Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/07/12
AREA FORECAST DISCUSSION
NWS ALBANY NY
1026 PM EDT SAT OCT 6 2012
.SYNOPSIS...
MUCH COOLER AIR WILL CONTINUE TO STREAM INTO OUR REGION
OVERNIGHT AS WEAK HIGH PRESSURE CRESTS ACROSS THE REGION. LOW
PRESSURE WILL MOVE ALONG A FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING US MORE UNSETTLED WEATHER FOR SUNDAY AFTERNOON INTO
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE REGION ON MONDAY AND
BRING FAIR AND SEASONABLE WEATHER FOR THE FIRST HALF OF THE WORK
WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1026 PM EDT...A BAND OF LAKE EFFECT RAIN SHOWERS HAS
DEVELOPED OFF LAKE ONTARIO. WHILE THE MAJORITY OF THESE RAIN
SHOWERS ARE REMAINING CLOSE TO THE LAKESHORE AND ACROSS THE TUG
HILL...A FEW SHOWERS WILL MAKE IT INTO THE FAR WESTERN
ADIRONDACKS. AS THE FLOW SHIFTS...THIS BAND WILL GRADUALLY SHIFT
SOUTH...POSSIBLY AFFECTING PARTS OF THE WESTERN MOHAWK VALLEY BY
LATE TONIGHT. THIS IS BEING MODELED WELL BY THE LATEST HRRR AND
LOCAL WRF.
MEANWHILE...A SFC FRONTAL BOUNDARY CONTINUES TO MOVE TO THE SOUTH
AND EAST OF OUR AREA ACROSS EASTERN NEW ENGLAND AND DOWN OFF THE
MID ATLANTIC SEABOARD. WITH HIGH PRSSURE NOSING INTO THE AREA...THIS
SHOULD ALLOW FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES FOR THE
MAJORITY OF THE NIGHT. MID AND HIGH LEVEL CLOUDS WILL START TO
INCREASE TOWARDS DAYBREAK AS A WAVE OF LOW PRESSURE DEVELOPS ALONG
THE FRONTAL BOUNDARY TO OUR SOUTH.
MIN TEMPS OVERNIGHT WILL BE MUCH COOLER THAN RECENT NIGHTS DUE TO
THE COOLER AIR MASS MOVING INTO THE REGION. MIN TEMPS WILL RANGE
FROM JUST BELOW FREEZING ACROSS THE HIGHER PEAKS OF THE CENTRAL
ADIRONDACKS TO NEAR 40 IN THE HUDSON VALLEY AND NORTHWESTERN CT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
WHILE SFC CDFNT WILL STALL WELL OFFSHORE...THE COLD AIR REMAINS
SHALLOW AND THE H850 BAROCLINIC ZN/THERMAL RIBBON ONLY MOVES JUST
OFFSHORE. ALL THE MODEL SUITE (NAM/GFS/ECMWF/CMC) HAS COME INTO
AGREEMENT NOW SUN...WITH THE GFS JOINING THE OTHERS. STRONG 500HPA
SHORT WV EJECTS E FM OH VLY...ACROSS THE BAROCLINIC ZONE... AND
CLOUDS (DURING THE MORNING) AND WAA/OVERRUNNING RN (AFTN AND
EVENING) SPREAD QUICKLY NE BACK INTO THE REGION SUNDAY.
FORTUNATELY THIS SYSTEM IS FAST MOVING AND CYCLOGENISUS IS
MINIMAL...RAIN EXITS OVERNIGHT WITH MOST AREAS SUBJECT TO 6-12
HOURS OF RAIN SUN AFTN AND EVENING. WITH CLOUDS AND CAA TEMPS
WILL BE QUITE COOLER THAN THEY HAVE HAVE BEEN AND SVRL DEGREES
BLO NORMALS.
THERE WILL ALSO BE BRIEF PERIODS WHERE CONDS SUPPORT LK EFFECT
-SHRA AND SH-SN AT NIGHT OVER HIR TRRN TNGT AND SUN NIGHT...BUT
CHANGES IN FLOW AND WEAK FLOW WILL KEEP THIS CONFINED TO TUG HILL
AND LT.
AT 500HPA BROAD TROF OVER MID CONTINENT WILL RESULT IN SW FLOW
ACROSS FCA..AS SERIES OF SHORT WVS DIVE INTO TROF MOST ROTATING
WELL SOUTH OR NORTH OF REGION TILL WED. COLUMBUS DAY COOL HIGH
PRESSURE BUILDS FM OH VLY INTO NEW ENG. SOME WK LK RESPONSE MAY
LINGER INTO MONDAY MORNING IN N HERK/HAM COUNTIES...BUT WITH
SFC/LLVL FLOW BCMG LT AND SW...THIS WILL END.
SFC HI PRESSURE WILL REMAIN OVER THE RGN MON INTO WED MRNG. GEN
PC/CLEAR CONDS...SOME PATCHY CLOUDS IN MID LVL WAA N TIER..BUT A
FINE FALL PERIOD OF WX...NR NORMAL TEMPS...LT WINDS.
BY WED 500 TROF AXIS HAS SHIFTED E TO GRTLKS...AND SERIES OF SHORT
WVS DRIVES A CDFNT THRU FCA DURING LATE AFTN AND EVNG. THIS IS
ANOTHER ANNA TYPE EVENT LIKE TDY (SAT) WITH PD OF LT RAIN POST
FRONTAL.
MORNING LOWS MONDAY AND TUES UNDER CLEAR SKIES AND SFC HI W/12.5
PLUS HOURS OF NIGHT WILL HAVE NO PROBLEM FALLING INTO MID 20S TO
MID 30S. WOULD SUSPECT THIS TIME TOMORROW WE WILL BE CONSIDERING
FROST AND FREEZE FLAGS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
OTHER THAN MINOR TIMING DIFFERENCES ECMWF AND GFS IN REASONABLE
AGREEMENT. POPULATED WITH GMOS MAKING MINOR CHANGES. MID CONTINENT
500HPA TROF GRADUALLY SLIDES EASTWARD DURING THIS PERIOD AS A
500HPA RIDGE BUILDS IN ITS WAKE INTO THE GRTLKS TO END THE PERIOD.
THE PARADE OF SHORT WAVES CONTINUE TO MIGRATE AROUND THE BASE OF
THE TROF IN THE FAST FLOW. HIGH PRESSURE PASSES FM OH VLY TO MID
ATLC STATES THUR WITH GENERALLY FAIR CONDS. CLOUDS MAY INCR N AHEAD
OF NEXT SYSTEM THU AFTN AS PER GFS...BUT ECMWF KEEPS THIS MOISTURE
N OF RGN.
THE NEXT SHORT WV TO DRIVE A CDFNT THROUGH RGN IS FRI WITH WHAT
APPEARS TO BE YET ANOTHER ANNA TYPE CDFNT WITH PD OF LT RAIN IN ITS
WAKE. WITH TROF AXIS HAVING MOVED E TO OVER NY/NEW ENG FRI
NIGHT...CAA SURGE WILL BE STRONGER THE PVS FEW...WITH MINS IN 20S
TO LOW 30S MOST AREAS...AND WARMER READINGS CONFINED TO FAR SE.
WHERE THE GROWING SEASON IS STILL BARELY HANGING ON...IT SHOULD BE
OVER IN MOST AREAS BY THE WEEKEND. THE WEEKEND STARTS WITH ANOTHER
HIGH PRESSURE AREA IN THE FAST FLOW PASSING ACROSS RGN SAT. HWVR
THE PERIOD ENDS WITH 500HPA TROF EXITING...RIDGING IN ITS WAKE AND
WAA OVERSPREADING THE RGN FM THE WEST IN SPLIT FLOW.
TEMPS WILL REMAIN BLO NORMS FOR MOST OF THIS PERIOD. WHILE DRY AND
FAIR MUCH OF THE TIME A CDFNT WILL BRING A CHC OF -SHRA FRI AND
RAIN MAY OVERSPREAD THE REGION TO END THE WEEK.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
VFR FLYING CONDITIONS ARE EXPECTED THROUGH MUCH OF THE OVERNIGHT
HOURS WITH JUST FEW-SCT STRATOCU CLOUDS AROUND 4-6 KFT...MAINLY
DURING THE EVENING HOURS. SOME MID AND HIGH LEVEL CLOUDINESS WILL
MOVE INTO THE AREA TOWARDS DAYBREAK. LIGHT WESTERLY WINDS WILL BE IN
PLACE TONIGHT...AND WITH DEWPOINTS DROPPING DOWN INTO THE 30S...NO
RADIATIONAL FOG IS EXPECTED TO DEVELOP TONIGHT.
BKN-OVC MID LEVEL CLOUDINESS WILL BE IN PLACE FOR SUNDAY MORNING. SOME
RAIN WILL MOVE INTO THE REGION FROM SOUTH TO NORTH DURING THE
AFTN/EVE HOURS. THE MODELS ARE NOT IN AGREEMENT YET WITH THE EXACT
TIMING AND PLACEMENT OF THIS RAIN...BUT IT/S POSSIBLE THAT RAIN HOLDS
OFF FOR KALB/KGFL UNTIL 00Z MONDAY. KPSF/KPOU HAVE A BETTER CHC OF
SEEING SOME LIGHT RAIN DURING THE AFTN OR EVENING HOURS. FLYING
CONDITIONS COULD DROP TO MVFR WITHIN ANY RAINFALL. WESTERLY WINDS
WILL CONTINUE TO BE RATHER LIGHT.
OUTLOOK...
SUN NT...VFR/MVFR. CHC/LIKELY -SHRA SUN EVENING.
MON-TUE NT...VFR. NO SIG WX.
WED...VFR. CHC MVFR IN SHOWERS.
THU...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE EXPECTED. A WAVE OF LOW
PRESSURE WILL MOVE ALONG THE FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING MOST AREAS OVER A QUARTER INCH OF RAIN SUNDAY. HIGH
PRESSURE WILL BUILD INTO THE REGION ON MONDAY WITH FAIR AND COOL
WEATHER INTO WEDNESDAY WHEN ANOTHER FRONTAL SYSTEM WILL BRING A
PERIOD OF SHOWERS.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 7 DAYS.
AROUND A QUARTER INCH OF RAINFALL IS EXPECTED SUNDAY AFTERNOON/EVENING
AND WEDNESDAY AFTERNOON/EVENING. IN THE TUG HILL PLATEAU LAKE EFFECT
RAIN SHOWERS...AND OVER THE HIGHER TERRAIN AT NIGHT SNOW SHOWERS...WILL
PRODUCE UP TO AN INCH LIQUID TOTAL THIS WEEK. THESE AMOUNTS WILL
BE INSUFFICIENT TO PRODUCE MUCH RESPONSE IN RIVERS AND CREEKS THIS
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...FRUGIS/SNYDER
NEAR TERM...FRUGIS
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...FRUGIS
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
424 AM EDT FRI OCT 5 2012
.SYNOPSIS...
A FRONTAL BOUNDARY JUST OFF THE CAROLINA COAST THIS MORNING WILL
PUSH FARTHER OUT TO SEA TODAY. WEAK HIGH PRESSURE WILL BE OVER
THE FORECAST AREA TODAY THROUGH SATURDAY. A COLD FRONT WILL MOVE
INTO THE AREA SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE WEAK FRONTAL BOUNDARY HAS GONE AND HIGH PRESSURE HAS BEGUN TO
BUILD IN ACROSS THE FORECAST AREA THROUGH TODAY INTO TONIGHT.
SATELLITE LOOPS SHOWS THE BACK EDGE OF A CIRRUS SHIELD CONTINUES
TO RUN SW TO NE ACROSS THE WESTERN PORTION OF THE CWA. AT TIMES
THE CLOUDINESS HAS BEEN SCATTERED AND THIN...BUT CURRENTLY IS A
BIT THICKER AND MORE WIDESPREAD. AMOUNT/THICKNESS OF HIGH
CLOUDINESS TOWARD DAYBREAK WILL WEIGH ON THE AMOUNT OF
RADIATIONAL COOLING AND FOG FORMATION. PATCHY FOG...POSSIBLY
LOCALLY DENSE...IS POSSIBLE NEAR SUNRISE. WEAK HIGH PRESSURE WILL
DOMINATE TODAY AND TONIGHT. MODEL TIME SECTIONS SHOW A RELATIVELY
DRY AIRMASS ACROSS THE AREA THROUGH THE PERIOD. GUIDANCE AND
LOCAL NUMBERS VERY CLOSE FOR TEMPERATURES AND WILL STAY NEAR
CONSENSUS THROUGH THE PERIOD.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
BY SATURDAY INTO SATURDAY NIGHT...ALL OF THE MODELS INDICATE THAT
A FRONTAL BOUNDARY WILL BE APPROACHING THE AREA FROM THE WEST.
WITH FRONTAL BOUNDARY NEARLY PARALLEL TO MID/UPPER FLOW...LOOKS
LIKE THE FRONT WILL BE A SLOW MOVER INTO THE REGION. WILL LIKELY
HAVE TO WAIT FOR MORE VIGOROUS SHORTWAVE ENERGY EXPECTED TO MOVE
ACROSS THE MIDWEST/GREAT LAKES REGION BY SUNDAY FOR FRONT TO MOVE
INTO REGION. THE ECMWF IS STILL THE SLOWEST OF THE MODELS...BUT
GFS/NAM ALONG WITH ECMWF HAVE COME INTO BETTER AGREEMENT WITH THE
00Z MODEL RUN. GUIDANCE AND LOCAL NUMBERS SHOW WARM TEMPERATURES
FOR THE PERIOD WITH TEMPERATURES RUNNING NEARLY 10 DEGREES ABOVE
NORMAL. WILL STAY NEAR A CONSENSUS OF THE GUIDANCE AT THIS TIME
THROUGH THE PERIOD. HPC ANALYSIS INDICATES A COMPROMISE BETWEEN
THE SOLUTIONS MAY BE THE BEST TIMING FOR THE FRONT. WITH FRONT
APPROACHING BY SATURDAY NIGHT...HAVE INCLUDED A SLIGHT CHANCE/LOW
CHANCE OF SHOWERS ACROSS THE NORTH/NORTHWEST MIDLANDS. GUIDANCE
NUMBERS ONCE AGAIN VERY CONSISTENT AND WILL STAY NEAR CONSENSUS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
LATEST ECMWF/GFS CONTINUES TO SHOW A COLD FRONT THAT WILL BE
MOVING INTO THE AREA ON SUNDAY. A COMPROMISE BETWEEN THE FASTER
GFS AND SLOWER ECMWF WILL BE USED. CONTINUED WITH A CHANCE OF
SHOWERS SUNDAY/SUNDAY NIGHT. SREF ENSEMBLE GUIDANCE INDICATED THE
BEST CHANCE FOR RAIN TO BE SUNDAY AFTERNOON/EVENING. TEMPERATURES
WILL BE TRICKY ON SUNDAY BASED ON THE ARRIVAL OF THE FRONTAL
BOUNDARY...BUT EXPECT COOLER TEMPERATURES BY MONDAY. BEHIND THE
FRONT...COOL HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY
THROUGH TUESDAY NIGHT. TEMPERATURES SHOULD BEGIN TO GRADUALLY RISE
THROUGH THE REMAINDER OF THE LONG TERM PERIOD...BUT REMAIN BELOW
NORMAL. LOOKS LIKE THE AREA WILL SEE THE COOLEST TEMPERATURES OF
THE FALL PERIOD BY TUESDAY MORNING AS MANY AREAS WILL FALL INTO
THE MIDDLE TO UPPER 40S. TEMPERATURES WILL GRADUALLY MODERATE
WEDNESDAY INTO THURSDAY. ANOTHER DRY COLD FRONT APPROACHES FROM
THE WEST LATE WEDNESDAY INTO EARLY THURSDAY. EXPECT TEMPERATURES
TO REMAIN BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THIN HIGH CLOUDS CONTINUES ACROSS THE AREA BUT WITH LIGHT
BOUNDARY LAYER WINDS...HIGH NEAR-SURFACE RELATIVE HUMIDITY...FOG
DEVELOPING AT AREA TERMINALS. RADIATION FOG SCHEME ALONG WITH
LATEST HRRR AND LAMP SUGGEST WIDESPREAD MVFR THROUGH 09Z THEN
LIFR/IFR AROUND 12Z POSSIBLE ESPECIALLY AT AGS/OGB. VISIBILITY MAY
STAY UP AT DNL...CROSS OVER TEMPERATURE LOWER THAN OTHER TERMINAL
SITES AND STRATUS NOT FORECAST.
EXTENDED AVIATION OUTLOOK...REDUCED VISIBILITY IN EARLY MORNING FOG
POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
07/77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
105 AM EDT FRI OCT 5 2012
.SYNOPSIS...
A FRONTAL BOUNDARY JUST OFF THE CAROLINA COAST WILL FINALLY PUSH
FURTHER OUT TO SEA OVERNIGHT. WEAK HIGH PRESSURE WILL BE OVER THE
FORECAST AREA TODAY THROUGH SATURDAY. A COLD FRONT WILL MOVE INTO
THE AREA SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE WEAK FRONTAL BOUNDARY HAS GONE AND HIGH PRESSURE WILL BUILD
ACROSS THE FORECAST AREA OVERNIGHT. THE BACK EDGE OF A CIRRUS
SHIELD CONTINUES TO RUN SW TO NE ACROSS THE WESTERN PORTION OF THE
CWA. AT TIMES THE CLOUDINESS IS SCATTERED AND THIN.
AMOUNT/THICKNESS OF HIGH CLOUDINESS TOWARD MORNING WILL WEIGH ON
THE AMOUNT OF RADIATIONAL COOLING AND FOG FORMATION. PATCHY
FOG...POSSIBLY LOCALLY DENSE...IS POSSIBLE NEAR SUNRISE. WILL
CONTINUE TO MONITOR AREA OBS IN CASE A DENSE FOG ADVISORY MAY BE
NEEDED. LOW TEMPERATURES ARE EXPECTED TO BE IN THE MIDDLE TO
UPPER 50S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
THE SHORT TERM WILL BEGIN WITH WEAK HIGH PRESSURE ACROSS THE AREA
ON FRIDAY INTO FRIDAY NIGHT. BY SATURDAY INTO SATURDAY NIGHT...ALL
OF THE MODELS INDICATE THAT A FRONTAL BOUNDARY WILL BE APPROACHING
THE AREA FROM THE WEST. WITH FRONTAL BOUNDARY NEARLY PARALLEL TO
MID/UPPER FLOW...LOOKS LIKE THE FRONT WILL BE A SLOW MOVER INTO
THE REGION. WILL LIKELY HAVE TO WAIT FOR MORE VIGOROUS SHORTWAVE
ENERGY EXPECTED TO MOVE ACROSS THE MIDWEST/GREAT LAKES REGION BY
SUNDAY FOR FRONT TO MOVE INTO REGION. GUIDANCE AND LOCAL NUMBERS
SHOW WARM TEMPERATURES FOR THE PERIOD WITH TEMPERATURES RUNNING
NEARLY 10 DEGREES ABOVE NORMAL. WILL STAY NEAR A CONSENSUS OF THE
GUIDANCE AT THIS TIME THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
LATEST GFS CONTINUES TO SHOW AN APPROACHING COLD FRONT MOVING
INTO THE FORECAST AREA SUNDAY. CONTINUED WITH A CHANCE OF SHOWERS
SUNDAY/SUNDAY NIGHT. SREF ENSEMBLE GUIDANCE INDICATED THE BEST
CHANCE FOR RAIN TO BE SUNDAY AFTERNOON/NIGHT. TEMPERATURES WILL BE
TRICKY ON SUNDAY BASED ON THE ARRIVAL OF THE FRONTAL
BOUNDARY...BUT EXPECT COOLER TEMPERATURES BY MONDAY. TEMPERATURES
SHOULD BEGIN TO GRADUALLY RISE THROUGH THE REMAINDER OF THE LONG
TERM PERIOD...BUT REMAIN BELOW NORMAL. LOOKS LIKE THE AREA WILL
SEE THE COOLEST TEMPERATURES OF THE FALL PERIOD BY TUESDAY MORNING
AS MANY AREAS WILL FALL INTO THE UPPER 40S. TEMPERATURES WILL
GENERALLY MODERATE WEDNESDAY INTO THURSDAY. ANOTHER DRY COLD FRONT
APPROACHES FROM THE WEST LATE WEDNESDAY INTO EARLY THURSDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
THIN HIGH CLOUDS CONTINUES ACROSS THE AREA BUT WITH LIGHT
BOUNDARY LAYER WINDS...HIGH NEAR-SURFACE RELATIVE HUMIDITY...FOG
DEVELOPING AT AREA TERMINALS. RADIATION FOG SCHEME ALONG WITH
LATEST HRRR AND LAMP SUGGEST WIDESPREAD MVFR THROUGH 09Z THEN
LIFR/IFR AROUND 12Z POSSIBLE ESPECIALLY AT AGS/OGB. VISIBILITY MAY
STAY UP AT DNL...CROSS OVER TEMPERATURE LOWER THAN OTHER TERMINAL
SITES AND STRATUS NOT FORECAST.
EXTENDED AVIATION OUTLOOK...REDUCED VISIBILITY IN EARLY MORNING FOG
POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
07/77
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1011 AM CDT FRI OCT 5 2012
.DISCUSSION...
ISSUED 958 AM CDT FRI OCT 5 2012
BAND OF STEADIER RAIN HAS SHIFTED SOUTH AND WAS CENTERED ALONG THE
I-70 CORRIDOR LATE THIS MORNING...WITH SCATTERED SHOWERS TO THE
NORTHWEST. LATEST RAP MODEL KEEPS THE BULK OF THE RAIN SOUTH OF A
DANVILLE TO TAYLORVILLE LINE THE REMAINDER OF THE DAY...ALTHOUGH
THE HRRR AND NAM-12 SHOW SOME FILLING IN OF THE SCATTERED RAIN
ACROSS THE NORTHWEST CWA. TEMPERATURES ARE GOING NOWHERE FAST...
EXCEPT IN THE EXTREME SOUTHEAST WHERE THE RAIN HAS NOT STARTED
YET. HAVE LOWERED HIGH TEMPERATURES OVER MOST OF THE CWA...WITH
VALUES ONLY RISING A COUPLE MORE DEGREES ESPECIALLY IN THE RAINY
AREAS. UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 605 AM CDT FRI OCT 5 2012
COLD FRONT WHICH PUSHED ACRS OUR AREA YESTERDAY AFTERNOON AND
EVENING HAS SHIFTED WELL SOUTH OF THE TAF SITES EARLY THIS
MORNING. WEAK LOW PRESSURE ALONG THE BOUNDARY TO OUR SOUTHWEST
HAS PRODUCED BANDS OF SHOWERS AND ISOLD TSRA THRU EARLY THIS
MORNING ALONG WITH AREAS OF MVFR CIGS...ESPECIALLY WHERE THE
MORE CONCENTRATED AREA OF STEADIER RAINS HAS OCCURRED. WE EXPECT
SIMILAR CONDITIONS TO PREVAIL THRU MOST OF THE DAY WITH FORECAST
SOUNDINGS SUGGESTING OCNL MVFR OR LOWER CIGS IN RAIN WITH THE
POSSIBILITY FOR ISOLD CONVECTION AS WELL...ESPECIALLY AT SPI...
DEC...AND CMI. THE RAIN SHIELD WILL GRADUALLY BEGIN TO SHIFT
SOUTHEAST LATE TODAY AS THE SFC HIGH BUILDS SE INTO THE MIDWEST
BRINGING VFR CONDITIONS TO THE REMAINDER OF THE FORECAST AREA
AFTR 01Z. SFC WINDS WILL BE OUT OF THE N-NW AT AROUND 10 KTS
DURING THE DAY...AND THEN DROP TO BETWEEN 5 AND 10 KTS TONIGHT.
SMITH
&&
.PREV DISCUSSION...
ISSUED 214 AM CDT FRI OCT 5 2012
SHORT TERM...TODAY THROUGH SUNDAY
06Z/1AM SURFACE ANALYSIS SHOWS COLD FRONT JUST NORTH OF THE OHIO
RIVER...WITH CHILLY AIRMASS SETTLING SOUTHWARD INTO THE REGION.
WELL NORTH OF THE BOUNDARY...FRONTOGENETIC FORCING ALONG THE
MID-LEVEL BAROCLINIC ZONE IS TRIGGERING A BAND OF SHOWERS WITH
EMBEDDED THUNDERSTORMS FROM SOUTHEAST KANSAS NORTHEASTWARD INTO
CENTRAL ILLINOIS. AT THE CURRENT TIME...THE RAIN IS MAINLY
CENTERED ALONG A WATSEKA...TO LINCOLN...TO PITTSFIELD LINE. A
CLOSER LOOK AT FORCING SHOWS THE NAM 850MB FRONTOGENESIS FIELD
DEPICTING THE RAIN BAND QUITE NICELY...SO WILL FOLLOW THIS
PARAMETER CLOSELY FOR THE SHORT-TERM FORECAST. WITH REGION
REMAINING IN THE RIGHT ENTRANCE REGION OF A 300MB JET STREAK
ACROSS THE GREAT LAKES AND PRIMARY MID-LEVEL FORCING ONLY VERY
SLOWLY SINKING SOUTHWARD...THINK SHOWERS WILL BE WIDESPREAD ACROSS
THE CENTRAL AND SOUTHERN KILX CWA FOR MUCH OF THE DAY. BASED ON
LATEST RADAR LOOPS AND NAM FRONTOGENESIS...HAVE FOCUSED HIGHEST
POPS ALONG/SOUTH OF A RUSHVILLE TO BLOOMINGTON-NORMAL LINE THROUGH
MIDDAY. AFTER THAT...STRONGEST FORCING SHIFTS SOUTH TO ALONG THE
I-70 CORRIDOR DURING THE AFTERNOON. GIVEN STEEP LAPSE RATES ABOVE
700MB...WILL CONTINUE TO MENTION ISOLATED THUNDER THROUGHOUT THE
DAY AS WELL. RAIN TOTALS COULD EXCEED 1 INCH IN SOME LOCATIONS
ACROSS THE CENTRAL CWA...WITH AMOUNTS RAPIDLY DROPPING TO LESS
THAN ONE QUARTER OF AN INCH ACROSS THE FAR NORTH AROUND GALESBURG.
WITH COOL N/NE FLOW AND OFF-AND-ON SHOWERS...TEMPS WILL REMAIN
NEARLY STEADY IN THE UPPER 40S AND LOWER 50S.
AS SHORT-WAVE PUSHES EAST OF THE AREA...FRONT WILL FINALLY GET
SHOVED FURTHER SOUTH TONIGHT. MOST MODEL GUIDANCE IS SUGGESTING
SHOWERS PERSISTING ACROSS THE E/SE CWA THROUGH EVENING...BEFORE
GRADUALLY EXITING INTO INDIANA OVERNIGHT. WILL THEREFORE MAINTAIN
CHANCE POPS ALONG/EAST OF I-55 THROUGH MIDNIGHT...THEN JUST ACROSS
THE FAR SE AROUND LAWRENCEVILLE OVERNIGHT. FORECAST SOUNDINGS
INDICATE CLEARING SKIES FROM NORTHWEST TO SOUTHEAST ACROSS THE
AREA TONIGHT...WITH MOST LOCATIONS SEEING CLEAR SKIES BY DAWN
SATURDAY. GIVEN CLEARING SKIES AND CONTINUED CAA...OVERNIGHT LOWS
WILL DROP INTO THE MIDDLE TO UPPER 30S.
AFTER A COOL/DRY DAY ON SATURDAY...A VIGOROUS SHORT-WAVE WILL DIVE
OUT OF CANADA AND TRACK ACROSS THE AREA SATURDAY NIGHT. PREVIOUS
MODEL SOLUTIONS HAD SUGGESTED THAT THIS FEATURE COULD PULL THE
FRONT BACK NORTHWARD A BIT...POTENTIALLY BRINGING CLOUDS/SHOWERS
INTO THE SE CWA. THE 00Z NAM AND GFS BOTH KEEP ANY PRECIP WELL
SOUTH OF THE AREA...SO HAVE REMOVED PRECIP MENTION. MAIN STORY
WILL BE THE COLD WEATHER AND POTENTIAL FOR FREEZING TEMPS AND/OR
FROST. WITH SHORT-WAVE MOVING THROUGH THE AREA...PARTIAL CLOUD
COVER WILL LIKELY MITIGATE RADIATIONAL COOLING TO SOME EXTENT. IN
ADDITION...WITH SURFACE HIGH CENTERED OVER THE PLAINS...LIGHT N/NW
WINDS MAY ALSO PREVENT TEMPS FROM DROPPING AS LOW AS THEY WOULD
OTHERWISE. AS A RESULT...DO NOT THINK THERE WILL BE A WIDESPREAD
FROST OR FREEZE. INSTEAD...MOST LOCATIONS WILL DROP INTO THE
MIDDLE 30S...WITH A FEW FAVORED LOW-LYING/RURAL SPOTS DIPPING TO
NEAR OR SLIGHTLY BELOW FREEZING. BETTER OPPORTUNITY FOR
FROST/FREEZE MAY DEVELOP SUNDAY NIGHT ACROSS THE E/SE CWA AS RIDGE
AXIS SLIDES EASTWARD INTO THE OHIO RIVER VALLEY BY 12Z MON.
LIGHTEST WINDS WILL LIKELY OCCUR ALONG/SOUTHEAST OF A CHAMPAIGN TO
TAYLORVILLE LINE...SO THIS WILL BE THE AREA TO WATCH FOR POTENTIAL
WIDESPREAD FREEZE. FURTHER WEST...WEAK RETURN FLOW ON THE BACK
SIDE OF THE HIGH WILL KEEP TEMPS A COUPLE OF DEGREES WARMER.
LONG TERM...MONDAY THROUGH THURSDAY
MODERATING TEMPS ARE IN STORE FOR MONDAY AND TUESDAY...AS SOUTHERLY
FLOW BOOSTS HIGH TEMPS BACK INTO THE 60S. NEXT UPPER-WAVE AND
ASSOCIATED COLD FRONT IS SLATED TO APPROACH THE AREA LATE TUESDAY
INTO WEDNESDAY. 00Z GFS TRIES TO SPREAD SHOWERS INTO WEST-CENTRAL
ILLINOIS AS EARLY AS TUESDAY AFTERNOON...HOWEVER GIVEN DRY AIRMASS
IN PLACE...HAVE OPTED TO KEEP TUESDAY DRY. WILL INSTEAD FOCUS POPS
TUESDAY NIGHT...WHEN BOTH THE GFS AND ECMWF AGREE THAT FRONT WILL
PASS THROUGH. AFTER THAT...DRY WEATHER AND SLIGHTLY COOLER TEMPS
IN THE UPPER 50S/LOWER 60S WILL BE IN STORE FOR BOTH WEDNESDAY AND
THURSDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
644 AM CDT FRI OCT 5 2012
.UPDATE...
AS EXPECTED...THERE HAS BEEN A BRIEF LULL WITH PRECIP DROPPING
DOWN TO MAINLY SPRINKLES. RADARS THE PAST 30-45 MINUTES HAVE SHOWN
NEW DEVELOPMENT ACROSS NORTHERN MISSOURI AND INTO EXTREME SOUTHERN
IOWA. SOME OF THIS IS LIKELY MID LEVEL CLOUDS BASED ON APPEARANCE
AND CORRELATION WITH SATELLITE IMAGES. HOWEVER...SOME OF IT IS
LEGITIMATE SPRINKLES OR HIGH BASED SHRA ASSOCIATED WITH SOME
FORCING. SFC OBS INDICATE A WEAK TROF FROM ROUGHLY NORTHERN
WISCONSIN TO NEAR KOMA.
RAP TRENDS SHOW THIS FORCING CONTINUING INTO THE MORNING COMMUTE
BEFORE WEAKENING. THUS ANOTHER LULL MIGHT OCCUR FOR A FEW HOURS
LATE THIS MORNING BEFORE PRECIP RE-DEVELOPS AGAIN WITH THE ARRIVAL
OF THE SHORTWAVE. THE RAP AND WRF MODELS SUGGEST THE WEAK TROF
MOVING THROUGH IOWA MAY PROVIDE SOME ADDITIONAL FOCUS FOR DIURNAL
SHRA ACTIVITY OVER NOT QUITE THE SOUTHEAST HALF OF THE CWFA DURING
THE AFTERNOON HOURS. EXTRAPOLATION OF THE 12HR RAP POSITIONS
SUGGEST THE POSSIBILITY OF SOME SPRINKLES LINGERING PAST 00Z IN
THE FAR EAST/SOUTHEAST PARTS OF THE CWFA.
THE 06Z MODELS CONTINUE TO SHOW THE UPPER JET OVER THE AREA
TONIGHT SUGGESTING CS/CI MAY COME INTO PLAY WITH TEMPERATURES. THE
2 METER TEMPS FROM THE WRF LOOK TOO COLD. HOWEVER...IF CLOUD COVER
IS THIN ENOUGH THE DRY GROUND MAY NEGATE THE AFFECTS OF THE
CLOUDS. THUS THE POTENTIAL IS STILL THERE FOR POSSIBLE FREEZE
HEADLINES TONIGHT. ..08..
&&
.AVIATION...
VFR WX IS EXPECTED THROUGH 12Z/06 AS HIGH PRESSURE SLOWLY BUILDS
INTO THE MIDWEST. A DISTURBANCE MOVING THROUGH MAY PRODUCE SOME
SPRINKLES OR A LIGHT SHRA AT KMLI/KBRL. CLEARING SKIES AND
DECREASING WINDS AFT SUNSET MAY RESULT IN FROST FORMATION ON NON-
HANGARED ACFT. ..08..
&&
.PREV DISCUSSION... /ISSUED 324 AM CDT FRI OCT 5 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE COLD FRONT FROM LAKE HURON INTO TEXAS WITH
SFC WAVES IN SOUTHWEST MISSOURI AND NORTH TEXAS. A WEAK TROF RAN
FROM SOUTHERN LAKE MICHIGAN BACK TO THE KMCI AREA WITH ANOTHER FROM
LAKE SUPERIOR TO NEAR KHON. DEW POINTS ALONG AND SOUTH OF THE FRONT
WERE IN THE 50S AND 60S WITH 40S FROM LAKE MICHIGAN INTO KANSAS. DEW
POINTS IN THE 20S AND 30S WERE ACROSS MUCH OF THE PLAINS AND UPPER
MISSISSIPPI VALLEY.
SHORT TERM...TODAY AND TONIGHT...
RADAR RETURNS SHOW A WEAK AREA OF SPRINKLES/SHRA FROM SOUTH OF KIOWA
BACK THROUGH SOUTHERN IOWA. THIS PRECIPITATION APPEARS TO BE DUE TO
A MOISTURE AND THETA E GRADIENT PER RAP TRENDS AND THE OTHER MODELS.
THESE FEATURES WILL SLOWLY WEAKEN THE REMAINDER OF THE NIGHT INTO
THE MORNING COMMUTE. THE BETTER FORCING WITH THE MORE SUBSTANTIAL
SHRA ACTIVITY WILL CONTINUE ACROSS THE FAR SOUTHERN PARTS OF THE
CWFA THROUGH THE MORNING COMMUTE AS WELL. THERE MAY OR MAY NOT BE A
LULL IN THE PRECIPITATION DURING THE LATE MORNING HOURS WHILE THE
NEXT SHORTWAVE APPROACHES FROM THE PLAINS.
DURING THE AFTERNOON THIS SHORTWAVE MOVES ACROSS THE AREA. THERE IS
A COUPLED UPPER JET STRUCTURE WHICH WILL PROVIDE GENERAL SYNOPTIC
LIFT. THE SOUTH HALF OF THE CWFA WILL HAVE THE BETTER CHANCE AT
SEEING SHRA ACTIVITY.
TONIGHT...THERE MAY OR MAY NOT BE SOME LINGERING SPRINKLES IN THE
FAR EAST FOR A FEW HOURS. ALL MODELS SHOW A MOISTURE GRADIENT OVER
THE AREA WITH A DIFFUSE BUT WEAKENING THETA E GRADIENT. SO...HAVE
OPTED TO KEEP TONIGHT DRY.
THE LARGER CONCERN IS TEMPERATURES. ALL MODELS SHOW THE UPPER JET
OVER THE AREA WHICH COULD PROVIDE SOME CI/CS WHILE IN THE LOWER
LEVELS THE MODELS SUGGEST CLOUDS WITH THE INCREASING CYCLONIC FLOW
FROM THE SHORTWAVE DROPPING DOWN FROM THE NORTH. INTERESTINGLY...
THE MODELS ARE INDICATING SUBSIDENCE AND THUS POSSIBLE CLEAR SKIES.
CLOUD COVER WILL BE THE KEY TO HOW COLD IT GETS. IF THERE ARE CLOUDS
BUT THEY ARE THIN...THEN THE DRY GROUND MAY OFFSET THE CLOUDS AND
ALLOW TEMPERATURES TO DROP MORE THAN FCST. THE POTENTIAL DOES EXIST
FOR FREEZE HEADLINES FOR TONIGHT FROM ABOUT HWY 30 ON SOUTH. ..08..
LONG TERM...SATURDAY THROUGH THURSDAY...
THIS EXTENDED PERIOD WILL MAINLY FOCUS ON TEMPERATURES WITH
ACTIVE...YET MAINLY DRY NORTH TO NORTHWEST FLOW. SATURDAY SHOULD BE
QUITE COLD AND WITH A STRATOCUMULUS DECK SPREADING OVER THE REGION
EARLY IN THE DAY...WE MAY BE HARD PRESSED TO REACH 50 IN MANY
LOCATIONS. FOR NOW...IT IS MOST LIKELY TO BE CLOUDY EARLY ENOUGH IN
THE DAY TO HOLD THE NORTH 1/3 TO THE UPPER 40S FOR HIGHS...WHILE THE
SOUTH COULD REACH THE LOWER 50S. THIS MOST CERTAINLY APPEARS TO BE
THE COLDEST DAY IN THIS CURRENT STRETCH OF CHILLY WEATHER. SATURDAY
NIGHT...ALL MODELS DECREASE SKY COVER FROM WEST TO EAST DURING THE
LATE AFTERNOON/EARLY EVENING HOURS. COMBINED WITH LIGHT WINDS AND
LINGERING VERY COLD AIRMASS ALOFT...WE SHOULD DROP TO LOWS IN THE
20S OVER MOST OF THE CWA...WITH SOME LOWER TO MID 20S IN FAVORED
LOWER LYING AREAS. SHOULD TONIGHT NOT RESULT IN FREEZE
CONDITIONS...HEADLINES SHOULD BE REQUIRED FOR SATURDAY NIGHT.
SUNDAY BEGINS SEVERAL DAYS OF MODERATION TO MORE COMFORTABLE
WEATHER...WITH HIGHS REACHING THE MID 50S WITH PLENTY OF SUN...THEN
AFTER A COOL NIGHT IN THE 30S...MONDAY SHOULD SEE A RETURN TO THE
LOWER 60S. UNFORTUNATELY...THIS WARMTH WILL ARRIVE WITH STRONGER
WINDS...THUS SENSIBLE WEATHER WILL BE PRETTY BRISK OUT THERE.
TUESDAY...A PASSING WAVE IN NORTHWEST FLOW SHOULD KEEP US MILD
AGAIN...WITH A CHANCE FOR RAIN SHOWERS. MODELS INDICATE THAT GOOD
MOISTURE MAY BE NEAR OR JUST PASS SOUTH OF THE CWA. SO...WHILE
CHANCE ARE INCREASED FROM PRIOR FORECASTS...THE AMOUNTS MAY BE QUITE
LIGHT. AFTER TUESDAY...MORE DRY WEATHER WITH CANADIAN HIGH PRESSURE
IS IN STORE FOR WEDNESDAY AND THURSDAY. LOWS IN THE 30S AND HIGHS IN
THE 50S WED/60S THU ARE EXPECTED.
ERVIN
CLIMATE...
RECORD LOWS FOR OCTOBER 7...
MOLINE.........27 IN 1952
CEDAR RAPIDS...25 IN 2001
DUBUQUE........23 IN 2000
BURLINGTON.....26 IN 1952
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
324 AM CDT FRI OCT 5 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS THE COLD FRONT FROM LAKE HURON INTO TEXAS WITH
SFC WAVES IN SOUTHWEST MISSOURI AND NORTH TEXAS. A WEAK TROF RAN
FROM SOUTHERN LAKE MICHIGAN BACK TO THE KMCI AREA WITH ANOTHER FROM
LAKE SUPERIOR TO NEAR KHON. DEW POINTS ALONG AND SOUTH OF THE FRONT
WERE IN THE 50S AND 60S WITH 40S FROM LAKE MICHIGAN INTO KANSAS. DEW
POINTS IN THE 20S AND 30S WERE ACROSS MUCH OF THE PLAINS AND UPPER
MISSISSIPPI VALLEY.
&&
.SHORT TERM...TODAY AND TONIGHT...
RADAR RETURNS SHOW A WEAK AREA OF SPRINKLES/SHRA FROM SOUTH OF KIOWA
BACK THROUGH SOUTHERN IOWA. THIS PRECIPITATION APPEARS TO BE DUE TO
A MOISTURE AND THETA E GRADIENT PER RAP TRENDS AND THE OTHER MODELS.
THESE FEATURES WILL SLOWLY WEAKEN THE REMAINDER OF THE NIGHT INTO
THE MORNING COMMUTE. THE BETTER FORCING WITH THE MORE SUBSTANTIAL
SHRA ACTIVITY WILL CONTINUE ACROSS THE FAR SOUTHERN PARTS OF THE
CWFA THROUGH THE MORNING COMMUTE AS WELL. THERE MAY OR MAY NOT BE A
LULL IN THE PRECIPITATION DURING THE LATE MORNING HOURS WHILE THE
NEXT SHORTWAVE APPROACHES FROM THE PLAINS.
DURING THE AFTERNOON THIS SHORTWAVE MOVES ACROSS THE AREA. THERE IS
A COUPLED UPPER JET STRUCTURE WHICH WILL PROVIDE GENERAL SYNOPTIC
LIFT. THE SOUTH HALF OF THE CWFA WILL HAVE THE BETTER CHANCE AT
SEEING SHRA ACTIVITY.
TONIGHT...THERE MAY OR MAY NOT BE SOME LINGERING SPRINKLES IN THE
FAR EAST FOR A FEW HOURS. ALL MODELS SHOW A MOISTURE GRADIENT OVER
THE AREA WITH A DIFFUSE BUT WEAKENING THETA E GRADIENT. SO...HAVE
OPTED TO KEEP TONIGHT DRY.
THE LARGER CONCERN IS TEMPERATURES. ALL MODELS SHOW THE UPPER JET
OVER THE AREA WHICH COULD PROVIDE SOME CI/CS WHILE IN THE LOWER
LEVELS THE MODELS SUGGEST CLOUDS WITH THE INCREASING CYCLONIC FLOW
FROM THE SHORTWAVE DROPPING DOWN FROM THE NORTH. INTERESTINGLY...
THE MODELS ARE INDICATING SUBSIDENCE AND THUS POSSIBLE CLEAR SKIES.
CLOUD COVER WILL BE THE KEY TO HOW COLD IT GETS. IF THERE ARE CLOUDS
BUT THEY ARE THIN...THEN THE DRY GROUND MAY OFFSET THE CLOUDS AND
ALLOW TEMPERATURES TO DROP MORE THAN FCST. THE POTENTIAL DOES EXIST
FOR FREEZE HEADLINES FOR TONIGHT FROM ABOUT HWY 30 ON SOUTH. ..08..
.LONG TERM...SATURDAY THROUGH THURSDAY...
THIS EXTENDED PERIOD WILL MAINLY FOCUS ON TEMPERATURES WITH
ACTIVE...YET MAINLY DRY NORTH TO NORTHWEST FLOW. SATURDAY SHOULD BE
QUITE COLD AND WITH A STRATOCUMULUS DECK SPREADING OVER THE REGION
EARLY IN THE DAY...WE MAY BE HARD PRESSED TO REACH 50 IN MANY
LOCATIONS. FOR NOW...IT IS MOST LIKELY TO BE CLOUDY EARLY ENOUGH IN
THE DAY TO HOLD THE NORTH 1/3 TO THE UPPER 40S FOR HIGHS...WHILE THE
SOUTH COULD REACH THE LOWER 50S. THIS MOST CERTAINLY APPEARS TO BE
THE COLDEST DAY IN THIS CURRENT STRETCH OF CHILLY WEATHER. SATURDAY
NIGHT...ALL MODELS DECREASE SKY COVER FROM WEST TO EAST DURING THE
LATE AFTERNOON/EARLY EVENING HOURS. COMBINED WITH LIGHT WINDS AND
LINGERING VERY COLD AIRMASS ALOFT...WE SHOULD DROP TO LOWS IN THE
20S OVER MOST OF THE CWA...WITH SOME LOWER TO MID 20S IN FAVORED
LOWER LYING AREAS. SHOULD TONIGHT NOT RESULT IN FREEZE
CONDITIONS...HEADLINES SHOULD BE REQUIRED FOR SATURDAY NIGHT.
SUNDAY BEGINS SEVERAL DAYS OF MODERATION TO MORE COMFORTABLE
WEATHER...WITH HIGHS REACHING THE MID 50S WITH PLENTY OF SUN...THEN
AFTER A COOL NIGHT IN THE 30S...MONDAY SHOULD SEE A RETURN TO THE
LOWER 60S. UNFORTUNATELY...THIS WARMTH WILL ARRIVE WITH STRONGER
WINDS...THUS SENSIBLE WEATHER WILL BE PRETTY BRISK OUT THERE.
TUESDAY...A PASSING WAVE IN NORTHWEST FLOW SHOULD KEEP US MILD
AGAIN...WITH A CHANCE FOR RAIN SHOWERS. MODELS INDICATE THAT GOOD
MOISTURE MAY BE NEAR OR JUST PASS SOUTH OF THE CWA. SO...WHILE
CHANCE ARE INCREASED FROM PRIOR FORECASTS...THE AMOUNTS MAY BE QUITE
LIGHT. AFTER TUESDAY...MORE DRY WEATHER WITH CANADIAN HIGH PRESSURE
IS IN STORE FOR WEDNESDAY AND THURSDAY. LOWS IN THE 30S AND HIGHS IN
THE 50S WED/60S THU ARE EXPECTED.
ERVIN
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THE NEXT 24 HOURS WITH
SPOTTY SHOWERS FRONTAL CLOUD BAND HAS EXITED THE
CWA WHILE MID AND HIGH LEVEL CLOUDS FROM THE FIRST OF TWO
SHORTWAVE TROUGHS ENTER THE AREA. THE FIRST TROUGH WILL PASS THROUGH
EARLY TODAY AND THE SECOND THIS AFTERNOON...AND BOTH WILL PRODUCE
INTERMITTENT BOUTS OF LIGHT RAIN...PRIMARILY AT KBRL. OTHER TAF
SITES SHOULD REMAIN DRY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/ERVIN/08
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
621 PM CDT SAT OCT 6 2012
...UPDATED FOR THE 00Z TAF AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1256 PM CDT SAT OCT 6 2012
A DEEP LONGWAVE TROUGH ENCOMPASSED MUCH OF THE NORTHERN CONUS WITH
250MB CYCLONICALLY CURVED FLOW FROM THE GREAT BASIN THROUGH THE
GREAT PLAINS TO THE GREAT LAKES REGION. WITHIN THE LONGWAVE
TROUGH...A SHORTWAVE TROUGH WAS MOVING SOUTHEAST THROUGH WESTERN
NEBRASKA EARLY SATURDAY. 12Z UPPER AIR ANALYSIS REVEALED 700MB
FRONTOGENETIC ZONE EXTENDING FROM SOUTHERN WYOMING THROUGH EASTERN
COLORADO TO SOUTHWESTERN KANSAS WITH SATURATED OR NEAR SATURATED AIR
(700MB DEWPOINT DEPRESSIONS 0 OR 1 DEGC AT KRIW, KDNR, KDDC, KAMA,
KOUN). PRECIPITATION IN THE FORM OF RAIN AND SNOW EXTENDED ALL
ALONG THE STRONGEST ZONE OF MID LEVEL FRONTOGENESIS (THE STRONGEST
OF WHICH FROM NORTHEAST COLORADO TO NORTHWEST KANSAS TO FAR
SOUTHWEST NEBRASKA AS OF 17Z). LIGHTER BANDED PRECIPITATION WAS
FOUND ACROSS SOUTHWEST KANSAS WHERE 0.06 INCHES OF PRECIPITATION WAS
MEASURED SO FAR AT DODGE CITY (ALL IN THE FORM OF RAIN). SNOW WAS
REPORTED AS FAR SOUTHEAST AS DIGHTON...AND VERY BRIEFLY MIXED IN
WITH RAIN ACROSS THE NORTHWEST PORTIONS OF FORD COUNTY DURING ONE OF
THE HEAVIER BANDS EARLIER THIS MORNING. IT SEEMS THE SNOW LINE IS
MATCHING UP WELL WITH THE RAP ANALYZED 900 FT AGL FREEZING
LEVEL...WHICH EXTENDED FROM ROUGHLY GARDEN CITY TO DIGHTON (AND
POINTS NORTHWEST) AT 18Z.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 316 PM CDT SAT OCT 6 2012
THIS EVENING:
MID LEVEL FRONTOGENESIS (MAINLY CENTERED AROUND 700MB) WILL CONTINUE
TO DECREASE ACROSS WEST CENTRAL AND CENTRAL KANSAS AS THE MID LEVEL
SHORTWAVE TROUGH ACROSS SOUTHWEST NEBRASKA MOVES TOWARD SOUTHEAST
NEBRASKA. MID LEVEL DRYING FROM 800 TO 500MB (AND ABOVE THROUGH THE
UPPER TROPOSPHERE) WILL INCREASE AS SUBSIDENCE PREVAILS IN THE WAKE
OF THE PRIMARY SHORTWAVE TROUGH. MOISTURE AND ATTENDANT CLOUD IN THE
LOWER TROPOSPHERE (800-900MB) WILL ALSO BE DECREASING...HOWEVER RATE
OF DECREASE ACROSS SOUTHWEST AND WEST CENTRAL KANSAS IS STILL A
FAIRLY CHALLENGING FORECAST AS LOW STRATUS WILL BE DIFFICULT TO
DISLODGE AS REMNANT LOW LEVEL MOISTURE RECIRCULATES AROUND THE
ANTICYCLONE IN THIS LAYER. FEEL THAT CLOUDS IN THE 800-900MB LAYER
WILL SCATTER OUT SLOWLY FROM 00-06Z TONIGHT...AND MOST PROMINENT
FARTHER NORTHEAST AWAY FROM COLORADO.
OVERNIGHT:
A 1030MB SURFACE HIGH WILL BE MOVING SOUTH-SOUTHEAST WITH CENTER OF
SURFACE HIGH TAKING A TRACK FROM ROUGHLY WRAY, COLORADO TO DODGE
CITY TONIGHT. ALONG THE TRACK OF THE SURFACE HIGH SKY SHOULD CLEAR
OUT AFTER MIDNIGHT...AND TEMPERATURES WILL FALL INTO THE LOWER 30S
RATHER QUICKLY ONCE CLOUDS CLEAR. TEMPERATURES WILL MOST LIKELY
FALL TO 28 TO 30 DEGREES NORTH OF THE ARKANSAS RIVER BY 08 OR 09Z
AND REMAIN IN THIS RANGE FOR PROBABLY 4 OR 5 HOURS...WITH MINIMUM
AROUND SUNRISE OF 25 TO 27 DEGREES NORTH OF A DIGHTON TO NESS CITY
TO LACROSSE LINE. THIS IS MORE OR LESS A CONTINUATION OF THE
PREVIOUS FORECAST AND AM NOT MAKING ANY CHANGES TO THE GOING FREEZE
HEADLINES. WILL CONTINUE THE HARD FREEZE WARNING (28 DEGREES OR
BELOW FOR LOWS) NORTH OF A JOHNSON TO BUCKLIN TO STAFFORD LINE.
SOUTH OF THIS LINE TO THE OKLAHOMA BORDER WILL CONTINUE WITH THE
FREEZE WARNING FOR LOWS 29 TO 32 DEGREES. MUCH, IF NOT ALL, OF WEST
CENTRAL, SOUTHWEST, AND SOUTH CENTRAL KANSAS WILL SEE THE END TO THE
GROWING SEASON WITH THESE FORECAST TEMPERATURES TONIGHT.
SUNDAY:
A SECONDARY MINOR SHORTWAVE DISTURBANCE WILL BE ROTATING AROUND THE
MEAN TROUGH AXIS FROM SOUTHERN WYOMING TO NORTHEASTERN NEW
MEXICO...WHICH MAY BRING SOME MID LEVEL CLOUD BACK TO FAR SOUTHWEST
KANSAS BY DAYBREAK...HOWEVER NO OTHER SENSIBLE WEATHER IMPACTS ARE
EXPECTED WITH THIS FINAL SHORTWAVE TROUGH PASSAGE. THE SURFACE HIGH
WILL SHIFT INTO THE RED RIVER VALLEY BY MIDDAY SUNDAY...BUT OVERALL
PRESSURE GRADIENT WILL REMAIN RATHER WEAK WITH SOUTHWEST WINDS 8 TO
10 KNOTS EXPECTED. A WARMING OF THE LOWER TROPOSPHERE FROM DOWNSLOPE
MOMENTUM (850MB TEMPS INCREASING TO +5 TO +9C FROM EAST TO WEST)
WILL ALLOW SURFACE TEMPERATURES TO WARM UP WELL INTO THE MID TO
UPPER 50S...ESPECIALLY ACROSS CENTRAL AND SOUTH CENTRAL KANSAS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CDT SAT OCT 6 2012
MONDAY:
BROAD 500-250 HPA WNW FLOW IS EXPECTED MONDAY. THIS ORTHOGONAL FLOW
WRT THE ROCKIES WILL ALLOW FOR A LEE TROUGH TO FORM MONDAY FROM THE
SURFACE UP TO 850 HPA. AS A RESULT, A WEAK WARM AIR ADVECTION REGIME
IS EXPECTED WITH HIGHS MODERATING TO THE UPPER 60S DEG F TO AROUND
70 DEG F. A DRY FORECAST IS EXPECTED FOR THE BEGINNING OF THE WORK WEEK
AS THE REGION WILL BE FREE OF ANY SYNOPTIC DISTURBANCES AND ASSOCIATED
LIFT.
TUESDAY:
THE SYNOPTIC PATTERN CHANGES TUESDAY AS A BROAD POSITIVELY TILTED UPPER
LEVEL SHORTWAVE TROF EJECTS FROM THE CANADIAN PRAIRIES AND ACROSS THE
NORTHERN PLAINS. THIS UL FEATURE WILL USHER IN A PASSAGE OF A COLD FRONT.
HAVE USED 12Z ECMWF AS GUIDANCE FOR TEMPERATURES AS THE GFS CONTINUES
TO PERFORM POORLY (IN THIS CASE, USUALLY TOO AGGRESSIVE WITH THE FROPA).
HIGHS WILL VARY ACROSS THE REGION WITH LOW TO MID 60S DEG F ACROSS THE
INTERSTATE 70 CORRIDOR TO MID 70S DEG F ACROSS EXTREME SOUTHWEST KANSAS.
THIS FRONT WILL BE DRY WITH A LACK OF BOUNDARY LAYER MOISTURE IN PLACE.
WILL KEEP POPS NEAR ZERO PERCENT. SFC WINDS DON`T LOOK PARTICULARLY
STRONG WITH THIS HIGH AS 850 HPA WINDS ARE ONLY FORECAST TO BE IN THE
20-25 KT RANGE.
WEDNESDAY:
A RIDGE OF HIGH PRESSURE WILL TRANSLATE ACROSS THE SUNFLOWER STATE WEDNESDAY
IN THE WAKE OF THE DENSITY GRADIENT. HIGHS IN THE 60S DEG F ARE EXPECTED
AS FAIRLY COOL 850 HPA TEMPERATURES (9-13 DEG C) ARE FORECAST IN ASSOCIATION
WITH THE AFOREMENTIONED COOL HIGH PRESSURE CENTER MOVING ACROSS THE
STATE. WILL ALSO RUN WITH THE ALLBLEND POPS (AROUND 3 PERCENT) FOR
THE MIDDLE PORTION OF THE WORK WEEK.
THURSDAY AND BEYOND:
THE FORECAST BECOMES MORE INTERESTING TOWARDS THE END OF THE WORK WEEK
ALTHOUGH SYNOPTIC AND MESOSCALE DETAILS ARE VERY UNCERTAIN AT THIS POINT.
FOR EXAMPLE, YESTERDAYS ECMWF RUN HAD THE WARM SECTOR (HIGHER THETA-E
AIR) SPREADING NORTHWARD IN ASSOCIATION WITH THE PASSAGE OF A WARM FRONT
FRIDAY. TODAY`S 12Z ECMWF RUN KEEPS THAT BOUNDARY SOUTH OF THE REGION
FRIDAY. THIS BOUNDARY PLACEMENT WILL HAVE SIGNIFICANT IMPACTS IN TERMS
OF SENSIBLE WEATHER AS A WAA PATTERN/THETA-E ADVECTION ALONG SAID FRONT
COULD LEAD TO THE DEVELOPMENT OF CONVECTION ACROSS THE PLAINS. FOR NOW
WILL GO WITH A BLEND OF THE ALLBLEND POPS ALTHOUGH WILL SMOOTH POPS
TOWARDS A BIAS TO THE ECMWF. THE GFS WAS GENERALLY DISREGARDED AS THE
MODEL CONTINUES TO BE VERY PROGRESSIVE WITH UL FEATURES THAT WILL PROBABLY
SLOW DOWN WITH TIME. IT SHOULD BE NOTED THAT MUCH UNCERTAINTY EXISTS
WITH THE EVOLUTION OF THE DESERT SOUTHWEST UL LOW THAT WILL BE THE IMPETUS
FOR CONVECTION. IT ALSO SHOULD BE NOTED THAT THERE IS THE POSSIBILITY
OF SEVERE CONVECTION, PARTICULARLY FRIDAY AND SATURDAY. WARM SECTOR
PLACEMENT AND ASSOCIATED REDISTRIBUTION OF ENERGY PER UNIT MASS (I.E.
CAPE) IS UNCERTAIN. REGARDLESS OF WHEREVER THE WARM SECTOR WILL BE,
THE ECMWF SHOWS SIGNIFICANT BOUNDARY LAYER MOISTURE WORKING ITS WAY
NORTH FROM THE GULF OF MEXICO. KINEMATIC PROFILES ALSO STRENGTHEN WITH
TIME AS THE UL LOW MOVES CLOSER TO KANSAS WITH 250 HPA FLOW INCREASING
TO 100 KT, 500 HPA FLOW INCREASING TO 60 KT, AND FAIRLY STRONG AND VEERING
FLOW FROM THE SFC THROUGH 700 HPA. SEVERE WEATHER EPISODES IN OCTOBER
ARE NOT UNUSUAL FOR THE PLAINS. IN FACT, THERE WERE TORNADOES LAST OCTOBER
ACROSS THE REGION LAST YEAR. IT IS TOO EARLY TO DETERMINE STORM MODE
AND PLACEMENT AT THIS TIME BUT IT IS SOMETHING TO WATCH FOR IN FUTURE
MODEL RUNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 607 PM CDT SAT OCT 6 2012
AS SURFACE HIGH PRESSURE STRENGTHEN AND THE LOWER LEVEL MOISTURE
ADVECTS TO THE EAST, LOW STRATUS CIGS WILL DEVELOP INTO SCATTERED
CLOUDS BETWEEN 04 AND 06Z. WINDS WILL BECOME LIGHT AND VARIABLE
ABOUT THE SAME TIME. SOME MID LEVEL CLOUDS WILL MOVE INTO
SOUTHWEST KANSAS AFTER SAT AT 15Z, MAINLY DUE TO AN UPPER LEVEL
WAVE CROSSING FROM FROM COLORADO TO MISSOURI. WINDS ON SATURDAY
SHOULD PICK UP FROM THE SOUTH TO SOUTHWEST AT 10 TO 13 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 28 57 34 69 / 10 10 0 0
GCK 28 57 32 69 / 10 10 0 0
EHA 30 54 35 67 / 10 10 0 0
LBL 30 54 34 67 / 10 10 0 0
HYS 26 58 34 70 / 20 0 0 0
P28 29 56 35 69 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING FROM 1 AM CDT /MIDNIGHT MDT/ TO 9 AM CDT /8
AM MDT/ SUNDAY FOR KSZ030-031-043>046-061>066-074>079.
FREEZE WARNING FROM 1 AM TO 9 AM CDT SUNDAY FOR KSZ080-081-
084>090.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...SUGDEN
AVIATION...BURKE
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1027 PM EDT SAT OCT 06 2012
.Forecast Update...
Updated at 1027 PM EDT Sat Oct 6 2012
HRRR and RAP show KY staying dry tonight and this is supported by
regional radars and upstream obs. Decent band of reflectivities
passed over Logan and Simpson Counties within the last hour but
neither Mesonet station reported measurable rainfall. So, will back
off on PoPs a bit. Will still keep some low chances going far south
though in case any activity can blossom ahead of the approaching
upper trof or slip over the border from Tennessee.
&&
.Short Term (Today through Sunday)...
Issued at 300 PM EDT Sat Oct 6 2012
A persistent Rex Block at 500mb just off the Pacific Coast has
allowed
northerly flow to develop downstream across the Upper Midwest. A
chilly Canadian airmass has already penetrated practically as far
south as the Texas Gulf coast, and remains banked up against higher
terrain in New Mexico and Colorado.
Clouds will increase this evening as one of several flat
disturbances embedded within a broader 500mb cyclonic gyre scoots
across Missouri. Both the GFS and NAM models take this feature
across Tennessee and southern Kentucky during the overnight hours. A
light chilly rain may develop across our southern counties later
this evening, ending around dawn across our southern Bluegrass or
Lake Cumberland Region. Precipitation totals will stay light,
totaling around two tenths of an inch or less. Feel that Louisville
and possible Lexington will stay north of this potential strip of
precipitation. Expect a cloudy cool night with lows ranging from
just under 40 to the lower 40s.
Skies will clear pretty readily Sunday morning as this 500mb wave
passes and subsidence overspreads the area. Canadian high pressure
will settle over the southern plains by Sunday afternoon, with an
axis extending east across the Commonwealth. Light north winds
Sunday afternoon will become calm overnight through Monday.
Early Monday will provide our best chance for widespread frost and
even a chance of a light freeze across some of our colder rural
locations. Frost chances will depend on how clear we become by early
Monday. High clouds associated with a disturbance over Tennessee may
spread as far north as Interstate 64 early Monday. This may, if
thick enough, limit frost chances across our south. Agricultural
interests should however, plan on at least some frost across
southern Indiana and north central Kentucky. Some lows early Monday
may reach or approach 32 for a few hours.
.Long Term (Monday - Saturday)...
Issued at 300 PM EDT Sat Oct 6 2012
High pressure will be over the region Monday morning at the same
time a vortmax is crossing the region aloft. Clouds associated with
this shortwave will be over or just east of the eastern forecast
area at the start of this period. During the day Monday and
continuing into Tuesday, the high will become centered over New
England.
Tuesday night, a cold front will move into the Midwest. Moisture
ahead of this front is not that impressive but will be enough to
warrant a chance for rain to come through the forecast area. After
that front, another cold shot of Canadian air will build into the
region, with high pressure becoming centered over the region
Thursday morning. Deterministic and Ensemble models support this
scenario, meaning another chilly morning with more frost possible
Thursday morning.
Progressive flow aloft, with persistent troughiness across eastern
Canada, will bring another moisture-starved front through the region
Friday morning. The high behind this front looks to move more to our
north. This may allow for a quicker return of moisture into the area
for next weekend. 00Z ECMWF and latest GFS/DGEX all indicate some
weak warm frontal-type forcing across the region Saturday, with the
latter two bringing rain into the region. For now will lean toward
the ECMWF solution, which keeps the best rain chances to our
northwest.
&&
.Aviation (00Z TAF Issuance)...
Issued at 711 PM EDT Sat Oct 6 2012
An upper shortwave trof exiting the Plains will spread overcast
skies across Kentucky tonight. The clouds should stay well VFR
other than maybe some scattered 015-030 clouds especially at BWG.
The GFS is advertising widespread rain tonight all the way up to the
Ohio River. However, the GFS often paints virga as QPF. Looking at
several mesoscale models it does appear that radar echoes in the
north will be virga as dry surface high pressure noses in beneath
the upper wave. A check of upstream obs shows mostly AC ceilings
with just a stray sprinkle or two. BWG stands the only real chance
of rain tonight, and even there it will be quite light.
As the upper trof axis crosses the area Sunday morning the clouds
will scatter out and provide us with a very nice day.
Winds will be much lighter tonight than they were last night, still
out of the northwest. During the day Sunday, especially by
afternoon, they should become more WNW and increase a little to
around 8 kts.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......JSD
Long Term........RJS
Aviation.........13
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
643 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A CANADIAN COLD FRONT...WILL MOVE SOUTHEASTWARD THROUGH THE UPPER
OHIO VALLEY TONIGHT...AND BRING SHOWERS AND MUCH COOLER
TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
MINOR ADJUSTMENTS TO EVE UPDATE. SOME TIMING CHANGES TO OVERNIGHT
POPS AND ADJUSTED TEMPS CLOSER TO LATEST GUIDANCE.
PREVIOUS DISCUSSION...
JUDGING FROM BLEND OF RECENT SURFACE...RADAR AND SATELLITE
DATA...COUPLED WITH RECENT WRF-NMM AND RAP MODEL OUTPUT...CONTINUE
TO EXPECT THE MAIN ADIABATIC COLD FRONTAL BAND OF SHOWERS TO MOVE
SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY LATE TONIGHT INTO
SATURDAY MORNING.
HOWEVER...MODEL OUTPUT CONTINUES TO SUGGEST THERE CAN BE A THIN
BAND OF SCATTERED PREFRONTAL SHOWERS DEVELOPING ACROSS THE UPPER
OHIO VALLEY THIS EVENING. EVEN IF SO PRECIPITATION AMOUNTS WOULD
BE LIGHT. CONCUR WITH HPC QPF THAT RAIN AMOUNTS LATE TONIGHT INTO
SATURDAY MORNING CAN BE UP TO 0.25 INCHES.
FORECASTED TEMPERATURES...PER RECENT GFS AND NAM MOS...TO BECOME
NOTICEABLY COLDER WITH LOWS TONIGHT DOWN TO NEAR NORMAL WITH HIGHS
SATURDAY ABOUT 10 DEGREES COLDER THAN NORMAL.
DUE TO SHALLOW BUT VIGOROUS VERTICAL MIXING IN WAKE OF THE COLD
FRONTAL PASSAGE...WIND MAY GUST UP TO 20 TO 25 MPH THROUGH DAYTIME
SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MORE RECENT SREF MODEL OUTPUT SHOW THE ENSUING LOW PRESSURE WAVE
ALONG THE EXITED COLD FRONT WILL AT MOST ONLY MAINLY AFFECT WV-MD
MOUNTAINS SATURDAY NIGHT AND SUNDAY. HOWEVER...THE COLD UPPER
TROUGH WILL MAINTAIN CLOUDY SKIES INTO MONDAY...AND MAY PROMOTE
SCATTERED INSTABILITY SHOWERS LATE SUNDAY ACROSS MAINLY WESTERN
PENNSYLVANIA.
DUE TO THE COLDNESS OF THE SURFACE LAYER...ITS POSSIBLE HIGHER
ELEVATIONS MAY SEE A CHANGE TO LIGHT SNOW SHOWERS AT TIMES...BUT
THE GROUND WILL REMAIN TOO WARM FOR ANY IMPACT.
FORECASTED SPECIFIC TEMPERATURES USING BLEND OF GFS NAM AND ECMWF
MOS...THAT SHOWED VALUES GENERALLY 7 TO 10 DEGREES COLDER THAN
NORMAL...WITH HIGHS SUNDAY PERHAPS 10 TO 13 DEGREES COLDER THAN
NORMAL.
ALTHOUGH MOST LOW TEMPERATURES SUNDAY NIGHT WILL BE IN THE LOWER
TO MID 30S...FROST AND FREEZE PROSPECTS WILL DEPEND REMAINING
EXTENT OF CLOUD COVER AND WIND...SO HELD OFF ON ANY CORRESPONDING
ISSUANCES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE EXTENDED PERIOD BEGINS WITH HIGH PRESSURE RIDGE ALONG MUCH OF
THE EASTERN UNITED STATES...WHICH SHOULD PERSIST FROM MONDAY NIGHT
INTO TUESDAY NIGHT.
LOW PRESSURE IS THEN EXPECTED TO MOVE EAST FROM LAKE
HURON...SKIRTING THE U.S.-CANADA BORDER. THE LOW SHOULD BRING A
COLD FRONT THROUGH THE REGION ON WEDNESDAY. FOR NOW HAVE STUCK
WITH CHANCE POPS DURING THE DAYTIME. THE FRONT SHOULD DROP
TEMPERATURES ABOUT 5 DEGREES FROM THE PREVIOUS DAYS READING.
HIGH PRESSURE WILL THEN RETURN WEDNESDAY NIGHT AND REMAIN ACROSS
THE SOUTHEASTERN UNITED STATES THURSDAY. ANOTHER CANADIAN LOW
SHOULD SWEEP A SECOND COLD FRONT THROUGH THURSDAY NIGHT INTO
FRIDAY. THIS SHOULD BRING AT LEAST A SLIGHT CHANCE OF SHOWERS
DURING THAT TIME PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
EXPECT BROKEN LOW VFR CIGS IN DIURNAL CUMULUS THIS AFTERNOON...WITH
SW GUSTS UP TO 15-20 KTS POSSIBLE.
BY SUNSET STRATUS DECK SHOULD BE MOVING IN FROM THE WEST. THE
STRATUS SHOULD PROVIDE VFR CEILINGS...EVENTUALLY DROPPING TO MVFR
CIGS AS RAIN MOVES IN AROUND MIDNIGHT. DROPPED CIGS DOWN TO 1KFT
AT FKL AND DUJ...BUT NOT ENOUGH CONFIDENCE TO GO IFR AT THIS
POINT. WITH RAIN EXPECTED TO FALL PRIMARILY BEHIND THE COLD
FRONT...EXPECT WIND SHIFT BEFORE RAIN BEGINS TO FALL. WINDS WILL
SHIFT TO THE WEST AND INCREASE AS WIDESPREAD RAIN ENDS SATURDAY
MORNING...WITH CIGS REMAINING AT A VFR LEVEL.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
WIDESPREAD LOW VFR/HIGH MVFR CIGS CAN BE EXPECTED ALONG WITH
SCATTERED SHOWERS SATURDAY NIGHT INTO SUNDAY. VFR CAN BE EXPECTED
SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A COLD FRONT BRINGS
POSSIBLE RESTRICTIONS IN SHOWERS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
350 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A CANADIAN COLD FRONT...WILL MOVE SOUTHEASTWARD THROUGH THE UPPER
OHIO VALLEY TONIGHT...AND BRING SHOWERS AND MUCH COOLER
TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
JUDGING FROM BLEND OF RECENT SURFACE...RADAR AND SATELLITE
DATA...COUPLED WITH RECENT WRF-NMM AND RAP MODEL OUTPUT...CONTINUE
TO EXPECT THE MAIN ADIABATIC COLD FRONTAL BAND OF SHOWERS TO MOVE
SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY LATE TONIGHT INTO
SATURDAY MORNING.
HOWEVER...MODEL OUTPUT CONTINUES TO SUGGEST THERE CAN BE A THIN
BAND OF SCATTERED PREFRONTAL SHOWERS DEVELOPING ACROSS THE UPPER
OHIO VALLEY THIS EVENING. EVEN IF SO PRECIPITATION AMOUNTS WOULD
BE LIGHT. CONCUR WITH HPC QPF THAT RAIN AMOUNTS LATE TONIGHT INTO
SATURDAY MORNING CAN BE UP TO 0.25 INCHES.
FORECASTED TEMPERATURES...PER RECENT GFS AND NAM MOS...TO BECOME
NOTICEABLY COLDER WITH LOWS TONIGHT DOWN TO NEAR NORMAL WITH HIGHS
SATURDAY ABOUT 10 DEGREES COLDER THAN NORMAL.
DUE TO SHALLOW BUT VIGOROUS VERTICAL MIXING IN WAKE OF THE COLD
FRONTAL PASSAGE...WIND MAY GUST UP TO 20 TO 25 MPH THROUGH DAYTIME
SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MORE RECENT SREF MODEL OUTPUT SHOW THE ENSUING LOW PRESSURE WAVE
ALONG THE EXITED COLD FRONT WILL AT MOST ONLY MAINLY AFFECT WV-MD
MOUNTAINS SATURDAY NIGHT AND SUNDAY. HOWEVER...THE COLD UPPER
TROUGH WILL MAINTAIN CLOUDY SKIES INTO MONDAY...AND MAY PROMOTE
SCATTERED INSTABILITY SHOWERS LATE SUNDAY ACROSS MAINLY WESTERN
PENNSYLVANIA.
DUE TO THE COLDNESS OF THE SURFACE LAYER...ITS POSSIBLE HIGHER
ELEVATIONS MAY SEE A CHANGE TO LIGHT SNOW SHOWERS AT TIMES...BUT
THE GROUND WILL REMAIN TOO WARM FOR ANY IMPACT.
FORECASTED SPECIFIC TEMPERATURES USING BLEND OF GFS NAM AND ECMWF
MOS...THAT SHOWED VALUES GENERALLY 7 TO 10 DEGREES COLDER THAN
NORMAL...WITH HIGHS SUNDAY PERHAPS 10 TO 13 DEGREES COLDER THAN
NORMAL.
ALTHOUGH MOST LOW TEMPERATURES SUNDAY NIGHT WILL BE IN THE LOWER
TO MID 30S...FROST AND FREEZE PROSPECTS WILL DEPEND REMAINING
EXTENT OF CLOUD COVER AND WIND...SO HELD OFF ON ANY CORRESPONDING
ISSUANCES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE EXTENDED PERIOD BEGINS WITH HIGH PRESSURE RIDGE ALONG MUCH OF
THE EASTERN UNITED STATES...WHICH SHOULD PERSIST FROM MONDAY NIGHT
INTO TUESDAY NIGHT.
LOW PRESSURE IS THEN EXPECTED TO MOVE EAST FROM LAKE
HURON...SKIRTING THE U.S.-CANADA BORDER. THE LOW SHOULD BRING A
COLD FRONT THROUGH THE REGION ON WEDNESDAY. FOR NOW HAVE STUCK
WITH CHANCE POPS DURING THE DAYTIME. THE FRONT SHOULD DROP
TEMPERATURES ABOUT 5 DEGREES FROM THE PREVIOUS DAYS READING.
HIGH PRESSURE WILL THEN RETURN WEDNESDAY NIGHT AND REMAIN ACROSS
THE SOUTHEASTERN UNITED STATES THURSDAY. ANOTHER CANADIAN LOW
SHOULD SWEEP A SECOND COLD FRONT THROUGH THURSDAY NIGHT INTO
FRIDAY. THIS SHOULD BRING AT LEAST A SLIGHT CHANCE OF SHOWERS
DURING THAT TIME PERIOD.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
EXPECT BROKEN LOW VFR CIGS IN DIURNAL CUMULUS THIS AFTERNOON...WITH
SW GUSTS UP TO 15-20 KTS POSSIBLE.
BY SUNSET STRATUS DECK SHOULD BE MOVING IN FROM THE WEST. THE
STRATUS SHOULD PROVIDE VFR CEILINGS...EVENTUALLY DROPPING TO MVFR
CIGS AS RAIN MOVES IN AROUND MIDNIGHT. DROPPED CIGS DOWN TO 1KFT
AT FKL AND DUJ...BUT NOT ENOUGH CONFIDENCE TO GO IFR AT THIS
POINT. WITH RAIN EXPECTED TO FALL PRIMARILY BEHIND THE COLD
FRONT...EXPECT WIND SHIFT BEFORE RAIN BEGINS TO FALL. WINDS WILL
SHIFT TO THE WEST AND INCREASE AS WIDESPREAD RAIN ENDS SATURDAY
MORNING...WITH CIGS REMAINING AT A VFR LEVEL.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
WIDESPREAD LOW VFR/HIGH MVFR CIGS CAN BE EXPECTED ALONG WITH
SCATTERED SHOWERS SATURDAY NIGHT INTO SUNDAY. VFR CAN BE EXPECTED
SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A COLD FRONT BRINGS
POSSIBLE RESTRICTIONS IN SHOWERS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1205 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A CANADIAN COLD FRONT...WILL MOVE SOUTHEASTWARD THROUGH THE UPPER
OHIO VALLEY TONIGHT...AND BRING SHOWERS AND MUCH COOLER
TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
JUDGING FROM BLEND OF RECENT RADAR AND SATELLITE DATA...EXPECT
SKIES TO REMAIN FAIRLY SUNNY THIS AFTERNOON. SURFACE DATA SHOWS
TEMPERATURES CORRESPONDINGLY CLIMBING...SO HAVE CONTINUED FORECAST
OF HIGHS THIS AFTERNOON GENERALLY 10 DEGREES WARMER THAN
NORMAL...WHICH CONCURS WITH RECENT GFS LAMP AND HRRR MODEL OUTPUT.
PER BLEND OF RECENT HIGH-RESOLUTION MODEL OUTPUT...PARTICULARLY
WRF-NMM AND WRF-ARW...SHOW COLD ANAFRONTAL BAND OF SHOWERS PASSING
SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY...MAINLY LATE TONIGHT
INTO SATURDAY MORNING.
FORECASTED TEMPERATURES...PER RECENT GFS AND NAM MOS...TO BECOME
NOTICEABLY COLDER WITH LOWS TONIGHT NEAR NORMAL BUT HIGHS SATURDAY
ABOUT 10 DEGREES COLDER THAN NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
FRONT WILL CONTINUE ITS PROGRESSION ACROSS THE REGION BRINGING A
GOOD CHANCE FOR RAIN THROUGH SATURDAY AFTERNOON. MODELS CONTINUE
TO STALL THE FRONT SOMEWHERE ALONG THE MASON-DIXON LINE SATURDAY
NIGHT BEFORE ANOTHER SHORTWAVE FINALLY PUSHES IT COMPLETELY SOUTH
AND EAST. DECIDED TO CUT BACK POPS FOR THE SATURDAY NIGHT PERIOD
THOUGH SOME POST FRONTAL SHOWERS COULD BE POSSIBLE IN NORTHWEST
FLOW AND COOLING 850 TEMPERATURES.
THE NEWEST MODEL RUNS ARE STARTING TO AGREE BETTER ON STRONGER
SECONDARY SHORTWAVE EXPECTED TO CROSS THE OHIO VALLEY SUNDAY. THE
ECMWF IS THE SLOWEST AND FURTHER NORTH WITH THE EXTENT OF PRECIP
BUT EVEN WITH THE MORE SOUTHERLY GFS...NORTHWESTERLY FLOW BEHIND
THE WAVE WOULD ONCE AGAIN BRING PRECIPITATION FOR MUCH OF THE AREA
SUNDAY AFTERNOON. WILL KEEP CHANCE POPS FOR MUCH OF THE AREA WITH
LIKELYS ON THE RIDGES. WEST/NORTHWEST UPPER LEVEL FLOW WILL
PERSIST AFTER PASSAGE OF THE SHORTWAVE MAINTAINING THE CHANCE FOR
SHOWERS AND EVEN A FEW SNOW SHOWERS IN THE HIGHER ELEVATIONS AND
POINTS NORTH OF I-80 SUNDAY NIGHT AS 850HPA TEMPERATURES REMAIN AT
-2C.
STRONG COLD ADVECTION WITH THE PASSAGE OF THE FRONT AND SECONDARY
SHORTWAVE WILL KEEP TEMPERATURES 5-10 DEGREES BELOW NORMAL THROUGH
MONDAY. HIGH PRESSURE RIDGE AND BACKING WINDS WILL CUT OFF
PRECIPITATION LATE SUNDAY NIGHT BRINGING THE POSSIBILITY OF A
FREEZE IN SOME COUNTIES BY DAYBREAK. BUT...WITH UNCERTAINTY IN
THE AMOUNT OF CLOUD COVER WILL LEAVE OUT MENTION IN FORECAST FOR
NOW.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN IN CONTROL TUESDAY...HELPING TO MODERATE
TEMPERATURES TO CLOSER TO NORMAL VALUES. A SOUTHEASTBOUND CANADIAN
COLD FRONT WILL PROVIDE A CHANCE OF SHOWERS TUESDAY NIGHT AND
WEDNESDAY.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
VFR IS FORECAST THROUGH THIS AFTN AS SWLY FLOW DVLPS IN ADVN OF A
CDFNT SLOWLY MOVING ACRS THE MIDWEST.
.OUTLOOK.../TONIGHT THROUGH TUESDAY/...
RESTRICTION POTENTIAL WL INCRS ON THIS EVE AS THE FRONT AND SHRA MOVE
OVR THE UPR OH VALLEY REGION. WIDESPREAD MVFR STRATOCU AND
PERIODIC SHRA CAN BE EXPECTED IN THE STRONG COLD ADVCTN REGIME
BEHIND THE FRONT. VFR IS EXPECTED TO RTN WITH MONDAY HIGH PRES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1256 PM EDT FRI OCT 5 2012
.AVIATION...
//DISCUSSION...
SHALLOW POST FRONTAL COLD AIR ADVECTION LED TO THE DEVELOPMENT OF
SOME MVFR BASED STRATUS THIS MORNING. THERE IS ENOUGH DRY AIR MIXING
INTO THE INVERSION THAT THESE CLOUDS HAVE BEEN DECREASING IN
COVERAGE...WHILE CONTINUED LOW LEVEL COLD AIR ADVECTION AND DAYTIME
HEATING LIFT INVERSION BASES. A REGION OF SHOWERS ACROSS NORTH
CENTRAL IL AND SRN IOWA WILL LIFT INTO SE MI THIS AFTERNOON...
PRIMARILY AFTER 21Z. THIS FORCING SHOULD PERSIST THROUGH ROUGHLY 03Z
BEFORE MOVING OFF TO THE EAST. PATCHES OF STRATO CU SHOULD PERSIST
WELL THROUGH THE NIGHT UNDER CONTINUED LOW LEVEL COLD AIR ADVECTION.
THE INCREASING DEPTH OF COLD AIR SHOULD HOWEVER KEEP BASES ABOVE
3000 FT.
FOR DTW...AT LEAST SOME PATCHES OF RAIN ARE EXPECTED TO TRAVERSE
METRO THIS EVENING. BEING A LITTLE CLOSER TO THE SFC COLD
FRONT...INVERSION BASES AND THUS CEILING HEIGHTS WILL LIKELY BE A
TOUCH LOWER THAN LOCATIONS FARTHER NORTH...POSSIBLY FALLING IN THE
3500 TO 4500 FT RANGE. CONFIDENCE ON CEILING HEIGHTS HOWEVER IS
RATHER LOW GIVEN SOME ONGOING ENTRAINMENT OF DRY AIR.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILING HEIGHTS BELOW 5000 FT TODAY AND TONIGHT.
&&
.PREV DISCUSSION...ISSUED 1040 AM EDT FRI OCT 5 2012
UPDATE...
AS OF 14Z...THE POST FRONTAL SHOWERS/THUNDERSTORMS EXTEND FROM S
CNTL MO TO W CNTL LAKE ERIE. THE SHOWERS HAVE REMAINED SOUTH OF
THE FORECAST AREA THIS MORNING AND RECENT RADAR TRENDS SUGGEST THE
FORECAST AREA WILL REMAIN DRY THROUGH AT LEAST EARLY AFTERNOON.
THE AMOUNT OF CONVECTION ALONG THE LOWER LEVELS OF THE FRONTAL
SLOPE /ROUGHLY IN THE 925-850MB LAYER/ HAS BEEN MORE EXTENSIVE
THAN EARLIER MODEL SOLUTIONS SUGGESTED DUE IN PART TO THE DEEP
LAYER OF CONVECTIVE INSTABILITY IN THIS REGION. THUS THE MID
LEVEL PORTIONS OF THE FRONT /WHICH EXTEND ACROSS SE MI/ HAVE THUS
FAR BEEN INACTIVE. SATELLITE DATA IS HOWEVER SHOWING A MID LEVEL
IMPULSE ROTATING INTO IOWA...FORECAST TO LIFT INTO LOWER MI THIS
EVENING. THE APPROACH OF THIS WAVE ALONG WITH AN INTENSIFICATION
OF AN UPPER LEVEL JET STREAK ADVANCING ACROSS THE NRN GREAT LAKES
THIS AFTERNOON SHOULD ENHANCE FRONTOGENESIS ALONG THE ELEVATED
FRONT /850-700MB LAYER/ DRAPED ACROSS SE MI. THIS FORCING IS NOT
EXPECTED TO ARRIVE IN SE MI UNTIL 21Z AND SHOULD PERSIST INTO AT
LEAST 03Z. WHILE THE BETTER CHANCES OF SHOWERS WILL OCCUR ALONG
AND SOUTH OF A BAD AXE TO OWOSSO LINE...THERE IS A POTENTIAL THAT
THE ELEVATED FRONT WILL BECOME MORE ACTIVE FARTHER NORTH...WHICH
WILL SUPPORT ADDING AT LEAST A CHANCE OF LATE DAY SHOWERS TO THE
TRI CITIES. WILL BE UPDATING THE FORECAST TO REFLECT THESE
CHANGES.
MEANWHILE...STRATO CU HAS BEEN DEVELOPING ACROSS SRN MI THIS
MORNING. THE 12Z DTX SOUNDING SHOWED A FAIRLY DEEP INVERSION BASED
NEAR 900MB...WITH AMPLE INSTABILITY BELOW TO ALLOW ENHANCEMENT TO
THE CLOUD FIELD OFF LAKE MICHIGAN. THIS WILL SUPPORT BOOSTING
CLOUD COVER A BIT AND KNOCKING A DEGREE OR TWO OFF AFTERNOON
HIGHS.
THE UPDATED ZFP AND GRIDS WILL BE ISSUED SHORTLY.
PREV DISCUSSION...ISSUED 356 AM EDT FRI OCT 5 2012
SHORT TERM...TODAY AND TONIGHT
NOW THAT THE SURFACE COLD FRONT HAS CLEARED THE AREA, MODERATE COLD
ADVECTION HAS BEGUN AND IS FORECAST TO CONTINUE WITH 850MB
TEMPERATURES FALLING TO SLIGHTLY BELOW ZERO BY 06Z TONIGHT. THE MOST
NOTEWORTHY CHANGE MADE TO TODAY`S FORECAST PACKAGE WAS TO TREND
TODAY`S HIGH TEMPERATURES DOWNWARD A COUPLE OF DEGREES. ALL
LOCATIONS STAND A GOOD CHANCE TO REMAIN IN THE 50S FOR THE BALANCE
OF THE DAY AS EARLY OCTOBER DIURNAL HEATING WILL HAVE TO CONTEND
WITH NOT ONLY WITH ONGOING COLD ADVECTION, BUT ALSO WIDESPREAD MID
AND UPPER CLOUDS. IN ADDITION, UPSTREAM LOCATIONS THAT SPENT THE
DAYTIME HOURS THURSDAY IN THE POST-FRONTAL ENVIRONMENT GENERALLY
ROSE INTO THE LOW 50S. AFTER GIVING CONSIDERATION TO THE HEAT
CONTRIBUTION FROM LAKE MICHIGAN, WHERE LAKE SFC TEMPS REMAIN IN THE
LOW 60S, HIGHS FOR TODAY WERE GIVEN A DOWNWARD ADJUSTMENT INTO THE
55-58 DEGREE RANGE. A FEW 60S STILL CAN`T BE RULED OUT SHOULD CLOUDS
BREAK DURING PEAK HEATING, MOST LIKELY NORTH OF M-59.
THE OTHER FORECAST ISSUE FOR TODAY IS THE PLACEMENT AND DURATION OF
A BAND OF SHOWERS THAT IS CURRENTLY TAKING SHAPE OVER MO/IL. WATER
VAPOR IMAGERY SHOWS AN ENERGETIC ZONAL FLOW ACROSS THE CENTRAL U.S.
WITH EMBEDDED LOW AMPLITUDE SHORTWAVES PROPAGATING ACROSS THE PLAINS
STATES. SHOWER COVERAGE IS EXPANDING AHEAD OF THIS ENERGY AND IN
ASSOCIATION WITH A DEVELOPING FGEN RESPONSE UNDER THE RIGHT ENTRANCE
OF A STRENGTHENING 90KT JET STREAK. THE 00Z GUIDANCE, IN PARTICULAR
THE NAM AND RECENT 3-KM HRRR SIMULATIONS, LOOK SOLID IN THEIR
REPRESENTATION OF THE DEVELOPING FRONTAL CIRCULATION AND ASSOCIATED
PRECIPITATION COVERAGE. FOR NOW, THE ONLY COMPLAINT IS THAT THE
RESPONSE WITHIN THE LOW STATIC STABILITY ENVIRONMENT LEADING THE
ARRIVAL OF THE JET CORE LOOKS HEALTHY, SO LEANED TOWARD AN EARLIER
12-13Z ARRIVAL TIME FOR SOUTHERN AREAS. THE NORTH SIDE OF THE PRECIP
SHIELD WILL INITIALLY CARRY THE SHARP CUTOFF EVIDENT ON THE REGIONAL
RADAR MOSAIC INTO THE AREA, CASTING SOME UNCERTAINTY ON ITS
NORTHWARD EXTENT AS IT STRADDLES THE METRO DETROIT AREA INTO THE
AFTERNOON. HOWEVER, ADDITIONAL NORTHWARD EXPANSION SEEMS PROBABLE
THIS AFTERNOON AS THE POTENT SHORTWAVE ENERGY OVER ID/WY AT 07Z
ACCELERATES TOWARD THE AREA LATER TODAY. LAKE CLOUDS WILL THEN BUILD
INTO THE AREA LATE TONIGHT COINCIDENT WITH THE APPROACH OF THE UPPER
TROUGH AXIS AND H85-SFC DELTA T VALUES PLUMMETING TO 20C OVER LM.
THE STAGE WILL THEN BE SET FOR A COLD START TO SATURDAY MORNING AS
LOW TEMPS DIP INTO THE MID TO UPPER 30S UNDERNEATH INCREASING
BOUNDARY LAYER SKY COVER.
LONG TERM...SATURDAY THROUGH THURSDAY
AS UPPER LOW SHIFTS JUST NORTH OF LAKE SUPERIOR IS PULLED NORTHEAST
INTO BROADER HUDSON BAY VORTEX...UPPER TROUGH AXIS WILL SWING ACROSS
LOWER MICHIGAN AND BRING A SECOND SHOT OF COLD AIR INTO THE AREA ON
SATURDAY. WITH H85 TEMPERATURES FALLING SOLIDLY BELOW 0C...EXPECT
HIGH TEMPERATURES TO REMAIN BETWEEN 50 AND 55. WHILE BEST LIFT AND
FORCING WITH THE VORTICITY CENTER ALONG THIS TROUGH WILL REMAIN TO
THE NORTH OF THE AREA...THERE WILL BE A SMALL CHANCE OF SHOWERS IN
THE 20-30% RANGE AS WRAPAROUND MOISTURE BRUSHES THE AREA AND LAKE
EFFECT ACTIVITY BEGINS TO EXPAND IN THE COLDER AIR.
AFTER ANOTHER DAY WITH HIGH TEMPERATURES AOB 55F ON SUNDAY (WITH
EARLY MORNING TEMPERATURES MOST LIKELY REACHING FREEZING IN SOME
LOCATIONS)...THE NEXT STRONG SHORTWAVE PIVOTING THROUGH THE NORTHERN
GREAT LAKES AROUND THE HUDSON VORTEX WILL BRING A MODERATING TREND
IN THE MONDAY AND TUESDAY TIME FRAME AS SOUTHWEST FLOW BECOMES
ESTABLISHED IN ADVANCE OF THE NEXT STRONG COLD FRONT WHICH WILL
SHIFT INTO THE AREA AS THIS SECOND NORTHERN STREAM STORM SYSTEM
WRAPS NORTHEAST INTO THE AFOREMENTIONED VORTEX. TEMPERATURES WILL
CLIMB WELL INTO THE 50S ON MONDAY AND TO 60 OR BETTER ON TUESDAY AS
THE ARRIVAL OF THIS COLD FRONT IS DELAYED SLIGHTLY AS LOW PRESSURE
RIPPLES UP ALONG IT.
THIS SOUTHERN STREAM LOW PRESSURE WILL BRING THE BEST CHANCE OF
RAINFALL IN THE EXTENDED PORTION OF THE FORECAST AS STRONG FORCING
SHIFTS THROUGH THE AREA WITH THIS PASSAGE OF THIS SYSTEM TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING...WITH ONLY MINOR LAKE EFFECT
ACTIVITY EXPECTED LATER WEDNESDAY INTO THURSDAY SOUTHEAST OF LAKE
HURON.
TEMPERATURES WILL COOL BACK INTO THE MID 50S ON WEDNESDAY...BUT WITH
NORTHERN STREAM SHORTWAVE TAKING A WESTERLY TRACK NORTH OF THE GREAT
LAKES...THE COLDEST AIR WITH THIS SYSTEM WILL REMAIN OVER CANADA AND
EXPECT TEMPERATURES TO REBOUND TO THE UPPER 50S TO AROUND 60 BY
THURSDAY.
MARINE...
A FRESH WEST-SOUTHWEST BREEZE WILL GUST INTO THE 25 TO 30 KNOT RANGE
TODAY AS A COOL AND UNSTABLE AIRMASS OVERSPREADS AREA WATERS. A FEW
GUSTS TO LOW END GALE FORCE WILL BE POSSIBLE FROM OUTER SAGINAW BAY
INTO CENTRAL LAKE HURON THIS AFTERNOON...BUT NO ORGANIZED OR
WIDESPREAD GALES ARE EXPECTED. WINDS WILL GRADUALLY EASE BY LATE
FRIDAY NIGHT BUT WAVES WILL REMAIN REMAIN ELEVATED INTO SATURDAY
MORNING. ALL SMALL CRAFT ADVISORIES THEREFORE REMAIN IN EFFECT FOR
SAGINAW BAY AND THE NEARSHORE FROM PORT AUSTIN TO HARBOR BEACH UNTIL
SATURDAY MORNING. A RENEWED SURGE OF GUSTY WINDS WILL DEVELOP AHEAD
OF ANOTHER PUSH OF COLD AIR ON SATURDAY. A BRIEF REPRIEVE CAN BE
EXPECTED ON SUNDAY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE
AREA...BUT UNSETTLED CONDITIONS WILL QUICKLY REDEVELOP AS THE
SURFACE PRESSURE GRADIENT STRENGTHENS EARLY NEXT WEEK. SOUTH WINDS
WILL INCREASE TO 20 TO 25 KNOTS BY LATE MONDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
PORT AUSTIN TO HARBOR BEACH...UNTIL 8 AM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...JVC
LONG TERM....DG
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1040 AM EDT FRI OCT 5 2012
.UPDATE...
AS OF 14Z...THE POST FRONTAL SHOWERS/THUNDERSTORMS EXTEND FROM S
CNTL MO TO W CNTL LAKE ERIE. THE SHOWERS HAVE REMAINED SOUTH OF
THE FORECAST AREA THIS MORNING AND RECENT RADAR TRENDS SUGGEST THE
FORECAST AREA WILL REMAIN DRY THROUGH AT LEAST EARLY AFTERNOON.
THE AMOUNT OF CONVECTION ALONG THE LOWER LEVELS OF THE FRONTAL
SLOPE /ROUGHLY IN THE 925-850MB LAYER/ HAS BEEN MORE EXTENSIVE
THAN EARLIER MODEL SOLUTIONS SUGGESTED DUE IN PART TO THE DEEP
LAYER OF CONVECTIVE INSTABILITY IN THIS REGION. THUS THE MID
LEVEL PORTIONS OF THE FRONT /WHICH EXTEND ACROSS SE MI/ HAVE THUS
FAR BEEN INACTIVE. SATELLITE DATA IS HOWEVER SHOWING A MID LEVEL
IMPULSE ROTATING INTO IOWA...FORECAST TO LIFT INTO LOWER MI THIS
EVENING. THE APPROACH OF THIS WAVE ALONG WITH AN INTENSIFICATION
OF AN UPPER LEVEL JET STREAK ADVANCING ACROSS THE NRN GREAT LAKES
THIS AFTERNOON SHOULD ENHANCE FRONTOGENESIS ALONG THE ELEVATED
FRONT /850-700MB LAYER/ DRAPED ACROSS SE MI. THIS FORCING IS NOT
EXPECTED TO ARRIVE IN SE MI UNTIL 21Z AND SHOULD PERSIST INTO AT
LEAST 03Z. WHILE THE BETTER CHANCES OF SHOWERS WILL OCCUR ALONG
AND SOUTH OF A BAD AXE TO OWOSSO LINE...THERE IS A POTENTIAL THAT
THE ELEVATED FRONT WILL BECOME MORE ACTIVE FARTHER NORTH...WHICH
WILL SUPPORT ADDING AT LEAST A CHANCE OF LATE DAY SHOWERS TO THE
TRI CITIES. WILL BE UPDATING THE FORECAST TO REFLECT THESE
CHANGES.
MEANWHILE...STRATO CU HAS BEEN DEVELOPING ACROSS SRN MI THIS
MORNING. THE 12Z DTX SOUNDING SHOWED A FAIRLY DEEP INVERSION BASED
NEAR 900MB...WITH AMPLE INSTABILITY BELOW TO ALLOW ENHANCEMENT TO
THE CLOUD FIELD OFF LAKE MICHIGAN. THIS WILL SUPPORT BOOSTING
CLOUD COVER A BIT AND KNOCKING A DEGREE OR TWO OFF AFTERNOON
HIGHS.
THE UPDATED ZFP AND GRIDS WILL BE ISSUED SHORTLY.
&&
.AVIATION...ISSUED 654 AM EDT FRI OCT 5 2012
//DISCUSSION...
WEST WINDS OF 10 TO 15 KNOTS WILL OCCASIONALLY GUST TO 20 KNOTS
TODAY, ESPECIALLY ACROSS NORTHERN AREAS WHERE DIURNAL HEATING IS
EXPECTED TO BE STRONGER. SHOWERS DEVELOPING UPSTREAM WILL SPREAD
INTO THE AREA THROUGH THE MORNING, REACHING THE DETROIT AIRFIELDS
BY EARLY THIS AFTERNOON. CEILINGS STAND A GOOD CHANCE OF FALLING
BELOW 5000 FEET AND POSSIBLY INTO THE MVFR RANGE WITH THIS
ACTIVITY. CONDITIONS WILL IMPROVE AS THE SHOWERS SHIFT EAST LATE
THIS EVENING. DEVELOPING NORTHWEST FLOW WILL RESULT IN LAKE CLOUD
DEVELOPMENT FOR SATURDAY.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5000 FEET BY LATE THIS MORNING
AND AGAIN BY LATE SATURDAY MORNING.
&&
.PREV DISCUSSION...ISSUED 356 AM EDT FRI OCT 5 2012
SHORT TERM...TODAY AND TONIGHT
NOW THAT THE SURFACE COLD FRONT HAS CLEARED THE AREA, MODERATE COLD
ADVECTION HAS BEGUN AND IS FORECAST TO CONTINUE WITH 850MB
TEMPERATURES FALLING TO SLIGHTLY BELOW ZERO BY 06Z TONIGHT. THE MOST
NOTEWORTHY CHANGE MADE TO TODAY`S FORECAST PACKAGE WAS TO TREND
TODAY`S HIGH TEMPERATURES DOWNWARD A COUPLE OF DEGREES. ALL
LOCATIONS STAND A GOOD CHANCE TO REMAIN IN THE 50S FOR THE BALANCE
OF THE DAY AS EARLY OCTOBER DIURNAL HEATING WILL HAVE TO CONTEND
WITH NOT ONLY WITH ONGOING COLD ADVECTION, BUT ALSO WIDESPREAD MID
AND UPPER CLOUDS. IN ADDITION, UPSTREAM LOCATIONS THAT SPENT THE
DAYTIME HOURS THURSDAY IN THE POST-FRONTAL ENVIRONMENT GENERALLY
ROSE INTO THE LOW 50S. AFTER GIVING CONSIDERATION TO THE HEAT
CONTRIBUTION FROM LAKE MICHIGAN, WHERE LAKE SFC TEMPS REMAIN IN THE
LOW 60S, HIGHS FOR TODAY WERE GIVEN A DOWNWARD ADJUSTMENT INTO THE
55-58 DEGREE RANGE. A FEW 60S STILL CAN`T BE RULED OUT SHOULD CLOUDS
BREAK DURING PEAK HEATING, MOST LIKELY NORTH OF M-59.
THE OTHER FORECAST ISSUE FOR TODAY IS THE PLACEMENT AND DURATION OF
A BAND OF SHOWERS THAT IS CURRENTLY TAKING SHAPE OVER MO/IL. WATER
VAPOR IMAGERY SHOWS AN ENERGETIC ZONAL FLOW ACROSS THE CENTRAL U.S.
WITH EMBEDDED LOW AMPLITUDE SHORTWAVES PROPAGATING ACROSS THE PLAINS
STATES. SHOWER COVERAGE IS EXPANDING AHEAD OF THIS ENERGY AND IN
ASSOCIATION WITH A DEVELOPING FGEN RESPONSE UNDER THE RIGHT ENTRANCE
OF A STRENGTHENING 90KT JET STREAK. THE 00Z GUIDANCE, IN PARTICULAR
THE NAM AND RECENT 3-KM HRRR SIMULATIONS, LOOK SOLID IN THEIR
REPRESENTATION OF THE DEVELOPING FRONTAL CIRCULATION AND ASSOCIATED
PRECIPITATION COVERAGE. FOR NOW, THE ONLY COMPLAINT IS THAT THE
RESPONSE WITHIN THE LOW STATIC STABILITY ENVIRONMENT LEADING THE
ARRIVAL OF THE JET CORE LOOKS HEALTHY, SO LEANED TOWARD AN EARLIER
12-13Z ARRIVAL TIME FOR SOUTHERN AREAS. THE NORTH SIDE OF THE PRECIP
SHIELD WILL INITIALLY CARRY THE SHARP CUTOFF EVIDENT ON THE REGIONAL
RADAR MOSAIC INTO THE AREA, CASTING SOME UNCERTAINTY ON ITS
NORTHWARD EXTENT AS IT STRADDLES THE METRO DETROIT AREA INTO THE
AFTERNOON. HOWEVER, ADDITIONAL NORTHWARD EXPANSION SEEMS PROBABLE
THIS AFTERNOON AS THE POTENT SHORTWAVE ENERGY OVER ID/WY AT 07Z
ACCELERATES TOWARD THE AREA LATER TODAY. LAKE CLOUDS WILL THEN BUILD
INTO THE AREA LATE TONIGHT COINCIDENT WITH THE APPROACH OF THE UPPER
TROUGH AXIS AND H85-SFC DELTA T VALUES PLUMMETING TO 20C OVER LM.
THE STAGE WILL THEN BE SET FOR A COLD START TO SATURDAY MORNING AS
LOW TEMPS DIP INTO THE MID TO UPPER 30S UNDERNEATH INCREASING
BOUNDARY LAYER SKY COVER.
LONG TERM...SATURDAY THROUGH THURSDAY
AS UPPER LOW SHIFTS JUST NORTH OF LAKE SUPERIOR IS PULLED NORTHEAST
INTO BROADER HUDSON BAY VORTEX...UPPER TROUGH AXIS WILL SWING ACROSS
LOWER MICHIGAN AND BRING A SECOND SHOT OF COLD AIR INTO THE AREA ON
SATURDAY. WITH H85 TEMPERATURES FALLING SOLIDLY BELOW 0C...EXPECT
HIGH TEMPERATURES TO REMAIN BETWEEN 50 AND 55. WHILE BEST LIFT AND
FORCING WITH THE VORTICITY CENTER ALONG THIS TROUGH WILL REMAIN TO
THE NORTH OF THE AREA...THERE WILL BE A SMALL CHANCE OF SHOWERS IN
THE 20-30% RANGE AS WRAPAROUND MOISTURE BRUSHES THE AREA AND LAKE
EFFECT ACTIVITY BEGINS TO EXPAND IN THE COLDER AIR.
AFTER ANOTHER DAY WITH HIGH TEMPERATURES AOB 55F ON SUNDAY (WITH
EARLY MORNING TEMPERATURES MOST LIKELY REACHING FREEZING IN SOME
LOCATIONS)...THE NEXT STRONG SHORTWAVE PIVOTING THROUGH THE NORTHERN
GREAT LAKES AROUND THE HUDSON VORTEX WILL BRING A MODERATING TREND
IN THE MONDAY AND TUESDAY TIME FRAME AS SOUTHWEST FLOW BECOMES
ESTABLISHED IN ADVANCE OF THE NEXT STRONG COLD FRONT WHICH WILL
SHIFT INTO THE AREA AS THIS SECOND NORTHERN STREAM STORM SYSTEM
WRAPS NORTHEAST INTO THE AFOREMENTIONED VORTEX. TEMPERATURES WILL
CLIMB WELL INTO THE 50S ON MONDAY AND TO 60 OR BETTER ON TUESDAY AS
THE ARRIVAL OF THIS COLD FRONT IS DELAYED SLIGHTLY AS LOW PRESSURE
RIPPLES UP ALONG IT.
THIS SOUTHERN STREAM LOW PRESSURE WILL BRING THE BEST CHANCE OF
RAINFALL IN THE EXTENDED PORTION OF THE FORECAST AS STRONG FORCING
SHIFTS THROUGH THE AREA WITH THIS PASSAGE OF THIS SYSTEM TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING...WITH ONLY MINOR LAKE EFFECT
ACTIVITY EXPECTED LATER WEDNESDAY INTO THURSDAY SOUTHEAST OF LAKE
HURON.
TEMPERATURES WILL COOL BACK INTO THE MID 50S ON WEDNESDAY...BUT WITH
NORTHERN STREAM SHORTWAVE TAKING A WESTERLY TRACK NORTH OF THE GREAT
LAKES...THE COLDEST AIR WITH THIS SYSTEM WILL REMAIN OVER CANADA AND
EXPECT TEMPERATURES TO REBOUND TO THE UPPER 50S TO AROUND 60 BY
THURSDAY.
MARINE...
A FRESH WEST-SOUTHWEST BREEZE WILL GUST INTO THE 25 TO 30 KNOT RANGE
TODAY AS A COOL AND UNSTABLE AIRMASS OVERSPREADS AREA WATERS. A FEW
GUSTS TO LOW END GALE FORCE WILL BE POSSIBLE FROM OUTER SAGINAW BAY
INTO CENTRAL LAKE HURON THIS AFTERNOON...BUT NO ORGANIZED OR
WIDESPREAD GALES ARE EXPECTED. WINDS WILL GRADUALLY EASE BY LATE
FRIDAY NIGHT BUT WAVES WILL REMAIN REMAIN ELEVATED INTO SATURDAY
MORNING. ALL SMALL CRAFT ADVISORIES THEREFORE REMAIN IN EFFECT FOR
SAGINAW BAY AND THE NEARSHORE FROM PORT AUSTIN TO HARBOR BEACH UNTIL
SATURDAY MORNING. A RENEWED SURGE OF GUSTY WINDS WILL DEVELOP AHEAD
OF ANOTHER PUSH OF COLD AIR ON SATURDAY. A BRIEF REPRIEVE CAN BE
EXPECTED ON SUNDAY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE
AREA...BUT UNSETTLED CONDITIONS WILL QUICKLY REDEVELOP AS THE
SURFACE PRESSURE GRADIENT STRENGTHENS EARLY NEXT WEEK. SOUTH WINDS
WILL INCREASE TO 20 TO 25 KNOTS BY LATE MONDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
PORT AUSTIN TO HARBOR BEACH...UNTIL 8 AM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SC
AVIATION.....DG
SHORT TERM...JVC
LONG TERM....DG
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
654 AM EDT FRI OCT 5 2012
.AVIATION...
//DISCUSSION...
WEST WINDS OF 10 TO 15 KNOTS WILL OCCASIONALLY GUST TO 20 KNOTS
TODAY, ESPECIALLY ACROSS NORTHERN AREAS WHERE DIURNAL HEATING IS
EXPECTED TO BE STRONGER. SHOWERS DEVELOPING UPSTREAM WILL SPREAD
INTO THE AREA THROUGH THE MORNING, REACHING THE DETROIT AIRFIELDS
BY EARLY THIS AFTERNOON. CEILINGS STAND A GOOD CHANCE OF FALLING
BELOW 5000 FEET AND POSSIBLY INTO THE MVFR RANGE WITH THIS
ACTIVITY. CONDITIONS WILL IMPROVE AS THE SHOWERS SHIFT EAST LATE
THIS EVENING. DEVELOPING NORTHWEST FLOW WILL RESULT IN LAKE CLOUD
DEVELOPMENT FOR SATURDAY.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5000 FEET BY LATE THIS MORNING
AND AGAIN BY LATE SATURDAY MORNING.
&&
.PREV DISCUSSION...ISSUED 356 AM EDT FRI OCT 5 2012
SHORT TERM...TODAY AND TONIGHT
NOW THAT THE SURFACE COLD FRONT HAS CLEARED THE AREA, MODERATE COLD
ADVECTION HAS BEGUN AND IS FORECAST TO CONTINUE WITH 850MB
TEMPERATURES FALLING TO SLIGHTLY BELOW ZERO BY 06Z TONIGHT. THE MOST
NOTEWORTHY CHANGE MADE TO TODAY`S FORECAST PACKAGE WAS TO TREND
TODAY`S HIGH TEMPERATURES DOWNWARD A COUPLE OF DEGREES. ALL
LOCATIONS STAND A GOOD CHANCE TO REMAIN IN THE 50S FOR THE BALANCE
OF THE DAY AS EARLY OCTOBER DIURNAL HEATING WILL HAVE TO CONTEND
WITH NOT ONLY WITH ONGOING COLD ADVECTION, BUT ALSO WIDESPREAD MID
AND UPPER CLOUDS. IN ADDITION, UPSTREAM LOCATIONS THAT SPENT THE
DAYTIME HOURS THURSDAY IN THE POST-FRONTAL ENVIRONMENT GENERALLY
ROSE INTO THE LOW 50S. AFTER GIVING CONSIDERATION TO THE HEAT
CONTRIBUTION FROM LAKE MICHIGAN, WHERE LAKE SFC TEMPS REMAIN IN THE
LOW 60S, HIGHS FOR TODAY WERE GIVEN A DOWNWARD ADJUSTMENT INTO THE
55-58 DEGREE RANGE. A FEW 60S STILL CAN`T BE RULED OUT SHOULD CLOUDS
BREAK DURING PEAK HEATING, MOST LIKELY NORTH OF M-59.
THE OTHER FORECAST ISSUE FOR TODAY IS THE PLACEMENT AND DURATION OF
A BAND OF SHOWERS THAT IS CURRENTLY TAKING SHAPE OVER MO/IL. WATER
VAPOR IMAGERY SHOWS AN ENERGETIC ZONAL FLOW ACROSS THE CENTRAL U.S.
WITH EMBEDDED LOW AMPLITUDE SHORTWAVES PROPAGATING ACROSS THE PLAINS
STATES. SHOWER COVERAGE IS EXPANDING AHEAD OF THIS ENERGY AND IN
ASSOCIATION WITH A DEVELOPING FGEN RESPONSE UNDER THE RIGHT ENTRANCE
OF A STRENGTHENING 90KT JET STREAK. THE 00Z GUIDANCE, IN PARTICULAR
THE NAM AND RECENT 3-KM HRRR SIMULATIONS, LOOK SOLID IN THEIR
REPRESENTATION OF THE DEVELOPING FRONTAL CIRCULATION AND ASSOCIATED
PRECIPITATION COVERAGE. FOR NOW, THE ONLY COMPLAINT IS THAT THE
RESPONSE WITHIN THE LOW STATIC STABILITY ENVIRONMENT LEADING THE
ARRIVAL OF THE JET CORE LOOKS HEALTHY, SO LEANED TOWARD AN EARLIER
12-13Z ARRIVAL TIME FOR SOUTHERN AREAS. THE NORTH SIDE OF THE PRECIP
SHIELD WILL INITIALLY CARRY THE SHARP CUTOFF EVIDENT ON THE REGIONAL
RADAR MOSAIC INTO THE AREA, CASTING SOME UNCERTAINTY ON ITS
NORTHWARD EXTENT AS IT STRADDLES THE METRO DETROIT AREA INTO THE
AFTERNOON. HOWEVER, ADDITIONAL NORTHWARD EXPANSION SEEMS PROBABLE
THIS AFTERNOON AS THE POTENT SHORTWAVE ENERGY OVER ID/WY AT 07Z
ACCELERATES TOWARD THE AREA LATER TODAY. LAKE CLOUDS WILL THEN BUILD
INTO THE AREA LATE TONIGHT COINCIDENT WITH THE APPROACH OF THE UPPER
TROUGH AXIS AND H85-SFC DELTA T VALUES PLUMMETING TO 20C OVER LM.
THE STAGE WILL THEN BE SET FOR A COLD START TO SATURDAY MORNING AS
LOW TEMPS DIP INTO THE MID TO UPPER 30S UNDERNEATH INCREASING
BOUNDARY LAYER SKY COVER.
LONG TERM...SATURDAY THROUGH THURSDAY
AS UPPER LOW SHIFTS JUST NORTH OF LAKE SUPERIOR IS PULLED NORTHEAST
INTO BROADER HUDSON BAY VORTEX...UPPER TROUGH AXIS WILL SWING ACROSS
LOWER MICHIGAN AND BRING A SECOND SHOT OF COLD AIR INTO THE AREA ON
SATURDAY. WITH H85 TEMPERATURES FALLING SOLIDLY BELOW 0C...EXPECT
HIGH TEMPERATURES TO REMAIN BETWEEN 50 AND 55. WHILE BEST LIFT AND
FORCING WITH THE VORTICITY CENTER ALONG THIS TROUGH WILL REMAIN TO
THE NORTH OF THE AREA...THERE WILL BE A SMALL CHANCE OF SHOWERS IN
THE 20-30% RANGE AS WRAPAROUND MOISTURE BRUSHES THE AREA AND LAKE
EFFECT ACTIVITY BEGINS TO EXPAND IN THE COLDER AIR.
AFTER ANOTHER DAY WITH HIGH TEMPERATURES AOB 55F ON SUNDAY (WITH
EARLY MORNING TEMPERATURES MOST LIKELY REACHING FREEZING IN SOME
LOCATIONS)...THE NEXT STRONG SHORTWAVE PIVOTING THROUGH THE NORTHERN
GREAT LAKES AROUND THE HUDSON VORTEX WILL BRING A MODERATING TREND
IN THE MONDAY AND TUESDAY TIME FRAME AS SOUTHWEST FLOW BECOMES
ESTABLISHED IN ADVANCE OF THE NEXT STRONG COLD FRONT WHICH WILL
SHIFT INTO THE AREA AS THIS SECOND NORTHERN STREAM STORM SYSTEM
WRAPS NORTHEAST INTO THE AFOREMENTIONED VORTEX. TEMPERATURES WILL
CLIMB WELL INTO THE 50S ON MONDAY AND TO 60 OR BETTER ON TUESDAY AS
THE ARRIVAL OF THIS COLD FRONT IS DELAYED SLIGHTLY AS LOW PRESSURE
RIPPLES UP ALONG IT.
THIS SOUTHERN STREAM LOW PRESSURE WILL BRING THE BEST CHANCE OF
RAINFALL IN THE EXTENDED PORTION OF THE FORECAST AS STRONG FORCING
SHIFTS THROUGH THE AREA WITH THIS PASSAGE OF THIS SYSTEM TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING...WITH ONLY MINOR LAKE EFFECT
ACTIVITY EXPECTED LATER WEDNESDAY INTO THURSDAY SOUTHEAST OF LAKE
HURON.
TEMPERATURES WILL COOL BACK INTO THE MID 50S ON WEDNESDAY...BUT WITH
NORTHERN STREAM SHORTWAVE TAKING A WESTERLY TRACK NORTH OF THE GREAT
LAKES...THE COLDEST AIR WITH THIS SYSTEM WILL REMAIN OVER CANADA AND
EXPECT TEMPERATURES TO REBOUND TO THE UPPER 50S TO AROUND 60 BY
THURSDAY.
MARINE...
A FRESH WEST-SOUTHWEST BREEZE WILL GUST INTO THE 25 TO 30 KNOT RANGE
TODAY AS A COOL AND UNSTABLE AIRMASS OVERSPREADS AREA WATERS. A FEW
GUSTS TO LOW END GALE FORCE WILL BE POSSIBLE FROM OUTER SAGINAW BAY
INTO CENTRAL LAKE HURON THIS AFTERNOON...BUT NO ORGANIZED OR
WIDESPREAD GALES ARE EXPECTED. WINDS WILL GRADUALLY EASE BY LATE
FRIDAY NIGHT BUT WAVES WILL REMAIN REMAIN ELEVATED INTO SATURDAY
MORNING. ALL SMALL CRAFT ADVISORIES THEREFORE REMAIN IN EFFECT FOR
SAGINAW BAY AND THE NEARSHORE FROM PORT AUSTIN TO HARBOR BEACH UNTIL
SATURDAY MORNING. A RENEWED SURGE OF GUSTY WINDS WILL DEVELOP AHEAD
OF ANOTHER PUSH OF COLD AIR ON SATURDAY. A BRIEF REPRIEVE CAN BE
EXPECTED ON SUNDAY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE
AREA...BUT UNSETTLED CONDITIONS WILL QUICKLY REDEVELOP AS THE
SURFACE PRESSURE GRADIENT STRENGTHENS EARLY NEXT WEEK. SOUTH WINDS
WILL INCREASE TO 20 TO 25 KNOTS BY LATE MONDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
PORT AUSTIN TO HARBOR BEACH...UNTIL 8 AM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DG
SHORT TERM...JVC
LONG TERM....DG
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
356 AM EDT FRI OCT 5 2012
.SHORT TERM...TODAY AND TONIGHT
NOW THAT THE SURFACE COLD FRONT HAS CLEARED THE AREA, MODERATE COLD
ADVECTION HAS BEGUN AND IS FORECAST TO CONTINUE WITH 850MB
TEMPERATURES FALLING TO SLIGHTLY BELOW ZERO BY 06Z TONIGHT. THE MOST
NOTEWORTHY CHANGE MADE TO TODAY`S FORECAST PACKAGE WAS TO TREND
TODAY`S HIGH TEMPERATURES DOWNWARD A COUPLE OF DEGREES. ALL
LOCATIONS STAND A GOOD CHANCE TO REMAIN IN THE 50S FOR THE BALANCE
OF THE DAY AS EARLY OCTOBER DIURNAL HEATING WILL HAVE TO CONTEND
WITH NOT ONLY WITH ONGOING COLD ADVECTION, BUT ALSO WIDESPREAD MID
AND UPPER CLOUDS. IN ADDITION, UPSTREAM LOCATIONS THAT SPENT THE
DAYTIME HOURS THURSDAY IN THE POST-FRONTAL ENVIRONMENT GENERALLY
ROSE INTO THE LOW 50S. AFTER GIVING CONSIDERATION TO THE HEAT
CONTRIBUTION FROM LAKE MICHIGAN, WHERE LAKE SFC TEMPS REMAIN IN THE
LOW 60S, HIGHS FOR TODAY WERE GIVEN A DOWNWARD ADJUSTMENT INTO THE
55-58 DEGREE RANGE. A FEW 60S STILL CAN`T BE RULED OUT SHOULD CLOUDS
BREAK DURING PEAK HEATING, MOST LIKELY NORTH OF M-59.
THE OTHER FORECAST ISSUE FOR TODAY IS THE PLACEMENT AND DURATION OF
A BAND OF SHOWERS THAT IS CURRENTLY TAKING SHAPE OVER MO/IL. WATER
VAPOR IMAGERY SHOWS AN ENERGETIC ZONAL FLOW ACROSS THE CENTRAL U.S.
WITH EMBEDDED LOW AMPLITUDE SHORTWAVES PROPAGATING ACROSS THE PLAINS
STATES. SHOWER COVERAGE IS EXPANDING AHEAD OF THIS ENERGY AND IN
ASSOCIATION WITH A DEVELOPING FGEN RESPONSE UNDER THE RIGHT ENTRANCE
OF A STRENGTHENING 90KT JET STREAK. THE 00Z GUIDANCE, IN PARTICULAR
THE NAM AND RECENT 3-KM HRRR SIMULATIONS, LOOK SOLID IN THEIR
REPRESENTATION OF THE DEVELOPING FRONTAL CIRCULATION AND ASSOCIATED
PRECIPITATION COVERAGE. FOR NOW, THE ONLY COMPLAINT IS THAT THE
RESPONSE WITHIN THE LOW STATIC STABILITY ENVIRONMENT LEADING THE
ARRIVAL OF THE JET CORE LOOKS HEALTHY, SO LEANED TOWARD AN EARLIER
12-13Z ARRIVAL TIME FOR SOUTHERN AREAS. THE NORTH SIDE OF THE PRECIP
SHIELD WILL INITIALLY CARRY THE SHARP CUTOFF EVIDENT ON THE REGIONAL
RADAR MOSAIC INTO THE AREA, CASTING SOME UNCERTAINTY ON ITS
NORTHWARD EXTENT AS IT STRADDLES THE METRO DETROIT AREA INTO THE
AFTERNOON. HOWEVER, ADDITIONAL NORTHWARD EXPANSION SEEMS PROBABLE
THIS AFTERNOON AS THE POTENT SHORTWAVE ENERGY OVER ID/WY AT 07Z
ACCELERATES TOWARD THE AREA LATER TODAY. LAKE CLOUDS WILL THEN BUILD
INTO THE AREA LATE TONIGHT COINCIDENT WITH THE APPROACH OF THE UPPER
TROUGH AXIS AND H85-SFC DELTA T VALUES PLUMMETING TO 20C OVER LM.
THE STAGE WILL THEN BE SET FOR A COLD START TO SATURDAY MORNING AS
LOW TEMPS DIP INTO THE MID TO UPPER 30S UNDERNEATH INCREASING
BOUNDARY LAYER SKY COVER.
&&
.LONG TERM...SATURDAY THROUGH THURSDAY
AS UPPER LOW SHIFTS JUST NORTH OF LAKE SUPERIOR IS PULLED NORTHEAST
INTO BROADER HUDSON BAY VORTEX...UPPER TROUGH AXIS WILL SWING ACROSS
LOWER MICHIGAN AND BRING A SECOND SHOT OF COLD AIR INTO THE AREA ON
SATURDAY. WITH H85 TEMPERATURES FALLING SOLIDLY BELOW 0C...EXPECT
HIGH TEMPERATURES TO REMAIN BETWEEN 50 AND 55. WHILE BEST LIFT AND
FORCING WITH THE VORTICITY CENTER ALONG THIS TROUGH WILL REMAIN TO
THE NORTH OF THE AREA...THERE WILL BE A SMALL CHANCE OF SHOWERS IN
THE 20-30% RANGE AS WRAPAROUND MOISTURE BRUSHES THE AREA AND LAKE
EFFECT ACTIVITY BEGINS TO EXPAND IN THE COLDER AIR.
AFTER ANOTHER DAY WITH HIGH TEMPERATURES AOB 55F ON SUNDAY (WITH
EARLY MORNING TEMPERATURES MOST LIKELY REACHING FREEZING IN SOME
LOCATIONS)...THE NEXT STRONG SHORTWAVE PIVOTING THROUGH THE NORTHERN
GREAT LAKES AROUND THE HUDSON VORTEX WILL BRING A MODERATING TREND
IN THE MONDAY AND TUESDAY TIME FRAME AS SOUTHWEST FLOW BECOMES
ESTABLISHED IN ADVANCE OF THE NEXT STRONG COLD FRONT WHICH WILL
SHIFT INTO THE AREA AS THIS SECOND NORTHERN STREAM STORM SYSTEM
WRAPS NORTHEAST INTO THE AFOREMENTIONED VORTEX. TEMPERATURES WILL
CLIMB WELL INTO THE 50S ON MONDAY AND TO 60 OR BETTER ON TUESDAY AS
THE ARRIVAL OF THIS COLD FRONT IS DELAYED SLIGHTLY AS LOW PRESSURE
RIPPLES UP ALONG IT.
THIS SOUTHERN STREAM LOW PRESSURE WILL BRING THE BEST CHANCE OF
RAINFALL IN THE EXTENDED PORTION OF THE FORECAST AS STRONG FORCING
SHIFTS THROUGH THE AREA WITH THIS PASSAGE OF THIS SYSTEM TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING...WITH ONLY MINOR LAKE EFFECT
ACTIVITY EXPECTED LATER WEDNESDAY INTO THURSDAY SOUTHEAST OF LAKE
HURON.
TEMPERATURES WILL COOL BACK INTO THE MID 50S ON WEDNESDAY...BUT WITH
NORTHERN STREAM SHORTWAVE TAKING A WESTERLY TRACK NORTH OF THE GREAT
LAKES...THE COLDEST AIR WITH THIS SYSTEM WILL REMAIN OVER CANADA AND
EXPECT TEMPERATURES TO REBOUND TO THE UPPER 50S TO AROUND 60 BY
THURSDAY.
&&
.MARINE...
A FRESH WEST-SOUTHWEST BREEZE WILL GUST INTO THE 25 TO 30 KNOT RANGE
TODAY AS A COOL AND UNSTABLE AIRMASS OVERSPREADS AREA WATERS. A FEW
GUSTS TO LOW END GALE FORCE WILL BE POSSIBLE FROM OUTER SAGINAW BAY
INTO CENTRAL LAKE HURON THIS AFTERNOON...BUT NO ORGANIZED OR
WIDESPREAD GALES ARE EXPECTED. WINDS WILL GRADUALLY EASE BY LATE
FRIDAY NIGHT BUT WAVES WILL REMAIN REMAIN ELEVATED INTO SATURDAY
MORNING. ALL SMALL CRAFT ADVISORIES THEREFORE REMAIN IN EFFECT FOR
SAGINAW BAY AND THE NEARSHORE FROM PORT AUSTIN TO HARBOR BEACH UNTIL
SATURDAY MORNING. A RENEWED SURGE OF GUSTY WINDS WILL DEVELOP AHEAD
OF ANOTHER PUSH OF COLD AIR ON SATURDAY. A BRIEF REPRIEVE CAN BE
EXPECTED ON SUNDAY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE
AREA...BUT UNSETTLED CONDITIONS WILL QUICKLY REDEVELOP AS THE
SURFACE PRESSURE GRADIENT STRENGTHENS EARLY NEXT WEEK. SOUTH WINDS
WILL INCREASE TO 20 TO 25 KNOTS BY LATE MONDAY.
&&
.AVIATION...ISSUED 1235 AM EDT FRI OCT 5 2012
//DISCUSSION...
COLD FRONTAL BOUNDARY RAPIDLY SHIFTING THROUGH THE AREA EARLY THIS
MORNING. SOME EVIDENCE OF LOWER MVFR CIGS IN LIGHT RAIN SHOWERS
NOW EMERGING ALONG THE FRONTAL SLOPE...BUT COVERAGE REMAINS TOO
SPOTTY TO DEFINE A SPECIFIC MENTION OF MVFR RESTRICTIONS LOCALLY
AT THIS POINT. BRIEF INCREASE IN WESTERLY WINDS IMMEDIATELY BEHIND
THE FRONT BEFORE EASING BACK INTO THE 10-12KT RANGE. INCREASING
MID LEVEL FORCING NORTH OF THIS FRONT WILL BRING A RENEWED CHANCE
FOR SHOWERS IN A LOWER CEILING ACROSS MAINLY THE DETROIT AREA BY
FRIDAY AFTERNOON.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILING INTERMITTENTLY FALLING 5000 FEET EARLY
THIS MORNING.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
PORT AUSTIN TO HARBOR BEACH...FROM 8 AM FRIDAY TO 8 AM
SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...JVC
LONG TERM....DG
MARINE.......JVC
AVIATION.....JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
141 AM EDT FRI OCT 5 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 423 PM EDT THU OCT 4 2012
WV LOOP AND RUC ANALYSIS SHOW NEGATIVE TILTED SHORTWAVE TROUGH OVER
NORTHERN MINNESOTA THIS AFTN WITH ASSOCIATED SFC LOW IN THE VCNTY OF
KINL. COLD FRONT IS IN PROCESS OF MAKING ITS WAY ACROSS UPR
MICHIGAN...BUT MUCH COLDER AIR IS LAGGING BEHIND OVER NORTHERN
MINNESOTA. HAVE SEEN ISOLD SHRA FORM THIS AFTN WITH EVEN TSRA. MAIN
AREA WAS ON KEWEENAW BUT JUST WITHIN LAST 1 HR ANOTHER LINE OF SHRA
HAS FORMED OVER EASTERN LK SUPERIOR/FAR NORTHEAST CWA. DEEP DRYING
WRAPPING IN ON SOUTHERN EDGE OF SHORTWAVE TROUGH IS STEEPENING MID
LEVEL LAPSE RATES. MOST OF SHRA/TSRA KICKED ON WITHIN THE BETTER
LR/S AND ALSO ON LEADING EDGE OF H85 FRONTOGENESIS. OTHERWISE ONCE
PESKY FOG HELPED OUT BY MOISTURE OFF LK MICHIGAN BURNED OFF...IT HAS
BECOME NICE DAY WITH HIGHS TOPPING OUT IN THE 60S AND EVEN SOME
LOWER 70S. THAT WILL BE LAST 70 DEGREES FOR POSSIBLY THIS FALL
THOUGH AS BIG CHANGES ARE COMING IN ONCE THE LOW OVER MINNESOTA
MOVES TO NORTHERN LK SUPERIOR AND COLDER AIR PLOWS INTO THE REGION.
THROUGH FRIDAY...DO NOT EXPECT ANY BIG SNOW ACCUMS. WIDESPREAD SNOW
ON CYCLONIC SIDE OF SHORTWAVE TROUGH AND IN MOIST/CYCLONIC FLOW
BEHIND SFC LOW NEVER REALLY MAKES IT INTO CWA...INSTEAD LIFTING MORE
NORTHEAST INTO ONTARIO. INSTEAD...NORTHWEST CWA GRADUALLY GETS INTO
A REGIME WITH PLENTIFUL LOW-LEVEL MOISTURE BLO 10KFT AND WSW BLYR
WINDS TURNING MORE WESTERLY WITH TIME. SOUNDINGS INDICATE TEMPS IN
MOIST LAYER ARE WARMER THAN -8C UNTIL THE DAYTIME ON FRIDAY. UPSHOT
IS THAT INITIAL PRECIP TONIGHT INTO FRIDAY MORNING FOR NW CWA WILL
BE MAINLY LIGHT RAIN WITH PERHAPS REALLY SMALL SNOW FLAKES MIXING IN
AT TIMES LATER TONIGHT. AFTER EARLY EVENING POPS EAST...RESTRICTED
POPS FOR LAKE EFFECT/CYCLONIC FLOW MOISTURE TO KEWEENAW OVERNIGHT
TONIGHT AS REST OF AREA STAYS IN UNFAVORABLE WSW WINDS IN LOW-LEVELS.
WINDS IN BLYR LATE TONIGHT PUSH TOWARD 30 MPH SO EXPECT WINDS NW CWA
TO INCREASE LATE. SHOULD BE FAIRLY QUIET OVER REST OF CWA. SKIES MAY
EVEN CLEAR OUT SOME IN THE CNTRL AND EAST OVERNIGHT FOR A TIME.
A RATHER MISERABLE DAY IS IN STORE FOR KEWEENAW ON FRIDAY. SOUNDINGS
SHOW INCREASING DEPTH TO MOISTURE WITH MOISTURE PUSHING COLDER THAN
-10C BY AFTN SO SHOULD SEE MORE AND MORE SNOW MIX WITH RAIN THROUGH
THE DAY. BLYR TEMPS REMAIN WARM IN THE UPR 30S AND LOWER 40S...SO
EVEN IF PRECIP CHANGES TO MOSTLY SNOW DURING THE DAY /WOULD OCCUR
BASED ON WBZERO HEIGHTS FALLING WELL BLO 1000 FT AGL/ LITTLE OR NO
SNOW ACCUM SHOULD OCCUR DURING THE DAY. BEST CHANCE FOR SEEING SNOW
AS ONLY PTYPE WILL BE ON THE HIGHEST TERRAIN OF THE NW CWA. SIMILAR
TO TONIGHT...SHOULD BE PRETTY QUIET MOST OTHER AREAS ON FRIDAY
MORNING THOUGH A BIT BREEZY. BY FAR...STRONGEST WINDS WILL BE FOUND
ON THE KEWEENAW WITH FAVORED WESTERLY WINDS. MIXED LAYER WINDS
EASILY TOP OUT OVER 35 KTS AND TOP OF MIXED LAYER WINDS FROM
SOUNDINGS SUPPORT GUSTS PUSHING WELL OVER 40 KTS. WINDS ARE ALSO
STRONG ALONG LAKE SUPERIOR FROM IWD TO ONTONAGON. FAVORED WEST WIND
DIRECTION AND SUCH STRONG WINDS IN MIXED LAYER IN FACE OF STRONG
COLD AIR ADVECTION SUPPORTS FREQUENT GUSTS ON FRIDAY OVER HIGHER
TERRAIN OF KEWEENAW PENINSULA REACHING WIND ADVY LEVEL /39 KT OR 45
MPH/. WIND ADVY WAS ISSUED FOR KEWEENAW. FOR THOSE OTHER AREAS NEAR
LK SUPERIOR ADVY LEVEL WIND GUSTS SHOULD BE NOT AS FREQUENT...SO DID
NOT INCLUDE THOSE AREAS IN ADVY AT THIS TIME.
BY MID-LATE AFTN ON FRIDAY...925MB-850MB WINDS VEER MORE WNW WHICH
SHOULD BRING MORE OF CWA INTO CYCLONIC LOW-LEVEL MOIST FLOW. EXPECT
WX REGIME OVER KEWEENAW TO BEGIN TO SHIFT TOWARD HIGHER TERRAIN OF
ALL WESTERN AND POSSIBLE NCNTRL CWA BY 21Z. TEMPS MAY ALSO TRY TO
FALL OFF FOR THESE AREAS AS WELL. AGAIN...LIKE THE KEWEENAW EVEN
WITH MAINLY SNOW VERSUS RAIN...WARMER BLYR TEMPS AND MINIMAL
STRONGER LAKE EFFECT CONVECTION SHOULD PROHIBIT MUCH IN WAY OF SNOW
ACCUM. BETTER CHANCE FOR SNOW ACCUMS FOR THE CWA WILL OCCUR MORE ON
FRIDAY NIGHT WHICH IS NOW ADDRESSED IN THE LONGER TERM DISCUSSION.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 PM EDT THU OCT 4 2012
NAM SHOWS A BROAD 500 MB TROUGH ACROSS THE CENTRAL U.S. WITH A RIDGE
OFF THE PACIFIC NW AND A CLOSED LOW OFF THE CA COAST IN A REX BLOCK
PATTERN WITH A RIDGE OFF THE EAST COAST 00Z SAT. PATTERN DOES NOT
CHANGE MUCH WITH A SHORTWAVE OVER THE NORTHERN PLAINS ROTATING
AROUND THE TROUGH AND INTO THE LOWER GREAT LAKES ON SUNDAY.
BASICALLY...WILL NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.
SINCE THIS IS AN EARLY SEASON SNOW...LOT OF THE TOOLS WILL NOT WORK
USING THICKNESSES FOR DETERMINING SNOW AND PRETTY MUCH KEPT WHAT WAS
ALREADY IN THERE WHICH IS SNOW IN THE HIGHER TERRAIN AND RAIN IN THE
LOWER TERRAIN AND EASTERN CWA. DID LOWER SNOW RATIOS THOUGH AS
FEELING IS THAT THE SNOW FLAKE SIZE WILL BE SMALL AND LOWER THAN A
10 TO 1 RATIO WILL WORK. THIS STILL GIVES ME 1-3 INCHES IN THE
HIGHER TERRAIN FOR FRI NIGHT THROUGH SAT EVENING. IT WILL BE COLD
ENOUGH FOR LAKE EFFECT PCPN AND LOWERED THE LAKE TEMPERATURES TO 10C
TO 12C FOR FRI NIGHT AND SAT AS THINKING IS THE LAKE WILL START TO
GET TURNED OVER AND WATER TEMPERATURES WILL COOL OFF FROM 12C TO 15C
THAT IT IS NOW. 850 MB TEMPERATURES COOL TO AROUND -6C BY 12Z SAT
AND THAT IS ENOUGH LAKE EFFECT DELTA-T FOR LAKE EFFECT. BY
SUNDAY...WINDS SWITCH TO THE SW AND WITH WARM AIR ADVECTION COMING
IN...THIS WILL PUSH THE LAKE EFFECT PCPN OFFSHORE OF THE U.P.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH ACROSS
THE CENTRAL AND EASTERN U.S. WITH A RIDGE OFF THE PACIFIC NW AND A
CLOSED LOW OFF THE CA COAST IN A REX BLOCK PATTERN 12Z MONDAY. THERE
IS A SHORTWAVE ACROSS SOUTH CENTRAL CANADA THAT IS POISED TO DROP
INTO THE UPPER GREAT LAKES WITH AN ALBERTA CLIPPER SYSTEM THAT MOVES
THROUGH MON NIGHT INTO TUE. THE TROUGH OVER THE CENTRAL AND EASTERN
U.S. STAYS ANCHORED OVER THE UPPER GREAT LAKES INTO WED. ANOTHER
CLIPPER TYPE SYSTEM LOOKS TO AFFECT THE AREA ON THU. IT LOOKS TO
STAY COLDER THAN NORMAL THROUGH THE EXTENDED PERIOD WITH ACTIVE
WEATHER. KEPT MIXTURE OF RAIN AND SNOW IN FOR LATE TUE NIGHT INTO
WED MORNING WITH NEXT COLD AIR WAVE THAT COMES THROUGH. DID NOT MAKE
TOO MANY CHANGES TO THE GOING FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 139 AM EDT FRI OCT 5 2012
UPPER MI WILL BE UNDER THE CIRCULATION OF A LOW PRES SYSTEM MOVING
ACROSS NRN ONTARIO TODAY. INITIALLY...CONDITIONS WILL BE VFR AT
KIWD/KCMX/KSAW...BUT AS COLDER AIR INCREASES OVERLAKE INSTABILITY
AND MOISTURE WRAPS AROUND THE LOW INTO THE AREA...EXPECT CIGS TO BE
MVFR AT KCMX BY FCST ISSUANCE TIME AND AT KIWD BEFORE DAYBREAK. THE
COLDER AIR WILL ALSO LEAD TO LAKE ENHANCED RAIN/SNOW/IFR CONDITIONS
DEVELOPING AT KCMX EARLY THIS MORNING AND THEN CONTINUING THRU THE
DAY. WINDS SHOULD VEER ENOUGH TO BRING LAKE EFFECT PCPN INTO KIWD
THIS AFTN. SFC TROF DROPPING ACROSS THE LAKE LATER THIS AFTN/EVENING
SHOULD BRING HEAVIER -SHSN/IFR CONDITIONS TO KIWD THIS EVENING.
MEANWHILE...AFTER TROF PASSES...CONDITIONS SHOULD IMPROVE TO MVFR AT
KCMX. AT KSAW...W DOWNSLOPING WINDS THRU THE PERIOD SHOULD RESULT IN
VFR CONDITIONS PREVAILING WITH NO PCPN. SFC TROF/-SHSN SHOULD REACH
KSAW AROUND THE END OF THIS FCST PERIOD. WITH A TIGHT PRES
GRADIENT...WINDS WILL BE STRONG WITH GUSTS AOA 30KT THRU TODAY.
STRONGEST WINDS...GUSTING TO 40KT OR SO...WILL BE AT KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT THU OCT 4 2012
AN INTENSIFYING LOW PRESSURE SYSTEM WILL MOVE NORTH-NORTHEAST FROM
CENTRAL MINNESOTA TO THE U.S./CANADIAN BORDER BY THIS
AFTERNOON...BEFORE BEING LOCATED JUST NORTH NORTHWEST OF LAKE
SUPERIOR BY LATE TONIGHT. THIS WILL LEAD TO INCREASING SOUTHWESTERLY
WINDS ACROSS THE LAKE THIS AFTERNOON WITH GALE FORCE GUSTS OF
35-45KTS EXPECTED OVER MAINLY WRN LAKE SUPERIOR THIS
AFTERNOON/EVENING...INCREASING TO 45KTS TONIGHT INTO EARLY FRIDAY.
THE LOW WILL SHIFT NORTHEAST ON FRIDAY...BUT WILL KEEP A SFC TROUGH
OVER LAKE SUPERIOR THROUGH FRIDAY NIGHT. AS THIS SFC TROUGH SLOWLY
SLIDES SE ACROSS LAKE SUPERIOR...EXPECT WINDS TO SHIFT TO THE
NORTHWEST AND GUSTS UP TO 35KTS AT TIMES. A HIGH PRESSURE RIDGE WILL
BUILD OVER THE UPPER GREAT LAKES REGION ON SATURDAY AND
SUNDAY...LOWERING WINDS BELOW 25KTS. WINDS COME UP TO 30 KNOTS FOR
MON NIGHT AND TUE WITH NEXT CLIPPER TYPE SYSTEM BRINGING IN SOME
COLDER AIR. GETS REAL CLOSE TO A GALE THEN WITH A TIGHTER PRESSURE
GRADIENT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING FROM 6 AM THIS MORNING TO 10 AM EDT SATURDAY FOR
LSZ267.
GALE WARNING UNTIL 10 AM EDT SATURDAY FOR LSZ264>266.
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
240>247.
GALE WARNING UNTIL 6 AM EDT SATURDAY FOR LSZ263.
GALE WARNING FROM 6 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR
LSZ248.
LAKE MICHIGAN...
GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...ROLFSON
MARINE...07
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1200 AM EDT FRI OCT 5 2012
.SYNOPSIS...
ISSUED AT 354 PM EDT THU OCT 4 2012
A STRONG COLD FRONT WILL CROSS THE AREA THIS EVENING WITH SHOWERS
AND SCATTERED THUNDERSTORMS. SKIES WILL CLEAR LATE TONIGHT AND IT
WILL TURN COLDER. EXPECT MOSTLY SUNNY SKIES FRIDAY WITH HIGHS ONLY
IN THE 50S. LAKE EFFECT RAIN SHOWERS ARE EXPECTED SATURDAY INTO
SUNDAY WITH HIGHS MOSTLY IN THE 4OS.
&&
.UPDATE...
ISSUED AT 805 PM EDT THU OCT 4 2012
WE HAVE ISSUED AN UPDATE THIS EVENING TO FRESHEN UP THE FCST BASED
ON CURRENT TRENDS. THE TREND IS FOR THE RAIN TO MOVE THROUGH A
LITTLE QUICKER THAN PREVIOUSLY EXPECTED...ESPECIALLY UP NORTH WHERE THE
RAIN IS LIKELY DONE FOR THIS PORTION OF THE EVENT.
RAIN IS STILL MOVING INTO THE SRN PORTIONS OF THE AREA AS THE
FRONT PRESSES EAST. THERE HAS BEEN A COUPLE OF LIGHTNING STRIKES
OBSERVED...SO WE WILL CONTINUE THE ISOLATED MENTION OF THUNDER.
THE SRN PORTION OF THE CWFA WILL SEE RAIN HOLD OVER A LITTLE
LONGER AS ANOTHER WAVE OF RAINFALL COMING IN FROM THE SW WILL TAKE
A FEW HOURS TO PASS BY THE AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 354 PM EDT THU OCT 4 2012
THE MAIN ISSUE IS THE CONVECTIVE LINE OVER WISCONSIN HEADING
TOWARD SOUTHWEST LOWER MICHIGAN AS I WRITE THIS. BEYOND THAT THERE
IS THE ISSUE OF LAKE EFFECT RAIN SHOWERS OVER THE WEEKEND.
THE COMBINATION OF JET ASSISTED LIFT AND A DEVELOPING LOW LEVEL
JET WILL AID THE DEVELOPMENT OF A LINE OF SHOWERS THAT AT 3 PM WAS
OVER EASTERN WISCONSIN. AS THIS LINE CROSSES LAKE MICHIGAN I
EXPECT THUNDERSTORMS TO DEVELOP WITHIN THAT LINE. AIDING THAT IS
A SURGE OF HIGHER SURFACE DEW POINTS JUST AHEAD OF THE COLD FRONT.
THE 1000 TO 850 MB MOISTURE TRANSPORT VECTORS INCREASE SIGNIFICANTLY
AS THE FRONT CROSSES LAKE MICHIGAN. THE HRRR RUC IS DOING REASONABLY
WELL WITH THE CONVECTION ON THE COLD FRONT SO FAR THIS AFTERNOON.
SO...BASED ON OUR TIMING TOOL...THE TIMING IN THE HRRR RUC AND RELATED
TOOLS I EXPECT A NEARLY SOLID LINE OF SHOWERS AND ISOLATED STORMS
TO CROSS THE CWA BETWEEN 6 PM AND 11 PM THIS EVENING. I DO NOT
EXPECT SEVERE STORMS AS THE CAPES ARE NOT IMPRESSIVE BUT THERE IS
30 - 40 KNOTS OF DEEP LAYER SHEAR TO WORK WITH. THERE IS ALSO 40
TO 50 KNOTS AS CLOSE TO THE GROUND AS 5000 FT AGL AS THIS LINE
MOVES CROSS THE CWA. SO EXPECT GUSTY WINDS WITH THE SHOWERS.
ONCE THIS FEATURE MOVES EAST THE STRONG COLD ADVECTION BEHIND THE
FRONT WILL RESULT IN CONSIDERABLE SUBSIDENCE SO EXPECT CLEARING
SKIES LATER TONIGHT.
ANOTHER JET SEGMENT ROTATING THROUGH THE UPPER TROUGH WILL INDUCE
A WAVE ON THE FRONT FRIDAY INTO SATURDAY. AT THIS POINT IT SEEMS
THE RAIN FROM THAT WILL MOSTLY STAY SOUTH OF THE CWA. IT COULD
IMPACT AREAS SOUTH OF I-69 FRIDAY INTO FRIDAY EVENING EVEN SO. I
HAVE LOW CHANCE POPS FOR THAT.
THE SHORTWAVE TROUGH WITH THE DEEP COLD AIR ROTATES THROUGH THE
CWA SATURDAY. THAT WILL RESULT IN LAKE EFFECT RAIN SHOWERS. THANKS
TO A NORTH NORTHWEST WIND IN THE BOUNDARY LAYER I EXPECT MOST OF
THE SIGNIFICANT SHOWERS TO BE CLOSE TO LAKE SHORE. EVEN SO THE AIR
IS UNSTABLE ENOUGH THAT ALL AREAS SHOULD SEE SOME SHOWERS IN THE
AFTERNOON. SATURDAY NIGHT THOSE SHOWERS WILL CONTINUE NEAR THE
LAKE SHORE BUT SOME CLEARING IS POSSIBLE INLAND. COLD BE A FREEZE
EARLY SUNDAY MORNING NORTH AND EAST OF GRR. WE WILL HAVE TO WATCH
THAT FOR A POSSIBLE FREEZE WARNING.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 354 PM EDT THU OCT 4 2012
STILL EXPECTING SOME WEAK LAKE EFFECT RAIN SHOWERS INTO SUNDAY...
HOWEVER SURFACE RIDGING SHOULD BE BREAKING MUCH OF IT UP THROUGH THE
DAY. FROST POTENTIAL LOOKS RATHER GOOD INTO SUNDAY NIGHT AS SKIES
CLEAR. WE WILL HAVE TO SEE HOW MUCH MIXING REMAINS OVER THE
REGION...WHICH COULD LESSEN THE IMPACTS.
THE NEXT RAIN MAKER WILL COME IN THE FORM OF ANOTHER COLD FRONT
EXPECTED LATE TUESDAY INTO WEDNESDAY. COULD BE POCKETS OF STEADIER
RAINS AS THIS FRONT LOOKS MUCH LIKE THIS EVENING/S FRONT. HAVE LEFT
THUNDER OUT HOWEVER AS THE TIMING OF THE FROPA SHOULD BE LATE
TUESDAY NIGHT.
THE CHILLY AIR WILL SLOWLY LOSE IT/S GRIP ON THE REGION INTO EARLY
NEXT WEEK. H8 TEMPS BELOW 0C MOVE EAST OF THE AREA BY MONDAY
AFTERNOON SO A SLIGHTLY WARMING TREND IS EXPECTED WITH UPPER 50S AND
LOWER 60S FOR MONDAY AND TUESDAY. ANOTHER SHOT OF COOLER AIR IS
EXPECTED BEHIND THE TUESDAY NIGHT FRONT...HOWEVER THIS LOOKS TO BE A
QUICKER SHOT...WITH H8 TEMPS ALREADY WARMING BY THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1200 PM EDT FRI OCT 5 2012
EXPECT MOSTLY VFR TONIGHT ALTHOUGH SOME SHOWERS WILL BRING PATCHY
MVFR THROUGH 09Z ESPECIALLY AT AZO AND BTL. SOUTHWEST WINDS WILL
GUST TO NEAR 20 KNOTS AT TIMES BEFORE DECREASING LATE TONIGHT.
&&
.MARINE...
ISSUED AT 354 PM EDT THU OCT 4 2012
I EXTENDED THE SMALL CRAFT ADVISORY INTO SATURDAY NIGHT SINCE WAVE
HEIGHTS ARE NOT EXPECTED TO SUBSIDE BELOW 4 FEET UNTIL EARLY
SUNDAY MORNING. THE EXPERIMENTAL GREAT LAKES WATER SPOUT FORECAST
SHOWS THE BEST SHOT OF WATER SPOUTS AS BEING SATURDAY AS THE DEEPER
COLD AIR MOVES IN. I PUT WATER SPOUTS IN THE NEAR SHORE DURING
THAT TIME.
THE HRRR SUGGEST POSSIBLE NEAR GALE WINDS WITH THE FRONT THIS
EVENING THAT WILL HAVE TO BE WATCHED TOO.
&&
.HYDROLOGY...
ISSUED AT 354 PM EDT THU OCT 4 2012
RAINFALL WILL BE LIMITED AT BEST OVER THE NEXT WEEK SO EVEN WITH
THE RAINS LAST NIGHT I DO NOT SEE ANY SIGNIFICANT FLOODING ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...NJJ
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS BILLINGS MT
312 PM MDT FRI OCT 5 2012
.SHORT TERM...VALID FOR SAT AND SUN...
THE MID-LEVEL SHORT WAVE TROUGH APPROACHING FROM THE NORTH AS OF
20 UTC TODAY WILL BE THE LAST IN THE RECENT SERIES OF WAVES THAT
HAVE AFFECTED US IN NORTH-NORTHWEST FLOW ALOFT. HOWEVER...BEFORE
WE BEGIN A SLOW WARMING TREND AS THE MEAN 500-HPA TROUGH THAT IS
BEING FED BY THESE WAVES HEADS EAST ON SAT...WE WILL DEAL WITH A
UPSLOPE-ASSISTED SNOW EVENT IN PARTS OF THE AREA TONIGHT.
TONIGHT...THE 12 UTC GFS AND NAM AND SEVERAL RECENT HRRR AND RAP
SOLUTIONS ALL INCREASED QPF AMOUNTS FROM FAR SOUTH CENTRAL MT TO
SHERIDAN COUNTY WY. THIS IS BASED ON 1/ UPSLOPE FLOW WHICH LASTS
LONGER THAN EARLIER EXPECTED WITH A BIT SLOWER WAVE TIMING...AND
2/ A MODEST BUT DEFINED AREA OF MID-LEVEL FRONTOGENESIS NEAR THE
700 HPA LAYER THAT ASSISTS IN DEEPER VERTICAL MOTION ACROSS PART
OF NORTH CENTRAL WY. SUBSTANTIAL 500-300 Q-VECTOR CONVERGENCE...
AND STEEP MID-LEVEL LAPSE RATES...IS YIELDING CONVECTIVE SHOWERS
OVER MUCH OF THE AREA ALREADY...AND THOSE ELEMENTS WILL HELP OUT
THE POTENTIAL FOR SNOW CENTERED OVER SHERIDAN COUNTY AS WELL. IT
LOOKS LIKE THE DENDRITIC LAYER WILL ALSO BE SATURATED AND HAVE A
DECENT AREA OF OMEGA IN IT OVER NORTH CENTRAL WY...WHICH FURTHER
SOLIDIFIED OUR DECISION TO ISSUE A WINTER WEATHER ADVISORY UNTIL
12 UTC SAT FOR THE SHERIDAN FOOTHILLS. INTERESTINGLY...THERE WAS
A STRONG SIGNAL FOR ACCUMULATING SNOW IN THE CITY OF SHERIDAN IN
THE 12 UTC MET MOS. WHILE WE FEEL SHERIDAN ITSELF WILL LIKELY BE
IN LINE FOR ONLY AN INCH OR TWO OF SNOW...IT IS A BIT RARE FOR A
4 INCH SNOW FORECAST TO SHOW UP IN THE MOS FOR SHERIDAN...SO THE
SITUATION DOES WARRANT CLOSE MONITORING. AT THE VERY LEAST...THE
STORY AREA AND OTHER FOOTHILLS LOCATIONS LOOK IN LINE TO GET 2-4
INCHES OF SNOW...ESPECIALLY IF FORCING ALOFT LINGERS PAST 06 UTC
LIKE THE 12 UTC NAM SUGGESTS. WE ALSO HAVE LIKELY POPS FOR AREAS
LIKE FISHTAIL AND RED LODGE THIS EVENING...BUT IT SEEMS LIKE THE
QPF AND RESULTANT SNOW IN THOSE AREAS WILL BE LESS SINCE FORCING
ALOFT WILL BE LESS ROBUST THERE.
FINALLY...WE STILL EXPECT A WIDESPREAD HARD FREEZE TONIGHT...BUT
WE ARE ALSO STILL GOING A BIT WARMER THAN PURE MOS-BASED NUMBERS
WITH OUR FORECAST LOWS. THAT/S OUT OF RESPECT TO POTENTIAL FOR A
SLOW DECREASE IN CLOUDS...MAINLY IN SOUTH CENTRAL MT. THE CLOUDS
HAVE CAUSED A COLD BIAS ON THE ORDER OF 10+ F TO MOS DURING THE
LAST TWO DAYS...SO WE ARE A BIT HESITANT TO RUN WITH IT...THOUGH
SURFACE DEWPOINTS HAVE FINALLY FALLEN ENOUGH FOR LOWS BELOW 30 F
IN MOST AREAS TONIGHT.
SAT...MODEST MID-LEVEL WARM AIR ADVECTION WILL BEGIN...AND SO WE
WILL BEGIN A WARMING TREND. THE 12 UTC MOS GUIDANCE ALL RESPONDS
TO THIS WARMING ALOFT BY SHOWING HIGHS WELL INTO THE 40S F. WARM
AIR ADVECTION ALOFT AND RELATIVELY WEAK /ALBEIT DOWNSLOPE/ WINDS
IN THE LOW LEVELS ARE NOT VERY FAVORABLE FOR WARMING THOUGH...SO
WE WERE CAUTIOUS IN GOING TOO MUCH WARMER THAN MOS AT THIS TIME.
SUN...MORE AGGRESSIVE WARMING ALOFT IS EXPECTED AS A SURFACE LOW
HEADS EAST ACROSS SOUTHERN CANADA DURING THE DAY. THE 12 UTC GFS
IS A BIT WARMER THAN THE REST OF THE GUIDANCE ALOFT WITH 850-HPA
TEMPERATURES UP TO +13 C AT BILLINGS BY AFTERNOON...BUT WITH THE
DOWNSLOPE FLOW IN THE BOUNDARY LAYER AND A BIT OF BACKING TO THE
FLOW ALOFT...THE WARMER SOLUTION IS PROBABLY A GOOD ONE. WE FEEL
THAT MIXING WILL BE MORE EFFICIENT AS WELL WITH MORE FLOW IN THE
SURFACE TO 2 KM AGL LAYER...SO WE BASED HIGHS MORE OFF OF MIXING
DEPTHS THAN MOS...WHICH MEANT RAISING THEM JUST A BIT. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
EXTENDED MODELS IN FAIRLY GOOD AGREEMENT THROUGH THE MIDDLE OF
NEXT WEEK THEN DIVERGE QUITE A BIT BY LATE WEDNESDAY. OVERALL A
STRAIGHT NORTH TO NORTHWEST FLOW ALOFT WILL BE OVER THE FORECAST
AREA MONDAY AND TUESDAY. A WEAK FRONT IS PROGGED TO MOVE SOUTH
ACROSS THE AREA LATE IN THE DAY MONDAY INTO MONDAY NIGHT WHICH
WILL BRING A SLIGHT CHANCE FOR A RAIN OR SNOW SHOWER.
HOWEVER...NOT MUCH IN THE WAY OF MOISTURE WITH THIS DISTURBANCE SO
ANY SHOWER ACTIVITY IS EXPECTED TO BE LIGHT. BELOW NORMAL
TEMPERATURES CAN BE EXPECTED MONDAY INTO TUESDAY WITH HIGHS MAINLY
IN THE 50S. MODELS BEGIN TO DIVERGE LATE WEDNESDAY AS THE ECMWF
STARTS TO TURN THE NORTHWEST FLOW MORE ZONAL THEN BEGIN TO BUILD A
RIDGE THURSDAY INTO FRIDAY. HOWEVER...THE 12Z GFS NOW BRINGS
ANOTHER COLD FRONT SOUTH LATE WEDNESDAY NIGHT INTO
THURSDAY...WHEREAS...THE PREVIOUS RUN BEGAN TO BUILD A RIDGE. WILL
NOT MAKE ANY SIGNIFICANT CHANGES WITH THIS PACKAGE AND SEE WHAT
THE NEXT MODEL RUN LOOKS LIKE. AS THINGS STAND NOW...DRY
CONDITIONS CAN BE EXPECTED WEDNESDAY THROUGH FRIDAY WITH
TEMPERATURES WARMING BACK TO AROUND SEASONAL LEVELS. HOOLEY
&&
.AVIATION...
SCATTERED SNOW SHOWERS WILL BE POSSIBLE ACROSS THE ENTIRE
FORECAST AREA THROUGH MIDNIGHT RESULTING IN OCCASIONALL MVFR TO
IFR CONDITIONS. IN ADDITION...AREAS OF FOG WILL BE POSSIBLE ACROSS
THE PLAINS MAINLY WEST OF KMLS. OTHERWISE...VFR CONDITIONS WILL
PREVAIL ACROSS THE PLAINS. HOWEVER...MORE NUMEROUS AND HEAVIER
SNOW SHOWER ACTIVITY IS EXPECTED ACROSS THE BIG HORN AND PRYOR
MOUNTAINS...AS WELL AS THE FOOTHILLS AND LOWER ELEVATIONS OF
SHERIDAN COUNTY. MVFR TO IFR CONDITIONS ARE EXPECTED THROUGHOUT
THE NIGHT FOR THE EASTERN FOOTHILLS OF THE BIG HORN MOUNTAINS
EASTWARD ACROSS SHERIDAN COUNTY. ALL MOUNTAIN LOCATIONS WILL BE
OBSCURED THROUGHOUT THE NIGHT. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 024/045 033/063 038/056 037/054 036/061 038/056 039/062
41/U 00/U 01/B 22/W 00/U 00/U 11/U
LVM 019/045 022/059 030/057 026/053 030/062 032/059 033/058
31/U 10/U 01/B 22/W 01/B 11/U 11/U
HDN 026/052 028/063 038/059 037/054 036/063 035/061 036/064
41/U 10/U 01/B 22/W 00/U 00/U 01/U
MLS 022/049 030/062 041/056 036/053 035/061 037/054 037/061
21/U 10/B 12/W 21/B 00/U 00/U 01/U
4BQ 022/046 027/059 039/058 038/053 035/061 038/059 038/061
20/U 00/B 01/B 32/W 00/U 00/U 01/U
BHK 020/046 028/057 040/054 033/050 033/060 034/053 033/059
10/U 00/B 12/W 21/B 00/U 00/U 01/U
SHR 025/040 024/056 034/056 032/050 032/061 033/060 036/057
91/U 10/U 01/B 22/W 10/U 11/U 01/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MDT SATURDAY FOR
ZONE 99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
123 PM MDT FRI OCT 5 2012
.SHORT TERM...VALID FOR TDY AND SAT...
WE HAVE DECIDED TO ISSUE A WINTER WEATHER ADVISORY FROM 00 UTC TO
12 UTC FOR THE SHERIDAN FOOTHILLS FORECAST ZONE FOR 2 TO 4 INCHES
OF SNOW ACCUMULATION. THERE IS ENOUGH EVIDENCE IN THE 12 UTC RUNS
OF THE NAM AND GFS AND VARIOUS OTHER RECENT GUIDANCE TO HOIST THE
HEADLINE. MORE DETAILS ON THIS WILL FOLLOW WITH THE FULL FORECAST
DISCUSSION BY ABOUT 21 UTC. SCHULTZ
PREVIOUS DISCUSSION...ISSUED AT 1055 AM MDT FRI OCT 5 2012...
THE FORECAST WAS UPDATED TO INCREASE POPS A BIT TODAY ACROSS MUCH
OF THE AREA AS A 500-HPA SHORT WAVE TROUGH DROPS SOUTHWARD ACROSS
THE AREA. MID-LEVEL LAPSE RATES WILL STEEPEN THIS AFTERNOON WHILE
MID-LEVEL COLD AIR ADVECTION INCREASES WITH THE WAVE...WHICH WILL
BE SUFFICIENT FOR SCATTERED SHOWERS. THAT COVERAGE HAS SUPPORT ON
THE 12 UTC NAM AND GFS...AS WELL AS THE LAST FEW HRRR RUNS. A MIX
OF RAIN AND SNOW WAS MENTIONED EVEN AS SURFACE TEMPERATURES REACH
THE 40 F OR BETTER MARK IN PLACES SINCE THE WET BULB PROFILE WILL
STILL SUPPORT SNOW. THE TYPE OF SNOW SHOWERS EXPECTED TODAY OFTEN
YIELD TEMPORARY BUT SIGNIFICANT REDUCTIONS IN VISIBILITY. NOTE WE
ALSO EXTENDED AT LEAST SOME 20 TO 30 POPS INTO THIS EVENING BASED
ON THE LATEST TRENDS IN THE 12 UTC NAM AND GFS SOLUTIONS...WHICH
BOTH SHOW A BIT SLOWER TIMING TO THE SHORT WAVE ALOFT. IT APPEARS
THAT FORCING WITH THE WAVE MAY KEEP SOME SHOWERS AROUND BEYOND 00
UTC.
ALONG THE FOOTHILLS LIKE AT FISHTAIL AND RED LODGE SOUTHEAST INTO
THE BIG HORN RANGE AND SHERIDAN COUNTY WY...LOW-LEVEL FLOW HAS AN
UPSLOPE COMPONENT TO IT...AND THAT WILL CONTINUE THROUGH AT LEAST
06 UTC. ADD IN THE 500-300 HPA Q-VECTOR CONVERGENCE WITH THE WAVE
ALOFT AND THE SITUATION EASILY MERITS LIKELY POPS IN THESE PLACES
RIGHT INTO THE EVENING. ADVERTISED SNOW ACCUMULATIONS FALL MOSTLY
INTO THE 1 TO 3 INCH RANGE. HOWEVER...THERE IS A TREND WITHIN THE
12 UTC GUIDANCE FOR A DEEPER UPSLOPE WIND SIGNATURE WHICH LASTS A
COUPLE HOURS LONGER THAN EARLIER ANTICIPATED...SO WE WILL NEED TO
KEEP AN EYE ON THE POTENTIAL FOR A BIT MORE SNOW. OUR CONCERN FOR
GREATER SNOW ACCUMULATIONS WILL BE MAINLY IN SHERIDAN COUNTY WITH
THE 12 UTC NAM ESPECIALLY AGGRESSIVE WITH QPF TOWARD AND PAST THE
00 UTC HOUR ALL THE WAY UP INTO FAR SOUTH CENTRAL MT. MOISTURE IN
THE MODEL IS NON-CONVECTIVE...AND THUS APPEARS TIED TO AN AREA OF
WEAK MID-LEVEL FRONTOGENESIS. THE 12 UTC GFS NOW HAS KEYS ON THIS
AREA OF SLIGHTLY ENHANCED FRONTOGENESIS AS WELL...SO WE CHOSE TO
INCREASE POPS TO THE LIKELY THRESHOLD NOT ONLY OVER THE FOOTHILLS
OF THE BIG HORNS LIKE AT STORY...BUT EVEN AT SHERIDAN AND UP INTO
SOUTHERN BIG HORN COUNTY IN MT FOR THE EVENING HOURS. THIS RAISES
OUR CONCERN A BIT AGAIN FOR THE POSSIBILITY OF REQUIRING A WINTER
WEATHER ADVISORY CENTERED ON THIS EVENING IN AREAS LIKE STORY. WE
WILL CONTINUE TO EVALUATE THAT AS THE DAY WEARS ON. SCHULTZ
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
NORTHERLY FLOW WILL CONTINUE ACROSS THE REGION THROUGH THE MIDDLE
OF NEXT WEEK...WITH RIDGING MAKING A RETURN BY MAYBE NEXT
THURSDAY. THIS PATTERN WILL KEEP TEMPERATURES AT OR BELOW AVERAGE
AS WELL AS BRING OCCASIONAL DISTURBANCES KEEPING CONDITIONS
UNSETTLED.
MAINLY DRY CONDITIONS EXPECTED SUNDAY WITH TEMPERATURES IN THE 50S
TO NEAR 60 DEGREES AHEAD OF A SYSTEM ARRIVING LATE MONDAY.
TEMPERATURES MONDAY SHOULD MAKE IT INTO THE MID 50S BEFORE COOLER
AIR AND PRECIPITATION DROP SOUTHWARD INTO THE AREA LATE IN THE
DAY. PRECIPITATION CHANCES MONDAY NIGHT AND TUESDAY LOOK PRETTY
GOOD WITH STRONG QG FORCING DEVELOPING OVER THE AREA ALONG WITH
LOW LEVEL UPSLOPE FLOW. INCREASED POPS TO CHANCE CATEGORY FOR THIS
TIME FRAME. SYSTEM EXITS THE AREA EARLY WEDNESDAY WITH DRIER AIR
BUILDING IN...BUT STILL ENOUGH MOISTURE FOR A FEW MOUNTAIN SNOW
SHOWERS INTO WEDNESDAY NIGHT.
UPPER LOW OVER CALIFORNIA EARLY IN THE WEEK BEGINS TO TRANSIT TO
THE EAST MID WEEK HELPING TO DRIVE RIDGING NORTHWARD INTO THE AREA
BY THURSDAY. THIS MAY PUSH TEMPERATURES INTO THE MID TO UPPER 60S
THURSDAY AND FRIDAY...HOWEVER SOME MODELS SUGGESTING A GOOD DEAL
OF MOISTURE AND DECENT MID LEVEL FORCING WILL ACCOMPANY THIS
SOUTHERLY FLOW ALOFT RESULTING IN BETTER PRECIPITATION CHANCES
KEEPING TEMPERATURES DOWN. WILL CONTINUE TO WATCH THIS LATE WEEK
SYSTEM FOR POSSIBLE ADJUSTMENTS WITH LATER FORECASTS. CHAMBERS
&&
.AVIATION...
LOW LEVEL UPSLOPE WINDS COMBINED WITH RAIN AND SNOW SHOWERS WILL
RESULT IN MVFR TO LOCAL IFR CONDITIONS IN THE MOUNTAINS AND ALONG
THE FOOTHILLS THROUGHOUT THE DAY. ELSEWHERE...VFR TO LOCAL MVFR
CONDITIONS WILL PREVAIL WITH SCATTERED RAIN OR SNOW SHOWERS. THE
RAIN AND SNOW SHOWERS WILL DISSIPATE AROUND MID EVENING WITH LOCAL
AREAS OF FOG POSSIBLE LATE TONIGHT INTO SATURDAY MORNING. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 041 023/045 031/060 038/056 039/049 036/059 040/056
4/W 31/U 00/U 01/B 32/W 00/U 00/U
LVM 039 011/045 021/056 030/057 028/049 030/060 034/059
4/W 31/U 11/U 11/B 32/W 00/U 00/U
HDN 046 022/052 028/062 038/059 039/053 036/061 037/061
4/W 31/U 10/U 01/B 32/W 00/U 00/U
MLS 044 022/049 030/061 041/056 038/049 035/059 039/054
2/W 21/U 11/B 12/W 32/W 00/U 00/U
4BQ 044 021/049 026/059 039/058 040/049 035/059 040/059
3/W 20/U 00/B 01/B 33/W 00/U 00/U
BHK 043 020/049 028/057 040/054 035/046 033/058 036/052
2/W 00/U 00/B 12/W 32/W 00/U 00/U
SHR 040 020/044 024/056 034/056 034/046 032/059 035/060
6/W 61/U 10/U 00/U 33/W 00/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO 6
AM MDT SATURDAY FOR ZONE 99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1055 AM MDT FRI OCT 5 2012
.SHORT TERM...VALID FOR TDY AND SAT...
THE FORECAST WAS UPDATED TO INCREASE POPS A BIT TODAY ACROSS MUCH
OF THE AREA AS A 500-HPA SHORT WAVE TROUGH DROPS SOUTHWARD ACROSS
THE AREA. MID-LEVEL LAPSE RATES WILL STEEPEN THIS AFTERNOON WHILE
MID-LEVEL COLD AIR ADVECTION INCREASES WITH THE WAVE...WHICH WILL
BE SUFFICIENT FOR SCATTERED SHOWERS. THAT COVERAGE HAS SUPPORT OF
THE 12 UTC NAM AND GFS...AS WELL AS THE LAST FEW HRRR RUNS. A MIX
OF RAIN AND SNOW WAS MENTIONED EVEN AS SURFACE TEMPERATURES REACH
THE 40 F OR BETTER MARK IN PLACES SINCE THE WET BULB PROFILE WILL
STILL SUPPORT SNOW. THE TYPE OF SNOW SHOWERS EXPECTED TODAY OFTEN
YIELD TEMPORARY BUT SIGNIFICANT REDUCTIONS IN VISIBILITY. NOTE WE
ALSO EXTENDED AT LEAST SOME 20 TO 30 POPS INTO THIS EVENING BASED
ON THE LATEST TRENDS IN THE 12 UTC NAM AND GFS SOLUTIONS...WHICH
BOTH SHOW A BIT SLOWER TIMING TO THE SHORT WAVE ALOFT. IT APPEARS
THAT FORCING WITH THE WAVE MAY KEEP SOME SHOWERS AROUND BEYOND 00
UTC.
ALONG THE FOOTHILLS LIKE AT FISHTAIL AND RED LODGE SOUTHEAST INTO
THE BIG HORN RANGE AND SHERIDAN COUNTY WY...LOW-LEVEL FLOW HAS AN
UPSLOPE COMPONENT TO IT...AND THAT WILL CONTINUE THROUGH AT LEAST
06 UTC. ADD IN THE 500-300 HPA Q-VECTOR CONVERGENCE WITH THE WAVE
ALOFT AND THE SITUATION EASILY MERITS LIKELY POPS IN THESE PLACES
RIGHT INTO THE EVENING. ADVERTISED SNOW ACCUMULATIONS FALL MOSTLY
INTO THE 1 TO 3 INCH RANGE. HOWEVER...THERE IS A TREND WITHIN THE
12 UTC GUIDANCE FOR A DEEPER UPSLOPE WIND SIGNATURE WHICH LASTS A
COUPLE HOURS LONGER THAN EARLIER ANTICIPATED...SO WE WILL NEED TO
KEEP AN EYE ON THE POTENTIAL FOR A BIT MORE SNOW. OUR CONCERN FOR
GREATER SNOW ACCUMULATIONS WILL BE MAINLY IN SHERIDAN COUNTY WITH
THE 12 UTC NAM ESPECIALLY AGGRESSIVE WITH QPF TOWARD AND PAST THE
00 UTC HOUR ALL THE WAY UP INTO FAR SOUTH CENTRAL MT. MOISTURE IN
THE MODEL IS NON-CONVECTIVE...AND THUS APPEARS TIED TO AN AREA OF
WEAK MID-LEVEL FRONTOGENESIS. THE 12 UTC GFS NOW HAS EYES ON THIS
AREA OF SLIGHTLY ENHANCED FRONTOGENESIS AS WELL...SO WE CHOSE TO
INCREASE POPS TO THE LIKELY THRESHOLD NOT ONLY OVER THE FOOTHILLS
OF THE BIG HORNS LIKE AT STORY...BUT EVEN AT SHERIDAN AND UP INTO
SOUTHERN BIG HORN COUNTY IN MT FOR THE EVENING HOURS. THIS RAISES
OUR CONCERN A BIT AGAIN FOR THE POSSIBILITY OF REQUIRING A WINTER
WEATHER ADVISORY CENTERED ON THIS EVENING IN AREAS LIKE STORY. WE
WILL CONTINUE TO EVALUATE THAT AS THE DAY WEARS ON. SCHULTZ
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
NORTHERLY FLOW WILL CONTINUE ACROSS THE REGION THROUGH THE MIDDLE
OF NEXT WEEK...WITH RIDGING MAKING A RETURN BY MAYBE NEXT
THURSDAY. THIS PATTERN WILL KEEP TEMPERATURES AT OR BELOW AVERAGE
AS WELL AS BRING OCCASIONAL DISTURBANCES KEEPING CONDITIONS
UNSETTLED.
MAINLY DRY CONDITIONS EXPECTED SUNDAY WITH TEMPERATURES IN THE 50S
TO NEAR 60 DEGREES AHEAD OF A SYSTEM ARRIVING LATE MONDAY.
TEMPERATURES MONDAY SHOULD MAKE IT INTO THE MID 50S BEFORE COOLER
AIR AND PRECIPITATION DROP SOUTHWARD INTO THE AREA LATE IN THE
DAY. PRECIPITATION CHANCES MONDAY NIGHT AND TUESDAY LOOK PRETTY
GOOD WITH STRONG QG FORCING DEVELOPING OVER THE AREA ALONG WITH
LOW LEVEL UPSLOPE FLOW. INCREASED POPS TO CHANCE CATEGORY FOR THIS
TIME FRAME. SYSTEM EXITS THE AREA EARLY WEDNESDAY WITH DRIER AIR
BUILDING IN...BUT STILL ENOUGH MOISTURE FOR A FEW MOUNTAIN SNOW
SHOWERS INTO WEDNESDAY NIGHT.
UPPER LOW OVER CALIFORNIA EARLY IN THE WEEK BEGINS TO TRANSIT TO
THE EAST MID WEEK HELPING TO DRIVE RIDGING NORTHWARD INTO THE AREA
BY THURSDAY. THIS MAY PUSH TEMPERATURES INTO THE MID TO UPPER 60S
THURSDAY AND FRIDAY...HOWEVER SOME MODELS SUGGESTING A GOOD DEAL
OF MOISTURE AND DECENT MID LEVEL FORCING WILL ACCOMPANY THIS
SOUTHERLY FLOW ALOFT RESULTING IN BETTER PRECIPITATION CHANCES
KEEPING TEMPERATURES DOWN. WILL CONTINUE TO WATCH THIS LATE WEEK
SYSTEM FOR POSSIBLE ADJUSTMENTS WITH LATER FORECASTS. CHAMBERS
&&
.AVIATION...
LOW LEVEL UPSLOPE WINDS COMBINED WITH RAIN AND SNOW SHOWERS WILL
RESULT IN MVFR TO LOCAL IFR CONDITIONS IN THE MOUNTAINS AND ALONG
THE FOOTHILLS THROUGHOUT THE DAY. ELSEWHERE...VFR TO LOCAL MVFR
CONDITIONS WILL PREVAIL WITH SCATTERED RAIN OR SNOW SHOWERS. THE
RAIN AND SNOW SHOWERS WILL DISSIPATE AROUND MID EVENING WITH LOCAL
AREAS OF FOG POSSIBLE LATE TONIGHT INTO SATURDAY MORNING. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 041 023/045 031/060 038/056 039/049 036/059 040/056
4/W 31/U 00/U 01/B 32/W 00/U 00/U
LVM 039 011/045 021/056 030/057 028/049 030/060 034/059
4/W 31/U 11/U 11/B 32/W 00/U 00/U
HDN 046 022/052 028/062 038/059 039/053 036/061 037/061
4/W 31/U 10/U 01/B 32/W 00/U 00/U
MLS 044 022/049 030/061 041/056 038/049 035/059 039/054
3/W 21/U 11/B 12/W 32/W 00/U 00/U
4BQ 044 021/049 026/059 039/058 040/049 035/059 040/059
3/W 20/U 00/B 01/B 33/W 00/U 00/U
BHK 043 020/049 028/057 040/054 035/046 033/058 036/052
2/W 00/U 00/B 12/W 32/W 00/U 00/U
SHR 040 020/044 024/056 034/056 034/046 032/059 035/060
6/W 61/U 10/U 00/U 33/W 00/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
317 PM CDT FRI OCT 5 2012
.DISCUSSION...
A FRONTOGENETICALLY FORCED SNOW BAND CONTINUES TO DRIFT SLOWLY
EAST SOUTHEAST ACROSS THE SANDHILLS THIS AFTERNOON. THIS AREA OF
SNOW SHOULD CONTINUE MOVING EAST SOUTHEAST AND WEAKEN AS THE
THERMAL FORCING RELAXES.
ANOTHER ROUND OF SNOW IS FORECAST TO DEVELOP ACROSS SWRN NEB AND
THE PANHANDLE LATE TONIGHT THROUGH EARLY SATURDAY AFTN. THIS IS
BASED ON THE CONSENSUS OF THE 12Z GFS...WRF...NAM...GEM AND 00Z
ECM. HOWEVER THE LATEST RADAR AND RAP/HRRR SOLNS ARE SUGGESTING A
MORE EASTERLY TRACK OF THE DISTURBANCE...CURRENTLY OVER MT...WHICH
COULD PRODUCE SNOW ACROSS NCNTL NEB. THE 18Z NAM IS IN EXCELLENT
AGREEMENT WITH THE GEMREG KEEPING THE BEST FORCING AND SNOW
SOUTHWEST AND ITS NOT UNUSUAL FOR THE RAP AND HRRR TO BE OFF BUT
THE RADAR TRENDS ARE OF CONCERN. A QPF BLEND OF THE MODELS ABOVE
AND A 10 TO 1 RATIO PRODUCE 1 TO 2 INCHES OF SNOW ACROSS THE FAR
WEST AND SOUTHWEST SO NO WINTER WEATHER ADVISORY WILL BE NECESSARY
ASSUMING BRIDGES AND ROAD SURFACES DONT CROSS THE FREEZING MARK
OVERNIGHT.
THE CLOUD COVER BUILDING IN AHEAD OF THIS DISTURBANCE LEAVES A
NARROW WINDOW FOR FREEZING TEMPERATURES ACROSS LINCOLN COUNTY.
OTHER AREAS WEST REMAIN OVERCAST AND AREAS NORTH AND EAST HAVE
ALREADY HAD A FREEZE.
SKIES SHOULD CLEAR OUT BY EARLY SATURDAY EVENING WITH WINDS
BECOMING LIGHT WEST OVERNIGHT. LOW PRESSURE WILL BEGIN DROPPING
SOUTH THROUGH CANADA. A BLEND OF NAM AND MET GUIDANCE WITH NAM12 BIAS
CORRECTION PRODUCED LOWS IN THE TEENS IN SOME AREAS SUNDAY
MORNING. HIGHS REBOUND INTO THE 50S SUNDAY AFTERNOON AS WEST WINDS
CONTINUE. LOWS IN THE 20S FOLLOW MONDAY MORNING WITH HIGHS AROUND
70 MONDAY AFTERNOON. WEST WINDS WILL CONTINUE THROUGH THIS PERIOD
AS LOW PRESSURE MOVES SLOWLY EAST THROUGH MANITOBA AND
SASKATCHEWAN.
TUESDAY THROUGH FRIDAY. UPPER FLOW SHOULD TRANSITION FROM
NORTHWEST FLOW ALOFT AT THE START OF THE PERIOD...TO SOUTHWEST
FLOW ALOFT TOWARD THE END OF THE WEEK AS A LARGE UPPER LEVEL LOW
PRESSURE SYSTEM PUSHES EAST OVER THE DESERT SOUTHWEST. MODELS
AGREE SOMEWHAT THAT THIS UPPER LEVEL LOW PRESSURE SYSTEM WILL
EVENTUALLY MOVE NORTHEAST TOWARD AND ACROSS OUR AREA NEXT WEEKEND.
THIS IS JUST BEYOND THE FORECAST PERIOD...AND ANY PRECIPITATION
ASSOCIATED WITH THIS SYSTEM WOULD BE BEYOND FRIDAY...SO DRY
WEATHER IS CURRENTLY BEING FORECAST THROUGH FRIDAY.
OTHERWISE...HIGH TEMPERATURES WILL STAY MOSTLY IN THE 60S...WITH
PERHAPS ONLY 50S BY FRIDAY BEHIND A COLD FRONT. THIS FRONT SHOULD
BECOME STATIONARY JUST TO OUR SOUTH LATER FRIDAY AND THEN
POTENTIALLY MOVE BACK NORTH THROUGH THE AREA DURING THE WEEKEND AS
A WARM FRONT. WILL CONTINUE TO MONITOR THE POTENTIAL SYSTEM FOR
NEXT WEEKEND.
&&
.AVIATION...
AREAS OF MVFR CEILINGS CONTINUE ACROSS PORTIONS OF SOUTHWEST AND
WESTERN NEBRASKA. THESE ARE EXPECTED TO LIFT...AND BY EARLY
EVENING MOSTLY JUST A MID LEVEL CLOUD DECK IS EXPECTED. ANOTHER
SYSTEM WILL MOVE SOUTHEAST ACROSS THE AREA AFTER 06Z
SATURDAY...WITH CEILINGS LOWERING TO MVFR AND POSSIBLE LIGHT SNOW
WEST OF A LINE FROM KIML TO KOGA TO KAIA. SFC WINDS WILL BE LIGHT
THROUGH THE PERIOD.
&&
.FIRE WEATHER...
FIRE DANGER WILL BECOME VERY HIGH SUNDAY AND MONDAY AFTERNOON.
MODEL CONSENSUS AND BIAS CORRECTED DATA SUGGESTED RH BETWEEN 15
AND 20 PERCENT WITH WINDS GUSTING TO NEAR 25 MPH BOTH DAYS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...FREEZE WARNING FROM 10 PM THIS
EVENING TO 10 AM CDT SATURDAY FOR NEZ059.
&&
$$
SHORT TERM...CDC
AVIATION/EXTENDED...TAYLOR
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1151 PM EDT SAT OCT 6 2012
.SYNOPSIS...
A WESTERLY FLOW OF CHILLY AIR WILL CONTINUE LAKE EFFECT RAIN SHOWERS
EAST OF LAKE ONTARIO TONIGHT WITH THE REST OF THE AREA PARTLY TO MOSTLY
CLOUDY. ANOTHER WEAK WAVE OF LOW PRESSURE WILL BRING SOME LIGHT RAIN
TO MUCH OF THE REGION SUNDAY ALONG WITH MORE COOL TEMPERATURES.
SKIES WILL BEGIN TO CLEAR SUNDAY NIGHT AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION...ALTHOUGH A FEW LAKE EFFECT SHOWERS MAY
LINGER EAST OF THE LAKES. DRY WEATHER WILL RETURN FOR MONDAY AND
TUESDAY AS HIGH PRESSURE REMAINS IN PLACE.
&&
.NEAR TERM /THROUGH SUNDAY/...
LAKE EFFECT RAIN ONGOING EAST OF LAKE ONTARIO LATE THIS EVENING.
OFF LAKE ONTARIO...
THIS BAND CONTINUES TO REMAIN FAIRLY WELL ORGANIZED. KTYX RADAR
SHOWING A NEARLY CONTINUOUS LINE OF PRECIP EAST-SOUTHEAST OF LAKE
ONTARIO. LIGHT TO OCCASIONALLY MODERATE RAINFALL IS ONGOING ACROSS
NORTHERN OSWEGO AND SOUTHERN LEWIS COUNTIES. JEFFERSON AND NORTHERN
LEWIS REMAIN DRY NORTH OF THE BAND. WITH THIS BAND LOCATED FURTHER
AWAY FROM THE SURFACE RIDGING ACROSS WNY IT WILL LIKELY CONTINUE TO
STAY ORGANIZED WELL INTO THE OVERNIGHT HOURS. 00Z NAM BUFKIT
INDICATED STILL CLOSE TO 10KFT FOR LAKE EL`S AND 400 J/KG OF LAKE
INDUCED CAPE. STILL EXPECT THE BAND FOR RAIN TO CONTINUE TO MOVE
SOUTHWARD OVER THE NEXT FEW HOURS. THE LATEST HRRR AND LOCAL WRF
MODELS ARE STILL IN AGREEMENT WITH THIS IDEA BUT ARE VERIFYING A
LITTLE TO FAR SOUTH COMPARED TO CURRENT RADAR. THE BAND WILL
EVENTUALLY LIE PARALLEL WITH THE SOUTHEASTERN SHORELINE OF LAKE
ONTARIO LATE TONIGHT WITH MOST OF THE RAINFALL OCCURRING ACROSS OSWEGO
COUNTY WITH PORTIONS OF NORTHERN CAYUGA AND NORTHEASTERN WAYNE
COUNTIES ALSO CATCHING SOME LIGHT RAIN.
LATE TONIGHT INTO SUNDAY MORNING AS FLOW BEGINS TO WEAKEN...LAND
BREEZE CONVERGENCE IS FORECAST TO INCREASE ALONG THE SOUTH SHORE OF
THE LAKE...WHICH MAY PRODUCE ANOTHER PERIOD OF MORE ORGANIZED LAKE
EFFECT AT THE SOUTHEAST CORNER OF THE LAKE. BY THIS TIME THE FLOW
WILL BE MUCH WEAKER...SO THE BAND SHOULD TEND TO HUG THE LAKESHORE
MORE AND NOT EXTEND VERY FAR INLAND. FINALLY BY MIDDAY SUNDAY THE
BOUNDARY LAYER FLOW BECOMES LIGHT ENOUGH TO ALLOW THE BAND TO TEA
KETTLE AND RETRACT BACK OUT OVER THE LAKE. INSTABILITY IS A LITTLE
GREATER OFF LAKE ONTARIO...AND THE BAND MAY LAST LONGER...SO EXPECT
RAINFALL POTENTIAL OF A QUARTER TO HALF INCH HERE...WITH THE
GREATEST AMOUNTS ACROSS CENTRAL AND SOUTHERN OSWEGO COUNTY.
OFF LAKE ERIE...
THE BAND EAST OF THE LAKE HAS BROKEN APART. 850 MB TEMPS ARE PLENTY
COLD ENOUGH (-2C OFF THE 00Z KBUF SOUNDING) BUT SURFACE RIDGING HAS
BUILT ACROSS MUCH OF WESTERN NY WITH A STRONG SURFACE HIGH CENTERED
OVER THE CENTRAL PLAINS. THIS SURFACE RIDGING HAS LOWERED EQUILIBRIUM
LEVELS DOWN TO AROUND 7000 FT WHICH IS MUCH TOO SHALLOW TO SUPPORT
AND RAIN IN ADDITION TO THE SURFACE RIDGING IN PLACE.
SUNDAY MORNING THERE MAY BE A BRIEF RESURGENCE OF LAKE EFFECT
ORGANIZATION AS BOUNDARY LAYER FLOW BECOMES A LITTLE MORE WESTERLY.
THIS WILL BE SHORT LIVED HOWEVER AS LOW LEVEL FLOW BECOMES VERY
LIGHT BY LATE MORNING...WITH ANY REMAINING LAKE EFFECT TENDING TO
TEA KETTLE OUT OVER THE LAKE AND NOT EXTEND INLAND.
OUTSIDE OF THE LAKE EFFECT...MOST LOCATIONS WILL SEE PARTLY TO
MOSTLY CLOUDY SKIES. LATEST IR IMAGERY SHOWS LAKE EFFECT CLOUDS OVER
MUCH OF WNY AND WITHIN THE BAND EAST OF LAKE ONTARIO. ONLY CLEAR
SPOTS AT 03Z WERE ACROSS CNY. MID LEVEL CLOUDS CAN ALSO BE SEEN ON
IR STREAMING NORTHEAST ACROSS WESTERN PA. THESE WILL INCREASE IN
COVERAGE ACROSS WESTERN NY AHEAD OF A DEVELOPING SURFACE WAVE.
SUNDAY...FOLLOWING ANY LINGERING LAKE EFFECT IN THE MORNING...OUR
ATTENTION TURNS BACK TO THE SYNOPTIC SCALE. LATEST SHORT TERM MODEL
GUIDANCE SWINGS A STRONG SHORTWAVE THROUGH THE MEAN LONGWAVE TROUGH
POSITION...CROSSING THE OHIO VALLEY AND PENNSYLVANIA DURING THE
AFTERNOON. THIS WILL INTERACT WITH A FRONTAL ZONE TO OUR SOUTH AND
PRODUCE A BAROCLINIC LEAF...WHICH WILL ACT TO INCREASE DIFFERENTIAL
THERMAL ADVECTION AND ISENTROPIC UPGLIDE ACROSS THE LOWER LAKES.
THIS WILL BRING THICKENING AND LOWERING CLOUD COVER DURING THE DAY
WITH A MORE WIDESPREAD LIGHT RAIN DEVELOPING BY MIDDAY OR EARLY
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN TIER AND FINGER LAKES
WHERE UP TO A QUARTER INCH MAY FALL. FARTHER NORTH...EXPECT THE
NORTHERN EDGE OF THE RAIN SHIELD TO CLIP THE NIAGARA FRONTIER EAST
TO ROCHESTER AND THE TUG HILL REGION WITH A LITTLE LIGHT RAIN IN THE
AFTERNOON.
THE THICKENING CLOUD COVER AND DEVELOPING RAIN WILL BRING ANOTHER
CHILLY DAY...WITH THE LOWER ELEVATIONS ONLY TOPPING OUT IN THE LOWER
50S AT BEST...WITH MID TO UPPER 40S ACROSS HIGHER TERRAIN.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
THE MAIN CONCERN FOR THE SUNDAY NIGHT THROUGH TUESDAY NIGHT PERIOD
IS THE POTENTIAL OF FROST...OR A WIDESPREAD FREEZE. THIS WOULD BE A
GOOD TIME TO ISSUE A FREEZE WATCH FOR SUNDAY NIGHT IF CONFIDENCE WAS
HIGH ENOUGH...BUT THERE IS TOO MUCH UNCERTAINTY ABOUT CLOUD COVER
AND RESULTING LOW TEMPERATURES AT THIS TIME.
A SHORTWAVE CURRENTLY MOVING INTO NE WILL BE IN THE PROCESS OF
MOVING THROUGH THE LOWER GREAT LAKES REGION BY SUNDAY AFTERNOON AND
EVENING. RAIN ACCOMPANYING THIS SYSTEM WILL MOST LIKELY AFFECT /AT
LEAST/ THE SOUTHERN TIER AND PA BEFORE MOVING EAST DURING SUNDAY
NIGHT AS THE SURFACE BASED COASTAL LOW NEAR DELMARVA MOVES FURTHER
OFFSHORE. THE END RESULT TOWARD MONDAY MORNING WILL BE CLOUDS
OVERHEAD MOVING OFF TO THE EAST...WITH A GOOD CHANCE FOR HIGH CLOUD
COVER AT LEAST OVER THE EASTERN LAKE ONTARIO REGION. IN
ADDITION...THERE SHOULD BE SOME ONGOING LAKE EFFECT RAIN SHOWERS
EAST OF THE LAKES OVERNIGHT...WITH CLOUDS SPREADING INTO THE HIGHER
TERRAIN EAST OF LAKE ONTARIO AND INTO THE SOUTHERN TIER...THE EXACT
LOCATION THAT WOULD NORMALLY BE THE COLDEST PLACES IN WESTERN NY. A
FREEZE IS POSSIBLE ON THE FRINGES OF ANY LAKE BANDS AND/OR HIGHER
CLOUD COVER...BUT AT THIS TIME IT IS TOO UNCERTAIN AS TO HOW
WIDESPREAD THE CLOUD COVER WILL BE. WILL THEREFORE ADD IN SOME
FROST INTO THE FORECAST FOR AREAS OUTSIDE OF ANTICIPATED THICKER
CLOUD COVER...BUT KEEP TEMPERATURES ABOVE THE FREEZING MARK FOR NOW.
ON MONDAY ANY LAKE EFFECT SHOULD QUICKLY END DURING THE MORNING WITH
HIGH PRESSURE MOVING INTO THE NORTHEAST. MONDAY NIGHT WILL FEATURE
MOSTLY CLEAR SKIES...SO ALTHOUGH TEMPERATURES ALOFT WILL WARM A BIT
OVER 24 HOURS...THERE WILL ONCE AGAIN BE A LOW CHANCE FOR SOME FROST
OR FREEZING CONDITIONS DUE TO RADIATIONAL COOLING. WILL HAVE A
SLIGHTLY LARGER AREA COVERED BY FROST FOR LATE MONDAY NIGHT IN THE
TRADITIONAL INLAND LOCATIONS...PRIMARILY THE SOUTHERN TIER AND WELL
EAST OF LAKE ONTARIO.
QUIET WEATHER IS EXPECTED FOR TUESDAY WITH A CONTINUED WARMING
TREND...WITH MAX TEMPERATURES APPROACHING NORMAL VALUES FOR THIS
TIME OF YEAR.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE REX BLOCK IN PLACE OVER THE EASTERN PACIFIC WILL REMAIN IN PLACE
OR V-E-R-Y SLOWLY MOVE INTO THE WESTERN US THE COURSE OF NEXT WEEK.
THEREFORE WE NEED TO LOOK ABOVE BC...NEAR THE TOP OF THE RIDGE FOR
THE NEXT FEATURE OF INTEREST. MEDIUM RANGE GUIDANCE HAS BEEN VERY
CONSISTENT BRING THE NEXT FEATURE DOWN THROUGH ALBERTA AND
SASKATCHEWAN EARLY NEXT WEEK...WITH A SURFACE LOW REMAINING IN CA
AND PIVOTING AROUND HUDSON BAY WHILE AN ASSOCIATED COLD FRONT SWEEPS
ACROSS THE GREAT LAKES REGION AND ACROSS NYS ON WEDNESDAY. THERE IS
SOME UNCERTAINTY AS TO TIMING WITH THE FRONT/PRECIPITATION...WITH
RAIN POSSIBLE EITHER WEDNESDAY OR WEDNESDAY NIGHT. WILL KEEP
FORECAST GENERALLY UNCHANGED FOR NOW WITH LIKELY RAIN IN THE WEST IN
THE AFTERNOON.
EXPECT A FAIRLY STRONG RIDGE AFTER THIS FOR THURSDAY WITH DRY
WEATHER. THEN ANOTHER FRONT DROPS ACROSS THE REGION DURING THE END
OF NEXT WEEK FOR ANOTHER CHANCE OF RAIN. TEMPERATURES DROP QUITE A
BIT BEHIND THIS NEXT FRONTAL PASSAGE...WITH 850MB TEMPERATURES DOWN
TO -7C EAST OF LAKE ONTARIO. HOWEVER...A FAIRLY STRONG RIDGE WILL
ALSO BE IN PLACE BY THE WEEKEND. RIGHT NOW LAKE EFFECT
POSSIBILITIES LOOK MINIMAL WITH A LOW LEVEL DRY AIRMASS ACROSS THE
LOWER GREAT LAKES REGION. ALTHOUGH THE CURRENT CONCERN FOR A
FROST/FREEZE IS FOR SUNDAY OR SUNDAY NIGHT...A BIGGER CONCERN MAY BE
NEXT WEEKEND.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
LAKE EFFECT RAIN SHOWERS HAVE ENDED EAST OF LAKE ERIE BUT CONTINUE
TO BE WELL ORGANIZED EAST OF LAKE ONTARIO. LAKE EFFECT CLOUDS ARE
SPREAD OVER MUCH OF WNY AND EAST OF LAKE ONTARIO. MORE ORGANIZED
BAND OF LAKE EFFECT RAIN SHOWERS AND CLOUDS HAVE DEVELOPED. BAND OF
RAIN WILL SHIFT SOUTH TOWARD KFZY BY JUST AFTER MIDNIGHT. OCCASIONAL
MVFR CIGS AND VIS ALSO POSSIBLE IN LAKE EFFECT. OUTSIDE OF THESE
AREAS...CLEAR TO PARTLY CLOUDY SKIES WILL REMAIN MUCH OF THE NIGHT.
ON SUNDAY LAKE EFFECT RAIN SHOWERS WILL LINGER THROUGH THE MORNING
EAST OF THE LAKES WITH AREAS OF MVFR AND LOCAL IFR. BY AFTERNOON A
WEAK WAVE OF LOW PRESSURE WILL PASS BY JUST TO THE SOUTH OF THE
REGION. THIS MAY PRODUCE A LITTLE MORE WIDESPREAD LIGHT RAIN...WITH
ASSOCIATED MVFR AND LOCAL IFR CONDITIONS ESPECIALLY ACROSS HIGHER
TERRAIN.
OUTLOOK...
MONDAY AND TUESDAY...VFR.
WEDNESDAY...AREAS OF MVFR WITH SHOWERS LIKELY.
THURSDAY...MAINLY VFR.
&&
.MARINE...
WINDS DIMINISHING STEADILY OVERNIGHT AS THE PRESSURE GRADIENT
RELAXES ACROSS THE AREA. A SMALL CRAFT ADVISORY REMAINS THROUGH
SUNDAY MORNING FOR THE EAST END OF LAKE ONTARIO AS OBSERVATIONS
THERE STILL SHOWING 20 TO 25 KT WINDS.
A WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE FOR THE REST OF SUNDAY
WITH MUCH LIGHTER WINDS...AND THE LIGHT WINDS WILL LAST INTO MONDAY
AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE LOWER LAKES.
WATERSPOUTS WILL BECOME MORE LIKELY THROUGH SUNDAY MORNING OFF LAKE
ONTARIO IN AND NEAR BANDS OF LAKE EFFECT SHOWERS AND CLOUDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT SUNDAY FOR LOZ043>045.
&&
$$
SYNOPSIS...HITCHCOCK/SMITH
NEAR TERM...SMITH
SHORT TERM...ZAFF
LONG TERM...ZAFF
AVIATION...SMITH
MARINE...SMITH
AREA FORECAST DISCUSSION...CORRECTED
NWS BINGHAMTON NY
304 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A COLD FRONT WORKING OVER OUR REGION THIS AFTERNOON WILL STALL
OVERNIGHT. AS THIS OCCURS...A DISTURBANCE WILL MOVE UP THE
BOUNDARY BRINGING WITH IT AN INCREASED CHANCE FOR SHOWERS TO MUCH
OF CENTRAL NEW YORK AND NORTHEASTERN PENNSYLVANIA. SHOWERS WILL
PREVAIL ACROSS MUCH OF THE REGION SATURDAY MORNING BEFORE
CONDITIONS BEGIN TO IMPROVE BY LATE SATURDAY AFTERNOON. BEYOND
THIS...MUCH COOLER AIR WILL SETTLE INTO THE REGION WITH DAYTIME
HIGHS ONLY EXPECTED TO REACH THE UPPER 40S TO LOWER 50S BY SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN INDIAN SUMMER DAY PREVAILING ACROSS THE FCST AREA THIS AFTERNOON
IN ADVANCE OF A COLD FRONT WHICH CONTINUES TO MAKE SLOW PROGRESS
ACROSS THE REGION. SO FAR TEMPS HAVE WARMED WELL INTO THE LOWER
TO MIDDLE 70S ACROSS MOST LOCATIONS UNDER PARTLY TO MOSTLY CLOUDY
SKIES. AS IS USUALLY THE CASE...VARIOUS FCST MODELS HAVE OVERDONE
THE QPF FCST THIS AFTERNOON AS REGIONAL RADARS SHOW THE CLOSEST
SHWR ACTIVITY STILL QUITE A WAYS TO THE WEST. THAT SAID...VARIOUS
HIGH-RES MODELS TO INCLUDE THE HRRR AND WRF-ARW SUGGEST SHWRS WILL
DEVELOP AFTER 20Z AS THE FRONT CONTINUES TO MOVE THROUGH THE AREA.
WILL MAINTAIN SLGT CHC-CHC MENTION TO ACCOUNT FOR THIS POSSIBILITY.
MAIN FOCUS IN THE NEAR TERM CONTINUES TO BE INCREASING CHANCES FOR
PRECIP OVERNIGHT AS WESTERN ONTARIO CLOSED LOW SHORTWAVE ENERGY
BEGINS TO DIVE SOUTHEAST WITH TIME. AS HAS BEEN THE TREND IN RECENT
DAYS...THE COLD FRONT CURRENTLY WORKING THROUGH THE REGION WILL
EVENTUALLY SLOW DOWN AS AN AREA OF LOW PRESSURE BEGINS WORKING
NORTH ALONG THE BOUNDARY. ADDITIONALLY THE FRONT IS FCST TO BECOME
MORE ANAFRONTISH AS PRECIP BECOMES MORE WIDESPREAD WEST OF THE
BOUNDARY AS UPPER ENERGY ARRIVES FROM THE WEST. FOR NOW WILL
MAINTAIN HIGH END LIKELY TO CATEGORICAL MENTION ACROSS THE
WESTERN ZONES...WITH A GRADUAL SHIFT EAST BY SATURDAY MORNING AS
THE FRONT FINALLY BEGINS MOVING ONCE AGAIN.
FOR SATURDAY...EXPECT WIDESPREAD RAINS IN THE MORNING WITH
ACTIVITY GRADUALLY TAPERING OFF FROM WEST TO EAST BY LATE
MORNING/EARLY AFTERNOON. THE HEAVIEST RAINS WILL FALL ACROSS THE
WESTERN ZONES WHERE TOTAL QPF VALUES MAY APPROACH 1 INCH. FURTHER
SOUTH AND EAST...THE FASTER FRONTAL MOVEMENT WILL RESULT IN MUCH
LOWER PRECIP AMOUNTS WITH QPF TOTALS LARGELY REMAINING UNDER A
QUARTER TO HALF INCH AT BEST. OVERNIGHT TEMPS TONIGHT WILL REMAIN
ON THE WARM SIDE WITH VALUES FALLING ONLY INTO THE UPPER 40S TO
LOWER 50S. COLD AIR ADVECTION EXPECTED TO START TOMORROW WHICH
COMBINED WITH CLOUDS AND PRECIP SHOULD KEEP HIGHS LARGELY IN THE
50S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
UNSETTLED CONDITIONS TO PERSIST RIGHT THROUGH THE START OF THE
SHORT TERM PERIOD AS REGION REMAINS IN BROAD CYCLONIC FLOW ALOFT.
MAIN ATTENTION BY SATURDAY NIGHT WILL BE THE POSSIBILITIES FOR
DEVELOPING LAKE EFFECT ACTIVITY DOWNWIND OF LAKE ONTARIO AS COLD
AIR COMBINED WITH A FAIRLY LONG WESTERLY FETCH CREATES MARGINAL
LAKE EFFECT CONDITIONS. INSPECTION OF SEVERAL FCST SOUNDINGS
SUGGESTS BEST POTENTIAL FOR LAKE EFFECT SHWR ACTIVITY WILL BE
FROM THE SOUTHERN TUG HILL SOUTH THROUGH THE WESTERN MOHAWK VALLEY
AS FLOW WILL TAKE ON A 280-290 DEGREE CONFIGURATION. INVERSION
HEIGHTS BY 12Z SUN WILL BORDER NEAR 10 KFT WITH INCREASING
LAKE GENERATED INSTABILITY EARLY SUN AS COOLER AIR CONTINUES TO
FILTER INTO THE REGION. MAIN QUESTIONS REMAIN JUST HOW FAR SOUTH
THE DEVELOPING BAND IS ABLE TO EXTEND AS THE NAM MAINTAINS ALMOST
A PURE WESTERLY WIND COMPONENT WHILE THE GFS SUGGESTS A BIT MORE
OF A NORTHWESTERLY CONFIGURATION. FOR NOW...HAVE DECIDED TO EXTEND
PRECIP MENTION A BIT FURTHER SOUTH THAN PREVIOUSLY FCST TO INCLUDE
THE GREATER SYR AREA.
BIG QUESTIONS STILL REMAIN WITH THE NEXT SYNOPTIC SYSTEM PROGGED
TO IMPACT OUR AREA BY SUN AFTERNOON. MAIN CULPRIT WILL BE THE NEXT
NORTHERN STREAM PIECE OF ENERGY WHICH IS EXPECTED TO DIVE
SOUTHEAST TOWARDS THE EAST COAST AND INDUCE SFC CYCLOGENESIS OFF
THE COAST OF VIRGINA BEACH. WITH TIME ON SUN THIS FEATURE WILL
MOVE NORTHEAST UP THE COAST WITH INCREASED CHANCES FOR RAIN TO THE
CENTRAL MID-ATLANTIC TO INCLUDE PARTS OF OUR FCST AREA. RIGHT NOW
THE GFS AND ECMWF AND THE FARTHEST EAST WITH THE SFC LOW WHILE THE
NAM REMAINS THE FURTHEST WEST. UNDER THE GFS AND ECMWF/S
SCENARIO...THE BULK OF RAIN WOULD REMAIN SOUTH AND EAST WHILE THE
NAM SOLUTION SUGGESTS INCREASING RAIN CHANCES FOR ALMOST THE
ENTIRE CWA. FOR NOW BASED ON THE AMOUNT OF UNCERTAINTIES THAT
EXIST...WILL MAINTAIN A SLGT CHC TO CHC MENTION THROUGH SUN
AFTERNOON.
BEYOND THIS...SOME POTENTIAL FOR REDEVELOPING LAKE EFFECT ACTIVITY
WILL EXIST EAST OF LAKE ONTARIO SUN NIGHT/EARLY MON. NOT OVERLY
OPTIMISTIC AT THIS POINT AS SFC RIDGING AND AN INFLUX OF DRIER AIR
WILL QUICKLY BUILD IN OVERNIGHT AS HIGH PRESSURE SETTLES OVER THE
REGION. DRY CONDITIONS EXPECTED ON MON AS HIGH PRESSURE REMAINS IN
CONTROL.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
130 PM UPDATE...MED RANGE MODELS INDICATE SFC HIPRES OVR CWA BY 00Z
TUESDAY. ZONAL FLOW AT H5 WL KEEP MAJOR WX SYSTEMS FM MVG IN EARLY
IN THE WEEK. THIS WL CHANGE ON WED AS SFC LOW DVLPS ACRS CNTRL
GREAT LKS IN CONJUNCTION WITH H5 TROF APPCHG THE AREA AND
SPREADING PCPN INTO THE REGION AFTER 12Z WED. AS THIS LOW EXITS TO
THE EAST WED NGT EXPECT LK EFFECT SHOWERS POTENTIALLY MIXED WITH
SNOW TO BE THE DOMINANT WX FEATURE THUR MRNG. THE NEXT SYSTEM WL
SKIRT ACRS ON FRIDAY WITH ANOTHER CHC FOR RA/SN MIX BHND THIS LOW
ON FRI MRNG.
H8 TEMPS WL DROP TO BLO -3C AFTER 06Z THUR AND 12Z FRI. THIS WL
KEEP LOW TEMPS IN THE LOW-MID 30S BOTH MRNGS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
130 PM UPDATE...GNRLY VFR ACRS TERMINALS THIS AFTERNOON WILL GIVE
WAY TO MVFR AND POTENTIAL IFR OVERNIGHT AS A COLD FRONT APPROACHES
THE AREA FROM THE WEST. AREA OF RAIN IS ENTERING WESTERN NEW YORK
AT THIS TIME AND WILL POTENTIALLY AFFECT NY TERMINALS FROM 20Z-24Z
TODAY. NO RESTRICTIONS EXPECTED WITH THIS PRECIPITATION.
WIDESPREAD RAIN WILL MOVE INTO TERMINALS WELL AFTER 08Z WITH
PREDOMINANT MVFR VSBYS/CIGS SETTLING IN FROM NORTH TO SOUTH.
POTENTIAL EXISTS FOR IFR CIGS TOWARD 12Z.
WINDS OUT OF THE SOUTHWEST THIS AFTERNOON AROUND 5KTS WILL
QUICKLY GIVE WAY TO NORTHWEST WINDS BEHIND FRONT AT AROUND 10KTS
BETWEEN 10Z-14Z.
OUTLOOK...
SAT NIGHT TO SUN...SCT MVFR -SHRA ACROSS NORTHERN TERMINALS.
SUN NIGHT TO MON...MAINLY VFR ACROSS NY TERMINALS. SCT MVFR
POSSIBLE SUN NIGHT WIDELY SCATTERED -SHRA ACRS NEPA.
TUE...VFR.
WED...POTENTIAL MVFR IN SCATTERED SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
303 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A COLD FRONT WORKING OVER OUR REGION THIS AFTERNOON WILL STALL
OVERNIGHT. AS THIS OCCURS...A DISTURBANCE WILL MOVE UP THE
BOUNDARY BRINGING WITH IT AN INCREASED CHANCE FOR SHOWERS TO MUCH
OF CENTRAL NEW YORK AND NORTHEASTERN PENNSYLVANIA. SHOWERS WILL
PREVAIL ACROSS MUCH OF THE REGION SATURDAY MORNING BEFORE
CONDITIONS BEGIN TO IMPROVE BY LATE SATURDAY AFTERNOON. BEYOND
THIS...MUCH COOLER AIR WILL SETTLE INTO THE REGION WITH DAYTIME
HIGHS ONLY EXPECTED TO REACH THE UPPER 40S TO LOWER 50S BY SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN INDIAN SUMMER DAY PREVAILING ACROSS THE FCST AREA THIS AFTERNOON
IN ADVANCE OF A COLD FRONT WHICH CONTINUES TO MAKE SLOW PROGRESS
ACROSS THE REGION. SO FAR TEMPS HAVE WARMED WELL INTO THE LOWER
TO MIDDLE 70S ACROSS MOST LOCATIONS UNDER PARTLY TO MOSTLY CLOUDY
SKIES. AS IS USUALLY THE CASE...VARIOUS FCST MODELS HAVE OVERDONE
THE QPF FCST THIS AFTERNOON AS REGIONAL RADARS SHOW THE CLOSEST
SHWR ACTIVITY STILL QUITE A WAYS TO THE WEST. THAT SAID...VARIOUS
HIGH-RES MODELS TO INCLUDE THE HRRR AND WRF-ARW SUGGEST SHWRS WILL
DEVELOP AFTER 20Z AS THE FRONT CONTINUES TO MOVE THROUGH THE AREA.
WILL MAINTAIN SLGT CHC-CHC MENTION TO ACCOUNT FOR THIS POSSIBILITY
HOWEVER OVERALL CONFIDENCE REMAINS MARGINAL.
MAIN FOCUS IN THE NEAR TERM CONTINUES TO BE INCREASING CHANCES FOR
PRECIP OVERNIGHT AS WESTERN ONTARIO CLOSED LOW SHORTWAVE ENERGY
BEGINS TO DIVE SOUTHEAST WITH TIME. AS HAS BEEN THE TREND IN RECENT
DAYS...THE COLD FRONT CURRENTLY WORKING THROUGH THE REGION WILL
EVENTUALLY SLOW DOWN AS AN AREA OF LOW PRESSURE BEGINS WORKING
NORTH ALONG THE BOUNDARY. ADDITIONALLY THE FRONT IS FCST TO BECOME
MORE ANAFRONTISH AS PRECIP BECOMES MORE WIDESPREAD WEST OF THE
BOUNDARY AS UPPER ENERGY ARRIVES FROM THE WEST. FOR NOW WILL
MAINTAIN HIGH END LIKELY TO CATEGORICAL MENTION ACROSS THE
WESTERN ZONES...WITH A GRADUAL SHIFT EAST BY SATURDAY MORNING AS
THE FRONT FINALLY BEGINS MOVING ONCE AGAIN.
FOR SATURDAY...EXPECT WIDESPREAD RAINS IN THE MORNING WITH
ACTIVITY GRADUALLY TAPERING OFF FROM WEST TO EAST BY LATE
MORNING/EARLY AFTERNOON. THE HEAVIEST RAINS WILL FALL ACROSS THE
WESTERN ZONES WHERE TOTAL QPF VALUES MAY APPROACH 1 INCH. FURTHER
SOUTH AND EAST...THE FASTER FRONTAL MOVEMENT WILL RESULT IN MUCH
LOWER PRECIP AMOUNTS WITH QPF TOTALS LARGELY REMAINING UNDER A
QUARTER TO HALF INCH AT BEST. OVERNIGHT TEMPS TONIGHT WILL REMAIN
ON THE WARM SIDE WITH VALUES FALLING ONLY INTO THE UPPER 40S TO
LOWER 50S. COLD AIR ADVECTION EXPECTED TO START TOMORROW WHICH
COMBINED WITH CLOUDS AND PRECIP SHOULD KEEP HIGHS LARGELY IN THE
50S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
UNSETTLED CONDITIONS TO PERSIST RIGHT THROUGH THE START OF THE
SHORT TERM PERIOD AS REGION REMAINS IN BROAD CYCLONIC FLOW ALOFT.
MAIN ATTENTION BY SATURDAY NIGHT WILL BE THE POSSIBILITIES FOR
DEVELOPING LAKE EFFECT ACTIVITY DOWNWIND OF LAKE ONTARIO AS COLD
AIR COMBINED WITH A FAIRLY LONG WESTERLY FETCH CREATES MARGINAL
LAKE EFFECT CONDITIONS. INSPECTION OF SEVERAL FCST SOUNDINGS
SUGGESTS BEST POTENTIAL FOR LAKE EFFECT SHWR ACTIVITY WILL BE
FROM THE SOUTHERN TUG HILL SOUTH THROUGH THE WESTERN MOHAWK VALLEY
AS FLOW WILL TAKE ON A 280-290 DEGREE CONFIGURATION. INVERSION
HEIGHTS BY 12Z SUN WILL BORDER NEAR 10 KFT WITH INCREASING
LAKE GENERATED INSTABILITY EARLY SUN AS COOLER AIR CONTINUES TO
FILTER INTO THE REGION. MAIN QUESTIONS REMAIN JUST HOW FAR SOUTH
THE DEVELOPING BAND IS ABLE TO EXTEND AS THE NAM MAINTAINS ALMOST
A PURE WESTERLY WIND COMPONENT WHILE THE GFS SUGGESTS A BIT MORE
OF A NORTHWESTERLY CONFIGURATION. FOR NOW...HAVE DECIDED TO EXTEND
PRECIP MENTION A BIT FURTHER SOUTH THAN PREVIOUSLY FCST TO INCLUDE
THE GREATER SYR AREA.
BIG QUESTIONS STILL REMAIN WITH THE NEXT SYNOPTIC SYSTEM PROGGED
TO IMPACT OUR AREA BY SUN AFTERNOON. MAIN CULPRIT WILL BE THE NEXT
NORTHERN STREAM PIECE OF ENERGY WHICH IS EXPECTED TO DIVE
SOUTHEAST TOWARDS THE EAST COAST AND INDUCE SFC CYCLOGENESIS OFF
THE COAST OF VIRGINA BEACH. WITH TIME ON SUN THIS FEATURE WILL
MOVE NORTHEAST UP THE COAST WITH INCREASED CHANCES FOR RAIN TO THE
CENTRAL MID-ATLANTIC TO INCLUDE PARTS OF OUR FCST AREA. RIGHT NOW
THE GFS AND ECMWF AND THE FARTHEST EAST WITH THE SFC LOW WHILE THE
NAM REMAINS THE FURTHEST WEST. UNDER THE GFS AND ECMWF/S
SCENARIO...THE BULK OF RAIN WOULD REMAIN SOUTH AND EAST WHILE THE
NAM SOLUTION SUGGESTS INCREASING RAIN CHANCES FOR ALMOST THE
ENTIRE CWA. FOR NOW BASED ON THE AMOUNT OF UNCERTAINTIES THAT
EXIST...WILL MAINTAIN A SLGT CHC TO CHC MENTION THROUGH SUN
AFTERNOON.
BEYOND THIS...SOME POTENTIAL FOR REDEVELOPING LAKE EFFECT ACTIVITY
WILL EXIST EAST OF LAKE ONTARIO SUN NIGHT/EARLY MON. NOT OVERLY
OPTIMISTIC AT THIS POINT AS SFC RIDGING AND AN INFLUX OF DRIER AIR
WILL QUICKLY BUILD IN OVERNIGHT AS HIGH PRESSURE SETTLES OVER THE
REGION. DRY CONDITIONS EXPECTED ON MON AS HIGH PRESSURE REMAINS IN
CONTROL.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
130 PM UPDATE...MED RANGE MODELS INDICATE SFC HIPRES OVR CWA BY 00Z
TUESDAY. ZONAL FLOW AT H5 WL KEEP MAJOR WX SYSTEMS FM MVG IN EARLY
IN THE WEEK. THIS WL CHANGE ON WED AS SFC LOW DVLPS ACRS CNTRL
GREAT LKS IN CONJUNCTION WITH H5 TROF APPCHG THE AREA AND
SPREADING PCPN INTO THE REGION AFTER 12Z WED. AS THIS LOW EXITS TO
THE EAST WED NGT EXPECT LK EFFECT SHOWERS POTENTIALLY MIXED WITH
SNOW TO BE THE DOMINANT WX FEATURE THUR MRNG. THE NEXT SYSTEM WL
SKIRT ACRS ON FRIDAY WITH ANOTHER CHC FOR RA/SN MIX BHND THIS LOW
ON FRI MRNG.
H8 TEMPS WL DROP TO BLO -3C AFTER 06Z THUR AND 12Z FRI. THIS WL
KEEP LOW TEMPS IN THE LOW-MID 30S BOTH MRNGS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
130 PM UPDATE...GNRLY VFR ACRS TERMINALS THIS AFTERNOON WILL GIVE
WAY TO MVFR AND POTENTIAL IFR OVERNIGHT AS A COLD FRONT APPROACHES
THE AREA FROM THE WEST. AREA OF RAIN IS ENTERING WESTERN NEW YORK
AT THIS TIME AND WILL POTENTIALLY AFFECT NY TERMINALS FROM 20Z-24Z
TODAY. NO RESTRICTIONS EXPECTED WITH THIS PRECIPITATION.
WIDESPREAD RAIN WILL MOVE INTO TERMINALS WELL AFTER 08Z WITH
PREDOMINANT MVFR VSBYS/CIGS SETTLING IN FROM NORTH TO SOUTH.
POTENTIAL EXISTS FOR IFR CIGS TOWARD 12Z.
WINDS OUT OF THE SOUTHWEST THIS AFTERNOON AROUND 5KTS WILL
QUICKLY GIVE WAY TO NORTHWEST WINDS BEHIND FRONT AT AROUND 10KTS
BETWEEN 10Z-14Z.
OUTLOOK...
SAT NIGHT TO SUN...SCT MVFR -SHRA ACROSS NORTHERN TERMINALS.
SUN NIGHT TO MON...MAINLY VFR ACROSS NY TERMINALS. SCT MVFR
POSSIBLE SUN NIGHT WIDELY SCATTERED -SHRA ACRS NEPA.
TUE...VFR.
WED...POTENTIAL MVFR IN SCATTERED SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
143 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING AND BRING IN
COOLER TEMPERATURES. A TROUGH OF LOW PRESSURE WILL ROTATE ACROSS
THE EASTERN GREAT LAKES SATURDAY NIGHT. A RIDGE OF HIGH PRESSURE
WILL EXTEND NORTHEAST OVER THE AREA SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONTAL BOUNDARY IS MAKING SLOW PROGRESS ACROSS THE CWA
THIS AFTERNOON WITH THE HRRR MODEL HANDLING THE PROGRESSION OF THE
SHOWERS RATHER WELL. TEMPERATURES HAVE REACHED NEAR 70 IN THE FAR
SOUTHEAST COUNTIES AHEAD OF THE BOUNDARY WITH COOLER READINGS
BEHIND THE FRONT. REGIONAL MOSAIC RADAR ALREADY SHOWS MORE SHOWERS
OVERSPREADING NORTHERN ILLINOIS AND INDIANA WHICH WILL REACH OHIO
THIS EVENING. ONLY MINOR ADJUSTMENTS MADE TO TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
COLDEST AIR OF THE SEASON MOVES IN TONIGHT AND STICKS AROUND
THROUGH THE WEEKEND. RAIN SHOWERS WILL BE ONGOING DURING THE
EVENING AND WILL SLOWLY END FROM WEST TO EAST OVERNIGHT. THERE MAY
BE A FEW LINGERING SHOWERS ACROSS THE EAST IN THE MORNING...BUT
OVERALL A FAIR BUT COOL WEATHER DAY SATURDAY. WE ARE TALKING HIGHS
ONLY IN THE LOWER/MID 50S AFTER MORNING LOWS FROM 38 TO 45.
THERE ARE A FEW MORE QUESTIONS ABOUT THE WEATHER FOR SATURDAY
NIGHT THROUGH SUNDAY NIGHT YET. OVERALL THERE IS A SECONDARY
TROUGH COMING DOWN ACROSS THE GREAT LAKES SATURDAY INTO SATURDAY
NIGHT WHILE HIGH PRESSURE BUILDS OVER THE PLAINS AND MIDWEST.
ELONGATED TROUGH ALOFT. QUESTIONS WITH HOW MUCH MOISTURE THE GREAT
LAKES TROUGH WILL HAVE...ITS TIMING AND THEN HOW MUCH INFLUENCE
ONE LAST SHORTWAVE MOVING THROUGH THE MEAN TROUGH WILL HAVE. ECMWF
STICKING ITS GROUND AND TAKING A SHARPER SHORTWAVE ACROSS SUNDAY
AND BRINGING PRECIP INTO MUCH OF THE AREA. GFS HOLDING ON WITH
THE GREAT LAKES TROUGH BEING MORE SIGNIFICANT AND THEN POSSIBLY
HAVING TO DEAL WITH SOME LAKE EFFECT/ENHANCED SHOWERS. TIMING AND
DIRECTION OF FLOW WILL DETERMINE WHERE THESE SHOWERS WOULD BE.
THUNDER COULD ACCOMPANY SOME OF THESE SHOWERS SATURDAY NIGHT INTO
SUNDAY OVER THE LAKE WITH LAKE TEMP AND H5 TEMP DIFFERENCE LARGE
ENOUGH. SO FOR NOW HAVE SOME GENERIC POPS FOR SAT NIGHT AND
SUNDAY. WITH THE CLOUD COVER SHOULD KEEP SAT NIGHT LOWS IN THE
UPPER 30S/AROUND 40. COULD A SLUSHY FLAKE OR TWO MIX IN IN THE
HIGHEST ELEVATIONS...POSSIBLY...BUT WITH ALL THE UNCERTAINTY WILL
NOT MENTION YET. HAVE LEANED EVER SO SLIGHTLY TOWARD THE ECMWF AND
THEREFORE HAVE KEPT THE HIGHS SUNDAY LOWER THAN THE GFS MOS
GUIDANCE...MID AND UPPER 40S ONLY.
BY SUNDAY NIGHT INTO MONDAY HIGH PRESSURE BUILDING INTO THE LOCAL
AREA. SUNDAY NIGHT STILL LOOKS TO BE THE COLDEST NIGHT AND HAVE
TEMPS IN THE LOWER/MID 30S. A FROST/FREEZE IS POSSIBLE AWAY FROM
THE LAKE AND WILL CONTINUE TO HIGHLIGHT IN THE HAZARDOUS WEATHER
OUTLOOK.
MONDAY FAIR WITH HIGH PRESSURE BEGINNING TO SHIFT EAST. THIS WILL
ALLOW TEMPS TO RECOVER INTO THE 50S FOR HIGHS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A COLD FRONT MOVES THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY.
CONTINUING WITH THE THREAT OF SHOWERS TUESDAY NIGHT. THE POPS MAY
NEED TO BE ADJUSTED A LITTLE...HIGHER. WITH TIMING ISSUES WILL NOT
MAKE ANY CHANGES NOW...BECAUSE THE IDEA IS RIGHT. SOME LAKE INDUCED
SHOWERS COULD OCCUR WEDNESDAY NIGHT BUT THE HIGH BUILDS IN FAST AND
STRONG...SO WILL KEEP THURSDAY DRY. TEMPERATURES WILL BE BELOW
NORMAL.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
COLD FRONT CONTINUES TO SLOWLY MOVE THROUGH THE FORECAST AREA.
WIDESPREAD RAIN HAS DEVELOPED IN ADVANCE OF THE FRONT. CEILING
HEIGHTS AROUND 1.5 KFT ARE OCCURRING WITH THE HEAVIEST RAIN AND
OTHER CEILINGS AROUND 2.5 KFT SURROUND THIS AREA. VISIBILITIES IN
THE RAIN ARE GENERALLY RANGING FROM 2 TO 4 MILES. EXPECT THIS
TREND TO CONTINUE THIS AFTERNOON AND INTO THE EVENING AS MORE
PRECIPITATION IS FORMING TO THE WEST. MODELS SHOW THE
PRECIPITATION ENDING AFTER MIDNIGHT TONIGHT. SLOWLY DRIER AIR WILL
BUILD OVER THE AREA ON SATURDAY. CLOUDS MAY LINGER OVER THE
EASTERN AREAS AS COLD AIR MOVES OVER THE LAKES ON SATURDAY.
WINDS WILL GENERALLY MAINTAIN A WESTERLY DIRECTION AND MAY VARY
BETWEEN SOUTHWEST TO NORTHWEST DURING THE PERIOD.
.OUTLOOK...NON-VFR SATURDAY AFTERNOON INTO SUNDAY...ESPECIALLY
OVER NORTHEAST OHIO AND NORTHWEST PA.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS LAKE ERIE THIS MORNING. THE WINDS WILL
BECOME WEST AFTER FRONTAL PASSAGE AND THEN MAY DECREASE SOME THIS
EVENING BEFORE PICKING UP AGAIN BY DAYBREAK SATURDAY. IT WILL BE
MAINLY A WEST WIND SO WILL ISSUE A SMALL CRAFT ADVISORY FROM LAKE
COUNTY EAST UNTIL EARLY SUNDAY MORNING. THE WESTERLY FLOW SHOULD
CAUSE WAVES TO INCREASE TO 3 TO 5 FEET THIS MORNING...THEY WILL
PROBABLY FLUCTUATE AND WILL DEFINITELY BE AT SMALL CRAFT ADVISORY
CRITERIA SATURDAY BEFORE DECREASING SATURDAY NIGHT. THE SMALL CRAFT
MAY HAVE TO BE EXTENDED A LITTLE WEST ON SATURDAY AS THE WINDS WILL
BE STRONGEST AND MOST CONSISTENT THEN.
WATERSPOUTS WILL BE POSSIBLE ON THE LAKE MAINLY SATURDAY AFTERNOON
INTO SATURDAY NIGHT. WILL MENTION IN HAZARDOUS WEATHER OUTLOOK.
A RIDGE WILL BE BUILDING INTO THE OHIO VALLEY SUNDAY AND AS THE
RIDGE BECOMES ESTABLISHED BY MONDAY MORNING THE WINDS WILL BECOME
SOUTHWEST ON THE LAKE. THE SOUTHWEST FLOW WILL INCREASE MONDAY AND
TUESDAY AND THE SPEEDS COULD GET CLOSE TO 20 TO 25 KNOTS NEEDING A
SMALL CRAFT ADVISORY...THIS WILL HAVE TO BE MONITORED. A COLD FRONT
MOVES ACROSS THE LAKE LATE TUESDAY NIGHT AND WEDNESDAY...ANOTHER
SMALL CRAFT WILL LIKELY BE NEEDED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT SUNDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...REL
SHORT TERM...OUDEMAN
LONG TERM...KIELTYKA
AVIATION...GARNET
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1234 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING AND BRING IN
COOLER TEMPERATURES. A TROUGH OF LOW PRESSURE WILL ROTATE ACROSS
THE EASTERN GREAT LAKES SATURDAY NIGHT. A RIDGE OF HIGH PRESSURE
WILL EXTEND NORTHEAST OVER THE AREA SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONTAL BOUNDARY IS MAKING SLOW PROGRESS ACROSS THE CWA
THIS AFTERNOON WITH THE HRRR MODEL HANDLING THE PROGRESSION OF THE
SHOWERS RATHER WELL. TEMPERATURES HAVE REACHED NEAR 70 IN THE FAR
SOUTHEAST COUNTIES AHEAD OF THE BOUNDARY WITH COOLER READINGS
BEHIND THE FRONT. REGIONAL MOSAIC RADAR ALREADY SHOWS MORE SHOWERS
OVERSPREADING NORTHERN ILLINOIS AND INDIANA WHICH WILL REACH OHIO
THIS EVENING. ONLY MINOR ADJUSTMENTS MADE TO TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
COLDEST AIR OF THE SEASON MOVES IN TONIGHT AND STICKS AROUND
THROUGH THE WEEKEND. RAIN SHOWERS WILL BE ONGOING DURING THE
EVENING AND WILL SLOWLY END FROM WEST TO EAST OVERNIGHT. THERE MAY
BE A FEW LINGERING SHOWERS ACROSS THE EAST IN THE MORNING...BUT
OVERALL A FAIR BUT COOL WEATHER DAY SATURDAY. WE ARE TALKING HIGHS
ONLY IN THE LOWER/MID 50S AFTER MORNING LOWS FROM 38 TO 45.
THERE ARE A FEW MORE QUESTIONS ABOUT THE WEATHER FOR SATURDAY
NIGHT THROUGH SUNDAY NIGHT YET. OVERALL THERE IS A SECONDARY
TROUGH COMING DOWN ACROSS THE GREAT LAKES SATURDAY INTO SATURDAY
NIGHT WHILE HIGH PRESSURE BUILDS OVER THE PLAINS AND MIDWEST.
ELONGATED TROUGH ALOFT. QUESTIONS WITH HOW MUCH MOISTURE THE GREAT
LAKES TROUGH WILL HAVE...ITS TIMING AND THEN HOW MUCH INFLUENCE
ONE LAST SHORTWAVE MOVING THROUGH THE MEAN TROUGH WILL HAVE. ECMWF
STICKING ITS GROUND AND TAKING A SHARPER SHORTWAVE ACROSS SUNDAY
AND BRINGING PRECIP INTO MUCH OF THE AREA. GFS HOLDING ON WITH
THE GREAT LAKES TROUGH BEING MORE SIGNIFICANT AND THEN POSSIBLY
HAVING TO DEAL WITH SOME LAKE EFFECT/ENHANCED SHOWERS. TIMING AND
DIRECTION OF FLOW WILL DETERMINE WHERE THESE SHOWERS WOULD BE.
THUNDER COULD ACCOMPANY SOME OF THESE SHOWERS SATURDAY NIGHT INTO
SUNDAY OVER THE LAKE WITH LAKE TEMP AND H5 TEMP DIFFERENCE LARGE
ENOUGH. SO FOR NOW HAVE SOME GENERIC POPS FOR SAT NIGHT AND
SUNDAY. WITH THE CLOUD COVER SHOULD KEEP SAT NIGHT LOWS IN THE
UPPER 30S/AROUND 40. COULD A SLUSHY FLAKE OR TWO MIX IN IN THE
HIGHEST ELEVATIONS...POSSIBLY...BUT WITH ALL THE UNCERTAINTY WILL
NOT MENTION YET. HAVE LEANED EVER SO SLIGHTLY TOWARD THE ECMWF AND
THEREFORE HAVE KEPT THE HIGHS SUNDAY LOWER THAN THE GFS MOS
GUIDANCE...MID AND UPPER 40S ONLY.
BY SUNDAY NIGHT INTO MONDAY HIGH PRESSURE BUILDING INTO THE LOCAL
AREA. SUNDAY NIGHT STILL LOOKS TO BE THE COLDEST NIGHT AND HAVE
TEMPS IN THE LOWER/MID 30S. A FROST/FREEZE IS POSSIBLE AWAY FROM
THE LAKE AND WILL CONTINUE TO HIGHLIGHT IN THE HAZARDOUS WEATHER
OUTLOOK.
MONDAY FAIR WITH HIGH PRESSURE BEGINNING TO SHIFT EAST. THIS WILL
ALLOW TEMPS TO RECOVER INTO THE 50S FOR HIGHS.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
A COLD FRONT MOVES THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY.
CONTINUING WITH THE THREAT OF SHOWERS TUESDAY NIGHT. THE POPS MAY
NEED TO BE ADJUSTED A LITTLE...HIGHER. WITH TIMING ISSUES WILL NOT
MAKE ANY CHANGES NOW...BECAUSE THE IDEA IS RIGHT. SOME LAKE INDUCED
SHOWERS COULD OCCUR WEDNESDAY NIGHT BUT THE HIGH BUILDS IN FAST AND
STRONG...SO WILL KEEP THURSDAY DRY. TEMPERATURES WILL BE BELOW
NORMAL.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
COLD FRONT WILL MOVE THROUGH MFD AND CLE AROUND 12Z AND ERI AND
YNG 15Z-16Z. A BRIEF PERIOD OF CEILINGS AROUND 1500 FEET WILL
OCCUR AFTER THE FRONTAL PASSAGE. THE RAIN IS ON THE OH AND INDIANA LINE
AND MOVING EAST. THE MODELS ALL HAVE THE SAME IDEA BUT DIFFERENCES
IN THE MOISTURE AND TIMING. CONDITIONS SHOULD DROP TO MVFR...THE
SREF SEEMS TO HAVE A GOOD HANDLE ON THINGS. CONFIDENCE IN THE
TIMING OF THE LOWERING CONDITIONS IS MODERATE AT THIS TIME. ANY
IFR CONDITIONS SHOULD BE BRIEF AND COULD BE EITHER VISIBILITY OR
CEILINGS. CONDITIONS WILL BEGIN IMPROVING TO VFR FROM THE
NORTHWEST LATE THIS EVENING. BY DAYBREAK SATURDAY THE LAKE AND 850
MB TEMPERATURE DIFFERENCE WILL BE NEAR 19C. WITH THE FLOW WESTERLY
THE SHOWERS SHOULD BE MAINLY EAST OF CLE.
.OUTLOOK...NON-VFR SATURDAY AFTERNOON INTO SUNDAY...ESPECIALLY
OVER NORTHEAST OHIO AND NORTHWEST PA.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS LAKE ERIE THIS MORNING. THE WINDS WILL
BECOME WEST AFTER FRONTAL PASSAGE AND THEN MAY DECREASE SOME THIS
EVENING BEFORE PICKING UP AGAIN BY DAYBREAK SATURDAY. IT WILL BE
MAINLY A WEST WIND SO WILL ISSUE A SMALL CRAFT ADVISORY FROM LAKE
COUNTY EAST UNTIL EARLY SUNDAY MORNING. THE WESTERLY FLOW SHOULD
CAUSE WAVES TO INCREASE TO 3 TO 5 FEET THIS MORNING...THEY WILL
PROBABLY FLUCTUATE AND WILL DEFINITELY BE AT SMALL CRAFT ADVISORY
CRITERIA SATURDAY BEFORE DECREASING SATURDAY NIGHT. THE SMALL CRAFT
MAY HAVE TO BE EXTENDED A LITTLE WEST ON SATURDAY AS THE WINDS WILL
BE STRONGEST AND MOST CONSISTENT THEN.
WATERSPOUTS WILL BE POSSIBLE ON THE LAKE MAINLY SATURDAY AFTERNOON
INTO SATURDAY NIGHT. WILL MENTION IN HAZARDOUS WEATHER OUTLOOK.
A RIDGE WILL BE BUILDING INTO THE OHIO VALLEY SUNDAY AND AS THE
RIDGE BECOMES ESTABLISHED BY MONDAY MORNING THE WINDS WILL BECOME
SOUTHWEST ON THE LAKE. THE SOUTHWEST FLOW WILL INCREASE MONDAY AND
TUESDAY AND THE SPEEDS COULD GET CLOSE TO 20 TO 25 KNOTS NEEDING A
SMALL CRAFT ADVISORY...THIS WILL HAVE TO BE MONITORED. A COLD FRONT
MOVES ACROSS THE LAKE LATE TUESDAY NIGHT AND WEDNESDAY...ANOTHER
SMALL CRAFT WILL LIKELY BE NEEDED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 AM EDT SUNDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...REL
SHORT TERM...OUDEMAN
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS TULSA OK
1151 PM CDT THU OCT 4 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 6Z TAFS... RAIN SHOWERS AND SCATTERED THUNDERSTORMS ARE
EXPECTED TO AFFECT MUCH OF THE AREA OVERNIGHT. CEILINGS ARE
EXPECTED TO FALL TO MVFR LEVELS... WITH LIGHT DRIZZLE PERSISTING
THROUGHOUT MUCH OF THE DAY FRIDAY. CONDITIONS WILL SLOWLY IMPROVE
FROM THE NORTH THROUGH THE AFTERNOON AND EVENING.
&&
.PREV DISCUSSION... /ISSUED 756 PM CDT THU OCT 4 2012/
DISCUSSION...
SHALLOW FRONT CONTINUES TO WEDGE ITS WAY SOUTH...LOCATED FROM
GROVE TO ADA AT 00Z. THE SOUTHWARD PUSH SHOULD HALT BY LATE
TONIGHT IN THE ELEVATED TERRAIN OF SOUTHEAST OK AND NORTHWEST AR.
THE LATEST DATA CONTINUES TO INDICATE SOME ELEVATED SHOWER AND
STORM DVLPMT LATER TONIGHT MAINLY ACROSS NORTHEAST OK.
HOWEVER...THE LATEST HRRR ISN`T VERY AGGRESSIVE WITH DVLPMT
TONIGHT...WHILE OTHER MODELS SUCH AS THE GFS AND ECMWF SHOW THE
HEAVIER QPF NORTH OF THE KANSAS BORDER. THUS...I HAVE TRENDED POPS
LOWER AND HAVE REDUCED THUNDER CHANCES TO JUST SCT FOR TONIGHT.
UPDATED TEXT PRODUCTS SENT.
LACY
PREV DISCUSSION... /ISSUED 624 PM CDT THU OCT 4 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 0Z TAFS... A SLOW MOVING COLD FRONT/WIND SHIFT IS CURRENTLY
WORKING ITS WAY SOUTHWARD ACROSS THE REGION. NORTHEAST OKLAHOMA
SITES HAVE ALREADY SHIFTED TO THE NORTH. KMLC AND ARKANSAS SITES
WILL FOLLOW BY 6Z. ARKANSAS SITES WILL HAVE THE BEST POSSIBILITY
FOR THUNDERSTORMS EARLY FRIDAY LASTING INTO MID MORNING.
WIDESPREAD MVFR CEILINGS ARE EXPECTED IN THE WAKE OF THE FRONT.
PREV DISCUSSION... /ISSUED 344 PM CDT THU OCT 4 2012/
DISCUSSION...
MUCH ANTICIPATED COLD FRONT HAS ARRIVED IN NORTHEAST OK AND WAS
POSITIONED NEAR I-44 AT 3 PM. AT THIS TIME ONLY MODEST PRESSURE
RISES NOTED IMMEDIATELY IN ITS WAKE AND THE FRONTS PROGRESS
SOUTHEAST WILL BE SLOW WITH THE FRONT LIKELY STALLING AS IT BEGINS
TO ENCOUNTER HIGHER TERRAIN. RELATIVELY HIGH DEW POINTS POOLING
NEAR THE BOUNDARY IN SOUTHERN OK HAVE RESULTED IN A NARROW AXIS OF
INSTABILITY...HOWEVER WARM MID LEVEL TEMPS KEEPING A STRONG CAP IN
PLACE AND CLOUD COVER HAS LIMITED SFC HEATING POTENTIAL SOMEWHAT.
STILL A SMALL THREAT OF AN ISOLATED STORM DEVELOPING ALONG
BOUNDARY BUT BETTER CHANCES ARRIVE LATE THIS EVENING WITH
STRENGTHENING WINDS ATOP THE COOL AIR EVENTUALLY RESULTING IN
WIDESPREAD ELEVATED THUNDERSTORMS NORTH OF THE FRONT. THE
INCREASING DEEP LAYER SHEAR DOES LEND AT LEAST SOME POSSIBILITY TO
ORGANIZED STORMS BUT OVERALL SEVERE THREAT LOOKS LOW AT THIS TIME.
PROGRESS OF THE FRONT WILL CONTINUE TO BE SLOW THROUGH THE DAY
FRIDAY WITH POST FRONTAL SHOWERS AND A FEW THUNDERSTORMS SHIFTING
EAST. THIS WILL LIKELY RESULT IN A WIDE RANGE OF HIGH TEMPS ACROSS
THE AREA AND A ZONE OF HIGH UNCERTAINTY FROM NW CORNER OF ARKANSAS
THROUGH SE OKLAHOMA. IN GENERAL HAVE GONE LOWER THE GUIDANCE FOR
MAX TEMPS...WITH EXCEPTION OF THOSE AREAS. BREAK IN PRECIP WILL
OCCUR FOR A TIME LATE FRIDAY BEFORE ANOTHER SURGE NORTH OF THE
FRONT FRIDAY NIGHT...WHICH BY THIS TIME SHOULD BE SOUTH OF THE RED
RIVER AS REINFORCING SHOT OF DEEPER COLD AIR ARRIVES.
APPROACHING UPPER LEVEL WAVE FROM THE NORTHWEST WILL KEEP RAIN
CHANCES GOING THROUGH SATURDAY WITH TEMPS STRUGGLING TO REACH 50
IN MANY AREAS...AND RECORD LOW MAXES VERY LIKELY AT TUL/FSM. AS
THIS WAVE PASSES TO THE NORTH...WILL BEGIN TO SEE SOME CLEARING
ACROSS NORTHERN AREAS. POTENTIAL FOR FREEZING TEMPS LOOKING HIGH
OVER FAR NORTHERN AREAS...HOWEVER THERE REMAINS SOME UNCERTAINTY
AS TO HOW MUCH SKIES WILL CLEAR AND HOW SOON. WITH THIS
UNCERTAINTY IN PLACE IN THE 5TH PERIOD OF THE FORECAST WILL NOT
ISSUE A FREEZE WATCH YET...BUT SOME HIGHLIGHTS LIKELY TO BE NEEDED
FOR SUN MORNING ESPECIALLY GIVEN HOW EARLY IN THE SEASON IT IS.
CONTINUED COOL SUNDAY WITH LIGHT WINDS...WHICH COME AROUND SOUTH
LATE. HOWEVER...NIT LATE ENOUGH TO KEEP TEMPS FROM FALLING AT OR A
LITTLE BELOW FREEZING IN THE MORE SHELTERED VALLEY AREAS TO THE
EAST AND SOUTH. A NICE WARM UP WILL OCCUR TUE AHEAD OF ANOTHER
APPROACHING FRONT WHICH WILL BRING ANOTHER CHANCE OF PRECIP TO THE
AREA WED/THU.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
908 PM CDT SAT OCT 6 2012
.UPDATE...
EXPECT CLOUD COVER TO REMAIN LONGER. LATEST RUC SOUNDINGS HAVE A
STRONGER INVERSION JUST ABOVE THE CLOUD DECK AROUND 7 THSD FT.
PILOT REPORTS HAVE THE CLOUD THICKNESS AROUND 1 TO 1.5 THSD FT.
DVN 00Z UPPER AIR PROFILE HAS A VERY SHALLOW MOIST LAYER. GRB`S IS
A LITTLE THICKER. 00Z NAM SOUNDINGS SHOW THE 850 MB MOISTURE
REMAINING LONGER AND HAS A RATHER CHAOTIC DRYING. THEREFORE EXPECT
CLOUDS TO GRADUALLY THIN...AND SOME BREAKS SHOULD FORM.
WILL LEAVE THE FREEZE WARNINGS SINCE TEMPERATURES ARE IN THE MID
30S TO LOWER 40S AND ANY CLEARING WOULD RESULT IN TEMPERATURES
DROPPING INTO THE UPPER 20S. HOWEVER DO NOT EXPECT A WIDESPREAD
HARD FREEZE DUE TO THE CLOUDS.
&&
.AVIATION/06Z TAFS/...
PERSISTENT STRATOCUMULUS DECK AROUND 5 TO 6 THSD FT SHOULD
GRADUALLY THIN WITH SOME AREAS BECOMING SCATTERED DURING THE EARLY
MORNING.
MID LEVEL TROUGH AXIS WILL EXIT FAR SOUTHEAST WISCONSIN AROUND 12
TO 15Z...AND A MORE GENERAL CLEARING IS EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 255 PM CDT SAT OCT 6 2012/
TONIGHT AND SUNDAY...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
VORTICITY MAXIMUM SLIDING EAST INTO THE AREA MAY BRING SOME
SPRINKLES TO THE AREA UNTIL SUNSET...BUT LEFT OUT OF FORECAST WITH
LIMITED AREAL COVERAGE EXPECTED.
OTHERWISE...BROKEN TO OVERCAST AREA OF CLOUDS OVER THE AREA SHOULD
LINGER INTO THE EARLY TO MID EVENING HOURS...WITHIN BROAD CYCLONIC
MIDDLE TO UPPER LEVEL FLOW. AREA FORECAST SOUNDINGS AND SHORT TERM
MODEL LOW LEVEL MOISTURE PRODUCTS SUPPORT THIS AS WELL. THIS DECK
SHOULD SLOWLY MIX OUT LATER THIS EVENING AND OVERNIGHT...AS COLD AIR
ADVECTION CONTINUES TO BRING DRIER AIR INTO THE AREA.
THE EXPECTED CLEARING LATE TONIGHT WITH THE HIGH PRESSURE RIDGE
MOVING INTO THE AREA SHOULD COMBINE WITH LIGHTER WINDS TO BRING A
WIDESPREAD FREEZE TO THE ENTIRE AREA...GIVEN EXPECTED LOWS IN THE
20S TO LOWER 30S LAKESIDE. THUS...THE FREEZE WARNING WAS EXPANDED
ACROSS THE ENTIRE AREA. MOSTLY SUNNY BUT COOL CONDITIONS ARE THEN
EXPECTED SUNDAY...WITH LOWER 50S FOR HIGHS.
SUNDAY NIGHT THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS
MEDIUM.
A MODERATELY STRONG 500MB SHORT WAVE WILL DROP FROM THE LAKE
WINNIPEG CANADA REGION LATE SUNDAY NIGHT...CLIPPING NORTHERN
MINNESOTA BEFORE ARCING BACK TO THE NORTH MONDAY NIGHT. THERE IS
AN ASSOCIATED TRAILING TROF THAT DOES STRETCH BACK TO THE
SOUTHWEST...INTO THE NRN TIER OF THE U.S. THE RESULTING SURFACE
CYCLOGENESIS IS FAIRLY RAPID...WITH A LOW DEEPENING AND MOVING
ALONG THE U.S. CANADIAN BORDER. WE GET INTO THE TIGHT PRESSURE
GRADIENT AHEAD OF THE LOW...CONTRASTED AGAINST HIGH PRESSURE OVER
THE EAST COAST. THIS PUSHES A NICE THERMAL RIDGE INTO THE
REGION...ALONG WITH BRISK/GUSTY WINDS. TEMPS SHOULD RISE INTO THE
LOWER AND MAYBE MID 60S. HOWEVER...THINGS ARE EXPECTED TO BE DRY
THROUGH THIS PERIOD.
MONDAY NIGHT THROUGH TUESDAY NIGHT...FORECAST CONFIDENCE IS
MEDIUM.
THE 500MB TROF THEN DIGS INTO THE GREAT LAKES AS ANOTHER SHOT OF
ENERGY DIVES INTO THE BACK SIDE OF THE LEAD SHORT WAVE MENTIONED
ABOVE. THIS FINALLY KICKS OUT THE SFC LOW WITH THE TRAILING COLD
FRONT SWEEPING THROUGH THE AREA TUESDAY INTO TUESDAY NIGHT. THE
MODELS ARE IN PRETTY GOOD AGREEMENT HERE WITH DRAGGING SOME LIGHT
QPF ACROSS THE AREA. A LITTLE CONCERNED THOUGH ABOUT THE EVENTUAL
MOISTURE PROFILE WITH THE FRONTAL PASSAGE. THERE IS SOME LACK OF
MOISTURE IN THE LOWER LEVELS...AND WITH THE PARENT LOW SO FAR TO
THE NORTH...WE COULD SEE SOME WEAKENING OF FORCING/LIFT. PREFER TO
WAIT ANOTHER CYCLE BEFORE UPPING POPS ANY HIGHER.
WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT. COOLER LOW TO MID 50S
EXPECTED WITH SOME SUNSHINE.
THURSDAY AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
ANOTHER WEAK SFC LOW PASSES ACROSS THE NORTHERN GREAT LAKES ON
THURSDAY...DRAGGING A WEAK...BUT DRY...COLD FRONT THROUGH HERE
LATE IN THE DAY ON THURSDAY. HIGH PRESSURE BUILDS BACK IN FOR
FRIDAY.
SATURDAY...FORECAST CONFIDENCE IS LOW TO MEDIUM.
THE GFS AND THE ECMWF ARE PERSISTENT AND CONSISTENT ON DEVELOPING
A VERY LARGE LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS ON
SATURDAY. THE SURGE OF WARMER AIR AND MOISTURE INTO THE REGION SHOULD
LEAD TO RAIN SPREADING ACROSS THE UPPER MIDWEST INTO THE WESTERN
GREAT LAKES DURING THE DAY ON SATURDAY...CONTINUING THROUGH
SATURDAY NIGHT. IT LOOKS LIKE A WET WEEKEND AT THIS POINT.
AVIATION/00Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH SUNDAY ACROSS TAF SITES. GUSTY
NORTHWEST WINDS SHOULD SUBSIDE BY SUNSET...WITH LIGHT NORTHWEST
WINDS OVERNIGHT AS HIGH PRESSURE PASSES WELL SOUTHWEST OF THE
REGION. EXPECT BROKEN TO OVERCAST CLOUDS TO LINGER THROUGH EARLY TO
MID EVENING...BEFORE GRADUALLY MIXING OUT LATE THIS EVENING AND
OVERNIGHT. LIGHT WEST WINDS IN THE MORNING WILL SHIFT SOUTHWEST
SUNDAY AFTERNOON...UNDER MOSTLY SUNNY SKIES.
MARINE...
A TIGHT PRESSURE GRADIENT WILL DEVELOP ACROSS THE REGION LATE SUNDAY
NIGHT AND LINGER INTO MONDAY NIGHT/TUESDAY MORNING...BEFORE A COLD
FRONT MOVES THROUGH THE AREA. SOUTHWEST WINDS WILL BECOME GUSTY
DURING THIS TIME. SOME GUSTS WILL APPROACH GALE FORCE AT TIMES. HIGH
WAVES WILL BE LIMITED TOWARD THE OPEN WATERS...GIVEN THE OFFSHORE
FLOW. A SMALL CRAFT ADVISORY OR GALE WATCH MAY BE NEEDED FOR THIS
PERIOD IN LATER FORECASTS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR WIZ046-047-051-
052-056>060-062>072.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/SUNDAY AND AVIATION/MARINE...WOOD
SUNDAY NIGHT THROUGH SATURDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
632 PM CDT SAT OCT 6 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
252 PM CDT SAT OCT 6 2012
MAIN FORECAST CONCERNS ARE ON FREEZE POTENTIAL TONIGHT...NEAR
CRITICAL FIRE WEATHER CONDITIONS SUNDAY AND MONDAY...AND FINALLY
PRECIPITATION CHANCES FOR MONDAY NIGHT AND TUESDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED RIDGING OVER THE NORTHEAST PACIFIC AND ALONG THE
WEST COAST OF THE U.S....WHILE DEEP TROUGHING WAS PRESENT OVER
CENTRAL AND EASTERN CANADA SOUTHWARD INTO THE CENTRAL PLAINS AND
OHIO RIVER VALLEY. WITHIN THE TROUGHING...A SHORTWAVE TROUGH
EXTENDED EAST-WEST ACROSS THE FORECAST AREA AND WEST TOWARDS
NEBRASKA. UNDERNEATH THIS SHORTWAVE TROUGH WAS AN AREA OF BROKEN
STRATUS ACROSS THE FORECAST AREA TO NEAR DULUTH. MUCH OF THIS
STRATUS WAS SITUATED AT 750MB OR BELOW PER 12Z SOUNDINGS FROM
INL...MPX AND GRB. THE REASON THE DECK IS NOT A SOLID OVERCAST IS
THAT THE SOUNDINGS DO NOT SHOW COMPLETE SATURATION. IN FACT...SOME
OF THE STRATUS FORMATION HAS BEEN DUE TO DAYTIME HEATING...NOTED
BY HOLES THAT FILLED IN DURING THE MORNING. FARTHER TO THE
NORTHWEST ON WATER VAPOR...A SHORTWAVE TROUGH WAS EVIDENT IN
SOUTHERN SASKATCHEWAN DROPPING DOWN THE EAST SIDE OF THE NORTHEAST
PACIFIC RIDGE. LACK OF LOW LEVEL MOISTURE SEEN ON THE 12Z THE PAS
MANITOBA SOUNDING HAS RESULTED IN THE SHORTWAVE JUST PRODUCING A
BAND OF MID AND HIGH CLOUDS. AT THE SURFACE...HIGH PRESSURE WAS
SITUATED OVER THE CENTRAL PLAINS WITH A RIDGE AXIS EXTENDING
NORTHEAST INTO NORTHERN MINNESOTA. 850MB TEMPS CHILLY OVER THE
FORECAST AREA...BETWEEN -5 AND -7C PER 12Z RAOBS...OR 2 STANDARD
DEVIATIONS BELOW NORMAL.
TONIGHT AND SUNDAY...SHORTWAVE TROUGH OVER SOUTHERN SASKATCHEWAN IS
PROGGED TO KEEP DROPPING SOUTHEAST THROUGH THE DEEP UPPER TROUGH...
CROSSING THE FORECAST AREA SUNDAY AFTERNOON. THIS TROUGH WILL DO A
COUPLE OF THINGS. FIRST...THE SURFACE RIDGE AXIS OVER MINNESOTA
WILL GET PUSHED DOWN OVER THE FORECAST AREA TONIGHT. AS THE RIDGE
AXIS AND THE DRY AIR ASSOCIATED WITH IT MOVE IN...SKIES WILL
CLEAR. WINDS SHOULD DECOUPLE AS WELL...EXCLUDING THE HIGHER
TERRAIN OF SOUTHEAST MINNESOTA. GIVEN THE COOL DAY TODAY...THE
SETUP CERTAINLY FAVORS LOWS DROPPING INTO THE 20S AS HAS BEEN
FORECAST THE PAST FEW DAYS. SOME OF THE TYPICAL COLD SPOTS IN
WISCONSIN COULD EVEN HIT THE UPPER TEENS. FREEZE WARNINGS
THEREFORE STILL LOOK GOOD WITH THIS LIKELY BEING THE END OF THE
GROWING SEASON. THE SECOND THING THE SHORTWAVE TROUGH WILL DO IS
TO SPREAD THE CIRRUS AND SOME MID CLOUDS SEEN UP IN SOUTH CENTRAL
CANADA ACROSS THE FORECAST AREA. REGARDING TEMPERATURES...
DOWNSLOPING OF AIR OFF THE ROCKIES AHEAD OF THE SHORTWAVE TROUGH
WILL ALLOW A PLUME OF WARMER 925-850MB AIR TO ADVECT INTO THE
FORECAST AREA. BY 18Z... 925MB AND 850MB TEMPS RISE TO 2-4C AND -3
TO -5C RESPECTIVELY. COMBINE THESE WITH AN INCREASING SOUTHWEST
WIND AS THE SURFACE RIDGE DROPS SOUTH AND HIGHS SHOULD BE ABLE TO
REACH INTO THE LOW TO MID 50S. DRY DEWPOINTS IN THE TEENS WILL
HELP RELATIVE HUMIDITIES PLUMMET INTO THE 20-30 PERCENT
RANGE...RAISING SOME FIRE WEATHER CONCERNS. THESE ARE NOTED IN THE
FIRE WEATHER DISCUSSION BELOW.
SUNDAY NIGHT AND MONDAY...ATTENTION TURNS TO A SHORTWAVE CURRENTLY
WELL UP TO THE NORTHWEST...NEAR THE NORTHWEST CORNER OF THE
NORTHWEST TERRITORIES. MODELS HAVE BEEN VERY CONSISTENT OF DROPPING
THIS SHORTWAVE INTO THE DEEP TROUGH...REACHING SOUTHERN PORTIONS OF
SASKATCHEWAN AND MANITOBA BY 12Z MONDAY. AS THE SHORTWAVE DROPS
SOUTH...A DEEPENING SURFACE LOW ACCOMPANIES IT...WHICH SHOULD REACH
FAR SOUTHERN MANITOBA BY 12Z MONDAY. THIS DEEPENING LOW WILL HELP TO
INCREASE THE SOUTHWEST WINDS EVEN MORE OVER THE FORECAST AREA...AND
ALSO ENHANCE THE DOWNSLOPE EFFECT OFF THE ROCKIES. AS SUCH...925 AND
850MB TEMPS CLIMB TO 6C AND 4C RESPECTIVELY AT 12Z MONDAY. THIS WARM
ADVECTION IS LIKELY TO RESULT AN INCREASE OF MID AND HIGH CLOUDS...
ESPECIALLY AFTER MIDNIGHT SUNDAY NIGHT AND HEADING INTO THE DAY
MONDAY. THESE CLOUDS COMBINED WITH THE WINDS WILL HELP PRODUCE A
MUCH WARMER NIGHT...ALBEIT STILL BELOW NORMAL...MAINLY IN THE 30S.
AFTER 12Z MONDAY...MODELS DIFFER A BIT ON THE TRACK...DEPTH AND
SPEED OF THE SHORTWAVE TROUGH AND SURFACE LOW. OVERALL...THOUGH...
THE GENERAL THEME IS FOR THE SHORTWAVE AND SURFACE LOW TO HEAD
EAST...LIKELY ALONG THE ONTARIO/MN BORDER. COLD FRONT ASSOCIATED
WITH THE LOW STAYS TO OUR WEST...ONLY REACHING ALBERTA LEA BY 00Z.
925MB AND 850MB TEMPS CONTINUE TO WARM AHEAD OF THIS FRONT...TOPPING
OUT AT 12-14C AND 6-8C RESPECTIVELY. WITH A TIGHT PRESSURE GRADIENT
AND MIXING RESULTING IN BREEZY SOUTHWEST WINDS...ALONG WITH DRY LOW
LEVEL AIR...WE SHOULD BE ABLE TO MIX TO NEAR 850MB. ONLY CAVEAT IS
THE MID/HIGH CLOUDS...WHICH LOOK TO INCREASE AND THICKEN THROUGH THE
DAY. ANY PRECIPITATION WITH THESE CLOUDS SHOULD STAY NORTH OF THE
FORECAST AREA PER MODEL CONSENSUS. HIGHS IN THE 60S STILL ARE
REASONABLE...PERHAPS GETTING CLOSE TO 70 WEST OF THE MISSISSIPPI
RIVER. FIRE WEATHER CONCERNS EXIST AGAIN WITH THE BREEZY SOUTHWEST
WINDS...TEMPERATURES AND LOW RELATIVE HUMIDITIES. SEE FIRE WEATHER
DISCUSSION BELOW.
MONDAY NIGHT AND TUESDAY...MODELS SHOW YET ANOTHER FAIRLY STRONG
SHORTWAVE DROPPING DOWN THE EAST SIDE OF THE NORTHEAST PACIFIC
RIDGE...DIGGING INTO NORTH DAKOTA BY 12Z TUESDAY AND THEN INTO
SOUTHERN MINNESOTA BY 00Z WEDNESDAY. THIS SHORTWAVE SHOULD HELP TO
ENHANCE LIFT IN THE WAKE OF THE COLD FRONT...ON TOP OF THE
POST-FRONTAL MID LEVEL FRONTOGENESIS THAT WILL ALREADY EXIST. SO
ONCE THE COLD FRONT MOVES EAST THROUGH THE FORECAST AREA...WHICH
GRADUALLY OCCURS DURING THIS PERIOD UNTIL THIS SHORTWAVE CAN CATCH
UP...ANTICIPATE A BAND OF RAIN TO DEVELOP. THIS SIGNAL OF THE BAND
OF RAIN CONTINUES TO GET STRONGER...WITH THE 06.12Z GFS...NAM...
UKMET...CANADIAN AND ECMWF ALL DEPICTING IT. AS SUCH...HAVE RAISED
PRECIPITATION CHANCES UP TO AROUND 40. FURTHER INCREASES WILL LIKELY
BE NEEDED IF THIS SIGNAL PERSISTS. PRECIPITABLE WATER VALUES ARE
ONLY AROUND 0.75 OF AN INCH...SO MOISTURE IS NOT THAT GREAT...BUT
THE FORCING SHOULD BE ABLE TO SQUEEZE OUT SOME LIGHT PRECIPITATION.
WITH PLENTY OF CLOUDS MONDAY NIGHT AND THE SLOW COLD FRONTAL
PASSAGE...LOWS IN THE 40S SUGGESTED BY MAV/MET GUIDANCE SEEM
REASONABLE. 850MB TEMPS DO GRADUALLY FALL DURING THE DAY
TUESDAY...BOTTOMING OUT AROUND 0C BY 00Z. NEVERTHELESS...HIGHS
SHOULD BE ABLE TO TOP OUT IN THE 50S...COOLEST IN THE NORTHWEST
WHICH ENDS UP MOSTLY BEHIND THE FRONT FOR THE ENTIRE DAY.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
252 PM CDT SAT OCT 6 2012
GOOD MODEL AGREEMENT EXISTS BETWEEN THE 06.12Z ECMWF/GFS/CANADIAN
AND GFS ENSEMBLES ABOUT A PATTERN SHIFT OCCURRING DURING THE LONG
TERM FORECAST...WITH THE CURRENT DEEP TROUGH LIFTING OUT ON FRIDAY.
WE STILL HAVE ONE MORE POTENT SHORTWAVE TO DEAL WITH DROPPING THE
TROUGH PRIOR TO LIFT-OUT...PROGGED TO CROSS LAKE SUPERIOR LATE
THURSDAY. AFTER FRIDAY...MODELS SHOW AN UPPER LOW...CURRENTLY JUST
OFF THE COAST OF CALIFORNIA...LIFTING OUT OF THE SOUTHWESTERN U.S..
EXACTLY HOW FAST THIS EJECTION OCCURS THE MODELS ARE ALL OVER THE
PLACE...WITH THE LATEST 06.12Z GFS THE FASTEST AMONGST ALL MODELS
AND PAST 1-2 DAYS OF RUNS OF THE MODEL. THE GFS HAS THIS DEEP LOW
LIFTING UP INTO SOUTHERN MINNESOTA BY 00Z SUNDAY. EJECTING UPPER
LOWS OUT OF THE SOUTHWESTERN U.S. ARE ALWAYS PROBLEMATIC FOR
MODELS...SINCE THEY HINGE ON UPPER TROUGHS CROSSING THE PACIFIC.
THEREFORE...HAVE LOW CONFIDENCE ON ANY SOLUTION AT THIS POINT...
THOUGH IT WOULD NOT BE SURPRISING IF A SLOWER IDEA ENDS UP PANNING
OUT PER MODEL BIASES.
IN THE WAKE OF TUESDAYS SHORTWAVE...A RIDGE OF HIGH PRESSURE IS
FORECAST TO BUILD IN FOR WEDNESDAY. ANOTHER SHOT OF COOL AIR COMES
WITH THIS RIDGE WITH 850MB TEMPS FALLING TO AROUND -4C. THUS...
TUESDAY NIGHT AND WEDNESDAY WILL BE COOL...BUT NOT NEARLY AS COLD AS
TODAY OR TONIGHT. COULD BE SOME LINGERING PRECIP TUESDAY EVENING IN
THE SOUTHEASTERN THIRD OF THE AREA...ASSOCIATED WITH TUESDAYS
SHORTWAVE...OTHERWISE EXPECT DRY CONDITIONS. WITH THE THURSDAY
SHORTWAVE DROPPING DOWN INTO LAKE SUPERIOR...WE GET ANOTHER COLD
FRONT TO MOVE THROUGH THE FORECAST AREA. DUE TO LIMITED SPACING
BETWEEN THE CANADIAN RIDGE OF HIGH PRESSURE AND THIS FRONT...NOT
ANTICIPATING ANY POST-FRONTAL PRECIPITATION. AHEAD OF THE FRONT...A
SURGE OF 4-6C 850MB AIR IS PROGGED TO COME INTO THE AREA ON STRONG
SOUTHWEST WINDS. SO WE COULD HAVE ANOTHER NEAR CRITICAL FIRE WEATHER
DAY...PARTICULARLY SOUTH OF I-90. ANOTHER COOLER HIGH PRESSURE AREA
IS SLATED TO DROP DOWN INTO OUR REGION FOR FRIDAY...WITH 850MB TEMPS
DROPPING BACK TO AROUND -4C AT 12Z. FOR FRIDAY NIGHT AND SATURDAY...
HAVE FOLLOWED THE CONSENSUS APPROACH AND SPREADING CHANCES OF
PRECIPITATION INTO THE AREA FROM THE SOUTHWEST. THESE ARE ALL DUE TO
WARM...MOIST AIR ADVECTION OUT OF THE GULF OF MEXICO COMING INTO THE
COLDER AIRMASS SITUATED OVER THE FORECAST AREA. MORE REFINEMENT OF
THESE CHANCES WILL COME DURING THE NEXT SEVERAL DAYS AS TIMING OF
THE UPPER LOW EJECTION BECOMES MORE CERTAIN. SHOULD SEE A GRADUAL
WARM UP IN TEMPERATURES TOO WITH THE WARMER AIR ADVECTING INTO THE
AREA. HIGHS BY SATURDAY STILL LOOK BELOW NORMAL BUT ONLY 5 OR SO
DEGREES...NOT LIKE THE 15-20 AS OF LATE.
&&
.AVIATION...TONIGHT AND SUNDAY
632 PM CDT SAT OCT 6 2012
SURFACE HIGH PRESSURE WILL BUILD EASTWARD INTO THE AREA OVERNIGHT
TONIGHT. EXPECT THE VFR CEILINGS TO BREAK UP OVER THE TAF SITES
THROUGH THE EVENING HOURS AS DRIER AIR ADVECTS INTO THE REGION
FROM THE NORTHWEST. WINDS WILL ALSO CONTINUE DIMINISH AS THE
GRADIENT RELAXES. EXPECT THE VFR CONDITIONS TO PREVAIL THROUGH THE
REMAINDER OF THE TAF PERIOD WITH JUST SOME HIGH CLOUDS SUNDAY
AFTERNOON.
&&
.FIRE WEATHER...SUNDAY INTO MONDAY
252 PM CDT SAT OCT 6 2012
NEAR CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE BOTH SUNDAY AND
MONDAY. SETTING THE STAGE FOR THESE CONDITIONS IS THE MODERATE TO
EXTREME DROUGHT CONDITIONS IN PLACE ACROSS THE AREA...ALONG WITH A
KILLING FREEZE EXPECTED TONIGHT.
FOR SUNDAY...SOUTHWEST WINDS ARE EXPECTED TO INCREASE IN THE WAKE OF
A RIDGE OF HIGH PRESSURE DROPPING SOUTH ACROSS THE AREA TONIGHT.
THESE WINDS SHOULD BE SUSTAINED IN THE 10-15 MPH RANGE WITH GUSTS OF
12-22 MPH...STRONGEST ACROSS SOUTHEAST MINNESOTA. DEWPOINTS ARE
LIKELY TO STILL BE LOW...THANKS TO MIXING OF DRY AIR ALOFT AND THE
RECENT COLD NIGHT. HOWEVER...LINGERING COLD AIR THAT ONLY SLOWLY
MODIFIES WILL ONLY ALLOW HIGH TEMPERATURES TO TOP OUT IN THE LOW TO
MID 50S. THESE TEMPERATURES COMBINED WITH THE DEWPOINTS SHOULD
PRODUCE MINIMUM RELATIVE HUMIDITIES IN THE 20-30 PERCENT RANGE...
LOWEST SOUTH AND WEST OF I-94. THEREFORE...THE MAIN LIMITING FACTORS
FOR RED FLAG CONDITIONS WOULD BE THE TEMPERATURES AND WINDS.
FOR MONDAY...A STRENGTHENING LOW PRESSURE SYSTEM DROPPING SOUTH OUT
OF CENTRAL CANADA INTO NORTHERN MINNESOTA WILL RESULT IN A TIGHTER
PRESSURE GRADIENT ACROSS THE AREA. AS SUCH...STRONGER WINDS ARE
ANTICIPATED...IN THE 15-25 MPH RANGE WITH GUSTS OF 20-35 MPH.
HIGHEST WINDS ARE LIKELY WEST OF THE MISSISSIPPI RIVER. THESE WINDS
SHOULD BRING UP A LITTLE MORE MOISTURE...BUT HIGH TEMPERATURES WILL
MOSTLY COUNTERACT IT BY JUMPING INTO THE 60S. THEREFORE...MINIMUM
RELATIVE HUMIDITIES ARE ONLY SLIGHTLY HIGHER...BETWEEN 25-35
PERCENT...LOWEST ALONG/WEST OF THE MISSISSIPPI RIVER. GIVEN THE
SLIGHTLY HIGHER MINIMUM RELATIVE HUMIDITIES...TEMPERATURES STILL
SLIGHTLY COOL AND ESPECIALLY POTENTIAL FOR A LOT OF CLOUDS...
CONDITIONS AGAIN JUST LOOK NEAR CRITICAL. THE CLOUDS COULD BE
QUITE PROBLEMATIC BY KEEPING RELATIVE HUMIDITIES HIGHER THAN
EXPECTED.
PER COORDINATION WITH AREA FIRE WEATHER AGENCIES...HAVE HELD OFF
ON ANY FIRE WEATHER WATCHES AT THIS TIME.
LOOKING AHEAD...ANOTHER NEAR CRITICAL FIRE WEATHER DAY COULD OCCUR
SOUTH OF I-90 ON THURSDAY...AHEAD OF A CANADIAN COLD FRONT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
252 PM CDT SAT OCT 6 2012
WI...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR WIZ032-033-041-
053>055-061.
MN...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR MNZ079-088-096.
IA...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR IAZ011-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1154 PM CDT THU OCT 4 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
257 PM CDT THU OCT 4 2012
MAIN FORECAST CONCERNS ON BREEZY NORTHWEST WINDS THIS EVENING AND
AGAIN ON FRIDAY. FOCUS THEN TURNS TO LOW PRECIPITATION CHANCES ON
SATURDAY AND TEMPERATURES THROUGH THE WEEKEND.
LATEST WATER VAPOR IMAGERY SHOWED A POTENT LOW PRESSURE SYSTEM OVER
NORTHERN MINNESOTA RESPONSIBLE FOR PRODUCING HEAVY...WET SNOW OVER
PORTIONS OF NORTHWEST MINNESOTA. SURFACE OBSERVATIONS INDICATED A
TIGHT PRESSURE GRADIENT OVER THE FORECAST AREA IN THE WAKE OF A
COLD FRONT THAT MOVED THROUGH THIS MORNING. THE TIGHT GRADIENT AND
COLD AIR ADVECTION BEHIND THE FRONT WAS KEEPING BREEZY
WEST/NORTHWEST ACROSS THE FORECAST AREA.
THE LOW IS EXPECTED TO LIFT NORTHEAST TONIGHT INTO SOUTHWEST ONTARIO
AND MEANDER EAST...JUST NORTH OF LAKE SUPERIOR. A TIGHT PRESSURE
GRADIENT WILL REMAIN IN PLACE OVER THE AREA AS THE REGION IS IN
BETWEEN THE LOW PASSING TO THE NORTH AND HIGH PRESSURE ATTEMPTING
TO BUILD INTO THE DAKOTAS. THIS WILL KEEP BREEZY CONDITIONS
THROUGH THIS EVENING. WINDS WILL TAPER OFF LATE IN THE EVENING FOR
LOCATIONS ALONG AND SOUTH OF INTERSTATE 90. NAM AND RUC LOW LEVEL
RELATIVE HUMIDITY FIELDS SHOWS A SCATTERED TO BROKEN STRATUS DECK
MOVING IN FROM THE NORTHWEST THIS EVENING AND MAKING IT TO ABOUT
THE INTERSTATE 90 CORRIDOR. HAVE INCREASED CLOUD COVER THIS
EVENING INTO THE OVERNIGHT HOURS ACROSS THESES AREAS. LOOK FOR LOW
TEMPERATURES TO FALL INTO THE 30S TONIGHT.
AN UPPER TROUGH WILL DIVE SOUTH INTO THE DAKOTAS AND NORTHERN
MINNESOTA ON FRIDAY OUT OF SOUTHERN MANITOBA...SASKATCHEWAN AND
ALBERTA AS THE LOW FILLS AND LIFTS NORTHEAST OVER JAMES BAY. PLAN ON
CONTINUED BREEZY NORTHWEST WINDS ACROSS THE AREA ON FRIDAY AS THE
PRESSURE GRADIENT REMAINS TIGHT. WIND SPEEDS ARE EXPECTED TO RANGE
FROM 14 TO 24 MPH. SOME GUSTS IN THE 25 TO 30 MPH RANGE ARE
POSSIBLE IN OPEN AREAS. THE GRADIENT WILL REMAIN TIGHTER THOUGH
THE DAY ACROSS CENTRAL INTO NORTH CENTRAL WISCONSIN SO HAVE
INCREASED WINDS GUSTS SLIGHTLY ACROSS THESE AREAS. HIGH
TEMPERATURES WILL RANGE FROM THE LOWER 40S ACROSS NORTHERN
WISCONSIN TO THE LOWER 50S OVER NORTHEAST IOWA. THE TROUGH IS
EXPECTED TO PUSH SOUTH INTO CENTRAL MINNESOTA AND NORTHERN
WISCONSIN LATE FRIDAY NIGHT INTO SATURDAY MORNING. CLOUDS WILL BE
ON THE INCREASE FROM NORTH TO SOUTH AS THE TROUGH MOVES IN. CANNOT
RULE OUT A LIGHT SPRINKLE OR SNOW SHOWER FRIDAY NIGHT INTO
SATURDAY MORNING ALONG AND NORTH OF THE INTERSTATE 94 CORRIDOR.
FORECAST SOUNDING ARE NOT SHOWING ENOUGH SATURATION FOR ICE ALOFT
SO THE PRECIPITATION COULD FALL AS SPRINKLES OR POSSIBLY FREEZING
SPRINKLES DEPENDING ON SURFACE TEMPERATURES. THERE APPEARS TO BE
ENOUGH SATURATION FOR PRECIPITATION BUT THERE REALLY IS NOT
APPRECIABLE LIFT SO CONCERNED THAT THE MAIN IMPACT FROM THE TROUGH
WILL BE JUST INCREASING STRATUS AND NO PRECIPITATION. WILL
MAINTAIN SLIGHT CHANCES FOR RAIN/SNOW SHOWERS OVER NORTH CENTRAL
WISCONSIN. PLAN ON LOW TEMPERATURES RANGING FROM THE UPPER 20S TO
LOWER 30S OVER NORTH CENTRAL WISCONSIN TO THE LOWER 30S OVER
NORTHEAST IOWA. GUIDANCE HAS BEEN TRENDING COOLER FRIDAY NIGHT BUT
CONCERNED THAT THE INCREASING CLOUD COVER AND PERSISTENT NORTHWEST
WINDS WILL LEAD TO SLIGHTLY WARMER TEMPERATURES. WILL HAVE TO KEEP
A CLOSE WATCH ON THE PROGRESSION OF THE STRATUS DECK FRIDAY NIGHT
AND WINDS. LOCATIONS THAT REMAIN CLEAR AND DECOUPLE COULD SEE
TEMPERATURES PLUMMET INTO THE MID 20S.
SATURDAY WILL BE A RATHER CHILLY FALL DAY ACROSS THE REGION. THE
TROUGH WILL CONTINUE ITS SOUTHWARD PUSH...LEADING TO AN EXPANSIVE
STRATUS DECK ACROSS MUCH OF THE FORECAST AREA. DECIDED TO MAINTAIN A
SLIGHT CHANCE FOR RAIN/SNOW SHOWERS OVER NORTH CENTRAL WISCONSIN AS
THE TROUGH MOVES THROUGH DURING THE MORNING HOURS. HAVE INCLUDED A
CHANCE OF FLURRIES ACROSS WEST CENTRAL WISCONSIN INTO SOUTHEAST
MINNESOTA AND NORTHEAST IOWA EARLY SATURDAY MORNING...THEN SWITCHED
OVER TO SPRINKLES LATE IN THE MORNING AS TEMPERATURES WARM. SEEING
THE SATURATION FOR SOME PRECIPITATION IN THE FORECAST SOUNDINGS BUT
VERY MINIMAL LIFT. THINKING THE TROUGH SHOULD BE ABLE TO PRODUCE
SOME VERY LIGHT PRECIP AS IT MOVES THROUGH. OTHERWISE...PLAN ON A
MOSTLY CLOUDY AND COOL DAY WITH HIGHS RANGING FROM THE LOWER 40S
OVER NORTHERN WISCONSIN TO THE UPPER 40S ACROSS NORTHEAST IOWA.
SATURDAY INTO SATURDAY NIGHT...850 MB TEMPERATURE STANDARDIZED
ANOMALIES WILL FALL TO AROUND -1.5 C BASED ON THE ECMWF....WHILE
THE NAM IS SUGGESTING -2.0 C. ANOMALIES THIS LOW SUGGEST THE
POTENTIAL FOR NEAR RECORD LOW TEMPERATURES ACROSS THE REGION. THE
COLD AIRMASS OVER THE REGION AND CLEARING SKIES LATE SATURDAY
NIGHT INTO EARLY SUNDAY MORNING WILL LEAD TO NEAR RECORD LOW
TEMPERATURES AND A HARD...GROWING SEASON ENDING FREEZE...WITH LOWS
FALLING INTO THE 20S. A FREEZE WARNING WILL BE NEEDED LATE
SATURDAY NIGHT INTO EARLY SUNDAY MORNING. SURFACE HIGH PRESSURE
WILL EDGE INTO THE REGION ON SUNDAY WITH MOSTLY SUNNY SKIES
EXPECTED. AFTER A COLD START TO THE DAY...LOOK FOR HIGH
TEMPERATURES TO REBOUND INTO THE UPPER 40S OVER NORTHERN WISCONSIN
TO THE LOWER 50S ACROSS NORTHEAST IOWA.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
257 PM CDT THU OCT 4 2012
04.12 MEDIUM RANGE MODELS IN REASONABLE AGREEMENT THROUGH THE
EXTENDED PERIOD. NORTHWEST FLOW ALOFT WILL CONTINUE INTO SUNDAY
NIGHT WITH SURFACE HIGH PRESSURE IN CONTROL. THE HIGH IS EXPECTED TO
SLIDE EAST OF THE AREA MONDAY AS A COLD FRONT DRIFTS SOUTH ACROSS
NORTHERN MINNESOTA INTO SOUTHERN NORTH DAKOTA. MEANWHILE...AN UPPER
TROUGH WILL MOVE THROUGH MONTANA AND INTO WESTERN NORTH DAKOTA.
SOUTHWEST FLOW AHEAD OF THE APPROACHING FRONT WILL HELP TEMPERATURES
CLIMB INTO THE UPPER 50S TO LOWER 60S ACROSS THE FORECAST AREA
MONDAY AFTERNOON. THE FRONT IS EXPECTED TO PUSH SOUTH INTO NORTHERN
WISCONSIN LATE MONDAY NIGHT BRINGING A SLIGHT CHANCE OF RAIN SHOWERS
TO NORTH CENTRAL WISCONSIN. THE FRONT WILL CONTINUE TO MOVE SOUTH
DURING THE DAY ON TUESDAY BRINGING A SLIGHT CHANCE OF RAIN SHOWERS
TO MUCH OF THE FORECAST AREA. HIGH PRESSURE IS EXPECTED TO BUILD
BACK INTO THE UPPER MISSISSIPPI RIVER VALLEY WEDNESDAY INTO THURSDAY
PROVIDING DRY AND QUIET WEATHER. LOOK FOR HIGH TEMPERATURES IN THE
50S ON WEDNESDAY...CLIMBING INTO THE MID 50S TO LOWER 60S THURSDAY
AFTERNOON.
&&
.AVIATION...THROUGH 06Z SATURDAY
1154 PM CDT THU OCT 4 2012
THE VFR STRATUS DECK NORTH OF THE TAF SITES EARLIER THIS EVENING
DID MAKE IT INTO THE TAF SITES LATE THIS EVENING. WESTERLY WINDS
CONTINUE TO GUST UPWARDS OF 20 TO 25 KNOTS AT BOTH SITES. EXPECT
CEILINGS OF 035K-040K FOOT TO PERSIST THROUGH THE OVERNIGHT HOURS.
LATEST SATELLITE TRENDS DOES SHOW SOME ERODING OF THE CLOUDS ALONG
THE SOUTHERN FLANK...SO TAF SITES MAY REMAIN ON THE EDGE. WINDS
WILL REMAIN STRONG OVERNIGHT WITH SOME GUSTS CONTINUING IN THE 20
TO 25 KNOT RANGE. STRATUS SHOULD MIX OUT FRIDAY AFTER 15Z WITH
PRESSURE GRADIENT REMAINING TIGHT AND WINDS CONTINUING TO GUST
UPWARDS OF 25 KNOTS. ANOTHER SURFACE TROUGH DROPS SOUTHWARD
THROUGH NORTHERN MINNESOTA AFTER 00Z SATURDAY. NAM IS SHOWING A
SOUTHWARD PUSH OF 850MB-925MB MOISTURE TOWARDS THE TAF SITES.
TIMING AT THIS TIME LOOKS TO BE AROUND OR JUST AFTER 06Z...SO WILL
JUST KEEP MENTION OF A SCATTERED DECK AT THIS TIME....BUT WILL
LIKELY SEE SOME CEILINGS DEVELOP AFTER 06Z IN THE UPPER MVFR LOWER
VFR CATEGORY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
257 PM CDT THU OCT 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS DENVER CO
333 AM MDT SUN OCT 7 2012
.SHORT TERM...NNW FLOW ALOFT WILL BE OVER THE AREA THRU TONIGHT
WITH DRY CONDITIONS EXPECTED. MAIN CONCERN FOR THIS MORNING WILL
BE FOG POTENTIAL OVER NERN CO. SO FAR THE ONLY PALCE WITH FOG IS
OVER THE FAR NERN CORNER WHERE SKIES HAVE BEEN CLEAR OVERNIGHT.
CLOSER TO THE FRONT RANGE LOW LVL CLOUDS HAVE REMAINED IN PLACE
BUT HAVE BEEN SLOWLY DIMINISHING THE LAST FEW HOURS. AT THIS TIME
WILL KEEP AREAS OF FOG OVER THE PLAINS WHERE SKIES HAVE BEEN
GENERALLY CLEAR AND ONLY MENTION PATCHY FOG CLOSER TO THE
FOOTHILLS. AS FAS AS AFTN HIGHS WILL KEEP HIGHS IN THE LOWER TO
MID 50S ACROSS NERN CO FOR THIS AFTN. FOR TONIGHT SHOULD SEE
MAINLY CLEAR SKIES. MAY SEE SOME GUSTY WINDS IN THE MTNS AND
HIGHER FOOTHILLS LATE TONIGHT AS A WK MTN WAVE DEVELOPS.
.LONG TERM...NORTHERN COLORADO WILL BE UNDER A MODERATE NORTHWEST
FLOW PATTERN THROUGH MIDWEEK WITH A DRY AIRMASS IN PLACE. THERE
WILL BE A WEAK TROF WHICH MOVES THROUGH THE NORTHERN PLAINS STATES
ON TUESDAY. THERE WILL BE AN ASSOCIATED COLD FRONT WHICH WILL COOL
TEMPERATURES ACROSS NORTHEAST COLORADO ON TUESDAY AS LOW LEVEL
INVERSIONS REMAIN IN PLACE. LATEST NAM BRINGS IN SOME LOW LEVEL
MOISTURE AND POTENTIAL STRATUS OVER THE PLAINS WHILE THE GFS AND
EUROPEAN ARE DRY. APPEARS MOST OF THE MOISTURE WITH THIS SYSTEM WILL
BE TOO FAR NORTH AND EAST OF COLORADO FOR ANY BENEFIT. WARMER
AGAIN ON WEDNESDAY AS HEIGHTS BUILD AS TEMPERATURES RETURN CLOSE
TO CLIMATE NORMALS FOR THIS TIME OF YEAR.
THE NEXT WEATHER MAKER WILL BE CLOSED LOW WHICH WILL BE OFF THE
SOUTHERN CALIFORNIA COAST BY THURSDAY WHICH WILL RESULT IN SOME
DOWNSTREAM RIDGING ACROSS COLORADO. THE FLOW ALOFT WILL SHIFT WEST
TO SOUTHWEST THURSDAY AND FRIDAY AS MOISTURE VALUES SLOWLY
ELEVATE. THE LOW IS PROGGED TO EJECT INTO COLORADO SOMETIME IN THE
FRIDAY THROUGH SATURDAY TIME FRAME DEPENDING ON WHICH MODEL.
SOLUTIONS VARY FROM THE SLOWER GFS SOLUTION TO THE FASTEST
EUROPEAN. SEEMS LIKE THERE IS EVEN MORE VARIATION IN THE SOLUTIONS
TODAY COMPARED TO YESTERDAY SO FORECAST CONFIDENCE NOT VERY HIGH.
TYPICALLY THESE SYSTEMS END UP BEING SLOWER THAN FORECAST. NO
MAJOR CHANGES PLANNED IN UPCOMING FORECAST PACKAGE FOR THE LONG
TERM AND WILL KEEP LOW POPS FOR THE ENTIRE AREA ON FRIDAY AND SATURDAY.
&&
.AVIATION...SO FAR THE HRRR AND THE RAP ARE NOT REAL EXCITED ABOUT
LIFR CONDITIONS IN THE 10Z-15Z TIME PERIOD AS BOTH KEEP LIFR
CONDITIONS TO THE NE OF THE AIRPORT. RAP STILL SHOWS A WEAK DENVER
CYCONE NR THE AIRPORT BY 12Z SO AM TEMPTED TO LEAVE IN A BRIEF 3
HR WINDOW FM 12Z-15Z FOR SOME LOWER CEILINGS AND FOG FOR NOW AS
SKIES HAVE STARTED TO CLEAR. FOR THIS AFTN AND TONIGHT EXPECT VFR
CONDITIONS. WINDS WILL BE LIGHT AND VARIABLE THIS MORNING AND THEN
BECOME LIGHT NLY BY AFTN. FOR TONIGHT WINBDS SHOULD BECOME
DRAINAGE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ038>051.
&&
$$
SHORT TERM...RPK
LONG TERM....ENTREKIN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS ALBANY NY
136 AM EDT SUN OCT 7 2012
.SYNOPSIS...
MUCH COOLER AIR WILL CONTINUE TO STREAM INTO OUR REGION
OVERNIGHT AS WEAK HIGH PRESSURE CRESTS ACROSS THE REGION. LOW
PRESSURE WILL MOVE ALONG A FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING US MORE UNSETTLED WEATHER FOR SUNDAY AFTERNOON INTO
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE REGION ON MONDAY AND
BRING FAIR AND SEASONABLE WEATHER FOR THE FIRST HALF OF THE WORK
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM EDT...A BAND OF LAKE EFFECT RAIN SHOWERS HAS
DEVELOPED OFF LAKE ONTARIO. WHILE THE MAJORITY OF THESE RAIN
SHOWERS ARE REMAINING CLOSE TO THE LAKESHORE AND ACROSS THE TUG
HILL...A FEW SHOWERS WILL MAKE IT INTO THE FAR WESTERN
ADIRONDACKS. AS THE FLOW SHIFTS...THIS BAND WILL GRADUALLY SHIFT
SOUTH...POSSIBLY AFFECTING PARTS OF THE WESTERN MOHAWK VALLEY BY
LATE TONIGHT. THIS IS BEING MODELED WELL BY THE LATEST HRRR AND
LOCAL WRF.
MEANWHILE...A SFC FRONTAL BOUNDARY CONTINUES TO MOVE TO THE SOUTH
AND EAST OF OUR AREA ACROSS EASTERN NEW ENGLAND AND DOWN OFF THE
MID ATLANTIC SEABOARD. MID AND HIGH LEVEL CLOUDS ARE ALREADY
BEGINNING TO STREAK INTO THE REGION FROM THE SOUTHWEST...AND WILL
CONTINUE TO INCREASE TOWARD DAYBREAK AS A WAVE OF LOW PRESSURE
DEVELOPS ALONG THE FRONTAL BOUNDARY TO OUR SOUTH.
MIN TEMPS OVERNIGHT WILL BE MUCH COOLER THAN RECENT NIGHTS.
HOWEVER...DUE TO SOME WIND PERSISTING...AND THE PROSPECTS FOR
INCREASING CLOUDS...HAVE RAISED FORECAST MINS A BIT...WITH
LOWS GENERALLY FALLING INTO THE UPPER 30S TO LOWER 40S IN MOST AREAS
BY DAYBREAK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
WHILE SFC CDFNT WILL STALL WELL OFFSHORE...THE COLD AIR REMAINS
SHALLOW AND THE H850 BAROCLINIC ZN/THERMAL RIBBON ONLY MOVES JUST
OFFSHORE. ALL THE MODEL SUITE (NAM/GFS/ECMWF/CMC) HAS COME INTO
AGREEMENT NOW SUN...WITH THE GFS JOINING THE OTHERS. STRONG 500HPA
SHORT WV EJECTS E FM OH VLY...ACROSS THE BAROCLINIC ZONE... AND
CLOUDS (DURING THE MORNING) AND WAA/OVERRUNNING RN (AFTN AND
EVENING) SPREAD QUICKLY NE BACK INTO THE REGION SUNDAY.
FORTUNATELY THIS SYSTEM IS FAST MOVING AND CYCLOGENISUS IS
MINIMAL...RAIN EXITS OVERNIGHT WITH MOST AREAS SUBJECT TO 6-12
HOURS OF RAIN SUN AFTN AND EVENING. WITH CLOUDS AND CAA TEMPS
WILL BE QUITE COOLER THAN THEY HAVE HAVE BEEN AND SVRL DEGREES
BLO NORMALS.
THERE WILL ALSO BE BRIEF PERIODS WHERE CONDS SUPPORT LK EFFECT
-SHRA AND SH-SN AT NIGHT OVER HIR TRRN TNGT AND SUN NIGHT...BUT
CHANGES IN FLOW AND WEAK FLOW WILL KEEP THIS CONFINED TO TUG HILL
AND LT.
AT 500HPA BROAD TROF OVER MID CONTINENT WILL RESULT IN SW FLOW
ACROSS FCA..AS SERIES OF SHORT WVS DIVE INTO TROF MOST ROTATING
WELL SOUTH OR NORTH OF REGION TILL WED. COLUMBUS DAY COOL HIGH
PRESSURE BUILDS FM OH VLY INTO NEW ENG. SOME WK LK RESPONSE MAY
LINGER INTO MONDAY MORNING IN N HERK/HAM COUNTIES...BUT WITH
SFC/LLVL FLOW BCMG LT AND SW...THIS WILL END.
SFC HI PRESSURE WILL REMAIN OVER THE RGN MON INTO WED MRNG. GEN
PC/CLEAR CONDS...SOME PATCHY CLOUDS IN MID LVL WAA N TIER..BUT A
FINE FALL PERIOD OF WX...NR NORMAL TEMPS...LT WINDS.
BY WED 500 TROF AXIS HAS SHIFTED E TO GRTLKS...AND SERIES OF SHORT
WVS DRIVES A CDFNT THRU FCA DURING LATE AFTN AND EVNG. THIS IS
ANOTHER ANNA TYPE EVENT LIKE TDY (SAT) WITH PD OF LT RAIN POST
FRONTAL.
MORNING LOWS MONDAY AND TUES UNDER CLEAR SKIES AND SFC HI W/12.5
PLUS HOURS OF NIGHT WILL HAVE NO PROBLEM FALLING INTO MID 20S TO
MID 30S. WOULD SUSPECT THIS TIME TOMORROW WE WILL BE CONSIDERING
FROST AND FREEZE FLAGS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
OTHER THAN MINOR TIMING DIFFERENCES ECMWF AND GFS IN REASONABLE
AGREEMENT. POPULATED WITH GMOS MAKING MINOR CHANGES. MID CONTINENT
500HPA TROF GRADUALLY SLIDES EASTWARD DURING THIS PERIOD AS A
500HPA RIDGE BUILDS IN ITS WAKE INTO THE GRTLKS TO END THE PERIOD.
THE PARADE OF SHORT WAVES CONTINUE TO MIGRATE AROUND THE BASE OF
THE TROF IN THE FAST FLOW. HIGH PRESSURE PASSES FM OH VLY TO MID
ATLC STATES THUR WITH GENERALLY FAIR CONDS. CLOUDS MAY INCR N AHEAD
OF NEXT SYSTEM THU AFTN AS PER GFS...BUT ECMWF KEEPS THIS MOISTURE
N OF RGN.
THE NEXT SHORT WV TO DRIVE A CDFNT THROUGH RGN IS FRI WITH WHAT
APPEARS TO BE YET ANOTHER ANNA TYPE CDFNT WITH PD OF LT RAIN IN ITS
WAKE. WITH TROF AXIS HAVING MOVED E TO OVER NY/NEW ENG FRI
NIGHT...CAA SURGE WILL BE STRONGER THE PVS FEW...WITH MINS IN 20S
TO LOW 30S MOST AREAS...AND WARMER READINGS CONFINED TO FAR SE.
WHERE THE GROWING SEASON IS STILL BARELY HANGING ON...IT SHOULD BE
OVER IN MOST AREAS BY THE WEEKEND. THE WEEKEND STARTS WITH ANOTHER
HIGH PRESSURE AREA IN THE FAST FLOW PASSING ACROSS RGN SAT. HWVR
THE PERIOD ENDS WITH 500HPA TROF EXITING...RIDGING IN ITS WAKE AND
WAA OVERSPREADING THE RGN FM THE WEST IN SPLIT FLOW.
TEMPS WILL REMAIN BLO NORMS FOR MOST OF THIS PERIOD. WHILE DRY AND
FAIR MUCH OF THE TIME A CDFNT WILL BRING A CHC OF -SHRA FRI AND
RAIN MAY OVERSPREAD THE REGION TO END THE WEEK.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH THE
END OF THE TAF PERIOD ENDING AT 06Z MONDAY. THE EXCEPTION WILL BE
AT KPOU WHERE VSBYS WILL BE MVFR/VFR WITH RAIN THIS AFTERNOON. FOR
THE REMAINDER OF TONIGHT SOME MID AND HIGH LEVEL CLOUDINESS WILL
MOVE INTO THE AREA AND THICKEN SUNDAY MORNING WITH BKN-OVC CONDITIONS.
SOME RAIN WILL MOVE INTO THE REGION FROM SOUTH TO NORTH DURING
THE AFTN/EVE HOURS. THE MODELS ARE NOT IN AGREEMENT YET WITH THE
EXACT TIMING AND PLACEMENT OF THIS RAIN...BUT IT/S POSSIBLE THAT
RAIN HOLDS OFF FOR KALB/KGFL UNTIL 00Z MONDAY. KPSF/KPOU HAVE A
BETTER CHC OF SEEING SOME LIGHT RAIN DURING THE AFTN OR EVENING
HOURS. FLYING CONDITIONS COULD DROP TO MVFR WITHIN ANY RAINFALL.
WESTERLY WINDS WILL CONTINUE TO BE RATHER LIGHT.
OUTLOOK...
SUN NT...VFR/MVFR. CHC/LIKELY -SHRA SUN EVENING.
MON-TUE NT...VFR. NO SIG WX.
WED...VFR. CHC MVFR IN SHOWERS.
THU...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE EXPECTED. A WAVE OF LOW
PRESSURE WILL MOVE ALONG THE FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING MOST AREAS OVER A QUARTER INCH OF RAIN SUNDAY. HIGH
PRESSURE WILL BUILD INTO THE REGION ON MONDAY WITH FAIR AND COOL
WEATHER INTO WEDNESDAY WHEN ANOTHER FRONTAL SYSTEM WILL BRING A
PERIOD OF SHOWERS.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 7 DAYS.
AROUND A QUARTER INCH OF RAINFALL IS EXPECTED SUNDAY AFTERNOON/EVENING
AND WEDNESDAY AFTERNOON/EVENING. IN THE TUG HILL PLATEAU LAKE EFFECT
RAIN SHOWERS...AND OVER THE HIGHER TERRAIN AT NIGHT SNOW SHOWERS...WILL
PRODUCE UP TO AN INCH LIQUID TOTAL THIS WEEK. THESE AMOUNTS WILL
BE INSUFFICIENT TO PRODUCE MUCH RESPONSE IN RIVERS AND CREEKS THIS
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...FRUGIS/SNYDER
NEAR TERM...FRUGIS/KL
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...11/FRUIGIS
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS ALBANY NY
105 AM EDT SUN OCT 7 2012
.SYNOPSIS...
MUCH COOLER AIR WILL CONTINUE TO STREAM INTO OUR REGION
OVERNIGHT AS WEAK HIGH PRESSURE CRESTS ACROSS THE REGION. LOW
PRESSURE WILL MOVE ALONG A FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING US MORE UNSETTLED WEATHER FOR SUNDAY AFTERNOON INTO
SUNDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE REGION ON MONDAY AND
BRING FAIR AND SEASONABLE WEATHER FOR THE FIRST HALF OF THE WORK
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM EDT...A BAND OF LAKE EFFECT RAIN SHOWERS HAS
DEVELOPED OFF LAKE ONTARIO. WHILE THE MAJORITY OF THESE RAIN
SHOWERS ARE REMAINING CLOSE TO THE LAKESHORE AND ACROSS THE TUG
HILL...A FEW SHOWERS WILL MAKE IT INTO THE FAR WESTERN
ADIRONDACKS. AS THE FLOW SHIFTS...THIS BAND WILL GRADUALLY SHIFT
SOUTH...POSSIBLY AFFECTING PARTS OF THE WESTERN MOHAWK VALLEY BY
LATE TONIGHT. THIS IS BEING MODELED WELL BY THE LATEST HRRR AND
LOCAL WRF.
MEANWHILE...A SFC FRONTAL BOUNDARY CONTINUES TO MOVE TO THE SOUTH
AND EAST OF OUR AREA ACROSS EASTERN NEW ENGLAND AND DOWN OFF THE
MID ATLANTIC SEABOARD. MID AND HIGH LEVEL CLOUDS ARE ALREADY
BEGINNING TO STREAK INTO THE REGION FROM THE SOUTHWEST...AND WILL
CONTINUE TO INCREASE TOWARD DAYBREAK AS A WAVE OF LOW PRESSURE
DEVELOPS ALONG THE FRONTAL BOUNDARY TO OUR SOUTH.
MIN TEMPS OVERNIGHT WILL BE MUCH COOLER THAN RECENT NIGHTS.
HOWEVER...DUE TO SOME WIND PERSISTING...AND THE PROSPECTS FOR
INCREASING CLOUDS...HAVE RAISED FORECAST MINS A BIT...WITH
LOWS GENERALLY FALLING INTO THE UPPER 30S TO LOWER 40S IN MOST AREAS
BY DAYBREAK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
WHILE SFC CDFNT WILL STALL WELL OFFSHORE...THE COLD AIR REMAINS
SHALLOW AND THE H850 BAROCLINIC ZN/THERMAL RIBBON ONLY MOVES JUST
OFFSHORE. ALL THE MODEL SUITE (NAM/GFS/ECMWF/CMC) HAS COME INTO
AGREEMENT NOW SUN...WITH THE GFS JOINING THE OTHERS. STRONG 500HPA
SHORT WV EJECTS E FM OH VLY...ACROSS THE BAROCLINIC ZONE... AND
CLOUDS (DURING THE MORNING) AND WAA/OVERRUNNING RN (AFTN AND
EVENING) SPREAD QUICKLY NE BACK INTO THE REGION SUNDAY.
FORTUNATELY THIS SYSTEM IS FAST MOVING AND CYCLOGENISUS IS
MINIMAL...RAIN EXITS OVERNIGHT WITH MOST AREAS SUBJECT TO 6-12
HOURS OF RAIN SUN AFTN AND EVENING. WITH CLOUDS AND CAA TEMPS
WILL BE QUITE COOLER THAN THEY HAVE HAVE BEEN AND SVRL DEGREES
BLO NORMALS.
THERE WILL ALSO BE BRIEF PERIODS WHERE CONDS SUPPORT LK EFFECT
-SHRA AND SH-SN AT NIGHT OVER HIR TRRN TNGT AND SUN NIGHT...BUT
CHANGES IN FLOW AND WEAK FLOW WILL KEEP THIS CONFINED TO TUG HILL
AND LT.
AT 500HPA BROAD TROF OVER MID CONTINENT WILL RESULT IN SW FLOW
ACROSS FCA..AS SERIES OF SHORT WVS DIVE INTO TROF MOST ROTATING
WELL SOUTH OR NORTH OF REGION TILL WED. COLUMBUS DAY COOL HIGH
PRESSURE BUILDS FM OH VLY INTO NEW ENG. SOME WK LK RESPONSE MAY
LINGER INTO MONDAY MORNING IN N HERK/HAM COUNTIES...BUT WITH
SFC/LLVL FLOW BCMG LT AND SW...THIS WILL END.
SFC HI PRESSURE WILL REMAIN OVER THE RGN MON INTO WED MRNG. GEN
PC/CLEAR CONDS...SOME PATCHY CLOUDS IN MID LVL WAA N TIER..BUT A
FINE FALL PERIOD OF WX...NR NORMAL TEMPS...LT WINDS.
BY WED 500 TROF AXIS HAS SHIFTED E TO GRTLKS...AND SERIES OF SHORT
WVS DRIVES A CDFNT THRU FCA DURING LATE AFTN AND EVNG. THIS IS
ANOTHER ANNA TYPE EVENT LIKE TDY (SAT) WITH PD OF LT RAIN POST
FRONTAL.
MORNING LOWS MONDAY AND TUES UNDER CLEAR SKIES AND SFC HI W/12.5
PLUS HOURS OF NIGHT WILL HAVE NO PROBLEM FALLING INTO MID 20S TO
MID 30S. WOULD SUSPECT THIS TIME TOMORROW WE WILL BE CONSIDERING
FROST AND FREEZE FLAGS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
OTHER THAN MINOR TIMING DIFFERENCES ECMWF AND GFS IN REASONABLE
AGREEMENT. POPULATED WITH GMOS MAKING MINOR CHANGES. MID CONTINENT
500HPA TROF GRADUALLY SLIDES EASTWARD DURING THIS PERIOD AS A
500HPA RIDGE BUILDS IN ITS WAKE INTO THE GRTLKS TO END THE PERIOD.
THE PARADE OF SHORT WAVES CONTINUE TO MIGRATE AROUND THE BASE OF
THE TROF IN THE FAST FLOW. HIGH PRESSURE PASSES FM OH VLY TO MID
ATLC STATES THUR WITH GENERALLY FAIR CONDS. CLOUDS MAY INCR N AHEAD
OF NEXT SYSTEM THU AFTN AS PER GFS...BUT ECMWF KEEPS THIS MOISTURE
N OF RGN.
THE NEXT SHORT WV TO DRIVE A CDFNT THROUGH RGN IS FRI WITH WHAT
APPEARS TO BE YET ANOTHER ANNA TYPE CDFNT WITH PD OF LT RAIN IN ITS
WAKE. WITH TROF AXIS HAVING MOVED E TO OVER NY/NEW ENG FRI
NIGHT...CAA SURGE WILL BE STRONGER THE PVS FEW...WITH MINS IN 20S
TO LOW 30S MOST AREAS...AND WARMER READINGS CONFINED TO FAR SE.
WHERE THE GROWING SEASON IS STILL BARELY HANGING ON...IT SHOULD BE
OVER IN MOST AREAS BY THE WEEKEND. THE WEEKEND STARTS WITH ANOTHER
HIGH PRESSURE AREA IN THE FAST FLOW PASSING ACROSS RGN SAT. HWVR
THE PERIOD ENDS WITH 500HPA TROF EXITING...RIDGING IN ITS WAKE AND
WAA OVERSPREADING THE RGN FM THE WEST IN SPLIT FLOW.
TEMPS WILL REMAIN BLO NORMS FOR MOST OF THIS PERIOD. WHILE DRY AND
FAIR MUCH OF THE TIME A CDFNT WILL BRING A CHC OF -SHRA FRI AND
RAIN MAY OVERSPREAD THE REGION TO END THE WEEK.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
VFR FLYING CONDITIONS ARE EXPECTED THROUGH MUCH OF THE OVERNIGHT
HOURS WITH JUST FEW-SCT STRATOCU CLOUDS AROUND 4-6 KFT...MAINLY
DURING THE EVENING HOURS. SOME MID AND HIGH LEVEL CLOUDINESS WILL
MOVE INTO THE AREA TOWARDS DAYBREAK. LIGHT WESTERLY WINDS WILL BE IN
PLACE TONIGHT...AND WITH DEWPOINTS DROPPING DOWN INTO THE 30S...NO
RADIATIONAL FOG IS EXPECTED TO DEVELOP TONIGHT.
BKN-OVC MID LEVEL CLOUDINESS WILL BE IN PLACE FOR SUNDAY MORNING. SOME
RAIN WILL MOVE INTO THE REGION FROM SOUTH TO NORTH DURING THE
AFTN/EVE HOURS. THE MODELS ARE NOT IN AGREEMENT YET WITH THE EXACT
TIMING AND PLACEMENT OF THIS RAIN...BUT IT/S POSSIBLE THAT RAIN HOLDS
OFF FOR KALB/KGFL UNTIL 00Z MONDAY. KPSF/KPOU HAVE A BETTER CHC OF
SEEING SOME LIGHT RAIN DURING THE AFTN OR EVENING HOURS. FLYING
CONDITIONS COULD DROP TO MVFR WITHIN ANY RAINFALL. WESTERLY WINDS
WILL CONTINUE TO BE RATHER LIGHT.
OUTLOOK...
SUN NT...VFR/MVFR. CHC/LIKELY -SHRA SUN EVENING.
MON-TUE NT...VFR. NO SIG WX.
WED...VFR. CHC MVFR IN SHOWERS.
THU...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE EXPECTED. A WAVE OF LOW
PRESSURE WILL MOVE ALONG THE FRONTAL BOUNDARY STALLED JUST TO OUR
SOUTH GIVING MOST AREAS OVER A QUARTER INCH OF RAIN SUNDAY. HIGH
PRESSURE WILL BUILD INTO THE REGION ON MONDAY WITH FAIR AND COOL
WEATHER INTO WEDNESDAY WHEN ANOTHER FRONTAL SYSTEM WILL BRING A
PERIOD OF SHOWERS.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 7 DAYS.
AROUND A QUARTER INCH OF RAINFALL IS EXPECTED SUNDAY AFTERNOON/EVENING
AND WEDNESDAY AFTERNOON/EVENING. IN THE TUG HILL PLATEAU LAKE EFFECT
RAIN SHOWERS...AND OVER THE HIGHER TERRAIN AT NIGHT SNOW SHOWERS...WILL
PRODUCE UP TO AN INCH LIQUID TOTAL THIS WEEK. THESE AMOUNTS WILL
BE INSUFFICIENT TO PRODUCE MUCH RESPONSE IN RIVERS AND CREEKS THIS
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...FRUGIS/SNYDER
NEAR TERM...KL/FRUGIS
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...FRUGIS
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
243 AM MDT SUN OCT 7 2012
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 243 AM MDT SUN OCT 7 2012
FORECAST CONCERNS WILL BE HOW MUCH THE TEMPERATURES MODERATE THROUGH
MONDAY BEFORE THE NEXT COLD FRONT MOVES IN TO COOL OFF TUESDAY.
SATELLITE CONTINUING TO SHOW AN AMPLIFIED PATTERN FROM THE PACIFIC
INTO EASTERN NORTH AMERICA. FLOW DOMINATED BY A BLOCK ALONG THE WEST
COAST AND A TROUGH OVER THE CENTRAL AND EASTERN PORTION OF THE
COUNTRY. COLD AND MOIST AIR MASS REMAINS OVER THE CENTRAL PORTION OF
THE COUNTRY.
MODELS INITIALIZED FINE AT THE JET AND MID LEVELS. NAM WAS CATCHING
THE SURFACE RIDGING AND WIND FIELD IN OUR AREA THE BEST. NAM AND
RUC APPEAR TO BE CATCHING THE STRATUS FIELD THE BEST. THE GFS AND
CANADIAN WERE DOING A LITTLE BETTER THAN THE REST ON THE LOW LEVEL
THERMAL FIELD.
TODAY/TONIGHT...STRATUS KEEPS EDGING EVER SO SLOWLY SOUTHWEST. NOT
SURE HOW MUCH FURTHER IT WILL GO. LOCATIONS ON THE EDGE OF THIS
CLOUD FIELD ARE NOT THAT FAR AWAY FROM REACHING THE NEEDED
TEMPERATURES FOR THE FREEZE WARNING TO VERIFY. AT THIS TIME I WILL
LET THE FREEZE WARNING CONTINUE BUT FEELING IS THAT THE FAR
SOUTHWEST AND WESTERN PORTIONS WILL NOT MAKE IT.
SOME FOG HAS DEVELOPED. THE 00Z NAM DRASTICALLY OVERDID THE FOG. THE
06Z NAM IS NOW MORE REALISTIC AND DEVELOPING FOG IN AREAS THAT HAVE
CLEARED. THE HRRR AND RUC DO NOT AGREE WITH EACH OTHER BUT TEND TO
FAVOR THE WEST AND MORE IN LOCATIONS THAT HAVE THE STRATUS. AT THIS
TIME WILL ADD FOG PER THE LATEST NAM WHICH DOES MAKE SENSE.
WEAK LEFT FRONT QUADRANT OF THE UPPER JET AND A RATHER STRONG
SHORTWAVE MOVES THROUGH DURING THE LATE MORNING AND AFTERNOON. WILL
HAVE TO KEEP WATCHING BUT THESE FEATURES LOOK TO SPREAD SOME HIGHER
LEVEL CLOUD COVER ACROSS THE AREA. TEMPERATURES TODAY WILL BE
AFFECTED BY HOW FAST THE STRATUS LEAVES WHICH LOOKS TO BE BY LATE
MORNING. HAVE AN AREA IN THE NORTHERN PORTION OF THE AREA THAT HAD
SIX PLUS INCHES OF SNOW YESTERDAY. AREAS DOWNSTREAM OF SNOW FIELD
COULD BE AFFECT. WITH WARM GROUND WOULD IMAGINE THAT SNOW WOULD MELT
A LITTLE FASTER THAN NORMAL. WILL DEFINITELY HAVE AN AFFECT TODAY ON
THE TEMPERATURES AND MADE THAT AREA COOLER THAN SURROUNDING
LOCATIONS. IF STRATUS HOLDS ON LONGER ALL THE TEMPERATURES MAY END
UP BEING TOO WARM.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF UPPER JET MOVES ACROSS
AT THE BEGINNING OF THE DAY. IT LOOKS LIKE IT WILL SPREAD SOME CLOUDS
ACROSS THE AREA. MODELS SHOW GOOD DOWNSLOPE WINDS THROUGH MOST OF
THE DAY UNTIL THEY BECOME LIGHTER AND MORE IN THE MIDDLE OF THE
AFTERNOON. SO WILL TREND TOWARD THE WARMER GUIDANCE.
THERE IS SOME MODEL DIFFERENCES IN HOW TO HANDLE THE SYSTEM DIGGING
OUT OF CENTRAL CANADA. THE NAM IS FASTER AND DEEPER. GFS IS NOT AS
DEEP. OTHER MODELS ARE FAIRLY DEEP...SLOWER AND ARE A LITTLE
FURTHER SOUTHWEST. AS A CONSEQUENCE THE NAM IS THE FASTEST TO PUSH
THE FRONT THROUGH AND THROUGH MOST OF THE AREA BY 12Z. IT IS ALWAYS
POSSIBLE IN THIS SCENARIO THAT FRONTS WILL COME IN FASTER BUT AM
LEARY OF THE NAM A LITTLE. SO WENT IN THE MIDDLE OF THE SOLUTIONS.
TUESDAY/TUESDAY NIGHT...ABOVE MENTIONED JET MOVES ACROSS DURING THE
MORNING BUT MODELS INDICATE VERY LITTLE CLOUD COVER WILL BE GENERATED
BY THIS FEATURE. ALL THE MODELS HAVE THE FRONT THROUGH THE FORECAST
AREA BY 18Z. THERE IS A LITTLE BIT OF SPREAD IN HOW MUCH COOLING
TAKES PLACE. THE NAM IS THE WARMEST BUT NOT BY MUCH AND THE ECMWF
THE COOLEST. THE OTHER MODELS CLUSTER IN THE MIDDLE. AT THIS TIME
WILL GO WITH A COMPROMISE OF TEMPERATURES WHICH DOES LOWER THE
MAXES A LITTLE.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 243 AM MDT SUN OCT 7 2012
THE UPPER PATTERN DURING THIS PERIOD WILL TRANSITION FROM FAST
NORTHWEST FLOW ALOFT ON WED TO UPPER RIDGING THU-EARLY FRI TO STRONG
SOUTHWEST FLOW LATER FRI-SAT AS THE UPPER LOW APPROACHING CALIFORNIA
EJECTS NORTHEAST ACROSS THE CENTRAL HIGH PLAINS. NUMERICAL GUIDANCE
HAS VASTLY DIFFERING SOLUTIONS ON WHERE AND HOW FAST THE UPPER LOW
LIFTS OUT OF THE SOUTHWEST U.S. WHICH IS ULTIMATELY TIED TO THE
LOCATION AND INTENSITY OF THE NEXT UPSTREAM TROUGH. THE EC IS NOW
CONSIDERABLY FASTER AND MUCH FURTHER NORTH COMPARED TO GFS. SATURDAY
MORNING THE EC HAS THE UPPER LOW OVER CENTRAL NEBRASKA WHILE GFS
HOLDS IT BACK OVER THE FOUR CORNERS. THE GEM WAS PRETTY MUCH IN STEP
WITH THE GFS THRU 144 HRS /FRI/. NEEDLESS TO SAY...CONFIDENCE IS
LOW IN THE TIMING AND AMOUNT OF ASSOCIATED PRECIP IN THE FRI-SAT
TIME FRAME. EXPERIENCE WOULD FAVOR A SLOWER /GFS/ MOVEMENT BUT A
BLEND IS PROBABLY APPROPRIATE AT THIS POINT. WHICHEVER MODEL
VERIFIES... IF EITHER ONE DOES... WILL ALSO MAKE A BIG DIFFERENCE IN
THE POTENTIAL TO GET DRY SLOTTED. WHATEVER THE OUTCOME...LOOKS LIKE
A RETURN TO MORE TYPICAL OCTOBER TEMPERATURES GIVEN THE UPPER
PATTERN CHANGE DURING PERIOD.
AT THE SURFACE...ONE LAST CANADIAN HIGH PRESSURE AREA WILL DROP
SOUTHEAST INTO THE AREA THURSDAY BEFORE UPPER RIDGING AND SOUTHWEST
FLOW ALOFT TAKE OVER. THE EC IS A LITTLE SLOWER WITH THE COLD
FRONTAL PASSAGE COMPARED TO GFS/GEM WHICH COULD MAKE THURSDAY MAX
TEMPS A LITTLE TRICKY. CURRENT FORECAST HAS MAX TEMPERATURES IN THE
UPPER 60S/LOWER 70S BEFORE FRONTAL PASSAGE.
THE NEXT SHOT AT PRECIP LOOKS TO BE TOWARD THE END OF THIS FORECAST
PERIOD WITH TIMING DEPENDING ON SPEED AT WHICH UPPER LOW EJECTS
NORTHEAST. THE EC BRINGS IN POTENTIAL FOR SHOWERS AND THUNDERSTORMS
EARLY FRIDAY MORNING WHILE GFS TIMING IS FRIDAY NIGHT INTO SATURDAY.
CURRENT FORECAST IS A BLEND OF NUMERICAL GUIDANCE AND BRINGS IN
CHANCE POPS STARTING FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1115 PM MDT SAT OCT 6 2012
FOR KGLD MVFR CIGS EXPECTED THROUGH 18Z OR SO AS AXIS OF LOW LEVEL
MOISTURE REMAINS OVER THE TERMINAL. AFTER 18Z VFR CONDITIONS
EXPECTED. AT KMCK SMALL AREA OF STRATUS AND IFR CIGS CURRENTLY
OVER THE TERMINAL. THIS SHOULD CONTINUE FOR A FEW HOURS BEFORE
MOVING OUT OF THE AREA LEAVING VFR CONDITIONS THROUGH THE
REMAINDER OF THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FREEZE WARNING UNTIL 9 AM MDT /10 AM CDT/ SUNDAY FOR KSZ001>004-
013>016-027>029-041-042.
CO...FREEZE WARNING UNTIL 9 AM MDT SUNDAY FOR COZ090>092.
NE...FREEZE WARNING UNTIL 9 AM MDT /10 AM CDT/ SUNDAY FOR NEZ079>081.
&&
$$
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...DDT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1219 AM CDT SUN OCT 7 2012
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1256 PM CDT SAT OCT 6 2012
A DEEP LONGWAVE TROUGH ENCOMPASSED MUCH OF THE NORTHERN CONUS WITH
250MB CYCLONICALLY CURVED FLOW FROM THE GREAT BASIN THROUGH THE
GREAT PLAINS TO THE GREAT LAKES REGION. WITHIN THE LONGWAVE
TROUGH...A SHORTWAVE TROUGH WAS MOVING SOUTHEAST THROUGH WESTERN
NEBRASKA EARLY SATURDAY. 12Z UPPER AIR ANALYSIS REVEALED 700MB
FRONTOGENETIC ZONE EXTENDING FROM SOUTHERN WYOMING THROUGH EASTERN
COLORADO TO SOUTHWESTERN KANSAS WITH SATURATED OR NEAR SATURATED AIR
(700MB DEWPOINT DEPRESSIONS 0 OR 1 DEGC AT KRIW, KDNR, KDDC, KAMA,
KOUN). PRECIPITATION IN THE FORM OF RAIN AND SNOW EXTENDED ALL
ALONG THE STRONGEST ZONE OF MID LEVEL FRONTOGENESIS (THE STRONGEST
OF WHICH FROM NORTHEAST COLORADO TO NORTHWEST KANSAS TO FAR
SOUTHWEST NEBRASKA AS OF 17Z). LIGHTER BANDED PRECIPITATION WAS
FOUND ACROSS SOUTHWEST KANSAS WHERE 0.06 INCHES OF PRECIPITATION WAS
MEASURED SO FAR AT DODGE CITY (ALL IN THE FORM OF RAIN). SNOW WAS
REPORTED AS FAR SOUTHEAST AS DIGHTON...AND VERY BRIEFLY MIXED IN
WITH RAIN ACROSS THE NORTHWEST PORTIONS OF FORD COUNTY DURING ONE OF
THE HEAVIER BANDS EARLIER THIS MORNING. IT SEEMS THE SNOW LINE IS
MATCHING UP WELL WITH THE RAP ANALYZED 900 FT AGL FREEZING
LEVEL...WHICH EXTENDED FROM ROUGHLY GARDEN CITY TO DIGHTON (AND
POINTS NORTHWEST) AT 18Z.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 316 PM CDT SAT OCT 6 2012
THIS EVENING:
MID LEVEL FRONTOGENESIS (MAINLY CENTERED AROUND 700MB) WILL CONTINUE
TO DECREASE ACROSS WEST CENTRAL AND CENTRAL KANSAS AS THE MID LEVEL
SHORTWAVE TROUGH ACROSS SOUTHWEST NEBRASKA MOVES TOWARD SOUTHEAST
NEBRASKA. MID LEVEL DRYING FROM 800 TO 500MB (AND ABOVE THROUGH THE
UPPER TROPOSPHERE) WILL INCREASE AS SUBSIDENCE PREVAILS IN THE WAKE
OF THE PRIMARY SHORTWAVE TROUGH. MOISTURE AND ATTENDANT CLOUD IN THE
LOWER TROPOSPHERE (800-900MB) WILL ALSO BE DECREASING...HOWEVER RATE
OF DECREASE ACROSS SOUTHWEST AND WEST CENTRAL KANSAS IS STILL A
FAIRLY CHALLENGING FORECAST AS LOW STRATUS WILL BE DIFFICULT TO
DISLODGE AS REMNANT LOW LEVEL MOISTURE RECIRCULATES AROUND THE
ANTICYCLONE IN THIS LAYER. FEEL THAT CLOUDS IN THE 800-900MB LAYER
WILL SCATTER OUT SLOWLY FROM 00-06Z TONIGHT...AND MOST PROMINENT
FARTHER NORTHEAST AWAY FROM COLORADO.
OVERNIGHT:
A 1030MB SURFACE HIGH WILL BE MOVING SOUTH-SOUTHEAST WITH CENTER OF
SURFACE HIGH TAKING A TRACK FROM ROUGHLY WRAY, COLORADO TO DODGE
CITY TONIGHT. ALONG THE TRACK OF THE SURFACE HIGH SKY SHOULD CLEAR
OUT AFTER MIDNIGHT...AND TEMPERATURES WILL FALL INTO THE LOWER 30S
RATHER QUICKLY ONCE CLOUDS CLEAR. TEMPERATURES WILL MOST LIKELY
FALL TO 28 TO 30 DEGREES NORTH OF THE ARKANSAS RIVER BY 08 OR 09Z
AND REMAIN IN THIS RANGE FOR PROBABLY 4 OR 5 HOURS...WITH MINIMUM
AROUND SUNRISE OF 25 TO 27 DEGREES NORTH OF A DIGHTON TO NESS CITY
TO LACROSSE LINE. THIS IS MORE OR LESS A CONTINUATION OF THE
PREVIOUS FORECAST AND AM NOT MAKING ANY CHANGES TO THE GOING FREEZE
HEADLINES. WILL CONTINUE THE HARD FREEZE WARNING (28 DEGREES OR
BELOW FOR LOWS) NORTH OF A JOHNSON TO BUCKLIN TO STAFFORD LINE.
SOUTH OF THIS LINE TO THE OKLAHOMA BORDER WILL CONTINUE WITH THE
FREEZE WARNING FOR LOWS 29 TO 32 DEGREES. MUCH, IF NOT ALL, OF WEST
CENTRAL, SOUTHWEST, AND SOUTH CENTRAL KANSAS WILL SEE THE END TO THE
GROWING SEASON WITH THESE FORECAST TEMPERATURES TONIGHT.
SUNDAY:
A SECONDARY MINOR SHORTWAVE DISTURBANCE WILL BE ROTATING AROUND THE
MEAN TROUGH AXIS FROM SOUTHERN WYOMING TO NORTHEASTERN NEW
MEXICO...WHICH MAY BRING SOME MID LEVEL CLOUD BACK TO FAR SOUTHWEST
KANSAS BY DAYBREAK...HOWEVER NO OTHER SENSIBLE WEATHER IMPACTS ARE
EXPECTED WITH THIS FINAL SHORTWAVE TROUGH PASSAGE. THE SURFACE HIGH
WILL SHIFT INTO THE RED RIVER VALLEY BY MIDDAY SUNDAY...BUT OVERALL
PRESSURE GRADIENT WILL REMAIN RATHER WEAK WITH SOUTHWEST WINDS 8 TO
10 KNOTS EXPECTED. A WARMING OF THE LOWER TROPOSPHERE FROM DOWNSLOPE
MOMENTUM (850MB TEMPS INCREASING TO +5 TO +9C FROM EAST TO WEST)
WILL ALLOW SURFACE TEMPERATURES TO WARM UP WELL INTO THE MID TO
UPPER 50S...ESPECIALLY ACROSS CENTRAL AND SOUTH CENTRAL KANSAS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CDT SAT OCT 6 2012
MONDAY:
BROAD 500-250 HPA WNW FLOW IS EXPECTED MONDAY. THIS ORTHOGONAL FLOW
WRT THE ROCKIES WILL ALLOW FOR A LEE TROUGH TO FORM MONDAY FROM THE
SURFACE UP TO 850 HPA. AS A RESULT, A WEAK WARM AIR ADVECTION REGIME
IS EXPECTED WITH HIGHS MODERATING TO THE UPPER 60S DEG F TO AROUND
70 DEG F. A DRY FORECAST IS EXPECTED FOR THE BEGINNING OF THE WORK WEEK
AS THE REGION WILL BE FREE OF ANY SYNOPTIC DISTURBANCES AND ASSOCIATED
LIFT.
TUESDAY:
THE SYNOPTIC PATTERN CHANGES TUESDAY AS A BROAD POSITIVELY TILTED UPPER
LEVEL SHORTWAVE TROF EJECTS FROM THE CANADIAN PRAIRIES AND ACROSS THE
NORTHERN PLAINS. THIS UL FEATURE WILL USHER IN A PASSAGE OF A COLD FRONT.
HAVE USED 12Z ECMWF AS GUIDANCE FOR TEMPERATURES AS THE GFS CONTINUES
TO PERFORM POORLY (IN THIS CASE, USUALLY TOO AGGRESSIVE WITH THE FROPA).
HIGHS WILL VARY ACROSS THE REGION WITH LOW TO MID 60S DEG F ACROSS THE
INTERSTATE 70 CORRIDOR TO MID 70S DEG F ACROSS EXTREME SOUTHWEST KANSAS.
THIS FRONT WILL BE DRY WITH A LACK OF BOUNDARY LAYER MOISTURE IN PLACE.
WILL KEEP POPS NEAR ZERO PERCENT. SFC WINDS DON`T LOOK PARTICULARLY
STRONG WITH THIS HIGH AS 850 HPA WINDS ARE ONLY FORECAST TO BE IN THE
20-25 KT RANGE.
WEDNESDAY:
A RIDGE OF HIGH PRESSURE WILL TRANSLATE ACROSS THE SUNFLOWER STATE WEDNESDAY
IN THE WAKE OF THE DENSITY GRADIENT. HIGHS IN THE 60S DEG F ARE EXPECTED
AS FAIRLY COOL 850 HPA TEMPERATURES (9-13 DEG C) ARE FORECAST IN ASSOCIATION
WITH THE AFOREMENTIONED COOL HIGH PRESSURE CENTER MOVING ACROSS THE
STATE. WILL ALSO RUN WITH THE ALLBLEND POPS (AROUND 3 PERCENT) FOR
THE MIDDLE PORTION OF THE WORK WEEK.
THURSDAY AND BEYOND:
THE FORECAST BECOMES MORE INTERESTING TOWARDS THE END OF THE WORK WEEK
ALTHOUGH SYNOPTIC AND MESOSCALE DETAILS ARE VERY UNCERTAIN AT THIS POINT.
FOR EXAMPLE, YESTERDAYS ECMWF RUN HAD THE WARM SECTOR (HIGHER THETA-E
AIR) SPREADING NORTHWARD IN ASSOCIATION WITH THE PASSAGE OF A WARM FRONT
FRIDAY. TODAY`S 12Z ECMWF RUN KEEPS THAT BOUNDARY SOUTH OF THE REGION
FRIDAY. THIS BOUNDARY PLACEMENT WILL HAVE SIGNIFICANT IMPACTS IN TERMS
OF SENSIBLE WEATHER AS A WAA PATTERN/THETA-E ADVECTION ALONG SAID FRONT
COULD LEAD TO THE DEVELOPMENT OF CONVECTION ACROSS THE PLAINS. FOR NOW
WILL GO WITH A BLEND OF THE ALLBLEND POPS ALTHOUGH WILL SMOOTH POPS
TOWARDS A BIAS TO THE ECMWF. THE GFS WAS GENERALLY DISREGARDED AS THE
MODEL CONTINUES TO BE VERY PROGRESSIVE WITH UL FEATURES THAT WILL PROBABLY
SLOW DOWN WITH TIME. IT SHOULD BE NOTED THAT MUCH UNCERTAINTY EXISTS
WITH THE EVOLUTION OF THE DESERT SOUTHWEST UL LOW THAT WILL BE THE IMPETUS
FOR CONVECTION. IT ALSO SHOULD BE NOTED THAT THERE IS THE POSSIBILITY
OF SEVERE CONVECTION, PARTICULARLY FRIDAY AND SATURDAY. WARM SECTOR
PLACEMENT AND ASSOCIATED REDISTRIBUTION OF ENERGY PER UNIT MASS (I.E.
CAPE) IS UNCERTAIN. REGARDLESS OF WHEREVER THE WARM SECTOR WILL BE,
THE ECMWF SHOWS SIGNIFICANT BOUNDARY LAYER MOISTURE WORKING ITS WAY
NORTH FROM THE GULF OF MEXICO. KINEMATIC PROFILES ALSO STRENGTHEN WITH
TIME AS THE UL LOW MOVES CLOSER TO KANSAS WITH 250 HPA FLOW INCREASING
TO 100 KT, 500 HPA FLOW INCREASING TO 60 KT, AND FAIRLY STRONG AND VEERING
FLOW FROM THE SFC THROUGH 700 HPA. SEVERE WEATHER EPISODES IN OCTOBER
ARE NOT UNUSUAL FOR THE PLAINS. IN FACT, THERE WERE TORNADOES LAST OCTOBER
ACROSS THE REGION LAST YEAR. IT IS TOO EARLY TO DETERMINE STORM MODE
AND PLACEMENT AT THIS TIME BUT IT IS SOMETHING TO WATCH FOR IN FUTURE
MODEL RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1219 AM CDT SUN OCT 7 2012
MVFR CIGS AT GARDEN CITY WILL GRADUALLY INCREASE TO VFR AROUND
09Z-10Z AS DRIER AIR MOVES INTO SOUTHWEST KANSAS. VFR CIGS AT
DODGE CITY WILL CONTINUE THROUGH MOST OF THE NIGHTTIME HOURS
BEFORE SCATTERING OUT. LOOK FOR MOSTLY CLEAR SKIES TO CONTINUE AT
HAYS. LIGHT AND VARIABLE WINDS WILL BECOME SOUTHWESTERLY AT 10 TO
12 KNOTS BY MIDDAY SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 34 69 43 69 / 0 0 0 0
GCK 32 69 42 67 / 0 0 0 0
EHA 35 67 44 77 / 0 0 0 0
LBL 34 67 42 73 / 0 0 0 0
HYS 34 70 44 66 / 0 0 0 0
P28 35 69 46 71 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR
KSZ030-031-043>046-061>066-074>079.
FREEZE WARNING UNTIL 9 AM CDT THIS MORNING FOR KSZ080-081-
084>090.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...SUGDEN
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1247 AM EDT SUN OCT 07 2012
...Updated Aviation Discussion...
.Forecast Update...
Updated at 1027 PM EDT Sat Oct 6 2012
HRRR and RAP show KY staying dry tonight and this is supported by
regional radars and upstream obs. Decent band of reflectivities
passed over Logan and Simpson Counties within the last hour but
neither Mesonet station reported measurable rainfall. So, will back
off on PoPs a bit. Will still keep some low chances going far south
though in case any activity can blossom ahead of the approaching
upper trof or slip over the border from Tennessee.
&&
.Short Term (Today through Sunday)...
Issued at 300 PM EDT Sat Oct 6 2012
A persistent Rex Block at 500mb just off the Pacific Coast has
allowed
northerly flow to develop downstream across the Upper Midwest. A
chilly Canadian airmass has already penetrated practically as far
south as the Texas Gulf coast, and remains banked up against higher
terrain in New Mexico and Colorado.
Clouds will increase this evening as one of several flat
disturbances embedded within a broader 500mb cyclonic gyre scoots
across Missouri. Both the GFS and NAM models take this feature
across Tennessee and southern Kentucky during the overnight hours. A
light chilly rain may develop across our southern counties later
this evening, ending around dawn across our southern Bluegrass or
Lake Cumberland Region. Precipitation totals will stay light,
totaling around two tenths of an inch or less. Feel that Louisville
and possible Lexington will stay north of this potential strip of
precipitation. Expect a cloudy cool night with lows ranging from
just under 40 to the lower 40s.
Skies will clear pretty readily Sunday morning as this 500mb wave
passes and subsidence overspreads the area. Canadian high pressure
will settle over the southern plains by Sunday afternoon, with an
axis extending east across the Commonwealth. Light north winds
Sunday afternoon will become calm overnight through Monday.
Early Monday will provide our best chance for widespread frost and
even a chance of a light freeze across some of our colder rural
locations. Frost chances will depend on how clear we become by early
Monday. High clouds associated with a disturbance over Tennessee may
spread as far north as Interstate 64 early Monday. This may, if
thick enough, limit frost chances across our south. Agricultural
interests should however, plan on at least some frost across
southern Indiana and north central Kentucky. Some lows early Monday
may reach or approach 32 for a few hours.
.Long Term (Monday - Saturday)...
Issued at 300 PM EDT Sat Oct 6 2012
High pressure will be over the region Monday morning at the same
time a vortmax is crossing the region aloft. Clouds associated with
this shortwave will be over or just east of the eastern forecast
area at the start of this period. During the day Monday and
continuing into Tuesday, the high will become centered over New
England.
Tuesday night, a cold front will move into the Midwest. Moisture
ahead of this front is not that impressive but will be enough to
warrant a chance for rain to come through the forecast area. After
that front, another cold shot of Canadian air will build into the
region, with high pressure becoming centered over the region
Thursday morning. Deterministic and Ensemble models support this
scenario, meaning another chilly morning with more frost possible
Thursday morning.
Progressive flow aloft, with persistent troughiness across eastern
Canada, will bring another moisture-starved front through the region
Friday morning. The high behind this front looks to move more to our
north. This may allow for a quicker return of moisture into the area
for next weekend. 00Z ECMWF and latest GFS/DGEX all indicate some
weak warm frontal-type forcing across the region Saturday, with the
latter two bringing rain into the region. For now will lean toward
the ECMWF solution, which keeps the best rain chances to our
northwest.
&&
.Aviation (06Z TAF Issuance)...
Issued at 1247 PM EDT Sun Oct 7 2012
A few light returns on radar are courtesy of a shortwave over the
Midwest. However, very few observations have recorded rain other
than a sprinkle or two. Have therefore decided to remove mentionable
rain from the BWG TAF. As the shortwave moves east today the mid
level clouds will move out with mainly cirrus expected through the
rest of the TAF period. Winds will be out of the northwest and
become light and variable to calm tomorrow night as surface high
pressure settles directly over the region.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......JSD
Long Term........RJS
Aviation.........EER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
506 AM EDT SUN OCT 7 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SUN OCT 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FULL LATITUDE UPR
TROF OVER ERN NAMERICA...WITH NW FLOW ALF OVER THE UPR GRT LKS. WITH
H85 TEMPS ARND -7C OVER LK SUP /VS WATER TEMPS RANGING FM 6-7C OVER
THE W TO 11-12C OVER THE E/...A WEAK SHRTWV MOVING THRU THE UPR
LKS...AND ADEQUATE LLVL MSTR PER THE 00Z APX RAOB...SOME LK EFFECT
-SHRA MIXED WITH SN CONTINUE OVER MAINLY THE E HALF OF THE LK WHERE
INSTABILITY REMAINS GREATEST. PERSISTENT CNVGC SHOWN BY WIND OBS
OVER THE E HALF OF THE LAKE ARE ALSO HELPING TO MAINTAIN THE
COVERAGE/INTENSITY OF THIS PCPN IN THAT AREA. OVER THE W...MORE ACYC
LLVL FLOW ASSOCIATED WITH SFC RDG EXTENDING FM HI CENTER IN THE
SCNTRL PLAINS TOWARD THE UPR MIDWEST...COOLER WATERS...AS WELL AS
SOMEWHAT DRIER LLVL AIR SHOWN ON THE 00Z INL RAOB ARE CONSPIRING TO
LIMIT THE ACTIVITY OVER THAT PART OF THE LAKE. ALTHOUGH DRIER AIR
OVER THE NRN PLAINS PER THE 00Z BISMARCK RAOB IS SHIFTING TO THE E
IN THE WLY FLOW ON THE NRN FLANK OF THE HI CENTER IN THE SCNTRL
PLAINS...THERE IS A GOOD DEAL OF MID/HI CLD EXTENDING FM ARND LK
WINNIPEG INTO THE NRN PLAINS ASSOCIATED WITH ISENTROPIC ASCENT ON
THE 290-295K SFCS /H7-575/.
TODAY...SHORT TERM MODELS ARE IN GOOD AGREEMENT SHOWING LARGER SCALE
FLOW OVER THE ENTIRE CWA SHIFTING TO THE W AS HI PRES OVER THE
SCNTRL PLAINS SHIFTS TOWARD THE OH RIVER VALLEY...WHICH SHOULD
WEAKEN THE LLVL CNVGC NOW PRESENT OVER THE E HALF AND ADVECT WARMER
H85 TEMPS/DRIER LLVL AIR TO THE W OVER THE CWA. THESE TRENDS WL TEND
TO STEADILY WEAKEN THE ONGOING LK EFFECT PCPN NOW IMPACTING MAINLY
THE E HALF OF THE CWA. THE ARRIVAL OF THE DRIER AIR WL ALSO RESULT
IN MORE SUNSHINE...WHICH WL BE DIMMED AT TIMES BY THE BKN HIER CLDS
DRIFTING INTO THE AREA FM THE NW. MIXING TO H8 ON NAM/GFS FCST SDNGS
YIELDS HI TEMPS MAINLY 45-50...EXCEPT IN THE LO 50S WHERE THE INCRSG
W WIND DOWNSLOPES OVER THE CENTRAL.
SUN NGT...AS NEXT SHRTWV/SFC LO DIGS SEWD THRU SCNTRL CANADA TO NEAR
LK WINNIPEG AND SFC HI PRES SHIFTS INTO THE OH RIVER VALLEY BY
12Z...A STRENGTHENING WSW FLOW WL DVLP OVER THE UPR LKS WITH H925
WINDS INCRSG UP TO 25-35 KTS BY 12Z MON. ALTHOUGH SOME MID/HI CLDS
ASSOCIATED WITH THE ISENTROPIC ASCENT ON THE 290K SFC WL BE OVER THE
UPR LKS...THESE CLDS WL BE RATHER THIN. PWATS AS LO AS 0.25-0.30
INCH INDICATE TEMPS WL STILL FALL FAIRLY SHARPLY OVER THOSE INTERIOR
LOCATIONS ESPECIALLY OVER THE SCNTRL THAT CAN DECOUPLE BEFORE THE
H925 FLOW STRENGTHENS TOO MUCH OVERNGT. LOCATIONS NEAR LK SUP SHOULD
BE WARMEST WITH DOWNSLOPE FLOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 503 AM EDT SUN OCT 7 2012
BY MONDAY MORNING THE UPPER GREAT LAKES WILL BE COMPLETELY WITHIN A
LARGE 500MB TROUGH THAT WILL ENCOMPASS ALL BUT THE FAR SW CORNER OF
THE NATION...EXTENDING FROM THE MAIN LOW OVER N CANADA THROUGH
HUDSON BAY.
FCST MODELS AGREE WITH THE ENHANCEMENT IN THE MAIN THROUGH SET UP
FROM S HUDSON BAY THROUGH CENTRAL SASKATCHEWAN BY MONDAY
AFTERNOON...SHIFTING TO CENTRAL MN BY DAYBREAK TUESDAY...AND SLOWLY
ACROSS LAKE SUPERIOR/UPPER MI TUESDAY. THE APEX OF THE TROUGH SHOULD
BE ACROSS THE CENTER OF THE CWA BY AT 12Z WEDNESDAY...BEFORE PUSHING
TO THE LOWER GREAT LAKES DURING THE DAY.
THE PROGRESSIVELY S SINKING /RUN TO RUN COMPARISON OVER THE PAST
COUPLE OF DAYS/ SFC LOW OVER S MANITOBA AND ND MONDAY MORNING WILL
RESULT IN INCREASED SW WINDS ACROSS THE UPPER GREAT LAKES. THE TRACK
OF THE SFC LOW IS STILL IN QUESTION...WITH THE 06/18Z RUN OF THE GFS
AROUND 6HRS FASTER THAN THE NAM/ECMWF/CANADIAN SOLUTIONS. THE 07/00Z
RUN OF THE GFS IS MUCH FARTHER TO THE N...BUT STILL TRACKING A BIT
FAST. THE TRACK WILL LIKELY BRING THE SFC LOW OVER W-CENTRAL LAKE
SUPERIOR BY 06Z TUESDAY...BEFORE SLIDING NE TO JAMES BAY BY 00Z
WEDNESDAY. GIVEN THIS TRACK...THE STRONGEST WINDS WILL LIKELY BE
AHEAD OF THE SYSTEM
/OUT OF THE SW MONDAY THROUGH MONDAY EVENING/.
TEMPERATURE WISE...INCREASED DOWNSLOPE S FLOW WILL BE COUNTERACTED
SLIGHTLY BY ADDITIONAL CLOUD COVER MONDAY AFTERNOON NEAR LAKE
SUPERIOR.
N/NW FLOW WILL RETURN TUESDAY NIGHT BEHIND THE EXITING SFC LOW.
850MB TEMPS OF -5 TO -8C MAY NOT BE ENOUGH TO CREATE MUCH MORE THAN
ENHANCED CLOUD COVER NEAR THE LAKE SUPERIOR SHORELINE TUESDAY NIGHT
INTO WEDNESDAY. HIGH PRESSURE NUDGING IN FROM THE CENTRAL PLAINS
WEDNESDAY SHOULD HELP IN PUSHING MUCH OF THE LOW LEVEL MOISTURE TO
OUR EAST. IT WILL NOT BE QUITE THAT SIMPLE THOUGH...WITH NW FLOW
ALOFT AND A CONTINUATION OF SMALLER SCALE WAVES BRINGING IN
ADDITIONAL MOISTURE.
THURSDAY THROUGH FRIDAY...
YET ANOTHER WAVE LOOKS TO SLIDE IN FROM THE NW THURSDAY OR THURSDAY
NIGHT. THE 06/12Z ECMWF WAS APPROX 12 HRS SLOWER THAN THE 06/18Z RUN
OF THE GFS WITH THIS WEAKER TROUGH. THE 07/00Z RUNS HAVE NEARLY
CORRECTED THIS ISSUE...WITH ONLY MINOR DIFFERENCES. STILL HAVE W TO
NW GALES TO 35KTS POSSIBLE OVER CENTRAL AND E LAKE SUPERIOR THURSDAY
AFTERNOON AND EVENING.
FRIDAY NIGHT THROUGH SATURDAY...
HIGH PRESSURE WILL ATTEMPT TO BUILD IN AT 500MB...WITH LITTLE MORE
THAN ZONAL FLOW BEING THE RESULT...AS THE NEXT LOW NEAR THE
4-CORNERS GETS SWEPT UP IN THE MAIN FLOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 123 AM EDT SUN OCT 7 2012
COMBINATION OF WINDS BACKING TO THE WEST AND SLIGHT WARMING ALOFT
HAS GENERALLY PUT AN END TO LAKE EFFECT SHOWERS AT SAW/IWD. SOME
-SHSN MAY CONTINUE AT CMX FOR THE NEXT COUPLE OF HOURS WITH UPSLOPE W
WIND...AND MVFR CONDITIONS ARE POSSIBLE EARLY THIS MORNING. DRIER AIR
ADVECTING IN FM THE WEST HAS BROUGHT CIGS ABV VFR AT SAW/IWD AND NOW
EXPECT VFR CONDITIONS TO CONTINUE THROUGH TAF FCST PD AT THESE
LOCATIONS AND AT CMX ONCE THE -SHSN END BY AROUND SUNRISE. ANOTHER
SURFACE TROUGH WILL APPROACH UPPER MICHIGAN SUNDAY...LEADING TO
INCREASING SWRLY WINDS AND MID- HIGH CLOUDS DURING THE MORNING HOURS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT SUN OCT 7 2012
AS A HI PRES RIDGE BUILDS TOWARD THE OHIO RIVER VALLEY THRU TONIGHT
AND LO PRES MOVES SE THRU CANADA TOWARD MINNESOTA...EXPECT A
STRENGTHENING W WIND OVER LAKE SUPERIOR. AS IS TYPICAL FOR THIS
FLOW...THE STRONGEST WINDS UP TO 30 KTS ARE MOST LIKELY IN THE AREA
BETWEEN THE KEWEENAW AND ISLE ROYALE...WHERE SOME GALE FORCE GUSTS
TO 35 KTS ARE POSSIBLE LATER TODAY.
LOW PRESSURE NEARING FROM SOUTH CENTRAL CANADA WILL RESULT IN
INCREASING SOUTHWESTERLY WINDS MONDAY /WITH S GALES TO 35KTS OVER
PORTIONS OF E LAKE SUPERIOR MONDAY INTO MONDAY EVENING/. EXPECT THE
LOW TO TRACK FROM ND AND SOUTHERN MANITOBA TO W LS BY LATE MONDAY
AFTERNOON INTO MONDAY EVENING. THE LOW WILL PUSH NE TUESDAY...AS
ANOTHER DRYING HIGH PRESSURE SYSTEM ATTEMPTS TO BUILD IN FROM THE
CENTRAL PLAINS. GUSTS WILL DIMINISH TO 20-25KTS TUESDAY NIGHT. YET
ANOTHER LOW SHOULD SKIRT ACROSS OR JUST NORTH OF LAKE SUPERIOR
WEDNESDAY NIGHT...WITH WINDS BRIEFLY INCREASING WITH GUSTS NEARING
30KTS AGAIN WEDNESDAY OUT OF THE NW. HIGH PRESSURE SHOULD FINALLY
WIN OUT TOWARD THE END OF THE WORK WEEK...WITH ANOTHER ROUND OF WEST
TO NORTHWEST GALES TO 35KTS POSSIBLE THURSDAY AFTERNOON AND
EVENING...IN BETWEEN NEARING HIGH PRESSURE TO OUR W AND EXITING LOW
PRESSURE TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ267.
LAKE MICHIGAN...
GALE WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR
LMZ248-250.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS
MARINE...KC/KF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
527 AM EDT SUN OCT 7 2012
.SYNOPSIS...
LAKE EFFECT RAIN SHOWERS WILL BE POSSIBLE EARLY THIS MORNING
ACROSS CENTRAL NEW YORK...OTHERWISE DRY WEATHER IS EXPECTED
THROUGH EARLY AFTERNOON. RAIN WILL OVERSPREAD THE AREA BY LATE
TODAY BEFORE ENDING EARLY TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT
AND THIS MAY ALLOW FOR SOME AREAS OF FROST TO FORM BY EARLY MONDAY
MORNING. MOSTLY DRY WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE
OUR NEXT SHOT AT WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVIING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SILDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS MAINTAIN SOME CONSISTENCY WITH INDICATIONS OF
BEST SHOT OF PRECIPITATION ACROSS THE ENTIRE REGION DURING THIS
PERIOD TO BE IN THE WEDNESDAY TIME FRAME. THIS IS THEN LIKELY TO
BE FOLLOWED BY DEEPENING COLD AIR AND A MAINTAINED PRESENCE OF
SHOWER CHANCES TO THE LEE OF LAKE ONTARIO THROUGH THURSDAY WITH
IMPROVED WX OVER THE SOUTHERN HALF. ANOTHER WEAK UPPER TROF AND
SFC FRONT MAY SPREAD A QUICK SHOT OF SHOWERS INTO THE AREA ON
FRIDAY. A FAIRLY LARGE CENTER OF CONTINENTAL POLAR...FALL-
LIKE...HIGH PRESSURE WORKS IN FOR AT LEAST THE FIRST HALF OF NEXT
WEEKEND.
FOLLOWED THE HPC DAY 3-7 GUIDANCE CLOSELY WITH ONLY MINOR LOCAL
ADJUSTMENTS TO TEMPERATURES.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
2 AM UPDATE...
GENERALLY VFR THROUGH EARLY THIS AFTERNOON. THE TWO EXCEPTIONS
WILL BE EARLY THIS MORNING WITH MVFR CIGS IN LAKE EFFECT CLOUDS
POSSIBLE UP NORTH..AND IFR FOG AT ELM. NOW TO THE DETAILS. AN
AREA OF LAKE EFFECT RAIN SHOWERS EAST OF LAKE ONTARIO NOW IS IN
THE PROCESS OF SHIFTING SOUTH AT THE MOMENT. ALTHOUGH NOTHING MORE
THAN A LIGHT SPRINKLE IS EXPECTED AT KSYR...MVFR CIGS WILL BE
POSSIBLE BETWEEN 07Z AND 11Z AS THIS BAND MOVES IN.
ELM FCST ALSO DIFFICULT...WITH LCL FOG CHECKLIST AND MOS GUIDANCE
INDICATING IFR ARND DAYBREAK. IT APPEARS THE LAKE CLOUDS WILL
REMAIN WEST OF THE TERMINAL...WHICH HAS ALREADY ALLOWED TEMPS TO
DROP INTO THE UPPER 30S OR CLOSE TO THE CROSSOVER TEMP FROM THIS
AFTERNOON. WITH THAT SAID UPR DECK MOVG IN FROM THE
SOUTHWEST NOW...SO THIS IS NOT A CONFIDENT FCST. WE DECIDED TO
HEDGE A BIT AND GO WITH BRIEF IFR DUE TO BR TWDS DAYBREAK. IF MORE
CLEARING OCCURS...THEN POTNL WILL EXIST FOR LIFR AT ELM.
LATER THIS AFTERNOON...-SHRA WILL SPREAD ACRS THE RGN. WE`VE
INDICATED MVFR WITH THIS PCPN AT ALL SITES XCPT SYR/RME WHERE
PROB30`S WERE USED BY EARLY TONIGHT. BEST CHC FOR RESTRICTIONS ON SUNDAY
AFTN WILL BE AFTER 22Z.
NW WINDS OPVERNIGHT 5 KTS OR LESS...THEN SW FLOW LATER TODAY
5-10 KTS BECMG NWLY ACRS CNTRL NY LATE AFTERNOON.
OUTLOOK...
SUN NIGHT...BECOMING VFR MOST AREAS. AREAS OF FOG AND RESTRICTIONS
POSSIBLE...ESPLY KELM.
MON TO TUE...VFR.
WED...VFR/MVFR. SOME SHOWERS.
THU...VFR. SOME LAKE EFFECT RAIN SHOWERS NORTH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
145 AM EDT SUN OCT 7 2012
.SYNOPSIS...
A WESTERLY FLOW OF CHILLY AIR WILL CONTINUE LAKE EFFECT RAIN SHOWERS
EAST OF LAKE ONTARIO TONIGHT WITH THE REST OF THE AREA PARTLY TO MOSTLY
CLOUDY. ANOTHER WEAK WAVE OF LOW PRESSURE WILL BRING SOME LIGHT RAIN
TO MUCH OF THE REGION SUNDAY ALONG WITH MORE COOL TEMPERATURES.
SKIES WILL BEGIN TO CLEAR SUNDAY NIGHT AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION...ALTHOUGH A FEW LAKE EFFECT SHOWERS MAY
LINGER EAST OF THE LAKES. DRY WEATHER WILL RETURN FOR MONDAY AND
TUESDAY AS HIGH PRESSURE REMAINS IN PLACE.
&&
.NEAR TERM /THROUGH TODAY/...
LAKE EFFECT RAIN ONGOING EAST OF LAKE ONTARIO LATE THIS EVENING.
OFF LAKE ONTARIO...
THIS BAND CONTINUES TO REMAIN FAIRLY WELL ORGANIZED. KTYX RADAR
SHOWING A NEARLY CONTINUOUS LINE OF PRECIP EAST-SOUTHEAST OF LAKE
ONTARIO. LIGHT TO OCCASIONALLY MODERATE RAINFALL IS ONGOING ACROSS
NORTHERN OSWEGO AND SOUTHERN LEWIS COUNTIES. JEFFERSON AND NORTHERN
LEWIS REMAIN DRY NORTH OF THE BAND. WITH THIS BAND LOCATED FURTHER
AWAY FROM THE SURFACE RIDGING ACROSS WNY IT WILL LIKELY CONTINUE TO
STAY ORGANIZED WELL INTO THE OVERNIGHT HOURS. 00Z NAM BUFKIT
INDICATED STILL CLOSE TO 10KFT FOR LAKE EL`S AND 400 J/KG OF LAKE
INDUCED CAPE. STILL EXPECT THE BAND FOR RAIN TO CONTINUE TO MOVE
SOUTHWARD OVER THE NEXT FEW HOURS. THE LATEST HRRR AND LOCAL WRF
MODELS ARE STILL IN AGREEMENT WITH THIS IDEA BUT ARE VERIFYING A
LITTLE TO FAR SOUTH COMPARED TO CURRENT RADAR. THE BAND WILL
EVENTUALLY LIE PARALLEL WITH THE SOUTHEASTERN SHORELINE OF LAKE
ONTARIO LATE TONIGHT WITH MOST OF THE RAINFALL OCCURRING ACROSS OSWEGO
COUNTY WITH PORTIONS OF NORTHERN CAYUGA AND NORTHEASTERN WAYNE
COUNTIES ALSO CATCHING SOME LIGHT RAIN.
LATE TONIGHT INTO SUNDAY MORNING AS FLOW BEGINS TO WEAKEN...LAND
BREEZE CONVERGENCE IS FORECAST TO INCREASE ALONG THE SOUTH SHORE OF
THE LAKE...WHICH MAY PRODUCE ANOTHER PERIOD OF MORE ORGANIZED LAKE
EFFECT AT THE SOUTHEAST CORNER OF THE LAKE. BY THIS TIME THE FLOW
WILL BE MUCH WEAKER...SO THE BAND SHOULD TEND TO HUG THE LAKESHORE
MORE AND NOT EXTEND VERY FAR INLAND. FINALLY BY MIDDAY SUNDAY THE
BOUNDARY LAYER FLOW BECOMES LIGHT ENOUGH TO ALLOW THE BAND TO TEA
KETTLE AND RETRACT BACK OUT OVER THE LAKE. INSTABILITY IS A LITTLE
GREATER OFF LAKE ONTARIO...AND THE BAND MAY LAST LONGER...SO EXPECT
RAINFALL POTENTIAL OF A QUARTER TO HALF INCH HERE...WITH THE
GREATEST AMOUNTS ACROSS CENTRAL AND SOUTHERN OSWEGO COUNTY.
OFF LAKE ERIE...
THE BAND EAST OF THE LAKE HAS BROKEN APART. 850 MB TEMPS ARE PLENTY
COLD ENOUGH (-2C OFF THE 00Z KBUF SOUNDING) BUT SURFACE RIDGING HAS
BUILT ACROSS MUCH OF WESTERN NY WITH A STRONG SURFACE HIGH CENTERED
OVER THE CENTRAL PLAINS. THIS SURFACE RIDGING HAS LOWERED EQUILIBRIUM
LEVELS DOWN TO AROUND 7000 FT WHICH IS MUCH TOO SHALLOW TO SUPPORT
AND RAIN IN ADDITION TO THE SURFACE RIDGING IN PLACE.
SUNDAY MORNING THERE MAY BE A BRIEF RESURGENCE OF LAKE EFFECT
ORGANIZATION AS BOUNDARY LAYER FLOW BECOMES A LITTLE MORE WESTERLY.
THIS WILL BE SHORT LIVED HOWEVER AS LOW LEVEL FLOW BECOMES VERY
LIGHT BY LATE MORNING...WITH ANY REMAINING LAKE EFFECT TENDING TO
TEA KETTLE OUT OVER THE LAKE AND NOT EXTEND INLAND.
OUTSIDE OF THE LAKE EFFECT...MOST LOCATIONS WILL SEE PARTLY TO
MOSTLY CLOUDY SKIES. LATEST IR IMAGERY SHOWS LAKE EFFECT CLOUDS OVER
MUCH OF WNY AND WITHIN THE BAND EAST OF LAKE ONTARIO. ONLY CLEAR
SPOTS AT 03Z WERE ACROSS CNY. MID LEVEL CLOUDS CAN ALSO BE SEEN ON
IR STREAMING NORTHEAST ACROSS WESTERN PA. THESE WILL INCREASE IN
COVERAGE ACROSS WESTERN NY AHEAD OF A DEVELOPING SURFACE WAVE.
SUNDAY...FOLLOWING ANY LINGERING LAKE EFFECT IN THE MORNING...OUR
ATTENTION TURNS BACK TO THE SYNOPTIC SCALE. LATEST SHORT TERM MODEL
GUIDANCE SWINGS A STRONG SHORTWAVE THROUGH THE MEAN LONGWAVE TROUGH
POSITION...CROSSING THE OHIO VALLEY AND PENNSYLVANIA DURING THE
AFTERNOON. THIS WILL INTERACT WITH A FRONTAL ZONE TO OUR SOUTH AND
PRODUCE A BAROCLINIC LEAF...WHICH WILL ACT TO INCREASE DIFFERENTIAL
THERMAL ADVECTION AND ISENTROPIC UPGLIDE ACROSS THE LOWER LAKES.
THIS WILL BRING THICKENING AND LOWERING CLOUD COVER DURING THE DAY
WITH A MORE WIDESPREAD LIGHT RAIN DEVELOPING BY MIDDAY OR EARLY
AFTERNOON...ESPECIALLY ACROSS THE SOUTHERN TIER AND FINGER LAKES
WHERE UP TO A QUARTER INCH MAY FALL. FARTHER NORTH...EXPECT THE
NORTHERN EDGE OF THE RAIN SHIELD TO CLIP THE NIAGARA FRONTIER EAST
TO ROCHESTER AND THE TUG HILL REGION WITH A LITTLE LIGHT RAIN IN THE
AFTERNOON.
THE THICKENING CLOUD COVER AND DEVELOPING RAIN WILL BRING ANOTHER
CHILLY DAY...WITH THE LOWER ELEVATIONS ONLY TOPPING OUT IN THE LOWER
50S AT BEST...WITH MID TO UPPER 40S ACROSS HIGHER TERRAIN.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
THE MAIN CONCERN FOR THE SUNDAY NIGHT THROUGH TUESDAY NIGHT PERIOD
IS THE POTENTIAL OF FROST...OR A WIDESPREAD FREEZE. THIS WOULD BE A
GOOD TIME TO ISSUE A FREEZE WATCH FOR SUNDAY NIGHT IF CONFIDENCE WAS
HIGH ENOUGH...BUT THERE IS TOO MUCH UNCERTAINTY ABOUT CLOUD COVER
AND RESULTING LOW TEMPERATURES AT THIS TIME.
A SHORTWAVE CURRENTLY MOVING INTO NE WILL BE IN THE PROCESS OF
MOVING THROUGH THE LOWER GREAT LAKES REGION BY SUNDAY AFTERNOON AND
EVENING. RAIN ACCOMPANYING THIS SYSTEM WILL MOST LIKELY AFFECT /AT
LEAST/ THE SOUTHERN TIER AND PA BEFORE MOVING EAST DURING SUNDAY
NIGHT AS THE SURFACE BASED COASTAL LOW NEAR DELMARVA MOVES FURTHER
OFFSHORE. THE END RESULT TOWARD MONDAY MORNING WILL BE CLOUDS
OVERHEAD MOVING OFF TO THE EAST...WITH A GOOD CHANCE FOR HIGH CLOUD
COVER AT LEAST OVER THE EASTERN LAKE ONTARIO REGION. IN
ADDITION...THERE SHOULD BE SOME ONGOING LAKE EFFECT RAIN SHOWERS
EAST OF THE LAKES OVERNIGHT...WITH CLOUDS SPREADING INTO THE HIGHER
TERRAIN EAST OF LAKE ONTARIO AND INTO THE SOUTHERN TIER...THE EXACT
LOCATION THAT WOULD NORMALLY BE THE COLDEST PLACES IN WESTERN NY. A
FREEZE IS POSSIBLE ON THE FRINGES OF ANY LAKE BANDS AND/OR HIGHER
CLOUD COVER...BUT AT THIS TIME IT IS TOO UNCERTAIN AS TO HOW
WIDESPREAD THE CLOUD COVER WILL BE. WILL THEREFORE ADD IN SOME
FROST INTO THE FORECAST FOR AREAS OUTSIDE OF ANTICIPATED THICKER
CLOUD COVER...BUT KEEP TEMPERATURES ABOVE THE FREEZING MARK FOR NOW.
ON MONDAY ANY LAKE EFFECT SHOULD QUICKLY END DURING THE MORNING WITH
HIGH PRESSURE MOVING INTO THE NORTHEAST. MONDAY NIGHT WILL FEATURE
MOSTLY CLEAR SKIES...SO ALTHOUGH TEMPERATURES ALOFT WILL WARM A BIT
OVER 24 HOURS...THERE WILL ONCE AGAIN BE A LOW CHANCE FOR SOME FROST
OR FREEZING CONDITIONS DUE TO RADIATIONAL COOLING. WILL HAVE A
SLIGHTLY LARGER AREA COVERED BY FROST FOR LATE MONDAY NIGHT IN THE
TRADITIONAL INLAND LOCATIONS...PRIMARILY THE SOUTHERN TIER AND WELL
EAST OF LAKE ONTARIO.
QUIET WEATHER IS EXPECTED FOR TUESDAY WITH A CONTINUED WARMING
TREND...WITH MAX TEMPERATURES APPROACHING NORMAL VALUES FOR THIS
TIME OF YEAR.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE REX BLOCK IN PLACE OVER THE EASTERN PACIFIC WILL REMAIN IN PLACE
OR V-E-R-Y SLOWLY MOVE INTO THE WESTERN US THE COURSE OF NEXT WEEK.
THEREFORE WE NEED TO LOOK ABOVE BC...NEAR THE TOP OF THE RIDGE FOR
THE NEXT FEATURE OF INTEREST. MEDIUM RANGE GUIDANCE HAS BEEN VERY
CONSISTENT BRING THE NEXT FEATURE DOWN THROUGH ALBERTA AND
SASKATCHEWAN EARLY NEXT WEEK...WITH A SURFACE LOW REMAINING IN CA
AND PIVOTING AROUND HUDSON BAY WHILE AN ASSOCIATED COLD FRONT SWEEPS
ACROSS THE GREAT LAKES REGION AND ACROSS NYS ON WEDNESDAY. THERE IS
SOME UNCERTAINTY AS TO TIMING WITH THE FRONT/PRECIPITATION...WITH
RAIN POSSIBLE EITHER WEDNESDAY OR WEDNESDAY NIGHT. WILL KEEP
FORECAST GENERALLY UNCHANGED FOR NOW WITH LIKELY RAIN IN THE WEST IN
THE AFTERNOON.
EXPECT A FAIRLY STRONG RIDGE AFTER THIS FOR THURSDAY WITH DRY
WEATHER. THEN ANOTHER FRONT DROPS ACROSS THE REGION DURING THE END
OF NEXT WEEK FOR ANOTHER CHANCE OF RAIN. TEMPERATURES DROP QUITE A
BIT BEHIND THIS NEXT FRONTAL PASSAGE...WITH 850MB TEMPERATURES DOWN
TO -7C EAST OF LAKE ONTARIO. HOWEVER...A FAIRLY STRONG RIDGE WILL
ALSO BE IN PLACE BY THE WEEKEND. RIGHT NOW LAKE EFFECT
POSSIBILITIES LOOK MINIMAL WITH A LOW LEVEL DRY AIRMASS ACROSS THE
LOWER GREAT LAKES REGION. ALTHOUGH THE CURRENT CONCERN FOR A
FROST/FREEZE IS FOR SUNDAY OR SUNDAY NIGHT...A BIGGER CONCERN MAY BE
NEXT WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
LAKE EFFECT RAIN SHOWERS WILL ORGANIZE EAST OF BOTH LAKE ERIE AND
LAKE ONTARIO OVERNIGHT. THE RAIN BANDS WILL PRIMARILY IMPACT
AREAS BETWEEN KROC AND KART OFF LAKE ONTARIO...FOCUSING ON KFZY
AND KSYR. KJHW COULD SEE SOME OF THIS ACTIVITY TOWARD 12Z SUNDAY
MORNING. OCCASIONAL MVFR CIGS AND VSBYS ALSO POSSIBLE IN THE LAKE
EFFECT. OUTSIDE OF THESE AREAS...VFR CIGS ARE EXPECTED. ON SUNDAY
LAKE EFFECT RAIN SHOWERS WILL LINGER THROUGH THE MORNING EAST OF
THE LAKES WITH AREAS OF MVFR AND LOCAL IFR. BY AFTERNOON A WEAK
WAVE OF LOW PRESSURE WILL PASS BY JUST TO THE SOUTH OF THE REGION.
THIS MAY PRODUCE A LITTLE MORE WIDESPREAD LIGHT RAIN...WITH
ASSOCIATED MVFR AND LOCAL IFR CONDITIONS ESPECIALLY ACROSS HIGHER
TERRAIN.
OUTLOOK...
MONDAY AND TUESDAY...VFR.
WEDNESDAY...AREAS OF MVFR WITH SHOWERS LIKELY.
THURSDAY...MAINLY VFR.
&&
.MARINE...
WINDS DIMINISHING STEADILY OVERNIGHT AS THE PRESSURE GRADIENT
RELAXES ACROSS THE AREA. A SMALL CRAFT ADVISORY REMAINS THROUGH
SUNDAY MORNING FOR THE EAST END OF LAKE ONTARIO AS OBSERVATIONS
THERE STILL SHOWING 20 TO 25 KT WINDS.
A WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE FOR THE REST OF SUNDAY
WITH MUCH LIGHTER WINDS...AND THE LIGHT WINDS WILL LAST INTO MONDAY
AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE LOWER LAKES.
WATERSPOUTS WILL BECOME MORE LIKELY THROUGH SUNDAY MORNING OFF LAKE
ONTARIO IN AND NEAR BANDS OF LAKE EFFECT SHOWERS AND CLOUDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR
LOZ043>045.
&&
$$
SYNOPSIS...HITCHCOCK/SMITH
NEAR TERM...SMITH
SHORT TERM...ZAFF
LONG TERM...ZAFF
AVIATION...SMITH/TMA
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT SUN OCT 7 2012
.SYNOPSIS...
A COLD FRONT OVER THE AREA WILL MOVE SOUTHEAST TO COASTAL SECTIONS
THIS MORNING. THE FRONT WILL BRIEFLY STALL OVER THE COASTAL AREAS
TODAY... BEFORE SHIFTING OFFSHORE THIS EVENING. THICK CLOUD COVER
AND A CHILLY AIR MASS WILL HOLD OVER THE REGION THROUGH MONDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 300 AM SUNDAY...
EARLY MORNING...
THE SURFACE COLD FRONT HAS PUSH SOUTH THROUGH THE AREA SINCE LAST
EVENING...NOW STRETCHING FROM KGSP TO KMEB TO KPGV. A PATCH OF
SHOWERS MOVING NORTHEAST BETWEEN KGSO AND KRDU IS BEING AIDED BY A
WEAK DISTURBANCE LOFT IN WATER VAPOR AND INCREASING ISENTROPIC
ASCENT. THE 00Z KGSO RAOB SHOWERS ENOUGH INSTABILITY ABOVE THE
STRENGTHENING COLD DOME TO SUPPORT AT LEAST A FEW SPORADIC LIGHTNING
STRIKES THROUGH EARLY MORNING. THE HEAVIER SHOWERS A PRODUCING
BETWEEN ONE TO TWO TENTHS OF AN INCH OF RAINFALL. BASED ON RAP
ISENTROPIC FIELDS AND HRRR SIMULATED REFLECTIVITY...EXPECT THESE
SHOWERS TO CONTINUE MOVING OFF TO THE NORTHEAST AND OUT OF THE
NORTHERN PIEDMONT/COASTAL PLAIN BY 10Z.
TODAY...
A SHORTWAVE CURRENTLY APPROACHING THE MID MS VALLEY REGION WILL
SWING ACROSS THE OH VALLEY REGION THIS AFTERNOON..WITH PRECIP
SPREADING EAST AND EXPANDING ALONG THE 850MB FRONT THAT HAS STALLED
FROM THE LOWER TN VALLEY TO THE MID ATLANTIC STATES. WHILE THE FLOW
AHEAD OF THE SHORTWAVE WILL STRENGTHEN THIS AFTERNOON...WINDS IN THE
295-305K LAYER STAY RELATIVELY PARALLEL TO FRONTAL ZONE AND
CROSS-SECTIONS SHOW MUCH DEEPER MOISTURE ALONG AND WEST OF THE
MOUNTAINS. THUS...WHILE OVERCAST SKIES WILL DEVELOP THIS MORNING
DUE TO MOISTENING AT THE TOP OF THE STABLE LAYER...PRECIP AMOUNTS
SHOULD BE RELATIVELY LIGHT..WITH MODELS NOW ONLY SHOWING A TENTH OF
AN INCH OR LESS IN THE NORTHWEST PIEDMONT.
TO THE SOUTH AND EAST...THE COLD FRONT WILL STALL ACROSS SC AND
SOUTHEAST NC THIS MORNING. A WEAK WAVE OF LOW PRESSURE IS FORECAST
TO MOVE FROM CENTRAL NC TOWARD THE OBX THIS AFTERNOON...WHICH SHOULD
HELP TRIGGER SOME SHOWERS AND STORMS IN THE VICINITY OF THE FRONTAL
ZONE. FORECAST SOUNDINGS AT KFAY LOOK MUCH TOO STABLE FOR ANY NEAR
SURFACE BASED CONVECTION...BUT MUCAPE FORECASTS SHOW AROUND 400-600
J/KG JUST TO THE NORTH OF THE FRONT...SO AN ISOLATED AND ELEVATED
STORM COULD BE POSSIBLE OVER THE SOUTHEAST CWA. HOWEVER...THE COLD
FRONT IS FORECAST TO SURGE FURTHER SOUTH AND EAST AFTER 18Z (IN THE
WAKE OF THE SURFACE WAVE)...WITH THE POTENTIAL FOR AN THUNDER
BECOMING LESS LIKELY WITH TIME. THE POP FORECAST WILL SHOW A STRONG
GRADIENT FROM 80 IN THE NORTHWEST TO 25 IN THE SOUTHEAST.
THE RISE IN TEMPS TODAY WILL SOMEWHAT DEPEND ON HOW MUCH PRECIP
FALLS...WITH LESS RISE EXPECTED IN THE NORTHWEST PIEDMONT WITH
PERIODS OF RAIN EXPECTED THROUGH THIS AFTERNOON. THINNER MOISTURE
PROFILES AND A LITTLE MORE HEATING NEAR THE FRONT MAY ALLOW FOR SOME
LOWER 70S IN THE FAR SOUTHEASTERN AREAS. MID 50S TO LOWER 70S
ARE EXPECTED WITH A SHARP GRADIENT ACROSS THE PIEDMONT.
TONIGHT AND MONDAY...
AS HIGH PRESSURE EXPANDS ACROSS THE OHIO VALLEY TONIGHT...COOL AND
DRIER LOW LEVEL AIR WILL WORK SOUTH INTO THE AREA WITH DEW POINTS
FALLING INTO THE 40S CWA-WIDE. THIS WILL ALLOW FOR A LITTLE MORE
COOLING AND LOWS REACHING THE 42-49 RANGE AND NO RAIN OVERNIGHT.
ANOTHER SHORTWAVE OVER CO/WY THIS MORNING WILL SWING FURTHER SOUTH
TOWARD THE TN VALLEY MONDAY...WITH A LITTLE BETTER RAIN CHANCES OVER
ALL OF CENTRAL NC AS THE 850MB DRIFTS EASTWARD AND THE RIGHT
ENTRANCE REGION OF THE PERSISTENT UPPER JET TO OUR NORTH SHIFTS
OVERHEAD. ISENTROPIC ASCENT...WHILE STRONGER...IS STILL NOT VERY
IMPRESSIVE...SO RAINFALL TOTALS MAY AGAIN BE LIGHT. HOWEVER...
TEMPS WILL LIKELY NOT RISE MUCH AT ALL ACROSS THE CWA AS A BETTER
COLD AIR DAMMING AIRMASS DEVELOPS...WITH MOST GUIDANCE INDICATING
LOW TO MID 50S...POSSIBLY 60 IN THE FAR SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 220 AM SUNDAY...
FOR MONDAY NIGHT: PATTERN REMAINS DOMINATED BY FAST MID LEVEL
CYCLONIC FLOW... ON THE COLD SIDE OF A SURFACE BOUNDARY... RESULTING
IN CHILLY AND HIGHLY UNSETTLED WEATHER. THE PARENT HIGH SUPPORTING
THE DAMMING REGIME WILL BE CENTERED OVER THE COAST OF MAINE AND
CANADIAN MARITIMES WHILE EXTENDING TO THE SW... THROUGH THE NC
FOOTHILLS AND WRN PIEDMONT. MOIST UPGLIDE AT 290K-295K IS NOT
PARTICULARLY INTENSE OVER CENTRAL NC BUT THE PRESENCE OF A DEEP
NEARLY SATURATED LAYER AT 950 MB TO 750 MB SHOULD MAKE THIS LIFT
VERY PRODUCTIVE IN TERMS OF CONDENSATION AND PRECIP... AND THE
FAST-MOVING PASSAGE OF A MID LEVEL WAVE THROUGH THE AREA SHOULD
FURTHER AUGMENT LIFT. UPPER DIVERGENCE OVER CENTRAL NC... IN THE
RIGHT ENTRANCE REGION OF THE 120+ KT UPPER JET CORE OVER AND JUST
OFF THE NORTHEAST COAST ON MONDAY... QUICKLY DIMINISHES AS THE JET
MOVES AWAY TO THE NE... AND FORECAST SOUNDINGS CONFIRM DRYING ALOFT
OVERNIGHT... HOWEVER THE COLUMN WILL REMAIN NEARLY SATURATED BELOW
750 MB WITH LOWERING CEILINGS OVERNIGHT WITHIN THE PERSISTENT
DAMMING-INDUCED STABLE LAYER. THE MOIST UPGLIDE LARGELY ENDS AFTER
MIDNIGHT... AS THE WINDS ALOFT DECELERATE AND THE MID LEVEL WAVE
EXITS ALONG WITH THE UPPER JET-RELATED FORCING FOR ASCENT. EXPECT A
GRADUAL LOWERING OF LIGHT RAIN AND DRIZZLE COVERAGE FROM SOUTH TO
NORTH THROUGH THE NIGHT... ENDING LAST IN THE FAR NORTHWEST CWA
(ROXBORO THROUGH THE TRIAD) WHERE SLOPED ASCENT WILL LINGER ALONG A
WEAK 925 MB FRONTAL ZONE. LOW CLOUDS... AREAS OF FOG... AND POCKETS
OF DRIZZLE ARE LIKELY TO PERSIST AREAWIDE THROUGH DAYBREAK. TEMPS
SHOULD DROP NO MORE THAN 10 DEGREES OR SO FROM THE PRECEDING CHILLY
DAYTIME TEMPS... YIELDING LOWS OF 42-49.
FOR TUESDAY/TUESDAY NIGHT: THE MID LEVEL CANADIAN VORTEX WOBBLES
OVER HUDSON BAY WHILE ITS TRAILING BROAD TROUGHING SHIFTS SLOWLY
FROM THE UPPER MIDWEST TOWARD MI WHILE AMPLIFYING. THE STRONG
(ROUGHLY 1030 MB) PARENT SURFACE HIGH CENTERED OVER NOVA SCOTIA
EARLY TUESDAY CONTINUES MOVING NORTHEAST OVER THE MARITIMES...
CAUSING THE TRAILING RIDGE TO LOSE ITS GRIP ON CENTRAL NC AND LEAVE
BEHIND A DISCONNECTED WEAK RESIDUAL COOL STABLE POOL. THIS
SEPARATION FROM THE SUPPLY OF COOL DRY AIR TO MAINTAIN THE DAMMING
AIR MASS WILL ALLOW IT TO BECOME VULNERABLE TO HORIZONTAL DISPERSION
AND CONVECTIVE MIXING AS THE DRIER AIR ALOFT ALLOWS STRONG HEATING
FROM THE TOP... ALTHOUGH TYPICALLY THIS EROSION PROCESS OFTEN TAKES
QUITE A WHILE PARTICULARLY WITH A STABLE LAYER THIS DEEP. WILL BE
SLOW TO GET RID OF THE WEDGE-SUPPORTED CLOUDS ON TUESDAY... TRENDING
GRADUALLY TO PARTLY CLOUDY LATE IN THE DAY. THE WEAK HIGH WILL DRIFT
BACK TOWARD THE SW TO OVER THE INTERIOR SOUTHEAST STATES TUESDAY
NIGHT... AND WITH THE RESULTING MODIFICATION OF THE AIR MASS...
THICKNESSES WILL START TO REBOUND BUT SHOULD STILL HOLD WELL BELOW
NORMAL FOR ANOTHER DAY GIVEN THE DELAYED HEATING. EXPECT MODEST
WARMING WITH HIGHS OF 60-68. EXPECT FAIR SKIES TUESDAY NIGHT WITH
CONTINUED DRYING ALOFT... ALTHOUGH RECOVERING SURFACE DEW POINTS
COMBINED WITH LIGHT WINDS IS LIKELY TO LEAD TO DEVELOPMENT OF GROUND
FOG OVERNIGHT. LOWS 47-52. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 250 AM SUNDAY...
EXPECT GENERALLY DRY WEATHER BUT WITH ROLLER COASTER TEMPS AS A
SUCCESSION OF FRONTS DROPS THROUGH THE REGION.
FOR WEDNESDAY/WEDNESDAY NIGHT: THE MID LEVEL TROUGH AXIS SWINGS
SWIFTLY ENE THROUGH THE GREAT LAKES AND NORTHEAST STATES... DRAGGING
A SURFACE COLD FRONT THROUGH CENTRAL NC WEDNESDAY AFTERNOON. GIVEN
THAT THE SURFACE HIGH CENTER WILL BE LOCATED TO OUR SOUTH AND SW...
THERE WILL BE LITTLE TO NO MOISTURE FLUX AHEAD OF THE FRONT... THUS
IT SHOULD COME THROUGH DRY. THICKNESSES ARE PROJECTED TO BE AT OR
JUST ABOVE NORMAL WEDNESDAY... TRANSLATING TO HIGHS IN THE MID TO
UPPER 70S. YUKON-SOURCE HIGH PRESSURE BUILDING IN BEHIND THE FRONT
SHOULD SEND THICKNESSES PLUNGING BACK DOWN BELOW NORMAL... WITH LOWS
IN THE MID 40S TO NEAR 50.
FOR THURSDAY THROUGH SATURDAY: THE SURFACE HIGH IS EXPECTED TO BUILD
OVER NC ON THURSDAY... WITH BROAD/FAST/CYCLONIC MID LEVEL FLOW FROM
SW CANADA ACROSS THE NORTHEAST STATES. FAIR AND DRY THURSDAY WITH
INITIALLY COOL BUT MODERATING TEMPS. A MINOR WAVE DROPS INTO THE
LONGWAVE TROUGH OVER THE GREAT LAKES... AND THIS ACCOMPANYING
SURFACE COLD FRONT WILL APPROACH NC FROM THE NNW ON FRIDAY. ONCE
AGAIN... VERY LITTLE MOISTURE IS AVAILABLE AHEAD OF AND ALONG THE
FRONT AND LIFT WILL BE WEAK... SO EXPECT NO MORE THAN ISOLATED
SHOWERS AT BEST. TEMPS SHOULD BOUNCE BACK UP TO NEAR NORMAL AHEAD OF
THE FRONT FRIDAY. YET ANOTHER COOL HIGH BUILDS IN BEHIND THE FRONT
FROM THE NORTH... ITS CENTER MOVING FROM OVER SW MI TO OFF THE
NJ/DELMARVA COAST FROM FRIDAY EVENING THROUGH SATURDAY AS IT RIDGES
SOUTHWARD THROUGH CENTRAL NC. EXPECT A SLIGHT COOLDOWN OF AROUND A
CATEGORY FOR SATURDAY... WITH CONTINUED DRY WEATHER. -GIH
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 135 AM SUNDAY...
SHOWERS CURRENTLY MOVING NORTHEAST THROUGH THE PIEDMONT ARE CAUSING
BRIEF MVFR CEILINGS AND WILL MOVE OVER KRDU BY 08Z. THE COLD FRONT
THAT HAS BEEN MOVING SOUTH THROUGH THE AREA HAS NOW SETTLED SOUTH OF
KFAY...ALTHOUGH THERE IS ENOUGH ELEVATED INSTABILITY NORTH OF THE
FRONT FOR A FEW LIGHTNING STRIKES WITH THE HEAVIEST SHOWERS.
ELSEWHERE...VFR CONDITIONS ARE CURRENTLY OBSERVED BUT WILL
DETERIORATE THIS MORNING AS MOISTURE CONTINUES TO INCREASE ON THE
NORTH/COOL SIDE OF OF THE FRONT. FORECAST SOUNDINGS GENERALLY AGREE
ON MVFR CEILINGS LOWERING TO AROUND 1500 FT BY MIDDAY WITH THE
CHANCE FOR RAIN HIGHEST AT KGSO/KINT. SOME BREAKS OR LIFTING OF
CEILINGS AND SCATTERED SHOWERS MAY DEVELOP IN THE VICINITY OF THE
FRONT...BUT THE FRONT ITSELF IS EXPECTED TO REMAIN SOUTH AND EAST OF
KFAY/KRWI...SUCH THAT THE CONFIDENCE IN SHOWERS OR AN ISOLATED STORM
IS TOO LOW FOR MENTION IN THE KFAY TAF.
SOME DRYING FROM THE NORTH IS EXPECTED THIS EVENING...MOSTLY AFTER
00Z...AND THUS CEILINGS SHOULD EVENTUALLY SCATTER AND LIFT TO VFR AT
MOST SITES PRIOR TO MIDNIGHT. HOWEVER...ANOTHER DISTURBANCE ALOFT
IS EXPECTED TO IMPACT THE AREA MONDAY...WITH WIDESPREAD MVFR/IFR
CEILINGS TO REDEVELOP.
OUTLOOK...
LOW CEILINGS WILL LIKELY CONTINUE THROUGH AT LEAST TUESDAY...WITH
IMPROVEMENT IN AVIATION CONDITIONS BY THE MIDDLE TO END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...BLS
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
357 AM EDT SUN OCT 7 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL TRACK ACROSS THE REGION FROM THE
WEST AND OVER A LAYER OF COOLER AIR. THIS WILL RESULT IN A WET AND
COOL DAY SUNDAY. MORE RAIN AND COOL TEMPERATURES ARE EXPECTED MONDAY
AS ANOTHER UPPER LEVEL DISTURBANCE ENTERS FROM THE SOUTHWEST.
BY TUESDAY...DRIER CONDITIONS WILL ARRIVE AND CONTINUE INTO THE
LATER PART OF THE WEEK UNDER HIGH PRESSURE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM EDT SUNDAY...
WATER VAPOR SATELLITE IMAGERY INDICATES A WEAK SHORTWAVE ACROSS
EASTERN KY INTO CENTRAL TN. THIS FEATURE IS IN ADVANCE OF A STRONGER
UPPER LEVEL DISTURBANCE LOCATED ACROSS IOWA INTO MO. HRRR AND LOCAL
WRF MODELS DEPICT THIS AREA OF RAIN WELL...UNDER THE RR QUAD OF A
LIFTING UPPER LEVEL JET. WITH GOOD ISENTROPIC LIFT CONTINUING INTO
EARLY AFTERNOON AND THE APPROACH OF MIDWESTERN UPPER LEVEL
SHORTWAVE...PRECIP SHOULD EXPAND IN COVERAGE. AS A RESULT...WILL
CONTINUE TO CARRY LIKELY POPS INTO THE EARLY AFTERNOON.
BEHIND THIS SYSTEM...LOW LEVEL WINDS VEER TO THE NORTHWEST AND
ISENTROPIC DOWNGLIDE BEINGS LATE THIS AFTERNOON/EARLY THIS
EVENING...WHICH WILL GRADUALLY BRING AN END TO THE PRECIP.
CLOUDS...WEAK CAA...AND PRECIP WILL KEEP TEMPERATURES FROM RISING
MUCH AT ALL TODAY. IN FACT...TEMPS MAY DROP TODAY.
THEREFORE...LEANED TOWARD THE COOLER MAV AND LOCALLY DERIVED MOS
GUIDANCE FOR HIGHS TODAY.
THE NEXT UPPER LEVEL SYSTEM ZIPPING INTO THE LOWER OHIO VALLEY BY
LATE SUNDAY NIGHT/EARLY MONDAY MORNING WILL BACK LOW LEVEL WINDS AND
SET UP A BAROCLINIC ZONE ACROSS THE SOUTHERN PORTION OF OUR FORECAST
AREA LATE TONIGHT. THIS MAY GENERATE SOME LIGHT PRECIP IN THIS
REGION...AND KEPT SMALL POPS HERE LATE TONIGHT. IN THE NORTH...THE
THREAT FOR FROST APPEARS LOW WITH A WET GROUND/WARM SOIL TEMPS AND
CLOUD COVER. IF ANY CLEARING CAN BE MAINTAINED...SOME PATCHY FROST
IN THE DEEP MOUNTAIN VALLEYS FROM BURKES GARDEN INTO SOUTHEAST WV
MAY DEVELOP.
WITH THE INCREASE IN CLOUDS...USED A MAV/MET MIX FOR LOWS WHICH ARE
CLOSE TO OUR LOCALLY DERIVED MOS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
A JET COUPLET PROVIDING DIFFLUENCE ALOFT WILL COMBINE WITH
FRONTOGENESIS JUST ABOVE THE GROUND ACROSS SE WEST VA TO GENERATE
LIGHT RAIN ON MONDAY MOSTLY BLUE RIDGE AND WEST. ALTHOUGH QPF WILL
BE SMALL...POSSIBLY ONLY A FEW HUNDREDTHS...SPOTTY DRIZZLE WILL HELP
TO MAKE THIS A DAMP AND COOL DAY. WITH PRECIP AND E TO NE FLOW
CONTINUING...CAN`T SEE TEMPS GOING MUCH OF ANYWHERE...AND ALL OF THE
GUIDANCE WITH THE EXCEPTION OF THE LOCALLY BIAS CORRECTED ECMWF
LOOKS TOO WARM. QUITE POSSIBLE SOME OF THE COOLEST SPOTS DON`T EVEN
REACH 45F WITH THE POSSIBILITY THAT MANY PLACES DON`T REACH 50F.
CLOUDS BREAKING LATE MONDAY NIGHT SHOULD KEEP TUESDAY MORNING LOW
TEMP A FEW WARMER THAN GUIDANCE...AND A RATHER WET AND WARM GROUND
WITH TEMPS NOT FALLING INTO THE 30S UNTIL LATE SHOULD PRECLUDE ANY
FROST. WITH ABUNDANT LLVL MOISTURE AND EASTERLY COMPONENT CONTINUING
BLUE RIDGE AND EAST...HELD ONTO CLOUDS AND WENT WITH MAX T CLOSER TO
THE 2M NAM VALUES TUESDAY. WEDGE FIGURES TO BE SLOWER TO LIFT OUT
THAN OTHER MODELS DEPICT. THIS COULD BE ONE OF THOSE DAYS WHERE BCB
IS WARMER THAN ROA AND LWB IS WARMER THAN DAN/LYH. CLOUDS SHOULD
BREAK WEST OF THE BLUE RIDGE WITH MORE WESTERLY COMPONENT TUESDAY.
SHOWERS SHOULD CRUMBLE ACROSS WEST VA WITH FRONT THAT APPROACHES ON
WEDNESDAY WITH DEEP DOWNSLOPING FLOW AHEAD OF IT. BIG TEMP REBOUND
THOUGH BLUE RIDGE AND EAST...EASILY THE BEST DAY OF THE NEXT SEVERAL
WITH MAX T ONCE AGAIN IN THE 70S ON WEDNESDAY. A BETTER DRY PUNCH
SETS THE STAGE FOR SOME NEAR FREEZING TEMPS PERHAPS THURSDAY MORNING
ACROSS SE WEST VA...EXTREME SW VA AND NW NC.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 400 PM EDT SATURDAY...
ANOTHER FRONTAL BOUNDARY APPROACHES DURING THE WEEKEND AND
ARRIVES EARLY NEXT WEEK...ALLOWING TEMPERATURES TO MODERATE.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AS OF 130 AM EDT SUNDAY...
AN APPROACHING UPPER LEVEL DISTURBANCE WILL ENHANCE THE CHANCES OF
RAIN TODAY. IN ADVANCE OF THIS SYSTEM...CEILINGS HAVE BEEN
DROPPING INTO THE MVFR CATEGORY...AND EVEN IFR CATEGORY IN SOME
MOUNTAIN LOCATIONS IN NORTHWEST NORTH CAROLINA. EXPECT THIS
LOWERING TREND TO CONTINUE...ESPECIALLY IN THE MOUNTAINS EARLY
THIS MORNING...WITH RAIN DEVELOPING BETWEEN 10-13Z.
MVFR TO POCKETS OF IFR CEILINGS WILL BE FOUND THROUGH THE DAY.
ONCE THE UPPER LEVEL SYSTEM MOVES EAST AND WEAK LOW LEVEL
NORTHWEST FLOW FORMS...EXCEPT A CEILINGS TO RISE THIS EVENING.
THESE IMPROVING CONDITIONS WILL ONLY BE TEMPORARY AS ANOTHER UPPER
LEVEL SYSTEM MOVING OVER THE REGION MONDAY WILL BRING WIDESPREAD
MVFR/IFR CIGS AND LIGHT PRECIPITATION. HIGH PRESSURE BUILDING
OVER THE AREA FOR TUESDAY WILL FINALLY BRING VFR CONDITIONS
THAT ARE EXPECTED TO LAST THROUGH THURSDAY...ALTHOUGH A PERIOD OF
MVFR CIGS POSSIBLE IN THE MTNS WITH A COLD FRONTAL PASSAGE
WEDNESDAY.
&&
.EQUIPMENT...
THE KFCX DOPPLER RADAR...WHICH SERVES ROANOKE AND THE SURROUNDING
AREAS...WILL REMAIN DOWN FOR THE NEXT FEW DAYS AS THE INSTALLATION
OF THE NEW DUAL-POL TECHNOLOGY CONTINUES. THE RADAR MAY RETURN TO
SERVICE AS EARLY AS THE MIDDLE OF NEXT WEEK.
NEIGHBORING DOPPLER RADARS AT STERLING VA (KLWX)...WAKEFIELD VA
(KAKQ)...RALEIGH NC (KRAX)...GREENVILLE-SPARTANBURG SC
(KGSP)...MORRISTOWN TN (KMRX)...AND CHARLESTON WV (KRLX) WILL
CONTINUE TO PROVIDE COVERAGE OVER PARTS OF THE KFCX AREA DURING
THIS TIME FRAME.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KM/PM
NEAR TERM...PH
SHORT TERM...KM
LONG TERM...KK
AVIATION...PH
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1152 PM CDT SAT OCT 6 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
252 PM CDT SAT OCT 6 2012
MAIN FORECAST CONCERNS ARE ON FREEZE POTENTIAL TONIGHT...NEAR
CRITICAL FIRE WEATHER CONDITIONS SUNDAY AND MONDAY...AND FINALLY
PRECIPITATION CHANCES FOR MONDAY NIGHT AND TUESDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED RIDGING OVER THE NORTHEAST PACIFIC AND ALONG THE
WEST COAST OF THE U.S....WHILE DEEP TROUGHING WAS PRESENT OVER
CENTRAL AND EASTERN CANADA SOUTHWARD INTO THE CENTRAL PLAINS AND
OHIO RIVER VALLEY. WITHIN THE TROUGHING...A SHORTWAVE TROUGH
EXTENDED EAST-WEST ACROSS THE FORECAST AREA AND WEST TOWARDS
NEBRASKA. UNDERNEATH THIS SHORTWAVE TROUGH WAS AN AREA OF BROKEN
STRATUS ACROSS THE FORECAST AREA TO NEAR DULUTH. MUCH OF THIS
STRATUS WAS SITUATED AT 750MB OR BELOW PER 12Z SOUNDINGS FROM
INL...MPX AND GRB. THE REASON THE DECK IS NOT A SOLID OVERCAST IS
THAT THE SOUNDINGS DO NOT SHOW COMPLETE SATURATION. IN FACT...SOME
OF THE STRATUS FORMATION HAS BEEN DUE TO DAYTIME HEATING...NOTED
BY HOLES THAT FILLED IN DURING THE MORNING. FARTHER TO THE
NORTHWEST ON WATER VAPOR...A SHORTWAVE TROUGH WAS EVIDENT IN
SOUTHERN SASKATCHEWAN DROPPING DOWN THE EAST SIDE OF THE NORTHEAST
PACIFIC RIDGE. LACK OF LOW LEVEL MOISTURE SEEN ON THE 12Z THE PAS
MANITOBA SOUNDING HAS RESULTED IN THE SHORTWAVE JUST PRODUCING A
BAND OF MID AND HIGH CLOUDS. AT THE SURFACE...HIGH PRESSURE WAS
SITUATED OVER THE CENTRAL PLAINS WITH A RIDGE AXIS EXTENDING
NORTHEAST INTO NORTHERN MINNESOTA. 850MB TEMPS CHILLY OVER THE
FORECAST AREA...BETWEEN -5 AND -7C PER 12Z RAOBS...OR 2 STANDARD
DEVIATIONS BELOW NORMAL.
TONIGHT AND SUNDAY...SHORTWAVE TROUGH OVER SOUTHERN SASKATCHEWAN IS
PROGGED TO KEEP DROPPING SOUTHEAST THROUGH THE DEEP UPPER TROUGH...
CROSSING THE FORECAST AREA SUNDAY AFTERNOON. THIS TROUGH WILL DO A
COUPLE OF THINGS. FIRST...THE SURFACE RIDGE AXIS OVER MINNESOTA
WILL GET PUSHED DOWN OVER THE FORECAST AREA TONIGHT. AS THE RIDGE
AXIS AND THE DRY AIR ASSOCIATED WITH IT MOVE IN...SKIES WILL
CLEAR. WINDS SHOULD DECOUPLE AS WELL...EXCLUDING THE HIGHER
TERRAIN OF SOUTHEAST MINNESOTA. GIVEN THE COOL DAY TODAY...THE
SETUP CERTAINLY FAVORS LOWS DROPPING INTO THE 20S AS HAS BEEN
FORECAST THE PAST FEW DAYS. SOME OF THE TYPICAL COLD SPOTS IN
WISCONSIN COULD EVEN HIT THE UPPER TEENS. FREEZE WARNINGS
THEREFORE STILL LOOK GOOD WITH THIS LIKELY BEING THE END OF THE
GROWING SEASON. THE SECOND THING THE SHORTWAVE TROUGH WILL DO IS
TO SPREAD THE CIRRUS AND SOME MID CLOUDS SEEN UP IN SOUTH CENTRAL
CANADA ACROSS THE FORECAST AREA. REGARDING TEMPERATURES...
DOWNSLOPING OF AIR OFF THE ROCKIES AHEAD OF THE SHORTWAVE TROUGH
WILL ALLOW A PLUME OF WARMER 925-850MB AIR TO ADVECT INTO THE
FORECAST AREA. BY 18Z... 925MB AND 850MB TEMPS RISE TO 2-4C AND -3
TO -5C RESPECTIVELY. COMBINE THESE WITH AN INCREASING SOUTHWEST
WIND AS THE SURFACE RIDGE DROPS SOUTH AND HIGHS SHOULD BE ABLE TO
REACH INTO THE LOW TO MID 50S. DRY DEWPOINTS IN THE TEENS WILL
HELP RELATIVE HUMIDITIES PLUMMET INTO THE 20-30 PERCENT
RANGE...RAISING SOME FIRE WEATHER CONCERNS. THESE ARE NOTED IN THE
FIRE WEATHER DISCUSSION BELOW.
SUNDAY NIGHT AND MONDAY...ATTENTION TURNS TO A SHORTWAVE CURRENTLY
WELL UP TO THE NORTHWEST...NEAR THE NORTHWEST CORNER OF THE
NORTHWEST TERRITORIES. MODELS HAVE BEEN VERY CONSISTENT OF DROPPING
THIS SHORTWAVE INTO THE DEEP TROUGH...REACHING SOUTHERN PORTIONS OF
SASKATCHEWAN AND MANITOBA BY 12Z MONDAY. AS THE SHORTWAVE DROPS
SOUTH...A DEEPENING SURFACE LOW ACCOMPANIES IT...WHICH SHOULD REACH
FAR SOUTHERN MANITOBA BY 12Z MONDAY. THIS DEEPENING LOW WILL HELP TO
INCREASE THE SOUTHWEST WINDS EVEN MORE OVER THE FORECAST AREA...AND
ALSO ENHANCE THE DOWNSLOPE EFFECT OFF THE ROCKIES. AS SUCH...925 AND
850MB TEMPS CLIMB TO 6C AND 4C RESPECTIVELY AT 12Z MONDAY. THIS WARM
ADVECTION IS LIKELY TO RESULT AN INCREASE OF MID AND HIGH CLOUDS...
ESPECIALLY AFTER MIDNIGHT SUNDAY NIGHT AND HEADING INTO THE DAY
MONDAY. THESE CLOUDS COMBINED WITH THE WINDS WILL HELP PRODUCE A
MUCH WARMER NIGHT...ALBEIT STILL BELOW NORMAL...MAINLY IN THE 30S.
AFTER 12Z MONDAY...MODELS DIFFER A BIT ON THE TRACK...DEPTH AND
SPEED OF THE SHORTWAVE TROUGH AND SURFACE LOW. OVERALL...THOUGH...
THE GENERAL THEME IS FOR THE SHORTWAVE AND SURFACE LOW TO HEAD
EAST...LIKELY ALONG THE ONTARIO/MN BORDER. COLD FRONT ASSOCIATED
WITH THE LOW STAYS TO OUR WEST...ONLY REACHING ALBERTA LEA BY 00Z.
925MB AND 850MB TEMPS CONTINUE TO WARM AHEAD OF THIS FRONT...TOPPING
OUT AT 12-14C AND 6-8C RESPECTIVELY. WITH A TIGHT PRESSURE GRADIENT
AND MIXING RESULTING IN BREEZY SOUTHWEST WINDS...ALONG WITH DRY LOW
LEVEL AIR...WE SHOULD BE ABLE TO MIX TO NEAR 850MB. ONLY CAVEAT IS
THE MID/HIGH CLOUDS...WHICH LOOK TO INCREASE AND THICKEN THROUGH THE
DAY. ANY PRECIPITATION WITH THESE CLOUDS SHOULD STAY NORTH OF THE
FORECAST AREA PER MODEL CONSENSUS. HIGHS IN THE 60S STILL ARE
REASONABLE...PERHAPS GETTING CLOSE TO 70 WEST OF THE MISSISSIPPI
RIVER. FIRE WEATHER CONCERNS EXIST AGAIN WITH THE BREEZY SOUTHWEST
WINDS...TEMPERATURES AND LOW RELATIVE HUMIDITIES. SEE FIRE WEATHER
DISCUSSION BELOW.
MONDAY NIGHT AND TUESDAY...MODELS SHOW YET ANOTHER FAIRLY STRONG
SHORTWAVE DROPPING DOWN THE EAST SIDE OF THE NORTHEAST PACIFIC
RIDGE...DIGGING INTO NORTH DAKOTA BY 12Z TUESDAY AND THEN INTO
SOUTHERN MINNESOTA BY 00Z WEDNESDAY. THIS SHORTWAVE SHOULD HELP TO
ENHANCE LIFT IN THE WAKE OF THE COLD FRONT...ON TOP OF THE
POST-FRONTAL MID LEVEL FRONTOGENESIS THAT WILL ALREADY EXIST. SO
ONCE THE COLD FRONT MOVES EAST THROUGH THE FORECAST AREA...WHICH
GRADUALLY OCCURS DURING THIS PERIOD UNTIL THIS SHORTWAVE CAN CATCH
UP...ANTICIPATE A BAND OF RAIN TO DEVELOP. THIS SIGNAL OF THE BAND
OF RAIN CONTINUES TO GET STRONGER...WITH THE 06.12Z GFS...NAM...
UKMET...CANADIAN AND ECMWF ALL DEPICTING IT. AS SUCH...HAVE RAISED
PRECIPITATION CHANCES UP TO AROUND 40. FURTHER INCREASES WILL LIKELY
BE NEEDED IF THIS SIGNAL PERSISTS. PRECIPITABLE WATER VALUES ARE
ONLY AROUND 0.75 OF AN INCH...SO MOISTURE IS NOT THAT GREAT...BUT
THE FORCING SHOULD BE ABLE TO SQUEEZE OUT SOME LIGHT PRECIPITATION.
WITH PLENTY OF CLOUDS MONDAY NIGHT AND THE SLOW COLD FRONTAL
PASSAGE...LOWS IN THE 40S SUGGESTED BY MAV/MET GUIDANCE SEEM
REASONABLE. 850MB TEMPS DO GRADUALLY FALL DURING THE DAY
TUESDAY...BOTTOMING OUT AROUND 0C BY 00Z. NEVERTHELESS...HIGHS
SHOULD BE ABLE TO TOP OUT IN THE 50S...COOLEST IN THE NORTHWEST
WHICH ENDS UP MOSTLY BEHIND THE FRONT FOR THE ENTIRE DAY.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
252 PM CDT SAT OCT 6 2012
GOOD MODEL AGREEMENT EXISTS BETWEEN THE 06.12Z ECMWF/GFS/CANADIAN
AND GFS ENSEMBLES ABOUT A PATTERN SHIFT OCCURRING DURING THE LONG
TERM FORECAST...WITH THE CURRENT DEEP TROUGH LIFTING OUT ON FRIDAY.
WE STILL HAVE ONE MORE POTENT SHORTWAVE TO DEAL WITH DROPPING THE
TROUGH PRIOR TO LIFT-OUT...PROGGED TO CROSS LAKE SUPERIOR LATE
THURSDAY. AFTER FRIDAY...MODELS SHOW AN UPPER LOW...CURRENTLY JUST
OFF THE COAST OF CALIFORNIA...LIFTING OUT OF THE SOUTHWESTERN U.S..
EXACTLY HOW FAST THIS EJECTION OCCURS THE MODELS ARE ALL OVER THE
PLACE...WITH THE LATEST 06.12Z GFS THE FASTEST AMONGST ALL MODELS
AND PAST 1-2 DAYS OF RUNS OF THE MODEL. THE GFS HAS THIS DEEP LOW
LIFTING UP INTO SOUTHERN MINNESOTA BY 00Z SUNDAY. EJECTING UPPER
LOWS OUT OF THE SOUTHWESTERN U.S. ARE ALWAYS PROBLEMATIC FOR
MODELS...SINCE THEY HINGE ON UPPER TROUGHS CROSSING THE PACIFIC.
THEREFORE...HAVE LOW CONFIDENCE ON ANY SOLUTION AT THIS POINT...
THOUGH IT WOULD NOT BE SURPRISING IF A SLOWER IDEA ENDS UP PANNING
OUT PER MODEL BIASES.
IN THE WAKE OF TUESDAYS SHORTWAVE...A RIDGE OF HIGH PRESSURE IS
FORECAST TO BUILD IN FOR WEDNESDAY. ANOTHER SHOT OF COOL AIR COMES
WITH THIS RIDGE WITH 850MB TEMPS FALLING TO AROUND -4C. THUS...
TUESDAY NIGHT AND WEDNESDAY WILL BE COOL...BUT NOT NEARLY AS COLD AS
TODAY OR TONIGHT. COULD BE SOME LINGERING PRECIP TUESDAY EVENING IN
THE SOUTHEASTERN THIRD OF THE AREA...ASSOCIATED WITH TUESDAYS
SHORTWAVE...OTHERWISE EXPECT DRY CONDITIONS. WITH THE THURSDAY
SHORTWAVE DROPPING DOWN INTO LAKE SUPERIOR...WE GET ANOTHER COLD
FRONT TO MOVE THROUGH THE FORECAST AREA. DUE TO LIMITED SPACING
BETWEEN THE CANADIAN RIDGE OF HIGH PRESSURE AND THIS FRONT...NOT
ANTICIPATING ANY POST-FRONTAL PRECIPITATION. AHEAD OF THE FRONT...A
SURGE OF 4-6C 850MB AIR IS PROGGED TO COME INTO THE AREA ON STRONG
SOUTHWEST WINDS. SO WE COULD HAVE ANOTHER NEAR CRITICAL FIRE WEATHER
DAY...PARTICULARLY SOUTH OF I-90. ANOTHER COOLER HIGH PRESSURE AREA
IS SLATED TO DROP DOWN INTO OUR REGION FOR FRIDAY...WITH 850MB TEMPS
DROPPING BACK TO AROUND -4C AT 12Z. FOR FRIDAY NIGHT AND SATURDAY...
HAVE FOLLOWED THE CONSENSUS APPROACH AND SPREADING CHANCES OF
PRECIPITATION INTO THE AREA FROM THE SOUTHWEST. THESE ARE ALL DUE TO
WARM...MOIST AIR ADVECTION OUT OF THE GULF OF MEXICO COMING INTO THE
COLDER AIRMASS SITUATED OVER THE FORECAST AREA. MORE REFINEMENT OF
THESE CHANCES WILL COME DURING THE NEXT SEVERAL DAYS AS TIMING OF
THE UPPER LOW EJECTION BECOMES MORE CERTAIN. SHOULD SEE A GRADUAL
WARM UP IN TEMPERATURES TOO WITH THE WARMER AIR ADVECTING INTO THE
AREA. HIGHS BY SATURDAY STILL LOOK BELOW NORMAL BUT ONLY 5 OR SO
DEGREES...NOT LIKE THE 15-20 AS OF LATE.
&&
.AVIATION...THROUGH 06Z MONDAY
1151 PM CDT SAT OCT 6 2012
INFRARED SATELLITE IMAGERY SHOWS BACK EDGE OF STRATUS DECK FROM
NORTHWEST WISCONSIN TO NEAR KAEL. THE BACK EDGE HAS BEEN SLOWLY
WORKING ITS WAY SOUTHEAST AND MODELS CONSISTENT IN SHOWING THIS
BACK EDGE WILL MAKE IT TO KRST AROUND 07Z AND KLSE BETWEEN 08Z-
09Z. UNTIL THEN CEILINGS WILL RANGE FROM 050-060K FEET. AFTER THAT
JUST SOME HIGH CLOUDS ARE EXPECTED WITH VFR CONDITIONS THROUGH THE
REMAINDER OF THE TAF PERIOD.
&&
.FIRE WEATHER...SUNDAY INTO MONDAY
252 PM CDT SAT OCT 6 2012
NEAR CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE BOTH SUNDAY AND
MONDAY. SETTING THE STAGE FOR THESE CONDITIONS IS THE MODERATE TO
EXTREME DROUGHT CONDITIONS IN PLACE ACROSS THE AREA...ALONG WITH A
KILLING FREEZE EXPECTED TONIGHT.
FOR SUNDAY...SOUTHWEST WINDS ARE EXPECTED TO INCREASE IN THE WAKE OF
A RIDGE OF HIGH PRESSURE DROPPING SOUTH ACROSS THE AREA TONIGHT.
THESE WINDS SHOULD BE SUSTAINED IN THE 10-15 MPH RANGE WITH GUSTS OF
12-22 MPH...STRONGEST ACROSS SOUTHEAST MINNESOTA. DEWPOINTS ARE
LIKELY TO STILL BE LOW...THANKS TO MIXING OF DRY AIR ALOFT AND THE
RECENT COLD NIGHT. HOWEVER...LINGERING COLD AIR THAT ONLY SLOWLY
MODIFIES WILL ONLY ALLOW HIGH TEMPERATURES TO TOP OUT IN THE LOW TO
MID 50S. THESE TEMPERATURES COMBINED WITH THE DEWPOINTS SHOULD
PRODUCE MINIMUM RELATIVE HUMIDITIES IN THE 20-30 PERCENT RANGE...
LOWEST SOUTH AND WEST OF I-94. THEREFORE...THE MAIN LIMITING FACTORS
FOR RED FLAG CONDITIONS WOULD BE THE TEMPERATURES AND WINDS.
FOR MONDAY...A STRENGTHENING LOW PRESSURE SYSTEM DROPPING SOUTH OUT
OF CENTRAL CANADA INTO NORTHERN MINNESOTA WILL RESULT IN A TIGHTER
PRESSURE GRADIENT ACROSS THE AREA. AS SUCH...STRONGER WINDS ARE
ANTICIPATED...IN THE 15-25 MPH RANGE WITH GUSTS OF 20-35 MPH.
HIGHEST WINDS ARE LIKELY WEST OF THE MISSISSIPPI RIVER. THESE WINDS
SHOULD BRING UP A LITTLE MORE MOISTURE...BUT HIGH TEMPERATURES WILL
MOSTLY COUNTERACT IT BY JUMPING INTO THE 60S. THEREFORE...MINIMUM
RELATIVE HUMIDITIES ARE ONLY SLIGHTLY HIGHER...BETWEEN 25-35
PERCENT...LOWEST ALONG/WEST OF THE MISSISSIPPI RIVER. GIVEN THE
SLIGHTLY HIGHER MINIMUM RELATIVE HUMIDITIES...TEMPERATURES STILL
SLIGHTLY COOL AND ESPECIALLY POTENTIAL FOR A LOT OF CLOUDS...
CONDITIONS AGAIN JUST LOOK NEAR CRITICAL. THE CLOUDS COULD BE
QUITE PROBLEMATIC BY KEEPING RELATIVE HUMIDITIES HIGHER THAN
EXPECTED.
PER COORDINATION WITH AREA FIRE WEATHER AGENCIES...HAVE HELD OFF
ON ANY FIRE WEATHER WATCHES AT THIS TIME.
LOOKING AHEAD...ANOTHER NEAR CRITICAL FIRE WEATHER DAY COULD OCCUR
SOUTH OF I-90 ON THURSDAY...AHEAD OF A CANADIAN COLD FRONT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
252 PM CDT SAT OCT 6 2012
WI...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR WIZ032-033-041-
053>055-061.
MN...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR MNZ079-088-096.
IA...FREEZE WARNING FROM 1 AM TO 8 AM CDT SUNDAY FOR IAZ011-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS DENVER CO
924 AM MDT SUN OCT 7 2012
.UPDATE...PATCHY FOG IN THE LOWER SOUTH PLATTE RIVER VALLEY HAS
DISSIPATED. SUNNY SKIES ARE EXPECTED FOR THE REST OF THE DAY WITH
ONLY A FEW WISPY CIRRUS. TEMPERATURES ON TRACK TO REACH THE LOWER
50S ON THE PLAINS WITH SLIGHTLY COOLER READINGS OVER THE SNOW
COVERED NORTHEAST CORNER.
GIVEN THE WIDESPREAD HARD FREEZE LAST NIGHT...WE WILL NO LONGER
ISSUE FREEZE WARNINGS AS THE EFFECTIVE GROWING SEASON HAS COME TO
AN END.
&&
.AVIATION...NEARLY CLOUD FREE SKIES EXPECTED THROUGH TONIGHT WITH
UNLIMITED VISIBILITY. WEAK AND FAIRLY NORMAL DIURNAL WIND PATTERNS
EXPECTED PER ONGOING TAFS.
&&
.PREV DISCUSSION... /ISSUED 333 AM MDT SUN OCT 7 2012/
SHORT TERM...NNW FLOW ALOFT WILL BE OVER THE AREA THRU TONIGHT
WITH DRY CONDITIONS EXPECTED. MAIN CONCERN FOR THIS MORNING WILL
BE FOG POTENTIAL OVER NERN CO. SO FAR THE ONLY PLACE WITH FOG IS
OVER THE FAR NERN CORNER WHERE SKIES HAVE BEEN CLEAR OVERNIGHT.
CLOSER TO THE FRONT RANGE LOW LVL CLOUDS HAVE REMAINED IN PLACE
BUT HAVE BEEN SLOWLY DIMINISHING THE LAST FEW HOURS. AT THIS TIME
WILL KEEP AREAS OF FOG OVER THE PLAINS WHERE SKIES HAVE BEEN
GENERALLY CLEAR AND ONLY MENTION PATCHY FOG CLOSER TO THE
FOOTHILLS. AS FAS AS AFTN HIGHS WILL KEEP HIGHS IN THE LOWER TO
MID 50S ACROSS NERN CO FOR THIS AFTN. FOR TONIGHT SHOULD SEE
MAINLY CLEAR SKIES. MAY SEE SOME GUSTY WINDS IN THE MTNS AND
HIGHER FOOTHILLS LATE TONIGHT AS A WK MTN WAVE DEVELOPS.
LONG TERM...NORTHERN COLORADO WILL BE UNDER A MODERATE NORTHWEST
FLOW PATTERN THROUGH MIDWEEK WITH A DRY AIRMASS IN PLACE. THERE
WILL BE A WEAK TROF WHICH MOVES THROUGH THE NORTHERN PLAINS STATES
ON TUESDAY. THERE WILL BE AN ASSOCIATED COLD FRONT WHICH WILL COOL
TEMPERATURES ACROSS NORTHEAST COLORADO ON TUESDAY AS LOW LEVEL
INVERSIONS REMAIN IN PLACE. LATEST NAM BRINGS IN SOME LOW LEVEL
MOISTURE AND POTENTIAL STRATUS OVER THE PLAINS WHILE THE GFS AND
EUROPEAN ARE DRY. APPEARS MOST OF THE MOISTURE WITH THIS SYSTEM WILL
BE TOO FAR NORTH AND EAST OF COLORADO FOR ANY BENEFIT. WARMER
AGAIN ON WEDNESDAY AS HEIGHTS BUILD AS TEMPERATURES RETURN CLOSE
TO CLIMATE NORMALS FOR THIS TIME OF YEAR.
THE NEXT WEATHER MAKER WILL BE CLOSED LOW WHICH WILL BE OFF THE
SOUTHERN CALIFORNIA COAST BY THURSDAY WHICH WILL RESULT IN SOME
DOWNSTREAM RIDGING ACROSS COLORADO. THE FLOW ALOFT WILL SHIFT WEST
TO SOUTHWEST THURSDAY AND FRIDAY AS MOISTURE VALUES SLOWLY
ELEVATE. THE LOW IS PROGGED TO EJECT INTO COLORADO SOMETIME IN THE
FRIDAY THROUGH SATURDAY TIME FRAME DEPENDING ON WHICH MODEL.
SOLUTIONS VARY FROM THE SLOWER GFS SOLUTION TO THE FASTEST
EUROPEAN. SEEMS LIKE THERE IS EVEN MORE VARIATION IN THE SOLUTIONS
TODAY COMPARED TO YESTERDAY SO FORECAST CONFIDENCE NOT VERY HIGH.
TYPICALLY THESE SYSTEMS END UP BEING SLOWER THAN FORECAST. NO
MAJOR CHANGES PLANNED IN UPCOMING FORECAST PACKAGE FOR THE LONG
TERM AND WILL KEEP LOW POPS FOR THE ENTIRE AREA ON FRIDAY AND SATURDAY.
AVIATION...SO FAR THE HRRR AND THE RAP ARE NOT REAL EXCITED ABOUT
LIFR CONDITIONS IN THE 10Z-15Z TIME PERIOD AS BOTH KEEP LIFR
CONDITIONS TO THE NE OF THE AIRPORT. RAP STILL SHOWS A WEAK DENVER
CYCLONE NR THE AIRPORT BY 12Z SO AM TEMPTED TO LEAVE IN A BRIEF 3
HR WINDOW FM 12Z-15Z FOR SOME LOWER CEILINGS AND FOG FOR NOW AS
SKIES HAVE STARTED TO CLEAR. FOR THIS AFTN AND TONIGHT EXPECT VFR
CONDITIONS. WINDS WILL BE LIGHT AND VARIABLE THIS MORNING AND THEN
BECOME LIGHT NLY BY AFTN. FOR TONIGHT WINDS SHOULD BECOME
DRAINAGE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....ENTREKIN
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS MIAMI FL
921 AM EDT SUN OCT 7 2012
.UPDATE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE ATLANTIC
WATERS MAKING THEIR WAY ONSHORE THE SOUTHEAST FLORIDA COAST THIS
MORNING. WATERSPOUTS ARE POSSIBLE WITH SOME OF THESE
SHOWERS...SIMILAR TO YESTERDAY...AND WILL CONTINUE TO MENTION THIS
IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY.
MORNING SOUNDING FROM MIAMI SHOWS LITTLE CHANGE FROM YESTERDAY
WITH LOTS OF MOISTURE. THE SOUNDING FROM KEY WEST, HOWEVER, SHOWS A
SUBTLE DRIER LAYER FROM 850 MB TO 700 MB. SHORT RANGE MODELS
INCLUDING THE HRRR AREN`T SHOWING AS MUCH CONVECTION OVER THE
SOUTHERN PENINSULA THIS AFTERNOON COMPARED TO PAST COUPLE OF DAYS.
GLOBAL MODELS (GFS AND ECMWF) SHOW A WEAK MID-LEVEL SHORTWAVE
PASSING THROUGH SOUTH FLORIDA THIS MORNING (POTENTIALLY
CONTRIBUTING TO INCREASED ATLANTIC AND COASTAL CONVECTION THIS MORNING) AND
OVER THE ATLANTIC THIS AFTERNOON. THE DRIER AIR OBSERVED AT KEY
WEST MAY BE AN INDICATION OF SUBSIDENCE BEHIND THE SHORTWAVE AND
MODELS COULD BE PICKING UP ON THIS.
HAVING SAID ALL THIS, STILL EXPECT AT LEAST SCATTERED
SHOWERS/TSTMS OVER INTERIOR AREAS THIS AFTERNOON WITH SLOW
MOVEMENT OF CELLS LEADING TO LOCALLY HIGH RAINFALL AMOUNTS.
HOWEVER, WOULD NOT BE SURPRISED TO SEE LESS ACTIVITY THIS
AFTERNOON AS PER MODEL TRENDS INDICATED ABOVE.
MOLLEDA
&&
.PREV DISCUSSION... /ISSUED 727 AM EDT SUN OCT 7 2012/
AVIATION...
CIRRUS CLOUDS COVER MUCH OF THE REGION THIS MORNING...FROM
CONVECTION LAST NIGHT. LIGHT WINDS THIS MORNING WILL BECOME
EASTERLY WITH DIURNAL HEATING LATER TODAY. A WEST COAST SEA BREEZE
IS ALSO EXPECTED TO BECOME ESTABLISHED BY EARLY AFTERNOON. THIS
WILL SET THE STAGE AGAIN FOR SCT TSRAS ACROSS MUCH OF THE SOUTH
FLORIDA AREA...ESPECIALLY ACROSS INTERIOR AREAS. ACTIVITY SHOULD
DIMINISH SHORTLY AFTER NIGHTFALL.
PREV DISCUSSION... /ISSUED 255 AM EDT SUN OCT 7 2012/
SHORT TERM (TODAY-TUESDAY)...
THE LATEST SURFACE ANALYSIS EARLIER THIS MORNING SHOWED A COLD FRONT
EXTENDING SOUTHWEST FROM THE CAROLINAS TO THE CENTRAL GULF COAST
STATES AND WEAK HIGH PRESSURE CENTERED NORTHEAST OF THE LOCAL AREA
OFF THE NERN FLORIDA COAST ACROSS THE WESTERN ATLANTIC. MOIST
EASTERLY LOW-LEVEL FLOW SOUTH OF THIS HIGH WILL PERSIST OVER THE
AREA INTO MONDAY AS THE COLD FRONT GRADUALLY CONTINUES SOUTHEASTWARD
INTO THE STATE AND HIGH PRESSURE BUILDS ACROSS THE REGION IN ITS
WAKE. RECENTLY ANIMATED WATER VAPOR LOOP SHOWED BROAD CYCLONIC FLOW
ACROSS THE MID-SECTION AND EASTERN HALF OF THE COUNTRY CHARACTERIZED
WITH A FAIRLY STRONG SHORTWAVE TROUGH DIGGING SOUTHEAST AND EAST
ACROSS THE PLAINS. MID TO UPPER SW FLOW ALONG WITH PLENTY OF
MID/UPPER MOISTURE AHEAD OF THIS UPPER TROUGH CONTINUES TO STREAM
OVERHEAD. MODEL SOUNDING PROFILES REMAIN FAIRLY WET ACROSS THE
LOCAL AREA THROUGH THE BULK OF THIS SHORT-TERM PERIOD WITH PW`S
REMAINING AROUND THE 2" INCH MARK. ONE MAIN DIFFERENCE OR TREND
NOTED FROM RUN TO RUN WITHIN THE MODELS HAS BEEN THE DECREASE IN
SOUTHWARD PROGRESSION OF THE FRONTAL BOUNDARY INTO OUR LOCAL AREA
OVER THE NEXT COUPLE OF DAYS. THE LATEST MODEL CYCLE INDICATES
THE BOUNDARY STALLING OVER CENTRAL FLORIDA SOMETIME BETWEEN MONDAY
EVENING AND TUESDAY...WHEREAS BEFORE...ALL INDICATIONS INDICATED
THE BOUNDARY PROGRESSING INTO THE AREA WITH DRIER AIR FILTERING IN
BEHIND IT. THIS WILL RESULT IN THE RAIN CHANCES REMAINING IN THE
FORECAST THROUGH THIS PERIOD WITH THE BEST POTENTIAL FOR THE DRIER
AIR LATER THROUGH THE MID/LATTER HALF OF THE WEEK. THE LATEST WRF
MODEL REFLECTIVITIES SUPPORT THIS AND GENERALLY INDICATE THE BULK
OF THE ACTIVITY SETTING UP OVER THE INTERIOR AND GULF COAST
REGIONS THROUGH THE AFTERNOON AND EVENING PERIODS.
HOWEVER...SIMILAR TO YESTERDAY...SCATTERED SHOWERS AND STORMS
DEVELOPING AND SPREADING WEST ACROSS THE EASTERN HALF OF THE AREA
WILL REMAIN POSSIBLE THROUGH THE FIRST HALF OF THE DAY TODAY. THE
LATEST MODEL GUIDANCE INDICATES AN ADDITIONAL HALF OF AN INCH TO
AN INCH ACROSS THE WESTERN HALF OF THE AREA OVER THE UPCOMING FEW
DAYS...WHICH LINES UP WELL WITH THE LATEST HPC GUIDANCE. LOCALLY
HIGHER AMOUNTS WILL REMAIN POSSIBLE WHERE THE ACTIVITY BECOMES
CONCENTRATED THROUGH THIS TIME. AS A RESULT...THE MAIN CONCERNS
WILL BE THE POTENTIAL FOR LOCALIZED FLOODING AND WET
MICROBURSTS/GUSTY WINDS IN AND AROUND THE HEAVIER ACTIVITY OR
STRONG STORMS THAT DEVELOP.
LONG TERM...(TUESDAY NIGHT-SATURDAY)
THE LATEST GFS/GFS ENSEMBLE AND ECMWF REMAIN IN DECENT AGREEMENT ON
THE LARGE SCALE THROUGH THE MID-WEEK PERIOD AND GENERALLY KEEP THE
BROAD CYCLONE FLOW IN PLACE ACROSS THE EASTERN STATES. HOWEVER...ALL
CONTINUE TO SUGGEST MUCH DRIER DEEP LAYER AIR SPREADING SOUTH AS
THE PREVIOUSLY DISCUSSED FRONTAL BOUNDARY STALLS AND DIMINISHES
AND THE MEAN UPPER TROUGH AXIS SHIFTS EWD. THIS DRY AIR WILL
TRANSLATE TO A SLIGHT DECREASE IN DEWPOINTS...POSSIBLY INTO THE
UPPER 60S INLAND AND NORTH AROUND THE LAKE REGION. WILL REFLECT
THIS WITH DECREASING RAINFALL CHANCES THROUGH THIS TIME ACROSS THE
AREA. NO NOTABLE CHANGES REGARDING THE DAILY HIGH AND LOW
TEMPERATURES THROUGH THIS EXTENDED PERIOD.
MARINE...
LIGHT EASTERLY FLOW WILL PERSIST INTO THE UPCOMING WEEK AS A
WEAKENING FRONTAL BOUNDARY APPROACHES FROM THE NORTH AND NORTHWEST.
SCATTERED SHOWERS AND STORMS WILL REMAIN IN THE FORECAST THROUGH
THIS TIME. DRIER AIR WITH LIGHT TO MODERATE NORTHEAST WINDS WILL
BECOME A POSSIBILITY THROUGH THE MIDDLE PART OF THE UPCOMING WEEK.
SEAS WILL RESPOND AND INCREASE INTO THE 3 TO 5 FOOT RANGE ACROSS THE
ATLANTIC WATERS.
FIRE WEATHER...
DESPITE THE DRIER AIR PROGGED TO FILTER INTO THE AREA FROM NORTH TO
SOUTH NEXT WEEK...RELATIVE HUMIDITIES ARE FORECAST TO REMAIN WELL
ABOVE CRITICAL LEVELS WITH NO RED FLAG CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 77 88 78 / 40 30 40 30
FORT LAUDERDALE 85 79 88 77 / 40 30 40 30
MIAMI 88 78 89 77 / 40 30 40 30
NAPLES 88 75 90 75 / 40 30 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
601 AM MDT SUN OCT 7 2012
.UPDATE...
ISSUED AT 558 AM MDT SUN OCT 7 2012
UPDATED THE FORECAST TO CANCELL THE SOUTHWEST PORTION OF THE
FREEZE WARNING.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 243 AM MDT SUN OCT 7 2012
FORECAST CONCERNS WILL BE HOW MUCH THE TEMPERATURES MODERATE THROUGH
MONDAY BEFORE THE NEXT COLD FRONT MOVES IN TO COOL OFF TUESDAY.
SATELLITE CONTINUING TO SHOW AN AMPLIFIED PATTERN FROM THE PACIFIC
INTO EASTERN NORTH AMERICA. FLOW DOMINATED BY A BLOCK ALONG THE WEST
COAST AND A TROUGH OVER THE CENTRAL AND EASTERN PORTION OF THE
COUNTRY. COLD AND MOIST AIR MASS REMAINS OVER THE CENTRAL PORTION OF
THE COUNTRY.
MODELS INITIALIZED FINE AT THE JET AND MID LEVELS. NAM WAS CATCHING
THE SURFACE RIDGING AND WIND FIELD IN OUR AREA THE BEST. NAM AND
RUC APPEAR TO BE CATCHING THE STRATUS FIELD THE BEST. THE GFS AND
CANADIAN WERE DOING A LITTLE BETTER THAN THE REST ON THE LOW LEVEL
THERMAL FIELD.
TODAY/TONIGHT...STRATUS KEEPS EDGING EVER SO SLOWLY SOUTHWEST. NOT
SURE HOW MUCH FURTHER IT WILL GO. LOCATIONS ON THE EDGE OF THIS
CLOUD FIELD ARE NOT THAT FAR AWAY FROM REACHING THE NEEDED
TEMPERATURES FOR THE FREEZE WARNING TO VERIFY. AT THIS TIME I WILL
LET THE FREEZE WARNING CONTINUE BUT FEELING IS THAT THE FAR
SOUTHWEST AND WESTERN PORTIONS WILL NOT MAKE IT.
SOME FOG HAS DEVELOPED. THE 00Z NAM DRASTICALLY OVERDID THE FOG. THE
06Z NAM IS NOW MORE REALISTIC AND DEVELOPING FOG IN AREAS THAT HAVE
CLEARED. THE HRRR AND RUC DO NOT AGREE WITH EACH OTHER BUT TEND TO
FAVOR THE WEST AND MORE IN LOCATIONS THAT HAVE THE STRATUS. AT THIS
TIME WILL ADD FOG PER THE LATEST NAM WHICH DOES MAKE SENSE.
WEAK LEFT FRONT QUADRANT OF THE UPPER JET AND A RATHER STRONG
SHORTWAVE MOVES THROUGH DURING THE LATE MORNING AND AFTERNOON. WILL
HAVE TO KEEP WATCHING BUT THESE FEATURES LOOK TO SPREAD SOME HIGHER
LEVEL CLOUD COVER ACROSS THE AREA. TEMPERATURES TODAY WILL BE
AFFECTED BY HOW FAST THE STRATUS LEAVES WHICH LOOKS TO BE BY LATE
MORNING. HAVE AN AREA IN THE NORTHERN PORTION OF THE AREA THAT HAD
SIX PLUS INCHES OF SNOW YESTERDAY. AREAS DOWNSTREAM OF SNOW FIELD
COULD BE AFFECT. WITH WARM GROUND WOULD IMAGINE THAT SNOW WOULD MELT
A LITTLE FASTER THAN NORMAL. WILL DEFINITELY HAVE AN AFFECT TODAY ON
THE TEMPERATURES AND MADE THAT AREA COOLER THAN SURROUNDING
LOCATIONS. IF STRATUS HOLDS ON LONGER ALL THE TEMPERATURES MAY END
UP BEING TOO WARM.
MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT OF UPPER JET MOVES ACROSS
AT THE BEGINNING OF THE DAY. IT LOOKS LIKE IT WILL SPREAD SOME CLOUDS
ACROSS THE AREA. MODELS SHOW GOOD DOWNSLOPE WINDS THROUGH MOST OF
THE DAY UNTIL THEY BECOME LIGHTER AND MORE IN THE MIDDLE OF THE
AFTERNOON. SO WILL TREND TOWARD THE WARMER GUIDANCE.
THERE IS SOME MODEL DIFFERENCES IN HOW TO HANDLE THE SYSTEM DIGGING
OUT OF CENTRAL CANADA. THE NAM IS FASTER AND DEEPER. GFS IS NOT AS
DEEP. OTHER MODELS ARE FAIRLY DEEP...SLOWER AND ARE A LITTLE
FURTHER SOUTHWEST. AS A CONSEQUENCE THE NAM IS THE FASTEST TO PUSH
THE FRONT THROUGH AND THROUGH MOST OF THE AREA BY 12Z. IT IS ALWAYS
POSSIBLE IN THIS SCENARIO THAT FRONTS WILL COME IN FASTER BUT AM
LEARY OF THE NAM A LITTLE. SO WENT IN THE MIDDLE OF THE SOLUTIONS.
TUESDAY/TUESDAY NIGHT...ABOVE MENTIONED JET MOVES ACROSS DURING THE
MORNING BUT MODELS INDICATE VERY LITTLE CLOUD COVER WILL BE GENERATED
BY THIS FEATURE. ALL THE MODELS HAVE THE FRONT THROUGH THE FORECAST
AREA BY 18Z. THERE IS A LITTLE BIT OF SPREAD IN HOW MUCH COOLING
TAKES PLACE. THE NAM IS THE WARMEST BUT NOT BY MUCH AND THE ECMWF
THE COOLEST. THE OTHER MODELS CLUSTER IN THE MIDDLE. AT THIS TIME
WILL GO WITH A COMPROMISE OF TEMPERATURES WHICH DOES LOWER THE
MAXES A LITTLE.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 243 AM MDT SUN OCT 7 2012
THE UPPER PATTERN DURING THIS PERIOD WILL TRANSITION FROM FAST
NORTHWEST FLOW ALOFT ON WED TO UPPER RIDGING THU-EARLY FRI TO STRONG
SOUTHWEST FLOW LATER FRI-SAT AS THE UPPER LOW APPROACHING CALIFORNIA
EJECTS NORTHEAST ACROSS THE CENTRAL HIGH PLAINS. NUMERICAL GUIDANCE
HAS VASTLY DIFFERING SOLUTIONS ON WHERE AND HOW FAST THE UPPER LOW
LIFTS OUT OF THE SOUTHWEST U.S. WHICH IS ULTIMATELY TIED TO THE
LOCATION AND INTENSITY OF THE NEXT UPSTREAM TROUGH. THE EC IS NOW
CONSIDERABLY FASTER AND MUCH FURTHER NORTH COMPARED TO GFS. SATURDAY
MORNING THE EC HAS THE UPPER LOW OVER CENTRAL NEBRASKA WHILE GFS
HOLDS IT BACK OVER THE FOUR CORNERS. THE GEM WAS PRETTY MUCH IN STEP
WITH THE GFS THRU 144 HRS /FRI/. NEEDLESS TO SAY...CONFIDENCE IS
LOW IN THE TIMING AND AMOUNT OF ASSOCIATED PRECIP IN THE FRI-SAT
TIME FRAME. EXPERIENCE WOULD FAVOR A SLOWER /GFS/ MOVEMENT BUT A
BLEND IS PROBABLY APPROPRIATE AT THIS POINT. WHICHEVER MODEL
VERIFIES... IF EITHER ONE DOES... WILL ALSO MAKE A BIG DIFFERENCE IN
THE POTENTIAL TO GET DRY SLOTTED. WHATEVER THE OUTCOME...LOOKS LIKE
A RETURN TO MORE TYPICAL OCTOBER TEMPERATURES GIVEN THE UPPER
PATTERN CHANGE DURING PERIOD.
AT THE SURFACE...ONE LAST CANADIAN HIGH PRESSURE AREA WILL DROP
SOUTHEAST INTO THE AREA THURSDAY BEFORE UPPER RIDGING AND SOUTHWEST
FLOW ALOFT TAKE OVER. THE EC IS A LITTLE SLOWER WITH THE COLD
FRONTAL PASSAGE COMPARED TO GFS/GEM WHICH COULD MAKE THURSDAY MAX
TEMPS A LITTLE TRICKY. CURRENT FORECAST HAS MAX TEMPERATURES IN THE
UPPER 60S/LOWER 70S BEFORE FRONTAL PASSAGE.
THE NEXT SHOT AT PRECIP LOOKS TO BE TOWARD THE END OF THIS FORECAST
PERIOD WITH TIMING DEPENDING ON SPEED AT WHICH UPPER LOW EJECTS
NORTHEAST. THE EC BRINGS IN POTENTIAL FOR SHOWERS AND THUNDERSTORMS
EARLY FRIDAY MORNING WHILE GFS TIMING IS FRIDAY NIGHT INTO SATURDAY.
CURRENT FORECAST IS A BLEND OF NUMERICAL GUIDANCE AND BRINGS IN
CHANCE POPS STARTING FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 558 AM MDT SUN OCT 7 2012
KGLD WILL HAVE MVFR CONDITIONS UNTIL 18Z THEN VFR FOR THE
REMAINDER OF THE PERIOD. KMCK WILL HAVE LIFR CONDITIONS BEFORE
GRADUALLY IMPROVING BY 18Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FREEZE WARNING UNTIL 10 AM CDT THIS MORNING FOR KSZ001>004-
014>016-028-029.
CO...FREEZE WARNING UNTIL 9 AM MDT THIS MORNING FOR COZ090.
NE...FREEZE WARNING UNTIL 9 AM MDT /10 AM CDT/ THIS MORNING FOR
NEZ079>081.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM...DLF
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
953 AM EDT SUN OCT 7 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE REGION EARLY TODAY. LOW
PRESSURE WILL TRACK EAST OF THE GULF OF MAINE TONIGHT INTO
MONDAY MORNING. HIGH PRESSURE WILL RIDGE ACROSS THE REGION
ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
950 AM UPDATE...ONLY MINOR ADJUSTMENTS NEEDED FOR THIS UPDATE.
INCREASED POPS JUST A BIT LATE THIS AFTERNOON AS PER HRRR MODEL,
WHICH IS SHOWING ISOLATED SHOWERS COMING INTO FAR SOUTHERN
PORTIONS OF THE AREA TOWARD 4-5 PM. ALSO TWEAKED SKY COVER TO
MATCH CURRENT SATELLITE. NO OTHER CHANGES NEEDED.
PREVIOUS DISCUSSION...
MAIN CHALLENGE WILL BE OF COURSE THE TEMPERATURES AND QPF.
WEAK HIGH PRES RIDGING WILL QUICKLY GIVE WAY TO THE NEXT SYSTEM
APCHG FROM MID ATLC REGION LATER THIS AFTERNOON INTO TONIGHT. CLOUDS
WILL BE BACK ON THE INCREASE AFTER SOME PARTIAL CLEARING IN ADVANCE
OF THE WEAK LOW APCHG FROM THE S TODAY. TEMPERATURES WILL BE
COOLER THAN THEY HAVE BEEN THE LAST FEW DAYS W/READINGS BACK TO
AOB NORMAL LEVELS FOR EARLY OCTOBER. DECIDED ON A BLEND OF THE
NAM12 AND GMOS FOR TODAY/S MAXES WHICH SHOWS LOW TO MID 50S NORTH
AND MID TO TO UPPER 50S CENTRAL AND DOWNEAST.
THE CHALLENGE FOR TONIGHT IS HOW FAR NORTH WILL PRECIP GET AND
HOW COLD WILL TEMPERATURES BE. ALL THE SHORT RANGE GUIDANCE
INCLUDING THE CANADIAN GEM/NAM AND GFS SHOW PRECIP SHIELD EDGING
ITS WAY INTO COASTAL AND SWRN AREAS BY EARLY EVENING. THE PRECIP
IS EXPECTED TO SPREAD NNE OVERNIGHT AS LOW PRES MOVES NE ACROSS
THE GULF OF MAINE. ATTM, THE BEST LIFT APPEARS TO BE SITUATED
ACROSS THE DOWNEAST AND EASTERN SECTIONS AND THIS IS WHERE THE
HIGHER QPF VALUES WERE PLACED(.25-.30"). THE 00Z NAM AND GFS BOTH
POINT TO A VIGOROUS VORTICITY MAX W/DECENT ADVECTION TO MOVE
ACROSS THE STATE OVERNIGHT INTO EARLY MONDAY MORNING. THIS WILL
AID IN PROVIDING ADDITION LIFT FOR PRECIP. THE 00Z ECWMF SHOWS
THIS FEATURE AS WELL AS DOES THE LATEST WV SATL IMAGERY W/THE VORT
MAX OVER MISSOURI. THEREFORE, SQUEEZED POPS DOWN SOME W/40-50%
ACROSS THE FAR N AND NW AND LIKELY TO CATEGORICAL(60-90%) FOR THE
CENTRAL AND DOWNEAST REGION INCLUDING THE COAST. PRECIP WILL BE IN
THE FORM OF RAIN FOR ALL AREAS AS TEMPERATURES WILL REMAIN ABOVE
32-33F. THE EXCEPTION TO THIS WILL BE THE FAR W AND NW AREAS AS
SOME SNOW COULD MIX IN W/THE RAIN BY 09Z MONDAY AS TEMPERATURES
ARE EXPECTED TO FALL BACK INTO THE LOWER 30S(33-34F). THE 00Z
ECMWF HAS 925MB TEMPERATURES FALLING TO NEAR 0C IN THESE AREAS BY
EARLY MONDAY MORNING. 07Z SFC ANALYSIS SHOWED TEMPERATURES IN THE
LOW 30S ACROSS WESTERN QUEBEC AND OTTAWA. IF THE CHANGEOVER
OCCURS, IT WILL BE BRIEF AS THE PRECIP WILL SHUT OFF QUICKLY AS
THE LOW EXITS ACROSS NOVA SCOTIA AND HIGH PRES BEGINS TO RIDGE
FROM THE S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE START OF THE SHORT TERM FINDS THE MODELS IN GOOD AGREEMENT. A
LOW OVER ERN NOVA SCOTIA AND ASSOCIATED FRONTAL SYSTEM EXITING THE
AREA TO THE EAST...A HIGH PRESSURE RIDGE DOMINATING THE WEATHER
ACROSS MUCH OF THE MIDDLE AND ERN PORTIONS OF THE UNITED STATES. A
MAJOR SHORT WAVE TROUGH EXTENDING SOUTH ACROSS LAKE MICHIGAN INTO
NRN LA. A NEW LOW MVG SE OUT OF WRN CANADA INTO THE NRN PLAINS.
MON EVNG THE THE LOW OVR NOVA SCOTIA MOVES EAST INTO THE
MARITIMES. THE HIGH PRESSURE RIDGE EXTENDS ACROSS MAINE. THE NEW
LOW MOVES SE INTO LAKE SUPERIOR...AN ASSOCIATED UPPER LOW STACKED
TO THE NW OF THE SFC LOW. THE SHORT WAVE TROUGH MOVES EAST TO THE
APPALACHIANS. TUES MRNG THE LOW OVR LAKE SUPERIOR MOVES NE TO THE
NRN TIP OF SUPERIOR...THE UPPER LOW CONTINUES TO SUPPORT THE SFC
LOW. BY THE END OF THE PERIOD. THE HIGH PRESSURE RIDGE REMAINS
OVER MAINE. THE LOW OVR NRN LAKE SUPERIOR MOVES NE INTO SRN JAMES
BAY...DEEPENS AT THIS POINT THE UPPER LOW HAS BECOME VERTICALLY
STACKED WITH THE SFC SYSTEM.
LOADED MATCH GUIDANCE FOR MAX/MIN. BLENDED THE GFS/NAM HRLY
TEMP/DP. BLENDED THE GFS/NAM/OFFICIAL FOR WNDS/SKY/POP.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AT THE START OF THE LONG TERM THE MODELS CONTINUE TO BE IN GOOD
AGREEMENT. A HIGH PRESSURE RIDGE EXTENDING FROM ERN QUEBEC TO THE
GULF OF MEXICO WILL DOMINATE THE WEATHER FOR THE LOCAL AREA EARLY
IN THE PERIOD. A DEEPENING LOW OVER SRN JAMES BAY...WITH AN
ASSOCIATED FRONT WRAPPED AROUND THE LOW THEN EXTENDING SOUTH
THROUGH WRN LAKE HURON...LAKE MICHIGAN...TO NWRN IL. BY WED EVNG
THE FRONT MOVES EAST INTO WRN MAINE...THE ASSOCIATED LOW CONTINUES
TO MOVE NE INTO NRN QUEBEC. THE ASSOCIATED SHORT WAVE EXTENDS
THROUGH THE ERN GREAT LAKES TO SRN GA. A NEW LOW MOVES INTO THE
NRN PLAINS FROM NW CANADA. THURS MRNG THE FRONT MOVES THROUGH
MAINE...HIGHER PRESSURE STARTS TO BUILD INTO SW ME. THE NEW LOW
MOVES EAST TO LAKE SUPERIOR. THE UPPER LVLS WILL BECOME MORE
ZONAL. SYSTEMS WILL TRANSIT QUICKLY ACROSS THE NRN US...BY THURS
EVNG THE NEW LOW TRACK ACROSS THE GREAT LAKE TO SRN QUEBEC. BY
EARLY FRI MRNG THE LOW WILL MOVE INTO NW ME. BY FRI MRNG (THE GFS)
THE LOW WILL BE INTO NRN NEW BRUNSWICK AND HIGHER PRESSURE WILL
BEGIN TO BUILD INTO ME. (THE ECMWF) THE LOW WILL MOVE TO CNTRL
QUEBEC...TRAILING A FRONT ACROSS NW ME. FRI EVNG THE GFS MOVES THE
SYSTEM WELL EAST OF MAINE...BEGINS TO BUILD HIGHER PRESSURE. THE
ECMWF MOVES THE LOW AND ASSOCIATED FRONT EAST OF MAINE. HIGHER
PRESSURE WILL DOMINATE THROUGH SAT. BY SAT EVNG THERE WILL BE A
NEW LOW OVR WRN KS THIS LOW WILL DEEPEN RAPIDLY...AND MOVE NE TO
NRN IA...ITS ASSOCIATED WARM FRONT WILL EXTEND EAST INTO SRN NH.
BY THE END OF THE PERIOD THE LOW WILL BE OVER SRN QUEBEC. THE
ASSOCIATED WARM FRONT EXTENDING THROUGH MAINE.
LOADED GMOS... ADJUSTED SKY/POPS WITH GFS FOR WED-SAT. GMOS
GUIDANCE TO HIGH GFS. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL
WATERS. ADDED 20 PERCENT FOR WNDS OVR THE WATERS...15 PERCENT OVR
LAND.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR LOOKS TO BE THE GOING RATE INTO EARLY EVENING AND
THEN MVFR CONDITIONS POSSIBLE ACROSS KBGR AND KBHB. VFR IS
EXPECTED TO HOLD ACROSS THE NORTHERN TERMINALS.
SHORT TERM: MVFR CONDITIONS AT ALL SITES RAPIDLY IMPROVING AS
FRONTAL SYSTEM MOVES EAST OF THE AREA. VFR CONDITIONS AT ALL SITES
BY MID MORNING MONDAY. VFR CONDITIONS WILL CONTINUE INTO
TUESDAY...ISOLATED SHOWER/THUNDERSTORMS FOR BGR...BHB TUESDAY
AFTERNOON...MVFR TO IFR CONDITIONS DURING PCPN. CONDITIONS WILL
FALL TO MVFR ON WEDNESDAY SOUTH TO NORTH...BHB...BGR IN THE
MORNING THE OTHER SITES DURING THE AFTERNOON AS A LOW PRESSURE
CENTER TRANSITS THROUGH THE GULF OF MAINE. IFR CONDITIONS WILL
CONTINUE THROUGH THE END OF THE PERIOD.
&&
.MARINE...
NEAR TERM: DROPPED THE SCA AS WINDS/SEAS ARE BELOW CRITERIA. NO
HEADLINES FOR THIS TERM. USED A BLEND OF THE NAM12 AND GFS FOR THE
WINDS WHICH SUPPORTS 10-15 KTS SUSTAINED BY TONIGHT. STAYED CLOSE
TO THE DAYCREW`S WAVE HEIGHTS OF 2-3 FT.
SHORT TERM: WINDS AND SEAS WILL REMAIN BELOW SCA THROUGH MID DAY
WEDNESDAY. SEAS WILL BEGIN TO BUILD AT WEDNESDAY EVENING AS A
FRONTAL SYSTEM MOVES INTO THE GULF OF MAINE WATERS. AN SCA MAYBE
REQUIRED WED THROUGH THURS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/NORTON
AREA FORECAST DISCUSSION
NWS CARIBOU ME
645 AM EDT SUN OCT 7 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE REGION EARLY TODAY. LOW
PRESSURE WILL TRACK EAST OF THE GULF OF MAINE TONIGHT INTO
MONDAY MORNING. HIGH PRESSURE WILL RIDGE ACROSS THE REGION
ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: ADJUSTED THE SKY CONDITIONS USING THE LATEST IR SATL
IMAGERY AND THE HRRR WHICH APPEARS TO BE DOING WELL. CLEARING WILL
GIVE WAY TO CLOUDS LATER THIS MORNING INTO THE AFTERNOON. ADJUSTED
THE HRLY TEMPS AS WELL UPWARD AS PREVIOUS THINKING WAS TOO COLD.
PULL THE FOG FOR THE REMAINDER OF THE MORNING.
PREVIOUS DISCUSSION...
MAIN CHALLENGE WILL BE OFF COURSE THE TEMPERATURES AND QPF.
WEAK HIGH PRES RIDGING WILL QUICKLY GIVE WAY TO THE NEXT SYSTEM
APCHG FROM MID ATLC REGION LATER THIS AFTERNOON INTO TONIGHT. CLOUDS
WILL BE BACK ON THE INCREASE AFTER SOME PARTIAL CLEARING IN ADVANCE
OF THE WEAK LOW APCHG FROM THE S TODAY. TEMPERATURES WILL BE
COOLER THAN THEY HAVE BEEN THE LAST FEW DAYS W/READINGS BACK TO
AOB NORMAL LEVELS FOR EARLY OCTOBER. DECIDED ON A BLEND OF THE
NAM12 AND GMOS FOR TODAY/S MAXES WHICH SHOWS LOW TO MID 50S NORTH
AND MID TO TO UPPER 50S CENTRAL AND DOWNEAST.
THE CHALLENGE FOR TONIGHT IS HOW FAR NORTH WILL PRECIP GET AND
HOW COLD WILL TEMPERATURES BE. ALL THE SHORT RANGE GUIDANCE
INCLUDING THE CANADIAN GEM/NAM AND GFS SHOW PRECIP SHIELD EDGING
ITS WAY INTO COASTAL AND SWRN AREAS BY EARLY EVENING. THE PRECIP
IS EXPECTED TO SPREAD NNE OVERNIGHT AS LOW PRES MOVES NE ACROSS
THE GULF OF MAINE. ATTM, THE BEST LIFT APPEARS TO BE SITUATED
ACROSS THE DOWNEAST AND EASTERN SECTIONS AND THIS IS WHERE THE
HIGHER QPF VALUES WERE PLACED(.25-.30"). THE 00Z NAM AND GFS BOTH
POINT TO A VIGOROUS VORTICITY MAX W/DECENT ADVECTION TO MOVE
ACROSS THE STATE OVERNIGHT INTO EARLY MONDAY MORNING. THIS WILL
AID IN PROVIDING ADDITION LIFT FOR PRECIP. THE 00Z ECWMF SHOWS
THIS FEATURE AS WELL AS DOES THE LATEST WV SATL IMAGERY W/THE VORT
MAX OVER MISSOURI. THEREFORE, SQUEEZED POPS DOWN SOME W/40-50%
ACROSS THE FAR N AND NW AND LIKELY TO CATEGORICAL(60-90%) FOR THE
CENTRAL AND DOWNEAST REGION INCLUDING THE COAST. PRECIP WILL BE IN
THE FORM OF RAIN FOR ALL AREAS AS TEMPERATURES WILL REMAIN ABOVE
32-33F. THE EXCEPTION TO THIS WILL BE THE FAR W AND NW AREAS AS
SOME SNOW COULD MIX IN W/THE RAIN BY 09Z MONDAY AS TEMPERATURES
ARE EXPECTED TO FALL BACK INTO THE LOWER 30S(33-34F). THE 00Z
ECMWF HAS 925MB TEMPERATURES FALLING TO NEAR 0C IN THESE AREAS BY
EARLY MONDAY MORNING. 07Z SFC ANALYSIS SHOWED TEMPERATURES IN THE
LOW 30S ACROSS WESTERN QUEBEC AND OTTAWA. IF THE CHANGEOVER
OCCURS, IT WILL BE BRIEF AS THE PRECIP WILL SHUT OFF QUICKLY AS
THE LOW EXITS ACROSS NOVA SCOTIA AND HIGH PRES BEGINS TO RIDGE
FROM THE S.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
THE START OF THE SHORT TERM FINDS THE MODELS IN GOOD AGREEMENT. A
LOW OVER ERN NOVA SCOTIA AND ASSOCIATED FRONTAL SYSTEM EXITING THE
AREA TO THE EAST...A HIGH PRESSURE RIDGE DOMINATING THE WEATHER
ACROSS MUCH OF THE MIDDLE AND ERN PORTIONS OF THE UNITED STATES. A
MAJOR SHORT WAVE TROUGH EXTENDING SOUTH ACROSS LAKE MICHIGAN INTO
NRN LA. A NEW LOW MVG SE OUT OF WRN CANADA INTO THE NRN PLAINS.
MON EVNG THE THE LOW OVR NOVA SCOTIA MOVES EAST INTO THE
MARITIMES. THE HIGH PRESSURE RIDGE EXTENDS ACROSS MAINE. THE NEW
LOW MOVES SE INTO LAKE SUPERIOR...AN ASSOCIATED UPPER LOW STACKED
TO THE NW OF THE SFC LOW. THE SHORT WAVE TROUGH MOVES EAST TO THE
APPALACHIANS. TUES MRNG THE LOW OVR LAKE SUPERIOR MOVES NE TO THE
NRN TIP OF SUPERIOR...THE UPPER LOW CONTINUES TO SUPPORT THE SFC
LOW. BY THE END OF THE PERIOD. THE HIGH PRESSURE RIDGE REMAINS
OVER MAINE. THE LOW OVR NRN LAKE SUPERIOR MOVES NE INTO SRN JAMES
BAY...DEEPENS AT THIS POINT THE UPPER LOW HAS BECOME VERTICALLY
STACKED WITH THE SFC SYSTEM.
LOADED MATCH GUIDANCE FOR MAX/MIN. BLENDED THE GFS/NAM HRLY
TEMP/DP. BLENDED THE GFS/NAM/OFFICIAL FOR WNDS/SKY/POP.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AT THE START OF THE LONG TERM THE MODELS CONTINUE TO BE IN GOOD
AGREEMENT. A HIGH PRESSURE RIDGE EXTENDING FROM ERN QUEBEC TO THE
GULF OF MEXICO WILL DOMINATE THE WEATHER FOR THE LOCAL AREA EARLY
IN THE PERIOD. A DEEPENING LOW OVER SRN JAMES BAY...WITH AN
ASSOCIATED FRONT WRAPPED AROUND THE LOW THEN EXTENDING SOUTH
THROUGH WRN LAKE HURON...LAKE MICHIGAN...TO NWRN IL. BY WED EVNG
THE FRONT MOVES EAST INTO WRN MAINE...THE ASSOCIATED LOW CONTINUES
TO MOVE NE INTO NRN QUEBEC. THE ASSOCIATED SHORT WAVE EXTENDS
THROUGH THE ERN GREAT LAKES TO SRN GA. A NEW LOW MOVES INTO THE
NRN PLAINS FROM NW CANADA. THURS MRNG THE FRONT MOVES THROUGH
MAINE...HIGHER PRESSURE STARTS TO BUILD INTO SW ME. THE NEW LOW
MOVES EAST TO LAKE SUPERIOR. THE UPPER LVLS WILL BECOME MORE
ZONAL. SYSTEMS WILL TRANSIT QUICKLY ACROSS THE NRN US...BY THURS
EVNG THE NEW LOW TRACK ACROSS THE GREAT LAKE TO SRN QUEBEC. BY
EARLY FRI MRNG THE LOW WILL MOVE INTO NW ME. BY FRI MRNG (THE GFS)
THE LOW WILL BE INTO NRN NEW BRUNSWICK AND HIGHER PRESSURE WILL
BEGIN TO BUILD INTO ME. (THE ECMWF) THE LOW WILL MOVE TO CNTRL
QUEBEC...TRAILING A FRONT ACROSS NW ME. FRI EVNG THE GFS MOVES THE
SYSTEM WELL EAST OF MAINE...BEGINS TO BUILD HIGHER PRESSURE. THE
ECMWF MOVES THE LOW AND ASSOCIATED FRONT EAST OF MAINE. HIGHER
PRESSURE WILL DOMINATE THROUGH SAT. BY SAT EVNG THERE WILL BE A
NEW LOW OVR WRN KS THIS LOW WILL DEEPEN RAPIDLY...AND MOVE NE TO
NRN IA...ITS ASSOCIATED WARM FRONT WILL EXTEND EAST INTO SRN NH.
BY THE END OF THE PERIOD THE LOW WILL BE OVER SRN QUEBEC. THE
ASSOCIATED WARM FRONT EXTENDING THROUGH MAINE.
LOADED GMOS... ADJUSTED SKY/POPS WITH GFS FOR WED-SAT. GMOS
GUIDANCE TO HIGH GFS. LOADED NAWAVE 4 FOR SEAS IN THE COASTAL
WATERS. ADDED 20 PERCENT FOR WNDS OVR THE WATERS...15 PERCENT OVR
LAND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: VFR LOOKS TO BE THE GOING RATE INTO EARLY EVENING AND
THEN MVFR CONDITIONS POSSIBLE ACROSS KBGR AND KBHB. VFR IS
EXPECTED TO HOLD ACROSS THE NORTHERN TERMINALS.
SHORT TERM: MVFR CONDITIONS AT ALL SITES RAPIDLY IMPROVING AS
FRONTAL SYSTEM MOVES EAST OF THE AREA. VFR CONDITIONS AT ALL SITES
BY MID MORNING MONDAY. VFR CONDITIONS WILL CONTINUE INTO
TUESDAY...ISOLATED SHOWER/THUNDERSTORMS FOR BGR...BHB TUESDAY
AFTERNOON...MVFR TO IFR CONDITIONS DURING PCPN. CONDITIONS WILL
FALL TO MVFR ON WEDNESDAY SOUTH TO NORTH...BHB...BGR IN THE
MORNING THE OTHER SITES DURING THE AFTERNOON AS A LOW PRESSURE
CENTER TRANSITS THROUGH THE GULF OF MAINE. IFR CONDITIONS WILL
CONTINUE THROUGH THE END OF THE PERIOD.
&&
.MARINE...
NEAR TERM: DROPPED THE SCA AS WINDS/SEAS ARE BELOW CRITERIA. NO
HEADLINES FOR THIS TERM. USED A BLEND OF THE NAM12 AND GFS FOR THE
WINDS WHICH SUPPORTS 10-15 KTS SUSTAINED BY TONIGHT. STAYED CLOSE
TO THE DAYCREW`S WAVE HEIGHTS OF 2-3 FT.
SHORT TERM: WINDS AND SEAS WILL REMAIN BELOW SCA THROUGH MID DAY
WEDNESDAY. SEAS WILL BEGIN TO BUILD AT WEDNESDAY EVENING AS A
FRONTAL SYSTEM MOVES INTO THE GULF OF MAINE WATERS. AN SCA MAYBE
REQUIRED WED THROUGH THURS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...HEWITT
MARINE...HEWITT/NORTON
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1151 AM EDT SUN OCT 7 2012
.SYNOPSIS...
A NORTHEASTBOUND COLD UPPER LEVEL TROUGH WILL PROVIDE SCATTERED
SHOWERS THIS AFTERNOON. THEN HIGH PRESSURE WILL FOLLOW WITH CLEARING SKIES
AND LIGHT WINDS TONIGHT...WHICH MEANS TEMPERATURES MAY DROP BELOW
FREEZING EARLY MONDAY MORNING...WITH AREAS OF FROST AND PATCHY
FOG. THE HIGH PRESSURE WILL PROVIDE DRY CONDITIONS THE REST OF
MONDAY AND TUESDAY BEFORE A CANADIAN COLD FRONT BRINGS SHOWERS
WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
CONCUR WITH RECENT RAP AND WRF-NMM MODEL OUTPUT THAT A COLD UPPER
LEVEL TROUGH WILL MOVE NORTHEASTWARD THROUGH THE UPPER OHIO VALLEY
THIS AFTERNOON WITH SCATTERED SHOWERS.
AS RECENT SREF MODEL OUTPUT AND NAM MODEL PROFILES CONTINUE TO
SHOW...HIGH PRESSURE WILL FOLLOW WITH CLEARING SKIES AND LIGHT
WINDS BY LATE TONIGHT.
THIS SCENARIO WILL BE IDEAL FOR STRONG NOCTURNAL RADIATIONAL
COOLING. HENCE WITH THIS AFTERNOONS HIGH TEMPERATURES RESTRICTED
BY THE COOL CLOUDY CONDITIONS...AS RECENT GFS LAMP SHOWS MOST
PLACES WILL STRUGGLE TO REACH 50...CONTINUE TO EXPECT LOW
TEMPERATURES EARLY MONDAY MORNING TO BE MAINLY IN THE 30 TO 35
RANGE...AS RECENT GFS AND NAM MOS INDICATE.
RECENT NAM MODEL PROFILES SHOW A PARTICULARLY STRONG YET SHALLOW SURFACE
TEMPERATURE INVERSION. SO WITH AFTERNOON SURFACE DEW POINTS IN THE
THE MID 30S...IT STILL APPEARS PLAUSIBLE FOG CAN DEVELOP LATE
TONIGHT...WITH THE RIVER VALLEYS MORE VULNERABLE THAN ELSEWHERE.
SO HAVE CONTINUED THE FREEZE WARNING WITH MENTION OF EARLY MORNING
AREAS OF FROST AND PATCHY RIVER VALLEY FOG.
HIGH PRESSURE SUBSIDENCE WILL ENSURE MOSTLY SUNNY CONDITIONS THE
REST OF DAYTIME MONDAY WITH AFTERNOON HIGH TEMPERATURES 5 TO 8
DEGREES COLDER THAN NORMAL AS SHOWN BY RECENT GFS AND NAM MOS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
RECENT SREF MODEL OUTPUT SHOWS HIGH PRESSURE WILL CONTINUE TO PROVIDE
DRY AND RELATIVELY CLOUD FREE CONDITIONS THROUGH DAYTIME TUESDAY.
THEN A COLD FRONT...WITH ORIGINS IN THE PLAINS OF CENTRAL
CANADA...WILL SWEEP THROUGH THE UPPER OHIO VALLEY WITH SHOWERS
WEDNESDAY.
REGARDING TEMPERATURES...LOWS MONDAY NIGHT CAN BE NEARLY AS COLD
THIS COMING NIGHT...SO ITS POSSIBLE THERE CAN BE PATCHES OF FROST.
HOWEVER...WILL NOT ADDRESS THIS SCENARIO UNTIL THE EXTENT OF
TONIGHTS FREEZE ON THE GROWING SEASON CAN BE ASSESSED.
PER RECENT GFS MOS AND SREF MEAN VALUES...HIGHS TUESDAY AND LOWS
TUESDAY NIGHT CAN BE NEAR NORMAL. WEDNESDAYS HIGHS WILL BE
RESTRICTED BY CLOUDS, SHOWERS, AND RENEWED COLD ADVECTION...AND SO
CAN BE MORE LIKE 5 TO 8 DEGREES COLDER THAN NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE THEN TAKES OVER ACROSS THE SOUTHEASTERN UNITED
STATES WEDNESDAY NIGHT IN ADVANCE OF A WEAK COLD FRONT MOVING
THROUGH ON FRIDAY. DOES NOT APPEAR TO BE MUCH MOISTURE WITH THE
FRONT ITSELF...BUT FEEL THAT SLIGHT CHANCE POPS ARE PRUDENT
CONSIDERING POSSIBLE LAKE INFLUENCE. HIGH PRESSURE THEN MOVES IN
ONCE AGAIN...DROPPING ACROSS THE GREAT LAKES.
LOTS OF UNCERTAINTY WITH LOW PRESSURE DEVELOPING IN THE PLAINS
FOR THE WEEKEND...BUT SHOULD BE ABLE TO SWING SOME CHANCE POPS
LATE SATURDAY.
TEMPERATURES WILL REMAIN BELOW NORMAL THROUGHOUT THE EXTENDED
PERIOD.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL PROVIDE VFR CONDITIONS EARLY WITH INCREASING MID
AND HIGH CLOUDS.
WITH AN UPPER LEVEL WAVE PASSING THROUGH DAYTIME SUNDAY...EXPECT A
RETURN OF LOWER VFR CIGS THROUGHOUT THE DAY. EXPECT LIGHT RAIN TO
DEVELOP BY MIDDAY SPREADING NORTHWARD IN THE AFTERNOON BUT EXPECT
VFR TO CONTINUE.
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL CLEAN OUT CIGS SUNDAY EVENING WITH LIGHT WINDS.
VFR CONDITIONS THROUGH MUCH OF THE OUTLOOK PERIOD. THE EXCEPTION
WILL BE WEDNESDAY...WHEN A COLD FRONT WILL BRING RESTRICTIONS IN
SHOWERS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR MDZ001.
OH...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...FREEZE WARNING FROM 2 AM TO 9 AM EDT MONDAY FOR WVZ001>004-012-
021>023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
720 AM EDT SUN OCT 7 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SUN OCT 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FULL LATITUDE UPR
TROF OVER ERN NAMERICA...WITH NW FLOW ALF OVER THE UPR GRT LKS. WITH
H85 TEMPS ARND -7C OVER LK SUP /VS WATER TEMPS RANGING FM 6-7C OVER
THE W TO 11-12C OVER THE E/...A WEAK SHRTWV MOVING THRU THE UPR
LKS...AND ADEQUATE LLVL MSTR PER THE 00Z APX RAOB...SOME LK EFFECT
-SHRA MIXED WITH SN CONTINUE OVER MAINLY THE E HALF OF THE LK WHERE
INSTABILITY REMAINS GREATEST. PERSISTENT CNVGC SHOWN BY WIND OBS
OVER THE E HALF OF THE LAKE ARE ALSO HELPING TO MAINTAIN THE
COVERAGE/INTENSITY OF THIS PCPN IN THAT AREA. OVER THE W...MORE ACYC
LLVL FLOW ASSOCIATED WITH SFC RDG EXTENDING FM HI CENTER IN THE
SCNTRL PLAINS TOWARD THE UPR MIDWEST...COOLER WATERS...AS WELL AS
SOMEWHAT DRIER LLVL AIR SHOWN ON THE 00Z INL RAOB ARE CONSPIRING TO
LIMIT THE ACTIVITY OVER THAT PART OF THE LAKE. ALTHOUGH DRIER AIR
OVER THE NRN PLAINS PER THE 00Z BISMARCK RAOB IS SHIFTING TO THE E
IN THE WLY FLOW ON THE NRN FLANK OF THE HI CENTER IN THE SCNTRL
PLAINS...THERE IS A GOOD DEAL OF MID/HI CLD EXTENDING FM ARND LK
WINNIPEG INTO THE NRN PLAINS ASSOCIATED WITH ISENTROPIC ASCENT ON
THE 290-295K SFCS /H7-575/.
TODAY...SHORT TERM MODELS ARE IN GOOD AGREEMENT SHOWING LARGER SCALE
FLOW OVER THE ENTIRE CWA SHIFTING TO THE W AS HI PRES OVER THE
SCNTRL PLAINS SHIFTS TOWARD THE OH RIVER VALLEY...WHICH SHOULD
WEAKEN THE LLVL CNVGC NOW PRESENT OVER THE E HALF AND ADVECT WARMER
H85 TEMPS/DRIER LLVL AIR TO THE W OVER THE CWA. THESE TRENDS WL TEND
TO STEADILY WEAKEN THE ONGOING LK EFFECT PCPN NOW IMPACTING MAINLY
THE E HALF OF THE CWA. THE ARRIVAL OF THE DRIER AIR WL ALSO RESULT
IN MORE SUNSHINE...WHICH WL BE DIMMED AT TIMES BY THE BKN HIER CLDS
DRIFTING INTO THE AREA FM THE NW. MIXING TO H8 ON NAM/GFS FCST SDNGS
YIELDS HI TEMPS MAINLY 45-50...EXCEPT IN THE LO 50S WHERE THE INCRSG
W WIND DOWNSLOPES OVER THE CENTRAL.
SUN NGT...AS NEXT SHRTWV/SFC LO DIGS SEWD THRU SCNTRL CANADA TO NEAR
LK WINNIPEG AND SFC HI PRES SHIFTS INTO THE OH RIVER VALLEY BY
12Z...A STRENGTHENING WSW FLOW WL DVLP OVER THE UPR LKS WITH H925
WINDS INCRSG UP TO 25-35 KTS BY 12Z MON. ALTHOUGH SOME MID/HI CLDS
ASSOCIATED WITH THE ISENTROPIC ASCENT ON THE 290K SFC WL BE OVER THE
UPR LKS...THESE CLDS WL BE RATHER THIN. PWATS AS LO AS 0.25-0.30
INCH INDICATE TEMPS WL STILL FALL FAIRLY SHARPLY OVER THOSE INTERIOR
LOCATIONS ESPECIALLY OVER THE SCNTRL THAT CAN DECOUPLE BEFORE THE
H925 FLOW STRENGTHENS TOO MUCH OVERNGT. LOCATIONS NEAR LK SUP SHOULD
BE WARMEST WITH DOWNSLOPE FLOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 503 AM EDT SUN OCT 7 2012
BY MONDAY MORNING THE UPPER GREAT LAKES WILL BE COMPLETELY WITHIN A
LARGE 500MB TROUGH THAT WILL ENCOMPASS ALL BUT THE FAR SW CORNER OF
THE NATION...EXTENDING FROM THE MAIN LOW OVER N CANADA THROUGH
HUDSON BAY.
FCST MODELS AGREE WITH THE ENHANCEMENT IN THE MAIN THROUGH SET UP
FROM S HUDSON BAY THROUGH CENTRAL SASKATCHEWAN BY MONDAY
AFTERNOON...SHIFTING TO CENTRAL MN BY DAYBREAK TUESDAY...AND SLOWLY
ACROSS LAKE SUPERIOR/UPPER MI TUESDAY. THE APEX OF THE TROUGH SHOULD
BE ACROSS THE CENTER OF THE CWA BY AT 12Z WEDNESDAY...BEFORE PUSHING
TO THE LOWER GREAT LAKES DURING THE DAY.
THE PROGRESSIVELY S SINKING /RUN TO RUN COMPARISON OVER THE PAST
COUPLE OF DAYS/ SFC LOW OVER S MANITOBA AND ND MONDAY MORNING WILL
RESULT IN INCREASED SW WINDS ACROSS THE UPPER GREAT LAKES. THE TRACK
OF THE SFC LOW IS STILL IN QUESTION...WITH THE 06/18Z RUN OF THE GFS
AROUND 6HRS FASTER THAN THE NAM/ECMWF/CANADIAN SOLUTIONS. THE 07/00Z
RUN OF THE GFS IS MUCH FARTHER TO THE N...BUT STILL TRACKING A BIT
FAST. THE TRACK WILL LIKELY BRING THE SFC LOW OVER W-CENTRAL LAKE
SUPERIOR BY 06Z TUESDAY...BEFORE SLIDING NE TO JAMES BAY BY 00Z
WEDNESDAY. GIVEN THIS TRACK...THE STRONGEST WINDS WILL LIKELY BE
AHEAD OF THE SYSTEM
/OUT OF THE SW MONDAY THROUGH MONDAY EVENING/.
TEMPERATURE WISE...INCREASED DOWNSLOPE S FLOW WILL BE COUNTERACTED
SLIGHTLY BY ADDITIONAL CLOUD COVER MONDAY AFTERNOON NEAR LAKE
SUPERIOR.
N/NW FLOW WILL RETURN TUESDAY NIGHT BEHIND THE EXITING SFC LOW.
850MB TEMPS OF -5 TO -8C MAY NOT BE ENOUGH TO CREATE MUCH MORE THAN
ENHANCED CLOUD COVER NEAR THE LAKE SUPERIOR SHORELINE TUESDAY NIGHT
INTO WEDNESDAY. HIGH PRESSURE NUDGING IN FROM THE CENTRAL PLAINS
WEDNESDAY SHOULD HELP IN PUSHING MUCH OF THE LOW LEVEL MOISTURE TO
OUR EAST. IT WILL NOT BE QUITE THAT SIMPLE THOUGH...WITH NW FLOW
ALOFT AND A CONTINUATION OF SMALLER SCALE WAVES BRINGING IN
ADDITIONAL MOISTURE.
THURSDAY THROUGH FRIDAY...
YET ANOTHER WAVE LOOKS TO SLIDE IN FROM THE NW THURSDAY OR THURSDAY
NIGHT. THE 06/12Z ECMWF WAS APPROX 12 HRS SLOWER THAN THE 06/18Z RUN
OF THE GFS WITH THIS WEAKER TROUGH. THE 07/00Z RUNS HAVE NEARLY
CORRECTED THIS ISSUE...WITH ONLY MINOR DIFFERENCES. STILL HAVE W TO
NW GALES TO 35KTS POSSIBLE OVER CENTRAL AND E LAKE SUPERIOR THURSDAY
AFTERNOON AND EVENING.
FRIDAY NIGHT THROUGH SATURDAY...
HIGH PRESSURE WILL ATTEMPT TO BUILD IN AT 500MB...WITH LITTLE MORE
THAN ZONAL FLOW BEING THE RESULT...AS THE NEXT LOW NEAR THE
4-CORNERS GETS SWEPT UP IN THE MAIN FLOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 719 AM EDT SUN OCT 7 2012
WITH SOME DAYTIME HEATING...EXPECT STRENGTHENING W WIND TO TURN
GUSTY AT ALL 3 TAF SITES...ESPECIALLY AT THE MORE EXPOSED CMX
LOCATION. DESPITE SOME INCRSG MID/HI CLDS...VFR CONDITIONS WL
PREVAIL AT ALL 3 SITES WITH W WIND ADVECTING DRY LLVL AIR INTO THE
UPR GRT LKS. PLAN ON SOME MARGINAL LLWS CONDITIONS TNGT WITH DVLPG
RADIATION INVRN/DECOUPLING SFC WIND.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT SUN OCT 7 2012
AS A HI PRES RIDGE BUILDS TOWARD THE OHIO RIVER VALLEY THRU TONIGHT
AND LO PRES MOVES SE THRU CANADA TOWARD MINNESOTA...EXPECT A
STRENGTHENING W WIND OVER LAKE SUPERIOR. AS IS TYPICAL FOR THIS
FLOW...THE STRONGEST WINDS UP TO 30 KTS ARE MOST LIKELY IN THE AREA
BETWEEN THE KEWEENAW AND ISLE ROYALE...WHERE SOME GALE FORCE GUSTS
TO 35 KTS ARE POSSIBLE LATER TODAY.
LOW PRESSURE NEARING FROM SOUTH CENTRAL CANADA WILL RESULT IN
INCREASING SOUTHWESTERLY WINDS MONDAY /WITH S GALES TO 35KTS OVER
PORTIONS OF E LAKE SUPERIOR MONDAY INTO MONDAY EVENING/. EXPECT THE
LOW TO TRACK FROM ND AND SOUTHERN MANITOBA TO W LS BY LATE MONDAY
AFTERNOON INTO MONDAY EVENING. THE LOW WILL PUSH NE TUESDAY...AS
ANOTHER DRYING HIGH PRESSURE SYSTEM ATTEMPTS TO BUILD IN FROM THE
CENTRAL PLAINS. GUSTS WILL DIMINISH TO 20-25KTS TUESDAY NIGHT. YET
ANOTHER LOW SHOULD SKIRT ACROSS OR JUST NORTH OF LAKE SUPERIOR
WEDNESDAY NIGHT...WITH WINDS BRIEFLY INCREASING WITH GUSTS NEARING
30KTS AGAIN WEDNESDAY OUT OF THE NW. HIGH PRESSURE SHOULD FINALLY
WIN OUT TOWARD THE END OF THE WORK WEEK...WITH ANOTHER ROUND OF WEST
TO NORTHWEST GALES TO 35KTS POSSIBLE THURSDAY AFTERNOON AND
EVENING...IN BETWEEN NEARING HIGH PRESSURE TO OUR W AND EXITING LOW
PRESSURE TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ267.
LAKE MICHIGAN...
GALE WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR
LMZ248-250.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC/KF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1001 AM EDT SUN OCT 7 2012
.SYNOPSIS...
COOL AND DRY WEATHER IS EXPECTED THROUGH EARLY AFTERNOON. RAIN
WILL OVERSPREAD THE AREA BY LATE TODAY BEFORE ENDING EARLY
TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT AND THIS MAY ALLOW FOR
SOME AREAS OF FROST TO FORM BY EARLY MONDAY MORNING. MOSTLY DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE OUR NEXT SHOT AT
WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
HV UPDATED GRIDS TO RMV POPS ACRS THE FAVORED LK EFFECT LOCATIONS
AS SHOWERS HV WEAKENED RAPIDLY THIS MRNG. HV ALSO RMVD SLGT CHC
POPS OVR THE SE AFT 18Z AS AIRMASS WL LKLY TAKE AWHILE TO SATURATE
DOWN, WITH MAINLY VIRGA EXPECTED BTWN 18Z-21Z. H5 TROF WL APPRCH
FM THE WEST AFT 21Z, RESULTING IN WIDESPREAD PCPN BREAKING OUT
ACRS THE CWA.
HV TWEAKED HRLY T/TD GRIDS TO COME INTO LINE WITH CURRENT OBS. WL
EVALUATE POTENTIAL FOR FROST/FREEZE TONIGHT WITH LATEST MODEL
DATA.
PREVIOUS DISCUSSIONS BLO...
700 AM UPDATE...
THE BAND OF LAKE EFFECT RAIN EAST OF LAKE ONTARIO IS FINALLY
SHOWING A SOUTHWARD PUSH WHILE WEAKENING RAPIDLY. WILL CONFINE
CHANCE POPS TO NORTH CENTRAL ONEIDA COUNTY AND EXTREME NORTHERN
ONONDAGA COUNTY THROUGH 15Z BEFORE KEEPING A DRY FORECAST. A
DEVELOPING AREA OF RAIN OVER SOUTH CENTRAL PA STILL LOOKS TO
SKIRT JUST SOUTHEAST OF OUR CWA BUT STILL FEEL SLIGHT CHANCE POPS
PRUDENT FOR NEPA AS A BUFFER. STILL LOOKING AT THE MAIN THREAT OF
RAIN TO COME AFTER 21Z TODAY WITH THE DISTURBANCE MOVING THROUGH
IL.
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SLIDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS MAINTAIN SOME CONSISTENCY WITH INDICATIONS OF
BEST SHOT OF PRECIPITATION ACROSS THE ENTIRE REGION DURING THIS
PERIOD TO BE IN THE WEDNESDAY TIME FRAME. THIS IS THEN LIKELY TO
BE FOLLOWED BY DEEPENING COLD AIR AND A MAINTAINED PRESENCE OF
SHOWER CHANCES TO THE LEE OF LAKE ONTARIO THROUGH THURSDAY WITH
IMPROVED WX OVER THE SOUTHERN HALF. ANOTHER WEAK UPPER TROF AND
SFC FRONT MAY SPREAD A QUICK SHOT OF SHOWERS INTO THE AREA ON
FRIDAY. A FAIRLY LARGE CENTER OF CONTINENTAL POLAR...FALL-
LIKE...HIGH PRESSURE WORKS IN FOR AT LEAST THE FIRST HALF OF NEXT
WEEKEND.
FOLLOWED THE HPC DAY 3-7 GUIDANCE CLOSELY WITH ONLY MINOR LOCAL
ADJUSTMENTS TO TEMPERATURES.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
7 AM UPDATE...
MVFR CIGS POSSIBLE NEXT HOUR OR SO AT KRME DUE TO LAKE CLOUDS
OTHERWISE VFR THROUGH THIS AFTERNOON. HIGH CLOUDS AROUND 15KFT
LOWER TO 5KFT BY 20Z...WITH RAIN OVERSPREADING THE SOUTHERN
TERMINALS BY 22Z. UP NORTH SHOWERS POSSIBLE TOWARD 0Z...BUT NOT AS
LIKELY AS FARTHER SOUTH AND WILL ONLY COVER WITH A TEMPO GROUP.
ACROSS THE SOUTHERN TERMINALS...MVFR CIGS AND PERHAPS
VSBYS...APPEAR MOST LIKELY ABOUT 1 TO 2 HOURS AFTER THE ONSET OF
THE RAIN AND WILL PLAY AS A TEMPO GROUP THROUGH 04Z.
LATER TONIGHT THE TERMINALS WILL BEGIN TO CLEAR OUT. BASED ON THE
TIMING OF THE CLEARING...MVFR TO IFR CIGS AND VSBYS POSSIBLE
EVERYWHERE EXCEPT AT KSYR/KRME DUE TO VALLEY OR LOW STRATUS. MOST
CONFIDENT AT KELM.
NW WINDS OVERNIGHT 5 KTS OR LESS THROUGH THIS MORNING...THEN SW FLOW
LATER TODAY 5-10 KTS BECMG NWLY ACRS CNTRL NY LATE AFTERNOON.
NORTHWEST WINDS AROUND 5 KTS TONIGHT.
OUTLOOK...
MON TO TUE...VFR.
WED...VFR/MVFR. SOME SHOWERS.
THU...VFR. SOME LAKE EFFECT RAIN SHOWERS NORTH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN/PVN
NEAR TERM...HEDEN/PVN
SHORT TERM...HEDEN
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
709 AM EDT SUN OCT 7 2012
.SYNOPSIS...
LAKE EFFECT RAIN SHOWERS WILL BE POSSIBLE EARLY THIS MORNING
ACROSS CENTRAL NEW YORK...OTHERWISE DRY WEATHER IS EXPECTED
THROUGH EARLY AFTERNOON. RAIN WILL OVERSPREAD THE AREA BY LATE
TODAY BEFORE ENDING EARLY TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT
AND THIS MAY ALLOW FOR SOME AREAS OF FROST TO FORM BY EARLY MONDAY
MORNING. MOSTLY DRY WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE
OUR NEXT SHOT AT WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
700 AM UPDATE...
THE BAND OF LAKE EFFECT RAIN EAST OF LAKE ONTARIO IS FINALLY
SHOWING A SOUTHWARD PUSH WHILE WEAKENING RAPIDLY. WILL CONFINE
CHANCE POPS TO NORTH CENTRAL ONEIDA COUNTY AND EXTREME NORTHERN
ONONDAGA COUNTY THROUGH 15Z BEFORE KEEPING A DRY FORECAST. A
DEVELOPING AREA OF RAIN OVER SOUTH CENTRAL PA STILL LOOKS TO
SKIRT JUST SOUTHEAST OF OUR CWA BUT STILL FEEL SLIGHT CHANCE POPS
PRUDENT FOR NEPA AS A BUFFER. STILL LOOKING AT THE MAIN THREAT OF
RAIN TO COME AFTER 21Z TODAY WITH THE DISTURBANCE MOVING THROUGH
IL. THE PREVIOUS AFD IS BELOW...
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SLIDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS MAINTAIN SOME CONSISTENCY WITH INDICATIONS OF
BEST SHOT OF PRECIPITATION ACROSS THE ENTIRE REGION DURING THIS
PERIOD TO BE IN THE WEDNESDAY TIME FRAME. THIS IS THEN LIKELY TO
BE FOLLOWED BY DEEPENING COLD AIR AND A MAINTAINED PRESENCE OF
SHOWER CHANCES TO THE LEE OF LAKE ONTARIO THROUGH THURSDAY WITH
IMPROVED WX OVER THE SOUTHERN HALF. ANOTHER WEAK UPPER TROF AND
SFC FRONT MAY SPREAD A QUICK SHOT OF SHOWERS INTO THE AREA ON
FRIDAY. A FAIRLY LARGE CENTER OF CONTINENTAL POLAR...FALL-
LIKE...HIGH PRESSURE WORKS IN FOR AT LEAST THE FIRST HALF OF NEXT
WEEKEND.
FOLLOWED THE HPC DAY 3-7 GUIDANCE CLOSELY WITH ONLY MINOR LOCAL
ADJUSTMENTS TO TEMPERATURES.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
7 AM UPDATE...
MVFR CIGS POSSIBLE NEXT HOUR OR SO AT KRME DUE TO LAKE CLOUDS
OTHERWISE VFR THROUGH THIS AFTERNOON. HIGH CLOUDS AROUND 15KFT
LOWER TO 5KFT BY 20Z...WITH RAIN OVERSPREADING THE SOUTHERN
TERMINALS BY 22Z. UP NORTH SHOWERS POSSIBLE TOWARD 0Z...BUT NOT AS
LIKELY AS FARTHER SOUTH AND WILL ONLY COVER WITH A TEMPO GROUP.
ACROSS THE SOUTHERN TERMINALS...MVFR CIGS AND PERHAPS
VSBYS...APPEAR MOST LIKELY ABOUT 1 TO 2 HOURS AFTER THE ONSET OF
THE RAIN AND WILL PLAY AS A TEMPO GROUP THROUGH 04Z.
LATER TONIGHT THE TERMINALS WILL BEGIN TO CLEAR OUT. BASED ON THE
TIMING OF THE CLEARING...MVFR TO IFR CIGS AND VSBYS POSSIBLE
EVERYWHERE EXCEPT AT KSYR/KRME DUE TO VALLEY OR LOW STRATUS. MOST
CONFIDENT AT KELM.
NW WINDS OVERNIGHT 5 KTS OR LESS THROUGH THIS MORNING...THEN SW FLOW
LATER TODAY 5-10 KTS BECMG NWLY ACRS CNTRL NY LATE AFTERNOON.
NORTHWEST WINDS AROUND 5 KTS TONIGHT.
OUTLOOK...
MON TO TUE...VFR.
WED...VFR/MVFR. SOME SHOWERS.
THU...VFR. SOME LAKE EFFECT RAIN SHOWERS NORTH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN
NEAR TERM...HEDEN
SHORT TERM...HEDEN
LONG TERM...JAB
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
740 AM EDT SUN OCT 7 2012
.SYNOPSIS...
A COLD FRONT OVER THE AREA WILL MOVE SOUTHEAST TO COASTAL SECTIONS
THIS MORNING. THE FRONT WILL BRIEFLY STALL OVER THE COASTAL AREAS
TODAY... BEFORE SHIFTING OFFSHORE THIS EVENING. THICK CLOUD COVER
AND A CHILLY AIR MASS WILL HOLD OVER THE REGION THROUGH MONDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 300 AM SUNDAY...
EARLY MORNING...
THE SURFACE COLD FRONT HAS PUSHED SOUTH THROUGH THE AREA SINCE LAST
EVENING...NOW STRETCHING FROM KGSP TO KMEB TO KPGV. A PATCH OF
SHOWERS MOVING NORTHEAST BETWEEN KGSO AND KRDU IS BEING AIDED BY A
WEAK DISTURBANCE LOFT IN WATER VAPOR AND INCREASING ISENTROPIC
ASCENT. THE 00Z KGSO RAOB SHOWERS ENOUGH INSTABILITY ABOVE THE
STRENGTHENING COLD DOME TO SUPPORT AT LEAST A FEW SPORADIC LIGHTNING
STRIKES THROUGH EARLY MORNING. THE HEAVIER SHOWERS A PRODUCING
BETWEEN ONE TO TWO TENTHS OF AN INCH OF RAINFALL. BASED ON RAP
ISENTROPIC FIELDS AND HRRR SIMULATED REFLECTIVITY...EXPECT THESE
SHOWERS TO CONTINUE MOVING OFF TO THE NORTHEAST AND OUT OF THE
NORTHERN PIEDMONT/COASTAL PLAIN BY 10Z.
TODAY...
A SHORTWAVE CURRENTLY APPROACHING THE MID MS VALLEY REGION WILL
SWING ACROSS THE OH VALLEY REGION THIS AFTERNOON..WITH PRECIP
SPREADING EAST AND EXPANDING ALONG THE 850MB FRONT THAT HAS STALLED
FROM THE LOWER TN VALLEY TO THE MID ATLANTIC STATES. WHILE THE FLOW
AHEAD OF THE SHORTWAVE WILL STRENGTHEN THIS AFTERNOON...WINDS IN THE
295-305K LAYER STAY RELATIVELY PARALLEL TO FRONTAL ZONE AND
CROSS-SECTIONS SHOW MUCH DEEPER MOISTURE ALONG AND WEST OF THE
MOUNTAINS. THUS...WHILE OVERCAST SKIES WILL DEVELOP THIS MORNING
DUE TO MOISTENING AT THE TOP OF THE STABLE LAYER...PRECIP AMOUNTS
SHOULD BE RELATIVELY LIGHT..WITH MODELS NOW ONLY SHOWING A TENTH OF
AN INCH OR LESS IN THE NORTHWEST PIEDMONT.
TO THE SOUTH AND EAST...THE COLD FRONT WILL STALL ACROSS SC AND
SOUTHEAST NC THIS MORNING. A WEAK WAVE OF LOW PRESSURE IS FORECAST
TO MOVE FROM CENTRAL NC TOWARD THE OBX THIS AFTERNOON...WHICH SHOULD
HELP TRIGGER SOME SHOWERS AND STORMS IN THE VICINITY OF THE FRONTAL
ZONE. FORECAST SOUNDINGS AT KFAY LOOK MUCH TOO STABLE FOR ANY NEAR
SURFACE BASED CONVECTION...BUT MUCAPE FORECASTS SHOW AROUND 400-600
J/KG JUST TO THE NORTH OF THE FRONT...SO AN ISOLATED AND ELEVATED
STORM COULD BE POSSIBLE OVER THE SOUTHEAST CWA. HOWEVER...THE COLD
FRONT IS FORECAST TO SURGE FURTHER SOUTH AND EAST AFTER 18Z (IN THE
WAKE OF THE SURFACE WAVE)...WITH THE POTENTIAL FOR AN THUNDER
BECOMING LESS LIKELY WITH TIME. THE POP FORECAST WILL SHOW A STRONG
GRADIENT FROM 80 IN THE NORTHWEST TO 25 IN THE SOUTHEAST.
THE RISE IN TEMPS TODAY WILL SOMEWHAT DEPEND ON HOW MUCH PRECIP
FALLS...WITH LESS RISE EXPECTED IN THE NORTHWEST PIEDMONT WITH
PERIODS OF RAIN EXPECTED THROUGH THIS AFTERNOON. THINNER MOISTURE
PROFILES AND A LITTLE MORE HEATING NEAR THE FRONT MAY ALLOW FOR SOME
LOWER 70S IN THE FAR SOUTHEASTERN AREAS. MID 50S TO LOWER 70S
ARE EXPECTED WITH A SHARP GRADIENT ACROSS THE PIEDMONT.
TONIGHT AND MONDAY...
AS HIGH PRESSURE EXPANDS ACROSS THE OHIO VALLEY TONIGHT...COOL AND
DRIER LOW LEVEL AIR WILL WORK SOUTH INTO THE AREA WITH DEW POINTS
FALLING INTO THE 40S CWA-WIDE. THIS WILL ALLOW FOR A LITTLE MORE
COOLING AND LOWS REACHING THE 42-49 RANGE AND NO RAIN OVERNIGHT.
ANOTHER SHORTWAVE OVER CO/WY THIS MORNING WILL SWING FURTHER SOUTH
TOWARD THE TN VALLEY MONDAY...WITH A LITTLE BETTER RAIN CHANCES OVER
ALL OF CENTRAL NC AS THE 850MB DRIFTS EASTWARD AND THE RIGHT
ENTRANCE REGION OF THE PERSISTENT UPPER JET TO OUR NORTH SHIFTS
OVERHEAD. ISENTROPIC ASCENT...WHILE STRONGER...IS STILL NOT VERY
IMPRESSIVE...SO RAINFALL TOTALS MAY AGAIN BE LIGHT. HOWEVER...
TEMPS WILL LIKELY NOT RISE MUCH AT ALL ACROSS THE CWA AS A BETTER
COLD AIR DAMMING AIRMASS DEVELOPS...WITH MOST GUIDANCE INDICATING
LOW TO MID 50S...POSSIBLY 60 IN THE FAR SOUTHEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 220 AM SUNDAY...
FOR MONDAY NIGHT: PATTERN REMAINS DOMINATED BY FAST MID LEVEL
CYCLONIC FLOW... ON THE COLD SIDE OF A SURFACE BOUNDARY... RESULTING
IN CHILLY AND HIGHLY UNSETTLED WEATHER. THE PARENT HIGH SUPPORTING
THE DAMMING REGIME WILL BE CENTERED OVER THE COAST OF MAINE AND
CANADIAN MARITIMES WHILE EXTENDING TO THE SW... THROUGH THE NC
FOOTHILLS AND WRN PIEDMONT. MOIST UPGLIDE AT 290K-295K IS NOT
PARTICULARLY INTENSE OVER CENTRAL NC BUT THE PRESENCE OF A DEEP
NEARLY SATURATED LAYER AT 950 MB TO 750 MB SHOULD MAKE THIS LIFT
VERY PRODUCTIVE IN TERMS OF CONDENSATION AND PRECIP... AND THE
FAST-MOVING PASSAGE OF A MID LEVEL WAVE THROUGH THE AREA SHOULD
FURTHER AUGMENT LIFT. UPPER DIVERGENCE OVER CENTRAL NC... IN THE
RIGHT ENTRANCE REGION OF THE 120+ KT UPPER JET CORE OVER AND JUST
OFF THE NORTHEAST COAST ON MONDAY... QUICKLY DIMINISHES AS THE JET
MOVES AWAY TO THE NE... AND FORECAST SOUNDINGS CONFIRM DRYING ALOFT
OVERNIGHT... HOWEVER THE COLUMN WILL REMAIN NEARLY SATURATED BELOW
750 MB WITH LOWERING CEILINGS OVERNIGHT WITHIN THE PERSISTENT
DAMMING-INDUCED STABLE LAYER. THE MOIST UPGLIDE LARGELY ENDS AFTER
MIDNIGHT... AS THE WINDS ALOFT DECELERATE AND THE MID LEVEL WAVE
EXITS ALONG WITH THE UPPER JET-RELATED FORCING FOR ASCENT. EXPECT A
GRADUAL LOWERING OF LIGHT RAIN AND DRIZZLE COVERAGE FROM SOUTH TO
NORTH THROUGH THE NIGHT... ENDING LAST IN THE FAR NORTHWEST CWA
(ROXBORO THROUGH THE TRIAD) WHERE SLOPED ASCENT WILL LINGER ALONG A
WEAK 925 MB FRONTAL ZONE. LOW CLOUDS... AREAS OF FOG... AND POCKETS
OF DRIZZLE ARE LIKELY TO PERSIST AREAWIDE THROUGH DAYBREAK. TEMPS
SHOULD DROP NO MORE THAN 10 DEGREES OR SO FROM THE PRECEDING CHILLY
DAYTIME TEMPS... YIELDING LOWS OF 42-49.
FOR TUESDAY/TUESDAY NIGHT: THE MID LEVEL CANADIAN VORTEX WOBBLES
OVER HUDSON BAY WHILE ITS TRAILING BROAD TROUGHING SHIFTS SLOWLY
FROM THE UPPER MIDWEST TOWARD MI WHILE AMPLIFYING. THE STRONG
(ROUGHLY 1030 MB) PARENT SURFACE HIGH CENTERED OVER NOVA SCOTIA
EARLY TUESDAY CONTINUES MOVING NORTHEAST OVER THE MARITIMES...
CAUSING THE TRAILING RIDGE TO LOSE ITS GRIP ON CENTRAL NC AND LEAVE
BEHIND A DISCONNECTED WEAK RESIDUAL COOL STABLE POOL. THIS
SEPARATION FROM THE SUPPLY OF COOL DRY AIR TO MAINTAIN THE DAMMING
AIR MASS WILL ALLOW IT TO BECOME VULNERABLE TO HORIZONTAL DISPERSION
AND CONVECTIVE MIXING AS THE DRIER AIR ALOFT ALLOWS STRONG HEATING
FROM THE TOP... ALTHOUGH TYPICALLY THIS EROSION PROCESS OFTEN TAKES
QUITE A WHILE PARTICULARLY WITH A STABLE LAYER THIS DEEP. WILL BE
SLOW TO GET RID OF THE WEDGE-SUPPORTED CLOUDS ON TUESDAY... TRENDING
GRADUALLY TO PARTLY CLOUDY LATE IN THE DAY. THE WEAK HIGH WILL DRIFT
BACK TOWARD THE SW TO OVER THE INTERIOR SOUTHEAST STATES TUESDAY
NIGHT... AND WITH THE RESULTING MODIFICATION OF THE AIR MASS...
THICKNESSES WILL START TO REBOUND BUT SHOULD STILL HOLD WELL BELOW
NORMAL FOR ANOTHER DAY GIVEN THE DELAYED HEATING. EXPECT MODEST
WARMING WITH HIGHS OF 60-68. EXPECT FAIR SKIES TUESDAY NIGHT WITH
CONTINUED DRYING ALOFT... ALTHOUGH RECOVERING SURFACE DEW POINTS
COMBINED WITH LIGHT WINDS IS LIKELY TO LEAD TO DEVELOPMENT OF GROUND
FOG OVERNIGHT. LOWS 47-52. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 250 AM SUNDAY...
EXPECT GENERALLY DRY WEATHER BUT WITH ROLLER COASTER TEMPS AS A
SUCCESSION OF FRONTS DROPS THROUGH THE REGION.
FOR WEDNESDAY/WEDNESDAY NIGHT: THE MID LEVEL TROUGH AXIS SWINGS
SWIFTLY ENE THROUGH THE GREAT LAKES AND NORTHEAST STATES... DRAGGING
A SURFACE COLD FRONT THROUGH CENTRAL NC WEDNESDAY AFTERNOON. GIVEN
THAT THE SURFACE HIGH CENTER WILL BE LOCATED TO OUR SOUTH AND SW...
THERE WILL BE LITTLE TO NO MOISTURE FLUX AHEAD OF THE FRONT... THUS
IT SHOULD COME THROUGH DRY. THICKNESSES ARE PROJECTED TO BE AT OR
JUST ABOVE NORMAL WEDNESDAY... TRANSLATING TO HIGHS IN THE MID TO
UPPER 70S. YUKON-SOURCE HIGH PRESSURE BUILDING IN BEHIND THE FRONT
SHOULD SEND THICKNESSES PLUNGING BACK DOWN BELOW NORMAL... WITH LOWS
IN THE MID 40S TO NEAR 50.
FOR THURSDAY THROUGH SATURDAY: THE SURFACE HIGH IS EXPECTED TO BUILD
OVER NC ON THURSDAY... WITH BROAD/FAST/CYCLONIC MID LEVEL FLOW FROM
SW CANADA ACROSS THE NORTHEAST STATES. FAIR AND DRY THURSDAY WITH
INITIALLY COOL BUT MODERATING TEMPS. A MINOR WAVE DROPS INTO THE
LONGWAVE TROUGH OVER THE GREAT LAKES... AND THIS ACCOMPANYING
SURFACE COLD FRONT WILL APPROACH NC FROM THE NNW ON FRIDAY. ONCE
AGAIN... VERY LITTLE MOISTURE IS AVAILABLE AHEAD OF AND ALONG THE
FRONT AND LIFT WILL BE WEAK... SO EXPECT NO MORE THAN ISOLATED
SHOWERS AT BEST. TEMPS SHOULD BOUNCE BACK UP TO NEAR NORMAL AHEAD OF
THE FRONT FRIDAY. YET ANOTHER COOL HIGH BUILDS IN BEHIND THE FRONT
FROM THE NORTH... ITS CENTER MOVING FROM OVER SW MI TO OFF THE
NJ/DELMARVA COAST FROM FRIDAY EVENING THROUGH SATURDAY AS IT RIDGES
SOUTHWARD THROUGH CENTRAL NC. EXPECT A SLIGHT COOLDOWN OF AROUND A
CATEGORY FOR SATURDAY... WITH CONTINUED DRY WEATHER. -GIH
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 740 AM SUNDAY...
A SMALL CLUSTER OF SHOWERS AND STORMS HAS DEVELOPED OVER
SOUTHWESTERN NC AND IS MOVING RELATIVELY QUICKLY TO THE EAST ALONG A
STALLED OUT COLD FRONT NEAR THE NC/SC BORDER. BRIEF HEAVY RAIN AND
A GUST TO AROUND 30KT WITH THE HEAVIEST SHOWERS. NORTH OF THE
FRONT...CEILINGS ARE GENERALLY MVFR WITH SOME IFR CONDITIONS
REPORTED AT KGSO/KINT. THESE LOWER CEILINGS WILL PERSIST AT
KINT/KGSO/KRDU/KRWI THROUGH THIS AFTERNOON...WITH SOME SCATTERING
AND IMPROVEMENT POSSIBLE AT KFAY IS THE FRONT LIFTS BACK TO THE
NORTH OF THE TERMINAL...AS RECENT MODEL RUNS SUGGEST.
DRIER AIR IS EXPECTED TO FILTER INTO THE ARE THIS EVENING AND
OVERNIGHT...LEADING TO A TEMPORARY IMPROVEMENT OF CEILINGS TO MVFR
OR VFR. HOWEVER...ANOTHER DISTURBANCE ALOFT IS EXPECTED TO
IMPACT THE AREA MONDAY...WITH WIDESPREAD MVFR/IFR CEILINGS TO
REDEVELOP.
OUTLOOK...
LOW CEILINGS WILL LIKELY CONTINUE THROUGH AT LEAST TUESDAY...WITH
IMPROVEMENT IN AVIATION CONDITIONS BY THE MIDDLE TO END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...BLS
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1008 AM CDT SUN OCT 7 2012
.DISCUSSION...THE 11Z HRRR AND 06Z GFS HAVE SPED UP THE TIMING OF
A SHORTWAVE DIVING ACROSS SASKATCHEWAN TODAY AND INTO THE
NORTHWESTERN CWA LATER THIS AFTERNOON. HOWEVER...THE SHORT RANGE
MODELS PROG THIS ACTIVITY TO CROSS THE MT/ND BORDER AFTER 21Z
TODAY. AS A RESULT...UPDATED THE FORECAST TO INDICATE DRY
CONDITIONS AREAWIDE UNTIL 21Z...THEN INCREASED PRECIP CHANCES FOR
THE EXTREME NORTHWEST AFTER 21Z. THE THERMAL PROFILES INDICATE
THAT ANY PRECIP THAT DOES FALL SHOULD BE IN THE FORM OF ALL
LIQUID. ALSO ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS TO ACCOUNT
FOR THE CURRENT OBS/TRENDS. THE UPDATED GRIDDED AND TEXT PRODUCTS
WILL BE OUT SHORTLY.
&&
.AVIATION...INCREASING VFR CLOUDINESS OVER WESTERN AND CENTRAL
NORTH DAKOTA CAN BE EXPECTED AS WEAK WARM FRONT MOVES THROUGH.
SOME WIND GUSTS WILL BE POSSIBLE THIS AFTERNOON IN HIGHER ELEVATIONS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TM...UPDATE
HW...AVIATION
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
649 AM EDT SUN OCT 7 2012
.SYNOPSIS...
MID/UPPER LEVEL WAVE STREAKS THROUGH TODAY. ANOTHER WAVE SKIRTS
SOUTHERN AND EASTERN PORTIONS OF THE REGION MONDAY. A THIRD WAVE IS
POSSIBLE MONDAY NIGHT INTO TUESDAY. COLD FRONT ON WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
630AM UPDATE...
FINESSED POPS THIS MORNING TO REFLECT QUICKER EXODUS OF -RA ACROSS
MTNS...PER LATEST RUC AND UPSTREAM TRENDS ACROSS TN VALLEY.
OTHERWISE NO OTHER CHANGES ATTM.
PREVIOUS DISCUSSION BELOW...
QUITE A CHALLENGING FCST IN THE NEAR TERM. FIRST ORDER OF
BUSINESS IS UPR LVL SYS TDY...COUPLED WITH SFC WAVE RIDING ALONG
STALLED OUT BOUNDARY TO S OF CWA. WEAK ECHOES NOTED CURRENTLY ON
RADAR ACROSS SW VA AND WV MTNS...WITH SOMEWHAT HEAVIER PCPN ACROSS
CUMBERLAND PLATEAU. MDL CONSENSUS IS FOR GENERALLY LIGHT QPF THIS
MORNING ACROSS SW VA...EXTENDING UP THE WV MTNS WITH SFC WAVE.
BEST ISENTROPIC LIFT LOOKS TO BE ALONG AND E OF THE EASTERN SLOPES
AND THIS IS WHERE HIGHEST POPS WERE PLACED. STILL SOME QUESTION
ABOUT HOW FAR WEST PCPN IS ABLE TO MAKE IT...GIVEN LACK OF GOOD
ISENTROPIC LIFT AND STOUT LLVL DRY LYR. WILL ALLOW SCHC POPS TO
EXTEND JUST W OF I79/US119 CORRIDOR...KEEPING WESTERN LOWLANDS AND
SE OH DRY THIS MORNING. WILL WATCH FOR APPROACH OF S/W TROF THIS
AFTN WHICH WILL HOOK UP WITH LINGERING MOISTURE OVER AREA FOR SCT
SHRA ACROSS SE OH AND N HALF OF WV. HAVE THIS COVERED WITH SOME
CHC POPS. SHOULD SEE SOME CLRING ACROSS NE KY...SW VA AND S WV
LATE THIS AFTN. ROLLED WITH LATEST LAMP GUIDANCE FOR TEMPS TDY
RESULTING IN UPR 40S TO LWR 50S OUTSIDE OF MTNS...WITH GENERALLY
40S IN HIGHER ELEVATIONS. KEPT A SMALL WINDOW THIS MORNING FOR A
RA/SN MIX AT SNOWSHOE BUT THIS IS LOOKING DOUBTFUL AS MDLS HAVE
COME IN SLIGHTLY WARMER.
MAY STILL SEE SOME STRATOCU ACROSS SE OH AND N WV THIS EVE BEFORE
TRYING TO DISSIPATE BY MIDNIGHT. HOWEVER...ANOTHER UPR LVL
DISTURBANCE WILL BE QUICKLY APPROACHING IN BASE OF MEAN TROF. THIS
SPELLS HEADACHES IN MINT FCST TONIGHT. MOS NUMBERS CONT TO COME IN
ON THE COLD SIDE WITH GENERALLY LOW TO MID 30S OUTSIDE OF THE
MTNS...WITH UPR 20S TO LWR 30S IN HIGH TERRAIN. HOWEVER...MDLS SHOW
MID/HI CLDS QUICKLY STREAMING NE INTO THE AREA LATE TONIGHT...WITH
GFS MOST BULLISH ON THIS. CRITICAL ARRIVAL TIME SLATED FOR 09-12Z.
CIRRUS CURRENTLY ON GRAVEYARD SHIFT ALLOWED TEMPS TO SPIKE UPWARDS
OF 5F AS IT MOVED IN...NOT HANDLED BY MDLS. ANOTHER FACTOR IS DRIER
AIR IN FORM OF LWR DWPTS TRYING TO SNEAK INTO E OH WHICH WOULD
RESULT IN TOO HIGH OF DWPT DEPRESSION FOR FROST SHOULD 32F OR LWR
NOT BE ACHIEVED. REGARDLESS...TOO MUCH UNCERTAINTY TO MAKE ANY CHGS
TO HEADLINES WITH THIS PACKAGE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MODELS ARE SHOWING A WAVE SKIRTING SOUTHEASTERN PORTIONS OF THE
FORECAST AREA MONDAY. DIFFERENCES STILL EXIST ON HOW FAR NORTH THE
PRECIPITATION WILL MAKE IT. WILL ADD SOME POPS IN THIS REGION BUT
KEEP IN THE CHANCE CATEGORY DUE TO THE UNCERTAINTY.
NAM IS SHOWING YET ANOTHER WAVE MONDAY NIGHT INTO TUESDAY. OTHER
MODELS DO NOT HAVE THIS FEATURE CAUSING PRECIPITATION IN THE
FORECAST AREA. LAST NIGHT NAM WAS FURTHER NORTH THAN OTHER MODELS
WITH WAVE ON MONDAY...AND OTHER MODELS HAVE NOW TRENDED TOWARD THE
NAM. THEREFORE...WILL GIVE THE NAM MORE WEIGHT THAN NORMAL IN THIS
SITUATION AND ADD SOME SLIGHT CHANCE POPS. THIS ALSO EFFECTS
TEMPERATURES AND FROST POTENTIAL.
MODELS IN FAIRLY GOOD AGREEMENT WITH A COLD FRONT MOVING THROUGH ON
WEDNESDAY. WILL ADJUST TIMING OF POPS SOME DUE TO SUCH GOOD
AGREEMENT.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE GFS IS SHOWING A STRONG DEEP H5 TROUGH WITH STRONG ELONGATED
VORT MAX AROUND ITS PERIPHERY ACROSS THE GREAT LAKES AND PA. THIS
SYSTEM WILL BRING A COLD FRONT ACROSS SOUTHEAST OH AND WV
WEDNESDAY. THE GFS/ECMWF CONTINUE TO SHOW PRESSURE GRADIENT
TIGHTENING UP ON TUESDAY NIGHT/WEDNESDAY AHEAD OF A COLD FRONT.
THIS SOUTHWEST FLOW WILL INCREASE H85 TEMPERATURES ABOUT 7 DEGREES
CELSIUS BY 12Z WED. NOTICED NO MAJOR CHANGES FROM HPC GUIDANCE FROM
PREVIOUS FCST. KEPT CHANCE POPS FOR WED AS WITH RAIN SHOWERS AND NO
THUNDER. THESE CHANCE POPS WILL DIMINISH WED NIGHT...AND EXIT EAST
TO THE NORTHEAST MOUNTAINS BY THURSDAY MORNING. MOISTURE LOOKS
LIMITED ATTM...AND H85 TEMPERATURES REMAIN ABOVE FREEZING SUGGESTING
ALL PCPN WILL FALL AS LIQUID.
EXPECT BROAD AND DRY HIGH PRESSURE OVERHEAD THURSDAY FOR MOSTLY
CLEAR SKIES...H85 TEMPS AROUND 9C PER GFS/ECMWF.
ANOTHER BUT WEAKER AND LESS AMPLIFY H5 TROUGH WILL CROSS THE GREAT
LAKES REGION FURTHER NORTH OUR AREA ON FRIDAY. MODELS SUGGEST A
ANOTHER BUT WEAKER COLD FRONT WITH LIMITED MOISTURE COULD PRODUCE
LOW CHANCES FRIDAY...WHILE A SOUTHERN STREAM SYSTEM LIFTS NORTHEAST
WITH A POSSIBLE WARM FRONT UNDER SOUTHWEST FLOW NEXT SATURDAY.
INTRODUCED CHANCE POPS SAT AND SAT NIGHT ACCORDINGLY.
USED HPC GUIDANCE FOR TEMPS AS A BASED...TWEAKING UP TEMPS UNDER
SOUTHWEST FLOW...AND DOWN DURING CLEAR NIGHTS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
12Z SUNDAY THROUGH 12Z MONDAY... AN UPR LVL DISTURBANCE WILL MOVE
THROUGH TDY. BULK OF PRECIPITATION WITH THIS WILL BE MAINLY
CONFINED TO SW VA AND THE WV MTNS...WITH CIGS GRADUALLY
DETERIORATING TO MVFR...THEN IFR...ESPECIALLY ACROSS THE HIGHER
TERRAIN AFTER 12 TO 15Z. ELSEWHERE...MID/HI CLDS WILL PREVAIL
THRU MORNING. BY EARLY THIS AFTN THOUGH...CIGS MAY LWR INTO MVFR
RANGE ACROSS SE OH AND N WV...TO INCLUDE KCRW...KPKB...AND KCKB AS
UPR WAVE MOVES ACROSS. SHRA CHCS TOO LOW TO INCLUDE IN THOSE TAF
SITES ATTM.
BULK OF PRECIPITATION WILL BEGIN TO MOVE EAST OF THE AREA BY
18Z. FLIGHT CONDITIONS WILL IMPROVE TO MVFR BY 00Z AT MTN
SITES AND KCKB...WITH A RETURN TO VFR CONDITIONS ACROSS REMAINDER
OF AREA BY 21Z.
SOME LINGERING LLVL MOISTURE IN FORM OF 4 TO 5 THSD FT STRATOCU
MAY LINGER THIS EVE ACROSS THE MTNS. OTHERWISE SOME EVE CLEARING
WILL GIVE WAY TO AN INCREASE ONCE AGAIN OF MID/HI CLDS BY 12Z
MON...MAINLY ACROSS THE S. SOME MVFR FG POSSIBLE ACROSS RVR
VALLEYS LATE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF PRECIPITATION AND ONSET
OF LOWER CIGS TODAY MAY VARY FROM FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY M H H H M H H H H M H H
HTS CONSISTENCY H H H H H H H M H H H H
BKW CONSISTENCY H M L M L L H H H M H M
EKN CONSISTENCY H H H H M M M M H H H M
PKB CONSISTENCY H H H H H H H M M M M H
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 12Z MONDAY...
IFR CIGS POSSIBLE MONDAY ACROSS HIGHER TERRAIN.
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
WVZ035>039-046-047.
OH...FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
OHZ066-067.
KY...NONE.
VA...NONE.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
WVZ035>039-046-047.
OH...FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR
OHZ066-067.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...ARJ
AVIATION...30
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
724 AM EDT SUN OCT 7 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL TRACK ACROSS THE REGION FROM THE
WEST AND OVER A LAYER OF COOLER AIR. THIS WILL RESULT IN A WET AND
COOL DAY SUNDAY. MORE RAIN AND COOL TEMPERATURES ARE EXPECTED MONDAY
AS ANOTHER UPPER LEVEL DISTURBANCE ENTERS FROM THE SOUTHWEST.
BY TUESDAY...DRIER CONDITIONS WILL ARRIVE AND CONTINUE INTO THE
LATER PART OF THE WEEK UNDER HIGH PRESSURE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM EDT SUNDAY...
WATER VAPOR SATELLITE IMAGERY INDICATES A WEAK SHORTWAVE ACROSS
EASTERN KY INTO CENTRAL TN. THIS FEATURE IS IN ADVANCE OF A STRONGER
UPPER LEVEL DISTURBANCE LOCATED ACROSS IOWA INTO MO. HRRR AND LOCAL
WRF MODELS DEPICT THIS AREA OF RAIN WELL...UNDER THE RR QUAD OF A
LIFTING UPPER LEVEL JET. WITH GOOD ISENTROPIC LIFT CONTINUING INTO
EARLY AFTERNOON AND THE APPROACH OF MIDWESTERN UPPER LEVEL
SHORTWAVE...PRECIP SHOULD EXPAND IN COVERAGE. AS A RESULT...WILL
CONTINUE TO CARRY LIKELY POPS INTO THE EARLY AFTERNOON.
BEHIND THIS SYSTEM...LOW LEVEL WINDS VEER TO THE NORTHWEST AND
ISENTROPIC DOWNGLIDE BEINGS LATE THIS AFTERNOON/EARLY THIS
EVENING...WHICH WILL GRADUALLY BRING AN END TO THE PRECIP.
CLOUDS...WEAK CAA...AND PRECIP WILL KEEP TEMPERATURES FROM RISING
MUCH AT ALL TODAY. IN FACT...TEMPS MAY DROP TODAY.
THEREFORE...LEANED TOWARD THE COOLER MAV AND LOCALLY DERIVED MOS
GUIDANCE FOR HIGHS TODAY.
THE NEXT UPPER LEVEL SYSTEM ZIPPING INTO THE LOWER OHIO VALLEY BY
LATE SUNDAY NIGHT/EARLY MONDAY MORNING WILL BACK LOW LEVEL WINDS AND
SET UP A BAROCLINIC ZONE ACROSS THE SOUTHERN PORTION OF OUR FORECAST
AREA LATE TONIGHT. THIS MAY GENERATE SOME LIGHT PRECIP IN THIS
REGION...AND KEPT SMALL POPS HERE LATE TONIGHT. IN THE NORTH...THE
THREAT FOR FROST APPEARS LOW WITH A WET GROUND/WARM SOIL TEMPS AND
CLOUD COVER. IF ANY CLEARING CAN BE MAINTAINED...SOME PATCHY FROST
IN THE DEEP MOUNTAIN VALLEYS FROM BURKES GARDEN INTO SOUTHEAST WV
MAY DEVELOP.
WITH THE INCREASE IN CLOUDS...USED A MAV/MET MIX FOR LOWS WHICH ARE
CLOSE TO OUR LOCALLY DERIVED MOS.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 400 AM EDT SUNDAY...
A JET COUPLET PROVIDING DIFFLUENCE ALOFT WILL COMBINE WITH
FRONTOGENESIS JUST ABOVE THE GROUND ACROSS SE WEST VA TO GENERATE
LIGHT RAIN ON MONDAY MOSTLY BLUE RIDGE AND WEST. ALTHOUGH QPF WILL
BE SMALL...POSSIBLY ONLY A FEW HUNDREDTHS...SPOTTY DRIZZLE WILL HELP
TO MAKE THIS A DAMP AND COOL DAY. WITH PRECIP AND E TO NE FLOW
CONTINUING...CAN`T SEE TEMPS GOING MUCH OF ANYWHERE...AND ALL OF THE
GUIDANCE WITH THE EXCEPTION OF THE LOCALLY BIAS CORRECTED ECMWF
LOOKS TOO WARM. QUITE POSSIBLE SOME OF THE COOLEST SPOTS DON`T EVEN
REACH 45F WITH THE POSSIBILITY THAT MANY PLACES DON`T REACH 50F.
CLOUDS BREAKING LATE MONDAY NIGHT SHOULD KEEP TUESDAY MORNING LOW
TEMP A FEW WARMER THAN GUIDANCE...AND A RATHER WET AND WARM GROUND
WITH TEMPS NOT FALLING INTO THE 30S UNTIL LATE SHOULD PRECLUDE ANY
FROST. WITH ABUNDANT LLVL MOISTURE AND EASTERLY COMPONENT CONTINUING
BLUE RIDGE AND EAST...HELD ONTO CLOUDS AND WENT WITH MAX T CLOSER TO
THE 2M NAM VALUES TUESDAY. WEDGE FIGURES TO BE SLOWER TO LIFT OUT
THAN OTHER MODELS DEPICT. THIS COULD BE ONE OF THOSE DAYS WHERE BCB
IS WARMER THAN ROA AND LWB IS WARMER THAN DAN/LYH. CLOUDS SHOULD
BREAK WEST OF THE BLUE RIDGE WITH MORE WESTERLY COMPONENT TUESDAY.
SHOWERS SHOULD CRUMBLE ACROSS WEST VA WITH FRONT THAT APPROACHES ON
WEDNESDAY WITH DEEP DOWNSLOPING FLOW AHEAD OF IT. BIG TEMP REBOUND
THOUGH BLUE RIDGE AND EAST...EASILY THE BEST DAY OF THE NEXT SEVERAL
WITH MAX T ONCE AGAIN IN THE 70S ON WEDNESDAY. A BETTER DRY PUNCH
SETS THE STAGE FOR SOME NEAR FREEZING TEMPS PERHAPS THURSDAY MORNING
ACROSS SE WEST VA...EXTREME SW VA AND NW NC.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 400 PM EDT SATURDAY...
ANOTHER FRONTAL BOUNDARY APPROACHES DURING THE WEEKEND AND
ARRIVES EARLY NEXT WEEK...ALLOWING TEMPERATURES TO MODERATE.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
AS OF 715 AM EDT SUNDAY...
WIDESPREAD SHOWERS EARLY THIS MORNING WITH AREAS OF MVFR CEILINGS WILL
CONTINUE INTO THE EARLY AFTERNOON DUE AN APPROACHING UPPER LEVEL DISTURBANCE.
ONCE THE UPPER LEVEL SYSTEM MOVES EAST AND WEAK LOW LEVEL
NORTHWEST FLOW FORMS...CEILINGS TO RISE LATE THIS AFTERNOON AND THIS
EVENING TO VFR CONDITIONS.
THESE IMPROVING CONDITIONS WILL ONLY BE TEMPORARY AS ANOTHER UPPER
LEVEL SYSTEM MOVING OVER THE REGION MONDAY WILL BRING WIDESPREAD
MVFR/IFR CIGS AND LIGHT PRECIPITATION. HIGH PRESSURE BUILDING
OVER THE AREA FOR TUESDAY WILL FINALLY BRING VFR CONDITIONS
THAT ARE EXPECTED TO LAST THROUGH THURSDAY...ALTHOUGH A PERIOD OF
MVFR CIGS POSSIBLE IN THE MTNS WITH A COLD FRONTAL PASSAGE
WEDNESDAY.
&&
.EQUIPMENT...
THE KFCX DOPPLER RADAR...WHICH SERVES ROANOKE AND THE SURROUNDING
AREAS...WILL REMAIN DOWN FOR THE NEXT FEW DAYS AS THE INSTALLATION
OF THE NEW DUAL-POL TECHNOLOGY CONTINUES. THE RADAR MAY RETURN TO
SERVICE AS EARLY AS THE MIDDLE OF NEXT WEEK.
NEIGHBORING DOPPLER RADARS AT STERLING VA (KLWX)...WAKEFIELD VA
(KAKQ)...RALEIGH NC (KRAX)...GREENVILLE-SPARTANBURG SC
(KGSP)...MORRISTOWN TN (KMRX)...AND CHARLESTON WV (KRLX) WILL
CONTINUE TO PROVIDE COVERAGE OVER PARTS OF THE KFCX AREA DURING
THIS TIME FRAME.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...PH
SHORT TERM...KM
LONG TERM...KK
AVIATION...PH
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
418 PM EDT SUN OCT 7 2012
.SYNOPSIS...
AN AREA OF RAIN WILL MOVE OFFSHORE IN THE NEXT FEW HOURS FOLLOWED
BY ANOTHER BAND OVERNIGHT. THE RAIN SHOULD COME TO AN END IN MOST
LOCATIONS SHORTLY AFTER MIDNIGHT. OTHERWISE...THE MAIN STORY THIS
WEEK WILL BE COOL FALL LIKE WEATHER WITH BELOW NORMAL TEMPERATURES.
A FEW SHOWERS ARE POSSIBLE TUE/WED...BUT A WASHOUT IS NOT
EXPECTED.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
LATEST REGIONAL RADAR MOSAIC SHOWING LIGHT RAIN MOVING ACROSS RI
AND SOUTHEAST MA LATE THIS AFTERNOON. LOOKING FARTHER WEST AROUND
4 PM...WATCHING AN AREA OF LIGHT RAIN BLOSSOMING UNDER THE
INFLUENCE OF A POTENT MID-LEVEL SHORTWAVE. BOTH THE 07/16Z HRRR AND
THE 07/18Z RAP LOOK TO HAVE THE BEST HANDLE ON THE RAINFALL
PATTERN...WHICH NOW LOOKS LIKE WILL COME IN TWO DISTINCT PERIODS.
CURRENT FORECAST POPS FALL INTO THE HIGH POP/LOW RAINFALL AMOUNT
CATEGORY. UPDATED THE RAINFALL TIMING BASED UPON THE 16Z HRRR AND
18Z RAP. CURRENT THINKING IS THE RAIN ACROSS SOUTHEAST MA AND RI
WILL MOVE OFFSHORE EARLY THIS EVENING...RESULTING IN A MAINLY DRY
PERIOD BEFORE A MID-LEVEL SHORTWAVE ARRIVES OVERNIGHT.
ONCE THIS SHORTWAVE PASSES BY...EXPECTING A DRYING AND CLEARING
TREND FROM WEST TO EAST LATE TONIGHT.
TEMPERATURES WERE A BLEND OF THE MAV/MET MOS GUIDANCE. NOT SURE WE
WILL HAVE ENOUGH TIME OF CLEAR SKIES TO GET MUCH FROST. DECIDED
NOT TO ISSUE A FROST ADVISORY AT THIS TIME AS TEMPERATURES ARE NOT
EXPECTED TO GET LOW ENOUGH.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
HIGH PRESSURE SHOULD MOVE ACROSS SOUTHERN NEW ENGLAND MONDAY...AND
REACH A POSITION NEAR NOVA SCOTIA MONDAY NIGHT. LIGHT NORTHWEST
WINDS BECOME LIGHT ONSHORE LATE MONDAY AFTERNOON INTO MONDAY
NIGHT. WELL BELOW NORMAL TEMPERATURES EXPECTED MONDAY DESPITE
PLENTY OF SUNSHINE TO START. INCREASING CLOUDS LATE IN THE DAY
INTO MONDAY NIGHT. LEFT A CHANCE OF RAIN LATE MONDAY NIGHT AS
ANOTHER LOW PRESSURE APPROACHES FROM THE SOUTH. THE CURRENT TIMING
MAY BE A BIT ON THE FAST SIDE.
TEMPERATURES WERE A BLEND OF THE MAV/MET MOS GUIDANCE ONCE AGAIN.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...
* COOL FALL-LIKE WEATHER MOST OF THE WEEK
* CONSIDERABLE CLOUDINESS TUE/WED WITH A FEW SHOWERS POSSIBLE
* STRONG COLD FRONTAL PASSAGES WED NIGHT AND AGAIN FRI
OVERVIEW AND MODEL PREFERENCES...
07/12Z MODEL GUIDANCE SUITE IN FAIRLY GOOD AGREEMENT THROUGH THE
LONG TERM WITH THEIR HANDLING OF THE SYNOPTIC PATTERN. THE LARGE
SCALE IS DEFINED BY A STRONG AND PERSISTENT HUDSON/S BAY VORTEX
WITH WAVE ENERGY WRAPPING THROUGH THE BASE OF ITS LONGWAVE TROF.
THE COMBINATION OF THIS TROF THE THE NW AND AN ATLANTIC RIDGE WILL
YIELD A FAIRLY PERSISTENT WSW JET OVER THE AREA...LEADING TO AN
UNSETTLED PERIOD THROUGH LATE WEEK...AFTER WHICH THE VORTEX WILL
BEGIN TO LIFT N WITH TIME. GIVEN THAT THERE IS REASONABLY GOOD
AGREEMENT BETWEEN THE MODELS...NOT PLANNING ON FAVORING ANY
PARTICULAR MODEL FOR THE BASELINE OF THIS FORECAST.
THEREFORE...WILL BEGIN WITH AN ECMWF/GFS BLEND AND MAKE MANUAL
ADJUSTMENTS FOR BETTER HANDLING OF THE SENSIBLE WX DETAILS.
DETAILS...
TUE INTO WED...
A RIDGE OF HIGH PRES WILL BE MOVING OVER THE AREA THROUGH THE
PERIOD THANKS TO CONFLUENT FLOW ALOFT OVER MUCH OF SRN NEW
ENGLAND. HOWEVER...A CONSTANT SHEAR VORTICITY MAXIMUM WILL ASSIST
IN THE MOVEMENT OF A SFC LOW PRES IN PROXIMITY OF THE 40/70
BENCHMARK THROUGH THE PERIOD. THE BEST LLJ ENERGY...MOISTURE...AND
F-GEN ARE WELL TO THE SW AND CLOSELY ASSOCIATED WITH THE LOW WITH
DRY AIR AND SUBSIDENCE OVER MUCH OF SRN NEW ENGLAND FROM THE HIGH
PRES. WITH MITIGATING FACTORS...IT APPEARS MODELS MAY BE A BIT TOO
ROBUST WITH PRECIP OUTPUT THROUGH THE PERIOD...BUT A FEW SHOWERS
CAN/T BE RULED GIVEN THE DIFFERENTIAL VORTICITY ADVECTION. WILL
GENERALLY CAP POPS AT LOW CHANCE OVER SE PORTIONS OF THE
FA...LOWER POPS TOWARD THE N AND W. MUCH OF THIS PERIOD WILL
LIKELY BE DRY. TUE H85 TEMPS REMAIN AROUND +2C WHILE WED THEY
INCREASE TO NEAR +8C...THEREFORE TEMPS WILL BE IN THE 50S TUE AND
THE 60S WED. MINS WILL LIKELY BE IN THE 40S.
WED EVENING INTO THU...
A STRONG KICKER TROF WILL BE ROTATING THROUGH SRN ONTARIO AND THE
GREAT LAKES. THE SFC REFLECTION IS A STRONG COLD FRONT WHICH WILL
CROSS THE REGION DURING THE OVERNIGHT WED NIGHT. SOUNDINGS SHOW
DECENT MOISTURE LOADING AND THERE ARE FAIRLY GOOD DYNAMICS WITH
THIS SYSTEM...SO WIDESPREAD WET WX IS LIKELY WITH THIS COLD FROPA.
THE FRONT IS CLOSELY ASSOCIATED WITH A 30-40KT LLJ AND H85 TEMPS
COOLING TO NEARLY 0C...SO THERE IS SOME LOW LVL INSTABILITY
POSSIBLE. GIVEN THESE FACTORS CANNOT RULE OUT THE POSSIBILITY OF
BRIEFLY HEAVY RAIN AND A/OR A LOW TOPPED SQUALL LINE ASSOCIATED
WITH THE FRONT ITSELF. THERE IS THE POSSIBILITY IT WILL SLOW
SOMEWHAT AS IT REACHES THE E COAST AS IT GETS WRAPPED UP WITH THE
WEAK LOW PRES OFFSHORE. IN ANY CASE...WET UNSETTLED WX WILL BE
LIKELY WED EVENING INTO THU MORNING...WITH COOL NW FLOW LIKELY
DURING THE DAY THU BEHIND THE FRONT.
FRI AND SAT...
WITH THE KICKER TROF FROM THU HAVING SHIFTED THE PERSISTENT
HUDSON BAY VORTEX FURTHER N AND E...A SE CONUS RIDGE WILL BE
ALLOWED TO SHIFT N WITH ITS ASSOCIATED STRONG HIGH PRES FRI INTO
SAT. THEREFORE DRY COOL WX WILL PREVAIL. MODELS SUGGEST A WEAK
CLIPPER SYSTEM MAY PASS TO THE N EARLY FRI...BUT GIVEN ITS CP
ORIGINS AND PASSAGE WELL TO THE N THIS MAY PASS THE REGION DRY
WITH THE RIDGE CONTINUALLY BUILDING AS IT PASSES.
SUN INTO EARLY NEXT WEEK...
AVAILABLE GUIDANCE SHOWS A VERY STRONG LOW PRES MOVING THROUGH
THE AREA BEGINNING SUN AFTERNOON WITH MORE WET WX POSSIBLE. BOTH
OPNL RUNS OF THE GFS AND ECMWF AS WELL AS MANY OF THEIR
COMPLIMENTARY ENSEMBLE MEMBERS ARE SHOWING THIS...SO CONFIDENCE
INA TRANSITION TOWARD WET WX LATE IN THE WEEKEND AND EARLY NEXT WEEK
IS A HIGHER THAN USUAL CONFIDENCE FORECAST FOR 7 DAYS OUT.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...HIGH CONFIDENCE. EXPECTING PRIMARILY VFR CIGS TONIGHT.
AREAS OF MVFR VSBYS IN HEAVIER RAINFALL. SHOULD LEAD TO DAMP
RUNWAYS AT LEAST. MODERATE CONFIDENCE IN MVFR CIGS ACROSS PORTIONS
OF SOUTHEAST MA AND THE COASTAL WATERS BETWEEN 03Z-09Z. LOW
CONFIDENCE IN IFR CONDITIONS OVERNIGHT. CLEARING FROM WEST TO EAST
AFTER 09/06Z WITH VFR TO PREVAIL MONDAY INTO MONDAY NIGHT.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUESDAY AND WEDNESDAY...LOW TO MODERATE CONFIDENCE.
COMPLEX MIX OF VFR TO MVFR AND IFR WITH LOW PRESSURE MOVING SE OF
THE AREA. BEST CHANCE FOR LOWER CATEGORIES WILL BE IN SHOWERS
PARTICULARLY SE MA/RI TERMINALS.
THURSDAY AND FRIDAY...HIGH CONFIDENCE IN VFR CONDITIONS.
&&
.MARINE...
ISSUED A SMALL CRAFT ADVISORY ACROSS THE OUTER COASTAL WATERS
SOUTH AND EAST OF NANTUCKET DUE TO GUSTY WINDS AND BUILDING SEAS.
ELSEWHERE...EXPECTING RELATIVELY TRANQUIL CONDITIONS OTHER THAN
THE RAINFALL AND OCCASIONALLY LOWER VISIBILITY. COULD SEE ANOTHER
EPISODE FOR MARGINAL SMALL CRAFT ADVISORY CONDITIONS LATE MONDAY
NIGHT.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUE...MODERATE CONFIDENCE.
SCA LIKELY NEEDED FOR INCREASING WINDS 25-30 KT AND HIGH SEAS WITH
LOW PRESSURE OFF THE SE COAST. VSBYS LOWER IN SHOWERS.
WED INTO THU...
SMALL CRAFT CONDITIONS LOWER TUE NIGHT INTO WED WITH A PERIOD OF
QUIET BOATING WEATHER EXPECTED. HOWEVER A STRONG COLD FRONT WILL
APPROACH LATE IN THE DAY WED...CROSSING THE WATERS EARLY THU
MORNING. WINDS WILL INCREASE 25-30 KT BOTH BEFORE AND AFTER THE
COLD FRONTAL PASSAGE. SMALL CRAFT ADVISORIES MAY BE NEEDED...AND
THERE IS THE SLIGHT CHANCE FOR SOME GALE FORCE GUSTS PARTICULARLY
RIGHT AROUND THE TIME OF THE FRONTAL PASSAGE. MODERATE CONFIDENCE.
FRI...
MODERATE CONFIDENCE THAT SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE INTO THE DAY FRIDAY. EVEN THOUGH WINDS MAY SUBSIDE
SOMEWHAT THU NIGHT...THEY WILL PICK UP AGAIN TO 25 KT FRI.
SEAS...PARTICULARLY ON THE OUTER WATERS MAY EXCEED 5 FT DURING THE
PERIOD.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 AM EDT MONDAY
FOR ANZ254-255.
&&
$$
SYNOPSIS...BELK/DOODY
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...DOODY
AVIATION...BELK/DOODY
MARINE...BELK/DOODY
AREA FORECAST DISCUSSION
NWS MIAMI FL
127 PM EDT SUN OCT 7 2012
.AVIATION...
DEEP MOISTURE...LIGHT WINDS...AND UNSTABLE CONDITIONS ACROSS THE
REGION WILL LEAD TO SCATTERED THUNDERSTORMS DEVELOPING AREAWIDE.
STORMS WILL BE SLOW MOVING. MVFR CONDITIONS WILL BE POSSIBLE IN
AND AROUND THUNDERSTORMS. A GULF COAST SEA BREEZE IS EXPECTED TO
DEVELOP BY 19Z AT KAPF...WITH A NW FLOW. LIGHT WINDS ARE EXPECTED
OVERNIGHT...AND SHOWERS MAY BE POSSIBLE NEAR THE EAST COAST TAF
SITES AROUND DAYBREAK.
&&
.PREV DISCUSSION... /ISSUED 921 AM EDT SUN OCT 7 2012/
UPDATE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE ATLANTIC
WATERS MAKING THEIR WAY ONSHORE THE SOUTHEAST FLORIDA COAST THIS
MORNING. WATERSPOUTS ARE POSSIBLE WITH SOME OF THESE
SHOWERS...SIMILAR TO YESTERDAY...AND WILL CONTINUE TO MENTION THIS
IN THE HAZARDOUS WEATHER OUTLOOK FOR TODAY.
MORNING SOUNDING FROM MIAMI SHOWS LITTLE CHANGE FROM YESTERDAY
WITH LOTS OF MOISTURE. THE SOUNDING FROM KEY WEST, HOWEVER, SHOWS A
SUBTLE DRIER LAYER FROM 850 MB TO 700 MB. SHORT RANGE MODELS
INCLUDING THE HRRR AREN`T SHOWING AS MUCH CONVECTION OVER THE
SOUTHERN PENINSULA THIS AFTERNOON COMPARED TO PAST COUPLE OF DAYS.
GLOBAL MODELS (GFS AND ECMWF) SHOW A WEAK MID-LEVEL SHORTWAVE
PASSING THROUGH SOUTH FLORIDA THIS MORNING (POTENTIALLY
CONTRIBUTING TO INCREASED ATLANTIC AND COASTAL CONVECTION THIS MORNING) AND
OVER THE ATLANTIC THIS AFTERNOON. THE DRIER AIR OBSERVED AT KEY
WEST MAY BE AN INDICATION OF SUBSIDENCE BEHIND THE SHORTWAVE AND
MODELS COULD BE PICKING UP ON THIS.
HAVING SAID ALL THIS, STILL EXPECT AT LEAST SCATTERED
SHOWERS/TSTMS OVER INTERIOR AREAS THIS AFTERNOON WITH SLOW
MOVEMENT OF CELLS LEADING TO LOCALLY HIGH RAINFALL AMOUNTS.
HOWEVER, WOULD NOT BE SURPRISED TO SEE LESS ACTIVITY THIS
AFTERNOON AS PER MODEL TRENDS INDICATED ABOVE.
MOLLEDA
PREV DISCUSSION... /ISSUED 727 AM EDT SUN OCT 7 2012/
AVIATION...
CIRRUS CLOUDS COVER MUCH OF THE REGION THIS MORNING...FROM
CONVECTION LAST NIGHT. LIGHT WINDS THIS MORNING WILL BECOME
EASTERLY WITH DIURNAL HEATING LATER TODAY. A WEST COAST SEA BREEZE
IS ALSO EXPECTED TO BECOME ESTABLISHED BY EARLY AFTERNOON. THIS
WILL SET THE STAGE AGAIN FOR SCT TSRAS ACROSS MUCH OF THE SOUTH
FLORIDA AREA...ESPECIALLY ACROSS INTERIOR AREAS. ACTIVITY SHOULD
DIMINISH SHORTLY AFTER NIGHTFALL.
PREV DISCUSSION... /ISSUED 255 AM EDT SUN OCT 7 2012/
SHORT TERM (TODAY-TUESDAY)...
THE LATEST SURFACE ANALYSIS EARLIER THIS MORNING SHOWED A COLD FRONT
EXTENDING SOUTHWEST FROM THE CAROLINAS TO THE CENTRAL GULF COAST
STATES AND WEAK HIGH PRESSURE CENTERED NORTHEAST OF THE LOCAL AREA
OFF THE NERN FLORIDA COAST ACROSS THE WESTERN ATLANTIC. MOIST
EASTERLY LOW-LEVEL FLOW SOUTH OF THIS HIGH WILL PERSIST OVER THE
AREA INTO MONDAY AS THE COLD FRONT GRADUALLY CONTINUES SOUTHEASTWARD
INTO THE STATE AND HIGH PRESSURE BUILDS ACROSS THE REGION IN ITS
WAKE. RECENTLY ANIMATED WATER VAPOR LOOP SHOWED BROAD CYCLONIC FLOW
ACROSS THE MID-SECTION AND EASTERN HALF OF THE COUNTRY CHARACTERIZED
WITH A FAIRLY STRONG SHORTWAVE TROUGH DIGGING SOUTHEAST AND EAST
ACROSS THE PLAINS. MID TO UPPER SW FLOW ALONG WITH PLENTY OF
MID/UPPER MOISTURE AHEAD OF THIS UPPER TROUGH CONTINUES TO STREAM
OVERHEAD. MODEL SOUNDING PROFILES REMAIN FAIRLY WET ACROSS THE
LOCAL AREA THROUGH THE BULK OF THIS SHORT-TERM PERIOD WITH PW`S
REMAINING AROUND THE 2" INCH MARK. ONE MAIN DIFFERENCE OR TREND
NOTED FROM RUN TO RUN WITHIN THE MODELS HAS BEEN THE DECREASE IN
SOUTHWARD PROGRESSION OF THE FRONTAL BOUNDARY INTO OUR LOCAL AREA
OVER THE NEXT COUPLE OF DAYS. THE LATEST MODEL CYCLE INDICATES
THE BOUNDARY STALLING OVER CENTRAL FLORIDA SOMETIME BETWEEN MONDAY
EVENING AND TUESDAY...WHEREAS BEFORE...ALL INDICATIONS INDICATED
THE BOUNDARY PROGRESSING INTO THE AREA WITH DRIER AIR FILTERING IN
BEHIND IT. THIS WILL RESULT IN THE RAIN CHANCES REMAINING IN THE
FORECAST THROUGH THIS PERIOD WITH THE BEST POTENTIAL FOR THE DRIER
AIR LATER THROUGH THE MID/LATTER HALF OF THE WEEK. THE LATEST WRF
MODEL REFLECTIVITIES SUPPORT THIS AND GENERALLY INDICATE THE BULK
OF THE ACTIVITY SETTING UP OVER THE INTERIOR AND GULF COAST
REGIONS THROUGH THE AFTERNOON AND EVENING PERIODS.
HOWEVER...SIMILAR TO YESTERDAY...SCATTERED SHOWERS AND STORMS
DEVELOPING AND SPREADING WEST ACROSS THE EASTERN HALF OF THE AREA
WILL REMAIN POSSIBLE THROUGH THE FIRST HALF OF THE DAY TODAY. THE
LATEST MODEL GUIDANCE INDICATES AN ADDITIONAL HALF OF AN INCH TO
AN INCH ACROSS THE WESTERN HALF OF THE AREA OVER THE UPCOMING FEW
DAYS...WHICH LINES UP WELL WITH THE LATEST HPC GUIDANCE. LOCALLY
HIGHER AMOUNTS WILL REMAIN POSSIBLE WHERE THE ACTIVITY BECOMES
CONCENTRATED THROUGH THIS TIME. AS A RESULT...THE MAIN CONCERNS
WILL BE THE POTENTIAL FOR LOCALIZED FLOODING AND WET
MICROBURSTS/GUSTY WINDS IN AND AROUND THE HEAVIER ACTIVITY OR
STRONG STORMS THAT DEVELOP.
LONG TERM...(TUESDAY NIGHT-SATURDAY)
THE LATEST GFS/GFS ENSEMBLE AND ECMWF REMAIN IN DECENT AGREEMENT ON
THE LARGE SCALE THROUGH THE MID-WEEK PERIOD AND GENERALLY KEEP THE
BROAD CYCLONE FLOW IN PLACE ACROSS THE EASTERN STATES. HOWEVER...ALL
CONTINUE TO SUGGEST MUCH DRIER DEEP LAYER AIR SPREADING SOUTH AS
THE PREVIOUSLY DISCUSSED FRONTAL BOUNDARY STALLS AND DIMINISHES
AND THE MEAN UPPER TROUGH AXIS SHIFTS EWD. THIS DRY AIR WILL
TRANSLATE TO A SLIGHT DECREASE IN DEWPOINTS...POSSIBLY INTO THE
UPPER 60S INLAND AND NORTH AROUND THE LAKE REGION. WILL REFLECT
THIS WITH DECREASING RAINFALL CHANCES THROUGH THIS TIME ACROSS THE
AREA. NO NOTABLE CHANGES REGARDING THE DAILY HIGH AND LOW
TEMPERATURES THROUGH THIS EXTENDED PERIOD.
MARINE...
LIGHT EASTERLY FLOW WILL PERSIST INTO THE UPCOMING WEEK AS A
WEAKENING FRONTAL BOUNDARY APPROACHES FROM THE NORTH AND NORTHWEST.
SCATTERED SHOWERS AND STORMS WILL REMAIN IN THE FORECAST THROUGH
THIS TIME. DRIER AIR WITH LIGHT TO MODERATE NORTHEAST WINDS WILL
BECOME A POSSIBILITY THROUGH THE MIDDLE PART OF THE UPCOMING WEEK.
SEAS WILL RESPOND AND INCREASE INTO THE 3 TO 5 FOOT RANGE ACROSS THE
ATLANTIC WATERS.
FIRE WEATHER...
DESPITE THE DRIER AIR PROGGED TO FILTER INTO THE AREA FROM NORTH TO
SOUTH NEXT WEEK...RELATIVE HUMIDITIES ARE FORECAST TO REMAIN WELL
ABOVE CRITICAL LEVELS WITH NO RED FLAG CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 88 78 89 / 30 40 30 30
FORT LAUDERDALE 79 88 77 88 / 30 40 30 30
MIAMI 78 89 77 89 / 30 40 30 30
NAPLES 75 90 75 89 / 30 40 30 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...59/RM
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
300 PM CDT SUN OCT 7 2012
.DISCUSSION...
ISSUED 300 PM CDT SUN OCT 7 2012
A CHILLY DAY CONTINUES TO UNFOLD ACROSS CENTRAL AND SOUTHEAST
ILLINOIS THIS AFTERNOON...SOON TO BE FOLLOWED BY ONE MORE CHILLY
NIGHT...AS COOL HIGH PRESSURE SETTLES SOUTHEAST ACROSS THE REGION.
ASIDE FROM HOW COLD IT WILL GET TONIGHT...ALONG WITH ANY
FROST/FREEZE POTENTIAL...PRIMARY FORECAST CONCERN TODAY REVOLVES
AROUND PRECIPITATION CHANCES TUESDAY NIGHT AND THURSDAY NIGHT WITH
TWO COLD FRONTAL PASSAGES...AS WELL AS HEADING INTO THE WEEKEND WITH
A MORE VIGOROUS WEATHER SYSTEM.
12Z MODELS REMAIN IN SURPRISINGLY GOOD AGREEMENT FOR MUCH OF THE
WEEK. THEIR AGREEMENT AND RUN-TO-RUN CONSISTENCY HAS BEEN GOOD FOR
MOST OF THE FORECAST PERIOD. HOWEVER...THERE REMAINS SOME
TIMING/STRENGTH DIFFERENCES AND FLIP-FLOPPING WITH THE ARRIVAL UPPER
LOW REMNANTS FROM THE REX BLOCK OFF THE PACIFIC COAST. A ENSEMBLE
MEAN SOLUTION SHOULD CONTINUE TO BE THE BEST OPTION FOR NOW.
SHORT TERM...TONIGHT THROUGH WEDNESDAY...FOR THE FIRST TIME IN A
COUPLE NIGHTS...UNCERTAINTIES WITH CLOUD COVER WILL NOT COMPLICATE
THE OVERNIGHT LOW TEMPERATURE FORECAST. HOWEVER...THE SURFACE RIDGE
AXIS WILL BE SLIDING SOUTHEAST ACROSS THE AREA TONIGHT...WITH WINDS
TURNING SOUTHERLY IN ITS WAKE. THIS SCENARIO SHOULD PRECLUDE
WIDESPREAD FROST/FREEZING CONDITIONS IN THE WESTERN PORTION OF THE
FORECAST AREA. IT WILL BE A CLOSER CALL IN THE EAST WHERE WINDS
WILL BE SLOWER TO TURN SOUTHERLY. SO...HAVE OPTED TO GO WITH A
FROST ADVISORY IN THIS AREA...ALTHOUGH BRIEF/LOCAL FREEZING
CONDITIONS CAN NOT BE RULED OUT.
DEEP SOUTHERLY FLOW WILL GRADUALLY DEVELOP MONDAY INTO TUESDAY AS
THE SURFACE HIGH DRIFTS FURTHER TO THE EAST AND AN UPPER WAVE
DIGGING INTO THE PLAINS HELPS INITIATE DOWNSTREAM RIDGING. THIS
SCENARIO IS SUPPORTIVE OF SLOWLY MODERATING TEMPERATURES...WITH
TEMPERATURES AT OR ABOVE NORMAL BY TUESDAY. THE PATTERN IS ALSO
CONDUCIVE TO DEEP DIURNAL MIXING AND GUSTY WINDS SHOULD DEVELOP
DAILY MONDAY AND TUESDAY.
THE DIGGING WAVE WILL PUSH A FRONTAL BOUNDARY THROUGH THE AREA
TUESDAY NIGHT...ACCOMPANIED BY PRIMARILY POST FRONTAL SHOWERS. THERE
IS GOOD ISENTROPIC ASCENT AHEAD OF THE FRONT...BUT CONDENSATION
PRESSURE DEFICITS SUGGEST THE PRE-FRONTAL AIRMASS WILL BE FAR TOO
DRY TO SUPPORT PRECIPITATION. THERE IS DECENT COUPLED JET FORCING
AND MID-LEVEL FRONTOGENESIS BEHIND THE FRONT AS THE UPPER WAVE MOVES
THROUGH...BUT EXPECTED MOISTURE AVAILABILITY PRECLUDES ME FROM GOING
ABOVE CHANCE POPS AT THIS TIME.
ANOTHER BRIEF SHOT OF QUIET/COOLER WEATHER IS ANTICIPATED BEHIND THE
FRONT FOR WEDNESDAY.
LONG TERM...THURSDAY THROUGH SUNDAY...SOUTHERLY LOW LEVEL FLOW AND
RISING HEIGHTS SIGNAL A RETURN TO MORE SEASONABLE TEMPERATURES FOR
THURSDAY...BEFORE A MOSTLY DRY FRONTAL PASSAGE COOLS THINGS DOWN A
BIT FOR FRIDAY. THEN...ATTENTION TURNS TO THE REMNANTS OF THE UPPER
LOW OFF THE PACIFIC COAST. CONFIDENCE IS GROWING THAT THIS SYSTEM
WILL USHER IN A PERIOD OF WARMER WEATHER...ALONG WITH
SHOWERS/STORMS...AS IT MOVES THROUGH. AS MENTIONED ABOVE...DUE TO
THE REMAINING UNCERTAINTIES REVOLVING AROUND THIS SYSTEM/S
ULTIMATE ARRIVAL...HAVE KEPT POPS IN THE CHANCE CATEGORY.
BAK
&&
.AVIATION...
ISSUED 1208 PM CDT SUN OCT 7 2012
RAPID DIURNAL CLOUD DEVELOPMENT AT 5000 FEET OCCURRED AROUND
15Z...WITH BROKEN CEILINGS NOW WIDESPREAD OVER THE TAF SITES.
ALREADY STARTING TO SEE SOME THINNING OF THE CLOUDS WEST OF
KPIA/KSPI...AND CU-RULE OFF THE RAP MODEL SHOWS CONTINUED
DIMINISHING OF THE CLOUDS FROM WEST TO EAST. BY 00Z...THE
REMAINING CLOUDS SHOULD LARGELY BE SOUTHEAST OF THE TAF SITES.
OVERNIGHT...WEST WINDS WILL GRADUALLY TREND TOWARD THE SOUTHWEST
AND SOUTH AS HIGH PRESSURE PASSES TO OUR SOUTH. WHILE SKIES REMAIN
CLEAR INTO MONDAY...A TIGHTENING PRESSURE GRADIENT WILL LEAD TO
SOME GUSTY SOUTHWEST WINDS BY LATE MORNING...WITH SOME GUSTS ABOVE
15 KNOTS AT MOST SITES.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 1 AM TO 8 AM CDT MONDAY FOR ILZ038-042>046-
051>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1209 PM CDT SUN OCT 7 2012
.DISCUSSION...
ISSUED 1003 AM CDT SUN OCT 7 2012
HIGH PRESSURE WAS CENTERED OVER EASTERN KANSAS LATE THIS
MORNING...RIDGING NORTHEAST INTO WISCONSIN. RAPID CLEARING HAS
BEEN TAKING PLACE OVER MOST OF THE CWA THE LAST COUPLE HOURS...
WITH AREAS FROM ABOUT I-74 NORTHWARD STILL MOSTLY CLOUDY BUT
RAPIDLY CLEARING. SUBSIDENCE FROM THE HIGH SHOULD KEEP SKIES
MOSTLY SUNNY THROUGH THE AFTERNOON...WITH CU-RULE OFF THE NAM AND
RAP MODELS STILL SHOWING SOME DIURNAL DEVELOPMENT ACROSS THE
EASTERN CWA FOR A COUPLE HOURS AROUND MIDDAY.
HAVE SENT SOME UPDATED ZONES/GRIDS TO REFLECT THE SKY TRENDS.
TEMPERATURES LOOKED FAIRLY GOOD AND NO CHANGES MADE TO THE HIGHS.
GEELHART
&&
.AVIATION...
ISSUED 1208 PM CDT SUN OCT 7 2012
RAPID DIURNAL CLOUD DEVELOPMENT AT 5000 FEET OCCURRED AROUND
15Z...WITH BROKEN CEILINGS NOW WIDESPREAD OVER THE TAF SITES.
ALREADY STARTING TO SEE SOME THINNING OF THE CLOUDS WEST OF
KPIA/KSPI...AND CU-RULE OFF THE RAP MODEL SHOWS CONTINUED
DIMINISHING OF THE CLOUDS FROM WEST TO EAST. BY 00Z...THE
REMAINING CLOUDS SHOULD LARGELY BE SOUTHEAST OF THE TAF SITES.
OVERNIGHT...WEST WINDS WILL GRADUALLY TREND TOWARD THE SOUTHWEST
AND SOUTH AS HIGH PRESSURE PASSES TO OUR SOUTH. WHILE SKIES REMAIN
CLEAR INTO MONDAY...A TIGHTENING PRESSURE GRADIENT WILL LEAD TO
SOME GUSTY SOUTHWEST WINDS BY LATE MORNING...WITH SOME GUSTS ABOVE
15 KNOTS AT MOST SITES.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 326 AM CDT SUN OCT 7 2012
THE COLDEST AIR WE WILL SEE WITH THIS AIRMASS WILL MAKE ITS
FARTHEST SOUTHWARD PROGRESSION INTO CENTRAL ILLINOIS THIS MORNING
BETWEEN 12Z AND 18Z...THEN MID LEVEL WARMING WILL DEVELOP AND
CONTINUE UNTIL THE NEXT COLD FRONT ARRIVES TUESDAY NIGHT. WE WILL
HAVE MUCH CLEARER SKIES SUNDAY NIGHT...SO EVEN THOUGH THE COLDEST
AIR WILL HAVE MOVED EAST OF ILLINOIS...FROST/FREEZE POTENTIAL WILL
RETURN FOR AREAS MAINLY EAST OF I-57. THE NEXT RAIN CHANCES WILL
COME WITH COLD FRONTAL PASSAGES ON TUESDAY NIGHT AND THURSDAY
NIGHT...THEN AGAIN WITH A MORE LARGE SCALE LOW PROJECTED TO ARRIVE
EARLY NEXT WEEKEND.
THE OVERALL MODEL GUIDANCE REMAINS IN RELATIVE AGREEMENT ON TIMING
THE MAJOR WEATHER FEATURES...AND A GENERAL BLEND WILL BE
CONTINUED. THERE REMAINS SOME UNCERTAINTY AS TO HOW FAST THE
CUTOFF LOW ON THE WEST COAST WILL EJECT ACROSS THE COUNTRY MID
WEEK AND ARRIVE NEXT WEEKEND. SO WE TEMPERED DOWN THE LIKELY POP
FROM THE ALL-BLEND FOR LATE IN THE EXTENDED.
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT.
LOW CLOUDS HAVE HUNG TOUGH ACROSS THE AREA TONIGHT...KEEPING LOW
TEMPS FROM BOTTOMING OUT AROUND FREEZING IN THE NW. TEMPS IN THAT
AREA ARE STILL DOMINATED BY UPPER 30S AND LOWER 40S AT 08Z...BUT
SOME THINNING TO THE LOW CLOUD DECK MAY OCCUR IN THE FAR WEST BY
SUNRISE. THE LATEST RAP(RUC) GUIDANCE HAS A DECENT HANDLE ON THE
CURRENT CLOUD TRENDS...AND INDICATES A GRADUAL DEPARTURE OF CLOUDS
TODAY. THE NW AREAS SHOULD SEE SOME CLEARING BY NOON...WITH
CLOUDS DISSIPATING IN THE EAST DUE TO MIXING OF DRY AIR FROM
ALOFT AS CLOUDS CONTINUE TO DEPART EASTWARD. THE INCREASING
SUNSHINE WILL STILL HAVE A TOUGH TIME BATTLING THE COLD POOL AND
850MB TEMPS AROUND -3C TO -4C. HIGHS WILL STRUGGLE TO REACH INTO
THE LOWER 50S.
CLEAR SKIES AND LIGHT WINDS WILL BE ESPECIALLY PROMINENT FOR
AREAS EAST OF I-57...CLOSER TO THE DEPARTING COLD POOL.
THEREFORE...THE BETTER CHANCES FOR ANY FROST OR FREEZING
CONDITIONS WILL OCCUR THERE. WE CANT RULE OUT SOME FROST
CONDITIONS FOR OUR FAR NORTHERN COUNTIES /KNOX-STARK-MARSHALL/ BUT
FROST CHANCES WILL BE LOWER IN THE WESTERN AREAS DUE TO A
SOUTHERLY WIND THAT WILL BEGIN TO DEVELOP BY 12Z/7AM MONDAY.
THAT SOUTHERLY RETURN FLOW WILL TRIGGER A WARMING TREND AT THE
SURFACE AND ALOFT UNTIL THE ARRIVAL OF OUR NEXT COLD FRONT TUESDAY
NIGHT. HIGHS ON MONDAY WILL CLIMB INTO THE LOW 60S IN THE
WEST...WITH AROUND 60 IN THE EAST. TUESDAY WILL SEE INCREASING
HIGH CLOUDS LATE IN THE DAY...BUT ENOUGH SUNSHINE SHOULD BE
PRESENT ALONG WITH GUSTY SOUTH WINDS TO BUMP HIGHS INTO THE MID
60S NORTHEAST TO LOW 70S SOUTHWEST.
DESPITE AN ACTIVE FRONTAL CIRCULATION AND ISENTROPIC UPGLIDE WITH
THE FRONTAL PASSAGE TUESDAY NIGHT...MOISTURE LEVELS WILL NOT BE
EXCESSIVELY HIGH. THAT IS NOTED BY THE NAM PRESENTING A DRY FRONTAL
PASSAGE. HOWEVER...THE GFS/GEM/ECMWF ALL HAVE BEEN CONSISTENT WITH
GENERATING SHOWER ACTIVITY IN A MAJORITY OF CENTRAL IL AT SOME
POINT TUES NIGHT. THEREFORE...WE KEPT MID CHANCE POPS GOING.
SHOWERS WILL BE ENDING FROM WEST TO EAST AFTER MIDNIGHT...WITH
EVEN SOME CLEARING WEST OF I-55 BY 12Z/7AM WED.
LONG TERM...WEDNESDAY THROUGH SATURDAY.
A COOLER NORTHWEST FLOW BEHIND THAT COLD FRONT WILL KEEP WEDNESDAYS
HIGHS IN THE UPPER 50S TO AROUND 60. A QUICK REBOUND IN TEMPS IS
EXPECTED FOR THURSDAY AHEAD OF THE NEXT COLD FRONT. BREEZY SOUTH
WINDS AND MID LEVEL WARM AIR ADVECTION WILL HELP BOOST THURSDAYS
HIGHS BACK INTO THE MID 60S.
THURSDAY NIGHT CONTINUES TO BE THE TARGET PERIOD FOR RAIN CHANCES
WITH THE SECOND COLD FRONT THIS WEEK. GULF MOISTURE RETURNING UP
THE MISSISSIPPI RIVER VALLEY WILL FUEL A BAND OF SHOWERS AHEAD OF
THE FRONT. HOWEVER...THE TRACK OF AN UPPER LEVEL SHORTWAVE FROM
WEST TO EAST ACROSS SOUTHERN IL AS THE FRONT ARRIVES MAY KEEP THE
BULK OF THE RAINFALL JUST TO THE SOUTH OF OUR COUNTIES. WE TRENDED
CHANCES POPS FARTHER SOUTH...MAINLY SOUTH OF I-70...WITH SLIGHT
CHANCE POPS UP TO I-72.
FRIDAY SHOULD REMAIN DRY WITH A 1030MB HIGH PASSING ACROSS THE
UPPER MIDWEST. THE ECMWF AND GFS...AS WELL AS THE LAST 24HRS OF
THE 00Z CANADIAN GEM SHOW THE REX BLOCK/CUT-OFF LOW ALONG THE WEST
COAST EJECTING RAPIDLY ACROSS THE COUNTRY STARTING LATE THURSDAY
NIGHT. THE SPEED WITH WHICH THIS FEATURE MOVES ACROSS THE ROCKIES
MAY BE A BIT OVERDONE...SO THE ARRIVAL TIME OF RAIN NEXT WEEKEND
MAY BE DELAYED FROM CURRENT MODEL INDICATIONS. WE KEPT CHANCE POPS
GOING IN THE WEST ON FRIDAY NIGHT AND EVERYWHERE ON SATURDAY...BUT
TEMPERED BACK FROM THE MORE AGGRESSIVE NUMBERS OF THE ALL-BLEND.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 PM EDT SUN OCT 7 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 503 AM EDT SUN OCT 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FULL LATITUDE UPR
TROF OVER ERN NAMERICA...WITH NW FLOW ALF OVER THE UPR GRT LKS. WITH
H85 TEMPS ARND -7C OVER LK SUP /VS WATER TEMPS RANGING FM 6-7C OVER
THE W TO 11-12C OVER THE E/...A WEAK SHRTWV MOVING THRU THE UPR
LKS...AND ADEQUATE LLVL MSTR PER THE 00Z APX RAOB...SOME LK EFFECT
-SHRA MIXED WITH SN CONTINUE OVER MAINLY THE E HALF OF THE LK WHERE
INSTABILITY REMAINS GREATEST. PERSISTENT CNVGC SHOWN BY WIND OBS
OVER THE E HALF OF THE LAKE ARE ALSO HELPING TO MAINTAIN THE
COVERAGE/INTENSITY OF THIS PCPN IN THAT AREA. OVER THE W...MORE ACYC
LLVL FLOW ASSOCIATED WITH SFC RDG EXTENDING FM HI CENTER IN THE
SCNTRL PLAINS TOWARD THE UPR MIDWEST...COOLER WATERS...AS WELL AS
SOMEWHAT DRIER LLVL AIR SHOWN ON THE 00Z INL RAOB ARE CONSPIRING TO
LIMIT THE ACTIVITY OVER THAT PART OF THE LAKE. ALTHOUGH DRIER AIR
OVER THE NRN PLAINS PER THE 00Z BISMARCK RAOB IS SHIFTING TO THE E
IN THE WLY FLOW ON THE NRN FLANK OF THE HI CENTER IN THE SCNTRL
PLAINS...THERE IS A GOOD DEAL OF MID/HI CLD EXTENDING FM ARND LK
WINNIPEG INTO THE NRN PLAINS ASSOCIATED WITH ISENTROPIC ASCENT ON
THE 290-295K SFCS /H7-575/.
TODAY...SHORT TERM MODELS ARE IN GOOD AGREEMENT SHOWING LARGER SCALE
FLOW OVER THE ENTIRE CWA SHIFTING TO THE W AS HI PRES OVER THE
SCNTRL PLAINS SHIFTS TOWARD THE OH RIVER VALLEY...WHICH SHOULD
WEAKEN THE LLVL CNVGC NOW PRESENT OVER THE E HALF AND ADVECT WARMER
H85 TEMPS/DRIER LLVL AIR TO THE W OVER THE CWA. THESE TRENDS WL TEND
TO STEADILY WEAKEN THE ONGOING LK EFFECT PCPN NOW IMPACTING MAINLY
THE E HALF OF THE CWA. THE ARRIVAL OF THE DRIER AIR WL ALSO RESULT
IN MORE SUNSHINE...WHICH WL BE DIMMED AT TIMES BY THE BKN HIER CLDS
DRIFTING INTO THE AREA FM THE NW. MIXING TO H8 ON NAM/GFS FCST SDNGS
YIELDS HI TEMPS MAINLY 45-50...EXCEPT IN THE LO 50S WHERE THE INCRSG
W WIND DOWNSLOPES OVER THE CENTRAL.
SUN NGT...AS NEXT SHRTWV/SFC LO DIGS SEWD THRU SCNTRL CANADA TO NEAR
LK WINNIPEG AND SFC HI PRES SHIFTS INTO THE OH RIVER VALLEY BY
12Z...A STRENGTHENING WSW FLOW WL DVLP OVER THE UPR LKS WITH H925
WINDS INCRSG UP TO 25-35 KTS BY 12Z MON. ALTHOUGH SOME MID/HI CLDS
ASSOCIATED WITH THE ISENTROPIC ASCENT ON THE 290K SFC WL BE OVER THE
UPR LKS...THESE CLDS WL BE RATHER THIN. PWATS AS LO AS 0.25-0.30
INCH INDICATE TEMPS WL STILL FALL FAIRLY SHARPLY OVER THOSE INTERIOR
LOCATIONS ESPECIALLY OVER THE SCNTRL THAT CAN DECOUPLE BEFORE THE
H925 FLOW STRENGTHENS TOO MUCH OVERNGT. LOCATIONS NEAR LK SUP SHOULD
BE WARMEST WITH DOWNSLOPE FLOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 503 AM EDT SUN OCT 7 2012
BY MONDAY MORNING THE UPPER GREAT LAKES WILL BE COMPLETELY WITHIN A
LARGE 500MB TROUGH THAT WILL ENCOMPASS ALL BUT THE FAR SW CORNER OF
THE NATION...EXTENDING FROM THE MAIN LOW OVER N CANADA THROUGH
HUDSON BAY.
FCST MODELS AGREE WITH THE ENHANCEMENT IN THE MAIN THROUGH SET UP
FROM S HUDSON BAY THROUGH CENTRAL SASKATCHEWAN BY MONDAY
AFTERNOON...SHIFTING TO CENTRAL MN BY DAYBREAK TUESDAY...AND SLOWLY
ACROSS LAKE SUPERIOR/UPPER MI TUESDAY. THE APEX OF THE TROUGH SHOULD
BE ACROSS THE CENTER OF THE CWA BY AT 12Z WEDNESDAY...BEFORE PUSHING
TO THE LOWER GREAT LAKES DURING THE DAY.
THE PROGRESSIVELY S SINKING /RUN TO RUN COMPARISON OVER THE PAST
COUPLE OF DAYS/ SFC LOW OVER S MANITOBA AND ND MONDAY MORNING WILL
RESULT IN INCREASED SW WINDS ACROSS THE UPPER GREAT LAKES. THE TRACK
OF THE SFC LOW IS STILL IN QUESTION...WITH THE 06/18Z RUN OF THE GFS
AROUND 6HRS FASTER THAN THE NAM/ECMWF/CANADIAN SOLUTIONS. THE 07/00Z
RUN OF THE GFS IS MUCH FARTHER TO THE N...BUT STILL TRACKING A BIT
FAST. THE TRACK WILL LIKELY BRING THE SFC LOW OVER W-CENTRAL LAKE
SUPERIOR BY 06Z TUESDAY...BEFORE SLIDING NE TO JAMES BAY BY 00Z
WEDNESDAY. GIVEN THIS TRACK...THE STRONGEST WINDS WILL LIKELY BE
AHEAD OF THE SYSTEM /OUT OF THE SW MONDAY THROUGH MONDAY EVENING/.
TEMPERATURE WISE...INCREASED DOWNSLOPE S FLOW WILL BE COUNTERACTED
SLIGHTLY BY ADDITIONAL CLOUD COVER MONDAY AFTERNOON NEAR LAKE
SUPERIOR.
N/NW FLOW WILL RETURN TUESDAY NIGHT BEHIND THE EXITING SFC LOW.
850MB TEMPS OF -5 TO -8C MAY NOT BE ENOUGH TO CREATE MUCH MORE THAN
ENHANCED CLOUD COVER NEAR THE LAKE SUPERIOR SHORELINE TUESDAY NIGHT
INTO WEDNESDAY. HIGH PRESSURE NUDGING IN FROM THE CENTRAL PLAINS
WEDNESDAY SHOULD HELP IN PUSHING MUCH OF THE LOW LEVEL MOISTURE TO
OUR EAST. IT WILL NOT BE QUITE THAT SIMPLE THOUGH...WITH NW FLOW
ALOFT AND A CONTINUATION OF SMALLER SCALE WAVES BRINGING IN
ADDITIONAL MOISTURE.
THURSDAY THROUGH FRIDAY...
YET ANOTHER WAVE LOOKS TO SLIDE IN FROM THE NW THURSDAY OR THURSDAY
NIGHT. THE 06/12Z ECMWF WAS APPROX 12 HRS SLOWER THAN THE 06/18Z RUN
OF THE GFS WITH THIS WEAKER TROUGH. THE 07/00Z RUNS HAVE NEARLY
CORRECTED THIS ISSUE...WITH ONLY MINOR DIFFERENCES. STILL HAVE W TO
NW GALES TO 35KTS POSSIBLE OVER CENTRAL AND E LAKE SUPERIOR THURSDAY
AFTERNOON AND EVENING.
FRIDAY NIGHT THROUGH SATURDAY...
HIGH PRESSURE WILL ATTEMPT TO BUILD IN AT 500MB...WITH LITTLE MORE
THAN ZONAL FLOW BEING THE RESULT...AS THE NEXT LOW NEAR THE
4-CORNERS GETS SWEPT UP IN THE MAIN FLOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 137 PM EDT SUN OCT 7 2012
INTERVALS OF MID/HI CLDS THROUGH MIDDAY MONDAY BUT VFR CONDITIONS WL
PREVAIL AT ALL 3 SITES WITH W WIND ADVECTING DRY LLVL AIR INTO THE
UPR GRT LKS. PLAN ON SOME MARGINAL LLWS CONDITIONS TNGT WITH DVLPG
RADIATION INVRN/DECOUPLING SFC WIND. SOME RAIN SHOWERS ARE EXPECTED
LATER MONDAY AFTERNOON BEYOND THIS TAF PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EDT SUN OCT 7 2012
AS A HI PRES RIDGE BUILDS TOWARD THE OHIO RIVER VALLEY THRU TONIGHT
AND LO PRES MOVES SE THRU CANADA TOWARD MINNESOTA...EXPECT A
STRENGTHENING W WIND OVER LAKE SUPERIOR. AS IS TYPICAL FOR THIS
FLOW...THE STRONGEST WINDS UP TO 30 KTS ARE MOST LIKELY IN THE AREA
BETWEEN THE KEWEENAW AND ISLE ROYALE...WHERE SOME GALE FORCE GUSTS
TO 35 KTS ARE POSSIBLE LATER TODAY.
LOW PRESSURE NEARING FROM SOUTH CENTRAL CANADA WILL RESULT IN
INCREASING SOUTHWESTERLY WINDS MONDAY /WITH S GALES TO 35KTS OVER
PORTIONS OF E LAKE SUPERIOR MONDAY INTO MONDAY EVENING/. EXPECT THE
LOW TO TRACK FROM ND AND SOUTHERN MANITOBA TO W LS BY LATE MONDAY
AFTERNOON INTO MONDAY EVENING. THE LOW WILL PUSH NE TUESDAY...AS
ANOTHER DRYING HIGH PRESSURE SYSTEM ATTEMPTS TO BUILD IN FROM THE
CENTRAL PLAINS. GUSTS WILL DIMINISH TO 20-25KTS TUESDAY NIGHT. YET
ANOTHER LOW SHOULD SKIRT ACROSS OR JUST NORTH OF LAKE SUPERIOR
WEDNESDAY NIGHT...WITH WINDS BRIEFLY INCREASING WITH GUSTS NEARING
30KTS AGAIN WEDNESDAY OUT OF THE NW. HIGH PRESSURE SHOULD FINALLY
WIN OUT TOWARD THE END OF THE WORK WEEK...WITH ANOTHER ROUND OF WEST
TO NORTHWEST GALES TO 35KTS POSSIBLE THURSDAY AFTERNOON AND
EVENING...IN BETWEEN NEARING HIGH PRESSURE TO OUR W AND EXITING LOW
PRESSURE TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ267.
LAKE MICHIGAN...
GALE WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING FOR
LMZ248-250.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...JLA
MARINE...KC/KF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
255 PM EDT SUN OCT 7 2012
.SYNOPSIS...
COOL AND DRY WEATHER IS EXPECTED THROUGH EARLY AFTERNOON. RAIN
WILL OVERSPREAD THE AREA BY LATE TODAY BEFORE ENDING EARLY
TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT AND THIS MAY ALLOW FOR
SOME AREAS OF FROST TO FORM BY EARLY MONDAY MORNING. MOSTLY DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE OUR NEXT SHOT AT
WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
HV UPDATED GRIDS TO RMV POPS ACRS THE FAVORED LK EFFECT LOCATIONS
AS SHOWERS HV WEAKENED RAPIDLY THIS MRNG. HV ALSO RMVD SLGT CHC
POPS OVR THE SE AFT 18Z AS AIRMASS WL LKLY TAKE AWHILE TO SATURATE
DOWN, WITH MAINLY VIRGA EXPECTED BTWN 18Z-21Z. H5 TROF WL APPRCH
FM THE WEST AFT 21Z, RESULTING IN WIDESPREAD PCPN BREAKING OUT
ACRS THE CWA.
HV TWEAKED HRLY T/TD GRIDS TO COME INTO LINE WITH CURRENT OBS. WL
EVALUATE POTENTIAL FOR FROST/FREEZE TONIGHT WITH LATEST MODEL
DATA.
PREVIOUS DISCUSSIONS BLO...
700 AM UPDATE...
THE BAND OF LAKE EFFECT RAIN EAST OF LAKE ONTARIO IS FINALLY
SHOWING A SOUTHWARD PUSH WHILE WEAKENING RAPIDLY. WILL CONFINE
CHANCE POPS TO NORTH CENTRAL ONEIDA COUNTY AND EXTREME NORTHERN
ONONDAGA COUNTY THROUGH 15Z BEFORE KEEPING A DRY FORECAST. A
DEVELOPING AREA OF RAIN OVER SOUTH CENTRAL PA STILL LOOKS TO
SKIRT JUST SOUTHEAST OF OUR CWA BUT STILL FEEL SLIGHT CHANCE POPS
PRUDENT FOR NEPA AS A BUFFER. STILL LOOKING AT THE MAIN THREAT OF
RAIN TO COME AFTER 21Z TODAY WITH THE DISTURBANCE MOVING THROUGH
IL.
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SLIDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AN UNSETTLED EXTENDED TIMEFRAME CONTINUES TO TAKE SHAPE THIS
AFTERNOON AS REGION WILL RESIDE UNDER THE ACTIVE POLAR JET THROUGH
A GOOD PORTION OF THE PERIOD. THAT SAID...EXPECT ONGOING LAKE
EFFECT SHWR ACTIVITY LATE WED/EARLY THU ACROSS THE SOUTHERN TUG
HILL AS REGION WILL RESIDE ON A POST FRONTAL AIRMASS. NEXT
NORTHERN STREAM TROUGH EXPECTED TO DROP SOUTH ACROSS THE AREA THU
NIGHT/EARLY FRI WHICH WILL LEAD TO BELOW NORMAL TEMPS BY FRI AS
COOL CANADIAN HIGH PRESSURE TEMPORARILY SETTLES ACROSS THE REGION.
MODEL PROGGED H85 TEMPS APPROACH -6C BY FRI AFTERNOON AND THUS
EXPECT THE REGENERATION OF LAKE EFFECT SHWRS SOUTHEAST OF LAKE
ONTARIO. BEYOND THIS...STRONG WARM AIR ADVECTION EXPECTED BY THE
BEGINNING OF THE WEEKEND AS CENTRAL PLAINS DISTURBANCE BEGINS
LIFTING NORTH TOWARDS THE CENTRAL GREAT LAKES. FOR NOW...BEST
CHANCES OF WARM ADVECTION SHWRS EXPECTED ON SATURDAY AS WARM FRONT
LIFTS NORTH TOWARDS THE AREA. THE SLOW MOVEMENT OF THE FEATURE MAY
THEN KEEP THE CHANCE FOR SHWRS IN THE FCST THROUGH THE CONCLUSION
OF THE PERIOD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
UPSTREAM RADARS SHOWING AN AREA OF -SHRA ACTIVITY ASSOCIATED WITH
A SHORTWAVE TROUGH HEADING TOWARDS OUR REGION EARLY THIS AFTERNOON.
EXPECT THIS ACTIVITY TO MOVE IN AFTER 20Z WITH ALL TERMINALS
EXPECTED TO FALL TO MVFR THRESHOLDS AS MAIN PRECIP SHIELD PASSES.
SOME POTENTIAL FOR SHORT DURATION IFR CIGS AT BOTH ITH AND BGM AS
THIS ACTIVITY ROLES THROUGH...HOWEVER CONFIDENCE AT THIS TIME IS
NOT HIGH ENOUGH TO INCLUDE IN THE CURRENT FCST. ACTIVITY WILL
QUICKLY EXIT TOWARDS THE NORTHEAST AFTER 02-03Z TIME FRAME WITH
LAKE EFFECT SHWRS THEN EXPECTED TO DEVELOP SOUTHEAST OF LAKE
ONTARIO AFTER 04Z. 280-290 FLOW WILL LIKELY RESULT IN LAKE CLOUDS
AND POSSIBLE SHWR ACTIVITY AT RME...WITH LAKE CLOUDS ALSO POSSIBLE
AT SYR. FURTHER SOUTH...FCST MODELS SUGGEST CLEARING WILL OCCUR
AFTER 06Z AT ELM/BGM/AVP AND POSSIBLY ITH. WITH MOIST LOW-LEVEL
CONDITIONS ASSOCIATED WITH THIS AFTERNOON/S RAINFALL...THE
POTENTIAL EXISTS FOR DEVELOPING IFR CIGS AND VSBYS AFTER 06Z AT
THE ABOVE SITES. BEYOND 13Z...BUILDING HIGH PRESSURE WILL BREAKUP
ANY LINGERING LOW CIGS WITH VFR CONDITIONS EXPECTED THROUGH THE
DURATION OF THE FCST.
OUTLOOK...
MON AFTERNOON/TUE...VFR.
WED...MAINLY VFR WITH POSSIBLE MVFR LATE IN DEVELOPING SHWRS.
THU...MOSTLY VFR WITH POSSIBLE MVFR AT RME IN DEVELOPING LAKE
EFFECT SHWRS.
FRI...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN/PVN
NEAR TERM...HEDEN/PVN
SHORT TERM...HEDEN
LONG TERM...CMG
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
151 PM EDT SUN OCT 7 2012
.SYNOPSIS...
COOL AND DRY WEATHER IS EXPECTED THROUGH EARLY AFTERNOON. RAIN
WILL OVERSPREAD THE AREA BY LATE TODAY BEFORE ENDING EARLY
TONIGHT. OUR SKY WILL CLEAR OUT TONIGHT AND THIS MAY ALLOW FOR
SOME AREAS OF FROST TO FORM BY EARLY MONDAY MORNING. MOSTLY DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY BEFORE OUR NEXT SHOT AT
WIDESPREAD RAIN COMES WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...
HV UPDATED GRIDS TO RMV POPS ACRS THE FAVORED LK EFFECT LOCATIONS
AS SHOWERS HV WEAKENED RAPIDLY THIS MRNG. HV ALSO RMVD SLGT CHC
POPS OVR THE SE AFT 18Z AS AIRMASS WL LKLY TAKE AWHILE TO SATURATE
DOWN, WITH MAINLY VIRGA EXPECTED BTWN 18Z-21Z. H5 TROF WL APPRCH
FM THE WEST AFT 21Z, RESULTING IN WIDESPREAD PCPN BREAKING OUT
ACRS THE CWA.
HV TWEAKED HRLY T/TD GRIDS TO COME INTO LINE WITH CURRENT OBS. WL
EVALUATE POTENTIAL FOR FROST/FREEZE TONIGHT WITH LATEST MODEL
DATA.
PREVIOUS DISCUSSIONS BLO...
700 AM UPDATE...
THE BAND OF LAKE EFFECT RAIN EAST OF LAKE ONTARIO IS FINALLY
SHOWING A SOUTHWARD PUSH WHILE WEAKENING RAPIDLY. WILL CONFINE
CHANCE POPS TO NORTH CENTRAL ONEIDA COUNTY AND EXTREME NORTHERN
ONONDAGA COUNTY THROUGH 15Z BEFORE KEEPING A DRY FORECAST. A
DEVELOPING AREA OF RAIN OVER SOUTH CENTRAL PA STILL LOOKS TO
SKIRT JUST SOUTHEAST OF OUR CWA BUT STILL FEEL SLIGHT CHANCE POPS
PRUDENT FOR NEPA AS A BUFFER. STILL LOOKING AT THE MAIN THREAT OF
RAIN TO COME AFTER 21Z TODAY WITH THE DISTURBANCE MOVING THROUGH
IL.
430 AM UPDATE...
TODAY....A BAND OF LAKE EFFECT RAIN CONTINUES ACROSS CENTRAL OSWEGO COUNTY
AND NORTHERN ONEIDA COUNTY. THE BAND HAS ACTUALLY SHOWN SOME SIGNS
OF BECOMING MORE HEALTHY AND HAS PENETRATED FARTHER INLAND IN JUST
THE LAST HOUR. HIGHER RESOLUTION MODELS SUCH AS THE HRRR AND THE
4KM NAM WHICH WERE DOING WELL WITH THE PLACEMENT OF THE BAND LATE
LAST NIGHT...ARE MUCH TOO WEAK AND TOO FAR SOUTH WITH THE BAND AS
OF 09Z. BASED ON THIS CONTINUED TO KEEP HIGH CHANCE POPS ACROSS
NORTHERN ONEIDA COUNTY THROUGH 12Z...BEFORE GRADUALLY SHOWING A
WEAKENING TREND AS BOUNDARY LAYER WINDS DIMINISH (BAND RETREATS
TOWARD LAKE) AND THE FLOW TURNS MORE INTO THE SOUTHWEST. EXPECT
ACTIVITY TO DIE DOWN COMPLETELY IN OUR AREA BY 15Z.
MEANWHILE FOR THE REST OF US INCREASING HIGH CLOUDS NOW ARE
MORE OF A BARK THEN A BITE FOR OUR AREA WITH A UPPER LEVEL JET
MOVING OVERHEAD NOW...BUT THE BEST LIFT BEING OFF TO OUR SOUTH AND
EAST. KEPT SLIGHT CHANCE POPS IN FOR THE FAR SE CWA IN THE 15Z -
18Z TIME FRAME AS MOST OF THE MODEL GUIDANCE BRINGS POPS INTO INTO
EASTERN PA AND NORTHERN NJ...BUT STAYING SOUTH OF THE REGION. A
MUCH BETTER SHOT AT RAIN...WIDESPREAD FOR A FEW HOURS...WILL COME
WITH A DISTURBANCE IN THE JET STREAM WINDS ALOFT NOW OVER WESTERN
IL. RAIN CHANCES WILL INCREASE RAPIDLY BETWEEN 21Z AND 0Z WITH ALL
BUT AREAS NORTH OF THE THRUWAY IN LIKELY TO CAT POPS...WITH CHANCE
POPS FAR NORTH
TONIGHT...RAIN QUICKLY ENDS BY 03Z ACROSS MOST OF THE CWA WITH
SOME LAKE EFFECT ACTIVITY (RAIN) POSSIBLE AFTER 06Z UP NORTH.
BIGGEST CONCERN HOWEVER IS THE POTENTIAL FOR FROST/FREEZE
CONDITIONS. MAV/MET GUIDANCE IS SHOWING 30 AT KELM AND THIS HAS
BEEN CONSISTENT OVER THE PAST 24 HOURS. DESPITE SUCH COLD MOS
NUMBERS...ELECTED TO HOLD OFF ON ANY ADVISORIES OR WARNINGS
AS CONFIDENCE IS NOT QUITE HIGH ENOUGH AT THE MOMENT. CONCERNS
INCLUDE THE TIMING ON WHEN WE ACTUALLY CLEAR OUT AND WHETHER OR
NOT WE FOG IN OR SEE LOW CLOUDS REDEVELOP GIVEN THE WET GROUND
FROM THE RAIN LATER TODAY. WILL LET THE DAY SHIFT REEVALUATE ON ANY
HEADLINES AND CONTINUE TO HIGHLIGHT IN THE HWO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
430 AM UPDATE...
MONDAY/TUESDAY....HIGH PRESSURE MOVING OUT OF THE OHIO VALLEY
SHOULD KEEP MOST OF THIS PERIOD DRY BUT MODEL TRENDS ARE POINTING
TO SOME UNCERTAINTY STARTING TUESDAY. ANY LAKE SHOWERS EARLY
MONDAY MORNING SHOULD QUICKLY DIMINISH WITH RISING HEIGHTS BY LATE
MORNING. FROST/FREEZE CONDITIONS MAY BE POSSIBLE AGAIN MONDAY
NIGHT...DEPENDING ON THE AMOUNT OF INCREASING CLOUD COVER WE MAY
SEE ESPECIALLY FAR SOUTHEAST.
THE MODELS SHOW ANOTHER AREA OF MOISTURE MOVING THROUGH THE MID-
ATLANTIC STATES...VERY SIMILAR TO WHAT WILL MISS US EARLY
TODAY...LATER MONDAY AND MONDAY NIGHT. AGAIN THE BEST LIFT APPEARS
TO BE JUST SOUTH AND EAST OF US AND WILL KEEP OUR AREA DRY THROUGH
MONDAY NIGHT. AS THIS MOISTURE SLIDES EAST...HIGH PRESSURE
MENTIONED ABOVE WILL MOVE OFF THE COAST OF MAINE. THIS WILL HELP
TO DEVELOP AN ONSHORE FLOW AND WILL BEGIN TO PUSH MOISTURE BACK
TOWARD THE COAST STARTING TUESDAY....ESPECIALLY LATER IN THE DAY.
THE GFS AND EURO HINT AT THIS...BUT KEEP PRECIP MAINLY FROM THE
HUDSON VALLEY SOUTH AND EAST...WHILE THE NAM IS A BIT FARTHER
WEST. FOR NOW WILL PLAY SLIGHT CHANCE POPS TUESDAY FOR LATER IN
THE DAY INTO TUESDAY NIGHT GIVEN THE UNCERTAINTY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
MEDIUM RANGE MODELS MAINTAIN SOME CONSISTENCY WITH INDICATIONS OF
BEST SHOT OF PRECIPITATION ACROSS THE ENTIRE REGION DURING THIS
PERIOD TO BE IN THE WEDNESDAY TIME FRAME. THIS IS THEN LIKELY TO
BE FOLLOWED BY DEEPENING COLD AIR AND A MAINTAINED PRESENCE OF
SHOWER CHANCES TO THE LEE OF LAKE ONTARIO THROUGH THURSDAY WITH
IMPROVED WX OVER THE SOUTHERN HALF. ANOTHER WEAK UPPER TROF AND
SFC FRONT MAY SPREAD A QUICK SHOT OF SHOWERS INTO THE AREA ON
FRIDAY. A FAIRLY LARGE CENTER OF CONTINENTAL POLAR...FALL-
LIKE...HIGH PRESSURE WORKS IN FOR AT LEAST THE FIRST HALF OF NEXT
WEEKEND.
FOLLOWED THE HPC DAY 3-7 GUIDANCE CLOSELY WITH ONLY MINOR LOCAL
ADJUSTMENTS TO TEMPERATURES.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
UPSTREAM RADARS SHOWING AN AREA OF -SHRA ACTIVITY ASSOCIATED WITH
A SHORTWAVE TROUGH HEADING TOWARDS OUR REGION EARLY THIS AFTERNOON.
EXPECT THIS ACTIVITY TO MOVE IN AFTER 20Z WITH ALL TERMINALS
EXPECTED TO FALL TO MVFR THRESHOLDS AS MAIN PRECIP SHIELD PASSES.
SOME POTENTIAL FOR SHORT DURATION IFR CIGS AT BOTH ITH AND BGM AS
THIS ACTIVITY ROLES THROUGH...HOWEVER CONFIDENCE AT THIS TIME IS
NOT HIGH ENOUGH TO INCLUDE IN THE CURRENT FCST. ACTIVITY WILL
QUICKLY EXIT TOWARDS THE NORTHEAST AFTER 02-03Z TIME FRAME WITH
LAKE EFFECT SHWRS THEN EXPECTED TO DEVELOP SOUTHEAST OF LAKE
ONTARIO AFTER 04Z. 280-290 FLOW WILL LIKELY RESULT IN LAKE CLOUDS
AND POSSIBLE SHWR ACTIVITY AT RME...WITH LAKE CLOUDS ALSO POSSIBLE
AT SYR. FURTHER SOUTH...FCST MODELS SUGGEST CLEARING WILL OCCUR
AFTER 06Z AT ELM/BGM/AVP AND POSSIBLY ITH. WITH MOIST LOW-LEVEL
CONDITIONS ASSOCIATED WITH THIS AFTERNOON/S RAINFALL...THE
POTENTIAL EXISTS FOR DEVELOPING IFR CIGS AND VSBYS AFTER 06Z AT
THE ABOVE SITES. BEYOND 13Z...BUILDING HIGH PRESSURE WILL BREAKUP
ANY LINGERING LOW CIGS WITH VFR CONDITIONS EXPECTED THROUGH THE
DURATION OF THE FCST.
OUTLOOK...
MON AFTERNOON/TUE...VFR.
WED...MAINLY VFR WITH POSSIBLE MVFR LATE IN DEVELOPING SHWRS.
THU...MOSTLY VFR WITH POSSIBLE MVFR AT RME IN DEVELOPING LAKE
EFFECT SHWRS.
FRI...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...HEDEN/PVN
NEAR TERM...HEDEN/PVN
SHORT TERM...HEDEN
LONG TERM...JAB
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1257 PM CDT SUN OCT 7 2012
.DISCUSSION...NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING
FORECAST. THE 14Z HRRR CONTINUES TO BE THE MOST AGGRESSIVE MODEL
SHOWING PRECIP ACTIVITY DEVELOPING INITIALLY ALONG THE WARM FRONT
AND MOVING INTO WESTERN NORTH DAKOTA LATER THIS AFTERNOON. THE 12Z
GFS IS BECOMING MORE AGGRESSIVE WITH ITS PROG OF PRECIP WEST.
HOWEVER...IT IS SLOWER WITH ITS PROGRESSION. ON THE OTHER
HAND...THE 12Z NAM IS COMPLETELY DRY WITH ITS PROG AREAWIDE THROUGH
06Z MONDAY. WITH THAT BEING SAID...SIDED WITH A GFS (WHICH IS A
PROXY FOR A MODEL BLEND) TO FORECAST 20 POPS NORTHWEST FROM 21Z-
24Z SUNDAY...THEN EXPANDED SLIGHT CHANCE POPS SOUTH AND EAST FROM
00Z-06Z MONDAY. NO MAJOR IMPACTS ARE EXPECTED. THE UPDATED
GRIDDED AND TEXT PRODUCTS WILL BE OUT SHORTLY.
&&
.AVIATION...LOW PRESSURE OUT OF CANADA WILL BEGIN TO MOVE SOUTH
INTO THE REGION LATE TONIGHT EARLY TOMORROW MORNING. EXPECT SOME
SCATTERED SHOWERS FROM THIS SYSTEM WITH THE BEST CHANCES NORTH AT
SITES ISN AND MOT AFTER 00Z. LOW CEILINGS JUST ABOVE THE MVFR
RANGE WILL MOVE IN FROM NORTH TO SOUTH AROUND 10Z. CEILINGS COULD
GO LOWER INTO THE MVFR CATEGORY. HOWEVER...THIS WILL BE REVISITED IN
LATER TAFS. VFR CONDITIONS ARE EXPECTED THROUGH THE 18Z TAF CYCLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TM...UPDATE
JWS/MM...AVIATION
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
303 PM CDT SUN OCT 7 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
303 PM CDT SUN OCT 7 2012
MAIN FORECAST CONCERNS ARE ON FIRE WEATHER FOR MONDAY AND
PRECIPITATION CHANCES MONDAY NIGHT INTO TUESDAY.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS LOOKS SIMILAR TO YESTERDAY WITH RIDGING OVER THE
NORTHEAST PACIFIC...AND DEEP TROUGHING OVER CENTRAL AND EASTERN
CANADA EXTENDING SOUTH INTO THE CENTRAL PLAINS AND OHIO VALLEY.
THE MAIN FEATURES OF NOTE ARE ON THE WEST SIDE OF THE
TROUGHING...WHICH INCLUDE A WEAK SHORTWAVE TROUGH ENTERING THE
FORECAST AREA NOW...WITH A STRONGER SHORTWAVE IN CENTRAL
SASKATCHEWAN. ONLY A FEW HIGH CLOUDS WERE ACCOMPANYING THE
SHORTWAVE TROUGH CROSSING THE FORECAST AREA. REGARDING THE
SASKATCHEWAN SHORTWAVE... A LARGE EXPANSE OF MID AND HIGH CLOUDS
ENCOMPASSED MUCH OF SASKATCHEWAN. AT THE SURFACE...PRESSURE
GRADIENT HAS TIGHTENED ACROSS THE NORTHERN PLAINS AND THE FORECAST
AREA...AHEAD OF A 1002MB LOW IN CENTRAL SASKATCHEWAN. THE BREEZY
SOUTHWEST WINDS ARE GRADUALLY WARMING THINGS...WITH RAP 850MB
TEMPS AT MPX NOW AROUND 0C COMPARED TO -5C PER 12Z SOUNDING.
AIRMASS QUITE DRY TOO WITH MPX SOUNDING SHOWING 0.18 INCHES OF
PRECIPITABLE WATER OR 30 PERCENT OF NORMAL.
TONIGHT AND MONDAY...MODELS ARE IN MUCH BETTER AGREEMENT HANDLING
THE SHORTWAVE DROPPING DOWN OUT OF SASKATCHEWAN...TRACKING IT TO
NEAR INTERNATIONAL FALLS MN BY 00Z TUESDAY. CO-LOCATED NEARLY RIGHT
UNDERNEATH IT WILL BE THE SURFACE LOW...PROGGED TO DEEPEN
SLIGHTLY...WITH ITS COLD FRONT APPROACHING MINNEAPOLIS AND SIOUX
CITY IOWA AT 00Z TUESDAY. TIGHT PRESSURE GRADIENT FORECAST TO STAY
PUT OVER THE FORECAST AREA THROUGH MONDAY...EXPECTED TO GET EVEN
STRONGER...AS THE FRONT APPROACHES. NOCTURNAL COOLING MAY ALLOW
WINDS TO DIMINISH SOME TONIGHT...ESPECIALLY AT THE TYPICAL COLD
SPOTS...BUT ANTICIPATING BREEZY CONDITIONS TO QUICKLY DEVELOP MONDAY
MORNING WITH THE ONSET OF DIURNAL HEATING. FORECAST SOUNDINGS SHOW
MIXING ANYWHERE FROM 850MB TO 800MB WHERE A WIND CORE OF 35-40 KT IS
PRESENT. THUS GUSTS UPWARDS OF 30 KT ARE POSSIBLE. REGARDING THE
MIXING...IT IS INTERESTING TO SEE THE DEPTH GIVEN WHAT WILL LIKELY
BE A LOT OF CLOUD COVER. 700MB RH FIELDS FROM THE 07.12Z
GFS/NAM/ECMWF/CANADIAN ALL DEPICT THE CURRENT ALTOSTRATUS ACROSS
SASKATCHEWAN SPREADING ACROSS AT LEAST THE NORTHERN 2/3 OF THE
FORECAST AREA DURING THE DAY MONDAY. IN FACT...THE GFS CONTINUES TO
HINT AT EVEN PRECIPITATION FROM TAYLOR COUNTY NORTHWARD COMING OUT
OF THIS MID CLOUD DECK. GIVEN ALL OTHER MODELS DRY AND THE DEEP
MIXING...WILL KEEP A DRY FORECAST GOING. REGARDING HIGH TEMPERATURES
ON MONDAY...THE SOUTHWEST WINDS WILL HELP PROPEL 850MB TEMPS UP TO
4-6C BY 18Z...ALLOWING MOST LOCATIONS TO TOP OUT IN THE 60S. TAYLOR
COUNTY MAY GET STUCK IN THE 50S...THOUGH...DUE TO THICKER CLOUD
COVER PRESENT MUCH OF THE DAY. COMBINATION OF THE WINDS...
TEMPERATURES...ONGOING DROUGHT AND DRY CONDITIONS LEADING TO FIRE
WEATHER CONCERNS. SEE FIRE WEATHER DISCUSSION BELOW. LOWS TONIGHT
SHOULD MAINLY BE IN THE 30S...KEPT UP BY THE WINDS. SOME CONCERN
ABOUT A FROST/FREEZE IN FAR SOUTHWEST WISCONSIN...BUT TEMPERATURES
MAY END UP RIGHT AROUND 32F AND RELATIVE HUMIDITIES DO NOT GET
HIGH ENOUGH TO SUPPORT FROST FORMATION.
MONDAY NIGHT AND TUESDAY...IMMEDIATELY IN THE WAKE OF THE
SASKATCHEWAN SHORTWAVE...MODELS PROG ANOTHER SHORTWAVE WHICH LOOKS
MORE POTENT DROPPING DOWN INTO THE DAKOTAS MONDAY NIGHT...THEN
ENTERING THE WESTERN PORTION OF THE FORECAST AREA ON TUESDAY. THIS
SHORTWAVE IS CURRENTLY IN THE NORTHWEST TERRITORIES. THE SHORTWAVE
LOOKS TO SLOW DOWN THE COLD FRONTAL PASSAGE INITIALLY...SINCE IT
CAUSES THE UPPER FLOW TO TURN PARALLEL. NOT UNTIL TUESDAY DOES THE
FRONT GET A BETTER PUSH EAST ACROSS THE FORECAST AREA...IN RESPONSE
TO THE SHORTWAVE APPROACHING. THUS...MONDAY NIGHT SHOULD STAY
RELATIVELY MILD COMPARED TO WHAT WE HAVE SEEN WITH LOWS IN THE 40S.
BIGGER ISSUE THOUGH IS IF ANY PRECIPITATION CAN OCCUR. THERE IS SOME
LOW TO MID LEVEL FRONTOGENESIS THAT DEVELOPS IN THE WAKE OF THE COLD
FRONT MONDAY NIGHT. HOWEVER...MODELS ARE PRETTY DRY WITH ONLY HINTS
OF A LITTLE LIGHT QPF BETWEEN 06-12Z TUESDAY IN A NARROW BAND. THIS
IS LIKELY DUE TO A COMBINATION OF THE FORCING NOT THAT STRONG AND
PRECIPITABLE WATER VALUES WHICH ARE JUST CLIMBING TO 0.75 OF AN INCH
AT 12Z. TUESDAY IS A DIFFERENT STORY...WITH THE MORE POTENT
SHORTWAVE APPROACHING. THIS SHORTWAVE ENHANCES THE FRONTOGENESIS
CIRCULATION AND NOW THE HIGHER PRECIPITABLE WATER IS IN PLACE. ALL
MODELS DEVELOP A BAND OF LIGHT TO POSSIBLY EVEN MODERATE RAIN BY THE
AFTERNOON ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA. GIVEN
THE POTENCY OF THE SHORTWAVE...THIS CERTAINLY SEEMS POSSIBLE.
THEREFORE...HAVE RAISED PRECIPITATION CHANCES WITH A MAX OF 60 IN
THE SOUTHEASTERN HALF. WITH PLENTY OF CLOUDS...COLD FRONTAL PASSAGE
AND POTENTIAL FOR PRECIPITATION...STAYED ON THE COOLER OF GUIDANCE
FOR HIGHS.
TUESDAY NIGHT AND WEDNESDAY...THE POTENT SHORTWAVE APPROACHING THE
FORECAST AREA AT 00Z WEDNESDAY LOOKS TO MOVE THROUGH FAIRLY
QUICKLY...PERHAPS REACHING LAKE MICHIGAN BY 06Z. THE ENHANCED
FRONTOGENESIS BAND COULD STILL BE OVER THE SOUTHEASTERN 1/3 OF THE
FORECAST AREA IN THE EVENING...AS SUGGESTED BY THE 07.00Z ECMWF...
SO HAVE MAINTAINED A 20-30 PERCENT CHANCE OF PRECIPITATION. AFTER
THAT...STRONG SUBSIDENCE AND DRYING COMES IN ALOFT...WHICH MAY TRAP
SOME LOW CLOUDS ALONG/EAST OF THE MISSISSIPPI RIVER. SURFACE RIDGE
AXIS STILL WELL TO THE WEST TUESDAY NIGHT...ONLY REACHING WESTERN
MINNESOTA BY 12Z WEDNESDAY...FAVORING TOO THE CLOUDS TO STAY IN
PLACE. COMBINATION OF DAYTIME MIXING AND THE SURFACE RIDGE AXIS
CROSSING THE AREA ON WEDNESDAY WILL HELP TO DISSIPATE THE CLOUDS.
HAVE INCREASED CLOUD COVER BUT MAY NEED FURTHER INCREASES...
PARTICULARLY IN WISCONSIN WHICH IS MORE IN CYCLONIC LOW LEVEL FLOW.
850MB TEMPS DROP QUITE A BIT ON TUESDAY NIGHT...FALLING FROM 0-4C AT
00Z TO -2 TO -4C AT 12Z. HOWEVER...A NORTHERLY BREEZE ON THE EAST
SIDE OF THE RIDGE AXIS PLUS CLOUDS MAY END UP HOLDING TEMPERATURES
UP HIGHER THAN GUIDANCE. AS SUCH...LEANED A LITTLE WARMER THAN WHAT
GUIDANCE SHOWED WITH LOWS MAINLY IN THE LOW 30S.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
303 PM CDT SUN OCT 7 2012
07.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT
ON THE PATTERN CHANGE FORECAST THE PAST FEW DAYS. ONE MORE SHORTWAVE
TROUGH IS FORECAST TO DROP DOWN THROUGH THE DEEP TROUGHING...
CROSSING LAKE SUPERIOR ON THURSDAY. THIS SHORTWAVE TROUGH AND
ASSOCIATED COLD FRONT LOOK TO COME THROUGH DRY...WITH YET ANOTHER
CANADIAN HIGH PRESSURE AREA BUILDING IN FOR FRIDAY. AFTER THAT...THE
RIDGING OVER THE NORTHEAST PACIFIC...AS WELL AS AN UPPER LOW
CURRENTLY OFF THE CALIFORNIA COAST...GET PUSHED TO THE EAST. MODEL
HANDLING YESTERDAY WAS PROBLEMATIC WITH THE UPPER LOW...BUT NOW ALL
MODELS ARE IN SYNC IN LIFTING IT OUT OF THE SOUTHWESTERN U.S. INTO
NEBRASKA BY 12Z SATURDAY. STRONG 850MB MOISTURE TRANSPORT IS
INDICATED AHEAD OF THE UPPER LOW...WHICH SHOULD RESULT IN WIDESPREAD
RAIN/SHOWER DEVELOPMENT UPSTREAM TOWARDS THE FORECAST AREA. IN
FACT...THERE ARE EVEN SIGNALS OF A COUPLED UPPER JET STRUCTURE TO
SET UP OVER THE FORECAST AREA. BEST CHANCES OF PRECIPITATION ARE ON
SATURDAY AS THE UPPER LOW AND THE ASSOCIATED LOW PRESSURE SYSTEM
LIFT INTO IOWA. HAVE ALSO INCLUDED A MENTION OF THUNDER ON
SATURDAY...MAINLY SOUTH OF I-90...WHERE 850MB TEMPS ARE CLIMBING
TOWARDS 10-12C AND MUCAPE VALUES TOP OUT BETWEEN 200-500 J/KG.
CHANCES OF PRECIPITATION CONTINUE THROUGH SUNDAY...WITH THOSE ON
SATURDAY NIGHT RELATED TO DEFORMATION ON THE BACK SIDE OF THE
SURFACE LOW PASSING TO OUR SOUTH...THEN WITH A POSSIBLE SHORTWAVE
DROPPING DOWN OUT OF CANADA IN THE WAKE OF THE UPPER LOW.
TEMPERATURES OVERALL THROUGH MUCH OF THE LONG TERM PERIOD EXPECTED
TO STAY BELOW NORMAL...EVEN WITH THAT WARMER AIR COMING UP ON
SATURDAY. THE PROBLEM WITH SATURDAY IS THERE WILL LIKELY BE A LOT OF
CLOUDS AND THE RAIN AROUND. FOLLOWED THE CONSENSUS WHICH RESULTS IN
HIGHS IN THE 50S. COLDEST NIGHT LOOKS TO BE THURSDAY NIGHT AS THAT
CANADIAN HIGH BUILDS ALMOST OVERHEAD BY 12Z FRIDAY. LOWS AT OR BELOW
FREEZING ARE LIKELY.
&&
.AVIATION...THROUGH 18Z MONDAY
1222 PM CDT SUN OCT 7 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. WINDS
WILL BE ON THE INCREASE LATE TONIGHT INTO MONDAY A SURFACE TROUGH
APPROACHES FROM THE DAKOTAS. LOW LEVEL WIND SHEAR IS POSSIBLE LATE
TONIGHT INTO EARLY MONDAY MORNING IF SURFACE WINDS DECOUPLE. AT
THIS TIME IT APPEARS THAT SOUTHWEST WINDS AT THE SURFACE WILL STAY
IN THE 8 TO 13 KT RANGE THROUGH THE NIGHT AT KLSE AND IN THE 10 TO
15 KT RANGE AT KRST. FORECAST SOUNDINGS SHOW SOUTHWEST WINDS
INCREASING TO AROUND 42 KTS AT 1500 FT. WITH SURFACE WINDS STAYING
UP IT APPEARS THAT WE WILL FALL JUST SHORT OF LOW LEVEL WIND
SHEAR CRITERIA SO HAVE NOT INCLUDED IT IN THE TAFS AT THIS TIME. WILL
HAVE TO KEEP A CLOSE EYE ON SURFACE WINDS OVERNIGHT. CLOUDS WILL
INCREASE LATE TONIGHT INTO MONDAY MORNING...AND BY MONDAY MORNING
A BROKEN MID CLOUD DECK WILL BE IN PLACE WITH CLOUD BASES AROUND
9KFT. LOOK FOR THE BREEZY SOUTHWEST WINDS TO CONTINUE MONDAY WITH
SPEED OF 15 TO 20 KTS...GUSTING INTO THE 25 TO 30 KT RANGE AT
TIMES.
&&
.FIRE WEATHER...MONDAY
327 PM CDT SUN OCT 7 2012
A BREEZY SOUTH WIND TONIGHT...ESPECIALLY WEST OF THE MISSISSIPPI
RIVER...WILL HELP PREVENT FULL RELATIVE HUMIDITY RECOVERY TONIGHT
GIVEN DEWPOINTS RIGHT NOW IN THE TEENS. MAXIMUM RELATIVE HUMDITY
VALUES ARE ONLY EXPECTED TO TOP OUT BETWEEN 60-70 PERCENT AT MOST.
THE BREEZY SOUTH TO SOUTHWEST WINDS ARE EXPECTED TO PERSIST INTO
THE DAY MONDAY AS LOW PRESSURE DROPS INTO NORTHERN MINNESOTA.
SUSTAINED SPEEDS OF 15 TO 25 MPH ARE LIKELY WITH GUSTS OF 30 TO 35
MPH. PLENTY OF CLOUDS ASSOCIATED WITH THE LOW PRESSURE AREA SHOULD
OVERSPREAD THE AREA...ESPECIALLY ALONG AND NORTH OF I-90. THIS
RESULTS IN SOME ISSUES...PRIMARILY WITH FINE FUELS. HOWEVER...WITH
TEMPERATURES WARMING UP INTO THE 60S AND RELATIVE HUMIDITIES
DROPPING INTO THE 20-25 PERCENT RANGE WEST OF THE MISSISSIPPI
RIVER...VERY CONCERNED ABOUT FIRES. THE ONGOING MODERATE TO
EXTREME DROUGHT PLUS MOST OF THE REGION EXPERIENCING A FREEZE ALSO
CREATES EXTRA CONCERN FOR FIRES. AFTER COORDINATION WITH MINNESOTA
AND IOWA FIRE WEATHER OFFICIALS...HAVE ISSUED A FIRE WEATHER WATCH
FOR LOCATIONS WEST OF THE MISSISSIPPI RIVER. EAST OF THE
MISSISSIPPI RIVER...MINIMUM RELATIVE HUMIDITIES ONLY DROP TO 25-30
PERCENT. WINDS ARE SLIGHTLY LIGHTER AND TEMPERATURES ARE COOLER.
AFTER COORDINATION WITH WISCONSIN FIRE WEATHER OFFICIALS...HAVE
DECLINED TO ISSUE ANY FIRE WEATHER WATCH EAST OF THE MISSISSIPPI
RIVER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
303 PM CDT SUN OCT 7 2012
WI...NONE.
MN...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR MNZ079-086>088-094>096.
IA...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
FIRE WEATHER...AJ