICTING
THIS ALL MORNING AND WITH MID LEVEL CLOUDS EXPANDING ON SATELLITE
ALONG WITH RETURNS SHOWING UP ON RADAR IN SOUTH CENTRAL MN...SIDED
CLOSELY WITH THE HRRR IN BRINGING PRECIP BACK TO ALL BUT RWF. THE
LOW OFF TO THE WEST WILL DRIFT ACROSS MN TONIGHT...WITH WINDS
BECOMING LIGHT AND VRB AS A RESULT. WITH THE LIGHT WINDS...
ANYWHERE THAT REMAINS RELATIVELY CLEAR TONIGHT WILL HAVE TO THREAT
FOR DENSE FOG. AT THE MOMENT...THE MOST LIKELY PLACE FOR THAT TO
HAPPEN WOULD BE OVER WRN WI.
KMSP...TOUGH TO PIN DOWN THE CIGS FOR THIS FORECAST...AS THE 12Z
NAM/GFS WOULD BOTH INDICATE THAT CIGS WILL REMAIN VFR UNTIL LATE
SUNDAY AFTERNOON. CONFIDENCE HIGH IN ANOTHER ROUND OF SHOWERS
MOVING ACROSS THE FIELD BETWEEN 20Z AND 01Z PER THE HRRR AND
HOPWRF...THOUGH CONFIDENCE LOWER IN CIGS COMING BACK DOWN AS LOW
AS THEY ARE CURRENTLY FORECAST TO BE...MAY ONLY COME AS LOW AS 6K
FT WITH THE PRECIP. OPTIMISTIC CIG FORECAST TOMORROW BASED ON THE
GFS/NAM...BUT THE RAP SHOWS MVFR CIGS RETURNING TO MSP AROUND
09Z. IF THE CIGS DO COME IN BEFORE 12Z SUNDAY...THERE IS A GOOD
CHANCE THEY WILL COME IN BELOW 017.
/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.
&&
$$
UPDATE...MPG
SHORT TERM...CLF
LONG TERM...JPC
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1232 PM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 1232 PM CDT SAT OCT 5 2013
UPDATED FOR AVIATION DISCUSSION.
UPDATE ISSUED AT 1029 AM CDT SAT OCT 5 2013
THE SURFACE LOW WAS LOCATED IN SOUTHEAST SOUTH DAKOTA AS OF 15Z
WITH AN OCCLUDED FRONT EXTENDING FROM THIS LOW ACROSS PORTIONS OF
S-C MINNESOTA INTO FAR SOUTHWEST WISCONSIN. 925MB BOUNDARY IS IN
NEARLY THE SAME LOCATION WITH HIGHER THETA-E AIR NORTH AND EAST OF THE
BOUNDARY. THIS FRONT MARKED A CLEARING LINE WITH DRY CONDITIONS
BEHIND IT OVER MUCH OF SOUTHERN MINNESOTA. LIGHT RAIN/DRIZZLE
CONTINUED OVER PORTIONS OF THE NORTHLAND THIS MORNING...BUT WASN`T
REAL WIDESPREAD. WE TRIMMED BACK SOME ON POPS THROUGH MID
AFTERNOON BUT MAY HAVE TO FURTHER AS SEVERAL OBSERVATIONS WERE NOT
REPORTING ANY RAIN AS OF 15Z. WE DO EXPECT AN INCREASE IN COVERAGE
LATER THIS AFTERNOON AS THE STACKED LOW PRESSURE SYSTEM MOVES
FURTHER EAST. THE LATEST HRRR WAS DOING A DECENT JOB DEPICTING THE
LIGHT RAIN THIS MORNING AND SHOWS COVERAGE INCREASING QUITE A BIT
MID TO LATE AFTERNOON ACROSS THE SOUTHERN THIRD...THEN FURTHER
NORTH THIS EVENING. THE 12Z NAM SUPPORTS THE HRRR BUT STILL MAY BE
OVERDONE WITH IT`S QPF. AREAS OF DRIZZLE WILL ALSO OCCUR AROUND
LAKE SUPERIOR. WE CONTINUE TO MONITOR RADAR TRENDS AND LATEST
MODEL OUTPUT AND ADJUST AS NEEDED.
IT REMAINS WINDY AROUND LAKE SUPERIOR...ESPECIALLY FROM SILVER BAY
TO THE TWIN PORTS AND ALONG THE BAYFIELD PENINSULA. KDLH WAS
GUSTING TO 42 MPH AS OF THE 1008 AM OBSERVATION AND TO 46 MPH ON
PARK POINT. WE`LL KEEP THE WIND ADVISORY GOING AS IS FOR NOW. WE
MAY NEED TO EXTEND IT FOR THE TWIN PORTS AREA TO TWO HARBORS/SILVER
BAY. THE WIND WASN`T AS STRONG ACROSS BAYFIELD/ASHLAND COUNTIES
BUT SOME HIGHER GUSTS WILL REMAIN POSSIBLE THERE AS WELL.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 410 AM CDT SAT OCT 5 2013
AT 4 AM...RAIN CONTINUED TO MOVE NORTHWARD ACROSS THE CWA. THE
MASSIVE LOW PRESSURE SYSTEM WAS LOCATED IN CENTRAL SOUTH
DAKOTA...WITH AN OCCLUDED FRONT STRETCHING EASTWARD THROUGH SW MN.
TEMPERATURES AT 4 AM WERE GENERALLY IN THE MID TO UPPER 40S NORTH
AND LOWER TO MIDDLE 50S SOUTH. STRONG WINDS CONTINUED NEAR LAKE
SUPERIOR...WITH KDYT AND KDLH STILL GUSTING ABOVE 40 MPH. THE RAIN
HAD DIMINISHED CONSIDERABLY ACROSS THE SOUTHERN THIRD OF THE CWA
BUT CONTINUED FROM THE TWIN PORTS NORTHWARD.
THE MAIN FOCUS FOR TODAY THROUGH SUNDAY IS THE EXTENT AND TIMING
OF VARIOUS WAVES OF PRECIPITATION. THE NAM AND THE NSSL AND NCEP
WRF RUNS SEEM TO HAVE A DECENT HANDLE ON THE SITUATION. THEY ALL
BRING A REPRIEVE IN THE RAIN TO THE SOUTHERN CWA...BEFORE
INCREASING AGAIN THIS AFTERNOON. DESPITE SOME BREAKS IN THE
PRECIPITATION...THERE SHOULD BE AREAS OF DRIZZLE AS WELL. WILL
CONTINUE WITH HIGH POPS. A LITTLE CONCERNED WE MAY NEED TO
EVENTUALLY PULL BACK ON POPS IN THE SOUTH...BUT KEPT THEM HIGH DUE
TO THE POTENTIAL FOR DRIZZLE.
RAIN SHOULD BECOME WIDESPREAD AGAIN TONIGHT...AS SURFACE LOW
PRESSURE RE-FORMS OVER WISCONSIN. FOR THAT REASON...WILL CONTINUE
WITH HIGH POPS TONIGHT...AND THEN GRADUALLY DECREASE IN PLACE AS
THE LOW STARTS TO FALL APART ON SUNDAY. WILL CONTINUE POPS
THROUGHOUT THE DAY THOUGH...AS THERE SHOULD BE SOME LINGERING
PRECIPITATION.
WILL CONTINUE WITH THE WIND ADVISORY FOR TODAY DUE TO THE STRONG
EASTERLY WINDS COMING OFF LAKE SUPERIOR.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT OCT 5 2013
ANOMALOUS SFC/MID LVL LOW WILL DRIFT EAST OF REGION BE EARLY MONDAY
AS SPLIT FLOW IN WESTERLIES ALLOWS NRN BRANCH TO DEEPEN OVER REGION.
PRECIP WILL GRADUALLY DIMINISH OVER THE ERN CWA AS CYCLONIC
CIRCULATION LOOSENS ITS GRIP MONDAY. MDLS AGREE THAT A RELATIVELY
QUIET DRY WEATHER PATTERN WILL COMMENCE TUESDAY AND PERSIST THROUGH
THE WEEK. SYNOPTIC PATTERN WILL FEATURE A DEVELOPING LARGE AMPLITUDE
UPPER TROF OVER CALIFORNIA WITH A BROAD UPPER RIDGE ACROSS THE NRN
PLAINS AND THE WRN GT LAKES. A SFC TROUGH WILL BEGIN TO FORM OVER
THE PLAINS AND EXTEND NORTH INTO NWRN MN BY WED EVENING. ALTHOUGH A
WARM ADVECTION REGIME WILL BECOME MORE PRONOUNCED ACROSS THE CWA AT
THIS TIME IT APPEARS THE MORE FAVORABLE LIFT WILL OCCUR TO THE WEST
OF THE REGION THROUGH THURSDAY. CONFIDENCE LOWERS BY FRIDAY AS TO
HOW FAR EAST THE EJECTING MID LVL SYSTEM WILL TRACK DUE TO
DOWNSTREAM UPPER RIDGE OVER MS RIVER VALLEY. WILL KEEP MAINLY DRY
OVER ALL OF CWA THROUGH FRIDAY BEFORE ALLOWING POPS TO RENTER THE
CWA FRIDAY NIGHT. TEMPS WILL RISE ABOVE CLIMO MOST OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1232 PM CDT SAT OCT 5 2013
IFR AND MVFR CIGS/VSBYS WILL PERSIST THROUGH TODAY AND MOST OF
TONIGHT BEFORE GRADUAL IMPROVEMENT IS SEEN BY LATE SUNDAY MORNING
ACROSS THE WRN TERMINALS. LIGHT SCATTERED RAIN SHOWERS ARE
EXPECTED THIS AFTERNOON WITH MORE WIDESPREAD HEAVIER SHOWERS
POSSIBLE THIS EVENING...AFTER 23/00Z...LASTING THROUGH 05/06Z.
VSBYS WILL LOWER IN THE STRONGER SHOWERS...WITH POSSIBLY PATCHY
FOG AROUND DLH AND HYR TONIGHT. GUSTY NE WINDS WILL SLOWLY
DIMINISH IN INTENSITY AND BACK TO THE NORTH TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 47 51 41 / 80 80 60 20
INL 47 39 54 38 / 70 50 40 10
BRD 54 46 53 40 / 80 80 60 20
HYR 57 44 59 41 / 80 80 50 30
ASX 55 49 57 44 / 80 80 60 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ020-037.
WI...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR WIZ001-002.
LS...GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR LSZ141>147.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-140-148.
&&
$$
SHORT TERM...DAP
LONG TERM...CANNON
AVIATION...BJT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1048 AM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 1034 AM CDT SAT OCT 5 2013
A TRICKY FORECAST TO SAY THE LEAST FOR TODAY. DRY SLOT HAS MOVED
IN BEHIND THE OCCLUDED FRONT THIS MORNING...WITH PARTIAL CLEARING
OF SKIES SEEN WEST AND SOUTH OF THE TWIN CITIES. AFTER MAKING GOOD
PROGRESS OVERNIGHT...THIS CLEARING HAS PUT ON THE BREAKS AS THE
LOW OVER SE SODAK HAS STARTED TO DRIFT ESE. THIS WILL KEEP THE
CLEARING FROM MAKING IT MUCH FARTHER NORTH...BUT IT WILL CONTINUE
TO SLOWLY CRAWL TOWARD THE EAST TODAY.
OF COURSE AS THIS IS GOING ON THE BIGGEST CHANGE TO THE FORECAST
IS THE ADDITION OF SHOWERS THIS AFTERNOON FROM MANKATO TO ST.
CLOUD ON EAST. THE HRRR HAS BEEN SHOWING THIS AREA OF SHOWERS
DEVELOPING BACK TO THE WEST FOR SEVERAL RUNS NOW. LOOKING AT THE
RAP...THIS IS IN RESPONSE TO A STRONG BAND OF FGEN COMING UP FROM
IOWA IN THE H7-H5 LAYER. LOOKING DOWN TO THE SOUTHWEST ON
SATELLITE...YOU CAN SEE THIS AREA OF PRECIP STARTING TO TAKE
SHAPE FROM ERN KANSAS UP INTO WRN IOWA. BOOSTED POPS UP TO AROUND
50 PERCENT BACK TO THE CITIES THIS AFTERNOON...BUT IF THE HRRR IS
CORRECT...MAY NEED TO BOOST THEM UP SIGNIFICANTLY IN THE NEAR
FUTURE...ESPECIALLY CONSIDERING ALL 4 MEMBERS OF THE 05.09 HOPWRF
SHOW SOMETHING SIMILAR HAPPENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 342 AM CDT SAT OCT 5 2013
THE POTENCY OF THIS EARLY FALL SYSTEM WAS AGAIN ON DISPLAY LAST
NIGHT WITH STRONG TO SEVERE STORMS IN THE WARM SECTOR AND A RAGING
BLIZZARD IN WESTERN SOUTH DAKOTA. FURTHERMORE...THE SYSTEM HAS
BEEN OCCLUDED FOR 12-18 HOURS NOW AND WE STILL SAW A 1-2 MB MSLP
PRESSURE DROP OVERNIGHT. THE TROWAL IS CREATING A HOME RUN HITTING
DEFORMATION BAND FROM NORTHERN MN TO ND TO SD. IN FACT...THE
PRECIP SHIELD ALONG THE COLD CONVEYOR BELT ACTUALLY EXTENDS ALL
THE WAY FROM WYOMING TO MICHIGAN...AND THUNDERSTORMS ALONG THE
COLD FRONT EXTEND FROM MICHIGAN TO TEXAS. NOT A SMALL SYSTEM BY
ANY MEANS.
THE FORECAST AREA WILL FIND ITSELF IN THE DRY SLOT MOST OF THE DAY
TODAY AND ALSO TONIGHT TO SOME DEGREE. HOWEVER SOME DRIZZLE IS
POSSIBLE AND THE CLOUDS SHOULD LARGELY STAY IN TACT. THE OCCLUDED
BOUNDARY ISN`T GOING ANYWHERE...ESPECIALLY FOR CENTRAL MN/WI.
SOUTHERN PORTIONS OF THE FORECAST AREA /THAT`S RIGHT...SOUTHERN/
ARE CLOSER TO THE COLDER AND DRIER AIR...SO THERE IS A BETTER
CHANCE OF AT LEAST PARTIAL CLEARING TODAY IN SOUTHERN MN. MUCH
COLDER AIR ALOFT ARRIVES TONIGHT...SO THE STRATUS WON`T BE FAR
BEHIND EVEN IF THERE IS CLEARING DURING THE DAY TODAY. THE 00-06Z
GUIDANCE IS TOO FAR SOUTH WITH THE DEFORMATION PRECIP BAND THIS
MORNING...AS THE FORECAST AREA IS VIRTUALLY PRECIP FREE. IT`S ALSO
NOT DEEP ENOUGH WITH THE SURFACE LOW. TRIED TO KEEP THE POPS TODAY
ON THE OUTER EDGES OF THE FORECAST AREA TO COUNTER THIS AND ALSO
TO STAY CLOSE TO SURROUND FORECAST OFFICES. OTHERWISE...WINDS WILL
FALL OFF AS THE LOW SLOWLY FILLS AND MOVES OVERHEAD. IF THE CLOUDS
CLEAR ANYWHERE TONIGHT...FOG COULD BE A PROBLEM...TOOK THE SIDE OF
LOW STRATUS FOR NOW. NEAR STEADY TEMPERATURE TODAY SO MADE LITTLE
ADJUSTMENT TO THE PREVIOUS FORECAST. WE ADJUSTED DEWPOINTS BY
KEEPING SLIGHTLY HIGHER VALUES NEAR THE FRONT AND COOLER VALUES
CLOSER TO THE DRY SLOT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 342 AM CDT SAT OCT 5 2013
THE SFC LOW FROM THE POTENT/DEEP SYSTEM AFFECTING THE REGION WILL
SHIFT INTO WI BY DAYBREAK SUN MRNG WHILE THE LOW PRES CENTER ALOFT
WILL SHIFT SE INTO NRN IA. AS THESE TWO LOWS MOVE EAST IN TANDEM
SLOWLY DURG THE DAY ON SUN...THE DRY SLOT OVER MUCH OF THE AREA
WILL FILL BACK IN WITH DEEPER MOISTURE WRAPPING AROUND THE UPPER
LEVEL LOW. COLD ALOFT COMBINED WITH LOW LEVEL WINDS SHIFTING TO A
MORE NLY DIRECTION WILL AID IN KEEPING LOW CLOUDS IN PLACE FOR
MUCH OF THE DAY...ALONG WITH A DRIZZLE/RAIN SCENARIO FOR SENSIBLE
WX. THE UPPER LOW WILL SHIFT ESE INTO CENTRAL IL BY MON
MRNG...DRAGGING MUCH OF THE MOISTURE WITH IT BUT THERE WILL STILL
BE A CHC FOR LINGERING SHOWERS IN WRN WI ON MON WHILE SRN/CENTRAL
MN STARTS TO CLEAR OUT. CONDS WILL GRADUALLY IMPROVE DURG THE DAY
ON MON AS HIGH PRES FROM SW CANADA DROPS IN. DESPITE THE COOL
ORIGIN OF THIS AIRMASS...IT WILL BE QUICKLY MODIFIED BY AN UPPER
LEVEL RIDGE THAT WITH INCRG H5 HEIGHTS WILL SPELL A WARMING TREND
ALONG WITH A PROLONGED DRYING-OUT PERIOD FOR THE AREA. DRY WX IS
FORECAST MON THRU THU WITH HIGHS RISING BACK INTO THE MID 70S.
MODELS CONTINUE TO ADVERTISE ANOTHER POTENT SYNOPTIC-SCALE LOW
PRES SYSTEM TO DEVELOP IN THE LEE OF THE ROCKIES THU NIGHT INTO
FRI MORNING...WITH IT QUICKLY MOVG NEWD INTO THE DAKOTAS FRI. THIS
MAY ALLOW FOR SOME MID-TO-LATE DAY SHWRS/TSTMS OVER WRN MN ON FRI
AS THIS SYSTEM ADVANCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 623 AM CDT SAT OCT 5 2013
CONDITIONS HAVE GENERALLY BEEN IFR WITH LIFR AT TIMES AND MVFR AT
OTHERS. WE EXPECTED LITTLE CHANGE FOR THE NEXT 2-4 AT THE TAF
SITES AS THE DRIER AIR TAKES ITS TIME TO ARRIVE. HOWEVER...WE DO
EXPECT IMPROVEMENT BY THE LATE MORING OR EARLY AFTERNOON. ITS HARD
TO IMAGINE SKIES GOING MOSTLY SUNNY FOR TOO LONG...AS CU WITH MVFR
CEILINGS SHOULD FILL IN...BUT WE THINK KMSP/KEAU/KRNH/KSTC ALL
HAVE A CHANCE FOR MVFR OR EVEN VFR THIS AFTERNOON. LITTLE RAIN IS
EXPECTED TODAY AND EVEN TONIGHT - LIGHT RAIN THIS MORNING OR
DRIZZLE AS LONG AS THERE ARE LOW CLOUDS AROUND.
KMSP...
LOW CEILINGS WILL CONTINUE FOR WHAT REMAINS OF THE EARLY
MORNING...BUT WE HAVE HIGH CONFIDENCE IN IMPROVEMENT BY THE EARLY
AFTERNOON. ANY CLEARING LATER TODAY SHOULD BE RELATIVELY SHORT
LIVED WITH WRAP AROUND CLOUD COVER MOVING BACK IN LATE THIS
EVENING. ONLY A LITTLE BIT OF LIGHT RAIN OR DRIZZLE TODAY AND THAT
SHOULD PRIMARILY BE CONFINED TO THE MORNING. THE STEADIER LIGHT
RAIN RETURNS TOMORROW.
/OUTLOOK FOR KMSP/
SUN...MVFR OR IFR LIKELY. PERIODS OF -RA/-DZ. WINDS NW 10-15 KTS.
MON...VFR...MVFR POSSIBLE EARLY. 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...CLF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1030 AM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 1029 AM CDT SAT OCT 5 2013
THE SURFACE LOW WAS LOCATED IN SOUTHEAST SOUTH DAKOTA AS OF 15Z
WITH AN OCCLUDED FRONT EXTENDING FROM THIS LOW ACROSS PORTIONS OF
S-C MINNESOTA INTO FAR SOUTHWEST WISCONSIN. 925MB BOUNDARY IS IN
NEARLY THE SAME LOCATION WITH HIGHER THETA-E AIR NORTH AND EAST OF THE
BOUNDARY. THIS FRONT MARKED A CLEARING LINE WITH DRY CONDITIONS
BEHIND IT OVER MUCH OF SOUTHERN MINNESOTA. LIGHT RAIN/DRIZZLE
CONTINUED OVER PORTIONS OF THE NORTHLAND THIS MORNING...BUT WASN`T
REAL WIDESPREAD. WE TRIMMED BACK SOME ON POPS THROUGH MID
AFTERNOON BUT MAY HAVE TO FURTHER AS SEVERAL OBSERVATIONS WERE NOT
REPORTING ANY RAIN AS OF 15Z. WE DO EXPECT AN INCREASE IN COVERAGE
LATER THIS AFTERNOON AS THE STACKED LOW PRESSURE SYSTEM MOVES
FURTHER EAST. THE LATEST HRRR WAS DOING A DECENT JOB DEPICTING THE
LIGHT RAIN THIS MORNING AND SHOWS COVERAGE INCREASING QUITE A BIT
MID TO LATE AFTERNOON ACROSS THE SOUTHERN THIRD...THEN FURTHER
NORTH THIS EVENING. THE 12Z NAM SUPPORTS THE HRRR BUT STILL MAY BE
OVERDONE WITH IT`S QPF. AREAS OF DRIZZLE WILL ALSO OCCUR AROUND
LAKE SUPERIOR. WE CONTINUE TO MONITOR RADAR TRENDS AND LATEST
MODEL OUTPUT AND ADJUST AS NEEDED.
IT REMAINS WINDY AROUND LAKE SUPERIOR...ESPECIALLY FROM SILVER BAY
TO THE TWIN PORTS AND ALONG THE BAYFIELD PENINSULA. KDLH WAS
GUSTING TO 42 MPH AS OF THE 1008 AM OBSERVATION AND TO 46 MPH ON
PARK POINT. WE`LL KEEP THE WIND ADVISORY GOING AS IS FOR NOW. WE
MAY NEED TO EXTEND IT FOR THE TWIN PORTS AREA TO TWO HARBORS/SILVER
BAY. THE WIND WASN`T AS STRONG ACROSS BAYFIELD/ASHLAND COUNTIES
BUT SOME HIGHER GUSTS WILL REMAIN POSSIBLE THERE AS WELL.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 410 AM CDT SAT OCT 5 2013
AT 4 AM...RAIN CONTINUED TO MOVE NORTHWARD ACROSS THE CWA. THE
MASSIVE LOW PRESSURE SYSTEM WAS LOCATED IN CENTRAL SOUTH
DAKOTA...WITH AN OCCLUDED FRONT STRETCHING EASTWARD THROUGH SW MN.
TEMPERATURES AT 4 AM WERE GENERALLY IN THE MID TO UPPER 40S NORTH
AND LOWER TO MIDDLE 50S SOUTH. STRONG WINDS CONTINUED NEAR LAKE
SUPERIOR...WITH KDYT AND KDLH STILL GUSTING ABOVE 40 MPH. THE RAIN
HAD DIMINISHED CONSIDERABLY ACROSS THE SOUTHERN THIRD OF THE CWA
BUT CONTINUED FROM THE TWIN PORTS NORTHWARD.
THE MAIN FOCUS FOR TODAY THROUGH SUNDAY IS THE EXTENT AND TIMING
OF VARIOUS WAVES OF PRECIPITATION. THE NAM AND THE NSSL AND NCEP
WRF RUNS SEEM TO HAVE A DECENT HANDLE ON THE SITUATION. THEY ALL
BRING A REPRIEVE IN THE RAIN TO THE SOUTHERN CWA...BEFORE
INCREASING AGAIN THIS AFTERNOON. DESPITE SOME BREAKS IN THE
PRECIPITATION...THERE SHOULD BE AREAS OF DRIZZLE AS WELL. WILL
CONTINUE WITH HIGH POPS. A LITTLE CONCERNED WE MAY NEED TO
EVENTUALLY PULL BACK ON POPS IN THE SOUTH...BUT KEPT THEM HIGH DUE
TO THE POTENTIAL FOR DRIZZLE.
RAIN SHOULD BECOME WIDESPREAD AGAIN TONIGHT...AS SURFACE LOW
PRESSURE RE-FORMS OVER WISCONSIN. FOR THAT REASON...WILL CONTINUE
WITH HIGH POPS TONIGHT...AND THEN GRADUALLY DECREASE IN PLACE AS
THE LOW STARTS TO FALL APART ON SUNDAY. WILL CONTINUE POPS
THROUGHOUT THE DAY THOUGH...AS THERE SHOULD BE SOME LINGERING
PRECIPITATION.
WILL CONTINUE WITH THE WIND ADVISORY FOR TODAY DUE TO THE STRONG
EASTERLY WINDS COMING OFF LAKE SUPERIOR.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 AM CDT SAT OCT 5 2013
ANOMALOUS SFC/MID LVL LOW WILL DRIFT EAST OF REGION BE EARLY MONDAY
AS SPLIT FLOW IN WESTERLIES ALLOWS NRN BRANCH TO DEEPEN OVER REGION.
PRECIP WILL GRADUALLY DIMINISH OVER THE ERN CWA AS CYCLONIC
CIRCULATION LOOSENS ITS GRIP MONDAY. MDLS AGREE THAT A RELATIVELY
QUIET DRY WEATHER PATTERN WILL COMMENCE TUESDAY AND PERSIST THROUGH
THE WEEK. SYNOPTIC PATTERN WILL FEATURE A DEVELOPING LARGE AMPLITUDE
UPPER TROF OVER CALIFORNIA WITH A BROAD UPPER RIDGE ACROSS THE NRN
PLAINS AND THE WRN GT LAKES. A SFC TROUGH WILL BEGIN TO FORM OVER
THE PLAINS AND EXTEND NORTH INTO NWRN MN BY WED EVENING. ALTHOUGH A
WARM ADVECTION REGIME WILL BECOME MORE PRONOUNCED ACROSS THE CWA AT
THIS TIME IT APPEARS THE MORE FAVORABLE LIFT WILL OCCUR TO THE WEST
OF THE REGION THROUGH THURSDAY. CONFIDENCE LOWERS BY FRIDAY AS TO
HOW FAR EAST THE EJECTING MID LVL SYSTEM WILL TRACK DUE TO
DOWNSTREAM UPPER RIDGE OVER MS RIVER VALLEY. WILL KEEP MAINLY DRY
OVER ALL OF CWA THROUGH FRIDAY BEFORE ALLOWING POPS TO RENTER THE
CWA FRIDAY NIGHT. TEMPS WILL RISE ABOVE CLIMO MOST OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 643 AM CDT SAT OCT 5 2013
INITIAL AREA OF RAIN IS PUSHING NORTH OF MOST TERMINALS WITH
REDEVELOPMENT OVER SERN MN. LOW CLOUDS WILL BE EXTENSIVE TODAY AS
MID LVL DRY SLOT MOVES OVERHEAD. CONFIDENCE ON REDEVELOPMENT OF
RAIN AT MOST TERMINALS IS LOW. SHOULD SEE SOME INCREASE IN
CEILINGS TODAY WITH BDRY LYR WARMING BUT LOWERING OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 44 51 41 / 80 80 60 20
INL 47 39 54 38 / 70 50 40 10
BRD 52 44 53 40 / 80 80 60 20
HYR 57 46 59 41 / 80 80 50 30
ASX 53 46 57 44 / 80 80 60 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR MNZ020-037.
WI...WIND ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR WIZ001-002.
LS...GALE WARNING UNTIL 10 PM CDT THIS EVENING FOR LSZ141>147.
SMALL CRAFT ADVISORY UNTIL 4 AM CDT SUNDAY FOR LSZ121-140-148.
&&
$$
UPDATE...MELDE
SHORT TERM...DAP
LONG TERM...CANNON
AVIATION...CANNON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1157 PM CDT Fri Oct 4 2013
.UPDATE:
Issued at 950 PM CDT Fri Oct 4 2013
Inherited forecast still looks on track...so made no major
changes. Warm advection SHRAS have moved out of SW IL. SHRA/TSTMS
along and ahead of the front across ern KS/wrn MO timed to reach
the wrn CWA around 9-10Z...if it holds together. Several
solutions have moisture convergence along the front weakening
significantly overnight across nthrn MO. Going fcst reflects the
assumption that precip in one form or another will reach our CWA
prior to daybreak. Besides massaging other grids to reflect
ongoing trends...existing fcst looks good.
2%
&&
.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 06z TAFs through 06z Saturday Night)
Issued at 1125 PM CDT Fri Oct 4 2013
Latest surface analysis shows the cold frontal boundary entering
western Missouri. Band of showers and thunderstorms extending
north-central Missouri through north-central Oklahoma continues to
move northeast. Expect scattered showers and possible thunderstorm
to enter Columbia MO area and Quincy IL around 0900 UTC. Scattered
showers and a few thunderstorms will enter STL area after 1500
UTC. Cold front expected to move across STL area after 1700 UTC.
Post frontal light rain will continue through late afternoon.
Specifics for KSTL: Scattered showers and a few thunderstorms will
move through STL area after 1500 UTC. Southwest winds of 8 to 10
kts expected during the mid to late morning hours. Brief stronger
gusts are possible in the vicinty of thunderstorms. Cold front
expected through STL between 1700 and 1800 UTC. Post frontal light
rain expected much of the afternoon and ending late afternoon.
Westerly wind of 8 to 10 kts expected during the afternoon.
RP
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
900 PM MDT Sun Oct 6 2013
.DISCUSSION...
Have made minor adjustments to the sky and wind grids and will issue
an update this evening. Surface winds have decreased over the plains
and have adjusted accordingly. The RUC continues to indicate a
tightening of the surface gradient after 07z and HRRR analysis also
supports mid level winds strengthening around this time along the
Northern Rocky Mountain Front. This gives some corroboration for
the high wind warning that goes in effect for this area at 09z. A
chinook arch remains in place adjacent to the northern front range
and have adjusted sky grids to better define its location.
Temperatures look reasonable. Emanuel
&&
.AVIATION...
UPDATED 2348Z.
Chinook arch remains in place across the Northern Rocky Mountain
Front bringing SCT-BKN mid/upper level clouds to KCTB. Just a few
clouds over the remaining terminals. Wind gusts have begun to
subside across north-central MT this afternoon with generally
light and variable winds over southwest MT. Expect this trend to
remain intact through the overnight hours. Wind gusts will pick
once again late Monday morning...especially over north-central MT.
Gusts could exceed 30kts from the southwest. Foltz
&&
.PREV DISCUSSION...Issued 249 PM MDT Sun Oct 6 2013
Today through Tuesday...Upper ridge over the region will gradually
progress eastward overnight. Despite models continuing to show
completely clear skies over the forecast area tonight, Have opted
to learn from failure and keep a mention of partly to mostly
cloudy skies for the Rocky Mountain Front where a persistent
chinook arch has defied the skills of every supercomputer that
forecasts for this area. Breezy conditions will continue overnight
as well, with temperatures expected to remain above guidance
values much like those seen last night. Mid level winds are also
expected to increase overnight as the next upper disturbance
approaches the area causing surface pressure to fall east of the
divide. Conditions look borderline favorable for high winds along
the Northern Rocky Mountain Front late tonight. Winds will likely
diminish during the morning hours but will pick up again during
the afternoon as a cold front pushes through the state. Have
issued a High Wind Warning for just the Northern Rocky Mountain
Front from 3 AM Monday through 6 AM Tuesday. Conditions may also
approach high wind criteria along the Southern Rocky Mountain
Front and at Norris Hill in Madison County but confidence is not
high enough to warrant highlights at this time. Behind the
previously mentioned frontal system a moist Pacific flow will bring
widespread rain and snow showers to the mountains of the Continental
Divide from the Canadian border south to about Highway 200.
Temperatures and snow levels drop behind the front with showers
continuing over the mountains through late Tuesday but heavy snow
accumulations are not expected. mpj
Tuesday Night through Sunday...Upper level trof that moves through
the PacNW area earlier in the week will continue to drop well south
into the Great Basin states, with a closed low pressure center
developing along the CA/NV border by late Wed. Moisture on the
eastern flank of the trof will spread scattered mtn snow/valley rain
showers, mainly over the southwest counties, through Thurs evening.
Current long-range forecast models are in decent agreement that the
low center will remain far enough that our region will only see
light precipitation amounts through midday Thurs. As the Great
Basin system exits into the Central Rockies, a second trof and
associated cold front will drop south from BC/Alberta late Thurs
into Fri. GFS and ECMWF models still not in sync on temperatures and
precipitation with this second system, as the ECMWF model continues
to be slightly colder and wetter through early Fri afternoon. Late
Fri through Sat aftn looks cloudy but dry as we`ll between the
departing second trof and the next Pacific system that arrives Sat
evening with another round of scattered light showers. High
temperatures will remain about 8 to 12 degrees below normal each day
of the extended period, with low-mid 50s on Wed-Thur and upper 40s
for Fri-Sun. Waranauskas
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 48 70 42 53 / 0 0 0 10
CTB 46 67 40 53 / 0 0 10 20
HLN 36 68 39 53 / 0 10 10 20
BZN 30 67 36 54 / 0 0 0 20
WEY 24 56 31 47 / 0 0 0 20
DLN 33 63 33 49 / 0 0 10 20
HVR 40 74 41 60 / 0 0 0 10
LWT 37 71 37 53 / 0 0 0 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING from 3 AM Monday to 6 AM MDT Tuesday Northern
Rocky Mountain Front.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1236 PM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
THE MSAS SHOWS THE SFC LOW NEARLY STATIONARY THIS MORNING ACROSS
SCNTL SD. THE LOW IS IN THE PROCESS OF DOING A LOOP. THIS
AFTERNOON IT WILL DRIFT EAST AT 5 MPH INTO SERN SD AND THIS IS
CONSISTENT WITH THE MOTION OF THE 500 MB LOW AT JUST 6 KT.
VERY SLOW STORM MOTIONS OF THIS TYPE...5 MPH...OFTEN PRODUCE HIGH
WIND EVENTS IN THE CNTL PLAINS. THE GFS...ECM AND RAP SHOW
SUSTAINED WINDS INCREASING TO AROUND 40 MPH ACROSS NCNTL NEB THIS
AFTERNOON WITH GUSTS TO 58 MPH IN THE RAP AND HRRR MODELS. THE
NAM KEEPS THE GUSTS BELOW 58 MPH THIS AFTN. MEANWHILE THE MET
GUIDANCE SHOWS NO HIGH WIND EVENT AT ALL WHILE THE MAV GUIDANCE
FAVORS SWRN NEB. THE MULTI LAYER WINDS IN THE RAP MODEL FROM
H850MB TO H700MB KEEP WINDS AT 60 KTS OR LESS AND THIS IS
CONSISTENT WITH A HIGH END WIND ADVISORY WITH A FEW GUSTS TO 58
MPH.
THUS THERE IS A SPLIT IN THE MODEL DATA. A HIGH END WIND ADVISORY
EVENT WOULD APPEAR TO BE THE MOST LIKELY SOLN INDICATED BY THE
MODELS BUT LOCAL STUDIES SUGGEST A HIGH WIND EVENT WOULD UNFOLD
THIS AFTERNOON. A WIND ADVISORY WILL CONTINUE TODAY ACROSS ALL
AREAS EXCEPT WHERE THE WINTER STORM WARNING IS IN EFFECT.
WINTER STORM CONDITIONS ARE LIKELY ONGOING ACROSS NRN SHERIDAN
AND WRN CHERRY COUNTIES THIS MORNING. THE RADAR MAY BE
OVERSHOOTING THE DENDRITIC LAYER. THE ELLSWORTH NEDOR CAM IS
QUIET WHILE THE RUSHVILLE CAM CONTINUES TO SHOW SNOW AND BLOWING
SNOW WITH VISIBILITY AROUND 2 MILES OR SO. THE 08Z KIEN OB SHOWS
1/2 MILE VISIBILITY WITH A VERTICAL VISIBILITY OF JUST 500 FEET.
THE REST OF THE NEDOR CAMS ARE DARK SO WE WILL HAVE TO WAIT FOR
SUNRISE TO GET A BETTER ANALYSIS OF THE SITUATION ACROSS NW NEB.
THE WINTER STORM WARNING WILL CONTINUE UNTIL 18Z AS FORECAST.
GIVEN THE UPPER LOW HAS STALLED ACROSS THE CNTL PLAINS...THE
MODEL CONSENSUS SHOWS WRAPAROUND RAIN AND SNOW TODAY THROUGH
SUNDAY MORNING. THE UPPER LEVEL LOW IS EXPECTED TO CONTINUE
MOVING SLOWLY EAST SOUTHEAST INTO SRN IOWA BY LATE SUNDAY
AFTERNOON. A MULTI MODEL CONSENSUS WAS USED FOR POPS TONIGHT AND
SUNDAY. THE RAP MODEL WAS USED EXCLUSIVELY FOR THE TODAY PERIOD.
NONE OF THE MODELS ARE SHOWING VERY HEAVY QPF AND SNOW TOTALS OF
2 INCHES OR LESS ARE EXPECTED BASED ON THAT OUTPUT. THERE IS SOME
UNCERTAINTY WITH THIS FORECAST AS THE 850 MB MOISTURE TRANSPORT
IS STILL QUITE STRONG ACROSS THE NRN PLAINS AND OCCASIONAL
LIGHTNING STRIKES ARE STILL SHOWING UP AT 08Z. THE NAM WHICH
APPEARS TO HAVE THE BEST HANDLE THE MASSIVE QPF ASSOCIATED WITH
THIS STORM GENERALLY KEEPS QPF LESS THAN 0.10 INCHES IN ANY 3
HOUR PERIOD ACROSS NRN NEB.
OTHERWISE...HIGHS TODAY RISE INTO THE 30S AND 40S ACCORDING TO A
BLEND OF BIAS CORRECTED AND DETERMINISTIC DATA. THE MODELS ARE
FORECASTING LOWS IN THE MID 20S TONIGHT ACROSS THE SNOW FIELD
ACROSS NWRN NEB WITH LOWER 30S ELSEWHERE. IF THE WRN HALF OF THE
FORECAST AREA CLEARS OUT TONIGHT AS INDICATED IN THE MODELS THEN
THESE LOWS COULD BE 5 OR MORE DEGREES COLDER. HIGHS SUNDAY RISE
INTO THE 40S ACROSS THE SNOW COVERED NORTHWEST WITH 50S AND 60S
ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
BY SUNDAY NIGHT THE LOW PRESSURE SYSTEM WILL HAVE PUSHED TOWARDS
THE MID MISS RVR VALLEY AND THE WRAP AROUND MOISTURE WILL HAVE
SHIFTED INTO EASTERN NEB. MEANWHILE AN UPPER LEVEL RIDGE WILL
BUILD ACROSS THE WEST...AS THE NEXT TROUGH PUSHES ACROSS
NORTHEASTERN PACIFIC OCEAN.
MONDAY THROUGH THURSDAY THE PACIFIC TROUGH WILL DIG TOWARDS THE
DESERT SOUTHWEST WHILE THE UPPER RIDGE SHIFTS EAST ACROSS THE
PLAINS. AT THE SFC HIGH PRESSURE WILL DOMINATE THE PLAINS THROUGH
MUCH OF THE WEEK. THUS EXPECT MILD CONDITIONS WITH 70S AND A FEW
MID/UPPER 60S ACROSS THE NW ZONES WHERE SOME INFLUENCE FROM THE
HEAVY SNOW PACK IS LIKELY TO LIMIT THE HEATING. ONCE THE SNOW
MELTS...COULD SEE MORE WIDESPREAD HIGHS INTO THE 70S ACROSS THE
NW. WITH THE WARM AIR MASS...EXPECT SEASONALLY WARM
LOWS...GENERALLY IN THE 40S SPOTTED WITH A FEW UPPER 30S.
LATE THURSDAY INTO FRIDAY THE LOW OVER THE SW WILL BEGIN TO EJECT
ONTO THE NORTHERN PLAINS. MODELS IN FAIR AGREEMENT...CONSIDERING
6/7 DAYS OUT...WITH A TRACK OF THE UPPER LOW ACROSS THE CENTRAL
ROCKIES AND INTO S DAKOTA. THE MODELS CONTINUE TO TRACK THE LOW TO
THE NE...INTO CANADA OVER THE WEEKEND. AS THE LOW PUSHES ONTO THE
ROCKIES...GOOD MOISTURE TRANSPORT WITH S WINDS EXPECTED ACROSS THE
AREA. POPS ARE NEEDED FOR THURSDAY INTO FRIDAY...HOWEVER PENDING
THE TRACK AND THE DRY SLOT...CONCERNED AMOUNTS MAY NOT AMOUNT TO
TOO MUCH OVER PART OF THE CWA. THUS WILL HOLD POPS IN THE SLIGHT
CHANCE AND LOWER CHANCE CATEGORY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1229 PM CDT SAT OCT 5 2013
STRONG LOW PRESSURE SYSTEM SLOWLY MOVING THROUGH THE NORTHERN
PLAINS WILL CONTINUE TO IMPACT THE AVIATION FORECAST IN WESTERN
AND NORTH CENTRAL NEBRASKA THROUGH SUNDAY MORNING. SNOW SQUALLS
WILL MOVE THROUGH KVTN DURING THE AFTERNOON AND BRING VSBYS DOWN
TO 2SM OR LESS AT TIMES. SNOW SHOWER ACTIVITY WILL BEGIN TO TAPER
OFF THIS EVENING AND OVERNIGHT. NO SNOW SHOWERS ARE ANTICIPATED TO
REACH KLBF...HOWEVER CIGS WILL HOVER AT OR JUST ABOVE MVFR LEVELS
THROUGH THE AFTERNOON.
GUSTY WINDS NORTHWEST WINDS WILL REMAIN THROUGH THE TAF PERIOD.
STRONGEST WINDS GUSTING TO 35 TO 40 KTS ARE EXPECTED THIS
AFTERNOON AND EARLY EVENING. WINDS WILL BEGIN TO RELAX AFTER 00Z
WITH WIND GUSTS OF 20 TO 25 KTS EXPECTED BY SUNDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR
NEZ006>010-022>029-035>038-056>059-069>071.
WINTER WEATHER ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING
FOR NEZ004-005-094.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
637 AM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
THE MSAS SHOWS THE SFC LOW NEARLY STATIONARY THIS MORNING ACROSS
SCNTL SD. THE LOW IS IN THE PROCESS OF DOING A LOOP. THIS
AFTERNOON IT WILL DRIFT EAST AT 5 MPH INTO SERN SD AND THIS IS
CONSISTENT WITH THE MOTION OF THE 500 MB LOW AT JUST 6 KT.
VERY SLOW STORM MOTIONS OF THIS TYPE...5 MPH...OFTEN PRODUCE HIGH
WIND EVENTS IN THE CNTL PLAINS. THE GFS...ECM AND RAP SHOW
SUSTAINED WINDS INCREASING TO AROUND 40 MPH ACROSS NCNTL NEB THIS
AFTERNOON WITH GUSTS TO 58 MPH IN THE RAP AND HRRR MODELS. THE
NAM KEEPS THE GUSTS BELOW 58 MPH THIS AFTN. MEANWHILE THE MET
GUIDANCE SHOWS NO HIGH WIND EVENT AT ALL WHILE THE MAV GUIDANCE
FAVORS SWRN NEB. THE MULTI LAYER WINDS IN THE RAP MODEL FROM
H850MB TO H700MB KEEP WINDS AT 60 KTS OR LESS AND THIS IS
CONSISTENT WITH A HIGH END WIND ADVISORY WITH A FEW GUSTS TO 58
MPH.
THUS THERE IS A SPLIT IN THE MODEL DATA. A HIGH END WIND ADVISORY
EVENT WOULD APPEAR TO BE THE MOST LIKELY SOLN INDICATED BY THE
MODELS BUT LOCAL STUDIES SUGGEST A HIGH WIND EVENT WOULD UNFOLD
THIS AFTERNOON. A WIND ADVISORY WILL CONTINUE TODAY ACROSS ALL
AREAS EXCEPT WHERE THE WINTER STORM WARNING IS IN EFFECT.
WINTER STORM CONDITIONS ARE LIKELY ONGOING ACROSS NRN SHERIDAN
AND WRN CHERRY COUNTIES THIS MORNING. THE RADAR MAY BE
OVERSHOOTING THE DENDRITIC LAYER. THE ELLSWORTH NEDOR CAM IS
QUIET WHILE THE RUSHVILLE CAM CONTINUES TO SHOW SNOW AND BLOWING
SNOW WITH VISIBILITY AROUND 2 MILES OR SO. THE 08Z KIEN OB SHOWS
1/2 MILE VISIBILITY WITH A VERTICAL VISIBILITY OF JUST 500 FEET.
THE REST OF THE NEDOR CAMS ARE DARK SO WE WILL HAVE TO WAIT FOR
SUNRISE TO GET A BETTER ANALYSIS OF THE SITUATION ACROSS NW NEB.
THE WINTER STORM WARNING WILL CONTINUE UNTIL 18Z AS FORECAST.
GIVEN THE UPPER LOW HAS STALLED ACROSS THE CNTL PLAINS...THE
MODEL CONSENSUS SHOWS WRAPAROUND RAIN AND SNOW TODAY THROUGH
SUNDAY MORNING. THE UPPER LEVEL LOW IS EXPECTED TO CONTINUE
MOVING SLOWLY EAST SOUTHEAST INTO SRN IOWA BY LATE SUNDAY
AFTERNOON. A MULTI MODEL CONSENSUS WAS USED FOR POPS TONIGHT AND
SUNDAY. THE RAP MODEL WAS USED EXCLUSIVELY FOR THE TODAY PERIOD.
NONE OF THE MODELS ARE SHOWING VERY HEAVY QPF AND SNOW TOTALS OF
2 INCHES OR LESS ARE EXPECTED BASED ON THAT OUTPUT. THERE IS SOME
UNCERTAINTY WITH THIS FORECAST AS THE 850 MB MOISTURE TRANSPORT
IS STILL QUITE STRONG ACROSS THE NRN PLAINS AND OCCASIONAL
LIGHTNING STRIKES ARE STILL SHOWING UP AT 08Z. THE NAM WHICH
APPEARS TO HAVE THE BEST HANDLE THE MASSIVE QPF ASSOCIATED WITH
THIS STORM GENERALLY KEEPS QPF LESS THAN 0.10 INCHES IN ANY 3
HOUR PERIOD ACROSS NRN NEB.
OTHERWISE...HIGHS TODAY RISE INTO THE 30S AND 40S ACCORDING TO A
BLEND OF BIAS CORRECTED AND DETERMINISTIC DATA. THE MODELS ARE
FORECASTING LOWS IN THE MID 20S TONIGHT ACROSS THE SNOW FIELD
ACROSS NWRN NEB WITH LOWER 30S ELSEWHERE. IF THE WRN HALF OF THE
FORECAST AREA CLEARS OUT TONIGHT AS INDICATED IN THE MODELS THEN
THESE LOWS COULD BE 5 OR MORE DEGREES COLDER. HIGHS SUNDAY RISE
INTO THE 40S ACROSS THE SNOW COVERED NORTHWEST WITH 50S AND 60S
ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
BY SUNDAY NIGHT THE LOW PRESSURE SYSTEM WILL HAVE PUSHED TOWARDS
THE MID MISS RVR VALLEY AND THE WRAP AROUND MOISTURE WILL HAVE
SHIFTED INTO EASTERN NEB. MEANWHILE AN UPPER LEVEL RIDGE WILL
BUILD ACROSS THE WEST...AS THE NEXT TROUGH PUSHES ACROSS
NORTHEASTERN PACIFIC OCEAN.
MONDAY THROUGH THURSDAY THE PACIFIC TROUGH WILL DIG TOWARDS THE
DESERT SOUTHWEST WHILE THE UPPER RIDGE SHIFTS EAST ACROSS THE
PLAINS. AT THE SFC HIGH PRESSURE WILL DOMINATE THE PLAINS THROUGH
MUCH OF THE WEEK. THUS EXPECT MILD CONDITIONS WITH 70S AND A FEW
MID/UPPER 60S ACROSS THE NW ZONES WHERE SOME INFLUENCE FROM THE
HEAVY SNOW PACK IS LIKELY TO LIMIT THE HEATING. ONCE THE SNOW
MELTS...COULD SEE MORE WIDESPREAD HIGHS INTO THE 70S ACROSS THE
NW. WITH THE WARM AIR MASS...EXPECT SEASONALLY WARM
LOWS...GENERALLY IN THE 40S SPOTTED WITH A FEW UPPER 30S.
LATE THURSDAY INTO FRIDAY THE LOW OVER THE SW WILL BEGIN TO EJECT
ONTO THE NORTHERN PLAINS. MODELS IN FAIR AGREEMENT...CONSIDERING
6/7 DAYS OUT...WITH A TRACK OF THE UPPER LOW ACROSS THE CENTRAL
ROCKIES AND INTO S DAKOTA. THE MODELS CONTINUE TO TRACK THE LOW TO
THE NE...INTO CANADA OVER THE WEEKEND. AS THE LOW PUSHES ONTO THE
ROCKIES...GOOD MOISTURE TRANSPORT WITH S WINDS EXPECTED ACROSS THE
AREA. POPS ARE NEEDED FOR THURSDAY INTO FRIDAY...HOWEVER PENDING
THE TRACK AND THE DRY SLOT...CONCERNED AMOUNTS MAY NOT AMOUNT TO
TOO MUCH OVER PART OF THE CWA. THUS WILL HOLD POPS IN THE SLIGHT
CHANCE AND LOWER CHANCE CATEGORY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 637 AM CDT SAT OCT 5 2013
STRONG TO PERHAPS HIGH WIND CONDITION TODAY WITH WINDS OPERATING
AT 31032G45KT. GIVEN THE STORM MOTION OF JUST 6 KTS INDICATED BY
THE RAP MODEL...STRONGER WINDS COULD DEVELOP.
IFR/MVFR IN SNOW AND LOW CIGS SHOULD GRADUALLY DRIFT EAST OF
HIGHWAY 83 LATE TONIGHT. THIS AREA OF CLOUDS WILL ALSO DRIFT EAST
AT 6 KTS. THE AREA AFFECTED WILL BE MOSTLY ALONG AND NORTH OF
NEBRASKA HIGHWAY 2.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ008-
022>027-035>038-056>059-069>071.
WINTER WEATHER ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR NEZ005.
WINTER STORM WARNING UNTIL NOON MDT TODAY FOR NEZ004-094.
WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR NEZ006-007-009-010-028-029.
&&
$$
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
357 AM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
THE MSAS SHOWS THE SFC LOW NEARLY STATIONARY THIS MORNING ACROSS
SCNTL SD. THE LOW IS IN THE PROCESS OF DOING A LOOP. THIS
AFTERNOON IT WILL DRIFT EAST AT 5 MPH INTO SERN SD AND THIS IS
CONSISTENT WITH THE MOTION OF THE 500 MB LOW AT JUST 6 KT.
VERY SLOW STORM MOTIONS OF THIS TYPE...5 MPH...OFTEN PRODUCE HIGH
WIND EVENTS IN THE CNTL PLAINS. THE GFS...ECM AND RAP SHOW
SUSTAINED WINDS INCREASING TO AROUND 40 MPH ACROSS NCNTL NEB THIS
AFTERNOON WITH GUSTS TO 58 MPH IN THE RAP AND HRRR MODELS. THE
NAM KEEPS THE GUSTS BELOW 58 MPH THIS AFTN. MEANWHILE THE MET
GUIDANCE SHOWS NO HIGH WIND EVENT AT ALL WHILE THE MAV GUIDANCE
FAVORS SWRN NEB. THE MULTI LAYER WINDS IN THE RAP MODEL FROM
H850MB TO H700MB KEEP WINDS AT 60 KTS OR LESS AND THIS IS
CONSISTENT WITH A HIGH END WIND ADVISORY WITH A FEW GUSTS TO 58
MPH.
THUS THERE IS A SPLIT IN THE MODEL DATA. A HIGH END WIND ADVISORY
EVENT WOULD APPEAR TO BE THE MOST LIKELY SOLN INDICATED BY THE
MODELS BUT LOCAL STUDIES SUGGEST A HIGH WIND EVENT WOULD UNFOLD
THIS AFTERNOON. A WIND ADVISORY WILL CONTINUE TODAY ACROSS ALL
AREAS EXCEPT WHERE THE WINTER STORM WARNING IS IN EFFECT.
WINTER STORM CONDITIONS ARE LIKELY ONGOING ACROSS NRN SHERIDAN
AND WRN CHERRY COUNTIES THIS MORNING. THE RADAR MAY BE
OVERSHOOTING THE DENDRITIC LAYER. THE ELLSWORTH NEDOR CAM IS
QUIET WHILE THE RUSHVILLE CAM CONTINUES TO SHOW SNOW AND BLOWING
SNOW WITH VISIBILITY AROUND 2 MILES OR SO. THE 08Z KIEN OB SHOWS
1/2 MILE VISIBILITY WITH A VERTICAL VISIBILITY OF JUST 500 FEET.
THE REST OF THE NEDOR CAMS ARE DARK SO WE WILL HAVE TO WAIT FOR
SUNRISE TO GET A BETTER ANALYSIS OF THE SITUATION ACROSS NW NEB.
THE WINTER STORM WARNING WILL CONTINUE UNTIL 18Z AS FORECAST.
GIVEN THE UPPER LOW HAS STALLED ACROSS THE CNTL PLAINS...THE
MODEL CONSENSUS SHOWS WRAPAROUND RAIN AND SNOW TODAY THROUGH
SUNDAY MORNING. THE UPPER LEVEL LOW IS EXPECTED TO CONTINUE
MOVING SLOWLY EAST SOUTHEAST INTO SRN IOWA BY LATE SUNDAY
AFTERNOON. A MULTI MODEL CONSENSUS WAS USED FOR POPS TONIGHT AND
SUNDAY. THE RAP MODEL WAS USED EXCLUSIVELY FOR THE TODAY PERIOD.
NONE OF THE MODELS ARE SHOWING VERY HEAVY QPF AND SNOW TOTALS OF
2 INCHES OR LESS ARE EXPECTED BASED ON THAT OUTPUT. THERE IS SOME
UNCERTAINTY WITH THIS FORECAST AS THE 850 MB MOISTURE TRANSPORT
IS STILL QUITE STRONG ACROSS THE NRN PLAINS AND OCCASIONAL
LIGHTNING STRIKES ARE STILL SHOWING UP AT 08Z. THE NAM WHICH
APPEARS TO HAVE THE BEST HANDLE THE MASSIVE QPF ASSOCIATED WITH
THIS STORM GENERALLY KEEPS QPF LESS THAN 0.10 INCHES IN ANY 3
HOUR PERIOD ACROSS NRN NEB.
OTHERWISE...HIGHS TODAY RISE INTO THE 30S AND 40S ACCORDING TO A
BLEND OF BIAS CORRECTED AND DETERMINISTIC DATA. THE MODELS ARE
FORECASTING LOWS IN THE MID 20S TONIGHT ACROSS THE SNOW FIELD
ACROSS NWRN NEB WITH LOWER 30S ELSEWHERE. IF THE WRN HALF OF THE
FORECAST AREA CLEARS OUT TONIGHT AS INDICATED IN THE MODELS THEN
THESE LOWS COULD BE 5 OR MORE DEGREES COLDER. HIGHS SUNDAY RISE
INTO THE 40S ACROSS THE SNOW COVERED NORTHWEST WITH 50S AND 60S
ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 350 AM CDT SAT OCT 5 2013
BY SUNDAY NIGHT THE LOW PRESSURE SYSTEM WILL HAVE PUSHED TOWARDS
THE MID MISS RVR VALLEY AND THE WRAP AROUND MOISTURE WILL HAVE
SHIFTED INTO EASTERN NEB. MEANWHILE AN UPPER LEVEL RIDGE WILL
BUILD ACROSS THE WEST...AS THE NEXT TROUGH PUSHES ACROSS
NORTHEASTERN PACIFIC OCEAN.
MONDAY THROUGH THURSDAY THE PACIFIC TROUGH WILL DIG TOWARDS THE
DESERT SOUTHWEST WHILE THE UPPER RIDGE SHIFTS EAST ACROSS THE
PLAINS. AT THE SFC HIGH PRESSURE WILL DOMINATE THE PLAINS THROUGH
MUCH OF THE WEEK. THUS EXPECT MILD CONDITIONS WITH 70S AND A FEW
MID/UPPER 60S ACROSS THE NW ZONES WHERE SOME INFLUENCE FROM THE
HEAVY SNOW PACK IS LIKELY TO LIMIT THE HEATING. ONCE THE SNOW
MELTS...COULD SEE MORE WIDESPREAD HIGHS INTO THE 70S ACROSS THE
NW. WITH THE WARM AIR MASS...EXPECT SEASONALLY WARM
LOWS...GENERALLY IN THE 40S SPOTTED WITH A FEW UPPER 30S.
LATE THURSDAY INTO FRIDAY THE LOW OVER THE SW WILL BEGIN TO EJECT
ONTO THE NORTHERN PLAINS. MODELS IN FAIR AGREEMENT...CONSIDERING
6/7 DAYS OUT...WITH A TRACK OF THE UPPER LOW ACROSS THE CENTRAL
ROCKIES AND INTO S DAKOTA. THE MODELS CONTINUE TO TRACK THE LOW TO
THE NE...INTO CANADA OVER THE WEEKEND. AS THE LOW PUSHES ONTO THE
ROCKIES...GOOD MOISTURE TRANSPORT WITH S WINDS EXPECTED ACROSS THE
AREA. POPS ARE NEEDED FOR THURSDAY INTO FRIDAY...HOWEVER PENDING
THE TRACK AND THE DRY SLOT...CONCERNED AMOUNTS MAY NOT AMOUNT TO
TOO MUCH OVER PART OF THE CWA. THUS WILL HOLD POPS IN THE SLIGHT
CHANCE AND LOWER CHANCE CATEGORY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1226 AM CDT SAT OCT 5 2013
WIDESPREAD SNOW IN NORTHWEST NEBRASKA WILL CONTINUE TONIGHT. IN
BBW...LIGHT SNOW IS POSSIBLE BUT LITTLE ACCUMULATION IS EXPECTED.
FOR LBF...OGA AND IML...THE PROBABILITY OF PRECIPITATION IN
EITHER FORM IS LOW.
CLEAR SKY IN SOUTHWEST NEBRASKA IS LIKELY TO BECOME OVERCAST
AGAIN BY 08Z...BUT THE CEILING IS LIKELY BE ABOVE 3000 FEET AGL.
OTHERWISE...WIND WILL CONTINUE TO BE A CONCERN THROUGH AT LEAST
SATURDAY AFTERNOON WITH 310-340 AT 24-28G35-38KT IN THE
MORNING...INCREASING TO 32-36G40-44KT BY 15Z OR 16Z AS THE STORM
SYSTEM MOVES OUT AND A BLAST OF CANADIAN AIR POURS IN BEHIND IT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NEZ008-
022>027-035>038-056>059-069>071.
WINTER WEATHER ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR NEZ005.
WINTER STORM WARNING UNTIL NOON MDT TODAY FOR NEZ004-094.
WIND ADVISORY FROM 10 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR NEZ006-007-009-010-028-029.
&&
$$
SYNOPSIS...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1135 PM MDT FRI OCT 4 2013
.AVIATION...
06Z TAF CYCLE
VFR CIGS AND VIZ NEXT 24 HRS. WEATHER SYSTEM CORE EJECTING INTO
SOUTH DAKOTA WITH BROAD INTENSE CIRCULATION ALOFT PUSHING WESTERLY
WINDS ACROSS NEW MEXICO...AND THESE WILL SHIFT RAPIDLY NORTHERLY
BY 00Z SAT EVENING. CLOUD COVER AOA BKN/OVC100 ACROSS THE HEART OF
NEW MEXICO WILL EJECT RAPIDLY TO THE NORTHEAST THROUGH 15Z SAT
MORNING WITH NEXT ROUND OF GUSTS REDEVELOPING FROM 16Z ONWARD
ACROSS WESTERN AND CENTRAL PORTIONS OF THE STATE. WIND SPEEDS
DROPPING OFF AFTER 03Z SATURDAY EVENING.
SHY
&&
.PREV DISCUSSION...315 PM MDT FRI OCT 4 2013...
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 DEW POINTS 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 MORE SO 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 AIR MASS 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.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING UNTIL 9 AM MDT SATURDAY FOR THE FOLLOWING ZONES...
NMZ518-519-524-530>534.
&&
$$
33
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1136 PM EDT SUN OCT 6 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH FROM THE WEST OVERNIGHT. THIS FRONT
WILL BRING A PERIOD OF HEAVY RAIN AND GUSTY WINDS AS IT CROSSES THE
AREA MONDAY WITH A SHARP DROP IN TEMPERATURES IN ITS WAKE. A BRIEF
PERIOD OF COOL AND CLOUDY WEATHER TUESDAY WILL GIVE WAY TO
INCREASING SUNSHINE ALONG WITH TEMPERATURES THAT WILL GRADUALLY WARM
ABOVE NORMAL AS HIGH PRESSURE SETTLES IN ACROSS THE LOWER GREAT
LAKES FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
A STRONG COLD FRONT IS LOCATED FROM SOUTHERN ONTARIO TO EASTERN OHIO
AS OF 1130PM. RADARS SHOW A BAND OF SHOWERS WITH EMBEDDED THUNDERSTORMS
ALONG THE LEADING EDGE OF THE FRONT. A SOUTHERLY LOW LEVEL JET AHEAD
OF THE FRONT IS KEEPING THE WARM TEMPERATURES OBSERVED ACROSS
WESTERN AND CENTRAL NEW YORK ALONG WITH GUSTY WINDS ACROSS THE
HILLTOPS AND DOWNSLOPE AREAS EAST OF LAKE ERIE AND ACROSS THE NORTH
COUNTY WHERE GUSTS HAVE REACHED AROUND 30 MPH. MODELS SHOW THE JET
INCREASING TO 50+ KNOTS AT 925MB WHICH COULD BRING SOME GUSTS TO 40
OR 45 MPH BUT LIKELY REMAINING JUST BELOW WIND ADVISORY CRITERIA.
LATEST HRRR SURFACE WIND GUSTS NO HIGHER THAN 35 KTS MAINLY OVER THE
EASTERN END OF LAKE ONTARIO.
THE COLD FRONT WILL BRING HEAVY RAINS AND EMBEDDED THUNDERSTORMS
ACROSS WESTERN NEW YORK BEGINNING LATE TONIGHT THEN SHIFTING TOWARD
CENTRAL NEW YORK LATE MORNING OR EARLY AFTERNOON. WIDESPREAD AVERAGE
RAINFALL AMOUNTS OF AROUND HALF AN INCH EXPECTED WITH HIGHER AMOUNTS
POSSIBLE IN CONVECTION. THE ONLY REASON HIGHER AVERAGE AMOUNTS ARE
NOT EXPECTED WILL BE BY VIRTUE OF THE SPEED OF THE FRONT CROSSING THE
REGION AS THE UPPER LEVEL LOW RAPIDLY LIFTS NORTHEAST INTO EASTERN
CANADA. FOLLOWING THE FRONTAL PASSAGE A SHIFT TO STRONG
WEST-SOUTHWESTERLY WINDS IS EXPECTED. 850MB WINDS ARE PROGGED TO BE
IN THE 40-45KT RANGE...PROBABLY A LITTLE TOO WEAK TO HIT ADVISORY
LEVEL CRITERIA...HOWEVER WIDESPREAD GUSTS TO 35-39KT ARE NOT OUT OF
THE QUESTION. TEMPERATURES WILL FALL SHARPLY BEHIND THE FRONT INTO
THE 50S. THE COOLER AIR COUPLED WITH A REASONABLY WELL ALIGNED
SOUTHWESTERLY WIND PROFILE DOWN LAKE ERIE COULD RESULT IN LAKE
EFFECT RAIN SHOWERS DEVELOPING THIS AFTERNOON.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
TO START THIS TIME PERIOD THE 12Z DETERMINISTIC MODELS OF THE
NAM/GFS/ECMWF/CMC ALL BRING THE COLD FRONT THROUGH THE REGION TO
START MONDAY EVENING. WHILE THE HEAVY RAIN ALONG THE FRONT WILL
LIKELY BE JUST TO OUR EAST...THERE WILL STILL BE SOME TRAILING
SHOWERS AS A SECONDARY TROUGH PASSES THROUGH THE REGION...AND MORE
LIKELY SOME LAKE EFFECT RAIN AS TEMPERATURES AT 850 HPA DROP TO
AROUND +2 TO +3C OVER THE LAKES. LAKE RAINS WILL BE MOST PREVALENT
THROUGH THE EVENING HOURS BEFORE DRIER AIR ENTRAINS...AND A VEERING
WIND BEHIND SHIFTS BANDS SOUTHEASTWARD AS THEY DISSIPATE. WINDS WILL
STILL BE BRISK BEHIND THE FRONT MONDAY NIGHT WITH STRONGEST WINDS
FELT NEAR THE SHORELINES OF THE GREAT LAKES.
TUESDAY AND TUESDAY NIGHT LOOK TO BE DRY AS HIGH PRESSURE NEARS THE
REGION. WITH MOISTURE DEPLETING BEHIND THIS SECONDARY TROUGH WE
SHOULD SEE SKIES BECOME MOSTLY SUNNY BY TUESDAY AFTERNOON. LINGERING
MOISTURE MAY START THE DAY WITH SOME CLOUDS BUT WARM AIR ADVECTION
AND RISING HEIGHTS SHOULD ALLOW FOR DAYTIME MIXING ERODING ANY
LINGERING MORNING CLOUDS. BEHIND THIS COLD FRONT TEMPERATURES
TUESDAY EVEN WITH THE SUNSHINE WILL RISE ONLY INTO THE UPPER 50S TO
LOWERS 60S...WHICH IS ACTUALLY NORMAL FOR THIS TIME OF YEAR...BUT
MAY FEEL CHILLY SINCE THE LAST WEEK OR SO HAS BEEN QUITE WARM.
TUESDAY NIGHT SOME VALLEY FOG IS POSSIBLE THROUGH THE RIVER VALLEYS
OF THE SOUTHERN TIER AS HIGH PRESSURE CAMPED OVER THE REGION
PROVIDES EXCELLENT RADIATIONAL COOLING CONDITIONS. LOWS WILL DROP
BACK INTO THE LOWER 40S TO 30S WITH THE STAR LITE SKIES AND SOME
AREAS OF FROST ARE POSSIBLE THROUGH THE SOUTHERN
TIER...WYOMING...LIVINGSTON AS WELL AS THE EASTERN LAKE ONTARIO
REGION.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ANOTHER EXTENDED PERIOD OF DRY WEATHER IS EXPECTED THROUGH THIS TIME
PERIOD AS A LARGE SCALE TROUGH AND COLD FRONT WILL HAVE SWEPT THE
HUMIDITY EASTWARD ALLOWING FOR SURFACE HIGH PRESSURE FROM THE
CENTRAL PLAINS TO EXPAND EASTWARD TOWARDS THE EAST COASTLINE. WITHIN
THIS AIRMASS OUR TEMPERATURES ALOFT AT 850 HPA WILL CLIMB INTO THE
12 TO 14C RANGE WHICH WILL ALLOW FOR HIGHS TO BE SLIGHTLY ABOVE
NORMAL. WHILE A RIDGE ALOFT WILL EXTEND FROM THE TENNESSEE VALLEY
NORTHEASTWARD ACROSS THE EASTERN GREAT LAKES REGION...TROUGHINESS
ALONG THE EASTERN SEABOARD WILL MAINTAIN UNSETTLED WEATHER. EXACT
TIMING AND PLACEMENT OF AN EASTCOAST DISTURBANCE IS STILL
UNCERTAIN...THOUGH THERE IS A SMALL POSSIBILITY THAT LATE IN THE
EXTENDED PERIOD SOME ATLANTIC MOISTURE MAY BE THROWN WESTWARD ACROSS
OUR EASTERN ZONES. FOR NOW WILL JUST KEEP DRY FORECAST...BUT ALLOW
FOR SOME CLOUDS ACROSS EASTERN ZONES. A NEARING COLD FRONT FROM THE
WEST SHOULD DIMINISH AS IT ENCOUNTERS A RIBBON OF DRY AIR...HIGH
PRESSURE SUBSIDENCE THAT WILL BE ANCHORED OVER OUR REGION AND
BETWEEN THE WESTERN ATLANTIC DISTURBANCE.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
A 40-50KT LOW LEVEL JET IS CROSSING THE REGION TONIGHT AHEAD OF AN
APPROACHING COLD FRONT FOUND JUST TO THE WEST OF NEW YORK. RADAR
WIND PROFILES SHOWING THESE SOUTHERLY WINDS 2-3KFT OFF THE SURFACE
WHICH CONFIRMS THAT LLWS IS PRESENT ACROSS ALL WESTERN TAFS. THIS
LOW LEVEL JET HAS BROUGHT GUSTY WINDS TO KART WITH LESS OF CHANCE OF
STRONG WIND SHEAR IS SURFACE WINDS ARE ALREADY GUSTY.
THE COLD FRONT WILL CROSS INTO THE NIAGARA FRONTIER CLOSE TO
DAYBREAK MONDAY AND RAPIDLY MARCH ACROSS THE REST OF NEW YORK DURING
THE DAY MONDAY. THE FRONT WILL BE ACCOMPANIED BY HEAVY RAIN AND
POSSIBLY SOME LIGHTNING. VSBYS IN THIS HEAVY RAIN COULD FALL TO IFR
AT TIMES ALONG/JUST AHEAD OF THE FRONT WITH CIGS ONLY DOWN TO MVFR.
EXPECT A SHARP WIND SHIFT TO THE WEST-SOUTHWEST BEHIND THE FRONT. A
PERIOD OF LAKE EFFECT RAIN SHOWERS IS POSSIBLE DOWNSTREAM OF LAKE
ERIE ACROSS THE NIAGARA FRONTIER BEHIND THE FRONT.
OUTLOOK...
MONDAY NIGHT...MVFR.
TUESDAY...MVFR IMPROVING TO VFR.
WEDNESDAY THROUGH FRIDAY...VFR. SOME PATCHY MORNING IFR VSBYS IN VALLEY
FOG.
&&
.MARINE...
SOUTHERLY WINDS ARE INCREASING AHEAD OF AN APPROACHING COLD FRONT
TONIGHT RESULTING IN INCREASING WINDS/WAVES ON THE EAST END OF LAKE
ONTARIO. THE COLD FRONT WILL CROSS THE LAKES FROM EARLY MONDAY
MORNING THROUGH THE REST OF THE DAY. HEAVY RAINS AND POSSIBLE
LIGHTNING WILL BE FOLLOWED BY SHARPLY INCREASING SOUTHWESTERLIES
BEHIND THE FRONT THAT WILL RAPIDLY PUSH WAVES AS HIGH AS 8 FEET ON
LAKE ERIE AND 11 FEET ON LAKE ONTARIO MONDAY NIGHT. THESE WINDS WILL
ALSO CAUSE CHOPPY CONDITIONS DOWN THE SAINT LAWRENCE RIVER. WHILE
WINDS SHOULD REMAIN BELOW GALE FORCE OVER THE LAKES...GUSTS
APPROACHING GALE MAY BE POSSIBLE DURING THIS PERIOD. WINDS AND WAVES
SHOULD RAPIDLY SUBSIDE ON TUESDAY HOWEVER AS HIGH PRESSURE MOVES
OVER THE LOWER GREAT LAKES WITH GENERALLY TRANQUIL CONDITIONS
PREVAILING THROUGH THE REMAINDER OF THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM MONDAY TO 8 AM EDT TUESDAY FOR
LEZ040-041.
SMALL CRAFT ADVISORY FROM 8 AM TO 10 PM EDT MONDAY FOR
LEZ020.
SMALL CRAFT ADVISORY FROM 2 PM MONDAY TO 11 AM EDT
TUESDAY FOR LOZ042-043.
SMALL CRAFT ADVISORY UNTIL 3 PM EDT TUESDAY FOR LOZ045.
SMALL CRAFT ADVISORY FROM 5 PM MONDAY TO 3 PM EDT TUESDAY
FOR LOZ044.
SMALL CRAFT ADVISORY FROM 2 PM MONDAY TO 2 AM EDT
TUESDAY FOR SLZ022-024.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...SMITH
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...SMITH
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
255 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN OVER THE REGION THROUGH TONIGHT
THEN LIFT NORTH AS A WARM FRONT ON SUNDAY. THIS WILL KEEP OUR
WEATHER UNSETTLED THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS, PRIMARILY DURING THE DAYLIGHT HOURS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
1155 AM UPDATE...CURRENT SFC ANALYSIS SHOWS STATIONARY FRONT
SLIGHTLY FURTHER SOUTH THEN YESTERDAY. ATTM IT STRETCHES ACROSS
THE SOUTHERN TIER OF NYS THEN DROPS SOUTHEAST INTO THE POCONOS.
CONVECTION OVER THE NRN FINGER LAKES REGION HAS ALMOST DISSIPATED
AS IT ENCOUNTERED A FAIRLY STABLE AIRMASS WELL NORTH OF THE
BOUNDARY. SATELLITE SHOWS STRATUS BEGINNING TO MIX OUT OVER NE PA
AND THE SOUTHERN TIER. THESE LOCATIONS WILL SEE SOME SUNNY BREAKS
THIS AFTERNOON WITH THE WYOMING VALLEY LIKELY TO SEE THE MOST
SUNSHINE. MODELS CONTINUE TO SUGGEST A WEAK SHORT WAVE WILL MOVE
ALONG THE BOUNDARY LATER THIS AFTERNOON AND INTO THE EARLY EVENING.
CURRENT POPS LOOK REASONABLE WITH ONLY MINOR ADJUSTMENTS. ISOLATED
THUNDER IS STILL POSSIBLE LATER TODAY ALONG AND SOUTH OF THE SFC
FEATURE.
915 AM UPDATE...LOCAL RADAR SHOWS A CLUSTER OF SHOWERS WITH
EMBEDDED ISOLATED THUNDER MOVING INTO THE FINGER LAKES REGION.
BASED ON CURRENT MOVEMENT AND HRRR OUTPUT THIS CLUSTER WILL MOVE
ACROSS THE FINGER LAKES REGION AND INTO THE NRN CWA THROUGH LATE
MORNING. INCREASED POPS IN THE ABOVE MENTIONED AREAS AND INCLUDED
ISOLATED T EXCEPT FAR NRN CWA WHERE MODEL SOUNDINGS INDICATE NO
INSTABILITY. REST OF FORECAST IN GOOD SHAPE.
620 AM UPDATE...
TEMPS HV STAYED UP IN THE 60S UNDER EXTENSIVE STRATUS AND FOG
DECK. EXPECT PATCHY DENSE FOG WL CONTINUE THRU 14Z ALONG WITH
ISOLD SHOWERS WITH STATIONARY FRONT LURKING ACRS THE AREA. AREA OF
SHOWERS MVG INTO NIAGARA FRONTIER AHD OF S/WV MAY MV INTO WRN
CNTYS TWD 12Z. KEPT SLGT CHC POPS IN ALL NIGHT FOR CNTRL CNTYS AND
EXPECT POPS TO INCRS IN CVRG ACRS TWIN TIERS TWD LATE MRNG. THUS
NO CHGS NEEDED AT THIS TIME OTHER THAN T/TD GRIDS TO COME MORE
INTO LINE WITH REALITY.
PREV DISCUSSION BLO...
330 AM UPDATE...
WMFNT IS CURRENTLY STRETCHED FM SFC LOW NR PIERRE SD ALONG THE I-90
CORRIDOR TO BTWN KBUF AND KERI AND ALONG NY/PA BORDER. DO NOT EXPECT
MUCH IN THE WAY OF MVMNT TDA AS 1028MB HIPRES RMNS LOCKED ACRS ERN
CANADA AND CLOSED LOW JUST CREEPS ALONG, ROUGHLY 100 MILES IN 12
HRS, AS IT WAITS FOR AN UPSTREAM KICKER.
AS FOR TDA`S FCST EXPECT ISOLD/SCTD CONVECTION AS WMFNT RMNS OVR
AREA. ISOLD SHOWERS EXPECTED UNTIL ABOUT NOON TDA AS ANY EMBEDDED
S/WVS MAY KICK SOMETHING OFF WITH FRONTAL BNDRY IN AREA. HWVR AFT
ABOUT 16Z INSTABILITY LOOKS TO NOSE INTO REGION MAINLY ALONG BNDRY
WITH CAPES BTWN 200-400 J/KG AND K-INDICES APPCHG 35. EXPECT
CONVECTION AFT THIS TIME ACRS THE SRN TIER/SUSQ REGION, THEN SOUTH
INTO NEPA AFT 18Z. NRN CNTYS EXPECTED TO BE SOCKED IN WITH LOCLDS
ALL DAY NORTH OF THE BNDRY SIMILAR TO YDA. THUS HV NOT ADDED ANY
THUNDER INTO ZONES ALONG AND NORTH OF THE NY THRUWAY AT THIS TIME.
SKIES EXPECTED TO RMN CLDY ACRS NRN AREAS WITH SOME SUN POSSIBLY
BREAKING OUT BRIEFLY ACRS THE SOUTH. EXPECT AFTN MAXES SIMILAR TO
YDA WITH HIGHS ARND 80 ACRS WRN AND SRN ZONES AND ONLY INTO THE 60S
OVR NE CNTYS.
FNT WL BEGIN LIFTING NORTH SAT NGT AS HIPRES BUILDS INTO THE
CANADIAN MARITIMES AND SRLY WINDS INCRS. EXPECT SLGT/CHC SHOWERS
THRU THE OVRNGT ACRS CWA, INCRSG TO LKLY TWD SUN MRNG ACRS NRN ZONES
AS EJECTING WV FM UPSTREAM CLOSED LOW RIDES ALONG FRONTAL BNDRY AND
INITIATES CONVECTION.
OVRNGT LOWS FOR SUN MRNG WL LKLY RMN ARND NRML VALUES (L/M 60S) FOR
HIGHS THIS TIME OF YR, NOT EVEN CLOSE TO NORMAL LOWS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
330 AM UPDATE...
CWA WL BE IN WM SECTOR ON SUNDAY WITH SCTD CONVECTION EXPECTED OFF
AND ON THROUGHOUT THE DAY AS ANY SUBTLE WVS THAT CAN MV THRU WL
GENERATE CHCS FOR SHRA/TSRA. FOR NOW, HV NOT MADE MANY CHGS DUE TO
UNSETTLED PATTERN AND DIFFICULTY RESOLVING ANY TRIGGERS.
AREA RMNS IN WARM SECTOR ON SUN NGT AND CAN EXPECT JUST CHC SHOWERS
THRU 12Z MON SO HV DROPPED POPS TO JUST 30% AT THIS TIME FOR THE PD.
WARM AND HUMID CONDS WL CONT THRU MON MRNG WITH TEMPS AND TDS IN THE
U50S/L60S.
MOISTURE FM TROPICAL STORM KAREN PROGGED BY GFS TO WORK UP INTO AREA
MON NGT. HWVR, THIS WL ALL DEPEND ON HOW MUCH H5 SYSTEM SLOWS DOWN
AND IF FRONTAL BNDRY CAN HOLD OFF ENUF TO BRING MOISTURE INTO AREA.
AS OF NOW WITH PW VALUES INCRSG TO BTWN 1.5 AND 1.75 INCHES ON MON
NGT EXPECTED 12-HR QPF VALUES FM HPC WL AVG ARND 1 INCH THRU THE END
OF THE SHORT TERM. FROPA LOOKS TO HV SLOWED DOWN ENUF TO OCCUR AT
THE VRY TAIL END OF THE SHORT TERM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
240 PM EDT UPDATE...
A MUCH DRIER WEATHER PATTERN IS EXPECTED IN THE EXTENDED THAN IN
THE NEAR TERM. THE UPPR 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 /19Z SATURDAY THROUGH THURSDAY/...
140 PM EDT UPDATE...
A VERY CHALLENGING FORECAST IS IN STORE FOR THE NEXT 24 HOURS AS A
WARM FRONT LIFTS NORTH FROM THE BORDER OF PA TO NORTHERN NY.
CURRENTLY ACROSS THE REGION A VERY DENSE MVFR STRATUS DECKS LIES
ACROSS MUCH OF CENTRAL NY. DUE TO HEATING FROM THE SUN...WE DO
EXPECT THESE CLOUDS TO LIFT BRIEFLY TO VFR THIS AFTERNOON/EVENING.
CONFIDENCE IS NOT HIGH ON THE TIMING OF THE TRANSITION. THERE IS A
CHANCE FOR LIGHT RAIN SHOWERS THIS AFTERNOON...BUT WITHOUT STRONG
UPPER FORCING DECIDED TO KEEP OUT OF TAFS DUE TO UNCERTAINTY OF
LOCATION. THE OVERALL CHANCE FOR RAIN SHOWERS WILL INCREASE AFTER
00Z TONIGHT AS THE DRAPED WARM FRONT MOVES NORTH. THE BEST CHANCES
FOR RAIN ARE AT KRME... KITH... AND KSYR. THESE SHOWERS MAY PERSIST
WELL INTO THE AFTERNOON ON SUNDAY AND EXPECT THESE SHOWERS TO BE
FUEL ALTERNATE CIGS AND VISBYS.
OUTLOOK...
SUNDAY THROUGH THURSDAY...AN UNSETTLED PERIOD...WITH SCATTERED
TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF
RESTRICTIVE CONDS FROM TIME TO TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...KAH
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
158 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN OVER THE REGION THROUGH TONIGHT
THEN LIFT NORTH AS A WARM FRONT ON SUNDAY. THIS WILL KEEP OUR
WEATHER UNSETTLED THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS, PRIMARILY DURING THE DAYLIGHT HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
1155 AM UPDATE...CURRENT SFC ANALYSIS SHOWS STATIONARY FRONT
SLIGHTLY FURTHER SOUTH THEN YESTERDAY. ATTM IT STRETCHES ACROSS
THE SOUTHERN TIER OF NYS THEN DROPS SOUTHEAST INTO THE POCONOS.
CONVECTION OVER THE NRN FINGER LAKES REGION HAS ALMOST DISSIPATED
AS IT ENCOUNTERED A FAIRLY STABLE AIRMASS WELL NORTH OF THE
BOUNDARY. SATELLITE SHOWS STRATUS BEGINNING TO MIX OUT OVER NE PA
AND THE SOUTHERN TIER. THESE LOCATIONS WILL SEE SOME SUNNY BREAKS
THIS AFTERNOON WITH THE WYOMING VALLEY LIKELY TO SEE THE MOST
SUNSHINE. MODELS CONTINUE TO SUGGEST A WEAK SHORT WAVE WILL MOVE
ALONG THE BOUNDARY LATER THIS AFTERNOON AND INTO THE EARLY EVENING.
CURRENT POPS LOOK REASONABLE WITH ONLY MINOR ADJUSTMENTS. ISOLATED
THUNDER IS STILL POSSIBLE LATER TODAY ALONG AND SOUTH OF THE SFC
FEATURE.
915 AM UPDATE...LOCAL RADAR SHOWS A CLUSTER OF SHOWERS WITH
EMBEDDED ISOLATED THUNDER MOVING INTO THE FINGER LAKES REGION.
BASED ON CURRENT MOVEMENT AND HRRR OUTPUT THIS CLUSTER WILL MOVE
ACROSS THE FINGER LAKES REGION AND INTO THE NRN CWA THROUGH LATE
MORNING. INCREASED POPS IN THE ABOVE MENTIONED AREAS AND INCLUDED
ISOLATED T EXCEPT FAR NRN CWA WHERE MODEL SOUNDINGS INDICATE NO
INSTABILITY. REST OF FORECAST IN GOOD SHAPE.
620 AM UPDATE...
TEMPS HV STAYED UP IN THE 60S UNDER EXTENSIVE STRATUS AND FOG
DECK. EXPECT PATCHY DENSE FOG WL CONTINUE THRU 14Z ALONG WITH
ISOLD SHOWERS WITH STATIONARY FRONT LURKING ACRS THE AREA. AREA OF
SHOWERS MVG INTO NIAGARA FRONTIER AHD OF S/WV MAY MV INTO WRN
CNTYS TWD 12Z. KEPT SLGT CHC POPS IN ALL NIGHT FOR CNTRL CNTYS AND
EXPECT POPS TO INCRS IN CVRG ACRS TWIN TIERS TWD LATE MRNG. THUS
NO CHGS NEEDED AT THIS TIME OTHER THAN T/TD GRIDS TO COME MORE
INTO LINE WITH REALITY.
PREV DISCUSSION BLO...
330 AM UPDATE...
WMFNT IS CURRENTLY STRETCHED FM SFC LOW NR PIERRE SD ALONG THE I-90
CORRIDOR TO BTWN KBUF AND KERI AND ALONG NY/PA BORDER. DO NOT EXPECT
MUCH IN THE WAY OF MVMNT TDA AS 1028MB HIPRES RMNS LOCKED ACRS ERN
CANADA AND CLOSED LOW JUST CREEPS ALONG, ROUGHLY 100 MILES IN 12
HRS, AS IT WAITS FOR AN UPSTREAM KICKER.
AS FOR TDA`S FCST EXPECT ISOLD/SCTD CONVECTION AS WMFNT RMNS OVR
AREA. ISOLD SHOWERS EXPECTED UNTIL ABOUT NOON TDA AS ANY EMBEDDED
S/WVS MAY KICK SOMETHING OFF WITH FRONTAL BNDRY IN AREA. HWVR AFT
ABOUT 16Z INSTABILITY LOOKS TO NOSE INTO REGION MAINLY ALONG BNDRY
WITH CAPES BTWN 200-400 J/KG AND K-INDICES APPCHG 35. EXPECT
CONVECTION AFT THIS TIME ACRS THE SRN TIER/SUSQ REGION, THEN SOUTH
INTO NEPA AFT 18Z. NRN CNTYS EXPECTED TO BE SOCKED IN WITH LOCLDS
ALL DAY NORTH OF THE BNDRY SIMILAR TO YDA. THUS HV NOT ADDED ANY
THUNDER INTO ZONES ALONG AND NORTH OF THE NY THRUWAY AT THIS TIME.
SKIES EXPECTED TO RMN CLDY ACRS NRN AREAS WITH SOME SUN POSSIBLY
BREAKING OUT BRIEFLY ACRS THE SOUTH. EXPECT AFTN MAXES SIMILAR TO
YDA WITH HIGHS ARND 80 ACRS WRN AND SRN ZONES AND ONLY INTO THE 60S
OVR NE CNTYS.
FNT WL BEGIN LIFTING NORTH SAT NGT AS HIPRES BUILDS INTO THE
CANADIAN MARITIMES AND SRLY WINDS INCRS. EXPECT SLGT/CHC SHOWERS
THRU THE OVRNGT ACRS CWA, INCRSG TO LKLY TWD SUN MRNG ACRS NRN ZONES
AS EJECTING WV FM UPSTREAM CLOSED LOW RIDES ALONG FRONTAL BNDRY AND
INITIATES CONVECTION.
OVRNGT LOWS FOR SUN MRNG WL LKLY RMN ARND NRML VALUES (L/M 60S) FOR
HIGHS THIS TIME OF YR, NOT EVEN CLOSE TO NORMAL LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
330 AM UPDATE...
CWA WL BE IN WM SECTOR ON SUNDAY WITH SCTD CONVECTION EXPECTED OFF
AND ON THROUGHOUT THE DAY AS ANY SUBTLE WVS THAT CAN MV THRU WL
GENERATE CHCS FOR SHRA/TSRA. FOR NOW, HV NOT MADE MANY CHGS DUE TO
UNSETTLED PATTERN AND DIFFICULTY RESOLVING ANY TRIGGERS.
AREA RMNS IN WARM SECTOR ON SUN NGT AND CAN EXPECT JUST CHC SHOWERS
THRU 12Z MON SO HV DROPPED POPS TO JUST 30% AT THIS TIME FOR THE PD.
WARM AND HUMID CONDS WL CONT THRU MON MRNG WITH TEMPS AND TDS IN THE
U50S/L60S.
MOISTURE FM TROPICAL STORM KAREN PROGGED BY GFS TO WORK UP INTO AREA
MON NGT. HWVR, THIS WL ALL DEPEND ON HOW MUCH H5 SYSTEM SLOWS DOWN
AND IF FRONTAL BNDRY CAN HOLD OFF ENUF TO BRING MOISTURE INTO AREA.
AS OF NOW WITH PW VALUES INCRSG TO BTWN 1.5 AND 1.75 INCHES ON MON
NGT EXPECTED 12-HR QPF VALUES FM HPC WL AVG ARND 1 INCH THRU THE END
OF THE SHORT TERM. FROPA LOOKS TO HV SLOWED DOWN ENUF TO OCCUR AT
THE VRY TAIL END OF THE SHORT TERM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
345 AM UPDATE...
MED RNG GRIDS UPDATED WITH 00Z WPC GDNC (BLENDED WITH SOME GFS/MOS
DATA) TO REFLECT A SLOWER MVMNT OF THE UPR LOW...WITH AN EXTENSION OF
CHC POPS INTO MID WEEK AND MORE IN THE WAY OF CLDS DUE TO THIS
SYSTEM. PREV BLO...
2 PM UPDATE...
MAIN INTEREST IN THE LONG TERM FORECAST WILL BE THE POTENTIAL FOR
HEAVY RAIN MONDAY NIGHT. THE MAIN WEATHER PLAYERS WILL BE AN UPPER
LEVEL LOW NOW OVER SE WYOMING...AND ASSOCIATED COLD FRONT OVER THE
CENTRAL PLAINS. AS THESE FEATURES MOVE EAST THE SOUTHERLY FLOW OF
AIR AHEAD OF THEM WILL TRANSPORT MOISTURE...SOME OF IT WILL BE
WHATS LEFT OF TS KAREN...NORTHWARD INTO OUR AREA. WITH HIGH
VARIANCE IN THE MODELS JUST 24 HOURS AGO...THE 12Z NAM AND GFS ARE
FAIRLY SIMILAR IN SHOWING AN AREA OF STEADY RAIN ALONG AND AHEAD
OF THE COLD FRONT MOVING INTO OUR AREA MONDAY EVENING. BOTH THE
GFS AND WPC GUIDANCE SHOW A GENERAL 1" TO 2" RAIN ACROSS THE AREA
MONDAY NIGHT...WITH ISOLATED HIGHER AMOUNTS POSSIBLE. WITH OUR
RECENT STRETCH OF DRY WEATHER AND THE PROGRESSIVE NATURE OF THE
FRONT (RAIN FALLING IN 12 HOURS OR LESS)...WIDESPREAD PROBLEMS ARE
NOT EXPECTED AT THIS EARLY JUNCTURE. IN FACT FOR MOST THIS WILL BE
A WELCOME BENEFICIAL FALL RAIN.
LATER TUESDAY AND BEYOND...THE GFS IS NOW THE SLOWEST WITH THE
UPPER LEVEL LOW MOVING OVER OUR AREA AND KEEPING US
CLOUDY/UNSETTLED FOR ONE MORE DAY. WILL LEAN WITH WPC GUIDANCE
DRYING US OUT BY TUESDAY NIGHT. HIGH PRESSURE CONTROLS THE REST OF
THE PERIOD WITH QUIET WEATHER EXPECTED.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
140 PM EDT UPDATE...
A VERY CHALLENGING FORECAST IS IN STORE FOR THE NEXT 24 HOURS AS A
WARM FRONT LIFTS NORTH FROM THE BORDER OF PA TO NORTHERN NY.
CURRENTLY ACROSS THE REGION A VERY DENSE MVFR STRATUS DECKS LIES
ACROSS MUCH OF CENTRAL NY. DUE TO HEATING FROM THE SUN...WE DO
EXPECT THESE CLOUDS TO LIFT BRIEFLY TO VFR THIS AFTERNOON/EVENING.
CONFIDENCE IS NOT HIGH ON THE TIMING OF THE TRANSITION. THERE IS A
CHANCE FOR LIGHT RAIN SHOWERS THIS AFTERNOON...BUT WITHOUT STRONG
UPPER FORCING DECIDED TO KEEP OUT OF TAFS DUE TO UNCERTAINTY OF
LOCATION. THE OVERALL CHANCE FOR RAIN SHOWERS WILL INCREASE AFTER
00Z TONIGHT AS THE DRAPED WARM FRONT MOVES NORTH. THE BEST CHANCES
FOR RAIN ARE AT KRME... KITH... AND KSYR. THESE SHOWERS MAY PERSIST
WELL INTO THE AFTERNOON ON SUNDAY AND EXPECT THESE SHOWERS TO BE
FUEL ALTERNATE CIGS AND VISBYS.
OUTLOOK...
SUNDAY THROUGH THURSDAY...AN UNSETTLED PERIOD...WITH SCATTERED
TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF
RESTRICTIVE CONDS FROM TIME TO TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1155 AM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN OVER THE REGION THROUGH TONIGHT
THEN LIFT NORTH AS A WARM FRONT ON SUNDAY. THIS WILL KEEP OUR
WEATHER UNSETTLED THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS, PRIMARILY DURING THE DAYLIGHT HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
1155 AM UPDATE...CURRENT SFC ANALYSIS SHOWS STATIONARY FRONT
SLIGHTLY FURTHER SOUTH THEN YESTERDAY. ATTM IT STRETCHES ACROSS
THE SOUTHERN TIER OF NYS THEN DROPS SOUTHEAST INTO THE POCONOS.
CONVECTION OVER THE NRN FINGER LAKES REGION HAS ALMOST DISSIPATED
AS IT ENCOUNTERED A FAIRLY STABLE AIRMASS WELL NORTH OF THE
BOUNDARY. SATELLITE SHOWS STRATUS BEGINNING TO MIX OUT OVER NE PA
AND THE SOUTHERN TIER. THESE LOCATIONS WILL SEE SOME SUNNY BREAKS
THIS AFTERNOON WITH THE WYOMING VALLEY LIKELY TO SEE THE MOST
SUNSHINE. MODELS CONTINUE TO SUGGEST A WEAK SHORT WAVE WILL MOVE
ALONG THE BOUNDARY LATER THIS AFTERNOON AND INTO THE EARLY EVENING.
CURRENT POPS LOOK REASONABLE WITH ONLY MINOR ADJUSTMENTS. ISOLATED
THUNDER IS STILL POSSIBLE LATER TODAY ALONG AND SOUTH OF THE SFC
FEATURE.
915 AM UPDATE...LOCAL RADAR SHOWS A CLUSTER OF SHOWERS WITH
EMBEDDED ISOLATED THUNDER MOVING INTO THE FINGER LAKES REGION.
BASED ON CURRENT MOVEMENT AND HRRR OUTPUT THIS CLUSTER WILL MOVE
ACROSS THE FINGER LAKES REGION AND INTO THE NRN CWA THROUGH LATE
MORNING. INCREASED POPS IN THE ABOVE MENTIONED AREAS AND INCLUDED
ISOLATED T EXCEPT FAR NRN CWA WHERE MODEL SOUNDINGS INDICATE NO
INSTABILITY. REST OF FORECAST IN GOOD SHAPE.
620 AM UPDATE...
TEMPS HV STAYED UP IN THE 60S UNDER EXTENSIVE STRATUS AND FOG
DECK. EXPECT PATCHY DENSE FOG WL CONTINUE THRU 14Z ALONG WITH
ISOLD SHOWERS WITH STATIONARY FRONT LURKING ACRS THE AREA. AREA OF
SHOWERS MVG INTO NIAGARA FRONTIER AHD OF S/WV MAY MV INTO WRN
CNTYS TWD 12Z. KEPT SLGT CHC POPS IN ALL NIGHT FOR CNTRL CNTYS AND
EXPECT POPS TO INCRS IN CVRG ACRS TWIN TIERS TWD LATE MRNG. THUS
NO CHGS NEEDED AT THIS TIME OTHER THAN T/TD GRIDS TO COME MORE
INTO LINE WITH REALITY.
PREV DISCUSSION BLO...
330 AM UPDATE...
WMFNT IS CURRENTLY STRETCHED FM SFC LOW NR PIERRE SD ALONG THE I-90
CORRIDOR TO BTWN KBUF AND KERI AND ALONG NY/PA BORDER. DO NOT EXPECT
MUCH IN THE WAY OF MVMNT TDA AS 1028MB HIPRES RMNS LOCKED ACRS ERN
CANADA AND CLOSED LOW JUST CREEPS ALONG, ROUGHLY 100 MILES IN 12
HRS, AS IT WAITS FOR AN UPSTREAM KICKER.
AS FOR TDA`S FCST EXPECT ISOLD/SCTD CONVECTION AS WMFNT RMNS OVR
AREA. ISOLD SHOWERS EXPECTED UNTIL ABOUT NOON TDA AS ANY EMBEDDED
S/WVS MAY KICK SOMETHING OFF WITH FRONTAL BNDRY IN AREA. HWVR AFT
ABOUT 16Z INSTABILITY LOOKS TO NOSE INTO REGION MAINLY ALONG BNDRY
WITH CAPES BTWN 200-400 J/KG AND K-INDICES APPCHG 35. EXPECT
CONVECTION AFT THIS TIME ACRS THE SRN TIER/SUSQ REGION, THEN SOUTH
INTO NEPA AFT 18Z. NRN CNTYS EXPECTED TO BE SOCKED IN WITH LOCLDS
ALL DAY NORTH OF THE BNDRY SIMILAR TO YDA. THUS HV NOT ADDED ANY
THUNDER INTO ZONES ALONG AND NORTH OF THE NY THRUWAY AT THIS TIME.
SKIES EXPECTED TO RMN CLDY ACRS NRN AREAS WITH SOME SUN POSSIBLY
BREAKING OUT BRIEFLY ACRS THE SOUTH. EXPECT AFTN MAXES SIMILAR TO
YDA WITH HIGHS ARND 80 ACRS WRN AND SRN ZONES AND ONLY INTO THE 60S
OVR NE CNTYS.
FNT WL BEGIN LIFTING NORTH SAT NGT AS HIPRES BUILDS INTO THE
CANADIAN MARITIMES AND SRLY WINDS INCRS. EXPECT SLGT/CHC SHOWERS
THRU THE OVRNGT ACRS CWA, INCRSG TO LKLY TWD SUN MRNG ACRS NRN ZONES
AS EJECTING WV FM UPSTREAM CLOSED LOW RIDES ALONG FRONTAL BNDRY AND
INITIATES CONVECTION.
OVRNGT LOWS FOR SUN MRNG WL LKLY RMN ARND NRML VALUES (L/M 60S) FOR
HIGHS THIS TIME OF YR, NOT EVEN CLOSE TO NORMAL LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
330 AM UPDATE...
CWA WL BE IN WM SECTOR ON SUNDAY WITH SCTD CONVECTION EXPECTED OFF
AND ON THROUGHOUT THE DAY AS ANY SUBTLE WVS THAT CAN MV THRU WL
GENERATE CHCS FOR SHRA/TSRA. FOR NOW, HV NOT MADE MANY CHGS DUE TO
UNSETTLED PATTERN AND DIFFICULTY RESOLVING ANY TRIGGERS.
AREA RMNS IN WARM SECTOR ON SUN NGT AND CAN EXPECT JUST CHC SHOWERS
THRU 12Z MON SO HV DROPPED POPS TO JUST 30% AT THIS TIME FOR THE PD.
WARM AND HUMID CONDS WL CONT THRU MON MRNG WITH TEMPS AND TDS IN THE
U50S/L60S.
MOISTURE FM TROPICAL STORM KAREN PROGGED BY GFS TO WORK UP INTO AREA
MON NGT. HWVR, THIS WL ALL DEPEND ON HOW MUCH H5 SYSTEM SLOWS DOWN
AND IF FRONTAL BNDRY CAN HOLD OFF ENUF TO BRING MOISTURE INTO AREA.
AS OF NOW WITH PW VALUES INCRSG TO BTWN 1.5 AND 1.75 INCHES ON MON
NGT EXPECTED 12-HR QPF VALUES FM HPC WL AVG ARND 1 INCH THRU THE END
OF THE SHORT TERM. FROPA LOOKS TO HV SLOWED DOWN ENUF TO OCCUR AT
THE VRY TAIL END OF THE SHORT TERM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
345 AM UPDATE...
MED RNG GRIDS UPDATED WITH 00Z WPC GDNC (BLENDED WITH SOME GFS/MOS
DATA) TO REFLECT A SLOWER MVMNT OF THE UPR LOW...WITH AN EXTENSION OF
CHC POPS INTO MID WEEK AND MORE IN THE WAY OF CLDS DUE TO THIS
SYSTEM. PREV BLO...
2 PM UPDATE...
MAIN INTEREST IN THE LONG TERM FORECAST WILL BE THE POTENTIAL FOR
HEAVY RAIN MONDAY NIGHT. THE MAIN WEATHER PLAYERS WILL BE AN UPPER
LEVEL LOW NOW OVER SE WYOMING...AND ASSOCIATED COLD FRONT OVER THE
CENTRAL PLAINS. AS THESE FEATURES MOVE EAST THE SOUTHERLY FLOW OF
AIR AHEAD OF THEM WILL TRANSPORT MOISTURE...SOME OF IT WILL BE
WHATS LEFT OF TS KAREN...NORTHWARD INTO OUR AREA. WITH HIGH
VARIANCE IN THE MODELS JUST 24 HOURS AGO...THE 12Z NAM AND GFS ARE
FAIRLY SIMILAR IN SHOWING AN AREA OF STEADY RAIN ALONG AND AHEAD
OF THE COLD FRONT MOVING INTO OUR AREA MONDAY EVENING. BOTH THE
GFS AND WPC GUIDANCE SHOW A GENERAL 1" TO 2" RAIN ACROSS THE AREA
MONDAY NIGHT...WITH ISOLATED HIGHER AMOUNTS POSSIBLE. WITH OUR
RECENT STRETCH OF DRY WEATHER AND THE PROGRESSIVE NATURE OF THE
FRONT (RAIN FALLING IN 12 HOURS OR LESS)...WIDESPREAD PROBLEMS ARE
NOT EXPECTED AT THIS EARLY JUNCTURE. IN FACT FOR MOST THIS WILL BE
A WELCOME BENEFICIAL FALL RAIN.
LATER TUESDAY AND BEYOND...THE GFS IS NOW THE SLOWEST WITH THE
UPPER LEVEL LOW MOVING OVER OUR AREA AND KEEPING US
CLOUDY/UNSETTLED FOR ONE MORE DAY. WILL LEAN WITH WPC GUIDANCE
DRYING US OUT BY TUESDAY NIGHT. HIGH PRESSURE CONTROLS THE REST OF
THE PERIOD WITH QUIET WEATHER EXPECTED.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
FNTL BNDRY DRAPED OVER THE TWIN TIERS/NRN PA WITH LIFR/IFR TO THE N
OF THE FNT. PROFILES SUGGEST THESE CONDITIONS TO CONTINUE THRU THE
MID MRNG HRS...WITH ITH/ELM/BGM/SYR/AVP BLO ALT MINS AND BRIEFLY
LIKELY BLO AIRPORT MINS THRU 14Z. COULD SEE SCT -SHRA THIS MRNG
14-16Z AT SYR/RME IF ACTIVITY OVER WRN NY HOLDS TOGETHER. XPCT CIGS TO SLOWLY
LIFT LATE THIS MRNG/AFTN TO MVFR MOST SITES. CHCS FOR SHRA APPEAR
TO BE GREATEST THIS AFTN NEAR THE FNT AND INCLUDED TEMPOS FOR
SHRA AT ITH/ELM/BGM/AVP THIS AFTN. POTNL FOR TSRA ACRS SRN SITES
WHICH MAY BE ADDED WITH LATER FCST UPDATES. TNGT...MVFR XPCTD TO
PREVAIL THRU 06Z...WITH POTNL FOR MVFR/IFR MAINLY AFTER 06Z AS -SHRA
MOV BACK IN. WINDS ON THE LGT SIDE AND RATHER VRBL...MAINLY FROM A
NORTHERLY DIRECTION ACRS CNTRL NY...BECMG ERLY OR SELY TNGT.
OUTLOOK...
SATURDAY NIGHT THROUGH WEDNESDAY...AN UNSETTLED PERIOD...WITH SCATTERED
TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF
RESTRICTIVE CONDS FROM TIME TO TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
922 AM EDT SAT OCT 5 2013
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN OVER THE REGION THROUGH TONIGHT
THEN LIFT NORTH AS A WARM FRONT ON SUNDAY. THIS WILL KEEP OUR
WEATHER UNSETTLED THROUGH THE WEEKEND WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS, PRIMARILY DURING THE DAYLIGHT HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE...LOCAL RADAR SHOWS A CLUSTER OF SHOWERS WITH
EMBEDDED ISOLATED THUNDER MOVING INTO THE FINGER LAKES REGION.
BASED ON CURRENT MOVEMENT AND HRRR OUTPUT THIS CLUSTER WILL MOVE
ACROSS THE FINGER LAKES REGION AND INTO THE NRN CWA THROUGH LATE
MORNING. INCREASED POPS IN THE ABOVE MENTIONED AREAS AND INCLUDED
ISOLATED T EXCEPT FAR NRN CWA WHERE MODEL SOUNDINGS INDICATE NO
INSTABILITY. REST OF FORECAST IN GOOD SHAPE.
620 AM UPDATE...
TEMPS HV STAYED UP IN THE 60S UNDER EXTENSIVE STRATUS AND FOG
DECK. EXPECT PATCHY DENSE FOG WL CONTINUE THRU 14Z ALONG WITH
ISOLD SHOWERS WITH STATIONARY FRONT LURKING ACRS THE AREA. AREA OF
SHOWERS MVG INTO NIAGARA FRONTIER AHD OF S/WV MAY MV INTO WRN
CNTYS TWD 12Z. KEPT SLGT CHC POPS IN ALL NIGHT FOR CNTRL CNTYS AND
EXPECT POPS TO INCRS IN CVRG ACRS TWIN TIERS TWD LATE MRNG. THUS
NO CHGS NEEDED AT THIS TIME OTHER THAN T/TD GRIDS TO COME MORE
INTO LINE WITH REALITY.
PREV DISCUSSION BLO...
330 AM UPDATE...
WMFNT IS CURRENTLY STRETCHED FM SFC LOW NR PIERRE SD ALONG THE I-90
CORRIDOR TO BTWN KBUF AND KERI AND ALONG NY/PA BORDER. DO NOT EXPECT
MUCH IN THE WAY OF MVMNT TDA AS 1028MB HIPRES RMNS LOCKED ACRS ERN
CANADA AND CLOSED LOW JUST CREEPS ALONG, ROUGHLY 100 MILES IN 12
HRS, AS IT WAITS FOR AN UPSTREAM KICKER.
AS FOR TDA`S FCST EXPECT ISOLD/SCTD CONVECTION AS WMFNT RMNS OVR
AREA. ISOLD SHOWERS EXPECTED UNTIL ABOUT NOON TDA AS ANY EMBEDDED
S/WVS MAY KICK SOMETHING OFF WITH FRONTAL BNDRY IN AREA. HWVR AFT
ABOUT 16Z INSTABILITY LOOKS TO NOSE INTO REGION MAINLY ALONG BNDRY
WITH CAPES BTWN 200-400 J/KG AND K-INDICES APPCHG 35. EXPECT
CONVECTION AFT THIS TIME ACRS THE SRN TIER/SUSQ REGION, THEN SOUTH
INTO NEPA AFT 18Z. NRN CNTYS EXPECTED TO BE SOCKED IN WITH LOCLDS
ALL DAY NORTH OF THE BNDRY SIMILAR TO YDA. THUS HV NOT ADDED ANY
THUNDER INTO ZONES ALONG AND NORTH OF THE NY THRUWAY AT THIS TIME.
SKIES EXPECTED TO RMN CLDY ACRS NRN AREAS WITH SOME SUN POSSIBLY
BREAKING OUT BRIEFLY ACRS THE SOUTH. EXPECT AFTN MAXES SIMILAR TO
YDA WITH HIGHS ARND 80 ACRS WRN AND SRN ZONES AND ONLY INTO THE 60S
OVR NE CNTYS.
FNT WL BEGIN LIFTING NORTH SAT NGT AS HIPRES BUILDS INTO THE
CANADIAN MARITIMES AND SRLY WINDS INCRS. EXPECT SLGT/CHC SHOWERS
THRU THE OVRNGT ACRS CWA, INCRSG TO LKLY TWD SUN MRNG ACRS NRN ZONES
AS EJECTING WV FM UPSTREAM CLOSED LOW RIDES ALONG FRONTAL BNDRY AND
INITIATES CONVECTION.
OVRNGT LOWS FOR SUN MRNG WL LKLY RMN ARND NRML VALUES (L/M 60S) FOR
HIGHS THIS TIME OF YR, NOT EVEN CLOSE TO NORMAL LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
330 AM UPDATE...
CWA WL BE IN WM SECTOR ON SUNDAY WITH SCTD CONVECTION EXPECTED OFF
AND ON THROUGHOUT THE DAY AS ANY SUBTLE WVS THAT CAN MV THRU WL
GENERATE CHCS FOR SHRA/TSRA. FOR NOW, HV NOT MADE MANY CHGS DUE TO
UNSETTLED PATTERN AND DIFFICULTY RESOLVING ANY TRIGGERS.
AREA RMNS IN WARM SECTOR ON SUN NGT AND CAN EXPECT JUST CHC SHOWERS
THRU 12Z MON SO HV DROPPED POPS TO JUST 30% AT THIS TIME FOR THE PD.
WARM AND HUMID CONDS WL CONT THRU MON MRNG WITH TEMPS AND TDS IN THE
U50S/L60S.
MOISTURE FM TROPICAL STORM KAREN PROGGED BY GFS TO WORK UP INTO AREA
MON NGT. HWVR, THIS WL ALL DEPEND ON HOW MUCH H5 SYSTEM SLOWS DOWN
AND IF FRONTAL BNDRY CAN HOLD OFF ENUF TO BRING MOISTURE INTO AREA.
AS OF NOW WITH PW VALUES INCRSG TO BTWN 1.5 AND 1.75 INCHES ON MON
NGT EXPECTED 12-HR QPF VALUES FM HPC WL AVG ARND 1 INCH THRU THE END
OF THE SHORT TERM. FROPA LOOKS TO HV SLOWED DOWN ENUF TO OCCUR AT
THE VRY TAIL END OF THE SHORT TERM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
345 AM UPDATE...
MED RNG GRIDS UPDATED WITH 00Z WPC GDNC (BLENDED WITH SOME GFS/MOS
DATA) TO REFLECT A SLOWER MVMNT OF THE UPR LOW...WITH AN EXTENSION OF
CHC POPS INTO MID WEEK AND MORE IN THE WAY OF CLDS DUE TO THIS
SYSTEM. PREV BLO...
2 PM UPDATE...
MAIN INTEREST IN THE LONG TERM FORECAST WILL BE THE POTENTIAL FOR
HEAVY RAIN MONDAY NIGHT. THE MAIN WEATHER PLAYERS WILL BE AN UPPER
LEVEL LOW NOW OVER SE WYOMING...AND ASSOCIATED COLD FRONT OVER THE
CENTRAL PLAINS. AS THESE FEATURES MOVE EAST THE SOUTHERLY FLOW OF
AIR AHEAD OF THEM WILL TRANSPORT MOISTURE...SOME OF IT WILL BE
WHATS LEFT OF TS KAREN...NORTHWARD INTO OUR AREA. WITH HIGH
VARIANCE IN THE MODELS JUST 24 HOURS AGO...THE 12Z NAM AND GFS ARE
FAIRLY SIMILAR IN SHOWING AN AREA OF STEADY RAIN ALONG AND AHEAD
OF THE COLD FRONT MOVING INTO OUR AREA MONDAY EVENING. BOTH THE
GFS AND WPC GUIDANCE SHOW A GENERAL 1" TO 2" RAIN ACROSS THE AREA
MONDAY NIGHT...WITH ISOLATED HIGHER AMOUNTS POSSIBLE. WITH OUR
RECENT STRETCH OF DRY WEATHER AND THE PROGRESSIVE NATURE OF THE
FRONT (RAIN FALLING IN 12 HOURS OR LESS)...WIDESPREAD PROBLEMS ARE
NOT EXPECTED AT THIS EARLY JUNCTURE. IN FACT FOR MOST THIS WILL BE
A WELCOME BENEFICIAL FALL RAIN.
LATER TUESDAY AND BEYOND...THE GFS IS NOW THE SLOWEST WITH THE
UPPER LEVEL LOW MOVING OVER OUR AREA AND KEEPING US
CLOUDY/UNSETTLED FOR ONE MORE DAY. WILL LEAN WITH WPC GUIDANCE
DRYING US OUT BY TUESDAY NIGHT. HIGH PRESSURE CONTROLS THE REST OF
THE PERIOD WITH QUIET WEATHER EXPECTED.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
FNTL BNDRY DRAPED OVER THE TWIN TIERS/NRN PA WITH LIFR/IFR TO THE N
OF THE FNT. PROFILES SUGGEST THESE CONDITIONS TO CONTINUE THRU THE
MID MRNG HRS...WITH ITH/ELM/BGM/SYR/AVP BLO ALT MINS AND BRIEFLY
LIKELY BLO AIRPORT MINS THRU 14Z. COULD SEE SCT -SHRA THIS MRNG
14-16Z AT SYR/RME IF ACTIVITY OVER WRN NY HOLDS TOGETHER. XPCT CIGS TO SLOWLY
LIFT LATE THIS MRNG/AFTN TO MVFR MOST SITES. CHCS FOR SHRA APPEAR
TO BE GREATEST THIS AFTN NEAR THE FNT AND INCLUDED TEMPOS FOR
SHRA AT ITH/ELM/BGM/AVP THIS AFTN. POTNL FOR TSRA ACRS SRN SITES
WHICH MAY BE ADDED WITH LATER FCST UPDATES. TNGT...MVFR XPCTD TO
PREVAIL THRU 06Z...WITH POTNL FOR MVFR/IFR MAINLY AFTER 06Z AS -SHRA
MOV BACK IN. WINDS ON THE LGT SIDE AND RATHER VRBL...MAINLY FROM A
NORTHERLY DIRECTION ACRS CNTRL NY...BECMG ERLY OR SELY TNGT.
OUTLOOK...
SATURDAY NIGHT THROUGH WEDNESDAY...AN UNSETTLED PERIOD...WITH SCATTERED
TO WIDESPREAD SHOWERS ANTICIPATED...ALG WITH THE LIKELIHOOD OF
RESTRICTIVE CONDS FROM TIME TO TIME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1151 PM EDT SUN OCT 6 2013
.SYNOPSIS...
A FEW SHOWERS WILL CONTINUE THIS AFTERNOON AND TONIGHT. A STRONG
COLD FRONT WILL CROSS THE CAROLINAS LATE MONDAY...BRINGING A
PERIOD OF SHOWERS AND THUNDERSTORMS. MOISTURE AND BLUSTERY
CONDITIONS WILL CONTINUE TUESDAY AND WEDNESDAY. A DRYING TREND
SHOULD DEVELOP LATER IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1100 PM SUNDAY...STREAMER TYPE CONVECTION FROM OFF THE ATL
WATERS TO CONTINUE OVERNIGHT. SPEED CONVERGENCE IN THE LOWER
LEVELS AS A RESULT OF THE SE-S ONSHORE FLOW CONTINUES TO FIRE LOW
TOPPED CONVECTION ACROSS THE ILM COASTAL WATERS AND ONSHORE. WITH
THE DAYS INSOLATION OVERWITH...THE ACTIVITY THAT MOVES ONSHORE
WILL FOR THE MOST PART BE UNABLE TO SUSTAIN ITS INTENSITY LET
ALONE ITS INTEGRITY AS IT PROGRESSES FURTHER INLAND. THIS
CURRENTLY IS BEING PLAYED OUT AS ONE LOOPS THE KLTX AND
SURROUNDING RADARS. ALTHO CURRENT LTG REMAINS LACKING...THE
ACTIVITY OVER THE ADJACENT ATL WATERS WILL HAVE INCREASING AND
DEEPER INSTABILITY OVERNIGHT AS ACTIVITY PASSES OVER SSTS THAT
ARE AROUND 80 DEGREES. WOULD NOT BE SURPRISED FOR THUNDER TO
OCCUR...AND POSSIBLY REACH AND PUSH ONSHORE LATER OVERNIGHT. NO
PRONOUNCED UPPER S/W TROF OR VORT TO AFFECT THE FA OVERNITE THAT
WOULD PROVIDE ADDITIONAL FORCING TO FURTHER PROMOTE THUNDER. THIS
IS NOT PROGGED BY THE MODELS TO OCCUR UNTIL DAYTIME MONDAY WHILE
APPROACHING FROM THE WEST. HOWEVER...ENOUGH CAPE MANIFESTS ACROSS
THE FA TOWARD DAYBREAK MONDAY AS EXHIBITED BY THE LATEST HRRR
MODEL RUN...TO AT-LEAST MENTION ISOLATED THUNDER DURING THIS TIME
FRAME. OVERALL...POPS ACROSS THE FA OVERNIGHT WILL RANGE BETWEEN
25 TO 50 PERCENT.
WIDESPREAD 70+ SFC DEWPTS CURRENTLY ACROSS THE FA. DO NOT SEE
MUCH OF A DOWNWARD OR DECREASING TREND OVERNITE WITH SFC DEWPTS.
AS A RESULT...LOOKING AT WIDESPREAD 70 TO 75 DEGREE LOWS FOR
TONIGHT...WHICH IS NEARLY 15 DEGREES HIGHER THAN CLIMO NORMS FOR
THIS TIME OF THE YEAR. MUST BE GLOBAL WARMING AGAIN.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...THE SHORT TERM CONTINUES TO TREND TO A VERY
ACTIVE PERIOD MOSTLY AS A RESULT OF MODEL CONSENSUS ON THE EVENTS
FOR TUESDAY.
THE 1200 UTC GFS AND NAM ARE IN AGREEMENT ON A MID LEVEL LOW CUTTING
OFF IN THE SOUTHEAST TUESDAY WITH BROAD ISENTROPIC LIFT DEVELOPING
BETWEEN STRONG HIGH PRESSURE TO THE NORTH AND THE ASSOCIATED SURFACE
LOW/TROUGH TO THE SOUTH. IT WILL BE A RATHER WET AND RAW DAY AS
GUIDANCE SHOWS HIGH TEMPERATURES REMAINING IN THE 60S WITH WIND
SPEEDS FROM THE EAST/NORTHEAST AT 10-15 MPH. THE LACK OF SATURATION
IN THE 305K LAYER AND MODEST ISENTROPIC LIFT...WINDS ARE ACTUALLY
FAIRLY LIGHT ABOVE THE SURFACE MAY KEEP QPF VALUES MODEST. HOWEVER
SUBSEQUENT SHIFTS MAY WANT TO INCREASE POPS ESPECIALLY LATE IN THE
PERIOD AS THE COLUMN SHOWS BETTER SATURATION IN THIS LAYER.
AS FOR THE EVENTS MONDAY...LITTLE CHANGE WAS WARRANTED WITH THE
FORECAST AS THE MODELS ARE STILL IN AGREEMENT ON THE
FRONT...CURRENTLY LOCATED IN THE TENNESSEE VALLEY MOVING ACROSS
MONDAY EVENING. MAINTAINED THE LIKELY TO CATEGORICAL POPS WITH THE
SAME TEMPORAL TRENDS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...WEDNESDAY NO LONGER LOOKING DRY AS PREVIOUSLY
THOUGHT. A WEAK SOUTHERN BRANCH SHORTWAVE LIFTS OUT OF THE GULF OF
MEXICO EARLY IN THE WEEK AND CROSSES THE CAROLINAS WEDNESDAY. THERE
IS STILL COPIOUS/DEEP MOISTURE IN PLACE AS THE THE MONDAY COLD FRONT
ONLY SEEMS TO REMOVE THE SURFACE MOISTURE. THE UPPER SYSTEM INDUCES
A WAVE ALONG THE BOUNDARY WELL OFFSHORE ON WEDNESDAY BUT ITS
LOCATION IS NOT AGREED UPON BY VARIOUS GUIDANCE. INTERESTINGLY THE
EC DOESN`T REALLY DEVELOP A WAVE BUT STILL HAS QPF AS THE UPPER
SHORTWAVE MOVES ATOP THE WEDGE. WILL INTRODUCE LOW CHC POPS MAINLY
ALONG THE COAST. MOST IF NOT ALL OF THE REMAINDER OF THE PERIOD WILL
BRING DRY WEATHER AS BUILDING UPPER LEVEL RIDGE AND SOUTHWARD
SPRAWLING SURFACE HIGH OCCUPY OUR LONGITUDE. THE GFS CONTINUES TO
SHOW THAT OUR WEDNESDAY SHORTWAVE EVENTUALLY BEARS A LOW OFF THE
DELMARVA COAST THAT RETROGRADES AND MAY BRING SOME WEEKEND POPS. FOR
NOW THIS LOOKS JUST ANOMALOUS ENOUGH TO CAP POPS AT SLIGHT. THE EC
ALSO SHOWS SOME ATLANTIC DEVELOPMENT BUT NOT THE RETROGRADING MOTION.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...CURRENTLY VFR CONDITIONS ARE BEING REPORTED AT ALL TERMS
WITH S-SE WINDS AOB 8 KTS. VFR SHOULD PREVAIL EARLY THIS EVENING
WITH MID-LEVEL CIGS 8-10KFT AND FEW/SCT LOW CLOUDS 1-2KFT. SOME
TEMPO PERIODS OF MVFR/IFR ARE POSSIBLE BEFORE 06Z ALONG THE COAST...
BUT ANY RESTRICTIONS SHOULD BE SHORT-LIVED. FCST SOUNDINGS AND
GUIDANCE CALL FOR MVFR/IFR CIGS TO DEVELOP LATER TONIGHT...WHICH
MAKES SENSE GIVEN THE MOIST LOW-LEVEL ENVIRONMENT. EXPECT MAINLY
MVFR CIGS ALONG THE COAST AND MVFR/IFR CIGS INLAND AFTER 06Z THROUGH
SUNRISE. THE LOW-LEVEL WINDS WILL BE TOO STRONG TO SUPPORT ANY FOG.
AN APPROACHING COLD FRONT WILL BRING SHRA/ISO TSRA TO OUR FORECAST
AREA ON MONDAY. FCST SOUNDINGS SHOW PWAT VALUES SURGING TO NEAR 2
INCHES DURING THE DAY. VFR/MVFR CONDITIONS WILL LIKELY PREVAIL FROM
LATE MORNING THROUGH THE AFTN HOURS...WITH TEMPO PERIODS OF IFR
VSBYS IN HEAVIER SHOWERS. EXPECT SOUTH WINDS AROUND 10 KTS ON
MONDAY...WITH GUSTS OF 15-20 KTS POSSIBLE ALONG THE COAST. BY 00Z
TUESDAY...THE COLD FRONT SHOULD BE NEARING KLBT/KFLO.
EXTENDED OUTLOOK...SCATTERED SHOWERS WITH MVFR CIGS ON TUESDAY AS
THE FRONT LINGERS OFFSHORE. MVFR/IFR CIGS POSSIBLE ON WEDNESDAY
MORNING...BECOMING VFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 PM SUNDAY...LATEST PIER AND BUOY OBS ACROSS THE AREA
WATERS INDICATE WINDS ARE RUNNING CLOSE TO THE CURRENT FORECAST
TREND. WILL ONLY MAKE SLIGHT ADJUSTMENTS TO WIND DIRECTIONS...WITH
SE-S BEING ADVERTISED INSTEAD OF INDICATING A SSE WIND DIRECTION.
LATEST HRRR SFC WIND OUTPUT ACROSS THE ILM WATERS CONTINUES WITH
10-15 KT...INCREASING TO 15-20 KT BY DAYBREAK. THIS ONSHORE FLOW
WILL BUILD SIGNIFICANT SEAS RATHER QUICKLY OVERNIGHT...WITH THE
MAJORITY OF THE ILM COASTAL WATERS AT 3 TO 5 FT BY DAYBREAK
MONDAY. BUILDING WIND DRIVEN WAVES AT 4 TO 6 SECOND PERIODS WILL
DOMINATE THE WAVE SPECTRUM OVERNIGHT. THE SMALL ESE 9 TO 11 SECOND
PERIOD GROUND SWELL WILL PROVIDE NO AID FOR INCREASING THE SIG.
SEAS.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...THE MARINE COMMUNITY WILL SEE RATHER CHANGEABLE
CONDITIONS THROUGH THE PERIOD. EXPECT A SOUTHEAST FLOW OF 15-20
KNOTS INITIALLY. THIS FLOW WILL WEAKEN AND VEER TO THE SOUTH THEN
SOUTHWEST BY THE END OF THE DAY MONDAY. A FRONT WILL MOVE ACROSS THE
WATERS AROUND 0600 UTC TUESDAY WITH A NORTH TO NORTHEASTERLY FLOW
DEVELOPING BY 1200 TUESDAY. SPEEDS WILL INCREASE AS WELL TO 15-20
KNOTS BY THIS TIME. THIS PATTERN WILL REMAIN IN PLACE THROUGH THE
END OF THE PERIOD. SIGNIFICANT SEAS ARE 3-5 FEET EARLY IN THE PERIOD
WITH A DECREASE MONDAY EVENING. SEAS WILL INCREASE ONCE AGAIN
TUESDAY ESPECIALLY LATER IN THE DAY TO POSSIBLY SMALL CRAFT
CRITERIA.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...LONG DURATION OF NORTHERLY FLOW EXPECTED.
HIGH PRESSURE WEDGING IN EAST OF THE APPALACHIANS TO PRODUCE A
MODERATE GRADIENT ACROSS THE WATERS. A WAVE OF LOW PRESSURE SHOULD
DEVELOP SOMEWHERE ALONG COLD FRONT STALLED WELL OFFSHORE BUT ITS
LOCATION IS UNCERTAIN AT THIS POINT. THIS IS EXPECTED TO MODULATE
THE STRENGTH OF THE GRADIENT AND HAVE AN IMPACT ON THE STRENGTH OF
THE GRADIENT PINCH AND WHETHER OR NOT WELL NEED ANY HEADLINES OR
EVEN BORDERLINE AND SHORT-LIVED ADVISORY OUT ALONG FRYING PAN
SHOALS. WHEREVER THIS LOW DEVELOPS...IT WILL PULL AWAY TO THE
NORTH AND EAST THURSDAY INTO FRIDAY AND THE SURFACE HIGH WILL
REMAIN ENTRENCHED ACROSS THE EASTERN U.S.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
905 PM EDT SUN OCT 6 2013
.SYNOPSIS...
A FEW SHOWERS WILL CONTINUE THIS AFTERNOON AND TONIGHT. A STRONG
COLD FRONT WILL CROSS THE CAROLINAS LATE MONDAY...BRINGING A
PERIOD OF SHOWERS AND THUNDERSTORMS. MOISTURE AND BLUSTERY
CONDITIONS WILL CONTINUE TUESDAY AND WEDNESDAY. A DRYING TREND
SHOULD DEVELOP LATER IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 745 PM SUNDAY...SPEED CONVERGENCE IN THE LOWER LEVELS AS
A RESULT OF THE SE-S ONSHORE FLOW CONTINUES TO FIRE LOW TOPPED
CONVECTION ACROSS THE ILM COASTAL WATERS AND ONSHORE. WITH THE
DAYS HEATING IE. FUEL OVER-WITH...THE ACTIVITY THAT MOVES ONSHORE
WILL FOR THE MOST PART BE UNABLE TO SUSTAIN ITS INTENSITY LET
ALONE CONTINUING TO OCCUR AS IT PROGRESSES FURTHER INLAND BY 1
COUNTY. THIS CURRENTLY IS BEING PLAYED OUT AS ONE LOOPS THE KLTX
AND SURROUNDING RADAR DISPLAYS. ALTHO CURRENT LTG CONTINUES TO
LACK...THE ACTIVITY OVER THE ADJACENT ATL WATERS WILL HAVE
INCREASING AND DEEPER INSTABILITY OVERNIGHT ESPECIALLY WHERE SSTS
ARE AROUND 80 DEGREES. WOULD NOT BE SURPRISED FOR THUNDER TO
OCCUR...AND POSSIBLY REACH AND PUSH ONSHORE LATE TONIGHT. NO
PRONOUNCED S/W TROF OR VORT IN THE MID-LEVELS TO AFFECT THE FA
OVERNITE THAT WOULD PROVIDE ADDITIONAL FORCING TO FURTHER PROMOTE
THUNDER. THIS IS NOT PROGGED TO OCCUR UNTIL DAYTIME MONDAY...THE
SHORT TERM PERIOD. HOWEVER...ENOUGH CAPE...VIA LATEST HRRR MODEL
RUNS...TO AT-LEAST MENTION ISOLATED THUNDER DURING THE PRE-DAWN MON
HRS. OVERALL...POPS ACROSS THE FA OVERNIGHT WILL RANGE BETWEEN 20
TO 50 PERCENT. WIDESPREAD 70+ SFC DEWPTS CURRENTLY ACROSS THE FA.
DO NOT SEE MUCH OF A DOWNWARD OR DECREASE TREND TO OVERNITE SFC
DEWPTS. AS A RESULT...HAVE TWEAKED TONIGHTS MINS UPWARDS ACROSS
THE FA... WITH SOME LOCALES UP BY NEARLY A CATEGORY. THIS WILL
RESULT IN TONIGHTS MIN FORECAST AT NEARLY 15 DEGREES HIGHER THAN
THE CLIMO NORMS.
PREVIOUS DISCUSSION...............................................
AS OF 3 PM SUNDAY...LOW-TOPPED SEMI-TROPICAL SHOWERS WILL CONTINUE
TO MOVE ONSHORE AND DEEPER INTO THE EASTERN CAROLINA INTERIOR INTO
THE LATE AFTERNOON AND EARLY EVENING...AS MOISTURE CONVERGENCE IN
THE LOW-LEVELS CONTINUES TO SPREAD TO THE NW. WITH DIURNAL COOLING
INTO THE OVERNIGHT HOURS...BUOYANCY WILL INCREASE OVER THE MILD
OCEAN WATERS...PROLONGING THE PROSPECT OF PASSING SHOWERS TONIGHT.
KLTX VAD WIND PROFILE CONTINUES TO SHOW A DEEP SOUTHERLY ONSHORE
WIND FLOW SUPPLYING A RICH DOSE OF COLUMN MOISTURE THROUGH 600 MB.
BECAUSE THE CONVERGENCE INLAND WILL ENDURE INTO EVENING...SUSPECT
WE WILL SEE ISOLATED SHOWERS EXTENDING INTO THE NIGHT HOURS ALSO.
WIND SPEEDS IN THE 0-6KM LAYER WILL INCREASE OVERNIGHT AS A COLD
FRONT APPROACHES FROM THE WEST...BUT MOISTURE DEPTH AND OVERALL
MOISTURE PROFILES DO NOT CHANGE A GREAT DEAL...SO THE PLAN IS TO
MAINTAIN ISOLATED TO SCATTERED CONVECTION OVERNIGHT. STORM MOTION
WILL AS A CONSEQUENCE INCREASE...REMAINING A TRACK FROM SOUTH TO
NORTH. THE COASTAL ZONES SHOULD BECOME SLIGHTLY MORE FAVORED LATE
TONIGHT AS BUOYANCY OVER THE WATERS GOES INTO A DIURNAL MAXIMUM.
MILD MINIMUMS TEMPS INTO EARLY MONDAY IS EXPECTED IN THE BLUSTERY
ONSHORE FLOW...AND WILL BE THE MILDEST AND MOST-HUMID EARLY MORNING
WE HAVE SEEN IN A WHILE. LOW 70S ALONG THE COAST AND UPPER 60S TO
AROUND 70 OVER THE INTERIOR OF OUR FORECAST REGION IS EXPECTED AT
DAYBREAK ON MONDAY.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...THE SHORT TERM CONTINUES TO TREND TO A VERY
ACTIVE PERIOD MOSTLY AS A RESULT OF MODEL CONSENSUS ON THE EVENTS
FOR TUESDAY.
THE 1200 UTC GFS AND NAM ARE IN AGREEMENT ON A MID LEVEL LOW CUTTING
OFF IN THE SOUTHEAST TUESDAY WITH BROAD ISENTROPIC LIFT DEVELOPING
BETWEEN STRONG HIGH PRESSURE TO THE NORTH AND THE ASSOCIATED SURFACE
LOW/TROUGH TO THE SOUTH. IT WILL BE A RATHER WET AND RAW DAY AS
GUIDANCE SHOWS HIGH TEMPERATURES REMAINING IN THE 60S WITH WIND
SPEEDS FROM THE EAST/NORTHEAST AT 10-15 MPH. THE LACK OF SATURATION
IN THE 305K LAYER AND MODEST ISENTROPIC LIFT...WINDS ARE ACTUALLY
FAIRLY LIGHT ABOVE THE SURFACE MAY KEEP QPF VALUES MODEST. HOWEVER
SUBSEQUENT SHIFTS MAY WANT TO INCREASE POPS ESPECIALLY LATE IN THE
PERIOD AS THE COLUMN SHOWS BETTER SATURATION IN THIS LAYER.
AS FOR THE EVENTS MONDAY...LITTLE CHANGE WAS WARRANTED WITH THE
FORECAST AS THE MODELS ARE STILL IN AGREEMENT ON THE
FRONT...CURRENTLY LOCATED IN THE TENNESSEE VALLEY MOVING ACROSS
MONDAY EVENING. MAINTAINED THE LIKELY TO CATEGORICAL POPS WITH THE
SAME TEMPORAL TRENDS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...WEDNESDAY NO LONGER LOOKING DRY AS PREVIOUSLY
THOUGHT. A WEAK SOUTHERN BRANCH SHORTWAVE LIFTS OUT OF THE GULF OF
MEXICO EARLY IN THE WEEK AND CROSSES THE CAROLINAS WEDNESDAY. THERE
IS STILL COPIOUS/DEEP MOISTURE IN PLACE AS THE THE MONDAY COLD FRONT
ONLY SEEMS TO REMOVE THE SURFACE MOISTURE. THE UPPER SYSTEM INDUCES
A WAVE ALONG THE BOUNDARY WELL OFFSHORE ON WEDNESDAY BUT ITS
LOCATION IS NOT AGREED UPON BY VARIOUS GUIDANCE. INTERESTINGLY THE
EC DOESN`T REALLY DEVELOP A WAVE BUT STILL HAS QPF AS THE UPPER
SHORTWAVE MOVES ATOP THE WEDGE. WILL INTRODUCE LOW CHC POPS MAINLY
ALONG THE COAST. MOST IF NOT ALL OF THE REMAINDER OF THE PERIOD WILL
BRING DRY WEATHER AS BUILDING UPPER LEVEL RIDGE AND SOUTHWARD
SPRAWLING SURFACE HIGH OCCUPY OUR LONGITUDE. THE GFS CONTINUES TO
SHOW THAT OUR WEDNESDAY SHORTWAVE EVENTUALLY BEARS A LOW OFF THE
DELMARVA COAST THAT RETROGRADES AND MAY BRING SOME WEEKEND POPS. FOR
NOW THIS LOOKS JUST ANOMALOUS ENOUGH TO CAP POPS AT SLIGHT. THE EC
ALSO SHOWS SOME ATLANTIC DEVELOPMENT BUT NOT THE RETROGRADING MOTION.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...CURRENTLY VFR CONDITIONS ARE BEING REPORTED AT ALL TERMS
WITH S-SE WINDS AOB 8 KTS. VFR SHOULD PREVAIL EARLY THIS EVENING
WITH MID-LEVEL CIGS 8-10KFT AND FEW/SCT LOW CLOUDS 1-2KFT. SOME
TEMPO PERIODS OF MVFR/IFR ARE POSSIBLE BEFORE 06Z ALONG THE COAST...
BUT ANY RESTRICTIONS SHOULD BE SHORT-LIVED. FCST SOUNDINGS AND
GUIDANCE CALL FOR MVFR/IFR CIGS TO DEVELOP LATER TONIGHT...WHICH
MAKES SENSE GIVEN THE MOIST LOW-LEVEL ENVIRONMENT. EXPECT MAINLY
MVFR CIGS ALONG THE COAST AND MVFR/IFR CIGS INLAND AFTER 06Z THROUGH
SUNRISE. THE LOW-LEVEL WINDS WILL BE TOO STRONG TO SUPPORT ANY FOG.
AN APPROACHING COLD FRONT WILL BRING SHRA/ISO TSRA TO OUR FORECAST
AREA ON MONDAY. FCST SOUNDINGS SHOW PWAT VALUES SURGING TO NEAR 2
INCHES DURING THE DAY. VFR/MVFR CONDITIONS WILL LIKELY PREVAIL FROM
LATE MORNING THROUGH THE AFTN HOURS...WITH TEMPO PERIODS OF IFR
VSBYS IN HEAVIER SHOWERS. EXPECT SOUTH WINDS AROUND 10 KTS ON
MONDAY...WITH GUSTS OF 15-20 KTS POSSIBLE ALONG THE COAST. BY 00Z
TUESDAY...THE COLD FRONT SHOULD BE NEARING KLBT/KFLO.
EXTENDED OUTLOOK...SCATTERED SHOWERS WITH MVFR CIGS ON TUESDAY AS
THE FRONT LINGERS OFFSHORE. MVFR/IFR CIGS POSSIBLE ON WEDNESDAY
MORNING...BECOMING VFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 745 PM SUNDAY...LATEST PIER AND BUOY OBS ACROSS THE AREA
WATERS INDICATE WINDS ARE RUNNING JUST SLIGHTLY BELOW THE CURRENT
FORECAST TREND. HAVE THEREFORE ADJUSTED THE 1ST SEVERAL HRS OF THE
WIND FORECAST TO ACCOUNT FOR THESE CURRENT CONDITIONS...AND THEN
APPLIED THE LATEST HRRR SFC WIND OUTPUT ACROSS THE ILM WATERS FOR
THE REMAINDER OF THE NIGHT. THIS WILL RESULT IN A PROLONGED SE
WIND BEFORE BECOMING DUE S BY DAYBREAK MONDAY...WHICH REMAINS
QUITE CLOSE TO THE CURRENT CWF. THIS ONSHORE FLOW WILL BUILD
SIGNIFICANT SEAS OVERNIGHT...WITH THE MAJORITY OF THE ILM COASTAL
WATERS AT 3 TO 5 FT BY DAYBREAK MONDAY. BUILDING WIND DRIVEN
WAVES AT 4 TO 6 SECOND PERIODS WILL DEFINITELY DOMINATE THE WAVE
SPECTRUM FOR SIGNIFICANT SEAS TONIGHT. THE SMALL ESE 9 TO 11
SECOND PERIOD GROUND SWELL OF THE PREVIOUS DAYS IS BASICALLY NON-
EXISTENT AND WILL PROVIDE NO AID FOR INCREASING SIG. SEAS
OVERNIGHT. AS MENTIONED B4...DOMINANT PERIODS WILL RUN 5 TO 6
SECONDS.
PREVIOUS DISCUSSION..............................................
AS OF 3 PM SUNDAY...SEA CONDITIONS TO GET A LITTLE BUMPY TONIGHT
AS ONSHORE WINDS INCREASE IN ADVANCE OF AN APPROACHING COLD FRONT
BUT NO ADVISORIES HOWEVER ARE EXPECTED THROUGH DAYBREAK MONDAY.
SSE WINDS AROUND 15 KT WILL INCREASE TO 15-20 KT OVERNIGHT...WITH
SEA HEIGHTS RESPONDING AND BUILDING TO 4 FEET...POSSIBLY NEARING 5
FT ACROSS OUR OUTER WATERS AND FRYING PAN SHOALS EARLY ON MONDAY.
THEREFOR AN EXERCISE CAUTION STATEMENT IS PLANNED BEGINNING 6AM
MONDAY. SHOWERS MOVING SOUTH TO NORTH CAN BE EXPECTED THROUGH
TONIGHT OVER THE 0-20 NM WATERS...AND A FEW TSTMS WILL BE POSSIBLE
ALSO. SEAS WILL FEATURE GROWING SE WAVES OVERNIGHT WITH DOMINANT
PERIODS RUNNING NEAR 6 SEC.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...THE MARINE COMMUNITY WILL SEE RATHER CHANGEABLE
CONDITIONS THROUGH THE PERIOD. EXPECT A SOUTHEAST FLOW OF 15-20
KNOTS INITIALLY. THIS FLOW WILL WEAKEN AND VEER TO THE SOUTH THEN
SOUTHWEST BY THE END OF THE DAY MONDAY. A FRONT WILL MOVE ACROSS THE
WATERS AROUND 0600 UTC TUESDAY WITH A NORTH TO NORTHEASTERLY FLOW
DEVELOPING BY 1200 TUESDAY. SPEEDS WILL INCREASE AS WELL TO 15-20
KNOTS BY THIS TIME. THIS PATTERN WILL REMAIN IN PLACE THROUGH THE
END OF THE PERIOD. SIGNIFICANT SEAS ARE 3-5 FEET EARLY IN THE PERIOD
WITH A DECREASE MONDAY EVENING. SEAS WILL INCREASE ONCE AGAIN
TUESDAY ESPECIALLY LATER IN THE DAY TO POSSIBLY SMALL CRAFT
CRITERIA.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...LONG DURATION OF NORTHERLY FLOW EXPECTED.
HIGH PRESSURE WEDGING IN EAST OF THE APPALACHIANS TO PRODUCE A
MODERATE GRADIENT ACROSS THE WATERS. A WAVE OF LOW PRESSURE SHOULD
DEVELOP SOMEWHERE ALONG COLD FRONT STALLED WELL OFFSHORE BUT ITS
LOCATION IS UNCERTAIN AT THIS POINT. THIS IS EXPECTED TO MODULATE
THE STRENGTH OF THE GRADIENT AND HAVE AN IMPACT ON THE STRENGTH OF
THE GRADIENT PINCH AND WHETHER OR NOT WELL NEED ANY HEADLINES OR
EVEN BORDERLINE AND SHORT-LIVED ADVISORY OUT ALONG FRYING PAN
SHOALS. WHEREVER THIS LOW DEVELOPS...IT WILL PULL AWAY TO THE
NORTH AND EAST THURSDAY INTO FRIDAY AND THE SURFACE HIGH WILL
REMAIN ENTRENCHED ACROSS THE EASTERN U.S.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH/MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
155 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 /TODAY AND TONIGHT/...
AS OF 1000 AM SATURDAY...
SURFACE RIDGE REMAINS IN PLACE OVER CENTRAL NORTH CAROLINA...AND
THE MORNING UPPER-AIR ANALYSIS SHOWED THE RIDGE AXIS ALOFT JUST TO
OUR WEST. MORNING AMDAR SOUNDINGS AS WELL AS THE SOUNDING FROM KGSO
NOTED WARMING ALOFT AROUND 600MB OVER THE LAST 24 HOURS...
REPRESENTING STRONG CAPPING. THE LATEST RAP SHOWS THE RIDGE ALOFT
BUILDING EAST OVERHEAD DURING THE AFTERNOON...WITH GOOD SUBSIDENCE
AND LITTLE OR NO MIXED-LAYER CAPE IN THE LOWEST KM. MORNING
SOUNDINGS AND THE KRAX VAD WIND PROFILE NOTED A FAIRLY DEEP...BUT
LIGHT...NORTHERLY COMPONENT TO THE WIND WHICH SHOULD VEER DURING THE
DAY BASED ON THE LATEST RAP AND MOS GUIDANCE. MAIN CHANGES...ALL
MINOR...TO THE FORECAST FOR THE AFTERNOON WERE TO MODIFY THE
DIRECTION OF THE LIGHT WIND INTO THE MID-AFTERNOON HOURS...AND NOTE
JUST A FEW MORE CLOUDS WITH SOME MOSTLY THIN CIRRUS WORKING ITS WAY
EAST OF THE RIDGE AXIS ALOFT. 1000-850MB THICKNESSES FROM THE KGSO
12Z SOUNDING COMBINED WITH THE FORECAST MAXIMUM VALUE OF THAT
PARAMETER THIS AFTERNOON GIVES MAXES IN LINE WITH THE FORECAST.
LOWS TONIGHT WILL BE SIMILAR TO THIS MORNING...IN THE LOWER/MID
60S...COOLEST IN RURAL AND LOW-LYING AREAS. EXPECT AREAS OF FOG
AGAIN TONIGHT UNDER A MAINLY CLEAR SKY...LIGHT WIND...AND SURFACE
DEW POINTS LATE AT NIGHT 60 TO 65.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 345 AM SATURDAY...
AN IMPRESSIVE UPPER LEVEL LOW CENTERED OVER THE UPPER MIDWEST THIS
MORNING WILL TRACK INTO THE CENTRAL MS RIVER VALLEY SUN INTO SUN
NIGHT...WHILE ADDITIONAL SHORTWAVE ENERGY (OVER THE 4-CORNERS REGION
THIS MORNING) DIGS SOUTHEAST THROUGH THE LOWER MIDWEST INTO THE
LOWER MS RIVER VALLEY ALONG THE SOUTHERN PERIPHERY OF THE UPPER LOW.
ADDITIONALLY...TROPICAL CYCLONE KAREN IS EXPECTED TO TRACK SLOWLY
NORTH TOWARD THE GULF COAST ON SUN...MOVING ASHORE SOMEWHERE IN THE
DEEP SOUTH SUN NIGHT. IN THE LOWER LEVELS...A COLD FRONT ASSOC/W AN
OCCLUDED SFC LOW ATTENDANT THE UPPER LEVEL LOW WILL TRACK EAST INTO
THE TN/OH VALLEY ON SUN...APPROACHING THE SOUTHERN APPALACHIANS SUN
NIGHT.
PER THE 00Z GUIDANCE...SOUTHERLY RETURN FLOW AND LOW-LEVEL WARM
ADVECTION WILL NOT SIGNIFICANTLY STRENGTHEN UNTIL SUN NIGHT...AND
THE AIRMASS ON SUNDAY IS EXPECTED TO BE VERY SIMILAR TO TODAY WITH A
PRONOUNCED MID-LEVEL CAP AND MEAGER DIURNAL DESTABILIZATION (AT
BEST). FORCING FOR ASCENT WILL LARGELY BE ABSENT OVER CENTRAL
NC...CONFINED TO THE SEABREEZE OVER THE COASTAL CAROLINAS AND SMALL
AMPLITUDE DISTURBANCES IN STRENGTHENING SW FLOW ALOFT OVER FAR
WESTERN PORTIONS OF THE STATE DURING THE AFT/EVE. AS A RESULT...WILL
CONTINUE TO INDICATE A DRY FCST ON SUN. A RAPID INCREASE IN
LOW-LEVEL MOISTURE ASSOC/W STRENGTHENING SOUTHERLY FLOW WILL OCCUR
SUN NIGHT AND MON MORNING...WITH ASCENT INCREASING IN THE FORM OF
LOW-LEVEL WARM ADVECTION AND DPVA ASSOC/W SMALL AMPLITUDE
DISTURBANCES IN SW FLOW ALOFT. ALL OF THE 00Z GUIDANCE INDICATES
MEASURABLE PRECIP IN THE WESTERN PIEDMONT BY 12Z MON...AND THIS
SEEMS CONSISTENT WITH THE AFOREMENTIONED DISCUSSION. WILL INDICATE
PRECIP CHANCES INCREASING FROM THE WEST AFTER MIDNIGHT...RANGING
FROM 60-80% IN THE FAR WESTERN PIEDMONT TO ~20% ALONG THE I-95
CORRIDOR. EAST OF I-95...FORCING FOR ASCENT WILL BE MUCH WEAKER AND
PRECIP CHANCES WILL LARGELY BE TIED TO SHOWER ACTIVITY MOVING INLAND
FROM THE ATLANTIC IN ASSOC/W ONSHORE FLOW. AS A RESULT...WILL
INDICATE A DRY FCST IN THE FAR NE COASTAL PLAIN WITH A SLIGHT CHANCE
SOUTH OF HWY 64 IN THE SE COASTAL PLAIN.
THICKNESSES WILL BE SLIGHTLY LOWER (PERHAPS 5-10M) THAN TODAY.
THIS...ALONG WITH INCREASING CLOUD COVER DURING THE AFTERNOON SHOULD
RESULT IN HIGHS A FEW DEGREES COOLER THAN TODAY IN THE MID 80S
(84-88F)...COOLEST IN THE WESTERN PIEDMONT. LOWS SUN NIGHT WILL BE
TEMPERED BY CLOUD COVER AND A LIGHT SOUTHERLY BREEZE...IN THE UPPER
60S TO NEAR 70F IN THE SOUTH. -VINCENT
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
THE LATEST INFORMATION FROM THE NHC CONCERNING "KAREN" CONTINUES TO
DOWNGRADE THE TROPICAL SYSTEM. IT HAS BEEN DESCRIBED AS ALREADY
BEING `DECAPITATED" BY ONE FORECASTER - DUE TO STRONGER WINDS ALOFT.
THEREFORE... THE CONFIDENCE OF WHETHER ANY REMNANTS OF `KAREN" WILL
BE LEFT TO BRING INDIRECT IMPACTS (RAIN, SEVERE THREAT) FOR CENTRAL
NC BY EARLY NEXT WEEK HAS LOWERED.
ON A MORE CONFIDENT NOTE... A MID/UPPER LEVEL TROUGH IS FORECAST TO
BE APPROACHING THE APPALACHIANS MONDAY... THEN SWING ACROSS OUR
REGION TUE AND TUE NIGHT. THE MAIN UPPER DYNAMICS ARE FORECAST TO
PUSH FROM THE MIDWEST TO THE GREAT LAKES. HOWEVER... MOISTURE IS
EXPECTED TO SURGE NORTHWARD ALONG THE EASTERN SEABOARD BRINGING
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE COLD FRONT.
IF THE REMNANT LOW PRESSURE OF `KAREN` TRACKS NE INTO NC AS SOME OF
THE MODELS STILL SUGGEST... THERE CAN STILL BE ENHANCED RAINFALL FOR
12-24 HOURS. OTHERWISE... THIS WOULD BE A TYPICAL RAINFALL EVENT
ASSOCIATED WITH A MID-LATITUDE TROUGH EARLY NEXT WEEK.
ONCE THE TROUGH PASSES... CLEARING AND COOLER CONDITIONS ARE
EXPECTED MID THROUGH LATE WEEK. LOWS 50-55. HIGHS 70-75.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 155 PM SATURDAY...
THE 18Z VALID TAF FORECAST WILL BASICALLY BE PERSISTENCE...WITH
SOME AFTERNOON CU DIMINISHING LEAVING A FEW CIRRUS STREAMING ATOP
THE RIDGE AXIS. LIGHT WINDS...MOSTLY LIGHT SOUTH...WITH DEW POINTS
IN THE LOWER TO MID 60S LATE TONIGHT SHOULD RESULT IN AREAS OF FOG
ONCE AGAIN. THE HIGHEST PROBABILITIES OF FOG CONTINUE TO BE TOWARD
KFAY AND KRWI...LESSER TOWARD THE NORTHWEST. THE TAFS NOTE LOCAL
MVFR VISIBILITY TOWARD KGSO AND KINT...LOCAL IFR VISIBILITY AT
KRDU...AND RELATIVELY LOWER VISIBILITIES AT KFAY AND KRWI LATE
TONIGHT INTO EARLY SUNDAY. WITH MIXING SUNDAY MORNING...A MORE
NOTICEABLE SOUTHERLY WIND SHOULD DEVELOP WITH SURFACE SPEEDS
AVERAGING JUST UNDER 10KT BY THE END OF THE 18Z VALID TAF PERIOD.
BEYOND THE 18Z VALID TAF PERIOD...VFR CONDITIONS PERSIST UNTIL JUST
AFTER MIDNIGHT SUNDAY NIGHT INTO MONDAY MORNING. MOISTURE STREAMING
NORTH INTO THE CAROLINAS FROM THE GULF AHEAD OF A COLD FRONT LIKELY
RESULTS IN CONDITIONS BECOMING SUB-VFR WITH AT LEAST NUMEROUS
SHOWERS DEVELOPING. SOUTH WINDS SUNDAY NIGHT INCREASE ALOFT TO 30KT
BY 2000FT AS THE SURFACE GRADIENT INCREASES AHEAD OF THE FRONT. BY
TUESDAY...AVIATION CONDITIONS ARE EXPECTED TO IMPROVE TO
PREDOMINANTLY VFR IN NORTHEAST FLOW BEHIND THE FRONT. THESE
CONDITIONS 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...DJF/VINCENT
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1000 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL MOVE SLOWLY EAST OFFSHORE THE
CAROLINA COAST TONIGHT AND SUNDAY. A COLD FRONT WILL APPROACH THE
MOUNTAINS FROM THE WEST SUNDAY NIGHT...THEN TRACK EASTWARD THROUGH
THE CAROLINAS ON MONDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1000 AM SATURDAY...
SURFACE RIDGE REMAINS IN PLACE OVER CENTRAL NORTH CAROLINA...AND
THE MORNING UPPER-AIR ANALYSIS SHOWED THE RIDGE AXIS ALOFT JUST TO
OUR WEST. MORNING AMDAR SOUNDINGS AS WELL AS THE SOUNDING FROM KGSO
NOTED WARMING ALOFT AROUND 600MB OVER THE LAST 24 HOURS...
REPRESENTING STRONG CAPPING. THE LATEST RAP SHOWS THE RIDGE ALOFT
BUILDING EAST OVERHEAD DURING THE AFTERNOON...WITH GOOD SUBSIDENCE
AND LITTLE OR NO MIXED-LAYER CAPE IN THE LOWEST KM. MORNING
SOUNDINGS AND THE KRAX VAD WIND PROFILE NOTED A FAIRLY DEEP...BUT
LIGHT...NORTHERLY COMPONENT TO THE WIND WHICH SHOULD VEER DURING THE
DAY BASED ON THE LATEST RAP AND MOS GUIDANCE. MAIN CHANGES...ALL
MINOR...TO THE FORECAST FOR THE AFTERNOON WERE TO MODIFY THE
DIRECTION OF THE LIGHT WIND INTO THE MID-AFTERNOON HOURS...AND NOTE
JUST A FEW MORE CLOUDS WITH SOME MOSTLY THIN CIRRUS WORKING ITS WAY
EAST OF THE RIDGE AXIS ALOFT. 1000-850MB THICKNESSES FROM THE KGSO
12Z SOUNDING COMBINED WITH THE FORECAST MAXIMUM VALUE OF THAT
PARAMETER THIS AFTERNOON GIVES MAXES IN LINE WITH THE FORECAST.
LOWS TONIGHT WILL BE SIMILAR TO THIS MORNING...IN THE LOWER/MID
60S...COOLEST IN RURAL AND LOW-LYING AREAS. EXPECT AREAS OF FOG
AGAIN TONIGHT UNDER A MAINLY CLEAR SKY...LIGHT WIND...AND SURFACE
DEW POINTS LATE AT NIGHT 60 TO 65.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 345 AM SATURDAY...
AN IMPRESSIVE UPPER LEVEL LOW CENTERED OVER THE UPPER MIDWEST THIS
MORNING WILL TRACK INTO THE CENTRAL MS RIVER VALLEY SUN INTO SUN
NIGHT...WHILE ADDITIONAL SHORTWAVE ENERGY (OVER THE 4-CORNERS REGION
THIS MORNING) DIGS SOUTHEAST THROUGH THE LOWER MIDWEST INTO THE
LOWER MS RIVER VALLEY ALONG THE SOUTHERN PERIPHERY OF THE UPPER LOW.
ADDITIONALLY...TROPICAL CYCLONE KAREN IS EXPECTED TO TRACK SLOWLY
NORTH TOWARD THE GULF COAST ON SUN...MOVING ASHORE SOMEWHERE IN THE
DEEP SOUTH SUN NIGHT. IN THE LOWER LEVELS...A COLD FRONT ASSOC/W AN
OCCLUDED SFC LOW ATTENDANT THE UPPER LEVEL LOW WILL TRACK EAST INTO
THE TN/OH VALLEY ON SUN...APPROACHING THE SOUTHERN APPALACHIANS SUN
NIGHT.
PER THE 00Z GUIDANCE...SOUTHERLY RETURN FLOW AND LOW-LEVEL WARM
ADVECTION WILL NOT SIGNIFICANTLY STRENGTHEN UNTIL SUN NIGHT...AND
THE AIRMASS ON SUNDAY IS EXPECTED TO BE VERY SIMILAR TO TODAY WITH A
PRONOUNCED MID-LEVEL CAP AND MEAGER DIURNAL DESTABILIZATION (AT
BEST). FORCING FOR ASCENT WILL LARGELY BE ABSENT OVER CENTRAL
NC...CONFINED TO THE SEABREEZE OVER THE COASTAL CAROLINAS AND SMALL
AMPLITUDE DISTURBANCES IN STRENGTHENING SW FLOW ALOFT OVER FAR
WESTERN PORTIONS OF THE STATE DURING THE AFT/EVE. AS A RESULT...WILL
CONTINUE TO INDICATE A DRY FCST ON SUN. A RAPID INCREASE IN
LOW-LEVEL MOISTURE ASSOC/W STRENGTHENING SOUTHERLY FLOW WILL OCCUR
SUN NIGHT AND MON MORNING...WITH ASCENT INCREASING IN THE FORM OF
LOW-LEVEL WARM ADVECTION AND DPVA ASSOC/W SMALL AMPLITUDE
DISTURBANCES IN SW FLOW ALOFT. ALL OF THE 00Z GUIDANCE INDICATES
MEASURABLE PRECIP IN THE WESTERN PIEDMONT BY 12Z MON...AND THIS
SEEMS CONSISTENT WITH THE AFOREMENTIONED DISCUSSION. WILL INDICATE
PRECIP CHANCES INCREASING FROM THE WEST AFTER MIDNIGHT...RANGING
FROM 60-80% IN THE FAR WESTERN PIEDMONT TO ~20% ALONG THE I-95
CORRIDOR. EAST OF I-95...FORCING FOR ASCENT WILL BE MUCH WEAKER AND
PRECIP CHANCES WILL LARGELY BE TIED TO SHOWER ACTIVITY MOVING INLAND
FROM THE ATLANTIC IN ASSOC/W ONSHORE FLOW. AS A RESULT...WILL
INDICATE A DRY FCST IN THE FAR NE COASTAL PLAIN WITH A SLIGHT CHANCE
SOUTH OF HWY 64 IN THE SE COASTAL PLAIN.
THICKNESSES WILL BE SLIGHTLY LOWER (PERHAPS 5-10M) THAN TODAY.
THIS...ALONG WITH INCREASING CLOUD COVER DURING THE AFTERNOON SHOULD
RESULT IN HIGHS A FEW DEGREES COOLER THAN TODAY IN THE MID 80S
(84-88F)...COOLEST IN THE WESTERN PIEDMONT. LOWS SUN NIGHT WILL BE
TEMPERED BY CLOUD COVER AND A LIGHT SOUTHERLY BREEZE...IN THE UPPER
60S TO NEAR 70F IN THE SOUTH. -VINCENT
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
THE LATEST INFORMATION FROM THE NHC CONCERNING "KAREN" CONTINUES TO
DOWNGRADE THE TROPICAL SYSTEM. IT HAS BEEN DESCRIBED AS ALREADY
BEING `DECAPITATED" BY ONE FORECASTER - DUE TO STRONGER WINDS ALOFT.
THEREFORE... THE CONFIDENCE OF WHETHER ANY REMNANTS OF `KAREN" WILL
BE LEFT TO BRING INDIRECT IMPACTS (RAIN, SEVERE THREAT) FOR CENTRAL
NC BY EARLY NEXT WEEK HAS LOWERED.
ON A MORE CONFIDENT NOTE... A MID/UPPER LEVEL TROUGH IS FORECAST TO
BE APPROACHING THE APPALACHIANS MONDAY... THEN SWING ACROSS OUR
REGION TUE AND TUE NIGHT. THE MAIN UPPER DYNAMICS ARE FORECAST TO
PUSH FROM THE MIDWEST TO THE GREAT LAKES. HOWEVER... MOISTURE IS
EXPECTED TO SURGE NORTHWARD ALONG THE EASTERN SEABOARD BRINGING
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE COLD FRONT.
IF THE REMNANT LOW PRESSURE OF `KAREN` TRACKS NE INTO NC AS SOME OF
THE MODELS STILL SUGGEST... THERE CAN STILL BE ENHANCED RAINFALL FOR
12-24 HOURS. OTHERWISE... THIS WOULD BE A TYPICAL RAINFALL EVENT
ASSOCIATED WITH A MID-LATITUDE TROUGH EARLY NEXT WEEK.
ONCE THE TROUGH PASSES... CLEARING AND COOLER CONDITIONS ARE
EXPECTED MID THROUGH LATE WEEK. LOWS 50-55. HIGHS 70-75.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1000 AM SATURDAY...
24-HR TAF PERIOD:
VFR CONDITIONS AND WINDS UNDER 10KT WILL PREVAIL THE REMAINDER OF
THE TAF PERIOD. SURFACE WINDS MAY SHOW A NORTHERLY COMPONENT VEERING
GRADUALLY SOUTH DURING THE LATE MORNING AND EARLY AFTERNOON. LATE
TONIGHT...UNDER A MOSTLY CLEAR SKY...LIGHT SOUTHERLY WIND...AND
PERSISTENT LATE-NIGHT SURFACE DEW POINTS FROM 60 TO 65...EXPECT
AREAS OF FOG...WITH LOWEST VISIBILITIES TOWARD KFAY AND KRWI.
LOOKING AHEAD:
ASIDE FROM A POTENTIAL FOR FOG OR SUB-VFR CEILINGS BETWEEN 08-12Z
SUNDAY MORNING...VFR CONDS ARE EXPECTED TO PREVAIL DURING THE DAY
SUNDAY WITH CEILINGS SOMEWHAT LOWER THAN PREVIOUS DAYS (3500-4500 FT
AGL) IN ASSOC/W THE ONSET OF A LIGHT SOUTHERLY RETURN FLOW OVER
WESTERN PORTIONS OF THE STATE AS HIGH PRESSURE MOVES OFFSHORE.
EXPECT AN INCREASING CHANCE FOR MVFR/IFR CEILINGS AT ALL TERMINALS
IN ADVANCE OF A COLD FRONT PROGRESSING SLOWLY EAST TOWARD THE
SOUTHERN APPALACHIANS SUNDAY NIGHT...ALONG WITH AN INCREASING CHANCE
FOR RAIN AT THE INT/GSO TERMINALS BETWEEN 06-12Z MONDAY MORNING.
EXPECT WIDESPREAD SHOWERS/STORMS DURING THE DAY MONDAY AS THE COLD
FRONT TRACKS EAST INTO THE CAROLINAS. UNCERTAINTY IN THE FCST
INCREASES THEREAFTER...HOWEVER...IT IS POSSIBLE THAT RAIN AND
SUB-VFR CONDITIONS MAY PERSIST MONDAY NIGHT INTO TUESDAY. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...DJF/VINCENT
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...DJF/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
314 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL MOVE SLOWLY EAST OFFSHORE THE
CAROLINA COAST TONIGHT AND SUNDAY. A COLD FRONT WILL APPROACH THE
MOUNTAINS FROM THE WEST SUNDAY NIGHT...THEN TRACK EASTWARD THROUGH
THE CAROLINAS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM FRIDAY...
LITTLE CHANGE TO THE OVERNIGHT FORECAST NEEDED AS HIGH PRESSURE
REMAINS PERSISTENT OVER THE CAROLINAS. SKIES HAVE CLEARED AND
WINDS. DEWPOINTS HAVE RECOVERED ANOTHER 2 TO 4 DEGREES SINCE 24
HOURS AGO...MAINLY ACROSS THE SOUTH... AND DEWPOINT DEPRESSIONS ARE
ALREADY LESS THAN 5 DEGREES AT MANY OBSERVING SITES. RH CROSS
SECTIONS FAVOR SOUTHERN AREAS FOR FOG...AND THE RECENT HRRR RUNS
SUPPORT THIS. LOWS MOSTLY IN THE 60-63 RANGE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 255 PM FRIDAY...
SATURDAY AND SATURDAY NIGHT...HIGH PRESSURE PERSISTS...WITH
MID-LEVEL HEIGHTS ACTUALLY RISING FOR A TIME SATURDAY BEFORE
BEGINNING TO FALL AGAIN SATURDAY NIGHT. BUFR SOUNDINGS FROM BOTH THE
NAM AND THE GFS SUGGEST A COUPLE OF DEGREES OR SO OF WARMING ALOFT
AROUND 500MB SATURDAY...WITH SOME 850MB MOISTURE AVAILABLE ONCE
AGAIN SUGGESTIVE OF SOME DIURNAL CUMULUS WITH MIXING SATURDAY
MORNING INTO THE AFTERNOON. SUBSIDENCE CONTINUES TO DOMINATE...AND K
INDICES ACTUALLY FALL SOMEWHAT ON THE GFS DURING THE DAY SATURDAY.
ANOTHER DRY DAY ANTICIPATED WITH LIGHT WINDS EARLY INCREASING A
TOUCH...UNDER 10KT...AND SHOWING A SOUTHERLY COMPONENT BEFORE AGAIN
DIMINISHING TO FAIRLY LIGHT SOUTHERLY SATURDAY NIGHT. 1000-850MB
THICKNESSES SUPPORT HIGHS AROUND THE MOS GUIDANCE...MANY UPPER 80S
AND A FEW READINGS AT 90. AVAILABLE LOW-LEVEL MOISTURE SUPPORTS A
GREATER PROBABILITY OF AREAS OF FOG ACROSS CENTRAL NORTH CAROLINA
LATE SATURDAY NIGHT INTO SUNDAY MORNING...AND HAVE AGAIN CONTINUED
THIS IN THE GRIDDED AND WORDED FORECASTS. OVERNIGHT LOWS SATURDAY
NIGHT MAINLY LOWER 60S. -DJF
SUNDAY...WINDS ALOFT WILL BACK TO SOUTHWESTERLY AS THE MID-UPPER
RIDGE AXIS SHIFTS EAST AND OFFSHORE...WHICH WILL PROMOTE A GRADUAL
INCREASE IN MID TO ESPECIALLY HIGH LEVEL MOISTURE THROUGHOUT THE DAY
SUNDAY. THE COMBINATION OF THE INCREASING CLOUDS AND THE EASTWARD
DEPARTURE OF THE RIDGE ALOFT WILL LIKELY RESULT IN TEMPERATURES UP
TO A FEW DEGREES COOLER THAN THOSE OF SAT - OR WITHIN A COUPLE OF
DEGREES EITHER SIDE OF 85. THE TIGHTENING MSL PRESSURE GRADIENT IN
RETURN FLOW WILL ALSO PROMOTE THE DEVELOPMENT OF A SOUTHERLY BREEZE
THAT WILL PEAK IN THE 10-15 KT RANGE OVER THE WESTERN PIEDMONT
ACCORDING TO MIXED LAYER WINDS DEPICTED BY BUFR FORECAST SOUNDINGS.
DESPITE THE INCREASING MAINLY HIGH CLOUDS...PRECIPITATION CHANCES
WILL REMAIN RELATIVELY LOW. WILL ACCORDINGLY TRIM INHERITED
PRECIPITATION CHANCES AND CONFINE A SLIGHT CHANCE TO ROUGHLY THE
SOUTHERN HALF OF THE CWFA...TO ACCOUNT FOR THE PROPAGATION OF
SHOWERS THAT FORM OWING TO ONSHORE FLOW/FRICTIONAL CONVERGENCE AND
WEAK HEIGHT FALLS ALOFT...IN A WEAKLY INHIBITED AND UNSTABLE
ENVIRONMENT ALONG AND INVOF COASTAL AREAS. -MWS
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
THE LATEST INFORMATION FROM THE NHC CONCERNING "KAREN" CONTINUES TO
DOWNGRADE THE TROPICAL SYSTEM. IT HAS BEEN DESCRIBED AS ALREADY
BEING `DECAPITATED" BY ONE FORECASTER - DUE TO STRONGER WINDS ALOFT.
THEREFORE... THE CONFIDENCE OF WHETHER ANY REMNANTS OF `KAREN" WILL
BE LEFT TO BRING INDIRECT IMPACTS (RAIN, SEVERE THREAT) FOR CENTRAL
NC BY EARLY NEXT WEEK HAS LOWERED.
ON A MORE CONFIDENT NOTE... A MID/UPPER LEVEL TROUGH IS FORECAST TO
BE APPROACHING THE APPALACHIANS MONDAY... THEN SWING ACROSS OUR
REGION TUE AND TUE NIGHT. THE MAIN UPPER DYNAMICS ARE FORECAST TO
PUSH FROM THE MIDWEST TO THE GREAT LAKES. HOWEVER... MOISTURE IS
EXPECTED TO SURGE NORTHWARD ALONG THE EASTERN SEABOARD BRINGING
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE COLD FRONT.
IF THE REMNANT LOW PRESSURE OF `KAREN` TRACKS NE INTO NC AS SOME OF
THE MODELS STILL SUGGEST... THERE CAN STILL BE ENHANCED RAINFALL FOR
12-24 HOURS. OTHERWISE... THIS WOULD BE A TYPICAL RAINFALL EVENT
ASSOCIATED WITH A MID-LATITUDE TROUGH EARLY NEXT WEEK.
ONCE THE TROUGH PASSES... CLEARING AND COOLER CONDITIONS ARE
EXPECTED MID THROUGH LATE WEEK. LOWS 50-55. HIGHS 70-75.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...
24-HR TAF PERIOD:
FOG IS EXPECTED TO DEVELOP EARLY THIS MORNING IN ASSOCIATION WITH
CLEAR SKIES...CALM WINDS...AND A SEASONABLY MOIST AIRMASS. FOG WILL
BE MOST LIKELY AT THE FAY/RWI TERMINALS WHERE IFR-VLIFR VISBYS ARE
EXPECTED IN THE 08-12Z TIME FRAME...FOLLOWED BY RDU WHERE MVFR/IFR
VISBYS WILL BE POSSIBLE BETWEEN 08-12Z...AND FINALLY THE INT/GSO
TERMINALS WHERE MVFR VISBYS WILL BE POSSIBLE BETWEEN 09-12Z. FOG
WILL LIFT AND SCATTER OUT TO VFR BETWEEN 12-14Z...WITH VFR
CONDITIONS AND LIGHT WINDS THE REMAINDER OF THE TAF PERIOD.
LOOKING AHEAD:
ASIDE FROM A POTENTIAL FOR FOG OR SUB-VFR CEILINGS BETWEEN 08-12Z
SUNDAY MORNING...VFR CONDS ARE EXPECTED TO PREVAIL DURING THE DAY
SUNDAY WITH CEILINGS SOMEWHAT LOWER THAN PREVIOUS DAYS (3500-4500 FT
AGL) IN ASSOC/W A STRENGTHENING SOUTHERLY RETURN FLOW AS HIGH
PRESSURE MOVES OFFSHORE. EXPECT AN INCREASING CHANCE FOR MVFR/IFR
CEILINGS AT ALL TERMINALS IN ADVANCE OF A COLD FRONT PROGRESSING
SLOWLY EAST INTO THE SOUTHERN APPALACHIANS SUNDAY NIGHT...ALONG WITH
AN INCREASING CHANCE FOR RAIN AT THE INT/GSO TERMINALS BETWEEN
06-12Z MONDAY MORNING. EXPECT WIDESPREAD SHOWERS/THUNDERSTORMS
DURING THE DAY MONDAY AS THE COLD FRONT TRACKS EAST INTO THE
CAROLINAS. UNCERTAINTY IN THE FCST INCREASES THEREAFTER...
HOWEVER...IT IS POSSIBLE THAT RAIN AND SUB-VFR CONDITIONS PERSIST
MONDAY NIGHT INTO TUESDAY. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...SMITH
SHORT TERM...DJF/MWS
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO RESIDE OVER THE REGION THROUGH
SUNDAY. INCREASING MOISTURE AHEAD OF BOTH A COLD FRONT...AND
TROPICAL STORM KAREN...WILL SPREAD INTO THE REGION FOR THE START OF
THE NEXT WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM FRIDAY...
LITTLE CHANGE TO THE OVERNIGHT FORECAST NEEDED AS HIGH PRESSURE
REMAINS PERSISTENT OVER THE CAROLINAS. SKIES HAVE CLEARED AND
WINDS. DEWPOINTS HAVE RECOVERED ANOTHER 2 TO 4 DEGREES SINCE 24
HOURS AGO...MAINLY ACROSS THE SOUTH... AND DEWPOINT DEPRESSIONS ARE
ALREADY LESS THAN 5 DEGREES AT MANY OBSERVING SITES. RH CROSS
SECTIONS FAVOR SOUTHERN AREAS FOR FOG...AND THE RECENT HRRR RUNS
SUPPORT THIS. LOWS MOSTLY IN THE 60-63 RANGE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 255 PM FRIDAY...
SATURDAY AND SATURDAY NIGHT...HIGH PRESSURE PERSISTS...WITH
MID-LEVEL HEIGHTS ACTUALLY RISING FOR A TIME SATURDAY BEFORE
BEGINNING TO FALL AGAIN SATURDAY NIGHT. BUFR SOUNDINGS FROM BOTH THE
NAM AND THE GFS SUGGEST A COUPLE OF DEGREES OR SO OF WARMING ALOFT
AROUND 500MB SATURDAY...WITH SOME 850MB MOISTURE AVAILABLE ONCE
AGAIN SUGGESTIVE OF SOME DIURNAL CUMULUS WITH MIXING SATURDAY
MORNING INTO THE AFTERNOON. SUBSIDENCE CONTINUES TO DOMINATE...AND K
INDICES ACTUALLY FALL SOMEWHAT ON THE GFS DURING THE DAY SATURDAY.
ANOTHER DRY DAY ANTICIPATED WITH LIGHT WINDS EARLY INCREASING A
TOUCH...UNDER 10KT...AND SHOWING A SOUTHERLY COMPONENT BEFORE AGAIN
DIMINISHING TO FAIRLY LIGHT SOUTHERLY SATURDAY NIGHT. 1000-850MB
THICKNESSES SUPPORT HIGHS AROUND THE MOS GUIDANCE...MANY UPPER 80S
AND A FEW READINGS AT 90. AVAILABLE LOW-LEVEL MOISTURE SUPPORTS A
GREATER PROBABILITY OF AREAS OF FOG ACROSS CENTRAL NORTH CAROLINA
LATE SATURDAY NIGHT INTO SUNDAY MORNING...AND HAVE AGAIN CONTINUED
THIS IN THE GRIDDED AND WORDED FORECASTS. OVERNIGHT LOWS SATURDAY
NIGHT MAINLY LOWER 60S. -DJF
SUNDAY...WINDS ALOFT WILL BACK TO SOUTHWESTERLY AS THE MID-UPPER
RIDGE AXIS SHIFTS EAST AND OFFSHORE...WHICH WILL PROMOTE A GRADUAL
INCREASE IN MID TO ESPECIALLY HIGH LEVEL MOISTURE THROUGHOUT THE DAY
SUNDAY. THE COMBINATION OF THE INCREASING CLOUDS AND THE EASTWARD
DEPARTURE OF THE RIDGE ALOFT WILL LIKELY RESULT IN TEMPERATURES UP
TO A FEW DEGREES COOLER THAN THOSE OF SAT - OR WITHIN A COUPLE OF
DEGREES EITHER SIDE OF 85. THE TIGHTENING MSL PRESSURE GRADIENT IN
RETURN FLOW WILL ALSO PROMOTE THE DEVELOPMENT OF A SOUTHERLY BREEZE
THAT WILL PEAK IN THE 10-15 KT RANGE OVER THE WESTERN PIEDMONT
ACCORDING TO MIXED LAYER WINDS DEPICTED BY BUFR FORECAST SOUNDINGS.
DESPITE THE INCREASING MAINLY HIGH CLOUDS...PRECIPITATION CHANCES
WILL REMAIN RELATIVELY LOW. WILL ACCORDINGLY TRIM INHERITED
PRECIPITATION CHANCES AND CONFINE A SLIGHT CHANCE TO ROUGHLY THE
SOUTHERN HALF OF THE CWFA...TO ACCOUNT FOR THE PROPAGATION OF
SHOWERS THAT FORM OWING TO ONSHORE FLOW/FRICTIONAL CONVERGENCE AND
WEAK HEIGHT FALLS ALOFT...IN A WEAKLY INHIBITED AND UNSTABLE
ENVIRONMENT ALONG AND INVOF COASTAL AREAS. -MWS
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...
THE LATEST INFORMATION FROM THE NHC CONCERNING "KAREN" CONTINUES TO
DOWNGRADE THE TROPICAL SYSTEM. IT HAS BEEN DESCRIBED AS ALREADY
BEING `DECAPITATED" BY ONE FORECASTER - DUE TO STRONGER WINDS ALOFT.
THEREFORE... THE CONFIDENCE OF WHETHER ANY REMNANTS OF `KAREN" WILL
BE LEFT TO BRING INDIRECT IMPACTS (RAIN, SEVERE THREAT) FOR CENTRAL
NC BY EARLY NEXT WEEK HAS LOWERED.
ON A MORE CONFIDENT NOTE... A MID/UPPER LEVEL TROUGH IS FORECAST TO
BE APPROACHING THE APPALACHIANS MONDAY... THEN SWING ACROSS OUR
REGION TUE AND TUE NIGHT. THE MAIN UPPER DYNAMICS ARE FORECAST TO
PUSH FROM THE MIDWEST TO THE GREAT LAKES. HOWEVER... MOISTURE IS
EXPECTED TO SURGE NORTHWARD ALONG THE EASTERN SEABOARD BRINGING
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ALONG THE COLD FRONT.
IF THE REMNANT LOW PRESSURE OF `KAREN` TRACKS NE INTO NC AS SOME OF
THE MODELS STILL SUGGEST... THERE CAN STILL BE ENHANCED RAINFALL FOR
12-24 HOURS. OTHERWISE... THIS WOULD BE A TYPICAL RAINFALL EVENT
ASSOCIATED WITH A MID-LATITUDE TROUGH EARLY NEXT WEEK.
ONCE THE TROUGH PASSES... CLEARING AND COOLER CONDITIONS ARE
EXPECTED MID THROUGH LATE WEEK. HOWEVER... THE 00Z/05 OCTOBER
OPERATIONAL EC SUGGESTS THE FRONT MAY HANG UP OVER SC/GA WED... WITH
THE MID/UPPER TROUGH HANGING BACK OVER THE SE STATES INTO THURS. WE
WILL INCORPORATE A LOW PERCENTAGE OF THIS SOLUTION INTO THE FORECAST
AT THE CURRENT TIME. THIS WOULD YIELD PARTLY CLOUDY SKIES IN THE
EAST AND SOUTH LATE TUE AND WED. LOWS 50-55. HIGHS 70-75.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 745 PM FRIDAY...
AREAS OF FOG ARE EXPECTED DEVELOP LATE TONIGHT BETWEEN 06 TO
12Z......WITH THE HIGHEST PROBABILITY AND CORRESPONDINGLY LOWER
VISIBILITIES EXPECTED IN THE EAST AT KRWI AND KFAY.
BEYOND THE 18Z VALID TAF PERIOD...AREAS OF FOG WILL BE POSSIBLE
AGAIN EARLY SUNDAY MORNING...OTHERWISE EXPECT PREDOMINATELY VFR
CONDITIONS THROUGH THE WEEKEND. MOISTURE ASSOCIATED WITH REMNANTS
OF TS KAREN WILL SPREAD INTO THE AREA LATE SUNDAY NIGHT AND INTO
MONDAY. SUB-VFR CONDITIONS WILL BE POSSIBLE AGAIN LATE SUNDAY NIGHT
AND MONDAY MORNING WITH WIDESPREAD SHOWERS AND STORMS MONDAY
AFTERNOON THROUGH MONDAY NIGHT WITH CORRESPONDING AREAS OF SUB-VFR
CONDITIONS. WIDESPREAD VFR CONDITIONS ARE LIKELY TO RETURN BY
TUESDAY AFTERNOON AS A COLD FRONT PUSHES EAST AND OFFSHORE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...SMITH
SHORT TERM...DJF/MWS
LONG TERM...BADGETT
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
146 PM EDT SAT OCT 5 2013
.SYNOPSIS...
SOUTHWEST FLOW OF WARM...MUGGY AIR CONTINUES INTO SUNDAY. COLD FRONT
BRINGS SHOWERS ALONG WITH SOME STORMS LATE SUNDAY INTO MONDAY.
UPPER LOW PULLS OUT MIDWEEK...YIELDING TO HIGH PRESSURE LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
A FEW SMALL WAVES EMBEDDED WITHIN THE UPPER RIDGE HAVE SPARKED
SOME CONVECTION OVER THE OHIO VALLEY THIS MORNING...BUT THIS IS
NOT ABLE TO GET MUCH IN TERMS OF VERTICAL EXTENT. HAD TO DRAG THE
POPS A LITTLE FURTHER TO THE SOUTHEAST...BUT LEFT THEM OUT OF CRW.
WILL REASSESS WHEN THE NEW MODELS ARE IN. HRRR HAS BEEN VALUABLE
THIS MORNING.
PREVIOUS DISCUSSION...
SUMMER REPRISE CONTINUES. ALTOCU THIS MORNING AIDS IN ERADICATING
THE DENSE VALLEY FOG OF EARLY MORNING...OR HOLDS IT IN IF IT
SURVIVES DAWN....AND CU THIS AFTERNOON IN VERY WARM AND HUMID SW
FLOW AS UPPER RIDGE MOVES E ACROSS AREA. WEAK RIPPLES IN THE UPPER
LEVEL SW FLOW ONCE THE RIDGE GOES BY COULD GRAZE NW PORTION OF AREA
WITH CONVECTION MIDDAY TODAY INTO THIS EVENING.
FLOW GOES MORE SOUTHERLY TONIGHT...SO CONVECTION ASSOCIATED WITH
RIPPLES IN FLOW WILL SHIFT N OF THE AREA WHILE THAT ASSOCIATED WITH
COLD FRONT TO THE W REMAINS W OF THE AREA THROUGH 12Z SUN. ALTOCU
LIMITED TO THE W. BOUNDARY LATER FLOW SHOULD PRECLUDE DENSE VALLEY
FOG SAVE FOR THE DEEPER VALLEYS OF EASTERN WV LATE TONIGHT.
ROLLED WITH BIAS CORRECTED ADJMET AND BIAS CORRECTED ALL BLEND
TOGETHER WITH PREVIOUS FOR HIGHS TODAY WITH ADJMAV BEING TOO HIGH.
LOWER TO MID 80S LOWLANDS IS 5-10F BELOW RECORD HIGHS. DID BLEND IN
BIAS CORRECTED ADJMAV FOR LOWS TONIGHT...A TICK OR SO HIGHER THAN
PREVIOUS ON RIDGE/HILL TOPS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
UNSETTLED WEATHER IN THE SHORT TERM PERIOD. RATHER WARM AND HUMID
DAY ON TAP SUNDAY...AS UPPER LOW ACROSS CENTRAL U.S. DIGS SOUTH AND
EAST...CAUSING FLOW TO BACK...AND SLOWING THE PROGRESSION OF THE
COLD FRONT AND ASSOCIATED PRECIPITATION INTO THE CWA. STILL
EXPECTING SOME DECENT RAINFALL TOTALS...AS LLJ AIDS IN MOISTURE
TRANSPORT TO THE REGION...WITH PW VALUES EXPECTED TO RISE TO 1.6 TO
1.7 INCHES. AS WITH PREVIOUS FORECASTER...WILL LEAVE A MENTION OF
WATER PROBLEMS OUT OF THE HWO DUE TO RECENT DRY SPELL...AND OVERALL
PROGRESSIVE NATURE OF THE SYSTEM. IN ADDITION...AT THIS POINT...SPC
HAS ISSUED ONLY A SEE TEXT AREA FOR THE CWA...AS CLOUD COVER...AND
OVERALL LACK OF INSTABILITY SHOULD HOPEFULLY LIMIT THE SEVERE
POTENTIAL ACROSS THE REGION. STILL...EXPECTING SOME RATHER GUSTY
CONDITIONS ASSOCIATED WITH FRONTAL PASSAGE...SET TO TAKE PLACE ON
MONDAY...PARTICULARLY ACROSS HIGHER ELEVATIONS. HOWEVER...THIS WILL
NEED TO BE MONITORED AS MODELS ARE INDICATING STRONG FORCING WITH
THE FRONT. MODELS CONTINUE TO INDICATE THAT REMNANTS OF KAREN WILL
REMAIN FAR ENOUGH TO THE EAST OF THE AREA...THAT THE CWA WILL SEE
LITTLE TO NO EFFECT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
LOOKING AT UPR RIDGE TO BUILD ACROSS EASTERN CONUS IN THE EXTENDED
WITH STALLED SFC FRONT LINGERING ALONG E COAST. SEASONABLE TEMPS
DURING THE DAY AND COOL NIGHTS ON TAP.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONVECTION EXPECTED OVER THE OHIO VALLEY AGAIN TODAY...WITH
ISOLATED CHANCES IN THE MOUNTAINS. ONLY HAVE VCTS IN THE PKB AREA
GIVEN THE CURRENT SET OF POP GRIDS IN PLACE...WHERE THESE VALUES
ARE THE HIGHEST. A FEW SHOWERS MAY LINGER AROUND HTS AS WELL...BUT
THE BULK OF THE ACTIVITY SHOULD REMAIN CLOSER TO ILN/CMH/ZZV.
DID NOT GO WITH MUCH FOG TONIGHT AS RH PROGS HAVE DEPTH OF THE
MOISTURE EXTENDING THROUGH 550MB...ALLUDING TO CLOUD COVER IN
PLACE. EKN MAY GET LIFR LATE TONIGHT WHERE THE CLOUD COVER IS NOT
EXPECTED TO BE AS PROMINENT.
WITH THE FRONTAL SYSTEM GETTING CLOSER...WILL SEE SURFACE FLOW
AROUND 10KTS OUT OF THE SOUTHWEST SUNDAY. AIR FLOW OFF THE SURFACE
WILL BE HIGHER WITH THE APPROACH OF THE LOW LEVEL JET. TRI
STATE/SOUTHEAST OHIO LOCATIONS COULD SEE 40-50KTS OFF THE SURFACE
AT AROUND 5KFT...ALSO OUT OF THE SOUTHWEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: MAY NEED VCSH AT HTS THIS AFTERNOON. BRIEF
RAIN IS POSSIBLE AT BOTH PKB/HTS. EKN MAY NOT FOG TONIGHT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z SUNDAY...
IFR POSSIBLE ALONG COLD FRONT...MOVING W TO E...SUN NT INTO
MON...AND IN POST-RAIN FOG/STRATUS TUE MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM/26
SHORT TERM...SL
LONG TERM...30
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1038 AM EDT SAT OCT 5 2013
.SYNOPSIS...
SOUTHWEST FLOW OF WARM...MUGGY AIR CONTINUES INTO SUNDAY. COLD FRONT
BRINGS SHOWERS ALONG WITH SOME STORMS LATE SUNDAY INTO MONDAY.
UPPER LOW PULLS OUT MIDWEEK...YIELDING TO HIGH PRESSURE LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
A FEW SMALL WAVES EMBEDDED WITHIN THE UPPER RIDGE HAVE SPARKED
SOME CONVECTION OVER THE OHIO VALLEY THIS MORNING...BUT THIS IS
NOT ABLE TO GET MUCH IN TERMS OF VERTICAL EXTENT. HAD TO DRAG THE
POPS A LITTLE FURTHER TO THE SOUTHEAST...BUT LEFT THEM OUT OF CRW.
WILL REASSESS WHEN THE NEW MODELS ARE IN. HRRR HAS BEEN VALUABLE
THIS MORNING.
PREVIOUS DISCUSSION...
SUMMER REPRISE CONTINUES. ALTOCU THIS MORNING AIDS IN ERADICATING
THE DENSE VALLEY FOG OF EARLY MORNING...OR HOLDS IT IN IF IT
SURVIVES DAWN....AND CU THIS AFTERNOON IN VERY WARM AND HUMID SW
FLOW AS UPPER RIDGE MOVES E ACROSS AREA. WEAK RIPPLES IN THE UPPER
LEVEL SW FLOW ONCE THE RIDGE GOES BY COULD GRAZE NW PORTION OF AREA
WITH CONVECTION MIDDAY TODAY INTO THIS EVENING.
FLOW GOES MORE SOUTHERLY TONIGHT...SO CONVECTION ASSOCIATED WITH
RIPPLES IN FLOW WILL SHIFT N OF THE AREA WHILE THAT ASSOCIATED WITH
COLD FRONT TO THE W REMAINS W OF THE AREA THROUGH 12Z SUN. ALTOCU
LIMITED TO THE W. BOUNDARY LATER FLOW SHOULD PRECLUDE DENSE VALLEY
FOG SAVE FOR THE DEEPER VALLEYS OF EASTERN WV LATE TONIGHT.
ROLLED WITH BIAS CORRECTED ADJMET AND BIAS CORRECTED ALL BLEND
TOGETHER WITH PREVIOUS FOR HIGHS TODAY WITH ADJMAV BEING TOO HIGH.
LOWER TO MID 80S LOWLANDS IS 5-10F BELOW RECORD HIGHS. DID BLEND IN
BIAS CORRECTED ADJMAV FOR LOWS TONIGHT...A TICK OR SO HIGHER THAN
PREVIOUS ON RIDGE/HILL TOPS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
UNSETTLED WEATHER IN THE SHORT TERM PERIOD. RATHER WARM AND HUMID
DAY ON TAP SUNDAY...AS UPPER LOW ACROSS CENTRAL U.S. DIGS SOUTH AND
EAST...CAUSING FLOW TO BACK...AND SLOWING THE PROGRESSION OF THE
COLD FRONT AND ASSOCIATED PRECIPITATION INTO THE CWA. STILL
EXPECTING SOME DECENT RAINFALL TOTALS...AS LLJ AIDS IN MOISTURE
TRANSPORT TO THE REGION...WITH PW VALUES EXPECTED TO RISE TO 1.6 TO
1.7 INCHES. AS WITH PREVIOUS FORECASTER...WILL LEAVE A MENTION OF
WATER PROBLEMS OUT OF THE HWO DUE TO RECENT DRY SPELL...AND OVERALL
PROGRESSIVE NATURE OF THE SYSTEM. IN ADDITION...AT THIS POINT...SPC
HAS ISSUED ONLY A SEE TEXT AREA FOR THE CWA...AS CLOUD COVER...AND
OVERALL LACK OF INSTABILITY SHOULD HOPEFULLY LIMIT THE SEVERE
POTENTIAL ACROSS THE REGION. STILL...EXPECTING SOME RATHER GUSTY
CONDITIONS ASSOCIATED WITH FRONTAL PASSAGE...SET TO TAKE PLACE ON
MONDAY...PARTICULARLY ACROSS HIGHER ELEVATIONS. HOWEVER...THIS WILL
NEED TO BE MONITORED AS MODELS ARE INDICATING STRONG FORCING WITH
THE FRONT. MODELS CONTINUE TO INDICATE THAT REMNANTS OF KAREN WILL
REMAIN FAR ENOUGH TO THE EAST OF THE AREA...THAT THE CWA WILL SEE
LITTLE TO NO EFFECT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
LOOKING AT UPR RIDGE TO BUILD ACROSS EASTERN CONUS IN THE EXTENDED
WITH STALLED SFC FRONT LINGERING ALONG E COAST. SEASONABLE TEMPS
DURING THE DAY AND COOL NIGHTS ON TAP.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
FOG WAS MORE LIMITED EARLY THIS MORNING COMPARED WITH FRI MORNING
AND WILL BE EVEN MORE LIMITED SUN MORNING GIVEN ANOTHER DAY OF LOW
SHOWER/THUNDERSTORM COVERAGE...AND SOMEWHAT INCREASED BOUNDARY LAYER
FLOW. AS FOR THIS MORNING...THE FOG WILL FINISH THINNING OUT 13-14Z.
CIRRUS AND ALTOCU MOVING ACROSS THIS MORNING FOLLOWED BY A BUILDING
CU FIELD THIS AFTERNOON. SHOWERS AND THUNDERSTORMS COULD AFFECT THE
MIDDLE OHIO VALLEY MIDDAY TODAY INTO THIS EVENING. AN ISOLATED
SHOWER OR THUNDERSTORM COULD ALSO POP UP OVER THE NORTHERN WV
MOUNTAINS THIS AFTERNOON.
LIGHT AND VARIABLE SFC FLOW TODAY BECOMES LIGHT S TO SE TONIGHT
WHILE LIGHT NW FLOW ALOFT SWITCHES TO LIGHT SW THIS MORNING AND THEN
BECOMES LIGHT S TO SW TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: LITTLE MORE THEN MINOR VARIATIONS ARE EXPECTED
IN THE FCST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z SUNDAY...
IFR POSSIBLE ALONG COLD FRONT...MOVING W TO E...SUN NT INTO
MON...AND IN POST-RAIN FOG/STRATUS TUE MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM/26
SHORT TERM...SL
LONG TERM...30
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS TULSA OK
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.
&&
$$
LONG TERM....07
AREA FORECAST DISCUSSION
NWS TULSA OK
1141 PM CDT FRI OCT 4 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
LEAD EDGE OF SHOWES/THUNDERSTORMS IS CURRENTLY MOVING
INTO NE OKLAHOMA...AND WILL IMPACT THE KBVO/KTUL AND KRVS
TAF SITES THROUGH ABOUT 09-10Z. THIS ACTIVITY SHOULD
APPROACH SE OKLAHOMA AND NW ARKANSAS LATER TONIGHT TOWARD
10-12Z. OVERALL THUNDERSTORM INTENSITY WILL CONTINUE TO
DECREASE. EXPECT AREAS OF MVFR CONDITIONS IN THE STRONGER
STORMS.
&&
.PREV DISCUSSION... /ISSUED 910 PM CDT FRI OCT 4 2013/
..UPDATE...
DISCUSSION...
THUNDERSTORMS CONTINUED TO RIDE ALONG THE INITIAL WIND SHIFT OF
THE COLD FRONT THIS EVENING FROM SOUTHWEST OKLAHOMA TO JUST WEST OF
OSAGE COUNTY AS OF 9 PM THIS EVENING. THE DRIER AIR REMAINED
FURTHER WEST ACROSS NORTHWEST OKLAHOMA. THESE THUNDERSTORMS WILL
PUSH INTO THE CWA OVER THE NEXT HOUR AS THE FRONT CONTINUES TO
PUSH EAST SOUTHEASTWARD. WITH THE LOSS OF DAYTIME HEATING THE CAP
HAS BEGUN TO STRENGHTEN ACROSS THE CWA...HOWEVER DEEP LAYER SHEAR
NEAR AND JUST BEHIND THE FRONT WILL ALLOW FOR THE POTENTIAL FOR
SOME STORMS TO BECOME STRONG TO SEVERE. LARGE HAIL AND STRONG
WINDS CONTINUE TO BE THE MAIN THREATS WITH THIS ACTIVITY. GREATEST
POTENTIAL FOR ANY SEVERE STORMS LOOKS TO BE MAINLY NORTHWEST OF
INTERSTATE 44 OVER THE NEXT FEW HOURS. THE SEVERE THUNDERSTORM
WATCH FOR OSAGE AND PAWNEE COUNTIES REMAINS IN EFFECT UNTIL 3Z.
LATEST RUNS OF THE HRRR AND THE LOCAL IN-HOUSE MODEL INDICATE THAT
THUNDERSTORMS COULD BE NEAR EAST CENTRAL OKLAHOMA BY 06Z AND INTO
SOUTHEAST OKLAHOMA AND NORTHWEST ARKANSAS BY 9Z. INSTABILITY
ACROSS THE REST OF THE CWA SHOULD WEAKEN OVERNIGHT AS THE CAP
CONTINUES TO STRENGHTEN...THOUGH AN ISOLATED STRONG TO SEVERE
STORM COULD BE POSSIBLE.
GUSTY NORTHWESTERLY WINDS IN THE 20 TO 30 MPH RANGE HAVE BEEN
OBSERVED BEHIND THE FRONT WITHIN THE DRIER/COOLER AIR AND WILL
CONTINUE TO FILTER INTO THE REGION OVERNIGHT. TEMPERATURES BY
EARLY SATURDAY MORNING LOOK BE AROUND 50 TO LOWER 50S NEAR THE
KANSAS BORDER TO THE 60S FOR FAR SOUTHEAST OKLAHOMA AND WEST
CENTRAL ARKANSAS. EVENING UPDATE WILL BE TO ADJUST POPS/WX/SKY
GRIDS BASED ON LATEST TRENDS AND TIMING...WHILE THE REST OF THE
FORECAST SEEMS TO BE HANDLING WELL AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 54 64 47 68 / 90 20 10 0
FSM 70 73 46 68 / 80 70 10 0
MLC 59 60 44 70 / 90 60 10 0
BVO 52 65 43 66 / 80 20 10 0
FYV 63 65 42 63 / 80 80 10 10
BYV 66 68 44 62 / 80 80 10 10
MKO 57 59 45 68 / 90 60 10 0
MIO 53 61 43 64 / 90 50 10 10
F10 55 60 46 69 / 90 40 10 0
HHW 71 73 46 72 / 80 50 10 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...18
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1023 PM EDT SUN OCT 6 2013
.SYNOPSIS...
THE REGION REMAINS IN THE WARM SECTOR OF A LOW MOVING THROUGH THE
UPPER GR LAKES. THE ASSOCIATED COLD FRONT WILL MOVE THROUGH ON
MONDAY AS TROPICAL MOISTURE FLOWS UP INTO THE STATE. HIGH PRESSURE
IS EXPECTED TO RETURN FOR TUESDAY AND KEEP MAINLY FAIR WEATHER
OVER THE FORECAST AREA THROUGH THE REST OF THE NEW WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE COLD FRONT IS MOVING INTO EASTERN OHIO ACCOMPANIED BY AN AREA
OF HEAVY RAIN SHOWERS AND ISOLATED THUNDERSTORMS. LOCALLY...THE
CWA IS DRY AND QUITE MILD. HAVEN`T REALLY CHANGED MUCH OF THE
FORECAST DURING THE OVERNIGHT...STILL LOOKS GOOD FOR RAIN TO BE
MOVING INTO WESTERN AREAS AROUND OR SHORTLY AFTER 06Z...AND
SPREADING QUICKLY EAST AFTER THAT.
THE STRONG...SOUTHERLY LLJ WILL SHIFT EAST FROM THE OHIO VALLEY
AND INTO THE REGION OVERNIGHT. THIS WILL QUICKLY INCREASE SFC
WINDS...WITH THE HIGHER TERRAIN AND LOCATIONS NORTH OF GAPS IN THE
RIDGES SEEING WIND GUSTS OVER 30 MPH.
INCREASED LARGE SCALE LIFT ASSOCIATED WITH THIS LLJ AND A SERIES
OF UPPER SHORT WAVES LIFTING QUICKLY NNE AHEAD OF THE MAIN OHIO
VALLEY TROUGH AND SFC COLD FRONT WILL LEAD TO THE DEVELOPMENT OF
NUMEROUS SHOWERS AND EMBEDDED LOW TOPPED TSRA OVER THE WESTERN
PA AFTER MIDNIGHT. THIS CONVECTION MAY REACH THE I-99/RT 220
CORRIDOR BETWEEN 10-12Z MONDAY.
LOOK FOR ONE MORE NIGHT OF UNSEASONABLY MILD TEMPS WITH LOW IN THE
60-65F RANGE...THANKS TO SIMILARLY HIGH DEWPOINTS...AND THE
INCREASING CLOUDS/WIND.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE MAIN ACTION OF THE WEEK AHEAD WILL BE CAPTURED IN THIS PERIOD AS
A RELATIVELY STRONG SFC COLD FRONT PUSHES EAST ACROSS THE
COMMONWEALTH. A HIGHLY ANOMALOUS SOUTHERLY LLJ /50KTS AND PLUS 3-4
SIGMA VIA THE 09Z AND 12Z SREF AND GEFS/ WILL SLIDE EAST ALONG AND
AHEAD OF THE FRONT MONDAY MORNING INTO EARLY MONDAY AFTERNOON.
EVEN THE SEEMINGLY HARMLESS /AND LOW/ FEW TO SEVERAL HUNDRED JOULES
OF SFC-BASED CAPE GENERATED IN THE MAINLY CLOUDY AIRMASS AHEAD OF
THE FRONT WILL BE ENOUGH TO COMBINE WITH THE STRONG DEEP-LAYER SHEAR
TO POSE THE THREAT FOR A NCFRB AND A FEW SWATHS OF STRONG/DAMAGING
STRAIGHT LINE WINDS.
THE SHARPLY VEERING AND VERY STRONG LLVL WIND PROFILE WILL ALSO
YIELD HIGH 0-3KM HELICITY OF 250-350 M2/S2...WHICH WILL BE CAPABLE
OF SUPPORTING SOME LOW-TOPPED AND FAST NEWD MOVING MINI SUPERCELLS
WELL AHEAD OF THE COLD FRONT /AND A FEW BKN-S SIGNATURES WITHIN THE
NCFRB/.
HIGH TEMPS WILL BE REACHED EARLY IN THE DAY ACROSS THE WEST...AND
EARLY AFTERNOON ACROSS THE SUSQ VALLEY WITH FEW TO SVRL DEG DIP IN
TEMPS BEHIND THE FRONT.
BEST WIND GUST POTENTIAL WILL BE ALONG AND AHEAD OF THE COLD FRONT
WITH A GUSTY /BUT NOT IMPRESSIVE/ WESTERLY FLOW BEHIND THE
FRONT.
STORM TOTAL RAINFALL WILL LIKELY RANGE FROM 1 TO 1.5 INCHES IN MOST
LOCATIONS...WHICH IS A DEFINITE DOWNWARD ADJUSTMENT FROM THE PAST
FEW DAYS GIVEN THE FACT THAT THERE WILL BE VERY LITTLE INFLUENCE
FROM THE REMNANTS OF TS KAREN THAT WILL WEAKEN FURTHER OVER THE NEXT
36 HOURS OVER THE SERN STATES.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
THE MODELS CONTINUE TO BE IN AGREEMENT WITH A NEARLY NEUTRAL TROUGH
EXTENDING FROM THE LOW CENTER THAT CONTINUES TO MOVE NORTHWARD.
COOLER AIR WILL ADVECT INTO THE REGION BEHIND THE FRONT MONDAY
NIGHT...AS ANY LINGERING SHOWERS SHOULD BE GONE BY 06Z TUESDAY.
THE PATTERN FLATTENS OUT QUICKLY TUESDAY MORNING AS SURFACE HIGH
PRESSURE SETTLES IN FOR THE LONG HAUL ON TUESDAY. THE UPPER RIDGE
RE-ASSERTS IT/S STRENGTH OVER THE ERN U.S. TEMPERATURES WILL BE
COOLER THAN NORMAL ON TUESDAY...WITH MORE SEASONABLE TEMPS THROUGH
THE REST OF THE WEEK. WITH THE DRY AIR AND SUBSIDENCE EVERY
MORNING...IT WILL BE A CLASSIC SET-UP FOR VERY CHILLY MORNINGS.
HOWEVER...THE ABNORMALLY HIGH 5H HEIGHTS...8H TEMPS OF 10 TO 12C AND
THICKNESSES IN THE MID 560S WILL PRECLUDE ALL BE THE VERY COLDEST
LOCATIONS FROM GETTING NEAR FREEZING AT NIGHT. THE COLDEST TIME
FRAME WILL BE TUESDAY NIGHT/WED MORNING. FROST IS POSSIBLE ACROSS
THE NORTH. RESIDUAL MOISTURE MOVING ONSHORE...ALONG WITH A WEAK SFC
LOW COULD ALLOW FOR EASTERLY FLOW LATE THURSDAY INTO FRIDAY.
THIS MOIST ONSHORE FLOW COULD BRING ISOLATED SHOWERS THURSDAY NIGHT
THROUGH FRIDAY AFTERNOON TO THE LOWER SUSQUEHANNA VALLEY.
THIS LOW PRESSURE SFC/ALOFT WILL CONTINUE TO DEVELOP OVER THE
WESTERN ATLANTIC UNDER THE UPPER RIDGE AND WILL CONTINUE TO
RETROGRADE INTO SATURDAY...BEFORE DRIFTING OUT TO SEA. HAVE
SLIGHTLY INCREASED POPS IN THE SOUTHEAST DURING THIS TIMEFRAME.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
WIDESPREAD VFR CONDITIONS ACROSS CENTRAL PA THIS EVENING AS REGION
REMAINS IN WARM SECTOR...AWAITING ARRIVAL OF A COLD FRONT LATE
TONIGHT/EARLY MON.
BIGGEST AVIATION CONCERN THROUGH EVENING HOURS WILL BE A GUSTY
S/SE WIND...PEAKING AT AROUND 25 MPH AT TIMES. MOIST FLOW IS
ALLOWING A MARINE LAYER FROM THE ATLANTIC TO PUSH NORTHWESTWARD
ACROSS CWA...RAISING DEWPOINTS BY NEARLY 10F. BIGGER IMPACTS OF
THIS MARINE LAYER WILL BE SEEN LATER TONIGHT...AS POTENT
SOUTHERLY LOW-LEVEL JET SLIDES EAST FROM OHIO VALLEY...PROVIDING
THE LIFT TO INITIATE DEVELOPMENT OF AN IFR STRATOCU DECK AS
CONDITIONS DETERIORATE AHEAD OF APPROACHING TROUGH. SCT SHOWERS
POSS IN THE VERY MOIST AIR OVER E PA AND THE SUSQ VALLEY AFTER 08Z
AS LARGE SCALE LIFT BEGINS TO INCREASE...AND THESE SHOWERS ARE
HINTED AT IN THE HRRR MODEL FORECAST. SO ADDED VCSH TO EASTERN
TERMINALS OVERNIGHT.
THEN FOCUS TURNS TO POTENT SFC COLD FRONT EXPECTED TO BE NEAR A
KBFD TO KJST LINE BY 12Z...AND PUSHING STEADILY EAST ACROSS THE
REST OF THE REGION DURING THE LATE MORNING AND EARLY AFTERNOON
HOURS. A NARROW LINE /ABOUT 4 HOURS/ OF HEAVY SHOWERS/LOW-TOPPED
TSRA SHOULD ACCOMPANY THE IMMEDIATE CFROPA...WHILE ISOLATED
SUPERCELLS ARE POSSIBLE WELL TO THE EAST OF THE FRONT IN THE
HIGHLY SHEARED ENVIRONMENT /MAINLY AFTER SUNRISE IN EASTERN
SECTIONS/. THESE INDIVIDUAL CELLS WILL TRACK RAPIDLY TO THE NE AT
40 KTS PLUS. ANY OF THESE LEAD STORMS /OR THE EXPECTED LINE ALONG
THE FRONT/ COULD MIX DOWN STRONG WIND GUSTS TO THE SFC.
CONDITIONS IMPROVE FROM WEST TO EAST WITHIN A FEW HOURS OF
FROPA AS PRECIP COMES TO AN END AND CEILINGS/VSBYS RETURN TO VFR
FOR THE SECOND HALF OF MON /AS RIDGING BEGINS IN LOWER LEVELS/.
WINDS TURN WESTERLY AND REMAIN AROUND 15 MPH GUSTING TO 25 MPH
BEFORE DIMINISHING LATER IN THE DAY.
CIG RESTRICTIONS LIKELY IN WESTERN/NORTHERN MTNS MON NIGHT AS
COLDEST MID LEVEL AIR RETREATS TO THE NE AND LOW LEVEL SUBSIDENCE
INVERSION SQUEEZES MOISTURE INTO A STABLE STRATOCU DECK.
OUTLOOK...
TUE...SCT AM SHOWERS/LOW CIGS POSSIBLE N AND W.
WED-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...DANGELO/CERU
AVIATION...LAMBERT/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
628 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A WARM FRONT ACROSS SOUTHERN NEW YORK WILL SLOWLY LIFT NORTHWARD
THROUGH THE WEEKEND...AS A MATURE LOW PRESSURE SYSTEM MOVES EAST
FROM THE NORTH-CENTRAL PLAINS THROUGH THE MIDWEST/OHIO VALLEY.
THE TRAILING COLD FRONT WILL SLOW ITS EASTWARD PROGRESS AS IT
CROSSES THE APPALACHIANS...INTERACTING WITH THE REMNANTS OF
TROPICAL STORM KAREN. THE DEEP CLOSED UPPER LOW MOVING THROUGH
THE OHIO VALLEY WILL DRAW ABUNDANT MOISTURE NORTHWARD ALONG THE
NORTH-SOUTH COLD FRONT AND LIKELY PRODUCE GENEROUS RAINFALL
AMOUNTS ACROSS CENTRAL PENNSYLVANIA MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
18Z RADAR LOOP SHOWS ISOLD-SCT CONVECTION DEVELOPING ACRS WRN AND
CNTRL PA. LG SCALE FORCING IS FAIRLY NEBULOUS AS THE AREA IS
STILL LARGELY UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE CENTERED
OVER THE SE STATES. DEWPOINTS IN THE 60S AND UNSEASONABLY WARM
AFTN TEMPS IN THE MID 70S-80S IS RESULTING IN SUFFICIENT
INSTABILITY WITH RUC ML CAPES BTWN 500-1000 J/KG. SHORTWAVES
LIFTING NEWD FROM THE OH VLY MAY ALLOW FOR SOME MORE ORGANIZED
CLUSTERS OF STORMS OVER NW PA. SFC WARM FRONT DRAPED NEAR THE PA/NY
BORDER MAY PROVIDE SOME FOCUS BUT OVERALL EXPECT SOMEWHAT
DISORGANIZED CVRG TO CONVECTIVE ACTIVITY. ADDNL SHORTWAVE ENERGY
CRESTING THE UPPER RIDGE MAY CONTINUE TO PRODUCE SCT SHOWERS INTO
TONIGHT...MAINLY OVER THE NRN TIER ZONES INVOF THE WARM FRONTAL
ZONE. HOWEVER INSTABILITY SHOULD DECREASE AFTER DARK SO CVRG MAY
BE LIMITED. EXPECT LOWS TO AGAIN BE VERY MILD/MUGGY FOR THIS TIME
OF YEAR...HOLDING IN THE 60S OVERNIGHT IN MOST PLACES. AREAS OF
FOG AND LOW STRATUS SHOULD DEVELOP AND PERSIST INTO EARLY SUNDAY
MORNING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
CONSENSUS SHORT-RANGE DATA CONTINUES TO FAVOR THE NRN ZONES WITH
THE HIGHEST POPS DURING THE DAY ON SUNDAY...NEAR THE WAVY
Q-STNRY/WARM FRONTAL BOUNDARY. A LIGHT LLVL NELY AGEO WIND/ESE SFC
WIND MAY KEEP CLOUDS ENTRENCHED OVER THE NERN 1/2 TO 1/3 OF THE
CWA THRU THE A.M. HOURS IN SOMEWHAT OF A CAD SFC PATTERN. AN
INCREASING SLY GRADIENT FLOW SHOULD PUSH THE BOUNDARY /AND ASSOCD
LOWER CLOUDS/ NWD DURING THE AFTN. THIS MAKES FOR A TRICKY TEMP
FCST WITH POTENTIAL FOR READINGS TO SOAR WELL INTO THE 80S
/PERHAPS 90F NEAR THE MD LINE/ IN THE WARM SECTOR. PLAYED THE
MIDDLE GROUND FOR NOW USING A CONS MODEL BLEND...IN AN ATTEMPT TO
MITIGATE A POTENTIALLY LARGE MAX T BUST.
SUN NGT FOCUS WILL SHIFT TO DEEP CYCLONE CROSSING THE MIDWEST
STATES AND ITS ASSOCD COLD FRONT. GUIDANCE CONTINUES TO DISPLAY
SOME VARIABILITY WITH THE CLOSED H5 LOW...OWING TO SOME DEGREE OF
INFLUENCE TIED TO A SHORTWAVE IN CENTRAL CANADA BRUSHING ACROSS
THE TOP OF THE MATURE CYCLONE. SPACING BTWN THE TWO SYSTEMS FAVORS
A CONS APPROACH BETWEEN THE NON-NCEP SOLUTIONS LIKE THE 00Z ECMWF
WHICH QUICKLY PHASE THE ENERGY...AND THEIR RESPECTIVE NCEP
COUNTERPARTS WHICH MAINTAIN A CLOSED CYCLONE FOR A LONGER
DURATION. THESE MODEL DIFFS LEAD TO TIMING/PLACEMENT DIFFS WITH
THE COLD FRONT AND QPF AXIS...AS REMNANT TROPICAL MSTR IS DRAWN
NWD ALONG THE N-S FRONTAL ZONE. BY 12Z MON...THE GFS/EC AND HPC
SEEM TO AGREE ON A QPF AXIS CENTERED ALONG THE PA/OH BORDER. THE
MAIN RAIN EVENT FOR CENTRAL PA LOOKS TO BE DURING THE DAY MONDAY
INTO MONDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
CURRENT 12Z RUNS STAY CONSISTENT IN TIMING THROUGH 06Z MONDAY.
AFTER THAT PERIOD THE MODELS BEGIN TO DIVERGE IN TIMING...POSITION
AND INTENSIFICATION. THE LATEST NAM SEEMS TO BE THE SLOWEST
SOLUTION AND STALLS THE LARGE UPPER LEVEL LOWS PROGRESSION...WITH
PASSAGE THROUGH PA EARLY TUESDAY. THE CANADIAN...EC AND GFS MOVE
THE SYSTEM THROUGH 6 TO 12 HOURS FASTER. THE EC MOVES THE
STRONGEST FORCING TO THE NORTH...AND POSITIVELY TILTS THE TROUGH
AS MOVES EASTWARD. THE GFS AND CMC DEEPEN THE TROUGH AS SUCH MADE
A TIMING CHANGE TO THE PASSAGE OF THE FRONT...DELAYING IT BY 6-12
HRS...IN LINE WITH THE TREND IN THE MDLS OVER THE LAST 24 HRS.
THIS ALSO PREDICATED A NUDGE UPWARD IN THE MAXES FOR MONDAY. A
CONSENSUS OF MDL PROG QPF THROUGH THE RAINY PERIOD YIELDS 1 TO 2
INCH AMOUNTS OVER MUCH OF THE AREA...WITH THE HIGHEST AMOUNTS IN
THE LOWER SUSQ VALLEY. THIS SEEMS REASONABLE WITH THE MERGING OF
MOISTURE FROM KAREN AND THE COLD FRONT. THE RECENT LACK OF
RAINFALL SHOULD ALLOW ALL THAT TO BE HANDLED EASILY.
HOWEVER...TROPICAL MOISTURE CAN PILE UP QUICKLY AND UNDER-
ESTIMATION IS POSSIBLE AT THIS RANGE. AS THE FRONT MOVES OVER THE
MOUNTAINS LATE MORNING ON MONDAY...THERE IS A GOOD CHANCE FOR
SCATTERED THUNDERSTORMS ALONG THE BOUNDARY. ALSO EXPECT PERIODS OF
HEAVY RAINFALL AT AND BEHIND THE FRONT...MONDAY AFTERNOON AND
EARLY EVENING.
SPC HAS REMOVED THE SLIGHT RISK...THOUGH WITH THE HEAVY RAINFALL AND
CONVECTION...WHICH SHOULD BE LOW TOPPED...CANNOT RULE OUT GUSTY WINDS
ALONG THE FRONT.
AFTER THE RAIN EXITS THE REGION BY TUESDAY MORNING...A RETURN TO
RIDGING FOR THE MIDDLE AND END OF THE WEEK WITH DRY AND CONTINUED
MILD CONDITIONS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDS WITH LIGHT/VARIABLE WIND WILL CONTINUE THIS
EVENING...THOUGH ISOLATED SHOWERS DRIFTING EAST ACROSS THE REGION
COULD BRING A BRIEF BOUT OF MVFR CONDITIONS. WILL CONTINUE WITH THE
MENTION OF VCSH AT MOST TAF SITES THROUGH 03Z-04Z...AND EVEN A TEMPO
FOR HIGH END IFR CONDITIONS AT KJST BETWEEN 00-02Z...AS A CLUSTER OF
TSRA /CURRENTLY INVOF KPIT/ TRACKS EWD AT 20-25KTS.
CONVECTION WILL WANE DURING THE LATE EVENING WITH THE LOSS OF
HEATING AND LACK OF ANY SIGNIFICANT LLVL BOUNDARY.
CLEARING SKIES...A CALM WIND AND PLENTY OF LOW LVL MOISTURE WILL SET
THE STAGE FOR REDEVELOPMENT OF FOG AND LOW STRATUS LATER TONIGHT.
EXPECT MVFR TO IFR /LOCAL LIFR/ RESTRICTIONS TO PERSIST INTO SUNDAY
MORNING. LOW CLOUDS COULD LINGER OVER THE ERN TERMINALS THRU SUNDAY
MORNING...AS WARM FRONT PIVOTS OVER ZNY SECTOR.
OUTLOOK...
MON...RAIN/LOW CIGS POSSIBLE.
TUE...AM RAIN/LOW CIGS POSSIBLE EAST.
WED-THR...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DANGELO/CERU
AVIATION...LAMBERT/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
405 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A WARM FRONT ACROSS SOUTHERN NEW YORK WILL SLOWLY LIFT NORTHWARD
THROUGH THE WEEKEND...AS A MATURE LOW PRESSURE SYSTEM MOVES EAST
FROM THE NORTH-CENTRAL PLAINS THROUGH THE MIDWEST/OHIO VALLEY.
THE TRAILING COLD FRONT WILL SLOW ITS EASTWARD PROGRESS AS IT
CROSSES THE APPALACHIANS...INTERACTING WITH THE REMNANTS OF
TROPICAL STORM KAREN. THE DEEP CLOSED UPPER LOW MOVING THROUGH
THE OHIO VALLEY WILL DRAW ABUNDANT MOISTURE NORTHWARD ALONG THE
NORTH-SOUTH COLD FRONT AND LIKELY PRODUCE GENEROUS RAINFALL
AMOUNTS ACROSS CENTRAL PENNSYLVANIA MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
18Z RADAR LOOP SHOWS ISOLD-SCT CONVECTION DEVELOPING ACRS WRN AND
CNTRL PA. LG SCALE FORCING IS FAIRLY NEBULOUS AS THE AREA IS
STILL LARGELY UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE CENTERED
OVER THE SE STATES. DEWPOINTS IN THE 60S AND UNSEASONABLY WARM
AFTN TEMPS IN THE MID 70S-80S IS RESULTING IN SUFFICIENT
INSTABILITY WITH RUC ML CAPES BTWN 500-1000 J/KG. SHORTWAVES
LIFTING NEWD FROM THE OH VLY MAY ALLOW FOR SOME MORE ORGANIZED
CLUSTERS OF STORMS OVER NW PA. SFC WARM FRONT DRAPED NEAR THE PA/NY
BORDER MAY PROVIDE SOME FOCUS BUT OVERALL EXPECT SOMEWHAT
DISORGANIZED CVRG TO CONVECTIVE ACTIVITY. ADDNL SHORTWAVE ENERGY
CRESTING THE UPPER RIDGE MAY CONTINUE TO PRODUCE SCT SHOWERS INTO
TONIGHT...MAINLY OVER THE NRN TIER ZONES INVOF THE WARM FRONTAL
ZONE. HOWEVER INSTABILITY SHOULD DECREASE AFTER DARK SO CVRG MAY
BE LIMITED. EXPECT LOWS TO AGAIN BE VERY MILD/MUGGY FOR THIS TIME
OF YEAR...HOLDING IN THE 60S OVERNIGHT IN MOST PLACES. AREAS OF
FOG AND LOW STRATUS SHOULD DEVELOP AND PERSIST INTO EARLY SUNDAY
MORNING.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
CONSENSUS SHORT-RANGE DATA CONTINUES TO FAVOR THE NRN ZONES WITH
THE HIGHEST POPS DURING THE DAY ON SUNDAY...NEAR THE WAVY
Q-STNRY/WARM FRONTAL BOUNDARY. A LIGHT LLVL NELY AGEO WIND/ESE SFC
WIND MAY KEEP CLOUDS ENTRENCHED OVER THE NERN 1/2 TO 1/3 OF THE
CWA THRU THE A.M. HOURS IN SOMEWHAT OF A CAD SFC PATTERN. AN
INCREASING SLY GRADIENT FLOW SHOULD PUSH THE BOUNDARY /AND ASSOCD
LOWER CLOUDS/ NWD DURING THE AFTN. THIS MAKES FOR A TRICKY TEMP
FCST WITH POTENTIAL FOR READINGS TO SOAR WELL INTO THE 80S
/PERHAPS 90F NEAR THE MD LINE/ IN THE WARM SECTOR. PLAYED THE
MIDDLE GROUND FOR NOW USING A CONS MODEL BLEND...IN AN ATTEMPT TO
MITIGATE A POTENTIALLY LARGE MAX T BUST.
SUN NGT FOCUS WILL SHIFT TO DEEP CYCLONE CROSSING THE MIDWEST
STATES AND ITS ASSOCD COLD FRONT. GUIDANCE CONTINUES TO DISPLAY
SOME VARIABILITY WITH THE CLOSED H5 LOW...OWING TO SOME DEGREE OF
INFLUENCE TIED TO A SHORTWAVE IN CENTRAL CANADA BRUSHING ACROSS
THE TOP OF THE MATURE CYCLONE. SPACING BTWN THE TWO SYSTEMS FAVORS
A CONS APPROACH BETWEEN THE NON-NCEP SOLUTIONS LIKE THE 00Z ECMWF
WHICH QUICKLY PHASE THE ENERGY...AND THEIR RESPECTIVE NCEP
COUNTERPARTS WHICH MAINTAIN A CLOSED CYCLONE FOR A LONGER
DURATION. THESE MODEL DIFFS LEAD TO TIMING/PLACEMENT DIFFS WITH
THE COLD FRONT AND QPF AXIS...AS REMNANT TROPICAL MSTR IS DRAWN
NWD ALONG THE N-S FRONTAL ZONE. BY 12Z MON...THE GFS/EC AND HPC
SEEM TO AGREE ON A QPF AXIS CENTERED ALONG THE PA/OH BORDER. THE
MAIN RAIN EVENT FOR CENTRAL PA LOOKS TO BE DURING THE DAY MONDAY
INTO MONDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
CURRENT 12Z RUNS STAY CONSISTENT IN TIMING THROUGH 06Z MONDAY.
AFTER THAT PERIOD THE MODELS BEGIN TO DIVERGE IN TIMING...POSITION
AND INTESIFICATION. THE LATEST NAM SEEMS TO BE THE SLOWEST
SOLUTION AND STALLS THE LARGE UPPER LEVEL LOWS PROGRESSION...WITH
PASSAGE THROUGH PA EARLY TUESDAY. THE CANADIAN...EC AND GFS MOVE
THE SYSTEM THROUGH 6 TO 12 HOURS FASTER. THE EC MOVES THE
STRONGEST FORCING TO THE NORTH...AND POSITIVELY TILTS THE TROUGH
AS MOVES EASTWARD. THE GFS AND CMC DEEPEN THE TROUGH AS SUCH MADE
A TIMING CHANGE TO THE PASSAGE OF THE FRONT...DELAYING IT BY 6-12
HRS...IN LINE WITH THE TREND IN THE MDLS OVER THE LAST 24 HRS.
THIS ALSO PREDICATED A NUDGE UPWARD IN THE MAXES FOR MONDAY. A
CONSENSUS OF MDL PROG QPF THROUGH THE RAINY PERIOD YIELDS 1 TO 2
INCH AMOUNTS OVER MUCH OF THE AREA...WITH THE HIGHEST AMOUNTS IN
THE LOWER SUSQ VALLEY. THIS SEEMS REASONABLE WITH THE MERGING OF
MOISTURE FROM KAREN AND THE COLD FRONT. THE RECENT LACK OF
RAINFALL SHOULD ALLOW ALL THAT TO BE HANDLED EASILY.
HOWEVER...TROPICAL MOISTURE CAN PILE UP QUICKLY AND UNDER-
ESTIMATION IS POSSIBLE AT THIS RANGE. AS THE FRONT MOVES OVER THE
MOUNTAINS LATE MORNING ON MONDAY...THERE IS A GOOD CHANCE FOR
SCATTERED THUNDERSTORMS ALONG THE BOUNDARY. ALSO EXPECT PERIODS OF
HEAVY RAINFALL AT AND BEHIND THE FRONT...MONDAY AFTERNOON AND
EARLY EVENING.
SPC HAS REMOVED THE SLIGHT RISK...THOUGH WITH THE HEAVY RAINFALL
AND CONVECTION...WHICH SHOULD BE LOW TOPPED...CANNOT RULE OUT GUSTY WINDS
ALONG THE FRONT.
AFTER THE RAIN EXITS THE REGION BY TUESDAY MORNING...A RETURN TO
RIDGING FOR THE MIDDLE AND END OF THE WEEK WITH DRY AND CONTINUED
MILD CONDITIONS.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR CONDS CONTINUE THIS AFTN WITH SCT-BKN 3-5KFT MOD CUMULUS BASES
AND ISOLD/WDLY SCT CONVECTION DEVELOPING ACROSS THE AIRSPACE. BRIEF
RESTRICTIONS TO MVFR/IFR ARE POSSIBLE UNDER DIRECT HITS FROM
SHOWERS AND TSTMS. ADDED SOME VCSH MENTION BUT OVERALL CVRG IS
LIMITED. AMDS WILL NEED TO BE ISSUED FOR BRIEF SHRA/TSRA IMPACTS.
CONVECTION SHOULD WANE INTO THE EVE WITH THE LOSS OF INSTABILITY.
CLEARING SKIES...A CALM WIND AND PLENTY OF LOW LVL MOISTURE WILL
SET THE STAGE FOR REDEVELOPMENT OF FOG AND LOW STRATUS TONIGHT.
EXPECT MVFR TO IFR /LOCAL LIFR/ RESTRICTIONS TO PERSIST INTO
SUNDAY MORNING. LOW CLOUDS COULD LINGER OVER THE ERN TERMINALS
THRU SUNDAY MORNING...AS WARM FRONT PIVOTS OVER ZNY SECTOR.
OUTLOOK...
MON...RAIN/LOW CIGS POSSIBLE.
TUE...AM RAIN/LOW CIGS POSSIBLE EAST.
WED-THR...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DANGELO/CERU
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
258 PM EDT SAT OCT 5 2013
.SYNOPSIS...
A WARM FRONT ACROSS SOUTHERN NEW YORK WILL SLOWLY LIFT NORTHWARD
THROUGH THE WEEKEND...AS A MATURE LOW PRESSURE SYSTEM MOVES EAST
FROM THE NORTH-CENTRAL PLAINS THROUGH THE MIDWEST/OHIO VALLEY.
THE TRAILING COLD FRONT WILL SLOW ITS EASTWARD PROGRESS AS IT
CROSSES THE APPALACHIANS...INTERACTING WITH THE REMNANTS OF
TROPICAL STORM KAREN. THE DEEP CLOSED UPPER LOW MOVING THROUGH
THE OHIO VALLEY WILL DRAW ABUNDANT MOISTURE NORTHWARD ALONG THE
NORTH-SOUTH COLD FRONT AND LIKELY PRODUCE GENEROUS RAINFALL
AMOUNTS ACROSS CENTRAL PENNSYLVANIA MONDAY INTO TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z RADAR LOOP SHOWS ISOLD-SCT CONVECTION DEVELOPING ACRS WRN AND
CNTRL PA. LG SCALE FORCING IS FAIRLY NEBULOUS AS THE AREA IS
STILL LARGELY UNDER THE INFLUENCE OF AN UPPER LEVEL RIDGE CENTERED
OVER THE SE STATES. DEWPOINTS IN THE 60S AND UNSEASONABLY WARM
AFTN TEMPS IN THE MID 70S-80S IS RESULTING IN SUFFICIENT
INSTABILITY WITH RUC ML CAPES BTWN 500-1000 J/KG. SHORTWAVES
LIFTING NEWD FROM THE OH VLY MAY ALLOW FOR SOME MORE ORGANIZED
CLUSTERS OF STORMS OVER NW PA. SFC WARM FRONT DRAPED NEAR THE PA/NY
BORDER MAY PROVIDE SOME FOCUS BUT OVERALL EXPECT SOMEWHAT
DISORGANIZED CVRG TO CONVECTIVE ACTIVITY. ADDNL SHORTWAVE ENERGY
CRESTING THE UPPER RIDGE MAY CONTINUE TO PRODUCE SCT SHOWERS INTO
TONIGHT...MAINLY OVER THE NRN TIER ZONES INVOF THE WARM FRONTAL
ZONE. HOWEVER INSTABILITY SHOULD DECREASE AFTER DARK SO CVRG MAY
BE LIMITED. EXPECT LOWS TO AGAIN BE VERY MILD/MUGGY FOR THIS TIME
OF YEAR...HOLDING IN THE 60S OVERNIGHT IN MOST PLACES. AREAS OF
FOG AND LOW STRATUS SHOULD DEVELOP AND PERSIST INTO EARLY SUNDAY
MORNING.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
CONSENSUS SHORT-RANGE DATA CONTINUES TO FAVOR THE NRN ZONES WITH
THE HIGHEST POPS DURING THE DAY ON SUNDAY...NEAR THE WAVY
Q-STNRY/WARM FRONTAL BOUNDARY. A LIGHT LLVL NELY AGEO WIND/ESE SFC
WIND MAY KEEP CLOUDS ENTRENCHED OVER THE NERN 1/2 TO 1/3 OF THE
CWA THRU THE A.M. HOURS IN SOMEWHAT OF A CAD SFC PATTERN. AN
INCREASING SLY GRADIENT FLOW SHOULD PUSH THE BOUNDARY /AND ASSOCD
LOWER CLOUDS/ NWD DURING THE AFTN. THIS MAKES FOR A TRICKY TEMP
FCST WITH POTENTIAL FOR READINGS TO SOAR WELL INTO THE 80S
/PERHAPS 90F NEAR THE MD LINE/ IN THE WARM SECTOR. PLAYED THE
MIDDLE GROUND FOR NOW USING A CONS MODEL BLEND...IN AN ATTEMPT TO
MITIGATE A POTENTIALLY LARGE MAX T BUST.
SUN NGT FOCUS WILL SHIFT TO DEEP CYCLONE CROSSING THE MIDWEST
STATES AND ITS ASSOCD COLD FRONT. GUIDANCE CONTINUES TO DISPLAY
SOME VARIABILITY WITH THE CLOSED H5 LOW...OWING TO SOME DEGREE OF
INFLUENCE TIED TO A SHORTWAVE IN CENTRAL CANADA BRUSHING ACROSS
THE TOP OF THE MATURE CYCLONE. SPACING BTWN THE TWO SYSTEMS FAVORS
A CONS APPROACH BETWEEN THE NON-NCEP SOLUTIONS LIKE THE 00Z ECMWF
WHICH QUICKLY PHASE THE ENERGY...AND THEIR RESPECTIVE NCEP
COUNTERPARTS WHICH MAINTAIN A CLOSED CYCLONE FOR A LONGER
DURATION. THESE MODEL DIFFS LEAD TO TIMING/PLACEMENT DIFFS WITH
THE COLD FRONT AND QPF AXIS...AS REMNANT TROPICAL MSTR IS DRAWN
NWD ALONG THE N-S FRONTAL ZONE. BY 12Z MON...THE GFS/EC AND HPC
SEEM TO AGREE ON A QPF AXIS CENTERED ALONG THE PA/OH BORDER. THE
MAIN RAIN EVENT FOR CENTRAL PA LOOKS TO BE DURING THE DAY MONDAY
INTO MONDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
MADE A TIMING TWEAK TO THE PASSAGE OF THE FRONT...DELAYING IT BY
6-12 HRS...IN LINE WITH THE TREND IN THE MDLS OVER THE LAST 24
HRS. THIS ALSO PREDICATED A NUDGE UPWARD IN THE MAXES FOR MONDAY.
A CONSENSUS OF MDL PROG QPF THROUGH THE RAINY PERIOD YIELDS 1 TO 2
INCH AMOUNTS OVER MUCH OF THE AREA. THIS SEEMS REASONABLE WITH THE
MERGING OF MOISTURE FROM KAREN AND THE COLD FRONT. THE RECENT LACK
OF RAINFALL SHOULD ALLOW ALL THAT TO BE HANDLED EASILY.
HOWEVER...TROPICAL MOISTURE CAN PILE UP QUICKLY AND UNDER-
ESTIMATION IS POSSIBLE AT THIS RANGE.
PREV DISC FOLLOWS...
MAIN FEATURE FOR THE LONG TERM WILL BE A CLOSED UPPER LOW THAT
SLOWLY MOVES FROM THE LOWER OHIO VALLEY TO THE ST. LAWRENCE VALLEY
BY EARLY WEEK. THIS FEATURE WILL HELP DRAW SOME OF THE MOISTURE
ASSOCIATED WITH TROPICAL STORM/DEPRESSION KAREN INTO THE AREA.
WHILE NOT A DIRECT HIT OVER THE REGION...EXPECT STORM TOTAL
AMOUNTS FROM LATE SUNDAY THROUGH TUESDAY TO BE IN THE 1 TO 1.5
INCH RANGE.
LATEST MODELS DELAY THE ARRIVAL OF THE LEADING AREA OF
PRECIPITATION/FRONTAL BOUNDARY TOWARD SUNDAY NIGHT. HAVE BACKED
OFF POPS FOR SUNDAY AFTERNOON AS A RESULT. THIS WILL KEEP MILD AIR
ACROSS THE REGION THROUGH THE WEEKEND.
AFTER THE RAIN EXITS THE REGION BY TUESDAY MORNING...A RETURN TO
RIDGING FOR THE MIDDLE AND END OF THE WEEK WITH DRY AND CONTINUED
MILD CONDITIONS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDS CONTINUE THIS AFTN WITH SCT-BKN 3-5KFT MOD CUMULUS BASES
AND ISOLD/WDLY SCT CONVECTION DEVELOPING ACROSS THE AIRSPACE. BRIEF
RESTRICTIONS TO MVFR/IFR ARE POSSIBLE UNDER DIRECT HITS FROM
SHOWERS AND TSTMS. ADDED SOME VCSH MENTION BUT OVERALL CVRG IS
LIMITED. AMDS WILL NEED TO BE ISSUED FOR BRIEF SHRA/TSRA IMPACTS.
CONVECTION SHOULD WANE INTO THE EVE WITH THE LOSS OF INSTABILITY.
CLEARING SKIES...A CALM WIND AND PLENTY OF LOW LVL MOISTURE WILL
SET THE STAGE FOR REDEVELOPMENT OF FOG AND LOW STRATUS TONIGHT.
EXPECT MVFR TO IFR /LOCAL LIFR/ RESTRICTIONS TO PERSIST INTO
SUNDAY MORNING. LOW CLOUDS COULD LINGER OVER THE ERN TERMINALS
THRU SUNDAY MORNING...AS WARM FRONT PIVOTS OVER ZNY SECTOR.
OUTLOOK...
MON...RAIN/LOW CIGS POSSIBLE.
TUE...AM RAIN/LOW CIGS POSSIBLE EAST.
WED-THR...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DANGELO/TYBURSKI
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
305 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 AGRESSIVE 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 301 PM MDT SAT OCT 5 2013
FOR 12Z TAF ISSUANCE.
A WIDESPREAD AREA OF SNOW CONTINUES TO BLANKET THE AREA...AND VERY
STRONG NORTHWEST WINDS ARE PERSISTING. LIFR AND IFR CONDITIONS WILL
PREDOMINATE OVER WESTERN SD IN SNOW AND BLOWING SNOW THROUGH MID
MORNING SATURDAY. PRECIPITATION WILL END FROM THE WEST WITH IMPROVING
CEILINGS AND VISIBILITIES. BY SUNSET...EXPECT MOSTLY VFR CONDITIONS.
STRONG WINDS WILL DIMINISH VERY SLOWLY DURING THE AFTERNOON SATURDAY.
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 NASHVILLE TN
721 PM CDT SUN OCT 6 2013
.UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE THE
THROUGH LATE AFTERNOON WORDING AND TO TAILOR SHWRS PRESENTLY
MAINLY E OF I-65 TO CONTINUE SLOWING MOVING EWD OUT OF MID STATE
WITH SHWRS CONTINUING ACROSS THE PLATEAU COUNTIES ONLY GENERALLY
AFTER MIDNIGHT. HAVE TAILORED SKY CONDITIONS ALSO TO REFLECT
DECREASING CLOUDINESS W TO E ACROSS THE MID STATE AS THE NIGHT
TIME HRS PROGRESS. CURRENT TEMPS IN LINE WITH FORECASTED LOW
VALUES AS OF THIS TIME...THUS NO ADJUSTMENTS MADE TO OVERNIGHT
LOW VALUES AS OF THIS TIME.
&&
.PREV DISCUSSION.../ISSUED 638 PM CDT SUN OCT 6 2013/
UPDATE...FOR AVIATION.
AVIATION...
00Z TAFS...SHRA HAVE ENDED AT CKV...AND ABOUT TO END FOR BNA.
SHRA AND COLD FRONT NOW APPROACHING CSV.
FOR BNA AND CKV...MAINLY VFR CONDITIONS THROUGH THE NEXT 24 HOURS
WITH DRIER AIR AND HIGH PRESSURE. SOME DAYBREAK MVFR FOG IS
POSSIBLE. AFTER 15Z...LOOK FOR EXCELLENT VSBY...FEW-SCT FAIR WX CU
AND NNW WINDS NEAR 10KT.
CSV WILL BEGIN WITH SEVERAL HOURS OF VARYING MVFR/IFR CONDITIONS
WITH SHRA AND PERHAPS A BRIEF TSRA. RAIN IS EXPECTED TO MOVE OUT
BY 06Z...BUT SOME MVFR CIGS/VSBYS MAY PERSIST THROUGH THE NIGHT.
DAYTIME MONDAY WILL BRING EXCELLENT VSBY...SCT CU AND NW WINDS
NEAR 10KT.
13
PREV DISCUSSION... /ISSUED 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.
31
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.
ROSE
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
638 PM CDT SUN OCT 6 2013
.UPDATE...FOR AVIATION.
&&
.AVIATION...
00Z TAFS...SHRA HAVE ENDED AT CKV...AND ABOUT TO END FOR BNA.
SHRA AND COLD FRONT NOW APPROACHING CSV.
FOR BNA AND CKV...MAINLY VFR CONDITIONS THROUGH THE NEXT 24 HOURS
WITH DRIER AIR AND HIGH PRESSURE. SOME DAYBREAK MVFR FOG IS
POSSIBLE. AFTER 15Z...LOOK FOR EXCELLENT VSBY...FEW-SCT FAIR WX CU
AND NNW WINDS NEAR 10KT.
CSV WILL BEGIN WITH SEVERAL HOURS OF VARYING MVFR/IFR CONDITIONS
WITH SHRA AND PERHAPS A BRIEF TSRA. RAIN IS EXPECTED TO MOVE OUT
BY 06Z...BUT SOME MVFR CIGS/VSBYS MAY PERSIST THROUGH THE NIGHT.
DAYTIME MONDAY WILL BRING EXCELLENT VSBY...SCT CU AND NW WINDS
NEAR 10KT.
13
&&
.PREV DISCUSSION... /ISSUED 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.
31
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.
ROSE
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1154 AM CDT SAT OCT 5 2013
.AVIATION...
BASED ON CURRENT MVMT...FRONT SHOULD BE NEAR CLL AROUND 21Z...IAH
2Z & GLS 5Z. MODELS SHOWING SOME SPOTTY SHRA GENERALLY E OF HWY
288 & I-45 THRU THE DAY AND KEPT VCSHS IN TAFS. DID LOWER CIGS
OVERNIGHT IN THE WAKE OF THE FRONT INTO MVFR & HIGH IFR TERRITORY
AS SOME MOISTURE GETS TRAPPED BELOW SHARP INVERSION. WILL ALSO BE
KEEPING AN EYE ON THE POTENTIAL FOR SOME POST FRONTAL PRECIP
(WITH H85 FRONT LOOKING TO BE FOCUS) OVERNIGHT. MAJORITY OF MODELS
THAT DO SHOW THIS OCCURRING KEEP IT MOSTLY WEST AND EAST OF OUR
TERMINALS. WILL LEAVE MENTION OUT OF 18Z TAFS ATTM AND SEE HOW IT
PLAYS OUT. LOOK CIGS TO LIFT & CLEAR OUT FROM NW-SE FROM MID
MORNING THRU MID/LATE AFTN SUNDAY. 47
&&
.PREV DISCUSSION... /ISSUED 1021 AM CDT SAT OCT 5 2013/
THE COLD FRONT WAS PROGRESSING STEADILY ACROSS THE NORTHERN AND
CENTRAL PORTIONS OF THE STATE. UPDATED THE WIND SHIFT WITH THE
LATEST RAP FORECAST. A 12Z ANALYSIS SHOWED A SURFACE RIDGE OVER
THE TEXAS COASTAL AREAS WITH LOW-LEVEL MOISTURE STREAMING
NORTHWARD FROM THE GULF INTO AREAS MAINLY EAST OF FREEPORT. OVER
MOST OF THE FORECAST AREA THE AIR MASS WAS FAIRLY DRY AND CAPPED
AND EXPECT THAT MOST CONVECTION THIS AFTERNOON WILL BE CONFINED TO
THE EASTERN AND NORTHERN SET OF COUNTIES WHERE THE DEEPER MOISTURE
AND COOLER AIRMASS ALOFT RESIDES.
WILL UPDATE MAINLY FOR THE WINDS. OTHERWISE...THE REMAINDER OF THE
FORECAST LOOKS ON TARGET. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 89 58 81 52 83 / 20 20 10 0 0
HOUSTON (IAH) 92 62 80 53 83 / 50 30 10 0 0
GALVESTON (GLS) 89 69 81 65 80 / 40 30 20 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 PM CDT THIS EVENING
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1021 AM CDT SAT OCT 5 2013
.DISCUSSION...
THE COLD FRONT WAS PROGRESSING STEADILY ACROSS THE NORTHERN AND
CENTRAL PORTIONS OF THE STATE. UPDATED THE WIND SHIFT WITH THE
LATEST RAP FORECAST. A 12Z ANALYSIS SHOWED A SURFACE RIDGE OVER
THE TEXAS COASTAL AREAS WITH LOW-LEVEL MOISTURE STREAMING
NORTHWARD FROM THE GULF INTO AREAS MAINLY EAST OF FREEPORT. OVER
MOST OF THE FORECAST AREA THE AIR MASS WAS FAIRLY DRY AND CAPPED
AND EXPECT THAT MOST CONVECTION THIS AFTERNOON WILL BE CONFINED TO
THE EASTERN AND NORTHERN SET OF COUNTIES WHERE THE DEEPER MOISTURE
AND COOLER AIRMASS ALOFT RESIDES.
WILL UPDATE MAINLY FOR THE WINDS. OTHERWISE...THE REMAINDER OF THE
FORECAST LOOKS ON TARGET.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 89 58 81 52 83 / 20 20 10 0 0
HOUSTON (IAH) 92 62 80 53 83 / 50 30 10 0 0
GALVESTON (GLS) 89 69 81 65 80 / 40 30 20 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 7 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 BLACKSBURG VA
100 PM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT. A LOW
PRESSURE SYSTEM TRACKING FROM THE CENTRAL PLAINS TO THE GREAT
LAKES WILL PUSH A STRONG COLD FRONT THROUGH THE AREA ON MONDAY.
THE LOW AND COLD FRONT WILL MOVE OFFSHORE BY TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT SATURDAY...
SHOULD BE A WARM...POTENTIALLY RECORD BREAKING DAY...ESPECIALLY AT
BLACKSBURG/BLUEFIELD (SEE CLIMATE SECTION BELOW)...AS HIGH
PRESSURE RESIDES OVERHEAD. FOG WILL BE LIFTING ACROSS THE
VALLEYS...BUT HAS HELD STRONG IN THE GREENBRIER VALLEY.
TEMPS STARTING TO RUN A COUPLE DEGREES WARMER OUT EAST THAN
CURRENT FORECAST...SO BUMPED UP HIGHS A COUPLE DEGREES...LOOKING
AT UPPER 70S TO LOWER 80S ACROSS THE HIGHER TERRAIN...TO MID TO
UPPER 80S VALLEYS AND POINTS EAST OF THE BLUE RIDGE.
PREVIOUS VALID DISCUSSION...
SURFACE HIGH PRESSURE AND A 500 MB RIDGE WILL REMAIN OVER THE
CENTRAL AND SOUTHERN APPALACHIANS THROUGH TONIGHT. LOCAL WRF AS
WELL AS HRRR AND LATEST RAP GUIDANCE SUGGEST THERE IS STILL A LOW
CHANCE OF SHOWERS THIS AFTERNOON...MAINLY NORTH OF I-64. ASIDE
FROM THE WEST TO SOUTHWEST UPSLOPE WINDS...LITTLE IN THE WAY OF
SHORT WAVES TO HELP TRIGGER ANY PRECIPITATION.
ANY SCATTERED TO BROKEN CU THAT DEVELOPS TODAY WILL DISSIPATE
THIS EVENING. USED A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR
OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 453 AM EDT SATURDAY...
MODELS REMAINING CONSISTENT WITH MOVING A COLD FRONT AND ASSOCIATED
SHOWERS INTO THE OHIO VALLEY ON SUNDAY. MODELS HAVE SLOWED DOWN THE
FRONTS MOVEMENT INTO THE AREA SUNDAY NIGHT AND ACROSS THE REGION
MONDAY/MONDAY NIGHT. THE SLOWER PROGRESSION OF THE FRONT IS DUE TO
UPPER LEVEL FORCING BECOMING DETACHED FROM THE LOW LEVEL BOUNDARY.
TROPICAL STORM KAREN OR REMNANTS OF...MAY ALSO PLAYING A PART IN
SLOWING THE FRONT DOWN TO A CRAWL AS IT CROSSES OVER THE AREA. BASED
ON THE 00Z MODEL TRENDS...LOWERED POPS INTO SUNDAY EVENING.
MEASURABLE RAIN BEGINS TO TRACK ACROSS THE SOUTHWEST EARLY MONDAY
MORNING...THEN SPREADS ACROSS THE REST OF THE MOUNTAINS AROUND
SUNRISE. RAIN CHANCES INCREASE EAST OF THE BLUE RIDGE TOWARD THE
AFTERNOON AND CONTINUES INTO THE EVENING. WITH A COLD FRONT
INTERACTING WITH TROPICAL MOISTURE...IT WAS A NO BRAINER TO INCREASE
POPS TO 100 PERCENT MONDAY. WITH THE FRONT BEING SLOWER...ALSO
INCREASED POPS MONDAY EVENING...TRENDING DOWN TUESDAY MORNING AS THE
FRONT TRACKS EAST.
WITH SHOWERS NOT DUE TO MOVE ACROSS THE PIEDMONT UNTIL THE
AFTERNOON...THERE MAY BE ENOUGH INSTABILITIES TO GENERATE A RUMBLE
OF THUNDER. IF ENOUGH INSTABILITIES IS PRESENT WHEN THE 850 JET
PASSES OVERHEAD...A STORM OR TWO MAY PRODUCE STRONG WINDS. FOR THE
MOST PART...THIS WILL BE A HYDRO EVENT. PWATS ON MONDAY APPROACH 2
INCHES WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL.
RAINFALL AMOUNTS FROM SUNDAY NIGHT INTO MONDAY EVENING SHOULD RANGE
FROM 1 TO 2 INCHES. WITH THE RECENT DRY SPELL...THE FORECAST AREA
SHOULD NOT SEE ANY WIDESPREAD WATER PROBLEMS. LOCALIZE FLOODING IS
NOT OUT OF THE QUESTION IN POOR DRAINAGE AREAS...ESPECIALLY IF HIGH
RAINFALL RATES OR TRAINING OF STORMS PERSIST OVER AN AREA FOR
SEVERAL HOURS.
THE UPPER LEVEL RIDGE THAT BROUGHT WARMTH TO THE AREA ON SATURDAY
WILL BEGIN TO SLIDE OFF THE SOUTHEAST COAST ON SUNDAY. WITH THE
FRONT REMAINING WEST OF THE AREA FOR MOST OF SUNDAY...WARMER THAN
NORMAL TEMPERATURES WILL AGAIN COVER THE REGION. SUNDAY TEMPERATURES
WILL RANGE FROM THE LOW TO MID 80S ACROSS THE WEST TO MID TO UPPER
80S IN THE EAST. A DRAMATIC COOL DOWN COMES MONDAY WITH THE RAIN.
FORECASTED HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN
THE WEST TO LOWER 70S ACROSS THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
FORECAST EARLY IN THE PERIOD CENTERS AROUND THE FRONT/REMNANTS OF
KAREN AND THE UPPER TROUGH MOVING ACROSS THE GREAT
LAKES/NORTHEAST/MID ATLANTIC. THE LATEST GFS (12Z) CONTINUES TO BE
SLOWER...AND IS ACTUALLY SLOWER THAN THE 06Z RUN IN MOVING THE FRONT
OUT...WITH A STRONGER UPPER LOW...BUT IS FURTHER EAST WITH KAREN.
PER NHC/WPC...WILL BE LEANING TOWARD THE 00Z ECMWF AND THE PREVIOUS
FORECAST. THERE WILL STILL BE LINGERING SHOWERS ACROSS THE PIEDMONT
TUESDAY AND NOT OUT OF THE QUESTION THAT STRONG SUBSIDENCE BEHIND
THE DEPARTING TROPICAL SYSTEM MAY START TO DRY THINGS OUT FASTER.
FOR MID TO LATE WEEK...THE FORECAST MAINTAINS A CHALLENGE IN TERMS
OF SFC HIGH PRESSURE WEDGING SOUTH INTO OUR AREA...WHILE A RESIDUAL
UPPER TROUGH LINGERS OVER THE SOUTHEAST. QUESTION WILL BE WHERE
DEEPER MOISTURE RESIDES. WITH THE ECMWF THINK MOST OF THE CLOUD
COVER WILL BE HUGGING OUR SOUTHEAST CWA WITH MORE RESIDING ACROSS
THE SOUTHEAST...WHILE THE WESTERN CWA SEES MORE SUN DURING THE DAY.
TEMPERATURES GIVEN A LIGHT NE-E FLOW WILL BE CLOSER TO NORMAL...WITH
THE THREAT OF RAIN BEING LESS THAN 10 PERCENT.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 100 PM EDT SATURDAY...
AXIS OF UPPER RIDGE WILL CROSS THE AREA AS WE BEGIN TO COME UNDER
THE INFLUENCE OF UPSTREAM SYSTEM APPROACHING FROM THE MIDWEST. THERE
WILL BE A LITTLE SHORT WAVE ENERGY MOVING THROUGH THE ARE EARLY IN
THE TAF PERIOD...BUT SIGNIFICANT MOISTURE IS LACKING AND CAPES ARE
MEAGER. WHILE AN ISOLATED SHOWER CAN NOT BE RULED OUT IT DOES NOT
WARRANT A MENTION IN THE TAFS. WILL GO WITH BKN VFR CIGS WEST AND
NORTH WITH JUST SCT EAST AND SOUTH.
EXPECTING MID/HIGH CLOUDS TO REMAIN MOSTLY TO OUR NORTH AND ALLOW
FOR DECENT RAD COOLING OVERNIGHT. THUS...EXPECTING KLWB/KBCB TO
FOG IN AGAIN TONIGHT BUT ONLY MVFR AT OTHER SITES. SHOULD STAY VFR
AT KBLF AS WINDS COME AROUND TO A SWLY DIRECTION TO PROHIBIT FOG.
.EXTENDED AVIATION...
LOOKS LIKE COLD FRONT APPROACHING FROM THE WEST WILL BE THE MAIN
PLAYER FOR OUR WEATHER SUNDAY NIGHT THROUGH MONDAY AS TROPICAL
SYSTEM REMAINS TO OUR SOUTH. AVIATION CONDITIONS WILL BE QUITE
POOR THIS PERIOD WITH RAIN...GUSTY WINDS...AND LIKELY IFR CONDITIONS.
HOWEVER...THINGS WILL IMPROVE CONSIDERABLY BEHIND THE FRONT
TUESDAY...AND THE REMAINDER OF THE WEEK LOOKS GOOD FOR AVIATION
WITH THE EXPECTATION OF DIURNAL FOG FORMATION.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR SATURDAY.
ROANOKE 98/1941
LYNCHBURG 96/1941
DANVILLE 98/1951
BLACKSBURG 86/1954
BLUEFIELD 85/2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...AMS/WP
SHORT TERM...RCS
LONG TERM...JH/WP
AVIATION...MBS
CLIMATE...RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1017 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT. A LOW
PRESSURE SYSTEM TRACKING FROM THE CENTRAL PLAINS TO THE GREAT
LAKES WILL PUSH A STRONG COLD FRONT THROUGH THE AREA ON MONDAY.
THE LOW AND COLD FRONT WILL MOVE OFFSHORE BY TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT SATURDAY...
SHOULD BE A WARM...POTENTIALLY RECORD BREAKING DAY...ESPECIALLY AT
BLACKSBURG/BLUEFIELD (SEE CLIMATE SECTION BELOW)...AS HIGH
PRESSURE RESIDES OVERHEAD. FOG WILL BE LIFTING ACROSS THE
VALLEYS...BUT HAS HELD STRONG IN THE GREENBRIER VALLEY.
TEMPS STARTING TO RUN A COUPLE DEGREES WARMER OUT EAST THAN
CURRENT FORECAST...SO BUMPED UP HIGHS A COUPLE DEGREES...LOOKING
AT UPPER 70S TO LOWER 80S ACROSS THE HIGHER TERRAIN...TO MID TO
UPPER 80S VALLEYS AND POINTS EAST OF THE BLUE RIDGE.
PREVIOUS VALID DISCUSSION...
SURFACE HIGH PRESSURE AND A 500 MB RIDGE WILL REMAIN OVER THE
CENTRAL AND SOUTHERN APPALACHIANS THROUGH TONIGHT. LOCAL WRF AS
WELL AS HRRR AND LATEST RAP GUIDANCE SUGGEST THERE IS STILL A LOW
CHANCE OF SHOWERS THIS AFTERNOON...MAINLY NORTH OF I-64. ASIDE
FROM THE WEST TO SOUTHWEST UPSLOPE WINDS...LITTLE IN THE WAY OF
SHORT WAVES TO HELP TRIGGER ANY PRECIPITATION.
ANY SCATTERED TO BROKEN CU THAT DEVELOPS TODAY WILL DISSIPATE
THIS EVENING. USED A BLEND OF BIAS CORRECTED MAV/MET GUIDANCE FOR
OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 453 AM EDT SATURDAY...
MODELS REMAINING CONSISTENT WITH MOVING A COLD FRONT AND ASSOCIATED
SHOWERS INTO THE OHIO VALLEY ON SUNDAY. MODELS HAVE SLOWED DOWN THE
FRONTS MOVEMENT INTO THE AREA SUNDAY NIGHT AND ACROSS THE REGION
MONDAY/MONDAY NIGHT. THE SLOWER PROGRESSION OF THE FRONT IS DUE TO
UPPER LEVEL FORCING BECOMING DETACHED FROM THE LOW LEVEL BOUNDARY.
TROPICAL STORM KAREN OR REMNANTS OF...MAY ALSO PLAYING A PART IN
SLOWING THE FRONT DOWN TO A CRAWL AS IT CROSSES OVER THE AREA. BASED
ON THE 00Z MODEL TRENDS...LOWERED POPS INTO SUNDAY EVENING.
MEASURABLE RAIN BEGINS TO TRACK ACROSS THE SOUTHWEST EARLY MONDAY
MORNING...THEN SPREADS ACROSS THE REST OF THE MOUNTAINS AROUND
SUNRISE. RAIN CHANCES INCREASE EAST OF THE BLUE RIDGE TOWARD THE
AFTERNOON AND CONTINUES INTO THE EVENING. WITH A COLD FRONT
INTERACTING WITH TROPICAL MOISTURE...IT WAS A NO BRAINER TO INCREASE
POPS TO 100 PERCENT MONDAY. WITH THE FRONT BEING SLOWER...ALSO
INCREASED POPS MONDAY EVENING...TRENDING DOWN TUESDAY MORNING AS THE
FRONT TRACKS EAST.
WITH SHOWERS NOT DUE TO MOVE ACROSS THE PIEDMONT UNTIL THE
AFTERNOON...THERE MAY BE ENOUGH INSTABILITIES TO GENERATE A RUMBLE
OF THUNDER. IF ENOUGH INSTABILITIES IS PRESENT WHEN THE 850 JET
PASSES OVERHEAD...A STORM OR TWO MAY PRODUCE STRONG WINDS. FOR THE
MOST PART...THIS WILL BE A HYDRO EVENT. PWATS ON MONDAY APPROACH 2
INCHES WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL.
RAINFALL AMOUNTS FROM SUNDAY NIGHT INTO MONDAY EVENING SHOULD RANGE
FROM 1 TO 2 INCHES. WITH THE RECENT DRY SPELL...THE FORECAST AREA
SHOULD NOT SEE ANY WIDESPREAD WATER PROBLEMS. LOCALIZE FLOODING IS
NOT OUT OF THE QUESTION IN POOR DRAINAGE AREAS...ESPECIALLY IF HIGH
RAINFALL RATES OR TRAINING OF STORMS PERSIST OVER AN AREA FOR
SEVERAL HOURS.
THE UPPER LEVEL RIDGE THAT BROUGHT WARMTH TO THE AREA ON SATURDAY
WILL BEGIN TO SLIDE OFF THE SOUTHEAST COAST ON SUNDAY. WITH THE
FRONT REMAINING WEST OF THE AREA FOR MOST OF SUNDAY...WARMER THAN
NORMAL TEMPERATURES WILL AGAIN COVER THE REGION. SUNDAY TEMPERATURES
WILL RANGE FROM THE LOW TO MID 80S ACROSS THE WEST TO MID TO UPPER
80S IN THE EAST. A DRAMATIC COOL DOWN COMES MONDAY WITH THE RAIN.
FORECASTED HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN
THE WEST TO LOWER 70S ACROSS THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
FORECAST EARLY IN THE PERIOD CENTERS AROUND THE FRONT/REMNANTS OF
KAREN AND THE UPPER TROUGH MOVING ACROSS THE GREAT
LAKES/NORTHEAST/MID ATLANTIC. THE LATEST GFS (12Z) CONTINUES TO BE
SLOWER...AND IS ACTUALLY SLOWER THAN THE 06Z RUN IN MOVING THE FRONT
OUT...WITH A STRONGER UPPER LOW...BUT IS FURTHER EAST WITH KAREN.
PER NHC/WPC...WILL BE LEANING TOWARD THE 00Z ECMWF AND THE PREVIOUS
FORECAST. THERE WILL STILL BE LINGERING SHOWERS ACROSS THE PIEDMONT
TUESDAY AND NOT OUT OF THE QUESTION THAT STRONG SUBSIDENCE BEHIND
THE DEPARTING TROPICAL SYSTEM MAY START TO DRY THINGS OUT FASTER.
FOR MID TO LATE WEEK...THE FORECAST MAINTAINS A CHALLENGE IN TERMS
OF SFC HIGH PRESSURE WEDGING SOUTH INTO OUR AREA...WHILE A RESIDUAL
UPPER TROUGH LINGERS OVER THE SOUTHEAST. QUESTION WILL BE WHERE
DEEPER MOISTURE RESIDES. WITH THE ECMWF THINK MOST OF THE CLOUD
COVER WILL BE HUGGING OUR SOUTHEAST CWA WITH MORE RESIDING ACROSS
THE SOUTHEAST...WHILE THE WESTERN CWA SEES MORE SUN DURING THE DAY.
TEMPERATURES GIVEN A LIGHT NE-E FLOW WILL BE CLOSER TO NORMAL...WITH
THE THREAT OF RAIN BEING LESS THAN 10 PERCENT.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 740 AM EDT SATURDAY...
NEW RIVER AND GREENBRIER VALLEYS HAD DENSE FOG THIS MORNING...
INCLUDING LIFR VISIBILITIES AT KBCB AND KLWB. EXPECT IMPROVEMENT IN
CONDITIONS BY 10AM. ONCE FOG MIXES OUT THIS MORNING...HIGH
CONFIDENCE THAT THE REST OF THE DAY WILL BE VFR. HAVE ADDED FOG IN
AGAIN FOR TONIGHT IN KLWB AND KBCB, WITH DEW POINTS GRADUALLY
RISING...THERE IS A POSSIBILITY FOR MVFR FOG AT KDAN AND KLYH
AFTER 06Z2AM TONIGHT.
MID AND HIGH LEVEL CLOUDS WILL ARRIVE SUNDAY THOUGH AS THE COLD
FRONT ENTERS THE OHIO VALLEY. OUR NEXT CHANCE FOR WIDESPREAD AND
PROLONGED SUB-VFR CONDITIONS WILL COME SUNDAY NIGHT INTO MONDAY
WHEN A COLD FRONT APPROACHES FROM THE WEST...AND WHAT IS LEFT OF
TROPICAL CYCLONE KAREN RIDES NORTH THROUGH OR NEAR OUR REGION IN
ADVANCE OF IT. THIS WOULD ALLOW A TREND TOWARD DECREASING CEILING
HEIGHTS AND INCREASED COVERAGE OF RAIN. VISIBILITIES WOULD TREND
LOWER AS WELL...ESPECIALLY SUNDAY INTO MONDAY AS PRECIPITATION
INTENSIFIES AND FOG POTENTIAL INCREASES.
RAIN ENDS MONDAY NIGHT BUT THERE STILL MAY BE RESTRICTIONS IN
CEILING AND VISIBILITY AS PRECIP COULD STILL BE HEAVY ACROSS THE
VA/NC PIEDMONT WITH POTENTIALLY SOME FOG ACROSS SE WEST VA. A
DRIER PATTERN IS EXPECTED TUESDAY AND WEDNESDAY WITH MORNING FOG.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR SATURDAY.
ROANOKE 98/1941
LYNCHBURG 96/1941
DANVILLE 98/1951
BLACKSBURG 86/1954
BLUEFIELD 85/2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...AMS/WP
SHORT TERM...RCS
LONG TERM...JH/WP
AVIATION...AMS/KK/KM
CLIMATE...RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
746 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY AND TONIGHT. A
LOW PRESSURE SYSTEM TRACKING FROM THE CENTRAL PLAINS TO THE GREAT
LAKES WILL PUSH A STRONG COLD FRONT THROUGH THE AREA ON MONDAY.
THE LOW AND COLD FRONT WILL MOVE OFFSHORE BY TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM EDT SATURDAY...
SURFACE HIGH PRESSURE AND A 500 MB RIDGE WILL REMAIN OVER THE
CENTRAL AND SOUTHERN APPALACHIANS TODAY AND TONIGHT. LOCAL WRF AS
WELL AS HRRR AND LATEST RAP GUIDANCE SUGGEST THERE IS STILL A LOW
CHANCE OF SHOWERS THIS AFTERNOON...MAINLY NORTH OF I-64. ASIDE
FROM THE WEST TO SOUTHWEST UPSLOPE WINDS...LITTLE IN THE WAY OF
SHORT WAVES TO HELP TRIGGER ANY PRECIPITATION.
DEEP SOUTHWEST WINDS THIS AFTERNOON...EVEN THOUGH WIND SPEEDS WILL
NOT BE VERY STRONG...WILL PROVIDE SOME DOWNSLOPNIG AND
COMPRESSION. COMBINED WITH 850 MB TEMPERATURES OF +16 TO
+18...MAXIMUM TEMPERATURES WILL AGAIN BE WELL ABOVE NORMAL.
EXPECTING SIMILAR TEMPERATURES COMPARED TO FRIDAY...AND POSSIBLY A
DEGREE OR TWO HIGH AS LONG AS THERE IS NOT CLOUD COVER.
ANY SCATTERED TO BROKEN STRATOCUMULUS THAT DEVELOPS TODAY WILL
DISSIPATE THIS EVENING. USED A BLEND OF BIAS CORRECTED MAV/MET
GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 453 AM EDT SATURDAY...
MODELS REMAINING CONSISTENT WITH MOVING A COLD FRONT AND ASSOCIATED
SHOWERS INTO THE OHIO VALLEY ON SUNDAY. MODELS HAVE SLOWED DOWN THE
FRONTS MOVEMENT INTO THE AREA SUNDAY NIGHT AND ACROSS THE REGION
MONDAY/MONDAY NIGHT. THE SLOWER PROGRESSION OF THE FRONT IS DUE TO
UPPER LEVEL FORCING BECOMING DETACHED FROM THE LOW LEVEL BOUNDARY.
TROPICAL STORM KAREN OR REMNANTS OF...MAY ALSO PLAYING A PART IN
SLOWING THE FRONT DOWN TO A CRAWL AS IT CROSSES OVER THE AREA. BASED
ON THE 00Z MODEL TRENDS...LOWERED POPS INTO SUNDAY EVENING.
MEASURABLE RAIN BEGINS TO TRACK ACROSS THE SOUTHWEST EARLY MONDAY
MORNING...THEN SPREADS ACROSS THE REST OF THE MOUNTAINS AROUND
SUNRISE. RAIN CHANCES INCREASE EAST OF THE BLUE RIDGE TOWARD THE
AFTERNOON AND CONTINUES INTO THE EVENING. WITH A COLD FRONT
INTERACTING WITH TROPICAL MOISTURE...IT WAS A NO BRAINER TO INCREASE
POPS TO 100 PERCENT MONDAY. WITH THE FRONT BEING SLOWER...ALSO
INCREASED POPS MONDAY EVENING...TRENDING DOWN TUESDAY MORNING AS THE
FRONT TRACKS EAST.
WITH SHOWERS NOT DUE TO MOVE ACROSS THE PIEDMONT UNTIL THE
AFTERNOON...THERE MAY BE ENOUGH INSTABILITIES TO GENERATE A RUMBLE
OF THUNDER. IF ENOUGH INSTABILITIES IS PRESENT WHEN THE 850 JET
PASSES OVERHEAD...A STORM OR TWO MAY PRODUCE STRONG WINDS. FOR THE
MOST PART...THIS WILL BE A HYDRO EVENT. PWATS ON MONDAY APPROACH 2
INCHES WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL.
RAINFALL AMOUNTS FROM SUNDAY NIGHT INTO MONDAY EVENING SHOULD RANGE
FROM 1 TO 2 INCHES. WITH THE RECENT DRY SPELL...THE FORECAST AREA
SHOULD NOT SEE ANY WIDESPREAD WATER PROBLEMS. LOCALIZE FLOODING IS
NOT OUT OF THE QUESTION IN POOR DRAINAGE AREAS...ESPECIALLY IF HIGH
RAINFALL RATES OR TRAINING OF STORMS PERSIST OVER AN AREA FOR
SEVERAL HOURS.
THE UPPER LEVEL RIDGE THAT BROUGHT WARMTH TO THE AREA ON SATURDAY
WILL BEGIN TO SLIDE OFF THE SOUTHEAST COAST ON SUNDAY. WITH THE
FRONT REMAINING WEST OF THE AREA FOR MOST OF SUNDAY...WARMER THAN
NORMAL TEMPERATURES WILL AGAIN COVER THE REGION. SUNDAY TEMPERATURES
WILL RANGE FROM THE LOW TO MID 80S ACROSS THE WEST TO MID TO UPPER
80S IN THE EAST. A DRAMATIC COOL DOWN COMES MONDAY WITH THE RAIN.
FORECASTED HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN
THE WEST TO LOWER 70S ACROSS THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
FORECAST EARLY IN THE PERIOD CENTERS AROUND THE FRONT/REMNANTS OF
KAREN AND THE UPPER TROUGH MOVING ACROSS THE GREAT
LAKES/NORTHEAST/MID ATLANTIC. THE LATEST GFS (12Z) CONTINUES TO BE
SLOWER...AND IS ACTUALLY SLOWER THAN THE 06Z RUN IN MOVING THE FRONT
OUT...WITH A STRONGER UPPER LOW...BUT IS FURTHER EAST WITH KAREN.
PER NHC/WPC...WILL BE LEANING TOWARD THE 00Z ECMWF AND THE PREVIOUS
FORECAST. THERE WILL STILL BE LINGERING SHOWERS ACROSS THE PIEDMONT
TUESDAY AND NOT OUT OF THE QUESTION THAT STRONG SUBSIDENCE BEHIND
THE DEPARTING TROPICAL SYSTEM MAY START TO DRY THINGS OUT FASTER.
FOR MID TO LATE WEEK...THE FORECAST MAINTAINS A CHALLENGE IN TERMS
OF SFC HIGH PRESSURE WEDGING SOUTH INTO OUR AREA...WHILE A RESIDUAL
UPPER TROUGH LINGERS OVER THE SOUTHEAST. QUESTION WILL BE WHERE
DEEPER MOISTURE RESIDES. WITH THE ECMWF THINK MOST OF THE CLOUD
COVER WILL BE HUGGING OUR SOUTHEAST CWA WITH MORE RESIDING ACROSS
THE SOUTHEAST...WHILE THE WESTERN CWA SEES MORE SUN DURING THE DAY.
TEMPERATURES GIVEN A LIGHT NE-E FLOW WILL BE CLOSER TO NORMAL...WITH
THE THREAT OF RAIN BEING LESS THAN 10 PERCENT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 740 AM EDT SATURDAY...
NEW RIVER AND GREENBRIER VALLEYS HAD DENSE FOG THIS MORNING...
INCLUDING LIFR VISIBILITIES AT KBCB AND KLWB. EXPECT IMPROVEMENT IN
CONDITIONS BY 10AM. ONCE FOG MIXES OUT THIS MORNING...HIGH
CONFIDENCE THAT THE REST OF THE DAY WILL BE VFR. HAVE ADDED FOG IN
AGAIN FOR TONIGHT IN KLWB AND KBCB, WITH DEW POINTS GRADUALLY
RISING...THERE IS A POSSIBILITY FOR MVFR FOG AT KDAN AND KLYH
AFTER 06Z2AM TONIGHT.
MID AND HIGH LEVEL CLOUDS WILL ARRIVE SUNDAY THOUGH AS THE COLD
FRONT ENTERS THE OHIO VALLEY. OUR NEXT CHANCE FOR WIDESPREAD AND
PROLONGED SUB-VFR CONDITIONS WILL COME SUNDAY NIGHT INTO MONDAY
WHEN A COLD FRONT APPROACHES FROM THE WEST...AND WHAT IS LEFT OF
TROPICAL CYCLONE KAREN RIDES NORTH THROUGH OR NEAR OUR REGION IN
ADVANCE OF IT. THIS WOULD ALLOW A TREND TOWARD DECREASING CEILING
HEIGHTS AND INCREASED COVERAGE OF RAIN. VISIBILITIES WOULD TREND
LOWER AS WELL...ESPECIALLY SUNDAY INTO MONDAY AS PRECIPITATION
INTENSIFIES AND FOG POTENTIAL INCREASES.
RAIN ENDS MONDAY NIGHT BUT THERE STILL MAY BE RESTRICTIONS IN
CEILING AND VISIBILITY AS PRECIP COULD STILL BE HEAVY ACROSS THE
VA/NC PIEDMONT WITH POTENTIALLY SOME FOG ACROSS SE WEST VA. A
DRIER PATTERN IS EXPECTED TUESDAY AND WEDNESDAY WITH MORNING FOG.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR SATURDAY.
ROANOKE 98/1941
LYNCHBURG 96/1941
DANVILLE 98/1951
BLACKSBURG 86/1954
BLUEFIELD 85/2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...JH/WP
AVIATION...AMS/KK/KM
CLIMATE...RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
456 AM EDT SAT OCT 5 2013
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY AND TONIGHT. A
LOW PRESSURE SYSTEM TRACKING FROM THE CENTRAL PLAINS TO THE GREAT
LAKES WILL PUSH A STRONG COLD FRONT THROUGH THE AREA ON MONDAY.
THE LOW AND COLD FRONT WILL MOVE OFFSHORE BY TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM EDT SATURDAY...
SURFACE HIGH PRESSURE AND A 500 MB RIDGE WILL REMAIN OVER THE
CENTRAL AND SOUTHERN APPALACHIANS TODAY AND TONIGHT. LOCAL WRF AS
WELL AS HRRR AND LATEST RAP GUIDANCE SUGGEST THERE IS STILL A LOW
CHANCE OF SHOWERS THIS AFTERNOON...MAINLY NORTH OF I-64. ASIDE
FROM THE WEST TO SOUTHWEST UPSLOPE WINDS...LITTLE IN THE WAY OF
SHORT WAVES TO HELP TRIGGER ANY PRECIPITATION.
DEEP SOUTHWEST WINDS THIS AFTERNOON...EVEN THOUGH WIND SPEEDS WILL
NOT BE VERY STRONG...WILL PROVIDE SOME DOWNSLOPNIG AND
COMPRESSION. COMBINED WITH 850 MB TEMPERATURES OF +16 TO
+18...MAXIMUM TEMPERATURES WILL AGAIN BE WELL ABOVE NORMAL.
EXPECTING SIMILAR TEMPERATURES COMPARED TO FRIDAY...AND POSSIBLY A
DEGREE OR TWO HIGH AS LONG AS THERE IS NOT CLOUD COVER.
ANY SCATTERED TO BROKEN STRATOCUMULUS THAT DEVELOPS TODAY WILL
DISSIPATE THIS EVENING. USED A BLEND OF BIAS CORRECTED MAV/MET
GUIDANCE FOR OVERNIGHT LOWS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 453 AM EDT SATURDAY...
MODELS REMAINING CONSISTENT WITH MOVING A COLD FRONT AND ASSOCIATED
SHOWERS INTO THE OHIO VALLEY ON SUNDAY. MODELS HAVE SLOWED DOWN THE
FRONTS MOVEMENT INTO THE AREA SUNDAY NIGHT AND ACROSS THE REGION
MONDAY/MONDAY NIGHT. THE SLOWER PROGRESSION OF THE FRONT IS DUE TO
UPPER LEVEL FORCING BECOMING DETACHED FROM THE LOW LEVEL BOUNDARY.
TROPICAL STORM KAREN OR REMNANTS OF...MAY ALSO PLAYING A PART IN
SLOWING THE FRONT DOWN TO A CRAWL AS IT CROSSES OVER THE AREA. BASED
ON THE 00Z MODEL TRENDS...LOWERED POPS INTO SUNDAY EVENING.
MEASURABLE RAIN BEGINS TO TRACK ACROSS THE SOUTHWEST EARLY MONDAY
MORNING...THEN SPREADS ACROSS THE REST OF THE MOUNTAINS AROUND
SUNRISE. RAIN CHANCES INCREASE EAST OF THE BLUE RIDGE TOWARD THE
AFTERNOON AND CONTINUES INTO THE EVENING. WITH A COLD FRONT
INTERACTING WITH TROPICAL MOISTURE...IT WAS A NO BRAINER TO INCREASE
POPS TO 100 PERCENT MONDAY. WITH THE FRONT BEING SLOWER...ALSO
INCREASED POPS MONDAY EVENING...TRENDING DOWN TUESDAY MORNING AS THE
FRONT TRACKS EAST.
WITH SHOWERS NOT DUE TO MOVE ACROSS THE PIEDMONT UNTIL THE
AFTERNOON...THERE MAY BE ENOUGH INSTABILITIES TO GENERATE A RUMBLE
OF THUNDER. IF ENOUGH INSTABILITIES IS PRESENT WHEN THE 850 JET
PASSES OVERHEAD...A STORM OR TWO MAY PRODUCE STRONG WINDS. FOR THE
MOST PART...THIS WILL BE A HYDRO EVENT. PWATS ON MONDAY APPROACH 2
INCHES WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL.
RAINFALL AMOUNTS FROM SUNDAY NIGHT INTO MONDAY EVENING SHOULD RANGE
FROM 1 TO 2 INCHES. WITH THE RECENT DRY SPELL...THE FORECAST AREA
SHOULD NOT SEE ANY WIDESPREAD WATER PROBLEMS. LOCALIZE FLOODING IS
NOT OUT OF THE QUESTION IN POOR DRAINAGE AREAS...ESPECIALLY IF HIGH
RAINFALL RATES OR TRAINING OF STORMS PERSIST OVER AN AREA FOR
SEVERAL HOURS.
THE UPPER LEVEL RIDGE THAT BROUGHT WARMTH TO THE AREA ON SATURDAY
WILL BEGIN TO SLIDE OFF THE SOUTHEAST COAST ON SUNDAY. WITH THE
FRONT REMAINING WEST OF THE AREA FOR MOST OF SUNDAY...WARMER THAN
NORMAL TEMPERATURES WILL AGAIN COVER THE REGION. SUNDAY TEMPERATURES
WILL RANGE FROM THE LOW TO MID 80S ACROSS THE WEST TO MID TO UPPER
80S IN THE EAST. A DRAMATIC COOL DOWN COMES MONDAY WITH THE RAIN.
FORECASTED HIGH TEMPERATURES MONDAY WILL RANGE FROM THE MID 60S IN
THE WEST TO LOWER 70S ACROSS THE PIEDMONT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...
FORECAST EARLY IN THE PERIOD CENTERS AROUND THE FRONT/REMNANTS OF
KAREN AND THE UPPER TROUGH MOVING ACROSS THE GREAT
LAKES/NORTHEAST/MID ATLANTIC. THE LATEST GFS (12Z) CONTINUES TO BE
SLOWER...AND IS ACTUALLY SLOWER THAN THE 06Z RUN IN MOVING THE FRONT
OUT...WITH A STRONGER UPPER LOW...BUT IS FURTHER EAST WITH KAREN.
PER NHC/WPC...WILL BE LEANING TOWARD THE 00Z ECMWF AND THE PREVIOUS
FORECAST. THERE WILL STILL BE LINGERING SHOWERS ACROSS THE PIEDMONT
TUESDAY AND NOT OUT OF THE QUESTION THAT STRONG SUBSIDENCE BEHIND
THE DEPARTING TROPICAL SYSTEM MAY START TO DRY THINGS OUT FASTER.
FOR MID TO LATE WEEK...THE FORECAST MAINTAINS A CHALLENGE IN TERMS
OF SFC HIGH PRESSURE WEDGING SOUTH INTO OUR AREA...WHILE A RESIDUAL
UPPER TROUGH LINGERS OVER THE SOUTHEAST. QUESTION WILL BE WHERE
DEEPER MOISTURE RESIDES. WITH THE ECMWF THINK MOST OF THE CLOUD
COVER WILL BE HUGGING OUR SOUTHEAST CWA WITH MORE RESIDING ACROSS
THE SOUTHEAST...WHILE THE WESTERN CWA SEES MORE SUN DURING THE DAY.
TEMPERATURES GIVEN A LIGHT NE-E FLOW WILL BE CLOSER TO NORMAL...WITH
THE THREAT OF RAIN BEING LESS THAN 10 PERCENT.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AS OF 130 AM EDT SATURDAY...
TEMPERATURE/DEW POINT SPREAD WAS ALREADY CLOSE TO ZERO AT
KBCB/KLYH AND KDAN. HIGH CONFIDENCE OF IFR TO LIFR FOG ALONG AREA
RIVERS EARLY THIS MORNING WHICH WILL RESULT IN LIFR VISIBILITIES
AT KBCB AND KLWB.
ONCE FOG MIXES OUT IN THE MORNING THE REST OF THE DAY WILL BE VFR.
TIMING OF HOW FAST FOG LIFTS SHOULD BE BETWEEN 8AM AND 10AM. MID
AND HIGH LEVEL CLOUDS WILL ARRIVE SUNDAY THOUGH AS THE COLD FRONT
ENTERS THE OHIO VALLEY.
OUR NEXT CHANCE FOR WIDESPREAD AND PROLONGED SUB-VFR CONDITIONS
WILL COME SUNDAY NIGHT INTO MONDAY WHEN A COLD FRONT APPROACHES
FROM THE WEST...AND WHAT IS LEFT OF TROPICAL CYCLONE KAREN RIDES
NORTH THROUGH OR NEAR OUR REGION IN ADVANCE OF IT. THIS WOULD
ALLOW A TREND TOWARD DECREASING CEILING HEIGHTS AND INCREASED
COVERAGE OF RAIN. VISIBILITIES WOULD TREND LOWER AS
WELL...ESPECIALLY SUNDAY INTO MONDAY AS PRECIPITATION INTENSIFIES
AND FOG POTENTIAL INCREASES.
RAIN ENDS MONDAY NIGHT BUT THERE STILL MAY BE RESTRICTIONS IN
CEILING AND VISIBILITY AS PRECIP COULD STILL BE HEAVY ACROSS THE
VA/NC PIEDMONT WITH POTENTIALLY SOME FOG ACROSS SE WEST VA. A
DRIER PATTERN IS EXPECTED TUESDAY AND WEDNESDAY WITH MORNING FOG.
&&
.CLIMATE...
RECORD HIGH TEMPS FOR SATURDAY.
ROANOKE 98/1941
LYNCHBURG 96/1941
DANVILLE 98/1951
BLACKSBURG 86/1954
BLUEFIELD 85/2007
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...JH/WP
AVIATION...AMS/KK/KM
CLIMATE...RCS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
615 PM CDT SUN OCT 6 2013
.SHORT TERM...(TONIGHT AND MONDAY)
ISSUED AT 255 PM CDT SUN OCT 6 2013
UPPER LEVEL LOW PRESSURE SYSTEM WAS CHURNING EAST ACROSS IA/NORTHERN
ILL THIS AFTERNOON...WHILE THE SFC LOW WAS DISPLACED NORTHEAST OVER
THE UP OF MICH. UPPER LEVEL ENERGY AND MOISTURE WRAPPED AROUND THE
SYSTEM WAS RESULTING IN BANDS OF MOSTLY LIGHT RAIN SHOWERS
NORTH-SOUTH ACROSS MN/IA. THE SYSTEM WILL CONTINUE TO TRACK TO THE
EAST...DRAGGING THE LIGHT PCPN ACROSS THE FORECAST AREA AS IT GOES.
EXPECT SOME DIMINISHING TREND LATE THIS EVENING...GRADUALLY ENDING
AS IT WEAKENS AND MOVES EAST OVERNIGHT. AMOUNTS WILL BE MINIMAL.
HIGH PRESSURE BUILDS ACROSS THE REGION ON MONDAY...WITH AMPLE
SUNSHINE FOR MOST LOCATIONS TO KICK OFF THE NEW WORK WEEK.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 255 PM CDT SUN OCT 6 2013
FAIRLY QUIET FOR THE BETTER PART OF THE WORK WEEK...WITH LONGWAVE
RIDGE IN THE EAST AND TROUGH TO THE WEST. PRESSURE GRADIENT ALREADY
TIGHTENING BY TUESDAY...AND WILL STAY THAT WAY THROUGH FRIDAY.
SHOULD BE A FAIRLY BREEZY WEEK AS A RESULT...BUT THESE SOUTHERLY
WINDS WILL ALSO USHER MILDER AIR BACK INTO THE UPPER MISSISSIPPI
RIVER VALLEY. NOT EXPECTING 80S...BUT LOWER 70S ARE LIKELY FOR THE
LATER PART OF THE WORK WEEK. PRETTY NICE FALL CONDITIONS...SANS THE
WINDS...FOR THE NEXT FEW DAYS.
THE TROUGH MOVES OFF THE WEST COAST AND OVER THE CENTRAL U.S. BY
FRIDAY...WITH THE 500 MB LOW LIFTING OVER THE NORTHERN PLAINS.
GFS/EC/GEM ALL DEVELOP PCPN IN RESPONSE TO THE SYSTEM/S WARM
FRONT/WARM AIR ADVECTION WING...EXTENDING SOUTHEAST OF THE STACKED
LOW. THERE IS SOME DISAGREEMENT IN TIMING/STRENGTH OF THE SYSTEM AND
THE PCPN...ALTHOUGH ALL DO SUGGEST THAT THERE WILL BE SOME RAIN
CHANCES AS IT MOVES THROUGH. WILL LEAN ON THE CONSENSUS SOLUTION FOR
NOW.
ANY FROST/VALLEY FOG POTENTIAL LOOKS LIMITED THIS WEEK WITH THE
INCREASING WINDS PUTTING A DAMPER ON THE CHANCES. TUESDAY MORNING
HOLDS THE MOST PROMISE...WITH HIGH PRESSURE OVER WI AND WINDS STILL
LIGHT EAST OF THE MISSISSIPPI RIVER VALLEY. HIGH POTENTIAL IN THE
USUAL COLD SPOTS OF CENTRAL/NORTH-CENTRAL WI.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 615 PM CDT SUN OCT 6 2013
THE UPPER LEVEL LOW WAS OVER EASTERN IOWA LATE THIS AFTERNOON. THE
DEFORMATION CLOUDS AND LIGHT RAIN/DRIZZLE ON THE BACK SIDE OF THE
LOW EXTENDED FROM SOUTH CENTRAL MINNESOTA INTO NORTHWEST
WISCONSIN. AS THE UPPER LEVEL LOW MOVES OFF TO THE EAST/SOUTHEAST
TONIGHT IT WILL DRAG THE LOW CLOUDS IN THE DEFORMATION AREA ACROSS
THE REGION. SHOULD SEE THE CEILINGS DROP DOWN TO IFR AT KRST AND
MVFR AT KLSE. COULD ALSO SEE A BRIEF REDUCTION IN THE
VISIBILITY...BUT NOT EXPECTING THIS TO LAST VERY LONG OR VERY
CONFIDENT ON WHEN IT MAY OCCUR...SO HAVE OPTED TO STAY WITH VFR
VISIBILITIES FOR NOW. MODEL CONSENSUS BETWEEN THE 06.20Z RAP AND
06.18Z NAM IS FOR THE LOW CLOUDS IN THE DEFORMATION AREA TO CLEAR
OUT BEFORE SUNRISE WITH CLEAR SKIES EXPECTED FOR THE REMAINDER OF
THE PERIOD AS HIGH PRESSURE BUILDS IN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1213 PM CDT SAT OCT 5 2013
.UPDATE...
THE WARM FRONT IS INCHING NORTHWARD THIS MORNING. DENSE FOG IN
SOUTHEAST WI IMPROVED TO 1 TO 2 MILES...WHILE SHEBOYGAN AND PORT
WASHINGTON REMAIN SOCKED IN WITH THE LIGHT SOUTHEAST FLOW OFF THE
LAKE ON THE NORTH SIDE OF THE WARM FRONT. DENSE FOG ADVISORY IN
EFFECT UNTIL MID AFTERNOON THERE.
STRENGTHENING LOW LEVEL JET AND MOISTURE CONVERGENCE WITH A VORT MAX
MOVING OUT OF EASTERN IOWA IS LEADING TO INCREASING SHOWER COVERAGE
IN SOUTH CENTRAL WISCONSIN LATE THIS MORNING. THESE SHOWERS WILL
EXPAND/PROGRESS EASTWARD THROUGH EARLY AFTERNOON. 1000 J/KG OF MU
CAPE ALLOWING FOR A FEW EMBEDDED THUNDERSTORMS. WATCHING THE MORE
DISCRETE CELLS IN NORTH CENTRAL IL FOR STRENGTHENING...AS THAT
REGION HAS HIGHER CAPE AND BULK SHEAR VALUES. THESE VALUES WILL
GRADUALLY MOVE INTO SOUTHERN WI...BUT FOG AND LOW CLOUDS OVER
SOUTHERN WI WILL SLOW IT DOWN. LATEST HRRR KEEPS THE FORECAST
REFLECTIVITY FOR MIDDAY RATHER LIGHT. HIGH PRECIPITABLE WATER VALUES
WILL LEAD TO EFFICIENT RAINFALL THOUGH...SO WILL NEED TO WATCH FOR
FLOODING POTENTIAL ESPECIALLY IN URBAN AREAS.
WATER VAPOR IMAGERY SHOWS A STRONGER SHORTWAVE DOWN IN MISSOURI THAT
IS NOW FORECAST TO MOVE THROUGH NORTHEAST IL AROUND 00Z ALONG THE
SURFACE FRONTAL TROUGH INSTEAD OF SOUTHEAST WI. HOWEVER...THE
SURFACE TROUGH WILL EXTEND BACK INTO WEST CENTRAL WI...SO WHILE THE
STRONGEST 500MB SHORTWAVE WILL BE ABSENT...THERE WILL STILL BE
SURFACE CONVERGENCE...MODERATE BULK SHEAR...UPPER DIVERGENCE AND
STRONG 700MB OMEGA OVER SOUTHERN WI AT 00Z TO ALLOW FOR THUNDERSTORMS.
ANOTHER ROUND OF WIDESPREAD CONVECTION IS EXPECTED WITH THIS
FEATURE...MOST LIKELY BETWEEN 05 PM AND 10 PM IN THE MKX FORECAST
AREA. THIS WILL BE THE PERIOD FOR HEAVIEST RAIN AND STRONGEST WIND
GUSTS AND BEST POTENTIAL FOR SEVERE GUSTS. UNIDIRECTIONAL WIND
THROUGH THE COLUMN WILL LEAD TO THUNDERSTORMS QUICKLY DEVELOPING
INTO LINE SEGMENTS.
&&
.AVIATION/18Z TAFS/...
FOG CONTINUES TO THIN EXCEPT TOWARD SHEBOYGAN AND PORT WASHINGTON
AHEAD OF THE WARM FRONT AND WITH THE INFLUENCE OF MARINE AIR. CIGS
WILL REMAIN IFR OR LOWER UNTIL SCATTERED SHOWERS WITH A FEW EMBEDDED
THUNDERSTORMS SPREAD ACROSS SOUTH CENTRAL AND SOUTHEAST WI THROUGH
EARLY AFTERNOON. ANOTHER ROUND OF WIDESPREAD CONVECTION WITH HEAVY
RAIN AND STRONG WIND GUSTS WILL IMPACT SOUTHERN WI BETWEEN 5 PM TO
10 PM.
CONVECTION WILL END FROM WEST TO EAST SOON AFTER MIDNIGHT AS
OCCLUDED FRONT SLIDES EAST OF AREA.
&&
.MARINE...
WILL CONTINUE DENSE FOG ADVY INTO THE EVENING AS WARM...MOIST AIR
CONTINUES TO MOVE ACROSS COOLER NEAR SHORE WATERS OF LAKE MI.
SCATTERED MORNING AND EARLY AFTN CONVECTION WL GIVE WAY TO A MORE
WIDESPREAD PERIOD LATER THIS AFTN AND EVE.
&&
.PREV DISCUSSION... /ISSUED 305 AM CDT SAT OCT 5 2013/
TODAY AND TONIGHT - CONFIDENCE...MEDIUM.
WL EXPAND DENSE FOG ADVY INTO MORE OF SOUTHEAST THROUGH THE EARLY
MORNING AND CONTINUE 14Z EXPIRATION. AS WARM FRONT IN NORTHERN IL
BEGINS TO SHIFT NWD...DENSE FOG SHOULD THIN THROUGH THE
MORNING...BUT NORTHERN AREAS MAY NEED TO BE EXTENDED A FEW HOURS.
OTRW...WEAKER WARM AIR ADVECTION WL CARRY NMRS CONVECTION ACROSS WRN
CWA EARLY THIS MRNG...HOWEVER FOCUS OF WAA REMAINS OVER NRN HALF OF
WI EARLY. LOW LEVEL JET STRENGTHENS ONCE AGAIN AHEAD OF STRONG
UPPER LOW OVER NORTHERN PLAINS LATER THIS MRNG AND AFTERNOON ACROSS
NRN IL/SRN WI REGION. SFC LOW SLIGHTLY WWD POSITION AT 12Z COMPARED
TO EARLIER RUNS...AND 00Z NAM CONTINUES TO ADJUST ITS TIMING AND
POSITION TO MORE FAVORED GFS AND ECMWF. INCREASING SOUTH WINDS
AHEAD OF SFC LOW WL ALLOW WARM FRONT OVER NRN IL TO MOVE NWD ACROSS
PORTIONS OF SRN WI TODAY AS SURFACE OCCLUSION BEARS DOWN ON THE
AREA. OCCLUSION MAKES SLOW EWD PROGRESS TODAY...AND LOOKS LIKE IT
WILL EXIT ERN CWA AROUND 06Z. STRONGER LAYER Q-VECTOR CONVERGENCE
SPREADS IN THIS AFTN AND TNGT WITH OCCLUSION AND UPPER LEVEL SHORT
WAVE. MUCAPE CURRENTLY AROUND 500 J/KG EXPECTED TO INCREASE TO
1500-2000 J/KG LATER TODAY AHEAD OF OCCLUSION. NO PROBLEM WITH
AVAILABLE SHEAR FAVORING MULTICELLS AND SUPERCELLS MODE. IF LOW
CLOUDS CLEAR OUT IN TIME ACROSS PORTIONS OF THE CWA...SHEAR AND
INSTABILITY SHOULD BE ENOUGH TO TRIGGER STRONG TO SEVERE
CONVECTION. CAN NOT RULE OUT A TORNADO CONSIDERING STRENGTH OF
FORCING. PWAT REMAINS OVER 200 PERCENT OF NORMAL...SO IF EXPECTED
NORTH TO SOUTH LINE OF CONVECTION LINGERS OVER AREA...POTENTIAL FOR
FLASH FLOODING. WARM CLOUD DEPTH PRIOR TO AFTN CONVECTION OVER 11K
FEET. FORTUNATELY HEAVIEST RAINFALL OF THE PAST SEVERAL DAYS HAS
BEEN MOSTLY WEST AND SOUTH OF CWA.
WILL CONTINUE SMALLER THREAT FOR CONVECTION LATE TONIGHT IN ERN CWA
DUE TO LINGERING LOW LEVEL JET IN THE AREA.
SUNDAY - CONFIDENCE...MEDIUM
SLOW MOVING NEARLY STACKED LOW PROGGD TO TRAVERSE FROM WESTERN IOWA
INTO CNTRL IL THROUGH SUNDAY NIGHT. PLENTY OF DRY AIR WRAPPING
AROUND THIS SYSTEM WITH DRY SLOT ACRS MUCH OF WI. 850 COLD ADVECTION
FROM THE SOUTHWEST. SOME MODELS SHOW CLOSE TO ZERO CELSIUS TOWARDS
THE IL BORDER BY LATER SUNDAY NIGHT. THE NAM MODEL IS THE ONLY MODEL
TO DEVELOP SOME DEF ZONE PRECIP SUNDAY NIGHT WITH A BIT MORE 700 RH
ON THE NORTHERN SIDE OF THE SYSTEM THAN THE OTHER MODELS. SURFACE
TROUGH AXIS EXTENDS ACROSS NRN AND WRN WI SO GIVEN THE PROGGD
PLACEMENT OF DRY RH AND QPF...WILL REMOVE POPS FOR SUNDAY BUT LEAVE
THEM IN FOR SUNDAY NIGHT.
MONDAY - CONFIDENCE...MEDIUM
MODEL CONSENSUS IS TO MOVE LOW FROM CNTRL IL INTO NE IN. BROAD 850
MILLIBAR CIRCULATION BECOMES CLOSED ACROSS LWR MI DURING THE
AFTERNOON. SURFACE/850 TROUGH EXTENDS FROM THE LWR MI LOW INTO
CNTRL/SRN WI ENHANCING LOW LEVEL FORCING. IN ADDITION TO THE RIPPLES
WRAPPING WEST AND SOUTHWEST AROUND THE PERIPHERY OF THE UPPER LOW
CENTER. SO WILL HAVE CHANCE POPS FOR SHRA IN THIS PATTERN. THE 00Z
ECMWF HAS THROWN A BIT OF A WRENCH INTO THINGS BY COMING IN WITH A
MUCH MORE PROGRESSIVE SOLUTION HOWEVER GIVEN THE CURRENT LOCATION
AND STRUCTURE OF THIS SYSTEM WOULD APPEAR THAT LEANING TOWARDS A
SLOWER SOLUTION HAS MORE CREDENCE AT THIS POINT. WILL NOT JUMP ON
THIS NEW ECMWF DEVELOPMENT YET ESP WITH THE NAM/GFS/GEM ALL SHOWING
A SLOWER LOOK.
TUESDAY - CONFIDENCE...MEDIUM
LOW PLODS INTO THE EASTERN GREAT LAKES WITH CYCLONIC FLOW ON THE
WESTERN SIDE STILL LINGERING INTO EASTERN WI. ALLBLEND HAS SOME
SLIGHT POPS IN THE EAST AND FOR NOW THIS IS FINE. WITH THE FASTER
00Z ECMWF WAS TEMPTED TO PULL THIS POP BUT AFTER COORD WITH LOT/GRB
WAS DECIDED TO LEAVE THIS AS IS FOR NOW AND STICK WITH THE CONSENSUS.
APPEARS INFLUENCE OF THE UPPER CIRCULATION GETS FAR ENOUGH AWAY WITH
SURFACE RIDGING BUILDING IN FOR THE AFTERNOON.
WEDNESDAY THROUGH FRIDAY - CONFIDENCE...MEDIUM
SURFACE/850 HIGH CENTERED OVER THE AREA ON WEDNESDAY. WITH A SHIFT
TO THE EAST ON THURSDAY AND FRIDAY...THIS SETS UP A RETURN SOUTHERLY
FLOW WHICH BRINGS MILDER 925 TEMPS INTO THE AREA.
AVIATION/12Z TAFS/...AREAS OF DENSE FOG WILL GRADUALLY THIN THIS
MORNING AS WINDS INCREASE AS WARM FRONT IN NRN IL ADVANCES NORTH.
CIGS MAY EVEN INCREASE TO VFR FOR A TIME BEFORE NMRS CONVECTION
SPREADS IN LATE MRNG AND AFTN. CONVECTION SHOULD END OVERNIGHT WRN
AREAS AS OCCLUDED FRONT SLIDES EAST OF AREA.
MARINE...WL CONTINUE DENSE FOG ADVY INTO THE AFTN AS WARM...MOIST AIR
CONTINUES TO MOVE ACROSS COOLER NEAR SHORE WATERS OF LAKE MI.
SCATTERED MORNING AND EARLY AFTN CONVECTION WL GIVE WAY TO A MORE
WIDESPREAD PERIOD LATER THIS AFTN AND EVE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 3 PM CDT THIS AFTERNOON FOR WIZ052-060.
LM...DENSE FOG ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ643>646.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...MBK
SUNDAY THROUGH FRIDAY...COLLAR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 AM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT SAT OCT 5 2013
MOST EFFORT THIS FORECAST SHIFT WAS PUT TOWARD GETTING THE NEXT 24
HOURS AS ACCURATE AS POSSIBLE. SCREAMING MESSAGE IS THE SLOWER
EASTWARD PROGRESSION OF THE FRONT AND INSTABILITY...MAKING FOR A
BIT HIGHER SEVERE WEATHER CHANCE IN WI TODAY.
WATER VAPOR SHOWING THE MONSTER LOW THAT BROUGHT 25-45 INCHES OF
SNOW TO SD OVER CENTRAL SD AT 08Z AND NEARLY STATIONARY. OCCLUDED
FRONT CURRENTLY POSITIONED FROM KRWF TO KCCY...WHERE THE TRIPLE
POINT IS LOCATED. THE WARM FRONT EXTENDS EAST FROM NEAR KCCY TO
THE DELLS IN WI...WITH THE SURFACE COLD FRONT RUNNING SOUTH FROM
KCCY. THIS WARM FRONT IS THE LEADING EDGE OF THE HIGHER DEWPOINT
AIR...MIDDLE 60S...AND THE ENERGY FOR THIS AFTERNOONS STORMS. THE
OVERNIGHT CONVECTION HAS NOW PASSED OFF TO THE EAST...AND WITH IT
THE FLASH FLOOD THREAT.
EVALUATING THE 04.00Z MODEL GUIDANCE...THE TREND IS SLOWER WITH
THE NORTHEAST PROGRESSION OF THE OCCLUDED/COLD FRONT. THIS ALLOWS
MORE OF THE FORECAST AREA IN WI TO BE PRE-FRONTAL AND IN THE WARM
SECTOR FOR A HIGHER PROBABILITY OF SEVERE WEATHER. AS THE DAY
PROGRESSES...QVECTOR CONVERGENCE WILL INCREASE AS A SHORTWAVE
TROUGH IN COLORADO ROTATES AROUND THE LARGER SD TROUGH AND BEGINS
ITS EASTWARD PROGRESSION. AS THE FORCING BEGINS TO
INCREASE...NEAR/POST FRONTAL SHOWERS WILL LIKELY DEVELOP MUCH LIKE
SEEN ON RADAR ALONG I-35 EARLY THIS MORNING. ALSO...BETTER UPPER
LEVEL FORCING WILL BEGIN TO WORK TOWARD THE WARM SECTOR AND WORK
WITH 0-2KM THETA-E CONVERGENCE ALONG THE FRONT. INSTABILITY IN THE
WARM SECTOR WILL HIGHLY DEPEND ON THE EXTENT OF THE SHOWERS AND
CLOUDS OVER WI...HOWEVER BECAUSE THE DEWPOINTS ARE ALREADY MIDDLE
60S...AT LEAST MARGINAL INSTABILITY WILL BE PRESENT BY 18Z. MUCAPES
AROUND 1000-1500 J/KG LOOK TO BE A GOOD ESTIMATE ON AFTERNOON
CAPE...POSSIBLY HIGHER WITH MORE CLOUD BREAKS.
WIND SHEAR LOOKS TO INCREASE TODAY BUT RIGHT ON THE COLD/OCCLUDED
FRONTAL BOUNDARY...TO MAKE IT A MARGINAL SUPERCELL DAY WITH
MULTI-CELLS ALSO PRESENT. THE 05.06Z NAM AND 05.07Z RAP BOTH SUGGEST
NEAR 40 KTS OF 0-6KM SHEAR...CERTAINLY ENOUGH FOR SUPERCELLS. THE
05.07Z RAP MIXES ALL THE PRE-FRONTAL SURFACE WINDS TO SOUTHERLY. THE
05.06Z NAM AND LATEST HRRR RUNS ARE VERY AGREEABLE THAT THE WARM
FRONT WILL SHIFT NORTH TO ABOUT BLACK RIVER FALLS WI TODAY...VERY
CLOSE TO THE SPC DAY 1 NORTHERN EXTENT OF THE SLIGHT RISK. EASTERLY
FLOW IS FOUND NORTH OF THE WARM FRONT...WHICH EXTENDS TO THE EAST
TOWARD KGRB...SO A GOOD CONVERGENT BOUNDARY. WHILE TORNADO
PROBABILITIES DONT LOOK HIGH...THE TRIPLE POINT AREA AND ALONG THAT
WARM FRONT THIS AFTERNOON WILL BE A FOCAL POINT.
OTHERWISE...DAMAGING WIND SEGMENTS OR LARGE HAIL ARE THE MAIN
THREATS FROM THE STORMS IN WI. NORTH OF THE WARM FRONT...LOW-LEVEL
INVERTED CONDITIONS AND ELEVATED STORMS ARE FAVORED...HEAVY RAIN IS
THE MAIN THREAT...WITH AN ISOLATED HAIL STORM POSSIBLE. THE FRONT
SHOULD SHIFT EAST OF THE FORECAST AREA BY EARLY EVENING WITH STRONG
DEWPOINT DECREASES. THUS...THE MAIN SEVERE WEATHER THREAT LOOKS TO
BE ABOUT 1 PM TO 5 PM.
BY TONIGHT...THE NE AND EASTERNMOST FORECAST AREA MAY STILL HAVE
SOME RAIN REMAINING. HAVE SLOWED THAT SLIGHTLY FROM THE PREVIOUS
FORECAST. A DECREASING TREND OCCURS THROUGH THE EVENING AS WEATHER
SHIFTS EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 413 AM CDT SAT OCT 5 2013
THE LATEST MODEL CONSENSUS IS TO NOW KEEP THE DEFORMATION
ASSOCIATED WITH THE CYCLONIC MOIST FLOW WRAPPING AROUND THE LOW TO
THE WEST-NORTHWEST ON SATURDAY. THIS IS HIGHLY DEPENDENT ON THE
TRACK OF THE LOW WHICH IS A BIT FURTHER SOUTH IN THE LATEST
GUIDANCE. IN ANY CASE...CHANGES WERE MADE TO SUNDAY TO TRY AND DRY
IT OUT WITH THE RAIN SHOWERS JUST WEST OF THE AREA. ALTHOUGH THE
CONSENSUS OF THE MODELS IS TO BRING THAT BAND INTO THE FORECAST
AREA FOR MONDAY NOW...THE LATEST 05.00Z ECMWF IS MUCH MORE
PROGRESSIVE AND RAPIDLY SHIFTS THE SHOWERS EAST. HAVE A SMALL
CHANCE OF SHOWERS TO ADDRESS THAT SITUATION.
THE REMAINDER OF THE PERIOD IS DOMINATED BY DRY WEATHER UNDER
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1150 AM CDT SAT OCT 5 2013
FRONTAL BOUNDARY WILL CONTINUE TO ROTATE NORTHEAST ACROSS THE REGION
THIS AFTERNOON. ITS ALREADY CLEARED KRST...AND WILL DO SO AT KLSE BY
MID-AFTERNOON. COULD BE A BRIEF SWITCH TO WESTERLY WINDS FOR AN HOUR
OR TWO...THEN SHIFT BACK TO MORE SOUTH-SOUTHWEST. AN UPPER LEVEL
SHORTWAVE MOVING IN FROM THE SOUTHWEST WILL WORK ON THE FRONT TO
SPAWN SCT SHRA/TS NEAR THE SFC FRONT...AND THIS ACTIVITY COULD
IMPACT THE TAF SITES FOR A FEW HOURS THIS AFTERNOON.
SKIES SHOULD CLEAR THIS EVENING AS DRY AIR WRAPS INTO THE STORM
SYSTEM...PER LATEST SATELLITE IMAGERY. MASS OF MVFR/IFR CIGS
ASSOCIATED WITH THE MAIN SFC LOW WITH THE SYSTEM...CURRENTLY ACROSS
SD. THE LOW WILL MOVE EAST/NORTHEAST TONIGHT...BRINGING THE CLOUD
SHIELD IN NEAR 12Z. NUMERICAL GUIDANCE SUGGEST ONLY VFR CIGS BY THAT
TIME...BUT HARD TO ARGUE WITH SFC OBS/SATELLITE...PLUS RH FIELDS
SUPPORT LOWER CIGS. WILL BRING IN SOME MVFR CIGS FOR SUN MORNING.
ANOTHER FORECAST CONSIDERATION IS THE POTENTIAL FOR FOG...ESPECIALLY
IN THE RIVER VALLEYS. WITH EXPECTED CLEARING TONIGHT...THE SFC
PRESSURE GRADIENT BECOMING BAGGY - THUS LIGHT WINDS...AND RECENT
RAINS TO MOISTEN THE BOUNDARY LAYER...IT COULD BE FAVORABLE FOR SUB
1SM AT KLSE. HOW LONG IT STAYS CLEAR WILL PROBABLY BE THE BIGGEST
FACTOR...AND A LOT OF UNCERTAINTY HERE. WILL ADD BCFG FOR NOW.
&&
.HYDROLOGY...
ISSUED AT 413 AM CDT SAT OCT 5 2013
CONCERNING THE FLASH FLOOD WATCH...WITH CURRENT CONVECTION EAST
OF THE AREA...MAIN THREAT HAS DIMINISHED. AS AFTERNOON CONVECTION
INCREASES...IT SHOULD BE AFFECTING AREAS THAT HAVE HAD LESS RAIN
OVERALL THAN THOSE WEST OF THE MISS RIVER. AREAS EAST OF THE MISS
RIVER CAN TAKE ANOTHER 1-2 INCHES...ESPECIALLY SWRN WI. THERE IS A
SMALL PROBABILITY OF LOCALIZED FLASH FLOODING TODAY IN THE CENTRAL
WI CORRIDOR IN THE PRE-FRONTAL AIR MASS WHICH WILL STILL HAVE 1.25
TO 1.75 INCH PRECIPITABLE WATER VALUES. RAIN RATES ARE EXPECTED TO
BE HIGH...PROBABLY 2 TO 3 INCH PER HOUR SHOULD CAPE DEVELOP AS
FORECAST. THE SLOW MOVEMENT OF THE FRONT DOES GIVE SOME CONCERN
FOR FLOODING SO WILL ISSUE ANOTHER HYDROLOGICAL DISCUSSION FOR
THAT AREA AND CANCEL THE FLASH FLOOD WATCH.
THERE ARE SOME RIVER RESPONSES CURRENTLY OCCURRING. MONITORING THE
ROOT RIVER BASIN AND THE UPPER IOWA RIVERS BOTH HAVE RESPONSES.
ALSO THE WHITEWATER RIVER MIDDLE FORK THAT RUNS THROUGH WHITEWATER
STATE PARK IS RISING. AT THIS TIME THESE WILL APPROACH FLOOD STAGE
BUT IT IS BELIEVED THEY WILL NOT REACH IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
HYDROLOGY....BAUMGARDT
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
634 AM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 523 AM CDT SAT OCT 5 2013
WITH CONVECTION SHIFTING EAST AND LACK OF OVERALL ACTIVITY
EXPECTED THROUGH THE NEXT SEVERAL HOURS...HAVE TRENDED THE MORNING
MUCH DRIER. ONLY ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
MORNING...RAMPING UP TOWARD AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT SAT OCT 5 2013
MOST EFFORT THIS FORECAST SHIFT WAS PUT TOWARD GETTING THE NEXT 24
HOURS AS ACCURATE AS POSSIBLE. SCREAMING MESSAGE IS THE SLOWER
EASTWARD PROGRESSION OF THE FRONT AND INSTABILITY...MAKING FOR A
BIT HIGHER SEVERE WEATHER CHANCE IN WI TODAY.
WATER VAPOR SHOWING THE MONSTER LOW THAT BROUGHT 25-45 INCHES OF
SNOW TO SD OVER CENTRAL SD AT 08Z AND NEARLY STATIONARY. OCCLUDED
FRONT CURRENTLY POSITIONED FROM KRWF TO KCCY...WHERE THE TRIPLE
POINT IS LOCATED. THE WARM FRONT EXTENDS EAST FROM NEAR KCCY TO
THE DELLS IN WI...WITH THE SURFACE COLD FRONT RUNNING SOUTH FROM
KCCY. THIS WARM FRONT IS THE LEADING EDGE OF THE HIGHER DEWPOINT
AIR...MIDDLE 60S...AND THE ENERGY FOR THIS AFTERNOONS STORMS. THE
OVERNIGHT CONVECTION HAS NOW PASSED OFF TO THE EAST...AND WITH IT
THE FLASH FLOOD THREAT.
EVALUATING THE 04.00Z MODEL GUIDANCE...THE TREND IS SLOWER WITH
THE NORTHEAST PROGRESSION OF THE OCCLUDED/COLD FRONT. THIS ALLOWS
MORE OF THE FORECAST AREA IN WI TO BE PRE-FRONTAL AND IN THE WARM
SECTOR FOR A HIGHER PROBABILITY OF SEVERE WEATHER. AS THE DAY
PROGRESSES...QVECTOR CONVERGENCE WILL INCREASE AS A SHORTWAVE
TROUGH IN COLORADO ROTATES AROUND THE LARGER SD TROUGH AND BEGINS
ITS EASTWARD PROGRESSION. AS THE FORCING BEGINS TO INCREASE...NEAR/POST
FRONTAL SHOWERS WILL LIKELY DEVELOP MUCH LIKE SEEN ON RADAR ALONG
I-35 EARLY THIS MORNING. ALSO...BETTER UPPER LEVEL FORCING WILL
BEGIN TO WORK TOWARD THE WARM SECTOR AND WORK WITH 0-2KM THETA-E
CONVERGENCE ALONG THE FRONT. INSTABILITY IN THE WARM SECTOR WILL HIGHLY
DEPEND ON THE EXTENT OF THE SHOWERS AND CLOUDS OVER WI...HOWEVER
BECAUSE THE DEWPOINTS ARE ALREADY MIDDLE 60S...AT LEAST MARGINAL
INSTABILITY WILL BE PRESENT BY 18Z. MUCAPES AROUND 1000-1500 J/KG
LOOK TO BE A GOOD ESTIMATE ON AFTERNOON CAPE...POSSIBLY HIGHER
WITH MORE CLOUD BREAKS.
WIND SHEAR LOOKS TO INCREASE TODAY BUT RIGHT ON THE COLD/OCCLUDED
FRONTAL BOUNDARY...TO MAKE IT A MARGINAL SUPERCELL DAY WITH
MULTI-CELLS ALSO PRESENT. THE 05.06Z NAM AND 05.07Z RAP BOTH SUGGEST
NEAR 40 KTS OF 0-6KM SHEAR...CERTAINLY ENOUGH FOR SUPERCELLS. THE
05.07Z RAP MIXES ALL THE PRE-FRONTAL SURFACE WINDS TO SOUTHERLY. THE
05.06Z NAM AND LATEST HRRR RUNS ARE VERY AGREEABLE THAT THE WARM
FRONT WILL SHIFT NORTH TO ABOUT BLACK RIVER FALLS WI TODAY...VERY
CLOSE TO THE SPC DAY 1 NORTHERN EXTENT OF THE SLIGHT RISK. EASTERLY
FLOW IS FOUND NORTH OF THE WARM FRONT...WHICH EXTENDS TO THE EAST
TOWARD KGRB...SO A GOOD CONVERGENT BOUNDARY. WHILE TORNADO
PROBABILITIES DONT LOOK HIGH...THE TRIPLE POINT AREA AND ALONG THAT
WARM FRONT THIS AFTERNOON WILL BE A FOCAL POINT.
OTHERWISE...DAMAGING WIND SEGMENTS OR LARGE HAIL ARE THE MAIN
THREATS FROM THE STORMS IN WI. NORTH OF THE WARM FRONT...LOW-LEVEL
INVERTED CONDITIONS AND ELEVATED STORMS ARE FAVORED...HEAVY RAIN IS
THE MAIN THREAT...WITH AN ISOLATED HAIL STORM POSSIBLE. THE FRONT
SHOULD SHIFT EAST OF THE FORECAST AREA BY EARLY EVENING WITH STRONG
DEWPOINT DECREASES. THUS...THE MAIN SEVERE WEATHER THREAT LOOKS TO
BE ABOUT 1 PM TO 5 PM.
BY TONIGHT...THE NE AND EASTERNMOST FORECAST AREA MAY STILL HAVE
SOME RAIN REMAINING. HAVE SLOWED THAT SLIGHTLY FROM THE PREVIOUS
FORECAST. A DECREASING TREND OCCURS THROUGH THE EVENING AS WEATHER
SHIFTS EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 413 AM CDT SAT OCT 5 2013
THE LATEST MODEL CONSENSUS IS TO NOW KEEP THE DEFORMATION
ASSOCIATED WITH THE CYCLONIC MOIST FLOW WRAPPING AROUND THE LOW TO
THE WEST-NORTHWEST ON SATURDAY. THIS IS HIGHLY DEPENDENT ON THE
TRACK OF THE LOW WHICH IS A BIT FURTHER SOUTH IN THE LATEST
GUIDANCE. IN ANY CASE...CHANGES WERE MADE TO SUNDAY TO TRY AND DRY
IT OUT WITH THE RAIN SHOWERS JUST WEST OF THE AREA. ALTHOUGH THE
CONSENSUS OF THE MODELS IS TO BRING THAT BAND INTO THE FORECAST
AREA FOR MONDAY NOW...THE LATEST 05.00Z ECMWF IS MUCH MORE
PROGRESSIVE AND RAPIDLY SHIFTS THE SHOWERS EAST. HAVE A SMALL
CHANCE OF SHOWERS TO ADDRESS THAT SITUATION.
THE REMAINDER OF THE PERIOD IS DOMINATED BY DRY WEATHER UNDER
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 634 AM CDT SAT OCT 5 2013
COLD/OCCLUDED FRONT CONTINUED TO WORK ITS WAY INTO AND ACROSS THE
FCST AREA EARLY THIS MORNING. AS OF 11Z IT WAS NEAR A KOWA-KAUM-KOLZ
LINE. SOUTHWEST OF THIS BOUNDARY CONDITIONS WERE GENERALLY GOOD VFR
WITH ONLY ISOLATED -SHRA. NORTHEAST OF THE BOUNDARY...CIGS WERE
HIGHLY VARIABLE RANGING FROM LIFR TO VFR. CIGS GENERALLY IMPROVED
BEHIND CLUSTERS OF CONVECTION OVERNIGHT...THEN DROPPING BACK DOWN A
COUPLE HOURS LATER. FRONT MAKING SLOW PROGRESS AND VARYING TIMING
SOLUTIONS AMONG THE MODELS...BUT APPEARS FRONT/BOUNDARY WILL LIFT
NORTHEAST OF KRST AROUND 14Z AND KLSE AROUND 19Z. WITH FRONT PAST KRST
AROUND 14Z...CONVECTION CHANCES DIMINISH FOR THE DAY AND ONLY
CARRIED VCSH IN THE 17-20Z TIME-FRAME. WITH FRONT NEAR KLSE AT
MID-DAY AND PEAK HEATING...CONTINUED A -SHRA/VCSH MENTION IN THE
MAINLY 19-22Z PERIOD. BOUNDARY CONTINUES LIFTING NORTHEAST LATE THIS
AFTERNOON/TONIGHT WITH FALLING DEW POINTS AND A DRIER AIRMASS
SPREADING ACROSS THE AREA. TREND FOR ONLY SCT CLOUDS TONIGHT
CONTINUES TO LOOK GOOD.
GIVEN THE RECENT RAINS...WILL HAVE TO WATCH VALLEY LOCATIONS FOR
BR/FG LATE TONIGHT IF SKIES DO END UP MOSTLY CLEAR AND THE VALLEY
WINDS DECOUPLE. APPEARS TO BE ENOUGH GRADIENT WINDS LATER TONIGHT
AND LEFT ANY BR/FG MENTION AFTER 09Z OUT OF KLSE FOR NOW.
&&
.HYDROLOGY...
ISSUED AT 413 AM CDT SAT OCT 5 2013
CONCERNING THE FLASH FLOOD WATCH...WITH CURRENT CONVECTION EAST
OF THE AREA...MAIN THREAT HAS DIMINISHED. AS AFTERNOON CONVECTION
INCREASES...IT SHOULD BE AFFECTING AREAS THAT HAVE HAD LESS RAIN
OVERALL THAN THOSE WEST OF THE MISS RIVER. AREAS EAST OF THE MISS
RIVER CAN TAKE ANOTHER 1-2 INCHES...ESPECIALLY SWRN WI. THERE IS A
SMALL PROBABILITY OF LOCALIZED FLASH FLOODING TODAY IN THE CENTRAL
WI CORRIDOR IN THE PRE-FRONTAL AIR MASS WHICH WILL STILL HAVE 1.25
TO 1.75 INCH PRECIPITABLE WATER VALUES. RAIN RATES ARE EXPECTED TO
BE HIGH...PROBABLY 2 TO 3 INCH PER HOUR SHOULD CAPE DEVELOP AS
FORECAST. THE SLOW MOVEMENT OF THE FRONT DOES GIVE SOME CONCERN
FOR FLOODING SO WILL ISSUE ANOTHER HYDROLOGICAL DISCUSSION FOR
THAT AREA AND CANCEL THE FLASH FLOOD WATCH.
THERE ARE SOME RIVER RESPONSES CURRENTLY OCCURRING. MONITORING THE
ROOT RIVER BASIN AND THE UPPER IOWA RIVERS BOTH HAVE RESPONSES.
ALSO THE WHITEWATER RIVER MIDDLE FORK THAT RUNS THROUGH WHITEWATER
STATE PARK IS RISING. AT THIS TIME THESE WILL APPROACH FLOOD STAGE
BUT IT IS BELIEVED THEY WILL NOT REACH IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE.......BAUMGARDT
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
HYDROLOGY....BAUMGARDT
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
525 AM CDT SAT OCT 5 2013
.UPDATE...
ISSUED AT 523 AM CDT SAT OCT 5 2013
WITH CONVECTION SHIFTING EAST AND LACK OF OVERALL ACTIVITY
EXPECTED THROUGH THE NEXT SEVERAL HOURS...HAVE TRENDED THE MORNING
MUCH DRIER. ONLY ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE
MORNING...RAMPING UP TOWARD AFTERNOON.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT SAT OCT 5 2013
MOST EFFORT THIS FORECAST SHIFT WAS PUT TOWARD GETTING THE NEXT 24
HOURS AS ACCURATE AS POSSIBLE. SCREAMING MESSAGE IS THE SLOWER
EASTWARD PROGRESSION OF THE FRONT AND INSTABILITY...MAKING FOR A
BIT HIGHER SEVERE WEATHER CHANCE IN WI TODAY.
WATER VAPOR SHOWING THE MONSTER LOW THAT BROUGHT 25-45 INCHES OF
SNOW TO SD OVER CENTRAL SD AT 08Z AND NEARLY STATIONARY. OCCLUDED
FRONT CURRENTLY POSITIONED FROM KRWF TO KCCY...WHERE THE TRIPLE
POINT IS LOCATED. THE WARM FRONT EXTENDS EAST FROM NEAR KCCY TO
THE DELLS IN WI...WITH THE SURFACE COLD FRONT RUNNING SOUTH FROM
KCCY. THIS WARM FRONT IS THE LEADING EDGE OF THE HIGHER DEWPOINT
AIR...MIDDLE 60S...AND THE ENERGY FOR THIS AFTERNOONS STORMS. THE
OVERNIGHT CONVECTION HAS NOW PASSED OFF TO THE EAST...AND WITH IT
THE FLASH FLOOD THREAT.
EVALUATING THE 04.00Z MODEL GUIDANCE...THE TREND IS SLOWER WITH
THE NORTHEAST PROGRESSION OF THE OCCLUDED/COLD FRONT. THIS ALLOWS
MORE OF THE FORECAST AREA IN WI TO BE PRE-FRONTAL AND IN THE WARM
SECTOR FOR A HIGHER PROBABILITY OF SEVERE WEATHER. AS THE DAY
PROGRESSES...QVECTOR CONVERGENCE WILL INCREASE AS A SHORTWAVE
TROUGH IN COLORADO ROTATES AROUND THE LARGER SD TROUGH AND BEGINS
ITS EASTWARD PROGRESSION. AS THE FORCING BEGINS TO INCREASE...NEAR/POST
FRONTAL SHOWERS WILL LIKELY DEVELOP MUCH LIKE SEEN ON RADAR ALONG
I-35 EARLY THIS MORNING. ALSO...BETTER UPPER LEVEL FORCING WILL
BEGIN TO WORK TOWARD THE WARM SECTOR AND WORK WITH 0-2KM THETA-E
CONVERGENCE ALONG THE FRONT. INSTABILITY IN THE WARM SECTOR WILL HIGHLY
DEPEND ON THE EXTENT OF THE SHOWERS AND CLOUDS OVER WI...HOWEVER
BECAUSE THE DEWPOINTS ARE ALREADY MIDDLE 60S...AT LEAST MARGINAL
INSTABILITY WILL BE PRESENT BY 18Z. MUCAPES AROUND 1000-1500 J/KG
LOOK TO BE A GOOD ESTIMATE ON AFTERNOON CAPE...POSSIBLY HIGHER
WITH MORE CLOUD BREAKS.
WIND SHEAR LOOKS TO INCREASE TODAY BUT RIGHT ON THE COLD/OCCLUDED
FRONTAL BOUNDARY...TO MAKE IT A MARGINAL SUPERCELL DAY WITH
MULTICELLS ALSO PRESENT. THE 05.06Z NAM AND 05.07Z RAP BOTH
SUGGEST NEAR 40 KTS OF 0-6KM SHEAR...CERTAINLY ENOUGH FOR
SUPERCELLS. THE 05.07Z RAP MIXES ALL THE PRE-FRONTAL SURFACE
WINDS TO SOUTHERLY. THE 05.06Z NAM AND LATEST HRRR RUNS ARE VERY
AGREEABLE THAT THE WARM FRONT WILL SHIFT NORTH TO ABOUT BLACK
RIVER FALLS WI TODAY...VERY CLOSE TO THE SPC DAY 1 NORTHERN EXTENT
OF THE SLIGHT RISK. EASTERLY FLOW IS FOUND NORTH OF THE WARM
FRONT...WHICH EXTENDS TO THE EAST TOWARD KGRB...SO A GOOD
CONVERGENT BOUNDARY. WHILE TORNADO PROBABILITIES DONT LOOK
HIGH...THE TRIPLE POINT AREA AND ALONG THAT WARM FRONT THIS
AFTERNOON WILL BE A FOCAL POINT. OTHERWISE...DAMAGING WIND
SEGMENTS OR LARGE HAIL ARE THE MAIN THREATS FROM THE STORMS IN WI.
NORTH OF THE WARM FRONT...LOW-LEVEL INVERTED CONDITIONS AND
ELEVATED STORMS ARE FAVORED...HEAVY RAIN IS THE MAIN THREAT...WITH AN
ISOLATED HAIL STORM POSSIBLE. THE FRONT SHOULD SHIFT EAST OF THE
FORECAST AREA BY EARLY EVENING WITH STRONG DEWPOINT DECREASES.
THUS...THE MAIN SEVERE WEATHER THREAT LOOKS TO BE ABOUT 1 PM TO 5
PM.
BY TONIGHT...THE NE AND EASTERNMOST FORECAST AREA MAY STILL HAVE
SOME RAIN REMAINING. HAVE SLOWED THAT SLIGHTLY FROM THE PREVIOUS
FORECAST. A DECREASING TREND OCCURS THROUGH THE EVENING AS WEATHER
SHIFTS EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 413 AM CDT SAT OCT 5 2013
THE LATEST MODEL CONSENSUS IS TO NOW KEEP THE DEFORMATION
ASSOCIATED WITH THE CYCLONIC MOIST FLOW WRAPPING AROUND THE LOW TO
THE WEST-NORTHWEST ON SATURDAY. THIS IS HIGHLY DEPENDENT ON THE
TRACK OF THE LOW WHICH IS A BIT FURTHER SOUTH IN THE LATEST
GUIDANCE. IN ANY CASE...CHANGES WERE MADE TO SUNDAY TO TRY AND DRY
IT OUT WITH THE RAIN SHOWERS JUST WEST OF THE AREA. ALTHOUGH THE
CONSENSUS OF THE MODELS IS TO BRING THAT BAND INTO THE FORECAST
AREA FOR MONDAY NOW...THE LATEST 05.00Z ECMWF IS MUCH MORE
PROGRESSIVE AND RAPIDLY SHIFTS THE SHOWERS EAST. HAVE A SMALL
CHANCE OF SHOWERS TO ADDRESS THAT SITUATION.
THE REMAINDER OF THE PERIOD IS DOMINATED BY DRY WEATHER UNDER
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI OCT 4 2013
BACK EDGE OF THE CONVECTION IS MAKING STEADY EASTWARD PROGRESS AND
STILL EXPECT IT TO CLEAR BOTH TAF SITES BY 08Z. UNTIL IT
DOES...IFR CONDITIONS WILL REMAIN POSSIBLE AS LOCALLY HEAVY RAIN
COULD DROP THE VISIBILITY AND POSSIBLY THE CEILINGS DOWN. ONCE THE
RAIN MOVES THROUGH...A TEMPORARY DRY SLOT WILL MOVE INTO TO ALLOW
FOR A PERIOD OF PRIMARILY VFR CONDITIONS. AS THE MAIN SURFACE LOW
STARTS TO TRACK TOWARD THE AREA SATURDAY MORNING...EXPECT TO SEE
THE OCCLUDED FRONT LIFT INTO AND THROUGH THE AREA. THE 05.00Z NAM
SUGGESTS THAT AS THIS HAPPENS...THE LOW LEVEL MOISTURE TRANSPORT
WILL INCREASE WITH THE NOSE OF THIS INTO THE AREA LONG THE
OCCLUDED FRONT. THE MAIN UPPER LEVEL SYSTEM WILL ALSO BE
APPROACHING TO PROVIDE ADDITIONAL FORCING AND EXPECTING TO SEE
ANOTHER AREA OF SHOWERS AND SOME THUNDERSTORMS DEVELOP BY MID
MORNING AND CONTINUE INTO THE EARLY AFTERNOON. CONSIDERABLE
UNCERTAINTY ON WHAT THE CEILINGS WILL DO WITH THE OCCLUDED FRONT
BUT MOST GUIDANCE SUGGEST A RETURN TO MVFR BEFORE DRIER STARTS TO
SPREAD IN FROM THE WEST TO ALLOW THE RAIN TO END AND VFR
CONDITIONS TO RETURN.
&&
.HYDROLOGY...
ISSUED AT 413 AM CDT SAT OCT 5 2013
CONCERNING THE FLASH FLOOD WATCH...WITH CURRENT CONVECTION EAST
OF THE AREA...MAIN THREAT HAS DIMINISHED. AS AFTERNOON CONVECTION
INCREASES...IT SHOULD BE AFFECTING AREAS THAT HAVE HAD LESS RAIN
OVERALL THAN THOSE WEST OF THE MISS RIVER. AREAS EAST OF THE MISS
RIVER CAN TAKE ANOTHER 1-2 INCHES...ESPECIALLY SWRN WI. THERE IS A
SMALL PROBABILITY OF LOCALIZED FLASH FLOODING TODAY IN THE CENTRAL
WI CORRIDOR IN THE PRE-FRONTAL AIR MASS WHICH WILL STILL HAVE 1.25
TO 1.75 INCH PRECIPITABLE WATER VALUES. RAIN RATES ARE EXPECTED TO
BE HIGH...PROBABLY 2 TO 3 INCH PER HOUR SHOULD CAPE DEVELOP AS
FORECAST. THE SLOW MOVEMENT OF THE FRONT DOES GIVE SOME CONCERN
FOR FLOODING SO WILL ISSUE ANOTHER HYDROLOGICAL DISCUSSION FOR
THAT AREA AND CANCEL THE FLASH FLOOD WATCH.
THERE ARE SOME RIVER RESPONSES CURRENTLY OCCURRING. MONITORING THE
ROOT RIVER BASIN AND THE UPPER IOWA RIVERS BOTH HAVE RESPONSES.
ALSO THE WHITEWATER RIVER MIDDLE FORK THAT RUNS THROUGH WHITEWATER
STATE PARK IS RISING. AT THIS TIME THESE WILL APPROACH FLOOD STAGE
BUT IT IS BELIEVED THEY WILL NOT REACH IT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BAUMGARDT
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
414 AM CDT SAT OCT 5 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM CDT SAT OCT 5 2013
MOST EFFORT THIS FORECAST SHIFT WAS PUT TOWARD GETTING THE NEXT 24
HOURS AS ACCURATE AS POSSIBLE. SCREAMING MESSAGE IS THE SLOWER
EASTWARD PROGRESSION OF THE FRONT AND INSTABILITY...MAKING FOR A
BIT HIGHER SEVERE WEATHER CHANCE IN WI TODAY.
WATER VAPOR SHOWING THE MONSTER LOW THAT BROUGHT 25-45 INCHES OF
SNOW TO SD OVER CENTRAL SD AT 08Z AND NEARLY STATIONARY. OCCLUDED
FRONT CURRENTLY POSITIONED FROM KRWF TO KCCY...WHERE THE TRIPLE
POINT IS LOCATED. THE WARM FRONT EXTENDS EAST FROM NEAR KCCY TO
THE DELLS IN WI...WITH THE SURFACE COLD FRONT RUNNING SOUTH FROM
KCCY. THIS WARM FRONT IS THE LEADING EDGE OF THE HIGHER DEWPOINT
AIR...MIDDLE 60S...AND THE ENERGY FOR THIS AFTERNOONS STORMS. THE
OVERNIGHT CONVECTION HAS NOW PASSED OFF TO THE EAST...AND WITH IT
THE FLASH FLOOD THREAT.
EVALUATING THE 04.00Z MODEL GUIDANCE...THE TREND IS SLOWER WITH
THE NORTHEAST PROGRESSION OF THE OCCLUDED/COLD FRONT. THIS ALLOWS
MORE OF THE FORECAST AREA IN WI TO BE PRE-FRONTAL AND IN THE WARM
SECTOR FOR A HIGHER PROBABILITY OF SEVERE WEATHER. AS THE DAY
PROGRESSES...QVECTOR CONVERGENCE WILL INCREASE AS A SHORTWAVE
TROUGH IN COLORADO ROTATES AROUND THE LARGER SD TROUGH AND BEGINS
ITS EASTWARD PROGRESSION. AS THE FORCING BEGINS TO INCREASE...NEAR/POST
FRONTAL SHOWERS WILL LIKELY DEVELOP MUCH LIKE SEEN ON RADAR ALONG
I-35 EARLY THIS MORNING. ALSO...BETTER UPPER LEVEL FORCING WILL
BEGIN TO WORK TOWARD THE WARM SECTOR AND WORK WITH 0-2KM THETA-E
CONVERGENCE ALONG THE FRONT. INSTABILITY IN THE WARM SECTOR WILL HIGHLY
DEPEND ON THE EXTENT OF THE SHOWERS AND CLOUDS OVER WI...HOWEVER
BECAUSE THE DEWPOINTS ARE ALREADY MIDDLE 60S...AT LEAST MARGINAL
INSTABILITY WILL BE PRESENT BY 18Z. MUCAPES AROUND 1000-1500 J/KG
LOOK TO BE A GOOD ESTIMATE ON AFTERNOON CAPE...POSSIBLY HIGHER
WITH MORE CLOUD BREAKS.
WIND SHEAR LOOKS TO INCREASE TODAY BUT RIGHT ON THE COLD/OCCLUDED
FRONTAL BOUNDARY...TO MAKE IT A MARGINAL SUPERCELL DAY WITH
MULTICELLS ALSO PRESENT. THE 05.06Z NAM AND 05.07Z RAP BOTH
SUGGEST NEAR 40 KTS OF 0-6KM SHEAR...CERTAINLY ENOUGH FOR
SUPERCELLS. THE 05.07Z RAP MIXES ALL THE PRE-FRONTAL SURFACE
WINDS TO SOUTHERLY. THE 05.06Z NAM AND LATEST HRRR RUNS ARE VERY
AGREEABLE THAT THE WARM FRONT WILL SHIFT NORTH TO ABOUT BLACK
RIVER FALLS WI TODAY...VERY CLOSE TO THE SPC DAY 1 NORTHERN EXTENT
OF THE SLIGHT RISK. EASTERLY FLOW IS FOUND NORTH OF THE WARM
FRONT...WHICH EXTENDS TO THE EAST TOWARD KGRB...SO A GOOD
CONVERGENT BOUNDARY. WHILE TORNADO PROBABILITIES DONT LOOK
HIGH...THE TRIPLE POINT AREA AND ALONG THAT WARM FRONT THIS
AFTERNOON WILL BE A FOCAL POINT. OTHERWISE...DAMAGING WIND
SEGMENTS OR LARGE HAIL ARE THE MAIN THREATS FROM THE STORMS IN WI.
NORTH OF THE WARM FRONT...LOW-LEVEL INVERTED CONDITIONS AND
ELEVATED STORMS ARE FAVORED...HEAVY RAIN IS THE MAIN THREAT...WITH AN
ISOLATED HAIL STORM POSSIBLE. THE FRONT SHOULD SHIFT EAST OF THE
FORECAST AREA BY EARLY EVENING WITH STRONG DEWPOINT DECREASES.
THUS...THE MAIN SEVERE WEATHER THREAT LOOKS TO BE ABOUT 1 PM TO 5
PM.
BY TONIGHT...THE NE AND EASTERNMOST FORECAST AREA MAY STILL HAVE
SOME RAIN REMAINING. HAVE SLOWED THAT SLIGHTLY FROM THE PREVIOUS
FORECAST. A DECREASING TREND OCCURS THROUGH THE EVENING AS WEATHER
SHIFTS EAST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 413 AM CDT SAT OCT 5 2013
THE LATEST MODEL CONSENSUS IS TO NOW KEEP THE DEFORMATION
ASSOCIATED WITH THE CYCLONIC MOIST FLOW WRAPPING AROUND THE LOW TO
THE WEST-NORTHWEST ON SATURDAY. THIS IS HIGHLY DEPENDENT ON THE
TRACK OF THE LOW WHICH IS A BIT FURTHER SOUTH IN THE LATEST
GUIDANCE. IN ANY CASE...CHANGES WERE MADE TO SUNDAY TO TRY AND DRY
IT OUT WITH THE RAIN SHOWERS JUST WEST OF THE AREA. ALTHOUGH THE
CONSENSUS OF THE MODELS IS TO BRING THAT BAND INTO THE FORECAST
AREA FOR MONDAY NOW...THE LATEST 05.00Z ECMWF IS MUCH MORE
PROGRESSIVE AND RAPIDLY SHIFTS THE SHOWERS EAST. HAVE A SMALL
CHANCE OF SHOWERS TO ADDRESS THAT SITUATION.
THE REMAINDER OF THE PERIOD IS DOMINATED BY DRY WEATHER UNDER
LARGER SCALE RIDGING AND ABOVE NORMAL TEMPERATURES.
&&
.HYDROLOGY...
ISSUED AT 413 AM CDT SAT OCT 5 2013
CONCERNING THE FLASH FLOOD WATCH...WITH CURRENT CONVECTION EAST
OF THE AREA...MAIN THREAT HAS DIMINISHED. AS AFTERNOON CONVECTION
INCREASES...IT SHOULD BE AFFECTING AREAS THAT HAVE HAD LESS RAIN
OVERALL THAN THOSE WEST OF THE MISS RIVER. AREAS EAST OF THE MISS
RIVER CAN TAKE ANOTHER 1-2 INCHES...ESPECIALLY SWRN WI. THERE IS A
SMALL PROBABILITY OF LOCALIZED FLASH FLOODING TODAY IN THE CENTRAL
WI CORRIDOR IN THE PRE-FRONTAL AIR MASS WHICH WILL STILL HAVE 1.25
TO 1.75 INCH PRECIPITABLE WATER VALUES. RAIN RATES ARE EXPECTED TO
BE HIGH...PROBABLY 2 TO 3 INCH PER HOUR SHOULD CAPE DEVELOP AS
FORECAST. THE SLOW MOVEMENT OF THE FRONT DOES GIVE SOME CONCERN
FOR FLOODING SO WILL ISSUE ANOTHER HYDROLOGICAL DISCUSSION FOR
THAT AREA AND CANCEL THE FLASH FLOOD WATCH.
THERE ARE SOME RIVER RESPONSES CURRENTLY OCCURRING. MONITORING THE
ROOT RIVER BASIN AND THE UPPER IOWA RIVERS BOTH HAVE RESPONSES.
ALSO THE WHITEWATER RIVER MIDDLE FORK THAT RUNS THROUGH WHITEWATER
STATE PARK IS RISING. AT THIS TIME THESE WILL APPROACH FLOOD STAGE
BUT IT IS BELIEVED THEY WILL NOT REACH IT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI OCT 4 2013
BACK EDGE OF THE CONVECTION IS MAKING STEADY EASTWARD PROGRESS AND
STILL EXPECT IT TO CLEAR BOTH TAF SITES BY 08Z. UNTIL IT
DOES...IFR CONDITIONS WILL REMAIN POSSIBLE AS LOCALLY HEAVY RAIN
COULD DROP THE VISIBILITY AND POSSIBLY THE CEILINGS DOWN. ONCE THE
RAIN MOVES THROUGH...A TEMPORARY DRY SLOT WILL MOVE INTO TO ALLOW
FOR A PERIOD OF PRIMARILY VFR CONDITIONS. AS THE MAIN SURFACE LOW
STARTS TO TRACK TOWARD THE AREA SATURDAY MORNING...EXPECT TO SEE
THE OCCLUDED FRONT LIFT INTO AND THROUGH THE AREA. THE 05.00Z NAM
SUGGESTS THAT AS THIS HAPPENS...THE LOW LEVEL MOISTURE TRANSPORT
WILL INCREASE WITH THE NOSE OF THIS INTO THE AREA LONG THE
OCCLUDED FRONT. THE MAIN UPPER LEVEL SYSTEM WILL ALSO BE
APPROACHING TO PROVIDE ADDITIONAL FORCING AND EXPECTING TO SEE
ANOTHER AREA OF SHOWERS AND SOME THUNDERSTORMS DEVELOP BY MID
MORNING AND CONTINUE INTO THE EARLY AFTERNOON. CONSIDERABLE
UNCERTAINTY ON WHAT THE CEILINGS WILL DO WITH THE OCCLUDED FRONT
BUT MOST GUIDANCE SUGGEST A RETURN TO MVFR BEFORE DRIER STARTS TO
SPREAD IN FROM THE WEST TO ALLOW THE RAIN TO END AND VFR
CONDITIONS TO RETURN.
&&
.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
1140 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 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CDT FRI OCT 4 2013
BACK EDGE OF THE CONVECTION IS MAKING STEADY EASTWARD PROGRESS AND
STILL EXPECT IT TO CLEAR BOTH TAF SITES BY 08Z. UNTIL IT
DOES...IFR CONDITIONS WILL REMAIN POSSIBLE AS LOCALLY HEAVY RAIN
COULD DROP THE VISIBILITY AND POSSIBLY THE CEILINGS DOWN. ONCE THE
RAIN MOVES THROUGH...A TEMPORARY DRY SLOT WILL MOVE INTO TO ALLOW
FOR A PERIOD OF PRIMARILY VFR CONDITIONS. AS THE MAIN SURFACE LOW
STARTS TO TRACK TOWARD THE AREA SATURDAY MORNING...EXPECT TO SEE
THE OCCLUDED FRONT LIFT INTO AND THROUGH THE AREA. THE 05.00Z NAM
SUGGESTS THAT AS THIS HAPPENS...THE LOW LEVEL MOISTURE TRANSPORT
WILL INCREASE WITH THE NOSE OF THIS INTO THE AREA LONG THE
OCCLUDED FRONT. THE MAIN UPPER LEVEL SYSTEM WILL ALSO BE
APPROACHING TO PROVIDE ADDITIONAL FORCING AND EXPECTING TO SEE
ANOTHER AREA OF SHOWERS AND SOME THUNDERSTORMS DEVELOP BY MID
MORNING AND CONTINUE INTO THE EARLY AFTERNOON. CONSIDERABLE
UNCERTAINTY ON WHAT THE CEILINGS WILL DO WITH THE OCCLUDED FRONT
BUT MOST GUIDANCE SUGGEST A RETURN TO MVFR BEFORE DRIER STARTS TO
SPREAD IN FROM THE WEST TO ALLOW THE RAIN TO END AND VFR
CONDITIONS TO RETURN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH UNTIL 7 AM CDT SATURDAY FOR WIZ017-029-032>034-
041>044-053.
MN...FLASH FLOOD WATCH UNTIL 7 AM CDT SATURDAY FOR MNZ079-086>088-
094>096.
IA...FLASH FLOOD WATCH UNTIL 7 AM CDT SATURDAY FOR IAZ008>011-018-019.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
430 AM EDT MON OCT 7 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TODAY AND TONIGHT...STALLING
OFF THE COAST AS COOLER HIGH PRESSURE BUILDS IN FROM THE WEST AND
NORTH. AN AREA OF LOW PRESSURE...THE REMNANTS OF KAREN...WILL MOVE
UP THE COAST ALONG THE STALLED FRONT TUESDAY AND WEDNESDAY. HIGH
PRESSURE WILL GENERALLY PREVAIL THURSDAY THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN...A DEEP MOIST PLUME OFF THE ATLC AND STRONG LOW LEVEL
MOISTURE CONVERGENCE CONTINUES TO IGNITE BATCHES OF SHOWERS FROM THE
OCEAN...ONSHORE OVER SOUTHERN SOUTH CAROLINA AND THROUGH THE
CHARLESTON QUAD-COUNTY. THERE IS 25 KT OF SHEAR IN THE 0-1KM
LAYER AND A FEW SHOWERS HAVE PRODUCED SOME BRIEFLY GUSTY WINDS AND
EVEN VERY WEAK ROTATION AT TIMES. LATEST RAP SHOWS CONTINUED
DESTABILIZATION EARLY THIS MORNING AND INCREASING UPPER DIFLUENCE.
WE WILL BE KEEPING AN EYE OUT FOR ISOLATED STRONG CELLS EMBEDDED
WITHIN THE MAIN BAND OF CONVERGENCE. IF NOTHING ELSE...WITH PWATS
NEAR 1.9 INCHES...BRIEF TORRENTIAL DOWNPOURS ARE LIKELY WITH
ACTIVITY THAT STREAMS ONSHORE. THIS COULD SPELL LOCALIZED MINOR
FLOODING ISSUES WITH SOME PONDING WATER IN SPOTS ACROSS PARTS OF
CHARLESTON AND BERKELEY COUNTIES AT TIMES.
AN EXTREMELY COMPLEX SYNOPTIC SCENE TODAY WITH A PLETHORA OF PLAYERS
OF INTEREST. BANDS OF DEEP TROPICAL MOISTURE ADVECTING IN FROM
BOTH THE ATLC AND THE GULF OF MEXICO...GULF MOISTURE RESIDUAL FROM
REMNANTS OF KAREN. LIKELY TO CATEGORICAL POPS IN ORDER TODAY WITH
GEORGIA AREAS THE MOST DIFFICULT TO PIN DOWN. IN SE GEORGIA...THE
DEEP MOISTURE WILL ARRIVE DURING THE DAY BUT MAINLY MISSING OUT ON
A GOOD BIT OF THE UPPER FORCING THIS MORNING THAT IS SHIFTING
THROUGH THE CSRA-MIDLANDS-PEE REGIONS OF GA/SC. THIS AFTERNOON
THAT REGION WILL BE BETWEEN MID LEVEL DISTURBANCES WITH MARGINAL
INSTABILITY AND NOT MUCH LOW LEVEL CONVERGENCE. THE PWATS ARE SO
ANONYMOUSLY HIGH HOWEVER...WE DID NOT DO TOO MUCH RE-ARRANGEMENT
OF OUR POP SCHEME.
IN SE SOUTH CAROLINA...CLOSER TO THE CHARLESTON AREA...IT LOOKS LIKE
A WET AND UNSETTLED A DAY. DEEP LAYERED SHEAR GENERALLY DECREASES
DURING THE DAY BIT THROUGH EARLY AFTERNOON...WE CANNOT RULE OUT AN
ISOLATED STRONG TO SEVERE TSTM BUT MOISTURE PROFILES AND FORECAST
SOUNDINGS SUGGEST THE 5 PERCENT RISK FROM THE STORM PREDICTION
CENTER IS ON TRACK FOR THE FIRST HALF OF TODAY UNTIL THE LOW LEVEL
JET PULLS OUT.
CONVECTIVE ELEMENTS ALREADY HAVE PRODUCED TORRENTIAL DOWNPOURS EAST
OF I-95 IN SOUTH CAROLINA AND SUSPECT THIS WILL REMAIN THE CASE
AHEAD OF THE COLD FRONT TODAY.
TONIGHT THE COLD FRONT BEGINS TO BACKDOOR S THROUGH THE REGION TONIGHT
AS SURFACE HIGH PRES BUILDS INTO THE MID ATLC REGION WHILE LOW PRES
SETTLES IN OVER N FLORIDA. GOOD UPPER FORCING FOR ASCENT IS PROGGED
TO DEVELOP OVER THE REGION FROM S TO N OVERNIGHT AS THE BASE OF THE
SOUTHERN LATITUDE TROUGH MOVES THROUGH S GEORGIA AND N FLORIDA. AN
EXCELLENT SETUP FOR THE START OF SOME SOAKING RAINFALL AT TIMES WHICH
WILL BE IN THE FORECAST INTO MID WEEK. WE RAISED LATE NIGHT POPS
IN SE GEORGIA TO CATEGORICAL ON THIS PACKAGE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
THE MODEL SUITE HAS CHANGED DRASTICALLY FROM WHAT WE WERE ANALYZING
24 HOURS PRIOR. A STRONGER THAN PREVIOUSLY EXPECTED SOUTHERN STREAM
VORT IS TRACKING ALONG THE WESTERN GULF COAST. THIS FEATURE WILL
INTERACT WITH THE RESIDUAL LOW FROM KAREN AS IT CROSSES FLORIDA.
MEANWHILE A LARGE AREA OF HIGH PRESSURE WILL OVERSPREAD THE EASTERN
UNITED STATES TUESDAY. AS THE REMNANT SURFACE LOW MOVES INTO THE
SOUTHWEST ATLANTIC AHEAD OF THE UPPER VORT...IT WILL DEEPEN AS IT
LIFTS SLOWLY NORTHEAST. A COLD AIR DAMMING REGIME WILL DEVELOP AND
PERSIST FROM TUESDAY THROUGH THURSDAY AS THE OFFSHORE LOW
STRENGTHENS COLD AIR ADVECTION ACROSS INLAND AREAS. CONDITIONS LOOK
RIPE FOR WIDESPREAD PRECIPITATION ON TUESDAY...ESPECIALLY SOUTHERN
SC. THE NAM SHOWS AN IMPRESSIVE COUPLED UPPER JET OVER THE REGION AT
18Z TUESDAY...PRODUCING STRONG UPPER DIVERGENCE. FAIRLY DEEP
MOISTURE WILL STREAM IN OFF THE ATLANTIC ATOP THE COOL SURFACE WEDGE
WITH PWATS AROUND 2 INCHES. STRONG LIFT WILL DEVELOP OVERHEAD
TUESDAY...WITH THE BEST LIFT SHIFTING NORTHEAST OF THE AREA TUESDAY
NIGHT. WE INCREASED POPS TO CATEGORICAL ACROSS SOUTHERN SC ON
TUESDAY WITH LIKELY POPS ELSEWHERE AND THROUGH TUESDAY NIGHT.
TEMPERATURES ON TUESDAY WILL BE A REAL SHOCK COMPARED TO TODAY.
OVERCAST SKIES...STRONG COLD ADVECTION AND EXTENSIVE PRECIP WILL
LIMIT HIGH TEMPS TO THE MID/UPPER 60S EXCEPT FOR A FEW 70S CLOSER TO
THE COAST.
THE SURFACE LOW WILL VERY SLOWLY LIFT NORTHEAST JUST OFF THE COAST
WEDNESDAY AND WEDNESDAY NIGHT. THOUGH THE BEST LIFT WILL SHIFT
NORTHEAST OF THE LOCAL FORECAST AREA...ENOUGH RESIDUAL MOISTURE AND
OVERRUNNING WILL MAINTAIN OVERCAST SKIES AND SCATTERED RAIN SHOWERS
ON WEDNESDAY. HIGH TEMPS WILL AGAIN BE WELL BELOW NORMAL DUE TO THE
AFOREMENTIONED LIMITING FACTORS. WE ARE SHOWING UPPER 60S TO LOWER
70S.
THE MOISTURE AND LIFT ASSOCIATED WITH THE COASTAL LOW WILL SHIFT
NORTHEAST OF THE AREA ON THURSDAY AS THE UPPER LOW ALSO LIFTS
NORTHEAST. CLOUDS WILL SLOWLY CLEAR OUT FROM THE SOUTHWEST AND RAIN
CHANCES WILL BE MINIMAL. TEMPERATURES SHOULD MAKE IT INTO THE MIDDLE
70S BY AFTERNOON.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
BROAD HIGH PRESSURE WILL PREVAIL DURING THE EXTENDED WITH GENERALLY
DRY WEATHER AND SEASONABLE TEMPERATURES IN THE 50S AT NIGHT AND 70S
DURING THE DAY.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
KCHS...SHOWERS AND MVFR CIGS ARE EXPECTED TO IMPACT THE TERMINAL
OCCASIONALLY THROUGH THE MORNING HOURS. SMALL CHANCES FOR IFR
CONDITIONS...THEY LIKELY WOULD BE VERY BRIEF AND NO FOG CONCERNS.
LOW CONFIDENCE ON TIMING CHANCES FOR RAIN LATER TODAY WITH A COMPLEX
SYNOPTIC SETUP AND A SEEMINGLY EXCELLENT COMBO OF DEEP MOISTURE
AND UPPER DYNAMICS. OUTSIDE OF SHOWER AREAS...WE ARE MOST LIKELY
TO BE VFR THROUGH 06Z TUE.
KSAV...LOW CONFIDENCE WITH REGARDS TO FORECASTING THE ELEMENTS
THROUGH THIS EVENING GIVEN THE TERMINALS PROXIMITY TO SEVERAL DEEP
MOISTURE SOURCES AND MODEL DISCREPANCIES WITH REGARD TO COVERAGE
AND TIMING OF RAIN. WE MAINTAINED PERSISTENCE WITH THE PREVIOUS
TAF INDICATING THE BEST CHANCES OF RAIN FROM LATE MORNING THROUGH
MID AFTERNOON BUT IT COULD BE LATER OR LESS THAN PROJECTED. CIGS
WILL MAINLY BE VFR OVERNIGHT BUT LATE NIGHT THROUGH MID MORNING
THERE IS A CHANCE FOR MVFR/IFR CIGS TO STREAM THROUGH BUT NO FOG
CONCERNS.
EXTENDED AVIATION OUTLOOK...A PROLONGED PERIOD OF MVFR/IFR CEILINGS
IS EXPECTED FROM LATE TONIGHT THROUGH THURSDAY NIGHT. PREVAILING
MVFR CEILINGS LIKELY DURING DAYTIME HOURS WITH A DROP TO IFR EACH
OVERNIGHT PERIOD. VSBYS MAY BE OCCASIONALLY REDUCED IN RAIN TUESDAY
THROUGH WEDNESDAY.
&&
.MARINE...
A SSE FLOW 15 KT TO OCCASIONALLY 15-20 KT AT TIMES HAS RAISED SEAS
TO 6 FT OUT AT BUOY 41004 BUT MAINLY 3 TO 5 FT WITHIN 20 NM OF THE
COAST...HIGHEST OFF OF CHARLESTON COUNTY. THE LOW LEVEL JET AHEAD
OF THE COLD FRONT WILL WEAKEN TODAY AS THE LOW LEVEL FRONTAL
TROUGH APPROACHES. WINDS WILL BECOMES LIGHTER THIS AFTERNOON AND
EVENING AND EVEN VARIABLE AT TIMES. SEAS WILL ALSO DIMINISH A BIT.
LATER TONIGHT...CHANGES IN THE OFFING AS N TO NE SURGING BEGINS
TO INCREASE TOWARD DAYBREAK TUESDAY IN THE WAKE OF THE COLD FRONT.
THE LATE NIGHT SURGE WILL BE MOST NOTICEABLE OFF OF THE CENTRAL
SOUTH CAROLINA COAST AND LIKELY REACH 15 KT BY DAWN. SEAS TONIGHT
2 TO 4 FT.
WINDS WILL CRANK UP FROM THE NNE TUESDAY IN RESPONSE TO THE COASTAL
LOW MOVING INTO THE SOUTHWEST ATLANTIC FROM THE GULF. THE GRADIENT
WILL BECOME PINCHED BETWEEN INLAND HIGH PRESSURE AND COASTAL LOW
PRESSURE...PRODUCING A PROLONGED STRETCH OF ENHANCED NNE WINDS.
SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY DEVELOP DURING THE DAY
TUESDAY WITH MARGINAL ADVISORY CONDITIONS CONTINUING INTO WEDNESDAY
OR LATER. SEAS WILL NOT BUILD SUBSTANTIALLY DUE TO THE OFFSHORE
FETCH BUT SOME 6 FOOTERS ARE POSSIBLE AT TIMES MAINLY BEYOND 20 NM
FROM SHORE.
WINDS WILL CONTINUE OUT OF THE N/NNE INTO THE WEEKEND BUT SPEEDS
WILL DROP OFF CONSIDERABLY BY THURSDAY AS THE SURFACE LOW LIFTS
NORTHEAST AND THE GRADIENT WEAKENS.
RIP CURRENTS...AFTER A COLD FRONT ADVANCES THROUGH THE REGION...
SUSTAINED NNE WINDS COULD CONTRIBUTE TO AN ELEVATED RIP CURRENT RISK
ON AREA BEACHES TUESDAY THROUGH THURSDAY.
&&
.TIDES/COASTAL FLOODING...
BEGINNING TUESDAY...ASTRONOMICAL HIGH TIDES COULD COMBINE WITH
PERSISTENT/ELEVATED NORTHEAST WINDS TO PRODUCE MINOR SALTWATER
INUNDATION IN LOW-LYING AREAS NEAR THE COAST AROUND THE TIMES OF THE
LATE MORNING/EARLY AFTERNOON HIGH TIDES.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE...JRL
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
145 AM EDT MON OCT 7 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA MONDAY AND WILL PUSH THROUGH THE
REGION MONDAY NIGHT INTO TUESDAY. AN UPPER LEVEL LOW PRESSURE IS
THEN EXPECTED TO SLOWLY TRACK NORTHEAST OVER THE REGION THROUGH
MIDWEEK. HIGH PRESSURE WILL EXPAND INTO THE REGION AND WILL PREVAIL
THROUGH NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A DEEP MOIST PLUME OFF THE ATLC AND STRONG LOW LEVEL MOISTURE
CONVERGENCE CONTINUES TO IGNITE BATCHES OF SHOWERS FROM THE
OCEAN...ONSHORE OVER SOUTHERN SOUTH CAROLINA AND THROUGH THE
CHARLESTON QUAD-COUNTY. THERE IS ABOUT 20 KT OF SHEAR IN THE 0-1KM
LAYER AND A FEW SHOWERS HAVE PRODUCED SOME BRIEFLY GUSTY WINDS
AND EVEN VERY WEAK ROTATION OFFSHORE. LATEST RAP SHOWS CONTINUED
DESTABILIZATION OVERNIGHT AND INCREASING UPPER DIFLUENCE. WILL
BE KEEPING AN EYE OUT FOR ISOLATED STRONG CELLS EMBEDDED WITHIN THE
MAIN BAND OF CONVERGENCE. IF NOTHING ELSE...WITH PWATS NEAR 1.9
INCHES...BRIEF TORRENTIAL DOWNPOURS ARE LIKELY WITH ACTIVITY THAT
STREAMS ONSHORE. THIS COULD SPELL MINOR FLOODING ISSUES WITH SOME
PONDING WATER IN SPOTS ACROSS PARTS OF CHARLESTON AND BERKELEY
COUNTIES AT TIMES.
WE LOWERED POPS A BIT IN THE OVERNIGHT TO THE W OF I-95 AS LATEST
MODELS SHOW A VOID AREA BETWEEN THE CONVECTION OVER N GEORGIA AND
THE SOUTH CAROLINA UPSTATE AND THE MASS OF CONVECTION ASSOCIATED
WITH THE EX-TROPICAL LOW IN THE NE GULF OF MEXICO.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
AHEAD OF AN APPROACHING COLD FRONT...AN AXIS OF DEEP LAYER MOISTURE
AND FORCING FOR ASCENT SUPPORTED IN PART BY UPPER JET DIVERGENCE
WILL ALREADY BE ADVANCING IN TO THE FORECAST AREA MONDAY MORNING AND
WILL GRADUALLY ADVANCE THROUGH THE REGION DURING THE DAY. THIS
SCENARIO WILL SUPPORT MOST/ALL LOCATIONS SHOULD RECEIVE MEASURABLE
RAINFALL. 12Z GUIDANCE CONTINUES TO JUSTIFY ONGOING CATEGORICAL
POPS. PWATS AROUND 2 INCHES COULD SUPPORT LOCALLY HEAVY RAINFALL.
ALSO...CANNOT RULE OUT AN ISOLATED SEVERE THUNDERSTORM WITH DAMAGING
WET MICROBURSTS. HOWEVER...CLOUD COVER/PRECIPITATION WILL LIMIT
WARMING/DESTABILIZATION...AND THE AXIS OF STRONGEST WIND SHEAR WILL
REMAIN WELL NORTH OF THE REGION...SO THE POTENTIAL FOR SEVERE
WEATHER APPEARS QUITE LOW.
BY MONDAY EVENING...THE AXIS OF DEEPEST MOISTURE WILL SHIFT INTO
COASTAL COUNTIES AN/OR ADJACENT COASTAL WATERS...AND THE SURFACE
COLD FRONT WILL PRESS THROUGH THE FORECAST AREA FROM NORTH TO SOUTH
OVERNIGHT INTO TUESDAY MORNING. MEANWHILE...A SHORTWAVE TROUGH NOTED
ON WATER VAPOR IMAGERY ADVANCING THROUGH EAST TX WILL DIG INTO THE
NORTHERN GULF OF MEXICO THEN WILL SWING TOWARD THE SOUTHEAST COAST
MONDAY NIGHT THROUGH TUESDAY. IN RESPONSE TO FORCING FOR ASCENT IN
ADVANCE OF THIS FEATURE...THE POST FROPA DRYING TREND WILL CEASE
AND DEEP LAYER MOISTURE WILL LIKELY EXPAND TOWARD THE N/W INTO THE
FORECAST AREA. AS A RESULT...BUMPED MONDAY NIGHT POPS UP A BIT FROM
THE PREVIOUS FORECAST...THEN RAISED POPS SIGNIFICANTLY ACROSS THE
FORECAST AREA TUESDAY. AS OF THE SUNDAY AFTERNOON FORECAST
PACKAGE...CAPPED MAX POPS AT HIGH CHANCE TUESDAY...BUT HIGHER POPS
COULD EVENTUALLY BE REQUIRED.
MEANWHILE...A WEDGE OF COOL/MOIST ARE WILL OVERSPREAD THE FORECAST
AREA TUESDAY...AND TEMPERATURES WILL LIKELY NOT RECOVER BEYOND THE
LOWER TO MID 70S MOST AREAS. IN FACT...IF/WHERE PRECIPITATION
BECOMES MORE WIDESPREAD THAN CURRENTLY FORECAST...TEMPERATURES COULD
REMAIN IN THE 60S ACROSS SOME N/W COUNTIES.
THE UPPER LOW IS PROGGED TO ONLY SLOWLY ROLL NE ALONG THE SE COAST
TUESDAY NIGHT THROUGH WEDNESDAY...THUS AT LEAST SLIGHT CHANCE/CHANCE
POPS ARE JUSTIFIED THROUGH THE PERIOD.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
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 /06Z MONDAY THROUGH FRIDAY/...
KCHS...SHOWERS AND MVFR CIGS ARE EXPECTED TO IMPACT THE TERMINAL
OCCASIONALLY THROUGH THE MORNING HOURS. SMALL CHANCES FOR IFR
CONDITIONS...THEY LIKELY WOULD BE VERY BRIEF AND NO FOG CONCERNS.
LOW CONFIDENCE ON TIMING CHANCES FOR RAIN LATER TODAY WITH A COMPLEX
SYNOPTIC SETUP AND A SEEMINGLY EXCELLENT COMBO OF DEEP MOISTURE
AND UPPER DYNAMICS. OUTSIDE OF SHOWER AREAS...WE ARE MOST LIKELY
TO BE VFR THROUGH 06Z TUE.
KSAV...LOW CONFIDENCE WITH REGARDS TO FORECASTING THE ELEMENTS
THROUGH THIS EVENING GIVEN THE TERMINALS PROXIMITY TO SEVERAL DEEP
MOISTURE SOURCES AND MODEL DISCREPANCIES WITH REGARD TO COVERAGE
AND TIMING OF RAIN. WE MAINTAINED PERSISTENCE WITH THE PREVIOUS
TAF INDICATING THE BEST CHANCES OF RAIN FROM LATE MORNING THROUGH
MID AFTERNOON BUT IT COULD BE LATER OR LESS THAN PROJECTED. CIGS
WILL MAINLY BE VFR OVERNIGHT BUT LATE NIGHT THROUGH MID MORNING
THERE IS A CHANCE FOR MVFR/IFR CIGS TO STREAM THROUGH BUT NO FOG
CONCERNS.
EXTENDED AVIATION OUTLOOK...OCCASIONAL FLIGHT RESTRICTIONS ARE
EXPECTED MONDAY AFTERNOON/NIGHT DUE TO MOISTURE/SHOWERS ALONG A
COLD FRONT. THE PROBABILITY FOR FLIGHT RESTRICTIONS...MAINLY IN
LOW CEILINGS...HAS INCREASED IN THE WAKE OF COLD FROPA TUESDAY
INTO WEDNESDAY.
&&
.MARINE...
OVERNIGHT...CONDITIONS ACROSS THE LOCAL WATERS WILL STEADILY WORSEN AS
WINDS/SEAS INCREASE. AS THE APPROACHING COLD FRONT DRAWS
CLOSER...THE PRESSURE GRADIENT WILL TIGHTEN AND RESULT IN
STRENGTHENING SOUTHERLY FLOW. 15-20 KT WINDS WILL BE WIDESPREAD AND
SHOULD REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS THANKS TO THE
WARM ADVECTION REGIME LIMITING GUST POTENTIAL. SEAS WILL
CORRESPONDINGLY RISE AS WELL BY LATE TONIGHT...BECOMING 3-5 FT
WITHIN 20 NM AND A SOLID 5 FT BEYOND.
AHEAD OF AN APPROACHING COLD FRONT...EXPECT ELEVATED SOUTHERLY
WINDS/SEAS MONDAY. 06/12Z GUIDANCE SUGGESTS THAT WINDS CAPPED AT 20
KT AND SEAS CAPPED AT 5 FT...JUST BELOW SMALL CRAFT ADVISORY
LEVELS...WILL SUFFICE. WITHIN THE FRONTAL TROUGH MONDAY NIGHT...A
WEAK PRESSURE GRADIENT AND LIGHT/VARIABLE WINDS COULD PREVAIL FOR
SEVERAL HOURS. THEN...A STRONG COLD FRONT WILL PUSH THROUGH THE
WATERS FROM NORTH TO SOUTH LATE MONDAY NIGHT INTO TUESDAY. IN THE
WAKE OF COLD FROPA...NORTH/NORTHEAST WINDS WILL SURGE INTO THE
WATERS. 06/12Z GUIDANCE STRONGLY SUGGESTS THAT THE TIGHTENING
SURFACE PRESSURE GRADIENT AND DEEPENING MARINE LAYER MIXING PRODUCED
BY COLD AIR ADVECTION WILL SUPPORT SMALL CRAFT ADVISORY WINDS/SEAS
MOST AREAS TUESDAY INTO WEDNESDAY AND PERHAPS INTO LATE WEEK AS
ELEVATED SEAS PERSIST BEYOND 20 NM. IN FACT...THERE IS A LOW
PROBABILITY FOR THE GRADIENT TO TIGHTEN SUFFICIENTLY BETWEEN LOW
PRESSURE SOUTH/SOUTHEAST OF THE WATERS AND HIGH PRESSURE TO THE
NORTH TO SUPPORT GALE FORCE GUSTS ESPECIALLY OVER GA WATERS
TUESDAY/TUESDAY NIGHT.
RIP CURRENTS...AFTER A COLD FRONT ADVANCES THROUGH THE
REGION...SUSTAINED NE WINDS COULD CONTRIBUTE TO AN ELEVATED RIP
CURRENT RISK ON AREA BEACHES TUESDAY THROUGH LATE WEEK.
&&
.TIDES/COASTAL FLOODING...
BEGINNING TUESDAY...ASTRONOMICAL HIGH TIDES COULD COMBINE WITH
PERSISTENT/ELEVATED NORTHEAST WINDS TO PRODUCE MINOR SALTWATER
INUNDATION IN LOW-LYING AREAS NEAR THE COAST AROUND THE TIMES OF THE
LATE MORNING/EARLY AFTERNOON HIGH TIDES THIS WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...SPR
LONG TERM...JRL
AVIATION...
MARINE....
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
125 AM EDT MON OCT 7 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 409 PM EDT SUN OCT 6 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE OVER THE WRN CONUS AND
A TROUGH FROM HUDSON BAY INTO NRN ONTARIO. THE PERSISTENT MID/UPPER
LEVEL LOW HAD EDGED EASTWARD INTO ERN IA. AT THE SFC...LOW PRES WAS
LOCATED OVER S CNTRL LAKE SUPERIOR WITH A COLD FRONT INTO CNTRL
LOWER MI AND A TROUGH TO THE SW INTO SE MN. RAIN ASSOCIATED WITH A
WEAK SHORTWAVE IN THE WARM CONVEYOR AHEAD OF THE COLD FRONT WAS
LIFTING NNE THROUGH ERN CWA. OTHERWISE...RADAR INDICATED ONLY VERY
WEAK RETURNS OVER THE WEST WITH SOME SPRINKLES OR DRIZZLE. FARTHER
WEST...A NARROW BAND OF RAIN TO NEAR DLH WAS ASSOCIATED WITH THE MID
LEVEL DEFORMATION/FGEN BAND/TROWAL ON THE NRN FLANK OF THE MID LEVEL
LOW. VIS LOOP SHOWED CLEARING OVER SRN UPPER MI WITH THE ADVANCING
DRY SLOT.
TONIGHT...MODELS SUGGEST THAT THE NE MN RAIN BAND WILL CONTINUE TO
SLOWLY SPREAD INTO WEST UPPER MI THIS EVENING AND GRADUALLY SHRINK
OVERNIGHT...PER FCST 310KE SURFACE. THERE MAY ALSO BE A FEW LIGHT
SHOWERS THROUGH CNTRL UPPER MI THIS EVENING AS THE DRY SLOT AREA
GIVES WAY TO INCREASING CLOUDS WITH INCREASING 700-300 MB QVECTOR
CONV AND LOW LEVEL CONV NEAR THE TROUGH. IN ADDITION...SOME LAKE
ENHANCED SHOWERS MAY DEVELOP OVERNIGHT AS 850 MB TEMPS DROP TO AROUND
1C WITH NNW LOW CYCLONIC FLOW INCREASING. SO...CHANCE POPS WERE
MAINTAINED OVER MOST OF THE CWA TONIGHT EVEN IF ONLY INTERMITTENT
PERIODS OF RAIN DEVELOP.
MONDAY...THE REMAINING SYNOPTIC AND LAKE ENHANCED PCPN OVER THE EAST
IS EXPECTED TO DIMINISH DURING THE MORNING AS THE MID LEVEL QVECTOR
CONV FORCING AND DEEPER MOISTURE DEPART TO THE EAST.
OTHERWISE...GRADUAL CLEARING AND SOME SUNSHINE DURING THE AFTERNOON
WILL BRING TEMPS AGAIN TO NEAR SEASONAL NORMALS IN THE UPPER 50S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 409 PM EDT SUN OCT 6 2013
QUIETER WEATHER WILL REPLACE THE UNSETTLED ACTIVITY OF THIS PAST
WEEK STARTING MONDAY NIGHT. A 500MB RIDGE BUILDS ACROSS THE NORTHERN
PLAINS BY 00Z TUESDAY...AND CONTINUES EASTWARD THROUGHOUT THE
FORECAST PERIOD. SURFACE HIGH PRESSURE EXPANDS INTO THE GREAT LAKES
DURING THE DAY TUESDAY...AND GRADUALLY CENTERS ITSELF OVER THE LOWER
LAKES THROUGH FRIDAY AFTERNOON. THE ECMWF/GFS HAVE 925 MB TEMPS UP
TO 14-15C FOR WEDNESDAY-FRIDAY AFTERNOON OUT WEST...WHICH PUTS HIGHS
ROUGHLY IN THE UPPER 60S/NEAR 70. FOR THE REST OF THE AREA...EXPECT
LOW TO MID 60S. BUMPED UP WINDS FOR TUESDAY AND WEDNESDAY TO ACCOUNT
FOR TIGHTENING PRESSURE GRADIENT ACROSS UPPER MICHIGAN ASSOCIATED
WITH THE SURFACE LOW MOVING JUST NORTH OF LAKE SUPERIOR AND HIGH
PRESSURE CENTERED OVER THE LOWER GREAT LAKES. THOUGH SOUTHERLY WINDS
MAY GUST UP TO 20 KTS AND TEMPS WILL BE CLOSE TO 70...AFTERNOON RH
WILL BE IN THE 35-40 PERCENT RANGE SO DO NOT EXPECT ANY FIRE WX
CONCERNS.
FRIDAY NIGHT INTO SUNDAY...A NEGATIVELY TILTED 500MB
TROUGH/POSSIBLE CUT OFF LOW WILL DIVE INTO THE PLAINS. THIS WILL
PROVIDE THE NEXT CHANCES FOR PRECIPITATION ACROSS UPPER MICHIGAN.
RECENT MODEL RUNS HAVE THE SFC LOW PRESSURE SYSTEM MOVING NORTHEAST
INTO HUDSON BAY BY SUNDAY MORNING...BRINGING A COLD FRONT ACROSS
UPPER MI. BOTH THE GFS/ECMWF HAVE THIS...THOUGH THERE ARE
DIFFERENCES IN TIMING...WITH THE GFS BRINGING THE FRONT THROUGH
FRIDAY NIGHT AND THE ECMWF BRINGING IT THROUGH SATURDAY AFTERNOON.
EVEN MORE SIGNIFICANT DIFFERENCES BETWEEN THE GFS/ECMWF SHOW UP ON
SUNDAY AS ANOTHER TROUGH APPROACHES FROM THE WEST. THE GFS BRINGS
SATURDAYS FRONT OUT OF UPPER MICHIGAN BY 12Z SUNDAY...AND THE DRY
SLOT MOVES IN OVERHEAD WHICH ENDS PRECIPITATION. BY 00Z MONDAY IT
HAS A SHORTWAVE SLIDING INTO THE DAKOTAS AND PRECIPITATION MOVING
INTO WESTERN LAKE SUPERIOR OUT AHEAD OF IT. THE ECMWF KEEPS A
STRONGER RIDGE OVER THE LOWER LAKES AND NEW ENGLAND STATES FOR
SATURDAY AND SUNDAY...SO THE PROGRESSION OF THE FRONT ON SATURDAY IS
SLOWER THAN THE GFS...AND IT STALLS OUT OVER CENTRAL/EASTERN UPPER
MICHIGAN FOR SUNDAY. OVERALL...GENERAL CHANCE-SLIGHT CHANCE POPS ARE
IN THE FORECAST FOR THESE DAYS. IT SEEMS BOTH MODELS HAVE BEEN
FAIRLY INCONSISTENT FROM RUN TO RUN ON THE WEEKEND SOLUTION...SO
WILL NOT GET CUTE WITH TIMING UNTIL THINGS IRON THEMSELVES OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 125 AM EDT MON OCT 7 2013
WITH LOW PRES CONTINUING TO EXIT TO THE E OF LAKE SUPERIOR...DRIER
AIR/CLEARING IS MAKING STEADY PROGRESS ACROSS WRN LAKE SUPERIOR PER
SATELLITE IMAGERY. KIWD SHOULD REMAIN VFR FOR THE REMAINDER OF THE
NIGHT. AT KCMX...STRATOCU SHOULD SCATTER OUT...RESULTING IN MVFR
CONDITIONS BECOMING VFR OVER THE NEXT FEW HRS. MVFR CIGS WILL LIKELY
RETURN AT KIWD/KCMX FOR A TIME THIS MORNING INTO EARLY AFTN AS
DAYTIME HEATING GENERATES STRATOCU. CONDITIONS WILL THEN BECOME VFR
IN THE EARLY/MID AFTN AS DRIER AIR ARRIVES. AT KSAW...DRIER AIR WILL
BE SLOWER TO ARRIVE AND MAY RESULT IN MVFR CIGS LINGERING THRU EARLY
AFTN. VFR CONDITIONS WILL THEN PREVAIL THRU THE REMAINDER OF THE
FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT SUN OCT 6 2013
NNW WINDS AT 20 TO 30 KNOTS ARE EXPECTED TO DEVELOP LATE TONIGHT
INTO MONDAY AS THE LOW PRES TROUGH OVER THE UPPER LAKES MOVES OFF TO
THE EAST AND THE GRADIENT TIGHTENS ACROSS THE AREA. A HIGH PRESSURE
RIDGE WILL THEN BUILD EAST INTO THE UPPER GREAT LAKES FOR MONDAY
NIGHT WITH WINDS DROPPING BELOW 25KTS. AT THIS HIGH SHIFTS EAST ON
WEDNESDAY...SOUTHERLY FLOW WILL DEVELOP OVER THE UPPER GREAT LAKES AS
A LOW PRESSURE SYSTEM MOVES THROUGH CENTRAL CANADA. AT THIS
TIME...THE SOUTHERLY FLOW LOOKS TO STAY BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
1232 AM CDT MON OCT 7 2013
.UPDATE...
ISSUED AT 1017 PM CDT SUN OCT 6 2013
SOME PATCHY RADIATIONAL FOG HAS DEVELOPED OVER THE ARROWHEAD OF
MINNESOTA. DEWPOINT DEPRESSIONS AROUND SUNSET WERE LESS THAN 10
DEGREES FOR MOST OF THE FORECAST AREA...EXCEPT FOR THE FAR
NORTHWEST COUNTIES. THEN...AS OF 9PM SOME DRIER AIR HAD FILTERED
IN FROM THE NORTHWEST AND THE BETTER DEWPOINT DEPRESSIONS REMAIN
IN THE SAME AREAS. HAVE PUT IN PATCHY TO AREAS OF FOG INTO THE
GRIDS FOR THE REST OF THE NIGHT FOR A FAIRLY LARGE PORTION OF THE
FORECAST AREA...AND AM ALSO IN THE PROCESS OF UPDATING TERMINAL
FORECASTS AS WELL.
UPDATE ISSUED AT 641 PM CDT SUN OCT 6 2013
SOME MINOR ADJUSMENTS TO EVENING FORECAST...MAINLY FOR CLOUD
TRENDS AND TEMPERATURES FOR THE NEXT FEW HOURS. HAVE SOME CONCERNS
FOR THE RECENT RAINFALL SETTING UP GOOD PRECONDITIONS FOR
FOG...WITH PLENTY OF LOW LEVEL MOISTURE AND LIGHT NORTHWEST WINDS.
CURRENTLY GUIDANCE INDICATES NO FOG IS LIKELY TO FORM. EXPERIENCE
BEGS TO DIFFER. FOR NOW WILL MONITOR LOW LEVEL MOISTURE
PARAMETERS AND WINDS...AND RE-EVALUATE HERE BEFORE 10 PM.
ALSO UPDATED AVIATION SECTION BELOW.
&&
.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 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1232 AM CDT MON OCT 7 2013
A FEW TERMINALS HAVE DEVELOPED SOME FOG THIS EVENING WITH LIGHT
WINDS...RECENT RAINFALL BOOSTING LOW LEVEL MOISTURE AND RISING
PRESSURES. EXPECT FOG TO EVENTUALLY AFFECT ALL 5 TERMINALS.
KHYR...KHIB ARE LIKELY TO HAVE THE WORST CONDITIONS WITH LIFR
VSBYS AND CIGS FOR AT LEAST A FEW HOURS. BETTER CONDITIONS
ELSEWHERE...BUT AT LEAST A SHORT PERIOD OF IFR VSBYS ARE POSSIBLE.
ONCE FOG CLEARS BY 15Z MONDAY MORNING...EXPECT VFR CONDITIONS FOR
THE REST OF THE TAF PERIOD WITH LIGHT NORTHWEST WINDS TURNING
SOUTH AFTER 00Z...STILL LESS THAN 8KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 42 67 48 66 / 0 0 0 0
INL 41 69 46 67 / 0 0 10 10
BRD 44 72 50 70 / 0 0 0 0
HYR 39 70 48 70 / 0 0 0 0
ASX 43 70 50 69 / 0 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...MELDE
LONG TERM...GRANING
AVIATION...LE
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1104 PM MDT Sun Oct 6 2013
...UPDATE TO AVIATION...
FOR THE 06Z TAF.
VFR conditions will prevail at all terminals through the effective
period. Gusts have subsided for now but will begin to increase
again late Monday morning. Gusts will once again be strongest over
north-central MT through the late evening hours. Gusts will
subside near 00z. A surface cold front will push across the region
late in the effective period with west/northwest winds increasing
for a few hours behind the front. Foltz
.PREV DISCUSSION...
/ISSUED 900 PM MDT Sun Oct 6 2013/
Have made minor adjustments to the sky and wind grids and will issue
an update this evening. Surface winds have decreased over the plains
and have adjusted accordingly. The RUC continues to indicate a
tightening of the surface gradient after 07z and HRRR analysis also
supports mid level winds strengthening around this time along the
Northern Rocky Mountain Front. This gives some corroboration for
the high wind warning that goes in effect for this area at 09z. A
chinook arch remains in place adjacent to the northern front range
and have adjusted sky grids to better define its location.
Temperatures look reasonable. Emanuel
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 48 70 42 53 / 0 0 0 10
CTB 46 67 40 53 / 0 0 10 20
HLN 36 68 39 53 / 0 10 10 20
BZN 30 67 36 54 / 0 0 0 20
WEY 24 56 31 47 / 0 0 0 20
DLN 33 63 33 49 / 0 0 10 20
HVR 40 74 41 60 / 0 0 0 10
LWT 37 71 37 53 / 0 0 0 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING from 3 AM Monday to 6 AM MDT Tuesday Northern
Rocky Mountain Front.
&&
$$
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
333 AM EDT MON OCT 7 2013
.SYNOPSIS...
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY AHEAD OF A
STRONG COLD FRONT WHICH WILL CROSS LATE TONIGHT. A WAVE OF LOW
PRESSURE WILL DEVELOP ALONG THIS FRONT AND MOVE NEAR THE AREA
TUESDAY AND WEDNESDAY...PRODUCING WIDESPREAD RAIN AND MUCH COOLER
TEMPERATURES. A DRYING AND WARMING TREND WILL BEGIN LATE IN THE
WEEK AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM MONDAY...A STREAM OF SHOWERS ORIGINATING FROM THE GULF
STREAM WATERS OFF THE GA/FL COAST CONTINUES TO MOVE NORTH INTO
EASTERN SC EARLY THIS MORNING. SYNOPTIC MODELS 24 HOURS AGO WERE NOT
ABLE TO CAPTURE THIS FEATURE...BUT RECENT HIGH-RESOLUTION MODELS
LIKE THE HRRR AND NSSL WRF SEE IT WELL AND INDICATE THE "STREAMER"
WILL CONTINUE THROUGH THE MORNING HOURS WITH SIGNIFICANT RAINFALL
TOTALS POSSIBLE ACROSS EASTERN SOUTH CAROLINA.
STRONG UPPER LEVEL LOW PRESSURE ACROSS THE SOUTHERN GREAT LAKES IS
THE SAME SYSTEM RESPONSIBLE FOR THE RECORD-BREAKING EARLY SNOW
ACROSS WESTERN SOUTH DAKOTA A COUPLE DAYS AGO. THIS UPPER SYSTEM
WILL LIFT NORTHEAST...WHILE A VORTICITY MAXIMUM AT THE BASE OF THE
UPPER TROUGH ALONG THE GULF COAST SLOWS AND BEGINS TO FORM A CLOSED
LOW LATE TONIGHT. THE SURFACE PATTERN MIRRORS THE 500 MB CHART WITH
AN EASTWARD-MOVING COLD FRONT LOCATED JUST AHEAD OF THE UPPER
TROUGH. THIS FRONT WILL SLOW ITS PROGRESS AS SURFACE LOW PRESSURES
DEVELOPS IN IN THE FLORIDA PANHANDLE.
SHOWER AND T-STORM CHANCES ARE VERY HIGH TODAY...PROBABLY AT LEAST
90 PERCENT COVERAGE ACROSS THE EASTERN CAROLINAS. THIS MORNING`S
HEAVY BAND OF SHOWERS ACROSS EASTERN SOUTH CAROLINA SHOULD SOAK THE
PEE DEE AND INTERSTATE 95 CORRIDOR THROUGH MID-MORNING...SHIFTING
EAST FROM MYRTLE BEACH THROUGH WHITEVILLE AND ELIZABETHTOWN BY
NOON...THEN FINALLY REACHING THE CAPE FEAR AREA INCLUDING WILMINGTON
BY THE MID-AFTERNOON HOURS. FROM A BROAD-SCALE PERSPECTIVE MANY
AREAS SHOULD SEE TWO-THIRDS TO ONE INCH OF RAIN TODAY...BUT WITH
TRAINING CONVECTION UNDOUBTEDLY A FEW SPOTS WILL RECEIVE 2-3 INCHES
OR MORE. SEVERE WEATHER POTENTIAL IS NOT ZERO...BUT IS LESS THAN
EXPECTED YESTERDAY DUE TO WEAKENING LOW-LEVEL WIND FIELDS AND
OVERALL MODEST INSTABILITY. IN FACT IT APPEARS ISOLATED FLOODING MAY
BECOME A LARGER FACTOR TO CONTEND WITH THAN SEVERE WEATHER. SHOULD A
THUNDERSTORM BECOME SEVERE TODAY...WET MICROBURSTS APPEAR TO BE THE
MOST SIGNIFICANT THREAT.
TONIGHT THE PRESSURE GRADIENT BETWEEN THE LOW OVER NORTHERN FLORIDA
AND HIGH PRESSURE STRENGTHENING OVER PENNSYLVANIA SHOULD PRODUCE A
NORTHERLY SURGE THAT WILL REACH OUR AREA A FEW HOURS BEFORE SUNRISE.
THIS SHALLOW COLD AIRMASS WILL UNDERCUT THE OTHERWISE WARM AND HUMID
AIR PRESENT...PRODUCING GUSTY WINDS AND SUDDENLY FALLING
TEMPERATURES. PRECIPITATION CHANCES WILL CONTINUE AS WELL...
ESPECIALLY ALONG THE COAST...BUT ISENTROPIC PROCESSES WILL BECOME
MORE DOMINANT WITH TIME AS INSTABILITY WANES AND VEERING LOW LEVEL
WINDS ADVECT ATLANTIC MOISTURE BACK ONSHORE. POPS TONIGHT RANGE FROM
80 PERCENT ALONG THE COAST TO 60 PERCENT IN FLORENCE AND DARLINGTON.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...SLOW MOVING UPPER LOW WILL EJECT OUT OF THE
GULF OF MEXICO AND DRIFT NORTHEAST THROUGH THE PERIOD...SPAWNING A
WAVE OF LOW PRESSURE ALONG A COLD FRONT STALLED ON THE COAST.
STRONG VORT MAX ACROSS SOUTHEAST TEXAS WILL MOVE INTO THE GULF AND
THEN DRIFT NORTHEAST OVERHEAD THE CAROLINAS TUESDAY AND WEDNESDAY.
THIS SPAWNS A SURFACE WAVE ALONG A COLD FRONT WHICH WILL BE STALLED
RIGHT ON THE COAST...AND WILL KEEP UNSETTLED WEATHER THROUGH THE
PERIOD. GUIDANCE IS IN GOOD AGREEMENT THAT BOTH TUESDAY AND
WEDNESDAY WILL BE WET...A SIGNIFICANT CHANGE FROM MODELS LAST NIGHT.
AS THE FRONT STALLS JUST OFFSHORE...ABUNDANT TROPICAL MOISTURE
REMAINS IN PLACE. THIS SERVES AS THE FUEL FOR PERIODS OF MDT/HVY
RAIN TUE AND WED AS THE UPPER LOW MOVES OVERHEAD.
ADDITIONALLY...ISENTROPIC LIFT OVER THE DEVELOPING WEDGE-HIGH
PRESSURE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS EASTERN PORTIONS
OF THE CWA. WPC IS SHOWING WIDESPREAD 1-2 INCHES OF QPF...MOST
ACROSS THE CAPE FEAR REGION TUE/WED. THIS MAY BE A BIT HIGH...BUT
CERTAINLY SHOWS THE POTENTIAL WITHIN THE TROPICAL MOISTURE PLUME.
IN ADDITION TO THE UNSETTLED WEATHER...TEMPS WILL BE WELL BELOW
NORMAL BOTH TUE AND WED THANKS TO THE WEDGE HIGH PRESSURE AND
CLOUDS/RAIN.
STRONG LOW LVL CAA DEVELOPS EARLY TUESDAY...AND HAVE
SHOWN AN ATYPICAL DIURNAL CURVE WITH MAX TEMPS BEING REACHED FIRST
THING TUESDAY MORNING...BEFORE FALLING THROUGH THE DAY. HIGHS ON
TUESDAY WILL REACH ONLY THE MID/UPR 60S...AGAIN...EARLY IN THE
DAY...AND THEN FALL INTO THE LOW 60S/UPR 50S BY EVE. THIS COMBINES
WITH STRONG NE WINDS WHICH MAY GUST TO 30 MPH...AND TUESDAY WILL
FEEL MORE LIKE NOVEMBER IN SEATTLE THAN OCTOBER IN WILMINGTON! LOWS
TUESDAY NIGHT WILL SHOW VERY LITTLE DIURNAL RANGE...DROPPING ONLY
INTO THE MID 50S INLAND...AROUND 60 AT THE COAST.
LITTLE IMPROVEMENT WEDNESDAY...BUT ANY IMPROVEMENT WILL BE WELCOMED
AFTER TUESDAY! CLOUDS AND RAIN PERSISTING WILL AGAIN LIMIT WARMING
IN THE WEDGE SETUP...AND HIGHS WILL PEAK IN THE UPR 60S INLAND...LOW
70S NEAR THE COAST. LOWS WED NIGHT WILL BE SIMILAR TO TUESDAY
NIGHT...UPR 50S TO LOW 60S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...ONE MORE UNSETTLED DAY THURSDAY AS VERY SLOW
MOVING UPPER LOW AND SURFACE WAVE WILL FINALLY MOVE OFF TO THE
NORTHEAST AND ALLOW FOR DRYING ACROSS THE AREA. GUIDANCE IN
DISAGREEMENT AS TO HOW LONG IT WILL TAKE FOR DRYING TO OCCUR...BUT
WITH UPPER LOW EMBEDDED WITHIN THE 5H RIDGE...THUS MOVING VERY
SLOWLY...WILL LEAN ON THE SLOWER SOLUTION AND KEEP SCHC POP ACROSS
NE ZONES EARLY THURSDAY BEFORE THE ENTIRE AREA DRIES OUT. BEYOND
THURSDAY...HEIGHTS GRADUALLY RISE AND THE WEDGE SLOWLY BREAKS
DOWN...ALLOWING FOR MUCH MORE SUNSHINE AND TEMPS WARMING BACK
TOWARDS CLIMO OR ABOVE BY THE WKND.
GFS/EURO/CMC STILL DEPICT A SECONDARY AREA OF LOW PRESSURE
DEVELOPING WELL OFFSHORE AND THEN RETROGRADING BACK TO THE SW
SAT/SUN TOWARDS THE COAST. WHILE THIS HAS BEEN A PERSISTENT FEATURE
IN THE EXTENDED GUIDANCE...LITTLE AGREEMENT IN SPECIFIC PLACEMENT
AND WHETHER ANY IMPACTS WILL BE FELT LOCALLY. WILL KEEP INHERITED
SILENT POP FOR D6/D7 WITH TEMPS RIGHT AROUND NORMAL FOR MID-OCTOBER.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...BAND OF SHOWERS EMANATING FROM THE ATLANTIC OCEAN NEAR
CHARLESTON WILL AFFECT FLORENCE AND LUMBERTON EARLY THIS MORNING.
THE BIGGEST THREAT WILL BE TRANSIENT LOW CEILINGS NEAR MODERATE
RAINFALL. AT FLORENCE THERE IS A MODERATE CHANCE OF SUB-1000 FOOT
CEILINGS THROUGH 09Z...WITH LOW PROBABILITIES OF IFR CIGS THROUGH
DAYBREAK. AT LUMBERTON IFR PROBABILITIES ARE LOWER BUT CANNOT
TOTALLY BE RULED OUT. FOR THE COASTAL AIRPORTS (ILM, MYR, CRE) THE
BULK OF THE SHOWER ACTIVITY OVER THE NEXT 6 HOURS SHOULD REMAIN TO
THE WEST...WITH GENERALLY VFR TO OCCASIONAL MVFR CONDITIONS
EXPECTED.
AN APPROACHING COLD FRONT WILL BRING SHRA TO OUR FORECAST AREA LATER
TODAY. VFR/MVFR CONDITIONS SHOULD PREVAIL...WITH TEMPO PERIODS OF
IFR VSBYS IN HEAVIER SHOWERS. FCST SOUNDINGS SUGGEST THERE WILL BE
ENOUGH INSTABILITY FOR AT LEAST ISOLATED T-STORMS...SO HAVE INCLUDED
VCTS FOR ALL TERMS DURING THE DAYTIME. SOUTHERLY FLOW WILL PERSIST
FOR MUCH OF THE DAY WITH WINDS AROUND 10 KTS. THE FRONT WILL PASS
THROUGH KFLO/KLBT AROUND 00Z TUESDAY...WITH WINDS BECOMING NORTHEAST
AROUND 5 KTS FOLLOWING FROPA. BY 06Z TUESDAY...THE FRONT SHOULD BE
NEAR THE COAST OR JUST OFFSHORE. WILL HOLD ONTO VCSH AT ALL TERMS
THROUGH THE END OF THE TAF PERIOD AS DEEP MOISTURE LINGERS OVER OUR
AREA.
EXTENDED OUTLOOK...SCATTERED SHOWERS WITH MVFR CIGS ON TUESDAY AS
THE FRONT LINGERS OFFSHORE. MVFR/IFR CIGS AND ISOLATED SHOWERS
POSSIBLE ON WEDNESDAY MORNING...BECOMING VFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM MONDAY...A NORTH-TO-SOUTH ORIENTED COLD FRONT JUST
ENTERING THE APPALACHIANS WILL MOVE EASTWARD TODAY...DECELERATING AS
IT APPROACHES THE COAST TONIGHT. SOUTH-SOUTHEAST WINDS 15-20 KNOTS
THIS MORNING SHOULD DIMINISH THIS AFTERNOON. LOW PRESSURE DEVELOPING
ALONG THE FRONT NEAR THE FLORIDA PANHANDLE WILL BECOME OUR DOMINANT
WEATHER FEATURE TONIGHT. THE INCREASING PRESSURE GRADIENT BETWEEN
THIS LOW AND STRENGTHENING HIGH PRESSURE OVER PENNSYLVANIA WILL LEAD
TO INCREASING WIND SPEEDS LATE TONIGHT. A SURGE IS EXPECTED TO
DEVELOP A FEW HOURS BEFORE DAYBREAK...WITH WINDS TURNING
NORTH-NORTHEAST AND INCREASING TO 15-20 KT.
SEAS CURRENTLY RANGE FROM 5 FT OUT AT THE FRYING PAN SHOALS
BUOY...TO 3-4 FT CLOSER TO SHORE. STEADY ONSHORE WINDS THIS MORNING
SHOULD BRING 5-FOOTERS INTO THE 10-20 MILE WATERS...AND AN EXERCISE
CAUTION HEADLINE WILL BE APPENDED TO THE FORECAST THROUGH EARLY
AFTERNOON. DIMINISHING WINDS THIS AFTERNOON WILL ALLOW SEAS TO
SUBSIDE...BUT LOOK FOR BUILDING SEAS AGAIN VERY LATE TONIGHT IN THE
NORTHERLY SURGE.
SHOWERS AND THUNDERSTORMS CURRENTLY ACROSS EASTERN SOUTH CAROLINA
WILL IMPACT THE SC COASTAL WATERS THIS MORNING. GUSTY WINDS AND
REDUCED VISIBILITY IN HEAVY RAINFALL ARE EXPECTED. THIS ACTIVITY
WILL MOVE EAST AND AFFECT THE NC WATERS THIS AFTERNOON.
PRECIPITATION SHOULD BECOME LESS THUNDERY TONIGHT BUT SHOULD
OTHERWISE CONTINUE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...STRONG NE WINDS WILL PERSIST THROUGH THE
PERIOD AS THREE FEATURES COMBINE TO CREATE POOR MARINE CONDITIONS
INTO MID-WEEK. A WAVE OF LOW PRESSURE WILL DEVELOP ALONG A COLD
FRONT STALLED JUST OFFSHORE...ENHANCING THE ALREADY PINCHED GRADIENT
DUE TO A WEDGE OF HIGH PRESSURE FORMING DOWN THE COAST. THIS CREATES
GUSTY NE WINDS TUESDAY AND WEDNESDAY...WITH SPEEDS OF 15-25 KTS
TUESDAY...DROPPING SLIGHTLY TO 15-20 KTS ON WEDNESDAY. GUSTS TO 30
KTS ARE POSSIBLE...ESPECIALLY ON TUESDAY. THIS CREATES SHORT-PERIOD
AND STEEP WIND WAVES REACHING 4-7 FT TUESDAY...BEFORE FALLING SLOWLY
TO 3-5 FT BY WEDNESDAY EVE. A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR ALL OF TUESDAY AND PARTS OF WEDNESDAY BEFORE CONDITIONS
SLOWLY BEGIN TO IMPROVE LATE IN THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...GUSTY N/NE WINDS TO START THE PERIOD WILL
GRADUALLY EASE BY THE END OF THE WEEK AS HIGH PRESSURE WEDGE BEGINS
TO BREAK DOWN JUST INLAND FROM THE WATERS. TIGHT GRADIENT THURSDAY
KEEPS N/NE WINDS AT 15-20 KTS...BUT THIS WILL WEAKEN ON
FRIDAY...HELPING WINDS TO FALL TO AROUND 10 KTS AND BACK MORE TO THE
NORTH. WAVE HEIGHTS INITIALLY WILL BE 3-5 FT AND A SCEC MAY BE
REQUIRED...BUT THESE WILL FALL QUICKLY ON FRIDAY TO 2-3 FT THANKS TO
THE DECREASED WINDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...TRA
MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
130 AM EDT MON OCT 7 2013
.SYNOPSIS...
A FEW SHOWERS WILL CONTINUE THIS AFTERNOON AND TONIGHT. A STRONG
COLD FRONT WILL CROSS THE CAROLINAS LATE MONDAY...BRINGING A
PERIOD OF SHOWERS AND THUNDERSTORMS. MOISTURE AND BLUSTERY
CONDITIONS WILL CONTINUE TUESDAY AND WEDNESDAY. A DRYING TREND
SHOULD DEVELOP LATER IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 130 AM MONDAY...AN EARLY MORNING UPDATE HAS BEEN MADE TO RAISE
POPS ACROSS THE SC PEE DEE REGION INTO THE LIKELY (60-70 PERCENT)
RANGE. SHOWERS ADVECTING NORTHWARD FROM THE CHARLESTON VICINITY WILL
MOVE OVERHEAD FOR THE NEXT SEVERAL HOURS. ALSO MADE LARGE INCREASES
TO FORECAST SKY COVER. PREVIOUS DISCUSSION FROM 1100 PM
FOLLOWS...
STREAMER TYPE CONVECTION FROM OFF THE ATL WATERS TO CONTINUE
OVERNIGHT. SPEED CONVERGENCE IN THE LOWER LEVELS AS A RESULT OF THE
SE-S ONSHORE FLOW CONTINUES TO FIRE LOW TOPPED CONVECTION ACROSS THE
ILM COASTAL WATERS AND ONSHORE. WITH THE DAYS INSOLATION
OVERWITH...THE ACTIVITY THAT MOVES ONSHORE WILL FOR THE MOST PART BE
UNABLE TO SUSTAIN ITS INTENSITY LET ALONE ITS INTEGRITY AS IT
PROGRESSES FURTHER INLAND. THIS CURRENTLY IS BEING PLAYED OUT AS ONE
LOOPS THE KLTX AND SURROUNDING RADARS. ALTHOUGH CURRENT LTG REMAINS
LACKING...THE ACTIVITY OVER THE ADJACENT ATL WATERS WILL HAVE
INCREASING AND DEEPER INSTABILITY OVERNIGHT AS ACTIVITY PASSES OVER
SSTS THAT ARE AROUND 80 DEGREES. WOULD NOT BE SURPRISED FOR THUNDER
TO OCCUR...AND POSSIBLY REACH AND PUSH ONSHORE LATER OVERNIGHT. NO
PRONOUNCED UPPER S/W TROF OR VORT TO AFFECT THE FA OVERNITE THAT
WOULD PROVIDE ADDITIONAL FORCING TO FURTHER PROMOTE THUNDER. THIS IS
NOT PROGGED BY THE MODELS TO OCCUR UNTIL DAYTIME MONDAY WHILE
APPROACHING FROM THE WEST. HOWEVER...ENOUGH CAPE MANIFESTS ACROSS
THE FA TOWARD DAYBREAK MONDAY AS EXHIBITED BY THE LATEST HRRR MODEL
RUN...TO AT-LEAST MENTION ISOLATED THUNDER DURING THIS TIME FRAME.
OVERALL...POPS ACROSS THE FA OVERNIGHT WILL RANGE BETWEEN 25 TO 50
PERCENT.
WIDESPREAD 70+ SFC DEWPOINTS CURRENTLY ACROSS THE FA. DO NOT SEE
MUCH OF A DOWNWARD OR DECREASING TREND OVERNITE WITH SFC DEWPOINTS.
AS A RESULT...LOOKING AT WIDESPREAD 70 TO 75 DEGREE LOWS FOR
TONIGHT...WHICH IS NEARLY 15 DEGREES HIGHER THAN CLIMO NORMS FOR
THIS TIME OF THE YEAR. MUST BE GLOBAL WARMING AGAIN.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...THE SHORT TERM CONTINUES TO TREND TO A VERY
ACTIVE PERIOD MOSTLY AS A RESULT OF MODEL CONSENSUS ON THE EVENTS
FOR TUESDAY.
THE 1200 UTC GFS AND NAM ARE IN AGREEMENT ON A MID LEVEL LOW CUTTING
OFF IN THE SOUTHEAST TUESDAY WITH BROAD ISENTROPIC LIFT DEVELOPING
BETWEEN STRONG HIGH PRESSURE TO THE NORTH AND THE ASSOCIATED SURFACE
LOW/TROUGH TO THE SOUTH. IT WILL BE A RATHER WET AND RAW DAY AS
GUIDANCE SHOWS HIGH TEMPERATURES REMAINING IN THE 60S WITH WIND
SPEEDS FROM THE EAST/NORTHEAST AT 10-15 MPH. THE LACK OF SATURATION
IN THE 305K LAYER AND MODEST ISENTROPIC LIFT...WINDS ARE ACTUALLY
FAIRLY LIGHT ABOVE THE SURFACE MAY KEEP QPF VALUES MODEST. HOWEVER
SUBSEQUENT SHIFTS MAY WANT TO INCREASE POPS ESPECIALLY LATE IN THE
PERIOD AS THE COLUMN SHOWS BETTER SATURATION IN THIS LAYER.
AS FOR THE EVENTS MONDAY...LITTLE CHANGE WAS WARRANTED WITH THE
FORECAST AS THE MODELS ARE STILL IN AGREEMENT ON THE
FRONT...CURRENTLY LOCATED IN THE TENNESSEE VALLEY MOVING ACROSS
MONDAY EVENING. MAINTAINED THE LIKELY TO CATEGORICAL POPS WITH THE
SAME TEMPORAL TRENDS.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...WEDNESDAY NO LONGER LOOKING DRY AS PREVIOUSLY
THOUGHT. A WEAK SOUTHERN BRANCH SHORTWAVE LIFTS OUT OF THE GULF OF
MEXICO EARLY IN THE WEEK AND CROSSES THE CAROLINAS WEDNESDAY. THERE
IS STILL COPIOUS/DEEP MOISTURE IN PLACE AS THE THE MONDAY COLD FRONT
ONLY SEEMS TO REMOVE THE SURFACE MOISTURE. THE UPPER SYSTEM INDUCES
A WAVE ALONG THE BOUNDARY WELL OFFSHORE ON WEDNESDAY BUT ITS
LOCATION IS NOT AGREED UPON BY VARIOUS GUIDANCE. INTERESTINGLY THE
EC DOESN`T REALLY DEVELOP A WAVE BUT STILL HAS QPF AS THE UPPER
SHORTWAVE MOVES ATOP THE WEDGE. WILL INTRODUCE LOW CHC POPS MAINLY
ALONG THE COAST. MOST IF NOT ALL OF THE REMAINDER OF THE PERIOD WILL
BRING DRY WEATHER AS BUILDING UPPER LEVEL RIDGE AND SOUTHWARD
SPRAWLING SURFACE HIGH OCCUPY OUR LONGITUDE. THE GFS CONTINUES TO
SHOW THAT OUR WEDNESDAY SHORTWAVE EVENTUALLY BEARS A LOW OFF THE
DELMARVA COAST THAT RETROGRADES AND MAY BRING SOME WEEKEND POPS. FOR
NOW THIS LOOKS JUST ANOMALOUS ENOUGH TO CAP POPS AT SLIGHT. THE EC
ALSO SHOWS SOME ATLANTIC DEVELOPMENT BUT NOT THE RETROGRADING MOTION.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...BAND OF SHOWERS EMANATING FROM THE ATLANTIC OCEAN NEAR
CHARLESTON WILL AFFECT FLORENCE AND LUMBERTON EARLY THIS MORNING.
THE BIGGEST THREAT WILL BE TRANSIENT LOW CEILINGS NEAR MODERATE
RAINFALL. AT FLORENCE THERE IS A MODERATE CHANCE OF SUB-1000 FOOT
CEILINGS THROUGH 09Z...WITH LOW PROBABILITIES OF IFR CIGS THROUGH
DAYBREAK. AT LUMBERTON IFR PROBABILITIES ARE LOWER BUT CANNOT
TOTALLY BE RULED OUT. FOR THE COASTAL AIRPORTS (ILM, MYR, CRE) THE
BULK OF THE SHOWER ACTIVITY OVER THE NEXT 6 HOURS SHOULD REMAIN TO
THE WEST...WITH GENERALLY VFR TO OCCASIONAL MVFR CONDITIONS
EXPECTED.
AN APPROACHING COLD FRONT WILL BRING SHRA TO OUR FORECAST AREA LATER
TODAY. VFR/MVFR CONDITIONS SHOULD PREVAIL...WITH TEMPO PERIODS OF
IFR VSBYS IN HEAVIER SHOWERS. FCST SOUNDINGS SUGGEST THERE WILL BE
ENOUGH INSTABILITY FOR AT LEAST ISOLATED T-STORMS...SO HAVE INCLUDED
VCTS FOR ALL TERMS DURING THE DAYTIME. SOUTHERLY FLOW WILL PERSIST
FOR MUCH OF THE DAY WITH WINDS AROUND 10 KTS. THE FRONT WILL PASS
THROUGH KFLO/KLBT AROUND 00Z TUESDAY...WITH WINDS BECOMING NORTHEAST
AROUND 5 KTS FOLLOWING FROPA. BY 06Z TUESDAY...THE FRONT SHOULD BE
NEAR THE COAST OR JUST OFFSHORE. WILL HOLD ONTO VCSH AT ALL TERMS
THROUGH THE END OF THE TAF PERIOD AS DEEP MOISTURE LINGERS OVER OUR
AREA.
EXTENDED OUTLOOK...SCATTERED SHOWERS WITH MVFR CIGS ON TUESDAY AS
THE FRONT LINGERS OFFSHORE. MVFR/IFR CIGS AND ISOLATED SHOWERS
POSSIBLE ON WEDNESDAY MORNING...BECOMING VFR THURSDAY AND FRIDAY.&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM MONDAY...NO SIGNIFICANT CHANGES NECESSARY. PREVIOUS
DISCUSSION FROM 1100 PM FOLLOWS...
LATEST PIER AND BUOY OBS ACROSS THE AREA WATERS INDICATE WINDS ARE
RUNNING CLOSE TO THE CURRENT FORECAST TREND. WILL ONLY MAKE SLIGHT
ADJUSTMENTS TO WIND DIRECTIONS...WITH SE-S BEING ADVERTISED INSTEAD
OF INDICATING A SSE WIND DIRECTION. LATEST HRRR SFC WIND OUTPUT
ACROSS THE ILM WATERS CONTINUES WITH 10-15 KT...INCREASING TO 15-20
KT BY DAYBREAK. THIS ONSHORE FLOW WILL BUILD SIGNIFICANT SEAS RATHER
QUICKLY OVERNIGHT...WITH THE MAJORITY OF THE ILM COASTAL WATERS AT 3
TO 5 FT BY DAYBREAK MONDAY. BUILDING WIND DRIVEN WAVES AT 4 TO 6
SECOND PERIODS WILL DOMINATE THE WAVE SPECTRUM OVERNIGHT. THE SMALL
ESE 9 TO 11 SECOND PERIOD GROUND SWELL WILL PROVIDE NO AID FOR
INCREASING THE SIG. SEAS.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...THE MARINE COMMUNITY WILL SEE RATHER CHANGEABLE
CONDITIONS THROUGH THE PERIOD. EXPECT A SOUTHEAST FLOW OF 15-20
KNOTS INITIALLY. THIS FLOW WILL WEAKEN AND VEER TO THE SOUTH THEN
SOUTHWEST BY THE END OF THE DAY MONDAY. A FRONT WILL MOVE ACROSS THE
WATERS AROUND 0600 UTC TUESDAY WITH A NORTH TO NORTHEASTERLY FLOW
DEVELOPING BY 1200 TUESDAY. SPEEDS WILL INCREASE AS WELL TO 15-20
KNOTS BY THIS TIME. THIS PATTERN WILL REMAIN IN PLACE THROUGH THE
END OF THE PERIOD. SIGNIFICANT SEAS ARE 3-5 FEET EARLY IN THE PERIOD
WITH A DECREASE MONDAY EVENING. SEAS WILL INCREASE ONCE AGAIN
TUESDAY ESPECIALLY LATER IN THE DAY TO POSSIBLY SMALL CRAFT
CRITERIA.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...LONG DURATION OF NORTHERLY FLOW EXPECTED.
HIGH PRESSURE WEDGING IN EAST OF THE APPALACHIANS TO PRODUCE A
MODERATE GRADIENT ACROSS THE WATERS. A WAVE OF LOW PRESSURE SHOULD
DEVELOP SOMEWHERE ALONG COLD FRONT STALLED WELL OFFSHORE BUT ITS
LOCATION IS UNCERTAIN AT THIS POINT. THIS IS EXPECTED TO MODULATE
THE STRENGTH OF THE GRADIENT AND HAVE AN IMPACT ON THE STRENGTH OF
THE GRADIENT PINCH AND WHETHER OR NOT WELL NEED ANY HEADLINES OR
EVEN BORDERLINE AND SHORT-LIVED ADVISORY OUT ALONG FRYING PAN
SHOALS. WHEREVER THIS LOW DEVELOPS...IT WILL PULL AWAY TO THE
NORTH AND EAST THURSDAY INTO FRIDAY AND THE SURFACE HIGH WILL
REMAIN ENTRENCHED ACROSS THE EASTERN U.S.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH/TRA
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
531 AM EDT MON OCT 7 2013
.SYNOPSIS...
A COLD FRONT OVER WESTERN PENNSYLVANIA WILL CONTINUE TO PUSH TO
THE EAST AND SHOULD BE OUT OF THE AREA BY LATE AFTERNOON. TROPICAL
MOISTURE AND HIGH WIND SHEAR WILL CREATE THE POSSIBILITY OF STRONG
THUNDERSTORMS AND BRIEF HEAVY RAIN AS THE COLD FRONT MOVES THROUGH.
HIGH PRESSURE IS EXPECTED TO RETURN FOR TUESDAY. A WEAK LOW
PRESSURE AREA MAY DEVELOP TO OUR SOUTH DURING THE MIDDLE OF THE
WEEK AND CRAWL SLOWLY NORTHWARD THROUGH THE SECOND HALF OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS NOW COVER MOST OF THE AREA...BUT RAINFALL JUST STARTING TO
ENTER THE WESTERN HIGHLANDS. THE COLD FRONT SEEMS TO BE JUST AT
THE LEADING EDGE OF THE RAIN. A STEADY PROGRESSION OF BOTH THE
FRONT AND THE RAIN SHIELD WILL OCCUR THROUGH THE DAY. ALL MODELS
IN VERY GOOD AGREEMENT RIGHT NOW. CONFIDENCE IS HIGH IN THE
FORECAST TIMING. SREF RAINFALL AMOUNTS OF BETWEEN ONE AND ONE AND
A HALF INCHES SEEMS REASONABLE. THEE DURATION OF THE RAIN SHOULD
BE ABOUT 6 HRS...WHICH SHOULD KEEP ANY FLOODING WORRIES TO A BARE
MINIMUM. SOME PONDING OF WATER IN THE NORMAL PLACES...BUT NOT EVEN
SMALL STREAM FLOODING. MUCH OF THE AREA HAS BEEN QUITE DRY LATELY.
THE MAIN FORECAST PROBLEM TODAY IS HOW UNSTABLE IT WILL GET OVER
THE EASTERN HALF OF THE AREA THIS AFTERNOON. CLOUDS COVER THE
AREA AT 5 AM AND DEEP SERLY FLOW AHEAD OF THE FRONT SHOULD ONLY
REINFORCE THE CLOUD COVER. TEMPS MAY BE AT THEIR MAXES IN THE
WESTERN HIGHLANDS...BUT THE EAST COULD HAVE 6-7 HRS OF POTENTIAL
HEATING. THE COLD FRONT SHOULD BE PASSING THROUGH STATE COLLEGE
ABOUT NOON/1 PM...AND HARRISBURG AROUND 2/3 PM. AREAS TO THE EAST
OF THE FRONT WHICH CAN GENERATE SOME MODERATE INSTABILITY COULD HAVE
SOME THUNDERSTORMS DEVELOP IN THE VERY STRONG SWRLY FLOW AHEAD OF
THE FRONT. THE WINDS JUST 1-2KFT OFF THE GROUND WILL BE RACING AT
50KTS. IT WON/T TAKE MUCH TO MIX THAT DOWN...BUT THE CLOUDS WILL
CUT DOWN ON HEATING WHICH WILL COUNTER-BALANCE THE THREAT. SPC
DOES PLACE THE ERN HALF OF THE AREA INTO SLIGHT RISK. BUT THE LACK
OF HEATING WILL BE THE TRICK. NAM MAKES LI AROUND -4 WITH TT AT 46
AND CAPE IN THE 1000+ RANGE AT MDT LATE THIS MORNING. SO A MENTION
OF GUSTY WINDS IS AN EASY CALL...BUT MENTIONING SEVERE IS A BIT
OF A STRETCH.
CLEAR SLOT WILL LIKELY DEVELOP AFTER THE RAIN SHIELD MOVES TO THE
EAST IN ALL LOCATIONS...BUT THE WNW FLOW BEHIND IT WILL LIKELY
BRING CLOUDS BACK INTO THE NW/LAURELS THIS EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
DRYING TAKES PLACE VERY QUICKLY AFTER FROPA. ALL PRECIP SHOULD BE
TO THE EAST AT THE START OF THE PERIOD. SOME POST-FRONTAL COLD
ADVECTION CLOUDS ARE POSSIBLE IN THE MOUNTAINS TONIGHT...BUT CLEAR
SKIES EXPECTED ELSEWHERE. TEMPS WILL TAKE A TUMBLE INTO THE 40S
TONIGHT...AND RIVER VALLEY FOG IS POSSIBLE. BUT THE WINDS WILL
STAY UP FOR AT LEAST THE FIRST PART OF THE NIGHT.
ANY CLOUDS WILL DISSIPATE ON TUESDAY...BUT SCT DIURNAL CU MAY
DEVELOP UNDER THE COLD POCKET ALOFT AIR WITH HIGH AMBIENT
MOISTURE FROM THE RAIN TODAY. 8H TEMPS DROP INTO THE LOWER SINGLE
DIGITS BY TUES MORNING AND HOLD THERE FOR THE DAYTIME. MAXES WILL
THEREFORE BE HELD TO THE 50S IN THE MOUNTAINS AND LOWER TO MID 60S
ELSEWHERE THANKS TO THE DOWNSLOPE IN THE SERN HALF.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HAVE TWEAKED WED NIGHT-THURS NIGHT TO REFLECT THE POSSIBLE EFFECTS
OF A LOW SLATED TO DEVELOP TO THE SOUTH ALONG THE EASTERN
SEABOARD. THIS COULD BRING SHOWERS UP INTO THE SRN/SERN PARTS OF
THE AREA...AND HOLD TEMPS DOWN A BIT AS WELL.
PREV DISCO...
THE MODELS CONTINUE TO BE IN AGREEMENT WITH A NEARLY NEUTRAL
TROUGH EXTENDING FROM THE LOW CENTER THAT CONTINUES TO MOVE
NORTHWARD. COOLER AIR WILL ADVECT INTO THE REGION BEHIND THE FRONT
MONDAY NIGHT...AS ANY LINGERING SHOWERS SHOULD BE GONE BY 06Z
TUESDAY. THE PATTERN FLATTENS OUT QUICKLY TUESDAY MORNING AS
SURFACE HIGH PRESSURE SETTLES IN FOR THE LONG HAUL ON TUESDAY. THE
UPPER RIDGE RE-ASSERTS IT/S STRENGTH OVER THE ERN U.S.
TEMPERATURES WILL BE COOLER THAN NORMAL ON TUESDAY...WITH MORE
SEASONABLE TEMPS THROUGH THE REST OF THE WEEK. WITH THE DRY AIR
AND SUBSIDENCE EVERY MORNING...IT WILL BE A CLASSIC SET-UP FOR
VERY CHILLY MORNINGS. HOWEVER...THE ABNORMALLY HIGH 5H
HEIGHTS...8H TEMPS OF 10 TO 12C AND THICKNESSES IN THE MID 560S
WILL PRECLUDE ALL BE THE VERY COLDEST LOCATIONS FROM GETTING NEAR
FREEZING AT NIGHT. THE COLDEST TIME FRAME WILL BE TUESDAY
NIGHT/WED MORNING. FROST IS POSSIBLE ACROSS THE NORTH. RESIDUAL
MOISTURE MOVING ONSHORE...ALONG WITH A WEAK SFC LOW COULD ALLOW
FOR EASTERLY FLOW LATE THURSDAY INTO FRIDAY. THIS MOIST ONSHORE
FLOW COULD BRING ISOLATED SHOWERS THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON TO THE LOWER SUSQUEHANNA VALLEY. THIS LOW PRESSURE
SFC/ALOFT WILL CONTINUE TO DEVELOP OVER THE WESTERN ATLANTIC UNDER
THE UPPER RIDGE AND WILL CONTINUE TO RETROGRADE INTO
SATURDAY...BEFORE DRIFTING OUT TO SEA. HAVE SLIGHTLY INCREASED
POPS IN THE SOUTHEAST DURING THIS TIMEFRAME.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ACROSS CONTINUE ACROSS WESTERN AIRFIELDS EARLY THIS
MORNING AS REGION REMAINS IN WARM SECTOR...AWAITING ARRIVAL OF A
COLD FRONT LATER THIS MORNING. CIGS AT SUSQUEHANNA RIVER VALLEY
TAF SITES...MDT...LNS AND IPT HAVE FALLEN INTO MVFR RANGE AS
GUSTY S/SE WINDS...WITH GUSTS PEAKING AT AROUND 25 MPH AT TIMES
HAVE PUSHED MARINE LAYER FROM THE ATLANTIC OCEAN TO PUSH
NORTHWESTWARD ACROSS CWA.
EXPECT EXPANSION OF THE MVFR/IFR STRATOCU DECK AS NIGHT
PROGRESSES. SCT SHOWERS WILL BECOME POSSIBLE IN THE VERY MOIST AIR
OVER E PA AND THE SUSQ VALLEY AFTER 08Z AS LARGE SCALE LIFT BEGINS
TO INCREASE...AND THESE SHOWERS ARE HINTED AT IN THE HRRR MODEL
FORECAST. SO ADDED VCSH TO EASTERN TERMINALS OVERNIGHT.
FOCUS THEN TURNS TO POTENT SFC COLD FRONT EXPECTED TO BE NEAR A
KBFD TO KJST LINE BY 12Z...AND PUSHING STEADILY EAST ACROSS THE
REST OF THE REGION DURING THE LATE MORNING AND EARLY AFTERNOON
HOURS. A NARROW LINE /ABOUT 4 HOURS/ OF HEAVY SHOWERS/LOW-TOPPED
TSRA SHOULD ACCOMPANY THE IMMEDIATE CFROPA...WHILE ISOLATED
SUPERCELLS ARE POSSIBLE WELL TO THE EAST OF THE FRONT IN THE
HIGHLY SHEARED ENVIRONMENT /MAINLY AFTER SUNRISE IN EASTERN
SECTIONS/. THESE INDIVIDUAL CELLS WILL TRACK RAPIDLY TO THE NE AT
40 KTS PLUS. ANY OF THESE LEAD STORMS /OR THE EXPECTED LINE ALONG
THE FRONT/ COULD MIX DOWN STRONG WIND GUSTS TO THE SFC.
CONDITIONS IMPROVE FROM WEST TO EAST WITHIN A FEW HOURS OF
FROPA AS PRECIP COMES TO AN END AND CEILINGS/VSBYS RETURN TO VFR
FOR THE SECOND HALF OF MON /AS RIDGING BEGINS IN LOWER LEVELS/.
WINDS TURN WESTERLY AND REMAIN AROUND 15 MPH GUSTING TO 25 MPH
BEFORE DIMINISHING LATER IN THE DAY.
CIG RESTRICTIONS LIKELY IN WESTERN/NORTHERN MTNS MON NIGHT AS
COLDEST MID LEVEL AIR RETREATS TO THE NE AND LOW LEVEL SUBSIDENCE
INVERSION SQUEEZES MOISTURE INTO A STABLE STRATOCU DECK.
OUTLOOK...
TUE...SCT AM SHOWERS/LOW CIGS POSSIBLE N AND W.
WED-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...DANGELO/CERU
AVIATION...GARTNER/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
313 AM EDT MON OCT 7 2013
.SYNOPSIS...
A COLD FRONT OVER WESTERN PENNSYLVANIA WILL CONTINUE TO PUSH TO
THE EAST AND SHOULD BE OUT OF THE AREA BY LATE AFTERNOON. TROPICAL
MOISTURE AND HIGH WIND SHEAR WILL CREATE THE POSSIBILITY OF STRONG
THUNDERSTORMS AND BRIEF HEAVY RAIN AS THE COLD FRONT MOVES THROUGH.
HIGH PRESSURE IS EXPECTED TO RETURN FOR TUESDAY AND KEEP MAINLY
FAIR WEATHER OVER THE FORECAST AREA THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
COLD FRONT IS VISIBLE ON RADAR MOSAIC NEAR KPIT AND JUST PAST
KERI. WIND SHIFT/PRESSURE RISES ARE SEEN IN MANY OBS OVER ERN
OHIO. RAIN SHIELD IS BEHIND THE FRONT...BUT STRONG SRLY LLVL JET
WILL LIKELY KEEP THE SHOWERS MOVING RIGHT ALONG WITH THE FRONT
THROUGH THE REST OF THE NIGHT AND EARLY THIS MORNING. LITTLE SFC-
BASED INSTABILITY IS POSSIBLE BEFORE SUNRISE. GUSTY WIND SHOULD
CONTINUE AS THE PRESSURE GRADIENT IS TIGHT.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE MAIN ACTION OF THE WEEK AHEAD WILL BE CAPTURED IN THIS PERIOD AS
A RELATIVELY STRONG SFC COLD FRONT PUSHES EAST ACROSS THE
COMMONWEALTH. A HIGHLY ANOMALOUS SOUTHERLY LLJ /50KTS AND PLUS 3-4
SIGMA VIA THE 09Z AND 12Z SREF AND GEFS/ WILL SLIDE EAST ALONG AND
AHEAD OF THE FRONT MONDAY MORNING INTO EARLY MONDAY AFTERNOON.
EVEN THE SEEMINGLY HARMLESS /AND LOW/ FEW TO SEVERAL HUNDRED JOULES
OF SFC-BASED CAPE GENERATED IN THE MAINLY CLOUDY AIRMASS AHEAD OF
THE FRONT WILL BE ENOUGH TO COMBINE WITH THE STRONG DEEP-LAYER SHEAR
TO POSE THE THREAT FOR A NCFRB AND A FEW SWATHS OF STRONG/DAMAGING
STRAIGHT LINE WINDS.
THE SHARPLY VEERING AND VERY STRONG LLVL WIND PROFILE WILL ALSO
YIELD HIGH 0-3KM HELICITY OF 250-350 M2/S2...WHICH WILL BE CAPABLE
OF SUPPORTING SOME LOW-TOPPED AND FAST NEWD MOVING MINI SUPERCELLS
WELL AHEAD OF THE COLD FRONT /AND A FEW BKN-S SIGNATURES WITHIN THE
NCFRB/.
HIGH TEMPS WILL BE REACHED EARLY IN THE DAY ACROSS THE WEST...AND
EARLY AFTERNOON ACROSS THE SUSQ VALLEY WITH FEW TO SVRL DEG DIP IN
TEMPS BEHIND THE FRONT.
BEST WIND GUST POTENTIAL WILL BE ALONG AND AHEAD OF THE COLD FRONT
WITH A GUSTY /BUT NOT IMPRESSIVE/ WESTERLY FLOW BEHIND THE
FRONT.
STORM TOTAL RAINFALL WILL LIKELY RANGE FROM 1 TO 1.5 INCHES IN MOST
LOCATIONS...WHICH IS A DEFINITE DOWNWARD ADJUSTMENT FROM THE PAST
FEW DAYS GIVEN THE FACT THAT THERE WILL BE VERY LITTLE INFLUENCE
FROM THE REMNANTS OF TS KAREN THAT WILL WEAKEN FURTHER OVER THE NEXT
36 HOURS OVER THE SERN STATES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MODELS CONTINUE TO BE IN AGREEMENT WITH A NEARLY NEUTRAL TROUGH
EXTENDING FROM THE LOW CENTER THAT CONTINUES TO MOVE NORTHWARD.
COOLER AIR WILL ADVECT INTO THE REGION BEHIND THE FRONT MONDAY
NIGHT...AS ANY LINGERING SHOWERS SHOULD BE GONE BY 06Z TUESDAY.
THE PATTERN FLATTENS OUT QUICKLY TUESDAY MORNING AS SURFACE HIGH
PRESSURE SETTLES IN FOR THE LONG HAUL ON TUESDAY. THE UPPER RIDGE
RE-ASSERTS IT/S STRENGTH OVER THE ERN U.S. TEMPERATURES WILL BE
COOLER THAN NORMAL ON TUESDAY...WITH MORE SEASONABLE TEMPS THROUGH
THE REST OF THE WEEK. WITH THE DRY AIR AND SUBSIDENCE EVERY
MORNING...IT WILL BE A CLASSIC SET-UP FOR VERY CHILLY MORNINGS.
HOWEVER...THE ABNORMALLY HIGH 5H HEIGHTS...8H TEMPS OF 10 TO 12C AND
THICKNESSES IN THE MID 560S WILL PRECLUDE ALL BE THE VERY COLDEST
LOCATIONS FROM GETTING NEAR FREEZING AT NIGHT. THE COLDEST TIME
FRAME WILL BE TUESDAY NIGHT/WED MORNING. FROST IS POSSIBLE ACROSS
THE NORTH. RESIDUAL MOISTURE MOVING ONSHORE...ALONG WITH A WEAK SFC
LOW COULD ALLOW FOR EASTERLY FLOW LATE THURSDAY INTO FRIDAY.
THIS MOIST ONSHORE FLOW COULD BRING ISOLATED SHOWERS THURSDAY NIGHT
THROUGH FRIDAY AFTERNOON TO THE LOWER SUSQUEHANNA VALLEY.
THIS LOW PRESSURE SFC/ALOFT WILL CONTINUE TO DEVELOP OVER THE
WESTERN ATLANTIC UNDER THE UPPER RIDGE AND WILL CONTINUE TO
RETROGRADE INTO SATURDAY...BEFORE DRIFTING OUT TO SEA. HAVE
SLIGHTLY INCREASED POPS IN THE SOUTHEAST DURING THIS TIMEFRAME.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ACROSS CONTINUE ACROSS WESTERN AIRFIELDS EARLY THIS
MORNING AS REGION REMAINS IN WARM SECTOR...AWAITING ARRIVAL OF A
COLD FRONT LATER THIS MORNING. CIGS AT SUSQUEHANNA RIVER VALLEY
TAF SITES...MDT...LNS AND IPT HAVE FALLEN INTO MVFR RANGE AS
GUSTY S/SE WINDS...WITH GUSTS PEAKING AT AROUND 25 MPH AT TIMES
HAVE PUSHED MARINE LAYER FROM THE ATLANTIC OCEAN TO PUSH
NORTHWESTWARD ACROSS CWA.
EXPECT EXPANSION OF THE MVFR/IFR STRATOCU DECK AS NIGHT
PROGRESSES. SCT SHOWERS WILL BECOME POSSIBLE IN THE VERY MOIST AIR
OVER E PA AND THE SUSQ VALLEY AFTER 08Z AS LARGE SCALE LIFT BEGINS
TO INCREASE...AND THESE SHOWERS ARE HINTED AT IN THE HRRR MODEL
FORECAST. SO ADDED VCSH TO EASTERN TERMINALS OVERNIGHT.
FOCUS THEN TURNS TO POTENT SFC COLD FRONT EXPECTED TO BE NEAR A
KBFD TO KJST LINE BY 12Z...AND PUSHING STEADILY EAST ACROSS THE
REST OF THE REGION DURING THE LATE MORNING AND EARLY AFTERNOON
HOURS. A NARROW LINE /ABOUT 4 HOURS/ OF HEAVY SHOWERS/LOW-TOPPED
TSRA SHOULD ACCOMPANY THE IMMEDIATE CFROPA...WHILE ISOLATED
SUPERCELLS ARE POSSIBLE WELL TO THE EAST OF THE FRONT IN THE
HIGHLY SHEARED ENVIRONMENT /MAINLY AFTER SUNRISE IN EASTERN
SECTIONS/. THESE INDIVIDUAL CELLS WILL TRACK RAPIDLY TO THE NE AT
40 KTS PLUS. ANY OF THESE LEAD STORMS /OR THE EXPECTED LINE ALONG
THE FRONT/ COULD MIX DOWN STRONG WIND GUSTS TO THE SFC.
CONDITIONS IMPROVE FROM WEST TO EAST WITHIN A FEW HOURS OF
FROPA AS PRECIP COMES TO AN END AND CEILINGS/VSBYS RETURN TO VFR
FOR THE SECOND HALF OF MON /AS RIDGING BEGINS IN LOWER LEVELS/.
WINDS TURN WESTERLY AND REMAIN AROUND 15 MPH GUSTING TO 25 MPH
BEFORE DIMINISHING LATER IN THE DAY.
CIG RESTRICTIONS LIKELY IN WESTERN/NORTHERN MTNS MON NIGHT AS
COLDEST MID LEVEL AIR RETREATS TO THE NE AND LOW LEVEL SUBSIDENCE
INVERSION SQUEEZES MOISTURE INTO A STABLE STRATOCU DECK.
OUTLOOK...
TUE...SCT AM SHOWERS/LOW CIGS POSSIBLE N AND W.
WED-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...DANGELO/CERU
AVIATION...GARTNER/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
120 AM EDT MON OCT 7 2013
.SYNOPSIS...
A COLD FRONT OVER WESTERN PENNSYLVANIA WILL CONTINUE TO PUSH TO
THE EAST AND SHOULD BE OUT OF THE AREA BY LATE AFTERNOON. TROPICAL
MOISTURE AND HIGH WIND SHEAR WILL CREATE THE POSSIBILITY OF STRONG
THUNDERSTORMS AND BRIEF HEAVY RAIN AS THE COLD FRONT MOVES THROUGH.
HIGH PRESSURE IS EXPECTED TO RETURN FOR TUESDAY AND KEEP MAINLY
FAIR WEATHER OVER THE FORECAST AREA THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
COLD FRONT IS VISIBLE ON RADAR MOSAIC NEAR KPIT AND JUST PAST
KERI. WIND SHIFT/PRESSURE RISES ARE SEEN IN MANY OBS OVER ERN
OHIO. RAIN SHIELD IS BEHIND THE FRONT...BUT STRONG SRLY LLVL JET
WILL LIKELY KEEP THE SHOWERS MOVING RIGHT ALONG WITH THE FRONT
THROUGH THE REST OF THE NIGHT AND EARLY THIS MORNING. LITTLE SFC-
BASED INSTABILITY IS POSSIBLE BEFORE SUNRISE. GUSTY WIND SHOULD
CONTINUE AS THE PRESSURE GRADIENT IS TIGHT.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE MAIN ACTION OF THE WEEK AHEAD WILL BE CAPTURED IN THIS PERIOD AS
A RELATIVELY STRONG SFC COLD FRONT PUSHES EAST ACROSS THE
COMMONWEALTH. A HIGHLY ANOMALOUS SOUTHERLY LLJ /50KTS AND PLUS 3-4
SIGMA VIA THE 09Z AND 12Z SREF AND GEFS/ WILL SLIDE EAST ALONG AND
AHEAD OF THE FRONT MONDAY MORNING INTO EARLY MONDAY AFTERNOON.
EVEN THE SEEMINGLY HARMLESS /AND LOW/ FEW TO SEVERAL HUNDRED JOULES
OF SFC-BASED CAPE GENERATED IN THE MAINLY CLOUDY AIRMASS AHEAD OF
THE FRONT WILL BE ENOUGH TO COMBINE WITH THE STRONG DEEP-LAYER SHEAR
TO POSE THE THREAT FOR A NCFRB AND A FEW SWATHS OF STRONG/DAMAGING
STRAIGHT LINE WINDS.
THE SHARPLY VEERING AND VERY STRONG LLVL WIND PROFILE WILL ALSO
YIELD HIGH 0-3KM HELICITY OF 250-350 M2/S2...WHICH WILL BE CAPABLE
OF SUPPORTING SOME LOW-TOPPED AND FAST NEWD MOVING MINI SUPERCELLS
WELL AHEAD OF THE COLD FRONT /AND A FEW BKN-S SIGNATURES WITHIN THE
NCFRB/.
HIGH TEMPS WILL BE REACHED EARLY IN THE DAY ACROSS THE WEST...AND
EARLY AFTERNOON ACROSS THE SUSQ VALLEY WITH FEW TO SVRL DEG DIP IN
TEMPS BEHIND THE FRONT.
BEST WIND GUST POTENTIAL WILL BE ALONG AND AHEAD OF THE COLD FRONT
WITH A GUSTY /BUT NOT IMPRESSIVE/ WESTERLY FLOW BEHIND THE
FRONT.
STORM TOTAL RAINFALL WILL LIKELY RANGE FROM 1 TO 1.5 INCHES IN MOST
LOCATIONS...WHICH IS A DEFINITE DOWNWARD ADJUSTMENT FROM THE PAST
FEW DAYS GIVEN THE FACT THAT THERE WILL BE VERY LITTLE INFLUENCE
FROM THE REMNANTS OF TS KAREN THAT WILL WEAKEN FURTHER OVER THE NEXT
36 HOURS OVER THE SERN STATES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MODELS CONTINUE TO BE IN AGREEMENT WITH A NEARLY NEUTRAL TROUGH
EXTENDING FROM THE LOW CENTER THAT CONTINUES TO MOVE NORTHWARD.
COOLER AIR WILL ADVECT INTO THE REGION BEHIND THE FRONT MONDAY
NIGHT...AS ANY LINGERING SHOWERS SHOULD BE GONE BY 06Z TUESDAY.
THE PATTERN FLATTENS OUT QUICKLY TUESDAY MORNING AS SURFACE HIGH
PRESSURE SETTLES IN FOR THE LONG HAUL ON TUESDAY. THE UPPER RIDGE
RE-ASSERTS IT/S STRENGTH OVER THE ERN U.S. TEMPERATURES WILL BE
COOLER THAN NORMAL ON TUESDAY...WITH MORE SEASONABLE TEMPS THROUGH
THE REST OF THE WEEK. WITH THE DRY AIR AND SUBSIDENCE EVERY
MORNING...IT WILL BE A CLASSIC SET-UP FOR VERY CHILLY MORNINGS.
HOWEVER...THE ABNORMALLY HIGH 5H HEIGHTS...8H TEMPS OF 10 TO 12C AND
THICKNESSES IN THE MID 560S WILL PRECLUDE ALL BE THE VERY COLDEST
LOCATIONS FROM GETTING NEAR FREEZING AT NIGHT. THE COLDEST TIME
FRAME WILL BE TUESDAY NIGHT/WED MORNING. FROST IS POSSIBLE ACROSS
THE NORTH. RESIDUAL MOISTURE MOVING ONSHORE...ALONG WITH A WEAK SFC
LOW COULD ALLOW FOR EASTERLY FLOW LATE THURSDAY INTO FRIDAY.
THIS MOIST ONSHORE FLOW COULD BRING ISOLATED SHOWERS THURSDAY NIGHT
THROUGH FRIDAY AFTERNOON TO THE LOWER SUSQUEHANNA VALLEY.
THIS LOW PRESSURE SFC/ALOFT WILL CONTINUE TO DEVELOP OVER THE
WESTERN ATLANTIC UNDER THE UPPER RIDGE AND WILL CONTINUE TO
RETROGRADE INTO SATURDAY...BEFORE DRIFTING OUT TO SEA. HAVE
SLIGHTLY INCREASED POPS IN THE SOUTHEAST DURING THIS TIMEFRAME.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ACROSS MAJORITY OF CENTRAL PA AT MIDNIGHT AS
REGION REMAINS IN WARM SECTOR...AWAITING ARRIVAL OF A COLD FRONT
LATER TONIGHT/EARLY MON. BIGGEST AVIATION CONCERN FOR NEXT SEVERAL
HOURS WILL BE A GUSTY S/SE WIND...WITH GUSTS PEAKING AT AROUND 25
MPH AT TIMES. MOIST FLOW IS ALLOWING A MARINE LAYER FROM THE
ATLANTIC TO PUSH NORTHWESTWARD ACROSS CWA...RAISING DEWPOINTS BY
NEARLY 10F. BIGGER IMPACTS OF THIS MARINE LAYER ARE BEGINNING TO
DEVELOP AS POTENT SOUTHERLY LOW-LEVEL JET SLIDES EAST FROM OHIO
VALLEY...PROVIDING THE LIFT TO INITIATE DEVELOPMENT OF AN MVFR/IFR
STRATOCU DECK. THESE CLOUDS WILL DEVELOP FIRST IN THE MOIST
AIRMASS OVER EASTERN SECTIONS...AND KIPT HAS ALREADY DROPPED TO
MVFR...AND SPREAD INTO OTHER AREAS AS NIGHT PROGRESSES. SCT
SHOWERS WILL BECOME POSSIBLE IN THE VERY MOIST AIR OVER E PA AND
THE SUSQ VALLEY AFTER 08Z AS LARGE SCALE LIFT BEGINS TO
INCREASE...AND THESE SHOWERS ARE HINTED AT IN THE HRRR MODEL
FORECAST. SO ADDED VCSH TO EASTERN TERMINALS OVERNIGHT.
THEN FOCUS TURNS TO POTENT SFC COLD FRONT EXPECTED TO BE NEAR A
KBFD TO KJST LINE BY 12Z...AND PUSHING STEADILY EAST ACROSS THE
REST OF THE REGION DURING THE LATE MORNING AND EARLY AFTERNOON
HOURS. A NARROW LINE /ABOUT 4 HOURS/ OF HEAVY SHOWERS/LOW-TOPPED
TSRA SHOULD ACCOMPANY THE IMMEDIATE CFROPA...WHILE ISOLATED
SUPERCELLS ARE POSSIBLE WELL TO THE EAST OF THE FRONT IN THE
HIGHLY SHEARED ENVIRONMENT /MAINLY AFTER SUNRISE IN EASTERN
SECTIONS/. THESE INDIVIDUAL CELLS WILL TRACK RAPIDLY TO THE NE AT
40 KTS PLUS. ANY OF THESE LEAD STORMS /OR THE EXPECTED LINE ALONG
THE FRONT/ COULD MIX DOWN STRONG WIND GUSTS TO THE SFC.
CONDITIONS IMPROVE FROM WEST TO EAST WITHIN A FEW HOURS OF
FROPA AS PRECIP COMES TO AN END AND CEILINGS/VSBYS RETURN TO VFR
FOR THE SECOND HALF OF MON /AS RIDGING BEGINS IN LOWER LEVELS/.
WINDS TURN WESTERLY AND REMAIN AROUND 15 MPH GUSTING TO 25 MPH
BEFORE DIMINISHING LATER IN THE DAY.
CIG RESTRICTIONS LIKELY IN WESTERN/NORTHERN MTNS MON NIGHT AS
COLDEST MID LEVEL AIR RETREATS TO THE NE AND LOW LEVEL SUBSIDENCE
INVERSION SQUEEZES MOISTURE INTO A STABLE STRATOCU DECK.
OUTLOOK...
TUE...SCT AM SHOWERS/LOW CIGS POSSIBLE N AND W.
WED-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...DANGELO/CERU
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1206 AM EDT MON OCT 7 2013
.SYNOPSIS...
THE REGION REMAINS IN THE WARM SECTOR OF A LOW MOVING THROUGH THE
UPPER GR LAKES. THE ASSOCIATED COLD FRONT WILL MOVE THROUGH ON
MONDAY AS TROPICAL MOISTURE FLOWS UP INTO THE STATE. HIGH PRESSURE
IS EXPECTED TO RETURN FOR TUESDAY AND KEEP MAINLY FAIR WEATHER
OVER THE FORECAST AREA THROUGH THE REST OF THE NEW WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE COLD FRONT IS MOVING INTO EASTERN OHIO ACCOMPANIED BY AN AREA
OF HEAVY RAIN SHOWERS AND ISOLATED THUNDERSTORMS. LOCALLY...THE
CWA IS DRY AND QUITE MILD. HAVEN`T REALLY CHANGED MUCH OF THE
FORECAST DURING THE OVERNIGHT...STILL LOOKS GOOD FOR RAIN TO BE
MOVING INTO WESTERN AREAS AROUND OR SHORTLY AFTER 06Z...AND
SPREADING QUICKLY EAST AFTER THAT.
THE STRONG...SOUTHERLY LLJ WILL SHIFT EAST FROM THE OHIO VALLEY
AND INTO THE REGION OVERNIGHT. THIS WILL QUICKLY INCREASE SFC
WINDS...WITH THE HIGHER TERRAIN AND LOCATIONS NORTH OF GAPS IN THE
RIDGES SEEING WIND GUSTS OVER 30 MPH.
INCREASED LARGE SCALE LIFT ASSOCIATED WITH THIS LLJ AND A SERIES
OF UPPER SHORT WAVES LIFTING QUICKLY NNE AHEAD OF THE MAIN OHIO
VALLEY TROUGH AND SFC COLD FRONT WILL LEAD TO THE DEVELOPMENT OF
NUMEROUS SHOWERS AND EMBEDDED LOW TOPPED TSRA OVER THE WESTERN
PA AFTER MIDNIGHT. THIS CONVECTION MAY REACH THE I-99/RT 220
CORRIDOR BETWEEN 10-12Z MONDAY.
LOOK FOR ONE MORE NIGHT OF UNSEASONABLY MILD TEMPS WITH LOW IN THE
60-65F RANGE...THANKS TO SIMILARLY HIGH DEWPOINTS...AND THE
INCREASING CLOUDS/WIND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
THE MAIN ACTION OF THE WEEK AHEAD WILL BE CAPTURED IN THIS PERIOD AS
A RELATIVELY STRONG SFC COLD FRONT PUSHES EAST ACROSS THE
COMMONWEALTH. A HIGHLY ANOMALOUS SOUTHERLY LLJ /50KTS AND PLUS 3-4
SIGMA VIA THE 09Z AND 12Z SREF AND GEFS/ WILL SLIDE EAST ALONG AND
AHEAD OF THE FRONT MONDAY MORNING INTO EARLY MONDAY AFTERNOON.
EVEN THE SEEMINGLY HARMLESS /AND LOW/ FEW TO SEVERAL HUNDRED JOULES
OF SFC-BASED CAPE GENERATED IN THE MAINLY CLOUDY AIRMASS AHEAD OF
THE FRONT WILL BE ENOUGH TO COMBINE WITH THE STRONG DEEP-LAYER SHEAR
TO POSE THE THREAT FOR A NCFRB AND A FEW SWATHS OF STRONG/DAMAGING
STRAIGHT LINE WINDS.
THE SHARPLY VEERING AND VERY STRONG LLVL WIND PROFILE WILL ALSO
YIELD HIGH 0-3KM HELICITY OF 250-350 M2/S2...WHICH WILL BE CAPABLE
OF SUPPORTING SOME LOW-TOPPED AND FAST NEWD MOVING MINI SUPERCELLS
WELL AHEAD OF THE COLD FRONT /AND A FEW BKN-S SIGNATURES WITHIN THE
NCFRB/.
HIGH TEMPS WILL BE REACHED EARLY IN THE DAY ACROSS THE WEST...AND
EARLY AFTERNOON ACROSS THE SUSQ VALLEY WITH FEW TO SVRL DEG DIP IN
TEMPS BEHIND THE FRONT.
BEST WIND GUST POTENTIAL WILL BE ALONG AND AHEAD OF THE COLD FRONT
WITH A GUSTY /BUT NOT IMPRESSIVE/ WESTERLY FLOW BEHIND THE
FRONT.
STORM TOTAL RAINFALL WILL LIKELY RANGE FROM 1 TO 1.5 INCHES IN MOST
LOCATIONS...WHICH IS A DEFINITE DOWNWARD ADJUSTMENT FROM THE PAST
FEW DAYS GIVEN THE FACT THAT THERE WILL BE VERY LITTLE INFLUENCE
FROM THE REMNANTS OF TS KAREN THAT WILL WEAKEN FURTHER OVER THE NEXT
36 HOURS OVER THE SERN STATES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MODELS CONTINUE TO BE IN AGREEMENT WITH A NEARLY NEUTRAL TROUGH
EXTENDING FROM THE LOW CENTER THAT CONTINUES TO MOVE NORTHWARD.
COOLER AIR WILL ADVECT INTO THE REGION BEHIND THE FRONT MONDAY
NIGHT...AS ANY LINGERING SHOWERS SHOULD BE GONE BY 06Z TUESDAY.
THE PATTERN FLATTENS OUT QUICKLY TUESDAY MORNING AS SURFACE HIGH
PRESSURE SETTLES IN FOR THE LONG HAUL ON TUESDAY. THE UPPER RIDGE
RE-ASSERTS IT/S STRENGTH OVER THE ERN U.S. TEMPERATURES WILL BE
COOLER THAN NORMAL ON TUESDAY...WITH MORE SEASONABLE TEMPS THROUGH
THE REST OF THE WEEK. WITH THE DRY AIR AND SUBSIDENCE EVERY
MORNING...IT WILL BE A CLASSIC SET-UP FOR VERY CHILLY MORNINGS.
HOWEVER...THE ABNORMALLY HIGH 5H HEIGHTS...8H TEMPS OF 10 TO 12C AND
THICKNESSES IN THE MID 560S WILL PRECLUDE ALL BE THE VERY COLDEST
LOCATIONS FROM GETTING NEAR FREEZING AT NIGHT. THE COLDEST TIME
FRAME WILL BE TUESDAY NIGHT/WED MORNING. FROST IS POSSIBLE ACROSS
THE NORTH. RESIDUAL MOISTURE MOVING ONSHORE...ALONG WITH A WEAK SFC
LOW COULD ALLOW FOR EASTERLY FLOW LATE THURSDAY INTO FRIDAY.
THIS MOIST ONSHORE FLOW COULD BRING ISOLATED SHOWERS THURSDAY NIGHT
THROUGH FRIDAY AFTERNOON TO THE LOWER SUSQUEHANNA VALLEY.
THIS LOW PRESSURE SFC/ALOFT WILL CONTINUE TO DEVELOP OVER THE
WESTERN ATLANTIC UNDER THE UPPER RIDGE AND WILL CONTINUE TO
RETROGRADE INTO SATURDAY...BEFORE DRIFTING OUT TO SEA. HAVE
SLIGHTLY INCREASED POPS IN THE SOUTHEAST DURING THIS TIMEFRAME.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS ACROSS MAJORITY OF CENTRAL PA AT MIDNIGHT AS
REGION REMAINS IN WARM SECTOR...AWAITING ARRIVAL OF A COLD FRONT
LATER TONIGHT/EARLY MON. BIGGEST AVIATION CONCERN FOR NEXT SEVERAL
HOURS WILL BE A GUSTY S/SE WIND...WITH GUSTS PEAKING AT AROUND 25
MPH AT TIMES. MOIST FLOW IS ALLOWING A MARINE LAYER FROM THE
ATLANTIC TO PUSH NORTHWESTWARD ACROSS CWA...RAISING DEWPOINTS BY
NEARLY 10F. BIGGER IMPACTS OF THIS MARINE LAYER ARE BEGINNING TO
DEVELOP AS POTENT SOUTHERLY LOW-LEVEL JET SLIDES EAST FROM OHIO
VALLEY...PROVIDING THE LIFT TO INITIATE DEVELOPMENT OF AN MVFR/IFR
STRATOCU DECK. THESE CLOUDS WILL DEVELOP FIRST IN THE MOIST
AIRMASS OVER EASTERN SECTIONS...AND KIPT HAS ALREADY DROPPED TO
MVFR...AND SPREAD INTO OTHER AREAS AS NIGHT PROGRESSES. SCT
SHOWERS WILL BECOME POSSIBLE IN THE VERY MOIST AIR OVER E PA AND
THE SUSQ VALLEY AFTER 08Z AS LARGE SCALE LIFT BEGINS TO
INCREASE...AND THESE SHOWERS ARE HINTED AT IN THE HRRR MODEL
FORECAST. SO ADDED VCSH TO EASTERN TERMINALS OVERNIGHT.
THEN FOCUS TURNS TO POTENT SFC COLD FRONT EXPECTED TO BE NEAR A
KBFD TO KJST LINE BY 12Z...AND PUSHING STEADILY EAST ACROSS THE
REST OF THE REGION DURING THE LATE MORNING AND EARLY AFTERNOON
HOURS. A NARROW LINE /ABOUT 4 HOURS/ OF HEAVY SHOWERS/LOW-TOPPED
TSRA SHOULD ACCOMPANY THE IMMEDIATE CFROPA...WHILE ISOLATED
SUPERCELLS ARE POSSIBLE WELL TO THE EAST OF THE FRONT IN THE
HIGHLY SHEARED ENVIRONMENT /MAINLY AFTER SUNRISE IN EASTERN
SECTIONS/. THESE INDIVIDUAL CELLS WILL TRACK RAPIDLY TO THE NE AT
40 KTS PLUS. ANY OF THESE LEAD STORMS /OR THE EXPECTED LINE ALONG
THE FRONT/ COULD MIX DOWN STRONG WIND GUSTS TO THE SFC.
CONDITIONS IMPROVE FROM WEST TO EAST WITHIN A FEW HOURS OF
FROPA AS PRECIP COMES TO AN END AND CEILINGS/VSBYS RETURN TO VFR
FOR THE SECOND HALF OF MON /AS RIDGING BEGINS IN LOWER LEVELS/.
WINDS TURN WESTERLY AND REMAIN AROUND 15 MPH GUSTING TO 25 MPH
BEFORE DIMINISHING LATER IN THE DAY.
CIG RESTRICTIONS LIKELY IN WESTERN/NORTHERN MTNS MON NIGHT AS
COLDEST MID LEVEL AIR RETREATS TO THE NE AND LOW LEVEL SUBSIDENCE
INVERSION SQUEEZES MOISTURE INTO A STABLE STRATOCU DECK.
OUTLOOK...
TUE...SCT AM SHOWERS/LOW CIGS POSSIBLE N AND W.
WED-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...DANGELO/CERU
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
503 AM EDT MON OCT 7 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA TODAY. ABUNDANT MOISTURE AND
STRONG UPPER LEVEL WINDS WILL PROVIDE FOR HEAVY RAIN AND POSSIBLE
SEVERE WEATHER ACROSS THE REGION. HIGH PRESSURE BUILDS BACK IN
TUESDAY LASTING THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
445 AM UPDATE...EARLY THIS MORNING...COLD FROPA IMMINENT WITH SFC
TROUGH AND CONVERGENCE LINE NOW EVIDENTLY JUST EAST OF THE TENN/NC
BORDER. SHORTWAVE IMPULSE LEADING THE CORE OF THE UPPER TROUGH IN
THE MODERATELY UNSTABLE ENVIRONMENT AHEAD OF THE FRONT CONTINUES
TO SUPPORT A FEW TSTMS...THE QLCS WHICH MOVED THRU THE FOOTHILLS
EARLIER THIS AM HAVING BECOME DISORGANIZED. STRONG LLVL SHEAR
STILL PRESENT AND THOUGH RAP ANALYSIS STILL INDICATES SOME
INSTABILITY LAPSE RATES MAY HAVE BECOME NEARLY NEUTRAL/MOIST
ADIABATIC WITH THE COLUMN SATURATING.
THE SHORTWAVE IS STILL MOVING INTO A MORE UNSTABLE ENVIRONMENT...ONE
THAT HAS LARGELY BEEN UNTOUCHED TONIGHT. THUS DEVELOPMENT OF
DISCRETE CONVECTION...MOSTLY SHOWERS WITH A LESSER NUMBER OF
TSTMS...MAY STILL BE EXPECTED THIS MRNG EAST OF A GREENWOOD TO
STATESVILLE LINE. TEMPS WILL LIKELY REMAIN NEARLY STEADY THRU
DAYBREAK...EXCEPT IN THE HIGHER MTNS WHICH MAY SEE SOME COOLER AIR
BEGIN TO FILTER IN.
TODAY...BOTH SYNOPTIC MODELS AND CAM CONSENSUS SHOW THE FRONT EXITING
THE ERN PERIPHERY OF THE CWFA IN 18-21Z TIMEFRAME. PROG SOUNDINGS
FROM CLT/HKY INDICATE MODEST INSTABILITY STILL PRESENT IN THE NC
PIEDMONT AT THAT TIME SO I ALLOWED POPS TO DROP OFF MORE QUICKLY IN
THE WEST WHERE THE FROPA WILL OCCUR EARLIER...HOLDING ONTO LIKELY
POPS EAST THRU PEAK HEATING. HIGHS TODAY HAVE BEEN HELD CLOSE TO A
CONSENSUS OF RAW MODEL TEMPS...WITH CLOUDY CONDITIONS EXPECTED TO
PERSIST MOST OF THE DAY.
TONIGHT...LATEST COUPLE MODEL CYCLES HAVE DECLINED TO DRY THINGS OUT
TOTALLY IN THE WAKE OF THE FRONT...RATHER FEATURING A FRONTAL WAVE
DEVELOPING NEAR THE SC/GA COAST AND SOME RETURNING MOISTURE OVERNIGHT
TONIGHT. THIS WAS HINTED AT FIRST BY THE EC A COUPLE DAYS AGO AND
OTHER MODELS GRADUALLY BOUGHT INTO THIS IDEA. IN LIGHT OF THE TREND I
ALLOWED POPS TO RISE AGAIN SOUTH/EAST OF I-85 TONIGHT. TEMPS WILL BE
NOTICEABLY COOLER...ESPECIALLY IN THE MTNS WHERE THE COOL AND DRY AIR
WILL ALREADY BE IN PLACE THIS EVENING. EVEN IN THE AFOREMENTIONED
AREA OF MORE CLOUDS AND POPS LOWS IN THE MID TO UPPER 50S ARE
EXPECTED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM MONDAY...MAJOR CHANGE IN THE FORECAST DURING THIS
PERIOD AS ALL GUIDANCE POINTS TO AN UPPER LOW...THE REMNANTS OF
KAREN...DETACHING FROM THE FULL LATITUDE TROF OVER THE ERN CONUS
AND SLOWLY MOVING NORTH FROM THE GULF COAST ACROSS THE SERN CONUS.
AT THE SFC...THE LOW PRESSURE AREA THAT IS THE REMNANTS OF KAREN
DETACHES FROM THE COLD FRONT AND SLOWLY MOVES UP THE ATLANTIC
COAST. WITH HIGH PRESSURE CENTERED OVER NEW ENGLAND IN A DAMMING
CONFIGURATION...THE ELY LOW LEVEL FLOW AROUND THESE TWO SYSTEMS
INCREASES AND BRINGS QUITE A BIT OF MOISTURE INTO THE AREA.
ISENTROPIC LIFT WILL BE WEAK...BUT STRONG ENUF TO BRING CLOUDS AND
PRECIP EAST TO WEST ACROSS THE CWFA TUE AND TUE NITE. THE FLOW
BECOMES A LITTLE MORE NLY WED AND WED NITE AND MOISTURE SLOWLY PULLS
OUT OF THE AREA AS THE LOW MOVES UP THE COAST. THIS MEANS
DIMINISHING POP FROM WEST TO EAST WED AND WED NITE. FOR NOW...IT
APPEARS PRECIP WILL BE LIGHT WITH THE BEST CHC ALONG AND SOUTH OF
I-85 IN NE GA AND THE UPSTATE...AND OVER THE FOOTHILLS AND PIEDMONT
IN NC. BREEZY TO POSSIBLY WINDY CONDITIONS ARE EXPECTED THRU THE
PERIOD AS THE PRESSURE GRADIENT TIGHTENS BETWEEN THE LOW AND HIGH.
MUCH MORE CLOUDINESS IS EXPECTED AS WELL. THE COMBINATION OF CLOUDS
AND PRECIP WILL BRING HIGHS GENERALLY IN THE LOW TO MID 60S...WITH
SOME UPPER 60S POSSIBLE IN THE FAR WRN CWFA. LOWS IN THE LOW TO MID
50S TUE NITE FALL TO THE UPPER 40S TO LOWER 50S WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 AM MON...THE UPPER LOW FEATURED IN THE SHORT RANGE FCST
SLOWLY MOVES EAST ACROSS NC/VA THEN OFF SHORE BY SUN. SOME WEAK
RIDGING BUILDS IN BEHIND THE LOW AS SHORT WAVES MOVE UP THE RIDGE
AND ACROSS THE OH VALLEY. AT THE SFC...THE COASTAL LOW CONTINUES ITS
TREK UP THE EAST COAST AS THE DAMMING SFC HIGH WEAKENS. A DRIER N TO
NWLY FLOW SETS UP AS THIS SYSTEM MOVES OUT OF THE AREA. THE GFS THEN
TRIES TO BRINGS MOISTURE AND PRECIP BACK INTO THE AREA FROM THE NE
BY THE WEEKEND AS ELY FLOW STRENGTHENS. THE CANADIAN AND THE ECMWF
ARE MUCH WEAKER WITH THE FLOW AND ANY MOISTURE. THEREFORE...HAVE
KEPT THE FCST DRY FOR NOW. HIGHS START OUT A LITTLE BELOW NORMAL
THEN QUICKLY RISE TO NEAR NORMAL AND REMAIN NEARLY STEADY THRU THE
NED OF THE PERIOD. LOWS START OUT NEAR NORMAL THEN RISE A FEW
DEGREES BY THE EN OF THE PERIOD.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AT KCLT /09Z UPDATE/...COLD FRONT WILL MOVE THROUGH THE AREA EARLY
THIS AFTN...PRECEDED BY SHRA/TSRA. A LINE OF HEAVY SHRA WITH A
COUPLE EMBEDDED TSRA MAY BRING A PERIOD OF IFR CIGS/VSBY TO THE
FIELD AROUND OR JUST AFTER DAYBREAK...BUT WITH MOST OF THE
CONVECTION MOVING PARALLEL TO THE WHOLE LINE IT IS MOVING SLOWLY AND
EITHER MAY NOT MAKE IT TO KCLT OR ARRIVE AFTER MORNING MIXING BEGINS.
CHANCES WARRANT A TEMPO. MVFR CIG EXPECTED TO PERSIST UNTIL THE
FROPA LIFTS THEM TO VFR AND STARTS A CLEARING TREND THIS AFTN.
UNSTABLE ENVIRONMENT ALONG WITH UPPER ENERGY PASSING OVERHEAD MAY
ALLOW DISCRETE SHRA OR TSRA CAUSING BRIEF RESTRICTIONS UNTIL THEN.
GENERALLY SOUTHERLY WINDS WILL FLIP TO NW FOLLOWING THE
FROPA...BEFORE VEERING NE LATE IN THE PERIOD.
ELSEWHERE...MUCH LIKE KCLT BUT WITH FROPA AND NLY WIND SHIFT
ARRIVING EARLIER. IT IS EXPECTED JUST AFTER DAYBREAK IN THE
MTNS...LATE MRNG FOOTHILLS AND UPPER PIEDMONT...EARLY AFTN
ELSEWHERE. STRATIFORM RAIN AND WIDELY SCATTERED HEAVY SHRA/TSRA WILL
REMAIN IN SOME FORM BEFORE THE FROPA. VFR CONDITIONS SHOULD RETURN
TO ALL SITES THIS AFTERNOON WITH THE WRN SITES POSSIBLY LOSING CIG
ALTOGETHER BEFORE 00Z.
OUTLOOK...DRY AND COOL HIGH PRESSURE BUILDS IN MON NITE AND
CONTINUES THRU THE WEEK. RESTRICTIONS SHUD BE LIMITED TO MORNING MTN
VALLEY FOG.
CONFIDENCE TABLE...
09-15Z 15-21Z 21-03Z 03-09Z
KCLT MED 78% HIGH 81% HIGH 82% HIGH 100%
KGSP HIGH 81% MED 68% HIGH 92% HIGH 100%
KAVL MED 77% MED 79% HIGH 100% HIGH 100%
KHKY HIGH 83% MED 74% HIGH 100% HIGH 100%
KGMU HIGH 84% MED 78% HIGH 92% HIGH 100%
KAND MED 76% MED 74% HIGH 93% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
337 AM EDT MON OCT 7 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA TODAY. ABUNDANT MOISTURE AND
STRONG UPPER LEVEL WINDS WILL PROVIDE FOR HEAVY RAIN AND POSSIBLE
SEVERE WEATHER ACROSS THE REGION. HIGH PRESSURE BUILDS BACK IN
TUESDAY LASTING THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...COLD FROPA IMMINENT WITH SFC TROUGH AND
CONVERGENCE LINE EXTENDING DOWN THE SPINE OF THE APPALACHIANS.
SHORTWAVE IMPULSE LEADING THE CORE OF THE UPPER TROUGH IN THE
MODERATELY UNSTABLE ENVIRONMENT AHEAD OF THE FRONT CONTINUES TO
SUPPORT TSTMS...MOST NOTABLY A LOW END QLCS MOVING INTO THE NC
PIEDMONT AND NERN UPSTATE ZONES. THIS REFLECTS THE STRONG SHEAR...20
KT 0-1KM WITH 0-3KM HELICITY OF OVER 200 M2/S2. SPC MESOANALYSIS
SHOWS THE LINE ENTERING HIGHER SFC BASED CAPE OVER THE ERN
PIEDMONT...THOUGH AS NOTED BY PREVIOUS SHIFTS THE JUICIEST VALUES
WILL REMAIN FURTHER SOUTH.
LATEST 04Z HRRR INDICATES SOME NEW DEVELOPMENT ALONG THE SRN END OF
THIS LINE AS INDIVIDUAL CONVECTIVE ELEMENTS MOVE NORTHEAST...AND THIS
MATCHES RADAR TRENDS OVER THE PAST HOUR OR SO. THE UNIDIRECTIONAL
SHEAR AND STRONG MIDLEVEL WINDS ARE ALLOWING FOR TRAINING TO OCCUR
THERE ALSO...AND THIS APPEARS TO BE THE MAIN HYDRO CONCERN AT THIS
TIME. THE LINE LOOKS TO GRADUALLY SHIFT EASTWARD OVER THE PIEDMONT
THRU DAYBREAK. DISCRETE CONVECTIVE ACTIVITY EARLIER THIS EVENING NEAR
THE CHARLOTTE METRO DID DIMINISH...BUT THE ENVIRONMENT SEEMS TO BE
PRIMED FOR REDEVELOPMENT AS THE SHORTWAVE MOVES IN LATER.
TODAY...BOTH SYNOPTIC MODELS AND CAM CONSENSUS SHOW THE FRONT EXITING
THE ERN PERIPHERY OF THE CWFA IN 18-21Z TIMEFRAME. PROG SOUNDINGS
FROM CLT/HKY INDICATE MODEST INSTABILITY STILL PRESENT IN THE NC
PIEDMONT AT THAT TIME SO I ALLOWED POPS TO DROP OFF MORE QUICKLY IN
THE WEST WHERE THE FROPA WILL OCCUR EARLIER...HOLDING ONTO LIKELY
POPS EAST THRU PEAK HEATING. HIGHS TODAY HAVE BEEN HELD CLOSE TO A
CONSENSUS OF RAW MODEL TEMPS...WITH CLOUDY CONDITIONS EXPECTED TO
PERSIST MOST OF THE DAY.
TONIGHT...LATEST COUPLE MODEL CYCLES HAVE DECLINED TO DRY THINGS OUT
TOTALLY IN THE WAKE OF THE FRONT...RATHER FEATURING A FRONTAL WAVE
DEVELOPING NEAR THE SC/GA COAST AND SOME RETURNING MOISTURE OVERNIGHT
TONIGHT. THIS WAS HINTED AT FIRST BY THE EC A COUPLE DAYS AGO AND
OTHER MODELS GRADUALLY BOUGHT INTO THIS IDEA. IN LIGHT OF THE TREND I
ALLOWED POPS TO RISE AGAIN SOUTH/EAST OF I-85 TONIGHT. TEMPS WILL BE
NOTICEABLY COOLER...ESPECIALLY IN THE MTNS WHERE THE COOL AND DRY AIR
WILL ALREADY BE IN PLACE THIS EVENING. EVEN IN THE AFOREMENTIONED
AREA OF MORE CLOUDS AND POPS LOWS IN THE MID TO UPPER 50S ARE
EXPECTED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM MONDAY...MAJOR CHANGE IN THE FORECAST DURING THIS
PERIOD AS ALL GUIDANCE POINTS TO AN UPPER LOW...THE REMNANTS OF
KAREN...DETACHING FROM THE FULL LATITUDE TROF OVER THE ERN CONUS
AND SLOWLY MOVING NORTH FROM THE GULF COAST ACROSS THE SERN CONUS.
AT THE SFC...THE LOW PRESSURE AREA THAT IS THE REMNANTS OF KAREN
DETACHES FROM THE COLD FRONT AND SLOWLY MOVES UP THE ATLANTIC
COAST. WITH HIGH PRESSURE CENTERED OVER NEW ENGLAND IN A DAMMING
CONFIGURATION...THE ELY LOW LEVEL FLOW AROUND THESE TWO SYSTEMS
INCREASES AND BRINGS QUITE A BIT OF MOISTURE INTO THE AREA.
ISENTROPIC LIFT WILL BE WEAK...BUT STRONG ENUF TO BRING CLOUDS AND
PRECIP EAST TO WEST ACROSS THE CWFA TUE AND TUE NITE. THE FLOW
BECOMES A LITTLE MORE NLY WED AND WED NITE AND MOISTURE SLOWLY PULLS
OUT OF THE AREA AS THE LOW MOVES UP THE COAST. THIS MEANS
DIMINISHING POP FROM WEST TO EAST WED AND WED NITE. FOR NOW...IT
APPEARS PRECIP WILL BE LIGHT WITH THE BEST CHC ALONG AND SOUTH OF
I-85 IN NE GA AND THE UPSTATE...AND OVER THE FOOTHILLS AND PIEDMONT
IN NC. BREEZY TO POSSIBLY WINDY CONDITIONS ARE EXPECTED THRU THE
PERIOD AS THE PRESSURE GRADIENT TIGHTENS BETWEEN THE LOW AND HIGH.
MUCH MORE CLOUDINESS IS EXPECTED AS WELL. THE COMBINATION OF CLOUDS
AND PRECIP WILL BRING HIGHS GENERALLY IN THE LOW TO MID 60S...WITH
SOME UPPER 60S POSSIBLE IN THE FAR WRN CWFA. LOWS IN THE LOW TO MID
50S TUE NITE FALL TO THE UPPER 40S TO LOWER 50S WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 AM MON...THE UPPER LOW FEATURED IN THE SHORT RANGE FCST
SLOWLY MOVES EAST ACROSS NC/VA THEN OFF SHORE BY SUN. SOME WEAK
RIDGING BUILDS IN BEHIND THE LOW AS SHORT WAVES MOVE UP THE RIDGE
AND ACROSS THE OH VALLEY. AT THE SFC...THE COASTAL LOW CONTINUES ITS
TREK UP THE EAST COAST AS THE DAMMING SFC HIGH WEAKENS. A DRIER N TO
NWLY FLOW SETS UP AS THIS SYSTEM MOVES OUT OF THE AREA. THE GFS THEN
TRIES TO BRINGS MOISTURE AND PRECIP BACK INTO THE AREA FROM THE NE
BY THE WEEKEND AS ELY FLOW STRENGTHENS. THE CANADIAN AND THE ECMWF
ARE MUCH WEAKER WITH THE FLOW AND ANY MOISTURE. THEREFORE...HAVE
KEPT THE FCST DRY FOR NOW. HIGHS START OUT A LITTLE BELOW NORMAL
THEN QUICKLY RISE TO NEAR NORMAL AND REMAIN NEARLY STEADY THRU THE
NED OF THE PERIOD. LOWS START OUT NEAR NORMAL THEN RISE A FEW
DEGREES BY THE EN OF THE PERIOD.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AT KCLT...COLD FRONT WILL MOVE THROUGH THE AREA EARLY THIS
AFTN...PRECEDED BY SHRA/TSRA. AN ORGANIZED LINE OF TSRA WILL MOVE
THRU UPSTATE SC AND THE SRN NC PIEDMONT EARLY THIS AM. THIS LINE IS
LIKELY TO BRING A PERIOD OF IFR CIGS/VSBY TO AFFECTED
LOCATIONS...BUT TO HAVE A DIRECT IMPACT IT WILL HAVE TO BUILD ON ITS
SRN END. WESTERLY GUSTS OF 15-20KT ALSO LIKELY ALONG THIS LINE.
INDEED THE LINE MAY TRANSLATE NORTH OF THE FIELD...BUT CHANCES
WARRANT A TEMPO. NONETHELESS...UNSTABLE ENVIRONMENT ALONG WITH UPPER
ENERGY MAY ALLOW DISCRETE SHRA OR TSRA CAUSING BRIEF RESTRICTIONS
UNTIL THE FRONT PUSHES THRU...WHEN VFR CONDITIONS RETURN. GENERALLY
SOUTHERLY WINDS WILL FLIP TO NW FOLLOWING THE FROPA...BEFORE VEERING
NE LATE IN THE PERIOD.
ELSEWHERE...MORE OR LESS LIKE KCLT THOUGH TIMING EARLIER IN MOST
REGARDS. MOST ORGANIZED CONVECTION WILL PUSH EAST OF KGSP/KGMU
WITHIN THE FIRST COUPLE HRS OF THE TAF. STRATIFORM RAIN AND WIDELY
SCATTERED HEAVY SHRA/TSRA WILL REMAIN IN SOME FORM OVERNIGHT.
ANOTHER CLUSTER OF STORMS MAY AFFECT KAVL TOWARD DAYBREAK FOLLOWING
AN EARLY MORNING LULL. VFR CONDITIONS SHOULD RETURN TO ALL SITES
THIS AFTERNOON WITH THE WRN SITES POSSIBLY LOSING CIG ALTOGETHER
BEFORE 00Z.
OUTLOOK...DRY AND COOL HIGH PRESSURE BUILDS IN MON NITE AND
CONTINUES THRU THE WEEK. RESTRICTIONS SHUD BE LIMITED TO MORNING MTN
VALLEY FOG.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-07Z
KCLT HIGH 86% HIGH 95% MED 76% HIGH 100%
KGSP HIGH 94% MED 77% MED 79% HIGH 100%
KAVL HIGH 93% MED 66% HIGH 100% HIGH 100%
KHKY HIGH 88% MED 78% HIGH 94% HIGH 100%
KGMU HIGH 93% HIGH 82% MED 78% HIGH 100%
KAND HIGH 85% MED 77% HIGH 85% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1145 PM CDT SUN OCT 6 2013
.UPDATE...FOR AVIATION.
&&
.AVIATION...
06Z TAFS...COLD FRONT HAS MOVED THROUGH THE AREA WITH FEW SHRA
LINGERING AROUND CSV. CSV WILL HAVE SHRA ENDING BY 09Z WITH SOME
FOG AND LOW CLOUDS POSSIBLE THROUGH THE REST OF THE NIGHT.
FOR BNA AND CKV...DRIER AIR AND CLEARING IS MOVING IN BEHIND THE
FRONT...BUT SOME MVFR FOG MAY DEVELOP TOWARD DAYBREAK. HIGH
PRESSURE WILL DOMINATE DAYTIME MONDAY...WITH EXCELLENT VSBY...
SCT CU AROUND 4 KFT AND NNW WINDS NEAR 10KT.
13
&&
.PREV DISCUSSION... /ISSUED 721 PM CDT SUN OCT 6 2013/
UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REMOVE THE
THROUGH LATE AFTERNOON WORDING AND TO TAILOR SHWRS PRESENTLY
MAINLY E OF I-65 TO CONTINUE SLOWING MOVING EWD OUT OF MID STATE
WITH SHWRS CONTINUING ACROSS THE PLATEAU COUNTIES ONLY GENERALLY
AFTER MIDNIGHT. HAVE TAILORED SKY CONDITIONS ALSO TO REFLECT
DECREASING CLOUDINESS W TO E ACROSS THE MID STATE AS THE NIGHT
TIME HRS PROGRESS. CURRENT TEMPS IN LINE WITH FORECASTED LOW
VALUES AS OF THIS TIME...THUS NO ADJUSTMENTS MADE TO OVERNIGHT
LOW VALUES AS OF THIS TIME.
31
PREV DISCUSSION... /ISSUED 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.
31
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.
ROSE
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1000 AM EDT Mon Oct 7 2013
.NEAR TERM [Rest of Today]...
---Updated at 10:00 AM EDT---
The remnant low formerly known as "Karen" was located about 30 miles
or so south-southeast of St. George Island as of 13 UTC. The low
will continue to slowly shift east today to near the mouth of the
Suwannee River by late afternoon. A synoptic cold front was not
situated far behind - roughly from Macon to Panama City - but there
was a distinct gap between the remnant low and the cold front.
Aloft, a subtle but potent upper level PV anomaly was moving east
near the mouth of the Mississippi River. Linear extrapolation and
the latest RAP runs push the upper level wave into the western part
of our area closer to 00 UTC. The approach of stronger upper level
forcing from the west yet to arrive, as diagnosed well by the
previous shift, should be able to generate some surface response.
Even some minor pressure falls would be sufficient to temporarily
delay or stall the eastward motion of the cold front.
The result will be a fairly deep deformation zone (900-500mb) over
the area that will be very slow to pivot east today. This should
help maintain sufficient forcing for continued cloud cover and
showers through the day - particularly in the eastern half of our
area, and especially when you consider the 2.04" PWAT on the morning
sounding from our office (close to +2 std. deviations above normal,
or about 175% of normal). Therefore, high PoPs and cloud cover were
maintained over the eastern portions of our area. High temperatures
were adjusted to fit closer to raw model guidance, and in particular
the average of the last few runs of the HRRR. This yields upper 70s
in most locations, although some spots that see more regular breaks
of sun could reach 80-82 degrees.
&&
.SHORT TERM [Tonight Through Wednesday]...
As the primary upper trough lifts northeast into Canada tonight,
a southern shortwave over the Gulf of Mexico will slide east and
cutoff a weak upper low over north florida. This upper low will
lift slowly northward into the central Appalachians through
Wednesday. At the surface, the area of low pressure currently over
the northeastern Gulf will move slowly across northeast tonight
into Tuesday, before moving northeastward off the coast Tuesday
night into Wednesday. High pressure, centered over New England
will nose southward to the Gulf Coast behind the surface low.
This evolution will prevent low-level dry air from pushing into
much of the region over the next few days, keeping plenty of
clouds in place. In addition, showers are expected to develop
within the cool northeasterly flow in the wake of the surface low,
aided by the upper level low. Thus, for Tuesday, have lowered high
temperatures and raised PoPs, especially for southwest and south
central Georgia. The support for rain should diminish into
Wednesday. However, the low-level moisture will be slow to scour
out, with low clouds and cooler temperatures lingering.
&&
.LONG TERM [Wednesday Night through Sunday]...
In general there is good model agreement for this period with
quiet weather and temperatures near or slightly below climatology.
Expect dry conditions with highs in the low to mid 80s and
overnight lows in the mid 50s to mid 60s.
&&
.AVIATION [through 12 UTC Tuesday]...
---Updated at 10:00 AM EDT---
A patch of IFR CIGS was persisting in portions of SE Alabama and the
western Florida Panhandle as of 14 UTC, roughly centered on DHN. ECP
was on the southern periphery. This could linger until around 17-18
UTC, when guidance suggests clouds will lift and scatter out. These
TAFs will be amended to account for that cloud layer. Elsewhere,
MVFR ceilings and periodic -SHRA will prevail at ABY, TLH, VLD.
&&
.MARINE...
---Updated at 10:00 AM EDT---
The remnant low has shifted into the section of the coastal waters
east of Apalachicola. Observations and the consensus of all models
is that winds will be weaker immediately near the low, and be
stronger on the back side of the low (and behind a nearby cold
front). With this in mind, we will be converting the eastern waters
to a SCEC headline for some patches of 15-20 knot winds today, and
more widespread 15-20 knot winds tonight. The western waters will
have a Small Craft Advisory through 06 UTC for the stronger north
winds behind the low.
&&
.FIRE WEATHER...
Relative humidity values will remain above critical levels for the
foreseeable future. Thus, hazardous fire weather conditions are not
anticipated.
&&
.HYDROLOGY...
While localized heavy rain will be possible through this
afternoon, primarily across the eastern half of the area, most
areas will see less than an inch. This should have little impact
on area rivers and streams.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 79 65 82 61 80 / 60 30 30 10 10
Panama City 79 64 82 64 81 / 30 10 10 10 10
Dothan 77 59 79 58 78 / 50 20 30 10 10
Albany 78 64 75 58 75 /100 30 40 20 10
Valdosta 80 66 78 59 75 / 70 40 50 20 10
Cross City 80 67 85 62 82 / 70 40 30 10 10
Apalachicola 82 67 80 65 80 / 60 10 20 10 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...SMALL CRAFT ADVISORY until 2 AM EDT Tuesday morning for
coastal waters west of Apalachicola, out to 60 NM.
&&
$$
NEAR TERM...Lamers
SHORT TERM...Camp
LONG TERM...Hollingsworth
AVIATION...Lamers
MARINE...Lamers
FIRE WEATHER...Harrigan
HYDROLOGY...Camp
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
728 AM EDT MON OCT 7 2013
.SYNOPSIS...
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY AHEAD OF A
STRONG COLD FRONT WHICH WILL CROSS LATE TONIGHT. A WAVE OF LOW
PRESSURE WILL DEVELOP ALONG THIS FRONT AND MOVE NEAR THE AREA
TUESDAY AND WEDNESDAY...PRODUCING WIDESPREAD RAIN AND MUCH COOLER
TEMPERATURES. A DRYING AND WARMING TREND WILL BEGIN LATE IN THE
WEEK AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 AM MONDAY...RADAR TRENDS AND THE LATEST HRRR MODEL
SUGGESTS THE CONVEYOR BELT OF SHOWERS WILL CONTINUE MOVING ACROSS
EASTERN SOUTH CAROLINA AND THE LUMBERTON AREA FOR AT LEAST THE
REMAINDER OF THE MORNING HOURS...GRADUALLY SHIFTING EAST TO INCLUDE
THE MYRTLE BEACH-WHITEVILLE-ELIZABETHTOWN CORRIDOR BEFORE NOON.
UNLESS ISOLATED CELLS DEVELOP OUT AHEAD OF THE MAIN LINE IT COULD BE
AS LATE AS 4 PM BEFORE WILMINGTON GETS IN ON THE ACTION. NO CHANGES
HAVE BEEN MADE TO TEMPERATURES. PREVIOUS DISCUSSION FROM 300 AM
FOLLOWS...
A STREAM OF SHOWERS ORIGINATING FROM THE GULF STREAM WATERS OFF THE
GA/FL COAST CONTINUES TO MOVE NORTH INTO EASTERN SC EARLY THIS
MORNING. SYNOPTIC MODELS 24 HOURS AGO WERE NOT ABLE TO CAPTURE THIS
FEATURE...BUT RECENT HIGH-RESOLUTION MODELS LIKE THE HRRR AND NSSL
WRF SEE IT WELL AND INDICATE THE "STREAMER" WILL CONTINUE THROUGH
THE MORNING HOURS WITH SIGNIFICANT RAINFALL TOTALS POSSIBLE ACROSS
EASTERN SOUTH CAROLINA.
STRONG UPPER LEVEL LOW PRESSURE ACROSS THE SOUTHERN GREAT LAKES IS
THE SAME SYSTEM RESPONSIBLE FOR THE RECORD-BREAKING EARLY SNOW
ACROSS WESTERN SOUTH DAKOTA A COUPLE DAYS AGO. THIS UPPER SYSTEM
WILL LIFT NORTHEAST...WHILE A VORTICITY MAXIMUM AT THE BASE OF THE
UPPER TROUGH ALONG THE GULF COAST SLOWS AND BEGINS TO FORM A CLOSED
LOW LATE TONIGHT. THE SURFACE PATTERN MIRRORS THE 500 MB CHART WITH
AN EASTWARD-MOVING COLD FRONT LOCATED JUST AHEAD OF THE UPPER
TROUGH. THIS FRONT WILL SLOW ITS PROGRESS AS SURFACE LOW PRESSURES
DEVELOPS IN IN THE FLORIDA PANHANDLE.
SHOWER AND T-STORM CHANCES ARE VERY HIGH TODAY...PROBABLY AT LEAST
90 PERCENT COVERAGE ACROSS THE EASTERN CAROLINAS. THIS MORNING`S
HEAVY BAND OF SHOWERS ACROSS EASTERN SOUTH CAROLINA SHOULD SOAK THE
PEE DEE AND INTERSTATE 95 CORRIDOR THROUGH MID-MORNING...SHIFTING
EAST FROM MYRTLE BEACH THROUGH WHITEVILLE AND ELIZABETHTOWN BY
NOON...THEN FINALLY REACHING THE CAPE FEAR AREA INCLUDING WILMINGTON
BY THE MID-AFTERNOON HOURS. FROM A BROAD-SCALE PERSPECTIVE MANY
AREAS SHOULD SEE TWO-THIRDS TO ONE INCH OF RAIN TODAY...BUT WITH
TRAINING CONVECTION UNDOUBTEDLY A FEW SPOTS WILL RECEIVE 2-3 INCHES
OR MORE. SEVERE WEATHER POTENTIAL IS NOT ZERO...BUT IS LESS THAN
EXPECTED YESTERDAY DUE TO WEAKENING LOW-LEVEL WIND FIELDS AND
OVERALL MODEST INSTABILITY. IN FACT IT APPEARS ISOLATED FLOODING MAY
BECOME A LARGER FACTOR TO CONTEND WITH THAN SEVERE WEATHER. SHOULD A
THUNDERSTORM BECOME SEVERE TODAY...WET MICROBURSTS APPEAR TO BE THE
MOST SIGNIFICANT THREAT.
TONIGHT THE PRESSURE GRADIENT BETWEEN THE LOW OVER NORTHERN FLORIDA
AND HIGH PRESSURE STRENGTHENING OVER PENNSYLVANIA SHOULD PRODUCE A
NORTHERLY SURGE THAT WILL REACH OUR AREA A FEW HOURS BEFORE SUNRISE.
THIS SHALLOW COLD AIRMASS WILL UNDERCUT THE OTHERWISE WARM AND HUMID
AIR PRESENT...PRODUCING GUSTY WINDS AND SUDDENLY FALLING
TEMPERATURES. PRECIPITATION CHANCES WILL CONTINUE AS WELL...
ESPECIALLY ALONG THE COAST...BUT ISENTROPIC PROCESSES WILL BECOME
MORE DOMINANT WITH TIME AS INSTABILITY WANES AND VEERING LOW LEVEL
WINDS ADVECT ATLANTIC MOISTURE BACK ONSHORE. POPS TONIGHT RANGE FROM
80 PERCENT ALONG THE COAST TO 60 PERCENT IN FLORENCE AND DARLINGTON.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...SLOW MOVING UPPER LOW WILL EJECT OUT OF THE
GULF OF MEXICO AND DRIFT NORTHEAST THROUGH THE PERIOD...SPAWNING A
WAVE OF LOW PRESSURE ALONG A COLD FRONT STALLED ON THE COAST.
STRONG VORT MAX ACROSS SOUTHEAST TEXAS WILL MOVE INTO THE GULF AND
THEN DRIFT NORTHEAST OVERHEAD THE CAROLINAS TUESDAY AND WEDNESDAY.
THIS SPAWNS A SURFACE WAVE ALONG A COLD FRONT WHICH WILL BE STALLED
RIGHT ON THE COAST...AND WILL KEEP UNSETTLED WEATHER THROUGH THE
PERIOD. GUIDANCE IS IN GOOD AGREEMENT THAT BOTH TUESDAY AND
WEDNESDAY WILL BE WET...A SIGNIFICANT CHANGE FROM MODELS LAST NIGHT.
AS THE FRONT STALLS JUST OFFSHORE...ABUNDANT TROPICAL MOISTURE
REMAINS IN PLACE. THIS SERVES AS THE FUEL FOR PERIODS OF MDT/HVY
RAIN TUE AND WED AS THE UPPER LOW MOVES OVERHEAD.
ADDITIONALLY...ISENTROPIC LIFT OVER THE DEVELOPING WEDGE-HIGH
PRESSURE WILL ENHANCE RAINFALL...ESPECIALLY ACROSS EASTERN PORTIONS
OF THE CWA. WPC IS SHOWING WIDESPREAD 1-2 INCHES OF QPF...MOST
ACROSS THE CAPE FEAR REGION TUE/WED. THIS MAY BE A BIT HIGH...BUT
CERTAINLY SHOWS THE POTENTIAL WITHIN THE TROPICAL MOISTURE PLUME.
IN ADDITION TO THE UNSETTLED WEATHER...TEMPS WILL BE WELL BELOW
NORMAL BOTH TUE AND WED THANKS TO THE WEDGE HIGH PRESSURE AND
CLOUDS/RAIN.
STRONG LOW LVL CAA DEVELOPS EARLY TUESDAY...AND HAVE
SHOWN AN ATYPICAL DIURNAL CURVE WITH MAX TEMPS BEING REACHED FIRST
THING TUESDAY MORNING...BEFORE FALLING THROUGH THE DAY. HIGHS ON
TUESDAY WILL REACH ONLY THE MID/UPR 60S...AGAIN...EARLY IN THE
DAY...AND THEN FALL INTO THE LOW 60S/UPR 50S BY EVE. THIS COMBINES
WITH STRONG NE WINDS WHICH MAY GUST TO 30 MPH...AND TUESDAY WILL
FEEL MORE LIKE NOVEMBER IN SEATTLE THAN OCTOBER IN WILMINGTON! LOWS
TUESDAY NIGHT WILL SHOW VERY LITTLE DIURNAL RANGE...DROPPING ONLY
INTO THE MID 50S INLAND...AROUND 60 AT THE COAST.
LITTLE IMPROVEMENT WEDNESDAY...BUT ANY IMPROVEMENT WILL BE WELCOMED
AFTER TUESDAY! CLOUDS AND RAIN PERSISTING WILL AGAIN LIMIT WARMING
IN THE WEDGE SETUP...AND HIGHS WILL PEAK IN THE UPR 60S INLAND...LOW
70S NEAR THE COAST. LOWS WED NIGHT WILL BE SIMILAR TO TUESDAY
NIGHT...UPR 50S TO LOW 60S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...ONE MORE UNSETTLED DAY THURSDAY AS VERY SLOW
MOVING UPPER LOW AND SURFACE WAVE WILL FINALLY MOVE OFF TO THE
NORTHEAST AND ALLOW FOR DRYING ACROSS THE AREA. GUIDANCE IN
DISAGREEMENT AS TO HOW LONG IT WILL TAKE FOR DRYING TO OCCUR...BUT
WITH UPPER LOW EMBEDDED WITHIN THE 5H RIDGE...THUS MOVING VERY
SLOWLY...WILL LEAN ON THE SLOWER SOLUTION AND KEEP SCHC POP ACROSS
NE ZONES EARLY THURSDAY BEFORE THE ENTIRE AREA DRIES OUT. BEYOND
THURSDAY...HEIGHTS GRADUALLY RISE AND THE WEDGE SLOWLY BREAKS
DOWN...ALLOWING FOR MUCH MORE SUNSHINE AND TEMPS WARMING BACK
TOWARDS CLIMO OR ABOVE BY THE WKND.
GFS/EURO/CMC STILL DEPICT A SECONDARY AREA OF LOW PRESSURE
DEVELOPING WELL OFFSHORE AND THEN RETROGRADING BACK TO THE SW
SAT/SUN TOWARDS THE COAST. WHILE THIS HAS BEEN A PERSISTENT FEATURE
IN THE EXTENDED GUIDANCE...LITTLE AGREEMENT IN SPECIFIC PLACEMENT
AND WHETHER ANY IMPACTS WILL BE FELT LOCALLY. WILL KEEP INHERITED
SILENT POP FOR D6/D7 WITH TEMPS RIGHT AROUND NORMAL FOR MID-OCTOBER.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...SHOWERS CURRENTLY AFFECTING KFLO/KLBT WITH SUB-VFR
FLIGHT CONDITIONS WILL GRADUALLY SPREAD EAST INTO THE COASTAL
TERMINALS TODAY. THIS MORNING INTO THE AFTERNOON MVFR WILL BE LIKELY
AT KFLO/KLBT...WITH TEMPO IFR IN MODERATE RAINFALL. THIS MORNING
COASTAL TERMINALS SHOULD REMAIN GENERALLY VFR WITH TEMPO MVFR
CIGS...WITH MVFR BECOMING MORE LIKELY TOWARDS LATE MORNING AS THE
SHOWERS SHIFT EAST.
AN APPROACHING COLD FRONT WILL PROVIDE ENOUGH LIFT TODAY ALONG WITH
ENOUGH INSTABILITY TO PRODUCE AT LEAST ISOLATED T-STORMS. WILL
CONTINUE VCTS FOR ALL TERMS DURING THE DAYTIME. SOUTHERLY FLOW WILL
PERSIST FOR MUCH OF THE DAY WITH WINDS AROUND 10 KTS. THE FRONT WILL
PASS THROUGH KFLO/KLBT AROUND 00Z TUESDAY...WITH WINDS BECOMING
NORTHEAST AROUND 5 KTS FOLLOWING FROPA. BY 06Z TUESDAY...THE FRONT
SHOULD BE NEAR THE COAST OR JUST OFFSHORE. WILL HOLD ONTO VCSH AT
ALL TERMS THROUGH THE END OF THE TAF PERIOD AS DEEP MOISTURE LINGERS
OVER OUR AREA. THERE IS INCREASING CONFIDENCE OF PREDOMINATE IFR AT
KFLO/KLBT AFTER 06Z.
EXTENDED OUTLOOK...SCATTERED SHOWERS WITH MVFR CIGS ON TUESDAY AS
THE FRONT LINGERS OFFSHORE. MVFR/IFR CIGS AND ISOLATED SHOWERS
POSSIBLE ON WEDNESDAY MORNING...BECOMING VFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 AM MONDAY...SEAS HAVE BUILT TO 5 FT AT ALL THREE BUOYS
STILL REPORTING IN THE CAPE FEAR AREA. WIND SPEEDS ARE ABOUT AS
STRONG AS THEY ARE GOING TO GET...17 TO 20 KNOTS CURRENTLY...AND A
DIMINISHING TREND IS STILL EXPECTED TO DEVELOP THIS AFTERNOON.
PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...
A NORTH-TO-SOUTH ORIENTED COLD FRONT JUST ENTERING THE APPALACHIANS
WILL MOVE EASTWARD TODAY...DECELERATING AS IT APPROACHES THE COAST
TONIGHT. SOUTH-SOUTHEAST WINDS 15-20 KNOTS THIS MORNING SHOULD
DIMINISH THIS AFTERNOON. LOW PRESSURE DEVELOPING ALONG THE FRONT
NEAR THE FLORIDA PANHANDLE WILL BECOME OUR DOMINANT WEATHER FEATURE
TONIGHT. THE INCREASING PRESSURE GRADIENT BETWEEN THIS LOW AND
STRENGTHENING HIGH PRESSURE OVER PENNSYLVANIA WILL LEAD TO
INCREASING WIND SPEEDS LATE TONIGHT. A SURGE IS EXPECTED TO DEVELOP
A FEW HOURS BEFORE DAYBREAK...WITH WINDS TURNING NORTH-NORTHEAST AND
INCREASING TO 15-20 KT.
SEAS CURRENTLY RANGE FROM 5 FT OUT AT THE FRYING PAN SHOALS
BUOY...TO 3-4 FT CLOSER TO SHORE. STEADY ONSHORE WINDS THIS MORNING
SHOULD BRING 5-FOOTERS INTO THE 10-20 MILE WATERS...AND AN EXERCISE
CAUTION HEADLINE WILL BE APPENDED TO THE FORECAST THROUGH EARLY
AFTERNOON. DIMINISHING WINDS THIS AFTERNOON WILL ALLOW SEAS TO
SUBSIDE...BUT LOOK FOR BUILDING SEAS AGAIN VERY LATE TONIGHT IN THE
NORTHERLY SURGE.
SHOWERS AND THUNDERSTORMS CURRENTLY ACROSS EASTERN SOUTH CAROLINA
WILL IMPACT THE SC COASTAL WATERS THIS MORNING. GUSTY WINDS AND
REDUCED VISIBILITY IN HEAVY RAINFALL ARE EXPECTED. THIS ACTIVITY
WILL MOVE EAST AND AFFECT THE NC WATERS THIS AFTERNOON.
PRECIPITATION SHOULD BECOME LESS THUNDERY TONIGHT BUT SHOULD
OTHERWISE CONTINUE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...STRONG NE WINDS WILL PERSIST THROUGH THE
PERIOD AS THREE FEATURES COMBINE TO CREATE POOR MARINE CONDITIONS
INTO MID-WEEK. A WAVE OF LOW PRESSURE WILL DEVELOP ALONG A COLD
FRONT STALLED JUST OFFSHORE...ENHANCING THE ALREADY PINCHED GRADIENT
DUE TO A WEDGE OF HIGH PRESSURE FORMING DOWN THE COAST. THIS CREATES
GUSTY NE WINDS TUESDAY AND WEDNESDAY...WITH SPEEDS OF 15-25 KTS
TUESDAY...DROPPING SLIGHTLY TO 15-20 KTS ON WEDNESDAY. GUSTS TO 30
KTS ARE POSSIBLE...ESPECIALLY ON TUESDAY. THIS CREATES SHORT-PERIOD
AND STEEP WIND WAVES REACHING 4-7 FT TUESDAY...BEFORE FALLING SLOWLY
TO 3-5 FT BY WEDNESDAY EVE. A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR ALL OF TUESDAY AND PARTS OF WEDNESDAY BEFORE CONDITIONS
SLOWLY BEGIN TO IMPROVE LATE IN THE PERIOD.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...GUSTY N/NE WINDS TO START THE PERIOD WILL
GRADUALLY EASE BY THE END OF THE WEEK AS HIGH PRESSURE WEDGE BEGINS
TO BREAK DOWN JUST INLAND FROM THE WATERS. TIGHT GRADIENT THURSDAY
KEEPS N/NE WINDS AT 15-20 KTS...BUT THIS WILL WEAKEN ON
FRIDAY...HELPING WINDS TO FALL TO AROUND 10 KTS AND BACK MORE TO THE
NORTH. WAVE HEIGHTS INITIALLY WILL BE 3-5 FT AND A SCEC MAY BE
REQUIRED...BUT THESE WILL FALL QUICKLY ON FRIDAY TO 2-3 FT THANKS TO
THE DECREASED WINDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR
MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1017 AM EDT MON OCT 7 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA TODAY. ABUNDANT MOISTURE AND
STRONG UPPER LEVEL WINDS WILL PROVIDE FOR HEAVY RAIN AND POSSIBLE
SEVERE WEATHER ACROSS THE REGION. HIGH PRESSURE BUILDS BACK IN
TUESDAY LASTING THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10AM EDT MONDAY...BROKEN LINE OF CONVECTION CONTINUES TO PUSH
EAST OF THE I77 CORRIDOR INTO CENTRAL NC. A FEW LIGHT SHOWERS WILL
BE A POSSIBILITY OVER THE NEXT FEW HOURS BEHIND THE LEADING LINE.
THEREFORE KEPT CHANCE POPS THROUGH MIDDAY OUTSIDE OF THE MOUNTAINS.
OTHERWISE...DECIDED TO GO AHEAD AND LOWER POPS ACROSS THE HIGHER
TERRAIN AS THE FRONT PUSHES THROUGH ADVECTING IN MUCH MORE STABLE
AIR. SKY CONDITIONS WILL SLOWLY IMPROVE ACROSS THE MOUNTAINS
THROUGH THE DAY AS HIGH PRESSURE BUILDS IN BEHIND THE FRONT.
ELSEWHERE...CLOUDS WILL PERSIST THROUGH THE AFTERNOON HOURS AND INTO
MONDAY EVENING AS DEEP LAYER MOISTURE PREVAILS AHEAD OF THE FRONT.
OTHER THAN THE ABOVE MENTIONED POP/WX/SKY ADJUSTMENTS...NO OTHER
CHANGES WERE MADE TO THE FCST AT THIS TIME.
PREVIOUS DISCUSSION...
EARLY THIS MORNING...COLD FROPA IMMINENT WITH SFC TROUGH AND
CONVERGENCE LINE NOW EVIDENTLY JUST EAST OF THE TENN/NC BORDER.
SHORTWAVE IMPULSE LEADING THE CORE OF THE UPPER TROUGH IN THE
MODERATELY UNSTABLE ENVIRONMENT AHEAD OF THE FRONT CONTINUES TO
SUPPORT A FEW TSTMS...THE QLCS WHICH MOVED THRU THE FOOTHILLS
EARLIER THIS AM HAVING BECOME DISORGANIZED. STRONG LLVL SHEAR STILL
PRESENT AND THOUGH RAP ANALYSIS STILL INDICATES SOME INSTABILITY
LAPSE RATES MAY HAVE BECOME NEARLY NEUTRAL/MOIST ADIABATIC WITH THE
COLUMN SATURATING.
THE SHORTWAVE IS STILL MOVING INTO A MORE UNSTABLE ENVIRONMENT...ONE
THAT HAS LARGELY BEEN UNTOUCHED TONIGHT. THUS DEVELOPMENT OF
DISCRETE CONVECTION...MOSTLY SHOWERS WITH A LESSER NUMBER OF
TSTMS...MAY STILL BE EXPECTED THIS MRNG EAST OF A GREENWOOD TO
STATESVILLE LINE. TEMPS WILL LIKELY REMAIN NEARLY STEADY THRU
DAYBREAK...EXCEPT IN THE HIGHER MTNS WHICH MAY SEE SOME COOLER AIR
BEGIN TO FILTER IN.
TODAY...BOTH SYNOPTIC MODELS AND CAM CONSENSUS SHOW THE FRONT EXITING
THE ERN PERIPHERY OF THE CWFA IN 18-21Z TIMEFRAME. PROG SOUNDINGS
FROM CLT/HKY INDICATE MODEST INSTABILITY STILL PRESENT IN THE NC
PIEDMONT AT THAT TIME SO I ALLOWED POPS TO DROP OFF MORE QUICKLY IN
THE WEST WHERE THE FROPA WILL OCCUR EARLIER...HOLDING ONTO LIKELY
POPS EAST THRU PEAK HEATING. HIGHS TODAY HAVE BEEN HELD CLOSE TO A
CONSENSUS OF RAW MODEL TEMPS...WITH CLOUDY CONDITIONS EXPECTED TO
PERSIST MOST OF THE DAY.
TONIGHT...LATEST COUPLE MODEL CYCLES HAVE DECLINED TO DRY THINGS OUT
TOTALLY IN THE WAKE OF THE FRONT...RATHER FEATURING A FRONTAL WAVE
DEVELOPING NEAR THE SC/GA COAST AND SOME RETURNING MOISTURE OVERNIGHT
TONIGHT. THIS WAS HINTED AT FIRST BY THE EC A COUPLE DAYS AGO AND
OTHER MODELS GRADUALLY BOUGHT INTO THIS IDEA. IN LIGHT OF THE TREND I
ALLOWED POPS TO RISE AGAIN SOUTH/EAST OF I-85 TONIGHT. TEMPS WILL BE
NOTICEABLY COOLER...ESPECIALLY IN THE MTNS WHERE THE COOL AND DRY AIR
WILL ALREADY BE IN PLACE THIS EVENING. EVEN IN THE AFOREMENTIONED
AREA OF MORE CLOUDS AND POPS LOWS IN THE MID TO UPPER 50S ARE
EXPECTED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM MONDAY...MAJOR CHANGE IN THE FORECAST DURING THIS
PERIOD AS ALL GUIDANCE POINTS TO AN UPPER LOW...THE REMNANTS OF
KAREN...DETACHING FROM THE FULL LATITUDE TROF OVER THE ERN CONUS
AND SLOWLY MOVING NORTH FROM THE GULF COAST ACROSS THE SERN CONUS.
AT THE SFC...THE LOW PRESSURE AREA THAT IS THE REMNANTS OF KAREN
DETACHES FROM THE COLD FRONT AND SLOWLY MOVES UP THE ATLANTIC
COAST. WITH HIGH PRESSURE CENTERED OVER NEW ENGLAND IN A DAMMING
CONFIGURATION...THE ELY LOW LEVEL FLOW AROUND THESE TWO SYSTEMS
INCREASES AND BRINGS QUITE A BIT OF MOISTURE INTO THE AREA.
ISENTROPIC LIFT WILL BE WEAK...BUT STRONG ENUF TO BRING CLOUDS AND
PRECIP EAST TO WEST ACROSS THE CWFA TUE AND TUE NITE. THE FLOW
BECOMES A LITTLE MORE NLY WED AND WED NITE AND MOISTURE SLOWLY PULLS
OUT OF THE AREA AS THE LOW MOVES UP THE COAST. THIS MEANS
DIMINISHING POP FROM WEST TO EAST WED AND WED NITE. FOR NOW...IT
APPEARS PRECIP WILL BE LIGHT WITH THE BEST CHC ALONG AND SOUTH OF
I-85 IN NE GA AND THE UPSTATE...AND OVER THE FOOTHILLS AND PIEDMONT
IN NC. BREEZY TO POSSIBLY WINDY CONDITIONS ARE EXPECTED THRU THE
PERIOD AS THE PRESSURE GRADIENT TIGHTENS BETWEEN THE LOW AND HIGH.
MUCH MORE CLOUDINESS IS EXPECTED AS WELL. THE COMBINATION OF CLOUDS
AND PRECIP WILL BRING HIGHS GENERALLY IN THE LOW TO MID 60S...WITH
SOME UPPER 60S POSSIBLE IN THE FAR WRN CWFA. LOWS IN THE LOW TO MID
50S TUE NITE FALL TO THE UPPER 40S TO LOWER 50S WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 AM MON...THE UPPER LOW FEATURED IN THE SHORT RANGE FCST
SLOWLY MOVES EAST ACROSS NC/VA THEN OFF SHORE BY SUN. SOME WEAK
RIDGING BUILDS IN BEHIND THE LOW AS SHORT WAVES MOVE UP THE RIDGE
AND ACROSS THE OH VALLEY. AT THE SFC...THE COASTAL LOW CONTINUES ITS
TREK UP THE EAST COAST AS THE DAMMING SFC HIGH WEAKENS. A DRIER N TO
NWLY FLOW SETS UP AS THIS SYSTEM MOVES OUT OF THE AREA. THE GFS THEN
TRIES TO BRINGS MOISTURE AND PRECIP BACK INTO THE AREA FROM THE NE
BY THE WEEKEND AS ELY FLOW STRENGTHENS. THE CANADIAN AND THE ECMWF
ARE MUCH WEAKER WITH THE FLOW AND ANY MOISTURE. THEREFORE...HAVE
KEPT THE FCST DRY FOR NOW. HIGHS START OUT A LITTLE BELOW NORMAL
THEN QUICKLY RISE TO NEAR NORMAL AND REMAIN NEARLY STEADY THRU THE
NED OF THE PERIOD. LOWS START OUT NEAR NORMAL THEN RISE A FEW
DEGREES BY THE EN OF THE PERIOD.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AT KCLT...COLD FRONT WILL MOVE THROUGH THE AREA TODAY...PRECEDED BY
SHRA/TSRA. A LINE OF HEAVY SHRA WITH A COUPLE EMBEDDED TSRA MAY
BRING A PERIOD OF IFR CIGS/VSBY TO THE FIELD AROUND OR JUST AFTER
DAYBREAK...BUT WITH MOST OF THE CONVECTION MOVING PARALLEL TO THE
WHOLE LINE IT IS MOVING SLOWLY. CHANCES WARRANT A TEMPO FOR THE
FIRST COUPLE HOURS. LOW END GUSTS POSSIBLE WITH THE LINE ALSO. MVFR
CIG EXPECTED TO PERSIST UNTIL THE FROPA LIFTS THEM TO VFR AND STARTS
A CLEARING TREND THIS AFTN. UNSTABLE ENVIRONMENT ALONG WITH UPPER
ENERGY PASSING OVERHEAD MAY ALLOW DISCRETE SHRA OR TSRA CAUSING
BRIEF RESTRICTIONS UNTIL THEN. GENERALLY SOUTHERLY WINDS WILL FLIP
TO NW FOLLOWING THE FROPA...BEFORE VEERING NE LATE IN THE PERIOD.
TONIGHT...SOME MAINLY MIDLEVEL MOISTURE WILL RIDE BACK UP OVER THE
FRONT AND BRING BACK A CIG TOWARD DAYBREAK. GUIDANCE GIVING A STRONG
SIGNAL THIS WILL BE VFR.
ELSEWHERE...MUCH LIKE KCLT BUT WITH FROPA AND NWLY WIND SHIFT
ARRIVING EARLIER. IT MAY HAVE ALREADY OCCURRED BY 12Z IN THE
MTNS...THEN LATER THIS MRNG FOOTHILLS AND UPPER PIEDMONT...MIDDAY
ELSEWHERE. STRATIFORM RAIN AND WIDELY SCATTERED HEAVY SHRA/TSRA WILL
REMAIN IN SOME FORM BEFORE THE FROPA. VFR CONDITIONS SHOULD RETURN
TO ALL SITES THIS AFTERNOON WITH THE WRN SITES POSSIBLY LOSING CIG
ALTOGETHER BEFORE 00Z. THE PIEDMONT WILL SEE CIGS FORM AGAIN LATE
TONIGHT AS A FRONTAL WAVE SPREADS MOISTURE FROM THE STALLED FRONT
BACK OVER THE REGION. WITH THE COOLER AIRMASS WORKING IN THIS
EVENING...SFC SHOULD REMAIN DRY ENOUGH TO PRECLUDE FOG EXCEPT
PERHAPS IN THE MOST SHELTERED MTN VALLEYS...KAVL BEING EXCLUDED.
OUTLOOK...MODERATELY SETTLED CONDITIONS WILL REMAIN THROUGH MIDWEEK
THOUGH A WEAK UPPER LEVEL LOW MAY PRODUCE CIGS AND LIGHT
PRECIP...WITH POSSIBLE RESTRICTIONS IN SHOWERS. MORNING MTN VALLEY
FOG ALSO MAY IMPACT FLIGHT RULES.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT HIGH 94% HIGH 90% HIGH 100% HIGH 100%
KGSP HIGH 82% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 82% HIGH 100% HIGH 100% HIGH 94%
KHKY HIGH 80% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 91% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 91% HIGH 98% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
806 AM EDT MON OCT 7 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA TODAY. ABUNDANT MOISTURE AND
STRONG UPPER LEVEL WINDS WILL PROVIDE FOR HEAVY RAIN AND POSSIBLE
SEVERE WEATHER ACROSS THE REGION. HIGH PRESSURE BUILDS BACK IN
TUESDAY LASTING THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 8AM EDT MONDAY...LINE OF SHOWERS AND THUNDERSTORMS CONTINUES
TO MOVE EASTWARD ACROSS THE COVERAGE AREA WITH THE HEAVIEST
CONVECTION BEING ALONG A LINE NEAR THE I77 CORRIDOR. THIS LINE WILL
MOVE INTO CHARLOTTE METRO WITHIN THE HOUR. THE MAIN THREATS AT THIS
TIME ARE GUSTY WINDS AND HEAVY RAINFALL. MEANWHILE TO THE
WEST...LEADING EDGE OF THE COLD FRONT IS PUSHING THROUGH THE
MOUNTAINS AND WILL CONTINUE MOVING EASTWARD THROUGH THE DAY.
ADJUSTED EXTREME NEAR TERM POPS TO REFLECT LATEST RADAR TRENDS AND
LEFT THE REMAINDER OF THE FORECAST AS IS.
PREVIOUS DISCUSSION...
EARLY THIS MORNING...COLD FROPA IMMINENT WITH SFC TROUGH AND
CONVERGENCE LINE NOW EVIDENTLY JUST EAST OF THE TENN/NC BORDER.
SHORTWAVE IMPULSE LEADING THE CORE OF THE UPPER TROUGH IN THE
MODERATELY UNSTABLE ENVIRONMENT AHEAD OF THE FRONT CONTINUES TO
SUPPORT A FEW TSTMS...THE QLCS WHICH MOVED THRU THE FOOTHILLS
EARLIER THIS AM HAVING BECOME DISORGANIZED. STRONG LLVL SHEAR STILL
PRESENT AND THOUGH RAP ANALYSIS STILL INDICATES SOME INSTABILITY
LAPSE RATES MAY HAVE BECOME NEARLY NEUTRAL/MOIST ADIABATIC WITH THE
COLUMN SATURATING.
THE SHORTWAVE IS STILL MOVING INTO A MORE UNSTABLE ENVIRONMENT...ONE
THAT HAS LARGELY BEEN UNTOUCHED TONIGHT. THUS DEVELOPMENT OF
DISCRETE CONVECTION...MOSTLY SHOWERS WITH A LESSER NUMBER OF
TSTMS...MAY STILL BE EXPECTED THIS MRNG EAST OF A GREENWOOD TO
STATESVILLE LINE. TEMPS WILL LIKELY REMAIN NEARLY STEADY THRU
DAYBREAK...EXCEPT IN THE HIGHER MTNS WHICH MAY SEE SOME COOLER AIR
BEGIN TO FILTER IN.
TODAY...BOTH SYNOPTIC MODELS AND CAM CONSENSUS SHOW THE FRONT EXITING
THE ERN PERIPHERY OF THE CWFA IN 18-21Z TIMEFRAME. PROG SOUNDINGS
FROM CLT/HKY INDICATE MODEST INSTABILITY STILL PRESENT IN THE NC
PIEDMONT AT THAT TIME SO I ALLOWED POPS TO DROP OFF MORE QUICKLY IN
THE WEST WHERE THE FROPA WILL OCCUR EARLIER...HOLDING ONTO LIKELY
POPS EAST THRU PEAK HEATING. HIGHS TODAY HAVE BEEN HELD CLOSE TO A
CONSENSUS OF RAW MODEL TEMPS...WITH CLOUDY CONDITIONS EXPECTED TO
PERSIST MOST OF THE DAY.
TONIGHT...LATEST COUPLE MODEL CYCLES HAVE DECLINED TO DRY THINGS OUT
TOTALLY IN THE WAKE OF THE FRONT...RATHER FEATURING A FRONTAL WAVE
DEVELOPING NEAR THE SC/GA COAST AND SOME RETURNING MOISTURE OVERNIGHT
TONIGHT. THIS WAS HINTED AT FIRST BY THE EC A COUPLE DAYS AGO AND
OTHER MODELS GRADUALLY BOUGHT INTO THIS IDEA. IN LIGHT OF THE TREND I
ALLOWED POPS TO RISE AGAIN SOUTH/EAST OF I-85 TONIGHT. TEMPS WILL BE
NOTICEABLY COOLER...ESPECIALLY IN THE MTNS WHERE THE COOL AND DRY AIR
WILL ALREADY BE IN PLACE THIS EVENING. EVEN IN THE AFOREMENTIONED
AREA OF MORE CLOUDS AND POPS LOWS IN THE MID TO UPPER 50S ARE
EXPECTED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM MONDAY...MAJOR CHANGE IN THE FORECAST DURING THIS
PERIOD AS ALL GUIDANCE POINTS TO AN UPPER LOW...THE REMNANTS OF
KAREN...DETACHING FROM THE FULL LATITUDE TROF OVER THE ERN CONUS
AND SLOWLY MOVING NORTH FROM THE GULF COAST ACROSS THE SERN CONUS.
AT THE SFC...THE LOW PRESSURE AREA THAT IS THE REMNANTS OF KAREN
DETACHES FROM THE COLD FRONT AND SLOWLY MOVES UP THE ATLANTIC
COAST. WITH HIGH PRESSURE CENTERED OVER NEW ENGLAND IN A DAMMING
CONFIGURATION...THE ELY LOW LEVEL FLOW AROUND THESE TWO SYSTEMS
INCREASES AND BRINGS QUITE A BIT OF MOISTURE INTO THE AREA.
ISENTROPIC LIFT WILL BE WEAK...BUT STRONG ENUF TO BRING CLOUDS AND
PRECIP EAST TO WEST ACROSS THE CWFA TUE AND TUE NITE. THE FLOW
BECOMES A LITTLE MORE NLY WED AND WED NITE AND MOISTURE SLOWLY PULLS
OUT OF THE AREA AS THE LOW MOVES UP THE COAST. THIS MEANS
DIMINISHING POP FROM WEST TO EAST WED AND WED NITE. FOR NOW...IT
APPEARS PRECIP WILL BE LIGHT WITH THE BEST CHC ALONG AND SOUTH OF
I-85 IN NE GA AND THE UPSTATE...AND OVER THE FOOTHILLS AND PIEDMONT
IN NC. BREEZY TO POSSIBLY WINDY CONDITIONS ARE EXPECTED THRU THE
PERIOD AS THE PRESSURE GRADIENT TIGHTENS BETWEEN THE LOW AND HIGH.
MUCH MORE CLOUDINESS IS EXPECTED AS WELL. THE COMBINATION OF CLOUDS
AND PRECIP WILL BRING HIGHS GENERALLY IN THE LOW TO MID 60S...WITH
SOME UPPER 60S POSSIBLE IN THE FAR WRN CWFA. LOWS IN THE LOW TO MID
50S TUE NITE FALL TO THE UPPER 40S TO LOWER 50S WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 AM MON...THE UPPER LOW FEATURED IN THE SHORT RANGE FCST
SLOWLY MOVES EAST ACROSS NC/VA THEN OFF SHORE BY SUN. SOME WEAK
RIDGING BUILDS IN BEHIND THE LOW AS SHORT WAVES MOVE UP THE RIDGE
AND ACROSS THE OH VALLEY. AT THE SFC...THE COASTAL LOW CONTINUES ITS
TREK UP THE EAST COAST AS THE DAMMING SFC HIGH WEAKENS. A DRIER N TO
NWLY FLOW SETS UP AS THIS SYSTEM MOVES OUT OF THE AREA. THE GFS THEN
TRIES TO BRINGS MOISTURE AND PRECIP BACK INTO THE AREA FROM THE NE
BY THE WEEKEND AS ELY FLOW STRENGTHENS. THE CANADIAN AND THE ECMWF
ARE MUCH WEAKER WITH THE FLOW AND ANY MOISTURE. THEREFORE...HAVE
KEPT THE FCST DRY FOR NOW. HIGHS START OUT A LITTLE BELOW NORMAL
THEN QUICKLY RISE TO NEAR NORMAL AND REMAIN NEARLY STEADY THRU THE
NED OF THE PERIOD. LOWS START OUT NEAR NORMAL THEN RISE A FEW
DEGREES BY THE EN OF THE PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT...COLD FRONT WILL MOVE THROUGH THE AREA TODAY...PRECEDED BY
SHRA/TSRA. A LINE OF HEAVY SHRA WITH A COUPLE EMBEDDED TSRA MAY
BRING A PERIOD OF IFR CIGS/VSBY TO THE FIELD AROUND OR JUST AFTER
DAYBREAK...BUT WITH MOST OF THE CONVECTION MOVING PARALLEL TO THE
WHOLE LINE IT IS MOVING SLOWLY. CHANCES WARRANT A TEMPO FOR THE
FIRST COUPLE HOURS. LOW END GUSTS POSSIBLE WITH THE LINE ALSO. MVFR
CIG EXPECTED TO PERSIST UNTIL THE FROPA LIFTS THEM TO VFR AND STARTS
A CLEARING TREND THIS AFTN. UNSTABLE ENVIRONMENT ALONG WITH UPPER
ENERGY PASSING OVERHEAD MAY ALLOW DISCRETE SHRA OR TSRA CAUSING
BRIEF RESTRICTIONS UNTIL THEN. GENERALLY SOUTHERLY WINDS WILL FLIP
TO NW FOLLOWING THE FROPA...BEFORE VEERING NE LATE IN THE PERIOD.
TONIGHT...SOME MAINLY MIDLEVEL MOISTURE WILL RIDE BACK UP OVER THE
FRONT AND BRING BACK A CIG TOWARD DAYBREAK. GUIDANCE GIVING A STRONG
SIGNAL THIS WILL BE VFR.
ELSEWHERE...MUCH LIKE KCLT BUT WITH FROPA AND NWLY WIND SHIFT
ARRIVING EARLIER. IT MAY HAVE ALREADY OCCURRED BY 12Z IN THE
MTNS...THEN LATER THIS MRNG FOOTHILLS AND UPPER PIEDMONT...MIDDAY
ELSEWHERE. STRATIFORM RAIN AND WIDELY SCATTERED HEAVY SHRA/TSRA WILL
REMAIN IN SOME FORM BEFORE THE FROPA. VFR CONDITIONS SHOULD RETURN
TO ALL SITES THIS AFTERNOON WITH THE WRN SITES POSSIBLY LOSING CIG
ALTOGETHER BEFORE 00Z. THE PIEDMONT WILL SEE CIGS FORM AGAIN LATE
TONIGHT AS A FRONTAL WAVE SPREADS MOISTURE FROM THE STALLED FRONT
BACK OVER THE REGION. WITH THE COOLER AIRMASS WORKING IN THIS
EVENING...SFC SHOULD REMAIN DRY ENOUGH TO PRECLUDE FOG EXCEPT
PERHAPS IN THE MOST SHELTERED MTN VALLEYS...KAVL BEING EXCLUDED.
OUTLOOK...MODERATELY SETTLED CONDITIONS WILL REMAIN THROUGH MIDWEEK
THOUGH A WEAK UPPER LEVEL LOW MAY PRODUCE CIGS AND LIGHT
PRECIP...WITH POSSIBLE RESTRICTIONS IN SHOWERS. MORNING MTN VALLEY
FOG ALSO MAY IMPACT FLIGHT RULES.
CONFIDENCE TABLE...
12-18Z 18-24Z 00-06Z 06-12Z
KCLT HIGH 100% HIGH 80% HIGH 100% HIGH 100%
KGSP MED 79% HIGH 94% HIGH 100% HIGH 100%
KAVL MED 75% HIGH 100% HIGH 100% HIGH 100%
KHKY MED 67% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 83% HIGH 96% HIGH 100% HIGH 100%
KAND MED 79% HIGH 95% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
734 AM EDT MON OCT 7 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE AREA TODAY. ABUNDANT MOISTURE AND
STRONG UPPER LEVEL WINDS WILL PROVIDE FOR HEAVY RAIN AND POSSIBLE
SEVERE WEATHER ACROSS THE REGION. HIGH PRESSURE BUILDS BACK IN
TUESDAY LASTING THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...COLD FROPA IMMINENT WITH SFC TROUGH AND
CONVERGENCE LINE NOW EVIDENTLY JUST EAST OF THE TENN/NC BORDER.
SHORTWAVE IMPULSE LEADING THE CORE OF THE UPPER TROUGH IN THE
MODERATELY UNSTABLE ENVIRONMENT AHEAD OF THE FRONT CONTINUES TO
SUPPORT A FEW TSTMS...THE QLCS WHICH MOVED THRU THE FOOTHILLS
EARLIER THIS AM HAVING BECOME DISORGANIZED. STRONG LLVL SHEAR STILL
PRESENT AND THOUGH RAP ANALYSIS STILL INDICATES SOME INSTABILITY
LAPSE RATES MAY HAVE BECOME NEARLY NEUTRAL/MOIST ADIABATIC WITH THE
COLUMN SATURATING.
THE SHORTWAVE IS STILL MOVING INTO A MORE UNSTABLE ENVIRONMENT...ONE
THAT HAS LARGELY BEEN UNTOUCHED TONIGHT. THUS DEVELOPMENT OF
DISCRETE CONVECTION...MOSTLY SHOWERS WITH A LESSER NUMBER OF
TSTMS...MAY STILL BE EXPECTED THIS MRNG EAST OF A GREENWOOD TO
STATESVILLE LINE. TEMPS WILL LIKELY REMAIN NEARLY STEADY THRU
DAYBREAK...EXCEPT IN THE HIGHER MTNS WHICH MAY SEE SOME COOLER AIR
BEGIN TO FILTER IN.
TODAY...BOTH SYNOPTIC MODELS AND CAM CONSENSUS SHOW THE FRONT EXITING
THE ERN PERIPHERY OF THE CWFA IN 18-21Z TIMEFRAME. PROG SOUNDINGS
FROM CLT/HKY INDICATE MODEST INSTABILITY STILL PRESENT IN THE NC
PIEDMONT AT THAT TIME SO I ALLOWED POPS TO DROP OFF MORE QUICKLY IN
THE WEST WHERE THE FROPA WILL OCCUR EARLIER...HOLDING ONTO LIKELY
POPS EAST THRU PEAK HEATING. HIGHS TODAY HAVE BEEN HELD CLOSE TO A
CONSENSUS OF RAW MODEL TEMPS...WITH CLOUDY CONDITIONS EXPECTED TO
PERSIST MOST OF THE DAY.
TONIGHT...LATEST COUPLE MODEL CYCLES HAVE DECLINED TO DRY THINGS OUT
TOTALLY IN THE WAKE OF THE FRONT...RATHER FEATURING A FRONTAL WAVE
DEVELOPING NEAR THE SC/GA COAST AND SOME RETURNING MOISTURE OVERNIGHT
TONIGHT. THIS WAS HINTED AT FIRST BY THE EC A COUPLE DAYS AGO AND
OTHER MODELS GRADUALLY BOUGHT INTO THIS IDEA. IN LIGHT OF THE TREND I
ALLOWED POPS TO RISE AGAIN SOUTH/EAST OF I-85 TONIGHT. TEMPS WILL BE
NOTICEABLY COOLER...ESPECIALLY IN THE MTNS WHERE THE COOL AND DRY AIR
WILL ALREADY BE IN PLACE THIS EVENING. EVEN IN THE AFOREMENTIONED
AREA OF MORE CLOUDS AND POPS LOWS IN THE MID TO UPPER 50S ARE
EXPECTED.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 230 AM MONDAY...MAJOR CHANGE IN THE FORECAST DURING THIS
PERIOD AS ALL GUIDANCE POINTS TO AN UPPER LOW...THE REMNANTS OF
KAREN...DETACHING FROM THE FULL LATITUDE TROF OVER THE ERN CONUS
AND SLOWLY MOVING NORTH FROM THE GULF COAST ACROSS THE SERN CONUS.
AT THE SFC...THE LOW PRESSURE AREA THAT IS THE REMNANTS OF KAREN
DETACHES FROM THE COLD FRONT AND SLOWLY MOVES UP THE ATLANTIC
COAST. WITH HIGH PRESSURE CENTERED OVER NEW ENGLAND IN A DAMMING
CONFIGURATION...THE ELY LOW LEVEL FLOW AROUND THESE TWO SYSTEMS
INCREASES AND BRINGS QUITE A BIT OF MOISTURE INTO THE AREA.
ISENTROPIC LIFT WILL BE WEAK...BUT STRONG ENUF TO BRING CLOUDS AND
PRECIP EAST TO WEST ACROSS THE CWFA TUE AND TUE NITE. THE FLOW
BECOMES A LITTLE MORE NLY WED AND WED NITE AND MOISTURE SLOWLY PULLS
OUT OF THE AREA AS THE LOW MOVES UP THE COAST. THIS MEANS
DIMINISHING POP FROM WEST TO EAST WED AND WED NITE. FOR NOW...IT
APPEARS PRECIP WILL BE LIGHT WITH THE BEST CHC ALONG AND SOUTH OF
I-85 IN NE GA AND THE UPSTATE...AND OVER THE FOOTHILLS AND PIEDMONT
IN NC. BREEZY TO POSSIBLY WINDY CONDITIONS ARE EXPECTED THRU THE
PERIOD AS THE PRESSURE GRADIENT TIGHTENS BETWEEN THE LOW AND HIGH.
MUCH MORE CLOUDINESS IS EXPECTED AS WELL. THE COMBINATION OF CLOUDS
AND PRECIP WILL BRING HIGHS GENERALLY IN THE LOW TO MID 60S...WITH
SOME UPPER 60S POSSIBLE IN THE FAR WRN CWFA. LOWS IN THE LOW TO MID
50S TUE NITE FALL TO THE UPPER 40S TO LOWER 50S WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 310 AM MON...THE UPPER LOW FEATURED IN THE SHORT RANGE FCST
SLOWLY MOVES EAST ACROSS NC/VA THEN OFF SHORE BY SUN. SOME WEAK
RIDGING BUILDS IN BEHIND THE LOW AS SHORT WAVES MOVE UP THE RIDGE
AND ACROSS THE OH VALLEY. AT THE SFC...THE COASTAL LOW CONTINUES ITS
TREK UP THE EAST COAST AS THE DAMMING SFC HIGH WEAKENS. A DRIER N TO
NWLY FLOW SETS UP AS THIS SYSTEM MOVES OUT OF THE AREA. THE GFS THEN
TRIES TO BRINGS MOISTURE AND PRECIP BACK INTO THE AREA FROM THE NE
BY THE WEEKEND AS ELY FLOW STRENGTHENS. THE CANADIAN AND THE ECMWF
ARE MUCH WEAKER WITH THE FLOW AND ANY MOISTURE. THEREFORE...HAVE
KEPT THE FCST DRY FOR NOW. HIGHS START OUT A LITTLE BELOW NORMAL
THEN QUICKLY RISE TO NEAR NORMAL AND REMAIN NEARLY STEADY THRU THE
NED OF THE PERIOD. LOWS START OUT NEAR NORMAL THEN RISE A FEW
DEGREES BY THE EN OF THE PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT...COLD FRONT WILL MOVE THROUGH THE AREA TODAY...PRECEDED BY
SHRA/TSRA. A LINE OF HEAVY SHRA WITH A COUPLE EMBEDDED TSRA MAY
BRING A PERIOD OF IFR CIGS/VSBY TO THE FIELD AROUND OR JUST AFTER
DAYBREAK...BUT WITH MOST OF THE CONVECTION MOVING PARALLEL TO THE
WHOLE LINE IT IS MOVING SLOWLY. CHANCES WARRANT A TEMPO FOR THE
FIRST COUPLE HOURS. LOW END GUSTS POSSIBLE WITH THE LINE ALSO. MVFR
CIG EXPECTED TO PERSIST UNTIL THE FROPA LIFTS THEM TO VFR AND STARTS
A CLEARING TREND THIS AFTN. UNSTABLE ENVIRONMENT ALONG WITH UPPER
ENERGY PASSING OVERHEAD MAY ALLOW DISCRETE SHRA OR TSRA CAUSING
BRIEF RESTRICTIONS UNTIL THEN. GENERALLY SOUTHERLY WINDS WILL FLIP
TO NW FOLLOWING THE FROPA...BEFORE VEERING NE LATE IN THE PERIOD.
TONIGHT...SOME MAINLY MIDLEVEL MOISTURE WILL RIDE BACK UP OVER THE
FRONT AND BRING BACK A CIG TOWARD DAYBREAK. GUIDANCE GIVING A STRONG
SIGNAL THIS WILL BE VFR.
ELSEWHERE...MUCH LIKE KCLT BUT WITH FROPA AND NWLY WIND SHIFT
ARRIVING EARLIER. IT MAY HAVE ALREADY OCCURRED BY 12Z IN THE
MTNS...THEN LATER THIS MRNG FOOTHILLS AND UPPER PIEDMONT...MIDDAY
ELSEWHERE. STRATIFORM RAIN AND WIDELY SCATTERED HEAVY SHRA/TSRA WILL
REMAIN IN SOME FORM BEFORE THE FROPA. VFR CONDITIONS SHOULD RETURN
TO ALL SITES THIS AFTERNOON WITH THE WRN SITES POSSIBLY LOSING CIG
ALTOGETHER BEFORE 00Z. THE PIEDMONT WILL SEE CIGS FORM AGAIN LATE
TONIGHT AS A FRONTAL WAVE SPREADS MOISTURE FROM THE STALLED FRONT
BACK OVER THE REGION. WITH THE COOLER AIRMASS WORKING IN THIS
EVENING...SFC SHOULD REMAIN DRY ENOUGH TO PRECLUDE FOG EXCEPT
PERHAPS IN THE MOST SHELTERED MTN VALLEYS...KAVL BEING EXCLUDED.
OUTLOOK...MODERATELY SETTLED CONDITIONS WILL REMAIN THROUGH MIDWEEK
THOUGH A WEAK UPPER LEVEL LOW MAY PRODUCE CIGS AND LIGHT
PRECIP...WITH POSSIBLE RESTRICTIONS IN SHOWERS. MORNING MTN VALLEY
FOG ALSO MAY IMPACT FLIGHT RULES.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT HIGH 100% HIGH 85% HIGH 97% HIGH 100%
KGSP MED 77% HIGH 92% HIGH 100% HIGH 100%
KAVL MED 75% HIGH 98% HIGH 100% HIGH 100%
KHKY MED 61% HIGH 98% HIGH 100% HIGH 100%
KGMU HIGH 85% HIGH 92% HIGH 100% HIGH 100%
KAND MED 79% HIGH 94% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...RWH
NEAR TERM...WIMBERLEY
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
613 PM EDT MON OCT 7 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING
ACCOMPANIED BY BRIEF HEAVY RAIN...GUSTY WINDS AND ISOLATED
THUNDERSTORMS. HIGH PRESSURE WILL RESULT IN DRY AND SEASONABLE
WEATHER TUE INTO THU AFTERNOON. LOW PRESSURE MAY BRING A BIT OF
RAIN AT TIMES THU NIGHT INTO EARLY NEXT WEEK...BUT ONLY IF THE
SYSTEM TRACKS FAR ENOUGH NORTH. THERE IS VERY LOW FORECAST
CONFIDENCE LATE IN THE WEEK INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
615 PM UPDATE...
***SEVERE THUNDERSTORM WATCH THROUGH 10 PM FOR SOUTHERN
NH...WESTERN/CENTRAL MA AS WELL AS NORTHEAST MA AND NORTHERN CT***
NARROW LINE OF HEAVY SHOWERS ALONG WITH POCKETS OF STRONG WIND GUSTS
WERE MOVING ACROSS SOUTHWEST NH/WESTERN MA AND NORTHERN CT EARLY
THIS EVENING. HRRR MODEL HAS HAD A PRETTY GOOD HANDLE ON THIS
ACTIVITY AND EXPECT IT TO CONTINUE TO MOVE EAST OVER THE NEXT FEW
HOURS. THE BULK OF THE ACTIVITY SHOULD EXIT THE COASTLINE BY 10 OR
11 PM...ALTHOUGH SHOULD LINGER A BIT LONGER ACROSS THE SOUTHEAST NEW
ENGLAND COAST. THERE ALSO COULD BE A FEW LIGHTER SHOWERS LINGERING
BEHIND THE MAIN LINE.
THIS IS A CLASSIC HIGH SHEAR BUT VERY LOW CAPE ENVIRONMENT. IN
FACT...HAVEN/T EVEN SEEN ANY CLOUD TO GROUND LIGHTNING RECENTLY. MAY
SEE AN ISOLATED LIGHTNING STRIKE IN THE NEXT HOUR OR TWO...BUT
CERTAINLY NOT MUCH. REGARDLESS...WITH THE VERY STRONG JET DYNAMICS
AND FULLY LEAFED TREES WE HAVE BEEN GETTING A LOT OF TREE DAMAGE
REPORTS. WE DID EXTEND SEVERE THUNDERSTORM WATCH INTO NORTHEAST MA
THROUGH 10 PM WHERE BEST LOW LEVEL JET MOVES INTO OVER THE NEXT FEW
HOURS. ALSO...THE REST OF THE REGION IS COVERED IN A WIND ADVISORY
EXCEPT FOR THE SOUTH COAST. MANY LOCATIONS MAY REMAIN BELOW WIND
ADVISORY CRITERIA...BUT GIVEN FULLY LEAFED TREES INCREASED RISK FOR
DAMAGE WILL CONTINUE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
LARGE HIGH PRES BUILDS E ACROSS SNE BRINGING SUNNY SKIES AND
SEASONABLY MILD TEMPS. COLUMN IS QUITE DRY SO EVEN CU WILL BE
LIMITED. HIGH TEMPS WILL REACH MID/UPPER 60S...COOLER HIGHER
TERRAIN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
HIGHLIGHTS...
* DRY AND SEASONABLE WEATHER LIKELY WED AND MOST OF THU
* A BIT OF RAIN POSSIBLE AT TIMES THU NIGHT INTO EARLY NEXT WEEK
* MAY END UP COMPLETELY DRY IF STORM STAYS SOUTH
DETAILS...
TUESDAY NIGHT...
HIGH PRESSURE WILL BUILD ACROSS NORTHERN NEW ENGLAND AND RESULT IN A
CHILLY NIGHT. LOW TEMPS WILL FALL MAINLY INTO THE 30S...TO THE
MIDDLE 40S ACROSS MOST AREAS. WE MAY NEED TO CONSIDER FROST
ADVISORIES FOR PORTIONS OF SOUTHWEST NH/NORTHWEST MA...IF WINDS ARE
ABLE TO DECOUPLE WHICH REMAINS UNCERTAIN AT THIS POINT.
WEDNESDAY AND THURSDAY...
LARGE HIGH PRESSURE SHOULD KEEP OUR WEATHER DRY WEDNESDAY INTO MOST
OF THURSDAY AFTERNOON. MODEL CROSS SECTIONS DO INDICATE THAT WE MAY
SEE SOME HIGH CLOUDINESS MOVE IN FROM A LOW PRESSURE SYSTEM OVER THE
MID ATLANTIC. THIS SHOULD ALSO RESULT IN ONSHORE FLOW KEEPING HIGH
MAINLY IN THE 60S...ALTHOUGH A FEW LOWER 70S MAY BE POSSIBLE ACROSS
THE INTERIOR.
THURSDAY NIGHT THROUGH MONDAY...
FORECAST CONFIDENCE REMAINS VERY LOW OVER THIS TIME PERIOD. HIGH
PRESSURE WILL REMAIN LOCATED ACROSS THE CANADIAN MARITIMES WITH A
LOW MEANDERING SOMEWHERE TO OUR SOUTH. DEPENDING ON HOW FAR NORTH
THIS LOW PRESSURE SYSTEM GETS WILL DETERMINE IF WE END UP GETTING A
PERIOD OR TWO OF RAIN. BIGGER THREAT FOR A SUSTAINED PERIOD OF WET
WEATHER WILL BE TO OUR SOUTH...BUT CAN/T RULE OUT SOME RAIN IN OUR
REGION WITH BEST CHANCE IN THE SOUTHERN ZONES. THE MODELS AND
ENSEMBLES HAVE SHOWN DIFFERING SOLUTIONS AND VERY POOR RUN TO RUN
CONSISTENCY. WILL GENERALLY RUN WITH 20 TO 30 POPS TO COVER THIS
POTENTIAL...WITH THE HIGHER POPS IN OUR SOUTHERN ZONES. BEST CHANCE
FOR A BIT OF RAIN MAY COME THU NIGHT INTO FRI THEN AGAIN LATER SUN
INTO MON. ITS ALSO POSSIBLE ALL THE RAIN REMAINS TO OUR SOUTH OVER
THIS TIME...JUST TOO UNCERTAIN TO SAY MUCH MORE AT THIS POINT.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...HIGH CONFIDENCE IN TRENDS LOWER
CONFIDENCE IN TIMING.
CONDITIONS HAVE TEMPORARILY IMPROVED TO MVFR/VFR AS WARM FRONT HAS
LIFTED TO THE NORTH. INCREASING S WINDS WILL DEVELOP WITH GUSTS TO
35 KT POSSIBLE THROUGH THE REST OF THE AFTERNOON...ESPECIALLY AWAY
FROM S COAST. EXPECT IFR TO REDEVELOP LATER THIS AFTERNOON AND
EVENING AS LINE OF SHOWERS/TSTMS MOVE THROUGH. BRIEF HEAVY RAIN
AND STRONG WINDS WILL LIKELY ACCOMPANY THIS LINE OF
CONVECTION...ESPECIALLY CT VALLEY THEN GRADUALLY WEAKEN AS IT
MOVES TO THE COASTAL PLAIN. IMPROVING CONDITIONS TO VFR FROM WEST
TO EAST 03-08Z. VFR TUESDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
EXACT TIMING. WIDESPREAD MVFR EXPECTED WITH A BRIEF PERIOD OF IFR
POSSIBLE THIS EVENING. BRIEF HEAVY RAIN POSSIBLE 23-03Z. WIND
GUSTS TO 35 KT THROUGH 00Z.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
EXACT TIMING. WIDESPREAD MVFR WITH A BRIEF PERIOD OF IFR POSSIBLE
LATE AFTERNOON AND EARLY EVENING. BRIEF HEAVY RAIN 21-00Z. WIND
GUSTS TO 35 KT POSSIBLE THIS AFTERNOON.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
TUE NIGHT THROUGH THURSDAY...HIGH CONFIDENCE IN MAINLY VFR
CONDITIONS.
THURSDAY NIGHT THROUGH SATURDAY...LOW CONFIDENCE. SOME MVFR TO EVEN
IFR CONDITIONS ARE POSSIBLE AT TIMES IF A MID ATLANTIC LOW MAKES IT
FAR ENOUGH NORTH ALLOWING FOR SOME RAIN. BEST CHANCE WOULD BE THU
NIGHT/FRI.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TUESDAY/...MODERATE CONFIDENCE.
520 PM UPDATE...
ONLY CHANGE WAS TO UPGRADE BOSTON HARBOR TO A GALE WARNING THROUGH 9
PM WHERE AS BEST LOW LEVEL JET MOVES OVER THE REGION. TEMPS ARE
ALSO THE WARMEST IN NORTHEAST MA...SO BETTER CHANCE OF MIXING TO THE
GROUND.
PREVIOUS DISCUSSION:
LOW PROB FOR BRIEF SOUTHERLY GALES OVER EASTERN
WATERS THROUGH EARLY EVENING AS THE LOW LEVEL JET PEAKS ACROSS THE
WATERS. BUT LOW LEVEL INVERSION WILL LIMIT STRONGEST WINDS FROM
MIXING DOWN SO IT IS MORE LIKELY THAT GUSTS WILL REMAIN IN SCA
RANGE. BEST CHANCE FOR MARGINAL GALES MAY ACTUALLY OCCUR IN BOS
HARBOR THROUGH 9 PM. WINDS SHIFT TO NW AND DIMINISH OVERNIGHT WITH
SUBSIDING SEAS. NORTHERLY WINDS BELOW SCA TUESDAY. SEAS MOSTLY BELOW
SCA AS WELL BUT 5 FT SEAS MAY LINGER OVER OUTER SE WATERS.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
HIGH CONFIDENCE IN OVERALL WIND DIRECTION....BUT LOWER CONFIDENCE IN
WIND SPEEDS AND TIMING.
LOW PRESSURE TO THE SOUTH OF OUR WATERS WITH HIGH PRESSURE OVER THE
CANADIAN MARITIMES WILL RESULT IN A PERSISTENT EAST TO NORTHEAST
FLOW OF AIR MOST OF THE TIME. PERIODS OF 20 TO 25 KNOT NORTHEAST
WIND GUSTS ARE EXPECTED FOR MUCH OF THE PERIOD. WINDS MAY END UP A
BIT STRONGER FOR A TIME...DEPENDING ON HOW FAR NORTH MID ATLANTIC
LOW PRESSURE SYSTEM MAKES IT. IT DOES APPEAR THAT THE BEST CHANCE
FOR THE STRONGER WINDS WILL BE ACROSS OUR SOUTHERN ATLANTIC WATERS.
SCA SEAS ARE ALSO LIKELY FOR MUCH OF THE TIME ACROSS OUR SOUTHERN
AND SOUTHEAST ATLANTIC WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR CTZ002>004.
MA...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ002>019-026.
NH...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NHZ011-012-015.
RI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR RIZ001>004.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR ANZ231>235-237-
254>256.
GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR ANZ230-250-251.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ236.
&&
$$
SYNOPSIS...KJC/FRANK
NEAR TERM...FRANK
SHORT TERM...KJC
LONG TERM...FRANK
AVIATION...KJC/FRANK
MARINE...KJC/FRANK
AREA FORECAST DISCUSSION
NWS ALBANY NY
249 PM EDT MON OCT 7 2013
.SYNOPSIS...
A WARM AND HUMID AIR MASS WILL BRIEFLY BE OVER THE REGION THIS
AFTERNOON. A STRONG COLD FRONT WILL MOVE ACROSS THE AREA THIS
AFTERNOON AND EVENING WITH HEAVY RAIN SHOWERS...GUSTY WINDS AND
POSSIBLE STRONG TO SEVERE THUNDERSTORMS. BY TUESDAY...A
DRIER...COOLER AND LESS HUMID AIR MASS WILL RETURN FOR MUCH OF THE
UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 248 PM EDT...
TORNADO WATCH 543 REMAINS IN EFFECT UNTIL 5 PM EDT FOR ERN NY AND
NOW INCLUDES ALL OF WESTERN NEW ENGLAND. IT HAS BEEN EXPANDED TO
INCLUDE SRN VT...WRN MA...AND NW CT.
THE WIND ADVISORY REMAINS UP UNTIL 8 PM FOR ALL OF ERN NY AND WRN
NEW ENGLAND.
A COLD FRONT CONTINUES TO MOVE ACROSS ERN NY TOWARDS THE HUDSON
RIVER VALLEY. A HIGH SHEAR AND LOW CAPE ENVIRONMENT IS IN PLACE
ACROSS THE ALY FCST AREA WITH THE LATEST SPC MESO PAGE SHOWING
INSTABILITY VALUES LESS THAN 500 J/KG ACROSS MOST OF THE
AREA...WITH THE HIGHEST AMOUNTS ACROSS THE EXTREME SRN TIER. THE
0-6 KM BULK SHEAR VALUES HAVE INCREASED TO 40-65 KTS...WITH THE
LOW-LEVEL 0-1 KM SHEAR VALUES ALSO VERY IMPRESSIVE IN THE 30-45 KT
RANGE...WITH THE HIGHEST VALUES OVER THE NRN TIER. THE WIND
ADVISORY LOOKS GOOD...AND SOME BOWING SEGMENTS WITH THE LINE ECHO
WAVE PATTERN /LEWP/ UPSTREAM HAVE PRODUCED SOME ISOLD/SPORADIC
WIND DAMAGE UPSTREAM OVER W-CNTRL NY AND PA. THE UPPER TROUGH IS
TURNING NEGATIVELY TILTED...AND THERE IS A THREAT FOR SOME OF THIS
STRONG MOMENTUM TRANSFERRED DOWN FROM H925-H850. THE PAUCITY OF
INSTABILITY AND WEAK MID LEVEL LAPSE RATES HAVE INHIBITED CG
STRIKES. THERE IS A STRIKE HERE OR THERE UPSTREAM. DUE TO THE
DYNAMICALLY FORCED LEWP... THE POTENTIAL FOR SOME NEAR THUNDERLESS
OR THUNDERLESS SEVERE STORMS WILL CONTINUE UNTIL LATE THIS PM. THE
IMPACT PERIOD CONTINUES TO BE 1-5 PM FROM WEST TO EAST. THE LATEST
3-KM HRRR LINES UP WELL WITH THIS TIME FRAME. A BRIEF SPIN-UP
TORNADO MAY BE POSSIBLE ALONG THE LEWP DUE TO THE STRONG LOW-LEVEL
WIND SHEAR...DESPITE THE WEAK INSTABILITY.
A TOR WARNING WAS ISSUED FOR PARTS OF HERKIMER...NW FULTON...AND SW
HAMILTON COUNTY. SOME REPORTS OF WIND DAMAGE ARE COMING IN NEAR
STRATFORD IN NW FULTON COUNTY. SEVERAL SVRS ARE BEING ISSUED FOR
THE ALY FCST AREA AT THIS TIME.
THE NARROW COLD FRONTAL RAIN BAND /SHALLOW LINE OF CONVECTION/ SHOULD
BE EAST OF THE FCST AREA BY 6 PM. DESPITE THE CLOUD COVER...THE
FCST AREA IN THE WARM SECTOR...HAS ALLOWED TEMPS TO REACH THE MID
60S TO M70S OVER THE REGION. TEMP FALLS IN THE WAKE OF THE COLD
FRONT HAVE BEEN AS GREAT AS 15 DEGREES IN AN HOUR AT KSYR. A 46 KT
GUST OCCURRED ABOUT 3 HOURS AGO.
THE SHOWERS AND EMBEDDED TSTMS WILL LIKELY PRODUCE A PERIOD OF
VERY HEAVY RAINFALL...FOR GENERALLY LESS THAN 2 HOURS. THE SHOWERS
SHOULD GRADUALLY TAPER FROM W TO E AROUND OR JUST AFTER SUNSET.
RAINFALL RATES COULD REACH A HALF AN INCH TO AN INCH AN HOUR DUE
TO THE ANOMALOUS PWATS IN PLACE...AND THE STRONG CONVERGENCE WITH
THE BOUNDARY.
POPS...WX...AND TEMPS HAVE BEEN RETOOLED BASED ON THE
OBSERVATIONAL TRENDS IN THE FCST GRIDS AND THE TOR WATCH
EXPANSION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
TONIGHT...ANY SHOWERS ACROSS EXTREME S/E AREAS SHOULD END BY 10 PM EDT.
ADDITIONAL ISOLATED/SCATTERED SHOWERS COULD AFFECT THE WESTERN
ADIRONDACKS LATER THIS EVENING OR OVERNIGHT...AS THE UPPER LEVEL
COLD POOL PASSES ACROSS. OTHERWISE...EXPECT A PERIOD OF CLEARING
IN MOST AREAS THIS EVENING...BUT ADDITIONAL CLOUDS MAY FORM ONCE
AGAIN LATER TONIGHT AS THE COLD POOL PASSES BY...AND SOME LAKE
MOISTURE SPREADS INTO THE REGION...ESP FOR AREAS NEAR AND N OF
INTERSTATE 90. HAVE SIDED WITH THE SLIGHTLY WARMER MET MOS IN MOST
AREAS.
TUE-WED NT...GENERALLY DRY CONDITIONS ARE EXPECTED THROUGH THIS
PERIOD. THE ONE CAVEAT COULD BE LINGERING CLOUDS ACROSS NORTHERN
PORTIONS OF THE REGION TUESDAY...AS SOME LAKE MOISTURE BECOMES
TRAPPED BENEATH A RAPIDLY LOWERING SUBSIDENCE INVERSION. FOR NOW
HAVE INDICATED PARTLY TO MOSTLY SUNNY SKIES...BUT TRENDS WILL NEED
TO BE WATCHED...AS MUCH MORE CLOUD COVER THAN CURRENTLY FORECAST
COULD OCCUR FOR AREAS NORTH OF I-90. OTHERWISE...FOR
TEMPS...GENERALLY SIDED WITH THE COOLER MET MPS FOR TUE
MAXES...AND WENT A BIT WARMER THAN GUIDANCE FOR TUE NT MINS. SOME
FROST POTENTIAL WILL EXIST IN PORTIONS OF THE UPPER HUDSON
VALLEY...EASTERN CATSKILLS AND SOUTHERN VT...WHICH WILL BE
ADDRESSED IN THE HWOALY. SOME HIGH AND MID LEVEL CLOUDS COULD
SLOWLY EXPAND NORTH AND WEST INTO THE REGION LATE WED OR WED
NT...DEPENDING ON THE TRACK AND EVOLUTION OF A POSSIBLE LOW
PRESSURE SYSTEM DEVELOPING OFF THE SOUTHEAST COAST.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COMPLEX UPPER PATTERN SHOULD RESULT IN HIGHER UNCERTAINTY WITH
DETAILS IN THE LONG RANGE FORECAST. IN THE THURSDAY THROUGH FRIDAY
TIME FRAME...THERE IS A LOOSE CONSENSUS OF A COASTAL SYSTEM THAT
DEVELOPS OFF THE MID ATLANTIC AS UPPER RIDGING BUILDS NORTH AND EAST
INTO SOUTHEASTERN CANADA. MOST AREAS SHOULD BE UNDER THE INFLUENCE
OF HIGH PRESSURE THURSDAY AND FRIDAY. EXCEPT...THERE COULD BE SOME
CLOUDS AND ISOLATED SHOWERS IN THE SOUTHERN PARTS OF THE MID HUDSON
VALLEY AND NW CT...WHERE THERE COULD BE SOME ONSHORE FLOW DUE TO THE
PRESSURE GRADIENT DEVELOPING BETWEEN THE LOW LEVEL RIDGING OVER THE
NORTHEASTERN U.S. AND THE COASTAL SYSTEM OFF THE MID ATLANTIC. HIGHS
THURSDAY AND FRIDAY IN THE 60S TO NEAR 70.
THE UPPER PATTERN POTENTIALLY BECOMES EVEN MORE COMPLICATED AS LOW
LEVEL RIDGING BUILDS AND STRENGTHENS OVER SOUTHEASTERN CANADA AND
EASTERN NEW ENGLAND AND THEN BUILDS WEST INTO NY SATURDAY AND
SUNDAY. COOLER AIR ALSO BUILDS WEST INTO NY...POTENTIALLY RESULTING
IN A COOLING TREND BOTH DAYS. THE UPPER RIDGING INTO SOUTHEASTERN
CANADA MAY SUPPORT A SLIGHT NORTHWARD DRIFT TO THE UPPER FEATURE
ASSOCIATED WITH THE LOW PRESSURE OFF THE EAST COAST...WITH MORE OF A
PRESSURE GRADIENT AND ONSHORE FLOW IN SOUTHERN NY AND NW CT...
DEPENDING ON EXACTLY HOW FAR NORTH THE COASTAL FEATURE CAN GET. WITH
SUCH EXTREME SPREAD IN THE LONG RANGE GUIDANCE...GOING DRY FOR THE
WEEKEND WITH HIGHS IN THE 60S...BUT COOLING A DEGREE OR TWO EACH DAY
WITH THE COLD ADVECTION FROM THE EAST. MORE DETAILS WITH THIS
COMPLICATED PATTERN SHOULD BE APPARENT TOWARD THE END OF THE
WEEK...BUT AT LEAST THE RANGE OF POSSIBLE SENSIBLE WEATHER DOES NOT
INCLUDE ANY HIGH IMPACT OR THREATENING WEATHER FOR OUR FORECAST AREA
IN THE LONG RANGE...BUT SOME INCLEMENT WEATHER IS POSSIBLE DEPENDING
ON HOW/IF THE COASTAL SYSTEM EVOLVES.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
COLD FRONT MAKING STEADY PROGRESS ACRS NYS AND EXPECT THE FRONT TO
MOVE THROUGH THE TAF SITES IN THE 19Z-21Z TIME FRAME. GENERALLY
EXPECT MVFR/IFR JUST AHEAD OF AND BEHIND THE FRONT WITH GUSTY
WINDS AS WIND DIRECTION SHIFTS FROM S-SE AHEAD OF THE FRONT TO
WESTERLY BEHIND THE FRONT. WIND GUSTS MAY BE AS HIGH AS 35 KTS
WITH FROPA.
ONCE FROPA HAS TAKEN PLACE EXPECT A FEW HOURS OF MVFR CONDITIONS
WHICH WILL GIVE WAY TO VFR THIS EVENING. OVERNIGHT SKIES WILL
BECOME SKC WELL AFTER MIDNIGHT AND FOG IS EPXECTED TO DEVELOP AT
KGFL AND KPSF REDUCING CIGS AND VSBYS TO LIFR LATE AT NIGHT.
ON TUESDAY EXPECT SKC CONDITIONS WITH NORTH TO NORTHWEST WINDS OF
8-10 KTS.
OUTLOOK...
LATE TONIGHT-FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE ANTICIPATED OVER THE NEXT FEW DAYS.
AFTER A WETTING DAY ON SUNDAY...ANOTHER WETTING DAY WITH MORE RAIN
SHOWERS AND SCATTERED THUNDERSTORMS ARE LIKELY THIS AFTERNOON AND
EVENING. DRY WEATHER WILL RETURN TUESDAY THROUGH THE REMAINDER OF
THE WEEK...WITH FULL RH RECOVERY EXPECTED EACH NIGHT WITH
WIDESPREAD DEW FORMATION.
&&
.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.
A COLD FRONT WILL MOVE THROUGH THE REGION THIS AFTERNOON
AND EVENING. MAINLY ISOLATED TO SCATTERED SHOWERS ARE EXPECTED
THROUGH THIS MORNING WITH LIGHT PCPN AMOUNTS OF A TENTH OF AN
INCH OR LESS. MUCH HEAVIER RAINFALL IS EXPECTED WITH THE COLD
FRONT THIS AFTERNOON AND EVENING WITH THE POTENTIAL 0.75-1.5 INCH
BASIN RAINFALL AVERAGES. ALL THE MODELS ARE NOW SHOWING THE COLD
FRONT MOVING THROUGH QUICKLY...SO THERE APPEARS TO BE LITTLE IF
ANY CHANCE THAT THE FRONTAL BOUNDARY AND THE HEAVY RAIN LINGERING
OVER THE REGION AND PRODUCING MORE THAN TWO INCHES OF RAIN.
DUE TO RECENT DRY CONDITIONS...FFG IS QUITE HIGH...AND THE COLD
FRONT WILL BE MOVING FAST ENOUGH TO KEEP ANY HEAVY RAINFALL
LIMITED TO JUST A FEW HOUR PERIOD. AS A RESULT...NO HYDROLOGIC
PROBLEMS ARE ANTICIPATED OUTSIDE OF LOW LYING...POOR DRAINAGE...OR
URBAN AREAS THAT TYPICALLY SEE WATER POND DURING HEAVY DOWNPOURS.
DRY WEATHER WILL BE IN PLACE FOR TUESDAY THROUGH THE REMAINDER OF
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...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR CTZ001-013.
NY...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NYZ032-033-
038>043-047>054-058>061-063>066-082>084.
MA...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ001-025.
VT...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR VTZ013>015.
&&
$$
SYNOPSIS...KL/WASULA
NEAR TERM...WASULA
SHORT TERM...KL
LONG TERM...NAS
AVIATION...11/NAS
FIRE WEATHER...KL/GJM
HYDROLOGY...KL/GJM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
151 PM EDT MON OCT 7 2013
.SYNOPSIS...
WARM AND HUMID CONDITIONS ARE EXPECTED TODAY ALONG WITH GUSTY
SOUTHERLY WINDS. A BAND OF HEAVY SHOWERS...STRONG WINDS AND
PERHAPS ISOLATED THUNDERSTORMS ARE EXPECTED LATE THIS AFTERNOON
AND EVENING WITH A STRONG COLD FRONT. HIGH PRESSURE AND DRY
SEASONABLE WEATHER OVERSPREADS SOUTHERN NEW ENGLAND TUE AND WED. A
COASTAL LOW MAY BRING ANOTHER ROUND OF RAIN TO THE REGION LATER
THIS WEEKEND AND POSSIBLY INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
** GUSTY WINDS AND HEAVY RAINFALL WITH A COLD FRONT LATE TODAY **
145 PM UPDATE...
QLCS ALONG THE COLD FRONT APPROACHING E NY AND NW NJ. CONVECTION
HAS INTENSIFIED A BIT WITH LEWP STRUCTURE DEVELOPING WHICH IS A
GOOD INDICATOR OF STRONG WINDS. MESOANALYSIS INDICATING SBCAPES OF
500 J/KG AHEAD OF THE LINE IN SNE. HRRR IS HANDLING THIS FAIRLY
WELL AND BRINGS LINE INTO THE BERKSHIRES AND CT VALLEY 21-22Z
THEN WEAKENS IT AS IT APPROACHES THE COASTAL PLAIN THIS EVENING.
GREATEST THREAT FOR SEVERE WX WILL BE ACROSS W
ZONES...PARTICULARLY THE BERKSHIRES AND CT VALLEY. 0-1KM SR
HELICITY 300-400 M2/S2 ALONG AND JUST AHEAD OF THE LINE SO THE
THREAT OF AN ISOLD TORNADO CANT BE RULED OUT...ESPECIALLY IF WE
CAN GENERATE 500-1000 J/KG OF SFC BASED CAPE.
PREVIOUS DISCUSSION...
WARM FRONT STILL HUNG UP ACROSS THE INTERIOR FROM NEAR HFD TO
OWD. TEMPS HAVE RISEN INTO THE UPPER 60S TO LOWER 70S WITH
DEWPOINTS UPPER 60S S OF THE FRONT BUT TEMPS ARE STILL MOSTLY IN
THE 50S TO THE NORTH IN THE INTERIOR. WE EXPECT THE FRONT WILL
EVENTUALLY JUMP TO THE N AS THE LOW LEVEL INVERSION EVENTUALLY
MIXES OUT WITH TEMPS INCREASING RAPIDLY INTO THE 70S THIS
AFTERNOON IN THE INTERIOR.
THE WARM TEMPS WILL HELP TO INCREASE MIXING IN THE LOW LEVELS.
WITH DECENT LOW LEVEL JET ACROSS THE REGION...EXPECT INCREASING
WINDS THIS AFTERNOON WITH SOUNDINGS SUPPORTING GUSTS TO 35-40 KT.
EVEN IF THE WIND GUSTS FALL JUST SHORT OF ADVISORY CRITERIA...THE
FULLY LEAVED TREES WILL ENHANCE THE POTENTIAL FOR MINOR WIND
DAMAGE. AS A RESULT WE EXPANDED THE WIND ADVISORY FOR ALL SNE
EXCEPT THE IMMEDIATE S COAST WHERE MIXING WILL BE MORE SHALLOW.
THERE ARE A FEW SHOWERS LIFTING N ACROSS SNE BUT MOST OF THE AREA
IS DRY. THROUGH MID AFTERNOON...WE ARE JUST EXPECTING A FEW
SHOWERS FROM TIME TO TIME WITH MOSTLY DRY WEATHER AS MAIN ACTION
WILL BE TIED TO THE COLD FRONT LATE AFTERNOON AND EVENING. LINE OF
CONVECTION ALREADY DEVELOPING ALONG THE COLD FRONT ACROSS CENTRAL
NY AND PA AND HIRES MODELS SHOW A STRONG SIGNAL FOR A FINE LINE OF
CONVECTION ALONG THE FRONT MOVING INTO THE BERKSHIRES AND CT
VALLEY LATER TODAY.
RIGHT ENTRANCE REGION OF UPPER LEVEL JET WILL ENHANCE FORCING FOR
ASCENT AND COMBINED WITH LOW LEVEL JET EXPECT THE FRONTAL BAND OF
CONVECTION TO INTENSIFY AS IT MOVES EAST. WE HAVE A STRONGLY
SHEARED ENVIRONMENT LATER TODAY WITH 0-6KM SHEAR 50-60 KT.
INSTABILITY WILL BE THE LIMITING FACTOR BUT WITH TEMPS RISING
THROUGH THE 70S IT LOOKS LIKE SBCAPES WILL WILL REACH 500 J/KG
WITH LOW PROB OF CAPES APPROACHING 1000 J/KG. GIVEN HIGHLY SHEARED
ENVIRONMENT THIS INSTABILITY ENOUGH TO SUPPORT A FEW STRONG TO
SEVERE TSTMS WITH DAMAGING WINDS WITH THIS FINE LINE LATER
TODAY. IN ADDITION...0-1 KM SHEAR 40-45 KT AND 0-1KM HELICITY
300-400 M2/S2 WHICH IS VERY IMPRESSIVE SO CANT RULE OUT AN ISOLD
TORNADO IN THIS ENVIRONMENT.
THE TIMING OF THE FRONT IS 21-00Z ACROSS W ZONES.
BRIEF HEAVY RAINFALL WILL BE A SECONDARY THREAT...BUT PROGRESSIVE
NATURE OF THIS FRONT WILL LIMIT DURATION OF THE HEAVIEST RAINFALL
TO AN HOUR OR 2 WHICH WILL LIMIT FLOOD POTENTIAL. STILL...THE
HEAVY DOWNPOURS COULD LEAD TO AREAS OF URBAN AND POOR DRAINAGE
FLOODING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
TONIGHT...
THE LLJ AND COLD FRONT ARE EXPECTED TO LIFT AND LOSE A LITTLE OF
ITS PUNCH AS IT MOVES E...HOWEVER THE THREATS MENTIONED ABOVE
REMAIN UNTIL IT MOVES OFFSHORE BETWEEN AROUND 04Z.
AFTERWARD...ASIDE FROM NW WINDS GUSTING SOMEWHAT /ALTHOUGH NOT
NEARLY AS STRONG AS THE SOUTHERLY WINDS AHEAD AND ASSOCIATED WITH
THE FRONT/ CONDITIONS WILL RAPIDLY IMPROVE...WITH SOME CLEARING
EXPECTED ALMOST TO THE E COAST BY DAYBREAK. TEMPERATURES WILL
RAPIDLY DECLINE S WELL. DIPPING INTO THE 40S IN NW MA AND SRN NH.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...
* DRY AND SEASONABLE WEATHER TUE/WED
* CHANCE OF RAIN LATE WEEK INTO NEXT WEEKEND
SYNOPTIC OVERVIEW...
NORTHERN STREAM TROUGH OVER THE ST. LWRNC RVR VLY EXITS NORTHEAST
INTO THE MARITIMES TUE. MEANWHILE ITS ATTENDING COLD FRONT MOVES
OFFSHORE WITH POST FRONTAL AIRMASS OVERSPREADING SOUTHERN NEW
ENGLAND. BY WED DEEP LAYER RIDGE BUILDS OVER THE NORTHEAST AND IS
ACCOMPANIED BY 1030MB SURFACE HIGH. THEN FORECAST UNCERTAINTY
/ESPECIALLY TIMING/ INCREASE BY LATE IN THE WEEK AS LEFTOVER JET
ENERGY FROM TODAY/S EASTERN TROUGH FORMS A WEAK MID LEVEL LOW OVER
THE SOUTHEAST STATES. THIS STRENGTHENS ATTENDING SURFACE CIRCULATION
AS IT TRAVERSES NORTHWARD TO THE MID ATLC COAST BY LATE IN THE WEEK.
UPPER FLOW THEN BECOMES STAGNANT AS REX TYPE BLOCK DEVELOPS WITH
RIDGE /POSSIBLY CLOSED ANTICYCLONE/ OVER NEW ENGLAND AND SOUTHEAST
CANADA...ACCOMPANIED BY A CLOSED LOW OVER MID ATLC REGION OR JUST
OFFSHORE.
MODEL PREFERENCES...
GOOD MODEL AGREEMENT TUE AND WED WITH RIDGING DEVELOPING OVER THE
NORTHEAST. THEN MODEL SPREAD EVOLVES THU/FRI AND INTO NEXT WEEKEND.
THE 00Z GFS AND ITS ENSEMBLES /GEFS/ ARE ON THE FAST AND PROGRESSIVE
SIDE OF THE GUID ENVELOPE...BRINGING A COASTAL LOW WITH REMNANTS OF
KAREN NORTHWARD AND POSSIBLY IMPACTING SOUTHERN NEW ENGLAND WITH A
PERIOD OF RAIN AND WIND THU/FRI. THE 00Z EC IS MUCH SLOWER AND LESS
PROGRESSIVE WITH RAIN AND WIND HOLDING OFF UNTIL FRI OR SAT...
HOWEVER THEN POSSIBLY LINGERING PRECIP INTO SUN. THE GFS IS
STRONGER/MORE AMPLIFIED WITH THE NORTHERN STREAM AND AS A RESULT THE
COASTAL LOW IS KICKED SEAWARD SAT...SUPPORTING A DRYING TREND FOR
NEXT WEEKEND. THE GFS MAY BE CLOSER TO CONSENSUS GIVEN ITS ENSEMBLE
MEAN AND THE 00Z UKMET SUPPORT THIS PROGRESSIVE SOLUTION. ALTHOUGH
GIVEN THE TIME RANGE HERE AND MODEL SPREAD THINK LOW CHANCE AND
SLIGHT CHANCE POPS BETTER REFLECT THIS UNCERTAINTY...WITH HIGHEST
POPS ALONG THE SOUTH COAST. IN ADDITION...DID NOT FOLLOW LIKELY POPS
FROM GMOS THU INTO FRI FOR THE SAME REASON. INSTEAD STAYED CLOSE TO
THE MORE CONSERVATIVE HPC GUID POPS THURSDAY THROUGH SUNDAY.
SENSIBLE WEATHER...
TUE AND WED...DRY AND SEASONABLY COOL. MILDER TUE AS CORE OF COOLER
AIR SETTLES OVER THE REGION WED. LIGHTER WINDS WED AS 1032 MB HIGH
CREST ACROSS THE AREA. THE EXCEPTION WILL BE OVER CAPE COD AND THE
ISLANDS WHERE PGRADIENT WILL GET SQUEEZED A BIT YIELDING AT LEAST A
MODEST NE WIND THERE.
THURSDAY THROUGH SUNDAY...AS MENTIONED ABOVE LOTS OF UNCERTAINTY
HERE WITH POTENTIAL COASTAL STORM. MODEL CONSENSUS WOULD SUGGEST A
PERIOD OF WIND AND RAIN LATE THU INTO FRI...THEN POSSIBLY
IMPROVING/DRYING TREND OVER THE WEEKEND. ALTHOUGH WE WILL GO WITH
LOW CHANCE/SLIGHT CHANCE POPS TO REFLECT SOME UNCERTAINTY ON RAIN
CHANCES. TEMPS NEAR NORMAL BUT PERHAPS BELOW NORMAL IF RAIN MOVES
ONSHORE ESPECIALLY WITH ANY DURATION.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...HIGH CONFIDENCE IN TRENDS LOWER
CONFIDENCE IN TIMING.
CONDITIONS HAVE TEMPORARILY IMPROVED TO MVFR/VFR AS WARM FRONT HAS
LIFTED TO THE NORTH. INCREASING S WINDS WILL DEVELOP WITH GUSTS TO
35 KT POSSIBLE THROUGH THE REST OF THE AFTERNOON...EXPECIALLY AWAY
FROM S COAST. EXPECT IFR TO REDEVELOP LATER THIS AFTERNOON AND
EVENING AS LINE OF SHOWERS/TSTMS MOVE THROUGH. BRIEF HEAVY RAIN
AND STRONG WINDS WILL LIKELY ACCOMPANY THIS LINE OF
CONVECTION...ESPECIALLY CT VALLEY THEN GRADUALLY WEAKEN AS IT
MOVES TO THE COASTAL PLAIN. IMPROVING CONDIITONS TO VFR FROM WEST
TO EAST 03-08Z. VFR TUESDAY.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
EXACT TIMING. WIDESPREAD MVFR EXPECTED WITH A BRIEF PERIOD OF IFR
POSSIBLE THIS EVENING. BRIEF HEAVY RAIN POSSIBLE 23-03Z. WIND
GUSTS TO 35 KT THROUGH 00Z.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
EXACT TIMING. WIDESPREAD MVFR WITH A BRIEF PERIOD OF IFR POSSIBLE
LATE AFTERNOON AND EARLY EVENING. BRIEF HEAVY RAIN 21-00Z. WIND
GUSTS TO 35 KT POSSIBLE THIS AFTERNOON.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUE NIGHT/WED...VFR-DRY WEATHER WITH LIGHT WINDS...EXCEPT MODEST
NE WINDS CAPE COD AND THE ISLANDS. FORECAST CONFIDENCE HIGH.
THU/FRI...MVFR-IFR POSSIBLE IN PERIODS OF RAIN AS A COASTAL LOW
MOVES UP THE EASTERN SEABOARD. GUSTY NE WINDS POSSIBLE. FORECAST
CONFIDENCE LOW.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TONIGHT/...MODERATE CONFIDENCE.
SOUTHERLY WINDS WILL CONTINUE TO INCREASE THROUGH THE
DAY...LEADING TO SMALL CRAFT ADVISORY CONDITIONS OVER ALL THE
WATERS SAVE FOR THE NRN WATERS AND WATERS IMMEDIATELY ADJACENT TO
THE NORTHERN SHORELINES...WHERE SOME GUSTS TO GALE FORCE ARE
POSSIBLE. GIVEN THIS...HAVE ISSUED A GALE WARNING FOR THE NORTHERN
WATERS /SAVE FOR BOSTON HARBOR/ WITH SMALL CRAFT ADVISORIES
ELSEWHERE. WINDS WILL RAPIDLY SHIFT TO THE NW TONIGHT BEHIND A
COLD FRONT /WHICH MAY DELIVER SHORT LIVED GALE FORCE GUSTS ON ALL
WATERS/ BUT THE SMALL CRAFT ADVISORY CONDITIONS REMAIN INTO TUE
MORNING.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUE/WED...HIGH PRES MOVES ACROSS NORTHERN NEW ENGLAND. LIGHT WINDS
EXCEPT GUSTY NE WINDS SOUTHERN NEW ENGLAND WATERS. HIGH FORECAST
CONFIDENCE.
THU/FRI...A COASTAL STORM WILL LIKELY MOVE UP THE EASTERN SEABOARD.
UNCERTAIN HOW FAR NORTH AND DURATION. HIGHEST RISK OF STRONG
WINDS/LARGE SEAS AND HEAVY RAIN WILL BE SOUTH OF NEW ENGLAND. LOW
FORECAST CONFIDENCE.
&&
.HYDROLOGY...
THE THREAT FOR CONVECTION AND HIGH PWAT AIRMASS WILL COMBINE TO
YIELD A RISK FOR URBAN AND POOR DRAINAGE...AND POSSIBLY EVEN
SMALL STREAM FLOODING AT TYPICALLY FLASHY STREAMS LATE TODAY INTO
THE EARLY OVERNIGHT HOURS. THE STRONGEST LLJ AND HIGHEST MOISTURE
CONTENT WILL BE IN THE WEST...ESPECIALLY WEST OF A WILLIMANTIC-
WORCESTER-MANCHESTER LINE. THERE IS THE POTENTIAL FOR WIDESPREAD
1.0+ INCHES THERE...BUT LOCALLY HIGHER AMOUNTS APPROACHING 2.0
INCHES ARE POSSIBLE WITH ANY STORMS/HEAVY SHOWERS. EAST OF THE
LINE...WIDESPREAD RAINFALL OF 0.5-1.0 INCHES ARE POSSIBLE AS THE
LLJ WEAKENS AND DRIER AIR BUILDS IN...BUT AGAIN LOCALIZED HEAVIER
AMOUNTS ARE POSSIBLE. A PROLONGED DRY SPELL WILL HELP MITIGATE
THE THREAT...BUT GIVEN THAT ANY SHOWER OR STORM COULD BE
HEAVY...WILL NEED TO MONITOR RAINFALL RATES/TRENDS. FINALLY...ONE
OTHER NOTE IS THAT WITH LEAVES BEGINNING TO FALL...SOME CLOGGED
DRAINS MAY EXACERBATE NUISANCE FLOODING IN SOME LOCATIONS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR CTZ002>004.
MA...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ003>007-
010>019-026.
WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MAZ002-008-009.
NH...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NHZ011-012-015.
RI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR RIZ001>004.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR ANZ230>237-255-
256.
GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR ANZ250-251-254.
&&
$$
SYNOPSIS...NOCERA/DOODY
NEAR TERM...KJC
SHORT TERM...DOODY
LONG TERM...NOCERA
AVIATION...KJC/NOCERA
MARINE...NOCERA/DOODY
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
347 PM EDT MON OCT 7 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 346 PM EDT MON OCT 7 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF OVER THE
GREAT LKS SANDWICHED BTWN UPR RDG OVER THE ROCKIES/WRN PLAINS AND
ANOTHER RDG OFF THE E COAST. H925-85 THERMAL TROF ASSOCIATED WITH
REINFORCING SHRTWV DIGGING INTO THE UPR LKS AND MOIST LLVLS SHOWN ON
THE 12Z YPL RAOB HAVE BROUGHT QUITE A BIT OF CLD COVER TO MUCH OF
THE CWA...AND THERE HAVE EVEN BEEN A FEW -SHRA...MAINLY OVER THE E
HALF OF UPR MI. THE CLDS HAVE BEEN MORE SCT NEAR THE WI BORDER AND
ESPECIALLY THE SCENTRAL...WHERE LLVL NW FLOW BTWN SFC LO PRES MOVING
INTO QUEBEC AND HI PRES IN THE PLAINS IS DOWNSLOPING.
MAIN FCST CONCERNS IN THE SHORT TERM ARE MAINLY LO CLD TRENDS/TEMPS.
TNGT...SINCE THE UPR PATTERN IS RATHER PROGRESSIVE...MODELS SHOW UPR
RDG AXIS TO THE W SLIDING E AND OVER THE MS RIVER VALLEY BY 12Z
TUE... WITH SFC HI PRES SHIFTING INTO THE OH RIVER VALLEY. ALTHOUGH
LINGERING LLVL THERMAL TROF/CYC NW FLOW WL MAINTAIN SOME LO CLDS
OVER THE E HALF THIS EVNG...ARRIVAL OF SFC HI PRES RDG AXIS AND
BACKING LLVL FLOW TO THE W AND THEN SW WL CAUSE SKIES TO TURN MOCLR.
THERE COULD BE SOME MID/HI CLDS OVER MAINLY THE NW LATER IN THE
RETURN SW FLOW...BUT THE BULK OF THIS CLD SHOULD STAY IN CANADA.
EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR SCENTRAL...WHERE SKIES
WL BE MOCLR/WINDS LIGHTER THRU THE NGT.
TUE...THE CWA WL BE DOMINATED BY A STRONG SW FLOW UNDER SHARPENING
PRES GRADIENT BTWN SFC HI PRES MOVING INTO THE MID ATLANTIC STATES
AND SFC LO PRES IN SCENTRAL CANADA RIDING OVER THE UPR RDG. ALTHOUGH
SOME DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THIS FEATURE/WAD WL
BRUSH THE NW CWA...FCST SDNGS SHOW SO MUCH LO-MID DRY AIR THAT THE
ONLY IMPACT WL BE SOME HI CLDS. 12Z NAM/GFS SHOW SW H925 WINDS
INCRSG TO 45-50 KTS IN THE AFTN OVER THE WRN CWA TO THE S OF PRES
FALL CENTER OVER NW ONTARIO E OF THE SFC LO CENTER. MIXING TO H925
ON FCST SDNGS YIELDS HI TEMPS APRCHG 70 OVER THE W AND HINTS SOME
WIND GUSTS MAY AT LEAST APRCH ADVY CRITERIA AT EXPOSED LOCATIONS
OVER THE W.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 346 PM EDT MON OCT 7 2013
WITH THE UPPER TROUGH PEELING OUT OF THE UPPER GREAT LAKES REGION
TONIGHT...AN UPPER RIDGE WILL BUILD OVER THE EASTERN CONUS AND
REMAIN THROUGH THE END OF THE WORK WEEK. WITH A SURFACE HIGH OVER
THE NEW ENGLAND STATES AND A LOW MOVING THROUGH CENTRAL
CANADA...SOUTH-SOUTHWESTERLY FLOW WILL PULL WARM AIR OVER THE AREA.
THIS WILL LEAD TO ABOVE NORMAL TEMPERATURES (GENERALLY IN THE
MID 60S TO LOWER 70S) THROUGH THE END OF THE WORK WEEK. AS FOR
WEATHER...EXPECT DRY CONDITIONS DURING THIS PERIOD WITH GENERALLY
MOSTLY CLEAR SKIES. IT WILL STILL BE A LITTLE BREEZY ON WEDNESDAY AS
THE PRESSURE GRADIENT IS GRADUALLY WEAKENING DUE TO THE LOW IN
CANADA WEAKENING WHILE SHIFTING INTO THE CANADIAN MARITIMES. THERE
ARE SOME HINTS OF FOG IN THE NAM/SREF OVER THE SOUTH CENTRAL AND
EAST FOR WEDNESDAY NIGHT INTO THURSDAY MORNING. THE WEAKENING OF THE
PRESSURE GRADIENT OVER THE AREA THAT STARTS ON WEDNESDAY WILL
CONTINUE INTO WEDNESDAY NIGHT AND THURSDAY. SINCE SKIES WILL BE
CLEAR AND IT SEEMS LIKE A BETTER RADIATIONAL COOLING NIGHT
THAT MAY NOT BE TOO UNREASONABLE BUT DIDN/T ADD ANY FOG AT THIS
TIME.
AN UPPER TROUGH THAT DIVES INTO THE SOUTHWESTERN CONUS AROUND MID
WEEK WILL BE THE MAIN WEATHER MAKER FOR THIS WEEKEND. THIS TROUGH
WILL EJECT NORTHEAST INTO THE PLAINS ON FRIDAY AND THEN INTO THE
UPPER MISSISSIPPI VALLEY FRIDAY NIGHT INTO SATURDAY. THE SURFACE
LOW WILL FOLLOW A SIMILAR TRACK BUT THE CWA SHOULD STILL SEE AN
ASSOCIATED COLD FRONT AND SHOWERS SLIDE ACROSS THE AREA ON SATURDAY.
WILL CONTINUE TO SHOW THAT LINE OF SHOWERS SLIDING ACROSS THE CWA
LATE FRIDAY NIGHT AND SATURDAY WITH CHANCE POPS. DID PUT IN A
MENTION OF A RUMBLE OF THUNDER INTO THE GRIDS OVER THE SOUTH
CENTRAL...AS THERE IS A POCKET OF MARGINAL MUCAPE VALUES ALONG THE
FRONT (ALONG WITH SHOWALTER APPROACHING ZERO).
BEHIND THE UPPER TROUGH...MODEL DIFFERENCES REALLY BEGIN TO GROW ON
THE SMALLER SCALE FEATURES AFFECTING THE AREA. BUT THE LARGER SCALE
IDEA OF AN UPPER TROUGH OVER THE WESTERN 2/3RDS OF THE CONUS AND THE
UPPER GREAT LAKES REGION BEING ON THE EASTERN EDGE OF THE TROUGH.
00Z/12Z ECMWF/GEM RUNS ARE SHOWING A SECONDARY SHORTWAVE EJECTING
FROM THE UPPER TROUGH AND THROUGH THE UPPER GREAT LAKES REGION ON
SUNDAY INTO SUNDAY EVENING. 12Z GFS (LIKE IT/S PREVIOUS RUN) STILL
HOLDS ONTO THE DRIER IDEA AND NO SHORTWAVE MOVING THROUGH. SINCE IT
IS STILL A WAYS OFF...WILL FOLLOW A HIGH END SLIGHT AND LOW END
CHANCE CONSENSUS FOR THE POPS AND SEE WHICH WAY THE MODELS GO. IF
THE GEM/ECMWF SOLUTION PANS OUT...COULD SEE A DECENT RAINFALL FOR
PORTIONS OF THE CWA ON SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 122 PM EDT MON OCT 7 2013
LINGERING MVFR CIGS AT THE TAF SITES WL GIVE WAY TO VFR CONDITIONS
THIS AFTN WITH DAYTIME HEATING/MIXING AND THE APRCH OF HI PRES. THE
GUSTY NW WINDS WL DIMINISH BY THIS EVNG FOLLOWING THE LOSS OF
DAYTIME HEATING AND THE ARRIVAL OF A WEAKER PRES GRADIENT ASSOCIATED
WITH THE INCOMING HI PRES. ONCE THIS RDG SHIFTS TO THE E ON TUE...
EXPECT GUSTY S WINDS TO DVLP UNDER SHARPENING PRES GRADIENT IN THE
PRESENCE OF DAYTIME HEATING/MIXING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 346 PM EDT MON OCT 7 2013
EXPECT NW WINDS UP TO 20 TO 30 KTS LATE THIS AFTERNOON TO DIMINISH
STEADILY W-E TONIGHT AS A HI PRES RIDGE MOVES ACROSS LAKE SUPERIOR.
A STRONGER S FLOW...WITH WINDS UP TO 30 KTS...WILL THEN DOMINATE
LATER TUE/TUE NIGHT AS THE HI PRES SHIFTS TO THE E AND A SHARPER
GRADIENT BETWEEN THIS FEATURE AND A LO PRES SYSTEM MOVING THRU
SCENTRAL CANADA GETS SITUATED OVER THE UPPER LAKES. PLAN ON LIGHTER
S-SW WINDS WED THRU SAT AS THE HI TO THE E REBUILDS BACK TOWARD THE
AREA...RESULTING IN A WEAKER GRADIENT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1253 PM EDT MON OCT 7 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TODAY AND MOVE ACROSS THE
AREA TONIGHT. THE FRONT WILL STALL OFFSHORE WITH WEAK LOW PRESSURE
MOVING ALONG IT THROUGH THE END OF THE WEEK WHILE HIGH PRESSURE
EXTENDS OVER THE AREA FROM THE NORTH.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1250 PM MONDAY...SHOWERS WITH A FEW EMBEDDED TSTMS STARTING
TO IMPACT AREAS OF OUR FAR WESTERN CWA. LATEST 3KM HRRR IS RIGHT
ON THE MONEY WITH THE PLACEMENT OF THE PRECIPITATION AND SHOWS
THAT IT WILL GRADUALLY OVERSPREAD THE REGION OVER THE NEXT 3 OR 4
HOURS. INSTABILITY AND SHEAR REMAIN FOCUSED NORTH AND WEST OF OUR
CWA...BUT CANNOT RULE OUT SOME WIND GUSTS APPROACHING SEVERE
CRITERIA IN SOME OF THE STRONGER STORMS OVER THE NEXT 3 TO 6
HOURS. TEMPERATURES HAVE LIKELY REACHED THEIR AFTERNOON HIGHS IN
THE LOW TO MID 80S AND WILL LEVEL OFF AS CLOUDS AND PRECIPITATION
INCREASES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 330 AM MONDAY...NRN PORTION OF MID LVL TROF WILL LIFT N OF
AREA TONIGHT...BUT SRN PORTION WILL STILL BE WORKING OVER SE US.
WIDESPREAD SHOWERS AND ISOLD TSTMS EXPECTED TO AFFECT MAINLY WRN
SECTIONS THIS EVENING. FRONT WILL GRADUALLY PUSH ACROSS AREA
OVERNIGHT...AND DEVELOPING N TO NE LOW LVL WINDS COMBINED WITH
LINGERING MID LVL ENERGY FROM S-SW WILL LEAD TO HIGHEST POPS OVER
SRN PORTIONS AFTER MIDNIGHT. MOS BLEND FOR TEMPS...MAINLY LOW-MID
60S.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 330 AM MON...BY TUES MORNING THE SURFACE FRONT WILL BE
OFFSHORE WITH HIGH PRESSURE BUILDING EAST OVER THE MID-ATLANTIC
STATES. THE UPPER RIDGE OVER THE SOUTHERN CONUS WILL SHIFT EAST
TOWARDS THE CAROLINAS AS THE REMNANTS OF TS KAREN SLOWLY MOVE OVER
NORTHERN FL AND EVENTUALLY OFF THE GA/SC COAST. THE FRONT WILL
STALL OFFSHORE WITH A SURFACE LOW DEVELOPING OFF THE COAST. THE
LOW WILL SLOWLY MIGRATE NE ALONG/OFF THE COAST TUES NIGHT INTO
THURS PRODUCING AN UNSETTLED PATTERN ACROSS THE REGION. INCREASED
POPS TO NEAR CATEGORICAL TUES GIVEN GOOD MODEL AGREEMENT WITH
GOOD MOISTURE AND STRONG SHORTWAVE ALOFT. KEPT CHANCE POPS ACROSS
THE REGION WED THEN SLIGHT CHANCE INLAND/CHANCE EAST OF HWY 17 WED
NIGHT INTO THURS AS THE LOW MIGRATES NE. THE SLOW EVOLUTION OF
THIS PATTERN WILL LEAD TO A PROLONGED PERIOD OF GUSTY NE WINDS TO
THE COASTAL OBX AREAS.
UPPER LOW WILL DRIFT NORTH BY LATE WEEK TAKING BEST SHOWER CHANCES
WITH IT. BEST POPS WILL RESIDE IN THE NORTHEAST DURING THIS
PERIOD. THE UPPER LOW WILL SHIFT BACK OVER THE REGION SAT/SUN
YIELDING MORE CLOUDS/CHANCES FOR PRECIP. FOR TEMPS...EXPECT BE
BELOW CLIMO...ESPECIALLY FOR MAX TEMPS AS CLOUDS AND PRECIP KEEP
TEMPS DOWN INTO THE UPPER 60S TO NEAR 70 INLAND. LOWS WILL
GENERALLY BE IN THE 50S.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 12Z TUESDAY/...
AS OF 1250 PM MONDAY...SHOWERS AND SCATTERED TSTMS WILL BECOME
WIDESPREAD THROUGH MID TO LATE AFTN AHEAD OF APPROACHING COLD
FRONT AND CONTINUE THROUGH EVENING WITH CONDITIONS LOWERING TO
MVFR. SRLY WINDS WILL GUST TO AROUND 20 KT AHEAD OF THE FRONT.
MVFR CIGS WILL CONTINUE WITH PATCHY RAIN LATE TONIGHT AS WINDS
SHIFT TO N-NE BEHIND FRONT.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 320 AM MON...COLD FRONT WILL PUSH OFF THE NC COAST EARLY
TUES MORNING WITH SHOWERS CONTINUING TUES INTO WED. UNFAVORABLE
AVIATION CONDITIONS EXPECTED TO PERSIST TUES THROUGH WED WITH IFR
CONDITIONS POSSIBLE AS MOIST NORTHEAST FLOW DEVELOPS WITH UPPER
LOW LINGERING OVER THE VICINITY. WINDS WILL BE GUSTY AT TIMES AS
WELL WITH HIGH PRESSURE INLAND AND LOW PRESSURE OVER THE WATERS
PRODUCING A NE GRADIENT.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1250 PM MONDAY...WINDS GRADUALLY STARTING TO RAMP UP OVER
THE COASTAL WATERS AND SOUNDS AS THE FRONT EDGES CLOSER. MOST
AREAS WILL BE IN THE 15 TO 20 KNOT RANGE WITH SEAS IN THE 3 TO 5
FOOT RANGE. WINDS/SEAS INCREASE A BIT MORE OVERNIGHT WITH FREQUENT
GUSTS TO 25 KNOTS AND SEAS BUILDING TO AS HIGH AS 6 TO 7 FEET BY
LATER THIS EVENING. WINDS/SEAS WILL ALSO BE ELEVATED IN
CONVECTION.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 315 AM MON...COLD FRONT WILL RESIDE JUST ALONG THE COAST BY
EARLY TUES MORNING THEN SHIFT OFFSHORE THROUGHOUT THE DAY...WITH A
STRONG NE SURGE OF WINDS EXPECTED TO BUILD SOUTH OVER THE WATERS.
NE GRADIENT WILL PERSIST WED/THURS DUE TO HIGH PRESSURE OVER THE
NORTHEASTERN CONUS AND WEAK SURFACE LOW/REMNANTS OF TS KAREN OFF
THE SOUTHEASTERN COAST. NE WINDS WILL RANGE 20-25 KT TUES THROUGH
WED AFTERNOON. SEAS WILL RESPOND BY BUILDING 5-8 FT TUES/TUES
NIGHT ACROSS THE NORTHERN AND CENTRAL WATERS...WITH 4-7 FT EXPECTED
ACROSS THE SOUTHERN WATERS. WEAK SURFACE LOW SHIFTS NORTH TO OFF
THE NORTH CAROLINA COAST THURS INTO FRI...ACTING TO VEER WINDS
MORE N/NW AND DIMINISH SPEEDS TO 10-20 KT...HOWEVER...SEAS WILL
REMAIN ELEVATED THROUGH MID WEEK ESPECIALLY FROM DIAMOND SHOALS
NORTH. USED A BLEND OF PREVIOUS FORECAST WITH LATEST NON-GFS MODEL
BLEND FOR WINDS. FOR SEAS...UTILIZED LOCAL SWAN/NWPS THROUGH WED
THEN VERY SMALL ADJUSTMENTS TO PREVIOUS SEAS FORECAST FOR THURS/FRI
WHICH HAD ALREADY TAKEN INTO ACCOUNT THE KNOWN BIAS OF UNDER-FORECAST
SEAS FOR NE/N FLOW ACROSS THE CENTRAL AND NORTHERN WATERS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TUESDAY TO 4 PM EDT THURSDAY
FOR AMZ130-135.
SMALL CRAFT ADVISORY FROM 6 AM TUESDAY TO 4 AM EDT FRIDAY FOR
AMZ152-154.
SMALL CRAFT ADVISORY FROM 8 AM TUESDAY TO 4 PM EDT THURSDAY
FOR AMZ156-158.
SMALL CRAFT ADVISORY FROM 4 AM TUESDAY TO 4 AM EDT FRIDAY FOR
AMZ150.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...JBM/CTC/DAG
MARINE...JBM/DAG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
156 PM EDT MON OCT 7 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE NORTHEASTERN STATES WILL GIVE OUR
AREA A COOL NORTHEAST FLOW OF AIR THROUGH MUCH OF THE WEEK. EXPECT
LOW PRESSURE TO MOVE FROM THE GEORGIA COAST TO EASTERN NORTH
CAROLINA DURING MID WEEK AND STAY IN THAT VICINITY INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 10AM EDT MONDAY...BROKEN LINE OF CONVECTION CONTINUES TO PUSH
EAST OF THE I77 CORRIDOR INTO CENTRAL NC. A FEW LIGHT SHOWERS WILL
BE A POSSIBILITY OVER THE NEXT FEW HOURS BEHIND THE LEADING LINE.
THEREFORE KEPT CHANCE POPS THROUGH MIDDAY OUTSIDE OF THE MOUNTAINS.
OTHERWISE...DECIDED TO GO AHEAD AND LOWER POPS ACROSS THE HIGHER
TERRAIN AS THE FRONT PUSHES THROUGH ADVECTING IN MUCH MORE STABLE
AIR. SKY CONDITIONS WILL SLOWLY IMPROVE ACROSS THE MOUNTAINS
THROUGH THE DAY AS HIGH PRESSURE BUILDS IN BEHIND THE FRONT.
ELSEWHERE...CLOUDS WILL PERSIST THROUGH THE AFTERNOON HOURS AND INTO
MONDAY EVENING AS DEEP LAYER MOISTURE PREVAILS AHEAD OF THE FRONT.
OTHER THAN THE ABOVE MENTIONED POP/WX/SKY ADJUSTMENTS...NO OTHER
CHANGES WERE MADE TO THE FCST AT THIS TIME.
PREVIOUS DISCUSSION...
EARLY THIS MORNING...COLD FROPA IMMINENT WITH SFC TROUGH AND
CONVERGENCE LINE NOW EVIDENTLY JUST EAST OF THE TENN/NC BORDER.
SHORTWAVE IMPULSE LEADING THE CORE OF THE UPPER TROUGH IN THE
MODERATELY UNSTABLE ENVIRONMENT AHEAD OF THE FRONT CONTINUES TO
SUPPORT A FEW TSTMS...THE QLCS WHICH MOVED THRU THE FOOTHILLS
EARLIER THIS AM HAVING BECOME DISORGANIZED. STRONG LLVL SHEAR STILL
PRESENT AND THOUGH RAP ANALYSIS STILL INDICATES SOME INSTABILITY
LAPSE RATES MAY HAVE BECOME NEARLY NEUTRAL/MOIST ADIABATIC WITH THE
COLUMN SATURATING.
THE SHORTWAVE IS STILL MOVING INTO A MORE UNSTABLE ENVIRONMENT...ONE
THAT HAS LARGELY BEEN UNTOUCHED TONIGHT. THUS DEVELOPMENT OF
DISCRETE CONVECTION...MOSTLY SHOWERS WITH A LESSER NUMBER OF
TSTMS...MAY STILL BE EXPECTED THIS MRNG EAST OF A GREENWOOD TO
STATESVILLE LINE. TEMPS WILL LIKELY REMAIN NEARLY STEADY THRU
DAYBREAK...EXCEPT IN THE HIGHER MTNS WHICH MAY SEE SOME COOLER AIR
BEGIN TO FILTER IN.
TODAY...BOTH SYNOPTIC MODELS AND CAM CONSENSUS SHOW THE FRONT EXITING
THE ERN PERIPHERY OF THE CWFA IN 18-21Z TIMEFRAME. PROG SOUNDINGS
FROM CLT/HKY INDICATE MODEST INSTABILITY STILL PRESENT IN THE NC
PIEDMONT AT THAT TIME SO I ALLOWED POPS TO DROP OFF MORE QUICKLY IN
THE WEST WHERE THE FROPA WILL OCCUR EARLIER...HOLDING ONTO LIKELY
POPS EAST THRU PEAK HEATING. HIGHS TODAY HAVE BEEN HELD CLOSE TO A
CONSENSUS OF RAW MODEL TEMPS...WITH CLOUDY CONDITIONS EXPECTED TO
PERSIST MOST OF THE DAY.
TONIGHT...LATEST COUPLE MODEL CYCLES HAVE DECLINED TO DRY THINGS OUT
TOTALLY IN THE WAKE OF THE FRONT...RATHER FEATURING A FRONTAL WAVE
DEVELOPING NEAR THE SC/GA COAST AND SOME RETURNING MOISTURE OVERNIGHT
TONIGHT. THIS WAS HINTED AT FIRST BY THE EC A COUPLE DAYS AGO AND
OTHER MODELS GRADUALLY BOUGHT INTO THIS IDEA. IN LIGHT OF THE TREND I
ALLOWED POPS TO RISE AGAIN SOUTH/EAST OF I-85 TONIGHT. TEMPS WILL BE
NOTICEABLY COOLER...ESPECIALLY IN THE MTNS WHERE THE COOL AND DRY AIR
WILL ALREADY BE IN PLACE THIS EVENING. EVEN IN THE AFOREMENTIONED
AREA OF MORE CLOUDS AND POPS LOWS IN THE MID TO UPPER 50S ARE
EXPECTED.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 130 PM MON...LOW PRES OVER THE SE COASTAL WATERS TUE NIGHT
WILL PUSH ATLANTIC AND TROPICAL MOISTURE BACK INLAND ACROSS THE
COASTAL PLAIN OF THE CAROLINAS THROUGH WED. THE MAJORITY OF THE 12Z
MODEL RUNS KEEP THE HEAVY PRECIPITATION WITH THIS SYSTEM CONFINED TO
MAINLY COASTAL SECTIONS. HOWEVER...THE CANADIAN CMC AND A FAIR CHUNK
OF THE ENSEMBLE MEMBERS THROW A BIT MORE PRECIPITATION WESTWARD INTO
THE PIEDMONT TUE NIGHT/WED. WILL LEAN TOWARD THE MORE AGGRESSIVE
SOLUTION GIVEN THE HEALTHY PRESENTATION ON WATER VAPOR TODAY OF THE
WAVE THAT BECOMES THE COASTAL SYSTEM. DESPITE LEANING TOWARD THE
WETTER SIDE OF GUIDANCE...THE BL TO 850 MB FLOW WILL REMAIN NRLY
ENOUGH AROUND THE COASTAL SYSTEM TO KEEP QPF AMOUNTS DOWN AND NOT
ALLOW MUCH OF ANY UPSLOPE ENHANCEMENT INTO THE BLUE RIDGE THROUGH
WED NIGHT. THE MAIN FEATURE TO WATCH WOULD BE IF ANY BANDED SHOWERS
COULD WRAP BACK INTO THE CLT AREA. OTHERWISE...WILL CONTINUE TO
FEATURE A SMALLER THAN GUIDANCE DIURNAL RANGE ON TEMPS.
AS THE SYSTEM MOVES UP THE COAST TO THE OUTER BANKS ON
THU...MOISTURE MAY CONTINUE TO WRAP BACK WWD INTO THE NC PIEDMONT.
ANY ADDITIONAL QPF AMOUNTS WOULD BE LIGHT. WILL CONTINUE TO FEATURE
TEMPS BELOW GUIDANCE ON THU AFTN...BUT LESS SO THAN ON WED.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 140 PM MON FOR THE MEDIUM RANGE...THE UPPER LOW FEATURED IN
THE SHORT RANGE FCST HANGS AROUND OVER EASTERN NC AND VA INTO
SATURDAY THEN EITHER MOVES EAST OR NORTH DEPENDING ON MODEL CHOICE.
THIS LOW IS CLOSE ENOUGH TO PRODUCE SOME LIGHT PRECIP JUST EAST OF
OUR ZONES THURSDAY EVENING AND THEN HIGH PRESSURE TO OUR WEST AND
NORTH BECOMES MORE OF AN INFLUENCE. THE GFS AND ECMWF KEEP THE LOW
OVER EASTERN NC THROUGH SATURDAY. THE ECMWF THEN MOVES THE LOW NORTH
UP THE COAST TO MASS EARLY IN THE WEEK. THE GFS MOVES THE LOW EAST
AND THEN NORTH TOWARD NOVA SCOTIA. THE GFS KEEPS AN ALMOST
PERSISTENT LOW LEVEL NE WIND FLOW OVER OUR AREA THROUGH MOST OF THE
PERIOD. THE ECMWF HAS A MORE LIGHT AND VARIABLE WIND FLOW. SOME
SHORTWAVE ENERGY WILL BE CROSSING THE LOWER MISSISSIPPI VALLEY BY
MONDAY NIGHT AND INCREASE CLOUDS OVER NE GA AND THE MTNS. STILL
KEEPING IT DRY THROUGH THE PERIOD. TEMPERATURES WILL BE NEAR NORMAL
FOR THIS MEDIUM RANGE PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH THE
ONLY POSSIBLE EXCEPTION BEING FOR SCATTERED AFTERNOON TSRA. ADDED
AN MVFR TEMPO GROUP FROM 19Z-23Z TO ACCOUNT FOR LOW END INSTABILITY
ACROSS THE NC PIEDMONT THIS AFTERNOON. MODEL SOUNDINGS INDICATE
MARGINAL INSTABILITY THUS COULD NOT RULE OUT CONVECTION.
OTHERWISE...SKIES SHOULD REMAIN BKN/OVC THROUGH THE REMAINDER OF THE
TAF CYCLE AS MOISTURE AXIS ASSOCIATED WITH FRONTAL BOUNDARY STALLS
ALONG AND SOUTH OF THE I85 CORRIDOR. INITIALIZED WINDS OUT OF THE
WEST THEN VEERING NORTHWEST BY AROUND 19Z AS THE FRONT PUSHES
THROUGH. WINDS WILL REMAIN ELEVATED THROUGH THE EVENING AS HIGH
PRESSURE BUILDS IN FROM THE NORTH. AS THIS RIDGE BUILDS
OVERNIGHT...INCREASING PRESSURE GRADIENT FORCES WILL YIELD THE
POSSIBILITY FOR GUSTY WINDS IN THE MORNING. THUS ADDED MENTION OF
NORTHEAST GUSTS NEARING 20KTS THROUGH MIDDAY.
ELSEWHERE...VFR CONDITIONS SHOULD PREVAIL THROUGH THE ENTIRE TAF
CYCLE. WITH THAT SAID...DID INITIALIZE KAND WITH A BKN MVFR CIG
WHICH SHOULD NOT LAST BUT FOR MORE THAN AN HOUR OR SO.
OTHERWISE...SKIES SHOULD SLOWLY CLEAR IN THE LOW/MID LEVELS FROM
WEST TO EAST AS HIGH PRESSURE BUILDS IN BEHIND THE FRONT AT KAVL.
AS FOR OTHER LOCATIONS...KEPT MENTION OF LOW END VFR CIGS THROUGH
THE REMAINDER OF THE TAF CYCLE DUE TO PROXIMITY OF STALLED MOISTURE
AXIS. AS WITH KCLT ABOVE...WINDS WILL SHIFT NORTHWESTERLY THROUGH
THE FIRST FEW HORUS OF THIS TAF PERIOD AND WILL REMAIN ELEVATED
OVERNIGHT. THESE ELEVATED WINDS COMBINED WITH SFC DEWPOINTS IN THE
40S TO LOWER 50S WILL KEEP FOG CHANCES SLIM. WINDS WILL INCREASE
FURTHER AND VEER EASTERLY DURING THE MORNING HOURS WITH SOME GUSTING
AT KGSP AND KGMU.
OUTLOOK...MODERATELY SETTLED CONDITIONS WILL REMAIN THROUGH MIDWEEK
THOUGH A WEAK UPPER LEVEL LOW AND MOISTURE ASSOCIATED WITH THE
REMNANTS OF TROPICAL STORM KAREN MAY PRODUCE CIGS AND LIGHT
PRECIP...WITH POSSIBLE RESTRICTIONS IN SHOWERS. MORNING MTN VALLEY
FOG ALSO MAY IMPACT FLIGHT RULES LATER IN THE WEEK.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 98% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 97% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 87% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...HG
LONG TERM...DEO
AVIATION...CDG
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
239 PM CDT MON OCT 7 2013
.SHORT TERM.../NOW THROUGH TUESDAY NIGHT/...AS MR. RODGERS WOULD
SAY...IT IS A BEAUTIFUL DAY IN THE NEIGHBORHOOD...AND IT WILL REMAIN
BEAUTIFUL THROUGH THE SHORT TERM PERIOD. MID LEVEL RIDGE MOVES INTO
WESTERN TEXAS AND SURFACE RIDGE PARKS ITSELF OVER SOUTH TEXAS
TONIGHT. ATMOSPHERE REMAINS VERY DRY WITH THE LIGHT OFFSHORE FLOW
CONTINUING INTO TUESDAY BEFORE VEERING SOUTHEAST TUESDAY NIGHT. WARM
DAYS AND COOL NIGHTS CONTINUE UNDER THE CLEAR SKIES AND LOW DEW
POINT AIR. MODEL TEMPERATURES GUIDANCE REMAINS CONSISTENT BUT WILL
TREND SLIGHTLY LOWER FOR OVERNIGHT LOWS AS EXCELLENT RADIATIONAL
COOLING TAKES PLACE. A FEW DEGREES WARMER ON TUESDAY WITH FORECAST
NUMBERS NOT STRAYING TO FAR GUIDANCE.
AS WE HEAD INTO TUESDAY NIGHT SOUTHEAST WINDS RETURN ALBEIT WEAK.
SOMEWHAT MODEST LOW LEVEL MOISTURE ADVECTION IN THE LOWER 3000
FEET...LIGHT WINDS AND MOSTLY CLEAR SKIES COULD RESULT IN SOME
PATCHY GROUND FOG BY SUNRISE WEDNESDAY. UNSURE IF MOISTURE ADVECTION
WILL BE SUFFICIENT FOR DENSE FOG FORMATION BUT VISIBILITIES COULD
LOWER BELOW 1 MILE IN THE MORE FAVORED LOCATIONS IN THE KHBV KBKS
AREAS. OVERNIGHT NIGHT LOWS WILL BE WARMER BUT STILL BELOW GUIDANCE
VALUES WITH THE WEAK RETURN FLOW NOT ADDING MUCH WARM AIR ADVECTION
AT THIS TIME. ENJOY IT NOW A/C MAY HAVE TO CRANKED UP SOON.
.LONG TERM.../WEDNESDAY THROUGH MONDAY NIGHT/...
UPPER LEVEL TROUGH OVER THE WESTERN U.S. WILL DEPEND AND LIFT TO
THE NORTHEAST ACROSS THE FOUR CORNERS REGION THURSDAY INTO FRIDAY.
AT THE SURFACE...STRONG SURFACE LEE TROUGH DEVELOPS ENHANCING THE
SOUTHEAST FLOW FROM THE CENTRAL PLAINS SOUTHWARD INTO SOUTH TEXAS
REGION. EXPECT THIS BREEZE AFTERNOON THROUGH THURSDAY. WARM FRONT
OVER THE SOUTHERN GULF WILL LIFT N/NW AS RIDGE BUILDS ACROSS THE
REGION. THIS SURFACE LOW WILL SURGE DEEP LAYER MOISTURE FROM THE
SOUTHERN GULF INTO THE CWA THURSDAY AND FRIDAY. THE 1000 TO 500 MB
RH VALUES SHOWS AN INCREASE BETWEEN 60 TO 70 PERCENT THROUGH THE
WEEKEND AS THE UPPER LEVEL LOW INTERACTS WITH RIDGE OVER SOUTH
TEXAS. THIS WILL ENHANCE THE CHANCE OF SHOWERS AND THUNDERSTORMS TO
DEVELOP OVER THE CWA FRIDAY AND INTO THE WEEKEND. DECIDED TO INCREASE
POP FORECAST TO 20 PERCENT AT THIS TIME SINCE THERE IS GOOD AGREEMENT
AND CONSISTENCY WITH THE GFS/ECMWF MODEL RUN. THE COASTAL COUNTIES
ARE MORE FAVORABLE TO RECEIVE SOME RAINFALL FROM THIS MOISTURE
SURGE. DAYTIME HIGHS WILL GRADUALLY WARM TO THE MID 90S THROUGH THE
END OF THE LONG TERM FORECAST.
BY NEXT WEEK...GULF MOISTURE WILL RAP AROUND THE PERIPHERY OF THE
HIGH AND ENHANCE THUNDERSTORM ACTIVITY ALONG THE SIERRA MADRE AND
CENTRAL TEXAS. THIS AREA OF CONVECTION WILL CONTINUE INTO TUESDAY
UNTIL THE NEXT UPPER TROUGH DEEPENS PUSHING ALL THE MOISTURE OUT OF
THE AREA POSSIBLY BY MID WEEK.
&&
.MARINE...NOW THROUGH TUESDAY NIGHT...EXCELLENT MARINE CONDITIONS
THROUGH TUESDAY NIGHT WITH SURFACE HIGH PRESSURE SETTLING OVER THE
COASTAL WATERS. LIGHT NORTHEAST WINDS TONIGHT TO VEER EAST TUESDAY
THEN SOUTHEAST TUESDAY NIGHT. SEAS CONTINUE TO FALL TONIGHT
LOWERING TO 2 FEET OR LESS TUESDAY.
WEDNESDAY THROUGH MONDAY NIGHT...
SOUTHEAST WINDS RETURN WEDNESDAY AS THE HIGH PRESSURE BUILDS ACROSS
THE AREA. THIS SOUTHEAST FLOW WILL INCREASE THURSDAY INTO FRIDAY AND
BUILD SEAS BELOW ADVISORY CRITERIA THROUGH THE END OF THE WEEK. AN
AREA OF LOW PRESSURE WILL MOVE NORTHWARD INTO THE MARINE ZONES THURSDAY
INTO FRIDAY ENHANCING THE MOISTURE CONTENT IN THE AREA. THE BEST CHANCE
OF SHOWERS AND THUNDERSTORMS WILL BE SATURDAY THROUGH MONDAY OVER
THE GULF WATERS AS THE ABUNDANT MOISTURE WILL BE HIGHEST OVER THE MARINE
ZONES. NO SCA OR SCEC EXPECTED AT THIS TIME THROUGH MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 60 87 68 88 / 0 0 0 0
BROWNSVILLE 59 88 66 90 / 0 0 0 0
HARLINGEN 56 89 64 90 / 0 0 0 0
MCALLEN 59 91 66 91 / 0 0 0 0
RIO GRANDE CITY 58 91 65 92 / 0 0 0 0
SOUTH PADRE ISLAND 68 84 74 87 / 0 0 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
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