Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/19/13
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1000 PM MST SAT NOV 16 2013
.UPDATE...
ISSUED AT 950 PM MST SAT NOV 16 2013
SNOW LEVELS WERE AROUND 6.5KFT NORTH TO 8.5KFT SOUTH WITH
CONVECTION PULLING IT LOWER LOCALLY. A QUICK REVIEW OF SNOTEL
SITES TOTAL STORM AMOUNTS: IN EASTERN UTAH MTNS 1-4 INCHES. IN
WESTERN COLORADO IN THE NORTHERN MTNS 6-12 INCHES WITH HIGHER
AMOUNTS NEAR THE WYOMING BORDER AND NORTH SIDE OF THE FLATTOPS.
CENTRAL MTNS 5-10 INCHES WITH 17 INCHES AT SCHOFIELD PASS.
SOUTHERN MTNS 6-15 INCHES FAVORING THE NW SAN JUANS BUT MOLAS PASS
HAS GOTTEN AROUND 15 INCHES. THE SNOW LULL EARLY SATURDAY MORNING
IS EVIDENT IN MOST GRAPHS.
THE 120KT JET NOSE IS ORIENTED FROM POCATELLO TO PAGOSA SPRINGS
THIS EVENING AND WILL LIFT NE OUT OF THE FORECAST AREA BY
SUNRISE. THE UPPER LEVEL SUPPORT FOR THIS STORM IS SHIFTING EAST
OF THE CONTINENTAL DIVIDE. AFTER MIDNIGHT THE FORECAST AREA WILL
GENERALLY BE IN THE COLD ADVECTIVE NW FLOW THAT CAN PRODUCE GOOD
SHALLOW CONVECTIVE SNOWFALL ALONG NW FACING SLOPES. THE
ELKHEADS/PARK/GORE/FLATTOPS/ELKS/WEST ELKS LOOK TO BE FAVORED WITH
SNOWFALL OVERNIGHT WITH THE NEW NAM12 PRODUCING UP TO 6 NEW
INCHES. THE SAN JUANS ARE PROGGED TO RECEIVE LESS AND THE
UNCOMPAHGRE GORGE DOES NOT LOOK FAVORED WITH TEMPERATURES TOO MILD
AND THE MTN TOP WINDS FROM THE WNW WHICH IS NOT FAVORABLE.
SNOW ACCUMULATIONS SUNDAY MORNING LOOK TO BE LIGHT...SO MOST
HIGHLIGHTS WILL LIKELY END WITH SUNRISE. THE NW COLORADO MTNS
HIGHLIGHTS MAY STAY IN EFFECT UNTIL NOON WITH LIGHT SNOW FALLING
IN THE MORNING HOURS.
THE BROAD TROUGH REMAINS OVER THE WEST WITH SOME CHANCE OF MTN
SNOWS TUESDAY AND ESPECIALLY THURSDAY AND PERHAPS INTO NEXT
WEEKEND IF THE GFS IS FOLLOWED.
&&
UPDATE ISSUED AT 525 PM MST SAT NOV 16 2013
JET AXIS WILL TRANSLATE ACROSS NWRN COLORADO TONIGHT...EXPECT THIS
TO ENHANCE OROGRAPHIC SNOW THIS EVENING. EXPECT ONE MORE BURST OF
HEAVY SNOW RATES BEFORE THE FLOW ALOFT BECOMES ANTICYCLONIC AND
THE MOISTURE ERODES FROM THE WEST (ALREADY UNDERWAY). RAP AND HRRR
MODELS SEEM TO INDICATE THAT AREAS EAST OF CRAIG WILL GET DECENT
SNOW ACCUMULATIONS THIS EVENING. ELECTED TO HOIST WINTER WEATHER ADVISORY
FOR THE STEAMBOAT SPRINGS VICINITY. CONSIDERED CRAIG/MEEKER AND
GLENWOOD SPRINGS/EAGLE AREAS AS WELL...BUT APPEARS THAT SNOWFALL
WILL NOT REACH THE 2-4 INCH RANGE FOR THESE LOCATIONS. THE I-70
CORRIDOR IS LESS LIKELY TO EXCEED 1 INCH...BUT SPOTTY ACCUMULATIONS
ON GRASSY SURFACES MAY OCCUR. THE WIND ADVISORY DID NOT PAN OUT
IN THE MOIST POST FRONTAL ENVIRONMENT AND HAS BEEN CANCELLED 1
HOUR EARLY.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 248 PM MST SAT NOV 16 2013
WINTER WEATHER PRODUCTS WILL CONTINUE FOR MOST OF THE WRN CO
MOUNTAINS. ONE SHORTWAVE TROUGH OVER NORTHERN AND CENTRAL CO THIS
AFTERNOON WILL MOVE EAST AND PRODUCE SNOWFALL IN THE MOUNTAINS AND
MIX OF RAIN AND SNOW IN THE HIGHER VALLEYS THROUGH THIS EVENING. A
BRIEF LULL SHOULD OCCUR IN THE LATE EVENING...THEN ANOTHER WEAKER
SHORTWAVE WILL MOVE OVER THE NORTHERN HALF OF CO FROM JUST BEFORE
MIDNIGHT TO JUST BEFORE SUNRISE. SKIES SHOULD CLEAR FROM WEST TO
EAST SUNDAY MORNING. TEMPS...MOISTURE AND COLD ADVECTION ARE ALL
GOOD FOR DECENT SNOW ACCUMULATION. THE 700 MB TEMPS DROPPING TO -6
AND -7 DEGREE C TONIGHT WILL BRING SNOWFALL DOWN TO VALLEY BOTTOMS
LATE. STEADY WNW ALOFT WILL PROVIDE GOOD OROGRAPHIC SUPPORT FOR
SNOWFALL ON WEST AND NORTHWEST FACING SLOPES.
SUNDAY AND SUNDAY NIGHT SHOULD SEE DRAMATICALLY CLEARING SKIES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 248 PM MST SAT NOV 16 2013
MONDAY WILL BE CALM AND UNEVENTFUL AS LIGHT WESTERLY WINDS FROM
WEAK RIDGING TAKE OVER THE WEATHER PATTERN. TEMPERATURES WILL
ADVANCE BACK UP TO NEAR NORMAL MONDAY AND TUESDAY BEFORE A WEAK
WAVE SWINGS BY THE NORTHERN COUNTIES THURSDAY NIGHT...PRODUCING
CLOUDY CONDITIONS AND A TRACE OF PRECIPITATION AT BEST ALONG THE
CO/WY BORDER.
THE 12Z MODELS MOVE IN A WEAK UPPER LEVEL TROUGH WHICH BRINGS A
CHANCE OF PRECIPITATION TO THE HIGHER ELEVATIONS WEDNESDAY
AFTERNOON.
THE BIG STORY IN THE LONG RANGE WILL BE A SYSTEM APPROACHING LATE
WEEK...POTENTIALLY EARLY THURSDAY OR POTENTIALLY FRIDAY DEPENDING
ON WHICH WX MODEL YOU ARE ANALYZING. CONFIDENCE IS LOW AS THE
MODELS DIVERGE ON TIMING AND SPATIAL COVERAGE OF THIS LATE WEEK
FEATURE. NONETHELESS...THE LAST FEW MODEL RUNS HAVE BEEN
SIGNALING A STRONG STORM THROUGHOUT THE GREAT BASIN FOR A COUPLE
OF DAYS NOW SO CONFIDENCE IS MODERATE FOR AN INTERESTING WX SYSTEM
TO UNFOLD LATE IN THE WEEK INTO THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 950 PM MST SAT NOV 16 2013
PRECIPITATION WILL CONTINUE TONIGHT WITH PERIODS OF LOWERED
CIGS AND LOWERED VSBYS. WIDESPREAD MTN SNOW SHOWERS WILL BECOME
SCT TOWARDS MORNING. FOG MAY DEVELOP BETWEEN SNOW SHOWERS KEEPING
VISIBILITY DOWN INTO EARLY SUNDAY MORNING WITH GRADUAL IMPROVEMENT
THEREAFTER. EXPECT WIDESPREAD MVFR CIGS AND VSBYS WITH THE HEAVIER
SHOWERS WITH MOUNTAINS FQTLY OBSCD INTO SUNDAY MORNING. LOCAL IFR TO
LIFR CIGS WILL BE FOUND NEAR THE STRONGER SHOWERS. IN
ADDITION...GUSTY NORTHWEST WINDS WILL BE COMMON ACROSS THE
REGION...WITH SPEEDS EXCEEDING 40 KTS AT AND ABOVE MTN TOP LEVEL.
EXPECT AREAS OF MODERATE TO STRONG TURBULENCE THROUGH THIS PERIOD.
PRECIPITATION AND GUSTY WINDS WILL END THROUGHOUT THE MORNING
SUNDAY FROM WEST TO EAST WITH VFR CONDITIONS EXPECTED SUNDAY
AFTERNOON AND EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST SUNDAY FOR COZ003-005-009-
014-017-018.
WINTER STORM WARNING UNTIL 6 AM MST SUNDAY FOR COZ012-019.
WINTER STORM WARNING UNTIL 11 AM MST SUNDAY FOR COZ004-010-013.
UT...NONE.
&&
$$
UPDATE...JOE
SHORT TERM...CC
LONG TERM...JAM
AVIATION...JOE
AREA FORECAST DISCUSSION
NWS ALBANY NY
630 PM EST MON NOV 18 2013
.SYNOPSIS...
AS COLDER AIR WORKS INTO THE REGION TONIGHT...LAKE ENHANCED RAIN AND
SNOW SHOWERS WILL AFFECT WESTERN AND NORTHERN PARTS OF THE AREA.
TEMPERATURES TOMORROW WILL BE MUCH COLDER THAN RECENT DAYS...WITH A
GUSTY WESTERLY WIND. HIGH PRESSURE PASSING OVER THE AREA WILL ALLOW
FOR DRY WEATHER FOR THE REMAINDER OF THE WORK WEEK...WITH
TEMPERATURES SLOWLY MODERATING BACK TO NORMAL LEVELS.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 530 PM EST...COLD FRONT JUST SLIPPED SOUTH OF I90 PER THE DUAL
POL RADAR DATA. SOME SHOWERS HAVE DEVELOPED ON THE UPSLOPE AREAS OF
THE SCHOHARIE VALLEY AND HELDERBERGS AND WITH THE MEAN WESTERLY
FLOW...THESE ISOLATED SHOWERS HAVE MOVED INTO THE CAPITAL REGION.
FURTHERMORE...TERRAIN ENHANCEMENT ACROSS THE SOUTHERN GREENS HAVE
TOO INITIATED SOME SHOWERS. SO WE WILL INCREASE POPS/WX THROUGH THE
EVENING HOURS AND WATCH LAKE EFFECT ACTIVITY PICK UP DOWNWIND OF
LAKE ONTARIO. PER THE RUC13 LOW LEVEL CONVERGENCE FIELDS...SEEMS
BAND/S/ OF PRECIP SHOULD INCREASE ACROSS CENTRAL HERKIMER COUNTY
WITH A TENDENCY TO SLIDE SOUTHWARD AND WEAKEN OVERNIGHT. THE
CURRENT FORECAST ACROSS THAT PART OF THE CWA REMAINS IN EXCELLENT
SHAPE. OTHERWISE...PER HOURLY TEMPS...DID SLOW DOWN THE NOCTURNAL
CURVE A BIT AND CLOSER TO THE LAMP/LAV AND 2KM HRRR/RUC13.
AS OF 400 PM EST...A STRONG AND VERTICALLY STACKED STORM SYSTEM
OVER WESTERN QUEBEC WILL FILL IN AND WEAKEN OVERNIGHT. WITH THE
TROUGH AXIS CENTERED OVER THE NORTHEASTERN US...THE CYCLONIC FLOW
AROUND THE UPPER LOW WILL PASS OVER THE NORTHERN AND EASTERN GREAT
LAKES. INITIALLY...THE LOW TO MID LEVEL FLOW WILL BE IN A W-SW
DIRECTION...WHICH WILL ALLOW FOR SOME LAKE ENHANCED RAIN AND SNOW
SHOWERS THIS EVENING OVER THE NORTHWESTERN ADIRONDACKS...AS STRONG
CAA DROP 850 HPA TEMPS FROM AROUND 0 TO +4 DEGREES C THIS
AFTN...TO -8 TO -12 DEGREES C BY LATE TONIGHT.
AS BOUNDARY LAYER TEMPS ALSO COOL DOWN...PTYPE WILL CHANGE TO SNOW
ACROSS THE REGION. THE MEAN WIND SHIFTS TO THE WEST DURING THE
OVERNIGHT HOURS AND EVENTUALLY NORTHWEST BY LATE TONIGHT. OUR LOCAL
WFOWRF...AS WELL AS THE LATEST 3KM HRRR...ALL SUGGEST THAT SOME OF
THIS LAKE ENHANCED ACTIVITY WILL PASS ACROSS WESTERN AND NORTHERN
PARTS OF OUR AREA DURING THE OVERNIGHT HOURS. DUE TO THE EXPECTED
AMOUNTS OF SHEAR AND WIND DIRECTION...THE ACTIVITY WILL GENERALLY BE
MULTI-BAND IN NATURE...AND THE INVERSION HEIGHT OF ONLY 2.5-3 KM
WILL PREVENT ANY MEANINGFUL SNOW BANDS FROM OCCURRING.
WHILE THE BULK OF THE ACTIVITY WILL EITHER BY ACROSS THE HIGH
TERRAIN OR THE WESTERN MOHAWK VALLEY...IT/S POSSIBLE THAT A
FLURRY OR SPRINKLE MAY MAKE IT INTO THE HUDSON VALLEY REGION AND
CAPITAL REGION BY LATE TONIGHT. NO SNOW ACCUMULATION IS EXPECTED FOR
THE CAPITAL REGION/HUDSON VALLEY AREAS. ELSEWHERE..SNOW ACCUM WILL
RANGE FROM JUST A DUSTING TO UP TO TWO INCHES ACROSS THE WESTERN
ADIRONDACKS.
TEMPS WILL BE MUCH COLDER FOR TONIGHT THAN RECENT NIGHTS...WITH MINS
RANGING FROM THE MID 20S TO MID 30S. IN ADDITION...THE W-NW SFC
WIND WILL CONTINUE TO BE GUSTY OVERNIGHT...WITH SUSTAINED WINDS OF
10 TO 20 MPH WITH A FEW HIGHER GUSTS...ESP FOR THE MOHAWK VALLEY AND
CAPITAL REGION.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
WITH SFC HIGH PRESSURE BUILDING INTO THE REGION ON TUESDAY AND THE
FLOW ALOFT BECOMING ANTICYCLONIC AND INVERSION HEIGHTS
LOWERING...LAKE EFFECT ACTIVITY WILL END. A FEW SNOW SHOWERS ARE
POSSIBLE EARLY IN THE DAY ACROSS SCHOHARIE COUNTY AND THE EASTERN
CATSKILLS...OTHERWISE IT WILL BE DRY UNDER A PARTLY TO MOSTLY
SUNNY SKY WITH A CONTINUED GUSTY NW BREEZE. TEMPS WILL BE MUCH
COLDER THAN RECENT DAYS...WITH MAX TEMPS IN THE 30S TO MID 40S
ACROSS THE REGION.
AS THE HIGH PRESSURE AREA BUILDS INTO THE REGION FOR TUESDAY
NIGHT...THE WIND WILL DIE OFF AND THIS SHOULD ALLOW FOR GOOD
RADIATIONAL COOLING. TEMPS WILL BE VERY COLD TOMORROW NIGHT...WITH
TEMPS RANGING FROM THE SINGLE DIGITS OVER THE CENTRAL ADIRONDACKS TO
THE TEENS AND LOW 20S ELSEWHERE.
THE HIGH PRESSURE AREA WILL REMAIN SITUATED OVER THE NORTHEAST FOR
WEDNESDAY THROUGH THURSDAY AS WELL...KEEPING THE DRY WEATHER IN
PLACE. MAX TEMPS ON WED WILL BE COLD ONCE AGAIN...WITH 30S AND LOW
40S. HOWEVER...WITH A LIGHT SOUTHERLY WIND DEVELOPING FOR WED NIGHT
AND A FEW MORE CLOUDS ACROSS THE AREA...MIN TEMPS WON/T BE AS COLD
FOR WED NIGHT...WITH 20S OVER THE MAJORITY OF THE AREA. TEMPS WILL
START TO MODERATE ON THURSDAY AS OUR REGION WILL BE IN A RETURN
FLOW AROUND THE SLOWLY DEPARTING HIGH...WITH 40S ACROSS THE ENTIRE
REGION...AND A FEW MORE CLOUDS AROUND...ESP FOR WESTERN PARTS OF
THE AREA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE PERIOD BEGINS WITH THE PASSAGE OF A COLD FRONT THAT WILL BRING
VERY LITTLE MOISTURE AND THUS LITTLE IN THE WAY OF PRECIPITATION.
BUT LOW PRESSURE STRENGTHENING ALONG THE FRONT OVER THE OHIO VALLEY
ON FRIDAY WILL RAPIDLY BUILD MOISTURE INTO THE REGION. THE LOW WILL
TRACK ALONG THE MID-ATLANTIC REGION AND UP THE NEW ENGLAND COAST
FRIDAY NIGHT AND SATURDAY...A TRAJECTORY WHICH COULD RESULT IN OUR
FIRST SIGNIFICANT WINTER WEATHER EVENT...CONSISTING OF A MIXED BAG
OF PRECIPITATION TYPES.
A WEST TO NORTHWESTERLY FLOW BEHIND THE SYSTEM ON SUNDAY WILL DRAW
IN SIGNIFICANTLY COLDER AIR AND TURN ON THE LAKE EFFECT MACHINE...
WITH A GOOD CHANCE FOR SNOW SHOWERS FROM SATURDAY AFTERNOON THROUGH
SUNDAY. THIS COULD BE WET SNOW FOR THE MID HUDSON VALLEY. WITH THE
FLOW WEAKENING SUNDAY NIGHT...LAKE EFFECT SHOULD BECOME LIMITED TO
THE WESTERN ADIRONDACKS...ALTHOUGH MOST REMAINING LOCATIONS WILL
STILL HAVE A SLIGHT CHANCE OF SEEING SOMETHING. BY MONDAY...THINGS
SHOULD BE QUIETED DOWN AS HIGH PRESSURE RIDGES IN FROM THE SOUTHERN
APPALACHIANS. THERE WILL BE A GOOD MIX OF SUN AND CLOUDS MONDAY...B
UT LITTLE BOUNCE BACK IN TEMPERATURES.
LOWS THURSDAY AND FRIDAY NIGHTS WILL RANGE FROM THE MID OR UPPER 20S
TO THE MID 30S. BEHIND THE WEEKEND STORM SYSTEM...LOWS WILL BE IN
THE UPPER TEENS AND THE 20S SATURDAY NIGHT. THEY WILL RANGE FROM
ONLY AROUND 10 DEGREES IN THE ADIRONDACKS...TO AROUND 20 DEGREES IN
THE MID HUDSON VALLEY SUNDAY NIGHT. HIGH TEMPERATURES WILL RANGE
FROM THE MID 30S IN THE WESTERN ADIRONDACKS...TO AROUND 50 DEGREES
IN THE MID HUDSON VALLEY ON FRIDAY...COOLING TO FROM AROUND 30 TO
THE MID 40S ON SATURDAY...THE LOWER 20S TO MID 30S ON SUNDAY...WITH
A COUPLE OF DEGREES OF BOUNCE BACK IN THE NORTHWESTERN HALF OF THE
FORECAST AREA FOR MONDAY. NORMAL TEMPERATURES FOR ALBANY DURING
THIS PERIOD ARE MID 40S FOR HIGHS AND AROUND 30 FOR LOWS.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
A COLD FRONT ALONG WITH UPSLOPE CONDITIONS HAS RESULTED IN SOME
SHOWER DEVELOPMENT BUT ITS RATHER ISOLATED AND HAVE PLACED A VCSH
FOR A FEW HOURS THIS EVENING. FLIGHT CONDITIONS SHOULD REMAIN
VFR...HOWEVER...UPSTREAM SOLID AREA OF STRATUS WAS CLOSE TO MVFR AS
WE WILL TREND THE TAFS IN THIS DIRECTION OVERNIGHT. LAKE EFFECT
ACTIVITY MAY BRING SOME SHOWERS INTO KALB-KGFL-KPSF AS WE WILL PLACE
A PROB30 AROUND 09Z-12Z. DURING THE DAYLIGHT HOURS
TUESDAY...IMPROVING CONDITIONS TO VFR IS EXPECTED.
WINDS ARE ANOTHER ISSUE WITH RATHER GUSTY WEST-NORTHWEST WINDS THAT
WILL CONTINUE TONIGHT AND ESPECIALLY THROUGH THE DAYLIGHT HOURS
TUESDAY WITH GUSTS FREQUENTLY OVER 20KTS.
OUTLOOK...
TUESDAY NIGHT-THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN...RA.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...RA...SN...SLEET.
&&
.HYDROLOGY...
NO HYDRO ISSUES ARE EXPECTED OVER THE NEXT FIVE DAYS.
LAKE EFFECT RAIN AND SNOW SHOWERS WILL AFFECT THE ADIRONDACKS AND
MOHAWK VALLEY TONIGHT...WITH UP TO A QUARTER OF AN INCH OF LIQUID
EQUIVALENT PRECIPITATION EXPECTED. THIS PRECIP WILL HAVE LITTLE TO
NO EFFECT ON AREA WATERWAYS. ANY LAKE EFFECT ACTIVITY WILL END ON
TUESDAY MORNING...AS HIGH PRESSURE BUILDS INTO THE AREA.
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER OVER THE REGION
THROUGH THURSDAY...ALLOWING FOR DRY WEATHER. THIS WILL ALLOW RIVERS
AND STREAMS TO HOLD STEADY OR RECEDE...WITH FLOWS EXPECTED TO BE
AROUND SEASONAL LEVELS. A STORM SYSTEM LOOKS TO MOVE ACROSS THE
REGION SOMETIME BETWEEN FRIDAY AND NEXT WEEKEND...WITH RAIN AND SNOW
POSSIBLE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/BGM
SHORT TERM...FRUGIS
LONG TERM...ELH
AVIATION...BGM
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1002 AM EST SUN NOV 17 2013
.SYNOPSIS...
HIGH PRESSURE ALONG THE EASTERN SEABOARD WILL SLIDE OUT TO SEA
TODAY. A POWERFUL STORM WILL MOVE FROM THE UPPER GREAT LAKES
TOWARD JAMES BAY SUNDAY NIGHT INTO MONDAY. IT WILL BRING WINDY
CONDITIONS TO THE REGION...AND DRIVE A COLD FRONT ACROSS THE
REGION MONDAY MORNING. MUCH COLDER AIR WILL POUR INTO THE REGION
MONDAY NIGHT AND TUESDAY WITH SOME CLOUDS AND SNOW SHOWERS. HIGH
PRESSURE WILL BUILD FROM ONTARIO TO THE GULF COAST TUESDAY...THEN
SETTLE OVER OUR REGION MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
...SLIGHT RISK FROM SPC HAS BEEN EXPANDED TO INCLUDE THE ENTIRE
REGION THROUGH TONIGHT...
AS OF 930 AM EST...LOW STRATUS AND DRIZZLE HAVE QUICKLY EVOLVED
ACROSS THE SOUTHERN HALF OF OUR COUNTY WARNING AREA AND HAVE
EXPANDED THE POPS AND MENTION OF DRIZZLE THROUGH THE REMAINDER OF
THE MORNING HOURS. TEMPERATURE ANALYSIS REVEALS THE COLDER AIR HAS
REMAINED LOCKED IN ACROSS THE EASTERN GREENS OF SOUTHERN VERMONT
WHERE MID-UPR 30S RESIDE WITH THE WESTERN GREENS WELL INTO THE
50S. SO WE HAVE MODIFIED HOURLY TEMPS A BIT TO MATCH UP BETTER
WITH OBSERVATIONS. PER THE 12Z SOUNDING HERE...AMPLE LOW LEVEL
MOISTURE BELOW THE STRENGTHENING INVERSION AROUND H850 AND
INCREASING LOW LEVEL SHEAR HAS BEEN THE RESULT OF THE DRIZZLE
EXPANDING. THIS IS ALSO CONFIRMED WITH THE LATEST VWP REVEALING
AMPLE LOW LEVEL SHEAR AND NO ECHOES IN THE MID LEVELS /TOO DRY/
BETWEEN 8K-11K FEET.
REGIONAL RADAR SHOWS SHOWERS/PERIODS OF RAIN ACROSS WESTERN AND
CENTRAL NY WITH EXPECTATIONS OF THIS REACHING THE WESTERN MOHAWK
VALLEY AND DACKS LATER THIS MORNING. THIS SHOULD EXPAND ACROSS
MOST OF EASTERN NY AND INTO THE UPSLOPE ENHANCEMENTS OF WESTERN
NEW ENGLAND LATER THIS AFTERNOON PER THE LATEST HRRR REFLECTIVITY.
BROAD INCREASING ISENTROPIC LIFT AND WARM MOIST ADVECTION WILL BE
SURE TO KEEP CLOUDS AND THAT EXPANDING AREA OF SHOWERS IN THE
FORECAST WITH LITTLE CHANGES TO THE POPS/WX FOR THE LATER
AFTERNOON HOURS.
A VERY POWERFUL NEGATIVELY TROUGH AND ASSOCIATED COLD FRONT WILL
BE PLOWING THROUGH THE OHIO VALLEY LATER TODAY. THIS FRONT COULD
MAKE WEATHER HISTORY IN THAT IT COULD SPAWN AN UNUSUAL PLETHORA OF
SEVERE WEATHER IN THOSE AREAS...ESPECIALLY CONSIDERING IT IS MID
NOVEMBER. PLEASE REFER TO THE LATEST OUTLOOKS FROM THE STORM
PREDICATION CENTER.
FOR THE AFTERNOON...IT WILL BECOME NOTICEABLY BREEZIER IN MANY
SPOTS...OVERCAST WITH A CHANCE OF SHOWERS AS LOW LEVEL MOISTURE
INCREASES. PWAT VALUES LOOK TO RAMP UP TO AN INCH BY THE END OF THE
DAY...WHICH WOULD MAKE IT ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL.
FORCING WILL REMAIN WEAK TODAY.
HIGH TEMPERATURES TODAY WILL BE SIMILAR TO YESTERDAY/S...GENERALLY
IN THE 55 TO 60 RANGE...WELL ABOVE NORMAL.
THE COLD WILL APPROACH WESTERN NEW YORK THIS EVENING. IT WILL HAVE
RUN OUT OF DAYLIGHT AND REALLY ANY GOOD SURFACE INSTABILITY.
HOWEVER...A STRONG LOW LEVEL JET OF OVER 50 MPH AS LOW AS 2000 FEET
OFF THE DECK WILL BE AHEAD OF IT...AND UP TO 75 MPH ABOUT 5,000 FEET
UP! WHILE SURFACE INSTABILITY NEVER REALLY IS THERE...IT DOES
APPEARS THAT THE SHOWALTER INDEX (INSTABILITY FROM THE 850 MB LEVEL)
WILL GO TO ZERO OR EVEN -1 TO -2 ACROSS PORTIONS OF OUR
REGION...JUST AHEAD OF IT OVERNIGHT.
THE STORM PREDICTION CENTER HAS NOW PLACED A SLIGHT RISK OVER OUR
ENTIRE REGION...NAMELY FOR TONIGHT. AT THIS POINT WE FEEL ANY
CONVECTION WOULD BE LOW TOPPED...SCATTERED AT BEST AND CONFINED TO
NEAR THE ACTUAL PASSAGE OF THE COLD FRONT. HOWEVER...IT COULD EASILY
TAP INTO THE VERY POWERFUL WIND FIELD WHICH COULD TRANSLATE TO WIND
GUSTS OVER 50 MPH!
IT IS A GOOD BET THAT A CONVECTIVE LINE (PERHAPS WITHOUT ANY CLOUD
TO GROUND LIGHTNING STRIKES) WILL DEVELOP AHEAD OF THIS COLD FRONT
AND MOVE QUICKLY THROUGH OUR REGION OVERNIGHT. AGAIN THIS LINE COULD
BRING GUSTY WINDS TO ABOUT 50 MPH OR MORE.
WE HAVE INCLUDED THE CHANCE OF THUNDERSTORMS WITH THE FRONT...SOME
OF WHICH MIGHT CONTAIN GUSTY WINDS. WITH THE HIGH PWATS AND STRONG
CONVERGENCE WITH THE FRONT...RAIN COULD BE HEAVY AT TIMES WITH THE
LINE.
WE DID NOT PUT ANY AREA IN A HIGH WIND WATCH. IT LOOKS TO US AS
MUCH OF THE TIME THE GRADIENT OVERNIGHT WILL BE BELOW WIND
ADVISORY THRESHOLDS DUE TO AN INVERSION OVERHEAD (UNTIL THE COLD
FRONT ARRIVES). ONE EXCEPTION COULD THE ADIRONDACKS WHICH COULD
SEE WIND GUSTS EXCEEDING 40 MPH. HOWEVER...WE WERE NOT CONFIDENT
JUST YET IN PLACING THEM INTO A HIGH WIND WATCH. LATER CREWS MIGHT
BE ISSUING ONE LATER ON TODAY.
THE BETTER CHANCE FOR ANY DAMAGING WINDS WOULD BE ALONG THE SQUALL
LINE SHOULD IT FORM.
OVERNIGHT LOWS WILL REMAIN EXCEPTIONALLY MILD FOR THE TIME OF
YEAR...FALLING LITTLE IF ANY...REMAINING IN THE 50S IN MOST AREAS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MODEL SUITE DURING THIS PERIOD IS VERY MUCH IN AGREEMENT.
INTENSE STORM IS VERTICAL AND LIFTING QUICKLY NE ACROSS
ONTARIO/QB BORDER REGIONS MONDAY MORNING AS ITS CDFNT HAS CLEARED
THE FCA. CLEARING SHOULD BE RAPID ACROSS FCA AS DRY SLOT
OVERSPREADS REGION. SFC WIND GRADIENT SHIFTS TO WEST AND REMAINS
ABOUT 12MB MON ACROSS NYS. SO BRISK WEST WINDS WITH SOME DOWN
SLOPING AND COMPRESSION WILL FOLLOW FROPA WITH A MILD BUT BRISK
DAY. TEMPS WILL REMAIN IN THE 50S AND LOW TO MID 60S S&E OF ALB.
2NDRY CDFNT AND A STRONG 500 HPA SHORT WV WILL APPROACH TWRD
EVENING WITH CLOUDS INCR FM NW TO SE.
MON NT FLOW WILL SHIFT TO NW BEHIND SECONDARY CDFNT...THEN N AS TROF
AXIS MOVES ACROSS RGN AND CAA INCR WITH SFC HIGH BUILDING FM OH
VLY TO GRTLKS. MODEST LK EFFECT RESPONSE AND UPSLOPE N FLOW OVER
HIR TRRN WILL INCR CLOUDS AND RESULT IN -SHSN N AND W MON NT INTO
TUE MRNG. THIS ACTIVITY WILL END QUICKLY TUESDAY MORNING AS TROF
SHIFTS EAST...UVM FM TROF BCMS DVM...AND SFC FLOW IS MOSTLY
N..BUT WINDS WILL STILL BE VERY BRISK TUES.
THE PERIOD ENDS WITH TRANQUILITY AS SFC HIGH CENTER SHIFTS OVER
RGN WED MORNING...AND RIDGING BUILDS OVER NE USA MIDWEEK. WITH
IDEAL RADIATIONAL COOLING...CLEAR SKIES...LIGHT WINDS...14 HOURS
OF NIGHT...TEMPS WILL DROP TO SINGLE DIGITS N TO LOW 20S SE. MOS
MDL MINS HAVE BEEN TRENDING COLDER FOR THIS PERIOD SINCE LATE LAST
WEEK.
WED WILL START COLD AND REMAIN CHILLY WITH MAX TEMPS 5-10 DEG
BLOW NORMAL. BUT WITH LIGHT WINDS AND LOTS OF SUN WILL BE
RELATIVELY PLEASANT FOR MID NOV.
WED NT WILL BE ANOTHER COLD ONE UNDER THE SFC HIGH CENTER WITH
LOWS 10 TO LOW 20S.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE PERIOD FEATURES A FAST ZONAL 500HPA FLOW OVER N TIER OF
USA...ENDING WITH A BREAKING WAVE AND DEEPENING TROF OVER THE EAST.
AS SUCH ITS NOT A HIGH CONFIDENCE EFP AFTER FRIDAY MORNING.
MODEL SUITE BEGINS IN AGREEMENT AT FIRST...BUT SPREADS WIDELY BY END
OF PERIOD WITH MAINLY TIMING ISSUES BETWEEN ECMWF/GEM AND GFS. THUR
500HPA RIDGE FLATTENS INTO ZONAL FLOW. HVWR SFC HIGH REMAINS ALONG E
SEABOARD WITH LT S-SW SFC FLOW. RESULT IS FAIR DAY WITH A SLIGHT
MODERATION IN TEMPS TO NR NORMALS. THU NT A WEAK BACKDOOR CDNFT
DROPS S ACROSS RGN WITH REINFORCING SHOT OF COLD AIR. HWVR CDFNTS
MAGNITUDE AND WIND GRADIENT BEHIND IT OVR RGN FRI VARIES GREATLY FM
BTWN THE ECMWF/GEM/GFS AND HPC. ALL THE GUIDS HAS A GENERALLY FAIR
BUT COOLER DAY. THE EFP PERIOD ENDS WITH A SERIES OF SHORT WVS
DIGGING OUT A TROF AND 500HPA CUT OFF OVER THE EAST. THE GFS PUSHES
THIS STRONG CLIPPER TYPE SYSTEM THROUGH REGION FRI NT INTO SAT
MORNING...WITH STRONG CAA FOR THE WEEKEND. THE ECMWF/GEM AS FAR AS
IT GOES KEEP THE FLOW ZONAL AT 500HPA ...WITH SFC HIGH OVER RGN
FRIDAY AND FRI NT. THESE MODELS HAVE THIS STRONG FROPA AND CAA
COMING THROUGH A DAY LATER ON SAT NT AND SUN. HPC GUIDANCE IS MORE
IN LINE WITH THIS LATER SOLUTION...AND GIVEN LOW CONFIDENCE AT END
OF EFP...SEE NO REASON WHY NOT TO GO WITH IT. SO WILL POPULATE WITH
HPC ON THIS UPDATE.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
A STRONG COLD FRONT WITH A LIKELY LINE OF SHOWERS AND POSSIBLE WILL
IMPACT THE TERMINAL OVERNIGHT.
LOW END MVFR AND IFR CONDITIONS HAVE DEVELOPED AS WE DID AMMEND
THE TAFS ACCORDINGLY. THESE CIGS WILL LIKELY BOUNCE BETWEEN
CATEGORIES FOR THE REMAINDER OF THE DAY ALONG WITH AN INCREASE IN
THE LOW LEVEL JET THAT WILL BE ADDRESSED IN FUTURE UPDATES.
CIGS LOOK TO LIFT BACK TO THE HIGH END OF MVFR LATER IN THE MORNING
AFTER THE MORNING PEAK WITH OVERALL DECENT SURFACE VISIBILITY AS ANY
MIST DISSIPATES. HOWEVER...PATCHES OF DRIZZLE COULD DEVELOP DURING
THE AFTERNOON (NOT REFLECTED IN THE TAFS) BUT USED VCSH AT THAT TIME.
A LIGHT WIND WILL BECOME SOUTH OR SOUTHEAST AROUND 10KTS LATER ON
SUNDAY...WITH GUSTS UP TO 20KTS MAINLY AT KALB AND KPSF.
AS A STRONG COLD FRONT APPROACHES TO NIGHT...THE SOUTH SURFACE
WIND WILL CONTINUE AT 10-15 KTS. STRONGER WINDS ALOFT PROMPTED US TO
INCLUDE WIND SHEAR AT THE KGFL TAF AFTER 00Z. AT THIS POINT...IT
WILL BE A CLOSE CALL AT THE OTHER TAF SITES BUT DID NOT INCLUDE IT
IN JUST YET AS THE DIFFERENTIAL BETWEEN THE SURFACE WIND AND 2000
FEET DID NOT QUITE MEET THE OFFICIAL THRESHOLD...BUT AGAIN IT IS
VERY CLOSE AND PILOTS SHOULD LOOK FOR ANY UPDATES.
SHOWERS SUNDAY NIGHT COULD REDUCE CONDITIONS TO IFR AT
TIMES...ALTHOUGH MVFR LOOKS TO PREDOMINATE. THERE LOOKS TO BE A LINE
OF GUSTY SHOWERS (AND POSSIBLY EVEN THUNDERSTORMS) WITH THE COLD
FRONT AS IT LOOKS TO CROSS THE TAFS BETWEEN ABOUT 08Z-12Z OVERNIGHT.
THE BIGGEST CONCERN COULD BE STRONG GUSTY WINDS ALONG AND JUST
BEHIND THIS FEATURE. WE REFLECTED THIS TREND IN THE TAFS. THE EXACT
TIMING WILL LIKELY BE ADJUSTED A LITTLE AS THIS LINE APPROACHES AND
THE WINDS COULD CERTAINLY BE BRIEFLY STRONGER THAN THE 30KT GUSTS WE
ARE CURRENTLY ADVERTISING.
OUTLOOK...
MONDAY NIGHT AND TUESDAY: LOW OPERATIONAL IMPACT.BREEZY
TUESDAY NIGHT THROUGH THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
TODAY WILL BE THE LAST DAY WE ISSUE THE NFDRS FORECASTS AT 300 PM
THIS AFTERNOON. TOMORROW MORNING WILL BE LAST ISSUANCE OF THE FIRE
WEATHER PRODUCT AND FIRE WEATHER DISCUSSION FOR THIS YEAR.
WE WILL CONTINUE TO POPULATE FIRE WEATHER GRIDS TWO TIMES A DAY FOR
THE REMAINDER OF THE YEAR.
FOR TODAY...HIGH HUMIDITY LEVELS WILL PERSIST ALONG WITH PLENTY OF
CLOUDS...SOME PATCHY MORNING DRIZZLE AND THE CHANCE FOR AFTERNOON
SHOWERS. A SOUTHERLY WIND WILL INCREASE TO 10 TO 15 MPH BY
AFTERNOON.
A STRONG COLD FRONT WILL WORK ACROSS THE REGION OVERNIGHT LIKELY
BRINGING A SQUALL LINE OF HEAVY SHOWERS AND POSSIBLY SOME EMBEDDED
THUNDERSTORMS. MOST PLACES SHOULD RECEIVE A QUARTER INCH OF RAIN OR
MORE. WIND GUSTS COULD BRIEFLY REACH 40 MPH OR MORE WITH THIS LINE.
MOST PLACES WILL DRY OUT QUICKLY BEHIND THE FRONT...ALTHOUGH SOME
SHOWERS COULD LINGER ACROSS MAINLY THE ADIRONDACKS. IT WILL BE
SOMEWHAT WINDY WITH SOUTHWEST WIND BECOMING WESTERLY 10 TO 20 MPH
WITH A FEW HIGHER GUSTS.
DRY AND COLDER WEATHER WILL FOLLOW FOR MUCH OF THE REMAINDER OF THE
WORKWEEK.
&&
.HYDROLOGY...
NO FLOODING OF RIVERS OR STREAMS ARE EXPECTED OVER THE NEXT FIVE
DAYS.
HOWEVER...RAIN COULD FALL HEAVILY ENOUGH OVERNIGHT TO PRODUCE AREAS
OF PONDING WHERE FALLEN LEAVES MIGHT CLOG DRAINS.
TODAY WILL FEATURE SOME PATCHES OF LIGHT DRIZZLE OR RAIN SHOWERS
WITH MOST AREAS EXPECTED TO RECEIVE A TENTH OF AN INCH OF RAINFALL
OR LESS.
A LINE OF SHOWERS AND POSSIBLY EVEN A FEW THUNDERSTORMS WILL WORK
ACROSS THE REGION OVERNIGHT...BRINGING MORE SIGNIFICANT RAINFALL.
RIGHT NOW WE BELIEVE MOST AREAS WILL HAVE AROUND A HALF INCH OF
RAINFALL. THIS WOULD BE ENOUGH TO PRODUCE SOME MINOR RISES ON MANY
RIVERS AND STREAMS SINCE VEGETATION IS NOW COMPLETELY DORMANT.
HOWEVER...RIVERS AND STREAMS WERE RUNNING A BIT BELOW NORMAL...SO IS
VERY UNLIKELY ANY OF THEM WOULD REACH NEAR BANKFULL SINCE IT LOOKS
AS IF THE RAIN IS OUT OF HERE FOR THE MOST PART COME MONDAY.
A FEW ADDITIONAL LIGHT SHOWERS COULD FALL ACROSS THE ADIRONDACKS
THROUGH EARLY TUESDAY...WITH ADDITIONAL AMOUNTS OF RAINFALL UNDER A
QUARTER OF AN INCH. LITTLE OR NO ADDITIONAL RESPONSES ARE EXPECTED
ON ANY OF THE WATERSHEDS IN OUR REGION. OTHERWISE...WE ARE DRY AGAIN
THROUGH MUCH OF THE UPCOMING WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM/SNYDER
NEAR TERM...HWJIV/BGM
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...HWJIV/BGM
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1108 AM EST SUN NOV 17 2013
...DENSE SEA FOG OFF THE COAST OF FAR NORTH COASTAL GEORGIA AND
FAR SOUTH COASTAL SOUTH CAROLINA...
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE
NORTHEAST THROUGH TONIGHT. A STRONG COLD FRONT WILL THEN MOVE
THROUGH LATE MONDAY FOLLOWED BY COLDER HIGH PRESSURE BUILDING FROM
THE NORTH THROUGH THE MIDDLE OF THE WEEK. ANOTHER COLD FRONT COULD
MOVE THROUGH SATURDAY WITH HIGH PRESSURE RETURNING FOR THE END OF
NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISENTROPICALLY INDUCED SHOWER ACTIVITY HAS BEEN DIMINISHING OVER
THE PAST TWO HOURS. SHORT TERM GUIDANCE IS NOT OVERLY EXCITED
ABOUT THE PROSPECTS FOR MEASURABLE RAINFALL THROUGH EARLY
AFTERNOON ANYWHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA...HOWEVER RAP ISENTROPIC FIELDS SHOW MODEST 295-305K
ISENTROPIC ASSENT GOING THROUGH THE DAY. WILL LOWER POPS OUT OF
THE LIKELY CATEGORY INTO THE MID-RANGE CHANCE CATEGORY ACROSS THE
SOUTH BASED ON CURRENT RADAR DATA. THERE ARE SOME SIGNALS THAT A
LOOSELY CONCENTRATED AREA OF SHOWERS COULD BRUSH THE CHARLESTON
METRO AREA BY EARLY AFTERNOON...BUT AGAIN...MODELS ARE NOT OVERLY
IMPRESSED. WILL SHOW 30-40 PERCENT POPS AREA WIDE TODAY...WITH
INCREASING POPS ACROSS THE NORTH AS MORE ORGANIZED SHOWER ACTIVITY
ATTEMPTS TO APPROACH THE SOUTH CAROLINA ZONES LATER THIS AFTERNOON
AS SHORTWAVE ENERGY APPROACHES.
EXTENSIVE CLOUD COVER WILL LIMIT HIGHS SOMEWHAT TODAY...ALTHOUGH
PRE-FRONTAL COMPRESSIONAL HEATING AND ONGOING WARM AIR ADVECTION
COULD COUNTERACT THE LACK OF STRONG INSOLATION. WILL MAINTAIN
HIGHS IN THE MID 70S FOR NOW.
THE REMAINDER OF THE FORECAST IS ON TRACK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A SOUTH-SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD
FRONT FROM THE NORTHWEST WILL KEEP DEEP LAYERED MOISTURE IN PLACE
ACROSS THE REGION. PRE-FRONTAL SHOWERS ARE EXPECTED TO OCCUR AND
THE FORECAST SHOWS A CHANCE OF SHOWERS FOR THE ENTIRE FORECAST
AREA. HAVE REMOVED THE MENTION OF THUNDERSTORMS DUE TO LIMITED
INSTABILITY BECAUSE OF NOCTURNAL COOLING. IT SHOULD BE A
RELATIVELY WARM NIGHT GIVEN THE SOUTH-SOUTHWEST FLOW AND EXTENSIVE
CLOUD COVER...WITH LOWS FORECAST IN THE MID 60S IN MOST AREAS.
MONDAY THROUGH WEDNESDAY...A COLD FRONT IS SLATED TO APPROACH
FROM THE WEST MONDAY MORNING AND THEN SLOWLY PUSH TOWARD THE COAST
DURING THE AFTERNOON...ALTHOUGH THERE IS STILL SOME UNCERTAINTY
REGARDING THE TIMING OF THIS FEATURE. OVERALL WE THINK THE BEST
RAIN CHANCES WILL COME IN THE MORNING WHEN THE DEEPEST MOISTURE
WILL BE IN PLACE...BUT THE NAM12 RE-FIRES SOME CONVECTION IN THE
AFTERNOON ALONG AND AHEAD OF A SLOWER-MOVING FRONT AS TEMPERATURES
WARM TO NEAR 80 DEGREES. THUS...WOULD NOT BE SURPRISED TO SEE A
FEW GUSTY THUNDERSTORMS DURING THE AFTERNOON IF THE FRONT IS
INDEED SLOWER TO PASS THROUGH. MUCH DRIER AND COOLER AIR WILL PUSH
IN FROM THE NORTH MONDAY NIGHT BEHIND THE FRONT...CONTINUING
THROUGH WEDNESDAY. THIS WILL LEAD TO BREEZY NORTH/NORTHEAST WINDS
TUESDAY AND WEDNESDAY...ESPECIALLY ALONG THE COAST.
LAKE WINDS...SMALL RISK FOR LOW-END ADVISORY CONDITIONS DEVELOPING
ON LAKE MOULTRIE LATE MONDAY NIGHT INTO EARLY TUESDAY AS STRONG HIGH
PRESSURE BUILDS IN FROM THE NORTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
COOL/DRY HIGH PRESSURE WILL PERSIST NORTH OF THE AREA THROUGH THE
MIDDLE OF THE WEEK BEFORE BREAKING DOWN LATE IN THE WEEK AS A COLD
FRONT APPROACHES. THERE IS NOW MUCH BETTER AGREEMENT BETWEEN THE GFS
AND ECMWF SHOWING THE FRONT PUSHING THROUGH SATURDAY WITH
COOLER/DRIER HIGH PRESSURE BUILDING BACK IN FOR THE END OF THE
WEEKEND. OTHERWISE...IT WILL BE BREEZY THROUGH MID WEEK DUE TO THE
TIGHT PRESSURE GRADIENT...WITH HIGHEST WINDS CLOSER TO THE COAST.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
GIVEN EXPANSIVE MID AND UPPER LEVELS CLOUDS...THE THREAT FOR FOG
HAS ENDED AT THE TERMINALS THIS MORNING.
KCHS...VFR CONDITIONS ARE EXPECTED TO PREVAIL TODAY...ALTHOUGH
THERE IS THE POTENTIAL FOR CEILINGS TO DROP TO MVFR LEVELS AT
TIMES. SCATTERED SHOWERS ARE EXPECTED TO DEVELOP THIS AFTERNOON
AND PERSIST INTO EARLY THIS EVENING AS A DISTURBANCE CROSSES THE
REGION...THUS HAVE INCLUDED VICINITY SHOWERS IN THE TAF/S FROM
18-02Z. MODELS ARE IN FAIRLY GOOD AGREEMENT INDICATING THE
POTENTIAL FOR IFR CEILINGS AND MVFR VISIBILITIES FROM ABOUT 02Z
THROUGH THE END OF THE FORECAST PERIOD AT 12Z MONDAY.
KSAV...STRATUS ACROSS SOUTHERN GEORGIA WILL LIFT NORTHWARD THIS
MORNING AND IS EXPECTED TO IMPACT THE TERMINAL FROM ABOUT 14-18Z.
DURING THIS TIME...THE TAF INDICATES PREVAILING MVFR CEILINGS WITH
TEMPORARY IFR CEILINGS FROM 14-16Z. THEN...CEILINGS SHOULD LIFT TO
LOW-END VFR LEVELS THROUGH THE REMAINDER OF THE DAY...ALTHOUGH
THEY COULD DROP TO MVFR LEVELS AT TIMES. SCATTERED SHOWERS ARE
EXPECTED TO DEVELOP THIS AFTERNOON AND PERSIST INTO EARLY THIS
EVENING AS A DISTURBANCE CROSSES THE REGION...THUS HAVE INCLUDED
VICINITY SHOWERS IN THE TAF/S FROM 18-02Z. MODELS ARE IN FAIRLY
GOOD AGREEMENT INDICATING THE POTENTIAL FOR IFR CEILINGS AND MVFR
VISIBILITIES FROM ABOUT 02Z THROUGH THE END OF THE FORECAST PERIOD
AT 12Z MONDAY.
EXTENDED AVIATION OUTLOOK...MVFR...POSSIBLY IFR...CONDITIONS MON
ALONG AND AHEAD OF A COLD FRONT. OTHERWISE...MAINLY VFR THROUGH
FRIDAY...ALTHOUGH BREEZY/GUSTY CONDITIONS ARE EXPECTED
TUESDAY/WEDNESDAY AND POSSIBLY THURSDAY.
&&
.MARINE...
TODAY...TYBEE ISLAND WEBCAMS AND REPORTS FROM THE TYBEE ISLAND
COAST GUARD INDICATE AN AREA OF DENSE SEA FOG HAS DEVELOPED FROM
ROUGHLY HILTON HEAD SOUTH TO SAINT CATHERINES SOUND. ITS UNCLEAR
HOW FAR OFFSHORE THE FOG EXTENDS WITH MID-LEVEL CLOUDS BLOCKING
VIEWS FROM SATELLITE...BUT HAVE HOISTED A MARINE DENSE FOG
ADVISORY FOR THE GEORGIA NEARSHORE WATERS AND THE FAR SOUTHERN
SOUTH CAROLINA NEARSHORE WATERS UNTIL 4 PM EST.
A COASTAL TROUGH WILL DISSIPATE EAST OF THE WATERS...ALLOWING
A RETURN FLOW TO DEVELOP ALONG THE PERIPHERY OF HIGH PRESSURE
NORTHEAST OF THE REGION. THIS WILL CAUSE WINDS TO GRADUALLY VEER
SOUTHEAST OR SOUTH THROUGH THE DAY. WIND SPEEDS WILL GENERALLY BE
AROUND 10 KT OR LESS DUE TO THE LACK ANY SIGNIFICANT PRESSURE
GRADIENT. SEAS WILL REMAIN IN THE 2-4 FT RANGE.
TONIGHT...A SOUTH-SOUTHWEST FLOW WILL STRENGTHEN TO AS MUCH AS
10-15 KT IN ADVANCE OF AN APPROACHING COLD FRONT FROM THE
NORTHWEST. SEAS WILL BUILD BY ABOUT A FOOT OR SO AS A RESULT.
PERHAPS THE BIGGEST CONCERN TONIGHT IS FOR THE POTENTIAL FOR SEA
FOG TO FORM AS DEWPOINTS SURGE IN THE UPPER 60S ON THE
STRENGTHENING SOUTHERLY FLOW. GIVEN CONSIDERABLY COOLER SEA SURFACE
TEMPERATURES...THIS WILL RESULT IN CONDITIONS FAVORABLE FOR SEA
FOG TO FORM OR ADVECT IN FROM THE SOUTH TONIGHT AND COULD REDUCE
VISIBILITIES ENOUGH TO WARRANT A DENSE FOG ADVISORY FOR PORTIONS
OF THE NEAR SHORE COASTAL WATERS AND CHARLESTON HARBOR.
MONDAY THROUGH FRIDAY...A COLD FRONT WILL PUSH THROUGH LATE MONDAY
WITH WINDS/SEAS INCREASING GREATLY MONDAY NIGHT FROM THE NORTH AS
STRONG HIGH PRESSURE BUILDS INTO THE OHIO VALLEY. SOLID SMALL CRAFT
ADVISORY CONDITIONS ARE ANTICIPATED FOR ALL WATERS INTO THURSDAY
WITH THE POTENTIAL FOR GALE FORCE WINDS...MAINLY BEYOND 20 NM FROM
SHORE.
INCREASING LOW-LEVEL MOISTURE ATOP THE RELATIVELY COOL NEARSHORE
WATERS COULD PRODUCE SOME SEA FOG MONDAY UNTIL THE FRONT PUSHES
THROUGH.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ352-
354.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
915 AM EST SUN NOV 17 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE
NORTHEAST THROUGH TONIGHT. A STRONG COLD FRONT WILL THEN MOVE
THROUGH LATE MONDAY FOLLOWED BY COLDER HIGH PRESSURE BUILDING FROM
THE NORTH THROUGH THE MIDDLE OF THE WEEK. ANOTHER COLD FRONT COULD
MOVE THROUGH SATURDAY WITH HIGH PRESSURE RETURNING FOR THE END OF
NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISENTROPICALLY INDUCED SHOWER ACTIVITY HAS BEEN DIMINISHING OVER
LAST FOR THE PAST TWO HOURS. SHORT TERM GUIDANCE IS NOT OVERLY
EXCITED ABOUT THE PROSPECTS FOR MEASURABLE RAINFALL THROUGH EARLY
AFTERNOON ANYWHERE ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST
GEORGIA...HOWEVER RAP ISENTROPIC FIELDS SHOW MODEST 295-305K
ISENTROPIC ASSENT GOING THROUGH THE DAY. WILL LOWER POPS OUT OF
THE LIKELY CATEGORY INTO THE MID-RANGE CHANCE CATEGORY ACROSS THE
SOUTH BASED ON CURRENT RADAR DATA. THERE ARE SOME SIGNALS THAT A
LOOSELY CONCENTRATED AREA OF SHOWERS COULD BRUSH THE CHARLESTON
METRO AREA BY EARLY AFTERNOON...BUT AGAIN...MODELS ARE NOT OVERLY
IMPRESSED. WILL SHOW 30-40 PERCENT POPS AREA WIDE TODAY...WITH
INCREASING POPS ACROSS THE NORTH AS MORE ORGANIZED SHOWER ACTIVITY
ATTEMPTS TO APPROACH THE SOUTH CAROLINA ZONES LATER THIS AFTERNOON
AS SHORTWAVE ENERGY APPROACHES.
EXTENSIVE CLOUD COVER WILL LIMIT HIGHS SOMEWHAT TODAY...ALTHOUGH
PRE-FRONTAL COMPRESSIONAL HEATING AND ONGOING WARM AIR ADVECTION
COULD COUNTERACT THE LACK OF STRONG INSOLATION. WILL MAINTAIN
HIGHS IN THE MID 70S FOR NOW.
THE REMAINDER OF THE FORECAST IS ON TRACK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...A SOUTH-SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD
FRONT FROM THE NORTHWEST WILL KEEP DEEP LAYERED MOISTURE IN PLACE
ACROSS THE REGION. PRE-FRONTAL SHOWERS ARE EXPECTED TO OCCUR AND
THE FORECAST SHOWS A CHANCE OF SHOWERS FOR THE ENTIRE FORECAST
AREA. HAVE REMOVED THE MENTION OF THUNDERSTORMS DUE TO LIMITED
INSTABILITY BECAUSE OF NOCTURNAL COOLING. IT SHOULD BE A
RELATIVELY WARM NIGHT GIVEN THE SOUTH-SOUTHWEST FLOW AND EXTENSIVE
CLOUD COVER...WITH LOWS FORECAST IN THE MID 60S IN MOST AREAS.
MONDAY THROUGH WEDNESDAY...A COLD FRONT IS SLATED TO APPROACH
FROM THE WEST MONDAY MORNING AND THEN SLOWLY PUSH TOWARD THE COAST
DURING THE AFTERNOON...ALTHOUGH THERE IS STILL SOME UNCERTAINTY
REGARDING THE TIMING OF THIS FEATURE. OVERALL WE THINK THE BEST
RAIN CHANCES WILL COME IN THE MORNING WHEN THE DEEPEST MOISTURE
WILL BE IN PLACE...BUT THE NAM12 RE-FIRES SOME CONVECTION IN THE
AFTERNOON ALONG AND AHEAD OF A SLOWER-MOVING FRONT AS TEMPERATURES
WARM TO NEAR 80 DEGREES. THUS...WOULD NOT BE SURPRISED TO SEE A
FEW GUSTY THUNDERSTORMS DURING THE AFTERNOON IF THE FRONT IS
INDEED SLOWER TO PASS THROUGH. MUCH DRIER AND COOLER AIR WILL PUSH
IN FROM THE NORTH MONDAY NIGHT BEHIND THE FRONT...CONTINUING
THROUGH WEDNESDAY. THIS WILL LEAD TO BREEZY NORTH/NORTHEAST WINDS
TUESDAY AND WEDNESDAY...ESPECIALLY ALONG THE COAST.
LAKE WINDS...SMALL RISK FOR LOW-END ADVISORY CONDITIONS DEVELOPING
ON LAKE MOULTRIE LATE MONDAY NIGHT INTO EARLY TUESDAY AS STRONG HIGH
PRESSURE BUILDS IN FROM THE NORTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
COOL/DRY HIGH PRESSURE WILL PERSIST NORTH OF THE AREA THROUGH THE
MIDDLE OF THE WEEK BEFORE BREAKING DOWN LATE IN THE WEEK AS A COLD
FRONT APPROACHES. THERE IS NOW MUCH BETTER AGREEMENT BETWEEN THE GFS
AND ECMWF SHOWING THE FRONT PUSHING THROUGH SATURDAY WITH
COOLER/DRIER HIGH PRESSURE BUILDING BACK IN FOR THE END OF THE
WEEKEND. OTHERWISE...IT WILL BE BREEZY THROUGH MID WEEK DUE TO THE
TIGHT PRESSURE GRADIENT...WITH HIGHEST WINDS CLOSER TO THE COAST.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
GIVEN EXPANSIVE MID AND UPPER LEVELS CLOUDS...THE THREAT FOR FOG
HAS ENDED AT THE TERMINALS THIS MORNING.
KCHS...VFR CONDITIONS ARE EXPECTED TO PREVAIL TODAY...ALTHOUGH
THERE IS THE POTENTIAL FOR CEILINGS TO DROP TO MVFR LEVELS AT
TIMES. SCATTERED SHOWERS ARE EXPECTED TO DEVELOP THIS AFTERNOON
AND PERSIST INTO EARLY THIS EVENING AS A DISTURBANCE CROSSES THE
REGION...THUS HAVE INCLUDED VICINITY SHOWERS IN THE TAF/S FROM
18-02Z. MODELS ARE IN FAIRLY GOOD AGREEMENT INDICATING THE
POTENTIAL FOR IFR CEILINGS AND MVFR VISIBILITIES FROM ABOUT 02Z
THROUGH THE END OF THE FORECAST PERIOD AT 12Z MONDAY.
KSAV...STRATUS ACROSS SOUTHERN GEORGIA WILL LIFT NORTHWARD THIS
MORNING AND IS EXPECTED TO IMPACT THE TERMINAL FROM ABOUT 14-18Z.
DURING THIS TIME...THE TAF INDICATES PREVAILING MVFR CEILINGS WITH
TEMPORARY IFR CEILINGS FROM 14-16Z. THEN...CEILINGS SHOULD LIFT TO
LOW-END VFR LEVELS THROUGH THE REMAINDER OF THE DAY...ALTHOUGH
THEY COULD DROP TO MVFR LEVELS AT TIMES. SCATTERED SHOWERS ARE
EXPECTED TO DEVELOP THIS AFTERNOON AND PERSIST INTO EARLY THIS
EVENING AS A DISTURBANCE CROSSES THE REGION...THUS HAVE INCLUDED
VICINITY SHOWERS IN THE TAF/S FROM 18-02Z. MODELS ARE IN FAIRLY
GOOD AGREEMENT INDICATING THE POTENTIAL FOR IFR CEILINGS AND MVFR
VISIBILITIES FROM ABOUT 02Z THROUGH THE END OF THE FORECAST PERIOD
AT 12Z MONDAY.
EXTENDED AVIATION OUTLOOK...MVFR...POSSIBLY IFR...CONDITIONS MON
ALONG AND AHEAD OF A COLD FRONT. OTHERWISE...MAINLY VFR THROUGH
FRIDAY...ALTHOUGH BREEZY/GUSTY CONDITIONS ARE EXPECTED
TUESDAY/WEDNESDAY AND POSSIBLY THURSDAY.
&&
.MARINE...
TODAY...A COASTAL TROUGH WILL DISSIPATE EAST OF THE WATERS...ALLOWING
A RETURN FLOW TO DEVELOP ALONG THE PERIPHERY OF HIGH PRESSURE
NORTHEAST OF THE REGION. THIS WILL CAUSE WINDS TO GRADUALLY VEER
SOUTHEAST OR SOUTH THROUGH THE DAY. WIND SPEEDS WILL GENERALLY BE
AROUND 10 KT OR LESS DUE TO THE LACK ANY SIGNIFICANT PRESSURE
GRADIENT. SEAS WILL REMAIN IN THE 2-4 FT RANGE.
TONIGHT...A SOUTH-SOUTHWEST FLOW WILL STRENGTHEN TO AS MUCH AS
10-15 KT IN ADVANCE OF AN APPROACHING COLD FRONT FROM THE
NORTHWEST. SEAS WILL BUILD BY ABOUT A FOOT OR SO AS A RESULT.
PERHAPS THE BIGGEST CONCERN TONIGHT IS FOR THE POTENTIAL FOR SEA
FOG TO FORM AS DEWPOINTS SURGE IN THE UPPER 60S ON THE
STRENGTHENING SOUTHERLY FLOW. GIVEN CONSIDERABLY COOLER SEA SURFACE
TEMPERATURES...THIS WILL RESULT IN CONDITIONS FAVORABLE FOR SEA
FOG TO FORM OR ADVECT IN FROM THE SOUTH TONIGHT AND COULD REDUCE
VISIBILITIES ENOUGH TO WARRANT A DENSE FOG ADVISORY FOR PORTIONS
OF THE NEAR SHORE COASTAL WATERS AND CHARLESTON HARBOR.
MONDAY THROUGH FRIDAY...A COLD FRONT WILL PUSH THROUGH LATE MONDAY
WITH WINDS/SEAS INCREASING GREATLY MONDAY NIGHT FROM THE NORTH AS
STRONG HIGH PRESSURE BUILDS INTO THE OHIO VALLEY. SOLID SMALL CRAFT
ADVISORY CONDITIONS ARE ANTICIPATED FOR ALL WATERS INTO THURSDAY
WITH THE POTENTIAL FOR GALE FORCE WINDS...MAINLY BEYOND 20 NM FROM
SHORE.
INCREASING LOW-LEVEL MOISTURE ATOP THE RELATIVELY COOL NEARSHORE
WATERS COULD PRODUCE SOME SEA FOG MONDAY UNTIL THE FRONT PUSHES
THROUGH.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
621 AM EST SUN NOV 17 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST WILL DIRECT AN
ONSHORE FLOW INTO THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL MOVE THROUGH THE AREA EARLY MONDAY. COLD
HIGH PRESSURE WILL FOLLOW THE FRONT AND DOMINATE THROUGH THE
MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DENSE FOG COVERED MUCH OF THE FORECAST AREA EARLY THIS MORNING.
SHALLOW LOW-LEVEL MOISTURE AND LIGHT WIND HELPED CAUSE THE FOG.
BASED ON THE HRRR GUIDANCE EXPECT IMPROVING VISIBILITIES BEGINNING
AROUND 1000 AM. WE HAVE POSTED A DENSE FOG ADVISORY.
MOISTURE WILL BECOME DEEPER LATER TODAY WITH A MOIST SOUTHEAST TO
SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH PLUS AN APPROACHING
MID-LEVEL SHORTWAVE TROUGH. THE SHOWER CHANCE SHOULD INCREASE
DURING THE AFTERNOON. THE GUIDANCE CONSENSUS SUPPORTS POPS OF 40
TO 60 PERCENT. WE LEANED TOWARD THE GFS AND ECMWF MOS FOR THE
TEMPERATURE FORECAST. THE NAM MOS MAY BE TOO WARM BECAUSE OF THE
MORNING FOG AND SOME CLOUDINESS CONTINUING FOR MUCH OF THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL CONTINUE TO APPROACH TONIGHT. THE NAM AND GFS
INDICATE DEEP MOISTURE WITH PRECIPITABLE WATER INCREASING TO NEAR
1.8 OF AN INCH. USED THE HIGHER POP GUIDANCE. AN AVERAGE OF THE
GFS AND NAM PLUS SREF MEAN SUPPORTS TOTAL RAINFALL AROUND ONE-
QUARTER OF AN INCH. DESPITE THE HIGH PRECIPITABLE WATER THIS
RELATIVELY LIGHT AMOUNT MAY BE CORRECT BECAUSE OF WEAK LIFT. THERE
MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS. THE NAM INDICATES
A SHOWALTER INDEX AROUND -1 TONIGHT. ITS LOWEST SURFACE-BASED LI
IS AROUND ZERO. THE MODEL TREND HAS BEEN DIMINISHING INSTABILITY.
THE WEAK INSTABILITY APPEARS REASONABLE BECAUSE MOST OF THE
UPPER-LEVEL LIFT SHOULD STAY WELL NORTH OF THE FORECAST AREA.
SHEAR WILL BE STRONG WITH H85 WINDS NEAR 30 KNOTS BUT WITH A LACK
OF SIGNIFICANT INSTABILITY THE THREAT OF SEVERE THUNDERSTORMS IS
LOW. THE NAM AND GFS ARE CONSISTENT SHOWING DRYING BEGINNING BY
MIDDAY MONDAY BEHIND THE FRONT.
BELIEVE THE WARMER TEMPERATURE GUIDANCE IS BETTER TODAY BECAUSE OF
THE WARM AIR MASS AHEAD OF THE FRONT. CLOUDINESS AND MIXING SHOULD
HOLD UP TEMPERATURES TONIGHT. THE TEMPERATURE GUIDANCE IS LIKELY
TOO COOL. WE WILL GET OFF TO A RELATIVELY WARM START MONDAY AND
THE COOLER AIR WILL BE LAGGING BEHIND THE FRONT. IT SHOULD BE
ANOTHER VERY WARM DAY. USED THE WARMER TEMPERATURE GUIDANCE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE MEDIUM-RANGE MODELS ARE IN GOOD AGREEMENT INDICATING DRY
RIDGING DOMINATING TUESDAY THROUGH WEDNESDAY. MOISTURE MAY BEGIN TO
INCREASE THURSDAY WITH AN ONSHORE FLOW AND THE MOISTURE MAY BE
DEEP BY SATURDAY ASSOCIATED WITH A FRONTAL SYSTEM. THE ECMWF WAS
SLOWER WITH THE TIMING OF THE FRONT. AN AVERAGE OF THE
GFS...ECMWF...AND EKD MOS SUPPORTED CHANCE POPS SATURDAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
WEAK WEDGE CONTINUES OVER THE AREA EARLY THIS MORNING. CONDITIONS
DETERIORATING TO IFR/LIFR LEVELS ACROSS MUCH OF THE AREA. MODELS
STILL SUGGESTING IFR/LIFR FOG WILL PERSIST UNTIL AROUND 14Z. COULD
SEE SOME VARIABILITY IN CONDITIONS AMONG THE TAF SITES...WITH
CLOUDS POSSIBLY KEEPING AGS/DNL AT VFR EARLY THIS MORNING. SHOULD
SEE CIG/VSBY IMPROVEMENT TO MVFR OR VFR 15Z-17Z. CHANCE FOR
SHOWERS LATER THIS AFTERNOON WILL INCREASE FOR TONIGHT AS A COLD
FRONT APPROACHES FROM THE WEST. WILL MENTION MVFR CIGS/VSBYS WITH
SHOWERS AFTER 06Z MONDAY...BUT LOWER CONDITIONS MAY BE POSSIBLE
AS THE FRONT GETS CLOSER.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS CAN BE EXPECTED EARLY
MONDAY MORNING AHEAD OF AN APPROACHING COLD FRONT. THE COLD FRONT IS
FORECAST TO CROSS THE AREA BY LATE MONDAY MORNING. BREEZY CONDITIONS
POSSIBLE TUESDAY AND WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016-
018-020>022-025>031-035>038-041.
GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040-
063>065-077.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
521 AM EST SUN NOV 17 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST WILL DIRECT AN
ONSHORE FLOW INTO THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL MOVE THROUGH THE AREA EARLY MONDAY. COLD
HIGH PRESSURE WILL FOLLOW THE FRONT AND DOMINATE THROUGH THE
MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DENSE FOG COVERED MUCH OF THE FORECAST AREA EARLY THIS MORNING.
SHALLOW LOW-LEVEL MOISTURE AND LIGHT WIND HELPED CAUSE THE FOG.
BASED ON THE HRRR GUIDANCE EXPECT IMPROVING VISIBILITIES BEGINNING
AROUND 1000 AM. WE HAVE POSTED A DENSE FOG ADVISORY.
MOISTURE WILL BECOME DEEPER LATER TODAY WITH A MOIST SOUTHEAST TO
SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH PLUS AN APPROACHING
MID-LEVEL SHORTWAVE TROUGH. THE SHOWER CHANCE SHOULD INCREASE
DURING THE AFTERNOON. THE GUIDANCE CONSENSUS SUPPORTS POPS OF 40
TO 60 PERCENT. WE LEANED TOWARD THE GFS AND ECMWF MOS FOR THE
TEMPERATURE FORECAST. THE NAM MOS MAY BE TOO WARM BECAUSE OF THE
MORNING FOG AND SOME CLOUDINESS CONTINUING FOR MUCH OF THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL CONTINUE TO APPROACH TONIGHT. THE NAM AND GFS
INDICATE DEEP MOISTURE WITH PRECIPITABLE WATER INCREASING TO NEAR
1.8 OF AN INCH. USED THE HIGHER POP GUIDANCE. AN AVERAGE OF THE
GFS AND NAM PLUS SREF MEAN SUPPORTS TOTAL RAINFALL AROUND ONE-
QUARTER OF AN INCH. DESPITE THE HIGH PRECIPITABLE WATER THIS
RELATIVELY LIGHT AMOUNT MAY BE CORRECT BECAUSE OF WEAK LIFT. THERE
MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS. THE NAM INDICATES
A SHOWALTER INDEX AROUND -1 TONIGHT. ITS LOWEST SURFACE-BASED LI
IS AROUND ZERO. THE MODEL TREND HAS BEEN DIMINISHING INSTABILITY.
THE WEAK INSTABILITY APPEARS REASONABLE BECAUSE MOST OF THE
UPPER-LEVEL LIFT SHOULD STAY WELL NORTH OF THE FORECAST AREA.
SHEAR WILL BE STRONG WITH H85 WINDS NEAR 30 KNOTS BUT WITH A LACK
OF SIGNIFICANT INSTABILITY THE THREAT OF SEVERE THUNDERSTORMS IS
LOW. THE NAM AND GFS ARE CONSISTENT SHOWING DRYING BEGINNING BY
MIDDAY MONDAY BEHIND THE FRONT.
BELIEVE THE WARMER TEMPERATURE GUIDANCE IS BETTER TODAY BECAUSE OF
THE WARM AIR MASS AHEAD OF THE FRONT. CLOUDINESS AND MIXING SHOULD
HOLD UP TEMPERATURES TONIGHT. THE TEMPERATURE GUIDANCE IS LIKELY
TOO COOL. WE WILL GET OFF TO A RELATIVELY WARM START MONDAY AND
THE COOLER AIR WILL BE LAGGING BEHIND THE FRONT. IT SHOULD BE
ANOTHER VERY WARM DAY. USED THE WARMER TEMPERATURE GUIDANCE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE MEDIUM-RANGE MODELS ARE IN GOOD AGREEMENT INDICATING DRY
RIDGING DOMINATING TUESDAY THROUGH WEDNESDAY. MOISTURE MAY BEGIN TO
INCREASE THURSDAY WITH AN ONSHORE FLOW AND THE MOISTURE MAY BE
DEEP BY SATURDAY ASSOCIATED WITH A FRONTAL SYSTEM. THE ECMWF WAS
SLOWER WITH THE TIMING OF THE FRONT. AN AVERAGE OF THE
GFS...ECMWF...AND EKD MOS SUPPORTED CHANCE POPS SATURDAY.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/... WEAK WEDGE CONTINUES
OVER THE AREA EARLY THIS MORNING. CONDITIONS DETERIORATING TO
IFR/LIFR LEVELS ACROSS MUCH OF THE AREA. MODELS STILL SUGGESTING
IFR/LIFR FOG WILL PERSIST UNTIL AROUND 14Z. COULD BE SOME
VARIABILITY IN CONDITIONS AMONG THE TAF SITES...WITH CLOUDS
POSSIBLY KEEPING AGS/DNL AT VFR EARLY THIS MORNING. WATER VAPOR
SATELLITE IMAGE INDICATING HIGH LEVEL MOISTURE STREAMING ACROSS
THE REGION. SHOULD SEE CIG/VSBY IMPROVEMENT TO MVFR OR VFR 15Z-
17Z. CHANCE FOR SHOWERS LATER THIS AFTERNOON WILL INCREASE FOR
TONIGHT AS A COLD FRONT APPROACHES FROM THE WEST.
EXTENDED AVIATION OUTLOOK...MODERATE TO HIGH CONFIDENCE IN
RESTRICTIONS LATE SUNDAY NIGHT INTO MONDAY MORNING AHEAD OF AN
APPROACHING COLD FRONT. THE COLD FRONT IS FORECAST TO CROSS THE AREA
MONDAY MORNING. BREEZY CONDITIONS POSSIBLE TUESDAY AND WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016-
018-020>022-025>031-035>038-041.
GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040-
063>065-077.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
514 AM EST SUN NOV 17 2013
.SYNOPSIS...
HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST WILL DIRECT AN
ONSHORE FLOW INTO THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL MOVE THROUGH THE AREA EARLY MONDAY. COLD
HIGH PRESSURE WILL FOLLOW THE FRONT AND DOMINATE THROUGH THE
MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DENSE FOG COVERED MUCH OF THE FORECAST AREA EARLY THIS MORNING.
SHALLOW LOW-LEVEL MOISTURE AND LIGHT WIND HELPED CAUSE THE FOG.
BASED ON THE HRRR GUIDANCE EXPECT IMPROVING VISIBILITIES BEGINNING
AROUND 1000 AM. WE HAVE POSTED A DENSE FOG ADVISORY.
MOISTURE WILL BECOME DEEPER LATER TODAY WITH A MOIST SOUTHEAST TO
SOUTH FLOW ASSOCIATED WITH THE OFFSHORE HIGH PLUS AN APPROACHING
MID-LEVEL SHORTWAVE TROUGH. THE SHOWER CHANCE SHOULD INCREASE
DURING THE AFTERNOON. THE GUIDANCE CONSENSUS SUPPORTS POPS OF 40
TO 60 PERCENT. WE LEANED TOWARD THE GFS AND ECMWF MOS FOR THE
TEMPERATURE FORECAST. THE NAM MOS MAY BE TOO WARM BECAUSE OF THE
MORNING FOG AND SOME CLOUDINESS CONTINUING FOR MUCH OF THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE COLD FRONT WILL CONTINUE TO APPROACH TONIGHT. THE NAM AND GFS
INDICATE DEEP MOISTURE WITH PRECIPITABLE WATER INCREASING TO NEAR
1.8 OF AN INCH. USED THE HIGHER POP GUIDANCE. AN AVERAGE OF THE
GFS AND NAM PLUS SREF MEAN SUPPORTS TOTAL RAINFALL AROUND ONE-
QUARTER OF AN INCH. DESPITE THE HIGH PRECIPITABLE WATER THIS
RELATIVELY LIGHT AMOUNT MAY BE CORRECT BECAUSE OF WEAK LIFT. THERE
MAY BE ENOUGH INSTABILITY FOR THUNDERSTORMS. THE NAM INDICATES
A SHOWALTER INDEX AROUND -1 TONIGHT. ITS LOWEST SURFACE-BASED LI
IS AROUND ZERO. THE MODEL TREND HAS BEEN DIMINISHING INSTABILITY.
THE WEAK INSTABILITY APPEARS REASONABLE BECAUSE MOST OF THE
UPPER-LEVEL LIFT SHOULD STAY WELL NORTH OF THE FORECAST AREA.
SHEAR WILL BE STRONG WITH H85 WINDS NEAR 30 KNOTS BUT WITH A LACK
OF SIGNIFICANT INSTABILITY THE THREAT OF SEVERE THUNDERSTORMS IS
LOW. THE NAM AND GFS ARE CONSISTENT SHOWING DRYING BEGINNING BY
MIDDAY MONDAY BEHIND THE FRONT.
BELIEVE THE WARMER TEMPERATURE GUIDANCE IS BETTER TODAY BECAUSE OF
THE WARM AIR MASS AHEAD OF THE FRONT. CLOUDINESS AND MIXING SHOULD
HOLD UP TEMPERATURES TONIGHT. THE TEMPERATURE GUIDANCE IS LIKELY
TOO COOL. WE WILL GET OFF TO A RELATIVELY WARM START MONDAY AND
THE COOLER AIR WILL BE LAGGING BEHIND THE FRONT. IT SHOULD BE
ANOTHER VERY WARM DAY. USED THE WARMER TEMPERATURE GUIDANCE.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE MEDIUM-RANGE MODELS ARE IN GOOD AGREEMENT INDICATING DRY
RIDGING DOMINATING TUESDAY THROUGH WEDNESDAY. MOISTURE MAY BEGIN TO
INCREASE THURSDAY WITH AN ONSHORE FLOW AND THE MOISTURE MAY BE
DEEP BY SATURDAY ASSOCIATED WITH A FRONTAL SYSTEM. THE ECMWF WAS
SLOWER WITH THE TIMING OF THE FRONT. AN AVERAGE OF THE
GFS...ECMWF...AND EKD MOS SUPPORTED CHANCE POPS SATURDAY.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
WEAK WEDGE CONTINUES OVER THE AREA EARLY THIS MORNING. CONFIDENCE
STILL HIGH FOR LIFR/IFR CONDITIONS AT ALL TERMINALS. SHOULD SEE
CIG/VSBY IMPROVEMENT TO MVFR OR VFR 16Z-18Z. CHANCE FOR SHOWERS
LATER THIS AFTERNOON WILL INCREASE FOR TONIGHT AS A COLD FRONT
APPROACHES FROM THE WEST.
EXTENDED AVIATION OUTLOOK...MODERATE TO HIGH CONFIDENCE IN
RESTRICTIONS SUNDAY NIGHT INTO MONDAY MORNING AHEAD OF AN
APPROACHING COLD FRONT. THE COLD FRONT IS FORECAST TO CROSS
THE AREA MONDAY MORNING. BREEZY CONDITIONS POSSIBLE TUESDAY AND
WEDNESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016-
018-020>022-025>031-035>038-041.
GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040-
063>065-077.
&&
$$
AREA FORECAST DISCUSSION
NWS BOISE ID
842 PM MST MON NOV 18 2013
.DISCUSSION...LIGHT RAIN WAS REPORTED IN BURNS OREGON AND RADAR
ECHOES INDICATE VIRGA OR POSSIBLY LIGHT PRECIPITATION ACROSS
PORTION OF BAKER HARNEY AND MALHEUR COUNTIES IN OREGON TO WESTERN
WASHINGTON COUNTY IDAHO...BUT WEB CAMS IN THOSE AREA ARE SO FAR
SNOW FREE. HIGHS WERE A BIT COOLER THAN EXPECTED DUE TO THE RAPID
INCREASE IN CLOUD COVER TODAY. 8 PM TEMPERATURES IN THE LOWER 30S
WERE COMMON ACROSS THE NORTH FROM THE ELKHORNS TO MCCALL SO HAVE
LOWERED SNOW LEVELS AND MIN TEMPS SLIGHTLY. THIS RESULTED IN 2
INCHES OF SNOW FALL FOR MCCALL TONIGHT /SEE PFMBOI/. THROUGH
WEDNESDAY MORNING THE STORM TOTAL SNOW ACCUMULATION IN THE HIGHER
MOUNTAINS ABOVE 6500 FEET COULD REACH A FOOT. THE TREASURE VALLEY
/GENERALLY VALE TO MOUNTAIN HOME/ WILL SEE ALL RAIN...AROUND ONE
QUARTER OF AN INCH BASIN AVERAGE. REMAINDER OF FORECAST IS ON
TRACK WITH ZONES AND GRID UPDATES ALREADY OUT.
&&
.AVIATION...CEILINGS WILL LOWER THROUGH THE NIGHT. LOCAL IFR
CONDITIONS IN SNOW ACROSS MTNS OF EAST-CENTRAL OREGON AND
WEST-CENTRAL IDAHO TONIGHT THROUGH WEDNESDAY MORNING WITH SNOW AOA
5K FEET MSL. RAIN AND AREAS OF MVFR DEVELOPING IN LOWER VALLEYS
THROUGH TUESDAY AFTERNOON. SURFACE WINDS TO 15 KTS WITH WESTERLY
WINDS ALOFT TO 35 KTS AT 10K FEET MSL. CONDITIONS WILL GRADUALLY
IMPROVE FROM NW TO SE ON WEDNESDAY.
&&
.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH WEDNESDAY...A VIGOROUS AND FAST-
MOVING SERIES OF SYSTEMS IS MOVING EAST TOWARD THE PAC NW. THE
INITIAL WAVE IS SET TO MOVE INTO SE OREGON THIS EVENING AND INTO
SW IDAHO OVERNIGHT. LATEST GUIDANCE FROM THE 18Z NAM IS SLOWING
THE SYSTEM DOWN SIGNIFICANTLY...BUT WILL GO WITH THE OVERWHELMING
AGREEMENT OF THE GFS AND EC...ALONG WITH THE 12Z NAM AND THE
LATEST HRRR RUNS...ON THE PRECIP AREA GETTING THROUGH THE TREASURE
VALLEY BY 12Z. CLOUD COVER WILL BE EXTENSIVE TONIGHT...KEEPING
LOW TEMPS WELL ABOVE NORMAL. THE SECOND MAJOR WAVE IN THE SERIES
WILL MOVE THROUGH TUE NIGHT INTO WED...BRINGING ANOTHER ROUND OF
WIDESPREAD PRECIP. SNOW LEVELS FOR BOTH EVENTS WILL BE TOO HIGH TO
BRING SNOW TO THE VALLEYS...WITH HEIGHTS RANGING FROM 5000 FEET IN
THE NORTH TO 7500 FEET IN THE SOUTH TONIGHT...AND FROM 5500 FEET
IN THE NORTH TO 6500 FEET IN THE SOUTH FOR TUE NIGHT INTO WED
MORNING WHEN THE MAJORITY OF THE PRECIP ASSOCIATED WITH THE SECOND
SYSTEM WILL FALL. HEIGHTS WILL COME DOWN SWIFTLY THROUGH THE DAY
WED...CHANGING THE RAIN TO SNOW IN THE NORTH...BUT BY THAT TIME
MOST OF THE PRECIP WILL HAVE ENDED. TEMPS THROUGH THE SHORT TERM
WILL HAVE MINIMAL DIURNAL RANGE OWING TO CLOUD COVER. CHANGES FROM
THE PREVIOUS FORECAST WERE MINOR.
LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...MOSTLY DRY
CONDITIONS WEDNESDAY NIGHT AND THURSDAY WITH LINGERING SHOWERS
ALONG THE NEVADA BORDER AS A WEATHER SYSTEM EXITS TO THE EAST AND
A RIDGE OF HIGH PRESSURE BUILDS OFF THE WEST COAST. DRY CONDITIONS
WILL CONTINUE OVER THE FORECAST AREA FRIDAY THROUGH MONDAY. AS THE
RIDGE OF HIGH PRESSURE STRENGTHENS OVER THE FORECAST AREA
TEMPERATURE INVERSIONS WILL DEVELOP FRIDAY MORNING AND WILL
PERSIST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. WITH
RESIDUAL MOISTURE FROM THE PRECIPITATION FROM TUESDAY AND
WEDNESDAY COMBINED WITH THE INVERSIONS WILL SEE AREAS OF VALLEY
FOG AND LOW STRATUS. TEMPERATURES WILL AVERAGE NEAR NORMAL BUT
VALLEY LOCATIONS UNDER THE INVERSION WILL LIKELY SEE TEMPERATURES
A FEW DEGREES BELOW NORMAL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...VM
AVIATION.....DG
PREV SHORT TERM...SP
PREV LONG TERM....JA/WH
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1056 AM CST SUN NOV 17 2013
.MESOSCALE DISCUSSION...
1055 AM CST
CONVECTION CONTINUES TO BLOSSOM ACROSS CENTRAL INTO NORTHERN IL
WITH THE CWA FULL ENTRENCHED IN THE UNCAPPED WARM SECTOR.
CONVECTIVE MODE CONTINUES TO BE QUICKLY DEVELOPING CELLS WITH
EMBEDDED ROTATION. WHILE MANY CELLS ARE NOT TRULY DISCRETE THEY
ARE MAINTAINING SUPERCELL CHARACTERISTICS. ANTICIPATED THAT MORE
TRULY DISCRETE CONVECTION WILL DEVELOP IN THE NEXT 1-2 HOURS INTO
THE SOUTHEAST HALF/TWO-THIRDS OF THE FORECAST AREA...WHICH IS
WHERE THE RAP IS CONTINUING TO KEEP 0-1KM SHEAR AT 35-45 KT.
THE POTENTIAL FOR TORNADOES...SOME SIGNIFICANT...LOOKS TO BE
RAPIDLY INCREASING THERE. THE CHICAGO AREA IS INCLUDED IN THIS.
ALREADY SEEING SOME OF THESE DISCRETE CELLS IN THE ILX CWA.
MOVEMENT WILL BE RAPIDLY TO THE NORTHEAST. THE CHICAGO AREA STILL
LOOKS TO BE IMPACTED PRIMARILY BETWEEN 12PM- 3PM. FURTHER NORTH
AND WEST TOWARD ROCKFORD THE SEVERE WEATHER THREAT REMAINS HIGH
EVEN WITH DIMINISHING LOW-LEVEL SHEAR...WITH PRIMARY THREATS WINDS
AND TORNADOES.
MTF
&&
.DISCUSSION...
304 AM CST
HIGH SEVERE WEATHER POTENTIAL ACROSS MUCH OF THE AREA TODAY WITH
TORNADOES AND DAMAGING STRAIGHT LINE WINDS A SIGNIFICANT THREAT.
SYNOPSIS...NEAR TERM FOCUS CONTINUES TO BE SEVERE WEATHER THREAT AS
A MAJOR FALL STORM SYSTEM TAKES SHAPE AND MOVES ACROSS THE REGION.
WATER VAPOR IMAGERY SHOWS A BROAD UPPER TROUGH PIVOTING ACROSS THE
MID SECTION OF THE COUNTRY WITH EVENING UPPER AIR ANALYSIS SHOWING A
150 KT UPPER JET DIGGING DOWN ITS WESTERN FLANK. AT THE SAME TIME A
SUB TROPICAL JET OF AROUND 120 KT IS STRETCHED FROM OKLAHOMA UP THE
OHIO VALLEY. SEVERAL SHORTWAVES ARE EMBEDDED IN THE SOUTHWESTERLY
FLOW AHEAD OF THE TROUGH WI ONE WAVE CROSSING NORTHWEST ILLINOIS
EARLY THIS MORNING AND A HINT OF ANOTHER ACROSS EASTERN KANSAS. AT
THE SURFACE...ONE AREA OF LOW PRESSURE IS STRETCHED FROM NORTHERN
MINNESOTA ACROSS LAKE SUPERIOR WITH ANOTHER LOW MOVING NORTHEAST
FROM CENTRAL KANSAS. SYNOPTICALLY...THE UPPER TROUGH WILL AMPLIFY AS
THE UPPER JET ROUNDS THE BASE WITH IT TAKING ON A NEGATIVE TILT AS
IT PIVOTS ACROSS THE LOCAL AREA THROUGH THE AFTERNOON. THIS WILL
CAUSE THE SURFACE LOW OVER KANSAS TO CONTINUE NORTHEAST REACHING
SOUTHERN WISCONSIN BY EARLY AFTERNOON. THE LOW WILL THEN DEEPEN AS
THE UPPER TROUGH AMPLIFIES AND CATCHES UP WITH IT ACROSS NORTHERN
LAKE MICHIGAN LATE THIS AFTERNOON. A COLD FRONTAL BOUNDARY WILL
CROSS THE AREA DURING THE AFTERNOON.
DETAILS FOR TODAY...CONVECTION CONTINUES TO WORK NORTHWARD ACROSS
THE NORTHWEST HALF OR SO OF THE AREA EARLY THIS MORNING IN
CONJUNCTION WITH THE AFOREMENTIONED SHORTWAVE. THIS WAVE IS
COINCIDENT WITH A TIGHTENING LOW/MID LEVEL BAROCLINIC ZONE/WARM
FRONT THAT IS LIFTING NORTHWARD. STEADY ASCENT WILL CONTINUE OVER
THIS BOUNDARY WHICH WILL PROGRESS NORTHWARD THROUGH DAYBREAK KEEPING
AT LEAST SCATTERED CONVECTIVE DEVELOPMENT POSSIBLE ACROSS THE
NORTHERN CWA BEFORE LIFTING NORTH. HAVE NOT SEEN MUCH IN THE WAY OF
WIND GUSTS WITH THE PRECIP THUS FAR WITH INTENSITY HAVING WANED INTO
THE OVERNIGHT HOURS...BUT SOME PULSEY CORES ARE POSSIBLE WITH SOME
SMALL HAIL. SATELLITE IMAGERY SHOWS A FAIR AMOUNT OF SCT-BKN SKIES
UPSTREAM OF THE AREA WITH A MORE WIDESPREAD AREA OF CLOUDS WORKING
NORTHWARD TO THE WEST OF THE CWA. SUSPECT THAT THERE WILL BE BREAKS
IN THE CLOUDS ACROSS PORTIONS OF THE CWA THIS MORNING.
ATTENTION TURNS TO SEVERE POTENTIAL THROUGH THE REST OF THE DAY AS
THE ABOVE SYNOPTIC EVOLUTION COMMENCES. BOTH DYNAMIC AND
THERMODYNAMIC ASPECTS OF THE SYSTEM ARE IMPRESSIVE AND WILL COME
TOGETHER TO PRODUCE AN OUTBREAK OF SEVERE WEATHER ACROSS THE REGION.
THE MAIN QUESTION FOR THE LOCAL AREA WILL BE THE AMOUNT OF COVERAGE
AS THE SYSTEM WORKS THROUGH INTO THE LATE AFTERNOON. THE WESTERN
UPPER JET WILL ROUND THE BASE OF THE TROUGH AND NOSE INTO THE AREA
FROM THE SOUTHWEST DURING THE LATE MORNING AND EARLY AFTERNOON. THIS
JET WILL ALSO COUPLE WITH THE SUB-TROPICAL JET ALREADY IN PLACE
ACROSS THE OHIO VALLEY. IN ADDITION...A 85-90 KT MID LEVEL SPEED MAX
WILL NOSE IN UNDERNEATH THE UPPER JET DURING THIS TIME AS WELL. THE
COMBINATION OF THESE FEATURES AND THE DEEPENING SURFACE TROUGH WILL
PROVIDE DEEP LAYER SHEAR VALUES OF 55-60 KT ACROSS MUCH OF THE AREA
BY MIDDAY...WITH AN INCREASE TO NEAR 70 KT ACROSS THE SOUTHEASTERN
CWA THIS AFTERNOON...WITH 0-1KM SHEAR VALUES OF AROUND 40 KT.
UNSEASONABLY STRONG INSTABILITY WILL DEVELOP AS DEW POINTS RISE INTO
THE LOWER 60S WITH CAPE VALUES OF AROUND 1000 J/KG. FORECAST
SOUNDINGS SHOW HIGH VALUES OF LOW LEVEL CAPE WITH 150 TO EVEN 200
J/KG IN THE LOWEST 3 KM. ALL OF THIS RESULTS IN IMPRESSIVE VALUES
FOR VARIOUS SEVERE WEATHER PARAMETERS. BASED ON ALL OF THIS EXPECT
THAT STORMS WILL INITIATE BY LATE MORNING OVER OR JUST SOUTHWEST/WEST OF
THE SOUTHWEST CWA AS THE ABOVE SYNOPTIC FEATURES ADVANCE NORTHEAST.
COVERAGE OF STORMS LOOKS TO TAKE OFF EARLY THIS AFTERNOON AS THE
COUPLING OF THE MID/UPPER JETS MAXIMIZES AND CONTINUES THROUGH THE
AFTERNOON. THE SEVERE THREAT WILL MARKEDLY INCREASE AS THIS OCCURS
AS WELL. THE RATE AT WHICH COVERAGE INCREASES IS STILL SOMEWHAT
UNCERTAIN...AT LEAST THROUGH MIDDAY...WITH IT POSSIBLE THAT A FEW
STORMS DEVELOP INITIALLY WITH A MORE RAPID INCREASE HOLDING OFF
UNTIL EARLY AFTERNOON WITH THE ARRIVAL OF BETTER FORCING. THE MYRIAD
OF AVAILABLE CONVECTIVE ALLOWING GUIDANCE RUNS THE GAMUT OF COVERAGE
SCENARIOS. THE LATEST SPC DAY 1 OUTLOOK LINES UP WELL WITH LOCAL
THINKING PLACING THE HIGHEST RISK FROM BASICALLY CHICAGO SOUTH TO
FORD COUNTY AND POINTS EAST. THIS AREA WILL LINE UP WELL WITH THE
BEST FORCING PARAMETERS AND TIMING OF INCREASING COVERAGE THIS
AFTERNOON. THE REMAINDER OF THE CWA TO THE WEST INCLUDING THE
ROCKFORD AREA IS IN A MODERATE RISK AND MAY BE MORE IN LINE WITH THE
INITIAL DEVELOPMENT. AS FAR AS THREATS...THE STRONG SHEAR AND
INSTABILITY WILL POINT TO DISCRETE SUPERCELL DEVELOPMENT WITH AN
EVENTUAL EVOLUTION INTO A SQUALL LINE LATER TODAY. IT IS POSSIBLE
THAT MUCH OF THE ACTIVITY REMAINS FAIRLY DISCRETE ACROSS THE CWA
WITH EVOLUTION INTO A PREDOMINATELY LINEAR STRUCTURE TAKING PLACE
OVER OR JUST EAST OF THE EASTERN CWA. GIVEN THE STRONG LOW LEVEL
SHEAR AND INSTABILITY...TORNADOES ARE A DEFINITE THREAT ALONG WITH
DAMAGING WINDS FOLLOWED BY LARGE HAIL. THE STRONG SHEAR AND
POTENTIAL FOR MAINTENANCE OF DISCRETE CELLS SUGGEST THE POTENTIAL
FOR STRONGER AND LONGER TRACKED TORNADOES SHOULD THEY OCCUR.
THE OTHER HIGHLIGHT IS THE SYNOPTIC NON-THUNDERSTORM WINDS.
SOUTHERLY SPEEDS WILL INCREASE THROUGH THE MORNING...ESPECIALLY IF
ANY MEANINGFUL CLEARING CAN OCCUR AS PRESSURE FALLS INCREASE AHEAD
OF THE LOW. THE BIGGEST CONCERN HOWEVER IS WINDS BEHIND THE COLD
FRONT WHICH WILL CROSS THE AREA LATER THIS AFTERNOON. THE STRONG
GRADIENT AND ASSOCIATED PRESSURE RISES ARE EXPECTED TO ALLOW FOR
STRONG MIXING AND GENERATION OF WIND GUSTS THAT COULD TOP 50 KT
ACROSS MUCH OF THE CWA...ESPECIALLY FROM THE NORTHERN CHICAGO
SUBURBS BACK TOWARDS THE MENDOTA AREA AND POINTS SOUTH. HAVE
UPGRADED THIS PORTION OF THE WIND ADVISORY TO A HIGH WIND WARNING
THIS AFTERNOON STARTING TOWARD MIDDAY...WITH THE HIGHEST
WINDS...OUTSIDE OF STORMS...THIS AFTERNOON.
MDB
TONIGHT THROUGH SATURDAY...
LOW PRESSURE WILL QUICKLY BE LIFTING ACROSS THE NORTHERN LAKES
THIS EVENING AND INTO WESTERN QUEBEC MONDAY MORNING...WHILE STILL
DEEPENING WHILE HIGH PRESSURE STRENGTHENS ACROSS THE PLAINS
TONIGHT AND CONTINUES TO STRENGTHEN AS IT MOVES ACROSS THE OHIO
VALLEY AND SOUTHERN LAKES REGION MONDAY NIGHT. THE STRONGEST
WINDS/GUSTS SHOULD DIMINISH QUICKLY EARLY THIS EVENING BUT IT WILL
REMAIN WINDY THROUGH THE EARLY MORNING HOURS...GRADUALLY
DIMINISHING OVERNIGHT. WRAP AROUND SHOWERS WILL BE POSSIBLE FOR A
FEW HOURS THIS EVENING...MAINLY ACROSS FAR NORTHERN IL...THEN
SHOULD SEE CLEARING SKIES. MUCH COLDER AIR WILL SPREAD ACROSS THE
REGION WITH LOWS IN THE MID/UPPER 30S BUT COMBINED WITH THE GUSTY
WESTERLY WINDS...WIND CHILLS WILL RANGE FROM THE MID 20S TO AROUND
30 RANGE BY MORNING.
MONDAY WILL REMAIN BREEZY WITH HIGHS IN THE LOWER/MID 40S WITH
MAINLY SUNNY SKIES. WINDS SHOULD STEADILY DIMINISH FROM MID
AFTERNOON THROUGH SUNSET AS THE HIGH CONTINUES TO BUILD EAST.
LIGHT WINDS AND GENERALLY CLEAR SKIES SHOULD ALLOW FOR A FAST TEMP
DROP MONDAY EVENING WITH THE USUAL COLD SPOTS PERHAPS AS LOW AS
THE LOWER 20S...BUT WITH WEAK WARM AIR ADVECTION OVERNIGHT...TEMPS
MAY LEVEL OFF AT SOME POINT. SOUTHERLY FLOW RETURNS TUESDAY AND
WITH MOSTLY SUNNY SKIES EXPECTED...HIGHS INTO THE UPPER 40S LOOK
REASONABLE WITH GUIDANCE SUGGESTING LOWER 50S COULD BE REACHED
THUS TEMPS COULD BE SLIGHTLY WARMER.
RETURN MOISTURE COMBINED WITH WEAK WAVES LIFTING ACROSS THE AREA
NOW APPEAR SUFFICIENT TO PRODUCE SOME SHOWERS WEDNESDAY INTO
WEDNESDAY NIGHT. THE MODELS ARE IN MUCH BETTER AGREEMENT WITH
THIS SOLUTION BUT STILL SOME TIMING DIFFERENCES AS THE ECMWF HOLDS
OFF PRECIP UNTIL WEDNESDAY NIGHT FOR MUCH OF THE AREA AND A SLOWER
TIMING COULD MEAN WARMER TEMPS ON WEDNESDAY. A COLD FRONT THEN
SAGS SOUTH INTO THE AREA THURSDAY AHEAD OF ANOTHER VERY STRONG
HIGH BUILDING SOUTH INTO THE NORTHERN PLAINS. AS THE UPPER TROUGH
DIGS ACROSS THE LAKES REGION...ANOTHER WAVE MOVES EAST/NORTHEAST
ACROSS THE SOUTHERN LAKES AND OHIO VALLEY. TIMING OF COLDER AIR
ALONG WITH END TIME OF PRECIP ALL REMAIN UNCERTAIN FROM THIS
DISTANCE. CURRENT TRENDS WOULD SUGGEST A COLD RAIN WITH A BRIEF
MIX BEFORE ENDING. HOWEVER...GIVEN THE DIFFERENCES...ITS DIFFICULT
TO LOWER OR RAISE POPS FOR VARIOUS TIME PERIODS. THUS HAVE CHANCE
POPS FOR THE ENTIRE WEDNESDAY NIGHT THROUGH FRIDAY NIGHT TIME
PERIOD AND THERE WILL LIKELY BE PERIODS OF NO PRECIP DURING THIS
TIME. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SOUTH SOUTHWEST WINDS 20-31 KT INCREASING TO 22-35 KT EARLY
AFTERNOON. THEN SOUTHWEST WINDS 30-50 KT MID AFTERNOON THROUGH
EARLY EVENING. WEST WINDS 20-35 KT OVERNIGHT.
* ISOLATED SHOWERS LATE THIS MORNING. A PERIOD OF STRONG TO SEVERE
THUNDERSTORMS POSSIBLE MID DAY TO MID AFTERNOON.
* MVFR CIGS THROUGH MID AFTERNOON. BRIEFLY IFR CIG/VSBY IN HEAVIER
SHOWERS AND THUNDERSTORMS.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
...HIGH WINDS ESPECIALLY MID AFTERNOON TO EARLY EVENING...
...MDT TO HIGH RISK OF SEVERE STORMS LATE MORNING-MID AFTERNOON...
SYNOPSIS AND THUNDERSTORM THREAT...NOT A GOOD DAY FOR FLYING. LOW
PRESSURE NEAR THE IA/MO BORDER THIS MORNING WILL INTENSIFY AS IT
MOVES INTO SOUTH CENTRAL WISCONSIN BY MIDDAY...WITH A STRONG COLD
FRONT SURGING EAST ACROSS NORTHERN IL. THE LOW WILL THEN RAPIDLY
DEEPEN LATE THIS AFTERNOON AND EARLY THIS EVENING AS IT MOVES
ACROSS NORTHERN LAKE MICHIGAN AND THE COLD FRONT SWEEPS INTO
INDIANA. UNSEASONABLY MILD AND HUMID AIR IS SURGING NORTH AHEAD OF
THE LOW...PRODUCING AREAS OF SHOWERS AND A FEW THUNDERSTORMS THIS
MORNING. AS THE LOW INTENSIFIES AND THE ATMOSPHERE
DESTABILIZES...MORE ORGANIZED THUNDERSTORM CLUSTERS WILL DEVELOP
AHEAD OF THE COLD FRONT OVER CENTRAL ILLINOIS AND MOVE RAPIDLY
NORTHEAST. SOME OF THE STORMS WILL PRODUCE DAMAGING WINDS AND EVEN
TORNADOES. THUNDERSTORMS WILL END WITH THE PASSAGE OF THE STRONG
COLD FRONT.
WINDS...SOUTH WINDS ARE IN A LULL EARLY THIS MORNING BUT WILL
RAMP UP TO 20 TO 30 KTS BY LATE MORNING. BEHIND THE COLD FRONT
VERY STRONG PRESSURE RISES WILL PRODUCED SUSTAINED SOUTHWEST WINDS
25 TO 30 KT WITH GUSTS TO AROUND 50 KT. THE STRONGEST WINDS WILL
BE MID AFTERNOON THROUGH EARLY EVENING. WINDS WILL TURN WEST AND
GRADUALLY DIMINISH OVERNIGHT.
CIG/VSBY...LOOKING AT SURFACE OBS AROUND THE AREA THIS
MORNING...CIGS ARE GENERALLY 1000-2000 FT BUT WILL DROP BRIEFLY TO
IFR ESPECIALLY IN HEAVIER SHOWERS AND THUNDERSTORMS. CIG/VSBY WILL
IMPROVE RAPIDLY AFTER THE COLD FRONTAL PASSAGE THIS EVENING...AND
SKIES WILL CLEAR OVERNIGHT.
ALLSOPP
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM TO HIGH CONFIDENCE IN WIND FORECAST.
* MEDIUM CONFIDENCE IN CIG/VSBY TRENDS.
* MEDIUM HIGH CONFIDENCE IN TIMING OF PERIOD OF STRONG STORMS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR. STRONG WEST WINDS.
TUESDAY...VFR.
WEDNESDAY AND THURSDAY...CHC SHRA. MVFR POSSIBLE.
FRIDAY...CHC RASN. MVFR LIKELY. IFR POSSIBLE.
SATURDAY...VFR.
ALLSOPP
&&
.MARINE...
142 AM CST
...STORM WARNING ISSUED FOR SOUTH 2/3 OF LAKE MI LATE AFTERNOON
AND TONIGHT...
POWERHOUSE STORM WILL INTENSIFY RAPIDLY THIS AFTERNOON AND
TONIGHT AS IT MOVES FROM NORTHERN ILLINOIS TO SOUTHERN ONTARIO.
THERE WILL BE A BIT OF A LULL IN THE WINDS THIS MORNING...AND
WINDS WILL BE JUST BELOW GALE FORCE FOR A BIT BUT WILL MAINTAIN
THE GALE THROUGH MID AFTERNOON. AS THE LOW PRESSURE MOVES ACROSS
THE NORTH END OF THE LAKE THIS AFTERNOON A STRONG COLD FRONT WILL
SWEEP RAPIDLY ACROSS THE LAKE. A LARGE PRESSURE FALL/RISE COUPLET
WILL MOVE ACROSS NORTHERN IL THIS AFTERNOON AND OVER CENTRAL AND
SOUTHERN LAKE MICHIGAN THIS EVENING. EXPECT WINDS TO INTENSIFY
LATE AFTERNOON AND EVENING WITH GUSTS OF 50 TO 60 KTS. NORTH PART
OF THE LAKE MAY SEE SOME NEAR STORM FORCE GUSTS LATE EVENING
THROUGH THE OVERNIGHT HOURS...BUT NOT AS STRONG AS THE SOUTH AND
CENTRAL. SO HAVE MAINTAINED THE GALE FOR THE NORTH. GALES WILL
THEN CONTINUE OVER THE ENTIRE LAKE THROUGH MONDAY AFTERNOON.
FOR THE NEARSHORE...WINDS WILL RAMP UP TO STORM FORCE GUSTS BY
LATE AFTERNOON BUT DROP BACK TO GALES THIS EVENING...SO A SHORTER
PERIOD OF POTENTIAL STORM FORCE WINDS NEARSHORE.
HIGH PRESSURE WILL THEN SETTLE INTO THE AREA FOR MONDAY NIGHT AND
TUESDAY.
ALLSOPP
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH WIND WARNING...ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 8 PM SUNDAY.
WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012 UNTIL 8 PM SUNDAY.
IN...HIGH WIND WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 8
PM SUNDAY.
LM...GALE WARNING...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 2 PM
SUNDAY.
GALE WARNING...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878...4 AM MONDAY TO 3 PM MONDAY.
STORM WARNING...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-
LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878...2 PM SUNDAY TO 4 AM MONDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ563 UNTIL 3 PM MONDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...8 PM
SUNDAY TO 4 AM MONDAY.
STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...2 PM
SUNDAY TO 8 PM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
142 PM EST SUN NOV 17 2013
.UPDATE...
THE LONG TERM DISCUSSION HAS BEEN UPDATED BELOW.
&&
.MESOSCALE UPDATE...
LATEST SURFACE ANALYSIS SHOWS A WARM FRONT THAT
EXTENDS FROM NW INDIANA SSEWD OVER PARKE COUNTY TO NEAR THE
LOUISVILLE AREA. TEMPS IN THE WARM SECTOR ARE INTO THE LOWER 70S.
LOW LEVEL JET IS SWLY WHICH SHOULD PUSH THE WARM FRONT NEWD OVER THE
NEXT TWO HOURS. THIS IS AGREEABLE ANALYZING THE RAP MODEL WHICH
PUTS FAVORABLE INSTABILITY AND SHEAR OVER THE WRN COUNTIES OF
INDIANA BY 19Z. EXPECT STORMS TO DEVELOP OVER WRN SECTIONS OF
INDIANA BY 2PM EST DEVELOPING INTO A DISCRETE LINE AHEAD OF MAIN
COLD FRONT. LOOKS LIKE STORMS WILL SPREAD ACROSS WRN AND CENTRAL
INDIANA BETWEEN 2PM EST AND 7PM EST. EXPECT TORNADOES...LARGE HAIL
AND DAMAGING WINDS TO ACCOMPANY THESE STORMS.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST SUN NOV 17 2013
SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL
INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND
STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND
THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH
THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN
BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH
MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A
COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND.
&&
.NEAR TERM /UPDATE FOR TODAY/...
ISSUED AT 927 AM EST SUN NOV 17 2013
NO SIGNIFICANT CHANGES MADE TO FORECASTS. GUSTS HAVE BEGUN.
INTERMITTENT SUNSHINE WILL ADD TO INSTABILITY. STORM PREDICTION
CENTER HAD EXPANDED HIGH RISK TO NEARLY ALL OF INDIANA BUT NO REAL
CHANGE FOR CENTRAL INDIANA OTHER THAN ADDING EASTERN COUNTIES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 355 AM EST SUN NOV 17 2013
MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA
BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH
FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER
HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER
OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY
BELOW NORMAL TEMPERATURES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 142 PM EST SUN NOV 17 2013
EXTENDED MODELS AND ENSEMBLES IN GOOD AGREEMENT THAT SEPARATE
FRONTAL SYSTEMS AND FAST MOIST PACIFIC FLOW ALOFT ARE EXPECTED TO
RESULT IN NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES AND SHOWER
CHANCES WEDNESDAY NIGHT THROUGH SATURDAY. THEN...HIGH PRESSURE WILL
BUILD IN FROM THE CANADIAN PRAIRIES WHICH SHOULD KEEP THE REMAINDER
OF NEXT WEEKEND DRY WITH BELOW NORMAL TEMPERATURES. REGIONAL
ALLBLEND IS HANDLING THINGS WELL.
&&
.AVIATION /DISCUSSION FOR THE 171800Z TAF ISSUANCE/...
ISSUED AT 1127 AM EST SUN NOV 17 2013
STRONG LOW PRESSURE SYSTEM WAS SPAWNING SUPERCELL THUNDERSTORMS
ACROSS ILLINOIS AND MISSOURI LATE THIS MORNING. ADDITIONAL AFTERNOON
SUPERCELL DEVELOPMENT IS EXPECTED ACROSS CENTRAL INDIANA THIS
AFTERNOON FOLLOWED BY A LINE OF SEVERE STORMS. THE BEST TIMING FOR
THE LINE...WHICH WILL BE JUST AHEAD OF THE FRONT...WILL BE IN THE
LAF AND HUF AREAS AROUND 19Z-21Z AND IND AND BMG AROUND 20-22Z.
CONFIDENCE IS GOOD REGARDING THE TIMING OF THIS SQUALL LINE.
SO...WILL START WITH VCTS AND THEN GO WITH TEMPO THUNDERSTORMS FOR 2
HOURS WITH SEVERE GUSTS TO 50 KNOTS FROM THE SOUTHWEST AS STORM
MOTION IS EXPECTED TO BE SOUTHWEST AT 50 KNOTS OR MORE. SOUTH AND
SOUTHWEST GRADIENT WINDS ALONE SHOULD GUST TO 35 KNOTS OR MORE WITH
SUSTAINED WINDS NEAR 25 KNOTS. MVFR AND POSSIBLY IFR CONDITIONS IN
STORMS WILL IMPROVE TO VFR AS THE FRONT MOVES THROUGH WITH CLEARING
LATE IN THE EVENING. SHOULD ONLY SCATTERED DIURNAL CU TOMORROW AFTER
16Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
MESO UPDATE...DWM
SYNOPSIS...CP
NEAR TERM...TUCEK
SHORT TERM...CP
LONG TERM....MK
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
100 PM EST SUN NOV 17 2013
.UPDATE...
ADDED MESOSCALE DISCUSSION.
&&
.MESOSCALE UPDATE...
LATEST SURFACE ANALYSIS SHOWS A WARM FRONT THAT
EXTENDS FROM NW INDIANA SSEWD OVER PARKE COUNTY TO NEAR THE
LOUISVILLE AREA. TEMPS IN THE WARM SECTOR ARE INTO THE LOWER 70S.
LOW LEVEL JET IS SWLY WHICH SHOULD PUSH THE WARM FRONT NEWD OVER THE
NEXT TWO HOURS. THIS IS AGREEABLE ANALYZING THE RAP MODEL WHICH
PUTS FAVORABLE INSTABILITY AND SHEAR OVER THE WRN COUNTES OF INDIANA
BY 19Z. EXPECT STORMS TO DEVELOP OVER WRN SECTIONS OF INDIANA BY
2PM EST DEVELOPING INTO A DISCRETE LINE AHEAD OF MAIN COLD FRONT.
LOOKS LIKE STORMS WILL SPREAD ACROSS WRN AND CENTRAL INDIANA BETWEEN
2PM EST AND 7PM EST. EXPECT TORNADOES...LARGE HAIL AND DAMAGING
WINDS TO ACCOMPANY THESE STORMS.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST SUN NOV 17 2013
SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL
INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND
STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND
THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH
THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN
BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH
MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A
COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND.
&&
.NEAR TERM /UPDATE FOR TODAY/...
ISSUED AT 927 AM EST SUN NOV 17 2013
NO SIGNIFICANT CHANGES MADE TO FORECASTS. GUSTS HAVE BEGUN.
INTERMITTENT SUNSHINE WILL ADD TO INSTABILITY. STORM PREDICTION
CENTER HAD EXPANDED HIGH RISK TO NEARLY ALL OF INDIANA BUT NO REAL
CHANGE FOR CENTRAL INDIANA OTHER THAN ADDING EASTERN COUNTIES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 355 AM EST SUN NOV 17 2013
MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA
BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH
FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER
HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER
OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY
BELOW NORMAL TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 147 AM EST SUN NOV 17 2013
ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA
ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND
ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER
SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND
CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS
WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL
CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A
WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY.
THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE
REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG
WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND.
&&
.AVIATION /DISCUSSION FOR THE 171800Z TAF ISSUANCE/...
ISSUED AT 1127 AM EST SUN NOV 17 2013
STRONG LOW PRESSURE SYSTEM WAS SPAWNING SUPERCELL THUNDERSTORMS
ACROSS ILLINOIS AND MISSOURI LATE THIS MORNING. ADDITIONAL AFTERNOON
SUPERCELL DEVELOPMENT IS EXPECTED ACROSS CENTRAL INDIANA THIS
AFTERNOON FOLLOWED BY A LINE OF SEVERE STORMS. THE BEST TIMING FOR
THE LINE...WHICH WILL BE JUST AHEAD OF THE FRONT...WILL BE IN THE
LAF AND HUF AREAS AROUND 19Z-21Z AND IND AND BMG AROUND 20-22Z.
CONFIDENCE IS GOOD REGARDING THE TIMING OF THIS SQUALL LINE.
SO...WILL START WITH VCTS AND THEN GO WITH TEMPO THUNDERSTORMS FOR 2
HOURS WITH SEVERE GUSTS TO 50 KNOTS FROM THE SOUTHWEST AS STORM
MOITON IS EXPECTED TO BE SOUTHWEST AT 50 KNOTS OR MORE. SOUTH AND
SOUTHWEST GRADIENT WINDS ALONE SHOULD GUST TO 35 KNOTS OR MORE WITH
SUSTAINED WINDS NEAR 25 KNOTS. MVFR AND POSSIBLY IFR CONDITIONS IN
STORMS WILL IMPROVE TO VFR AS THE FRONT MOVES THROUGH WITH CLEARING
LATE IN THE EVENING. SHOULD ONLY SCATTERED DIURNAL CU TOMORROW AFTER
16Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
MESO UPDATE...DWM
SYNOPSIS...CP
NEAR TERM...TUCEK
SHORT TERM...CP
LONG TERM....PUMA
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
931 AM EST SUN NOV 17 2013
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST SUN NOV 17 2013
SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL
INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND
STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND
THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH
THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN
BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH
MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A
COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND.
&&
.NEAR TERM /UPDATE FOR TODAY/...
ISSUED AT 927 AM EST SUN NOV 17 2013
NO SIGNIFICANT CHANGES MADE TO FORECASTS. GUSTS HAVE BEGUN.
INTERMITTENT SUNSHINE WILL ADD TO INSTABILITY. STORM PREDICTION
CENTER HAD EXPANDED HIGH RISK TO NEARLY ALL OF INDIANA BUT NO REAL
CHANGE FOR CENTRAL INDIANA OTHER THAN ADDING EASTERN COUNTIES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 355 AM EST SUN NOV 17 2013
MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA
BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH
FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER
HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER
OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY
BELOW NORMAL TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 147 AM EST SUN NOV 17 2013
ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA
ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND
ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER
SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND
CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS
WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL
CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A
WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY.
THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE
REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG
WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND.
&&
.AVIATION /DISCUSSION FOR THE 171200Z TAFS/...
ISSUED AT 511 AM EST SUN NOV 17 2013
POOR FLYING CONDITIONS ARE EXPECTED THIS TAF PERIOD AS MVFR TO
IFR CONDITIONS WILL BE EXPECTED FOR THE NEXT 12 HOURS ALONG WITH
GUSTY SOUTH TO SOUTHWEST WINDS.
A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO PUSH ACROSS INDIANA
TODAY. HRRR REFLECTIVITY SHOWS AN EXPECTED BAND OF TSRA TO DEVELOP
AND PUSH ACROSS INDIANA ALONG OR JUST SLIGHTLY AHEAD OF THE COLD
FRONT THIS AFTERNOON. IN THE MEANTIME...RADAR CONTINUES TO SHOW SCT
SHRA ACROSS CENTRAL INDIANA AS WARM AND MOIST AIR ARRIVES IN THE
AREA ON SW WINDS. FORECAST SOUNDINGS SHOW GOOD LOWER LEVEL
MOISTURE THIS MORNING...INDICATING THE MVFR TO IFR CIGS...FOLLOWED
BY STEEP LAPSE RATES ALOFT LATER THIS AFTERNOON AS THE COLD FRONT
APPROACHES AND PASSES. STRONG PRESSURE GRADIENT REMAINS IN PLACE
AS A STRONG LLJ OF 50 KNTS IS EXPECTED TO PASS AHEAD OF THE COLD
FRONT...THUS WILL CONTINUE TO INCLUDE GUSTY WINDS IN THE TAFS.
IN THE WAKE OF THE FRONT...FORECAST SOUNDINGS SHOW STRONG
SUBSIDENCE AND DRYING AND A RETURN TO VFR CONDITIONS BY LATE THIS EVENING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...CP
NEAR TERM...TUCEK
SHORT TERM...CP
LONG TERM....PUMA
AVIATION...JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
930 AM EST SUN NOV 17 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST SUN NOV 17 2013
SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL
INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND
STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND
THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH
THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN
BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH
MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A
COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 355 AM EST SUN NOV 17 2013
THE TRIGGER HAS BEEN PULLED ON THE HIGH RISK WITH CENTRAL INDIANA
BEING UNDER THE GUN FOR SEVERE WEATHER TODAY. SPC HAS PLACED MUCH OF
THE AREA IN A 30 PERCENT HATCHED RISK FOR TORNADOES...MEANING THERE
IS A 30 PERCENT CHANCE OF AN EF2 OR STRONGER TORNADO WITHIN 25 MILES
OF ANY GIVEN POINT. THE SYSTEM IS EXTREMELY DYNAMIC WITH THE UPPER
TROUGH BECOMING NEGATIVELY TILTED AS IT SWINGS OUT OF ITS CURRENT
POSITION OVER THE INTERMOUNTAIN WEST AND INTO THE UPPER MIDWEST BY
0Z. DEW POINTS ACROSS THE AREA ARE ALREADY IN THE UPPER 50S TO
AROUND 60 IN THE SOUTH WITH LOW 60S UPSTREAM. GUIDANCE HIGHS FOR THE
DAY HAVE COME BACK DOWN A BIT GIVEN CLOUD COVER SHOULD BE IN PLACE
FOR THE ENTIRE DAY BUT STILL YIELDS HIGHS ACROSS THE AREA IN THE
UPPER 60S TO LOWER 70S. THUS SURFACE BASED CAPES THE GFS ARE RUNNING
IN THE LOW TO MIDDLE HUNDREDS FOR MIDDAY AND HIGHER IN THE NAM WITH
MIXED LAYER CAPES IN THE LOW HUNDREDS. WHILE THESE INSTABILITY
NUMBERS ARE NOT HIGH...THEY SHOULD BE SUFFICIENT GIVEN SIGNIFICANT
SHEAR WITH LOW LEVEL...MID LEVEL AND UPPER LEVEL JET MAXES GOING
THROUGH LATER TODAY. LONG CURVED HODOGRAPHS AND 0-1 KM HELICITY
VALUES OF 300-500 SHOW THE SIGNIFICANT POTENTIAL FOR SUPERCELL AND
TORNADO FORMATION.
ONE POSSIBLE WRENCH IN TODAY/S EVENT FOR THIS FORECAST AREA IS THE
OVERNIGHT CONVECTION. A BIT OF CONCERN THAT THIS COULD LEAVE A
STABLE RAIN COOLED AIRMASS OVER THE AREA WITH A BOUNDARY ACROSS THE
SOUTHERN FORECAST AREA OR JUST SOUTH OF THERE THAT COULD IN EFFECT
INHIBIT DEVELOPMENT OVER MUCH OF THE FORECAST AREA DURING THE LATE
MORNING/EARLY AFTERNOON...THUS PREVENTING SUPERCELL DEVELOPMENT.
SHOULD THIS OCCUR...GREAT POTENTIAL WILL STILL BE IN PLACE FOR
SIGNIFICANT DAMAGING WINDS AND SPIN UP TORNADOES WITH THE SQUALL
LINE THAT SHOULD FORM AHEAD OF THE COLD FRONT BY LATE
MORNING/EARLY AFTERNOON ACROSS CENTRAL ILLINOIS.
THE RAPID REFRESH BRINGS THE DEVELOPING SQUALL LINE INTO THE
NORTHWEST COUNTIES AROUND 19Z. THIS AGREES WITH SREF TIMING THAT
BRINGS THE HIGHEST OMEGA THROUGH THE CENTRAL FORECAST AREA AROUND
21Z AND SWINGS THE FRONT AND ASSOCIATED UPWARD MOTION EAST OF THE
AREA BY 0Z AND STUCK WITH THIS TIMING FOR HIGHEST POPS.
ON NON-THUNDERSTORM WIND POTENTIAL...THE LOW PRESSURE SYSTEM WILL
DEEPEN SIGNIFICANTLY AS IT TRAVERSES THE UPPER MIDWEST AND THIS
COULD PRODUCE SOME STRONG WINDS JUST AHEAD OF OR MORE LIKELY JUST
BEHIND THE COLD FRONT. THINK THE STRONGEST OF THESE WINDS WILL STAY
NORTH OF THE FORECAST AREA CLOSER TO THE TRACK OF THE LOW AND THE
GREATEST PRESSURE CHANGES...HOWEVER...WIND ADVISORY STRENGTH GUST OF
50 MPH STILL LOOK LIKE A GOOD POSSIBILITY AND THUS CONTINUED WITH
WIND ADVISORY FOR THE AREA. THINK THE NORTHERN COUNTIES COULD FLIRT
WITH HIGH WIND WARNING CRITERIA...BUT AT THIS POINT THINK THEY WILL
STAY IN HIGH END ADVISORY TERRITORY.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 355 AM EST SUN NOV 17 2013
MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA
BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH
FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER
HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER
OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY
BELOW NORMAL TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 147 AM EST SUN NOV 17 2013
ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA
ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND
ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER
SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND
CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS
WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL
CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A
WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY.
THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE
REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG
WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND.
&&
.AVIATION /DISCUSSION FOR THE 171500Z IND TAF UPDATE/...
ISSUED AT 930 AM EST SUN NOV 17 2013
INCREASED WINDS TO 16 KNOTS WITH GUSTS TO 28 KNOTS AS THE
ATMOSPHERIC MIXING HAS BEGUN. ALSO...KEPT MVFR CEILINGS AND VCSH
WITH RADAR SHOWING SCATTERED WEAK SHOWER ACTIVITY IN THE VICINITY.
PREVIOUS DISCUSSION FOLLOWS...
POOR FLYING CONDITIONS ARE EXPECTED THIS TAF PERIOD AS MVFR TO
IFR CONDITIONS WILL BE EXPECTED FOR THE NEXT 12 HOURS ALONG WITH
GUSTY SOUTH TO SOUTHWEST WINDS.
A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO PUSH ACROSS INDIANA
TODAY. HRRR REFLECTIVITY SHOWS AN EXPECTED BAND OF TSRA TO DEVELOP
AND PUSH ACROSS INDIANA ALONG OR JUST SLIGHTLY AHEAD OF THE COLD
FRONT THIS AFTERNOON. IN THE MEANTIME...RADAR CONTINUES TO SHOW SCT
SHRA ACROSS CENTRAL INDIANA AS WARM AND MOIST AIR ARRIVES IN THE
AREA ON SW WINDS. FORECAST SOUNDINGS SHOW GOOD LOWER LEVEL
MOISTURE THIS MORNING...INDICATING THE MVFR TO IFR CIGS...FOLLOWED
BY STEEP LAPSE RATES ALOFT LATER THIS AFTERNOON AS THE COLD FRONT
APPROACHES AND PASSES. STRONG PRESSURE GRADIENT REMAINS IN PLACE
AS A STRONG LLJ OF 50 KNTS IS EXPECTED TO PASS AHEAD OF THE COLD
FRONT...THUS WILL CONTINUE TO INCLUDE GUSTY WINDS IN THE TAFS.
IN THE WAKE OF THE FRONT...FORECAST SOUNDINGS SHOW STRONG SUBSIDENCE
AND DRYING AND A RETURN TO VFR CONDITIONS BY LATE THIS EVENING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 9 PM EST THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....PUMA
AVIATION...JP/MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
523 AM EST SUN NOV 17 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST SUN NOV 17 2013
SEVERE WEATHER IS EXPECTED TODAY WITH MUCH OF CENTRAL
INDIANA BEING IN A HIGH RISK FOR SEVERE WEATHER AS A DYNAMIC AND
STRENGTHENING LOW PRESSURE SYSTEM SWINGS OUT OF THE PLAINS AND
THROUGH THE GREAT LAKES. BY TONIGHT THE COLD FRONT ASSOCIATED WITH
THIS SYSTEM SHOULD BE THROUGH THE AREA AND DRY AIR WILL USHER IN
BEHIND IT. HIGH PRESSURE WILL BUILD IN AND BRING DRY WEATHER THROUGH
MID WEEK. A RAINY PATTERN WILL RETURN FOR THE END OF THE WEEK AND A
COLD FRONT WILL BRING COLD TEMPERATURES IN FOR NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 355 AM EST SUN NOV 17 2013
THE TRIGGER HAS BEEN PULLED ON THE HIGH RISK WITH CENTRAL INDIANA
BEING UNDER THE GUN FOR SEVERE WEATHER TODAY. SPC HAS PLACED MUCH OF
THE AREA IN A 30 PERCENT HATCHED RISK FOR TORNADOES...MEANING THERE
IS A 30 PERCENT CHANCE OF AN EF2 OR STRONGER TORNADO WITHIN 25 MILES
OF ANY GIVEN POINT. THE SYSTEM IS EXTREMELY DYNAMIC WITH THE UPPER TROUGH
BECOMING NEGATIVELY TILTED AS IT SWINGS OUT OF ITS CURRENT POSITION
OVER THE INTERMOUNTAIN WEST AND INTO THE UPPER MIDWEST BY 0Z. DEW
POINTS ACROSS THE AREA ARE ALREADY IN THE UPPER 50S TO AROUND 60 IN
THE SOUTH WITH LOW 60S UPSTREAM. GUIDANCE HIGHS FOR THE DAY HAVE
COME BACK DOWN A BIT GIVEN CLOUD COVER SHOULD BE IN PLACE FOR THE
ENTIRE DAY BUT STILL YIELDS HIGHS ACROSS THE AREA IN THE UPPER 60S
TO LOWER 70S. THUS SURFACE BASED CAPES THE GFS ARE RUNNING IN THE
LOW TO MIDDLE HUNDREDS FOR MIDDAY AND HIGHER IN THE NAM WITH MIXED
LAYER CAPES IN THE LOW HUNDREDS. WHILE THESE INSTABILITY NUMBERS ARE
NOT HIGH...THEY SHOULD BE SUFFICIENT GIVEN SIGNIFICANT SHEAR WITH
LOW LEVEL...MID LEVEL AND UPPER LEVEL JET MAXES GOING THROUGH LATER
TODAY. LONG CURVED HODOGRAPHS AND 0-1 KM HELICITY VALUES OF 300-500
SHOW THE SIGNIFICANT POTENTIAL FOR SUPERCELL AND TORNADO FORMATION.
ONE POSSIBLE WRENCH IN TODAY/S EVENT FOR THIS FORECAST AREA IS THE
OVERNIGHT CONVECTION. A BIT OF CONCERN THAT THIS COULD LEAVE A
STABLE RAIN COOLED AIRMASS OVER THE AREA WITH A BOUNDARY ACROSS THE
SOUTHERN FORECAST AREA OR JUST SOUTH OF THERE THAT COULD IN EFFECT
INHIBIT DEVELOPMENT OVER MUCH OF THE FORECAST AREA DURING THE LATE
MORNING/EARLY AFTERNOON...THUS PREVENTING SUPERCELL DEVELOPMENT.
SHOULD THIS OCCUR...GREAT POTENTIAL WILL STILL BE IN PLACE FOR
SIGNIFICANT DAMAGING WINDS AND SPIN UP TORNADOES WITH THE SQUALL
LINE THAT SHOULD FORM AHEAD OF THE COLD FRONT BY LATE
MORNING/EARLY AFTERNOON ACROSS CENTRAL ILLINOIS.
THE RAPID REFRESH BRINGS THE DEVELOPING SQUALL LINE INTO THE
NORTHWEST COUNTIES AROUND 19Z. THIS AGREES WITH SREF TIMING THAT
BRINGS THE HIGHEST OMEGA THROUGH THE CENTRAL FORECAST AREA AROUND
21Z AND SWINGS THE FRONT AND ASSOCIATED UPWARD MOTION EAST OF THE
AREA BY 0Z AND STUCK WITH THIS TIMING FOR HIGHEST POPS.
ON NON-THUNDERSTORM WIND POTENTIAL...THE LOW PRESSURE SYSTEM WILL
DEEPEN SIGNIFICANTLY AS IT TRAVERSES THE UPPER MIDWEST AND THIS
COULD PRODUCE SOME STRONG WINDS JUST AHEAD OF OR MORE LIKELY JUST
BEHIND THE COLD FRONT. THINK THE STRONGEST OF THESE WINDS WILL STAY
NORTH OF THE FORECAST AREA CLOSER TO THE TRACK OF THE LOW AND THE
GREATEST PRESSURE CHANGES...HOWEVER...WIND ADVISORY STRENGTH GUST OF
50 MPH STILL LOOK LIKE A GOOD POSSIBILITY AND THUS CONTINUED WITH
WIND ADVISORY FOR THE AREA. THINK THE NORTHERN COUNTIES COULD FLIRT
WITH HIGH WIND WARNING CRITERIA...BUT AT THIS POINT THINK THEY WILL
STAY IN HIGH END ADVISORY TERRITORY.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 355 AM EST SUN NOV 17 2013
MODELS SHOW THE COLD FRONT BEING EAST AND SOUTH OF THE FORECAST AREA
BY 0Z TONIGHT...BUT HAVE HELD ONTO POPS IN THE FAR EAST AND SOUTH
FOR THE FIRST FEW HOURS FOR COLLABORATION PURPOSES. BY 3Z HOWEVER
HAVE GONE DRY. AFTER THAT HIGH PRESSURE BUILDS IN FOR THE REMAINDER
OF THE SHORT TERM AND SHOULD SEE MOSTLY CLEAR SKIES AND SLIGHTLY
BELOW NORMAL TEMPERATURES.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 147 AM EST SUN NOV 17 2013
ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA
ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND
ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER
SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND
CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS
WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL
CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A
WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY.
THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE
REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG
WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND.
&&
.AVIATION /DISCUSSION FOR THE 171200Z TAFS/...
ISSUED AT 511 AM EST SUN NOV 17 2013
POOR FLYING CONDITIONS ARE EXPECTED THIS TAF PERIOD AS MVFR TO
IFR CONDITIONS WILL BE EXPECTED FOR THE NEXT 12 HOURS ALONG WITH
GUSTY SOUTH TO SOUTHWEST WINDS.
A STRONG LOW PRESSURE SYSTEM IS EXPECTED TO PUSH ACROSS INDIANA
TODAY. HRRR REFLECTIVITY SHOWS AN EXPECTED BAND OF TSRA TO DEVELOP
AND PUSH ACROSS INDIANA ALONG OR JUST SLIGHTLY AHEAD OF THE COLD
FRONT THIS AFTERNOON. IN THE MEANTIME...RADAR CONTINUES TO SHOW SCT
SHRA ACROSS CENTRAL INDIANA AS WARM AND MOIST AIR ARRIVES IN THE
AREA ON SW WINDS. FORECAST SOUNDINGS SHOW GOOD LOWER LEVEL
MOISTURE THIS MORNING...INDICATING THE MVFR TO IFR CIGS...FOLLOWED
BY STEEP LAPSE RATES ALOFT LATER THIS AFTERNOON AS THE COLD FRONT
APPROACHES AND PASSES. STRONG PRESSURE GRADIENT REMAINS IN PLACE
AS A STRONG LLJ OF 50 KNTS IS EXPECTED TO PASS AHEAD OF THE COLD
FRONT...THUS WILL CONTINUE TO INCLUDE GUSTY WINDS IN THE TAFS.
IN THE WAKE OF THE FRONT...FORECAST SOUNDINGS SHOW STRONG
SUBSIDENCE AND DRYING AND A RETURN TO VFR CONDITIONS BY LATE THIS EVENING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 9 PM EST THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....PUMA
AVIATION...JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
334 AM EST SUN NOV 17 2013
.UPDATE...
AVIATION SECTION UPDATED.
&&
.SYNOPSIS...
ISSUED AT 138 PM EST SAT NOV 16 2013
A POTENT AND STRENGTHENING LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
OVER THE WESTERN GREAT LAKES LATE SUNDAY. AN ASSOCIATED STRONG COLD
FRONT WILL SWEEP EAST ACROSS CENTRAL INDIANA SUNDAY AFTERNOON AND
EVENING. INCREASING MOISTURE STREAMING NORTHWARD AHEAD OF THE FRONT
WILL INTERACT WITH THE FRONT AND RESULT IN WIDESPREAD SHOWERS AND
ALSO THUNDERSTORMS TONIGHT THROUGH SUNDAY EVENING. THERE IS ALSO A
MODERATE RISK OF SEVERE WEATHER SUNDAY AND SUNDAY EVENING WITH
DAMAGING WINDS THE MAIN THREAT ALONG WITH HAIL AND ISOLATED
TORNADOES. HIGH PRESSURE WILL BUILD IN NEXT WEEK WITH DRY CONDITIONS
AND NORMAL TO BELOW NORMAL TEMPERATURES. THE NEXT CHANCE OF SHOWERS
WILL BE LATE IN THE WEEK AND INTO THE WEEKEND AS ANOTHER COLD FRONT
TAKES AIM AT THE OHIO VALLEY.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1007 PM EST SAT NOV 16 2013
RAIN SHOWERS BECOME MORE ORGANIZED AND INCREASING IN COVERAGE
ACROSS THE WESTERN HALF OF THE FORECAST AREA THIS EVENING AS
STRONG LOW LEVEL JET APPROACHES FROM THE WEST. WINDS HAVE STEADILY
INCREASED THROUGH THE EVENING...WITH GUSTS TO 20-25MPH BECOMING
MORE COMMON. TEMPS REMAINED PRIMARILY IN THE UPPER 50S AT 0230Z.
EVENING SURFACE ANALYSIS INDICATING AN OCCLUDING LOW PRESSURE
SYSTEM OVER MINNESOTA WITH A SECONDARY LOW EJECTING INTO THE
CENTRAL PLAINS. A SUBTLE WARM FRONT EXTENDING FROM THE OCCLUDED
LOW ACROSS CENTRAL ILLINOIS AND SOUTHWEST INDIANA WILL LIFT NORTH
ACROSS THE FORECAST AREA OVERNIGHT. BROAD 55-60KT 850MB JET WILL
TRANSPORT DEEP MOISTURE INTO THE REGION TONIGHT...WITH
MESOANALYSIS INDICATING A PLUME OF 1.2-1.4 IN PRECIP WATER VALUES
POISED TO EXPAND ACROSS THE FORECAST AREA WITHIN THE NEXT FEW
HOURS. BOTH THE HRRR AND THE WRF-NMM BOTH CONSISTENT IN EXPANDING
PRECIP OVER CENTRAL INDIANA INTO THE OVERNIGHT...WITH WIDESPREAD
RAIN FROM 06-12Z. COULD SEE LOCALLY HEAVY RAINFALL CONSIDERING THE
HIGH PRECIP WATER VALUES WITH POTENTIAL FOR MANY LOCATIONS TO PICK
UP 0.50 TO 1 INCH OVERNIGHT.
SEEING A SLOW EXPANSION IN LIGHTNING STRIKES OVER THE MID
MISSISSIPPI VALLEY AS WELL AS ELEVATED INSTABILITY INCREASES. WILL
CONTINUE WITH THE ISOLATED THUNDER MENTION OVERNIGHT. SURFACE
BASED CONVECTION SHOULD REMAIN TO THE WEST OF THE WABASH RIVER
THROUGH DAYBREAK. POTENTIAL DOES EXIST LATE TONIGHT FOR A FEW
STRONGER STORMS TO PRODUCE HAIL...ESPECIALLY OVER THE LOWER
WABASH VALLEY...BUT OVERALL ANTICIPATE CONVECTION TO REMAIN
SUBSEVERE THROUGH 12Z.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 138 PM EST SAT NOV 16 2013
OBVIOUS FOCUS FOR THE SHORT TERM WILL BE ON SEVERE WEATHER POTENTIAL
ON SUNDAY AND SUNDAY EVENING AS A CLASSIC FALL SEVERE WEATHER
OUTBREAK LOOKS MORE AND MORE LIKELY WITH DAMAGING WINDS THE MAIN
THREAT...BUT TORNADOES CERTAINLY ARE A CONCERN AS WELL.
MODELS ARE NOW IN GOOD AGREEMENT THAT PACIFIC NORTHWEST TROUGH WILL
BECOME NEGATIVELY TILTED ON SUNDAY CAUSING RAPID INTENSIFICATION OF
A SURFACE LOW PRESSURE SYSTEM. DEEPENING SURFACE LOW WILL LIFT TO
NORTHWEST LOWER MICHIGAN OR THE NORTHERN WATERS OF LAKE MICHIGAN BY
00Z MONDAY. ASSOCIATED COLD FRONT WILL THEN SWEEP QUICKLY EAST
ACROSS CENTRAL INDIANA FROM AROUND 18Z SUNDAY TO 00Z MONDAY. PRIOR
TO THAT...A STALLED COLD FRONT IS EXPECTED TO RETURN NORTH AS A WARM
FRONT ACROSS CENTRAL INDIANA AROUND 12-16Z SUNDAY. UPPER SPEED MAX
TO AROUND 120 KNOTS AROUND THE BASE OF THE TROUGH ALONG WITH
WEAKENING...BUT STILL FORMIDABLE OHIO VALLEY UPPER JET WILL PROVIDE
BROAD DILUENT FLOW ON TOP OF WARM CONVEYOR BELT/60 PLUS KNOT LOW
LEVEL JET AHEAD OF THE COLD FRONT. VERY STRONG WIND SHEAR /40 KNOTS
OR MORE FROM 1000-700 MILLIBARS AND 60 KNOTS OR MORE FROM 1000-500
MILLIBARS/ ALONG WITH LONG CURVED HODOGRAPHS AND VERY HIGH HELICITY
NUMBERS OVER 300 METERS SQUARED PER SECONDS SQUARED WILL PROVIDE
AMPLE SPIN IN THE ATMOSPHERE FOR TORNADIC ACTIVITY GIVEN ENOUGH
INSTABILITY.
REGARDING INSTABILITY...TEMPERATURES IN THE UPPER 60S TO MID 70S
WITH WARM ADVECTION ALONE...DEW POINTS APPROACHING 60
DEGREES...700-500 MILLIBAR LAPSE RATES TO 6 DEGREES CELSIUS PER
KILOMETER OR MORE AND DRY INTRUSION ALOFT SHOULD RESULT IN AT LEAST
SOME SURFACE INSTABILITY DESPITE EXPECTED THICK CLOUD COVER AND
EARLIER OR ONGOING OVERNIGHT AND MORNING CONVECTION. EVEN THE LESS
UNSTABLE...12Z DETERMINISTIC GFS IS NOW FORECASTING 500 J/KG CAPE OR
MORE DURING THE AFTERNOON HOURS BUT WEAKENING SIGNIFICANTLY AFTER
DARK.
BASED ON THE ABOVE...AGREE WITH SPC DAY2 MODERATE RISK AND EXPECT A
SEVERE WEATHER OUTBREAK SUNDAY MORNING THROUGH EARLY SUNDAY EVENING.
WILL HAVE TO WATCH OUT FOR DISCRETE SUPERCELLS ESPECIALLY DURING THE
MORNING NEAR THE SURFACE WARM FRONT AND AFTERNOON IN THE WARM SECTOR
THEN...WITH ELONGATED FRONTOGENESIS OCCURRING NEAR THE COLD
FRONT...SHOULD SEE LINEAR ACTIVITY MOVE THROUGH AROUND 18Z IN THE
NORTHWEST TO 00Z IN THE SOUTHEAST ALONG AND JUST AHEAD OF THE FRONT.
THIS WILL BE MORE OF A WIDESPREAD DAMAGING WIND THREAT BUT WITH ALSO
THE POTENTIAL FOR A FEW BRIEF SPIN UPS IN ANY CIRCULATION COUPLET.
HEAVY RAIN COULD ALSO BE AN ISSUE ESPECIALLY EARLY...BEFORE THE DRY
PUNCH ALOFT MOVES IN. IT WILL ALSO CONTINUE TO BE WINDY...BUT DO NOT
THINK THE HIGHER WINDS AT THE TOP OF THE BOUNDARY LAYER FROM THE
BUFKIT 12Z NAM WILL BE ABLE TO MIX DOWN WITHOUT SUNSHINE.
WILL CONTINUE WITH CATEGORICAL POPS PER MOS AND DROPPING
DRAMATICALLY AFTER 06Z MONDAY AND ALTOGETHER AFTER 06Z. THE REST OF
THE SHORT TERM WILL BE CHARACTERIZED BY DRY WEATHER WITH SLIGHTLY
BELOW NORMAL TEMPERATURES AS CANADIAN HIGH PRESSURE BUILDS IN BEHIND
THE COLD FRONT.
MOS HIGHS IN THE UPPER 40S TO LOWER 50S MONDAY AND ALLBLEND IN THE
40S ON TUESDAY LOOK GOOD. ALSO...SHOULD SEE PLENTY OF SUNSHINE...
ESPECIALLY TUESDAY AS THE HIGH PASSES OVERHEAD.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 147 AM EST SUN NOV 17 2013
ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA
ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND
ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER
SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND
CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS
WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL
CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A
WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY.
THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE
REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG
WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND.
&&
.AVIATION /DISCUSSION FOR THE 170900Z IND TAF UPDATE/...
IFR CONDITIONS ARE EXPECTED TO IMPROVE TO MVFR CIGS OR BETTER AS
THE CURRENT WAVE OF PRECIP OVER EASTERN AND SOUTHERN INDIANA
DEPARTS TO THE EAST. HAVE UPDATED THE TAFS IN THE SHORT TERM TO
REFLECT THESE EXPECTED TRENDS.
/DISCUSSION FOR THE 170600Z TAFS/...
ISSUED AT 1130 PM EST SAT NOV 16 2013
UPPER DISTURBANCE CURRENTLY LIFTING OUT OF NORTHERN MISSOURI WITH
INCREASING RAIN/EMBEDDED CONVECTION ASSOCIATED WITH IT. THIS
DISTURBANCE...COUPLED WITH LIFT ALONG A STRONG LOW LEVEL JET AND A
PLUME OF STEEPER MID LEVEL LAPSE RATES ADVECTING INTO THE
AREA...SUGGEST FAIRLY WIDESPREAD RAIN/EMBEDDED CONVECTION SHOULD
AFFECT THE TAF SITES OVERNIGHT. THIS DISTURBANCE EXPECTED TO
CONTINUE PUSHING OFF TO THE NORTHEAST EARLY SUNDAY...SO
RAIN/CONVECTIVE THREAT SHOULD DIMINISH AROUND SUNRISE OR SHORTLY
AFTER. BRIEF PERIODS OF IFR VISIBILITY RESTRICTIONS EXPECTED WITHIN
THE HEAVIER CELLS.
OTHERWISE...STRONG LOW LEVEL JET OF 55-60 KTS EXPECTED TO MOVE
OVERHEAD OVERNIGHT. STARTING TO SEE WIND GUSTS REACH THE
SURFACE...SO DOUBTFUL THERE IS MUCH OF A CHANCE OF THE NOCTURNAL
INVERSION DEVELOPING. AS A RESULT...DON/T THINK LOW LEVEL WIND SHEAR
WILL REACH CRITERIA.
OUTSIDE OF ANY CONVECTION...EXPECTING CEILINGS GENERALLY AROUND 020
THROUGH MIDDAY ON SUNDAY. SURFACE WIND GUSTS 25-30 KTS FROM 170-190
DEGREES EXPECTED THROUGH THE LATE MORNING...WITH MODELS SUGGEST SOME
GUSTS AROUND 35 KTS TOWARDS MIDDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 9 PM EST THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....PUMA
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
158 AM EST SUN NOV 17 2013
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 138 PM EST SAT NOV 16 2013
A POTENT AND STRENGTHENING LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
OVER THE WESTERN GREAT LAKES LATE SUNDAY. AN ASSOCIATED STRONG COLD
FRONT WILL SWEEP EAST ACROSS CENTRAL INDIANA SUNDAY AFTERNOON AND
EVENING. INCREASING MOISTURE STREAMING NORTHWARD AHEAD OF THE FRONT
WILL INTERACT WITH THE FRONT AND RESULT IN WIDESPREAD SHOWERS AND
ALSO THUNDERSTORMS TONIGHT THROUGH SUNDAY EVENING. THERE IS ALSO A
MODERATE RISK OF SEVERE WEATHER SUNDAY AND SUNDAY EVENING WITH
DAMAGING WINDS THE MAIN THREAT ALONG WITH HAIL AND ISOLATED
TORNADOES. HIGH PRESSURE WILL BUILD IN NEXT WEEK WITH DRY CONDITIONS
AND NORMAL TO BELOW NORMAL TEMPERATURES. THE NEXT CHANCE OF SHOWERS
WILL BE LATE IN THE WEEK AND INTO THE WEEKEND AS ANOTHER COLD FRONT
TAKES AIM AT THE OHIO VALLEY.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1007 PM EST SAT NOV 16 2013
RAIN SHOWERS BECOME MORE ORGANIZED AND INCREASING IN COVERAGE
ACROSS THE WESTERN HALF OF THE FORECAST AREA THIS EVENING AS
STRONG LOW LEVEL JET APPROACHES FROM THE WEST. WINDS HAVE STEADILY
INCREASED THROUGH THE EVENING...WITH GUSTS TO 20-25MPH BECOMING
MORE COMMON. TEMPS REMAINED PRIMARILY IN THE UPPER 50S AT 0230Z.
EVENING SURFACE ANALYSIS INDICATING AN OCCLUDING LOW PRESSURE
SYSTEM OVER MINNESOTA WITH A SECONDARY LOW EJECTING INTO THE
CENTRAL PLAINS. A SUBTLE WARM FRONT EXTENDING FROM THE OCCLUDED
LOW ACROSS CENTRAL ILLINOIS AND SOUTHWEST INDIANA WILL LIFT NORTH
ACROSS THE FORECAST AREA OVERNIGHT. BROAD 55-60KT 850MB JET WILL
TRANSPORT DEEP MOISTURE INTO THE REGION TONIGHT...WITH
MESOANALYSIS INDICATING A PLUME OF 1.2-1.4 IN PRECIP WATER VALUES
POISED TO EXPAND ACROSS THE FORECAST AREA WITHIN THE NEXT FEW
HOURS. BOTH THE HRRR AND THE WRF-NMM BOTH CONSISTENT IN EXPANDING
PRECIP OVER CENTRAL INDIANA INTO THE OVERNIGHT...WITH WIDESPREAD
RAIN FROM 06-12Z. COULD SEE LOCALLY HEAVY RAINFALL CONSIDERING THE
HIGH PRECIP WATER VALUES WITH POTENTIAL FOR MANY LOCATIONS TO PICK
UP 0.50 TO 1 INCH OVERNIGHT.
SEEING A SLOW EXPANSION IN LIGHTNING STRIKES OVER THE MID
MISSISSIPPI VALLEY AS WELL AS ELEVATED INSTABILITY INCREASES. WILL
CONTINUE WITH THE ISOLATED THUNDER MENTION OVERNIGHT. SURFACE
BASED CONVECTION SHOULD REMAIN TO THE WEST OF THE WABASH RIVER
THROUGH DAYBREAK. POTENTIAL DOES EXIST LATE TONIGHT FOR A FEW
STRONGER STORMS TO PRODUCE HAIL...ESPECIALLY OVER THE LOWER
WABASH VALLEY...BUT OVERALL ANTICIPATE CONVECTION TO REMAIN
SUBSEVERE THROUGH 12Z.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 138 PM EST SAT NOV 16 2013
OBVIOUS FOCUS FOR THE SHORT TERM WILL BE ON SEVERE WEATHER POTENTIAL
ON SUNDAY AND SUNDAY EVENING AS A CLASSIC FALL SEVERE WEATHER
OUTBREAK LOOKS MORE AND MORE LIKELY WITH DAMAGING WINDS THE MAIN
THREAT...BUT TORNADOES CERTAINLY ARE A CONCERN AS WELL.
MODELS ARE NOW IN GOOD AGREEMENT THAT PACIFIC NORTHWEST TROUGH WILL
BECOME NEGATIVELY TILTED ON SUNDAY CAUSING RAPID INTENSIFICATION OF
A SURFACE LOW PRESSURE SYSTEM. DEEPENING SURFACE LOW WILL LIFT TO
NORTHWEST LOWER MICHIGAN OR THE NORTHERN WATERS OF LAKE MICHIGAN BY
00Z MONDAY. ASSOCIATED COLD FRONT WILL THEN SWEEP QUICKLY EAST
ACROSS CENTRAL INDIANA FROM AROUND 18Z SUNDAY TO 00Z MONDAY. PRIOR
TO THAT...A STALLED COLD FRONT IS EXPECTED TO RETURN NORTH AS A WARM
FRONT ACROSS CENTRAL INDIANA AROUND 12-16Z SUNDAY. UPPER SPEED MAX
TO AROUND 120 KNOTS AROUND THE BASE OF THE TROUGH ALONG WITH
WEAKENING...BUT STILL FORMIDABLE OHIO VALLEY UPPER JET WILL PROVIDE
BROAD DILUENT FLOW ON TOP OF WARM CONVEYOR BELT/60 PLUS KNOT LOW
LEVEL JET AHEAD OF THE COLD FRONT. VERY STRONG WIND SHEAR /40 KNOTS
OR MORE FROM 1000-700 MILLIBARS AND 60 KNOTS OR MORE FROM 1000-500
MILLIBARS/ ALONG WITH LONG CURVED HODOGRAPHS AND VERY HIGH HELICITY
NUMBERS OVER 300 METERS SQUARED PER SECONDS SQUARED WILL PROVIDE
AMPLE SPIN IN THE ATMOSPHERE FOR TORNADIC ACTIVITY GIVEN ENOUGH
INSTABILITY.
REGARDING INSTABILITY...TEMPERATURES IN THE UPPER 60S TO MID 70S
WITH WARM ADVECTION ALONE...DEW POINTS APPROACHING 60
DEGREES...700-500 MILLIBAR LAPSE RATES TO 6 DEGREES CELSIUS PER
KILOMETER OR MORE AND DRY INTRUSION ALOFT SHOULD RESULT IN AT LEAST
SOME SURFACE INSTABILITY DESPITE EXPECTED THICK CLOUD COVER AND
EARLIER OR ONGOING OVERNIGHT AND MORNING CONVECTION. EVEN THE LESS
UNSTABLE...12Z DETERMINISTIC GFS IS NOW FORECASTING 500 J/KG CAPE OR
MORE DURING THE AFTERNOON HOURS BUT WEAKENING SIGNIFICANTLY AFTER
DARK.
BASED ON THE ABOVE...AGREE WITH SPC DAY2 MODERATE RISK AND EXPECT A
SEVERE WEATHER OUTBREAK SUNDAY MORNING THROUGH EARLY SUNDAY EVENING.
WILL HAVE TO WATCH OUT FOR DISCRETE SUPERCELLS ESPECIALLY DURING THE
MORNING NEAR THE SURFACE WARM FRONT AND AFTERNOON IN THE WARM SECTOR
THEN...WITH ELONGATED FRONTOGENESIS OCCURRING NEAR THE COLD
FRONT...SHOULD SEE LINEAR ACTIVITY MOVE THROUGH AROUND 18Z IN THE
NORTHWEST TO 00Z IN THE SOUTHEAST ALONG AND JUST AHEAD OF THE FRONT.
THIS WILL BE MORE OF A WIDESPREAD DAMAGING WIND THREAT BUT WITH ALSO
THE POTENTIAL FOR A FEW BRIEF SPIN UPS IN ANY CIRCULATION COUPLET.
HEAVY RAIN COULD ALSO BE AN ISSUE ESPECIALLY EARLY...BEFORE THE DRY
PUNCH ALOFT MOVES IN. IT WILL ALSO CONTINUE TO BE WINDY...BUT DO NOT
THINK THE HIGHER WINDS AT THE TOP OF THE BOUNDARY LAYER FROM THE
BUFKIT 12Z NAM WILL BE ABLE TO MIX DOWN WITHOUT SUNSHINE.
WILL CONTINUE WITH CATEGORICAL POPS PER MOS AND DROPPING
DRAMATICALLY AFTER 06Z MONDAY AND ALTOGETHER AFTER 06Z. THE REST OF
THE SHORT TERM WILL BE CHARACTERIZED BY DRY WEATHER WITH SLIGHTLY
BELOW NORMAL TEMPERATURES AS CANADIAN HIGH PRESSURE BUILDS IN BEHIND
THE COLD FRONT.
MOS HIGHS IN THE UPPER 40S TO LOWER 50S MONDAY AND ALLBLEND IN THE
40S ON TUESDAY LOOK GOOD. ALSO...SHOULD SEE PLENTY OF SUNSHINE...
ESPECIALLY TUESDAY AS THE HIGH PASSES OVERHEAD.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 147 AM EST SUN NOV 17 2013
ECMWF AND GFS SHOW DRY WEATHER PERSISTING ACROSS CENTRAL INDIANA
ON WEDNESDAY AS HIGH PRESSURE DEPARTS THE AREA. HOWEVER A WET AND
ACTIVE END TO THE NEXT WORK WEEK LOOKS IN STORE AS SEVERAL WEATHER
SYSTEMS LOOKS TO PUSH ACROSS THE REGION STARTING ON THURSDAY AND
CONTINUING THROUGH SATURDAY. SEVERAL UPPER LEVEL WEATHER SYSTEMS
WITH A MOIST SOUTHWEST FLOW IN PLACE ALOFT WILL PROVIDE SEVERAL
CHANCES AT SHOWERS STARTING ON THURSDAY AND AGAIN ON FRIDAY AS A
WARM FRONTAL BOUNDARY PASSES ACROSS THE OHIO VALLEY.
THE GFS AND ECMWF SHOW A STRONGER COLD FRONT PUSHING ACROSS THE
REGION ON FRIDAY NIGHT...GIVING US ANOTHER SHOT AT PRECIP...ALONG
WITH MUCH COLDER AIR IN THE WAKE OF THE FRONT FOR NEXT WEEKEND.
&&
.AVIATION /DISCUSSION FOR THE 170600Z TAFS/...
ISSUED AT 1130 PM EST SAT NOV 16 2013
UPPER DISTURBANCE CURRENTLY LIFTING OUT OF NORTHERN MISSOURI WITH
INCREASING RAIN/EMBEDDED CONVECTION ASSOCIATED WITH IT. THIS
DISTURBANCE...COUPLED WITH LIFT ALONG A STRONG LOW LEVEL JET AND A
PLUME OF STEEPER MID LEVEL LAPSE RATES ADVECTING INTO THE
AREA...SUGGEST FAIRLY WIDESPREAD RAIN/EMBEDDED CONVECTION SHOULD
AFFECT THE TAF SITES OVERNIGHT. THIS DISTURBANCE EXPECTED TO
CONTINUE PUSHING OFF TO THE NORTHEAST EARLY SUNDAY...SO
RAIN/CONVECTIVE THREAT SHOULD DIMINISH AROUND SUNRISE OR SHORTLY
AFTER. BRIEF PERIODS OF IFR VISIBILITY RESTRICTIONS EXPECTED WITHIN
THE HEAVIER CELLS.
OTHERWISE...STRONG LOW LEVEL JET OF 55-60 KTS EXPECTED TO MOVE
OVERHEAD OVERNIGHT. STARTING TO SEE WIND GUSTS REACH THE
SURFACE...SO DOUBTFUL THERE IS MUCH OF A CHANCE OF THE NOCTURNAL
INVERSION DEVELOPING. AS A RESULT...DON/T THINK LOW LEVEL WIND SHEAR
WILL REACH CRITERIA.
OUTSIDE OF ANY CONVECTION...EXPECTING CEILINGS GENERALLY AROUND 020
THROUGH MIDDAY ON SUNDAY. SURFACE WIND GUSTS 25-30 KTS FROM 170-190
DEGREES EXPECTED THROUGH THE LATE MORNING...WITH MODELS SUGGEST SOME
GUSTS AROUND 35 KTS TOWARDS MIDDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 9 PM EST THIS EVENING FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....PUMA
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1130 PM EST SAT NOV 16 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 138 PM EST SAT NOV 16 2013
A POTENT AND STRENGTHENING LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
OVER THE WESTERN GREAT LAKES LATE SUNDAY. AN ASSOCIATED STRONG COLD
FRONT WILL SWEEP EAST ACROSS CENTRAL INDIANA SUNDAY AFTERNOON AND
EVENING. INCREASING MOISTURE STREAMING NORTHWARD AHEAD OF THE FRONT
WILL INTERACT WITH THE FRONT AND RESULT IN WIDESPREAD SHOWERS AND
ALSO THUNDERSTORMS TONIGHT THROUGH SUNDAY EVENING. THERE IS ALSO A
MODERATE RISK OF SEVERE WEATHER SUNDAY AND SUNDAY EVENING WITH
DAMAGING WINDS THE MAIN THREAT ALONG WITH HAIL AND ISOLATED
TORNADOES. HIGH PRESSURE WILL BUILD IN NEXT WEEK WITH DRY CONDITIONS
AND NORMAL TO BELOW NORMAL TEMPERATURES. THE NEXT CHANCE OF SHOWERS
WILL BE LATE IN THE WEEK AND INTO THE WEEKEND AS ANOTHER COLD FRONT
TAKES AIM AT THE OHIO VALLEY.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 1007 PM EST SAT NOV 16 2013
RAIN SHOWERS BECOME MORE ORGANIZED AND INCREASING IN COVERAGE
ACROSS THE WESTERN HALF OF THE FORECAST AREA THIS EVENING AS
STRONG LOW LEVEL JET APPROACHES FROM THE WEST. WINDS HAVE STEADILY
INCREASED THROUGH THE EVENING...WITH GUSTS TO 20-25MPH BECOMING
MORE COMMON. TEMPS REMAINED PRIMARILY IN THE UPPER 50S AT 0230Z.
EVENING SURFACE ANALYSIS INDICATING AN OCCLUDING LOW PRESSURE
SYSTEM OVER MINNESOTA WITH A SECONDARY LOW EJECTING INTO THE
CENTRAL PLAINS. A SUBTLE WARM FRONT EXTENDING FROM THE OCCLUDED
LOW ACROSS CENTRAL ILLINOIS AND SOUTHWEST INDIANA WILL LIFT NORTH
ACROSS THE FORECAST AREA OVERNIGHT. BROAD 55-60KT 850MB JET WILL
TRANSPORT DEEP MOISTURE INTO THE REGION TONIGHT...WITH
MESOANALYSIS INDICATING A PLUME OF 1.2-1.4 IN PRECIP WATER VALUES
POISED TO EXPAND ACROSS THE FORECAST AREA WITHIN THE NEXT FEW
HOURS. BOTH THE HRRR AND THE WRF-NMM BOTH CONSISTENT IN EXPANDING
PRECIP OVER CENTRAL INDIANA INTO THE OVERNIGHT...WITH WIDESPREAD
RAIN FROM 06-12Z. COULD SEE LOCALLY HEAVY RAINFALL CONSIDERING THE
HIGH PRECIP WATER VALUES WITH POTENTIAL FOR MANY LOCATIONS TO PICK
UP 0.50 TO 1 INCH OVERNIGHT.
SEEING A SLOW EXPANSION IN LIGHTNING STRIKES OVER THE MID
MISSISSIPPI VALLEY AS WELL AS ELEVATED INSTABILITY INCREASES. WILL
CONTINUE WITH THE ISOLATED THUNDER MENTION OVERNIGHT. SURFACE
BASED CONVECTION SHOULD REMAIN TO THE WEST OF THE WABASH RIVER
THROUGH DAYBREAK. POTENTIAL DOES EXIST LATE TONIGHT FOR A FEW
STRONGER STORMS TO PRODUCE HAIL...ESPECIALLY OVER THE LOWER
WABASH VALLEY...BUT OVERALL ANTICIPATE CONVECTION TO REMAIN
SUBSEVERE THROUGH 12Z.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
ISSUED AT 138 PM EST SAT NOV 16 2013
OBVIOUS FOCUS FOR THE SHORT TERM WILL BE ON SEVERE WEATHER POTENTIAL
ON SUNDAY AND SUNDAY EVENING AS A CLASSIC FALL SEVERE WEATHER
OUTBREAK LOOKS MORE AND MORE LIKELY WITH DAMAGING WINDS THE MAIN
THREAT...BUT TORNADOES CERTAINLY ARE A CONCERN AS WELL.
MODELS ARE NOW IN GOOD AGREEMENT THAT PACIFIC NORTHWEST TROUGH WILL
BECOME NEGATIVELY TILTED ON SUNDAY CAUSING RAPID INTENSIFICATION OF
A SURFACE LOW PRESSURE SYSTEM. DEEPENING SURFACE LOW WILL LIFT TO
NORTHWEST LOWER MICHIGAN OR THE NORTHERN WATERS OF LAKE MICHIGAN BY
00Z MONDAY. ASSOCIATED COLD FRONT WILL THEN SWEEP QUICKLY EAST
ACROSS CENTRAL INDIANA FROM AROUND 18Z SUNDAY TO 00Z MONDAY. PRIOR
TO THAT...A STALLED COLD FRONT IS EXPECTED TO RETURN NORTH AS A WARM
FRONT ACROSS CENTRAL INDIANA AROUND 12-16Z SUNDAY. UPPER SPEED MAX
TO AROUND 120 KNOTS AROUND THE BASE OF THE TROUGH ALONG WITH
WEAKENING...BUT STILL FORMIDABLE OHIO VALLEY UPPER JET WILL PROVIDE
BROAD DILUENT FLOW ON TOP OF WARM CONVEYOR BELT/60 PLUS KNOT LOW
LEVEL JET AHEAD OF THE COLD FRONT. VERY STRONG WIND SHEAR /40 KNOTS
OR MORE FROM 1000-700 MILLIBARS AND 60 KNOTS OR MORE FROM 1000-500
MILLIBARS/ ALONG WITH LONG CURVED HODOGRAPHS AND VERY HIGH HELICITY
NUMBERS OVER 300 METERS SQUARED PER SECONDS SQUARED WILL PROVIDE
AMPLE SPIN IN THE ATMOSPHERE FOR TORNADIC ACTIVITY GIVEN ENOUGH
INSTABILITY.
REGARDING INSTABILITY...TEMPERATURES IN THE UPPER 60S TO MID 70S
WITH WARM ADVECTION ALONE...DEW POINTS APPROACHING 60
DEGREES...700-500 MILLIBAR LAPSE RATES TO 6 DEGREES CELSIUS PER
KILOMETER OR MORE AND DRY INTRUSION ALOFT SHOULD RESULT IN AT LEAST
SOME SURFACE INSTABILITY DESPITE EXPECTED THICK CLOUD COVER AND
EARLIER OR ONGOING OVERNIGHT AND MORNING CONVECTION. EVEN THE LESS
UNSTABLE...12Z DETERMINISTIC GFS IS NOW FORECASTING 500 J/KG CAPE OR
MORE DURING THE AFTERNOON HOURS BUT WEAKENING SIGNIFICANTLY AFTER
DARK.
BASED ON THE ABOVE...AGREE WITH SPC DAY2 MODERATE RISK AND EXPECT A
SEVERE WEATHER OUTBREAK SUNDAY MORNING THROUGH EARLY SUNDAY EVENING.
WILL HAVE TO WATCH OUT FOR DISCRETE SUPERCELLS ESPECIALLY DURING THE
MORNING NEAR THE SURFACE WARM FRONT AND AFTERNOON IN THE WARM SECTOR
THEN...WITH ELONGATED FRONTOGENESIS OCCURRING NEAR THE COLD
FRONT...SHOULD SEE LINEAR ACTIVITY MOVE THROUGH AROUND 18Z IN THE
NORTHWEST TO 00Z IN THE SOUTHEAST ALONG AND JUST AHEAD OF THE FRONT.
THIS WILL BE MORE OF A WIDESPREAD DAMAGING WIND THREAT BUT WITH ALSO
THE POTENTIAL FOR A FEW BRIEF SPIN UPS IN ANY CIRCULATION COUPLET.
HEAVY RAIN COULD ALSO BE AN ISSUE ESPECIALLY EARLY...BEFORE THE DRY
PUNCH ALOFT MOVES IN. IT WILL ALSO CONTINUE TO BE WINDY...BUT DO NOT
THINK THE HIGHER WINDS AT THE TOP OF THE BOUNDARY LAYER FROM THE
BUFKIT 12Z NAM WILL BE ABLE TO MIX DOWN WITHOUT SUNSHINE.
WILL CONTINUE WITH CATEGORICAL POPS PER MOS AND DROPPING
DRAMATICALLY AFTER 06Z MONDAY AND ALTOGETHER AFTER 06Z. THE REST OF
THE SHORT TERM WILL BE CHARACTERIZED BY DRY WEATHER WITH SLIGHTLY
BELOW NORMAL TEMPERATURES AS CANADIAN HIGH PRESSURE BUILDS IN BEHIND
THE COLD FRONT.
MOS HIGHS IN THE UPPER 40S TO LOWER 50S MONDAY AND ALLBLEND IN THE
40S ON TUESDAY LOOK GOOD. ALSO...SHOULD SEE PLENTY OF SUNSHINE...
ESPECIALLY TUESDAY AS THE HIGH PASSES OVERHEAD.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 219 PM EST SAT NOV 16 2013
MODELS CONTINUE TO HOLD ONTO HIGH PRESSURE EARLY IN THE LONG TERM
PERIOD...WITH A TREND TOWARD WETTER FORECASTS LATE IN THE WEEK AND
INTO THE WEEKEND. INITIALIZATION PROVIDED SLIGHT CHANCE TO LOW
CHANCE POPS FROM WEDNESDAY NIGHT ONWARD...AND CANNOT REALLY ARGUE
WITH IT...ALTHOUGH THE LENGTH OF TIME POPS ARE IN MAY BE A BIT
OVERDONE. THIS WILL BE REFINED AS THE WEEK WEARS ON.
QUASIZONAL FLOW MUCH OF THE PERIOD SUGGESTS TEMPS NEAR
CLIMATOLOGY...AND INITIALIZATION HANDLED THIS WELL.
&&
.AVIATION /DISCUSSION FOR THE 170600Z TAFS/...
ISSUED AT 1130 PM EST SAT NOV 16 2013
UPPER DISTURBANCE CURRENTLY LIFTING OUT OF NORTHERN MISSOURI WITH
INCREASING RAIN/EMBEDDED CONVECTION ASSOCIATED WITH IT. THIS
DISTURBANCE...COUPLED WITH LIFT ALONG A STRONG LOW LEVEL JET AND A
PLUME OF STEEPER MID LEVEL LAPSE RATES ADVECTING INTO THE
AREA...SUGGEST FAIRLY WIDESPREAD RAIN/EMBEDDED CONVECTION SHOULD
AFFECT THE TAF SITES OVERNIGHT. THIS DISTURBANCE EXPECTED TO
CONTINUE PUSHING OFF TO THE NORTHEAST EARLY SUNDAY...SO
RAIN/CONVECTIVE THREAT SHOULD DIMINISH AROUND SUNRISE OR SHORTLY
AFTER. BRIEF PERIODS OF IFR VISIBILITY RESTRICTIONS EXPECTED WITHIN
THE HEAVIER CELLS.
OTHERWISE...STRONG LOW LEVEL JET OF 55-60 KTS EXPECTED TO MOVE
OVERHEAD OVERNIGHT. STARTING TO SEE WIND GUSTS REACH THE
SURFACE...SO DOUBTFUL THERE IS MUCH OF A CHANCE OF THE NOCTURNAL
INVERSION DEVELOPING. AS A RESULT...DON/T THINK LOW LEVEL WIND SHEAR
WILL REACH CRITERIA.
OUTSIDE OF ANY CONVECTION...EXPECTING CEILINGS GENERALLY AROUND 020
THROUGH MIDDAY ON SUNDAY. SURFACE WIND GUSTS 25-30 KTS FROM 170-190
DEGREES EXPECTED THROUGH THE LATE MORNING...WITH MODELS SUGGEST SOME
GUSTS AROUND 35 KTS TOWARDS MIDDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TO 9 PM EST SUNDAY FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....NIELD
AVIATION...JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS WICHITA KS
1242 PM CST SUN NOV 17 2013
.UPDATE...
ISSUED AT 1226 PM CST SUN NOV 17 2013
HOISTED HIGH WIND WARNING ACROSS NORTHERN PORTION OF CWA. SURFACE
OBSERVATIONS UPSTREAM CONTINUING TO DETECT WIND GUSTS FLIRTING OR
EXCEEDING 50KTS. BOTH HRRR AND RUC DEPICTING NARROW CORRIDOR OF
50KT OR GREATER WINDS AFFECTING RUSSELL AND LINCOLN
COUNTIES...WITH 0.5 PV FOLD TRAVERSING THE REGION BETWEEN
18-21UTC...WHICH SHOULD ENHANCE MOMENTUM TRANSPORT. HWW THREAT
WILL BE ON THE LOW END ACROSS ELLSWORTH AND SALINE
COUNTIES...HOWEVER GIVEN I-70 RUNS THROUGH THESE AREAS...FELT
INCLUDING THEM WOULD BE PRUDENT GIVEN POTENTIAL IMPACT TO TRAFFIC.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 257 AM CST SUN NOV 17 2013
CURRENT SATELLITE WATER VAPOR IMAGERY SHOWS A VIGOROUS UPPER WAVE
OVER COLORADO WHICH WILL SWEEP EASTWARD ACROSS THE CENTRAL PLAINS
TODAY. DEEP ADIABATIC MIXING/STRONG DOWNWARD MOMENTUM TRANSFER
BEHIND THE COLD FRONT WILL CAUSE VERY STRONG NORTHWEST WINDS TO
SPREAD ACROSS MUCH OF THE AREA TODAY...THUS WILL EXPAND THE WIND
ADVISORY INTO SOUTHEAST KANSAS FOR THIS AFTERNOON. ITS POSSIBLE THAT
SOME LOCATIONS IN CENTRAL KANSAS AROUND I-70 CORRIDOR COULD GET
VERY CLOSE TO HIGH WIND WARNING LEVELS. OTHERWISE THE WINDS SHOULD
DIMINISH RAPIDLY AROUND SUNSET AS THE BOUNDARY LAYER COOLS AND
STABILIZES. SURFACE HIGH PRESSURE WILL BUILD OVER THE REGION ON
MONDAY THEN SLIDE EAST OF KANSAS ON TUESDAY...WITH NEAR NORMAL
TEMPERATURES AND DRY WEATHER EXPECTED.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 257 AM CST SUN NOV 17 2013
THE MODEL DIFFERENCES CONTINUE BETWEEN THE GFS/ECMWF MODELS ON THE
HANDLING/TIMING OF THE COLD AIR AND RESULTANT AFFECTS ON
PRECIPITATION TYPE FOR THURSDAY INTO SATURDAY...HOWEVER THE
SYNOPTIC PATTERN BY BOTH MODELS STILL SUGGESTS THAT THE COLD DENSE
AIR COULD WIN OUT AND SURGE SOUTHWARD FOR LATE NEXT WEEK. WE WILL
TREND TEMPERATURES DOWN AND CHANGE PRECIP TYPE OVER TO WINTER
TYPE PRECIP SOONER. DEFINITELY A PERIOD TO KEEP AN EYE ON WITH
LATER FORECAST UPDATES...SINCE ACCUMULATING SNOW COULD MATERIALIZE
FOR KANSAS.
JAKUB
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1226 PM CST SUN NOV 17 2013
WIND WILL BE THE MAIN AVIATION IMPACT THIS AFTERNOON. DEEP MIXING
WILL RESULT IN SUSTAINED WINDS IN THE 30-35KT RANGE WITH GUSTS
35-45KTS AT KICT...KHUT AND KCNU DURING THE AFTERNOON. STRONGER
WINDS EXPECTED AT KRSL AND KSLN...WHERE SUSTAINED WINDS WILL
AVERAGE 40KTS WITH GUSTS 50KTS. WINDS WILL SUBSIDE AROUND SUNSET
AS MIXING DIMINISHES.
VFR SKIES AND VISIBILITY EXPECTED THROUGHOUT THE TAF PERIOD.
SF
&&
.FIRE WEATHER...
ISSUED AT 257 AM CST SUN NOV 17 2013
THE COMBINATION OF VERY STRONG NORTHWEST WINDS AND MUCH DRIER AIR
SPREADING SOUTHWARD WILL CREATE CRITICAL GRASSLAND FIRE DANGER
LEVELS ACROSS CENTRAL KANSAS...AND A GOOD PORTION OF SOUTH CENTRAL
KANSAS TODAY. A RED FLAG WARNING REMAINS IN EFFECT FOR TODAY AND
IF ANY FIRES WERE TO DEVELOP THEY WOULD BECOME NEARLY IMPOSSIBLE
TO CONTROL.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 31 58 34 60 / 0 0 0 0
HUTCHINSON 29 58 33 60 / 0 0 0 0
NEWTON 30 57 34 60 / 0 0 0 0
ELDORADO 32 58 34 59 / 0 0 0 0
WINFIELD-KWLD 32 59 35 61 / 0 0 0 0
RUSSELL 25 58 33 60 / 0 0 0 0
GREAT BEND 26 58 33 61 / 0 0 0 0
SALINA 28 58 33 60 / 0 0 0 0
MCPHERSON 29 58 33 60 / 0 0 0 0
COFFEYVILLE 34 59 34 61 / 0 0 0 10
CHANUTE 33 58 33 59 / 0 0 0 10
IOLA 33 57 33 59 / 0 0 0 10
PARSONS-KPPF 33 58 33 60 / 0 0 0 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ032-033-
047>053-067>069-082-083.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ047-050>053-
067>072-082-083-094>096.
HIGH WIND WARNING UNTIL 3 PM CST THIS AFTERNOON FOR KSZ032-033-
048-049.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ032-033-048-049.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1215 PM CST Sun Nov 17 2013
.UPDATE...
Issued at 1151 AM CST SUN NOV 17 2013
The latest runs of the RAP and HRRR have been highlighting the
potential for wind gusts around 50 kt for areas south and west of
a line from Concordia to Topeka to Emporia. The forecast soundings
show strong sinking motion in the low levels which may enhance the
downward momentum transfer of winds to the surface. The low level
jet is forecast to increase through the early afternoon hours
directly over the area. There has already been gusts up to 53 mph
in north central KS. These wind gusts will likely begin now around
central KS and work eastward into east central KS during the early
afternoon hours. Therefore have upgraded the wind advisory to a
high wind warning. There is also the possibility that the red
flag warning may need to be expanded eastward very soon given this
deeper mixing in the boundary layer resulting in lower dew points.
&&
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 335 AM CST SUN NOV 17 2013
Latest surface analysis at 08Z had a surface low over north central
Kansas along a stationary front that extended from Iowa back into
southeast Colorado. Satellite imagery this morning shows the
shortwave trough moving out of the Rockies.
The surface low pressure is forecast to move off to the east as the
upper wave moves through the Central Plains with an increasing
pressure gradient behind the cold front moving across northeast
Kansas. This will bring strong winds of 25 to 30 mph with gusts to
around 45 mph possible from mid morning through late afternoon as
forecast soundings show deep mixing today with steep low level lapse
rates. These stronger winds will affect the entire forecast area and
sustained winds around 30 mph will be common so will go with a wind
advisory today from 10 am to 5 pm. The deep mixing will also mix
down drier air and as a result minimum afternoon humidity of 20
percent or less is expected across parts of north central Kansas.
The low relative humidity and critical fuels will produce very high
to extreme fire danger and will continue with the Red Flag Warning
for parts of north central Kansas today.
Tonight the winds will be on the decrease through the early evening
hours as the lower boundary layer decouples and broad surface high
pressure builds into central and eastern Kansas. Lows tonight will
fall into the middle 20s in north central to the mid 30s in east
central Kansas.
.LONG TERM...(Monday through Saturday)
Issued at 335 AM CST SUN NOV 17 2013
Early week periods starting fairly quiet, but southerly winds under
zonal flow aloft will bring moisture back rather quickly. Models are
trending faster with a shortwave zipping though the flow, with
moderate upper level potential vorticity advection and mid-level
isentropic lift combining for elevated precipitation possibilities
as early as Tuesday evening. Increasing lapse rates and PW values
again well above normal support some mention of thunder as well.
The faster timing should keep mixing up for a warmer night as well
as a quicker drying trend for Wednesday.
The medium range models are in agreement with increasingly amplified
split flow setting up for the late week periods, but much is left be
desired in agreement in the details and a low confidence forecast
continues. One issue is how fast the cold air will surge in behind a
northern branch wave and another is the character and speed of
southern branch upper energy. At this point have the highest PoPs
Thursday night and Friday with temps steadily cooling with column
temps increasingly supporting snow inclusion with time. There is
decent agreement with a secondary cold surge pushing precip chances
to the south by the weekend.
&&
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1151 AM CST SUN NOV 17 2013
Have increased the wind speeds at all the taf sites due to the
latest guidance suggesting higher winds moving across the area
early this afternoon. The winds should diminish in the late
afternoon and early evening especially after sunset.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 5 PM CST this afternoon FOR KSZ008>012-024-
026-040-056-058-059.
HIGH WIND WARNING until 3 PM CST this afternoon FOR KSZ020>023-
034>039-054-055.
RED FLAG WARNING until 6 PM CST this evening FOR KSZ008-020>022-
034>037.
&&
$$
UPDATE...Sanders
SHORT TERM...53
LONG TERM...65
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS PADUCAH KY
549 AM CST Sun Nov 17 2013
.SHORT TERM...(Today and Tonight)
ISSUED AT 423 AM CST SUN NOV 17 2013
Will have to monitor the embedded linear segment near KPAH at 10Z
closely, but it appears that the severe weather threat for early
this morning may not pan out. We have had some gusts 40 to 50 MPH
generally associated in or close to convective elements, and this
will likely continue through at least daybreak. The current band
of convection should continue to creep eastward and should be
exiting the southeast around 15Z. The latest HRRR was holding onto
it a bit longer til nearly 18Z, so the grids will keep likely pops
through the morning in the far southeast. To the northwest of this
band, little precipitation is expected until early afternoon.
Previous runs of the HRRR and other mesoscale models had been
generating discrete convection over the Evansville Tri State
ahead of the front from midday through mid afternoon. Isolated
supercell storms with the potential for all forms of severe
weather including significant tornadoes would be possible with these
storms if they develop. The latest few HRRR runs have not been
generating the pre-frontal activity, apparently due to some minor
capping developing in the wake of this mornings activity. Will
keep an emphasis in the PoP fields over the Tri State area through
the afternoon, but it will only be good chance to low end likelies
due to the discrete nature of the storms, if they can develop.
The one thing that seems to be a given in all of the models is for
a broken line of most likely discrete supercell thunderstorms to
develop southward along the eastward advancing cold front. This
activity should enter the far northwest portions of southern
Illinois around 19Z, and then continue to develop southward as the
whole line moves east through the afternoon. All of the convection
is expected to be east of the area by 00Z. Southeast Missouri as
well as the Purchase area of west Kentucky may come through this
event unscathed, as the frontal convection moves/develops
southeastward from southern Illinois into the Lakes and Pennyrile
region of west Kentucky late this afternoon. The full gamut of
severe weather will be possible with the frontal convection,
including significant tornadoes. These frontal storms may begin to
coalesce into a line or at least linear segments before exiting
the area. This would result in more of a bowing/damaging wind
threat.
As for the Wind Advisory, only the raw NAM winds are in support,
but given observations this morning the Advisory looks good. Did
modify the winds a bit to emphasize the northern half of the
southern Illinois and the Evansville Tri State for the strongest
winds. However, guidance has trended considerably lower with the
winds behind the cold front, so decided to expire the Advisory at
23Z, instead of the original 02Z.
High pressure will build across the area tonight. Modest west
northwest winds will bring much drier and cooler air to the
region. Did not stray too far from guidance for lows tonight.
Generally favored the warm side of guidance for highs today.
.LONG TERM...(Monday through Saturday)
ISSUED AT 423 AM CST SUN NOV 17 2013
Not much overall change for the extended portion of the forecast.
There is good model agreement with the synoptic features
influencing the area through Thursday, then there is much
divergence. Look for high pressure to finally settle over the
area Monday evening, allowing for good radiational cooling
overnight into Tuesday morning. Definitely undercut guidance for
lows Monday night.
The surface high will shift quickly east Tuesday into Tuesday
night, allowing for weak return southeasterly flow across the
area. As the flow aloft become southwesterly heading into Wednesday,
clouds will begin to increase, and a disturbance will bring a
chance of showers to the area Wednesday night into Thursday.
The ECMWF continues to have a dominant northern stream system and
brings Arctic surface high pressure into the area beginning late
Thursday. The GFS has a stronger southern stream which effectively
holds off the Arctic airmass about 24 hours later. Both models
indicate a decent chance of showers Thursday night into Friday,
but the temperatures would be much warmer if the GFS is right.
Tremendous bust potential here. This forecast still leans a bit
toward the warmer GFS solution. Both models are now clearing the
area out by Saturday morning with somewhat modified Arctic high
pressure building over the region.
&&
.AVIATION...
ISSUED AT 547 AM CST SUN NOV 17 2013
For the 12z Sunday WFO PAH TAF issuance, kept MVFR ceilings in
place through the frontal passage at each location. For
Thunderstorms, the use of vicinity thunder was kept given the
variability and coverage of thunderstorm this after over each of
the sites. Near term changes may be required as the frontal
boundary and associated convection move through later today.
Withing 1 to 3 hours of the cold frontal passage, skies were
cleared out and winds/wind gusts were reduced dramatically.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY until 5 PM CST this afternoon FOR ILZ075>078-
080>094.
MO...WIND ADVISORY until 5 PM CST this afternoon FOR MOZ076-086-087-
100-107>112-114.
IN...WIND ADVISORY until 5 PM CST this afternoon FOR INZ081-082-
085>088.
KY...WIND ADVISORY until 5 PM CST this afternoon FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...DRS
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS PADUCAH KY
424 AM CST Sun Nov 17 2013
.SHORT TERM...(Today and Tonight)
ISSUED AT 423 AM CST SUN NOV 17 2013
Will have to monitor the embedded linear segment near KPAH at 10Z
closely, but it appears that the severe weather threat for early
this morning may not pan out. We have had some gusts 40 to 50 MPH
generally associated in or close to convective elements, and this
will likely continue through at least daybreak. The current band
of convection should continue to creep eastward and should be
exiting the southeast around 15Z. The latest HRRR was holding onto
it a bit longer til nearly 18Z, so the grids will keep likely pops
through the morning in the far southeast. To the northwest of this
band, little precipitation is expected until early afternoon.
Previous runs of the HRRR and other mesoscale models had been
generating discrete convection over the Evansville Tri State
ahead of the front from midday through mid afternoon. Isolated
supercell storms with the potential for all forms of severe
weather including significant tornadoes would be possible with these
storms if they develop. The latest few HRRR runs have not been
generating the pre-frontal activity, apparently due to some minor
capping developing in the wake of this mornings activity. Will
keep an emphasis in the PoP fields over the Tri State area through
the afternoon, but it will only be good chance to low end likelies
due to the discrete nature of the storms, if they can develop.
The one thing that seems to be a given in all of the models is for
a broken line of most likely discrete supercell thunderstorms to
develop southward along the eastward advancing cold front. This
activity should enter the far northwest portions of southern
Illinois around 19Z, and then continue to develop southward as the
whole line moves east through the afternoon. All of the convection
is expected to be east of the area by 00Z. Southeast Missouri as
well as the Purchase area of west Kentucky may come through this
event unscathed, as the frontal convection moves/develops
southeastward from southern Illinois into the Lakes and Pennyrile
region of west Kentucky late this afternoon. The full gamut of
severe weather will be possible with the frontal convection,
including significant tornadoes. These frontal storms may begin to
coalesce into a line or at least linear segments before exiting
the area. This would result in more of a bowing/damaging wind
threat.
As for the Wind Advisory, only the raw NAM winds are in support,
but given observations this morning the Advisory looks good. Did
modify the winds a bit to emphasize the northern half of the
southern Illinois and the Evansville Tri State for the strongest
winds. However, guidance has trended considerably lower with the
winds behind the cold front, so decided to expire the Advisory at
23Z, instead of the original 02Z.
High pressure will build across the area tonight. Modest west
northwest winds will bring much drier and cooler air to the
region. Did not stray too far from guidance for lows tonight.
Generally favored the warm side of guidance for highs today.
.LONG TERM...(Monday through Saturday)
ISSUED AT 423 AM CST SUN NOV 17 2013
Not much overall change for the extended portion of the forecast.
There is good model agreement with the synoptic features
influencing the area through Thursday, then there is much
divergence. Look for high pressure to finally settle over the
area Monday evening, allowing for good radiational cooling
overnight into Tuesday morning. Definitely undercut guidance for
lows Monday night.
The surface high will shift quickly east Tuesday into Tuesday
night, allowing for weak return southeasterly flow across the
area. As the flow aloft become southwesterly heading into Wednesday,
clouds will begin to increase, and a disturbance will bring a
chance of showers to the area Wednesday night into Thursday.
The ECMWF continues to have a dominant northern stream system and
brings Arctic surface high pressure into the area beginning late
Thursday. The GFS has a stronger southern stream which effectively
holds off the Arctic airmass about 24 hours later. Both models
indicate a decent chance of showers Thursday night into Friday,
but the temperatures would be much warmer if the GFS is right.
Tremendous bust potential here. This forecast still leans a bit
toward the warmer GFS solution. Both models are now clearing the
area out by Saturday morning with somewhat modified Arctic high
pressure building over the region.
&&
.AVIATION...
ISSUED AT 1145 PM CST SAT NOV 16 2013
Strong southerly winds will only further escalate over the next 12
to 18 hours as a vigorous storm system ejects east from the Plains.
By Sunday afternoon, sustained 25 knot winds will frequently gust to
40 to 45 knots even in the absence of thunderstorms. Two time frames
continue to offer the greatest potential for convection. The first
unfolds overnight in response to the passage of an initial wave of
energy. Numerous showers and scattered thunderstorms are expected
with this first round. The second round of potentially severe
thunderstorms will focus during the afternoon hours Sunday as a
strong cold front plows through. MVFR ceilings and VFR visibilities
will prevail through much of the period, though a reduction to MVFR
or IFR conditions may occur beneath showers and thunderstorms. Winds
will shift to the west as skies clear in the wake of the passing
cold front Sunday evening. .. RJP ..
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY from 8 AM this morning to 5 PM CST this afternoon
FOR ILZ075>078-080>094.
MO...WIND ADVISORY from 8 AM this morning to 5 PM CST this afternoon
FOR MOZ076-086-087-100-107>112-114.
IN...WIND ADVISORY from 8 AM this morning to 5 PM CST this afternoon
FOR INZ081-082-085>088.
KY...WIND ADVISORY from 8 AM this morning to 5 PM CST this afternoon
FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...DRS
AVIATION...RJP
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
637 PM EST MON NOV 18 2013
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL CROSS THE AREA OVERNIGHT. HIGH
PRESSURE WILL BUILD IN FROM THE WEST TUESDAY THROUGH WEDNESDAY.
HIGH PRESSURE WILL SHIFT OFFSHORE WEDNESDAY NIGHT AND WILL REMAIN
ANCHORED OFF THE COAST THROUGH THURSDAY. A COLD FRONT WILL
APPROACH FROM THE WEST ON FRIDAY AND WILL CROSS THE REGION FRIDAY
NIGHT. LOW PRESSURE WILL APPROACH FROM THE NORTHWEST ON SATURDAY
AND WILL PUSH EAST THROUGH NORTHERN NEW ENGLAND SATURDAY NIGHT AND
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
.UPDATE...
INCREASED POPS SPATIALLY AS SHOWERS ARE NOW MOVING ACROSS SOUTHERN
NH AND INTO WESTERN MAINE. HRRR HAS THIS ACTIVITY SPREADING ACROSS
LEWISTON TO AUGUSTA BEFORE DISSIPATING OVER THE NEXT FEW HOURS.
CLOUDS WERE ALSO ADJUSTED...ALTHOUGH LARGE SWATHS OF THE REGION IS
CLEAR. THIS WILL HAVE AN IMPACT ON LOW TEMPERATURES AND WILL
UPDATE ACCORDINGLY.
&&
PREVIOUS DISCUSSION...
THE UPPER TROUGH WILL CROSS THE FORECAST AREA TONIGHT...BRINGING
IN SOME MID LEVEL CLOUDINESS AFTER MIDNIGHT. NORTHWEST FLOW TO
STRENGTHEN...SO EXPECT UPSLOPE MOISTURE AND A FEW SCATTERED SNOW
SHOWERS TO DEVELOP OVER THE NORTHWEST FACING HIGH TERRAIN. OVER
SOUTHERN AREAS...DOWNSLOPE CONDITIONS WILL KEEP MAINLY CLEAR SKIES
AND DRY CONDITIONS.
WITH STRONG COLD AIR ADVECTION AND INCREASING GRADIENT...WINDS
WILL INCREASE FURTHER AS WE APPROACH THE MORNING HOURS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
UPPER LEVEL TROUGH SHIFTS TO OUR EAST...ALLOWING WINDS TO ALIGN
THROUGH A DEEP LAYER. THEREFORE...EXPECT GUSTY CONDITIONS. USED A
BLEND OF MAV/MET MOS FOR DAYTIME HIGHS...BUT STILL KNOCKED THE
FORECAST DOWN A COUPLE DEGREES AS THE MAV APPEARED TO HAVE A WARM
BIAS.
THE SURFACE RIDGE WILL BEGIN TO BUILD OVER OUR REGION LATE TUESDAY
NIGHT. THIS WILL ALLOW FOR TEMPERATURES TO DROP QUICKLY...ESPECIALLY
IN THE WESTERN VALLEYS OF OUR FORECAST AREA. ENOUGH DRY AIR IN PLACE
TO KEEP FROM MUCH PATCHY FOG TO DEVELOP.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
QUIET START TO THE LONG TERM AS HIGH PRES BUILDS INTO THE REGION
WED AND THU. SFC RIDGE AXIS SETTLES OVER THE AREA EARLY THU...WITH
H8 TEMPS HOVERING RIGHT AROUND 0 C. GIVEN IDEAL RADIATIONAL
COOLING CONDITIONS...HAVE UNDERCUT GUIDANCE...WITH WIDESPREAD LOW
20S...AND TEENS IN THE MTNS...EXPECTED.
BY THE WEEKEND...BIG CHANGES ARE UNDERWAY AS A STRONG COLD FRONT
DRIVES INTO THE CENTER OF THE CONUS. NWP IS IN GOOD AGREEMENT THAT A
1050+ MB HIGH PRES BUILDS INTO THE NRN PLAINS...DRIVING THE
BAROCLINIC ZONE SWD. NRN STREAM S/WV TROF RACING OUT OF THE CANADIAN
PRAIRIES THEN SETS OFF CYCLOGENESIS IN VICINITY OF THE GREAT LAKES.
SFC HIGH PRES WILL BE IN THE PLACE TO THE N ON SAT. THIS SHOULD
ENSURE PLENTY OF LOW LEVEL COLD AIR IS IN PLACE...WHILE WAA ALOFT
WILL DRIVE THE PRODUCTION OF PRECIPITATION. THE EVOLUTION OF THE
RIDGING...SFC AND ALOFT...WILL DETERMINE THE ULTIMATE PATH OF LOW
PRES...BUT FOR NOW WILL SIDE WITH THE WRN SOLUTION. THIS MEANS A
PERIOD OF SNOWFALL FOLLOWED BY A TRANSITION TO RAIN. THE MOUNTAINS
APPEAR TO BE IN LINE FOR SOME ACCUMULATION...BEFORE ANY MIXING. IT
DOES APPEAR THIS STORM SYSTEM COULD BRING THE AREA THE FIRST
WIDESPREAD WINTRY PRECIPITATION.
IN THE SYSTEM/S WAKE THE COLDEST AIR OF THE SEASON LOOKS SET TO
ARRIVE VIA SECONDARY COLD FRONT LATE SUN. H8 TEMPS FALLING TO -15 OR
COLDER ARE BEING FORECAST BY THE GFS AND ECMWF ATTM. THIS WOULD
SUPPORT HIGH TEMPS STRUGGLING TO BREAK 32 DEG EARLY NEXT WEEK.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...VFR ACROSS THE FORECAST AREA THROUGH TUESDAY
NIGHT...EXCEPT FOR THE HIGHER TERRAIN.
LONG TERM...VFR CONDITIONS TO PREVAIL FOR MOST OF THE EXTENDED.
LOW PRES APPROACHES FORM THE W LATE IN THE PERIOD...WITH AREAS
OF MVFR OR LOWER DEVELOPING FROM W TO E SAT. -SN CHANGING OVER TO RA
IS THE MOST LIKELY SCENARIO OUTSIDE OF THE MOUNTAINS SAT INTO SUN.
&&
.MARINE...
SHORT TERM...WINDS ARE DOWN BUT WAVES ARE STILL RUNNING ABOVE 5
FEET...SO SCAS WILL REMAIN IN PLACE. WINDS INCREASE LATER TONIGHT
AS WELL TO SCA LEVELS AND CONTINUE RIGHT INTO WEDNESDAY.
LONG TERM...WINDS AND SEAS REMAIN BELOW SCA THRESHOLDS INTO THE
WEEKEND. LOW PRES APPROACHING FROM THE W WILL BRING WINDS AND SEAS
ABOVE SCA LEVELS SAT AND ESPECIALLY SUN.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST WEDNESDAY FOR ANZ150>154.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
634 AM EST SUN NOV 17 2013
.SYNOPSIS...
A MILD BUT WET DAY IS EXPECTED TODAY. A COLD FRONT WILL CROSS THE
REGION TONIGHT AND WILL PROVIDE WIDESPREAD SHOWERS AND STORMS.
COOLER AIR WILL ARRIVE ON TUESDAY AND WILL LAST THROUGH MUCH OF
THE WEEK. A STRONG COLD FRONT WILL USHER IN MUCH COLDER AIR NEXT
WEEKEND.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
UPDATES TO WX AND POP GRIDS TO REFLECT ONGOING AND XPCD EVOLUTION
OF SHWRS. HIGH-RESOLUTION MODELS SHOW THE SHIELD OF SHWRS
PERSISTING FOR MUCH OF THE DAY OVER WRN PA AND NRN WV. CNVCTN WILL
INCR IN CVRG IN FAR WRN ZONES LATE THIS AFTN AS PRIMARY SHRTWV
TROF APRCHS. IF THE HRRR IS TO BE BELIEVED...CELLULAR CNVCTN CAN
BE XPCD AHEAD OF THE PRIMARY CNVCTV LINE. THREATS AS OUTLINED BLW
WOULD APPLY IN SUCH A CASE...SO NO SGFNT CHGS TO LATE AFTN-OVNGT
PDS. PREV DISCUSSION FOLLOWS...
WMFNT OVER NRN KY WILL SHARPEN AND DVLP NWD TDA IN RESPONSE TO
APRCH OF VIGOROUS H5 SHRTWV TROF AND ATTENDANT DPNG SFC CYCLONE.
SFC LOW WILL BE LOCATED IN GRTLKS RGN BY 18/00Z AS NEGATIVELY-
TILTED UPR TROF ACCELERATES THRU THE RGN.
STRONG MSTR ADVCTN IN ASSOCIATION WITH POTENT LOW-LVL JET IS
UNDERWAY. SHWRS HAVE DVLPD AND WILL CONT THE LUGUBRIOUS CONDITIONS
PERIODICALLY THRU THE DAY. IN BETWEEN THESE EPISODES...MODEST
HEATING CAN BE XPCD...ENABLING POCKETS OF MODEST INSTBY TO FORM.
CELLULAR CNVCTN XPCD TO DVLP IN THE WARM SECTOR THIS AFTN IN
IL/IN/MI AS FORCING FOR ASCENT INCRS AND WIND FIELD BCMS INCRGLY
ORGANIZED. BY LATE THIS AFTN...HODOGRAPHS FROM IL TO WRN PA WILL
BE EXTREMELY SUPPORTIVE OF TORNADIC DVLPMT.
PRIMARY LMTG FACTOR FOR SVR WX THIS AFTN IN THE FCST AREA WILL BE
GENL LACK OF DP INSTBY. ANY SVR THREAT THIS AFTN WILL BE CONDITIONAL
ON DVLPMT OF DP MOIST CNVCTN. ATTM...IT APPEARS PRIMARY PCPN WILL
BE WEAKER SHWRS. IF MRNG PCPN CVRG IS LESS THAN ANTICIPATED...
BREAKS IN CLD CVR MAY PROMOTE MORE INSTBY AND POTL FOR EARLIER
ONSET OF SVR WX.
MAIN FOCUS FOR SVR WX WILL BE THIS EVE AS SFC TROF/CDFNT CROSS THE
RGN. VORTICITY-RICH ENVIRONMENT AMID EXTREME KINEMATICS AND INCRG
FORCING FOR ASCENT WILL SUPPORT VIGOROUS LINE OF CNVCTN CAPABLE OF
DMGG WIND GUSTS AND MESOVORTICES/TORNADOES. INDEED...HI-RES MODELS
DEPICT A WELL-ORGANIZED CNVCTV LINE DVLPG ALONG THIS BNDRY AND
IMPACTING ALL OF THE FCST AREA FROM 18/01Z-18/07Z. POCKETS OF SGFNT
WIND DMG ARE ANTICIPATED ALONG THIS BNDRY...PARTICULARLY WHERE
MESOVORTICES DVLP.
WDSPRD HVY RAIN IS NOT ANTICIPATED IN THIS EVENT OWING TO VERY
RAPID STORM MVMT. RAIN TOTALS BY MON MRNG COULD BE AS HIGH AS
RAPID CLRG XPCD IN WAKE OF THE BNDRY PASSAGE. LAPSE RATES IN THE
POST-FRONTAL AMS WILL STEEPEN CONSIDERABLY...PROMOTING DOWNWARD
MIXING OF HIGH-MOMENTUM AIR. WIND IN THIS MIXED LYR WILL EASILY
REACH 40 KT...WITH GUSTS XPCD TO APRCH OR EXCEED THIS MAGNITUDE
FOR A FEW HRS AFTER FROPA. THUS...WIND ADZY WILL BE IN EFFECT
AFTER FROPA THRU 12Z...WHEN GUSTINESS XPCD TO SUBSIDE.
LOW-LVL WINDS WILL VEER TO WNWLY MON EVE...PROMOTING MODEST FETCH
OFF LAKE ERIE COINCIDENT WITH ONSET OF SLGTLY COOLER AIR. ISOLD
LAKE-EFFECT AND LAKE-ENHANCED SHWRS XPCD TO DVLP MON NGT. WITH
TEMPS FALLING BLW FRZG DURG THIS TIME...VERY LGT SNOW ACCUMS WILL
BE PSBL IN NRN ZONES AND ALONG WEST-FACING SLOPES/RDGS. ARRIVAL OF
VERY DRY SFC AMS WILL BRING A RAPID END TO ANY PCPN LATE MON NGT.
MAXIMA TDA WILL BE IN THE LOW-MID 60S...WITH LOW 50S XPCD FOR HIGHS
ON MON. MINIMA WILL BE IN THE LOW-MID 40S TNGT AND UPR 20S-LWR 30S
MON NGT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
WHILE CYCLONIC NORTHWESTERLY FLOW CONTINUES OVER THE AREA INTO
MONDAY NIGHT AND TUESDAY...A VERY LEAN RH COLUMN LOOKS TO EXIST
AND IN FACT EVEN LOW LEVEL PROFILES BECOME STRONGLY INVERTED. AS A
RESULT...A DEARTH OF CLOUD COVER IS EXPECTED WITH COLD ADVECTION
REALLY ONLY APPARENT AT THE SURFACE...WHILE ALOFT WARM ADVECTION
WILL ALREADY BE KICKING IN. AS A RESULT...VERY STABLE AND DRY
CONDITIONS MEAN CLEAR SKIES...AND WIDE DIURNAL TEMPERATURE SPREADS
SEEM LIKELY TO CONTINUE THROUGH THE SHORT TERM PERIOD. FRIES
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
RUN-TO-RUN MODEL PERFORMANCE HAS BEEN LESS THAN STELLAR IN THE
EXTENDED FORECAST OVER THE PAST FEW CYCLES WITH REGARD TO THE
EVOLUTION FROM WEAK RIDGING MID-WEEK TO RATHER AMPLIFIED TROUGHING
BY NEXT WEEKEND OR SO. IN FACT...WHILE THE 00Z OPERATIONAL ECMWF
AND GFS BOTH SHOW INCREDIBLY LITTLE SPREAD...A DEEPER LOOK AT THE
GEFS MEMBERS AS WELL AS THE CANADIAN AND ITS ENSEMBLES REVEAL SAID
GLOBAL GUIDANCE AGREEMENT MAY BE SERENDIPITOUS MORE THAN IT IS
SKILLFUL. THAT SAID...A STRONG FASTER TREND IS NOTED IN THE
OPERATIONAL GFS/ECMWF LARGELY DUE TO A MORE PRONOUNCED CUTTING OFF
OF A LARGE UPPER CYCLONE OVER THE DESERT SOUTHWEST BY NEXT WEEKEND
UNDER A SPRAWLING UPPER RIDGE THAT ENCOMPASSES THE EASTERN PACIFIC
AND ALL OF THE INTERMOUNTAIN WEST. PREVIOUS MODEL RUNS HAD
ATTEMPTED TO MAINTAIN SOME DEGREE OF UPPER LEVEL CONNECTION
BETWEEN THE UPPER LOW THAT RETROGRADES TOWARD THE SOUTHWEST AND
THE DEEPENING NORTHERN STREAM UPPER TROUGH AS IT DIGS INTO THE
NORTHERN PLAINS. THE SOLUTIONS THAT MAINTAIN SOME UPPER LEVEL
CONNECTION OR ARE SLOWER TO SEVER SAID CONNECTION RETARD THE
PROGRESS OF THE UPPER TROUGH AND ASSOCIATED MUCH COLDER AIR TOWARD
OUR REGION.
WHILE THE SPEED AT WHICH COLD AIR ARRIVES IN THE AREA IS STILL TO
BE DETERMINED...THERE IS SEEMINGLY STRONG AGREEMENT THAT A DEEP
UPPER THROUGH WILL EVENTUALLY MAKES ITS WAY HERE SOMETIME BETWEEN
THE WEEKEND AND START OF NEXT WEEK. AS SUCH...DRY CONDITIONS ARE
LIKELY TO CONTINUE UNTIL SOUTHWESTERLY MOISTURE AND WARM ADVECTION
AHEAD OF THE ATTENDANT COLD FRONT ARRIVE IN THE AREA VERY LATE
THIS UPCOMING WEEKEND. POPS WERE INCREASED FRIDAY NIGHT AND
SATURDAY WITH THE MOST LIKELY TIME OF THE COLD FRONTAL PASSAGE
LIKELY TO BE ON SATURDAY AT THIS JUNCTURE. THAT
SAID...TEMPERATURES WERE ALLOWED TO STAY ELEVATED BEFORE SATURDAY
BEFORE TRANSITIONING MUCH COLDER BY SUNDAY. AN EARLY LOOK AT THE
DAY 8 GUIDANCE WOULD SUGGEST HIGHS BY SUNDAY UNDER 850 MB
TEMPERATURES OF -16 TO -20C OVER THE AREA WILL BE LIKELY TO REMAIN
LARGELY IN THE 20S. THIS WOULD BE ROUGHLY 20 DEGREES BELOW NORMAL
BY THAT TIME. AS SUCH...LAKE EFFECT SNOW SEEMS LIKELY TO RETURN TO
THE FORECAST BY THAT TIME AS WELL. FRIES
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
PERIODIC SHWRS XPCD TO IMPACT ALL TERMINALS THRU THE DAY. GENL
VFR/MVFR CONDS SHOULD PREDOMINATE OUTSIDE OF ANY SHWRS. WIND SHEAR
REMARKS WERE INCLD IN ALL TAFS THRU MID-MRNG OWING TO PRESENCE OF
STEEP INVERSION. THIS INVERSION WILL MIX OUT BY MID-MRNG...WITH
GUSTY SLY WINDS XPCD ALL TERMINALS.
ORGANIZED LINE OF SHWRS/TSTMS WILL MOVE THRU THE RGN TNGT IN
ASSOCIATION WITH SFC TROF/CDFNT. THE LINE SHOULD ENTER PA AROUND
18/03Z AND WILL CROSS THE APLCNS BY 18/06Z. THIS LINE LKLY WILL BE
ACCOMPANIED BY MDT RAIN AND BRIEF WIND GUSTS IN EXCESS OF 50-60
KT. CIGS AND VSBYS COULD BE REDUCED TO IFR OR LWR WHEN THE LINE
PASSES.
RAPID CLRG XPCD IN THE WAKE OF THE LINE. GUSTY WLY WINDS WILL
ENSUE FOR SVRL HRS OWING TO STEEP LOW-LVL LAPSE RATES IN THE POST-
FRONTAL AMS. VFR CONDS XPCD THRU MON.
.OUTLOOK.../MONDAY NIGHT THROUGH THURSDAY/...
VFR CONDITIONS WILL RETURN LATER TUESDAY AND CONTINUE INTO
THURSDAY AS HIGH PRESSURE BUILDS OVERHEAD.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND ADVISORY FROM 1 AM TO 7 AM EST MONDAY FOR MDZ001.
OH...WIND ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST MONDAY FOR
OHZ039>041-048>050-057>059-068-069.
PA...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EST MONDAY FOR
PAZ007>009-013>016-020>023-029-031-073-075.
WIND ADVISORY FROM 1 AM TO 7 AM EST MONDAY FOR PAZ074-076.
WV...WIND ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST MONDAY FOR
WVZ001>004-012.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EST MONDAY FOR
WVZ021-022.
WIND ADVISORY FROM 1 AM TO 7 AM EST MONDAY FOR WVZ023-041.
&&
$$
KRAMAR/FRIES
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1246 PM EST SUN NOV 17 2013
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 1245 PM EST SUN NOV 17 2013
SIGNIFICANT LINE OF SEVERE STORMS HAS ALREADY EVOLVED FROM SRN
WISCONSIN SOUTHWARD ACROSS ILLINOIS. ALL OF THIS ACTIVITY WILL BE
MOVING RAPIDLY INTO SRN LWR MI OVER THE NEXT FEW HOURS AT A VERY
HIGH RATE OF SPEED NEAR 60 MPH AND SHOULD CONGEAL INTO MORE OF A
SOLID SQUALL LINE.
SFC BASED INSTABILITY HAS NOT YET DEVELOPED IN SW LWR MI AND THE
CURRENT ACTIVITY IS IN AN AREA OF 1500 J/KG OF SFC BASED CAPE.
LATEST RAP13 GUIDANCE KEEPS OUR SFC BASED CAPES UNDER 500 J/KG
THROUGH 22Z THEN JUMPS ABOVE 500 J/KG AFTER 22Z. ALTHOUGH THE
INSTABILITY IN SW LWR MI WILL LIKELY BE LESS THAN UPSTREAM AS THIS
EVENT UNFOLDS... THE VERY STRONG SHEAR/DYNAMICS WILL PROBABLY
COMPENSATE WITH A SIGNIFICANT WIND THREAT STILL LIKELY.
THE SERIOUS TORNADO THREAT HAS BEEN HIGHLIGHTED IN ALL OF THE SPC
UPDATES AND STATEMENTS AND SEVERAL TORNADO WARNINGS ARE CURRENTLY
IN EFFECT UPSTREAM ACROSS ILLINOIS.
BOTTOM LINE... A SIGNIFICANT SEVERE WEATHER OUTBREAK IS GOING TO
HAPPEN SOON IN SW LWR MI... AND THE EVENT WILL PROGRESS VERY
QUICKLY.
&&
.SYNOPSIS...
ISSUED AT 326 AM EST SUN NOV 17 2013
PEOPLE IN SOUTHWEST LOWER MICHIGAN SHOULD PAY ATTENTION TO THE
WEATHER TODAY BECAUSE IT LOOKS LIKE WE/RE GOING TO SEE A SIGNIFICANT
WIND EVENT. A HIGH WIND WARNING IS IN EFFECT FOR ALL OF SOUTHWEST
LOWER MICHIGAN FROM 4 PM THIS AFTERNOON THROUGH 4 AM MONDAY.
A STRONG AUTUMN STORM WILL STRENGTHEN AS IT MOVES FROM IOWA
TOWARD THE LEELANAU PENINSULA. SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO DEVELOP TODAY AS A WARM FRONT MOVES NORTH. HOWEVER
THIS AFTERNOON...STORMS WILL LIKELY BECOME STRONG TO SEVERE AS
VERY STRONG DYNAMICS TAP INTO A MOISTURE RICH AIRMASS AHEAD OF THE
APPROACHING COLD FRONT. WIND GUSTS IN EXCESS OF 60 MPH ARE
POSSIBLE THIS AFTERNOON ALONG WITH ISOLATED TORNADOES. THE STORM
PREDICTION CENTER MAINTAINS A MODERATE RISK OF SEVERE STORMS
ACROSS CENTRAL LOWER MICHIGAN TODAY WITH A HIGH RISK REACHING INTO
SOUTHERN LOWER MICHIGAN.
MIXED RAIN/SNOW SHOWERS ARE EXPECTED MONDAY AS HIGHS FALL BACK TO
THE LOWER 40S.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 326 AM EST SUN NOV 17 2013
LATEST MODEL RUNS DIDN/T CHANGE THE THINKING THAT WE/RE STARING AT A
SIGNIFICANT WIND THREAT TODAY. STRONG TO SEVERE STORMS ARE POSSIBLE
ESPECIALLY THIS AFTERNOON FOLLOWED BY STRONG GRADIENT WINDS BEHIND
THE COLD FRONT LATE AFTERNOON AND EVENING. AS A RESULT WE ISSUED A
HIGH WIND WARNING THAT/S IN EFFECT FROM 4 PM TODAY THROUGH 4 AM
MONDAY.
A NEGATIVELY TILTED TROUGH WILL APPROACH THE GREAT LAKES. SFC LOW
PRESSURE IN THE MISSOURI VALLEY WILL MOVE TOWARD THE LEELANAU
PENINSULA LATE TODAY. A WARM FRONT LIFTING NORTH WILL BE AN INITIAL
FOCUS FOR CONVECTION. HOWEVER THE MAIN SHOW WILL BE THIS AFTERNOON
AHEAD OF THE COLD FRONT. A LOW LEVEL JET NEAR 65 KNOTS COUPLED WITH
A MID LEVEL JET NEAR 95 KNOTS WILL GENERATE SIGNIFICANT SHEAR THIS
AFTERNOON. IN ADDITION THE LEFT EXIT REGION OF THE UPPER JET WILL
MOVE OVER THE CWA LATE THIS AFTERNOON. IF WE CAN REALIZE CLOSE TO
THE 800 J/KG MLCAPE THE MODELS INDICATE WE SHOULD HAVE MORE THAN
ENOUGH FORCING AND ORGANIZATION FOR SUPERCELLS TO DEVELOP AHEAD OF
THE COLD FRONT. THE STRONG SHORT WAVE MOVING IN AT THE SAME TIME
WILL ONLY AID IN THE LIFT.
SPC MAINTAINS A MODERATE RISK FOR SEVERE STORMS WITH A HIGH RISK
JUST SOUTH OF THE CWA. CAN/T ARGUE WITH THAT. THE HRRR SHOWS A
BROKEN LINE OF STORMS ARRIVING AT THE SHORE AROUND 20Z. THIS
TIMING IS CONSISTENT WITH OTHER MODELS. THE MAIN SEVERE THREAT
LOOKS TO BE FROM 20Z THROUGH 01Z. AFTER THE COLD FRONT SWEEPS
THROUGH THE ATTENTION WILL TURN TO SYNOPTIC WINDS.
THE WIND THREAT WILL CONTINUE THIS EVENING. NAM SHOWS 3 HRLY
PRESSURE RISES IN THE 9-10 MB RANGE WHICH IS PRETTY HIGH AND SHOULD
RESULT IN HIGH WIND WARNING TYPE WINDS...ESPECIALLY ALONG THE COAST
WHERE GUSTS TO 55-65 MPH ARE POSSIBLE. STRONG COLD ADVECTION WILL
HELP TO PULL DOWN THE 55 KNOTS SEEN AT 900 FEET ON BUFKIT WIND
PROFILES. SURE SEEMS LIKE SCATTERED POWER OUTAGES WILL BE POSSIBLE
FROM THIS AFTERNOON THROUGH TONIGHT. WINDS WILL DIMINISH LATE
TONIGHT.
MIXED RAIN/SNOW SHOWERS POSSIBLE MONDAY/TUESDAY AS HIGHS ONLY CLIMB
INTO THE LOWER 40S.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 326 AM EST SUN NOV 17 2013
NO BIG STORMS IN THE EXTENDED. BUMPED UP MAXES A BIT ON WEDNESDAY AS
EURO HAS 850 MB TEMPS AROUND 5C WHICH LOOKS REASONABLE GIVEN DEEP
SOUTHERLY FLOW. ENOUGH MOISTURE MAY BE DRAWN NORTHWARD TO BRING SOME
SHOWERS BY WEDNESDAY NIGHT INTO THURSDAY AS IT POOLS IN FRONT OF
ADVANCING COLD FRONT.
COLDER AIR FILTERS IN FOR THURSDAY NIGHT AND FRIDAY WITH PRECIP
TRANSITIONING TO SNOW BY FRIDAY NIGHT. FORECAST CONFIDENCE IN THE
DETAILS IS LOW WITH POOR RUN TO RUN CONSISTENCY FOR FRIDAY AND
SATURDAY. THE GFS HAS A SFC LOW AND SECONDARY COLD FRONT COMING
THROUGH FRIDAY WHILE THE EURO IS FURTHER NORTH AND SLOWER WITH THE
LOW. SHOULD BE COLD ENOUGH FOR ALL SNOW BY FRIDAY NIGHT AND SATURDAY
IN EITHER SCENARIO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1200 PM EST SUN NOV 17 2013
WIDESPREAD MVFR/IFR CONDITIONS WILL CONTINUE THIS AFTERNOON. SEVERE
THUNDERSTORMS ARE EXPECTED THIS AFTERNOON WITH HIGH WIND GUSTS ALONG
WITH POTENTIAL FOR HAIL AND EVEN A FEW TORNADOES. ONCE THIS MOVES
THROUGH...HIGH WIND THREAT CONTINUES WITH WIDESPREAD GUSTS OVER 40
MPH AND AS HIGH AS 60 MPH DURING THE EVENING. WINDS WILL START OUT
SOUTH EARLY THIS AFTERNOON...GO SOUTHWEST LATER THIS AFTERNOON AND
THEN WEST LATER TONIGHT.
&&
.MARINE...
ISSUED AT 326 AM EST SUN NOV 17 2013
UPGRADED THE GALE WARNING TO A STORM WARNING. IN ADDITION TO STRONG
TO SEVERE THUNDERSTORMS TODAY STRONG GRADIENT WINDS WILL DEVELOP
BEHIND A COLD FRONT LATE THIS AFTERNOON. WEST STORM FORCE WINDS TO
55 KNOTS ARE EXPECTED THROUGH THE EARLY OVERNIGHT HOURS BEFORE
DECREASING TO 40 KNOT GALES. WAVES WILL BUILD TO 10 TO 15 FEET
TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 326 AM EST SUN NOV 17 2013
HEAVY RAINFALL POSSIBLE IN STORMS TODAY...ESPECIALLY THIS AFTERNOON.
LOOK FOR ADDITIONAL RAINFALL ACCUMULATIONS AROUND AN INCH THROUGH
EARLY EVENING. THIS LIKELY WON`T CAUSE RIVER FLOODING. HOWEVER
LOCALIZED FLOODING MAY DEVELOP IN POOR DRAINAGE AREAS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY
FOR MIZ037>040-043>046-050>052-056>059-064>067-071>074.
LM...STORM WARNING UNTIL 4 AM EST MONDAY FOR LMZ844>849.
&&
$$
MESOSCALE...MEADE
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...LAURENS
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1200 PM EST SUN NOV 17 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 326 AM EST SUN NOV 17 2013
PEOPLE IN SOUTHWEST LOWER MICHIGAN SHOULD PAY ATTENTION TO THE
WEATHER TODAY BECAUSE IT LOOKS LIKE WE/RE GOING TO SEE A SIGNIFICANT
WIND EVENT. A HIGH WIND WARNING IS IN EFFECT FOR ALL OF SOUTHWEST
LOWER MICHIGAN FROM 4 PM THIS AFTERNOON THROUGH 4 AM MONDAY.
A STRONG AUTUMN STORM WILL STRENGTHEN AS IT MOVES FROM IOWA
TOWARD THE LEELANAU PENINSULA. SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO DEVELOP TODAY AS A WARM FRONT MOVES NORTH. HOWEVER
THIS AFTERNOON...STORMS WILL LIKELY BECOME STRONG TO SEVERE AS
VERY STRONG DYNAMICS TAP INTO A MOISTURE RICH AIRMASS AHEAD OF THE
APPROACHING COLD FRONT. WIND GUSTS IN EXCESS OF 60 MPH ARE
POSSIBLE THIS AFTERNOON ALONG WITH ISOLATED TORNADOES. THE STORM
PREDICTION CENTER MAINTAINS A MODERATE RISK OF SEVERE STORMS
ACROSS CENTRAL LOWER MICHIGAN TODAY WITH A HIGH RISK REACHING INTO
SOUTHERN LOWER MICHIGAN.
MIXED RAIN/SNOW SHOWERS ARE EXPECTED MONDAY AS HIGHS FALL BACK TO
THE LOWER 40S.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 326 AM EST SUN NOV 17 2013
LATEST MODEL RUNS DIDN/T CHANGE THE THINKING THAT WE/RE STARING AT A
SIGNIFICANT WIND THREAT TODAY. STRONG TO SEVERE STORMS ARE POSSIBLE
ESPECIALLY THIS AFTERNOON FOLLOWED BY STRONG GRADIENT WINDS BEHIND
THE COLD FRONT LATE AFTERNOON AND EVENING. AS A RESULT WE ISSUED A
HIGH WIND WARNING THAT/S IN EFFECT FROM 4 PM TODAY THROUGH 4 AM
MONDAY.
A NEGATIVELY TILTED TROUGH WILL APPROACH THE GREAT LAKES. SFC LOW
PRESSURE IN THE MISSOURI VALLEY WILL MOVE TOWARD THE LEELANAU
PENINSULA LATE TODAY. A WARM FRONT LIFTING NORTH WILL BE AN INITIAL
FOCUS FOR CONVECTION. HOWEVER THE MAIN SHOW WILL BE THIS AFTERNOON
AHEAD OF THE COLD FRONT. A LOW LEVEL JET NEAR 65 KNOTS COUPLED WITH
A MID LEVEL JET NEAR 95 KNOTS WILL GENERATE SIGNIFICANT SHEAR THIS
AFTERNOON. IN ADDITION THE LEFT EXIT REGION OF THE UPPER JET WILL
MOVE OVER THE CWA LATE THIS AFTERNOON. IF WE CAN REALIZE CLOSE TO
THE 800 J/KG MLCAPE THE MODELS INDICATE WE SHOULD HAVE MORE THAN
ENOUGH FORCING AND ORGANIZATION FOR SUPERCELLS TO DEVELOP AHEAD OF
THE COLD FRONT. THE STRONG SHORT WAVE MOVING IN AT THE SAME TIME
WILL ONLY AID IN THE LIFT.
SPC MAINTAINS A MODERATE RISK FOR SEVERE STORMS WITH A HIGH RISK
JUST SOUTH OF THE CWA. CAN/T ARGUE WITH THAT. THE HRRR SHOWS A
BROKEN LINE OF STORMS ARRIVING AT THE SHORE AROUND 20Z. THIS
TIMING IS CONSISTENT WITH OTHER MODELS. THE MAIN SEVERE THREAT
LOOKS TO BE FROM 20Z THROUGH 01Z. AFTER THE COLD FRONT SWEEPS
THROUGH THE ATTENTION WILL TURN TO SYNOPTIC WINDS.
THE WIND THREAT WILL CONTINUE THIS EVENING. NAM SHOWS 3 HRLY
PRESSURE RISES IN THE 9-10 MB RANGE WHICH IS PRETTY HIGH AND SHOULD
RESULT IN HIGH WIND WARNING TYPE WINDS...ESPECIALLY ALONG THE COAST
WHERE GUSTS TO 55-65 MPH ARE POSSIBLE. STRONG COLD ADVECTION WILL
HELP TO PULL DOWN THE 55 KNOTS SEEN AT 900 FEET ON BUFKIT WIND
PROFILES. SURE SEEMS LIKE SCATTERED POWER OUTAGES WILL BE POSSIBLE
FROM THIS AFTERNOON THROUGH TONIGHT. WINDS WILL DIMINISH LATE
TONIGHT.
MIXED RAIN/SNOW SHOWERS POSSIBLE MONDAY/TUESDAY AS HIGHS ONLY CLIMB
INTO THE LOWER 40S.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 326 AM EST SUN NOV 17 2013
NO BIG STORMS IN THE EXTENDED. BUMPED UP MAXES A BIT ON WEDNESDAY AS
EURO HAS 850 MB TEMPS AROUND 5C WHICH LOOKS REASONABLE GIVEN DEEP
SOUTHERLY FLOW. ENOUGH MOISTURE MAY BE DRAWN NORTHWARD TO BRING SOME
SHOWERS BY WEDNESDAY NIGHT INTO THURSDAY AS IT POOLS IN FRONT OF
ADVANCING COLD FRONT.
COLDER AIR FILTERS IN FOR THURSDAY NIGHT AND FRIDAY WITH PRECIP
TRANSITIONING TO SNOW BY FRIDAY NIGHT. FORECAST CONFIDENCE IN THE
DETAILS IS LOW WITH POOR RUN TO RUN CONSISTENCY FOR FRIDAY AND
SATURDAY. THE GFS HAS A SFC LOW AND SECONDARY COLD FRONT COMING
THROUGH FRIDAY WHILE THE EURO IS FURTHER NORTH AND SLOWER WITH THE
LOW. SHOULD BE COLD ENOUGH FOR ALL SNOW BY FRIDAY NIGHT AND SATURDAY
IN EITHER SCENARIO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1200 PM EST SUN NOV 17 2013
WIDESPREAD MVFR/IFR CONDITIONS WILL CONTINUE THIS AFTERNOON. SEVERE
THUNDERSTORMS ARE EXPECTED THIS AFTERNOON WITH HIGH WIND GUSTS ALONG
WITH POTENTIAL FOR HAIL AND EVEN A FEW TORNADOES. ONCE THIS MOVES
THROUGH...HIGH WIND THREAT CONTINUES WITH WIDESPREAD GUSTS OVER 40
MPH AND AS HIGH AS 60 MPH DURING THE EVENING. WINDS WILL START OUT
SOUTH EARLY THIS AFTERNOON...GO SOUTHWEST LATER THIS AFTERNOON AND
THEN WEST LATER TONIGHT.
&&
.MARINE...
ISSUED AT 326 AM EST SUN NOV 17 2013
UPGRADED THE GALE WARNING TO A STORM WARNING. IN ADDITION TO STRONG
TO SEVERE THUNDERSTORMS TODAY STRONG GRADIENT WINDS WILL DEVELOP
BEHIND A COLD FRONT LATE THIS AFTERNOON. WEST STORM FORCE WINDS TO
55 KNOTS ARE EXPECTED THROUGH THE EARLY OVERNIGHT HOURS BEFORE
DECREASING TO 40 KNOT GALES. WAVES WILL BUILD TO 10 TO 15 FEET
TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 326 AM EST SUN NOV 17 2013
HEAVY RAINFALL POSSIBLE IN STORMS TODAY...ESPECIALLY THIS AFTERNOON.
LOOK FOR ADDITIONAL RAINFALL ACCUMULATIONS AROUND AN INCH THROUGH
EARLY EVENING. THIS LIKELY WON`T CAUSE RIVER FLOODING. HOWEVER
LOCALIZED FLOODING MAY DEVELOP IN POOR DRAINAGE AREAS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY
FOR MIZ037>040-043>046-050>052-056>059-064>067-071>074.
LM...STORM WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR
LMZ844>849.
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ844>849.
&&
$$
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...LAURENS
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
655 AM EST SUN NOV 17 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 326 AM EST SUN NOV 17 2013
PEOPLE IN SOUTHWEST LOWER MICHIGAN SHOULD PAY ATTENTION TO THE
WEATHER TODAY BECAUSE IT LOOKS LIKE WE/RE GOING TO SEE A SIGNIFICANT
WIND EVENT. A HIGH WIND WARNING IS IN EFFECT FOR ALL OF SOUTHWEST
LOWER MICHIGAN FROM 4 PM THIS AFTERNOON THROUGH 4 AM MONDAY.
A STRONG AUTUMN STORM WILL STRENGTHEN AS IT MOVES FROM IOWA
TOWARD THE LEELANAU PENINSULA. SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO DEVELOP TODAY AS A WARM FRONT MOVES NORTH. HOWEVER
THIS AFTERNOON...STORMS WILL LIKELY BECOME STRONG TO SEVERE AS
VERY STRONG DYNAMICS TAP INTO A MOISTURE RICH AIRMASS AHEAD OF THE
APPROACHING COLD FRONT. WIND GUSTS IN EXCESS OF 60 MPH ARE
POSSIBLE THIS AFTERNOON ALONG WITH ISOLATED TORNADOES. THE STORM
PREDICTION CENTER MAINTAINS A MODERATE RISK OF SEVERE STORMS
ACROSS CENTRAL LOWER MICHIGAN TODAY WITH A HIGH RISK REACHING INTO
SOUTHERN LOWER MICHIGAN.
MIXED RAIN/SNOW SHOWERS ARE EXPECTED MONDAY AS HIGHS FALL BACK TO
THE LOWER 40S.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 326 AM EST SUN NOV 17 2013
LATEST MODEL RUNS DIDN/T CHANGE THE THINKING THAT WE/RE STARING AT A
SIGNIFICANT WIND THREAT TODAY. STRONG TO SEVERE STORMS ARE POSSIBLE
ESPECIALLY THIS AFTERNOON FOLLOWED BY STRONG GRADIENT WINDS BEHIND
THE COLD FRONT LATE AFTERNOON AND EVENING. AS A RESULT WE ISSUED A
HIGH WIND WARNING THAT/S IN EFFECT FROM 4 PM TODAY THROUGH 4 AM
MONDAY.
A NEGATIVELY TILTED TROUGH WILL APPROACH THE GREAT LAKES. SFC LOW
PRESSURE IN THE MISSOURI VALLEY WILL MOVE TOWARD THE LEELANAU
PENINSULA LATE TODAY. A WARM FRONT LIFTING NORTH WILL BE AN INITIAL
FOCUS FOR CONVECTION. HOWEVER THE MAIN SHOW WILL BE THIS AFTERNOON
AHEAD OF THE COLD FRONT. A LOW LEVEL JET NEAR 65 KNOTS COUPLED WITH
A MID LEVEL JET NEAR 95 KNOTS WILL GENERATE SIGNIFICANT SHEAR THIS
AFTERNOON. IN ADDITION THE LEFT EXIT REGION OF THE UPPER JET WILL
MOVE OVER THE CWA LATE THIS AFTERNOON. IF WE CAN REALIZE CLOSE TO
THE 800 J/KG MLCAPE THE MODELS INDICATE WE SHOULD HAVE MORE THAN
ENOUGH FORCING AND ORGANIZATION FOR SUPERCELLS TO DEVELOP AHEAD OF
THE COLD FRONT. THE STRONG SHORT WAVE MOVING IN AT THE SAME TIME
WILL ONLY AID IN THE LIFT.
SPC MAINTAINS A MODERATE RISK FOR SEVERE STORMS WITH A HIGH RISK
JUST SOUTH OF THE CWA. CAN/T ARGUE WITH THAT. THE HRRR SHOWS A
BROKEN LINE OF STORMS ARRIVING AT THE SHORE AROUND 20Z. THIS
TIMING IS CONSISTENT WITH OTHER MODELS. THE MAIN SEVERE THREAT
LOOKS TO BE FROM 20Z THROUGH 01Z. AFTER THE COLD FRONT SWEEPS
THROUGH THE ATTENTION WILL TURN TO SYNOPTIC WINDS.
THE WIND THREAT WILL CONTINUE THIS EVENING. NAM SHOWS 3 HRLY
PRESSURE RISES IN THE 9-10 MB RANGE WHICH IS PRETTY HIGH AND SHOULD
RESULT IN HIGH WIND WARNING TYPE WINDS...ESPECIALLY ALONG THE COAST
WHERE GUSTS TO 55-65 MPH ARE POSSIBLE. STRONG COLD ADVECTION WILL
HELP TO PULL DOWN THE 55 KNOTS SEEN AT 900 FEET ON BUFKIT WIND
PROFILES. SURE SEEMS LIKE SCATTERED POWER OUTAGES WILL BE POSSIBLE
FROM THIS AFTERNOON THROUGH TONIGHT. WINDS WILL DIMINISH LATE
TONIGHT.
MIXED RAIN/SNOW SHOWERS POSSIBLE MONDAY/TUESDAY AS HIGHS ONLY CLIMB
INTO THE LOWER 40S.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 326 AM EST SUN NOV 17 2013
NO BIG STORMS IN THE EXTENDED. BUMPED UP MAXES A BIT ON WEDNESDAY AS
EURO HAS 850 MB TEMPS AROUND 5C WHICH LOOKS REASONABLE GIVEN DEEP
SOUTHERLY FLOW. ENOUGH MOISTURE MAY BE DRAWN NORTHWARD TO BRING SOME
SHOWERS BY WEDNESDAY NIGHT INTO THURSDAY AS IT POOLS IN FRONT OF
ADVANCING COLD FRONT.
COLDER AIR FILTERS IN FOR THURSDAY NIGHT AND FRIDAY WITH PRECIP
TRANSITIONING TO SNOW BY FRIDAY NIGHT. FORECAST CONFIDENCE IN THE
DETAILS IS LOW WITH POOR RUN TO RUN CONSISTENCY FOR FRIDAY AND
SATURDAY. THE GFS HAS A SFC LOW AND SECONDARY COLD FRONT COMING
THROUGH FRIDAY WHILE THE EURO IS FURTHER NORTH AND SLOWER WITH THE
LOW. SHOULD BE COLD ENOUGH FOR ALL SNOW BY FRIDAY NIGHT AND SATURDAY
IN EITHER SCENARIO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 655 AM EST SUN NOV 17 2013
WIDESPREAD MVFR AND PATCHY IFR CONDITIONS THIS MORNING IN ADVANCE
OF A SQUALL LINE EXPECTED TO MOVE THROUGH FROM WEST TO EAST
BETWEEN 19Z TO 22Z. WIND GUSTS WITH THE SQUALL LINE COULD BE IN
EXCESS OF 50 KNOTS ALONG WITH THE POTENTIAL FOR LARGE HAIL AND
TORNADOES. ONCE THIS MOVES THROUGH...HIGH WIND THREAT CONTINUES
WITH WIDESPREAD GUSTS OVER 40 MPH AND AS HIGH AS 60 MPH DURING THE
EVENING. WINDS WILL START OUT SOUTH THIS MORNING...GO SOUTHWEST
THIS AFTERNOON AND THEN WEST LATER TONIGHT.
&&
.MARINE...
ISSUED AT 326 AM EST SUN NOV 17 2013
UPGRADED THE GALE WARNING TO A STORM WARNING. IN ADDITION TO STRONG
TO SEVERE THUNDERSTORMS TODAY STRONG GRADIENT WINDS WILL DEVELOP
BEHIND A COLD FRONT LATE THIS AFTERNOON. WEST STORM FORCE WINDS TO
55 KNOTS ARE EXPECTED THROUGH THE EARLY OVERNIGHT HOURS BEFORE
DECREASING TO 40 KNOT GALES. WAVES WILL BUILD TO 10 TO 15 FEET
TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 326 AM EST SUN NOV 17 2013
HEAVY RAINFALL POSSIBLE IN STORMS TODAY...ESPECIALLY THIS AFTERNOON.
LOOK FOR ADDITIONAL RAINFALL ACCUMULATIONS AROUND AN INCH THROUGH
EARLY EVENING. THIS LIKELY WON`T CAUSE RIVER FLOODING. HOWEVER
LOCALIZED FLOODING MAY DEVELOP IN POOR DRAINAGE AREAS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY
FOR MIZ037>040-043>046-050>052-056>059-064>067-071>074.
LM...STORM WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR
LMZ844>849.
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ844>849.
&&
$$
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
326 AM EST SUN NOV 17 2013
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE
.SYNOPSIS...
ISSUED AT 326 AM EST SUN NOV 17 2013
PEOPLE IN SOUTHWEST LOWER MICHIGAN SHOULD PAY ATTENTION TO THE
WEATHER TODAY BECAUSE IT LOOKS LIKE WE/RE GOING TO SEE A SIGNIFICANT
WIND EVENT. A HIGH WIND WARNING IS IN EFFECT FOR ALL OF SOUTHWEST
LOWER MICHIGAN FROM 4 PM THIS AFTERNOON THROUGH 4 AM MONDAY.
A STRONG AUTUMN STORM WILL MOVE STRENGTHEN AS IT MOVES FROM IOWA
TOWARD THE LEELANAU PENINSULA. SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO DEVELOP TODAY AS A WARM FRONT MOVES NORTH. HOWEVER THIS
AFTERNOON...STORMS WILL LIKELY BECOME STRONG TO SEVERE AS VERY
STRONG DYNAMICS TAP INTO A MOISTURE RICH AIRMASS AHEAD OF THE
APPROACHING COLD FRONT. WIND GUSTS IN EXCESS OF 60 MPH ARE POSSIBLE
THIS AFTERNOON ALONG WITH ISOLATED TORNADOES. THE STORM PREDICTION
CENTER MAINTAINS A MODERATE RISK OF SEVERE STORMS ACROSS SOUTHWEST
LOWER MICHIGAN TODAY WITH A HIGH RISK JUST TO THE SOUTH.
MIXED RAIN/SNOW SHOWERS ARE EXPECTED MONDAY AS HIGHS FALL BACK TO
THE LOWER 40S.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 326 AM EST SUN NOV 17 2013
LATEST MODEL RUNS DIDN/T CHANGE THE THINKING THAT WE/RE STARING AT A
SIGNIFICANT WIND THREAT TODAY. STRONG TO SEVERE STORMS ARE POSSIBLE
ESPECIALLY THIS AFTERNOON FOLLOWED BY STRONG GRADIENT WINDS BEHIND
THE COLD FRONT LATE AFTERNOON AND EVENING. AS A RESULT WE ISSUED A
HIGH WIND WARNING THAT/S IN EFFECT FROM 4 PM TODAY THROUGH 4 AM
MONDAY.
A NEGATIVELY TILTED TROUGH WILL APPROACH THE GREAT LAKES. SFC LOW
PRESSURE IN THE MISSOURI VALLEY WILL MOVE TOWARD THE LEELANAU
PENINSULA LATE TODAY. A WARM FRONT LIFTING NORTH WILL BE AN INITIAL
FOCUS FOR CONVECTION. HOWEVER THE MAIN SHOW WILL BE THIS AFTERNOON
AHEAD OF THE COLD FRONT. A LOW LEVEL JET NEAR 65 KNOTS COUPLED WITH
A MID LEVEL JET NEAR 95 KNOTS WILL GENERATE SIGNIFICANT SHEAR THIS
AFTERNOON. IN ADDITION THE LEFT EXIT REGION OF THE UPPER JET WILL
MOVE OVER THE CWA LATE THIS AFTERNOON. IF WE CAN REALIZE CLOSE TO
THE 800 J/KG MLCAPE THE MODELS INDICATE WE SHOULD HAVE MORE THAN
ENOUGH FORCING AND ORGANIZATION FOR SUPERCELLS TO DEVELOP AHEAD OF
THE COLD FRONT. THE STRONG SHORT WAVE MOVING IN AT THE SAME TIME
WILL ONLY AID IN THE LIFT. SPC MAINTAINS A MODERATE RISK FOR SEVERE
STORMS WITH A HIGH RISK JUST SOUTH OF THE CWA. CAN/T ARGUE WITH
THAT. THE HRRR SHOWS A BROKEN LINE OF STORMS ARRIVING AT THE SHORE
AROUND 20Z. THIS TIMING IS CONSISTENT WITH OTHER MODELS. THE MAIN
SEVERE THREAT LOOKS TO BE FROM 20Z THROUGH 01Z. AFTER THE COLD FRONT
SWEEPS THROUGH THE ATTENTION WILL TURN TO SYNOPTIC WINDS.
THE WIND THREAT WILL CONTINUE THIS EVENING. NAM SHOWS 3 HRLY
PRESSURE RISES IN THE 9-10 MB RANGE WHICH IS PRETTY HIGH AND SHOULD
RESULT IN HIGH WIND WARNING TYPE WINDS...ESPECIALLY ALONG THE COAST
WHERE GUSTS TO 55-65 MPH ARE POSSIBLE. STRONG COLD ADVECTION WILL
HELP TO PULL DOWN THE 55 KNOTS SEEN AT 900 FEET ON BUFKIT WIND
PROFILES. SURE SEEMS LIKE SCATTERED POWER OUTAGES WILL BE POSSIBLE
FROM THIS AFTERNOON THROUGH TONIGHT. WINDS WILL DIMINISH LATE
TONIGHT.
MIXED RAIN/SNOW SHOWERS POSSIBLE MONDAY/TUESDAY AS HIGHS ONLY CLIMB
INTO THE LOWER 40S.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 326 AM EST SUN NOV 17 2013
NO BIG STORMS IN THE EXTENDED. BUMPED UP MAXES A BIT ON WEDNESDAY AS
EURO HAS 850 MB TEMPS AROUND 5C WHICH LOOKS REASONABLE GIVEN DEEP
SOUTHERLY FLOW. ENOUGH MOISTURE MAY BE DRAWN NORTHWARD TO BRING SOME
SHOWERS BY WEDNESDAY NIGHT INTO THURSDAY AS IT POOLS IN FRONT OF
ADVANCING COLD FRONT.
COLDER AIR FILTERS IN FOR THURSDAY NIGHT AND FRIDAY WITH PRECIP
TRANSITIONING TO SNOW BY FRIDAY NIGHT. FORECAST CONFIDENCE IN THE
DETAILS IS LOW WITH POOR RUN TO RUN CONSISTENCY FOR FRIDAY AND
SATURDAY. THE GFS HAS A SFC LOW AND SECONDARY COLD FRONT COMING
THROUGH FRIDAY WHILE THE EURO IS FURTHER NORTH AND SLOWER WITH THE
LOW. SHOULD BE COLD ENOUGH FOR ALL SNOW BY FRIDAY NIGHT AND SATURDAY
IN EITHER SCENARIO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1149 PM EST SAT NOV 16 2013
INITIAL BATCH OF SHOWER PUSHING THROUGH THE REGION AT THIS TIME
WITH WIDESPREAD MVFR AND SOME IFR STARTING TO SHOW UP. THE TREND
WILL BE MORE IFR THROUGH THE NIGHT...THE WILL PERSIST FOR MUCH OF
SUNDAY. THUNDERSTORMS WILL BECOME MORE LIKELY LATE TONIGHT AND
INTO SUNDAY AS THE ATMOSPHERE DESTABILIZES. THE COLD FRONT PUSHES
THROUGH LATER SUNDAY SENDING THE STORMS OFF TO THE EAST OF KLAN BY
00Z. WINDS WILL GUSTS WELL OVER 25 KNOTS AT TIMES SUNDAY AND
ESPECIALLY SUNDAY NIGHT. GUSTS OF 40 KNOTS APPEAR LIKELY
ACCOMPANYING THE STORMS AND ALSO BEHIND THE COLD FRONT FOR SUNDAY
EVENING.
&&
.MARINE...
ISSUED AT 326 AM EST SUN NOV 17 2013
UPGRADED THE GALE WARNING TO A STORM WARNING. IN ADDITION TO STRONG
TO SEVERE THUNDERSTORMS TODAY STRONG GRADIENT WINDS WILL DEVELOP
BEHIND A COLD FRONT LATE THIS AFTERNOON. WEST STORM FORCE WINDS TO
55 KNOTS ARE EXPECTED THROUGH THE EARLY OVERNIGHT HOURS BEFORE
DECREASING TO 40 KNOT GALES. WAVES WILL BUILD TO 10 TO 15 FEET
TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 326 AM EST SUN NOV 17 2013
HEAVY RAINFALL POSSIBLE IN STORMS TODAY...ESPECIALLY THIS AFTERNOON.
LOOK FOR ADDITIONAL RAINFALL ACCUMULATIONS AROUND AN INCH THROUGH
EARLY EVENING. THIS LIKELY WON`T CAUSE RIVER FLOODING. HOWEVER
LOCALIZED FLOODING MAY DEVELOP IN POOR DRAINAGE AREAS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY
FOR MIZ037>040-043>046-050>052-056>059-064>067-071>074.
LM...STORM WARNING FROM 4 PM THIS AFTERNOON TO 4 AM EST MONDAY FOR
LMZ844>849.
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LMZ844>849.
&&
$$
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...MJS
HYDROLOGY...93
MARINE...93
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
624 AM CST SUN NOV 17 2013
.UPDATE...FOR 12Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CST SUN NOV 17 2013
THE SURFACE LOW HAD ENTERED NORTHEASTERN MN BY 09Z THIS MORNING. FOG
AND STRATUS CLOUDS ON THE WEST/SOUTHWEST PERIPHERY OF THE LOW
PLAGUED NORTH CENTRAL INTO WEST CENTRAL MN OVERNIGHT. AS THE LOW
MEANDERS NORTH AND EAST THIS MORNING...NORTHWEST WINDS WILL
STRENGTHEN. SHOULD SEE FOG IMPROVE DURING THE MID TO LATE
MORNING...BUT CYCLONIC FLOW WILL LIKELY BE CONDUCIVE TO PROLONGED
LOW CLOUD COVER...WITH THE EXCEPTION OF WEST AND SOUTH CENTRAL MN
WHERE SOME AFTERNOON BREAKS ARE POSSIBLE. THE EXTENSIVE CLOUD COVER
AND COLD AIR ADVECTION TODAY WILL RESULT IN LIMITED DIURNAL
WARMING...WITH HIGH TEMPERATURES IN THE 40S. PRECIPITATION IS
EXPECTED TO STAY CONFINED TO THE FAR SOUTHERN/SOUTHEASTERN PORTION
OF THE FORECAST AREA /SOUTH CENTRAL MN NORTHEAST TO NEAR EAU CLAIRE
WI/ DURING THE DAYTIME HOURS. ADDITIONAL RAINFALL AMOUNTS SHOULD MAX OUT
AROUND ONE TENTH OF AN INCH OR LESS. A VERY BRIEF PERIOD OF SNOW
WILL BE POSSIBLE IN THE NORTHEAST NEAR LADYSMITH TONIGHT...BUT THE
PRECIP IS EXPECTED TO PRETTY MUCH BE FINISHED BY THE TIME IT
TRANSITIONS TO SNOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 410 AM CST SUN NOV 17 2013
RELATIVELY QUIET WEATHER IS EXPECTED FOR THE UPCOMING WEEK ONCE
THIS POWERFUL CYCLONE EXITS THE REGION. THE MAIN CONCERN IS TRYING
TO TIME THE COLD FRONT THAT WILL MOVE THROUGH AND WEDNESDAY...AND
ANY ASSOCIATED PRECIP THAT MAY ACCOMPANY IT.
AT THE START OF THE PERIOD HIGH PRESSURE WILL BE BUILDING ACROSS THE
UPPER MIDWEST...AND THE LARGE SCALE SUBSIDENCE RESPONSIBLE FOR THIS
SURFACE HIGH WILL KEEP THE REGION DRY. AS THIS HIGH SLIDES EASTWARD
WARM AIR ADVECTION WILL OVERSPREAD THE WEST LATE MONDAY INTO TUESDAY
NIGHT. FORECAST SOUNDINGS FOR TUESDAY OFF THE GFS SHOW SOUTHERLY
WINDS OF 20KTS THROUGHOUT THE MIXED LAYER WITH ONLY A FEW HIGH
CLOUDS POSSIBLE. THIS SHOULD RESULT IN AFTERNOON TEMPERATURES
SIMILAR TO THE PAST COUPLE OF DAYS...SO RAISED TEMPERATURES ABOVE
GUIDANCE WITH MID 50S ON THE LEE SIDE OF THE BUFFALO
RIDGE...TAPERING TO UPPER 40S ACROSS THE NORTHERN PORTION OF THE
CWA. CONFIDENCE BEYOND THIS PERIOD IS LOW.
ON TUESDAY NIGHT AN UPPER LEVEL TROUGH WILL MOVE ACROSS SOUTHERN
CANADA AND CAUSE A SURFACE LOW TO DEVELOP...WITH A TRAILING COLD
FRONT FORECAST TO MOVE THROUGH THE REGION ON WEDNESDAY. THE GEM AND
ECMWF ARE FASTER WITH THIS FRONT THAN THE GFS. ALSO THE ECMWF HAS
POST FRONTAL PRECIP DRIVEN BY THE MID LEVEL FGEN...WHEREAS THE GFS
KEEPS THE PRECIP CONFINED TO THE DAKOTAS. HAVE DECIDED TO KEEP POPS
FOR WEDNESDAY NIGHT THROUGH FRIDAY DUE TO THE HIGH UNCERTAINTY IN
THE FORECAST. AS MENTIONED EARLIER...THE POLAR JET WILL BE OVER
SOUTHERN CANADA...WHILE THE SOUTHERN STREAM DIGS A TROUGH OVER THE
DESERT SOUTHWEST. HOW THESE TWO FEATURES PHASE ACROSS THE MIDWEST
WILL DETERMINE IF SIGNIFICANT SNOW DEVELOPS TOWARD THE END OF THE
WEEK...AS INDICATED BY THE GFS AND GEM...OR IF THE COLD ARCTIC
HIGH PRESSURE KEEPS THE REGION DRY AND COOL. FOR NOW DID NOT
HAVE THE CONFIDENCE TO LEAN TOWARDS ANY PARTICULAR SOLUTION...SO
STUCK WITH THE 20POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 623 AM CST SUN NOV 17 2013
STRATUS CLOUDS ASSOCIATED WITH THE AREA OF LOW PRESSURE MOVING
FROM NORTHEASTERN MN TOWARD THE GREAT LAKES WILL PLAGUE THE TAF
SITES THIS MORNING...WITH SUB-1000FT CIGS AND AREAS OF BR WITH
MVFR VSBYS. THE RAP 0.5KM AGL CONDENSATIONAL PRESSURE DEFICIT PROG
HAS BEEN REFLECTING THE ACTUAL TRENDS FAIRLY WELL...AND INDICATES
A FEW BREAKS IN THE LOW CLOUDS DEVELOPING EVENTUALLY TODAY
/ESPECIALLY FROM NEAR KRWF TO NEAR OR JUST SOUTH OF KMSP/...AROUND
21Z. HAVE THEREFORE INCLUDED SLIGHT IMPROVEMENTS IN CIGS FOR THIS
AFTERNOON. PRECIPITATION IS EXPECTED TO FALL MOSTLY SOUTHEAST OF THE
TAF SITES...ALTHOUGH LIGHT RAIN MAY SCRAPE KEAU DURING THE LATE
MORNING AND EARLY AFTERNOON HOURS. WINDS WILL BECOME GUSTY FROM
THE NORTHWEST...NEARING SUSTAINED SPEEDS OF 20 KTS WITH GUSTS TO
30 KTS. SUBSTANTIAL SCOURING OUT OF THE LOW CLOUDS DOES NOT APPEAR
AS IF ITS GOING TO HAPPEN UNTIL LATE TONIGHT AND MONDAY MORNING.
KMSP...
EXPECT CIGS TO PERSIST THROUGH THE MORNING...WITH MVFR VSBYS
LIKELY AS WELL. VSBYS SHOULD IMPROVE TO VFR BY 18Z...WITH SOME
IMPROVEMENT IN CIGS TO MVFR EXPECTED AROUND/AFTER 18Z. VFR
CONDITIONS ARE EXPECTED TO DEVELOP OVERNIGHT...WITH MOSTLY CLEAR
SKIES BY DAYBREAK MONDAY. SOUTHWEST WINDS SHIFT TO 290-300 DEGREES
BY 18Z AND INCREASE TO SUSTAINED 15-18KT SPEEDS WITH GUSTS TO AROUND 25
KTS. WINDS DECREASE A TAD THIS EVE...BUT ARE EXPECTED TO CONTINUE
GUSTING TO NEARLY 25 KTS THROUGH MUCH OF TONIGHT.
/OUTLOOK FOR KMSP/
MON...MVFR CIGS EARLY...THEN VFR. WINDS WNW AT 10G15KTS.
TUE...VFR. WINDS SE AT 10-15KTS.
WED...VFR WITH MVFR AND -RA LATE. WINDS SSW AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...LS
LONG TERM...JRB
AVIATION...LS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1134 PM CST SAT NOV 16 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 240 PM CST SAT NOV 16 2013
FIRST WAVE OF -RA/-DZ...AND EVEN A FEW THUNDERSTORMS THAT DEVELOPED
ALONG THE LEADING EDGE OF THE STRONG VERTICAL LIFT ACROSS EC/SC MN
EARLIER THIS AFTN. VISIBLE SATELLITE IMAGERY THIS AFTN INDICATED THE
DRIER AIR MOVING ACROSS NW IOWA WHICH WILL IMPACT FAR SOUTHERN MN
THIS EVENING. SOME BREAKS IN THE CLD CVR ARE LIKELY WITH THIS AREA
OF DRIER AIR...BUT HOW FAR NORTH THIS CLEARING DEVELOPS REMAINS
UNCERTAIN. LATEST RAP HAS AREAS SOUTH OF HWY 212 REMAINING NEARLY
SATURATED BLW 2K THRU TONIGHT.
DEEP SFC LOW IN NE SD WILL SLOWLY MOVE ENE ACROSS CENTRAL MN THIS
EVENING...AND THEN ACROSS NE MN BY SUNDAY MORNING. THIS WILL KEEP
MOST OF CENTRAL MN IN A WEAK FLOW IN THE BOUNDARY LAYER AND
THEREFORE KEEPING LOW CLDS/FOG AND OCCASIONAL DRIZZLE IN THE
FORECAST. NEXT SHRTWV OF INTEREST WILL IMPACT MAINLY THE SE CWA
WITH -RA SUNDAY MORNING...INTO THE EARLY AFTN. FURTHER TO THE
NW...THERE REMAINS ENOUGH ENERGY TO KEEP LOW POPS OVERNIGHT...BUT
WITH CAA ANY PRECIPITATION AMTS WILL REMAIN LIGHT. SOME
-SN/FLURRIES ARE POSSIBLE SUNDAY AFTN BEFORE ANY LEFTOVER
PRECIPITATION ENDS ACROSS CENTRAL MN...BUT NOT CONFIDENT ENOUGH TO
INCLUDE IN THIS FORECAST PACKAGE. TEMPS MAY BE A BIT LOWER IN FAR
SOUTHERN MN IF SKIES CLR. THE LOW CLDS/FOG AND DRIZZLE WILL KEEP
THE REST OF THE CWA WITH LITTLE TEMP CHG UNTIL SUNDAY AS WINDS
SHIFT TO THE W/NW AND BEGIN TO GUST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 240 PM CST SAT NOV 16 2013
DRIER AIR SHOULD FOLLOW THE FROPA QUICKLY SUNDAY NIGHT WITH
CLEARING SKIES INTO MONDAY. MODELS CONTINUE TO ADVERTISE A
SIDESWIPING OF THE TROUGH MONDAY BEFORE IMPRESSIVE RIDGING
RETURNS TUESDAY AND WEDNESDAY. INCREASED TEMPS A DEGREE OR TWO
MONDAY AND MONDAY NIGHT...BUT SEVERAL DEGREES TUESDAY AS 925 MB
TEMPS OF +4C TO +8C PUSH INTO THE CWA. MIXING TO THAT LEVEL WOULD
YIELD HIGHS IN THE MID/UPPER 50S OVER SOUTHERN MN AND UPPER 40S
OVER WRN WI. DID NOT QUITE GO THAT HIGH YET SINCE THIS IS A
RELATIVELY NEW MODEL TREND...BUT EACH OF THE LAST SEVERAL RUNS
HAVE BEEN GETTING PROGRESSIVELY WARMER.
MODEL CONSISTENCY HAS IMPROVED TODAY WITH A DRY COLD FRONT
PROGGED TO PUSH THROUGH LATE WEDNESDAY OR WEDNESDAY NIGHT. THERMAL
RIDGING IN ADVANCE OF THE FRONT WILL KEEP TEMPERATURES MILD
TUESDAY NIGHT AND WEDNESDAY. A 1040 MB HIGH WILL BUILD IN BEHIND
THE FRONT...BUT MODELS DIFFER A BIT WHERE THIS WILL TRACK WHICH
WILL DETERMINE THE DEGREE OF COLD AIR LATE NEXT WEEK.
AN INVERTED TROUGH PUSHING THROUGH THURSDAY NIGHT OR FRIDAY MAY
BRING A COATING OF SNOW TO THE REGION. INTRODUCED LOW POPS FOR NOW
DURING THIS PERIOD.
AN INTERESTING DEVELOPMENT HAS EMERGED ON THE 12Z ECMWF AND
CANADIAN FOR NEXT WEEKEND. FOLLOWING THE INVERTED TROUGH...A
PROLIFIC 1050-1055MB HIGH BUILDING INTO THE NORTHERN
ROCKIES/NORTHWESTERN PLAINS COULD BRING OUR FIRST SHOT AT VERY
COLD TEMPERATURES. HOWEVER...THE GFS AND FIM MAINTAIN A MUCH
MILDER SOLUTION WITH A WEAKER AND MORE PROGRESSIVE HIGH REMAINING
IN CANADA SO CANNOT TREND TOWARD EITHER SOLUTION YET.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1058 PM CST SAT NOV 16 2013
LOW PRES SHIFTING FROM THE ERN DAKOTAS INTO N-CENTRAL MN AND IT/S
ASSOCIATED MOISTURE PROFILES ARE MAKING FOR A TRICKY TAF SET
TONIGHT. THE OVERALL SCHEME LOOKS TO HAVE KAXN-KSTC SOCKED IN WITH
LIFR FOG AND LOW CEILINGS...WHILE THE REMAINING TAF SITES WILL
REMAIN MVFR TO VFR OVERNIGHT WITH PREVAILING S TO SW WINDS. THIS
AREA OF LOW PRES WILL REACH NE MN BY DAYBREAK...SPREADING THE
DEGRADED CONDS INTO CENTRAL MN...POSSIBLY AFFECTING KMSP ARND 12Z.
CEILINGS DROP INTO MVFR RANGE FOR MOST SITES ARND DAYBREAK...BUT
THE ERN TAF SITES WILL BE MORE SUSCEPTIBLE TO NOT ONLY THE
DEGRADED CONDS BUT ALSO ADDITIONAL ROUNDS OF -RA AS A SECONDARY
LOW PRES CENTER EJECTS FROM THE CENTRAL PLAINS TWD NRN IA/IL. AS
THIS SECONDARY LOW PRES CENTER SHIFTS E...CONDS WILL IMPROVE SUN
AFTN/EVE. HOWEVER...MODELS INDICATE THAT SUBSIDENCE ON THE
BACKSIDE OF THE SECONDARY LOW WITHIN STILL A FAIRLY DEEP MOISTURE
COLUMN WILL RESULT IN MVFR CIGS TMRW NIGHT SO HAVE ADVERTISED AS
SUCH AT ALL SITES. WINDS STILL LOOK TO TAKE A SIGNIFICANT SHIFT
FROM SW TO NW DURG THE DAY TMRW AND WILL SHOW A STRONG INCRS IN
SPEED...APPROACHING 20G30KT. SPEEDS WILL DECRS ONLY SLIGHTLY FOR
TMRW NIGHT...MAKING 15G25KT SPEEDS COMMON SUN NIGHT INTO MON MRNG.
KMSP...CONDS HAVE IMPROVED SIGNIFICANTLY OVER THE PAST 6 HOURS AND
BOTH OBSERVATIONAL TRENDS AND MODELS INDICATE THE THE IMPROVEMENT
WILL LAST THRU MUCH OF THE OVERNIGHT HOURS. CEILINGS DO LOOK TO
DROP BACK INTO MVFR RANGE DURG THE PRE-DAWN HRS BUT IFR CONDS LOOK
MUCH LESS LIKELY. CONDS DROP FURTHER ARND DAYBREAK WITH A MINOR
INVERSION DEVELOPING BUT SUCH CONDITIONS WILL HAVE A SHORT
DURATION AS -RA MOVES IN FROM THE SE AND HELPS SCOUR OUT LOWER
VSBY AND POSSIBLY CEILINGS AS WELL. CONDS THEN CONTINUE TO IMPROVE
AS THE SECONDARY LOW PRES CENTER SHIFTS AWAY...MAKING FOR
STRONG/GUSTY NW WINDS AND CEILINGS EVENTUALLY REACHING VFR.
HOWEVER...ANOTHER ROUND OF MVFR CEILINGS LOOKS FAIRLY LIKELY SUN
NIGHT INTO MON MRNG BEHIND THE DEPARTING SYSTEM.
/OUTLOOK FOR KMSP/
MON...MVFR CIGS EARLY. THEN VFR. WINDS WNW AT 10G15KTS.
TUE...VFR. WINDS SE AT 10KTS.
WED...VFR WITH MVFR AND -RA LATE. WINDS SSW AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...BORGHOFF
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1234 PM CST SUN NOV 17 2013
.UPDATE...
ISSUED AT 1233 PM CST SUN NOV 17 2013
WINDS HAVE STARTED TO INCREASE MORE THAN EXPECTED ESPECIALLY IN
NORTH CENTRAL KANSAS. THE LATEST HRRR INDICATES THE STRONGEST
WINDS WILL BE EARLY THIS AFTERNOON IN NORTH CENTRAL KANSAS. HAVE
ISSUED A HIGH WIND WARNING FOR THIS AREA. WINDS CONTINUE TO BE
GUSTY ACROSS THE REMAINDER OF THE AREA AND WILL CONTINUE THE WIND
ADVISORY FOR NEBRASKA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CST SUN NOV 17 2013
FOCUS IS ON A PERIOD OF INTENSE WINDS TODAY AND CRITICAL FIRE
WEATHER CONDITIONS.
SPRINKLES OR A BANDED AREA OF VERY LIGHT RAIN DEVELOPED DURING
THE PRE DAWN HOURS IN PRESENCE OF MID LEVEL FRONTOGENESIS AND
DYNAMICS AS A LEAD SHORTWAVE TROUGH CROSSES NEB AND A COLD FRONTAL
BOUNDARY WORKS EAST/SOUTHEAST. LIFT IS FOCUSED MAINLY NORTH OF
INTERSTATE 80 AND MAY LINGER JUST BEYOND 12Z IN OUR EASTERN ZONES.
SFC COLD FRONT WILL CLEAR OUR CWA BY DAYBREAK WITH A STRONGER
SHORTWAVE TROUGH CROSSING THE NORTHERN/CENTRAL PLAINS MID/LATE
MORNING WITH A SECONDARY COLD FRONT AND COOLER AIR MAKING A PUSH
SOUTHEASTWARD BY MIDDAY...AND THE MID LEVEL THERMAL TROUGH SWEEPS
SOUTHEAST TOWARD THE MISSOURI RIVER BY LATE AFTN. 3HR PRESSURE
RISES BEHIND THE INITIAL FRONT BY DAYBREAK AVERAGE NEAR 7MB ACROSS
PORTIONS OF CENTRAL/EASTERN KANSAS...THEN AVERAGE 4 TO 6MB ACROSS
CENTRAL/EASTERN NEB BEHIND SECONDARY BOUNDARY THIS AFTN. IN A TIGHT
PRESSURE GRADIENT BEHIND THE BOUNDARIES...AN INTENSE PERIOD OF
NORTHWEST WINDS ARE EXPECTED BEGINNING AROUND MID
MORNING...PEAKING AROUND MID DAY OR EARLY AFTERNOON...THEN
SUBSIDING IN THE EVENING AS THE SYSTEM DEPARTS AND GRADIENT
RELAXES. MODEL FORECAST SOUNDINGS SUGGEST THE DEEPEST MIXING WILL
OCCUR ACROSS OUR SOUTHERN/SOUTHWEST ZONES WHERE MIXING WILL REACH
JUST ABOVE H8. WINDS AT THE TOP OF THE LAYER ARE NEAR 50KTS IN NC
KANSAS AROUND MID DAY THEN DECREASE THE AROUND 35KTS BY MID/LATE
AFTN. FARTHER NORTH ACROSS OUR NORTHERN ZONES MIXING IS BETWEEN H8
AND H85 WITH WINDS AT THE TOP OF THE LAYER AVERAGING 35 TO 40KTS.
IN ANY CASE...VERY WINDY CONDITIONS WILL DEVELOP TODAY AND CURRENT
WIND ADVISORY HEADLINE REMAINS ON TRACK. HAVE SOME CONCERNS THAT
PORTIONS OF NC KANSAS TOWARDS THE RUSSEL AREA MAY NEAR OR REACH
HIGH WIND WARNING CRITERIA AND THIS WILL NEED TO BE MONITORED
CLOSELY.
SHORT TERM MODELS INDICATE THE PRESENCE OF MID LEVEL MOISTURE ACROSS
OUR NORTHEAST ZONES TODAY AND PLACE CONVECTIVE TEMPS IN THE UPPER
40S TO AROUND 50F...WHICH ARE AROUND FORECAST HIGHS FOR TODAY.
CONFIDENCE IS NOT HIGH ON THE DEGREE OF CLOUD COVER IN THIS
AREA...BUT DID GO WITH AT LEAST PARTLY CLOUDY CONDITIONS. AS FAR
AS TEMPERATURES GO...WE WILL BE ON A DOWNWARD TREND COMPARED TO
THE MILD CONDITIONS ON SATURDAY WITH HIGHS TODAY AVERAGING IN THE
50S.
THE COLDER AIRMASS WILL BE MORE NOTICEABLE TONIGHT IN GOOD
RADIATIONAL CONDITIONS. A SURFACE RIDGE AXIS SETTLES ONTO THE
PLAINS AND WINDS DROP OFF...SKIES CLEAR AND VERY DRY DPS FM THE
TEENS TO LOW 20S WILL BE IN PLACE. HAVE TARGETED LOWS FROM THE
TEENS IN THE RIVER VALLEYS IN OUR WESTERN ZONES...TO THE LOW/MID
20S IN THE EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 307 AM CST SUN NOV 17 2013
ALOFT: HEIGHTS WILL BE RISING MON IN THE WAKE OF THE STORM EXITING
THE REGION TODAY...WITH A BROAD LOW-AMPLITUDE RIDGE ENVELOPING THE
CNTRL USA. AS THE WEEK PROGRESSES...SPLIT FLOW WILL EVOLVE WITH GOOD
MODEL AGREEMENT ON THE NRN STREAM /ALONG THE US-CANADA BORDER/
DELIVERING ANOTHER COLD AIR MASS TO THE REGION. MEANWHILE...A TROF
WILL MOVE INTO THE DESERT SW LATE WED AND CLOSE OFF INTO A CUT-OFF
LOW AS THE WAVELENGTH SHORTENS AND HIGHER LATITUDE AMPLIFICATION
OCCURS. HEIGHTS WILL THEN BUILD DOWNSTREAM OVER THE SRN PLAINS AND
SE...RESULTING IN CONFLUENT FLOW OVER THE ERN HALF OF THE CONUS.
SURFACE: HIGH PRES WILL BE OVERHEAD AT DAWN MON. THIS HIGH WILL
DEPART INTO THE ERN USA TUE. THE FCST AREA WILL BE IN THE WARM
SECTOR OF LOW PRES ADVANCING E ALONG THE US-CANADA BORDER TUE. THE
ASSOCIATED COLD FRONT WILL SURGE S...CROSSING THE FCST AREA WED
AFTERNOON. THE CONSISTENCY OF THE PAST SEVERAL RUNS OF THE EC IS
PREFERRED AND ITS ENSEMBLE MEAN IS SUPPORTIVE. THE 00Z GEM IS ALSO
ON BOARD. THE 18Z/00Z GFS HAVE TRENDED FASTER VS 24 HRS AGO...BUT
THEY ARE STILL LAGGING. STRONG AND COLD HIGH PRES WILL SETTLE OVER
THE PLAINS THU. FRI THE HIGH WILL DEPART FOR THE GREAT LAKES AS A
CLIPPER RACES ACROSS SRN CANADA. THIS SYSTEM WILL DELIVER A
REINFORCING COLD SHOT AND HIGH PRES...BUT THE CORE OF THE COLDEST
AIR WILL HEAD INTO THE ERN USA.
THE 142 AM AND 11 AM/SAT EXTENDED FCST DISCUSSIONS FROM WPC WERE
REVIEWED FOR INCLUSION INTO THE FCST AND SUPPORT THE ABOVE SCENARIOS.
ENJOY THE FIRST FEW DAYS THIS WEEK BECAUSE THE EXTENDED FCST AND
BEYOND IS LOOKING COLD. THE WEEK WILL START WITH MILD /WARMER THAN
NORMAL/ TEMPS. THAT WILL END THU AS ARCTIC AIR SURGES S. THE EC
ENSEMBLE MEAN AND CFSV2 TEMP ANOMALIES SUGGEST TEMPS THEN AVERAGE AT
OR BELOW NORMAL TO FINISH OUT THE MONTH. THAT DOESN/T MEAN WE WON/T
HAVE A DAY HERE OR THERE OF ABOVE NORMAL WARMTH. BUT OVERALL...THE
AVERAGE SHOULD BE COLDER.
OVERALL CHANCE FOR PRECIP ARE NIL UNTIL THU NIGHT OR FRI. GFS
ENSEMBLE PROBABILITIES FOR .10" INCREASE TO 60+ PERCENT WITH A 40-50
PERCENT CHANCE OF .25" AND 15 PERCENT FOR .50". A LITTLE OVER HALF
OF THE EC ENSEMBLE MEMBERS OFFER ANYWHERE FROM .10" TO .50".
HAZARDS: FOR NOW NOTHING SPECIFIC. HOWEVER...WE CONTINUE TO SEE
HINTS OF THE CUT-OFF LOW EJECTING SHORTWAVE TROFS THAT COULD RESULT
IN A SOME LIGHT PRECIP OF THE WINTRY VARIETY IN THE THU-FRI
TIMEFRAME.
THE DAILY DETAILS...
MON: A COLD/FROSTY START. SUNNY AND TEMPS WILL REBOUND NICELY.
TUE: INCREASING MID-HIGH CLOUDS. BELIEVE WE HAVE THIS BETTER
DEPICTED VS 24 HRS AGO. BREEZY S WINDS WILL GUST TO 25-30 MPH.
WED: DRY AFTERNOON COLD FRONTAL PASSAGE. PARTLY SUNNY WITH
MULTI-LAYERED MID-HIGH CLOUDS. WINDS SHOULD BE FAIRLY LIGHT UNTIL
FRONTAL PASSAGE...THEN THEY SHOULD CRANK IT UP FROM THE N.
THU: PROBABLY CLOUDY VIA GEM/EC/GFS CROSS SECTIONS. TEMPS MAY RISE
VERY LITTLE FROM MORNING LOWS. HIGH IN THE 30S LOOK PLAUSIBLE AND
ORD-GREELEY MAY NOT REACH 30F.
FRI-SAT: UNCERTAIN. BUT CONFLUENT FLOW ALOFT WILL RESULT IN A VERY
STRONG UPPER-LEVEL JET CORE /140 KTS/ OVER THE OH VALLEY. THIS WILL
PUT US IN THE RIGHT ENTRANCE REGION. THE IMPORTANT QUESTION IS
MOISTURE AND IF IT/S FAR ENOUGH N. BOTH THE GFS AND EC HAVE IT THU
NIGHT AND THEN PUSH IT S OF THE FCST AREA FRI WITH THE POSSIBILITY
OF IMPROVING WX SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1122 AM CST SUN NOV 17 2013
WINDS WILL BE THE PRIMARY CONCERN THROUGH THE AFTERNOON. EXPECT
GUSTY NORTHWEST WINDS TO CONTINUE THROUGH AROUND SUNSET. WINDS
WILL GRADUALLY BECOME LIGHT DURING THE NIGHT. A FEW MID LEVEL
CLOUDS WILL MOVE THROUGH THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 307 AM CST SUN NOV 17 2013
A RED FLAG WARNING REMAINS IN EFFECT TODAY FOR ALL OF NORTH
CENTRAL KANSAS AND LOCATIONS WEST OF A LINE FROM LEXINGTON TO
FRANKLIN IN SOUTH CENTRAL NEBRASKA. INTENSE NORTHWEST WINDS ARE
FORECAST TODAY IN DEEP MIXING BEHIND A COLD FRONTAL BOUNDARY.
THE INTENSE WINDS WILL DEVELOP MID TO LATE MORNING AND REMAIN
STRONG THIS AFTN BEFORE SUBSIDING IN THE EVENING. DRY AIRMASS
ADVECTS SOUTHEAST AND LOW RELATIVE HUMIDITY VALUES WILL DROP NEAR
OR BELOW 20 PERCENT IN THE RED FLAG WARNING AREA.
THIS BEING SAID...LATEST MODEL RUNS HAVE TRENDED HIGHER WITH DPS/RH
LEVELS ACROSS PORTIONS OF SOUTH CENTRAL NEBRASKA...NAMELY
DAWSON...GOSPER AND PHELPS COUNTIES. CONDITIONS ACROSS NORTH
CENTRAL KANSAS PARTICULARLY PHILLIPS AND ROOKS COUNTIES STAND TO
SEE THE MOST CRITICAL FIRE DANGER CONDITIONS WHERE DPS IN THE
SINGLE DIGITS ARE FORECAST...RESULTING IN LOW RELATIVE HUMIDITY
VALUES AROUND 15 PERCENT. THE LOCATION OF CURRENT RED FLAG WARNING
WILL REMAIN AS IS WITH A BUFFER SURROUNDING OUR FAR SW ZONES WHERE
CONDITIONS WILL BE MOST CRITICAL. HOWEVER...IF TEMPS TREND UP AND
LOWER DPS MATERIALIZE FARTHER EAST THAN WHAT CURRENT MODELS
SHOW...THEN HEADLINE MAY NEED TO BE EXPANDED.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>049-
060>064-072>077-082>087.
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ060-072-073-
082>084.
KS...RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ005>007-
017>019.
HIGH WIND WARNING UNTIL 3 PM CST THIS AFTERNOON FOR KSZ005>007-
017>019.
&&
$$
UPDATE...JCB
SHORT TERM...FAY
LONG TERM...HALBLAUB
AVIATION...JCB
FIRE WEATHER...FAY
AREA FORECAST DISCUSSION
NWS BUFFALO NY
729 AM EST SUN NOV 17 2013
.SYNOPSIS...
LOW PRESSURE WILL RAPIDLY STRENGTHEN ACROSS THE UPPER LAKES
TODAY...WHICH WILL SWEEP A POWERFUL COLD FRONT ACROSS OUR REGION
TONIGHT. AHEAD OF THE FRONT WILL BE WARM TEMPERATURES AND SOME
SHOWERS...WITH A LINE OF SEVERE THUNDERSTORMS POSSIBLE ALONG THE
FRONT TONIGHT. THERE WILL ALSO BE GUSTY WINDS AHEAD OF THE FRONT AND
MORE WIDESPREAD STRONG WINDS BEHIND THE FRONT. THE FRONT WILL
EVENTUALLY USHER IN COOLER TEMPERATURES MONDAY NIGHT THROUGH
TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOW PRESSURE DEVELOPING ACROSS MINNESOTA THIS MORNING WILL
RAPIDLY INTENSIFY AS IT LIFTS ACROSS THE UPPER LAKES TODAY. THE
INTENSE LOW WILL CLOSE OFF ALOFT SOUTH OF HUDSON BAY AS IT SWEEPS
A STRONG COLD FRONT ACROSS WESTERN NEW YORK TONIGHT. THIS WILL
BRING STRONG SYNOPTIC WINDS TO SOME LOCATIONS...AND POSSIBLY SOME
SEVERE WEATHER WITH THE FRONTAL PASSAGE. NOW FOR THE DETAILS...
TODAY WILL GET OFF TO A WARM START...WITH MORNING TEMPERATURES
ALREADY IN THE 50S IN MANY LOCATIONS. TEMPERATURES RISE INTO THE
UPPER 50S ACROSS HIGHER TERRAIN AND INTO THE MID 60S IN DOWNSLOPE
REGIONS NORTH OF I-90. AN AREA OF SHOWERS HAS DEVELOPED WELL
AHEAD OF THE COLD FRONT IN THE OHIO VALLEY. MUCH OF THE SUPPORT
FOR THESE SHOWERS IS FROM THE COMBINATION OF UPPER LEVEL LIFT AND
MOISTURE ADVECTION WITH THE DEVELOPING LLJ. SHOWERS WILL
GRADUALLY WEAKEN AS THE SSW FLOW LIFTS THEM AHEAD OF SYNOPTIC
SUPPORT AND INTO OUR REGION THIS MORNING. THIS WILL BRING A PERIOD OF
SHOWERS TO MOST THIS MORNING...BUT HIGH RESOLUTION MODEL GUIDANCE (00/06Z
NAM/RGEM/HRRR) HAS BEEN FAIRLY CONSISTENT IN FORECASTING A BREAK
BETWEEN THIS INITIAL ROUND AND COLD FRONT. WITH SUPPORT FROM IR
SATELLITE TRENDS..EXPECT MOST AREAS WILL GET A BREAK FROM THE
SHOWERS THIS AFTERNOON...WITH JUST WARM AND BREEZY CONDITIONS UNTIL
THE NEXT ROUND OF SHOWERS MOVES IN FROM THE SOUTHWEST LATE
AFTERNOON. WINDS WILL BE GUSTY TODAY DUE TO A 45 KNOT FLOW ALOFT.
FOR THE MOST PART...THIS WILL NOT MIX DOWN TO THE SURFACE...EXCEPT
ALONG THE CHAUTAUQUA RIDGE AND BLACK RIVER VALLEY WHERE GUSTS TO
40 MPH ARE LIKELY. THIS SAID...EXPECT DAMAGING WINDS TO HOLD OFF
UNTIL THIS EVENING WHEN WINDS ALOFT INCREASE.
NEARLY ALL LOCATIONS WILL EXPERIENCE STRONG WINDS AT SOME POINT
TONIGHT. ALTHOUGH THE TRACK OF THE LOW IS A BIT NW OF THE
TYPICALLY FAVORED TRACK FOR HIGH WINDS IN OUR REGION...THE SHEAR
INTENSITY OF THE 970MB LOW AS IT CLOSES OFF ALOFT SUPPORTS A
SIGNIFICANT WIND DAMAGE THREAT FOR OUR REGION. THE FIRST ISSUE
WILL BE THE INCREASING LOW LEVEL JET OUT AHEAD OF THE FRONT...WITH
BUFKIT FOR THE GFS/NAM/SREF ENSEMBLE SUPPORTING A PREFRONTAL LLJ
OF 65 KTS AT 925MB. WHILE THIS IS NOT EXPECTED TO MIX TO THE
SURFACE IN MOST LOCATIONS...EXPECT DAMAGING GUSTS WILL MIX OFF THE
CHAUTAUQUA RIDGE AND BLACK RIVER VALLEY. BECAUSE OF
THIS...THE HIGH WIND WARNING NOW ALSO INCLUDES LEWIS AND JEFFERSON
COUNTIES. ELSEWHERE THE CONFIDENCE IN SYNOPTIC DAMAGING WINDS IS
LOWER. THE BIG QUESTION WILL BE TO WHAT EXTENT WINDS MIX ACROSS
HIGHER TERRAIN. GIVEN THE POTENTIAL FOR 60 MPH WINDS STILL
EXISTS...HAVE KEPT THE HIGH WIND WATCH IN PLACE. HOWEVER...00Z/06Z
GUIDANCE SEEMS TO SUGGEST MORE OF AN ADVISORY TYPE EVENT ACROSS
INTERIOR SECTIONS. THIS WILL CONTINUE TO BE MONITORED...WITH
FUTURE TRENDS IN THE STRENGTH OF THE LLJ KEY TO THIS HEADLINE
DECISION.
IN ADDITION TO SYNOPTIC WINDS...PRECIPITATION ALONG THE FRONT ITSELF
MAY MIX STRONG WINDS ALOFT AND RESULT IN CONVECTIVELY DRIVEN
DAMAGING WINDS. THERE ALSO MAY BE A TEMPORARY BURST IN WINDS
IMMEDIATELY BEHIND THE FRONT AS A STRONG SHORTWAVE PIVOTS AROUND THE
RAPIDLY DEEPENING LOW. BECAUSE OF THIS...SPC HAS WESTERN NEW YORK IN
A SLIGHT RISK FOR SEVERE WEATHER...WITH DAMAGING WINDS THE MAIN
THREAT. THE FRONT WILL ENTER WESTERN NEW YORK THIS EVENING...AND
QUICKLY SWEEP ACROSS THE REGION DURING THE EARLY MORNING HOURS.
FORECAST HEDGES ON THE FASTER SIDE OF MOST GUIDANCE...WITH THE
FRONT LIKELY TO ACCELERATE SIMILAR TO THE HRRR FORECAST.
SHOWERS SHOULD END QUICKLY FROM WEST TO EAST...WITH THE ATMOSPHERE
BRIEFLY DRYING OUT IMMEDIATELY BEHIND THE FRONT. TEMPERATURES WILL
QUICKLY COOL INTO THE 40S BEHIND THE FRONT. WINDY CONDITIONS WILL
CONTINUE...WITH WEAKER WINDS ALOFT BEING OFFSET BY BETTER MIXING
IN THE COLD AIR ADVECTION.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
THIS TIME PERIOD WILL TRANSITION FROM THE MILD AND POTENTIAL
SEVERE/WINDY WEATHER TO MORE WINTRY.
BY 12Z MONDAY THE COLD FRONT AND ITS ASSOCIATED PRECIPITATION WILL
BE EAST OF THE REGION. THE SURFACE LOW...THAT NOW WILL BE ENTERING
INTO AND CROSSING QUEBEC WILL CONTINUE TO DEEPEN MONDAY MORNING
BENEATH A NEGATIVELY TILTED UPPER LEVEL TROUGH. WINDS AROUND THIS
AREA OF LOW PRESSURE WILL BRING MUCH COLDER AIR ALOFT ACROSS OUR
REGION WHICH WILL AID IN MIXING STRONGER WIND GUSTS DOWN TO THE
SURFACE. ALSO A STRONG PRESSURE GRADIENT ORIGINATING FROM THIS DEEP
AREA OF LOW PRESSURE IN ADDITION TO GOOD PRESSURE RISES BEHIND THE
FRONT WILL CONTINUE TO BRING GUSTY TO STRONG WINDS ACROSS THE
REGION. STRONGEST WINDS...ONES THAT WILL NEAR 60 MPH WILL BE FOUND
DOWNWIND OF LAKE ERIE AND INLAND TOWARDS MONROE COUNTY...AND ALSO
ACROSS THE NORTH COUNTRY AND THE SAINT LAWRENCE VALLEY. FARTHER
INLAND ACROSS THE SOUTHERN TIER AND UPPER GENESEE VALLEY AND FINGER
LAKES REGION WILL LEAVE THE HIGH WIND WATCH IN EFFECT...AS WIND
GUSTS MAY REMAIN WITHIN ADVISORY LEVEL CRITERIA.
BEHIND THE COLD FRONT 850 HPA TEMPERATURES WILL DROP TO AROUND -6C
OVER THE LAKES MONDAY...WHICH WITH THE +8C OR SO LAKES WILL LIKELY
BRING LAKE EFFECT RAIN SHOWERS THROUGH THE DAY MONDAY. WITH A STILL
WSW WIND LIGHT BANDS OF RAIN WILL LIKELY BE JUST TO THE SOUTH OF
BUFFALO...AND ACROSS WATERTOWN AND TOWARDS THE SAINT LAWRENCE RIVER
MONDAY MORNING. AS THE COLD AIR DEEPENS AND WINDS VEER AROUND TO
WEST...AND THEN NORTHWEST THESE BANDS OF LAKE EFFECT SHOWERS WILL
DROP SOUTHWARD. MODEL SOUNDINGS SUGGEST THAT PRECIPITATION WILL STAY
MAINLY RAIN THROUGH THE DAY...AND THEN AS THE COLDER AIR DEEPENS TO
AROUND -8 TO -10C MONDAY NIGHT PRECIPITATION WILL CHANGE OVER TO
LAKE EFFECT SNOW SHOWERS.
ONE CONCERN FOR LATER MONDAY NIGHT IS DEPTH OF THE MOISTURE WILL BE
BELOW THE GOOD SNOW CRYSTAL GROWTH ZONE. THIS MAY ALLOW FOR SOME
FREEZING DRIZZLE TO DEVELOP LATER IN THE NIGHT. THIS MINIMAL
MOISTURE IN THE SNOW GROWTH ZONES WILL ALSO HOLD ACCUMULATION TO THE
LIGHTER SIDE MONDAY NIGHT.
TUESDAY LAKE EFFECT PRECIPITATION WILL END THROUGH THE MORNING
HOURS AS TEMPERATURES BEGIN TO WARM ALOFT AND HIGH PRESSURE FUNNELS
SOME DRIER AIR ACROSS THE LAKES. THIS DRIER AIR WILL ALSO HELP TO
ERODE THE LOW CLOUDS AND ALLOW FOR SOME SUNSHINE THROUGH THE DAY.
THOUGH SOME SUNSHINE WILL DEVELOP...OUR HIGHS TUESDAY WILL ONLY
REACH INTO THE MID AND UPPER 30S...WHICH WILL BE A RETURN BACK TO
BELOW NORMAL TEMPERATURES. CLEARING SKIES TUESDAY NIGHT AND LIGHT
WINDS SHOULD BRING WIDESPREAD 20S AT NIGHT WITH A FEW OF THE COLDER
VALLEYS OF THE INLAND SOUTHERN TIER AND NORTH COUNTRY POSSIBLY
DROPPING INTO THE UPPER TEENS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
TRANQUIL WEATHER WILL CHARACTERIZE THE FIRST HALF OF THIS PERIOD AS
A BROAD SURFACE RIDGE BUILDS ACROSS THE GREAT LAKES AND NORTHEAST
PART OF THE COUNTRY.
THE SURFACE HIGH SHOULD BRING MOSTLY SUNNY SKIES WEDNESDAY AS IT
CRESTS OVER NEW YORK STATE NEW ENGLAND. AS THE HIGH SETTLES OFF THE
NEW ENGLAND COAST THURSDAY...THERE WILL BE SOME INCREASE IN CLOUDS
AS A COLD FRONT SHIFTS EAST TOWARD THE LOWER LAKES. THE FRONT WILL
BRING A CHANCE FOR RAIN AND SNOW SHOWERS...ACROSS THE LAKE ONTARIO
REGION THURSDAY AND THURSDAY NIGHT. A BETTER CHANCE WILL BE LATER
FRIDAY AND SATURDAY WHEN A STRONG COLD FRONT CROSSES THE REGION WITH
CHANCES FOR RAIN AND SNOW. WINDS WILL ALSO BECOME STRONGER BEHIND
THIS COLD FRONT TO START THE WEEKEND...THOUGH MODEL SOUNDINGS
SUGGEST THE LOW LEVEL JET WILL NOT BE AS STRONG AS THIS SUNDAY`S
EVENT.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AN AREA OF SHOWERS WILL MOVE FROM NORTHEASTER OHIO TO NORTHWESTERN
NEW YORK THROUGH THE MORNING HOURS. EXPECT THIS AREA TO EXIT EAST
OF LAKE ONTARIO EARLY AFTERNOON WHICH WILL PROBABLY PROVIDE A
BRIEF BREAK FOR MOST SITES DURING THE AFTERNOON HOURS. FOR THE
MOST PART...TAF LOCATIONS SHOULD STAY VFR TODAY...WITH THE
EXCEPTION OF THE SOUTHERN TIER (JHW) WHERE IFR/MVFR CIGS WILL
LIKELY PERSIST FOR MUCH OF THE DAY.
SOUTHERLY WINDS OF 40 TO 50 KTS WILL PERSIST THROUGH MOST OF THE
DAY. INITIALLY THIS WILL RESULT IN LLWS AT MOST TAF LOCATIONS SINCE
IT WILL NOT MIX DOWN...BUT SUSPECT PARTIAL MIXING TODAY TO DIMINISH
THE LLWS THIS AFTERNOON. DESPITE FAIRLY STRONG WINDS THIS
EVENING...WINDS ALOFT WILL BE SO STRONG THAT MORE LLWS IS LIKELY
WITH A 55-60 KNOT FLOW AT 2000 FEET.
A POWERFUL COLD FRONT WILL CROSS THE REGION FROM WEST TO EAST TONIGHT.
THIS FRONT COULD BE ACCOMPANIED BY A LINE OF THUNDERSTORMS CAPABLE
OF PRODUCING IFR/LOW MVFR CONDITIONS AND SURFACE WIND GUSTS TO 50
KNOTS. FOLLOWING THE FRONTAL PASSAGE...EXPECT WINDS TO VEER TO
SOUTHWESTERLY AND INCREASE...PRODUCING A MORE PROLONGED ROUND OF
40-50 KNOT WIND GUSTS THAT WILL LAST INTO MONDAY MORNING.
OTHERWISE...DRY WEATHER WILL RETURN FOLLOWING THE FROPA AS STRONG
DRY SLOTTING OVERSPREADS THE REGION ALOFT...THOUGH SOME MVFR TO
LOW VFR CIGS MAY LINGER.
OUTLOOK...
MONDAY...STRONG WINDS IN THE MORNING...OTHERWISE MVFR/VFR WITH A
CHANCE OF SHOWERS EAST OF THE LAKES IN THE AFTERNOON.
TUESDAY...VFR WITH LOCAL MVFR IN LIGHT LAKE EFFECT SNOW SHOWERS
SOUTHEAST OF THE LAKES.
WEDNESDAY AND THURSDAY...VFR.
&&
.MARINE...
SOUTHERLY WINDS WILL PERSIST TODAY...AND WILL BE GUSTY IN SOME
LOCATIONS...PARTICULARLY ON LAKE ERIE. THIS INCREASING SOUTHERLY
FLOW WILL ALSO BUILD WAVES ON EASTERN LAKE ONTARIO DUE TO THE
LONGER FETCH.
THE MAIN PERIOD OF CONCERN WILL BE THIS EVENING THROUGH MONDAY WHEN
GALE FORCE WINDS ARE A NEAR CERTAINTY ON BOTH LAKES. LOW PRESSURE
DEEPENING TO 970 MB SOUTH OF JAMES BAY LATE TONIGHT WILL PRODUCE A
PERIOD OF SOLID GALES ON THE LAKES TONIGHT AND MONDAY. IT WILL BE A
BIT MORE MARGINAL ON THE RIVERS...BUT THE SHEAR STRENGTH OF THE LOW
AND STRONG WINDS ALOFT JUSTIFY GALES ON THE RIVERS TOO.
WINDS WILL GRADUALLY DIMINISH MONDAY NIGHT AND TUESDAY AS THE FLOW
BECOMES NORTHWESTERLY.
&&
.TIDES/COASTAL FLOODING...
A RAPIDLY DEEPENING AREA OF LOW PRESSURE MOVING FROM THE CENTRAL
LAKES TOWARDS WESTERN QUEBEC WILL FOLLOW A FAVORABLE PATH TO
PRODUCE STRONG SOUTHWEST WINDS ON LAKE ERIE AND PUSH RISING WATER
TO THE NORTHEAST END OF THE LAKE.
WINDS WILL SHIFT FROM SOUTHERLY TO SOUTHWESTERLY FOLLOWING A
STRONG COLD FRONT LATE SUNDAY EVENING. NORMALLY THIS SCENARIO
GIVEN THE FORECAST WIND SPEEDS WOULD NOT ALLOW THE LAKE LEVEL TO
QUITE REACH FLOOD STAGE...WITH MODEL GUIDANCE SUGGESTING A PEAK
AROUND 5 FEET. BUT THERE IS THE POTENTIAL FOR A SQUALL LINE ALONG
THE COLD FRONT. SQUALL LINE DRIVEN SEICHE EVENTS ARE NOT AS COMMON
AS SYNOPTICALLY DRIVEN...BUT IF THE SQUALL LINE IS STRONG ENOUGH
IT MAY ENHANCE THE SEICHE AND PUSH THE WATER LEVEL AT BUFFALO TO
NEAR THE FLOOD STAGE OF 8 FEET ABOVE LOW WATER DATUM. CONFIDENCE
IN LAKESHORE FLOODING REMAINS MARGINAL GIVEN THE FAIRLY INFREQUENT
NATURE OF SIMILAR EVENTS. WITH THIS IN MIND...A LAKESHORE FLOOD
WATCH REMAINS IN EFFECT FOR TONIGHT INTO EARLY MONDAY MORNING.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 1 PM EST MONDAY
FOR NYZ019-085.
LAKESHORE FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING
FOR NYZ010-019-085.
HIGH WIND WARNING FROM 7 PM THIS EVENING TO 4 PM EST MONDAY
FOR NYZ007-008.
HIGH WIND WATCH FROM THIS EVENING THROUGH MONDAY AFTERNOON FOR
NYZ004>006.
HIGH WIND WARNING FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR NYZ001>003-010-011.
HIGH WIND WATCH FROM THIS EVENING THROUGH MONDAY AFTERNOON FOR
NYZ012>014-020-021.
MARINE...GALE WARNING FROM 7 PM THIS EVENING TO 4 PM EST MONDAY FOR
LEZ020-040-041.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
LEZ040-041.
GALE WARNING FROM 7 PM THIS EVENING TO 4 PM EST
MONDAY FOR LOZ030.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
LOZ043>045.
GALE WARNING FROM 7 PM THIS EVENING TO 7 PM EST MONDAY FOR
LOZ043>045-063>065.
GALE WARNING FROM 10 PM THIS EVENING TO 4 PM EST MONDAY
FOR LOZ042-062.
GALE WARNING FROM 1 AM TO 7 PM EST MONDAY FOR SLZ022-
024.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...THOMAS
LONG TERM...THOMAS/TJP
AVIATION...APFFEL/JJR
MARINE...APFFEL/THOMAS
TIDES/COASTAL FLOODING...HITCHCOCK/APFFEL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1238 PM EST SUN NOV 17 2013
.SYNOPSIS...
LOW PRESSURE OVER THE PLAINS STATES WILL DEEPEN RAPIDLY AS IT
MOVES NORTHEAST TODAY REACHING NORTHERN LAKE MICHIGAN BY THIS
EVENING AND INTO QUEBEC ON MONDAY. THIS WILL PUSH A STRONG COLD
FRONT ACROSS THE AREA THIS EVENING. HIGH PRESSURE WILL MOVE EAST
OUT OF THE SOUTHERN PLAINS STATES INTO THE OHIO VALLEY BY TUESDAY
AND THEN OFF THE EAST COAST ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REMOVED THUNDER ACROSS NORTH CENTRAL OHIO AND POINTS EAST UNTIL
VERY LATE AFTERNOON/EVENING. WHILE I CANNOT RULE OUT THUNDER...
WOULD LIKE TO MAKE THE THUNDER AND WIND WITH THE FRONT MORE OF THE
FOCAL POINT OF THE FORECAST. TOUGH TO DO IN THESE DAYS OF
AUTOMATED TEXT FORMATTERS...SO NOT SURE EXACTLY WHAT THE WORDING
WILL SAY. BETTER CHANCE FOR THUNDER AT ANY TIME IN THE DRY SLOT
THAT IS CREEPING ACROSS NORTHWEST OHIO. SORT OF LOOKS LIKE
OKLAHOMA IN THE SPRING TIME...HMMM.
NO OTHER SIGNIFICANT CHANGES TO THE FORECAST. DID NUDGE UP HIGH
TEMPERATURES A COUPLE OF DEGREES ACROSS NW OHIO AND PARTS OF NORTH
CENTRAL OHIO WHERE THERE WILL NOT BE AS MANY SHOWERS. RECORD HIGH
IN TOLEDO IS 71 AND WE WILL TAKE A RUN AT IT. 72 AT CLE IS
POTENTIALLY WITHIN REACH.
RELEVANT EARLY MORNING UPDATED DISCUSSION...
SHOWERS CONTINUE TO MOVE EAST AND OUT OF THE AREA AT THIS TIME.
CELLULAR CONVECTION CONTINUES TO MOVE INTO EXTREME NORTHWEST OHIO
AND SOUTHERN LOWER MICHIGAN. THE WATER VAPOR PLUME IS ALSO PUSHING
EAST ALLOWING FOR SOME DRIER AIR TO MOVE EAST AND ALLOW FOR A
BREAK IN THE ACTION. LATEST HRRR MODEL SHOWS MASSIVE SQUALL LINE
DEVELOPING OVER ILLINOIS AND RAPIDLY INTENSIFIES AS IT MOVES EAST
TOWARD OHIO. TIMING WOULD PUT THE LINE AT TOLEDO AND FINDLAY AT
22Z AND TO CLEVELAND AND MANSFIELD BY ABOUT 00Z AND FINALLY TO
ERIE AND YOUNGSTOWN BY 02Z OR SO. SO THE WAIT BEGINS. STAY TUNED.
PREVIOUS DISCUSSION...
THE LONG ANTICIPATED SEVERE WEATHER THREAT DAY HAS ARRIVED. TWO LOW
PRESSURE SYSTEMS IN THE UPPER MIDWEST ARE BEGINNING TO MERGE AND
INTENSIFY THIS MORNING.
SOUTHERLY FLOW HAS INCREASED ACROSS THE FORECAST AREA AND THIS WILL
BE THE BEGINNING OF THE STRENGTHENING WIND FLOW THROUGHOUT THE DAY.
MODERATELY STRONG LOW LEVEL JET WILL REMAIN PERSISTENT OVER THE
FORECAST AREA TODAY AND WITH THE WARM AIR ADVECTION...SOME OF THE
STRONGER WINDS WILL MIX DOWN TO THE SURFACE. SO...WILL GO AHEAD AND
ISSUE A WIND ADVISORY FOR THE ENTIRE AREA BUT WILL BE FOR MAINLY
LATER THIS EVENING INTO TONIGHT SINCE THE STRONGEST WINDS WILL TAKE
PLACE AFTER THE COLD FRONTAL PASSAGE.
60 TO 70 KNOT SPEED MAXIMUM AT 850 MB WILL POSE A PROBLEM AS
CONVECTION DEVELOPS LATER THIS MORNING INTO THE AFTERNOON HOURS. THE
STRONGER WINDS COULD BE FORCED TO THE SURFACE IN THE THUNDERSTORMS
AND PRODUCE WIDESPREAD WIND DAMAGE. LATEST STORM PREDICTION CENTER
OUTLOOK CONTINUES TO HIGHLIGHT A MODERATE RISK FOR SEVERE
THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A HIGH RISK JUST WEST
OF THE FORECAST AREA.
EVEN THOUGH THE MAIN THREATS WILL BE THE STRONG DAMAGING
WINDS...LATEST MODEL SOUNDING HODOGRAPHS INDICATE SOME FAIRLY HIGH
LEVELS OF HELICITY...ESPECIALLY ACROSS AREAS FROM CLEVELAND TO AKRON
CANTON WEST. I CANT RULE OUT THE POTENTIAL FOR ANY THUNDERSTORMS
THAT DEVELOP THAT THEY COULD BEGIN TO ROTATE RATHER QUICKLY AND
PRODUCE TORNADOES. TEMPERATURE DEW POINT SPREADS ARE PROGGED TO BE
AT OR BELOW THE 5 DEGREE THRESHOLD AND THIS IS ONE KEY INGREDIENT
FOR TORNADOES TO DEVELOP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE SEVERE WEATHER THREAT WILL NOT BE OVER TONIGHT. THE COLD FRONT
AND POTENTIAL SQUALL LINE IS EXPECTED TO MOVE THROUGH THE AREA THIS
EVENING AND THIS IS WHEN WE HAVE THE HIGHEST THREAT FOR WIDESPREAD
WIND DAMAGE. ONE FACTOR IS WE WILL BE LOSING THE DAY TIME HEATING
AND THIS MAY HELP TO STABILIZE THINGS A BIT.
AS THE COLD FRONT SHIFTS EAST...COLD AIR ADVECTION WILL TAKE PLACE
AND ALLOW WINDS TO MIX DOWN TO THE SURFACE. WILL HOIST A WIND
ADVISORY FOR TONIGHT DUE TO THE POST FRONTAL WINDS EXPECTED.
AS THE STRONG LOW PRESSURE SYSTEM MOVES RATHER QUICKLY TO THE
NORTHEAST...WINDS ARE EXPECTED TO DIMINISH FAIRLY QUICKLY MONDAY
INTO TUESDAY.
CYCLONIC FLOW AROUND THE BACK SIDE OF THE LOW AND IN ADVANCE OF THE
NEXT HIGH PRESSURE WILL CAUSE SHOWERS TO CONTINUE OVER THE EXTREME
NORTHEAST PORTION OF THE FORECAST AREA. OTHERWISE...DRIER AIR WILL
BEGIN TO RETURN BACK TO THE REGION ON MONDAY. THE COLD AIR ADVECTION
WILL LIKELY PRODUCE SOME LAKE EFFECT RAIN AND SNOW SHOWERS OVER THE
NORTHEAST MONDAY NIGHT AND TUESDAY. THE HIGH WILL BUILD IN ACROSS
THE OHIO VALLEY AND SHIFT THE FLOW AWAY FROM THE LAKE ENDING THE
LAKE EFFECT THREAT. OTHERWISE...FAIR WEATHER IS EXPECTED ACROSS THE
REST OF THE FORECAST AREA MONDAY INTO TUESDAY AND OVER ALL AREAS
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.
THE COLD FRONT WILL RESULT IN COLD AIR ADVECTION AND PLUNGE
TEMPERATURES BACK TO NEAR NORMAL IN THE 40S FOR HIGHS AND OVERNIGHT
LOWS IN THE 20S TO LOWER 30S.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
NOT MANY CHANGES TO THE LONG TERM TODAY. THE NEW GUIDANCE CONTINUES
TO SHOW THE POSSIBILITY OF WARM AIR ADVECTION SHOWERS ON
THURSDAY...ESPECIALLY IN THE WEST. UNSETTLED WEATHER WILL THEN
CONTINUE INTO NEXT WEEKEND AS A SERIES OF FRONTAL SYSTEMS AFFECTS
THE REGION. IT APPEARS BEST CHANCES FOR PRECIP WILL BE FRIDAY NIGHT
INTO SATURDAY AS A WAVE MOVES ACROSS THE OHIO VALLEY. MOST OF THE
PRECIP SHOULD BE LIQUID ALTHOUGH MIXED RAIN AND SNOW COULD OCCUR
EARLY SATURDAY. TEMPS DURING THE PERIOD WILL BE SEASONABLE AND HAVE
STAYED FAIRLY CLOSE TO GUIDANCE.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
SOUTHERLY WINDS WILL INCREASE THROUGH THE AFTERNOON WITH GUSTS TO
35 KNOTS COMMON ACROSS THE WEST AND ALONG THE LAKESHORE. EXPECT TO
SEE MVFR CLOUD COVER TO SPREAD BACK INTO THE AREA FROM THE SOUTHWEST.
THIS MAY BE A BIT SLOWER TO OCCUR ACROSS THE EAST BUT WITH SOME
SCATTERED SHOWERS WE EXPECT THERE WILL STILL BE AT LEAST SOME PATCHY
MVFR CONDITIONS.
THE MAIN CONCERN WILL BE THE SEVERE THUNDERSTORM POTENTIAL ALONG A
STRONG COLD FRONT THAT WILL ARRIVE IN THE TOLEDO AREA AROUND
22Z...KCLE AND KMFD AROUND 00Z AND KYNG AND KERI AROUND 02Z.
SEVERE GUSTS WILL BE POSSIBLE WITH THE STRONGEST THUNDERSTORMS.
WINDS IN THE WAKE OF THE FRONT WILL SHIFT TO THE SOUTHWEST AND
INCREASE. MOST LOCATIONS WILL SEE GUSTS 35 TO 40 KNOTS THROUGH THE
OVERNIGHT.
OUTLOOK...NON-VFR CONDITIONS WILL BE SCATTERED ACROSS THE REGION
IN SHOWERS. A FEW SHSN MONDAY NIGHT...MAINLY ACROSS NE OH/NW PA.
CONDITIONS IMPROVING TO VFR FROM WEST TO EAST TUESDAY.
&&
.MARINE...
NO CHANGES TO THE HEADLINES ON THE LAKE TODAY. THE GALE STILL LOOKS
GOOD FOR LATE TODAY AND TONIGHT. STILL EXPECTING A SQUALL LINE TO
MOVE ACROSS THE LAKE THIS EVENING AND WIND GUSTS COULD APPROACH 50
KNOTS. WINDS WILL BECOME WESTERLY BEHIND THE COLD FRONT RESPONSIBLE
FOR THE SQUALL LINE. SPEEDS SHOULD GRADUALLY DIMINISH ON MONDAY AND
EXPECT A PROLONGED PERIOD OF SMALL CRAFT ADVISORIES ONCE THE GALE
COMES DOWN. LOCAL GUIDANCE ALSO SHOWS WATER LEVELS MAKING A RUN FOR
THE CRITICAL MARK LATE TONIGHT. WILL SEE HOW THINGS DEVELOP BUT
LATER SHIFTS MAY NEED TO GO WITH A LOW WATER ADVISORY. THE FLOW
WILL BECOME NW ON MONDAY AS HIGH PRESSURE BEGINS TO BUILD IN FROM
THE WEST. A SURFACE RIDGE WILL EVENTUALLY MOVE EAST OF THE LAKE
TUESDAY NIGHT ALLOWING THE FLOW TO BECOME SOUTHERLY. SOUTH TO
SOUTHWEST FLOW WILL THEN CONTINUE TILL A COLD FRONT CROSSES THE LAKE
AT THE VERY END OF THE PERIOD.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR
OHZ003-006>014-017>023-027>033-036>038-047-089.
PA...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR
PAZ001>003.
MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 4 PM EST MONDAY FOR
LEZ061-142>149-162>169.
LOW WATER ADVISORY FROM 7 PM THIS EVENING TO 4 PM EST MONDAY
FOR LEZ142>144-162>164.
&&
$$
SYNOPSIS...KOSARIK/LOMBARDY
NEAR TERM...KOSARIK/LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KUBINA
AVIATION...MULLEN
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1033 AM EST SUN NOV 17 2013
.SYNOPSIS...
LOW PRESSURE OVER THE PLAINS STATES WILL DEEPEN RAPIDLY AS IT
MOVES NORTHEAST TODAY REACHING NORTHERN LAKE MICHIGAN BY THIS
EVENING AND INTO QUEBEC ON MONDAY. THIS WILL PUSH A STRONG COLD
FRONT ACROSS THE AREA THIS EVENING. HIGH PRESSURE WILL MOVE EAST
OUT OF THE SOUTHERN PLAINS STATES INTO THE OHIO VALLEY BY TUESDAY
AND THEN OFF THE EAST COAST ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REMOVED THUNDER ACROSS NORTH CENTRAL OHIO AND POINTS EAST UNTIL
VERY LATE AFTERNOON/EVENING. WHILE I CANNOT RULE OUT THUNDER...
WOULD LIKE TO MAKE THE THUNDER AND WIND WITH THE FRONT MORE OF THE
FOCAL POINT OF THE FORECAST. TOUGH TO DO IN THESE DAYS OF
AUTOMATED TEXT FORMATTERS...SO NOT SURE EXACTLY WHAT THE WORDING
WILL SAY. BETTER CHANCE FOR THUNDER AT ANY TIME IN THE DRY SLOT
THAT IS CREEPING ACROSS NORTHWEST OHIO. SORT OF LOOKS LIKE
OKLAHOMA IN THE SPRING TIME...HMMM.
NO OTHER SIGNIFICANT CHANGES TO THE FORECAST. DID NUDGE UP HIGH
TEMPERATURES A COUPLE OF DEGREES ACROSS NW OHIO AND PARTS OF NORTH
CENTRAL OHIO WHERE THERE WILL NOT BE AS MANY SHOWERS. RECORD HIGH
IN TOLEDO IS 71 AND WE WILL TAKE A RUN AT IT. 72 AT CLE IS
POTENTIALLY WITHIN REACH.
RELEVANT EARLY MORNING UPDATED DISCUSSION...
SHOWERS CONTINUE TO MOVE EAST AND OUT OF THE AREA AT THIS TIME.
CELLULAR CONVECTION CONTINUES TO MOVE INTO EXTREME NORTHWEST OHIO
AND SOUTHERN LOWER MICHIGAN. THE WATER VAPOR PLUME IS ALSO PUSHING
EAST ALLOWING FOR SOME DRIER AIR TO MOVE EAST AND ALLOW FOR A
BREAK IN THE ACTION. LATEST HRRR MODEL SHOWS MASSIVE SQUALL LINE
DEVELOPING OVER ILLINOIS AND RAPIDLY INTENSIFIES AS IT MOVES EAST
TOWARD OHIO. TIMING WOULD PUT THE LINE AT TOLEDO AND FINDLAY AT
22Z AND TO CLEVELAND AND MANSFIELD BY ABOUT 00Z AND FINALLY TO
ERIE AND YOUNGSTOWN BY 02Z OR SO. SO THE WAIT BEGINS. STAY TUNED.
PREVIOUS DISCUSSION...
THE LONG ANTICIPATED SEVERE WEATHER THREAT DAY HAS ARRIVED. TWO LOW
PRESSURE SYSTEMS IN THE UPPER MIDWEST ARE BEGINNING TO MERGE AND
INTENSIFY THIS MORNING.
SOUTHERLY FLOW HAS INCREASED ACROSS THE FORECAST AREA AND THIS WILL
BE THE BEGINNING OF THE STRENGTHENING WIND FLOW THROUGHOUT THE DAY.
MODERATELY STRONG LOW LEVEL JET WILL REMAIN PERSISTENT OVER THE
FORECAST AREA TODAY AND WITH THE WARM AIR ADVECTION...SOME OF THE
STRONGER WINDS WILL MIX DOWN TO THE SURFACE. SO...WILL GO AHEAD AND
ISSUE A WIND ADVISORY FOR THE ENTIRE AREA BUT WILL BE FOR MAINLY
LATER THIS EVENING INTO TONIGHT SINCE THE STRONGEST WINDS WILL TAKE
PLACE AFTER THE COLD FRONTAL PASSAGE.
60 TO 70 KNOT SPEED MAXIMUM AT 850 MB WILL POSE A PROBLEM AS
CONVECTION DEVELOPS LATER THIS MORNING INTO THE AFTERNOON HOURS. THE
STRONGER WINDS COULD BE FORCED TO THE SURFACE IN THE THUNDERSTORMS
AND PRODUCE WIDESPREAD WIND DAMAGE. LATEST STORM PREDICTION CENTER
OUTLOOK CONTINUES TO HIGHLIGHT A MODERATE RISK FOR SEVERE
THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A HIGH RISK JUST WEST
OF THE FORECAST AREA.
EVEN THOUGH THE MAIN THREATS WILL BE THE STRONG DAMAGING
WINDS...LATEST MODEL SOUNDING HODOGRAPHS INDICATE SOME FAIRLY HIGH
LEVELS OF HELICITY...ESPECIALLY ACROSS AREAS FROM CLEVELAND TO AKRON
CANTON WEST. I CANT RULE OUT THE POTENTIAL FOR ANY THUNDERSTORMS
THAT DEVELOP THAT THEY COULD BEGIN TO ROTATE RATHER QUICKLY AND
PRODUCE TORNADOES. TEMPERATURE DEW POINT SPREADS ARE PROGGED TO BE
AT OR BELOW THE 5 DEGREE THRESHOLD AND THIS IS ONE KEY INGREDIENT
FOR TORNADOES TO DEVELOP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE SEVERE WEATHER THREAT WILL NOT BE OVER TONIGHT. THE COLD FRONT
AND POTENTIAL SQUALL LINE IS EXPECTED TO MOVE THROUGH THE AREA THIS
EVENING AND THIS IS WHEN WE HAVE THE HIGHEST THREAT FOR WIDESPREAD
WIND DAMAGE. ONE FACTOR IS WE WILL BE LOSING THE DAY TIME HEATING
AND THIS MAY HELP TO STABILIZE THINGS A BIT.
AS THE COLD FRONT SHIFTS EAST...COLD AIR ADVECTION WILL TAKE PLACE
AND ALLOW WINDS TO MIX DOWN TO THE SURFACE. WILL HOIST A WIND
ADVISORY FOR TONIGHT DUE TO THE POST FRONTAL WINDS EXPECTED.
AS THE STRONG LOW PRESSURE SYSTEM MOVES RATHER QUICKLY TO THE
NORTHEAST...WINDS ARE EXPECTED TO DIMINISH FAIRLY QUICKLY MONDAY
INTO TUESDAY.
CYCLONIC FLOW AROUND THE BACK SIDE OF THE LOW AND IN ADVANCE OF THE
NEXT HIGH PRESSURE WILL CAUSE SHOWERS TO CONTINUE OVER THE EXTREME
NORTHEAST PORTION OF THE FORECAST AREA. OTHERWISE...DRIER AIR WILL
BEGIN TO RETURN BACK TO THE REGION ON MONDAY. THE COLD AIR ADVECTION
WILL LIKELY PRODUCE SOME LAKE EFFECT RAIN AND SNOW SHOWERS OVER THE
NORTHEAST MONDAY NIGHT AND TUESDAY. THE HIGH WILL BUILD IN ACROSS
THE OHIO VALLEY AND SHIFT THE FLOW AWAY FROM THE LAKE ENDING THE
LAKE EFFECT THREAT. OTHERWISE...FAIR WEATHER IS EXPECTED ACROSS THE
REST OF THE FORECAST AREA MONDAY INTO TUESDAY AND OVER ALL AREAS
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.
THE COLD FRONT WILL RESULT IN COLD AIR ADVECTION AND PLUNGE
TEMPERATURES BACK TO NEAR NORMAL IN THE 40S FOR HIGHS AND OVERNIGHT
LOWS IN THE 20S TO LOWER 30S.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
NOT MANY CHANGES TO THE LONG TERM TODAY. THE NEW GUIDANCE CONTINUES
TO SHOW THE POSSIBILITY OF WARM AIR ADVECTION SHOWERS ON
THURSDAY...ESPECIALLY IN THE WEST. UNSETTLED WEATHER WILL THEN
CONTINUE INTO NEXT WEEKEND AS A SERIES OF FRONTAL SYSTEMS AFFECTS
THE REGION. IT APPEARS BEST CHANCES FOR PRECIP WILL BE FRIDAY NIGHT
INTO SATURDAY AS A WAVE MOVES ACROSS THE OHIO VALLEY. MOST OF THE
PRECIP SHOULD BE LIQUID ALTHOUGH MIXED RAIN AND SNOW COULD OCCUR
EARLY SATURDAY. TEMPS DURING THE PERIOD WILL BE SEASONABLE AND HAVE
STAYED FAIRLY CLOSE TO GUIDANCE.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
A LARGE AREA OF SHOWERS REMAINS OVER THE EASTERN HALF OF THE AREA
THIS MORNING AND IS EXPECTED TO EXIT TO THE EAST IN A COUPLE OF
HOURS. MOST LOCATIONS REMAIN VFR BUT SOME PATCHY MVFR IS BEING
REPORTED. A LOT OF MVFR CIGS TO THE WEST AND EXPECT ALL AREAS TO
DIP TO MVFR CIGS BY MIDDAY. SHOWER ACTIVITY TO THE WEST OF THE
MAIN AREA WILL BE SCATTERED IN NATURE THIS MORNING. EXPECT MUCH OF
THE AFTERNOON TO BE DRY WITH A FEW PEAKS OF SUNSHINE POSSIBLE. NEW
GUIDANCE COMING IN CONTINUES TO SHOW A SQUALL LINE DEVELOPING
OVER NW OH TOWARD EVENING. CONFIDENCE IN THIS SCENARIO IS
UNUSUALLY HIGH. THIS LINE SHOULD REACH KTOL AND KFDY AROUND SUNSET
AND IS THEN EXPECTED TO RACE EAST ACROSS THE REMAINDER OF THE AREA
THIS EVENING. THE LINE COULD MOVE AS FAST AS 45 TO 50 KNOTS AT
TIMES. VERY STRONG WINDS ARE FORECAST JUST ABOVE THE SURFACE AND
ANY SIGNIFICANT RAIN WILL BRING THESE STRONG WINDS DOWN TO THE
SURFACE. AS A RESULT HAVE CONTINUED TO HIT THE WINDS PRETTY HARD
IN THE NEW FORECAST. A COLD FRONT WILL FOLLOW THE SQUALL LINE
ACROSS THE AREA THIS EVENING AND EXPECT CIGS TO LIFT TO VFR AND
THEN DISSIPATE FROM WEST TO EAST OVERNIGHT. WINDS TODAY WILL BE
MAINLY FROM THE SOUTH WITH GUSTS INCREASING TO 35 KNOTS THIS
AFTERNOON. THE FLOW BEHIND THE FRONT WILL BE WSW AND GUSTS COULD
GET TO 40 KNOTS OVERNIGHT.
OUTLOOK...NON-VFR CONDITIONS WILL CONTINUE SUNDAY NIGHT INTO
MONDAY WITH A FEW SHRA. A FEW SHSN MONDAY NIGHT...MAINLY ACROSS NE
OH/NW PA. CONDITIONS IMPROVING TO VFR FROM WEST TO EAST TUESDAY.
&&
.MARINE...
NO CHANGES TO THE HEADLINES ON THE LAKE TODAY. THE GALE STILL LOOKS
GOOD FOR LATE TODAY AND TONIGHT. STILL EXPECTING A SQUALL LINE TO
MOVE ACROSS THE LAKE THIS EVENING AND WIND GUSTS COULD APPROACH 50
KNOTS. WINDS WILL BECOME WESTERLY BEHIND THE COLD FRONT RESPONSIBLE
FOR THE SQUALL LINE. SPEEDS SHOULD GRADUALLY DIMINISH ON MONDAY AND
EXPECT A PROLONGED PERIOD OF SMALL CRAFT ADVISORIES ONCE THE GALE
COMES DOWN. LOCAL GUIDANCE ALSO SHOWS WATER LEVELS MAKING A RUN FOR
THE CRITICAL MARK LATE TONIGHT. WILL SEE HOW THINGS DEVELOP BUT
LATER SHIFTS MAY NEED TO GO WITH A LOW WATER ADVISORY. THE FLOW
WILL BECOME NW ON MONDAY AS HIGH PRESSURE BEGINS TO BUILD IN FROM
THE WEST. A SURFACE RIDGE WILL EVENTUALLY MOVE EAST OF THE LAKE
TUESDAY NIGHT ALLOWING THE FLOW TO BECOME SOUTHERLY. SOUTH TO
SOUTHWEST FLOW WILL THEN CONTINUE TILL A COLD FRONT CROSSES THE LAKE
AT THE VERY END OF THE PERIOD.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR
OHZ003-006>014-017>023-027>033-036>038-047-089.
PA...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR
PAZ001>003.
MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 4 PM EST MONDAY FOR
LEZ061-142>149-162>169.
&&
$$
SYNOPSIS...KOSARIK/LOMBARDY
NEAR TERM...KOSARIK/LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1020 AM EST SUN NOV 17 2013
.SYNOPSIS...
LOW PRESSURE OVER THE PLAINS STATES WILL DEEPEN RAPIDLY AS IT
MOVES NORTHEAST TODAY REACHING NORTHERN LAKE MICHIGAN BY THIS
EVENING AND INTO QUEBEC ON MONDAY. THIS WILL PUSH A STRONG COLD
FRONT ACROSS THE AREA THIS EVENING. HIGH PRESSURE WILL MOVE EAST
OUT OF THE SOUTHERN PLAINS STATES INTO THE OHIO VALLEY BY TUESDAY
AND THEN OFF THE EAST COAST ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REMOVED THUNDER ACROSS NORTH CENTRAL OHIO AND POINTS EAST UNTIL
VERY LATE AFTERNOON/EVENING. WHILE I CANNOT RULE OUT THUNDER...
WOULD LIKE TO MAKE THE THUNDER AND WIND WITH THE FRONT MORE OF THE
FOCAL POINT OF THE FORECAST. TOUGH TO DO IN THESE DAYS OF
AUTOMATED TEXT FORMATTERS...SO NOT SURE EXACTLY WHAT THE WORDING
WILL SAY. THUNDER FORECAST ON THE EAST FOR MIDDAY AND EARLY
AFTERNOON. BETTER CHANCE FOR THUNDER AT ANY TIME IN THE DRY SLOT
THAT IS CREEPING ACROSS NORTHWEST OHIO. SORT OF LOOKS LIKE
OKLAHOMA IN THE SPRING TIME...HMMM. NO OTHER SIGNIFICANT CHANGES
TO THE FORECAST. DID NUDGE UP HIGH TEMPERATURES A COUPLE OF DEGREES
ACROSS NW OHIO AND PARTS OF NORTH CENTRAL OHIO WHERE THERE WILL
NOT BE AS MANY SHOWERS. RECORD HIGH IN TOLEDO IS 71 AND WE WILL
TAKE A RUN AT IT. 72 AT CLE IS POTENTIALLY WITHIN REACH.
RELEVANT EARLY MORNING UPDATED DISCUSSION...
SHOWERS CONTINUE TO MOVE EAST AND OUT OF THE AREA AT THIS TIME.
CELLULAR CONVECTION CONTINUES TO MOVE INTO EXTREME NORTHWEST OHIO
AND SOUTHERN LOWER MICHIGAN. THE WATER VAPOR PLUME IS ALSO PUSHING
EAST ALLOWING FOR SOME DRIER AIR TO MOVE EAST AND ALLOW FOR A
BREAK IN THE ACTION. LATEST HRRR MODEL SHOWS MASSIVE SQUALL LINE
DEVELOPING OVER ILLINOIS AND RAPIDLY INTENSIFIES AS IT MOVES EAST
TOWARD OHIO. TIMING WOULD PUT THE LINE AT TOLEDO AND FINDLAY AT
22Z AND TO CLEVELAND AND MANSFIELD BY ABOUT 00Z AND FINALLY TO
ERIE AND YOUNGSTOWN BY 02Z OR SO. SO THE WAIT BEGINS. STAY TUNED.
PREVIOUS DISCUSSION...
THE LONG ANTICIPATED SEVERE WEATHER THREAT DAY HAS ARRIVED. TWO LOW
PRESSURE SYSTEMS IN THE UPPER MIDWEST ARE BEGINNING TO MERGE AND
INTENSIFY THIS MORNING.
SOUTHERLY FLOW HAS INCREASED ACROSS THE FORECAST AREA AND THIS WILL
BE THE BEGINNING OF THE STRENGTHENING WIND FLOW THROUGHOUT THE DAY.
MODERATELY STRONG LOW LEVEL JET WILL REMAIN PERSISTENT OVER THE
FORECAST AREA TODAY AND WITH THE WARM AIR ADVECTION...SOME OF THE
STRONGER WINDS WILL MIX DOWN TO THE SURFACE. SO...WILL GO AHEAD AND
ISSUE A WIND ADVISORY FOR THE ENTIRE AREA BUT WILL BE FOR MAINLY
LATER THIS EVENING INTO TONIGHT SINCE THE STRONGEST WINDS WILL TAKE
PLACE AFTER THE COLD FRONTAL PASSAGE.
60 TO 70 KNOT SPEED MAXIMUM AT 850 MB WILL POSE A PROBLEM AS
CONVECTION DEVELOPS LATER THIS MORNING INTO THE AFTERNOON HOURS. THE
STRONGER WINDS COULD BE FORCED TO THE SURFACE IN THE THUNDERSTORMS
AND PRODUCE WIDESPREAD WIND DAMAGE. LATEST STORM PREDICTION CENTER
OUTLOOK CONTINUES TO HIGHLIGHT A MODERATE RISK FOR SEVERE
THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A HIGH RISK JUST WEST
OF THE FORECAST AREA.
EVEN THOUGH THE MAIN THREATS WILL BE THE STRONG DAMAGING
WINDS...LATEST MODEL SOUNDING HODOGRAPHS INDICATE SOME FAIRLY HIGH
LEVELS OF HELICITY...ESPECIALLY ACROSS AREAS FROM CLEVELAND TO AKRON
CANTON WEST. I CANT RULE OUT THE POTENTIAL FOR ANY THUNDERSTORMS
THAT DEVELOP THAT THEY COULD BEGIN TO ROTATE RATHER QUICKLY AND
PRODUCE TORNADOES. TEMPERATURE DEW POINT SPREADS ARE PROGGED TO BE
AT OR BELOW THE 5 DEGREE THRESHOLD AND THIS IS ONE KEY INGREDIENT
FOR TORNADOES TO DEVELOP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE SEVERE WEATHER THREAT WILL NOT BE OVER TONIGHT. THE COLD FRONT
AND POTENTIAL SQUALL LINE IS EXPECTED TO MOVE THROUGH THE AREA THIS
EVENING AND THIS IS WHEN WE HAVE THE HIGHEST THREAT FOR WIDESPREAD
WIND DAMAGE. ONE FACTOR IS WE WILL BE LOSING THE DAY TIME HEATING
AND THIS MAY HELP TO STABILIZE THINGS A BIT.
AS THE COLD FRONT SHIFTS EAST...COLD AIR ADVECTION WILL TAKE PLACE
AND ALLOW WINDS TO MIX DOWN TO THE SURFACE. WILL HOIST A WIND
ADVISORY FOR TONIGHT DUE TO THE POST FRONTAL WINDS EXPECTED.
AS THE STRONG LOW PRESSURE SYSTEM MOVES RATHER QUICKLY TO THE
NORTHEAST...WINDS ARE EXPECTED TO DIMINISH FAIRLY QUICKLY MONDAY
INTO TUESDAY.
CYCLONIC FLOW AROUND THE BACK SIDE OF THE LOW AND IN ADVANCE OF THE
NEXT HIGH PRESSURE WILL CAUSE SHOWERS TO CONTINUE OVER THE EXTREME
NORTHEAST PORTION OF THE FORECAST AREA. OTHERWISE...DRIER AIR WILL
BEGIN TO RETURN BACK TO THE REGION ON MONDAY. THE COLD AIR ADVECTION
WILL LIKELY PRODUCE SOME LAKE EFFECT RAIN AND SNOW SHOWERS OVER THE
NORTHEAST MONDAY NIGHT AND TUESDAY. THE HIGH WILL BUILD IN ACROSS
THE OHIO VALLEY AND SHIFT THE FLOW AWAY FROM THE LAKE ENDING THE
LAKE EFFECT THREAT. OTHERWISE...FAIR WEATHER IS EXPECTED ACROSS THE
REST OF THE FORECAST AREA MONDAY INTO TUESDAY AND OVER ALL AREAS
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.
THE COLD FRONT WILL RESULT IN COLD AIR ADVECTION AND PLUNGE
TEMPERATURES BACK TO NEAR NORMAL IN THE 40S FOR HIGHS AND OVERNIGHT
LOWS IN THE 20S TO LOWER 30S.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
NOT MANY CHANGES TO THE LONG TERM TODAY. THE NEW GUIDANCE CONTINUES
TO SHOW THE POSSIBILITY OF WARM AIR ADVECTION SHOWERS ON
THURSDAY...ESPECIALLY IN THE WEST. UNSETTLED WEATHER WILL THEN
CONTINUE INTO NEXT WEEKEND AS A SERIES OF FRONTAL SYSTEMS AFFECTS
THE REGION. IT APPEARS BEST CHANCES FOR PRECIP WILL BE FRIDAY NIGHT
INTO SATURDAY AS A WAVE MOVES ACROSS THE OHIO VALLEY. MOST OF THE
PRECIP SHOULD BE LIQUID ALTHOUGH MIXED RAIN AND SNOW COULD OCCUR
EARLY SATURDAY. TEMPS DURING THE PERIOD WILL BE SEASONABLE AND HAVE
STAYED FAIRLY CLOSE TO GUIDANCE.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
A LARGE AREA OF SHOWERS REMAINS OVER THE EASTERN HALF OF THE AREA
THIS MORNING AND IS EXPECTED TO EXIT TO THE EAST IN A COUPLE OF
HOURS. MOST LOCATIONS REMAIN VFR BUT SOME PATCHY MVFR IS BEING
REPORTED. A LOT OF MVFR CIGS TO THE WEST AND EXPECT ALL AREAS TO
DIP TO MVFR CIGS BY MIDDAY. SHOWER ACTIVITY TO THE WEST OF THE
MAIN AREA WILL BE SCATTERED IN NATURE THIS MORNING. EXPECT MUCH OF
THE AFTERNOON TO BE DRY WITH A FEW PEAKS OF SUNSHINE POSSIBLE. NEW
GUIDANCE COMING IN CONTINUES TO SHOW A SQUALL LINE DEVELOPING
OVER NW OH TOWARD EVENING. CONFIDENCE IN THIS SCENARIO IS
UNUSUALLY HIGH. THIS LINE SHOULD REACH KTOL AND KFDY AROUND SUNSET
AND IS THEN EXPECTED TO RACE EAST ACROSS THE REMAINDER OF THE AREA
THIS EVENING. THE LINE COULD MOVE AS FAST AS 45 TO 50 KNOTS AT
TIMES. VERY STRONG WINDS ARE FORECAST JUST ABOVE THE SURFACE AND
ANY SIGNIFICANT RAIN WILL BRING THESE STRONG WINDS DOWN TO THE
SURFACE. AS A RESULT HAVE CONTINUED TO HIT THE WINDS PRETTY HARD
IN THE NEW FORECAST. A COLD FRONT WILL FOLLOW THE SQUALL LINE
ACROSS THE AREA THIS EVENING AND EXPECT CIGS TO LIFT TO VFR AND
THEN DISSIPATE FROM WEST TO EAST OVERNIGHT. WINDS TODAY WILL BE
MAINLY FROM THE SOUTH WITH GUSTS INCREASING TO 35 KNOTS THIS
AFTERNOON. THE FLOW BEHIND THE FRONT WILL BE WSW AND GUSTS COULD
GET TO 40 KNOTS OVERNIGHT.
OUTLOOK...NON-VFR CONDITIONS WILL CONTINUE SUNDAY NIGHT INTO
MONDAY WITH A FEW SHRA. A FEW SHSN MONDAY NIGHT...MAINLY ACROSS NE
OH/NW PA. CONDITIONS IMPROVING TO VFR FROM WEST TO EAST TUESDAY.
&&
.MARINE...
NO CHANGES TO THE HEADLINES ON THE LAKE TODAY. THE GALE STILL LOOKS
GOOD FOR LATE TODAY AND TONIGHT. STILL EXPECTING A SQUALL LINE TO
MOVE ACROSS THE LAKE THIS EVENING AND WIND GUSTS COULD APPROACH 50
KNOTS. WINDS WILL BECOME WESTERLY BEHIND THE COLD FRONT RESPONSIBLE
FOR THE SQUALL LINE. SPEEDS SHOULD GRADUALLY DIMINISH ON MONDAY AND
EXPECT A PROLONGED PERIOD OF SMALL CRAFT ADVISORIES ONCE THE GALE
COMES DOWN. LOCAL GUIDANCE ALSO SHOWS WATER LEVELS MAKING A RUN FOR
THE CRITICAL MARK LATE TONIGHT. WILL SEE HOW THINGS DEVELOP BUT
LATER SHIFTS MAY NEED TO GO WITH A LOW WATER ADVISORY. THE FLOW
WILL BECOME NW ON MONDAY AS HIGH PRESSURE BEGINS TO BUILD IN FROM
THE WEST. A SURFACE RIDGE WILL EVENTUALLY MOVE EAST OF THE LAKE
TUESDAY NIGHT ALLOWING THE FLOW TO BECOME SOUTHERLY. SOUTH TO
SOUTHWEST FLOW WILL THEN CONTINUE TILL A COLD FRONT CROSSES THE LAKE
AT THE VERY END OF THE PERIOD.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR
OHZ003-006>014-017>023-027>033-036>038-047-089.
PA...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR
PAZ001>003.
MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 4 PM EST MONDAY FOR
LEZ061-142>149-162>169.
&&
$$
SYNOPSIS...KOSARIK/LOMBARDY
NEAR TERM...KOSARIK/LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
642 AM EST SUN NOV 17 2013
.SYNOPSIS...
A DOUBLED BARRELED LOW PRESSURE FROM SOUTHERN MINNESOTA TO WESTERN
KANSAS WILL MOVE TO NORTHERN LAKE MICHIGAN BY THIS EVENING.
MEANWHILE...THE LOW PRESSURE WILL DEEPEN RAPIDLY AS IT MOVES INTO
WEST CENTRAL QUEBEC BY MONDAY AFTERNOON. A STRONG COLD FRONT WILL
SWEEP EAST ACROSS THE AREA TONIGHT. HIGH PRESSURE WILL MOVE EAST OUT
OF THE SOUTHERN PLAINS STATES INTO THE OHIO VALLEY BY TUESDAY AND
THEN OFF THE EAST COAST ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS CONTINUE TO MOVE EAST AND OUT OF THE AREA AT THIS TIME.
CELLULAR CONVECTION CONTINUES TO MOVE INTO EXTREME NORTHWEST OHIO
AND SOUTHERN LOWER MICHIGAN. THE WATER VAPOR PLUME IS ALSO PUSHING
EAST ALLOWING FOR SOME DRIER AIR TO MOVE EAST AND ALLOW FOR A
BREAK IN THE ACTION. LATEST HRRR MODEL SHOWS MASSIVE SQUALL LINE
DEVELOPING OVER ILLINOIS AND RAPIDLY INTENSIFIES AS IT MOVES EAST
TOWARD OHIO. TIMING WOULD PUT THE LINE AT TOLEDO AND FINDLAY AT
22Z AND TO CLEVELAND AND MANSFIELD BY ABOUT 00Z AND FINALLY TO
ERIE AND YOUNGSTOWN BY 02Z OR SO. SO THE WAIT BEGINS. STAY TUNED.
PREVIOUS DISCUSSION...
THE LONG ANTICIPATED SEVERE WEATHER THREAT DAY HAS ARRIVED. TWO LOW
PRESSURE SYSTEMS IN THE UPPER MIDWEST ARE BEGINNING TO MERGE AND
INTENSIFY THIS MORNING.
SOUTHERLY FLOW HAS INCREASED ACROSS THE FORECAST AREA AND THIS WILL
BE THE BEGINNING OF THE STRENGTHENING WIND FLOW THROUGHOUT THE DAY.
MODERATELY STRONG LOW LEVEL JET WILL REMAIN PERSISTENT OVER THE
FORECAST AREA TODAY AND WITH THE WARM AIR ADVECTION...SOME OF THE
STRONGER WINDS WILL MIX DOWN TO THE SURFACE. SO...WILL GO AHEAD AND
ISSUE A WIND ADVISORY FOR THE ENTIRE AREA BUT WILL BE FOR MAINLY
LATER THIS EVENING INTO TONIGHT SINCE THE STRONGEST WINDS WILL TAKE
PLACE AFTER THE COLD FRONTAL PASSAGE.
60 TO 70 KNOT SPEED MAXIMUM AT 850 MB WILL POSE A PROBLEM AS
CONVECTION DEVELOPS LATER THIS MORNING INTO THE AFTERNOON HOURS. THE
STRONGER WINDS COULD BE FORCED TO THE SURFACE IN THE THUNDERSTORMS
AND PRODUCE WIDESPREAD WIND DAMAGE. LATEST STORM PREDICTION CENTER
OUTLOOK CONTINUES TO HIGHLIGHT A MODERATE RISK FOR SEVERE
THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A HIGH RISK JUST WEST
OF THE FORECAST AREA.
EVEN THOUGH THE MAIN THREATS WILL BE THE STRONG DAMAGING
WINDS...LATEST MODEL SOUNDING HODOGRAPHS INDICATE SOME FAIRLY HIGH
LEVELS OF HELICITY...ESPECIALLY ACROSS AREAS FROM CLEVELAND TO AKRON
CANTON WEST. I CANT RULE OUT THE POTENTIAL FOR ANY THUNDERSTORMS
THAT DEVELOP THAT THEY COULD BEGIN TO ROTATE RATHER QUICKLY AND
PRODUCE TORNADOES. TEMPERATURE DEW POINT SPREADS ARE PROGGED TO BE
AT OR BELOW THE 5 DEGREE THRESHOLD AND THIS IS ONE KEY INGREDIENT
FOR TORNADOES TO DEVELOP.
LOOKING AT THE LATEST WATER VAPOR IMAGERY SHOWS AN EXTENSIVE AREA OF
MOISTURE STREAMING NORTH ACROSS THE FORECAST AREA AT THIS TIME.
HOWEVER...JUST WEST OF THE AREA...THIS MOISTURE PLUME DIMINISHES AND
THIS IS RESULTING IN CLEARING SKIES WELL AHEAD OF THE COLD FRONT.
WITH THIS IN MIND...I AM CONCERNED THAT WE WILL SEE A LOT MORE SUN
THAN I CURRENTLY HAVE IN THE FORECAST. IF THIS IS THE CASE...THEN
CURRENT FORECAST TEMPERATURES COULD BE TOO LOW AND THEREFORE WILL
SEE EVEN GREATER INSTABILITY DEVELOP. THIS WILL HAVE TO BE WATCHED
CLOSELY TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE SEVERE WEATHER THREAT WILL NOT BE OVER TONIGHT. THE COLD FRONT
AND POTENTIAL SQUALL LINE IS EXPECTED TO MOVE THROUGH THE AREA THIS
EVENING AND THIS IS WHEN WE HAVE THE HIGHEST THREAT FOR WIDESPREAD
WIND DAMAGE. ONE FACTOR IS WE WILL BE LOSING THE DAY TIME HEATING
AND THIS MAY HELP TO STABILIZE THINGS A BIT.
AS THE COLD FRONT SHIFTS EAST...COLD AIR ADVECTION WILL TAKE PLACE
AND ALLOW WINDS TO MIX DOWN TO THE SURFACE. WILL HOIST A WIND
ADVISORY FOR TONIGHT DUE TO THE POST FRONTAL WINDS EXPECTED.
AS THE STRONG LOW PRESSURE SYSTEM MOVES RATHER QUICKLY TO THE
NORTHEAST...WINDS ARE EXPECTED TO DIMINISH FAIRLY QUICKLY MONDAY
INTO TUESDAY.
CYCLONIC FLOW AROUND THE BACK SIDE OF THE LOW AND IN ADVANCE OF THE
NEXT HIGH PRESSURE WILL CAUSE SHOWERS TO CONTINUE OVER THE EXTREME
NORTHEAST PORTION OF THE FORECAST AREA. OTHERWISE...DRIER AIR WILL
BEGIN TO RETURN BACK TO THE REGION ON MONDAY. THE COLD AIR ADVECTION
WILL LIKELY PRODUCE SOME LAKE EFFECT RAIN AND SNOW SHOWERS OVER THE
NORTHEAST MONDAY NIGHT AND TUESDAY. THE HIGH WILL BUILD IN ACROSS
THE OHIO VALLEY AND SHIFT THE FLOW AWAY FROM THE LAKE ENDING THE
LAKE EFFECT THREAT. OTHERWISE...FAIR WEATHER IS EXPECTED ACROSS THE
REST OF THE FORECAST AREA MONDAY INTO TUESDAY AND OVER ALL AREAS
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.
THE COLD FRONT WILL RESULT IN COLD AIR ADVECTION AND PLUNGE
TEMPERATURES BACK TO NEAR NORMAL IN THE 40S FOR HIGHS AND OVERNIGHT
LOWS IN THE 20S TO LOWER 30S.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
NOT MANY CHANGES TO THE LONG TERM TODAY. THE NEW GUIDANCE CONTINUES
TO SHOW THE POSSIBILITY OF WARM AIR ADVECTION SHOWERS ON
THURSDAY...ESPECIALLY IN THE WEST. UNSETTLED WEATHER WILL THEN
CONTINUE INTO NEXT WEEKEND AS A SERIES OF FRONTAL SYSTEMS AFFECTS
THE REGION. IT APPEARS BEST CHANCES FOR PRECIP WILL BE FRIDAY NIGHT
INTO SATURDAY AS A WAVE MOVES ACROSS THE OHIO VALLEY. MOST OF THE
PRECIP SHOULD BE LIQUID ALTHOUGH MIXED RAIN AND SNOW COULD OCCUR
EARLY SATURDAY. TEMPS DURING THE PERIOD WILL BE SEASONABLE AND HAVE
STAYED FAIRLY CLOSE TO GUIDANCE.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A LARGE AREA OF SHOWERS REMAINS OVER THE EASTERN HALF OF THE AREA
THIS MORNING AND IS EXPECTED TO EXIT TO THE EAST IN A COUPLE OF
HOURS. MOST LOCATIONS REMAIN VFR BUT SOME PATCHY MVFR IS BEING
REPORTED. A LOT OF MVFR CIGS TO THE WEST AND EXPECT ALL AREAS TO
DIP TO MVFR CIGS BY MIDDAY. SHOWER ACTIVITY TO THE WEST OF THE
MAIN AREA WILL BE SCATTERED IN NATURE THIS MORNING. EXPECT MUCH OF
THE AFTERNOON TO BE DRY WITH A FEW PEAKS OF SUNSHINE POSSIBLE. NEW
GUIDANCE COMING IN CONTINUES TO SHOW A SQUALL LINE DEVELOPING
OVER NW OH TOWARD EVENING. CONFIDENCE IN THIS SCENARIO IS
UNUSUALLY HIGH. THIS LINE SHOULD REACH KTOL AND KFDY AROUND SUNSET
AND IS THEN EXPECTED TO RACE EAST ACROSS THE REMAINDER OF THE AREA
THIS EVENING. THE LINE COULD MOVE AS FAST AS 45 TO 50 KNOTS AT
TIMES. VERY STRONG WINDS ARE FORECAST JUST ABOVE THE SURFACE AND
ANY SIGNIFICANT RAIN WILL BRING THESE STRONG WINDS DOWN TO THE
SURFACE. AS A RESULT HAVE CONTINUED TO HIT THE WINDS PRETTY HARD
IN THE NEW FORECAST. A COLD FRONT WILL FOLLOW THE SQUALL LINE
ACROSS THE AREA THIS EVENING AND EXPECT CIGS TO LIFT TO VFR AND
THEN DISSIPATE FROM WEST TO EAST OVERNIGHT. WINDS TODAY WILL BE
MAINLY FROM THE SOUTH WITH GUSTS INCREASING TO 35 KNOTS THIS
AFTERNOON. THE FLOW BEHIND THE FRONT WILL BE WSW AND GUSTS COULD
GET TO 40 KNOTS OVERNIGHT.
OUTLOOK...NON-VFR CONDITIONS WILL CONTINUE SUNDAY NIGHT INTO
MONDAY WITH A FEW SHRA. A FEW SHSN MONDAY NIGHT...MAINLY ACROSS NE
OH/NW PA. CONDITIONS IMPROVING TO VFR FROM WEST TO EAST TUESDAY.
&&
.MARINE...
NO CHANGES TO THE HEADLINES ON THE LAKE TODAY. THE GALE STILL LOOKS
GOOD FOR LATE TODAY AND TONIGHT. STILL EXPECTING A SQUALL LINE TO
MOVE ACROSS THE LAKE THIS EVENING AND WIND GUSTS COULD APPROACH 50
KNOTS. WINDS WILL BECOME WESTERLY BEHIND THE COLD FRONT RESPONSIBLE
FOR THE SQUALL LINE. SPEEDS SHOULD GRADUALLY DIMINISH ON MONDAY AND
EXPECT A PROLONGED PERIOD OF SMALL CRAFT ADVISORIES ONCE THE GALE
COMES DOWN. LOCAL GUIDANCE ALSO SHOWS WATER LEVELS MAKING A RUN FOR
THE CRITICAL MARK LATE TONIGHT. WILL SEE HOW THINGS DEVELOP BUT
LATER SHIFTS MAY NEED TO GO WITH A LOW WATER ADVISORY. THE FLOW
WILL BECOME NW ON MONDAY AS HIGH PRESSURE BEGINS TO BUILD IN FROM
THE WEST. A SURFACE RIDGE WILL EVENTUALLY MOVE EAST OF THE LAKE
TUESDAY NIGHT ALLOWING THE FLOW TO BECOME SOUTHERLY. SOUTH TO
SOUTHWEST FLOW WILL THEN CONTINUE TILL A COLD FRONT CROSSES THE LAKE
AT THE VERY END OF THE PERIOD.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR
OHZ003-006>014-017>023-027>033-036>038-047-089.
PA...WIND ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST MONDAY FOR
PAZ001>003.
MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 4 PM EST MONDAY FOR
LEZ061-142>149-162>169.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
505 PM EST SUN NOV 17 2013
.SYNOPSIS...
A POTENT STORM SYSTEM WILL BE HEADED ACROSS THE UPPER MIDWEST AND
THROUGH THE GREAT LAKES TODAY AND TONIGHT. THIS WILL BRING A
STRONG COLD FRONT THROUGH THE REGION OVERNIGHT. COOLER AND
DRIER...BUT WINDY CONDITIONS WILL FOLLOW BEHIND THE FRONT ON
MONDAY...WITH HIGH PRESSURE RETURNING FAIR WEATHER TO THE AREA
INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE RADAR HASN`T CHANGED APPRECIABLY IN THE LAST SEVERAL HOURS
WITH GENERALLY LIGHT-MODERATE STRATIFORM RAINS CONTINUING OVER
ABOUT THE NWRN 1/2-2/3 OF MY FCST AREA. EXPECT THIS TO CONTINUE
INTO THE EVENING OUT AHEAD OF ALL THE MAIN ACTION THAT IS REALLY
GEARING UP NOW OVER ILLINOIS IN THE FORM OF A VIOLENT SQUALL LINE
THAT HAS ALREADY TRIGGERED SEVERAL DAMAGING TORNADOES.
THE LINE OF STORMS WILL CONTINUE EAST THIS EVENING AND EVENTUALLY
RACE ACROSS OUR AREA LATE THIS EVENING INTO THE WEE HOURS OF
MONDAY MORNING. INSTABILITY WILL AS USUAL BE LIMITED...BUT SHEAR
IS EXTREMELY STRONG. WHILE THE 15Z HRRR AND LATEST WRF RUNS
INDICATE A WEAKENING TREND AS THE LINE MOVES OUR WAY...IT STILL
LOOKS GOOD FOR ISOLATED STRONG WIND GUSTS ALONG AND JUST AHEAD OF
THE COLD FRONT.
BEST TIME FRAME FOR THE WORST OF THE WEATHER OVERNIGHT LOOKS TO BE
ABOUT 03-09Z WHEN THE BIGGEST PWATS AND LOW LEVEL WINDS SURGE
THROUGH THE AREA. 850 WINDS ARE PROGGED IN THE 50-70KT
RANGE...SOME 3-4STD ABOVE NORMAL. WE EXPECT THE LINE TO BRING
BRIEF DOWNPOURS AND THE INITIAL BLAST OF STRONG AND POSSIBLY
DAMAGING WIND GUSTS. THEN OVERALL GRADIENT WINDS SHOULD KICK IN
AND GUST IN THE 25-45MPH RANGE FOR A TIME. SHORT RANGE OPERATIONAL
MODELS ARE SHOWING A STRONG ISSALOBARIC SURGE BEHIND THE FRONT
SUPPORTING THE IDEA OF GUSTY POST FRONTAL WINDS...AT LEAST
THROUGH EARLY MONDAY MORNING WHEN THE STRONGEST WINDS SHOULD THEN
SHIFT OFF TO OUR NORTH AND NORTHEAST. A WIND ADVISORY HAS BEEN
ISSUED FOR LATER TONIGHT THROUGH EARLY MONDAY MORNING.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE COLD FRONT SHOULD BE EXITING THE COASTAL PLAIN BY 12Z
MONDAY...LEAVING PA IN A GUSTY WEST-SOUTHWEST FLOW.
TEMPERATURES...AT LEAST INITIALLY WILL NOT BE ALL THAT COLD
WITHIN THE NEW AIRMASS. ANY SHOWERS THAT DEVELOP AS THE COOLER AIR
MOVES OVER THE GREAT LAKES WILL ONLY GRADUALLY MIX WITH WET SNOW
BY THE END OF THE DAY OVER THE NW. THE BULK OF THE REST OF THE
REGION WILL ENJOY THE DRY SLOT...AND DESPITE BEING RATHER WINDY
WILL SEE HIGHS THAT WILL STILL AVERAGE SEVERAL DEG ABOVE NORMAL
FOR NOVEMBER OVER ALL BUT THE FAR NW.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
IN THE WAKE OF FRONTAL/TROF PASSAGE ON MONDAY...UPPER RIDGING WILL
DOMINATE THE MIDDLE ATLANTIC ON TUESDAY AND EARLY WEDNESDAY. UPPER
FLOW WILL THEN TURN SOUTHWESTHERLY THROUGH MUCH OF THE REMAINER OF
THE LONG TERM PERIOD AS A SRN STREAM UPPER LOW IS FORECAST TO
DEVELOP OVER SRN CALIFORNIA. A PRONOUNCED NORTHERN STREAM UPPER TROF
IS FORECAST TO DROP THROUGH THE GREAT LAKES LATE IN THE WEEK AND
TOWARDS PA NEXT WEEKEND.
AT THE SFC...HIGH PRESSURE...EXTENDING FROM NEW ENGLAND TO THE GULF
COAST...WILL DOMINATE MUCH OF WEEK. THIS WILL PROVIDE DRY WEATHER
WITH NEAR SEASONAL TEMPERATURES. THE LATE WEEK UPPER TROF WILL BRING
A COLD FRONT ACROSS PA ON SATURDAY WITH THE MOST SIGNIFICANT CHANCES
FOR PCPN DURING THIS FORECAST PD...NEXT SAT INTO SUNDAY.
TEMPERATURES WILL BE COLD ENOUGH FOR SNOW OR A MIX OF SNOW OR RAIN
OVER A GOOD PORTION OF THE CWA WITH THIS FROPA.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
ADJUSTMENTS MADE FOR CURRENT AND EXPECTED CONDITIONS.
EARLIER DISCUSSION BELOW.
WIDESPREAD REDUCED CIG/VIZ IN PLACE AT ALL TERMINALS EXCEPT JST
WHICH IS ON THE EDGE OF THE LOWER CLOUDS AND VIZ ASSOCIATED WITH
THE ADVANCING RAIN.
RADAR TRENDS INDICATE THE NW 1/2-2/3RDS OF THE AIRSPACE WILL SEE
SHOWERS INTO THE EVENING WITH WIDESPREAD IFR/MVFR CONTINUING
TONIGHT WILL BE A VERY ACTIVE PERIOD WITH A STRONG COLD FRONT AND
ATTENDANT LOW-TOPPED SQUALL LINE EXPECTED TO RACE EWD ACROSS THE
AIRSPACE. SOUTHERLY WINDS WILL STEADILY INCREASE AHEAD OF THE
FRONT WITH LLWS EXPECTED GIVEN 50+KT LOW LEVEL JET. MODERATE TO
HEAVY SHOWERS AND LOCAL HIGHER WIND GUSTS WILL BE POSSIBLE ALONG
AND IMMEDIATELY BEHIND THE SQUALL LINE WITH AN ABRUPT WIND SHIFT TO
THE WEST- SOUTHWEST. GUSTY WINDS WILL CONTINUE INTO EARLY MONDAY
WITH FQNT GUSTS IN THE 25-45MPH RANGE..ESPECIALLY OVER WESTERN
AREAS.
MONDAY WILL SEE RAPID IMPROVEMENT IN CEILING/VIZ AS THE FRONT
MOVES OUT OF THE REGION...BUT SOME LOCALLY REDUCED CONDITIONS WILL
BECOME POSSIBLE ONCE AGAIN OVER THE NW AS COOLER AIR BEGINS TO
SWEEP OVER THE GR LAKES AND BRING SOME SCATTERED RAIN/SNOW
SHOWERS. THE WIND WILL STAY GUSTY IN THE 20-35MPH
RANGE...GRADUALLY DIMINISHING IN THE AFTERNOON.
OUTLOOK...
TUE...MAINLY VFR...LOCALLY MVFR OVER THE NW WITH SCATTERED SNOW
SHOWERS.
WED-THU...NO SIG WX.
FRI...SHOWERS POSSIBLE...WITH NEXT FRONTAL SYSTEM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 PM THIS EVENING TO 8 AM EST MONDAY FOR
PAZ004>006-010>012-017>019-024-025-033-034-037-041-042-045-046.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...FITZGERALD/LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
424 PM EST SUN NOV 17 2013
.SYNOPSIS...
A POTENT STORM SYSTEM WILL BE HEADED ACROSS THE UPPER MIDWEST AND
THROUGH THE GREAT LAKES TODAY AND TONIGHT. THIS WILL BRING A
STRONG COLD FRONT THROUGH THE REGION OVERNIGHT. COOLER AND
DRIER...BUT WINDY CONDITIONS WILL FOLLOW BEHIND THE FRONT ON
MONDAY...WITH HIGH PRESSURE RETURNING FAIR WEATHER TO THE AREA
INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE RADAR HASN`T CHANGED APPRECIABLY IN THE LAST SEVERAL HOURS
WITH GENERALLY LIGHT-MODERATE STRATIFORM RAINS CONTINUING OVER
ABOUT THE NWRN 1/2-2/3 OF MY FCST AREA. EXPECT THIS TO CONTINUE
INTO THE EVENING OUT AHEAD OF ALL THE MAIN ACTION THAT IS REALLY
GEARING UP NOW OVER ILLINOIS IN THE FORM OF A VIOLENT SQUALL LINE
THAT HAS ALREADY TRIGGERED SEVERAL DAMAGING TORNADOES.
THE LINE OF STORMS WILL CONTINUE EAST THIS EVENING AND EVENTUALLY
RACE ACROSS OUR AREA LATE THIS EVENING INTO THE WEE HOURS OF
MONDAY MORNING. INSTABILITY WILL AS USUAL BE LIMITED...BUT SHEAR
IS EXTREMELY STRONG. WHILE THE 15Z HRRR AND LATEST WRF RUNS
INDICATE A WEAKENING TREND AS THE LINE MOVES OUR WAY...IT STILL
LOOKS GOOD FOR ISOLATED STRONG WIND GUSTS ALONG AND JUST AHEAD OF
THE COLD FRONT.
BEST TIME FRAME FOR THE WORST OF THE WEATHER OVERNIGHT LOOKS TO BE
ABOUT 03-09Z WHEN THE BIGGEST PWATS AND LOW LEVEL WINDS SURGE
THROUGH THE AREA. 850 WINDS ARE PROGGED IN THE 50-70KT
RANGE...SOME 3-4STD ABOVE NORMAL. WE EXPECT THE LINE TO BRING
BRIEF DOWNPOURS AND THE INITIAL BLAST OF STRONG AND POSSIBLY
DAMAGING WIND GUSTS. THEN OVERALL GRADIENT WINDS SHOULD KICK IN
AND GUST IN THE 25-45MPH RANGE FOR A TIME. SHORT RANGE OPERATIONAL
MODELS ARE SHOWING A STRONG ISSALOBARIC SURGE BEHIND THE FRONT
SUPPORTING THE IDEA OF GUSTY POST FRONTAL WINDS...AT LEAST
THROUGH EARLY MONDAY MORNING WHEN THE STRONGEST WINDS SHOULD THEN
SHIFT OFF TO OUR NORTH AND NORTHEAST. A WIND ADVISORY HAS BEEN
ISSUED FOR LATER TONIGHT THROUGH EARLY MONDAY MORNING.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE COLD FRONT SHOULD BE EXITING THE COASTAL PLAIN BY 12Z
MONDAY...LEAVING PA IN A GUSTY WEST-SOUTHWEST FLOW.
TEMPERATURES...AT LEAST INITIALLY WILL NOT BE ALL THAT COLD
WITHIN THE NEW AIRMASS. ANY SHOWERS THAT DEVELOP AS THE COOLER AIR
MOVES OVER THE GREAT LAKES WILL ONLY GRADUALLY MIX WITH WET SNOW
BY THE END OF THE DAY OVER THE NW. THE BULK OF THE REST OF THE
REGION WILL ENJOY THE DRY SLOT...AND DESPITE BEING RATHER WINDY
WILL SEE HIGHS THAT WILL STILL AVERAGE SEVERAL DEG ABOVE NORMAL
FOR NOVEMBER OVER ALL BUT THE FAR NW.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
IN THE WAKE OF FRONTAL/TROF PASSAGE ON MONDAY...UPPER RIDGING WILL
DOMINATE THE MIDDLE ATLANTIC ON TUESDAY AND EARLY WEDNESDAY. UPPER
FLOW WILL THEN TURN SOUTHWESTHERLY THROUGH MUCH OF THE REMAINER OF
THE LONG TERM PERIOD AS A SRN STREAM UPPER LOW IS FORECAST TO
DEVELOP OVER SRN CALIFORNIA. A PRONOUNCED NORTHERN STREAM UPPER TROF
IS FORECAST TO DROP THROUGH THE GREAT LAKES LATE IN THE WEEK AND
TOWARDS PA NEXT WEEKEND.
AT THE SFC...HIGH PRESSURE...EXTENDING FROM NEW ENGLAND TO THE GULF
COAST...WILL DOMINATE MUCH OF WEEK. THIS WILL PROVIDE DRY WEATHER
WITH NEAR SEASONAL TEMPERATURES. THE LATE WEEK UPPER TROF WILL BRING
A COLD FRONT ACROSS PA ON SATURDAY WITH THE MOST SIGNIFICANT CHANCES
FOR PCPN DURING THIS FORECAST PD...NEXT SAT INTO SUNDAY.
TEMPERATURES WILL BE COLD ENOUGH FOR SNOW OR A MIX OF SNOW OR RAIN
OVER A GOOD PORTION OF THE CWA WITH THIS FROPA.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD REDUCED CIG/VIZ IN PLACE AT ALL TERMINALS EXCEPT JST
WHICH IS ON THE EDGE OF THE LOWER CLOUDS AND VIZ ASSOCIATED WITH
THE ADVANCING RAIN.
RADAR TRENDS INDICATE THE NW 1/2-2/3RDS OF THE AIRSPACE WILL SEE
SHOWERS INTO THE EVENING WITH WIDESPREAD IFR/MVFR CONTINUING
TONIGHT WILL BE A VERY ACTIVE PERIOD WITH A STRONG COLD FRONT AND
ATTENDANT LOW-TOPPED SQUALL LINE EXPECTED TO RACE EWD ACROSS THE
AIRSPACE. SOUTHERLY WINDS WILL STEADILY INCREASE AHEAD OF THE
FRONT WITH LLWS EXPECTED GIVEN 50+KT LOW LEVEL JET. MODERATE TO
HEAVY SHOWERS AND LOCAL HIGHER WIND GUSTS WILL BE POSSIBLE ALONG
AND IMMEDIATELY BEHIND THE SQUALL LINE WITH AN ABRUPT WIND SHIFT TO
THE WEST- SOUTHWEST. GUSTY WINDS WILL CONTINUE INTO EARLY MONDAY
WITH FQNT GUSTS IN THE 25-45MPH RANGE..ESPECIALLY OVER WESTERN
AREAS.
MONDAY WILL SEE RAPID IMPROVEMENT IN CEILING/VIZ AS THE FRONT
MOVES OUT OF THE REGION...BUT SOME LOCALLY REDUCED CONDITIONS WILL
BECOME POSSIBLE ONCE AGAIN OVER THE NW AS COOLER AIR BEGINS TO
SWEEP OVER THE GR LAKES AND BRING SOME SCATTERED RAIN/SNOW
SHOWERS. THE WIND WILL STAY GUSTY IN THE 20-35MPH
RANGE...GRADUALLY DIMINISHING IN THE AFTERNOON.
OUTLOOK...
TUE...MAINLY VFR...LOCALLY MVFR OVER THE NW WITH SCATTERED SNOW
SHOWERS.
WED-THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 PM THIS EVENING TO 8 AM EST MONDAY FOR
PAZ004>006-010>012-017>019-024-025-033-034-037-041-042-045-046.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
141 PM EST SUN NOV 17 2013
.SYNOPSIS...
A POTENT STORM SYSTEM WILL BE HEADED ACROSS THE UPPER MIDWEST AND
THROUGH THE GREAT LAKES TODAY AND TONIGHT. THIS WILL BRING A
STRONG COLD FRONT THROUGH THE REGION OVERNIGHT. COOLER AND
DRIER...BUT WINDY CONDITIONS WILL FOLLOW BEHIND THE FRONT ON
MONDAY...WITH HIGH PRESSURE RETURNING FAIR WEATHER TO THE AREA
INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RADAR HASN`T CHANGED APPRECIABLY IN THE LAST SEVERAL HOURS
WITH GENERALLY LIGHT-MODERATE STRATIFORM RAINS CONTINUING OVER
ABOUT THE NWRN 1/2-2/3 OF MY FCST AREA. EXPECT THIS TO CONTINUE
INTO THE EVENING OUT AHEAD OF ALL THE MAIN ACTION THAT IS REALLY
GEARING UP NOW OVER ILLINOIS IN THE FORM OF A VIOLENT SQUALL LINE
THAT HAS ALREADY TRIGGERED SEVERAL DAMAGING TORNADOES.
THE LINE OF STORMS WILL CONTINUE EAST THIS EVENING AND EVENTUALLY
RACE ACROSS OUR AREA LATE THIS EVENING INTO THE WEE HOURS OF
MONDAY MORNING. INSTABILITY WILL AS USUAL BE LIMITED...BUT SHEAR
IS EXTREMELY STRONG. WHILE THE 15Z HRRR AND LATEST WRF RUNS
INDICATE A WEAKENING TREND AS THE LINE MOVES OUR WAY...IT STILL
LOOKS GOOD FOR ISOLATED STRONG WIND GUSTS ALONG AND JUST AHEAD OF
THE COLD FRONT.
BEST TIME FRAME FOR THE WORST OF THE WEATHER OVERNIGHT LOOKS TO BE
ABOUT 03-09Z WHEN THE BIGGEST PWATS AND LOW LEVEL WINDS SURGE
THROUGH THE AREA. 850 WINDS ARE PROGGED IN THE 50-70KT
RANGE...SOME 3-4STD ABOVE NORMAL. WE EXPECT THE LINE TO BRING
BRIEF DOWNPOURS AND THE INITIAL BLAST OF STRONG AND POSSIBLY
DAMAGING WIND GUSTS. THEN OVERALL GRADIENT WINDS SHOULD KICK IN
AND GUST IN THE 25-45MPH RANGE FOR A TIME. SHORT RANGE OPERATIONAL
MODELS ARE SHOWING A STRONG ISSALOBARIC SURGE BEHIND THE FRONT
SUPPORTING THE IDEA OF GUSTY POST FRONTAL WINDS...AT LEAST
THROUGH EARLY MONDAY MORNING WHEN THE STRONGEST WINDS SHOULD THEN
SHIFT OFF TO OUR NORTH AND NORTHEAST. A WIND ADVISORY HAS BEEN
ISSUED FOR LATER TONIGHT THROUGH EARLY MONDAY MORNING.
&&
.SHORT TERM /MONDAY/...
THE COLD FRONT SHOULD BE EXITING THE COASTAL PLAIN BY 12Z
MONDAY...LEAVING PA IN A GUSTY WEST-SOUTHWEST FLOW.
TEMPERATURES...AT LEAST INITIALLY WILL NOT BE ALL THAT COLD
WITHIN THE NEW AIRMASS. ANY SHOWERS THAT DEVELOP AS THE COOLER AIR
MOVES OVER THE GREAT LAKES WILL ONLY GRADUALLY MIX WITH WET SNOW
BY THE END OF THE DAY OVER THE NW. THE BULK OF THE REST OF THE
REGION WILL ENJOY THE DRY SLOT...AND DESPITE BEING RATHER WINDY
WILL SEE HIGHS THAT WILL STILL AVERAGE SEVERAL DEG ABOVE NORMAL
FOR NOVEMBER OVER ALL BUT THE FAR NW.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
SCATTERED LIGHT PRECIPITATION /INITIALLY IN THE FORM OF RAIN SHOWERS
DURING THE DAYLIGHT HOURS MONDAY...THEN EVENTUALLY SNOW SHOWERS BY
MONDAY NIGHT/...WILL AFFECT THE NORTHERN AND WESTERN MOUNTAINS OF
THE STATE. MINOR SNOW ACCUMS OF A COATING...TO PERHAPS AROUND 1 INCH
IN WARREN COUNTY...WILL OCCUR MONDAY NIGHT ACROSS THE MTNS. BIG
NEGATING FACTOR AGAINST ACCUMULATING OROGRAPHIC/LES SNOW SHOWERS
WILL BE THE RATHER SHALLOW DEPTH OF THE COLD AIR...AND CLOUD TEMPS
WARMER THAN -12C WHICH WILL GREATLY LIMIT THE INTENSITY AND
DENDRITIC GROWTH OF THE SNOW.
AFTER PASSAGE OF UPPER TROF AXIS MONDAY/EARLY TUESDAY...THE UPPER
FLOW PATTERN BECOMES FAIRLY ZONAL THROUGH THE REMAINDER OF THE
PERIOD AS ENERGY IS FORECAST TO DIG INTO THE WESTERN U.S. 00Z MODEL
GUIDANCE IS SOMEWHAT GOOD AGREEMENT ON A DRY AND SLOWLY MODERATING
PERIOD FOR THE SECOND HALF OF THE WEEK AS HIGH PRESSURE SLIDES OFF
THE SOUTHERN NEW ENGLAND COAST.
AN ARCTIC FRONT WILL PLOW SOUTHEAST ACROSS THE NORTHERN PLAINS AND
UPPER GLAKES FRIDAY...THANKS TO A HIGHLY AMPLIFIED RIDGE FORMING
ACROSS THE ERN PACIFIC AND INTO THE GULF OF ALASKA...WITH AN
EVENTUAL REX BLOCK PATTERN OVER THE WEST COAST OF CANADA AND
THE U.S.
INTERESTING SCENARIO SHAPING UP FOR NEXT WEEKEND WITH THE FIRST
POTENTIAL FOR A WIDESPREAD SYNOPTIC LIGHT TO MODERATE SNOW OR MIXED
PRECIP EVENT. 00Z GFS AND EC OPERATIONAL MODELS AND ENSEMBLE SUITES
DIVERGE SLIGHTLY BY NEXT WEEKEND WITH THE TRACK/ORIENTATION OF THE
ARCTIC FRONT...AND THE AMOUNT OF ENERGY DIGGING SOUTHEAST IN ITS
WAKE INTO THE MISS VALLEY AND APPALACHIANS.
HOWEVER...BOTH MODELS AND THEIR ENSEMBLES INDICATE A CLIPPER TYPE
SYSTEM HEADING SE ACROSS THE GLAKES...BRINGING US AT LEAST SOME
SNOW/OR SNOW SHOWERS /THAT COULD BE MIXED WITH RAIN ACROSS SOUTHERN
PENN FRIDAY NIGHT INTO EARLY SAT/. THE COLDEST AIR SO FAR THIS FALL
WILL LIKELY FOLLOW FOR LATER NEXT WEEKEND INTO THE WEEK OF NOV 25TH.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
WIDESPREAD REDUCED CIG/VIZ IN PLACE AT ALL TERMINALS EXCEPT JST
WHICH IS ON THE EDGE OF THE LOWER CLOUDS AND VIZ ASSOCIATED WITH
THE ADVANCING RAIN.
RADAR TRENDS INDICATE THE NW 1/2-2/3RDS OF THE AIRSPACE WILL SEE
SHOWERS INTO THE EVENING WITH WIDESPREAD IFR/MVFR CONTINUING
TONIGHT WILL BE A VERY ACTIVE PERIOD WITH A STRONG COLD FRONT AND
ATTENDANT LOW-TOPPED SQUALL LINE EXPECTED TO RACE EWD ACROSS THE
AIRSPACE. SOUTHERLY WINDS WILL STEADILY INCREASE AHEAD OF THE
FRONT WITH LLWS EXPECTED GIVEN 50+KT LOW LEVEL JET. MODERATE TO
HEAVY SHOWERS AND LOCAL HIGHER WIND GUSTS WILL BE POSSIBLE ALONG
AND IMMEDIATELY BEHIND THE SQUALL LINE WITH AN ABRUPT WIND SHIFT TO
THE WEST- SOUTHWEST. GUSTY WINDS WILL CONTINUE INTO EARLY MONDAY
WITH FQNT GUSTS IN THE 25-45MPH RANGE..ESPECIALLY OVER WESTERN
AREAS.
MONDAY WILL SEE RAPID IMPROVEMENT IN CEILING/VIZ AS THE FRONT
MOVES OUT OF THE REGION...BUT SOME LOCALLY REDUCED CONDITIONS WILL
BECOME POSSIBLE ONCE AGAIN OVER THE NW AS COOLER AIR BEGINS TO
SWEEP OVER THE GR LAKES AND BRING SOME SCATTERED RAIN/SNOW
SHOWERS. THE WIND WILL STAY GUSTY IN THE 20-35MPH
RANGE...GRADUALLY DIMINISHING IN THE AFTERNOON.
OUTLOOK...
TUE...MAINLY VFR...LOCALLY MVFR OVER THE NW WITH SCATTERED SNOW
SHOWERS.
WED-THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 PM THIS EVENING TO 8 AM EST MONDAY FOR
PAZ004>006-010>012-017>019-024-025-033-034-037-041-042-045-046.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
909 AM EST SUN NOV 17 2013
.SYNOPSIS...
THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST
AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH
PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 AM...WESTWARD EXPANSION OF THE DENSE FOG APPEARS TO HAVE
BEEN HALTED BY THE WARMING BOUNDARY LAYER NOW THAT THE SUN IS
GETTING A BIT HIGHER IN THE SKY...AND SOME THIN SPOTS ARE BEGINNING
TO APPEAR OVER THE PIEDMONT. HOWEVER...THE DENSE FOG ADVISORY RAN
OUT AT 14Z AND CONDITIONS WILL IMPROVE ONLY SLOWLY...SO IT WAS
EXTENDED THROUGH 16Z. TEMPS ARE IN DECENT SHAPE. EXPECT FREQUENT
UPDATES THROUGH THIS AFTERNOON.
PREVIOUS DISCUSSION...
AS OF 545 AM EST SUNDAY...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR
THE I-77 CORRIDOR. VSBYS HAVE BEEN STEADILY DECLINING AND A LARGE
AREA OF THE WRN PIEDMONT IS NOW DOWN TO A QUARTER MILE. THE ADVISORY
WAS RUN THROUGH 14 UTC. HOWEVER...THE LIGHT EASTERLY FLOW AND
INCREASING WARM ADVECTION ALOFT MAY HELP THE FOG TO HANG AROUND MOST
OF THE MORNING.
AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP
ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY
FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING
CHANCES OF SHOWER ACTIVITY OVER THE FORECAST AREA. SHOWER CHANCES
WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE
AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF
SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEING
FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS
RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE
IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY
ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT
DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING.
LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS
EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS
GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE
AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW
BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE
MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE
ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE
LOW. WHILE THE FORCING WILL BE STRONGER OVER WESTERN NC...THERE IS
HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY
ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT
MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL
WEAKEN CONSIDERABLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT
THE 00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A
WEAKENING LINE WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO
THE SFC AS IT MOVES ACROSS THE FOOTHILLS AND PIEDMONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER
TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE
SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE
NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND
THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR
MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN
A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE
NORMAL.
THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY
NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO
DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT
WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS
A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR
NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER
OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE
FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL.
THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD
TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC
MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE
NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS
IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH.
UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM
TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY.
HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON
BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS
HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE
NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A
VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY
NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL
AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A
COMPROMISE FROM THE DAYS 5 TO 7 MODELS.
THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF
ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD
OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE
NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND
NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL
THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY
INTO SATURDAY.
THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND
DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME
ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT
AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE
DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY
SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH
PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA.
THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY
EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE
GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL
CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF
INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN
OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS.
NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS
PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY.
TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND
SATURDAY.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AT KCLT...CLEAR SKIES EARLIER IN THE NIGHT SET THE STAGE FOR DENSE
FOG AT THE AIRFIELD. WITH WEAK WARM ADVECTION ALOFT...THIS IS THE
KIND OF FOG EVENT WHICH COULD LAST MOST OF THE MORNING. FOR NOW I
ONLY HAVE 1/4SM THROUGH 14 UTC AND 1/2SM TIL 15 UTC. THE DAY SHIFT
MAY NEED TO EXTEND THAT A FEW HOURS. CIGS SHOULD GRADUALLY LIFT INTO
THE AFTN BEFORE THEY FALL QUICKLY AGAIN THIS EVENING.
A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS
TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE
IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT
AND GUSTY WINDS SHOULD ACCOMPANY BNDRY ACROSS THE AIRFIELD. A WIND
SHIFT WAS NOT INCLUDED IN THIS ISSUANCE BUT BE AWARE THAT THE BNDRY
IS EXPECTED TO ARRIVE RIGHT AROUND 12 UTC...OR POSSIBLY AN HOUR OR 2
BEFORE.
ELSEWHERE...IFR OR LIFR CIGS HAVE DEVELOPED AT KHKY AND KAVL AND THE
CIGS WILL BE SLOW TO LIFT. IN FACT BOTH THE CIGS AND VSBYS MAY
BECOME WORSE OVER THE NEXT COUPLE HOURS. IFR CIGS WERE BEGINNING TO
DEVELOP OVER THE UPSTATE A LITTLE BEFORE 12 UTC. BASED ON MODEL
SOUNDINGS AND THE GENERAL SET UP THIS MORNING I EXPECT THAT IFR CIGS
WILL SOON COVER ALL THE UPSTATE WITH IFR CONDITIONS LASTING THROUGH
NOON. HOPEFULLY THERE WILL BE ENOUGH MIXING TO KEEP THE AREAS OF
DENSE FOG EAST OF THE UPSTATE AIRFIELDS THIS MORNING.
SCATTERED SHOWERS WILL BECOME MORE WIDESPREAD THIS AFTERNOON. A LINE
OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS BETWEEN 06-09
UTC. WINDS SHOULD SHIFT AT KAVL AROUND OR A LITTLE BEFORE 09 UTC.
NOT SURE IF THE LINE WILL STILL BE PRODUCING LIGHTNING BY THE TIME
IT HITS KAVL...BUT THERE SHOULD BE GUSTY NW WINDS. THE LINE SHOULD
FURTHER WEAKEN AS IT MOVES OUT OF THE MTNS...BUT A SHARP WIND SHIFT
IS LIKELY TO AFFECT ALL OF THE TAF SITES BETWEEN 09-12 UTC.
OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY.
CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE
OF THE UPCOMING WEEK.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT MED 63% HIGH 94% HIGH 87% HIGH 97%
KGSP HIGH 86% HIGH 87% HIGH 100% HIGH 87%
KAVL MED 75% HIGH 91% HIGH 87% HIGH 95%
KHKY HIGH 91% HIGH 87% HIGH 96% HIGH 82%
KGMU HIGH 86% MED 79% HIGH 100% HIGH 97%
KAND HIGH 83% HIGH 87% HIGH 93% HIGH 82%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH
CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD
WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW
BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR
NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN
BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG
WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR NCZ033-
035>037-056-057-068>072-082-501>504.
SC...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR SCZ009-014.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY/PM
SHORT TERM...JAT
LONG TERM...DEO
AVIATION...MCAVOY
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
816 AM EST SUN NOV 17 2013
.SYNOPSIS...
THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST
AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH
PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 8 AM...DENSE FOG CONTINUES TO OOZE ITS WAY WESTWARD TOWARD THE
BLUE RIDGE. HAVE ADDED ANOTHER STRIPE OF ZONES TO THE DENSE FOG
ADVISORY TO ACCOUNT FOR VISIBILITY DROPPING DOWN TO 1/4 MILE FROM
GASTONIA TO LINCOLNTON AND HICKORY. INCLUDED THE AREA AROUND THE
TABLE ROCK FIRE AS WELL. RADAR NOT DETECTING ANY PRECIP YET ACROSS
THE WESTERN CAROLINAS...SO THE PRECIP CHANCES WERE PUSHED BACK A FEW
HOURS TOWARD MIDDAY. TEMPS WERE ALSO ADJUSTED. EXPECT FREQUENT
UPDATES TODAY.
PREVIOUS DISCUSSION...
AS OF 545 AM EST SUNDAY...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR
THE I-77 CORRIDOR. VSBYS HAVE BEEN STEADILY DECLINING AND A LARGE
AREA OF THE WRN PIEDMONT IS NOW DOWN TO A QUARTER MILE. THE ADVISORY
WAS RUN THROUGH 14 UTC. HOWEVER...THE LIGHT EASTERLY FLOW AND
INCREASING WARM ADVECTION ALOFT MAY HELP THE FOG TO HANG AROUND MOST
OF THE MORNING.
AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP
ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY
FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING
CHANCES OF SHOWER ACTIVITY OVER THE FORECAST AREA. SHOWER CHANCES
WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE
AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF
SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEING
FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS
RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE
IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY
ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT
DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING.
LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS
EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS
GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE
AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW
BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE
MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE
ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE
LOW. WHILE THE FORCING WILL BE STRONGER OVER WESTERN NC...THERE IS
HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY
ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT
MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL
WEAKEN CONSIDERABLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT
THE 00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A
WEAKENING LINE WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO
THE SFC AS IT MOVES ACROSS THE FOOTHILLS AND PIEDMONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER
TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE
SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE
NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND
THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR
MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN
A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE
NORMAL.
THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY
NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO
DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT
WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS
A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR
NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER
OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE
FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL.
THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD
TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC
MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE
NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS
IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH.
UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM
TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY.
HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON
BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS
HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE
NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A
VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY
NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL
AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A
COMPROMISE FROM THE DAYS 5 TO 7 MODELS.
THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF
ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD
OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE
NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND
NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL
THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY
INTO SATURDAY.
THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND
DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME
ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT
AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE
DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY
SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH
PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA.
THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY
EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE
GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL
CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF
INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN
OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS.
NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS
PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY.
TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND
SATURDAY.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
AT KCLT...CLEAR SKIES EARLIER IN THE NIGHT SET THE STAGE FOR DENSE
FOG AT THE AIRFIELD. WITH WEAK WARM ADVECTION ALOFT...THIS IS THE
KIND OF FOG EVENT WHICH COULD LAST MOST OF THE MORNING. FOR NOW I
ONLY HAVE 1/4SM THROUGH 14 UTC AND 1/2SM TIL 15 UTC. THE DAY SHIFT
MAY NEED TO EXTEND THAT A FEW HOURS. CIGS SHOULD GRADUALLY LIFT INTO
THE AFTN BEFORE THEY FALL QUICKLY AGAIN THIS EVENING.
A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS
TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE
IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT
AND GUSTY WINDS SHOULD ACCOMPANY BNDRY ACROSS THE AIRFIELD. A WIND
SHIFT WAS NOT INCLUDED IN THIS ISSUANCE BUT BE AWARE THAT THE BNDRY
IS EXPECTED TO ARRIVE RIGHT AROUND 12 UTC...OR POSSIBLY AN HOUR OR 2
BEFORE.
ELSEWHERE...IFR OR LIFR CIGS HAVE DEVELOPED AT KHKY AND KAVL AND THE
CIGS WILL BE SLOW TO LIFT. IN FACT BOTH THE CIGS AND VSBYS MAY
BECOME WORSE OVER THE NEXT COUPLE HOURS. IFR CIGS WERE BEGINNING TO
DEVELOP OVER THE UPSTATE A LITTLE BEFORE 12 UTC. BASED ON MODEL
SOUNDINGS AND THE GENERAL SET UP THIS MORNING I EXPECT THAT IFR CIGS
WILL SOON COVER ALL THE UPSTATE WITH IFR CONDITIONS LASTING THROUGH
NOON. HOPEFULLY THERE WILL BE ENOUGH MIXING TO KEEP THE AREAS OF
DENSE FOG EAST OF THE UPSTATE AIRFIELDS THIS MORNING.
SCATTERED SHOWERS WILL BECOME MORE WIDESPREAD THIS AFTERNOON. A LINE
OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS BETWEEN 06-09
UTC. WINDS SHOULD SHIFT AT KAVL AROUND OR A LITTLE BEFORE 09 UTC.
NOT SURE IF THE LINE WILL STILL BE PRODUCING LIGHTNING BY THE TIME
IT HITS KAVL...BUT THERE SHOULD BE GUSTY NW WINDS. THE LINE SHOULD
FURTHER WEAKEN AS IT MOVES OUT OF THE MTNS...BUT A SHARP WIND SHIFT
IS LIKELY TO AFFECT ALL OF THE TAF SITES BETWEEN 09-12 UTC.
OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY.
CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE
OF THE UPCOMING WEEK.
CONFIDENCE TABLE...
13-19Z 19-01Z 01-07Z 07-13Z
KCLT MED 68% HIGH 89% MED 76% HIGH 94%
KGSP HIGH 81% HIGH 91% HIGH 90% HIGH 87%
KAVL MED 64% HIGH 91% HIGH 85% HIGH 88%
KHKY HIGH 91% HIGH 91% HIGH 85% HIGH 82%
KGMU HIGH 81% HIGH 83% HIGH 93% HIGH 96%
KAND MED 77% HIGH 91% HIGH 85% HIGH 83%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH
CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD
WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW
BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR
NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN
BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG
WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ033-
035>037-056-057-068>072-082-501>504.
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ009-014.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY/PM
SHORT TERM...JAT
LONG TERM...DEO
AVIATION...MCAVOY
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
646 AM EST SUN NOV 17 2013
.SYNOPSIS...
THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST
AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH
PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 545 AM EST SUNDAY...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR
THE I-77 CORRIDOR. VSBYS HAVE BEEN STEADILY DECLINING AND A LARGE
AREA OF THE WRN PIEDMONT IS NOW DOWN TO A QUARTER MILE. THE ADVISORY
WAS RUN THROUGH 14 UTC. HOWEVER...THE LIGHT EASTERLY FLOW AND
INCREASING WARM ADVECTION ALOFT MAY HELP THE FOG TO HANG AROUND MOST
OF THE MORNING.
AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP
ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY
FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING
CHANCES OF SHOWER ACTIVITY OVER THE FORECAST AREA. SHOWER CHANCES
WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE
AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF
SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEING
FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS
RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE
IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY
ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT
DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING.
LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS
EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS
GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE
AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW
BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE
MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE
ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE
LOW. WHILE THE FORCING WILL BE STRONGER OVER WESTERN NC...THERE IS
HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY
ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT
MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL
WEAKEN CONSIDERABLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT
THE 00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A
WEAKENING LINE WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO
THE SFC AS IT MOVES ACROSS THE FOOTHILLS AND PIEDMONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER
TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE
SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE
NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND
THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR
MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN
A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE
NORMAL.
THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY
NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO
DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT
WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS
A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR
NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER
OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE
FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL.
THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD
TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC
MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE
NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS
IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH.
UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM
TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY.
HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON
BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS
HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE
NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A
VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY
NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL
AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A
COMPROMISE FROM THE DAYS 5 TO 7 MODELS.
THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF
ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD
OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE
NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND
NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL
THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY
INTO SATURDAY.
THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND
DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME
ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT
AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE
DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY
SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH
PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA.
THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY
EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE
GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL
CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF
INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN
OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS.
NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS
PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY.
TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND
SATURDAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AT KCLT...CLEAR SKIES EARLIER IN THE NIGHT SET THE STAGE FOR DENSE
FOG AT THE AIRFIELD. WITH WEAK WARM ADVECTION ALOFT...THIS IS THE
KIND OF FOG EVENT WHICH COULD LAST MOST OF THE MORNING. FOR NOW I
ONLY HAVE 1/4SM THROUGH 14 UTC AND 1/2SM TIL 15 UTC. THE DAY SHIFT
MAY NEED TO EXTEND THAT A FEW HOURS. CIGS SHOULD GRADUALLY LIFT INTO
THE AFTN BEFORE THEY FALL QUICKLY AGAIN THIS EVENING.
A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS
TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE
IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT
AND GUSTY WINDS SHOULD ACCOMPANY BNDRY ACROSS THE AIRFIELD. A WIND
SHIFT WAS NOT INCLUDED IN THIS ISSUANCE BUT BE AWARE THAT THE BNDRY
IS EXPECTED TO ARRIVE RIGHT AROUND 12 UTC...OR POSSIBLY AN HOUR OR 2
BEFORE.
ELSEWHERE...IFR OR LIFR CIGS HAVE DEVELOPED AT KHKY AND KAVL AND THE
CIGS WILL BE SLOW TO LIFT. IN FACT BOTH THE CIGS AND VSBYS MAY
BECOME WORSE OVER THE NEXT COUPLE HOURS. IFR CIGS WERE BEGINNING TO
DEVELOP OVER THE UPSTATE A LITTLE BEFORE 12 UTC. BASED ON MODEL
SOUNDINGS AND THE GENERAL SET UP THIS MORNING I EXPECT THAT IFR CIGS
WILL SOON COVER ALL THE UPSTATE WITH IFR CONDITIONS LASTING THROUGH
NOON. HOPEFULLY THERE WILL BE ENOUGH MIXING TO KEEP THE AREAS OF
DENSE FOG EAST OF THE UPSTATE AIRFIELDS THIS MORNING.
SCATTERED SHOWERS WILL BECOME MORE WIDESPREAD THIS AFTERNOON. A LINE
OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS BETWEEN 06-09
UTC. WINDS SHOULD SHIFT AT KAVL AROUND OR A LITTLE BEFORE 09 UTC.
NOT SURE IF THE LINE WILL STILL BE PRODUCING LIGHTNING BY THE TIME
IT HITS KAVL...BUT THERE SHOULD BE GUSTY NW WINDS. THE LINE SHOULD
FURTHER WEAKEN AS IT MOVES OUT OF THE MTNS...BUT A SHARP WIND SHIFT
IS LIKELY TO AFFECT ALL OF THE TAF SITES BETWEEN 09-12 UTC.
OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY.
CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE
OF THE UPCOMING WEEK.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT LOW 54% HIGH 87% MED 74% HIGH 82%
KGSP HIGH 80% HIGH 93% HIGH 81% HIGH 93%
KAVL LOW 57% HIGH 96% HIGH 84% HIGH 80%
KHKY HIGH 88% HIGH 100% MED 78% HIGH 84%
KGMU MED 78% HIGH 87% HIGH 81% HIGH 97%
KAND MED 66% HIGH 96% MED 74% HIGH 88%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH
CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD
WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW
BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR
NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN
BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG
WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ036-037-
057-071-072-082.
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ009-014.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY
SHORT TERM...JAT
LONG TERM...DEO
AVIATION...MCAVOY
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
631 AM EST SUN NOV 17 2013
.SYNOPSIS...
THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST
AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH
PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 545 AM EST SUNDAY...A DENSE FOG ADVISORY HAS BEEN ISSUED FOR
THE I-77 CORRIDOR. VSBYS HAVE BEEN STEADILY DECLINING AND A LARGE
AREA OF THE WRN PIEDMONT IS NOW DOWN TO A QUARTER MILE. THE ADVISORY
WAS RUN THROUGH 14 UTC. HOWEVER...THE LIGHT EASTERLY FLOW AND
INCREASING WARM ADVECTION ALOFT MAY HELP THE FOG TO HANG AROUND MOST
OF THE MORNING.
AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP
ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY
FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING
CHANCES OF SHOWER ACTIVITY OVER THE FORECAST AREA. SHOWER CHANCES
WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE
AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF
SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEING
FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS
RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE
IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY
ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT
DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING.
LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS
EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS
GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE
AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW
BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE
MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE
ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE
LOW. WHILE THE FORCING WILL BE STRONGER OVER WESTERN NC...THERE IS
HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY
ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT
MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL
WEAKEN CONSIDERABLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT
THE 00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A
WEAKENING LINE WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO
THE SFC AS IT MOVES ACROSS THE FOOTHILLS AND PIEDMONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER
TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE
SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE
NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND
THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR
MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN
A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE
NORMAL.
THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY
NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO
DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT
WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS
A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR
NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER
OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE
FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL.
THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD
TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC
MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE
NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS
IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH.
UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM
TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY.
HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON
BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS
HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE
NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A
VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY
NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL
AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A
COMPROMISE FROM THE DAYS 5 TO 7 MODELS.
THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF
ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD
OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE
NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND
NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL
THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY
INTO SATURDAY.
THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND
DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME
ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT
AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE
DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY
SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH
PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA.
THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY
EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE
GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL
CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF
INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN
OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS.
NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS
PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY.
TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND
SATURDAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AT KCLT...SKIES HAVE CLEARED TEMPORARILY AT THE AIRFIELD. JUST A FEW
MILES TO THE WEST THERE IS AN BORDERLINE MVFR/VFR DECK. JUST A FEW
MILES TO THE EAST THERE IS AN EXPANDING AREA OF FOG AND IFR/LIFR
STRATUS AND FOG. BASED ON THE H8 DRYING SEEN ON THE LATEST NAM AND
RUC...WENT WITH TEMPO IFR VSBYS AND LIFR CIGS. ONCE A HIGHER DECK
FINALLY SPREADS BACK IN HOPEFULLY THE LOWER STUFF WILL LIFT FOR A
WHILE. THAT SAID...IFR CIGS ARE EXPECTED TO DEVELOP AGAIN TOWARD 12
UTC AND LAST THROUGH THE MORNING. WINDS WILL BE LIGHT AND VARIABLE
THROUGH THE MORNING HOURS.
A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS
TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE
IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT
AND GUSTY WINDS MAY ACCOMPANY THE OUTFLOW BNDRY TOWARD MONDAY
MORNING. THIS IS A LITTLE OUTSIDE THE VALID PERIOD OF THE TAF...BUT
IT/S SOMETHING TO WATCH CLOSELY.
ELSEWHERE...VFR CIGS ARE CURRENTLY OVER ALL THE REMAINING TAF SITES.
STRENGTHENING UPSLOPE FLOW WILL HELP THESE CIGS TO GRADUALLY LOWER
DURING THE NIGHT. EXPECT THAT AN MVFR CIG WILL DEVELOP FIRST AROUND
2500 FEET WITH IFR STRATUS DEVELOPING TOWARD MORNING. THE LOW CIGS
ARE THEN EXPECTED TO LAST A LITTLE PAST NOON. SHOWERS WILL BECOME
MORE WIDESPREAD THIS EVENING. A LINE OF THUNDERSTORMS IS EXPECTED TO
ENTER THE MOUNTAINS BETWEEN 06-09 UTC. THE LINE MAY AFFECT KAVL.
EVEN IF THE STORMS WEAKEN...A SHARP WIND SHIFT IS LIKELY TO AFFECT
ALL OF THE TAF SITES A LITTLE BEYOND THE VALID PERIOD OF THE CURRENT
SET OF TAFS.
OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY.
CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE
OF THE UPCOMING WEEK.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT LOW 54% HIGH 87% MED 74% HIGH 82%
KGSP HIGH 80% HIGH 93% HIGH 81% HIGH 93%
KAVL LOW 57% HIGH 96% HIGH 84% HIGH 80%
KHKY HIGH 88% HIGH 100% MED 78% HIGH 84%
KGMU MED 78% HIGH 87% HIGH 81% HIGH 97%
KAND MED 66% HIGH 96% MED 74% HIGH 88%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH
CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD
WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW
BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR
NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN
BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG
WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ036-037-
057-071-072-082.
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ009-014.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY
SHORT TERM...JAT
LONG TERM...DEO
AVIATION...MCAVOY
FIRE WEATHER...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
250 AM EST SUN NOV 17 2013
.SYNOPSIS...
THE NEXT COLD FRONT IS EXPECTED TO PUSH THROUGH THE FORECAST
AREA SUNDAY NIGHT INTO EARLY MONDAY...FOLLOWED BY COLD CANADIAN HIGH
PRESSURE BUILDING OVER THE REGION THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 AM EST SUNDAY...A STRONG SHORT WAVE TROUGH WILL SWEEP
ACROSS THE UPPER MID-WEST THIS EVENING. INCREASING SOUTHWESTERLY
FLOW AHEAD OF A POTENT UPPER TROUGH WILL RESULT IN INCREASING
CHANCES OF SHOWER ACTIVITY OVER THE FOREAST AREA. SHOWER CHANCES
WILL BE MAINLY CONFINED TO THE BLUE RIDGE THIS MORNING. BY THE
AFTERNOON THE GFS...SPC 4KM WRF AND THE RAP ALL BRING AN AREA OF
SHOWERS ACROSS THE UPSTATE AND NORTHEAST GEORGIA. THE PCPN IS BEGING
FORCED BY STRONG LLVL WARM ADVECTION. THIS SEAMS REASONABLE AND POPS
RAMP UP QUICKLY EAST OF THE MOUNTAINS INTO THE AFTERNOON HOURS. CAPE
IS LIMITED AND THE ACTIVITY LOOKS AS THROUGH IT MAY BE SLIGHTLY
ELEVATED IN NATURE. SO WHILE THE THERE A CHANCE FOR A TSTM...IT
DOESN/T APPEAR THAT THERE IS ANY SEVERE RISK TODAY OR THIS EVENING.
LATER TONIGHT...HOWEVER...A STRONGLY FORCED LINE OF STORMS IS
EXPECTED TO SWEEP INTO THE NC MOUNTAINS. CONVECTIVE ALLOWING MODELS
GENERALLY HAVE THIS LINE ENTERING THE MOUNTAINS AROUND...OR A LITTLE
AFTER...06 UTC OR AROUND 1 AM. THERE IS DEEP UNIDIRECTIONAL FLOW
BEHIND THE LINE AND IT SHOULD BE MOVING QUITE FAST. EAST OF THE
MOUNTAINS THE NAM HAS A FAIR AMOUNT OF ELEVATED INSTABILITY...ON THE
ORDER OF 500-700 J/KG...THOUGH SURFACE BASED INSTABILITY IS QUITE
LOW. WHILE THE FORECING WILL BE STRONGER OVER WESTERN NC...THERE IS
HIGHER INSTABILITY SOUTH OF THE APPALACHIANS. THEREFORE THE LINE MAY
ACTUALLY HAVE A BETTER CHANCE OF PRODUCING SEVERE WEATHER AS IT
MOVES ACROSS NE GEORGIA AND THE WRN UPSTATE. I SUSPECT THE LINE WILL
WEAKEN CONSIDERLY AFTER CROSSING THE MOUNTAINS...MUCH LIKE WHAT THE
00 UTC HIGH RES WRF ARW IS INDICATING. HOWEVER...EVEN A WEAKING LINE
WILL HAVE THE POTENTIAL TO TRANSLATE STRONG WINDS TO THE SFC AS IT
MOVES ACROSS THE FOOTHILLS AND PIEDMONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AT 210 AM EST SUNDAY...ON MONDAY MORNING A LOW AMPLITUDE UPPER
TROUGH WILL EXTEND FROM THE GREAT LAKES TO THE GULF STATES. AT THE
SAME TIME...A SURFACE COLD FRONT WILL EXTEND FROM CAPE COD...TO THE
NC OUTER BANKS...TO SOMEWHERE BETWEEN THE SC AND GA PIEDMONT...AND
THE SC AND GA COAST. THE FRONT WILL RAPIDLY MOVE AWAY FROM OUR
MONDAY MORNING...FOLLOWED BY A DRY...NW...WARMING DOWNSLOPE FLOW IN
A TIGHT PRESSURE GRADIENT...AND TEMPERATURES ALMOST 10 DEGREES ABOVE
NORMAL.
THE DEAMPLIFYING UPPER TROUGH WILL MOVE OFFSHORE ON MONDAY
NIGHT...FOLLOWED BY ZONAL FLOW ALOFT. SURFACE WINDS WILL BE SLOW TO
DIMINISH MONDAY NIGHT AS HIGH PRESSURE MOVES UP THE OH VALLEY...BUT
WINDS WILL VEER FROM NW TO N...DECREASING DOWNSLOPE FLOW WARMING. AS
A RESULT..MINIMUM TEMPERATURES MONDAY NIGHT WILL FALL TO NEAR
NORMAL. TUESDAY FEATURES DRY HIGH PRESSURE CENTERED OVER THE UPPER
OH RIVER VALLEY...AND A WEAK PRESSURE GRADIENT TO ITS SOUTH. COOL NE
FLOW WILL LIMIT MAXIMUM TEMPERATURES TO SEVERAL DEGREES BELOW NORMAL.
THE SURFACE HIGH WILL TAKE UP RESIDENCE ALONG THE EASTERN SEABOARD
TUESDAY NIGHT. BOTH THE NAM AND GFS SHOW SOME ADVANCE OF ATLANTIC
MOISTURE INLAND OVER COASTAL SC AND GA...WITH THE NAM MOISTURE
NEATLY REACHING THE UPPER SAVANNAH RIVER VALLEY. THE ECMWF SPREADS
IT MOISTURE FARTHER INLAND LIKE THE NAM...BUT IS FARTHER SOUTH.
UNLESS CLOUD COVER CAN MAKE INROADS OVER OUR AREA...MINIMUM
TEMPERATURES TUESDAY NIGHT WILL BE SEVERAL CATEGORIES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 145 AM EST SUNDAY...FOR THE PERIOD WEDNESDAY THROUGH SATURDAY.
HIGH PRESSURE IS SHOWN TO BE OVER NEW YORK STATE AT 12Z WEDNESDAY ON
BOTH THE GFS AND ECMWF. THIS WILL GIVE OUR REGION A COOL NE FLOW AS
HIGHS WILL BE ABOUT 10 DEGREES BELOW NORMAL. THE HIGH SHIFTS OFF THE
NEW ENGLAND COAST WITH THE LOW LEVEL WIND FLOW CHANGING FROM NE TO A
VERY LIGHT VARIABLE OR LIGHT EAST FLOW. WEDNESDAY AND WEDNESDAY
NIGHT ARE THE PERIODS IN THIS MEDIUM RANGE THAT HAS BEST MODEL
AGREEMENT. THE REST OF THE FORECAST PERIODS ARE BASED ON A
COMPROMISE FROM THE DAYS 5 TO 7 MODELS.
THE PREVIOUS CANADIAN MODEL HAD A LOW MOVING NE OUT OF THE NRN GULF
ON THURSDAY INTO FRIDAY BRINGING RAIN TO GA AND THE CAROLINAS AHEAD
OF THE FRONT. NONE OF THE OTHER MODELS HAD ANYTHING LIKE THIS. THE
NEWEST CANADIAN HAS BACKED OFF FROM THE LOW AHEAD OF THE FRONT AND
NOW HAS CONVECTION FORMING ALONG GULF COAST FROM TEXAS TO AL
THURSDAY NIGHT AND MOVING IT NORTH TO JOIN THE FRONT LATE FRIDAY
INTO SATURDAY.
THE GFS MAINTAINS SOME WEAK SURFACE RIDGING OVER THE CAROLINAS AND
DELAYS THE COLD FRONT ARRIVING UNTIL SATURDAY. THE GFS HAS SOME
ORGANIZED SHOWER ACTIVITY MOVING INTO THE NC MTNS LATE FRIDAY NIGHT
AND THEN ALL ACTIVITY BREAKS DOWN SATURDAY AS THE FRONT BECOMES MORE
DIFFUSE. IN FACT...THE GFS HAS ALL PRECIP SOUTH OF OUR AREA BY
SATURDAY EVENING WITH DRY AIR SPREADING IN AHEAD OF COLD HIGH
PRESSURE WHICH ORIGINATES FROM ALASKA AND NW CANADA.
THE CURRENT ECMWF HAS PRECIP MOVING INTO THE GREAT SMOKIES THURSDAY
EVENING THEN EXPANDING OVER THE REST OF THE WESTERN CAROLINAS AND NE
GA FRIDAY INTO SATURDAY. THIS RUN OF THE ECMWF MAINTAINS FRONTAL
CONVECTION AS IT CROSSES THE AREA SATURDAY NIGHT WITH AROUND A HALF
INCH QPF. DRY AIR ARRIVES ON SUNDAY ON THE ECMWF. THE NEWEST 00Z RUN
OF THE ECMWF JUST ARRIVED AND IT IS VERY MUCH CLOSER TO THE GFS.
NEWEST RUN HAS A WEAK FRONTAL BAND CROSSING MTNS 12Z SAT AND ACROSS
PIEDMONT 18Z SATURDAY...THEN DRY AIR ALL OVER BY 00Z SUNDAY.
TEMPERATURES WILL BE CLOSE TO OR JUST BELOW NORMALS FRIDAY AND
SATURDAY.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AT KCLT...SKIES HAVE CLEARED TEMPORARILY AT THE AIRFIELD. JUST A FEW
MILES TO THE WEST THERE IS AN BORDERLINE MVFR/VFR DECK. JUST A FEW
MILES TO THE EAST THERE IS AN EXPANDING AREA OF FOG AND IFR/LIFR
STRATUS AND FOG. BASED ON THE H8 DRYING SEEN ON THE LATEST NAM AND
RUC...WENT WITH TEMPO IFR VSBYS AND LIFR CIGS. ONCE A HIGHER DECK
FINALLY SPREADS BACK IN HOPEFULLY THE LOWER STUFF WILL LIFT FOR A
WHILE. THAT SAID...IFR CIGS ARE EXPECTED TO DEVELOP AGAIN TOWARD 12
UTC AND LAST THROUGH THE MORNING. WINDS WILL BE LIGHT AND VARIABLE
THROUGH THE MORNING HOURS.
A LINE OF THUNDERSTORMS IS EXPECTED TO ENTER THE MOUNTAINS
TONIGHT...BUT AT THIS TIME IT DOESN/T APPEAR THE LINE WILL SURVIVE
IT/S TRIP ACROSS THE HIGH TERRAIN. STILL...A SIGNIFICANT WIND SHIFT
AND GUSTY WINDS MAY ACCOMPANY THE OUTFLOW BNDRY TOWARD MONDAY
MORNING. THIS IS A LITTLE OUTSIDE THE VALID PERIOD OF THE TAF...BUT
IT/S SOMETHING TO WATCH CLOSELY.
ELSEWHERE...VFR CIGS ARE CURRENTLY OVER ALL THE REMAINING TAF SITES.
STRENGTHENING UPSLOPE FLOW WILL HELP THESE CIGS TO GRADUALLY LOWER
DURING THE NIGHT. EXPECT THAT AN MVFR CIG WILL DEVELOP FIRST AROUND
2500 FEET WITH IFR STRATUS DEVELOPING TOWARD MORNING. THE LOW CIGS
ARE THEN EXPECTED TO LAST A LITTLE PAST NOON. SHOWERS WILL BECOME
MORE WIDESPREAD THIS EVENING. A LINE OF THUNDERSTORMS IS EXPECTED TO
ENTER THE MOUNTAINS BETWEEN 06-09 UTC. THE LINE MAY AFFECT KAVL.
EVEN IF THE STORMS WEAKEN...A SHARP WIND SHIFT IS LIKELY TO AFFECT
ALL OF THE TAF SITES A LITTLE BEYOND THE VALID PERIOD OF THE CURRENT
SET OF TAFS.
OUTLOOK...A RETURN TO MUCH DRIER WEATHER IS EXPECTED BY LATE MONDAY.
CONDITIONS SHOULD BE MAINLY VFR FROM MONDAY NIGHT THROUGH THE MIDDLE
OF THE UPCOMING WEEK.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-07Z
KCLT LOW 59% MED 73% MED 79% MED 75%
KGSP MED 72% MED 69% HIGH 83% HIGH 90%
KAVL HIGH 94% MED 77% HIGH 85% HIGH 91%
KHKY HIGH 86% HIGH 82% HIGH 88% HIGH 93%
KGMU MED 71% MED 67% MED 77% HIGH 86%
KAND MED 65% MED 63% HIGH 85% HIGH 86%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH
CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD
WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW
BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR
NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN
BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG
WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY
SHORT TERM...JAT
LONG TERM...DEO
AVIATION...MCAVOY
FIRE WEATHER...MCAVOY
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
554 AM CST SUN NOV 17 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 412 AM CST SUN NOV 17 2013
ON THE BIG PICTURE EARLY THIS MORNING...DEEP TROUGH THROUGH THE
PLAINS STATES WITH STRONG JET ENERGY JET GETTING READY TO BOTTOM OUT
AND SWING NORTHEAST THROUGH THE OHIO VALLEY TODAY. MAIN SURFACE LOW
PRESSURE STARTING TO WIND UP ACROSS NORTHEAST KANSAS...WITH
REFLECTION OF UPPER TROUGH EXTENDING BACK INTO SOUTHWEST SOUTH
DAKOTA. LEADING WAVE LIFTING/WEAKENING THROUGH NORTHERN MINNESOTA...
WITH BACKWASH OF STRATUS ACROSS NORTHERN MINNESOTA/EASTERN NORTH
DAKOTA...EXTENDING INTO EAST CENTRAL SOUTH DAKOTA. SMALLER POCKET OF
STRATUS/FOG SLIPPING SOUTHWARD TOWARD KFSD AREA ALONG I29...WITH
EVEN A FEW 1/4 TO 1/2SM VISIBILITIES NOTED ALONG LEADING EDGE.
MANY SUBTLE ELEMENTS TO FORECAST OVER THE NEXT 12 TO 24 HOURS...
BUT FOR THE MOST PART WILL BE SPARED BY ANYTHING TOO SIGNIFICANT AS
UPPER TROUGH SLIPS THROUGH THE REGION EARLY TODAY.
MAIN UPPER ENERGY FOCUSED WELL SOUTH OF THE AREA TODAY...HOWEVER...
WILL HAVE PERIOD OF DECENT DIV Q AND PV ADVECTION FOR MAINLY
SOUTHEASTERN CWA THROUGH THE MID TO LATE MORNING HOURS. AREA OF
LIGHT RAINFALL WILL MOVE OUT OF NEBRASKA AND CONTINUE TO EXPAND
ACROSS SOUTHERN PORTIONS OF NORTHWEST IOWA IN PREDAWN HOURS.
HIGH RESOLUTION MODEL SOLUTIONS SUPPORT A HIGHER POP/LOWER QPF
SCENARIO AS BAND WORKS EASTWARD EARLY THIS MORNING...SO BUMPED POPS
UP TO A BRIEF PERIOD OF LIKELY IN FAR SOUTHERN/SOUTHEASTERN CWA...
MAINLY TIMED ALONG WITH MID LEVEL FRONTAL BOUNDARY WHICH DOES HAVE
ENOUGH NEUTRALITY TO STABILITY FIELDS TO SUPPORT CONTRACTING BAND
OF PRECIP THIS MORNING. THIS AREA SHOULD BE PRIMARILY OUT OF THE CWA
BY VERY LATE MORNING. MEANWHILE...LIGHT PRECIP CURRENTLY ACROSS
WESTERN SOUTH DAKOTA INDICATIVE OF THE LIFT FORCING WITH SECONDARY
ENERGY COMING OUT OF WYOMING. THIS PRECIP SHOULD APPROACH SOUTH
CENTRAL SOUTH DAKOTA LOCATIONS BY MID MORNING. FORTUNATELY...
TEMPERATURES SHOULD BE INCREASING BACK ABOVE FREEZING AS PRECIP
MOVES IN...AND ALSO THE OVERALL FORCING WILL START TO DIMINISH SOME
AS WORK INTO THE AFTERNOON HOURS...LIMITING COVERAGE AND INTENSITY
TO TRAILING PRECIP. THIS ROUND OF DYNAMICS HAS MORE FOCUS TOWARD THE
MISSOURI VALLEY...AND SHIFTED THE LOWER POP THREAT FOR THIS
PRECIPITATION SOUTHWARD FROM EARLIER FORECAST.
OTHER GOOD NEWS IS THAT THE OVERALL WIND GRADIENT SHOULD NOT BE
QUITE AS STRONG AS MODELS INDICATED THIS TIME YESTERDAY...AND THIS
SHOULD KEEP WINDS SPEEDS FROM REACHING ADVISORY CRITERIA DURING THE
LATER MORNING AND AFTERNOON. LIKELY TO GET A FEW 35-40 MPH GUSTS
THROUGH THE MISSOURI RIVER CORRIDOR...ESPECIALLY TOWARD LOWER BRULE
AREAS.
AS GO INTO TONIGHT...GRADIENT WILL START TO GRADUALLY DIMINISH...
SOMEWHAT QUICKER IN WESTERN AREAS DURING THE EVENING. SKIES WILL
ALSO TREND TOWARD MORE CLEARING SOUTH AND WEST...AS NORTHWEST FLOW
CONTINUES TO DUMP STRATUS THROUGH THE NORTHEAST HALF OF THE AREA
OVERNIGHT. QUITE A BIT OF SUBSIDENCE INDICATED WHICH SHOULD START
TO MAKE AREA MORE RAGGED BY VERY LATE NIGHT. TEMPS WILL COOL
ACCORDINGLY...WITH THE WEAKER GRADIENT IN THE WEST AND DRY AIR IN
RIDGE FOR SOME UPPER TEENS...WITH MAINLY LOWER TO MID 20S ELSEWHERE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 412 AM CST SUN NOV 17 2013
WE SEE A RETURN TO SOUTHERLY FLOW AND WARMING ALOFT ON
MONDAY...SETTING UP A MILD DAY. IN A SIMILAR TYPE PATTERN THIS PAST
WEEK THE WARMEST GUIDANCE WAS THE WAY TO GO...SO KEPT THAT TREND
GOING WITH HIGHS IN THE 40S AND 50S. THE UNSEASONABLE WARMTH WILL
CONTINUE INTO TUESDAY...WITH ANOTHER DAY OF READINGS IN THE 50S.
WILL LIKELY SEE INCREASING HIGH AND MID CLOUDS THROUGH THE DAY AS AN
UPPER WAVE MOVES ACROSS THE AREA. THESE CLOUDS MAY TEMPER THE
WARMING SOMEWHAT SO DID NOT WANT TO GO TOO HIGH...ALTHOUGH IF CLOUDS
END UP THINNER OR LESS WIDESPREAD...TEMPERATURES WOULD PROBABLY END
UP A FEW DEGREES WARMER THAN CURRENTLY FORECAST. TUESDAY NIGHT WILL
BE A RELATIVELY MILD ONE WITH LOWS IN THE 30S AND 40S...WITH CLOUD
COVER AND A SOUTHERLY BREEZE OUT AHEAD OF OUR NEXT COLD FRONT.
PRETTY GOOD AGREEMENT ON THE COLD FRONT COMING ACROSS WEDNESDAY
MORNING. COLD AIR ALOFT LAGS THE SURFACE FRONT A BIT...WHICH
COMBINED WITH INCREASED MIXING BEHIND THE FRONT...WILL LEAD TO
ANOTHER MILD DAY...ESPECIALLY ACROSS OUR EAST. THUS WENT AHEAD AND
RAISED HIGHS SOME OVER NORTHWEST IOWA AND PORTIONS OF SOUTHWEST
MINNESOTA. OVERALL EXPECTING 50S THERE...WITH 40S OVER THE NORTHWEST
HALF OF THE AREA. SEEMS LIKE WE WOULD SEE FALLING TEMPERATURES BY
AFTERNOON AS THE STRONG COLD AIR ADVECTION KICKS IN.
MODELS THEN BEGIN TO DIVERGE WEDNESDAY NIGHT INTO THE END OF THE
WEEK. A COMPLEX PATTERN WITH THE COLD AIRMASS ASSOCIATED WITH THE
NORTHERN STREAM WAVE INTERACTING WITH SOUTHERN STREAM ENERGY COMING
INTO CALIFORNIA FROM THE PACIFIC. A LARGE SPREAD IN THE OPERATIONAL
MODELS AND GFS ENSEMBLES CONFIRM THAT THIS IS A LOW PREDICTABILITY
TYPE OF PATTERN. THE ECMWF IS MOST AGGRESSIVE WITH THE NORTHERN
STREAM WAVE...PUSHING COLD AND DRY AIR INTO OUR REGION THURSDAY INTO
FRIDAY. WHILE THE GFS AND GEM ARE NOT QUITE AS AGGRESSIVE...AND RIDE
SOME OF THE SOUTHERN STREAM ENERGY OVER THE BAROCLINIC ZONE
RESULTING IN A PERIOD OF PRECIPITATION FOR US SOMETIME THURSDAY INTO
FRIDAY MORNING. GFS ENSEMBLES OFFER A WIDE ARRAY OF
SOLUTIONS...RANGING FROM A MORE COLD AND DRY ECMWF LIKE
SOLUTION...TO A MUCH FURTHER NORTH...MORE PHASED AND WARMER
SOLUTION. CANT SEE MUCH REASON TO FAVOR ONE IDEA OVER ANOTHER AT
THIS POINT...SO WILL JUST CONTINUE TO MONITOR TRENDS OVER THE COMING
DAYS....NOTING THE POTENTIAL FOR AT LEAST A LIGHT PRECIPITATION
EVENT IN THIS TIME FRAME. WOULD SEEM LIKE WE WOULD TEND TO BE DRY
ON SATURDAY WITH HIGH PRESSURE BUILDING IN AND ANOTHER POTENTIAL
ARCTIC FRONT DIVING SOUTH OUT OF CANADA. MODELS AGAIN JUMPING ALL
OVER THE PLACE WITH REGARDS TO WHETHER THIS COLD SHOT DIVES INTO
THE PLAINS...OR FURTHER EAST INTO THE GREAT LAKES REGION. SO
OVERALL...CONSENSUS TEMPERATURE GUIDANCE WAS PRETTY MUCH ACCEPTED
FROM THURSDAY INTO SATURDAY UNTIL MODEL AGREEMENT AND RUN TO RUN
CONSISTENCY INCREASES. TEMPERATURES SHOULD TEND TO RUN BELOW
NORMAL THIS PERIOD THOUGH...WITH CURRENT CONSENSUS GIVING HIGHS IN
THE 20S AND 30S AND LOWS IN THE TEENS AND 20S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 554 AM CST SUN NOV 17 2013
VERY COMPLEX AVIATION FORECAST THIS MORNING. STRATUS FIELD
OBSCURED FROM VIEW BY HIGHER LEVEL CLOUDS THIS MORNING...MAKING IT
DIFFICULT TO DIAGNOSE COVERAGE OF LOWER CLOUDS/FOG. OBSERVATIONS
INDICATE THERE IS SOME DENSE FOG ALONG THE WESTERN LEADING EDGE OF
AREA...MAINLY THROUGH THE JAMES VALLEY...INCLUDING THE KHON TAF.
THESE CONDITIONS SHOULD NOT LAST LONG...AND HAVE REFLECTED A
SOMEWHAT MORE OPTIMISTIC START WITH 12Z TAF. HRRR HAS PROVIDED
SOME ADEQUATE GUIDANCE AS TO SPREAD OF LOWER CEILINGS...AND
INDICATED THAT MUCH OF THE LIFR CEILINGS SHOULD START TO DIMINISH
BY 16Z TO 17Z. QUESTIONS REMAIN IF ANY WILL BE ABLE TO PUSH SOUTH
INTO KSUX AREA BEFORE MORE MIXY ENVIRONMENT SETS UP AND STRONGER
SUBSIDENCE ERODES ADVANCING CLOUDS. WINDS WILL GUST 25 TO 30 KNOTS
THROUGH THE AFTERNOON HOURS...BEFORE DIMINISHING THIS EVENING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...CHENARD
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
205 PM CST SUN NOV 17 2013
.DISCUSSION...
IN THE SHORT TERM...CLOUDY SKIES HANGING ON TOUGH ACROSS THE EAST
AND SOUTH WITH THE LOW LEVEL MOISTURE AXIS. TO THE NORTH AND WEST
MIDLEVEL DRY HAS SURGED AHEAD OF THE FRONTAL BOUNDARY AND HAS
PROVIDED MOSTLY CLEAR SKIES AND GOOD MIXING IN THE BOUNDARY LAYER
BUT LIKELY CAPPED JUST ABOVE. AS OF 20Z THE COLD FRONT/DRYLINE IS
NOW CROSSING LAWRENCE AND RANDOLPH COUNTIES WITH CONVECTION REALLY
STRUGGLING TO GET GOING DESPITE THE CLEARING AND DEWPOINTS NEAR
70F. WITH THIS SAID...THE NAM...GFS AND HRRR MODELS SHOW THE
FRONT BECOMING SOMEWHAT MORE ACTIVE ACROSS NORTHWEST TENNESSEE
BETWEEN 21-00Z. THIS STILL SEEMS VERY CONDITIONAL AND ISOLATED AS
MAX TEMPERATURES WILL START TO FALL. WILL BE TRIMMING BACK THE
CURRENT TORNADO WATCH BY 4 PM FOR THE COUNTIES WEST OF THE RIVER.
FURTHER SOUTH...FEEL RAIN SHOWERS WILL BE MORE LIKELY ESPECIALLY
THIS EVENING AS THE TAIL OF THE FRONT PASSES THROUGH NORTHEAST
MISSISSIPPI. THE SOUTHWEST DELTA COUNTIES WILL HAVE THE LOWEST
RAIN CHANCES FOR THE REMAINDER OF THE DAY. SKIES WILL CLEAR OUT
ACROSS THE SOUTH DURING THE NIGHT WITH SOME PATCHY FOG POSSIBLE.
MONDAY THROUGH WEDNESDAY...SURFACE HIGH PRESSURE WILL KEEP THE
MIDSOUTH DRY WITH NEAR SEASONAL TEMPERATURES. WINDS WILL VEER FROM
NORTH ON MONDAY TO SOUTHEASTERLY ON WEDNESDAY. LOWS TUESDAY AND
WEDNESDAY MORNING WILL BE NEAR FREEZING OVER THE NORTH AND EAST.
WEDNESDAY NIGHT THROUGH SUNDAY...GFS AND ECMWF BECOMING MORE IN
LINE DURING THIS PERIOD THAT WAA AND ISENTROPIC LIFT WILL GENERATE
LIGHT RAIN SHOWER ACTIVITY ACROSS THE MIDWEST FIRST...AND THEN
EXTEND IT SOUTHWARD ON THURSDAY. THIS IS IN RESPONSE TO A
DESCENDING 1040MB SURFACE HIGH IN THE NORTHERN PLAINS...AS IT
GENERATES A NEW COLD FRONT OVER THE MIDWEST. THIS BOUNDARY IS
FORECASTED TO SLOWLY PUSH SOUTH THROUGH OUR AREA THURSDAY NIGHT
THROUGH FRIDAY AND INTO EARLY SATURDAY. THUS THE END OF THE WORK
WEEK LOOKS TO BE COOL AND WET. THOUGH WITH THE LACK OF ANY
SIGNIFICANT UPPER LEVEL SUPPORT THUNDERSTORMS WILL BE MINIMAL. AS
THE FRONT MOVES TOWARDS THE GULF COAST ON SATURDAY...NORTH WINDS
WILL KEEP THE WEEKEND HIGHS TEN TO FIFTEEN DEGREES BELOW
NORMAL...WITH MAINLY 40S TO LOW 50S.
JAB
&&
.AVIATION...
A MID LEVEL DRY SLOT WILL CONTINUE TO ROTATE NORTHEASTWARD INTO
NORTHERN PORTIONS OF THE MID SOUTH HELPING TO MIX OUT LOW LEVEL
STRATUS. THIS SHOULD BE COMMON WITHIN THE NEXT FEW HOURS AT
KJBR...KMKL...AND KMEM WITH CIGS EVENTUALLY GOING VFR. FURTHER
SOUTH...LOW LEVEL MOISTURE AXIS WILL LIKELY MAINTAIN A LONGER TIME
PERIOD WITH IFR TO MVFR CIGS PERSISTING THROUGH MUCH OF THE
AFTERNOON. SHOWER AND THUNDERSTORMS POTENTIAL REMAINS MUCH MORE
CONDITIONAL ACROSS OUR REGION THIS AFTERNOON AND THIS EVENING.
BEST POTENTIAL WILL REMAIN ACROSS OUR NORTHERN TIER COUNTIES WITH
THE BEST POTENTIAL AT KMKL WHERE A TEMPO HAS BEEN MAINTAINED FOR
LATER THIS AFTERNOON. THIS WILL BE MONITORED THROUGH THE DAY AS
TEMPO COVERAGE MAY STILL BE TOO HIGH. FOR NOW...HAVE KEPT A
VICINITY THUNDER MENTION AT KMEM AND KJBR. AGAIN MAY NEED TO PULL
THIS WITHIN THE NEXT FEW HOURS AS BEST LIFT REMAINS NORTH. STRONG
AND GUSTY SOUTHWEST WINDS WILL BE LIKELY AT ALL TERMINALS THROUGH
THE EARLY EVENING HOURS.
THE FRONT WILL COME ACROSS THE TERMINALS FROM WEST TO EAST THIS
EVENING WITH SKIES CLEARING AND WINDS BECOMING NORTHWESTERLY AND
WEAKENING AS HIGH PRESSURE BUILDS IN. LATER TONIGHT CLEAR SKIES
AND DIMINISHED WINDS ARE EXPECTED AND WILL CONTINUE THROUGH MID
DAY MONDAY.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 49 63 41 59 / 20 0 0 0
MKL 43 62 35 57 / 20 0 0 0
JBR 43 61 36 55 / 10 0 0 0
TUP 48 66 38 60 / 40 0 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ALCORN-BENTON MS-
CALHOUN-COAHOMA-DESOTO-LAFAYETTE-MARSHALL-PANOLA-PONTOTOC-
QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TUNICA-UNION-YALOBUSHA.
TN...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CARROLL-CHESTER-
CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-
HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-
OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1216 PM CST SUN NOV 17 2013
.MESOSCALE UPDATE...
REGIONAL RADAR IMAGERY IS SHOWING AN INTENSE LINE OF
SEVERE/TORNADIC THUNDERSTORMS EXTENDING SOUTHWARD FROM NORTHERN IL
INTO SOUTHEAST MO. THIS LINE IS DEVELOPING JUST AHEAD OF A STRONG
COLD FRONT...WHICH ALSO HAS A THINNER LINE OF STORMS ALONG
IT...FURTHER WEST TOWARDS THE IA/IL BORDER. THE INITIAL LINE OF
STORMS COULD CONTINUE TO FILL IN SOUTHWARD. A RUC SOUNDING FROM
THE BOOTHEEL OF MO SHOWS PLENTY OF CAPE (WELL OVER 1000 J/KG) OVER
THE NEXT FEW HOURS. ONLY CONCERN FOR STORMS NOT CONTINUING TO
BUILD SOUTHWARD ALONG THE PRE-FRONTAL LINE WOULD BE A LITTLE
WARMING FORECAST IN THE NAM/GFS MODELS AROUND 800MB WHICH COULD
CAP OUR REGION AHEAD OF THE FRONT. GOOD LOW-LEVEL MOISTURE
CONVERGENCE NEAR THE TN/MO/AR BORDER THOUGH COULD OVERCOME THAT.
WILL HAVE TO MONITOR OVER THE NEXT COUPLE OF HOURS...BUT THAT WAS
THE REASON FOR THE TOR WATCH BEING ISSUED TO OUR WEST.
IF STORMS DO IN FACT CONTINUE TO BUILD SOUTH...THE LINE SHOULD BE
THINNER AND LESS POTENT THAN THE INTENSE STORMS ACROSS THE LOWER
GREAT LAKES REGION AT THE MOMENT (AS EVIDENCED BY ACTIVITY OVER NE
AR FORMING NOW). YET THESE STORMS COULD STILL POSE THE DAMAGING
WIND/ISOLATED TORNADO THREAT HERE MOST LIKELY AFTER 3PM OVER OUR
FAR WESTERN COUNTIES.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR TNZ009>011-028>034-
062>066-075-077>080.
WIND ADVISORY UNTIL 10 PM CST THIS EVENING FOR TNZ005>008-
022>027-056>061-093>095.
&&
$$
AL
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1050 AM CST SUN NOV 17 2013
.UPDATE...
UPDATED FOR TORNADO WATCH.
&&
.DISCUSSION...
TORNADO WATCH THROUGH 7 PM LST NORTH OF A HARRISBURG ARKANSAS TO
HUNTINGDON TENNESSEE LINE. CURRENT DRY LINE ACROSS NORTH CENTRAL
ARKANSAS AND SOUTH CENTRAL MISSOURI WILL LIKELY BECOME MORE
ATICVE OVER THE NEXT FEW HOURS AS IT PUSHES TOWARDS THE MS RIVER.
A FEW OF THESE STORMS MAY BECOME SEVERE WITH DAMAGING WINDS AND A
POSSIBLE BRIEF TORNADO. HAVE ADJUSTED THE HWO ACCORDINGLY.
JAB
&&
.PREV DISCUSSION... /ISSUED 944 AM CST SUN NOV 17 2013/
UPDATE...
UPDATED TO REDUCE MORNING AND AFTERNOON RAIN CHANCES AND TO ADJUST
SEVERE WEATHER WORDING.
DISCUSSION...
FIRST...CONVECTION WITH THE LOW LEVEL INSTABILITY AXIS MOVING
FASTER EAST THAN PREVIOUSLY FORECASTED...SO HAVE ADJUSTED RAIN
CHANCES ACCORDINGLY FOR THE REMAINDER OF THE MORNING.
SECOND...AFTER ANALYSIS OF THE HRRR MODEL...CURRENT SIGNIFICANT
MIXING IN THE OBSERVATIONS AHEAD OF THE FRONT IN NORTHWEST
ARKANSAS...AND STRONG CAP DEVELOPING AHEAD OF THE FRONT OFF OF
12Z SGF SOUNDING...IT APPEARS THAT THE SEVERE THREAT WILL REMAIN
ACROSS THE NORTHERN AND EASTERN COUNTIES FOR THIS AFTERNOON WHERE
FRONTAL FORCING WILL BE STRONGEST. HELICITY VALUES NEAR 200
M^2/S^2 SUGGESTS WEAK TORNADOES WILL STILL BE POSSIBLE...THOUGH
DAMAGING WIND GUSTS IS STILL THE PRIMARY SEVERE THREAT. HAVE
ADJUSTED THE HWO ACCORDINGLY.
THIRD...MADE SOME ADJUSTMENTS TO AFTERNOON CLOUD COVER AS MORE BREAKS
IN THE LOW LEVEL MOISTURE IS ANTICIPATED...AIDING THE SOUTH TO
SOUTHWEST WINDS TO REACH THE WIND ADVISORY CRITERIA EAST OF THE MS RIVER.
JAB
PREV DISCUSSION... /ISSUED 523 AM CST SUN NOV 17 2013/
DISCUSSION... /ISSUED 458 AM CST SUN NOV 17 2013/
EARLY MORNING GOES WATER IMAGERY SHOWED A DEEP UPPER LEVEL TROF
OVER THE CENTRAL AND NORTHERN PLAINS. THIS FEATURE WAS LIFTING
EAST AND BECOMING NEGATIVELY TILTED. A 160KT 200MB JET EXTENDED
FROM NORTH TX ACROSS THE OZARK PLATEAU...WITH INCREASINGLY
DIFFLUENT FLOW EVIDENT DOWNSTREAM OF THE JET CORE. CLOSER TO
HOME... THUNDERSTORMS HAD FORMED ON THE SOUTHERN FLANK OF THE JET
CORE OVER NORTHERN AR...INTO WEST TN. THIS CONVECTION WAS ROOTED
IN AN ELEVATED LAYER...THUS FAR UNABLE TO TAP INTO THE GREATER
HELICITY EMBEDDED IN A WEAK NOCTURNAL INVERSION BELOW 925MB.
EXPECT THE SHOWERS AND THUNDERSTORMS TO SHIFT EASTWARD THROUGH THE
DAY PERHAPS LEAVING AREAS WEST OF THE RIVER FREE OF RAIN LATER THIS
MORNING.
LATE MORNING AND EARLY AFTERNOON SEVERE CHANCES WILL LIKELY DEPEND
ON STORMS BECOMING ROOTED IN THE BOUNDARY LAYER... TAPPING BETTER
DIRECTIONAL SHEAR FOR MORE PERSISTENT AND ORGANIZED STORM STRUCTURES.
NAM BUFR SOUNDINGS SUGGESTS THIS IS A DISTINCT POSSIBILITY...PARTICULARLY
IN THE 18Z TO 21Z TIME FRAME. STORMS WILL HAVE BETTER CHANCES OF
BECOMING SURFACED BASED WITH THE ARRIVAL OF A SURFACE COLD FRONT
INTO EASTERN AR AROUND 21Z/3PM. STORMS MAY REFORM AS FAR WEST AS
JONESBORO...FORMING A LINE THAT WILL PROGRESS SOUTHEAST INTO THE
NORTHEAST MS TOWARD 03Z/9 PM. MAIN SEVERE WEATHER THREAT ACROSS
THE MIDSOUTH WILL DAMAGING STRAIGHT LINE WINDS. 06Z NAM PROGGED
700MB WEST/SOUTHWEST WINDS OF 60 TO 75 KTS NORTH OF I40 THIS
AFTERNOON...PERHAPS LEADING TO SOME BOWING LINE SEGMENTS. THERE
WILL BE SUFFICIENT HELICITY AND CAPE FOR SECONDARY TORNADO
THREAT DURING THE MID TO LATE AFTERNOON.
THE NAM PROGGED 03Z/9PM SURFACE CAPE NEAR 1000 J/KG AND 3KM
HELICITY NEAR 300 M2/S2 AT TUPELO. STORMS ALONG THE ADVANCING COLD
FRONT WILL HAVE A SHOT AT BECOMING ROOTED IN THE BOUNDARY LAYER.
OTHERWISE...HIGHER CINH AND LOWER ELEVATED CAPE SHOULD PREVAIL
OVER NORTH MS AS THE NOCTURNAL INVERSION FORMS.
TRANQUIL WEATHER WILL PREVAIL MONDAY THROUGH WEDNESDAY...COURTESY
OF PACIFIC SURFACE HIGH PRESSURE AND ZONAL FLOW ALOFT. GFS AND
ECMWF HAVE COME INTO BETTER AGREEMENT WITH RESPECT TO THE SPLIT
UPPER LEVEL FLOW PATTERN LATE IN THE WEEK. BY THURSDAY...MIDLEVEL
PACIFIC SUBTROPICAL MOISTURE WILL ACCOMPANY MODEST LOW LEVEL WARM
ADVECTION TO SUPPORT A RETURN OF SCATTERED SHOWERS TO THE MIDSOUTH.
BY LATE FRIDAY... COLLAPSING HEIGHTS OVER THE GREAT LAKES AND UPPER
MIDWEST WILL DRIVE A SURFACE COLD FRONT THE MIDSOUTH LATE FRIDAY.
COOLER AND MUCH DRIER MODIFIED ARCTIC AIR WILL SPREAD IN SATURDAY...
WITH MIDLEVEL CLOUDS AND MOISTURE LIKEWISE PUSHING OFF TO THE
SOUTH...INTO THE NORTHERN GULF OF MEXICO. NEXT WEEKEND/S WEATHER
SHOULD BE MORE TYPICAL OF LATE NOVEMBER.
PWB
&&
.AVIATION...
12Z TAF SET
IFR CIGS STILL HAVE YET TO MATERIALIZE EXCEPT AT KTUP. AREA OF
SHRAS WITH EMBEDDED TSRAS CONTINUES TO DEVELOP AND PUSH EAST
ACROSS THE CWA. CAN/T RULE OUT CIGS LOWERING TO IFR UNDERNEATH THE
HEAVIER SHRAS/TSRAS...OTHERWISE EXPECT MVFR CONDITIONS TO PREVAIL
THROUGH MUCH OF THE DAY AGAIN WITH THE POSSIBLE EXCEPTION OF KTUP.
WOULD NOT BE SURPRISED TO SEE CONDITIONS RETURN TO VFR AT
LOCATIONS SUCH AS KMEM AND KJBR THIS AFTERNOON. REDEVELOPMENT OF
TSRAS IS EXPECTED ALONG THE FRONT THIS AFTERNOON INTO THIS
EVENING. BEST CHANCES WILL OCCUR AT KMKL AND KTUP BETWEEN 23Z-05Z.
SKIES WILL QUICKLY CLEAR BEHIND THE FRONT. STRONG S TO SW WINDS
EXPECTED TODAY WITH SUSTAIN SPEEDS OF 10-17 KTS WITH GUSTS BETWEEN
15-28 KTS. WINDS WILL TURN AROUND TO THE NW AND EVENTUALLY N
BEHIND THE FRONT. SPEEDS WILL DIMINISH TO BETWEEN 5-10 KTS AS WELL
DURING THE OVERNIGHT HOURS.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 78 46 62 40 / 100 20 0 0
MKL 76 41 61 34 / 100 30 0 0
JBR 79 42 60 35 / 60 10 0 0
TUP 76 46 65 37 / 100 40 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ALCORN-BENTON MS-
CALHOUN-COAHOMA-DESOTO-LAFAYETTE-MARSHALL-PANOLA-PONTOTOC-
QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TUNICA-UNION-YALOBUSHA.
TN...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CARROLL-CHESTER-
CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-
HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-
OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
944 AM CST SUN NOV 17 2013
.UPDATE...
UPDATED TO REDUCE MORNING AND AFTERNOON RAIN CHANCES AND TO ADJUST
SEVERE WEATHER WORDING.
&&
.DISCUSSION...
FIRST...CONVECTION WITH THE LOW LEVEL INSTABILITY AXIS MOVING
FASTER EAST THAN PREVIOUSLY FORECASTED...SO HAVE ADJUSTED RAIN
CHANCES ACCORDINGLY FOR THE REMAINDER OF THE MORNING.
SECOND...AFTER ANALYSIS OF THE HRRR MODEL...CURRENT SIGNIFICANT
MIXING IN THE OBSERVATIONS AHEAD OF THE FRONT IN NORTHWEST
ARKANSAS...AND STRONG CAP DEVELOPING AHEAD OF THE FRONT OFF OF
12Z SGF SOUNDING...IT APPEARS THAT THE SEVERE THREAT WILL REMAIN
ACROSS THE NORTHERN AND EASTERN COUNTIES FOR THIS AFTERNOON WHERE
FRONTAL FORCING WILL BE STRONGEST. HELICITY VALUES NEAR 200
M^2/S^2 SUGGESTS WEAK TORNADOES WILL STILL BE POSSIBLE...THOUGH
DAMAGING WIND GUSTS IS STILL THE PRIMARY SEVERE THREAT. HAVE
ADJUSTED THE HWO ACCORDINGLY.
THIRD...MADE SOME ADJUSTMENTS TO AFTERNOON CLOUD COVER AS MORE BREAKS
IN THE LOW LEVEL MOISTURE IS ANTICIPATED...AIDING THE SOUTH TO
SOUTHWEST WINDS TO REACH THE WIND ADVISORY CRITERIA EAST OF THE MS RIVER.
JAB
&&
.PREV DISCUSSION... /ISSUED 523 AM CST SUN NOV 17 2013/
DISCUSSION... /ISSUED 458 AM CST SUN NOV 17 2013/
EARLY MORNING GOES WATER IMAGERY SHOWED A DEEP UPPER LEVEL TROF
OVER THE CENTRAL AND NORTHERN PLAINS. THIS FEATURE WAS LIFTING
EAST AND BECOMING NEGATIVELY TILTED. A 160KT 200MB JET EXTENDED
FROM NORTH TX ACROSS THE OZARK PLATEAU...WITH INCREASINGLY
DIFFLUENT FLOW EVIDENT DOWNSTREAM OF THE JET CORE. CLOSER TO
HOME... THUNDERSTORMS HAD FORMED ON THE SOUTHERN FLANK OF THE JET
CORE OVER NORTHERN AR...INTO WEST TN. THIS CONVECTION WAS ROOTED
IN AN ELEVATED LAYER...THUS FAR UNABLE TO TAP INTO THE GREATER
HELICITY EMBEDDED IN A WEAK NOCTURNAL INVERSION BELOW 925MB.
EXPECT THE SHOWERS AND THUNDERSTORMS TO SHIFT EASTWARD THROUGH THE
DAY PERHAPS LEAVING AREAS WEST OF THE RIVER FREE OF RAIN LATER THIS
MORNING.
LATE MORNING AND EARLY AFTERNOON SEVERE CHANCES WILL LIKELY DEPEND
ON STORMS BECOMING ROOTED IN THE BOUNDARY LAYER... TAPPING BETTER
DIRECTIONAL SHEAR FOR MORE PERSISTENT AND ORGANIZED STORM STRUCTURES.
NAM BUFR SOUNDINGS SUGGESTS THIS IS A DISTINCT POSSIBILITY...PARTICULARLY
IN THE 18Z TO 21Z TIME FRAME. STORMS WILL HAVE BETTER CHANCES OF
BECOMING SURFACED BASED WITH THE ARRIVAL OF A SURFACE COLD FRONT
INTO EASTERN AR AROUND 21Z/3PM. STORMS MAY REFORM AS FAR WEST AS
JONESBORO...FORMING A LINE THAT WILL PROGRESS SOUTHEAST INTO THE
NORTHEAST MS TOWARD 03Z/9 PM. MAIN SEVERE WEATHER THREAT ACROSS
THE MIDSOUTH WILL DAMAGING STRAIGHT LINE WINDS. 06Z NAM PROGGED
700MB WEST/SOUTHWEST WINDS OF 60 TO 75 KTS NORTH OF I40 THIS
AFTERNOON...PERHAPS LEADING TO SOME BOWING LINE SEGMENTS. THERE
WILL BE SUFFICIENT HELICITY AND CAPE FOR SECONDARY TORNADO
THREAT DURING THE MID TO LATE AFTERNOON.
THE NAM PROGGED 03Z/9PM SURFACE CAPE NEAR 1000 J/KG AND 3KM
HELICITY NEAR 300 M2/S2 AT TUPELO. STORMS ALONG THE ADVANCING COLD
FRONT WILL HAVE A SHOT AT BECOMING ROOTED IN THE BOUNDARY LAYER.
OTHERWISE...HIGHER CINH AND LOWER ELEVATED CAPE SHOULD PREVAIL
OVER NORTH MS AS THE NOCTURNAL INVERSION FORMS.
TRANQUIL WEATHER WILL PREVAIL MONDAY THROUGH WEDNESDAY...COURTESY
OF PACIFIC SURFACE HIGH PRESSURE AND ZONAL FLOW ALOFT. GFS AND
ECMWF HAVE COME INTO BETTER AGREEMENT WITH RESPECT TO THE SPLIT
UPPER LEVEL FLOW PATTERN LATE IN THE WEEK. BY THURSDAY...MIDLEVEL
PACIFIC SUBTROPICAL MOISTURE WILL ACCOMPANY MODEST LOW LEVEL WARM
ADVECTION TO SUPPORT A RETURN OF SCATTERED SHOWERS TO THE MIDSOUTH.
BY LATE FRIDAY... COLLAPSING HEIGHTS OVER THE GREAT LAKES AND UPPER
MIDWEST WILL DRIVE A SURFACE COLD FRONT THE MIDSOUTH LATE FRIDAY.
COOLER AND MUCH DRIER MODIFIED ARCTIC AIR WILL SPREAD IN SATURDAY...
WITH MIDLEVEL CLOUDS AND MOISTURE LIKEWISE PUSHING OFF TO THE
SOUTH...INTO THE NORTHERN GULF OF MEXICO. NEXT WEEKEND/S WEATHER
SHOULD BE MORE TYPICAL OF LATE NOVEMBER.
PWB
&&
.AVIATION...
12Z TAF SET
IFR CIGS STILL HAVE YET TO MATERIALIZE EXCEPT AT KTUP. AREA OF
SHRAS WITH EMBEDDED TSRAS CONTINUES TO DEVELOP AND PUSH EAST
ACROSS THE CWA. CAN/T RULE OUT CIGS LOWERING TO IFR UNDERNEATH THE
HEAVIER SHRAS/TSRAS...OTHERWISE EXPECT MVFR CONDITIONS TO PREVAIL
THROUGH MUCH OF THE DAY AGAIN WITH THE POSSIBLE EXCEPTION OF KTUP.
WOULD NOT BE SURPRISED TO SEE CONDITIONS RETURN TO VFR AT
LOCATIONS SUCH AS KMEM AND KJBR THIS AFTERNOON. REDEVELOPMENT OF
TSRAS IS EXPECTED ALONG THE FRONT THIS AFTERNOON INTO THIS
EVENING. BEST CHANCES WILL OCCUR AT KMKL AND KTUP BETWEEN 23Z-05Z.
SKIES WILL QUICKLY CLEAR BEHIND THE FRONT. STRONG S TO SW WINDS
EXPECTED TODAY WITH SUSTAIN SPEEDS OF 10-17 KTS WITH GUSTS BETWEEN
15-28 KTS. WINDS WILL TURN AROUND TO THE NW AND EVENTUALLY N
BEHIND THE FRONT. SPEEDS WILL DIMINISH TO BETWEEN 5-10 KTS AS WELL
DURING THE OVERNIGHT HOURS.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 78 46 62 40 / 100 20 0 0
MKL 76 41 61 34 / 100 30 0 0
JBR 79 42 60 35 / 60 10 0 0
TUP 76 46 65 37 / 100 40 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR DUNKLIN-PEMISCOT.
MS...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR ALCORN-BENTON MS-
CALHOUN-COAHOMA-DESOTO-LAFAYETTE-MARSHALL-PANOLA-PONTOTOC-
QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TUNICA-UNION-YALOBUSHA.
TN...WIND ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR CARROLL-CHESTER-
CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-
HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-
OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
357 PM EST SUN NOV 17 2013
.SYNOPSIS...
LOW PRESSURE WAS OVER THE GREAT LAKES WITH A STRONG COLD FRONT
EXTENDING FROM THE LOW INTO THE SOUTHERN PLAINS. THIS FRONT WILL
RACE EAST TONIGHT AND WILL BE OFF THE COAST BY MONDAY AFTERNOON. COLD
HIGH PRESSURE SETTLES OVER THE GREAT LAKES TUESDAY AND WEDNESDAY
BRINGING DRIER WEATHER INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 345 PM EST SUNDAY...
RAPIDLY CHANGING WEATHER TONIGHT AND MONDAY. AREA OF LIGHT TO
MODERATE SHOWERS WAS MOVING INTO THE WESTERN COUNTY WARNING AREA
AS OF 300PM. LOCAL WRF...HRRR AND RAP MODELS HAVE THESE SHOWERS
MOVING EAST ACROSS THE FORECAST AREA BY MIDNIGHT.
INTENSE COLD FRONT EXTENDED FROM NORTHERN ILLINOIS INTO CENTRAL
ARKANSAS. THIS FRONT WILL MOVE QUICKLY EAST AND WILL REACH THE
WESTERN COUNTIES OF THE FORECAST AREA AROUND 11PM. AHEAD OF THE
FRONT THE LOW LEVEL JET INCREASES...WITH 850 MB WINDS IN THE 50 TO
60 KNOT RANGE. HAVE EXPANDED THE WIND ADVISORY INTO TAZEWELL
COUNTY FOR TONIGHT.
STILL A THREAT OF STRONG TO DAMAGING WINDS AFTER MIDNIGHT WITH THE
BAND OF SHOWERS AND POSSIBLY ISOLATED THUNDERSTORMS ALONG THE
FRONT. THE FRONT IS EXPECTED TO EXIT THE EASTERN COUNTY WARNING
AREA BETWEEN 4AM AND 7AM.
NOT MUCH DROP IN TEMPERATURES UNTIL THE FRONT GOES THROUGH THEN ON
MONDAY NOT MUCH RECOVERY OF TEMPERATURES WITH MODERATE COLD AIR
ADVECTION. STRONG ENOUGH PRESSURE RISES...IN THE +5 TO +10
MB/6HR RANGE TO ENHANCE THE WINDS FOR MUCH OF THE DAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 311 PM EST SUNDAY...
STILL A GRADIENT LEFT MONDAY NIGHT ALTHOUGH SURFACE HIGH PRESSURE IS
ON APPROACH. LEFTOVER WINDS COMBINED WITH SOME CLOUDS ACROSS SE WEST
VA WILL KEEP TEMPS A LITTLE WARMER THAN THEY WOULD BE IF THE CENTER
OF THE SURFACE HIGH WAS PARKED OVERHEAD. INTO TUESDAY
AFTERNOON...HIGH PRESSURE BEGINS A TRIP TOWARDS PENNSYLVANIA AND NEW
ENGLAND...EVENTUALLY IN THE QUINTESSENTIAL WEDGE POSITION FOR
WEDNESDAY. WITH DOWNSLOPING FLOW REMOVED...COLDER H85 VALUES AROUND
0C WILL COVER MOST OF THE CWA UNDER CLEAR SKIES TUESDAY. DEWPOINTS
MAY FALL INTO THE LOWER 20S AND UPPER TEENS SETTING THE STAGE FOR A
VERY COLD TUESDAY NIGHT...IF MID AND HIGH CLOUDS HOLD OFF FROM THE
SOUTH...AND DEVELOPING EASTERLY FLOW REMAINS WEAK. INCREASING
MID/HIGH CLOUDS WEDNESDAY...A VERY COLD START AND SUBTLE EASTERLY
BREEZES WITHIN THE WEDGE MAY KEEP MOST LOCATIONS BELOW 50F FOR
WEDNESDAY...WHICH IS BELOW THE MEX/ECMWF MOS NUMBERS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 340 PM EST SUNDAY...
A FEW CHANGES IN THE EXTENDED FORECAST BUT STILL LOOKS WET FRIDAY
NIGHT INTO SATURDAY EVENING. MODELS ARE ARGUING WHICH WEATHER
FEATURE WILL BRING RAIN TO THE AREA. THE 12Z GFS FAVORS A SHORT
COMING ACROSS THE TENN VALLEY AND OVER THE WEDGE THURSDAY NIGHT.
FRIDAY AND FRIDAY NIGHT...THE GFS HAS WAVES RIDING ALONG THE
FRONT..EVENTUALLY PUSHING THE COLD FRONT TO THE EAST COAST SATURDAY
MORNING. THE 12Z ECMWF HAS A COLD FRONT MOVING SLOWLY TO THE
EAST...FROM MISSISSIPPI VALLEY THURSDAY NIGHT...INTO THE OHIO VALLEY
FRIDAY AFTERNOON...THEN STALLS IT OVER THE MID ATLANTIC-SOUTHERN
APPALACHIAN MOUNTAINS SATURDAY MORNING. A SURFACE WAVE THEN DEVELOPS
ALONG THE FRONT...POSSIBLY OVER THE FORECAST AREA SATURDAY. THIS
WAVE WILL THEN TRACK NORTHEAST...PULLING THE FRONT ACROSS THE REGION
BY SATURDAY EVENING. SINCE THERE IS DISCONTINUITY BETWEEN MODELS AND
RUN-TO-RUN WITH EACH MODEL...WILL KEEP POPS IN A 20-40 PERCENT RANGE
FRIDAY AFTERNOON INTO SATURDAY AFTERNOON.
WITH EITHER MODEL AND/OR SCENARIO...THE GULF IS OPEN TO BRING THE
AREA MUCH NEEDED RAIN FRIDAY INTO SATURDAY. ALSO...MILD TO WARM
TEMPERATURES LIKELY FRIDAY...DEPENDING ON IF A LOCATION SEES RAIN.
ONCE THE FRONT MOVES TO THE COAST...85H TEMPERATURES DROP TO -10C.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
AS OF 1250 AM EST SUNDAY...
SIGNIFICANT CHANGES WILL BE OCCURRING DURING THE TAF PERIOD.
LIFR TO IFR STRATUS AND FOG EAST OF THE BLUE RIDGE WILL GRADUALLY
LIFT AS A SURFACE WEDGE ERODES AND WINDS BECOME SOUTH TO
SOUTHWEST. THE VISIBILITY AT KROA AND KDAN HAD ALREADY BECOME VFR.
KLYH MAY TAKE UNTIL 20/3PM TO IMPROVE.
A BAND OF SHOWERS FROM WEST VIRGINIA INTO CENTRAL TENNESSEE WILL
MOVE ACROSS THE REGION BETWEEN 21Z/4PM AND 06Z/1AM. EXPECT THIS
PRECIPITATION TO REACH KLWB AROUND 21Z/4PM WITH OCCASIONAL MVFR
VISIBILITIES AND VFR CEILINGS JUST ABOVE 3000 FEET. THESE SHOWERS
ARE NOT EXPECTED TO REACH KLYH AND KDAN UNTIL AFTER 00Z/7PM.
A STRONG COLD FRONT WILL BE CROSSING THE AREA BETWEEN 00Z AND 12Z.
MODELS WERE ALL SIMILAR WITH THE TIMING OF THE FRONT. LINE OF
SHOWERS ALONG THE BOUNDARY MAY PRODUCE WIND GUSTS AT KLWB AND KBLF
OF 40 TO 50 KNOTS BUT CONFIDENCE IS LOW THAT OTHER TAF SITES WILL
HAVE THE POTENTIAL FOR WINDS THAT STRONG SINCE LINE IS EXPECTED TO
WEAKEN AS IT MOVES EAST.
COLD AIR ADVECTION AND TIGHT PRESSURE GRADIENTS WILL RESULT IN
GUSTY WINDS BY MONDAY AFTERNOON. EXPECT WIND GUSTS OF 25 TO
35 KNOTS. THE SKY WILL CLEAR MONDAY MORNING AS A MUCH DRIER AIR
MASS ADVECTS INTO THE REGION.
DRY HIGH PRESSURE WILL SUPPORT VFR CONDITIONS THROUGH TUESDAY
AFTERNOON...BEFORE WEDGING AGAINST THE EASTERN FACE OF THE
APPALACHIANS. MAY SEE A RETURN OF STRATUS THURSDAY MORNING AS THE
NORTHEAST FLOW WORKS ATLANTIC MOISTURE TOWARD THE BLUE RIDGE.
&&
.FIRE WEATHER...
AS OF 450 AM EST SUNDAY...
REGION STAYS IN MOIST AIR MASS TONIGHT IN ADVANCE OF A STRONG
COLD FRONT. THE PROBABILITY OF A WETTING RAIN RISES SHARPLY BY
THIS EVENING. WINDS FROM THE SOUTH AND SOUTHWEST INCREASE LATER
OVERNIGHT....ESPECIALLY AT HIGHER ELEVATIONS AHEAD OF THE FRONT.
ONCE THE FRONT COMES THROUGH EARLY MONDAY MORNING...WIND WILL SHIFT
TO THE WEST AND NORTHWEST. GUSTY WINDS ARE EXPECTED MONDAY AND
MONDAY NIGHT. BY THE TIME RELATIVE HUMIDITIES DROP BACK DOWN TO
AROUND 30 PERCENT ON TUESDAY...WIND SPEEDS WILL BE DIMINISHING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 6 AM EST MONDAY FOR VAZ007-019-020-024-035.
NC...NONE.
WV...WIND ADVISORY UNTIL 6 AM EST MONDAY FOR WVZ042-043-045.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KM
LONG TERM...RCS
AVIATION...AMS/NF
FIRE WEATHER...AMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
408 AM EST TUE NOV 19 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD TODAY THEN TO NEW ENGLAND ON
WEDNESDAY. LOW PRESSURE WILL TRACK OUT OF THE PLAINS LATE FRIDAY
INTO SATURDAY AND PULL A STRONG COLD FRONT ACROSS THE AREA. HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE TOWARDS THE OHIO VALLEY
ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST TODAY WHILE A
TROUGH LINGERS OVER QUEBEC. WE HAD LITTLE IN THE WAY OF LAKE EFFECT
SNOW OVERNIGHT WITH RIDGING OVER ALL BUT ABOUT THE EASTERN THIRD OF
LAKE ERIE. SOME LIGHT SNOW SHOWERS THAT WERE FOCUSED TOWARDS NEW
YORK MAY SHIFT WESTWARD INTO MAINLY NW PA AS WINDS THROUGH 850MB
BECOME MORE NORTHERLY THIS MORNING. AFTER THAT TIME THE MOISTURE
DEPTH DECREASES WITH STRENGTHENING SUBSIDENCE AND SHOWERS WILL COME
TO AN END. NO ACCUMULATION EXPECTED.
MOST MODELS NOT HANDLING THE CLOUD FIELD VERY WELL OVER THE REGION
WITH SKIES CLEARING BY LATE MORNING. INVERSION HEIGHTS LOWER TODAY
AS THE HIGH BUILDS OVERHEAD AND THE RUC SEEMS TO BE DOING THE BEST
WITH WITH HIGH 925MB MOISTURE THROUGH THE DAY. WILL FAVOR A MORE
PESSIMISTIC CLOUD FORECAST WITH CLOUDS EVENTUALLY SCATTERING OUT
THIS EVENING. HIGHS WILL ONLY RECOVER A FEW DEGREES WITH COOL
NORTHERLY FLOW WITH HIGHS IN THE UPPER 30S/LOW 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
QUIET WEATHER WILL CONTINUE ON WEDNESDAY AS WE REMAIN UNDER THE
INFLUENCE OF HIGH PRESSURE EXTENDING FROM NEW ENGLAND. THERE WILL BE
SOME INCREASE IN CIRRUS AS THE UPPER LEVEL RIDGE SHIFTS EAST OF THE
AREA. WITH FLOW SHIFTING AROUND TO THE SOUTHEAST AND PERIODS OF
SUN...TEMPERATURES WILL RECOVER TO THE MID AND UPPER 40S.
UPPER LEVEL JET ENERGY APPROACHING CALIFORNIA WILL CARVE OUT A BROAD
TROUGH OVER THE WESTERN UNITED STATES WHILE A MORE COMPACT TROUGH
NEAR BRITISH COLUMBIA MOVES THROUGH THE NORTHERN STREAM. MOISTURE
WILL INCREASE OVER THE REGION FROM WEDNESDAY NIGHT INTO THURSDAY AS
SHORTWAVE ENERGY MOVES OUT OF THE TROUGH TO OUR WEST AND
SOUTHWESTERLY FLOW INCREASES. IT WILL TAKE A WHILE TO MOISTEN THE
ATMOSPHERE AND WILL ONLY CARRY LOW POPS...MAINLY IN THE WEST THROUGH
THURSDAY. CHANCES OF PRECIPITATION THEN INCREASE FROM THURSDAY NIGHT
THROUGH FRIDAY NIGHT AS LOW PRESSURE MOVES NORTHEAST ACROSS THE AREA
IN ADVANCE OF THE STRENGTHENING TROUGH OVER CANADA. THE GFS IS
CONSIDERABLY STRONGER WITH THE SURFACE LOW AND LEAD PIECE OF UPPER
LEVEL ENERGY AND AN OUTLIER FROM SEVERAL OF THE OTHER LONG RANGE
MODELS AND OTHER GFS ENSEMBLE MEMBERS. WILL LEAN THE BETTER
CONSENSUS FOR NOW WITH A WEAKER SURFACE WAVE WHICH IS A LITTLE
SLOWER AND LESS ROBUST WITH PRECIPITATION.
PRECIPITAITON WILL LARGELY BE A RESULT OF ISENTROPIC ASCENT ON
THURSDAY NIGHT AND FRIDAY AND WILL BE ALL RAIN AS 850MB TEMPS WARM
TO 6C. FRONTOGENESIS STRENGTHENS ACROSS NW OHIO BY FRIDAY NIGHT AND
WILL INCLUDE A RAIN/SNOW MIX AS THERMAL PROFILES START TO COOL.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
WINTER IS GOING TO GET GOING OVER THE WEEKEND. THE MODELS CONTINUE
TO COME INTO BETTER AGREEMENT. BY THE START OF THE PERIOD VERY
STRONG COLD AIR ADVECTION WILL BE OCCURRING. PRECIP APPEARS LIKELY
ON SATURDAY WITH A TRANSITION FROM RAIN TO SNOW OCCURRING AS THE DAY
PROGRESSES. THE NEW GUIDANCE STILL DROPS 850 MB TEMPS TO NEG 16 BY
12Z SUNDAY AND IT APPEARS THAT THE SNOWBELT COULD SEE A GOOD LAKE
EFFECT EVENT. EVEN WESTERN AREAS COULD SEE SOME SNOW SHOWERS FROM
LAKE MICHIGAN. HAVE ONLY MADE MINOR ADJUSTMENTS TO THE PRECIP
FORECAST AS THE PREVIOUS PACKAGE ALREADY HAD LIKELY POPS IN.
SURFACE RIDGING WILL BEGIN TO OCCUR SUNDAY NIGHT INTO MONDAY AND
THIS SHOULD END THE SNOW THREAT. IF CURRENT TRENDS HOLD...SUSPECT
THAT SOME SORT OF WINTER WEATHER HEADLINES WILL BE NEEDED FOR
SUNDAY. HIGHS SUNDAY WILL BE ALMOST 20 DEGREES BELOW NORMAL WITH
READINGS STRUGGLING TO GET ABOVE 30 DEGREES. IT WILL ONLY BE A TAD
WARMER ON MONDAY.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
DEEP LOW PRESSURE IN WESTERN QUEBEC WILL CONTINUE NORTHEAST
OVERNIGHT AS HIGH PRESSURE BUILDS IN FROM THE WEST. LOW LEVEL WRAP
AROUND MOISTURE IS CURRENTLY ACROSS NRN OHIO AND NWRN PA TRAPPED
UNDER AN INVERSION. MOST CIGS VFR HOWEVER THERE ARE PATCHES OF
MVFR MIXED IN. DO EXPECT PERIODS OF MVFR TO CONTINUE ESPECIALLY
KERI WHERE COLD ADVECTION WILL INCREASINGLY TAP LAKE MOISTURE.
ALSO A DECENT CHANCE OF AN MVFR CIG AT KMFD IN UPSLOPE FLOW AND
ALSO KTOL...ADVECTING IN FROM SRN LWR MI. OTHERWISE EXPECT A LOW
VFR CIGS TO CONTINUE ACROSS THE REGION THROUGH THE NIGHT. DID KEEP
MVFR CONDITIONS AT KERI MOST OF THE NIGHT WITH A FEW LIGHT RAIN
AND SNOW SHOWERS POSSIBLE WITH THE INCREASING LAKE INFLUENCE.
TREND TO VFR FOR THE AREA TUESDAY WITH BUILDING HIGH PRESSURE
HOWEVER THERE IS A POTENTIAL THAT THE STRATUS WILL HANG ON
INTO/THRU THE MORNING HOURS...REMAINING TRAPPED UNDER THE
INVERSION.
OUTLOOK...NON VFR POSSIBLE THURSDAY.
&&
.MARINE...
STILL SEEING SUSTAINED WINDS IN THE 20 TO 25 KNOT RANGE SO WILL KEEP
THE SMALL CRAFT HEADLINES GOING AS IS. SPEEDS SHOULD DIMINISH
QUICKLY THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. THE FLOW WILL
BECOME SE TONIGHT AS THE SURFACE RIDGE MOVES EAST OF THE LAKE. SE
TO S FLOW IS THEN EXPECTED INTO THE END OF THE WEEK. LOW PRESSURE
WILL EVENTUALLY CROSS THE REGION SOMETIME FRIDAY PULLING ANOTHER
ARCTIC COLD FRONT ACROSS THE LAKE. STRONG WESTERLY WINDS WILL
DEVELOP BEHIND THE FRONT AND SPEEDS COULD GET CLOSE TO GALE FORCE IN
THE STRONG COLD AIR ADVECTION. THE STRONG FLOW WILL BECOME
NORTHWEST ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LEZ148-
149.
SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR
LEZ144>147.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...TK
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
348 AM CST TUE NOV 19 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
AT 3 AM...A 1027 MB HIGH WAS CENTERED OVER NORTHERN ILLINOIS.
THE 19.00Z MODELS ARE IN GOOD AGREEMENT THAT THE HIGH WILL MOVE
NORTHEAST INTO LOWER MICHIGAN TODAY AND INTO NORTHERN NEW YORK
STATE BY WEDNESDAY MORNING. AS THIS OCCURS...SOUTH WINDS WILL
DEVELOP AND INCREASE INTO THE 10 TO 20 MPH RANGE THIS
MORNING...AND INTO THE 15 TO 25 MPH RANGE THIS AFTERNOON AND
CONTINUE INTO TONIGHT. AS USUAL...THE NAM IS MUCH HIGHER THAN THE
RUC AND GFS WITH ITS WIND GUSTS THIS AFTERNOON. THE NAM HAS WIND
GUSTS IN THE 30 TO 40 MPH RANGE. MEANWHILE THE RAP AND GFS HAVE
THEIR WIND GUSTS AROUND 30 MPH. SINCE THE NAM USUALLY IS A BIT TOO
HIGH...TRENDED THE WIND GUSTS TOWARD THE GFS AND RAP. BUFKIT
SOUNDINGS SHOW THAT THE MOISTURE WILL BE GRADUALLY INCREASING
ABOVE 500 MB TODAY. AS A RESULT WENT WITH INCREASING HIGH CLOUDS
THROUGHOUT THE DAY. THESE CLOUDS SHOULD ALLOW ENOUGH SUNSHINE FOR
TEMPERATURES TO APPROACH 50 DEGREES SOUTH OF INTERSTATE 94 AND
INTO THE MID AND UPPER 40S NORTH OF THIS INTERSTATE.
FROM LATE TONIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO SHOW
THAT THE 925 AND 850 MB MOISTURE TRANSPORT WILL INCREASE AHEAD OF
A SHORT WAVE TROUGH MOVING EAST OF THE PLAINS. THE BEST
SATURATION OCCURS ACROSS SOUTHWEST AND CENTRAL WISCONSIN ON
WEDNESDAY. AS A RESULT...WENT WITH THE HIGHEST RAIN CHANCES /40 TO
50 PERCENT/ FOR THIS AREA. RAINFALL AMOUNTS WILL BE LESS THAN A
TENTH OF AND INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
ON WEDNESDAY NIGHT...SUBSIDENCE QUICKLY DEVELOPS IN THE WAKE OF
THE TROUGH. AS THIS OCCURS...THE PRECIPITATION CHANCES QUICKLY
DECLINE DURING THE EVENING.
ON THURSDAY NIGHT...THE OPERATIONAL RUNS OF THE GFS...
ECMWF...AND NAM ARE SHOWING THAT A SOUTHERN AND NORTHERN STREAM
SYSTEM WILL PHASE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE
AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A 100 KNOT POLAR
JET AND THE LEFT EXIT REGION OF A 100 KNOT SUBTROPICAL JET. THESE
COUPLED JETS DRAMATICALLY INCREASE THE LIFT ACROSS THE AREA. DUE
TO THIS...THE MODELS ARE GENERATING MUCH MORE PRECIPITATION ACROSS
THE AREA THAN WHAT SHOWED UP IN PREVIOUS MODEL RUNS. DUE TO
THIS...THE PRECIPITATION CHANCES WERE RAISED UP TO 60 PERCENT.
HOWEVER THESE PRECIPITATION CHANCES ARE HIGHLY DEPENDENT UPON
WHETHER THIS JET COUPLING DOES INDEED OCCURS. 6 OF 12 GFS ENSEMBLE
MEMBERS SHOW THIS OCCURRING. MEANWHILE THE OTHER 6 SHOW THAT THESE
TWO SHORT WAVE TROUGHS WILL NOT PHASE AND THE AREA COULD
POTENTIALLY END UP BEING DRY. THIS IS 3 MORE MEMBERS THAN WHAT
SHOWED UP IN THE 18.18Z GFS ENSEMBLE. AS THESE WAVES MOVES
EAST...COLDER AIR WILL MOVE INTO THE REGION AS THE NIGHT
PROGRESSES AND THE PRECIPITATION WILL CHANGE OVER TO SLEET AND
SNOW. SNOW AMOUNTS COULD POTENTIALLY BE UP TO AN INCH NORTH OF AN
AUSTIN MINNESOTA TO NEILLSVILLE WISCONSIN LINE.
ON FRIDAY AND FRIDAY EVENING...COLDER AIR WILL SINK SOUTHWARD
ACROSS THE AREA. THIS WILL RESULT IN 950 TO 900 LAPSE RATES AROUND
OF 8 TO 9 C/KM. AS A RESULT...CONTINUED LIGHT SNOW CHANCES
THROUGHOUT MUCH OF THIS TIME PERIOD. ADDITIONAL SNOWFALL AMOUNTS
WILL BE LESS THAN A HALF INCH.
ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST REMAINS VERY
TRICKY. THIS IS DUE TO DIFFERING TIMES ON WHEN THE COLDEST AIR
WILL MOVE SOUTHWARD INTO THE FORECAST AREA. BOTH THE GFS AND GEM
HAS THIS AIR MASS ARRIVING MUCH SOONER...SO THEY HAS HIGH
TEMPERATURES REMAINING IN THE TEENS. MEANWHILE THE ECWMF IS A BIT
LATER AND THE HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID 20S.
SINCE THERE WERE SOME DRAMATIC DIFFERENCES...JUST STAYED WITH THE
ALL BLEND MAXIMUM TEMPERATURES.
SATURDAY NIGHT...LOOKS VERY COLD ACROSS THE AREA WITH 925 MB
TEMPERATURES OF -14 TO -16C AND WINDS LIGHTENING THROUGH THE
NIGHT. LOW TEMPERATURES ON SUNDAY MORNING WILL LIKELY BE IN THE
SINGLE DIGITS ACROSS THE AREA. IF WE END UP GETTING MORE SNOW
THAN EXPECTED ON THURSDAY NIGHT...THESE TEMPERATURES MAY BE EVEN
COLDER.
LIKE SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS VERY TRICKY
BECAUSE THE GFS HAD WARM AIR ADVECTION KICKING A BIT FASTER THAN
THE ECMWF. AS A RESULT...THE GFS IS WARMER THAN THE ECMWF. SINCE
IT IS UNCERTAIN ON WHICH MODEL WILL VERIFY THE BEST...JUST STAYED
WITH THE ALL BLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1125 PM CST MON NOV 18 2013
THE MAIN CONCERN WILL BE INCREASING WINDS TUE AND LLWS TUE EVENING.
THE SFC HIGH PRESSURE RIDGE AXIS WAS OVER THE AREA LATE THIS
EVENING. WINDS WILL BE LIGHT THRU MUCH OF THE OVERNIGHT HOURS AS THE
SFC HIGH DRIFTS ACROSS THE AREA. BY 12Z THE RIDGE AXIS WILL HAVE
MOVED INTO EASTERN WI...WITH WINDS BECOMING SOUTH TO SOUTHEAST AND
INCREASING LATE TONIGHT AND THRU TUE MORNING. BY TUE AFTERNOON THE
HIGH WILL BE IN OH. A TIGHT PRESSURE GRADIENT WILL ONCE AGAIN BE
OVER THE UPPER MIDWEST BY TUE AFTERNOON AND FOR TUE NIGHT. BY TUE
AFTERNOON SOUTHEAST-SOUTH WINDS WILL INCREASE INTO THE 10-20KT G20-
30KT RANGE. THESE WINDS WILL CONTINUE TUE NIGHT...BUT AS THE NIGHT-
TIME INVERSION DEVELOPS...WINDS 1500-2000FT AGL ARE GOING TO
INCREASE INTO THE 50KT RANGE FROM THE SOUTH-SOUTHWEST. INCLUDED LLWS
AT KLSE AFTER 00Z WED.
THE AIRMASS WITH THE HIGH AND ON THE BACK SIDE OF THE HIGH IS DRY.
SKC EXPECTED TONIGHT...MAINLY SCT-BKN HIGH CLOUDS TUE THEN SCT 8K-
10K FT CLOUDS TUE NIGHT...WITH VFR VSBYS THRU THE PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
358 AM PST Tue Nov 19 2013
.Synopsis...
A moist system from the Pacific Ocean will continue widespread
precipitation across interior northern California through the
middle of the week.
&&
.Discussion...
Strong zonal flow continues over the EPAC with 120-130 kt upper
jet aligned along and south of 40N. Initial frontal band and
moisture plume (TPW of 1 to 1.25 inches) has moved inland across
NORCAL overnight, but its progress southward is stalling. Much of
the northern half of the Sacramento Valley has received 1 to 2
tenths of an inch of rain since Monday evening while the
mountains to the north of Redding have seen around 1/4 to 1/2
inch. Areas further to the south including the Sacramento area
have seen much lighter rainfall amounts with only a trace to a few
hundredths of an inch reported so far.
Snow levels will start out around 6000 to 6500 feet early this
morning, but are expected to rise over 7000 to 7500 feet later
today as warm advection increases and drier air is mixed out. The
higher elevation northern Sierra passes may see an inch or so of
slushy accumulation today.
Appears and front and moisture plume will stall out over the area
today, and with weak forcing only light amounts of QPF are
expected. Hi-res HRRR indicates a brief break early this morning
over the southern Sacramento Valley with more light precip
spreading into the region around 16Z. Some enhancement of precip
is expected by late this afternoon into Wednesday as the next
short-wave approaches leading to a little stronger lift across the
region.
Front forecast to shift south of the region Wednesday as a
stronger short-wave moves through. Precip expected to turn more
showery across the region, and appears there may be a chance for
thunderstorms across the southern half of the forecast area as the
short-wave moves through during the middle of the day.
Snow levels expected to remain high (generally at or above 7000
feet through Wednesday), so significant snow accumulation will be
limited to the crest of the northern Sierra. 60 hour snow
accumulations from today into early Thursday may approach 10
inches around the 8000 ft level and above.
Showers are expected to end over much of the interior of NORCAL
by early Thursday as the trough digs southward and closes off
vicinity of SOCAL. There may be some lingering showers through the
day along the northern Sierra crest south of Lake Tahoe due to
cyclonic (or backwash) flow of the upper low. By the end of the
day on THU...anticyclonic flow aloft over the nrn portion of the
CWA should begin to clear/erode cloud cover.
With moist ground and ridging developing late in the week...we
would be thinking about valley stratus/fog. However...at this time
strong enough pressure gradients should result in a katabatic wind
precluding fog/stratus formation most areas.
&&
.Extended Discussion (Saturday through Tuesday)...
Areas breezy to windy northeast to east winds continue over
interior NorCal Saturday as positively tilted upper ridge builds
inland. Pressure gradient weakens Sunday with lighter wind. Upper
ridge persists over Northern Cal through the weekend into early
next week bringing dry weather with slightly above normal
temperatures.
&&
.Aviation...
Wdsprd MVFR/IFR conds tda into Wed in pcpn with lcl LIFR omtns.
Snow lvls genly aoa 060. Isold tstms poss ovr srn hlf of fcst area
Wed aftn. W flow alf with Sly wnds up to 20 kts nr sfc tda into
tngt with Lcl SW sfc wnd gsts up to 35 kts ovr hyr mtn trrn.
&&
.STO Watches/Warnings/Advisories...None.
&&
$$
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
945 AM EST TUE NOV 19 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD TODAY THEN TO NEW ENGLAND ON
WEDNESDAY. LOW PRESSURE WILL TRACK OUT OF THE PLAINS LATE FRIDAY
INTO SATURDAY AND PULL A STRONG COLD FRONT ACROSS THE AREA. HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE TOWARDS THE OHIO VALLEY
ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A CLEARING TREND CAN BE SEEN UPSTREAM ACROSS MICHIGAN AND HAVE
TRIED TO TIME THIS INTO OHIO THROUGH MID-DAY. CLOUDS MAY
EXPERIENCE SOME DIURNAL ENHANCEMENT TOWARDS LATE MORNING...WITH
THE DECREASING TREND RESUMING DURING THE AFTERNOON. NO SIGNIFICANT
DEVIATION FROM THIS WITH THE MID MORNING UPDATE.
PREVIOUS DISCUUSION...HIGH PRESSURE WILL CONTINUE TO BUILD IN
FROM THE WEST TODAY WHILE A TROUGH LINGERS OVER QUEBEC. WE HAD
LITTLE IN THE WAY OF LAKE EFFECT SNOW OVERNIGHT WITH RIDGING OVER
ALL BUT ABOUT THE EASTERN THIRD OF LAKE ERIE. SOME LIGHT SNOW
SHOWERS THAT WERE FOCUSED TOWARDS NEW YORK MAY SHIFT WESTWARD INTO
MAINLY NW PA AS WINDS THROUGH 850MB BECOME MORE NORTHERLY THIS
MORNING. AFTER THAT TIME THE MOISTURE DEPTH DECREASES WITH
STRENGTHENING SUBSIDENCE AND SHOWERS WILL COME TO AN END. NO
ACCUMULATION EXPECTED.
MOST MODELS NOT HANDLING THE CLOUD FIELD VERY WELL OVER THE
REGION. INVERSION HEIGHTS LOWER TODAY AS THE HIGH BUILDS OVERHEAD
AND THE RUC SEEMS TO BE DOING THE BEST WITH WITH HIGH 925MB
MOISTURE THROUGH THE DAY. WILL FAVOR A MORE PESSIMISTIC CLOUD
FORECAST WITH CLOUDS EVENTUALLY SCATTERING OUT THIS EVENING. HIGHS
WILL ONLY RECOVER A FEW DEGREES WITH COOL NORTHERLY FLOW WITH
HIGHS IN THE UPPER 30S/LOW 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
QUIET WEATHER WILL CONTINUE ON WEDNESDAY AS WE REMAIN UNDER THE
INFLUENCE OF HIGH PRESSURE EXTENDING FROM NEW ENGLAND. THERE WILL BE
SOME INCREASE IN CIRRUS AS THE UPPER LEVEL RIDGE SHIFTS EAST OF THE
AREA. WITH FLOW SHIFTING AROUND TO THE SOUTHEAST AND PERIODS OF
SUN...TEMPERATURES WILL RECOVER TO THE MID AND UPPER 40S.
UPPER LEVEL JET ENERGY APPROACHING CALIFORNIA WILL CARVE OUT A BROAD
TROUGH OVER THE WESTERN UNITED STATES WHILE A MORE COMPACT TROUGH
NEAR BRITISH COLUMBIA MOVES THROUGH THE NORTHERN STREAM. MOISTURE
WILL INCREASE OVER THE REGION FROM WEDNESDAY NIGHT INTO THURSDAY AS
SHORTWAVE ENERGY MOVES OUT OF THE TROUGH TO OUR WEST AND
SOUTHWESTERLY FLOW INCREASES. IT WILL TAKE A WHILE TO MOISTEN THE
ATMOSPHERE AND WILL ONLY CARRY LOW POPS...MAINLY IN THE WEST THROUGH
THURSDAY. CHANCES OF PRECIPITATION THEN INCREASE FROM THURSDAY NIGHT
THROUGH FRIDAY NIGHT AS LOW PRESSURE MOVES NORTHEAST ACROSS THE AREA
IN ADVANCE OF THE STRENGTHENING TROUGH OVER CANADA. THE GFS IS
CONSIDERABLY STRONGER WITH THE SURFACE LOW AND LEAD PIECE OF UPPER
LEVEL ENERGY AND AN OUTLIER FROM SEVERAL OF THE OTHER LONG RANGE
MODELS AND OTHER GFS ENSEMBLE MEMBERS. WILL LEAN THE BETTER
CONSENSUS FOR NOW WITH A WEAKER SURFACE WAVE WHICH IS A LITTLE
SLOWER AND LESS ROBUST WITH PRECIPITATION.
PRECIPITAITON WILL LARGELY BE A RESULT OF ISENTROPIC ASCENT ON
THURSDAY NIGHT AND FRIDAY AND WILL BE ALL RAIN AS 850MB TEMPS WARM
TO 6C. FRONTOGENESIS STRENGTHENS ACROSS NW OHIO BY FRIDAY NIGHT AND
WILL INCLUDE A RAIN/SNOW MIX AS THERMAL PROFILES START TO COOL.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
WINTER IS GOING TO GET GOING OVER THE WEEKEND. THE MODELS CONTINUE
TO COME INTO BETTER AGREEMENT. BY THE START OF THE PERIOD VERY
STRONG COLD AIR ADVECTION WILL BE OCCURRING. PRECIP APPEARS LIKELY
ON SATURDAY WITH A TRANSITION FROM RAIN TO SNOW OCCURRING AS THE DAY
PROGRESSES. THE NEW GUIDANCE STILL DROPS 850 MB TEMPS TO NEG 16 BY
12Z SUNDAY AND IT APPEARS THAT THE SNOWBELT COULD SEE A GOOD LAKE
EFFECT EVENT. EVEN WESTERN AREAS COULD SEE SOME SNOW SHOWERS FROM
LAKE MICHIGAN. HAVE ONLY MADE MINOR ADJUSTMENTS TO THE PRECIP
FORECAST AS THE PREVIOUS PACKAGE ALREADY HAD LIKELY POPS IN.
SURFACE RIDGING WILL BEGIN TO OCCUR SUNDAY NIGHT INTO MONDAY AND
THIS SHOULD END THE SNOW THREAT. IF CURRENT TRENDS HOLD...SUSPECT
THAT SOME SORT OF WINTER WEATHER HEADLINES WILL BE NEEDED FOR
SUNDAY. HIGHS SUNDAY WILL BE ALMOST 20 DEGREES BELOW NORMAL WITH
READINGS STRUGGLING TO GET ABOVE 30 DEGREES. IT WILL ONLY BE A TAD
WARMER ON MONDAY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
STRATO CU CIGS CONTINUE TO BLANKET THE AREA THIS MORNING.
STARTING TO SEE THE CLOUDS BREAK UP OVER LOWER MICHIGAN AND EXPECT
CLEARING TO BEGIN ACROS THE AREA LATER THIS MORNING. IT WILL
LIKELY TAKE TILL LATE IN THE DAY BEFORE KERI AND KYNG LOSE THEIR
CIGS. FOR THE MOST PART CIGS SHOULD BE VFR THIS MORNING BUT A
COUPLE OF POCKETS OF MVFR REMAIN. THESE SHOULD LIFT SHORTLY. NW
FLOW WILL BECOME N THIS AFTERNOON AND THEN LIGHT AND VARIABLE
OVERNIGHT. THE SECOND HALF OF THE TAF PERIOD SHOULD BE MAINLY
CLEAR.
OUTLOOK...NON VFR POSSIBLE THURSDAY.
&&
.MARINE...
STILL SEEING SUSTAINED WINDS IN THE 20 TO 25 KNOT RANGE SO WILL KEEP
THE SMALL CRAFT HEADLINES GOING AS IS. SPEEDS SHOULD DIMINISH
QUICKLY THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. THE FLOW WILL
BECOME SE TONIGHT AS THE SURFACE RIDGE MOVES EAST OF THE LAKE. SE
TO S FLOW IS THEN EXPECTED INTO THE END OF THE WEEK. LOW PRESSURE
WILL EVENTUALLY CROSS THE REGION SOMETIME FRIDAY PULLING ANOTHER
ARCTIC COLD FRONT ACROSS THE LAKE. STRONG WESTERLY WINDS WILL
DEVELOP BEHIND THE FRONT AND SPEEDS COULD GET CLOSE TO GALE FORCE IN
THE STRONG COLD AIR ADVECTION. THE STRONG FLOW WILL BECOME
NORTHWEST ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LEZ148-
149.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/OUDEMAN
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
652 AM EST TUE NOV 19 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD TODAY THEN TO NEW ENGLAND ON
WEDNESDAY. LOW PRESSURE WILL TRACK OUT OF THE PLAINS LATE FRIDAY
INTO SATURDAY AND PULL A STRONG COLD FRONT ACROSS THE AREA. HIGH
PRESSURE OVER THE NORTHERN PLAINS WILL MOVE TOWARDS THE OHIO VALLEY
ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A CLEARING TREND CAN BE SEEN UPSTREAM ACROSS MICHIGAN AND HAVE
TRIED TO TIME THIS INTO OHIO THROUGH MID-DAY. CLOUDS MAY
EXPERIENCE SOME DIURNAL ENHANCEMENT TOWARDS LATE MORNING...WITH
THE DECREASING TREND RESUMING DURING THE AFTERNOON.
PREVIOUS DISCUUSION...HIGH PRESSURE WILL CONTINUE TO BUILD IN
FROM THE WEST TODAY WHILE A TROUGH LINGERS OVER QUEBEC. WE HAD
LITTLE IN THE WAY OF LAKE EFFECT SNOW OVERNIGHT WITH RIDGING OVER
ALL BUT ABOUT THE EASTERN THIRD OF LAKE ERIE. SOME LIGHT SNOW
SHOWERS THAT WERE FOCUSED TOWARDS NEW YORK MAY SHIFT WESTWARD INTO
MAINLY NW PA AS WINDS THROUGH 850MB BECOME MORE NORTHERLY THIS
MORNING. AFTER THAT TIME THE MOISTURE DEPTH DECREASES WITH
STRENGTHENING SUBSIDENCE AND SHOWERS WILL COME TO AN END. NO
ACCUMULATION EXPECTED.
MOST MODELS NOT HANDLING THE CLOUD FIELD VERY WELL OVER THE
REGION. INVERSION HEIGHTS LOWER TODAY AS THE HIGH BUILDS OVERHEAD
AND THE RUC SEEMS TO BE DOING THE BEST WITH WITH HIGH 925MB
MOISTURE THROUGH THE DAY. WILL FAVOR A MORE PESSIMISTIC CLOUD
FORECAST WITH CLOUDS EVENTUALLY SCATTERING OUT THIS EVENING. HIGHS
WILL ONLY RECOVER A FEW DEGREES WITH COOL NORTHERLY FLOW WITH
HIGHS IN THE UPPER 30S/LOW 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
QUIET WEATHER WILL CONTINUE ON WEDNESDAY AS WE REMAIN UNDER THE
INFLUENCE OF HIGH PRESSURE EXTENDING FROM NEW ENGLAND. THERE WILL BE
SOME INCREASE IN CIRRUS AS THE UPPER LEVEL RIDGE SHIFTS EAST OF THE
AREA. WITH FLOW SHIFTING AROUND TO THE SOUTHEAST AND PERIODS OF
SUN...TEMPERATURES WILL RECOVER TO THE MID AND UPPER 40S.
UPPER LEVEL JET ENERGY APPROACHING CALIFORNIA WILL CARVE OUT A BROAD
TROUGH OVER THE WESTERN UNITED STATES WHILE A MORE COMPACT TROUGH
NEAR BRITISH COLUMBIA MOVES THROUGH THE NORTHERN STREAM. MOISTURE
WILL INCREASE OVER THE REGION FROM WEDNESDAY NIGHT INTO THURSDAY AS
SHORTWAVE ENERGY MOVES OUT OF THE TROUGH TO OUR WEST AND
SOUTHWESTERLY FLOW INCREASES. IT WILL TAKE A WHILE TO MOISTEN THE
ATMOSPHERE AND WILL ONLY CARRY LOW POPS...MAINLY IN THE WEST THROUGH
THURSDAY. CHANCES OF PRECIPITATION THEN INCREASE FROM THURSDAY NIGHT
THROUGH FRIDAY NIGHT AS LOW PRESSURE MOVES NORTHEAST ACROSS THE AREA
IN ADVANCE OF THE STRENGTHENING TROUGH OVER CANADA. THE GFS IS
CONSIDERABLY STRONGER WITH THE SURFACE LOW AND LEAD PIECE OF UPPER
LEVEL ENERGY AND AN OUTLIER FROM SEVERAL OF THE OTHER LONG RANGE
MODELS AND OTHER GFS ENSEMBLE MEMBERS. WILL LEAN THE BETTER
CONSENSUS FOR NOW WITH A WEAKER SURFACE WAVE WHICH IS A LITTLE
SLOWER AND LESS ROBUST WITH PRECIPITATION.
PRECIPITAITON WILL LARGELY BE A RESULT OF ISENTROPIC ASCENT ON
THURSDAY NIGHT AND FRIDAY AND WILL BE ALL RAIN AS 850MB TEMPS WARM
TO 6C. FRONTOGENESIS STRENGTHENS ACROSS NW OHIO BY FRIDAY NIGHT AND
WILL INCLUDE A RAIN/SNOW MIX AS THERMAL PROFILES START TO COOL.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
WINTER IS GOING TO GET GOING OVER THE WEEKEND. THE MODELS CONTINUE
TO COME INTO BETTER AGREEMENT. BY THE START OF THE PERIOD VERY
STRONG COLD AIR ADVECTION WILL BE OCCURRING. PRECIP APPEARS LIKELY
ON SATURDAY WITH A TRANSITION FROM RAIN TO SNOW OCCURRING AS THE DAY
PROGRESSES. THE NEW GUIDANCE STILL DROPS 850 MB TEMPS TO NEG 16 BY
12Z SUNDAY AND IT APPEARS THAT THE SNOWBELT COULD SEE A GOOD LAKE
EFFECT EVENT. EVEN WESTERN AREAS COULD SEE SOME SNOW SHOWERS FROM
LAKE MICHIGAN. HAVE ONLY MADE MINOR ADJUSTMENTS TO THE PRECIP
FORECAST AS THE PREVIOUS PACKAGE ALREADY HAD LIKELY POPS IN.
SURFACE RIDGING WILL BEGIN TO OCCUR SUNDAY NIGHT INTO MONDAY AND
THIS SHOULD END THE SNOW THREAT. IF CURRENT TRENDS HOLD...SUSPECT
THAT SOME SORT OF WINTER WEATHER HEADLINES WILL BE NEEDED FOR
SUNDAY. HIGHS SUNDAY WILL BE ALMOST 20 DEGREES BELOW NORMAL WITH
READINGS STRUGGLING TO GET ABOVE 30 DEGREES. IT WILL ONLY BE A TAD
WARMER ON MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
STRATO CU CIGS CONTINUE TO BLANKET THE AREA THIS MORNING.
STARTING TO SEE THE CLOUDS BREAK UP OVER LOWER MICHIGAN AND EXPECT
CLEARING TO BEGIN ACROS THE AREA LATER THIS MORNING. IT WILL
LIKELY TAKE TILL LATE IN THE DAY BEFORE KERI AND KYNG LOSE THEIR
CIGS. FOR THE MOST PART CIGS SHOULD BE VFR THIS MORNING BUT A
COUPLE OF POCKETS OF MVFR REMAIN. THESE SHOULD LIFT SHORTLY. NW
FLOW WILL BECOME N THIS AFTERNOON AND THEN LIGHT AND VARIABLE
OVERNIGHT. THE SECOND HALF OF THE TAF PERIOD SHOULD BE MAINLY
CLEAR.
OUTLOOK...NON VFR POSSIBLE THURSDAY.
&&
.MARINE...
STILL SEEING SUSTAINED WINDS IN THE 20 TO 25 KNOT RANGE SO WILL KEEP
THE SMALL CRAFT HEADLINES GOING AS IS. SPEEDS SHOULD DIMINISH
QUICKLY THIS AFTERNOON AS HIGH PRESSURE BUILDS IN. THE FLOW WILL
BECOME SE TONIGHT AS THE SURFACE RIDGE MOVES EAST OF THE LAKE. SE
TO S FLOW IS THEN EXPECTED INTO THE END OF THE WEEK. LOW PRESSURE
WILL EVENTUALLY CROSS THE REGION SOMETIME FRIDAY PULLING ANOTHER
ARCTIC COLD FRONT ACROSS THE LAKE. STRONG WESTERLY WINDS WILL
DEVELOP BEHIND THE FRONT AND SPEEDS COULD GET CLOSE TO GALE FORCE IN
THE STRONG COLD AIR ADVECTION. THE STRONG FLOW WILL BECOME
NORTHWEST ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR LEZ148-
149.
SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR
LEZ144>147.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC
SHORT TERM...KEC
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
515 AM CST TUE NOV 19 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
AT 3 AM...A 1027 MB HIGH WAS CENTERED OVER NORTHERN ILLINOIS.
THE 19.00Z MODELS ARE IN GOOD AGREEMENT THAT THE HIGH WILL MOVE
NORTHEAST INTO LOWER MICHIGAN TODAY AND INTO NORTHERN NEW YORK
STATE BY WEDNESDAY MORNING. AS THIS OCCURS...SOUTH WINDS WILL
DEVELOP AND INCREASE INTO THE 10 TO 20 MPH RANGE THIS
MORNING...AND INTO THE 15 TO 25 MPH RANGE THIS AFTERNOON AND
CONTINUE INTO TONIGHT. AS USUAL...THE NAM IS MUCH HIGHER THAN THE
RUC AND GFS WITH ITS WIND GUSTS THIS AFTERNOON. THE NAM HAS WIND
GUSTS IN THE 30 TO 40 MPH RANGE. MEANWHILE THE RAP AND GFS HAVE
THEIR WIND GUSTS AROUND 30 MPH. SINCE THE NAM USUALLY IS A BIT TOO
HIGH...TRENDED THE WIND GUSTS TOWARD THE GFS AND RAP. BUFKIT
SOUNDINGS SHOW THAT THE MOISTURE WILL BE GRADUALLY INCREASING
ABOVE 500 MB TODAY. AS A RESULT WENT WITH INCREASING HIGH CLOUDS
THROUGHOUT THE DAY. THESE CLOUDS SHOULD ALLOW ENOUGH SUNSHINE FOR
TEMPERATURES TO APPROACH 50 DEGREES SOUTH OF INTERSTATE 94 AND
INTO THE MID AND UPPER 40S NORTH OF THIS INTERSTATE.
FROM LATE TONIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO SHOW
THAT THE 925 AND 850 MB MOISTURE TRANSPORT WILL INCREASE AHEAD OF
A SHORT WAVE TROUGH MOVING EAST OF THE PLAINS. THE BEST
SATURATION OCCURS ACROSS SOUTHWEST AND CENTRAL WISCONSIN ON
WEDNESDAY. AS A RESULT...WENT WITH THE HIGHEST RAIN CHANCES /40 TO
50 PERCENT/ FOR THIS AREA. RAINFALL AMOUNTS WILL BE LESS THAN A
TENTH OF AND INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
ON WEDNESDAY NIGHT...SUBSIDENCE QUICKLY DEVELOPS IN THE WAKE OF
THE TROUGH. AS THIS OCCURS...THE PRECIPITATION CHANCES QUICKLY
DECLINE DURING THE EVENING.
ON THURSDAY NIGHT...THE OPERATIONAL RUNS OF THE GFS...
ECMWF...AND NAM ARE SHOWING THAT A SOUTHERN AND NORTHERN STREAM
SYSTEM WILL PHASE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE
AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A 100 KNOT POLAR
JET AND THE LEFT EXIT REGION OF A 100 KNOT SUBTROPICAL JET. THESE
COUPLED JETS DRAMATICALLY INCREASE THE LIFT ACROSS THE AREA. DUE
TO THIS...THE MODELS ARE GENERATING MUCH MORE PRECIPITATION ACROSS
THE AREA THAN WHAT SHOWED UP IN PREVIOUS MODEL RUNS. DUE TO
THIS...THE PRECIPITATION CHANCES WERE RAISED UP TO 60 PERCENT.
HOWEVER THESE PRECIPITATION CHANCES ARE HIGHLY DEPENDENT UPON
WHETHER THIS JET COUPLING DOES INDEED OCCURS. 6 OF 12 GFS ENSEMBLE
MEMBERS SHOW THIS OCCURRING. MEANWHILE THE OTHER 6 SHOW THAT THESE
TWO SHORT WAVE TROUGHS WILL NOT PHASE AND THE AREA COULD
POTENTIALLY END UP BEING DRY. THIS IS 3 MORE MEMBERS THAN WHAT
SHOWED UP IN THE 18.18Z GFS ENSEMBLE. AS THESE WAVES MOVES
EAST...COLDER AIR WILL MOVE INTO THE REGION AS THE NIGHT
PROGRESSES AND THE PRECIPITATION WILL CHANGE OVER TO SLEET AND
SNOW. SNOW AMOUNTS COULD POTENTIALLY BE UP TO AN INCH NORTH OF AN
AUSTIN MINNESOTA TO NEILLSVILLE WISCONSIN LINE.
ON FRIDAY AND FRIDAY EVENING...COLDER AIR WILL SINK SOUTHWARD
ACROSS THE AREA. THIS WILL RESULT IN 950 TO 900 LAPSE RATES AROUND
OF 8 TO 9 C/KM. AS A RESULT...CONTINUED LIGHT SNOW CHANCES
THROUGHOUT MUCH OF THIS TIME PERIOD. ADDITIONAL SNOWFALL AMOUNTS
WILL BE LESS THAN A HALF INCH.
ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST REMAINS VERY
TRICKY. THIS IS DUE TO DIFFERING TIMES ON WHEN THE COLDEST AIR
WILL MOVE SOUTHWARD INTO THE FORECAST AREA. BOTH THE GFS AND GEM
HAS THIS AIR MASS ARRIVING MUCH SOONER...SO THEY HAS HIGH
TEMPERATURES REMAINING IN THE TEENS. MEANWHILE THE ECMWF IS A BIT
LATER AND THE HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID 20S.
SINCE THERE WERE SOME DRAMATIC DIFFERENCES...JUST STAYED WITH THE
ALL BLEND MAXIMUM TEMPERATURES.
SATURDAY NIGHT...LOOKS VERY COLD ACROSS THE AREA WITH 925 MB
TEMPERATURES OF -14 TO -16C AND WINDS LIGHTENING THROUGH THE
NIGHT. LOW TEMPERATURES ON SUNDAY MORNING WILL LIKELY BE IN THE
SINGLE DIGITS ACROSS THE AREA. IF WE END UP GETTING MORE SNOW
THAN EXPECTED ON THURSDAY NIGHT...THESE TEMPERATURES MAY BE EVEN
COLDER.
LIKE SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS VERY TRICKY
BECAUSE THE GFS HAD WARM AIR ADVECTION KICKING A BIT FASTER THAN
THE ECMWF. AS A RESULT...THE GFS IS WARMER THAN THE ECMWF. SINCE
IT IS UNCERTAIN ON WHICH MODEL WILL VERIFY THE BEST...JUST STAYED
WITH THE ALL BLEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 515 AM CST TUE NOV 19 2013
PRESSURE GRADIENT WILL TIGHTEN TODAY ON THE BACKSIDE OF AN EASTWARD
MOVING HIGH PRESSURE SYSTEM. WINDS WILL INCREASE QUICKLY - BY
MID/LATE MORNING - FROM A SOUTHERLY DIRECTION. THERE WILL BE SOME
GUSTINESS...BUT MINIMALIZED SOMEWHAT AS LOW LEVEL WINDS ARE NOT
UNDIRECTIONAL AND MIXING IS INHIBITED SOMEWHAT. THE WINDS WILL STAY
UP TONIGHT...WITH BUFKIT SOUNDINGS VIA THE RAP/NAM/GFS ALL POINTING
TO A 50-60 KT 2 KFT JET DEVELOPING BY 03Z. LLWS A CONCERN AS A
RESULT...AND WILL CONTINUE MENTION AT KLSE...AND ADD TO THE TAF FOR
KRST.
SOME HIGH THIN CLOUDS WILL SWEEP ACROSS THE REGION TODAY...WITH SOME
MID 8-10 KFT CLOUDS TONIGHT. VFR CONDITIONS ARE ANTICIPATED INTO
WEDNESDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
311 PM MST TUE NOV 19 2013
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 310 PM MST TUE NOV 19 2013
MOIST LOW AMPLITUDE SHORT WAVE RACES ACROSS NORTHWEST COLORADO
TONIGHT. RADAR SHOWING LOW DBZ RETURNS AS THE MOISTURE INCREASES
THIS AFTERNOON...SOME OF THIS PCPN IS REACHING THE GROUND AS KCAG
MEASURED A TRACE AND SUNLIGHT MOUNTAIN AWOS REPORTS LIGHT SNOW.
THE COMBINATION OF OROGRAPHICS AND WEAK DYNAMICAL FORCING WILL
RESULT IN WIDESPREAD LIGHT PCPN OVERNIGHT ACROSS NW COLORADO...POSSIBLY
EXTENDING AS FAR SOUTH AS THE ELK MOUNTAINS. ENHANCED CLOUD COVER
IN THE INFRARED IS SOMEWHAT FRAGMENTED AND UPSTREAM RADAR
OBSERVATIONS SHOW BROKEN AREAS OF PCPN. THE RAP MODEL SHOW PCPN
EXPANDING AS THE SHORT WAVE GETS LIFTED OVER THE DIVIDE...BUT
APPEARS THAT THE TIME DURATION DOES NOT LAST LONG ENOUGH FOR
ADVISORY CRITERIA SNOWFALL. APPEARS THE ELKHEADS AND PARK RANGE
MAY GET A FEW INCHES OF SNOW TONIGHT...BUT TAPERING OFF AFTER
MIDNIGHT. THE SRN HALF HALF GETS EXTENSIVE CLOUD COVER BUT THE
MOISTURE IS NOT AS DEEP...FLURRIES OR BRIEF LIGHT SNOW MAY OCCUR
OVER THE SAN JUAN MOUNTAINS AS THE SHORT WAVE DRAGS ACROSS WRN
COLORADO.
SATELLITE INFRARED AND WATER VAPOR CLEARLY SHOWS A STREAM OF
MOISTURE FROM NW OF THE HAWAIIAN ISLES TO THE CALIFORNIA COAST.
THE FORECAST AREA MAY GET ONLY ONE SHOT AT THIS MOISTURE AND THAT
OCCURS FROM WEDNESDAY AFTERNOON INTO THURSDAY. BUT SHORT WAVE
ENERGY ADVECTING THIS MOISTURE TO THE FOUR CORNERS REGION IS WEAK
AND FRAGMENTED (SIMILAR TO THE LEAD SHORT WAVE). NO SHORTAGE OF
MOISTURE AS 700 MB SPECIFIC HUMIDITY VALUES EXCEED 4 G/KG...BUT
OTHER FEATURES THAT ARE NEEDED FOR EFFICIENT RAIN OR SNOW PRODUCTION
ARE MISSING. LACKING ELEMENTS INCLUDE BAROCLINICITY AND
DYNAMICAL/OROGRAPHICAL FORCING AS 700 MB GRADIENT FLOW IS LESS
THAN 20 KNOTS. THE AREA OF PRECIPITATION WILL BE EXPANDING
WEDNESDAY AFTERNOON OVER SW COLORADO AND SPREADING NEWD...CURRENT
QPF PROJECTIONS SUGGEST SNOW POTENTIAL OF 4 TO 8 INCHES OVER THE
SAN JUAN AND WRN COLORADO CENTRAL MOUNTAINS. THE DEEPEST MOISTURE
WILL BE POSITIONED ACROSS THE REGION ON WEDNESDAY NIGHT BEFORE
SHIFTING DOWNSTREAM BY THURSDAY MORNING...NOT COINCIDING WITH THE
COLD FRONT SURGING SOUTHWARD NEAR THE WYOMING BORDER. SNOW LEVELS
A BIT TRICKY AND WILL BE FLUCTUATING DEPENDING ON TIME OF DAY. IN
GENERAL TERMS...SNOW LEVELS WILL RANGE FROM 7000 TO 8000 FEET.
DIABATIC COOLING PROCESSES COULD RESULT IN WET SNOW TO NEAR THE
VALLEY FLOORS LATE WEDNESDAY NIGHT. LATER SHIFTS MAY NEED TO
CONSIDER HOISTING WINTER WEATHER ADVISORIES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 310 PM MST TUE NOV 19 2013
BY THU THE SPLIT IN THE FLOW WILL BECOME MORE DISTINCT AS THE LOW
BEGINS TO CLOSE OFF ROUGHLY OVER SOUTHERN CALIFORNIA. A MOIST AND
UNSETTLED SOUTHWEST FLOW AHEAD OF THE LOW WILL CONTINUE TO STREAM
OVER THE SOUTHWEST CORNER OF THE CONUS...AND ACROSS THE SOUTHERN
AND CENTRAL ROCKIES. IN ADDITION...A COLD FRONT ASSOCIATED WITH A
NORTHERN BRANCH SHORTWAVE WILL DROP INTO THE NORTHERN EDGE OF THE
CWA BY AROUND MIDDAY. WE CAN EXPECT MOUNTAIN SNOW AND THE CHANCE
FOR VALLEY RAIN TO CONTINUE THROUGH THU. MOST OF THE AREA WILL BE
DOMINATED BY THE MOIST UNSTABLE SOUTHWEST FLOW WITH SOUTH-
SOUTHWEST SLOPES FAVORED IN THIS REGIME. BUT THE OROGRAPHICS WILL
GENERALLY REMAIN ON THE WEAK SIDE AS THE SOUTHWEST FLOW IS NOT
EXPECTED TO BE OVERLY STRONG. OVER THE FAR NORTH HOWEVER...THE
AREA IMPACTED BY THE THE NORTHERN BRANCH COLD FRONT WILL SPREAD
SOUTH/SOUTHEAST. I EXPECT THAT THERE WILL BE A NICE ENHANCEMENT OF
THE PRECIPITATION IN THE VICINITY OF THE FRONT. BUT MODELS
INDICATE MUCH DRIER AIR WILL PUSH IN BEHIND THE FRONT. THIS WILL
BRING A DOWNTURN IN POPS OVER THE NORTHWEST CORNER BY LATE IN THE
AFTERNOON WITH THAT TREND EXTENDING SOUTH-SOUTHWEST THROUGH THE
EVENING. ALSO A LOCALIZED AREA OF STRONG NORTHERLY WINDS WILL
DEVELOP OVER WESTERN MOFFAT COUNTY INTO THE EASTERN UINTA BASIN
DURING THE EVENING. MUCH COLDER TEMPS WILL RESULT IN THIS DRIER
AIR BEHIND THE FRONT. MODELS DISAGREE ON JUST HOW FAR SOUTH THIS
FRONT WILL REACH BEFORE IT WASHES OUT IN THE SOUTHWEST FLOW AHEAD
OF THE SOUTHERN BRANCH LOW. BUT WE CAN CERTAINLY EXPECT MUCH
COLDER TEMPS OVER THE FAR NORTH...WITH LESS COOLING AS ONE TRAVELS
SOUTH.
MODELS AGREE THAT THE LOW WILL STALL IN THE VICINITY OF SAN DIEGO
BY EARLY FRIDAY...THEN PRETTY MUCH REMAIN STATIONARY UNTIL EARLY
SUNDAY. BY SUN AFTERNOON THE LOW BEGINS TO SLOWLY SHIFT
EAST...MAKING IT OVER NM/GFS...TO THE OK PANHANDLE/ECMWF ON
MONDAY. THIS KEEPS THE DESERT SOUTHWEST THROUGH THE SOUTHERN CO
MOUNTAINS UNDER A MOIST UNSETTLED FLOW AHEAD OF THIS LOW...AND
STILL UNSETTLED AS IT PASSES. OVER THE NORTH...MODELS SHOW A COL
AREA BETWEEN THE SOUTHERN BRANCH LOW AND THE NORTHERN BRANCH
NORTHWESTERLIES WILL MORE OR LESS SET UP OVER WY/NORTHERN CO...AND
EXTEND INTO NORTHEAST UT. THIS WILL KEEP THE NORTHERN HALF TO
TWO/THIRDS OF THE CWA ON THE DRY SIDE. BUT OUR SOUTHERN EDGE MAY
CONTINUE TO SEE PRECIPITATION TROUGH MONDAY. EXPECT THERE WILL BE
BREAKS AT TIMES. AND AS ANY EMBEDDED DISTURBANCES MOVE INTO THE
THE AREA... SHOWERS WILL BE ENHANCED.
MODELS ALL AGREE THAT BY TUE...A DRIER NORTH-NORTHWEST FLOW WILL
DOMINATE AREA-WIDE AS A LARGE AREA OF HIGH PRESSURE BUILDS TO OUR
WEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 310 PM MST TUE NOV 19 2013
MOUNTAIN TOPS WILL BE FREQUENTLY OBSCURED THROUGH THE NIGHT WITH
WIDESPREAD -RA/-SN NORTH OF A LINE FROM KVEL-KRIL-KASE-K7BM. AREAS
OF IFR CIGS/VIS WILL BE POSSIBLE NORTH OF THIS LINE. SNOW LEVELS
WILL BE LOWERING TO NEAR THE VALLEY FLOORS OR AROUND 5500 FEET.
VFR WITH AREA OF MVFR IS EXPECTED TONIGHT SOUTH OF A LINE FROM
KVEL-KGJT-KMTJ-KGUC. MOUNTAIN AREAS MAY BE PARTLY OBSCURED TONIGHT.
AFTER 12Z WEDNESDAY...VFR ALL TAF SITES EXCEPT LOWERING CIGS IN
THE AFTERNOON.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...PF
LONG TERM...EH
AVIATION...PF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
121 PM EST TUE NOV 19 2013
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS FLURRIES AND EVEN SOME PATCHY FREEZING
DRIZZLE WILL GRADUALLY COME TO AN END EARLY THIS AFTERNOON AS HIGH
PRESSURE SLOWLY BUILDS INTO THE REGION. BRISK NORTHWEST WINDS
COMBINED WITH ABUNDANT CLOUD COVER WILL KEEP TEMPERATURES MAINLY
IN THE MIDDLE TO UPPER 30S FOR DAYTIME HIGHS THIS AFTERNOON ACROSS
CENTRAL NEW YORK...WITH UPPER 30S TO LOWER 40S ACROSS NORTHEAST
PENNSYLVANIA. HIGH PRESSURE WILL THEN DOMINATE THE WEATHER PATTERN
WITH DRY AND SLOWLY MODERATING TEMPERATURES EXPECTED THROUGH THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADARS STILL SHOW PERSISTENT LAKE EFFECT SNOW SHOWERS/FLURRIES AND
DRIZZLE OR EVEN FREEZING DRIZZLE DOWNWIND OF LAKE ONTARIO. THE
LOW-LEVEL FLOW WAS ABT FROM 310 DEGREES AND CONTS TO DIRECT LAKE
EFFECT MOISTURE INTO THE HILLS OF CENTRAL NY AND FAR NE PA AS OF
LATE THIS MORNING. MEANWHILE ALOFT THERE WAS STRG SYNOPTIC SCALE SUBSC
ASSCTD WITH THE PASSAGE OF THE UPPER LEVEL TROF AXIS TO THE EAST
INTO NEW ENGLAND.
MODEL SOUNDINGS BETWEEN THE NAM...GFS AND RAP DIVERGE AS TO HOW
THE BNDRY LAYER MOISTURE WILL EVOLVE THIS AFTERNOON INTO THE EVENING.
THE NAM RAPIDLY CLEARS OUT THE AREA THIS AFTERNOON WITH
SIGNIFICANT LL DRY AIR ADVECTION. THE RAP HOLDS ONTO THE MOISTURE
TRAPPED BELOW THE INVERSION INTO THE EVENING HOURS. THE GFS IS IN
BETWEEN. LOOKING AT THE VSBL SATELLITE IMAGERY I AM LEANING TWD
THE RAP AS THERE WAS SIGNIFICANT CLD CVR N OF LAKE ONTARIO IN ERN
ONT AND QUE. SFC DWPTS DO COME DOWN DURG THE AFTERNOON BUT THE
SATELLITE IMAGERY STILL SHOWS CLD CVR EVEN WITH THE DROP IN SFC
DWPTS UPSTREAM. THIS DRIER SFC AIR WILL ADVECT SOUTHWARD THIS
AFTERNOON AND SHUD SNUFF OUT THE LAKE EFFECT SNOW SHOWERS AND
DZ/FZDZ BY 19Z THE LATEST.
ISSUED AN SPS EARLIER FOR PATCHY FZDZ WHICH IS ASSCTD WITH THE
LAKE EFFECT MOISTURE. FZDZ WAS CONFIRMED BY SOME OF OUR FACEBOOK
FANS OVER THE HIGHER TERRAIN IN C NY. CLD TOPS OUTSIDE THE LAKE
EFFECT SNOW BANDS WERE TOO SHALLOW FOR GLACIATION AND HENCE WE ARE
SEEING SOME PATCHY DRIZZLE. HIGHER TERRAIN AREAS REMAIN AT OR
BELOW FREEZING WITH PATCHY FZDZ AT TIMES. WILL REISSUE SPS SHORTLY TO
HIGHLIGHT THE END OF THE FREEZING DRIZZLE AND PRECIP.
CLD CVR SHUD HANG ON DOWNWIND OF LAKE ONTARIO WELL INTO THE EVE AS
PER RAP SOUNDINGS. GIVEN THE NW FLOW AND TRAJECTORIES ACRS LAKE
ONTARIO AND PRESENT CLD CVR UPSTREAM FROM THE LAKES IN
CANADA...HARD TO SEE CLRG IN THE HILLS OF C NY OR FAR NE PA B4 6Z.
SO WILL HANG ONTO CLDS SIMILAR TO THE 925 MB RH FIELDS ON THE RAP.
EVENTUALLY LATER TONIGHT...THE FLOW TURNS MORE N-NERLY AND THIS
IS WHEN CLRG SHUD FINALLY TAKE PLACE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
A VERY QUIET SHORT TERM PERIOD ANTICIPATED AS HIGH PRESSURE
REMAINS IN FIRM CONTROL. BY WEDNESDAY...SE FLOW WILL INCREASE AS
HIGH PRESSURE SLIDES TO OUR EAST. EXPECT A WARMER DAY THAN TODAY
WITH MOST PLACES EXPECTED TO WARM INTO THE LWR TO MIDDLE 40S FOR
HIGHS. SIMILAR CONDITIONS EXPECTED ON THURSDAY AS 850-HPA TEMPS
SLOWLY BEGIN WARMING IN DEVELOPING SOUTHWEST FLOW ALOFT. PRECIP TO
MAKE A POSSIBLE RETURN THU NGT/EARLY FRI AS WARM AIR ADVECTION
INTERACTS WITH A NORTHWARD LIFTING WARM FRONT LIFTING NORTH
THROUGH THE OHIO VLY. FOR NOW...HAVE CAPPED POPS IN THE SLGT CHC
CATEGORY AS BEST ISENTROPIC ASCENT IS EXPECTED WELL WEST OF OUR
REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
115 PM TUE UPDATE...
GENERALLY USED WPC GUIDANCE EXCEPT FOR LOCALIZED ENHANCEMENTS TO
POP AND SKY GRIDS FOR WHEN LAKE EFFECT SNOW WILL BE FAVORABLE.
INTERESTING PATTERN TAKING SHAPE WITH INCREASING CONFIDENCE FOR
SOLID SHOT OF ARCTIC AIR /COLDEST OF SEASON SO FAR/ DURING SECOND
HALF OF WEEKEND...AND FOR LAKE EFFECT SNOW. DETAILS OF THAT SNOW
OF COURSE WILL BE RESOLVED IN COMING DAYS...BUT IN THE BIG PICTURE
IT LOOKS FAVORABLE WITHIN OUR GENERAL AREA AND FORECAST HAS BEEN
ADJUSTED ACCORDINGLY WITH BEST CHANCES SUNDAY IN CENTRAL NEW YORK.
BEFORE THEN HOWEVER...TIMING OF INITIAL COLD FRONT LOOKS LIKELY
FOR SOMETIME FRIDAY NIGHT/EARLY SATURDAY. FRONTAL PRECIPITATION
WILL PROBABLY BE MAINLY RAIN. COLD AIR ADVECTION OCCURS DURING THE
DAY...ALLOWING LINGERING RAIN SHOWERS TO MIX WITH SNOW...THOUGH
AMOUNTS PROBABLY LIMITED BY THEN DUE TO DRY SLOTTING /LOSS OF
DEEPER MOISTURE/. ARCTIC FRONT WILL THEN BLAST THROUGH SOMETIME
SATURDAY NIGHT...PLUMMETING 850MB TEMPERATURES INTO AT LEAST THE
MID TEENS BELOW ZERO ON SUNDAY. WITH THE ARCTIC AIR MASS APPEARING
TO ADVECT IN FROM WNW INSTEAD OF THE NORTHERLY DIRECTION...AND
WITH THE DENDRITIC GROWTH LAYER BECOMING COMFORTABLY CONTAINED IN
THE LOWEST 8 KFT AGL...IT IS A FAVORABLE SET UP FOR ACCUMULATING
LAKE EFFECT SNOW INCLUDING UPSTREAM LAKE-TO-LAKE CONNECTIONS
SUNDAY INTO PERHAPS SUNDAY NIGHT.
IT HAS BEEN COMMON SO FAR THIS SEASON FOR AN INITIALLY VERY COLD
AIR MASS IN THE MODELS...TO MODERATE AS THE EVENT GETS CLOSER TO
THE POINT THAT IT IS NOT QUITE AS COLD AS ORIGINALLY ANTICIPATED
ONCE IT ARRIVES. HOWEVER...IN THIS CASE...THE MODELS HAVE
INDICATED THE ARCTIC AIR FOR AT LEAST A FEW RUNS AND ARE
MAINTAINING ITS MAGNITUDE IF NOT TRENDING EVEN SLIGHTLY COLDER.
BOTH 12Z GFS AND 00Z ECMWF DIVE 1000-500MB THICKNESSES BELOW 510
DECAMETER RANGE. GFS GUIDANCE TEMPERATURES HAVE NOW TRENDED
TOWARDS THE VERY COLD ECMWF GUIDANCE VALUES. WE NOW EXPECT MOST
LOCATIONS NOT TO GET OUT OF THE 20S FOR HIGHS SUNDAY.
DRY SURFACE RIDGE MONDAY WITH WARM AIR ADVECTION ALOFT...BUT
LIKELY MUCH MORE MUTED AT THE SURFACE AS WOULD BE TYPICAL ON BACK
SIDE OF ARCTIC AIR MASS. SO AFTER MAINLY TEENS FOR LOWS SUNDAY
NIGHT...ONLY UPPER 20S TO MID 30S ANTICIPATED FOR HIGHS MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
18Z UPDATE...
DRY AIR IS TRYING TO FURTHER ENTRENCH INTO THE REGION...BUT
SHALLOW LAYER OF GREAT LAKES MOISTURE REMAINS TRAPPED UNDER
SUBSIDENCE INVERSION FOR AT LEAST A LITTLE LONGER. MVFR...IN SOME
CASES AT FUEL ALT REG LEVEL...WILL PESTER THE TERMINALS THIS
AFTERNOON THROUGH EVENING /SOME LONGER THAN OTHERS WITH TIMING AS
NOTED IN SPECIFIC TAFS/. LAKE EFFECT FLURRIES ALSO STILL POSSIBLE
INITIALLY FOR KITH-KBGM. NNW WINDS GUSTING TO 15-20 KTS THIS
AFTERNOON...THEN SUBSIDING TO LIGHT NE OR VARIABLE OVERNIGHT INTO
WEDNESDAY MORNING. AS THAT FLOW VEERS LIGHT NORTHEASTERLY
OVERNIGHT...ANY REMAINING MVFR CIGS WILL SCATTER OUT AND CLEAR.
VFR FOR REMAINDER OF TAF PERIOD AS HIGH PRESSURE TAKES CHARGE.
OUTLOOK...
WED THROUGH THU...VFR.
FRI...VFR/MVFR. SHOWERS POSSIBLE.
FRI NGT/SAT...RESTRICTIONS POSSIBLE FROM SHRA AS COLD FRONT
PASSES.
SAT NGT/SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT SHSN ESPECIALLY
CENTRAL NY TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...CMG
LONG TERM...MDP
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1127 AM EST TUE NOV 19 2013
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS FLURRIES AND EVEN SOME PATCHY FREEZING
DRIZZLE WILL GRADUALLY COME TO AN END EARLY THIS AFTERNOON AS HIGH
PRESSURE SLOWLY BUILDS INTO THE REGION. BRISK NORTHWEST WINDS
COMBINED WITH ABUNDANT CLOUD COVER WILL KEEP TEMPERATURES MAINLY
IN THE MIDDLE TO UPPER 30S FOR DAYTIME HIGHS THIS AFTERNOON ACROSS
CENTRAL NEW YORK...WITH UPPER 30S TO LOWER 40S ACROSS NORTHEAST
PENNSYLVANIA. HIGH PRESSURE WILL THEN DOMINATE THE WEATHER PATTERN
...WITH DRY AND SLOWLY MODERATING TEMPERATURES EXPECTED THROUGH
THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADARS STILL SHOW PERSISTENT LAKE EFFECT SNOW SHOWERS/FLURRIES AND
DRIZZLE OR EVEN FREEZING DRIZZLE DOWNWIND OF LAKE ONTARIO. THE
LOW-LEVEL FLOW WAS ABT FROM 310 DEGREES AND CONTS TO DIRECT LAKE
EFFECT MOISTURE INTO THE HILLS OF CENTRAL NY AND FAR NE PA AS OF
LATE THIS MORNING. MEANWHILE ALOFT THERE WAS STRG SYNOPTIC SCALE SUBSC
ASSCTD WITH THE PASSAGE OF THE UPPER LEVEL TROF AXIS TO THE EAST
INTO NEW ENGLAND.
MODEL SOUNDINGS BETWEEN THE NAM...GFS AND RAP DIVERGE AS TO HOW
THE BNDRY LAYER MOISTURE WILL EVOLVE THIS AFTERNOON INTO THE EVENING.
THE NAM RAPIDLY CLEARS OUT THE AREA THIS AFTERNOON WITH
SIGNIFICANT LL DRY AIR ADVECTION. THE RAP HOLDS ONTO THE MOISTURE
TRAPPED BELOW THE INVERSION INTO THE EVENING HOURS. THE GFS IS IN
BETWEEN. LOOKING AT THE VSBL SATELLITE IMAGERY I AM LEANING TWD
THE RAP AS THERE WAS SIGNIFICANT CLD CVR N OF LAKE ONTARIO IN ERN
ONT AND QUE. SFC DWPTS DO COME DOWN DURG THE AFTERNOON BUT THE
SATELLITE IMAGERY STILL SHOWS CLD CVR EVEN WITH THE DROP IN SFC
DWPTS UPSTREAM. THIS DRIER SFC AIR WILL ADVECT SOUTHWARD THIS
AFTERNOON AND SHUD SNUFF OUT THE LAKE EFFECT SNOW SHOWERS AND
DZ/FZDZ BY 19Z THE LATEST.
ISSUED AN SPS EARLIER FOR PATCHY FZDZ WHICH IS ASSCTD WITH THE
LAKE EFFECT MOISTURE. FZDZ WAS CONFIRMED BY SOME OF OUR FACEBOOK
FANS OVER THE HIGHER TERRAIN IN C NY. CLD TOPS OUTSIDE THE LAKE
EFFECT SNOW BANDS WERE TOO SHALLOW FOR GLACIATION AND HENCE WE ARE
SEEING SOME PATCHY DRIZZLE. HIGHER TERRAIN AREAS REMAIN AT OR
BELOW FREEZING WITH PATCHY FZDZ AT TIMES. WILL REISSUE SPS SHORTLY TO
HIGHLIGHT THE END OF THE FREEZING DRIZZLE AND PRECIP.
CLD CVR SHUD HANG ON DOWNWIND OF LAKE ONTARIO WELL INTO THE EVE AS
PER RAP SOUNDINGS. GIVEN THE NW FLOW AND TRAJECTORIES ACRS LAKE
ONTARIO AND PRESENT CLD CVR UPSTREAM FROM THE LAKES IN
CANADA...HARD TO SEE CLRG IN THE HILLS OF C NY OR FAR NE PA B4 6Z.
SO WILL HANG ONTO CLDS SIMILAR TO THE 925 MB RH FIELDS ON THE RAP.
EVENTUALLY LATER TONIGHT...THE FLOW TURNS MORE N-NERLY AND THIS
IS WHEN CLRG SHUD FINALLY TAKE PLACE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A VERY QUIET SHORT TERM PERIOD ANTICIPATED AS HIGH PRESSURE
REMAINS IN FIRM CONTROL. BY WEDNESDAY...SE FLOW WILL INCREASE AS
HIGH PRESSURE SLIDES TO OUR EAST. EXPECT A WARMER DAY THAN TODAY
WITH MOST PLACES EXPECTED TO WARM INTO THE LWR TO MIDDLE 40S FOR
HIGHS. SIMILAR CONDITIONS EXPECTED ON THURSDAY AS 850-HPA TEMPS
SLOWLY BEGIN WARMING IN DEVELOPING SOUTHWEST FLOW ALOFT. PRECIP TO
MAKE A POSSIBLE RETURN THU NGT/EARLY FRI AS WARM AIR ADVECTION
INTERACTS WITH A NORTHWARD LIFTING WARM FRONT LIFTING NORTH
THROUGH THE OHIO VLY. FOR NOW...HAVE CAPPED POPS IN THE SLGT CHC
CATEGORY AS BEST ISENTROPIC ASCENT IS EXPECTED WELL WEST OF OUR
REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LATEST GFS AND ECMWF MODEL RUNS SUGGEST AT LEAST A SHORT TERM PATTERN
CHANGE FOR THE UPCOMING WEEKEND AS A HIGH AMPLITUDE 500 MB TROF IS
FORECAST TO DIG ACROSS THE NORTHEASTERN CONUS. DIFFERENCES EXIST
IN TIMING AND STRENGTH OF THE FEATURES ALOFT AND AT THE SURFACE...BUT
SUFFICE IT TO SAY THE FRI-SAT TIME FRAME LOOKS TO HAVE A HIGH POTENTIAL
FOR INCLEMENT WEATHER. THE SFC LOW TRACK CURRENTLY SUGGESTS A PASSAGE
RIGHT OVER THE CWA WHICH COULD BRING SOME WINTRY PRECIP TO THE REGION...
ALTHOUGH THERMAL PROFILES ONLY SEEM TO SUGGEST A RAIN OR WET SNOW ENVIRONMENT
FROM FRI-SAT AS WET BULB TEMPS APPEAR TO BE WELL ABOVE ZERO IN THE BOUNDARY
LAYER. IN SOME RESPECTS...THE MOS GUIDANCE TEMPS MAY BE A BIT TOO
COLD AT NIGHT ON FRIDAY NIGHT...AND AGAIN SATURDAY NIGHT. AT THIS
TIME THERE REMAINS TOO MUCH UNCERTAINTY IN HOW MUCH PRE-PRECIPITATION
COOLING WOULD TAKE PLACE FRI EVENING...AND HOW MUCH CAA COOLING MIGHT
OCCUR BEFORE SUNRISE ON SUNDAY AFTER THE FROPA TO MAKE ANY SIGNIFICANT
DEVIATIONS FROM THE MOS NUMBERS...OR OUR PREVIOUS FORECAST. SIGNIFICANTLY
COLDER AIR DOES APPEAR TO BE DRAWN SOUTH AT SOME POINT DURING THE
LATTER HALF OF THE WEEKEND INTO NEXT WEEK WITH DAILY TEMPS AVERAGING
WELL BELOW NORMAL ALONG WITH GOOD PROBABILITIES FOR NORTHWESTERLY
ORIENTED LAKE EFFECT SNOWS.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
GNRL VFR CONDS WILL CONT THRU THE TAF PD. NW FLOW OF CAA WILL
PRODUCE CLDS AND SOME LGT LE SNOW AND RAIN SHWRS EARLY. SKIES WILL
CLR AFT 21Z AS DRIER AIR MVES. WINDS WILL CONT TO BE GUSTY THRU
THE DAYLIGHT HRS...THEN BECOME LGTR AFT 00Z THE HIPRES BLDS INTO
THE AREA.
OUTLOOK...
WED THROUGH THU...VFR.
FRI...VFR/MVFR. SHOWERS POSSIBLE.
SAT...MVFR. PERIODS OF RAIN POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...CMG
LONG TERM...JAB
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
319 PM CST TUE NOV 19 2013
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT
QUITE A CHANGE COMING IN THE SHORT TERM FROM THIS AFTERNOON
THROUGH THURSDAY NIGHT. FOR TONIGHT...EXPECT RR QUAD JET INDUCED
HIGH CLOUDS TO MOVE ON THIS EVENING WHILE MORE HIGH CLOUDS SPREAD
IN FROM THE WEST. BREEZY SOUTH WINDS WILL DECREASE THIS EVENING
WITH WINDS BECOMING NORTHWEST THROUGH NORTH BY MORNING AS A WEAK
SURFACE LOW PRESSURE TROUGH MOVES THROUGH. TEMPERATURES WILL NOT
FALL OFF MUCH TONIGHT WITH THE MILD AIR MASS REMAINING. LOWS ARE
EXPECTED TO RANGE FROM AROUND 30 DEGREES NORTH CENTRAL TO THE MID
TO UPPER 30S IN THE WATERTOWN/ORTONVILLE AREA. OTHERWISE...HIGHS
ON WEDNESDAY WILL LIKELY BE IN THE MORNING AS AN ARCTIC BOUNDARY
PUSHES IN DURING THE AFTERNOON WITH NORTH WINDS PICKING UP AND
TEMPERATURES FALLING ACROSS THE NORTH. EXPECT WINDS TO BECOME
BLUSTERY AT 15 TO 30 MPH WITH HIGHER GUSTS. THE OTHER ISSUE WILL
BE THE LIGHT SNOW DEVELOPING ALONG AND BEHIND THE SURFACE COLD
FRONT. MID LEVEL FRONTOGENESIS ALONG WITH SOME JET STREAK HELP
WILL BRING LIGHT SNOW TO NORTH CENTRAL SOUTH DAKOTA BY LATE
AFTERNOON. THE MODELS INDICATE LESSER AMOUNTS OF LIFT AND QPF AS
THIS REGION DESCENDS SOUTH ACROSS OUR CWA THROUGH WEDNESDAY NIGHT.
THUS...HAVE LIKELY CHANCES EARLY DIMINISHING THROUGH THE NIGHT.
SNOWFALL AMOUNTS SHOULD BE GENERALLY BELOW AN INCH BY THURSDAY
MORNING. ARCTIC AIR ENCOMPASSES THE ENTIRE CWA ON THURSDAY WITH
LESS WIND. MUCH BELOW NORMAL TEMPERATURES ARE EXPECTED ON
THURSDAY WITH HIGHS IN THE 20 TO 25 DEGREE RANGE ACROSS THE CWA.
THE MODELS THEN SHOW AN UPPER LEVEL LOW PRESSURE TROUGH AND THE
ASSOCIATED LIFT SWINGING OVER THE REGION THURSDAY AND THURSDAY
EVENING. WITH MUCH OF THE NORTHERN CWA UNDER LOW LEVEL DRY
AIR...EXPECT THE BEST CHANCES OF LIGHT SNOW WITH THIS SYSTEM TO
BE FROM PIR TO HURON TO ATY. EXPECT MORE CLOUD COVER AND LIGHT
SNOW TO SPREAD QUICKLY WEST TO EAST ON THURSDAY ACROSS MAINLY THE
SOUTHERN CWA. COULD HAVE SOME MORE SNOWFALL ACCUMULATIONS OF AN INCH
OR TWO. THE LIGHT SNOW WILL END QUICKLY THURSDAY NIGHT WITH
CLEARING SKIES IN BEHIND AND SINGLE DIGIT LOWS.
.LONG TERM...FRIDAY THROUGH TUESDAY
NORTHWEST FLOW ALOFT WILL DOMINATE THE LONG TERM PORTION OF THE
FORECAST. A SURFACE LOW PRESSURE SYSTEM PASSING ACROSS THE GREAT
LAKES REGION ON FRIDAY WILL ALLOW FOR BITTER ARCTIC COLD
TEMPERATURES TO FILTER INTO THE AREA BY FRIDAY NIGHT. BY 12Z
SATURDAY TEMPERATURES AT H85 RANGE IN THE MID TO UPPER TEENS BELOW
ZERO...WHICH IS APPROACHING TWO STANDARD DEVIATIONS BELOW NORMAL. LOW
TEMPERATURES SHOULD EASILY DROP TO THE SINGLE DIGITS ON EITHER
SIDE OF ZERO BY SATURDAY MORNING. THE SURFACE HIGH PRESSURE WILL
EXIT THE REGION ON SATURDAY NIGHT ALLOWING FOR WAA TO SPREAD INTO
THE CWA. TEMPERATURES THROUGH THE REST OF THE PERIOD WILL BE
AROUND NORMAL...DUE TO EXPECTED SNOW COVER. NO SIGNIFICANT
PRECIPITATION CHANCES ARE EXPECTED FOR THE PERIOD.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
PREVAILING VFR CONDITIONS ARE EXPECTED FOR ALL TERMINALS THROUGH
THE VALID TAF PERIOD. AN AREA OF LOW PRESSURE WILL PASS THROUGH THE
REGION DRY WITH ONLY HIGH CIRRUS EXPECTED. STRONG SOUTHERLY WINDS
AFFECTING THE TERMINALS OF KABR/KATY WILL DIMINISH BELOW 12 KNOTS LATER
THIS EVENING. WINDS SHOULD BE LIGHT AND VARIABLE THROUGH THE
MORNING HOURS ON WEDNESDAY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...MOHR
LONG TERM...SD
AVIATION...SD
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1128 AM CST TUE NOV 19 2013
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
AT 3 AM...A 1027 MB HIGH WAS CENTERED OVER NORTHERN ILLINOIS.
THE 19.00Z MODELS ARE IN GOOD AGREEMENT THAT THE HIGH WILL MOVE
NORTHEAST INTO LOWER MICHIGAN TODAY AND INTO NORTHERN NEW YORK
STATE BY WEDNESDAY MORNING. AS THIS OCCURS...SOUTH WINDS WILL
DEVELOP AND INCREASE INTO THE 10 TO 20 MPH RANGE THIS
MORNING...AND INTO THE 15 TO 25 MPH RANGE THIS AFTERNOON AND
CONTINUE INTO TONIGHT. AS USUAL...THE NAM IS MUCH HIGHER THAN THE
RUC AND GFS WITH ITS WIND GUSTS THIS AFTERNOON. THE NAM HAS WIND
GUSTS IN THE 30 TO 40 MPH RANGE. MEANWHILE THE RAP AND GFS HAVE
THEIR WIND GUSTS AROUND 30 MPH. SINCE THE NAM USUALLY IS A BIT TOO
HIGH...TRENDED THE WIND GUSTS TOWARD THE GFS AND RAP. BUFKIT
SOUNDINGS SHOW THAT THE MOISTURE WILL BE GRADUALLY INCREASING
ABOVE 500 MB TODAY. AS A RESULT WENT WITH INCREASING HIGH CLOUDS
THROUGHOUT THE DAY. THESE CLOUDS SHOULD ALLOW ENOUGH SUNSHINE FOR
TEMPERATURES TO APPROACH 50 DEGREES SOUTH OF INTERSTATE 94 AND
INTO THE MID AND UPPER 40S NORTH OF THIS INTERSTATE.
FROM LATE TONIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO SHOW
THAT THE 925 AND 850 MB MOISTURE TRANSPORT WILL INCREASE AHEAD OF
A SHORT WAVE TROUGH MOVING EAST OF THE PLAINS. THE BEST
SATURATION OCCURS ACROSS SOUTHWEST AND CENTRAL WISCONSIN ON
WEDNESDAY. AS A RESULT...WENT WITH THE HIGHEST RAIN CHANCES /40 TO
50 PERCENT/ FOR THIS AREA. RAINFALL AMOUNTS WILL BE LESS THAN A
TENTH OF AND INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 348 AM CST TUE NOV 19 2013
ON WEDNESDAY NIGHT...SUBSIDENCE QUICKLY DEVELOPS IN THE WAKE OF
THE TROUGH. AS THIS OCCURS...THE PRECIPITATION CHANCES QUICKLY
DECLINE DURING THE EVENING.
ON THURSDAY NIGHT...THE OPERATIONAL RUNS OF THE GFS...
ECMWF...AND NAM ARE SHOWING THAT A SOUTHERN AND NORTHERN STREAM
SYSTEM WILL PHASE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY. THE
AREA IS LOCATED IN THE RIGHT ENTRANCE REGION OF A 100 KNOT POLAR
JET AND THE LEFT EXIT REGION OF A 100 KNOT SUBTROPICAL JET. THESE
COUPLED JETS DRAMATICALLY INCREASE THE LIFT ACROSS THE AREA. DUE
TO THIS...THE MODELS ARE GENERATING MUCH MORE PRECIPITATION ACROSS
THE AREA THAN WHAT SHOWED UP IN PREVIOUS MODEL RUNS. DUE TO
THIS...THE PRECIPITATION CHANCES WERE RAISED UP TO 60 PERCENT.
HOWEVER THESE PRECIPITATION CHANCES ARE HIGHLY DEPENDENT UPON
WHETHER THIS JET COUPLING DOES INDEED OCCURS. 6 OF 12 GFS ENSEMBLE
MEMBERS SHOW THIS OCCURRING. MEANWHILE THE OTHER 6 SHOW THAT THESE
TWO SHORT WAVE TROUGHS WILL NOT PHASE AND THE AREA COULD
POTENTIALLY END UP BEING DRY. THIS IS 3 MORE MEMBERS THAN WHAT
SHOWED UP IN THE 18.18Z GFS ENSEMBLE. AS THESE WAVES MOVES
EAST...COLDER AIR WILL MOVE INTO THE REGION AS THE NIGHT
PROGRESSES AND THE PRECIPITATION WILL CHANGE OVER TO SLEET AND
SNOW. SNOW AMOUNTS COULD POTENTIALLY BE UP TO AN INCH NORTH OF AN
AUSTIN MINNESOTA TO NEILLSVILLE WISCONSIN LINE.
ON FRIDAY AND FRIDAY EVENING...COLDER AIR WILL SINK SOUTHWARD
ACROSS THE AREA. THIS WILL RESULT IN 950 TO 900 LAPSE RATES AROUND
OF 8 TO 9 C/KM. AS A RESULT...CONTINUED LIGHT SNOW CHANCES
THROUGHOUT MUCH OF THIS TIME PERIOD. ADDITIONAL SNOWFALL AMOUNTS
WILL BE LESS THAN A HALF INCH.
ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST REMAINS VERY
TRICKY. THIS IS DUE TO DIFFERING TIMES ON WHEN THE COLDEST AIR
WILL MOVE SOUTHWARD INTO THE FORECAST AREA. BOTH THE GFS AND GEM
HAS THIS AIR MASS ARRIVING MUCH SOONER...SO THEY HAS HIGH
TEMPERATURES REMAINING IN THE TEENS. MEANWHILE THE ECMWF IS A BIT
LATER AND THE HIGH TEMPERATURES CLIMB INTO THE LOWER AND MID 20S.
SINCE THERE WERE SOME DRAMATIC DIFFERENCES...JUST STAYED WITH THE
ALL BLEND MAXIMUM TEMPERATURES.
SATURDAY NIGHT...LOOKS VERY COLD ACROSS THE AREA WITH 925 MB
TEMPERATURES OF -14 TO -16C AND WINDS LIGHTENING THROUGH THE
NIGHT. LOW TEMPERATURES ON SUNDAY MORNING WILL LIKELY BE IN THE
SINGLE DIGITS ACROSS THE AREA. IF WE END UP GETTING MORE SNOW
THAN EXPECTED ON THURSDAY NIGHT...THESE TEMPERATURES MAY BE EVEN
COLDER.
LIKE SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS VERY TRICKY
BECAUSE THE GFS HAD WARM AIR ADVECTION KICKING A BIT FASTER THAN
THE ECMWF. AS A RESULT...THE GFS IS WARMER THAN THE ECMWF. SINCE
IT IS UNCERTAIN ON WHICH MODEL WILL VERIFY THE BEST...JUST STAYED
WITH THE ALL BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY)
ISSUED AT 1128 AM CST TUE NOV 19 2013
PRESSURE GRADIENT ACROSS THE UPPER MIDWEST WILL CONTINUE TO TIGHTEN
FOR THIS AFTERNOON/TONIGHT AS LOW PRESSURE DEEPENS INTO THE CENTRAL/
NORTHERN PLAINS. SOUTHEAST TO SOUTH GRADIENT WINDS ARE GOING TO
INCREASE INTO THE 10-20KT G20-30KT RANGE THRU THE AFTERNOON AND
CONTINUE TONIGHT INTO WED. WINDS WILL INCREASE ON TOP OF THE
NOCTURNAL INVERSION /AROUND 2K FT/ TONIGHT...TO 50-60KTS. CONTINUED
THE MENTION OF LLWS AT BOTH KRST/KLSE IN THE 03Z-15Z TIME-FRAME FOR
THE RAPID SPEED AND DIRECTIONAL CHANGE OF THE WIND IN THE SFC-2K FT
LAYER.
CLOUDS TODAY WILL BE SCT-BKN HIGH CLOUDS. SOME MID LEVEL MOISTURE
ARRIVES ON THE SOUTHERLY FLOW TONIGHT...WITH CLOUDS EXPECTED TO BE
IN THE 8K-10K FT RANGE. MOISTURE CONTINUES TO DEEPEN ON WED ALONG
WITH AN INCREASE OF LIFTING. MODEL CONSENSUS CONTINUE TO PRODUCE
SOME -RA IN/AROUND THE AREA BY LATE MORNING. INCLUDED VCSH AND CIGS
IN THE 6K-7K FT RANGE AFTER 15Z WED. ANY PRECIP LATE WED MORNING
LOOKS TO BE LIGHT ENOUGH TO HAVE MINIMAL IMPACT ON VSBYS. BIT MORE
WIDESPREAD -RA WED AFTERNOON MAY PRODUCE SOME MVFR VSBYS AFTER 18Z
WED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RRS