Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/10/14
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
445 AM PDT MON SEP 8 2014
.SYNOPSIS...
MONSOONAL MOISTURE WILL REMAIN IN PLACE INTO TUESDAY WITH MAINLY
AFTERNOON AND EARLY EVENING THUNDERSTORMS IN THE MOUNTAINS AND
DESERTS THROUGH TUESDAY AND ALSO IN THE INLAND EMPIRE THIS
AFTERNOON. DRYING WITH SEASONAL TEMPERATURES IS EXPECTED FOR
WEDNESDAY INTO NEXT WEEKEND. WEAK EASTERLY MID LEVEL FLOW COULD
BRING SOME MOISTURE AND AFTERNOON CLOUDS TO THE MOUNTAINS AT TIMES
FROM WEDNESDAY INTO NEXT WEEKEND.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
RADAR IMAGERY SHOWS WIDELY SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS DEVELOPING EARLY THIS MORNING ACROSS SOUTHERN
CALIFORNIA. GENERALLY FROM THE SAN DIEGO COUNTY COASTAL WATERS
ACROSS FAR NORTHERN SAN DIEGO COUNTY AND THE CENTRAL COACHELLA
VALLEY NORTHWARD. THIS IS AN AREA OF DIFLUENCE AHEAD THE TROUGH OF
LOW PRESSURE MOVING SOUTHWARD ALONG THE NORTHERN CALIFORNIA COAST.
THE 00Z ECMWF SHOWED SOME INDICATIONS OF THIS POSSIBILITY VERSUS
PREVIOUS RUNS AND THE 08Z RUN OF THE EXPERIMENTAL NCEP VERSION OF
THE HRRR TAKES THE CONVECTION OVER THE NORTHERN COACHELLA VALLEY AND
MOVES IT NORTHEASTWARD THIS MORNING.
THE COVERAGE OF THIS ELEVATED CONVECTION IS LIMITED ENOUGH AND THE
MOVEMENT TOWARD THE NORTHEAST AND EAST SUFFICIENT TO MOST LIKELY
KEEP RAINFALL COVERAGE EARLY THIS MORNING LIMITED AND NOT TOO HEAVY.
THE GREATEST POTENTIAL FOR LOCALLY HEAVY RAINFALL AND FLASH FLOODING
EARLY THIS MORNING WILL BE OVER THE DESERTS...ESPECIALLY THE
NORTHERN AND CENTRAL COACHELLA VALLEY NORTHEASTWARD.
HOWEVER...WITH DAYTIME HEATING THE FOCUS IS EXPECTED TO SHIFT
FARTHER INLAND FROM LATE MORNING THROUGH THE AFTERNOON AND EARLY
EVENING. PRECIPITABLE WATER VALUES REMAIN NEAR 2.4 INCHES IN THE
LOWER DESERTS AND 1.7 INCHES WEST OF THE MOUNTAINS. TODAY...SEA
BREEZE CONVERGENCE BOUNDARIES ARE EXPECTED TO DEVELOP NEAR OR
SLIGHTLY INLAND OF THE MOUNTAIN RIDGE TOPS...THEN MIGRATE INTO THE
DESERTS DURING THE AFTERNOON WITH THE SEA BREEZE. THUNDERSTORMS ARE
EXPECTED TO DEVELOP IN THE MOUNTAINS DURING THE LATE MORNING OR
EARLY AFTERNOON...THEN MIGRATE TOWARD THE DESERTS DURING THE
AFTERNOON THROUGH EARLY EVENING. THUNDERSTORMS MAY ALSO DEVELOP IN
PORTIONS OF THE INLAND EMPIRE IN THE AFTERNOON ALONG THE ELSINORE
CONVERGENCE ZONE. GIVEN THE HIGH MOISTURE CONTENT OF THE ATMOSPHERE
AND SLOW MOVEMENT OF STORMS...THERE IS A HIGH POTENTIAL FOR HEAVY
RAINFALL AND FLASH FLOODING FROM THUNDERSTORMS THIS
AFTERNOON...ESPECIALLY ALONG THE EAST SLOPES OF THE MOUNTAINS AND
ADJACENT DESERT AREAS. THE 06Z 4-KM VERSION OF THE NAM APPEARS TO
SHOW THIS WELL.
FOR LATE TONIGHT AND EARLY TUESDAY...MOISTURE FROM THE MID LEVEL
REMNANTS OF FORMER HURRICANE NORBERT (NOW A POST TROPICAL LOW) WILL
MOVE ACROSS NORTHERN BAJA AND FAR SOUTHERN CALIFORNIA. THE 06Z NAM
DOES DEVELOP SOME PRECIPITATION LATE TONIGHT INTO EARLY
TUESDAY...MAINLY IN PORTIONS OF SAN DIEGO COUNTY.
WHILE DRYING WILL BE UNDERWAY ON TUESDAY...THUNDERSTORMS ARE
EXPECTED DURING THE AFTERNOON OVER THE MOUNTAINS AND
DESERTS...MAINLY FROM THE MOUNTAIN RIDGE TOPS INTO THE DESERTS.
DECREASING MOISTURE AND A LITTLE FASTER STORM MOVEMENT SHOULD
REDUCE THE POTENTIAL FOR FLASH FLOODING A LITTLE.
DRIER WEATHER WITH SEASONAL TEMPERATURES WILL PREVAIL FOR WEDNESDAY
INTO NEXT WEEKEND. WEAK EASTERLY MID LEVEL FLOW COULD BRING SOME
MOISTURE AND AFTERNOON CLOUDS TO THE MOUNTAINS AT TIMES FROM
WEDNESDAY INTO NEXT WEEKEND.
&&
.AVIATION...
080900Z...COAST/VALLEYS...VFR CONDITIONS CONDITIONS WILL CONTINUE
THROUGH THIS EVENING...WITH SCT/BKN MID AND HIGH CLOUDS. THE CLOUD
DECK MAY LOWER TO BETWEEN 2000-4000 FT MSL AFT 09/0300Z.
MTNS/DESERTS...VFR CONDITIONS WILL CONTINUE THROUGH THIS MORNING.
HOWEVER...AFT 08/1800Z...CUMULUS WILL BEGIN TO BUILD OVER THE HIGHER
TERRAIN WITH BASES AROUND 6000 FT MSL AND TOPS ABV 25000 FT MSL.
ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP OVER THE RIDGE
TOPS...EVENTUALLY PUSHING INTO THE DESERTS. THESE STORMS WILL BE
CAPABLE OF PRODUCING GUSTY ERRATIC WINDS...STRONG
UP/DOWNDRAFTS...REDUCED VIS FROM HEAVY RAIN AND LIGHTNING.
CONDITIONS WILL IMPROVE BY THIS EVENING.
&&
.MARINE...THERE IS NO SIGNIFICANT MARINE WEATHER EXPECTED THROUGH
SATURDAY.
&&
.BEACHES...
200 AM...ELEVATED SURF AND STRONG RIP CURRENTS WILL CONTINUE THROUGH
TONIGHT DUE TO A LONG-PERIOD SOUTH SOUTHEAST SWELL. SETS TO 7 FEET
WILL BE POSSIBLE...MAINLY ON SOUTHERLY FACING BEACHES. A BEACH
HAZARD STATEMENT REMAINS IN EFFECT THROUGH TONIGHT.
&&
.SKYWARN...
SKYWARN ACTIVATION IS REQUESTED FOR THE LATE MORNING THROUGH EARLY
EVENING TODAY FOR THE MOUNTAINS...DESERTS...AND INLAND EMPIRE.
SPOTTER ACTIVATION MAY BE NEEDED AGAIN TUESDAY AFTERNOON FOR THE
MOUNTAINS AND DESERTS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR THE APPLE AND
LUCERNE VALLEYS...COACHELLA VALLEY...RIVERSIDE COUNTY
MOUNTAINS...SAN BERNARDINO COUNTY MOUNTAINS...SAN DIEGO COUNTY
DESERTS...SAN DIEGO COUNTY MOUNTAINS.
BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR THE BEACHES IN
THE ORANGE COUNTY COASTAL AREAS...SAN DIEGO COUNTY COASTAL
AREAS.
FLASH FLOOD WATCH FROM 10 AM PDT THIS MORNING THROUGH THIS
EVENING FOR THE SAN BERNARDINO AND RIVERSIDE COUNTY
VALLEYS-THE INLAND EMPIRE.
PZ...NONE.
&&
$$
PUBLIC...17
AVIATION/MARINE/BEACHES...JT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
341 PM MDT MON SEP 8 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM MDT MON SEP 8 2014
...LOCALIZED FLASH FLOOD POTENTIAL ALONG THE CONTINENTAL DIVIDE
TONIGHT...
CONVECTION HAS BEEN SLOW TO GET GOING ACROSS THE AREA TODAY...IN
PART BY CLOUD COVER OUT WEST WHICH HAS HINDERED HEATING...AND IN
PART BY FALLING DEW POINTS ACROSS THE I-25 CORRIDOR AND SOUTHEAST
PLAINS WHICH HAS LIMITED CAPE. LOCAL HRRR BREAKS OUT STRONGER
CONVECTION ACROSS THE MOUNTAINS DURING THE LATE AFTERNOON AS WELL AS
ALONG A SFC TROF AXIS ACROSS THE SOUTHEAST PLAINS. OVERALL...CAPES
ARE NOT ALL THAT HIGH...SO THINK THIS CONVECTION WILL BE ON THE WEAK
SIDE. HOWEVER...THERE IS SUFFICIENT MOISTURE IN THE ATMOSPHERE FOR
HEAVY ENOUGH RAINFALL TO CAUSE PROBLEMS FOR BURN
SCARS...PARTICULARLY OUT WEST WHERE THEY ARE STEADILY INCREASING.
INTERESTINGLY...HRRR SEEMS TO BE BACKING OFF ON QPF ACROSS THE
SOUTHWEST MOUNTAINS THIS AFTERNOON BUT NAM12 AND OTHER VARIOUS HIGH
RES MODELS STILL SUGGEST THE THREAT IS THERE.
GREATER THREAT FOR FLASH FLOODING FOR THE SOUTHWEST MOUNTAINS STILL
APPEARS TO COME IN DURING THE OVERNIGHT HOURS AS THE SHORTWAVE
ACROSS EAST CENTRAL AZ LIFTS SLOWING TO THE NORTHEAST INTO NRN NM
OVERNIGHT. ALSO WATCHING A VERY DISCERNIBLE SHORTWAVE ACROSS
WESTERN UT WHICH WILL BE MOVING ACROSS THE AREA AT THE SAME TIME
THAT MONSOON MOISTURE ADVECTS INTO THE SOUTHWEST MOUNTAINS.
PRECIPITABLE WATERS INCREASE TO NEAR AN INCH AT PAGOSA SPRINGS AS H7
WINDS IN THE NAM INCREASE FROM THE SOUTHWEST. THIS COMPONENT
PROVIDES THE MOST FAVORABLE UPSLOPE COMPONENT INTO THE EASTERN SAN
JUAN MOUNTAINS. ALL THIS SHOULD MEAN SHOWERS AND THUNDERSTORMS WILL
EXPAND IN AREAL COVERAGE OVERNIGHT (AFTER 06Z) AS LIFT AND MOISTURE
INCREASE WITH THE INCOMING WAVES. ALTHOUGH THE MODELS PORTRAY
VARIOUS SCENARIOS AS TO WHERE THE QPF MAXIMUM WILL OCCUR...THERE ARE
SUFFICIENT SIGNALS IN THE MODEL DATA TO SUGGEST A HEAVY RAINFALL
POTENTIAL SIGNIFICANT ENOUGH TO WARRANT A FLASH FLOOD WATCH FOR THE
EASTERN SAN JUAN MOUNTAINS WERE UPSLOPE MAY REGENERATE SHOWERS AND
THUNDERSTORMS WHICH COULD TRAIN OVER THE SAME SPOTS AS THEY MOVE OFF
TO THE NORTHEAST. STORM MOTIONS SHOULD BE FAST...BUT REPETITIVE
RAINFALL ON THE SAME LOCATION MAY CAUSE FLASH FLOOD PROBLEMS WITH
THE WEST FORK BURN SCAR BEING MOST UNDER THE GUN. REALLY CAN`T RULE
OUT HEAVY RAIN ANYWHERE ACROSS WESTERN PORTIONS OF THE FORECAST
AREA...BUT THREAT SEEMS HIGHEST ACROSS THE SOUTHWEST MOUNTAINS DUE
TO THE UPSLOPE AND PROXIMITY TO THE BURN SCAR SO WILL LIMIT FLASH
FLOOD WATCH TO THAT AREA FOR NOW.
ONE WAVE OF PRECIPITATION WILL SPREAD EASTWARD ACROSS THE AREA LATE
TONIGHT...WITH SCATTERED SHOWERS SPREADING INTO THE PIKES PEAK
REGION TOWARDS DAWN. THIS INITIAL BATCH STILL LOOKS RATHER LIGHT AS
IT MOVES EAST OF THE CONTDVD...AND QUICKLY SKIRTS OFF TO THE EAST
DURING THE MORNING. THEN THE MAIN PACIFIC TROF MOVES IN DURING THE
AFTERNOON. THIS SHOULD ENHANCE SHOWERS AND THUNDERSTORMS OVER THE
MOUNTAINS AGAIN DURING THE AFTERNOON WHICH WILL KEEP THE THREAT FOR
LOCALIZED FLASH FLOODING GOING ACROSS THE SOUTHWEST MOUNTAINS.
STILL NOT STRONG ENOUGH SIGNALS TO SUGGEST FLASH FLOODING FOR THE
SOUTHEAST MTS/PLAINS. LOW LEVEL WINDS ARE WESTERLY WHICH IS
DOWNSLOPE...AND AS A RESULT...DEW POINTS...WHICH DO INCREASE
SOME...ARE STILL ONLY IN THE 40S. THIS RESULTS IN CAPES OF ONLY A
FEW HUNDRED J/KG DURING THE AFTERNOON. SHOWERS AND THUNDERSTORMS
WILL MOVE OFF THE MOUNTAINS DURING THE AFTERNOON...AND WILL ALSO
BECOME FOCUSED ALONG A FRONT WHICH DROPS SOUTH OF THE PALMER DIVIDE
BETWEEN 21Z AND 00Z. CONVECTIVE BULLS-EYES ACROSS THE SOUTHEAST
PLAINS MEANDER FROM RUN TO RUN...BUT PARAMETERS ARE NOT FAVORABLE TO
PIN PRECIPITATION TO THE SOUTHEAST MOUNTAINS LONG ENOUGH TO CAUSE
PROBLEMS. STORM MOTIONS WILL BE TO THE EAST AT A PRETTY GOOD CLIP.
WILL KEEP MAINLY ISOLATED POPS FOR THE PLAINS DURING THE
AFTERNOON...WITH POPS INCREASING INTO THE EVENING HOURS AS THE FRONT
MOVES THROUGH.
TEMPERATURES TONIGHT WILL BE MILD WITH INCREASING CLOUD COVER.
HIGHS ON TUESDAY WILL BE COOLER OUT EAST WITH MORE WIDESPREAD
PRECIPITATION. MEANWHILE...WESTERLY DOWNSLOPE WINDS WILL BATTLE
CLOUD COVER AT TIMES ACROSS THE SOUTHEAST PLAINS...BUT OVERALL KEPT
MAX TEMPERATURES ON THE WARM SIDE. -KT
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM MDT MON SEP 8 2014
.TUESDAY NIGHT AND WEDNESDAY...SHOWERS AND THUNDERSTORMS WILL
LINGER INTO THE EVENING AS THE TROUGH PASSES THOUGH FROM THE
NORTHWEST. ANY CAPE SHOULD END BY LATER IN THE EVENING AS THE
COOLER MORE STABLE AIR MOVES INTO THE REGION. OVER THE
MOUNTAINS...LOWER LEVEL COLD AIR WILL BE TOO SHALLOW TO PASS OVER
THE EASTERN MOUNTAINS. KEPT SCATTER POPS OVER THE MOUNTAINS
OVERNIGHT AND INTO WEDNESDAY MORNING AS TROUGH WILL NOT PASS
THROUGH THE REGION UNTIL EARLY WEDNESDAY. ON WEDNESDAY...DRIER
AIR MASS ALOFT MOVES INTO THE REGION. ON THE PLAINS...ANOTHER
SURGE OF COOLER AIR MOVES INTO THE REGION BEHIND THE TROUGH.
ATMOSPHERE WILL BE TOO STABLE OVER THE PLAINS DURING THE DAY.
BUKFIT SOUNDINGS SUGGEST THERE MAY BE ENOUGH HEATING FOR SOME
LATER AFTERNOON THUNDERSTORMS ALONG THE INTERSTATE 25 CORRIDOR AND
OVER THE EASTERN MOUNTAINS. BY THE EVENING...THE COOL AIR ON THE
PLAINS MAY BECOME DEEP ENOUGH TO PRODUCE SOME VERY LIGHT SHOWERS
AND KEPT ISOLATED POPS IN THE GRIDS.
.THURSDAY AND FRIDAY...MODELS AND ENSEMBLES AGREE ON HAVING A
SHARPER TROUGH PASSING OVER THE REGION LATE THURSDAY INTO FRIDAY.
EC IS SLOWER...DEEPER AND COLDER WITH THE TROUGH. EC HAS 700MB
APPROACHING -4C OVER EL PASO COUNTY FRIDAY MORNING WHILE GFS IS
CLOSER TO +2C. ANTICIPATE A REASONABLE CHANCE OF LIGHT RAIN
THURSDAY EVENING AS THE TROUGH APPROACHES WITH THE COLD FRONTAL
PASSAGE. EC SOLUTION SUGGEST A BETTER CHANCE FOR PRECIPITATION THURSDAY
NIGHT. BEST CHANCES APPEAR TO BE FROM THE EASTERN MOUNTAINS AND
EASTWARD ASSOCIATED WITH THE MORE MOISTURE UPSLOPE FLOW. FRIDAY
HAS THE POTENTIAL TO BE A CHILLY AND CLOUDY DAY ON THE PLAINS AND
EASTERN MOUNTAINS. EXTENDED PROCEDURE GAVE HIGHS IN THE 50S OVER
THE PLAINS FRIDAY...WITH LOW CLOUDS LINGERING UNTIL AT LEAST MID
AFTERNOON. DEPENDING ON THE SPEED OF THE SYSTEM AND THE AMOUNT OF
CLOUDINESS...HIGH TEMPERATURES COULD EVEN BE COOLER. LOW LEVEL
COLD AIR MASS WILL MOSTLY STAY EAST ALONG AND EAST OF THE
EASTERN MOUNTAINS. WITH WARMING AND DRYING ALOFT...IT COULD BE A
SUNNY AND MILD DAY OVER THE REMAINING MOUNTAINS AND HIGH VALLEYS.
.SATURDAY THROUGH MONDAY...WILL HAVE TO WATCH FOR THE POTENTIAL
OF SOME FROST SATURDAY MORNING...DEPENDING ON THE AMOUNT OF
CLEARING. AFTERWARDS...A WARMING TREND WILL DEVELOP FOR THE
WEEKEND ESPECIALLY OVER THE PLAINS AND EASTERN MOUNTAINS AS THE
SURFACE HIGH MOVES EAST OF THE REGION. SOME MONSOON MOISTURE COULD
MOVE INTO THE MOUNTAINS OVER THE WEEKEND...AND INCREASED POPS
SLIGHTLY. OVER THE PLAINS...LOW LEVEL MOISTURE WILL RETURN ON
SUNDAY AND MONDAY...AND THE INCREASED MOISTURE COULD RESULT IN A
FEW AFTERNOON AND EVENING STORMS. --PGW--
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 340 PM MDT MON SEP 8 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO INCREASE ACROSS THE
REGION TONIGHT...PARTICULARLY ALONG THE CONTINENTAL DIVIDE WHERE
WIDESPREAD MTN OBSCURATIONS WILL DEVELOP AFTER MIDNIGHT.
KALS...KCOS...AND KPUB WILL CONTINUE TO SEE VFR CIGS AT TIMES WITH
SHOWERS AND THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON IN THE VCNTY
OF THE AIRPORTS...THEN AGAIN TOWARDS TUESDAY MORNING AS A
DISTURBANCE MOVES ACROSS THE REGION. SOME CLEARING WILL TAKE PLACE
DURING THE LATE MORNING AND EARLY AFTERNOON BEFORE ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS ROLLS OFF THE MOUNTAINS DURING THE
AFTERNOON. THESE TOO MAY PRODUCE VFR TO LOCAL MVFR CIGS/VIS AS THEY
MOVE ACROSS THE REGION. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TUESDAY AFTERNOON FOR COZ067-068.
&&
$$
SHORT TERM...KT
LONG TERM...PGW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1057 AM MDT MON SEP 8 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 411 AM MDT MON SEP 8 2014
MODEL DATA CONTINUES TO SHOW EXCELLENT CONTINUITY REGARDING THE
INTERACTION OF UPPER TROUGH ALONG THE CALIFORNIA COAST AND
MOISTURE PLUME (WHICH INCLUDES THE REMAINS OF NORBERT). MOISTURE
PLUME ARCS FROM THE LOWER COLORADO RIVER BASIN INTO SW UTAH...
EVENTUALLY SPREADING EAST INTO WRN COLORADO AS THE DAY PROGRESSES
TODAY. IN THE SHORT TERM OUTLOOK...THE HRRR SHOWS THE AREA OF PCPN
OVER PARTS OF SW COLORADO (OR WRN PORTION OF THE SAN JUAN
MOUNTAINS) WILL SHIFT NORTHWARD EARLY THIS MORNING AND BE
POSITIONED OVER THE I70 CORRIDOR AROUND DAYBREAK. HAVE NOT SEEN
THIS NORTHWARD TREND YET...BUT SEEMS REASONABLE AS ISENTROPIC
UPGLIDE AND INCREASING MOISTURE FROM THE WEST ACCOUNTS FOR AN
INCREASING CHANCE OF RAIN. SPECIFIC HUMIDITIES AT 700 MB IS QUITE
HIGH WITH VALUES RANGING FROM 8 TO 10 G/KG. PRECIPITABLE WATER AT
KGJT IS PROGGED TO BE 1.25 INCHES BY 00Z THIS EVENING (PER RAP13)...
WHICH IS PLUS 3 STANDARD DEVIATIONS ABOVE NORMAL. USED THE DAY 1
EXCESSIVE RAINFALL OUTLOOK TO FINE TUNE THE FLASH FLOOD WATCH.
THE ONLY AREAS OUTSIDE THE EXCESSIVE RAINFALL IS PARTS OF NE
UTAH...WRN MOFFAT COUNTY AND ARCHULETA COUNTY AND THE ERN EDGE OF
OUR FORECAST AREA.
TONIGHT DEEP MOISTURE CONTINUES TO ADVECT IN FROM THE SW UP TO 1.3
INCHES IN SE UTAH AND EVEN UP TO 1.6 INCHES IN THE 00Z NAM12. THIS
IS VERY HIGH FOR EARLY SEPTEMBER...GREATER THAN TWO STANDARD
DEVIATIONS ABOVE NORMAL. THE SATURATED VERTICAL PROFILE WITH WET
BULB ZERO/ICE PRODUCTION LEVEL AROUND 10KFT WILL NOT NEED DEEP
CONVECTIVE CELLS TO PRODUCE HEAVY RAINFALL. SO THIS WILL MAKE THE
RADAR OBSERVATIONS DIFFICULT TO CAPTURE SOME OF THE HEAVIEST
SHOWERS OCCURRING IN THE FOUR CORNERS REGION. STORM MOTION WILL BE
QUICK THOUGH TO THE ENE AT 20KTS INCREASING TO 30 KTS BY EARLY
TUESDAY MORNING. SOME SHOWERS WILL BE MIXING THESE WINDS DOWN TO
THE SURFACE. THIS IS NOT CAPTURED WELL IN MOS GUIDANCE.
TUESDAY THE BROAD TROUGH WORKS THROUGH THE GREAT BASIN AND INTO
THIS CWA BY LATE AFTERNOON. GRADIENT WINDS VEERS FROM SW TO W AND
INCREASE TO 30 TO 50 KTS IN THE 0-6KM LAYER. THIS WEST FLOW WILL
BEGIN TO ERODE MOISTURE IN THE MID LEVELS ADDING TO AFTERNOON
INSTABILITY. PRECIP WATER VALUES FALL BELOW ONE INCH IN THE
AFTERNOON. JET SUPPORT PASSES THROUGH WYOMING BUT POTENTIAL VORT
FIELDS SHOW SOME FORCING ACROSS THE NORTH. SO CHANCES FOR STRONGER
CONVECTIVE CELLS INCREASE TUESDAY AFTERNOON ESPECIALLY OVER THE
NORTH. GUSTY WINDS AND SMALL HAIL ARE POSSIBLE. HEAVIER RAIN
SHOWERS PERSIST IN THE SOUTH. EXPECT A COOL DAY UNDER WIDESPREAD
CLOUDS AND SHOWERS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 411 AM MDT MON SEP 8 2014
TUESDAY NIGHT...WITH TROUGH PASSAGE OVERNIGHT THE FLOW VEERS TO A
DRIER NW AND PRECIP WATER VALUES DROP TO AROUND 0.5 INCHES FOR ALL
BUT THE SOUTHERN MOST ZONES. SHOWERS ARE EXPECTED TO ERODE FROM
WEST TO EAST THROUGH THE EVENING. THERE MAY BE SOME THREAT OF
LOCALIZED MORNING FOG.
WEDNESDAY-WEDNESDAY NIGHT...A FEW AFTERNOON SHOWERS MAY FORM IN
THE EASTERN MOUNTAINS WEDNESDAY AFTERNOON IN RESIDUAL MOISTURE.
OTHERWISE PLENTY OF SUN RETURNS TO THE FORECAST AREA. TEMPERATURES
REMAIN BELOW NORMAL. LIGHT WINDS AND CLEARING SKIES WEDNESDAY
NIGHT SHOULD ALLOW FOR MODERATE TO STRONG SURFACE BASED INVERSIONS
AND COOL OVERNIGHT LOW TEMPERATURES.
THURSDAY THROUGH SUNDAY...DRY AND STABLE NORTHWEST FLOW IS
EXPECTED TO PREVAIL THROUGH THIS PERIOD. RIDGE AXIS AMPLIFIES OVER
THE WRN STATES WITH TIME. AFTERNOON TEMPS WILL HAVE RECOVERED FROM
THE RAIN COOLED AIR MASS WITH PLENTY OF DAYTIME SUNSHINE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1055 AM MDT MON SEP 8 2014
MOISTURE CONTINUES TO STREAM INTO EASTERN UTAH AND WESTERN
COLORADO THIS MORNING. LIFT HAS BEEN UNFOCUSED WITH MAINLY
ISOLATED TO SCATTERED SHOWERS DRIFTING THROUGH WITH MINIMAL
IMPACTS TO FORECAST TERMINALS. HEATING OF THE DAY WILL HELP BOOST
CONVECTION THIS AFTERNOON AND THE SHOWERS AND THUNDERSTORMS WILL
BECOME MORE WIDESPREAD. OVERALL LIFT INCREASES OVERNIGHT INTO
TUESDAY LEAVING NUMEROUS SHOWERS AND THUNDERSTORMS IN PLACE ACROSS
THE REGION. THEREFOR TERMINAL FORECASTS WILL BE OPTIMISTIC IN THE
FIRST 6 TO 12 HOURS...THEN BECOME INCREASING PESSIMISTIC WITH
BETTER CHANCES OF IFR/MVFR CONDITIONS. OBSCURATION OF THE
HIGHER TERRAIN WILL ALSO BECOME WIDESPREAD THIS AFTERNOON THROUGH
TOMORROW EVENING BEFORE DRYING MOVES IN BEHIND THIS SYSTEM.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR COZ002>014-017>022.
UT...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR UTZ022-025-027>029.
&&
$$
SHORT TERM...PF/JOE
LONG TERM...JOE/PF
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
517 AM MDT MON SEP 8 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 411 AM MDT MON SEP 8 2014
MODEL DATA CONTINUES TO SHOW EXCELLENT CONTINUITY REGARDING THE
INTERACTION OF UPPER TROUGH ALONG THE CALIFORNIA COAST AND
MOISTURE PLUME (WHICH INCLUDES THE REMAINS OF NORBERT). MOISTURE
PLUME ARCS FROM THE LOWER COLORADO RIVER BASIN INTO SW UTAH...
EVENTUALLY SPREADING EAST INTO WRN COLORADO AS THE DAY PROGRESSES
TODAY. IN THE SHORT TERM OUTLOOK...THE HRRR SHOWS THE AREA OF PCPN
OVER PARTS OF SW COLORADO (OR WRN PORTION OF THE SAN JUAN
MOUNTAINS) WILL SHIFT NORTHWARD EARLY THIS MORNING AND BE
POSITIONED OVER THE I70 CORRIDOR AROUND DAYBREAK. HAVE NOT SEEN
THIS NORTHWARD TREND YET...BUT SEEMS REASONABLE AS ISENTROPIC
UPGLIDE AND INCREASING MOISTURE FROM THE WEST ACCOUNTS FOR AN
INCREASING CHANCE OF RAIN. SPECIFIC HUMIDITIES AT 700 MB IS QUITE
HIGH WITH VALUES RANGING FROM 8 TO 10 G/KG. PRECIPITABLE WATER AT
KGJT IS PROGGED TO BE 1.25 INCHES BY 00Z THIS EVENING (PER RAP13)...
WHICH IS PLUS 3 STANDARD DEVIATIONS ABOVE NORMAL. USED THE DAY 1
EXCESSIVE RAINFALL OUTLOOK TO FINE TUNE THE FLASH FLOOD WATCH.
THE ONLY AREAS OUTSIDE THE EXCESSIVE RAINFALL IS PARTS OF NE
UTAH...WRN MOFFAT COUNTY AND ARCHULETA COUNTY AND THE ERN EDGE OF
OUR FORECAST AREA.
TONIGHT DEEP MOISTURE CONTINUES TO ADVECT IN FROM THE SW UP TO 1.3
INCHES IN SE UTAH AND EVEN UP TO 1.6 INCHES IN THE 00Z NAM12. THIS
IS VERY HIGH FOR EARLY SEPTEMBER...GREATER THAN TWO STANDARD
DEVIATIONS ABOVE NORMAL. THE SATURATED VERTICAL PROFILE WITH WET
BULB ZERO/ICE PRODUCTION LEVEL AROUND 10KFT WILL NOT NEED DEEP
CONVECTIVE CELLS TO PRODUCE HEAVY RAINFALL. SO THIS WILL MAKE THE
RADAR OBSERVATIONS DIFFICULT TO CAPTURE SOME OF THE HEAVIEST
SHOWERS OCCURRING IN THE FOUR CORNERS REGION. STORM MOTION WILL BE
QUICK THOUGH TO THE ENE AT 20KTS INCREASING TO 30 KTS BY EARLY
TUESDAY MORNING. SOME SHOWERS WILL BE MIXING THESE WINDS DOWN TO
THE SURFACE. THIS IS NOT CAPTURED WELL IN MOS GUIDANCE.
TUESDAY THE BROAD TROUGH WORKS THROUGH THE GREAT BASIN AND INTO
THIS CWA BY LATE AFTERNOON. GRADIENT WINDS VEERS FROM SW TO W AND
INCREASE TO 30 TO 50 KTS IN THE 0-6KM LAYER. THIS WEST FLOW WILL
BEGIN TO ERODE MOISTURE IN THE MID LEVELS ADDING TO AFTERNOON
INSTABILITY. PRECIP WATER VALUES FALL BELOW ONE INCH IN THE
AFTERNOON. JET SUPPORT PASSES THROUGH WYOMING BUT POTENTIAL VORT
FIELDS SHOW SOME FORCING ACROSS THE NORTH. SO CHANCES FOR STRONGER
CONVECTIVE CELLS INCREASE TUESDAY AFTERNOON ESPECIALLY OVER THE
NORTH. GUSTY WINDS AND SMALL HAIL ARE POSSIBLE. HEAVIER RAIN
SHOWERS PERSIST IN THE SOUTH. EXPECT A COOL DAY UNDER WIDESPREAD
CLOUDS AND SHOWERS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 411 AM MDT MON SEP 8 2014
TUESDAY NIGHT...WITH TROUGH PASSAGE OVERNIGHT THE FLOW VEERS TO A
DRIER NW AND PRECIP WATER VALUES DROP TO AROUND 0.5 INCHES FOR ALL
BUT THE SOUTHERN MOST ZONES. SHOWERS ARE EXPECTED TO ERODE FROM
WEST TO EAST THROUGH THE EVENING. THERE MAY BE SOME THREAT OF
LOCALIZED MORNING FOG.
WEDNESDAY-WEDNESDAY NIGHT...A FEW AFTERNOON SHOWERS MAY FORM IN
THE EASTERN MOUNTAINS WEDNESDAY AFTERNOON IN RESIDUAL MOISTURE.
OTHERWISE PLENTY OF SUN RETURNS TO THE FORECAST AREA. TEMPERATURES
REMAIN BELOW NORMAL. LIGHT WINDS AND CLEARING SKIES WEDNESDAY
NIGHT SHOULD ALLOW FOR MODERATE TO STRONG SURFACE BASED INVERSIONS
AND COOL OVERNIGHT LOW TEMPERATURES.
THURSDAY THROUGH SUNDAY...DRY AND STABLE NORTHWEST FLOW IS
EXPECTED TO PREVAIL THROUGH THIS PERIOD. RIDGE AXIS AMPLIFIES OVER
THE WRN STATES WITH TIME. AFTERNOON TEMPS WILL HAVE RECOVERED FROM
THE RAIN COOLDED AIR MASS WITH PLENTY OF DAYTIME SUNSHINE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 517 AM MDT MON SEP 8 2014
DETERIORATING CONDITIONS TODAY AS SCATTERED -SHRA/-TSRA WILL
EXPAND IN AREAL COVERAL TODAY AND BECOME NUMEROUS THIS AFTERNOON.
FREQUEST -SHRA WITH EMBEDDED -TSRA IS EXPECTED TONIGHT WITH LOCAL
4SM +SHRA POSSIBLE. CIGS/VIS MAY LOWER TO IFR/MVFR FROM THE
STRONGEST SHOWERS OR THUNDERSTORMS...ESPECIALLY AT MOUNTAIN TAF
SITES.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH FROM 9 AM MDT THIS MORNING THROUGH TUESDAY
EVENING FOR COZ002>014-017>022.
UT...FLASH FLOOD WATCH FROM 9 AM MDT THIS MORNING THROUGH TUESDAY
EVENING FOR UTZ022-025-027>029.
&&
$$
SHORT TERM...PF/JOE
LONG TERM...JOE/PF
AVIATION...PF
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
411 AM MDT MON SEP 8 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 411 AM MDT MON SEP 8 2014
MODEL DATA CONTINUES TO SHOW EXCELLENT CONTINUITY REGARDING THE
INTERACTION OF UPPER TROUGH ALONG THE CALIFORNIA COAST AND
MOISTURE PLUME (WHICH INCLUDES THE REMAINS OF NORBERT). MOISTURE
PLUME ARCS FROM THE LOWER COLORADO RIVER BASIN INTO SW UTAH...
EVENTUALLY SPREADING EAST INTO WRN COLORADO AS THE DAY PROGRESSES
TODAY. IN THE SHORT TERM OUTLOOK...THE HRRR SHOWS THE AREA OF PCPN
OVER PARTS OF SW COLORADO (OR WRN PORTION OF THE SAN JUAN
MOUNTAINS) WILL SHIFT NORTHWARD EARLY THIS MORNING AND BE
POSITIONED OVER THE I70 CORRIDOR AROUND DAYBREAK. HAVE NOT SEEN
THIS NORTHWARD TREND YET...BUT SEEMS REASONABLE AS ISENTROPIC
UPGLIDE AND INCREASING MOISTURE FROM THE WEST ACCOUNTS FOR AN
INCREASING CHANCE OF RAIN. SPECIFIC HUMIDITIES AT 700 MB IS QUITE
HIGH WITH VALUES RANGING FROM 8 TO 10 G/KG. PRECIPITABLE WATER AT
KGJT IS PROGGED TO BE 1.25 INCHES BY 00Z THIS EVENING (PER RAP13)...
WHICH IS PLUS 3 STANDARD DEVIATIONS ABOVE NORMAL. USED THE DAY 1
EXCESSIVE RAINFALL OUTLOOK TO FINE TUNE THE FLASH FLOOD WATCH.
THE ONLY AREAS OUTSIDE THE EXCESSIVE RAINFALL IS PARTS OF NE
UTAH...WRN MOFFAT COUNTY AND ARCHULETA COUNTY AND THE ERN EDGE OF
OUR FORECAST AREA.
TONIGHT DEEP MOISTURE CONTINUES TO ADVECT IN FROM THE SW UP TO 1.3
INCHES IN SE UTAH AND EVEN UP TO 1.6 INCHES IN THE 00Z NAM12. THIS
IS VERY HIGH FOR EARLY SEPTEMBER...GREATER THAN TWO STANDARD
DEVIATIONS ABOVE NORMAL. THE SATURATED VERTICAL PROFILE WITH WET
BULB ZERO/ICE PRODUCTION LEVEL AROUND 10KFT WILL NOT NEED DEEP
CONVECTIVE CELLS TO PRODUCE HEAVY RAINFALL. SO THIS WILL MAKE THE
RADAR OBSERVATIONS DIFFICULT TO CAPTURE SOME OF THE HEAVIEST
SHOWERS OCCURRING IN THE FOUR CORNERS REGION. STORM MOTION WILL BE
QUICK THOUGH TO THE ENE AT 20KTS INCREASING TO 30 KTS BY EARLY
TUESDAY MORNING. SOME SHOWERS WILL BE MIXING THESE WINDS DOWN TO
THE SURFACE. THIS IS NOT CAPTURED WELL IN MOS GUIDANCE.
TUESDAY THE BROAD TROUGH WORKS THROUGH THE GREAT BASIN AND INTO
THIS CWA BY LATE AFTERNOON. GRADIENT WINDS VEERS FROM SW TO W AND
INCREASE TO 30 TO 50 KTS IN THE 0-6KM LAYER. THIS WEST FLOW WILL
BEGIN TO ERODE MOISTURE IN THE MID LEVELS ADDING TO AFTERNOON
INSTABILITY. PRECIP WATER VALUES FALL BELOW ONE INCH IN THE
AFTERNOON. JET SUPPORT PASSES THROUGH WYOMING BUT POTENTIAL VORT
FIELDS SHOW SOME FORCING ACROSS THE NORTH. SO CHANCES FOR STRONGER
CONVECTIVE CELLS INCREASE TUESDAY AFTERNOON ESPECIALLY OVER THE
NORTH. GUSTY WINDS AND SMALL HAIL ARE POSSIBLE. HEAVIER RAIN
SHOWERS PERSIST IN THE SOUTH. EXPECT A COOL DAY UNDER WIDESPREAD
CLOUDS AND SHOWERS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 411 AM MDT MON SEP 8 2014
TUESDAY NIGHT...WITH TROUGH PASSAGE OVERNIGHT THE FLOW VEERS TO A
DRIER NW AND PRECIP WATER VALUES DROP TO AROUND 0.5 INCHES FOR ALL
BUT THE SOUTHERN MOST ZONES. SHOWERS ARE EXPECTED TO ERODE FROM
WEST TO EAST THROUGH THE EVENING. THERE MAY BE SOME THREAT OF
LOCALIZED MORNING FOG.
WEDNESDAY-WEDNESDAY NIGHT...A FEW AFTERNOON SHOWERS MAY FORM IN
THE EASTERN MOUNTAINS WEDNESDAY AFTERNOON IN RESIDUAL MOISTURE.
OTHERWISE PLENTY OF SUN RETURNS TO THE FORECAST AREA. TEMPERATURES
REMAIN BELOW NORMAL. LIGHT WINDS AND CLEARING SKIES WEDNESDAY
NIGHT SHOULD ALLOW FOR MODERATE TO STRONG SURFACE BASED INVERSIONS
AND COOL OVERNIGHT LOW TEMPERATURES.
THURSDAY THROUGH SUNDAY...DRY AND STABLE NORTHWEST FLOW IS
EXPECTED TO PREVAIL THROUGH THIS PERIOD. RIDGE AXIS AMPLIFIES OVER
THE WRN STATES WITH TIME. AFTERNOON TEMPS WILL HAVE RECOVERED FROM
THE RAIN COOLDED AIR MASS WITH PLENTY OF DAYTIME SUNSHINE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 102 4 PM MDT SUN SEP 7 2014
AN AREA OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES TO DRIFT
SLOWLY EAST FROM ABAJO MOUNTAINS THROUGH MOST OF SOUTHWESTERN
COLORADO. THIS AREA OF SHOWERS WILL DIMINISH AFTER MIDNIGHT. AN
ISOLATED SHOWER/THUNDERSTORM WILL STILL BE POSSIBLE INTO THE
MORNING HOURS ON MONDAY. AS MOISTURE INCREASES FROM THE SOUTH ON
MONDAY THE THREAT OF SHOWERS AND THUNDERSTORMS WILL PUSH INTO THE
SCATTERED CATEGORIES BY MONDAY AFTERNOON WITH MORE WIDESPREAD
COVERAGE BY MONDAY NIGHT. AT THE ONSET...GUSTY OUTFLOW WINDS TO 45
MPH WILL BE POSSIBLE. LOCALLY HEAVY RAIN WILL RESULT IN SCT MVFR
CONDITIONS WITH ISOLATED IFR WHICH WILL CONTINUE AND INCREASE IN
COVERAGE BY MONDAY NIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH FROM 9 AM MDT THIS MORNING THROUGH TUESDAY
EVENING FOR COZ002>014-017>022.
UT...FLASH FLOOD WATCH FROM 9 AM MDT THIS MORNING THROUGH TUESDAY
EVENING FOR UTZ022-025-027>029.
&&
$$
SHORT TERM...PF/JOE
LONG TERM...JOE/PF
AVIATION...MPM
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
930 PM EDT TUE SEP 9 2014
.SYNOPSIS...
AN ONSHORE FLOW PRODUCED BY THE COMBINED EFFECTS OF HIGH PRESSURE
EAST OF THE CANADIAN MARITIMES AND LOW PRESSURE OFF THE MID ATLANTIC
COAST WILL GRADUALLY WEAKEN ON WEDNESDAY AS BOTH SYSTEMS MOVE
FURTHER OFFSHORE. A COLD FRONT WILL MOVE THROUGH THE AREA THURSDAY
NIGHT, THEN STALL TO OUR SOUTH WHILE HIGH PRESSURE BUILDS IN FROM
THE NORTH ON FRIDAY. THE STALLED BOUNDARY COULD WORK ITS WAY BACK
NORTH SATURDAY, THEN OFFSHORE LATE IN THE WEEKEND. HIGH PRESSURE IS
THEN EXPECTED TO BUILD INTO THE MID-ATLANTIC REGION BY MONDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
930 PM UPDATE...NOT TOO MANY CHANGES AS THE TEMPERATURE FORECAST
STILL LOOKS ON TRACK. HOWEVER, GIVEN THE RADAR TRENDS OVER THE
LAST SEVERAL HOURS, DID LOWER THE PRECIP CHANCES, TO ONLY AN
ISOLATED SHOWER MENTION ON THE COASTAL PLAINS.
PREVIOUS NEAR TERM DISCUSSION...A LOW PRESSURE SYSTEM WILL
CONTINUE TO MOVE NORTHEAST OFFSHORE TONIGHT. EXPECT A RATHER
CLOUDY NIGHT ACROSS THE REGION OVERALL WHICH MAY KEEP LOW
TEMPERATURES IN THE 60`S FOR MOST OF THE REGION. COOLER
TEMPERATURES WILL BE OBSERVED NW OF PHL. STAYED CLOSE TO MAV/MET
GUIDANCE WITH TEMPS AND DEWPOINTS. SOME ISOLATED SHOWERS ARE
PRESENT ACROSS THE EASTERN PORTIONS OF THE REGION AND WILL MOVE
FROM EAST TO WEST THROUGH THE REMAINDER OF THE AFTERNOON. SLIGHT
CHANCE POPS IN PLACE, BASICALLY FROM PHL TO THE SE. THE RAP SHOWS
THE POTENTIAL FOR SOME ADDITIONAL SCATTERED SHOWERS TO MOVE CLOSE
TO THE COAST TONIGHT AND A SLIGHT TO LOW CHANCE POP HAS BEEN LEFT
IN THE FORECAST TO ACCOUNT FOR THIS. LIGHT QPF UNDER 1/10TH INCH
IS EXPECTED, WITH RFC FORECAST QPF GUIDANCE USED OVERNIGHT AND THE
EARLY EVENING QPF FORECAST BASED MORE ON THE SREF. CONTINUED
NORTHEAST WINDS TONIGHT PERHAPS A FEW GUSTS EARLY AROUND 20 MPH.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
THE LOW PRESSURE SYSTEM WILL CONTINUE MOVING OFFSHORE ON
WEDNESDAY. THIS WILL ALLOW CLOUDS TO GRADUALLY CLEAR BY THE END OF
THE DAY AND ANY REMAINING POPS ARE BEFORE NOON ALONG THE SHORE. WINDS
WILL SHIFT AROUND TO THE SOUTHEAST AHEAD OF THE NEXT SYSTEM,
GENERALLY UNDER 10 MPH. WITH THE CLOUD COVER HIGH TEMPERATURES MAY BE
HELD DOWN A BIT, SO DID NOT GO THE WARMER MET GUIDANCE. FORECASTED
TEMPERATURES TREND MORE TOWARD THE COOLER MAV GUIDANCE, RIGHT AROUND
80 FOR PHL AND 70`S FOR MOST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS THE COASTAL LOW CONTINUES TO MOVE FURTHER OFFSHORE...WEAK HIGH
PRESSURE WILL BUILD IN WEDNESDAY NIGHT AND THURSDAY AS A COLD FRONT
APPROACHES FROM THE WEST. THE LATEST GFS RUN INDICATES THIS NEXT
COLD FRONT MIGHT ENTER OUR FAR WESTERN ZONES LATE THURSDAY
AFTERNOON...PASSING THROUGH THE REST OF THE CWA DURING THE EVENING
HOURS BEFORE REACHING THE COAST AROUND MIDNIGHT. THIS LATEST RUN
ALSO INDICATES THE FRONT MIGHT STALL A LITTLE FURTHER SOUTH OF OUR
AREA COMPARED TO EARLIER RUNS WHICH COULD TRANSLATE INTO A MOSTLY
PRECIPITATION-FREE WEEKEND AS HIGH PRESSURE MOVING THROUGH THE GREAT
LAKES BUILDS OVER THE REGION. THE ECMWF IS NOT AS OPTIMISTIC AND
KEEPS THE FRONT CLOSER TO OUR AREA, ALONG WITH A PROLONGED THREAT OF
SHOWER ACTIVITY FOR THE WEEKEND. IN TERMS OF THE FORECAST
GRIDS...AFTERNOON POPS ON THURSDAY ARE HIGHEST IN THE PA ZONES,
WHERE TIMING OF FROPA WOULD COINCIDE MORE FAVORABLY WITH PEAK
HEATING HOURS. THERE IS SOME DEGREE OF A THREAT FOR HEAVY RAINFALL
IN THUNDERSTORMS, BUT THE THREAT OF MAY BE MORE LOCALIZED THAN
WIDESPREAD. THEN POPS BECOME PROGRESSIVELY HIGHER FROM WEST TO EAST
AS THE FRONT MOVES THROUGH. A BASICALLY RAIN FREE PERIOD IS EXPECTED
LATER FRIDAY INTO EARLY SATURDAY, BUT SHOWERS COULD RETURN ONCE
AGAIN SATURDAY AFTERNOON INTO SUNDAY DEPENDING ON WHERE THE STALLED
FRONT ACTUALLY SETS UP SHOP. POPS THAT WERE ALREADY INTRODUCED INTO
THE GRIDS WERE BASICALLY KEPT IN THIS FCST CYCLE UNTIL MODEL
INFORMATION BECOMES MORE CERTAIN. IMPROVEMENTS ARE EXPECTED EARLY
NEXT WEEK AS HIGH PRESSURE MOVES IN FROM THE NORTHWEST.
IN TERMS OF TEMPERATURES...ABOVE NORMAL EXPECTED UNTIL THE FRONT
MOVES THROUGH THURSDAY NIGHT...THEN NEAR TO SLIGHTLY BELOW NORMAL
AFTER THAT.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
FOR THE 00Z TAFS...EXPECT MVFR CEILINGS TO MOVE IN ACROSS MUCH OF
THE REGION BY 09Z. CEILINGS COULD BE VRB AT TIMES, BUT IN GENERAL
SHOULD BE MVFR FOR MUCH OF THE NIGHT INTO TOMORROW MORNING AS THE
PERSISTENT ON SHORE FLOW CONTINUES. FOR LOCATIONS CLOSER TO THE
COAST, INCLUDING KACY AND KMIV, IFR CEILINGS ARE POSSIBLE MOSTLY
BETWEEN 09 AND 15Z. THERE IS ALSO A CHANCE FOR LOWER VISIBILITIES
OVERNIGHT AS THE LOW LEVELS WILL BE NEARLY SATURATED IN MANY
PLACES. HOWEVER, WINDS SHOULD STAY ABOVE 5KT, AND NEAR 10KT IN
MANY PLACES, THIS SHOULD INHIBIT DENSE FOG DEVELOPMENT.
THUS...ONLY EXPECT VISIBILITIES TO LOWER TO THE 3 TO 5SM RANGE.
CEILINGS SHOULD SLOWLY RISE, AND POSSIBLY DISSIPATE BETWEEN 15 AND
18Z TOMORROW. AS WITH THE OVERNIGHT HOURS, TERMINALS CLOSER TO THE
COAST (KACY AND KMIV) SHOULD SEE THE LOWER CONDITIONS LONGER.
OUTLOOK...
WEDNESDAY NIGHT...VFR IN THE EVE. LOW CLOUDS AND FOG MAY DEVELOP
OVERNIGHT.
THURSDAY AND THURSDAY NIGHT...SHRA AND TSRA LIKELY IN THE AFTN AT
RDG/ABE. THIS ACTIVITY MAY HOLD OFF FARTHER EAST UNTIL THE EVE
WHEN A COLD FRONT MOVES THRU. FROPA WILL BE MARKED BY WIND SHIFT
FROM S TO NW.
FRIDAY AND FRIDAY NIGHT...VFR
SATURDAY AND SUNDAY...CHANCE OF SHRA WITH SUB-VFR CONDITIONS POSSIBLE.
&&
.MARINE...
SEAS ARE CURRENTLY RUNNING WELL OVER FIVE FEET ON THE OCEAN WATERS.
WITH THE CONTINUED ONSHORE FLOW SEAS WILL LIKELY BE OVER FIVE FEET
THROUGH WEDNESDAY. AS A RESULT, THE SMALL CRAFT ADVISORY HAS BEEN
EXTENDED THROUGH WEDNESDAY NIGHT ON THE OCEAN WATERS. WINDS AROUND 20
KNOTS ARE LIKELY WITH THE POTENTIAL FOR SCA CRITERIA GUSTS THROUGH
TONIGHT AND INTO WEDNESDAY MORNING ON THE OCEAN WATERS. FOR DELAWARE
BAY, WINDS HAVE GENERALLY BEEN AT OR UNDER 20 KNOTS AND WITH LOWER
SEAS ONGOING. WE`LL ALLOW THE SCA TO EXPIRE AT 6PM ON THE BAY.
OUTLOOK...
WEDNESDAY NIGHT...THE PRESSURE GRADIENT GRADUALLY WEAKENS AND
WINDS SHOULD DECREASE TO BELOW SCA LEVELS BY THE AFTN. HOWEVER,
THE SCA MAY STILL BE NEEDED AS SEAS WILL TAKE TIME TO SUBSIDE. THE
LATEST GUIDANCE SUGGESTS WAVES OF 4-5 FT FOR THIS PERIOD.
THURSDAY...SOUTHERLY WINDS INCREASE AHEAD OF A FRONT BUT SHOULD
REMAIN BELOW SCA LVLS.
THURSDAY NIGHT AND FRIDAY MORNING...COLD FRONT MOVES THRU THE WATERS
THURSDAY NIGHT. STORMS MAY PRODUCE LOCALLY GUSTY WINDS JUST AHEAD OF
THE FRONT DURING THE EVE. PRESSURE SURGE IN WAKE OF FROPA MAY
PRODUCE A BRIEF PERIOD OF NW WINDS GUSTING TO NEAR SCA THRESHOLD
LATE THURSDAY NIGHT INTO FRIDAY MORNING.
FRIDAY AFTERNOON THROUGH SUNDAY....NO MARINE HEADLINES ARE
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WITH A COASTAL LOW MEANDERING JUST OFFSHORE AND ONSHORE FLOW
CONTINUING, THE THREAT OF MINOR COASTAL FLOODING IS EXPECTED TO
CONTINUE INTO AT LEAST WEDNESDAY MORNING`S HIGH TIDE CYCLE.
MINOR TIDAL FLOODING IS ALREADY OCCURRING ON THE OCEAN FRONT NOW
AND SHOULD BEGIN ON THE LOWER DELAWARE BAY SOON. GOING INTO
WEDNESDAY MORNING AND MIDDAY, THE PRESSURE GRADIENT ALONG THE
COAST LOOKS TO TIGHTEN SOMEWHAT, AND THE WINDS ARE FORECAST TO
BECOME A LITTLE MORE NORTHEASTERLY. WE THEREFORE HAVE EXTENDED THE
CURRENT COASTAL FLOOD ADVISORY THROUGH THE WEDNESDAY MORNING TO
MIDDAY HIGH TIDE CYCLE.
&&
.RIP CURRENTS...
THE THREAT FOR RIP CURRENTS ON WEDNESDAY IS EXPECTED TO BE AT
LEAST MODERATE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR NJZ012>014-
020-022>027.
COASTAL FLOOD ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR NJZ016-021.
DE...COASTAL FLOOD ADVISORY UNTIL 2 PM EDT WEDNESDAY FOR DEZ003-004.
COASTAL FLOOD ADVISORY UNTIL 4 PM EDT WEDNESDAY FOR DEZ001-002.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT WEDNESDAY NIGHT FOR
ANZ450>455.
&&
$$
SYNOPSIS...MIKETTA
NEAR TERM...GAINES/JOHNSON/NIERENBERG
SHORT TERM...GAINES/NIERENBERG
LONG TERM...MIKETTA
AVIATION...JOHNSON/MIKETTA
MARINE...GAINES/NIERENBERG/MIKETTA
TIDES/COASTAL FLOODING...KLINE/JOHNSON
RIP CURRENTS...JOHNSON
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
917 AM EDT MON SEP 8 2014
.SYNOPSIS...
HIGH PRESSURE OVER NEW ENGLAND WILL STRENGTHEN AS IT MOVES TO THE
MARITIMES TONIGHT. MEANWHILE LOW PRESSURE WILL BE MOVING SLOWLY
NORTHEAST FROM THE COASTAL CAROLINAS AND PASSING OUT TO SEA EAST OF
THE MID ATLANTIC COAST WEDNESDAY NIGHT OR THURSDAY. A COLD FRONT
WILL CROSS OUR AREA FROM THE NORTHWEST LATE THURSDAY OR FRIDAY.
STRONG HIGH PRESSURE OVER THE PLAINS STATES FRIDAY BUILDS INTO THE
NORTHEAST FOR THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON LATEST RADAR AND HRRR GUID HAVE REMOVED POPS ACRS THE LWR
DELMARVA IN THE REAL NEAR TERM AND LOWERED POPS A TAD LATER TODAY.
WILL SEE HOW THINGS DEVELOP FOR THE LATE MRNG UPDATE. OTHERWISE,
ADJUSTED CLOUD COVER DOWNWARD UP NORTH, WHERE STLT IMAGERY SHOWED
IT WAS CLEAR.
WEAK LOW PRESSURE DEVELOPING OFF THE SE US COAST TODAY AND
PERSISTENT HIGH PRESSURE ACROSS ERN NEW ENGLAND AND SE CANADA WILL
KEEP A ONSHORE FLOW DIRECTED ACROSS OUR AREA TODAY. HIGH/MID LEVEL
CLOUDINESS ALREADY EXISTS ACROSS THE S/E HALF OF THE AREA...AND IT
WILL CONTINUE TO LOWER/THICKEN TODAY. WITH REGARDS TO PCPN
POTENTIAL...WE HAVE SIDED A BIT CLOSER TO THE GFS WHICH BRINGS SOME
SMALL CHC FOR SHOWERS TO THE DELMARVA LATER TODAY...OVERALL OUR POPS
ARE A BIT LESS THAN THE PREVIOUS FCST. THE 00Z EC HAS SOME LIGHTER
SHOWERS DEVELOPING FURTHER NORTH AND EARLIER THAN THE GFS...BUT THIS
DOES NOT LOOK RIGHT...SO WE WILL KEEP THE IDEAS FROM THE THE EARLIER
FCST...JUST SLOWED DOWN A BIT. TEMPS...MOSTLY MAV BUT BLENDED IN
WITH EARLIER FCST TOO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
MUCH LIKE THE NEAR TERM...HIGHER PCPN CHC ESPECIALLY S/E WHERE
LIKELY/LOW CATEGORICAL POPS ARE EXPECTED...NO PCPN EXPECTED N/W.
WEAK LOW WILL SLIDE A BIT UP THE COAST AND KEEP THE ONSHORE FLOW
ACROSS THE AREA...CLOUDS ARE EXPECTED ACROSS MOST ALL AREAS...LESS
N/W. WINDS MOSTLY ERLY AROUND 10 KTS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AN AMENDED-CORRECTED SET OF ZONES WAS SENT AT 510AM TO MORE
ACCURATELY ACCOUNT FOR THE GRIDDED 330 AM FORECAST EXPECTATIONS
BETWEEN TUESDAY AND SATURDAY.
500 MB: A SLOW MOVING TROUGH MOVES EAST ACROSS THE MID ATLANTIC
STATES TUESDAY AND WEDNESDAY. THEREAFTER...TWO STRONG SHORT WAVES
MOVE THROUGH THE UPPER MIDWEST FROM LATE THURSDAY THROUGH NEXT
SUNDAY.
TEMPERATURES: THE FIRST WEEK OF SEPTEMBER HAS AVERAGED WELL ABOVE
NORMAL...ON THE ORDER OF ABOUT 6 DEGREES. NEAR NORMAL TEMPERATURES
TUESDAY SHOULD WARM TO MORE THAN 5 DEGREES ABOVE NORMAL THURSDAY
THEN COOL TO SLIGHTLY BELOW NORMAL OVER THE WEEKEND.
FORECAST BASIS: UNLESS OTHERWISE NOTED THE LONG TERM PERIOD OF THIS
FORECAST IS GENERALLY BASED ON A 50 50 BLEND OF THE 00Z/8 NAM/GFS
MOS FOR THE PERIOD TUESDAY - WEDNESDAY...THE 00Z/8 GFS MOS WEDNESDAY
NIGHT AND THURSDAY...THEN THEREAFTER (THURSDAY NIGHT ONWARD) THE
0443Z/8 WPC GRIDDED GUIDANCE WHICH AT TIMES IS BLENDED 50 50 WITH
THE 00Z/8 MEXMOS. ALL THIS IS EVENTUALLY CHECKED AGAINST THE
00Z/8 ECMWF TO SEE IF WE`RE IN THE BALLPARK WITH ECMWF CYCLICALLY
PERSISTENT 18Z 2 METER TEMPERATURES. THE PRECIPITATION PROBABILITY
GUIDANCE IS CHECKED AGAINST THE 21Z/7 SREF 3HRLY POPS FOR .01
THROUGH 12Z THURSDAY AND THEREAFTER THE 00Z/8 GEFS 6HR POPS FOR
0.05
THE DAILIES BELOW...
TUESDAY INTO WEDNESDAY...IT MAY BE NASTY AT TIMES ALONG THE DE COAST
AND THE S NJ COAST WITH GUSTY EAST NORTHEAST WINDS AND BANDS OF
SHOWERS SWEEPING NWWD INLAND IN A TROWAL ENVIRONMENT. POTENTIAL 6
TO 8 FOOT SURF ALONG PORTIONS OF THE COAST. THERE IS STILL
UNCERTAINTY AS TO HOW MUCH RAIN WILL ACCUMULATE IN OUR AREA.
THERE IS A GOOD CHANCE THE REGION NORTH OF INTERSTATE 78 (NE PA
AND NW NJ) RECEIVES ONLY A TRACE OF SPRINKLES OR NO RAIN AT ALL
WHILE AMOUNTS SOMEWHERE IN SOUTHERN DELAWARE MIGHT BE QUITE
SUBSTANTIAL. HIGH TEMPERATURES WILL BE DEPENDENT ON DURATION OF
ANY RAIN DURING THE MIDDAY AND AFTN HOURS WITH WET BULBING
POSSIBLY MEANING HIGHS ONLY NEAR 70. ISOLATED THUNDER MAY OCCUR
IN DE AND COASTAL S NJ.
LATER WEDNESDAY INTO THURSDAY...A DISTINCTLY RAINFREE PERIOD AS THE
COASTAL LOW TURNS EAST OUT TO SEA AND A COLD FRONT WITH WARM AIR
ADVECTION AHEAD OF IT AND THEN EVENTUALLY A SLIVER OF INSTABILITY
ALONG IT ARRIVES FOR THURSDAY NIGHT. SO A VERY NICE WARMUP IS
ANTICIPATED FOR THURSDAY (15-16C AT 850MB) AND THIS SHOULD BE THE
WARMEST DAY OF THE WORK WEEK...MID 80S ANTICIPATED. SHOWERS AND
THUNDERSTORMS MAY OCCUR VERY LATE IN THE DAY OR AT NIGHT.
WHAT HAPPENS FRIDAY INTO EARLY SATURDAY IS HIGHLY UNCERTAIN AS
MODELS...ESPECIALLY THE ECMWF HAVE BEEN FLIP FLOPPING. IT APPEARS
THAT THERE IS A POSSIBLE STALLING OR SLOWING OF THE COLD FRONTAL
PASSAGE SO THAT SHOWERS NEED TO REMAIN IN THE FORECAST. VERY LOW
CONFIDENCE ON WHAT WILL OCCUR FOR THIS TIME FRAME OF THE FORECAST.
THE OP EC IS AT ODDS WITH THE GEFS.
LATER SATURDAY AND SUNDAY...HIGH PRESSURE IS EXPECTED TO FOLLOW THE
COLD FRONTS SEAWARD PASSAGE. IT WILL BE A TYPICAL EARLY AUTUMN AIR
MASS...SEASONABLY COOLER...WITH HIGHS MAINLY IN THE 70S AND LOWS MOSTLY
IN THE 50S.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THERE WERE NOT MANY CHANGES IN THE 06Z TAFS...COMPARED TO THE 00Z
TAFS. THE TRENDS IN THE OPERATIONAL MODELS REMAIN ABOUT THE SAME.
HIGH/MID LEVEL CLOUDINESS INCREASE OVER THE AREA...FOLLOWED BY
LOWER CLOUDS LATER THIS AFTERNOON AND TONIGHT...ESPECIALLY
SOUTH/EAST. WE HAVE VFR CONDITIONS IN THE TERMINALS EVERYWHERE
THRU 06Z TUE...WITH SOME MVFR FOR THE 30 HT PHL TAF COVERING THE
06Z-12Z TUE PERIOD. WINDS WILL INCREASE FROM THE NE/E TODAY AND
REMAIN AROUND 10 KNOTS TONIGHT. CLOSER TO THE COAST WINDS WILL BE
5 TO 10 KTS HIGHER WITH SOME GUSTINESS POSSIBLE.
OUTLOOK...
TUESDAY...VFR CIGS OCNLLY MVFR CONDITIONS IN SCATTERED SHOWERS.
BRIEF IFR CONDS POSSIBLE VCNTY KMIV AND KACY IN HEAVIER SHOWERS.
EAST TO NORTHEAST GUSTS 18-28 KT. CONFIDENCE: AVERAGE
WEDNESDAY...MAINLY VFR WITH ANY LINGERING SHOWERS TENDING TO END
FROM WEST TO EAST. CONFIDENCE: AVERAGE.
WEDNESDAY NIGHT AND THURSDAY...VFR EXCEPT FOR LATE NIGHT AND EARLY
MORNING LOW CLOUDS AND FOG. THERE IS ALSO A CHANCE OF AFTERNOON
SHOWERS AND THUNDERSTORMS WITH MVFR AND IFR CONDITIONS POSSIBLE AT
TIMES. CONFIDENCE: AVERAGE.
THURSDAY NIGHT...A CHANCE OF SHOWERS AND THUNDERSTORMS WITH MVFR AND
IFR CONDITIONS POSSIBLE AT TIMES. CONFIDENCE: AVERAGE.
FRIDAY...MAINLY VFR BUT CONFIDENCE IS WELL BELOW AVERAGE SINCE A MVFR
OR EVEN IFR CONDITION SCENARIO COULD DEVELOP IF THE PROJECTED COLD
FRONTAL PASSAGE STALLS IN OUR AREA FOR 12 HOURS.
&&
.MARINE...
WE WILL CONTINUE WITH SCA FLAGS FOR THE WATERS TODAY...WE WILL DELAY
THE ONSET TIME A FEW HOURS THAN EARLIER SET. WINDS/SEAS EXPECTED TO
SLOWLY INCREASE TODAY AND SEAS ON THE OCEAN SHOULD BUILD TO 5 TO 7
FT BY TONIGHT. SCA CONDITIONS LOOK TO PERSIST SEVERAL PERIODS.
OUTLOOK...
TUESDAY...A SMALL CRAFT ADVISORY IS IN EFFECT FOR A BRISK
EAST-NORTHEASTERLY FLOW AND SEAS ABOVE 5 FT.
TUESDAY NIGHT AND WEDNESDAY...SMALL CRAFT ADVISORY CONDITIONS ARE
EXPECTED TO CONTINUE, ESPECIALLY ON OUR OCEAN WATERS. WE DID NOT
EXTEND THE ADVISORY AT THIS TIME SINCE WE FIRST WANT TO BE SURE WE
REACH ADVISORY CONDITION TODAY.
WEDNESDAY NIGHT...WIND SPEEDS ARE FORECAST TO FALL BELOW THE
SMALL CRAFT ADVISORY CRITERION. HOWEVER, WAVES ON OUR OCEAN WATERS
MAY REMAIN AROUND 5 FEET.
THURSDAY THROUGH FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED
ALTHOUGH THERE MAY BE A SHORT WINDOW OF SMALL CRAFT ADVISORY
CONDITIONS FRIDAY?
&&
.TIDES/COASTAL FLOODING...
THE ONSHORE FLOW WILL INCREASE TODAY AND REMAIN IN PLACE THE NEXT
SEVERAL DAYS. TIDAL DEPARTURES WILL INCREASE...BUT THE DEGREE OF
DEPARTURE REMAINS UNCERTAIN. THE HIGHER OF THE TOW TIDES THIS EVENING
WILL PROBABLY BE AROUND MINOR TIDAL FLOODING LEVELS...PERHAPS A BIT
OVER. WE LOOK TO FALL IN THE RANGE OF...PROBABLY NOT ENOUGH OVER FOR
STATEMENTS TO BE ISSUED...SO WE WILL GO THIS ROUTE FOR NOW. STAY
TUNED FOR UPDATES LATER TODAY.
THE EAST-NORTHEAST FLOW IS EXPECTED TO CONTINUE DURING THE SUBSEQUENT
TWO TO FOUR HIGH TIDE CYCLES FOR TUE-WED AND IT MAY CAUSE ADDITIONAL
MINOR TIDAL FLOODING IN SOME AREAS.
THE PHILADELPHIA AREA WILL REMAIN HIGHLIGHTED ON THE WWA POINT AND
CLICK MAP BUT IT IS LEAST LIKELY TO EXCEED THE MINOR COASTAL
FLOOD THRESHOLD...DUE TO THE NORTHEAST FLOW.
WAVE RUNUP ALONG THE ATLANTIC SHORES MAY ADD LOCALLY TO THE
INUNDATION IMPACT....ESPECIALLY TUESDAY.
ADDITIONALLY...BEACH EROSION MAY OCCUR.
&&
.RIP CURRENTS...
AN INCREASING NORTHEASTERLY FLOW, COMBINED WITH THE FULL MOON AND
BUILDING WAVES IN THE SURF ZONE, RESULTS IN A MODERATE RISK OF
DANGEROUS RIP CURRENTS TODAY.
A MODERATE TO STRONG NORTHEASTERLY FLOW CONTINUES TUESDAY AND
WEDNESDAY CREATING AT LEAST A MODERATE RISK FOR THE FORMATION OF
DANGEROUS RIP CURRENTS.
SURF SHOULD BUILD TO AT LEAST 5 FEET THIS AFTERNOON... 6 TO
POSSIBLY 8 FEET TUESDAY AND WEDNESDAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ431-452>455.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ430-450-451.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...NIERENBERG/O`HARA
SHORT TERM...O`HARA
LONG TERM...DRAG
AVIATION...DRAG/O`HARA
MARINE...DRAG/O`HARA
TIDES/COASTAL FLOODING...
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 PM EDT TUE SEP 9 2014
.DISCUSSION...
CONVECTIVE LINE FIRED ALONG THE I-4 CORRIDOR ARND SUNSET WITH CELLS
PRODUCING LCL HEAVY RAIN...RADAR ESTIMATED PRECIP BTWN 2.5"-3.0" IN
CENTRAL SEMINOLE COUNTY...KSFB MEASURED 1.35" IN A LITTLE OVER AN
HOUR. BULK OF THE PRECIP HAS BURNED ITSELF OUT...LINGERING LIGHT
RAIN N OF I-4 WILL DISSIPATE BEFORE MIDNIGHT.
EVENING RAOBS SHOW DEEP MOISTURE ACRS THE FL PENINSULA WITH PWAT
VALUES RANGING FROM 2.0"-2.2". RUC ANALYSIS SHOWS INCREASING LOW LVL
MOISTURE UPSTREAM WITH H100-H70 MEAN RH VALUES 80-90PCT OVER THE NRN
BAHAMAS. HOWEVER...DYNAMIC SUPPORT IS LACKING WITH NO ORGANIZED
H85-H50 VORT MAXES AND A CONVERGENT H30-H20 LYR. H85-H70 LAPSE RATES
BTWN 6.5-7.0C/KM REMAIN STEEP ENOUGH TO KEEP THUNDER IN OVERNIGHT...
BUT VALUES DROP BLO 5.0C/KM THRU THE H70-H50 LYR...LEAVING DEEP LYR
INSTABILITY MODEST AT BEST.
MINOR ADJUSTMENTS TO THE TIMING OF COASTAL SHRAS/TSRAS OVERNIGHT...
OTHERWISE FCST IS IN GOOD SHAPE.
&&
.AVIATION...
THRU 10/14Z...E/SE SFC WINDS AOB 5KTS...PREVAILING VFR WITH BRIEF
MVFR CSTL SHRAS S OF KTIX. BTWN 09/14Z-09/16Z...SFC WNDS BCMG E ARND
10KTS...SLGT CHC MVFR SHRAS/IFR TSRAS CSTL SITES. AFT 16Z...CHC MVFR
SHRAS/IFR TSRAS INTERIOR SITES...SLGT CHC CSTL SITES.
&&
.MARINE...
WEAK ATLC RIDGE AXIS OVER N FL WILL GENERATE A LIGHT TO GENTLE ERLY
BREEZE ACRS THE LCL ATLC OVERNIGHT. ISOLD SHRAS WILL FORM S OF THE
CAPE IN THE WAKE EDDIES OF THE NRN BAHAMAS...BUT LITTLE IN THE WAY
OF MID/UPR LVL SUPPORT WILL LIMIT THEIR IMPACT TO BRIEF PDS OF
MODERATE TO HEAVY RAIN...MAINLY OVER THE GULF STREAM. SEAS 2-3FT
WITH DOMINANT PDS ARND 5SEC.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX.....PENDERGRAST
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
202 AM EDT MON SEP 8 2014
.PREV DISCUSSION... /ISSUED 823 PM EDT SUN SEP 7 2014/
UPDATE...
STALLED FRONTAL BOUNDARY REMAINS ACROSS CENTRAL GA THIS EVENING. A
WAVE OF LOW PRESSURE WILL SLOWLY MOVE EAST ALONG THE BOUNDARY
OVERNIGHT. NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE FOR
THE NEXT FEW HOURS...BUT SHOULD BEGIN TO DIMINISH BY MIDNIGHT.
DON`T EXPECT SHRA/TSRA TO COMPLETELY DIMINISH SO HAVE KEPT ISO/SCT
POPS IN FOR THE ENTIRE OVERNIGHT PERIOD. IN LOCALES WHERE IT
RAINED...LOW CLOUDS AND PATCHY FOG ARE POSSIBLE TOWARDS SUNRISE.
HAVE TRIED TO ORIENT POPS ACCORDING TO RADAR TRENDS. THE 19Z RUN
OF THE HRRR PEGGED THE CONVECTION PRETTY WELL...SO ALSO FOLLOWED
SUIT. TEMPS LOOKED GOOD.
PREV DISCUSSION... /ISSUED 735 PM EDT SUN SEP 7 2014/
PREV DISCUSSION... /ISSUED 308 PM EDT SUN SEP 7 2014/
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
MODELS IN GOOD AGREEMENT TAKING THE SURFACE LOW OVER SOUTHEAST GA
AND MOVING IT UP THE COAST. THIS WILL KEEP A NORTHEAST SURFACE FLOW
OVER THE CWA THROUGH MONDAY NIGHT. CURRENT CONVECTION OVER THE CWA
WILL DISSIPATE THIS EVENING. THERE COULD BE AN ISOLATED
SHOWER/TSTORM JUST ABOUT ANYWHERE TONIGHT AND WILL MAINTAIN A 20 POP
ACROSS MOST OF THE CWA. A LITTLE HIGHER POPS ACROSS THE EXTREME
SOUTHEAST PART OF THE CWA TONIGHT DUE TO THE PROXIMITY OF THE
SURFACE LOW. AS THE SURFACE LOW PULLS TO OUR NORTHEAST...SLIGHTLY
DRIER AIR WILL MOVE INTO NORTH GA WITH THE DEEPEST MOISTURE SHIFTING
TO PARTS OF CENTRAL GEORGIA AND THIS IS WHERE THE HIGHEST POPS WILL
BE MONDAY AFTERNOON. ANY CONVECTION THAT DOES FORM WILL DIMINISH
MONDAY NIGHT.
17
LONG TERM /TUESDAY THROUGH SUNDAY/...
A WEAKENING FRONT ACROSS SOUTH GA AND A WEAK WEDGE PERSIST ACROSS
NORTHEAST GA ON TUESDAY. FOR THE REMAINDER OF THE WEEK...UPPER
LEVEL HIGH PRESSURE RETURNS ACROSS THE SOUTHEAST U.S. AND GA
REMAINS IN A MOIST TROPICAL AIR MASS. THIS WOULD SUPPORT ISOLATED
OR SCATTERED THUNDERSTORMS EACH DAY WITH MOSTLY A DIURNAL PATTERN.
BY FRIDAY A FRONT GETS PUSHED INTO NORTH GA AS A BROAD UPPER
TROUGH DEEPENS INTO THE GREAT LAKES. THE FRONT CONTINUES TO SINK
SOUTH ON SATURDAY...HOWEVER THE ECMWF SEEMS A BIT SLOWER WITH
THIS. OVERALL...IT LOOKS LIKE THERE WILL BE SOME DRYING ACROSS THE
NORTH BY THE END OF THE PERIOD. HAVE SHOWN ONLY A SLIGHT CHANCE OF
POPS ACROSS THE NORTH FOR SATURDAY...CHANCE ELSEWHERE.
41/16
&&
.AVIATION...
06Z UPDATE...
LATE NIGHT STORMS CONTINUE TO WEAKEN AND DIMINISH ACROSS THE ATL
METRO AREA. EXPECT IFR-MVFR CIGS TO DEVELOP BY 10Z AND SLOWLY
IMPROVE AFTER 13Z TODAY. CONVECTION WILL ONCE AGAIN FIRE AFTER
16Z...WITH BEST CHANCES 18-22Z...AND GENERALLY SOUTH OF THE ATL-
AHN LINE. FOR NOW HAVE GONE WITH THE PROB30 FOR ALL SITES...BUT
ONLY THE SOUTHERN SITES MAY HAVE THE TEMPO COME THE 12Z ISSUANCE.
EXPECT VRB WINDS AND LOW VFR CIGS WITH STORMS...AND PERIODS OF
HEAVY RAINFALL WILL REDUCE VSBYS. WINDS WILL GENERALLY BE EASTERLY
AT 8 KT OR LESS.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS EXCEPT FOR MEDIUM ON CIGS 10-14Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 66 87 67 / 30 20 20 20
ATLANTA 85 68 86 70 / 30 20 20 10
BLAIRSVILLE 81 62 83 62 / 40 20 20 20
CARTERSVILLE 87 67 88 68 / 30 20 20 10
COLUMBUS 89 71 90 71 / 60 30 30 10
GAINESVILLE 84 66 85 68 / 30 20 20 20
MACON 88 69 90 69 / 50 30 20 20
ROME 89 67 89 67 / 30 20 20 10
PEACHTREE CITY 86 66 87 67 / 40 20 20 10
VIDALIA 87 70 88 71 / 60 40 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
909 PM CDT TUE SEP 9 2014
.DISCUSSION...
900 PM CDT
HEAVY RAINFALL CONTINUES TO BE THE MAIN CONCERN GOING THROUGH
TONIGHT. SURFACE LOW PRESSURE REMAINS STRETCHED FROM THE TEXAS
PANHANDLE TO NORTHWEST MISSOURI WITH A STATIONARY BOUNDARY FROM
EXTREME SOUTHEAST NEBRASKA ACROSS NORTHERN MISSOURI AND ARCHING
SOUTHWARD INTO SOUTHERN ILLINOIS. AN UPPER WAVE MOVING EAST INTO
SOUTHWEST IOWA AND STRENGTHENING LOW LEVEL FLOW HAVE BEEN
TRIGGERING A LARGE AMOUNT OF CONVECTION ACROSS SOUTHEAST NEBRASKA
AND SOUTHERN IOWA WITH A COMPLEX TRACKING EAST ACROSS THE CENTRAL
IA/MO BORDER. AN MCV APPEARS TO HAVE DEVELOPED WITH THIS
CONVECTION ACROSS CENTRAL IOWA. A LARGER AREA OF LESS INTENSE
RAINFALL CONTINUES TO SPREAD NORTHEAST FROM EASTWARD IOWA...WHERE
COVERAGE IS GREATEST...TO MUCH OF WEST CENTRAL ILLINOIS THANKS TO
AN INFLUX OF DEEPER MOISTURE.
THE SURFACE LOW IS EXPECTED TO CONSOLIDATE OVER SOUTHWEST IOWA AND
TRACK NORTHEAST INTO WEDNESDAY MORNING. THE STATIONARY FRONTAL
BOUNDARY IS FORECAST TO LIFT NORTHWARD BUT THE AMOUNT OF
CONVECTION OUT THERE NOW MAY SUPPRESS ITS MOVEMENT INTO THE
OVERNIGHT. HOWEVER...THE STRENGTHENING SYNOPTIC FLOW SHOULD
OVERCOME THIS AT SOME POINT. THE MCV CURRENTLY ACROSS CENTRAL IOWA
IS EXPECTED TO TRACK EAST-NORTHEAST OVERNIGHT BRINGING CONTINUED
CONVECTION WITH IT WHILE THE INCREASING LOW LEVEL JET CONTINUES TO
PRODUCE CONVECTION CLOSER TO THE IA/MO BORDER IN PROXIMITY TO THE
STALLED FRONT...LEADING TO A MORE EAST TO WEST ORIENTED BAND OF
STORMS AT LEAST FOR A TIME INTO THE EARLY OVERNIGHT. THE LIGHTER
SHOWERS AND EMBEDDED STORMS AHEAD OF THIS BETTER ORGANIZED
ACTIVITY WILL CONTINUE TO SPREAD INTO THE CWA INTO THE OVERNIGHT
WITH THE HEAVIER RAINFALL WITH THE MCV AND UPPER WAVE ARRIVING IN
THE WEST LATER TONIGHT. THIS HEAVIER PRECIP WILL THEN TRACK ACROSS
THE CENTRAL AND EASTERN CWA THROUGH THE MORNING. AT THIS POINT THE
MAIN SEVERE POTENTIAL OVERNIGHT WOULD BE CLOSER TO THE FRONT TO
THE SOUTHWEST BUT THE EVOLVING MCV COMPLEX MAY LEAD TO BETTER COLD
POOL DEVELOPMENT WHICH MAY SPELL A WIND THREAT LATER TONIGHT IF AN
ORGANIZED COMPLEX RESULTS. WILL CONTINUE WITH THE FLASH FLOOD
WATCH AND MAKE REFINEMENTS TO POPS...THOUGH THE BIGGEST CHANGE
WILL LIKELY BE TO TIMING DETAILS. IN ADDITION...THE SURFACE LOW
SEEMS TO BE AIMING FOR A TRACK A BIT FURTHER SOUTH TAKING IT
ACROSS CENTRAL INSTEAD OF NORTHERN LAKE MICHIGAN. THIS MAY RESULT
IN SLIGHTLY STRONGER SYNOPTIC WINDS WEDNESDAY MORNING AND EARLY
AFTERNOON...WITH CONVECTION BEING A POTENTIAL LIMITING FACTOR IN
REACHING MAX WIND POTENTIAL.
MDB
&&
.PREV DISCUSSION...
335 PM CDT
SHORT TERM...TONIGHT THROUGH FRIDAY...
MAIN CONCERNS FOR THE FORECAST PERIOD REMAIN THUNDERSTORMS AND HEAVY
RAINFALL ASSOCIATED WITH AN UNUSUALLY STRONG LATE SUMMER COLD FRONT
AND UPPER TROUGH IMPACTING THE REGION FROM LATE TONIGHT INTO
WEDNESDAY EVENING. THEN... FOLLOWING THE PASSAGE OF THIS SYSTEM...
THE FOCUS WILL SHIFT TO THE TEMPERATURE FORECAST AND THE FIRST REAL
TASTE OF AUTUMNAL WEATHER FOR LATER THIS WEEK.
FOR THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING...CONDITIONS
WILL BE THE RELATIVE CALM BEFORE THE STORM. THE SFC LOW IS
BEGINNING TO DEEPEN OVER THE CNTRL PLAINS WHILE HIGH PRESSURE MOVES
OFF THE EAST COAST. INCREASING SOUTHERLY FLOW IS RAMPING UP OVER
THE LOWER AND MIDDLE MISSISSIPPI VALLEY...SETTING UP VERY STRONG
WARM/MOIST ADVECTION POINTING INTO THE MIDWEST. THIS
AFTERNOON...CONVECTIVE ACTIVITY HAS ALREADY BROKEN OUT ALONG THE
NOSE OF A 50 KT LOW LEVEL JET...EXTENDING FROM WRN IOWA INTO CNTRL
IL. THIS STRONG LOW LEVEL JET WILL CONTINUE TO PUMP MOISTURE INTO
THE REGION WHILE MOISTURE ASSOCIATED WITH THE REMNANTS OF HURRICANE
NORBERT ADVECT OVER THE REGION AT THE MID LEVELS. THE MODELS HAVE
BEEN VERY CONSISTENT ON ADVERTISING A SWATH OF PWATS OF 2.0 TO 2.5
INCHES POOLING AHEAD OF THE FRONT. THE LOW LEVEL WARM ADVECTION
AHEAD OF THE FRONT...CONVERGENCE ALONG THE FRONT...A STRONG MID
LEVEL SHORTWAVE AND A COUPLED JET ALOFT WILL ALL COMBINE TO GENERATE
STRONG AND PERSISTENT THUNDERSTORMS. THERE SHOULD BE ADEQUATE SHEAR
IN THE LOW LEVELS BETWEEN SLY SFC WINDS AND 50 KT SWLY WINDS AT
925-850MB TO SUPPORT AN INITIAL CONVECTIVE MODE SUPPORTING SOME
ISOLATED SUPERCELLS ALONG WITH THE GENERAL THUNDER. SPC HAS
OUTLOOKED THE ENTIRE CWA WITH A SLIGHT RISK OVER SEVERE
THUNDERSTORMS...WITH THE PRIMARY THREATS BEING STRONG DAMAGING WINDS
AND MARGINALLY SEVERE HAIL. THE 12Z SOUNDINGS FROM ILX/DVN INDICATE
THE FREEZING LEVEL AT 13KFT AND WITH PERSISTENT WARM ADVECTION AHEAD
OF THE COLD FRONT...THE FREEZING LEVEL WILL LIKELY RISE SOME UNTIL
THE FROPA. SO...WHILE THE ENVIRONMENT SHOULD SUPPORT SOME STRONG
ROTATING UPDRAFTS SUFFICIENT FOR LARGE HAIL...THE HIGH FREEZING
LEVELS SHOULD GIVE AMPLE TIME FOR SOME MELTING. AS FOR THE WIND
THREAT...WITH THE STRONG LOW LEVEL JET POINTING OVER THE
AREA...STRONG WINDS SHOULD BE ABLE TO MIX DOWN...PARTICULARLY IN THE
WARM SECTOR AHEAD OF THE FRONT WHERE SURFACE BASED CONVECTION SHOULD
BE ABLE TO FORM. SO...STRONG...DAMAGING WINDS WILL BE A CONCERN
DURING THE INITIAL THUNDERSTORM DEVELOPMENT LATE THIS EVENING.
HEAVY RAINFALL...
THROUGH THE NIGHT...CONVECTIVE MODE WILL TRANSITION OVER TO MORE
LINES OR CLUSTERS...AND EVENTUALLY CONGEALING INTO A LARGE AREA OF
THUNDERSTORMS. WITH FLOW ABOVE THE BOUNDARY LEVEL TO ABOUT 700MB
SWLY...AND WLY-WNWLY JET-LEVEL WINDS...CELL MOVEMENT WITHIN THE
OVERALL THUNDERSTORM AREA WILL BE TO THE NORTHEAST WHILE THE LARGER
SCALE PATTERN IS SLOWLY PROGRESSIVE TO THE EAST. SO...ANTICIPATE
THAT THERE SHOULD BE AMPLE OPPORTUNITY FOR REPEATED DEVELOPMENT OR
TRAINING OF STORMS. ALL ELEMENTS ARE COMING TOGETHER FOR A
SIGNIFICANT HEAVY RAIN EVENT. STORMS WILL BE EFFICIENT RAIN
PRODUCERS GIVEN THE DEEP LAYER MOISTURE AND RAINFALL RATES OF 2 TO 3
INCHES PER HOUR FROM SOME STORMS WILL NOT BE OUT OF THE QUESTION.
FORTUNATELY...THE PATTERN WILL BE SLOWLY...BUT STEADILY
PROGRESSIVE...SO RAINFALL WILL BE WIDESPREAD RATHER THAN CONFINED TO
A SMALL AREA. LATEST THINKING IS THAT STORM TOTAL QPF SHOULD BE
ARND 2.0 TO 2.5 INCHES. IN AREAS OF TRAINING OR REPEATED STORM
DEVELOPMENT...LOCALIZED AREAS OF 3 TO 5 INCHES TOTAL RAINFALL WILL
BE POSSIBLE. THE MOST FAVORED TIMING FOR THE STRONGEST STORMS WILL
BE LATE THIS EVENING AND OVERNIGHT. THERE MAY BE A BRIEF LULL IN
ACTIVITY DURG THE MORNING HOURS...HOWEVER...EXPECT ANOTHER UPTICK IN
ACTIVITY DURG THE LATE MORNING/EARLY AFTERNOON AS THE COLD FRONT
PUSHES THROUGH NWRN INDIANA.
MAJOR CHANGE IN AIRMASS...
FOLLOWING THE FRONTAL PASSAGE WEDNESDAY AFTERNOON AND EVENING...LOW
WILL TURN NWLY TO NLY BEHIND THE FRONT. WEAK CYCLONIC CURVATURE AND
COLD ADVECTION WILL BRING SOME INSTABILITY SHOWERS IN THE COLDER AIR
BEHIND THE FRONT...THROUGH THURSDAY...A BROAD UPPER TROUGH WILL
CARVE OUT OVER THE CNTRL CONUS. A SERIES OF NORTHERN STREAM
SHORTWAVES WILL HELP INCREASE THE AMPLITUDE OF THE UPPER TROUGH
WHILE SUPPLYING MUCH COOLER AIR TO THE REGION. BY THURSDAY
MORNING...TEMPERATURES SHOULD DROP OFF INTO THE MIDDLE 40S OVER THE
NWRN PORTION OF THE CWA...INCLUDING THE ROCKFORD METRO AREA.
SOUTHEAST OF A LINE FROM CHICAGO TO PONTIAC...LOWS THURSDAY MORNING
SHOULD REMAIN IN THE LOWER TO MIDDLE 50S. TEMPERATURES WILL NOT
HAVE MUCH OPPORTUNITY FOR DIURNAL WARMING THROUGH THE DAY GIVEN THE
PERSISTENT COLD ADVECTION...WITH HIGHS THURSDAY ONLY IN THE LOWER TO
MIDDLE 60S. THERE IS EVEN A CHANCE THAT THE ROCKFORD AREA MAY NOT
BE ABLE TO GET OUT OF THE UPPER 50S. BY FRIDAY MORNING...
TEMPERATURES IN THE LOWER TO MIDDLE 40S WILL COVE THE WHOLE
CWA...AWAY FROM THE URBANIZED PORTION OF THE CHICAGO METRO AREA.
FOR FRIDAY...MAX TEMPS SHOULD BE EVEN LOWER THAN THURSDAY...WITH
NCNTRL/NWRN IL REMAINING IN THE MIDDLE 50S WHILE NERN IL/NWRN IN
SHOULD SEE TEMPS LOW OUT IN THE LOW 60S.
KREIN
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...
THE BIG STORY IN THE EXTENDED PERIOD IS THE REINFORCING SHOT OF
UNSEASONABLY COOL AIR THAT WILL BRING EARLY TO MID OCTOBER
TEMPERATURES OVER THE WEEKEND. IN RESPONSE TO PERSISTENT HIGH
AMPLITUDE RIDGING ALONG THE WEST COAST UP TO ALASKA...A DEEP MEAN
TROUGH WILL LOCK IN OVER THE EASTERN HALF OF CANADA INTO THE
NORTHERN TIER OF THE EASTERN HALF OF THE CONUS. THIS MID/UPPER
PATTERN IS SIMILAR TO WHAT OCCURRED MUCH OF WINTER 2013-14 AND
WILL RESULT IN BELOW NORMAL TEMPERATURES CONTINUING INTO EARLY
NEXT WORK WEEK.
GUIDANCE IS CONSISTENT IN BRINGING A QUICK MOVING BUT DEEP SHORT
WAVE TROUGH OR CLOSED LOW ACROSS THE REGION FRIDAY NIGHT...WITH A
DECENT CHANCE FOR A PERIOD OF RAIN SHOWERS. MAINTAINED CHANCE POPS
IN SMART BLEND...BUT THESE MAY NEED TO BE INCREASED IF TRENDS
HOLD. AIR MASS WILL BE ANOMALOUSLY COOL...DIPPING CLOSE TO 0C AT
850 MB OVER FAR NORTHERN ILLINOIS BY 12Z SATURDAY. PROGRESSION OF
SYSTEM WILL BE KEY IN HOW COLD LOWS ARE BY EARLY SATURDAY...AS
LESS PROGRESSIVE/TIGHTER GRADIENT INDICATED BY RECENT ECMWF RUNS
WOULD INTRODUCE CLOUD COVER CONCERNS. STILL...COLD ADVECTION ALONE
LIKELY SUPPORTS LOWS IN 40S EVERYWHERE BUT IMMEDIATE CITY OF
CHICAGO. POTENTIAL DOES EXIST FOR LAKE EFFECT RAIN SHOWERS INTO
SATURDAY MORNING FOR PORTIONS OF SHORE...MAINLY NW IN...BEFORE
SUBSIDENCE ARRIVES FROM EXPANSIVE HIGH PRESSURE SPREADING IN FROM
WEST.
HIGH TEMPERATURES LOOK TO STRUGGLE INTO LOWER 60S SATURDAY
AFTERNOON. ANOMALOUSLY COOL AIR MASS AND GOOD RADIATIONAL COOLING
SETUP WITH HIGH PRESSURE OVERHEAD SATURDAY NIGHT FAVORS AREAS
OUTSIDE CHICAGO DOWN INTO AT LEAST LOWER 40S...WITH UPPER 30S
POSSIBLE IN TYPICAL COLD SPOTS. DID UNDERCUT SMART BLEND
INITIALIZATION FOR LOWS EARLY SUNDAY...AND LOWS IN 30S IN
OUTLYING AREAS COULD BE MORE WIDESPREAD THAN IN CURRENT FORECAST
IF THERE ARE NO CLOUD COVER ISSUES. WITH MEAN TROUGH OVER
REGION...TEMPERATURES WILL REMAIN BELOW NORMAL REMAINDER OF
EXTENDED...THOUGH SLOW MODERATION THROUGH 60S IS EXPECTED SUNDAY
AND MONDAY. PREVIOUS TWO RUNS OF ECMWF INDICATE ANOTHER SHORT
WAVE/REINFORCING COLD FRONT MONDAY/MONDAY NIGHT. CONFIDENCE IS
LOWER IN THIS PERIOD DUE TO FEATURE BEING MUCH LESS ROBUST ON GFS
AND ITS ENSEMBLES. FOR NOW...GRIDS INDICATE A SLIGHT CHANCE FOR
SHOWERS ON MONDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* ROUND ONE OF SHOWERS WITH EMBEDDED THUNDERSTORMS POSSIBLE
ROUGHLY 04-08Z THIS EVENING.
* ROUND TWO OF THUNDERSTORMS...WITH POTENTIALLY TORRENTIAL RAIN AT
TIMES ROUGHLY 10Z-13Z.
* LOW LEVEL WIND SHEAR CONDITIONS DEVELOPING OVERNIGHT.
* ROUND THREE OF THUNDERSTORMS ROUGHLY 18Z-20Z DEVELOPING VERY
NEAR OR OVER TERMINALS.
* INCREASINGLY GUSTY SOUTH TO SOUTHWEST WINDS VEERING TO NORTHWEST
MID AFTERNOON WEDNESDAY.
BMD
//DISCUSSION...UPDATED 00Z...
AN ACTIVE PERIOD OF WEATHER IS EXPECTED OVER THE NEXT 24 HOURS OR SO
WITH POSSIBLY UP TO THREE DISTINCT ROUNDS OF THUNDER POSSIBLE AT THE
TERMINALS. MOST OF THE REMAINDER OF THE EVENING SHOULD BE QUIET AT
THE TERMINALS WITH MODEST SOUTHERLY FLOW IN PLACE AND VFR
CONDITIONS. HOWEVER A WARM FRONT IS IN PLACE TO OUR SOUTHWEST AND
WILL LIFT ACROSS THE TERMINALS LATE THIS EVENING/TONIGHT BRINGING
RAIN WITH EMBEDDED THUNDERSTORMS. IT APPEARS THE BEST TIME FRAME FOR
THIS WOULD BE ROUGHLY 04-08Z AFTER WHICH THERE SHOULD BE A BIT OF A
LULL IN THE COVERAGE/ACTIVITY AT THE TERMINALS. THE LOW LEVEL JET
WILL BECOME STRONG TO OUR WEST OVERNIGHT AND A STRONGER COMPLEX OF
THUNDERSTORMS IS EXPECTED TO DEVELOP. THESE STORMS ARE EXPECTED TO
PUSH ACROSS THE CHICAGO TERMINALS ROUGHLY BETWEEN 10-13Z...A COUPLE
HOURS EARLIER AT RFD. AS THE LOW LEVEL JET VEERS OVER THE AREA
AROUND THIS TIME...LLWS CONDITIONS ARE PROGGED TO DEVELOP OVERHEAD.
DEEPENING AREA OF LOW PRESSURE WILL LIFT ACROSS IOWA TONIGHT INTO
EAST CENTRAL WISCONSIN BY MIDDAY WEDNESDAY. STRONG SOUTHERLY FLOW IS
EXPECTED TO DEVELOP BECOMING INCREASINGLY GUSTY THROUGH THE PERIOD.
WINDS GUSTING IN EXCESS OF 30 KT ARE EXPECTED AT TIMES THROUGH THE
DAY WEDNESDAY...THOUGH THERE MAY BE CONSIDERABLE VARIABILITY IN THE
MAGNITUDE DUE TO WARM ADVECTION RESULTING IN MARGINAL LOW LEVEL
LAPSE RATES FOR MIXING. A COLD FRONT WILL SWEEP ACROSS THE AREA
EARLY TO MID AFTERNOON AND WILL BE THE FOCUS OF RENEWED AFTERNOON
THUNDERSTORM DEVELOPMENT. BASED ON THE TIMING OF THE
FRONT...THUNDERSTORMS WILL LIKELY DEVELOP SOUTHEAST OF RFD...BUT MAY
DEVELOP OVERHEAD OF NEAR THE CHICAGO TERMINALS BEFORE SHIFTING
SOUTHEAST. THERE IS ALSO A CHANCE THAT THEY COULD DEVELOP SOUTH OF
THE TERMINALS DEPENDING ON HOW THINGS EVOLVE TONIGHT. MAIN POINT
BEING THERE REMAINS A LOT OF UNCERTAINTY IN THIS THIRD ROUND OF
THUNDERSTORMS.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW-MEDIUM CONFIDENCE IN WIDESPREAD THUNDERSTORMS THIS EVENING
(ROUND ONE).
* MEDIUM-HIGH CONFIDENCE IN HEAVY RAIN/THUNDERSTORMS (ROUND TWO)
EARLY WEDNESDAY MORNING.
* LOW CONFIDENCE IN THUNDERSTORMS ON STATION EARLY TO MID
AFTERNOON WEDNESDAY. (ROUND THREE)
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...LOW-MEDIUM CONFIDENCE
IN WIND SPEEDS. MEDIUM CONFIDENCE IN LLWS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR.
FRIDAY...CHC SHRA.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...SLT CHC SHRA.
BMD
&&
.MARINE...
221 PM CDT
THE MAIN FORECAST CONCERNS CONTINUE TO CENTER AROUND A SIGNIFICANT
STORM SYSTEM EXPECTED TO IMPACT THE GREAT LAKES WEDNESDAY AND
WEDNESDAY NIGHT.
SOUTHERLY WINDS ARE EXPECTED TO INCREASE RAPIDLY LATE TONIGHT AS A
STRENGTHENING AREA OF LOW PRESSURE MOVES FROM IOWA INTO SOUTHWESTERN
WISCONSIN. SOUTHERLY GALES OF 35 TO 40 KT ARE EXPECTED BY EARLY
MORNING ACROSS APPROXIMATELY THE SOUTHERN HALF OF THE LAKE...AND
THESE STRONG WINDS WILL CONTINUE THROUGH THE AFTERNOON. THE LOW IS
THEN EXPECTED TO SHIFT ACROSS THE NORTHERN PORTION OF THE LAKE BY
WEDNESDAY EVENING...AND THIS SHOULD RESULT IN A SHORT PERIOD OF
LIGHT AND VARIABLE WINDS NEAR ITS TRACK EARLY THURSDAY EVENING.
HOWEVER...ONCE THIS LOW SHIFTS EAST OF THE LAKE BY LATER WEDNESDAY
EVENING...A STRONG COLD FRONT WILL PUSH OVER THE LAKE. THIS SHOULD
ALLOW FOR A PERIOD OF STRONG NORTH-NORTHWESTERLY WINDS OVER THE LAKE
INTO THURSDAY. AT THIS TIME...IT APPEARS THE MAIN THREAT FOR GALES
MAY SHIFT OVER THE NORTHERN HALF OF THE LAKE INTO EARLY THURSDAY
MORNING...WITH NEAR GALE FORCE WINDS POSSIBLE OVER THE SOUTHERN END
OF THE LAKE.
WINDS WILL GRADUALLY ABATE SOME INTO THE LATER PORTION OF THE WEEK
AS HIGH PRESSURE BUILDS IN ACROSS THE PLAINS AND UPPER MIDWEST.
HOWEVER...THE NORTHERLY FETCH WILL LIKELY CONTINUE TO PRODUCE SOME
HIGHER 4 + FOOT WAVES THROUGH AT LEAST FRIDAY. ANOTHER SYSTEM COULD
IMPACT PORTIONS OF THE LAKE ON SATURDAY...POSSIBLY LEADING TO A
PERIOD OF ENHANCED NORTHERLY WINDS AGAIN. HOWEVER...UNCERTAINTY IS
HIGH WITH THIS SYSTEM. IF THE SYSTEM DOES PAN OUT...IT COULD RESULT
IN WAVES HIGH ENOUGH TO SUPPORT A SMALL CRAFT ADVISORY INTO
SATURDAY.
AS FOR HEADLINES...WE HAVE ISSUED A GALE WARNING FOR THE SOUTHERN
HALF OF THE LAKE...INCLUDING THE NEAR SHORES...FOR THE DAY ON WED
WHEN STRONG SOUTHERLY WINDS ARE EXPECTED. DUE TO UNCERTAINTIES ON HOW
STRONG THE NORTHERLY WINDS WILL BE ON OVER SOUTHERN LAKE MICHIGAN ON
THE BACK SIDE OF THE SYSTEM...WE HAVE OPTED TO KEEP THE WATCH IN
PLACE FOR WEDNESDAY NIGHT FOLLOWING THE SOUTHERLY GALE EVENT.
HOWEVER...OVER THE NORTHERN PORTION OF THE LAKE NORTHERLY GALES
APPEAR MORE LIKELY WEDNESDAY NIGHT..SO WE HAVE ISSUED THE GALE
WARNING THERE FOR WEDNESDAY EVENING THROUGH EARLY THURSDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ032...1 AM WEDNESDAY TO 1 PM WEDNESDAY.
BEACH HAZARDS STATEMENT...ILZ006-ILZ014...5 AM WEDNESDAY TO NOON
WEDNESDAY.
FLASH FLOOD WATCH...ILZ023-ILZ033-ILZ039...7 AM WEDNESDAY TO 7
PM WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...7 AM
WEDNESDAY TO 7 PM WEDNESDAY.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 AM WEDNESDAY TO 7 PM
WEDNESDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 PM
WEDNESDAY TO 10 AM THURSDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...5 PM
WEDNESDAY TO 10 AM THURSDAY.
&&
$$
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[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
901 PM CDT Tue Sep 9 2014
.UPDATE...
ISSUED AT 900 PM CDT TUE SEP 9 2014
The 35-45kt low level jet around 850mb is progressing toward IL
from the SW. Moisture transport is increasing as a result, with
PWAT values climbing toward 2 inches. The nearly stationary warm
from angled from NW to SE in eastern Missouri will continue to
provide a lifting mechanism for shower/storm development the rest
of the night.
A progressive MCS is forecast by the high res models to move from
NW Missouri across N IL overnight, which will possibly clip our NW
counties after midnight. Areas NW of the IL river will have the
best chances of getting heavy rain and strong winds from that
complex. We kept categorical PoPs for that area overnight, with
heavy rain in the grids. The flash flood watch coverage still
looks good for timing and coverage. No changes will be needed
there.
The severe threat for Wed afternoon still hinges greatly on the
amount of sunshine that develops ahead of the cold front. Wind
shear will be present, as well as plenty of moisture, so
instability will be the question-mark. Forecast soundings show
limited instability even during the afternoon due to a moist
adiabatic profile, but areas of clearing and heating can quickly
produce high CAPEs. Will keep tomorrows forecast as is, with
severe potential for nearly all of our counties except western
portions of Knox and Stark counties.
Even update mainly for weather/PoPs.
&&
.SHORT TERM...(Tonight)
ISSUED AT 305 PM CDT TUE SEP 9 2014
Issued a flash flood watch for areas from I-55 west from this
afternoon through 7 pm Wed. Issued flash flood watch for east
central IL for Wed afternoon and Wed evening. MCS still affecting
a part of central IL with showers and thunderstorms sw of I-74 and
west of I-57. Thunderstorms with heavy rains over parts of Morgan
and southern Sangamon counties. Have increased chances of showers
and thunderstorms over central and western areas tonight with
heaviest rains shifting into areas nw of the IL river during the
night. SPC continues a slight risk of severe storms from I-55 nw
into tonight with main threat damaging wind gusts where 30% risk
nw of IL river. Muggy lows in the upper 60s to around 70F with
south southeast winds prevailing tonight.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 305 PM CDT TUE SEP 9 2014
Showers and thunderstorms will likely be ongoing to start the day
for much of the forecast area west of I-55. This convective complex
will be tied fairly closely to a deepening surface low that will be
lifting into the Great Lakes region during the day. East of I-55 the
day will likely start out dry. Then, attention turns to the cold
front trailing from the surface low. This strong front will sweep
through the forecast area, mainly during the Wednesday afternoon and
evening hours. Unfortunately, there are still model disagreements
with the speed of the front, differences that will likely have a
significant impact on our severe weather threat. The ECMWF remains
the slowest, while the NAM has trended faster and is now closer to
the GFS speed. However, WPC does not favor the NAM`s recent trend of
a deeper surface low and associated faster frontal speed. So, will
continue to favor the more consistent ECMWF (although the GFS has
been fairly consistent with is quicker solution).
Severe storms and heavy rainfall are still a threat until the cold
front clears the area. The main severe storm threat still appears to
be in the Wednesday afternoon/evening hours along/ahead of the cold
front where the best pre-frontal instability (1500-2500 j/kg) and
bulk shear (35-45 kts) will be co-located. However, if a faster
frontal speed verifies, the instability will likely end up quite a
bit lower and reduce the severe threat. Any storms until the front
clears the area have the potential to be heavy rain producers, with
precipitable water values apt to be in excess 2 inches.
Once the strong cold front clears the area by late Wednesday night,
a much cooler than normal weather pattern should linger through the
end of the forecast period. Upper level troffing should remain in
place, accompanied by a Canadian surface high more often than not.
There are still some stronger waves expected to track through the
mean trof that may produce rainfall. However, model agreement in
this regard still leaves much to be desired, especially next week.
At this point, the best model clustering suggests showers are
possible later Friday into Friday night, and this is the only period
I have left slight chances for showers in place. Temperatures to
start the period should average 60s for highs and 40s for lows,
climbing into the 70s and 50s respectively by the end of the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 649 PM CDT TUE SEP 9 2014
Bands of thunderstorms will progress eastward toward I-57 this
evening, but the eastern edge should not advance much farther than
that until later tonight and tomorrow. We kept a VCSH for the
eastern TAFs this evening. All TAFs included a short tempo for
MVFR vis in any heavier downpours this evening. Ceilings could dip
below 3k FT for short periods of time as well, but prevailing
cloud levels should remain VFR.
Low level wind shear still looks like a good bet for later tonight
for our western TAFs as the southerly LLJ increases to 45kt around
2k FT. We did not include DEC and CMI in the LLWS for now, based
on the latest RAP model output.
As the cold front approaches tomorrow, winds will increase out of
the south-southwest, with gusts to near 30kt at times. Strong to
severe storms with damaging winds will be possible at all TAF
sites tomorrow afternoon ahead of the front. We did not include
any tempos for those conditions yet, but left VCTS in the
afternoon for now.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through Wednesday evening FOR ILZ027>031-
036>038-040>042-047>051.
FLASH FLOOD WATCH from Wednesday afternoon through late
Wednesday night FOR ILZ043>046-052>057-061.
&&
$$
UPDATE...SHIMON
SHORT TERM...07
LONG TERM...BAK
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
258 PM CDT MON SEP 8 2014
.DISCUSSION...
247 PM CDT
MAIN CONCERNS FOR THE FORECAST PERIOD WILL FOCUS ON THUNDERSTORMS
AND HEAVY RAINFALL ASSOCIATED WITH AN UNUSUALLY STRONG LATE SUMMER
COLD FRONT AND UPPER TROUGH IMPACTING THE REGION FROM TUESDAY NIGHT
INTO WEDNESDAY NIGHT. FOLLOWING THE PASSAGE OF THIS SYSTEM...THE
FOCUS WILL SHIFT TO THE TEMPERATURE FORECAST AND THE FIRST REAL
TASTE OF AUTUMNAL WEATHER FOR LATER THIS WEEK.
FOR THE REMAINDER OF THIS AFTERNOON INTO THE EVENING...CONTINUOUS
WILL REMAIN QUIET. THE ONLY ITEM OF CONCERN IS AN OLD MCS TRACKING
ACROSS NRN IOWA. DO NOT ANTICIPATE THAT ANY PCPN WILL HANG TOGETHER
LONG ENOUGH TO IMPACT THE CWA...BUT RATHER EXPECT INCREASING MID AND
HIGH CLOUDS ENCROACHING ON THE NRN PORTIONS OF THE CWA.
THE FLOW PATTERN ALOFT CONTINUES TO BE VERY LOW AMPLITUDE WITH THE
FASTER WESTERLIES ACROSS THE NRN CONUS AND BROAD RIDGING OVER THE
SRN CONUS. WEAK SHORTWAVES RIPPLING THROUGH THE FAST ZONAL FLOW
ALOFT WILL BRING THE INITIAL CHANCES FOR PCPN LATE TONIGHT. THE
ANTICIPATED TRACK OF THE ASSOCIATED SHORT WAVE WOULD BRING THE
GREATEST CHANCE FOR SHOWERS AND SOME SCATTERED
THUNDERSTORMS...MOSTLY AFTER MIDNIGHT WITH SOME LINGERING PCPN
POSSIBLE INTO EARLY TUESDAY MORNING.
THE SYSTEM OF GREATER CONCERN IS SHAPING UP FOR LATE TUESDAY NIGHT
THROUGH WEDNESDAY. THE LARGE SCALE MODELS HAVE BEEN CONSISTENT IN
ADVERTISING A HEAVY RAIN EVENT WITH THE POSSIBILITY OF SEVERE
THUNDERSTORMS. THROUGH TUESDAY...THE UPPER LEVEL PATTERN WILL
UNDERGO AN AMPLIFICATION PROCESS WITH UPPER TROUGHING DEVELOPING
OVER THE WRN CONUS WITH BROAD RIDGING OVER THE CNTRL AND ERN CONUS.
THE UPPER TROUGH WILL TAP SOME RESIDUAL MOISTURE FROM THE REMNANTS
OF EASTERN PACIFIC HURRICANE NORBERT. ADDITIONALLY...LEE TROUGH
DEVELOPMENT OVER THE CENTRAL PLAINS WILL HELP OPEN UP THE GLFMEX AND
INCREASINGLY SOUTHERLY TO SOUTHWESTERLY FLOW AT THE SFC ALOFT WILL
SET UP AN EXTENDED PERIOD OF WARM/MOIST ADVECTION. THE LARGER SCALE
MODEL GUIDANCE HAS BEEN CONSISTENT IN ADVERTISING COPIOUS AMOUNTS OF
MOISTURE POOLING ALONG AND AHEAD OF THE SFC COLD FRONT...WITH AN
AREA OF PWATS IN EXCESS OF 2 INCHES MOVING OVER THE REGION AS THE
COLD FRONT PUSHES EWD ACROSS THE CNTRL PLAINS AND INTO THE MIDWEST.
WITH THE STRONGEST WESTERLY SHUNTING TO THE NORTH WITH THE
AMPLIFYING UPPER LEVEL PATTER...THE ASSOCIATED SFC LOW WILL TAKE A
NELY TRACK FROM THE CNTRL PLAINS TUESDAY INTO CENTRAL WISCONSIN BY
MIDDAY WEDNESDAY...AND THEN THROUGH THE UPPER GREAT LAKES WEDNESDAY
NIGHT. THE NET EFFECT OF THIS EVOLUTION WILL BE TO SLOW THE
PROGRESSION OF THE SRN END OF THE FRONT...WITH EXTENSIVE TRAINING OF
THUNDERSTORMS IN THE DEEPER LEVEL SWLY FLOW ALOFT. WITH THE LATEST
FORECAST UPDATE...WILL CARRY AROUND 2 INCHES OF STORM TOTAL
WIDESPREAD QPF WITH THE SYSTEM FROM LATE TUESDAY NIGHT INTO EARLY
WEDNESDAY EVENING. HOWEVER...WITH TRAINING THUNDERSTORMS LIKELY
ALONG WITH A VERY MOIST AIRMASS...THE 2 INCH AMOUNTS MAY BE A
CONSERVATIVE AREAL AVERAGE AMOUNT AS LOCALIZED TRAINING AND STRONG
TO POTENTIALLY SEVERE THUNDERSTORMS WILL BE VERY EFFICIENT PCPN
PRODUCERS. THE PERIOD OF TIME WHICH THE HEAVIEST RAINFALL IS
EXPECTED WILL BE FROM LATE MORNING THROUGH LATE AFTERNOON WEDNESDAY
AS THE LEADING EDGE OF A 50KT+ LOW LEVEL JET POINTS INTO NRN IL/SERN
WI AND THEN SLOWLY TRANSLATES INTO NWRN INDIANA. THE STRONG VEERING
OF WINDS THROUGH THE LOWER LEVELS SHOULD BE SUFFICIENT TO SUPPORT
STRONG ROTATING UPDRAFTS CONDUCIVE TO SUPERCELL DEVELOPMENT ON THE
LEADING EDGE OF THE LOW LEVEL JET...BUT ACTIVITY SHOULD EVOLVE INTO
MORE ORGANIZED LINES OR CLUSTERS OF STORMS. THE GREATEST SEVERE
THREAT SHOULD BE STRONG...DAMAGING WINDS GIVEN THE STRONG LOW LEVEL
SHEAR. WHILE THE POSSIBILITY OF LARGE HAIL IS NOT OUT OF THE
QUESTION...THE FREEZING LEVEL WILL BE CLOSE TO 16KFT...SO A
CONSIDERABLE AMOUNT OF MELTING COULD OCCUR BEFORE HAIL REACHES THE
GROUND.
THE COLD FRONT SHOULD FINALLY PUSH EAST OF THE CWA...BRINGING AN END
TO ANY LINGERING PCPN OVER THE FAR SERN PORTIONS OF THE CWA BY
DAYBREAK EARLY THURSDAY MORNING. AS THE SFC LOW ASSOCIATED WITH THIS
SYSTEM MOVES OFF INTO THE CANADIAN MARITIME PROVINCES THURSDAY
NIGHT...A BROAD UPPER TROUGH WILL DROP OUT OF CANADA...BRINGING A
SIGNIFICANTLY COLDER AIRMASS ACROSS THE NRN PLAINS AND UPPER
MIDWEST. THE GFS/ECMWF ARE RELATIVELY CONSISTENT ON BRINGING THE 0C
850MB ISOTHERM CLOSE TO THE WISCONSIN BORDER BY THURSDAY EVENING
WHILE BROAD HIGH PRESSURE SPREADS ACROSS THE CNTRL/NRN PLAINS AND
UPPER MISSISSIPPI VALLEY. THROUGH THE DAY ON FRIDAY...THE 0C 850MB
TEMPS ARE EXPECTED TO REACH INTO NRN IL...WHICH IS DOWNRIGHT CHILLY
FOR MID SEPTEMBER. THE TEMPERATURE CONTRAST ACROSS THE COLD FRONT
WILL BE VERY NOTABLE...WITH TEMPERATURES DROPPING OFF FROM THE UPPER
70S TO LOWER 80S ON WEDNESDAY INTO THE MIDDLE 40S TO AROUND 50F
THURSDAY MORNING. STRONG...PERSISTENT COLD ADVECTION THROUGH A DEEP
LAYER OF THE ATMOSPHERE WILL SET UP A MUCH COOLER PERIOD BEGINNING
THURSDAY AND CONTINUING THROUGH THE WEEKEND WITH HIGHS GENERALLY IN
THE UPPER 50S TO LOWER 60S. IF THIS PATTERN WOULD OCCUR JUST A
COUPLE WEEKS LATER...WITH A LOWER SUN ANGLE...THE AREA COULD SEE
HIGHS POTENTIALLY IN THE UPPER 40S TO LOWER 50S. HOWEVER...A HIGHER
SUN ANGLE AND AMPLE SUNSHINE SHOULD LIMIT THE DEGREE OF COOLING.
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK...ONLY EXPECT SLOW
MODERATION TO TEMPERATURES AS A STEADY STREAM OF NRN STREAM
SHORTWAVE ENERGY WILL CONTINUE TO CARVE OUT A BROAD UPPER THROUGH
OVER THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES REGIONS...GIVING
LITTLE OPPORTUNITY FOR ANY SIGNIFICANT WARMING.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTHERLY WINDS SPORADICALLY GUSTING TO OVER 10 KT THIS
AFTERNOON.
* SLIGHT CHANCE FOR SHRA TUESDAY MORNING...WITH A CHANCE FOR TSRA
IN THE WESTERN TRACON AREA.
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE IS BEGINNING TO PULL AWAY WITH SOUTHERLY WINDS
ENCOMPASSING THE AREA. THE WIND DIRECTION AT CHICAGOLAND TAF
SITES HAS AND LIKELY WILL CONTINUE TO BE SOMEWHAT VARIABLE BETWEEN
SOUTHWEST AND SOUTHEAST. WHILE ORD AND MDW OBSERVATIONS HAVE
INDICATED A FEW GUSTS IN EXCESS OF 10 KT...BELIEVE THAT SUCH GUSTS
WILL BE INFREQUENT BASED ON THE ATMOSPHERIC PROFILE THIS
AFTERNOON. PER OBSERVATIONAL TRENDS...THE LAKE BREEZE LOOKS TO
VERY LIKELY STAY EAST OF ORD AND MDW. THE SYNOPTIC WIND WILL
LIKELY STILL OFFER ENOUGH OF A SOUTHEAST COMPONENT TO TURN THE
WINDS SLIGHTLY EAST OF SOUTH FROM TIME TO TIME THIS
AFTERNOON...BUT AGAIN SPEEDS SHOULD BE 6-10 KT MUCH OF THE TIME.
THUNDERSTORMS OVER WESTERN IA HAD DIFFICULTLY EVOLVING EASTWARD
THIS MORNING. AS AN UPPER LEVEL DISTURBANCE MOVES INTO THIS AREA
AND ADVANCED EAST...IT SHOULD HELP SHOWERS AND STORMS TO DO THE
SAME. AN UPTICK IN COVERAGE IS EXPECTED THIS EVE ACROSS EASTERN IA
AND POSSIBLY INTO NORTHWESTERN/WESTERN IL AS THE NIGHT PROGRESSES.
THE ATMOSPHERE FAVORS ANY ORGANIZED AREA OF SHOWERS AND STORMS TO
MOVE SOUTHEAST. RIGHT NOW ITS DIFFICULT TO SAY IF SHOWERS WILL
REMAIN WEST OF CHICAGOLAND SITES TUESDAY MORNING...HOWEVER THERE
IS GREATER CONFIDENCE THAT TSRA WILL STAY WEST/SOUTHWEST THROUGH
TUESDAY MORNING.
A POTENTIALLY ACTIVE AND IMPACTING PERIOD TO AVIATION WEATHER AT
AREA TAF SITES APPEARS TO BE SHAPING UP LATE TUESDAY NIGHT THROUGH
WEDNESDAY WITH A PROBABLE PERIOD OR PERIODS OF STORMS...GUSTY
SOUTHERLY WINDS...AND POTENTIALLY LOW CLOUDS WEDNESDAY MORNING.
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM THAT WINDS WILL NOT FREQUENTLY BE GREATER THAN 10 KT.
* MEDIUM IN SHRA REMAINING WEST OF THE AIRFIELDS TUESDAY MORNING.
HIGH THAT TSRA WILL REMAIN WEST OF THE AIRFIELDS TUESDAY MORNING.
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 18Z...
TUESDAY NIGHT...CHC SHRA/TSRA INCREASING OVERNIGHT. SOUTHERLY
WINDS INCREASING WITH 40 KT FLOW AROUND 1000-1500 FT.
WEDNESDAY...SHRA/TSRA LIKELY ESPECIALLY IN THE MORNING. GUSTY
SOUTHERLY WINDS...AT TIMES TO 25 KT AND POSSIBLY 30 KT. MAINLY
VFR...BUT PATCHY IFR IN STRONGER SHRA/TSRA.
THURSDAY THROUGH SUNDAY...MAINLY VFR.
MTF
&&
.MARINE...
156 PM CDT
THE MAIN FORECAST CONCERNS CENTER AROUND A SIGNIFICANT STORM SYSTEM
EXPECTED TO IMPACT THE GREAT LAKES WEDNESDAY THROUGH THURSDAY.
SOUTHERLY WINDS ARE EXPECTED TO INCREASE RAPIDLY AROUND OR SHORTLY
AFTER DAYBREAK WEDNESDAY AS A STRENGTHENING AREA OF LOW PRESSURE
MOVES FROM IOWA INTO SOUTHWESTERN WISCONSIN. SOUTHERLY GALES OF 35
TO 40 KT ARE PROBABLE BY MID TO LATE MORNING...ESPECIALLY ACROSS THE
SOUTHERN HALF TO 2/3RDS OF THE LAKE...AND THESE STRONG WINDS LOOK TO
CONTINUE THROUGH WEDNESDAY AFTERNOON. THE LOW IS THEN EXPECTED TO
SHIFT SOMEWHERE ACROSS THE NORTHERN PORTION OF THE LAKE BY WEDNESDAY
EVENING. THIS COULD RESULT IN A SHORT PERIOD OF LIGHT AND VARIABLE
WINDS ACROSS NORTHERN SECTIONS OF THE LAKE EARLY WEDNESDAY EVENING.
HOWEVER...ONCE THIS LOW SHIFTS EAST OF THE LAKE BY LATER WEDNESDAY
EVENING...A STRONG COLD FRONT WILL PUSH OVER THE LAKE...WITH A
PERIOD OF NORTHWESTERLY GALES LOOKING LIKE A DECENT BET ACROSS MOST
OF THE LAKE INTO EARLY THURSDAY.
THE WINDS WILL GRADUALLY ABATE SOME INTO THE LATER PORTION OF THE
WEEK AS HIGH PRESSURE BUILDS IN ACROSS THE PLAINS AND UPPER
MIDWEST. HOWEVER...THE NORTHERLY FETCH WILL LIKELY CONTINUE TO
PRODUCE SOME HIGHER 4 + FOOT WAVES THROUGH FRIDAY.
AS FOR HEADLINES...WE HAVE ISSUED A GALE WATCH FOR THE SOUTHERN
2/3RDS OF THE OPEN WATERS FROM 14 UTC WED THROUGH 15 UTC THURS
AND FOR THE NORTHERN PORTION OF THE LAKE FROM 03 UTC THURS THROUGH
15 UTC THURS. HOWEVER...AT THIS TIME I HAVE OPTED TO LEAVE THE
ILLINOIS AND INDIANA NEAR SHORES OUT OF THE GALE WATCH DUE TO THE
OFFSHORE COMPONENT OF THE FLOW AND THEIR PROXIMITY TO THE SURFACE LOW.
HOWEVER...GALE FORCE GUSTS ARE CERTAINLY POSSIBLE IN THE NEAR SHORES
AS WELL...AND THIS MAY NEED TO BE ADDED TO THE WATCH IN FUTURE
FORECAST UPDATES. AT THE VERY LEAST...A HIGH END SMALL CRAFT
ADVISORY WITH WINDS TO 30 KT WILL LIKELY BE NEEDED FOR THE NEAR
SHORE WATERS FOR WEDNESDAY THROUGH THE END OF THE WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WATCH...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878...9 AM WEDNESDAY TO 10 AM THURSDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ563...7 PM WEDNESDAY TO 10
AM THURSDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
254 PM CDT Mon Sep 8 2014
.SHORT TERM...(Tonight)
ISSUED AT 253 PM CDT MON SEP 8 2014
A surface high pressure ridge across extreme eastern and southeast
IL early this afternoon will gradually shift to the east this
evening. This will allow a light, south return flow to develop. The
18z surface analysis indicated dew points in the lower-middle 50s in
much of central IL. However, moist low level air is as close as west
central MO - so it doesn`t have far to go to make a return to
central IL.
A prominent outflow boundary from northeast to south central IA is
expected to provide the focus for MCS development tonight. The short
range models are is disagreement as to the track of the MCS and its
associated remnants into west central IL overnight. Prefer the RAP,
and to a certain extent a blend of the NAM and GFS, solution of the
eastern edge of the precipitation shield getting close to the IL
Valley after Midnight and just west of I-55 around daybreak. Drier
air in eastern IL should work to erode the eastern edge from
progressing much further.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 253 PM CDT MON SEP 8 2014
Not too many changes needed to the forecast over the next several
days. While minor tweaks are required for the latest model trends,
the overall picture has remained the same.
Relatively low precipitation chances, mainly over the western
portion of the forecast area, are appropriate through Tuesday night.
These PoPs are the result of diurnal convection firing along an
outflow boundary from tonight`s upstream MCS Tuesday and/or from the
approach of our main midweek system by late Tuesday night.
Our main precipitation threat is still on track for Wednesday and
Wednesday night. This will occur courtesy of a potent upper level
wave, associated surface low, and strong trailing cold front. A
decent severe thunderstorm threat also exists ahead of the cold
front, mainly Wednesday afternoon and evening. The main concern for
nailing down too many specifics is the spread that persists with
respect to the speed of trailing cold front. The slower solutions,
most notably the 12Z ECMWF, will offer the most time for instability
to build on Wednesday before the arrival of the front and increase
the severe weather threat. Most models continue to point a general
35-45kt bulk shear gradient from south to north across the forecast
area ahead of the front. A middle of the road solution to
instability, accounting for differences in frontal speed, should
support CAPE values of 1500-2500 j/kg. Heavy rain still looks to be
a threat across the entire forecast area, severe weather or not,
given the precipitable water values in excess of 2 inches forecast
on the warm side of this system ahead of the cold front.
Once the strong cold front clears the area by late Wednesday night,
a much cooler than normal weather pattern should linger through the
end of the forecast period. Upper level troffing should remain in
place, accompanied by a Canadian surface high more often than not.
There are still some stronger waves expected to track through the
mean trof that may produce some rainfall over the last few days of
the forecast. However, model agreement in this regard still leaves
much to be desired. At this point, the best model clustering
suggests showers are possible later Friday into Friday night, and
this is the only period I have left slight chances for showers in
place. Temperatures through the period should average 60s for highs
and 40s for lows.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 100 PM CDT MON SEP 8 2014
VFR conditions can generally be expected the next 24 hours in
central and eastern IL. A surface high pressure ridge will remain
over eastern IL into this evening with a southerly return flow
developing in central IL. However, the biggest question will be
how much return flow of low level moisture occurs, especially west
of I-55. Most of the shorter range models are depicting the
development of another MCS in Iowa overnight. However, they differ
on where the remnants may track. The HRRR seems to be too far
north with its rainfall, while the NAM and RAP keep the bulk of
the thunderstorms in SE Iowa and west central IL closer to the
lower level theta-e ridge.
With the best low level moisture advection/moisture transport
expected to be near the MS River and the forecast of Corfidi
vectors to be pointing toward the southeast, will only put a
mention of VCTS in the forecast for KPIA, with the possibility of
a VCSH along I-55 from KBMI-KSPI Tuesday morning after daybreak.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...BAK
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
157 PM CDT MON SEP 8 2014
.DISCUSSION...
350 AM CDT
PRIMARY FOCUS REMAINS ON DEEP LOW PRESSURE SYSTEM WHICH WILL MOVE
THROUGH THE UPPER MIDWEST TUESDAY NIGHT THROUGH WEDNESDAY...AND
ASSOCIATED RAIN/THUNDER TRENDS. MUCH COOLER AIR ARRIVES LATER
WEDNESDAY NIGHT IN THE WAKE OF THIS SYSTEM...WITH A REINFORCING PUSH
OF COOLER AIR FRIDAY.
IN THE NEAR TERM...ARE REMAINS UNDER INFLUENCE OF SURFACE HIGH
PRESSURE RIDGE TODAY. A SHORT WAVE MOVING NORTH OF THE CWA MAY
SPREAD A LITTLE HIGH CLOUD COVER ALONG WITH SOME CIRRUS FROM
CONVECTION WELL TO OUR NORTHWEST TODAY...THOUGH GENERALLY DRY AND
MILD CONDITIONS EXPECTED. LOW LEVEL MOIST ADVECTION RAMPS UP TO OUR
WEST TONIGHT WITH THUNDERSTORM DEVELOPMENT ANTICIPATED ACROSS THE
UPPER MISSISSIPPI VALLEY. HIGH-RES GUIDANCE FOCUSES ON NORTHEAST
IOWA LATER IN THE NIGHT...WITH INDICATIONS OF MCS REMNANTS MOVING
INTO NORTHWEST LATE AND CONTINUING TO PROPAGATE SOUTHEAST ACROSS
NORTH CENTRAL...WEST CENTRAL AND CENTRAL ILLINOIS AS SYSTEM DECAYS
TUESDAY MORNING. DRIER LOW LEVEL AIR ASSOCIATED WITH THE RETREATING
HIGH TO THE EAST...AND INSTABILITY AXIS FOCUSED FARTHER TO THE
WEST/SOUTHWEST BOTH SUPPORT HIGHEST POPS ACROSS FAR SOUTHWESTERN
PARTS OF THE CWA LATE TONIGHT AND EARLY TUESDAY.
TURNING OUR ATTENTION BACK TO THE WEST TUESDAY...CYCLOGENESIS TAKES
PLACE ACROSS THE PLAINS IN RESPONSE TO AMPLIFICATION OF UPPER TROUGH
ACROSS THE WESTERN CONUS. RESULTING STRENGTHENING IN SOUTHERLY
RETURN FLOW AND STRONG MOISTURE ADVECTION DEVELOPS INTO THE AREA
TUESDAY NIGHT...WITH ANOMALOUSLY STRONG MOISTURE TRANSPORT FOR
SEPTEMBER LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING. TAPPING OF
SOUTHWEST MONSOONAL MOISTURE AS WELL AS SOME REMNANTS OF MOISTURE
ASSOCIATED WITH HURRICANE NORBERT BRINGS PWATS OF 2+ INCHES INTO THE
AREA IN PRE-COLD FRONTAL THETA-E PLUME. THIS SUPPORTS HEAVY RAINFALL
THREAT (1.5-2.0 INCH AERIAL AMOUNTS) ACROSS NORTHERN IL EARLY
WEDNESDAY...SHIFTING INTO CENTRAL IL AND NORTHWEST INDIANA WEDNESDAY
AFTERNOON AHEAD OF COLD FRONT WHICH MOVES THROUGH DURING THE
AFTERNOON AND EVENING HOURS. IN ADDITION...THIS STRONG DYNAMIC
SYSTEM ALSO PRESENTS THE THREAT OF SEVERE WEATHER PARTICULARLY
MIDDAY WEDNESDAY AND WEDNESDAY AFTERNOON AS STRONG DEEP LAYER SHEAR
AND WEAK-MODERATE INSTABILITY COMBINE FOR SOME DEGREE OF A DAMAGING
WIND THREAT. SPC HAS NORTHWEST PART OF THE CWA IN THE DAY 2 SLIGHT
RISK...THOUGH AREA WILL BE IN LESS NOCTURNALLY FAVORED TIMING OF
BEST STORM THREAT TUESDAY. DAY 3 SLIGHT RISK ACROSS MOST OF THE CWA
WILL BE BETTER ALIGNED WITH DIURNAL CYCLE...ESPECIALLY ACROSS THE
SOUTHEAST PORTION OF THE FORECAST AREA WHERE COLD FRONT WILL BE
APPROACHING DURING THE AFTERNOON. EXTENSIVE CLOUD COVER AND PRECIP
EARLY WEDNESDAY WILL NO DOUBT PLAY A LARGE ROLE IN MODULATING
LOCATION AND EXTENT OF SEVERE THREAT...LEAVING SOME UNCERTAINTIES AT
THIS DISTANCE.
FIRST REAL TASTE OF AUTUMNAL COOL AIR SPREADS IN WEDNESDAY NIGHT AND
THURSDAY AS THE LOW PULLS AWAY FROM THE GREAT LAKES. HIGHS IN THE
60S AND LOWS IN THE UPPER 40S/50S CHARACTERIZE THE REMAINDER OF THE
FORECAST PERIOD...WITH HIGHS PERHAPS NOT GETTING ABOVE 65
FRIDAY-SATURDAY WITH A SECONDARY PUSH OF COOLER AIR. THIS SECONDARY
COLD FRONT MAY ALSO SPUR A FEW SHOWERS FRIDAY WITH MID-LEVEL SHORT
WAVE PASSING ACROSS THE AREA DURING THE DAY. SURFACE HIGH PRESSURE
RIDGE OVER THE WEEKEND SHOULD ALLOW RELATIVELY DRY CONDITIONS
DESPITE THE COOL TEMPS...THOUGH A FEW LAKE EFFECT SHOWERS WILL BE
POSSIBLE ACROSS NORTHWEST INDIANA ESPECIALLY FRIDAY NIGHT AND
SATURDAY WITH INSTABILITY INDUCED BY COOL AIR OVER MILD LAKE
WATERS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SOUTHERLY WINDS SPORADICALLY GUSTING TO OVER 10 KT THIS
AFTERNOON.
* SLIGHT CHANCE FOR SHRA TUESDAY MORNING...WITH A CHANCE FOR TSRA
IN THE WESTERN TRACON AREA.
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE IS BEGINNING TO PULL AWAY WITH SOUTHERLY WINDS
ENCOMPASSING THE AREA. THE WIND DIRECTION AT CHICAGOLAND TAF
SITES HAS AND LIKELY WILL CONTINUE TO BE SOMEWHAT VARIABLE BETWEEN
SOUTHWEST AND SOUTHEAST. WHILE ORD AND MDW OBSERVATIONS HAVE
INDICATED A FEW GUSTS IN EXCESS OF 10 KT...BELIEVE THAT SUCH GUSTS
WILL BE INFREQUENT BASED ON THE ATMOSPHERIC PROFILE THIS
AFTERNOON. PER OBSERVATIONAL TRENDS...THE LAKE BREEZE LOOKS TO
VERY LIKELY STAY EAST OF ORD AND MDW. THE SYNOPTIC WIND WILL
LIKELY STILL OFFER ENOUGH OF A SOUTHEAST COMPONENT TO TURN THE
WINDS SLIGHTLY EAST OF SOUTH FROM TIME TO TIME THIS
AFTERNOON...BUT AGAIN SPEEDS SHOULD BE 6-10 KT MUCH OF THE TIME.
THUNDERSTORMS OVER WESTERN IA HAD DIFFICULTLY EVOLVING EASTWARD
THIS MORNING. AS AN UPPER LEVEL DISTURBANCE MOVES INTO THIS AREA
AND ADVANCED EAST...IT SHOULD HELP SHOWERS AND STORMS TO DO THE
SAME. AN UPTICK IN COVERAGE IS EXPECTED THIS EVE ACROSS EASTERN IA
AND POSSIBLY INTO NORTHWESTERN/WESTERN IL AS THE NIGHT PROGRESSES.
THE ATMOSPHERE FAVORS ANY ORGANIZED AREA OF SHOWERS AND STORMS TO
MOVE SOUTHEAST. RIGHT NOW ITS DIFFICULT TO SAY IF SHOWERS WILL
REMAIN WEST OF CHICAGOLAND SITES TUESDAY MORNING...HOWEVER THERE
IS GREATER CONFIDENCE THAT TSRA WILL STAY WEST/SOUTHWEST THROUGH
TUESDAY MORNING.
A POTENTIALLY ACTIVE AND IMPACTING PERIOD TO AVIATION WEATHER AT
AREA TAF SITES APPEARS TO BE SHAPING UP LATE TUESDAY NIGHT THROUGH
WEDNESDAY WITH A PROBABLE PERIOD OR PERIODS OF STORMS...GUSTY
SOUTHERLY WINDS...AND POTENTIALLY LOW CLOUDS WEDNESDAY MORNING.
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM THAT WINDS WILL NOT BECOME SOUTHEAST AND FREQUENTLY
GREATER THAN 10 KT.
* MEDIUM IN SHRA REMAINING WEST OF THE AIRFIELDS TUESDAY MORNING.
HIGH THAT TSRA WILL REMAIN WEST OF THE AIRFIELDS TUESDAY MORNING.
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 18Z...
TUESDAY NIGHT...CHC SHRA/TSRA INCREASING OVERNIGHT. SOUTHERLY
WINDS INCREASING WITH 40 KT FLOW AROUND 1000-1500 FT.
WEDNESDAY...SHRA/TSRA LIKELY ESPECIALLY IN THE MORNING. GUSTY
SOUTHERLY WINDS...AT TIMES TO 25 KT AND POSSIBLY 30 KT. MAINLY
VFR...BUT PATCHY IFR IN STRONGER SHRA/TSRA.
THURSDAY THROUGH SUNDAY...MAINLY VFR.
MTF
&&
.MARINE...
156 PM CDT
THE MAIN FORECAST CONCERNS CENTER AROUND A SIGNIFICANT STORM SYSTEM
EXPECTED TO IMPACT THE GREAT LAKES WEDNESDAY THROUGH THURSDAY.
SOUTHERLY WINDS ARE EXPECTED TO INCREASE RAPIDLY AROUND OR SHORTLY
AFTER DAYBREAK WEDNESDAY AS A STRENGTHENING AREA OF LOW PRESSURE
MOVES FROM IOWA INTO SOUTHWESTERN WISCONSIN. SOUTHERLY GALES OF 35
TO 40 KT ARE PROBABLE BY MID TO LATE MORNING...ESPECIALLY ACROSS THE
SOUTHERN HALF TO 2/3RDS OF THE LAKE...AND THESE STRONG WINDS LOOK TO
CONTINUE THROUGH WEDNESDAY AFTERNOON. THE LOW IS THEN EXPECTED TO
SHIFT SOMEWHERE ACROSS THE NORTHERN PORTION OF THE LAKE BY WEDNESDAY
EVENING. THIS COULD RESULT IN A SHORT PERIOD OF LIGHT AND VARIABLE
WINDS ACROSS NORTHERN SECTIONS OF THE LAKE EARLY WEDNESDAY EVENING.
HOWEVER...ONCE THIS LOW SHIFTS EAST OF THE LAKE BY LATER WEDNESDAY
EVENING...A STRONG COLD FRONT WILL PUSH OVER THE LAKE...WITH A
PERIOD OF NORTHWESTERLY GALES LOOKING LIKE A DECENT BET ACROSS MOST
OF THE LAKE INTO EARLY THURSDAY.
THE WINDS WILL GRADUALLY ABATE SOME INTO THE LATER PORTION OF THE
WEEK AS HIGH PRESSURE BUILDS IN ACROSS THE PLAINS AND UPPER
MIDWEST. HOWEVER...THE NORTHERLY FETCH WILL LIKELY CONTINUE TO
PRODUCE SOME HIGHER 4 + FOOT WAVES THROUGH FRIDAY.
AS FOR HEADLINES...WE HAVE ISSUED A GALE WATCH FOR THE SOUTHERN
2/3RDS OF THE OPEN WATERS FROM 14 UTC WED THROUGH 15 UTC THURS
AND FOR THE NORTHERN PORTION OF THE LAKE FROM 03 UTC THURS THROUGH
15 UTC THURS. HOWEVER...AT THIS TIME I HAVE OPTED TO LEAVE THE
ILLINOIS AND INDIANA NEAR SHORES OUT OF THE GALE WATCH DUE TO THE
OFFSHORE COMPONENT OF THE FLOW AND THEIR PROXIMITY TO THE SURFACE LOW.
HOWEVER...GALE FORCE GUSTS ARE CERTAINLY POSSIBLE IN THE NEAR SHORES
AS WELL...AND THIS MAY NEED TO BE ADDED TO THE WATCH IN FUTURE
FORECAST UPDATES. AT THE VERY LEAST...A HIGH END SMALL CRAFT
ADVISORY WITH WINDS TO 30 KT WILL LIKELY BE NEEDED FOR THE NEAR
SHORE WATERS FOR WEDNESDAY THROUGH THE END OF THE WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
101 PM CDT Mon Sep 8 2014
.UPDATE...
ISSUED AT 1027 AM CDT MON SEP 8 2014
Only minor updates made to tweak high temperatures up a degree or
two for today. Surface ridging gradually shifting through eastern
Illinois late this morning will result in a weak south return flow
in west central and central IL today. This should allow highs to
climb around 80 degrees this afternoon. Upstream surface
observations and the 12z ILX sounding indicate there is still a lot
of dry air in the lower atmosphere, so any cloud cover should
mainly be restricted to high clouds from the MCS in Iowa.
Late tonight, some of the short range models are indicating the
development of another MCS in Iowa. The remnants of this may spill
over into west central IL toward daybreak...and possibly just west
of the I-55 corridor Tuesday morning before dissipating.
Confidence in the eastward extent of this convection is not very
high since there is quite a bit of short term model discrepancy
and due to the presence of low level dry air that will need to be
overcome.
&&
.SHORT TERM...(Today)
ISSUED AT 309 AM CDT MON SEP 8 2014
High pressure currently extending from New England to the Southern
Plains will provide another pleasant day across central Illinois
today. Despite cool early morning lows in the lower to middle 50s,
dry airmass will heat quite efficiently thanks to abundant
sunshine. With subsidence inversion lowering slightly from
yesterday, mixing will only take place up to around 900mb today.
This will result in similar high temperatures to yesterday, perhaps
a degree or two warmer in the upper 70s to around 80 degrees.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 309 AM CDT MON SEP 8 2014
Short-wave trough evident on 07z/2am water vapor imagery over
eastern South Dakota will track eastward tonight, triggering a
cluster of showers and thunderstorms along the nose of a 30-35kt LLJ
oriented into northern Iowa. This convection will track E/SE toward
Illinois, but will encounter an unfavorably dry/stable airmass east
of the Mississippi River. As a result, am expecting a distinct
diminishing trend as storms push into west-central Illinois late
tonight into Tuesday morning. Will continue with chance PoPs across
the Illinois River Valley after midnight, with dry conditions
expected through the entire night further east across east-central
and southeast Illinois. Diurnal weakening trend will result in
complete dissipation of thunderstorm cluster Tuesday morning,
although widely scattered showers/thunder could re-develop along
outflow boundary during the afternoon. As such, will carry low
chance PoPs along/west of I-55, with dry weather further east. Will
be a warm day as well, with high temperatures ranging from around 80
degrees northwest of the Illinois River where cloud debris will hold
readings down a bit, to the middle 80s along/south of I-70.
Main weather story is still on target for Tuesday night through
Wednesday night, as a vigorous upper-level trough digs southeastward
out of the Northern Rockies and an unseasonably strong surface low
develops over western Kansas on Tuesday. Models are in good
agreement that the low will deepen to around 992mb as it tracks to
Lake Superior by Wednesday evening. Ahead of the low, an increasing
W/SW LLJ will bring copious amounts of moisture into central
Illinois Tuesday night into Wednesday, with all model solutions
showing precipitable water values climbing to around 2.25. Trailing
cold front is expected to push into the KILX CWA on Wednesday,
accompanied by widespread showers and thunderstorms. Severe weather
will be possible Wednesday afternoon and evening as the front
progresses through the region. Main question will be degree of
destabilization, as models are indicating dew points in the lower 70s
and resulting CAPE values of 1500 to 2500J/kg. If this level of
instability is realized, storms will quickly organize along/ahead of
the front thanks to 0-6km bulk shear values increasing to between 30
and 40kt. Primary severe weather threats will be damaging wind
gusts and high rainfall rates potentially leading to localized flash
flooding. Have increased PoPs to categorical across the NW CWA late
Tuesday night and across the board on Wednesday.
Once front sinks into the Ohio River Valley, a cooler/drier airmass
will arrive on Thursday. Due to strong CAA, high temperatures will
drop into the upper 60s and lower 70s. Models have come into better
agreement concerning the timing of the trailing 500mb trough axis,
with all solutions taking it across central Illinois on Friday.
Despite dry airmass, strong upper dynamics and steep lapse rates
will be enough to trigger clouds and perhaps a few light showers on
Friday. After that, cool and dry weather will be the rule over the
weekend, with highs mainly in the 60s and overnight lows dropping
into the 40s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 100 PM CDT MON SEP 8 2014
VFR conditions can generally be expected the next 24 hours in
central and eastern IL. A surface high pressure ridge will remain
over eastern IL into this evening with a southerly return flow
developing in central IL. However, the biggest question will be
how much return flow of low level moisture occurs, especially west
of I-55. Most of the shorter range models are depicting the
development of another MCS in Iowa overnight. However, they differ
on where the remnants may track. The HRRR seems to be too far
north with its rainfall, while the NAM and RAP keep the bulk of
the thunderstorms in SE Iowa and west central IL closer to the
lower level theta-e ridge.
With the best low level moisture advection/moisture transport
expected to be near the MS River and the forecast of Corfidi
vectors to be pointing toward the southeast, will only put a
mention of VCTS in the forecast for KPIA, with the possibility of
a VCSH along I-55 from KBMI-KSPI Tuesday morning after daybreak.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
920 PM CDT TUE SEP 9 2014
.UPDATE...
ISSUED AT 905 PM CDT TUE SEP 9 2014
REALLY THE ONLY CONCERN TONIGHT IS HEAVY RAIN AND FLOODING AS SEVERE
THREAT VERY LOW WITH SATURATED SOUNDING AND LIMITED SUB CLOUD
BUOYANCY.
LINEAR MCS CONTINUES SAGGING S/SE INTO LOW LEVEL MOIST AXIS AND IS
INTERCEPTING MAIN LOW LEVEL JET AND MOISTURE TRANSPORT FEED.
MUCH OF CONVECTION AND HEAVY RAIN CONCERNS WILL EXIST NEAR TO SOUTH
OF I-80 REST OF EVE... WITH STRATIFYING PCPN SHIELD ACROSS NORTH.
CONCERNS EXIST THAT THE LONGER THIS CONVECTION CONTINUES TO OUR
SOUTH TONIGHT INTERRUPTING FOCUS OF LOW LEVEL JET AND MOISTURE
FEED...THE MORE UNCERTAINTY EXISTS WITH HEAVY RAIN THREAT
DEVELOPING ACROSS NORTHERN CWA... ALTHOUGH CANNOT BE RULED OUT IF
STORMS CAN WEAKEN TO OUR SOUTH ALLOWING LOW LEVEL JET TO REFOCUS
FURTHER NORTH WITH NORTHWARD LIFTING WARM FRONT. HAVE TRENDED
FORECASTS TOWARD HEAVIER RAINS TONIGHT ACROSS SOUTHERN HALF OF THE
CWA... BUT WILL MAINTAIN FLASH FLOOD WATCH ALL AREAS DUE TO UNCERTAINTY.
&&
.SYNOPSIS...
ISSUED AT 330 PM CDT TUE SEP 9 2014
LOW PRESSURE OVER EXTREME SOUTHEAST CO HAD A WARM FRONT EXTENDED
INTO NORTHERN MO INTO SOUTHERN IL. TEMPERATURES TO THE SOUTH OF
THE FRONT WERE WELL IN THE 80S TO MID 90S WITH DEWPOINTS IN THE
LOWER TO MID 70S. SBCAPES OF 4000 J/KG WERE OCCURRING IN WESTERN
MO. TO THE NORTH OF THE FRONT IN THE RAIN COOLED AIR READINGS WERE
ONLY IN THE UPPER 60S TO UPPER 70S. THE BEST PRESSURE FALLS WERE
LOCATED IN WESTERN KS. PRECIPITABLE WATERS WERE AS HIGH AS 1.9 INCHES
IN NORTHERN MO.
DOPPLER RADAR CONTINUED TO SHOW FESTERING SHOWERS AND A FEW
THUNDERSTORMS FROM EASTERN NEB INTO SOUTHEAST IA AND CENTRAL IL
WITH WARM AIR ADVECTION INTO THE AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT TUE SEP 9 2014
HEADLINES...NOW THAT MUCH OF THE AREA HAS SATURATED SOILS THE
FLASH FLOOD WATCH WILL CONTINUE TONIGHT INTO WEDNESDAY MORNING
FOR THE ENTIRE CWA.
TONIGHT...ADDITIONAL RAINFALL OF 1 TO 3 INCHES APPEAR LIKELY. SOME
LOCATIONS MAY RECEIVE 4 TO 6 INCHES...ESPECIALLY IN ANY TRAINING/REPEATING
STORMS. THIS AMOUNT OF RAIN ON VERY SATURATED SOILS WOULD CAUSE SERIOUS
FLASH FLOODING. PRECIPITABLE WATERS WILL BE AT NEAR RECORD VALUES
FOR SEPTEMBER...ABOUT 2.2 INCHES. THIS IS DUE TO RICH GULF MOISTURE
COMBINED WITH MOISTURE FROM THE REMNANTS OF WHAT WAS MAJOR PACIFIC
HURRICANE NORBERT. RAINFALL RATES WILL BE EXTREMELY HIGH SO VERY
TORRENTIAL RAINS WILL ACCOMPANY THESE STORMS. CONFIDENCE IS VERY
HIGH FOR THIS FLASH FLOOD EVENT BUT IS LOWER FOR THE SEVERE THREAT.
THERE IS THE POTENTIAL FOR LOCALIZED WET MICROBURSTS DUE TO THE
VERY SATURATED ATMOSPHERE BUT ANY HAIL SHOULD REMAIN BELOW SEVERE
LEVELS. I AM CONCERNED FOR THE POTENTIAL FOR AN ISOLATED TORNADO
OR TWO ON ANY BOUNDARY AS THE DEEP LAYER SHEAR BECOMES VERY STRONG
EVEN WELL AFTER DARK AS THE SURFACE LOW DEEPENS AND TRACKS TOWARDS
LA CROSSE WI BY 12Z WEDNESDAY. THE HRRR MESO MODEL SUGGESTS ACTIVITY
INCREASING IN OUR SOUTHERN CWA LATE THIS AFTERNOON OR TOWARDS EVENING
THEN SPREADING NORTHEAST AS THE EVENING PROGRESSES...WITH WIDESPREAD
STORMS THEN OCCURRING OVERNIGHT. SOME OF THE STRONGER STORMS WILL
ALSO PRODUCE FREQUENT TO CONTINUOUS DANGEROUS LIGHTNING. MINIMUM
TEMPERATURES WILL BE IN THE MID 60S TO LOWER 70S.
WEDNESDAY...DEEPENING CYCLONE WILL TRACK INTO THE GREAT LAKES REGION
SENDING A STRONG COLD FRONT INTO OUR WESTERN CWA IN THE MORNING AND
OUR EASTERN CWA IN THE EARLY AFTERNOON. THE THUNDERSTORMS WILL GRADUALLY
DIMINISH AND SHIFT TO THE EAST OF THE CWA WITH THE FRONT. THE SEVERE
THREAT APPEARS TO BE FARTHER TO THE EAST THAN EARLIER THOUGHT AND SPC
HAS THE SLIGHT RISK ONLY IN OUR FAR SOUTHEAST COUNTIES...BUT THIS WILL
DEPEND ON CLOUD COVER AND AMOUNT OF INSTABILITY. MAXIMUM TEMPERATURES
SHOULD RANGE FROM THE UPPER 60S AT INDEPENDENCE IA TO THE UPPER 70S
IN OUR FAR EAST/SOUTHEAST COUNTIES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH NEXT TUESDAY)
ISSUED AT 330 PM CDT TUE SEP 9 2014
WEDNESDAY NIGHT THROUGH FRIDAY...SEASONABLY STRONG RIDGE STILL ON
TRACK TO DUMP DOWN THE PLAINS AND UPPER MS RVR VALLEY THIS PERIOD.
EXPECT MOST POST-FRONTAL RAINS TO BE OUT OF THE CWA AT START OF THE
PERIOD...WITH JUST DEEPENING LLVL NORTHERLY FLOW COOL ADVECTING AND
SCORING OUT THE CLOUD COVER EVENTUALLY BY THU MORNING. EVEN IF CLOUD
COVER HOLDS ON TIL DAYLIGHT...LOWS TO BE ADVECTED DOWN INTO THE 40S
IN MOST OF THE CWA. INCOMING CANADIAN AIR TO WARM ONLY INTO THE 60S
THU EVEN WITH SOME SUNSHINE...WITH A QUICK DROP OFF AFTER SUNSET THU
EVENING INTO THE 40S BEFORE INCREASING CLOUDS AHEAD OF THE NEXT
SYSTEM TOWARD FRI MORNING HALTS TEMP DROP OFF. STILL SOME PHASING
ISSUES TO BE HAMMERED OUT...BUT LATEST RUN MEDIUM RANGE SOLUTIONS
SUGGEST SOME TYPE OF WAVE/POSSIBLY RATHER VIGOROUS...TO ROLL ACRS
THE REGION ON FRI. THIS SYSTEM WILL NOT HAVE NEAR THE MOISTURE
SOURCE OR THERMODYNAMICS TO WORK WITH AS THE CURRENT SYSTEM...BUT
STILL SHOULD INDUCE A RAIN SHIELD THAT WILL OVERSPREAD MOST OF THE
CWA FROM WEST TO EAST AS FRI PROGRESSES. CLOUD COVER AND PRECIP TO
KEEP A LID ON TEMPS WITH MOST AREAS HELD IN THE 50S OR EVEN UPPER 40S
AND NORTH WINDS MAKING FOR A RAW DAY. CURRENT INDICATIONS SUGGEST
MOST AREAS TO GET FROM 0.10 UP CLOSE TO HALF AN INCH BY THE TIME THE
RAIN PULLS OUT FRI EVENING. MODELS STILL VARYING ON PRECIP AND CLOUD
COVER EXIT TIMING LATER FRI NIGHT...BUT WILL JUST KEEP PRECIP IN THE
EVENING FOR NOW. POST-WAVE SUBSIDENCE MAY MAKE FOR A LATE NIGHT
CLEAR OUT...BUT SOME CHANCE FOR SUBSIDENCE INVERSION TO TRAP CLOUDS
INTO SAT MORNING LIMITING FRI NIGHT/SAT MORNING COLD POTENTIAL. THE
GFS CONTINUES TO BE THE COLD MODEL WITH SOME UPPER 30S IN THE
NORTHWESTERN THIRD OF THE DVN CWA AND LOWER 40S ELSEWHERE. THE ECMWF
MORE IN THE WAY OF LOW TO MID 40S BUT KEEPS THE CLOUD COVER AND SOME
MIXING SFC WINDS GOING INTO SAT MORNING. WITH EXTENT OF INCOMING
UNSEASONABLY COLD AIRMASS...FEEL WITH ANY KIND OF CLEAR OUT/PARTIAL
CLEARING AND SFC WIND DROP OFF UNDER 10 MPH LATE FRI NIGHT...THE
COOLER GFS WILL PREVAIL.
SATURDAY AND SUNDAY...HIGHS ONLY RECOVERING INTO THE UPPER 50S TO
MID 60S SAT UNDER WEAK MIXING REGIME OF CANADIAN HIGH PRESSURE...
THEN HOW COLD TO GO SAT NIGHT THE CHALLENGE. IF LLVL RETURN FLOW
DOES NOT MATERIALIZE IN TIME AND THE SFC RIDGE PERSISTS LONGER
BEFORE EASTWARD MIGRATION...SAT NIGHT MAY BE THE COOLER OF THE TWO
COLD WINDOW NIGHTS BEING WATCHED RIGHT NOW...MORE IDEAL RADIATIONAL
COOLING PARAMETERS IN LINE POSSIBLY. MORE WIDESPREAD MID TO UPPER 30S
POSSIBLE ESPECIALLY EAST OF THE MS RVR CLOSER TO RIDGE CENTER. WAA
ON BACK SIDE OF RIDGE COMPLEX MAY GENERATE SOME ELEVATED SHOWERS
INTO THE WESTERN CWA BY LAT SUNDAY NIGHT...BUT CONFIDENCE LOW ON
THAT SCENARIO.
MONDAY THROUGH NEXT TUESDAY...NEXT WAVE WILL LOOK TO SHEAR ACRS THE
UPPER MIDWEST SOMETIME THIS PERIOD FOR THE NEXT RAIN CHANCE...WITH
THE 12Z RUN ECMWF MORE PHASED AN ORGANIZED WITH THIS SYSTEM MON
NIGHT INTO TUE FOR MORE SIGNIFICANT PRECIP AS OPPOSED TO THE GFS. ..12..
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 550 PM CDT TUE SEP 9 2014
CONDITIONS TO DETERIORATE TO MVFR/OCNL IFR AS SHOWERS AND STORMS BECOME
WIDESPREAD LATER THIS EVE THROUGH EARLY WED AM AHEAD OF A STRONG
COLD FRONT. STORMS WILL BRING PERIODS OF VERY HEAVY RAIN... AND A FEW
MAY PRODUCE GUSTY WINDS AND HAIL. PCPN WILL DIMINISH IN COVERAGE AND
INTENSITY BY MID TO LATE WED AM... AS THE COLD FRONT BEGINS TO MOVE
INTO THE AREA. THE FRONT WILL LIKELY COME THROUGH THE TERMINALS BETWEEN
16Z-20Z BRINGING A WIND SHIFT TO THE NORTHWEST AROUND 10-15 KTS
WITH GUSTS POSSIBLE. SOME LOWER CIGS INTO IFR POSSIBLE ALONG AND BEHIND
THE FRONT FOR A TIME.
&&
.HYDROLOGY...
THE RIVER WATCH WILL BE ON THROUGH MID WEEK. AFTER LAST NIGHT/S AND
THIS MORNINGS RAINS...ANOTHER 1-4 INCHES TONIGHT INTO WED MORNING
WILL DEFINITELY PRODUCE SOME FLOODING ON AREA TRIBUTARIES...DEPENDING
ON HOW WIDESPREAD THE ADDITIONAL HEAVY RAIN WILL FALL IN THE LOCAL
AREA OF CONCERN. RIVER BASINS TO WATCH FOR FLOODING POTENTIAL ON SOME
OF THE FCST POINTS FROM WED THROUGH FRI MORNING ARE THE SKUNK...
CEDAR...IOWA...WAPSI...ENGLISH...AND DES MOINES RIVERS. THE
MAQUOKETA MAY GET CLOSE. IF NOT FLOODING THEN SIGNIFICANT WITHIN BANK
RISES TO OCCUR. ..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLASH FLOOD WATCH UNTIL 7 AM CDT WEDNESDAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...FLASH FLOOD WATCH UNTIL 9 AM CDT WEDNESDAY FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLASH FLOOD WATCH UNTIL 7 AM CDT WEDNESDAY FOR CLARK-SCOTLAND.
&&
$$
UPDATE...05
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...12
AVIATION...05
HYDROLOGY...12
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
703 PM CDT TUE SEP 9 2014
...UPDATED FOR AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 204 PM CDT TUE SEP 9 2014
LATEST RAP 400MB POTENTIAL VORTICITY APPEARS TO HAVE A DECENT
HANDLE WITH AN UPPER LEVEL DISTURBANCE THAT WAS CROSSING THE
COLORADO ROCKIES AT 18Z. GIVEN THE 18Z VERIFICATION WILL STAY
CLOSE TO THE RAP ON TIMING OF THIS UPPER LEVEL FEATURE AS IT
CROSSES EASTERN COLORADO AND WESTERN KANSAS LATER THIS EVENING.
GIVEN LATE DAY INSTABILITY AND LOCATION OF LOW LEVEL FORCING AHEAD
OF THIS UPPER LEVEL TROUGH NEAR A SURFACE BOUNDARY THAT WILL
EXTEND FROM SOUTHEAST COLORADO INTO NORTH CENTRAL KANSAS THERE
WILL BE A CHANCE FOR SCATTERED THUNDERSTORMS LATE THIS AFTERNOON
ACROSS NORTH CENTRAL KANSAS AND PORTIONS OF WEST KANSAS. BASED ON
THE 21Z TUESDAY AND 00Z WEDNESDAY CAPE AND 0-6KM SHEAR FROM THE
NAM A FEW STORMS LATE TODAY MAY BE SEVERE WITH THE AREA MORE
FAVORABLE FOR HAIL GOLF BALL SIZE OR LARGER ALONG WITH WIND GUST
IN EXCESS OF 60 MPH WILL BE ALONG AND NORTH OF A DIGHTON AND
LARNED LINE.
THUNDERSTORMS WILL THEN INCREASE IN AREAL COVERAGE EARLY TONIGHT
AS THE UPPER LEVEL DISTURBANCE CROSSES THE CENTRAL HIGH PLAINS AND
A SURFACE BOUNDARY MOVES ACROSS SOUTHWEST KANSAS. THE AREA THAT
WILL BE MORE FAVORABLE FOR WIDESPREAD THUNDERSTORMS EARLY TONIGHT
WILL BE ALONG AND NORTH OF A 700MB +10C TO +13C BAROCLINIC ZONE.
GIVEN THE 12Z NAM AND 12Z GFS THIS FAVORABLE AREA WILL BE
NORTHEAST OF A SYRACUSE TO DODGE CITY THE PRATT LINE. ALSO GIVEN
THE HIGH PRECIPITABLE WATER VALUES PERIODS THERE WILL BE A CHANCE
FOR PERIODS OF HEAVY RAIN IN THIS AREA AS WELL.
BUFR SOUNDINGS INDICATING WINDS NEAR THE SURFACE BEHIND THE COLD
FRONT WILL RANGE FROM 20 TO 30 KNOTS AS THE LOWER LEVELS BEGIN TO
SATURATE. BY 12Z WEDNESDAY THE DEPTH OF THIS LOW LEVEL MOISTURE
APPROACHES 3000FT WHICH SUPPORTS INSERTING A SLIGHT CHANCE FOR
LIGHT DRIZZLE FOR SEVERAL HOURS EARLY WEDNESDAY MORNING. BY LATE
MORNING THIS LOW LEVEL MOISTURE WILL BEGIN TO ERODE FROM SOUTHWEST
NORTHEAST AND GIVEN SOME AFTERNOON SUNSHINE ACROSS SOUTHWEST AND
SOUTH CENTRAL KANSAS THE HIGHS ARE EXPECTED TO CLIMB BACK INTO THE
MID 70S BASED ON THE 00Z THURSDAY 850MB TEMPERATURES. FURTHER
NORTH, NEAR THE INTERSTATE 70 CORRIDOR THE CLOUDS AND 850MB
TEMPERATURES AT 00Z THURSDAY SUGGEST HIGHS ON IN THE UPPER 60S TO
NEAR 70.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 313 PM CDT TUE SEP 9 2014
THE TREND WILL BE FOR COOLER AND WETTER IN THE VERY EARLY PERIOD
OF THE LONG TERM FORECAST. THE PERIOD FROM WEDNESDAY INTO THE
BEGINNING OF THE WEEKEND WILL THEN BE FOLLOWED BY A MODERATE
REBOUND BACK TOWARD THE 80S BY THE MIDDLE OF NEXT WEEK.
ALL THREE MODELS, THE ECMWF, GFS AND NAM INDICATED PRECIPITATION
ALONG A STRONG FRONTOGENETIC ZONE ACROSS CENTRAL AND FAR WESTERN
KANSAS INTO SOUTHEAST COLORADO FROM LATE THURSDAY NIGHT AND
SPREADING EAST OVER CENTRAL KANSAS FRIDAY MORNING. SOME VARIABILITY
IS EXPECTED AS THE BETTER FORCING IN THE MID LEVELS IS NOT EXPECTED
TO SLIDE ALL THE WAY THROUGH THE CWA INTO OKLAHOMA, HENCE A BAND OF
HIGHER RAIN AMOUNTS COULD FALL SOMEWHERE FROM THE HIGHWAY 54
CORRIDOR NORTHWARD AS THE NAM SUGGESTS. OTHER LOCATIONS SHOULD STILL
GET SOME, BUT GENERALLY MUCH LIGHTER PRECIPITATION AMOUNTS OF A FEW
HUNDREDTHS AS THE SECONDARY FRONTAL BOUNDARY MOVES THROUGH THE
REGION IN THE FORM OF SCATTERED SHOWERS IF NOT A PERIOD OF RAIN. OF
MUCH LONGER DURATION AND IMPACT WILL BE THE WIDESPREAD STRATUS
THROUGH THE AREA, INHIBITING INSOLATION AND ENHANCING COLD
ADVECTION. THE NUMEROUS MODELS AND BLEND SOLUTIONS STRONGLY SUPPORTS
LOW 50S ACROSS MUCH OF THE AREA FOR A HIGH TEMPERATURES ON FRIDAYS.
TEMPERATURES THIS COOL WILL REPRESENT ONLY A FEW DEGREES ABOVE
RECORD MIN-MAXIMUM TEMPERATURES FOR SEPTEMBER 12TH AT LEAST LOCALLY
AT DDC.
A WARMING TEND WILL BE SLOW THROUGH THE WEEKEND PERIOD. THE MEAN
LAYER WILL RETURN TO GENERALLY ZONAL PATTERN BY SUNDAY AFTER THE
LARGE WAVE EXISTS. THE NEXT WAVE WILL NOT BECOME A POTENTIAL IMPACT
UNTIL AROUND LATE SUNDAY OR MONDAY. THE PATTERN SUGGEST SOUTHWEST
KANSAS COULD BE SPLIT AS FAR AS UPPER DYNAMIC FORCING GOES, WITH
POSSIBLE MCS ACTIVITY TO THE NORTH IN THE DAKOTAS AND NEBRASKA AND
SHORTWAVE ENERGY IN THE PANHANDLES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 659 PM CDT TUE SEP 9 2014
ASIDE FROM SCATTERED THUNDERSTORMS WITH BRIEF STRONG WINDS THAT
COULD AFFECT THE TERMINALS THROUGH THE EVENING, VFR CONDITIONS CAN
BE EXPECTED, WITH SOUTH WINDS BECOMING NORTH BETWEEN 04 AND 08Z AFTER
AS THE COLD FRONT PASSES. MVFR CIGS WILL LIKELY DEVELOP TOWARD
MORNING WITH DIURNAL COOLING AND COLD ADVECTION. BUT WITH DAYTIME
HEATING, SKIES SHOULD BECOME PARTLY SUNNY AFTER 16Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 63 73 49 65 / 40 10 0 10
GCK 62 73 49 63 / 50 20 10 10
EHA 62 75 52 69 / 20 10 10 10
LBL 64 76 51 67 / 20 10 0 10
HYS 62 68 45 62 / 70 20 0 10
P28 70 78 53 71 / 30 10 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS JACKSON KY
259 PM EDT MON SEP 8 2014
.UPDATE...
ISSUED AT 1208 PM EDT MON SEP 8 2014
FOG HAS FINALLY LIFTED. STRATUS DECK OVER PORTIONS OF THE AREA WILL
CONTINUE TO RISE AND BREAK UP FOR GENERALLY PARTLY CLOUDY AFTERNOON
SKIES. STILL CAN NOT RULE OUT SOME ISOLD TO SCT CONVECTION THIS
AFTERNOON...THOUGH WITH TIME THOUGHTS ARE LEANING INCREASINGLY
TOWARDS MORE ISOLD COVERAGE AND MAINLY IN OUR SOUTH AND FAR EAST.
UPDATE ISSUED AT 1018 AM EDT MON SEP 8 2014
FOR THIS MORNINGS UPDATE BROUGHT GRIDS IN LINE WITH HOURLY OBS.
STUBBORN FOG AND LOW STRATUS IS LINGERING ACROSS THE AREA THIS
MORNING...MAINLY DUE TO NORTHEAST WINDS ACROSS MUCH OF THE CWA WHICH
DO TEND TO KEEP LOW STRATUS IN PLACE. HOWEVER STILL EXPECT A GRADUAL
LIFTING AND EROSION OF THE FOG AND STRATUS ONCE EFFECTS OF SUN ARE
ABLE TO BURN THROUGH TO THE SFC. A WEAK SOUTHEASTERN DOWN SLOPE FLOW
APPEARS TO BE KEEPING THE FOG AND STRATUS AT BAY ACROSS OUR HIGHER
TERRAIN IN THE SOUTHEAST.
MID LEVEL SHORT WAVE CONTINUES TO ROLL UP INTO THE MID OHIO VALLEY
THIS MORNING. THIS FEATURE IS FAIRLY VISIBLE IN WATER VAPOR IMAGES.
WHILE CAN NOT TOTALLY RULE OUT SOME SHOWER AND THUNDERSTORM ACTIVITY
THROUGH THE DAY CONFIDENCE IS WANING CONSIDERABLY. THE RAP...AND TO A
LESSER EXTENT GFS FCST SOUNDINGS ARE SHOWING A WEAK CAP ACROSS MUCH
OF THE AREA. THIS IS SOMEWHAT IN LINE WITH ILN/OHX MORNING SOUNDINGS
THOUGH BEING GENERALLY OUTSIDE OF THE INFLUENCE OF THE SHORTWAVE
THEY MAY NOT BE A GOOD REPRESENTATION OF THE PROFILE ACROSS OUR AREA.
DISCOUNTED THE NAM/S SOUNDING AS IN TYPICAL FASHION IT GREATLY
OVERDOES BOUNDARY LAYER MOISTURE AND CONSEQUENTLY BOUNDARY LAYER
INSTABILITY AND SOUNDING PARAMETERS. THE HRRR HAS TRENDED TOWARDS A
BIT LESS COVERAGE IN ACTIVITY AS WELL...AND INITIATES A BIT LATER IN
THE DAY THAN PREVIOUS RUNS. DID DELAY DEVELOPMENT OF ACTIVITY UNTIL
LATE MORNING/EARLY AFTERNOON BUT IN GENERAL KEPT INHERITED ISOLD AND
SCT POPS FOR THE AFTERNOON TIME FRAME.
UPDATE ISSUED AT 730 AM EDT MON SEP 8 2014
TWEAKED THE GRIDS A BIT EARLY THIS MORNING TO FINE TUNE THE SKY COVER
AND T/TD PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM EDT MON SEP 8 2014
07Z SFC ANALYSIS SHOWS COOL AND DRY HIGH PRESSURE SPRAWLED OUT FROM
THE OHIO VALLEY THROUGH THE NEW ENGLAND STATES. GENERAL LOW PRESSURE
IS FOUND OVER THE DEEP SOUTH AND ALONG THE SOUTHEAST COAST. NOT FAR
FROM EAST KENTUCKY IS A STALLED FRONTAL BOUNDARY LURKING JUST TO THE
SOUTH. THIS HAS HELPED TO PREVENT THE DRY COMPONENT OF THE HIGH
PRESSURE FROM MAKING IT THROUGH ALL OF THE STATE AS DEW POINTS ALONG
THE TENNESSEE BORDER ARE IN THE LOW AND MID 60S WHILE MID AND UPPER
50S EXIST TO THE NORTH. THESE NORTHERN SPOTS ARE ALSO ENJOYING
TEMPERATURES DOWN INTO THE MIDDLE AND UPPER 50S...PARTICULARLY IN THE
VALLEYS WHERE MOSTLY CLEAR SKIES HAVE ALLOWED FOR DECENT RADIATIONAL
COOLING BELOW THE THERMAL INVERSION. MEANWHILE...RIDGES AND LOCATIONS
TO THE SOUTH WITH HIGHER DEW POINTS ARE SEEING TEMPERATURES A FEW
DEGREES MORE. A COUPLE LARGE PATCHES OF LOW CLOUDS ARE AFFECTING
SOUTHEAST KENTUCKY EARLY THIS MORNING HELPING TO DISRUPT THE FOG
FORMATION...THOUGH THERE WILL UNDOUBTEDLY BE PATCHY FOG...LOCALLY
DENSE...IN MANY VALLEY LOCATIONS GENERALLY CORRESPONDING TO THE
CLEAR SPOTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH ANOTHER POCKET OF ENERGY
ROLLING EAST THROUGH GENERALLY FLAT FLOW TODAY...HELPING TO LOWER
HEIGHTS LOCALLY AND BRING SOME EXTRA LIFT TO THE AREA. THIS MOVES
THROUGH BY EVENING WITH CONTINUED RELATIVELY FAST AND NEARLY ZONAL
FLOW INTO THE DAY TUESDAY. LATE IN THE SHORT TERM PORTION OF THE
FORECAST HEIGHTS WILL CLIMB A NOTCH AHEAD OF A LARGE AND DEEPENING
TROUGH OVER THE ROCKY MOUNTAIN AND HIGH PLAINS STATES. WITH THE MODEL
SIMILARITIES HAVE GONE MAINLY WITH A BLEND OF THE HRRR AND NAM12 FOR
WX SPECIFICS DURING THE FIRST 12-18 HOURS AND THEN THE 00Z
ECMWF/NAM12 THROUGH TUESDAY.
SENSIBLE WEATHER WILL FEATURE A CONTINUED COOL AND DRY DAY ACROSS THE
FAR NORTHWEST PARTS OF THE AREA WHILE TO THE SOUTHEAST THERE WILL BE
MUCH MORE CLOUD COVER ALONG WITH A THREAT FOR SHOWERS THROUGH
THE MORNING. BY MIDDAY THUNDER CHANCES WILL PICK UP OWING TO BUILDING
INSTABILITY AND THE NEARBY FRONT BEING ACTED UPON BY THE PASSING MID
LEVEL SHORT WAVE. THE PCPN THREAT AND SOME OF THE CLOUD COVER WILL
RETREAT TO THE EAST LATER TONIGHT WITH ANOTHER NIGHT OF MINOR RIDGE
TO VALLEY TEMPERATURE DIFFERENCES AMIDST A NW TO SE STRIATION IN
DEW POINTS. DUE TO THIS ANTICIPATE PATCHY VALLEY FOG AFTER MIDNIGHT
FOR MOST LOCATIONS...PARTICULARLY ONES THAT MANAGE TO SEE ANY RAIN
DURING THE DAY AND EVENING. TUESDAY WILL BE QUIET AND DRY...BUT A TAD
WARMER WHILE THE DEVELOPING LOW TO THE EAST STARTS TO LIFT NORTH
ALONG THE SOUTH EAST ATLANTIC SEABOARD.
STARTED WITH THE CONSSHORT FOR T...TD...AND WINDS...THROUGH THE
FIRST 24 HOURS FOLLOWED BY THE SUPERBLEND UNTIL 00Z WED. PER
USUAL...MADE MINOR ADJUSTMENTS FOR TERRAIN DIFFERENCES WITH TEMPS
TONIGHT. AS FOR POPS...ENDED UP CLOSER TO THE LOWER MAV GUIDANCE
TODAY AND SIMILAR TO A BLEND OF THE RATHER LOW NUMBERS THEREAFTER
THROUGH THE REMAINDER OF THE SHORT TERM FORECAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM EDT MON SEP 8 2014
THE MODELS REMAIN IN GOOD AGREEMENT IN THE LONG TERM...WITH A LARGE
RIDGE OF HIGH PRESSURE ALOFT INFLUENCING THE WEATHER OF EASTERN
KENTUCKY TO BEGIN THE PERIOD. DRY WEATHER SHOULD BE ON TAP TUESDAY
NIGHT INTO EARLY WEDNESDAY AFTERNOON AS HIGH PRESSURE REMAINS IN
CONTROL. HOWEVER...THIS UPPER RIDGE WILL BE DISPLACED AS DEEP AREA
OF LOW PRESSURE...BOTH ALOFT AND AT THE SURFACE...COMES TOGETHER
OVER THE NORTHERN PLAINS AND BEGINS TO PUSH ACROSS THE NORTHERN
MISSISSIPPI VALLEY ON WEDNESDAY. THE SURFACE COLD FRONT ASSOCIATED
WITH THIS POTENT SYSTEM WILL BRING UNSETTLED WEATHER TO THE AREA
WEDNESDAY NIGHT AND THURSDAY. THE PRIMARY CONCERN WITH THIS WEATHER
SYSTEM WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL. THE MODELS
HAVE THE FRONT SLOWING DOWN AND NEARLY STALLING ACROSS OUR AREA ON
THURSDAY. SHOWERS AND STORMS ARE EXPECTED TO FIRE ALL ALONG THE
BOUNDARY AS LARGE AMOUNTS OF WARM MOIST AIR OFF THE GULF OF MEXICO
IS CARRIED NORTHWARD INTO THE BOUNDARY ON SOUTHERLY WINDS. THE BEST
CHANCE FOR RAIN LOOKS TO BE FROM LATE THURSDAY MORNING THROUGH LATE
THURSDAY AFTERNOON WHEN MOISTURE FLOW INTO THE FRONTAL ZONE IS AT
ITS PEAK. THERE WILL ALSO BE THE POTENTIAL FOR A FEW STRONG
THUNDERSTORMS ON THURSDAY AS THE FRONT MOVES THROUGH AS THERE WILL
BE STRONG DYNAMICS ASSOCIATED WITH THE BOUNDARY AND ITS PARENT UPPER
LEVEL SYSTEM. THUNDERSTORMS SHOULD THEN GIVE WAY TO RAIN SHOWER
BEHIND THE FRONT THURSDAY NIGHT AS THE COOLER AIR MOVES IN BEHIND
THE FRONT. THE FRONT IS EXPECTED TO EVENTUALLY CLEAR THE AREA LATE
THURSDAY NIGHT INTO EARLY FRIDAY MORNING...AS A LARGE RIDGE OF
CANADIAN HIGH PRESSURE PUSHES IT OFF TO OUR EAST. THIS AREA OF HIGH
PRESSURE WILL BRING A SIGNIFICANT PATTERN CHANGE TO THE MAJORITY OF
THE CONUS EAST OF THE ROCKY MOUNTAINS FROM FRIDAY ONWARD.
AFTER SLIGHTLY ABOVE NORMAL TEMPERATURES TUESDAY NIGHT AND
WEDNESDAY...A PERIOD OF UNSEASONABLE COOLING WILL BE OCCURRING.
HIGHS ON WEDNESDAY ARE EXPECTED TO TOP OUT IN THE MID TO UPPER 80S
AS SOUTHERLY WINDS BRING WARM MOIST AIR FROM THE GULF OF MEXICO INTO
THE REGION. ONCE THE FRONT ARRIVES ON THURSDAY...WIDESPREAD CLOUD
COVER AND PRECIPITATION WILL KEEP TEMPERATURES WELL BELOW
NORMAL...WITH HIGHS ONLY CLIMBING TO AROUND 80 BY THURSDAY
AFTERNOON. ONCE THE BOUNDARY HAS CLEARED THE AREA LATE THURSDAY
NIGHT...AN INVASION OF COOL AN DRY CANADIAN AIR WILL BEGIN TO OCCUR.
WITH WINDS SHIFTING TO THE NORTH BEHIND THE FRONT...TEMPERATURES
WILL BE HARD PRESSED TO CLIMB INTO THE MID 70S ON FRIDAY. THE COOL
WEATHER WILL THEN PERSIST THROUGH THE WEEKEND AS THE RIDGE OF HIGH
PRESSURE BECOMES MORE FIRMLY ESTABLISHED. HIGH TEMPERATURES ON
SATURDAY ARE EXPECTED TO ONLY CLIMB TO AROUND 70 WITH HIGHS ON
SUNDAY ONLY WARMING INTO THE LOW 70S. OVERNIGHT LOWS IN THE 50S ARE
EXPECTED AREA WIDE FRIDAY AND SATURDAY NIGHT AS THE COOL CANADIAN
AIR POURS INTO THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 259 PM EDT MON SEP 8 2014
PESKY LOW STRATUS AND FOG FINALLY LIFTED BY MID DAY. STILL SEEING
SOME INTERMITTENT MVFR CIGS AT A FEW PLACES BUT DAYTIME HEATING
SHOULD CONTINUE TO WORK ITS MAGIC LIFTING BASES JUST A BIT MORE
THROUGH THE AFTERNOON. RADAR DOES SHOW SOME SHOWER ACTIVITY KICKING
OFF. BUT DEVELOPMENT HAS BEEN SLOW. HIGH RES MODELS SUGGEST THAT A
CLUSTER OF STORMS MAY DEVELOP AND MOVE NORTHWARD OUT OF TN LATE THIS
AFTERNOON...AFFECTING MAINLY OUR SOUTHWESTERN TERMINALS. WILL WATCH
CLOSELY BUT CURRENT THINKING IS THAT ACTIVITY WILL GENERALLY LEAN
TOWARDS BEING MORE ISOLD OVER THOSE AREAS AND MORE SCATTERED IN
NATURE OVER OUR FAR SOUTH AND EAST. EXPECT FOG TO REDEVELOP ACROSS
THE AREA AGAIN TONIGHT...BUT NOT QUITE AS WIDESPREAD AND DENSE AS
THIS MORNING. WINDS WILL BE LIGHT THROUGH THE FORECAST PERIOD...
GENERALLY FROM THE WEST SOUTHWEST DURING DAYLIGHT HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
1208 PM EDT MON SEP 8 2014
.UPDATE...
ISSUED AT 1208 PM EDT MON SEP 8 2014
FOG HAS FINALLY LIFTED. STRATUS DECK OVER PORTIONS OF THE AREA WILL
CONTINUE TO RISE AND BREAK UP FOR GENERALLY PARTLY CLOUDY AFTERNOON
SKIES. STILL CAN NOT RULE OUT SOME ISOLD TO SCT CONVECTION THIS
AFTERNOON...THOUGH WITH TIME THOUGHTS ARE LEANING INCREASINGLY
TOWARDS MORE ISOLD COVERAGE AND MAINLY IN OUR SOUTH AND FAR EAST.
UPDATE ISSUED AT 1018 AM EDT MON SEP 8 2014
FOR THIS MORNINGS UPDATE BROUGHT GRIDS IN LINE WITH HOURLY OBS.
STUBBORN FOG AND LOW STRATUS IS LINGERING ACROSS THE AREA THIS
MORNING...MAINLY DUE TO NORTHEAST WINDS ACROSS MUCH OF THE CWA WHICH
DO TEND TO KEEP LOW STRATUS IN PLACE. HOWEVER STILL EXPECT A GRADUAL
LIFTING AND EROSION OF THE FOG AND STRATUS ONCE EFFECTS OF SUN ARE
ABLE TO BURN THROUGH TO THE SFC. A WEAK SOUTHEASTERN DOWN SLOPE FLOW
APPEARS TO BE KEEPING THE FOG AND STRATUS AT BAY ACROSS OUR HIGHER
TERRAIN IN THE SOUTHEAST.
MID LEVEL SHORT WAVE CONTINUES TO ROLL UP INTO THE MID OHIO VALLEY
THIS MORNING. THIS FEATURE IS FAIRLY VISIBLE IN WATER VAPOR IMAGES.
WHILE CAN NOT TOTALLY RULE OUT SOME SHOWER AND THUNDERSTORM ACTIVITY
THROUGH THE DAY CONFIDENCE IS WANING CONSIDERABLY. THE RAP...AND TO A
LESSER EXTENT GFS FCST SOUNDINGS ARE SHOWING A WEAK CAP ACROSS MUCH
OF THE AREA. THIS IS SOMEWHAT IN LINE WITH ILN/OHX MORNING SOUNDINGS
THOUGH BEING GENERALLY OUTSIDE OF THE INFLUENCE OF THE SHORTWAVE
THEY MAY NOT BE A GOOD REPRESENTATION OF THE PROFILE ACROSS OUR AREA.
DISCOUNTED THE NAM/S SOUNDING AS IN TYPICAL FASHION IT GREATLY
OVERDOES BOUNDARY LAYER MOISTURE AND CONSEQUENTLY BOUNDARY LAYER
INSTABILITY AND SOUNDING PARAMETERS. THE HRRR HAS TRENDED TOWARDS A
BIT LESS COVERAGE IN ACTIVITY AS WELL...AND INITIATES A BIT LATER IN
THE DAY THAN PREVIOUS RUNS. DID DELAY DEVELOPMENT OF ACTIVITY UNTIL
LATE MORNING/EARLY AFTERNOON BUT IN GENERAL KEPT INHERITED ISOLD AND
SCT POPS FOR THE AFTERNOON TIME FRAME.
UPDATE ISSUED AT 730 AM EDT MON SEP 8 2014
TWEAKED THE GRIDS A BIT EARLY THIS MORNING TO FINE TUNE THE SKY COVER
AND T/TD PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM EDT MON SEP 8 2014
07Z SFC ANALYSIS SHOWS COOL AND DRY HIGH PRESSURE SPRAWLED OUT FROM
THE OHIO VALLEY THROUGH THE NEW ENGLAND STATES. GENERAL LOW PRESSURE
IS FOUND OVER THE DEEP SOUTH AND ALONG THE SOUTHEAST COAST. NOT FAR
FROM EAST KENTUCKY IS A STALLED FRONTAL BOUNDARY LURKING JUST TO THE
SOUTH. THIS HAS HELPED TO PREVENT THE DRY COMPONENT OF THE HIGH
PRESSURE FROM MAKING IT THROUGH ALL OF THE STATE AS DEWPOINTS ALONG
THE TENNESSEE BORDER ARE IN THE LOW AND MID 60S WHILE MID AND UPPER
50S EXIST TO THE NORTH. THESE NORTHERN SPOTS ARE ALSO ENJOYING
TEMPERATURES DOWN INTO THE MIDDLE AND UPPER 50S...PARTICULARLY IN THE
VALLEYS WHERE MOSTLY CLEAR SKIES HAVE ALLOWED FOR DECENT RADIATIONAL
COOLING BELOW THE THERMAL INVERSION. MEANWHILE...RIDGES AND LOCATIONS
TO THE SOUTH WITH HIGHER DEWPOINTS ARE SEEING TEMPERATURES A FEW
DEGREES MORE. A COUPLE LARGE PATCHES OF LOW CLOUDS ARE AFFECTING
SOUTHEAST KENTUCKY EARLY THIS MORNING HELPING TO DISRUPT THE FOG
FORMATION...THOUGH THERE WILL UNDOUBTEDLY BE PATCHY FOG...LOCALLY
DENSE...IN MANY VALLEY LOCATIONS GENERALLY CORRESPONDING TO THE
CLEAR SPOTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH ANOTHER POCKET OF ENERGY
ROLLING EAST THROUGH GENERALLY FLAT FLOW TODAY...HELPING TO LOWER
HEIGHTS LOCALLY AND BRING SOME EXTRA LIFT TO THE AREA. THIS MOVES
THROUGH BY EVENING WITH CONTINUED RELATIVELY FAST AND NEARLY ZONAL
FLOW INTO THE DAY TUESDAY. LATE IN THE SHORT TERM PORTION OF THE
FORECAST HEIGHTS WILL CLIMB A NOTCH AHEAD OF A LARGE AND DEEPENING
TROUGH OVER THE ROCKY MOUNTAIN AND HIGH PLAINS STATES. WITH THE MODEL
SIMILARITIES HAVE GONE MAINLY WITH A BLEND OF THE HRRR AND NAM12 FOR
WX SPECIFICS DURING THE FIRST 12-18 HOURS AND THEN THE 00Z
ECMWF/NAM12 THROUGH TUESDAY.
SENSIBLE WEATHER WILL FEATURE A CONTINUED COOL AND DRY DAY ACROSS THE
FAR NORTHWEST PARTS OF THE AREA WHILE TO THE SOUTHEAST THERE WILL BE
MUCH MORE CLOUD COVER ALONG WITH A THREAT FOR SHOWERS THROUGH
THE MORNING. BY MIDDAY THUNDER CHANCES WILL PICK UP OWING TO BUILDING
INSTABILITY AND THE NEARBY FRONT BEING ACTED UPON BY THE PASSING MID
LEVEL SHORT WAVE. THE PCPN THREAT AND SOME OF THE CLOUD COVER WILL
RETREAT TO THE EAST LATER TONIGHT WITH ANOTHER NIGHT OF MINOR RIDGE
TO VALLEY TEMPERATURE DIFFERENCES AMIDST A NW TO SE STRIATION IN
DEWPOINTS. DUE TO THIS ANTICIPATE PATCHY VALLEY FOG AFTER MIDNIGHT
FOR MOST LOCATIONS...PARTICULARLY ONES THAT MANAGE TO SEE ANY RAIN
DURING THE DAY AND EVENING. TUESDAY WILL BE QUIET AND DRY...BUT A TAD
WARMER WHILE THE DEVELOPING LOW TO THE EAST STARTS TO LIFT NORTH
ALONG THE SOUTH EAST ATLANTIC SEABOARD.
STARTED WITH THE CONSSHORT FOR T...TD...AND WINDS...THROUGH THE
FIRST 24 HOURS FOLLOWED BY THE SUPERBLEND UNTIL 00Z WED. PER
USUAL...MADE MINOR ADJUSTMENTS FOR TERRAIN DIFFERENCES WITH TEMPS
TONIGHT. AS FOR POPS...ENDED UP CLOSER TO THE LOWER MAV GUIDANCE
TODAY AND SIMILAR TO A BLEND OF THE RATHER LOW NUMBERS THEREAFTER
THROUGH THE REMAINDER OF THE SHORT TERM FORECAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM EDT MON SEP 8 2014
THE MODELS REMAIN IN GOOD AGREEMENT IN THE LONG TERM...WITH A LARGE
RIDGE OF HIGH PRESSURE ALOFT INFLUENCING THE WEATHER OF EASTERN
KENTUCKY TO BEGIN THE PERIOD. DRY WEATHER SHOULD BE ON TAP TUESDAY
NIGHT INTO EARLY WEDNESDAY AFTERNOON AS HIGH PRESSURE REMAINS IN
CONTROL. HOWEVER...THIS UPPER RIDGE WILL BE DISPLACED AS DEEP AREA
OF LOW PRESSURE...BOTH ALOFT AND AT THE SURFACE...COMES TOGETHER
OVER THE NORTHERN PLAINS AND BEGINS TO PUSH ACROSS THE NORTHERN
MISSISSIPPI VALLEY ON WEDNESDAY. THE SURFACE COLD FRONT ASSOCIATED
WITH THIS POTENT SYSTEM WILL BRING UNSETTLED WEATHER TO THE AREA
WEDNESDAY NIGHT AND THURSDAY. THE PRIMARY CONCERN WITH THIS WEATHER
SYSTEM WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL. THE MODELS
HAVE THE FRONT SLOWING DOWN AND NEARLY STALLING ACROSS OUR AREA ON
THURSDAY. SHOWERS AND STORMS ARE EXPECTED TO FIRE ALL ALONG THE
BOUNDARY AS LARGE AMOUNTS OF WARM MOIST AIR OFF THE GULF OF MEXICO
IS CARRIED NORTHWARD INTO THE BOUNDARY ON SOUTHERLY WINDS. THE BEST
CHANCE FOR RAIN LOOKS TO BE FROM LATE THURSDAY MORNING THROUGH LATE
THURSDAY AFTERNOON WHEN MOISTURE FLOW INTO THE FRONTAL ZONE IS AT
ITS PEAK. THERE WILL ALSO BE THE POTENTIAL FOR A FEW STRONG
THUNDERSTORMS ON THURSDAY AS THE FRONT MOVES THROUGH AS THERE WILL
BE STRONG DYNAMICS ASSOCIATED WITH THE BOUNDARY AND ITS PARENT UPPER
LEVEL SYSTEM. THUNDERSTORMS SHOULD THEN GIVE WAY TO RAIN SHOWER
BEHIND THE FRONT THURSDAY NIGHT AS THE COOLER AIR MOVES IN BEHIND
THE FRONT. THE FRONT IS EXPECTED TO EVENTUALLY CLEAR THE AREA LATE
THURSDAY NIGHT INTO EARLY FRIDAY MORNING...AS A LARGE RIDGE OF
CANADIAN HIGH PRESSURE PUSHES IT OFF TO OUR EAST. THIS AREA OF HIGH
PRESSURE WILL BRING A SIGNIFICANT PATTERN CHANGE TO THE MAJORITY OF
THE CONUS EAST OF THE ROCKY MOUNTAINS FROM FRIDAY ONWARD.
AFTER SLIGHTLY ABOVE NORMAL TEMPERATURES TUESDAY NIGHT AND
WEDNESDAY...A PERIOD OF UNSEASONABLE COOLING WILL BE OCCURRING.
HIGHS ON WEDNESDAY ARE EXPECTED TO TOP OUT IN THE MID TO UPPER 80S
AS SOUTHERLY WINDS BRING WARM MOIST AIR FROM THE GULF OF MEXICO INTO
THE REGION. ONCE THE FRONT ARRIVES ON THURSDAY...WIDESPREAD CLOUD
COVER AND PRECIPITATION WILL KEEP TEMPERATURES WELL BELOW
NORMAL...WITH HIGHS ONLY CLIMBING TO AROUND 80 BY THURSDAY
AFTERNOON. ONCE THE BOUNDARY HAS CLEARED THE AREA LATE THURSDAY
NIGHT...AN INVASION OF COOL AN DRY CANADIAN AIR WILL BEGIN TO OCCUR.
WITH WINDS SHIFTING TO THE NORTH BEHIND THE FRONT...TEMPERATURES
WILL BE HARD PRESSED TO CLIMB INTO THE MID 70S ON FRIDAY. THE COOL
WEATHER WILL THEN PERSIST THROUGH THE WEEKEND AS THE RIDGE OF HIGH
PRESSURE BECOMES MORE FIRMLY ESTABLISHED. HIGH TEMPERATURES ON
SATURDAY ARE EXPECTED TO ONLY CLIMB TO AROUND 70 WITH HIGHS ON
SUNDAY ONLY WARMING INTO THE LOW 70S. OVERNIGHT LOWS IN THE 50S ARE
EXPECTED AREA WIDE FRIDAY AND SATURDAY NIGHT AS THE COOL CANADIAN
AIR POURS INTO THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 750 AM EDT MON SEP 8 2014
A LOW CLOUD DECK REMAINS IN PLACE OVER MUCH OF EAST KENTUCKY WITH
STILL SOME WESTWARD EXPANSION NOTED IN THE SATELLITE TRENDS. THESE
CLOUDS ARE GENERALLY IN THE MVFR RANGE FOR CIGS...BUT THERE ARE AREAS
OF MUCH LOWER CIGS DOWN TO LIFR IN THE SOUTH ALONG WITH LOW VIS FROM
FOG. ISOLATED TO SCATTERED RAIN SHOWERS ARE EXPECTED TO REDEVELOP...
MAINLY EAST OF JKL...BY MID MORNING AND PERSISTING INTO THE AFTERNOON.
AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT AS WELL THROUGH THE
EARLY EVENING HOURS. HAVE A VCTS FOR THIS IN THE ALL THE TAFS EXCEPT
SYM. WINDS THROUGH THE PERIOD WILL BE LIGHT AND VARIABLE ACROSS THE
FORECAST AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
1018 AM EDT MON SEP 8 2014
.UPDATE...
ISSUED AT 1018 AM EDT MON SEP 8 2014
FOR THIS MORNINGS UPDATE BROUGHT GRIDS IN LINE WITH HOURLY OBS.
STUBBORN FOG AND LOW STRATUS IS LINGERING ACROSS THE AREA THIS
MORNING...MAINLY DUE TO NORTHEAST WINDS ACROSS MUCH OF THE CWA WHICH
DO TEND TO KEEP LOW STRATUS IN PLACE. HOWEVER STILL EXPECT A GRADUAL
LIFTING AND EROSION OF THE FOG AND STRATUS ONCE EFFECTS OF SUN ARE
ABLE TO BURN THROUGH TO THE SFC. A WEAK SOUTHEASTERN DOWN SLOPE FLOW
APPEARS TO BE KEEPING THE FOG AND STRATUS AT BAY ACROSS OUR HIGHER
TERRAIN IN THE SOUTHEAST.
MID LEVEL SHORT WAVE CONTINUES TO ROLL UP INTO THE MID OHIO VALLEY
THIS MORNING. THIS FEATURE IS FAIRLY VISIBLE IN WATER VAPOR IMAGES.
WHILE CAN NOT TOTALLY RULE OUT SOME SHOWER AND THUNDERSTORM ACTIVITY
THROUGH THE DAY CONFIDENCE IS WANING CONSIDERABLY. THE RAP...AND TO A
LESSER EXTENT GFS FCST SOUNDINGS ARE SHOWING A WEAK CAP ACROSS MUCH
OF THE AREA. THIS IS SOMEWHAT IN LINE WITH ILN/OHX MORNING SOUNDINGS
THOUGH BEING GENERALLY OUTSIDE OF THE INFLUENCE OF THE SHORTWAVE
THEY MAY NOT BE A GOOD REPRESENTATION OF THE PROFILE ACROSS OUR AREA.
DISCOUNTED THE NAM/S SOUNDING AS IN TYPICAL FASHION IT GREATLY
OVERDOES BOUNDARY LAYER MOISTURE AND CONSEQUENTLY BOUNDARY LAYER
INSTABILITY AND SOUNDING PARAMETERS. THE HRRR HAS TRENDED TOWARDS A
BIT LESS COVERAGE IN ACTIVITY AS WELL...AND INITIATES A BIT LATER IN
THE DAY THAN PREVIOUS RUNS. DID DELAY DEVELOPMENT OF ACTIVITY UNTIL
LATE MORNING/EARLY AFTERNOON BUT IN GENERAL KEPT INHERITED ISOLD AND
SCT POPS FOR THE AFTERNOON TIME FRAME.
UPDATE ISSUED AT 730 AM EDT MON SEP 8 2014
TWEAKED THE GRIDS A BIT EARLY THIS MORNING TO FINE TUNE THE SKY COVER
AND T/TD PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM EDT MON SEP 8 2014
07Z SFC ANALYSIS SHOWS COOL AND DRY HIGH PRESSURE SPRAWLED OUT FROM
THE OHIO VALLEY THROUGH THE NEW ENGLAND STATES. GENERAL LOW PRESSURE
IS FOUND OVER THE DEEP SOUTH AND ALONG THE SOUTHEAST COAST. NOT FAR
FROM EAST KENTUCKY IS A STALLED FRONTAL BOUNDARY LURKING JUST TO THE
SOUTH. THIS HAS HELPED TO PREVENT THE DRY COMPONENT OF THE HIGH
PRESSURE FROM MAKING IT THROUGH ALL OF THE STATE AS DEWPOINTS ALONG
THE TENNESSEE BORDER ARE IN THE LOW AND MID 60S WHILE MID AND UPPER
50S EXIST TO THE NORTH. THESE NORTHERN SPOTS ARE ALSO ENJOYING
TEMPERATURES DOWN INTO THE MIDDLE AND UPPER 50S...PARTICULARLY IN THE
VALLEYS WHERE MOSTLY CLEAR SKIES HAVE ALLOWED FOR DECENT RADIATIONAL
COOLING BELOW THE THERMAL INVERSION. MEANWHILE...RIDGES AND LOCATIONS
TO THE SOUTH WITH HIGHER DEWPOINTS ARE SEEING TEMPERATURES A FEW
DEGREES MORE. A COUPLE LARGE PATCHES OF LOW CLOUDS ARE AFFECTING
SOUTHEAST KENTUCKY EARLY THIS MORNING HELPING TO DISRUPT THE FOG
FORMATION...THOUGH THERE WILL UNDOUBTEDLY BE PATCHY FOG...LOCALLY
DENSE...IN MANY VALLEY LOCATIONS GENERALLY CORRESPONDING TO THE
CLEAR SPOTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH ANOTHER POCKET OF ENERGY
ROLLING EAST THROUGH GENERALLY FLAT FLOW TODAY...HELPING TO LOWER
HEIGHTS LOCALLY AND BRING SOME EXTRA LIFT TO THE AREA. THIS MOVES
THROUGH BY EVENING WITH CONTINUED RELATIVELY FAST AND NEARLY ZONAL
FLOW INTO THE DAY TUESDAY. LATE IN THE SHORT TERM PORTION OF THE
FORECAST HEIGHTS WILL CLIMB A NOTCH AHEAD OF A LARGE AND DEEPENING
TROUGH OVER THE ROCKY MOUNTAIN AND HIGH PLAINS STATES. WITH THE MODEL
SIMILARITIES HAVE GONE MAINLY WITH A BLEND OF THE HRRR AND NAM12 FOR
WX SPECIFICS DURING THE FIRST 12-18 HOURS AND THEN THE 00Z
ECMWF/NAM12 THROUGH TUESDAY.
SENSIBLE WEATHER WILL FEATURE A CONTINUED COOL AND DRY DAY ACROSS THE
FAR NORTHWEST PARTS OF THE AREA WHILE TO THE SOUTHEAST THERE WILL BE
MUCH MORE CLOUD COVER ALONG WITH A THREAT FOR SHOWERS THROUGH
THE MORNING. BY MIDDAY THUNDER CHANCES WILL PICK UP OWING TO BUILDING
INSTABILITY AND THE NEARBY FRONT BEING ACTED UPON BY THE PASSING MID
LEVEL SHORT WAVE. THE PCPN THREAT AND SOME OF THE CLOUD COVER WILL
RETREAT TO THE EAST LATER TONIGHT WITH ANOTHER NIGHT OF MINOR RIDGE
TO VALLEY TEMPERATURE DIFFERENCES AMIDST A NW TO SE STRIATION IN
DEWPOINTS. DUE TO THIS ANTICIPATE PATCHY VALLEY FOG AFTER MIDNIGHT
FOR MOST LOCATIONS...PARTICULARLY ONES THAT MANAGE TO SEE ANY RAIN
DURING THE DAY AND EVENING. TUESDAY WILL BE QUIET AND DRY...BUT A TAD
WARMER WHILE THE DEVELOPING LOW TO THE EAST STARTS TO LIFT NORTH
ALONG THE SOUTH EAST ATLANTIC SEABOARD.
STARTED WITH THE CONSSHORT FOR T...TD...AND WINDS...THROUGH THE
FIRST 24 HOURS FOLLOWED BY THE SUPERBLEND UNTIL 00Z WED. PER
USUAL...MADE MINOR ADJUSTMENTS FOR TERRAIN DIFFERENCES WITH TEMPS
TONIGHT. AS FOR POPS...ENDED UP CLOSER TO THE LOWER MAV GUIDANCE
TODAY AND SIMILAR TO A BLEND OF THE RATHER LOW NUMBERS THEREAFTER
THROUGH THE REMAINDER OF THE SHORT TERM FORECAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM EDT MON SEP 8 2014
THE MODELS REMAIN IN GOOD AGREEMENT IN THE LONG TERM...WITH A LARGE
RIDGE OF HIGH PRESSURE ALOFT INFLUENCING THE WEATHER OF EASTERN
KENTUCKY TO BEGIN THE PERIOD. DRY WEATHER SHOULD BE ON TAP TUESDAY
NIGHT INTO EARLY WEDNESDAY AFTERNOON AS HIGH PRESSURE REMAINS IN
CONTROL. HOWEVER...THIS UPPER RIDGE WILL BE DISPLACED AS DEEP AREA
OF LOW PRESSURE...BOTH ALOFT AND AT THE SURFACE...COMES TOGETHER
OVER THE NORTHERN PLAINS AND BEGINS TO PUSH ACROSS THE NORTHERN
MISSISSIPPI VALLEY ON WEDNESDAY. THE SURFACE COLD FRONT ASSOCIATED
WITH THIS POTENT SYSTEM WILL BRING UNSETTLED WEATHER TO THE AREA
WEDNESDAY NIGHT AND THURSDAY. THE PRIMARY CONCERN WITH THIS WEATHER
SYSTEM WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL. THE MODELS
HAVE THE FRONT SLOWING DOWN AND NEARLY STALLING ACROSS OUR AREA ON
THURSDAY. SHOWERS AND STORMS ARE EXPECTED TO FIRE ALL ALONG THE
BOUNDARY AS LARGE AMOUNTS OF WARM MOIST AIR OFF THE GULF OF MEXICO
IS CARRIED NORTHWARD INTO THE BOUNDARY ON SOUTHERLY WINDS. THE BEST
CHANCE FOR RAIN LOOKS TO BE FROM LATE THURSDAY MORNING THROUGH LATE
THURSDAY AFTERNOON WHEN MOISTURE FLOW INTO THE FRONTAL ZONE IS AT
ITS PEAK. THERE WILL ALSO BE THE POTENTIAL FOR A FEW STRONG
THUNDERSTORMS ON THURSDAY AS THE FRONT MOVES THROUGH AS THERE WILL
BE STRONG DYNAMICS ASSOCIATED WITH THE BOUNDARY AND ITS PARENT UPPER
LEVEL SYSTEM. THUNDERSTORMS SHOULD THEN GIVE WAY TO RAIN SHOWER
BEHIND THE FRONT THURSDAY NIGHT AS THE COOLER AIR MOVES IN BEHIND
THE FRONT. THE FRONT IS EXPECTED TO EVENTUALLY CLEAR THE AREA LATE
THURSDAY NIGHT INTO EARLY FRIDAY MORNING...AS A LARGE RIDGE OF
CANADIAN HIGH PRESSURE PUSHES IT OFF TO OUR EAST. THIS AREA OF HIGH
PRESSURE WILL BRING A SIGNIFICANT PATTERN CHANGE TO THE MAJORITY OF
THE CONUS EAST OF THE ROCKY MOUNTAINS FROM FRIDAY ONWARD.
AFTER SLIGHTLY ABOVE NORMAL TEMPERATURES TUESDAY NIGHT AND
WEDNESDAY...A PERIOD OF UNSEASONABLE COOLING WILL BE OCCURRING.
HIGHS ON WEDNESDAY ARE EXPECTED TO TOP OUT IN THE MID TO UPPER 80S
AS SOUTHERLY WINDS BRING WARM MOIST AIR FROM THE GULF OF MEXICO INTO
THE REGION. ONCE THE FRONT ARRIVES ON THURSDAY...WIDESPREAD CLOUD
COVER AND PRECIPITATION WILL KEEP TEMPERATURES WELL BELOW
NORMAL...WITH HIGHS ONLY CLIMBING TO AROUND 80 BY THURSDAY
AFTERNOON. ONCE THE BOUNDARY HAS CLEARED THE AREA LATE THURSDAY
NIGHT...AN INVASION OF COOL AN DRY CANADIAN AIR WILL BEGIN TO OCCUR.
WITH WINDS SHIFTING TO THE NORTH BEHIND THE FRONT...TEMPERATURES
WILL BE HARD PRESSED TO CLIMB INTO THE MID 70S ON FRIDAY. THE COOL
WEATHER WILL THEN PERSIST THROUGH THE WEEKEND AS THE RIDGE OF HIGH
PRESSURE BECOMES MORE FIRMLY ESTABLISHED. HIGH TEMPERATURES ON
SATURDAY ARE EXPECTED TO ONLY CLIMB TO AROUND 70 WITH HIGHS ON
SUNDAY ONLY WARMING INTO THE LOW 70S. OVERNIGHT LOWS IN THE 50S ARE
EXPECTED AREA WIDE FRIDAY AND SATURDAY NIGHT AS THE COOL CANADIAN
AIR POURS INTO THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 750 AM EDT MON SEP 8 2014
A LOW CLOUD DECK REMAINS IN PLACE OVER MUCH OF EAST KENTUCKY WITH
STILL SOME WESTWARD EXPANSION NOTED IN THE SATELLITE TRENDS. THESE
CLOUDS ARE GENERALLY IN THE MVFR RANGE FOR CIGS...BUT THERE ARE AREAS
OF MUCH LOWER CIGS DOWN TO LIFR IN THE SOUTH ALONG WITH LOW VIS FROM
FOG. ISOLATED TO SCATTERED RAIN SHOWERS ARE EXPECTED TO REDEVELOP...
MAINLY EAST OF JKL...BY MID MORNING AND PERSISTING INTO THE AFTERNOON.
AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT AS WELL THROUGH THE
EARLY EVENING HOURS. HAVE A VCTS FOR THIS IN THE ALL THE TAFS EXCEPT
SYM. WINDS THROUGH THE PERIOD WILL BE LIGHT AND VARIABLE ACROSS THE
FORECAST AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
750 AM EDT MON SEP 8 2014
.UPDATE...
ISSUED AT 730 AM EDT MON SEP 8 2014
TWEAKED THE GRIDS A BIT EARLY THIS MORNING TO FINE TUNE THE SKY COVER
AND T/TD PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM EDT MON SEP 8 2014
07Z SFC ANALYSIS SHOWS COOL AND DRY HIGH PRESSURE SPRAWLED OUT FROM
THE OHIO VALLEY THROUGH THE NEW ENGLAND STATES. GENERAL LOW PRESSURE
IS FOUND OVER THE DEEP SOUTH AND ALONG THE SOUTHEAST COAST. NOT FAR
FROM EAST KENTUCKY IS A STALLED FRONTAL BOUNDARY LURKING JUST TO THE
SOUTH. THIS HAS HELPED TO PREVENT THE DRY COMPONENT OF THE HIGH
PRESSURE FROM MAKING IT THROUGH ALL OF THE STATE AS DEWPOINTS ALONG
THE TENNESSEE BORDER ARE IN THE LOW AND MID 60S WHILE MID AND UPPER
50S EXIST TO THE NORTH. THESE NORTHERN SPOTS ARE ALSO ENJOYING
TEMPERATURES DOWN INTO THE MIDDLE AND UPPER 50S...PARTICULARLY IN THE
VALLEYS WHERE MOSTLY CLEAR SKIES HAVE ALLOWED FOR DECENT RADIATIONAL
COOLING BELOW THE THERMAL INVERSION. MEANWHILE...RIDGES AND LOCATIONS
TO THE SOUTH WITH HIGHER DEWPOINTS ARE SEEING TEMPERATURES A FEW
DEGREES MORE. A COUPLE LARGE PATCHES OF LOW CLOUDS ARE AFFECTING
SOUTHEAST KENTUCKY EARLY THIS MORNING HELPING TO DISRUPT THE FOG
FORMATION...THOUGH THERE WILL UNDOUBTEDLY BE PATCHY FOG...LOCALLY
DENSE...IN MANY VALLEY LOCATIONS GENERALLY CORRESPONDING TO THE
CLEAR SPOTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH ANOTHER POCKET OF ENERGY
ROLLING EAST THROUGH GENERALLY FLAT FLOW TODAY...HELPING TO LOWER
HEIGHTS LOCALLY AND BRING SOME EXTRA LIFT TO THE AREA. THIS MOVES
THROUGH BY EVENING WITH CONTINUED RELATIVELY FAST AND NEARLY ZONAL
FLOW INTO THE DAY TUESDAY. LATE IN THE SHORT TERM PORTION OF THE
FORECAST HEIGHTS WILL CLIMB A NOTCH AHEAD OF A LARGE AND DEEPENING
TROUGH OVER THE ROCKY MOUNTAIN AND HIGH PLAINS STATES. WITH THE MODEL
SIMILARITIES HAVE GONE MAINLY WITH A BLEND OF THE HRRR AND NAM12 FOR
WX SPECIFICS DURING THE FIRST 12-18 HOURS AND THEN THE 00Z
ECMWF/NAM12 THROUGH TUESDAY.
SENSIBLE WEATHER WILL FEATURE A CONTINUED COOL AND DRY DAY ACROSS THE
FAR NORTHWEST PARTS OF THE AREA WHILE TO THE SOUTHEAST THERE WILL BE
MUCH MORE CLOUD COVER ALONG WITH A THREAT FOR SHOWERS THROUGH
THE MORNING. BY MIDDAY THUNDER CHANCES WILL PICK UP OWING TO BUILDING
INSTABILITY AND THE NEARBY FRONT BEING ACTED UPON BY THE PASSING MID
LEVEL SHORT WAVE. THE PCPN THREAT AND SOME OF THE CLOUD COVER WILL
RETREAT TO THE EAST LATER TONIGHT WITH ANOTHER NIGHT OF MINOR RIDGE
TO VALLEY TEMPERATURE DIFFERENCES AMIDST A NW TO SE STRIATION IN
DEWPOINTS. DUE TO THIS ANTICIPATE PATCHY VALLEY FOG AFTER MIDNIGHT
FOR MOST LOCATIONS...PARTICULARLY ONES THAT MANAGE TO SEE ANY RAIN
DURING THE DAY AND EVENING. TUESDAY WILL BE QUIET AND DRY...BUT A TAD
WARMER WHILE THE DEVELOPING LOW TO THE EAST STARTS TO LIFT NORTH
ALONG THE SOUTH EAST ATLANTIC SEABOARD.
STARTED WITH THE CONSSHORT FOR T...TD...AND WINDS...THROUGH THE
FIRST 24 HOURS FOLLOWED BY THE SUPERBLEND UNTIL 00Z WED. PER
USUAL...MADE MINOR ADJUSTMENTS FOR TERRAIN DIFFERENCES WITH TEMPS
TONIGHT. AS FOR POPS...ENDED UP CLOSER TO THE LOWER MAV GUIDANCE
TODAY AND SIMILAR TO A BLEND OF THE RATHER LOW NUMBERS THEREAFTER
THROUGH THE REMAINDER OF THE SHORT TERM FORECAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM EDT MON SEP 8 2014
THE MODELS REMAIN IN GOOD AGREEMENT IN THE LONG TERM...WITH A LARGE
RIDGE OF HIGH PRESSURE ALOFT INFLUENCING THE WEATHER OF EASTERN
KENTUCKY TO BEGIN THE PERIOD. DRY WEATHER SHOULD BE ON TAP TUESDAY
NIGHT INTO EARLY WEDNESDAY AFTERNOON AS HIGH PRESSURE REMAINS IN
CONTROL. HOWEVER...THIS UPPER RIDGE WILL BE DISPLACED AS DEEP AREA
OF LOW PRESSURE...BOTH ALOFT AND AT THE SURFACE...COMES TOGETHER
OVER THE NORTHERN PLAINS AND BEGINS TO PUSH ACROSS THE NORTHERN
MISSISSIPPI VALLEY ON WEDNESDAY. THE SURFACE COLD FRONT ASSOCIATED
WITH THIS POTENT SYSTEM WILL BRING UNSETTLED WEATHER TO THE AREA
WEDNESDAY NIGHT AND THURSDAY. THE PRIMARY CONCERN WITH THIS WEATHER
SYSTEM WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL. THE MODELS
HAVE THE FRONT SLOWING DOWN AND NEARLY STALLING ACROSS OUR AREA ON
THURSDAY. SHOWERS AND STORMS ARE EXPECTED TO FIRE ALL ALONG THE
BOUNDARY AS LARGE AMOUNTS OF WARM MOIST AIR OFF THE GULF OF MEXICO
IS CARRIED NORTHWARD INTO THE BOUNDARY ON SOUTHERLY WINDS. THE BEST
CHANCE FOR RAIN LOOKS TO BE FROM LATE THURSDAY MORNING THROUGH LATE
THURSDAY AFTERNOON WHEN MOISTURE FLOW INTO THE FRONTAL ZONE IS AT
ITS PEAK. THERE WILL ALSO BE THE POTENTIAL FOR A FEW STRONG
THUNDERSTORMS ON THURSDAY AS THE FRONT MOVES THROUGH AS THERE WILL
BE STRONG DYNAMICS ASSOCIATED WITH THE BOUNDARY AND ITS PARENT UPPER
LEVEL SYSTEM. THUNDERSTORMS SHOULD THEN GIVE WAY TO RAIN SHOWER
BEHIND THE FRONT THURSDAY NIGHT AS THE COOLER AIR MOVES IN BEHIND
THE FRONT. THE FRONT IS EXPECTED TO EVENTUALLY CLEAR THE AREA LATE
THURSDAY NIGHT INTO EARLY FRIDAY MORNING...AS A LARGE RIDGE OF
CANADIAN HIGH PRESSURE PUSHES IT OFF TO OUR EAST. THIS AREA OF HIGH
PRESSURE WILL BRING A SIGNIFICANT PATTERN CHANGE TO THE MAJORITY OF
THE CONUS EAST OF THE ROCKY MOUNTAINS FROM FRIDAY ONWARD.
AFTER SLIGHTLY ABOVE NORMAL TEMPERATURES TUESDAY NIGHT AND
WEDNESDAY...A PERIOD OF UNSEASONABLE COOLING WILL BE OCCURRING.
HIGHS ON WEDNESDAY ARE EXPECTED TO TOP OUT IN THE MID TO UPPER 80S
AS SOUTHERLY WINDS BRING WARM MOIST AIR FROM THE GULF OF MEXICO INTO
THE REGION. ONCE THE FRONT ARRIVES ON THURSDAY...WIDESPREAD CLOUD
COVER AND PRECIPITATION WILL KEEP TEMPERATURES WELL BELOW
NORMAL...WITH HIGHS ONLY CLIMBING TO AROUND 80 BY THURSDAY
AFTERNOON. ONCE THE BOUNDARY HAS CLEARED THE AREA LATE THURSDAY
NIGHT...AN INVASION OF COOL AN DRY CANADIAN AIR WILL BEGIN TO OCCUR.
WITH WINDS SHIFTING TO THE NORTH BEHIND THE FRONT...TEMPERATURES
WILL BE HARD PRESSED TO CLIMB INTO THE MID 70S ON FRIDAY. THE COOL
WEATHER WILL THEN PERSIST THROUGH THE WEEKEND AS THE RIDGE OF HIGH
PRESSURE BECOMES MORE FIRMLY ESTABLISHED. HIGH TEMPERATURES ON
SATURDAY ARE EXPECTED TO ONLY CLIMB TO AROUND 70 WITH HIGHS ON
SUNDAY ONLY WARMING INTO THE LOW 70S. OVERNIGHT LOWS IN THE 50S ARE
EXPECTED AREA WIDE FRIDAY AND SATURDAY NIGHT AS THE COOL CANADIAN
AIR POURS INTO THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 750 AM EDT MON SEP 8 2014
A LOW CLOUD DECK REMAINS IN PLACE OVER MUCH OF EAST KENTUCKY WITH
STILL SOME WESTWARD EXPANSION NOTED IN THE SATELLITE TRENDS. THESE
CLOUDS ARE GENERALLY IN THE MVFR RANGE FOR CIGS...BUT THERE ARE AREAS
OF MUCH LOWER CIGS DOWN TO LIFR IN THE SOUTH ALONG WITH LOW VIS FROM
FOG. ISOLATED TO SCATTERED RAIN SHOWERS ARE EXPECTED TO REDEVELOP...
MAINLY EAST OF JKL...BY MID MORNING AND PERSISTING INTO THE AFTERNOON.
AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT AS WELL THROUGH THE
EARLY EVENING HOURS. HAVE A VCTS FOR THIS IN THE ALL THE TAFS EXCEPT
SYM. WINDS THROUGH THE PERIOD WILL BE LIGHT AND VARIABLE ACROSS THE
FORECAST AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
345 AM EDT MON SEP 8 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM EDT MON SEP 8 2014
07Z SFC ANALYSIS SHOWS COOL AND DRY HIGH PRESSURE SPRAWLED OUT FROM
THE OHIO VALLEY THROUGH THE NEW ENGLAND STATES. GENERAL LOW PRESSURE
IS FOUND OVER THE DEEP SOUTH AND ALONG THE SOUTHEAST COAST. NOT FAR
FROM EAST KENTUCKY IS A STALLED FRONTAL BOUNDARY LURKING JUST TO THE
SOUTH. THIS HAS HELPED TO PREVENT THE DRY COMPONENT OF THE HIGH
PRESSURE FROM MAKING IT THROUGH ALL OF THE STATE AS DEWPOINTS ALONG
THE TENNESSEE BORDER ARE IN THE LOW AND MID 60S WHILE MID AND UPPER
50S EXIST TO THE NORTH. THESE NORTHERN SPOTS ARE ALSO ENJOYING
TEMPERATURES DOWN INTO THE MIDDLE AND UPPER 50S...PARTICULARLY IN THE
VALLEYS WHERE MOSTLY CLEAR SKIES HAVE ALLOWED FOR DECENT RADIATIONAL
COOLING BELOW THE THERMAL INVERSION. MEANWHILE...RIDGES AND LOCATIONS
TO THE SOUTH WITH HIGHER DEWPOINTS ARE SEEING TEMPERATURES A FEW
DEGREES MORE. A COUPLE LARGE PATCHES OF LOW CLOUDS ARE AFFECTING
SOUTHEAST KENTUCKY EARLY THIS MORNING HELPING TO DISRUPT THE FOG
FORMATION...THOUGH THERE WILL UNDOUBTEDLY BE PATCHY FOG...LOCALLY
DENSE...IN MANY VALLEY LOCATIONS GENERALLY CORRESPONDING TO THE
CLEAR SPOTS.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH ANOTHER POCKET OF ENERGY
ROLLING EAST THROUGH GENERALLY FLAT FLOW TODAY...HELPING TO LOWER
HEIGHTS LOCALLY AND BRING SOME EXTRA LIFT TO THE AREA. THIS MOVES
THROUGH BY EVENING WITH CONTINUED RELATIVELY FAST AND NEARLY ZONAL
FLOW INTO THE DAY TUESDAY. LATE IN THE SHORT TERM PORTION OF THE
FORECAST HEIGHTS WILL CLIMB A NOTCH AHEAD OF A LARGE AND DEEPENING
TROUGH OVER THE ROCKY MOUNTAIN AND HIGH PLAINS STATES. WITH THE MODEL
SIMILARITIES HAVE GONE MAINLY WITH A BLEND OF THE HRRR AND NAM12 FOR
WX SPECIFICS DURING THE FIRST 12-18 HOURS AND THEN THE 00Z
ECMWF/NAM12 THROUGH TUESDAY.
SENSIBLE WEATHER WILL FEATURE A CONTINUED COOL AND DRY DAY ACROSS THE
FAR NORTHWEST PARTS OF THE AREA WHILE TO THE SOUTHEAST THERE WILL BE
MUCH MORE CLOUD COVER ALONG WITH A THREAT FOR SHOWERS THROUGH
THE MORNING. BY MIDDAY THUNDER CHANCES WILL PICK UP OWING TO BUILDING
INSTABILITY AND THE NEARBY FRONT BEING ACTED UPON BY THE PASSING MID
LEVEL SHORT WAVE. THE PCPN THREAT AND SOME OF THE CLOUD COVER WILL
RETREAT TO THE EAST LATER TONIGHT WITH ANOTHER NIGHT OF MINOR RIDGE
TO VALLEY TEMPERATURE DIFFERENCES AMIDST A NW TO SE STRIATION IN
DEWPOINTS. DUE TO THIS ANTICIPATE PATCHY VALLEY FOG AFTER MIDNIGHT
FOR MOST LOCATIONS...PARTICULARLY ONES THAT MANAGE TO SEE ANY RAIN
DURING THE DAY AND EVENING. TUESDAY WILL BE QUIET AND DRY...BUT A TAD
WARMER WHILE THE DEVELOPING LOW TO THE EAST STARTS TO LIFT NORTH
ALONG THE SOUTH EAST ATLANTIC SEABOARD.
STARTED WITH THE CONSSHORT FOR T...TD...AND WINDS...THROUGH THE
FIRST 24 HOURS FOLLOWED BY THE SUPERBLEND UNTIL 00Z WED. PER
USUAL...MADE MINOR ADJUSTMENTS FOR TERRAIN DIFFERENCES WITH TEMPS
TONIGHT. AS FOR POPS...ENDED UP CLOSER TO THE LOWER MAV GUIDANCE
TODAY AND SIMILAR TO A BLEND OF THE RATHER LOW NUMBERS THEREAFTER
THROUGH THE REMAINDER OF THE SHORT TERM FORECAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM EDT MON SEP 8 2014
THE MODELS REMAIN IN GOOD AGREEMENT IN THE LONG TERM...WITH A LARGE
RIDGE OF HIGH PRESSURE ALOFT INFLUENCING THE WEATHER OF EASTERN
KENTUCKY TO BEGIN THE PERIOD. DRY WEATHER SHOULD BE ON TAP TUESDAY
NIGHT INTO EARLY WEDNESDAY AFTERNOON AS HIGH PRESSURE REMAINS IN
CONTROL. HOWEVER...THIS UPPER RIDGE WILL BE DISPLACED AS DEEP AREA
OF LOW PRESSURE...BOTH ALOFT AND AT THE SURFACE...COMES TOGETHER
OVER THE NORTHERN PLAINS AND BEGINS TO PUSH ACROSS THE NORTHERN
MISSISSIPPI VALLEY ON WEDNESDAY. THE SURFACE COLD FRONT ASSOCIATED
WITH THIS POTENT SYSTEM WILL BRING UNSETTLED WEATHER TO THE AREA
WEDNESDAY NIGHT AND THURSDAY. THE PRIMARY CONCERN WITH THIS WEATHER
SYSTEM WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL. THE MODELS
HAVE THE FRONT SLOWING DOWN AND NEARLY STALLING ACROSS OUR AREA ON
THURSDAY. SHOWERS AND STORMS ARE EXPECTED TO FIRE ALL ALONG THE
BOUNDARY AS LARGE AMOUNTS OF WARM MOIST AIR OFF THE GULF OF MEXICO
IS CARRIED NORTHWARD INTO THE BOUNDARY ON SOUTHERLY WINDS. THE BEST
CHANCE FOR RAIN LOOKS TO BE FROM LATE THURSDAY MORNING THROUGH LATE
THURSDAY AFTERNOON WHEN MOISTURE FLOW INTO THE FRONTAL ZONE IS AT
ITS PEAK. THERE WILL ALSO BE THE POTENTIAL FOR A FEW STRONG
THUNDERSTORMS ON THURSDAY AS THE FRONT MOVES THROUGH AS THERE WILL
BE STRONG DYNAMICS ASSOCIATED WITH THE BOUNDARY AND ITS PARENT UPPER
LEVEL SYSTEM. THUNDERSTORMS SHOULD THEN GIVE WAY TO RAIN SHOWER
BEHIND THE FRONT THURSDAY NIGHT AS THE COOLER AIR MOVES IN BEHIND
THE FRONT. THE FRONT IS EXPECTED TO EVENTUALLY CLEAR THE AREA LATE
THURSDAY NIGHT INTO EARLY FRIDAY MORNING...AS A LARGE RIDGE OF
CANADIAN HIGH PRESSURE PUSHES IT OFF TO OUR EAST. THIS AREA OF HIGH
PRESSURE WILL BRING A SIGNIFICANT PATTERN CHANGE TO THE MAJORITY OF
THE CONUS EAST OF THE ROCKY MOUNTAINS FROM FRIDAY ONWARD.
AFTER SLIGHTLY ABOVE NORMAL TEMPERATURES TUESDAY NIGHT AND
WEDNESDAY...A PERIOD OF UNSEASONABLE COOLING WILL BE OCCURRING.
HIGHS ON WEDNESDAY ARE EXPECTED TO TOP OUT IN THE MID TO UPPER 80S
AS SOUTHERLY WINDS BRING WARM MOIST AIR FROM THE GULF OF MEXICO INTO
THE REGION. ONCE THE FRONT ARRIVES ON THURSDAY...WIDESPREAD CLOUD
COVER AND PRECIPITATION WILL KEEP TEMPERATURES WELL BELOW
NORMAL...WITH HIGHS ONLY CLIMBING TO AROUND 80 BY THURSDAY
AFTERNOON. ONCE THE BOUNDARY HAS CLEARED THE AREA LATE THURSDAY
NIGHT...AN INVASION OF COOL AN DRY CANADIAN AIR WILL BEGIN TO OCCUR.
WITH WINDS SHIFTING TO THE NORTH BEHIND THE FRONT...TEMPERATURES
WILL BE HARD PRESSED TO CLIMB INTO THE MID 70S ON FRIDAY. THE COOL
WEATHER WILL THEN PERSIST THROUGH THE WEEKEND AS THE RIDGE OF HIGH
PRESSURE BECOMES MORE FIRMLY ESTABLISHED. HIGH TEMPERATURES ON
SATURDAY ARE EXPECTED TO ONLY CLIMB TO AROUND 70 WITH HIGHS ON
SUNDAY ONLY WARMING INTO THE LOW 70S. OVERNIGHT LOWS IN THE 50S ARE
EXPECTED AREA WIDE FRIDAY AND SATURDAY NIGHT AS THE COOL CANADIAN
AIR POURS INTO THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 230 AM EDT MON SEP 8 2014
A LOW CLOUD DECK IS HOLDING ON OVER FAR SOUTHEAST KENTUCKY WITH SOME
WESTWARD PUSH NOTED IN THE SATELLITE TRENDS. THESE CLOUDS ARE
GENERALLY IN THE MVFR RANGE FOR CIGS. HOWEVER...THEY ARE HELPING TO
KEEP THE FOG AT BAY FOR MANY OF THE SITES IN THE EAST THOUGH IT
CANNOT BE COMPLETELY RULED OUT...ESPECIALLY IF THERE ARE ANY BREAKS.
WILL CONTINUE THE FORECAST FOR LOWERING CIGS AND POORER AVIATION
CONDITIONS THROUGH DAWN. ISOLATED TO SCATTERED RAIN SHOWERS ARE
EXPECTED TO REDEVELOP...MAINLY EAST OF JKL...TOWARD MORNING
PERSISTING INTO THE DAY. AN ISOLATED THUNDERSTORM CANNOT BE RULED
OUT MONDAY AFTERNOON AND INTO THE EARLY EVENING HOURS...AS WELL. HAVE
ADDED A VCTS FOR THIS IN THE ALL THE TAFS EXCEPT SYM. WINDS THROUGH
THE PERIOD WILL BE LIGHT AND VARIABLE ACROSS THE FORECAST AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1148 PM EDT TUE SEP 9 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 344 PM EDT TUE SEP 9 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
DEVELOPING MID/UPPER LEVEL TROUGH OVER THE WRN CONUS. THE TAIL OF AN
ELONGATED SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WAS DRAGGING A
COLD FRONT SLOWLY SOUTH INTO WRN LAKE SUPERIOR. A VIGOROUS SRN
STREAM SHRTWV MOVING IN THE CNTRL PLAINS WILL SUPPORT DEVELOPMENT OF
A SFC LOW THAT WILL MOVE INTO THE WRN LAKES WED. EVEN WITH LAKE
BREEZE ONSHORE WINDS INTO WRN UPPER MI...LOW LEVEL CONV HAS NOT BEEN
STRONG ENOUGH TO OVERCOME CAPPING WITH 800-750 MB TEMPS NEAR
12C...PER RUC. OTHERWISE...ABUNDANT CU PREVAILED ACROSS THE WEST
HALF OF UPPER MI WHILE MORE STABLE AIR OFF OF LAKE MI HAS KEPT SKIES
MOSTLY CLEAR OVER THE EAST.
THE POTENTIAL REMAINS FOR SOME SHRA/TSRA THIS EVENING AS THE FRONTAL
BOUNDARY MOVES THROUGH WRN UPPER MI. HOWEVER...COVERAGE SHOULD
LIMITED WITH ONLY LOWER END CHANCE POPS GIVEN THE STRENGTH OF THE
CAPPING.
AS THE PLAINS SHRTWV MOVES TOWARD THE AREA AND THE SFC LOW
DEEPENS...300-310 ISENTROPIC ASCENT ALONG WITH 800-600 MB FGEN WILL
STRENGTHEN AND SUPPORT AN EXPANDING AREA OF MODERATE TO HEAVY RAIN
FROM NW/N WI INTO WRN UPPER MI BY LATE EVENING AND INTO CNTRL UPPER
MI LATE TONIGHT. STRONG MID/UPPER LEVEL DYNAMICS WITH A COUPLED
UPPER LEVEL JET STRUCTURE AND STRONG QVECTOR CONV WILL SUPPORT A
LARGE AREA OF RAIN ACROSS THE CWA WED. SOME MODEL UNCERTAINTY
REMAINS AS THE NAM REMAINS MUCH DEEPER AND FARTHER TO THE NW THAN
MODELS CONSENSUS AND THE GFS FASTER AND ALONG THE SOUTHERN ENVELOPE
OF MODEL SPREAD. FAVORED THE MORE CONSISTENT ECMWF AND REGIONAL GEM
WITH THE LOW PATH TO NEAR GRB BY 18Z AND THE STRAITS BY 00Z/THU.
VERY STRONG 850 MB MOISTURE INFLOW...UPPER LEVEL AND 800-600 MB FGEN
EVEN WITHOUT TSRA WILL BRING THE POTENTIAL FOR A PERIOD OF HEAVY
RAIN...ESPECIALLY BTWN 09Z-18Z. UNCERTAINTY REMAINS ON THE IMPACT OF
UPSTREAM CONVECTION OVER IA INTO SRN WI ON THE EVOLUTION OF THE
850-700 MB FRONTAL BOUNDARY AND MOISTURE INFLOW TO THE NORTH.
HOWEVER...THE POTENTIAL REMAINS FOR QPF IN THE 1.5 INCH TO 2.0 INCH
RANGE...WITH LOCALLY HIGHER AMOUNTS AOA 3 INCHES. SO THE FLOOD WATCH
WILL REMAINS IN EFFECT.
NE WINDS VEERING TO THE NNE WILL ALSO INCREASE WITH GUSTS LIKELY IN
INTO THE 40-50 KNOT RANGE BY TO LATE AFTERNOON OVER THE
KEWEENAW...ESPECIALLY FOR LOCATIONS FAVORED BY NNE FLOW SUCH AS
COPPER HARBOR. AN ADVISORY WILL LIKELY BE NEEDED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM EDT TUE SEP 9 2014
SOME DISCREPANCIES BETWEEN MODELS AT 00Z THU. TWO EXTREMES WITH THE
LOW LOCATION/STRENGTH ARE THE 12Z/09 GFS WITH A 997MB SFC LOW NEAR
CENTRAL LAKE HURON AND THE 12Z/09 NAM WITH A 984MB SFC LOW NEAR
MUNISING. HARD TO JUMP ON BOARD WITH EITHER OF THESE TWO EXTREMES
GIVEN WARM SEASON PROCESSES THAT WILL OCCUR IN THE WARM SECTOR OF
THE LOW...BUT THINK A MIDDLE OF THE GROUND APPROACH IS MORE
REASONABLE. REGARDLESS...STRONG NLY WINDS WILL BE ONGOING ACROSS THE
CWA AT 00Z THU...AND IF THE FARTHER N/STRONGER SOLUTION IS
CORRECT...THE WINDS WOULD BE VERY STRONG. THE HIGH EXTREME OF THE
NAM EVEN HAS 925MB WINDS UP TO 70KTS /POSSIBLY RESULTING IN SFC
GUSTS OF 55-70KTS/ BETWEEN 00Z AND 06Z THU...WHICH CAN NOT BE RULED
OUT...BUT MORE MODERATE WINDS ARE EXPECTED. BY 06Z...EVEN THE NAM
HAS THE LOW E OF LAKE SUPERIOR...WITH OTHER MODELS FARTHER SE. BY
12Z THU...925MB WINDS ARE EXPECTED TO BE BELOW 30KTS...WITH THE
PRESSURE GRADIENT RELAXING FASTER DURING THE DAY THU. MOST OF THE
PRECIP WED NIGHT INTO THU WILL BE DUE TO WRAP AROUND MOISTURE AND
UPSLOPE FLOW AND SHOULD GRADUALLY DIMINISH INTO THU EVENING.
THU LOOKS TO BE COLDEST DAY IN A WHILE AREA WIDE AS CLOUDY
CONDITIONS PERSIST BEHIND THE SYSTEM AND 850MB TEMPS WILL BE -2C TO
1C...RESULTING IN HIGH TEMPS FROM THE UPPER 40S INTERIOR W TO THE
LOW 50S ELSEWHERE...AND THE CONTINUED BREEZY WINDS WILL ONLY MAKE IT
FEEL COOLER.
GIVEN THE COLD TEMPS...THINK BELOW FREEZING MIN TEMPS THU NIGHT LOOK
FAIRLY LIKELY OVER THE INTERIOR W...WITH A MORE CONDITIONAL CHANCE
FRI NIGHT DEPENDING ON THE CLOUD COVER.
NOT SURE ABOUT PRECIP CHANCES FRI INTO FRI INTO SAT AS MODELS POINT
TO AN UPPER LEVEL DISTURBANCE MOVING INTO THE REGION OVER SFC HIGH
PRESSURE. ONLY LOW END POPS WILL REMAIN IN THE FORECAST AS THE ECMWF
IS THE ONLY MODEL SHOWING SIGNIFICANT PRECIP ACROSS THE CWA...THE
OTHER MODELS HAVE A WEAKER WAVE AND LESS MOISTURE. 850MB TEMPS
REMAIN MOSTLY THE SAME THROUGH SAT AT AROUND 0C...BUT CLOUD COVER
SHOULD BE LOWER EACH FRI AND ESPECIALLY SAT...SO HIGHS WILL WARM
INTO THE MID TO UPPER 50S BE SAT.
POSSIBILITY OF ANOTHER WAVE ON SUN AND MAYBE YET ANOTHER ON MON AS A
RIDGE BUILDS ACROSS THE WRN CONUS AND A TROUGH ACROSS THE ERN CONUS.
EVEN LOWER CONFIDENCE ON PRECIP WITH THESE FEATURES AS MOISTURE WILL
BE LIMITED AS THE TRACK/STRENGTH OF THE ENERGY IS UNCERTAIN. TEMPS
DO LOOK TO INCREASE BUT WILL REMAIN BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM EDT TUE SEP 9 2014
NNE WIND SHIFT BEHIND A COLD FRONT MOVED BROUGHT LIFR CLOUDS INTO
IWD/CMX LAST EVENING. A FEW SHRA/TSRA HAVE ALSO POPPED UP ALONG
FRONTAL BOUNDARY MAINLY AT IWD. AS A STRONGER DISTURBANCE MOVES NEWD
AND THE MOIST LYR DEEPENS...WIDESPREAD RAIN WILL DEVELOP FROM SW TO
NE AND KEEPING CONDITIONS LIFR AT IWD/CMX INTO MUCH OF WED. SINCE
THE FROPA WL OCCUR LATER AT SAW...THE TRANSITION TO MVFR WILL NOT
OCCUR UNTIL AROUND 08Z. BY LATE TONIGHT INTO WED MORNING LIFR
CONDITIONS WILL PREVAIL AT SAW AS WELL WITH MODERATE TO OCNLY HEAVY
RAIN AND GUSTY NE-N WINDS DEVELOPING BY LATE MORNING/AFTERNOON. NE-N
WIND WILL GUST OVER 30 KT AT KCMX AND POSSIBLY AOA 25 KTS AT KSAW
AND IWD BY LATE MORNING/MIDDAY WED.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 344 PM EDT TUE SEP 9 2014
THE TROUGH STRETCHED ACROSS W LAKE SUPERIOR WILL DRIFT ACROSS LAKE
SUPERIOR THIS EVENING AS LOW PRESSURE APPROACHES FROM THE CENTRAL
PLAINS. THE LOW WILL BE OVER E IOWA BY DAYBREAK WEDNESDAY...AND
CONTINUE TO PUSH TO NRN LOWER MI BY WED EVENING...BEFORE EXITING
INTO QUEBEC ON THURSDAY. NORTHEAST GALES TO AROUND 40KTS WILL BE
POSSIBLE WEDNESDAY MORNING OVER W LAKE SUPERIOR...BEFORE SLOWLY
EXPANDING TO CENTRAL LAKE SUPERIOR WEDNESDAY EVENING THROUGH THE
OVERNIGHT HOURS AS WINDS BACK TO THE NORTH. LARGE HIGH PRESSURE OVER
S ALBERTA AND SASKATCHEWAN THURSDAY WILL SINK ACROSS THE N AND
CENTRAL PLAINS...WHILE BUILDING A RIDGE ACROSS LAKE SUPERIOR
THURSDAY NIGHT THROUGH SATURDAY WITH WINDS GUSTING TO AROUND 20KTS
OR LESS.
&&
.HYDROLOGY...
ISSUED AT 344 PM EDT TUE SEP 9 2014
RAINFALL TOTALS FROM TONIGHT THROUGH WEDNESDAY NIGHT ACROSS UPPER MI
RANGE FROM JUST OVER 1.5 TO LOCALLY 3 INCHES. UNCERTAINTY REMAINS
WHERE THE HEAVIER BANDS OF RAIN WILL DEVELOP. HIGHER TOTALS INTO WED
NIGHT ARE EXPECTED FOR LOCATIONS IN N CNTRL UPPER MI WHERE STRONG
UPSLOPE FLOW WILL BOOST RAINFALL AMOUNTS. THE FLOOD WATCH REMAINS
POSTED FOR MUCH OF W AND CENTRAL UPPER MI.
EXPECT THE TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A
SIGNIFICANT POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF
A PERIOD OF HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO
AN 0.5-1.0 INCH PER HOUR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH THROUGH WEDNESDAY EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM WEDNESDAY TO 8 AM EDT THURSDAY FOR LSZ251-
267.
GALE WARNING FROM 2 PM WEDNESDAY TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 5 AM WEDNESDAY TO 4 AM EDT THURSDAY FOR
LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...VOSS
MARINE...JLB
HYDROLOGY...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
912 PM EDT TUE SEP 9 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 344 PM EDT TUE SEP 9 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
DEVELOPING MID/UPPER LEVEL TROUGH OVER THE WRN CONUS. THE TAIL OF AN
ELONGATED SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WAS DRAGGING A
COLD FRONT SLOWLY SOUTH INTO WRN LAKE SUPERIOR. A VIGOROUS SRN
STREAM SHRTWV MOVING IN THE CNTRL PLAINS WILL SUPPORT DEVELOPMENT OF
A SFC LOW THAT WILL MOVE INTO THE WRN LAKES WED. EVEN WITH LAKE
BREEZE ONSHORE WINDS INTO WRN UPPER MI...LOW LEVEL CONV HAS NOT BEEN
STRONG ENOUGH TO OVERCOME CAPPING WITH 800-750 MB TEMPS NEAR
12C...PER RUC. OTHERWISE...ABUNDANT CU PREVAILED ACROSS THE WEST
HALF OF UPPER MI WHILE MORE STABLE AIR OFF OF LAKE MI HAS KEPT SKIES
MOSTLY CLEAR OVER THE EAST.
THE POTENTIAL REMAINS FOR SOME SHRA/TSRA THIS EVENING AS THE FRONTAL
BOUNDARY MOVES THROUGH WRN UPPER MI. HOWEVER...COVERAGE SHOULD
LIMITED WITH ONLY LOWER END CHANCE POPS GIVEN THE STRENGTH OF THE
CAPPING.
AS THE PLAINS SHRTWV MOVES TOWARD THE AREA AND THE SFC LOW
DEEPENS...300-310 ISENTROPIC ASCENT ALONG WITH 800-600 MB FGEN WILL
STRENGTHEN AND SUPPORT AN EXPANDING AREA OF MODERATE TO HEAVY RAIN
FROM NW/N WI INTO WRN UPPER MI BY LATE EVENING AND INTO CNTRL UPPER
MI LATE TONIGHT. STRONG MID/UPPER LEVEL DYNAMICS WITH A COUPLED
UPPER LEVEL JET STRUCTURE AND STRONG QVECTOR CONV WILL SUPPORT A
LARGE AREA OF RAIN ACROSS THE CWA WED. SOME MODEL UNCERTAINTY
REMAINS AS THE NAM REMAINS MUCH DEEPER AND FARTHER TO THE NW THAN
MODELS CONSENSUS AND THE GFS FASTER AND ALONG THE SOUTHERN ENVELOPE
OF MODEL SPREAD. FAVORED THE MORE CONSISTENT ECMWF AND REGIONAL GEM
WITH THE LOW PATH TO NEAR GRB BY 18Z AND THE STRAITS BY 00Z/THU.
VERY STRONG 850 MB MOISTURE INFLOW...UPPER LEVEL AND 800-600 MB FGEN
EVEN WITHOUT TSRA WILL BRING THE POTENTIAL FOR A PERIOD OF HEAVY
RAIN...ESPECIALLY BTWN 09Z-18Z. UNCERTAINTY REMAINS ON THE IMPACT OF
UPSTREAM CONVECTION OVER IA INTO SRN WI ON THE EVOLUTION OF THE
850-700 MB FRONTAL BOUNDARY AND MOISTURE INFLOW TO THE NORTH.
HOWEVER...THE POTENTIAL REMAINS FOR QPF IN THE 1.5 INCH TO 2.0 INCH
RANGE...WITH LOCALLY HIGHER AMOUNTS AOA 3 INCHES. SO THE FLOOD WATCH
WILL REMAINS IN EFFECT.
NE WINDS VEERING TO THE NNE WILL ALSO INCREASE WITH GUSTS LIKELY IN
INTO THE 40-50 KNOT RANGE BY TO LATE AFTERNOON OVER THE
KEWEENAW...ESPECIALLY FOR LOCATIONS FAVORED BY NNE FLOW SUCH AS
COPPER HARBOR. AN ADVISORY WILL LIKELY BE NEEDED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM EDT TUE SEP 9 2014
SOME DISCREPANCIES BETWEEN MODELS AT 00Z THU. TWO EXTREMES WITH THE
LOW LOCATION/STRENGTH ARE THE 12Z/09 GFS WITH A 997MB SFC LOW NEAR
CENTRAL LAKE HURON AND THE 12Z/09 NAM WITH A 984MB SFC LOW NEAR
MUNISING. HARD TO JUMP ON BOARD WITH EITHER OF THESE TWO EXTREMES
GIVEN WARM SEASON PROCESSES THAT WILL OCCUR IN THE WARM SECTOR OF
THE LOW...BUT THINK A MIDDLE OF THE GROUND APPROACH IS MORE
REASONABLE. REGARDLESS...STRONG NLY WINDS WILL BE ONGOING ACROSS THE
CWA AT 00Z THU...AND IF THE FARTHER N/STRONGER SOLUTION IS
CORRECT...THE WINDS WOULD BE VERY STRONG. THE HIGH EXTREME OF THE
NAM EVEN HAS 925MB WINDS UP TO 70KTS /POSSIBLY RESULTING IN SFC
GUSTS OF 55-70KTS/ BETWEEN 00Z AND 06Z THU...WHICH CAN NOT BE RULED
OUT...BUT MORE MODERATE WINDS ARE EXPECTED. BY 06Z...EVEN THE NAM
HAS THE LOW E OF LAKE SUPERIOR...WITH OTHER MODELS FARTHER SE. BY
12Z THU...925MB WINDS ARE EXPECTED TO BE BELOW 30KTS...WITH THE
PRESSURE GRADIENT RELAXING FASTER DURING THE DAY THU. MOST OF THE
PRECIP WED NIGHT INTO THU WILL BE DUE TO WRAP AROUND MOISTURE AND
UPSLOPE FLOW AND SHOULD GRADUALLY DIMINISH INTO THU EVENING.
THU LOOKS TO BE COLDEST DAY IN A WHILE AREA WIDE AS CLOUDY
CONDITIONS PERSIST BEHIND THE SYSTEM AND 850MB TEMPS WILL BE -2C TO
1C...RESULTING IN HIGH TEMPS FROM THE UPPER 40S INTERIOR W TO THE
LOW 50S ELSEWHERE...AND THE CONTINUED BREEZY WINDS WILL ONLY MAKE IT
FEEL COOLER.
GIVEN THE COLD TEMPS...THINK BELOW FREEZING MIN TEMPS THU NIGHT LOOK
FAIRLY LIKELY OVER THE INTERIOR W...WITH A MORE CONDITIONAL CHANCE
FRI NIGHT DEPENDING ON THE CLOUD COVER.
NOT SURE ABOUT PRECIP CHANCES FRI INTO FRI INTO SAT AS MODELS POINT
TO AN UPPER LEVEL DISTURBANCE MOVING INTO THE REGION OVER SFC HIGH
PRESSURE. ONLY LOW END POPS WILL REMAIN IN THE FORECAST AS THE ECMWF
IS THE ONLY MODEL SHOWING SIGNIFICANT PRECIP ACROSS THE CWA...THE
OTHER MODELS HAVE A WEAKER WAVE AND LESS MOISTURE. 850MB TEMPS
REMAIN MOSTLY THE SAME THROUGH SAT AT AROUND 0C...BUT CLOUD COVER
SHOULD BE LOWER EACH FRI AND ESPECIALLY SAT...SO HIGHS WILL WARM
INTO THE MID TO UPPER 50S BE SAT.
POSSIBILITY OF ANOTHER WAVE ON SUN AND MAYBE YET ANOTHER ON MON AS A
RIDGE BUILDS ACROSS THE WRN CONUS AND A TROUGH ACROSS THE ERN CONUS.
EVEN LOWER CONFIDENCE ON PRECIP WITH THESE FEATURES AS MOISTURE WILL
BE LIMITED AS THE TRACK/STRENGTH OF THE ENERGY IS UNCERTAIN. TEMPS
DO LOOK TO INCREASE BUT WILL REMAIN BELOW NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 904 PM EDT TUE SEP 9 2014
A COLD FRONT MOVED THROUGH IWD/CMX EARLY THIS EVENING WITH A WIND
SHIFT TO THE NNE BEHIND THE FRONTAL PASSAGE. THE ARRIVAL OF SOME
SHALLOW COOL AIR OFF LAKE SUPERIOR SHOULD BRING SOME MVFR CLDS INTO
THOSE LOCATIONS THIS EVENING WITH SOME ISOLD SHRA/TSRA AT KIWD. AS A
STRONGER DISTURBANCE MOVES NEWD AND THE MOIST LYR DEEPENS...RAIN WILL
DEVELOP FROM SW TO NE AND CAUSE CONDITIONS AT IWD/CMX TO DROP TO IFR
BY OVERNIGHT. SINCE THE FROPA WL OCCUR LATER AT SAW...THE TRANSITION
TO MVFR WILL NOT OCCUR UNTIL AFT 06Z. BY LATE TONIGHT INTO WED
MORNING LIFR CONDITIONS WILL PREVAIL AT THE TAF SITES WITH MODERATE
TO OCNLY HEAVY RAIN AND GUSTY NE-N WINDS DEVELOPING BY LATE
MORNING/AFTERNOON. NE-N WIND WILL GUST OVER 30 KT AT KCMX AND
POSSIBLY AOA 25 KTS AT KSAW BY AFTERNOON. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 344 PM EDT TUE SEP 9 2014
THE TROUGH STRETCHED ACROSS W LAKE SUPERIOR WILL DRIFT ACROSS LAKE
SUPERIOR THIS EVENING AS LOW PRESSURE APPROACHES FROM THE CENTRAL
PLAINS. THE LOW WILL BE OVER E IOWA BY DAYBREAK WEDNESDAY...AND
CONTINUE TO PUSH TO NRN LOWER MI BY WED EVENING...BEFORE EXITING
INTO QUEBEC ON THURSDAY. NORTHEAST GALES TO AROUND 40KTS WILL BE
POSSIBLE WEDNESDAY MORNING OVER W LAKE SUPERIOR...BEFORE SLOWLY
EXPANDING TO CENTRAL LAKE SUPERIOR WEDNESDAY EVENING THROUGH THE
OVERNIGHT HOURS AS WINDS BACK TO THE NORTH. LARGE HIGH PRESSURE OVER
S ALBERTA AND SASKATCHEWAN THURSDAY WILL SINK ACROSS THE N AND
CENTRAL PLAINS...WHILE BUILDING A RIDGE ACROSS LAKE SUPERIOR
THURSDAY NIGHT THROUGH SATURDAY WITH WINDS GUSTING TO AROUND 20KTS
OR LESS.
&&
.HYDROLOGY...
ISSUED AT 344 PM EDT TUE SEP 9 2014
RAINFALL TOTALS FROM TONIGHT THROUGH WEDNESDAY NIGHT ACROSS UPPER MI
RANGE FROM JUST OVER 1.5 TO LOCALLY 3 INCHES. UNCERTAINTY REMAINS
WHERE THE HEAVIER BANDS OF RAIN WILL DEVELOP. HIGHER TOTALS INTO WED
NIGHT ARE EXPECTED FOR LOCATIONS IN N CNTRL UPPER MI WHERE STRONG
UPSLOPE FLOW WILL BOOST RAINFALL AMOUNTS. THE FLOOD WATCH REMAINS
POSTED FOR MUCH OF W AND CENTRAL UPPER MI.
EXPECT THE TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A
SIGNIFICANT POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF
A PERIOD OF HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO
AN 0.5-1.0 INCH PER HOUR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH FROM 2 AM EDT /1 AM CDT/ WEDNESDAY THROUGH WEDNESDAY
EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM WEDNESDAY TO 8 AM EDT THURSDAY FOR LSZ251-
267.
GALE WARNING FROM 2 PM WEDNESDAY TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 8 AM WEDNESDAY TO 4 AM EDT THURSDAY FOR
LSZ243>245-264.
GALE WARNING FROM 5 AM EDT /4 AM CDT/ WEDNESDAY TO 2 AM EDT /1
AM CDT/ THURSDAY FOR LSZ240>242-263.
GALE WARNING FROM 5 AM EDT /4 AM CDT/ TO 11 PM EDT /10 PM CDT/
WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...VOSS
MARINE...JLB
HYDROLOGY...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 PM EDT MON SEP 8 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EDT MON SEP 8 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS AND SRN CANADA. A SHORTWAVE TROUGH OVER WI AND
ASSOCIATED 700-300 MB QVECTOR CONV SUPPORTED SOME VERY LIGHT RAIN
SHOWERS OR SPINKLES OVER NRN WI INTO FAR WRN UPPER MI. WITH THE
FORCING MAINLY IN THE 500-300 MB LAYER AND RELATIVELY DRY LOW LEVELS
JUST MID LEVEL CLOUDS/CIGS WERE REPORTED WITH MOST STATIONS NOT EVEN
REPORTING ANY MEASURABLE AMOUNTS. OTHERWISE...PARLTY CLOUDY SKIES
WITH GUSTY SOUTH WINDS OF 15 TO 25 MPH PREVAILED OVER THE REST OF
THE CWA.
TONIGHT...EXPECT THE -SHRA/SPRINKLES OVER SW UPPER MI TO SLOWLY
SLIDE TO THE EAST THIS EVENING AS THE SHRTWV DEPARTS. THE LEFTOVER
MID CLOUDS SHOULD ALSO THIN OUT OVERNIGHT AS QVECTOR DIV SPREADS
INTO THE AREA. HOWEVER...WITH INCREASING SW FLOW 925-700 MB THETA-E
ADVECTION ADDITIONAL CLOUDS MAY SPREAD INTO THE WEST HALF LATE. THE
SRLY FLOW WILL KEEP MIN READINGS IN THE MID 50S INLAND TO AROUND 60
IN DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR.
TUESDAY...THE MODELS SUGGEST THAT A FRONTAL BOUNDARY WILL SLOWLY
DROP THROUGH WRN LAKE SUPERIOR AND AIDED BY THE LAKE BREEZE INTO THE
NW CWA BY AFTERNOON. THE COMBINATION OF THE APPROACHING FRONTAL
BOUNDARY...MLCAPE VALUES INTO THE 1K-2K RANGE...RELATIVELY WEAK
CAPPING AND THE POTENTIAL A WEAK SHORTWAVE BRUSHING THE AREA MAY
PRODUCE SOME ISOLD/SCT SHRA/TSRA BY MID TO LATE AFTERNOON OVER THE
WEST HALF. SINCE THE STRONGEST FORCING IS EXPECTED TO REMAIN NW OF
THE CWA...ONLY LOWER END CHANCE POPS WERE INCLUDED.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 431 PM EDT MON SEP 8 2014
THE MAIN ISSUES THIS FORECAST PERIOD WILL BE THE FLOODING POTENTIAL
TUESDAY NIGHT THROUGH WEDNESDAY MORNING...GALES ON LAKE SUPERIOR
WEDNESDAY INTO WEDNESDAY NIGHT AND COLDER THAN NORMAL TEMPERATURES
MOVING IN THURSDAY NIGHT THROUGH SATURDAY.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...LOW PRESSURE WILL INTENSIFY
OVER THE CENTRAL PLAINS AS IT LIFTS NORTHEASTWARD TO WESTERN IOWA
LATE TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING AT OR AROUND 1000MB.
AT THE SAME TIME...AN UPPER LEVEL 500MB TROUGH AXIS SLIDES ACROSS
THE ROCKIES INTO THE PLAINS STATES. MODELS ARE IN FAIRLY GOOD
AGREEMENT...HOWEVER...THE 12Z NAM IS A BIT OF AN OUTLIER...TAKING
THE LOW FARTHER NORTH AND WEST THAN THE OTHER MODELS. SHOWERS AND
THUNDERSTORMS WILL DEVELOP AHEAD OF THE LOW PRESSURE SYSTEM ON
INCREASED MOISTURE UPGLIDE AS SHOWN ON THE 300K ISOSURFACE ALONG
WITH INCREASING MOISTURE SHOWN BY PLOTTING 1000-500 RH. THE BEST
CHANCE OF CONVECTION WOULD BE TUESDAY EVENING WITH INSTABILITY
LINGERING ON THE WARM SIDE OF THE LOW. THE LOW WILL CONTINUE
NORTHEASTWARD TO JUST SOUTH OF JAMES BAY WHILE FURTHER STRENGTHENING
TO AROUND 990MB AS THE UPPER LEVEL TROUGH SLIDES INTO THE UPPER
MISSISSIPPI VALLEY. AT THIS POINT...THE HEAVY RAINFALL POTENTIAL
WOULD BE GREATEST LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING...AS
DEEP LAYER MOISTURE WOULD BE IN PLACE AT THE SAME TIME ISENTROPIC
UPGLIDE IS MAXIMIZED AND DEEP LAYER FORCING IS MAXIMIZED AS A FAIRLY
STRONG 700MB FGEN BAND WRAPS THROUGH THE AREA. ADDITIONALLY...THE
AREA WILL LIE IN THE LEFT EXIT REGION OF A JET MAX TO THE SOUTH AND
PARTIALLY IN THE INFLUENCE OF A RIGHT ENTRANCE REGION OF A JET MAX
TO THE NORTH. ALSO IN SUPPORT OF HEAVY RAINFALL TUESDAY NIGHT
THROUGH WEDNESDAY MORNING WILL BE PWAT VALUES CONTINUING TO BE
PROGGED AT 1.5 TO 2 INCHES ON STRONG SOUTHERLY MOISTURE TRANSPORT
INTO THE REGION. RAINFALL WILL CONTINUE THROUGH WEDNESDAY
NIGHT...HOWEVER...OVERALL INTENSITY IS EXPECTED TO DECREASE AS THE
AFOREMENTIONED HEAVY RAINFALL FEATURES SHIFT OUT OF THE AREA AND
MAINLY WRAP AROUND PRECIP LINGERS OVER GENERALLY THE WESTERN U.P. AS
A DRY SLOT IS PROGGED TO WEDGE INTO THE CENTRAL AND EASTERN
AREAS...ALLOWING FOR MAINLY DRIZZLE.
HEAVY RAINFALL POTENTIAL INCLUDING AREAL FLOOD WATCH...WITH THE DEEP
MOISTURE AND LIFT EXPECTED ACROSS THE AREA...RAINFALL TOTALS WILL
LIKELY EXCEED 2 INCHES WITH UP TO 3 INCHES POSSIBLE ACROSS PORTIONS
OF THE CENTRAL AND WESTERN UPPER PENINSULA. MOST OF THE RAINFALL IS
EXPECTED TO OCCUR IN A 12 HOUR PERIOD...BETWEEN 06Z/10 AND 18Z/10.
THIS HEAVY RAINFALL WILL OCCUR ON VERY SATURATED SOILS WHICH WILL
ALLOW RUNOFF TO BEGIN QUICKLY. MANY AREAS OF THE CENTRAL AND WESTERN
PORTIONS OF THE U.P. ARE RUNNING AROUND 2 TO 4 INCHES ABOVE THE 2
WEEK NORMAL DUE TO RECENT HEAVY RAINFALL. SEVERAL RIVERS WITHIN THE
FLOOD WATCH ARE RUNNING HIGHER THAN NORMAL WITH ANY ADDITIONAL
WIDESPREAD RAINFALL EXPECTED TO INCREASE THESE LEVEL...SOME OF WHICH
MAY APPROACH FLOOD STAGE...BASED ON HEAVIER RAINFALL GUIDANCE.
OUTSIDE OF THE RAINFALL POTENTIAL...STRONG WINDS WILL ALSO BE AN
ISSUE. AS THE LOW PUSHES INTO THE REGION...A FAIRLY STRONG AREA OF
HIGH PRESSURE WILL BUILD ACROSS MUCH OF WESTERN CANADA. THE PRESSURE
GRADIENT WILL TIGHTEN BETWEEN THE TWO SYSTEMS LATE TUESDAY NIGHT AND
ESPECIALLY DURING THE DAY WEDNESDAY. THE PERIOD OF STRONGEST WINDS
ARE EXPECTED TO PUSH THROUGH THE AREA LATE WEDNESDAY MORNING THROUGH
LATE WEDNESDAY NIGHT. WINDS OVER MUCH OF THE LAND AREAS AWAY FROM
THE SHORE WILL BE SUSTAINED AROUND 15 TO 25 MPH. OVER THE LAKE...THE
KEWEENAW PENINSULA AND AREAS NEAR THE SHORE WILL SEE WINDS
SUSTAINED CLOSER TO 35 TO 40 MPH WITH GUSTS REACHING AROUND 45 TO
EVEN 50 MPH. THIS IS SUPPORTED WITH CAA ACROSS THE LAKE ON THE BACK
SIDE OF THE LOW WITH RELATIVELY WARM LAKE SURFACE TEMPERATURES
ALLOWING STRONGER WINDS TO MIX DOWN TO THE LAKE SURFACE. SOUNDINGS
SUPPORT WINDS MIXING DOWN FROM AROUND 925-900MB...WHERE WINDS ARE
PROGGED TO BE RIGHT AROUND 45 TO 50 MPH. CONFIDENCE IN HIGH WINDS IS
FAIRLY HIGH OVER THE LAKE...WITH A BIT LOWER CONFIDENCE IN THE WIND
DIRECTION. HAVE DECIDED TO GO WITH A GALE WATCH BEGINNING WEDNESDAY
MORNING INTO LATE WEDNESDAY NIGHT.
THURSDAY THROUGH FRIDAY NIGHT...THE LOW PRESSURE SYSTEM NEAR JAMES
BAY WILL CONTINUE TO SLOWLY LIFT NORTHEAST...PUSHING INTO QUEBEC BY
THURSDAY AFTERNOON. AT THE SAME TIME...STRONG HIGH PRESSURE WILL
BUILD ACROSS MUCH OF THE UPPER MISSISSIPPI VALLEY. THE PRESSURE
GRADIENT MAY LINGER THROUGH THURSDAY MORNING OVER EASTERN LAKE
SUPERIOR KEEPING GALE FORCE GUSTS IN THE FORECAST...HOWEVER...AS THE
LOW SLIPS AWAY AND THE HIGH BUILDS IN...WINDS WILL DIMINISH DURING
THE AFTERNOON HOURS THURSDAY. UPPER LEVEL TROUGHING WILL LINGER
THROUGH FRIDAY NIGHT ACROSS THE AREA WITH A COUPLE SHORTWAVES
PUSHING THROUGH. THE COOLER AIR ALOFT ASSOCIATED WITH THE TROUGH
WILL ALLOW FOR CONTINUED CLOUD COVER ALONG WITH LIGHT RAIN SHOWERS.
BY LATE FRIDAY NIGHT THE HIGH PRESSURE CENTER MOVES OVERHEAD ALONG
WITH SLIGHT RIDGING ALOFT AND DRIER AIR...ALLOWING THE PRECIP TO END
AND SKIES TO CLEAR. TEMPERATURES COULD BE QUITE COOL FRIDAY NIGHT
WITH CALM CONDITIONS...CLEARING SKIES AND PWAT VALUES AROUND 30 TO
40 PERCENT OF NORMAL. KEPT THE IDEA OF SEEING BELOW FREEZING
TEMPERATURES ACROSS INLAND AREAS OF THE U.P.
SATURDAY THROUGH MONDAY...HIGH PRESSURE IS EXPECTED TO LINGER
THROUGH SATURDAY...KEEPING CONDITIONS DRY AND SKIES MAINLY CLEAR.
TEMPERATURES WILL BEGIN TO MODERATE SUNDAY INTO MONDAY ON RETURN
SOUTHERLY FLOW ON THE WEST SIDE OF THE HIGH. THE GFS/EC HAVE ANOTHER
SYSTEM PUSHING INTO THE AREA DURING THE SUNDAY NIGHT INTO MONDAY
TIME PERIOD...HOWEVER...THERE IS QUITE A BIT OF UNCERTAINTY IN THE
TRACK OF THE SYSTEM AND THE OVERALL STRENGTH AND TIMING OF THE UPPER
LEVEL TROUGH. LEANED HEAVILY ON A CONSENSUS OF THE MODELS DURING
THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 130 PM EDT MON SEP 8 2014
EXPECT VFR CONDITIONS THROUGH MOST OF THIS FCST PERIOD WITH STRONG
SSW FLOW TAPPING RELATIVELY DRY AIR SHOWN ON THE 00Z MPX RAOB.
DAYTIME HEATING/MIXING WILL ALLOW FOR GUSTY WINDS TO 20-25 KT THIS
AFTERNOON BEFORE DECOUPLING THIS EVENING MIGHT ALLOW FOR SOME
MARGINAL LLWS BEFORE THE LLJ WEAKENS AFTER 06Z. LOW LEVEL MOISTURE
WILL INCREASE FROM THE SW TUE MORNING WITH MVFR CIGS LIKELY AT IWD
AND CMX AND POSSIBLY AT SAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EDT MON SEP 8 2014
SRLY WINDS TO 20 KNOTS WILL CONTINUE TONIGHT BETWEEN HIGH PRES OVER
NEW ENGLAND AND A TROUGH FROM NW ONTARIO INTO THE NRN PLAINS.
LOOK FOR THE TROUGH TO PUSH INTO LAKE SUPERIOR ON TUESDAY...WHILE A
STRONGER LOW ORGANIZES ACROSS THE CENTRAL PLAINS. EXPECT THE
DEEPENING LOW TO SHIFT NE ACROSS WI ON WEDNESDAY...AND ACROSS E
UPPER MI AND N LOWER MI LATE WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING...BEFORE CONTINUING NE INTO QUEBEC ON THURSDAY. A PERIOD OF
N GALES IS EXPECTED FROM WED MORNING THROUGH WED NIGHT. WINDS WILL
DIMINISH THU AS HIGH PRES BUILDS FROM THE PLAINS INTO THE WRN LAKES.
&&
.HYDROLOGY...
ISSUED AT 431 PM EDT MON SEP 8 2014
HEAVY RAINFALL POTENTIAL INCLUDING AREAL FLOOD WATCH...WITH THE DEEP
MOISTURE AND LIFT EXPECTED ACROSS THE AREA...RAINFALL TOTALS WILL
LIKELY EXCEED 2 INCHES WITH UP TO 3 INCHES POSSIBLE ACROSS PORTIONS
OF THE CENTRAL AND WESTERN UPPER PENINSULA. MOST OF THE RAINFALL IS
EXPECTED TO OCCUR IN A 12 HOUR PERIOD...BETWEEN 06Z/10 AND 18Z/10.
THIS HEAVY RAINFALL WILL OCCUR ON VERY SATURATED SOILS WHICH WILL
ALLOW RUNOFF TO BEGIN QUICKLY. MANY AREAS OF THE CENTRAL AND WESTERN
PORTIONS OF THE U.P. ARE RUNNING AROUND 2 TO 4 INCHES ABOVE THE 2
WEEK NORMAL DUE TO RECENT HEAVY RAINFALL. SEVERAL RIVERS WITHIN THE
FLOOD WATCH ARE RUNNING SLIGHTLY HIGHER THAN NORMAL WITH ANY
ADDITIONAL WIDESPREAD RAINFALL EXPECTED TO INCREASE THESE
LEVEL...SOME OF WHICH MAY APPROACH FLOOD STAGE...BASED ON HEAVIER
RAINFALL GUIDANCE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY EVENING
FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY MORNING FOR
LSZ243>245-264>267.
GALE WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY NIGHT
FOR LSZ162-240>242-263.
GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
LSZ248>251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...JLB
MARINE...JLB
HYDROLOGY...KEC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 PM EDT MON SEP 8 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EDT MON SEP 8 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE NRN CONUS AND SRN CANADA. A SHORTWAVE TROUGH OVER WI AND
ASSOCIATED 700-300 MB QVECTOR CONV SUPPORTED SOME VERY LIGHT RAIN
SHOWERS OR SPINKLES OVER NRN WI INTO FAR WRN UPPER MI. WITH THE
FORCING MAINLY IN THE 500-300 MB LAYER AND RELATIVELY DRY LOW LEVELS
JUST MID LEVEL CLOUDS/CIGS WERE REPORTED WITH MOST STATIONS NOT EVEN
REPORTING ANY MEASURABLE AMOUNTS. OTHERWISE...PARLTY CLOUDY SKIES
WITH GUSTY SOUTH WINDS OF 15 TO 25 MPH PREVAILED OVER THE REST OF
THE CWA.
TONIGHT...EXPECT THE -SHRA/SPRINKLES OVER SW UPPER MI TO SLOWLY
SLIDE TO THE EAST THIS EVENING AS THE SHRTWV DEPARTS. THE LEFTOVER
MID CLOUDS SHOULD ALSO THIN OUT OVERNIGHT AS QVECTOR DIV SPREADS
INTO THE AREA. HOWEVER...WITH INCREASING SW FLOW 925-700 MB THETA-E
ADVECTION ADDITIONAL CLOUDS MAY SPREAD INTO THE WEST HALF LATE. THE
SRLY FLOW WILL KEEP MIN READINGS IN THE MID 50S INLAND TO AROUND 60
IN DOWNSLOPE LOCATIONS NEAR LAKE SUPERIOR.
TUESDAY...THE MODELS SUGGEST THAT A FRONTAL BOUNDARY WILL SLOWLY
DROP THROUGH WRN LAKE SUPERIOR AND AIDED BY THE LAKE BREEZE INTO THE
NW CWA BY AFTERNOON. THE COMBINATION OF THE APPROACHING FRONTAL
BOUNDARY...MLCAPE VALUES INTO THE 1K-2K RANGE...RELATIVELY WEAK
CAPPING AND THE POTENTIAL A WEAK SHORTWAVE BRUSHING THE AREA MAY
PRODUCE SOME ISOLD/SCT SHRA/TSRA BY MID TO LATE AFTERNOON OVER THE
WEST HALF. SINCE THE STRONGEST FORCING IS EXPECTED TO REMAIN NW OF
THE CWA...ONLY LOWER END CHANCE POPS WERE INCLUDED.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 441 AM EDT MON SEP 8 2014
THE MAIN THREATS THIS PERIOD WILL BE THE HEAVY RAIN TUESDAY NIGHT
THROUGH WEDNESDAY NIGHT...STRONG NORTHERLY WINDS LATE WEDNESDAY
AFTERNOON THROUGH WEDNESDAY NIGHT ALONG LAKE SUPERIOR...AND A
PROLONGED PERIOD OF COOL WEATHER STARTING THURSDAY WITH NEAR OR
BELOW FREEZING TEMPERATURES ANTICIPATED LATE FRIDAY NIGHT INTO EARLY
SATURDAY MORNING /COOLEST INLAND FROM THE GREAT LAKES/.
TUESDAY...
THE LAST DAY OF ABOVE NORMAL TEMPERATURES...OR EVEN NEAR NORMAL
TEMPERATURES FOR THE NEXT WEEK WILL BE TUESDAY. FAVORABLE S WINDS
OVER THE E HALF OF UPPER MI SHOULD ALLOW AREAS NEAR LAKE SUPERIOR TO
RISE INTO THE MID TO UPPER 70S...WITH LOW 70S COMMON ELSEWHERE. LOOK
FOR A SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE
W HALF OF THE CWA AS THE SFC TROUGH CONNECTING LOWS OVER CENTRAL
PLAINS AND HUDSON BAY SHIFTS ACROSS THE CWA. BROAD W TO SW FLOW
ALOFT WILL KEEP SWINGING DISTURBANCES ACROSS THE AREA AT 500MB.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
MODELS ARE COMING INTO BETTER AGREEMENT FOR THE TRACK OF THE SFC LOW
EJECTING NE OUT OF THE CENTRAL PLAINS TUESDAY NIGHT. LOOK FOR THE
SFC LOW TO BE SET UP ACROSS S MN AND IA AT 06Z TO SHIFT OVER S
CENTRAL UPPER MI/NE WI/N LAKE MI BY MID AFTERNOON. THIS WILL BRING
WIDESPREAD RAIN TO THE REGION. WITH PW VALUES RISING TO 1.5-2IN
HEAVY RAIN IS A CONCERN. CURRENTLY HAVE 1.5 TO JUST OVER 2IN OF RAIN
FCST FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. KEPT THE SMALL
CHANCE OF THUNDERSTORMS ALONG LAKE MI WEDNESDAY. WITH THE TRACK OF
THE SFC LOW...AND STRONG HIGH PRESSURE SET UP OVER CENTRAL AND S
ALBERTA/SASKATCHEWAN...STRONG N WINDS OF 40-45MPH WILL BE POSSIBLE
LATE WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...WITH THE
STRONGEST WINDS MOSTLY LIKELY ACROSS THE KEWEENAW PENINSULA. A WIND
ADVISORY MAY BE NEEDED FOR THE KEWEENAW PENINSULA. AS PREVIOUSLY
NOTED...EVEN IF WINDS DON/T QUITE REACH ADVISORY CRITERIA...TREES
COULD BE MORE SUSCEPTIBLE TO FALLING DUE TO THE SATURATED GROUND AND
PLENTY OF LEAVES ON THE TREES.
WEDNESDAY NIGHT THROUGH SUNDAY...
THE SFC LOW WILL SHIFT OVER ONTARIO AND QUEBEC WEDNESDAY
NIGHT...WITH THE SFC TROUGH LINGERING ACROSS UPPER MI INTO THURSDAY.
NW FLOW WILL BRING IN PLENTY OF COLD AIR BEHIND THE LOW...WITH
TEMPERATURES REMAINING WELL BELOW NORMAL THROUGH AT LEAST THE
UPCOMING WEEKEND. 850MB TEMPS OF -1C BY 18Z THURSDAY WILL RESULT IN
LAKE EFFECT RAIN WHICH WILL LINGER THROUGH FRIDAY AS A SECOND WAVE
AND TROUGH AXIS MORE ACROSS THE CWA THURSDAY NIGHT-FRIDAY.
HAVE ADDED THE POTENTIAL FOR NEAR OR BELOW FREEZING TEMPS INLAND
FROM THE GREAT LAKES...AND PRIMARILY OVER THE W HALF OF UPPER MI
LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING AS THE LARGE AREA OF
HIGH PRESSURE TO THE W BUILDS OVERHEAD WITH DECREASING CLOUDS. WINDS
WILL BECOME MORE W OR OUT OF THE S ON SATURDAY...EFFECTIVELY ENDING
OUR LAKE EFFECT CLOUDS OR SHOWERS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 130 PM EDT MON SEP 8 2014
EXPECT VFR CONDITIONS THROUGH MOST OF THIS FCST PERIOD WITH STRONG
SSW FLOW TAPPING RELATIVELY DRY AIR SHOWN ON THE 00Z MPX RAOB.
DAYTIME HEATING/MIXING WILL ALLOW FOR GUSTY WINDS TO 20-25 KT THIS
AFTERNOON BEFORE DECOUPLING THIS EVENING MIGHT ALLOW FOR SOME
MARGINAL LLWS BEFORE THE LLJ WEAKENS AFTER 06Z. LOW LEVEL MOISTURE
WILL INCREASE FROM THE SW TUE MORNING WITH MVFR CIGS LIKELY AT IWD
AND CMX AND POSSIBLY AT SAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EDT MON SEP 8 2014
SRLY WINDS TO 20 KNOTS WILL CONTINUE TONIGHT BETWEEN HIGH PRES OVER
NEW ENGLAND AND A TROUGH FROM NW ONTARIO INTO THE NRN PLAINS.
LOOK FOR THE TROUGH TO PUSH INTO LAKE SUPERIOR ON TUESDAY...WHILE A
STRONGER LOW ORGANIZES ACROSS THE CENTRAL PLAINS. EXPECT THE
DEEPENING LOW TO SHIFT NE ACROSS WI ON WEDNESDAY...AND ACROSS E
UPPER MI AND N LOWER MI LATE WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING...BEFORE CONTINUING NE INTO QUEBEC ON THURSDAY. A PERIOD OF
N GALES IS EXPECTED FROM WED MORNING THROUGH WED NIGHT. WINDS WILL
DIMINISH THU AS HIGH PRES BUILDS FROM THE PLAINS INTO THE WRN LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY EVENING
FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY MORNING FOR
LSZ243>245-264>267.
GALE WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY NIGHT
FOR LSZ162-240>242-263.
GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
LSZ248>251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
131 PM EDT MON SEP 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM EDT MON SEP 8 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT ZONAL FLOW
ALF ALONG THE CNDN BORDER. A SHRTWV RDG EMBEDDED IN THIS W-E FLOW IS
MOVING THRU THE UPR LKS EARLY THIS MRNG...SUPPORTING SFC HI PRES
OVER THE SE GREAT LKS. ACYC SW FLOW ARND THIS HI AND DRY AIRMASS
SHOWN ON LOCAL 00Z RAOBS...ESPECIALLY AT MPX WHERE THE 00Z PWAT IS
0.48 INCH OR 60 PCT OF NORMAL...ARE RESULTING IN MOCLR CONDITIONS
ACRS UPR MI. BUT HI CLDS ARE APRCHG WRN UPR MI IN ADVANCE OF A
SHRTWV MOVING E THRU THE NRN PLAINS IN THE SRN BRANCH FLOW. ANOTHER
SHRTWV WITHIN THE STRONGER NRN BRANCH IS PUSHING EWD THRU SRN
SASKATCHEWAN.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE WHETHER AND IF THEN HOW
QUICKLY SHOWERS SPREAD INTO UPR MI IN ADVANCE OF UPSTREAM SHRTWVS.
TODAY...SRN BRANCH DISTURBANCE IN THE NRN PLAINS EARLY THIS MRNG IS
PROGGED TO MOVE E AND INTO NRN WI BY 00Z TUE. ALTHOUGH UPR MI WL BE
ON THE FAVORED CYC SIDE OF THE TRACK OF THIS DISTURBANCE...
PERSISTENT SW FLOW ARND SFC HI PRES MOVING INTO NEW ENGLAND WL
ADVECT DRIER AIR FM THE SW AND THE DIRECTION OF MPX. SO ALTHOUGH
PVA/H5-3 QVECTOR CNVGC AHEAD OF THE SHRTWV IS FCST TO IMPACT MAINLY
THE S HALF OF UPR MI...MODELS INDICATE AN ABSENCE OF ANY SGNFT H85-5
QVECTOR CNVGC. THIS SETUP SUGGESTS THE MAIN IMPACT WL BE THE HI CLDS
SPILLING E FM MN. SO EVEN THOUGH SOME MODELS GENERATE PCPN NEAR THE
WI BORDER AFTER 18Z...OPTED TO MAINTAIN GOING DRY FCST. FCST H85
TEMPS RANGING FM ABOUT 11C OVER THE E TO 13C OVER THE W AND MIXING
TO H8-85 AS OBSVD UPSTREAM YDAY SUPPORTS HI TEMPS IN THE MID/UPR
70S. SSW FLOW OFF LK MI WL BRING COOLER WX TO THE ERN CWA. THE
DAYTIME HEATING/MIXING AND H925 WINDS IN THE 20-30KT RANGE WL RESULT
IN GUSTY WINDS BY LATE MRNG. GIVEN THE FVRBL CONDITIONS FOR GUSTY
WINDS...BUMPED UP FCST GUSTS A COUPLE OF KTS ABV WIND GUST PROCEDURE
OUTPUT.
TNGT...UPR MI IS FCST TO BE DOMINATED BY DEEP LYR QVECTOR DVGC BTWN
DEPARTING SRN BRANCH SHRTWV THRU NRN LOWER MI AND NRN BRANCH
DISTURBANCE CROSSING NW ONTARIO. SO ALTHOUGH THE PERSISTENT SW FLOW
BTWN THE HI PRES MOVING INTO THE CNDN MARITIMES AND AN APRCHG COLD
FNT ATTENDANT TO THE NRN BRANCH SHRTWV WL BRING A RETURN OF HIER H85
THETA E INTO THE UPR LKS...LINGERING MID LVL DRY AIR BEST SHOWN BY
THE 00Z GFS FCST SDNGS WARRANTS KEEPING THE GOING DRY FCST. STEADY
SW WIND AND INCRSG LLVL MSTR THAT MAY RESULT IN SOME SC ESPECIALLY
OVER THE W HALF CLOSER TO THE HIER H85 THETA E WL RESULT IN WELL ABV
NORMAL MIN TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 441 AM EDT MON SEP 8 2014
THE MAIN THREATS THIS PERIOD WILL BE THE HEAVY RAIN TUESDAY NIGHT
THROUGH WEDNESDAY NIGHT...STRONG NORTHERLY WINDS LATE WEDNESDAY
AFTERNOON THROUGH WEDNESDAY NIGHT ALONG LAKE SUPERIOR...AND A
PROLONGED PERIOD OF COOL WEATHER STARTING THURSDAY WITH NEAR OR
BELOW FREEZING TEMPERATURES ANTICIPATED LATE FRIDAY NIGHT INTO EARLY
SATURDAY MORNING /COOLEST INLAND FROM THE GREAT LAKES/.
TUESDAY...
THE LAST DAY OF ABOVE NORMAL TEMPERATURES...OR EVEN NEAR NORMAL
TEMPERATURES FOR THE NEXT WEEK WILL BE TUESDAY. FAVORABLE S WINDS
OVER THE E HALF OF UPPER MI SHOULD ALLOW AREAS NEAR LAKE SUPERIOR TO
RISE INTO THE MID TO UPPER 70S...WITH LOW 70S COMMON ELSEWHERE. LOOK
FOR A SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE
W HALF OF THE CWA AS THE SFC TROUGH CONNECTING LOWS OVER CENTRAL
PLAINS AND HUDSON BAY SHIFTS ACROSS THE CWA. BROAD W TO SW FLOW
ALOFT WILL KEEP SWINGING DISTURBANCES ACROSS THE AREA AT 500MB.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
MODELS ARE COMING INTO BETTER AGREEMENT FOR THE TRACK OF THE SFC LOW
EJECTING NE OUT OF THE CENTRAL PLAINS TUESDAY NIGHT. LOOK FOR THE
SFC LOW TO BE SET UP ACROSS S MN AND IA AT 06Z TO SHIFT OVER S
CENTRAL UPPER MI/NE WI/N LAKE MI BY MID AFTERNOON. THIS WILL BRING
WIDESPREAD RAIN TO THE REGION. WITH PW VALUES RISING TO 1.5-2IN
HEAVY RAIN IS A CONCERN. CURRENTLY HAVE 1.5 TO JUST OVER 2IN OF RAIN
FCST FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. KEPT THE SMALL
CHANCE OF THUNDERSTORMS ALONG LAKE MI WEDNESDAY. WITH THE TRACK OF
THE SFC LOW...AND STRONG HIGH PRESSURE SET UP OVER CENTRAL AND S
ALBERTA/SASKATCHEWAN...STRONG N WINDS OF 40-45MPH WILL BE POSSIBLE
LATE WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...WITH THE
STRONGEST WINDS MOSTLY LIKELY ACROSS THE KEWEENAW PENINSULA. A WIND
ADVISORY MAY BE NEEDED FOR THE KEWEENAW PENINSULA. AS PREVIOUSLY
NOTED...EVEN IF WINDS DON/T QUITE REACH ADVISORY CRITERIA...TREES
COULD BE MORE SUSCEPTIBLE TO FALLING DUE TO THE SATURATED GROUND AND
PLENTY OF LEAVES ON THE TREES.
WEDNESDAY NIGHT THROUGH SUNDAY...
THE SFC LOW WILL SHIFT OVER ONTARIO AND QUEBEC WEDNESDAY
NIGHT...WITH THE SFC TROUGH LINGERING ACROSS UPPER MI INTO THURSDAY.
NW FLOW WILL BRING IN PLENTY OF COLD AIR BEHIND THE LOW...WITH
TEMPERATURES REMAINING WELL BELOW NORMAL THROUGH AT LEAST THE
UPCOMING WEEKEND. 850MB TEMPS OF -1C BY 18Z THURSDAY WILL RESULT IN
LAKE EFFECT RAIN WHICH WILL LINGER THROUGH FRIDAY AS A SECOND WAVE
AND TROUGH AXIS MORE ACROSS THE CWA THURSDAY NIGHT-FRIDAY.
HAVE ADDED THE POTENTIAL FOR NEAR OR BELOW FREEZING TEMPS INLAND
FROM THE GREAT LAKES...AND PRIMARILY OVER THE W HALF OF UPPER MI
LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING AS THE LARGE AREA OF
HIGH PRESSURE TO THE W BUILDS OVERHEAD WITH DECREASING CLOUDS. WINDS
WILL BECOME MORE W OR OUT OF THE S ON SATURDAY...EFFECTIVELY ENDING
OUR LAKE EFFECT CLOUDS OR SHOWERS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 130 PM EDT MON SEP 8 2014
EXPECT VFR CONDITIONS THROUGH MOST OF THIS FCST PERIOD WITH STRONG
SSW FLOW TAPPING RELATIVELY DRY AIR SHOWN ON THE 00Z MPX RAOB.
DAYTIME HEATING/MIXING WILL ALLOW FOR GUSTY WINDS TO 20-25 KT THIS
AFTERNOON BEFORE DECOUPLING THIS EVENING MIGHT ALLOW FOR SOME
MARGINAL LLWS BEFORE THE LLJ WEAKENS AFTER 06Z. LOW LEVEL MOISTURE
WILL INCREASE FROM THE SW TUE MORNING WITH MVFR CIGS LIKELY AT IWD
AND CMX AND POSSIBLY AT SAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 332 AM EDT MON SEP 8 2014
FOG MAY CONTINUE TO BE A CONCERN INITIALLY OVER PORTIONS OF W AND
CENTRAL LAKE SUPERIOR. LAKE SUPERIOR WILL INITIALLY BE STUCK BETWEEN
EXITING HIGH PRESSURE OVER THE NEW ENGLAND STATES...AND A NEARING
TROUGH STRETCHING FROM NORTH DAKOTA THROUGH NORTHERN ONTARIO. LOOK
FOR THE TROUGH TO PUSH INTO LAKE SUPERIOR ON TUESDAY...WHILE A
STRONGER LOW ORGANIZES ACROSS THE CENTRAL PLAINS. EXPECT THE
DEEPENING LOW TO SHIFT NE ACROSS WI ON WEDNESDAY...AND ACROSS E
UPPER MI AND N LOWER MI LATE WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING...BEFORE CONTINUING NE INTO QUEBEC ON THURSDAY. A PERIOD OF
N GALES WILL BE POSSIBLE LATE TUESDAY NIGHT INTO EARLY THURSDAY. IN
LARGE HIGH PRESSURE OVER S ALBERTA AND SASKATCHEWAN THURSDAY IS
EXPECTED TO DIVE ACROSS THE N AND CENTRAL PLAINS...WHILE BUILDING A
RIDGE ACROSS LAKE SUPERIOR ON THURSDAY NIGHT AND FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...JLB
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
730 AM EDT MON SEP 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM EDT MON SEP 8 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT ZONAL FLOW
ALF ALONG THE CNDN BORDER. A SHRTWV RDG EMBEDDED IN THIS W-E FLOW IS
MOVING THRU THE UPR LKS EARLY THIS MRNG...SUPPORTING SFC HI PRES
OVER THE SE GREAT LKS. ACYC SW FLOW ARND THIS HI AND DRY AIRMASS
SHOWN ON LOCAL 00Z RAOBS...ESPECIALLY AT MPX WHERE THE 00Z PWAT IS
0.48 INCH OR 60 PCT OF NORMAL...ARE RESULTING IN MOCLR CONDITIONS
ACRS UPR MI. BUT HI CLDS ARE APRCHG WRN UPR MI IN ADVANCE OF A
SHRTWV MOVING E THRU THE NRN PLAINS IN THE SRN BRANCH FLOW. ANOTHER
SHRTWV WITHIN THE STRONGER NRN BRANCH IS PUSHING EWD THRU SRN
SASKATCHEWAN.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE WHETHER AND IF THEN HOW
QUICKLY SHOWERS SPREAD INTO UPR MI IN ADVANCE OF UPSTREAM SHRTWVS.
TODAY...SRN BRANCH DISTURBANCE IN THE NRN PLAINS EARLY THIS MRNG IS
PROGGED TO MOVE E AND INTO NRN WI BY 00Z TUE. ALTHOUGH UPR MI WL BE
ON THE FAVORED CYC SIDE OF THE TRACK OF THIS DISTURBANCE...
PERSISTENT SW FLOW ARND SFC HI PRES MOVING INTO NEW ENGLAND WL
ADVECT DRIER AIR FM THE SW AND THE DIRECTION OF MPX. SO ALTHOUGH
PVA/H5-3 QVECTOR CNVGC AHEAD OF THE SHRTWV IS FCST TO IMPACT MAINLY
THE S HALF OF UPR MI...MODELS INDICATE AN ABSENCE OF ANY SGNFT H85-5
QVECTOR CNVGC. THIS SETUP SUGGESTS THE MAIN IMPACT WL BE THE HI CLDS
SPILLING E FM MN. SO EVEN THOUGH SOME MODELS GENERATE PCPN NEAR THE
WI BORDER AFTER 18Z...OPTED TO MAINTAIN GOING DRY FCST. FCST H85
TEMPS RANGING FM ABOUT 11C OVER THE E TO 13C OVER THE W AND MIXING
TO H8-85 AS OBSVD UPSTREAM YDAY SUPPORTS HI TEMPS IN THE MID/UPR
70S. SSW FLOW OFF LK MI WL BRING COOLER WX TO THE ERN CWA. THE
DAYTIME HEATING/MIXING AND H925 WINDS IN THE 20-30KT RANGE WL RESULT
IN GUSTY WINDS BY LATE MRNG. GIVEN THE FVRBL CONDITIONS FOR GUSTY
WINDS...BUMPED UP FCST GUSTS A COUPLE OF KTS ABV WIND GUST PROCEDURE
OUTPUT.
TNGT...UPR MI IS FCST TO BE DOMINATED BY DEEP LYR QVECTOR DVGC BTWN
DEPARTING SRN BRANCH SHRTWV THRU NRN LOWER MI AND NRN BRANCH
DISTURBANCE CROSSING NW ONTARIO. SO ALTHOUGH THE PERSISTENT SW FLOW
BTWN THE HI PRES MOVING INTO THE CNDN MARITIMES AND AN APRCHG COLD
FNT ATTENDANT TO THE NRN BRANCH SHRTWV WL BRING A RETURN OF HIER H85
THETA E INTO THE UPR LKS...LINGERING MID LVL DRY AIR BEST SHOWN BY
THE 00Z GFS FCST SDNGS WARRANTS KEEPING THE GOING DRY FCST. STEADY
SW WIND AND INCRSG LLVL MSTR THAT MAY RESULT IN SOME SC ESPECIALLY
OVER THE W HALF CLOSER TO THE HIER H85 THETA E WL RESULT IN WELL ABV
NORMAL MIN TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 441 AM EDT MON SEP 8 2014
THE MAIN THREATS THIS PERIOD WILL BE THE HEAVY RAIN TUESDAY NIGHT
THROUGH WEDNESDAY NIGHT...STRONG NORTHERLY WINDS LATE WEDNESDAY
AFTERNOON THROUGH WEDNESDAY NIGHT ALONG LAKE SUPERIOR...AND A
PROLONGED PERIOD OF COOL WEATHER STARTING THURSDAY WITH NEAR OR
BELOW FREEZING TEMPERATURES ANTICIPATED LATE FRIDAY NIGHT INTO EARLY
SATURDAY MORNING /COOLEST INLAND FROM THE GREAT LAKES/.
TUESDAY...
THE LAST DAY OF ABOVE NORMAL TEMPERATURES...OR EVEN NEAR NORMAL
TEMPERATURES FOR THE NEXT WEEK WILL BE TUESDAY. FAVORABLE S WINDS
OVER THE E HALF OF UPPER MI SHOULD ALLOW AREAS NEAR LAKE SUPERIOR TO
RISE INTO THE MID TO UPPER 70S...WITH LOW 70S COMMON ELSEWHERE. LOOK
FOR A SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE
W HALF OF THE CWA AS THE SFC TROUGH CONNECTING LOWS OVER CENTRAL
PLAINS AND HUDSON BAY SHIFTS ACROSS THE CWA. BROAD W TO SW FLOW
ALOFT WILL KEEP SWINGING DISTURBANCES ACROSS THE AREA AT 500MB.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
MODELS ARE COMING INTO BETTER AGREEMENT FOR THE TRACK OF THE SFC LOW
EJECTING NE OUT OF THE CENTRAL PLAINS TUESDAY NIGHT. LOOK FOR THE
SFC LOW TO BE SET UP ACROSS S MN AND IA AT 06Z TO SHIFT OVER S
CENTRAL UPPER MI/NE WI/N LAKE MI BY MID AFTERNOON. THIS WILL BRING
WIDESPREAD RAIN TO THE REGION. WITH PW VALUES RISING TO 1.5-2IN
HEAVY RAIN IS A CONCERN. CURRENTLY HAVE 1.5 TO JUST OVER 2IN OF RAIN
FCST FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. KEPT THE SMALL
CHANCE OF THUNDERSTORMS ALONG LAKE MI WEDNESDAY. WITH THE TRACK OF
THE SFC LOW...AND STRONG HIGH PRESSURE SET UP OVER CENTRAL AND S
ALBERTA/SASKATCHEWAN...STRONG N WINDS OF 40-45MPH WILL BE POSSIBLE
LATE WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...WITH THE
STRONGEST WINDS MOSTLY LIKELY ACROSS THE KEWEENAW PENINSULA. A WIND
ADVISORY MAY BE NEEDED FOR THE KEWEENAW PENINSULA. AS PREVIOUSLY
NOTED...EVEN IF WINDS DON/T QUITE REACH ADVISORY CRITERIA...TREES
COULD BE MORE SUSCEPTIBLE TO FALLING DUE TO THE SATURATED GROUND AND
PLENTY OF LEAVES ON THE TREES.
WEDNESDAY NIGHT THROUGH SUNDAY...
THE SFC LOW WILL SHIFT OVER ONTARIO AND QUEBEC WEDNESDAY
NIGHT...WITH THE SFC TROUGH LINGERING ACROSS UPPER MI INTO THURSDAY.
NW FLOW WILL BRING IN PLENTY OF COLD AIR BEHIND THE LOW...WITH
TEMPERATURES REMAINING WELL BELOW NORMAL THROUGH AT LEAST THE
UPCOMING WEEKEND. 850MB TEMPS OF -1C BY 18Z THURSDAY WILL RESULT IN
LAKE EFFECT RAIN WHICH WILL LINGER THROUGH FRIDAY AS A SECOND WAVE
AND TROUGH AXIS MORE ACROSS THE CWA THURSDAY NIGHT-FRIDAY.
HAVE ADDED THE POTENTIAL FOR NEAR OR BELOW FREEZING TEMPS INLAND
FROM THE GREAT LAKES...AND PRIMARILY OVER THE W HALF OF UPPER MI
LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING AS THE LARGE AREA OF
HIGH PRESSURE TO THE W BUILDS OVERHEAD WITH DECREASING CLOUDS. WINDS
WILL BECOME MORE W OR OUT OF THE S ON SATURDAY...EFFECTIVELY ENDING
OUR LAKE EFFECT CLOUDS OR SHOWERS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 729 AM EDT MON SEP 8 2014
EXPECT VFR CONDITIONS THIS FCST PERIOD WITH STRONG SSW FLOW TAPPING
RELATIVELY DRY AIR SHOWN ON THE 00Z MPX RAOB. DAYTIME HEATING/MIXING
WL ALLOW FOR GUSTY WINDS TO 20-25 KT THIS AFTN BEFORE DECOUPLING
THIS EVNG CAUSES SOME MARGINAL LLWS BEFORE THE LLJ WEAKENS AFTER 06Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 332 AM EDT MON SEP 8 2014
FOG MAY CONTINUE TO BE A CONCERN INITIALLY OVER PORTIONS OF W AND
CENTRAL LAKE SUPERIOR. LAKE SUPERIOR WILL INITIALLY BE STUCK BETWEEN
EXITING HIGH PRESSURE OVER THE NEW ENGLAND STATES...AND A NEARING
TROUGH STRETCHING FROM NORTH DAKOTA THROUGH NORTHERN ONTARIO. LOOK
FOR THE TROUGH TO PUSH INTO LAKE SUPERIOR ON TUESDAY...WHILE A
STRONGER LOW ORGANIZES ACROSS THE CENTRAL PLAINS. EXPECT THE
DEEPENING LOW TO SHIFT NE ACROSS WI ON WEDNESDAY...AND ACROSS E
UPPER MI AND N LOWER MI LATE WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING...BEFORE CONTINUING NE INTO QUEBEC ON THURSDAY. A PERIOD OF
N GALES WILL BE POSSIBLE LATE TUESDAY NIGHT INTO EARLY THURSDAY. IN
LARGE HIGH PRESSURE OVER S ALBERTA AND SASKATCHEWAN THURSDAY IS
EXPECTED TO DIVE ACROSS THE N AND CENTRAL PLAINS...WHILE BUILDING A
RIDGE ACROSS LAKE SUPERIOR ON THURSDAY NIGHT AND FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
443 AM EDT MON SEP 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM EDT MON SEP 8 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT ZONAL FLOW
ALF ALONG THE CNDN BORDER. A SHRTWV RDG EMBEDDED IN THIS W-E FLOW IS
MOVING THRU THE UPR LKS EARLY THIS MRNG...SUPPORTING SFC HI PRES
OVER THE SE GREAT LKS. ACYC SW FLOW ARND THIS HI AND DRY AIRMASS
SHOWN ON LOCAL 00Z RAOBS...ESPECIALLY AT MPX WHERE THE 00Z PWAT IS
0.48 INCH OR 60 PCT OF NORMAL...ARE RESULTING IN MOCLR CONDITIONS
ACRS UPR MI. BUT HI CLDS ARE APRCHG WRN UPR MI IN ADVANCE OF A
SHRTWV MOVING E THRU THE NRN PLAINS IN THE SRN BRANCH FLOW. ANOTHER
SHRTWV WITHIN THE STRONGER NRN BRANCH IS PUSHING EWD THRU SRN
SASKATCHEWAN.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE WHETHER AND IF THEN HOW
QUICKLY SHOWERS SPREAD INTO UPR MI IN ADVANCE OF UPSTREAM SHRTWVS.
TODAY...SRN BRANCH DISTURBANCE IN THE NRN PLAINS EARLY THIS MRNG IS
PROGGED TO MOVE E AND INTO NRN WI BY 00Z TUE. ALTHOUGH UPR MI WL BE
ON THE FAVORED CYC SIDE OF THE TRACK OF THIS DISTURBANCE...
PERSISTENT SW FLOW ARND SFC HI PRES MOVING INTO NEW ENGLAND WL
ADVECT DRIER AIR FM THE SW AND THE DIRECTION OF MPX. SO ALTHOUGH
PVA/H5-3 QVECTOR CNVGC AHEAD OF THE SHRTWV IS FCST TO IMPACT MAINLY
THE S HALF OF UPR MI...MODELS INDICATE AN ABSENCE OF ANY SGNFT H85-5
QVECTOR CNVGC. THIS SETUP SUGGESTS THE MAIN IMPACT WL BE THE HI CLDS
SPILLING E FM MN. SO EVEN THOUGH SOME MODELS GENERATE PCPN NEAR THE
WI BORDER AFTER 18Z...OPTED TO MAINTAIN GOING DRY FCST. FCST H85
TEMPS RANGING FM ABOUT 11C OVER THE E TO 13C OVER THE W AND MIXING
TO H8-85 AS OBSVD UPSTREAM YDAY SUPPORTS HI TEMPS IN THE MID/UPR
70S. SSW FLOW OFF LK MI WL BRING COOLER WX TO THE ERN CWA. THE
DAYTIME HEATING/MIXING AND H925 WINDS IN THE 20-30KT RANGE WL RESULT
IN GUSTY WINDS BY LATE MRNG. GIVEN THE FVRBL CONDITIONS FOR GUSTY
WINDS...BUMPED UP FCST GUSTS A COUPLE OF KTS ABV WIND GUST PROCEDURE
OUTPUT.
TNGT...UPR MI IS FCST TO BE DOMINATED BY DEEP LYR QVECTOR DVGC BTWN
DEPARTING SRN BRANCH SHRTWV THRU NRN LOWER MI AND NRN BRANCH
DISTURBANCE CROSSING NW ONTARIO. SO ALTHOUGH THE PERSISTENT SW FLOW
BTWN THE HI PRES MOVING INTO THE CNDN MARITIMES AND AN APRCHG COLD
FNT ATTENDANT TO THE NRN BRANCH SHRTWV WL BRING A RETURN OF HIER H85
THETA E INTO THE UPR LKS...LINGERING MID LVL DRY AIR BEST SHOWN BY
THE 00Z GFS FCST SDNGS WARRANTS KEEPING THE GOING DRY FCST. STEADY
SW WIND AND INCRSG LLVL MSTR THAT MAY RESULT IN SOME SC ESPECIALLY
OVER THE W HALF CLOSER TO THE HIER H85 THETA E WL RESULT IN WELL ABV
NORMAL MIN TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 441 AM EDT MON SEP 8 2014
THE MAIN THREATS THIS PERIOD WILL BE THE HEAVY RAIN TUESDAY NIGHT
THROUGH WEDNESDAY NIGHT...STRONG NORTHERLY WINDS LATE WEDNESDAY
AFTERNOON THROUGH WEDNESDAY NIGHT ALONG LAKE SUPERIOR...AND A
PROLONGED PERIOD OF COOL WEATHER STARTING THURSDAY WITH NEAR OR
BELOW FREEZING TEMPERATURES ANTICIPATED LATE FRIDAY NIGHT INTO EARLY
SATURDAY MORNING /COOLEST INLAND FROM THE GREAT LAKES/.
TUESDAY...
THE LAST DAY OF ABOVE NORMAL TEMPERATURES...OR EVEN NEAR NORMAL
TEMPERATURES FOR THE NEXT WEEK WILL BE TUESDAY. FAVORABLE S WINDS
OVER THE E HALF OF UPPER MI SHOULD ALLOW AREAS NEAR LAKE SUPERIOR TO
RISE INTO THE MID TO UPPER 70S...WITH LOW 70S COMMON ELSEWHERE. LOOK
FOR A SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE
W HALF OF THE CWA AS THE SFC TROUGH CONNECTING LOWS OVER CENTRAL
PLAINS AND HUDSON BAY SHIFTS ACROSS THE CWA. BROAD W TO SW FLOW
ALOFT WILL KEEP SWINGING DISTURBANCES ACROSS THE AREA AT 500MB.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...
MODELS ARE COMING INTO BETTER AGREEMENT FOR THE TRACK OF THE SFC LOW
EJECTING NE OUT OF THE CENTRAL PLAINS TUESDAY NIGHT. LOOK FOR THE
SFC LOW TO BE SET UP ACROSS S MN AND IA AT 06Z TO SHIFT OVER S
CENTRAL UPPER MI/NE WI/N LAKE MI BY MID AFTERNOON. THIS WILL BRING
WIDESPREAD RAIN TO THE REGION. WITH PW VALUES RISING TO 1.5-2IN
HEAVY RAIN IS A CONCERN. CURRENTLY HAVE 1.5 TO JUST OVER 2IN OF RAIN
FCST FOR TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. KEPT THE SMALL
CHANCE OF THUNDERSTORMS ALONG LAKE MI WEDNESDAY. WITH THE TRACK OF
THE SFC LOW...AND STRONG HIGH PRESSURE SET UP OVER CENTRAL AND S
ALBERTA/SASKATCHEWAN...STRONG N WINDS OF 40-45MPH WILL BE POSSIBLE
LATE WEDNESDAY AFTERNOON THROUGH WEDNESDAY NIGHT...WITH THE
STRONGEST WINDS MOSTLY LIKELY ACROSS THE KEWEENAW PENINSULA. A WIND
ADVISORY MAY BE NEEDED FOR THE KEWEENAW PENINSULA. AS PREVIOUSLY
NOTED...EVEN IF WINDS DON/T QUITE REACH ADVISORY CRITERIA...TREES
COULD BE MORE SUSCEPTIBLE TO FALLING DUE TO THE SATURATED GROUND AND
PLENTY OF LEAVES ON THE TREES.
WEDNESDAY NIGHT THROUGH SUNDAY...
THE SFC LOW WILL SHIFT OVER ONTARIO AND QUEBEC WEDNESDAY
NIGHT...WITH THE SFC TROUGH LINGERING ACROSS UPPER MI INTO THURSDAY.
NW FLOW WILL BRING IN PLENTY OF COLD AIR BEHIND THE LOW...WITH
TEMPERATURES REMAINING WELL BELOW NORMAL THROUGH AT LEAST THE
UPCOMING WEEKEND. 850MB TEMPS OF -1C BY 18Z THURSDAY WILL RESULT IN
LAKE EFFECT RAIN WHICH WILL LINGER THROUGH FRIDAY AS A SECOND WAVE
AND TROUGH AXIS MORE ACROSS THE CWA THURSDAY NIGHT-FRIDAY.
HAVE ADDED THE POTENTIAL FOR NEAR OR BELOW FREEZING TEMPS INLAND
FROM THE GREAT LAKES...AND PRIMARILY OVER THE W HALF OF UPPER MI
LATE FRIDAY NIGHT INTO EARLY SATURDAY MORNING AS THE LARGE AREA OF
HIGH PRESSURE TO THE W BUILDS OVERHEAD WITH DECREASING CLOUDS. WINDS
WILL BECOME MORE W OR OUT OF THE S ON SATURDAY...EFFECTIVELY ENDING
OUR LAKE EFFECT CLOUDS OR SHOWERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 123 AM EDT MON SEP 8 2014
EXPECT VFR CONDITIONS THIS FCST PERIOD. DAYTIME HEATING/MIXING WL
ALLOW FOR GUSTY WINDS TO 15-20 KT MON AFTN AND WINDS WILL STAY UP
THROUGH MON EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 332 AM EDT MON SEP 8 2014
FOG MAY CONTINUE TO BE A CONCERN INITIALLY OVER PORTIONS OF W AND
CENTRAL LAKE SUPERIOR. LAKE SUPERIOR WILL INITIALLY BE STUCK BETWEEN
EXITING HIGH PRESSURE OVER THE NEW ENGLAND STATES...AND A NEARING
TROUGH STRETCHING FROM NORTH DAKOTA THROUGH NORTHERN ONTARIO. LOOK
FOR THE TROUGH TO PUSH INTO LAKE SUPERIOR ON TUESDAY...WHILE A
STRONGER LOW ORGANIZES ACROSS THE CENTRAL PLAINS. EXPECT THE
DEEPENING LOW TO SHIFT NE ACROSS WI ON WEDNESDAY...AND ACROSS E
UPPER MI AND N LOWER MI LATE WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING...BEFORE CONTINUING NE INTO QUEBEC ON THURSDAY. A PERIOD OF
N GALES WILL BE POSSIBLE LATE TUESDAY NIGHT INTO EARLY THURSDAY. IN
LARGE HIGH PRESSURE OVER S ALBERTA AND SASKATCHEWAN THURSDAY IS
EXPECTED TO DIVE ACROSS THE N AND CENTRAL PLAINS...WHILE BUILDING A
RIDGE ACROSS LAKE SUPERIOR ON THURSDAY NIGHT AND FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
333 AM EDT MON SEP 8 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM EDT MON SEP 8 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A SPLIT ZONAL FLOW
ALF ALONG THE CNDN BORDER. A SHRTWV RDG EMBEDDED IN THIS W-E FLOW IS
MOVING THRU THE UPR LKS EARLY THIS MRNG...SUPPORTING SFC HI PRES
OVER THE SE GREAT LKS. ACYC SW FLOW ARND THIS HI AND DRY AIRMASS
SHOWN ON LOCAL 00Z RAOBS...ESPECIALLY AT MPX WHERE THE 00Z PWAT IS
0.48 INCH OR 60 PCT OF NORMAL...ARE RESULTING IN MOCLR CONDITIONS
ACRS UPR MI. BUT HI CLDS ARE APRCHG WRN UPR MI IN ADVANCE OF A
SHRTWV MOVING E THRU THE NRN PLAINS IN THE SRN BRANCH FLOW. ANOTHER
SHRTWV WITHIN THE STRONGER NRN BRANCH IS PUSHING EWD THRU SRN
SASKATCHEWAN.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE WHETHER AND IF THEN HOW
QUICKLY SHOWERS SPREAD INTO UPR MI IN ADVANCE OF UPSTREAM SHRTWVS.
TODAY...SRN BRANCH DISTURBANCE IN THE NRN PLAINS EARLY THIS MRNG IS
PROGGED TO MOVE E AND INTO NRN WI BY 00Z TUE. ALTHOUGH UPR MI WL BE
ON THE FAVORED CYC SIDE OF THE TRACK OF THIS DISTURBANCE...
PERSISTENT SW FLOW ARND SFC HI PRES MOVING INTO NEW ENGLAND WL
ADVECT DRIER AIR FM THE SW AND THE DIRECTION OF MPX. SO ALTHOUGH
PVA/H5-3 QVECTOR CNVGC AHEAD OF THE SHRTWV IS FCST TO IMPACT MAINLY
THE S HALF OF UPR MI...MODELS INDICATE AN ABSENCE OF ANY SGNFT H85-5
QVECTOR CNVGC. THIS SETUP SUGGESTS THE MAIN IMPACT WL BE THE HI CLDS
SPILLING E FM MN. SO EVEN THOUGH SOME MODELS GENERATE PCPN NEAR THE
WI BORDER AFTER 18Z...OPTED TO MAINTAIN GOING DRY FCST. FCST H85
TEMPS RANGING FM ABOUT 11C OVER THE E TO 13C OVER THE W AND MIXING
TO H8-85 AS OBSVD UPSTREAM YDAY SUPPORTS HI TEMPS IN THE MID/UPR
70S. SSW FLOW OFF LK MI WL BRING COOLER WX TO THE ERN CWA. THE
DAYTIME HEATING/MIXING AND H925 WINDS IN THE 20-30KT RANGE WL RESULT
IN GUSTY WINDS BY LATE MRNG. GIVEN THE FVRBL CONDITIONS FOR GUSTY
WINDS...BUMPED UP FCST GUSTS A COUPLE OF KTS ABV WIND GUST PROCEDURE
OUTPUT.
TNGT...UPR MI IS FCST TO BE DOMINATED BY DEEP LYR QVECTOR DVGC BTWN
DEPARTING SRN BRANCH SHRTWV THRU NRN LOWER MI AND NRN BRANCH
DISTURBANCE CROSSING NW ONTARIO. SO ALTHOUGH THE PERSISTENT SW FLOW
BTWN THE HI PRES MOVING INTO THE CNDN MARITIMES AND AN APRCHG COLD
FNT ATTENDANT TO THE NRN BRANCH SHRTWV WL BRING A RETURN OF HIER H85
THETA E INTO THE UPR LKS...LINGERING MID LVL DRY AIR BEST SHOWN BY
THE 00Z GFS FCST SDNGS WARRANTS KEEPING THE GOING DRY FCST. STEADY
SW WIND AND INCRSG LLVL MSTR THAT MAY RESULT IN SOME SC ESPECIALLY
OVER THE W HALF CLOSER TO THE HIER H85 THETA E WL RESULT IN WELL ABV
NORMAL MIN TEMPS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM EDT SUN SEP 7 2014
MONDAY NIGHT INTO TUESDAY WILL BE THE TRANSITION PERIOD FROM THE
DRY AND RELATIVELY WARM HIGH PRESSURE DEPARTING THE AREA TO THE
MUCH COOLER AND WET PERIOD IN STORE FOR THE SECOND HALF OF THE WORK
WEEK. THE START OF THIS TRANSITION WILL BE A COLD FRONT EXTENDING
SOUTHWEST FROM A LOW NEAR HUDSON BAY. THIS FRONT WILL SLOWLY SHIFT
TO THE EAST OUT OF MINNESOTA ON MONDAY NIGHT AND INTO WESTERN LAKE
SUPERIOR AND THE WESTERN U.P. TUESDAY. EXPECT ISOLATED/SCATTERED
SHOWERS TO OCCUR ALONG THIS FRONT AS IT SLOWLY MOVES EAST ACROSS THE
U.P. LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT. DID CONTINUE TO
INCLUDE A SLIGHT CHANCE OF THUNDER ON THE EAST SIDE OF THE
FRONT/TROUGH DUE TO THE INSTABILITY INCREASING UNDER THE SOUTHERLY
FLOW DURING THE AFTERNOON BEFORE DIMINISHING IN THE EVENING.
THIS SLOW MOVING TROUGH WILL BE THE FOCUS FOR THE TRACK OF THE
STRONG LOW PRESSURE SYSTEM THAT WILL BE DEVELOPING IN THE CENTRAL
PLAINS ON TUESDAY AND THEN QUICKLY LIFTING NORTHEAST THROUGH THE
UPPER GREAT LAKES REGION WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT.
STILL SOME DIFFERENCES IN THE LOW TRACK BETWEEN THE OPERATIONAL
MEMBERS AND ITS LOCATION AT 00Z THURSDAY...BUT THE 00Z ECMWF OR 12Z
GEM RUNS SEEM TO BE A GOOD COMPROMISE WITH THE OTHER MODELS AND
ENSEMBLE MEMBERS. THIS CONSENSUS TRACKS A LOW-MID 990MB LOW FROM
SOUTHEAST MINNESOTA AT 12Z WEDNESDAY TO NORTHERN LAKE MICHIGAN BY
00Z THURSDAY AND INTO QUEBEC ON THURSDAY. 06Z GFS AND 00Z ECMWF
ENSEMBLE MEMBERS SUPPORT THAT IDEA AND AWAY FROM THE FASTER AND
FARTHER EAST SOLUTION SEEN ON THE 12Z GFS. WITH THAT IDEA IN
MIND...EXPECT A TRANSITION FROM THE LIGHTER PRECIP ASSOCIATED WITH
THE SURFACE TROUGH OVER WESTERN/CENTRAL U.P. ON TUESDAY NIGHT TO
WIDESPREAD RAIN LIFTING NORTHEAST ACROSS THE AREA ON WEDNESDAY.
WILL CONTINUE TO SHOW INCREASING POPS DURING THAT PERIOD AS THE
ISENTROPIC ASCENT PUSHES THROUGH THE AREA AND DECIDED UP THE
WEDNESDAY POPS TO DEFINITE VALUES ACROSS THE CWA. DID ADD A SMALL
POCKET OF THUNDER ALONG THE LAKE MICHIGAN BORDER WEDNESDAY WHERE THE
SURFACE LOW WILL TRACK AND POCKET OF ELEVATED INSTABILITY WOULD BE
LOCATED. AS THE LOW LIFTS NORTHEAST ON WEDNESDAY NIGHT...EXPECT THE
RAIN TO LINGER THE LONGEST OVER THE WEST AND ESPECIALLY THE KEWEENAW
PENINSULA WHICH WILL BE JUST TO THE WEST/NORTHWEST OF THE 850/700MB
LOW TRACK. WITH THE INITIAL SURGE OF PRECIPITATION ASSOCIATED WITH
THIS LOW...HAVE RAINFALL AMOUNTS OVER AN 1.25 INCH ACROSS THE ENTIRE
AREA THROUGH WEDNESDAY NIGHT AND THE HIGHEST AMOUNTS OVER NORTHWEST
UPPER MICHIGAN (AMOUNTS OF 1.5-2IN). IN ADDITION TO THE RAIN...WINDS
WILL BE ON THE INCREASE FROM WEST TO EAST WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT WITH SOLID NORTHERLY GALES OVER LAKE SUPERIOR.
EXPECT THE STRONG WINDS TO AFFECT THE SHORELINE AREAS WEDNESDAY
NIGHT (GUSTS TO 35KTS) BEFORE GRADUALLY DECREASING THURSDAY THROUGH
FRIDAY. HAVE WINDS RIGHT AROUND WIND ADVISORY CRITERIA OVER
NORTHERN PORTIONS OF THE KEWEENAW PENINSULA AND EVEN IF THEY DON/T
REACH CRITERIA...THERE COULD BE DECENT IMPACTS WITH A SATURATED
GROUND AND LEAVES ON THE TREES HELPING TO CAUSE SOME TREES TO FALL
DOWN.
THE NORTHWEST FLOW BEHIND THE LOW WILL USHER IN COLD AIR ALOFT (850
TEMPS OF -1C BY 18Z THURSDAY) AND LEAD TO LAKE EFFECT RAIN UNDER
NORTHWEST FLOW UNTIL THE SECOND WAVE AND TROUGH AXIS MOVES THROUGH
THURSDAY NIGHT INTO FRIDAY. THIS WILL BRING ANOTHER AREA OF
WIDESPREAD LIGHT RAIN SHOWERS TO THE AREA. BEHIND THAT SECOND
WAVE...EXPECT DRYING CONDITIONS AS AN UPPER/SURFACE RIDGE MOVE INTO
THE AREA THROUGH SUNDAY MORNING. DEPENDING ON HOW QUICKLY SKIES
CLEAR ON FRIDAY NIGHT...COULD SEE LOWS NEARING FREEZING. THINK
BEST CHANCE WOULD BE OVER THE INTERIOR WEST AS IS TRADITIONALLY
THE CASE WITH BACKING LOW LEVEL WINDS. THURSDAY THROUGH SATURDAY
WILL BE A COOL STRETCH AND EXPECT HIGHS TO BE IN THE 50S EACH DAY.
OVER THE WEST ON THURSDAY/FRIDAY...COULD SEE SOME LOCATIONS
STRUGGLING TO RISE OUT OF THE UPPER 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 123 AM EDT MON SEP 8 2014
EXPECT VFR CONDITIONS THIS FCST PERIOD. DAYTIME HEATING/MIXING WL
ALLOW FOR GUSTY WINDS TO 15-20 KT MON AFTN AND WINDS WILL STAY UP
THROUGH MON EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 332 AM EDT MON SEP 8 2014
FOG MAY CONTINUE TO BE A CONCERN INITIALLY OVER PORTIONS OF W AND
CENTRAL LAKE SUPERIOR. LAKE SUPERIOR WILL INITIALLY BE STUCK BETWEEN
EXITING HIGH PRESSURE OVER THE NEW ENGLAND STATES...AND A NEARING
TROUGH STRETCHING FROM NORTH DAKOTA THROUGH NORTHERN ONTARIO. LOOK
FOR THE TROUGH TO PUSH INTO LAKE SUPERIOR ON TUESDAY...WHILE A
STRONGER LOW ORGANIZES ACROSS THE CENTRAL PLAINS. EXPECT THE
DEEPENING LOW TO SHIFT NE ACROSS WI ON WEDNESDAY...AND ACROSS E
UPPER MI AND N LOWER MI LATE WEDNESDAY AFTERNOON INTO WEDNESDAY
EVENING...BEFORE CONTINUING NE INTO QUEBEC ON THURSDAY. A PERIOD OF
N GALES WILL BE POSSIBLE LATE TUESDAY NIGHT INTO EARLY THURSDAY. IN
LARGE HIGH PRESSURE OVER S ALBERTA AND SASKATCHEWAN THURSDAY IS
EXPECTED TO DIVE ACROSS THE N AND CENTRAL PLAINS...WHILE BUILDING A
RIDGE ACROSS LAKE SUPERIOR ON THURSDAY NIGHT AND FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...SRF
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
125 AM EDT MON SEP 8 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 358 PM EDT SUN SEP 7 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR LAKES BTWN A BROAD UPR RDG OVER WRN NAMERICA AND A TROF OVER
THE NE STATES. SHRTWV EMBEDDED IN THIS WNW FLOW WHICH WAS RESPONSIBLE
FOR CLOUD COVER AND ISOLD SHRA OVER ERN LAKE SUPERIOR HAS NOW MOVED
EAST OF LAKE SUPERIOR WITH CLOUD COVER GENERALLY ERODING. ANOTHER
SHORTWAVE MOVING EAST THROUGH SOUTH DAKOTA HAS GENERATED SOME WAA
CLOUDS OVER ERN SD BUT NO PCPN AT THIS TIME AS AIR MASS VERY DRY AS
NOTED ON 12Z ABR SNDG.
MAIN FCST CONCERNS WILL FOCUS MAINLY ON TEMPS AND CLOUDS AS AIRMASS
LOOKS TO BE TOO DRY FOR PCPN OVER THE NEXT 24 HRS.
TNGT...TIGHTENING PRES GRADIENT BTWN HI PRES RETREATING TOWARD NEW
ENGLAND AND LO PRES TAKING SHAPE SW OF LK WINNIPEG WILL ALLOW FOR AN
INCREASE IN SSW WIND ACROSS THE AREA TONIGHT. ALTHOUGH THE AIRMASS
WL BE DRY AND SKIES MOSTLY CLR WITH PWATS AROUND 0.75 INCH...THE
STEADY WIND WL TEND TO LIMIT THE DIURNAL TEMP DROP...ESPECIALLY IN
THE DOWNSLOPE AREAS NEAR LK SUP OVER NW UPR MI. EXPECT THE LOWEST
MIN TEMPS (MID TO UPPER 40S) OVER THE INTERIOR ALONG THE WI BDR AND
E WHERE THE PRES GRADIENT WL BE A BIT WEAKER/WINDS LIGHTER.
CONVERSELY MIN TEMPS FOR DOWNSLOPING AREAS ALONG LAKE SUPERIOR WILL
STAY UP IN THE MID TO UPPER 50S.
WAA WILL CONTINUE ON MONDAY WITH INCREASING S WINDS AS UPPER MI
REMAINS STUCK BETWEEN A LARGE AREA OF HIGH PRESSURE EXITING THE NEW
ENGLAND STATES...AND AN ELONGATED LOW PRES TROUGH SET UP FROM THE
CENTRAL PLAINS THROUGH ONTARIO AND HUDSON BAY. 850MB TEMPS WILL
AVERAGE 11-12C BY THE END OF THE DAY SHOULD YIELD HIGH TEMPS IN THE
MID TO UPPER 70S ACROSS THE AREA DESPITE SOME INCREASE IN WAA CLOUDS
AHEAD OF APPROACHING PLAINS SHORTWAVE. SOUTH GUSTS NEAR 20KTS WILL BE
COMMON IN THE AFTERNOON. GIVEN DRY AIRMASS IN PLACE HAVE ELECTED TO
KEEP FCST DRY FOR NOW DESPITE SOME WEAK FORCING AHEAD OF PLAINS
SHORTWAVE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM EDT SUN SEP 7 2014
MONDAY NIGHT INTO TUESDAY WILL BE THE TRANSITION PERIOD FROM THE
DRY AND RELATIVELY WARM HIGH PRESSURE DEPARTING THE AREA TO THE
MUCH COOLER AND WET PERIOD IN STORE FOR THE SECOND HALF OF THE WORK
WEEK. THE START OF THIS TRANSITION WILL BE A COLD FRONT EXTENDING
SOUTHWEST FROM A LOW NEAR HUDSON BAY. THIS FRONT WILL SLOWLY SHIFT
TO THE EAST OUT OF MINNESOTA ON MONDAY NIGHT AND INTO WESTERN LAKE
SUPERIOR AND THE WESTERN U.P. TUESDAY. EXPECT ISOLATED/SCATTERED
SHOWERS TO OCCUR ALONG THIS FRONT AS IT SLOWLY MOVES EAST ACROSS THE
U.P. LATE TUESDAY AFTERNOON INTO TUESDAY NIGHT. DID CONTINUE TO
INCLUDE A SLIGHT CHANCE OF THUNDER ON THE EAST SIDE OF THE
FRONT/TROUGH DUE TO THE INSTABILITY INCREASING UNDER THE SOUTHERLY
FLOW DURING THE AFTERNOON BEFORE DIMINISHING IN THE EVENING.
THIS SLOW MOVING TROUGH WILL BE THE FOCUS FOR THE TRACK OF THE
STRONG LOW PRESSURE SYSTEM THAT WILL BE DEVELOPING IN THE CENTRAL
PLAINS ON TUESDAY AND THEN QUICKLY LIFTING NORTHEAST THROUGH THE
UPPER GREAT LAKES REGION WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT.
STILL SOME DIFFERENCES IN THE LOW TRACK BETWEEN THE OPERATIONAL
MEMBERS AND ITS LOCATION AT 00Z THURSDAY...BUT THE 00Z ECMWF OR 12Z
GEM RUNS SEEM TO BE A GOOD COMPROMISE WITH THE OTHER MODELS AND
ENSEMBLE MEMBERS. THIS CONSENSUS TRACKS A LOW-MID 990MB LOW FROM
SOUTHEAST MINNESOTA AT 12Z WEDNESDAY TO NORTHERN LAKE MICHIGAN BY
00Z THURSDAY AND INTO QUEBEC ON THURSDAY. 06Z GFS AND 00Z ECMWF
ENSEMBLE MEMBERS SUPPORT THAT IDEA AND AWAY FROM THE FASTER AND
FARTHER EAST SOLUTION SEEN ON THE 12Z GFS. WITH THAT IDEA IN
MIND...EXPECT A TRANSITION FROM THE LIGHTER PRECIP ASSOCIATED WITH
THE SURFACE TROUGH OVER WESTERN/CENTRAL U.P. ON TUESDAY NIGHT TO
WIDESPREAD RAIN LIFTING NORTHEAST ACROSS THE AREA ON WEDNESDAY.
WILL CONTINUE TO SHOW INCREASING POPS DURING THAT PERIOD AS THE
ISENTROPIC ASCENT PUSHES THROUGH THE AREA AND DECIDED UP THE
WEDNESDAY POPS TO DEFINITE VALUES ACROSS THE CWA. DID ADD A SMALL
POCKET OF THUNDER ALONG THE LAKE MICHIGAN BORDER WEDNESDAY WHERE THE
SURFACE LOW WILL TRACK AND POCKET OF ELEVATED INSTABILITY WOULD BE
LOCATED. AS THE LOW LIFTS NORTHEAST ON WEDNESDAY NIGHT...EXPECT THE
RAIN TO LINGER THE LONGEST OVER THE WEST AND ESPECIALLY THE KEWEENAW
PENINSULA WHICH WILL BE JUST TO THE WEST/NORTHWEST OF THE 850/700MB
LOW TRACK. WITH THE INITIAL SURGE OF PRECIPITATION ASSOCIATED WITH
THIS LOW...HAVE RAINFALL AMOUNTS OVER AN 1.25 INCH ACROSS THE ENTIRE
AREA THROUGH WEDNESDAY NIGHT AND THE HIGHEST AMOUNTS OVER NORTHWEST
UPPER MICHIGAN (AMOUNTS OF 1.5-2IN). IN ADDITION TO THE RAIN...WINDS
WILL BE ON THE INCREASE FROM WEST TO EAST WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT WITH SOLID NORTHERLY GALES OVER LAKE SUPERIOR.
EXPECT THE STRONG WINDS TO AFFECT THE SHORELINE AREAS WEDNESDAY
NIGHT (GUSTS TO 35KTS) BEFORE GRADUALLY DECREASING THURSDAY THROUGH
FRIDAY. HAVE WINDS RIGHT AROUND WIND ADVISORY CRITERIA OVER
NORTHERN PORTIONS OF THE KEWEENAW PENINSULA AND EVEN IF THEY DON/T
REACH CRITERIA...THERE COULD BE DECENT IMPACTS WITH A SATURATED
GROUND AND LEAVES ON THE TREES HELPING TO CAUSE SOME TREES TO FALL
DOWN.
THE NORTHWEST FLOW BEHIND THE LOW WILL USHER IN COLD AIR ALOFT (850
TEMPS OF -1C BY 18Z THURSDAY) AND LEAD TO LAKE EFFECT RAIN UNDER
NORTHWEST FLOW UNTIL THE SECOND WAVE AND TROUGH AXIS MOVES THROUGH
THURSDAY NIGHT INTO FRIDAY. THIS WILL BRING ANOTHER AREA OF
WIDESPREAD LIGHT RAIN SHOWERS TO THE AREA. BEHIND THAT SECOND
WAVE...EXPECT DRYING CONDITIONS AS AN UPPER/SURFACE RIDGE MOVE INTO
THE AREA THROUGH SUNDAY MORNING. DEPENDING ON HOW QUICKLY SKIES
CLEAR ON FRIDAY NIGHT...COULD SEE LOWS NEARING FREEZING. THINK
BEST CHANCE WOULD BE OVER THE INTERIOR WEST AS IS TRADITIONALLY
THE CASE WITH BACKING LOW LEVEL WINDS. THURSDAY THROUGH SATURDAY
WILL BE A COOL STRETCH AND EXPECT HIGHS TO BE IN THE 50S EACH DAY.
OVER THE WEST ON THURSDAY/FRIDAY...COULD SEE SOME LOCATIONS
STRUGGLING TO RISE OUT OF THE UPPER 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 123 AM EDT MON SEP 8 2014
EXPECT VFR CONDITIONS THIS FCST PERIOD. DAYTIME HEATING/MIXING WL
ALLOW FOR GUSTY WINDS TO 15-20 KT MON AFTN AND WINDS WILL STAY UP
THROUGH MON EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EDT SUN SEP 7 2014
LARGE HIGH PRESSURE STRETCHING FROM THE CENTRAL PLAINS THROUGH THE
LOWER GREAT LAKES WILL EXIT TO THE NEW ENGLAND STATES TONIGHT.
MEANWHILE...A LOW PRES TROUGH WILL DEVELOP FROM HUDSON BAY THROUGH
WRN ONTARIO INTO THE NRN PLAINS. LOW PRES DEVELOPING OVER THE
CENTRAL PLAINS BY TUE WILL MOVE NE ACROSS THE UPPER GREAT LAKES LATE
WEDNESDAY AND WEDNESDAY NIGHT...BEFORE EXITING INTO QUEBEC ON
THURSDAY. A PERIOD OF N GALES WILL BE POSSIBLE LATE TUE
NIGHT INTO EARLY THURSDAY. INCLUDED AREAS OF FOG OVER NCNTRL LAKE
SUPERIOR WHERE PATCH OF FOG HAS RESIDED MUCH OF THE AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
343 PM CDT MON SEP 8 2014
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 333 PM CDT MON SEP 8 2014
MAIN FORECAST CHALLENGE FOR THE SHORT TERM IS SEVERE POTENTIAL
TUESDAY/TUESDAY EVENING...WITH TEMPERATURES BECOMING THE MAIN
ISSUE IN THE LONGER TERM.
SCATTERED SHOWERS/THUNDERSTORMS CONTINUE ACROSS PORTIONS OF OUR
NORTHEASTERN CWA AHEAD OF A VERY SUBTLE SHORTWAVE TROUGH MOVING
THROUGH THE WESTERLIES. THIS ACTIVITY SHOULD CONTINUE TO SHIFT
EAST WITH THE SHORTWAVE ENERGY THROUGH THE EVENING AND OVERNIGHT
HOURS. MOSTLY SUNNY CONDITIONS ACROSS THE REMAINDER OF THE CWA
HAVE ALLOWED A DIURNALLY DRIVEN CU FIELD TO DEVELOP. BOTH THE
LATEST HRRR AND THE RAP INDICATE SOME CONVECTIVE ACTIVITY
DEVELOPING OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA AFTER 00Z
ALONG THE THETA-E AXIS AND HAVE INCLUDED SOME LOW POPS TO ACCOUNT
FOR THIS THIS EVENING.
MAIN WEATHER CONCERN COMES ALONG WITH THE SHORTWAVE TROUGH CURRENTLY
ON THE NORTHERN CALIFORNIA COAST. THIS FEATURE WILL DEAMPLIFY AS IT
SLIDES EAST TOWARD COLORADO OVER THE NEXT 24 HOURS. AHEAD OF
THIS...A LEE CYCLONE WILL DEEPEN AND MOVE INTO SOUTHWESTERN KANSAS
BY 00Z WED. A WARM FRONT WILL EXTEND E/NE ACROSS KANSAS AND SHOULD
DRIFT INTO OUR SOUTHERN CWA BY MID AFTERNOON. ANY STORMS THAT
DEVELOP WITH THE INCREASING SFC CONVERGENCE NEAR THE FRONT SHOULD
QUICKLY GO SEVERE AND ROTATE WITH INCREASINGLY STRONG SHEAR
PROFILES. AREA CONTINUES TO BE OUTLOOKED IN A SLIGHT RISK IN THE
SWODY2. SOME UNCERTAINTY CONTINUES IN REGARDS TO ANY LATE MORNING/EARLY
AFTERNOON CONVECTIVE CHANCES AHEAD OF A WEAK LEAD SHORTWAVE
EJECTING OUT AHEAD OF THE MAIN TROUGH. WILL CONTINUE SOME SMALLER
POPS FOR THIS...BUT MAIN SEVERE POTENTIAL WILL BE LATE
AFTERNOON/EARLY EVENING. THUNDERSTORMS WILL CONTINUE TO BE
WIDESPREAD AHEAD OF THE APPROACHING SFC LOW AS IT SLIDES NORTHEAST
OVER THE CWA BY 06Z/WED. SOUTHWESTERLY 45-55KT LLVL JET THROUGH
THE EVENING HOURS SHOULD SUSTAIN THUNDERSTORMS AFTER DARK WHEN
HEAVY RAIN RATHER THAN SEVERE STORMS WILL BE A THREAT. PW`S
THROUGH THE EVENING DO APPROACH 2.50" DURING THIS TIME. BY
12Z/WED THE SFC LOW WILL BE CENTERED ACROSS NORTHERN IOWA WITH
SOME LINGERING ACTIVITY THROUGH WED MORNING BEHIND THE LOW.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 PM CDT MON SEP 8 2014
A DEEPENING UPPER TROUGH OVER WESTERN CANADA WILL DROP SOUTHEAST
INTO THE CENTRAL PLAINS LATER THIS WEEK BRINGING MUCH COLDER AIR
INTO THE REGION. IN FACT...WE MAY BE APPROACHING RECORD COLD
HIGHS...ESPECIALLY THURSDAY WHEN WE HAVE HIGHS FORECAST IN THE MID
TO UPPER 50S. COLD RAIN IS LOOKING MORE LIKELY ON THURSDAY
NIGHT/FRIDAY MORNING AHEAD OF A SHARPENING UPPER TROUGH. IF TIMING
REMAINS SIMILAR TO WHAT MODELS ARE INDICATING...THE RAIN SHOULD BE
OUT OF THE AREA BY FRIDAY AFTERNOON. THE FORECAST FOR THE WEEKEND
LOOKS DRY WITH SOME SLIGHT MODERATION IN TEMPERATURES.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1217 PM CDT MON SEP 8 2014
GENERALLY VFR CONDITIONS ARE EXPECTED ACROSS EASTERN NEBRASKA TAF
SITES THROUGH 18Z TUESDAY. SCATTERED SHOWERS IN NORTHEAST NEBRASKA
COULD AFFECT KOFK FOR A FEW HOURS THIS AFTERNOON. THEN THERE IS A
SMALL CHANCE THUNDERSTORMS COULD DEVELOP BY 00Z THIS EVENING...BUT
MOST OF THAT ACTIVITY IS EXPECTED TO FIRE SOUTHEAST OF KOMA AND
KLNK. AN INCREASE OF MID LEVEL CLOUDS IS EXPECTED LATE TONIGHT AND
TUESDAY AHEAD OF A STORM SYSTEM MOVING INTO THE PLAINS. WIDESPREAD
THUNDERSTORMS ARE FORECAST AFTER THE END OF THIS TAF CYCLE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1227 PM CDT MON SEP 8 2014
.UPDATE...
ISSUED AT 1217 PM CDT MON SEP 8 2014
PESKY SHOWERS CONTINUE ACROSS NORTHEAST NEBRASKA TIED TO A WEAK
WAVE IN MID LEVEL FLOW. PLENTY OF SUNSHINE OUTSIDE OF THESE
SHOWERS WAS ALLOWING INSTABILITY TO INCREASE ACROSS THE AREA EARLY
THIS AFTERNOON. WHILE SOME CAPPING WAS STILL IN PLACE...CONTINUED
EROSION COULD LEAD TO CONVECTIVE DEVELOPMENT IN PARTS OF EASTERN
NEBRASKA AND WESTERN IOWA LATE TODAY OR THIS EVENING. OUTFLOW FROM
EARLIER CONVECTION COULD PROVIDE A FOCUS FOR STORMS IN WEST
CENTRAL IOWA LATER TODAY...EXPANDING INTO SOUTHEAST NEBRASKA THIS
EVENING. WILL CONTINUE WITH OUR MENTION OF SLIGHT CHANCE FOR
STORMS TODAY IN THOSE AREAS. ANOTHER POTENTIAL BOUNDARY OF CONCERN
IS A WARM FRONT EXTENDING FROM NORTHEAST NEBRASKA TO NEAR NEBRASKA
CITY...WITH GUSTY SOUTH WINDS ON THE WARM SIDE OF THIS BOUNDARY
AND SOUTHEAST WINDS ON THE COOLER SIDE. WILL CONTINUE TO MONITOR
THESE AREAS FOR INCREASED POTENTIAL FOR STORMS TODAY AND THIS
EVENING.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 255 AM CDT MON SEP 8 2014
HOW FAR SOUTH INTO THE FA WILL MORNING CONVECTION MAKE IT AND
THEN HOW QUICKLY WILL CONVECTION DEVELOP ON TUESDAY MAIN FORECAST
FOCUS IN THE SHORT TERM...ALTHOUGH SEVERE WEATHER AND HEAVY RAIN
REMAIN IN THE PICTURE FOR LATE TUESDAY.
A MERGING THUNDERSTORM CLUSTER WAS WORKING TOWARD NERN NEBR AS OF
8Z BUT ALSO MOVING INTO MLCAPE VALUE AREAS THAT WERE LESS THAN
500 J/KG PER SPC MESO PAGE. THUS WOULD SUSPECT SOME WEAKENING ON
SE EDGE THIS MORNING WHICH WAS HINTED AT BY 05Z HRRR AND RAP WHICH
KEPT MOST OF THE PRECIP IN FAR NE ZONES OR EVEN NE OF THERE...AS
DID 00Z ECMWF. HOWEVER...THAT SAID CONVECTION WAS MAINTAINING ITS
STRENGTH ENOUGH TO DISCOUNT SHORT TERM MODELS TO SOME DEGREE AND
TO INCREASE POPS IN NERN ZONES THIS MORNING AND KEEP MENTION OF
THEM PER PREV FORECAST IN THE AFTN ALONG E OF MO RIVER. DON/T KNOW
IF IT WILL HOLD TOGETHER AND ROLL DOWN MO RIVER TO OMAHA...BUT
CAN/T RULE THAT OUT ATTM. ALSO SOME HINT BY NAM AND 4KM WRF THAT
SOME NEW DEVELOPMENT COULD OCCUR ON SW SIDE THIS MORNING AND THUS
LEFT IN SMALL POPS FARTHER SW THAN RAP/HRRR WOULD SUGGEST. STILL
COUNTING ON DEBRIS BEING MINIMAL ENOUGH THIS AFTN TO ALLOW MAX
TEMPS TO REACH 80 OR BETTER ALL BUT PERHAPS FAR NERN ZONES.
ALTHOUGH SOME SMALL POPS WERE MAINTAINED TONIGHT...STILL APPEARED
THAT MAIN CONVECTIVE AREAS WOULD EITHER BE TO OUR EAST ON NOSE OF
H85 THETAE RIDGE/JET OR TO OUR WEST AS UPPER TROUGH AND MID LEVEL
MOISTURE APPROACH. THIS MOISTURE...WITH H7 DWPTS FORECAST AT 8-10
DEG C PER NAM/GFS...COULD ALLOW CONVECTION TO START OR INCREASE
FAIRLY EARLY TUESDAY AFTN AND LEAD TO LOCALLY HEAVY RAIN BY
EVENING AS PWATS WILL BE HIGH AND TRAINING OF CELLS PROBABLE.
HOWEVER...A LOT COULD/WILL DEPEND ON INITIAL DEVELOPMENT AND
RESULTANT OUTFLOW OR DIFFERENTIAL HEATING AREAS AND WILL REFRAIN
FROM BLANKET HEAVY RAIN MENTION JUST YET. WITH GENERAL MODEL
CONSENSUS THAT SRN ZONES WOULD BE LAST TO GET WIDESPREAD
CONVECTIVE OVERTURNING...MAX TEMPS IN MID/UPPER 80S ARE POSSIBLE
THERE. ALTHOUGH TEMPS SHOULD BE COOLER FARTHER NORTH...REFRAINED
FROM LOWERING JUST YET AS MORE OF THE WIDESPREAD CONVECTION MAY
HOLD OFF TILL AFTN. POTENTIAL FOR SVR WEATHER ALSO CONTINUES
ESPECIALLY WITH NAM FORECAST HODOGRAPHS FAVORABLY CURVED AHEAD OF
PREFRONTAL TROUGH/COLD FRONT FM OMAHA SWD. LIKE WHERE HEAVIER RAIN
EVENTUALLY SETS UP...SEVERE WEATHER...MAINLY ANY TORNADO
POTENTIAL...TOO WILL BE INFLUENCED BY EARLIER DAY CONVECTION BUT
MENTION OF BOTH SVR+HEAVY RAIN WILL CONTINUE IN THE HWO.
STRONGER CONVECTION COULD LINGER WELL INTO TUESDAY EVENING AND
EVEN EARLY OVERNIGHT HOURS AS LOW LEVEL JET DOESN/T SHIFT SE OF
THE AREA TIL AFTER 06Z PER MODELS...ALTHOUGH STRONGEST AND HEAVY
RAIN THREAT BY MID EVENING SHOULD SHIFT MOSTLY TO SRN AND ERN
ZONES.
ALTHOUGH H85 COOLING WILL LAG DUE TO UPPER FLOW...LOWER LEVEL
COOL/DRY ADVECTION WAS FAIRLY DECENT AND WITH PLENTY OF LOW
CLOUDS LIKELY ON WEDNESDAY...ANY HEATING/RECOVERY WILL BE LIMITED.
GENERALLY TRIMMED BACK BOTH LOWS AND HIGHS. ALTHOUGH A GENERAL
TROUGHING CONTINUED ALOFT...FORCING WAS WEAK PER QG FORECAST FM
GFS AND NAM BY AFTN. SO ALTHOUGH SMALL POPS WERE LEFT IN FOR THE
MORNING WITH A DRY AFTN...MUCH OF ANY PRECIP SHOULD BE PRETTY
LIGHT OR POSSIBLY JUST DRIZZLE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 255 AM CDT MON SEP 8 2014
EXTENDED BEGINS QUITE COOL AS H85 TEMPS LOWER INTO LOW SINGLE
DIGITS THU AND EVEN DROP BELOW ZERO THU NIGHT AS REINFORCING UPPER
SHORTWAVE SENDS EVEN COLDER AIR ACROSS THE FA. THIS WAVE COULD
ALSO SPREAD LIGHT SHOWERS ACROSS THE AREA THU MAKING IT EVEN LESS
LIKELY TO MIX TO H85. THIS IN TURN COULD BRING EVEN COLDER MAX
TEMPS TO THE REGION THAN THIS FORECAST WILL CONTAIN...WHICH WERE
ALREADY NEAR OR BELOW COLDEST MAX TEMPS ON RECORD FOR SEPT 11 OF
58 IN LINCOLN...56 IN OMAHA AND 55 AT NORFOLK.
IF SKIES CLEAR QUICKLY ENOUGH THURSDAY LOWS COULD BE A CATEGORY
COOLER THAN THE GENERALLY 40-45 GOING BY FRIDAY MORNING AND WITH
SURFACE STILL IN VICINITY SAT MORNING MORE 30S COULD BE NEEDED IN
FUTURE FORECASTS THAT DAY AS WELL. OTHERWISE 00Z ECMWF INDICATED
TEMPERATURES SHOULD MODERATE NEXT WEEKEND ALONG WITH PRECIP
HOLDING OFF TILL NEXT WAVE SUN NIGHT. GFS WAS A LITTLE COOLER AND
SUGGESTIVE OF LIGHT PRECIP SAT AS UPPER TROUGH TO BEGIN WEEKEND
WAS A TOUCH MORE AMPLIFIED. FORECAST FOR NEXT SATURDAY AND SUNDAY
WAS KEPT DRY FOR NOW.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1217 PM CDT MON SEP 8 2014
GENERALLY VFR CONDITIONS ARE EXPECTED ACROSS EASTERN NEBRASKA TAF
SITES THROUGH 18Z TUESDAY. SCATTERED SHOWERS IN NORTHEAST NEBRASKA
COULD AFFECT KOFK FOR A FEW HOURS THIS AFTERNOON. THEN THERE IS A
SMALL CHANCE THUNDERSTORMS COULD DEVELOP BY 00Z THIS EVENING...BUT
MOST OF THAT ACTIVITY IS EXPECTED TO FIRE SOUTHEAST OF KOMA AND
KLNK. AN INCREASE OF MID LEVEL CLOUDS IS EXPECTED LATE TONIGHT AND
TUESDAY AHEAD OF A STORM SYSTEM MOVING INTO THE PLAINS. WIDESPREAD
THUNDERSTORMS ARE FORECAST AFTER THE END OF THIS TAF CYCLE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DERGAN
SHORT TERM...CHERMOK
LONG TERM...CHERMOK
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
701 AM CDT MON SEP 8 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 255 AM CDT MON SEP 8 2014
HOW FAR SOUTH INTO THE FA WILL MORNING CONVECTION MAKE IT AND
THEN HOW QUICKLY WILL CONVECTION DEVELOP ON TUESDAY MAIN FORECAST
FOCUS IN THE SHORT TERM...ALTHOUGH SEVERE WEATHER AND HEAVY RAIN
REMAIN IN THE PICTURE FOR LATE TUESDAY.
A MERGING THUNDERSTORM CLUSTER WAS WORKING TOWARD NERN NEBR AS OF
8Z BUT ALSO MOVING INTO MLCAPE VALUE AREAS THAT WERE LESS THAN
500 J/KG PER SPC MESO PAGE. THUS WOULD SUSPECT SOME WEAKENING ON
SE EDGE THIS MORNING WHICH WAS HINTED AT BY 05Z HRRR AND RAP WHICH
KEPT MOST OF THE PRECIP IN FAR NE ZONES OR EVEN NE OF THERE...AS
DID 00Z ECMWF. HOWEVER...THAT SAID CONVECTION WAS MAINTAINING ITS
STRENGTH ENOUGH TO DISCOUNT SHORT TERM MODELS TO SOME DEGREE AND
TO INCREASE POPS IN NERN ZONES THIS MORNING AND KEEP MENTION OF
THEM PER PREV FORECAST IN THE AFTN ALONG E OF MO RIVER. DON/T KNOW
IF IT WILL HOLD TOGETHER AND ROLL DOWN MO RIVER TO OMAHA...BUT
CAN/T RULE THAT OUT ATTM. ALSO SOME HINT BY NAM AND 4KM WRF THAT
SOME NEW DEVELOPMENT COULD OCCUR ON SW SIDE THIS MORNING AND THUS
LEFT IN SMALL POPS FARTHER SW THAN RAP/HRRR WOULD SUGGEST. STILL
COUNTING ON DEBRIS BEING MINIMAL ENOUGH THIS AFTN TO ALLOW MAX
TEMPS TO REACH 80 OR BETTER ALL BUT PERHAPS FAR NERN ZONES.
ALTHOUGH SOME SMALL POPS WERE MAINTAINED TONIGHT...STILL APPEARED
THAT MAIN CONVECTIVE AREAS WOULD EITHER BE TO OUR EAST ON NOSE OF
H85 THETAE RIDGE/JET OR TO OUR WEST AS UPPER TROUGH AND MID LEVEL
MOISTURE APPROACH. THIS MOISTURE...WITH H7 DWPTS FORECAST AT 8-10
DEG C PER NAM/GFS...COULD ALLOW CONVECTION TO START OR INCREASE
FAIRLY EARLY TUESDAY AFTN AND LEAD TO LOCALLY HEAVY RAIN BY
EVENING AS PWATS WILL BE HIGH AND TRAINING OF CELLS PROBABLE.
HOWEVER...A LOT COULD/WILL DEPEND ON INITIAL DEVELOPMENT AND
RESULTANT OUTFLOW OR DIFFERENTIAL HEATING AREAS AND WILL REFRAIN
FROM BLANKET HEAVY RAIN MENTION JUST YET. WITH GENERAL MODEL
CONSENSUS THAT SRN ZONES WOULD BE LAST TO GET WIDESPREAD
CONVECTIVE OVERTURNING...MAX TEMPS IN MID/UPPER 80S ARE POSSIBLE
THERE. ALTHOUGH TEMPS SHOULD BE COOLER FARTHER NORTH...REFRAINED
FROM LOWERING JUST YET AS MORE OF THE WIDESPREAD CONVECTION MAY
HOLD OFF TILL AFTN. POTENTIAL FOR SVR WEATHER ALSO CONTINUES
ESPECIALLY WITH NAM FORECAST HODOGRAPHS FAVORABLY CURVED AHEAD OF
PREFRONTAL TROUGH/COLD FRONT FM OMAHA SWD. LIKE WHERE HEAVIER RAIN
EVENTUALLY SETS UP...SEVERE WEATHER...MAINLY ANY TORNADO
POTENTIAL...TOO WILL BE INFLUENCED BY EARLIER DAY CONVECTION BUT
MENTION OF BOTH SVR+HEAVY RAIN WILL CONTINUE IN THE HWO.
STRONGER CONVECTION COULD LINGER WELL INTO TUESDAY EVENING AND
EVEN EARLY OVERNIGHT HOURS AS LOW LEVEL JET DOESN/T SHIFT SE OF
THE AREA TIL AFTER 06Z PER MODELS...ALTHOUGH STRONGEST AND HEAVY
RAIN THREAT BY MID EVENING SHOULD SHIFT MOSTLY TO SRN AND ERN
ZONES.
ALTHOUGH H85 COOLING WILL LAG DUE TO UPPER FLOW...LOWER LEVEL
COOL/DRY ADVECTION WAS FAIRLY DECENT AND WITH PLENTY OF LOW
CLOUDS LIKELY ON WEDNESDAY...ANY HEATING/RECOVERY WILL BE LIMITED.
GENERALLY TRIMMED BACK BOTH LOWS AND HIGHS. ALTHOUGH A GENERAL
TROUGHING CONTINUED ALOFT...FORCING WAS WEAK PER QG FORECAST FM
GFS AND NAM BY AFTN. SO ALTHOUGH SMALL POPS WERE LEFT IN FOR THE
MORNING WITH A DRY AFTN...MUCH OF ANY PRECIP SHOULD BE PRETTY
LIGHT OR POSSIBLY JUST DRIZZLE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 255 AM CDT MON SEP 8 2014
EXTENDED BEGINS QUITE COOL AS H85 TEMPS LOWER INTO LOW SINGLE
DIGITS THU AND EVEN DROP BELOW ZERO THU NIGHT AS REINFORCING UPPER
SHORTWAVE SENDS EVEN COLDER AIR ACROSS THE FA. THIS WAVE COULD
ALSO SPREAD LIGHT SHOWERS ACROSS THE AREA THU MAKING IT EVEN LESS
LIKELY TO MIX TO H85. THIS IN TURN COULD BRING EVEN COLDER MAX
TEMPS TO THE REGION THAN THIS FORECAST WILL CONTAIN...WHICH WERE
ALREADY NEAR OR BELOW COLDEST MAX TEMPS ON RECORD FOR SEPT 11 OF
58 IN LINCOLN...56 IN OMAHA AND 55 AT NORFOLK.
IF SKIES CLEAR QUICKLY ENOUGH THURSDAY LOWS COULD BE A CATEGORY
COOLER THAN THE GENERALLY 40-45 GOING BY FRIDAY MORNING AND WITH
SURFACE STILL IN VICINITY SAT MORNING MORE 30S COULD BE NEEDED IN
FUTURE FORECASTS THAT DAY AS WELL. OTHERWISE 00Z ECMWF INDICATED
TEMPERATURES SHOULD MODERATE NEXT WEEKEND ALONG WITH PRECIP
HOLDING OFF TILL NEXT WAVE SUN NIGHT. GFS WAS A LITTLE COOLER AND
SUGGESTIVE OF LIGHT PRECIP SAT AS UPPER TROUGH TO BEGIN WEEKEND
WAS A TOUCH MORE AMPLIFIED. FORECAST FOR NEXT SATURDAY AND SUNDAY
WAS KEPT DRY FOR NOW.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 655 AM CDT MON SEP 8 2014
PRIMARY AREA OF CONVECTION IS EXPECTED TO REMAIN NORTH AND EAST OF
TAF SITES THROUGH 18Z. MID LEVEL VFR CIGS LIKELY DURING THIS TIME
AT BOTH KOFK AND KOMA. VFR CONDITIONS SHOULD PREVAIL THROUGH THE
PERIOD. SOME CHANCE OF MORE STORMS MOVING IN FROM THE SOUTH AFTER
06Z ESPECIALLY AT KLNK AS NEXT POCKET OF INSTABILITY LIFTS NORTH
WITH THE WARM FRONT. NO MENTION AT THIS TIME DUE TO UNCERTAINTY
SO LATE IN THE PERIOD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...CHERMOK
LONG TERM...CHERMOK
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
304 AM CDT MON SEP 8 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 255 AM CDT MON SEP 8 2014
HOW FAR SOUTH INTO THE FA WILL MORNING CONVECTION MAKE IT AND
THEN HOW QUICKLY WILL CONVECTION DEVELOP ON TUESDAY MAIN FORECAST
FOCUS IN THE SHORT TERM...ALTHOUGH SEVERE WEATHER AND HEAVY RAIN
REMAIN IN THE PICTURE FOR LATE TUESDAY.
A MERGING THUNDERSTORM CLUSTER WAS WORKING TOWARD NERN NEBR AS OF
8Z BUT ALSO MOVING INTO MLCAPE VALUE AREAS THAT WERE LESS THAN
500 J/KG PER SPC MESO PAGE. THUS WOULD SUSPECT SOME WEAKENING ON
SE EDGE THIS MORNING WHICH WAS HINTED AT BY 05Z HRRR AND RAP WHICH
KEPT MOST OF THE PRECIP IN FAR NE ZONES OR EVEN NE OF THERE...AS
DID 00Z ECMWF. HOWEVER...THAT SAID CONVECTION WAS MAINTAINING ITS
STRENGTH ENOUGH TO DISCOUNT SHORT TERM MODELS TO SOME DEGREE AND
TO INCREASE POPS IN NERN ZONES THIS MORNING AND KEEP MENTION OF
THEM PER PREV FORECAST IN THE AFTN ALONG E OF MO RIVER. DON/T KNOW
IF IT WILL HOLD TOGETHER AND ROLL DOWN MO RIVER TO OMAHA...BUT
CAN/T RULE THAT OUT ATTM. ALSO SOME HINT BY NAM AND 4KM WRF THAT
SOME NEW DEVELOPMENT COULD OCCUR ON SW SIDE THIS MORNING AND THUS
LEFT IN SMALL POPS FARTHER SW THAN RAP/HRRR WOULD SUGGEST. STILL
COUNTING ON DEBRIS BEING MINIMAL ENOUGH THIS AFTN TO ALLOW MAX
TEMPS TO REACH 80 OR BETTER ALL BUT PERHAPS FAR NERN ZONES.
ALTHOUGH SOME SMALL POPS WERE MAINTAINED TONIGHT...STILL APPEARED
THAT MAIN CONVECTIVE AREAS WOULD EITHER BE TO OUR EAST ON NOSE OF
H85 THETAE RIDGE/JET OR TO OUR WEST AS UPPER TROUGH AND MID LEVEL
MOISTURE APPROACH. THIS MOISTURE...WITH H7 DWPTS FORECAST AT 8-10
DEG C PER NAM/GFS...COULD ALLOW CONVECTION TO START OR INCREASE
FAIRLY EARLY TUESDAY AFTN AND LEAD TO LOCALLY HEAVY RAIN BY
EVENING AS PWATS WILL BE HIGH AND TRAINING OF CELLS PROBABLE.
HOWEVER...A LOT COULD/WILL DEPEND ON INITIAL DEVELOPMENT AND
RESULTANT OUTFLOW OR DIFFERENTIAL HEATING AREAS AND WILL REFRAIN
FROM BLANKET HEAVY RAIN MENTION JUST YET. WITH GENERAL MODEL
CONSENSUS THAT SRN ZONES WOULD BE LAST TO GET WIDESPREAD
CONVECTIVE OVERTURNING...MAX TEMPS IN MID/UPPER 80S ARE POSSIBLE
THERE. ALTHOUGH TEMPS SHOULD BE COOLER FARTHER NORTH...REFRAINED
FROM LOWERING JUST YET AS MORE OF THE WIDESPREAD CONVECTION MAY
HOLD OFF TILL AFTN. POTENTIAL FOR SVR WEATHER ALSO CONTINUES
ESPECIALLY WITH NAM FORECAST HODOGRAPHS FAVORABLY CURVED AHEAD OF
PREFRONTAL TROUGH/COLD FRONT FM OMAHA SWD. LIKE WHERE HEAVIER RAIN
EVENTUALLY SETS UP...SEVERE WEATHER...MAINLY ANY TORNADO
POTENTIAL...TOO WILL BE INFLUENCED BY EARLIER DAY CONVECTION BUT
MENTION OF BOTH SVR+HEAVY RAIN WILL CONTINUE IN THE HWO.
STRONGER CONVECTION COULD LINGER WELL INTO TUESDAY EVENING AND
EVEN EARLY OVERNIGHT HOURS AS LOW LEVEL JET DOESN/T SHIFT SE OF
THE AREA TIL AFTER 06Z PER MODELS...ALTHOUGH STRONGEST AND HEAVY
RAIN THREAT BY MID EVENING SHOULD SHIFT MOSTLY TO SRN AND ERN
ZONES.
ALTHOUGH H85 COOLING WILL LAG DUE TO UPPER FLOW...LOWER LEVEL
COOL/DRY ADVECTION WAS FAIRLY DECENT AND WITH PLENTY OF LOW
CLOUDS LIKELY ON WEDNESDAY...ANY HEATING/RECOVERY WILL BE LIMITED.
GENERALLY TRIMMED BACK BOTH LOWS AND HIGHS. ALTHOUGH A GENERAL
TROUGHING CONTINUED ALOFT...FORCING WAS WEAK PER QG FORECAST FM
GFS AND NAM BY AFTN. SO ALTHOUGH SMALL POPS WERE LEFT IN FOR THE
MORNING WITH A DRY AFTN...MUCH OF ANY PRECIP SHOULD BE PRETTY
LIGHT OR POSSIBLY JUST DRIZZLE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 255 AM CDT MON SEP 8 2014
EXTENDED BEGINS QUITE COOL AS H85 TEMPS LOWER INTO LOW SINGLE
DIGITS THU AND EVEN DROP BELOW ZERO THU NIGHT AS REINFORCING UPPER
SHORTWAVE SENDS EVEN COLDER AIR ACROSS THE FA. THIS WAVE COULD
ALSO SPREAD LIGHT SHOWERS ACROSS THE AREA THU MAKING IT EVEN LESS
LIKELY TO MIX TO H85. THIS IN TURN COULD BRING EVEN COLDER MAX
TEMPS TO THE REGION THAN THIS FORECAST WILL CONTAIN...WHICH WERE
ALREADY NEAR OR BELOW COLDEST MAX TEMPS ON RECORD FOR SEPT 11 OF
58 IN LINCOLN...56 IN OMAHA AND 55 AT NORFOLK.
IF SKIES CLEAR QUICKLY ENOUGH THURSDAY LOWS COULD BE A CATEGORY
COOLER THAN THE GENERALLY 40-45 GOING BY FRIDAY MORNING AND WITH
SURFACE STILL IN VICINITY SAT MORNING MORE 30S COULD BE NEEDED IN
FUTURE FORECASTS THAT DAY AS WELL. OTHERWISE 00Z ECMWF INDICATED
TEMPERATURES SHOULD MODERATE NEXT WEEKEND ALONG WITH PRECIP
HOLDING OFF TILL NEXT WAVE SUN NIGHT. GFS WAS A LITTLE COOLER AND
SUGGESTIVE OF LIGHT PRECIP SAT AS UPPER TROUGH TO BEGIN WEEKEND
WAS A TOUCH MORE AMPLIFIED. FORECAST FOR NEXT SATURDAY AND SUNDAY
WAS KEPT DRY FOR NOW.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1145 PM CDT SUN SEP 7 2014
VFR CONDS ARE STILL EXPECTED THROUGH THE PERIOD. THERE REMAINS AN
ISO CHC OF A SHRA/TSRA LATE TONIGHT AND INTO MON MRNG AT MAINLY
KOFK/KOMA BUT THREAT IS TO LOW TO INCLUDE IN THE TAFS ATTM.
OTHERWISE SOUTH WINDS ARE STILL EXPECTED TO INCREASE ON MON WITH
GUSTS AT ALL 3 SITES. WINDS WILL DIMINISH BY MON EVENING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...CHERMOK
LONG TERM...CHERMOK
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
325 PM EDT MON SEP 8 2014
.SYNOPSIS...
WET WEATHER WILL CONTINUE OVERNIGHT AS LOW PRESSURE DRAGS MORE
TROPICAL MOISTURE UP ALONG A STALLED FRONT. DRIER AIR WILL FINALLY
ARRIVE ON TUESDAY AS LOW PRESSURE MOVES FURTHER UP THE MID-ATLANTIC
COAST. WARMER TEMPERATURES AND DRY WEATHER ARE EXPECTED WEDNESDAY
AND THURSDAY. A STRONG COLD FRONT WILL ARRIVE LATE WEEK. THE FRONT
WILL MOVE INTO THE REGION BY THE WEEKEND BEFORE DRIFTING SOUTH
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 3 PM MONDAY...WEAK LOW PRESSURE IS VERY SLOWLY MOVING
NORTHEASTWARD ALONG A FRONT STALLED NEAR INTERSTATE 95. THE LOW
APPEARS TO BE LOCATED NEAR DILLON AND SHOULD MOVE TOWARD
FAYETTEVILLE OVER THE NEXT 3 HOURS. WHILE THIS WILL REMOVE THE
STRONGEST LOW-LEVEL CONVERGENCE AND FOCUS FOR SHOWERS...WE STILL
HAVE A DEEP SOUTHERLY FLOW OF MOISTURE TO DEAL WITH. PRECIPITABLE
WATER VALUES REMAIN 2.2 INCHES INLAND TO 2.4 INCHES ALONG THE COAST.
GIVEN COOL SURFACE TEMPERATURES THE BULK OF OUR INSTABILITY IS
ELEVATED...500 J/KG INLAND TO NEAR 1000 J/KG AT THE COAST.
MODERATE TO HEAVY RAIN WILL CONTINUE ACROSS INTERIOR SE NORTH
CAROLINA AND NEARBY PORTIONS OF INTERIOR NE SOUTH CAROLINA FOR THE
NEXT FEW HOURS. THE FOCUS FOR HEAVY RAIN AFTER DARK WILL PROBABLY
SHIFT OFFSHORE SOUTH OF OAK ISLAND...ADVECTING BACK ONSHORE IN THE
DEEP SOUTHERLY FLOW. FOR THIS REASON WE WILL MAINTAIN THE FLOOD
WATCH FROM LUMBERTON AND DILLON EASTWARD TOWARD SOUTHPORT AND
WILMINGTON. SOILS ARE SATURATED OVER MOST OF THE WATCH AREA AND ANY
SUSTAINED HEAVY RAINFALL WILL CREATE A FLOODING RISK. WE HAVE
RECEIVED SEVERAL PUBLIC REPORTS VIA FACEBOOK AND PHONE OF 5+ INCHES
OF RAIN MEASURED ACROSS NORTHEASTERN NEW HANOVER COUNTY SO FAR IN
THIS EVENT.
MODELS HAVE COME INTO BETTER AGREEMENT WITH HOW THE EVENT ENDS
TONIGHT...ALTHOUGH THE LAST SEVERAL HRRR RUNS ARE MUCH FASTER WITH
CLEARING THE BACK EDGE OF THE PRECIP OFF THE COAST THAN ANY OF THE
SYNOPTIC GUIDANCE. (GFS, NAM, ECMWF) BY 8 PM I WOULD EXPECT MOST OF
THE RAIN TO HAVE ENDED WEST OF I-95 EXCEPT NEAR LUMBERTON...AND BY
MIDNIGHT THE BACK EDGE OF PRECIP WILL PROBABLY BE THROUGH MYRTLE
BEACH AND WHITEVILLE. IT MAY TAKE UNTIL SUNRISE FOR RAIN TO END IN
WILMINGTON HOWEVER AS THE EASTWARD PROGRESSION OF THE MID-LEVEL
TROUGH BECOMES QUITE SLOW.
LOWS SHOULD RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S NEAR
THE COAST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...LOW PRESSURE WILL BE DEPARTING NORTHEAST TUE
MORNING WITH MID LEVEL DRY AIR MOVING IN FROM THE WEST-NORTHWEST.
THIS SHOULD BRING ABOUT A FAIRLY QUICK END TO ANY LINGER PRECIP TUE
MORNING FOR INLAND SITES. ALONG THE COAST MEASURABLE PRECIP MAY HANG
ON INTO EARLY AFTERNOON WITH LOW LEVEL MOISTURE TRAPPED UNDER MID
LEVEL SUBSIDENCE IN THE WAKE OF THE LOW AND ASSOCIATED WITH THE
SLOWLY EXPANDING SOUTHERN CONUS 5H RIDGE. CLOUD COVER WILL ALSO
LINGER ACROSS THE AREA TUE. GRADUAL CLEARING WILL OCCUR FROM WEST TO
EAST IN THE AFTERNOON BUT THE NC COAST IS LIKELY TO REMAIN CLOUDY
THROUGH SUNSET. TEMPERATURES WILL BE A MIXED BAG WITH INLAND AREAS
RUNNING WARMER DUE TO BREAKS OF SUN LATER IN THE DAY AND SUBTLE
HEIGHT INCREASES. ALONG THE COAST HIGHS WILL BE NEAR TO SLIGHTLY
BELOW CLIMO. CLEARING LATE TUE NIGHT COULD ALLOW FOR A PERIOD OF LOW
STRATUS OR FOG JUST BEFORE DAYBREAK. LATE CLOUD/FOG WILL HELP KEEP
LOWS NEAR CLIMO TUE NIGHT.
MODIFIED HIGH PRESSURE WILL BUILD IN FROM THE WEST ON WED AS MID
LEVEL RIDGE OVER THE SOUTH CONTINUES TO EXPAND EAST. FORECAST
SOUNDINGS SHOW DEEP DRY AIR BUILDING IN...WHICH SHOULD PRODUCE
PARTLY TO MOSTLY SUNNY SKIES. DEEP DRY AIR ALONG WITH WESTERLY FLOW
ALOFT AND LOW LEVEL NORTHEAST FLOW WILL PREVENT DEVELOPMENT OF ANY
MEANINGFUL CONVECTION WED AND PRECIP CHANCES WILL BE NEAR ZERO.
AFOREMENTIONED NORTHEAST FLOW IN THE BOUNDARY LAYER WILL KEEP HIGHS
ALONG THE COAST A LITTLE COOLER...THOUGH STILL ABOVE CLIMO. TEMPS
WED AFTERNOON WILL RANGE FROM LOW 90S INLAND SC TO MID 80S ALONG THE
NC COAST. WEAK WARM ADVECTION DEVELOPS WED NIGHT AS SURFACE RIDGE
AXIS SHIFTS OFFSHORE. SOME MOISTURE RETURN ALONG WITH LIGHT BOUNDARY
LAYER FLOW MAY ALLOW DEVELOPMENT OF FOG LATE IN THE PERIOD. LIGHT
RETURN FLOW AND POTENTIAL FOG WILL KEEP LOWS A LITTLE ABOVE CLIMO.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...WEAK HIGH PRESSURE WILL REMAIN OVER THE AREA
EARLY THURS AS RIDGE HOLDS ON ALOFT...BUT BY LATE THURS INTO
FRIDAY A COLD FRONT WILL MOVE INTO THE CAROLINAS. SHOULD REMAIN
DRY FOR THURS AT LEAST OVER MOST OF AREA BUT BY THURS NIGHT INTO
FRI...EXPECT INCREASED SHOWER AND THUNDERSTORM ACTIVITY AS FRONT
MOVES THROUGH THE CAROLINAS. PCP WATER VALUES AS LOW AS 1.4 INCHES
THURS MORNING WILL RAMP UP GREATER THAN 2 INCHES JUST AHEAD AND
ALONG COLD FRONT AS IT MOVES SOUTH THROUGH FRI. LOOKS LIKE FRONT
WILL GET HUNG UP OVER THE COAST THROUGH AT LEAST SATURDAY AS
SHORTWAVE LIFTS OFF TO THE NORTHEAST LEAVING A BROAD TROUGH OF LOW
PRESSURE IN THE MID TO UPPER LEVELS. THIS MAINTAINS A SW FLOW
ALOFT RUNNING PARALLEL TO THE FRONT AND MAY KEEP FRONT HUNG UP
OVER OR NEARBY AREA THROUGH MUCH OF THE WEEKEND. A MORE VIGOROUS
SHORTWAVE MAY REACH FAR ENOUGH SOUTH TO GIVE FRONT A PUSH OFF
SHORE BY THE LATTER HALF OF THE WEEKEND. OVERALL EXPECT CLOUDS AND
PCP IN FORECAST FOR MUCH OF FRI AND SATURDAY WITH SOME CLEARING BY
LATE SUNDAY INTO MONDAY AS HIGH PRESSURE BUILDS DOWN FROM THE
NORTH. NOT A HIGH CONFIDENCE FORECAST IN TERMS OF HOW FAR SOUTH
THE FRONT WILL INITIALLY MAKE IT BEFORE STALLING. TOUGH WIND
FORECAST WITH SOUTHERLY WINDS AHEAD OF FRONT THURS INTO FRI BUT
MAY SEE WINDS BECOME VARIABLE OR NORTH AS FRONT REACHES INTO AREA
OVER THE WEEKEND.
EXPECT TEMPS UP AROUND 90 OR SO ON THURS...BUT BY FRI INTO SATURDAY
CLOUDS AND SHWRS WILL AFFECT THE TEMPS AND THEN SOME COOLER AIR WILL
BEGIN TO MOVE IN BEHIND FRONT LATER ON SATURDAY INTO
SUNDAY...KEEPING TEMPS IN THE LOWER 80S OVER THE WEEKEND INTO EARLY
NEXT WEEK. WILL SEE SOME READINGS IN THE 70S FOR HIGHS INLAND WITH
COMBINATION OF COOLER AIR MOVING IN FROM THE N-NW AND CLOUDS AND PCP
OVER THE AREA LATE OVER THE WEEKEND.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...AT KFLO/KLBT IFR/TEMPO LIFR WILL CONTINUE AT LEAST INTO
THE EARLY EVENING HOURS. GRADUAL IMPROVEMENT IN VSBYS EXPECTED THIS
AFTERNOON AS RA ENDS FROM W-E AND WINDS BECOME N. AT THE COASTAL
TERMINALS VFR/TEMPO MVFR EXPECTED WITH PREDOMINATE SHRA. ISOLATED
TSRA POSSIBLE BUT WILL NOT INCLUDE IN TAFS ATTM. DUE TO QUICK
MOVEMENT OF ISOLATED HEAVIER SHRA BRIEF PERIODS OF IFR POSSIBLE AT
COASTAL TERMINALS. AT THE COASTAL TERMINALS WINDS WILL BE S-SW AND
GUSTY...EXCEPT LIGHT SE AT KILM.
PRECIPITATION ENDS COASTAL TERMINALS THIS EVENING. IFR WILL IMPROVE
TO MVFR KFLO/KLBT OVERNIGHT AS WEAK HIGH PRESSURE/SUBSIDENCE BUILDS
IN. SOME IFR POSSIBLE COASTAL TERMINALS OVERNIGHT. SUB-VFR
CONDITIONS IMPROVE TO VFR MID MORNING AT KFLO/KLBT AND COASTAL
TERMINALS LATE IN THE TAF VALID PERIOD AS WINDS BECOME WESTERLY.
EXTENDED OUTLOOK...CHANCE OF SHOWERS EARLY TUESDAY. OTHERWISE VFR
WILL DEVELOP TUESDAY AND PERSIST THROUGH THURSDAY. SHOWERS/TSTMS
RETURN ON FRIDAY AS ANOTHER COLD FRONT APPROACHES THE TERMINALS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM MONDAY...LOW PRESSURE IS MOVING NORTHEAST ALONG A
NEARLY STATIONARY FRONT NEAR INTERSTATE 95 AND SHOULD PUSH INTO
NORTHEASTERN NORTH CAROLINA LATE TONIGHT. THIS WILL DRAG THE FRONT
DOWN TOWARD THE COAST WITH WINDS VEERING MORE WESTERLY LATE ALONG
THE SOUTH CAROLINA COAST. ALTHOUGH RAINFALL INTENSITY HAS REALLY
DIMINISHED THIS AFTERNOON...ADDITIONAL WAVES OF SHOWERS AND
THUNDERSTORMS WILL PROBABLY DEVELOP LATER THIS EVENING AND AFFECT
THE AREA OVERNIGHT...MOST NUMEROUS IN THE CAPE FEAR WATERS TOWARD
AND AFTER MIDNIGHT.
SOUTH WINDS AHEAD OF THE INLAND LOW INCREASED TO AROUND 20 KNOTS
ALONG THE SOUTH CAROLINA COAST EARLIER TODAY WITH 25 KNOT GUSTS.
WIND SPEEDS ALONG THE SOUTH CAROLINA COAST HAVE PEAKED AND SHOULD
DIMINISH GRADUALLY THROUGH THE NIGHT. ALONG THE NC COAST THE
STRONGEST SOUTH WINDS WILL BEGIN TO RAMP UP SHORTLY BUT WILL
PROBABLY ONLY EXCEED 15 KNOTS FOR A FEW HOURS AROUND MIDNIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...EXITING LOW PRESSURE WILL SLOWLY PUSH THE
STALLED FRONT OFF THE COAST DURING TUE. SOUTHWEST FLOW AT THE START
OF THE PERIOD WILL GRADUALLY VEER TO WEST-NORTHWEST LATER TUE AND
TUE NIGHT. GRADIENT REMAINS WEAK AND THE LACK OF ANY COLD PUSH WILL
KEEP WIND SPEEDS 10 KT OR LESS BOTH PRE AND POST FRONT. ELONGATED
SURFACE HIGH BUILDS IN FROM THE WEST WED WITH WINDS VEERING TO
NORTHERLY DURING THE DAY. LATE IN THE DAY SURFACE RIDGE AXIS MOVES
OVERHEAD WITH NORTHERLY FLOW UNDER 10 KT BECOMING LIGHT AND HIGHLY
VARIABLE. WEAK RETURN FLOW DEVELOPS LATE IN THE PERIOD AS THE
SURFACE HIGH SHIFTS EAST OF THE WATERS. SEAS 3 TO 4 FT WILL CARRY
OVER FROM THE PREVIOUS FORECAST PERIOD BUT WILL QUICKLY DROP TO 2 TO
3 FT TUE DUE TO THE COMBINATION OF LIGHT WINDS AND OFFSHORE FLOW.
FURTHER REDUCTION IN SEAS IS ANTICIPATED ON WED.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM MONDAY...SOUTHERLY WINDS WILL INCREASE THROUGH THURS
BETWEEN BERMUDA HIGH AND COLD FRONT MAKING ITS WAY INTO THE
CAROLINAS....BUT OVERALL EXPECT WINDS TO REMAIN BELOW 15 KTS. MUCH
UNCERTAINTY EXISTS AS TO HOW FAR THE FRONT WILL REACH BEFORE
STALLING AND THEREFORE WILL MAINTAIN SOUTHERLY WINDS THROUGH EARLY
SATURDAY. BY LATE SATURDAY INTO SUNDAY WINDS SHOULD COME AROUND TO
THE NE TO N AS FRONT GETS A PUSH SOUTHWARD. WILL SHOW A NORTHERLY
SURGE UP TO 15 KTS BY SUN MORNING BUT THIS IS ALL DEPENDENT ON HOW
FAR SOUTH THE COLD FRONT MAKES IT AND HOW MUCH COLD AIR BLEEDS SOUTH
INTO THE WATERS. SEAS OF 2 TO 3 FT MAY INCREASE UP TO 3 TO 4 FT IN
INCREASED SOUTHERLY FLOW BY SATURDAY AND MAY SEE A BIT MORE OF AN
INCREASE BY SUNDAY IN COOLER NORTHERLY FLOW BEHIND FRONT.
&&
.TIDES/COASTAL FLOODING...
AS OF 3 PM MONDAY...A LARGE POSITIVE TIDAL ANOMALY ON THE LOWER CAPE
FEAR RIVER AROUND +0.75 FEET SHOULD ALLOW THE RIVER TO FLOOD AT HIGH
TIDE THIS EVENING AND AGAIN TUESDAY MORNING. THE REASONS FOR THIS
ARE ASTRONOMICAL (FULL MOON)...METEOROLOGICAL (RECENT HEAVY RAIN AND
STEADY SOUTH WINDS)...AND NON-METEOROLOGICAL (DEEP DREDGING IN THE
RIVER CHANNEL.) THE COASTAL FLOOD ADVISORY FOR THE LOWER CAPE FEAR
RIVER WILL EXTEND ACROSS THE NEXT TWO HIGH TIDES...10 PM THIS
EVENING AND 1030 AM TUESDAY MORNING.
THE TIDAL ANOMALY MEASURED AT THE MYRTLE BEACH AND WRIGHTSVILLE
BEACH GAUGES APPEARS TO BE DECREASING AS WINDS VEER MORE
SOUTH-SOUTHWESTERLY AND WIND STRESS FORCING (EKMAN SPIRAL) PUSHES
LESS WATER UP AGAINST THE SHORELINE. ASSUMING TIDAL ANOMALIES REMAIN
+0.3 FEET OR LESS WE SHOULD REMAIN BELOW COASTAL FLOODING CRITERIA.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR SCZ024.
NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ087.
FLOOD WATCH THROUGH TUESDAY MORNING FOR NCZ096-099-105>110.
COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO NOON EDT
TUESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...RGZ
AVIATION...MRR
TIDES/COASTAL FLOODING...TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1246 PM EDT MON SEP 8 2014
.SYNOPSIS...
WET WEATHER IS EXPECTED TODAY AS LOW PRESSURE DRAGS TROPICAL
MOISTURE UP ALONG A FRONT THAT HAS STALLED OVER THE EASTERN
CAROLINAS. DRIER AIR BUILDING IN TUESDAY WILL ALLOW FOR A WARMING
TREND WEDNESDAY AND THURSDAY. A FAIRLY ROBUST COLD FRONT MAY ARRIVE
FRIDAY NIGHT OR SATURDAY. THE COLD FRONT WILL MOVE OFF THE COAST
SATURDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE NORTH FOR
SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM MONDAY...RECENT MESOANALYSIS SHOWED 1016 MB LOW
PRESSURE JUST SOUTHWEST OF FLORENCE. THE LOW IS FIRMLY ATTACHED TO
THE FRONT AND SHOULD SLOWLY MOVE NORTHEASTWARD ALONG THE BOUNDARY
THROUGH THE AFTERNOON AND EVENING HOURS. PRECIPITATION IS DRYING UP
BEHIND THE LOW AND THE LAST SEVERAL HRRR RUNS SHOW THIS MAY ACTUALLY
BE THE BACK EDGE OF THE EVENT. I HAVE UPDATED POP GRIDS THROUGH
TONIGHT TO LOWER POPS ACROSS MUCH OF INTERIOR SOUTH CAROLINA PLUS
ROBESON COUNTY NC OVERNIGHT. ALONG THE COAST THE MOISTURE CONVEYOR
CONTINUES AND SHOULD RESULT IN MULTIPLE WAVES OF SHOWERS AND
THUNDERSTORMS CONTINUING. PREVIOUS DISCUSSION FROM 1000 AM FOLLOWS...
AFTER COLLABORATION WITH SURROUNDING NWS OFFICES AND THE NESDIS
SATELLITE PRECIPITATION BRANCH WE HAVE ISSUED A FLOOD WATCH FOR ALL
OF SOUTHEASTERN NORTH CAROLINA PLUS MARLBORO...DARLINGTON AND DILLON
COUNTIES IN SOUTH CAROLINA. THIS DELINEATION WAS CHOSEN BASED ON
GAUGE-MEASURED AND RADAR-OBSERVED RAINFALL OVER THE PAST 24 HOURS
PLUS FORECAST RAINFALL AMOUNTS OF 1-2 INCHES WITH ISOLATED 4-5 INCH
AMOUNTS IN THE NEXT 12-24 HOURS.
THE REGIONS AT HIGHEST RISK FOR FLOODING ARE JUST NORTH OF FLORENCE
FOR THE NEXT 4-8 HOURS AS SLOW-MOVING SHOWERS PIVOT AROUND THE
NORTH SIDE OF THE LOW...AND THEN TONIGHT ACROSS COASTAL NEW
HANOVER AND PENDER COUNTIES AS HEAVY RAIN SHOULD PUSH ONSHORE
AHEAD OF THE APPROACHING LOW. THESE ARE ALSO THE TWO REGIONS THAT
ALREADY HAVE PICKED UP 3-4 INCHES OF RAIN AND REALISTICALLY COULD
NOT HANDLE MORE THAN ANOTHER 1.0 TO 1.5 INCHES OF RAIN IN AN HOUR
WITHOUT CAUSING FLOODING.
A STALLED FRONT LOCATED ROUGHLY FROM CLINTON TO FAYETTEVILLE...
LAURINBURG...DARLINGTON AND SUMTER HAS ACTUALLY BACKED UP TO THE
NORTH A LITTLE EARLY THIS MORNING. THIS IS PROBABLY DUE TO
SOUTHERLY WINDS EAST OF SURFACE LOW BETWEEN SUMTER AND ORANGEBURG.
THIS LOW SHOULD SLOWLY ADVANCE ITS WAY NORTHEASTWARD TODAY AND
TONIGHT. BROAD LOW-LEVEL CONVERGENCE NEAR THIS LOW COUPLED WITH
MORE FOCUSED CONVERGENCE ALONG THE FRONT...PLUS FRICTIONAL
CONVERGENCE OF ONSHORE WINDS ALONG THE COAST SHOULD KEEP PLENTY OF
SHOWERS AND THUNDERSTORMS FIRING THROUGHOUT THE DAY. IN THE UPPER
LEVELS A SERIES OF WEAK UPPER DISTURBANCES MOVING ACROSS THE
CENTRAL APPALACHIANS AND VIRGINIA WILL HELP ACCELERATE THE JET
STREAM FLOW ACROSS THE COASTAL MID-ATLANTIC STATES...PLACING THE
EASTERN CAROLINAS WITHIN THE FAVORABLE RIGHT-ENTRANCE REGION OF
THIS JET MAX. THE SUBSEQUENT UPPER DIVERGENCE WILL HELP ENHANCE
OUR OVERALL SYNOPTIC LIFT ACROSS THE AREA.
THE AIRMASS IS ALREADY CONDITIONALLY UNSTABLE WITH ELEVATED CAPE
RANGING FROM 500 J/KG INLAND TO NEARLY 2000 J/KG ON THE COAST.
THERE WON`T BE A LOT OF DAYTIME HEATING TODAY GIVEN THICK CLOUDS
AND PRECIP...BUT ASSUMING WE CAN PUSH SURFACE TEMPS TO 80 THIS
INSTABILITY WILL BECOME SURFACE-BASED. HIGHS SHOULD RANGE FROM THE
UPPER 70S WEST OF I-95...TO 80-83 ELSEWHERE. IF A LITTLE SUN COULD
PEEK THROUGH ACROSS COASTAL SOUTH CAROLINA SOME MID 80S COULD BE
REALIZED BEFORE SHOWERS DEVELOP AND KNOCK TEMPS BACK DOWN.
PRECIPITATION SHOULD GRADUALLY END OVERNIGHT BEHIND THE SURFACE
LOW AS IT CRAWLS NORTHEASTWARD ALONG THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...FRONTAL LOW WILL BE CROSSING THE REGION ON
TUESDAY. THERE IS STILL SOME MINOR TIMING DIFFERENCES BU THE
SLIGHTLY QUICKER WRF SEEMS TO FIT BEST WITH PREVIOUS THINKING. AFTER
WHAT SHOULD STILL BE A RATHER WET START RAIN CHANCES AND MOREOVER
RAINFALL AMOUNTS WILL BE ON THE WANE BY AFTERNOON AS MID LEVEL
DRYING IN ZONAL FLOW INCREASINGLY OFFSETS THE LINGERING LL FRONTAL
MOISTURE. AS THIS DRYING TREND CONTINUES DOWN INTO THE LOWER LEVELS
TUESDAY NIGHT INTO WEDNESDAY TI WILL NOT ONLY LEAD TO A FURTHER
DECREASE IN RAIN CHANCES (TO NEAR ZERO) BUT ALSO TAKE ON THE FORM OF
DECREASING CLOUD COVER. TEMPS TUESDAY WILL HAVE A COASTAL VS INLAND
RANGE AS THE LATTER MAY SEE SOME BREAKS OF SUN THAT ADD A FEW
DEGREES OF WARMTH. ON WEDNESDAY A WEAK SFC GRADIENT PAIRED WITH SOME
SUBTLE HEIGHT RISES ALOFT SHOULD YIELD SEASONABLE TO SLIGHTLY WARM
TEMPERATURES.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...WARM WEATHER EXPECTED THURSDAY AND FRIDAY WITH
A GRADUAL INCREASE IN RAIN CHANCES STARTING THURSDAY NIGHT AS A COLD
FRONT APPROACHES. THE GFS HAS MADE A CONSIDERABLE SHIFT TOWARDS
QUICKER TIMING WITH THIS BOUNDARY THAT COULD IMPLY THAT FRIDAY IS IN
FACT NOT THAT MILD ANYMORE. POSSIBLE...BUT TOO NEW AN IDEA TO LATCH
ONTO AT THIS POINT. INTERESTINGLY THE 00Z ECMWF IS SLOWER THAN NOT
ONLY PREV MODEL BUT PREV THINKING. BEST GUESS IS THAT HIGHEST POPS
SHOULD COME FRIDAY NIGHT. TEMPERATURES WILL ALSO BE HIGHLY MODULATED
BY THE TIMING OF FROPA AS IT MAY BE PACKING SOME CONSIDERABLY COOLER
AIR.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...AT KFLO/KLBT IFR/TEMPO LIFR WILL CONTINUE AT LEAST INTO
THE EARLY EVENING HOURS. GRADUAL IMPROVEMENT IN VSBYS EXPECTED THIS
AFTERNOON AS RA ENDS FROM W-E AND WINDS BECOME N. AT THE COASTAL
TERMINALS VFR/TEMPO MVFR EXPECTED WITH PREDOMINATE SHRA. ISOLATED
TSRA POSSIBLE BUT WILL NOT INCLUDE IN TAFS ATTM. DUE TO QUICK
MOVEMENT OF ISOLATED HEAVIER SHRA BRIEF PERIODS OF IFR POSSIBLE AT
COASTAL TERMINALS. AT THE COASTAL TERMINALS WINDS WILL BE S-SW AND
GUSTY...EXCEPT LIGHT SE AT KILM.
PRECIPITATION ENDS COASTAL TERMINALS THIS EVENING. IFR WILL IMPROVE
TO MVFR KFLO/KLBT OVERNIGHT AS WEAK HIGH PRESSURE/SUBSIDENCE BUILDS
IN. SOME IFR POSSIBLE COASTAL TERMINALS OVERNIGHT. SUB-VFR
CONDITIONS IMPROVE TO VFR MID MORNING AT KFLO/KLBT AND COASTAL
TERMINALS LATE IN THE TAF VALID PERIOD AS WINDS BECOME WESTERLY.
EXTENDED OUTLOOK...CHANCE OF SHOWERS EARLY TUESDAY. OTHERWISE VFR
WILL DEVELOP TUESDAY AND PERSIST THROUGH THURSDAY. SHOWERS/TSTMS
RETURN ON FRIDAY AS ANOTHER COLD FRONT APPROACHES THE TERMINALS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM MONDAY...QUITE A BELT OF STRONG SOUTHERLY WINDS HAS
DEVELOPED ALONG THE SOUTH CAROLINA COAST IN THE PAST FEW HOURS.
MESOANALYSIS SHOWS THIS IS A TIGHTENING OF THE PRESSURE GRADIENT OUT
AHEAD OF THE LOW WHICH IS NOW CENTERED JUST SOUTHWEST OF FLORENCE
SC. SOUTH WINDS 15-20 KNOTS WITH 25 KNOT GUSTS SHOULD CONTINUE
THROUGH THE AFTERNOON...SPREADING NORTHWARD WITH TIME TO INCLUDE THE
BRUNSWICK COUNTY COASTLINE AS FAR EAST AS CAPE FEAR...THEN SPREADING
NORTH AND EAST OF CAPE FEAR THIS EVENING. FORTUNATELY INLAND AIR
TEMPERATURES ARE NO WARMER THAN OFFSHORE SO THERE IS NO SEABREEZE
COMPONENT TO ADD TO WIND SPEEDS. WAVES OF SHOWERS AND THUNDERSTORMS
WILL CONTINUE TO WHIP NORTHWARD ACROSS THE AREA INTO THE EVENING.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...THE START OF THE PERIOD WILL BE THE MOST
ACTIVE AS LOW PRESSURE MOVES UP FRONTAL BOUNDARY JUST INLAND FROM
THE COAST. THIS WILL TIGHTEN THE GRADIENT TO THE POINT WHERE WINDS
SHOULD BE IN THE 15 TO 20 KT RANGE MOST AREAS...ALTHOUGH WIND
SPEEDS MAY ALREADY BE FALLING OVER SOUTHERN ZONES. SOME 5 FT SEAS
MAY BE AFFECTING WATERS ALONG FRYING PAN SHOALS BUT ENOUGH OF A
NEARSHORE/OFFSHORE GRADIENT EXPECTED TO PRECLUDE CAUTIONARY
HEADLINES. THE EXIT OF THE WAVE WILL LEAD TO FAIRLY RAPID DECREASE
IN WINDS AND SEAS LATE TUESDAY INTO TUESDAY NIGHT FROM SOUTH TO
NORTH. AS WIND SPEEDS DECREASE THERE WILL ALSO BE VEERING IN
DIRECTION AND THE EXITING WAVE PUSHES THE FRONT OFFSHORE. A LIGHT
NORTHERLY WIND IS THUS EXPECTED ON WEDNESDAY AT LEAST TO START THE
DAY. A TURN TO A MORE ONSHORE DIRECTION WILL AT FIRST BE LOCALIZED
AS THE SEA BREEZE KICKS IN BUT THEN SHOULD OCCUR GENTLY AREA-WIDE
AS THE SYNOPTIC SCALE FLOW TURNS TO WEAKLY SOUTHERLY.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...JUST A GENTLE SW FLOW DEVELOPING ON THURSDAY
AS THE NORMAL WEST ATLANTIC HIGH PRESSURE HAS TROUBLE GETTING
ESTABLISHED INTO THE SOUTHEAST AND MID ATLANTIC BY SOME LINGER
TROUGHINESS. THIS FLOW REGIME WILL STRENGTHEN ON FRIDAY AS A FAIRLY
STRONG COLD FRONT APPROACHES. MODELS HAVE DIVERGED OVERNIGHT WITH
THE TIMING OF THIS FRONT SO THE DEGREE OF STRENGTHENING HAS COME
INTO QUESTION.
&&
.TIDES/COASTAL FLOODING...
AS OF 600 AM MONDAY...THE LOWER CAPE FEAR RIVER IS EXPECTED TO
EXCEED MINOR COASTAL FLOOD THRESHOLDS DURING HIGH TIDE THIS
MORNING AND A COASTAL FLOOD ADVISORY HAS BEEN ISSUED. THE EVENING
HIGH TIDE WILL BE THE HIGHER OF THE TWO HIGH TIDES AND WE EXPECT
WATER LEVELS WILL BE EVEN HIGHER LATE THIS EVENING. HIGH TIDE IN
DOWNTOWN WILMINGTON IS AT 930 AM AND 10 PM.
THE RISK FOR MINOR COASTAL FLOODING ALONG PORTIONS OF THE LOWER
CAPE FEAR RIVER DURING HIGH TIDE WILL CONTINUE FOR MUCH OF THE
WEEK. THE FULL MOON IS TODAY. THE LATE NIGHT TIDE WILL BE HIGHEST.
THE FULL MOON MAY EXACERBATE ANY FLOOD ISSUES ALONG THE COAST
THIS MORNING AND AGAIN THIS EVE. HIGH TIDE AT THE BEACHES IS
AROUND 7 AM AND 730 PM. HOWEVER...WE DO NOT EXPECT MINOR COASTAL
FLOOD THRESHOLDS TO BE REACHED AT THE BEACHES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087.
FLOOD WATCH THROUGH TUESDAY MORNING FOR NCZ096-099-105>110.
COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
604 AM EDT MON SEP 8 2014
.SYNOPSIS...
WET WEATHER IS EXPECTED TODAY AS LOW PRESSURE DRAGS TROPICAL
MOISTURE UP ALONG A FRONT THAT HAS STALLED OVER THE EASTERN
CAROLINAS. DRIER AIR BUILDING IN TUESDAY WILL ALLOW FOR A WARMING
TREND WEDNESDAY AND THURSDAY. A FAIRLY ROBUST COLD FRONT MAY ARRIVE
FRIDAY NIGHT OR SATURDAY. THE COLD FRONT WILL MOVE OFF THE COAST
SATURDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE NORTH FOR
SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM MONDAY...MAIN CONCERN AGAIN IS THE POTENTIAL FOR
EXCESSIVE RAINFALL THROUGH TONIGHT. WEAK LOW PRESSURE WILL SLOWLY
MOVE UP ALONG A STALLED FRONT ACROSS THE EASTERN CAROLINAS.
ALTHOUGH TIMING DIFFERENCES REMAIN...LOW PRESSURE SHOULD BE MOVING
NORTH OF THE FORECAST AREA TUE MORNING. A FRONT LIES FROM ABOUT
ILM TO HYW TO CKI THIS MORNING AND IS EXPECTED TO MOVE LITTLE AND
MAY EVEN RETROGRADE SLIGHTLY AS WEAK LOW PRESSURE MOVES UP ALONG
THE BOUNDARY. PRECIPITABLE WATER VALUES REMAIN NEAR THE 99TH
PERCENTILE AND UP TO 2.4 INCHES. TROPICAL MOISTURE WILL CONTINUE
TO STREAM NORTHWARD ALONG AND AHEAD OF THE FRONT AND WILL BE
LIFTED UP AND OVER THE FRONT WITH GOOD OVERRUNNING BACK ACROSS
EVEN OUR MOST INLAND COUNTIES. THUS...WE ARE EXPECTING AVERAGE
RAINFALL AMOUNTS ACROSS THE FORECAST AREA OF 1 TO 3 INCHES.
HOWEVER...THE POTENTIAL IS THERE FOR TWICE THESE VALUES WHERE
CONVECTION REPEATEDLY MOVES ACROSS THE SAME GENERAL AREA. FLOOD
GUIDANCE HAS COME DOWN SLIGHTLY SINCE SUNDAY OWING TO THE GOOD
RAINFALL AMOUNTS WHICH FELL ACROSS MOST OF THE AREA. THE HEAVIEST
RAINFALL SHOULD OCCUR TODAY INTO THIS EVE...BUT MAY LINGER FOR
MUCH OF THE NIGHT ALONG THE COAST... ESPECIALLY THE CAPE FEAR
AREA. WILL SHOW POPS DIMINISHING IN THE WAKE OF LOW PRESSURE.
THE FLOOD THREAT WHILE REAL...LOOKS TO STILL BE RATHER LOCALIZED AND
THE CONSENSUS AMONG ALL NEARBY NWS OFFICES AND THE NATIONAL CENTER
IS TO FORGO A FLOOD WATCH AT THIS TIME. HOWEVER...WE DO EXPECT
SEVERAL FLOOD ADVISORIES WILL BE ISSUED THROUGH TONIGHT WITH THE
FLOOD RISK GREATEST IN URBANIZED AREAS WHERE DRAINAGE IS POOR.
THICK CLOUDS AND PRECIPITATION WILL GREATLY REDUCE THE DIURNAL RANGE
AND WE ARE ONLY EXPECTING HIGHS TO REACH THE LOWER 80S WITH SOME OF
OUR NORTHERN MOST COMMUNITIES PERHAPS FALLING JUST SHORT OF 80
DEGREES. TONIGHT...LOWS WILL BE IN THE UPPER 60S TO LOWER
70S...COOLEST ALONG AND WEST OF INTERSTATE 95.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM MONDAY...FRONTAL LOW WILL BE CROSSING THE REGION ON
TUESDAY. THERE IS STILL SOME MINOR TIMING DIFFERENCES BU THE
SLIGHTLY QUICKER WRF SEEMS TO FIT BEST WITH PREVIOUS THINKING. AFTER
WHAT SHOULD STILL BE A RATHER WET START RAIN CHANCES AND MOREOVER
RAINFALL AMOUNTS WILL BE ON THE WANE BY AFTERNOON AS MID LEVEL
DRYING IN ZONAL FLOW INCREASINGLY OFFSETS THE LINGERING LL FRONTAL
MOISTURE. AS THIS DRYING TREND CONTINUES DOWN INTO THE LOWER LEVELS
TUESDAY NIGHT INTO WEDNESDAY TI WILL NOT ONLY LEAD TO A FURTHER
DECREASE IN RAIN CHANCES (TO NEAR ZERO) BUT ALSO TAKE ON THE FORM OF
DECREASING CLOUD COVER. TEMPS TUESDAY WILL HAVE A COASTAL VS INLAND
RANGE AS THE LATTER MAY SEE SOME BREAKS OF SUN THAT ADD A FEW
DEGREES OF WARMTH. ON WEDNESDAY A WEAK SFC GRADIENT PAIRED WITH SOME
SUBTLE HEIGHT RISES ALOFT SHOULD YIELD SEASONABLE TO SLIGHTLY WARM
TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...WARM WEATHER EXPECTED THURSDAY AND FRIDAY WITH
A GRADUAL INCREASE IN RAIN CHANCES STARTING THURSDAY NIGHT AS A COLD
FRONT APPROACHES. THE GFS HAS MADE A CONSIDERABLE SHIFT TOWARDS
QUICKER TIMING WITH THIS BOUNDARY THAT COULD IMPLY THAT FRIDAY IS IN
FACT NOT THAT MILD ANYMORE. POSSIBLE...BUT TOO NEW AN IDEA TO LATCH
ONTO AT THIS POINT. INTERESTINGLY THE 00Z ECMWF IS SLOWER THAN NOT
ONLY PREV MODEL BUT PREV THINKING. BEST GUESS IS THAT HIGHEST POPS
SHOULD COME FRIDAY NIGHT. TEMPERATURES WILL ALSO BE HIGHLY MODULATED
BY THE TIMING OF FROPA AS IT MAY BE PACKING SOME CONSIDERABLY COOLER
AIR.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...UNSETTLED WEATHER WILL PERSIST THROUGH THE PERIOD AS
A SURFACE LOW SLOWLY MOVES UP THE COAST AND MERGES WITH A STALLING
COLD FRONT OVER THE EASTERN CAROLINAS. THE LATEST HRRR RUNS DEPICT
SHRA/TSRA INCREASING IN COVERAGE THIS MORNING. THE HEAVIEST
ACTIVITY IS EXPECTED ALONG THE COAST...WHERE DOWNPOURS COULD
BRIEFLY REDUCE VSBYS TO MVFR/IFR LEVELS. POST-FRONTAL IFR CIGS ARE
ALREADY SPREADING OVER OUR INLAND ZONES...SO THE STRATUS AT
KLBT/KFLO WILL LIKELY PERSIST THROUGH THE MORNING HOURS. EXPECT
MAINLY MVFR CIGS AT THE COASTAL TERMS...THOUGH PERSISTENT RAINFALL
COULD LOWER CIGS BELOW 1KFT AT TIMES.
EXPECT MORE WIDESPREAD SHOWERS/ISO TSTMS DURING THE DAY AS THE LOW
MOVES UP THE COAST. MVFR CONDITIONS ARE EXPECTED TO PREVAIL DURING
THE AFTN WITH BRIEF AND LOCALIZED AREAS OF IFR. THERE IS STILL SOME
UNCERTAINTY REGARDING THE SPEED AND TRACK OF THE LOW...WHICH MAKES
FOR A LOWER CONFIDENCE WIND FORECAST. IT LOOKS LIKE THE COAST WILL
SEE SOUTHEAST WINDS 10 KT WITH HIGHER GUSTS POSSIBLE IF THE LOW
DEEPENS. MEANWHILE THE INLAND TERMS WILL KEEP NORTHEAST WINDS AOB 10
KT FOR MUCH OF THE DAY. PCPN WILL TAPER OFF FROM SW TO NE AS THE LOW
CONTINUES MOVING NORTHWARD...WITH WINDS SHIFTING TO THE NORTH ON THE
BACKSIDE OF THE LOW NEAR THE END OF THE PERIOD.
EXTENDED OUTLOOK...CHANCE OF SHOWERS EARLY TUESDAY. OTHERWISE VFR
WILL PREVAIL THROUGH THURSDAY. SHOWERS/TSTMS RETURN ON FRIDAY AS
ANOTHER COLD FRONT APPROACHES OUR CWA.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM MONDAY...A SMALL CRAFT SHOULD EXERCISE CAUTION HAS
BEEN ISSUED FOR TODAY FOR ALL WATERS EXCEPT THOSE NORTH OF THE
MOUTH OF THE CAPE FEAR RIVER. WE DO EXPECT THAT HIGHER WINDS AND
SEAS WILL SPREAD INTO THE NORTHERNMOST WATERS TONIGHT. MARINERS
SHOULD EXPECT WIDESPREAD HEAVY RAIN AND POOR VISIBILITIES ACROSS
THE WATERS IN TROPICAL DOWNPOURS INTO TONIGHT.
LOW PRESSURE WILL MOVE UP ALONG A STALLED FRONT JUST WEST OF THE
WATERS. THIS WILL TIGHTEN THE PRESSURE GRADIENT...RESULTING IN
BUILDING SEAS AND INCREASING WINDS. WINDS ARE EXPECTED TO PEAK
AROUND 20 KT WITH WIND SPEEDS INCREASING ACROSS THE SOUTHERN WATERS
THIS MORNING AND THE NORTHERN WATERS THIS AFTERNOON AND TONIGHT.
GUSTS TO AROUND 25 KT WILL BE POSSIBLE. THE DIRECTION SHOULD HOLD
SOUTH TODAY...AND THEN VEER AS LOW PRESSURE MOVES NORTH OF OUR
LATITUDE. SW TO W WINDS SHOULD GRADUALLY DEVELOP ACROSS THE WATERS
OVERNIGHT AND TUE MORNING. AS THE DIRECTION VEERS...WIND SPEEDS WILL
DIMINISH.
IN RESPONSE TO THE INCREASING WINDS...SEAS WILL BUILD TO 4 TO 5 FT.
IT IS POSSIBLE FOR A BRIEF PERIOD OF 6 FT SEAS. SEAS WILL BE HIGHEST
ACROSS THE SOUTHERN WATERS TODAY AND THE NORTHERN WATERS TONIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...THE START OF THE PERIOD WILL BE THE MOST
ACTIVE AS LOW PRESSURE MOVES UP FRONTAL BOUNDARY JUST INLAND FROM
THE COAST. THIS WILL TIGHTEN THE GRADIENT TO THE POINT WHERE WINDS
SHOULD BE IN THE 15 TO 20 KT RANGE MOST AREAS...ALTHOUGH WIND SPEEDS
MAY ALREADY BE FALLING OVER SOUTHERN ZONES. SOME 5 FT SEAS MAY BE
AFFECTING WATERS ALONG FRYING PAN SHOALS BUT ENOUGH OF A
NEARSHORE/OFFSHORE GRADIENT EXPECTED TO PRECLUDE CAUTIONARY
HEADLINES. THE EXIT OF THE WAVE WILL LEAD TO FAIRLY RAPID DECREASE
IN WINDS AND SEAS LATE TUESDAY INTO TUESDAY NIGHT FROM SOUTH TO
NORTH. AS WIND SPEEDS DECREASE THERE WILL ALSO BE VEERING IN
DIRECTION AND THE EXITING WAVE PUSHES THE FRONT OFFSHORE. A LIGHT
NORTHERLY WIND IS THUS EXPECTED ON WEDNESDAY AT LEAST TO START THE
DAY. A TURN TO A MORE ONSHORE DIRECTION WILL AT FIRST BE LOCALIZED
AS THE SEA BREEZE KICKS IN BUT THEN SHOULD OCCUR GENTLY AREA-WIDE AS
THE SYNOPTIC SCALE FLOW TURNS TO WEAKLY SOUTHERLY.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...JUST A GENTLE SW FLOW DEVELOPING ON THURSDAY
AS THE NORMAL WEST ATLANTIC HIGH PRESSURE HAS TROUBLE GETTING
ESTABLISHED INTO THE SOUTHEAST AND MID ATLANTIC BY SOME LINGER
TROUGINESS. THIS FLOW REGIME WILL STRENGTHEN ON FRIDAY AS A FAIRLY
STRONG COLD FRONT APPROACHES. MODELS HAVE DIVERGED OVERNIGHT WITH
THE TIMING OF THIS FRONT SO THE DEGREE OF STRENGTHENING HAS COME
INTO QUESTION.
&&
.TIDES/COASTAL FLOODING...
AS OF 600 AM MONDAY...THE LOWER CAPE FEAR RIVER IS EXPECTED TO
EXCEED MINOR COASTAL FLOOD THRESHOLDS DURING HIGH TIDE THIS
MORNING AND A COASTAL FLOOD ADVISORY HAS BEEN ISSUED. THE EVENING
HIGH TIDE WILL BE THE HIGHER OF THE TWO HIGH TIDES AND WE EXPECT
WATER LEVELS WILL BE EVEN HIGHER LATE THIS EVENING. HIGH TIDE IN
DOWNTOWN WILMINGTON IS AT 930 AM AND 10 PM.
THE RISK FOR MINOR COASTAL FLOODING ALONG PORTIONS OF THE LOWER
CAPE FEAR RIVER DURING HIGH TIDE WILL CONTINUE FOR MUCH OF THE
WEEK. THE FULL MOON IS TODAY. THE LATE NIGHT TIDE WILL BE HIGHEST.
THE FULL MOON MAY EXACERBATE ANY FLOOD ISSUES ALONG THE COAST
THIS MORNING AND AGAIN THIS EVE. HIGH TIDE AT THE BEACHES IS
AROUND 7 AM AND 730 PM. HOWEVER...WE DO NOT EXPECT MINOR COASTAL
FLOOD THRESHOLDS TO BE REACHED AT THE BEACHES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...RJD
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...RJD/BJR
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
341 AM EDT MON SEP 8 2014
.SYNOPSIS...
WET WEATHER IS EXPECTED TODAY AS LOW PRESSURE DRAGS TROPICAL
MOISTURE UP ALONG A FRONT THAT HAS STALLED OVER THE EASTERN
CAROLINAS. DRIER AIR BUILDING IN TUESDAY WILL ALLOW FOR A WARMING
TREND WEDNESDAY AND THURSDAY. A FAIRLY ROBUST COLD FRONT MAY ARRIVE
FRIDAY NIGHT OR SATURDAY. THE COLD FRONT WILL MOVE OFF THE COAST
SATURDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE NORTH FOR
SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM MONDAY...MAIN CONCERN AGAIN IS THE POTENTIAL FOR
EXCESSIVE RAINFALL THROUGH TONIGHT. WEAK LOW PRESSURE WILL SLOWLY
MOVE UP ALONG A STALLED FRONT ACROSS THE EASTERN CAROLINAS. ALTHOUGH
TIMING DIFFERENCES REMAIN...LOW PRESSURE SHOULD BE MOVING NORTH OF
THE FORECAST AREA TUE MORNING. A FRONT LIES FROM ABOUT ILM TO HYW TO
CKI THIS MORNING AND IS EXPECTED TO MOVE LITTLE AND MAY EVEN
RETROGRADE SLIGHTLY AS WEAK LOW PRESSURE MOVES UP ALONG THE
BOUNDARY. PRECIPITABLE WATER VALUES REMAIN NEAR THE 99TH PERCENTILE
AND UP TO 2.4 INCHES. TROPICAL MOISTURE WILL CONTINUE TO STREAM
NORTHWARD ALONG AND AHEAD OF THE FRONT AND WILL BE LIFTED UP AND
OVER THE FRONT WITH GOOD OVERRUNNING BACK ACROSS EVEN OUR MOST
INLAND COUNTIES. THUS...WE ARE EXPECTING AVERAGE RAINFALL AMOUNTS
ACROSS THE FORECAST AREA OF 1 TO 3 INCHES. HOWEVER...THE POTENTIAL
IS THERE FOR TWICE THESE VALUES WHERE CONVECTION REPEATEDLY MOVES
ACROSS THE SAME GENERAL AREA. FLOOD GUIDANCE HAS COME DOWN SLIGHTLY
SINCE SUNDAY OWING TO THE GOOD RAINFALL AMOUNTS WHICH FELL ACROSS
MOST OF THE AREA. THE HEAVIEST RAINFALL SHOULD OCCUR TODAY INTO THIS
EVE...BUT MAY LINGER FOR MUCH OF THE NIGHT ALONG THE COAST...
ESPECIALLY THE CAPE FEAR AREA. WILL SHOW POPS DIMINISHING IN THE
WAKE OF LOW PRESSURE.
THE FLOOD THREAT WHILE REAL...LOOKS TO STILL BE RATHER LOCALIZED AND
THE CONSENSUS AMONG ALL NEARBY NWS OFFICES AND THE NATIONAL CENTER
IS TO FORGO A FLOOD WATCH AT THIS TIME. HOWEVER...WE DO EXPECT
SEVERAL FLOOD ADVISORIES WILL BE ISSUED THROUGH TONIGHT WITH THE
FLOOD RISK GREATEST IN URBANIZED AREAS WHERE DRAINAGE IS POOR. THE
FULL MOON MAY EXACERBATE ANY FLOOD ISSUES ALONG THE COAST THIS
MORNING AND AGAIN THIS EVE. HIGH TIDE AT THE BEACHES IS AROUND 7
AM AND 730 PM. HOWEVER...WE DO NOT EXPECT MINOR COASTAL FLOOD
THRESHOLDS TO BE REACHED AT THE BEACHES. HOWEVER...THE LOWER CAPE
FEAR RIVER WILL BE MORE PROBLEMATIC. ALTHOUGH WE SHOULD STAY JUST
BELOW CRITERIA THIS MORNING...WE WILL LIKELY AGAIN EXCEED THRESHOLDS
THIS EVE. HIGH TIDE IN DOWNTOWN WILMINGTON IS AT 930 AM AND 10 PM.
THICK CLOUDS AND PRECIPITATION WILL GREATLY REDUCE THE DIURNAL RANGE
AND WE ARE ONLY EXPECTING HIGHS TO REACH THE LOWER 80S WITH SOME OF
OUR NORTHERN MOST COMMUNITIES PERHAPS FALLING JUST SHORT OF 80
DEGREES. TONIGHT...LOWS WILL BE IN THE UPPER 60S TO LOWER
70S...COOLEST ALONG AND WEST OF INTERSTATE 95.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...FRONTAL LOW WILL BE CROSSING THE REGION ON
TUESDAY. THERE IS STILL SOME MINOR TIMING DIFFERENCES BU THE
SLIGHTLY QUICKER WRF SEEMS TO FIT BEST WITH PREVIOUS THINKING. AFTER
WHAT SHOULD STILL BE A RATHER WET START RAIN CHANCES AND MOREOVER
RAINFALL AMOUNTS WILL BE ON THE WANE BY AFTERNOON AS MID LEVEL
DRYING IN ZONAL FLOW INCREASINGLY OFFSETS THE LINGERING LL FRONTAL
MOISTURE. AS THIS DRYING TREND CONTINUES DOWN INTO THE LOWER LEVELS
TUESDAY NIGHT INTO WEDNESDAY TI WILL NOT ONLY LEAD TO A FURTHER
DECREASE IN RAIN CHANCES (TO NEAR ZERO) BUT ALSO TAKE ON THE FORM OF
DECREASING CLOUD COVER. TEMPS TUESDAY WILL HAVE A COASTAL VS INLAND
RANGE AS THE LATTER MAY SEE SOME BREAKS OF SUN THAT ADD A FEW
DEGREES OF WARMTH. ON WEDNESDAY A WEAK SFC GRADIENT PAIRED WITH SOME
SUBTLE HEIGHT RISES ALOFT SHOULD YIELD SEASONABLE TO SLIGHTLY WARM
TEMPERATURES.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...WARM WEATHER EXPECTED THURSDAY AND FRIDAY WITH
A GRADUAL INCREASE IN RAIN CHANCES STARTING THURSDAY NIGHT AS A COLD
FRONT APPROACHES. THE GFS HAS MADE A CONSIDERABLE SHIFT TOWARDS
QUICKER TIMING WITH THIS BOUNDARY THAT COULD IMPLY THAT FRIDAY IS IN
FACT NOT THAT MILD ANYMORE. POSSIBLE...BUT TOO NEW AN IDEA TO LATCH
ONTO AT THIS POINT. INTERESTINGLY THE 00Z ECMWF IS SLOWER THAN NOT
ONLY PREV MODEL BUT PREV THINKING. BEST GUESS IS THAT HIGHEST POPS
SHOULD COME FRIDAY NIGHT. TEMPERATURES WILL ALSO BE HIGHLY MODULATED
BY THE TIMING OF FROPA AS IT MAY BE PACKING SOME CONSIDERABLY COOLER
AIR.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...UNSETTLED WEATHER WILL PERSIST THROUGH THE PERIOD AS A
SURFACE LOW SLOWLY MOVES UP THE COAST AND MERGES WITH A STALLING
COLD FRONT OVER THE EASTERN CAROLINAS. THE LATEST HRRR RUNS DEPICT
SHRA/TSRA INCREASING IN COVERAGE THIS MORNING. THE HEAVIEST ACTIVITY
IS EXPECTED ALONG THE COAST...WHERE DOWNPOURS COULD BRIEFLY REDUCE
VSBYS TO MVFR/IFR LEVELS. POST-FRONTAL IFR CIGS ARE ALREADY
SPREADING OVER OUR INLAND ZONES...SO THE STRATUS AT KLBT/KFLO WILL
LIKELY PERSIST THROUGH THE MORNING HOURS. EXPECT MAINLY MVFR CIGS AT
THE COASTAL TERMS...THOUGH PERSISTENT RAINFALL COULD LOWER CIGS
BELOW 1KFT AT TIMES.
EXPECT MORE WIDESPREAD SHOWERS/ISO TSTMS DURING THE DAY AS THE LOW
MOVES UP THE COAST. MVFR CONDITIONS ARE EXPECTED TO PREVAIL DURING
THE AFTN WITH BRIEF AND LOCALIZED AREAS OF IFR. THERE IS STILL SOME
UNCERTAINTY REGARDING THE SPEED AND TRACK OF THE LOW...WHICH MAKES
FOR A LOWER CONFIDENCE WIND FORECAST. IT LOOKS LIKE THE COAST WILL
SEE SOUTHEAST WINDS 10 KT WITH HIGHER GUSTS POSSIBLE IF THE LOW
DEEPENS. MEANWHILE THE INLAND TERMS WILL KEEP NORTHEAST WINDS AOB 10
KT FOR MUCH OF THE DAY. PCPN WILL TAPER OFF FROM SW TO NE AS THE LOW
CONTINUES MOVING NORTHWARD...WITH WINDS SHIFTING TO THE NORTH ON THE
BACKSIDE OF THE LOW NEAR THE END OF THE PERIOD.
EXTENDED OUTLOOK...CHANCE OF SHOWERS EARLY TUESDAY. OTHERWISE VFR
WILL PREVAIL THROUGH THURSDAY. SHOWERS/TSTMS RETURN ON FRIDAY AS
ANOTHER COLD FRONT APPROACHES OUR CWA.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM MONDAY...A SMALL CRAFT SHOULD EXERCISE CAUTION HAS BEEN
ISSUED FOR TODAY FOR ALL WATERS EXCEPT THOSE NORTH OF THE MOUTH OF
THE CAPE FEAR RIVER. WE DO EXPECT THAT HIGHER WINDS AND SEAS WILL
SPREAD INTO THE NORTHERNMOST WATERS TONIGHT. MARINERS SHOULD EXPECT
WIDESPREAD HEAVY RAIN AND POOR VISIBILITIES ACROSS THE WATERS IN
TROPICAL DOWNPOURS INTO TONIGHT.
LOW PRESSURE WILL MOVE UP ALONG A STALLED FRONT JUST WEST OF THE
WATERS. THIS WILL TIGHTEN THE PRESSURE GRADIENT...RESULTING IN
BUILDING SEAS AND INCREASING WINDS. WINDS ARE EXPECTED TO PEAK
AROUND 20 KT WITH WIND SPEEDS INCREASING ACROSS THE SOUTHERN WATERS
THIS MORNING AND THE NORTHERN WATERS THIS AFTERNOON AND TONIGHT.
GUSTS TO AROUND 25 KT WILL BE POSSIBLE. THE DIRECTION SHOULD HOLD
SOUTH TODAY...AND THEN VEER AS LOW PRESSURE MOVES NORTH OF OUR
LATITUDE. SW TO W WINDS SHOULD GRADUALLY DEVELOP ACROSS THE WATERS
OVERNIGHT AND TUE MORNING. AS THE DIRECTION VEERS...WIND SPEEDS WILL
DIMINISH.
IN RESPONSE TO THE INCREASING WINDS...SEAS WILL BUILD TO 4 TO 5 FT.
IT IS POSSIBLE FOR A BRIEF PERIOD OF 6 FT SEAS. SEAS WILL BE HIGHEST
ACROSS THE SOUTHERN WATERS TODAY AND THE NORTHERN WATERS TONIGHT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...THE START OF THE PERIOD WILL BE THE MOST
ACTIVE AS LOW PRESSURE MOVES UP FRONTAL BOUNDARY JUST INLAND FROM
THE COAST. THIS WILL TIGHTEN THE GRADIENT TO THE POINT WHERE WINDS
SHOULD BE IN THE 15 TO 20 KT RANGE MOST AREAS...ALTHOUGH WIND SPEEDS
MAY ALREADY BE FALLING OVER SOUTHERN ZONES. SOME 5 FT SEAS MAY BE
AFFECTING WATERS ALONG FRYING PAN SHOALS BUT ENOUGH OF A
NEARSHORE/OFFSHORE GRADIENT EXPECTED TO PRECLUDE CAUTIONARY
HEADLINES. THE EXIT OF THE WAVE WILL LEAD TO FAIRLY RAPID DECREASE
IN WINDS AND SEAS LATE TUESDAY INTO TUESDAY NIGHT FROM SOUTH TO
NORTH. AS WIND SPEEDS DECREASE THERE WILL ALSO BE VEERING IN
DIRECTION AND THE EXITING WAVE PUSHES THE FRONT OFFSHORE. A LIGHT
NORTHERLY WIND IS THUS EXPECTED ON WEDNESDAY AT LEAST TO START THE
DAY. A TURN TO A MORE ONSHORE DIRECTION WILL AT FIRST BE LOCALIZED
AS THE SEA BREEZE KICKS IN BUT THEN SHOULD OCCUR GENTLY AREA-WIDE AS
THE SYNOPTIC SCALE FLOW TURNS TO WEAKLY SOUTHERLY.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...JUST A GENTLE SW FLOW DEVELOPING ON THURSDAY
AS THE NORMAL WEST ATLANTIC HIGH PRESSURE HAS TROUBLE GETTING
ESTABLISHED INTO THE SOUTHEAST AND MID ATLANTIC BY SOME LINGER
TROUGINESS. THIS FLOW REGIME WILL STRENGTHEN ON FRIDAY AS A FAIRLY
STRONG COLD FRONT APPROACHES. MODELS HAVE DIVERGED OVERNIGHT WITH
THE TIMING OF THIS FRONT SO THE DEGREE OF STRENGTHENING HAS COME
INTO QUESTION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...BJR/RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
330 AM EDT MON SEP 8 2014
.SYNOPSIS...
WET WEATHER IS EXPECTED TODAY AS LOW PRESSURE DRAGS TROPICAL
MOISTURE UP ALONG A FRONT THAT HAS STALLED OVER THE EASTERN
CAROLINAS. DRIER AIR BUILDING IN TUESDAY WILL ALLOW FOR A WARMING
TREND WEDNESDAY AND THURSDAY. A FAIRLY ROBUST COLD FRONT MAY ARRIVE
FRIDAY NIGHT OR SATURDAY. THE COLD FRONT WILL MOVE OFF THE COAST
SATURDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE NORTH FOR
SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM MONDAY...MAIN CONCERN AGAIN IS THE POTENTIAL FOR
EXCESSIVE RAINFALL THROUGH TONIGHT. WEAK LOW PRESSURE WILL SLOWLY
MOVE UP ALONG A STALLED FRONT ACROSS THE EASTERN CAROLINAS. ALTHOUGH
TIMING DIFFERENCES REMAIN...LOW PRESSURE SHOULD BE MOVING NORTH OF
THE FORECAST AREA TUE MORNING. A FRONT LIES FROM ABOUT ILM TO HYW TO
CKI THIS MORNING AND IS EXPECTED TO MOVE LITTLE AND MAY EVEN
RETROGRADE SLIGHTLY AS WEAK LOW PRESSURE MOVES UP ALONG THE
BOUNDARY. PRECIPITABLE WATER VALUES REMAIN NEAR THE 99TH PERCENTILE
AND UP TO 2.4 INCHES. TROPICAL MOISTURE WILL CONTINUE TO STREAM
NORTHWARD ALONG AND AHEAD OF THE FRONT AND WILL BE LIFTED UP AND
OVER THE FRONT WITH GOOD OVERRUNNING BACK ACROSS EVEN OUR MOST
INLAND COUNTIES. THUS...WE ARE EXPECTING AVERAGE RAINFALL AMOUNTS
ACROSS THE FORECAST AREA OF 1 TO 3 INCHES. HOWEVER...THE POTENTIAL
IS THERE FOR TWICE THESE VALUES WHERE CONVECTION REPEATEDLY MOVES
ACROSS THE SAME GENERAL AREA. FLOOD GUIDANCE HAS COME DOWN SLIGHTLY
SINCE SUNDAY OWING TO THE GOOD RAINFALL AMOUNTS WHICH FELL ACROSS
MOST OF THE AREA. THE HEAVIEST RAINFALL SHOULD OCCUR TODAY INTO THIS
EVE...BUT MAY LINGER FOR MUCH OF THE NIGHT ALONG THE COAST...
ESPECIALLY THE CAPE FEAR AREA. WILL SHOW POPS DIMINISHING IN THE
WAKE OF LOW PRESSURE.
THE FLOOD THREAT WHILE REAL...LOOKS TO STILL BE RATHER LOCALIZED AND
THE CONSENSUS AMONG ALL NEARBY NWS OFFICES AND THE NATIONAL CENTER
IS TO FORGO A FLOOD WATCH AT THIS TIME. HOWEVER...WE DO EXPECT
SEVERAL FLOOD ADVISORIES WILL BE ISSUED THROUGH TONIGHT WITH THE
FLOOD RISK GREATEST IN URBANIZED AREAS WHERE DRAINAGE IS POOR. THE
FULL MOON MAY EXACERBATE ANY FLOOD ISSUES ALONG THE COAST THIS
MORNING AND AGAIN THIS EVE. HIGH TIDE AT THE BEACHES IS AROUND 7
AM AND 730 PM. HOWEVER...WE DO NOT EXPECT MINOR COASTAL FLOOD
THRESHOLDS TO BE REACHED AT THE BEACHES. HOWEVER...THE LOWER CAPE
FEAR RIVER WILL BE MORE PROBLEMATIC. ALTHOUGH WE SHOULD STAY JUST
BELOW CRITERIA THIS MORNING...WE WILL LIKELY AGAIN EXCEED THRESHOLDS
THIS EVE. HIGH TIDE IN DOWNTOWN WILMINGTON IS AT 930 AM AND 10 PM.
THICK CLOUDS AND PRECIPITATION WILL GREATLY REDUCE THE DIURNAL RANGE
AND WE ARE ONLY EXPECTING HIGHS TO REACH THE LOWER 80S WITH SOME OF
OUR NORTHERN MOST COMMUNITIES PERHAPS FALLING JUST SHORT OF 80
DEGREES. TONIGHT...LOWS WILL BE IN THE UPPER 60S TO LOWER
70S...COOLEST ALONG AND WEST OF INTERSTATE 95.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM MONDAY...FRONTAL LOW WILL BE CROSSING THE REGION ON
TUESDAY. THERE IS STILL SOME MINOR TIMING DIFFERENCES BU THE
SLIGHTLY QUICKER WRF SEEMS TO FIT BEST WITH PREVIOUS THINKING. AFTER
WHAT SHOULD STILL BE A RATHER WET START RAIN CHANCES AND MOREOVER
RAINFALL AMOUNTS WILL BE ON THE WANE BY AFTERNOON AS MID LEVEL
DRYING IN ZONAL FLOW INCREASINGLY OFFSETS THE LINGERING LL FRONTAL
MOISTURE. AS THIS DRYING TREND CONTINUES DOWN INTO THE LOWER LEVELS
TUESDAY NIGHT INTO WEDNESDAY TI WILL NOT ONLY LEAD TO A FURTHER
DECREASE IN RAIN CHANCES (TO NEAR ZERO) BUT ALSO TAKE ON THE FORM OF
DECREASING CLOUD COVER. TEMPS TUESDAY WILL HAVE A COASTAL VS INLAND
RANGE AS THE LATTER MAY SEE SOME BREAKS OF SUN THAT ADD A FEW
DEGREES OF WARMTH. ON WEDNESDAY A WEAK SFC GRADIENT PAIRED WITH SOME
SUBTLE HEIGHT RISES ALOFT SHOULD YIELD SEASONABLE TO SLIGHTLY WARM
TEMPERATURES.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...WARM WEATHER EXPECTED THURSDAY AND FRIDAY WITH A
GRADUAL INCREASE IN RAIN CHANCES STARTING THURSDAY NIGHT AS A COLD
FRONT APPROACHES. THE GFS HAS MADE A CONSIDERABLE SHIFT TOWARDS
QUICKER TIMING WITH THIS BOUNDARY THAT COULD IMPLY THAT FRIDAY IS IN
FACT NOT THAT MILD ANYMORE. POSSIBLE...BUT TOO NEW AN IDEA TO LATCH
ONTO AT THIS POINT. INTERESTINGLY THE 00Z ECMWF IS SLOWER THAN NOT
ONLY PREV MODEL BUT PREV THINKING. BEST GUESS IS THAT HIGHEST POPS
SHOULD COME FRIDAY NIGHT. TEMPERATURES WILL ALSO BE HIGHLY MODULATED
BY THE TIMING OF FROPA AS IT MAY BE PACKING SOME CONSIDERABLY COOLER
AIR.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...UNSETTLED WEATHER WILL PERSIST THROUGH THE PERIOD AS A
SURFACE LOW SLOWLY MOVES UP THE COAST AND MERGES WITH A STALLING
COLD FRONT OVER THE EASTERN CAROLINAS. THE LATEST HRRR RUNS DEPICT
SHRA/TSRA INCREASING IN COVERAGE THIS MORNING. THE HEAVIEST ACTIVITY
IS EXPECTED ALONG THE COAST...WHERE DOWNPOURS COULD BRIEFLY REDUCE
VSBYS TO MVFR/IFR LEVELS. POST-FRONTAL IFR CIGS ARE ALREADY
SPREADING OVER OUR INLAND ZONES...SO THE STRATUS AT KLBT/KFLO WILL
LIKELY PERSIST THROUGH THE MORNING HOURS. EXPECT MAINLY MVFR CIGS AT
THE COASTAL TERMS...THOUGH PERSISTENT RAINFALL COULD LOWER CIGS
BELOW 1KFT AT TIMES.
EXPECT MORE WIDESPREAD SHOWERS/ISO TSTMS DURING THE DAY AS THE LOW
MOVES UP THE COAST. MVFR CONDITIONS ARE EXPECTED TO PREVAIL DURING
THE AFTN WITH BRIEF AND LOCALIZED AREAS OF IFR. THERE IS STILL SOME
UNCERTAINTY REGARDING THE SPEED AND TRACK OF THE LOW...WHICH MAKES
FOR A LOWER CONFIDENCE WIND FORECAST. IT LOOKS LIKE THE COAST WILL
SEE SOUTHEAST WINDS 10 KT WITH HIGHER GUSTS POSSIBLE IF THE LOW
DEEPENS. MEANWHILE THE INLAND TERMS WILL KEEP NORTHEAST WINDS AOB 10
KT FOR MUCH OF THE DAY. PCPN WILL TAPER OFF FROM SW TO NE AS THE LOW
CONTINUES MOVING NORTHWARD...WITH WINDS SHIFTING TO THE NORTH ON THE
BACKSIDE OF THE LOW NEAR THE END OF THE PERIOD.
EXTENDED OUTLOOK...CHANCE OF SHOWERS EARLY TUESDAY. OTHERWISE VFR
WILL PREVAIL THROUGH THURSDAY. SHOWERS/TSTMS RETURN ON FRIDAY AS
ANOTHER COLD FRONT APPROACHES OUR CWA.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 PM SUNDAY...UPDATED WINDS DUE TO THE POSITIONING OF THE
FRONTAL BOUNDARY JUST INLAND FROM THE COAST. LATEST OBS AND HRRR
TRENDS INDICATE ESE-SSE DIRECTIONS ACROSS THE ILM WATERS DUE TO
THE MEANDERING OF THIS FRONT. PORTIONS OF IT MAY COME WITHIN 15
MILES OR LESS FROM THE IMMEDIATE COAST AT TIMES BUT MODELS REMAIN
ADAMANT IN KEEPING IT INLAND. SIGNIFICANT SEAS REMAIN 2 TO 4 FT
WITH WIND WAVES DOMINATING THE SEAS SPECTRUM...IE. DOMINANT
PERIODS AROUND 5 SECONDS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM MONDAY...THE START OF THE PERIOD WILL BE THE MOST ACTIVE
AS LOW PRESSURE MOVES UP FRONTAL BOUNDARY JUST INLAND FROM THE
COAST. THIS WILL TIGHTEN THE GRADIENT TO THE POINT WHERE WINDS
SHOULD BE IN THE 15 TO 20 KT RANGE MOST AREAS...ALTHOUGH WIND SPEEDS
MAY ALREADY BE FALLING OVER SOUTHERN ZONES. SOME 5 FT SEAS MAY BE
AFFECTING WATERS ALONG FRYING PAN SHOALS BUT ENOUGH OF A
NEARSHORE/OFFSHORE GRADIENT EXPECTED TO PRECLUDE CAUTIONARY
HEADLINES. THE EXIT OF THE WAVE WILL LEAD TO FAIRLY RAPID DECREASE
IN WINDS AND SEAS LATE TUESDAY INTO TUESDAY NIGHT FROM SOUTH TO
NORTH. AS WIND SPEEDS DECREASE THERE WILL ALSO BE VEERING IN
DIRECTION AND THE EXITING WAVE PUSHES THE FRONT OFFSHORE. A LIGHT
NORTHERLY WIND IS THUS EXPECTED ON WEDNESDAY AT LEAST TO START THE
DAY. A TURN TO A MORE ONSHORE DIRECTION WILL AT FIRST BE LOCALIZED
AS THE SEA BREEZE KICKS IN BUT THEN SHOULD OCCUR GENTLY AREA-WIDE AS
THE SYNOPTIC SCALE FLOW TURNS TO WEAKLY SOUTHERLY.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...JUST A GENTLE SW FLOW DEVELOPING ON THURSDAY AS
THE NORMAL WEST ATLANTIC HIGH PRESSURE HAS TROUBLE GETTING
ESTABLISHED INTO THE SOUTHEAST AND MID ATLANTIC BY SOME LINGER
TROUGINESS. THIS FLOW REGIME WILL STRENGTHEN ON FRIDAY AS A FAIRLY
STRONG COLD FRONT APPROACHES. MODELS HAVE DIVERGED OVERNIGHT WITH
THE TIMING OF THIS FRONT SO THE DEGREE OF STRENGTHENING HAS COME
INTO QUESTION.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...BJR/RJD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
138 AM EDT MON SEP 8 2014
.SYNOPSIS...
WET WEATHER IS EXPECTED THROUGH MONDAY AS LOW PRESSURE DRAGS
TROPICAL MOISTURE UP ALONG A FRONT THAT HAS STALLED OVER THE EASTERN
CAROLINAS. DRIER AIR BUILDING IN TUESDAY WILL ALLOW FOR A WARMING
TREND WEDNESDAY AND THURSDAY. A FAIRLY ROBUST COLD FRONT MAY ARRIVE
FRIDAY NIGHT OR SATURDAY. THE COLD FRONT WILL MOVE OFF THE COAST
SATURDAY NIGHT WITH HIGH PRESSURE BUILDING IN FROM THE NORTH FOR
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1100 PM SUNDAY...COASTAL FLOOD ADVISORY FOR ALONG THE CAPE
FEAR RIVER FROM WILMINGTON TO FORT FISHER HAS EXPIRED. THE GAGE
READING PEAKED AT 5.84 FT MLLW AT THIS EVENINGS HIGH TIDE AROUND
945 PM. THE READING 5.5 FT MLLW IS THE THRESHOLD USED FOR MINOR
COASTAL FLOODING TO COMMENCE.
THE COLD FRONT HAS BASICALLY STALLED AND IS ORIENTED NE-SW ACROSS
THE EASTERN CAROLINAS...ROUGHLY 15 TO 40 MILES INLAND FROM THE
IMMEDIATE COAST. THIS BOUNDARY WILL WILL PROVIDE A SOURCE OF LIFT
FOR CONVECTION OVERNIGHT. THE SFC LOW AND ASSOCIATED DYNAMICS
OVER COASTAL GA-SC IS MAKING SOME PROGRESS NE-WARD AND SHOULD
FURTHER INCREASE ITS FORWARD SPEED BY DAYBREAK MONDAY AS IT
ATTACHES TO THE STALLED BOUNDARY. WITH PWS ABOVE 2 INCHES ACROSS
THE MAJORITY OF THE ILM CWA...WEAK INSTABILITY...FORCING FROM THE
SFC BOUNDARY AND DYNAMICS ALOFT ASSOCIATED WITH THE SFC LOW...AND
FRICTIONAL CONVERGENCE FROM ONSHORE FLOW...POPS WILL REACH
CATEGORICAL FOR MUCH OF THE ILM CWA DURING THE PRE-DAWN MONDAY
HRS. HIGHEST QPF ALONG THE IMMEDIATE COAST...TRAILING LOWER AS ONE
PROGRESSES INLAND. HWO WILL MENTION ISOLATED FLOODING FROM THE
HEAVY RAINFALL...MAINLY FROM THE I-95 CORRIDOR EAST TO THE COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...WEAK LOW PRESSURE OVER THE GA/SC COAST MON
MORNING WILL TRACK NORTHEAST ALONG A FRONT STALLED ACROSS THE AREA
DURING THE DAY. LOW LEVEL CONVERGENCE AHEAD AND EAST OF THIS LOW
WILL HAVE PLENTY OF DEEP TROPICAL MOISTURE TO TAP INTO. PRECIPITABLE
WATER VALUES LATER MON TOP OUT AROUND 2.35 INCHES WHICH IS RIGHT
AROUND THE 99TH PERCENTILE FOR THIS TIME OF YEAR. WIDESPREAD HEAVY
RAIN IS EXPECTED ACROSS MUCH OF THE FORECAST AREA WITH ADDITIONAL
ENHANCEMENT AHEAD AND EAST OF THE LOW THANKS TO LIFT. EAST OF THE
LOWS TRACK SIGNIFICANT RAINFALL POTENTIAL WILL EXIST WITH RAINFALL
RATES OF 2.5 INCHES PER HOUR AND HIGHER POSSIBLE. DEEP SOUTHWEST
FLOW SHOULD KEEP STORM MOTION CLOSE TO 15 KT SO SLOW MOVING STORMS
WILL NOT BE A CONCERN BUT TRAINING COULD LEAD TO EXCESSIVE LOCALIZED
RAINFALL. GIVEN THE SO FAR SPOTTY NATURE OF CONVECTION THIS
AFTERNOON...LACK OF SIGNIFICANT RAINFALL IN THE LAST WEEK OR
SO...AND STORM MOTIONS GREATER THAN 10 KT DO NOT FEEL A NEED TO
RAISE AN AREA WIDE FLOOD WATCH AT THIS POINT IN TIME.
THE LOW SHOULD TRACK JUST INLAND OF THE COAST MON INTO MON NIGHT
PLACING COASTAL COUNTIES IN THE AREA FAVORED FOR HEAVIEST RAIN.
AREAS WEST OF THE LOW WILL STILL HAVE POTENTIAL FOR PERIODS OF HEAVY
RAIN BUT COVERAGE WILL BE A LITTLE LESS GIVEN THE SLIGHTLY LESS
FAVORABLE CONDITIONS...LIMITED CONVERGENCE AND WEAKER UPWARD
MOTION.
THE SURFACE LOW WILL START TO STRENGTHEN TUE AS IT LIFTS NORTHEAST.
THIS WILL HELP PUSH THE COLD FRONT OFF THE COAST AND USHER IN DRIER
AIR ALOFT. MID LEVEL RIDGE OVER THE SOUTHERN CONUS STARTS TO EXPAND
EAST AS THE PERIOD ENDS. LOW LEVEL MOISTURE TENDS TO LINGER BEHIND
FRONTS IN THESE SETUPS AND TUE MAY END UP ON THE CLOUDY
SIDE...ESPECIALLY ALONG THE NC COAST...WITH MOISTURE TRAPPED UNDER
THE BUILDING MID LEVEL RIDGE.
TEMPERATURES WILL RANGE FROM NEAR TO BELOW CLIMO. HIGHS WEST OF THE
LOW WILL END UP BELOW CLIMO MON BUT NEAR TO SLIGHTLY ABOVE CLIMO
TUE. ALONG THE COAST THE OPPOSITE WILL BE TRUE WITH HIGHS AROUND
CLIMO MON BUT NEAR TO SLIGHTLY BELOW CLIMO TUE OWING TO LINGERING
LOW CLOUD AND NORTHERLY FLOW. LOWS WILL REMAIN ABOVE CLIMO BOTH
NIGHTS WITH CLOUD COVER IN PLACE MON NIGHT AND MIXING/LINGERING
CLOUDS TUE NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...WEAK HIGH PRESSURE WILL REMAIN AT THE SURFACE
WHILE RIDGE IN THE MID TO UPPER LEVELS EASES BACK UP INTO THE
CAROLINAS THROUGH MID WEEK WITH PLENTY OF DRY AIR AND SUBSIDENCE
ALOFT. MAY INCLUDE A VERY LOW END CHC OF SHWRS BY EARLY THURS BUT
OVERALL EXPECT PLENTY OF SUNSHINE WITH SOME LOCALIZED CU
DEVELOPMENT AND POSSIBLY A STRAY SHWR. BY LATE THURS INTO FRI CHC
OF PCP WILL INCREASE AS RIDGE ALOFT GETS SUPPRESSED FARTHER SOUTH
AS A SHORTWAVE BEGINS TO DIG DOWN AS IT RIDES ACROSS THE GREAT
LAKES. THIS SHORTWAVE WILL PUSH A COLD FRONT INTO THE CAROLINAS BY
FRI INTO SATURDAY WITH MORE WIDESPREAD SHWR AND TSTMS EXPECTED
HEADING INTO THE WEEKEND. AS THE SHORTWAVE LIFTS NORTHEAST A BROAD
TROUGH WILL REMAIN OVER THE EASTERN CONUS. THEREFORE THE FRONT MAY
BE SLOWER TO MOVE OFF THE COAST...BUT LATEST GFS DOES SHOW SOME
DRYING BY SAT NIGHT INTO SUNDAY WITH DEWPOINT TEMPS DROPPING INTO
THE 60S. PCP WATER VALUES WILL BE BELOW 1.5 INCHES ON WED BUT WILL
BE UP TO 2 INCHES OR GREATER BY THURS EVENING AND WILL NOT COME
BACK DOWN UNTIL SUNDAY. THE FORECAST SHOULD START OUT DRY AND END
DRIER...BUT LOOKING LIKE A WET FIRST HALF OF THE WEEKEND.
TEMPS WILL WARM UP AGAIN THROUGH MID WEEK IN GREATER SUNSHINE AND
SLIGHT RISE IN H5 HEIGHTS AND LOW LEVEL THICKNESSES FROM WED THROUGH
FRI. EXPECT TEMPS BACK UP AROUND 90 OR SO BY THURS AND FRI. BY
SATURDAY CLOUDS AND SHWRS WILL AFFECT THE TEMPS AND THEN SOME COOLER
AIR WILL BEGIN TO MOVE IN BEHIND FRONT LATER ON SATURDAY INTO
SUNDAY...KEEPING TEMPS IN THE LOWER 80S BOTH OVER THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...UNSETTLED WEATHER WILL PERSIST THROUGH THE PERIOD AS A
SURFACE LOW SLOWLY MOVES UP THE COAST AND MERGES WITH A STALLING
COLD FRONT OVER THE EASTERN CAROLINAS. THE LATEST HRRR RUNS DEPICT
SHRA/TSRA INCREASING IN COVERAGE THIS MORNING. THE HEAVIEST ACTIVITY
IS EXPECTED ALONG THE COAST...WHERE DOWNPOURS COULD BRIEFLY REDUCE
VSBYS TO MVFR/IFR LEVELS. POST-FRONTAL IFR CIGS ARE ALREADY
SPREADING OVER OUR INLAND ZONES...SO THE STRATUS AT KLBT/KFLO WILL
LIKELY PERSIST THROUGH THE MORNING HOURS. EXPECT MAINLY MVFR CIGS AT
THE COASTAL TERMS...THOUGH PERSISTENT RAINFALL COULD LOWER CIGS
BELOW 1KFT AT TIMES.
EXPECT MORE WIDESPREAD SHOWERS/ISO TSTMS DURING THE DAY AS THE LOW
MOVES UP THE COAST. MVFR CONDITIONS ARE EXPECTED TO PREVAIL DURING
THE AFTN WITH BRIEF AND LOCALIZED AREAS OF IFR. THERE IS STILL SOME
UNCERTAINTY REGARDING THE SPEED AND TRACK OF THE LOW...WHICH MAKES
FOR A LOWER CONFIDENCE WIND FORECAST. IT LOOKS LIKE THE COAST WILL
SEE SOUTHEAST WINDS 10 KT WITH HIGHER GUSTS POSSIBLE IF THE LOW
DEEPENS. MEANWHILE THE INLAND TERMS WILL KEEP NORTHEAST WINDS AOB 10
KT FOR MUCH OF THE DAY. PCPN WILL TAPER OFF FROM SW TO NE AS THE LOW
CONTINUES MOVING NORTHWARD...WITH WINDS SHIFTING TO THE NORTH ON THE
BACKSIDE OF THE LOW NEAR THE END OF THE PERIOD.
EXTENDED OUTLOOK...CHANCE OF SHOWERS EARLY TUESDAY. OTHERWISE VFR
WILL PREVAIL THROUGH THURSDAY. SHOWERS/TSTMS RETURN ON FRIDAY AS
ANOTHER COLD FRONT APPROACHES OUR CWA.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 PM SUNDAY...UPDATED WINDS DUE TO THE POSITIONING OF THE
FRONTAL BOUNDARY JUST INLAND FROM THE COAST. LATEST OBS AND HRRR
TRENDS INDICATE ESE-SSE DIRECTIONS ACROSS THE ILM WATERS DUE TO
THE MEANDERING OF THIS FRONT. PORTIONS OF IT MAY COME WITHIN 15
MILES OR LESS FROM THE IMMEDIATE COAST AT TIMES BUT MODELS REMAIN
ADAMANT IN KEEPING IT INLAND. SIGNIFICANT SEAS REMAIN 2 TO 4 FT
WITH WIND WAVES DOMINATING THE SEAS SPECTRUM...IE. DOMINANT
PERIODS AROUND 5 SECONDS.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...WEAK LOW PRESSURE MOVING NORTHEAST ALONG A
FRONT STALLED JUST WEST OF THE WATERS WILL BRING ABOUT AN INCREASE
IN SOUTHERLY FLOW MON. SOLID 20 KT IS LIKELY AND CANNOT RULE OUT A
BRIEF PERIOD WHERE SPEEDS WILL APPROACH 25 KT...IF THE LOW IS A BIT
STRONGER OR FASTER MOVING THAN CURRENTLY FORECAST. INCREASE IN WINDS
WILL BUILD SEAS TO 3 TO 5 FT MON AND MON NIGHT. ALTHOUGH THERE IS
POTENTIAL FOR A BRIEF PERIOD OF 6 FT...ESPECIALLY IF STRONGER
SOLUTION WERE TO VERIFY...WILL KEEP SEAS CAPPED AT 5 FT FOR NOW
GIVEN AMOUNT OF UNCERTAINTY.
SURFACE LOW MOVES OFF TO THE NORTHEAST TUE PUSHING THE FRONT EAST OF
THE WATERS AND SETTING UP OFFSHORE FLOW. EXITING LOW IS SLOW TO
STRENGTHEN AND THE GRADIENT BEHIND THE BOUNDARY IS NOT VERY WELL
DEFINED. OFFSHORE WINDS WILL BE AROUND 10 KT ON TUE BEFORE BACKING
TO WEST-SOUTHWEST AND DROPPING BELOW 10 KT TUE NIGHT. OFFSHORE
COMPONENT TO WINDS WILL KEEP SEAS 2 FT OR LESS DURING THE SECOND
HALF OF THE PERIOD.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...WEAK HIGH PRESSURE OVER THE WATERS WILL
MAINTAIN LIGHT AND VARIABLE WINDS COMING AROUND TO THE SOUTH BY
THURS BUT REMAINING 10 KTS OR LESS. BY LATE THURS INTO FRI THE
S-SW WINDS WILL INCREASE UP TO 15 KTS KICKING SEAS UP A BIT.
OVERALL EXPECT SEAS 3 FT OR LESS THROUGH MOST OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/TRA
SHORT TERM...III
LONG TERM...RGZ
AVIATION...BJR/RJD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1236 AM EDT MON SEP 8 2014
.SYNOPSIS...
A COLD FRONT WILL STALL JUST OFF THE EASTERN NORTH CAROLINA COAST
TONIGHT. SLOW MOVING LOW PRESSURE WILL LIFT NORTHEAST ALONG THE
STALLED FRONT MONDAY AND MONDAY NIGHT. THE LOW WILL FINALLY LIFT
NORTHEAST OF THE REGION TUESDAY WITH THE TRAILING COLD FRONT
GRADUALLY DISSIPATING AS IT DRIFTS OFF THE COAST. OFFSHORE HIGH
PRESSURE WILL DOMINATE WEDNESDAY AND THURSDAY WITH ANOTHER COLD
FRONT APPROACHING FROM THE WEST LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1235 AM MONDAY...BASED ON SURFACE OBSERVATIONS IT NOW
APPEARS THAT THE SURFACE FRONT HAS DRIFTED SOUTH INTO THE CAPE
FEAR REGION. EASTERLY POST FRONTAL FLOW NOW IS OCCURRING ACROSS
ALL OF EASTERN NC LATE TONIGHT WITH ONLY SPOTTY LIGHT SHOWERS
OCCURRING. JUST TO THE NORTH OF THE BOUNDARY THUNDERSTORMS HAVE
ERUPTED OVER ONSLOW COUNTY WITH ADDITIONAL CONVECTION DEVELOPING
IN THE CAPE FEAR REGION AND LIFTING NORTH. THE 3 KM HRRR MODEL
TAKES THIS PRECIPITATION NORTH ACROSS EASTERN NC LATE TONIGHT.
THUS WILL HAVE POPS INCREASING TO LIKELY ALL AREAS AFTER 06Z AS
THE MODEL DEVELOP A SLOW MOVING FRONTAL WAVE TO THE SOUTHWEST AND
MOVE THIS FEATURE TOWARD EASTERN NC ON MONDAY. NO CHANGES NEEDED
TO THE TEMPERATURE FORECAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM TUESDAY/...
MODEL TRENDS AND CONCENSUS SUGGEST THE BEST CHANCES FOR HEAVIER
PRECIPITATION WILL PUSH WESTWARD ALONG A DEVELOPING WEDGE FRONT ON
MONDAY. WILL CONTINUE CATEGORICAL POPS INLAND AND TAPER BACK
SLIGHTLY TO HIGH LIKELY POPS NEAR THE COAST. THERE WILL BE A
CONTINUED THREAT FOR HEAVY RAIN AND LOCALIZED FLOODING JUST ABOUT
ANYWHERE IN THE FORECAST AREA AND MAY EVENTUALLY NEED TO ISSUE
FLOOD ADVISORIES OR WARNINGS IF HEAVIER/STEADIER RAIN FOCUSES IN
ONE PARTICULAR AREA. HIGHS IN THE UPPER 70S TO LOWER 80S WITH
MAINLY CLOUDY SKIES AND WIDESPREAD PRECIPITATION.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
AS OF 4 PM SUN...AN UNSETTLED/WET PERIOD EXPECTED TO CONTINUE
THROUGH TUE. THE COLD FRONT WILL REMAIN STALLED ACROSS THE AREA
MON NIGHT...WITH AN AREA OF LOW PRESSURE MOVING ALONG THE BOUNDARY
TUES INTO TUES NIGHT. THE STALLED BOUNDARY WILL BE A FOCUS FOR
OCCASIONAL HEAVIER PRECIPITATION WITH GOOD UPPER LEVEL DIVERGENCE
WITH THE REGION LOCATED IN THE RIGHT ENTRANCE OF THE UPPER JET
AND PIECES OF SHORT WAVE ENERGY PUSHING THRU THE LOW AMPLITUDE MID
LEVEL TROF OVER THE EASTERN STATES. MODEL PREFERENCES CONTINUE TO
SIDE WITH A GFE/ECMWF BLEND AS THE NAM CONTINUES TO SHOW A DEEPER
AND FASTER BIAS WITH THE SFC LOW TRACKING ACROSS THE AREA AND AS
SUCH HAVE INCREASED POPS MON NIGHT INTO TUES WITH A SLOWER
DEPARTURE OF THE LOW. FLOODING CONCERNS MAY CONTINUE INTO EARLY
TUES WITH ADDITIONAL RAINFALL AMOUNTS IN THE 1-2 INCH RANGE
POSSIBLE...WITH LOCALIZED HIGHER AMOUNTS POSSIBLE GIVEN THE HIGH
PWATS OF 2 TO 2.25 INCHES. HIGHS WILL BE HELD DOWN BY CLOUDS AND
PRECIP WITH MAX TEMPS UPPER 70S TO LOWER 80S TUE.
THE LOW IS PROGGED TO LIFT NE OF THE REGION TUES NIGHT WITH THE
FRONT FINALLY MOVING OFFSHORE WED...ALLOWING RIDGING/DEEP LAYER
DRYING TO BUILD INTO THE AREA MIDWEEK. ONLY ISOLATED SEA BREEZE
TYPE DIURNAL CONVECTION EXPECTED WED/THU AS SHORT WAVE RIDGE
SUPPRESSES MOST CONVECTION. RISING THICKNESS WILL RESULT IN HIGH
TEMPS MODERATING TO AT OR SLIGHTLY ABOVE NORMAL WED/THU...GENERALLY
HIGHS IN THE LOWER TO UPPER 80S.
ANOTHER COLD FRONT WILL MOVE INTO THE REGION LATE IN THE WEEK BUT
THE USUAL TIMING ISSUES CONTINUE REGARDING THE APPROACH AND
EVENTUAL PASSAGE OF THE FRONT. THERE IS ALMOST A 24 HR DIFFERENCE
BETWEEN THE 12Z GFS AND 12Z ECMWF IN REGARD TO THE TIMING OF THE
FRONT PUSHING SOUTH OF THE AREA LEADING TO BELOW AVERAGE
CONFIDENCE IN THE FORECAST DETAILS LATE IN THE WEEK. PRECIP COULD
BEGIN AS EARLY AS LATE THURS NIGHT WITH BEST CHANCES FRIDAY
AFTERNOON THROUGH SAT...THEN TAPER OFF FROM N TO S SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH MONDAY NIGHT/...
AS OF 1235 AM MONDAY...SUB VFR CONDITIONS ARE EXPECTED THROUGH THE
TAF PERIOD IN WIDESPREAD PRECIPITATION...HEAVY AT TIMES WITH
ASSOCIATED LOW CEILINGS AND VISIBILITIES. CONDITIONS WILL TEND TO
BE VARIABLE BUT THINK IFR CEILINGS WILL PREVAIL INTO MONDAY
MORNING THEN COULD LIFT TO MVFR BEFORE DROPPING AGAIN LATE
MONDAY/MONDAY NIGHT AS SLOW MOVING LOW PRESSURE MOVES INTO THE
AREA.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 4 PM SUN...WIDESPREAD SHOWERS/THUNDERSTORMS WILL BRING
PERIODS OF MVFR AND OCCASIONAL IFR CONDITIONS DURING AN UNSETTLED
WEATHER PERIOD INTO TUE NIGHT AS A SFC FRONT STALLS OVER AND LOW
PRES LIFTS ACROSS REGION. THERE IS A POTENTIAL FOR RADIATION FOG
TUE NIGHT IF SKIES SUFFICIENTLY CLEAR AS LIGHT WINDS WILL PRODUCE
A DECENT FOG SETUP ESPECIALLY WITH A SATURATED GROUND. GRADUAL
DRYING IS EXPECTED WED AND THURS AS HIGH PRES BUILDS INTO THE AREA
WITH PRED VFR CONDITIONS AND ONLY ISOL DIURNALLY DRIVEN
CONVECTION...HOWEVER THERE IS A CHANCE OF MVFR CIGS LINGERING INTO
WED WITH WRAP-AROUND MOISTURE ACROSS THE AREA BEHIND THE DEPARTING
LOW.
&&
.MARINE...
SHORT TERM /TONIGHT/...
AS OF 1235 AM MONDAY...FRONT IS NOW SOUTH OF THE WATERS WITH ALL
OF THE NEAR-SHORE BUOYS NOW REPORTING N/NNE WINDS. SPEEDS ARE 15
KNOTS OR LESS AND GENERALLY 5 TO 10 KNOTS OVER ALL BUT THE FAR
NORTHERN SECTIONS. PER LATEST 3 KM HRRR...WINDS SHOULD REMAIN NE/E
THROUGH THE NIGHT WITH SEAS AT 2 TO 4 FEET. THE PRESSURE GRADIENT
WILL TIGHTEN SOUTH OF THE FRONT AS LOW PRESSURE RIDES NE ALONG THE
BNDRY MONDAY AND MAY REACH 15-20 KT MONDAY AFTERNOON OVER SOUTHERN
AND CENTRAL WATERS. SEAS BUILD 3-5 FT IN RESPONSE TO THE WIND
INCREASE.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 4 PM SUN...A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS
EASTERN NC WITH AREA OF LOW PRESSURE SLOWLY LIFTING ALONG THE
FRONT MON NIGHT INTO WED. BELOW NORMAL CONFIDENCE IN THE MARINE
FORECAST AS MODELS NOT IN BEST AGREEMENT WITH TIMING AND
STRENGTH OF THE LOW. PREFERRED MODELS ARE A BLEND OF THE GFS/ECMWF
WHICH IS SLOWER AND WEAKER WITH THE LOW AND THE FORECAST GENERALLY
FOLLOWS THIS TREND WITH WINDS AROUND 10-20 KT. IF THE NAM ENDS UP
VERIFYING WINDS COULD BE SIGNIFICANTLY STRONGER...AND CURRENTLY
SHOWS WINDS AS HIGH AS 20-30 KT AHEAD OF THE LOW MON NIGHT. USED A
BLEND OF THE NWPS AND WAVEWATCH III WITH SEAS PRIMARILY AROUND 3-5
FT...HOWEVER IF THE NAM VERIFIES HIGHER SEAS WILL BE LIKELY. THE
LOW TRACKS OFF THE NC COAST WED WITH WINDS BECOMING LIGHT NW AS
PRESSURE GRADIENT BECOMES WEAK ALONG THE COAST. WINDS GENERALLY
LESS THAN 10KT WILL CONTINUE WED NIGHT INTO EARLY THU...BECOMING
S/SW AGAIN 10-15KT BY LATE THU AFTERNOON AHEAD OF ANOTHER COLD
FRONT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC/JME
SHORT TERM...BTC
LONG TERM...BTC/SK
AVIATION...JME/SK
MARINE...CTC/BTC/JME/SK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1216 PM CDT MON SEP 8 2014
.UPDATE...
ISSUED AT 1216 PM CDT MON SEP 8 2014
UPDATED THE FORECAST TO SCALE BACK THE SOUTHERN EXTENT OF THE
CLOUD COVER FOR EARLY THIS AFTERNOON. THE FRONT`S SOUTHERN
PROGRESSION HAS SLOWED DUE TO AFTERNOON HEATING SOUTH.
HOWEVER...THE LATEST MESOSCALE MODELS PROG THE FRONT TO ACCELERATE
SOUTHWARD DURING THE LATE AFTERNOON/EARLY EVENING HOURS WITH THE
LOSS OF DAYTIME HEATING. THE REMAINING FORECAST ELEMENTS ARE IN
GOOD SHAPE. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 911 AM CDT MON SEP 8 2014
A COLD FRONT CONTINUES TO PROGRESS THROUGH NORTHWEST NORTH DAKOTA
FASTER THAN PREVIOUSLY ANTICIPATED. FURTHERMORE...TRAILING STRATUS
IS QUITE A BIT MORE WIDESPREAD UPSTREAM IN CANADA. AS A
RESULT...UPDATED THE SKY GRIDS TO INCREASE CLOUD COVER NORTH BASED
ON THE CURRENT OBS AND 06Z NAM 1000MB-850MB LAYER RH TRENDS.
THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED
PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 634 AM CDT MON SEP 8 2014
GIVEN SATELLITE AND SURFACE OBSERVATION TRENDS THROUGH 11
UTC...THE COLD FRONT IS ARRIVING A BIT EARLIER INTO FAR NORTHEAST
MONTANA AND NORTHWEST NORTH DAKOTA THAN PREVIOUSLY FORECAST. THE
10 UTC RAP AND 06 UTC NAM HAVE CAPTURED THIS WELL...AND HAVE
BLENDED THE PREVIOUS FORECAST TO THEIR SOLUTIONS. THE RESULT...IS
HIGHS ONLY IN THE UPPER 50S ACROSS THE FAR NORTHWEST UNDER LOW
LEVEL STRATUS...AND UPPER 80S FOCUSED CLOSER TO THE SOUTH DAKOTA
BORDER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT MON SEP 8 2014
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE THE ONSET OF
A MAJOR PATTERN CHANGE LATER TODAY INTO TONIGHT.
CURRENTLY...ARCTIC COLD FRONT...MODIFIED/WARMED AS IT HAS MOVED
SOUTH ACROSS CENTRAL CANADA...CONTINUES TO PUSH SLOWLY SOUTHWARD
ACROSS THE CENTRAL CANADIAN PRAIRIE PROVINCES AHEAD OF/IN RESPONSE
TO A STRONG EMBEDDED IMPULSE ROTATING AROUND A DEEP AREA OF UPPER
LEVEL LOW PRESSURE BUILDING ACROSS THE NORTHERN HUDSON BAY REGION.
AHEAD OF THE FRONT...WAA SPREADING EAST ACROSS THE NORTHERN PLAINS
ALONG TO SOUTH OF A SFC TROUGH.
THE MODIFIED ARCTIC COLD FRONT WILL CONTINUE TO PUSH SOUTH
REACHING THE INTERNATIONAL BORDER 12-15Z...AND THROUGH WEST AND
CENTRAL NORTH DAKOTA LATER THIS EVENING. WILL INITIALLY SEE AN
INCREASE IF LOW TO MID LEVEL CLOUDS ACROSS THE NORTH...ALONG WITH
A WIND SHIFT FROM SOUTHERLY TO NORTHERLY. WILL KEEP THE FORECAST
DRY THROUGH THE AFTERNOON WHEN MOISTURE IS MORE LIMITED. THE
TIMING/PLACEMENT OF THE FRONT WILL CREATE A LARGE SPREAD IN
DAYTIME HIGH TEMPERATURES TODAY...WITH MID/UPPER 60S NORTH AND
MID/UPPER 80S SOUTH.
DEEP LAYER MOISTURE WILL FILTER SOUTHWARD AFTER 00Z BEHIND THE
FROPA...ALONG WITH A MODERATE NORTHEASTERLY UPSLOPE LOW LEVEL FLOW
COMPONENT DEVELOPING NORTH TO SOUTH WITH LOW PRESSURE BUILDING
ACROSS SOUTH DAKOTA. WILL MAINTAIN SLIGHT CHANCES FOR SHOWERS AS
COVERAGE APPEARS TO BE LIMITED. STRATUS DEVELOPMENT LOOKING LIKELY
SO KEPT SKY COVER ELEVATED. REMOVED THUNDER WITH LITTLE
INSTABILITY ADVERTISED BY MODELS. DESPITE THE 0C ISOTHERM ENTERING
MY NORTH LATE TONIGHT...CLOUD COVER SHOULD KEEP TEMPERATURES WELL
ABOVE FROST/FREEZING THRESHOLDS FOR TONIGHT/TUESDAY MORNING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON SEP 8 2014
MUCH COOLER WEATHER AND FROST POTENTIAL CONTINUE TO HIGHLIGHT THE
EXTENDED FORECAST.
THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN GOOD AGREEMENT
ON COOL HIGH PRESSURE BUILDING ACROSS NORTH DAKOTA TUESDAY THROUGH
THURSDAY...WITH THE POTENTIAL COMMENCEMENT OF RETURN FLOW ACROSS
THE NORTHERN PLAINS AND THE BEGINNING OF A WARMING TREND THIS
WEEKEND AS THE HIGH WEAKENS AND DEPARTS IN THE GREAT LAKES. FROST
IS POSSIBLE ACROSS WESTERN NORTH DAKOTA TUESDAY NIGHT...AND AREA
WIDE WEDNESDAY AND THURSDAY NIGHTS WITH LOWS IN THE 30S. DEPENDING
ON CLOUD COVER...SOME LOCATIONS MAY DROP BELOW FREEZING THURSDAY
NIGHT. IN REGARDS TO PRECIPITATION...ANY SIGNIFICANT PRECIPITATION
IS EXPECTED TO REMAIN TO OUR SOUTH AND EAST AS A COLORADO LOW
PROPAGATES INTO THE MISSISSIPPI VALLEY TUESDAY INTO WEDNESDAY.
SCATTERED RAIN SHOWERS ARE EXPECTED ON TUESDAY... WITH PERHAPS A
RELATIVELY DRY WEDNESDAY WITH SOME SUBSIDENCE BEHIND THE TUESDAY
SHORTWAVE. THE DISTURBANCE THAT HAD THE BEST POTENTIAL TO POSSIBLY
YIELD SOME SNOW ACROSS NORTH DAKOTA THURSDAY IS NOW FORECAST TO
MISS ALL BUT PERHAPS THE VERY FAR SOUTHWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1216 PM CDT MON SEP 8 2014
A STRONG COLD FRONT WILL CONTINUE TO SLOWLY PUSH SOUTH THIS
AFTERNOON THROUGH EARLY EVENING. IFR STRATUS ASSOCIATED WITH THE
FRONT MAY IMPACT KISN AND KMOT THIS EARLY AFTERNOON. MVFR TO NEAR
IFR STRATUS IS FORECAST TO OVERSPREAD ALL OF WESTERN AND CENTRAL
NORTH DAKOTA THIS EVENING AND CONTINUE THROUGH THE REMAINDER OF
THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...NH
LONG TERM...AYD
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
911 AM CDT MON SEP 8 2014
.UPDATE...
ISSUED AT 911 AM CDT MON SEP 8 2014
A COLD FRONT CONTINUES TO PROGRESS THROUGH NORTHWEST NORTH DAKOTA
FASTER THAN PREVIOUSLY ANTICIPATED. FURTHERMORE...TRAILING STRATUS
IS QUITE A BIT MORE WIDESPREAD UPSTREAM IN CANADA. AS A
RESULT...UPDATED THE SKY GRIDS TO INCREASE CLOUD COVER NORTH BASED
ON THE CURRENT OBS AND 06Z NAM 1000MB-850MB LAYER RH TRENDS.
THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED
PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 634 AM CDT MON SEP 8 2014
GIVEN SATELLITE AND SURFACE OBSERVATION TRENDS THROUGH 11
UTC...THE COLD FRONT IS ARRIVING A BIT EARLIER INTO FAR NORTHEAST
MONTANA AND NORTHWEST NORTH DAKOTA THAN PREVIOUSLY FORECAST. THE
10 UTC RAP AND 06 UTC NAM HAVE CAPTURED THIS WELL...AND HAVE
BLENDED THE PREVIOUS FORECAST TO THEIR SOLUTIONS. THE RESULT...IS
HIGHS ONLY IN THE UPPER 50S ACROSS THE FAR NORTHWEST UNDER LOW
LEVEL STRATUS...AND UPPER 80S FOCUSED CLOSER TO THE SOUTH DAKOTA
BORDER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT MON SEP 8 2014
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE THE ONSET OF
A MAJOR PATTERN CHANGE LATER TODAY INTO TONIGHT.
CURRENTLY...ARCTIC COLD FRONT...MODIFIED/WARMED AS IT HAS MOVED
SOUTH ACROSS CENTRAL CANADA...CONTINUES TO PUSH SLOWLY SOUTHWARD
ACROSS THE CENTRAL CANADIAN PRAIRIE PROVINCES AHEAD OF/IN RESPONSE
TO A STRONG EMBEDDED IMPULSE ROTATING AROUND A DEEP AREA OF UPPER
LEVEL LOW PRESSURE BUILDING ACROSS THE NORTHERN HUDSON BAY REGION.
AHEAD OF THE FRONT...WAA SPREADING EAST ACROSS THE NORTHERN PLAINS
ALONG TO SOUTH OF A SFC TROUGH.
THE MODIFIED ARCTIC COLD FRONT WILL CONTINUE TO PUSH SOUTH
REACHING THE INTERNATIONAL BORDER 12-15Z...AND THROUGH WEST AND
CENTRAL NORTH DAKOTA LATER THIS EVENING. WILL INITIALLY SEE AN
INCREASE IF LOW TO MID LEVEL CLOUDS ACROSS THE NORTH...ALONG WITH
A WIND SHIFT FROM SOUTHERLY TO NORTHERLY. WILL KEEP THE FORECAST
DRY THROUGH THE AFTERNOON WHEN MOISTURE IS MORE LIMITED. THE
TIMING/PLACEMENT OF THE FRONT WILL CREATE A LARGE SPREAD IN
DAYTIME HIGH TEMPERATURES TODAY...WITH MID/UPPER 60S NORTH AND
MID/UPPER 80S SOUTH.
DEEP LAYER MOISTURE WILL FILTER SOUTHWARD AFTER 00Z BEHIND THE
FROPA...ALONG WITH A MODERATE NORTHEASTERLY UPSLOPE LOW LEVEL FLOW
COMPONENT DEVELOPING NORTH TO SOUTH WITH LOW PRESSURE BUILDING
ACROSS SOUTH DAKOTA. WILL MAINTAIN SLIGHT CHANCES FOR SHOWERS AS
COVERAGE APPEARS TO BE LIMITED. STRATUS DEVELOPMENT LOOKING LIKELY
SO KEPT SKY COVER ELEVATED. REMOVED THUNDER WITH LITTLE
INSTABILITY ADVERTISED BY MODELS. DESPITE THE 0C ISOTHERM ENTERING
MY NORTH LATE TONIGHT...CLOUD COVER SHOULD KEEP TEMPERATURES WELL
ABOVE FROST/FREEZING THRESHOLDS FOR TONIGHT/TUESDAY MORNING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON SEP 8 2014
MUCH COOLER WEATHER AND FROST POTENTIAL CONTINUE TO HIGHLIGHT THE
EXTENDED FORECAST.
THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN GOOD AGREEMENT
ON COOL HIGH PRESSURE BUILDING ACROSS NORTH DAKOTA TUESDAY THROUGH
THURSDAY...WITH THE POTENTIAL COMMENCEMENT OF RETURN FLOW ACROSS
THE NORTHERN PLAINS AND THE BEGINNING OF A WARMING TREND THIS
WEEKEND AS THE HIGH WEAKENS AND DEPARTS IN THE GREAT LAKES. FROST
IS POSSIBLE ACROSS WESTERN NORTH DAKOTA TUESDAY NIGHT...AND AREA
WIDE WEDNESDAY AND THURSDAY NIGHTS WITH LOWS IN THE 30S. DEPENDING
ON CLOUD COVER...SOME LOCATIONS MAY DROP BELOW FREEZING THURSDAY
NIGHT. IN REGARDS TO PRECIPITATION...ANY SIGNIFICANT PRECIPITATION
IS EXPECTED TO REMAIN TO OUR SOUTH AND EAST AS A COLORADO LOW
PROPAGATES INTO THE MISSISSIPPI VALLEY TUESDAY INTO WEDNESDAY.
SCATTERED RAIN SHOWERS ARE EXPECTED ON TUESDAY... WITH PERHAPS A
RELATIVELY DRY WEDNESDAY WITH SOME SUBSIDENCE BEHIND THE TUESDAY
SHORTWAVE. THE DISTURBANCE THAT HAD THE BEST POTENTIAL TO POSSIBLY
YIELD SOME SNOW ACROSS NORTH DAKOTA THURSDAY IS NOW FORECAST TO
MISS ALL BUT PERHAPS THE VERY FAR SOUTHWEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 634 AM CDT MON SEP 8 2014
A STRONG COLD FRONT IS BEGINNING TO ARRIVE INTO FAR NORTHWEST NORTH
DAKOTA AS OF 1130 UTC...MOVING SOUTHEAST THROUGH THE DAY. IFR
STRATUS ASSOCIATED WITH THE FRONT MAY IMPACT KISN AND KMOT THIS
MORNING INTO THE EARLY AFTERNOON. MVFR TO NEAR IFR STRATUS IS
FORECAST TO OVERSPREAD ALL OF WESTERN AND CENTRAL NORTH DAKOTA
THIS EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...NH
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
635 AM CDT MON SEP 8 2014
.UPDATE...
ISSUED AT 634 AM CDT MON SEP 8 2014
GIVEN SATELLITE AND SURFACE OBSERVATION TRENDS THROUGH 11
UTC...THE COLD FRONT IS ARRIVING A BIT EARLIER INTO FAR NORTHEAST
MONTANA AND NORTHWEST NORTH DAKOTA THAN PREVIOUSLY FORECAST. THE
10 UTC RAP AND 06 UTC NAM HAVE CAPTURED THIS WELL...AND HAVE
BLENDED THE PREVIOUS FORECAST TO THEIR SOLUTIONS. THE RESULT...IS
HIGHS ONLY IN THE UPPER 50S ACROSS THE FAR NORTHWEST UNDER LOW
LEVEL STRATUS...AND UPPER 80S FOCUSED CLOSER TO THE SOUTH DAKOTA
BORDER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM CDT MON SEP 8 2014
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE THE ONSET OF
A MAJOR PATTERN CHANGE LATER TODAY INTO TONIGHT.
CURRENTLY...ARCTIC COLD FRONT...MODIFIED/WARMED AS IT HAS MOVED
SOUTH ACROSS CENTRAL CANADA...CONTINUES TO PUSH SLOWLY SOUTHWARD
ACROSS THE CENTRAL CANADIAN PRAIRIE PROVINCES AHEAD OF/IN RESPONSE
TO A STRONG EMBEDDED IMPULSE ROTATING AROUND A DEEP AREA OF UPPER
LEVEL LOW PRESSURE BUILDING ACROSS THE NORTHERN HUDSON BAY REGION.
AHEAD OF THE FRONT...WAA SPREADING EAST ACROSS THE NORTHERN PLAINS
ALONG TO SOUTH OF A SFC TROUGH.
THE MODIFIED ARCTIC COLD FRONT WILL CONTINUE TO PUSH SOUTH
REACHING THE INTERNATIONAL BORDER 12-15Z...AND THROUGH WEST AND
CENTRAL NORTH DAKOTA LATER THIS EVENING. WILL INITIALLY SEE AN
INCREASE IF LOW TO MID LEVEL CLOUDS ACROSS THE NORTH...ALONG WITH
A WIND SHIFT FROM SOUTHERLY TO NORTHERLY. WILL KEEP THE FORECAST
DRY THROUGH THE AFTERNOON WHEN MOISTURE IS MORE LIMITED. THE
TIMING/PLACEMENT OF THE FRONT WILL CREATE A LARGE SPREAD IN
DAYTIME HIGH TEMPERATURES TODAY...WITH MID/UPPER 60S NORTH AND
MID/UPPER 80S SOUTH.
DEEP LAYER MOISTURE WILL FILTER SOUTHWARD AFTER 00Z BEHIND THE
FROPA...ALONG WITH A MODERATE NORTHEASTERLY UPSLOPE LOW LEVEL FLOW
COMPONENT DEVELOPING NORTH TO SOUTH WITH LOW PRESSURE BUILDING
ACROSS SOUTH DAKOTA. WILL MAINTAIN SLIGHT CHANCES FOR SHOWERS AS
COVERAGE APPEARS TO BE LIMITED. STRATUS DEVELOPMENT LOOKING LIKELY
SO KEPT SKY COVER ELEVATED. REMOVED THUNDER WITH LITTLE
INSTABILITY ADVERTISED BY MODELS. DESPITE THE 0C ISOTHERM ENTERING
MY NORTH LATE TONIGHT...CLOUD COVER SHOULD KEEP TEMPERATURES WELL
ABOVE FROST/FREEZING THRESHOLDS FOR TONIGHT/TUESDAY MORNING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 343 AM CDT MON SEP 8 2014
MUCH COOLER WEATHER AND FROST POTENTIAL CONTINUE TO HIGHLIGHT THE
EXTENDED FORECAST.
THE 00 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN GOOD AGREEMENT
ON COOL HIGH PRESSURE BUILDING ACROSS NORTH DAKOTA TUESDAY THROUGH
THURSDAY...WITH THE POTENTIAL COMMENCEMENT OF RETURN FLOW ACROSS
THE NORTHERN PLAINS AND THE BEGINNING OF A WARMING TREND THIS
WEEKEND AS THE HIGH WEAKENS AND DEPARTS IN THE GREAT LAKES. FROST
IS POSSIBLE ACROSS WESTERN NORTH DAKOTA TUESDAY NIGHT...AND AREA
WIDE WEDNESDAY AND THURSDAY NIGHTS WITH LOWS IN THE 30S. DEPENDING
ON CLOUD COVER...SOME LOCATIONS MAY DROP BELOW FREEZING THURSDAY
NIGHT. IN REGARDS TO PRECIPITATION...ANY SIGNIFICANT PRECIPITATION
IS EXPECTED TO REMAIN TO OUR SOUTH AND EAST AS A COLORADO LOW
PROPAGATES INTO THE MISSISSIPPI VALLEY TUESDAY INTO WEDNESDAY.
SCATTERED RAIN SHOWERS ARE EXPECTED ON TUESDAY... WITH PERHAPS A
RELATIVELY DRY WEDNESDAY WITH SOME SUBSIDENCE BEHIND THE TUESDAY
SHORTWAVE. THE DISTURBANCE THAT HAD THE BEST POTENTIAL TO POSSIBLY
YIELD SOME SNOW ACROSS NORTH DAKOTA THURSDAY IS NOW FORECAST TO
MISS ALL BUT PERHAPS THE VERY FAR SOUTHWEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 634 AM CDT MON SEP 8 2014
A STRONG COLD FRONT IS BEGINNING TO ARRIVE INTO FAR NORTHWEST NORTH
DAKOTA AS OF 1130 UTC...MOVING SOUTHEAST THROUGH THE DAY. IFR
STRATUS ASSOCIATED WITH THE FRONT MAY IMPACT KISN AND KMOT THIS
MORNING INTO THE EARLY AFTERNOON. MVFR TO NEAR IFR STRATUS IS
FORECAST TO OVERSPREAD ALL OF WESTERN AND CENTRAL NORTH DAKOTA
THIS EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...NH
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS MEDFORD OR
224 PM PDT MON SEP 8 2014
.DISCUSSION...AS FAR AS THE GENERAL FORECAST GOES, THE PERIOD OF QUIET AND
UNEVENTFUL WEATHER WILL CONTINUE THROUGH AT LEAST THE NEXT WEEK.
MODELS ARE IN FAIRLY GOOD AGREEMENT CONCERNING THE OVERALL PATTERN,
WITH THE USUAL AND EXPECTED DIVERSION OF SOLUTIONS LATER IN THE
TERM. HAVE KEPT THE FORECAST TRENDED TOWARDS A GENERAL MODEL BLEND.
THE UPPER LOW CURRENTLY OVEN NORTHERN CALIFORNIA WILL WORK ITS WAY
EAST THROUGH TONIGHT AS A WEAK DRY COLD FRONT PUSHES IN FROM THE
NORTHWEST THIS EVENING. ALTHOUGH INSTABILITY IS WEAK, LAPSE RATES
ARE PRETTY STEEP IN SOME AREAS, AND MOISTURE WILL BE INCREASED IN
THE MID LEVELS. HIGH RESOLUTION NAM AND HRRR RUNS HAVE ALSO PRODUCED
VARYING AMOUNTS OF REFLECTIVITY OVER THE AREA. WITH ALL THIS IN
MIND, HAVE KEPT THE SLIGHT CHANCE OF THUNDER THAT WAS INTRODUCED
DURING THIS MORNING`S UPDATE, BUT CONFIDENCE REMAINS LOW.
AS MENTIONED ABOVE, THE WEAK FRONT WILL MOVE THROUGH THE AREA THIS
AFTERNOON AND EVENING, WITH TEMPERATURES COMING DOWN CLOSER TO
SEASONAL NORMS TUESDAY AND POSSIBLY WEDNESDAY. THE FRONT WILL ALSO
BRING GUSTY, BUT NOT STRONG, WINDS TO AREAS EAST OF THE CASCADES.
ONSHORE FLOW BEHIND THE FRONT WILL KEEP LOW CLOUDS AT THE COAST
LONGER DURING THE DAY WITH A GOOD CHANCE OF SEEING STRATUS SPREADING
INTO THE ROSEBURG AREA TONIGHT AND TUESDAY MORNING. BOTH THE NAM12
AND TO A CERTAIN EXTENT THE GFS BRING SOME MOISTURE SOUTH OF THE
UMPQUA DIVIDE EARLY TUESDAY MORNING. CONFIDENCE IS NOT VERY HIGH
THAT WE WILL SEE CLOUDS IN MEDFORD.
STEERING WINDS ARE EXPECTED TO TURN BACK TO THE NORTHWEST THIS
AFTERNOON AND STAY NW THROUGH TUESDAY. THIS SHOULD PUSH THE SMOKE
BACK INTO SISKIYOU COUNTY BUT COULD PRESENT PROBLEMS FOR YREKA AND
MOUNT SHASTA AREA.
EXPECT WARMING TREND TO RETURN AGAIN ON THURSDAY AND STAY WITH US
THROUGH NEXT WEEKEND...AS A MIDLEVEL RIDGE BUILDS IN OVERHEAD AND
THE THERMAL TROUGH RETURNS AND EXTENDS NORTHWARD WEST OF THE
CASCADES. TEMPERATURES WILL REMAIN NEAR NORMAL VALUES ON THE EAST
SIDE, AND THIS DIFFERENCE IN TEMPERATURE AND PRESSURE WILL LIKELY
RESULT IN SOME STRONGER EAST WINDS WEDNESDAY NIGHT INTO THURSDAY.
THIS WILL LEAD TO ANOTHER ROUND OF INCREASED FIRE CONCERNS INTO THE
WEEKEND. MODEL SOLUTIONS ARE SHOWING A POSSIBLE LARGER TROUGH
ENTERING THE AREA FROM THE NORTHEAST PACIFIC EARLY NEXT WEEK, BUT
CONFIDENCE IS LOW, ESPECIALLY GIVEN THE BLOCKY LOOKING PATTERN
PRODUCED UPSTREAM BY THE HEMISPHERICAL MODELS DURING THE SAME
PERIOD. GIVEN THE UNCERTAINTY, THE FORECAST REMAINS DRY THROUGH THE
TERM. -BPN
&&
.AVIATION...BASED ON THE 08/18Z TAF CYCLE...CURRENT VISIBLE IMAGE
SHOWS THE MARINE STRATUS GRADUALLY PEELING BACK TOWARDS THE COAST.
BASED ON THE SATELLITE TREND, VFR CONDITIONS COULD DEVELOP FOR A
COUPLE OF HOURS AT KOTH AFTER 22Z. UNTIL THEN IFR/LIFR CONDITIONS
WILL PERSIST WITH GUSTY NORTHERLY WINDS INTO EARLY EVENING. IFR/LIFT
CIGS WILL RETURN THIS EVENING AND CONTINUES INTO TUESDAY MORNING.
ELSEWHERE VFR CONDITIONS WILL CONTINUE FOR THE NEXT 18 HOURS, EXCEPT
FOR OCCASIONAL REDUCTION IN VIS DUE TO AREAS OF SMOKE IN WESTERN
SISKIYOU COUNTY. MODELS SUGGEST MARINE STRATUS WILL PUSH INTO THE
UMPQUA BASIN TOWARDS DAY BREAK TUESDAY WITH WIDESPREAD MVFR CIGS AND
PARTIAL MTN OBSCURATIONS. IT`S POSSIBLE SOME OF THE MARINE STRATUS
COULD. SPILL OVER THE UMPQUA DIVIDE, BUT SHOULD NOT EFFECT KMFR.
-PETRUCELLI
&&
.MARINE...UPDATED 220 PM PDT MON 8 SEP 2014...HIGH PRESSURE
WILL CONTINUE TO BUILD OFFSHORE THIS AFTERNOON AND A THERMAL TROUGH
WILL REDEVELOP ALONG THE COAST. THIS WILL RESULT IN THE RETURN OF
NORTH WINDS AND WIND WAVE DOMINATED SEAS THROUGH THE UPCOMING WEEK.
NORTH WINDS ARE LIKELY TO BE STRONGEST TUESDAY THROUGH WEDNESDAY WITH
GALES POSSIBLE SOUTH OF CAPE BLANCO. -WRIGHT
&&
.FIRE WEATHER...LATEST VISIBLE IMAGE SHOWS SOME CUMULUS BUILD UPS
AROUND THE SHASTA TRINITY NORTHEAST THROUGH MEDICINE BOW PEAK AND
SOUTHEAST MODOC COUNTY. SOME ARE DEVELOPING OVER THE CASCADES AND
HIGHER TERRAIN ON THE EAST SIDE. THE MODELS HINT AT VERY WEAK
INSTABILITY LATE THIS AFTERNOON INTO THIS EVENING. THE MODELS SHOW
SOME INSTABILITY IN THE AFOREMENTIONED AREAS, BUT IT`S MARGINAL AT
BEST. MODELS SOUNDINGS SHOW A WEAK CAP, SO IT`S POSSIBLE THAT THERE
MAY NOT BE A LOT OF VERTICAL DEVELOPMENT. IF ANY ISOLATED STORMS
WERE TO DEVELOP, IT WOULD MOST LIKELY BE BETWEEN 4-8 PM PDT. THE
MAIN CONCERN WILL BE GUSTY WEST TO NORTHWEST WINDS ON THE MID SLOPES
AND RIDGES LATE THIS AFTERNOON AND EVENING AS A DRY COLD FRONT MOVES
THROUGH. AN UPPER TROUGH WILL MOVE NORTH OF THE AREA TUESDAY AND THE
MODELS ARE SUGGESTING WEST TO NORTHWEST WINDS TUESDAY AFTERNOON AND
EVENING COULD BE HIGHER. THE GOOD NEWS IS THAT RELATIVE HUMIDITIES
WILL BE HIGHER, SO WERE NOT EXPECTING RED FLAG CONDITIONS TO BE MET.
THEREFORE WE`LL CONTINUE TO HEADLINE IT IN THE FORECAST. A STRONGER
SHORTWAVE WILL SWING THROUGH IDAHO AND WESTERN MONTANA WITH STRONG
HIGH PRESSURE BUILDING SOUTH INTO EASTERN WASHINGTON AND NORTHEAST
OREGON BY THURSDAY MORNING. A THERMAL TROUGH WILL DEVELOP ALONG THE
OREGON COAST AND THE PATTERN DEVELOPING IS FAVORABLE TO MODERATE TO
STRONG OFFSHORE FLOW ALONG THE CASCADES AND POSSIBLY WESTERN
SISKIYOU COUNTY. ALSO THE MODEL SOUNDINGS SHOW A SUBSIDENCE
INVERSION WHICH COULD RESULT IN MODERATE TO POOR RECOVERIES
WEDNESDAY NIGHT. THE COMBINATION OF MODERATE TO POOR RECOVERIES AND
WIND COULD WARRANT RED FLAG CONDITIONS, BUT THERE`S STILL TIME TO
EVALUATE THIS. FOR NOW WE`LL HEADLINE FOR THIS POTENTIAL JUST TO
RAISE AWARENESS TO THE USERS. -PETRUCELLI
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM
PDT WEDNESDAY FOR PZZ356-376.
HAZARDOUS SEAS WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT
WEDNESDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 5 PM TUESDAY TO 11 PM PDT
WEDNESDAY FOR PZZ350-370.
GALE WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR
PZZ376.
$$
BPN/MAP/TRW
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1231 PM CDT MON SEP 8 2014
.AVIATION 18Z DISCUSSION...
LOW CLOUDINESS TO PERSIST FOR A FEW MORE HOURS BUT WILL BEGIN TO
BREAK UP TOWARD AND BEYOND 00Z. LOW LEVEL MOISTURE WILL STILL
REMAIN...HOWEVER...AND FOG FORMATION CAN BE EXPECTED OVERNIGHT.
SOME SCT TO BKN LOW LEVEL CIGS CAN AGAIN BE EXPECTED AROUND 12Z
TOMORROW...MAINLY ACROSS THE PLATEAU AREA.
&&
.PREV DISCUSSION... /ISSUED 935 AM CDT MON SEP 8 2014/
DISCUSSION...
LOW CLOUDINESS HANGING ON ACROSS MUCH OF THE MID STATE THIS
MORNING. THE CLEARING LINE EXTENDS FROM JUST EAST OF CKV SOUTHWEST
THROUGH LOBELVILLE. THE LATEST 12Z SOUNDING PAIRED WITH THE NAM
THINKING INDICATES THAT THESE CLOUDS ARE GOING TO BE RATHER TOUGH
TO DISLODGE. THEREFORE...FOR THE UPDATE...WILL GO AHEAD AND LOWER
TEMPS A GOOD 3-5 DEGREES OR SO...MAINLY FOR THE EASTERN HALF OF
THE AREA. WILL ADJUST SKY GRIDS ACCORDINGLY.
OTW...WILL KEEP A SLIGHT CHANCE OF SHOWERS AND TSTMS GOING ACROSS
THE PLATEAU. LATEST HRRR DOES SHOW SOME CONVECTIVE DEVELOPMENT
THIS AFTERNOON. WILL REMOVE THE MORNING 12Z-18Z PART OF THE
SLIGHT CHANCE WEATHER GRID.
UPDATE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 653 AM CDT MON SEP 8 2014/
UPDATE...FOR 12Z AVIATION FORECASTS.
AVIATION...BAND OF LOW CLOUDS THAT COVERED THE SOUTHEASTERN TWO-
THIRDS OF MIDDLE TN EARLY THIS MORNING, WILL SLOWLY BREAK FROM THE
WEST. MVFR CIGS ARE EXPECTED TO HOLD AT BNA THROUGH 18Z, WITH CSV
HOLDING ON TO IFR CONDITIONS THROUGH 15Z, THEN MVFR THROUGH AT
LEAST 20Z. MEANWHILE, CKV SHOULD CONTINUE TO ENJOY VFR CONDITIONS.
FOR TONIGHT...EXPECT CKV AND BNA TO EXPERIENCE VFR CONDITIONS,
WHILE CSV WILL PROBABLY STILL BE PESTERED BY PERIODS OF LOW CLOUDS
AND FOG, ESPECIALLY DURING THE LATTER PART OF THE NIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
935 AM CDT MON SEP 8 2014
.DISCUSSION...
LOW CLOUDINESS HANGING ON ACROSS MUCH OF THE MID STATE THIS
MORNING. THE CLEARING LINE EXTENDS FROM JUST EAST OF CKV SOUTHWEST
THROUGH LOBELVILLE. THE LATEST 12Z SOUNDING PAIRED WITH THE NAM
THINKING INDICATES THAT THESE CLOUDS ARE GOING TO BE RATHER TOUGH
TO DISLODGE. THEREFORE...FOR THE UPDATE...WILL GO AHEAD AND LOWER
TEMPS A GOOD 3-5 DEGREES OR SO...MAINLY FOR THE EASTERN HALF OF
THE AREA. WILL ADJUST SKY GRIDS ACCORDINGLY.
OTW...WILL KEEP A SLIGHT CHANCE OF SHOWERS AND TSTMS GOING ACROSS
THE PLATEAU. LATEST HRRR DOES SHOW SOME CONVECTIVE DEVELOPMENT
THIS AFTERNOON. WILL REMOVE THE MORNING 12Z-18Z PART OF THE
SLIGHT CHANCE WEATHER GRID.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 653 AM CDT MON SEP 8 2014/
UPDATE...FOR 12Z AVIATION FORECASTS.
AVIATION...BAND OF LOW CLOUDS THAT COVERED THE SOUTHEASTERN TWO-
THIRDS OF MIDDLE TN EARLY THIS MORNING, WILL SLOWLY BREAK FROM THE
WEST. MVFR CIGS ARE EXPECTED TO HOLD AT BNA THROUGH 18Z, WITH CSV
HOLDING ON TO IFR CONDITIONS THROUGH 15Z, THEN MVFR THROUGH AT
LEAST 20Z. MEANWHILE, CKV SHOULD CONTINUE TO ENJOY VFR CONDITIONS.
FOR TONIGHT...EXPECT CKV AND BNA TO EXPERIENCE VFR CONDITIONS,
WHILE CSV WILL PROBABLY STILL BE PESTERED BY PERIODS OF LOW CLOUDS
AND FOG, ESPECIALLY DURING THE LATTER PART OF THE NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 86 65 90 70 / 10 05 0 05
CLARKSVILLE 85 61 88 68 / 05 05 0 05
CROSSVILLE 79 64 83 68 / 30 10 20 05
COLUMBIA 85 66 90 67 / 10 05 0 05
LAWRENCEBURG 85 66 89 68 / 10 05 05 05
WAVERLY 85 63 88 69 / 05 05 0 05
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1140 PM CDT SUN SEP 7 2014
.AVIATION...
/06Z TAFS/
Patchy stratus with MVFR ceilings possible daybreak into into mid
morning. Otherwise light winds and mid level clouds will prevail
overnight with south winds increasing to 5-10 KTS mid morning. With
light winds and evening rainfall near KSOA and KJCT, there is the
potential for patchy fog, mainly MVFR, near sunrise. However, mid
level clouds and morning stratus may limit widespread formation.
&&
.PREV DISCUSSION... /ISSUED 635 PM CDT SUN SEP 7 2014/
AVIATION...
/00Z TAFS/
Thunderstorm outflow boundary will move through KSJT around 0030Z,
temporarily shifting winds to the south with gusts to 20 KTS.
Thunderstorms will be in the vicinity until 2Z. With low levels of
the atmosphere remaining moist, stratus expected with MVFR CIGS late
tonight, beginning at climatologically favorable times and
scattering out mid to late Monday morning.
PREV DISCUSSION... /ISSUED 313 PM CDT SUN SEP 7 2014/
SHORT TERM...
(Tonight and tomorrow)
The quasi-stationary front is currently analyzed very near the
southern border of the CWA, roughly along a line from Sheffield, to
Rock Springs, to San Antonio. Skies cleared by midday across the
I-10 corridor, allowing temperatures to warm into the mid 80s.
MLCAPE values around 1000-1500 J/kg are present from Ozona to
Junction per the RAP Mesoanalysis, but CINH is no longer a concern
in this area. Scattered showers and thunderstorms have developed in
the vicinity of this boundary and will move to the northwest during
the afternoon and evening hours. Rain chances tonight will primarily
be limited to locations south of a Sterling City to Brownwood line.
The primary concern will be locally heavy rainfall given the slow
storm motions and precipitable water values around 1.75". This could
result in minor flooding, mainly in urban areas. Low temperatures
tonight should be in the upper 60s.
On Monday, we`ll maintain a moist airmass across West Central TX.
Precipitable water values are progged to remain at or above 1.60",
but the surface boundary is progged to wash out as southerly flow
resumes across the region. The loss of a low-level forcing mechanism
will limit rain chances. However, with temperatures warming into the
lower 90s, we should still see diurnal isolated convection across
the area. The best rain chances will be over the northwest Hill
Country, but isolated showers and thunderstorms will be included for
much of the area east of a Sonora, to San Angelo, to Sweetwater
line.
Johnson
LONG TERM...
(Tomorrow night through Sunday)
A cold front will bring a chance of showers and thunderstorms and
cooler temperatures for the latter part of the work week...
Above normal temperatures are forecast on Tuesday, with highs
ranging from the lower to mid 90s across the Interstate 10 corridor,
to the mid to upper 90s across the Big Country. Overnight lows will
be int he mid 70s. In the meantime, an upper level trough will move
into the Northern Rockies, and then eventually into the Northern
Plains, sending a cold front into the northern Big Country Wednesday
evening. Ahead of the cold front, compressional heating will result
in unseasonably hot temperatures on Wednesday. Highs will generally
be in the mid to upper 90s.
Models continue to have timing differences with regard to the
aforementioned cold front. Both the ECMWF and the GFS bring a front
into the Big Country Wednesdays night, then eventually slowly move
it through much of the rest of West Central Texas during the day
Thursday. Showers and thunderstorms are forecast to develop along
the front, with the best chance across the Big Country initially,
then better chances spreading south into much of the rest of the
area Thursday into Thursday night. High temperatures on Thursday
will be dependent on the timing of the front and any associated
rainfall. For now, the forecast reflects highs in the mid 80s across
the Big Country to the lower 90s across the Interstate 10 corridor.
Beyond Thursday, the GFS pushes the front through the area, while
the ECMWF dissipates the boundary, with a stronger cold front moving
through during the day on Friday. For now, the forecast was geared
toward the faster GFS solution, with PoPs decreasing from north to
south Friday. If the ECMWF solution were to verify, higher PoPs
would linger into Friday/Friday night. Highs on Friday were trended
down, given the expected cloud cover and cold air advection. Highs
will range from the lower 70s in the Big Country to near 80 along
the Interstate 10 corridor. These temperatures may eventually need
to be trended down a bit. A slow warm up is forecast into next
weekend.
Daniels
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 66 91 71 96 75 / 10 10 5 5 5
San Angelo 67 92 71 96 75 / 20 10 5 5 5
Junction 68 90 71 95 74 / 20 20 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/04
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1000 PM CDT TUE SEP 9 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 1000 PM CDT TUE SEP 9 2014
WILL CONTINUE FLOOD WATCH AS SYSTEM STILL APPEARS IT WILL COME
TOGETHER ACROSS THE STATE...THOUGH THERE COULD BE TWO AREAS OF
MAXIMUM RAIN WITH ONE ACROSS THE NORTH AND ANOTHER SOUTH. SUBSTANTIAL
LIFT...STRONG LOW-LEVEL JET...AND HIGH PRECIPITABLE WATER VALUES
SHOULD RESULT IN WIDESPREAD 1+ INCH VALUES. HEAVIEST RAIN SHOULD
FALL BETWEEN ABOUT 09Z AND 15Z.
&&
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 245 PM CDT TUE SEP 9 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG
COLD FRONT MOVING SOUTHEAST ACROSS NORTHERN MINNESOTA AND SOUTH
DAKOTA...WHILE LOW PRESSURE IS EMERGING INTO WESTERN KANSAS. AN
ISOLATED THUNDERSTORM DROPPED A QUARTER OF AN INCH OF RAIN OVER
WAUSAU EARLIER THIS MORNING WITHIN A MODEST MOISTURE AXIS BUT
DIMINISHED BY MIDDAY. OTHERWISE...NO OTHER CONVECTION HAS DEVELOPED
SO FAR TODAY. THUNDERSTORM ACTIVITY CONTINUES TO EXPAND OVER
NEBRASKA AND IOWA IN AN AREA OF MOISTURE CONVERGENCE AT 850MB. AS
LOW PRESSURE MOVES EAST AND THE LLJ MATURES THIS EVENING...THIS AREA
WILL DRAW ATTENTION FOR THE POTENTIAL OF SEVERE WEATHER AND HEAVY
RAIN DOWNSTREAM OVER CENTRAL AND NORTHEAST WISCONSIN LATER TONIGHT.
ANOTHER AREA OF RAIN CONTINUES TO DEVELOP OVER THE EASTERN DAKOTAS.
AS THESE SYSTEMS MOVE EAST...SEVERE WEATHER AND HEAVY RAIN POTENTIAL
ARE THE MAIN FORECAST CONCERNS.
TONIGHT...FOLLOWED THE ECMWF AND SREF FOR THE DETAILS OF THIS
FORECAST...WHICH IS PREFERRED BY HPC AND SUPPORTED BY THE ENSEMBLE
MEANS. THESE MODELS SHOW THAT THE STRONG COLD FRONT OVER THE
NORTHERN PLAINS WILL SAG SOUTH INTO NORTH-CENTRAL WISCONSIN THIS
EVENING AS LOW PRESSURE TRACKS NORTHEAST ACROSS THE CENTRAL PLAINS.
AHEAD OF THIS LOW...MID-LEVEL FLOW WILL BE BACKING WHILE INCREASING
AT THE SAME TIME...LEADING TO INCREASING ISENTROPIC ASCENT IN THE
PRESENCE OF MID-LEVEL LAPSE RATES BETWEEN 6-7 C/KM THROUGH THE
EVENING. WEAK SHORTWAVE ENERGY AND UPPER DIVERGENCE WILL ALSO BE
APPROACHING BY LATE IN THE EVENING. THIS ALL POINTS TO INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS FROM WEST TO EAST THROUGH THE
EVENING. PRECIP MAY BE MORE OF THE SCATTERED VARIETY DURING THE
EVENING...BUT THE MAIN SHOW LOOKS TO ARRIVE AFTER MIDNIGHT FROM THE
SOUTHWEST. AS THE LOW MOVES TOWARDS FAR NORTHEAST IOWA OR SOUTHWEST
WISCONSIN...THE NOSE OF THE LLJ WILL IMPINGE ON CENTRAL AND
NORTHEAST WISCONSIN. OUTSTANDING MOISTURE TRANSPORT WILL ADVECT IN
PWATS GREATER THAN 2 INCHES WHILE STRONG MID-LEVEL FGEN WILL BE
FOCUSED ON THE NOSE OF THE LLJ. ELEVATED INSTABILITY WILL PEAK
DURING THE EVENING HOURS...SO SOME POTENTIAL FOR SEVERE CONVECTION
WITH DAMAGING WIND GUSTS TO REACH CENTRAL WISCONSIN ALONG THE
LEADING EDGE OF ANY THUNDERSTORMS MOVING NORTHEAST OUT OF IOWA. BUT
INSTABILITY RAPIDLY WANES AFTER MIDNIGHT...LEAVING HEAVY RAINFALL AS
THE MAIN HAZARD. ALTHOUGH THERE REMAINS SOME UNCERTAINTY WITH THE
TRACK OF THE SURFACE LOW...THE HEAVIEST RAINFALL SHOULD FALL ON THE
NOSE OF THE LLJ WHICH IS PROJECTED TO PUSH ACROSS CENTRAL AND
NORTHEAST WISCONSIN OVERNIGHT INTO WEDNESDAY MORNING. 1.5 TO 2.5
INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS ARE POSSIBLE OVER CENTRAL
WISCONSIN BY MORNING.
WEDNESDAY...LOW PRESSURE WILL TRACK TOWARDS THE COAST LINE OF
EAST-CENTRAL OR NORTHEAST WISCONSIN BY 18Z WED. THE HEAVIEST OF
RAIN WILL BE ONGOING ON THE NOSE OF THE LLJ OVER NORTHEAST
WISCONSIN. LOOKING FOR THE SAME MAGNITUDE OF AMOUNTS IN THIS REGION
COMPARED TO CENTRAL WISCONSIN...1.5 TO 2.5 INCHES WITH LOCALLY
HIGHER AMOUNTS. THE HEAVY RAIN WILL PULL OUT WEDNESDAY AFTERNOON AS
NORTHWEST WINDS BEHIND THE SYSTEM DRAWS IN MUCH COLDER AIR INTO
NORTH-CENTRAL WISCONSIN. A WIDE RANGE OF HIGH TEMPERATURES WILL BE
PRESENT TOMORROW...RANGING FROM THE MIDDLE 50S NORTH TO THE LOWER
70S SOUTHEAST.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 245 PM CDT TUE SEP 9 2014
COOLER TEMPERATURE TRENDS AND PCPN CHANCES WILL BE THE FOCUS
DURING THIS PERIOD.
REMAINING SHOWERS FROM THE STRONG WEDNESDAY SYSTEM WILL DEPART TO
THE NORTHEAST BUT SMALL SHOWER CHANCES WILL LINGER INTO THURSDAY OVER
THE NORTH DUE TO CAA INSTABILITY OVER LAKE SUPERIOR. BLUSTERY
NORTH WINDS WILL BRING A FEEL OF FALL TO THE AREA.
HIGH PRESSURE WILL REMAIN SETTLED OVER THE NORTHERN PLAINS
THURSDAY NIGHT WITH SUBTLE CAA CONTINUING. SOME POTENTIAL OF FROST
FRIDAY MORNING OVER THE NORTH BUT WILL DEPEND ON DIMINISHING WINDS
AND CLOUDS. CLOUDS MAY ALREADY BE ON THE INCREASE WITH THE
APPROACH OF A DEEP MID LEVEL TROUGH OR CLOSED UPPER LOW
SYSTEM. THIS SYSTEM WILL BRING A CHANCE OF SHOWERS TO THE AREA
WHICH WILL LINGER INTO SATURDAY MORNING.
COOL HIGH PRESSURE WILL THEN BUILD INTO THE THE GREAT LAKES REGION
FOR THE WEEKEND TO PROVIDE MORE CHANCES OF FROST...AND POSSIBLE
HEADLINES. AGAIN WINDS MAY BE AN ISSUE SINCE THE CENTER OF THE
HIGH SLIDES INTO CENTRAL ILLINOIS SATURDAY NIGHT.
RETURN FLOW WILL BEGIN TO BRING MODERATING WARMER TEMPS INTO THE
AREA SUNDAY FOLLOWED WITH ANOTHER CHANCE OF SHOWERS WITH A
POSSIBLE FRONTAL SYSTEM FOR EARLY NEXT WEEK.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1000 PM CDT TUE SEP 9 2014
EXPECT CONDITIONS TO CONTINUE TO DETERIORATE OVERNIGHT AS LOW
PRESSURE MOVES INTO THE STATE. ALREADY LOCAL IFR CIGS AND VSBYS
IN FOG ALONG LAKE MICHIGAN. LARGE AREA OF SHOWERS AND
THUNDERSTORMS MOVING NORTHEAST AHEAD OF LOW. LIFR CONDITIONS ARE
LIKELY AT RHI AND AUW/CWA AND POSSIBLY GRB/ATW/MTW OVERNIGHT
THROUGH WEDNESDAY MORNING. IMPROVING CONDITIONS SHOULD OCCUR
WEDNESDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 245 PM CDT TUE SEP 9 2014
WHILE A SOAKING RAIN OF 1.00 TO 1.50 IS EXPECTED FOR
ALL LOCATIONS TONIGHT INTO WEDNESDAY...VERY CHALLENGING FORECAST
WITH DETERMINING THE AXIS OF HEAVIER RAINFALL DUE TO THE TRACK OF
THE SURFACE LOW. ECMWF TRACKS PLACES THE MAX OF 2-3 INCHES OVER
CENTRAL TO NORTHEAST WISCONSIN...NAM MUCH FURTHER NORTH WHILE THE
GEM AND MAV FOCUS OVER THE SOUTH HALF OF THE STATE INCLUDING
BRUSHING PARTS OF EAST CENTRAL WISCONSIN. TO COMPLICATE THE
SITUATION...RADAR TRENDS OVER THE CENTRAL PLAINS SHOWING SOME SPLIT
IN THE RAIN REGIONS. THE SOUTHERN REGION OF HEAVY RAINFALL OVER
SOUTHWEST IOWA IS THE PRIMARY REGION OF CONCERN AND WILL BE THE
FOCUS OF LATER NIGHT HEADLINES. REGARDLESS...THE FLOOD WATCH WILL
CONTINUE FOR THE ENTIRE AREA STARTING LATE THIS EVENING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH WEDNESDAY EVENING FOR WIZ005-010>013-018>022-
030-031-035>040-045-048>050-073-074.
&&
$$
UPDATE.........JKL
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......JKL
HYDROLOGY......TDH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
945 PM CDT TUE SEP 9 2014
.UPDATE...
WILL BE HOLDING ON TO FLASH FLOOD WATCH AS RAP FORECAST SOUNDINGS
AROUND 4 AM SHOW EXTREMELY STRONG OMEGA THAT CROSSES THE CWA
BETWEEN 08Z AND 15Z...PW/S IN THE 2 TO 2.2 INCH RANGE AND WARM
CLOUD DEPTH OF 13K FT WITH A LOW-LEVEL JET AROUND 50 KTS NOSING
INTO THE SW CORNER OF WI AROUND 06Z AHEAD OF RAPIDLY DEEPENING
SYSTEM THAT ACCELERATES INTO WESTERN WI BY 12Z WED.
SOME CONCERN ABOUT QPF AMOUNTS GIVEN INITIAL...MAINLY STRATIFORM
PCPN MOVING INTO CWA NOW...BUT CANT IGNORE THE ROBUST LIFT AND
MOISTURE MOVING IN AHEAD OF STRENGTHENING SYSTEM. WPC HAS QPF
BULLSEYE SOUTH INTO NRN IL...WITH A LESSER SECONDARY DEFORMATION
ZONE MAXIMA OVER THE ERN U.P./NRN LK MICHIGAN...WHILE LATEST NAM
CLIPS FAR SRN WI WITH A 2 INCH MAX...AND A HIGHER DEFORMATION ZONE
MAX THAT JUST MISSES TO THE NW.
WILL ADJUST QPF A BIT BUT BASICALLY LEAVE AMOUNTS INTACT WITH THE
POTENTIAL FOR HEAVY RAIN AFTER 06Z...AND PROBABLY CLOSER TO
09Z...THROUGH 12Z-15Z OVER THE CWA.
&&
.AVIATION/06Z TAFS/...
WHILE THERE MAY BE A FEW SPOTTY MVFR CIGS/VSBYS WITH STRATIFORM
PCPN CROSSING CWA NOW...EXPECT VFR CONDITIONS TO NOT PERMANENTLY LOWER
TO MVFR UNTIL SHOWERS AND STORMS MOVE IN AFTER 06Z AT KMSN AND
AFTER 09Z AT EASTERN TAF SITES. WINDS AROUND 3K FT WILL JUMP TO
AROUND 50 KTS BUT ENOUGH GRADIENT BELOW AS DEEP LOW CROSS SW TO NE
ACROSS STATE FOR SURFACE WINDS TO BE STRONG ENOUGH TO NOT NEED
LLWS IN TAFS.
STRONG COLD ADVECTION BEHIND LOW WILL BRING IFR CIGS IN SPITE OF
GUSTY WEST TO NORTHWEST WINDS THAT WILL SLOWLY LOWER AFTER 00Z AS
LOW PULLS AWAY.
.MARINE...SMALL CRAFT ADVISORY TIMES LOOK GOOD AND WILL BE KEPT.
MARINE DENSE FOG FOR NRN ZONES MAY BE DROPPED EARLY IF INCREASING
WINDS BREAK UP THE FOG...BUT EVEN WITH THE STRONGER WINDS...THE
HIGHER DEW POINT AIR MOVING OVER THE COOLER WATERS OFF OF
SHEBOYGAN AND PT WASHINGTON MAY KEEP ADVECTION FOG DENSE ENOUGH
FOR HEADLINE TO CONTINUE TO EXPIRATION.
&&
.PREV DISCUSSION... /ISSUED 220 PM CDT TUE SEP 9 2014/
TONIGHT AND WEDNESDAY - CONFIDENCE...MEDIUM
LOW PRESSURE WILL CONTINUE TO INTENSIFY AS IT APPROACHES WI TONIGHT.
IMPRESSIVELY STRONG 850 LLJ AVERAGING 55 TO 65 KNOTS WILL TAKE AIM
ON SRN WI LATER TONIGHT. SOUTHWEST UPPER JET WILL ENHANCE UPPER
DIVERGENCE. PRECIPITABLE WATER VALUES EXCEED 2 INCHES WITH BUFKIT
SOUNDINGS SHOWING A MOIST COLUMN THROUGH AN APPRECIABLE DEPTH. STORM
MOTIONS WILL BE ON THE HIGH SIDE BUT EXPECTING VERY EFFICIENT RAINFALL
RATES ON THE ORDER OF 1-2 IN/HOUR AT TIMES. THERE ARE STILL SOME MODEL
DIFFERENCES ON PLACEMENT OF FEATURES. THE MOST DIRECT BULLSEYE FOR
SRN WI IS THE GFS WITH THE ECMWF KEYING ON THE NRN CWA. MEANWHILE
THE GEM IS SKEWED FURTHER SOUTH INTO NRN IL WITH THE HEAVIER AXIS
INTO SE WI. MEANWHILE THE NAM HAS HEAVIEST PRECIP WITH DEF ZONE
PRECIP IN NW WI WITH A CONVECTIVE BAND INTO SRN WI. SO THIS ALL
POINTS TO THE WATCH WE HAVE. IT IS JUST A WATCH AND THERE IS STILL
SOME MODEL UNCERTAINTY ON EXACTLY HOW THIS WILL PLAY OUT. BUT GIVEN
THE POTENTIAL LAID OUT BY THE MODELS FROM A PURELY QPF STANDPOINT
THE WATCH IS CERTAINLY MERITED. THIS WILL IMPACT THE MORNING RUSH
HOUR AS WELL. STILL CONCERN FOR SOME HEFTY WINDS WITH ANY STORM CELL
AS THE STRONGER WINDS ALOFT GET TAPPED INTO AND BROUGHT DOWN TO THE
SURFACE VIA DOWNWARD MOMENTUM TRANSFER/WET MICROBURST IDEA. EXPECTING
THINGS TO WIND DOWN QUITE RAPIDLY LATE MORNING INTO EARLY AFTERNOON.
LLJ WILL SHIFT EAST AND NW WINDS AND LLVL CAA WILL BEGIN IN THE WAKE
OF THE FRONT. 2 METER TEMP PROGS SHOW RAPID DROPOFF IN SFC TEMPS DURG
THE AFTN THOUGH MOS LESS PRONOUNCED ON THE COOL DOWN. EXPECT SOME
POST-FRONTAL DROPOFF THOUGH.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE IS
HIGH.
STRONG COLD/DRY AIR ADVECTION ARRIVES BY WEDNESDAY EVENING AND
CONTINUES THROUGH THURSDAY. BRISK NORTHWEST WINDS WILL GRADUALLY
DIMINISH AS THE GRADIENT RELAXES FOLLOWING THE RAPID DEPARTURE OF
THE LOW. SKIES WILL GENERALLY REMAIN ON THE CLOUDIER SIDE WITH A
NOISY FAST MID LEVEL FLOW KEEPING AT LEAST SOME MID AND HIGH LEVEL
CLOUDS STREAMING IN HERE. THE CU RULE DOES SUPPORT DIURNAL CU ON
THURSDAY. AN APPROACHING STRONG MID LEVEL SHORT WAVE WILL REALLY
THICKEN UP THE CLOUDS BY LATE THURSDAY NIGHT.
FRIDAY AND FRIDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
A STRONG SHORT WAVE WILL TRACK ACROSS WISCONSIN FRIDAY INTO
FRIDAY EVENING. THE ECMWF ACTUALLY CLOSES OFF A FEW H5 HEIGHT
CONTOURS AS IT PUSHES ACROSS THE GREAT LAKES. THE GFS AND THE
CANADIAN HAVE MORE OF AN OPEN TROF. AT THE SFC THE PATTERN
REMAINS BENIGN WITH MOSTLY HIGH PRESSURE IN PLACE. THE ECMWF TRIES
TO BRING AN INVERTED TROF UP ACROSS LAKE MICHIGAN/LOWER
MICHIGAN...BUT IT IS THE STRONGEST OF THE MODELS WITH THIS SYSTEM.
DESPITE THE QUIET LOWER LEVELS...THERE IS IMPRESSIVE MID LEVEL
FRONTOGENESIS AND ENOUGH MOISTURE TO SUPPORT SOME SHOWERS FRIDAY
INTO FRIDAY EVENING.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE IS HIGH.
HIGH PRESSURE AND VERY CHILLY AIR WILL BE IN PLACE THIS WEEKEND.
AT LEAST WE SHOULD SEE SOME SUNSHINE. LOOK FOR A SLIGHT MODERATION
IN TEMPS BETWEEN SATURDAY AND SUNDAY. LOWS BOTH SATURDAY AND
SUNDAY WILL BE DOWN IN THE 40S WITH SOME UPPER 30S POSSIBLE IN A
FEW SPOTS.
MONDAY...FORECAST CONFIDENCE IS MEDIUM.
THE FAST ZONAL MID LEVEL FLOW WILL BRING ANOTHER SHORTWAVE IN
HERE FOR MONDAY...POSSIBLY KICKING OFF A FEW SHOWERS. PRETTY MINOR
STUFF AT THIS POINT.
AVIATION/00Z TAFS/...LOW PRESSURE WILL CONTINUE TO STRENGTHEN AS IT
RIDES NORTHEAST INTO LATER TONIGHT INTO WEDNESDAY MORNING. VERY
HEAVY RAINFALL RATES WILL ALLOW FOR IFR CIGS/VSBYS AS RA/TSRA MOVE
ACROSS...WITH THE MAIN WINDOW BETWEEN 06Z-16Z...WEST TO EAST ACROSS
SRN WI. GUSTY SOUTH THEN SOUTHWEST WINDS WILL DEVELOP LATER THIS
EVENING AHEAD OF THE LOW AND THEN SHIFT NORTHWEST AND BECOME GUSTY
AFTER THE LOW MOVES EAST BY WEDNESDAY AFTERNOON. SOME POTENTIAL FOR
LLWS IN THE 10-14Z TIME FRAME DUE TO PROXIMITY OF STRONGER WINDS
ASSOCIATED WITH THE SOUTHERLY LOW LEVEL WIND MAX.
MARINE...WINDS/WAVES WILL REACH SMALL CRAFT ADVISORY
CONDITIONS LATE TONIGHT AND APPROACH GALE WARNING CRITERIA ON
WEDNESDAY AND WEDNESDAY EVENING AS AN UNUSUALLY STRONG EARLY SEASON
LOW INTENSIFIES OVER WISCONSIN WEDNESDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FLASH FLOOD WATCH FROM 1 AM CDT WEDNESDAY THROUGH WEDNESDAY
AFTERNOON FOR WIZ046-047-051-052-056>060-062>072.
LM...SMALL CRAFT ADVISORY FROM 4 AM WEDNESDAY TO NOON CDT THURSDAY
FOR LMZ643>646.
DENSE FOG ADVISORY UNTIL 7 AM CDT WEDNESDAY FOR LMZ643-644.
&&
$$
UPDATE...REM
TONIGHT/WEDNESDAY AND AVIATION/MARINE...COLLAR
WEDNESDAY NIGHT THROUGH TUESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
704 PM CDT TUE SEP 9 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 245 PM CDT TUE SEP 9 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG
COLD FRONT MOVING SOUTHEAST ACROSS NORTHERN MINNESOTA AND SOUTH
DAKOTA...WHILE LOW PRESSURE IS EMERGING INTO WESTERN KANSAS. AN
ISOLATED THUNDERSTORM DROPPED A QUARTER OF AN INCH OF RAIN OVER
WAUSAU EARLIER THIS MORNING WITHIN A MODEST MOISTURE AXIS BUT
DIMINISHED BY MIDDAY. OTHERWISE...NO OTHER CONVECTION HAS DEVELOPED
SO FAR TODAY. THUNDERSTORM ACTIVITY CONTINUES TO EXPAND OVER
NEBRASKA AND IOWA IN AN AREA OF MOISTURE CONVERGENCE AT 850MB. AS
LOW PRESSURE MOVES EAST AND THE LLJ MATURES THIS EVENING...THIS AREA
WILL DRAW ATTENTION FOR THE POTENTIAL OF SEVERE WEATHER AND HEAVY
RAIN DOWNSTREAM OVER CENTRAL AND NORTHEAST WISCONSIN LATER TONIGHT.
ANOTHER AREA OF RAIN CONTINUES TO DEVELOP OVER THE EASTERN DAKOTAS.
AS THESE SYSTEMS MOVE EAST...SEVERE WEATHER AND HEAVY RAIN POTENTIAL
ARE THE MAIN FORECAST CONCERNS.
TONIGHT...FOLLOWED THE ECMWF AND SREF FOR THE DETAILS OF THIS
FORECAST...WHICH IS PREFERRED BY HPC AND SUPPORTED BY THE ENSEMBLE
MEANS. THESE MODELS SHOW THAT THE STRONG COLD FRONT OVER THE
NORTHERN PLAINS WILL SAG SOUTH INTO NORTH-CENTRAL WISCONSIN THIS
EVENING AS LOW PRESSURE TRACKS NORTHEAST ACROSS THE CENTRAL PLAINS.
AHEAD OF THIS LOW...MID-LEVEL FLOW WILL BE BACKING WHILE INCREASING
AT THE SAME TIME...LEADING TO INCREASING ISENTROPIC ASCENT IN THE
PRESENCE OF MID-LEVEL LAPSE RATES BETWEEN 6-7 C/KM THROUGH THE
EVENING. WEAK SHORTWAVE ENERGY AND UPPER DIVERGENCE WILL ALSO BE
APPROACHING BY LATE IN THE EVENING. THIS ALL POINTS TO INCREASING
CHANCES OF SHOWERS AND THUNDERSTORMS FROM WEST TO EAST THROUGH THE
EVENING. PRECIP MAY BE MORE OF THE SCATTERED VARIETY DURING THE
EVENING...BUT THE MAIN SHOW LOOKS TO ARRIVE AFTER MIDNIGHT FROM THE
SOUTHWEST. AS THE LOW MOVES TOWARDS FAR NORTHEAST IOWA OR SOUTHWEST
WISCONSIN...THE NOSE OF THE LLJ WILL IMPINGE ON CENTRAL AND
NORTHEAST WISCONSIN. OUTSTANDING MOISTURE TRANSPORT WILL ADVECT IN
PWATS GREATER THAN 2 INCHES WHILE STRONG MID-LEVEL FGEN WILL BE
FOCUSED ON THE NOSE OF THE LLJ. ELEVATED INSTABILITY WILL PEAK
DURING THE EVENING HOURS...SO SOME POTENTIAL FOR SEVERE CONVECTION
WITH DAMAGING WIND GUSTS TO REACH CENTRAL WISCONSIN ALONG THE
LEADING EDGE OF ANY THUNDERSTORMS MOVING NORTHEAST OUT OF IOWA. BUT
INSTABILITY RAPIDLY WANES AFTER MIDNIGHT...LEAVING HEAVY RAINFALL AS
THE MAIN HAZARD. ALTHOUGH THERE REMAINS SOME UNCERTAINTY WITH THE
TRACK OF THE SURFACE LOW...THE HEAVIEST RAINFALL SHOULD FALL ON THE
NOSE OF THE LLJ WHICH IS PROJECTED TO PUSH ACROSS CENTRAL AND
NORTHEAST WISCONSIN OVERNIGHT INTO WEDNESDAY MORNING. 1.5 TO 2.5
INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS ARE POSSIBLE OVER CENTRAL
WISCONSIN BY MORNING.
WEDNESDAY...LOW PRESSURE WILL TRACK TOWARDS THE COAST LINE OF
EAST-CENTRAL OR NORTHEAST WISCONSIN BY 18Z WED. THE HEAVIEST OF
RAIN WILL BE ONGOING ON THE NOSE OF THE LLJ OVER NORTHEAST
WISCONSIN. LOOKING FOR THE SAME MAGNITUDE OF AMOUNTS IN THIS REGION
COMPARED TO CENTRAL WISCONSIN...1.5 TO 2.5 INCHES WITH LOCALLY
HIGHER AMOUNTS. THE HEAVY RAIN WILL PULL OUT WEDNESDAY AFTERNOON AS
NORTHWEST WINDS BEHIND THE SYSTEM DRAWS IN MUCH COLDER AIR INTO
NORTH-CENTRAL WISCONSIN. A WIDE RANGE OF HIGH TEMPERATURES WILL BE
PRESENT TOMORROW...RANGING FROM THE MIDDLE 50S NORTH TO THE LOWER
70S SOUTHEAST.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 245 PM CDT TUE SEP 9 2014
COOLER TEMPERATURE TRENDS AND PCPN CHANCES WILL BE THE FOCUS
DURING THIS PERIOD.
REMAINING SHOWERS FROM THE STRONG WEDNESDAY SYSTEM WILL DEPART TO
THE NORTHEAST BUT SMALL SHOWER CHANCES WILL LINGER INTO THURSDAY OVER
THE NORTH DUE TO CAA INSTABILITY OVER LAKE SUPERIOR. BLUSTERY
NORTH WINDS WILL BRING A FEEL OF FALL TO THE AREA.
HIGH PRESSURE WILL REMAIN SETTLED OVER THE NORTHERN PLAINS
THURSDAY NIGHT WITH SUBTLE CAA CONTINUING. SOME POTENTIAL OF FROST
FRIDAY MORNING OVER THE NORTH BUT WILL DEPEND ON DIMINISHING WINDS
AND CLOUDS. CLOUDS MAY ALREADY BE ON THE INCREASE WITH THE
APPROACH OF A DEEP MID LEVEL TROUGH OR CLOSED UPPER LOW
SYSTEM. THIS SYSTEM WILL BRING A CHANCE OF SHOWERS TO THE AREA
WHICH WILL LINGER INTO SATURDAY MORNING.
COOL HIGH PRESSURE WILL THEN BUILD INTO THE THE GREAT LAKES REGION
FOR THE WEEKEND TO PROVIDE MORE CHANCES OF FROST...AND POSSIBLE
HEADLINES. AGAIN WINDS MAY BE AN ISSUE SINCE THE CENTER OF THE
HIGH SLIDES INTO CENTRAL ILLINOIS SATURDAY NIGHT.
RETURN FLOW WILL BEGIN TO BRING MODERATING WARMER TEMPS INTO THE
AREA SUNDAY FOLLOWED WITH ANOTHER CHANCE OF SHOWERS WITH A
POSSIBLE FRONTAL SYSTEM FOR EARLY NEXT WEEK.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 701 PM CDT TUE SEP 9 2014
AS A STRONG COLD FRONT DROPS SOUTHWARD INTO NORTHERN
WISCONSIN TONIGHT...LOW PRESSURE WILL BE LIFTING NORTHEAST ACROSS
SOUTHWEST TO EAST-CENTRAL WISCONSIN WEDNESDAY MORNING. AHEAD OF
THIS FRONT AND SURFACE LOW...EXPECT CONDITIONS TO DETERIORATE
THROUGH THE NIGHT...STARTING OUT IN NORTH-CENTRAL AND CENTRAL
WISCONSIN THIS EVENING...AND THEN REACHING NORTHEAST WISCONSIN
OVERNIGHT. BEFORE RAIN MOVES IN...HOWEVER...LOCAL IFR CIGS AND
VSBYS IN FOG ALONG LAKE MICHIGAN. A LARGE AREA OF SHOWERS AND
THUNDERSTORMS SHOULD SURGE NORTHEAST AHEAD OF LOW OVERNIGHT INTO
EARLY WEDNESDAY MORNING WHICH COULD PRODUCE STRONG GUSTY
WINDS...IN ADDITION WIDESPREAD HEAVY RAIN. LIFR CONDITIONS ARE
LIKELY AT RHI AND AUW/CWA AND POSSIBLY GRB/ATW/MTW OVERNIGHT
THROUGH WEDNESDAY MORNING. IMPROVING CONDITIONS SHOULD OCCUR
WEDNESDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 245 PM CDT TUE SEP 9 2014
WHILE A SOAKING RAIN OF 1.00 TO 1.50 IS EXPECTED FOR
ALL LOCATIONS TONIGHT INTO WEDNESDAY...VERY CHALLENGING FORECAST
WITH DETERMINING THE AXIS OF HEAVIER RAINFALL DUE TO THE TRACK OF
THE SURFACE LOW. ECMWF TRACKS PLACES THE MAX OF 2-3 INCHES OVER
CENTRAL TO NORTHEAST WISCONSIN...NAM MUCH FURTHER NORTH WHILE THE
GEM AND MAV FOCUS OVER THE SOUTH HALF OF THE STATE INCLUDING
BRUSHING PARTS OF EAST CENTRAL WISCONSIN. TO COMPLICATE THE
SITUATION...RADAR TRENDS OVER THE CENTRAL PLAINS SHOWING SOME SPLIT
IN THE RAIN REGIONS. THE SOUTHERN REGION OF HEAVY RAINFALL OVER
SOUTHWEST IOWA IS THE PRIMARY REGION OF CONCERN AND WILL BE THE
FOCUS OF LATER NIGHT HEADLINES. REGARDLESS...THE FLOOD WATCH WILL
CONTINUE FOR THE ENTIRE AREA STARTING LATE THIS EVENING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH WEDNESDAY EVENING FOR WIZ005-010>013-018>022-
030-031-035>040-045-048>050-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......JKL
HYDROLOGY......TDH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 251 PM CDT MON SEP 8 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SHORTWAVE
TROUGH MOVING EAST NORTHEAST OVER NORTHWEST WISCONSIN EARLY THIS
AFTERNOON. IN THE DEFORMATION ZONE OF THIS SHORTWAVE...AN AREA OF
LIGHT RAIN IS MOVING NORTHEAST FROM AMERY TO PHILLIPS. DRY AIR HAS
IMPEDED ITS PROGRESS SO FAR TODAY...BUT SHOULD SEE ENOUGH FORCING
FOR LIGHT RAIN TO MAKE ITS WAY ACROSS NORTH-CENTRAL WISCONSIN THIS
AFTERNOON DESPITE HIGH CLOUD BASES. MOSTLY CLEAR CONDITIONS EXIST
BEHIND THIS SHORTWAVE OVER THE DAKOTAS. THEN THERE IS A STRONG COLD
FRONT MOVING SLOWLY SOUTHEAST ACROSS SOUTH-CENTRAL CANADA. TIMING
OF PRECIP CHANCES TONIGHT AND THE POTENTIAL FOR THUNDERSTORMS ON
TUESDAY ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE SHORTWAVE WILL MOVE ACROSS THE FORECAST AREA DURING
THE EVENING. LIGHT RAIN IN THE DEFORMATION ZONE WILL MOVE NORTHEAST
ACROSS N-C WISCONSIN EARLY THIS EVENING AND INTO THE UPPER PENINSULA
BY MID-EVENING. DESPITE DECENT MID-LEVEL LAPSE RATES...THE
SHORTWAVE WILL OUTRUN THE MOISTURE AXIS BELOW 700MB...AND AM
COUNTING ON THE DRY AIR BELOW THIS LEVEL TO KEEP DRY CONDITIONS IN
PLACE ELSEWHERE. BEHIND THE SHORTWAVE...MID-LEVELS DRY OUT AS
SUBSIDENCE ARRIVES...BUT MODELS ALSO PROJECT AN INCREASE OF LOW
LEVEL MOISTURE FROM THE CENTRAL PLAINS. BASED ON SATELLITE
IMAGERY...THIS LOOKS OVERDONE AND PROGGED SOUNDINGS CONTINUE TO LOOK
DRY ABOVE 850MB OVERNIGHT. WILL BACK OFF ON THE CLOUD COVER AS WELL
AS PRECIP CHANCES. LOWS MAINLY IN THE 50S.
TUESDAY...AS LOW PRESSURE EMERGES INTO THE CENTRAL PLAINS...A
SHALLOW COLD FRONT WILL DROP SOUTHEAST INTO NORTH-CENTRAL WISCONSIN
AND THE WESTERN UPPER PENINSULA DURING THE AFTERNOON. AHEAD OF THE
FRONT...WEAK THETAE ADVECTION WILL BE ONGOING DURING THE
MORNING...BUT PROGGED SOUNDINGS CONTINUE TO LOOK DRY ABOVE 850MB.
WILL MOST LIKELY NEED TO WAIT FOR DAYTIME DESTABILIZATION TO TAKE
PLACE FOR THE CHANCE OF SHOWERS AND THUNDERSTORMS TO
OCCUR...STARTING EARLY AFTERNOON. BY MID-AFTERNOON...LOW LEVEL
MOISTURE AXIS AND FORCING ALONG THE FRONT SHOULD IMPROVE
THUNDERSTORM CHANCES. ML CAPES AHEAD OF THE BOUNDARY REACH UP TO
1200 J/KG WITH 0-6KM BULK SHEARS OF 20-25 KTS. CANNOT FIND MUCH OF
A CAP BY 21Z...SO THINKING ISOLATED TO LOW END SCT SHOWERS AND
STORMS WILL BE POSSIBLE. COULD SEE AN ISOLATED PULSE SEVERE THREAT
DEVELOP IF INSTABILITY REACHES ITS POTENTIAL. HIGHS IN THE MIDDLE
TO UPPER 70S.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 251 PM CDT MON SEP 8 2014
PRIMARY FOCUS DURING THIS PERIOD IS THE STRONG STORM SYSTEM TO
IMPACT THE REGION THROUGH MID WEEK. STRONG CONVERGENCE WITH A
DEEPENING SURFACE LOW AND H850 LOW TRACKING OVER THE STATE LATE
TUESDAY INTO WEDNESDAY COMBINED WITH PWATS CLIMBING TO A VERY
MOIST 1.50 TO 2.00 INCHES WILL LIKELY PRODUCE A SWATH OF HEAVY
RAIN STARTING TUESDAY EVENING AND CONTINUE INTO WEDNESDAY
AFTERNOON BEFORE GRADUALLY DIMINISHING FROM SOUTHWEST TO NORTHEAST.
JUST ABOUT ALL MAIN STEM RIVERS ARE RUNNING HIGH AND ANTICIPATED
AMOUNTS WOULD LIKELY RAISE LEVELS TO FLOOD STAGE. THE POTENTIAL OF
A WIDESPREAD 1.50 TO AS HIGH AS 3.00 INCHES CONTINUES TO INCREASE.
LOCALLY HIGHER RAINFALL AMOUNTS DUE TO STORMS COULD INCREASE THE
IMPACTS OF THE FLOODING ALONG THE RIVERS AS WELL AS FOR URBAN
AREAS. EVEN THOUGH THERE IS A FLASH FLOOD POTENTIAL...WILL GO WITH
THE FLOOD WATCH VARIETY FOR NOW DUE TO THE HIGHER POTENTIAL OF THE
RIVER FLOODING.
MUCH COOLER TEMPERATURES WITH A SHOT OF BLUSTERY FALL WINDS WILL
POUR INTO THE AREA FOR THE REST OF THE WEEK. MINOR PRECIP CHANCES
WILL CONTINUE FOR THE REMAINDER OF THE WEEK AS A TROUGH OF LOW
PRESSURE SETTLES OVER THE AREA.
COOLER DRIER AIR REMAINS OVER THE WEEKEND WITH THE LIKELY CHANCE
OF THE FIRST FROST OR FREEZE HEADLINE OF THE SEASON FOR THE
NORTHERN PORTION OF THE FORECAST AREA.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1208 PM CDT MON SEP 8 2014
A WEAK DISTURBANCE WILL MOVE ACROSS THE REGION THIS
AFTERNOON AND EVENING AND GENERATE LIGHT SHOWERS AND
SPRINKLES...MAINLY OVER NORTHWEST WISCONSIN. PLENTY OF DRY AIR
CURRENTLY RESIDES ACROSS THE REGION...BUT A FEW SHOWERS COULD
SURVIVE THE TRIP INTO NORTH-CENTRAL WISCONSIN THIS AFTERNOON. CONFIDENCE IS
TOO LOW TO INCLUDE IN THE RHI TAF...AND FLIGHT CATEGORIES SHOULD
REMAIN IN THE VFR RANGE REGARDLESS. ONCE THIS DISTURBANCE EXITS
LATE IN THE EVENING...MODELS DEPICT LOW LEVEL MOISTURE SURGING
NORTHEAST THAT COULD CREATE BKN MVFR CLOUDS LATE TONIGHT OVER
NORTH-CENTRAL WISCONSIN. THE MODELS APPEAR TO BE OVERDOING THE
MOISTURE...HOWEVER...AND CONFIDENCE IS LOW AGAIN THAT WE WILL SEE
MVFR CIGS DEVELOP. LEFT A SCT MENTION TO INDICATE THAT THERE MAY BE
LOW CIGS AROUND LATE TONIGHT. IF CLOUDS DO NOT FORM...VFR
CONDITIONS WILL PREVAIL FOR THE DURATION OF THE FORECAST.
&&
.MARINE...
ISSUED AT 251 PM CDT MON SEP 8 2014
GUSTY SOUTHEAST/SOUTH WINDS MAY DEVELOP WEDNESDAY ACROSS PORTIONS
OF THE MARINE AREA DEPENDING ON TRACK OF THE LOW PRESSURE SYSTEM.
ONCE THE SYSTEM MOVES EAST OF THE AREA... GALE FORCE GUSTS ARE
POSSIBLE WEDNESDAY NIGHT INTO THURSDAY. WINDS AND WAVES WILL
GRADUALLY SUBSIDE THURSDAY AFTERNOON AND EVENING.
&&
.HYDROLOGY...
ISSUED AT 251 PM CDT MON SEP 8 2014
WILL ISSUE A FLOOD WATCH FOR TUESDAY NIGHT INTO WEDNESDAY IN
ANTICIPATION FOR A WIDESPREAD 1.50 TO NEARLY 3 INCH AMOUNTS IN A
24 HOUR PERIOD. THE WATCH WILL ALSO INCLUDE THE AREA WHICH
RECEIVED HEAVY RAIN LAST WEEK AND WHERE RIVER LEVELS AND STREAMS
REMAIN QUITE HIGH. SHOULD NOTE THAT EVEN THOUGH THE HEAVY RAIN
WILL NOT REACH THE AREA UNTIL LATER TUESDAY EVENING...MINOR
FLOODING MAY ACTUALLY START TUESDAY DUE TO HYDRO OPERATIONS
RELEASING WATER EARLY IN ADVANCE OF THE HEAVY RAIN. EVEN THOUGH
THE HEAVY RAINFALL WILL BE ENDING WEDNESDAY AFTERNOON...RUNOFF
EFFECTS INTO AREA RIVES WILL BE ON THE INCREASE WEDNESDAY EVENING
INTO THURSDAY AND IF THE SCENARIO PANS OUT...WARNINGS WILL
PROBABLY BE GOING INTO AFFECT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR
WIZ005-010>013-018>022-030-031-035>040-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......MPC
MARINE.........TDH
HYDROLOGY......TDH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
401 AM EDT WED SEP 10 2014
.SYNOPSIS...
WEAK LOW PRESSURE PASSING SE OF NEW ENGLAND MAY BRING A FEW
SHOWERS TO THE ISLANDS TODAY...OTHERWISE DRY WEATHER WILL PREVAIL
TODAY. A COLD FRONT WILL SWING ACROSS THE REGION LATE THURSDAY
AND EARLY FRIDAY...THEN STALL JUST OFFSHORE. A DISTURBANCE MOVING
ALONG THIS FRONT SATURDAY MAY COME CLOSE ENOUGH TO RESULT IN
SHOWERS. HIGH PRESSURE RETURNS WITH DRY AND COOLER WEATHER SUNDAY
INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
320 AM UPDATE...
MAIN BATCH OF SHOWERS REMAINS SE OF NANTUCKET AND EXPECT MOST OF
IT TO REMAIN OFFSHORE TODAY. MODELS SEEM TO BE STRUGGLING WITH HOW
CLOSE THESE SHOWERS GET TO SE NEW ENGLAND...BUT HRRR LOOKS
REASONABLE IN GRAZING NANTUCKET THROUGH MID MORNING. DRY AIR AT
MID LEVELS PER 00Z CHATHAM SOUNDING WILL PREVENT MUCH OF THIS FROM
REACHING GROUND...IN FACT WE MAY JUST END UP WITH FEW SPRINKLES ON
ISLANDS AND OUTER CAPE.
LOW CLOUDS AND PATCHY FOG WILL PREVAIL ELSEWHERE THROUGH DAYBREAK
DUE TO LIGHT ONSHORE FLOW...BUT WILL BREAK AFTER SUNRISE AND GIVE
WAY TO PARTLY TO MOSTLY SUNNY SKIES.
CONTINUED ONSHORE FLOW WILL KEEP HIGHS NEAR AVERAGE FOR MOST
PART...MAINLY IN 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
EXPECT A RETURN OF LOW CLOUDS/FOG TONIGHT WHICH SHOULD BE MORE
WIDESPREAD AS LOWER LEVELS MOISTEN WITH E/SE FLOW. MAY SEE AREAS
OF DENSE FOG ALONG IMMEDIATE COAST. OTHERWISE SURFACE RIDGE KEEPS
US DRY ASIDE FROM SPOTTY DRIZZLE.
COLD FRONT APPROACHES NEW ENGLAND THU BUT SHOULD REMAIN TO OUR W.
FLOW TURNS MORE S/SW IN ADVANCE OF FRONT WHICH WILL HELP SCOUR OUT
LOW CLOUDS/FOG IN THE MORNING...EXCEPT AROUND S COAST...CAPE COD
AND ISLANDS WHERE IT MAY PERSIST INTO AFTERNOON.
INSTABILITY LOOKS MARGINAL AND MID LEVEL LAPSE RATES ARE WEAK...
BUT ENOUGH TO INCLUDE MENTION OF THUNDER AHEAD OF FRONT. BETTER
CHANCES ACROSS INTERIOR WHERE S FLOW OFF OCEAN IS LESS OF
STABILIZING FACTOR. MODELS CONTINUE TO SHOW PLENTY OF MOISTURE
AVAILABLE WITH PRECIPITABLE WATER VALUES NEAR 2 INCHES /+2 TO +3
STANDARD DEVIATION/...SO LOCALLY HEAVY RAINFALL CAN BE EXPECTED.
HIGHS SHOULD REACH 70S AND LOWER 80S...AND IT WILL FEEL MORE
SUMMERLIKE AS DEWPOINTS CLIMB WELL INTO 60S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS/ISOLATED T-STORMS THU PM INTO EARLY FRI
* SLIGHT CHANGE FOR SHOWERS SAT PM/SUN
* A TASTE OF AUTUMN TEMPERATURES NEXT WEEK
OVERVIEW...
LATEST MODEL AND ENSEMBLE GUIDANCE OVERALL SEEMS TO OFFER FAIRLY
REASONABLE LARGER SCALE PATTERN EVOLUTION CONTINUITY. AN AMPLIFYING
ERN PAC TROUGH AND WEST COAST RIDGE DRIFTING INTO WRN NOAM WILL
SUPPORT MEAN MID-UPPER LEVEL TROUGHING OVER THE ERN HALF OF NOAM.
THIS PATTERN...MORE TYPICAL OF THE COLD SEASON THAN LATE SUMMER OR
EARLY FALL...SHOULD YIELD BELOW TO MUCH BELOW NORMAL TEMPS OVER MOST
OF THE ERN 2/3 OF THE CONUS. HOWEVER...DETERMINISTIC MODEL RUNS
FEATURE TOO MUCH INCONSISTENCY.
SEVERAL RIPPLES WILL MOVE THROUGH THE FLOW THROUGH THE PERIOD WITH
THE FIRST ONE BRINGING A COLD FRONT ON THURSDAY NIGHT/FRI MORNING.
ANOTHER SHORTWAVE WILL PASS SAT/SAT NIGHT. THIS ONE CAUSES MORE
UNCERTAINTY AS THE GFS IS HAVING CONVECTIVE FEEDBACK AND IS CREATING
A 1-2 INCH BULLS-EYE OVER THE REGION...IN RETROSPECT THE EC IS
PRODUCING VERY LIGHT QPF. LASTLY ANOTHER WAVE WILL MOVE TROUGH THE
FLOW MONDAY NIGHT/TUESDAY.
OVERALL HAVE MODERATE CONFIDENCE IN THE FORECAST AS THERE IS TO MUCH
SPREAD BETWEEN THE DETERMINISTIC AND ENSEMBLE FORECASTS ESP IN
SPECIFIC DETAILS IN THE FORECAST.
DETAILS...
THURSDAY NIGHT INTO FRIDAY...
THE FOCUS IS ON A STRONG COLD FRONT THAT WILL PUSH ACROSS THE REGION
THURSDAY NIGHT INTO FRIDAY MORNING. BOTH DETERMINISTIC AND ENSEMBLES
KEEP THE INSTABILITY VALUES VERY LOW BUT BECAUSE OF THE STRENGTH OF
THIS FRONT HAVE KEPT ISO MENTIONING OF THUNDER FOR THURSDAY. TIMED
THE THUNDER POTENTIAL WITH THE BETTER K-VALUES AND LI. PRECIPITABLE
WATERS INCREASE CONSIDERABLY...CLOSE TO 2-3 INCHES...WITH A
STRENGTHENING SOUTHERLY FLOW. SOME OF THESE STORMS MAY PRODUCE HEAVY
RAIN...WITH AN ISOLD FLASH FLOOD THREAT PRIMARILY IN URBANIZED
AREAS. THEREFORE ALSO INCLUDED HEAVY RAIN WORDING FOR ANY
THUNDERSTORM POTENTIAL.
HIGH PRESSURE WILL QUICKLY SWING INTO THE AREA BY FRIDAY ALLOWING
FOR THE DAY TO DRY OUT AND TEMPS TO REACH NEAR NORMAL.
SATURDAY TO SATURDAY NIGHT...
HIGH PRESSURE WILL BEGIN TO LIFT NORTHWARD ALLOWING FOR EASTERLY FLOW
ON SATURDAY. BY THE LATE AFTERNOON/EVENING HOURS A COLD FRONT WILL
PASS THROUGH REGION BRINGING ANOTHER CHANCE OF THUNDERSTORMS. AS
MENTIONED BEFORE...THERE IS SIGNIFICANT DIFFERENCE BETWEEN THE
DETERMINISTIC GUIDANCE WITH THE GFS PRODUCING A 1-2 INCH BULLS-EYE.
WHILE THE EC IS DEVELOPING LIGHT QPF. APPEARS THE GFS IS RECEIVING
CONVECTIVE FEEDBACK BUT BECAUSE BOTH ARE TRENDING TO MOVE
PRECIP...HAVE INCREASED THE POTENTIAL TO CHANCE POP.
SUNDAY INTO NEXT WEEKEND...
A MODIFIED CANADIAN HIGH WILL THEN BUILD IN THROUGH EARLY NEXT WEEK
BEFORE ANOTHER FRONTAL SYSTEM POSSIBLY IMPACTS THE AREA AROUND
TUES OF NEXT WEEK.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE THROUGH THU.
AREAS OF MVFR/IFR CIGS/VSBYS THROUGH 12Z WITH BRIEF SHOWER/
SPRINKLE POSSIBLE NEAR NANTUCKET AND VINEYARD. CONDITIONS IMPROVE
TO VFR AFTER 12Z FROM W TO E BUT MVFR CIGS MAY LINGER INTO EARLY
AFTERNOON NEAR S COAST...CAPE COD AND ISLANDS.
CIGS/VSBYS LOWER AGAIN TONIGHT DUE TO PERSISTENT ONSHORE FLOW...
THIS TIME TO IFR/LIFR ACROSS MUCH OF REGION. CONDITIONS SLOWLY
IMPROVE TO VFR AGAIN THU MORNING...LAST ACROSS CAPE COD AND
ISLANDS THU AFTERNOON...BUT SCATTERED SHOWERS/THUNDERSTORMS
POSSIBLE ACROSS INTERIOR AFTER 18Z. MAY REACH BOS/PVD BY 22Z.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...A PERIOD OF MVFR/IFR CONDITIONS POSSIBLE EARLY FRIDAY IN
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS AS A COLD FRONT SWEEPS
THROUGH. OTHERWISE...VFR CONDITIONS EXPECTED FOR A GOOD PORTION
OF THIS PERIOD.
SATURDAY...LOW CONFIDENCE. MAINLY VFR. ONSHORE FLOW COULD ALSO
RESULT IN IFR STRATUS AND FOG ACROSS PORTIONS OF THE EAST
COAST...PARTICULARLY CAPE COD AND THE ISLANDS.
SUNDAY...MODERATE CONFIDENCE. MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THU.
SCA REMAINS POSTED FOR OUTER WATERS MAINLY DUE TO 5-6 FT SEAS
TODAY THROUGH THU.
E/NE WINDS GRADUALLY SUBSIDE TODAY AS LOW PRESSURE PASSES WELL SE
OF NEW ENGLAND...THEN S/SW WINDS DEVELOP THU AS COLD FRONT
APPROACHES FROM GREAT LAKES. MAIN CONCERN IS PATCHY DENSE FOG
TONIGHT INTO THU...ESPECIALLY ON S COASTAL WATERS.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...MODERATE CONFIDENCE. A ROUND OF SCATTERED SHOWERS AND
PERHAPS ISOLATED THUNDERSTORMS ARE EXPECTED EARLY FRIDAY MORNING
AS A COLD FRONT PASSES THROUGH. WINDS WILL MAY REACH ABOVE 25 KT
BEHIND THIS FRONT ALLOWING FOR SEAS TO APPROACH 5 FT AT TIMES
ACROSS THE OUTER COASTAL WATERS. SMALL CRAFT ADVISORIES MAY BE
NEEDED.
SATURDAY...LOW CONFIDENCE. TIGHTENING PRESSURE GRADIENT AND
APPROACHING COLD FRONT WILL HELP KEEP SEAS AND WINDS UP ON
SATURDAY. SMALL CRAFT ADV MAY BE NEEDED.
SUNDAY...STRONG COLD FRONT WILL PASS OVER THE WATERS IN THE
MORNING. COLD AIR ALOFT WILL INCREASE SEAS AND WIND GUSTS ON
SUNDAY LEADING TO THE POTENTIAL OF A SMALL CRAFT ADV.
&&
.TIDES/COASTAL FLOODING...
LAST HIGH TIDE JUST BEFORE MIDNIGHT PRODUCED 0.2 FT SURGE ALONG E
MA COAST. SUBSEQUENT HIGH TIDES TODAY INTO THU ARE A BIT LOWER AND
SURGE WILL BE MINIMAL...THEREFORE NO IMPACT IS EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...DUNTEN/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...DUNTEN
AVIATION...DUNTEN/JWD
MARINE...DUNTEN/JWD
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
321 AM EDT WED SEP 10 2014
.SYNOPSIS...
WEAK LOW PRESSURE PASSING SE OF NEW ENGLAND MAY BRING A FEW
SHOWERS TO THE ISLANDS TODAY...OTHERWISE DRY WEATHER WILL PREVAIL
TODAY. A COLD FRONT WILL SWING ACROSS THE REGION LATE THURSDAY
AND EARLY FRIDAY...THEN STALL JUST OFFSHORE. A DISTURBANCE MOVING
ALONG THIS FRONT SATURDAY MAY COME CLOSE ENOUGH TO RESULT IN
SHOWERS. HIGH PRESSURE RETURNS WITH DRY AND COOLER WEATHER SUNDAY
INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
320 AM UPDATE...
MAIN BATCH OF SHOWERS REMAINS SE OF NANTUCKET AND EXPECT MOST OF
IT TO REMAIN OFFSHORE TODAY. MODELS SEEM TO BE STRUGGLING WITH HOW
CLOSE THESE SHOWERS GET TO SE NEW ENGLAND...BUT HRRR LOOKS
REASONABLE IN GRAZING NANTUCKET THROUGH MID MORNING. DRY AIR AT
MID LEVELS PER 00Z CHATHAM SOUNDING WILL PREVENT MUCH OF THIS FROM
REACHING GROUND...IN FACT WE MAY JUST END UP WITH FEW SPRINKLES ON
ISLANDS AND OUTER CAPE.
LOW CLOUDS AND PATCHY FOG WILL PREVAIL ELSEWHERE THROUGH DAYBREAK
DUE TO LIGHT ONSHORE FLOW...BUT WILL BREAK AFTER SUNRISE AND GIVE
WAY TO PARTLY TO MOSTLY SUNNY SKIES.
CONTINUED ONSHORE FLOW WILL KEEP HIGHS NEAR AVERAGE FOR MOST
PART...MAINLY IN 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
EXPECT A RETURN OF LOW CLOUDS/FOG TONIGHT WHICH SHOULD BE MORE
WIDESPREAD AS LOWER LEVELS MOISTEN WITH E/SE FLOW. MAY SEE AREAS
OF DENSE FOG ALONG IMMEDIATE COAST. OTHERWISE SURFACE RIDGE KEEPS
US DRY ASIDE FROM SPOTTY DRIZZLE.
COLD FRONT APPROACHES NEW ENGLAND THU BUT SHOULD REMAIN TO OUR W.
FLOW TURNS MORE S/SW IN ADVANCE OF FRONT WHICH WILL HELP SCOUR OUT
LOW CLOUDS/FOG IN THE MORNING...EXCEPT AROUND S COAST...CAPE COD
AND ISLANDS WHERE IT MAY PERSIST INTO AFTERNOON.
INSTABILITY LOOKS MARGINAL AND MID LEVEL LAPSE RATES ARE WEAK...
BUT ENOUGH TO INCLUDE MENTION OF THUNDER AHEAD OF FRONT. BETTER
CHANCES ACROSS INTERIOR WHERE S FLOW OFF OCEAN IS LESS OF
STABILIZING FACTOR. MODELS CONTINUE TO SHOW PLENTY OF MOISTURE
AVAILABLE WITH PRECIPITABLE WATER VALUES NEAR 2 INCHES /+2 TO +3
STANDARD DEVIATION/...SO LOCALLY HEAVY RAINFALL CAN BE EXPECTED.
HIGHS SHOULD REACH 70S AND LOWER 80S...AND IT WILL FEEL MORE
SUMMERLIKE AS DEWPOINTS CLIMB WELL INTO 60S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS/ISOLATED T-STORMS THU PM INTO EARLY FRI
* SLIGHT CHANGE FOR SHOWERS SAT PM/SUN
* A TASTE OF AUTUMN TEMPERATURES NEXT WEEK
OVERVIEW...
BUILDING UPPER RIDGE OVER THE NE PACIFIC AND WESTERN CANADA...AS
WELL AS MORE MODEST RIDGING OVER THE MARITIMES...WILL SUPPORT
DEEP TROUGHING OVER THE CENTRAL CONUS LATE THIS WEEK. THIS DEEP
TROUGH WILL PUSH A FRONT THROUGH OUR REGION BY LATE THU INTO FRI.
OVERALL THE LONGWAVE PREDICTABILITY REMAINS BETTER THAN AVERAGE
DESPITE THIS AMPLIFIED PATTERN. HOWEVER...DETERMINISTIC MODELS
STILL FEATURE TOO MUCH INCONSISTENCY FROM RUN TO RUN TO BE CERTAIN
OF THE DETAILS.
THOUGH THE INITIAL TROUGH LIFTS THROUGH THE GREAT LAKES AND
NORTHEAST INTO SOUTHEAST CANADA THIS WEEKEND...ENSEMBLES STILL
SUPPORT THE POSSIBILITY OF A MORE PERSISTENT LONGWAVE RIDGE/TROUGH
PATTERN....WITH SOUTHERN NEW ENGLAND CONTENDING MORE WITH A MID
LEVEL TROUGH. THE MAIN QUESTION REMAINS HOW WAVY AND CLOSE TO THE
COAST A COLD FRONT WILL REMAIN FRIDAY INTO SATURDAY. THIS WILL
ULTIMATELY DETERMINE THE AMOUNT/LOCATION OF ADDITIONAL/OVERRUNNING
PRECIPITATION. ENSEMBLE MEANS SUGGEST THE MAIN AXIS TO REMAIN JUST
OFFSHORE...BUT A CLOSER POSITION IN SOME OF THE INDIVIDUAL MEMBERS
SEEMS MORE CONSISTENT WITH SUCH AN AMPLIFIED PATTERN ALOFT. CONTINUE
TO BE ON THE OPTIMISTIC SIDE AND KEPT A PORTION OF THIS WEEKEND DRY
FOR NOW...MAINLY SUNDAY.
OVERALL HAVE MODERATE CONFIDENCE IN THE FORECAST AS THERE IS TOO
MUCH SPREAD BETWEEN THE DETERMINISTIC AND ENSEMBLE FORECASTS.
DETAILS...
THURSDAY INTO FRIDAY...
FOCUS IS ON A STRONG COLD FRONT THAT WILL PUSH ACROSS THE REGION
SOMETIME THURSDAY INTO FRIDAY. BOTH DETERMINISTIC AND ENSEMBLES KEEP
INSTABILITY VERY LOW. THERE IS DECENT SHEAR IN THE LOWER LEVELS
THOUGH. BECAUSE OF THE STRENGTH OF THIS FRONT AND THE SHEAR...KEPT A
MENTION OF ISOLATED TO SCATTERED THUNDERSTORMS IN THE FORECAST.
THERE COULD BE SOME HEAVY RAIN WITH THIS FRONT...BUT THE BEST
DYNAMICS AND CONDITIONS WILL BE TO THE WEST OF OUR REGION. THIS
FRONT WILL MAINLY PUSH THROUGH OVERNIGHT THURSDAY...THEN MOVE
FARTHER OFFSHORE FRIDAY MORNING. ALTHOUGH THERE IS STILL SOME
UNCERTAINTY ON TIMING AND HOW FAR OFFSHORE THIS FRONT WILL GO.
THIS WEEKEND...
ONCE AGAIN THIS FORECAST IS DEPENDENT ON HOW FAR OFFSHORE THE FRONT
WILL GET TOO. 09/12Z GUIDANCE KEEPS THE FRONT FAR ENOUGH
OFFSHORE...ALLOWING FOR A PORTION OF THIS WEEKEND TO BE DRY.
HOWEVER MOST OF THE 09/12Z GUIDANCE ALSO SWINGS A WEAK COLD FRONT
THROUGH THE GREAT LAKES INTO SOUTHERN NEW ENGLAND LATE SATURDAY
INTO SATURDAY NIGHT. THIS COULD POTENTIALLY PRODUCE SOME LIGHT
RAINFALL DURING THIS TIME. ONE THING TO WATCH IS THE CONTINUOUS
EASTERLY FLOW OFF THE WATERS. THIS MAY KEEP FOG/LOW CLOUDS ACROSS
THE EASTERN HALF OF THE REGION. THIS FORECAST IS STILL SEVERAL
DAYS OUT...SO WILL CONTINUE TO FINE TUNE IT AS THIS WEEK
PROGRESSES.
EARLY NEXT WEEK...
HIGH PRESSURE ARRIVES WITH A FALL-LIKE AIRMASS. 09/12Z GFS IS MUCH
MORE AGGRESSIVE THAN THE ECMWF IN SWINGING A MID LEVEL SHORTWAVE
THROUGH OUR REGION SOMETIME MONDAY INTO TUESDAY. BASED ON THE
PATTERN THOUGH...AM THINKING MOSTLY DRY WEATHER WITH JUST AN
INCREASE IN CLOUDS AT THIS TIME.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE THROUGH THU.
AREAS OF MVFR/IFR CIGS/VSBYS THROUGH 12Z WITH BRIEF SHOWER/
SPRINKLE POSSIBLE NEAR NANTUCKET AND VINEYARD. CONDITIONS IMPROVE
TO VFR AFTER 12Z FROM W TO E BUT MVFR CIGS MAY LINGER INTO EARLY
AFTERNOON NEAR S COAST...CAPE COD AND ISLANDS.
CIGS/VSBYS LOWER AGAIN TONIGHT DUE TO PERSISTENT ONSHORE FLOW...
THIS TIME TO IFR/LIFR ACROSS MUCH OF REGION. CONDITIONS SLOWLY
IMPROVE TO VFR AGAIN THU MORNING...LAST ACROSS CAPE COD AND
ISLANDS THU AFTERNOON...BUT SCATTERED SHOWERS/THUNDERSTORMS
POSSIBLE ACROSS INTERIOR AFTER 18Z. MAY REACH BOS/PVD BY 22Z.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...A PERIOD OF MVFR/IFR CONDITIONS POSSIBLE EARLY FRIDAY IN
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS AS A COLD FRONT SWEEPS
THROUGH. THERE MAY ALSO BE SOME LOWER CLOUDS AND FOG PATCHES AT
TIMES. OTHERWISE...VFR CONDITIONS EXPECTED FOR A GOOD PORTION OF
THIS PERIOD.
SATURDAY...LOW CONFIDENCE. MAINLY VFR. ONSHORE FLOW COULD ALSO
RESULT IN IFR STRATUS AND FOG ACROSS PORTIONS OF THE EAST
COAST...PARTICULARLY CAPE COD AND THE ISLANDS.
SUNDAY...MODERATE CONFIDENCE. MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THU.
SCA REMAINS POSTED FOR OUTER WATERS MAINLY DUE TO 5-6 FT SEAS
TODAY THROUGH THU.
E/NE WINDS GRADUALLY SUBSIDE TODAY AS LOW PRESSURE PASSES WELL SE
OF NEW ENGLAND...THEN S/SW WINDS DEVELOP THU AS COLD FRONT
APPROACHES FROM GREAT LAKES. MAIN CONCERN IS PATCHY DENSE FOG
TONIGHT INTO THU...ESPECIALLY ON S COASTAL WATERS.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...MODERATE CONFIDENCE. WINDS WILL MAY REACH ABOVE 25 KT
BEHIND COLD FRONT. A ROUND OF SCATTERED SHOWERS AND PERHAPS
ISOLATED THUNDERSTORMS ARE EXPECTED THURSDAY NIGHT INTO EARLY
FRIDAY. SEAS COULD APPROACH 5 FT AT TIMES ACROSS THE OUTER COASTAL
WATERS. SMALL CRAFT ADVISORIES MAY BE NEEDED.
SATURDAY...LOW CONFIDENCE. SEAS SHOULD SUBSIDE BELOW 5 FT AND
EASTERLY WINDS SHOULD DIMINISH BELOW 20 KTS.
SUNDAY...RELATIVELY TRANQUIL WINDS AND SEAS EXPECTED.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY AND FRIDAY...MODERATE CONFIDENCE. EASTERLY FLOW SWITCHES TO
THE SOUTHWEST AHEAD OF AN APPROACHING COLD FRONT. WINDS WILL MAY
REACH ABOVE 25 KT ON THE BACKSIDE OF THIS FRONT. A ROUND OF
SCATTERED SHOWERS AND PERHAPS ISOLATED THUNDERSTORMS ARE EXPECTED
LATE THURSDAY INTO EARLY FRIDAY. SEAS COULD APPROACH 5 FT AT TIMES
ACROSS THE OUTER COASTAL WATERS. SMALL CRAFT ADVISORIES MAY BE
NEEDED.
SATURDAY...LOW CONFIDENCE. SEAS SHOULD SUBSIDE BELOW 5 FT AND
EASTERLY WINDS SHOULD DIMINISH BELOW 20 KTS.
SUNDAY...RELATIVELY TRANQUIL WINDS AND SEAS EXPECTED.
&&
.TIDES/COASTAL FLOODING...
LAST HIGH TIDE JUST BEFORE MIDNIGHT PRODUCED 0.2 FT SURGE ALONG E
MA COAST. SUBSEQUENT HIGH TIDES TODAY INTO THU ARE A BIT LOWER AND
SURGE WILL BE MINIMAL...THEREFORE NO IMPACT IS EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...DUNTEN/JWD
NEAR TERM...JWD
SHORT TERM...WTB
LONG TERM...BELK
AVIATION...JWD
MARINE...JWD
TIDES/COASTAL FLOODING...JWD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
317 AM CDT WED SEP 10 2014
.DISCUSSION...
316 AM CDT
SHORT TERM FORECAST...TODAY THROUGH THURSDAY NIGHT...
CONCERNS IN THE SHORT TERM CONTINUE TO FOCUS ON HEAVY RAINFALL AND
SEVERE THUNDERSTORM POTENTIAL THROUGH TODAY.
AN ELONGATED AREA OF SURFACE LOW PRESSURE STRETCHED FROM THE
OKLAHOMA PANHANDLE INTO CENTRAL IOWA EARLY THIS MORNING...WITH
STRONG SURFACE PRESSURE FALLS OF NEARLY 4 MB PER 3 HRS DEVELOPING
FROM EASTERN IA INTO SOUTHWEST WI AND NORTHWEST IL. THIS IS WHERE
SURFACE LOW WILL CONTINUE TO ORGANIZE AND DEEPEN THIS MORNING IN
RESPONSE TO A STRONG SHORT WAVE TROUGH AND STRENGTHENING UPPER JET
STREAK LIFTING NORTHEAST FROM THE PLAINS. THE LOW WILL CONTINUE TO
LIFT EAST-NORTHEAST ACROSS WI AND LAKE MICHIGAN THROUGH THIS
AFTERNOON...TRAILING A SHARP COLD FRONT ACROSS THE FORECAST AREA
FROM MIDDAY THROUGH EARLY EVENING.
THE AFOREMENTIONED SHORT WAVE OVER THE UPPER MISSISSIPPI VALLEY
WILL CONTINUE EAST-NORTHEAST ACROSS WI/NRN IL EARLY THIS MORNING...
WITH THE BEST HEIGHT FALLS AND DIFFERENTIAL VORTICITY ADVECTION FROM
NOW THROUGH 15Z OR SO. IN ADDITION...STRENGTHENING OF AN UPPER JET
STREAK OVER THE NORTHERN LAKES IS EXPECTED TO PRODUCE A COUPLED
EXIT/ENTRANCE DIVERGENCE REGION OVER THE AREA DURING THE SAME
PERIOD. LOW LEVEL JET WHICH WAS FOCUSED ALONG THE IA/MO BORDER
EARLIER IN THE NIGHT HAS INCREASED TO 50-60 KT FROM THE SOUTHWEST
PER KEAX VAD WIND PROFILE...AND WILL LIKELY INCREASE MOISTURE
TRANSPORT AND THETA-E ADVECTION OVER THE AREA IN THE 09-15Z PERIOD.
EXPECTATION IS THUS THAT THE AREA OF ELEVATED CONVECTION/HEAVY
STRATIFORM PRECIP OVER IA/WESTERN IL AND NRN MO WILL CONTINUE TO
LIFT NORTHEAST ACROSS WRN/NRN IL THROUGH 12Z WITHIN THE STRONGEST
AXIS OF MOISTURE TRANSPORT...BEFORE SHIFTING ACROSS THE CENTRAL AND
SOUTHEASTERN PARTS OF THE CWA AND ACROSS LAKE MICHIGAN BY MID/LATE
MORNING AS SHORT WAVE AND STRONGER FORCING LIFT NORTHEAST AND THE
SURFACE LOW DEVELOPS INTO NORTHEAST WI OR NORTHERN LAKE MICHIGAN BY
EARLY AFTERNOON. UPSTREAM RAINFALL RATES HAVE GENERALLY BEEN
OBSERVED IN THE 0.50-0.75 INCH PER HOUR RANGE IN THE MODERATE TO
HEAVY STRATIFORM PRECIP. SYNOPTIC AND MESOSCALE MODELS ARE IN
GENERALLY DECENT AGREEMENT WITH QPF AMOUNTS AND PLACEMENT THOUGH
TODAY...AND HAVE USED A BLEND OF SUCH GUIDANCE WHICH YIELDS AERIAL
AMOUNTS OF 1.50-1.90 INCHES THROUGH LATE WEDNESDAY. THE NORTHWEST
HALF OF THE CWA SHOULD SEE HEAVIEST AMOUNTS THIS MORNING...WITH THE
SOUTHEAST SEEING MORE OF THEIR RAINFALL THIS AFTERNOON AND VERY
EARLY THIS EVENING AHEAD OF THE COLD FRONT. THESE RAINFALL AMOUNTS
AND RATES ARE NOT LIKELY TO PRODUCE FLASH FLOODING FOR THE MOST
PART...THOUGH AREAS THAT SEE SOME OF THE HEAVIER ELEMENTS TRACK
OVERHEAD FOR A WHILE COULD EXPERIENCE SOME PONDING OF WATER OR MINOR
FLOODING IN TYPICAL LOW SPOTS. HOWEVER...WITH THE FLASH FLOOD WATCH
ALREADY IN PLACE IT WOULD SEEM PREMATURE TO CANCEL THE
HEADLINE...ESPECIALLY WITH THE HEAVIER RAIN JUST ARRIVING EARLY THIS
MORNING.
WITH RESPECT TO THE THREAT OF SEVERE WEATHER...THE LARGE CLUSTER OF
RAIN/EMBEDDED THUNDERSTORMS AND CLOUD COVER ACROSS THE AREA THIS
MORNING WILL LIKELY IMPACT SURFACE TEMPERATURES AND DEVELOPMENT OF
BOUNDARY LAYER ROOTED INSTABILITY THIS AFTERNOON AS THE COLD FRONT
MOVES THROUGH. HOWEVER...THE STRONG DYNAMICS OF THIS EARLY AUTUMN
STORM AND INCREASING DEEP LAYER BULK SHEAR VALUES WITH THE
APPROACHING UPPER JET STREAK THIS AFTERNOON (0-6 KM VALUES 50-60
KTS!) DOES STILL WARRANT SOME RISK OF SEVERE STORMS WITH DAMAGING
WINDS ALONG/SOUTHEAST OF THE COLD FRONT THIS AFTERNOON. SPC HAS
MOVED THE SLIGHT RISK A LITTLE FARTHER SOUTHEAST OF A PONTIAC TO
GARY LINE...AND THIS SEEMS PRUDENT WITH THE POTENTIAL FOR STRONGER
INSTABILITY AND OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES TO BE
FARTHER SOUTH AFTER THIS MORNINGS LARGE MCS.
OUTSIDE OF THE WIND THREAT WITH ANY THUNDERSTORMS TODAY...SOUTH AND
SOUTHWEST WINDS WILL INCREASE WITH THE DEEPENING OF THE LOW PRESSURE
SYSTEM TO OUR NORTH...WITH GUSTS OF 35-40 MPH EXPECTED. IF ANY
SIGNIFICANT DISSIPATION OF CLOUDS AND DESTABILIZATION OCCURS...40-50
KT WINDS JUST ABOVE THE BOUNDARY LAYER COULD BE TAPPED AND RESULT IN
HIGHER WIND GUSTS AHEAD OF THE COLD FRONT. EXTENSIVE DEBRIS CLOUD
COVER AND PRECIP LEND LOW CONFIDENCE TO THAT OCCURRING HOWEVER. WITH
CONSIDERABLE CLOUD COVER EXPECTED MUCH OF THE DAY HAVE TRIMMED HIGH
TEMPS BACK TO THE MID-UPPER 70S.
OTHERWISE...COLD FRONT CLEARS THE SOUTHEAST CORNER OF THE CWA EARLY
THIS EVENING WITH RAIN ENDING FROM THE WEST/NORTHWEST DURING THE
AFTERNOON AND EVENING HOURS. MUCH COOLER AIR ARRIVES OVERNIGHT WITH
TEMPS DIPPING INTO THE 40S ACROSS FAR NORTHERN/NORTH CENTRAL IL.
HIGHS GENERALLY 60-65 EXPECTED THURSDAY...WITH PERHAPS A FEW UPPER
50S ALONG THE FAR NORTH SHORE AREAS.
RATZER
EXTENDED FORECAST...FRIDAY THROUGH TUESDAY...
FRIDAY...
UPPER WAVE CURRENTLY OVER BRITISH COLUMBIA IS PROGGED TO DIG ACROSS
THE UPPER MIDWEST FRIDAY ALONG WITH MUCH COOLER TEMPERATURES ALOFT
WHICH CONTINUES TO SAG SOUTH BEHIND THE STRONG COLD FRONT THAT WILL
COME THROUGH LATER TODAY. H85 TEMPS ARE PROGGED TO FALL INTO THE LOW
SINGLE DIGITS FRIDAY WHICH WHEN COMBINED WITH DIURNAL HEATING WILL
RESULT IN STEEP LOW LEVEL LAPSE RATES. INCREASING ASCENT AHEAD OF
THE UPPER WAVE WILL OVERSPREAD THE AREA WITH CHANCES FOR PRECIP
INCREASING FROM WEST TO EAST DURING THE AFTERNOON HOURS. WARMER
TEMPERATURES IN THE MID LEVEL SHOULD CAP DEEP VERTICAL GROWTH SO
MAINLY LIGHT OCCASIONALLY MODERATE SHOWERS WOULD BE EXPECTED. THERE
MAY BE SOME LAKE ENHANCEMENT THOUGH AS DEEPER LAKE INDUCED
INSTABILITY DEVELOPS OVER LAKE MICHIGAN WHICH STEERING FLOW WILL
DRIVE TOWARDS THE ILLINOIS SHORES. AFTERNOON HIGHS ON FRIDAY ARE
EXPECTED TO BE IN THE UPPER 50S OVER NORTH CENTRAL ILLINOIS TO LOWER
60S ACROSS EAST CENTRAL ILLINOIS AND NORTHWEST INDIANA...AND AROUND
60 BETWEEN INCLUDING THE CHICAGO METRO. WITH THE DEPARTURE OF THE
UPPER WAVE FRIDAY NIGHT AND SURFACE HIGH STARTING TO BUILD INTO THE
WESTERN COUNTIES...CLEARING SKIES AND DECREASING WINDS COULD SET THE
STAGE FOR STRONG RADIATIONAL COOLING FRIDAY NIGHT...RESULTING IN LOW
40S WEST OF THE FOX RIVER VALLEY BY SATURDAY MORNING.
SATURDAY THROUGH TUESDAY...
MOST OF THIS PERIOD SHOULD BE DRY UNDER THE INFLUENCE OF SURFACE
HIGH PRESSURE...WITH THE EXCEPTION OF MONDAY WHEN ANOTHER UPPER
LEVEL DISTURBANCE IS PROGGED TO DIG ACROSS THE REGION FROM CANADA
BRINGING ADDITIONAL CHANCES FOR SHOWERS. TEMPERATURES WILL REMAIN
WELL BELOW NORMAL THROUGH THE PERIOD WITH HIGHS IN THE 60S...BUT
WILL UNDERGO A GRADUAL WARMING TREND PUSHING THE 70 MARK AGAIN BY
TUESDAY.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* RAIN OVERSPREADING THE REGION TONIGHT WITH VERY LOW CHANCES FOR
EMBEDDED THUNDERSTORM.
* THUNDERSTORMS INCREASING IN INTENSITY AND COVERAGE IN THE
PREDAWN HOURS WEDNESDAY AS A LOW LEVEL JET DEVELOPS...ALSO
RESULTING IN LOW LEVEL WIND SHEAR.
* VERY GUSTY S/SSW WINDS DEVELOPING EARLY WEDNESDAY MORNING AND
PERSISTING INTO THE AFTERNOON.
* ADDITIONAL CHANCE FOR THUNDERSTORMS EARLY TO MID AFTERNOON AHEAD
OF A COLD FRONT WHICH WILL SHIFT WINDS TO THE NORTHWEST.
BMD
//DISCUSSION...UPDATED 06Z...
EXPANSIVE AREA OF STRATIFORM RAIN IS OVERSPREADING NORTHERN ILLINOIS
CURRENTLY. STEADY RAIN IS EXPECTED THROUGH MUCH OF THE OVERNIGHT
HOURS AND WHILE CANNOT RULE OUT AN ISOLATED STROKE OF THUNDER HERE
OR THERE...THE INSTABILITY IS RATHER WEAK AND LIGHTNING ACTIVITY IS
VERY MINIMAL AWAY FROM THE LOW LEVEL JET CURRENTLY FOCUSED OVER NRN
MO. THE LOW LEVEL JET IS PROGGED TO SPREAD OVER NORTHERN ILLINOIS
LATE TONIGHT INTO THE PREDAWN HOURS WEDNESDAY MORNING AND SHOULD
ALLOW THUNDERSTORM ACTIVITY TO INCREASE AS 60KT LOW LEVEL WINDS
TRANSPORT VERY MOIST AIR INTO THE REGION ALONG WITH SOME
INSTABILITY. THE MOST FAVORABLE TIMING FOR THESE THUNDERSTORMS
REMAINS IN THE MORNING...PRIMARILY BETWEEN 10-15Z FOR THE CHICAGO
TERMINALS AND AN HOUR OR TWO EARLIER AT RFD. LLWS CONDITIONS ARE
ALSO EXPECTED AS THE LOW LEVEL JET MOVES OVERHEAD. PRECIP SHOULD
WANE IN THE LATE MORNING HOURS AS THE FORCING FROM THE LOW LEVEL JET
MOVES AWAY. MEANWHILE...LOW PRESSURE CURRENTLY CENTERED OVER THE MID
MISSOURI VALLEY WILL LIFT INTO EAST CENTRAL WISCONSIN BY LATE
MORNING WITH A TRAILING COLD FRONT PUSHING ACROSS THE TERMINALS MID
TO LATE AFTERNOON. ADDITIONAL THUNDERSTORMS ARE POSSIBLE IMMEDIATELY
AHEAD AND ALONG THE COLD FRONT AS WE START TO DESTABILIZE AGAIN
DIURNALLY. GUIDANCE REMAINS CONSISTENT THAT THE BULK OF THE ACTIVITY
WILL FORM SOUTHEAST OF RFD...THOUGH COULD FORM VERY NEAR OR OVER THE
CHICAGO TERMINALS. WILL MAINTAIN TEMPO FOR TSRA DURING THE
AFTERNOON. WINDS TURN NORTHWESTERLY BEHIND THE FRONT WITH MUCH
COOLER AIR PUSHING INTO THE REGION. SOME MODELS SUGGEST THAT THIS
COULD RESULT IN A POST FRONTAL MVFR STRATUS TOMORROW EVENING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN RAIN TONIGHT BUT LOW CONFIDENCE IN TSRA
OVERNIGHT.
* MEDIUM CONFIDENCE IN TSRA STARTING IN THE PREDAWN HOURS AND
GOING THROUGH MID MORNING.
* LOW CONFIDENCE IN ADDITIONAL TSRA AHEAD OF THE COLD FRONT.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...LOW-MEDIUM CONFIDENCE
IN WIND GUST MAGNITUDE.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR.
FRIDAY...CHC SHRA.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...SLT CHC SHRA.
BMD
&&
.MARINE...
239 AM CDT
WINDS ARE EXPECTED TO RAMP UP QUICKLY LATER THIS MORNING AS
SIGNIFICANT EARLY AUTUMN STORM SYSTEM SPREADS OVER THE LAKE LATER
THIS MORNING. LOW PRESSURE CURRENTLY OVER IOWA WILL CONTINUE TO THE
NORTHEAST AND STRENGTHEN THROUGH THE MORNING. EXPECT SOUTH WINDS TO
INCREASE TO 40 KT OVER THE SOUTHERN HALF OF THE LAKE TOWARD
DAYBREAK. DO NOT BE CAUGHT OFF GUARD GIVEN THE LIGHTER WINDS
CURRENTLY...AS WINDS WILL INCREASE VERY RAPIDLY AS THIS SYSTEM
APPROACHES AND WAVES WILL RESPOND ACCORDINGLY.
LATER THIS MORNING INTO THE EARLY AFTERNOON WINDS WILL ABATE SOME...THEN
AS THE LOW CONTINUES NORTH AND EAST THROUGH LAKE HURON AND INTO
QUEBEC...A VERY STRONG PRESSURE GRADIENT ON THE BACK SIDE OF THE
LOW COMBINED WITH A SOUTHWARD MOVING COLD FRONT WILL BRING A
PERIOD OF GALE FORCE WINDS ALONG THE NORTHERN HALF OF THE LAKE.
CONFIDENCE STILL REMAINS LOW WITH REGARDS TO GALES DEVELOPING ON
THE SOUTHERN HALF OF THE LAKE IN THE NORTHWEST WINDS BEHIND THE
LOW...BUT IF THE LOW TRACKS A BIT FARTHER SOUTH...GALES STILL
REMAIN POSSIBLE. WHILE WE FEEL THAT WINDS TO 30 KT ARE MORE LIKELY
ON THE SOUTH HALF...FEEL IT IS PRUDENT TO HANG ONTO THE WATCH
LATER THIS EVENING AND WILL OUTLINE THE DETAILS IN THE MARINE
WEATHER WARNING PRODUCT.
REGARDLESS...WAVES WILL BUILD QUICKLY AS WELL THIS MORNING IN
RESPONSE TO THE STRONG WINDS...THEN BUILD AND REMAIN HIGH THROUGH
THE LATTER HALF OF THE WEEK AS NORTH FLOW REMAINS IN PLACE.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ032 UNTIL 1 PM WEDNESDAY.
BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL NOON WEDNESDAY.
FLASH FLOOD WATCH...ILZ023-ILZ033-ILZ039...7 AM WEDNESDAY TO 7
PM WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...7 AM
WEDNESDAY TO 7 PM WEDNESDAY.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 AM WEDNESDAY TO 7 PM
WEDNESDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 PM
WEDNESDAY TO 10 AM THURSDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...5 PM
WEDNESDAY TO 10 AM THURSDAY.
&&
$$
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
[top]
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
256 AM CDT Wed Sep 10 2014
.SHORT TERM...(Today)
ISSUED AT 256 AM CDT WED SEP 10 2014
Heavy rainfall event is commencing across west-central Illinois
early this morning, with 07z/2am radar imagery showing rain across
the western half of the KILX CWA. Further west, very heavy rain and
flash flooding is occurring across northern Missouri, where several
convective systems have trained over the same locations. Latest IR
satellite imagery shows first system dissipating west of Quincy,
while another flare up of convection is developing further west
along the Iowa/Missouri border. This activity is being fed by a
60-65kt 850mb jet streak as seen on the KEAX VWP and is tracking
E/SE along a stationary frontal boundary extending from southern
Iowa into eastern Missouri. As low pressure currently over
southwest Iowa deepens and lifts into Wisconsin later this morning,
this heavier precip area will gradually shift into west-central
Illinois. With precipitable water values exceeding 2 inches, high
rainfall rates of greater than 1 inch per hour will be possible.
Several locations along/west of I-55 already picked up between 1 and
3 inches of rain yesterday, so any additional rainfall could
potentially lead to flash flooding. As a result, current Flash
Flood Watch for much of central Illinois along and north of a
Shelbyville to Paris line will remain in effect today.
Severe weather threat remains uncertain, as widespread showers and
thunderstorms this morning will stabilize a good portion of the
area. Best bet for adequate destabilization this afternoon will be
along southern/eastern periphery of rain area. Based on current
radar trends and 00z model output, think this will mainly be focused
across the S/SE CWA. Latest convective outlook from SPC is trending
in that direction as well, with the slight risk area being shifted
further southeast than previously forecast. South of the precip
area where afternoon high temperatures will reach the lower to
middle 80s, CAPE values will likely reach the 1500 to 2000J/kg range
across southern Illinois into central/southern Indiana. Outflow
boundary from morning convection interacting with this unstable
airmass and strong low-level wind shear will likely produce a line
of strong to severe thunderstorms somewhere along/south of a
Shelbyville to Paris line by mid to late afternoon. Main severe
threat will be damaging wind gusts as the storms sink southeastward
into the evening hours.
&&
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 256 AM CDT WED SEP 10 2014
Low pressure will continue to track northeastward into the Great
Lakes tonight, dragging a strong cold front through central
Illinois. Boundary is progged to be along a Chicago to Saint Louis
line early this evening, then along the Ohio River by Thursday
morning. Based on this timing, will carry categorical PoPs across
the E/SE CWA this evening, tapering down to just chance after
midnight. Further northwest, will mention chance of showers this
evening, followed by dry weather after midnight. Once front
passes, much cooler conditions will be noted on Thursday. Despite
a good deal of sunshine, strong CAA pushing 850mb temps to between
10 and 14c will result in highs only reaching the middle to upper
60s.
Even cooler weather will be on tap for Friday, as 850mb temps drop
further and clouds increase in advance of a lingering 500mb
trough axis. Models continue to show this feature passing Friday
night, accompanied by scattered showers. Latest ECMWF is quite
bullish with its QPF Friday night, while the GFS is much drier.
Think the precip will be mainly diurnal in nature, so am not ready
to raise PoPs significantly for Friday night. Will bring low
chance PoPs across the western half of the CWA Friday afternoon,
then will only go with slight chance PoPs Friday night as daytime
instability fades.
Once this feature passes, strong Canadian high pressure will
dominate the weather this weekend. Resulting high temperatures on
Saturday and Sunday will only be in the 60s, while overnight lows
dip into the 40s. Next northern stream short-wave will swing
through the region early next week, although timing discrepancies
exist among the models. GFS is slightly faster with the feature,
bringing it across central Illinois on Monday, while the ECMWF
delays in until Monday night. Due to timing differences and very
limited moisture supply, have opted to keep the forecast dry through
Tuesday at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1153 PM CDT TUE SEP 9 2014
Showers and a few thunderstorms with light to moderate rain will
progress eastward across central IL the remainder of the night.
Steady rains will eventually reach the Indiana border before
sunrise, including CMI and DEC. PIA will have the better chances
of flooding type rains by morning, as a 45kt low level jet focuses
into WC IL after midnight and moisture pooling increases just
north of the warm front. SPI will be close to the line of storms
and heavy rains approaching from N MO, but it appears there should
be a slight northward drift to keep them just north of SPI. Will
need to watch that closely for due eastward progression, for lower
vis and cigs in heavy rains. At this point, we only tempo`d heavy
rains in PIA between 08z-12z. Most areas should remain VFR, with
short periods of MVFR vis or ceilings in mod/hvy rain. The NAM
keeps indicating LIFR ceilings across the board, but GFS and EC,
and to some extent the RAP soundings do not support that scenario.
Low level wind shear still looks like a good bet for later tonight
for our western TAFs as the southerly LLJ increases to 45kt around
2k FT. We did not include DEC and CMI in the LLWS for now, based
on the latest RAP model output.
As the cold front approaches tomorrow, winds will increase out of
the south-southwest, with gusts to near 30kt at times. There
appears to be decreasing support for strong to severe storms
tomorrow unless we see a significant period of sunshine later
morning and early afternoon ahead of the front. We left just a VCTS
in the afternoon for now.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through this evening FOR ILZ027>031-036>038-
040>042-047>051.
FLASH FLOOD WATCH from 1 PM CDT this afternoon through late
tonight FOR ILZ043>046-052>057-061.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1219 AM CDT WED SEP 10 2014
.DISCUSSION...
1100 PM CDT
FAIRLY STRATIFORM PRECIP WITH SOME EMBEDDED CONVECTION CONTINUES
TO GRADUALLY MAKE EASTWARD PROGRESS INTO CENTRAL AND NORTH-CENTRAL
ILLINOIS IN RESPONSE TO AN UPPER WAVE MOVING EAST-NORTHEAST INTO
WESTERN ILLINOIS AND HAS NOT REALLY INTENSIFIED IN THE LAST FEW
HOURS. THE BETTER CONVECTION CONTINUES ALONG A STATIONARY SURFACE
BOUNDARY ACROSS NORTHERN MISSOURI WHERE AN INCREASING LOW LEVEL
JET IS DEVELOPING. THE SURFACE LOW CONTINUES TO BE ELONGATED FROM
SOUTHWEST IOWA INTO THE TEXAS PANHANDLE. RAIN AND SOME EMBEDDED
THUNDER WILL CONTINUE TO WORK INTO THE WESTERN CWA OVER THE NEXT
FEW HOURS WITH THUNDER BECOMING MORE PREVALENT AS THE RAIN SPREADS
EASTWARD OVERNIGHT. RAIN HAS GENERALLY BEEN LIGHT TO MODERATE IN
INTENSITY TO THE WEST AND THIS WILL LIKELY BE THE CASE AS IT MOVES
INTO THE CWA OVER THE NEXT SEVERAL HOURS. HAVE SLOWED THE EASTWARD
PROGRESS IN THE GRIDS OVERNIGHT.
THE SURFACE LOW WILL CONSOLIDATE WITH PRESSURE FALLS SUGGESTING
THIS WILL OCCUR INTO SOUTHWEST AND CENTRAL IOWA. CONVECTION WILL
LIKELY CONTINUE TO EXPAND TO THE EAST AND SOUTHEAST OF THE SURFACE
LOW BUT ONGOING CONVECTION OVER NORTHERN MISSOURI MAY LIMIT THE
FEED OF MOISTURE AND THEREFORE THE INTENSITY OF THE RAINFALL WHICH
WILL THEN TRACK INTO THE CWA IN THE MORNING. WITH THE LOW PASSING
NEAR OR NORTHWEST OF THE CWA DURING THE MORNING THE THREAT FOR
MORE INTENSE CONVECTION/RAINFALL WILL BE DURING THE MORNING ACROSS
MUCH OF THE AREA. THE NOW STATIONARY BOUNDARY IS EXPECTED TO MARCH
NORTHWARD BUT IT IS NOT CERTAIN HOW QUICKLY THIS WILL OCCUR AND
WILL LIKELY HAVE A ROLE IN CONVECTIVE EVOLUTION THROUGH MIDDAY OR
SO. GIVEN THAT THERE IS STILL PLENTY OF EVOLUTION THAT NEEDS TO
OCCUR WITH THE SURFACE LOW AND THE SHIFTING OF THE LOW LEVEL JET
INTO THE WESTERN CWA WILL CONTINUE WITH THE FLASH FLOOD WATCH
THOUGH THE THREAT THROUGH MUCH OF THE OVERNIGHT APPEARS TO BE
WANING. A RESURGENCE IN INTENSITY REMAINS POSSIBLE FOR EAST AND
SOUTHEAST AREAS WEDNESDAY AFTERNOON AS THE COLD FRONT PASSES SO
WILL MAINTAIN THE HEADLINE THERE AS WELL.
MDB
//PREV DISCUSSION...
335 PM CDT
SHORT TERM...TONIGHT THROUGH FRIDAY...
MAIN CONCERNS FOR THE FORECAST PERIOD REMAIN THUNDERSTORMS AND HEAVY
RAINFALL ASSOCIATED WITH AN UNUSUALLY STRONG LATE SUMMER COLD FRONT
AND UPPER TROUGH IMPACTING THE REGION FROM LATE TONIGHT INTO
WEDNESDAY EVENING. THEN... FOLLOWING THE PASSAGE OF THIS SYSTEM...
THE FOCUS WILL SHIFT TO THE TEMPERATURE FORECAST AND THE FIRST REAL
TASTE OF AUTUMNAL WEATHER FOR LATER THIS WEEK.
FOR THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING...CONDITIONS
WILL BE THE RELATIVE CALM BEFORE THE STORM. THE SFC LOW IS
BEGINNING TO DEEPEN OVER THE CNTRL PLAINS WHILE HIGH PRESSURE MOVES
OFF THE EAST COAST. INCREASING SOUTHERLY FLOW IS RAMPING UP OVER
THE LOWER AND MIDDLE MISSISSIPPI VALLEY...SETTING UP VERY STRONG
WARM/MOIST ADVECTION POINTING INTO THE MIDWEST. THIS
AFTERNOON...CONVECTIVE ACTIVITY HAS ALREADY BROKEN OUT ALONG THE
NOSE OF A 50 KT LOW LEVEL JET...EXTENDING FROM WRN IOWA INTO CNTRL
IL. THIS STRONG LOW LEVEL JET WILL CONTINUE TO PUMP MOISTURE INTO
THE REGION WHILE MOISTURE ASSOCIATED WITH THE REMNANTS OF HURRICANE
NORBERT ADVECT OVER THE REGION AT THE MID LEVELS. THE MODELS HAVE
BEEN VERY CONSISTENT ON ADVERTISING A SWATH OF PWATS OF 2.0 TO 2.5
INCHES POOLING AHEAD OF THE FRONT. THE LOW LEVEL WARM ADVECTION
AHEAD OF THE FRONT...CONVERGENCE ALONG THE FRONT...A STRONG MID
LEVEL SHORTWAVE AND A COUPLED JET ALOFT WILL ALL COMBINE TO GENERATE
STRONG AND PERSISTENT THUNDERSTORMS. THERE SHOULD BE ADEQUATE SHEAR
IN THE LOW LEVELS BETWEEN SLY SFC WINDS AND 50 KT SWLY WINDS AT
925-850MB TO SUPPORT AN INITIAL CONVECTIVE MODE SUPPORTING SOME
ISOLATED SUPERCELLS ALONG WITH THE GENERAL THUNDER. SPC HAS
OUTLOOKED THE ENTIRE CWA WITH A SLIGHT RISK OVER SEVERE
THUNDERSTORMS...WITH THE PRIMARY THREATS BEING STRONG DAMAGING WINDS
AND MARGINALLY SEVERE HAIL. THE 12Z SOUNDINGS FROM ILX/DVN INDICATE
THE FREEZING LEVEL AT 13KFT AND WITH PERSISTENT WARM ADVECTION AHEAD
OF THE COLD FRONT...THE FREEZING LEVEL WILL LIKELY RISE SOME UNTIL
THE FROPA. SO...WHILE THE ENVIRONMENT SHOULD SUPPORT SOME STRONG
ROTATING UPDRAFTS SUFFICIENT FOR LARGE HAIL...THE HIGH FREEZING
LEVELS SHOULD GIVE AMPLE TIME FOR SOME MELTING. AS FOR THE WIND
THREAT...WITH THE STRONG LOW LEVEL JET POINTING OVER THE
AREA...STRONG WINDS SHOULD BE ABLE TO MIX DOWN...PARTICULARLY IN THE
WARM SECTOR AHEAD OF THE FRONT WHERE SURFACE BASED CONVECTION SHOULD
BE ABLE TO FORM. SO...STRONG...DAMAGING WINDS WILL BE A CONCERN
DURING THE INITIAL THUNDERSTORM DEVELOPMENT LATE THIS EVENING.
HEAVY RAINFALL...
THROUGH THE NIGHT...CONVECTIVE MODE WILL TRANSITION OVER TO MORE
LINES OR CLUSTERS...AND EVENTUALLY CONGEALING INTO A LARGE AREA OF
THUNDERSTORMS. WITH FLOW ABOVE THE BOUNDARY LEVEL TO ABOUT 700MB
SWLY...AND WLY-WNWLY JET-LEVEL WINDS...CELL MOVEMENT WITHIN THE
OVERALL THUNDERSTORM AREA WILL BE TO THE NORTHEAST WHILE THE LARGER
SCALE PATTERN IS SLOWLY PROGRESSIVE TO THE EAST. SO...ANTICIPATE
THAT THERE SHOULD BE AMPLE OPPORTUNITY FOR REPEATED DEVELOPMENT OR
TRAINING OF STORMS. ALL ELEMENTS ARE COMING TOGETHER FOR A
SIGNIFICANT HEAVY RAIN EVENT. STORMS WILL BE EFFICIENT RAIN
PRODUCERS GIVEN THE DEEP LAYER MOISTURE AND RAINFALL RATES OF 2 TO 3
INCHES PER HOUR FROM SOME STORMS WILL NOT BE OUT OF THE QUESTION.
FORTUNATELY...THE PATTERN WILL BE SLOWLY...BUT STEADILY
PROGRESSIVE...SO RAINFALL WILL BE WIDESPREAD RATHER THAN CONFINED TO
A SMALL AREA. LATEST THINKING IS THAT STORM TOTAL QPF SHOULD BE
ARND 2.0 TO 2.5 INCHES. IN AREAS OF TRAINING OR REPEATED STORM
DEVELOPMENT...LOCALIZED AREAS OF 3 TO 5 INCHES TOTAL RAINFALL WILL
BE POSSIBLE. THE MOST FAVORED TIMING FOR THE STRONGEST STORMS WILL
BE LATE THIS EVENING AND OVERNIGHT. THERE MAY BE A BRIEF LULL IN
ACTIVITY DURG THE MORNING HOURS...HOWEVER...EXPECT ANOTHER UPTICK IN
ACTIVITY DURG THE LATE MORNING/EARLY AFTERNOON AS THE COLD FRONT
PUSHES THROUGH NWRN INDIANA.
MAJOR CHANGE IN AIRMASS...
FOLLOWING THE FRONTAL PASSAGE WEDNESDAY AFTERNOON AND EVENING...LOW
WILL TURN NWLY TO NLY BEHIND THE FRONT. WEAK CYCLONIC CURVATURE AND
COLD ADVECTION WILL BRING SOME INSTABILITY SHOWERS IN THE COLDER AIR
BEHIND THE FRONT...THROUGH THURSDAY...A BROAD UPPER TROUGH WILL
CARVE OUT OVER THE CNTRL CONUS. A SERIES OF NORTHERN STREAM
SHORTWAVES WILL HELP INCREASE THE AMPLITUDE OF THE UPPER TROUGH
WHILE SUPPLYING MUCH COOLER AIR TO THE REGION. BY THURSDAY
MORNING...TEMPERATURES SHOULD DROP OFF INTO THE MIDDLE 40S OVER THE
NWRN PORTION OF THE CWA...INCLUDING THE ROCKFORD METRO AREA.
SOUTHEAST OF A LINE FROM CHICAGO TO PONTIAC...LOWS THURSDAY MORNING
SHOULD REMAIN IN THE LOWER TO MIDDLE 50S. TEMPERATURES WILL NOT
HAVE MUCH OPPORTUNITY FOR DIURNAL WARMING THROUGH THE DAY GIVEN THE
PERSISTENT COLD ADVECTION...WITH HIGHS THURSDAY ONLY IN THE LOWER TO
MIDDLE 60S. THERE IS EVEN A CHANCE THAT THE ROCKFORD AREA MAY NOT
BE ABLE TO GET OUT OF THE UPPER 50S. BY FRIDAY MORNING...
TEMPERATURES IN THE LOWER TO MIDDLE 40S WILL COVE THE WHOLE
CWA...AWAY FROM THE URBANIZED PORTION OF THE CHICAGO METRO AREA.
FOR FRIDAY...MAX TEMPS SHOULD BE EVEN LOWER THAN THURSDAY...WITH
NCNTRL/NWRN IL REMAINING IN THE MIDDLE 50S WHILE NERN IL/NWRN IN
SHOULD SEE TEMPS LOW OUT IN THE LOW 60S.
KREIN
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...
THE BIG STORY IN THE EXTENDED PERIOD IS THE REINFORCING SHOT OF
UNSEASONABLY COOL AIR THAT WILL BRING EARLY TO MID OCTOBER
TEMPERATURES OVER THE WEEKEND. IN RESPONSE TO PERSISTENT HIGH
AMPLITUDE RIDGING ALONG THE WEST COAST UP TO ALASKA...A DEEP MEAN
TROUGH WILL LOCK IN OVER THE EASTERN HALF OF CANADA INTO THE
NORTHERN TIER OF THE EASTERN HALF OF THE CONUS. THIS MID/UPPER
PATTERN IS SIMILAR TO WHAT OCCURRED MUCH OF WINTER 2013-14 AND
WILL RESULT IN BELOW NORMAL TEMPERATURES CONTINUING INTO EARLY
NEXT WORK WEEK.
GUIDANCE IS CONSISTENT IN BRINGING A QUICK MOVING BUT DEEP SHORT
WAVE TROUGH OR CLOSED LOW ACROSS THE REGION FRIDAY NIGHT...WITH A
DECENT CHANCE FOR A PERIOD OF RAIN SHOWERS. MAINTAINED CHANCE POPS
IN SMART BLEND...BUT THESE MAY NEED TO BE INCREASED IF TRENDS
HOLD. AIR MASS WILL BE ANOMALOUSLY COOL...DIPPING CLOSE TO 0C AT
850 MB OVER FAR NORTHERN ILLINOIS BY 12Z SATURDAY. PROGRESSION OF
SYSTEM WILL BE KEY IN HOW COLD LOWS ARE BY EARLY SATURDAY...AS
LESS PROGRESSIVE/TIGHTER GRADIENT INDICATED BY RECENT ECMWF RUNS
WOULD INTRODUCE CLOUD COVER CONCERNS. STILL...COLD ADVECTION ALONE
LIKELY SUPPORTS LOWS IN 40S EVERYWHERE BUT IMMEDIATE CITY OF
CHICAGO. POTENTIAL DOES EXIST FOR LAKE EFFECT RAIN SHOWERS INTO
SATURDAY MORNING FOR PORTIONS OF SHORE...MAINLY NW IN...BEFORE
SUBSIDENCE ARRIVES FROM EXPANSIVE HIGH PRESSURE SPREADING IN FROM
WEST.
HIGH TEMPERATURES LOOK TO STRUGGLE INTO LOWER 60S SATURDAY
AFTERNOON. ANOMALOUSLY COOL AIR MASS AND GOOD RADIATIONAL COOLING
SETUP WITH HIGH PRESSURE OVERHEAD SATURDAY NIGHT FAVORS AREAS
OUTSIDE CHICAGO DOWN INTO AT LEAST LOWER 40S...WITH UPPER 30S
POSSIBLE IN TYPICAL COLD SPOTS. DID UNDERCUT SMART BLEND
INITIALIZATION FOR LOWS EARLY SUNDAY...AND LOWS IN 30S IN
OUTLYING AREAS COULD BE MORE WIDESPREAD THAN IN CURRENT FORECAST
IF THERE ARE NO CLOUD COVER ISSUES. WITH MEAN TROUGH OVER
REGION...TEMPERATURES WILL REMAIN BELOW NORMAL REMAINDER OF
EXTENDED...THOUGH SLOW MODERATION THROUGH 60S IS EXPECTED SUNDAY
AND MONDAY. PREVIOUS TWO RUNS OF ECMWF INDICATE ANOTHER SHORT
WAVE/REINFORCING COLD FRONT MONDAY/MONDAY NIGHT. CONFIDENCE IS
LOWER IN THIS PERIOD DUE TO FEATURE BEING MUCH LESS ROBUST ON GFS
AND ITS ENSEMBLES. FOR NOW...GRIDS INDICATE A SLIGHT CHANCE FOR
SHOWERS ON MONDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* RAIN OVERSPREADING THE REGION TONIGHT WITH VERY LOW CHANCES FOR
EMBEDDED THUNDERSTORM.
* THUNDERSTORMS INCREASING IN INTENSITY AND COVERAGE IN THE
PREDAWN HOURS WEDNESDAY AS A LOW LEVEL JET DEVELOPS...ALSO
RESULTING IN LOW LEVEL WIND SHEAR.
* VERY GUSTY S/SSW WINDS DEVELOPING EARLY WEDNESDAY MORNING AND
PERSISTING INTO THE AFTERNOON.
* ADDITIONAL CHANCE FOR THUNDERSTORMS EARLY TO MID AFTERNOON AHEAD
OF A COLD FRONT WHICH WILL SHIFT WINDS TO THE NORTHWEST.
BMD
//DISCUSSION...UPDATED 06Z...
EXPANSIVE AREA OF STRATIFORM RAIN IS OVERSPREADING NORTHERN ILLINOIS
CURRENTLY. STEADY RAIN IS EXPECTED THROUGH MUCH OF THE OVERNIGHT
HOURS AND WHILE CANNOT RULE OUT AN ISOLATED STROKE OF THUNDER HERE
OR THERE...THE INSTABILITY IS RATHER WEAK AND LIGHTNING ACTIVITY IS
VERY MINIMAL AWAY FROM THE LOW LEVEL JET CURRENTLY FOCUSED OVER NRN
MO. THE LOW LEVEL JET IS PROGGED TO SPREAD OVER NORTHERN ILLINOIS
LATE TONIGHT INTO THE PREDAWN HOURS WEDNESDAY MORNING AND SHOULD
ALLOW THUNDERSTORM ACTIVITY TO INCREASE AS 60KT LOW LEVEL WINDS
TRANSPORT VERY MOIST AIR INTO THE REGION ALONG WITH SOME
INSTABILITY. THE MOST FAVORABLE TIMING FOR THESE THUNDERSTORMS
REMAINS IN THE MORNING...PRIMARILY BETWEEN 10-15Z FOR THE CHICAGO
TERMINALS AND AN HOUR OR TWO EARLIER AT RFD. LLWS CONDITIONS ARE
ALSO EXPECTED AS THE LOW LEVEL JET MOVES OVERHEAD. PRECIP SHOULD
WANE IN THE LATE MORNING HOURS AS THE FORCING FROM THE LOW LEVEL JET
MOVES AWAY. MEANWHILE...LOW PRESSURE CURRENTLY CENTERED OVER THE MID
MISSOURI VALLEY WILL LIFT INTO EAST CENTRAL WISCONSIN BY LATE
MORNING WITH A TRAILING COLD FRONT PUSHING ACROSS THE TERMINALS MID
TO LATE AFTERNOON. ADDITIONAL THUNDERSTORMS ARE POSSIBLE IMMEDIATELY
AHEAD AND ALONG THE COLD FRONT AS WE START TO DESTABILIZE AGAIN
DIURNALLY. GUIDANCE REMAINS CONSISTENT THAT THE BULK OF THE ACTIVITY
WILL FORM SOUTHEAST OF RFD...THOUGH COULD FORM VERY NEAR OR OVER THE
CHICAGO TERMINALS. WILL MAINTAIN TEMPO FOR TSRA DURING THE
AFTERNOON. WINDS TURN NORTHWESTERLY BEHIND THE FRONT WITH MUCH
COOLER AIR PUSHING INTO THE REGION. SOME MODELS SUGGEST THAT THIS
COULD RESULT IN A POST FRONTAL MVFR STRATUS TOMORROW EVENING.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN RAIN TONIGHT BUT LOW CONFIDENCE IN TSRA
OVERNIGHT.
* MEDIUM CONFIDENCE IN TSRA STARTING IN THE PREDAWN HOURS AND
GOING THROUGH MID MORNING.
* LOW CONFIDENCE IN ADDITIONAL TSRA AHEAD OF THE COLD FRONT.
* MEDIUM-HIGH CONFIDENCE IN WIND DIRECTION...LOW-MEDIUM CONFIDENCE
IN WIND GUST MAGNITUDE.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR.
FRIDAY...CHC SHRA.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...SLT CHC SHRA.
BMD
&&
.MARINE...
221 PM CDT
THE MAIN FORECAST CONCERNS CONTINUE TO CENTER AROUND A SIGNIFICANT
STORM SYSTEM EXPECTED TO IMPACT THE GREAT LAKES WEDNESDAY AND
WEDNESDAY NIGHT.
SOUTHERLY WINDS ARE EXPECTED TO INCREASE RAPIDLY LATE TONIGHT AS A
STRENGTHENING AREA OF LOW PRESSURE MOVES FROM IOWA INTO SOUTHWESTERN
WISCONSIN. SOUTHERLY GALES OF 35 TO 40 KT ARE EXPECTED BY EARLY
MORNING ACROSS APPROXIMATELY THE SOUTHERN HALF OF THE LAKE...AND
THESE STRONG WINDS WILL CONTINUE THROUGH THE AFTERNOON. THE LOW IS
THEN EXPECTED TO SHIFT ACROSS THE NORTHERN PORTION OF THE LAKE BY
WEDNESDAY EVENING...AND THIS SHOULD RESULT IN A SHORT PERIOD OF
LIGHT AND VARIABLE WINDS NEAR ITS TRACK EARLY THURSDAY EVENING.
HOWEVER...ONCE THIS LOW SHIFTS EAST OF THE LAKE BY LATER WEDNESDAY
EVENING...A STRONG COLD FRONT WILL PUSH OVER THE LAKE. THIS SHOULD
ALLOW FOR A PERIOD OF STRONG NORTH-NORTHWESTERLY WINDS OVER THE LAKE
INTO THURSDAY. AT THIS TIME...IT APPEARS THE MAIN THREAT FOR GALES
MAY SHIFT OVER THE NORTHERN HALF OF THE LAKE INTO EARLY THURSDAY
MORNING...WITH NEAR GALE FORCE WINDS POSSIBLE OVER THE SOUTHERN END
OF THE LAKE.
WINDS WILL GRADUALLY ABATE SOME INTO THE LATER PORTION OF THE WEEK
AS HIGH PRESSURE BUILDS IN ACROSS THE PLAINS AND UPPER MIDWEST.
HOWEVER...THE NORTHERLY FETCH WILL LIKELY CONTINUE TO PRODUCE SOME
HIGHER 4 + FOOT WAVES THROUGH AT LEAST FRIDAY. ANOTHER SYSTEM COULD
IMPACT PORTIONS OF THE LAKE ON SATURDAY...POSSIBLY LEADING TO A
PERIOD OF ENHANCED NORTHERLY WINDS AGAIN. HOWEVER...UNCERTAINTY IS
HIGH WITH THIS SYSTEM. IF THE SYSTEM DOES PAN OUT...IT COULD RESULT
IN WAVES HIGH ENOUGH TO SUPPORT A SMALL CRAFT ADVISORY INTO
SATURDAY.
AS FOR HEADLINES...WE HAVE ISSUED A GALE WARNING FOR THE SOUTHERN
HALF OF THE LAKE...INCLUDING THE NEAR SHORES...FOR THE DAY ON WED
WHEN STRONG SOUTHERLY WINDS ARE EXPECTED. DUE TO UNCERTAINTIES ON HOW
STRONG THE NORTHERLY WINDS WILL BE ON OVER SOUTHERN LAKE MICHIGAN ON
THE BACK SIDE OF THE SYSTEM...WE HAVE OPTED TO KEEP THE WATCH IN
PLACE FOR WEDNESDAY NIGHT FOLLOWING THE SOUTHERLY GALE EVENT.
HOWEVER...OVER THE NORTHERN PORTION OF THE LAKE NORTHERLY GALES
APPEAR MORE LIKELY WEDNESDAY NIGHT..SO WE HAVE ISSUED THE GALE
WARNING THERE FOR WEDNESDAY EVENING THROUGH EARLY THURSDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ032 UNTIL 1 PM WEDNESDAY.
BEACH HAZARDS STATEMENT...ILZ006-ILZ014...5 AM WEDNESDAY TO NOON
WEDNESDAY.
FLASH FLOOD WATCH...ILZ023-ILZ033-ILZ039...7 AM WEDNESDAY TO 7
PM WEDNESDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...7 AM
WEDNESDAY TO 7 PM WEDNESDAY.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 AM WEDNESDAY TO 7 PM
WEDNESDAY.
GALE WATCH...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...7 PM
WEDNESDAY TO 10 AM THURSDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...5 PM
WEDNESDAY TO 10 AM THURSDAY.
&&
$$
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
NATIONAL WEATHER SERVICE LINCOLN IL
1153 PM CDT Tue Sep 9 2014
.UPDATE...
ISSUED AT 900 PM CDT TUE SEP 9 2014
The 35-45kt low level jet around 850mb is progressing toward IL
from the SW. Moisture transport is increasing as a result, with
PWAT values climbing toward 2 inches. The nearly stationary warm
from angled from NW to SE in eastern Missouri will continue to
provide a lifting mechanism for shower/storm development the rest
of the night.
A progressive MCS is forecast by the high res models to move from
NW Missouri across N IL overnight, which will possibly clip our NW
counties after midnight. Areas NW of the IL river will have the
best chances of getting heavy rain and strong winds from that
complex. We kept categorical PoPs for that area overnight, with
heavy rain in the grids. The flash flood watch coverage still
looks good for timing and coverage. No changes will be needed
there.
The severe threat for Wed afternoon still hinges greatly on the
amount of sunshine that develops ahead of the cold front. Wind
shear will be present, as well as plenty of moisture, so
instability will be the question-mark. Forecast soundings show
limited instability even during the afternoon due to a moist
adiabatic profile, but areas of clearing and heating can quickly
produce high CAPEs. Will keep tomorrows forecast as is, with
severe potential for nearly all of our counties except western
portions of Knox and Stark counties.
Even update mainly for weather/PoPs.
&&
.SHORT TERM...(Tonight)
ISSUED AT 305 PM CDT TUE SEP 9 2014
Issued a flash flood watch for areas from I-55 west from this
afternoon through 7 pm Wed. Issued flash flood watch for east
central IL for Wed afternoon and Wed evening. MCS still affecting
a part of central IL with showers and thunderstorms sw of I-74 and
west of I-57. Thunderstorms with heavy rains over parts of Morgan
and southern Sangamon counties. Have increased chances of showers
and thunderstorms over central and western areas tonight with
heaviest rains shifting into areas nw of the IL river during the
night. SPC continues a slight risk of severe storms from I-55 nw
into tonight with main threat damaging wind gusts where 30% risk
nw of IL river. Muggy lows in the upper 60s to around 70F with
south southeast winds prevailing tonight.
&&
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 305 PM CDT TUE SEP 9 2014
Showers and thunderstorms will likely be ongoing to start the day
for much of the forecast area west of I-55. This convective complex
will be tied fairly closely to a deepening surface low that will be
lifting into the Great Lakes region during the day. East of I-55 the
day will likely start out dry. Then, attention turns to the cold
front trailing from the surface low. This strong front will sweep
through the forecast area, mainly during the Wednesday afternoon and
evening hours. Unfortunately, there are still model disagreements
with the speed of the front, differences that will likely have a
significant impact on our severe weather threat. The ECMWF remains
the slowest, while the NAM has trended faster and is now closer to
the GFS speed. However, WPC does not favor the NAM`s recent trend of
a deeper surface low and associated faster frontal speed. So, will
continue to favor the more consistent ECMWF (although the GFS has
been fairly consistent with is quicker solution).
Severe storms and heavy rainfall are still a threat until the cold
front clears the area. The main severe storm threat still appears to
be in the Wednesday afternoon/evening hours along/ahead of the cold
front where the best pre-frontal instability (1500-2500 j/kg) and
bulk shear (35-45 kts) will be co-located. However, if a faster
frontal speed verifies, the instability will likely end up quite a
bit lower and reduce the severe threat. Any storms until the front
clears the area have the potential to be heavy rain producers, with
precipitable water values apt to be in excess 2 inches.
Once the strong cold front clears the area by late Wednesday night,
a much cooler than normal weather pattern should linger through the
end of the forecast period. Upper level troffing should remain in
place, accompanied by a Canadian surface high more often than not.
There are still some stronger waves expected to track through the
mean trof that may produce rainfall. However, model agreement in
this regard still leaves much to be desired, especially next week.
At this point, the best model clustering suggests showers are
possible later Friday into Friday night, and this is the only period
I have left slight chances for showers in place. Temperatures to
start the period should average 60s for highs and 40s for lows,
climbing into the 70s and 50s respectively by the end of the period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1153 PM CDT TUE SEP 9 2014
Showers and a few thunderstorms with light to moderate rain will
progress eastward across central IL the remainder of the night.
Steady rains will eventually reach the Indiana border before
sunrise, including CMI and DEC. PIA will have the better chances
of flooding type rains by morning, as a 45kt low level jet focuses
into WC IL after midnight and moisture pooling increases just
north of the warm front. SPI will be close to the line of storms
and heavy rains approaching from N MO, but it appears there should
be a slight northward drift to keep them just north of SPI. Will
need to watch that closely for due eastward progression, for lower
vis and cigs in heavy rains. At this point, we only tempo`d heavy
rains in PIA between 08z-12z. Most areas should remain VFR, with
short periods of MVFR vis or ceilings in mod/hvy rain. The NAM
keeps indicating LIFR ceilings across the board, but GFS and EC,
and to some extent the RAP soundings do not support that scenario.
Low level wind shear still looks like a good bet for later tonight
for our western TAFs as the southerly LLJ increases to 45kt around
2k FT. We did not include DEC and CMI in the LLWS for now, based
on the latest RAP model output.
As the cold front approaches tomorrow, winds will increase out of
the south-southwest, with gusts to near 30kt at times. There
appears to be decreasing support for strong to severe storms
tomorrow unless we see a significant period of sunshine later
morning and early afternoon ahead of the front. We left just a VCTS
in the afternoon for now.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through Wednesday evening FOR ILZ027>031-
036>038-040>042-047>051.
FLASH FLOOD WATCH from Wednesday afternoon through late
Wednesday night FOR ILZ043>046-052>057-061.
&&
$$
UPDATE...SHIMON
SHORT TERM...07
LONG TERM...BAK
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1149 PM CDT TUE SEP 9 2014
.UPDATE...
ISSUED AT 905 PM CDT TUE SEP 9 2014
REALLY THE ONLY CONCERN TONIGHT IS HEAVY RAIN AND FLOODING AS SEVERE
THREAT VERY LOW WITH SATURATED SOUNDING AND LIMITED SUB CLOUD
BUOYANCY.
LINEAR MCS CONTINUES SAGGING S/SE INTO LOW LEVEL MOIST AXIS AND IS
INTERCEPTING MAIN LOW LEVEL JET AND MOISTURE TRANSPORT FEED.
MUCH OF CONVECTION AND HEAVY RAIN CONCERNS WILL EXIST NEAR TO SOUTH
OF I-80 REST OF EVE... WITH STRATIFYING PCPN SHIELD ACROSS NORTH.
CONCERNS EXIST THAT THE LONGER THIS CONVECTION CONTINUES TO OUR
SOUTH TONIGHT INTERRUPTING FOCUS OF LOW LEVEL JET AND MOISTURE
FEED...THE MORE UNCERTAINTY EXISTS WITH HEAVY RAIN THREAT
DEVELOPING ACROSS NORTHERN CWA... ALTHOUGH CANNOT BE RULED OUT IF
STORMS CAN WEAKEN TO OUR SOUTH ALLOWING LOW LEVEL JET TO REFOCUS
FURTHER NORTH WITH NORTHWARD LIFTING WARM FRONT. HAVE TRENDED
FORECASTS TOWARD HEAVIER RAINS TONIGHT ACROSS SOUTHERN HALF OF THE
CWA... BUT WILL MAINTAIN FLASH FLOOD WATCH ALL AREAS DUE TO UNCERTAINTY.
&&
.SYNOPSIS...
ISSUED AT 330 PM CDT TUE SEP 9 2014
LOW PRESSURE OVER EXTREME SOUTHEAST CO HAD A WARM FRONT EXTENDED
INTO NORTHERN MO INTO SOUTHERN IL. TEMPERATURES TO THE SOUTH OF
THE FRONT WERE WELL IN THE 80S TO MID 90S WITH DEWPOINTS IN THE
LOWER TO MID 70S. SBCAPES OF 4000 J/KG WERE OCCURRING IN WESTERN
MO. TO THE NORTH OF THE FRONT IN THE RAIN COOLED AIR READINGS WERE
ONLY IN THE UPPER 60S TO UPPER 70S. THE BEST PRESSURE FALLS WERE
LOCATED IN WESTERN KS. PRECIPITABLE WATERS WERE AS HIGH AS 1.9 INCHES
IN NORTHERN MO.
DOPPLER RADAR CONTINUED TO SHOW FESTERING SHOWERS AND A FEW
THUNDERSTORMS FROM EASTERN NEB INTO SOUTHEAST IA AND CENTRAL IL
WITH WARM AIR ADVECTION INTO THE AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT TUE SEP 9 2014
HEADLINES...NOW THAT MUCH OF THE AREA HAS SATURATED SOILS THE
FLASH FLOOD WATCH WILL CONTINUE TONIGHT INTO WEDNESDAY MORNING
FOR THE ENTIRE CWA.
TONIGHT...ADDITIONAL RAINFALL OF 1 TO 3 INCHES APPEAR LIKELY. SOME
LOCATIONS MAY RECEIVE 4 TO 6 INCHES...ESPECIALLY IN ANY TRAINING/REPEATING
STORMS. THIS AMOUNT OF RAIN ON VERY SATURATED SOILS WOULD CAUSE SERIOUS
FLASH FLOODING. PRECIPITABLE WATERS WILL BE AT NEAR RECORD VALUES
FOR SEPTEMBER...ABOUT 2.2 INCHES. THIS IS DUE TO RICH GULF MOISTURE
COMBINED WITH MOISTURE FROM THE REMNANTS OF WHAT WAS MAJOR PACIFIC
HURRICANE NORBERT. RAINFALL RATES WILL BE EXTREMELY HIGH SO VERY
TORRENTIAL RAINS WILL ACCOMPANY THESE STORMS. CONFIDENCE IS VERY
HIGH FOR THIS FLASH FLOOD EVENT BUT IS LOWER FOR THE SEVERE THREAT.
THERE IS THE POTENTIAL FOR LOCALIZED WET MICROBURSTS DUE TO THE
VERY SATURATED ATMOSPHERE BUT ANY HAIL SHOULD REMAIN BELOW SEVERE
LEVELS. I AM CONCERNED FOR THE POTENTIAL FOR AN ISOLATED TORNADO
OR TWO ON ANY BOUNDARY AS THE DEEP LAYER SHEAR BECOMES VERY STRONG
EVEN WELL AFTER DARK AS THE SURFACE LOW DEEPENS AND TRACKS TOWARDS
LA CROSSE WI BY 12Z WEDNESDAY. THE HRRR MESO MODEL SUGGESTS ACTIVITY
INCREASING IN OUR SOUTHERN CWA LATE THIS AFTERNOON OR TOWARDS EVENING
THEN SPREADING NORTHEAST AS THE EVENING PROGRESSES...WITH WIDESPREAD
STORMS THEN OCCURRING OVERNIGHT. SOME OF THE STRONGER STORMS WILL
ALSO PRODUCE FREQUENT TO CONTINUOUS DANGEROUS LIGHTNING. MINIMUM
TEMPERATURES WILL BE IN THE MID 60S TO LOWER 70S.
WEDNESDAY...DEEPENING CYCLONE WILL TRACK INTO THE GREAT LAKES REGION
SENDING A STRONG COLD FRONT INTO OUR WESTERN CWA IN THE MORNING AND
OUR EASTERN CWA IN THE EARLY AFTERNOON. THE THUNDERSTORMS WILL GRADUALLY
DIMINISH AND SHIFT TO THE EAST OF THE CWA WITH THE FRONT. THE SEVERE
THREAT APPEARS TO BE FARTHER TO THE EAST THAN EARLIER THOUGHT AND SPC
HAS THE SLIGHT RISK ONLY IN OUR FAR SOUTHEAST COUNTIES...BUT THIS WILL
DEPEND ON CLOUD COVER AND AMOUNT OF INSTABILITY. MAXIMUM TEMPERATURES
SHOULD RANGE FROM THE UPPER 60S AT INDEPENDENCE IA TO THE UPPER 70S
IN OUR FAR EAST/SOUTHEAST COUNTIES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH NEXT TUESDAY)
ISSUED AT 330 PM CDT TUE SEP 9 2014
WEDNESDAY NIGHT THROUGH FRIDAY...SEASONABLY STRONG RIDGE STILL ON
TRACK TO DUMP DOWN THE PLAINS AND UPPER MS RVR VALLEY THIS PERIOD.
EXPECT MOST POST-FRONTAL RAINS TO BE OUT OF THE CWA AT START OF THE
PERIOD...WITH JUST DEEPENING LLVL NORTHERLY FLOW COOL ADVECTING AND
SCORING OUT THE CLOUD COVER EVENTUALLY BY THU MORNING. EVEN IF CLOUD
COVER HOLDS ON TIL DAYLIGHT...LOWS TO BE ADVECTED DOWN INTO THE 40S
IN MOST OF THE CWA. INCOMING CANADIAN AIR TO WARM ONLY INTO THE 60S
THU EVEN WITH SOME SUNSHINE...WITH A QUICK DROP OFF AFTER SUNSET THU
EVENING INTO THE 40S BEFORE INCREASING CLOUDS AHEAD OF THE NEXT
SYSTEM TOWARD FRI MORNING HALTS TEMP DROP OFF. STILL SOME PHASING
ISSUES TO BE HAMMERED OUT...BUT LATEST RUN MEDIUM RANGE SOLUTIONS
SUGGEST SOME TYPE OF WAVE/POSSIBLY RATHER VIGOROUS...TO ROLL ACRS
THE REGION ON FRI. THIS SYSTEM WILL NOT HAVE NEAR THE MOISTURE
SOURCE OR THERMODYNAMICS TO WORK WITH AS THE CURRENT SYSTEM...BUT
STILL SHOULD INDUCE A RAIN SHIELD THAT WILL OVERSPREAD MOST OF THE
CWA FROM WEST TO EAST AS FRI PROGRESSES. CLOUD COVER AND PRECIP TO
KEEP A LID ON TEMPS WITH MOST AREAS HELD IN THE 50S OR EVEN UPPER 40S
AND NORTH WINDS MAKING FOR A RAW DAY. CURRENT INDICATIONS SUGGEST
MOST AREAS TO GET FROM 0.10 UP CLOSE TO HALF AN INCH BY THE TIME THE
RAIN PULLS OUT FRI EVENING. MODELS STILL VARYING ON PRECIP AND CLOUD
COVER EXIT TIMING LATER FRI NIGHT...BUT WILL JUST KEEP PRECIP IN THE
EVENING FOR NOW. POST-WAVE SUBSIDENCE MAY MAKE FOR A LATE NIGHT
CLEAR OUT...BUT SOME CHANCE FOR SUBSIDENCE INVERSION TO TRAP CLOUDS
INTO SAT MORNING LIMITING FRI NIGHT/SAT MORNING COLD POTENTIAL. THE
GFS CONTINUES TO BE THE COLD MODEL WITH SOME UPPER 30S IN THE
NORTHWESTERN THIRD OF THE DVN CWA AND LOWER 40S ELSEWHERE. THE ECMWF
MORE IN THE WAY OF LOW TO MID 40S BUT KEEPS THE CLOUD COVER AND SOME
MIXING SFC WINDS GOING INTO SAT MORNING. WITH EXTENT OF INCOMING
UNSEASONABLY COLD AIRMASS...FEEL WITH ANY KIND OF CLEAR OUT/PARTIAL
CLEARING AND SFC WIND DROP OFF UNDER 10 MPH LATE FRI NIGHT...THE
COOLER GFS WILL PREVAIL.
SATURDAY AND SUNDAY...HIGHS ONLY RECOVERING INTO THE UPPER 50S TO
MID 60S SAT UNDER WEAK MIXING REGIME OF CANADIAN HIGH PRESSURE...
THEN HOW COLD TO GO SAT NIGHT THE CHALLENGE. IF LLVL RETURN FLOW
DOES NOT MATERIALIZE IN TIME AND THE SFC RIDGE PERSISTS LONGER
BEFORE EASTWARD MIGRATION...SAT NIGHT MAY BE THE COOLER OF THE TWO
COLD WINDOW NIGHTS BEING WATCHED RIGHT NOW...MORE IDEAL RADIATIONAL
COOLING PARAMETERS IN LINE POSSIBLY. MORE WIDESPREAD MID TO UPPER 30S
POSSIBLE ESPECIALLY EAST OF THE MS RVR CLOSER TO RIDGE CENTER. WAA
ON BACK SIDE OF RIDGE COMPLEX MAY GENERATE SOME ELEVATED SHOWERS
INTO THE WESTERN CWA BY LAT SUNDAY NIGHT...BUT CONFIDENCE LOW ON
THAT SCENARIO.
MONDAY THROUGH NEXT TUESDAY...NEXT WAVE WILL LOOK TO SHEAR ACRS THE
UPPER MIDWEST SOMETIME THIS PERIOD FOR THE NEXT RAIN CHANCE...WITH
THE 12Z RUN ECMWF MORE PHASED AN ORGANIZED WITH THIS SYSTEM MON
NIGHT INTO TUE FOR MORE SIGNIFICANT PRECIP AS OPPOSED TO THE GFS. ..12..
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1142 PM CDT TUE SEP 9 2014
CONDITIONS TO CONTINUE DETERIORATING TO WIDESPREAD MVFR WITH AREAS
OF IFR IN LOW CLOUDS OVERNIGHT WITH OCCASIONAL RAIN... AND SOME
STORMS MAINLY SOUTH OF I-80. WINDS OVERNIGHT WILL BE FROM THE EAST
AND SOUTHEAST AROUND 10 KTS AND GUSTY. STRONG COLD FRONT WILL PASS
THROUGH THE TERMINALS FROM MID AM THROUGH EARLY PM ON WED WITH
SHIFT TO GUSTY NORTHWEST WINDS. PCPN TO DIMINISH WITH FRONTAL
PASSAGE WITH LINGERING MVFR TO AREAS OF IFR CIGS LIKELY LIFTING TO
VFR AND SCATTERING OUT LATE PM AND EVE WITH INCOMING SUBSIDENCE.
&&
.HYDROLOGY...
THE RIVER WATCH WILL BE ON THROUGH MID WEEK. AFTER LAST NIGHT/S AND
THIS MORNINGS RAINS...ANOTHER 1-4 INCHES TONIGHT INTO WED MORNING
WILL DEFINITELY PRODUCE SOME FLOODING ON AREA TRIBUTARIES...DEPENDING
ON HOW WIDESPREAD THE ADDITIONAL HEAVY RAIN WILL FALL IN THE LOCAL
AREA OF CONCERN. RIVER BASINS TO WATCH FOR FLOODING POTENTIAL ON SOME
OF THE FCST POINTS FROM WED THROUGH FRI MORNING ARE THE SKUNK...
CEDAR...IOWA...WAPSI...ENGLISH...AND DES MOINES RIVERS. THE
MAQUOKETA MAY GET CLOSE. IF NOT FLOODING THEN SIGNIFICANT WITHIN BANK
RISES TO OCCUR. ..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...FLASH FLOOD WATCH UNTIL 7 AM CDT WEDNESDAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...FLASH FLOOD WATCH UNTIL 9 AM CDT WEDNESDAY FOR BUREAU-CARROLL-
HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-MERCER-
PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...FLASH FLOOD WATCH UNTIL 7 AM CDT WEDNESDAY FOR CLARK-SCOTLAND.
&&
$$
UPDATE...05
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...12
AVIATION...05
HYDROLOGY...12
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
215 AM CDT WED SEP 10 2014
...UPDATE TO LONG TERM...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 204 PM CDT TUE SEP 9 2014
LATEST RAP 400MB POTENTIAL VORTICITY APPEARS TO HAVE A DECENT
HANDLE WITH AN UPPER LEVEL DISTURBANCE THAT WAS CROSSING THE
COLORADO ROCKIES AT 18Z. GIVEN THE 18Z VERIFICATION WILL STAY
CLOSE TO THE RAP ON TIMING OF THIS UPPER LEVEL FEATURE AS IT
CROSSES EASTERN COLORADO AND WESTERN KANSAS LATER THIS EVENING.
GIVEN LATE DAY INSTABILITY AND LOCATION OF LOW LEVEL FORCING AHEAD
OF THIS UPPER LEVEL TROUGH NEAR A SURFACE BOUNDARY THAT WILL
EXTEND FROM SOUTHEAST COLORADO INTO NORTH CENTRAL KANSAS THERE
WILL BE A CHANCE FOR SCATTERED THUNDERSTORMS LATE THIS AFTERNOON
ACROSS NORTH CENTRAL KANSAS AND PORTIONS OF WEST KANSAS. BASED ON
THE 21Z TUESDAY AND 00Z WEDNESDAY CAPE AND 0-6KM SHEAR FROM THE
NAM A FEW STORMS LATE TODAY MAY BE SEVERE WITH THE AREA MORE
FAVORABLE FOR HAIL GOLF BALL SIZE OR LARGER ALONG WITH WIND GUST
IN EXCESS OF 60 MPH WILL BE ALONG AND NORTH OF A DIGHTON AND
LARNED LINE.
THUNDERSTORMS WILL THEN INCREASE IN AREAL COVERAGE EARLY TONIGHT
AS THE UPPER LEVEL DISTURBANCE CROSSES THE CENTRAL HIGH PLAINS AND
A SURFACE BOUNDARY MOVES ACROSS SOUTHWEST KANSAS. THE AREA THAT
WILL BE MORE FAVORABLE FOR WIDESPREAD THUNDERSTORMS EARLY TONIGHT
WILL BE ALONG AND NORTH OF A 700MB +10C TO +13C BAROCLINIC ZONE.
GIVEN THE 12Z NAM AND 12Z GFS THIS FAVORABLE AREA WILL BE
NORTHEAST OF A SYRACUSE TO DODGE CITY THE PRATT LINE. ALSO GIVEN
THE HIGH PRECIPITABLE WATER VALUES PERIODS THERE WILL BE A CHANCE
FOR PERIODS OF HEAVY RAIN IN THIS AREA AS WELL.
BUFR SOUNDINGS INDICATING WINDS NEAR THE SURFACE BEHIND THE COLD
FRONT WILL RANGE FROM 20 TO 30 KNOTS AS THE LOWER LEVELS BEGIN TO
SATURATE. BY 12Z WEDNESDAY THE DEPTH OF THIS LOW LEVEL MOISTURE
APPROACHES 3000FT WHICH SUPPORTS INSERTING A SLIGHT CHANCE FOR
LIGHT DRIZZLE FOR SEVERAL HOURS EARLY WEDNESDAY MORNING. BY LATE
MORNING THIS LOW LEVEL MOISTURE WILL BEGIN TO ERODE FROM SOUTHWEST
NORTHEAST AND GIVEN SOME AFTERNOON SUNSHINE ACROSS SOUTHWEST AND
SOUTH CENTRAL KANSAS THE HIGHS ARE EXPECTED TO CLIMB BACK INTO THE
MID 70S BASED ON THE 00Z THURSDAY 850MB TEMPERATURES. FURTHER
NORTH, NEAR THE INTERSTATE 70 CORRIDOR THE CLOUDS AND 850MB
TEMPERATURES AT 00Z THURSDAY SUGGEST HIGHS ON IN THE UPPER 60S TO
NEAR 70.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 215 AM CDT WED SEP 10 2014
ON THURSDAY, SFC CYCLOGENESIS WILL INCREASE ACROSS SOUTHEASTERN COLORADO.
THERE WILL BE A FAIRLY TIGHT TEMPERATURE GRADIENT AHEAD OF AN APPROACHING
COLD FRONT. CALLING FOR MID 60S ALONG THE INTERSTATE 70 CORRIDOR TO
MID 70S NEAR THE OKLAHOMA BORDER. NO PRECIPITATION IS EXPECTED UNTIL
LATE EVENING.
A STRONG FRONT IS FORECAST TO MOVE ACROSS WESTERN KANSAS AROUND 06Z
AND TOTALLY CLEARING THE FORECAST AREA BY 12Z FRIDAY. THIS FRONT HAS
CONSIDERABLE COLD AIR ADVECTION BEHIND IT WITH THE 850-HPA 0C ISOTHERM
FLIRTING WITH THE NORTHERN COUNTIES. THE WESTERN COUNTIES (GCK AND WEST)
STAND TO SEE THE MOST PRECIPITATION OF HALF OF AN INCH TO 1 INCH. FARTHER
EAST, LESS AMOUNTS ARE FORECAST AND EXPECTED. TEMPERATURES WILL STRUGGLE
TO GET OUT OF THE 50S AND CONSIDERABLE CLOUD COVER IS EXPECTED THROUGH
THE MAJORITY OF THE DAY. IT WILL FEEL VERY FALL-LIKE FRIDAY.
SURFACE HIGH PRESSURE WILL RIDGE OVER THE AREA SATURDAY MORNING WITH
THE COLDEST TEMPERATURES FORECAST OF THE SEASON SO FAR. FORECAST UPPER
30S ALONG AND NORTH OF HIGHWAY 96. THERE COULD BE SOME PATCHY FROST
TOO.
GOOD NEWS IF YOU ARE A FAN OF WARM TEMPERATURES. THE COOL SPELL WON`T
LAST LONG AND LOW LEVEL WARM AIR ADVECTION WILL BEGIN SATURDAY WITH
70S RETURNING TO THE AREA.
RELATIVELY TRANQUIL WEATHER WILL CONTINUE THROUGH THE REST OF THE PERIOD.
A FRONT MAY SPARK A FEW SHOWERS AND/OR STORMS MONDAY AND TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1222 AM CDT WED SEP 10 2014
A COLD FRONT WILL CONTINUE TO SLIP SOUTH ACROSS WESTERN KANSAS
THROUGH THE EARLY MORNING HOURS. MVFR TO IFR STRATUS CURRENTLY OVER
SOUTHERN NEBRASKA IS EXPECTED TO CONTINUE BUILDING SOUTH THROUGH
THE EARLY MORNING HOURS AND SHOULD MOVE INTO THE TAF SITES BY
AROUND 10-12Z. THE STRATUS SHOULD LAST THROUGH MUCH OF THE MORNING
BEFORE LIFTING AT GARDEN CITY AND DODGE CITY BY EARLY AFTERNOON.
THE HAYS AREA MAY SEE AT LEAST MVFR CEILINGS THROUGH THE PERIOD.
VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE FORECAST
PERIOD AT GARDEN CITY AND DODGE CITY ALTHOUGH THERE IS SOME
POTENTIAL FOR LOW CEILINGS TO REDEVELOP AT THOSE SITES BY THE END
OF THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 73 51 70 45 / 20 0 10 70
GCK 73 50 72 42 / 20 0 20 80
EHA 75 53 75 46 / 10 0 20 80
LBL 76 53 74 48 / 10 0 10 70
HYS 68 49 63 42 / 20 0 20 70
P28 78 55 74 51 / 10 0 10 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1222 AM CDT WED SEP 10 2014
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 204 PM CDT TUE SEP 9 2014
LATEST RAP 400MB POTENTIAL VORTICITY APPEARS TO HAVE A DECENT
HANDLE WITH AN UPPER LEVEL DISTURBANCE THAT WAS CROSSING THE
COLORADO ROCKIES AT 18Z. GIVEN THE 18Z VERIFICATION WILL STAY
CLOSE TO THE RAP ON TIMING OF THIS UPPER LEVEL FEATURE AS IT
CROSSES EASTERN COLORADO AND WESTERN KANSAS LATER THIS EVENING.
GIVEN LATE DAY INSTABILITY AND LOCATION OF LOW LEVEL FORCING AHEAD
OF THIS UPPER LEVEL TROUGH NEAR A SURFACE BOUNDARY THAT WILL
EXTEND FROM SOUTHEAST COLORADO INTO NORTH CENTRAL KANSAS THERE
WILL BE A CHANCE FOR SCATTERED THUNDERSTORMS LATE THIS AFTERNOON
ACROSS NORTH CENTRAL KANSAS AND PORTIONS OF WEST KANSAS. BASED ON
THE 21Z TUESDAY AND 00Z WEDNESDAY CAPE AND 0-6KM SHEAR FROM THE
NAM A FEW STORMS LATE TODAY MAY BE SEVERE WITH THE AREA MORE
FAVORABLE FOR HAIL GOLF BALL SIZE OR LARGER ALONG WITH WIND GUST
IN EXCESS OF 60 MPH WILL BE ALONG AND NORTH OF A DIGHTON AND
LARNED LINE.
THUNDERSTORMS WILL THEN INCREASE IN AREAL COVERAGE EARLY TONIGHT
AS THE UPPER LEVEL DISTURBANCE CROSSES THE CENTRAL HIGH PLAINS AND
A SURFACE BOUNDARY MOVES ACROSS SOUTHWEST KANSAS. THE AREA THAT
WILL BE MORE FAVORABLE FOR WIDESPREAD THUNDERSTORMS EARLY TONIGHT
WILL BE ALONG AND NORTH OF A 700MB +10C TO +13C BAROCLINIC ZONE.
GIVEN THE 12Z NAM AND 12Z GFS THIS FAVORABLE AREA WILL BE
NORTHEAST OF A SYRACUSE TO DODGE CITY THE PRATT LINE. ALSO GIVEN
THE HIGH PRECIPITABLE WATER VALUES PERIODS THERE WILL BE A CHANCE
FOR PERIODS OF HEAVY RAIN IN THIS AREA AS WELL.
BUFR SOUNDINGS INDICATING WINDS NEAR THE SURFACE BEHIND THE COLD
FRONT WILL RANGE FROM 20 TO 30 KNOTS AS THE LOWER LEVELS BEGIN TO
SATURATE. BY 12Z WEDNESDAY THE DEPTH OF THIS LOW LEVEL MOISTURE
APPROACHES 3000FT WHICH SUPPORTS INSERTING A SLIGHT CHANCE FOR
LIGHT DRIZZLE FOR SEVERAL HOURS EARLY WEDNESDAY MORNING. BY LATE
MORNING THIS LOW LEVEL MOISTURE WILL BEGIN TO ERODE FROM SOUTHWEST
NORTHEAST AND GIVEN SOME AFTERNOON SUNSHINE ACROSS SOUTHWEST AND
SOUTH CENTRAL KANSAS THE HIGHS ARE EXPECTED TO CLIMB BACK INTO THE
MID 70S BASED ON THE 00Z THURSDAY 850MB TEMPERATURES. FURTHER
NORTH, NEAR THE INTERSTATE 70 CORRIDOR THE CLOUDS AND 850MB
TEMPERATURES AT 00Z THURSDAY SUGGEST HIGHS ON IN THE UPPER 60S TO
NEAR 70.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 313 PM CDT TUE SEP 9 2014
THE TREND WILL BE FOR COOLER AND WETTER IN THE VERY EARLY PERIOD
OF THE LONG TERM FORECAST. THE PERIOD FROM WEDNESDAY INTO THE
BEGINNING OF THE WEEKEND WILL THEN BE FOLLOWED BY A MODERATE
REBOUND BACK TOWARD THE 80S BY THE MIDDLE OF NEXT WEEK.
ALL THREE MODELS, THE ECMWF, GFS AND NAM INDICATED PRECIPITATION
ALONG A STRONG FRONTOGENETIC ZONE ACROSS CENTRAL AND FAR WESTERN
KANSAS INTO SOUTHEAST COLORADO FROM LATE THURSDAY NIGHT AND
SPREADING EAST OVER CENTRAL KANSAS FRIDAY MORNING. SOME VARIABILITY
IS EXPECTED AS THE BETTER FORCING IN THE MID LEVELS IS NOT EXPECTED
TO SLIDE ALL THE WAY THROUGH THE CWA INTO OKLAHOMA, HENCE A BAND OF
HIGHER RAIN AMOUNTS COULD FALL SOMEWHERE FROM THE HIGHWAY 54
CORRIDOR NORTHWARD AS THE NAM SUGGESTS. OTHER LOCATIONS SHOULD STILL
GET SOME, BUT GENERALLY MUCH LIGHTER PRECIPITATION AMOUNTS OF A FEW
HUNDREDTHS AS THE SECONDARY FRONTAL BOUNDARY MOVES THROUGH THE
REGION IN THE FORM OF SCATTERED SHOWERS IF NOT A PERIOD OF RAIN. OF
MUCH LONGER DURATION AND IMPACT WILL BE THE WIDESPREAD STRATUS
THROUGH THE AREA, INHIBITING INSOLATION AND ENHANCING COLD
ADVECTION. THE NUMEROUS MODELS AND BLEND SOLUTIONS STRONGLY SUPPORTS
LOW 50S ACROSS MUCH OF THE AREA FOR A HIGH TEMPERATURES ON FRIDAY.
TEMPERATURES THIS COOL WILL REPRESENT ONLY A FEW DEGREES ABOVE
RECORD MIN-MAXIMUM TEMPERATURES FOR SEPTEMBER 12TH AT LEAST
LOCALLY AT DDC.
A WARMING TEND WILL BE SLOW THROUGH THE WEEKEND PERIOD. THE MEAN
LAYER WILL RETURN TO GENERALLY ZONAL PATTERN BY SUNDAY AFTER THE
LARGE WAVE EXISTS. THE NEXT WAVE WILL NOT BECOME A POTENTIAL IMPACT
UNTIL AROUND LATE SUNDAY OR MONDAY. THE PATTERN SUGGEST SOUTHWEST
KANSAS COULD BE SPLIT AS FAR AS UPPER DYNAMIC FORCING GOES, WITH
POSSIBLE MCS ACTIVITY TO THE NORTH IN THE DAKOTA`S AND NEBRASKA
AND SHORTWAVE ENERGY IN THE PANHANDLES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1222 AM CDT WED SEP 10 2014
A COLD FRONT WILL CONTINUE TO SLIP SOUTH ACROSS WESTERN KANSAS
THROUGH THE EARLY MORNING HOURS. MVFR TO IFR STRATUS CURRENTLY OVER
SOUTHERN NEBRASKA IS EXPECTED TO CONTINUE BUILDING SOUTH THROUGH
THE EARLY MORNING HOURS AND SHOULD MOVE INTO THE TAF SITES BY
AROUND 10-12Z. THE STRATUS SHOULD LAST THROUGH MUCH OF THE MORNING
BEFORE LIFTING AT GARDEN CITY AND DODGE CITY BY EARLY AFTERNOON.
THE HAYS AREA MAY SEE AT LEAST MVFR CEILINGS THROUGH THE PERIOD.
VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE FORECAST
PERIOD AT GARDEN CITY AND DODGE CITY ALTHOUGH THERE IS SOME
POTENTIAL FOR LOW CEILINGS TO REDEVELOP AT THOSE SITES BY THE END
OF THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 49 65 45 53 / 0 10 60 60
GCK 49 63 43 52 / 10 10 80 70
EHA 52 69 44 54 / 10 10 80 70
LBL 51 67 47 55 / 0 10 80 70
HYS 45 62 43 53 / 0 10 50 60
P28 53 71 54 59 / 0 10 40 70
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURGERT
LONG TERM...RUSSELL
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
602 AM EDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EDT WED SEP 10 2014
LIGHT TO AT TIME HEAVY RAIN CONTINUES TO FALL OVER THE W THIRD OF
UPPER MI THIS MORNING...ASSOCIATED WITH THE SFC TROUGH THAT PUSHED
OVERHEAD EARLY THIS MORNING THE 500MB SHORTWAVE CROSSING WI...AND
THE DEEPENING SFC LOW RIDING UP ALONG THE TROUGH NEARING FROM IA.
THE LATEST SATELLITE AND RUC ANALYSIS SHOWS THIS INITIAL N SWATH OF
MOISTURE EJECTING NE ACROSS THE CWA...WITH THE EFFECTS OF THE SW TO
NE 100KT 250MB JET NEARING FROM THE PLAINS. THE SECONDARY AREA OF
CLOUDS WILL BE IMPACTING THE E HALF OF THE CWA LATER THIS MORNING
AND INTO THE AFTERNOON HOURS. EXACT RAINFALL TOTALS REMAIN TRICKY AS
THERE ARE 2 AREAS OF THOUGHT. THE LATEST 06Z NAM PAINTS AN
ADDITIONAL 1-2IN OVER CENTRAL AND E UPPER MI LATE THIS MORNING
THROUGH EARLY THIS AFTERNOON. HOWEVER...THE 00Z GFS IS PUSHING MUCH
OF THE MOISTURE JUST TO OUR E. HAVE GONE WITH A MIDDLE OF THE ROAD
SOLUTION FOR THE MOMENT...KNOWING THAT CONVECTION TO THE SOUTH COULD
STILL HURT THE INFLOW OF MOISTURE UP OUR WAY. STILL...ADDITIONAL
SHOWERS CROSSING THE CWA THIS AFTERNOON WITH BE FACED WITH STIFF N
ONSHORE FLOW...RESULTING IN A SLOWER N PROGRESSION AND OVERALL
UPSLOPE ENHANCEMENT. SEE THE HYDROLOGY SECTION FOR MORE DETAILS
ABOUT PRECIPITATION FOR THE REST OF TODAY. RAIN/RAIN SHOWERS WILL
CONTINUE THROUGH TONIGHT...MAINLY ACROSS THOSE UPSLOPE AREAS OF
CENTRAL UPPER MI. ADDITIONAL RAINFALL MAY ADD UP TO 0.25IN OR MORE
ACROSS THE HURON MOUNTAINS. FCST MODELS ARE CONTINUING TO GO WITH
THE SFC LOW TRACKING ACROSS N LOWER MI LATE THIS AFTERNOON...BEFORE
EXITING INTO S ONTARIO AND W QUEBEC LATE THIS EVENING.
TEMPERATURES WILL REMAIN TRICKY...AS THEY FALL W AND STILL RISE A
COUPLE OF DEGREES AFTER SUNRISE E. KEPT THE WIND FCST VERY SIMILAR
TO THE LAST COUPLE OF DAYS...WITH N-NNW GUSTS NEARING 35KTS FROM
AROUND 18Z TODAY TO 08Z TONIGHT. AN SPS MAY BE NEEDED FOR THE W HALF
AND HIGHER TERRAIN OF THE KEWEENAW PENINSULA...OR LOW END WIND
ADVISORY TO HIGHLIGHT THE STRONG WINDS ON TOP OF SATURATED SOILS
THAT MAY MORE EASILY UPROOT TREES THANKS TO THE ABUNDANT LEAVES. AS
FOR THE OVERNIGHT HOURS...EXPECT SLOWLY DIMINISHING WINDS LATE AND
COLD AIR TO FILTER IN WITH 850MB TEMPS OF -2 TO +4C BY DAYBREAK
THURSDAY. DEPENDING ON HOW FAST RAIN CAN GET OUT OF THE INTERIOR
AREAS ALONG THE WI BORDER...MID 30S LOWS WILL NOT BE OUT OF THE
QUESTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 603 AM EDT WED SEP 10 2014
OFF AND ON RAIN AND BR/FG HAVE BEEN THE TREND OVERNIGHT. ONCE THE
RAIN HAS ENDED IFR TO VLIFR CEILINGS HAVE DEVELOPED. INCREASING
WINDS THIS MORNING SHOULD HELP LIMITED THE BR. HOWEVER...LOW
CEILINGS WILL STILL BE POSSIBLE WITH ANY MODERATE RAIN THAT DEVELOPS.
LOOKING AT UPSTREAM CONDITIONS...LIFR CEILINGS WILL LIKELY DOMINATE
THE DAY AT IWD AND CMX. STEADIER RAIN WILL MOVE INTO SAW OVER THE
NEXT FEW HOURS. LOOK FOR STRONG WINDS DEVELOPING W TO E THIS
MORNING...WITH GUSTS OVER 30KTS POSSIBLE AT CMX FROM 19Z THIS
AFTERNOON TO 04Z THURSDAY. IWD MAY BE LIMITED TO GUSTS AROUND
20KTS...WHILE THE N WINDS GUST BETWEEN 25 AND 30KTS FROM 21Z TO 09Z
THURSDAY AT SAW AND KEEP LAKE EFFECT/ENHANCED RAIN SHOWERS GOING
THROUGH 12Z THURSDAY. DRIER AIR WILL SLOWLY WORK IN FROM THE
W...WITH ONLY A CHANCE OF SHOWERS AT CMX AND IWD BY DAYBREAK
THURSDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH THROUGH THIS EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...KF
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
534 AM EDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EDT WED SEP 10 2014
LIGHT TO AT TIME HEAVY RAIN CONTINUES TO FALL OVER THE W THIRD OF
UPPER MI THIS MORNING...ASSOCIATED WITH THE SFC TROUGH THAT PUSHED
OVERHEAD EARLY THIS MORNING THE 500MB SHORTWAVE CROSSING WI...AND
THE DEEPENING SFC LOW RIDING UP ALONG THE TROUGH NEARING FROM IA.
THE LATEST SATELLITE AND RUC ANALYSIS SHOWS THIS INITIAL N SWATH OF
MOISTURE EJECTING NE ACROSS THE CWA...WITH THE EFFECTS OF THE SW TO
NE 100KT 250MB JET NEARING FROM THE PLAINS. THE SECONDARY AREA OF
CLOUDS WILL BE IMPACTING THE E HALF OF THE CWA LATER THIS MORNING
AND INTO THE AFTERNOON HOURS. EXACT RAINFALL TOTALS REMAIN TRICKY AS
THERE ARE 2 AREAS OF THOUGHT. THE LATEST 06Z NAM PAINTS AN
ADDITIONAL 1-2IN OVER CENTRAL AND E UPPER MI LATE THIS MORNING
THROUGH EARLY THIS AFTERNOON. HOWEVER...THE 00Z GFS IS PUSHING MUCH
OF THE MOISTURE JUST TO OUR E. HAVE GONE WITH A MIDDLE OF THE ROAD
SOLUTION FOR THE MOMENT...KNOWING THAT CONVECTION TO THE SOUTH COULD
STILL HURT THE INFLOW OF MOISTURE UP OUR WAY. STILL...ADDITIONAL
SHOWERS CROSSING THE CWA THIS AFTERNOON WITH BE FACED WITH STIFF N
ONSHORE FLOW...RESULTING IN A SLOWER N PROGRESSION AND OVERALL
UPSLOPE ENHANCEMENT. SEE THE HYDROLOGY SECTION FOR MORE DETAILS
ABOUT PRECIPITATION FOR THE REST OF TODAY. RAIN/RAIN SHOWERS WILL
CONTINUE THROUGH TONIGHT...MAINLY ACROSS THOSE UPSLOPE AREAS OF
CENTRAL UPPER MI. ADDITIONAL RAINFALL MAY ADD UP TO 0.25IN OR MORE
ACROSS THE HURON MOUNTAINS. FCST MODELS ARE CONTINUING TO GO WITH
THE SFC LOW TRACKING ACROSS N LOWER MI LATE THIS AFTERNOON...BEFORE
EXITING INTO S ONTARIO AND W QUEBEC LATE THIS EVENING.
TEMPERATURES WILL REMAIN TRICKY...AS THEY FALL W AND STILL RISE A
COUPLE OF DEGREES AFTER SUNRISE E. KEPT THE WIND FCST VERY SIMILAR
TO THE LAST COUPLE OF DAYS...WITH N-NNW GUSTS NEARING 35KTS FROM
AROUND 18Z TODAY TO 08Z TONIGHT. AN SPS MAY BE NEEDED FOR THE W HALF
AND HIGHER TERRAIN OF THE KEWEENAW PENINSULA...OR LOW END WIND
ADVISORY TO HIGHLIGHT THE STRONG WINDS ON TOP OF SATURATED SOILS
THAT MAY MORE EASILY UPROOT TREES THANKS TO THE ABUNDANT LEAVES. AS
FOR THE OVERNIGHT HOURS...EXPECT SLOWLY DIMINISHING WINDS LATE AND
COLD AIR TO FILTER IN WITH 850MB TEMPS OF -2 TO +4C BY DAYBREAK
THURSDAY. DEPENDING ON HOW FAST RAIN CAN GET OUT OF THE INTERIOR
AREAS ALONG THE WI BORDER...MID 30S LOWS WILL NOT BE OUT OF THE
QUESTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM EDT TUE SEP 9 2014
NNE WIND SHIFT BEHIND A COLD FRONT MOVED BROUGHT LIFR CLOUDS INTO
IWD/CMX LAST EVENING. A FEW SHRA/TSRA HAVE ALSO POPPED UP ALONG
FRONTAL BOUNDARY MAINLY AT IWD. AS A STRONGER DISTURBANCE MOVES NEWD
AND THE MOIST LYR DEEPENS...WIDESPREAD RAIN WILL DEVELOP FROM SW TO
NE AND KEEPING CONDITIONS LIFR AT IWD/CMX INTO MUCH OF WED. SINCE
THE FROPA WL OCCUR LATER AT SAW...THE TRANSITION TO MVFR WILL NOT
OCCUR UNTIL AROUND 08Z. BY LATE TONIGHT INTO WED MORNING LIFR
CONDITIONS WILL PREVAIL AT SAW AS WELL WITH MODERATE TO OCNLY HEAVY
RAIN AND GUSTY NE-N WINDS DEVELOPING BY LATE MORNING/AFTERNOON. NE-N
WIND WILL GUST OVER 30 KT AT KCMX AND POSSIBLY AOA 25 KTS AT KSAW
AND IWD BY LATE MORNING/MIDDAY WED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH THROUGH THIS EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KF
LONG TERM...KC
AVIATION...VOSS
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 AM EDT WED SEP 10 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 344 PM EDT TUE SEP 9 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
DEVELOPING MID/UPPER LEVEL TROUGH OVER THE WRN CONUS. THE TAIL OF AN
ELONGATED SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WAS DRAGGING A
COLD FRONT SLOWLY SOUTH INTO WRN LAKE SUPERIOR. A VIGOROUS SRN
STREAM SHRTWV MOVING IN THE CNTRL PLAINS WILL SUPPORT DEVELOPMENT OF
A SFC LOW THAT WILL MOVE INTO THE WRN LAKES WED. EVEN WITH LAKE
BREEZE ONSHORE WINDS INTO WRN UPPER MI...LOW LEVEL CONV HAS NOT BEEN
STRONG ENOUGH TO OVERCOME CAPPING WITH 800-750 MB TEMPS NEAR
12C...PER RUC. OTHERWISE...ABUNDANT CU PREVAILED ACROSS THE WEST
HALF OF UPPER MI WHILE MORE STABLE AIR OFF OF LAKE MI HAS KEPT SKIES
MOSTLY CLEAR OVER THE EAST.
THE POTENTIAL REMAINS FOR SOME SHRA/TSRA THIS EVENING AS THE FRONTAL
BOUNDARY MOVES THROUGH WRN UPPER MI. HOWEVER...COVERAGE SHOULD
LIMITED WITH ONLY LOWER END CHANCE POPS GIVEN THE STRENGTH OF THE
CAPPING.
AS THE PLAINS SHRTWV MOVES TOWARD THE AREA AND THE SFC LOW
DEEPENS...300-310 ISENTROPIC ASCENT ALONG WITH 800-600 MB FGEN WILL
STRENGTHEN AND SUPPORT AN EXPANDING AREA OF MODERATE TO HEAVY RAIN
FROM NW/N WI INTO WRN UPPER MI BY LATE EVENING AND INTO CNTRL UPPER
MI LATE TONIGHT. STRONG MID/UPPER LEVEL DYNAMICS WITH A COUPLED
UPPER LEVEL JET STRUCTURE AND STRONG QVECTOR CONV WILL SUPPORT A
LARGE AREA OF RAIN ACROSS THE CWA WED. SOME MODEL UNCERTAINTY
REMAINS AS THE NAM REMAINS MUCH DEEPER AND FARTHER TO THE NW THAN
MODELS CONSENSUS AND THE GFS FASTER AND ALONG THE SOUTHERN ENVELOPE
OF MODEL SPREAD. FAVORED THE MORE CONSISTENT ECMWF AND REGIONAL GEM
WITH THE LOW PATH TO NEAR GRB BY 18Z AND THE STRAITS BY 00Z/THU.
VERY STRONG 850 MB MOISTURE INFLOW...UPPER LEVEL AND 800-600 MB FGEN
EVEN WITHOUT TSRA WILL BRING THE POTENTIAL FOR A PERIOD OF HEAVY
RAIN...ESPECIALLY BTWN 09Z-18Z. UNCERTAINTY REMAINS ON THE IMPACT OF
UPSTREAM CONVECTION OVER IA INTO SRN WI ON THE EVOLUTION OF THE
850-700 MB FRONTAL BOUNDARY AND MOISTURE INFLOW TO THE NORTH.
HOWEVER...THE POTENTIAL REMAINS FOR QPF IN THE 1.5 INCH TO 2.0 INCH
RANGE...WITH LOCALLY HIGHER AMOUNTS AOA 3 INCHES. SO THE FLOOD WATCH
WILL REMAINS IN EFFECT.
NE WINDS VEERING TO THE NNE WILL ALSO INCREASE WITH GUSTS LIKELY IN
INTO THE 40-50 KNOT RANGE BY TO LATE AFTERNOON OVER THE
KEWEENAW...ESPECIALLY FOR LOCATIONS FAVORED BY NNE FLOW SUCH AS
COPPER HARBOR. AN ADVISORY WILL LIKELY BE NEEDED.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM EDT TUE SEP 9 2014
NNE WIND SHIFT BEHIND A COLD FRONT MOVED BROUGHT LIFR CLOUDS INTO
IWD/CMX LAST EVENING. A FEW SHRA/TSRA HAVE ALSO POPPED UP ALONG
FRONTAL BOUNDARY MAINLY AT IWD. AS A STRONGER DISTURBANCE MOVES NEWD
AND THE MOIST LYR DEEPENS...WIDESPREAD RAIN WILL DEVELOP FROM SW TO
NE AND KEEPING CONDITIONS LIFR AT IWD/CMX INTO MUCH OF WED. SINCE
THE FROPA WL OCCUR LATER AT SAW...THE TRANSITION TO MVFR WILL NOT
OCCUR UNTIL AROUND 08Z. BY LATE TONIGHT INTO WED MORNING LIFR
CONDITIONS WILL PREVAIL AT SAW AS WELL WITH MODERATE TO OCNLY HEAVY
RAIN AND GUSTY NE-N WINDS DEVELOPING BY LATE MORNING/AFTERNOON. NE-N
WIND WILL GUST OVER 30 KT AT KCMX AND POSSIBLY AOA 25 KTS AT KSAW
AND IWD BY LATE MORNING/MIDDAY WED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT. &&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH THROUGH THIS EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...VOSS
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
405 AM EDT WED SEP 10 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 344 PM EDT TUE SEP 9 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A SPLIT FLOW PATTERN WITH A
DEVELOPING MID/UPPER LEVEL TROUGH OVER THE WRN CONUS. THE TAIL OF AN
ELONGATED SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO WAS DRAGGING A
COLD FRONT SLOWLY SOUTH INTO WRN LAKE SUPERIOR. A VIGOROUS SRN
STREAM SHRTWV MOVING IN THE CNTRL PLAINS WILL SUPPORT DEVELOPMENT OF
A SFC LOW THAT WILL MOVE INTO THE WRN LAKES WED. EVEN WITH LAKE
BREEZE ONSHORE WINDS INTO WRN UPPER MI...LOW LEVEL CONV HAS NOT BEEN
STRONG ENOUGH TO OVERCOME CAPPING WITH 800-750 MB TEMPS NEAR
12C...PER RUC. OTHERWISE...ABUNDANT CU PREVAILED ACROSS THE WEST
HALF OF UPPER MI WHILE MORE STABLE AIR OFF OF LAKE MI HAS KEPT SKIES
MOSTLY CLEAR OVER THE EAST.
THE POTENTIAL REMAINS FOR SOME SHRA/TSRA THIS EVENING AS THE FRONTAL
BOUNDARY MOVES THROUGH WRN UPPER MI. HOWEVER...COVERAGE SHOULD
LIMITED WITH ONLY LOWER END CHANCE POPS GIVEN THE STRENGTH OF THE
CAPPING.
AS THE PLAINS SHRTWV MOVES TOWARD THE AREA AND THE SFC LOW
DEEPENS...300-310 ISENTROPIC ASCENT ALONG WITH 800-600 MB FGEN WILL
STRENGTHEN AND SUPPORT AN EXPANDING AREA OF MODERATE TO HEAVY RAIN
FROM NW/N WI INTO WRN UPPER MI BY LATE EVENING AND INTO CNTRL UPPER
MI LATE TONIGHT. STRONG MID/UPPER LEVEL DYNAMICS WITH A COUPLED
UPPER LEVEL JET STRUCTURE AND STRONG QVECTOR CONV WILL SUPPORT A
LARGE AREA OF RAIN ACROSS THE CWA WED. SOME MODEL UNCERTAINTY
REMAINS AS THE NAM REMAINS MUCH DEEPER AND FARTHER TO THE NW THAN
MODELS CONSENSUS AND THE GFS FASTER AND ALONG THE SOUTHERN ENVELOPE
OF MODEL SPREAD. FAVORED THE MORE CONSISTENT ECMWF AND REGIONAL GEM
WITH THE LOW PATH TO NEAR GRB BY 18Z AND THE STRAITS BY 00Z/THU.
VERY STRONG 850 MB MOISTURE INFLOW...UPPER LEVEL AND 800-600 MB FGEN
EVEN WITHOUT TSRA WILL BRING THE POTENTIAL FOR A PERIOD OF HEAVY
RAIN...ESPECIALLY BTWN 09Z-18Z. UNCERTAINTY REMAINS ON THE IMPACT OF
UPSTREAM CONVECTION OVER IA INTO SRN WI ON THE EVOLUTION OF THE
850-700 MB FRONTAL BOUNDARY AND MOISTURE INFLOW TO THE NORTH.
HOWEVER...THE POTENTIAL REMAINS FOR QPF IN THE 1.5 INCH TO 2.0 INCH
RANGE...WITH LOCALLY HIGHER AMOUNTS AOA 3 INCHES. SO THE FLOOD WATCH
WILL REMAINS IN EFFECT.
NE WINDS VEERING TO THE NNE WILL ALSO INCREASE WITH GUSTS LIKELY IN
INTO THE 40-50 KNOT RANGE BY TO LATE AFTERNOON OVER THE
KEWEENAW...ESPECIALLY FOR LOCATIONS FAVORED BY NNE FLOW SUCH AS
COPPER HARBOR. AN ADVISORY WILL LIKELY BE NEEDED.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM EDT TUE SEP 9 2014
NNE WIND SHIFT BEHIND A COLD FRONT MOVED BROUGHT LIFR CLOUDS INTO
IWD/CMX LAST EVENING. A FEW SHRA/TSRA HAVE ALSO POPPED UP ALONG
FRONTAL BOUNDARY MAINLY AT IWD. AS A STRONGER DISTURBANCE MOVES NEWD
AND THE MOIST LYR DEEPENS...WIDESPREAD RAIN WILL DEVELOP FROM SW TO
NE AND KEEPING CONDITIONS LIFR AT IWD/CMX INTO MUCH OF WED. SINCE
THE FROPA WL OCCUR LATER AT SAW...THE TRANSITION TO MVFR WILL NOT
OCCUR UNTIL AROUND 08Z. BY LATE TONIGHT INTO WED MORNING LIFR
CONDITIONS WILL PREVAIL AT SAW AS WELL WITH MODERATE TO OCNLY HEAVY
RAIN AND GUSTY NE-N WINDS DEVELOPING BY LATE MORNING/AFTERNOON. NE-N
WIND WILL GUST OVER 30 KT AT KCMX AND POSSIBLY AOA 25 KTS AT KSAW
AND IWD BY LATE MORNING/MIDDAY WED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND
ACROSS NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE
SUPERIOR FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS
IN THE MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 344 PM EDT TUE SEP 9 2014
RAINFALL TOTALS FROM TONIGHT THROUGH WEDNESDAY NIGHT ACROSS UPPER MI
RANGE FROM JUST OVER 1.5 TO LOCALLY 3 INCHES. UNCERTAINTY REMAINS
WHERE THE HEAVIER BANDS OF RAIN WILL DEVELOP. HIGHER TOTALS INTO WED
NIGHT ARE EXPECTED FOR LOCATIONS IN N CNTRL UPPER MI WHERE STRONG
UPSLOPE FLOW WILL BOOST RAINFALL AMOUNTS. THE FLOOD WATCH REMAINS
POSTED FOR MUCH OF W AND CENTRAL UPPER MI.
EXPECT THE TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A
SIGNIFICANT POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF
A PERIOD OF HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO
AN 0.5-1.0 INCH PER HOUR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH THROUGH THIS EVENING FOR MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 5 AM EDT THURSDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...VOSS
MARINE...KC
HYDROLOGY...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
326 AM CDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT WED SEP 10 2014
MODERATE TO HEAVY RAIN CONTINUES OVER MUCH OF EAST CENTRAL MN AND
WEST CENTRAL WISCONSIN. ALTHOUGH THE GREATER MOISTURE TRANSPORT HAS
EXITED TO THE SOUTHEAST OF THE AREA...FAIRLY STRONG MID LEVEL
FRONTOGENESIS REMAINS OVER TWO SPECIFIC AREAS OF THE CWA. ONE OVER
EAST CENTRAL MN AND NORTHWEST WISCONSIN AND THE OTHER DEVELOPING TO
THE SOUTHEAST...MOVING NOW INTO WEST CENTRAL WISCONSIN. THE RUC AND
NAM SHOW THIS GRADUALLY WEAKENING AND LIFTING OFF TO THE EAST
DURING THE MORNING. THIS SHOULD TAKE THE RAIN WITH IT. THE THREAT
OF PONDING WATER REMAINS MAINLY ACROSS WEST CENTRAL WISCONSIN INTO
THE MORNING. COLLABORATION WITH SURROUNDING OFFICES DID YIELD THE
CONTINUATION OF THE FLOOD WATCH INTO WEST CENTRAL WISCONSIN.
TODAYS HIGH TEMPERATURES WILL LIKELY OCCUR THIS MORNING AS WELL.
THEY MAY CONTINUE TO DROP OFF THROUGH MID MORNING OR SO BEFORE
LEVELING OFF INTO THE AFTERNOON. STRONG NORTH WINDS RE EXPECTED TO
DEVELOP EAST AS LOW LEVEL CAA SPREADS OVER THE REGION.
CLOUDS ARE EXPECTED TO HANG TOUGH OVER MUCH OF THE AREA INTO THE
NIGHT. THERE IS SOME INDICATION THAT IN THE WAKE OF THE
TROUGH...SUBSIDENCE COULD BE STRONG ENOUGH TO ERODE THE LOWER CLOUD
COVER. WINDS WILL SLOWLY DIMINISH AS THE LOW CONTINUE TO LIFT
EAST/NORTHEAST INTO THE NIGHT. IT SHOULD COOL RAPIDLY IF BREAKS DO
DEVELOP INTO THE NORTH CENTRAL CWA DURING THE NIGHT. SOME UPPER 30S
POSSIBLE WHERE THIS OCCURS. READINGS IN THE LOWER 40S SHOULD REMAIN
ELSEWHERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 327 AM CDT WED SEP 10 2014
THE LONG TERM FORECAST WILL FEATURE THE PASSAGE OF A SHORTWAVE
TROUGH AT THE BEGINNING OF THE PERIOD...FOLLOWED BY BRIEF SEMI-
ZONAL FLOW OVER THE WEEKEND...AND THEN A PATTERN TRANSITION TO
WESTERN RIDGING AND EASTERN TROUGHING THROUGH THE FIRST HALF OF
NEXT WEEK.
ON THURSDAY...A BROAD SURFACE HIGH BECOMES ESTABLISHED ACROSS THE
NATION/S MIDSECTION...WHILE A WEAK SHORTWAVE SLIDES EAST/SOUTHEAST
ACROSS THE AREA FROM THE NORTHERN/CANADIAN ROCKIES. WHILE THE
BETTER FORCING AND MORE PLENTIFUL MOISTURE WILL LIE SOUTH OF THE
FORECAST AREA...COULD SEE A FEW SHOWERS SNEAK INTO SOUTHERN MN AND
WEST CENTRAL WI LATE THURSDAY NIGHT AND FRIDAY. TEMPERATURES WILL
BE COOL...WITH HIGHS IN THE 50S ON THURSDAY AND FRIDAY...AND LOWS
DIPPING INTO THE MID TO UPPER 30S. DEPENDING ON HOW THE CLEARING
GOES AND WINDS...COULD POSSIBLY SEE SOME FROST ON SATURDAY
MORNING.
SATURDAY LOOKS TO HAVE THE HIGHEST POTENTIAL TO BE AN ENTIRELY DRY
DAY...AS SURFACE HIGH PRESSURE PREVAILS AND IN THE ABSENCE OF ANY
MID/UPPER DISTURBANCES.
SUNDAY BRINGS THE ARRIVAL OF WEAK SHORTWAVE ENERGY IN THE BASE OF
THE MANITOBA/ONTARIO TROUGH. MOISTURE AND FORCING ARE THE MOST
ROBUST NORTH AND EAST OF THE FORECAST AREA...BUT SUFFICIENT TO
WARRANT 20 POPS LOCALLY.
ON MONDAY...THINGS START TO DRY OUT WITH THE PATTERN EVOLUTION TO
WESTERN RIDGING. OVERALL...SHOULD BE DRY WITH SLIGHTLY BELOW
NORMAL TEMPERATURES THROUGH MID-WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1037 PM CDT TUE SEP 9 2014
CONDITIONS TO CONTINUE DETERIORATING THRU THE OVERNIGHT HOURS AS
A STORM SYSTEM MOVING NE FROM THE CENTRAL PLAINS INTO THE GREAT
LAKES WILL SPREAD RAIN ACROSS THE ENTIRE REGION BY THE EARLY
MORNING HOURS. CONDITIONS WILL LIKELY HIT IFR AT ALL
TERMINALS...WITH LIFR CERTAINLY POSSIBLE...FOR BOTH CEILINGS AND
VSBY. CONDITIONS WILL REMAIN DEGRADED THRU THE OVERNIGHT HOURS
WITH RAINFALL GRADUALLY ENDING FROM W TO E BY LATE MORNING.
CEILINGS WILL SLOWLY LIFT DURG THE DAY WED AND MAY REACH VFR
LEVELS BY WED EVE. WINDS WILL REMAIN BREEZY/GUSTY OVERNIGHT AS
THEY SWING FROM E-SE TO NE-N...THEN SETTLING ON N FOR MUCH OF THE
DAY WED BEFORE SPEEDS DIMINISH WED EVE. HAVE KEPT TSTM MENTION AT
A MINIMAL...IF AT ALL...DUE TO LOW CONFIDENCE IN PINPOINTING
LOCATION/TIMING.
KMSP...MVFR CONDS TO START THE 10/06Z TAFS WITH CONDS CONTINUING
TO DEGRADE THRU THE EARLY MRNG HOURS. CIGS LIKELY TO HIT IFR
LEVELS SHORTLY AFTER MIDNIGHT AND ARE EXPECTED TO REMAIN BELOW
1000 FT THRU LATE WED MRNG. RAIN WILL BE HEAVIEST OVERNIGHT BUT
LOOKS TO BECOME LIGHT BY THE MORNING PUSH...EVENTUALLY ENDING BY
MIDDAY. THAT SAID...CEILINGS LOOK TO REMAIN BELOW 1700 FT FOR MUCH
IF NOT THE ENTIRE DAY WED.
/OUTLOOK FOR KMSP/
WED...MVFR THEN VFR LATE. WINDS NNW AT 20G25KTS.
THU...VFR. WINDS NW AT 10G15KTS.
FRI...VFR. WINDS NW AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR WIZ015-016-
023>028.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
255 AM MDT WED SEP 10 2014
.SHORT TERM...VALID FOR TDY AND THU...
MAIN FORECAST ISSUE REVOLVES AROUND POTENTIAL EARLY SEASON SNOW
EVENT TONIGHT AND THURSDAY.
DYNAMIC UPPER LOW DROPPING ALONG THE SPINE OF THE CANADIAN
ROCKIES...WITH AN IMPRESSIVE 120KT H3 NWLY JET ANALYZED IN CENTRAL
BRITISH COLUMBIA. CLOUD TOPS IN STRONGLY DIFFLUENT REGION OF THIS
LOW HAVE BEEN COOLING RAPIDLY TONIGHT WITH TOPS TO -45C AT 08Z.
LATEST OBS TO OUR NORTH SHOW SNOW ALONG THE EASTERN SLOPES OF THE
CANADIAN ROCKIES FROM CALGARY TO EDSON. LATEST MODELS AND EVEN THE
07Z RAP SHOW THE JET NOSING TOWARD SOUTH CENTRAL MT BY THIS
EVENING...LEAVING US IN A FAVORABLE POSITION FOR UPPER DIVERGENCE.
ALL MODELS HAVE BEEN CONSISTENTLY SHOWING STRONG Q-VECTOR
CONVERGENCE OVER OUR CWA TONIGHT THRU MUCH OF THURSDAY. ASCENT
WILL NOT BE AN ISSUE WITH THIS SYSTEM...BUT AREA OF FRONTOGENESIS
AND UPSLOPE FLOW WILL DICTATE WHERE THE HEAVIEST PCPN WILL BE.
CONFIDENCE CONTINUES TO INCREASE FOR AN UPSLOPE EVENT
MATERIALIZING BY THIS EVENING AND LASTING THROUGH MUCH OF
THURSDAY. LATEST OBSERVATIONS TO OUR NORTH HELP TO GIVE CREDENCE
TO THIS SCENARIO. IT ALSO SHOULD BE NOTED THAT MID LEVEL LAPSE
RATES ON THE ORDER OF 6-7 C/KM OVER OUR WEST SUGGEST A CONVECTIVE
COMPONENT OF THE PCPN TONIGHT THROUGH THURSDAY.
PCPN CHANCES WILL BE INCREASING TODAY WITH ISENTROPIC ASCENT AND
DIFFLUENCE ALOFT AND LATEST REGIONAL RADAR SHOWS SHOWERS SPREADING
IN FROM THE NORTH. AREAS OF FOG/DRIZZLE ALSO EXIST PER THE LOW
LEVEL SATURATED LAYER WITH UPSLOPE WINDS. TEMPS ACROSS OUR CWA
WILL SUPPORT A CHILLY RAIN WITH THE EXCEPTION OF THE HIGH COUNTRY.
BY 00Z...SECONDARY PUSH OF COLD ADVECTION WILL KICK IN SO EXPECT
SNOW LEVELS TO FALL SIGNIFICANTLY BY THIS EVENING.
HAVE ISSUED A WINTER WX ADVISORY FOR OUR NW PARTS...SPECIFICALLY
FROM THE EAST SIDE OF THE CRAZY MTNS THROUGH JUDITH GAP...PER A
PERIOD OF DEEP EAST FLOW AS THE UPPER TROF MOVES IN AND AN
EXPECTED TRANSITION TO SNOW BY THIS EVENING. WOULD EXPECT THE
BEARTOOTH AND RED LODGE FOOTHILLS TO SEE UPSLOPE SNOWFALL
BEGINNING SOMETIME THIS EVENING ALSO. HAVE ISSUED A WINTER STORM
WARNING FOR THE FOOTHILLS AND ALSO THE NORTH/EAST SLOPES OF THE
BEARTOOTH...ABSAROKA AND CRAZY MTNS. FOR ALL OF THESE
HIGHLIGHTS THE SNOW AMTS WILL VARY PER ELEVATION BUT THE BIGGEST
IMPACT WILL BE THE POTENTIAL FOR DOWNED TREES AND POWER LINES.
ANYONE PLANNING TRIPS TO THE HIGH COUNTRY WILL ALSO BE IMPACTED
INCLUDING BEARTOOTH PASS. MODELS CONTINUE TO SUGGEST BETWEEN A
HALF INCH AND INCH OF PCPN DURING TIME OF PEAK ASCENT...SO SEVERAL
INCHES OF SNOWFALL COULD OCCUR IN THESE UPSLOPE AREAS. TURNING TO
THE BIG HORNS AND SHERIDAN COUNTY...THOUGH THE MTNS WILL SEE A
HEAVY SNOWFALL...TRANSITION TO SNOW WILL BE A BIT LATER FOR THE
CITY OF SHERIDAN...PERHAPS LATE EVENING OR INTO THE OVERNIGHT
HOURS. POTENTIAL STILL EXISTS FOR AN INCH OF WATER AND HEAVY
SNOWFALL ON THE EASTERN ASPECTS OF THE BIG HORNS. GIVEN SOME
UNCERTAINTY IN SFC TEMPS IN SHERIDAN WILL LET THE WATCH CONTINUE
AND HAVE THE DAY SHIFT MAKE THE FINAL CALL ON SPECIFIC
HIGHLIGHTS. OTHER LOCATIONS WHICH MAY BE IMPACTED INCLUDE THE
HIGHER HILLS ACROSS OUR SOUTHEAST FROM SOUTHERN BIG HORN TO POWDER
RIVER COUNTIES...SUCH PLACES AS THE WOLF MTNS AND LAME DEER
DIVIDE. WOULD EXPECT SOME SLUSHY ACCUMULATION IN THESE AREAS TOO
ESPECIALLY IF FRONTOGENESIS LINGERS A BIT NORTH OF THE FOOTHILLS
AS SOME MODELS SUGGEST. SYSTEM WILL WIND DOWN THURSDAY AFTERNOON
AND EVENING.
TEMPS TODAY AND WEDNESDAY WILL MAX OUT ONLY IN THE 40S...WITH SOME
RECORD COLD HIGH TEMPS BEING CHALLENGED. COLDEST NIGHT WILL BE
THURSDAY NIGHT AS 1035MB SFC HIGH BUILDS IN AND ALLOWS FOR
CLEARING AND STRONG RADIATIONAL COOLING. SOME RECORD LOWS ARE
POSSIBLE THURSDAY NIGHT...AND SHERIDAN MAY SEE A LOW TEMP NEAR 20
DEGREES...A REMARKABLE NUMBER FOR SEPTEMBER 12TH.
JKL
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
ONCE THE STORM SYSTEM EXITS THE AREA LATE THURSDAY...NORTHWESTERLY
FLOW WILL REMAIN OVER THE AREA INTO THE WEEKEND. LATEST MODEL RUNS
CONTINUE TO TREND DRIER WITH THE FORECAST FOR THE WEEKEND AS
CLIPPER TYPE DISTURBANCES IN THE NORTHWEST STAY MAINLY NORTH OF
THE AREA. THIS LEAVES A DRIER DOWNSLOPE REGIME IN PLACE FOR
SOUTHERN MONTANA. TEMPERATURES WILL REMAIN BELOW AVERAGE THROUGH
THE WEEKEND. BY EARLY NEXT WEEK FLOW ALOFT TURNS WESTERLY ALLOWING
STRONGER DOWNSLOPE WARMING AND DRYING...WITH TEMPERATURES
RESPONDING INTO THE 70S AND MAYBE EVEN LOWER 80S BY NEXT
WEDNESDAY. WILL KEEP AN EYE ON CLIPPER SYSTEM PROGRESSION FOR ANY
SIGNS OF A SOUTHWARD SHIFT THAT COULD BRING A PERIOD OF SHOWERS
TO THE AREA THIS WEEKEND...BUT OVERALL LOOKS LIKE A VERY PLEASANT
WEEKEND AHEAD AT THIS TIME. CHAMBERS
&&
.AVIATION...
IFR OR LOWER CONDITIONS WILL BE WIDESPREAD THIS MORNING...WITH
OCCASIONAL MVFR CONDITIONS WHERE SHOWER ACTIVITY DISTURBS THE NEAR
SURFACE STRATUS AND FOG. WARMING MID DAY SHOULD ALLOW CEILINGS AND
VISIBILITY TO IMPROVE A BIT WITH MVFR CONDITIONS PREVAILING DURING
THE AFTERNOON...THOUGH POCKETS OF IFR WILL PERSIST. IFR OR LOWER
CONDITIONS WILL QUICKLY RE-DEVELOP EARLY THIS EVENING AS
PRECIPITATION INCREASES WITH ARRIVAL OF MAIN STORM SYSTEM.
MOUNTAIN TOPS WILL SEE PERIODIC CLEARING ESPECIALLY THIS AFTERNOON
BUT PASSES WILL BE OBSCURED TODAY. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 045 032/044 029/060 038/061 042/065 045/072 048/077
7/R 98/O 10/U 01/U 11/U 10/U 11/U
LVM 047 030/044 024/060 032/062 034/069 040/074 044/081
6/R 97/O 10/U 01/U 11/U 10/U 01/U
HDN 047 034/046 028/061 037/064 041/068 044/073 046/077
7/R 98/O 20/U 01/U 11/U 11/U 11/U
MLS 047 034/049 031/061 038/063 041/066 044/070 047/077
8/R 64/O 20/U 01/U 11/U 11/U 01/U
4BQ 047 033/045 028/058 037/063 040/065 044/071 047/076
8/R 78/O 21/U 01/U 11/U 10/U 11/U
BHK 046 033/047 029/055 035/064 038/065 041/070 044/074
6/R 44/O 21/U 01/U 11/U 11/U 01/U
SHR 049 032/040 022/057 032/063 036/067 041/073 044/079
6/R ++/O 31/U 01/U 11/U 11/U 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO
NOON MDT THURSDAY FOR ZONES 28-41-63.
WINTER STORM WARNING IN EFFECT FROM 6 PM THIS EVENING TO 3 PM
MDT THURSDAY FOR ZONES 56-66-67.
WINTER STORM WARNING IN EFFECT FROM NOON TODAY TO 3 PM MDT
THURSDAY FOR ZONE 68.
WY...WINTER STORM WATCH IN EFFECT FROM THIS EVENING THROUGH
THURSDAY MORNING FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
659 AM EDT WED SEP 10 2014
.SYNOPSIS...
WEAK LOW PRESSURE PASSING SE OF NEW ENGLAND MAY BRING A FEW
SHOWERS TO THE ISLANDS TODAY...OTHERWISE DRY WEATHER WILL PREVAIL.
A COLD FRONT WILL SWING ACROSS THE REGION LATE THURSDAY AND EARLY
FRIDAY...THEN STALL JUST OFFSHORE. A DISTURBANCE MOVING ALONG THIS
FRONT SATURDAY MAY COME CLOSE ENOUGH TO RESULT IN SHOWERS. HIGH
PRESSURE RETURNS WITH DRY AND COOLER WEATHER SUNDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
700 AM UPDATE...
OVERALL TREND IN THE FORECAST REMAINS ON TRACK. HAVE MADE MINOR
UPDATES TO ACCOUNT FOR CURRENT CONDITIONS. A FEW SPRINKLES MAY
REACH ACK THIS MORNING. OTHERWISE EAST/NORTHEAST FLOW HAS ALLOWED
FOR LOW STRATUS AND PATCHY FOG...ESP ALONG THE NORTH SHORE WHERE
WIND SPEEDS ARE LESS. ANTICIPATE BOTH CLOUDS AND FOG TO LIFT
DURING THE MORNING HOURS.
PREVIOUS DISCUSSION....
MAIN BATCH OF SHOWERS REMAINS SE OF NANTUCKET AND EXPECT MOST OF
IT TO REMAIN OFFSHORE TODAY. MODELS SEEM TO BE STRUGGLING WITH HOW
CLOSE THESE SHOWERS GET TO SE NEW ENGLAND...BUT HRRR LOOKS
REASONABLE IN GRAZING NANTUCKET THROUGH MID MORNING. DRY AIR AT
MID LEVELS PER 00Z CHATHAM SOUNDING WILL PREVENT MUCH OF THIS FROM
REACHING GROUND...IN FACT WE MAY JUST END UP WITH FEW SPRINKLES ON
ISLANDS AND OUTER CAPE.
LOW CLOUDS AND PATCHY FOG WILL PREVAIL ELSEWHERE THROUGH DAYBREAK
DUE TO LIGHT ONSHORE FLOW...BUT WILL BREAK AFTER SUNRISE AND GIVE
WAY TO PARTLY TO MOSTLY SUNNY SKIES.
CONTINUED ONSHORE FLOW WILL KEEP HIGHS NEAR AVERAGE FOR MOST
PART...MAINLY IN 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
EXPECT A RETURN OF LOW CLOUDS/FOG TONIGHT WHICH SHOULD BE MORE
WIDESPREAD AS LOWER LEVELS MOISTEN WITH E/SE FLOW. MAY SEE AREAS
OF DENSE FOG ALONG IMMEDIATE COAST. OTHERWISE SURFACE RIDGE KEEPS
US DRY ASIDE FROM SPOTTY DRIZZLE.
COLD FRONT APPROACHES NEW ENGLAND THU BUT SHOULD REMAIN TO OUR W.
FLOW TURNS MORE S/SW IN ADVANCE OF FRONT WHICH WILL HELP SCOUR OUT
LOW CLOUDS/FOG IN THE MORNING...EXCEPT AROUND S COAST...CAPE COD
AND ISLANDS WHERE IT MAY PERSIST INTO AFTERNOON.
INSTABILITY LOOKS MARGINAL AND MID LEVEL LAPSE RATES ARE WEAK...
BUT ENOUGH TO INCLUDE MENTION OF THUNDER AHEAD OF FRONT. BETTER
CHANCES ACROSS INTERIOR WHERE S FLOW OFF OCEAN IS LESS OF
STABILIZING FACTOR. MODELS CONTINUE TO SHOW PLENTY OF MOISTURE
AVAILABLE WITH PRECIPITABLE WATER VALUES NEAR 2 INCHES /+2 TO +3
STANDARD DEVIATION/...SO LOCALLY HEAVY RAINFALL CAN BE EXPECTED.
HIGHS SHOULD REACH 70S AND LOWER 80S...AND IT WILL FEEL MORE
SUMMERLIKE AS DEWPOINTS CLIMB WELL INTO 60S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS/ISOLATED T-STORMS THU PM INTO EARLY FRI
* SLIGHT CHANGE FOR SHOWERS SAT PM/SUN
* A TASTE OF AUTUMN TEMPERATURES NEXT WEEK
OVERVIEW...
LATEST MODEL AND ENSEMBLE GUIDANCE OVERALL SEEMS TO OFFER FAIRLY
REASONABLE LARGER SCALE PATTERN EVOLUTION CONTINUITY. AN AMPLIFYING
ERN PAC TROUGH AND WEST COAST RIDGE DRIFTING INTO WRN NOAM WILL
SUPPORT MEAN MID-UPPER LEVEL TROUGHING OVER THE ERN HALF OF NOAM.
THIS PATTERN...MORE TYPICAL OF THE COLD SEASON THAN LATE SUMMER OR
EARLY FALL...SHOULD YIELD BELOW TO MUCH BELOW NORMAL TEMPS OVER MOST
OF THE ERN 2/3 OF THE CONUS. HOWEVER...DETERMINISTIC MODEL RUNS
FEATURE TOO MUCH INCONSISTENCY.
SEVERAL RIPPLES WILL MOVE THROUGH THE FLOW THROUGH THE PERIOD WITH
THE FIRST ONE BRINGING A COLD FRONT ON THURSDAY NIGHT/FRI MORNING.
ANOTHER SHORTWAVE WILL PASS SAT/SAT NIGHT. THIS ONE CAUSES MORE
UNCERTAINTY AS THE GFS IS HAVING CONVECTIVE FEEDBACK AND IS CREATING
A 1-2 INCH BULLS-EYE OVER THE REGION...IN RETROSPECT THE EC IS
PRODUCING VERY LIGHT QPF. LASTLY ANOTHER WAVE WILL MOVE TROUGH THE
FLOW MONDAY NIGHT/TUESDAY.
OVERALL HAVE MODERATE CONFIDENCE IN THE FORECAST AS THERE IS TO MUCH
SPREAD BETWEEN THE DETERMINISTIC AND ENSEMBLE FORECASTS ESP IN
SPECIFIC DETAILS IN THE FORECAST.
DETAILS...
THURSDAY NIGHT INTO FRIDAY...
THE FOCUS IS ON A STRONG COLD FRONT THAT WILL PUSH ACROSS THE REGION
THURSDAY NIGHT INTO FRIDAY MORNING. BOTH DETERMINISTIC AND ENSEMBLES
KEEP THE INSTABILITY VALUES VERY LOW BUT BECAUSE OF THE STRENGTH OF
THIS FRONT HAVE KEPT ISO MENTIONING OF THUNDER FOR THURSDAY. TIMED
THE THUNDER POTENTIAL WITH THE BETTER K-VALUES AND LI. PRECIPITABLE
WATERS INCREASE CONSIDERABLY...CLOSE TO 2-3 INCHES...WITH A
STRENGTHENING SOUTHERLY FLOW. SOME OF THESE STORMS MAY PRODUCE HEAVY
RAIN...WITH AN ISOLD FLASH FLOOD THREAT PRIMARILY IN URBANIZED
AREAS. THEREFORE ALSO INCLUDED HEAVY RAIN WORDING FOR ANY
THUNDERSTORM POTENTIAL.
HIGH PRESSURE WILL QUICKLY SWING INTO THE AREA BY FRIDAY ALLOWING
FOR THE DAY TO DRY OUT AND TEMPS TO REACH NEAR NORMAL.
SATURDAY TO SATURDAY NIGHT...
HIGH PRESSURE WILL BEGIN TO LIFT NORTHWARD ALLOWING FOR EASTERLY FLOW
ON SATURDAY. BY THE LATE AFTERNOON/EVENING HOURS A COLD FRONT WILL
PASS THROUGH REGION BRINGING ANOTHER CHANCE OF THUNDERSTORMS. AS
MENTIONED BEFORE...THERE IS SIGNIFICANT DIFFERENCE BETWEEN THE
DETERMINISTIC GUIDANCE WITH THE GFS PRODUCING A 1-2 INCH BULLS-EYE.
WHILE THE EC IS DEVELOPING LIGHT QPF. APPEARS THE GFS IS RECEIVING
CONVECTIVE FEEDBACK BUT BECAUSE BOTH ARE TRENDING TO MOVE
PRECIP...HAVE INCREASED THE POTENTIAL TO CHANCE POP.
SUNDAY INTO NEXT WEEKEND...
A MODIFIED CANADIAN HIGH WILL THEN BUILD IN THROUGH EARLY NEXT WEEK
BEFORE ANOTHER FRONTAL SYSTEM POSSIBLY IMPACTS THE AREA AROUND
TUES OF NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE THROUGH THU.
AREAS OF MVFR/IFR CIGS/VSBYS THROUGH 12Z WITH BRIEF SHOWER/
SPRINKLE POSSIBLE NEAR NANTUCKET AND VINEYARD. CONDITIONS IMPROVE
TO VFR AFTER 12Z FROM W TO E BUT MVFR CIGS MAY LINGER INTO EARLY
AFTERNOON.
CIGS/VSBYS LOWER AGAIN TONIGHT DUE TO PERSISTENT ONSHORE FLOW...
THIS TIME TO IFR/LIFR ACROSS MUCH OF REGION. CONDITIONS SLOWLY
IMPROVE TO VFR AGAIN THU MORNING...LAST ACROSS CAPE COD AND
ISLANDS THU AFTERNOON...BUT SCATTERED SHOWERS/THUNDERSTORMS
POSSIBLE ACROSS INTERIOR AFTER 18Z. MAY REACH BOS/PVD BY 22Z.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS BUT LOWER CONFIDENCE ON
EXACT TIMING.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...A PERIOD OF MVFR/IFR CONDITIONS POSSIBLE EARLY FRIDAY IN
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS AS A COLD FRONT SWEEPS
THROUGH. OTHERWISE...VFR CONDITIONS EXPECTED FOR A GOOD PORTION
OF THIS PERIOD.
SATURDAY...LOW CONFIDENCE. MAINLY VFR. ONSHORE FLOW COULD ALSO
RESULT IN IFR STRATUS AND FOG ACROSS PORTIONS OF THE EAST
COAST...PARTICULARLY CAPE COD AND THE ISLANDS.
SUNDAY...MODERATE CONFIDENCE. MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH THU.
SCA REMAINS POSTED FOR OUTER WATERS MAINLY DUE TO 5-6 FT SEAS
TODAY THROUGH THU.
E/NE WINDS GRADUALLY SUBSIDE TODAY AS LOW PRESSURE PASSES WELL SE
OF NEW ENGLAND...THEN S/SW WINDS DEVELOP THU AS COLD FRONT
APPROACHES FROM GREAT LAKES. MAIN CONCERN IS PATCHY DENSE FOG
TONIGHT INTO THU...ESPECIALLY ON S COASTAL WATERS.
OUTLOOK...FRIDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
FRIDAY...MODERATE CONFIDENCE. A ROUND OF SCATTERED SHOWERS AND
PERHAPS ISOLATED THUNDERSTORMS ARE EXPECTED EARLY FRIDAY MORNING
AS A COLD FRONT PASSES THROUGH. WINDS WILL MAY REACH ABOVE 25 KT
BEHIND THIS FRONT ALLOWING FOR SEAS TO APPROACH 5 FT AT TIMES
ACROSS THE OUTER COASTAL WATERS. SMALL CRAFT ADVISORIES MAY BE
NEEDED.
SATURDAY...LOW CONFIDENCE. TIGHTENING PRESSURE GRADIENT AND
APPROACHING COLD FRONT WILL HELP KEEP SEAS AND WINDS UP ON
SATURDAY. SMALL CRAFT ADV MAY BE NEEDED.
SUNDAY...STRONG COLD FRONT WILL PASS OVER THE WATERS IN THE
MORNING. COLD AIR ALOFT WILL INCREASE SEAS AND WIND GUSTS ON
SUNDAY LEADING TO THE POTENTIAL OF A SMALL CRAFT ADV.
&&
.TIDES/COASTAL FLOODING...
LAST HIGH TIDE JUST BEFORE MIDNIGHT PRODUCED 0.2 FT SURGE ALONG E
MA COAST. SUBSEQUENT HIGH TIDES TODAY INTO THU ARE A BIT LOWER AND
SURGE WILL BE MINIMAL...THEREFORE NO IMPACT IS EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...DUNTEN/JWD
NEAR TERM...DUNTEN/JWD
SHORT TERM...JWD
LONG TERM...DUNTEN
AVIATION...DUNTEN/JWD
MARINE...DUNTEN/JWD
TIDES/COASTAL FLOODING...JWD
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
1005 AM EDT WED SEP 10 2014
.UPDATE...EARLY MORNING RADAR TRENDS SHOW THE CLUSTER OF SHOWERS
AND A FEW STORMS HAVE DECREASED IN COVERAGE AND INTENSITY OVER THE
SE GA COASTAL WATERS AND THE SE GA COASTAL COUNTIES. STILL A FEW
MODERATE SHOWERS NEAR THE BRUNSWICK AREA THAT ARE LIFTING SLOWLY
NWD. SATELLITE AND SFC DATA AND HRRR MODEL SHOW THE TAIL END OF A
FRONTAL BOUNDARY ACROSS THE WRN ATLC THAT EXTENDS WWD TO ABOUT THE
COASTAL SE GA AND TO PERHAPS AROUND WAYCROSS AND THEN DIFFUSE
THEREAFTER INLAND S GA. PATCHY TO AREA OF FOG HAVE DISSIPATED
AFTER SOME VSBY DROPPED TO 1/4 MILE BRIEFLY OVER PORTIONS OF SE GA.
FOR REST OF TODAY...A FEW TWEAKS TO THE FORECAST TO BUMP UP TEMPS
A BIT MORE AND ADJUST POPS. THERE MAY BE SOME ENHANCED PRECIP
POTENTIAL OVER THE NEXT FEW HOURS OVER EXTREME NE FL JUST S OF THE
WEAK FRONTAL BOUNDARY...BUT NO MORE THAN 40% CHANCE FOR NOW FOR
NASSAU AND DUVAL COUNTIES. JUST NOW SEEING A FEW SHOWERS POP UP
ABOUT 20-30 MILES E OF FERNANDINA BEACH. OTHERWISE...WITH MID
LEVEL HIGH PRES OFFSHORE THE E COAST SEA BREEZE WILL HAVE NO
PROBLEMS MOVING INLAND THIS AFTERNOON WITH BEST COVERAGE OF SEA
BREEZE-INFLUENCED SHOWERS AND A FEW STORMS OVER INLAND NE FL WHERE
30-40% SHOULD BE MORE THAN ADEQUATE TO COVER THE PRECIP POTENTIAL.
ONLY 20-30% ADVERTISED FOR SE GA ATTM REST OF TODAY. MODIFIED
MODEL SOUNDINGS PRODUCE SBCAPE OF ABOUT 2000-2500 J/KG WITH
POTENTIAL DOWNBURST GUST TO 35 KNOTS (40 MPH)...WHICH WILL BE
MOST LIKELY OVER INLAND NE FL AFTER 2 PM TODAY.
&&
.AVIATION...PREVAILING VFR WITH SCT-LCL BROKEN CUMULUS 2500-3500
FT AND MID LEVEL CLOUDINESS AT TIMES. A FEW SHOWERS POSSIBLE
VICINITY OF NE FL COASTAL TAFS AS DAYTIME HEATING COMMENCES. HAVE
VCTS FOR GNV LATER THIS AFTERNOON. NO TEMPO GROUPS NEEDED ATTM.
WEAK AND VARIABLE WINDS NEXT FEW HOURS THEN BECOME ELY TO SE THIS
AFTERNOON.
&&
.MARINE...LIGHT WINDS WILL BECOMING SE TO E AROUND 10 KT AND SEAS
OF 2-3 FT.
RIP CURRENTS: LOW RISK OF RIP CURRENTS TODAY AND THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 90 71 93 73 / 20 20 20 10
SSI 85 76 86 75 / 30 10 10 10
JAX 88 74 90 73 / 30 10 20 10
SGJ 86 75 87 74 / 20 10 20 10
GNV 90 72 90 71 / 30 30 40 20
OCF 90 73 90 72 / 30 30 30 30
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
SHASHY/GUILLET
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
814 AM EDT WED SEP 10 2014
.SYNOPSIS...
A PRESSURE RIDGE EXTENDING THROUGH THE FORECAST AREA TODAY WILL BE
OFF THE COAST THURSDAY. A COLD FRONT WILL MOVE INTO THE FORECAST
AREA FRIDAY AND STALL.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE PRESSURE RIDGE EXTENDING INTO THE FORECAST AREA WILL SHIFT OFF
THE COAST THIS AFTERNOON AND TONIGHT. THERE WILL BE WEAK
CONVERGENCE ASSOCIATED WITH THE REMNANTS OF THE FRONT. THERE WERE A
FEW SHOWERS JUST SOUTH OF THE FORECAST AREA EARLY THIS MORNING.
SOME OF THE HIGH-RESOLUTION MODELS DISPLAY ISOLATED SHOWERS IN
MAINLY THE SOUTH PART OF THE FORECAST AREA THIS AFTERNOON AND
TONIGHT. HOWEVER...THE 08Z HRRR MAINTAINED DRY CONDITIONS
THROUGH TODAY. UPPER-RIDGING OVER THE AREA SHOULD HELP KEEP
MOISTURE SHALLOW WITH MID-LEVEL CAPPING. WE KEPT POPS LESS THAN 20
PERCENT. NOCTURNAL COOLING WITH SUFFICIENT LOW-LEVEL MOISTURE AND
DRY AIR ALOFT SHOULD HELP SUPPORT AREAS OF FOG LATE TONIGHT. THE
TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
HIGH PRESSURE WILL PUSH INTO THE ATLANTIC BASIN THURSDAY AS THE
NEXT COLD FRONT TRACKS TOWARD THE AREA. THE COLD FRONT WILL
CROSS THE OHIO AND TN VALLEYS THURSDAY THEN MOVE INTO THE UPSTATE
THURSDAY NIGHT. THIS WILL PRODUCE INCREASING CLOUDS AND WITH
SOUTHERLY WINDS PUSHING MOISTURE BACK INTO THE AREA. PWAT VALUES
WILL INCREASE...WITH VALUES BETWEEN 1.5 AND 2.00 INCHES. ALTHOUGH
THE MODELS INDICATE A POTENTIAL FOR SHOWERS AND THUNDERSTORMS
THURSDAY AFTERNOON KEPT SLIGHT CHANCE POPS AS DRY AIR ALOFT WILL
REMAIN ALONG WITH A MID-LEVEL CAP. POPS WILL INCREASE SLOWLY
THURSDAY NIGHT AS THE FRONT MOVES CLOSER TO THE FORECAST AREA WITH
THE BEST CHANCE ACROSS THE NORTHWESTERN SECTION. TEMPERATURES THURSDAY
WILL BE IN THE LOWER 90S GIVEN SLIGHT WARM ADVECTION AHEAD OF THE
COLD FRONT. SHOULD SEE OVERNIGHT LOWS IN THE LOWER 70S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
MODELS CONTINUE IN GOOD AGREEMENT THROUGH THE LONG TERM. THE COLD
FRONT WILL SLOW AS IT MOVES IN THE FORECAST AREA FRIDAY AND STALL
ACROSS THE AREA FRIDAY NIGHT THROUGH TUESDAY. WITH HIGH PRESSURE
BUILDING INTO THE SOUTHERN GREAT LAKES REGION SATURDAY COOLER AND
DRIER AIR WILL BEGIN MOVING SOUTHWARD THROUGH THE EASTERN US AND
BEGIN FILTERING INTO THE FORECAST AREA LATE IN THE WEEKEND. WITH
THE FRONT ACROSS THE REGION CHANCES OF SHOWERS AND THUNDERSTORMS
WILL CONTINUE WITH THE HIGHEST POPS CURRENTLY EXPECTED FRIDAY
THROUGH SATURDAY...WITH SOME UNCERTAINTY IN POPS FOR MONDAY AND
TUESDAY. TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR NORMAL
THROUGH FRIDAY NIGHT WITH BELOW NORMAL READINGS EXPECTED FOR
SATURDAY AND BELOW NORMAL FOR SUNDAY THROUGH TUESDAY.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE EVENING WITH GENERALLY HIGH
PRESSURE RIDGING INTO THE AREA. WEAK CONVERGENCE AND MOISTURE ASSOCIATED
WITH THE REMNANTS OF A FRONT COULD POSSIBLY HELP SUPPORT SHOWERS THIS
AFTERNOON AND TONIGHT BUT THE CHANCE IS VERY LOW BECAUSE OF UPPER-
LEVEL RIDGING WITH SHALLOW MOISTURE AND MID-LEVEL CAPPING.
NOCTURNAL COOLING WITH SUFFICIENT LOW-LEVEL MOISTURE AND DRY AIR
ALOFT SHOULD HELP SUPPORT AREAS OF FOG LATE TONIGHT AND EARLY
THURSDAY MORNING.
.EXTENDED AVIATION OUTLOOK...A FRONTAL SYSTEM WILL MOVE INTO THE
AREA THURSDAY NIGHT AND FRIDAY. THE FRONT WILL THEN STALL. WIDESPREAD
MVFR OR IFR CONDITIONS WILL LIKELY BE ASSOCIATED WITH THIS FEATURE
THURSDAY NIGHT THROUGH SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1150 AM EDT WED SEP 10 2014
.UPDATE...
ISSUED AT 1149 AM EDT WED SEP 10 2014
GENERALLY MINOR TWEAKS TO THE GOING FORECAST...LARGELY WITH PINNING
DOWN THE LOCATIONS OF THE HEAVIEST PRECIPITATION AND THEN WINDS FOR
THIS AFTERNOON AND TONIGHT BEHIND THE LOW.
AS FOR THE RAIN...ESSENTIALLY SEEING TWO AREAS OF
PRECIPITATION...ONE OVER THE EAST ALIGNED WITH THE BROAD 850-500MB
WARM AIR ADVECTION LIFTING TO THE NORTHEAST AHEAD OF THE LOW
CENTERED OVER SOUTH CENTRAL WISCONSIN. EXPECT THAT AREA TO CONTINUE
PUSHING TO THE NORTHEAST THROUGH THE DAY AND LARGELY DEPARTING BY
LATE AFTERNOON. THE SECOND AREA IS FARTHEST TO THE WEST AND TIED TO
THE 850-700MB FGEN AREA TO THE NORTHWEST OF THE MID LEVEL LOW.
OBSERVER REPORTS INDICATE THIS AREA OF RAIN PRODUCING AROUND
0.5-0.75IN EVERY THREE HOURS AND THAT MATCHES DUAL POL INSTANTANEOUS
PRECIP RATES. ALTHOUGH THIS AREA HAS BEEN PIVOTING AND SLOW TO MOVE
THIS MORNING...IT IS EXPECTED TO SHIFT MORE TO THE EAST-NORTHEAST
THIS AFTERNOON AS THE LOW QUICKLY MOVES NORTHEAST THROUGH NORTHERN
LAKE MICHIGAN. STILL HAVE THE FLOOD WATCH IN PLACE AND THAT SEEMS
REASONABLE OVER THE WEST (WITH THE ADDED PRECIP FROM OVERNIGHT
PUSHING TOTALS OVER 2 INCHES IN SOME LOCATIONS). FROM
MARQUETTE/DICKINSON COUNTY EAST...THINK THE POTENTIAL FOR FLOODING
IS PRETTY LIMITED BUT WILL LEAVE WATCH IN PLACE AT THIS TIME.
FINALLY FOR WINDS...MAIN ADJUSTMENTS WERE FOR AREAS OVER THE EAST
AND NEAR LAKE MICHIGAN. EXPECT THE COMBINATION OF STRONG COLD AIR
ADVECTION BEHIND THE LOW AND QUICK PRESSURE RISE TO LEAD TO GALES
AND HAVE ISSUED A GALE WARNING FOR OUR LAKE MICHIGAN ZONES. DO HAVE
A LITTLE CONCERN THAT GUSTS WILL BE NEAR 40-45MPH BRIEFLY LATE THIS
AFTERNOON INTO THE EVENING NEAR THE LAKE SUPERIOR SHORELINE AND
POTENTIALLY AT TIMES ELSEWHERE INLAND. THE OTHER AREA WAS OVER THE
KEWEENAW PENINSULA...ALTHOUGH THE FORECAST WAS IN DECENT
SHAPE...LATEST OBS AT KP59 INDICATE WINDS GUSTING TO NEAR WIND
ADVISORY CRITERIA. WITH THE CENTRAL LAKE SUPERIOR BUOY GUSTING
ABOVE 40KTS AND OTHER SITES NEAR WIND ADVISORY CRITERIA...WILL
ISSUE A WIND ADVISORY FOR KEWEENAW AND NORTHERN HOUGHTON COUNTIES
THROUGH THE EVENING HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EDT WED SEP 10 2014
LIGHT TO AT TIME HEAVY RAIN CONTINUES TO FALL OVER THE W THIRD OF
UPPER MI THIS MORNING...ASSOCIATED WITH THE SFC TROUGH THAT PUSHED
OVERHEAD EARLY THIS MORNING THE 500MB SHORTWAVE CROSSING WI...AND
THE DEEPENING SFC LOW RIDING UP ALONG THE TROUGH NEARING FROM IA.
THE LATEST SATELLITE AND RUC ANALYSIS SHOWS THIS INITIAL N SWATH OF
MOISTURE EJECTING NE ACROSS THE CWA...WITH THE EFFECTS OF THE SW TO
NE 100KT 250MB JET NEARING FROM THE PLAINS. THE SECONDARY AREA OF
CLOUDS WILL BE IMPACTING THE E HALF OF THE CWA LATER THIS MORNING
AND INTO THE AFTERNOON HOURS. EXACT RAINFALL TOTALS REMAIN TRICKY AS
THERE ARE 2 AREAS OF THOUGHT. THE LATEST 06Z NAM PAINTS AN
ADDITIONAL 1-2IN OVER CENTRAL AND E UPPER MI LATE THIS MORNING
THROUGH EARLY THIS AFTERNOON. HOWEVER...THE 00Z GFS IS PUSHING MUCH
OF THE MOISTURE JUST TO OUR E. HAVE GONE WITH A MIDDLE OF THE ROAD
SOLUTION FOR THE MOMENT...KNOWING THAT CONVECTION TO THE SOUTH COULD
STILL HURT THE INFLOW OF MOISTURE UP OUR WAY. STILL...ADDITIONAL
SHOWERS CROSSING THE CWA THIS AFTERNOON WITH BE FACED WITH STIFF N
ONSHORE FLOW...RESULTING IN A SLOWER N PROGRESSION AND OVERALL
UPSLOPE ENHANCEMENT. SEE THE HYDROLOGY SECTION FOR MORE DETAILS
ABOUT PRECIPITATION FOR THE REST OF TODAY. RAIN/RAIN SHOWERS WILL
CONTINUE THROUGH TONIGHT...MAINLY ACROSS THOSE UPSLOPE AREAS OF
CENTRAL UPPER MI. ADDITIONAL RAINFALL MAY ADD UP TO 0.25IN OR MORE
ACROSS THE HURON MOUNTAINS. FCST MODELS ARE CONTINUING TO GO WITH
THE SFC LOW TRACKING ACROSS N LOWER MI LATE THIS AFTERNOON...BEFORE
EXITING INTO S ONTARIO AND W QUEBEC LATE THIS EVENING.
TEMPERATURES WILL REMAIN TRICKY...AS THEY FALL W AND STILL RISE A
COUPLE OF DEGREES AFTER SUNRISE E. KEPT THE WIND FCST VERY SIMILAR
TO THE LAST COUPLE OF DAYS...WITH N-NNW GUSTS NEARING 35KTS FROM
AROUND 18Z TODAY TO 08Z TONIGHT. AN SPS MAY BE NEEDED FOR THE W HALF
AND HIGHER TERRAIN OF THE KEWEENAW PENINSULA...OR LOW END WIND
ADVISORY TO HIGHLIGHT THE STRONG WINDS ON TOP OF SATURATED SOILS
THAT MAY MORE EASILY UPROOT TREES THANKS TO THE ABUNDANT LEAVES. AS
FOR THE OVERNIGHT HOURS...EXPECT SLOWLY DIMINISHING WINDS LATE AND
COLD AIR TO FILTER IN WITH 850MB TEMPS OF -2 TO +4C BY DAYBREAK
THURSDAY. DEPENDING ON HOW FAST RAIN CAN GET OUT OF THE INTERIOR
AREAS ALONG THE WI BORDER...MID 30S LOWS WILL NOT BE OUT OF THE
QUESTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 603 AM EDT WED SEP 10 2014
OFF AND ON RAIN AND BR/FG HAVE BEEN THE TREND OVERNIGHT. ONCE THE
RAIN HAS ENDED IFR TO VLIFR CEILINGS HAVE DEVELOPED. INCREASING
WINDS THIS MORNING SHOULD HELP LIMITED THE BR. HOWEVER...LOW
CEILINGS WILL STILL BE POSSIBLE WITH ANY MODERATE RAIN THAT DEVELOPS.
LOOKING AT UPSTREAM CONDITIONS...LIFR CEILINGS WILL LIKELY DOMINATE
THE DAY AT IWD AND CMX. STEADIER RAIN WILL MOVE INTO SAW OVER THE
NEXT FEW HOURS. LOOK FOR STRONG WINDS DEVELOPING W TO E THIS
MORNING...WITH GUSTS OVER 30KTS POSSIBLE AT CMX FROM 19Z THIS
AFTERNOON TO 04Z THURSDAY. IWD MAY BE LIMITED TO GUSTS AROUND
20KTS...WHILE THE N WINDS GUST BETWEEN 25 AND 30KTS FROM 21Z TO 09Z
THURSDAY AT SAW AND KEEP LAKE EFFECT/ENHANCED RAIN SHOWERS GOING
THROUGH 12Z THURSDAY. DRIER AIR WILL SLOWLY WORK IN FROM THE
W...WITH ONLY A CHANCE OF SHOWERS AT CMX AND IWD BY DAYBREAK
THURSDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
MIZ001>006-009>013-084.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING UNTIL 5 AM EDT THURSDAY FOR LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THURSDAY FOR LMZ221-248-250.
&&
$$
UPDATE...SRF
SHORT TERM...KF
LONG TERM...KC
AVIATION...KF
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
543 AM CDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT WED SEP 10 2014
MODERATE TO HEAVY RAIN CONTINUES OVER MUCH OF EAST CENTRAL MN AND
WEST CENTRAL WISCONSIN. ALTHOUGH THE GREATER MOISTURE TRANSPORT HAS
EXITED TO THE SOUTHEAST OF THE AREA...FAIRLY STRONG MID LEVEL
FRONTOGENESIS REMAINS OVER TWO SPECIFIC AREAS OF THE CWA. ONE OVER
EAST CENTRAL MN AND NORTHWEST WISCONSIN AND THE OTHER DEVELOPING TO
THE SOUTHEAST...MOVING NOW INTO WEST CENTRAL WISCONSIN. THE RUC AND
NAM SHOW THIS GRADUALLY WEAKENING AND LIFTING OFF TO THE EAST
DURING THE MORNING. THIS SHOULD TAKE THE RAIN WITH IT. THE THREAT
OF PONDING WATER REMAINS MAINLY ACROSS WEST CENTRAL WISCONSIN INTO
THE MORNING. COLLABORATION WITH SURROUNDING OFFICES DID YIELD THE
CONTINUATION OF THE FLOOD WATCH INTO WEST CENTRAL WISCONSIN.
TODAYS HIGH TEMPERATURES WILL LIKELY OCCUR THIS MORNING AS WELL.
THEY MAY CONTINUE TO DROP OFF THROUGH MID MORNING OR SO BEFORE
LEVELING OFF INTO THE AFTERNOON. STRONG NORTH WINDS RE EXPECTED TO
DEVELOP EAST AS LOW LEVEL CAA SPREADS OVER THE REGION.
CLOUDS ARE EXPECTED TO HANG TOUGH OVER MUCH OF THE AREA INTO THE
NIGHT. THERE IS SOME INDICATION THAT IN THE WAKE OF THE
TROUGH...SUBSIDENCE COULD BE STRONG ENOUGH TO ERODE THE LOWER CLOUD
COVER. WINDS WILL SLOWLY DIMINISH AS THE LOW CONTINUE TO LIFT
EAST/NORTHEAST INTO THE NIGHT. IT SHOULD COOL RAPIDLY IF BREAKS DO
DEVELOP INTO THE NORTH CENTRAL CWA DURING THE NIGHT. SOME UPPER 30S
POSSIBLE WHERE THIS OCCURS. READINGS IN THE LOWER 40S SHOULD REMAIN
ELSEWHERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 327 AM CDT WED SEP 10 2014
THE LONG TERM FORECAST WILL FEATURE THE PASSAGE OF A SHORTWAVE
TROUGH AT THE BEGINNING OF THE PERIOD...FOLLOWED BY BRIEF SEMI-
ZONAL FLOW OVER THE WEEKEND...AND THEN A PATTERN TRANSITION TO
WESTERN RIDGING AND EASTERN TROUGHING THROUGH THE FIRST HALF OF
NEXT WEEK.
ON THURSDAY...A BROAD SURFACE HIGH BECOMES ESTABLISHED ACROSS THE
NATION/S MIDSECTION...WHILE A WEAK SHORTWAVE SLIDES EAST/SOUTHEAST
ACROSS THE AREA FROM THE NORTHERN/CANADIAN ROCKIES. WHILE THE
BETTER FORCING AND MORE PLENTIFUL MOISTURE WILL LIE SOUTH OF THE
FORECAST AREA...COULD SEE A FEW SHOWERS SNEAK INTO SOUTHERN MN AND
WEST CENTRAL WI LATE THURSDAY NIGHT AND FRIDAY. TEMPERATURES WILL
BE COOL...WITH HIGHS IN THE 50S ON THURSDAY AND FRIDAY...AND LOWS
DIPPING INTO THE MID TO UPPER 30S. DEPENDING ON HOW THE CLEARING
GOES AND WINDS...COULD POSSIBLY SEE SOME FROST ON SATURDAY
MORNING.
SATURDAY LOOKS TO HAVE THE HIGHEST POTENTIAL TO BE AN ENTIRELY DRY
DAY...AS SURFACE HIGH PRESSURE PREVAILS AND IN THE ABSENCE OF ANY
MID/UPPER DISTURBANCES.
SUNDAY BRINGS THE ARRIVAL OF WEAK SHORTWAVE ENERGY IN THE BASE OF
THE MANITOBA/ONTARIO TROUGH. MOISTURE AND FORCING ARE THE MOST
ROBUST NORTH AND EAST OF THE FORECAST AREA...BUT SUFFICIENT TO
WARRANT 20 POPS LOCALLY.
ON MONDAY...THINGS START TO DRY OUT WITH THE PATTERN EVOLUTION TO
WESTERN RIDGING. OVERALL...SHOULD BE DRY WITH SLIGHTLY BELOW
NORMAL TEMPERATURES THROUGH MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 534 AM CDT WED SEP 10 2014
IFR/LIFR CONDITIONS ACROSS MOST TAF SITES THIS MORNING GRADUALLY
IMPROVING TO MVFR CIGS BY LATE AFTERNOON/EVENING. INTENSITY OF
RAIN SHIELD DIMINISHING AS SURFACE LOW/FORCING MOVES EAST. WILL
END RAIN FROM WEST TO EAST DURING THE MORNING IN MN AND LATEST IN
WESTERN WI SITES. NORTH WINDS TO REMAIN STRONG MOST AREAS DURING
THE DAY...DIMINISHING THIS EVENING. WILL TREND TO VFR INTO THE
EVENING WITH THE EXCEPTION OF THE WISCONSIN SITES.
KMSP...IFR IMPROVING TO MVFR THIS AFTERNOON/22Z. WILL KEEP CIGS BELOW
1700 FT FOR NOW. LIGHT RAIN TO END BY LATE MORNING. WILL TREND
CIGS TO VFR THIS EVENING WITH DIMINISHING WINDS.
/OUTLOOK FOR KMSP/
WED NITE...MVFR EARLY THEN VFR. WINDS N AT 5 TO 10KTS.
THU...VFR. WINDS NW AT 10G15KTS.
FRI...VFR. WINDS NW AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...FLASH FLOOD WATCH UNTIL 10 AM CDT THIS MORNING FOR WIZ015-016-
023>028.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
930 AM MDT WED SEP 10 2014
.UPDATE...
OVERALL FORECAST IN GOOD SHAPE...BUT HAVE ADDED SOME DETAIL FOR
THE AFTERNOON. MESOSCALE MODELS IN GOOD AGREEMENT THAT WESTERN
AND CENTRAL ZONES WILL SEE A BREAK IN PRECIPITATION THIS AFTERNOON
BEFORE NEXT STRONG WAVE DROPS SOUTH INTO OUR REGION LATE TODAY AND
TONIGHT. BROKE UP AFTERNOON TO REFLECT THIS BY LOWERING POPS TO
JUST CHANCE VARIETY BEFORE TRENDING TO MUCH HIGHER POPS BY
EVENING. ALREADY SOME SNOW AT JUDITH GAP...SO ATMOSPHERE A LITTLE
AHEAD OF MODELS FOR SUPPORTING SNOW.
MAIN FORECAST ISSUES FOR THE AFTERNOON PACKAGE INVOLVE WHETHER TO
ADD HIGHLIGHTS FOR PARK COUNTY/PARADISE VALLEY...BIG HORN
COUNTY/SOUTHERN ROSEBUD...AND HOW TO HANDLE SHERIDAN COUNTY WHERE
CONCERN IS OVER HOW SOON/IF THEY CHANGE OVER TO SNOW RIGHT IN
SHERIDAN. BT
&&
.SHORT TERM...VALID FOR TDY AND THU...
MAIN FORECAST ISSUE REVOLVES AROUND POTENTIAL SNOW EVENT TONIGHT
INTO THURSDAY.
DYNAMIC UPPER LOW DROPPING ALONG THE SPINE OF THE CANADIAN
ROCKIES...WITH AN IMPRESSIVE 120KT H3 NWLY JET ANALYZED IN CENTRAL
BRITISH COLUMBIA. CLOUD TOPS IN STRONGLY DIFFLUENT REGION OF THIS
LOW HAVE BEEN COOLING RAPIDLY TONIGHT WITH TOPS TO -45C AT 08Z.
LATEST OBS TO OUR NORTH SHOW SNOW ALONG THE EASTERN SLOPES OF THE
CANADIAN ROCKIES FROM CALGARY TO EDSON. LATEST MODELS AND EVEN THE
07Z RAP SHOW THE JET NOSING TOWARD SOUTH CENTRAL MT BY THIS
EVENING...LEAVING US IN A FAVORABLE POSITION FOR UPPER DIVERGENCE.
ALL MODELS HAVE BEEN CONSISTENTLY SHOWING STRONG Q-VECTOR
CONVERGENCE OVER OUR CWA TONIGHT THRU MUCH OF THURSDAY. ASCENT
WILL NOT BE AN ISSUE WITH THIS SYSTEM...BUT AREA OF FRONTOGENESIS
AND UPSLOPE FLOW WILL DICTATE WHERE THE HEAVIEST PCPN WILL BE.
CONFIDENCE CONTINUES TO INCREASE FOR AN UPSLOPE EVENT
MATERIALIZING BY THIS EVENING AND LASTING THROUGH MUCH OF
THURSDAY. LATEST OBSERVATIONS TO OUR NORTH HELP TO GIVE CREDENCE
TO THIS SCENARIO. IT ALSO SHOULD BE NOTED THAT MID LEVEL LAPSE
RATES ON THE ORDER OF 6-7 C/KM OVER OUR WEST SUGGEST A CONVECTIVE
COMPONENT OF THE PCPN TONIGHT THROUGH THURSDAY.
PCPN CHANCES WILL BE INCREASING TODAY WITH ISENTROPIC ASCENT AND
DIFFLUENCE ALOFT AND LATEST REGIONAL RADAR SHOWS SHOWERS SPREADING
IN FROM THE NORTH. AREAS OF FOG/DRIZZLE ALSO EXIST PER THE LOW
LEVEL SATURATED LAYER WITH UPSLOPE WINDS. TEMPS ACROSS OUR CWA
WILL SUPPORT A CHILLY RAIN WITH THE EXCEPTION OF THE HIGH COUNTRY.
BY 00Z...SECONDARY PUSH OF COLD ADVECTION WILL KICK IN SO EXPECT
SNOW LEVELS TO FALL SIGNIFICANTLY BY THIS EVENING.
HAVE ISSUED A WINTER WX ADVISORY FOR OUR NW PARTS...SPECIFICALLY
FROM THE EAST SIDE OF THE CRAZY MTNS THROUGH JUDITH GAP...PER A
PERIOD OF DEEP EAST FLOW AS THE UPPER TROF MOVES IN AND AN
EXPECTED TRANSITION TO SNOW BY THIS EVENING. WOULD EXPECT THE
BEARTOOTH AND RED LODGE FOOTHILLS TO SEE UPSLOPE SNOWFALL
BEGINNING SOMETIME THIS EVENING ALSO. HAVE ISSUED A WINTER STORM
WARNING FOR THE FOOTHILLS AND ALSO THE NORTH/EAST SLOPES OF THE
BEARTOOTH...ABSAROKA AND CRAZY MTNS. FOR ALL OF THESE
HIGHLIGHTS THE SNOW AMTS WILL VARY PER ELEVATION BUT THE BIGGEST
IMPACT WILL BE THE POTENTIAL FOR DOWNED TREES AND POWER LINES.
ANYONE PLANNING TRIPS TO THE HIGH COUNTRY WILL ALSO BE IMPACTED
INCLUDING BEARTOOTH PASS. MODELS CONTINUE TO SUGGEST BETWEEN A
HALF INCH AND INCH OF PCPN DURING TIME OF PEAK ASCENT...SO SEVERAL
INCHES OF SNOWFALL COULD OCCUR IN THESE UPSLOPE AREAS. TURNING TO
THE BIG HORNS AND SHERIDAN COUNTY...THOUGH THE MTNS WILL SEE A
HEAVY SNOWFALL...TRANSITION TO SNOW WILL BE A BIT LATER FOR THE
CITY OF SHERIDAN...PERHAPS LATE EVENING OR INTO THE OVERNIGHT
HOURS. POTENTIAL STILL EXISTS FOR AN INCH OF WATER AND HEAVY
SNOWFALL ON THE EASTERN ASPECTS OF THE BIG HORNS. GIVEN SOME
UNCERTAINTY IN SFC TEMPS IN SHERIDAN WILL LET THE WATCH CONTINUE
AND HAVE THE DAY SHIFT MAKE THE FINAL CALL ON SPECIFIC
HIGHLIGHTS. OTHER LOCATIONS WHICH MAY BE IMPACTED INCLUDE THE
HIGHER HILLS ACROSS OUR SOUTHEAST FROM SOUTHERN BIG HORN TO POWDER
RIVER COUNTIES...SUCH PLACES AS THE WOLF MTNS AND LAME DEER
DIVIDE. WOULD EXPECT SOME SLUSHY ACCUMULATION IN THESE AREAS TOO
ESPECIALLY IF FRONTOGENESIS LINGERS A BIT NORTH OF THE FOOTHILLS
AS SOME MODELS SUGGEST. SYSTEM WILL WIND DOWN THURSDAY AFTERNOON
AND EVENING.
TEMPS TODAY AND THURSDAY WILL MAX OUT ONLY IN THE 40S...WITH SOME
RECORD COLD HIGH TEMPS BEING CHALLENGED. COLDEST NIGHT WILL BE
THURSDAY NIGHT AS 1035MB SFC HIGH BUILDS IN AND ALLOWS FOR
CLEARING AND STRONG RADIATIONAL COOLING. SOME RECORD LOWS ARE
POSSIBLE THURSDAY NIGHT...AND SHERIDAN MAY SEE A LOW TEMP NEAR 20
DEGREES...A REMARKABLE NUMBER FOR SEPTEMBER 12TH.
JKL
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
ONCE THE STORM SYSTEM EXITS THE AREA LATE THURSDAY...NORTHWESTERLY
FLOW WILL REMAIN OVER THE AREA INTO THE WEEKEND. LATEST MODEL RUNS
CONTINUE TO TREND DRIER WITH THE FORECAST FOR THE WEEKEND AS
CLIPPER TYPE DISTURBANCES IN THE NORTHWEST STAY MAINLY NORTH OF
THE AREA. THIS LEAVES A DRIER DOWNSLOPE REGIME IN PLACE FOR
SOUTHERN MONTANA. TEMPERATURES WILL REMAIN BELOW AVERAGE THROUGH
THE WEEKEND. BY EARLY NEXT WEEK FLOW ALOFT TURNS WESTERLY ALLOWING
STRONGER DOWNSLOPE WARMING AND DRYING...WITH TEMPERATURES
RESPONDING INTO THE 70S AND MAYBE EVEN LOWER 80S BY NEXT
WEDNESDAY. WILL KEEP AN EYE ON CLIPPER SYSTEM PROGRESSION FOR ANY
SIGNS OF A SOUTHWARD SHIFT THAT COULD BRING A PERIOD OF SHOWERS
TO THE AREA THIS WEEKEND...BUT OVERALL LOOKS LIKE A VERY PLEASANT
WEEKEND AHEAD AT THIS TIME. CHAMBERS
&&
.AVIATION...
IFR OR LOWER CONDITIONS WILL BE WIDESPREAD THIS MORNING...WITH
OCCASIONAL MVFR CONDITIONS WHERE SHOWER ACTIVITY DISTURBS THE NEAR
SURFACE STRATUS AND FOG. WARMING MID DAY SHOULD ALLOW CEILINGS AND
VISIBILITY TO IMPROVE A BIT WITH MVFR CONDITIONS PREVAILING DURING
THE AFTERNOON...THOUGH POCKETS OF IFR WILL PERSIST. IFR OR LOWER
CONDITIONS WILL QUICKLY RE-DEVELOP EARLY THIS EVENING AS
PRECIPITATION INCREASES WITH ARRIVAL OF MAIN STORM SYSTEM.
MOUNTAIN TOPS WILL SEE PERIODIC CLEARING ESPECIALLY THIS AFTERNOON
BUT PASSES WILL BE OBSCURED TODAY. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 045 032/044 029/060 038/061 042/065 045/072 048/077
9/R 98/O 10/U 01/U 11/U 10/U 11/U
LVM 047 030/044 024/060 032/062 034/069 040/074 044/081
6/R 97/O 10/U 01/U 11/U 10/U 01/U
HDN 047 034/046 028/061 037/064 041/068 044/073 046/077
9/R 98/O 20/U 01/U 11/U 11/U 11/U
MLS 047 034/049 031/061 038/063 041/066 044/070 047/077
9/R 64/O 20/U 01/U 11/U 11/U 01/U
4BQ 047 033/045 028/058 037/063 040/065 044/071 047/076
8/R 78/O 21/U 01/U 11/U 10/U 11/U
BHK 046 033/047 029/055 035/064 038/065 041/070 044/074
7/R 44/O 21/U 01/U 11/U 11/U 01/U
SHR 049 032/040 022/057 032/063 036/067 041/073 044/079
6/R ++/O 31/U 01/U 11/U 11/U 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO
NOON MDT THURSDAY FOR ZONES 28-41-63.
WINTER STORM WARNING IN EFFECT FROM 6 PM THIS EVENING TO 3 PM
MDT THURSDAY FOR ZONES 56-66-67.
WINTER STORM WARNING IN EFFECT UNTIL 3 PM MDT THURSDAY FOR
ZONE 68.
WY...WINTER STORM WATCH IN EFFECT FROM 6 PM MDT THIS EVENING
THROUGH THURSDAY MORNING FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1137 AM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE OVER IOWA WILL MOVE ACROSS LAKE HURON PULLING A STRONG
COLD FRONT ACROSS THE AREA WEDNESDAY NIGHT. A WAVE OF LOW PRESSURE
WILL MOVE UP THE OHIO VALLEY FRIDAY NIGHT INTO SATURDAY THEN HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE EAST THROUGH THE REGION
SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...MADE MORE ADJUSTMENTS TO POPS AND WX BASED ON CURRENT
RADAR TRENDS AND HRRR PROGS.
ORIGINAL...THE QUESTION TODAY IS HOW FAR OUT
AHEAD OF THE APPROACHING COLD FRONT WILL THE TSRA OCCUR. THE
LATEST MODEL RUNS HAVE QPF RAPIDLY SPREADING ESE ACROSS THE CWA
BETWEEN 18Z AND 00Z. WILL INCREASE POPS MORE FOR TODAY. THE THREAT
FOR SEVERE STORMS STILL LOOKS GOOD BASED ON INSTABILITY AND FAIRLY
GOOD WIND SHEAR. PW`S RISE BACK TO AROUND 2 INCHES SO LOCALLY
HEAVY RAIN CAN BE EXPECTED.
PATCHY MORNING FOG IN THE SOUTH WILL DISSIPATE THROUGH 10 AM.
TODAY WILL BE THE LAST RELATIVELY WARM DAY FOR A WHILE...POSSIBLY
THE REST OF THE SEASON BASED ON UPPER TROUGHING THAT IS GOING TO SET
UP OVER THE LAKES FOR AT LEAST THE NEXT 10 DAYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A FINAL BAND OF TSRA WITH THE STRONG COLD FRONT SHOULD PROGRESS
ACROSS THE CWA BETWEEN 06Z AND 12Z SO AFTER 12Z THU ONLY THE SE HALF
OF THE CWA SHOULD STILL HAVE A THREAT FOR RAIN WITH THE STRONGER
CONVECTION THEN EXITING THE CWA.
DRIER AIR MOVES IN BEHIND THE FRONT ALONG WITH THE LEADING PART OF A
MUCH COOLER AIRMASS. MARGINAL LAKE EFFECT CONDITIONS START TO
DEVELOP BY THE END OF THU NIGHT SO A FEW SHRA COULD BREAK OUT OVER
THE SNOWBELT AND NEARBY AREAS.
A SHARP S/W IS PROGGED TO MOVE EAST ACROSS THE LAKES FRI NIGHT INTO
SAT AND INDUCE A SURFACE WAVE THAT MOVES UP THE OH VALLEY. MOISTURE
POOLS BACK OVER THE AREA WITH WIDESPREAD SHRA DEVELOPING FRI NIGHT
AND CONTINUING INTO SAT BEFORE SHIFTING INTO MAINLY THE EAST SAT
AFTERNOON.
HIGH PRESSURE IS SHOWN TO BE QUICKLY SPREADING OVER THE AREA BY SAT
NIGHT BUT LAKE EFFECT CONDITIONS ARE POSSIBLE BASED ON TEMP
DIFFERENCES. DUE TO WIND ISSUES AND SUBSIDENCE FROM THE HIGH WILL
KEEP ONLY A SLIGHT CHANCE GOING SAT NIGHT IN THE NE.
TEMPS WILL TREND COOLER FOR FRI AND SAT WITH HIGHS BOTH DAYS MOSTLY
60 TO 65 DEGREES. SOME SPOTS ON SAT MAY NOT EVEN GET TO 60 DEGREES
IN THE INLAND EAST IF CLOUD COVER AND SHRA PERSIST. THE INCREASING
CLOUDS FRI NIGHT SHOULD HOLD UP LOWS IN A 45 TO 50 RANGE BUT BY SAT
NIGHT THE DECREASED CLOUDS AND LIGHT WINDS WILL ALLOW FOR LOWS IN
THE LOW TO MID 40S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
COOL HIGH PRESSURE WILL BE IN CONTROL OF THE REGION ON SUNDAY BUT IT
WILL BE SHIFTING OFF TO THE EAST AS ANOTHER UPPER LEVEL TROUGH DIGS
INTO THE GREAT LAKES REGION. AS THIS TROUGH MOVES OVERHEAD IT WILL
BRING AN INCREASING CHANCE OF SHOWERS. THE BETTER CHANCES OF THE
SHOWERS WILL BE MONDAY NIGHT INTO TUESDAY. THE SHOWERS MAY LINGER
DOWNWIND OF LAKE ERIE INTO TUESDAY EVENING. THE NEXT AREA OF HIGH
PRESSURE WILL THEN DRY THINGS OUT TUESDAY NIGHT INTO WEDNESDAY.
IT WILL BE COOL THROUGH THE LONG TERM WITH TEMPERATURES BELOW
SEASONAL AVERAGES. HIGHS AT MOST LOCATIONS WILL REMAIN IN THE 60S.
HOWEVER BY TUESDAY AND WEDNESDAY THE WESTERN COUNTY WARNING AREA
WILL BE NEAR TO SLIGHTLY ABOVE 70.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SOME PATCHY MVFR FOG ACROSS THE EASTERN HALF OF THE REGION WILL
BURN OFF QUICKLY.
GUSTY SOUTHERLY WINDS WILL DEVELOP BY MID TO LATE MORNING AS A
COLD FRONT MOVES TOWARD THE REGION. WIND GUSTS MAY REACH 30 TO 35
KNOTS NEAR THE LAKESHORE FROM CLEVELAND AND POINTS WEST FOR THE
AFTERNOON AND EVENING.
THE MAIN CONCERN WILL BE THE STRENGTH OF THE THUNDERSTORMS THAT
DEVELOP THIS AFTERNOON/EVENING. HAVE MOVED UP THE TIMING OF
THUNDERSTORMS TODAY WITH CURRENT RADAR TRENDS ALREADY SHOWING
SHOWERS AND THUNDERSTORMS INTO CENTRAL INDIANA. THE FASTER TIMING
COULD END UP BEING A GOOD THING SINCE THICKER CLOUD COVER WILL
DECREASE THE INSTABILITY. THESE SHOWERS AND THUNDERSTORMS WILL
THEN SLOWLY TRACK ACROSS THE REGION THROUGH THE OVERNIGHT.
OUTLOOK...NON VFR POSSIBLE WEDNESDAY NIGHT INTO THURSDAY IN
SHOWERS AND THUNDERSTORMS. LOWER CEILINGS MAY LINGER OVER NE OHIO
AND NW PA INTO FRIDAY AND SATURDAY.
&&
.MARINE...
LOW PRESSURE WILL MOVE INTO THE CENTRAL GREAT LAKES TODAY WITH
INCREASING SOUTH TO SOUTHWEST WINDS EXPECTED INTO THIS EVENING.
WINDS WILL INCREASE THE EARLIEST ACROSS THE WESTERN BASIN WITH
SOUTHERLY WINDS IN THE 15 TO 25 KNOT RANGE. WINDS WILL BE OFFSHORE
SO WAVES SHOULD NOT BUILD ALL THAT MUCH. SINCE WINDS ARE EXPECTED TO
BE IN THE 15 TO 25 KNOT RANGE WE HOISTED THE SMALL CRAFT ADVISORY
FOR THIS AFTERNOON.
WINDS WILL EVENTUALLY SHIFT AROUND TO THE WEST AND NORTHWEST IN THE
WAKE OF THE COLD FRONT TONIGHT. THE FRONT SHOULD BE EAST OF THE LAKE
BY 12Z THURSDAY. THE REMAINDER OF THE LAKE WILL NEED TO HAVE A SMALL
CRAFT ADVISORY AT SOME POINT THIS EVENING INTO THE OVERNIGHT. LATER
SHIFTS WILL ISSUE IT WHEN IT IS NEEDED. THE COLD ADVECTION IN THE
WAKE OF THE FRONT WILL KEEP LARGER WAVES (4-6 FEET) GOING INTO AT
LEAST THURSDAY AFTERNOON/EVENING. AS HIGH PRESSURE RIDGES OVER THE
REGION WINDS WILL BECOME NORTHEAST BY FRIDAY MORNING. THIS WILL SET
UP A LONG FETCH INTO THE WESTERN HALF OF THE LAKE. IF THE PRESSURE
GRADIENT CAN REMAIN TIGHT ENOUGH WE MAY NEED SMALL CRAFT ADVISORIES
AGAIN FRIDAY INTO SATURDAY. MORE DETAILS TO COME ON THIS SCENARIO
THE NEXT COUPLE DAYS.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT
AND TRACK ACROSS MUCH OF THE LAKE. A FEW OF THESE THUNDERSTORMS WILL
BECOME STRONG ENOUGH TO WARRANT THE ISSUANCE OF SPECIAL MARINE
WARNINGS FOR THIS EVENING AND POSSIBLY INTO THE OVERNIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THURSDAY FOR LEZ142>145.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/TK
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
948 AM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE OVER IOWA WILL MOVE ACROSS LAKE HURON PULLING A STRONG
COLD FRONT ACROSS THE AREA WEDNESDAY NIGHT. A WAVE OF LOW PRESSURE
WILL MOVE UP THE OHIO VALLEY FRIDAY NIGHT INTO SATURDAY THEN HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE EAST THROUGH THE REGION
SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...MADE SOME ADJUSTMENTS TO POPS AND WX BASED ON CURRENT
RADAR TRENDS AND HRRR PROGS.
ORIGINAL...THE QUESTION TODAY IS HOW FAR OUT
AHEAD OF THE APPROACHING COLD FRONT WILL THE TSRA OCCUR. THE
LATEST MODEL RUNS HAVE QPF RAPIDLY SPREADING ESE ACROSS THE CWA
BETWEEN 18Z AND 00Z. WILL INCREASE POPS MORE FOR TODAY. THE THREAT
FOR SEVERE STORMS STILL LOOKS GOOD BASED ON INSTABILITY AND FAIRLY
GOOD WIND SHEAR. PW`S RISE BACK TO AROUND 2 INCHES SO LOCALLY
HEAVY RAIN CAN BE EXPECTED.
PATCHY MORNING FOG IN THE SOUTH WILL DISSIPATE THROUGH 10 AM.
TODAY WILL BE THE LAST RELATIVELY WARM DAY FOR A WHILE...POSSIBLY
THE REST OF THE SEASON BASED ON UPPER TROUGHING THAT IS GOING TO SET
UP OVER THE LAKES FOR AT LEAST THE NEXT 10 DAYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A FINAL BAND OF TSRA WITH THE STRONG COLD FRONT SHOULD PROGRESS
ACROSS THE CWA BETWEEN 06Z AND 12Z SO AFTER 12Z THU ONLY THE SE HALF
OF THE CWA SHOULD STILL HAVE A THREAT FOR RAIN WITH THE STRONGER
CONVECTION THEN EXITING THE CWA.
DRIER AIR MOVES IN BEHIND THE FRONT ALONG WITH THE LEADING PART OF A
MUCH COOLER AIRMASS. MARGINAL LAKE EFFECT CONDITIONS START TO
DEVELOP BY THE END OF THU NIGHT SO A FEW SHRA COULD BREAK OUT OVER
THE SNOWBELT AND NEARBY AREAS.
A SHARP S/W IS PROGGED TO MOVE EAST ACROSS THE LAKES FRI NIGHT INTO
SAT AND INDUCE A SURFACE WAVE THAT MOVES UP THE OH VALLEY. MOISTURE
POOLS BACK OVER THE AREA WITH WIDESPREAD SHRA DEVELOPING FRI NIGHT
AND CONTINUING INTO SAT BEFORE SHIFTING INTO MAINLY THE EAST SAT
AFTERNOON.
HIGH PRESSURE IS SHOWN TO BE QUICKLY SPREADING OVER THE AREA BY SAT
NIGHT BUT LAKE EFFECT CONDITIONS ARE POSSIBLE BASED ON TEMP
DIFFERENCES. DUE TO WIND ISSUES AND SUBSIDENCE FROM THE HIGH WILL
KEEP ONLY A SLIGHT CHANCE GOING SAT NIGHT IN THE NE.
TEMPS WILL TREND COOLER FOR FRI AND SAT WITH HIGHS BOTH DAYS MOSTLY
60 TO 65 DEGREES. SOME SPOTS ON SAT MAY NOT EVEN GET TO 60 DEGREES
IN THE INLAND EAST IF CLOUD COVER AND SHRA PERSIST. THE INCREASING
CLOUDS FRI NIGHT SHOULD HOLD UP LOWS IN A 45 TO 50 RANGE BUT BY SAT
NIGHT THE DECREASED CLOUDS AND LIGHT WINDS WILL ALLOW FOR LOWS IN
THE LOW TO MID 40S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
COOL HIGH PRESSURE WILL BE IN CONTROL OF THE REGION ON SUNDAY BUT IT
WILL BE SHIFTING OFF TO THE EAST AS ANOTHER UPPER LEVEL TROUGH DIGS
INTO THE GREAT LAKES REGION. AS THIS TROUGH MOVES OVERHEAD IT WILL
BRING AN INCREASING CHANCE OF SHOWERS. THE BETTER CHANCES OF THE
SHOWERS WILL BE MONDAY NIGHT INTO TUESDAY. THE SHOWERS MAY LINGER
DOWNWIND OF LAKE ERIE INTO TUESDAY EVENING. THE NEXT AREA OF HIGH
PRESSURE WILL THEN DRY THINGS OUT TUESDAY NIGHT INTO WEDNESDAY.
IT WILL BE COOL THROUGH THE LONG TERM WITH TEMPERATURES BELOW
SEASONAL AVERAGES. HIGHS AT MOST LOCATIONS WILL REMAIN IN THE 60S.
HOWEVER BY TUESDAY AND WEDNESDAY THE WESTERN COUNTY WARNING AREA
WILL BE NEAR TO SLIGHTLY ABOVE 70.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SOME PATCHY MVFR FOG ACROSS THE EASTERN HALF OF THE REGION WILL
BURN OFF QUICKLY.
GUSTY SOUTHERLY WINDS WILL DEVELOP BY MID TO LATE MORNING AS A
COLD FRONT MOVES TOWARD THE REGION. WIND GUSTS MAY REACH 30 TO 35
KNOTS NEAR THE LAKESHORE FROM CLEVELAND AND POINTS WEST FOR THE
AFTERNOON AND EVENING.
THE MAIN CONCERN WILL BE THE STRENGTH OF THE THUNDERSTORMS THAT
DEVELOP THIS AFTERNOON/EVENING. HAVE MOVED UP THE TIMING OF
THUNDERSTORMS TODAY WITH CURRENT RADAR TRENDS ALREADY SHOWING
SHOWERS AND THUNDERSTORMS INTO CENTRAL INDIANA. THE FASTER TIMING
COULD END UP BEING A GOOD THING SINCE THICKER CLOUD COVER WILL
DECREASE THE INSTABILITY. THESE SHOWERS AND THUNDERSTORMS WILL
THEN SLOWLY TRACK ACROSS THE REGION THROUGH THE OVERNIGHT.
OUTLOOK...NON VFR POSSIBLE WEDNESDAY NIGHT INTO THURSDAY IN
SHOWERS AND THUNDERSTORMS. LOWER CEILINGS MAY LINGER OVER NE OHIO
AND NW PA INTO FRIDAY AND SATURDAY.
&&
.MARINE...
LOW PRESSURE WILL MOVE INTO THE CENTRAL GREAT LAKES TODAY WITH
INCREASING SOUTH TO SOUTHWEST WINDS EXPECTED INTO THIS EVENING.
WINDS WILL INCREASE THE EARLIEST ACROSS THE WESTERN BASIN WITH
SOUTHERLY WINDS IN THE 15 TO 25 KNOT RANGE. WINDS WILL BE OFFSHORE
SO WAVES SHOULD NOT BUILD ALL THAT MUCH. SINCE WINDS ARE EXPECTED TO
BE IN THE 15 TO 25 KNOT RANGE WE HOISTED THE SMALL CRAFT ADVISORY
FOR THIS AFTERNOON.
WINDS WILL EVENTUALLY SHIFT AROUND TO THE WEST AND NORTHWEST IN THE
WAKE OF THE COLD FRONT TONIGHT. THE FRONT SHOULD BE EAST OF THE LAKE
BY 12Z THURSDAY. THE REMAINDER OF THE LAKE WILL NEED TO HAVE A SMALL
CRAFT ADVISORY AT SOME POINT THIS EVENING INTO THE OVERNIGHT. LATER
SHIFTS WILL ISSUE IT WHEN IT IS NEEDED. THE COLD ADVECTION IN THE
WAKE OF THE FRONT WILL KEEP LARGER WAVES (4-6 FEET) GOING INTO AT
LEAST THURSDAY AFTERNOON/EVENING. AS HIGH PRESSURE RIDGES OVER THE
REGION WINDS WILL BECOME NORTHEAST BY FRIDAY MORNING. THIS WILL SET
UP A LONG FETCH INTO THE WESTERN HALF OF THE LAKE. IF THE PRESSURE
GRADIENT CAN REMAIN TIGHT ENOUGH WE MAY NEED SMALL CRAFT ADVISORIES
AGAIN FRIDAY INTO SATURDAY. MORE DETAILS TO COME ON THIS SCENARIO
THE NEXT COUPLE DAYS.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT
AND TRACK ACROSS MUCH OF THE LAKE. A FEW OF THESE THUNDERSTORMS WILL
BECOME STRONG ENOUGH TO WARRANT THE ISSUANCE OF SPECIAL MARINE
WARNINGS FOR THIS EVENING AND POSSIBLY INTO THE OVERNIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THURSDAY FOR LEZ142>145.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/TK
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1122 AM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE OVER THE MIDDLE PART OF THE COUNTRY WILL STRENGTHEN
AS IT MOVES INTO THE GREAT LAKES TODAY. THE TRAILING COLD FRONT
WILL MOVE EAST INTO THE OHIO AND TENNESSEE VALLEYS TONIGHT AND
THURSDAY...THEN CROSS THE MOUNTAINS THURSDAY NIGHT. THE FRONT IS
EXPECTED TO STALL OVER THE CAROLINAS FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1113 AM EDT WEDNESDAY...
UPDATING TO LOWER TEMPS A BIT AND HOLD CLOUDS LONGER ESPCLY ALONG
THE BLUE RIDGE WHERE LOW CLOUDS REMAIN PERSISTENT WITH EVEN SOME
SPOTTY -RA MIXED IN GIVEN THE WEAK LOW LEVEL VEERING PROFILE OFF
MORNING RAOBS. ALSO WITH SO MUCH LINGERING MOISTURE STUCK BENEATH
MULTIPLE INVERSIONS ALOFT OFF 12Z SOUNDINGS APPEARS WILL BE TOUGH
TO GET A QUICK EROSION OF THE CANOPY WITHOUT IT FILLING BACK IN
ESPCLY EARLY ON. EXPECT ONCE THE FLOW TURNS MORE SOUTH/SW LATER ON
AND MIXING INCREASES WILL SEE SOME DRIER AIR ALOFT MIX DOWN BUT
MAY BE LATE BEFORE THE EASTERN SLOPES OF THE BLUE RIDGE SEE A LOT
OF SUN. TEMPS LIKELY TO JUMP WHERE DO GET SOME SUSTAINED BREAKS
BUT FOR NOW BASED ON LATEST TRENDS AND LAV MOS...THINK HIGHS MAY
REMAIN IN THE 70S EXCEPT FOR THE FAR EAST/SE AND WESTERN PERIMETER
COUNTIES. ISOLATED WESTERN POPS THIS AFTERNOON STILL APPEAR OK
WITH THE BRIEF SHOTGUN PATTERN SUGGESTED BY THE LATEST HRRR BUT
THIS BASED ON SOME INSTABILITY PER HEATING WHICH MAY ONLY OCCUR
ALONG THE I-77 CORRIDOR AT THIS POINT.
PREVIOUS UPDATE AS OF 925 AM EDT WEDNESDAY...
ADDED SLIGHT CHANCE POPS ALONG THE BLUE RIDGE UP TO ROANOKE AS
SURFACE OBS AND WEATHER SPOTTERS HAVE CONFIRMED SOME LIGHT DRIZZLE
THIS MORNING. TWEAKED THE SKY GRIDS OUT WEST WHERE THERE HAS BEEN
SOME CLEARING. ALSO ADJUSTED THE NEAR TERM TEMPS. ALL OTHER
FORECAST DETAILS FROM THE PREVIOUS DISCUSSION REMAIN ON TRACK.
PREVIOUS DISCUSSION AS OF 430 AM EDT WEDNESDAY...
STARTING OFF WITH LOTS OF CLOUD COVER THIS MORNING...COURTESY OF
LINGERING MOISTURE BANKED UP AGAINST THE EAST SIDE OF THE
MOUNTAINS. THE EASTERLY WIND WHICH HAS BEEN KEEPING THE CLOUDS
PINNED ACROSS THE AREA WILL WEAKEN TODAY AS FLOW BEGINS TO TREND
MORE SOUTHERLY PER APPROACH OF FRONTAL SYSTEM OVER THE MIDDLE PART
OF THE COUNTRY.
AS OF 4AM...CYCLOGENESIS WAS TAKING PLACE OVER THE MIDDLE PART OF
THE COUNTRY WITH LOW PRESSURE DEVELOPING NEAR TOPEKA KANSAS. THIS
AREA OF LOW PRESSURE IS FORECAST TO STRENGTHEN TODAY PER STRONG
DYNAMICS ALOFT ASSOCIATED WITH A SHORT WAVE TROUGH EXITING THE
ROCKIES. THE DEEPENING LOW...10 MB PRESSURE FALL OVER THE NXT 12
HOURS...IS PROGGED TO MOVE NORTHEAST INTO THE GREAT LAKES...THE
TRAILING COLD FRONT SLICING SOUTH THROUGH MISSOURI-TEXAS. AHEAD OF
THE FRONT...WINDS WILL BE SOUTHWESTERLY THROUGH THE TENNESSEE AND
OHIO VALLEYS...WARM AIR ADVECTION TAKING PLACE UPSTREAM OF OUR
FORECAST AREA...AND EVENTUALLY INCLUDING OUR FORECAST AREA LATER
TODAY AND TONIGHT.
AS WARM AIR ADVECTION INCREASES FROM THE SOUTHWEST LATER
TODAY...EXPECT CLOUD COVER CURRENTLY OVER OUR FORECAST AREA TO MIX
OUT WITH INCREASING AMOUNTS OF SUN. SUNNY BREAKS WILL LIKELY BEGIN
IN THE WESTERN PART OF THE CWA FIRST...THEN SPREAD EAST. MORE SUN
MEANS WARMER TEMPERATURES...MODEL MOS SUGGESTING WE TEST 80 TODAY
WITH A TEMPERATURE RANGE OF 76 TO 83. MILD TEMPERATURES ARE LIKELY
TONIGHT...SOUTHWEST WINDS CONTINUING TO PROMOTE WARM AIR
ADVECTION...LOWS IN THE 60S.
NOT MUCH THREAT FOR PRECIP TODAY OR TONIGHT. MODEL SOUNDINGS
INDICATE CAPE VALUES POTENTIALLY REACHING 500 J/KG IN THE
MOUNTAINS TODAY. THIS MAY SUPPORT AN ISOLATED SHOWER OR TWO...BUT
NOT MUCH MORE THAN THAT. BETTER CHANCE FOR PRECIP WILL COME WITH
THE FRONTAL PASSAGE LATER THURSDAY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
LOOK FOR THURSDAY TO BE THE WARMEST DAY OF THE WEEK AS DEEP
SOUTHWESTERLY FLOW BECOMES ESTABLISHED AHEAD OF A STRONG COLD FRONT
APPROACHING FROM THE GREAT LAKES REGION. THE SOUTHWESTERLY WINDS
WILL DRAW VERY WARM GULF MOISTURE NORTHWARD ALONG THE APPALACHIAN
CHAIN...WHICH WILL HELP AFTERNOON HIGHS CLIMB INTO THE UPPER 70S/LOW
80S ACROSS THE MOUNTAINS...WHILE THE PIEDMONT WILL REACH INTO THE
MID 80S TO AROUND 90 IN THE SOUTHSIDE. RAIN CHANCES WILL INCREASE
DRASTICALLY DURING THE AFTERNOON AS THE FRONT CROSSES THE OHIO
RIVER...WITH SHOWERS AND THUNDERSTORMS BECOMING WIDESPREAD ACROSS
MOST OF THE AREA BY SUNSET.
STORM PREDICTION CENTER HAS MUCH OF OUR FORECAST REGION UNDER A
SLIGHT CHANCE FOR SEVERE THUNDERSTORMS...SO WILL BE ON THE LOOKOUT
FOR A FEW STORMS PACKING GUSTY WINDS DURING THE EVENING...MAINLY
NORTH OF HIGHWAY 460...AS THE STRONGER DOWNDRAFTS TRY TO PULL THE
25KT-30KT 850MB WINDS DOWN TO THE SURFACE. BELIEVE THERE WILL ALSO
BE A CHANCE FOR LOCALLY HEAVY RAIN ACROSS THE MOUNTAINS AS GULF
MOISTURE POOLING AHEAD OF THE FRONT PUSHES PRECIPITABLE WATER IN THE
BALLPARK OF 2 INCHES.
THE COLD FRONT WILL CONTINUE ITS SOUTHWARD PUSH THURSDAY NIGHT...
BEFORE STALLING ACROSS CENTRAL NORTH CAROLINA JUST SOUTH OF OUR AREA
ON FRIDAY AS IT RUNS INTO UPPER LEVEL RIDGING ACROSS THE SOUTHEAST
STATES. MODELS ARE COMING INTO BETTER AGREEMENT THAT...DESPITE THE
FRONTAL PASSAGE...DEWPOINTS DO NOT DROP OFF ALL THAT MUCH FOR OUR
AREA. AS SUCH...EXPECT THAT THERE WILL BE ENOUGH LOW LEVEL MOISTURE
LEFT OVER TO SUPPORT SCATTERED SHOWER ACTIVITY ACROSS THE MOUNTAINS
AND THE PIEDMONT SOUTH OF HIGHWAY 460 THROUGH THE AFTERNOON AND
EVENING. DRIER HIGH PRESSURE WILL BE WEDGING SOUTHWARD ACROSS THE
PIEDMONT FURTHER NORTH. HIGHS FOR FRIDAY WILL BE COOLER...MAINLY IN
THE 70S MOST LOCATIONS.
SHOWER ACTIVITY WILL INCREASE AGAIN ON SATURDAY AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG THE FRONT. SURFACE HIGH PRESSURE BANKED
AGAINST THE EASTERN FACE OF THE APPALACHIANS WILL PROVIDE ENOUGH
STABILITY TO LIMIT RAINFALL TO SHOWER ACTIVITY FOR MOST OF THE
AREA...ALTHOUGH AN ISOLATED THUNDERSTORM MAY DEVELOP ACROSS THE
MOUNTAIN EMPIRE...AN AREA REMOVED FROM THE INFLUENCE OF THE HIGH. AT
ANY RATE...THE WAVE WILL SHIFT RAPIDLY TO THE NORTH ON SATURDAY...
DRAGGING A SECONDARY COLD FRONT ACROSS OUR AREA DURING THE EVENING.
CANADIAN HIGH PRESSURE BUILDING IN BEHIND THE COLD FRONT WILL BE THE
COOLEST AIR WE HAVE SEEN IN SEVERAL MONTHS...A DEFINITE SIGNAL
THAT AUTUMN IS NOT TOO FAR INTO THE FUTURE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...
FORECAST REMAINS RATHER LOW CONFIDENCE FOR SUNDAY INTO TUESDAY GIVEN
WEST/SW FLOW ALOFT BETWEEN AN UPPER TROUGH TO THE NW AND THE
RESIDUAL AXIS OF DEEPER MOISTURE ALONG THE COAST. LATEST GUIDANCE
STILL RATHER MIXED ON DEGREE OF MOISTURE GETTING PULLED BACK
INLAND/NORTH AHEAD OF THE MAIN TROUGH AS APPEARS SOME SORT OF
LEFTOVER DEFORMATION AXIS MAY LINGER WITH THE COASTAL LOW. THUS KEPT
SOME LOW POPS IN SOUTH/EAST ESPCLY SUNDAY/SUNDAY NIGHT THEN
DECREASING MONDAY FOR NOW. APPEARS DRIER AIR WITH THE STRONGER
SURFACE HIGH BUILDING IN FROM THE NW WILL FINALLY OCCUR BY TUESDAY
BUT EVEN THEN CLOUDS/SHOWERS MAY LINGER/RETURN WITH YET ANOTHER WAVE
PASSING. TEMPS TO COOL BELOW NORMAL THROUGH THE PERIOD WITH MAINLY
60S MOUNTAINS AND LOW 70S EAST FOR HIGHS...AND 50S WEST 60S PIEDMONT
FOR LOWS PENDING CLOUD COVER WHICH COULD MAKE HIGHS EVEN COOLER.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AS OF 800 AM EDT WEDNESDAY...
STUBBORN LOW LEVEL CLOUDS WILL LIKELY REMAIN THROUGH THE
MORNING...MVFR CONDITIONS PERSISTING THROUGH NOON BEFORE
LIFTING INTO THE VFR CATEGORY FOR THE AFTERNOON. WINDS TODAY ARE
EXPECTED TO BECOME SOUTHERLY...PROMOTING THE BREAK UP OF THE
EXISTING CLOUD COVER WHICH HAS BEEN BANKED UP AGAINST THE EAST
SIDE OF THE APPALACHIANS THE LAST SEVERAL DAYS.
A STRONG LOW PRESSURE SYSTEM WILL MOVE INTO THE GREAT LAKES TODAY
IMPACTING AVIATION ROUTES THROUGH DTX-ORD-MSP. A TRAILING COLD
FRONT WILL CROSS STL THIS AFTERNOON...THEN MOVE EAST INTO THE OHIO
AND TN VALLEYS TONIGHT. SCATTERED TO NUMEROUS SHOWERS/STORMS WILL
BE FOUND ALONG THE FRONT...WITH SEVERE STORMS POSSIBLE FROM DTX-
STL. THIS UNSETTLED WEATHER ACTIVITY IS NOT EXPECTED TO REACH THE
MID ATLANTIC REGION UNTIL LATER THURSDAY. UNTIL THEN...FROM THIS
AFTERNOON THROUGH MID DAY THURSDAY...MAINLY VFR CONDITIONS WILL
EXIST. CAN`T RULE OUT A BRIEF PERIOD OF FOG LATE TONIGHT AND EARLY
THURSDAY...BUT IT SHOULD BE PATCHY AND CONFINED MAINLY TO THE
RIVER VALLEYS.
EXTENDED DISCUSSION...
COLD FRONT WILL BRING THREAT OF SHOWERS AND STORMS TO THE AREA
LATE THURSDAY AND THURSDAY NIGHT. FROPA IS EXPECTED THURSDAY
NIGHT. THIS FRONTAL PASSAGE WILL NOT BE A CLEAN SWEEP OF
AIRMASSES...THE MAJORITY OF THE MODELS INDICATING THE FRONT WILL
STALL OVER THE CAROLINAS FRIDAY...FOLLOWED BY DEVELOPMENT OF LOW
PRESSURE ALONG THE FRONT FRIDAY NIGHT...TRACKING NORTHEAST THROUGH
THE REGION SATURDAY. CONFIDENCE IS BEGINNING TO INCREASE THAT AN
EXTENDED PERIOD OF MVFR...POSSIBLY IFR...WILL EXIST FRIDAY NIGHT
INTO SATURDAY. LOW CONFIDENCE FORECAST FOR SUNDAY. HALF THE MODELS
BLOW THE SYSTEM OFF THE COAST CLEARING US FROM THE WEST SUNDAY.
OTHER MODEL SOLUTIONS HANG ON TO THE LOWER LEVEL CLOUDINESS PER
DEVELOPMENT OF LOW LEVEL EASTERLY WINDS OFF THE ATLANTIC...SIMILAR
TO WHAT TRANSPIRED THE FIRST HALF OF THIS WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...CF/JH/PM
SHORT TERM...NF
LONG TERM...JH
AVIATION...PM
AREA FORECAST DISCUSSION
NWS TUCSON AZ
920 AM MST WED SEP 10 2014
.SYNOPSIS...MAINLY DRY CONDITIONS WILL OCCUR THROUGH THURSDAY.
EXPECT ISOLATED TO SCATTERED AFTERNOON AND EVENING THUNDERSTORMS TO
RETURN BY THIS WEEKEND AS MOISTURE INCREASES ACROSS THE AREA. A
WARMING TREND WILL PREVAIL THROUGH FRIDAY FOLLOWED BY MODEST COOLING
EARLY THIS WEEKEND.
&&
.DISCUSSION...A NARROW BAND OF CLOUDINESS EXTENDED FROM THE WHITE
MOUNTAINS SWWD INTO WRN PIMA COUNTY AT THIS TIME. A FEW SHOWERS
PRODUCING MOSTLY SPRINKLES CONTINUED ACROSS FAR WRN PIMA COUNTY.
OTHERWISE...SUNNY SKIES OR MOSTLY SUNNY SKIES PREVAILED ACROSS SE
AZ. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z WERE GENERALLY IN THE
MID-UPPER 50S F. THESE TEMPS WERE ABOUT 5-10 DEGS F LOWER VERSUS 24
HOURS AGO. SURFACE TEMPS VALID 16Z WERE NEARLY IDENTICAL TO THIS
TIME TUE. BLENDED TOTAL PRECIP WATER IMAGERY VALID 1357Z DEPICTED
VALUES RANGING FROM AROUND THREE QUARTERS OF AN INCH ACROSS THE
WHITE MOUNTAINS TO 1.20 INCHES ACROSS WRN PIMA COUNTY.
THE BEST CHANCE FOR MEASURABLE PRECIP INTO THIS EVENING WILL BE
ACROSS THE WHITE MOUNTAINS AS PER THE 10/12Z NAM/GFS...THE 10/12Z
UNIV OF AZ WRF-NAM...AND THE 10/14Z RUC HRRR. HAVE OPTED TO REDUCE
POPS ACROSS THE WHITE MOUNTAINS...BUT HAVE MAINTAINED A SLIGHT
CHANCE OF SHOWERS THERE INTO THIS EVENING. HAVE ALSO MAINTAINED A
SLIGHT CHANCE OF SHOWERS ACROSS FAR WRN PIMA COUNTY INTO THIS
AFTERNOON. DRY CONDITIONS WILL PREVAIL ELSEWHERE THRU TONIGHT. HIGH
TEMPS THIS AFTERNOON ARE FORECAST TO BE JUST A COUPLE OF DEGS OR SO
WARMER VERSUS TUE.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 11/18Z.
ISOLATED -SHRA ACROSS FAR WRN PIMA COUNTY WEST OF KTUS AND ACROSS
THE WHITE MOUNTAINS NE OF KSAD INTO THIS EVENING. OTHERWISE...EXPECT
A FEW TO OCCASIONALLY BKN CLOUDS AT 8-12K FT AGL AND SURFACE WIND TO
BE LESS THAN 10 KTS INTO THURSDAY MORNING. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THERE IS A SLIGHT CHANCE OF AFTERNOON SHOWERS MAINLY
ACROSS THE WHITE MOUNTAINS THROUGH THURSDAY. ISOLATED TO SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL THEN RETURN
STARTING FRIDAY AND CONTINUE INTO EARLY NEXT WEEK AS MOISTURE
INCREASES ACROSS THE AREA. OTHERWISE...20-FOOT WINDS WILL GENERALLY
BE LIGHT AND TERRAIN DRIVEN...EXCEPT FOR STRONG GUSTY OUTFLOWS
ASSOCIATED WITH THUNDERSTORMS.
&&
.PREV DISCUSSION...MINIMAL SHOWERS AND THUNDERSTORMS EXPECTED AGAIN
ON THURSDAY AND AGAIN MOSTLY FOR THE MOUNTAINS AND AREAS ALONG THE
NEW MEXICO BORDER. BY FRIDAY HIGH PRESSURE OVER THE CENTRAL GULF
COAST AND EXTENDING WEST ALONG THE SOUTHERN TIER OF STATES WILL
RESULT IN A SOUTHEAST FETCH ON THE SOUTHERN FLANK OF THE
RIDGE...WHICH WILL HELP TO USHER IN ADDITIONAL MOISTURE FOR A
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. EVEN SO...ONLY
LOOKING AT ISOLATED SHOWERS AND THUNDERSTORMS FOR CENTRAL
ZONES...SUCH AS TUCSON...WITH SCATTERED ACTIVITY FOR AREAS SOUTH AND
EAST OF TUCSON. THIS SET UP WILL GENERALLY CONTINUE THROUGH THE
WEEKEND THROUGH EARLY NEXT WEEK. ANOTHER TROPICAL SYSTEM IS PROGGED
TO REACH THE SOUTHERN TIP OF THE BAJA PENINSULA BY LATE SUNDAY/EARLY
MONDAY...BUT IT IS TOO EARLY TO HANG OUR HATS ON ONE PARTICULAR
SOLUTION...OR TO TRY AND COMPARE THIS NEXT SYSTEM WITH WHAT OCCURRED
WITH NORBERT. THEREFORE...STAY TUNED FOR CONTINUOUSLY UPDATED AND
REVISED FORECASTS BETWEEN NOW AND EARLY NEXT WEEK.
HIGH TEMPERATURES WILL GENERALLY RANGE FROM 1 TO 3 DEGS BELOW NORMAL
TODAY...THEN 1 TO 3 DEGS ABOVE NORMAL FOR THURSDAY AND FRIDAY.
THEREAFTER...HIGHS HOVERING NEAR NORMAL. LOWS WILL BE NEAR TO
SLIGHTLY ABOVE NORMAL THURSDAY MORNING...THEN 4 TO 6 DEGS ABOVE
NORMAL EACH MORNING THEREAFTER.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
PREVIOUS DISCUSSION...MOLLERE
AREA FORECAST DISCUSSION
NWS PADUCAH KY
323 PM CDT Wed Sep 10 2014
.SHORT TERM...(Tonight through Friday night)
Issued at 323 PM CDT WED SEP 10 2014
The showers are still trying to dissipate over southern Illinois,
and now a tiny heavy shower has develop near KSAR in the last
scan or two. The latest HRRR indicates that there may be some
heavier convective elements with this pesky band of showers, as it
moves eastward toward the EVV Tri State late this afternoon.
Widespread cloud cover has stunted surface-based instability
today, and this may help keep the severe weather threat in check
as we move into this evening. Model soundings from southern
Illinois and southwest Indiana reveal very weak lapse rates, and
overall instability. There is decent low-level shear, possibly
enough to support a few rotating updrafts. The low-level shear
will weaken through the evening, and there is little shear above 3
km. Cannot rule out a stray severe thunderstorm, especially if it
can display supercellular characteristics. Damaging winds still
appear to be the primary concern, but large hail and a brief
tornado cannot be ruled out.
Precipitable water values are well above 2 inches, and this could
lead to some torrential rainfall. Generally followed HPC QPF
through Thursday, and this yields 1.5-2" over much of the area,
with the possible exception of the far southeast corner of the
forecast area. 1-hour and 3-hour Flash flood Guidance is well over
2", so will not be issuing a Flash Flood Watch at this time. Some
nuisance flooding in low-lying and poorly draining areas is
possible, but major problems are not expected. The heaviest rains
will be waning over the southern half of the area toward sunrise.
Still not sure when/where convective initiation will occur, but
the latest HRRR runs have been consistent and developing scattered
convection across northern portions of southeast Missouri into
southern Illinois by 00Z. Convection currently developing along
the cold front from west central Illinois into central Missouri is
moving east and should not pose any immediate concern for our
region, but figure that the convection will fill in between it and our
scattered convection through the evening.
Will keep some decent PoPs in the southeast Thursday morning, but
it should be drying out over most areas in the afternoon. Thursday
night and Friday morning should be dry, but as the next rather
sharp upper-level storm system rotates eastward out of the
central/northern Plains, would not be surprised to see some
showers develop, as moisture is drawn back northward over the
shallow Canadian airmass. This would primarily be in the south
Friday afternoon, and then throughout the area Friday night. Still
don`t think there will be much precipitation, but a slight chance
of showers seems reasonable for both periods.
As for temperatures, stayed close to the consensus of all guidance
for lows tonight with the frontal passage. With clouds,
precipitation and cool advection, went under guidance in the
southeast Thursday. Went near consensus for lows Thursday night,
and then went below guidance Friday and near or just above it Friday
night.
.LONG TERM...(Saturday through Wednesday)
Issued at 323 PM CDT WED SEP 10 2014
Surface high pressure will build into the area on Saturday,
providing much drier air and lowering temperatures. The center of
the high will pass over the Great Lakes region and then move into
the New England states. Our region should remain dry through the
weekend though as weak high pressure continues to stay situated over
us.
Models try and bring a front into the area on Monday. The front
weakens substantially as it arrives Monday into Monday night, so
chances for precipitation appear minimal at this time but cloud
cover should increase. Most of the upper level dynamics and moisture
look to be to the north of our area. However, we will have to watch
Monday night, as a few of the GFS ensemble members and the 12Z Euro
are hinting that this front could produce some light precipitation,
especially in our northwestern counties. Even the operational GFS
indicates lower level moisture increasing by Monday night.
For Tuesday, models differ on the degree of dry air filtering into
the area, in association with the area of high pressure that moves
toward us. The 12Z GFS is much more robust in scouring out the
moisture while the 00Z ECMWF seems to keep plenty of moisture
lingering until Wednesday. The 12Z run of the ECMWF is a bit more
pronounced with drying us out now but still not as much as the GFS.
Nevertheless, it looks like we`ll be dry on Tuesday. On Wednesday,
the GFS starts to bring better moisture back into the area from the
west and even hints at possible precipitation chances out in SEMO as
well. However, the 12Z run was the only run that was this quick in
bringing precipitation back in and even the 12Z ECMWF was dry.
Temperatures will be coolest on Saturday and remain in the 70s for
the majority of the extended period. There might be a few places
that reach in the lower 80s by next week. Lows will generally be in
the 50s but some upper 40s might be attainable on Saturday night
especially in the north.
&&
.AVIATION...
Issued at 1248 PM CDT WED SEP 10 2014
MVFR ceilings should lift to VFR levels in the next hour or two at
KEVV and KOWB. The band of showers that has been slowly moving
toward the area this morning, is weakening as expected, and should
have no impact on the terminals this afternoon. South southwest
winds will gust well over 20kts at times this afternoon at all sites.
Extensive cloud cover playing havoc with the destabilization
process, so the timing and location of convective initiation is
questionable. Given the forcing expected tonight, will keep
general onset from previous forecast. There could be several hours
of TS at all sites this evening into the early morning hours. The
cold front will pass the terminals late tonight, and IFR or LIFR
ceilings are a good bet behind the front. MVFR showers are also
likely through at least sunrise behind the front. Not sure how
much the ceilings will be able to lift/break up by 18Z Thursday.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...LAKE WIND ADVISORY until 6 PM CDT this evening FOR ILZ075>078-
080>094.
MO...LAKE WIND ADVISORY until 6 PM CDT this evening FOR MOZ076-086-
087-100-107>112-114.
IN...LAKE WIND ADVISORY until 6 PM CDT this evening FOR INZ081-082-
085>088.
KY...LAKE WIND ADVISORY until 6 PM CDT this evening FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...CW
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
308 PM CDT WED SEP 10 2014
.SHORT TERM...
RATHER MOIST AIR MASS IN PLACE ON STEADY-STATE ONSHORE FLOW AROUND
PERIPHERY OF BERMUDA RIDGE. MID LEVELS HAVE WARMED TO LIMIT THE
DEPTH OF CONVECTIVE COVERAGE THROUGH AT LEAST 89F CONVECTIVE
TEMPERATURES...OVERCOMING 500 MB WARM LAYER AROUND 91F SURFACE
TEMPERATURE. RESULT WILL BE SHORT-LIVED SLOW-MOVING BUT EFFICIENT
SHOWERS AND BRIEF THUNDERSTORMS FORMING MAINLY ON OUTFLOW
INTERSECTIONS THAT ARE PROMINENTLY DISPLAYED ON RADAR
PRESENTATION. THIS CONVECTION SHOULD DISSIPATE SHORTLY AFTER
SUNSET. MEANWHILE...EASTERLY WAVE CURRENTLY TRAVERSING THE
NORTHEAST GULF UNDER THE RIDGE WILL SERVE AS A FOCUS FOR DEEPER
LOW LEVEL MOISTURE THURSDAY AND FRIDAY. THIS IS CONSISTENT WITH
THE WRF AND HRRR MODEL RUNS FOR THURSDAY AFTERNOON AS WELL AS THE
OTHER LONGER RANGE MODELS. WILL INDICATE HIGHER RAIN CHANCES
CLOSER TO THE COAST AND TAPER DOWNWARD FARTHER INLAND THURSDAY.
WITH FRONTAL ZONE SETTLING INTO THE AREA FRIDAY...WILL BE
DIFFICULT TO DISTINGUISH FAVORED AREAS FOR FOCUSED RAINFALL DUE TO
VARIOUS CAUSES/PROCESSES...SO WILL SIMPLY GO 50 PERCENT ENTIRE
AREA. IF DEEPER GULF MOISTURE ALIGNS IN CONVERGENT BANDS...THEN
SOME LOCATIONS MAY UNDERGO SOME SHORT DURATION OF TRAINING WHICH
MAY ACCUMULATE MORE RAINFALL...MOSTLY LIKELY CLOSER TO THE COAST
THOUGH FRONTAL ZONE MAY COMPLICATE MATTERS.
.LONG TERM...
MODELS ALL AGREE IN STALLING THE FRONT ALONG OR CLOSE TO THE GULF
COAST SATURDAY AS UPPER SUPPORT SHUNTS EASTWARD. THIS DIFFERS FROM
MAN-MACHINE MIX THAT CONTINUES TO INDICATE A DEEPER FRONTAL
ADVANCE WELL INTO THE GULF BEFORE STALLING. ASSOCIATED CONVECTION
AND OUTFLOWS MAY INDUCE THE SURFACE FRONT SOUTHWARD BUT THE AIR
MASS WOULD BE GREATLY MODIFIED AND RUNNING MOSTLY ON RAIN COOLED
DENSITY. IN COORDINATION WITH SURROUNDING OFFICES...WE WILL BE
INDICATING WARMER THAN GUIDANCE TEMPERATURES FOR MORNING LOWS
SUNDAY AND MONDAY IN DEFERENCE TO NATIONAL GUIDANCE...PARTICULARLY
IF TROPICAL WAVE INFLUENCES BECOME INVOLVED THIS FAR SOUTH. WHILE
ON THE SUBJECT...THE NHC HAS HIGHLIGHTED A YELLOW OUTLOOK AREA
FROM THE BAHAMAS WESTWARD ACROSS THE NORTH GULF. THIS IS A
TROPICAL WAVE THAT SHOULD REMAIN OPEN WHILE TRAVERSING UNDER THE
UPPER RIDGE. SEVERAL MODELS INDICATE SUCH A SCENARIO...ONLY THE
CANADIAN RUN SHOWS A CLOSED LOW STRUCTURE THAT DOES NOT LOOK
ATTAINABLE GIVEN CURRENT PATTERN IN PLACE. NONETHELESS...THIS
FEATURE SHOULD SERVE TO BRING GREATER FOCUS FOR RAINFALL POTENTIAL
OVER THE WEEKEND...PARTICULARLY AS IT INTERACTS WITH ANY
STATIONARY FRONTAL FOCUS. RAINFALL POTENTIAL CAN BECOME PRONOUNCED
AND OF CONSIDERABLY LONG DURATION WHEREVER THE FRONT AND WAVE
INTERSECT. THE KEY IS WHETER IT WILL BE OFF THE COAST OR JUST
INLAND ENOUGH TO PRESENT A FLOOD THREAT FOR SOME COASTAL
COMMUNITIES. THIS WILL HAVE TO BE CLOSELY MONITORED OVER THE NEXT
FEW DAYS.
&&
.AVIATION...
VFR CONDITIONS TO PREVAIL THROUGH AT LEAST 09Z. SOME PATCHY
RADIATIONAL FOG MAY DEVELOP AT KMCB TOWARDS DAYBREAK THURSDAY THAT
MAY BRING BRIEF IFR CIGS/VSBY BUT MOST OTHER LOCATIONS SHOULD
REMAIN VFR OVERNIGHT. CONVECTION REMAINS ISOLATED IN COVEARAGE
THIS AFTERNOON AND SHORT-LIVED. GUST POTENTIAL IS AROUND 20 KT
RANGE REMAINDER OF THIS AFTERNOON AND PROJECTED 25-30 KT RANGE
THURSDAY.
&&
.MARINE...
BERMUDA RIDGE FLOW PATTERN SHOULD MAINTAIN RELATIVELY LIGHT WINDS
AND LOW SEAS FOR THURSDAY AND FRIDAY. A COLD FRONT MOVING FROM
THE NORTH IS LIKELY TO STALL BEFORE REACHING THE COAST LATE FRIDAY
OR EARLY SATURDAY. MEANWHILE...AN EASTERLY WAVE WILL BE TRAVERSING
THE NORTH GULF FRIDAY AND SATURDAY AND SHOULD INTERACT WITH THE
FRONTAL ZONE TO POTENTIALLY PRODUCE GREATER COVERAGE OF TROPICAL
SHOWERS AND THUNDERSTORMS IN THE NEAR COASTAL WATERS AND SOUNDS
THIS WEEKEND. SEAS SHOULD REMAIN LESS THAN 2 FEET THROUGH MONDAY
EVENING.
&&
.DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 72 90 72 89 / 10 30 20 50
BTR 73 91 73 90 / 10 30 20 50
ASD 74 90 73 90 / 10 30 20 50
MSY 77 90 77 90 / 10 40 20 50
GPT 76 89 75 90 / 20 40 20 50
PQL 73 90 72 89 / 20 40 20 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
24/RR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
153 PM EDT WED SEP 10 2014
.UPDATE...
ISSUED AT 1149 AM EDT WED SEP 10 2014
GENERALLY MINOR TWEAKS TO THE GOING FORECAST...LARGELY WITH PINNING
DOWN THE LOCATIONS OF THE HEAVIEST PRECIPITATION AND THEN WINDS FOR
THIS AFTERNOON AND TONIGHT BEHIND THE LOW.
AS FOR THE RAIN...ESSENTIALLY SEEING TWO AREAS OF
PRECIPITATION...ONE OVER THE EAST ALIGNED WITH THE BROAD 850-500MB
WARM AIR ADVECTION LIFTING TO THE NORTHEAST AHEAD OF THE LOW
CENTERED OVER SOUTH CENTRAL WISCONSIN. EXPECT THAT AREA TO CONTINUE
PUSHING TO THE NORTHEAST THROUGH THE DAY AND LARGELY DEPARTING BY
LATE AFTERNOON. THE SECOND AREA IS FARTHEST TO THE WEST AND TIED TO
THE 850-700MB FGEN AREA TO THE NORTHWEST OF THE MID LEVEL LOW.
OBSERVER REPORTS INDICATE THIS AREA OF RAIN PRODUCING AROUND
0.5-0.75IN EVERY THREE HOURS AND THAT MATCHES DUAL POL INSTANTANEOUS
PRECIP RATES. ALTHOUGH THIS AREA HAS BEEN PIVOTING AND SLOW TO MOVE
THIS MORNING...IT IS EXPECTED TO SHIFT MORE TO THE EAST-NORTHEAST
THIS AFTERNOON AS THE LOW QUICKLY MOVES NORTHEAST THROUGH NORTHERN
LAKE MICHIGAN. STILL HAVE THE FLOOD WATCH IN PLACE AND THAT SEEMS
REASONABLE OVER THE WEST (WITH THE ADDED PRECIP FROM OVERNIGHT
PUSHING TOTALS OVER 2 INCHES IN SOME LOCATIONS). FROM
MARQUETTE/DICKINSON COUNTY EAST...THINK THE POTENTIAL FOR FLOODING
IS PRETTY LIMITED BUT WILL LEAVE WATCH IN PLACE AT THIS TIME.
FINALLY FOR WINDS...MAIN ADJUSTMENTS WERE FOR AREAS OVER THE EAST
AND NEAR LAKE MICHIGAN. EXPECT THE COMBINATION OF STRONG COLD AIR
ADVECTION BEHIND THE LOW AND QUICK PRESSURE RISE TO LEAD TO GALES
AND HAVE ISSUED A GALE WARNING FOR OUR LAKE MICHIGAN ZONES. DO HAVE
A LITTLE CONCERN THAT GUSTS WILL BE NEAR 40-45MPH BRIEFLY LATE THIS
AFTERNOON INTO THE EVENING NEAR THE LAKE SUPERIOR SHORELINE AND
POTENTIALLY AT TIMES ELSEWHERE INLAND. THE OTHER AREA WAS OVER THE
KEWEENAW PENINSULA...ALTHOUGH THE FORECAST WAS IN DECENT
SHAPE...LATEST OBS AT KP59 INDICATE WINDS GUSTING TO NEAR WIND
ADVISORY CRITERIA. WITH THE CENTRAL LAKE SUPERIOR BUOY GUSTING
ABOVE 40KTS AND OTHER SITES NEAR WIND ADVISORY CRITERIA...WILL
ISSUE A WIND ADVISORY FOR KEWEENAW AND NORTHERN HOUGHTON COUNTIES
THROUGH THE EVENING HOURS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 533 AM EDT WED SEP 10 2014
LIGHT TO AT TIME HEAVY RAIN CONTINUES TO FALL OVER THE W THIRD OF
UPPER MI THIS MORNING...ASSOCIATED WITH THE SFC TROUGH THAT PUSHED
OVERHEAD EARLY THIS MORNING THE 500MB SHORTWAVE CROSSING WI...AND
THE DEEPENING SFC LOW RIDING UP ALONG THE TROUGH NEARING FROM IA.
THE LATEST SATELLITE AND RUC ANALYSIS SHOWS THIS INITIAL N SWATH OF
MOISTURE EJECTING NE ACROSS THE CWA...WITH THE EFFECTS OF THE SW TO
NE 100KT 250MB JET NEARING FROM THE PLAINS. THE SECONDARY AREA OF
CLOUDS WILL BE IMPACTING THE E HALF OF THE CWA LATER THIS MORNING
AND INTO THE AFTERNOON HOURS. EXACT RAINFALL TOTALS REMAIN TRICKY AS
THERE ARE 2 AREAS OF THOUGHT. THE LATEST 06Z NAM PAINTS AN
ADDITIONAL 1-2IN OVER CENTRAL AND E UPPER MI LATE THIS MORNING
THROUGH EARLY THIS AFTERNOON. HOWEVER...THE 00Z GFS IS PUSHING MUCH
OF THE MOISTURE JUST TO OUR E. HAVE GONE WITH A MIDDLE OF THE ROAD
SOLUTION FOR THE MOMENT...KNOWING THAT CONVECTION TO THE SOUTH COULD
STILL HURT THE INFLOW OF MOISTURE UP OUR WAY. STILL...ADDITIONAL
SHOWERS CROSSING THE CWA THIS AFTERNOON WITH BE FACED WITH STIFF N
ONSHORE FLOW...RESULTING IN A SLOWER N PROGRESSION AND OVERALL
UPSLOPE ENHANCEMENT. SEE THE HYDROLOGY SECTION FOR MORE DETAILS
ABOUT PRECIPITATION FOR THE REST OF TODAY. RAIN/RAIN SHOWERS WILL
CONTINUE THROUGH TONIGHT...MAINLY ACROSS THOSE UPSLOPE AREAS OF
CENTRAL UPPER MI. ADDITIONAL RAINFALL MAY ADD UP TO 0.25IN OR MORE
ACROSS THE HURON MOUNTAINS. FCST MODELS ARE CONTINUING TO GO WITH
THE SFC LOW TRACKING ACROSS N LOWER MI LATE THIS AFTERNOON...BEFORE
EXITING INTO S ONTARIO AND W QUEBEC LATE THIS EVENING.
TEMPERATURES WILL REMAIN TRICKY...AS THEY FALL W AND STILL RISE A
COUPLE OF DEGREES AFTER SUNRISE E. KEPT THE WIND FCST VERY SIMILAR
TO THE LAST COUPLE OF DAYS...WITH N-NNW GUSTS NEARING 35KTS FROM
AROUND 18Z TODAY TO 08Z TONIGHT. AN SPS MAY BE NEEDED FOR THE W HALF
AND HIGHER TERRAIN OF THE KEWEENAW PENINSULA...OR LOW END WIND
ADVISORY TO HIGHLIGHT THE STRONG WINDS ON TOP OF SATURATED SOILS
THAT MAY MORE EASILY UPROOT TREES THANKS TO THE ABUNDANT LEAVES. AS
FOR THE OVERNIGHT HOURS...EXPECT SLOWLY DIMINISHING WINDS LATE AND
COLD AIR TO FILTER IN WITH 850MB TEMPS OF -2 TO +4C BY DAYBREAK
THURSDAY. DEPENDING ON HOW FAST RAIN CAN GET OUT OF THE INTERIOR
AREAS ALONG THE WI BORDER...MID 30S LOWS WILL NOT BE OUT OF THE
QUESTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 359 AM EDT WED SEP 10 2014
MAIN FCST CONCERNS IN THE LONG TERM FOCUS ON HOW QUICKLY ON THU CLDS
AND SHOWERS ASSOCIATED WITH THE WED LO PRES WL EXIT THE CWA...TEMPS
AND THE POTENTIAL FOR FROST ON THU NGT AND THEN ON POPS ACCOMPANYING
THE PASSAGE OF ANOTHER DISTURBANCE THRU THE LOWER LKS ON FRI INTO
SAT. SINCE AN UPR TROF WL DOMINATE ERN NAMERICA THRU NEXT WEEK...
EXPECT BLO NORMAL TEMPS TO PREVAIL DURING THE EXTENDED PERIOD.
THU...AS DEPARTING LO PRES OVER FAR SW QUEBEC AT 12Z THU SHIFTS TO
THE ENE...STEADY N LLVL FLOW IS PROGGED TO WEAKEN AND BECOME MORE
ACYC UNDER GENERAL DEEP LYR QVECTOR DVGC LEFT IN THE WAKE OF THE
EXITING SHRTWV AND RDG AXIS EXPANDING TO THE E OF SFC HI CENTER IN
THE NRN PLAINS. EXPECT PLENTY OF CLDS IN THE MRNG WITH SHOWERS
MAINLY NEAR LK SUP ASSOCIATED WITH CHILLY LINGERING CYC FLOW OVER
THE RELATIVELY WARM LK SUP WATERS. BUT WITH INCRSG SUBSIDENCE/ACYC
FLOW IN THE PRESENCE OF DAYTIME HEATING...EXPECT THE SHOWERS TO
DIMINISH AND THE CLD PATTERN TO SHIFT TO MORE INLAND SC COVERAGE
UNDER THE H85 THERMAL TROF AND SUBSIDENCE INVRN SINKING TOWARD
H85-9. H85 TEMPS IN THE ZERO TO -2C RANGE WL SUPPORT WELL BLO NORMAL
HI TEMPS MAINLY IN THE UPR 40S/50S...COOLEST OVER THE HIER TERRAIN
OF THE NW HALF.
THU NGT...UNDER BLDG HI PRES WITH LOSS OF DAYTIME HEATING...EXPECT
LINGERING SC TO DSPT IN THE EVNG AND GIVE WAY TO AT LEAST A PERIOD
OF MOCLR SKIES AND LGT WINDS. WITH PWAT UNDER 0.5 INCH...TEMPS
SHOULD FALL OFF STEADILY. THE ONE LIMITING FACTOR WL BE HOW QUICKLY
HI CLDS IN ADVANCE OF SHRTWV MOVING THRU THE NRN PLAINS WL INVADE
THE UPR LKS. SUSPECT THE COLD SPOTS OVER THE INTERIOR WL SEE TEMPS
FALLING AOB 32...BUT WL HOLD OFF ON ANY KIND OF FREEZE WATCH/FROST
HEADLINE GIVEN ACTIVE SHORT TERM...MARGINALLY LO ENUF FCST TEMPS AND
COVERAGE OF THOSE REALLY LO TEMPS UNDER SOME INCRSG HI CLDS.
FRI THRU SAT...ALTHOUGH THERE IS GOOD MODEL AGREEMENT ON THE TIMING
AND TRACK OF A FAIRLY VIGOROUS SHRTWV THAT IS FCST TO MOVE E FM THE
NRN ROCKIES ON THU AFTN THRU THE NCENTRAL PLAINS AND ACROSS THE
LOWER LKS FRI NGT/SAT...THERE ARE SOME FAIRLY LARGE DIFFERENCES IN
THE MSLP FIELDS AND QPF. THE 09/12Z ECWMF CONTINUES TO BE THE MODEL
THAT SHOWS THE MORE IMPRESSIVE PRES FALL. WITH A DEEPER SFC
REFLECTION...THE ECMWF ALSO SHOWS MORE EXPANSIVE MID LVL MSTR/PCPN
EXTENDING INTO ALL OF UPR MI DURING FRI NGT/SAT MRNG. GIVEN THE
POSITIVE TILT TO THE SHRTWV....EXPANSIVE HI PRES THAT IS FCST TO
EXTEND FM THE NRN PLAINS INTO THE UPR LKS IN ADVANCE OF THIS SHRTWV
AND DRY/STABLE NATURE OF THE ANTECEDENT AIRMASS /PWAT AOB 0.5 INCH
WITH STRONG SUBSIDENCE INVRN BTWN H8-7/...SUSPECT THE NON-ECMWF
MODELS SHOWING LESS SFC RESPONSE ARE ON THE RIGHT TRACK. HAVE THUS
CHOSEN TO MAINTAIN ONLY LO CHC POPS...HIEST OVER THE SRN CWA CLOSER
TO THE SHRTWV TRACK/AREA OF SHARPER DEEP LYR QVECTOR CNVGC. THICKER
CLDS/THESE POPS WL ARRIVE ON FRI AFTN AS THE DISTURBANCE SLIDES
INTO THE UPR MS RIVER VALLEY. ONCE THE SHRTWV PUSHES TO THE E ON SAT
MRNG...TRAILING SHRTWV RDG/DRIER AIRMASS WL BRING A RETURN TO DRY
WX/CLRG. WITH H85 TEMPS IN THE ZERO TO -2C RANGE DURING THIS
TIME...THE WX WL BE UNSEASONABLY COOL. IF SKIES CLR FAST ENUF LATE
FRI NGT...NOT OUT OF THE QUESTION THERE COULD BE SOME FROST OVER THE
INTERIOR W ARND SUNRISE ON SAT.
EXTENDED...AFTER A DRY PERIOD ASSOCIATED WITH SFC HI PRES PASSING
THRU THE LOWER LKS ON SAT NGT...ANOTHER CNDN SHRTWV DIGGING THRU THE
MEAN UPR TROF CENTERED OVER HUDSON BAY AND INTO THE NCENTRAL CONUS
WL BRING A CHC OF MORE SHOWERS FOR SUN THRU MON. THIS DISTURBANCE WL
BE MSTR DEPRIVED...SO NO HEAVY RA IS LIKELY. HI PRES MOVING E UNDER
THE RISING HGTS IN THE WAKE OF THIS DISTURBANCE SHOULD BRING A
RETURN OF DRY WX FOR TUE. WITH THE MEAN TROF IN PLACE...TEMPS ACRS
UPR MI WL AVG BLO NORMAL DURING THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 152 PM EDT WED SEP 10 2014
A STRONG LOW PRESSURE SYSTEM MOVING NORTHEAST FROM SOUTH CENTRAL
WISCONSIN THROUGH NORTHERN LOWER MICHIGAN AND THEN INTO QUEBEC WILL
BRING GUSTY NORTH-NORTHEAST WINDS THROUGH TONIGHT. MODERATE RAIN
WILL CONTINUE OVER THE NEXT FEW HOURS BEFORE TRANSITIONING TO LAKE
EFFECT RAIN AT ALL THREE SITES FOR TONIGHT. THE ABUNDANT MOISTURE
WITH THIS SYSTEM WILL PRODUCE IFR CEILINGS THIS AFTERNOON WHICH
WILL GRADUALLY RISE TO MVFR TONIGHT INTO THURSDAY MORNING AS THE LOW
MOVES AWAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 AM EDT WED SEP 10 2014
AS A DEEP LO PRES MOVES NE THRU THE UPPER MIDWEST AND ACROSS
NORTHERN LOWER MI THIS EVENING ON ITS WAY INTO SE CANADA
TONIGHT...THE NE GALES AFFECTING WESTERN LAKE SUPERIOR WILL SPREAD E
OVER THE REST OF THE LAKE. EXPECT NNE GALES AS HI AS 40-45 KTS TODAY
INTO TONIGHT BEFORE THE LO PRES SHIFTS FAR ENOUGH TO THE E AND THE
GALES DIMINISH W TO E TONIGHT. AS HI PRES BUILDS TOWARD LAKE SUPERIOR
FROM THE PLAINS ON THU...LINGERING N WINDS UP TO 25-30 KTS IN THE
MORNING WILL DIMINISH W-E TO UNDER 15-20 KTS BY THE EVENING.
RELATIVELY LIGHT WINDS UNDER 20 KTS WILL THEN DOMINATE THRU THE
WEEKEND UNDER A RELATIVELY WEAK PRES GRADIENT.
&&
.HYDROLOGY...
ISSUED AT 426 AM EDT WED SEP 10 2014
RAINFALL OVER THE W THIRD OF UPPER MI HAS BEEN CONVECTIVELY
ENHANCED...WITH RAINFALL RATES BRIEFLY RISING TO NEAR 6IN PER HOUR.
WITH THE QUICK MOVEMENT TO THE N JUST OVER 20KTS THAT AMOUNT WAS NOT
REALIZED. RADAR ESTIMATES THROUGH 08Z HAVE THE HIGHEST AMOUNTS OVER
NW GOGEBIC AND ALONG THE E ONTONAGON/W HOUGHTON COUNTIES...WITH 1.5
TO 2.25IN. SOME LOCAL RIVERS CONTINUE TO RESPOND TO THE RAINFALL A
FEW DAYS AGO...AND ARE RISING AT AN INCREASED RATE DO TO THE CURRENT
RAIN. SPECIFICALLY THIS INCLUDES THE SOUTH BRANCH OF THE ONTONAGON
RIVER AT EWEN /WHICH GIVEN THE TREND WILL SEE A SLOW RISE FOR THE
NEXT SEVERAL DAYS/. THE MIDDLE BRANCH OF THE ONTONAGON RIVER AT
PAULDING IS ALSO SLOWLY ON THE RISE.
OTHERWISE AN AVERAGED 0.5IN HAS FALLEN W OF A LINE FROM
IRON RIVER TO BARAGA. LITTLE RAIN HAS FALLEN E OF THIS LINE...WHICH
WILL CHANGE OVER THE NEXT COUPLE OF HRS AS ADDITIONAL SHOWERS NEAR
FROM WI. THUNDERSTORMS ARE MINIMAL OVER WI...AND PRECIP IS SLOWER
THAN ORIGINALLY ANTICIPATED. HAVE BACKED OFF ON THE STORM TOTAL
PRECIP OVER THE E THIRD OF THE FCST AREA AS A RESULT. EXPECT THE
TRADITIONAL URBAN/SMALL STREAM FLOODING TO BE A SIGNIFICANT
POSSIBILITY IN THE TYPICAL POOR DRAINAGE AREAS OF ESC IF A PERIOD OF
HEAVIER DOWNPOURS DEVELOP WITH RAINFALL RATES CLOSE TO AN 0.5-1.0
INCH PER HOUR. N CNTRL UPPER MI WILL STILL LIKELY SEE SOME UPSLOPE
LAKE ENHANCEMENT TODAY-TONIGHT. THE FLOOD WATCH REMAINS POSTED FOR
MUCH OF W AND CENTRAL UPPER MI FOR TODAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FLOOD WATCH UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
MIZ001>006-009>013-084.
WIND ADVISORY UNTIL 2 AM EDT THURSDAY FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING FROM 8 PM THIS EVENING TO 8 AM EDT THURSDAY FOR
LSZ251-267.
GALE WARNING UNTIL 5 AM EDT THURSDAY FOR LSZ246>250-265-266.
GALE WARNING UNTIL 4 AM EDT THURSDAY FOR LSZ243>245-264.
GALE WARNING UNTIL 2 AM EDT /1 AM CDT/ THURSDAY FOR LSZ240>242-
263.
GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THURSDAY FOR LMZ221-248-250.
&&
$$
UPDATE...SRF
SHORT TERM...KF
LONG TERM...KC
AVIATION...SRF
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
111 PM CDT WED SEP 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT WED SEP 10 2014
MODERATE TO HEAVY RAIN CONTINUES OVER MUCH OF EAST CENTRAL MN AND
WEST CENTRAL WISCONSIN. ALTHOUGH THE GREATER MOISTURE TRANSPORT HAS
EXITED TO THE SOUTHEAST OF THE AREA...FAIRLY STRONG MID LEVEL
FRONTOGENESIS REMAINS OVER TWO SPECIFIC AREAS OF THE CWA. ONE OVER
EAST CENTRAL MN AND NORTHWEST WISCONSIN AND THE OTHER DEVELOPING TO
THE SOUTHEAST...MOVING NOW INTO WEST CENTRAL WISCONSIN. THE RUC AND
NAM SHOW THIS GRADUALLY WEAKENING AND LIFTING OFF TO THE EAST
DURING THE MORNING. THIS SHOULD TAKE THE RAIN WITH IT. THE THREAT
OF PONDING WATER REMAINS MAINLY ACROSS WEST CENTRAL WISCONSIN INTO
THE MORNING. COLLABORATION WITH SURROUNDING OFFICES DID YIELD THE
CONTINUATION OF THE FLOOD WATCH INTO WEST CENTRAL WISCONSIN.
TODAYS HIGH TEMPERATURES WILL LIKELY OCCUR THIS MORNING AS WELL.
THEY MAY CONTINUE TO DROP OFF THROUGH MID MORNING OR SO BEFORE
LEVELING OFF INTO THE AFTERNOON. STRONG NORTH WINDS RE EXPECTED TO
DEVELOP EAST AS LOW LEVEL CAA SPREADS OVER THE REGION.
CLOUDS ARE EXPECTED TO HANG TOUGH OVER MUCH OF THE AREA INTO THE
NIGHT. THERE IS SOME INDICATION THAT IN THE WAKE OF THE
TROUGH...SUBSIDENCE COULD BE STRONG ENOUGH TO ERODE THE LOWER CLOUD
COVER. WINDS WILL SLOWLY DIMINISH AS THE LOW CONTINUE TO LIFT
EAST/NORTHEAST INTO THE NIGHT. IT SHOULD COOL RAPIDLY IF BREAKS DO
DEVELOP INTO THE NORTH CENTRAL CWA DURING THE NIGHT. SOME UPPER 30S
POSSIBLE WHERE THIS OCCURS. READINGS IN THE LOWER 40S SHOULD REMAIN
ELSEWHERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 327 AM CDT WED SEP 10 2014
THE LONG TERM FORECAST WILL FEATURE THE PASSAGE OF A SHORTWAVE
TROUGH AT THE BEGINNING OF THE PERIOD...FOLLOWED BY BRIEF SEMI-
ZONAL FLOW OVER THE WEEKEND...AND THEN A PATTERN TRANSITION TO
WESTERN RIDGING AND EASTERN TROUGHING THROUGH THE FIRST HALF OF
NEXT WEEK.
ON THURSDAY...A BROAD SURFACE HIGH BECOMES ESTABLISHED ACROSS THE
NATION/S MIDSECTION...WHILE A WEAK SHORTWAVE SLIDES EAST/SOUTHEAST
ACROSS THE AREA FROM THE NORTHERN/CANADIAN ROCKIES. WHILE THE
BETTER FORCING AND MORE PLENTIFUL MOISTURE WILL LIE SOUTH OF THE
FORECAST AREA...COULD SEE A FEW SHOWERS SNEAK INTO SOUTHERN MN AND
WEST CENTRAL WI LATE THURSDAY NIGHT AND FRIDAY. TEMPERATURES WILL
BE COOL...WITH HIGHS IN THE 50S ON THURSDAY AND FRIDAY...AND LOWS
DIPPING INTO THE MID TO UPPER 30S. DEPENDING ON HOW THE CLEARING
GOES AND WINDS...COULD POSSIBLY SEE SOME FROST ON SATURDAY
MORNING.
SATURDAY LOOKS TO HAVE THE HIGHEST POTENTIAL TO BE AN ENTIRELY DRY
DAY...AS SURFACE HIGH PRESSURE PREVAILS AND IN THE ABSENCE OF ANY
MID/UPPER DISTURBANCES.
SUNDAY BRINGS THE ARRIVAL OF WEAK SHORTWAVE ENERGY IN THE BASE OF
THE MANITOBA/ONTARIO TROUGH. MOISTURE AND FORCING ARE THE MOST
ROBUST NORTH AND EAST OF THE FORECAST AREA...BUT SUFFICIENT TO
WARRANT 20 POPS LOCALLY.
ON MONDAY...THINGS START TO DRY OUT WITH THE PATTERN EVOLUTION TO
WESTERN RIDGING. OVERALL...SHOULD BE DRY WITH SLIGHTLY BELOW
NORMAL TEMPERATURES THROUGH MID-WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 111 PM CDT WED SEP 10 2014
LOW MVFR CEILINGS WILL IMPROVE TO VFR FROM NW TO SE DURING THE
LATE AFTERNOON AND EVENING HOURS AS A LOW PRESSURE SYSTEM NEAR
KGRB CONTINUES TO MOVE NORTHEAST. MAIN CHANGE FROM THE PREVIOUS
SET WAS TO DELAY THE IMPROVEMENT TO VFR BY A FEW HOURS. THE ONE
AREA THAT MAY STILL END UP BEING TOO QUICK WITH THE IMPROVEMENT IS
KEAU WHERE THE LOW LEVEL CYCLONIC FLOW PERSISTS THROUGH THE NIGHT.
VFR DAY ON THURSDAY AND THERE MAY BE SOME SPRINKLES OR LIGHT RAIN
OVER WEST CENTRAL AND SOUTHWEST MN AS A WEATHER DISTURBANCE DROPS
SOUTHWARD THROUGH THE NORTHERN AND CENTRAL PLAINS. NORTH WINDS
THIS AFTERNOON FROM 15 TO 20 KNOTS WITH GUSTS TO 25 KNOTS...WILL
DIMINISH TO 10 KNOTS OR LESS TONIGHT. NORTH WINDS 10 TO 15 KNOTS
ON THURSDAY.
KMSP...MVFR CEILINGS FORECAST TO PERSIST INTO EARLY THIS EVENING
WHICH IS A FEW HOURS LATER THAN THE PREVIOUS TAF. VFR THEREAFTER
WITH CEILINGS AOA 050. NORTH WINDS GUSTING UP TO 30 KNOTS EARLY
THIS AFTERNOON THEN DIMINISHING QUICKLY THIS EVENING.
/OUTLOOK FOR KMSP/
FRI...VFR. WINDS NW AT 5-10 KNOTS.
SAT...VFR. WINDS SW 5-10 KNOTS.
SUN...VFR. WINDS SW 10 KNOTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
437 PM CDT WED SEP 10 2014
.UPDATE...
ISSUED AT 437 PM CDT WED SEP 10 2014
QUICK UPDATE TO EXPAND AN ISOLATED MENTION OF RAIN SHOWERS THROUGH
SOUTH CENTRAL NORTH DAKOTA THIS EVENING. LATEST BISMARCK AND
BOWMAN RADARS SHOWING AN AREA OF LIGHT RAIN SHOWERS MOVING EAST
OUT OF THE SOUTHWEST. A MID LEVEL CIRCULATION LOCATED IN THE WEST
WILL SLIDE EAST EARLY THIS EVENING...AND CONCUR WITH HIGHER
RESOLUTION MODELS OF THE RAP AND HRRR...THIS PRECIPITATION WEAKENS
BUT ALSO EXPANDS INTO SOUTH CENTRAL NORTH DAKOTA INCLUDING THE SOUTHERN
JAMES RIVER VALLEY BETWEEN 00Z AND 03Z.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 255 PM CDT WED SEP 10 2014
THE MAJOR FORECAST CHALLENGE WILL BE THE FROST POTENTIAL TONIGHT.
THE LATEST SHORT RANGE MODEL GUIDANCE CONTINUES TO PROG BOUNDARY
LAYER MOISTURE TO ERODE TO THE SOUTHWEST AS DRIER AIR GETS USHERED
IN FROM THE NORTHEAST. FURTHERMORE...BOUNDARY LAYER WINDS ARE
FORECAST TO WEAKEN TO AROUND 10 KNOTS TONIGHT AS HIGH PRESSURE
SETTLES INTO MONTANA. HOWEVER...THE LATEST GUIDANCE CONTINUES TO
PROG MID-LEVEL MOISTURE/CLOUDS (USING 850MB-500MB LAYER RH FIELDS)
TO STREAM OVER MOST OF WESTERN AND CENTRAL NORTH DAKOTA TONIGHT
AHEAD OF A SHORTWAVE ROTATING INTO MONTANA. THIS WOULD LIKELY
INHIBIT COOLING TEMPERATURES.
BALANCING WHERE THE CLEARING SKIES ARE FORECAST...WINDS WEAKENING
OVERNIGHT...AND BOUNDARY LAYER TEMPERATURES...THINK THE TURTLE
MOUNTAIN AREA WILL HAVE THE BEST CHANCE OF SEEING A FROST BETWEEN
09Z-14Z THURSDAY MORNING. AS A RESULT...ISSUED A FROST ADVISORY FOR
BOTTINEAU...ROLETTE...AND PIERCE COUNTIES FOR SAID TIME PERIOD.
TO THE SOUTHWEST...THERE WILL BE A CHANCE FOR A RAIN/SNOW MIX AFTER
MIDNIGHT. HOWEVER...ACCUMULATIONS SHOULD BE LIGHT.
FOR THURSDAY...DEEP MOISTURE AND ASSOCIATED PRECIP CHANCES WILL
CONTINUE TO PUSH SOUTH OF THE STATE AS HIGH PRESSURE BUILDS INTO THE
REGION. WELL BELOW NORMAL HIGHS ARE EXPECTED ONCE AGAIN WITH
READINGS RANGING FROM THE MID 40S SOUTHWEST TO THE MID 50S EAST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 255 PM CDT WED SEP 10 2014
FOCUS IN THE LONG TERM WILL BE ON THE POTENTIAL FOR WIDESPREAD FROST
AND A FREEZE FRIDAY MORNING.
MODEL GUIDANCE CONTINUES TO SHOW LOWS IN THE UPPER 20S ACROSS THE
WEST AND LOWER 30S ELSEWHERE. WITH A LARGE SURFACE HIGH OVER THE
NORTHERN PLAINS WINDS WILL BE LIGHT. THE BIGGEST QUESTION WILL BE
HOW FAST CLOUDS CLEAR OUT. DEEP MOISTURE ACROSS THE STATE WILL BEGIN
TO CLEAR OUT QUICKLY AROUND 18 UTC THURSDAY...HOWEVER THE 12 UTC
MODEL GUIDANCE SHOWS A THIN LAYER OF LOW TO MID LEVEL MOISTURE
HANGING AROUND THROUGH 06 UTC FRIDAY.
REGARDLESS AT LEAST PATCHY FROST SEEMS LIKELY ACROSS CENTRAL AND
WESTERN NORTH DAKOTA. WIDESPREAD FROST IS LOOKING THE MOST LIKELY
ACROSS THE NORTHWEST AS CLOUD COVER WILL CLEAR FROM NORTH TO
SOUTH. THE NORTH WILL ALSO HAVE THE BEST OPPORTUNITY FOR A FREEZE AS
LOWS WILL MOSTLY BE BELOW FREEZING...ESPECIALLY NORTHWEST. AS FOR
THE SOUTH HAVE LIMITED THE WORDING FOR FROST AT AREAS FOR NOW AS
CLOUD COVER MAY STICK AROUND LONG ENOUGH TO PREVENT WIDESPREAD FROST
DEVELOPMENT. FOR THE SAME REASON THERE IS LESS OF A CHANCE OF A
FREEZE ACROSS THE SOUTH. TEMPERATURES WILL ALSO DROP LOW ENOUGH ON
SATURDAY MORNING ACROSS THE SOUTH...ESPECIALLY FOR THE
SOUTHWEST...FOR SOME PATCHY FROST.
FOR THE REMAINDER OF THE LONG TERM THE 12 UTC MODEL GUIDANCE
CONTINUES TO SHOW A MEAN TROUGH OVER THE U.S. THE 12 UTC GFS AND
ECMWF SHOW ANOTHER SHORT WAVE RIDING DOWN THE LEE OF THE CANADIAN
ROCKIES INTO THE NORTHERN PLAINS LATE SATURDAY INTO SUNDAY. MODELS
ARE NOT SHOWING MUCH PRECIPITATION WITH THIS SYSTEM AND THE
REMAINDER OF THE LONG TERM IS ALSO LOOKING MOSTLY DRY AND WARMER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1157 AM CDT WED SEP 10 2014
VFR CIGS WILL PREVAIL OVER KISN-KMOT-KBIS-KJMS THROUGH THE TAF
PERIOD. OTHERWISE...MVFR CONDITIONS ARE EXPECTED OVER KDIK THROUGH
THE LATE EVENING HOURS. MVFR CIGS SHOULD IMPROVE TO VFR OVER
SOUTHWESTERN NORTH DAKOTA TONIGHT. SEE INDIVIDUAL KDIK TAF FOR
DETAILS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 4 AM TO 9 AM CDT THURSDAY FOR NDZ004-005-013.
&&
$$
UPDATE...KS
SHORT TERM...TM
LONG TERM...MM
AVIATION...TM
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
128 PM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE OVER IOWA WILL MOVE ACROSS LAKE HURON PULLING A STRONG
COLD FRONT ACROSS THE AREA WEDNESDAY NIGHT. A WAVE OF LOW PRESSURE
WILL MOVE UP THE OHIO VALLEY FRIDAY NIGHT INTO SATURDAY THEN HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE EAST THROUGH THE REGION
SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...MADE MORE ADJUSTMENTS TO POPS AND WX BASED ON CURRENT
RADAR TRENDS AND HRRR PROGS.
ORIGINAL...THE QUESTION TODAY IS HOW FAR OUT
AHEAD OF THE APPROACHING COLD FRONT WILL THE TSRA OCCUR. THE
LATEST MODEL RUNS HAVE QPF RAPIDLY SPREADING ESE ACROSS THE CWA
BETWEEN 18Z AND 00Z. WILL INCREASE POPS MORE FOR TODAY. THE THREAT
FOR SEVERE STORMS STILL LOOKS GOOD BASED ON INSTABILITY AND FAIRLY
GOOD WIND SHEAR. PW`S RISE BACK TO AROUND 2 INCHES SO LOCALLY
HEAVY RAIN CAN BE EXPECTED.
PATCHY MORNING FOG IN THE SOUTH WILL DISSIPATE THROUGH 10 AM.
TODAY WILL BE THE LAST RELATIVELY WARM DAY FOR A WHILE...POSSIBLY
THE REST OF THE SEASON BASED ON UPPER TROUGHING THAT IS GOING TO SET
UP OVER THE LAKES FOR AT LEAST THE NEXT 10 DAYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A FINAL BAND OF TSRA WITH THE STRONG COLD FRONT SHOULD PROGRESS
ACROSS THE CWA BETWEEN 06Z AND 12Z SO AFTER 12Z THU ONLY THE SE HALF
OF THE CWA SHOULD STILL HAVE A THREAT FOR RAIN WITH THE STRONGER
CONVECTION THEN EXITING THE CWA.
DRIER AIR MOVES IN BEHIND THE FRONT ALONG WITH THE LEADING PART OF A
MUCH COOLER AIRMASS. MARGINAL LAKE EFFECT CONDITIONS START TO
DEVELOP BY THE END OF THU NIGHT SO A FEW SHRA COULD BREAK OUT OVER
THE SNOWBELT AND NEARBY AREAS.
A SHARP S/W IS PROGGED TO MOVE EAST ACROSS THE LAKES FRI NIGHT INTO
SAT AND INDUCE A SURFACE WAVE THAT MOVES UP THE OH VALLEY. MOISTURE
POOLS BACK OVER THE AREA WITH WIDESPREAD SHRA DEVELOPING FRI NIGHT
AND CONTINUING INTO SAT BEFORE SHIFTING INTO MAINLY THE EAST SAT
AFTERNOON.
HIGH PRESSURE IS SHOWN TO BE QUICKLY SPREADING OVER THE AREA BY SAT
NIGHT BUT LAKE EFFECT CONDITIONS ARE POSSIBLE BASED ON TEMP
DIFFERENCES. DUE TO WIND ISSUES AND SUBSIDENCE FROM THE HIGH WILL
KEEP ONLY A SLIGHT CHANCE GOING SAT NIGHT IN THE NE.
TEMPS WILL TREND COOLER FOR FRI AND SAT WITH HIGHS BOTH DAYS MOSTLY
60 TO 65 DEGREES. SOME SPOTS ON SAT MAY NOT EVEN GET TO 60 DEGREES
IN THE INLAND EAST IF CLOUD COVER AND SHRA PERSIST. THE INCREASING
CLOUDS FRI NIGHT SHOULD HOLD UP LOWS IN A 45 TO 50 RANGE BUT BY SAT
NIGHT THE DECREASED CLOUDS AND LIGHT WINDS WILL ALLOW FOR LOWS IN
THE LOW TO MID 40S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
COOL HIGH PRESSURE WILL BE IN CONTROL OF THE REGION ON SUNDAY BUT IT
WILL BE SHIFTING OFF TO THE EAST AS ANOTHER UPPER LEVEL TROUGH DIGS
INTO THE GREAT LAKES REGION. AS THIS TROUGH MOVES OVERHEAD IT WILL
BRING AN INCREASING CHANCE OF SHOWERS. THE BETTER CHANCES OF THE
SHOWERS WILL BE MONDAY NIGHT INTO TUESDAY. THE SHOWERS MAY LINGER
DOWNWIND OF LAKE ERIE INTO TUESDAY EVENING. THE NEXT AREA OF HIGH
PRESSURE WILL THEN DRY THINGS OUT TUESDAY NIGHT INTO WEDNESDAY.
IT WILL BE COOL THROUGH THE LONG TERM WITH TEMPERATURES BELOW
SEASONAL AVERAGES. HIGHS AT MOST LOCATIONS WILL REMAIN IN THE 60S.
HOWEVER BY TUESDAY AND WEDNESDAY THE WESTERN COUNTY WARNING AREA
WILL BE NEAR TO SLIGHTLY ABOVE 70.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHOWERS WITH A FEW EMBEDDED TSRA MOVING THROUGH THIS EVENING
ASSOCIATED WITH WARM FRONT LIFTING ACROSS FORECAST AREA. QUESTION
REMAINS HOW STRONG THE TSRA WILL BE. SPC HAS MOST OF THE AERA IN
SLIGHT RISK FOR SEVERE FOR THIS EVENING. WITH A 50 KT JET AT 2K
FT MOVING INTO NW OH EXPECT TSRA TO INCREASE IN COVERAGE...HOWEVER
THAT SAID NOT SURE HOW WIDESPREAD TSRA WILL BECOME AS RAINSHOWERS
HAVE BEEN STABILIZING ATMOSPHERE. WILL LEAVE IN A FEW HOURS OF
TEMPO TSRA FOR NOW IN THE TAFS.
EXPECT IFR CIGS TO DEVELOP OVERNIGHT AS A COLD FRONT MOVES ACROSS
THE FORECAST AREA TONIGHT.
OUTLOOK...NON VFR POSSIBLE THURSDAY IN SHOWERS AND THUNDERSTORMS.
LOWER CEILINGS MAY LINGER OVER NE OHIO AND NW PA INTO FRIDAY AND
SATURDAY.
&&
.MARINE...
LOW PRESSURE WILL MOVE INTO THE CENTRAL GREAT LAKES TODAY WITH
INCREASING SOUTH TO SOUTHWEST WINDS EXPECTED INTO THIS EVENING.
WINDS WILL INCREASE THE EARLIEST ACROSS THE WESTERN BASIN WITH
SOUTHERLY WINDS IN THE 15 TO 25 KNOT RANGE. WINDS WILL BE OFFSHORE
SO WAVES SHOULD NOT BUILD ALL THAT MUCH. SINCE WINDS ARE EXPECTED TO
BE IN THE 15 TO 25 KNOT RANGE WE HOISTED THE SMALL CRAFT ADVISORY
FOR THIS AFTERNOON.
WINDS WILL EVENTUALLY SHIFT AROUND TO THE WEST AND NORTHWEST IN THE
WAKE OF THE COLD FRONT TONIGHT. THE FRONT SHOULD BE EAST OF THE LAKE
BY 12Z THURSDAY. THE REMAINDER OF THE LAKE WILL NEED TO HAVE A SMALL
CRAFT ADVISORY AT SOME POINT THIS EVENING INTO THE OVERNIGHT. LATER
SHIFTS WILL ISSUE IT WHEN IT IS NEEDED. THE COLD ADVECTION IN THE
WAKE OF THE FRONT WILL KEEP LARGER WAVES (4-6 FEET) GOING INTO AT
LEAST THURSDAY AFTERNOON/EVENING. AS HIGH PRESSURE RIDGES OVER THE
REGION WINDS WILL BECOME NORTHEAST BY FRIDAY MORNING. THIS WILL SET
UP A LONG FETCH INTO THE WESTERN HALF OF THE LAKE. IF THE PRESSURE
GRADIENT CAN REMAIN TIGHT ENOUGH WE MAY NEED SMALL CRAFT ADVISORIES
AGAIN FRIDAY INTO SATURDAY. MORE DETAILS TO COME ON THIS SCENARIO
THE NEXT COUPLE DAYS.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG THE FRONT
AND TRACK ACROSS MUCH OF THE LAKE. A FEW OF THESE THUNDERSTORMS WILL
BECOME STRONG ENOUGH TO WARRANT THE ISSUANCE OF SPECIAL MARINE
WARNINGS FOR THIS EVENING AND POSSIBLY INTO THE OVERNIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THURSDAY FOR LEZ142>145.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS/TK
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...DJB
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS NORMAN OK
559 PM CDT WED SEP 10 2014
.AVIATION...
0Z TAFS... VFR/MVFR CEILINGS EXPECTED FOR THIS TAF PERIOD.
SHOWERS/STORMS WILL BE POSSIBLE ACROSS THE SOUTHERN HALF OF THE
AREA THROUGHOUT THE PERIOD BUT MOST LIKELY SITES TO RECEIVE RAIN
WILL BE OVER THE NEXT FEW HOURS IN CENTRAL OK W/STRONGEST STORMS
REMAINING SOUTH AND EAST OF THE TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 356 PM CDT WED SEP 10 2014/
DISCUSSION...
THE INITIAL COLD FRONT IS CURRENTLY MOVING THROUGH SOUTHERN
OKLAHOMA AND WESTERN NORTH TEXAS. HRRR SUGGESTS THUNDERSTORMS MAY
STILL DEVELOP AHEAD OF THE FRONT IN FAR SOUTHERN OKLAHOMA AND
WESTERN NORTH TEXAS LATE AFTERNOON INTO THE EVENING. THERE WILL
ALSO BE POST-FRONTAL PRECIPITATION...SO KEPT POPS BEHIND THE
FRONT TONIGHT.
MOST AREAS SHOULD BE DRY DURING THE DAY TOMORROW. ONLY
A CHANCE ACROSS SOUTHERN OK AND WESTERN NORTH TX. A
SECONDARY...STRONGER COLD FRONT IS EXPECTED TO MOVE THROUGH THE
AREA ON FRIDAY. AHEAD OF THE SECONDARY FRONT...ISENTROPIC ASCENT
WILL BE PRESENT NEAR THE 305K SFC THURSDAY NIGHT INTO FRIDAY
MORNING. THE GREATEST ISENTROPIC ASCENT AND ELEVATED INSTABILITY
APPEARS TO BE ACROSS SOUTHERN OKLAHOMA...ESPECIALLY EAST OF I-35.
EXPECT SHOWERS AND THUNDERSTORMS DURING THIS PERIOD IN SOUTHERN
OKLAHOMA. THE ASCENT AND ASSOCIATED PRECIPITATION SHOULD WEAKEN BY
MID-MORNING.
THE AIR MASS BEHIND THIS FRONT IS FAIRLY COLD AND IS ORIGINATING
FROM A 1040 MB SFC HIGH IN WESTERN CANADA. THE FRONT APPEARS TO BE
A TYPICAL SHALLOW COLD FRONT WHERE A THERMAL TROUGH/PRESSURE RIDGE
DEVELOPS ACROSS THE HIGH PLAINS. LEANED TOWARD THE NAM12 BECAUSE
IT SEEMS TO HAVE A MORE REALISTIC REPRESENTATION OF SURFACE
FEATURES ON FRIDAY. BEHIND THE COLD FRONT...WIDESPREAD LOW CLOUDS
AND LIGHT PRECIPITATION/DRIZZLE WILL RESULT IN STEADY OR FALLING
TEMPERATURES DURING THE DAY FRIDAY. AREAS NORTH AND WEST WILL STAY
IN THE 50S ALL DAY. EVEN CENTRAL OKLAHOMA MAY SEE TEMPERATURES
FALL INTO THE 50S IN THE AFTERNOON. ASCENT SEEMS TO BE VERY WEAK
BEHIND THE FRONT...SO EXPECT VERY LIGHT PRECIPITATION TOTALS.
MAYBE SLIGHTLY HIGHER TOTALS IN NORTHWEST OK.
LOW-LEVEL DRY AIR WILL FLOW IN FROM THE NORTH FRIDAY NIGHT. SKIES
MAY CLEAR OUT ACROSS THE NORTHERN CWA. EXPECT SATURDAY MORNING
WILL BE THE COLDEST MORNING IN THE NEXT WEEK. 40S WILL BE LIKELY
NORTH OF I-40. IT WOULD NOT BE SURPRISING TO SEE A COUPLE UPPER
30S NEAR THE KANSAS BORDER IF SKIES CAN COMPLETELY CLEAR. SOUTH OF
I-40...STRONGER WINDS AND CLOUD COVER MAY KEEP TEMPERATURES FROM
BOTTOMING OUT. LOW TO MID 50S WILL BE POSSIBLE THERE.
SATURDAY...MOSTLY SUNNY SKIES ARE EXPECTED ACROSS THE NORTHERN TWO
THIRDS OF THE CWA. LOW-LEVEL RH FIELDS SUGGEST MORE WIDESPREAD
CLOUDS MAY STICK AROUND ACROSS FAR SOUTHERN OKLAHOMA AND WESTERN
NORTH TEXAS. HIGH TEMPERATURES WILL BE 10 TO 15 DEGREES BELOW
AVERAGE SATURDAY AFTERNOON.
AS A LEE TROUGH DEVELOPS...RETURN SOUTHERLY FLOW WILL RESULT IN A
MODERATING TREND ON SUNDAY. HIGHS WILL BE SEASONABLE IN THE LOW TO
MID 80S. A COLD FRONT WILL APPROACH NORTHERN OKLAHOMA LATE MONDAY
INTO TUESDAY. THERE IS SOME UNCERTAINTY ON HOW FAR SOUTH THE FRONT
WILL GO. NEVERTHELESS...THE FRONT AND NORTHWEST FLOW ALOFT SUGGEST
AT LEAST LOW POPS ARE NEEDED LATE MONDAY THROUGH WEDNESDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 62 76 61 65 / 20 10 30 40
HOBART OK 60 76 59 67 / 20 10 30 50
WICHITA FALLS TX 65 80 64 72 / 40 30 50 50
GAGE OK 53 73 51 58 / 0 10 30 50
PONCA CITY OK 57 75 55 63 / 0 10 20 40
DURANT OK 68 80 68 72 / 60 40 60 50
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
30/25/25
AREA FORECAST DISCUSSION
NWS NORMAN OK
356 PM CDT WED SEP 10 2014
.DISCUSSION...
THE INITIAL COLD FRONT IS CURRENTLY MOVING THROUGH SOUTHERN
OKLAHOMA AND WESTERN NORTH TEXAS. HRRR SUGGESTS THUNDERSTORMS MAY
STILL DEVELOP AHEAD OF THE FRONT IN FAR SOUTHERN OKLAHOMA AND
WESTERN NORTH TEXAS LATE AFTERNOON INTO THE EVENING. THERE WILL
ALSO BE POST-FRONTAL PRECIPITATION...SO KEPT POPS BEHIND THE
FRONT TONIGHT.
MOST AREAS SHOULD BE DRY DURING THE DAY TOMORROW. ONLY
A CHANCE ACROSS SOUTHERN OK AND WESTERN NORTH TX. A
SECONDARY...STRONGER COLD FRONT IS EXPECTED TO MOVE THROUGH THE
AREA ON FRIDAY. AHEAD OF THE SECONDARY FRONT...ISENTROPIC ASCENT
WILL BE PRESENT NEAR THE 305K SFC THURSDAY NIGHT INTO FRIDAY
MORNING. THE GREATEST ISENTROPIC ASCENT AND ELEVATED INSTABILITY
APPEARS TO BE ACROSS SOUTHERN OKLAHOMA...ESPECIALLY EAST OF I-35.
EXPECT SHOWERS AND THUNDERSTORMS DURING THIS PERIOD IN SOUTHERN
OKLAHOMA. THE ASCENT AND ASSOCIATED PRECIPITATION SHOULD WEAKEN BY
MID-MORNING.
THE AIR MASS BEHIND THIS FRONT IS FAIRLY COLD AND IS ORIGINATING
FROM A 1040 MB SFC HIGH IN WESTERN CANADA. THE FRONT APPEARS TO BE
A TYPICAL SHALLOW COLD FRONT WHERE A THERMAL TROUGH/PRESSURE RIDGE
DEVELOPS ACROSS THE HIGH PLAINS. LEANED TOWARD THE NAM12 BECAUSE
IT SEEMS TO HAVE A MORE REALISTIC REPRESENTATION OF SURFACE
FEATURES ON FRIDAY. BEHIND THE COLD FRONT...WIDESPREAD LOW CLOUDS
AND LIGHT PRECIPITATION/DRIZZLE WILL RESULT IN STEADY OR FALLING
TEMPERATURES DURING THE DAY FRIDAY. AREAS NORTH AND WEST WILL STAY
IN THE 50S ALL DAY. EVEN CENTRAL OKLAHOMA MAY SEE TEMPERATURES
FALL INTO THE 50S IN THE AFTERNOON. ASCENT SEEMS TO BE VERY WEAK
BEHIND THE FRONT...SO EXPECT VERY LIGHT PRECIPITATION TOTALS.
MAYBE SLIGHTLY HIGHER TOTALS IN NORTHWEST OK.
LOW-LEVEL DRY AIR WILL FLOW IN FROM THE NORTH FRIDAY NIGHT. SKIES
MAY CLEAR OUT ACROSS THE NORTHERN CWA. EXPECT SATURDAY MORNING
WILL BE THE COLDEST MORNING IN THE NEXT WEEK. 40S WILL BE LIKELY
NORTH OF I-40. IT WOULD NOT BE SURPRISING TO SEE A COUPLE UPPER
30S NEAR THE KANSAS BORDER IF SKIES CAN COMPLETELY CLEAR. SOUTH OF
I-40...STRONGER WINDS AND CLOUD COVER MAY KEEP TEMPERATURES FROM
BOTTOMING OUT. LOW TO MID 50S WILL BE POSSIBLE THERE.
SATURDAY...MOSTLY SUNNY SKIES ARE EXPECTED ACROSS THE NORTHERN TWO
THIRDS OF THE CWA. LOW-LEVEL RH FIELDS SUGGEST MORE WIDESPREAD
CLOUDS MAY STICK AROUND ACROSS FAR SOUTHERN OKLAHOMA AND WESTERN
NORTH TEXAS. HIGH TEMPERATURES WILL BE 10 TO 15 DEGREES BELOW
AVERAGE SATURDAY AFTERNOON.
AS A LEE TROUGH DEVELOPS...RETURN SOUTHERLY FLOW WILL RESULT IN A
MODERATING TREND ON SUNDAY. HIGHS WILL BE SEASONABLE IN THE LOW TO
MID 80S. A COLD FRONT WILL APPROACH NORTHERN OKLAHOMA LATE MONDAY
INTO TUESDAY. THERE IS SOME UNCERTAINTY ON HOW FAR SOUTH THE FRONT
WILL GO. NEVERTHELESS...THE FRONT AND NORTHWEST FLOW ALOFT SUGGEST
AT LEAST LOW POPS ARE NEEDED LATE MONDAY THROUGH WEDNESDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 62 76 61 65 / 20 10 30 40
HOBART OK 60 76 59 67 / 20 10 30 50
WICHITA FALLS TX 65 80 64 72 / 40 30 50 50
GAGE OK 53 73 51 58 / 0 10 30 50
PONCA CITY OK 57 75 55 63 / 0 10 20 40
DURANT OK 68 80 68 72 / 60 40 60 50
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/10
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
443 PM EDT WED SEP 10 2014
.SYNOPSIS...
HIGH PRESSURE WEDGED ALONG AND EAST OF THE CENTRAL APPALACHIANS
WILL SHIFT EAST TONIGHT. A STRONG COLD FRONT TRAILING A DEEP
CYCLONE LIFTING THROUGH THE GREAT LAKES WILL MOVE ACROSS THE
REGION ON THURSDAY. COOLER AND DRY WEATHER WILL FOLLOW BEHIND THE
COLD FRONT ON FRIDAY. A SECONDARY FRONTAL SYSTEM WILL MOVE THROUGH
THE AREA ON SATURDAY BEFORE HIGH PRESSURE RETURNS FAIR WEATHER ON
SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FROM
SATURDAY INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
EARLY EVENING VISIBLE STLT LOOP SHOWS BREAKING STRATUS ACROSS MUCH
OF CENTRAL PA...WHILE CIRRUS IS ALEADY OVERSPREADING THE NW MTNS
IN ADVANCE OF LL JET/WAA OVR THE GRT LKS.
AN INTENSE SFC CYCLONE WILL TRACK NEWD ACRS THE GREAT LAKES THIS
EVE AND CROSS THE ONT/QUE BORDER BTWN 06-12Z THU. THE TRAILING
COLD FRONT SHOULD REACH A BUF-CMH LINE BY DAYBREAK THU WITH A STG
40-50KT SSWLY LLJ PROGGED AHEAD OF THE FRONT. THE LLJ WILL DRAW
VERY HIGH MSTR CONTENT AIR INTO CENTRAL PA AHEAD OF THE FRONT
WITH PWS AROUND 2 INCHES OR + 2 TO +3 SD ABOVE THE MEAN. THIS
WILL RESULT IN VERY HIGH MSTR FLUX ANOMALIES AND SUPPORT CATG POPS
OVER NWRN SXNS. IT WILL BE A WARM AND HUMID OVERNIGHT WITH TEMPS
HOLDING IN THE MID TO UPPER 60S. IT WILL BE BREEZY OVER THE WRN
HIGH TERRAIN AND ALLEGHENY RIDGES WITH GUSTS UP TO 30 MPH.
FOLLOWED THE LATEST HRRR FOR PCPN TIMING INTO TONIGHT. THE STG WAA
AND LLJ SUPPORTS A QUICKER EWD PROGRESSION OF LEADING EDGE LGT PCPN
THRU THE UPPER OH VLY AND INTO WRN PA BTWN 00-06Z. CVRG OF SHOWER
ACTIVITY AND SHALLOW/LOW-TOPPED CONVECTION SHOULD BE GREATEST
OVER THE WRN 1/3 OF THE AREA OVERNIGHT AND INTO EARLY THU MORNING
AHEAD OF THE COLD FRONT WITH LIMITED TS/LTG. HIGHEST QPF AMTS
/0.25-0.50 INCH/ ARE ALSO FOCUSED OVER THIS AREA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
COLD FRONT TRAILING DEEP SFC LOW MOVG THRU QUE WILL BE FOCUS FOR
SHOWERS/TSTMS ON THU. THE MAIN CHANGE TO THE D2 FCST WAS FROM SPC
WHICH LOWERED THE RISK FOR SEVERE STORMS BY CUTTING OUT THE SLGT
RISK IN SCTNRL/SERN PA AND SHIFTING THE SEE TEXT/5% SVR PROBS SWD
INTO LWX CWA. THIS MAKES SENSE GIVEN EARLY MORNING CLOUDS/RAIN
RESULTING IN WEAK DIABATIC HEATING/INSTABILITY AND BEST
FORCING/SHEAR BEING DISPLACED WELL TO THE NORTH. UPDATED HWO WILL
BE ISSUED TO REFLECT THE LOWER SEVERE WX RISK...HOWEVER LCL GUSTY
WINDS WILL REMAIN PSBL IN ANY STRONGER ORGANIZED TSTM CELLS/CLUSTERS.
THE FRONT WILL EXIT THE SERN PRTNS OF THE CWA THU NGT WITH RAINS
ENDING FROM NW TO SE. VERY HIGH PWS WOULD SUPPORT SOME EFFICIENT
HEAVY DOWNPOURS BUT STORMS SHOULD BE MOVG SO HYDRO/FF CONCERNS ARE
LOW ATTM. COOLER TEMPS THU NGT AS NLY WINDS BRING DRIER AIR INTO
THE AREA BEHIND THE FIRST "FALL" FROPA.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE.
MODELS STILL SHOW NORTHERN BRANCH OF JET MOVING THINGS ALONG.
THUS DID EDGE TEMPS AND DEWPOINTS DOWN A LITTLE FOR FRIDAY.
FRIDAY STILL LOOKS DRY.
FOR SAT...STILL A CHC OF SHOWERS...GIVEN RATHER STRONG VORT
MAX IN NORTHERN BRANCH. MID SHIFT HAD BROUGHT POPS UP SOME.
I DID A LITTLE MORE. MOISTURE LIMITED...BUT DYNAMICS MAY
TRIGGER AN ISOLATED THUNDERSTORM.
LEFT SUNDAY INTO WED DRY.
SOME HINTS OF A WEAK TROUGH OVER THE LAKES EARLY NEXT WEEK...BUT
LEFT FCST DRY FOR NOW.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
LOW CIGS HAVE BEEN RATHER PERSISTENT OVER THE CENTRAL 2/3RDS OF
THE AIRSPACE AND GUID WAS TOO OPTIMISTIC ON AFTN IMPROVEMENT.
LATEST OBS TRENDS SHOW CIGS SLOWLY LIFTING AOA LOW MVFR
THRESHOLDS...WHILE CLOUDS CONTINUE TO ERODE ON THE WRN FLANKS OF
THE LOW CLOUD DECK - WEST OF THE ALLEGHENY FRONT. UPSTREAM
CUMULUS HAVE DEVELOPED IN THE PRE FRONTAL WARM SECTOR WERE THE SUN
IS OUT...QUICKLY BECOMING OVERTOPPED BY THICKENING MID TO HIGH
CLOUDS RACING EWD IN ASSOC WITH OH VLY CONVECTION. MAIN CHANGES
FOR THE 18Z SCHEDULED TAFS WAS TO INCREASE TOA FOR SHRA INTO THE
WRN AIRSPACE/ZOB SECTOR BASED ON COSPA/HRRR DATA. A VERY STRONG
SOUTHERLY FLOW/LLJ AHEAD OF THE MAIN COLD FRONT WILL RESULT IN
LLWS OVER WRN TERMINALS AFT 00Z...WHICH MAY NEED TO BE EXPANDED
INTO THE CENTRAL SITES. TOUGH CALL FOR CIG TRENDS OVER CNTRL/ERN
SXNS OVERNIGHT AS GUID WANTS TO LOWER CIGS DOWN TO IFR. FOR NOW
WILL PLAY THINGS MORE OPTIMISTICALLY WITH INCR SLY GRADIENT FLOW
SUGGESTIVE OF MORE MVFR TO LOW END VFR CIGS. FINALLY..THE LATEST
DATA SHOWS MORE CLOUDS/PCPN SPREADING INTO THE AIRSPACE THRU EARLY
TOMORROW. THIS SHOULD LIMIT HEATING AND ULTIMATELY THE RISK FOR
STG TO SVR STORM DEVELOPMENT. LATER TAFS WILL NEED TO REFINE
TIMING AND EXTENT OF PCPN CVRG.
OUTLOOK...
THU...SCT TO NMRS SHRA/TSTMS. COLD FROPA/WIND SHFT FM 180-270. AM
LOW CIGS PSBL BCMG VFR.
FRI...LOW CIGS PSBL EARLY OVR WRN 1/3...BCMG VFR.
SAT...VFR/MVFR CIGS WITH SCT SHOWERS/TSTMS.
SUN...PATCHY AM FOG...OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...MARTIN
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
356 PM EDT WED SEP 10 2014
.SYNOPSIS...
HIGH PRESSURE WEDGED ALONG AND EAST OF THE CENTRAL APPALACHIANS
WILL SHIFT EAST TONIGHT. A STRONG COLD FRONT TRAILING A DEEP
CYCLONE LIFTING THROUGH THE GREAT LAKES WILL MOVE ACROSS THE
REGION ON THURSDAY. COOLER AND DRY WEATHER WILL FOLLOW BEHIND THE
COLD FRONT ON FRIDAY. A SECONDARY FRONTAL SYSTEM WILL MOVE THROUGH
THE AREA ON SATURDAY BEFORE HIGH PRESSURE RETURNS FAIR WEATHER ON
SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FROM
SATURDAY INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
15-18Z VISIBLE STLT LOOP SHOWS PEAKS OF SUN ALONG THE ALLEGHENY
FRONT INTO THE SCNTRL MTNS..WHILE MUCH OF THE INTERIOR CWA REMAINS
M/CLOUDY FROM UNV TO SEG NWD TO THE NY BORDER. THE LATEST TRENDS
SUGGEST BINOVC DEVELOPING LOCALLY THRU 20Z.
AN INTENSE SFC CYCLONE WILL TRACK NEWD ACRS THE GREAT LAKES THIS
EVE AND CROSS THE ONT/QUE BORDER BTWN 06-12Z THU. THE TRAILING
COLD FRONT SHOULD REACH A BUF-CMH LINE BY DAYBREAK THU WITH A STG
40-50KT SSWLY LLJ PROGGED AHEAD OF THE FRONT. THE LLJ WILL DRAW
VERY HIGH MSTR CONTENT AIR INTO CENTRAL PA AHEAD OF THE FRONT
WITH PWS AROUND 2 INCHES OR + 2 TO +3 SD ABOVE THE MEAN. THIS
WILL RESULT IN VERY HIGH MSTR FLUX ANOMALIES AND SUPPORT CATG POPS
OVER NWRN SXNS. IT WILL BE A WARM AND HUMID OVERNIGHT WITH TEMPS
HOLDING IN THE MID TO UPPER 60S. IT WILL BE BREEZY OVER THE WRN
HIGH TERRAIN AND ALLEGHENY RIDGES WITH GUSTS UP TO 30 MPH.
FOLLOWED THE LATEST HRRR FOR PCPN TIMING INTO TONIGHT. THE STG WAA
AND LLJ SUPPORTS A QUICKER EWD PROGRESSION OF LEADING EDGE LGT PCPN
THRU THE UPPER OH VLY AND INTO WRN PA BTWN 00-06Z. CVRG OF SHOWER
ACTIVITY AND SHALLOW/LOW-TOPPED CONVECTION SHOULD GREATEST OVER
THE WRN 1/3 OF THE AREA OVERNIGHT AND INTO EARLY THU MORNING AHEAD
OF THE COLD FRONT WITH LIMITED TS/LTG. HIGHEST QPF AMTS /0.25-0.50
INCH/ ARE ALSO FOCUSED OVER THIS AREA.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
COLD FRONT TRAILING DEEP SFC LOW MOVG THRU QUE WILL BE FOCUS FOR
SHOWERS/TSTMS ON THU. THE MAIN CHANGE TO THE D2 FCST WAS FROM SPC
WHICH LOWERED THE RISK FOR SEVERE STORMS BY CUTTING OUT THE SLGT
RISK IN SCTNRL/SERN PA AND SHIFTING THE SEE TEXT/5% SVR PROBS SWD
INTO LWX CWA. THIS MAKES SENSE GIVEN EARLY MORNING CLOUDS/RAIN
RESULTING IN WEAK DIABATIC HEATING/INSTABILITY AND BEST
FORCING/SHEAR BEING DISPLACED WELL TO THE NORTH. UPDATED HWO WILL
BE ISSUED TO REFLECT THE LOWER SEVERE WX RISK...HOWEVER LCL GUSTY
WINDS WILL REMAIN PSBL IN ANY STRONGER ORGANIZED TSTM CELLS/CLUSTERS.
THE FRONT WILL EXIT THE SERN PRTNS OF THE CWA THU NGT WITH RAINS
ENDING FROM NW TO SE. VERY HIGH PWS WOULD SUPPORT SOME EFFICIENT
HEAVY DOWNPOURS BUT STORMS SHOULD BE MOVG SO HYDRO/FF CONCERNS ARE
LOW ATTM. COOLER TEMPS THU NGT AS NLY WINDS BRING DRIER AIR INTO
THE AREA BEHIND THE FIRST "FALL" FROPA.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT A LOT OF CHANGE.
MODELS STILL SHOW NORTHERN BRANCH OF JET MOVING THINGS ALONG.
THUS DID EDGE TEMPS AND DEWPOINTS DOWN A LITTLE FOR FRIDAY.
FRIDAY STILL LOOKS DRY.
FOR SAT...STILL A CHC OF SHOWERS...GIVEN RATHER STRONG VORT
MAX IN NORTHERN BRANCH. MID SHIFT HAD BROUGHT POPS UP SOME.
I DID A LITTLE MORE. MOISTURE LIMITED...BUT DYNAMICS MAY
TRIGGER AN ISOLATED THUNDERSTORM.
LEFT SUNDAY INTO WED DRY.
SOME HINTS OF A WEAK TROUGH OVER THE LAKES EARLY NEXT WEEK...BUT
LEFT FCST DRY FOR NOW.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
LOW CIGS HAVE BEEN RATHER PERSISTENT OVER THE CENTRAL 2/3RDS OF
THE AIRSPACE AND GUID WAS TOO OPTIMISTIC ON AFTN IMPROVEMENT.
LATEST OBS TRENDS SHOW CIGS SLOWLY LIFTING AOA LOW MVFR
THRESHOLDS...WHILE CLOUDS CONTINUE TO ERODE ON THE WRN FLANKS OF
THE LOW CLOUD DECK - WEST OF THE ALLEGHENY FRONT. UPSTREAM
CUMULUS HAVE DEVELOPED IN THE PRE FRONTAL WARM SECTOR WERE THE SUN
IS OUT...QUICKLY BECOMING OVERTOPPED BY THICKENING MID TO HIGH
CLOUDS RACING EWD IN ASSOC WITH OH VLY CONVECTION. MAIN CHANGES
FOR THE 18Z SCHEDULED TAFS WAS TO INCREASE TOA FOR SHRA INTO THE
WRN AIRSPACE/ZOB SECTOR BASED ON COSPA/HRRR DATA. A VERY STRONG
SOUTHERLY FLOW/LLJ AHEAD OF THE MAIN COLD FRONT WILL RESULT IN
LLWS OVER WRN TERMINALS AFT 00Z...WHICH MAY NEED TO BE EXPANDED
INTO THE CENTRAL SITES. TOUGH CALL FOR CIG TRENDS OVER CNTRL/ERN
SXNS OVERNIGHT AS GUID WANTS TO LOWER CIGS DOWN TO IFR. FOR NOW
WILL PLAY THINGS MORE OPTIMISTICALLY WITH INCR SLY GRADIENT FLOW
SUGGESTIVE OF MORE MVFR TO LOW END VFR CIGS. FINALLY..THE LATEST
DATA SHOWS MORE CLOUDS/PCPN SPREADING INTO THE AIRSPACE THRU EARLY
TOMORROW. THIS SHOULD LIMIT HEATING AND ULTIMATELY THE RISK FOR
STG TO SVR STORM DEVELOPMENT. LATER TAFS WILL NEED TO REFINE
TIMING AND EXTENT OF PCPN CVRG.
OUTLOOK...
THU...SCT TO NMRS SHRA/TSTMS. COLD FROPA/WIND SHFT FM 180-270. AM
LOW CIGS PSBL BCMG VFR.
FRI...LOW CIGS PSBL EARLY OVR WRN 1/3...BCMG VFR.
SAT...VFR/MVFR CIGS WITH SCT SHOWERS/TSTMS.
SUN...PATCHY AM FOG...OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...MARTIN
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
258 PM EDT WED SEP 10 2014
.SYNOPSIS...
HIGH PRESSURE WEDGED ALONG AND EAST OF THE CENTRAL APPALACHIANS
WILL SHIFT EAST TONIGHT. A STRONG COLD FRONT TRAILING A DEEP
CYCLONE LIFTING THROUGH THE GREAT LAKES WILL MOVE ACROSS THE
REGION ON THURSDAY. COOLER AND DRY WEATHER WILL FOLLOW BEHIND THE
COLD FRONT ON FRIDAY. A SECONDARY FRONTAL SYSTEM WILL MOVE THROUGH
THE AREA ON SATURDAY BEFORE HIGH PRESSURE RETURNS FAIR WEATHER ON
SUNDAY. THE OVERALL PATTERN FAVORS BELOW NORMAL TEMPERATURES FROM
SATURDAY INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
15-18Z VISIBLE STLT LOOP SHOWS PEAKS OF SUN ALONG THE ALLEGHENY
FRONT INTO THE SCNTRL MTNS..WHILE MUCH OF THE INTERIOR CWA REMAINS
M/CLOUDY FROM UNV TO SEG NWD TO THE NY BORDER. THE LATEST TRENDS
SUGGEST BINOVC DEVELOPING LOCALLY THRU 20Z.
AN INTENSE SFC CYCLONE WILL TRACK NEWD ACRS THE GREAT LAKES THIS
EVE AND CROSS THE ONT/QUE BORDER BTWN 06-12Z THU. THE TRAILING
COLD FRONT SHOULD REACH A BUF-CMH LINE BY DAYBREAK THU WITH A STG
40-50KT SSWLY LLJ PROGGED AHEAD OF THE FRONT. THE LLJ WILL DRAW
VERY HIGH MSTR CONTENT AIR INTO CENTRAL PA AHEAD OF THE FRONT
WITH PWS AROUND 2 INCHES OR + 2 TO +3 SD ABOVE THE MEAN. THIS
WILL RESULT IN VERY HIGH MSTR FLUX ANOMALIES AND SUPPORT CATG POPS
OVER NWRN SXNS. IT WILL BE A WARM AND HUMID OVERNIGHT WITH TEMPS
HOLDING IN THE MID TO UPPER 60S. IT WILL BE BREEZY OVER THE WRN
HIGH TERRAIN AND ALLEGHENY RIDGES WITH GUSTS UP TO 30 MPH.
FOLLOWED THE LATEST HRRR FOR PCPN TIMING INTO TONIGHT. THE STG WAA
AND LLJ SUPPORTS A QUICKER EWD PROGRESSION OF LEADING EDGE LGT PCPN
THRU THE UPPER OH VLY AND INTO WRN PA BTWN 00-06Z. CVRG OF SHOWER
ACTIVITY AND SHALLOW/LOW-TOPPED CONVECTION SHOULD GREATEST OVER
THE WRN 1/3 OF THE AREA OVERNIGHT AND INTO EARLY THU MORNING AHEAD
OF THE COLD FRONT WITH LIMITED TS/LTG. HIGHEST QPF AMTS /0.25-0.50
INCH/ ARE ALSO FOCUSED OVER THIS AREA.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
COLD FRONT TRAILING DEEP SFC LOW MOVG THRU QUE WILL BE FOCUS FOR
SHOWERS/TSTMS ON THU. THE MAIN CHANGE TO THE D2 FCST WAS FROM SPC
WHICH LOWERED THE RISK FOR SEVERE STORMS BY CUTTING OUT THE SLGT
RISK IN SCTNRL/SERN PA AND SHIFTING THE SEE TEXT/5% SVR PROBS SWD
INTO LWX CWA. THIS MAKES SENSE GIVEN EARLY MORNING CLOUDS/RAIN
RESULTING IN WEAK DIABATIC HEATING/INSTABILITY AND BEST
FORCING/SHEAR BEING DISPLACED WELL TO THE NORTH. UPDATED HWO WILL
BE ISSUED TO REFLECT THE LOWER SEVERE WX RISK...HOWEVER LCL GUSTY
WINDS WILL REMAIN PSBL IN ANY STRONGER ORGANIZED TSTM CELLS/CLUSTERS.
THE FRONT WILL EXIT THE SERN PRTNS OF THE CWA THU NGT WITH RAINS
ENDING FROM NW TO SE. VERY HIGH PWS WOULD SUPPORT SOME EFFICIENT
HEAVY DOWNPOURS BUT STORMS SHOULD BE MOVG SO HYDRO/FF CONCERNS ARE
LOW ATTM. COOLER TEMPS THU NGT AS NLY WINDS BRING DRIER AIR INTO
THE AREA BEHIND THE FIRST "FALL" FROPA.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY STILL LOOKS DRY. DID UP MAX TEMPS SOME.
FOR SAT...STILL A CHC OF SHOWERS...GIVEN RATHER STRONG VORT
MAX IN NORTHERN BRANCH. TOOK OUT THUNDER.
WENT WITH A DRY FCST AFT 04Z SUNDAY...AS HEIGHTS COME BACK
UP TO 570 NEAR THE LOWER LAKES...TOO WARM FOR ANYTHING OFF
THE LAKES...EVEN WITH W TO NW FLOW.
SOME HINTS OF A WEAK TROUGH OVER THE LAKES EARLY NEXT WEEK...BUT
LEFT FCST DRY FOR NOW.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
LOW CIGS HAVE BEEN RATHER PERSISTENT OVER THE CENTRAL 2/3RDS OF
THE AIRSPACE AND GUID WAS TOO OPTIMISTIC ON AFTN IMPROVEMENT.
LATEST OBS TRENDS SHOW CIGS SLOWLY LIFTING AOA LOW MVFR
THRESHOLDS...WHILE CLOUDS CONTINUE TO ERODE ON THE WRN FLANKS OF
THE LOW CLOUD DECK - WEST OF THE ALLEGHENY FRONT. UPSTREAM
CUMULUS HAVE DEVELOPED IN THE PRE FRONTAL WARM SECTOR WERE THE SUN
IS OUT...QUICKLY BECOMING OVERTOPPED BY THICKENING MID TO HIGH
CLOUDS RACING EWD IN ASSOC WITH OH VLY CONVECTION. MAIN CHANGES
FOR THE 18Z SCHEDULED TAFS WAS TO INCREASE TOA FOR SHRA INTO THE
WRN AIRSPACE/ZOB SECTOR BASED ON COSPA/HRRR DATA. A VERY STRONG
SOUTHERLY FLOW/LLJ AHEAD OF THE MAIN COLD FRONT WILL RESULT IN
LLWS OVER WRN TERMINALS AFT 00Z...WHICH MAY NEED TO BE EXPANDED
INTO THE CENTRAL SITES. TOUGH CALL FOR CIG TRENDS OVER CNTRL/ERN
SXNS OVERNIGHT AS GUID WANTS TO LOWER CIGS DOWN TO IFR. FOR NOW
WILL PLAY THINGS MORE OPTIMISTICALLY WITH INCR SLY GRADIENT FLOW
SUGGESTIVE OF MORE MVFR TO LOW END VFR CIGS. FINALLY..THE LATEST
DATA SHOWS MORE CLOUDS/PCPN SPREADING INTO THE AIRSPACE THRU EARLY
TOMORROW. THIS SHOULD LIMIT HEATING AND ULTIMATELY THE RISK FOR
STG TO SVR STORM DEVELOPMENT. LATER TAFS WILL NEED TO REFINE
TIMING AND EXTENT OF PCPN CVRG.
OUTLOOK...
THU...SCT TO NMRS SHRA/TSTMS. COLD FROPA/WIND SHFT FM 180-270. AM
LOW CIGS PSBL BCMG VFR.
FRI...LOW CIGS PSBL EARLY OVR WRN 1/3...BCMG VFR.
SAT...VFR/MVFR CIGS WITH SCT SHOWERS/TSTMS.
SUN...PATCHY AM FOG...OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LAMBERT/MARTIN
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
305 PM CDT WED SEP 10 2014
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
CLOUDY AND COLD IS THE STORY ACROSS THE REGION THIS AFTERNOON. IN
FACT...SOME LOCATIONS WILL LIKELY SET RECORDS FOR THE COLDEST
HIGH TEMPERATURE EVER RECORDED ON THIS DATE. CWA IS CURRENTLY DRY
BUT WATCHING THE BEGINNINGS OF THE NEXT SYSTEM MOVING ACROSS
NORTHWEST SD. TREND FOR TONIGHT WILL BE FOR PRECIP TO MAINLY
AFFECT WESTERN AND CENTRAL SD...AND MAY EVEN GET COLD ENOUGH LATE
TONIGHT AND EARLY THURSDAY MORNING TO ALLOW FOR A RAIN/SNOW MIX
ACROSS THE FAR NORTHWEST CWA. TARGET AREA FOR ACCUMULATING SNOW
THOUGH STILL REMAINS OVER FAR WESTERN SD AND THE BLACK HILLS. WILL
HAVE TO WATCH CLOUD COVER TRENDS OVERNIGHT ACROSS THE
NORTHERN/NORTHEAST CWA AS CIGS HAVE THINNED AND HAVE EVEN REVEALED
SOME HOLES. RAP MODEL 925-850MB RH SHOWS THIS DRIER AREA
NICELY...AND BRINGS IN OVER THE NORTHERN COUNTIES LATER TONIGHT.
IF ANY BREAKS OR THINNING OCCUR...TEMPS COULD FALL PRETTY NICELY.
BUT OVERALL...THE ABUNDANCE OF MID AND HIGH CLOUDS WITH THE NEXT
APPROACHING WAVE...AND THE OVERALL WINDS STAYING UP A TOUCH SHOULD
PREVENT THE BOTTOM FROM FALLING OUT ON TEMPS.
ATTENTION THEN TURNS TO THURSDAY NIGHT AND FRIDAY MORNING AND THE
POTENTIAL FOR FROST. MODELS CONTINUE TO SHIFT PRECIP AND CLOUDS A
BIT FURTHER SOUTH AND EAST DURING THIS TIME...A BIT QUICKER THAN
PREVIOUS RUNS...AND THE PREVIOUSLY SLOWER EC IS NOW COMING AROUND
TO THE FASTER SOLUTIONS OTHER MODELS HAVE BEEN SHOWING. THIS MEANS
A BETTER POTENTIAL FOR FROST CONDITIONS AND TEMPS IN THE LOW TO
MID 30S OVER A GOOD PORTION OF THE CWA. INSERTED FROST INTO THE
GRIDS ALONG AND WEST OF THE JAMES VALLEY AND COULD VERY WELL BE
HEADING TOWARDS A FROST ADVISORY AT SOME POINT. IT WILL ALL DEPEND
ON HOW MUCH CLOUD COVER LINGERS OVER THE AREA...THE CLEARER THE
SKIES THE BETTER THE TEMPS WILL FALL.
FOR FRIDAY NIGHT AND SATURDAY...MODELS SEEM TO BE NUDGING THE HIGH
CENTER TO THE EAST A TAD QUICKER. WHAT THIS MEANS IS THAT A
SLIGHTLY STRONGER GRADIENT SETS UP FRIDAY NIGHT WITH SOUTH WINDS
PICKING UP. WHETHER OR NOT THESE WINDS ARE STRONG ENOUGH ALONG AND
EAST OF THE JAMES VALLEY TO PREVENT TEMPS FROM REACHING THE LOW TO
MID 30S IS DOUBTFUL. WEST OF THERE...PROBABLY YES. CANNOT RULE OUT
FROST FRIDAY NIGHT/SATURDAY MORNING EITHER...BUT BEST POTENTIAL
HERE WILL BE ACROSS THE EASTERN CWA.
.LONG TERM...SATURDAY THROUGH WEDNESDAY
NOT MUCH CHANGE IN THE EXTENDED FROM 24 HOURS AGO. 12Z MODEL
SOLUTIONS POINT TO A BIT OF WARMING ON SATURDAY OUT AHEAD OF AN
APPROACHING COLD FRONT. ANOTHER SURFACE HIGH PRESSURE SYSTEM
BUILDS DOWN FOR SUNDAY AND MONDAY...BUT THEN SHIFTS SOUTH AND EAST
OF THE AREA...ALLOWING FOR RETURN FLOW WARMING WINDS TUESDAY AND
WEDNESDAY. PRECIPITATION CHANCES REALLY ARE FEW AND FAR BETWEEN IN
THE OUT PERIODS...WITH THE "BEST" CHANCES FOR A FEW RAIN
SHOWERS SHOWING UP SUNDAY AFTERNOON/EVENING BEHIND THIS COLD
FROPA.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
CONDITIONS ARE IMPROVING ACROSS THE REGION. KMBG HAS BEGUN
BOUNCING IN AND OUT OF VFR/MVFR...AND KATY IS SLOWLY TRENDING
TOWARD AN MVFR CIG. KPIR/KABR REMAIN MVFR AS WELL...BUT SATELLITE
TRENDS AND SHORT RANGE RAPID REFRESH MODEL OUTPUT ALL POINT TO
VFR RETURNING TO THE REGION AS THE PREVAILING CONDITION BY 00Z
THIS EVENING AT KABR/KPIR AND KMBG...WITH KATY FOLLOWING BY 06Z.
THE RAPID REFRESH MODEL IS ALSO TAKING PRECIP CHANCES SOUTH LATER
THIS EVENING...WITH THE BULK OF ANY PRECIP CHANCES WITH THIS NEXT
LITTLE WAVE OF LOW PRESSURE RE-ALIGNING TOWARD THE KPIR AREA LATER
AT OR AFTER MIDNIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...DORN
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
115 PM CDT WED SEP 10 2014
.UPDATE...
DECIDED TO PULL THE TRIGGER ON LOWERING THE MAX T GRID ACROSS THE
BOARD FOR THIS AFTERNOON. HOURLY FORECAST WAS TRENDING ABOUT 2-4
DEGREES BELOW REALITY AND WITH THE SKIES MOSTLY CLOUD COVERED AND
SHOULD REMAIN THAT WAY...DONT THINK WE WILL HIT THE PREVIOUSLY
ADVERTISED HIGHS.
ALSO RAISED POPS IN THE WEST DUE TO THE ISOLATED SHOWERS POPPING
UP WEST OF I65. WITH IT BEING ONLY 18Z AND A BIT MORE CONVECTIVE
POTENTIAL IS EXPECTED WITH A VERY MOIST ATMOSPHERE...THINK THIS IS
PROBABLY A SAFE BET.
&&
.PREV DISCUSSION... /ISSUED 1204 PM CDT WED SEP 10 2014/
AVIATION UPDATE...FOR 18Z TAF PACKAGE...
MVFR CONDITIONS CONTINUE TO PERSIST FOR KCKV AND KBNA. SHOULD SEE
A BRIEF IMPROVEMENT BUT PROBABLY NOT UNTIL AFTER DARK. AN
APPROACHING COLD FRONT WILL CONTINUE TO INCREASE CLOUD COVERAGE
ALTHOUGH A CEILINGS SHOULD RISE TO VFR HEIGHTS BRIEFLY BEFORE THE
RAIN ARRIVES. INCLUDED -SHRA MENTION BEGINNING JUST BEFORE
MIDNIGHT FOR KCKV. ACTIVITY SHOULD PROGRESS EASTWARD SLOWLY AND
IMPACT KBNA BY JUST BEFORE DAWN. LEFT RAIN OUT OF KCSV FOR NOW BUT
DID MENTION MVFR BR POSSIBILITIES IN THE EARLY MORNING THERE.
PREV DISCUSSION... /ISSUED 1141 AM CDT WED SEP 10 2014/
UPDATE...
WITH THE APPROACHING COLD FRONT BRINGING A BROKEN DECK OF HIGH
CLOUDS FOR MUCH OF THE WESTERN HALF OF THE CWA...AND BOUNDARY
LAYER CONVECTIVE CU BEGINNING TO FORM AS WELL...OPTED TO INCREASE
THE SKY GRIDS TO MOSTLY CLOUDY WORDING THROUGH THE EVENING.
VIS SATELLITE IS SHOWING AN AREA OF CONFLUENCE IN NORTHERN MS AND
WESTERN TN. THIS IS JUST AHEAD OF THE CURRENT ACTIVITY APPROACHING
THE MO BOOTHEEL WHICH MAY PROVIDE ENOUGH BOUNDARY LAYER
CONVERGENCE TO PRODUCE ISOLATED SHOWER AND STORM DEVELOPMENT OVER
THE NEXT COUPLE HOURS. HRRR SEEMS TO AGREE BUT IS A BIT EARLY ON
THE DEVELOPMENT. SOME OF THOSE SHOWERS MAY IMPACT OUR CWA WEST OF
THE I65 CORRIDOR MAINLY. WE CURRENTLY HAVE SLIGHT CHANCE POPS IN
THE GRIDS FOR THE AFTERNOON AND WITH THE EXPECTED ISOLATED NATURE
OF THE DEVELOPMENT...DONT SEE A REASON TO INCREASE TO CHC POPS
JUST YET. MAY NEED ANOTHER UPDATE IF THINGS ARE A BIT MORE SUBSTANTIAL.
ALSO KEEPING AN EYE ON THE MAX T AS CLOUDS CONTINUE TO LIMIT
WARMING...WE ARE ABOUT 2-3 DEGREES BELOW THE FORECAST HOURLY TEMPS
ACROSS THE BOARD SO IF THAT PERSISTS...MAY NEED TO LOWER THE MAX T
GRID AS WELL. WILL REEVALUATE AT 18Z.
PREV DISCUSSION... /ISSUED 625 AM CDT WED SEP 10 2014/
AVIATION...BNA/CKV/CSV...LOW CLOUDS AT CSV SHOULD GIVE WAY BY 15Z
OR SO. LOOK FOR WINDS TO INCREASE THIS MORNING AHEAD OF A SLOW-
MOVING COLD FRONT. VFR CIGS WILL COVER MIDDLE TENNESSEE MOST OF
TODAY AND TONIGHT WITH SHRA AND POSSIBLE TSRA MOVING INTO NW
MIDDLE TENNESSEE OVERNIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1204 PM CDT WED SEP 10 2014
.AVIATION UPDATE...FOR 18Z TAF PACKAGE...
MVFR CONDITIONS CONTINUE TO PERSIST FOR KCKV AND KBNA. SHOULD SEE
A BRIEF IMPROVEMENT BUT PROBABLY NOT UNTIL AFTER DARK. AN
APPROACHING COLD FRONT WILL CONTINUE TO INCREASE CLOUD COVERAGE
ALTHOUGH A CEILINGS SHOULD RISE TO VFR HEIGHTS BRIEFLY BEFORE THE
RAIN ARRIVES. INCLUDED -SHRA MENTION BEGINNING JUST BEFORE
MIDNIGHT FOR KCKV. ACTIVITY SHOULD PROGRESS EASTWARD SLOWLY AND
IMPACT KBNA BY JUST BEFORE DAWN. LEFT RAIN OUT OF KCSV FOR NOW BUT
DID MENTION MVFR BR POSSIBILITIES IN THE EARLY MORNING THERE.
&&
.PREV DISCUSSION... /ISSUED 1141 AM CDT WED SEP 10 2014/
UPDATE...
WITH THE APPROACHING COLD FRONT BRINGING A BROKEN DECK OF HIGH
CLOUDS FOR MUCH OF THE WESTERN HALF OF THE CWA...AND BOUNDARY
LAYER CONVECTIVE CU BEGINNING TO FORM AS WELL...OPTED TO INCREASE
THE SKY GRIDS TO MOSTLY CLOUDY WORDING THROUGH THE EVENING.
VIS SATELLITE IS SHOWING AN AREA OF CONFLUENCE IN NORTHERN MS AND
WESTERN TN. THIS IS JUST AHEAD OF THE CURRENT ACTIVITY APPROACHING
THE MO BOOTHEEL WHICH MAY PROVIDE ENOUGH BOUNDARY LAYER
CONVERGENCE TO PRODUCE ISOLATED SHOWER AND STORM DEVELOPMENT OVER
THE NEXT COUPLE HOURS. HRRR SEEMS TO AGREE BUT IS A BIT EARLY ON
THE DEVELOPMENT. SOME OF THOSE SHOWERS MAY IMPACT OUR CWA WEST OF
THE I65 CORRIDOR MAINLY. WE CURRENTLY HAVE SLIGHT CHANCE POPS IN
THE GRIDS FOR THE AFTERNOON AND WITH THE EXPECTED ISOLATED NATURE
OF THE DEVELOPMENT...DONT SEE A REASON TO INCREASE TO CHC POPS
JUST YET. MAY NEED ANOTHER UPDATE IF THINGS ARE A BIT MORE SUBSTANTIAL.
ALSO KEEPING AN EYE ON THE MAX T AS CLOUDS CONTINUE TO LIMIT
WARMING...WE ARE ABOUT 2-3 DEGREES BELOW THE FORECAST HOURLY TEMPS
ACROSS THE BOARD SO IF THAT PERSISTS...MAY NEED TO LOWER THE MAX T
GRID AS WELL. WILL REEVALUATE AT 18Z.
PREV DISCUSSION... /ISSUED 625 AM CDT WED SEP 10 2014/
AVIATION...BNA/CKV/CSV...LOW CLOUDS AT CSV SHOULD GIVE WAY BY 15Z
OR SO. LOOK FOR WINDS TO INCREASE THIS MORNING AHEAD OF A SLOW-
MOVING COLD FRONT. VFR CIGS WILL COVER MIDDLE TENNESSEE MOST OF
TODAY AND TONIGHT WITH SHRA AND POSSIBLE TSRA MOVING INTO NW
MIDDLE TENNESSEE OVERNIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1141 AM CDT WED SEP 10 2014
.UPDATE...
WITH THE APPROACHING COLD FRONT BRINGING A BROKEN DECK OF HIGH
CLOUDS FOR MUCH OF THE WESTERN HALF OF THE CWA...AND BOUNDARY
LAYER CONVECTIVE CU BEGINNING TO FORM AS WELL...OPTED TO INCREASE
THE SKY GRIDS TO MOSTLY CLOUDY WORDING THROUGH THE EVENING.
VIS SATELLITE IS SHOWING AN AREA OF CONFLUENCE IN NORTHERN MS AND
WESTERN TN. THIS IS JUST AHEAD OF THE CURRENT ACTIVITY APPROACHING
THE MO BOOTHEEL WHICH MAY PROVIDE ENOUGH BOUNDARY LAYER
CONVERGENCE TO PRODUCE ISOLATED SHOWER AND STORM DEVELOPMENT OVER
THE NEXT COUPLE HOURS. HRRR SEEMS TO AGREE BUT IS A BIT EARLY ON
THE DEVELOPMENT. SOME OF THOSE SHOWERS MAY IMPACT OUR CWA WEST OF
THE I65 CORRIDOR MAINLY. WE CURRENTLY HAVE SLIGHT CHANCE POPS IN
THE GRIDS FOR THE AFTERNOON AND WITH THE EXPECTED ISOLATED NATURE
OF THE DEVELOPMENT...DONT SEE A REASON TO INCREASE TO CHC POPS
JUST YET. MAY NEED ANOTHER UPDATE IF THINGS ARE A BIT MORE SUBSTANTIAL.
ALSO KEEPING AN EYE ON THE MAX T AS CLOUDS CONTINUE TO LIMIT
WARMING...WE ARE ABOUT 2-3 DEGREES BELOW THE FORECAST HOURLY TEMPS
ACROSS THE BOARD SO IF THAT PERSISTS...MAY NEED TO LOWER THE MAX T
GRID AS WELL. WILL REEVALUATE AT 18Z.
&&
.PREV DISCUSSION... /ISSUED 625 AM CDT WED SEP 10 2014/
AVIATION...BNA/CKV/CSV...LOW CLOUDS AT CSV SHOULD GIVE WAY BY 15Z
OR SO. LOOK FOR WINDS TO INCREASE THIS MORNING AHEAD OF A SLOW-
MOVING COLD FRONT. VFR CIGS WILL COVER MIDDLE TENNESSEE MOST OF
TODAY AND TONIGHT WITH SHRA AND POSSIBLE TSRA MOVING INTO NW
MIDDLE TENNESSEE OVERNIGHT.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TB12
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
113 PM EDT WED SEP 10 2014
.SYNOPSIS...
LOW PRESSURE PASSING WELL TO THE NORTH WILL DRAG A TRAILING COLD
FRONT TOWARD THE REGION TONIGHT...REACHING THE WESTERN SLOPES OF
THE APPALACHIANS BY LATER THURSDAY. THE FRONT IS EXPECTED TO
STALL OVER THE CAROLINAS FRIDAY AND THEN MEANDER JUST SOUTH OF
THE AREA OVER THE WEEKEND. WEAK LOW PRESSURE RIDING ALONG THE
BOUNDARY MAY KEEP PERIODS OF SHOWERS GOING INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1113 AM EDT WEDNESDAY...
UPDATING TO LOWER TEMPS A BIT AND HOLD CLOUDS LONGER ESPCLY ALONG
THE BLUE RIDGE WHERE LOW CLOUDS REMAIN PERSISTENT WITH EVEN SOME
SPOTTY -RA MIXED IN GIVEN THE WEAK LOW LEVEL VEERING PROFILE OFF
MORNING RAOBS. ALSO WITH SO MUCH LINGERING MOISTURE STUCK BENEATH
MULTIPLE INVERSIONS ALOFT OFF 12Z SOUNDINGS APPEARS WILL BE TOUGH
TO GET A QUICK EROSION OF THE CANOPY WITHOUT IT FILLING BACK IN
ESPCLY EARLY ON. EXPECT ONCE THE FLOW TURNS MORE SOUTH/SW LATER ON
AND MIXING INCREASES WILL SEE SOME DRIER AIR ALOFT MIX DOWN BUT
MAY BE LATE BEFORE THE EASTERN SLOPES OF THE BLUE RIDGE SEE A LOT
OF SUN. TEMPS LIKELY TO JUMP WHERE DO GET SOME SUSTAINED BREAKS
BUT FOR NOW BASED ON LATEST TRENDS AND LAV MOS...THINK HIGHS MAY
REMAIN IN THE 70S EXCEPT FOR THE FAR EAST/SE AND WESTERN PERIMETER
COUNTIES. ISOLATED WESTERN POPS THIS AFTERNOON STILL APPEAR OK
WITH THE BRIEF SHOTGUN PATTERN SUGGESTED BY THE LATEST HRRR BUT
THIS BASED ON SOME INSTABILITY PER HEATING WHICH MAY ONLY OCCUR
ALONG THE I-77 CORRIDOR AT THIS POINT.
PREVIOUS UPDATE AS OF 925 AM EDT WEDNESDAY...
ADDED SLIGHT CHANCE POPS ALONG THE BLUE RIDGE UP TO ROANOKE AS
SURFACE OBS AND WEATHER SPOTTERS HAVE CONFIRMED SOME LIGHT DRIZZLE
THIS MORNING. TWEAKED THE SKY GRIDS OUT WEST WHERE THERE HAS BEEN
SOME CLEARING. ALSO ADJUSTED THE NEAR TERM TEMPS. ALL OTHER
FORECAST DETAILS FROM THE PREVIOUS DISCUSSION REMAIN ON TRACK.
PREVIOUS DISCUSSION AS OF 430 AM EDT WEDNESDAY...
STARTING OFF WITH LOTS OF CLOUD COVER THIS MORNING...COURTESY OF
LINGERING MOISTURE BANKED UP AGAINST THE EAST SIDE OF THE
MOUNTAINS. THE EASTERLY WIND WHICH HAS BEEN KEEPING THE CLOUDS
PINNED ACROSS THE AREA WILL WEAKEN TODAY AS FLOW BEGINS TO TREND
MORE SOUTHERLY PER APPROACH OF FRONTAL SYSTEM OVER THE MIDDLE PART
OF THE COUNTRY.
AS OF 4AM...CYCLOGENESIS WAS TAKING PLACE OVER THE MIDDLE PART OF
THE COUNTRY WITH LOW PRESSURE DEVELOPING NEAR TOPEKA KANSAS. THIS
AREA OF LOW PRESSURE IS FORECAST TO STRENGTHEN TODAY PER STRONG
DYNAMICS ALOFT ASSOCIATED WITH A SHORT WAVE TROUGH EXITING THE
ROCKIES. THE DEEPENING LOW...10 MB PRESSURE FALL OVER THE NXT 12
HOURS...IS PROGGED TO MOVE NORTHEAST INTO THE GREAT LAKES...THE
TRAILING COLD FRONT SLICING SOUTH THROUGH MISSOURI-TEXAS. AHEAD OF
THE FRONT...WINDS WILL BE SOUTHWESTERLY THROUGH THE TENNESSEE AND
OHIO VALLEYS...WARM AIR ADVECTION TAKING PLACE UPSTREAM OF OUR
FORECAST AREA...AND EVENTUALLY INCLUDING OUR FORECAST AREA LATER
TODAY AND TONIGHT.
AS WARM AIR ADVECTION INCREASES FROM THE SOUTHWEST LATER
TODAY...EXPECT CLOUD COVER CURRENTLY OVER OUR FORECAST AREA TO MIX
OUT WITH INCREASING AMOUNTS OF SUN. SUNNY BREAKS WILL LIKELY BEGIN
IN THE WESTERN PART OF THE CWA FIRST...THEN SPREAD EAST. MORE SUN
MEANS WARMER TEMPERATURES...MODEL MOS SUGGESTING WE TEST 80 TODAY
WITH A TEMPERATURE RANGE OF 76 TO 83. MILD TEMPERATURES ARE LIKELY
TONIGHT...SOUTHWEST WINDS CONTINUING TO PROMOTE WARM AIR
ADVECTION...LOWS IN THE 60S.
NOT MUCH THREAT FOR PRECIP TODAY OR TONIGHT. MODEL SOUNDINGS
INDICATE CAPE VALUES POTENTIALLY REACHING 500 J/KG IN THE
MOUNTAINS TODAY. THIS MAY SUPPORT AN ISOLATED SHOWER OR TWO...BUT
NOT MUCH MORE THAN THAT. BETTER CHANCE FOR PRECIP WILL COME WITH
THE FRONTAL PASSAGE LATER THURSDAY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
LOOK FOR THURSDAY TO BE THE WARMEST DAY OF THE WEEK AS DEEP
SOUTHWESTERLY FLOW BECOMES ESTABLISHED AHEAD OF A STRONG COLD FRONT
APPROACHING FROM THE GREAT LAKES REGION. THE SOUTHWESTERLY WINDS
WILL DRAW VERY WARM GULF MOISTURE NORTHWARD ALONG THE APPALACHIAN
CHAIN...WHICH WILL HELP AFTERNOON HIGHS CLIMB INTO THE UPPER 70S/LOW
80S ACROSS THE MOUNTAINS...WHILE THE PIEDMONT WILL REACH INTO THE
MID 80S TO AROUND 90 IN THE SOUTHSIDE. RAIN CHANCES WILL INCREASE
DRASTICALLY DURING THE AFTERNOON AS THE FRONT CROSSES THE OHIO
RIVER...WITH SHOWERS AND THUNDERSTORMS BECOMING WIDESPREAD ACROSS
MOST OF THE AREA BY SUNSET.
STORM PREDICTION CENTER HAS MUCH OF OUR FORECAST REGION UNDER A
SLIGHT CHANCE FOR SEVERE THUNDERSTORMS...SO WILL BE ON THE LOOKOUT
FOR A FEW STORMS PACKING GUSTY WINDS DURING THE EVENING...MAINLY
NORTH OF HIGHWAY 460...AS THE STRONGER DOWNDRAFTS TRY TO PULL THE
25KT-30KT 850MB WINDS DOWN TO THE SURFACE. BELIEVE THERE WILL ALSO
BE A CHANCE FOR LOCALLY HEAVY RAIN ACROSS THE MOUNTAINS AS GULF
MOISTURE POOLING AHEAD OF THE FRONT PUSHES PRECIPITABLE WATER IN THE
BALLPARK OF 2 INCHES.
THE COLD FRONT WILL CONTINUE ITS SOUTHWARD PUSH THURSDAY NIGHT...
BEFORE STALLING ACROSS CENTRAL NORTH CAROLINA JUST SOUTH OF OUR AREA
ON FRIDAY AS IT RUNS INTO UPPER LEVEL RIDGING ACROSS THE SOUTHEAST
STATES. MODELS ARE COMING INTO BETTER AGREEMENT THAT...DESPITE THE
FRONTAL PASSAGE...DEWPOINTS DO NOT DROP OFF ALL THAT MUCH FOR OUR
AREA. AS SUCH...EXPECT THAT THERE WILL BE ENOUGH LOW LEVEL MOISTURE
LEFT OVER TO SUPPORT SCATTERED SHOWER ACTIVITY ACROSS THE MOUNTAINS
AND THE PIEDMONT SOUTH OF HIGHWAY 460 THROUGH THE AFTERNOON AND
EVENING. DRIER HIGH PRESSURE WILL BE WEDGING SOUTHWARD ACROSS THE
PIEDMONT FURTHER NORTH. HIGHS FOR FRIDAY WILL BE COOLER...MAINLY IN
THE 70S MOST LOCATIONS.
SHOWER ACTIVITY WILL INCREASE AGAIN ON SATURDAY AS A WAVE OF LOW
PRESSURE DEVELOPS ALONG THE FRONT. SURFACE HIGH PRESSURE BANKED
AGAINST THE EASTERN FACE OF THE APPALACHIANS WILL PROVIDE ENOUGH
STABILITY TO LIMIT RAINFALL TO SHOWER ACTIVITY FOR MOST OF THE
AREA...ALTHOUGH AN ISOLATED THUNDERSTORM MAY DEVELOP ACROSS THE
MOUNTAIN EMPIRE...AN AREA REMOVED FROM THE INFLUENCE OF THE HIGH. AT
ANY RATE...THE WAVE WILL SHIFT RAPIDLY TO THE NORTH ON SATURDAY...
DRAGGING A SECONDARY COLD FRONT ACROSS OUR AREA DURING THE EVENING.
CANADIAN HIGH PRESSURE BUILDING IN BEHIND THE COLD FRONT WILL BE THE
COOLEST AIR WE HAVE SEEN IN SEVERAL MONTHS...A DEFINITE SIGNAL
THAT AUTUMN IS NOT TOO FAR INTO THE FUTURE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...
FORECAST REMAINS RATHER LOW CONFIDENCE FOR SUNDAY INTO TUESDAY GIVEN
WEST/SW FLOW ALOFT BETWEEN AN UPPER TROUGH TO THE NW AND THE
RESIDUAL AXIS OF DEEPER MOISTURE ALONG THE COAST. LATEST GUIDANCE
STILL RATHER MIXED ON DEGREE OF MOISTURE GETTING PULLED BACK
INLAND/NORTH AHEAD OF THE MAIN TROUGH AS APPEARS SOME SORT OF
LEFTOVER DEFORMATION AXIS MAY LINGER WITH THE COASTAL LOW. THUS KEPT
SOME LOW POPS IN SOUTH/EAST ESPCLY SUNDAY/SUNDAY NIGHT THEN
DECREASING MONDAY FOR NOW. APPEARS DRIER AIR WITH THE STRONGER
SURFACE HIGH BUILDING IN FROM THE NW WILL FINALLY OCCUR BY TUESDAY
BUT EVEN THEN CLOUDS/SHOWERS MAY LINGER/RETURN WITH YET ANOTHER WAVE
PASSING. TEMPS TO COOL BELOW NORMAL THROUGH THE PERIOD WITH MAINLY
60S MOUNTAINS AND LOW 70S EAST FOR HIGHS...AND 50S WEST 60S PIEDMONT
FOR LOWS PENDING CLOUD COVER WHICH COULD MAKE HIGHS EVEN COOLER.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 1255 PM EDT WEDNESDAY...
STUBBORN LOW LEVEL CLOUDS REMAIN SLOW TO ERODE EARLY THIS
AFTERNOON WITH MOSTLY MVFR CIGS IN PLACE. STILL EXPECTING A
GRADUAL IMPROVEMENT TO VFR BASES AS WELL AS A REDUCTION IN CLOUD
COVER THROUGH THE REST OF THE AFTERNOON/EVENING AS WINDS BECOME
MORE SOUTHERLY. HOWEVER MAY STILL TAKE UNTIL LATE IN THE DAY FOR
LOWER CIGS AT KBCB/KROA TO LIFT INTO VFR RANGE.
A STRONG LOW PRESSURE SYSTEM PASSING WELL TO THE NORTH WILL PROPEL
A TRAILING COLD FRONT TOWARD THE AREA LATE TONIGHT INTO THURSDAY.
PRE-FRONTAL SHOWERS/STORMS AHEAD OF THE FRONT MAY APPROACH THE FAR
NORTHWESTERN LOCATIONS EARLY THURSDAY WITH INCREASING COVERAGE
FROM NW TO SE DURING THE DAY. AS DEEPER MOISTURE RETURNS LATER
TONIGHT...LIKELY TO SEE SOME LOW CLOUDS RETURN WEST WHILE LIGHT
WINDS MAY PROMOTE RETURN OF THE RESIDUAL WEDGE AND LOW CLOUDS BLUE
RIDGE LATE TONIGHT. WONT GO QUITE AS PESSIMISTIC AS MOST GUIDANCE
GIVEN WEAK SOUTHERLY FLOW BUT INCLUDING SOME MVFR CIGS FROM THE
BLUE RIDGE EAST ALONG WITH BRIEF DENSE FOG THAT MAY BRING PERIODS
OF MVFR/IFR BY DAYBREAK THURSDAY.
ANY LOW CLOUDS/FOG SHOULD FINALLY MIX OUT WITH INCREASING SW FLOW
THURSDAY MORNING OVER THE EAST...WHILE CIGS LOWER OVER THE WEST
WITH LEFTOVER EARLIER SHRA PERHAPS REACHING KLWB/KBLF LATE
MORNING/EARLY AFTERNOON THURSDAY. HOWEVER APPEARS BEST SHOT AT
SEEING BANDS/CLUSTERS OF CONVECTION WONT OCCUR UNTIL MID/LATE
AFTERNOON THURSDAY AND BEYOND THE TIME OF THE VALID TAF PERIOD.
WEST/SW WINDS SHOULD TURN A BIT GUSTY AS WELL AHEAD OF THE FRONT
THURSDAY AFTERNOON WITH 10-20 KTS LIKELY AND STRONGER CLOSER TO
ANY STORMS.
EXTENDED DISCUSSION...
FROPA IS EXPECTED THURSDAY NIGHT. THIS FRONTAL PASSAGE WILL NOT
BE A CLEAN SWEEP OF AIRMASSES...THE MAJORITY OF THE MODELS
INDICATING THE FRONT WILL STALL OVER THE CAROLINAS
FRIDAY...FOLLOWED BY DEVELOPMENT OF LOW PRESSURE ALONG THE FRONT
FRIDAY NIGHT...TRACKING NORTHEAST THROUGH THE REGION SATURDAY.
STILL APPEARS THAT AN EXTENDED PERIOD OF MVFR...POSSIBLY
IFR...WILL EXIST FRIDAY NIGHT INTO SATURDAY. LOW CONFIDENCE
FORECAST FOR SUNDAY WITH MODELS SHOWING LOW LEVEL MOISTURE
LINGERING ALONG WITH SPOTTY SHOWERS AS COMPLEX LOW PRESSURE
DEVELOPS OVER THE REGION SO APPEARS OVERALL MVRF TO PERSIST INTO
SUNDAY NIGHT AT THIS POINT. LOW CLOUDS MAY ERODE ON MONDAY BUT
WITH LEFTOVER MOISTURE EXPECTING POTENTIAL FOR MVFR AT TIMES IN
SPOTTY SHOWERS MONDAY AFTERNOON. OTRW SLOW IMPROVEMENT TO VFR FOR
EARLY NEXT WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...CF/JH/PM
SHORT TERM...NF
LONG TERM...JH
AVIATION...JH/PM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 242 PM CDT WED SEP 10 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRONG
LOW PRESSURE SYSTEM TRACKING NORTHEAST TOWARDS MANITOWOC WHILE A
POTENT COLD FRONT IS DROPPING SOUTHEAST FROM THE BAY OF GREEN BAY TO
JUST WEST OF OSHKOSH. MOST OF THE HEAVIER RAINFALL HAS EXITED THE
REGION TO THE NORTHEAST EXCEPT FOR FAR WESTERN ONEIDA AND VILAS
COUNTIES. AREAS OF DRIZZLE OR VERY LIGHT RAIN WILL GRADUALLY
DIMINISH THROUGH THE REST OF THE AFTERNOON AS THE CYCLONE EXITS THE
REGION. OBSERVATIONS INDICATE A WIDESPREAD 1.5 TO 2.5 INCHES OF
RAIN OVER NORTH-CENTRAL WISCONSIN FOR A STORM TOTAL. AREA RIVERS
SEEM TO BE HOLDING UP WELL AND HAVE RECEIVED NO REPORTS OF FLOODING
SO FAR. WILL LET THE FLOOD WATCH EXPIRE WITH THIS FORECAST
ISSUANCE. GUSTY NORTHWEST WINDS ARE USHERING IN THE FIRST TASTE OF
FALL BEHIND THE COLD FRONT. TEMPERATURES ARE FALLING INTO THE 40S
AND 50S BEHIND THE FRONT...WHILE READINGS REMAIN IN THE 60S AND 70S
AHEAD OF THE FRONT. TIMING THE END OF THE PRECIP...TEMPS...AND
MARINE HEADLINES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...LOW PRESSURE WILL CONTINUE TO MOVE TO THE NORTHEAST INTO
EASTERN ONTARIO AND WESTERN QUEBEC WHILE THE STRONG COLD FRONT MOVES
EAST ACROSS THE LOWER PENINSULA OF MICHIGAN. BEHIND THE
FRONT...GUSTY NORTHWEST WINDS WILL USHER IN A MIGHTY CHILLY AIRMASS
FOR THIS TIME OF THE YEAR. WITH LOW INVERSION HEIGHTS OF AROUND
875MB...THE AIRMASS WILL BE PLENTY COLD ENOUGH TO SUPPORT LAKE
EFFECT RAIN SHOWERS OFF LAKE SUPERIOR...WHICH WILL LIKELY JUST
IMPACT VILAS COUNTY AS WIND TRAJECTORIES ARE TOO NORTHERLY FOR A
DIRECT HIT. PLENTY OF LOW STRATUS UPSTREAM BENEATH THIS
INVERSION...AND WITH MOISTURE FLUXES OFF LAKE SUPERIOR COMBINED WITH
THERMAL TROUGHING...HAVE A TOUGH TIME SEEING ANY SORT OF CLEARING
TAKING PLACE. PERHAPS A FEW HOLES IN THE OVERCAST IN THE
DOWNSLOPING AREAS OF NORTHEAST WISCONSIN. LOWS FALLING INTO THE
UPPER 30S NORTH TO UPPER 40S SOUTHEAST.
THURSDAY...850MB TEMPERATURES CONTINUE TO FALL AS CANADIAN HIGH
PRESSURE BUILDS TOWARDS THE REGION. THE INVERSION WILL REMAIN STOUT
ABOVE STEEP LOW LEVEL LAPSE RATES. AS A RESULT...CLOUDY CONDITIONS
IN THE MORNING WILL BE SLOW TO BREAK UP...ESPECIALLY WITH MID-LEVEL
CLOUDS ARRIVING IN THE AFTERNOON. SO EXPECT SKY CONDITIONS TO
REMAIN AT LEAST PARTLY SUNNY OR MOSTLY CLOUDY THROUGH THE
DAY. HIGHS RANGING FROM THE UPPER 40S NORTH TO MIDDLE 50S SOUTH.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 242 PM CDT WED SEP 10 2014
LARGE SURFACE HIGH SHOULD COVER THE NORTHERN AND
CENTRAL PLAINS ALL THE WAY EAST TO THE GREAT LAKES AND NORTHERN
OHIO VALLEY THURSDAY NIGHT THROUGH FRIDAY EVENING. WHILE THIS
WOULD NORMALLY RESULT IN A DRY FORECAST AND CLEAR SKIES THERE IS A
SHARP UPPER LEVEL TROUGH THAT WILL BE MOVING ACROSS WISCONSIN
FRIDAY AND FRIDAY EVENING THAT SHOULD BE STRONG ENOUGH TO PRODUCE
SOME LIGHT RAIN DESPITE SURFACE HIGH PRESSURE AND DRY AIR IN THE
LOW LEVELS. THE CLOUDS AND LIGHT RAIN SHOULD KEEP HIGH TEMPERATURES
LOWER THAN MOS GUIDANCE FRIDAY SO WENT ABOUT 3 DEGREES LOWER IN
MOST PLACES.
LOW TEMPERATURES SATURDAY MORNING WILL DEPEND ON HOW QUICKLY THE
UPPER SYSTEM EXITS FRIDAY NIGHT AND HOW QUICKLY SKIES CLEAR. THE
ECMWF IS SLOWER THAN THE GFS AND ITS SOLUTION WOULD KEEP CLOUDS
ALL NIGHT AND HOLD TEMPERATES UP. WE ARE SIDING WITH THE QUICKER
GFS AND THUS WENT LOWER THAN GUIDANCE FOR LOWS FRIDAY NIGHT.
NICE WEATHER EXPECTED SATURDAY THROUGH SUNDAY WITH A SLIGHT CHANCE
OF SHOWERS SUNDAY EVENING AS THE NEXT UPPER TROUGH APPROACHES.
THAT SYSTEM SHOULD BRING SHOWERS SUNDAY NIGHT AND MONDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1149 AM CDT WED SEP 10 2014
A STRONG SURFACE LOW IS PROJECTED TO TRACK NORTHEAST THIS AFTERNOON
INTO NORTHERN LOWER MICHIGAN AND INTO SOUTHEAST ONTARIO/ SOUTHWEST
QUEBEC TONIGHT. RAIN AND DRIZZLE WILL CONTINUE INTO MIDDLE
AFTERNOON...BUT THEN DIMINISH FROM SOUTHWEST TO NORTHEAST ACROSS THE
REGION. CIGS AND VSBYS WILL MAINLY BE IN THE MVFR/IFR RANGE FOR AS
LONG AS THE RAIN/DRIZZLE CONTINUES. ONCE THE PRECIP EXITS...VSBYS
WILL IMPROVE TO P6SM BUT CIGS WILL REMAIN BETWEEN 1K-2K FEET. VERY
SLOW IMPROVEMENT IS EXPECTED ON WEDNESDAY WITH SOME BREAKING UP OF
THE CLOUD MASS DURING THE AFTERNOON. WINDS WILL SHIFT AROUND TO THE
NORTHWEST THIS AFTERNOON AND REMAIN GUSTY THROUGH THURSDAY MORNING.
&&
.MARINE...
ISSUED AT 242 PM CDT WED SEP 10 2014
NORTHWEST WINDS WILL RAPIDLY STRENGTHEN LATE THIS
AFTERNOON INTO EARLY THIS EVENING BEHIND A DEPARTING LOW PRESSURE
SYSTEM. WITH INCREASING INSTABILITY OVER THE CENTRAL BAY OF GREEN
BAY...MIXING WILL SUPPORT 40 TO 45 KT WINDS AT 925 AND 900MB TO
REACH THE SURFACE. THIS WIND DIRECTION IS ALSO FAVORABLE FOR HIGHER
END GUSTS THROUGH DEATHS DOOR. ISSUE A GALE WARNING FOR THE CENTRAL
BAY AND LAKE MICHIGAN SHORELINE THROUGH 18Z...THOUGH GALES WILL
LIKELY ONLY BE POSSIBLE THROUGH SUNRISE ON THURSDAY.
&&
.HYDROLOGY...
ISSUED AT 242 PM CDT WED SEP 10 2014
NORTH-CENTRAL WISCONSIN PICKED UP THE MOST RAINFALL FOR
THIS EVENT...WITH SCATTERED LOCATIONS REACHING ABOVE 2 INCHES. NO
REPORTS OF FLOODING SO FAR TODAY. AREA RIVERS ARE RISING BUT ALSO
REPORTING NO SIGNIFICANT PROBLEMS. WILL CANCEL THE FLOOD WATCH WITH
THIS ISSUANCE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
MARINE.........MPC
HYDROLOGY......MPC