Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/26/12
AREA FORECAST DISCUSSION...UPDATED
NWS TUCSON AZ
1135 AM MST MON SEP 24 2012
.SYNOPSIS...A COOLING TREND WILL OCCUR THIS WEEK AS HIGH PRESSURE
ALOFT WEAKENS. THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
THIS AFTERNOON AND THIS EVENING. THERE IS A SLIGHT CHANCE OF SHOWERS
ACROSS THE WHITE MOUNTAINS TUESDAY. PRECIPITATION CHANCES WILL
INCREASE LATER THIS WEEK AND THIS WEEKEND AS SUBTROPICAL MOISTURE
MOVES INTO THE AREA.
&&
.UPDATE...HAVE INCLUDED A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS WRN PIMA COUNTY THIS AFTERNOON. 24/12Z UNIV OF AZ NAM/GFS WRF
AS WELL AS THE 24/15Z RUC HRRR DEPICT PRECIP ECHOES TO OCCUR MOSTLY
BETWEEN 2030Z-2300Z ACROSS WRN PIMA COUNTY. SLIGHT CHANCE OF SHOWERS/
THUNDERSTORMS ELSEWHERE THIS AFTERNOON AS PER THE DISCUSSION SECTION
BELOW.
&&
.DISCUSSION...SATELLITE IMAGERY AND SURFACE OBSERVATIONS INDICATE
MOSTLY SUNNY SKIES FROM TUCSON EWD/SWD AT THIS TIME. PARTLY CLOUDY
SKIES WERE NOTED FROM WRN PIMA COUNTY NEWD TO THE WHITE MOUNTAINS.
DEWPOINTS VALID 16Z RANGED FROM THE 30S ACROSS THE WHITE MOUNTAINS
TO THE MID 50S F ACROSS WRN PIMA COUNTY. THESE TEMPS WERE GENERALLY
ABOUT 5-10 DEGS F HIGHER VERSUS 24 HOURS AGO. SURFACE TEMPS VALID
16Z WERE NEARLY 2-5 DEGS F LOWER VERSUS THIS TIME SUN.
24/12Z KTWC SOUNDING DEPICTED AN INCREASE IN MOISTURE IN THE
SURFACE-700 MB LAYER VERSUS 24 HOURS AGO. THE COLUMN WAS NEARLY
SATURATED IN THE 600-500 MB LAYER. HOWEVER...FAIRLY STABLE 12Z
REGIME WITH LIFTED INDEX OF PLUS 1 AND VERY MINIMAL CAPE. 24/12Z
UPPER AIR PLOTS INDICATED 571 DM LOW CENTERED OVER NWRN NEVADA AND
N-S RIDGE AXIS OVER THE CENTRAL CONUS PLAINS. LIGHT-MODERATE SWLY
FLOW ALOFT PREVAILED OVER SE AZ.
BASED ON INCREASING LOWER-LEVEL MOISTURE...DIFFLUENT FLOW ALOFT IN
ADVANCE OF THE NEVADA LOW PRESSURE SYSTEM...AND THE 24/12Z NAM AND
24/09Z SREF SOLUTIONS...OPTED TO INCLUDE A SLIGHT CHANCE OF SHOWERS
AND THUNDERSTORMS FROM TUCSON EWD/SWD THIS AFTERNOON AND THIS
EVENING. GIVEN THE FAIRLY DRY NEAR-SURFACE ENVIRONMENT TO OCCUR...
QPF/S SHOULD BE QUITE LIGHT. THE PROSPECT FOR MEASURABLE PRECIP WILL
END BY MIDNIGHT TONIGHT.
TUE-WED...
THERE IS ENOUGH MOISTURE FOR A SLIGHT CHANCE OF SHOWERS AND TSTMS
ACROSS THE WHITE MOUNTAINS TUE. ZONAL FLOW ALOFT TO THEN PROVIDE DRY
CONDITIONS AREA-WIDE WED.
THUR-FRI...
INCREASING SWLY FLOW ALOFT TO OCCUR AS BROAD UPPER LOW DEVELOPS WELL
OFF THE SRN CALIFORNIA/NRN BAJA CALIFORNIA COASTS. ALSO...SOME
MOISTURE FROM TROPICAL SYSTEM MIRIAM IS PROGGED TO ADVECT INTO SE AZ
THIS PERIOD. THE OFFICIAL FORECAST WILL CONTINUE WITH A SLIGHT
CHANCE OF SHOWERS/TSTMS ACROSS ERN SECTIONS THUR...THEN FROM TUCSON
EWD/SWD FRI. PRECIP-FREE CONDITIONS WEST OF TUCSON THIS PERIOD.
SAT-SUN...
MARKEDLY DEEPER MOISTURE IS PROGGED ACROSS THE AREA THIS WEEKEND.
24/00Z ECWMF ALSO DEPICTS PRONOUNCED DIFFLUENCE ALOFT IN ADVANCE OF
CLOSED UPPER LOW JUST OFF THE NRN BAJA CALIFORNIA COAST. THE
OFFICIAL FORECAST DEPICTS SLIGHT CHANCE CATEGORY...OR LOW-END CHANCE
CATEGORY POPS THIS WEEKEND.
A COOLING TREND WILL START TODAY AND CONTINUE INTO THIS WEEKEND.
&&
.AVIATION...ISOLD-SCT -TSRA/-SHRA FROM KTUS EWD/SWD THIS AFTERNOON
AND THIS EVENING. OTHERWISE...FEW-BKN CLOUDS MOSTLY AT 6-10K FT AGL
THRU TUESDAY MORNING OR 25/12Z. SURFACE WIND GENERALLY LESS THAN 10
KTS THRU TUESDAY MORNING EXCEPT WLY 8-18 KTS WITH GUSTS TO 25 KTS
THIS AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THERE IS A SLIGHT CHANCE OF THUNDERSTORMS FROM
TUCSON EASTWARD AND SOUTHWARD THIS AFTERNOON AND THIS EVENING. THERE
IS A SLIGHT CHANCE OF THUNDERSTORMS ACROSS THE WHITE MOUNTAINS
TUESDAY. DEEPER MOISTURE IS FORECAST TO INCREASE LATER THIS WEEK AND
THIS WEEKEND...FOR AN IMPROVED CHANCE OF SHOWERS AND THUNDERSTORMS.
LIGHT DIURNAL WINDS WILL OCCUR THIS WEEK EXCEPT FOR SOME BREEZES
THIS AFTERNOON AND TUESDAY AS A LOW PRESSURE SYSTEM MOVES NORTH OF
THE AREA.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS DENVER CO
846 AM MDT MON SEP 24 2012
.UPDATE...HAVE UPDATED THE GRIDS THIS MORNING TO INCLUDE ISOLATED
RAIN SHOWERS FROM THE FRONT RANGE FOOTHILLS AND NORTHEAST PLAINS.
WEAK DISTURBANCE BRUSHING ACROSS NORTHERN COLORADO WITH WEAK MID
LEVEL QG ASCENT ON THE LATEST RUC ANALYSIS. OTHERWISE...REST OF
THE FORECAST LOOKS GOOD.
&&
.AVIATION...UPDATED THE FCST AND TAFS THIS MORNING TO MENTION
ISOLATED RAIN SHOWERS THROUGH 20Z. ALTHOUGH SFC WINDS SWLY AT THIS
TIME...A BOUNDARY ON RADAR SHOULD MOVING ACROSS WRN ADAMS COUNTY
SHOULD ALLOW ALLOW FOR SFC WINDS TO BECOME WEST TO NORTHWESTERLY
AROUND 15Z. ALSO EXPECT BKN CIGS 8-10 KFT AGL TO CONTINUE INTO
THE AFTERNOON AS WELL WITH PLENTY OF MID LEVEL MOISTURE UPSTREAM.
&&
.PREV DISCUSSION... /ISSUED 437 AM MDT MON SEP 24 2012/
SHORT TERM...MOISTURE AT MID AND UPPER LEVELS HAS INCREASED OVER
THE STATE DOWNSTREAM FROM A WEAKENING UPPER LOW OVER THE GREAT
BASIN. WITH THE MOUNTAINS UNDER THE DEFORMATION ZONE THIS
AFTERNOON...SCATTERED SHOWER ACTIVITY WILL BE POSSIBLE. A FEW
SHOWERS MAY THEN SPREAD ONTO THE PLAINS DURING THE EVENING. CAPE
VALUES FROM MODEL SOUNDINGS ARE VERY LOW...BUT WE CAN NOT RULE OUT
A FEW EMBEDDED THUNDERSTORMS DURING THE AFTERNOON AND EVENING
HOURS. DYNAMIC FORCING OVER THE STATE WILL BE VERY WEAK...SO
RAINFALL INTENSITIES ARE EXPECTED TO REMAIN LIGHT. THE BETTER
CHANCES FOR PRECIPITATION OVER THE FORECAST AREA WILL WAIT UNTIL
TUESDAY WHEN THE UPPER LOW GETS CLOSER TO US...BUT FOR NOW WE NEED
TO MENTION ISOLATED TO SCATTERED SHOWERS FOR THIS AFTERNOON AND
EVENING. TEMPERATURES ACROSS THE FORECAST AREA ARE GOING TO BE
SOME 5-10 DEGREES COOLER THAN YESTERDAY...BUT STILL ABOVE SEASONAL
NORMALS.
LONG TERM...AN UPPER LEVEL LOW WILL BE OVER UTAH ON TUE AND THEN
SLOWLY MOVE EASTWARD AND WEAKEN OVER COLORADO ON WED. THERE WILL
BE A CONSIDERABLE AMOUNT OF MID LVL MOISTURE WITH THIS SYSTEM AS
LOW LEVEL MOISTURE GRADUALLY INCREASES OVER THE PLAINS. THUS
SHOULD SEE A BETTER CHC OF SHOWERS AND THUNDERSTORMS ON TUE. AT
THIS TIME HARD TO SAY HOW STG STORMS WILL BE AS ABUNDANT MID LVL
CLOUD COVER COULD INHIBIT HEATING AND KEEP OVERALL INSTABILITY
SOMEWHAT LIMITED IN MOST AREAS. OVERALL MID LVL FLOW WILL BE
RATHER WEAK SO STORMS WILL BE SLOW MOVING AND COULD PRODUCE SOME
HEAVY RAIN IF THERE IS BETTER HEATING ESPECIALLY OVER THE NERN PLAINS.
AS FOR HIGHS FOR NOW WILL KEEP READINGS IN THE LOWER TO MID 70S
ACROSS NERN CO HOWEVER IF CLOUD COVER IS ABUNDANT THEN READINGS
COULD UP BEING A FEW DEGREES COOLER.
FOR TUE NIGHT INTO WED THE UPPER LEVEL LOW WILL WEAKEN AS A WEAK UPPER
LEVEL TROUGH WILL LINGER OVER THE AREA. DEEPER LOW LVL MOISTURE
WILL FLOW INTO NERN CO IN SELY LOW LVL FLOW THUS COULD SEE QUITE A
BIT OF STRATUS IN THE MORNING. SHOULD SEE ANOTHER CHC OF SHOWERS
AND THUNDERSTORMS DURING THE DAY AS CONVECTIVE TEMPS ARE FAIRLY
LOW. WITH THE MID LVL FLOW WEAK AND PRECIPITABLE WATER VALUES
NEARING AN INCH COULD SEE SOME LOCALLY HEAVY RAIN WITH STORMS OVER
THE PLAINS. WITH COOLER MID LVL TEMPS WILL PROABLY SEE SOME SNOW
ABV 10000 FEET TUE NIGHT INTO WED IN THE MTNS.
BY THU THE FLOW ALOFT WILL BE WK NWLY AS THE REMNANTS OF THE UPPER
LEVEL TROUGH TRACK EAST OF THE AREA. HOWEVER THERE STILL WILL BE
QUITE A BIT OF MOISTURE LINGERING OVER THE AREA WITH COOL MID LVL
TEMPS. THUS BY AFTN MAY SEE A CHC OF SHOWERS AND TSTMS IN THE MTNS
WITH AT LEAST A SLIGHT CHC AT LOWER ELEVATIONS. WILL KEEP HIGHS
NEAR SEASONAL NORMALS.
FOR FRI THERE ARE SOME MINOR DIFFERENCES BETWEEN THE ECMWF AND GFS
AS THE GFS HAS WK WLY FLOW ALOFT OVER THE AREA WHILE THE ECMWF HAS
MORE OF A SWLY COMPONENT WITH ANOTHER WK UPPER LEVEL TROUGH
APPROACHING FM THE NW. HOWEVER BOTH MODELS STILL SHOW QUITE A BIT
OF MOISTURE OVER THE AREA WITH SOME DECENT INSTABILITY SO SHOULD
SEE AT LEAST A SLIGHT CHC OF AFTN AND EARLY EVENING TSTMS IN MOST
AREA. 850-700 MB TEMPS RISE A FEW DEGREES ON FRI SO WILL HAVE
HIGHS IN THE 75 TO 80 DEGREE RANGE ACROSS NER NCO.
BY SAT THE ECMWF SHOW A WEAK UPPER LEVEL TROUGH MOVING ACROSS THE
AREA WITH A BETTER CHC OF SHOWERS AND TSTMS WHILE THE GFS HAS WK
WNW FLOW ALOFT AND A DRIER AIRMASS. AS A RESULT THE GFS HAS VERY
LITTLE PCPN. THIS FAR OUT HARD TO SAY WHICH SOLUTION IS THE BEST.
AS FOR TEMPS NATURALLY IF THE ECMWF IS RIGHT HIGHS WOULD BE COOLER
ON SAT WHILE THE GFS WOULD HAVE SIMILAR HIGHS TO FRI. FOR NOW WILL
KEEP FCST CLOSER TO THE GFS AND LET DAY SHIFT MAKE ADJUSTMENTS IF
NEEDED.
AVIATION...CEILINGS SHOULD REMAIN HIGH THROUGH MOST OF THE DAY.
IT IS POSSIBLE THAT CEILINGS COULD DROP TO 5000-6000 FT AGL LATE
IN THE AFTERNOON AND DURING THE EVENING AS AREAS OF RAIN SHOWERS
DEVELOP. THE AIRMASS WILL ONLY BE SLIGHTLY UNSTABLE...SO THE
THREAT OF THUNDERSTORMS WILL BE MINIMAL...BUT ONE OR TWO MAY POP
UP...MAINLY OVER THE MOUNTAINS. WINDS SHOULD BE LIGHT MOST OF THE
DAY...BUT SOME GUSTS MAY OCCUR ASSOCIATED WITH THE EVENING SHOWER
ACTIVITY.
HYDROLOGY...ANY RAIN SHOWERS THAT DEVELOP THIS AFTERNOON SHOULD
ONLY PRODUCE LIGHT AMOUNTS OF RAINFALL. NO HYDROLOGIC ISSUES ARE
EXPECTED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM....RPK
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS ALBANY NY
1110 PM EDT TUE SEP 25 2012
.SYNOPSIS...
A COLD FRONT WILL BRING SOME SHOWERS AND A SLIGHT CHANCE
OF THUNDERSTORMS TO THE REGION TONIGHT INTO TOMORROW. HIGH PRESSURE
AND DRY WEATHER WILL BRIEFLY BUILD BACK INTO THE REGION FOR
THURSDAY...BEFORE ANOTHER STORM SYSTEM AFFECTS MAINLY SOUTHEASTERN
PARTS OF THE REGION WITH A CHANCE OF RAIN FOR THURSDAY NIGHT INTO
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 10 PM...SHOWERS HAVE DEVELOPED WITHIN THE REGION OF INCREASING
ISENTROPIC LIFT. THE CURRENT POP GRIDS WERE SLIGHTLY
REFRESHED...OTHERWISE...THE FORECAST REMAINS IN EXCELLENT SHAPE.
AS OF 7 PM...INCREASING HIGH AND MID LEVEL CLOUDS ACROSS THE
REGION AND THETA-E ADVECTION IS UNDERWAY. HOWEVER...REGIONAL
RADARS REVEAL A BAND OF SHOWERS ALONG THE I80 CORRIDOR WITH
ANOTHER BAND OF CONVECTION JUST NORTH OF THE OHIO RIVER. THIS WILL
COMPLICATE FACTORS OVERNIGHT WITH RESPECT TO THE ONSET OF SHOWERS
AND THE COMBINATION OF UPSTREAM CONVECTION DISRUPTING MOISTURE
TRANSPORT INTO THE REGION AND THE LEAD WAVE TRACKING ALONG OR JUST
SOUTH OF THE NY/PA BORDER. LATEST RAP/RUC AND HRRR SUGGEST THE
THETA-E ADVECTION AND ISENTROPIC LIFT WILL INCREASE TO RESULT IN
LOWERING OF THE CPD/S AND SHOWERS TO DEVELOP WELL AFTER MIDNIGHT.
FOR THIS UPDATE...NO CHANGES TO THE POPS BUT THAT COULD CHANGE
ONCE WE HAVE 00Z RAOBS. MINOR CHANGES TO THE HOURLY FORECASTS AND
SKY COVER.
AS OF 430 PM EDT...A FRONTAL BOUNDARY WAS SITUATED ACROSS THE
GREAT LAKES...WITH THE ASSOCIATED UPPER LEVEL TROUGH DIVING SOUTH
OF CANADA. AT THE SAME TIME...AN MCS WAS MOVING PORTIONS OF OHIO
VALLEY/CENTRAL APPALACHIANS. THIS MCS WILL STAY PLENTY FAR SOUTH
TO AVOID ANY DIRECT IMPACT ON OUR AREA...ALTHOUGH IT MAY ACTUALLY
ROB SOME MOISTURE FROM HEADING INTO THE COLD FRONT.
WE SHOULD STAY DRY FOR MUCH OF THE EVENING WITH INCREASING AMOUNTS
OF MID AND HIGH LEVEL CLOUDINESS. AFTER MIDNIGHT...THERE WILL BE A
CHANCE OF SHOWERS FROM WEST TO EAST. A PERIOD OF SHOWERS IS LIKELY
TOWARDS DAYBREAK...DUE TO INCREASING AMOUNTS OF WARM AIR
ADVECTION/ISENTROPIC LIFT.
MIN TEMPS OVERNIGHT WILL RANGE FROM THE MID 40S TO MID 50S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
THE FIRST WAVE OF SHOWERS ASSOCIATED WITH THE ISENTROPIC LIFT WILL
END BY THE MID MORNING OR SO. AS THE FRONT CONTINUES TO SLIDE
EASTWARD TOWARDS WESTERN NY...ANOTHER BATCH OF SHOWERS WILL OCCUR
FOR THE AFTERNOON INTO THE EVENING HOURS WITH THE SFC FRONTAL
BOUNDARY ITSELF. SKIES SHOULD REMAIN MOSTLY CLOUDY FOR MUCH OF THE
DAY...ALTHOUGH THERE COULD BE A FEW BREAKS IN THE CLOUDS AFTER THE
INITIAL BATCH OF RAIN. WITH THIS SECOND BATCH OF RAIN...THE NAM
SHOWS SMALL AMOUNTS OF SFC BASED INSTABILITY. WE WILL ALLOW FOR
SOME THUNDER...SINCE THERE MAY BE A RUMBLE OR TWO OF THUNDER IN
THESE. WITH THE VERY LOW AMOUNTS OF INSTABILITY...AND POOR LOW/MID
LEVEL LAPSE RATES...THERE ARE NO CONCERNS FOR ANY STRONG STORMS.
MAX TEMPS ON WEDNESDAY WILL BE AROUND THE UPPER 60S TO LOW 70S.
SHOWERS WILL END DURING THE EVENING HOURS ON WEDNESDAY WITH THE
PASSAGE OF THE COLD FRONT. MIN TEMPS WILL RANGE FROM THE UPPER 30S
IN THE DACKS TO THE MID 50S IN THE MID HUDSON VALLEY. TOTAL QPF
LOOKS TO BE AROUND A QUARTER TO THIRD OF AN INCH FOR MOST AREAS.
HIGH TERRAIN AREAS COULD SEE ABOUT A HALF INCH OF RAINFALL...ESP
IN THE SRN DACKS.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR THURSDAY AS THE COLD
FRONT FROM WEDNESDAY STALLS OVER THE MID ATLANTIC STATES. THIS SHOULD
ALLOW FOR DRY CONDITIONS WITH A GOOD DEAL OF SUNSHINE. MAX TEMPS
IN VALLEY AREAS WILL GENERALLY BE IN THE 60S WITH LIGHT SFC WINDS.
A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE STALLED FRONTAL
BOUNDARY OVER THE MID ATLANTIC FOR THURSDAY NIGHT INTO FRIDAY.
THIS STORM WILL MOVE UP THE NORTHEASTERN SEABOARD...BRINGING A
SWATH OF RAIN FOR SOUTHEASTERN PARTS OF THE AREA FOR LATE THURSDAY
NIGHT INTO FRIDAY. IT MAY STAY CLEAR ENOUGH FOR PARTS OF THE
ADIRONDACKS THURSDAY NIGHT FOR SOME FROST FORMATION BEFORE THE
CLOUDS MOVE IN UP THERE FOR FRIDAY. MIN TEMPS THURSDAY NIGHT WILL
RANGE FROM THE MID 30S IN THE CENTRAL DACKS TO NEAR 50 IN THE MID
HUDSON VALLEY. MAX TEMPS ON FRIDAY WILL BE IN THE 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SERIES OF WEAK DISTURBANCES ALONG A QUASI-STATIONARY FRONT ACROSS
PORTIONS OF THE SOUTHERN U.S. WILL PROVIDE PERIODS OF SHOWERS FOR
THE WEEKEND...WITH IMPROVING CONDITIONS BY TUESDAY AS WEAK HIGH
PRESSURE REPLACES THE COLD FRONT SLIDING OFF THE EASTERN SEABOARD.
IN GENERAL...THE BEST CHANCES FOR SIGNIFICANT PRECIPITATION IS
FRIDAY NIGHT WHEN LOW PRESSURE ALONG THE FRONT TRACKS EAST ACROSS
THE MID-ATLANTIC.
TEMPERATURES WILL WARM FROM HIGHS FROM THE MID 50S TO LOWER 60S ON
SATURDAY...TO THE 60S TO AROUND 70 BY TUESDAY. OVERNIGHT LOWS WILL
REMAIN FAIRLY CONSISTENT DURING THE PERIOD...WITH READINGS BOTTOMING
OUT FROM MAINLY THE MID AND UPPER 40S...TO THE LOWER AND MID 50S.
NORMAL HIGHS FOR ALBANY DURING THIS PERIOD ARE IN THE MID AND UPPER
60S...WITH NORMAL LOWS IN THE MID 40S.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
VFR CONDITIONS TO CONTINUE THROUGH THE REST OF THIS EVENING AND
INTO THE EARLY PORTIONS OF THE OVERNIGHT PERIOD...WITH A
DIMINISHING TREND IN BOTH VIS/CIGS AS SHOWER POTENTIAL INCREASES.
A SHORTWAVE TROUGH WILL CONTINUE TO ROTATE CLOSER TO THE REGION
DURING THE OVERNIGHT HOURS ALLOWING INCREASED MOISTURE AND LIFT TO
PROMOTE BROKEN AND EVENTUALLY OVERCAST CEILINGS AFT 06Z AT ALL TAF
SITES. THIS SHORTWAVE TROUGH WILL ACCOMPANY AN INCREASING MOIST
ISENTROPIC LIFT AHEAD OF THE FRONT WILL PROMOTE THE ONSET OF SHOWERS
BETWEEN 08Z AND 10Z...AND MVFR CEILINGS AND BORDERLINE MVFR
VISIBILITIES AT ALL TAF SITES. CONFIDENCE IN FOG DEVELOPMENT REMAINS
LOW AT THIS TIME WITH LOW TEMPERATURES ONLY REACHING WET BULB ZERO
VALUES AND GRADIENT WINDS INHIBITING BOUNDARY LAYER DECOUPLING FOR
FOG DEVELOPMENT TO COMMENCE.
SHOWERS ARE EXPECTED TO DECREASE IN COVERAGE DURING THE DAYLIGHT
HOURS ON WEDNESDAY WITH A RENEWED THREAT FOR ADDITIONAL SHOWERS
THROUGH THE DAY. FOR NOW...WE WILL PLACE VCSH AND AWAIT FUTURE
TRENDS AS EXPECTATIONS THAT MVFR THRESHOLDS COULD BE SATISFIED.
WINDS WILL BE LIGHT THROUGH WEDNESDAY OUT OF THE SOUTH-SOUTHWEST
AT 5-12 KTS AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
SYSTEM.
OUTLOOK...
THU-FRI...VFR. CHC MVFR KPOU W/CHC SHWRS ON FRI.
SAT-SUN...MAINLY VFR. CHC -SHRA.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT FEW DAYS. A
FRONTAL BOUNDARY WILL BRING A WETTING RAIN TO THE REGION FOR TONIGHT
INTO TOMORROW. RH VALUES WILL BE NEAR 100 PERCENT TONIGHT. RH VALUES
WILL ONLY DROP TO 60-70 PERCENT TOMORROW...WITH VALUES BACK TO NEAR
100 PERCENT TOMORROW NIGHT. RH VALUES WILL DROP TO NEAR 40 PERCENT
ON THURSDAY AFTERNOON.
SOUTHERLY WINDS OF 5-10 MPH ARE EXPECTED TONIGHT INTO
TOMORROW. WINDS WILL SWITCH TO A NW DIRECTION FOR TOMORROW NIGHT
INTO THURSDAY AT SIMILAR SPEEDS.
&&
.HYDROLOGY...
A FRONTAL BOUNDARY WILL SPREAD SOME RAIN SHOWERS ACROSS THE REGION
FOR TONIGHT INTO TOMORROW...WITH SHOWERS ENDING FROM NORTHWEST TO
SOUTHEAST ON WEDNESDAY EVENING. THERE WILL LIKELY BE TWO MAIN WAVES
OF SHOWERS...WITH ONE PERIOD LATE TONIGHT INTO TOMORROW
MORNING...AND THE NEXT BATCH LATER TOMORROW AFTERNOON INTO TOMORROW
EVENING. BASIN AVERAGE RAINFALL FROM THESE SHOWERS WILL BE AROUND A
THIRD OF AN INCH...ALTHOUGH A FEW SPOTS IN THE HIGHER ELEVATIONS MAY
SEE UP TO A HALF INCH OF RAIN. THIS RAINFALL SHOULD ONLY ALLOW FOR
SMALL RISES ON AREA RIVERS AND STREAMS.
ANOTHER STORM SYSTEM MAY AFFECT SOUTHEASTERN PORTIONS OF THE REGION
FOR THURSDAY NIGHT INTO FRIDAY...WITH UNSETTLED WEATHER POSSIBLY
CONTINUING INTO THE WEEKEND AS WELL. THE MODELS ARE HAVING
DIFFICULTY AGREEING ON EXACTLY HOW MUCH PRECIPITATION OCCURS THROUGH
THIS PERIOD...AS IT WILL DEPEND ON IF THE WEEKEND SYSTEM CUTS OFF
AND LINGERS OVER OUR AREA. ALTHOUGH WIDESPREAD FLOODING ISN/T
EXPECTED AT THIS TIME...WE WILL NEED TO CONTINUE TO MONITOR MODEL
TRENDS OVER THE NEXT FEW DAYS.
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.
&&
.EQUIPMENT...
THE KENX DOPPLER RADAR WILL BE UNDERGOING REPAIRS AS ADDITIONAL
PARTS ARE ON ORDER. THE KENX RADAR WILL CONTINUE TO BE DOWN AND IS
EXPECTED TO BE BACK IN SERVICE BY MID AFTERNOON ON WEDNESDAY
SEPTEMBER 26TH 2012. WE APOLOGIZE FOR ANY INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/BGM
SHORT TERM...FRUGIS
LONG TERM...ELH
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
EQUIPMENT...BGM/BJF
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1002 PM EDT TUE SEP 25 2012
.SYNOPSIS...
A COLD FRONT WILL BRING A ROUND OF TWO OF SCATTERED SHOWERS WED AND
WED NIGHT...BUT A WASHOUT IS NOT EXPECTED. A BRIEF PERIOD OF HIGH
PRESSURE IS EXPECTED FOR THURSDAY INTO THURSDAY NIGHT AS THE COLD
FRONT MOVES OFFSHORE AND DRIER AIR MOVES IN. BUT BEGINNING EARLY
FRIDAY A WARM FRONT WILL LIFT NORTH AS LOW PRESSURE DEEPENS OVER THE
GREAT LAKES REGION. SHOWERS...HEAVY AT TIMES...WILL CONTINUE THROUGH
THE WEEKEND INTO EARLY NEXT WEEK. HIGH PRESSURE RETURNS BY TUESDAY
INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
10 PM UPDATE...
MAIN CHANGE TO FORECAST IS BASED ON CURRENT POSITION OF SHOWERS
PER REGIONAL RADAR AND EXPECTED TRANSIT TIME PER MOVEMENT. WE HAVE
REDUCED OVERNIGHT POPS AND DELAYED THEIR APPEARANCE IN WESTERN
PARTS OF OUR AREA UNTIL MORNING. ANY SHOWERS SHOULD BE LIGHT.
REMAINDER OF FORECAST HAS ONLY MINOR CHANGES BASED ON OBSERVED
DATA AND LATEST GLAMP AND HRRR DATA. LOOKS LIKE A QUIET NIGHT WITH
SOME INCREASE IN MID AND HIGH CLOUDS. TEMPS AND DEWPOINTS ARE
MOSTLY IN LINE WITH FORECAST...THE BIGGEST DIFFERENCE IS AT KEENE
AIRPORT WHICH WAS 6 DEGREES COOLER THAN THE FORECAST AT 00Z.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...
A BAND OF AT LEAST SCATTERED SHOWERS WILL SWEEP ACROSS THE REGION
FROM WEST TO EAST THROUGH THE MID AFTERNOON HOURS. THIS A RESULT OF
AN INSTABILITY BURST IN THE WARM AIR ADVECTION PATTERN. SOME
UNCERTAINTY ON THE AREAL COVERAGE...BUT DID INCLUDE HIGHER POPS IN
OUR NORTHERN/WESTERN ZONES WHERE THE BETTER DYNAMICS RESIDE.
REGARDLESS NOT EXPECTING A TOTAL WASHOUT...AND A GOOD PORTION OF THE
DAY WILL PROBABLY END UP DRY ESPECIALLY FROM MID AFTERNOON ONWARD.
THIS A RESULT OF THE FIRST BATCH OF PRECIPITATION MOVING OFF THE
COAST. LEFT THUNDER OUT DURING THE DAYLIGHT HOURS...ALTHOUGH CAN/T
RULE OUT AN ISOLATED RUMBLE HERE OR THERE...FELT IF THIS EVEN OCCURS
AREAL COVERAGE WOULD BE QUITE LIMITED.
IT WILL BE QUITE BREEZY TO EVEN WINDY AT TIMES AS A STRONG LOW LEVEL
JET SHOULD YIELD SOUTHWEST WIND GUSTS OF 25 TO 35 MPH DURING THE
AFTERNOON. WE SHOULD SEE A CONSIDERABLE AMOUNT OF CLOUDINESS...BUT
A FEW PEEKS OF SUNSHINE WILL BE POSSIBLE AT TIMES. GIVEN THE
EXCELLENT MIXING EVEN WITH AN ABUNDANCE OF CLOUD COVER...HIGH TEMPS
WILL STILL LIKELY RECOVER INTO THE LOWER TO MIDDLE 70S IN MOST
LOCALES.
SURF...GIVEN THE STRONG WINDS THERE WILL BE AN ELEVATED RISK FOR
DANGEROUS RIP CURRENTS ACROSS MANY OF OUR OCEAN EXPOSED BEACHES.
THERE IS A LOW PROBABILITY THAT A HIGH SURF ADVISORY MAY BE NEEDED
FOR PORTIONS OF THE SOUTH COAST/CAPE/ISLANDS...BUT CONFIDENCE WAS
NOT HIGH ENOUGH TO ISSUE AT THIS POINT.
WEDNESDAY NIGHT...
IT APPEARS THAT A SECOND ROUND OF SCATTERED SHOWERS WILL AFFECT THE
REGION IN ASSOCIATION WITH THE SURFACE COLD FRONT. AGAIN...SOME
UNCERTAINTY ON THE AREAL COVERAGE BUT IT DOES APPEAR THAT BETTER
FOCUS/ORGANIZATION FOR THIS SECOND ROUND OF PRECIPITATION WILL BE
NEAR THE SOUTH COAST. THIS AREA HAS BETTER INSTABILITY/MOISTURE FOR
THE ACTIVITY TO BECOME MORE WIDESPREAD...SO INCLUDED SOME LIKELY
POPS IN THIS REGION. ALSO...WITH MARGINALLY ELEVATED INSTABILITY
DID INCLUDE A RISK FOR ISOLATED THUNDER BUT NOT EXPECTING ANYTHING
WIDESPREAD.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
MODEL ANALYSIS...
A CHALLENGING FCST AS SOLNS DIFFER ON HANDLING BIFURCATING SHRTWV
ENERGY INTO THE WEEKEND ACROSS THE GRT LKS RGN. AM NOT FULLY
UNDERSTANDING WHY ENERGY SEPARATES FROM THE LONGWAVE PATTERN...BUT
THERE ARE A COMBINATION OF SIGNALS SUCH AS A WEAK SHRTWV THRU THE
MID-ATLANTIC...A SHORT-TERM REX BLOCK PATTERN COUPLED WITH ENHANCED
RIDGING AHEAD OF THE BIFURCATED LOW...AND A CONTINUED NEGATIVE NAO/
AO PATTERN KEEPING A STRONG RIDGE OF HIGH PRES THRU THE ATLANTIC...
BLOCKING THE LONGWAVE FLOW PATTERN. OVERALL THE BIFURCATED LOW
SHOULD MOVE TOWARDS LOWERING HEIGHTS AHEAD OF THE SHORT-TERM REX
BLOCK AND THE MID-ATLANTIC SHRTWV...THUS DISASSOCIATING IT FROM THE
LONGWAVE PATTERN.
TURNING ATTENTION TOWARDS COMPARING SOLNS...THE 25/12Z NAM AND 25/0Z
GEFS HAVE ALIGNED FAIRLY WELL WITH THE 25/0Z ECMWF OUT TO 0Z SAT.
CANADIAN HAS WOBBLED CONSIDERABLY ILLUSTRATING POOR RUN-TO-RUN
CONSISTENCY AND WILL NOT BE CONSIDERED. ALL ENCOMPASSING WILL TREND
THE FCST MORE TOWARDS THE 25/0Z AND 24/12Z ECMWF...INCLUDING THE
25/12Z NAM...LESSER OF THE 25/12Z GFS AS IT REMAINS AN OUTLIER
/THOUGH IT IS SHOWING IMPROVEMENT TOWARDS THE ECMWF/.
DETAILS...
THURSDAY INTO THURSDAY NIGHT...
SFC COLD FRNT SHOULD BE OFFSHORE BY MORNING WITH ATTENDANT SHOWERS.
MAY REMAIN WET ACROSS THE ADJACENT S/SE WATERS FOR THE MORNING INTO
MIDDAY PD. HIGH PRES WITH COOLER AND DRIER AIR SHOULD MOVE IN.
ANTICIPATING CLEARING CONDITIONS WITH THE MIX-DOWN OF DRIER AIR TO
THE SFC /WITH PERHAPS SOME W-NW GUSTY WINDS AROUND 15 MPH/.
FEEL HIGH PRES WILL CONTROL THE WX INTO FRI MORN AND WILL GO WITH A
DRY FCST /PERHAPS SOME SLGT CHC POPS FOR THE S CT VLY/. A WEAK
SHRTWV THRU THE LONGWAVE PATTERN SHOULD INVOKE A WEAK LOW PRES
CENTER ACROSS THE MID-ATLANTIC. ATTENDANT DYNAMICS WILL BEGIN TO
LIFT THE OFFSHORE STALLED FRONTAL BOUNDARY AS A WARM FRNT. NLY SFC
FLOW SHOULD BEGIN TO REVERT MORE E/NELY. THE SUBSEQUENT COOLER
AIRMASS ALOFT SHOULD ALLOW FOR MINS INTO THE 40S...BUT LIMITED IN
FALLING FURTHER BY INCREASING CLOUDS AHEAD OF THE AFOREMENTIONED
SYSTEM.
FRIDAY...
AS THE WEAK SFC LOW LIFTS NEWD THRU THE ERN GRT LKS RGN...THE
ATTENDANT WARM FRNT BECOMES THE FOCUS OF DEEP LYR ASCENT /LEFT-EXIT
RGN OF AN UPR LVL JET/ AND ISENTROPIC LIFT OF SUB-TROPICAL MOISTURE
RESULTING OF A BAND OF RAIN LIFTING THRU S CT. CHC TO LIKELY POPS
ARE WARRANTED. A COOL AND WET DAY EXPECTED. E/SELY ONSHORE SFC FLOW
BECOMING BRISK IN RESPONSE TO LOW PRES. THUNDER CHCS APPEAR LIMITED.
FRIDAY NIGHT THROUGH MONDAY NIGHT...
NOT LOOKING GOOD FOR THE WEEKEND. AFOREMENTIONED BIFURCATED LOW
RETROGRADES INTO THE GRT LKS RGN AMPLIFYING A S/SWLY FETCH OF SUB-
TROPICAL FLOW THRU THE LOW-MID LVLS. THE EXPECTATION IS FOR
ADDITIONAL WEAK SHRTWV IMPULSES TO ROTATE AROUND THE BIFURCATED LOW
PROVIDING ENHANCED ASCENT OF SUB-TROPICAL MOISTURE COUPLED WITH
PREVAILING ISENTROPIC LIFT. REMAINING MOSTLY CLOUDY...EXPECTING
ROUNDS OF SHOWERS ACROSS THE RGN /SOME OF WHICH MAY BE HEAVY AT
TIMES/. THE EXACT TIMING OF SHRTWV ENERGY IMPULSES REMAINS
UNCERTAIN...BUT COULD SEE THE HEAVIEST RAINS SAT NGT INTO SUNDAY.
TUESDAY AND BEYOND...
A FIRST GUESS...COOLER AND DRIER HIGH PRES BUILDS INTO THE RGN. ITS
PROGRESSION EWD AND OFFSHORE GRADUALLY RESULTS IN THE RETURN OF MORE
SEASONABLE CONDITIONS.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
SHORT TERM...
MODERATE TO HIGH CONFIDENCE. VFR PREVAILS ASIDE FROM SOME PATCHY
FOG IN NRN VALLEY LOCALES. WITH THE ONCOMING WX...LOW CONFIDENCE
ON MVFR CIGS BUT WILL BE MONITORING CLOSELY. EXPECT AN INITIAL
BAND OF SHRA AROUND MIDDAY WED /LOW CONFIDENCE TSRA/ WITH A SECOND
BAND DURING THE EVNG PD TOWARDS MIDNIGHT. SOME SHRA MAY BE HEAVY
RESULTING IN INTERMITTENT VSBY IMPACTS. BIGGEST THREAT IS
INCREASING S/SWLY WINDS GUSTING UP TO 35 KTS ACROSS THE CAPE AND
ADJACENT SE MA COASTAL PLAIN ALONG AND AHEAD OF A SFC COLD FRNT
WHICH SHOULD MOVE OFFSHORE BY THURS MORN. STRONGEST OF WINDS
SHOULD OCCUR BETWEEN MIDDAY INTO EVNG WEDNESDAY.
KBOS TAF...MODERATE TO HIGH CONFIDENCE.
PREVAILING VFR WITH INCREASING WINDS INTO THE WEDNESDAY MIDDAY-
AFTN PD. LOW CONFIDENCE ON MVFR AND TSRA. MIDDAY SHRA...A BRIEF
DRY PD...THEN A RETURN OF SHRA LATE.
KBDL TAF...MODERATE TO HIGH CONFIDENCE.
PREVAILING VFR WITH INCREASING WINDS INTO THE WEDNESDAY MIDDAY-
AFTN PD. SHOULD SEE SHRA INTO THE LATE MORNING HRS CONTINUING INTO
AFTN. ANOTHER ROUND EXPECTED AFTER DUSK. LOW CONFIDENCE MVFR CIGS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY INTO THURSDAY NIGHT...MODERATE CONFIDENCE. CIGS LIFTING
WITH DEPARTING SYS. BECOMING MOSTLY CLEAR. NWLY WINDS PREVAIL WITH
GUSTS UP TO 15 KTS DIMINISHING OVRNGT. WILL SEE CLOUDS ON THE
INCREASE INTO FRI MORN LOWERING WITH TIME OVER THE S CT VLY.
FRIDAY INTO SUNDAY...MODERATE CONFIDENCE.
MIX OF VFR/MVFR CIGS WITH -RA BR. MAY SEE RA/+RA AT TIMES WITH IFR
IMPLICATIONS. E/SELY FLOW.
&&
.MARINE...
HIGH CONFIDENCE THROUGH WEDNESDAY NIGHT. SOUTHWEST WIND GUSTS OF 25
KNOTS SHOULD DIMINISH THIS EVENING...AT LEAST ACROSS THE NEAR SHORE
LOCATIONS WITH THE LOSS OF DAYTIME HEATING. HOWEVER...DEVELOPING
LOW LEVEL JET WILL RESULT IN STRONG SCA WIND GUSTS OF 25 TO 30
KNOTS BY LATE WED MORNING/AFTERNOON ESPECIALLY NEAR SHORE. LOW
PROBABILITY THAT A FEW LOCATIONS ALONG THE SOUTH COAST COULD BRIEFLY
TOUCH GALE FORCE WIND GUSTS. SCA HOISTED ALL WATERS THROUGH LATE
AFTERNOON WEDNESDAY. WINDS SHOULD DIMINISH WEDNESDAY
EVENING...BUT LEFT OVER SWELL WILL RESULT IN 5 FOOT OR GREATER SEAS
CONTINUING ACROSS THE OUTER-WATERS THROUGH WEDNESDAY NIGHT.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY...MODERATE CONFIDENCE.
SHOWERS LINGER ALONG THE S/SE WATERS AS A COLD FRNT EXITS OFFSHORE.
CLEARING INTO AFTN AND EVNG. N/NWLY FLOW GUSTS AT TIMES UP AROUND 20
KTS PSBL DURING THE DAY...QUIET OVRNGT. WAVES UP TO 5 FT TO LINGER
ALONG THE OUTER WATERS INTO DUSK.
FRIDAY INTO SUNDAY...MODERATE CONFIDENCE.
SHOWERS WILL PLAGUE THE WATERS WITH E/SELY FLOW WHICH MAY BECOME
STRONG AT TIMES WITH GUSTS OF 15-20 KTS. IT IS PLAUSIBLE TO SEE 5 FT
SEAS BUILDING BACK INTO THE S/SE WATERS SHOULD WINDS REMAIN
SUSTAINED FOR A LONG PERIOD OF TIME.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT WEDNESDAY FOR ANZ231>237-
250-251.
SMALL CRAFT ADVISORY FROM 11 AM TO 6 PM EDT WEDNESDAY FOR
ANZ230.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT THURSDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...FRANK/SIPPRELL
NEAR TERM...WTB/FRANK/SIPPRELL
SHORT TERM...FRANK
LONG TERM...SIPPRELL
AVIATION...FRANK/SIPPRELL
MARINE...FRANK/SIPPRELL
AREA FORECAST DISCUSSION
NWS ALBANY NY
735 PM EDT TUE SEP 25 2012
.SYNOPSIS...
A COLD FRONT WILL BRING SOME SHOWERS AND A SLIGHT CHANCE
OF THUNDERSTORMS TO THE REGION TONIGHT INTO TOMORROW. HIGH PRESSURE
AND DRY WEATHER WILL BRIEFLY BUILD BACK INTO THE REGION FOR
THURSDAY...BEFORE ANOTHER STORM SYSTEM AFFECTS MAINLY SOUTHEASTERN
PARTS OF THE REGION WITH A CHANCE OF RAIN FOR THURSDAY NIGHT INTO
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 7 PM...INCREASING HIGH AND MID LEVEL CLOUDS ACROSS THE
REGION AND THETA-E ADVECTION IS UNDERWAY. HOWEVER...REGIONAL
RADARS REVEAL A BAND OF SHOWERS ALONG THE I80 CORRIDOR WITH
ANOTHER BAND OF CONVECTION JUST NORTH OF THE OHIO RIVER. THIS WILL
COMPLICATE FACTORS OVERNIGHT WITH RESPECT TO THE ONSET OF SHOWERS
AND THE COMBINATION OF UPSTREAM CONVECTION DISRUPTING MOISTURE
TRANSPORT INTO THE REGION AND THE LEAD WAVE TRACKING ALONG OR JUST
SOUTH OF THE NY/PA BORDER. LATEST RAP/RUC AND HRRR SUGGEST THE
THETA-E ADVECTION AND ISENTROPIC LIFT WILL INCREASE TO RESULT IN
LOWERING OF THE CPD/S AND SHOWERS TO DEVELOP WELL AFTER MIDNIGHT.
FOR THIS UPDATE...NO CHANGES TO THE POPS BUT THAT COULD CHANGE
ONCE WE HAVE 00Z RAOBS. MINOR CHANGES TO THE HOURLY FORECASTS AND
SKY COVER.
AS OF 430 PM EDT...A FRONTAL BOUNDARY WAS SITUATED ACROSS THE
GREAT LAKES...WITH THE ASSOCIATED UPPER LEVEL TROUGH DIVING SOUTH
OF CANADA. AT THE SAME TIME...AN MCS WAS MOVING PORTIONS OF OHIO
VALLEY/CENTRAL APPALACHIANS. THIS MCS WILL STAY PLENTY FAR SOUTH
TO AVOID ANY DIRECT IMPACT ON OUR AREA...ALTHOUGH IT MAY ACTUALLY
ROB SOME MOISTURE FROM HEADING INTO THE COLD FRONT.
WE SHOULD STAY DRY FOR MUCH OF THE EVENING WITH INCREASING AMOUNTS
OF MID AND HIGH LEVEL CLOUDINESS. AFTER MIDNIGHT...THERE WILL BE A
CHANCE OF SHOWERS FROM WEST TO EAST. A PERIOD OF SHOWERS IS LIKELY
TOWARDS DAYBREAK...DUE TO INCREASING AMOUNTS OF WARM AIR
ADVECTION/ISENTROPIC LIFT.
MIN TEMPS OVERNIGHT WILL RANGE FROM THE MID 40S TO MID 50S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
THE FIRST WAVE OF SHOWERS ASSOCIATED WITH THE ISENTROPIC LIFT WILL
END BY THE MID MORNING OR SO. AS THE FRONT CONTINUES TO SLIDE
EASTWARD TOWARDS WESTERN NY...ANOTHER BATCH OF SHOWERS WILL OCCUR
FOR THE AFTERNOON INTO THE EVENING HOURS WITH THE SFC FRONTAL
BOUNDARY ITSELF. SKIES SHOULD REMAIN MOSTLY CLOUDY FOR MUCH OF THE
DAY...ALTHOUGH THERE COULD BE A FEW BREAKS IN THE CLOUDS AFTER THE
INITIAL BATCH OF RAIN. WITH THIS SECOND BATCH OF RAIN...THE NAM
SHOWS SMALL AMOUNTS OF SFC BASED INSTABILITY. WE WILL ALLOW FOR
SOME THUNDER...SINCE THERE MAY BE A RUMBLE OR TWO OF THUNDER IN
THESE. WITH THE VERY LOW AMOUNTS OF INSTABILITY...AND POOR LOW/MID
LEVEL LAPSE RATES...THERE ARE NO CONCERNS FOR ANY STRONG STORMS.
MAX TEMPS ON WEDNESDAY WILL BE AROUND THE UPPER 60S TO LOW 70S.
SHOWERS WILL END DURING THE EVENING HOURS ON WEDNESDAY WITH THE
PASSAGE OF THE COLD FRONT. MIN TEMPS WILL RANGE FROM THE UPPER 30S
IN THE DACKS TO THE MID 50S IN THE MID HUDSON VALLEY. TOTAL QPF
LOOKS TO BE AROUND A QUARTER TO THIRD OF AN INCH FOR MOST AREAS.
HIGH TERRAIN AREAS COULD SEE ABOUT A HALF INCH OF RAINFALL...ESP
IN THE SRN DACKS.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR THURSDAY AS THE COLD
FRONT FROM WEDNESDAY STALLS OVER THE MID ATLANTIC STATES. THIS SHOULD
ALLOW FOR DRY CONDITIONS WITH A GOOD DEAL OF SUNSHINE. MAX TEMPS
IN VALLEY AREAS WILL GENERALLY BE IN THE 60S WITH LIGHT SFC WINDS.
A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE STALLED FRONTAL
BOUNDARY OVER THE MID ATLANTIC FOR THURSDAY NIGHT INTO FRIDAY.
THIS STORM WILL MOVE UP THE NORTHEASTERN SEABOARD...BRINGING A
SWATH OF RAIN FOR SOUTHEASTERN PARTS OF THE AREA FOR LATE THURSDAY
NIGHT INTO FRIDAY. IT MAY STAY CLEAR ENOUGH FOR PARTS OF THE
ADIRONDACKS THURSDAY NIGHT FOR SOME FROST FORMATION BEFORE THE
CLOUDS MOVE IN UP THERE FOR FRIDAY. MIN TEMPS THURSDAY NIGHT WILL
RANGE FROM THE MID 30S IN THE CENTRAL DACKS TO NEAR 50 IN THE MID
HUDSON VALLEY. MAX TEMPS ON FRIDAY WILL BE IN THE 60S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A SERIES OF WEAK DISTURBANCES ALONG A QUASI-STATIONARY FRONT ACROSS
PORTIONS OF THE SOUTHERN U.S. WILL PROVIDE PERIODS OF SHOWERS FOR
THE WEEKEND...WITH IMPROVING CONDITIONS BY TUESDAY AS WEAK HIGH
PRESSURE REPLACES THE COLD FRONT SLIDING OFF THE EASTERN SEABOARD.
IN GENERAL...THE BEST CHANCES FOR SIGNIFICANT PRECIPITATION IS
FRIDAY NIGHT WHEN LOW PRESSURE ALONG THE FRONT TRACKS EAST ACROSS
THE MID-ATLANTIC.
TEMPERATURES WILL WARM FROM HIGHS FROM THE MID 50S TO LOWER 60S ON
SATURDAY...TO THE 60S TO AROUND 70 BY TUESDAY. OVERNIGHT LOWS WILL
REMAIN FAIRLY CONSISTENT DURING THE PERIOD...WITH READINGS BOTTOMING
OUT FROM MAINLY THE MID AND UPPER 40S...TO THE LOWER AND MID 50S.
NORMAL HIGHS FOR ALBANY DURING THIS PERIOD ARE IN THE MID AND UPPER
60S...WITH NORMAL LOWS IN THE MID 40S.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
VFR CONDITIONS TO CONTINUE THROUGH THE REST OF THIS EVENING AND
INTO THE EARLY PORTIONS OF THE OVERNIGHT PERIOD...WITH A
DIMINISHING TREND IN BOTH VIS/CIGS AS SHOWER POTENTIAL INCREASES.
A SHORTWAVE TROUGH WILL CONTINUE TO ROTATE CLOSER TO THE REGION
DURING THE OVERNIGHT HOURS ALLOWING INCREASED MOISTURE AND LIFT TO
PROMOTE BROKEN AND EVENTUALLY OVERCAST CEILINGS AFT 06Z AT ALL TAF
SITES. THIS SHORTWAVE TROUGH WILL ACCOMPANY AN INCREASING MOIST ISENTROPIC
LIFT AHEAD OF THE FRONT WILL PROMOTE THE ONSET OF SHOWERS BETWEEN
08Z AND 10Z...AND MVFR CEILINGS AND BORDERLINE MVFR VISIBILITIES
AT ALL TAF SITES. CONFIDENCE IN FOG DEVELOPMENT REMAINS LOW AT THIS TIME
WITH LOW TEMPERATURES ONLY REACHING WET BULB ZERO VALUES AND
GRADIENT WINDS INHIBITING BOUNDARY LAYER DECOUPLING FOR FOG
DEVELOPMENT TO COMMENCE.
SHOWERS ARE EXPECTED TO DECREASE IN COVERAGE DURING THE DAYLIGHT
HOURS ON WEDNESDAY WITH A RENEWED THREAT FOR ADDITIONAL SHOWERS
THROUGH THE DAY. FOR NOW...WE WILL PLACE VCSH AND AWAIT FUTURE
TRENDS AS EXPECTATIONS THAT MVFR THRESHOLDS COULD BE SATISFIED.
WINDS WILL BE LIGHT THROUGH WEDNESDAY OUT OF THE SOUTH-SOUTHWEST
AT 5-12 KTS AS THE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
SYSTEM.
OUTLOOK...
THU-FRI...VFR. CHC MVFR KPOU W/CHC SHWRS ON FRI.
SAT-SUN...MAINLY VFR. CHC -SHRA.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS ARE EXPECTED OVER THE NEXT FEW DAYS. A
FRONTAL BOUNDARY WILL BRING A WETTING RAIN TO THE REGION FOR TONIGHT
INTO TOMORROW. RH VALUES WILL BE NEAR 100 PERCENT TONIGHT. RH VALUES
WILL ONLY DROP TO 60-70 PERCENT TOMORROW...WITH VALUES BACK TO NEAR
100 PERCENT TOMORROW NIGHT. RH VALUES WILL DROP TO NEAR 40 PERCENT
ON THURSDAY AFTERNOON.
SOUTHERLY WINDS OF 5-10 MPH ARE EXPECTED TONIGHT INTO
TOMORROW. WINDS WILL SWITCH TO A NW DIRECTION FOR TOMORROW NIGHT
INTO THURSDAY AT SIMILAR SPEEDS.
&&
.HYDROLOGY...
A FRONTAL BOUNDARY WILL SPREAD SOME RAIN SHOWERS ACROSS THE REGION
FOR TONIGHT INTO TOMORROW...WITH SHOWERS ENDING FROM NORTHWEST TO
SOUTHEAST ON WEDNESDAY EVENING. THERE WILL LIKELY BE TWO MAIN WAVES
OF SHOWERS...WITH ONE PERIOD LATE TONIGHT INTO TOMORROW
MORNING...AND THE NEXT BATCH LATER TOMORROW AFTERNOON INTO TOMORROW
EVENING. BASIN AVERAGE RAINFALL FROM THESE SHOWERS WILL BE AROUND A
THIRD OF AN INCH...ALTHOUGH A FEW SPOTS IN THE HIGHER ELEVATIONS MAY
SEE UP TO A HALF INCH OF RAIN. THIS RAINFALL SHOULD ONLY ALLOW FOR
SMALL RISES ON AREA RIVERS AND STREAMS.
ANOTHER STORM SYSTEM MAY AFFECT SOUTHEASTERN PORTIONS OF THE REGION
FOR THURSDAY NIGHT INTO FRIDAY...WITH UNSETTLED WEATHER POSSIBLY
CONTINUING INTO THE WEEKEND AS WELL. THE MODELS ARE HAVING
DIFFICULTY AGREEING ON EXACTLY HOW MUCH PRECIPITATION OCCURS THROUGH
THIS PERIOD...AS IT WILL DEPEND ON IF THE WEEKEND SYSTEM CUTS OFF
AND LINGERS OVER OUR AREA. ALTHOUGH WIDESPREAD FLOODING ISN/T
EXPECTED AT THIS TIME...WE WILL NEED TO CONTINUE TO MONITOR MODEL
TRENDS OVER THE NEXT FEW DAYS.
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.
&&
.EQUIPMENT...
THE KENX DOPPLER RADAR WILL BE UNDERGOING REPAIRS AS ADDITIONAL
PARTS ARE ON ORDER. THE KENX RADAR WILL CONTINUE TO BE DOWN AND IS
EXPECTED TO BE BACK IN SERVICE BY MID AFTERNOON ON WEDNESDAY
SEPTEMBER 26TH 2012. WE APOLOGIZE FOR ANY INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/BGM
SHORT TERM...FRUGIS
LONG TERM...ELH
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
EQUIPMENT...BGM/BJF
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
340 AM EDT MON SEP 24 2012
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING AN AMPLIFIED UPPER LEVEL
PATTERN OVER THE EASTERN CONUS CONSISTING OF A BROAD LONGWAVE
TROUGH. THIS TROUGH EXTENDS DOWN ALL THE WAY INTO NORTHERN FLORIDA.
HIGH LEVEL SOUTHERN STREAM MOISTURE ROUNDING THE BASE OF THE TROUGH
OVER THE CENTRAL AND SOUTHERN PORTIONS OF THE FLORIDA PENINSULA WILL
CONTINUE AND KEEP THE SUN AT LEAST DIMMED AT TIMES TODAY THROUGH
PERIODS OF HIGH CLOUDS. FURTHER BELOW...DRIER AIR IN THE MID-LEVELS
CONTINUES TO BUILD DOWN OVER THE FLORIDA PENINSULA. THE 00Z KTBW
SOUNDING WAS BEGINNING TO SHOW SIGNS OF THIS DRIER AIRMASS...HOWEVER
JUST A BIT FURTHER NORTH...THE KTLH SOUNDING SHOWED A VERY DRY
AIRMASS HAD ALREADY ARRIVED WITH A PW UNDER 0.8" AND A PRONOUNCED
SUBSIDENCE INVERSION AT 800MB.
AT THE SURFACE...SURFACE COLD FRONT IS MAKING SLOW BUT STEADY
PROGRESS SOUTHWARD ACROSS THE FORECAST AREA EARLY THIS MORNING. AN
ANALYSIS SHOWS THE FRONTAL POSITION IS CURRENTLY ALONG OR A BIT
TO THE SOUTH THE I-4 CORRIDOR. FAIRLY DISTINCT DEWPOINT
GRADIENT ASSOCIATED WITH THIS FRONT. WHEN THE BOUNDARY SLIPPED
THROUGH BROOKSVILLE A FEW HOURS AGO WE SAW THE DEWPOINT DROP FROM 67
TO 59 BETWEEN HOURLY OBSERVATIONS...AND THEN TAMPA INTERNATIONAL
AIRPORT DROPPED FROM 69 TO 60 BETWEEN OBSERVATIONS. THIS MUCH DRIER
SURFACE AIRMASS WILL MAKE FURTHER PROGRESS SOUTHWARD INTO THE
DAYLIGHT HOURS.
&&
.SHORT TERM (TODAY THROUGH WEDNESDAY)...
TODAY...WEAK COLD FRONT WILL CONTINUE TO SETTLE SOUTHWARD ALONG THE
SUNCOAST ZONES THIS MORNING BEFORE STALLING LATER TODAY. NOT
ENTIRELY SURE IF THIS FRONT WILL ACTUALLY PASS SOUTH OF AREAS LIKE
FORT MYERS...HOWEVER IT IS EVIDENT THAT EVEN IF IT DOES...THE DRY
AIR INTRUSION THAT FAR SOUTH WILL BE SIGNIFICANTLY LESS THAN UP
TOWARD TAMPA BAY AND THE NATURE COAST ZONES. THE DRY AIR ABOVE THE
SURFACE WILL MAKE MORE SOUTHWARD PROGRESS...AND THIS SHOULD SET UP A
GENERALLY RAIN FREE DAY FOR ALL ZONES. IN FACT OVER THE
CENTRAL/NORTHERN ZONES THE RH/THETA-E VALUES BETWEEN 850-500MB ARE
IMPRESSIVELY LOW AND REPRESENT QUITE A HOSTILE ENVIRONMENT FOR ANY
CONVECTION. ALONG THE BETTER MOISTURE GRADIENT...A BRIEF SHALLOW-TOP
SHOWER/SPRINKLE UNDERNEATH THIS LAYER IS NOT IMPOSSIBLE DOWN TOWARD
CHARLOTTE/LEE COUNTIES THIS AFTERNOON...BUT CHANCES/COVERAGE SHOULD
BE 10% OR LESS AND WILL LEAVE MENTION OUT OF THE FORECAST.
TONIGHT/TUESDAY...CONTINENTAL HIGH PRESSURE OVER THE EASTERN CONUS
WILL MOVE TO THE MID-ATLANTIC COAST ALLOWING OUR LOW LEVEL WINDS TO
SHIFT AROUND TO A MORE EASTERLY DIRECTION. GUIDANCE IS IN GOOD
AGREEMENT OF A RATHER RAPID RETURN OF LOW LEVEL MOISTURE (BELOW
850MB) OFF THE ATLANTIC. THIS MOISTURE RETURN SHOULD PREVENT LOW
TEMPS FROM REACHING WHAT SOME OF TODAYS AFTERNOON DEWPOINTS MIGHT
SUGGEST. EVEN STILL...WILL EXPECT MANY LOCATION TO REACH THE
MID/UPPER 60S BY SUNRISE TUESDAY MORNING. OVERALL...SHOWER CHANCES
APPEAR LOW ONCE AGAIN FOR THE DAYLIGHT HOURS OF TUESDAY. WILL BRING
SLIGHT CHANCES FOR LOW TOPPED SHOWERS BACK INTO AREAS GENERALLY
SOUTH OF THE I-4 CORRIDOR WHERE THE LAYER HOSTILE TO CONVECTION
ABOVE THE SURFACE WILL BE MORE SHALLOW. FURTHER NORTH WILL KEEP POPS
AT 10% AS IT IS LIKELY ANY SHALLOW SPEED CONVERGENCE SHOWERS
DEVELOPING ALONG THE EAST COAST WILL DISSIPATE BEFORE PENETRATING
INLAND ENOUGH TO REACH OUR ZONES.
WEDNESDAY...FORECAST AREA WILL REMAIN ON THE SOUTH SIDE OF A HIGH
PRESSURE RIDGE CENTERED NEAR THE CAROLINA COAST. EASTERLY LOW LEVEL
FLOW WILL DOMINATE THE PENINSULA UNDERNEATH WEAK UPPER LEVEL
RIDGING. THE COLUMN WILL CONTINUE TO MODIFY/MOISTEN WITH TIME
ALLOWING FOR BETTER CHANCES FOR A FEW AFTERNOON SHOWERS/STORMS...
BUT OVERALL EXPECTING A GENERALLY FAIR AND SEASONABLE DAY FOR THE
MID-POINT OF THE WORK-WEEK.
&&
.LONG TERM (THURSDAY THROUGH SUNDAY)...
THE GFS...ECMWF AND CANADIAN MODELS ARE ALL IN FAIR AGREEMENT
THROUGH FRIDAY. A SURFACE RIDGE OF HIGH PRESSURE NORTH OF THE STATE
KEEPS OUR AREA UNDER EASTERLY FLOW. AFTERNOON SEA BREEZES WILL BE
THE PRIMARY FOCUS FOR DAILY CONVECTION...WITH THE HIGHEST MOISTURE
AND THEREFOR BEST CHANCES FOR RAIN TO THE SOUTH.
BY SATURDAY...IMPORTANT DIFFERENCES POP UP BETWEEN THE MODELS. THE
GFS HAS BEEN CONSISTENTLY SHOWING A RATHER DEEP TROUGH DEVELOPING
OVER THE EASTERN U.S. EXTENDING SOUTHWARD OVER THE NORTHEAST GULF.
THE CANADIAN MODEL HAS THIS FEATURE FARTHER WEST AND IS NOT NEARLY
AS DEEP. THE ECMWF HAS CONSISTENTLY SHOWN FLATTER FLOW OVER THE
REGION WITH NO REAL HINT OF THE SOUTHERN STREAM TROUGH OVER THE GULF
OR NEAR FLORIDA. THE GFS RESPONDS BY SHOWING MORE PRECIPITATION OVER
THE REGION WHICH EXTENDS INTO SATURDAY NIGHT. THE ECMWF IS DRIER
WITH THE SURFACE RIDGE AXIS REMAINING OVER OR JUST NORTH OF NORTHERN
FLORIDA.
ON SUNDAY...THE GFS HAS A COLD FRONT MOVING OFF THE SOUTHEAST U.S.
COAST WHILE THE ECMWF CONTINUES TO HOLD THE ATLANTIC RIDGE OVER THE
REGION. EITHER WAY...EXPECT BEST RAIN CHANCES TO OCCUR DURING THE
AFTERNOON HOURS UNDER A SUMMER-LIKE ATMOSPHERE AS WE FINISH OUT
SEPTEMBER.
&&
.AVIATION...
VFR NEXT 24 HOURS. SEA BREEZES MAY DEVELOP FOR A FEW HOURS THIS
AFTERNOON AT TPA...PIE AND SRQ.
&&
.MARINE...
A WEAK COLD FRONT WILL PUSH SOUTH OF THE REGION TODAY. IN THE WAKE
OF THE FRONT...CONTINENTAL HIGH PRESSURE WILL BUILD TO OUR NORTH
OVER THE EASTERN STATES...AND THEN MOVE TO THE MID-ATLANTIC COAST ON
TUESDAY. NORTHERLY FLOW WILL SHIFT MORE EASTERLY BY MID-WEEK AND
THEN HOLD THROUGH AT LEAST FRIDAY. THE HIGH CENTER TO OUR NORTH AND
NORTHEAST WILL BE FAVORABLE FOR OVERNIGHT AND EARLY MORNING WIND
SURGES THE NEXT SEVERAL NIGHTS WHICH MAY APPROACH CAUTIONARY LEVELS
AT TIMES.
&&
.FIRE WEATHER...
THE FIRST SIGNIFICANT INTRUSION OF SURFACE DRY AIR IS WORKING ITS
WAY SOUTHWARD ACROSS THE AREA IN THE WAKE OF A FRONT. THE DRIEST
CONDITIONS WILL BE FROM TAMPA BAY NORTHWARD WHERE SEVERAL HOURS OF
RELATIVE HUMIDITY AT OR BELOW 35 WILL BE POSSIBLE THIS AFTERNOON.
CURRENTLY DISPERSION ARE EXPECTED TO REMAIN JUST BELOW 75 AND WILL
HOLD OFF ON A RED FLAG WARNING FOR THE NATURE COAST ZONES...HOWEVER
THE SITUATION WILL NEED TO BE MONITORED CLOSELY THROUGH THE DAY.
GUIDANCE IS IN AGREEMENT THAT LOW LEVEL MOISTURE WILL RETURN QUICKLY
TONIGHT AND TUESDAY ENDING THE THREAT FOR CRITICAL FIRE WEATHER
CONDITIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 89 72 90 74 / 0 0 10 10
FMY 91 72 90 73 / 10 10 20 20
GIF 89 69 90 71 / 10 10 20 10
SRQ 87 70 89 72 / 10 0 10 10
BKV 89 64 90 67 / 0 10 10 10
SPG 88 75 89 76 / 0 0 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...JILLSON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1025 PM EDT TUE SEP 25 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 PM EDT TUE SEP 25 2012
AN ACTIVE WEATHER PATTERN WILL KEEP CHANCES FOR SHOWERS AND
THUNDERSTORMS OVER PARTS OF THE AREA THROUGH THE WORK WEEK. HIGH
PRESSURE WILL BUILD IN OVER THE WEEKEND AND DRY THINGS OUT.
TEMPERATURES WILL BEGIN NEAR/JUST ABOVE NORMAL BUT SHOULD DIP TO
NEAR/JUST BELOW NORMAL AS AN UPPER TROUGH SETTLES IN FROM CANADA.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1004 PM EDT TUE SEP 25 2012
MAIN BAND OF THUNDERSTORMS HAS FINALLY ENTERED THE EXTREME SOUTHWEST
PORTION OF THE FORECAST AREA WITHIN THE LAST HOUR. STORMS HAVE BEEN
SLOWLY DIMINISHING IN INTENSITY AS THEY MADE THEIR WAY ACROSS
ILLINOIS SO DO NOT EXPECT MUCH IN THE WAY OF SEVERE. HOWEVER...SOME
SMALL HAIL AND WIND GUSTS UP TO 40 MPH ARE NOT OUT OF THE QUESTION
FOR THE NEXT HOUR OR TWO.
IN REGARDS TO THE FORECAST...MAIN CHANGE WAS TO ADJUST POPS FOR
CURRENT CONDITIONS. CONDITIONS HAVE BEEN DRY THIS EVENING ACROSS THE
NORTHERN TWO THIRDS OF THE AREA EXCEPT FOR A FEW SCATTERED LIGHT
SHOWERS. THEREFORE...CUT POPS WAY BACK ACROSS THIS AREA FOR THE
REMAINDER OF THE EVENING WITH JUST SOME SHOWER MENTION. THE RAP HAS
HAD A PRETTY DECENT HANDLE ON THE CONVECTION TONIGHT SO WILL FOLLOW
ITS PROJECTION OF INCREASING SHOWERS...AND PROBABLY SOME
THUNDER...IN THE 06-09Z TIME FRAME. THE BEST FORCING AND ASSOCIATED
VORTICITY MAX LOOK TO PASS THROUGH DURING THIS TIME FRAME...FOCUSING
MAINLY ON THE SOUTHERN TWO THIRDS OF THE AREA WHERE I KEPT THE
HIGHEST POPS. ADDITIONALLY...THE LOW LEVEL JET REALLY BEGINS TO RAMP
UP AFTER 06Z AND PRECIPITABLE WATER VALUES INCREASE TO NEAR 1.75
INCHES.
TEMPERATURES LOOK TO MAINLY BE ON TRACK...JUST BUMPED UP LOWS A
DEGREE OR TWO IN THE EXTREME SOUTH WITH TEMPERATURES STILL IN THE
UPPER 60S IN PLACES WHERE STORMS ALREADY MOVED THROUGH.
UPDATED GRIDS AND ZONES ALREADY SENT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 337 PM EDT TUE SEP 25 2012
FORECAST FOCUS IS ON POPS. RELATIVELY ZONAL FLOW WILL ALLOW
SHORTWAVES TO RAPIDLY MOVE THROUGH THE FLOW AND PROVIDE
PRECIPITATION TO THE AREA DURING THE SHORT TERM. WITH A FRONT
SAGGING SOUTH THROUGH THE AREA AND A SHORT WAVE MOVING THROUGH THE
FLOW WILL KEEP SOME CATEGORICAL POPS GOING ON WEDNESDAY WITH
LIKELIES ACROSS ALL BUT THE NORTHWEST AS BEST FORCING AGAIN WILL BE
FOCUSED ALONG AND SOUTH OF THE FRONTAL BOUNDARY. AS THE FRONT SINKS
SOUTH POPS DECREASE IN TIME FROM NORTH TO SOUTH WITH SURFACE HIGH
PRESSURE BUILDING IN FROM THE NORTH. WHILE ENOUGH FORCING AND
INSTABILITY WILL BE AROUND WEDNESDAY AND WEDNESDAY NIGHT TO WARRANT
CHANCES FOR THUNDERSTORMS...BY THURSDAY THERE IS LITTLE LEFT AND
WILL JUST KEEP A SLIGHT CHANCE IN THE FAR SOUTH WHERE A BIT OF
ELEVATED INSTABILITY MAY STILL RESIDE.
WITH THE FRONT SERVING AS A FOCUSING MECHANISM FOR PRECIPITATION
THE NEXT COUPLE OF DAYS AND GOOD FLOW OFF THE GULF COULD SEE SOME
POTENTIAL FOR LOCALIZED NUISANCE FLOODING. AT THIS POINT DOESN/T
LOOK WIDESPREAD ENOUGH TO NECESSITATE A HEADLINE BUT WILL NEED TO
WATCH.
FOR TEMPERATURES GENERALLY THOUGHT A CONSENSUS WORKED WELL AS MUCH
IS CONTINGENT UPON EXACT FRONTAL POSITION AND ATTENDANT CLOUD COVER.
HIGHS IN THE 70S ON WEDNESDAY WITH 60S WORKING THEIR WAY INTO THE
NORTH ON THURSDAY AND FRIDAY WITH A BIT OF COLD ADVECTION UP THERE.
LOWS MAINLY IN THE 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 141 PM EDT TUE SEP 25 2012
THE MAIN FOCUS TO THE EXTENDED WILL BE WHETHER OR NOT TO KEEP LOW
POPS ACROSS THE SOUTH FRIDAY NIGHT AND SATURDAY PER THE CENTRAL
REGION INITIALIZATION. LONG RANGE MODELS ARE IN GOOD AGREEMENT ON A
DRY FORECAST FOR THE REMAINDER OF THE EXTENDED AS A BROAD AREA OF
SURFACE HIGH PRESSURE SETS UP ACROSS THE OHIO VALLEY WITH A LOW
PRESSURE SYSTEM WELL TO THE SOUTH ACROSS THE SOUTHERN STATES AND AN
UPPER LOW NEAR THE SAINT LAWRENCE VALLEY.
WITH THE LONG RANGE MODELS STILL SHOWING A GOOD DEGREE OF MODEL TO
MODEL AND MODEL VERSUS MODEL UNCERTAINTY...WILL ACCEPT THE SMALL
POPS FROM CR INIT FRIDAY NIGHT ACROSS THE WHOLE FORECAST AREA AND
SATURDAY ACROSS JUST OUR FAR SOUTH. WILL ALSO ACCEPT THE SLIGHTLY
BELOW NORMAL TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR 260300Z KIND TAF UPDATE/...
ISSUED AT 1025 PM EDT TUE SEP 25 2012
MINOR TWEAKS MADE TO KIND TAF PER OBSERVATIONS. NO OTHER CHANGES
NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION FOLLOWS...
NUMEROUS SHOWERS AND THUNDERSTORMS OVER MISSOURI...SOUTHERN ILLINOIS
WILL CONTINUE TO SPREAD EAST ACROSS SOUTHERN INDIANA OVERNIGHT AS
850 MB INFLOW JET INCREASES. AS A RESULT WILL CONTINUE MENTION OF
VCTS FROM KHUF AND SOUTHWARD AND PERIODS OF THUNDERSTORMS WILL
LIKELY MOVE ACROSS KBMG TAF SITE LATER TONIGHT. THE COMBINATION OF
WIDESPREAD PRECIPITATION AND SLIGHT COOLING OVERNIGHT WILL CAUSE
AREAS STRATUS TO INCREASE LATER TONIGHT. MODEL GUIDANCE INDICATE
CEILINGS MAY BE MOSTLY IN THE 1 TO 2 THOUSAND FEET RANGE LATE
TONIGHT AND WEDNESDAY MORNING. LITTLE LESS CERTAIN AT KBMG AS WARM
FRONT MAY BE FAR ENOUGH NORTH TO LESSEN RISK OF LOWER CEILINGS
THERE.
OTHERWISE...TIME HEIGHT CROSS SECTIONS INDICATE MOSTLY MVFR CEILINGS
TO ABOUT MIDDAY WEDNESDAY AND MOSTLY VFR WITH CEILINGS SLIGHTLY
ABOVE 3 THOUSAND WEDNESDAY AFTERNOON. WILL MENTION VCTS ALL TAF
SITES WEDNESDAY AFTERNOON AS A COLD FRONT MOVES SLOWLY SOUTH INTO
OUR AREA.
WINDS WILL BE 8 KNOTS OR LESS OVERNIGHT AND WEDNESDAY MORNING AND
SOUTHWEST TO WEST 10 TO 12 KNOTS WEDNESDAY AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...HOMANN
SHORT TERM...CP
LONG TERM....MK
AVIATION...JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1007 PM EDT TUE SEP 25 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 PM EDT TUE SEP 25 2012
AN ACTIVE WEATHER PATTERN WILL KEEP CHANCES FOR SHOWERS AND
THUNDERSTORMS OVER PARTS OF THE AREA THROUGH THE WORK WEEK. HIGH
PRESSURE WILL BUILD IN OVER THE WEEKEND AND DRY THINGS OUT.
TEMPERATURES WILL BEGIN NEAR/JUST ABOVE NORMAL BUT SHOULD DIP TO
NEAR/JUST BELOW NORMAL AS AN UPPER TROUGH SETTLES IN FROM CANADA.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1004 PM EDT TUE SEP 25 2012
MAIN BAND OF THUNDERSTORMS HAS FINALLY ENTERED THE EXTREME SOUTHWEST
PORTION OF THE FORECAST AREA WITHIN THE LAST HOUR. STORMS HAVE BEEN
SLOWLY DIMINISHING IN INTENSITY AS THEY MADE THEIR WAY ACROSS
ILLINOIS SO DO NOT EXPECT MUCH IN THE WAY OF SEVERE. HOWEVER...SOME
SMALL HAIL AND WIND GUSTS UP TO 40 MPH ARE NOT OUT OF THE QUESTION
FOR THE NEXT HOUR OR TWO.
IN REGARDS TO THE FORECAST...MAIN CHANGE WAS TO ADJUST POPS FOR
CURRENT CONDITIONS. CONDITIONS HAVE BEEN DRY THIS EVENING ACROSS THE
NORTHERN TWO THIRDS OF THE AREA EXCEPT FOR A FEW SCATTERED LIGHT
SHOWERS. THEREFORE...CUT POPS WAY BACK ACROSS THIS AREA FOR THE
REMAINDER OF THE EVENING WITH JUST SOME SHOWER MENTION. THE RAP HAS
HAD A PRETTY DECENT HANDLE ON THE CONVECTION TONIGHT SO WILL FOLLOW
ITS PROJECTION OF INCREASING SHOWERS...AND PROBABLY SOME
THUNDER...IN THE 06-09Z TIME FRAME. THE BEST FORCING AND ASSOCIATED
VORTICITY MAX LOOK TO PASS THROUGH DURING THIS TIME FRAME...FOCUSING
MAINLY ON THE SOUTHERN TWO THIRDS OF THE AREA WHERE I KEPT THE
HIGHEST POPS. ADDITIONALLY...THE LOW LEVEL JET REALLY BEGINS TO RAMP
UP AFTER 06Z AND PRECIPITABLE WATER VALUES INCREASE TO NEAR 1.75
INCHES.
TEMPERATURES LOOK TO MAINLY BE ON TRACK...JUST BUMPED UP LOWS A
DEGREE OR TWO IN THE EXTREME SOUTH WITH TEMPERATURES STILL IN THE
UPPER 60S IN PLACES WHERE STORMS ALREADY MOVED THROUGH.
UPDATED GRIDS AND ZONES ALREADY SENT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 337 PM EDT TUE SEP 25 2012
FORECAST FOCUS IS ON POPS. RELATIVELY ZONAL FLOW WILL ALLOW
SHORTWAVES TO RAPIDLY MOVE THROUGH THE FLOW AND PROVIDE
PRECIPITATION TO THE AREA DURING THE SHORT TERM. WITH A FRONT
SAGGING SOUTH THROUGH THE AREA AND A SHORT WAVE MOVING THROUGH THE
FLOW WILL KEEP SOME CATEGORICAL POPS GOING ON WEDNESDAY WITH
LIKELIES ACROSS ALL BUT THE NORTHWEST AS BEST FORCING AGAIN WILL BE
FOCUSED ALONG AND SOUTH OF THE FRONTAL BOUNDARY. AS THE FRONT SINKS
SOUTH POPS DECREASE IN TIME FROM NORTH TO SOUTH WITH SURFACE HIGH
PRESSURE BUILDING IN FROM THE NORTH. WHILE ENOUGH FORCING AND
INSTABILITY WILL BE AROUND WEDNESDAY AND WEDNESDAY NIGHT TO WARRANT
CHANCES FOR THUNDERSTORMS...BY THURSDAY THERE IS LITTLE LEFT AND
WILL JUST KEEP A SLIGHT CHANCE IN THE FAR SOUTH WHERE A BIT OF
ELEVATED INSTABILITY MAY STILL RESIDE.
WITH THE FRONT SERVING AS A FOCUSING MECHANISM FOR PRECIPITATION
THE NEXT COUPLE OF DAYS AND GOOD FLOW OFF THE GULF COULD SEE SOME
POTENTIAL FOR LOCALIZED NUISANCE FLOODING. AT THIS POINT DOESN/T
LOOK WIDESPREAD ENOUGH TO NECESSITATE A HEADLINE BUT WILL NEED TO
WATCH.
FOR TEMPERATURES GENERALLY THOUGHT A CONSENSUS WORKED WELL AS MUCH
IS CONTINGENT UPON EXACT FRONTAL POSITION AND ATTENDANT CLOUD COVER.
HIGHS IN THE 70S ON WEDNESDAY WITH 60S WORKING THEIR WAY INTO THE
NORTH ON THURSDAY AND FRIDAY WITH A BIT OF COLD ADVECTION UP THERE.
LOWS MAINLY IN THE 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 141 PM EDT TUE SEP 25 2012
THE MAIN FOCUS TO THE EXTENDED WILL BE WHETHER OR NOT TO KEEP LOW
POPS ACROSS THE SOUTH FRIDAY NIGHT AND SATURDAY PER THE CENTRAL
REGION INITIALIZATION. LONG RANGE MODELS ARE IN GOOD AGREEMENT ON A
DRY FORECAST FOR THE REMAINDER OF THE EXTENDED AS A BROAD AREA OF
SURFACE HIGH PRESSURE SETS UP ACROSS THE OHIO VALLEY WITH A LOW
PRESSURE SYSTEM WELL TO THE SOUTH ACROSS THE SOUTHERN STATES AND AN
UPPER LOW NEAR THE SAINT LAWRENCE VALLEY.
WITH THE LONG RANGE MODELS STILL SHOWING A GOOD DEGREE OF MODEL TO
MODEL AND MODEL VERSUS MODEL UNCERTAINTY...WILL ACCEPT THE SMALL
POPS FROM CR INIT FRIDAY NIGHT ACROSS THE WHOLE FORECAST AREA AND
SATURDAY ACROSS JUST OUR FAR SOUTH. WILL ALSO ACCEPT THE SLIGHTLY
BELOW NORMAL TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR 260000Z TAF ISSUANCE/...
ISSUED AT 650 PM EDT TUE SEP 25 2012
NUMEROUS SHOWERS AND THUNDERSTORMS OVER MISSOURI...SOUTHERN ILLINOIS
WILL CONTINUE TO SPREAD EAST ACROSS SOUTHERN INDIANA OVERNIGHT AS
850 MB INFLOW JET INCREASES. AS A RESULT WILL CONTINUE MENTION OF
VCTS FROM KHUF AND SOUTHWARD AND PERIODS OF THUNDERSTORMS WILL
LIKELY MOVE ACROSS KBMG TAF SITE LATER TONIGHT. THE COMBINATION OF
WIDESPREAD PRECIPITATION AND SLIGHT COOLING OVERNIGHT WILL CAUSE
AREAS STRATUS TO INCREASE LATER TONIGHT. MODEL GUIDANCE INDICATE
CEILINGS MAY BE MOSTLY IN THE 1 TO 2 THOUSAND FEET RANGE LATE
TONIGHT AND WEDNESDAY MORNING. LITTLE LESS CERTAIN AT KBMG AS WARM
FRONT MAY BE FAR ENOUGH NORTH TO LESSEN RISK OF LOWER CEILINGS
THERE.
OTHERWISE...TIME HEIGHT CROSS SECTIONS INDICATE MOSTLY MVFR CEILINGS
TO ABOUT MIDDAY WEDNESDAY AND MOSTLY VFR WITH CEILINGS SLIGHTLY
ABOVE 3 THOUSAND WEDNESDAY AFTERNOON. WILL MENTION VCTS ALL TAF
SITES WEDNESDAY AFTERNOON AS A COLD FRONT MOVES SLOWLY SOUTH INTO
OUR AREA.
WINDS WILL BE 8 KNOTS OR LESS OVERNIGHT AND WEDNESDAY MORNING AND
SOUTHWEST TO WEST 10 TO 12 KNOTS WEDNESDAY AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...HOMANN
SHORT TERM...CP
LONG TERM....MK
AVIATION...JH
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
745 PM EDT TUE SEP 25 2012
...AVIATION...
CONCERNS FOR FOG/STRATUS GROWING OVERNIGHT. WEAK COLD FRONT
APPROACHING FROM NORTHWEST ALLOWING DEW POINTS TO POOL NEAR 60 THIS
EVENING. WEAKENING WINDS THIS EVENING ALONG WITH PARTIAL CLEARING
APPEARS TO BE SETTING THE STAGE FOR STRATUS AND/OR FOG DEVELOPMENT
OVERNIGHT. SEVERAL HIGH RESOLUTION MODELS INCLUDING HRRR AND RAP
SHOWING THIS ACROSS MUCH OF THE AREA INCLUDING TAF SITES. THE
QUESTION AS USUAL IS WHETHER STRATUS OR DENSE FOG WILL DEVELOP. FOR
NOW WITH THIS TAF PACKAGE LEANED TOWARD STRATUS WITH A LACK OF RAIN
TODAY AT TAF SITES. HOWEVER...AS MENTIONED...POOLING DEW POINTS MAY
BE ENOUGH TO OFFSET THIS GIVEN RECENT RAINFALL. DID BRING KSBN VIS
DOWN TO 2SM FOR NOW. FURTHER ADJUSTMENTS LIKELY THROUGH THE EVENING
AND OVERNIGHT. WEAK FRONT PUSHES THROUGH WEDNESDAY WITH CONDITIONS
BECOMING VFR DURING THE DAY.
&&
.UPDATE...
GOING GRIDS WILL BE NEED SOME WORK WITH OBVIOUS DISCREPENCIES
BETWEEN SKY COVER AND TAFS. FAVOR INCREASING STRATUS THROUGH THE
NIGHT CENTRAL AND NORTH WITH MOISTURE POOLING HELPING SOME FOG TO
DEVELOP GIVEN WEAK WIND FIELDS. HRRR REALLY PICKING UP ON THIS AS IT
DID SEVERAL NIGHTS AGO. EXPECTING THE STRATUS DEVELOPMENT TO HELP
KEEP VIS IN THE 2SM TO 4SM RANGE GIVEN LACK OF RAIN TODAY. HOWEVER
THIS IS DEPENDENT ON DEPTH AND AMOUNT OF STRATUS DEVELOPMENT.
EXCEPTION TO THIS IS IN THE SOUTH WHERE IT DID RAIN TODAY BUT CLOUDS
EXPECTED CONTINUE THIS EVENING WITH LITTLE CLEARING WHICH SHOULD
HELP OFFSET ANY FOG DEVELOPMENT.
&&
.SHORT TERM.../TONIGHT THROUGH WEDNESDAY NIGHT/
MCV CURRENTLY MOVING ACROSS FAR SOUTHERN COUNTIES WILL QUICKLY EXIT
BY 21Z. SUBSIDENCE IN ITS WAKE WILL LIKELY HELP SET THE STAGE FOR
DIMINISHING CHANCES OF ADDITIONAL PRECIP INTO TONIGHT. PRE 1ST
PERIOD MENTION OF INCREASED POPS TO COVER DEPARTURE OF THIS
FEATURE. VIS SAT/SFC OBS INDICATE NOSE OF INCREASING THETA E
EDGING INTO E ILLINOIS WITH A BATCH OF LOW CLOUDS ASSOCIATED WITH
IT. WILL CONTINUE TO MONITOR THIS FEATURE FOR ANY SHOWER
DEVELOPMENT BUT SUSPECT NOTHING WILL COME OF IT WITH MAIN FORCING
SOUTH. COLD FRONT TO THE NORTH HAS SLOWED AS EXPECTED WITH MODELS
STILL DROPPING IT SOUTH INTO NORTHERN AREAS LATER TONIGHT. BY THE
TIME IT ARRIVES...LITTLE IMPACT IN TERMS OF POPS IS EXPECTED...BUT
ASSOCIATED MSTR WITH IT COULD AID IN STRATUS/FOG POTENTIAL. HAVE
STAYED CONSERVATIVE AND WENT WITH CLEARING TREND NORTH AND HANG
ONTO CLOUDS SOUTH. GIVEN TRENDS...JUST CAN`T SEE HOLDING ONTO
LIKELY POPS IN FAR SOUTH AND AFTER COORDINATION HAVE LOWERED TO
HIGH END CHC. ALSO TAPERED POPS QUICKLY TO THE NORTH.
ON WEDS...COLD FRONT WILL DROP INTO THE AREA. POTENTIAL FOR LATE
MORNING INTO AFTERNOON CONVECTION ON THE FRONT REMAINS AS ENERGY
MOVES ALONG THE FRONT. HOWEVER...EFFECTIVE LL MSTR COULD BE GUTTED
ALREADY FROM OVERNIGHT CONVECTION TO THE SOUTH ALLOWING FOR AT MOST
SCT SHOWERS SE. ONLY MINOR CHANGES TO GRIDS WITH TEMPS STILL VERY
SEASONABLE AROUND 70. FRONT WILL BE WELL SOUTH OF THE AREA BY WEDS
NGT WITH CLEAR SKIES AND SEASONABLE LOWS.
&&
.LONG TERM...
PERIOD WILL BE DOMINATED BY SPRAWLING HIGH PRESSURE ACROSS THE
REGION. AS HUDSON BAY UPPER LOW DEPARTS ANOTHER WAVE WILL TAKE ITS
PLACE WITH SOUTHERN EXTENSION SWEEPING ACROSS THE GREAT LAKES.
FEATURE WILL BE MSTR STARVED WITH ONLY REAL EFFECT BEING A
CONTINUATION OF NEAR NORMAL TEMPERATURES AND NO APPRECIABLE PRECIP
CHANCES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...T/FISHER
AVIATION...LASHLEY
AREA FORECAST DISCUSSION
NWS TOPEKA KS
726 PM CDT TUE SEP 25 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT TERM - THROUGH WEDNESDAY...
SURFACE ANALYSIS AT 18Z INDICATED THAT A RATHER WELL DEFINED SURFACE
LOW OVER FAR SOUTH CENTRAL KANSAS AND NORTH CENTRAL OKLAHOMA...NEAR
THE BORDER OF THE TWO STATES. A SURFACE BOUNDARY...WHICH IS A
REMNANT OF THE BOUNDARY WHICH CAUSED OVERNIGHT SHOWERS IN EASTERN
KANSAS AND WESTERN MISSOURI...IS CURRENTLY LOCATED GENERALLY ACROSS
SOUTHEASTERN KANSAS AND MORE SPECIFICALLY ALONG A LINE ROUGHLY FROM
GARNETT KS TO WELLINGTON KS. THIS BOUNDARY WILL LIKELY BE THE FOCUS
FOR SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON INTO THIS
EVENING. CURRENT SURFACE WINDS NORTH AND WEST OF THE BOUNDARY ARE
OUT OF THE E-NE...WHILE WINDS TO THE SOUTH AND EAST OF THE BOUNDARY
ARE MORE FROM THE SW. THESE PARALLEL AND OPPOSING WINDS ARE NOT
CREATING ENOUGH CONVERGENCE AT THE MOMENT TO GET LOW LEVEL UPWARD
MOTION. HOWEVER AS THE LOW SLIDES EASTWARD SURFACE WINDS MAY BACK A
LITTLE IN RESPONSE TO THE LOWS MOVEMENT. MODEL FORECAST SOUNDINGS
FOR SOUTHEAST KANSAS INDICATE THAT A STOUT LOW/MID LEVEL WARM NOSE
WILL REMAIN ESTABLISHED THROUGH ABOUT 22Z. AT THAT TIME CONVECTION
MAY OCCUR ALONG AND NEAR THAT BOUNDARY. FURTHER ENHANCING CONVECTION
POTENTIAL IS DECENT 850 MB CONVERGENCE AS SW 850 MB WINDS AT 20 TO
30 KTS NOSE INTO SLIGHTLY SLOWER 850 MB WINDS ACROSS EAST CENTRAL
KANSAS. MID/UPPER SUPPORT FOR ASCENT SHOULD COME LATER ON TONIGHT AS
A QUICKLY MOVING SHORTWAVE TROUGH CRUISES THROUGH THE AREA. THE
COMBINATION OF THE AFOREMENTIONED FACTORS SHOULD LEAD TO SCATTERED
CONVECTION ACROSS PARTS OF EAST CENTRAL AND SOUTHEAST KANSAS. AS
SURFACE WINDS BECOME MORE BACKED THE BOUNDARY MAY ALSO SHIFT
NORTHWARD...CAUSING AREAS ALONG AND SOUTH OF THE KANSAS TURNPIKE TO
HAVE A CHANCE FOR SOME SHOWERS AND THUNDERSTORMS. RAP MESOANALYSIS
AT 18Z SHOWS THAT AROUND 2500 J/KG OF MLCAPE EXISTS ALONG AND SOUTH
OF THAT BOUNDARY INDICATING THAT ANY UPDRAFT THAT IS ABLE TO GET
GOING WILL HAVE QUITE A BIT OF INSTABILITY TO WORK WITH. UPDRAFTS
WILL ALSO HAVE AROUND 20 KTS OF DEEP SHEAR TO WORK WITH...SO SOME
UPDRAFT PERSISTENCE WILL BE POSSIBLE. THE STRONGER CONVECTIVE CELLS
WILL HAVE THE CAPABILITY TO POTENTIALLY PRODUCE SOME LARGE
HAIL...PERHAPS UP TO QUARTER SIZED. CLOUD BASES MAY BE IN THE 5 KFT
TO 6 KFT RANGE WITH GOOD LOW LEVEL LAPSE RATES AND DRY AIR BELOW THE
CLOUD LAYER...SO STRONG GUSTY WINDS WILL ALSO BE POSSIBLE WITH THE
STRONGEST UPDRAFTS. ALTHOUGH A FEW STORMS ARE EXPECTED TO BE STRONG
THIS AFTERNOON WIDESPREAD SEVERE WEATHER IS NOT EXPECTED...WITH THE
MAIN THREAT AREA EXPECTED TO BE ALONG AND SOUTH OF THE KANSAS
TURNPIKE.
WITH THE BOUNDARY REMAINING NEAR THE FORECAST AREA THROUGH THE NIGHT
PERIODS OF MODERATE TO HEAVY RAIN WILL BE POSSIBLE ACROSS AREAS OF
EAST CENTRAL AND SOUTHEASTERN KANSAS. A FEW SHOWERS WILL ALSO BE
POSSIBLE ON WEDNESDAY AS A CONTINUATION OF TUESDAY NIGHTS SHOWERS
AND THUNDERSTORMS. EXPECT THERE TO BE A RATHER TIGHT GRADIENT
BETWEEN THE HIGHER END POPS SOUTH OF INTERSTATE 70 AND AREAS TO THE
NORTH NEAR THE KS/NE BORDER...WITH THE HIGHEST POPS REMAINING IN
EAST CENTRAL AND SOUTHEAST KANSAS.
JL
MID TERM - WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...
THE UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH THIS PERIOD AS
THE STATIONARY FRONTAL BOUNDARY IS FORECAST TO REMAIN IN THE
AREA...ALTHOUGH PRECIP CHANCES WILL VARY A BIT BASED ON TIMING OF
MID LEVEL SHORT WAVE TROUGHS AND MINOR NORTH TO SOUTH FLUCTUATIONS
IN THE LOCATION OF THE FRONT. THE EXACT TIMING OF THE WEAK TROUGHS
AND ASSOCIATED ENHANCEMENTS IN PRECIPITATION COVERAGE REMAINS
RATHER DIFFICULT TO PIN POINT AT THIS TIME...BUT IT CURRENTLY
LOOKS LIKE WEDNESDAY EVENING AND THURSDAY NIGHT-FRIDAY MORNING
WILL HAVE THE BEST CHANCES FOR MORE WIDESPREAD PRECIP ACROSS THE
AREA. EVEN THEN...THE RAIN CHANCES WILL INCREASE FROM NORTH TO
SOUTH ACROSS THE AREA AS THERE IS MORE CONFIDENCE IN THE FRONT
SETTING UP SOUTH OF THE AREA THAN IN A NORTHWARD SHIFT. THE SHORT
WAVE SCHEDULED FOR THURSDAY NIGHT INTO FRIDAY MORNING SHOULD BE
STRONG ENOUGH TO PUSH THE FRONT FARTHER TO THE SOUTH AND BRING IN
DRIER AIR FROM THE NORTH. THIS SHOULD EFFECTIVELY CUT OFF THE
PRECIP CHANCES FROM NORTH TO SOUTH LATE FRIDAY INTO FRIDAY NIGHT.
THE POTENTIAL FOR ISOLATED STRONG STORMS AND ISOLATED HEAVY
RAINFALL AMOUNTS WILL CONTINUE THROUGH THE MAJORITY OF THIS
PERIOD. SEVERE POTENTIAL WILL DECREASE WITH TIME AS INSTABILITY
GRADUALLY WANES WITH WEAKER LAPSE RATES ALOFT. HOWEVER...DEEP
LAYER SHEAR WILL INCREASE A BIT WITH SOME LOCAL MAXIMA IN
INSTABILITY WHICH MAY PRESENT SOME LOCALIZED STRONG TO SEVERE
STORM POTENTIAL. THE HEAVY RAIN POTENTIAL IS A RESULT OF PWAT
VALUES INCREASING TO 1.5 INCHES OR HIGHER...CLIMATOLOGICALLY
HIGH... THE PRESENCE OF WIDESPREAD WEAK TO MODERATE INSTABILITY...
AND STORM MOTIONS THAT MAY OCCASIONALLY SUPPORT TRAINING ALONG OR
NEAR THE FRONTAL BOUNDARY. EVEN WITH HEAVY RAIN POTENTIAL...
FLOODING POTENTIAL APPEARS QUITE LOW GIVEN THE SOIL CONDITIONS...
STREAM BASE FLOW LEVELS...AND AVAILABLE WATER STORAGE IN AREA
LAKES AND PONDS.
HIGHS IN THE 70S ARE EXPECTED ONCE AGAIN THURSDAY AND FRIDAY WITH
AMPLE CLOUD COVER IN PLACE. THE CLOUDS WILL ALSO LIMIT THE DIURNAL
TEMPERATURE SWING SO LOWS SHOULD ONLY DROP INTO THE MIDDLE 50S TO
LOWER 60S.
BARJENBRUCH
LONG TERM - SATURDAY THROUGH TUESDAY...
A RATHER DEEP UPPER TROUGH SETTLES SOUTH INTO THE OHIO VALLEY ON
SATURDAY WITH NORTHERLY FLOW ALOFT AND DRY HIGH PRESSURE AT THE
SURFACE. WHILE THE LONG TERM MODEL GUIDANCE DIFFERS SOMEWHAT IN
OVERALL FLOW SOLUTIONS...THE EXPECTED RESULT IS THE SAME AND A
PERIOD OF DRY STABLE CONDITIONS IS EXPECTED FROM SATURDAY THROUGH
THE END OF THE FORECAST PERIOD ON TUESDAY. THERE ARE SOME
INDICATIONS OF A RATHER PERSISTENT BAND OF FRONTOGENESIS AND
ISENTROPIC ASCENT IN CENTRAL TO WESTERN KANSAS ON THE WESTERN
FLANK OF THE SURFACE HIGH BY LATE IN THE WEEKEND...BUT THIS LOOKS
LIKE A SET UP FOR SPRINKLES AT BEST AND HAVE NOT BROUGHT PRECIP
CHANCES INTO THE FORECAST AT THIS TIME. EXPECT TEMPERATURES
TOPPING OUT IN THE 70S WITH LOWS AROUND 50 ESSENTIALLY EVERY DAY
DURING THIS PERIOD OWING TO NEARLY NEUTRAL TEMPERATURE ADVECTION.
THE OCCASIONAL PRESENCE OF CLOUDS VERSUS CLEAR AND CALM CONDITIONS
OVERNIGHT COULD IMPACT LOWS...BUT THERE IS NO CLEAR SIGNAL AT THIS
TIME POINTING TO ANY NIGHTS BEING PARTICULARLY CLEAR AND COLD.
BARJENBRUCH
&&
.AVIATION...
THE LOW LEVEL FLOW INCREASING NORTH OF THE STALLED FRONT TO THE
SOUTH...EXPECT SCATTERED THUNDERSTORMS TO SLOWLY DEVELOP
NORTHWARD TOWARDS THE I 70 CORRIDOR THROUGH 04Z...THEN SHIFT
EASTWARD OUT OF THE AREA BY 10Z. WITH THE NORTHWARD EXTENT OF THE
CONVECTION STILL IN QUESTION WILL ONLY CARRY VCTS FOR NOW IN THE
TAFS. CONFIDENCE IN CONVECTION OCCURRING 12Z-23Z/26 REMAINS TOO
LOW TO INCLUDE IN THE TAFS AT THIS TIME WITH THE BOUNDARY
REMAINING FURTHER SOUTH. LIGHT AND VARIABLE WINDS TONIGHT WILL
BECOME EASTERLY AFT 10Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
937 PM EDT TUE SEP 25 2012
.Forecast Update...
Updated at 935 PM EDT Tue Sep 25 2012
The line of convection looks to be weakening somewhat this evening
as the gust front pulls out ahead of the convection, though strong
storms are still expected to affect the area tonight. So far we have
had no reports of strong winds or hail from the storms over southern
Indiana. Storm coverage will continue to increase over southern
Indiana over the next few hours, with the activity slowly sinking
south overnight. Have increased pops over the northernmost tier of
counties in southern Indiana to account for the storms heading into
the region. Grids were also brought into line with the latest
observations.
&&
.Short Term (This afternoon through Wednesday Night)...
Issued at 331 PM EDT Tue Sep 25 2012
Morning convective complex continues to head eastward through the
coal fields of eastern Kentucky this afternoon. Satellite and
surface observations reveal clearing skies to the west of our area.
Areas west of I-65 have already cleared out and temperatures are on
the way up. Further east, mid-high level cloud debris remain, but
some clearing is expected to occur by late afternoon and early
evening in those areas. Dry conditions are expected for the
remainder of the afternoon as the atmosphere recovers from this
morning`s storminess. Temperatures will increase this afternoon as
the sun comes back out, but we will not have much time to work with
to get readings all that high. Still think that we`ll see maximum
temperature readings in the mid-upper 70s in the far west with upper
60s-lower 70s in the central and mid-upper 60s in the east.
Later this afternoon and evening, the deterministic NCEP models all
agree on redeveloping convection along a frontal boundary draped to
our north/northwest. While the atmosphere over south-central
Indiana and much of north-central Kentucky has been convectively
overturned, the atmosphere across western/southwestern Kentucky has
largely been undisturbed. High resolution model runs from the
LMK-WRF, SPC WRF, the RAP, and the HRRR all show increasing
instability across southern IL, eastern MO, and western Kentucky
this afternoon. Model proximity soundings generally show an
elevated mixed layer atop a fairly moist near-surface layer. Wind
fields are sheared in both speed and direction and strong lapse
rates aloft should promote vigorous convective development along
and ahead of this front. Severe convection is likely to our west
this evening and tonight, but is highly questionable across the LMK
forecast area due to this morning`s convection.
Current thinking is that we`ll see a line of convection develop to
our northwest this evening and then slide toward the Ohio River
later tonight. As this line encounters our worked over airmass,
we`ll likely see the convection continue, since the wind shear is
fairly decent and we`ll have instability aloft. The near surface
environment looks to remain largely stable, so any storms that we
see would likely result in torrential rains, some hail and quite a
bit of cloud to ground lightning. The remnants of this line may
transverse southward into southern Kentucky late tonight, but
instability and wind shear support may decay before the line gets
that far south. Therefore, the highest chances of precipitation
look to be across southern Indiana and portions of northern Kentucky
with lesser chances as one heads southward toward the Tennessee
border. Lows tonight will be milder with readings only cooling into
the upper 50s to the lower 60s.
Slow moving frontal boundary will only drift southward during the
day on Wednesday and likely become quasi-stationary by Wednesday
afternoon. Multiple mid-level impulses will transverse the region
resulting in multiple clusters of convection moving across the
region. In general, the highest probabilities of precipitation for
Wednesday favor southern Indiana and northern Kentucky with lesser
probabilities as one gets down toward the KY/TN border. Overall
convective evolution is very uncertain given the complex mesoscale
processes involved and where boundaries may lay. It is likely that
one or more MCS`s may develop and propagate eastward during the day
and into the evening hours. Severe threat is there with damaging
winds and large hail being the most likely threats. Temperatures
will be tricky, but we have stuck close to the weighted-model
average which results in upper 70s to the lower 80s in the north
with lower 80s across the south. The latest datasets do show some
forecast convergence on a wave approaching the area tomorrow evening
which results in increasing PoP chances for Wednesday night with
this forecast issuance. Lows Wednesday night will be in the 60s.
.Long Term (Thursday through Tuesday)...
Issued at 300 PM EDT Tue Sep 25 2012
Thursday through Friday...
Quasi-stationary front will remain draped east to west across the
Ohio Valley, with a series of upper disturbances riding along it in
zonal flow. Expect intervals of showers and thunderstorms, but these
will be as hard to time as the individual disturbances, so forecast
confidence is quite low.
Path of least regret at this time is to carry chance POPs for most
of the period. As timing becomes more clear on any of the upper
impulses, the POP forecast may be better refined. Temps will run
near normal by day, and above normal by night with abundant cloud
cover. Still plenty of bust potential as any longer episodes of
precip could really limit the diurnal ranges.
Friday night through Tuesday...
Sharp upper trough will dig into eastern Canada and the Great Lakes,
and help to push the front farther south over the weekend. Precip
chances will be suppressed farther into south-central Kentucky
through Saturday night, and then south of the area Sunday into early
next week. Model consensus is coming together with each successive
run, so this is a higher-confidence forecast than Thu-Fri. More of a
polar air mass will knock temperatures slightly below normal, with
highs in the lower/mid 70s and lows in the lower/mid 50s.
&&
.Aviation (00Z TAF Issuance)...
Issued at 650 PM EDT Tue Sep 25 2012
Showers and thunderstorms along a front in southern Indiana will
slowly sink south overnight. This activity has been very slow to
shift southward and have therefore pushed back the timing of VCTS at
SDF and LEX. This activity still looks like it will stay to the
north of BWG both tonight and through much of tomorrow. Will
therefore keep any mention of precipitation out of that TAF. There
will likely be a lull in the rain tomorrow morning until another
upper level disturbance crosses the area tomorrow afternoon,
bringing another round of showers and storms to SDF and LEX.
Winds will decrease to around 6-8 knots overnight out of the south
to southwest. A LLJ will strengthen towards midnight and pivot
across the area. Winds will increase to around 40 knots at 1800-2000
ft. Surface winds will once again increase and become gusty tomorrow.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........EER
Short Term.......MJ
Long Term........RAS
Aviation.........EER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
827 PM EDT TUE SEP 25 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 420 PM EDT TUE SEP 25 2012
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL LOW JUST EAST
OF HUDSON BAY WITH TROUGHING TO THE SOUTH DOMINATING THE GREAT LAKES
AND NE CONUS. AN UPSTREAM SHORTWAVE TROUGH WAS LOCATED NW OF LAKE
SUPERIOR AND HELPED SUPPORT AN INCREASE IN SCT DIURNAL SHOWERS FROM
WINNIPEG TO THUNDER BAY ONTARIO. SOME SPRINKLES HAVE ALSO DEVELOPED
EAST OF THE KEWEENAW AND INTO THE HURON MOUNTAINS WITH THE HELP OF
AFTERNOON HEATING AND WEAK LAKE BREEZES. A WEAK PRES GRADIENT AND
WIND FIELD PREVAILED AS HIGH PRESURE FROM SASK/MANITOBA BUILDS INTO
THE NRN GREAT LAKES.
EXPECT SHRA WILL INCREASE LATE TONIGHT AS 850 MB TEMPS FALL TOWARD
-1C AND A WEAK SFC TROF DROPS S ACROSS THE LAKE IN ASSOCIATION WITH
THE SHORTWAVE. WITH LAKE TEMPS ONLY AROUND 10C TO 13C...DELTA/T
VALUES WILL BE MARGINAL FOR LAKE EFFECT PCPN BUT WILL BE AIDED BY
THE SHRTWV/COLD POOL WITH 700 MB TEMPS ALSO DROPPING TO AROUND
-10C.
THE TIMING OF THE TROF WILL ALSO COINCIDE WITH THE MORE FAVORABLE
MIN OF THE DIURNAL CYCLE. WITH LARGE SCALE SUBSIDENCE WITH DIVERGENT
LOW LEVEL ACYC FLOW AND A SHORTER FETCH...LEFT OUT MENTION OF SHRA
WEST OF THE KEWEENAW. AWAY FROM ANY THICKER CLOUDS AND LAKE
INFLUENCE... TEMPS WILL AGAIN DROP AOB FREEZING IN MANY LOCATIONS
OVER THE INTERIOR WEST. ANY LINGERING SHRA IN THE MORNING INTO THE
ERN CWA FAVORED BY NW FLOW WILL DIMINISH AND END BY AFTERNOON AS THE
SFC RIDGE CONTINUES TO BUILD INTO THE AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 420 PM EDT TUE SEP 25 2012
SPLIT FLOW REGIME TO DOMINATE IN THE UPPER LEVELS THROUGH NEXT
WEEKEND WITH HEIGHTS OVER UPPER LAKES STAYING GENERALLY HIGH. ONE
NOTABLE EXCEPTION IS ECMWF AND TO SOME DEGREE GEM-NHEM STILL SHOW
SHORTWAVE TROUGH SLIDING EAST ACROSS NORTHERN CANADA THIS WEEK THEN
DROPPING INTO NORTHERN ONTARIO ON SATURDAY AND THROUGH THE UPPER
GREAT LAKES BY SUNDAY. ECMWF IS FARTHEST WEST WITH UPPER LOW CENTER
AND SUPPOSE WITH ITS SOLUTION THERE COULD END UP BEING SOME SHOWERS
OVER EASTERN CWA SECOND HALF OF THE WEEKEND. ECMWF HAS SHOWN THIS
FOR FOUR MODEL RUNS NOW...SINCE THE 00Z RUN ON 24 SEPT. GFS REALLY
SHOWS NOTHING OF THE SORT WHILE THE GEM-NHEM IS MORE MIDDLE OF THE
ROAD. CONSENSUS POPS KEEPS THINGS DRY FOR NOW...BUT WENT AHEAD AND
NUDGED CLOUD COVER UP OVER THE EAST LATER SATURDAY THROUGH SUNDAY.
WEAK SHORTWAVE TROUGH SLIDES THROUGH AREA NEXT MONDAY BUT LIMITED
MOISTURE RESULTS IN ONLY SLIGHT CHANCES IN THE FORECAST FOR NOW WITH
THE APPROACH OF A SFC TROUGH. PRIMARY IMPACT COULD BE GUSTY SW WINDS
AHEAD OF THE TROUGH SUNDAY INTO MONDAY.
MAIN WEATHER ISSUE THROUGH THE LONG TERM SEEMS TO BE TEMPERATURES
AND FROST/FREEZE POTENTIAL. NOTE THAT EVEN THOUGH WE HAVE
TECHNICALLY ENDED THE FROST/FREEZE PROGRAM FOR THIS FALL AS MANY
AREAS OVER THE REGION HAVE EXPERIENCED BLO FREEZING TEMPS
RECENTLY...MENTION OF FROST IN THE GRIDS REMAINS IN PLACE THROUGH 30
SEPT.
HIGH PRESSURE RIDGE SETTLES OVER THE UPPER LAKES LATER WEDNESDAY
INTO WEDNESDAY EVENING. HIGHS REMAINS OVERHEAD THROUGH SATURDAY.
GIVEN MOSTLY CLEAR SKIES AND RELATIVELY DRY AIR...EXPECT LARGER
DIURNAL TEMPERATURE SWINGS WITH HIGHS WELL INTO THE 60S AND MINS
DIPPING INTO THE 30S. COLDER EXCEPTION WILL BE WEDNESDAY NIGHT AS
RIDGE AXIS DIRECTLY OVERHEAD AND PWATS AS LOW AS 40 PCT OF NORMAL
SHOULD LEAD TO SIGNIFICANT RADIATIONAL COOLING. TWEAKED MINS WELL
BLO FREEZING OVER INTERIOR CWA /LOW-MID 20S FOR FAVORED INLAND COLD
SPOTS/. LACK OF WIND/LAND BREEZE SHOULD EVEN RESULT IN SOME FROST
FORMING PRETTY CLOSE TO THE GREAT LAKES SHORES. WARMER EXCEPTION MAY
BE ON FRIDAY AS BUBBLE OF WARMER AIR ALOFT MOVES ACROSS OUT AHEAD OF
THE UPPER LOW DROPPING ACROSS ONTARIO. POSSIBLE THAT SOME READINGS
COULD PUSH INTO THE 70S IF ALL BREAKS RIGHT. LOWERED DWPNTS SOME FOR
THURSDAY AFTN AND FRIDAY AFTN AS H85 DWPNT DEPRESSIONS ARE HIGHER
THROUGH THAT TIME. EVEN SO...NO FIRE WEATHER CONCERNS ARE EXPECTED
SINCE WINDS STAY LIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 826 PM EDT TUE SEP 25 2012
COLDER AIR MOVING IN BEHIND A SHRTWV LATER TONIGHT ALONG WITH A
FURTHER INCREASE IN LOW LEVEL MOISTURE SHOULD LOWER CIGS INTO THE
MVFR RANGE. EXPECT MVFR CIGS TO LIFT BY WED AFTERNOON WITH VFR
CONDITIONS THEREAFTER. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EDT TUE SEP 25 2012
HIGH PRES/WEAK PRES GRADIENT WILL GENERALLY DOMINATE FOR THE REST OF
THIS WEEK...RESULTING IN WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
102 PM EDT MON SEP 24 2012
.SYNOPSIS...
ISSUED AT 251 AM EDT MON SEP 24 2012
A SIGNIFICANT CHANGE IN THE WEATHER IS UNDERWAY. INCREASING WINDS
BETWEEN HIGH PRESSURE IN THE OHIO VALLEY AND A COLD FRONT IN FAR
NORTHERN ONTARIO WILL USHER THE COLD AIR OUT OF NORTHERN MICHIGAN
TODAY. SOUTHWEST WINDS WILL BECOME QUITE GUSTY BY AFTERNOON. THE
FRONT WILL CROSS NORTHERN MICHIGAN TONIGHT AND TUESDAY...WITH ONLY A
SMALL CHANCE FOR A FEW SHOWERS. A LARGE AREA OF HIGH PRESSURE WILL
MOVE INTO THE REGION LATE THIS WEEK AND INTO THE WEEKEND...PROVIDING
QUITE WEATHER.
&&
.UPDATE...
ISSUED AT 102 PM EDT MON SEP 24 2012
WINDY CONDITIONS CONTINUE ALL THROUGHOUT THE AREA...WITH THE CORE
OF STRONGEST LOW LEVEL WINDS JUST NOW ARRIVING. GOING WIND
ADVISORY LOOKS JUST FINE...WITH SOME REPORTS OF GUSTS NEARING 45
MPH THE PAST HOUR ALONG THE LAKE MICHIGAN SHORELINE. AS THEORIZED
EARLIER...THICKER CIRRUS IS HAVING SOME IMPACT ON TEMPS THUS
FAR...BUT IS SHOWING SIGNS OF THINNING WITH TIME. IN ADDITION...
STEADY WARM ADVECTION WILL CONTINUE UP THROUGH 00Z AND GOING HIGHS
INTO THE LOW/MID 60S SHOULD WORK OUT WELL. STILL WATCHING A BAND
OF LIGHT SHOWERS DROPPING SOUTH OVER EASTERN LAKE SUPERIOR...AND
SUSPECT THIS WILL CONTINUE ITS TRAJECTORY INTO EARLY EVENING.
CLOUD BASES ARE RATHER HIGH (UP AROUND 8KFT)...BUT COULD SEE
ENOUGH TO WET THE GROUND IN A FEW SPOTS NORTH OF M-32.
UPDATE ISSUED AT 1014 AM EDT MON SEP 24 2012
GOING FCST LOOKS TO BE IN PRETTY GOOD SHAPE INTO THE AFTERNOON.
EARLIER CALL TO RAISE CLOUD COVER WORKING OUT WELL PER VISIBLE
SATELLITE TRENDS...WITH THE THICKEST CLOUD COVER ROUGHLY ALONG/
NORTH OF M-32...WHERE THICKER MID CLOUDS ARE SET TO INVADE FROM
ABOUT 18-21Z. PER RADAR TRENDS...HAVE ALSO BUMPED POPS TO LIKELY
FOR A TIME ACROSS MAINLY EASTERN UPPER/TIP OF THE MITT. AMPLIFYING
UPPER WAVE AND ASSOCIATED SHOT OF 850-500MB Q-VECTOR IS WORKING IN
COMBINATION WITH A NARROW MOISTURE AXIS AND NO DOUBT A LITTLE HELP
OFF LAKE SUPERIOR TO KICK OFF SOME SHOWERS CURRENTLY AS OF 14Z.
WITH FURTHER AMPLIFICATION OF THE UPPER FEATURE AND LOW LEVEL
FRONTAL CONVERGENCE AS A COLD FRONT DROPS INTO THE AREA...HAVE
LITTLE TROUBLE BELIEVING SOME OF THIS ACTIVITY WILL SURVIVE. SREF
PROGS HAVE BEEN STRONGLY HINTING AT THIS FOR THE PAST FEW DAYS AND
HAVE LITTLE ROOM TO ARGUE GIVEN CURRENT CONDITIONS. HAVE ALSO
LOWERED GOING HIGHS A COUPLE OF DEGREES BENEATH THICKER CLOUD
COVER...MAINLY NORTH OF M-72. WITH THAT SAID...DEEP MIXING WILL
STILL PROPEL US WELL ABOVE THE VERY CHILLY CONDITIONS EXPERIENCED
THIS WEEKEND.
ON THE WATER...WINDS ALREADY RAMPING UP NICELY...WITH QUITE A FEW
GUSTS IN EXCESS OF 30-35 KNOTS. CORE OF STRONGEST WINDS STILL ON
TRACK TO ARRIVE ROUGHLY 18-00Z...WITH AN IMPRESSIVE 50 KNOTS DOWN
TO 950MB...BACKED UP BY 12Z RAOB FROM INTERNATIONAL FALLS SHOWING
50 KNOTS DOWN TO 925MB! DEFINITE GALES ACROSS ALL THE WATERS...
STRONGEST OVER LAKE MICHIGAN...WHERE COULD PERHAPS SEE A FEW GUSTS
UP TO 45 KNOTS.
UPDATE ISSUED AT 830 AM EDT MON SEP 24 2012
QUICK UPDATE TO DROP THE AX ON THE CURRENT FROST ADVISORY. MOST
SPOTS ARE WELL ABOVE FREEZING AS OF 815 AM...AND WILL ONLY
CONTINUE TO CLIMB AT MIXING DEEPENS THE NEXT FEW HOURS. HAVE ALSO
RAISED CLOUD COVER SIGNIFICANTLY FROM ABOUT M-72 ON NORTH THROUGH
THE DAY. CURRENT SATELLITE IMAGERY (THOUGH HINDERED BY GOES-13
OUTAGE) ALONG WITH SHORT TERM GUIDANCE TRENDS SUPPORT A ROUND OF
QUITE THICK WARM ADVECTION-DRIVEN CIRRUS PUSHING THROUGH THE AREA
INTO EARLY AFTERNOON...ONLY TO BE FOLLOWED BY A NICE PUSH OF MID
LEVEL RH OUT AHEAD OF AN AMPLIFYING UPPER WAVE DROPPING INTO LAKE
SUPERIOR. DON`T THINK THE ADDED CLOUD COVER WILL HAVE TOO MUCH
EFFECT ON HIGH TEMPS GIVEN EXPECTED DEEP TURBULENT MIXING INTO A
STEADILY WARMING AIRMASS ALOFT...BUT MAY ULTIMATELY NEED TO CHOP
OFF A DEGREE OR TWO WITH FUTURE UPDATES. GOING GALE/WIND ADVISORY
HEADLINES LOOK JUST FINE. CERTAINLY A QUITE WINDY DAY IN ALL
AREAS.
UPDATE ISSUED AT 658 AM EDT MON SEP 24 2012
CIRRUS IS EXPANDING FROM THE NW...AND IS CURRENTLY QUITE THICK
ALONG/NORTH OF M-68. CLOUD COVER HAS BEEN ADJUSTED ACCORDINGLY.
WARMER AIR IS POISED TO SWOOP IN FROM LAKE MI AS WINDS RECOUPLE
(MANISTEE HARBOR C-MAN SITE IS 55F PRESENTLY...WHILE A FEW MILES
INLAND MBL AIRPORT IS 32).
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 251 AM EDT MON SEP 24 2012
DEFINITE SIGNS OF CHANGE ACROSS THE NORTH WOODS EARLY THIS
MORNING...WITH CORE OF COLD ANOMALIES AND CENTER OF TROUGH AXIS THAT
HAS PLAGUED THE REGION FOR THE LAST SEVERAL DAYS NOW ROTATING OFF TO
OUR NORTHEAST. NO DOUBT TROUGHING STILL DOMINATES...BUT OFF THE DECK
WAA ALREADY BEGINNING TO REAR ITS HEAD ON NORTH SIDE OF SURFACE HIGH
PRESSURE ROTATING THROUGH THE OHIO VALLEY. DECREASING OVER-WATER
INSTABILITY VIA SLIGHT WARMING H85 TEMPERATURES (UP TO NEAR 0C PER
LATEST HIGH RES RAP GUIDANCE) AND ONSLAUGHT OF DEEP LAYER DRYING
(H85 NEGATIVE UPPER SINGLE DIGIT DEWPOINTS OVER NORTHERN LAKE
MICHIGAN) HAS NOT ONLY ESSENTIALLY SHUT OFF THE LAKE INDUCED SHOWER
MACHINE...BUT PUT A SERIOUS DENT IN EVEN LAKE CLOUD FORMATION.
THUS...SKIES HAVE CONTINUED TO CLEAR ACROSS MUCH OF OUR AREA...
ALTHOUGH HIGH CLOUDS HAVE BEGUN TO FILTER INTO UPPER MICHIGAN ON
FRONT END OF STRONG UPPER LEVEL JET STREAK AND ATTENDANT MID LEVEL
WAVE ROTATING SOUTH OUT OF WESTERN ONTARIO. COMBO OF CLEARING SKIES
AND QUICK LOSS OF WINDS THIS EVENING HAS ALLOWED TEMPERATURES TO
TANK...WITH READINGS ALREADY DIPPING WELL INTO THE 30S ACROSS
INTERIOR REGIONS SOUTH OF THE MIGHTY MAC. LIGHT WINDS WILL BE A
SHORT EVENT...WITH ALREADY SIGNS OF INCREASING WINDS OFF THE SURFACE
PER LATEST GUIDANCE. THIS IS JUST A BEGINNING OF THINGS TO COME...
WITH STRONG PRESSURE GRADIENT AND APPROACHING UPPER JET CORE ONLY
ENHANCING DOWN LOW WIND RESPONSE...FIRST OVER THE BIG WATERS BY
MORNING...AND ACROSS ALL AREAS AFTER SUNRISE. PRIMARY FORECAST
CONCERNS CENTER ON WIND SPEEDS AND ASSOCIATED POTENTIAL
HEADLINES...WITH LOW END SHOWER THREAT FROM APPROACHING EARLIER
MENTIONED WAVE A SECONDARY CONCERN.
FIRST THINGS FIRST...AND WILL LET FROST ADVISORY RUN ITS COURSE
THROUGH THE EARLY MORNING...WITH CURRENT TEMPERATURE TRENDS
SUPPORTING LOWS BY SUNRISE DIPPING INTO THE LOWER 30S IN THE
TRADITIONAL ICE BOX LOCATIONS. OTHERWISE...BIGGEST STORY TODAY WILL
BE THE WINDS...WHICH RAMP-UP QUICKLY THIS MORNING AS LOW LEVEL JET
INTENSIFIES OVERHEAD...WITH 950MB WINDS PUSHING 30 TO 40 KNOTS BY
18Z...WITH SPEEDS PUSHING 45 KNOTS UP THROUGH NORTHERN LAKE MICHIGAN
AND THE STRAITS. DESPITE WAA REGIME...GUIDANCE REMAINS STEADFAST OF
GOOD MIXING WELL PAST THIS LAYER...UP TO 850MBS...ESPECIALLY OVER
THE BIG WATERS WHERE CONDITIONS WILL REMAIN SOMEWHAT UNSTABLE.
BUFKIT MOMENTUM TRANSFER PROGS SUGGEST A GOOD PORTION OF ELEVATED
WINDS WILL MIX DOWN...SUPPORTING WIDESPREAD WIND GUSTS BY EARLY
AFTERNOON PUSHING 30 TO 35 MPH OVER MOST INTERIOR REGIONS. BIGGEST
CONCERN REMAINS UP ALONG THE NORTHWEST LOWER COASTLINE AND IN THE
STRAITS REGION WHERE CORE OF JET AND INSTABILITY IS MAXIMIZED OVER
OPEN WATER. COULD EASILY SEE 45 MPH GUSTS ALONG THE IMMEDIATE COASTS
FROM LEELANAU COUNTY UP INTO MACKINAC COUNTY...INCLUDING BEAVER
ISLAND. WILL GO AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY FOR
THESE AREAS FROM LATE MORNING RIGHT THROUGH THE AFTERNOON HOURS.
SHOULD BE BELOW ADVISORY LEVELS ELSEWHERE...ALTHOUGH DO HAVE SOME
CONCERN FOR NORTHWEST BENZIE COUNTY AS WELL AS THE IMMEDIATE
SHORELINE OF IOSCO COUNTY OVER NORTHEAST LOWER AS WINDS FUNNEL UP
SAGINAW BAY. WILL HOLD OFF FOR THESE AREAS...BUT DEFINITELY PASS
THIS CONCERN ON TO THE INCOMING CREW.
OTHER STORY TODAY WILL BE LATE DAY RAIN CHANCES ACROSS EASTERN UPPER
AND THE TIP OF THE MITT AS ONTARIO WAVE AND ATTENDANT COLD FRONT
DROP INTO THE AREA. DYNAMICS NOT TOO SHABBY...WITH GOOD CORE OF MID
LEVEL -DIVQ OVERTOPPING DECENT BAND OF LOW LEVEL CONVERGENCE. LACK
OF MOISTURE REMAINS A BIG DETERRENT TO RAIN POTENTIAL...WITH
PRE-FRONTAL MOISTURE ADVECTION ANEMIC AT BEST...AS H85 DEWPOINTS
ONLY APPROACH 1C. GIVEN ABOVE...WILL MAKE LITTLE CHANGE TO INHERITED
LATE DAY LOW END POPS ACROSS THE FAR NORTH. GUSTY SOUTHWEST WINDS
WORK THEIR MAGIC...TACKING ON A GOOD 10 TO 15 DEGREES TO HIGH
TEMPERATURES EXPERIENCED THE LAST COUPLE DAYS. LOOK FOR AFTERNOON
READINGS ACTUALLY PUSHING LEVELS MUCH CLOSER TO NORMAL...WITH HIGHS
WELL INTO THE 60S!
FRONT SLOWLY SAGS SOUTH THROUGH THE OVERNIGHT AS MID LEVEL SUPPORT
BEGINS TO SHEAR OUT. MOISTURE PROFILES CHANGE LITTLE...WITH JUST A
NARROW AND RELATIVELY LIMITED SLUG OF MOISTURE ACCOMPANYING THE
FRONT. CAN`T ENTIRELY RULE OUT A LIGHT SHOWER...BUT FEEL MOST AREAS
AND MOST OF THE TIME WILL REMAIN DRY. WINDS DECREASE SUBSTANTIALLY
THROUGH THE EVENING AS MIXING IS LOST AND LOW LEVEL JET PIVOTS OFF
TO THE EAST. A MILD OVERNIGHT COMPARED TO RECENT TIMES...WITH LOWS
ONLY DROPPING INTO THE 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 251 AM EDT MON SEP 24 2012
A RELATIVELY UNEVENTFUL WORK WEEK IS AHEAD...AS THE UPPER FLOW OVER
THE CONUS AND SOUTHERN CANADA DEAMPLIFIES SOMEWHAT. THE UPPER LOW
OVER NORTHERN QUEBEC WILL EJECT NE-WARD TOWARD MID-WEEK...THOUGH IT
WILL DRAG ONE LAST UPPER TROF ACROSS THE LAKES REGION ON WEDNESDAY.
BUT BY THEN...A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED OVER
THE WESTERN LAKES. THE COLD FRONT TALKED ABOUT IN THE SHORT-TERM
SECTION ABOVE...WILL SLOWLY MOVE SOUTH OF NORTHERN MI TUESDAY AND
TUE NIGHT.
TUESDAY...COLD FRONT WILL START THE MORNING ALONG ROUGHLY AN LDM-APN
LINE...WITH A WEAK SURFACE WAVE NEAR LDM. THE WAVE...AND THUS THE
FRONT...WILL GET HELD UP AS THEY BOTH FEEL A PROMINENT SHORTWAVE
DIGGING TOWARD NORTHERN SUPERIOR BY THE END OF THE DAY. AT THAT
TIME...THE FRONT WILL BE JUST OUT OF SE SECTIONS OF THE FORECAST
AREA....WITH THE SURFACE WAVE OVER SAGINAW BAY. BEHIND THE FRONT...A
SURFACE RIDGE AXIS WILL POKE EASTWARD ACROSS UPPER MI AND SOUTHERN
SUPERIOR.
THE SURFACE WAVE...AND LOCALLY BACKED FLOW OFF OF LAKE HURON...WILL
PRODUCE A PROMINENT AREA OF 1000-850MB CONVERGENCE...ALONG AND SE OF
AN APN-HTL LINE. HOWEVER...EVEN IF SURFACE DEW POINTS GET BOOSTED TO
50F IN THIS AREA PER NAM SOUNDINGS (AND FOR NOW EVEN THAT LOOKS
OPTIMISTIC)...UPDRAFTS WILL BE CAPPED OFF AT 625MB/-5C. NO ICE
EXPECTED IN THESE CLOUDS...AND NOT SURE THAT PRECIP GENERATED VIA
WARM RAIN PROCESSES WILL GET THRU THE RELATIVELY DRY AIR BELOW CLOUD
BASE/825MB. MUCAPE ONLY TOPS OUT AT 100J/KG. WILL MODIFY PRECIP
WORDING SLIGHTLY...GOING WITH A SMALL CHANCE FOR SPRINKLES (INSTEAD
OF OUTRIGHT SHOWERS) IN THE AFTERNOON IN PARTS OF NE LOWER.
ELSEWHERE...SCT DIURNAL CU AND/OR LAKE STRATOCU WILL BE PRESENT
(POST-FRONTAL DELTA T/S NEAR 15C OFF OF SUPERIOR AND FAR NORTHERN
LOWER LAKE MI). MAX TEMPS WILL RANGE FROM UPPER 50S IN EASTERN UPPER
MI...TO THE LOWER 70S IN THE FAR SE.
TUE NIGHT/WEDNESDAY...COLD FRONT MOVES TO FAR SOUTHERN LOWER MI BY
WED MORNING. HIGH PRESSURE MOVES FROM CENTRAL CANADA EARLY TUESDAY
NIGHT...TO WESTERN UPPER MI BY WED EVENING. THE BUILDING HIGH WILL
PROVIDE QUIET WX FOR MOST OF NORTHERN MI. HOWEVER...WE MAY SEE SOME
PRECIP CHANCES EMERGE UP NEAR SUPERIOR. A DIGGING SHORTWAVE REACHES
SUPERIOR WED MORNING. LOW LEVEL COLD ADVECTION CONTINUES...WITH
850MB TEMPS LOWERING NEAR 0C. A SURFACE TROF AXIS WILL AID
CONVERGENCE AND MOISTURE POOLING BELOW THE 725MB INVERSION. WILL ADD
A CHANCE OF SHRA TO PARTS OF CHIPPEWA CO LATE TUE NIGHT AND
ESPECIALLY WED MORNING. ELSEWHERE...MOSTLY CLEAR TO PARTLY CLOUDY
SKIES WILL WAY TO A HEALTHY CU FIELD BY EARLY AFTERNOON WED. MIN
TEMPS UPPER 30S TO LOWER 40S. MAX TEMPS MIDDLE 50S TO LOWER 60S.
REST OF THE FORECAST...EXTENDED MODELS AGREE THAT THE HIGH PRESSURE
IN PLACE BY WED NIGHT WILL BE DIFFICULT TO DISLODGE. IN FACT...IT
LOOKS TO BE REINFORCED OUT TOWARD FRIDAY. A DYING COLD FRONT MAY TRY
TO MOVE IN THURSDAY NIGHT AHEAD OF THE NEXT HIGH...BUT IT HAS NO
MOISTURE TO WORK WITH...AND ANY SORT OF DYNAMICS ARE UP TOWARD JAMES
BAY. THE EXTENDED WILL BE DEVOID OF ANY PRECIP. BELOW-NORMAL TEMPS
ON THURSDAY WILL MODERATE CLOSER TO NORMAL FOR THE WEEKEND.
WEDNESDAY NIGHT STILL LOOKS TO HAVE CONSIDERABLE FROST POTENTIAL IN
THE USUAL INLAND LOCALES...THE FORECAST WILL CONTINUE TO REFLECT
THIS. THURSDAY NIGHT COULD ALSO HAVE SOME FROST CONCERNS...THOUGH
LIKELY NOT AS MANY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 102 PM EDT MON SEP 24 2012
VFR THROUGH THE TAF PERIOD. VERY GUSTY SOUTHWEST WINDS WILL
CONTINUE AT ALL TERMINAL SITES THROUGH EARLY EVENING...OUT AHEAD
OF AN APPROACHING UPPER TROUGH AND COLD FRONT. THAT FEATURE WILL
BRING WITH IS SCATTERED HIGH-BASED SHOWERS THAT MAY BRIEFLY IMPACT
THE PLN/APN TERMINALS...BUT WITH NO REDUCTIONS TO VISBY/CIG
EXPECTED. WINDS WILL DIMINISH QUICKLY INTO THE LATE EVENING AS THE
FRONT SLIPS THROUGH...BUT NOT BEFORE A BRIEF PERIOD OF LOW LEVEL
WIND SHEAR IMPACTS MUCH OF THE AREA. LIGHT AND VARIABLE WINDS ARE
THEN EXPECTED INTO THE DAY ON TUESDAY...WITH SOME AFTERNOON
CUMULUS ALSO EXPECTED TO DEVELOP.
&&
.MARINE...
ISSUED AT 251 AM EDT MON SEP 24 2012
PRESSURE GRADIENT TIGHTENS THROUGH THE DAY AHEAD OF A COLD
FRONT THAT WILL SLIP THROUGH THE AREA TONIGHT. WITH REMAINING OVER
WATER INSTABILITY...VERY GUSTY WINDS WILL DEVELOP THIS MORNING AND
THROUGH THE AFTERNOON. GALE FORCE GUSTS ARE CERTAIN ON THE LAKE
MICHIGAN NEARSHORE AREAS AND THROUGH THE STRAITS. LESS CERTAINTY FOR
REACHING GALE FORCE ON THE LAKE HURON SIDE AS WELL AS WHITEFISH
BAY/SAINT MARYS RIVER. BUT GUSTINESS OVER LAND WILL LIKELY EXTEND
OUT INTO THE WATER...AND WILL THUS CONTINUE INHERITED GALE WARNINGS
FOR ALL NEARSHORE ZONES INTO TONIGHT. CONDITIONS WILL IMPROVE
THROUGH THE OVERNIGHT...WITH GALES LIKELY ENDING ALL AREAS WELL
BEFORE SUNRISE.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ015-016-019-020.
LH...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LHZ345>349.
LM...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LMZ323-341-342-344>346.
LS...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...LAWRENCE
MARINE...BA/MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1014 AM EDT MON SEP 24 2012
.SYNOPSIS...
ISSUED AT 251 AM EDT MON SEP 24 2012
A SIGNIFICANT CHANGE IN THE WEATHER IS UNDERWAY. INCREASING WINDS
BETWEEN HIGH PRESSURE IN THE OHIO VALLEY AND A COLD FRONT IN FAR
NORTHERN ONTARIO WILL USHER THE COLD AIR OUT OF NORTHERN MICHIGAN
TODAY. SOUTHWEST WINDS WILL BECOME QUITE GUSTY BY AFTERNOON. THE
FRONT WILL CROSS NORTHERN MICHIGAN TONIGHT AND TUESDAY...WITH ONLY A
SMALL CHANCE FOR A FEW SHOWERS. A LARGE AREA OF HIGH PRESSURE WILL
MOVE INTO THE REGION LATE THIS WEEK AND INTO THE WEEKEND...PROVIDING
QUITE WEATHER.
&&
.UPDATE...
ISSUED AT 1014 AM EDT MON SEP 24 2012
GOING FCST LOOKS TO BE IN PRETTY GOOD SHAPE INTO THE AFTERNOON.
EARLIER CALL TO RAISE CLOUD COVER WORKING OUT WELL PER VISIBLE
SATELLITE TRENDS...WITH THE THICKEST CLOUD COVER ROUGHLY ALONG/
NORTH OF M-32...WHERE THICKER MID CLOUDS ARE SET TO INVADE FROM
ABOUT 18-21Z. PER RADAR TRENDS...HAVE ALSO BUMPED POPS TO LIKELY
FOR A TIME ACROSS MAINLY EASTERN UPPER/TIP OF THE MITT. AMPLIFYING
UPPER WAVE AND ASSOCIATED SHOT OF 850-500MB Q-VECTOR IS WORKING IN
COMBINATION WITH A NARROW MOISTURE AXIS AND NO DOUBT A LITTLE HELP
OFF LAKE SUPERIOR TO KICK OFF SOME SHOWERS CURRENTLY AS OF 14Z.
WITH FURTHER AMPLIFICATION OF THE UPPER FEATURE AND LOW LEVEL
FRONTAL CONVERGENCE AS A COLD FRONT DROPS INTO THE AREA...HAVE
LITTLE TROUBLE BELIEVING SOME OF THIS ACVITITY WILL SURVIVE. SREF
PROGS HAVE BEEN STRONGLY HINTING AT THIS FOR THE PAST FEW DAYS AND
HAVE LITTLE ROOM TO ARGUE GIVEN CURRENT CONDITIONS. HAVE ALSO
LOWERED GOING HIGHS A COUPLE OF DEGREES BENEATH THICKER CLOUD
COVER...MAINLY NORTH OF M-72. WITH THAT SAID...DEEP MIXING WILL
STILL PROPEL US WELL ABOVE THE VERY CHILLY CONDITIONS EXPERIENCED
THIS WEEKEND.
ON THE WATER...WINDS ALREADY RAMPING UP NICELY...WITH QUITE A FEW
GUSTS IN EXCESS OF 30-35 KNOTS. CORE OF STRONGEST WINDS STILL ON
TRACK TO ARRIVE ROUGHLY 18-00Z...WITH AN IMPRESSIVE 50 KNOTS DOWN
TO 950MB...BACKED UP BY 12Z RAOB FROM INTERNATIONAL FALLS SHOWING
50 KNOTS DOWN TO 925MB! DEFINITE GALES ACROSS ALL THE WATERS...
STRONGEST OVER LAKE MICHIGAN...WHERE COULD PERHAPS SEE A FEW GUSTS
UP TO 45 KNOTS.
UPDATE ISSUED AT 830 AM EDT MON SEP 24 2012
QUICK UPDATE TO DROP THE AX ON THE CURRENT FROST ADVISORY. MOST
SPOTS ARE WELL ABOVE FREEZING AS OF 815 AM...AND WILL ONLY
CONTINUE TO CLIMB AT MIXING DEEPENS THE NEXT FEW HOURS. HAVE ALSO
RAISED CLOUD COVER SIGNIFICANTLY FROM ABOUT M-72 ON NORTH THROUGH
THE DAY. CURRENT SATELLITE IMAGERY (THOUGH HINDERED BY GOES-13
OUTAGE) ALONG WITH SHORT TERM GUIDANCE TRENDS SUPPORT A ROUND OF
QUITE THICK WARM ADVECTION-DRIVEN CIRRUS PUSHING THROUGH THE AREA
INTO EARLY AFTERNOON...ONLY TO BE FOLLOWED BY A NICE PUSH OF MID
LEVEL RH OUT AHEAD OF AN AMPLIFYING UPPER WAVE DROPPING INTO LAKE
SUPERIOR. DON`T THINK THE ADDED CLOUD COVER WILL HAVE TOO MUCH
EFFECT ON HIGH TEMPS GIVEN EXPECTED DEEP TURBULENT MIXING INTO A
STEADILY WARMING AIRMASS ALOFT...BUT MAY ULTIMATELY NEED TO CHOP
OFF A DEGREE OR TWO WITH FUTURE UPDATES. GOING GALE/WIND ADVISORY
HEADLINES LOOK JUST FINE. CERTAINLY A QUITE WINDY DAY IN ALL
AREAS.
UPDATE ISSUED AT 658 AM EDT MON SEP 24 2012
CIRRUS IS EXPANDING FROM THE NW...AND IS CURRENTLY QUITE THICK
ALONG/NORTH OF M-68. CLOUD COVER HAS BEEN ADJUSTED ACCORDINGLY.
WARMER AIR IS POISED TO SWOOP IN FROM LAKE MI AS WINDS RECOUPLE
(MANISTEE HARBOR C-MAN SITE IS 55F PRESENTLY...WHILE A FEW MILES
INLAND MBL AIRPORT IS 32).
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 251 AM EDT MON SEP 24 2012
DEFINITE SIGNS OF CHANGE ACROSS THE NORTH WOODS EARLY THIS
MORNING...WITH CORE OF COLD ANOMALIES AND CENTER OF TROUGH AXIS THAT
HAS PLAGUED THE REGION FOR THE LAST SEVERAL DAYS NOW ROTATING OFF TO
OUR NORTHEAST. NO DOUBT TROUGHING STILL DOMINATES...BUT OFF THE DECK
WAA ALREADY BEGINNING TO REAR ITS HEAD ON NORTH SIDE OF SURFACE HIGH
PRESSURE ROTATING THROUGH THE OHIO VALLEY. DECREASING OVER-WATER
INSTABILITY VIA SLIGHT WARMING H85 TEMPERATURES (UP TO NEAR 0C PER
LATEST HIGH RES RAP GUIDANCE) AND ONSLAUGHT OF DEEP LAYER DRYING
(H85 NEGATIVE UPPER SINGLE DIGIT DEWPOINTS OVER NORTHERN LAKE
MICHIGAN) HAS NOT ONLY ESSENTIALLY SHUT OFF THE LAKE INDUCED SHOWER
MACHINE...BUT PUT A SERIOUS DENT IN EVEN LAKE CLOUD FORMATION.
THUS...SKIES HAVE CONTINUED TO CLEAR ACROSS MUCH OF OUR AREA...
ALTHOUGH HIGH CLOUDS HAVE BEGUN TO FILTER INTO UPPER MICHIGAN ON
FRONT END OF STRONG UPPER LEVEL JET STREAK AND ATTENDANT MID LEVEL
WAVE ROTATING SOUTH OUT OF WESTERN ONTARIO. COMBO OF CLEARING SKIES
AND QUICK LOSS OF WINDS THIS EVENING HAS ALLOWED TEMPERATURES TO
TANK...WITH READINGS ALREADY DIPPING WELL INTO THE 30S ACROSS
INTERIOR REGIONS SOUTH OF THE MIGHTY MAC. LIGHT WINDS WILL BE A
SHORT EVENT...WITH ALREADY SIGNS OF INCREASING WINDS OFF THE SURFACE
PER LATEST GUIDANCE. THIS IS JUST A BEGINNING OF THINGS TO COME...
WITH STRONG PRESSURE GRADIENT AND APPROACHING UPPER JET CORE ONLY
ENHANCING DOWN LOW WIND RESPONSE...FIRST OVER THE BIG WATERS BY
MORNING...AND ACROSS ALL AREAS AFTER SUNRISE. PRIMARY FORECAST
CONCERNS CENTER ON WIND SPEEDS AND ASSOCIATED POTENTIAL
HEADLINES...WITH LOW END SHOWER THREAT FROM APPROACHING EARLIER
MENTIONED WAVE A SECONDARY CONCERN.
FIRST THINGS FIRST...AND WILL LET FROST ADVISORY RUN ITS COURSE
THROUGH THE EARLY MORNING...WITH CURRENT TEMPERATURE TRENDS
SUPPORTING LOWS BY SUNRISE DIPPING INTO THE LOWER 30S IN THE
TRADITIONAL ICE BOX LOCATIONS. OTHERWISE...BIGGEST STORY TODAY WILL
BE THE WINDS...WHICH RAMP-UP QUICKLY THIS MORNING AS LOW LEVEL JET
INTENSIFIES OVERHEAD...WITH 950MB WINDS PUSHING 30 TO 40 KNOTS BY
18Z...WITH SPEEDS PUSHING 45 KNOTS UP THROUGH NORTHERN LAKE MICHIGAN
AND THE STRAITS. DESPITE WAA REGIME...GUIDANCE REMAINS STEADFAST OF
GOOD MIXING WELL PAST THIS LAYER...UP TO 850MBS...ESPECIALLY OVER
THE BIG WATERS WHERE CONDITIONS WILL REMAIN SOMEWHAT UNSTABLE.
BUFKIT MOMENTUM TRANSFER PROGS SUGGEST A GOOD PORTION OF ELEVATED
WINDS WILL MIX DOWN...SUPPORTING WIDESPREAD WIND GUSTS BY EARLY
AFTERNOON PUSHING 30 TO 35 MPH OVER MOST INTERIOR REGIONS. BIGGEST
CONCERN REMAINS UP ALONG THE NORTHWEST LOWER COASTLINE AND IN THE
STRAITS REGION WHERE CORE OF JET AND INSTABILITY IS MAXIMIZED OVER
OPEN WATER. COULD EASILY SEE 45 MPH GUSTS ALONG THE IMMEDIATE COASTS
FROM LEELANAU COUNTY UP INTO MACKINAC COUNTY...INCLUDING BEAVER
ISLAND. WILL GO AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY FOR
THESE AREAS FROM LATE MORNING RIGHT THROUGH THE AFTERNOON HOURS.
SHOULD BE BELOW ADVISORY LEVELS ELSEWHERE...ALTHOUGH DO HAVE SOME
CONCERN FOR NORTHWEST BENZIE COUNTY AS WELL AS THE IMMEDIATE
SHORELINE OF IOSCO COUNTY OVER NORTHEAST LOWER AS WINDS FUNNEL UP
SAGINAW BAY. WILL HOLD OFF FOR THESE AREAS...BUT DEFINITELY PASS
THIS CONCERN ON TO THE INCOMING CREW.
OTHER STORY TODAY WILL BE LATE DAY RAIN CHANCES ACROSS EASTERN UPPER
AND THE TIP OF THE MITT AS ONTARIO WAVE AND ATTENDANT COLD FRONT
DROP INTO THE AREA. DYNAMICS NOT TOO SHABBY...WITH GOOD CORE OF MID
LEVEL -DIVQ OVERTOPPING DECENT BAND OF LOW LEVEL CONVERGENCE. LACK
OF MOISTURE REMAINS A BIG DETERRENT TO RAIN POTENTIAL...WITH
PRE-FRONTAL MOISTURE ADVECTION ANEMIC AT BEST...AS H85 DEWPOINTS
ONLY APPROACH 1C. GIVEN ABOVE...WILL MAKE LITTLE CHANGE TO INHERITED
LATE DAY LOW END POPS ACROSS THE FAR NORTH. GUSTY SOUTHWEST WINDS
WORK THEIR MAGIC...TACKING ON A GOOD 10 TO 15 DEGREES TO HIGH
TEMPERATURES EXPERIENCED THE LAST COUPLE DAYS. LOOK FOR AFTERNOON
READINGS ACTUALLY PUSHING LEVELS MUCH CLOSER TO NORMAL...WITH HIGHS
WELL INTO THE 60S!
FRONT SLOWLY SAGS SOUTH THROUGH THE OVERNIGHT AS MID LEVEL SUPPORT
BEGINS TO SHEAR OUT. MOISTURE PROFILES CHANGE LITTLE...WITH JUST A
NARROW AND RELATIVELY LIMITED SLUG OF MOISTURE ACCOMPANYING THE
FRONT. CAN`T ENTIRELY RULE OUT A LIGHT SHOWER...BUT FEEL MOST AREAS
AND MOST OF THE TIME WILL REMAIN DRY. WINDS DECREASE SUBSTANTIALLY
THROUGH THE EVENING AS MIXING IS LOST AND LOW LEVEL JET PIVOTS OFF
TO THE EAST. A MILD OVERNIGHT COMPARED TO RECENT TIMES...WITH LOWS
ONLY DROPPING INTO THE 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 251 AM EDT MON SEP 24 2012
A RELATIVELY UNEVENTFUL WORK WEEK IS AHEAD...AS THE UPPER FLOW OVER
THE CONUS AND SOUTHERN CANADA DEAMPLIFIES SOMEWHAT. THE UPPER LOW
OVER NORTHERN QUEBEC WILL EJECT NE-WARD TOWARD MID-WEEK...THOUGH IT
WILL DRAG ONE LAST UPPER TROF ACROSS THE LAKES REGION ON WEDNESDAY.
BUT BY THEN...A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED OVER
THE WESTERN LAKES. THE COLD FRONT TALKED ABOUT IN THE SHORT-TERM
SECTION ABOVE...WILL SLOWLY MOVE SOUTH OF NORTHERN MI TUESDAY AND
TUE NIGHT.
TUESDAY...COLD FRONT WILL START THE MORNING ALONG ROUGHLY AN LDM-APN
LINE...WITH A WEAK SURFACE WAVE NEAR LDM. THE WAVE...AND THUS THE
FRONT...WILL GET HELD UP AS THEY BOTH FEEL A PROMINENT SHORTWAVE
DIGGING TOWARD NORTHERN SUPERIOR BY THE END OF THE DAY. AT THAT
TIME...THE FRONT WILL BE JUST OUT OF SE SECTIONS OF THE FORECAST
AREA....WITH THE SURFACE WAVE OVER SAGINAW BAY. BEHIND THE FRONT...A
SURFACE RIDGE AXIS WILL POKE EASTWARD ACROSS UPPER MI AND SOUTHERN
SUPERIOR.
THE SURFACE WAVE...AND LOCALLY BACKED FLOW OFF OF LAKE HURON...WILL
PRODUCE A PROMINENT AREA OF 1000-850MB CONVERGENCE...ALONG AND SE OF
AN APN-HTL LINE. HOWEVER...EVEN IF SURFACE DEW POINTS GET BOOSTED TO
50F IN THIS AREA PER NAM SOUNDINGS (AND FOR NOW EVEN THAT LOOKS
OPTIMISTIC)...UPDRAFTS WILL BE CAPPED OFF AT 625MB/-5C. NO ICE
EXPECTED IN THESE CLOUDS...AND NOT SURE THAT PRECIP GENERATED VIA
WARM RAIN PROCESSES WILL GET THRU THE RELATIVELY DRY AIR BELOW CLOUD
BASE/825MB. MUCAPE ONLY TOPS OUT AT 100J/KG. WILL MODIFY PRECIP
WORDING SLIGHTLY...GOING WITH A SMALL CHANCE FOR SPRINKLES (INSTEAD
OF OUTRIGHT SHOWERS) IN THE AFTERNOON IN PARTS OF NE LOWER.
ELSEWHERE...SCT DIURNAL CU AND/OR LAKE STRATOCU WILL BE PRESENT
(POST-FRONTAL DELTA T/S NEAR 15C OFF OF SUPERIOR AND FAR NORTHERN
LOWER LAKE MI). MAX TEMPS WILL RANGE FROM UPPER 50S IN EASTERN UPPER
MI...TO THE LOWER 70S IN THE FAR SE.
TUE NIGHT/WEDNESDAY...COLD FRONT MOVES TO FAR SOUTHERN LOWER MI BY
WED MORNING. HIGH PRESSURE MOVES FROM CENTRAL CANADA EARLY TUESDAY
NIGHT...TO WESTERN UPPER MI BY WED EVENING. THE BUILDING HIGH WILL
PROVIDE QUIET WX FOR MOST OF NORTHERN MI. HOWEVER...WE MAY SEE SOME
PRECIP CHANCES EMERGE UP NEAR SUPERIOR. A DIGGING SHORTWAVE REACHES
SUPERIOR WED MORNING. LOW LEVEL COLD ADVECTION CONTINUES...WITH
850MB TEMPS LOWERING NEAR 0C. A SURFACE TROF AXIS WILL AID
CONVERGENCE AND MOISTURE POOLING BELOW THE 725MB INVERSION. WILL ADD
A CHANCE OF SHRA TO PARTS OF CHIPPEWA CO LATE TUE NIGHT AND
ESPECIALLY WED MORNING. ELSEWHERE...MOSTLY CLEAR TO PARTLY CLOUDY
SKIES WILL WAY TO A HEALTHY CU FIELD BY EARLY AFTERNOON WED. MIN
TEMPS UPPER 30S TO LOWER 40S. MAX TEMPS MIDDLE 50S TO LOWER 60S.
REST OF THE FORECAST...EXTENDED MODELS AGREE THAT THE HIGH PRESSURE
IN PLACE BY WED NIGHT WILL BE DIFFICULT TO DISLODGE. IN FACT...IT
LOOKS TO BE REINFORCED OUT TOWARD FRIDAY. A DYING COLD FRONT MAY TRY
TO MOVE IN THURSDAY NIGHT AHEAD OF THE NEXT HIGH...BUT IT HAS NO
MOISTURE TO WORK WITH...AND ANY SORT OF DYNAMICS ARE UP TOWARD JAMES
BAY. THE EXTENDED WILL BE DEVOID OF ANY PRECIP. BELOW-NORMAL TEMPS
ON THURSDAY WILL MODERATE CLOSER TO NORMAL FOR THE WEEKEND.
WEDNESDAY NIGHT STILL LOOKS TO HAVE CONSIDERABLE FROST POTENTIAL IN
THE USUAL INLAND LOCALES...THE FORECAST WILL CONTINUE TO REFLECT
THIS. THURSDAY NIGHT COULD ALSO HAVE SOME FROST CONCERNS...THOUGH
LIKELY NOT AS MANY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 658 AM EDT MON SEP 24 2012
VFR. GUSTY SW WINDS TODAY.
THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN TODAY...BETWEEN
HIGH PRESSURE IN THE OHIO VALLEY...AND A COLD FRONT DROPPING
SOUTH FROM FAR NORTHERN ONTARIO. SW WINDS WILL RAMP UP QUICKLY
THIS MORNING...AND WILL BE QUITE GUSTY THIS AFTERNOON...ESPECIALLY
AT PLN. PLENTY OF CIRRUS OVERHEAD TODAY. AS THE FRONT TO THE NORTH
APPROACHES...A FEW -SHRA MAY GET KICKED OFF NEAR PLN/APN THIS
EVENING. WINDS DIMINISH TONIGHT...AND VEER NORTHERLY AT PLN/TVC AS
THE FRONT ARRIVES VERY LATE.
&&
.MARINE...
ISSUED AT 251 AM EDT MON SEP 24 2012
PRESSURE GRADIENT TIGHTENS THROUGH THE DAY AHEAD OF A COLD
FRONT THAT WILL SLIP THROUGH THE AREA TONIGHT. WITH REMAINING OVER
WATER INSTABILITY...VERY GUSTY WINDS WILL DEVELOP THIS MORNING AND
THROUGH THE AFTERNOON. GALE FORCE GUSTS ARE CERTAIN ON THE LAKE
MICHIGAN NEARSHORE AREAS AND THROUGH THE STRAITS. LESS CERTAINTY FOR
REACHING GALE FORCE ON THE LAKE HURON SIDE AS WELL AS WHITEFISH
BAY/SAINT MARYS RIVER. BUT GUSTINESS OVER LAND WILL LIKELY EXTEND
OUT INTO THE WATER...AND WILL THUS CONTINUE INHERITED GALE WARNINGS
FOR ALL NEARSHORE ZONES INTO TONIGHT. CONDITIONS WILL IMPROVE
THROUGH THE OVERNIGHT...WITH GALES LIKELY ENDING ALL AREAS WELL
BEFORE SUNRISE.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ015-016-019-020.
LH...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LHZ345>349.
LM...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LMZ323-341-342-344>346.
LS...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...JZ
MARINE...BA/MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
831 AM EDT MON SEP 24 2012
.SYNOPSIS...
ISSUED AT 251 AM EDT MON SEP 24 2012
A SIGNIFICANT CHANGE IN THE WEATHER IS UNDERWAY. INCREASING WINDS
BETWEEN HIGH PRESSURE IN THE OHIO VALLEY AND A COLD FRONT IN FAR
NORTHERN ONTARIO WILL USHER THE COLD AIR OUT OF NORTHERN MICHIGAN
TODAY. SOUTHWEST WINDS WILL BECOME QUITE GUSTY BY AFTERNOON. THE
FRONT WILL CROSS NORTHERN MICHIGAN TONIGHT AND TUESDAY...WITH ONLY A
SMALL CHANCE FOR A FEW SHOWERS. A LARGE AREA OF HIGH PRESSURE WILL
MOVE INTO THE REGION LATE THIS WEEK AND INTO THE WEEKEND...PROVIDING
QUITE WEATHER.
&&
.UPDATE...
ISSUED AT 830 AM EDT MON SEP 24 2012
QUICK UPDATE TO DROP THE AX ON THE CURRENT FROST ADVISORY. MOST
SPOTS ARE WELL ABOVE FREEZING AS OF 815 AM...AND WILL ONLY
CONTINUE TO CLIMB AT MIXING DEEPENS THE NEXT FEW HOURS. HAVE ALSO
RAISED CLOUD COVER SIGNIFICANTLY FROM ABOUT M-72 ON NORTH THROUGH
THE DAY. CURRENT SATELLITE IMAGERY (THOUGH HINDERED BY GOES-13
OUTAGE) ALONG WITH SHORT TERM GUIDANCE TRENDS SUPPORT A ROUND OF
QUITE THICK WARM ADVECTION-DRIVEN CIRRUS PUSHING THROUGH THE AREA
INTO EARLY AFTERNOON...ONLY TO BE FOLLOWED BY A NICE PUSH OF MID
LEVEL RH OUT AHEAD OF AN AMPLIFYING UPPER WAVE DROPPING INTO LAKE
SUPERIOR. DON`T THINK THE ADDED CLOUD COVER WILL HAVE TOO MUCH
EFFECT ON HIGH TEMPS GIVEN EXPECTED DEEP TURBULENT MIXING INTO A
STEADILY WARMING AIRMASS ALOFT...BUT MAY ULTIMATELY NEED TO CHOP
OFF A DEGREE OR TWO WITH FUTURE UPDATES. GOING GALE/WIND ADVISORY
HEADLINES LOOK JUST FINE. CERTAINLY A QUITE WINDY DAY IN ALL
AREAS.
UPDATE ISSUED AT 658 AM EDT MON SEP 24 2012
CIRRUS IS EXPANDING FROM THE NW...AND IS CURRENTLY QUITE THICK
ALONG/NORTH OF M-68. CLOUD COVER HAS BEEN ADJUSTED ACCORDINGLY.
WARMER AIR IS POISED TO SWOOP IN FROM LAKE MI AS WINDS RECOUPLE
(MANISTEE HARBOR C-MAN SITE IS 55F PRESENTLY...WHILE A FEW MILES
INLAND MBL AIRPORT IS 32).
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 251 AM EDT MON SEP 24 2012
DEFINITE SIGNS OF CHANGE ACROSS THE NORTH WOODS EARLY THIS
MORNING...WITH CORE OF COLD ANOMALIES AND CENTER OF TROUGH AXIS THAT
HAS PLAGUED THE REGION FOR THE LAST SEVERAL DAYS NOW ROTATING OFF TO
OUR NORTHEAST. NO DOUBT TROUGHING STILL DOMINATES...BUT OFF THE DECK
WAA ALREADY BEGINNING TO REAR ITS HEAD ON NORTH SIDE OF SURFACE HIGH
PRESSURE ROTATING THROUGH THE OHIO VALLEY. DECREASING OVER-WATER
INSTABILITY VIA SLIGHT WARMING H85 TEMPERATURES (UP TO NEAR 0C PER
LATEST HIGH RES RAP GUIDANCE) AND ONSLAUGHT OF DEEP LAYER DRYING
(H85 NEGATIVE UPPER SINGLE DIGIT DEWPOINTS OVER NORTHERN LAKE
MICHIGAN) HAS NOT ONLY ESSENTIALLY SHUT OFF THE LAKE INDUCED SHOWER
MACHINE...BUT PUT A SERIOUS DENT IN EVEN LAKE CLOUD FORMATION.
THUS...SKIES HAVE CONTINUED TO CLEAR ACROSS MUCH OF OUR AREA...
ALTHOUGH HIGH CLOUDS HAVE BEGUN TO FILTER INTO UPPER MICHIGAN ON
FRONT END OF STRONG UPPER LEVEL JET STREAK AND ATTENDANT MID LEVEL
WAVE ROTATING SOUTH OUT OF WESTERN ONTARIO. COMBO OF CLEARING SKIES
AND QUICK LOSS OF WINDS THIS EVENING HAS ALLOWED TEMPERATURES TO
TANK...WITH READINGS ALREADY DIPPING WELL INTO THE 30S ACROSS
INTERIOR REGIONS SOUTH OF THE MIGHTY MAC. LIGHT WINDS WILL BE A
SHORT EVENT...WITH ALREADY SIGNS OF INCREASING WINDS OFF THE SURFACE
PER LATEST GUIDANCE. THIS IS JUST A BEGINNING OF THINGS TO COME...
WITH STRONG PRESSURE GRADIENT AND APPROACHING UPPER JET CORE ONLY
ENHANCING DOWN LOW WIND RESPONSE...FIRST OVER THE BIG WATERS BY
MORNING...AND ACROSS ALL AREAS AFTER SUNRISE. PRIMARY FORECAST
CONCERNS CENTER ON WIND SPEEDS AND ASSOCIATED POTENTIAL
HEADLINES...WITH LOW END SHOWER THREAT FROM APPROACHING EARLIER
MENTIONED WAVE A SECONDARY CONCERN.
FIRST THINGS FIRST...AND WILL LET FROST ADVISORY RUN ITS COURSE
THROUGH THE EARLY MORNING...WITH CURRENT TEMPERATURE TRENDS
SUPPORTING LOWS BY SUNRISE DIPPING INTO THE LOWER 30S IN THE
TRADITIONAL ICE BOX LOCATIONS. OTHERWISE...BIGGEST STORY TODAY WILL
BE THE WINDS...WHICH RAMP-UP QUICKLY THIS MORNING AS LOW LEVEL JET
INTENSIFIES OVERHEAD...WITH 950MB WINDS PUSHING 30 TO 40 KNOTS BY
18Z...WITH SPEEDS PUSHING 45 KNOTS UP THROUGH NORTHERN LAKE MICHIGAN
AND THE STRAITS. DESPITE WAA REGIME...GUIDANCE REMAINS STEADFAST OF
GOOD MIXING WELL PAST THIS LAYER...UP TO 850MBS...ESPECIALLY OVER
THE BIG WATERS WHERE CONDITIONS WILL REMAIN SOMEWHAT UNSTABLE.
BUFKIT MOMENTUM TRANSFER PROGS SUGGEST A GOOD PORTION OF ELEVATED
WINDS WILL MIX DOWN...SUPPORTING WIDESPREAD WIND GUSTS BY EARLY
AFTERNOON PUSHING 30 TO 35 MPH OVER MOST INTERIOR REGIONS. BIGGEST
CONCERN REMAINS UP ALONG THE NORTHWEST LOWER COASTLINE AND IN THE
STRAITS REGION WHERE CORE OF JET AND INSTABILITY IS MAXIMIZED OVER
OPEN WATER. COULD EASILY SEE 45 MPH GUSTS ALONG THE IMMEDIATE COASTS
FROM LEELANAU COUNTY UP INTO MACKINAC COUNTY...INCLUDING BEAVER
ISLAND. WILL GO AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY FOR
THESE AREAS FROM LATE MORNING RIGHT THROUGH THE AFTERNOON HOURS.
SHOULD BE BELOW ADVISORY LEVELS ELSEWHERE...ALTHOUGH DO HAVE SOME
CONCERN FOR NORTHWEST BENZIE COUNTY AS WELL AS THE IMMEDIATE
SHORELINE OF IOSCO COUNTY OVER NORTHEAST LOWER AS WINDS FUNNEL UP
SAGINAW BAY. WILL HOLD OFF FOR THESE AREAS...BUT DEFINITELY PASS
THIS CONCERN ON TO THE INCOMING CREW.
OTHER STORY TODAY WILL BE LATE DAY RAIN CHANCES ACROSS EASTERN UPPER
AND THE TIP OF THE MITT AS ONTARIO WAVE AND ATTENDANT COLD FRONT
DROP INTO THE AREA. DYNAMICS NOT TOO SHABBY...WITH GOOD CORE OF MID
LEVEL -DIVQ OVERTOPPING DECENT BAND OF LOW LEVEL CONVERGENCE. LACK
OF MOISTURE REMAINS A BIG DETERRENT TO RAIN POTENTIAL...WITH
PRE-FRONTAL MOISTURE ADVECTION ANEMIC AT BEST...AS H85 DEWPOINTS
ONLY APPROACH 1C. GIVEN ABOVE...WILL MAKE LITTLE CHANGE TO INHERITED
LATE DAY LOW END POPS ACROSS THE FAR NORTH. GUSTY SOUTHWEST WINDS
WORK THEIR MAGIC...TACKING ON A GOOD 10 TO 15 DEGREES TO HIGH
TEMPERATURES EXPERIENCED THE LAST COUPLE DAYS. LOOK FOR AFTERNOON
READINGS ACTUALLY PUSHING LEVELS MUCH CLOSER TO NORMAL...WITH HIGHS
WELL INTO THE 60S!
FRONT SLOWLY SAGS SOUTH THROUGH THE OVERNIGHT AS MID LEVEL SUPPORT
BEGINS TO SHEAR OUT. MOISTURE PROFILES CHANGE LITTLE...WITH JUST A
NARROW AND RELATIVELY LIMITED SLUG OF MOISTURE ACCOMPANYING THE
FRONT. CAN`T ENTIRELY RULE OUT A LIGHT SHOWER...BUT FEEL MOST AREAS
AND MOST OF THE TIME WILL REMAIN DRY. WINDS DECREASE SUBSTANTIALLY
THROUGH THE EVENING AS MIXING IS LOST AND LOW LEVEL JET PIVOTS OFF
TO THE EAST. A MILD OVERNIGHT COMPARED TO RECENT TIMES...WITH LOWS
ONLY DROPPING INTO THE 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 251 AM EDT MON SEP 24 2012
A RELATIVELY UNEVENTFUL WORK WEEK IS AHEAD...AS THE UPPER FLOW OVER
THE CONUS AND SOUTHERN CANADA DEAMPLIFIES SOMEWHAT. THE UPPER LOW
OVER NORTHERN QUEBEC WILL EJECT NE-WARD TOWARD MID-WEEK...THOUGH IT
WILL DRAG ONE LAST UPPER TROF ACROSS THE LAKES REGION ON WEDNESDAY.
BUT BY THEN...A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED OVER
THE WESTERN LAKES. THE COLD FRONT TALKED ABOUT IN THE SHORT-TERM
SECTION ABOVE...WILL SLOWLY MOVE SOUTH OF NORTHERN MI TUESDAY AND
TUE NIGHT.
TUESDAY...COLD FRONT WILL START THE MORNING ALONG ROUGHLY AN LDM-APN
LINE...WITH A WEAK SURFACE WAVE NEAR LDM. THE WAVE...AND THUS THE
FRONT...WILL GET HELD UP AS THEY BOTH FEEL A PROMINENT SHORTWAVE
DIGGING TOWARD NORTHERN SUPERIOR BY THE END OF THE DAY. AT THAT
TIME...THE FRONT WILL BE JUST OUT OF SE SECTIONS OF THE FORECAST
AREA....WITH THE SURFACE WAVE OVER SAGINAW BAY. BEHIND THE FRONT...A
SURFACE RIDGE AXIS WILL POKE EASTWARD ACROSS UPPER MI AND SOUTHERN
SUPERIOR.
THE SURFACE WAVE...AND LOCALLY BACKED FLOW OFF OF LAKE HURON...WILL
PRODUCE A PROMINENT AREA OF 1000-850MB CONVERGENCE...ALONG AND SE OF
AN APN-HTL LINE. HOWEVER...EVEN IF SURFACE DEW POINTS GET BOOSTED TO
50F IN THIS AREA PER NAM SOUNDINGS (AND FOR NOW EVEN THAT LOOKS
OPTIMISTIC)...UPDRAFTS WILL BE CAPPED OFF AT 625MB/-5C. NO ICE
EXPECTED IN THESE CLOUDS...AND NOT SURE THAT PRECIP GENERATED VIA
WARM RAIN PROCESSES WILL GET THRU THE RELATIVELY DRY AIR BELOW CLOUD
BASE/825MB. MUCAPE ONLY TOPS OUT AT 100J/KG. WILL MODIFY PRECIP
WORDING SLIGHTLY...GOING WITH A SMALL CHANCE FOR SPRINKLES (INSTEAD
OF OUTRIGHT SHOWERS) IN THE AFTERNOON IN PARTS OF NE LOWER.
ELSEWHERE...SCT DIURNAL CU AND/OR LAKE STRATOCU WILL BE PRESENT
(POST-FRONTAL DELTA T/S NEAR 15C OFF OF SUPERIOR AND FAR NORTHERN
LOWER LAKE MI). MAX TEMPS WILL RANGE FROM UPPER 50S IN EASTERN UPPER
MI...TO THE LOWER 70S IN THE FAR SE.
TUE NIGHT/WEDNESDAY...COLD FRONT MOVES TO FAR SOUTHERN LOWER MI BY
WED MORNING. HIGH PRESSURE MOVES FROM CENTRAL CANADA EARLY TUESDAY
NIGHT...TO WESTERN UPPER MI BY WED EVENING. THE BUILDING HIGH WILL
PROVIDE QUIET WX FOR MOST OF NORTHERN MI. HOWEVER...WE MAY SEE SOME
PRECIP CHANCES EMERGE UP NEAR SUPERIOR. A DIGGING SHORTWAVE REACHES
SUPERIOR WED MORNING. LOW LEVEL COLD ADVECTION CONTINUES...WITH
850MB TEMPS LOWERING NEAR 0C. A SURFACE TROF AXIS WILL AID
CONVERGENCE AND MOISTURE POOLING BELOW THE 725MB INVERSION. WILL ADD
A CHANCE OF SHRA TO PARTS OF CHIPPEWA CO LATE TUE NIGHT AND
ESPECIALLY WED MORNING. ELSEWHERE...MOSTLY CLEAR TO PARTLY CLOUDY
SKIES WILL WAY TO A HEALTHY CU FIELD BY EARLY AFTERNOON WED. MIN
TEMPS UPPER 30S TO LOWER 40S. MAX TEMPS MIDDLE 50S TO LOWER 60S.
REST OF THE FORECAST...EXTENDED MODELS AGREE THAT THE HIGH PRESSURE
IN PLACE BY WED NIGHT WILL BE DIFFICULT TO DISLODGE. IN FACT...IT
LOOKS TO BE REINFORCED OUT TOWARD FRIDAY. A DYING COLD FRONT MAY TRY
TO MOVE IN THURSDAY NIGHT AHEAD OF THE NEXT HIGH...BUT IT HAS NO
MOISTURE TO WORK WITH...AND ANY SORT OF DYNAMICS ARE UP TOWARD JAMES
BAY. THE EXTENDED WILL BE DEVOID OF ANY PRECIP. BELOW-NORMAL TEMPS
ON THURSDAY WILL MODERATE CLOSER TO NORMAL FOR THE WEEKEND.
WEDNESDAY NIGHT STILL LOOKS TO HAVE CONSIDERABLE FROST POTENTIAL IN
THE USUAL INLAND LOCALES...THE FORECAST WILL CONTINUE TO REFLECT
THIS. THURSDAY NIGHT COULD ALSO HAVE SOME FROST CONCERNS...THOUGH
LIKELY NOT AS MANY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 658 AM EDT MON SEP 24 2012
VFR. GUSTY SW WINDS TODAY.
THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN TODAY...BETWEEN
HIGH PRESSURE IN THE OHIO VALLEY...AND A COLD FRONT DROPPING
SOUTH FROM FAR NORTHERN ONTARIO. SW WINDS WILL RAMP UP QUICKLY
THIS MORNING...AND WILL BE QUITE GUSTY THIS AFTERNOON...ESPECIALLY
AT PLN. PLENTY OF CIRRUS OVERHEAD TODAY. AS THE FRONT TO THE NORTH
APPROACHES...A FEW -SHRA MAY GET KICKED OFF NEAR PLN/APN THIS
EVENING. WINDS DIMINISH TONIGHT...AND VEER NORTHERLY AT PLN/TVC AS
THE FRONT ARRIVES VERY LATE.
&&
.MARINE...
ISSUED AT 251 AM EDT MON SEP 24 2012
PRESSURE GRADIENT TIGHTENS THROUGH THE DAY AHEAD OF A COLD
FRONT THAT WILL SLIP THROUGH THE AREA TONIGHT. WITH REMAINING OVER
WATER INSTABILITY...VERY GUSTY WINDS WILL DEVELOP THIS MORNING AND
THROUGH THE AFTERNOON. GALE FORCE GUSTS ARE CERTAIN ON THE LAKE
MICHIGAN NEARSHORE AREAS AND THROUGH THE STRAITS. LESS CERTAINTY FOR
REACHING GALE FORCE ON THE LAKE HURON SIDE AS WELL AS WHITEFISH
BAY/SAINT MARYS RIVER. BUT GUSTINESS OVER LAND WILL LIKELY EXTEND
OUT INTO THE WATER...AND WILL THUS CONTINUE INHERITED GALE WARNINGS
FOR ALL NEARSHORE ZONES INTO TONIGHT. CONDITIONS WILL IMPROVE
THROUGH THE OVERNIGHT...WITH GALES LIKELY ENDING ALL AREAS WELL
BEFORE SUNRISE.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MIZ015-016-019-020.
LH...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LHZ345>349.
LM...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LMZ323-341-342-344>346.
LS...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...LAWRENCE
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...JZ
MARINE...BA/MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
658 AM EDT MON SEP 24 2012
.SYNOPSIS...
ISSUED AT 251 AM EDT MON SEP 24 2012
A SIGNIFICANT CHANGE IN THE WEATHER IS UNDERWAY. INCREASING WINDS
BETWEEN HIGH PRESSURE IN THE OHIO VALLEY AND A COLD FRONT IN FAR
NORTHERN ONTARIO WILL USHER THE COLD AIR OUT OF NORTHERN MICHIGAN
TODAY. SOUTHWEST WINDS WILL BECOME QUITE GUSTY BY AFTERNOON. THE
FRONT WILL CROSS NORTHERN MICHIGAN TONIGHT AND TUESDAY...WITH ONLY A
SMALL CHANCE FOR A FEW SHOWERS. A LARGE AREA OF HIGH PRESSURE WILL
MOVE INTO THE REGION LATE THIS WEEK AND INTO THE WEEKEND...PROVIDING
QUITE WEATHER.
&&
.UPDATE...
ISSUED AT 658 AM EDT MON SEP 24 2012
CIRRUS IS EXPANDING FROM THE NW...AND IS CURRENTLY QUITE THICK
ALONG/NORTH OF M-68. CLOUD COVER HAS BEEN ADJUSTED ACCORDINGLY.
WARMER AIR IS POISED TO SWOOP IN FROM LAKE MI AS WINDS RECOUPLE
(MANISTEE HARBOR C-MAN SITE IS 55F PRESENTLY...WHILE A FEW MILES
INLAND MBL AIRPORT IS 32).
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 251 AM EDT MON SEP 24 2012
DEFINITE SIGNS OF CHANGE ACROSS THE NORTH WOODS EARLY THIS
MORNING...WITH CORE OF COLD ANOMALIES AND CENTER OF TROUGH AXIS THAT
HAS PLAGUED THE REGION FOR THE LAST SEVERAL DAYS NOW ROTATING OFF TO
OUR NORTHEAST. NO DOUBT TROUGHING STILL DOMINATES...BUT OFF THE DECK
WAA ALREADY BEGINNING TO REAR ITS HEAD ON NORTH SIDE OF SURFACE HIGH
PRESSURE ROTATING THROUGH THE OHIO VALLEY. DECREASING OVER-WATER
INSTABILITY VIA SLIGHT WARMING H85 TEMPERATURES (UP TO NEAR 0C PER
LATEST HIGH RES RAP GUIDANCE) AND ONSLAUGHT OF DEEP LAYER DRYING
(H85 NEGATIVE UPPER SINGLE DIGIT DEWPOINTS OVER NORTHERN LAKE
MICHIGAN) HAS NOT ONLY ESSENTIALLY SHUT OFF THE LAKE INDUCED SHOWER
MACHINE...BUT PUT A SERIOUS DENT IN EVEN LAKE CLOUD FORMATION.
THUS...SKIES HAVE CONTINUED TO CLEAR ACROSS MUCH OF OUR AREA...
ALTHOUGH HIGH CLOUDS HAVE BEGUN TO FILTER INTO UPPER MICHIGAN ON
FRONT END OF STRONG UPPER LEVEL JET STREAK AND ATTENDANT MID LEVEL
WAVE ROTATING SOUTH OUT OF WESTERN ONTARIO. COMBO OF CLEARING SKIES
AND QUICK LOSS OF WINDS THIS EVENING HAS ALLOWED TEMPERATURES TO
TANK...WITH READINGS ALREADY DIPPING WELL INTO THE 30S ACROSS
INTERIOR REGIONS SOUTH OF THE MIGHTY MAC. LIGHT WINDS WILL BE A
SHORT EVENT...WITH ALREADY SIGNS OF INCREASING WINDS OFF THE SURFACE
PER LATEST GUIDANCE. THIS IS JUST A BEGINNING OF THINGS TO COME...
WITH STRONG PRESSURE GRADIENT AND APPROACHING UPPER JET CORE ONLY
ENHANCING DOWN LOW WIND RESPONSE...FIRST OVER THE BIG WATERS BY
MORNING...AND ACROSS ALL AREAS AFTER SUNRISE. PRIMARY FORECAST
CONCERNS CENTER ON WIND SPEEDS AND ASSOCIATED POTENTIAL
HEADLINES...WITH LOW END SHOWER THREAT FROM APPROACHING EARLIER
MENTIONED WAVE A SECONDARY CONCERN.
FIRST THINGS FIRST...AND WILL LET FROST ADVISORY RUN ITS COURSE
THROUGH THE EARLY MORNING...WITH CURRENT TEMPERATURE TRENDS
SUPPORTING LOWS BY SUNRISE DIPPING INTO THE LOWER 30S IN THE
TRADITIONAL ICE BOX LOCATIONS. OTHERWISE...BIGGEST STORY TODAY WILL
BE THE WINDS...WHICH RAMP-UP QUICKLY THIS MORNING AS LOW LEVEL JET
INTENSIFIES OVERHEAD...WITH 950MB WINDS PUSHING 30 TO 40 KNOTS BY
18Z...WITH SPEEDS PUSHING 45 KNOTS UP THROUGH NORTHERN LAKE MICHIGAN
AND THE STRAITS. DESPITE WAA REGIME...GUIDANCE REMAINS STEADFAST OF
GOOD MIXING WELL PAST THIS LAYER...UP TO 850MBS...ESPECIALLY OVER
THE BIG WATERS WHERE CONDITIONS WILL REMAIN SOMEWHAT UNSTABLE.
BUFKIT MOMENTUM TRANSFER PROGS SUGGEST A GOOD PORTION OF ELEVATED
WINDS WILL MIX DOWN...SUPPORTING WIDESPREAD WIND GUSTS BY EARLY
AFTERNOON PUSHING 30 TO 35 MPH OVER MOST INTERIOR REGIONS. BIGGEST
CONCERN REMAINS UP ALONG THE NORTHWEST LOWER COASTLINE AND IN THE
STRAITS REGION WHERE CORE OF JET AND INSTABILITY IS MAXIMIZED OVER
OPEN WATER. COULD EASILY SEE 45 MPH GUSTS ALONG THE IMMEDIATE COASTS
FROM LEELANAU COUNTY UP INTO MACKINAC COUNTY...INCLUDING BEAVER
ISLAND. WILL GO AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY FOR
THESE AREAS FROM LATE MORNING RIGHT THROUGH THE AFTERNOON HOURS.
SHOULD BE BELOW ADVISORY LEVELS ELSEWHERE...ALTHOUGH DO HAVE SOME
CONCERN FOR NORTHWEST BENZIE COUNTY AS WELL AS THE IMMEDIATE
SHORELINE OF IOSCO COUNTY OVER NORTHEAST LOWER AS WINDS FUNNEL UP
SAGINAW BAY. WILL HOLD OFF FOR THESE AREAS...BUT DEFINITELY PASS
THIS CONCERN ON TO THE INCOMING CREW.
OTHER STORY TODAY WILL BE LATE DAY RAIN CHANCES ACROSS EASTERN UPPER
AND THE TIP OF THE MITT AS ONTARIO WAVE AND ATTENDANT COLD FRONT
DROP INTO THE AREA. DYNAMICS NOT TOO SHABBY...WITH GOOD CORE OF MID
LEVEL -DIVQ OVERTOPPING DECENT BAND OF LOW LEVEL CONVERGENCE. LACK
OF MOISTURE REMAINS A BIG DETERRENT TO RAIN POTENTIAL...WITH
PRE-FRONTAL MOISTURE ADVECTION ANEMIC AT BEST...AS H85 DEWPOINTS
ONLY APPROACH 1C. GIVEN ABOVE...WILL MAKE LITTLE CHANGE TO INHERITED
LATE DAY LOW END POPS ACROSS THE FAR NORTH. GUSTY SOUTHWEST WINDS
WORK THEIR MAGIC...TACKING ON A GOOD 10 TO 15 DEGREES TO HIGH
TEMPERATURES EXPERIENCED THE LAST COUPLE DAYS. LOOK FOR AFTERNOON
READINGS ACTUALLY PUSHING LEVELS MUCH CLOSER TO NORMAL...WITH HIGHS
WELL INTO THE 60S!
FRONT SLOWLY SAGS SOUTH THROUGH THE OVERNIGHT AS MID LEVEL SUPPORT
BEGINS TO SHEAR OUT. MOISTURE PROFILES CHANGE LITTLE...WITH JUST A
NARROW AND RELATIVELY LIMITED SLUG OF MOISTURE ACCOMPANYING THE
FRONT. CAN`T ENTIRELY RULE OUT A LIGHT SHOWER...BUT FEEL MOST AREAS
AND MOST OF THE TIME WILL REMAIN DRY. WINDS DECREASE SUBSTANTIALLY
THROUGH THE EVENING AS MIXING IS LOST AND LOW LEVEL JET PIVOTS OFF
TO THE EAST. A MILD OVERNIGHT COMPARED TO RECENT TIMES...WITH LOWS
ONLY DROPPING INTO THE 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 251 AM EDT MON SEP 24 2012
A RELATIVELY UNEVENTFUL WORK WEEK IS AHEAD...AS THE UPPER FLOW OVER
THE CONUS AND SOUTHERN CANADA DEAMPLIFIES SOMEWHAT. THE UPPER LOW
OVER NORTHERN QUEBEC WILL EJECT NE-WARD TOWARD MID-WEEK...THOUGH IT
WILL DRAG ONE LAST UPPER TROF ACROSS THE LAKES REGION ON WEDNESDAY.
BUT BY THEN...A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED OVER
THE WESTERN LAKES. THE COLD FRONT TALKED ABOUT IN THE SHORT-TERM
SECTION ABOVE...WILL SLOWLY MOVE SOUTH OF NORTHERN MI TUESDAY AND
TUE NIGHT.
TUESDAY...COLD FRONT WILL START THE MORNING ALONG ROUGHLY AN LDM-APN
LINE...WITH A WEAK SURFACE WAVE NEAR LDM. THE WAVE...AND THUS THE
FRONT...WILL GET HELD UP AS THEY BOTH FEEL A PROMINENT SHORTWAVE
DIGGING TOWARD NORTHERN SUPERIOR BY THE END OF THE DAY. AT THAT
TIME...THE FRONT WILL BE JUST OUT OF SE SECTIONS OF THE FORECAST
AREA....WITH THE SURFACE WAVE OVER SAGINAW BAY. BEHIND THE FRONT...A
SURFACE RIDGE AXIS WILL POKE EASTWARD ACROSS UPPER MI AND SOUTHERN
SUPERIOR.
THE SURFACE WAVE...AND LOCALLY BACKED FLOW OFF OF LAKE HURON...WILL
PRODUCE A PROMINENT AREA OF 1000-850MB CONVERGENCE...ALONG AND SE OF
AN APN-HTL LINE. HOWEVER...EVEN IF SURFACE DEW POINTS GET BOOSTED TO
50F IN THIS AREA PER NAM SOUNDINGS (AND FOR NOW EVEN THAT LOOKS
OPTIMISTIC)...UPDRAFTS WILL BE CAPPED OFF AT 625MB/-5C. NO ICE
EXPECTED IN THESE CLOUDS...AND NOT SURE THAT PRECIP GENERATED VIA
WARM RAIN PROCESSES WILL GET THRU THE RELATIVELY DRY AIR BELOW CLOUD
BASE/825MB. MUCAPE ONLY TOPS OUT AT 100J/KG. WILL MODIFY PRECIP
WORDING SLIGHTLY...GOING WITH A SMALL CHANCE FOR SPRINKLES (INSTEAD
OF OUTRIGHT SHOWERS) IN THE AFTERNOON IN PARTS OF NE LOWER.
ELSEWHERE...SCT DIURNAL CU AND/OR LAKE STRATOCU WILL BE PRESENT
(POST-FRONTAL DELTA T/S NEAR 15C OFF OF SUPERIOR AND FAR NORTHERN
LOWER LAKE MI). MAX TEMPS WILL RANGE FROM UPPER 50S IN EASTERN UPPER
MI...TO THE LOWER 70S IN THE FAR SE.
TUE NIGHT/WEDNESDAY...COLD FRONT MOVES TO FAR SOUTHERN LOWER MI BY
WED MORNING. HIGH PRESSURE MOVES FROM CENTRAL CANADA EARLY TUESDAY
NIGHT...TO WESTERN UPPER MI BY WED EVENING. THE BUILDING HIGH WILL
PROVIDE QUIET WX FOR MOST OF NORTHERN MI. HOWEVER...WE MAY SEE SOME
PRECIP CHANCES EMERGE UP NEAR SUPERIOR. A DIGGING SHORTWAVE REACHES
SUPERIOR WED MORNING. LOW LEVEL COLD ADVECTION CONTINUES...WITH
850MB TEMPS LOWERING NEAR 0C. A SURFACE TROF AXIS WILL AID
CONVERGENCE AND MOISTURE POOLING BELOW THE 725MB INVERSION. WILL ADD
A CHANCE OF SHRA TO PARTS OF CHIPPEWA CO LATE TUE NIGHT AND
ESPECIALLY WED MORNING. ELSEWHERE...MOSTLY CLEAR TO PARTLY CLOUDY
SKIES WILL WAY TO A HEALTHY CU FIELD BY EARLY AFTERNOON WED. MIN
TEMPS UPPER 30S TO LOWER 40S. MAX TEMPS MIDDLE 50S TO LOWER 60S.
REST OF THE FORECAST...EXTENDED MODELS AGREE THAT THE HIGH PRESSURE
IN PLACE BY WED NIGHT WILL BE DIFFICULT TO DISLODGE. IN FACT...IT
LOOKS TO BE REINFORCED OUT TOWARD FRIDAY. A DYING COLD FRONT MAY TRY
TO MOVE IN THURSDAY NIGHT AHEAD OF THE NEXT HIGH...BUT IT HAS NO
MOISTURE TO WORK WITH...AND ANY SORT OF DYNAMICS ARE UP TOWARD JAMES
BAY. THE EXTENDED WILL BE DEVOID OF ANY PRECIP. BELOW-NORMAL TEMPS
ON THURSDAY WILL MODERATE CLOSER TO NORMAL FOR THE WEEKEND.
WEDNESDAY NIGHT STILL LOOKS TO HAVE CONSIDERABLE FROST POTENTIAL IN
THE USUAL INLAND LOCALES...THE FORECAST WILL CONTINUE TO REFLECT
THIS. THURSDAY NIGHT COULD ALSO HAVE SOME FROST CONCERNS...THOUGH
LIKELY NOT AS MANY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 658 AM EDT MON SEP 24 2012
VFR. GUSTY SW WINDS TODAY.
THE PRESSURE GRADIENT WILL CONTINUE TO TIGHTEN TODAY...BETWEEN
HIGH PRESSURE IN THE OHIO VALLEY...AND A COLD FRONT DROPPING
SOUTH FROM FAR NORTHERN ONTARIO. SW WINDS WILL RAMP UP QUICKLY
THIS MORNING...AND WILL BE QUITE GUSTY THIS AFTERNOON...ESPECIALLY
AT PLN. PLENTY OF CIRRUS OVERHEAD TODAY. AS THE FRONT TO THE NORTH
APPROACHES...A FEW -SHRA MAY GET KICKED OFF NEAR PLN/APN THIS
EVENING. WINDS DIMINISH TONIGHT...AND VEER NORTHERLY AT PLN/TVC AS
THE FRONT ARRIVES VERY LATE.
&&
.MARINE...
ISSUED AT 251 AM EDT MON SEP 24 2012
PRESSURE GRADIENT TIGHTENS THROUGH THE DAY AHEAD OF A COLD
FRONT THAT WILL SLIP THROUGH THE AREA TONIGHT. WITH REMAINING OVER
WATER INSTABILITY...VERY GUSTY WINDS WILL DEVELOP THIS MORNING AND
THROUGH THE AFTERNOON. GALE FORCE GUSTS ARE CERTAIN ON THE LAKE
MICHIGAN NEARSHORE AREAS AND THROUGH THE STRAITS. LESS CERTAINTY FOR
REACHING GALE FORCE ON THE LAKE HURON SIDE AS WELL AS WHITEFISH
BAY/SAINT MARYS RIVER. BUT GUSTINESS OVER LAND WILL LIKELY EXTEND
OUT INTO THE WATER...AND WILL THUS CONTINUE INHERITED GALE WARNINGS
FOR ALL NEARSHORE ZONES INTO TONIGHT. CONDITIONS WILL IMPROVE
THROUGH THE OVERNIGHT...WITH GALES LIKELY ENDING ALL AREAS WELL
BEFORE SUNRISE.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR MIZ017-018-
022>024-026>036-041-042.
WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR MIZ015-016-019-020.
LH...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LHZ345>349.
LM...GALE WARNING UNTIL 5 AM EDT TUESDAY FOR LMZ323-341-342-344>346.
LS...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...JZ
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...JZ
MARINE...BA/MB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
255 AM EDT MON SEP 24 2012
.SYNOPSIS...
ISSUED AT 251 AM EDT MON SEP 24 2012
A SIGNIFICANT CHANGE IN THE WEATHER IS UNDERWAY. INCREASING WINDS
BETWEEN HIGH PRESSURE IN THE OHIO VALLEY AND A COLD FRONT IN FAR
NORTHERN ONTARIO WILL USHER THE COLD AIR OUT OF NORTHERN MICHIGAN
TODAY. SOUTHWEST WINDS WILL BECOME QUITE GUSTY BY AFTERNOON. THE
FRONT WILL CROSS NORTHERN MICHIGAN TONIGHT AND TUESDAY...WITH ONLY A
SMALL CHANCE FOR A FEW SHOWERS. A LARGE AREA OF HIGH PRESSURE WILL
MOVE INTO THE REGION LATE THIS WEEK AND INTO THE WEEKEND...PROVIDING
QUITE WEATHER.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 251 AM EDT MON SEP 24 2012
DEFINITE SIGNS OF CHANGE ACROSS THE NORTH WOODS EARLY THIS
MORNING...WITH CORE OF COLD ANOMALIES AND CENTER OF TROUGH AXIS THAT
HAS PLAGUED THE REGION FOR THE LAST SEVERAL DAYS NOW ROTATING OFF TO
OUR NORTHEAST. NO DOUBT TROUGHING STILL DOMINATES...BUT OFF THE DECK
WAA ALREADY BEGINNING TO REAR ITS HEAD ON NORTH SIDE OF SURFACE HIGH
PRESSURE ROTATING THROUGH THE OHIO VALLEY. DECREASING OVER-WATER
INSTABILITY VIA SLIGHT WARMING H85 TEMPERATURES (UP TO NEAR 0C PER
LATEST HIGH RES RAP GUIDANCE) AND ONSLAUGHT OF DEEP LAYER DRYING
(H85 NEGATIVE UPPER SINGLE DIGIT DEWPOINTS OVER NORTHERN LAKE
MICHIGAN) HAS NOT ONLY ESSENTIALLY SHUT OFF THE LAKE INDUCED SHOWER
MACHINE...BUT PUT A SERIOUS DENT IN EVEN LAKE CLOUD FORMATION.
THUS...SKIES HAVE CONTINUED TO CLEAR ACROSS MUCH OF OUR AREA...
ALTHOUGH HIGH CLOUDS HAVE BEGUN TO FILTER INTO UPPER MICHIGAN ON
FRONT END OF STRONG UPPER LEVEL JET STREAK AND ATTENDANT MID LEVEL
WAVE ROTATING SOUTH OUT OF WESTERN ONTARIO. COMBO OF CLEARING SKIES
AND QUICK LOSS OF WINDS THIS EVENING HAS ALLOWED TEMPERATURES TO
TANK...WITH READINGS ALREADY DIPPING WELL INTO THE 30S ACROSS
INTERIOR REGIONS SOUTH OF THE MIGHTY MAC. LIGHT WINDS WILL BE A
SHORT EVENT...WITH ALREADY SIGNS OF INCREASING WINDS OFF THE SURFACE
PER LATEST GUIDANCE. THIS IS JUST A BEGINNING OF THINGS TO COME...
WITH STRONG PRESSURE GRADIENT AND APPROACHING UPPER JET CORE ONLY
ENHANCING DOWN LOW WIND RESPONSE...FIRST OVER THE BIG WATERS BY
MORNING...AND ACROSS ALL AREAS AFTER SUNRISE. PRIMARY FORECAST
CONCERNS CENTER ON WIND SPEEDS AND ASSOCIATED POTENTIAL
HEADLINES...WITH LOW END SHOWER THREAT FROM APPROACHING EARLIER
MENTIONED WAVE A SECONDARY CONCERN.
FIRST THINGS FIRST...AND WILL LET FROST ADVISORY RUN ITS COURSE
THROUGH THE EARLY MORNING...WITH CURRENT TEMPERATURE TRENDS
SUPPORTING LOWS BY SUNRISE DIPPING INTO THE LOWER 30S IN THE
TRADITIONAL ICE BOX LOCATIONS. OTHERWISE...BIGGEST STORY TODAY WILL
BE THE WINDS...WHICH RAMP-UP QUICKLY THIS MORNING AS LOW LEVEL JET
INTENSIFIES OVERHEAD...WITH 950MB WINDS PUSHING 30 TO 40 KNOTS BY
18Z...WITH SPEEDS PUSHING 45 KNOTS UP THROUGH NORTHERN LAKE MICHIGAN
AND THE STRAITS. DESPITE WAA REGIME...GUIDANCE REMAINS STEADFAST OF
GOOD MIXING WELL PAST THIS LAYER...UP TO 850MBS...ESPECIALLY OVER
THE BIG WATERS WHERE CONDITIONS WILL REMAIN SOMEWHAT UNSTABLE.
BUFKIT MOMENTUM TRANSFER PROGS SUGGEST A GOOD PORTION OF ELEVATED
WINDS WILL MIX DOWN...SUPPORTING WIDESPREAD WIND GUSTS BY EARLY
AFTERNOON PUSHING 30 TO 35 MPH OVER MOST INTERIOR REGIONS. BIGGEST
CONCERN REMAINS UP ALONG THE NORTHWEST LOWER COASTLINE AND IN THE
STRAITS REGION WHERE CORE OF JET AND INSTABILITY IS MAXIMIZED OVER
OPEN WATER. COULD EASILY SEE 45 MPH GUSTS ALONG THE IMMEDIATE COASTS
FROM LEELANAU COUNTY UP INTO MACKINAC COUNTY...INCLUDING BEAVER
ISLAND. WILL GO AHEAD AND PULL THE TRIGGER ON A WIND ADVISORY FOR
THESE AREAS FROM LATE MORNING RIGHT THROUGH THE AFTERNOON HOURS.
SHOULD BE BELOW ADVISORY LEVELS ELSEWHERE...ALTHOUGH DO HAVE SOME
CONCERN FOR NORTHWEST BENZIE COUNTY AS WELL AS THE IMMEDIATE
SHORELINE OF IOSCO COUNTY OVER NORTHEAST LOWER AS WINDS FUNNEL UP
SAGINAW BAY. WILL HOLD OFF FOR THESE AREAS...BUT DEFINITELY PASS
THIS CONCERN ON TO THE INCOMING CREW.
OTHER STORY TODAY WILL BE LATE DAY RAIN CHANCES ACROSS EASTERN UPPER
AND THE TIP OF THE MITT AS ONTARIO WAVE AND ATTENDANT COLD FRONT
DROP INTO THE AREA. DYNAMICS NOT TOO SHABBY...WITH GOOD CORE OF MID
LEVEL -DIVQ OVERTOPPING DECENT BAND OF LOW LEVEL CONVERGENCE. LACK
OF MOISTURE REMAINS A BIG DETERRENT TO RAIN POTENTIAL...WITH
PRE-FRONTAL MOISTURE ADVECTION ANEMIC AT BEST...AS H85 DEWPOINTS
ONLY APPROACH 1C. GIVEN ABOVE...WILL MAKE LITTLE CHANGE TO INHERITED
LATE DAY LOW END POPS ACROSS THE FAR NORTH. GUSTY SOUTHWEST WINDS
WORK THEIR MAGIC...TACKING ON A GOOD 10 TO 15 DEGREES TO HIGH
TEMPERATURES EXPERIENCED THE LAST COUPLE DAYS. LOOK FOR AFTERNOON
READINGS ACTUALLY PUSHING LEVELS MUCH CLOSER TO NORMAL...WITH HIGHS
WELL INTO THE 60S!
FRONT SLOWLY SAGS SOUTH THROUGH THE OVERNIGHT AS MID LEVEL SUPPORT
BEGINS TO SHEAR OUT. MOISTURE PROFILES CHANGE LITTLE...WITH JUST A
NARROW AND RELATIVELY LIMITED SLUG OF MOISTURE ACCOMPANYING THE
FRONT. CAN`T ENTIRELY RULE OUT A LIGHT SHOWER...BUT FEEL MOST AREAS
AND MOST OF THE TIME WILL REMAIN DRY. WINDS DECREASE SUBSTANTIALLY
THROUGH THE EVENING AS MIXING IS LOST AND LOW LEVEL JET PIVOTS OFF
TO THE EAST. A MILD OVERNIGHT COMPARED TO RECENT TIMES...WITH LOWS
ONLY DROPPING INTO THE 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 251 AM EDT MON SEP 24 2012
A RELATIVELY UNEVENTFUL WORK WEEK IS AHEAD...AS THE UPPER FLOW OVER
THE CONUS AND SOUTHERN CANADA DEAMPLIFIES SOMEWHAT. THE UPPER LOW
OVER NORTHERN QUEBEC WILL EJECT NE-WARD TOWARD MID-WEEK...THOUGH IT
WILL DRAG ONE LAST UPPER TROF ACROSS THE LAKES REGION ON WEDNESDAY.
BUT BY THEN...A LARGE AREA OF HIGH PRESSURE WILL BE CENTERED OVER
THE WESTERN LAKES. THE COLD FRONT TALKED ABOUT IN THE SHORT-TERM
SECTION ABOVE...WILL SLOWLY MOVE SOUTH OF NORTHERN MI TUESDAY AND
TUE NIGHT.
TUESDAY...COLD FRONT WILL START THE MORNING ALONG ROUGHLY AN LDM-APN
LINE...WITH A WEAK SURFACE WAVE NEAR LDM. THE WAVE...AND THUS THE
FRONT...WILL GET HELD UP AS THEY BOTH FEEL A PROMINENT SHORTWAVE
DIGGING TOWARD NORTHERN SUPERIOR BY THE END OF THE DAY. AT THAT
TIME...THE FRONT WILL BE JUST OUT OF SE SECTIONS OF THE FORECAST
AREA....WITH THE SURFACE WAVE OVER SAGINAW BAY. BEHIND THE FRONT...A
SURFACE RIDGE AXIS WILL POKE EASTWARD ACROSS UPPER MI AND SOUTHERN
SUPERIOR.
THE SURFACE WAVE...AND LOCALLY BACKED FLOW OFF OF LAKE HURON...WILL
PRODUCE A PROMINENT AREA OF 1000-850MB CONVERGENCE...ALONG AND SE OF
AN APN-HTL LINE. HOWEVER...EVEN IF SURFACE DEW POINTS GET BOOSTED TO
50F IN THIS AREA PER NAM SOUNDINGS (AND FOR NOW EVEN THAT LOOKS
OPTIMISTIC)...UPDRAFTS WILL BE CAPPED OFF AT 625MB/-5C. NO ICE
EXPECTED IN THESE CLOUDS...AND NOT SURE THAT PRECIP GENERATED VIA
WARM RAIN PROCESSES WILL GET THRU THE RELATIVELY DRY AIR BELOW CLOUD
BASE/825MB. MUCAPE ONLY TOPS OUT AT 100J/KG. WILL MODIFY PRECIP
WORDING SLIGHTLY...GOING WITH A SMALL CHANCE FOR SPRINKLES (INSTEAD
OF OUTRIGHT SHOWERS) IN THE AFTERNOON IN PARTS OF NE LOWER.
ELSEWHERE...SCT DIURNAL CU AND/OR LAKE STRATOCU WILL BE PRESENT
(POST-FRONTAL DELTA T/S NEAR 15C OFF OF SUPERIOR AND FAR NORTHERN
LOWER LAKE MI). MAX TEMPS WILL RANGE FROM UPPER 50S IN EASTERN UPPER
MI...TO THE LOWER 70S IN THE FAR SE.
TUE NIGHT/WEDNESDAY...COLD FRONT MOVES TO FAR SOUTHERN LOWER MI BY
WED MORNING. HIGH PRESSURE MOVES FROM CENTRAL CANADA EARLY TUESDAY
NIGHT...TO WESTERN UPPER MI BY WED EVENING. THE BUILDING HIGH WILL
PROVIDE QUIET WX FOR MOST OF NORTHERN MI. HOWEVER...WE MAY SEE SOME
PRECIP CHANCES EMERGE UP NEAR SUPERIOR. A DIGGING SHORTWAVE REACHES
SUPERIOR WED MORNING. LOW LEVEL COLD ADVECTION CONTINUES...WITH
850MB TEMPS LOWERING NEAR 0C. A SURFACE TROF AXIS WILL AID
CONVERGENCE AND MOISTURE POOLING BELOW THE 725MB INVERSION. WILL ADD
A CHANCE OF SHRA TO PARTS OF CHIPPEWA CO LATE TUE NIGHT AND
ESPECIALLY WED MORNING. ELSEWHERE...MOSTLY CLEAR TO PARTLY CLOUDY
SKIES WILL WAY TO A HEALTHY CU FIELD BY EARLY AFTERNOON WED. MIN
TEMPS UPPER 30S TO LOWER 40S. MAX TEMPS MIDDLE 50S TO LOWER 60S.
REST OF THE FORECAST...EXTENDED MODELS AGREE THAT THE HIGH PRESSURE
IN PLACE BY WED NIGHT WILL BE DIFFICULT TO DISLODGE. IN FACT...IT
LOOKS TO BE REINFORCED OUT TOWARD FRIDAY. A DYING COLD FRONT MAY TRY
TO MOVE IN THURSDAY NIGHT AHEAD OF THE NEXT HIGH...BUT IT HAS NO
MOISTURE TO WORK WITH...AND ANY SORT OF DYNAMICS ARE UP TOWARD JAMES
BAY. THE EXTENDED WILL BE DEVOID OF ANY PRECIP. BELOW-NORMAL TEMPS
ON THURSDAY WILL MODERATE CLOSER TO NORMAL FOR THE WEEKEND.
WEDNESDAY NIGHT STILL LOOKS TO HAVE CONSIDERABLE FROST POTENTIAL IN
THE USUAL INLAND LOCALES...THE FORECAST WILL CONTINUE TO REFLECT
THIS. THURSDAY NIGHT COULD ALSO HAVE SOME FROST CONCERNS...THOUGH
LIKELY NOT AS MANY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1150 PM EDT SUN SEP 23 2012
HIGH PRESSURE WILL SLIDE SOUTH OF MICHIGAN OVERNIGHT. LOW LEVEL
WINDS WILL CONTINUE TO SHIFT FROM W TO W/SW...AND SOME WARMING
ALOFT WILL TAKE PLACE OVERNIGHT AS GRADIENT TIGHTENS AHEAD OF
ANOTHER APPROACHING FRONT. REMAINING LAKE EFFECT RAIN SHOWERS WILL
END OVERNIGHT IN RESPONSE TO DIMINISHING OVER-LAKE INSTABILITY.
VFR CONDITIONS WILL BE THE RULE THRU MONDAY NIGHT DESPITE RESIDUAL
SHOWER ACTIVITY AND ANOTHER APPROACHING (MOISTURE-STARVED) FRONT.
HOWEVER...WINDS WILL RAPIDLY STRENGTHEN FROM THE SW MONDAY MORNING...
WITH GUSTS TO 30-35 KTS EXPECTED AHEAD OF THE FRONT.
&&
.MARINE...
ISSUED AT 251 AM EDT MON SEP 24 2012
PRESSURE GRADIENT TIGHTENS THROUGH THE DAY AHEAD OF A COLD
FRONT THAT WILL SLIP THROUGH THE AREA TONIGHT. WITH REMAINING OVER
WATER INSTABILITY...VERY GUSTY WINDS WILL DEVELOP THIS MORNING AND
THROUGH THE AFTERNOON. GALE FORCE GUSTS ARE CERTAIN ON THE LAKE
MICHIGAN NEARSHORE AREAS AND THROUGH THE STRAITS. LESS CERTAINTY FOR
REACHING GALE FORCE ON THE LAKE HURON SIDE AS WELL AS WHITEFISH
BAY/SAINT MARYS RIVER. BUT GUSTINESS OVER LAND WILL LIKELY EXTEND
OUT INTO THE WATER...AND WILL THUS CONTINUE INHERITED GALE WARNINGS
FOR ALL NEARSHORE ZONES INTO TONIGHT. CONDITIONS WILL IMPROVE
THROUGH THE OVERNIGHT...WITH GALES LIKELY ENDING ALL AREAS WELL
BEFORE SUNRISE.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR MIZ017-018-
022>024-026>036-041-042.
WIND ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR MIZ015-016-019-020.
LH...GALE WARNING FROM 8 AM THIS MORNING TO 5 AM EDT TUESDAY FOR
LHZ345>349.
LM...GALE WARNING FROM 8 AM THIS MORNING TO 5 AM EDT TUESDAY FOR
LMZ323-341-342-344>346.
LS...GALE WARNING FROM 8 AM THIS MORNING TO 11 PM EDT THIS EVENING
FOR LSZ321-322.
&&
$$
SYNOPSIS...JZ
SHORT TERM...MB
LONG TERM...JZ
AVIATION...MR
MARINE...BA/MB
AREA FORECAST DISCUSSION
NWS BUFFALO NY
944 PM EDT TUE SEP 25 2012
.SYNOPSIS...
HIGH PRESSURE THAT BROUGHT BROUGHT A FAIR AMOUNT OF SUNSHINE AND
MILD TEMPERATURES DURING THE AFTERNOON...WILL SLIDE OUT INTO THE
ATLANTIC TONIGHT. MEANWHILE...A COLD FRONT APPROACHING FROM THE
CENTRAL GREAT LAKES WILL BRING A CHANCE FOR SHOWERS LATE TONIGHT AND
WEDNESDAY. HIGH PRESSURE FOLLOWING THE FRONT WILL BRING A RETURN TO
DRY CONDITIONS ON THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
HIGH PRESSURE MOVE FURTHER OUT INTO THE ATLANTIC TONIGHT AND
WEDNESDAY. AS THE HIGH SLIDES TO THE EAST...A COLD FRONT OVER THE
MIDWEST WILL MOVE TO THE EAST AND APPROACH LAKE ERIE LATE TONIGHT.
IR SATELLITE SHOWS AN AREA OF CLOUDS ASSOCIATED WITH AN UPPER
LEVEL DISTURBANCE AND A MODEST LOW LEVEL JET TO 40 KTS. INDEED THE
00Z BUFFALO SOUNDING SHOWS SOME ELEVATED CAPE BASED AT 800
MB...BUT THERE ARE SIGNIFICANT DRY AIR BENEATH THIS. THERE ARE
SOME SHOWERS ASSOCIATED WITH THIS FEATURE...BUT THEY ARE GENERALLY
ON THE LIGHT SIDE...STRUGGLING TO REACH THE GROUND IN SOME SPOTS.
THE NOSE OF THE WEAK LOW LEVEL JET IS SPARKING A FAST MOVING AREA
OF SHOWERS ACROSS CENTRAL NEW YORK. THESE INITIALLY STRUGGLED TO
REACH THE GROUND...BUT AS OF 900 PM...OBS SHOW AT LAST DSV HAS MANAGED
TO MEASURE. EXPECT THIS AREA TO CONTINUE TO QUICKLY LIFT TO THE
NORTHEAST...BRINGING A MARGINALLY MEASURABLE SHOWERS TO POINTS
EAST OF ROCHESTER...BUT SOUTHEAST OF WATERTOWN. THERE AS A LARGER
AREA OF LIGHT SHOWERS ACROSS WESTERN PENNSYLVANIA...WHICH WILL
CLIP THE SOUTHERN TIER LATE THIS EVENING.
12Z GUIDANCE HAS NOT HANDLED THIS TERRIBLY WELL...WITH THE GFS
WELL OVERDONE (AND SINCE BACKED OFF AS OF THE 18Z RUN). THE NAM
WAS TOO DRY...WITH THE RGEM NOT TOO BAD. OF THE AVAILABLE
MODELS...RECENT RUNS OF THE HRRR ARE DOING A BETTER JOB OF
INITIALIZING...AND SHOULD PROVE USEFUL OVERNIGHT. THIS WAVE IS
MOVING QUITE QUICKLY...AND AFTER IT EXITS...EXPECT THE CWA TO
MAINLY BE DRY FOR PART OF THE OVERNIGHT HOURS. IT IS INTERESTING
TO NOTE THE HRRR (WITH SUPPORT FROM THE RGEM) DEVELOP A LAKE
ENHANCED BAND OF SHOWERS TOWARD DAYBREAK IN A SSW FLOW. 850MB
TEMPERATURES ARE NOT COLD ENOUGH FOR PURE LAKE EFFECT RAIN
SHOWERS...BUT IT DOES APPEAR THE SLIGHTLY HIGHER TEMPERATURES AND
DEW POINTS ON LAKE ERIE WILL HELP SHOWERS DEVELOP JUST AHEAD OF
THE FRONT.
ON WEDNESDAY...THE COLD FRONT WILL PUSH ACROSS WESTERN AND
CENTRAL NEW YORK DURING THE AFTERNOON WHILE THE WAVE ALONG THE
FRONT TRACKS NORTH OF THE STATE. SINCE THE LOW LEVEL JET AND
DEEPER MOISTURE ARE FORECAST TO PUSH INTO EASTERN NEW YORK AND NEW
ENGLAND DURING THE AFTERNOON...THE STEADIEST PCPN SHOULD STAY TO
OUR EAST.
REGARDING TEMPERATURES...THE SOUTHERLY FLOW AHEAD OF THE FRONT WILL
KEEP CONDITIONS MILD TONIGHT...WITH READINGS EXPECTED TO RANGE FROM
THE MID 50S TO LOWER 60S. THE ANTICIPATED CLOUD COVER AND CHANCE FOR
SHOWERS WILL KEEP TEMPERATURES MAINLY IN THE 60S ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
THE UPSHOT FOR THIS PERIOD IS THAT WE WILL EXPERIENCE MAINLY DRY
WEATHER WITH TEMPERATURES AVERAGING WITHIN A COUPLE DEGREES OF
NORMAL. IN A COUPLE WORDS...VERY UNEVENTFUL.
LOOKING AT THE OVERALL PATTERN FOR THIS TIME FRAME...
A RELATIVELY FLAT SPLIT FLOW OVER THE LOWER 48 WILL UNDERGO
AMPLIFICATION DURING THIS PERIOD...AS A DEEP TROUGH WILL ONCE AGAIN
BECOME ESTABLISHED OVER THE GREAT LAKES. THE IMPETUS FOR THIS NEXT
PATTERN CHANGE WILL BE AN INNOCUOUS LOOKING SHORTWAVE THAT IS
CROSSING THE MACKENZIE RIVER VALLEY/GREAT SLAVE LAKE REGION. WHILE
THIS FEATURE IS STILL DIFFICULT TO DISCERN ON WV IMAGERY...GUIDANCE
HAS BEEN CONSISTENT WITH IDENTIFYING AND TRACKING THE BUNDLE OF
ENERGY ACROSS THE NORTHWEST TERRITORIES TO HUDSON BAY BY THURSDAY
WHERE IT WILL THEN DIVE SOUTH TOWARDS THE GREAT LAKES...CARVING OUT
THE NEXT TROUGH OVER EASTERN CANADA.
MEANWHILE AT THE SFC...HIGH PRESSURE OVER THE UPPER GREAT LAKES WILL
GRADUALLY BUILD ACROSS SOUTHERN ONTARIO TO NEW ENGLAND. AS THE
AFOREMENTIONED SHORTWAVE DIVES SOUTH TOWARDS THE GREAT LAKES REGION
TOWARDS THE END OF THIS TIME PERIOD...IT WILL START TO EXHIBIT
ITSELF AT THE SFC IN THE FORM OF AN INVERTED TROUGH OVER THE LOWER
LAKES. IT IS THIS FEATURE THAT MAY BRING A TOUCH OF `WEATHER` TO OUR
FORECAST AREA. NOW FOR SOME DAY TO DAY DETAILS...
A SLOW MOVING SFC FRONTAL BOUNDARY WILL BE IN THE PROCESS OF EXITING
OUR FORECAST AREA WEDNESDAY EVENING WHILE SHOWERS WILL BE TAPERING
OFF FROM WEST TO EAST. DURING THE COURSE OF THE NIGHT...HIGH
PRESSURE OVER THE U.P. WILL SETTLE ACROSS THE REMAINDER OF THE GREAT
LAKES. WHILE THIS WILL HELP TO PUSH MUCH DRIER MID LEVEL AIR ACROSS
OUR REGION...A WEALTH OF LOW LEVEL MOISTURE SHOULD ONLY ALLOW FOR
PARTIAL CLEARING. IMPROVING CONDITIONS SOUTHEAST OF LAKE ONTARIO MAY
BE EVEN FURTHER DELAYED BECAUSE OF LAKE INSTABILITY THAT WILL SET UP
WITHIN THE COLD ADVECTION. H85 TEMPS ARE FORECAST TO DROP TO ARND 2C
OVERNIGHT...AND THIS WILL LEAD TO LICAPES OF UP TO 500 J/KG WITH A
CAP IN THE VCNTY OF 8-10K FT. WHILE THIS SHOULD ALLOW FOR SOME LAKE
DRIVEN CLOUDINESS TO DEVELOP...THERE WILL PROBABLY BE TOO MUCH MID
LEVEL DRY AIR TO SUPPORT MESOSCALE SHOWERS. TEMPERATURES WEDNESDAY
NIGHT WILL BE ABOUT 10 DEG F LOWER THAN THOSE FROM THE PREVIOUS
NIGHT AS MINS WILL BE IN THE 40S.
THE SFC HIGH WILL DRIFT ACROSS THE LOWER GREAT LAKES ON THURSDAY.
WHILE FAIR WEATHER IS EXPECTED...A FAIRLY STRONG SUBSIDENCE
INVERSION SHOULD LIMIT THE AMOUNT OF DIURNAL MIXING OF THE MID LEVEL
DRY AIR TO THE SFC. UNDER THIS CAP...STEEP LAPSE RATES >10C DEG/KM
SHOULD PROMOTE THE DEVELOPMENT OF STRATO-CU (`SELF DESTRUCT SUN`)
WHICH MAY BE AIDED BY THE UPSLOPE NORTH TO NORTHWEST LOW LEVEL FLOW.
WILL GO HIGHER THAN GUIDANCE WITH THE CLOUD COVER...BUT WILL
COMPROMISE BY AIMING FOR PARTLY SUNNY SKIES. MAX TEMPS SHOULD BE
WITHIN A FEW DEGREES OF 60 F.
THURSDAY NIGHT WILL FEATURE DRY WEATHER AND SEASONABLY COOL
TEMPERATURES. THE QUESTION FOR THIS INDIVIDUAL PERIOD IS THE CLOUD
COVER. LEFTOVER DIURNAL CU WILL QUICKLY COLLAPSE/DISSIPATE DURING
THE EVENING...BUT MAY THEN POSSIBLY BEING REPLACED LATER AT NIGHT AS
ATLANTIC MOISTURE IS FORECAST TO ADVECT BACK ACROSS OUR SRN TIER
WITHIN THE CLOCKWISE CIRCULATION AROUND THE SFC HIGH. ANY SHOWERS
FROM THIS LOW LEVEL MOISTURE SHOULD REMAIN WELL TO OUR SOUTH.
A ROBUST SHORTWAVE WILL DIG SOUTH FROM JAMES BAY FRIDAY AND FRIDAY
NIGHT WHILE TROUGING IN THE MID LEVELS WILL FINALLY WORK ITS WAY TO
THE SFC. THE INVERTED SFC TROUGH OVER OUR FORECAST AREA WILL COMBINE
WITH THE RETURN FLOW FROM A SFC HIGH OVER NEW ENGLAND TO SEND A
SURGE OF ATLANTIC MOISTURE ACROSS CENTRAL AND EASTERN NEW YORK. THIS
WILL TRANSLATE INTO INCREASINGLY CLOUDY SKIES...AND POSSIBLY SOME
LIGHT SHOWERS...EAST OF THE GENESEE VALLEY/FINGER LAKES WHILE NICER
CONDITIONS WILL PERSIST OVER THE FAR WESTERN COUNTIES. AFTERNOON
TEMPS FRIDAY WILL BE IN THE LOW TO MID 60S WHILE OVERNIGHT LOWS WILL
AGAIN BE IN THE 40S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
A REX BLOCK FOUND OVER EASTERN CANADA AND THE GREAT LAKES AT THE
START OF THIS PERIOD WILL EVENTUALLY BREAK DOWN AND GIVE WAY TO A
NEAR ZONAL FLOW ALONG THE U.S. CANADIAN BORDER. THIS WILL LEAD TO
MODERATING TEMPERATURES THAT WILL AVERAGE WELL ABOVE NORMAL BY THE
MIDDLE OF THE WEEK.
BEFORE THIS CAN ALL HAPPEN THOUGH...ANOMALOUSLY STRONG RIDGING OVER
THE NORTHERN PLAINS AND EASTERN QUEBEC SATURDAY AND SUNDAY WILL
CRADLE A CLOSED LOW IN THE VCNTY OF LAKE HURON. THIS SCENARIO WAS
ACCEPTED FROM THE ECMWF AND GEFS. THE OPERATIONAL GFS WAS STILL THE
OUTLIER IN ITS OVERALL H5 PATTERN DURING THIS PERIOD SO IT WAS
TOTALLY DISREGARDED WITH THIS PACKAGE.
CONTINUING...THE DIVERGENT UPPER LEVEL FLOW AROUND THE EAST SIDE OF
THE CLOSED LOW WILL FAVOR THE DEVELOPMENT OF A SFC LOW SOMEWHERE
ALONG THE MID ATLANTIC COAST. THE EASTERLY LOW LEVEL FLOW BETWEEN
THIS SFC LOW AND HIGH PRESSURE OVER THE CANADIAN MARITIMES WILL FEED
MORE ATLANTIC MOISTURE WESTWARD BACK ACROSS THE ADIRONDACKS TO
CENTRAL NEW YORK AND AT LEAST THE FINGER LAKES REGION. THIS IS ALSO
WHERE SOME SHOWER ACTIVITY COULD BE FOUND OVER THE WEEKEND...BUT
CONFIDENCE IN THIS SCENARIO IS NOT STRONG. FURTHER TO THE
WEST...MAINLY DRY WEATHER IS ANTICIPATED FOR THE WESTERN COUNTIES.
TEMPERATURES BOTH DAYS WILL GENERALLY REACH THE MID 60S.
AS WE PUSH OUT OF THE WEEKEND INTO THE FIRST PART OF THE NEW WORK
WEEK...A SHORTWAVE RIDGE AHEAD OF AN UPSTREAM `KICKER` WILL DISLODGE
THE CLOSED LOW AND TEMPORARILY SET UP A ZONAL FLOW ACROSS THE GREAT
LAKES REGION. THE RISING HGTS WILL BE ACCOMPANIED BY MODERATING H85
TEMPS SO THAT FAIR WEATHER WILL RETURN TO THE ENTIRE REGION WITH
NEAR SFC TEMPS TRENDING UPWARDS TO ABV NORMAL LEVELS. FROM THIS
VANTAGE POINT...TUESDAY LOOKS LIKE IT COULD BE QUITE NICE INDEED.
LOOKING FURTHER AHEAD INTO THE SECOND HALF OF THE WEEK...SIGNIFICANT
RIDGING IN THE EAST SHOULD LEAD TO SEVERAL DAYS OF MILD (IF NOT
WARM) DAYS WITH PLENTY OF SUN. THERE IS A HIGH PROBABILITY THAT
TEMPS FOR THE SECOND HALF OF THE WEEK WILL AVERAGE WELL ABV NORMAL.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
ALTHOUGH A SCATTERED SHOWERS WILL CLIP SOUTHERN PARTS OF WESTERN
NEW YORK...EXPECT THESE WILL BE ON THE LIGHT SIDE WITH VFR
CONDITIONS LIKELY THROUGH THIS EVENING. AFTER THIS...LOW LEVEL
MOISTURE WILL INCREASE AHEAD OF AN APPROACHING COLD FRONT...WHICH
SHOULD LOWER CIGS AT MOST SITES...MAINLY IN THE MVFR
CATEGORY...WITH THIS OCCURRING IN THE 06Z TO 12Z TIMEFRAME.
THE FRONT WILL SLOWLY CROSS FROM NW TO SE DURING THE DAY
WEDNESDAY...AND THIS MAY SPARK SHOWERS WITH ITS PASSAGE. THE SW
FLOW AHEAD OF THE FRONT WILL ALSO PICK UP ADDITIONAL MOISTURE OFF
THE LAKES...WHICH WILL LIKELY RESULT IN THE LOWEST CIGS...PERHAPS
A PERIOD OF IFR OR LOWER. EXPECT A MODEST IMPROVEMENT WITH THE
FRONTAL PASSAGE...WITH CIGS TRENDING UPWARDS TOWARD 00Z THURSDAY.
AN ISOLATED AFTERNOON THUNDERSTORM CANNOT BE RULED OUT...HOWEVER
TSTMS WILL LIKELY BE TO THE SOUTH AND EAST OF OUR TAF LOCATIONS.
OUTLOOK...
WEDNESDAY NIGHT...MVFR IMPROVING TO VFR.
THURSDAY THRU SUNDAY...MAINLY VFR.
&&
.MARINE...
HIGH PRESSURE HAS SLID FURTHER OFF THE NEW JERSEY COAST...ALLOWING
WINDS TO DIMINISH LATE THIS AFTERNOON. THIS HAS ALLOWED US TO DROP
THE SMALL CRAFT ADVISORY ON ALL OF OUR WATERS. EXPECT WIND AND WAVES TO
REMAIN BELOW SCA CONDITIONS ON WEDNESDAY.
A NORTHWEST FLOW OF COOLER AIR BEHIND THE FRONT MAY CAUSE WAVES TO
BUILD TO NEAR SCA CRITERIA FOR AWHILE WEDNESDAY NIGHT...BEFORE THE
GRADIENT RELAXES AS HIGH PRESSURE BUILDS EAST ACROSS THE LAKES
DURING THE SECOND HALF OF THE NIGHT.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TJP
NEAR TERM...APFFEL/TJP
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...APFFEL
MARINE...APFFEL/TJP
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
734 AM EDT MON SEP 24 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL CONTINUE ACROSS THE REGION
TODAY...WITH A FEW SPRINKLES POSSIBLE OVER THE WESTERN ADIRONDACK
MOUNTAINS AND PARTS OF THE NORTHEAST KINGDOM OF VERMONT.
OTHERWISE...SURFACE HIGH PRESSURE ACROSS THE MID ATLANTIC STATES
WILL RESULT IN MAINLY DRY CONDITIONS WITH NEAR NORMAL TEMPERATURES
THROUGH TUESDAY. THE NEXT SURFACE COLD FRONT WILL PRODUCE SCATTERED
SHOWERS ON WEDNESDAY...ALONG WITH SLIGHTLY COOLER TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 715 AM EDT MONDAY...QUICK UPDATE TO ALLOW FROST ADVISORY TO
EXPIRE AND MENTION AREAS OF PATCHY FOG. ALSO...INCREASED CLOUDS
SOME BASED ON OBSERVATIONS AND WEB CAMS. RAP SOUNDING SHOW PLENTY
OF BL RH THRU 14Z AT MPV...SO EXPECT FOG TO SLOWLY BURN OFF ACRS
THE DEEPER CENTRAL VT VALLEYS THIS MORNING. A GREAT RANGE IN TEMPS
THIS MORNING FROM 28F AT SLK TO 52F NEAR LAKE CHAMPLAIN...SO HAVE
POPULATED WITH CRNT OBS AND INTERPOLATED THRU TIME. HIGHS WL RANGE
FROM THE M/U 50S DACKS/NEK TO L/M 60S CPV/SLV.
MID/UPPER LVL TROF WL CONT ACRS THE FA TODAY. FCST CHALLENGE WL BE
CHCS FOR LAKE EFFECT ACTIVITY THIS MORNING SOUTHERN SLV/WESTERN
DACKS AND POTENTIAL FOR A FEW ISOLATED SHOWERS NEK. MESOSCALE
MODELS SHOW BEST 1000 TO 700MB RH AND SFC TO 850 UVVS FIELDS
ASSOCIATED WITH LAKE ACTIVITY LIFTING NORTH TWD SLV...BUT GIVEN
WEAK CLOUD LAYER WINDS...PRECIP WL HAVE DIFFICULTIES REACHING OUR
CWA. IN ADDITION...0 TO 3 KM SHEAR INCREASES AS WINDS TURN TO THE
SOUTHWEST AND LLVL WAA DEVELOPS. WL MENTION SCHC POPS WESTERN CWA
THIS MORNING. OTHERWISE...WITH MID/UPPER LVL TROF AXIS ACRS OUR
CWA AND SOME EMBEDDED 850 TO 500MB MOISTURE ALONG WITH WEAK S/W
ENERGY WHICH ENHANCES 850 TO 500MB Q-VECTOR CONVERGENCE ACRS OUR
CENTRAL/NORTHERN VT ZNS...WL MENTION SCHC POPS. GIVEN LIMITED DEEP
LAYER MOISTURE ACTIVITY WL BE LIGHT AND QPF VERY MINIMAL. TEMPS WL
BE TRICKY WITH WEAK LLVL CAA CONTINUING THRU 15Z...THEN WAA
DEVELOPS ON SOUTHWEST FLW AFT 18Z...WITH PROGGED 85H TEMPS NEAR 2C
BY 00Z TUES. GIVEN THE HIGH OF 66 AT BTV YESTERDAY...WL TREND
SLIGHTLY ABOVE GUIDANCE WITH SIMILAR LLVL THERMAL PROFILE
ANTICIPATED TODAY...THINKING M/U 50S DACKS/NEK/VT MTNS TO L/M60S
CT VALLEY/CPV/SLV.
TONIGHT...SFC HIGH PRES SHIFTS INTO THE MID ATLANTIC STATES AND PRES
GRADIENT INCREASES AS NEXT TROF APPROACHES THE SLV AFT 06Z TUES.
THIS SW FLW WL AID IN LLVL WAA WITH PROGGED 85H TEMPS WARMING BTWN
3-5C BY 12 TUES. HOWEVER...WINDS WL DECOUPLE IN DEEPER MTN VALLEYS
AND GIVEN MAINLY CLR SKIES...EXPECT SOME TEMPS IN THE 30S WITH
PATCHY FROST POSSIBLE. MID/UPPER SLOPE THERMAL BELT LOOKS
LIKE...GIVEN SOUNDING PROFILE WITH TEMPS IN THE 40S.
ALSO...ANTICIPATE LOWS IN THE U30S TO M40S CPV/SLV. CLOUDS WL
INCREASE ACRS THE SLV TWD SUNRISE AS NEXT S/W APPROACHES...BUT
PRECIP SHOULD STAY NW OF OUR CWA.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 415 AM EDT SUNDAY...THE SHORT TERM FCST CHALLENGE WL BE
TIMING OF SYSTEMS AND PLACEMENT OF PRECIP CHCS ACRS OUR FA. STILL
SOME UNCERTAINTY WITH REGARDS TO PLACEMENT OF BEST DEEP LAYER
MOISTURE AND S/W ENERGY ASSOCIATED WITH APPROACHING TROF.
FIRST...PIECE OF ENERGY SHEAR APART ACRS THE SLV ON TUES
MORNING...WITH BEST 850 TO 500MB RH STAYING JUST NORTH OF OUR CWA.
WL MENTION SCHC POPS...OTHERWISE REST OF TUES WL BE DRY. 85H TEMPS
WARM BTWN 6 AND 8C BY 00Z WEDS AND SUPPORT HIGHS BACK INTO THE
L60S MTNS/NEK TO NEAR 70F CPV/SLV. TUES NIGHT TEMPS WL BE TRICKY
AS MOISTURE INCREASE FROM THE SOUTH AND GRADIENT CONTS ACRS OUR
CWA. WL KEEP TEMPS ON THE WARMER SIDE OF GUIDANCE...WITH COLDEST
READINGS ACRS THE NEK OF VT. ALSO...WL MENTION CHC POPS TUES NIGHT
SOUTHERN/CENTRAL VT ASSOCIATED WITH INCREASED MOISTURE AND S/W
ENERGY IN FAST WESTERLY FLW ALOFT. SOME UNCERTAINTY TO HOW FAR
NORTH THIS MOISTURE/ENERGY WL BE AND POTENTIAL IMPACT...BUT
OVERALL QPF IF ANY WL BE LIGHT.
WEDS...MID/UPPER LVL TROF DEEPENS ACRS THE NE CONUS AS ANOTHER SFC
COLD FRNT PUSHES THRU THE NORTH COUNTRY. LATEST TRENDS SHOW TWO
AREAS OF PRECIP FOR WEDS. ONE IS LOCATED ACRS THE MID ATLANTIC/SNE
AREA ASSOCIATED WITH OHIO VALLEY MOISTURE/ENERGY AND ANOTHER IS OVER
OUR CWA WITH FRNT/DIGGING TROF. THIS ACTIVITY ACRS THE MID
ATLANTIC/SNE MAY LIMIT DEEPER MOISTURE FROM GETTING INTO OUR
CWA...RESULTING IN LESS OVERALL COVERAGE OF PRECIP AND LIGHTER QPF
AMOUNTS. IN ADDITION...BREEZY SW TO WEST FLW OFF THE DACKS WL LIMIT
QPF AMOUNTS ACRS THE CPV...LOOKING LIKE A HIGH POP/LOW QPF EVENT FOR
MOST OF OUR CWA. TEMPS WL BE HIGHLY DEPEND UPON IF ANY SUNSHINE
OCCURS. THINKING A FEW BREAKS WL BE POSSIBLE ACRS THE CPV/CT RIVER
VALLEY WITH SW DOWNSLOPE FLW AND TEMPS WL WARM INTO THE U60S TO
M70S...ELSEWHERE MAINLY TEMPS IN THE 60S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 418 AM EDT MONDAY...QUIET WEATHER THROUGH THE END OF THE
WEEK...THEN APPROACHING LOW PRESSURE SYSTEM RESULTS IN LOW
CONFIDENCE FORECAST FOR THE WEEKEND.
WEDNESDAY NIGHT THE COLD FRONT WILL QUICKLY THROUGH THE FORECAST
AREA...WITH LINGERING POST FRONTAL SHOWERS UNDER THE TRAILING
UPPER LEVEL VORTICITY MAX WEDNESDAY NIGHT. THURSDAY WILL BE THE
COOLEST DAY OF THE EXTENDED PERIOD WITH 850 MB TEMPS 0 TO +4C
ACROSS THE REGION SUPPORTING MAX TEMPS IN THE MID/UPPER 50S. AS
HIGH PRESSURE BUILDS COLDEST TEMPS SHIFT EAST AND WILL SEE A SLOW
MODERATING TREND THROUGH THE END OF THE WEEK...BUT STILL BELOW NORMAL.
PROBLEMATIC PART OF THE FORECAST BEGINS WITH 500MB CLOSED LOW
MOVING THROUGH SOUTHERN MANITOBA IN NORTHWEST FLOW THURSDAY
NIGHT...PAUSING OVER MONTREAL SATURDAY...THEN RETROGRADING
SOUTHWEST UP THE SAINT LAWRENCE VALLEY THROUGH SUNDAY. ODD
BEHAVIOR IN A LOW AND AT FIRST DISCOUNTED GFS SOLUTION...THEN
ECMWF CAME IN WITH SIMILAR TREND. LITTLE PRECIP WITH THE LOW WHEN
IT FIRST MOVES INTO REGION ON SATURDAY...THEN AS IT MOVES
SOUTHWEST WILL TAP INTO ATLANTIC MOISTURE SOURCE AND POPS INCREASE
TO CHANCE CATEGORY SATURDAY NIGHT INTO SUNDAY. GIVEN DAY 7
CONFIDENCE LOW ANYWAY...AND THIS TYPE OF TRACK HAS EVEN LOWER
CONFIDENCE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
THROUGH 12Z TUESDAY....IFR FG/FZFG KSLK KMPV AND KMSS WILL IMPROVE
TO VFR THROUGH 14Z. VFR ALL TAF SITES TODAY...WITH CONDITIONS
SIMILAR TO YESTERDAY. WIND TO COME AROUND TO SOUTH TO
SOUTHWEST. AFT 08Z MVFR VIS IN BR POSSIBLE KSLK/KMPV.
OUTLOOK 12Z TUESDAY THROUGH FRIDAY...
12Z TUESDAY THROUGH 12Z WEDNESDAY...PRIMARILY VFR ALTHOUGH
RESTRICTIONS POSSIBLE IN EARLY MORNING FOG/BR...MAINLY SLK/MPV.
12Z WEDNESDAY THROUGH 12Z THURSDAY...MAINLY VFR WITH SCATTERED
MVFR RAIN SHOWERS POSSIBLE WITH COLD FRONT PASSAGE.
12Z THURSDAY ONWARD...VFR UNDER BUILDING HIGH PRESSURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...HANSON
AVIATION...HANSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
720 AM EDT MON SEP 24 2012
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL CONTINUE ACROSS THE REGION
TODAY...WITH A FEW SPRINKLES POSSIBLE OVER THE WESTERN ADIRONDACK
MOUNTAINS AND PARTS OF THE NORTHEAST KINGDOM OF VERMONT.
OTHERWISE...SURFACE HIGH PRESSURE ACROSS THE MID ATLANTIC STATES
WILL RESULT IN MAINLY DRY CONDITIONS WITH NEAR NORMAL TEMPERATURES
THROUGH TUESDAY. THE NEXT SURFACE COLD FRONT WILL PRODUCE SCATTERED
SHOWERS ON WEDNESDAY...ALONG WITH SLIGHTLY COOLER TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 715 AM EDT MONDAY...QUICK UPDATE TO ALLOW FROST ADVISORY TO
EXPIRE AND MENTION AREAS OF PATCHY FOG. ALSO...INCREASED CLOUDS
SOME BASED ON OBSERVATIONS AND WEB CAMS. RAP SOUNDING SHOW PLENTY
OF BL RH THRU 14Z AT MPV...SO EXPECT FOG TO SLOWLY BURN OFF ACRS
THE DEEPER CENTRAL VT VALLEYS THIS MORNING. A GREAT RANGE IN TEMPS
THIS MORNING FROM 28F AT SLK TO 52F NEAR LAKE CHAMPLAIN...SO HAVE
POPULATED WITH CRNT OBS AND INTERPOLATED THRU TIME. HIGHS WL RANGE
FROM THE M/U 50S DACKS/NEK TO L/M 60S CPV/SLV.
MID/UPPER LVL TROF WL CONT ACRS THE FA TODAY. FCST CHALLENGE WL BE
CHCS FOR LAKE EFFECT ACTIVITY THIS MORNING SOUTHERN SLV/WESTERN
DACKS AND POTENTIAL FOR A FEW ISOLATED SHOWERS NEK. MESOSCALE
MODELS SHOW BEST 1000 TO 700MB RH AND SFC TO 850 UVVS FIELDS
ASSOCIATED WITH LAKE ACTIVITY LIFTING NORTH TWD SLV...BUT GIVEN
WEAK CLOUD LAYER WINDS...PRECIP WL HAVE DIFFICULTIES REACHING OUR
CWA. IN ADDITION...0 TO 3 KM SHEAR INCREASES AS WINDS TURN TO THE
SOUTHWEST AND LLVL WAA DEVELOPS. WL MENTION SCHC POPS WESTERN CWA
THIS MORNING. OTHERWISE...WITH MID/UPPER LVL TROF AXIS ACRS OUR
CWA AND SOME EMBEDDED 850 TO 500MB MOISTURE ALONG WITH WEAK S/W
ENERGY WHICH ENHANCES 850 TO 500MB Q-VECTOR CONVERGENCE ACRS OUR
CENTRAL/NORTHERN VT ZNS...WL MENTION SCHC POPS. GIVEN LIMITED DEEP
LAYER MOISTURE ACTIVITY WL BE LIGHT AND QPF VERY MINIMAL. TEMPS WL
BE TRICKY WITH WEAK LLVL CAA CONTINUING THRU 15Z...THEN WAA
DEVELOPS ON SOUTHWEST FLW AFT 18Z...WITH PROGGED 85H TEMPS NEAR 2C
BY 00Z TUES. GIVEN THE HIGH OF 66 AT BTV YESTERDAY...WL TREND
SLIGHTLY ABOVE GUIDANCE WITH SIMILAR LLVL THERMAL PROFILE
ANTICIPATED TODAY...THINKING M/U 50S DACKS/NEK/VT MTNS TO L/M60S
CT VALLEY/CPV/SLV.
TONIGHT...SFC HIGH PRES SHIFTS INTO THE MID ATLANTIC STATES AND PRES
GRADIENT INCREASES AS NEXT TROF APPROACHES THE SLV AFT 06Z TUES.
THIS SW FLW WL AID IN LLVL WAA WITH PROGGED 85H TEMPS WARMING BTWN
3-5C BY 12 TUES. HOWEVER...WINDS WL DECOUPLE IN DEEPER MTN VALLEYS
AND GIVEN MAINLY CLR SKIES...EXPECT SOME TEMPS IN THE 30S WITH
PATCHY FROST POSSIBLE. MID/UPPER SLOPE THERMAL BELT LOOKS
LIKE...GIVEN SOUNDING PROFILE WITH TEMPS IN THE 40S.
ALSO...ANTICIPATE LOWS IN THE U30S TO M40S CPV/SLV. CLOUDS WL
INCREASE ACRS THE SLV TWD SUNRISE AS NEXT S/W APPROACHES...BUT
PRECIP SHOULD STAY NW OF OUR CWA.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 415 AM EDT SUNDAY...THE SHORT TERM FCST CHALLENGE WL BE
TIMING OF SYSTEMS AND PLACEMENT OF PRECIP CHCS ACRS OUR FA. STILL
SOME UNCERTAINTY WITH REGARDS TO PLACEMENT OF BEST DEEP LAYER
MOISTURE AND S/W ENERGY ASSOCIATED WITH APPROACHING TROF.
FIRST...PIECE OF ENERGY SHEAR APART ACRS THE SLV ON TUES
MORNING...WITH BEST 850 TO 500MB RH STAYING JUST NORTH OF OUR CWA.
WL MENTION SCHC POPS...OTHERWISE REST OF TUES WL BE DRY. 85H TEMPS
WARM BTWN 6 AND 8C BY 00Z WEDS AND SUPPORT HIGHS BACK INTO THE
L60S MTNS/NEK TO NEAR 70F CPV/SLV. TUES NIGHT TEMPS WL BE TRICKY
AS MOISTURE INCREASE FROM THE SOUTH AND GRADIENT CONTS ACRS OUR
CWA. WL KEEP TEMPS ON THE WARMER SIDE OF GUIDANCE...WITH COLDEST
READINGS ACRS THE NEK OF VT. ALSO...WL MENTION CHC POPS TUES NIGHT
SOUTHERN/CENTRAL VT ASSOCIATED WITH INCREASED MOISTURE AND S/W
ENERGY IN FAST WESTERLY FLW ALOFT. SOME UNCERTAINTY TO HOW FAR
NORTH THIS MOISTURE/ENERGY WL BE AND POTENTIAL IMPACT...BUT
OVERALL QPF IF ANY WL BE LIGHT.
WEDS...MID/UPPER LVL TROF DEEPENS ACRS THE NE CONUS AS ANOTHER SFC
COLD FRNT PUSHES THRU THE NORTH COUNTRY. LATEST TRENDS SHOW TWO
AREAS OF PRECIP FOR WEDS. ONE IS LOCATED ACRS THE MID ATLANTIC/SNE
AREA ASSOCIATED WITH OHIO VALLEY MOISTURE/ENERGY AND ANOTHER IS OVER
OUR CWA WITH FRNT/DIGGING TROF. THIS ACTIVITY ACRS THE MID
ATLANTIC/SNE MAY LIMIT DEEPER MOISTURE FROM GETTING INTO OUR
CWA...RESULTING IN LESS OVERALL COVERAGE OF PRECIP AND LIGHTER QPF
AMOUNTS. IN ADDITION...BREEZY SW TO WEST FLW OFF THE DACKS WL LIMIT
QPF AMOUNTS ACRS THE CPV...LOOKING LIKE A HIGH POP/LOW QPF EVENT FOR
MOST OF OUR CWA. TEMPS WL BE HIGHLY DEPEND UPON IF ANY SUNSHINE
OCCURS. THINKING A FEW BREAKS WL BE POSSIBLE ACRS THE CPV/CT RIVER
VALLEY WITH SW DOWNSLOPE FLW AND TEMPS WL WARM INTO THE U60S TO
M70S...ELSEWHERE MAINLY TEMPS IN THE 60S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 418 AM EDT MONDAY...QUIET WEATHER THROUGH THE END OF THE
WEEK...THEN APPROACHING LOW PRESSURE SYSTEM RESULTS IN LOW
CONFIDENCE FORECAST FOR THE WEEKEND.
WEDNESDAY NIGHT THE COLD FRONT WILL QUICKLY THROUGH THE FORECAST
AREA...WITH LINGERING POST FRONTAL SHOWERS UNDER THE TRAILING
UPPER LEVEL VORTICITY MAX WEDNESDAY NIGHT. THURSDAY WILL BE THE
COOLEST DAY OF THE EXTENDED PERIOD WITH 850 MB TEMPS 0 TO +4C
ACROSS THE REGION SUPPORTING MAX TEMPS IN THE MID/UPPER 50S. AS
HIGH PRESSURE BUILDS COLDEST TEMPS SHIFT EAST AND WILL SEE A SLOW
MODERATING TREND THROUGH THE END OF THE WEEK...BUT STILL BELOW NORMAL.
PROBLEMATIC PART OF THE FORECAST BEGINS WITH 500MB CLOSED LOW
MOVING THROUGH SOUTHERN MANITOBA IN NORTHWEST FLOW THURSDAY
NIGHT...PAUSING OVER MONTREAL SATURDAY...THEN RETROGRADING
SOUTHWEST UP THE SAINT LAWRENCE VALLEY THROUGH SUNDAY. ODD
BEHAVIOR IN A LOW AND AT FIRST DISCOUNTED GFS SOLUTION...THEN
ECMWF CAME IN WITH SIMILAR TREND. LITTLE PRECIP WITH THE LOW WHEN
IT FIRST MOVES INTO REGION ON SATURDAY...THEN AS IT MOVES
SOUTHWEST WILL TAP INTO ATLANTIC MOISTURE SOURCE AND POPS INCREASE
TO CHANCE CATEGORY SATURDAY NIGHT INTO SUNDAY. GIVEN DAY 7
CONFIDENCE LOW ANYWAY...AND THIS TYPE OF TRACK HAS EVEN LOWER
CONFIDENCE.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
THROUGH 06Z TUESDAY....VFR THROUGH THE TAF PERIOD...EXCEPT FOR
SHORT TEMPO PRE-DAWN KMPV FOR MVFR VIS. SCATTERED CLOUDS FORECAST
TODAY...WITH SOUTH TO SOUTHWEST SURFACE WINDS. KMSS COULD SEE SOME
GUSTS TO 20 KTS AS WINDS CHANNELED DOWN SAINT LAWRENCE VALLEY.
OUTLOOK 06Z TUESDAY THROUGH FRIDAY...
06Z TUESDAY THROUGH 12Z WEDNESDAY...PRIMARILY VFR ALTHOUGH
RESTRICTIONS POSSIBLE IN EARLY MORNING FOG/BR...MAINLY SLK/MPV.
12Z WEDNESDAY THROUGH 12Z THURSDAY...MAINLY VFR WITH SCATTERED
MVFR RAIN SHOWERS POSSIBLE WITH COLD FRONT PASSAGE.
12Z THURSDAY ONWARD...VFR UNDER BUILDING HIGH PRESSURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...HANSON
AVIATION...HANSON
AREA FORECAST DISCUSSION
NWS BUFFALO NY
453 AM EDT MON SEP 24 2012
.SYNOPSIS...
LAKE EFFECT RAIN SHOWERS WILL LINGER EAST OF THE LAKES THIS
MORNING...BUT THEN WILL TAPER OFF AS HIGH PRESSURE BUILDS ACROSS THE
OHIO VALLEY TODAY. DRY WEATHER WILL CONTINUE THROUGH TUESDAY AS
TEMPERATURES WARM BACK CLOSE TO AVERAGE. A WEAK AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE GREAT LAKES ON
WEDNESDAY AND BRING THE NEXT CHANCE OF SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY TODAY...AS AN UPPER
LEVEL TROF EXITS TO THE EAST. OUTSIDE OF LAKE EFFECT RAIN SHOWERS
TODAY WOULD BE A DRY DAY. HOWEVER...AT 400 AM RADAR SHOWS QUITE A
SIGNIFICANT AREA OF LAKE EFFECT RAIN SHOWERS AND THUNDERSTORMS ON
LAKE ONTARIO...WITH MORE SPARSE COVERAGE OF SHOWERS OFF LAKE ERIE.
OFF LAKE ERIE...LAKE EFFECT RAIN SHOWERS...AND PERHAPS AN ISOLATED
THUNDERSTORM WILL LIFT FROM CHAUTAUQUA AND CATTARAUGUS COUNTIES
DURING THE EARLY MORNING HOURS...INTO SOUTHERN ERIE THROUGH
MID-MORNING AS THE FLOW BECOMES MORE SOUTHWESTERLY. THE HRRR HINTS
AT A THE BRIEF DEVELOPMENT OF AN ORGANIZED BAND ALONG THE SHORELINE
AND INTO SOUTHERN ERIE COUNTY...WHICH IS PLAUSIBLE BUT NOT A
LIKELIHOOD. ANY SUCH BAND WOULD BE SHORT LIVED AS SOUTHWESTERLY WINDS
PICK UP AND BRING IN WARMER AIR ALOFT WHICH EVENTUALLY CAP LAKE
EFFECT SHOWERS. THIS BAND WILL PROBABLY END AS AN AREA OF CLOUDS
LIFTING ACROSS BUFFALO/ROCHESTER...THOUGH STRAY LATE MORNING OR
EARLY AFTERNOON SHOWER CAN/T BE RULED OUT.
OF LAKE ONTARIO...A FAIRLY WELL DEVELOPED BAND WILL LIKELY PERSIST
THROUGH 12Z...AND THEN BECOME LESS ORGANIZED AS IT LIFTS NORTHWARD
THIS MORNING. UNTIL THEN...EXPECT SOME FAIRLY SIGNIFICANT SHOWERS
AND THUNDERSTORMS BOTH ON THE OPEN WATERS...AND IN WESTERN PORTIONS
OF OSWEGO COUNTY. QPFS WILL VARY...BUT RAINFALL RATES OF A QUARTER
TO HALF INCH AN HOUR ARE POSSIBLE THROUGH DAYBREAK AS BANDS WORK ON
SHORE. GIVEN THE CLOSE PROXIMITY TO THE LAKE...THIS IS NOT LIKELY TO
CAUSE FLOODING...BUT LOCATIONS BETWEEN NINE MILE POINT AND SANDY
CREEK MAY SEE SOME BRIEF HEAVY DOWNPOURS. AFTER THIS...THE BAND WILL
LIFT INTO JEFFERSON COUNTY...AND WEAKEN AS IT REACHES NORTHERN
JEFFERSON COUNTY. ELSEWHERE...QPFS WILL BE MUCH LESS...WITH WEAK FLOW
SHOWERS SHOULD NOT MAKE IT TOO FAR INLAND...WITH ONLY SCATTERED
SHOWERS IN LEWIS COUNTY.
OTHERWISE...SKIES SHOULD CLEAR OUT BEHIND ALL OF THIS LAKE INDUCED
CLOUD AND SHOWER ACTIVITY. IT WILL BE ON THE CHILLY SIDE
TODAY...ESPECIALLY AS A SOUTHWESTERLY BREEZE DEVELOPS. HIGHS SHOULD
BE SIMILAR TO YESTERDAY...TOPPING OUT IN THE UPPER 50S TO NEAR 60 IN
MOST LOCATIONS.
FOR TONIGHT...SOUTHWESTERLY WINDS ALOFT WILL INCREASE TO 40 KTS. IN
MOST AREAS...THESE WILL NOT MIX DOWN...BUT SHOULD PROVIDE ENOUGH
MIXING TO KEEP TEMPERATURES FROM DROPPING MUCH AT ALL. OUTSIDE OF
THE MOST SHELTERED INTERIOR VALLEYS...SEE LITTLE RISK FOR FROST
TONIGHT. ACROSS THE NIAGARA FRONTIER...EXPECT A BREEZE TO PERSIST
MUCH OF THE NIGHT. THIS SHOULD KEEP TEMPERATURES IN THE LOWER TO MID
50S...WHICH IS ABOVE MOST MOS GUIDANCE.
DESPITE THE WINDS ALOFT...THERE SHOULD BE NO SENSIBLE WEATHER WITH
THIS DISTURBANCE...WITH FAIR WEATHER AND MAINLY CLEAR SKIES TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
TUESDAY WILL FEATURE A CLOSED LOW ALOFT CENTERED JUST TO THE SOUTH
OF HUDSON BAY WITH SEVERAL EMBEDDED VORTICITY MAXES CIRCULATING
AROUND THIS LOW. ANOTHER FEATURE ALOFT...AND SUBTLE...IS A
LITTLE SHORTWAVE CROSSING THE CENTRAL PLAINS FROM THE LEE OF THE
ROCKIES. AT THE SFC HIGH PRESSURE WILL BE SETTLED JUST OFF THE MID
ATLANTIC COASTLINE WHILE A FRONTAL ZONE WILL BE DRAPED ACROSS THE
CENTRAL GREAT LAKES AND DOWN TOWARDS THE SOUTHERN PLAINS.
THIS PATTERN WILL FEATURE WARM AIR ADVECTION THROUGH THE DAY ON
TUESDAY. A 925-850 HPA LOW LEVEL JET OF 30 TO 40 KNOTS WILL BE
STREAMING ACROSS THE REGION TO START THE DAY...AIDING IN BOTH THE
WARM AIR RETURNING ACROSS THE EASTERN GREAT LAKES...AS WELL AS
TRANSPORTING MOISTURE INTO THE REGION.
WITH THE PRESSURE GRADIENT AND LOW LEVEL JET STRONGEST TUESDAY
MORNING EXPECT WINDS TO BECOME GUSTY AS SOON AS THE MORNING
INVERSION IS ERODED. THERE IS A SOUTHWEST ALIGNED FLOW THROUGH 5K
FEET AND EXPECT WIND GUSTS UP TOWARDS 25 TO 35 MPH THROUGH THE
DAY...WITH THE STRONGEST WIND GUSTS DOWNWIND OF BOTH GREAT LAKES AND
THROUGH THE SAINT LAWRENCE VALLEY.
AS WE PROGRESS THROUGH THE DAY TUESDAY THE SUBTLE SHORTWAVE ACROSS
THE CENTRAL PLAINS...COMBINED WITH ISENTROPIC LIFT...WILL INCREASE
CLOUDS THROUGH THE AFTERNOON HOURS. WITH THE PRESSURE GRADIENT AT
THE SFC RELAXING SOME WITH THE SFC HIGH NOW OFF THE NEW ENGLAND
COASTLINE AND CLOUDS INCREASING...EXPECT THE WIND AND WIND GUSTS TO
BE PEAKING WITH THE INCREASING CLOUDS.
MODEL SOUNDINGS INCREASE MOISTURE IN THE MID LEVELS SUPPORTING
INCREASING CLOUDS THROUGH THE AFTERNOON FROM SOUTHWEST TO
NORTHEAST...HOWEVER A DRY LAYER BENEATH THIS MOISTURE WILL LIKELY
DELAY ANY RAIN SHOWERS FROM REACHING THE GROUND UNTIL LATE AFTERNOON
ACROSS FAR WESTERN NY...AND THEN EVENING ELSEWHERE. AHEAD OF THE
COLD FRONT TUESDAY NIGHT WITH THE ISENTROPIC LIFT CONTINUING AND
MOISTURE ADVECTION INCREASING EXPECT A BROAD AREA OF RAIN FROM THE
OHIO VALLEY TO PUSH INTO AND ACROSS MUCH OF THE REGION. RAINFALL
WILL REMAIN LIGHT...AND CONFIDENCE WILL LEAVE POPS STILL WITHIN THE
CHANCE RANGE FOR TUESDAY NIGHT. A BLEND OF MODEL GUIDANCE FOR
RAINFALL GIVES MANY AREAS AROUND A TENTH OF AN INCH OR LESS...WITH
THE AXIS OF HEAVIEST OF THE RAIN AWAY FROM THE LAKE PLAIN.
TEMPERATURES ON TUESDAY WILL CONTINUE TO MODERATE RANGING FROM
NORMAL TO ABOVE NORMAL VALUES WITH THE SOUTHWESTERLY WIND AND 850
HPA TEMPERATURES CLIMBING TO +8 TO +10C. HIGHS WILL RISE INTO THE
60S IN THE AFTERNOON WITH SEVERAL 70S POSSIBLE ACROSS FAVORED
DOWNSLOPE AREAS OF THE LAKE PLAIN AND GENESEE VALLEY. WITH CLOUDS
LINGERING THROUGH THE NIGHT AND YET AHEAD OF THE COLD FRONT
OVERNIGHT LOWS WILL BE MILD...WITH TEMPERATURES ONLY DROPPING OFF
INTO THE 50S.
ON WEDNESDAY A SHORTWAVE ROUNDING THE UPPER LEVEL CUT OFF WILL DRIVE
A COLD FRONT ACROSS THE CWA. EXPECT ANOTHER ROUND OF RAIN
SHOWERS...THIS TIME WITH THE COLD FRONT FROM WEST TO EAST WEDNESDAY.
WHILE INSTABILITY REMAINS VERY MARGINAL...WITH JUST 250 TO 500 J/KG
OF SBCAPE...HAVE DECIDED TO INCLUDE ISOLATED THUNDER WEDNESDAY
AFTERNOON AND EVENING AHEAD OF THE COLD FRONT. THE COLD FRONT WILL
PUSH ACROSS THE CWA THROUGH THE AFTERNOON AND EVENING HOURS WITH THE
SHOWERS ENDING LATE AFTERNOON TO THE FAR WEST AND THEN THROUGH THE
EVENING HOURS TOWARDS THE EAST.
WITH COLD AIR ALOFT POURING ACROSS THE REGION WEDNESDAY NIGHT A
COLDER NIGHT IS IN STORE WITH LOWS DROPPING BACK INTO THE
40S...POSSIBLY LINGERING IN THE 50S NEAR THE SOUTHERN LAKE ONTARIO
SHORELINE WHERE SOME LAKE INDUCED/UPSLOPE CLOUDS MAY LINGER THROUGH
THE NIGHT. A FEW SHELTERED VALLEYS OF THE SOUTHERN TIER AND NORTH
COUNTRY MAY DIP INTO THE UPPER 30S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THIS PERIOD LOOKS TO START IN BETWEEN A DEPARTING TROUGH OFF THE EAST COAST
AND WHAT APPEARS TO BE ANOTHER SHORT WAVE FORECAST TO DIG SOUTH
ACROSS CENTRAL CANADA INTO THE GREAT LAKES/NORTHEAST FOR THE WEEKEND.
ON THURSDAY HIGH PRESSURE WILL PROVIDE A NICE FALL DAY WITH PLENTY
OF SUN SHINING THROUGH AFTERNOON CUMULUS AND LIGHT WINDS IN THE WAKE
OF WEDNESDAYS COLD FRONT. AFTER THIS POINT THERE IS A SPREAD IN THE
MEDIUM RANGE MODELS. WHILE BOTH MODELS SHOW A DIGGING TROUGH
RETURNING ACROSS THE GREAT LAKES/NORTHEAST...THE 12Z ECMWF IS MORE
PROGRESSIVE WITH SWINGING THE TROUGH TO THE COAST BUT THE 12Z GFS
DEVELOPS A CUT OFF LOW OVER LAKE ERIE.
THE GFS DEVELOPS A LOW AHEAD OF THE DIGGING UPPER TROUGH OVER THE
OHIO VALLEY FRIDAY AND LIFTS THAT ACROSS PA TO THE SOUTH OF THE
FORECAST AREA. THIS WOULD LEAD TO A CHANCE FOR SHOWERS ON FRIDAY AND
FRIDAY NIGHT FOR MAINLY PARTS OF THE SOUTHERN TIER AND SOUTHERN
FINGER LAKES WITH THE UPPER TROUGH CUTTING OFF OVER THE LAKES BEHIND
THE SYSTEM.
SUCH DIFFERENCES IN THE MODELS LEADS TO HIGH UNCERTAINTY IN THE
FORECAST. GENERALLY WENT WITH A BLEND OF 12Z MODEL GUIDANCE WITH
SOME HPC GUIDANCE TO PRODUCE THE FORECAST. TEMPS AVERAGE CLOSE TO
CLIMATOLOGY ALONG THE LINES OF THE MEXMOS. 60S FOR HIGHS AND 40S FOR
LOWS WITH NO THREAT OF FROST AT THIS TIME. POPS ARE ALL LOW CHANCE
AS WELL UNTIL MORE AGREEMENT CAN BE MADE IN THE MODELS.
TEMPS WILL RUN AROUND NORMAL FOR LATE SEPTEMBER.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
09Z THROUGH 18Z TODAY...THE MAIN CHALLENGE WILL BE LAKE EFFECT
RAIN SHOWERS. A WESTERLY FLOW JUST ABOVE THE SURFACE WILL KEEP
SHOWERS AND ASSOCIATED CLOUDS OUT OF MOST OF OUR TAF LOCATIONS
BUF/IAG/ROC/ART THROUGH 12Z. THE EXCEPTION IS JHW...WHERE THIS
FLOW WILL RESULT IN SHOWERS AND PERIODS OF MVFR CIGS. THE FLOW
ALOFT WILL SHIFT MORE SW BETWEEN 12Z AND 18Z WHICH WILL LIFT WHATS
LEFT OF THE ACTIVITY NORTHWARD. THIS MAY BRING A PERIOD OF 3000 TO
4000 CIGS TO BUF/IAG/ROC/ART AS THIS LEFT OVER MOISTURE LIFTS
NORTHWARD.
18Z TODAY THROUGH 06Z TUESDAY...EXPECT VFR CONDITIONS ACROSS THE
REGION THIS AFTERNOON AND OVERNIGHT. THE ONLY CONCERN FOR THIS
EVENING IS AN INCREASING SW FLOW...WITH WINDS FORECAST TO INCREASE
TO 40 KTS 2000 FT. THIS SHOULD MIX DOWN TO SOME DEGREE AT
BUF/IAG...BUT NOT SO MUCH AT JHW/ROC/ART. BECAUSE OF
THIS...INTRODUCED LLWS AT THE LATTER THREE SITES...WHILE KEEPING
GUSTS AT BUF/IAG TO INDICATE CONTINUED MIXING TONIGHT.
OUTLOOK...
TUESDAY...VFR.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
ALTHOUGH WINDS AND WAVES HAVE DIMINISHED EARLY THIS MORNING...THIS
BREAK WILL BE SHORT LIVED. ANOTHER SHORTWAVE WILL APPROACH FROM THE
UPPER LAKES THIS EVENING...WITH SOUTHWESTERLY WINDS FORECAST TO
INCREASE AHEAD OF THIS FEATURE. 925 MB WINDS ARE FORECAST TO
INCREASE TO 35 TO 40 KNOTS...WITH A SSW FLOW AT THE SURFACE. WHILE
THIS IS WARM AIR ADVECTION ALOFT...WITH RESPECT TO THE WATERS...THE
SURFACE TEMPERATURES ADVECTING OVER THE WATERS WILL BE COOLER THAN
THE WATER TEMPERATURE THIS EVENING. BECAUSE OF THIS...WENT ABOVE
MODEL GUIDANCE FOR SURFACE WIND SPEED...WITH STRONG SMALL CRAFT
ADVISORY CONDITIONS EXPECTED THIS EVENING. THERE IS EVEN A CHANCE OF
GALES...MAINLY ON WESTERN PORTIONS OF LAKE ONTARIO...THOUGH
CONFIDENCE IN THIS IS TOO LOW TO WARRANT THE GALE HEADLINE. EITHER
WAY...A SOLID 30 KNOT FLOW SHOULD PRODUCE WAVES TO 10 FEET ON THE
NORTH SHORES OF LAKE ERIE AND ONTARIO. WINDS WILL GRADUALLY DIMINISH
THROUGH TUESDAY...WITH HEADLINES TIL 22Z TUESDAY FOR ALL OF THE
NEARSHORES.
THE OTHER CONCERN ON THE WATERS IS THE POTENTIAL FOR WATERSPOUTS
THROUGH THIS MORNING. CONDITIONS WILL BE MOST FAVORABLE ON LAKE
ONTARIO THROUGH AROUND 15Z...AND ALTHOUGH WE HAVE NOT RECEIVE ANY
REPORTS YET...THERE ARE LIKELY SOME WATERSPOUTS EMBEDDED IN SOME OF
THE LAKE EFFECT RAIN SHOWERS AND THUNDERSTORMS ON LAKE ONTARIO...AND
POSSIBLY LAKE ERIE. THE POTENTIAL FOR WATERSPOUTS WILL DIMINISH THIS
AFTERNOON.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ021.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EDT
TUESDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO MIDNIGHT
EDT TONIGHT FOR LEZ020.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM
EDT TUESDAY FOR LOZ042>045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...THOMAS
LONG TERM...SMITH
AVIATION...APFFEL
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS BUFFALO NY
423 AM EDT MON SEP 24 2012
.SYNOPSIS...
LAKE EFFECT RAIN SHOWERS WILL LINGER EAST OF THE LAKES THIS
MORNING...BUT THEN WILL TAPER OFF AS HIGH PRESSURE BUILDS ACROSS THE
OHIO VALLEY TODAY. DRY WEATHER WILL CONTINUE THROUGH TUESDAY AS
TEMPERATURES WARM BACK CLOSE TO AVERAGE. A WEAK AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE GREAT LAKES ON
WEDNESDAY AND BRING THE NEXT CHANCE OF SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY TODAY...AS AN UPPER
LEVEL TROF EXITS TO THE EAST. OUTSIDE OF LAKE EFFECT RAIN SHOWERS
TODAY WOULD BE A DRY DAY. HOWEVER...AT 400 AM RADAR SHOWS QUITE A
SIGNIFICANT AREA OF LAKE EFFECT RAIN SHOWERS AND THUNDERSTORMS ON
LAKE ONTARIO...WITH MORE SPARSE COVERAGE OF SHOWERS OFF LAKE ERIE.
OFF LAKE ERIE...LAKE EFFECT RAIN SHOWERS...AND PERHAPS AN ISOLATED
THUNDERSTORM WILL LIFT FROM CHAUTAUQUA AND CATTARAUGUS COUNTIES
DURING THE EARLY MORNING HOURS...INTO SOUTHERN ERIE THROUGH
MID-MORNING AS THE FLOW BECOMES MORE SOUTHWESTERLY. THE HRRR HINTS
AT A THE BRIEF DEVELOPMENT OF AN ORGANIZED BAND ALONG THE SHORELINE
AND INTO SOUTHERN ERIE COUNTY...WHICH IS PLAUSIBLE BUT NOT A
LIKELIHOOD. ANY SUCH BAND WOULD BE SHORT LIVED AS SOUTHWESTERLY WINDS
PICK UP AND BRING IN WARMER AIR ALOFT WHICH EVENTUALLY CAP LAKE
EFFECT SHOWERS. THIS BAND WILL PROBABLY END AS AN AREA OF CLOUDS
LIFTING ACROSS BUFFALO/ROCHESTER...THOUGH STRAY LATE MORNING OR
EARLY AFTERNOON SHOWER CAN/T BE RULED OUT.
OF LAKE ONTARIO...A FAIRLY WELL DEVELOPED BAND WILL LIKELY PERSIST
THROUGH 12Z...AND THEN BECOME LESS ORGANIZED AS IT LIFTS NORTHWARD
THIS MORNING. UNTIL THEN...EXPECT SOME FAIRLY SIGNIFICANT SHOWERS
AND THUNDERSTORMS BOTH ON THE OPEN WATERS...AND IN WESTERN PORTIONS
OF OSWEGO COUNTY. QPFS WILL VARY...BUT RAINFALL RATES OF A QUARTER
TO HALF INCH AN HOUR ARE POSSIBLE THROUGH DAYBREAK AS BANDS WORK ON
SHORE. GIVEN THE CLOSE PROXIMITY TO THE LAKE...THIS IS NOT LIKELY TO
CAUSE FLOODING...BUT LOCATIONS BETWEEN NINE MILE POINT AND SANDY
CREEK MAY SEE SOME BRIEF HEAVY DOWNPOURS. AFTER THIS...THE BAND WILL
LIFT INTO JEFFERSON COUNTY...AND WEAKEN AS IT REACHES NORTHERN
JEFFERSON COUNTY. ELSEWHERE...QPFS WILL BE MUCH LESS...WITH WEAK FLOW
SHOWERS SHOULD NOT MAKE IT TOO FAR INLAND...WITH ONLY SCATTERED
SHOWERS IN LEWIS COUNTY.
OTHERWISE...SKIES SHOULD CLEAR OUT BEHIND ALL OF THIS LAKE INDUCED
CLOUD AND SHOWER ACTIVITY. IT WILL BE ON THE CHILLY SIDE
TODAY...ESPECIALLY AS A SOUTHWESTERLY BREEZE DEVELOPS. HIGHS SHOULD
BE SIMILAR TO YESTERDAY...TOPPING OUT IN THE UPPER 50S TO NEAR 60 IN
MOST LOCATIONS.
FOR TONIGHT...SOUTHWESTERLY WINDS ALOFT WILL INCREASE TO 40 KTS. IN
MOST AREAS...THESE WILL NOT MIX DOWN...BUT SHOULD PROVIDE ENOUGH
MIXING TO KEEP TEMPERATURES FROM DROPPING MUCH AT ALL. OUTSIDE OF
THE MOST SHELTERED INTERIOR VALLEYS...SEE LITTLE RISK FOR FROST
TONIGHT. ACROSS THE NIAGARA FRONTIER...EXPECT A BREEZE TO PERSIST
MUCH OF THE NIGHT. THIS SHOULD KEEP TEMPERATURES IN THE LOWER TO MID
50S...WHICH IS ABOVE MOST MOS GUIDANCE.
DESPITE THE WINDS ALOFT...THERE SHOULD BE NO SENSIBLE WEATHER WITH
THIS DISTURBANCE...WITH FAIR WEATHER AND MAINLY CLEAR SKIES TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
TUESDAY WILL FEATURE A CLOSED LOW ALOFT CENTERED JUST TO THE SOUTH
OF HUDSON BAY WITH SEVERAL EMBEDDED VORTICITY MAXES CIRCULATING
AROUND THIS LOW. ANOTHER FEATURE ALOFT...AND SUBTLE...IS A
LITTLE SHORTWAVE CROSSING THE CENTRAL PLAINS FROM THE LEE OF THE
ROCKIES. AT THE SFC HIGH PRESSURE WILL BE SETTLED JUST OFF THE MID
ATLANTIC COASTLINE WHILE A FRONTAL ZONE WILL BE DRAPED ACROSS THE
CENTRAL GREAT LAKES AND DOWN TOWARDS THE SOUTHERN PLAINS.
THIS PATTERN WILL FEATURE WARM AIR ADVECTION THROUGH THE DAY ON
TUESDAY. A 925-850 HPA LOW LEVEL JET OF 30 TO 40 KNOTS WILL BE
STREAMING ACROSS THE REGION TO START THE DAY...AIDING IN BOTH THE
WARM AIR RETURNING ACROSS THE EASTERN GREAT LAKES...AS WELL AS
TRANSPORTING MOISTURE INTO THE REGION.
WITH THE PRESSURE GRADIENT AND LOW LEVEL JET STRONGEST TUESDAY
MORNING EXPECT WINDS TO BECOME GUSTY AS SOON AS THE MORNING
INVERSION IS ERODED. THERE IS A SOUTHWEST ALIGNED FLOW THROUGH 5K
FEET AND EXPECT WIND GUSTS UP TOWARDS 25 TO 35 MPH THROUGH THE
DAY...WITH THE STRONGEST WIND GUSTS DOWNWIND OF BOTH GREAT LAKES AND
THROUGH THE SAINT LAWRENCE VALLEY.
AS WE PROGRESS THROUGH THE DAY TUESDAY THE SUBTLE SHORTWAVE ACROSS
THE CENTRAL PLAINS...COMBINED WITH ISENTROPIC LIFT...WILL INCREASE
CLOUDS THROUGH THE AFTERNOON HOURS. WITH THE PRESSURE GRADIENT AT
THE SFC RELAXING SOME WITH THE SFC HIGH NOW OFF THE NEW ENGLAND
COASTLINE AND CLOUDS INCREASING...EXPECT THE WIND AND WIND GUSTS TO
BE PEAKING WITH THE INCREASING CLOUDS.
MODEL SOUNDINGS INCREASE MOISTURE IN THE MID LEVELS SUPPORTING
INCREASING CLOUDS THROUGH THE AFTERNOON FROM SOUTHWEST TO
NORTHEAST...HOWEVER A DRY LAYER BENEATH THIS MOISTURE WILL LIKELY
DELAY ANY RAIN SHOWERS FROM REACHING THE GROUND UNTIL LATE AFTERNOON
ACROSS FAR WESTERN NY...AND THEN EVENING ELSEWHERE. AHEAD OF THE
COLD FRONT TUESDAY NIGHT WITH THE ISENTROPIC LIFT CONTINUING AND
MOISTURE ADVECTION INCREASING EXPECT A BROAD AREA OF RAIN FROM THE
OHIO VALLEY TO PUSH INTO AND ACROSS MUCH OF THE REGION. RAINFALL
WILL REMAIN LIGHT...AND CONFIDENCE WILL LEAVE POPS STILL WITHIN THE
CHANCE RANGE FOR TUESDAY NIGHT. A BLEND OF MODEL GUIDANCE FOR
RAINFALL GIVES MANY AREAS AROUND A TENTH OF AN INCH OR LESS...WITH
THE AXIS OF HEAVIEST OF THE RAIN AWAY FROM THE LAKE PLAIN.
TEMPERATURES ON TUESDAY WILL CONTINUE TO MODERATE RANGING FROM
NORMAL TO ABOVE NORMAL VALUES WITH THE SOUTHWESTERLY WIND AND 850
HPA TEMPERATURES CLIMBING TO +8 TO +10C. HIGHS WILL RISE INTO THE
60S IN THE AFTERNOON WITH SEVERAL 70S POSSIBLE ACROSS FAVORED
DOWNSLOPE AREAS OF THE LAKE PLAIN AND GENESEE VALLEY. WITH CLOUDS
LINGERING THROUGH THE NIGHT AND YET AHEAD OF THE COLD FRONT
OVERNIGHT LOWS WILL BE MILD...WITH TEMPERATURES ONLY DROPPING OFF
INTO THE 50S.
ON WEDNESDAY A SHORTWAVE ROUNDING THE UPPER LEVEL CUT OFF WILL DRIVE
A COLD FRONT ACROSS THE CWA. EXPECT ANOTHER ROUND OF RAIN
SHOWERS...THIS TIME WITH THE COLD FRONT FROM WEST TO EAST WEDNESDAY.
WHILE INSTABILITY REMAINS VERY MARGINAL...WITH JUST 250 TO 500 J/KG
OF SBCAPE...HAVE DECIDED TO INCLUDE ISOLATED THUNDER WEDNESDAY
AFTERNOON AND EVENING AHEAD OF THE COLD FRONT. THE COLD FRONT WILL
PUSH ACROSS THE CWA THROUGH THE AFTERNOON AND EVENING HOURS WITH THE
SHOWERS ENDING LATE AFTERNOON TO THE FAR WEST AND THEN THROUGH THE
EVENING HOURS TOWARDS THE EAST.
WITH COLD AIR ALOFT POURING ACROSS THE REGION WEDNESDAY NIGHT A
COLDER NIGHT IS IN STORE WITH LOWS DROPPING BACK INTO THE
40S...POSSIBLY LINGERING IN THE 50S NEAR THE SOUTHERN LAKE ONTARIO
SHORELINE WHERE SOME LAKE INDUCED/UPSLOPE CLOUDS MAY LINGER THROUGH
THE NIGHT. A FEW SHELTERED VALLEYS OF THE SOUTHERN TIER AND NORTH
COUNTRY MAY DIP INTO THE UPPER 30S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
THIS PERIOD LOOKS TO START IN BETWEEN A DEPARTING TROUGH OFF THE EAST COAST
AND WHAT APPEARS TO BE ANOTHER SHORT WAVE FORECAST TO DIG SOUTH
ACROSS CENTRAL CANADA INTO THE GREAT LAKES/NORTHEAST FOR THE WEEKEND.
ON THURSDAY HIGH PRESSURE WILL PROVIDE A NICE FALL DAY WITH PLENTY
OF SUN SHINING THROUGH AFTERNOON CUMULUS AND LIGHT WINDS IN THE WAKE
OF WEDNESDAYS COLD FRONT. AFTER THIS POINT THERE IS A SPREAD IN THE
MEDIUM RANGE MODELS. WHILE BOTH MODELS SHOW A DIGGING TROUGH
RETURNING ACROSS THE GREAT LAKES/NORTHEAST...THE 12Z ECMWF IS MORE
PROGRESSIVE WITH SWINGING THE TROUGH TO THE COAST BUT THE 12Z GFS
DEVELOPS A CUT OFF LOW OVER LAKE ERIE.
THE GFS DEVELOPS A LOW AHEAD OF THE DIGGING UPPER TROUGH OVER THE
OHIO VALLEY FRIDAY AND LIFTS THAT ACROSS PA TO THE SOUTH OF THE
FORECAST AREA. THIS WOULD LEAD TO A CHANCE FOR SHOWERS ON FRIDAY AND
FRIDAY NIGHT FOR MAINLY PARTS OF THE SOUTHERN TIER AND SOUTHERN
FINGER LAKES WITH THE UPPER TROUGH CUTTING OFF OVER THE LAKES BEHIND
THE SYSTEM.
SUCH DIFFERENCES IN THE MODELS LEADS TO HIGH UNCERTAINTY IN THE
FORECAST. GENERALLY WENT WITH A BLEND OF 12Z MODEL GUIDANCE WITH
SOME HPC GUIDANCE TO PRODUCE THE FORECAST. TEMPS AVERAGE CLOSE TO
CLIMATOLOGY ALONG THE LINES OF THE MEXMOS. 60S FOR HIGHS AND 40S FOR
LOWS WITH NO THREAT OF FROST AT THIS TIME. POPS ARE ALL LOW CHANCE
AS WELL UNTIL MORE AGREEMENT CAN BE MADE IN THE MODELS.
TEMPS WILL RUN AROUND NORMAL FOR LATE SEPTEMBER.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
06Z THROUGH 18Z TODAY...THE MAIN CHALLENGE WILL BE LAKE EFFECT RAIN
SHOWERS. A WESTERLY FLOW JUST ABOVE THE SURFACE WILL KEEP SHOWERS
AND ASSOCIATED CLOUDS OUT OF MOST OF OUR TAF LOCATIONS
BUF/IAG/ROC/ART. THE EXCEPTION HERE IS JHW...WHERE THIS FLOW WILL
RESULT IN SHOWERS AND PERIODS OF MVFR CIGS. THE FLOW ALOFT WILL
SHIFT MORE SW BETWEEN 12Z AND 18Z WHICH WILL LIFT WHATS LEFT OF
THE ACTIVITY NORTHWARD. THIS MAY BRING A PERIOD OF 3000 TO 4000
CIGS TO BUF/IAG/ROC/ART AS THIS LEFT OVER MOISTURE LIFTS
NORTHWARD.
18Z TODAY THROUGH 06Z TUESDAY...EXPECT VFR CONDITIONS ACROSS THE
REGION THIS AFTERNOON AND OVERNIGHT. THE ONLY CONCERN FOR THIS
EVENING IS AN INCREASING SW FLOW...WITH WINDS FORECAST TO INCREASE
TO 40 KTS 2000 FT. THIS SHOULD MIX DOWN TO SOME DEGREE AT
BUF/IAG...BUT NOT SO MUCH AT JHW/ROC/ART. BECAUSE OF
THIS...INTRODUCED LLWS AT THE LATTER THREE SITES...WHILE KEEPING
GUSTS AT BUF/IAG TO INDICATE CONTINUED MIXING TONIGHT.
OUTLOOK...
TUESDAY...VFR.
WEDNESDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
ALTHOUGH WINDS AND WAVES HAVE DIMINISHED EARLY THIS MORNING...THIS
BREAK WILL BE SHORT LIVED. ANOTHER SHORTWAVE WILL APPROACH FROM THE
UPPER LAKES THIS EVENING...WITH SOUTHWESTERLY WINDS FORECAST TO
INCREASE AHEAD OF THIS FEATURE. 925 MB WINDS ARE FORECAST TO
INCREASE TO 35 TO 40 KNOTS...WITH A SSW FLOW AT THE SURFACE. WHILE
THIS IS WARM AIR ADVECTION ALOFT...WITH RESPECT TO THE WATERS...THE
SURFACE TEMPERATURES ADVECTING OVER THE WATERS WILL BE COOLER THAN
THE WATER TEMPERATURE THIS EVENING. BECAUSE OF THIS...WENT ABOVE
MODEL GUIDANCE FOR SURFACE WIND SPEED...WITH STRONG SMALL CRAFT
ADVISORY CONDITIONS EXPECTED THIS EVENING. THERE IS EVEN A CHANCE OF
GALES...MAINLY ON WESTERN PORTIONS OF LAKE ONTARIO...THOUGH
CONFIDENCE IN THIS IS TOO LOW TO WARRANT THE GALE HEADLINE. EITHER
WAY...A SOLID 30 KNOT FLOW SHOULD PRODUCE WAVES TO 10 FEET ON THE
NORTH SHORES OF LAKE ERIE AND ONTARIO. WINDS WILL GRADUALLY DIMINISH
THROUGH TUESDAY...WITH HEADLINES TIL 22Z TUESDAY FOR ALL OF THE
NEARSHORES.
THE OTHER CONCERN ON THE WATERS IS THE POTENTIAL FOR WATERSPOUTS
THROUGH THIS MORNING. CONDITIONS WILL BE MOST FAVORABLE ON LAKE
ONTARIO THROUGH AROUND 15Z...AND ALTHOUGH WE HAVE NOT RECEIVE ANY
REPORTS YET...THERE ARE LIKELY SOME WATERSPOUTS EMBEDDED IN SOME OF
THE LAKE EFFECT RAIN SHOWERS AND THUNDERSTORMS ON LAKE ONTARIO...AND
POSSIBLY LAKE ERIE. THE POTENTIAL FOR WATERSPOUTS WILL DIMINISH THIS
AFTERNOON.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ021.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EDT
TUESDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO MIDNIGHT
EDT TONIGHT FOR LEZ020.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM
EDT TUESDAY FOR LOZ042>045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...THOMAS
LONG TERM...SMITH
AVIATION...APFFEL
MARINE...APFFEL/THOMAS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
755 PM EDT TUE SEP 25 2012
.SYNOPSIS...
AN AREA OF HIGH PRESSURE OFF THE VIRGINIA COAST WILL CONTINUE TO
EXTEND ACROSS THE CAROLINAS TONIGHT AND WEDNESDAY....THEN WEAKEN AND
DRIFT EAST BY THURSDAY. THIS WILL INITIATE A WARMING TREND RESULTING
IN ABOVE NORMAL AFTERNOON TEMPERATURES THROUGH THE REMAINDER OF THE
WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 PM TUESDAY...
1026MB SURFACE HIGH PRESSURE CENTERED JUST EAST OF NORFOLK THIS
EXTENDS SOUTH ALONG THE NC/SC COASTAL PLAIN THIS AFTERNOON.
SOUTHERLY RETURN FLOW AROUND THE HIGH HAS DEVELOPED ACROSS MOST OF
THE CWA...ALLOWING DEWPOINTS TO SLOWLY CREEP BACK INTO THE LOWER
50S. UPSTREAM CONVECTION OVER EASTERN KY IS MOSTLY ELEVATED...BUT
IS A LITTLE MORE IMPRESSIVE THAN HI-RES GUIDANCE SUGGESTED EARLIER
THIS MORNING. RAP FORECAST SOUNDINGS SUGGEST THE STRONG CAPPING
INVERSION ON THE 12Z KGSO RAOB HAS ERODED A BIT TODAY VIA WEAK
COOLING AROUND 700MB...WITH MODEST MID LEVEL LAPSE RATES ABOVE.
HOWEVER... PW EAST OF THE MOUNTAINS IS STILL AROUND 0.5" AND MUCAPE
IS VERY WEAK. ONLY THE MOST RECENT HRRR RUNS SHOW ANY SIMULATED
ECHOS EAST OF THE MOUNTAINS...AND EVEN THEN ARE ONLY A COUPLE
ISOLATED SHOWERS NEAR FORSYTH AND PERSON COUNTIES. WHILE THE RADAR
AND MODEL TRENDS ARE NOT DISCOUNTED...EXPECT THE ONLY IMPACT TO BE
FROM MID AND HIGH CLOUDS OVER THE NORTHWEST PIEDMONT THIS EVENING.
TONIGHT...
LOWS TONIGHT SHOULD NOT BE NEARLY AS COOL DUE TO THE DEWPOINT
RECOVERY TODAY...HELD HIGHER BY MORE CLOUD COVER OVER THE WESTERN
PIEDMONT...WITH MID 50S WEST TO SOME LOWER 50S EAST. PATCHY FOG IS
ALSO POSSIBLE TONIGHT AND SEEMS MOST LIKELY OVER THE SANDHILLS AND
COASTAL PLAIN.
WEDNESDAY AND WEDNESDAY NIGHT...
A STRENGTHENING FRONTAL ZONE STRETCHING FROM THE MID MS RIVER VALLEY
TO THE OHIO VALLEY REGION WILL SINK SLOWLY SOUTHEASTWARD WEDNESDAY
AND BE ORIENTED WEST TO EAST FROM MO TO NORTHERN VA BY WEDNESDAY
NIGHT. THE SURFACE HIGH...WHILE WEAKENING AND SHIFTING FURTHER
OFFSHORE...WILL STILL EXTEND ACROSS NC FOR MOST OF THE DAY. PW WILL
CONTINUE TO CREEP UP TOWARD ON INCH...BUT DESPITE FORECAST SOUNDINGS
SHOWING THE STEEPER MID LEVEL LAPSE RATES LINGERING...MODELS SHOW
ALL CONVECTION WELL NORTH OF THE NC/VA BORDER WHERE A BETTER
PREFRONTAL INSTABILITY AXIS WILL LIE. 850MB TEMPS ARE FORECAST TO
RISE TO AROUND 18C WEDNESDAY AFTERNOON...THOUGH MIXING MAY NOT REACH
QUITE TO 850MB. MIXING TO 925MB INSTEAD YIELDS MOSTLY MID 80S AREA
WIDE. LOWS WEDNESDAY NIGHT AGAIN IN THE LOW TO MID 50S.
&&
.SHORT TERM /THURSDAY AND FRIDAY NIGHT/...
AS OF 240 PM TUESDAY...
MODELS IN ROUGH AGREEMENT IN DEPICTING A WEAK SHORT WAVE MOVING
THROUGH VIRGINIA AND THE CAROLINAS LATE THURSDAY INTO FRIDAY
MORNING. A WEAK FRONT ALONG THE OHIO VALLEY BECOME MORE EAST WEST
ORIENTED AND SLIPS SOUTHWARD IN RESPONSE TO THIS WAVE. WINDS AND
DYNAMICS WITH THIS FRONT CONTINUE QUITE WEAK AND THIS PERIOD MAY
TURN OUT DRY. CURRENTLY BELIEVE THE FRONT WILL REMAIN NORTH IN
VIRGINIA DURING THIS PERIOD. THE BEST RAIN CHANCE IN CENTRAL NORTH
CAROLINA WILL BE LIMITED TO SLIGHT IN THE EXTREME NORTH AND
NORTHWEST... FRIDAY AFTERNOON INTO FRIDAY NIGHT.
THURSDAY STILL LOOKS LIKE THE WARMEST DAY OF THE WORK WEEK WITH LOW
LEVEL THICKNESSES FALLING SLIGHTLY FRIDAY IN RESPONSE TO THE SHORT
WAVE. AFTERNOON HIGH TEMPERATURES 83 TO 88 THURSDAY...82 TO 85
FRIDAY. LOW TEMPERATURES 59 TO 64.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 240 PM TUESDAY...
MODELS CONTINUE TO BE DIVERGENT IN THEIR SOLUTIONS WITH THE LOW
PRESSURE SYSTEM FORECAST TO BE IN SOUTHEAST CANADA SATURDAY MORNING.
THE CANADIAN DEVELOPS A COLD AIR DAMMING (CAD) EVENT DURING THE DAY
SATURDAY... PERSISTING THE CAD TO THE END OF ITS MODEL RUN SUNDAY
EVENING. THE CANADIAN SEEMS TO BE AN OUTLIER IN DEVELOPING A
SIGNIFICANT TROUGH AND CUTTING OFF AN UPPER LOW OVER KENTUCKY
SUNDAY. REJECTING THE CANADIAN MODEL AT THIS TIME. IT DOES APPEAR
THE UPPER SYSTEM WILL RETROGRADE SOUTHWEST TOWARD MICHIGAN DURING
THE WEEKEND. THE GFS AND UKMET HAVE TIMING DIFFERENCES BUT ARE
SIMILAR IN DEPICTING A TROUGH OR CUT OFF LOW EXTENDING TOWARD
MISSISSIPPI OR GEORGIA SATURDAY NIGHT INTO SUNDAY.
SHOULD THE APPROACHING UPPER TROUGH OF THE GFS MODEL COME CLOSE TO
VERIFYING... IT WOULD BE REASONABLE TO HAVE AN INCREASED RAIN CHANCE
SUNDAY AFTERNOON... AND HAVE NUDGED POPS TO ONE IN FOUR. CONTINUING
SLIGHT RAIN CHANCES MOST EVERYWHERE OTHERWISE. CONFIDENCE IN THIS
SCENARIO IS QUITE LOW... AND AWAIT FUTURE MODEL RUNS.
TEMPERATURES WILL CONTINUE TO BE FORECAST WITH AN IDEA TOWARD SOUTH
FLOW AND ENOUGH SUNSHINE DURING THE DAY TO KEEP TEMPERATURES NEAR TO
ABOVE NORMAL IN GENERAL. HIGH TEMPERATURES IN THE LOWER 80S
SATURDAY... OTHERWISE 75 TO NEAR 80. LOW TEMPERATURES 59 TO 65.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 755 PM TUESDAY...
HIGH PRESSURE ONCE OF CANADIAN ORIGIN WILL MAINTAIN VFR CONDITIONS
THROUGH THE 00Z TAF PERIOD...WITH THE EXCEPTION OF IFR-MFVR
VISIBILITY RESTRICTIONS IN RADIATION FOG EARLY WED AT RWI AND KFAY.
ANY SUCH FOG WILL BE VERY PATCHY AND BRIEF...HOWEVER...DUE TO A LACK
OF SUPPORTING LOW LEVEL MOISTURE...AND WIDESPREAD CIRRUS FOR MOST OF
THE NIGHT.
LOOKING AHEAD: GENERALLY VFR CONDITIONS ARE EXPECTED TO CONTINUE
UNTIL AT LEAST FRI...WHEN A FRONT MAY DRIFT INTO CENTRAL NC WITH AN
ASSOCIATED THREAT OF SHOWERS AND STORMS LATE FRI AND MORE SO THROUGH
THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
958 PM EDT TUE SEP 25 2012
.SYNOPSIS...
A WARM FRONT WAS OVER THE LOWER OHIO VALLEY. A COLD FRONT OVER THE
UPPER GREAT LAKES WILL DROP SOUTHEAST ACROSS THE AREA WEDNESDAY.
HIGH PRESSURE WILL MOVE SOUTHEAST OUT OF CANADA CROSSING THE EASTERN
GREAT LAKES BY FRIDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
UPDATE...BACKED POPS OFF TO A SLIGHT CHANCE MOST PLACES FOR THE
OVERNIGHT. SATELLITE AND RADAR TRENDS AGREE WITH HRRR IN KEEPING
MOST OF PRECIP SOUTH OF THE AREA. THE NAM HOWEVER DOES POINT TO A
WETTER SOLUTION SO DID ALLOW FOR THE CHANCE POPS TO CREEP BACK
NORTH TOWARD MORNING JUST IN CASE.
ORIGINAL...ON THE BOUNDARY TONIGHT WHERE THINGS CAN DEVELOP.
THERE IS A ZONE OF DECENT WARM FRONTOGENSIS ACROSS THE MIDWEST
ALONG WITH THE REMNANT MID LEVEL MESO LOW WHICH WILL SLIDE EAST
NORTHEAST THIS EVENING. WE WILL SEE A NICE SURGE IN SURFACE
DEWPOINTS AND DEEPER MOISTURE WITH THE CONTINUED SOUTH TO
SOUTHWEST FLOW. THE LOW LEVEL JET MAXES OUT THIS EVENING AND THEN
BEGINS TO VEER AND SHIFT EAST AND SOUTH. THE COLD FRONT IS WELL TO
THE NORTH AND IS SHALLOW AND I DOUBT IT WILL HAVE MUCH IMPACT
DURING THE OVERNIGHT FORECAST PERIOD. THE JET ALOFT FROM THE UPPER
LAKES IS PROGGED TO DROP SOUTH AND MERGE WITH A JET MAX OVER THE
MIDWEST. THIS WILL INCREASE THE UPPER DIVERGENCE BUT PROBABLY NOT
UNTIL WEDNESDAY MORNING. NO REAL REASON TO THINK THAT IF A NEW
THUNDERSTORM COMPLEX DEVELOPS THAT IT WILL EXPAND TOO FAR NORTH
ALTHOUGH WE WILL LIKELY GET BRUSHED.
THE FORECAST WILL HAVE THE HIGHEST POP ACROSS THE SOUTHERN COUNTIES
FROM AROUND ROUTE 30 SOUTH WITH THE SMALLEST CHANCE AT THE MICHIGAN
OHIO BORDER. WILL MENTION THUNDERSTORMS ANYWHERE...EVEN NORTH...DUE
TO THE ELEVATED CAPE AND THE WARM LAKE ERIE WATER.
FORECAST LOWS WILL BE MOSTLY IN THE LOW 60S...SLIGHTLY HIGHER THAN
MOST OF THE GUIDANCE...AS THE SOUTH WIND AND INCREASING DEWPOINTS
WILL PERSIST. SOME PROTECTED AREAS WHERE THE WIND CAN LIGHTEN UP OR
AREAS THAT ARE RAIN COOLED MAY SNEAK DOWN INTO THE 50S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
THE COLD FRONT WILL SAG SOUTH ACROSS THE FORECAST AREA ON
WEDNESDAY... PROBABLY A LITTLE SLOWER THAN PROGGED IN PREVIOUS DAYS.
IT COULD BE ONE OF THOSE DAYS WHERE THE WIND SHIFTS A LITTLE FASTER
THAN THE ACTUAL FRONT PASSES SINCE PRESSURES WILL BE FALLING TO THE
SOUTH AND RISING TO THE NORTH. ALSO...WITH A SHALLOW FRONT...THERE
COULD BE A FEW SHOWERS WELL NORTH OF THE ACTUAL FRONT. WILL KEEP A
CHANCE OF SHOWERS MOST OF THE DAY. WILL MENTION THUNDER... MAINLY
ACROSS THE SOUTH HALF OF THE FORECAST AREA.
THE MODELS ARE STILL WISHY WASHY ON WAVES OF LOW PRESSURE THAT MAY
BRUSH THE FORECAST AREA FROM THE SOUTH ON THURSDAY AND FRIDAY. GIVEN
THAT WE ARE HAVING TROUBLE GETTING SIGNIFICANT RAIN THIS FAR NORTH
SO FAR... AND WITH A REINFORCING PUSH OF HIGH PRESSURE... WILL KEEP
THE PROBABILITY OF PRECIPITATION LOW ON THURSDAY AND FRIDAY WITH
THE CAVEAT THAT IT IS A LOWER CONFIDENCE FORECAST. HIGHS AND LOWS
WILL BE NEAR NORMAL...THERE IS NOT TOO MUCH COLD ADVECTION.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THERE IS A LOT OF UNCERTAINTY IN THE DETAILS OF THE EXTENDED...BUT
ON THE LARGE SCALE THE WEEKEND SEEMS DOMINATED BY AN EXPANSIVE UPPER
LOW. THIS FEATURE AND THE LIKELY CLOUD COVER ASSOCIATED WITH IT
SHOULD KEEP TEMPS A BIT BELOW NORMAL. NOT SEEING MUCH TO INITIATE
ANY SHOWERS SO WILL MAINTAIN THE DRY FORECAST. THE FLOW WILL
MODERATE SOME FOR EARLY NEXT WEEK...AND BY TAKING AN ENSEMBLE
APPROACH...RETURN TO A ZONAL FLOW WITH MORE SEASONABLE TEMPERATURES.
THIS IS STILL SIMILAR TO PREVIOUS FORECAST FOR THE LONG TERM SO
LITTLE CHANGES MADE.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
A TRICKY FORECAST PERIOD COMING UP WITH SEVERAL FEATURES IMPACTING
THE AREA. SHOWERS WILL CONTINUE TO MOVE EAST INTO PA EARLY TONIGHT
ALLOWING FOR LINGERING MVFR CIGS TO CONTINUE ACROSS THE AREA.
MEANWHILE SOUTHERLY FLOW WILL CONTINUE TO ALLOW FOR INCREASING
MOISTURE INTO THE AREA. TO THE NORTH A COLD FRONT OVER THE NRN
GRTLKS WILL PUSH SOUTH AND CROSS THE AREA DURING WEDNESDAY. MODELS
SUGGESTING MOISTURE WILL BUILD AHEAD OF THE FRONT TO THE NORTH
OVERNIGHT TONIGHT. WITH THAT DEWPOINT ARE EXPECTED TO BEGIN RISING
ACROSS THE AREA...AND WITH A LIGHT S WIND CONTINUING EXPECTING
CIGS TO GRADUALLY FALL LATER TONIGHT ESP AFTER 06Z. MODELS
SUGGESTING ANOTHER PERIOD OF SHRA AND POSSIBLE THUNDER MOVING INTO
CENTRAL OHIO TOWARD 12Z WHICH MAY IMPACT FROM FDY-MFD-CAK. OVERALL
MADE ONLY MINOR CHANGES TO THE IFR PREVIOUSLY FORECAST. EXPECTING
CONDITIONS TO SLOWLY IMPROVE THROUGH THE DAY WED.
.OUTLOOK...LINGERING NON VFR WED NIGHT...OTHERWISE MAINLY VFR
THROUGH THE WEEKEND.
&&
.MARINE...
A TROUGH OF LOW PRESSURE IS ORIENTED FROM LAKE HURON TO LAKE
MICHIGAN THIS AFTERNOON. SOUTHWEST WINDS ON LAKE ERIE WILL DECREASE
INTO WEDNESDAY AS THIS TROUGH SETTLES SOUTH OVER THE LAKE. THE SMALL
CRAFT ADVISORY HAS BEEN ALLOWED TO EXPIRE FOR THE OHIO NEARSHORE
WATERS BUT HAS BEEN EXTENDED UNTIL 10 PM IN NW PA WHERE IT WILL TAKE
A LITTLE LONGER FOR WAVES TO COME DOWN.
WINDS WILL VEER AROUND TO THE NORTH BEHIND THE FRONT LATE WEDNESDAY
WITH WAVES BUILDING TO NEAR 4 FEET AGAIN ALONG THE SOUTH SHORES OF
THE LAKE. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR A BRIEF WINDOW.
HIGH PRESSURE WILL BUILD OVERHEAD ON THURSDAY AND FRIDAY WITH WINDS
DECREASING TO AT OR BELOW 10 KNOTS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LEZ149.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...TK/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...MULLEN
AVIATION...ABE
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS TULSA OK
947 PM CDT TUE SEP 25 2012
...UPDATE...
.DISCUSSION...
CONVECTION ACROSS SOUTHERN KANSAS HAS REMAIN CONFINED TO NEARER
THE FRONTAL ZONE WITH NO CURRENT INDICATION OF WORKING SOUTHWARD.
FURTHER WEST...CONVECTIVE COMPLEX HAS ORGANZIED ACROSS SW OK WITH
SEVERE WINDS BEING REPORTED AT SEVERAL LOCATIONS. THIS COMPLEX MAY
TEND TOWARD A MORE SOUTHEASTWARD DEVELOPMENT...WITH GENERALLY MORE
STABLE AIR CURRENTLY ACROSS SE OK LIMITING THE POTENTIAL THIS FAR
EAST. THE 00Z NAM HAS BACKED OFF ON CONVECTION IN THE AREA
OVERNIGHT...AND IS SUPPORTED BY SEVERAL HRRR RUNS. UPDATED
FORECAST WILL REDUCE OVERNIGHT PRECIP CHANCES ACROSS THE ENTIRE
FORECAST AREA. OTHER ELEMENTS APPEAR ON TRACK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 74 89 68 85 / 40 40 60 60
FSM 65 90 68 87 / 10 10 30 30
MLC 74 92 69 91 / 20 10 10 20
BVO 73 86 64 83 / 50 50 70 60
FYV 66 85 65 82 / 20 40 40 50
BYV 65 84 65 82 / 20 50 40 60
MKO 68 88 67 86 / 30 20 40 40
MIO 69 84 65 83 / 50 60 70 60
F10 71 90 68 86 / 30 20 30 40
HHW 69 89 69 89 / 20 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...07
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1156 PM EDT TUE SEP 25 2012
.SYNOPSIS...
AN APPROACHING FRONTAL BOUNDARY WILL BRING PERIODS OF RAIN DURING
THE OVERNIGHT HOURS THROUGH WEDNESDAY. THE FRONT SHOULD STALL OUT
NEAR THE MASON DIXON LINE DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/...
AREA OF SHOWERS /CONCENTRATED MAINLY ACROSS THE CENTRAL MTNS AND
MIDDLE SUSQ VALLEY AT 0230Z/ WAS MOVING QUICKLY ENE AT NEARLY 35
KTS. THIS AREA OF PRECIP WAS OCCURRING IN RESPONSE TO MDTLY STG
ISENTROPIC LIFT WITHIN THE 300-310K THETA CHANNEL.
88D MOSAIC LOOP...AND THE LATEST RUC AND HRRR INDICATES THAT THE
BULK OF THIS INITIAL AREA OF SHOWERS WILL SCOOT QUICKLY OUT OF OUR
ERN ZONES BY 05Z. A SEVERAL HOUR LULL IN THE RAIN IS LIKELY
AFTERWARD /ESPECIALLY ACROSS THE NORTH/.
THE AXIS OF BEST LLVL ISENTROPIC LIFT AND 850 MB MOISTURE FLUX
/WITHIN THE THERMALLY DIRECT BRANCH OF AN APPROACHING 65KT UPPER
JETLET/ BECOMES FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA FOR THE
WEE HOURS OF WEDNESDAY.
MADE SOME ADJUSTMENTS TO THE POPS AND QPF FOR THE OVERNIGHT HOURS
TO ACCOUNT FOR THE SWD SHIFT TO THE STEADIEST PRECIP.
ADDITIONAL RAINFALL OVERNIGHT WILL VARY FROM 0.20 OR LESS ACROSS THE
SUSQ VALLEY AND NRN MTNS...TO AROUND 0.40 OVER THE LAUREL HIGHLANDS
IN THE SW.
THE CLOUDS AND SWRLY FLOW AHEAD OF THE FRONT WILL KEEP TEMPS MILD
TONIGHT...WITH LOWS AVERAGING 5-10 DEG ABOVE NORMAL.
&&
.SHORT TERM /8 AM WEDNESDAY THROUGH 6 AM WEDNESDAY/...
SHORT RANGE OPERATIONAL MODELS AGREE IN SAGGING THE COLD FRONT
THROUGH THE REGION DURING THE DAY...CLEARING MY SERN ZONES
SOMETIME TOMORROW EVENING. WE MANAGE TO COOK UP SOME MODEST
INSTABILITY AS EVIDENCED WITH FCST CAPES PERHAPS IN THE 500-1000J
RANGE DURING THE AFTERNOON. BUT ABUNDANT CLOUD COVER AND FCST
MEAGER MID LEVEL LAPSE RATES SHOULD LIMIT US TO PERHAPS A FEW
RUMBLES OF THUNDER IN AREAS WHERE SOME SUN MIGHT MANAGE TO BREAK
OUT FOR A TIME.
EXPECT OCCASIONAL SHOWERS/ISOLD THUNDER AHEAD OF THE FRONT. SREF
SUGGEST THE BEST FORCING WILL BE DURING THE MORNING...WANING
DURING THE AFTERNOON AS THE LLJ TURNS MORE WESTERLY AND PUSHES THE
DEEPEST PWATS/MOISTURE FLUX CONVERGENCE OFF TO OUR EAST AND
SOUTHEAST.
HIGHS WILL RANGE FROM THE MID 60S OVER THE NORTH TO NEAR 80 OVER
THE SE. DEWPOINTS WILL REBOUND INTO THE 60S WHICH MAY MAKE IT FEEL
A BIT HUMID.
&&
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
UPPER TROFFING OVER NORTH AMERICA WILL CONTINUE TO DOMINATE OUR
WEATHER THROUGH THE LONG TERM PERIOD. TO WHAT DEGREE AND WITH WHAT
RESULT THE WEATHER WILL BE IS STILL IN QUESTION...ESPECIALLY LATER
IN THE PERIOD.
UPPER LOW MOVING FROM NRN ONTARIO TO NRN QUEBEC WILL PRODUCE BROAD
SW TO WRLY FLOW ACROSS PA THROUGH SATURDAY. AN EMBEDDED SHORTWAVE
TROF WILL BRING A COLD FRONT/SFC LOW TOWARD PA FOR FRIDAY WITH
WIDESPREAD RAIN SHOWERS.
OVER THE WEEKEND...BOTH THE GFS AND ECMWF CLOSE OFF AN UPPER LOW
WITHIN THE LONGWAVE TROF OVER NERN CANADA AND DROP THIS LOW INTO THE
GREAT LAKES/WRN NEW ENGLAND. AT THE SAME TIME...THE LONGWAVE TROF
EXPANDS SWD INTO THE SERN U.S. ...WITH THE EC DEVELOPING A WEAK
CLOSED LOW OVER MS BY TUE. THIS LONGWAVE AMPLIFICATION WILL STALL
THE FRONT THAT IS FORECAST TO MOVE THROUGH PA ON FRIDAY ALONG THE
EASTERN SEABOARD INTO NEXT WEEK. THIS WILL KEEP THE POTENTIAL OF
SHOWERS SOMEWHERE IN CENTRAL PA EACH DAY FROM FRIDAY ONWARD. NO
SIGNIFICANT RAINFALL EVENT LOOKS IN THE OFFING AT THIS POINT...BUT
NEITHER DOES AND EXTENDED PERIOD OF DRY/FAIR WEATHER.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
PERIODS OF RAIN EXPECTED TONIGHT THROUGH WEDNESDAY AHEAD OF AN
APPROACHING FRONTAL BOUNDARY.
CONDITIONS HAVE DETERIORATED TO IFR AT KBFD...BUT REMAIN VFR AT
OTHER TAF SITES AT 04Z. THESE SITES WILL DROP TOO AS THE NIGHT
PROGRESSES. MID-LEVEL LIFT CONTINUES TO INITIATE SHOWERS LATE THIS
EVENING...BUT A SEVERAL HOUR LULL IN THE RAIN IS LIKELY DURING THE
EARLY MORNING HOURS. AS A STRONG WSWLY LOW-LEVEL JET TRANSPORTS
LOW LEVEL MOISTURE INTO CENTRAL PA OVERNIGHT...MVFR/IFR CIGS WILL
SPREAD FROM W TO E. ANOTHER MORE SOLID AREA OF RAIN/SHOWERS
SHOULD DEVELOP LATE TONIGHT...MAINLY ACROSS SOUTHERN HALF.
LOWER CIGS WILL PERSIST INTO MID MORNING ACROSS NW HALF...BUT ALL
TAF SITES SHOULD STUBBORNLY RETURN TO VFR BY 15Z. SHOULD BE SOME
LIGHT SHOWERS AROUND WED MORN...AND THESE WILL BECOME MORE
NUMEROUS BY AFTERNOON AS FRONTAL BOUNDARY APPROACHES. CAPE
MARGINAL FOR ISO TSTMS...BUT DID NOT MENTION IN TAFS AT THIS TIME.
OUTLOOK...
WED...IMPROVING TO VFR THEN FALLING BACK TO MVFR WITH SCATTERED-
NUMEROUS SHOWERS/ISO TSTMS. COLD FROPA/WIND SHIFT DURING THE
AFTERNOON.
THU...MAINLY VFR. SCT SHOWERS POSS MAINLY SOUTH.
FRI...REDUCTIONS POSS WITH SCT SHOWERS.
SAT-SUN...MAINLY VFR. SHOWERS POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LA CORTE/LAMBERT
LONG TERM...LA CORTE/GARTNER
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1033 PM EDT TUE SEP 25 2012
.SYNOPSIS...
AN APPROACHING FRONTAL BOUNDARY WILL BRING PERIODS OF RAIN DURING
THE OVERNIGHT HOURS THROUGH WEDNESDAY. THE FRONT SHOULD STALL OUT
NEAR THE MASON DIXON LINE DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/...
AREA OF SHOWERS /CONCENTRATED MAINLY ACROSS THE CENTRAL MTNS AND
MIDDLE SUSQ VALLEY AT 0230Z/ WAS MOVING QUICKLY ENE AT NEARLY 35
KTS. THIS AREA OF PRECIP WAS OCCURRING IN RESPONSE TO MDTLY STG
ISENTROPIC LIFT WITHIN THE 300-310K THETA CHANNEL.
88D MOSAIC LOOP...AND THE LATEST RUC AND HRRR INDICATES THAT THE
BULK OF THIS INITIAL AREA OF SHOWERS WILL SCOOT QUICKLY OUT OF OUR
ERN ZONES BY 05Z. A SEVERAL HOUR LULL IN THE RAIN IS LIKELY
AFTERWARD /ESPECIALLY ACROSS THE NORTH/.
THE AXIS OF BEST LLVL ISENTROPIC LIFT AND 850 MB MOISTURE FLUX
/WITHIN THE THERMALLY DIRECT BRANCH OF AN APPROACHING 65KT UPPER
JETLET/ BECOMES FOCUSED ACROSS THE SOUTHERN HALF OF THE CWA FOR THE
WEE HOURS OF WEDNESDAY.
MADE SOME ADJUSTMENTS TO THE POPS AND QPF FOR THE OVERNIGHT HOURS
TO ACCOUNT FOR THE SWD SHIFT TO THE STEADIEST PRECIP.
ADDITIONAL RAINFALL OVERNIGHT WILL VARY FROM 0.20 OR LESS ACROSS THE
SUSQ VALLEY AND NRN MTNS...TO AROUND 0.40 OVER THE LAUREL HIGHLANDS
IN THE SW.
THE CLOUDS AND SWRLY FLOW AHEAD OF THE FRONT WILL KEEP TEMPS MILD
TONIGHT...WITH LOWS AVERAGING 5-10 DEG ABOVE NORMAL.
&&
.SHORT TERM /8 AM WEDNESDAY THROUGH 6 AM WEDNESDAY/...
SHORT RANGE OPERATIONAL MODELS AGREE IN SAGGING THE COLD FRONT
THROUGH THE REGION DURING THE DAY...CLEARING MY SERN ZONES
SOMETIME TOMORROW EVENING. WE MANAGE TO COOK UP SOME MODEST
INSTABILITY AS EVIDENCED WITH FCST CAPES PERHAPS IN THE 500-1000J
RANGE DURING THE AFTERNOON. BUT ABUNDANT CLOUD COVER AND FCST
MEAGER MID LEVEL LAPSE RATES SHOULD LIMIT US TO PERHAPS A FEW
RUMBLES OF THUNDER IN AREAS WHERE SOME SUN MIGHT MANAGE TO BREAK
OUT FOR A TIME.
EXPECT OCCASIONAL SHOWERS/ISOLD THUNDER AHEAD OF THE FRONT. SREF
SUGGEST THE BEST FORCING WILL BE DURING THE MORNING...WANING
DURING THE AFTERNOON AS THE LLJ TURNS MORE WESTERLY AND PUSHES THE
DEEPEST PWATS/MOISTURE FLUX CONVERGENCE OFF TO OUR EAST AND
SOUTHEAST.
HIGHS WILL RANGE FROM THE MID 60S OVER THE NORTH TO NEAR 80 OVER
THE SE. DEWPOINTS WILL REBOUND INTO THE 60S WHICH MAY MAKE IT FEEL
A BIT HUMID.
&&
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
UPPER TROFFING OVER NORTH AMERICA WILL CONTINUE TO DOMINATE OUR
WEATHER THROUGH THE LONG TERM PERIOD. TO WHAT DEGREE AND WITH WHAT
RESULT THE WEATHER WILL BE IS STILL IN QUESTION...ESPECIALLY LATER
IN THE PERIOD.
UPPER LOW MOVING FROM NRN ONTARIO TO NRN QUEBEC WILL PRODUCE BROAD
SW TO WRLY FLOW ACROSS PA THROUGH SATURDAY. AN EMBEDDED SHORTWAVE
TROF WILL BRING A COLD FRONT/SFC LOW TOWARD PA FOR FRIDAY WITH
WIDESPREAD RAIN SHOWERS.
OVER THE WEEKEND...BOTH THE GFS AND ECMWF CLOSE OFF AN UPPER LOW
WITHIN THE LONGWAVE TROF OVER NERN CANADA AND DROP THIS LOW INTO THE
GREAT LAKES/WRN NEW ENGLAND. AT THE SAME TIME...THE LONGWAVE TROF
EXPANDS SWD INTO THE SERN U.S. ...WITH THE EC DEVELOPING A WEAK
CLOSED LOW OVER MS BY TUE. THIS LONGWAVE AMPLIFICATION WILL STALL
THE FRONT THAT IS FORECAST TO MOVE THROUGH PA ON FRIDAY ALONG THE
EASTERN SEABOARD INTO NEXT WEEK. THIS WILL KEEP THE POTENTIAL OF
SHOWERS SOMEWHERE IN CENTRAL PA EACH DAY FROM FRIDAY ONWARD. NO
SIGNIFICANT RAINFALL EVENT LOOKS IN THE OFFING AT THIS POINT...BUT
NEITHER DOES AND EXTENDED PERIOD OF DRY/FAIR WEATHER.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
PERIODS OF RAIN EXPECTED TONIGHT THROUGH WEDNESDAY AHEAD OF AN
APPROACHING FRONTAL BOUNDARY.
CONDITIONS REMAIN VFR THIS EVENING ACROSS CENTRAL PA AS MID-LEVEL
LIFT INITIATES AN AREA OF SHOWERS THAT SHOULD QUICKLY SLIDE OUT OF
OUR NE ZONES BY AROUND MIDNIGHT. BUT OVERNIGHT A STRONG WSWLY LOW-
LEVEL JET WILL TRANSPORT LOW LEVEL MOISTURE INTO CENTRAL PA...AND
MVFR/IFR CIGS WILL DEVELOP IN ASSOCIATION WITH IT - INITIALLY AT
KBFD BY 04Z...AND THEN SPREADING SE ACROSS CWA. ANOTHER AREA OF
SHOWERS SHOULD DEVELOP LATER TONIGHT...MAINLY ACROSS SOUTH CENTRAL
MTNS.
LOWER CIGS PERSIST INTO MID MORNING ACROSS NW HALF...BUT ALL TAF
SITES SHOULD STUBBORNLY RETURN TO VFR BY 15Z. SHOULD BE SOME LIGHT
SHOWERS AROUND WED MORN...AND THESE WILL BECOME MORE NUMEROUS BY
AFTERNOON AS FRONTAL BOUNDARY APPROACHES. CAPE MARGINAL FOR ISO
TSTMS...BUT DID NOT MENTION IN TAFS AT THIS TIME.
OUTLOOK...
WED...IMPROVING TO VFR THEN FALLING BACK TO MVFR WITH SCATTERED-
NUMEROUS SHOWERS/ISO TSTMS. COLD FROPA/WIND SHIFT DURING THE
AFTERNOON.
THU...MAINLY VFR. SCT SHOWERS POSS MAINLY SOUTH.
FRI...REDUCTIONS POSS WITH SCT SHOWERS.
SAT-SUN...MAINLY VFR. SHOWERS POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LA CORTE/LAMBERT
LONG TERM...LA CORTE/GARTNER
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
902 PM EDT TUE SEP 25 2012
.SYNOPSIS...
AN APPROACHING FRONTAL BOUNDARY WILL BRING PERIODS OF RAIN TONIGHT
THROUGH WEDNESDAY. THE FRONT SHOULD STALL OUT NEAR THE MASON DIXON
LINE DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AREA OF SHOWERS MOVING QUICKLY ENE ACROSS THE ALLEGHENY PLATEAU
AND INTO THE CENTRAL MOUNTAINS ATTM IN RESPONSE TO ISENTROPIC LIFT
STRENGTHENING WITHIN THE 300-310K THETA CHANNEL.
LATEST RUC AND HRRR INDICATE THAT THE INITIAL AREA OF SHOWERS WILL
SCOOT QUICKLY OUT OF OUR NE ZONES BY AROUND MIDNIGHT. THE PRECIP
WILL BECOME CONCENTRATED ACROSS THE SOUTHERN HALF OF PENNSYLVANIA
LATE TONIGHT...WITHIN THE AXIS OF BEST LLVL ISENTROPIC LIFT AND 850
MB MOISTURE FLUX.
WILL MAKE SOME MINOR MODIFICATIONS TO POPS AND QPF FOR THE OVERNIGHT
HOURS TO ACCOUNT FOR THE SWD MIGRATION TO THE STEADIEST PRECIP.
SREF PLUMES SUPPORT QPF ON THE ORDER OF AROUND .50" ACROSS PORTIONS
OF CENTRAL AND SWRN PENN BY 12Z WED.
THE CLOUDS AND WSW FLOW AHEAD OF THE FRONT WILL KEEP TEMPS MILD
TONIGHT...WITH LOWS AVERAGING 5-10 DEG ABOVE NORMAL.
&&
.SHORT TERM /6 AM WEDNESDAY THROUGH 6 AM WEDNESDAY/...
SHORT RANGE OPERATIONAL MODELS AGREE IN SAGGING THE COLD FRONT
THROUGH THE REGION DURING THE DAY...CLEARING MY SERN ZONES
SOMETIME TOMORROW EVENING. WE MANAGE TO COOK UP SOME MODEST
INSTABILITY AS EVIDENCED WITH FCST CAPES PERHAPS IN THE 500-1000J
RANGE DURING THE AFTERNOON. BUT ABUNDANT CLOUD COVER AND FCST
MEAGER MID LEVEL LAPSE RATES SHOULD LIMIT US TO PERHAPS A FEW
RUMBLES OF THUNDER IN AREAS WHERE SOME SUN MIGHT MANAGE TO BREAK
OUT FOR A TIME.
EXPECT OCCASIONAL SHOWERS/ISOLD THUNDER AHEAD OF THE FRONT. SREF
SUGGEST THE BEST FORCING WILL BE DURING THE MORNING...WANING
DURING THE AFTERNOON AS THE LLJ TURNS MORE WESTERLY AND PUSHES THE
DEEPEST PWATS/MOISTURE FLUX CONVERGENCE OFF TO OUR EAST AND
SOUTHEAST.
HIGHS WILL RANGE FROM THE MID 60S OVER THE NORTH TO NEAR 80 OVER
THE SE. DEWPOINTS WILL REBOUND INTO THE 60S WHICH MAY MAKE IT FEEL
A BIT HUMID.
&&
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
UPPER TROFFING OVER NORTH AMERICA WILL CONTINUE TO DOMINATE OUR
WEATHER THROUGH THE LONG TERM PERIOD. TO WHAT DEGREE AND WITH WHAT
RESULT THE WEATHER WILL BE IS STILL IN QUESTION...ESPECIALLY LATER
IN THE PERIOD.
UPPER LOW MOVING FROM NRN ONTARIO TO NRN QUEBEC WILL PRODUCE BROAD
SW TO WRLY FLOW ACROSS PA THROUGH SATURDAY. AN EMBEDDED SHORTWAVE
TROF WILL BRING A COLD FRONT/SFC LOW TOWARD PA FOR FRIDAY WITH
WIDESPREAD RAIN SHOWERS.
OVER THE WEEKEND...BOTH THE GFS AND ECMWF CLOSE OFF AN UPPER LOW
WITHIN THE LONGWAVE TROF OVER NERN CANADA AND DROP THIS LOW INTO THE
GREAT LAKES/WRN NEW ENGLAND. AT THE SAME TIME...THE LONGWAVE TROF
EXPANDS SWD INTO THE SERN U.S. ...WITH THE EC DEVELOPING A WEAK
CLOSED LOW OVER MS BY TUE. THIS LONGWAVE AMPLIFICATION WILL STALL
THE FRONT THAT IS FORECAST TO MOVE THROUGH PA ON FRIDAY ALONG THE
EASTERN SEABOARD INTO NEXT WEEK. THIS WILL KEEP THE POTENTIAL OF
SHOWERS SOMEWHERE IN CENTRAL PA EACH DAY FROM FRIDAY ONWARD. NO
SIGNIFICANT RAINFALL EVENT LOOKS IN THE OFFING AT THIS POINT...BUT
NEITHER DOES AND EXTENDED PERIOD OF DRY/FAIR WEATHER.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
PERIODS OF RAIN EXPECTED TONIGHT THROUGH WEDNESDAY AHEAD OF AN
APPROACHING FRONTAL BOUNDARY.
CONDITIONS REMAIN VFR THIS EVENING ACROSS CENTRAL PA AS MID-LEVEL
LIFT INITIATES AN AREA OF SHOWERS THAT SHOULD QUICKLY SLIDE OUT OF
OUR NE ZONES BY AROUND MIDNIGHT. BUT OVERNIGHT A STRONG WSWLY LOW-
LEVEL JET WILL TRANSPORT LOW LEVEL MOISTURE INTO CENTRAL PA...AND
MVFR/IFR CIGS WILL DEVELOP IN ASSOCIATION WITH IT - INITIALLY AT
KBFD BY 04Z...AND THEN SPREADING SE ACROSS CWA. ANOTHER AREA OF
SHOWERS SHOULD DEVELOP LATER TONIGHT...MAINLY ACROSS SOUTH CENTRAL
MTNS.
LOWER CIGS PERSIST INTO MID MORNING ACROSS NW HALF...BUT ALL TAF
SITES SHOULD STUBBORNLY RETURN TO VFR BY 15Z. SHOULD BE SOME LIGHT
SHOWERS AROUND WED MORN...AND THESE WILL BECOME MORE NUMEROUS BY
AFTERNOON AS FRONTAL BOUNDARY APPROACHES. CAPE MARGINAL FOR ISO
TSTMS...BUT DID NOT MENTION IN TAFS AT THIS TIME.
OUTLOOK...
WED...IMPROVING TO VFR THEN FALLING BACK TO MVFR WITH SCATTERED-
NUMEROUS SHOWERS/ISO TSTMS. COLD FROPA/WIND SHIFT DURING THE
AFTERNOON.
THU...MAINLY VFR. SCT SHOWERS POSS MAINLY SOUTH.
FRI...REDUCTIONS POSS WITH SCT SHOWERS.
SAT-SUN...MAINLY VFR. SHOWERS POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LA CORTE
LONG TERM...LA CORTE/GARTNER
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
614 PM CDT TUE SEP 25 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
HIGH PRESSURE WAS BUILDING INTO WISCONSIN THIS AFTERNOON OUT OF
CANADA...RESULTING IN QUIET WEATHER. JUST A FEW FAIR WEATHER CU
DEVELOPED OVER NORTHERN WISCONSIN AND ALONG WITH LAKESHORE. THIS
AREA OF HIGH PRESSURE WILL CONTINUE TO PUSH INTO NORTHEAST WI
DURING THE SHORT TERM...WITH THE MAIN FORECAST CHALLENGES BEING
CLOUDS AND TEMPERATURES.
A 500MB SHORTWAVE WILL PASS OVER LAKE SUPERIOR OVERNIGHT INTO
WEDNESDAY...BRUSHING NORTHERN WISCONSIN AS IT DOES SO. WITH SFC
HIGH PRESSURE MOVING OVER WISCONSIN...DRY AIR AND A LACK OF
FORCING WILL PREVENT ANY PRECIP SO KEPT DRY FORECAST GOING.
MODELS HAVE BEEN STRUGGLING WITH CLOUDS WITH THIS FEATURE AS IT
MOVES THROUGH. CURRENT SAT ELITE AND RAP MODEL ANALYSIS SHOWS THAT
MOST OF THE MOISTURE ASSOCIATED WITH THE CLOUDS CURRENTLY IN
NORTHEAST MINNESOTA NEAR THE DIGGING SHORTWAVE IS CONFINED TO 925
AND 850MB...SO USED THIS INFORMATION FOR CLOUD FORECAST FOR
TONIGHT AND WEDNESDAY. CU FROM THIS AFTERNOON WILL DISSIPATE WITH
THE SUNSET OVER NORTHERN WI...BUT WILL LINGER NEAR THE LAKESHORE
WITH THE CONTINUED NE FLOW. THE NEXT AREA OF CLOUDS WILL MOVE INTO
NORTHERN WISCONSIN AFTER 06Z TONIGHT. CLOUDS WILL BE LIMITED AT
FIRST...BUT THEN SHOULD INCREASE IN COVERAGE TOMORROW...ESPECIALLY
DURING THE AFTERNOON...AS SUN AIDS IN CU DEVELOPMENT AND
SUFFICIENT 850MB MOISTURE OVERSPREADS THE AREA. NORTHERN WISCONSIN
SHOULD SEE THE MOST CLOUDS AS IT IS NEAREST TO THE PASSING
SHORTWAVE...WITH A MIX OF SUN AND CLOUDS ELSEWHERE.
DIDNT CHANGE MUCH TEMPERATURE-WISE FROM PREVIOUS FORECAST AS
NORTHWEST FLOW WILL KEEP THINGS COOLER THAN NORMAL ON WEDNESDAY.
WIDESPREAD FROST IS AGAIN EXPECTED IN NORTHERN WI WHERE GROWING
SEASON HAS ENDED. PATCHY FROST IS POSSIBLE IN CENTRAL WISCONSIN
TONIGHT...HOWEVER THINK TEMPS WILL BE SLIGHTLY TOO WARM FOR
WIDESPREAD FROST DEVELOPMENT.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY.
QUIET WEATHER PATTERN EXPECTED THROUGH THE PERIOD. MODELS CONTINUE
TO STRUGGLE WITH CLOSED UPPER LOW ACROSS THE EASTERN UNITED STATES
OVER THE WEEKEND. LATEST GFS IS FURTHER WEST THAN THE CANADIAN AND
THE 12Z LOW RES ECMWF IS FURTHER WEST THAN BOTH THE CANADIAN/GFS.
DID NOT RECEIVE THE 12Z HIGH ECMWF...THEREFORE WILL CONTINUE WITH A
DRY AND CLEAR TO PARTLY CLOUDY FORECAST FOR THE WEEKEND. IF ECMWF
TREND IS CORRECT...LATER SHIFT MAY NEED TO ADD MORE CLOUDS AND
MAYBE A SMALL CHANCE OF SHOWER OVER THE WEEKEND WITH ENERGY
PIVOTING AROUND THE UPPER LOW.
OTHERWISE...IT WILL BE SEASONABLE WITH LOWS IN THE 30S TO LOWER
TO MIDDLE 40S AND HIGHS IN THE 60S TO AROUND 70. DID LOWER MIN
TEMPERATURES A FEW DEGREES EACH NIGHT THROUGH THE WEEKEND...
ESPECIALLY IN THE TYPICAL COLD SPOTS NORTH AND WEST OF GREEN BAY
AND THE FOX CITES. ALSO RAISED MAX TEMPERATURES A FEW DEGREES ON
FRIDAY BASED ON 925MB TEMPERATURES AND EXPECTED DRY AIR MASS IN
PLACE.
&&
.AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH WEDNESDAY AFTERNOON.
SOME FAIR WEATHER CUMULUS CLOUDS WILL DEVELOP WEDNESDAY MORNING BETWEEN
FOUR TO FIVE THOUSAND FEET. THERE COULD BE A PERIOD OF A BROKEN DECK
ACROSS THE NORTH AND NORTHEAST. SKIES WILL BECOME MOSTLY CLEAR LATE
WEDNESDAY AFTERNOON OR EARLY WEDNESDAY EVENING. LIGHT NORTHEAST OR
EAST WINDS ACROSS NORTHEAST WISCONSIN THIS EVENING WILL BACK TO THE
NORTHWEST OVERNIGHT. THE REMAINDER OF THE AREA WILL SEE LIGHT NORTH
TO NORTHWEST WINDS. NORTHWEST TO NORTH WINDS OF 5 TO 10 KNOTS CAN
BE EXPECTED ON WEDNESDAY...EXCEPT ACROSS NORTHEAST WISCONSIN WHERE
WINDS WILL VEER TO THE NORTHEAST DURING THE AFTERNOON.
ECKBERG
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
242 AM EDT WED SEP 26 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL CROSS THE AREA
OVERNIGHT...FOLLOWED BY A COLD FRONT APPROACHING ON WEDNESDAY AND
MOVING ACROSS THE AREA WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT ON THURSDAY. THE FRONTAL BOUNDARY WILL THEN
SLOWLY RETURN NORTHWARD AS A WARM FRONT FRIDAY...WITH SEVERAL
WAVES OF LOW PRESSURE TRAVELING ALONG IT POTENTIALLY IMPACTING THE
AREA INTO THE BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
500 HPA SHORTWAVE BACK OVER PA...WILL PUSH THROUGH THE AREA
OVERNIGHT...THIS COUPLED WITH SOME WEAK ISENTROPIC LIFT WILL
PRODUCE SOME SPOTTY LIGHT RAIN...MAINLY OVER THE NW 1/2 OF THE
TRI-STATE.
LATEST HRRR BRINGS THE CORE OF THE LIGHT RAIN CURRENTLY OVER
CENTRAL PA TO THE NW OF THE CWA AND BOTH THE 00Z NAM AND GFS
SUGGEST THIS AREA WEAKENS AS WELL. POPS UPDATED TO BLEND OF
HRRR/SREF/NAM 3-HOURLY POPS AND LIKELY POPS HAVE BEEN REMOVED AS A
RESULT.
LOW LEVEL WARM ADVECTION WILL ALLOW FOR TEMPERATURES TO FALL OFF
ONLY A FEW DEGREES FROM CURRENT LEVELS...SO EXPECT LOWS 5 DEGREES
OR SO ABOVE NORMAL.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
WARM ADVECTION/ISENTROPIC LIFT WEAKENS ON WEDNESDAY AND THUS POP
CHANCES LOWER. SREF AND GEFS ALONG WITH OPERATION 12Z RUNS SUPPORT
THIS IDEA. IN FACT...HAVE MADE IT DRY IN THE SOUTHERN PORTION OF THE
CWA.
USED A MIX OF THE MOS PRODUCTS FOR MAX TEMPS AS THERE IS
UNCERTAINTY WITH THE AMOUNT OF DAYTIME HEATING. EVEN IF THE NAM
NUMBERS DO VERIFY...STILL BELIEVE THAT INSTABILITY IS LIMITED
ENOUGH TO KEEP ANY CONVECTIVE A BAY FOR THE AFTERNOON.
COLD FRONT IS TIMED IN FOR THE EVENING. AGAIN...INSTABILITY IS
LIMITED...BUT ENOUGH SKINNY CAPE TO INCLUDE ISOLATED TSTM.
BASED ON FAIRLY GOOD CONSENSUS OF THE NWP SYSTEMS...APPEARS THAT
BULK OF SHOWER ACTIVITY IS LATE EVENING TO AROUND MIDNIGHT.
AGAIN...OVERALL ABOUTS SHOULD BE LIGHT.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN
BEACHES ON WEDNESDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A COLD FRONT WILL BE SOUTHEAST OF THE REGION THURSDAY MORNING WITH
HIGH PRESSURE BRIEFLY BUILDING INTO THE REGION. EXPECTING DRY
CONDITIONS ON THURSDAY WITH MOSTLY SUNNY CONDITIONS. TEMPERATURES
WILL REMAIN COOL ON THURSDAY WITH HIGHS ONLY REACHING THE UPPER
60S AND LOWER 70S.
THE FRONTAL BOUNDARY SOUTH OF THE REGION WILL RETURN NORTHWARD AS A
WARM FRONT ON FRIDAY. MODELS STILL HAVE SOME DIFFERENCES TO THE
EXACT TIMING AND PLACEMENT OF THIS BOUNDARY. THE EXACT POSITION OF
THE FRONT COULD PLAY A MAJOR ROLE IN TEMPERATURES AND WEATHER TYPE
FRIDAY THROUGH MONDAY. THE 25/00Z ECMWF KEEPS THE BOUNDARY THROUGH
OR WEST OF THE CWA TIL SUN NIGHT...WHEREAS THE 25/12Z GFS CONTINUES
TO KEEP THE BOUNDARY OFFSHORE. IN ADDITION...A LARGE UPPER LEVEL LOW
WILL BUILD OVER THE GREAT LAKES REGION. THIS WILL RESULT IN SEVERAL
WAVES OF LOW PRESSURE TO TRAVEL ALONG THIS BOUNDARY...BRINGING
PERIODS OF RAIN TO THE REGION. WILL CARRY CHANCE POPS THROUGH THE
EXTENDED FOR NOW WITH TIMING AND PLACEMENT UNCERTAINTY. RIGHT
NOW...IT APPEARS THE BEST CHANCES OF PRECIPITATION APPEAR TO BE
SATURDAY NIGHT INTO SUNDAY...HOWEVER THIS IS A LOW CONFIDENCE
FORECAST.
THIS FRONTAL BOUNDARY FINALLY GETS PUSHED OFF TO THE WEST AS THE LOW
LIFTS NORTH PUSHING THE FRONT EAST OF THE REGION DURING THE DAY
MONDAY...WITH SOME DRIER AIR WORKING INTO THE REGION ON TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AN UPPER LEVEL DISTURBANCE WILL MOVE THROUGH THE AREA OVERNIGHT. A
COLD FRONT WILL APPROACH FROM THE NW ON WEDNESDAY AND MOVE THROUGH
DURING THE EVENING HOURS.
MAINLY VFR CONDS THROUGH THE PERIOD. CIGS/VSBY MAY BRIEFLY DROP
BETWEEN 2-3K FT AND 5SM RESPECTIVELY IN ANY SHOWERS...BUT HIGHEST
PROBABILITY IS AT KSWF AND MAINLY WITH THE FRONTAL PASSAGE THIS
EVENING. IF WINDS DECOUPLE TONIGHT AT KSWF...3-5SM VSBY IS
POSSIBLE. LOW CONFIDENCE AS DRIER AIR BEHIND THE FRONT WOULD BE
WORKING IN AT THE SAME TIME.
A MODERATE S/SW FLOW WILL CONTINUE THROUGH WED. OCNL GUSTS
UP TO 20 KT ARE POSSIBLE THROUGH THE REMAINDER OF THE
NIGHT...MAINLY AT COASTAL TERMINALS. SOME UNCERTAINTY WHEN GUSTS
RETURN DURING THE MORNING AND HOW HIGH THEY WILL BE. THEY COULD BE
1-2 HOURS EARLIER THAN FORECAST...ESPECIALLY AT EASTERN TERMINALS
WHERE WINDS OFF THE DECK WILL BE HIGHER. GUSTS COULD ALSO BE A FEW
KT HIGHER BETWEEN 17Z AND 21Z AND MAY LINGER A FEW HOURS LONGER
THAN CURRENTLY FORECAST.
FIRST AREA OF SHOWERS IS ONLY PRODUCING MEASURABLE RAIN AT KSWF
EARLY THIS MORNING. REMAINING TERMINALS SHOULD ONLY SEE LIGHT RAIN
OR SPRINKLES WHICH SHOULD NOT HAVE AN IMPACT ON RUNWAY CONDS. ONCE
THIS AREA LIFTS N...SHOWER ACTIVITY WILL BECOME WIDELY SCT TO NIL
UNTIL THE COLD FRONT APPROACHES LATE THIS AFTN/EARLY EVE. SCT TO
NUMEROUS SHOWERS AND POSSIBLY AN ISOLD RUMBLE OF THUNDER WILL
PRECEDE THE FROPA WHICH MOVES THROUGH THE TERMINALS BETWEEN 02Z TO
06Z THU RESULTING IN A WIND SHIFT TO THE W/NW AND DECREASING
SPEEDS.
WEAK INSTABILITY AND STRONG WINDS ALOFT COULD PRODUCE SOME GUSTY
WINDS WITH THE SHOWERS/ISOLD TSTM ALONG AND AHEAD OF COLD FRONT.
POSSIBLE GUSTS UP TO 30 KT.
OUTLOOK FOR 06Z THURSDAY-SUNDAY...
.WED NIGHT-THU...VFR.
.FRI-SUN...MVFR OR LOWER POSSIBLE IN RAIN.
&&
.MARINE...
MINOR CHANGES TO THE GRIDS MADE TO REFLECT LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. MAIN CHANGE WAS TO SLOW DOWN TIMING FOR
ONSET OF LIGHT RAIN OVERNIGHT. REMAINDER OF FORECAST APPEARS ON
TRACK...WITH ON AND OFF MARGINAL SCA WIND GUSTS OVER ALL BUT NY
HARBOR OVERNIGHT.
SCA CONDITIONS ON ALL WATERS EXCEPT NY HARBOR THROUGH WED
AFTERNOON. SEAS GRADUALLY BUILD ON THE OCEAN AS A RESULT OF THE SW
FLOW. WINDS AND OCEAN SEAS WILL REMAIN AT OR ABOVE SCA LEVELS ON
WED.
SCA CONDITIONS SUBSIDE WED NIGHT. CONDITIONS LIKELY REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS THURSDAY THROUGH SATURDAY...AND
REDEVELOP ON SUNDAY ACROSS THE OCEAN WATERS. THERE IS THE
POTENTIAL THAT PROLONGED EASTERLY FLOW COULD LEAD TO SCA
CONDITIONS STARTING SOONER THAN FORECAST. SEAS ARE EXPECTED TO
SUBSIDE DURING THE DAY MONDAY.
&&
.HYDROLOGY...
LESS THAN 1/4 INCH OF BASIN AVERAGE QPF IS EXPECTED THROUGH WED NIGHT.
THERE IS THE POTENTIAL FOR WIDESPREAD PRECIPITATION FRIDAY THROUGH
MONDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-340-345-350-353-355.
&&
$$
SYNOPSIS...BC/MALOIT/JST
NEAR TERM...JC/MALOIT/JST
SHORT TERM...JST
LONG TERM...BC
AVIATION...
MARINE...BC/JC/MALOIT/JST
HYDROLOGY...BC/JST
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1241 AM EDT WED SEP 26 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL CROSS THE AREA
OVERNIGHT...FOLLOWED BY A COLD FRONT APPROACHING ON WEDNESDAY AND
MOVING ACROSS THE AREA WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT ON THURSDAY. THE FRONTAL BOUNDARY WILL THEN
SLOWLY RETURN NORTHWARD AS A WARM FRONT FRIDAY...WITH SEVERAL
WAVES OF LOW PRESSURE TRAVELING ALONG IT POTENTIALLY IMPACTING THE
AREA INTO THE BEGINNING OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
500 HPA SHORTWAVE BACK OVER PA...WILL PUSH THROUGH THE AREA
OVERNIGHT...THIS COUPLED WITH SOME WEAK ISENTROPIC LIFT WILL
PRODUCE SOME SPOTTY LIGHT RAIN...MAINLY OVER THE NW 1/2 OF THE
TRI-STATE.
LATEST HRRR BRINGS THE CORE OF THE LIGHT RAIN CURRENTLY OVER
CENTRAL PA TO THE NW OF THE CWA AND BOTH THE 00Z NAM AND GFS
SUGGEST THIS AREA WEAKENS AS WELL. POPS UPDATED TO BLEND OF
HRRR/SREF/NAM 3-HOURLY POPS AND LIKELY POPS HAVE BEEN REMOVED AS A
RESULT.
LOW LEVEL WARM ADVECTION WILL ALLOW FOR TEMPERATURES TO FALL OFF
ONLY A FEW DEGREES FROM CURRENT LEVELS...SO EXPECT LOWS 5 DEGREES
OR SO ABOVE NORMAL.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
WARM ADVECTION/ISENTROPIC LIFT WEAKENS ON WEDNESDAY AND THUS POP
CHANCES LOWER. SREF AND GEFS ALONG WITH OPERATION 12Z RUNS SUPPORT
THIS IDEA. IN FACT...HAVE MADE IT DRY IN THE SOUTHERN PORTION OF THE
CWA.
USED A MIX OF THE MOS PRODUCTS FOR MAX TEMPS AS THERE IS
UNCERTAINTY WITH THE AMOUNT OF DAYTIME HEATING. EVEN IF THE NAM
NUMBERS DO VERIFY...STILL BELIEVE THAT INSTABILITY IS LIMITED
ENOUGH TO KEEP ANY CONVECTIVE A BAY FOR THE AFTERNOON.
COLD FRONT IS TIMED IN FOR THE EVENING. AGAIN...INSTABILITY IS
LIMITED...BUT ENOUGH SKINNY CAPE TO INCLUDE ISOLATED TSTM.
BASED ON FAIRLY GOOD CONSENSUS OF THE NWP SYSTEMS...APPEARS THAT
BULK OF SHOWER ACTIVITY IS LATE EVENING TO AROUND MIDNIGHT.
AGAIN...OVERALL ABOUTS SHOULD BE LIGHT.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC OCEAN
BEACHES ON WEDNESDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A COLD FRONT WILL BE SOUTHEAST OF THE REGION THURSDAY MORNING WITH
HIGH PRESSURE BRIEFLY BUILDING INTO THE REGION. EXPECTING DRY
CONDITIONS ON THURSDAY WITH MOSTLY SUNNY CONDITIONS. TEMPERATURES
WILL REMAIN COOL ON THURSDAY WITH HIGHS ONLY REACHING THE UPPER
60S AND LOWER 70S.
THE FRONTAL BOUNDARY SOUTH OF THE REGION WILL RETURN NORTHWARD AS A
WARM FRONT ON FRIDAY. MODELS STILL HAVE SOME DIFFERENCES TO THE
EXACT TIMING AND PLACEMENT OF THIS BOUNDARY. THE EXACT POSITION OF
THE FRONT COULD PLAY A MAJOR ROLE IN TEMPERATURES AND WEATHER TYPE
FRIDAY THROUGH MONDAY. THE 25/00Z ECMWF KEEPS THE BOUNDARY THROUGH
OR WEST OF THE CWA TIL SUN NIGHT...WHEREAS THE 25/12Z GFS CONTINUES
TO KEEP THE BOUNDARY OFFSHORE. IN ADDITION...A LARGE UPPER LEVEL LOW
WILL BUILD OVER THE GREAT LAKES REGION. THIS WILL RESULT IN SEVERAL
WAVES OF LOW PRESSURE TO TRAVEL ALONG THIS BOUNDARY...BRINGING
PERIODS OF RAIN TO THE REGION. WILL CARRY CHANCE POPS THROUGH THE
EXTENDED FOR NOW WITH TIMING AND PLACEMENT UNCERTAINTY. RIGHT
NOW...IT APPEARS THE BEST CHANCES OF PRECIPITATION APPEAR TO BE
SATURDAY NIGHT INTO SUNDAY...HOWEVER THIS IS A LOW CONFIDENCE
FORECAST.
THIS FRONTAL BOUNDARY FINALLY GETS PUSHED OFF TO THE WEST AS THE LOW
LIFTS NORTH PUSHING THE FRONT EAST OF THE REGION DURING THE DAY
MONDAY...WITH SOME DRIER AIR WORKING INTO THE REGION ON TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A MODERATE S/SW FLOW WILL CONTINUE FOR ANOTHER 24H WITH GUSTS TO
AROUND 20 KT RETURNING LATE MORNING/EARLY AFT WED. COLD FRONT MOVES
THROUGH TERMINALS 02Z TO 06Z THU.
MID LEVEL DECK ADVANCES IN FROM THE SW OVERNIGHT. LOW END VFR
CIGS IN THE MORNING WITH POSSIBILITY OF MVFR CIGS IN ANY SHOWERS.
THE BEST CHANCE FOR THIS WILL BE ACROSS THE LOWER HUDSON VALLEY
TERMINALS. CIGS IMPROVE LATE MORNING AND THEN BEGIN TO LOWER
TOWARD 00Z WITH THE APPROACH OF A COLD FRONT.
WEAK INSTABILITY AND STRONG WINDS ALOFT COULD PRODUCE SOME GUSTY
WINDS WITH SHOWERS OR EVEN AN ISOLATED THUNDERSTORM TOMORROW
EVENING ALONG AND AHEAD OF COLD FRONT. POSSIBLE GUSTS UP TO 30 KT.
OUTLOOK FOR 00Z WEDNESDAY-SUNDAY...
.WED NIGHT...MVFR POSSIBLE IN ANY HEAVIER SHRA/ISOLATED TSRA...WITH
GUSTS UP TO 30 KT.
.THU...VFR.
.FRI-SUN...MVFR OR LOWER POSSIBLE IN RAIN.
&&
.MARINE...
MINOR CHANGES TO THE GRIDS MADE TO REFLECT LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. MAIN CHANGE WAS TO SLOW DOWN TIMING FOR
ONSET OF LIGHT RAIN OVERNIGHT. REMAINDER OF FORECAST APPEARS ON
TRACK...WITH ON AND OFF MARGINAL SCA WIND GUSTS OVER ALL BUT NY
HARBOR OVERNIGHT.
SCA CONDITIONS ON ALL WATERS EXCEPT NY HARBOR THROUGH WED
AFTERNOON. SEAS GRADUALLY BUILD ON THE OCEAN AS A RESULT OF THE SW
FLOW. WINDS AND OCEAN SEAS WILL REMAIN AT OR ABOVE SCA LEVELS ON
WED.
SCA CONDITIONS SUBSIDE WED NIGHT. CONDITIONS LIKELY REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS THURSDAY THROUGH SATURDAY...AND
REDEVELOP ON SUNDAY ACROSS THE OCEAN WATERS. THERE IS THE
POTENTIAL THAT PROLONGED EASTERLY FLOW COULD LEAD TO SCA
CONDITIONS STARTING SOONER THAN FORECAST. SEAS ARE EXPECTED TO
SUBSIDE DURING THE DAY MONDAY.
&&
.HYDROLOGY...
LESS THAN 1/4 INCH OF BASIN AVERAGE QPF IS EXPECTED THROUGH WED NIGHT.
THERE IS THE POTENTIAL FOR WIDESPREAD PRECIPITATION FRIDAY THROUGH
MONDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-340-345-350-353-355.
&&
$$
SYNOPSIS...MALOIT/JST/BC
NEAR TERM...MALOIT
SHORT TERM...JST
LONG TERM...BC
AVIATION...DW
MARINE...MALOIT/JC/JST/BC
HYDROLOGY...JST/BC
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
335 AM EDT WED SEP 26 2012
.DISCUSSION...
CURRENT...
STUBBORN BAND OF MOISTURE AND MID LVL VORTICITY CONTS TO SUPPORT
ISOLD SHRAS OVER THE ATLC N OF THE CAPE THAT ARE PUSHING ONSHORE.
HOWEVER...RADAR TREND SHOWS THESE DECREASING OVER THE PAST FEW HRS
AS THE MOISTURE/VORTICITY HAVE MERGED WITH THE REMNANT FRONTAL
MOISTURE OVER S FL. THE 00Z SOUNDINGS CONTINUED TO SHOW A SLUG OF
DRY AIR OVER CENTRAL FL PWAT VALUES AT KTBW ARND 0.9"...INCREASING
TO 1.3" AT KJAX AND TO 2.1" AT KMFL.
LATEST RAP ANALYSIS SHOWS A LARGE H100-H70 RIDGE CENTERED JUST OFF
THE ERN SEABOARD WITH ITS AXIS TRAILING BACK ACRS THE DEEP SOUTH TO
THE RIO GRANDE VALLEY. AT THE MID LVLS...HOWEVER...THE AXIS HAS A
MORE NW/SE ORIENTATION...RESULTING IN SERLY FLOW THRU THE H85-H50
LYR. A SMALL TROF AXIS ALSO NOTED IN THIS LAYER ACRS CNTRL FL WITH
MEAN RH VALUES INCREASING FROM AOB 30PCT AHEAD OF ITS AXIS...TO AOA
85PCT BEHIND IT. MID LVL LAPSE RATES HAVE STEEPENED A LITTLE IN THE
PAST 24HRS AS WELL...NOW UP TO 5.5-6.5C/KM.
TODAY-TONIGHT...
THE POSITION OF THE LOW LVL RIDGE WILL GENERATE A STEADY E/NE FLOW
ACRS CENTRAL FL...WHILE THE FLOW ALOFT PUSHES DEEP MOISTURE UP FROM
THE FL STRAITS. THE DENSE MID/UPR LVL HIGH CLOUDS THAT HAVE
BLANKETED THE REGION FOR THE PAST FEW DAYS WILL THIN OUT AS THE
H30-H20 JET STREAK THAT HAS SUPPORTED THEM PULLS INTO THE
ATLC...LEAVING PCLDY SKIES ACRS THE NRN CWA. WHILE THIS AREA WILL
NOT SEE THE DEEPEST MOISTURE RETURN...THE GREATER SFC HEATING
POTENTIAL WILL MAKE THEM BETTER CANDIDATES FOR SCT TSRAS. INCREASING
CLOUDS OVER THE SRN CWA WILL CONTINUE TO HAMPER SFC HEATING...WILL
KEEP CHC SHRAS/SLGT CHC TSRAS IN FROM OSCEOLA/SRN BREVARD SWD.
SHRAS MAY LINGER INTO THE EARLY EVNG...BUT SHOULD END OVER THE
INTERIOR BY MIDNIGHT WITH THE LOSS OF DAYTIME HEATING. WILL NEED TO
KEEP 20/30 POPS IN FOR THE COASTAL ZONES AS ERLY FLOW THRU THE
H100-H70 LYR WILL SET THE STAGE FOR NOCTURNAL COASTAL CONVERGENCE
SHRAS.
ONSHORE FLOW WILL KEEP COASTAL TEMPS IN THE M80S...MAX TEMPS
SLIGHTLY WARMER ACRS THE INTERIOR CWA...ESPECIALLY ALONG AN N OF THE
I-4 CORRIDOR WITH THE THINNING OF THE MID/UPR LVL CLOUDS...READINGS
IN THE U80S/L90S. MIN TEMPS IN THE L/M70S.
THU-FRI...
SURFACE RIDGE AXIS REMAINS OVER THE SOUTHEAST U.S. AND WINDS STAY
OUT OF THE EAST. PRECIPITABLE WATER VALUES RANGE FROM AROUND AN INCH
AND A HALF OVER THE NORTHERN END OF THE FORECAST AREA TO ABOUT TWO
INCHES OVER THE SOUTHERN SECTIONS. MODEL RAIN CHANCES OF 30 NORTH TO
40 SOUTH LOOK REASONABLE GIVEN BETTER MOISTURE OVER THE SOUTHERN
AREA.
SAT-TUE...
MOISTURE ASSOCIATED WITH A SLOW MOVING NEAR ZONAL UPPER LEVEL FLOW
WORKS IT WAY FROM THE SOUTHEAST STATES INTO THE NORTHERN HALF
FLORIDA SUNDAY AND SLOWLY DROPS DOWN THE PENINSULA AND INTO CENTRAL
FLORIDA BY TUESDAY. MID LEVEL SUPPORT IS NOT STRONG BUT IS OFFSET BY
PRECIPITABLE WATER VALUES OVER TWO INCHES SUNDAY THROUGH TUESDAY
THUS 40 AND 50 POP FOR SATURDAY THROUGH TUESDAY LOOKS REASONABLE.
&&
.AVIATION...
THRU 26/16Z...ISOLD SHRAS ALONG THE COAST N OF KTIX WILL PRODUCE
BRIEF PDS OF MVFR VSBYS/CIGS...LCL IFR CIGS/MVFR VSBYS IN PASSING
STRATUS AND PATCHY BR ALONG AND N OF THE I-4 CORRIDOR...VFR
ELSEWHERE. BTWN 26/16Z-27/02Z...CHC MVFR SHRAS/ISOLD IFR TSRAS ALL
SITES. AFT 27/02Z...CHC SHRAS S OF KMLB...SLGT CHC N OF KMLB...VFR
INTERIOR SITES.
&&
.MARINE...
TODAY-TONIGHT...LONG E/NE FETCH OVER THE WRN ATLC DUE TO AN
EXPANSIVE HIGH PRES RIDGE EXTENDING FROM ICELAND TO THE NW GOMEX.
THE RIDGE WILL MAINTAIN A GENTLE TO MODERATE E/NE BREEZE THRU
DAYBREAK THU. ERLY SWELLS HAVE BEEN DIMINISHING SLOWLY SINCE PEAKING
EARLY TUE AFTN...CANAVERAL BUOYS MEASURING 4-5FT SWELLS AND
NEARSHORE SCRIPPS BUOYS BTWN 2-3FT. SWELLS WILL DIMINISH ANOTHER
FOOT OR SO BEFORE ENTERING A RATHER STEADY STATE OF 3-4FT AREAWIDE
AROUND MIDDAY...DOMINANT PDS INCREASING FROM 8-9SEC TO ARND 12SEC
AFT MIDNIGHT. CHC SHRAS/SLGT CHC TSRAS MOVING ONSHORE AS DEEP
MOISTURE MOVES UP FROM THE S.
THU-SUN...SURFACE RIDGE AXIS REMAINS NORTH OF THE EAST CENTRAL
FLORIDA COASTAL WATERS. WINDS STAY OUT OF THE EAST TO NORTHEAST AT
15 KNOTS OR LESS. SEAS 4 FEET OR LESS WITH A LONG PERIOD SWELL. LATE
OVERNIGHT AND MORNING SCATTERED SHOWERS AND ISOLATED STORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 85 71 87 73 / 30 20 30 30
MCO 90 71 89 71 / 30 20 30 20
MLB 86 73 86 75 / 30 30 30 30
VRB 86 74 86 75 / 30 30 40 30
LEE 90 71 90 72 / 30 20 30 20
SFB 89 71 89 72 / 30 20 30 20
ORL 90 71 89 73 / 30 20 30 20
FPR 86 74 87 74 / 40 30 40 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...WIMMER
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
320 AM EDT WED SEP 26 2012
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN EVOLVING COMPLEX UPPER
LEVEL PATTERN OVER NORTH AMERICA. NORTHERN STREAM FLOW SPLITS UPON
ARRIVAL OVER THE BRITISH COLUMBIA COAST...WITH ONE BRANCH CONTINUING
ON ACROSS CANADA AND A SECOND BRANCH DIVING SOUTHWARD AND AROUND A
SHORTWAVE IMPULSE OVER THE INTER-MOUNTAIN WEST STATES. THIS BRANCH
THEN BECOMES MORE ZONAL IN NATURE DOWNSTREAM OVER THE NORTHERN GULF
COAST/SOUTHEASTERN STATES. A SOUTHERN STREAM JET CORE THAT HAS BEEN
OVER THE FL PENINSULA THE PAST DAY OR SO IS BEGINNING TO PULL OUT TO
THE NORTHEAST...BUT WILL CONTINUE TO SHOW ITS INFLUENCE OVER THE
SOUTHERN AND CENTRAL PORTIONS OF THE FORECAST AREA IN THE FORM OF
SCT-BKN HIGH LEVEL CIRRUS. 00Z KTBW SOUNDING PROFILE STILL SHOWED A
SIGNIFICANT LAYER OF DRY AIR BETWEEN 850-500MB THIS PAST EVENING
WHICH HELPED ONCE AGAIN SUPPRESS CONVECTION ACROSS THE MAJORITY OF
THE AREA. INDICATIONS ARE THAT WE WILL SEE A SIGNIFICANT MOISTENING
OF THIS LAYER DURING THE NEXT 24 HOURS AND A RE-INTRODUCTION OF AT
LEAST SCATTERED CONVECTION TO THE FORECAST.
AT THE SURFACE...FORECAST AREA REMAINS ON THE SOUTHERN PERIPHERY OF
AN ELONGATED RIDGE OF HIGH PRESSURE EXTENDING FROM THE CAROLINA
COAST TO NORTHERN GA/AL. A PREVAILING EAST TO NORTHEAST FLOW IS
RESULTING INTO THE FL PENINSULA AND HELPING TO TO BRING A RATHER
HUMID AIRMASS BACK TO THE REGION. REGIONAL RADARS SHOWING QUITE A
BIT OF SHOWER/STORM ACTIVITY OFFSHORE OF THE SW FLORIDA COAST
ASSOCIATED WITH A WEAK MID-LEVEL DISTURBANCE. WHILE THIS ACTIVITY IS
CURRENTLY STAYING OFFSHORE...THIS ENERGY WILL LIKELY AID IN THE
DEVELOPMENT OF ADDITIONAL CONVECTION ACROSS THE SOUTHERN PENINSULA
ONCE DIURNAL HEATING COMMENCES.
&&
.SHORT TERM (TODAY THROUGH FRIDAY)...
TODAY...FORECAST AREA WILL REMAIN WITHIN A LOW LEVEL EASTERLY FLOW
AROUND THE CIRCULATION OF HIGH PRESSURE TO OUR NORTH. THE DRY AIR IN
THE MID-LEVELS WHICH HAS SUPPRESSED MUCH OF THE CONVECTION THE PAST
FEW DAYS WILL BE ERODING QUICKLY FROM SOUTH TO NORTH THROUGH THE DAY
RESULTING IN A MUCH LESS HOSTILE ENVIRONMENT TO DEEP CONVECTION BY
THIS AFTERNOON. THE MOST STUBBORN DRY AIR WILL BE OVER THE NATURE
COAST ZONES...ESPECIALLY UP TOWARD CITRUS AND LEVY COUNTIES...AND
WILL HAVE THE LOWEST RAIN CHANCES (~20%) FOR THESE ZONES. RAIN
CHANCES/COVERAGE WILL INCREASE FURTHER SOUTH TO AROUND 30% BY THE
I-4 CORRIDOR AND THEN RANGE UP TO AROUND 50% TOWARD CHARLOTTE AND
LEE COUNTIES. THE HIGHER RAIN CHANCES OVER THE FAR SOUTHERN ZONES
WILL NOT ONLY BE A RESULT OF THE DEEPER MOISTURE...BUT ALSO
INFLUENCED BY A WEAK DISTURBANCE IN THE MID-LEVELS EXTENDING ACROSS
THE SE GULF/SOUTHERN FL PENINSULA. ABUNDANT HIGH LEVEL MOISTURE
ASSOCIATED WITH THE SOUTHERN STREAM JET WILL ALSO KEEP SKIES MOSTLY
CLOUDY WITH SCT-BKN CIRRUS THROUGH THE DAY OVER THE SOUTHERN HALF OF
THE FORECAST AREA. MORE SUN FROM TAMPA BAY NORTHWARD THIS MORNING
WILL GIVE WAY TO PLENTY OF AFTERNOON CU. DESPITE THE HIGH
CLOUDS...ENOUGH INSOLATION IS EXPECTED FOR MOST LOCATIONS TO SEE
TEMPS CLIMB TO WITHIN A DEGREE OR 2 OF 90.
TONIGHT...ISOLATED TO SCATTERED EVENING SHOWERS WILL DISSIPATE
QUICKLY WITH THE LOSS OF DIURNAL HEATING...RESULTING IN A GENERALLY
DRY OVERNIGHT FOR THE LAND ZONES AFTER 02-03Z. THE CONTINUED
INFLUENCE OF THE MID-LEVEL ENERGY WILL LIKELY TRANSITIONS THE SCT
CONVECTION TO THE OFFSHORE ZONES...ESPECIALLY OFFSHORE OF THE
SUNCOAST. LOW TEMPERATURES BY SUNRISE ON THURSDAY SHOULD GENERALLY
RANGE IN THE LOWER 70S...WITH NORMALLY COLDER AREAS THROUGH THE
NATURE COAST ZONES STILL POSSIBLY REACHING THE UPPER 60S. THE EAST
FLOW OFF TAMPA BAY WILL ALSO HELP KEEP CENTRAL AND SOUTHERN PORTIONS
OF PINELLAS COUNTY WARMER.
THURSDAY/FRIDAY...THE OVERALL SYNOPTIC PATTERN WILL NOT CHANGE MUCH
DURING THE LATER PORTION OF THE WORK WEEK. THERE ARE SOME
INDICATIONS THAT THE HIGHER LEVEL CIRRUS WILL BE EXPANDING BACK TO
THE NORTH TO AT LEAST FILTER THE SUNSHINE OVER ALL ZONES. DEPENDING
ON JUST HOW THICK THIS CIRRUS ENDS UP BEING...HIGH TEMPS MAY BE A
COUPLE OF DEGREES COOLER THAN ADVERTISED...WHICH ARE CURRENTLY A
CLOSE BLEND OF THE MAV/MET NUMBERS. AS FOR RAIN CHANCES...WILL
CONTINUE A PATTERN OF MOSTLY DRY CONDITIONS AT NIGHT...FOLLOWED BY
ISOLATED TO WIDELY-SCT CONVECTION NORTH...AND SCT STORMS SOUTH
DURING THE LATER MORNING THROUGH MIDDLE EVENING HOURS.
&&
.LONG TERM (SATURDAY THROUGH NEXT TUESDAY)...
MODELS HAVE COME INTO BETTER AGREEMENT WITH REGARDS TO THE UPPER-AIR
PATTERN IN THE EXTENDED PORTION OF THE FORECAST BUT ARE STILL
STRUGGLING WITH SURFACE FEATURES. THE UPPER-LEVEL PATTERN WILL BE
QUITE COMPLEX AS A TROUGH OF LOW PRESSURE TAKES SHAPE OVER THE
EASTERN HALF OF THE NATION ON SATURDAY AND REMAINS LOCKED IN THROUGH
TUESDAY. AT THE SURFACE...THE GFS IS STILL THE OUTLIER IN SHOWING A
FRONTAL BOUNDARY MOVING THROUGH CENTRAL FLORIDA ON SUNDAY. THE 12Z
ECMWF AND THE 00Z CANADIAN HOLD THE SURFACE RIDGE OVER CENTRAL
FLORIDA ON SUNDAY WITH THE FRONT REMAINING WELL TO THE NORTHWEST. ON
MONDAY...THE ECMWF HAS A LOW PRESSURE AREA MOVING NORTHEAST ACROSS
THE NORTHERN GULF COAST...BUT IS OTHERWISE STILL SIMILAR TO THE CMC
WITH THE FRONT STILL NORTH OF THE REGION. THE FRONT DOES SLIP INTO
THE NORTHEAST GULF BY TUESDAY BUT THE UPPER-LEVEL SUPPORT BEGINS TO
LIFT OUT TO THE NORTHEAST. WE COULD BE LOOKING AT A RATHER WET
PERIOD OF WEATHER NEXT WEEK IF THE FRONTAL BOUNDARY REMAINS NEARBY
AND THE UPPER-LEVEL TROUGHING PERSISTS.
AS FOR THE FORECAST...SATURDAY LOOKS LIKE THE BEST OF THE TWO
WEEKEND DAYS WITH LOW-END CHANCE POPS DURING THE AFTERNOON HOURS. I
DID INCREASE RAIN CHANCES A BIT FOR SUNDAY AS WE WILL BE IN A SOUTH
TO SOUTHEASTERLY SURFACE FLOW WITH UPPER-LEVEL CYCLONIC FLOW IN
PLACE. STILL EXPECT MOST OF THE RAIN TO HOLD OFF UNTIL THE AFTERNOON
HOURS.
FOR MONDAY AND TUESDAY...WE WILL HAVE DEEP MOISTURE IN PLACE AHEAD
OF THE UPPER-LEVEL TROUGH...AND THE SURFACE BOUNDARY WILL BE JUST TO
OUR NORTHWEST. THIS SHOULD SET THE STAGE FOR SCATTERED SHOWERS AND
THUNDERSTORMS AT JUST ABOUT ANY TIME DURING THE DAY OR NIGHT.
TEMPERATURES DURING THIS PERIOD SHOULD BE NEAR OR JUST A BIT ABOVE
NORMAL.
&&
.MARINE...
THE EASTERN GULF OF MEXICO REMAINS WITHIN AN EASTERLY FLOW REGIME
AROUND THE SOUTHERN PERIPHERY OF AN ELONGATED RIDGE OF HIGH PRESSURE
EXTENDING FROM THE CAROLINA COAST TO NORTHERN ALABAMA. NEAR
CAUTIONARY LEVEL WINDS OFFSHORE OF THE NATURE COAST EARLY THIS
MORNING SHOULD DIMINISH QUICKLY AFTER SUNRISE...WITH WINDS BECOMING
LIGHT ALONG THE ENTIRE COAST BY THIS AFTERNOON. ANOTHER BRIEF SURGE
OF EASTERLY FLOW IS EXPECTED TONIGHT...ALTHOUGH WINDS SHOULD REMAIN
BELOW CAUTIONARY LEVELS...EVEN OVER THE NORTHERN MARINE LEGS. THE
RIDGE TO OUR NORTH IS EXPECTED TO WEAKEN DURING THE LATER PORTION OF
THE WEEK AND HELP KEEP WINDS AND SEAS WELL BELOW HEADLINE CRITERIA.
&&
.AVIATION...
VFR NEXT 24 HOURS. ONCE AGAIN CAN NOT RULE OUT A BIT OF PATCHY
GROUND FOG TOWARD SUNRISE NEAR LAL AND PGD. ALSO...MOISTURE WILL BE
INCREASING SO WE MAY SEE SOME SHOWERS AND STORMS IN THE VICINITY
MAINLY BETWEEN 18 AND 00Z.
&&
.FIRE WEATHER...
EASTERLY FLOW WILL CONTINUE TO SUPPLY ABUNDANT LOW LEVEL ATLANTIC
MOISTURE AND PREVENT CRITICAL FIRE WEATHER CONDITIONS THE NEXT
SEVERAL DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 75 89 74 / 30 20 40 20
FMY 89 75 90 74 / 50 20 50 20
GIF 91 73 90 72 / 30 20 40 20
SRQ 89 73 89 73 / 40 20 40 20
BKV 91 71 89 69 / 30 20 40 10
SPG 90 78 88 76 / 30 20 40 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...JILLSON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
123 AM EDT WED SEP 26 2012
.AVIATION.../06Z TAFS/
SOUTHERLY LOW LEVEL FLOW CONTS TO ADVECT A MOIST AIRMASS INTO NRN
INDIANA EARLY THIS MORNING RESULTING IN SLOW DETERIORATION TO
CIGS/VSBYS AS STRATUS/FOG FORMS. IN ADDITION...TSTMS HAVE
DEVELOPED OVER SRN PORTIONS OF THE AREA. EXPECT THIS ACTIVITY TO
REMAIN SOUTH OF FWA BUT CLOSE ENOUGH TO INCLUDE VCTS EARLY IN THE
TAF PERIOD. OTRWS CONTD WITH SLOWLY LOWERING CIGS/VSBYS EXPECTED THROUGH
DAYBREAK WITH SLOW IMPROVEMENT LATER THIS MORNING THROUGH MIDDAY.
CDFNT ACROSS MI/NW IL IS RATHER DIFFUSE BUT A GRADUAL WIND SHIFT
TO NORTH SHOULD OCCUR AT SBN AROUND 12Z AND AT FWA BY 18Z.
&&
.PREV DISCUSSION... /ISSUED 745 PM EDT TUE SEP 25 2012/
UPDATE...
GOING GRIDS WILL BE NEED SOME WORK WITH OBVIOUS DISCREPENCIES
BETWEEN SKY COVER AND TAFS. FAVOR INCREASING STRATUS THROUGH THE
NIGHT CENTRAL AND NORTH WITH MOISTURE POOLING HELPING SOME FOG TO
DEVELOP GIVEN WEAK WIND FIELDS. HRRR REALLY PICKING UP ON THIS AS IT
DID SEVERAL NIGHTS AGO. EXPECTING THE STRATUS DEVELOPMENT TO HELP
KEEP VIS IN THE 2SM TO 4SM RANGE GIVEN LACK OF RAIN TODAY. HOWEVER
THIS IS DEPENDENT ON DEPTH AND AMOUNT OF STRATUS DEVELOPMENT.
EXCEPTION TO THIS IS IN THE SOUTH WHERE IT DID RAIN TODAY BUT CLOUDS
EXPECTED CONTINUE THIS EVENING WITH LITTLE CLEARING WHICH SHOULD
HELP OFFSET ANY FOG DEVELOPMENT.
SHORT TERM.../TONIGHT THROUGH WEDNESDAY NIGHT/
MCV CURRENTLY MOVING ACROSS FAR SOUTHERN COUNTIES WILL QUICKLY EXIT
BY 21Z. SUBSIDENCE IN ITS WAKE WILL LIKELY HELP SET THE STAGE FOR
DIMINISHING CHANCES OF ADDITIONAL PRECIP INTO TONIGHT. PRE 1ST
PERIOD MENTION OF INCREASED POPS TO COVER DEPARTURE OF THIS
FEATURE. VIS SAT/SFC OBS INDICATE NOSE OF INCREASING THETA E
EDGING INTO E ILLINOIS WITH A BATCH OF LOW CLOUDS ASSOCIATED WITH
IT. WILL CONTINUE TO MONITOR THIS FEATURE FOR ANY SHOWER
DEVELOPMENT BUT SUSPECT NOTHING WILL COME OF IT WITH MAIN FORCING
SOUTH. COLD FRONT TO THE NORTH HAS SLOWED AS EXPECTED WITH MODELS
STILL DROPPING IT SOUTH INTO NORTHERN AREAS LATER TONIGHT. BY THE
TIME IT ARRIVES...LITTLE IMPACT IN TERMS OF POPS IS EXPECTED...BUT
ASSOCIATED MSTR WITH IT COULD AID IN STRATUS/FOG POTENTIAL. HAVE
STAYED CONSERVATIVE AND WENT WITH CLEARING TREND NORTH AND HANG
ONTO CLOUDS SOUTH. GIVEN TRENDS...JUST CAN`T SEE HOLDING ONTO
LIKELY POPS IN FAR SOUTH AND AFTER COORDINATION HAVE LOWERED TO
HIGH END CHC. ALSO TAPERED POPS QUICKLY TO THE NORTH.
ON WEDS...COLD FRONT WILL DROP INTO THE AREA. POTENTIAL FOR LATE
MORNING INTO AFTERNOON CONVECTION ON THE FRONT REMAINS AS ENERGY
MOVES ALONG THE FRONT. HOWEVER...EFFECTIVE LL MSTR COULD BE GUTTED
ALREADY FROM OVERNIGHT CONVECTION TO THE SOUTH ALLOWING FOR AT MOST
SCT SHOWERS SE. ONLY MINOR CHANGES TO GRIDS WITH TEMPS STILL VERY
SEASONABLE AROUND 70. FRONT WILL BE WELL SOUTH OF THE AREA BY WEDS
NGT WITH CLEAR SKIES AND SEASONABLE LOWS.
LONG TERM...
PERIOD WILL BE DOMINATED BY SPRAWLING HIGH PRESSURE ACROSS THE
REGION. AS HUDSON BAY UPPER LOW DEPARTS ANOTHER WAVE WILL TAKE ITS
PLACE WITH SOUTHERN EXTENSION SWEEPING ACROSS THE GREAT LAKES.
FEATURE WILL BE MSTR STARVED WITH ONLY REAL EFFECT BEING A
CONTINUATION OF NEAR NORMAL TEMPERATURES AND NO APPRECIABLE PRECIP
CHANCES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...T
AVIATION...JT
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1230 AM EDT WED SEP 26 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 PM EDT TUE SEP 25 2012
AN ACTIVE WEATHER PATTERN WILL KEEP CHANCES FOR SHOWERS AND
THUNDERSTORMS OVER PARTS OF THE AREA THROUGH THE WORK WEEK. HIGH
PRESSURE WILL BUILD IN OVER THE WEEKEND AND DRY THINGS OUT.
TEMPERATURES WILL BEGIN NEAR/JUST ABOVE NORMAL BUT SHOULD DIP TO
NEAR/JUST BELOW NORMAL AS AN UPPER TROUGH SETTLES IN FROM CANADA.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1004 PM EDT TUE SEP 25 2012
MAIN BAND OF THUNDERSTORMS HAS FINALLY ENTERED THE EXTREME SOUTHWEST
PORTION OF THE FORECAST AREA WITHIN THE LAST HOUR. STORMS HAVE BEEN
SLOWLY DIMINISHING IN INTENSITY AS THEY MADE THEIR WAY ACROSS
ILLINOIS SO DO NOT EXPECT MUCH IN THE WAY OF SEVERE. HOWEVER...SOME
SMALL HAIL AND WIND GUSTS UP TO 40 MPH ARE NOT OUT OF THE QUESTION
FOR THE NEXT HOUR OR TWO.
IN REGARDS TO THE FORECAST...MAIN CHANGE WAS TO ADJUST POPS FOR
CURRENT CONDITIONS. CONDITIONS HAVE BEEN DRY THIS EVENING ACROSS THE
NORTHERN TWO THIRDS OF THE AREA EXCEPT FOR A FEW SCATTERED LIGHT
SHOWERS. THEREFORE...CUT POPS WAY BACK ACROSS THIS AREA FOR THE
REMAINDER OF THE EVENING WITH JUST SOME SHOWER MENTION. THE RAP HAS
HAD A PRETTY DECENT HANDLE ON THE CONVECTION TONIGHT SO WILL FOLLOW
ITS PROJECTION OF INCREASING SHOWERS...AND PROBABLY SOME
THUNDER...IN THE 06-09Z TIME FRAME. THE BEST FORCING AND ASSOCIATED
VORTICITY MAX LOOK TO PASS THROUGH DURING THIS TIME FRAME...FOCUSING
MAINLY ON THE SOUTHERN TWO THIRDS OF THE AREA WHERE I KEPT THE
HIGHEST POPS. ADDITIONALLY...THE LOW LEVEL JET REALLY BEGINS TO RAMP
UP AFTER 06Z AND PRECIPITABLE WATER VALUES INCREASE TO NEAR 1.75
INCHES.
TEMPERATURES LOOK TO MAINLY BE ON TRACK...JUST BUMPED UP LOWS A
DEGREE OR TWO IN THE EXTREME SOUTH WITH TEMPERATURES STILL IN THE
UPPER 60S IN PLACES WHERE STORMS ALREADY MOVED THROUGH.
UPDATED GRIDS AND ZONES ALREADY SENT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 337 PM EDT TUE SEP 25 2012
FORECAST FOCUS IS ON POPS. RELATIVELY ZONAL FLOW WILL ALLOW
SHORTWAVES TO RAPIDLY MOVE THROUGH THE FLOW AND PROVIDE
PRECIPITATION TO THE AREA DURING THE SHORT TERM. WITH A FRONT
SAGGING SOUTH THROUGH THE AREA AND A SHORT WAVE MOVING THROUGH THE
FLOW WILL KEEP SOME CATEGORICAL POPS GOING ON WEDNESDAY WITH
LIKELIES ACROSS ALL BUT THE NORTHWEST AS BEST FORCING AGAIN WILL BE
FOCUSED ALONG AND SOUTH OF THE FRONTAL BOUNDARY. AS THE FRONT SINKS
SOUTH POPS DECREASE IN TIME FROM NORTH TO SOUTH WITH SURFACE HIGH
PRESSURE BUILDING IN FROM THE NORTH. WHILE ENOUGH FORCING AND
INSTABILITY WILL BE AROUND WEDNESDAY AND WEDNESDAY NIGHT TO WARRANT
CHANCES FOR THUNDERSTORMS...BY THURSDAY THERE IS LITTLE LEFT AND
WILL JUST KEEP A SLIGHT CHANCE IN THE FAR SOUTH WHERE A BIT OF
ELEVATED INSTABILITY MAY STILL RESIDE.
WITH THE FRONT SERVING AS A FOCUSING MECHANISM FOR PRECIPITATION
THE NEXT COUPLE OF DAYS AND GOOD FLOW OFF THE GULF COULD SEE SOME
POTENTIAL FOR LOCALIZED NUISANCE FLOODING. AT THIS POINT DOESN/T
LOOK WIDESPREAD ENOUGH TO NECESSITATE A HEADLINE BUT WILL NEED TO
WATCH.
FOR TEMPERATURES GENERALLY THOUGHT A CONSENSUS WORKED WELL AS MUCH
IS CONTINGENT UPON EXACT FRONTAL POSITION AND ATTENDANT CLOUD COVER.
HIGHS IN THE 70S ON WEDNESDAY WITH 60S WORKING THEIR WAY INTO THE
NORTH ON THURSDAY AND FRIDAY WITH A BIT OF COLD ADVECTION UP THERE.
LOWS MAINLY IN THE 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 141 PM EDT TUE SEP 25 2012
THE MAIN FOCUS TO THE EXTENDED WILL BE WHETHER OR NOT TO KEEP LOW
POPS ACROSS THE SOUTH FRIDAY NIGHT AND SATURDAY PER THE CENTRAL
REGION INITIALIZATION. LONG RANGE MODELS ARE IN GOOD AGREEMENT ON A
DRY FORECAST FOR THE REMAINDER OF THE EXTENDED AS A BROAD AREA OF
SURFACE HIGH PRESSURE SETS UP ACROSS THE OHIO VALLEY WITH A LOW
PRESSURE SYSTEM WELL TO THE SOUTH ACROSS THE SOUTHERN STATES AND AN
UPPER LOW NEAR THE SAINT LAWRENCE VALLEY.
WITH THE LONG RANGE MODELS STILL SHOWING A GOOD DEGREE OF MODEL TO
MODEL AND MODEL VERSUS MODEL UNCERTAINTY...WILL ACCEPT THE SMALL
POPS FROM CR INIT FRIDAY NIGHT ACROSS THE WHOLE FORECAST AREA AND
SATURDAY ACROSS JUST OUR FAR SOUTH. WILL ALSO ACCEPT THE SLIGHTLY
BELOW NORMAL TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR 260600Z TAF ISSUANCE/...
ISSUED AT 1230 AM EDT WED SEP 26 2012
NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE TO MOVE EAST ACROSS
SOUTHERN ILLINOIS INTO SOUTHERN INDIANA OVERNIGHT AS AN 850 MB JET
POINTS INTO THIS REGION. TIME HEIGHT CROSS SECTIONS AND MODEL
GUIDANCE INDICATE AREAS OF STRATUS WILL DEVELOP OVERNIGHT AS SOME
LOW LEVEL COOLING OCCURS. WILL FORECAST CEILINGS ABOUT 3 THOUSAND
FEET MOST AREAS FOR A FEW MORE HOURS AND CEILINGS OF 1 TO 2 THOUSAND
FEET BY 09Z OR 10Z AND CONTINUING TO ABOUT MIDDAY. FOG POSSIBLE SOME
AREAS OVERNIGHT AS WELL.
THERE WILL BE PROBABLY ENOUGH DAYTIME MIXING TO MIX OUT ANY STRATUS
BY MIDDAY. MODELS INDICATE A COLD FRONT WILL PUSH SLOWLY SOUTH
ACROSS OUR REGION THIS AFTERNOON AND EARLY TONIGHT. ONLY CHANGE
WILL BE TO DOWNPLAY SHOWERS AND THUNDERSTORMS IN KLAF AREA AS MOST
OF THIS WILL OCCUR FARTHER SOUTH. OTHERWISE WILL MENTION VCTS MOST
AREAS WEDNESDAY AS THE COLD FRONT MOVES INTO OUR REGION.
WINDS WILL BE 6 KNOTS OR LESS OVERNIGHT AND SOUTHWEST OR WEST AROUND
10 KNOTS BY MIDDAY WEDNESDAY. WINDS WILL BECOME NORTHERLY 8 KNOTS
OR LESS WEDNESDAY NIGHT AND LIGHT AT KBMG.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...HOMANN
SHORT TERM...CP
LONG TERM....MK
AVIATION...JH/JP
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
358 AM CDT WED SEP 26 2012
...UPDATED FOR LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1214 AM CDT WED SEP 26 2012
AT 00Z WEDNESDAY A 500MB LOW WAS LOCATED JUST NORTH OF THE FOUR
CORNERS REGION WITH A 250MB 55KT JET STREAK LOCATED ON ITS WEST
SIDE DIVING SOUTH ACROSS WESTERN NEVADA. ANOTHER 50KT JET WAS
LOCATED IN THE BASED ON THIS UPPER LOW/TROUGH OVER NORTHERN
NEVADA. FURTHER EAST ACROSS SOUTHWEST KANSAS THE WATER VAPOR LOOP
AND RAP 400MB POTENTIAL VORTICITY INDICATED AN UPPER LEVEL TROUGH
MOVING EAST FROM SOUTHEAST COLORADO INTO SOUTHWEST KANSAS. CLOUD
TOPS WERE COOLING AHEAD OF THIS FEATURE FROM 00Z- 02Z. A 700MB
BAROCLINIC ZONE WAS ALSO LOCATED IN THIS AREA AT 00Z AND AT THE
850MB LEVEL WARM AIR ADVECTION WAS LOCATED ALONG AND NORTH OF A
SURFACE BOUNDARY WHICH WAS LOCATED FROM THE PANHANDLE OF OKLAHOMA
ACROSS SOUTH CENTRAL KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 147 AM CDT WED SEP 26 2012
SATELLITE LOOP INDICATING SKIES ATTEMPTING TO CLEAR BEHIND THE
FIRST UPPER LEVEL TROUGH THAT WAS CROSSING SOUTHWEST KANSAS
EARLIER THIS MORNING. THIS FIRST WAVE WAS REFLECTED WELL BY THE
WATER VAPOR LOOP AND RAP 400MB POTENTIAL VORTICITY. AS THIS SYSTEM
EXITS WESTERN KANSAS THE PRECIPITATION CHANCES WILL DROP WITH THE
POSSIBLE EXCEPTION OF NORTH CENTRAL KANSAS AS ANOTHER WEAKER WAVE
CROSSES SOUTHWEST KANSAS EARLY WEDNESDAY MORNING. WILL MONITOR
TREND AND INSERT A PERIOD OF EARLY MORNING CLOUDS AND POSSIBLE
LIGHT RAINSHOWERS/SPRINKLES AS NEEDED.
THE NEXT DECENT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE
TODAY AND ESPECIALLY OVERNIGHT AS THE UPPER LEVEL JET THAT WAS
LOCATED OVER NEVADA ROTATES AROUND THE 500MB LOW AND APPROACHES
THE AREA. NAM AND GFS WERE IN DECENT AGREEMENT WITH THE PLACEMENT
OF THIS UPPER LEVEL FEATURE LATE TODAY WITH IMPROVING 850-700MB MOISTURE
AND FRONTOGENESIS DEVELOPING NORTH OF THE COLD FRONT. 00Z NAM AND
00Z GFS DO HOWEVER DIFFER SLIGHTLY ON THE LOCATION ON WHERE THE
BETTER FRONTOGENESIS BUT THE GENERAL TREND IS CONVECTION CHANCES
IMPROVING FROM WEST TO EAST LATE TODAY ACROSS WESTERN KANSAS.
AROUND 40 KNOTS OF 0-6KM SHEAR ARE EXPECTED BY LATE DAY BASED ON
THE 00Z NAM. CAPE VALUES WILL ACROSS WESTERN KANSAS ARE EXPECTED
TO BE AROUND 1000J/KG WITH 0-2.5KM LAPSE RATES EXCEEDING 8C/KM.
GIVEN THIS AND SOME LATE DAY FORCING DEVELOPING WILL KEEP A
MENTION OF SEVERE STORMS GOING IN THE HAZARDOUS WEATHER OUTLOOK.
MAIN HAZARD APPEARS TO BE HAIL.
AS FOR TEMPERATURES...THE OVERNIGHT RAINFALL AND EXPECTED CLOUD
COVER LATER TODAY SHOULD LIMIT THE WARM UP THIS AFTERNOON. AT THIS
TIME WILL TREND TOWARDS THE COOLER GUIDANCE WHICH SUPPORTS THE
850MB MIX DOWN TEMPERATURES FROM THE NAM AND GFS ALONG WITH WHAT
THE PREVIOUS SHIFT SUGGESTED. WILL ALSO NOT DEVIATE FAR FROM THE
LOWS TONIGHT GIVEN THE MID 50S TO NEAR 60 DEWPOINTS FORECAST NORTH
OF THE FRONT ACROSS SOUTHWEST KANSAS AND EXPECTED CLOUD COVER.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED SEP 26 2012
THE NEXT SHORTWAVE TROUGH WILL APPROACH WESTERN KANSAS THURSDAY.
WITH ABUNDANT LOW LEVEL MOISTURE IN PLACE, THERE IS A GOOD CHANCE
FOR SHOWERS AND THUNDERSTORMS. PRECIPITATION WILL AIDED BY LIFT
IN THE LEFT EXIT REGION OF A 90 KT JET STREAK WITH ASSOCIATED MID-
LEVEL BAROCLINIC ZONE AND ISENTROPIC LIFT. THE POTENTIAL FOR
SEVERE WEATHER MAY BE LOW BECAUSE OF WIDESPREAD CLOUD COVER AND
COOL SURFACE TEMPERATURES. HOWEVER, A FEW ELEVATED SEVERE STORMS
WITH LARGE HAIL CANNOT BE RULED OUT GIVEN THE APPROACH OF THE
100KT UPPER-LEVEL JET, PLENTIFUL MOISTURE AND FAIRLY COOL
TEMPERATURES AT 500MB.
STORM CHANCES DECREASE AFTER THURSDAY WHEN THIS SYSTEM PASSES.
HOWEVER, GENERAL UPPER-LEVEL TROUGHINESS WILL REMAIN, AND WITH
RESIDUAL LOW LEVEL MOISTURE AND FAIRLY COOL 500MB TEMPERATURES
PERSISTING, SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
CONTINUE INTO FRIDAY AND SATURDAY. HIGH TEMPERATURES WILL STAY
RATHER COOL GIVEN THE CLOUD COVER AND FAIRLY COOL AIRMASS STILL IN
PLACE. LOW TEMPERATURES ARE EXPECTED TO SLOWLY FALL AS DEWPOINTS
GRADUALLY DECREASE.
DRY WEATHER AND A WARMING TREND WILL COMMENCE BY SATURDAY AND
CONTINUE THROUGH MID NEXT WEEK AS UPPER-LEVEL RIDGING BUILDS OVER THE
ROCKIES AND WESTERN HIGH PLAINS. HIGH TEMPERATURES OUGHT TO WARM
INTO THE UPPER 70S BY SUNDAY AND 80S BY MONDAY AND TUESDAY. EVEN
WARMER HIGH TEMPERATURES IN THE UPPER 80S TO LOWER 90S ARE POSSIBLE
BY MID NEXT WEEK AS UPPER-LEVEL TROUGHING BEGINS TO DEVELOP ALONG
THE WEST COAST, WITH LEE TROUGHING AND WEAK DOWNSLOPE LOW-LEVEL
FLOW ON THE HIGH PLAINS. AFTER COORDINATION WITH SURROUNDING OFFICES,
IT WAS DECIDED TO RAISE MAXIMUM TEMPERATURES ABOVE THOSE GIVEN BY THE
CENTRAL REGION INITIALIZATION GRIDS. THESE TEMPERATURES MAY STILL
BE TOO COOL. LOWS SHOULD BE MAINLY IN THE 50S THROUGH NEXT WEEK,
WITH SOME 40S POSSIBLE IN THE TRADITIONALLY COOLER AREAS NEAR THE
COLORADO BORDER ON THE HIGHER TERRAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1214 AM CDT WED SEP 26 2012
HAYS REMAINS IN A FAVORABLE ENVIRONMENT FOR ONGOING CONVECTION
FOR THE NEXT FEW HOURS BASED ON 05Z ONGOING CONVECTION, TRACK OF
THE UPPER TROUGH FROM WATER VAPOR LOOP, RAP 400MB POTENTIAL
VORTICITY AND RAP MUCAPES NORTH OF THE SURFACE FRONT. THIS AREA
WILL SHIFT EAST BY 08Z AND THE SURFACE BOUNDARY WILL MOVE FURTHER
SOUTH INTO OKLAHOMA. BEHIND THIS FRONT NORTH/NORTHEAST WINDS AT
AROUND 10KTS CAN BE EXPECTED THROUGH WEDNESDAY EVENING ACROSS ALL
OF WESTERN KANSAS. VFR CIGS ARE EXPECTED BASED ON 00Z NAM MODEL
SOUNDINGS. A FEW SPRINKLE WILL BE POSSIBLE ON EARLY WEDNESDAY AS A
SUBTLE DISTURBANCE CROSSES SOUTHWEST KANSAS BUT AT THIS TIME WILL
NOT INCLUDE MENTION OF PRECIPITATION AT ANY TAF SITES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 81 58 76 61 / 30 60 60 50
GCK 79 56 75 59 / 40 50 50 40
EHA 83 55 76 58 / 40 50 40 30
LBL 85 57 77 60 / 30 50 60 40
HYS 78 56 74 59 / 30 40 40 40
P28 83 62 78 62 / 30 50 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION...CORRECTED
NWS DODGE CITY KS
244 AM CDT WED SEP 26 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1214 AM CDT WED SEP 26 2012
AT 00Z WEDNESDAY A 500MB LOW WAS LOCATED JUST NORTH OF THE FOUR
CORNERS REGION WITH A 250MB 55KT JET STREAK LOCATED ON ITS WEST
SIDE DIVING SOUTH ACROSS WESTERN NEVADA. ANOTHER 50KT JET WAS
LOCATED IN THE BASED ON THIS UPPER LOW/TROUGH OVER NORTHERN
NEVADA. FURTHER EAST ACROSS SOUTHWEST KANSAS THE WATER VAPOR LOOP
AND RAP 400MB POTENTIAL VORTICITY INDICATED AN UPPER LEVEL TROUGH
MOVING EAST FROM SOUTHEAST COLORADO INTO SOUTHWEST KANSAS. CLOUD
TOPS WERE COOLING AHEAD OF THIS FEATURE FROM 00Z- 02Z. A 700MB
BAROCLINIC ZONE WAS ALSO LOCATED IN THIS AREA AT 00Z AND AT THE
850MB LEVEL WARM AIR ADVECTION WAS LOCATED ALONG AND NORTH OF A
SURFACE BOUNDARY WHICH WAS LOCATED FROM THE PANHANDLE OF OKLAHOMA
ACROSS SOUTH CENTRAL KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 147 AM CDT WED SEP 26 2012
SATELLITE LOOP INDICATING SKIES ATTEMPTING TO CLEAR BEHIND THE
FIRST UPPER LEVEL TROUGH THAT WAS CROSSING SOUTHWEST KANSAS
EARLIER THIS MORNING. THIS FIRST WAVE WAS REFLECTED WELL BY THE
WATER VAPOR LOOP AND RAP 400MB POTENTIAL VORTICITY. AS THIS SYSTEM
EXITS WESTERN KANSAS THE PRECIPITATION CHANCES WILL DROP WITH THE
POSSIBLE EXCEPTION OF NORTH CENTRAL KANSAS AS ANOTHER WEAKER WAVE
CROSSES SOUTHWEST KANSAS EARLY WEDNESDAY MORNING. WILL MONITOR
TREND AND INSERT A PERIOD OF EARLY MORNING CLOUDS AND POSSIBLE
LIGHT RAINSHOWERS/SPRINKLES AS NEEDED.
THE NEXT DECENT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE
TODAY AND ESPECIALLY OVERNIGHT AS THE UPPER LEVEL JET THAT WAS
LOCATED OVER NEVADA ROTATES AROUND THE 500MB LOW AND APPROACHES
THE AREA. NAM AND GFS WERE IN DECENT AGREEMENT WITH THE PLACEMENT
OF THIS UPPER LEVEL FEATURE LATE TODAY WITH IMPROVING 850-700MB MOISTURE
AND FRONTOGENESIS DEVELOPING NORTH OF THE COLD FRONT. 00Z NAM AND
00Z GFS DO HOWEVER DIFFER SLIGHTLY ON THE LOCATION ON WHERE THE
BETTER FRONTOGENESIS BUT THE GENERAL TREND IS CONVECTION CHANCES
IMPROVING FROM WEST TO EAST LATE TODAY ACROSS WESTERN KANSAS.
AROUND 40 KNOTS OF 0-6KM SHEAR ARE EXPECTED BY LATE DAY BASED ON
THE 00Z NAM. CAPE VALUES WILL ACROSS WESTERN KANSAS ARE EXPECTED
TO BE AROUND 1000J/KG WITH 0-2.5KM LAPSE RATES EXCEEDING 8C/KM.
GIVEN THIS AND SOME LATE DAY FORCING DEVELOPING WILL KEEP A
MENTION OF SEVERE STORMS GOING IN THE HAZARDOUS WEATHER OUTLOOK.
MAIN HAZARD APPEARS TO BE HAIL.
AS FOR TEMPERATURES...THE OVERNIGHT RAINFALL AND EXPECTED CLOUD
COVER LATER TODAY SHOULD LIMIT THE WARM UP THIS AFTERNOON. AT THIS
TIME WILL TREND TOWARDS THE COOLER GUIDANCE WHICH SUPPORTS THE
850MB MIX DOWN TEMPERATURES FROM THE NAM AND GFS ALONG WITH WHAT
THE PREVIOUS SHIFT SUGGESTED. WILL ALSO NOT DEVIATE FAR FROM THE
LOWS TONIGHT GIVEN THE MID 50S TO NEAR 60 DEWPOINTS FORECAST NORTH
OF THE FRONT ACROSS SOUTHWEST KANSAS AND EXPECTED CLOUD COVER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 309 PM CDT TUE SEP 25 2012
THURSDAY WILL START WITH A BROAD UPPER LEVEL WAVE PASSING THROUGH
WESTERN KANSAS, ALONG WITH A NEARLY STATIONARY FRONT LAYING ACROSS
OUR CWA. THEREFORE, POPS WILL BE IN THE 30 PERCENT RANGE WEST TO
THE 50 PERCENT RANGE IN OUR SOUTHEASTERN CWA. THERE WILL BE A
BLANKET OF LOWER TO MID CLOUDS OVERHEAD WITH LITTLE INSOLATION.
HIGHS SHOULD ONLY REACH THE MID TO UPPER 70S, AND RAINFALL WILL
LIKELY VARY FROM .02 TO .40 INCH. THURSDAY NIGHT AND FRIDAY WILL
BE VERY SIMILAR WITH THE UPPER WAVE STRETCHING ACROSS WESTERN AND
CENTRAL KANSAS, AND THE AFOREMENTIONED FRONT WILL BE MEANDERING
NORTH AND THEN SOUTH OVER OUR FORECAST AREA. PRECIPITATION CHANCES
WILL STILL BE IN THE 25 TO 50 PERCENT RANGE, HIGHEST IN THE EAST
WHERE DEWPOINTS WILL BE HIGHEST IN THE 60 TO 63 DEGREE RANGE. QPF
WILL BE A LITTLE HIGHER IN THE EASTERN ZONES THAN IN THE WEST, DUE
TO HIGHER MOISTURE CONTENT. THE AXIS OF THE UPPER WAVE SHOULD
CROSS TO THE EAST OF US BY SATURDAY, BUT THE FRONT WILL STILL BE
IN THE AREA. SO POPS WILL FALL INTO THE 20 TO 30 PERCENT RANGE
SATURDAY MORNING, AND THEN TO THE 20 PERCENT OR LESS RANGE
SATURDAY AFTERNOON. BUT, JUST AS THAT ONE WAVE IS LEAVING OUR
AREA, ANOTHER RIPPLE WILL COME THROUGH SATURDAY NIGHT, RESULTING
IN 20 PERCENT POPS SATURDAY NIGHT IN OUR WEST, THEN SHIFTING TO 20
PERCENT POPS IN OUR EAST SUNDAY. THE LARGE SYNOPTIC SCALE LOW WILL
STAY ANCHORED OVER THE COAST OFF BAJA CALIFORNIA THROUGH THE 7 DAY
PERIOD, THEN GET INGESTED INTO AN EVEN LARGER SCALE UPPER LOW
ENTERING THE NORTHWESTERN U.S. BY NEXT WEDNESDAY, OCTOBER 3RD. BY
SUNDAY, I THINK HIGH PRESSURE WILL BE BUILDING IN AT THE H5 AND H7
LEVELS MONDAY INTO TUESDAY, BRINGING AN END TO PRECIPITATION
CHANCES. THEREFORE, MONDAY INTO TUESDAY, DAYS 6 AND 7, WILL SEE AN
END TO PRECIPITATION AND A LOT MORE SUNSHINE AS WELL AS A WARM UP.
MAXIMUM TEMPERATURES FRIDAY AND SATURDAY WILL BE COOL AND GENERALLY
IN THE LOW 70S NORTH TO THE MID 70S SOUTHEAST. MINIMUM TEMPERATURES
FRIDAY IN THE UPPER 50S TO LOWER 60S WILL COOL TO MONDAY MORNING
READINGS RANGING FROM AROUND 50 DEGREES IN THE SYRACUSE TO
WAKEENEY AREA, TO NEAR 54 DEGREES IN THE COLDWATER AND MEDICINE
LODGE AREAS. SUNDAY`S MAX TEMPS WILL WARM TO THE MID TO UPPER 70S,
THEN ON MONDAY TO THE UPPER 70S TO CLOSE TO 80 DEGREES, AND BY
TUESDAY CLIMB TO THE UPPER 70S TO LOWER 80S. MINIMUM TEMPERATURES
WILL WARM A LITTLE BY TUESDAY MORNING TO THE MID 50S IN MOST
LOCATIONS.
OVERALL, THE ECMWF MODEL AND THE GEM ARE IN GOOD AGREEMENT OUT TO
ABOUT 132HRS, OR 30/12Z AND WERE LEANED TOWARD MORE THAN THE GFS.
THE GFS MODEL IS FASTER WITH EXITING THE FIRST UPPER WAVE, WHILE THE
ECMWF AND GEM BOTH DRAG THIS UPPER FEATURE THROUGH THE PLAINS
WEDNESDAY THROUGH SATURDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1214 AM CDT WED SEP 26 2012
HAYS REMAINS IN A FAVORABLE ENVIRONMENT FOR ONGOING CONVECTION
FOR THE NEXT FEW HOURS BASED ON 05Z ONGOING CONVECTION, TRACK OF
THE UPPER TROUGH FROM WATER VAPOR LOOP, RAP 400MB POTENTIAL
VORTICITY AND RAP MUCAPES NORTH OF THE SURFACE FRONT. THIS AREA
WILL SHIFT EAST BY 08Z AND THE SURFACE BOUNDARY WILL MOVE FURTHER
SOUTH INTO OKLAHOMA. BEHIND THIS FRONT NORTH/NORTHEAST WINDS AT
AROUND 10KTS CAN BE EXPECTED THROUGH WEDNESDAY EVENING ACROSS ALL
OF WESTERN KANSAS. VFR CIGS ARE EXPECTED BASED ON 00Z NAM MODEL
SOUNDINGS. A FEW SPRINKLE WILL BE POSSIBLE ON EARLY WEDNESDAY AS A
SUBTLE DISTURBANCE CROSSES SOUTHWEST KANSAS BUT AT THIS TIME WILL
NOT INCLUDE MENTION OF PRECIPITATION AT ANY TAF SITES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 80 60 76 61 / 30 50 50 40
GCK 79 56 75 59 / 40 40 40 40
EHA 82 55 76 58 / 40 40 40 30
LBL 83 58 77 60 / 30 50 40 40
HYS 79 57 74 59 / 30 40 40 40
P28 83 63 78 62 / 30 50 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...BURKE
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
150 AM CDT WED SEP 26 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1214 AM CDT WED SEP 26 2012
AT 00Z WEDNESDAY A 500MB LOW WAS LOCATED JUST NORTH OF THE FOUR
CORNERS REGION WITH A 250MB 55KT JET STREAK LOCATED ON ITS WEST
SIDE DIVING SOUTH ACROSS WESTERN NEVADA. ANOTHER 50KT JET WAS
LOCATED IN THE BASED ON THIS UPPER LOW/TROUGH OVER NORTHERN
NEVADA. FURTHER EAST ACROSS THE SOUTHWEST KANSAS THE WATER VAPOR
LOOP AND RAP 400MB POTENTIAL VORTICITY PLACES INDICATED AN UPPER
LEVEL TROUGH MOVING EAST FROM SOUTHEAST COLORADO INTO SOUTHWEST
KANSAS. CLOUD TOPS WERE COOLING AHEAD OF THIS FEATURE FROM 00Z-
02Z. A 700MB BAROCLINIC ZONE WAS ALSO LOCATED IN THIS AREA AT 00Z
AND AT THE 850MB LEVEL WARM AIR ADVECTION WAS LOCATED ALONG AND
NORTH OF A SURFACE BOUNDARY WHICH WAS LOCATED FROM THE PANHANDLE
OF OKLAHOMA ACROSS SOUTH CENTRAL KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 147 AM CDT WED SEP 26 2012
SATELLITE LOOP INDICATING SKIES ATTEMPTING TO CLEAR BEHIND THE
FIRST UPPER LEVEL TROUGH THAT WAS CROSSING SOUTHWEST KANSAS
EARLIER THIS MORNING. THIS FIRST WAVE WAS REFLECTED WELL BY THE
WATER VAPOR LOOP AND RAP 400MB POTENTIAL VORTICITY. AS THIS SYSTEM
EXITS WESTERN KANSAS THE PRECIPITATION CHANCES WILL DROP WITH THE
POSSIBLE EXCEPTION OF NORTH CENTRAL KANSAS AS ANOTHER WEAKER WAVE
CROSSES SOUTHWEST KANSAS EARLY WEDNESDAY MORNING. WILL MONITOR
TREND AND INSERT A PERIOD OF EARLY MORNING CLOUDS AND POSSIBLE
LIGHT RAINSHOWERS/SPRINKLES AS NEEDED.
THE NEXT DECENT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE
TODAY AND ESPECIALLY OVERNIGHT AS THE UPPER LEVEL JET THAT WAS
LOCATED OVER NEVADA ROTATES AROUND THE 500MB LOW AND APPROACHES
THE AREA. NAM AND GFS WERE IN DECENT AGREEMENT PLACING SOUTHWEST
KANSAS NEAR THE LEFT EXIT REGION OF THE UPPER JET LATE TODAY WITH
IMPROVING 850-700MB MOISTURE AND FRONTOGENESIS DEVELOPING NORTH OF
THE COLD FRONT. 00Z NAM AND 00Z GFS DO HOWEVER DIFFER SLIGHTLY ON
THE LOCATION THE BETTER FRONTOGENESIS BUT THE GENERAL TREND IS
CONVECTION CHANCES IMPROVING FROM WEST TO EAST LATE TODAY ACROSS
WESTERN KANSAS.
BETTER 0-6KM SHEAR EXPECTED BY LATE DAY BASED ON THE 00Z NAM WITH
VALUES OF AROUND 40 KNOTS. CAPE VALUES WILL ACROSS WESTERN KANSAS
ARE EXPECTED TO BE AROUND 1000J/KG. GIVEN THIS AND SOME LATE DAY
FORCING DEVELOPING WILL KEEP A MENTION OF SEVERE STORMS GOING IN
THE HAZARDOUS WEATHER OUTLOOK. MAIN HAZARD APPEARS TO BE HAIL.
AS FOR TEMPERATURES...THE OVERNIGHT RAINFALL AND EXPECTED CLOUD
COVER LATER TODAY SHOULD LIMIT THE WARM UP THIS AFTERNOON. AT THIS
TIME WILL TREND TOWARDS THE COOLER GUIDANCE WHICH SUPPORTS THE
850MB MIX DOWN TEMPERATURES FROM THE NAM AND GFS ALONG WITH WHAT
THE PREVIOUS SHIFT SUGGESTED. WILL ALSO NOT DEVIATE FAR FROM THE
LOWS TONIGHT GIVEN THE MID 50S TO NEAR 60 DEWPOINTS FORECAST NORTH
OF THE FRONT ACROSS SOUTHWEST KANSAS AND EXPECTED CLOUD COVER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 309 PM CDT TUE SEP 25 2012
THURSDAY WILL START WITH A BROAD UPPER LEVEL WAVE PASSING THROUGH
WESTERN KANSAS, ALONG WITH A NEARLY STATIONARY FRONT LAYING ACROSS
OUR CWA. THEREFORE, POPS WILL BE IN THE 30 PERCENT RANGE WEST TO
THE 50 PERCENT RANGE IN OUR SOUTHEASTERN CWA. THERE WILL BE A
BLANKET OF LOWER TO MID CLOUDS OVERHEAD WITH LITTLE INSOLATION.
HIGHS SHOULD ONLY REACH THE MID TO UPPER 70S, AND RAINFALL WILL
LIKELY VARY FROM .02 TO .40 INCH. THURSDAY NIGHT AND FRIDAY WILL
BE VERY SIMILAR WITH THE UPPER WAVE STRETCHING ACROSS WESTERN AND
CENTRAL KANSAS, AND THE AFOREMENTIONED FRONT WILL BE MEANDERING
NORTH AND THEN SOUTH OVER OUR FORECAST AREA. PRECIPITATION CHANCES
WILL STILL BE IN THE 25 TO 50 PERCENT RANGE, HIGHEST IN THE EAST
WHERE DEWPOINTS WILL BE HIGHEST IN THE 60 TO 63 DEGREE RANGE. QPF
WILL BE A LITTLE HIGHER IN THE EASTERN ZONES THAN IN THE WEST, DUE
TO HIGHER MOISTURE CONTENT. THE AXIS OF THE UPPER WAVE SHOULD
CROSS TO THE EAST OF US BY SATURDAY, BUT THE FRONT WILL STILL BE
IN THE AREA. SO POPS WILL FALL INTO THE 20 TO 30 PERCENT RANGE
SATURDAY MORNING, AND THEN TO THE 20 PERCENT OR LESS RANGE
SATURDAY AFTERNOON. BUT, JUST AS THAT ONE WAVE IS LEAVING OUR
AREA, ANOTHER RIPPLE WILL COME THROUGH SATURDAY NIGHT, RESULTING
IN 20 PERCENT POPS SATURDAY NIGHT IN OUR WEST, THEN SHIFTING TO 20
PERCENT POPS IN OUR EAST SUNDAY. THE LARGE SYNOPTIC SCALE LOW WILL
STAY ANCHORED OVER THE COAST OFF BAJA CALIFORNIA THROUGH THE 7 DAY
PERIOD, THEN GET INGESTED INTO AN EVEN LARGER SCALE UPPER LOW
ENTERING THE NORTHWESTERN U.S. BY NEXT WEDNESDAY, OCTOBER 3RD. BY
SUNDAY, I THINK HIGH PRESSURE WILL BE BUILDING IN AT THE H5 AND H7
LEVELS MONDAY INTO TUESDAY, BRINGING AN END TO PRECIPITATION
CHANCES. THEREFORE, MONDAY INTO TUESDAY, DAYS 6 AND 7, WILL SEE AN
END TO PRECIPITATION AND A LOT MORE SUNSHINE AS WELL AS A WARM UP.
MAXIMUM TEMPERATURES FRIDAY AND SATURDAY WILL BE COOL AND GENERALLY
IN THE LOW 70S NORTH TO THE MID 70S SOUTHEAST. MINIMUM TEMPERATURES
FRIDAY IN THE UPPER 50S TO LOWER 60S WILL COOL TO MONDAY MORNING
READINGS RANGING FROM AROUND 50 DEGREES IN THE SYRACUSE TO
WAKEENEY AREA, TO NEAR 54 DEGREES IN THE COLDWATER AND MEDICINE
LODGE AREAS. SUNDAY`S MAX TEMPS WILL WARM TO THE MID TO UPPER 70S,
THEN ON MONDAY TO THE UPPER 70S TO CLOSE TO 80 DEGREES, AND BY
TUESDAY CLIMB TO THE UPPER 70S TO LOWER 80S. MINIMUM TEMPERATURES
WILL WARM A LITTLE BY TUESDAY MORNING TO THE MID 50S IN MOST
LOCATIONS.
OVERALL, THE ECMWF MODEL AND THE GEM ARE IN GOOD AGREEMENT OUT TO
ABOUT 132HRS, OR 30/12Z AND WERE LEANED TOWARD MORE THAN THE GFS.
THE GFS MODEL IS FASTER WITH EXITING THE FIRST UPPER WAVE, WHILE THE
ECMWF AND GEM BOTH DRAG THIS UPPER FEATURE THROUGH THE PLAINS
WEDNESDAY THROUGH SATURDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1214 AM CDT WED SEP 26 2012
HAYS REMAINS IN A FAVORABLE ENVIRONMENT FOR ONGOING CONVECTION
FOR THE NEXT FEW HOURS BASED ON 05Z ONGOING CONVECTION, TRACK OF
THE UPPER TROUGH FROM WATER VAPOR LOOP, RAP 400MB POTENTIAL
VORTICITY AND RAP MUCAPES NORTH OF THE SURFACE FRONT. THIS AREA
WILL SHIFT EAST BY 08Z AND THE SURFACE BOUNDARY WILL MOVE FURTHER
SOUTH INTO OKLAHOMA. BEHIND THIS FRONT NORTH/NORTHEAST WINDS AT
AROUND 10KTS CAN BE EXPECTED THROUGH WEDNESDAY EVENING ACROSS ALL
OF WESTERN KANSAS. VFR CIGS ARE EXPECTED BASED ON 00Z NAM MODEL
SOUNDINGS. A FEW SPRINKLE WILL BE POSSIBLE ON EARLY WEDNESDAY AS A
SUBTLE DISTURBANCE CROSSES SOUTHWEST KANSAS BUT AT THIS TIME WILL
NOT INCLUDE MENTION OF PRECIPITATION AT ANY TAF SITES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 80 60 76 61 / 30 50 50 40
GCK 79 56 75 59 / 40 40 40 40
EHA 82 55 76 58 / 40 40 40 30
LBL 83 58 77 60 / 30 50 40 40
HYS 79 57 74 59 / 30 40 40 40
P28 83 63 78 62 / 30 50 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...BURKE
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1220 AM CDT WED SEP 26 2012
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1214 AM CDT WED SEP 26 2012
AT 00Z WEDNESDAY A 500MB LOW WAS LOCATED JUST NORTH OF THE FOUR
CORNERS REGION WITH A 250MB 55KT JET STREAK LOCATED ON ITS WEST
SIDE DIVING SOUTH ACROSS WESTERN NEVADA. ANOTHER 50KT JET WAS
LOCATED IN THE BASED ON THIS UPPER LOW/TROUGH OVER NORTHERN
NEVADA. FURTHER EAST ACROSS THE SOUTHWEST KANSAS THE WATER VAPOR
LOOP AND RAP 400MB POTENTIAL VORTICITY PLACES INDICATED AN UPPER
LEVEL TROUGH MOVING EAST FROM SOUTHEAST COLORADO INTO SOUTHWEST
KANSAS. CLOUD TOPS WERE COOLING AHEAD OF THIS FEATURE FROM 00Z-
02Z. A 700MB BAROCLINIC ZONE WAS ALSO LOCATED IN THIS AREA AT 00Z
AND AT THE 850MB LEVEL WARM AIR ADVECTION WAS LOCATED ALONG AND
NORTH OF A SURFACE BOUNDARY WHICH WAS LOCATED FROM THE PANHANDLE
OF OKLAHOMA ACROSS SOUTH CENTRAL KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 309 PM CDT TUE SEP 25 2012
THE MAIN FORECAST CHALLENGES ARE THUNDERSTORMS CHANCES TONIGHT INTO
WEDNESDAY.
AN UPPER LEVEL LOW AND ASSOCIATED UPPER LEVEL SHORTWAVE TROUGH WILL
MOVE VERY SLOWLY INTO THE 4 CORNERS REGION INTO WEDNESDAY. WEAK
DISTURBANCES ALOFT AHEAD OF THIS SYSTEM WILL MOVE ACROSS WESTERN
KANSAS TONIGHT WITH ANOTHER ON WEDNESDAY AFTERNOON. SOME UPWARD
VERTICAL MOTION ASSOCIATED WITH THESE DISTURBANCES ALONG WITH
ELEVATED MOISTURE AND CAPE COULD SUPPORT A FEW THUNDERSTORMS AND
SHOWERS TONIGHT INTO WEDNESDAY. THE BEST CHANCES WILL BE TONIGHT IN
THE EAST PART OF THE FA FROM SAINT JOHN TO MEDICINE LODGE NEAR AND
ALONG A FRONTAL BOUNDARY. SOME OF THE STORMS IN BARBER COUNTY
WITH THE HIGHEST CAPE FIELDS, MOISTURE CONVERGENCE, ISENTROPIC
LIFT, AND FRONTOGENETICAL FORCING, COULD BE SEVERE WITH HAIL UP TO
QUARTER SIZE AND WINDS OF 50 TO 60 MPH FROM LATE THIS AFTERNOON
INTO EARLY EVENING. SKIES WILL BECOME MOSTLY CLOUDY INTO WEDNESDAY
WITH THE UPPER LEVEL DISTURBANCES AND MID TO UPPER LEVEL MOISTURE.
A COLD FRONT WILL MOVE FROM NEAR THE OKLAHOMA AND KANSAS BORDER
TONIGHT AND INTO THE TEXAS PANHANDLE AND OKLAHOMA ON WEDNESDAY AS
COOLER HIGH PRESSURE SINKS INTO THE CENTRAL PLAINS.
FOR TONIGHT EXPECT INCREASING CLOUDINESS WITH LIGHT EAST WINDS
BECOMING LIGHT NORTHERLY. OVERNIGHT LOWS WILL RANGE FROM THE MID 50S
ACROSS MUCH OF SOUTHWEST KANSAS, TO THE MID 50S TO LOWER 60S IN PARTS
OF SOUTH CENTRAL KANSAS. ON WEDNESDAY HIGH TEMPERATURES WILL RANGE
FROM THE UPPER 70S, EXPECT WARMER ALONG THE OKLAHOMA BORDER WITH LOW
80S. WINDS WILL BECOME LIGHT EASTERLY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 309 PM CDT TUE SEP 25 2012
THURSDAY WILL START WITH A BROAD UPPER LEVEL WAVE PASSING THROUGH
WESTERN KANSAS, ALONG WITH A NEARLY STATIONARY FRONT LAYING ACROSS
OUR CWA. THEREFORE, POPS WILL BE IN THE 30 PERCENT RANGE WEST TO
THE 50 PERCENT RANGE IN OUR SOUTHEASTERN CWA. THERE WILL BE A
BLANKET OF LOWER TO MID CLOUDS OVERHEAD WITH LITTLE INSOLATION.
HIGHS SHOULD ONLY REACH THE MID TO UPPER 70S, AND RAINFALL WILL
LIKELY VARY FROM .02 TO .40 INCH. THURSDAY NIGHT AND FRIDAY WILL
BE VERY SIMILAR WITH THE UPPER WAVE STRETCHING ACROSS WESTERN AND
CENTRAL KANSAS, AND THE AFOREMENTIONED FRONT WILL BE MEANDERING
NORTH AND THEN SOUTH OVER OUR FORECAST AREA. PRECIPITATION CHANCES
WILL STILL BE IN THE 25 TO 50 PERCENT RANGE, HIGHEST IN THE EAST
WHERE DEWPOINTS WILL BE HIGHEST IN THE 60 TO 63 DEGREE RANGE. QPF
WILL BE A LITTLE HIGHER IN THE EASTERN ZONES THAN IN THE WEST, DUE
TO HIGHER MOISTURE CONTENT. THE AXIS OF THE UPPER WAVE SHOULD
CROSS TO THE EAST OF US BY SATURDAY, BUT THE FRONT WILL STILL BE
IN THE AREA. SO POPS WILL FALL INTO THE 20 TO 30 PERCENT RANGE
SATURDAY MORNING, AND THEN TO THE 20 PERCENT OR LESS RANGE
SATURDAY AFTERNOON. BUT, JUST AS THAT ONE WAVE IS LEAVING OUR
AREA, ANOTHER RIPPLE WILL COME THROUGH SATURDAY NIGHT, RESULTING
IN 20 PERCENT POPS SATURDAY NIGHT IN OUR WEST, THEN SHIFTING TO 20
PERCENT POPS IN OUR EAST SUNDAY. THE LARGE SYNOPTIC SCALE LOW WILL
STAY ANCHORED OVER THE COAST OFF BAJA CALIFORNIA THROUGH THE 7 DAY
PERIOD, THEN GET INGESTED INTO AN EVEN LARGER SCALE UPPER LOW
ENTERING THE NORTHWESTERN U.S. BY NEXT WEDNESDAY, OCTOBER 3RD. BY
SUNDAY, I THINK HIGH PRESSURE WILL BE BUILDING IN AT THE H5 AND H7
LEVELS MONDAY INTO TUESDAY, BRINGING AN END TO PRECIPITATION
CHANCES. THEREFORE, MONDAY INTO TUESDAY, DAYS 6 AND 7, WILL SEE AN
END TO PRECIPITATION AND A LOT MORE SUNSHINE AS WELL AS A WARM UP.
MAXIMUM TEMPERATURES FRIDAY AND SATURDAY WILL BE COOL AND GENERALLY
IN THE LOW 70S NORTH TO THE MID 70S SOUTHEAST. MINIMUM TEMPERATURES
FRIDAY IN THE UPPER 50S TO LOWER 60S WILL COOL TO MONDAY MORNING
READINGS RANGING FROM AROUND 50 DEGREES IN THE SYRACUSE TO
WAKEENEY AREA, TO NEAR 54 DEGREES IN THE COLDWATER AND MEDICINE
LODGE AREAS. SUNDAY`S MAX TEMPS WILL WARM TO THE MID TO UPPER 70S,
THEN ON MONDAY TO THE UPPER 70S TO CLOSE TO 80 DEGREES, AND BY
TUESDAY CLIMB TO THE UPPER 70S TO LOWER 80S. MINIMUM TEMPERATURES
WILL WARM A LITTLE BY TUESDAY MORNING TO THE MID 50S IN MOST
LOCATIONS.
OVERALL, THE ECMWF MODEL AND THE GEM ARE IN GOOD AGREEMENT OUT TO
ABOUT 132HRS, OR 30/12Z AND WERE LEANED TOWARD MORE THAN THE GFS.
THE GFS MODEL IS FASTER WITH EXITING THE FIRST UPPER WAVE, WHILE THE
ECMWF AND GEM BOTH DRAG THIS UPPER FEATURE THROUGH THE PLAINS
WEDNESDAY THROUGH SATURDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1214 AM CDT WED SEP 26 2012
HAYS REMAINS IN A FAVORABLE ENVIRONMENT FOR ONGOING CONVECTION
FOR THE NEXT FEW HOURS BASED ON 05Z ONGOING CONVECTION, TRACK OF
THE UPPER TROUGH FROM WATER VAPOR LOOP, RAP 400MB POTENTIAL
VORTICITY AND RAP MUCAPES NORTH OF THE SURFACE FRONT. THIS AREA
WILL SHIFT EAST BY 08Z AND THE SURFACE BOUNDARY WILL MOVE FURTHER
SOUTH INTO OKLAHOMA. BEHIND THIS FRONT NORTH/NORTHEAST WINDS AT
AROUND 10KTS CAN BE EXPECTED THROUGH WEDNESDAY EVENING ACROSS ALL
OF WESTERN KANSAS. VFR CIGS ARE EXPECTED BASED ON 00Z NAM MODEL
SOUNDINGS. A FEW SPRINKLE WILL BE POSSIBLE ON EARLY WEDNESDAY AS A
SUBTLE DISTURBANCE CROSSES SOUTHWEST KANSAS BUT AT THIS TIME WILL
NOT INCLUDE MENTION OF PRECIPITATION AT ANY TAF SITES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 60 76 61 73 / 50 50 40 40
GCK 56 75 59 71 / 40 40 40 30
EHA 55 76 58 74 / 40 40 30 30
LBL 58 77 60 73 / 50 40 40 40
HYS 57 74 59 71 / 40 40 40 40
P28 63 78 62 75 / 50 50 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...KRUSE
LONG TERM...BURKE
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1211 AM CDT WED SEP 26 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT TERM - THROUGH WEDNESDAY...
SURFACE ANALYSIS AT 18Z INDICATED THAT A RATHER WELL DEFINED SURFACE
LOW OVER FAR SOUTH CENTRAL KANSAS AND NORTH CENTRAL OKLAHOMA...NEAR
THE BORDER OF THE TWO STATES. A SURFACE BOUNDARY...WHICH IS A
REMNANT OF THE BOUNDARY WHICH CAUSED OVERNIGHT SHOWERS IN EASTERN
KANSAS AND WESTERN MISSOURI...IS CURRENTLY LOCATED GENERALLY ACROSS
SOUTHEASTERN KANSAS AND MORE SPECIFICALLY ALONG A LINE ROUGHLY FROM
GARNETT KS TO WELLINGTON KS. THIS BOUNDARY WILL LIKELY BE THE FOCUS
FOR SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON INTO THIS
EVENING. CURRENT SURFACE WINDS NORTH AND WEST OF THE BOUNDARY ARE
OUT OF THE E-NE...WHILE WINDS TO THE SOUTH AND EAST OF THE BOUNDARY
ARE MORE FROM THE SW. THESE PARALLEL AND OPPOSING WINDS ARE NOT
CREATING ENOUGH CONVERGENCE AT THE MOMENT TO GET LOW LEVEL UPWARD
MOTION. HOWEVER AS THE LOW SLIDES EASTWARD SURFACE WINDS MAY BACK A
LITTLE IN RESPONSE TO THE LOWS MOVEMENT. MODEL FORECAST SOUNDINGS
FOR SOUTHEAST KANSAS INDICATE THAT A STOUT LOW/MID LEVEL WARM NOSE
WILL REMAIN ESTABLISHED THROUGH ABOUT 22Z. AT THAT TIME CONVECTION
MAY OCCUR ALONG AND NEAR THAT BOUNDARY. FURTHER ENHANCING CONVECTION
POTENTIAL IS DECENT 850 MB CONVERGENCE AS SW 850 MB WINDS AT 20 TO
30 KTS NOSE INTO SLIGHTLY SLOWER 850 MB WINDS ACROSS EAST CENTRAL
KANSAS. MID/UPPER SUPPORT FOR ASCENT SHOULD COME LATER ON TONIGHT AS
A QUICKLY MOVING SHORTWAVE TROUGH CRUISES THROUGH THE AREA. THE
COMBINATION OF THE AFOREMENTIONED FACTORS SHOULD LEAD TO SCATTERED
CONVECTION ACROSS PARTS OF EAST CENTRAL AND SOUTHEAST KANSAS. AS
SURFACE WINDS BECOME MORE BACKED THE BOUNDARY MAY ALSO SHIFT
NORTHWARD...CAUSING AREAS ALONG AND SOUTH OF THE KANSAS TURNPIKE TO
HAVE A CHANCE FOR SOME SHOWERS AND THUNDERSTORMS. RAP MESOANALYSIS
AT 18Z SHOWS THAT AROUND 2500 J/KG OF MLCAPE EXISTS ALONG AND SOUTH
OF THAT BOUNDARY INDICATING THAT ANY UPDRAFT THAT IS ABLE TO GET
GOING WILL HAVE QUITE A BIT OF INSTABILITY TO WORK WITH. UPDRAFTS
WILL ALSO HAVE AROUND 20 KTS OF DEEP SHEAR TO WORK WITH...SO SOME
UPDRAFT PERSISTENCE WILL BE POSSIBLE. THE STRONGER CONVECTIVE CELLS
WILL HAVE THE CAPABILITY TO POTENTIALLY PRODUCE SOME LARGE
HAIL...PERHAPS UP TO QUARTER SIZED. CLOUD BASES MAY BE IN THE 5 KFT
TO 6 KFT RANGE WITH GOOD LOW LEVEL LAPSE RATES AND DRY AIR BELOW THE
CLOUD LAYER...SO STRONG GUSTY WINDS WILL ALSO BE POSSIBLE WITH THE
STRONGEST UPDRAFTS. ALTHOUGH A FEW STORMS ARE EXPECTED TO BE STRONG
THIS AFTERNOON WIDESPREAD SEVERE WEATHER IS NOT EXPECTED...WITH THE
MAIN THREAT AREA EXPECTED TO BE ALONG AND SOUTH OF THE KANSAS
TURNPIKE.
WITH THE BOUNDARY REMAINING NEAR THE FORECAST AREA THROUGH THE NIGHT
PERIODS OF MODERATE TO HEAVY RAIN WILL BE POSSIBLE ACROSS AREAS OF
EAST CENTRAL AND SOUTHEASTERN KANSAS. A FEW SHOWERS WILL ALSO BE
POSSIBLE ON WEDNESDAY AS A CONTINUATION OF TUESDAY NIGHTS SHOWERS
AND THUNDERSTORMS. EXPECT THERE TO BE A RATHER TIGHT GRADIENT
BETWEEN THE HIGHER END POPS SOUTH OF INTERSTATE 70 AND AREAS TO THE
NORTH NEAR THE KS/NE BORDER...WITH THE HIGHEST POPS REMAINING IN
EAST CENTRAL AND SOUTHEAST KANSAS.
JL
MID TERM - WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...
THE UNSETTLED WEATHER PATTERN WILL CONTINUE THROUGH THIS PERIOD AS
THE STATIONARY FRONTAL BOUNDARY IS FORECAST TO REMAIN IN THE
AREA...ALTHOUGH PRECIP CHANCES WILL VARY A BIT BASED ON TIMING OF
MID LEVEL SHORT WAVE TROUGHS AND MINOR NORTH TO SOUTH FLUCTUATIONS
IN THE LOCATION OF THE FRONT. THE EXACT TIMING OF THE WEAK TROUGHS
AND ASSOCIATED ENHANCEMENTS IN PRECIPITATION COVERAGE REMAINS
RATHER DIFFICULT TO PIN POINT AT THIS TIME...BUT IT CURRENTLY
LOOKS LIKE WEDNESDAY EVENING AND THURSDAY NIGHT-FRIDAY MORNING
WILL HAVE THE BEST CHANCES FOR MORE WIDESPREAD PRECIP ACROSS THE
AREA. EVEN THEN...THE RAIN CHANCES WILL INCREASE FROM NORTH TO
SOUTH ACROSS THE AREA AS THERE IS MORE CONFIDENCE IN THE FRONT
SETTING UP SOUTH OF THE AREA THAN IN A NORTHWARD SHIFT. THE SHORT
WAVE SCHEDULED FOR THURSDAY NIGHT INTO FRIDAY MORNING SHOULD BE
STRONG ENOUGH TO PUSH THE FRONT FARTHER TO THE SOUTH AND BRING IN
DRIER AIR FROM THE NORTH. THIS SHOULD EFFECTIVELY CUT OFF THE
PRECIP CHANCES FROM NORTH TO SOUTH LATE FRIDAY INTO FRIDAY NIGHT.
THE POTENTIAL FOR ISOLATED STRONG STORMS AND ISOLATED HEAVY
RAINFALL AMOUNTS WILL CONTINUE THROUGH THE MAJORITY OF THIS
PERIOD. SEVERE POTENTIAL WILL DECREASE WITH TIME AS INSTABILITY
GRADUALLY WANES WITH WEAKER LAPSE RATES ALOFT. HOWEVER...DEEP
LAYER SHEAR WILL INCREASE A BIT WITH SOME LOCAL MAXIMA IN
INSTABILITY WHICH MAY PRESENT SOME LOCALIZED STRONG TO SEVERE
STORM POTENTIAL. THE HEAVY RAIN POTENTIAL IS A RESULT OF PWAT
VALUES INCREASING TO 1.5 INCHES OR HIGHER...CLIMATOLOGICALLY
HIGH... THE PRESENCE OF WIDESPREAD WEAK TO MODERATE INSTABILITY...
AND STORM MOTIONS THAT MAY OCCASIONALLY SUPPORT TRAINING ALONG OR
NEAR THE FRONTAL BOUNDARY. EVEN WITH HEAVY RAIN POTENTIAL...
FLOODING POTENTIAL APPEARS QUITE LOW GIVEN THE SOIL CONDITIONS...
STREAM BASE FLOW LEVELS...AND AVAILABLE WATER STORAGE IN AREA
LAKES AND PONDS.
HIGHS IN THE 70S ARE EXPECTED ONCE AGAIN THURSDAY AND FRIDAY WITH
AMPLE CLOUD COVER IN PLACE. THE CLOUDS WILL ALSO LIMIT THE DIURNAL
TEMPERATURE SWING SO LOWS SHOULD ONLY DROP INTO THE MIDDLE 50S TO
LOWER 60S.
BARJENBRUCH
LONG TERM - SATURDAY THROUGH TUESDAY...
A RATHER DEEP UPPER TROUGH SETTLES SOUTH INTO THE OHIO VALLEY ON
SATURDAY WITH NORTHERLY FLOW ALOFT AND DRY HIGH PRESSURE AT THE
SURFACE. WHILE THE LONG TERM MODEL GUIDANCE DIFFERS SOMEWHAT IN
OVERALL FLOW SOLUTIONS...THE EXPECTED RESULT IS THE SAME AND A
PERIOD OF DRY STABLE CONDITIONS IS EXPECTED FROM SATURDAY THROUGH
THE END OF THE FORECAST PERIOD ON TUESDAY. THERE ARE SOME
INDICATIONS OF A RATHER PERSISTENT BAND OF FRONTOGENESIS AND
ISENTROPIC ASCENT IN CENTRAL TO WESTERN KANSAS ON THE WESTERN
FLANK OF THE SURFACE HIGH BY LATE IN THE WEEKEND...BUT THIS LOOKS
LIKE A SET UP FOR SPRINKLES AT BEST AND HAVE NOT BROUGHT PRECIP
CHANCES INTO THE FORECAST AT THIS TIME. EXPECT TEMPERATURES
TOPPING OUT IN THE 70S WITH LOWS AROUND 50 ESSENTIALLY EVERY DAY
DURING THIS PERIOD OWING TO NEARLY NEUTRAL TEMPERATURE ADVECTION.
THE OCCASIONAL PRESENCE OF CLOUDS VERSUS CLEAR AND CALM CONDITIONS
OVERNIGHT COULD IMPACT LOWS...BUT THERE IS NO CLEAR SIGNAL AT THIS
TIME POINTING TO ANY NIGHTS BEING PARTICULARLY CLEAR AND COLD.
BARJENBRUCH
&&
.AVIATION...
LOW LEVEL JET CONTINUES TO DEVELOP CONVECTION ACROSS EAST CENTRAL
KANSAS...BUT QUESTIONS REMAIN ON HOW FAR NORTH THE MCS WILL
DEVELOP OVER THE NEXT FEW HOURS. HAVE THEREFORE ONLY KEPT AN MVFR
TEMPO GROUP IN THUNDERSTORMS UNTIL 07Z...BUT EXPECT THE MCS TO
THEN SHIFT MORE EAST THAN NORTHWARD AND WILL END THE VCTS GROUP AT
08-10Z...THEN DRY ACROSS THE TERMINALS THE REMAINDER OF THE FCST
WITH ONLY SCT-BKN MID AND HIGH LEVEL AC. LIGHT VRB WINDS NEAR
CONVECTION WILL THEN PREVAIL FROM THE EAST AFT 09Z AT LESS THAN 10
KTS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
144 AM EDT WED SEP 26 2012
...Updated Aviation Discussion...
.Forecast Update...
Updated at 1215 AM EDT Wed Sep 26 2012
Complex of storms moving east through southern Indiana and northern
Kentucky continues to weaken as it moves into a less favorable
environment. Had mostly sub-severe hail reported this evening as a
stable layer at the sfc prevented severe winds aloft from mixing
down. Had max wind reports of 30-40 mph. Expect convection to
remain elevated through the early morning hours but we will see some
moderate to at times heavy rains over southern Indiana with multiple
waves causing a line of showers/t-storms all the way back through
KS/OK. Thus, will continue to monitor for may some small hail
overnight, but the main threat will be flooding issues. Have
already issued a flood advisory for portions of Dubois, Orange,
Washington, and Clark Counties in Indiana due to training storms
that occurred earlier this evening.
Tweaked 60% POPs a little farther south with this update to better
line up with this complex. Updated products out shortly.
&&
.Short Term (This afternoon through Wednesday Night)...
Issued at 331 PM EDT Tue Sep 25 2012
Morning convective complex continues to head eastward through the
coal fields of eastern Kentucky this afternoon. Satellite and
surface observations reveal clearing skies to the west of our area.
Areas west of I-65 have already cleared out and temperatures are on
the way up. Further east, mid-high level cloud debris remain, but
some clearing is expected to occur by late afternoon and early
evening in those areas. Dry conditions are expected for the
remainder of the afternoon as the atmosphere recovers from this
morning`s storminess. Temperatures will increase this afternoon as
the sun comes back out, but we will not have much time to work with
to get readings all that high. Still think that we`ll see maximum
temperature readings in the mid-upper 70s in the far west with upper
60s-lower 70s in the central and mid-upper 60s in the east.
Later this afternoon and evening, the deterministic NCEP models all
agree on redeveloping convection along a frontal boundary draped to
our north/northwest. While the atmosphere over south-central
Indiana and much of north-central Kentucky has been convectively
overturned, the atmosphere across western/southwestern Kentucky has
largely been undisturbed. High resolution model runs from the
LMK-WRF, SPC WRF, the RAP, and the HRRR all show increasing
instability across southern IL, eastern MO, and western Kentucky
this afternoon. Model proximity soundings generally show an
elevated mixed layer atop a fairly moist near-surface layer. Wind
fields are sheared in both speed and direction and strong lapse
rates aloft should promote vigorous convective development along
and ahead of this front. Severe convection is likely to our west
this evening and tonight, but is highly questionable across the LMK
forecast area due to this morning`s convection.
Current thinking is that we`ll see a line of convection develop to
our northwest this evening and then slide toward the Ohio River
later tonight. As this line encounters our worked over airmass,
we`ll likely see the convection continue, since the wind shear is
fairly decent and we`ll have instability aloft. The near surface
environment looks to remain largely stable, so any storms that we
see would likely result in torrential rains, some hail and quite a
bit of cloud to ground lightning. The remnants of this line may
transverse southward into southern Kentucky late tonight, but
instability and wind shear support may decay before the line gets
that far south. Therefore, the highest chances of precipitation
look to be across southern Indiana and portions of northern Kentucky
with lesser chances as one heads southward toward the Tennessee
border. Lows tonight will be milder with readings only cooling into
the upper 50s to the lower 60s.
Slow moving frontal boundary will only drift southward during the
day on Wednesday and likely become quasi-stationary by Wednesday
afternoon. Multiple mid-level impulses will transverse the region
resulting in multiple clusters of convection moving across the
region. In general, the highest probabilities of precipitation for
Wednesday favor southern Indiana and northern Kentucky with lesser
probabilities as one gets down toward the KY/TN border. Overall
convective evolution is very uncertain given the complex mesoscale
processes involved and where boundaries may lay. It is likely that
one or more MCS`s may develop and propagate eastward during the day
and into the evening hours. Severe threat is there with damaging
winds and large hail being the most likely threats. Temperatures
will be tricky, but we have stuck close to the weighted-model
average which results in upper 70s to the lower 80s in the north
with lower 80s across the south. The latest datasets do show some
forecast convergence on a wave approaching the area tomorrow evening
which results in increasing PoP chances for Wednesday night with
this forecast issuance. Lows Wednesday night will be in the 60s.
.Long Term (Thursday through Tuesday)...
Issued at 300 PM EDT Tue Sep 25 2012
Thursday through Friday...
Quasi-stationary front will remain draped east to west across the
Ohio Valley, with a series of upper disturbances riding along it in
zonal flow. Expect intervals of showers and thunderstorms, but these
will be as hard to time as the individual disturbances, so forecast
confidence is quite low.
Path of least regret at this time is to carry chance POPs for most
of the period. As timing becomes more clear on any of the upper
impulses, the POP forecast may be better refined. Temps will run
near normal by day, and above normal by night with abundant cloud
cover. Still plenty of bust potential as any longer episodes of
precip could really limit the diurnal ranges.
Friday night through Tuesday...
Sharp upper trough will dig into eastern Canada and the Great Lakes,
and help to push the front farther south over the weekend. Precip
chances will be suppressed farther into south-central Kentucky
through Saturday night, and then south of the area Sunday into early
next week. Model consensus is coming together with each successive
run, so this is a higher-confidence forecast than Thu-Fri. More of a
polar air mass will knock temperatures slightly below normal, with
highs in the lower/mid 70s and lows in the lower/mid 50s.
&&
.Aviation (06Z TAF Issuance)...
Issued at 140 AM EDT Wed Sep 26 2012
With at least 3 MCVs lined up from southern Indiana to southern
Illinois, waves of convection will continue to affect SDF/LEX early
this morning. Looks like BWG should stay well south the line of
convection. Although the strongest convection has passed, SDF/LEX
can expect to see periodic t-storms with gusty winds up to 20-25kts
and moderate to heavy rainfall which may reduce vsbys briefly for
the next 2-4 hrs. Will monitor closely and add a tempo MVFR group
for vsby if a strong t-storm looks to impact a TAF site.
All TAF sites should see LLWS outside of any t-storms early this
morning due to a strong LLJ developing. Winds at 1.8 kft should be
220/40kts. LLWS should cease after sunrise as the LLJ decreases.
Sfc winds out of the SW may be a bit gusty this morning after
sunrise around 18-20kts according to Bufkit soundings.
The next convective wave should impact the area some time this
afternoon. The majority of hi-res models indicate that the TAF
sites would most likely be affected during the late
afternoon/evening hours with SDF/LEX having the best chances again.
Will include a VCSH at BWG since some models do indicate a little
more southward development.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS
Short Term.......MJ
Long Term........RAS
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1220 AM EDT WED SEP 26 2012
.Forecast Update...
Updated at 1215 AM EDT Wed Sep 26 2012
Complex of storms moving east through southern Indiana and northern
Kentucky continues to weaken as it moves into a less favorable
environment. Had mostly sub-severe hail reported this evening as a
stable layer at the sfc prevented severe winds aloft from mixing
down. Had max wind reports of 30-40 mph. Expect convection to
remain elevated through the early morning hours but we will see some
moderate to at times heavy rains over southern Indiana with multiple
waves causing a line of showers/t-storms all the way back through
KS/OK. Thus, will continue to monitor for may some small hail
overnight, but the main threat will be flooding issues. Have
already issued a flood advisory for portions of Dubois, Orange,
Washington, and Clark Counties in Indiana due to training storms
that occurred earlier this evening.
Tweaked 60% POPs a little farther south with this update to better
line up with this complex. Updated products out shortly.
&&
.Short Term (This afternoon through Wednesday Night)...
Issued at 331 PM EDT Tue Sep 25 2012
Morning convective complex continues to head eastward through the
coal fields of eastern Kentucky this afternoon. Satellite and
surface observations reveal clearing skies to the west of our area.
Areas west of I-65 have already cleared out and temperatures are on
the way up. Further east, mid-high level cloud debris remain, but
some clearing is expected to occur by late afternoon and early
evening in those areas. Dry conditions are expected for the
remainder of the afternoon as the atmosphere recovers from this
morning`s storminess. Temperatures will increase this afternoon as
the sun comes back out, but we will not have much time to work with
to get readings all that high. Still think that we`ll see maximum
temperature readings in the mid-upper 70s in the far west with upper
60s-lower 70s in the central and mid-upper 60s in the east.
Later this afternoon and evening, the deterministic NCEP models all
agree on redeveloping convection along a frontal boundary draped to
our north/northwest. While the atmosphere over south-central
Indiana and much of north-central Kentucky has been convectively
overturned, the atmosphere across western/southwestern Kentucky has
largely been undisturbed. High resolution model runs from the
LMK-WRF, SPC WRF, the RAP, and the HRRR all show increasing
instability across southern IL, eastern MO, and western Kentucky
this afternoon. Model proximity soundings generally show an
elevated mixed layer atop a fairly moist near-surface layer. Wind
fields are sheared in both speed and direction and strong lapse
rates aloft should promote vigorous convective development along
and ahead of this front. Severe convection is likely to our west
this evening and tonight, but is highly questionable across the LMK
forecast area due to this morning`s convection.
Current thinking is that we`ll see a line of convection develop to
our northwest this evening and then slide toward the Ohio River
later tonight. As this line encounters our worked over airmass,
we`ll likely see the convection continue, since the wind shear is
fairly decent and we`ll have instability aloft. The near surface
environment looks to remain largely stable, so any storms that we
see would likely result in torrential rains, some hail and quite a
bit of cloud to ground lightning. The remnants of this line may
transverse southward into southern Kentucky late tonight, but
instability and wind shear support may decay before the line gets
that far south. Therefore, the highest chances of precipitation
look to be across southern Indiana and portions of northern Kentucky
with lesser chances as one heads southward toward the Tennessee
border. Lows tonight will be milder with readings only cooling into
the upper 50s to the lower 60s.
Slow moving frontal boundary will only drift southward during the
day on Wednesday and likely become quasi-stationary by Wednesday
afternoon. Multiple mid-level impulses will transverse the region
resulting in multiple clusters of convection moving across the
region. In general, the highest probabilities of precipitation for
Wednesday favor southern Indiana and northern Kentucky with lesser
probabilities as one gets down toward the KY/TN border. Overall
convective evolution is very uncertain given the complex mesoscale
processes involved and where boundaries may lay. It is likely that
one or more MCS`s may develop and propagate eastward during the day
and into the evening hours. Severe threat is there with damaging
winds and large hail being the most likely threats. Temperatures
will be tricky, but we have stuck close to the weighted-model
average which results in upper 70s to the lower 80s in the north
with lower 80s across the south. The latest datasets do show some
forecast convergence on a wave approaching the area tomorrow evening
which results in increasing PoP chances for Wednesday night with
this forecast issuance. Lows Wednesday night will be in the 60s.
.Long Term (Thursday through Tuesday)...
Issued at 300 PM EDT Tue Sep 25 2012
Thursday through Friday...
Quasi-stationary front will remain draped east to west across the
Ohio Valley, with a series of upper disturbances riding along it in
zonal flow. Expect intervals of showers and thunderstorms, but these
will be as hard to time as the individual disturbances, so forecast
confidence is quite low.
Path of least regret at this time is to carry chance POPs for most
of the period. As timing becomes more clear on any of the upper
impulses, the POP forecast may be better refined. Temps will run
near normal by day, and above normal by night with abundant cloud
cover. Still plenty of bust potential as any longer episodes of
precip could really limit the diurnal ranges.
Friday night through Tuesday...
Sharp upper trough will dig into eastern Canada and the Great Lakes,
and help to push the front farther south over the weekend. Precip
chances will be suppressed farther into south-central Kentucky
through Saturday night, and then south of the area Sunday into early
next week. Model consensus is coming together with each successive
run, so this is a higher-confidence forecast than Thu-Fri. More of a
polar air mass will knock temperatures slightly below normal, with
highs in the lower/mid 70s and lows in the lower/mid 50s.
&&
.Aviation (00Z TAF Issuance)...
Issued at 650 PM EDT Tue Sep 25 2012
Showers and thunderstorms along a front in southern Indiana will
slowly sink south overnight. This activity has been very slow to
shift southward and have therefore pushed back the timing of VCTS at
SDF and LEX. This activity still looks like it will stay to the
north of BWG both tonight and through much of tomorrow. Will
therefore keep any mention of precipitation out of that TAF. There
will likely be a lull in the rain tomorrow morning until another
upper level disturbance crosses the area tomorrow afternoon,
bringing another round of showers and storms to SDF and LEX.
Winds will decrease to around 6-8 knots overnight out of the south
to southwest. A LLJ will strengthen towards midnight and pivot
across the area. Winds will increase to around 40 knots at 1800-2000
ft. Surface winds will once again increase and become gusty tomorrow.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS
Short Term.......MJ
Long Term........RAS
Aviation.........EER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
451 AM EDT WED SEP 26 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EDT WED SEP 26 2012
WV IMAGERY AND RUC ANALYSIS SHOWING UPPER TROUGH STRETCHING SW OVER
THE UPPER GREAT LKS FROM NRN QUEBEC. SHORTWAVE CURRENTLY ROTATING
THROUGH THE AXIS OF THE TROUGH OVER WRN LK SUPERIOR. AREA OF CLOUDS
ASSOCIATED WITH THIS SHORTWAVE HAVE BEEN STRUGGLING TO MOVE ACROSS
WRN LK SUPERIOR...BUT ARE FINALLY STARTING TO MOVE OVER LAND.
FARTHER EAST...A FEW AREAS OF LK ENHANCED RAIN SHOWERS HAVE BEEN
ONGOING OVER THE MAINLY NW FLOW ACROSS EASTERN LK SUPERIOR. THESE
HAVE BEEN DRIFTING MORE TO THE S OVER TIME AS 8Z KMQT VAD WIND
PROFILE SHOWING MORE NNW WINDS ALOFT. THESE SHOWERS LINE UP WELL
WITH MODEL INDICATED POCKET OF DEEPEST MOISTURE.
THE SHOWERS AND CLOUDS ASSOCIATED WITH THE SHORTWAVE WILL BE THE
MAIN CONCERNS FOR THE SHORT TERM PERIOD. EXPECT THE SHOWERS TO
CONTINUE TO SLIDE TO THE SSE UNDER THE NNW FLOW ALOFT THROUGH THE
MORNING HOURS AND LARGELY BE FOCUSED OVER NCNTRL UPPER MI. WITH THE
SHORTWAVE BRUSHING THE NE HALF OF THE CWA...COULD SEE AN INCREASE IN
INTENSITY FOR A WHILE THIS EARLY MORNING...BEFORE THE SHORTWAVE
QUICKLY DIVES SE OF THE CWA. AS THIS OCCURS...EXPECT THE MOISTURE TO
EXIT AND BRING AN END TO THE SHOWERS AS H500 HEIGHTS ARE ON THE
RISE. AS FOR CLOUDS...THERE SHOULD BE ENOUGH LLVL MOISTURE TO
PRODUCE A MOSTLY CLOUDY SKY NEAR LK SUPERIOR THIS MORNING AND THEN
SPREAD ACROSS MUCH OF THE REST OF THE CWA UNDER DIURNAL HEATING BY
MID DAY. THEN THE PREVIOUSLY MENTIONED DRYING WILL BEGIN TO TAKE
HOLD IN THE AFTN AND DIMINISH THE CLOUDS FROM NW TO SE ACROSS THE
CWA...WITH THE CLOUDS HOLDING ON THE LONGEST OVER ERN UPPER MI
/TOWARDS EARLY EVENING/. H850 TEMPS A DEGREE OR TWO COOLER TODAY
THAN YESTERDAY...SO EXPECT A SLIGHTLY COOLER DAY AND HIGHS IN THE
50S.
AS HAS BEEN DISCUSED OVER THE LAST SEVERAL SHIFTS...APPEARS TO BE A
GOOD FROST/FREEZE OVER MUCH OF UPPER MI TONIGHT. HIGH PRESSURE
CURRENTLY OVER SRN MANITOBA WILL SLIDE OVERHEAD AND PRODUCE CLEAR
SKIES OVER ALL BUT FAR EASTERN UPPER MI /LINGERING LK EFFECT
CLOUDS/. PWATS AROUND 50 PERCENT OF NORMAL AND CLEAR SKIES WILL
PROMOTE RADIATIONAL COOLING AND EXPECT LOWS IN THE MID 20S TO LOWER
30S OVER MOST INTERIOR LOCATIONS. UNDER SIMILAR CONDITIONS THIS
MORNING...MANY LOCATIONS IN THE INTERIOR WEST FELL INTO THE UPPER
20S. THEREFORE...EXPECT ANOTHER DECENT FROST/FREEZE ACROSS THE
AREA...WHICH COULD EVEN EFFECT AREAS CLOSE TO THE GREAT LKS
SHORELINES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 450 AM EDT WED SEP 26 2012
TEHRE IS A FAIR AMOUNT OF DISAGREEMENT IN MEDIUM RANGE GUIDANCE FOR
THE NEXT 7 DAYS. CURRENT TROF OVER ERN CANADA INTO THE GREAT LAKES
WILL LIFT OUT OVER THE NEXT FEW DAYS. HOWEVER...ANOTHER SHORTWAVE
WILL BE DROPPING SE AS THE TROF LIFTS OUT LATE WEEK. MODELS HAVE
BEEN STRUGGLING WITH EXACTLY WHAT HAPPENS WITH THAT PIECE OF ENERGY.
MORE ON THAT LATER. FORTUNATELY...THE ARRAY OF SOLUTIONS DOESN`T
IMPACT THE PCPN FCST. THE DIFFERENCES IN GUIDANCE INTO/THRU THE
WEEKEND TRANSITION TO LARGER DIFFERENCES DURING THE EARLY PART OF
NEXT WEEK AS GFS/ECMWF HAVE BEEN VARYING BTWN NW AND WSW FLOW INTO
THE UPPER GREAT LAKES. OVERALL...THIS WILL BE A DRY PATTERN FOR
UPPER MI. TEMP FCST IS SOMEWHAT UNCERTAIN GIVEN THE MODEL
DISCREPENCIES...BUT TREND WILL BE TOWARD ABOVE NORMAL IN GENERAL.
BEGINNING THU...ALTHOUGH ERN TROF WILL BE IN THE PROCESS OF LIFTING
OUT...A SHORTWAVE WILL BE DROPPING SE TOWARD FAR NRN ONTARIO. THIS
WILL RESULT IN A MODEST WAA PATTERN ACROSS THE AREA THU. MODELS SHOW
A DRY COLUMN...SO PCPN IS NOT A CONCERN WITH THE WAA. IN FACT...THE
DAY WILL LIKELY BE MOSTLY SUNNY GIVEN THE DEGREE OF DRY AIR. WAA
WILL HELP TEMPS RISE INTO THE UPPER 50S/LWR 60S PER MIXING TO AROUND
850MB ON FCST SOUNDINGS.
AS SHORTWAVE CONTINUES SE...PASSING OVER THE SRN TIP OF JAMES BAY
FRI...A VERY WEAK SFC TROF WILL SINK S ACROSS THE AREA. WITH MAIN
DYNAMICS PASSING WELL TO THE NE AND A DRY AIR MASS REMAINING OVER
THE AREA...PCPN IS NOT AN ISSUE. 850MB TEMPS TO START THE DAY FRI
ARE 4-6C HIGHER THAN THE PREVIOUS DAY. MIXING TO AROUND 850MB YIELDS
MAX TEMPS AROUND 70F. LOOKS LIKE THERE MAY BE A FAIR AMOUNT OF MID
CLOUD FOR AT LEAST A PORTION OF THE DAY...SO HELD TEMPS GENERALLY TO
THE MID/UPPER 60S.
SHORTWAVE PASSING NEAR THE SRN TIP OF JAMES BAY FRI GETS LEFT BEHIND
OVER THE WEEKEND AS STRONG HEIGHT RISES OCCUR OVER SE CANADA IN THE
WAKE OF DEPARTING ERN TROF. AS THE SYSTEM BECOMES A BROADENING
MIDLEVEL LOW...THE HEIGHT RISES TO THE N END UP PUSHING SYSTEM S OR
SW. 00Z MODEL AGREEMENT IS NOT BAD WITH THE RANGE OF SOLUTIONS
SHOWING THE CENTER OF THE MID LEVEL LOW SOMEWHERE BTWN WRN LWR MI
(GLOBAL GEM) AND NW PA/WRN NY SUN (GFS). AT THIS POINT...THE
DIFFERENCES SEEN IN THE 00Z MODEL RUNS AND IN PREVIOUS RUNS WON`T
IMPACT FCST SIGNIFICANTLY. GIVEN THE DRY ORIGINATION OF THE SYSTEM
AND THE TIME IT WILL TAKE TO FULLY ENTRAIN DEEPER MOISTURE OFF THE
ATLANTIC...PCPN SHOULD NOT BE A CONCERN HERE. LOCATION OF THE MID
LEVEL LOW WILL HAVE MORE OF AN AFFECT ON TEMPS. THE FARTHER W GLOBAL
GEM SOLUTION WOULD BRING A COOLER AIR MASS INTO THE AREA FROM THE NE
FOR SUN (850MB TEMPS 3C E TO 5C W) WHILE THE FARTHER E GFS SOLUTION
WOULD MAINTAIN WARMER WEATHER THRU SUN (850MB TEMPS 4C E TO 10C W).
GIVEN THE VARYING SOLUTIONS OF RECENT DAYS...WILL STAY CLOSE TO A
BIAS CORRECTED CONSENSUS FCST UNTIL LOCATION OF MID LEVEL LOW IS
BETTER AGREED UPON. END RESULT IS HIGHS MAINLY IN THE 60S THIS
WEEKEND.
ECWMF/GFS HAVE STRUGGLED WITH THE PATTERN EARLY NEXT WEEK AS BOTH
MODELS HAVE VARIED FROM HAVING A RIDGE IN THE PACIFIC NW AND NW FLOW
INTO THE UPPER LAKES TO A TROF IN THE PACIFIC NW AND WSW FLOW INTO
THE UPPER LAKES. FOR THE MOMENT...THE 00Z RUNS FAVOR NW FLOW INTO
THE UPPER LAKES WHICH RESULTS IN A SHORTWAVE/COLD FRONT PASSING MON
AND PERHAPS ANOTHER LATE TUE. ONLY INCLUDED A SCHC OF -SHRA MON WITH
FIRST SHORTWAVE. TEMPS MON/TUE SHOULD BE MOSTLY IN THE 60S TO AROUND
70F.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 128 AM EDT WED SEP 26 2012
COLDER AIR MOVING IN BEHIND A SHRTWV LATER TONIGHT ALONG WITH AN A
FURTHER INCREASE IN LOW LEVEL MOISTURE SHOULD LOWER CIGS INTO THE
MVFR RANGE. EXPECT MVFR CIGS TO LIFT BY WED AFTERNOON WITH VFR
CONDITIONS THEREAFTER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT WED SEP 26 2012
HIGH PRES/WEAK PRES GRADIENT WILL GENERALLY DOMINATE FOR THE REST
OF THIS WEEK AND INTO THE WEEKEND. THIS WILL RESULT IN WINDS
UNDER 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...VOSS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 AM EDT WED SEP 26 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 420 PM EDT TUE SEP 25 2012
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL LOW JUST EAST
OF HUDSON BAY WITH TROUGHING TO THE SOUTH DOMINATING THE GREAT LAKES
AND NE CONUS. AN UPSTREAM SHORTWAVE TROUGH WAS LOCATED NW OF LAKE
SUPERIOR AND HELPED SUPPORT AN INCREASE IN SCT DIURNAL SHOWERS FROM
WINNIPEG TO THUNDER BAY ONTARIO. SOME SPRINKLES HAVE ALSO DEVELOPED
EAST OF THE KEWEENAW AND INTO THE HURON MOUNTAINS WITH THE HELP OF
AFTERNOON HEATING AND WEAK LAKE BREEZES. A WEAK PRES GRADIENT AND
WIND FIELD PREVAILED AS HIGH PRESURE FROM SASK/MANITOBA BUILDS INTO
THE NRN GREAT LAKES.
EXPECT SHRA WILL INCREASE LATE TONIGHT AS 850 MB TEMPS FALL TOWARD
-1C AND A WEAK SFC TROF DROPS S ACROSS THE LAKE IN ASSOCIATION WITH
THE SHORTWAVE. WITH LAKE TEMPS ONLY AROUND 10C TO 13C...DELTA/T
VALUES WILL BE MARGINAL FOR LAKE EFFECT PCPN BUT WILL BE AIDED BY
THE SHRTWV/COLD POOL WITH 700 MB TEMPS ALSO DROPPING TO AROUND
-10C.
THE TIMING OF THE TROF WILL ALSO COINCIDE WITH THE MORE FAVORABLE
MIN OF THE DIURNAL CYCLE. WITH LARGE SCALE SUBSIDENCE WITH DIVERGENT
LOW LEVEL ACYC FLOW AND A SHORTER FETCH...LEFT OUT MENTION OF SHRA
WEST OF THE KEWEENAW. AWAY FROM ANY THICKER CLOUDS AND LAKE
INFLUENCE... TEMPS WILL AGAIN DROP AOB FREEZING IN MANY LOCATIONS
OVER THE INTERIOR WEST. ANY LINGERING SHRA IN THE MORNING INTO THE
ERN CWA FAVORED BY NW FLOW WILL DIMINISH AND END BY AFTERNOON AS THE
SFC RIDGE CONTINUES TO BUILD INTO THE AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 420 PM EDT TUE SEP 25 2012
SPLIT FLOW REGIME TO DOMINATE IN THE UPPER LEVELS THROUGH NEXT
WEEKEND WITH HEIGHTS OVER UPPER LAKES STAYING GENERALLY HIGH. ONE
NOTABLE EXCEPTION IS ECMWF AND TO SOME DEGREE GEM-NHEM STILL SHOW
SHORTWAVE TROUGH SLIDING EAST ACROSS NORTHERN CANADA THIS WEEK THEN
DROPPING INTO NORTHERN ONTARIO ON SATURDAY AND THROUGH THE UPPER
GREAT LAKES BY SUNDAY. ECMWF IS FARTHEST WEST WITH UPPER LOW CENTER
AND SUPPOSE WITH ITS SOLUTION THERE COULD END UP BEING SOME SHOWERS
OVER EASTERN CWA SECOND HALF OF THE WEEKEND. ECMWF HAS SHOWN THIS
FOR FOUR MODEL RUNS NOW...SINCE THE 00Z RUN ON 24 SEPT. GFS REALLY
SHOWS NOTHING OF THE SORT WHILE THE GEM-NHEM IS MORE MIDDLE OF THE
ROAD. CONSENSUS POPS KEEPS THINGS DRY FOR NOW...BUT WENT AHEAD AND
NUDGED CLOUD COVER UP OVER THE EAST LATER SATURDAY THROUGH SUNDAY.
WEAK SHORTWAVE TROUGH SLIDES THROUGH AREA NEXT MONDAY BUT LIMITED
MOISTURE RESULTS IN ONLY SLIGHT CHANCES IN THE FORECAST FOR NOW WITH
THE APPROACH OF A SFC TROUGH. PRIMARY IMPACT COULD BE GUSTY SW WINDS
AHEAD OF THE TROUGH SUNDAY INTO MONDAY.
MAIN WEATHER ISSUE THROUGH THE LONG TERM SEEMS TO BE TEMPERATURES
AND FROST/FREEZE POTENTIAL. NOTE THAT EVEN THOUGH WE HAVE
TECHNICALLY ENDED THE FROST/FREEZE PROGRAM FOR THIS FALL AS MANY
AREAS OVER THE REGION HAVE EXPERIENCED BLO FREEZING TEMPS
RECENTLY...MENTION OF FROST IN THE GRIDS REMAINS IN PLACE THROUGH 30
SEPT.
HIGH PRESSURE RIDGE SETTLES OVER THE UPPER LAKES LATER WEDNESDAY
INTO WEDNESDAY EVENING. HIGHS REMAINS OVERHEAD THROUGH SATURDAY.
GIVEN MOSTLY CLEAR SKIES AND RELATIVELY DRY AIR...EXPECT LARGER
DIURNAL TEMPERATURE SWINGS WITH HIGHS WELL INTO THE 60S AND MINS
DIPPING INTO THE 30S. COLDER EXCEPTION WILL BE WEDNESDAY NIGHT AS
RIDGE AXIS DIRECTLY OVERHEAD AND PWATS AS LOW AS 40 PCT OF NORMAL
SHOULD LEAD TO SIGNIFICANT RADIATIONAL COOLING. TWEAKED MINS WELL
BLO FREEZING OVER INTERIOR CWA /LOW-MID 20S FOR FAVORED INLAND COLD
SPOTS/. LACK OF WIND/LAND BREEZE SHOULD EVEN RESULT IN SOME FROST
FORMING PRETTY CLOSE TO THE GREAT LAKES SHORES. WARMER EXCEPTION MAY
BE ON FRIDAY AS BUBBLE OF WARMER AIR ALOFT MOVES ACROSS OUT AHEAD OF
THE UPPER LOW DROPPING ACROSS ONTARIO. POSSIBLE THAT SOME READINGS
COULD PUSH INTO THE 70S IF ALL BREAKS RIGHT. LOWERED DWPNTS SOME FOR
THURSDAY AFTN AND FRIDAY AFTN AS H85 DWPNT DEPRESSIONS ARE HIGHER
THROUGH THAT TIME. EVEN SO...NO FIRE WEATHER CONCERNS ARE EXPECTED
SINCE WINDS STAY LIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 128 AM EDT WED SEP 26 2012
COLDER AIR MOVING IN BEHIND A SHRTWV LATER TONIGHT ALONG WITH AN A
FURTHER INCREASE IN LOW LEVEL MOISTURE SHOULD LOWER CIGS INTO THE
MVFR RANGE. EXPECT MVFR CIGS TO LIFT BY WED AFTERNOON WITH VFR
CONDITIONS THEREAFTER.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 420 PM EDT TUE SEP 25 2012
HIGH PRES/WEAK PRES GRADIENT WILL GENERALLY DOMINATE FOR THE REST OF
THIS WEEK...RESULTING IN WINDS UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
347 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE EAST ACROSS THE AREA TODAY. HIGH PRESSURE
WILL BUILD SOUTHEAST INTO THE REGION TONIGHT AND BE OVER THE CENTRAL
GREAT LAKES MY THURSDAY AFTERNOON. THE HIGH WILL MOVE EAST TO MAINE
AND EXTEND A RIDGE BACK WEST OVER THE LOCAL AREA THROUGH FRIDAY AND
SATURDAY. A WEAK COLD FRONT WILL MOVE SOUTH ACROSS THE AREA SATURDAY
AFTERNOON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONVECTION CONTINUES TO DEVELOP AND MOVE NORTHEAST INTO THE
SOUTHWESTERN PORTION OF THE FORECAST AREA THIS MORNING. THE ACTIVITY
IS MOVING INTO A LESS FAVORABLE ENVIRONMENT AS CAPE WEAKENS ACROSS
EASTERN OHIO AND NORTHWEST PENNSYLVANIA. THE LATEST RUC AND HRRR
MODELS STILL SHOW WEAKENED PRECIPITATION MOVING NORTHEAST ACROSS THE
AREA THIS MORNING.
COLD FRONT SLIDES SOUTHEAST AND SHOULD ARRIVE OVER THE FORECAST AREA
AROUND 18Z THIS AFTERNOON. WITH THE COLD FRONT OVER THE REGION AND
BEST MOISTURE SOUTH OF THE BOUNDARY...IT APPEARS THAT THE BEST
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE OVER THE SOUTHEAST HALF
OF THE FORECAST AREA. LATEST SPC GUIDANCE INDICATES SEE TEXT OVER
THE SOUTHERN PORTIONS AND THIS LINES UP WELL WITH CURRENT THINKING
THAT SOME GUSTY WINDS ARE POSSIBLE WITH THE THUNDERSTORMS. SMALL
HAIL ALSO IS POSSIBLE IF STORMS PENETRATE ABOVE THE 11600 FOOT
FREEZING LEVEL OVER THE REGION. LOW LEVEL JET MAXIMA EXTENDS
SOUTHWEST TO NORTHEAST AHEAD OF THE COLD FRONT AND STORMS COULD TAP
INTO THE GUSTY WINDS PUSHING 40 KNOTS. SO THAT WILL HAVE TO BE
WATCHED CLOSELY WITH CONVECTION THIS AFTERNOON.
TEMPERATURES ONCE AGAIN ON THE TRICKY SIDE THIS AFTERNOON FOR HIGHS.
WARM AIR ADVECTION WILL BE THE PRIMARY REASON FOR RISING
TEMPERATURES. CLOUDS AND AREA OF PRECIPITATION WILL KEEP
TEMPERATURES SUBDUED THROUGH THE DAY. WILL DROP BACK GUIDANCE
TEMPERATURES A COUPLE DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
COLD FRONT SHOULD BE JUST SOUTH OF THE FORECAST AREA BY 00Z THIS
EVENING ALLOWING HIGH PRESSURE AND DRIER AIR TO MOVE INTO THE
REGION. THIS SHOULD GRADUALLY FORCE THE PRECIPITATION OUT OF THE
AREA BY THURSDAY MORNING.
FAIR WEATHER RETURNS FOR THE DAY THURSDAY UNDER THE INFLUENCE OF THE
HIGH PRESSURE. COOL AIR ADVECTION BEHIND THE COLD FRONT IS NOT
REALLY THAT IMPRESSIVE AND HIGHS WILL RECOVER BACK TO THE UPPER 60S
IN THE WEST BUT ONLY LOWER 60S IN THE NORTHEAST. I MAY BE A BIT LOW
ON THE HIGHS IN THE NORTHEAST BUT 850 MB TEMPERATURES ARE AROUND 6
DEGREES C IN THAT AREA COMPARED TO 10 DEGREES C IN THE WEST.
GRADIENT WEAKENS BY THURSDAY NIGHT AND WE WILL LIKELY DECOUPLE TO
ALLOW TEMPERATURES TO DIP INTO THE UPPER 40S TO AROUND 50 DEGREES.
AS MENTIONED EARLIER...AIR MASS WITH THE HIGH PRESSURE IS NOT REALLY
THAT COLD AND SHOULD SUPPORT THE MILDER LOWS.
FRIDAY SHOULD SEE LIGHT NORTHERLY FLOW ACROSS THE AREA WITH LITTLE
CHANGE IN THE TEMPERATURE ALOFT TO SUPPORT WARMING. WILL ONLY GO A
COUPLE TO A FEW DEGREES WARMER ON FRIDAY COMPARED TO THURSDAY. A
SLIGHT NUDGE OF COLDER AIR PUSHES SOUTH FRIDAY NIGHT INTO SATURDAY
AS A COLD FRONT SLIDES SOUTH ACROSS THE AREA. THIS WILL TRANSLATE
INTO SLIGHTLY COOLER HIGHS ON SATURDAY AND SATURDAY NIGHT. COLD
FRONT SHOULD SLIP THROUGH THE AREA DRY. MAY NEED TO KEEP A CLOSE EYE
ON STORM SYSTEM MOVING UP THE EAST COAST FOR POSSIBLE WRAP AROUND
MOISTURE EXTENDING BACK WEST INTO THE FORECAST AREA BY SATURDAY
NIGHT. CURRENT THINKING IS THAT IT WILL HOLD OFF UNTIL SUNDAY.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
SUNDAY IS THE ONLY DAY WITH A QUESTION. SOME LAKE INDUCED CLOUDS AND
SHOWERS COULD BE OCCURRING SUNDAY INTO SUNDAY NIGHT OVER NE OH AND
NW PA. ADDED SOME POPS ESPECIALLY FOR SUNDAY. OTHERWISE HIGH
PRESSURE MOVES THROUGH MONDAY AND THEN WITH THE HIGH TO THE EAST
TUESDAY TEMPERATURES WILL BEGIN TO MODERATE.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE THROUGH THE AREA FROM THE NORTH DURING THE
DAY. IN THE MEANTIME A WAVE OF CONVECTION WILL MOVE ACROSS THE
REGION DURING THE OVERNIGHT...HOW FAR NORTH THE THUNDER GETS IS
THE QUESTION. ALL THE MODELS ARE FORECASTING IFR CEILINGS TO
DEVELOP WENT WITH THAT IDEA...BUT CONFIDENCE IN THE TIMING IS IN
QUESTION. AFTER THIS WAVE OF CONVECTION...SOME SHOWERS AND
THUNDERSTORMS COULD DEVELOP NEAR THE COLD FRONT DURING THE
AFTERNOON. VFR CONDITIONS WILL RETURN TONIGHT.
.OUTLOOK...MAINLY VFR.
&&
.MARINE...
A SOUTHWEST FLOW TODAY WILL GIVE WAY TO A NORTHEAST FLOW TONIGHT. A
COLD FRONT WILL MOVE ACROSS THE LAKE BY EARLY AFTERNOON. AS THE FLOW
BECOMES NORTHEAST TONIGHT THE WINDS COULD INCREASE ENOUGH TO NEED A
SMALL CRAFT ADVISORY. THE PERIOD FOR A SMALL CRAFT ADVISORY WOULD BE
03Z-15Z THURSDAY. THIS WILL HAVE TO BE MONITORED BY THE NEXT SHIFTS.
THE NORTHEAST WINDS WILL DECREASE WEDNESDAY. HIGH PRESSURE WILL
REMAIN TO THE NORTH OF THE LAKE INTO THE WEEKEND WITH A NORTHERLY
FLOW. AT THIS TIME NOT EXPECTING WINDS AND WAVES TO REACH SMALL
CRAFT ADVISORY CRITERIA...HOWEVER...WITH A NORTHEAST FLOW IT IS NOT
TOUGH TO DO...SO THIS WILL HAVE TO BE MONITORED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...LOMBARDY
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
157 AM EDT WED SEP 26 2012
.SYNOPSIS...
A WARM FRONT WAS OVER THE LOWER OHIO VALLEY. A COLD FRONT OVER THE
UPPER GREAT LAKES WILL DROP SOUTHEAST ACROSS THE AREA WEDNESDAY.
HIGH PRESSURE WILL MOVE SOUTHEAST OUT OF CANADA CROSSING THE EASTERN
GREAT LAKES BY FRIDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST RUC AND HRRR MODELS ARE INDICATING CONVECTION WILL CONTINUE
TO DEVELOP OVER CENTRAL INDIANA AND MOVE NORTHEAST INTO THE
FORECAST AREA. DECIDED TO UP POPS ACROSS THE AREA TO ACCOUNT FOR
THIS ACTIVITY. DECIDED TO ADD MENTION OF THUNDER AS WELL SINCE
FORECAST AREA IS ON THE EDGE OF SOME PRETTY GOOD CAPE. THE
INSTABILITY WILL GRADUALLY WORK EAST WITH THE THUNDERSTORMS. I
THINK THE BEST CHANCE FOR THUNDER WILL BE OVER THE WESTERN HALF
VERSUS THE EAST HALF.
TEMPERATURES LOOK GOOD SO NO ADJUSTMENTS THERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
THE COLD FRONT WILL SAG SOUTH ACROSS THE FORECAST AREA ON
WEDNESDAY... PROBABLY A LITTLE SLOWER THAN PROGGED IN PREVIOUS DAYS.
IT COULD BE ONE OF THOSE DAYS WHERE THE WIND SHIFTS A LITTLE FASTER
THAN THE ACTUAL FRONT PASSES SINCE PRESSURES WILL BE FALLING TO THE
SOUTH AND RISING TO THE NORTH. ALSO...WITH A SHALLOW FRONT...THERE
COULD BE A FEW SHOWERS WELL NORTH OF THE ACTUAL FRONT. WILL KEEP A
CHANCE OF SHOWERS MOST OF THE DAY. WILL MENTION THUNDER... MAINLY
ACROSS THE SOUTH HALF OF THE FORECAST AREA.
THE MODELS ARE STILL WISHY WASHY ON WAVES OF LOW PRESSURE THAT MAY
BRUSH THE FORECAST AREA FROM THE SOUTH ON THURSDAY AND FRIDAY. GIVEN
THAT WE ARE HAVING TROUBLE GETTING SIGNIFICANT RAIN THIS FAR NORTH
SO FAR... AND WITH A REINFORCING PUSH OF HIGH PRESSURE... WILL KEEP
THE PROBABILITY OF PRECIPITATION LOW ON THURSDAY AND FRIDAY WITH
THE CAVEAT THAT IT IS A LOWER CONFIDENCE FORECAST. HIGHS AND LOWS
WILL BE NEAR NORMAL...THERE IS NOT TOO MUCH COLD ADVECTION.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THERE IS A LOT OF UNCERTAINTY IN THE DETAILS OF THE EXTENDED...BUT
ON THE LARGE SCALE THE WEEKEND SEEMS DOMINATED BY AN EXPANSIVE UPPER
LOW. THIS FEATURE AND THE LIKELY CLOUD COVER ASSOCIATED WITH IT
SHOULD KEEP TEMPS A BIT BELOW NORMAL. NOT SEEING MUCH TO INITIATE
ANY SHOWERS SO WILL MAINTAIN THE DRY FORECAST. THE FLOW WILL
MODERATE SOME FOR EARLY NEXT WEEK...AND BY TAKING AN ENSEMBLE
APPROACH...RETURN TO A ZONAL FLOW WITH MORE SEASONABLE TEMPERATURES.
THIS IS STILL SIMILAR TO PREVIOUS FORECAST FOR THE LONG TERM SO
LITTLE CHANGES MADE.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE THROUGH THE AREA FROM THE NORTH DURING THE
DAY. IN THE MEANTIME A WAVE OF CONVECTION WILL MOVE ACROSS THE
REGION DURING THE OVERNIGHT...HOW FAR NORTH THE THUNDER GETS IS
THE QUESTION. ALL THE MODELS ARE FORECASTING IFR CEILINGS TO
DEVELOP WENT WITH THAT IDEA...BUT CONFIDENCE IN THE TIMING IS IN
QUESTION. AFTER THIS WAVE OF CONVECTION...SOME SHOWERS AND
THUNDERSTORMS COULD DEVELOP NEAR THE COLD FRONT DURING THE
AFTERNOON. VFR CONDITIONS WILL RETURN TONIGHT.
.OUTLOOK...MAINLY VFR.
&&
.MARINE...
A TROUGH OF LOW PRESSURE IS ORIENTED FROM LAKE HURON TO LAKE
MICHIGAN THIS AFTERNOON. SOUTHWEST WINDS ON LAKE ERIE WILL DECREASE
INTO WEDNESDAY AS THIS TROUGH SETTLES SOUTH OVER THE LAKE. THE SMALL
CRAFT ADVISORY HAS BEEN ALLOWED TO EXPIRE FOR THE OHIO NEARSHORE
WATERS BUT HAS BEEN EXTENDED UNTIL 10 PM IN NW PA WHERE IT WILL TAKE
A LITTLE LONGER FOR WAVES TO COME DOWN.
WINDS WILL VEER AROUND TO THE NORTH BEHIND THE FRONT LATE WEDNESDAY
WITH WAVES BUILDING TO NEAR 4 FEET AGAIN ALONG THE SOUTH SHORES OF
THE LAKE. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR A BRIEF WINDOW.
HIGH PRESSURE WILL BUILD OVERHEAD ON THURSDAY AND FRIDAY WITH WINDS
DECREASING TO AT OR BELOW 10 KNOTS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...LOMBARDY
SHORT TERM...KOSARIK
LONG TERM...MULLEN
AVIATION...KIELTYKA
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1240 AM EDT WED SEP 26 2012
.SYNOPSIS...
A WARM FRONT WAS OVER THE LOWER OHIO VALLEY. A COLD FRONT OVER THE
UPPER GREAT LAKES WILL DROP SOUTHEAST ACROSS THE AREA WEDNESDAY.
HIGH PRESSURE WILL MOVE SOUTHEAST OUT OF CANADA CROSSING THE EASTERN
GREAT LAKES BY FRIDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST RUC AND HRRR MODELS ARE INDICATING CONVECTION WILL CONTINUE
TO DEVELOP OVER CENTRAL INDIANA AND MOVE NORTHEAST INTO THE
FORECAST AREA. DECIDED TO UP POPS ACROSS THE AREA TO ACCOUNT FOR
THIS ACTIVITY. DECIDED TO ADD MENTION OF THUNDER AS WELL SINCE
FORECAST AREA IS ON THE EDGE OF SOME PRETTY GOOD CAPE. THE
INSTABILITY WILL GRADUALLY WORK EAST WITH THE THUNDERSTORMS. I
THINK THE BEST CHANCE FOR THUNDER WILL BE OVER THE WESTERN HALF
VERSUS THE EAST HALF.
TEMPERATURES LOOK GOOD SO NO ADJUSTMENTS THERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
THE COLD FRONT WILL SAG SOUTH ACROSS THE FORECAST AREA ON
WEDNESDAY... PROBABLY A LITTLE SLOWER THAN PROGGED IN PREVIOUS DAYS.
IT COULD BE ONE OF THOSE DAYS WHERE THE WIND SHIFTS A LITTLE FASTER
THAN THE ACTUAL FRONT PASSES SINCE PRESSURES WILL BE FALLING TO THE
SOUTH AND RISING TO THE NORTH. ALSO...WITH A SHALLOW FRONT...THERE
COULD BE A FEW SHOWERS WELL NORTH OF THE ACTUAL FRONT. WILL KEEP A
CHANCE OF SHOWERS MOST OF THE DAY. WILL MENTION THUNDER... MAINLY
ACROSS THE SOUTH HALF OF THE FORECAST AREA.
THE MODELS ARE STILL WISHY WASHY ON WAVES OF LOW PRESSURE THAT MAY
BRUSH THE FORECAST AREA FROM THE SOUTH ON THURSDAY AND FRIDAY. GIVEN
THAT WE ARE HAVING TROUBLE GETTING SIGNIFICANT RAIN THIS FAR NORTH
SO FAR... AND WITH A REINFORCING PUSH OF HIGH PRESSURE... WILL KEEP
THE PROBABILITY OF PRECIPITATION LOW ON THURSDAY AND FRIDAY WITH
THE CAVEAT THAT IT IS A LOWER CONFIDENCE FORECAST. HIGHS AND LOWS
WILL BE NEAR NORMAL...THERE IS NOT TOO MUCH COLD ADVECTION.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THERE IS A LOT OF UNCERTAINTY IN THE DETAILS OF THE EXTENDED...BUT
ON THE LARGE SCALE THE WEEKEND SEEMS DOMINATED BY AN EXPANSIVE UPPER
LOW. THIS FEATURE AND THE LIKELY CLOUD COVER ASSOCIATED WITH IT
SHOULD KEEP TEMPS A BIT BELOW NORMAL. NOT SEEING MUCH TO INITIATE
ANY SHOWERS SO WILL MAINTAIN THE DRY FORECAST. THE FLOW WILL
MODERATE SOME FOR EARLY NEXT WEEK...AND BY TAKING AN ENSEMBLE
APPROACH...RETURN TO A ZONAL FLOW WITH MORE SEASONABLE TEMPERATURES.
THIS IS STILL SIMILAR TO PREVIOUS FORECAST FOR THE LONG TERM SO
LITTLE CHANGES MADE.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A TRICKY FORECAST PERIOD COMING UP WITH SEVERAL FEATURES IMPACTING
THE AREA. SHOWERS WILL CONTINUE TO MOVE EAST INTO PA EARLY TONIGHT
ALLOWING FOR LINGERING MVFR CIGS TO CONTINUE ACROSS THE AREA.
MEANWHILE SOUTHERLY FLOW WILL CONTINUE TO ALLOW FOR INCREASING
MOISTURE INTO THE AREA. TO THE NORTH A COLD FRONT OVER THE NRN
GRTLKS WILL PUSH SOUTH AND CROSS THE AREA DURING WEDNESDAY. MODELS
SUGGESTING MOISTURE WILL BUILD AHEAD OF THE FRONT TO THE NORTH
OVERNIGHT TONIGHT. WITH THAT DEWPOINT ARE EXPECTED TO BEGIN RISING
ACROSS THE AREA...AND WITH A LIGHT S WIND CONTINUING EXPECTING
CIGS TO GRADUALLY FALL LATER TONIGHT ESP AFTER 06Z. MODELS
SUGGESTING ANOTHER PERIOD OF SHRA AND POSSIBLE THUNDER MOVING INTO
CENTRAL OHIO TOWARD 12Z WHICH MAY IMPACT FROM FDY-MFD-CAK. OVERALL
MADE ONLY MINOR CHANGES TO THE IFR PREVIOUSLY FORECAST. EXPECTING
CONDITIONS TO SLOWLY IMPROVE THROUGH THE DAY WED.
.OUTLOOK...LINGERING NON VFR WED NIGHT...OTHERWISE MAINLY VFR
THROUGH THE WEEKEND.
&&
.MARINE...
A TROUGH OF LOW PRESSURE IS ORIENTED FROM LAKE HURON TO LAKE
MICHIGAN THIS AFTERNOON. SOUTHWEST WINDS ON LAKE ERIE WILL DECREASE
INTO WEDNESDAY AS THIS TROUGH SETTLES SOUTH OVER THE LAKE. THE SMALL
CRAFT ADVISORY HAS BEEN ALLOWED TO EXPIRE FOR THE OHIO NEARSHORE
WATERS BUT HAS BEEN EXTENDED UNTIL 10 PM IN NW PA WHERE IT WILL TAKE
A LITTLE LONGER FOR WAVES TO COME DOWN.
WINDS WILL VEER AROUND TO THE NORTH BEHIND THE FRONT LATE WEDNESDAY
WITH WAVES BUILDING TO NEAR 4 FEET AGAIN ALONG THE SOUTH SHORES OF
THE LAKE. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR A BRIEF WINDOW.
HIGH PRESSURE WILL BUILD OVERHEAD ON THURSDAY AND FRIDAY WITH WINDS
DECREASING TO AT OR BELOW 10 KNOTS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...LOMBARDY
SHORT TERM...KOSARIK
LONG TERM...MULLEN
AVIATION...ABE
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS TULSA OK
1154 PM CDT TUE SEP 25 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 6Z TAFS... THUNDERSTORMS HAVE MANAGED TO AVOID OUR TAF
SITES THIS EVENING. WITH NO FRONTAL BOUNDARY MOVEMENT EXPECTED
TONIGHT AND STORMS GENERALLY WEAKENING... HAVE REMOVED MENTION OF
THUNDERSTORMS FROM OVERNIGHT TAFS... WITH THE EXCEPTION OF KMLC
WHICH STILL HAS A CHANCE. AS THE FRONTAL BOUNDARY JUST TO OUR NORTH
MOVES CLOSER TOMORROW... THUNDERSTORM CHANCES SHOULD BE HIGHER
ACROSS OUR NORTH TOMORROW EVENING. HAVE PROB30 GROUPS FOR THIS
ACTIVITY IN ALL SITES EXCEPT KMLC AND KFSM.
&&
.PREV DISCUSSION... /ISSUED 947 PM CDT TUE SEP 25 2012/
..UPDATE...
DISCUSSION...
CONVECTION ACROSS SOUTHERN KANSAS HAS REMAIN CONFINED TO NEARER
THE FRONTAL ZONE WITH NO CURRENT INDICATION OF WORKING SOUTHWARD.
FURTHER WEST...CONVECTIVE COMPLEX HAS ORGANIZED ACROSS SW OK WITH
SEVERE WINDS BEING REPORTED AT SEVERAL LOCATIONS. THIS COMPLEX MAY
TEND TOWARD A MORE SOUTHEASTWARD DEVELOPMENT...WITH GENERALLY MORE
STABLE AIR CURRENTLY ACROSS SE OK LIMITING THE POTENTIAL THIS FAR
EAST. THE 00Z NAM HAS BACKED OFF ON CONVECTION IN THE AREA
OVERNIGHT...AND IS SUPPORTED BY SEVERAL HRRR RUNS. UPDATED
FORECAST WILL REDUCE OVERNIGHT PRECIP CHANCES ACROSS THE ENTIRE
FORECAST AREA. OTHER ELEMENTS APPEAR ON TRACK.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
436 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT OVER THE OHIO VALLEY MOVES EAST TODAY AND TONIGHT AND
STALLS FROM THE MID ATLANTIC TO THE CENTRAL PLAINS ON THURSDAY.
THIS FROM WILL GRADUALLY DRIFT INTO THE SOUTHEAST UNITED STATES ON
SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 420 AM EDT WEDNESDAY...
UPPER TROF WILL DIG INTO THE GREAT LAKES TODAY THEN MOVE EAST. 500
MB PATTERN OVER THE MID ATLANTIC REGION REMAINS ZONAL. FORECAST
AREA WELL WITHIN THE WARM SECTOR AHEAD OF A COLD FRONT THAT
EXTENDED FROM ONTARIO INTO NORTHERN MISSOURI. THE FRONT WILL MOVE
MUCH FASTER EAST THAN SOUTH AND SHOULD TRAIL FROM THE NEW ENGLAND
STATES INTO THE CENTRAL PLAINS BY THIS EVENING. BY THURSDAY
MORNING THE FRONT WILL BE OVER THE FORECAST AREAS BUT PARALLEL TO
THE UPPER FLOW SO EXPECTING LITTLE CHANGE IN THE SURFACE PATTERN FOR
THURSDAY.
CLUSTERS OF SHOWERS AND THUNDERSTORMS LINED UP ALONG THE FRONT AT
4AM. AS THE FRONT GETS CLOSER TO THE COUNTY WARNING AREA SO WILL
THE PRECIPITATION. SREF...LATEST RUC AND LOCAL WRF ALL BRING THE
PROBABILITY OF PRECIPITATION INTO THE NORTHWEST COUNTIES OF THE
FORECAST AREA THIS AFTERNOON. MOST LOCATIONS WILL HAVE ENOUGH
HEATING THIS MORNING TO HAVE ENOUGH INSTABILITY TO SUPPORT
THUNDERSTORMS THIS AFTERNOON.
HAVE TRIMMED HIGHS FOR TODAY ACROSS BATH AND GREENBRIER COUNTIES
WHERE THE CLOUDS WILL MOVE IN THE SOONEST. LOWS TONIGHT WILL
REMAIN MILD WITH ENOUGH MIXING AND CLOUDS TO HOLD UP MINIMUM
TEMPERATURES. STAYED WITH WARMER GUIDANCE FOR LOWS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
A QUASI-STATIONARY COLD FRONT WILL BEGIN TO DRIFT TO THE SOUTH
THURSDAY INTO FRIDAY. THIS FRONT WILL THEN STALL ON THE WESTERN SIDE
OF THE APPALACHIANS FRIDAY NIGHT. ONE REASON THIS FRONT IS SLOW TO
MOVE IS BECAUSE OF ZONAL FLOW ALOFT. ALSO TRAPPED IN THIS ZONAL FLOW
IS A WEAK RIDGE OF HIGH PRESSURE. THIS RIDGE WILL TRACK FROM THE
GREAT LAKES INTO NORTHEASTERN USA BY THURSDAY NIGHT. MODELS
INDICATING THIS RIDGE WILL WEDGE DOWN THE MID ATLANTIC THURSDAY
NIGHT. THIS WEDGE LOOKS SHALLOW AND SHOULD RETREAT TO THE NORTH
FRIDAY AFTERNOON IF LITTLE RAIN FALLS INTO IT.
WITH ZONAL FLOW...WE WILL NEED TO KEEP AN EYE ON THE MID WEST TO SEE
IF ANY STRONG COMPLEXES DRIFT OUR WAY...AS IN THE CASE YESTERDAY.
FOR NOW...MODELS ONLY BRING WEAK WAVES OVER THE AREA. RAIN CHANCES
WILL ALSO GET A BOOST FROM ISENTROPIC LIFT FRIDAY AND FRIDAY NIGHT.
THE BEST ISENTROPIC LIFT AND HEAVIER RAIN SHOULD REMAIN NORTH OF THE
AREA AND ALONG THE MASON-DIXON LINE. THE POTENTIAL FOR SEVERE
WEATHER IS LOW UNLESS A MESOSCALE COMPLEX SURVIVES THE TRIP FROM THE
MID WEST. THE WAY THINGS ARE LOOKING NOW...ONLY ELEVATED THUNDER
FROM SCATTERED STORMS ARE EXPECTED.
TEMPERATURES WILL REMAIN ABOVE NORMAL AS ALONG AS THE FRONT STAYS TO
OUR NORTH AND WEST. IF SHOWERS ARE SCATTERED OVER THE
REGION...ENOUGH ISOLATION SHOULD PEAK TEMPERATURES IN THE MID TO
UPPER 80S IN THE EAST. ACROSS THE MOUNTAINS...UPPER 70S TO LOWER 80S
EXPECTED THURSDAY. SIMILAR TEMPERATURES CAN BE ACHIEVED FRIDAY IF
THE RAIN HOLDS OFF. WITH RAIN EXPECTED...NEAR 80F IN THE EAST TO
LOWER TO MIDDLE 70S WEST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 245 PM EDT TUESDAY...
FRONTAL BOUNDARY IS GOING TO PLAY HAVOC WITH OUR WEATHER AND THE
FORECAST IN GENERAL THIS PERIOD. THE FRONT WORKS INTO THE AREA EARLY
IN THE PERIOD...THEN AS UPPER LOW OVER SRN ONTARIO DEEPENS INTO THE
GREAT LAKES OVER THE WEEKEND...IT SHOULD BE PUSHING THE FRONT
FURTHER SOUTH...WHILE SFC HIGH BUILDS INTO THE MID ATLANTIC.
HOWEVER..THE SW FLOW ALOFT GIVEN UPPER LOW/TROUGH BEING JUST WEST OF
US MAY HANG THE FRONT ACROSS THE CAROLINAS INTO ERN VA...WHILE WAVES
OF LOW PRESSURE MOVE ALONG IT KEEPING CLOUDS AND THREAT OF SHOWERS
AROUND. THIS WILL IMPACT TEMPS AND DECIDED TO GO CLOSER TO THE ECMWF
MOS. EARLY NEXT WEEK MODELS DIVERGE WITH BOTH AGREEING ON THE NRN
STREAM LOW LIFTING NEWD BUT SHOWING DIFFERENCES ON THE SRN STREAM.
THE GFS IS SHOWING SHARPER TROUGH MONDAY WHICH COULD SHIFT DEEPER
MOISTURE EAST...ALTHOUGH THE GFS/ECMWF DO SHOWING ANOTHER TROUGH
DEVELOPING ACROSS THE LOWER MISSISSIPPI VALLEY MONDAY...BUT WITH
UPSTREAM DIFFERENCES...THE ECMWF SHOWS MORE SOUTHERLY FLOW ALOFT
WHILE THE GFS BREAKS OFF AN UPPER HIGH INTO THE OHIO VALLEY
DEPICTING MORE NW FLOW ALOFT. ECMWF HAS BEEN DOING A BETTER JOB
OVERALL...AND HPC LINGERS THE FRONT AROUND THE EASTERN CAROLINAS
MON-TUE WITH CHANCES FOR PRECIP REMAINING. WEDGE MAY DEVELOP AS SFC
HIGH BUILDS SWD FROM THE MID ATLANTIC BY TUESDAY WITH EASTERLY FLOW
KEEPING MORE CLOUDS AROUND.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AS OF 125 AM EDT WEDNESDAY...
SATELLITE PICTURES SHOWED CLOUDS ONLY SCATTERED CLOUDS LEFT ACROSS
MUCH OF VIRGINIA AND NORTH CAROLINA. FOG WAS FORMING...ESPECIALLY
IN AREAS THAT HAD RAINFALL EARLIER ON TUESDAY. HIGH CONFIDENCE THAT
THERE WILL BE PERIODS OF IFR TO LIFR FOG AT LYH/BCB AND LWB BEFORE
14Z/10AM.
CLOUDS WILL SPREAD BACK INTO THE AREA FROM THE WEST THIS MORNING.
PROBABILITY OF PRECIPITATION IS NOT HIGH ENOUGH TO INCLUDE IN THE
TAFS AT THIS TIME. BEST CHANCE REMAINS WEST AND NORTH OF LWB. WINDS
WSW-SW 7-10KTS...WITH LOW END GUSTS EXPECTED IN THE AFTERNOON.
OVERALL VFR/MVFR CONDITIONS ARE EXPECTED TO PERSIST INTO WEDNESDAY AS
A COLD FRONT STALLS ACROSS THE AREA THROUGH SATURDAY. DEWPOINTS
WILL CREEP BACK UP THROUGH THE END OF THE WEEK...SO PATCHY MORNING
FOG MAY DEVELOP DURING THE PREDAWN HOURS AT LWB/BCB...AND AT ANY
SITE THAT SEES PRECIPITATION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...WP
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1227 AM CDT WED SEP 26 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
HIGH PRESSURE WAS BUILDING INTO WISCONSIN THIS AFTERNOON OUT OF
CANADA...RESULTING IN QUIET WEATHER. JUST A FEW FAIR WEATHER CU
DEVELOPED OVER NORTHERN WISCONSIN AND ALONG WITH LAKESHORE. THIS
AREA OF HIGH PRESSURE WILL CONTINUE TO PUSH INTO NORTHEAST WI
DURING THE SHORT TERM...WITH THE MAIN FORECAST CHALLENGES BEING
CLOUDS AND TEMPERATURES.
A 500MB SHORTWAVE WILL PASS OVER LAKE SUPERIOR OVERNIGHT INTO
WEDNESDAY...BRUSHING NORTHERN WISCONSIN AS IT DOES SO. WITH SFC
HIGH PRESSURE MOVING OVER WISCONSIN...DRY AIR AND A LACK OF
FORCING WILL PREVENT ANY PRECIP SO KEPT DRY FORECAST GOING.
MODELS HAVE BEEN STRUGGLING WITH CLOUDS WITH THIS FEATURE AS IT
MOVES THROUGH. CURRENT SAT ELITE AND RAP MODEL ANALYSIS SHOWS THAT
MOST OF THE MOISTURE ASSOCIATED WITH THE CLOUDS CURRENTLY IN
NORTHEAST MINNESOTA NEAR THE DIGGING SHORTWAVE IS CONFINED TO 925
AND 850MB...SO USED THIS INFORMATION FOR CLOUD FORECAST FOR
TONIGHT AND WEDNESDAY. CU FROM THIS AFTERNOON WILL DISSIPATE WITH
THE SUNSET OVER NORTHERN WI...BUT WILL LINGER NEAR THE LAKESHORE
WITH THE CONTINUED NE FLOW. THE NEXT AREA OF CLOUDS WILL MOVE INTO
NORTHERN WISCONSIN AFTER 06Z TONIGHT. CLOUDS WILL BE LIMITED AT
FIRST...BUT THEN SHOULD INCREASE IN COVERAGE TOMORROW...ESPECIALLY
DURING THE AFTERNOON...AS SUN AIDS IN CU DEVELOPMENT AND
SUFFICIENT 850MB MOISTURE OVERSPREADS THE AREA. NORTHERN WISCONSIN
SHOULD SEE THE MOST CLOUDS AS IT IS NEAREST TO THE PASSING
SHORTWAVE...WITH A MIX OF SUN AND CLOUDS ELSEWHERE.
DIDNT CHANGE MUCH TEMPERATURE-WISE FROM PREVIOUS FORECAST AS
NORTHWEST FLOW WILL KEEP THINGS COOLER THAN NORMAL ON WEDNESDAY.
WIDESPREAD FROST IS AGAIN EXPECTED IN NORTHERN WI WHERE GROWING
SEASON HAS ENDED. PATCHY FROST IS POSSIBLE IN CENTRAL WISCONSIN
TONIGHT...HOWEVER THINK TEMPS WILL BE SLIGHTLY TOO WARM FOR
WIDESPREAD FROST DEVELOPMENT.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY.
QUIET WEATHER PATTERN EXPECTED THROUGH THE PERIOD. MODELS CONTINUE
TO STRUGGLE WITH CLOSED UPPER LOW ACROSS THE EASTERN UNITED STATES
OVER THE WEEKEND. LATEST GFS IS FURTHER WEST THAN THE CANADIAN AND
THE 12Z LOW RES ECMWF IS FURTHER WEST THAN BOTH THE CANADIAN/GFS.
DID NOT RECEIVE THE 12Z HIGH ECMWF...THEREFORE WILL CONTINUE WITH A
DRY AND CLEAR TO PARTLY CLOUDY FORECAST FOR THE WEEKEND. IF ECMWF
TREND IS CORRECT...LATER SHIFT MAY NEED TO ADD MORE CLOUDS AND
MAYBE A SMALL CHANCE OF SHOWER OVER THE WEEKEND WITH ENERGY
PIVOTING AROUND THE UPPER LOW.
OTHERWISE...IT WILL BE SEASONABLE WITH LOWS IN THE 30S TO LOWER
TO MIDDLE 40S AND HIGHS IN THE 60S TO AROUND 70. DID LOWER MIN
TEMPERATURES A FEW DEGREES EACH NIGHT THROUGH THE WEEKEND...
ESPECIALLY IN THE TYPICAL COLD SPOTS NORTH AND WEST OF GREEN BAY
AND THE FOX CITES. ALSO RAISED MAX TEMPERATURES A FEW DEGREES ON
FRIDAY BASED ON 925MB TEMPERATURES AND EXPECTED DRY AIR MASS IN
PLACE.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH
WEDNESDAY NIGHT FOR MOST LOCATIONS AS SURFACE HIGH PRESSURE
BUILDS ACROSS THE WESTERN GREAT LAKES. SHALLOW MOISTURE BETWEEN
4000-6000FT WILL CONTINUE TO LEAD TO SOME CLOUDS ACROSS MAINLY
NORTHERN AND EASTERN WI TONIGHT...WITH SOME MVFR CIGS AT TIMES
OVER EAST CENTRAL WI. AT 06Z A NORTHEAST TO SOUTHWEST BAND OF MVFR
CIGS WERE GRADUALLY SPREADING FROM SHAWANO TO CLINTONVILLE TO
WAUPACA.
OTHERWISE FOR TODAY OR WEDNESDAY...FAIR WEATHER CUMULUS CLOUDS
WILL DEVELOP BETWEEN 4000 AND 5000FT. A BROKEN DECK OF CLOUDS
REMAINS POSSIBLE IN THE LATE MORNING AND AFTERNOON...ESPECIALLY
ACROSS NORTH CENTRAL AND FAR EASTERN WI. THE CLOUDS WILL DISSIPATE
DURING THE LATE AFTERNOON AND EARLY EVENING HOURS...WITH MAINLY
CLEAR SKIES EXPECTED INTO THURSDAY MORNING.
SB
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
1023 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT WILL BRING SOME SHOWERS AND A SLIGHT CHANCE
OF THUNDERSTORMS THIS AFTERNOON INTO THIS EVENING FOR EASTERN NEW
YORK AND WESTERN NEW ENGLAND. HIGH PRESSURE WILL BRIEFLY BUILD IN
FROM THE GREAT LAKES REGION ON THURSDAY WITH FAIR AND DRY WEATHER.
AS THE HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST THURSDAY
NIGHT...A FRONTAL BOUNDARY MAY MOVE NORTHWARD FROM THE MID ATLANTIC
REGION WITH SOME RAIN...PREDOMINANTLY FOR AREAS TO THE SOUTH AND
EAST OF THE CAPITAL DISTRICT TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1023 AM EDT...THE FIRST WAVE OF SHOWERS DUE TO ISENTROPIC
LIFT/WARM AIR ADVECTION HAS MOVED AWAY FROM THE REGION INTO NEW
ENGLAND...LEAVING OUR AREA IN A LULL FOR NOW. WE HAVE DROPPED POPS
TO JUST SLIGHT CHC FOR THE REMAINDER OF THE MORNING HOURS...AS SFC
FORCING FROM A COLD FRONT REMAINS OFF ACROSS THE EASTERN GREAT
LAKES. THE 3KM HRRR AGREES WITH THIS IDEA OF A QUIET REMAINDER OF
THE MORNING...WITH SOME SHOWERS RETURNING FOR LATER IN THE DAY.
WE ARE EXPECTING SHOWERS TO REKINDLE IN THE EARLY PM. PWATS WILL
BE AROUND AN INCH TO AN INCH A THIRD OVER THE REGION. THE IMMENSE
AMOUNT OF CLOUD COVER /CLOUDY OR MOSTLY CLOUDY CONDITIONS ARE
FORECASTED/ SHOULD PREVENT SIGNIFICANT SFC HEATING AND
DESTABILIZATION. SBCAPES ARE GENERALLY UNDER A FEW HUNDRED J/KG
FROM BOTH THE NAM AND GFS. THERE IS A NARROW RIBBON OF NEGATIVE
SHOWALTER VALUES OR BEST LIFTED INDICES AHEAD OF THE BOUNDARY LATE
IN THE AFTERNOON FROM THE CAPITAL REGION...CNTRL MOHAWK
VALLEY...AND SRN VT SOUTH AND EAST. MID LEVEL LAPSE RATES CONTINUE
TO BE RATHER WEAK. WE KEPT A SLIGHT CHC OF THUNDERSTORMS HERE.
POPS WERE CONTINUED IN THE HIGH CHC AND LIKELY VALUES LATE.
THERE IS NOT AN ANTICIPATION OF ANY SEVERE THUNDERSTORMS TODAY DUE
TO THE MEAGER INSTABILITY AND WEAK LAPSE RATES PROJECTED BY THE
GUIDANCE.
HIGHS TODAY WILL GENERALLY BE IN THE 60S...ALTHOUGH SOME LOWS 70S
ARE POSSIBLE IN NW CT AND THE MID HUDSON VALLEY OF NY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE COLD FRONT MAKES STEADY PROGRESS ACROSS THE REGION
WITH THE NAM BEING MUCH FASTER THAN THE GFS. WE KEPT SLIGHT OR LOW
CHANCE OF SHOWERS AROUND UNTIL MIDNIGHT TO 0600 UTC...SINCE THE
UPPER LEVEL TROUGH AXIS STILL LINGERS UPSTREAM EVEN ON THE NAM.
HIGH PRESSURE STARTS TO BUILD IN QUICKLY FROM S-CNTRL ONTARIO AND
THE GREAT LAKES REGION. SOME FOG MAY FORM IN THE FAVORED AREAS OF
THE LAKE GEORGE REGION...SRN VT...AND THE BERKSHIRES. SOME PATCHY
FOG WAS ADDED TO RECENT WET GROUNDS...AND CLEARING SKIES. LOWS
WILL GENERALLY BE IN THE U40S TO M50S FROM THE MOHAWK VALLEY...AND
CAPITAL REGION SOUTH AND EAST WITH U30S TO M40S NORTH AND WEST.
SEE THE HYDRO SECTION FOR QPF AMOUNTS.
THURSDAY...HIGH PRESSURE BUILDS IN FOR A FINE EARLY FALL DAY WITH
PARTLY TO MOSTLY SUNNY CONDITIONS DUE TO THE SUBSIDENCE WITH THE
ANTICYCLONE. WE LEANED A LITTLE CLOSER TO THE COOLER MAVMOS MAX
TEMPS WITH H850 TEMPS OF +2C TO +6C. MIXING SHOULD BE FROM H800 TO
H850. MAX TEMPS WILL GENERALLY BE IN THE 60S WITH SOME U50S OVER
THE SRN DACKS...SRN GREENS...AND ERN CATSKILLS.
THURSDAY NIGHT...THIS WILL BE INTERESTING WITH HIGH PRESSURE
SHIFTING EASTWARD OFF THE COAST...AND THE OLD FRONTAL BOUNDARY
BENDING NORTHWARD FROM THE MID ATLANTIC REGION...AND OHIO VALLEY.
THE NRN ZONES COULD BE MOSTLY CLEAR AND CALM WITH A POTENTIAL
FROST OR FREEZE. FROM THE CAPITAL REGION SOUTH...MID AND HIGH CLOUDS
WILL INCREASE. THE GUIDANCE HAS BACKED OFF A LITTLE...BUT FROM KPOU
SOUTH AND EAST SOME LIGHT RAIN MAY POP UP WITH INCREASING LOW
LEVEL THERMAL ADVECTION IN ADVANCE OF THE FRONT...AND WITH A
SHORT- WAVE RIPPLING ALONG. LOWS WILL RANGE FROM THE U20S TO M30S
NORTH OF THE CAPITAL REGION TO U30S TO M40S SOUTH AND EAST.
FRIDAY...LOCATIONS MAINLY SOUTH AND EAST OF THE CAPITAL REGION MAY
SEE PERIODS OF LIGHT RAIN EVOLVE INTO A STEADIER RAIN BY AFTERNOON
BASED ON THE NAM/EC/GFS/CAN GUIDANCE. THERE WILL LIKELY BE A SHARP
CUTOFF FROM THE RAINFALL...AS WEAK LOW PRESSURE MOVES SOUTH OF LONG
ISLAND. SLIGHT CHANCES OF RAINFALL WERE BROUGHT UP TO THE CAPITAL
REGION LATE IN THE DAY. A BROAD CUTOFF LOW WILL BE DESCENDING
EQUATORWARD FROM JAMES BAY. MORE SUNSHINE MAY OCCUR NORTH OF THE
TRI CITES...AS TEMPS WILL RUN NEAR NORMAL TO CLOSE THE WORK WEEK
WITH U50S TO U60S OVER THE REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
UNSETTLED WEATHER IS EXPECTED FOR MUCH OF THE LONG TERM
PERIOD...ALTHOUGH MUCH UNCERTAINTY REMAINS IN TERMS OF TIMING OF
PRECIPITATION AS WELL AS WHICH FORECAST PERIODS HAVE THE GREATEST
PROBABILITY OF PRECIPITATION. THE FA IS EXPECTED TO BE IMPACTED BY A
LARGE UPPER CLOSED LOW INITIALLY OVER CANADA AS WELL AS A SERIES OF
COASTAL SYSTEMS AT THE SURFACE LIFTING NORTHEAST FROM NEAR DELMARVA
FRIDAY NIGHT...PASSING EAST OF THE JERSEY COAST AND SOUTHEAST OF
LONG ISLAND ON SATURDAY INTO SUNDAY...AND FINALLY OUT TO SEA ON
MONDAY. MEANWHILE...THE UPPER CLOSED LOW IS EXPECTED TO BE ANYWHERE
FROM SOUTHEAST OF JAMES BAY TO UPPER MICHIGAN SATURDAY MORNING AND
THEN GRADUALLY SLIDE SOUTHWEST INTO THE EASTERN GREAT LAKES OR OHIO
VALLEY ON SUNDAY BEFORE LIFTING NORTHEAST ON MONDAY INTO THE EASTERN
SAINT LAWRENCE VALLEY BY MONDAY NIGHT. THE GFS IS THE FARTHEST EAST
WITH THIS FEATURE AND HAS THE EARLIEST DEPARTURE AWAY FROM THE
REGION ON MONDAY...WHILE THE GGEM IS THE FARTHEST WEST AND SLOWEST
WITH THE ECMWF TRACK IN BETWEEN.
AT THIS POINT PLAN ON GOING WITH MAINLY CHANCE POPS FROM FRIDAY
NIGHT THROUGH MONDAY AND THEN MAINLY DRY WEATHER MONDAY NIGHT AND
TUESDAY AS THE NOSE OF A RIDGE OF HIGH PRESSURE GRADUALLY BUILDS
INTO THE NORTHEAST ON TUESDAY. ALSO EXPECT A CONSIDERABLE AMOUNT OF
CLOUD COVER FROM FRIDAY NIGHT INTO MONDAY MORNING ALTHOUGH CANNOT
RULE OUT SOME BREAKS IN THE CLOUD COVER AS WELL AS PCPN ACRS
NORTHWEST PORTION OF FA ESPECIALLY DURING THE SATURDAY NIGHT AND
SUNDAY TIME FRAME AS A DRY SLOT MAY DEVELOP BETWEEN SURFACE LOW
PASSING SOUTHEAST AND UPPER LOW STILL TO THE WEST OR SOUTHWEST.
HIGHS ARE GENERALLY EXPECTED TO BE IN THE UPPER 50S TO UPPER 60S
SATURDAY THROUGH MONDAY WITH THE COOLEST OF THE THREE DAYS LIKELY TO
BE SATURDAY. HIGHS ON TUESDAY SHOULD REBOUND TO THE 60S TO LOWER 70S
WITH MORE SUNSHINE. LOWS ARE EXPECTED TO BE IN THE MID 40S TO MID
50S FRIDAY NIGHT THROUGH SUNDAY NIGHT WITH LOWS IN THE 40S TO AROUND
50 ON MONDAY NIGHT WITH MORE BREAKS IN THE CLOUD COVER.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
MAINLY MVFR CONDITIONS WILL PREVAIL AT THE TAF SITES FOR MUCH OF
THE TAF PERIOD ENDING AT 12Z THURSDAY...THE EXCEPTIONS WILL BE
SOME IFR CONDITIONS AT KGFL AND SOME VFR CONDITIONS AT KPOU THIS MORNING.
THE FIRST BAND OF SHOWERS HAS ALL BUT ENDED ACRS THE AREAS AND
AFTER A LULL THIS MORNING MORE SHOWERS ARE EXPECTED THIS AFTERNOON
BEFORE THE PASSAGE OF A COLD FRONT THIS EVENING. ANY LINGERING
SHOWERS WILL END DURING THE EVENING WITH CIGS STILL REMAINING
MAINLY MVFR FOR THE REMAINDER OF TONIGHT.
WINDS WILL BE SOUTH TO SOUTHWEST AT 5-8 KTS WITH WINDS THEN
SHIFTING TO THE NORTH-NORTHWEST AT 3-6 KTS DURING THE EVENING IN
THE WAKE OF THE COLD FRONT.
OUTLOOK...
THU-FRI...VFR. CHC MVFR KPOU W/CHC SHWRS ON FRI.
SAT-SUN...MAINLY VFR. CHC -SHRA.
&&
.FIRE WEATHER...
A COLD FRONT WILL BRING SOME RAIN AND A SLIGHT CHANCE OF
THUNDERSTORMS TODAY INTO EARLY THIS EVENING FOR EASTERN NEW YORK AND
WESTERN NEW ENGLAND. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM THE
GREAT LAKES REGION ON THURSDAY WITH FAIR AND DRY WEATHER.
UNSETTLED WEATHER MAY RETURN FRIDAY INTO THE WEEKEND FOR PARTS OF
THE REGION.
FIRE WEATHER PROBLEMS CONTINUE TO BE NON EXISTENT IN THE REGION
WITH A WETTING RAIN CONTINUING TODAY INTO TONIGHT. RH VALUES WILL
REMAIN HIGH TODAY AND TONIGHT. EXPECT THEM TO LOWER IN THE DRIER
AIR MASS BY THURSDAY AFTERNOON TO 35 TO 50 PERCENT.
THE WINDS WILL BE FROM THE SOUTH OR SOUTHWEST AT 5 TO 15 MPH
TODAY...AND THEN SHIFT TO THE WEST OF NORTHWEST AT 5 TO 10 MPH
TONIGHT. THURSDAY WILL FEATURE NORTH OR NORTHWEST WINDS OF 10 TO
15 MPH.
&&
.HYDROLOGY...
NO WIDESPREAD PROBLEMS ARE EXPECTED IN THE ALY HYDRO SERVICE AREA
THE NEXT 5 DAYS.
THE COLD FRONT AND UPPER LEVEL DISTURBANCE TODAY INTO TONIGHT WILL
BRING AREAL RAINFALL AMOUNTS RANGING FROM TWO TENTHS TO A HALF AN
INCH OR SO...THOUGH ANY LOCATION THAT MIGHT GET CAUGHT UNDER A
THUNDERSTORM COULD RECEIVE AROUND AN INCH. RIVERS...
STREAMS...CREEKS...BROOKS AND OTHER BODIES OF WATER MAY HAVE
MINIMAL RISES AT BEST. THE 06Z HPC QPF WAS USED CLOSELY PRIOR TO
THURSDAY.
HIGH PRESSURE WILL BRING DRY WEATHER TO MOST OF THE HSA THURSDAY
AND THURSDAY NIGHT.
A FRONTAL BOUNDARY LIFTING NORTHWARD FROM THE MID ATLANTIC
REGION...AND A CUTOFF LOW MAY BRING PERIODS OF SHOWERS AND RAIN TO
THE HSA FRIDAY INTO THE WEEKEND. THE NWP GUIDANCE IS HIGHLY
VARIABLE ON THE EVOLUTION OF WHAT HAPPENS THIS WEEKEND. AT THIS
POINT LIGHT TO MODERATE RAINFALL IS GENERALLY ANTICIPATED FRIDAY
INTO SATURDAY FROM THE CAPITAL REGION SOUTH AND EAST /A FEW TENTHS
OF AN INCH TO THREE QUARTER OF AN INCH/...BUT A STEADIER MODERATE
RAINFALL MAY OCCUR ESPECIALLY SOUTH OF THE CAPITAL REGION...AND
EAST OF THE HUDSON VALLEY LATER IN THE WEEKEND. THE PLACEMENT OF THE
RAINFALL...AND HOW MUCH QPF OCCURS WILL DEPEND ON THE LOCATIONS OF
THE CUTOFF LOW. TRENDS WILL CONTINUE TO BE FOLLOWED OVER THE NEXT
FEW DAYS.
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.
&&
.EQUIPMENT...
THE KENX DOPPLER RADAR WILL BE UNDERGOING REPAIRS AS ADDITIONAL
PARTS ARE ON ORDER. THE KENX RADAR WILL CONTINUE TO BE DOWN AND IS
EXPECTED TO BE BACK IN SERVICE BY MID AFTERNOON ON WEDNESDAY
SEPTEMBER 26TH 2012. WE APOLOGIZE FOR ANY INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/WASULA
NEAR TERM...FRUGIS/WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...WASULA
EQUIPMENT...WFO ALY
AREA FORECAST DISCUSSION
NWS NEW YORK NY
912 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE WEST TODAY...THEN CROSSES THE
TRI-STATE TONIGHT...FOLLOWED BY HIGH PRESSURE BUILDING IN THROUGH
THURSDAY NIGHT...AS THE FRONT STALLS TO OUR SOUTH. A NEARLY
STATIONARY FRONT OFFSHORE WILL RESULT IN UNSETTLED WEATHER FRIDAY
INTO EARLY NEXT WEEK. FAIR WEATHER THEN ATTEMPTS TO ESTABLISH
ITSELF BY TUESDAY AS WEAK HIGH PRESSURE BUILDS IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST RADAR TRENDS AND 6Z/7Z HRRR 6Z NAM/GFS AND 3Z SREF ALL
SUGGEST THAT AFTER CURRENT BATCH OF SPOTTY LIGHT RAIN MOVES
THROUGH IN THE NEXT HOUR...THAT THE REMAINDER OF THE MORNING
SHOULD BE BASICALLY DRY...ESPECIALLY OVER THE SE 2/3 OF THE CWA.
WILL CONTINUE TO MONITOR ONGOING PRECIPITATION OVER S CENTRAL
PA...BUT IT APPEARS TO BE FALLING APART AS IT HEADS ENE...AND
GIVEN MARINE AIR MASS IN PLACE EAST OF THE APPALACHIANS...THIS
TREND SHOULD CONTINUE. AS A RESULT HAVE LOWERED POPS FOR MOST OF
THE CWA THIS MORNING BASED ON A BLEND OF 7Z HRRR/6Z NAM/3Z SREF POPS.
REMAINDER OF FORECAST APPEARS ON TRACKS...WITH MINOR ADJUSTMENT
MADE TO THE GRIDS FOR THIS MORNING TO REFLECT LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE.
SPOTTY LIGHT RAIN THIS MORNING IN RESPONSE TO 850 WARM FRONT
LIFTING THROUGH THE AREA. SHOWERS LIKELY ACROSS NW 1/3 OF THE CWA
WITH SCT SHRA ELSEWHERE BY LATE AFTERNOON AHEAD OF A COLD
FRONT...AND WITH A PASSING 700 HPA VORTICITY MAXIMUM. SHOULD HAVE
MODEST INSTABILITY BY LATE AFTERNOON - 100-500 J/KG OF CAPE - TO
WARRANT MENTION OF ISOLD TSTMS AS WELL. 30-40 KT OF BULK SHEAR
WITH THE MEAGER CAPE WILL LIKELY SHEAR OUT STORMS BEFORE THEY CAN
BECOME STRONG TO SEVERE...BUT WITH A 35 KT LOW LEVEL JET THE
POSSIBILITY OF A SEVERE STORM LATE IN THE AFTERNOON CANNOT BE
COMPLETELY RULED OUT.
FOR HIGHS TODAY USED A BLEND OF MIXING DOWN FROM 950 HPA NEAR THE
COAST...900 HPA INLAND...NAM 2-METER TEMPERATURES AND MAV/MET
GUIDANCE. EXPECT READINGS TO BE 5 DEGREES OR SO ABOVE NORMAL.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC BEACHES TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
700 HPA TROUGH ALONG WITH SURFACE-850 COLD FRONT PASSES THROUGH
TONIGHT. TAPER LIKELY POPS OFF TO SLIGHT CHANCE FROM NW TO SE
WITH ITS PASSAGE. LIKE LATE THIS AFTERNOON...THE COMBINATION OF
MEAGER CAPES AND A STRONG LOW LEVEL JET WARRANT A SLIGHT CHANCE OF
THUNDER...WITH A SEVERE STORM OR TWO NOT COMPLETELY OUT OF THE
QUESTION - BUT VERY UNLIKELY. USED A BLEND OF MAV/MET GUIDANCE
WITH NAM 2-METER TEMPERATURES FOR LOWS...WITH VALUES 5-10 DEGREES
ABOVE NORMAL.
PASSING 500 HPA TROUGH WARRANTS SLIGHT CHANCE POPS EARLY...BUT FOR
THE MOST PART EXPECT THURSDAY TO BE DRY WITH DECREASING LOUD COVER
AS HEIGHTS RISE IN THE WAVE OF THE SYSTEM LIFTING NE INTO THE
CANADIAN MARITIMES. FOR HIGHS USED A BLEND OF MIXING DOWN FROM 850
HPA WITH MAV/MET GUIDANCE AND NAM 2-METER TEMPERATURES.
FORECASTING VALUES TO BE A FEW DEGREES ABOVE NORMAL AS A
RESULT...AS COOLER TEMPERATURES IN THE LOW LEVELS DO NOT PUSH IN
UNTIL LATE IN THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
LATEST DATA BRINGS INCREASING CONFIDENCE IN A RAINY PERIOD FRI THROUGH
THE WEEKEND.
00Z MODELS SHOW THAT ACTIVE WEATHER WILL FOLLOW ROUGHLY IN THE VICINITY
OF THE 10C H85 ISOTHERM. THIS HAPPENS TO BE OVER OR NEAR THE CWA
THIS WEEKEND. BEFORE THAT HOWEVER...SOME UNCERTAINTY WITH RESPECT
TO PRECIPITATION CHANCES THU NIGHT AND FRI.
NAM AND ECMWF WERE THE FASTEST WITH THE PRECIPITATION DURING THAT
PERIOD. THIS IS THE TIMING FAVORED BY MODEL DIAGNOSTICS. THE GFS
KICKS IN AROUND 18Z FRI. TRENDED THE FCST TOWARDS THE FASTER
PROGS...WHICH TRANSLATES TO INCREASING CHANCES FOR LGT RAIN
THROUGH THE NIGHT.
CHANCES FOR RAIN FRI. MAINTAINED THE 40 POPS BECAUSE THE NAM SHOWED
MARGINAL PRECIPITATION AMOUNTS FOR MEASURABLE. IF THE MODEL CONSENSUS
CONTINUES HOWEVER...POPS WILL NEED TO BE RAISED SIGNIFICANTLY.
MID LEVEL MOISTURE CONVERGENCE ZONE REMAINS OVER THE CWA THIS
WEEKEND. IN ADDITION...H5 TROUGH WILL PRESENT THE OPPORTUNITY FOR
COASTAL CYCLOGENESIS. GFS AND ECMWF BOTH POINT TO THIS OCCURRING...
ALTHOUGH THE DETERMINISTIC SOLUTIONS ARE NOT EXACTLY ON THE SAME
SCHEDULE. OUTSIDE OF THIS LOW PRES DEVELOPMENT...PERIODS OF LGT
RAIN POSSIBLE DUE TO THE MOISTURE CONVERGENCE ALONE. POPS HAVE
THEREFORE BEEN INCREASED BY 10 PCT TO HIGH CHANCE.
IT LOOKED LIKE THE MODELS CLEARED THINGS OUT FOR MON...BUT THE 00Z
ECMWF ROLLED IN WET. FORCED TO MAINTAIN CHANCE SHRA FOR THIS PERIOD.
BEHAVIOR OF THE H5 CLOSED LOW IS THE MAIN DRIVER OF THE FCST. IT
SHOULD BE NOTED THAT THE 00Z ECMWF IS ABOUT 10DAM DEEPER THAN THE
GFS ENSEMBLE MEMBERS...BUT CLOSE TO THE CLUSTERING POSITION-WISE.
THE GFS IS DEEPER THAN THE ECMWF AND NE OF THE ENSEMBLE DATA...SO
APPEARS TO BE EVEN FURTHER AWAY FROM THE CONSENSUS. FCST IS
UNCERTAIN IN THIS TIME PERIOD.
IT DOES APPEAR SUPPRESSION OF HEIGHTS OVER THE CENTRAL CONUS TAKES
PLACE ON TUE...CHANGING THE UPPER LEVEL PATTERN. THEREFORE KEPT A DRY
FCST FOR TUE.
TEMPS THU NIGHT-FRI ARE A BLEND OF THE BIAS CORRECTED GFS MOS
(BCGMOS)/MET/MAV. THE REMAINDER OF THE FCST A BLEND OF THE
BCGMOS/GFS ENSEMBLE MEAN MOS/ECMWF MOS.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT WILL LIFT THROUGH TODAY. A COLD FRONT WILL APPROACH
LATE THIS AFTERNOON AND THIS EVENING...AND MOVE THROUGH
LATE TONIGHT.
THERE IS SOME UNCERTAINTY ON STRENGTH OF GUSTS TODAY IN MODERATE
S-SW FLOW. THEY COULD BE A FEW KT STRONGER THAN FCST FROM 17Z-
21Z...AND MAY LINGER A FEW HOURS LONGER THAN CURRENTLY FCST.
BRIEF MVFR VSBY POSSIBLE IN ANY SHOWERS...ESPECIALLY AT KSWF AND
AHEAD OF COLD FROPA THIS EVENING. AS THE COLD FRONT APPROACHES...
EXPECT SCT TO NUMEROUS SHOWERS...POSSIBLY A TSTM CAPABLE OF
PRODUCING GUSTS UP TO 30 KT WHICH IS NOT YET MENTIONED IN TAF DUE
TO LOW PROBABILITY OF OCCURRENCE.
MVFR VSBY ALSO POSSIBLE AFTER COLD FROPA AT KSWF...WITH LOW
CONFIDENCE AS DRIER AIR WILL BE FILTERING IN AT THE SAME TIME.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MODERATE-HIGH CONFIDENCE IN WINDS.
GUSTS AROUND 20 KT POSSIBLE BEFORE 14Z.
KLGA FCSTER COMMENTS: MODERATE-HIGH CONFIDENCE IN WINDS.
GUSTS AROUND 20 KT POSSIBLE BEFORE 14Z.
KEWR FCSTER COMMENTS: MODERATE-HIGH CONFIDENCE IN WINDS.
GUSTS AROUND 20 KT POSSIBLE BEFORE 14Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
OUTLOOK FOR 12Z THURSDAY-SUNDAY...
.THU...VFR.
.FRI-SUN...MVFR OR LOWER POSSIBLE IN RAIN.
&&
.MARINE...
FORECAST APPEARS ON TRACK...WITH MINOR ADJUSTMENT MADE TO THE
GRIDS FOR THIS MORNING TO REFLECT LATEST TRENDS IN OBSERVATIONS
AND GUIDANCE.
GUSTS TO 25 KT EXPECTED ON ALL WATERS TODAY...THEN ON THE COASTAL
OCEAN AND EASTERN WATERS TONIGHT...WITH A 35 KT LOW LEVEL JET
CROSSING THE COASTAL OCEAN AND EASTERN WATERS. HAVE ISSUED A SMALL
CRAFT ADVISORY FOR ALL WATERS FOR TODAY...AND CONTINUED IT FOR THE
SOUTH SHORE BAYS THROUGH THIS EVENING...AND FOR THE COASTAL OCEAN
WATERS AND EASTERN SOUND/BAYS THROUGH TONIGHT.
SCA LEVEL SEAS SHOULD CONTINUE INTO THURSDAY...LINGERING LONGER
OVER THE EASTERN COASTAL OCEAN ZONES. CONFIDENCE THOUGH IS NOT
QUITE HIGH ENOUGH TO EXTEND THE SCA THERE AT THIS TIME. ON THE
REMAINDER OF THE WATERS SUB-SCA CONDITIONS ARE EXPECTED ON THURSDAY.
CONDITIONS WILL REMAIN BELOW SCA LEVELS THU NIGHT-SAT. NE FLOW WILL
INTENSIFY FOR THE SECOND HALF OF THE WEEKEND AS LOW PRES DEEPENS
NEAR THE WATERS. SCA CONDITIONS WILL BE POSSIBLE
SUNDAY...ESPECIALLY ON THE ERN OCEAN.
&&
.HYDROLOGY...
LESS THAN 1/4 INCH OF BASIN AVERAGE QPF IS EXPECTED THROUGH
TONIGHT...FOLLOWED BY DRY CONDITIONS THURSDAY.
WIDESPREAD SIGNIFICANT PRECIPITATION IS NOT EXPECTED THU NIGHT-TUE.
&&
.TIDES/COASTAL FLOODING...
FULL MOON ON SAT...SO SOME MINOR TIDAL FLOODING COULD BE POSSIBLE
WITH PERSISTENT E TO NE FLOW. MOST SUSCEPTIBLE SPOT WOULD BE THE S
SHORE BAYS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ335-
338.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ330-340-
350-353-355.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ345.
&&
$$
SYNOPSIS...JMC/MALOIT
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...JMC
AVIATION...GOODMAN/24
MARINE...JMC/MALOIT
HYDROLOGY...JMC/MALOIT
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
814 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE WEST TODAY...THEN CROSSES THE
TRI-STATE TONIGHT...FOLLOWED BY HIGH PRESSURE BUILDING IN THROUGH
THURSDAY NIGHT...AS THE FRONT STALLS TO OUR SOUTH. A NEARLY
STATIONARY FRONT OFFSHORE WILL RESULT IN UNSETTLED WEATHER FRIDAY
INTO EARLY NEXT WEEK. FAIR WEATHER THEN ATTEMPTS TO ESTABLISH
ITSELF BY TUESDAY AS WEAK HIGH PRESSURE BUILDS IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST RADAR TRENDS AND 6Z/7Z HRRR 6Z NAM/GFS AND 3Z SREF ALL
SUGGEST THAT AFTER CURRENT BATCH OF SPOTTY LIGHT RAIN MOVES
THROUGH IN THE NEXT HOUR...THAT THE REMAINDER OF THE MORNING
SHOULD BE BASICALLY DRY...ESPECIALLY OVER THE SE 2/3 OF THE CWA.
WILL CONTINUE TO MONITOR ONGOING PRECIPITATION OVER S CENTRAL
PA...BUT IT APPEARS TO BE FALLING APART AS IT HEADS ENE...AND
GIVEN MARINE AIRMASS IN PLACE EAST OF THE APPALACHIANS...THIS
TREND SHOULD CONTINUE. AS A RESULT HAVE LOWERED POPS FOR MOST OF
THE CWA THIS MORNING BASED ON A BLEND OF 7Z HRRR/6Z NAM/3Z SREF POPS.
REMAINDER OF FORECAST APPEARS ON TRACKS...WITH MINOR ADJUSTMENT
MADE TO THE GRIDS FOR THIS MORNING TO REFLECT LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE.
SPOTTY LIGHT RAIN THIS MORNING IN RESPONSE TO 850 WARM FRONT
LIFTING THROUGH THE AREA. SHOWERS LIKELY ACROSS NW 1/3 OF THE CWA
WITH SCT SHRA ELSEWHERE BY LATE AFTERNOON AHEAD OF A COLD
FRONT...AND WITH A PASSING 700 HPA VORTICITY MAXIMUM. SHOULD HAVE
MODEST INSTABILITY BY LATE AFTERNOON - 100-500 J/KG OF CAPE - TO
WARRANT MENTION OF ISOLD TSTMS AS WELL. 30-40 KT OF BULK SHEAR
WITH THE MEAGER CAPE WILL LIKELY SHEAR OUT STORMS BEFORE THEY CAN
BECOME STRONG TO SEVERE...BUT WITH A 35 KT LOW LEVEL JET THE
POSSIBILITY OF A SEVERE STORM LATE IN THE AFTERNOON CANNOT BE
COMPLETELY RULED OUT.
FOR HIGHS TODAY USED A BLEND OF MIXING DOWN FROM 950 HPA NEAR THE
COAST...900 HPA INLAND...NAM 2-METER TEMPERATURES AND MAV/MET
GUIDANCE. EXPECT READINGS TO BE 5 DEGREES OR SO ABOVE NORMAL.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC BEACHES TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
700 HPA TROUGH ALONG WITH SURFACE-850 COLD FRONT PASSES THROUGH
TONIGHT. TAPER LIKELY POPS OFF TO SLIGHT CHANCE FROM NW TO SE
WITH ITS PASSAGE. LIKE LATE THIS AFTERNOON...THE COMBINATION OF
MEAGER CAPES AND A STRONG LOW LEVEL JET WARRANT A SLIGHT CHANCE OF
THUNDER...WITH A SEVERE STORM OR TWO NOT COMPLETELY OUT OF THE
QUESTION - BUT VERY UNLIKELY. USED A BLEND OF MAV/MET GUIDANCE
WITH NAM 2-METER TEMPERATURES FOR LOWS...WITH VALUES 5-10 DEGREES
ABOVE NORMAL.
PASSING 500 HPA TROUGH WARRANTS SLIGHT CHANCE POPS EARLY...BUT FOR
THE MOST PART EXPECT THURSDAY TO BE DRY WITH DECREASING LOUD COVER
AS HEIGHTS RISE IN THE WAVE OF THE SYSTEM LIFTING NE INTO THE
CANADIAN MARITIMES. FOR HIGHS USED A BLEND OF MIXING DOWN FROM 850
HPA WITH MAV/MET GUIDANCE AND NAM 2-METER TEMPERATURES.
FORECASTING VALUES TO BE A FEW DEGREES ABOVE NORMAL AS A
RESULT...AS COOLER TEMPERATURES IN THE LOW LEVELS DO NOT PUSH IN
UNTIL LATE IN THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
LATEST DATA BRINGS INCREASING CONFIDENCE IN A RAINY PERIOD FRI THROUGH
THE WEEKEND.
00Z MODELS SHOW THAT ACTIVE WEATHER WILL FOLLOW ROUGHLY IN THE VICINITY
OF THE 10C H85 ISOTHERM. THIS HAPPENS TO BE OVER OR NEAR THE CWA
THIS WEEKEND. BEFORE THAT HOWEVER...SOME UNCERTAINTY WITH RESPECT
TO PRECIPITATION CHANCES THU NIGHT AND FRI.
NAM AND ECMWF WERE THE FASTEST WITH THE PRECIPITATION DURING THAT
PERIOD. THIS IS THE TIMING FAVORED BY MODEL DIAGNOSTICS. THE GFS
KICKS IN AROUND 18Z FRI. TRENDED THE FCST TOWARDS THE FASTER
PROGS...WHICH TRANSLATES TO INCREASING CHANCES FOR LGT RAIN
THROUGH THE NIGHT.
CHANCES FOR RAIN FRI. MAINTAINED THE 40 POPS BECAUSE THE NAM SHOWED
MARGINAL PRECIPITATION AMOUNTS FOR MEASURABLE. IF THE MODEL CONSENSUS
CONTINUES HOWEVER...POPS WILL NEED TO BE RAISED SIGNIFICANTLY.
MID LEVEL MOISTURE CONVERGENCE ZONE REMAINS OVER THE CWA THIS
WEEKEND. IN ADDITION...H5 TROUGH WILL PRESENT THE OPPORTUNITY FOR
COASTAL CYCLOGENESIS. GFS AND ECMWF BOTH POINT TO THIS OCCURRING...
ALTHOUGH THE DETERMINISTIC SOLUTIONS ARE NOT EXACTLY ON THE SAME
SCHEDULE. OUTSIDE OF THIS LOW PRES DEVELOPMENT...PERIODS OF LGT
RAIN POSSIBLE DUE TO THE MOISTURE CONVERGENCE ALONE. POPS HAVE
THEREFORE BEEN INCREASED BY 10 PCT TO HIGH CHANCE.
IT LOOKED LIKE THE MODELS CLEARED THINGS OUT FOR MON...BUT THE 00Z
ECMWF ROLLED IN WET. FORCED TO MAINTAIN CHANCE SHRA FOR THIS PERIOD.
BEHAVIOR OF THE H5 CLOSED LOW IS THE MAIN DRIVER OF THE FCST. IT
SHOULD BE NOTED THAT THE 00Z ECMWF IS ABOUT 10DAM DEEPER THAN THE
GFS ENSEMBLE MEMBERS...BUT CLOSE TO THE CLUSTERING POSITION-WISE.
THE GFS IS DEEPER THAN THE ECMWF AND NE OF THE ENSEMBLE DATA...SO
APPEARS TO BE EVEN FURTHER AWAY FROM THE CONSENSUS. FCST IS
UNCERTAIN IN THIS TIME PERIOD.
IT DOES APPEAR SUPPRESSION OF HEIGHTS OVER THE CENTRAL CONUS TAKES
PLACE ON TUE...CHANGING THE UPPER LEVEL PATTERN. THEREFORE KEPT A DRY
FCST FOR TUE.
TEMPS THU NIGHT-FRI A BLEND OF THE BIAS CORRECTED GFS
MOS(BCGMOS)/MET/MAV. THE REMAINDER OF THE FCST A BLEND OF THE
BCGMOS/MEN/ECE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE THROUGH DURING THE EVENING HOURS.
MAINLY VFR CONDS THROUGH THE PERIOD. CIGS/VSBY MAY BRIEFLY DROP
BETWEEN 2-3K FT AND 5SM RESPECTIVELY IN ANY SHOWERS...BUT HIGHEST
PROBABILITY IS AT KSWF AND MAINLY WITH THE FRONTAL PASSAGE THIS
EVENING. IF WINDS DECOUPLE TONIGHT AT KSWF...3-5SM VSBY IS
POSSIBLE. LOW CONFIDENCE AS DRIER AIR BEHIND THE FRONT WOULD BE
WORKING IN AT THE SAME TIME.
A MODERATE S/SW FLOW WILL CONTINUE THROUGH THE DAY. MODELS ARE IN
GOOD AGREEMENT THAT WINDS ALOFT OVER WESTERN ZONES DECREASE THIS
MORNING AND THEN INCREASE AGAIN THIS AFTN. SOME
UNCERTAINTY HOW HIGH GUSTS THEY WILL BE. THEY COULD ALSO BE A FEW
KT HIGHER BETWEEN 17Z AND 21Z AND MAY LINGER A FEW HOURS LONGER
THAN CURRENTLY FORECAST.
AREA OF SHOWERS ACROSS CENTRAL PA TRACKING ENE IS TIMED TO REACH
NYC TERMINALS BETWEEN 15Z AND 17Z IF THEY HOLD TOGETHER. AS THE
COLD FRONT APPROACHES LATE THIS AFTN/EARLY EVE SCT TO NUMEROUS
SHOWERS AND POSSIBLY AN ISOLD RUMBLE OF THUNDER WILL DEVELOP. WEAK
INSTABILITY AND STRONG WINDS ALOFT COULD PRODUCE SOME GUSTY WINDS
WITH THESE SHOWERS/TSTM. POSSIBLE GUSTS UP TO 30 KT. WIND SHIFT TO
THE W BEHIND PRE-FRONTAL TROUGH BETWEEN 02Z AND 06Z...THEN TO THE
NW BETWEEN 06Z AND 10Z.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE IN WINDS. GUSTS
AROUND 20 KT POSSIBLE BETWEEN 11Z AND 14Z.
KLGA FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE IN WINDS. GUSTS
AROUND 20 KT POSSIBLE BETWEEN 11Z AND 14Z.
KEWR FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE IN WINDS. GUSTS
AROUND 20 KT POSSIBLE BETWEEN 11Z AND 14Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
OUTLOOK FOR 12Z THURSDAY-SUNDAY...
.THU...VFR.
.FRI-SUN...MVFR OR LOWER POSSIBLE IN RAIN.
&&
.MARINE...
FORECAST APPEARS ON TRACKS...WITH MINOR ADJUSTMENT
MADE TO THE GRIDS FOR THIS MORNING TO REFLECT LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE.
GUSTS TO 25 KT EXPECTED ON ALL WATERS TODAY...THEN ON THE COASTAL
OCEAN AND EASTERN WATERS TONIGHT...WITH A 35 KT LOW LEVEL JET
CROSSING THE COASTAL OCEAN AND EASTERN WATERS. HAVE ISSUED A SMALL
CRAFT ADVISORY FOR ALL WATERS FOR TODAY...AND CONTINUED IT FOR THE
SOUTH SHORE BAYS THROUGH THIS EVENING...AND FOR THE COASTAL OCEAN
WATERS AND EASTERN SOUND/BAYS THROUGH TONIGHT.
SCA LEVEL SEAS SHOULD CONTINUE INTO THURSDAY...LINGERING LONGER
OVER THE EASTERN COASTAL OCEAN ZONES. CONFIDENCE THOUGH IS NOT
QUITE HIGH ENOUGH TO EXTEND THE SCA THERE AT THIS TIME. ON THE
REMAINDER OF THE WATERS SUB-SCA CONDITIONS ARE EXPECTED ON THURSDAY.
CONDITIONS WILL REMAIN BELOW SCA LEVELS THU NIGHT-SAT. NE FLOW WILL
INTENSIFY FOR THE SECOND HALF OF THE WEEKEND AS LOW PRES DEEPENS
NEAR THE WATERS. SCA CONDITIONS WILL BE POSSIBLE
SUNDAY...ESPECIALLY ON THE ERN OCEAN.
&&
.HYDROLOGY...
LESS THAN 1/4 INCH OF BASIN AVERAGE QPF IS EXPECTED THROUGH
TONIGHT...FOLLOWED BY DRY CONDITIONS THURSDAY.
WIDESPREAD SIGNIFICANT PRECIPITATION IS NOT EXPECTED THU NIGHT-TUE.
&&
.TIDES/COASTAL FLOODING...
FULL MOON ON SAT...SO SOME MINOR TIDAL FLOODING COULD BE POSSIBLE
WITH PERSISTENT E TO NE FLOW. MOST SUSCEPTIBLE SPOT WOULD BE THE S
SHORE BAYS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ335-
338.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ330-340-
350-353-355.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ345.
&&
$$
SYNOPSIS...JMC/MALOIT
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...JMC
AVIATION...24
MARINE...JMC/MALOIT
HYDROLOGY...JMC/MALOIT
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS ALBANY NY
711 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT WILL BRING SOME SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS TODAY INTO EARLY THIS EVENING FOR EASTERN NEW YORK
AND WESTERN NEW ENGLAND. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM
THE GREAT LAKES REGION ON THURSDAY WITH FAIR AND DRY WEATHER. AS
THE ANTICYCLONE MOVES OFF THE NEW ENGLAND COAST THURSDAY NIGHT...A
FRONTAL BOUNDARY MAY MOVE NORTHWARD FROM THE MID ATLANTIC REGION
WITH SOME RAIN PREDOMINANTLY SOUTH AND EAST OF THE CAPITAL
DISTRICT TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 655 AM EDT...AN AREA OF SCATTERED SHOWERS OR LIGHT RAIN CONTINUES
OVER THE ERN NY AND WRN NEW ENGLAND CORRIDOR EARLY THIS MORNING.
UPSTREAM RADAR TRENDS SHOW A BREAK IN THE PCPN SHIELD...AS THE
LATEST RUC40 SHOWS A SHORT-WAVE MOVING ACROSS NEW ENGLAND. THE
FRONTAL BOUNDARY IS STILL BACK OVER THE GREAT LAKES REGION AND
NORTH OF THE ST LAWRENCE RIVER VALLEY. THE LULL IN THE PCPN IS
SUPPORTED BY THE 3KM HRRR TOWARDS LUNCHTIME.
THE COLD FRONT BEGINS TO SAG S/SE DURING THE AFTERNOON WITH
ANOTHER IMPULSE IN THE W/SW FLOW INTERACTING WITH IT. AFTER A LULL
IN THE PCPN...WE ARE EXPECTING SHOWERS TO REKINDLE IN THE LATE
MORNING AND EARLY PM. PWATS WILL BE AROUND AN INCH TO AN INCH A
THIRD OVER THE REGION. THE IMMENSE AMOUNT OF CLOUD COVER /CLOUDY OR
MOSTLY CLOUD CONDITIONS ARE FORECASTED/ SHOULD PREVENT SIGNIFICANT
SFC HEATING AND DESTABILIZATION. SBCAPES ARE GENERALLY UNDER A
FEW HUNDRED J/KG FROM BOTH THE NAM AND GFS. THERE IS A NARROW
RIBBON OF NEGATIVE SHOWALTER VALUES OR BEST LIFTED INDICES AHEAD
OF THE BOUNDARY LATE IN THE AFTERNOON FROM THE CAPITAL
REGION...CNTRL MOHAWK VALLEY...AND SRN VT SOUTH AND EAST. MID
LEVEL LAPSE RATES CONTINUE TO BE RATHER WEAK. WE KEPT A SLIGHT CHC
OF THUNDERSTORMS HERE...AND REMOVED THEM TO THE NORTH. POPS WERE
CONTINUED IN THE HIGH CHC AND LIKELY VALUES LATE. THERE IS NOT AN
ANTICIPATION OF ANY SEVERE THUNDERSTORMS TODAY DUE TO THE MEAGER
INSTABILITY AND WEAK LAPSE RATES PROJECTED BY THE GUIDANCE.
HIGHS TODAY WILL RANGE FROM THE MID AND UPPER 60S OVER THE HILLS
AND MTNS...TO MAINLY U60S TO L70S IN THE VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE COLD FRONT MAKES STEADY PROGRESS ACROSS THE REGION
WITH THE NAM BEING MUCH FASTER THAN THE GFS. WE KEPT SLIGHT OR LOW
CHANCE OF SHOWERS AROUND UNTIL MIDNIGHT TO 0600 UTC...SINCE THE
UPPER LEVEL TROUGH AXIS STILL LINGERS UPSTREAM EVEN ON THE NAM.
HIGH PRESSURE STARTS TO BUILD IN QUICKLY FROM S-CNTRL ONTARIO AND
THE GREAT LAKES REGION. SOME FOG MAY FORM IN THE FAVORED AREAS OF
THE LAKE GEORGE REGION...SRN VT...AND THE BERKSHIRES. SOME PATCHY
FOG WAS ADDED TO RECENT WET GROUNDS...AND CLEARING SKIES. LOWS
WILL GENERALLY BE IN THE U40S TO M50S FROM THE MOHAWK VALLEY...AND
CAPITAL REGION SOUTH AND EAST WITH U30S TO M40S NORTH AND WEST.
SEE THE HYDRO SECTION FOR QPF AMOUNTS.
THURSDAY...HIGH PRESSURE BUILDS IN FOR A FINE EARLY FALL DAY WITH
PARTLY TO MOSTLY SUNNY CONDITIONS DUE TO THE SUBSIDENCE WITH THE
ANTICYCLONE. WE LEANED A LITTLE CLOSER TO THE COOLER MAVMOS MAX
TEMPS WITH H850 TEMPS OF +2C TO +6C. MIXING SHOULD BE FROM H800 TO
H850. MAX TEMPS WILL GENERALLY BE IN THE 60S WITH SOME U50S OVER
THE SRN DACKS...SRN GREENS...AND ERN CATSKILLS.
THURSDAY NIGHT...THIS WILL BE INTERESTING WITH HIGH PRESSURE
SHIFTING EASTWARD OFF THE COAST...AND THE OLD FRONTAL BOUNDARY
BENDING NORTHWARD FROM THE MID ATLANTIC REGION...AND OHIO VALLEY.
THE NRN ZONES COULD BE MOSTLY CLEAR AND CALM WITH A POTENTIAL
FROST OR FREEZE. FROM THE CAPITAL REGION SOUTH...MID AND HIGH CLOUDS
WILL INCREASE. THE GUIDANCE HAS BACKED OFF A LITTLE...BUT FROM KPOU
SOUTH AND EAST SOME LIGHT RAIN MAY POP UP WITH INCREASING LOW
LEVEL THERMAL ADVECTION IN ADVANCE OF THE FRONT...AND WITH A
SHORT- WAVE RIPPLING ALONG. LOWS WILL RANGE FROM THE U20S TO M30S
NORTH OF THE CAPITAL REGION TO U30S TO M40S SOUTH AND EAST.
FRIDAY...LOCATIONS MAINLY SOUTH AND EAST OF THE CAPITAL REGION MAY
SEE PERIODS OF LIGHT RAIN EVOLVE INTO A STEADIER RAIN BY AFTERNOON
BASED ON THE NAM/EC/GFS/CAN GUIDANCE. THERE WILL LIKELY BE A SHARP
CUTOFF FROM THE RAINFALL...AS WEAK LOW PRESSURE MOVES SOUTH OF LONG
ISLAND. SLIGHT CHANCES OF RAINFALL WERE BROUGHT UP TO THE CAPITAL
REGION LATE IN THE DAY. A BROAD CUTOFF LOW WILL BE DESCENDING
EQUATORWARD FROM JAMES BAY. MORE SUNSHINE MAY OCCUR NORTH OF THE
TRI CITES...AS TEMPS WILL RUN NEAR NORMAL TO CLOSE THE WORK WEEK
WITH U50S TO U60S OVER THE REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
UNSETTLED WEATHER IS EXPECTED FOR MUCH OF THE LONG TERM
PERIOD...ALTHOUGH MUCH UNCERTAINTY REMAINS IN TERMS OF TIMING OF
PRECIPITATION AS WELL AS WHICH FORECAST PERIODS HAVE THE GREATEST
PROBABILITY OF PRECIPITATION. THE FA IS EXPECTED TO BE IMPACTED BY A
LARGE UPPER CLOSED LOW INITIALLY OVER CANADA AS WELL AS A SERIES OF
COASTAL SYSTEMS AT THE SURFACE LIFTING NORTHEAST FROM NEAR DELMARVA
FRIDAY NIGHT...PASSING EAST OF THE JERSEY COAST AND SOUTHEAST OF
LONG ISLAND ON SATURDAY INTO SUNDAY...AND FINALLY OUT TO SEA ON
MONDAY. MEANWHILE...THE UPPER CLOSED LOW IS EXPECTED TO BE ANYWHERE
FROM SOUTHEAST OF JAMES BAY TO UPPER MICHIGAN SATURDAY MORNING AND
THEN GRADUALLY SLIDE SOUTHWEST INTO THE EASTERN GREAT LAKES OR OHIO
VALLEY ON SUNDAY BEFORE LIFTING NORTHEAST ON MONDAY INTO THE EASTERN
SAINT LAWRENCE VALLEY BY MONDAY NIGHT. THE GFS IS THE FARTHEST EAST
WITH THIS FEATURE AND HAS THE EARLIEST DEPARTURE AWAY FROM THE
REGION ON MONDAY...WHILE THE GGEM IS THE FARTHEST WEST AND SLOWEST
WITH THE ECMWF TRACK IN BETWEEN.
AT THIS POINT PLAN ON GOING WITH MAINLY CHANCE POPS FROM FRIDAY
NIGHT THROUGH MONDAY AND THEN MAINLY DRY WEATHER MONDAY NIGHT AND
TUESDAY AS THE NOSE OF A RIDGE OF HIGH PRESSURE GRADUALLY BUILDS
INTO THE NORTHEAST ON TUESDAY. ALSO EXPECT A CONSIDERABLE AMOUNT OF
CLOUD COVER FROM FRIDAY NIGHT INTO MONDAY MORNING ALTHOUGH CANNOT
RULE OUT SOME BREAKS IN THE CLOUD COVER AS WELL AS PCPN ACRS
NORTHWEST PORTION OF FA ESPECIALLY DURING THE SATURDAY NIGHT AND
SUNDAY TIME FRAME AS A DRY SLOT MAY DEVELOP BETWEEN SURFACE LOW
PASSING SOUTHEAST AND UPPER LOW STILL TO THE WEST OR SOUTHWEST.
HIGHS ARE GENERALLY EXPECTED TO BE IN THE UPPER 50S TO UPPER 60S
SATURDAY THROUGH MONDAY WITH THE COOLEST OF THE THREE DAYS LIKELY TO
BE SATURDAY. HIGHS ON TUESDAY SHOULD REBOUND TO THE 60S TO LOWER 70S
WITH MORE SUNSHINE. LOWS ARE EXPECTED TO BE IN THE MID 40S TO MID
50S FRIDAY NIGHT THROUGH SUNDAY NIGHT WITH LOWS IN THE 40S TO AROUND
50 ON MONDAY NIGHT WITH MORE BREAKS IN THE CLOUD COVER.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
MAINLY MVFR CONDITIONS WILL PREVAIL AT THE TAF SITES FOR MUCH OF
THE TAF PERIOD ENDING AT 12Z THURSDAY...THE EXCEPTIONS WILL BE
SOME IFR CONDITIONS AT KGFL AND SOME VFR CONDITIONS AT KPOU THIS MORNING.
THE FIRST BAND OF SHOWERS HAS ALL BUT ENDED ACRS THE AREAS AND
AFTER A LULL THIS MORNING MORE SHOWERS ARE EXPECTED THIS AFTERNOON
BEFORE THE PASSAGE OF A COLD FRONT THIS EVENING. ANY LINGERING
SHOWERS WILL END DURING THE EVENING WITH CIGS STILL REMAINING
MAINLY MVFR FOR THE REMAINDER OF TONIGHT.
WINDS WILL BE SOUTH TO SOUTHWEST AT 5-8 KTS WITH WINDS THEN
SHIFTING TO THE NORTH-NORTHWEST AT 3-6 KTS DURING THE EVENING IN
THE WAKE OF THE COLD FRONT.
OUTLOOK...
THU-FRI...VFR. CHC MVFR KPOU W/CHC SHWRS ON FRI.
SAT-SUN...MAINLY VFR. CHC -SHRA.
&&
.FIRE WEATHER...
A COLD FRONT WILL BRING SOME RAIN AND A SLIGHT CHANCE OF
THUNDERSTORMS TODAY INTO EARLY THIS EVENING FOR EASTERN NEW YORK AND
WESTERN NEW ENGLAND. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM THE
GREAT LAKES REGION ON THURSDAY WITH FAIR AND DRY WEATHER.
UNSETTLED WEATHER MAY RETURN FRIDAY INTO THE WEEKEND FOR PARTS OF
THE REGION.
FIRE WEATHER PROBLEMS CONTINUE TO BE NON EXISTENT IN THE REGION
WITH A WETTING RAIN CONTINUING TODAY INTO TONIGHT. RH VALUES WILL
REMAIN HIGH TODAY AND TONIGHT. EXPECT THEM TO LOWER IN THE DRIER
AIR MASS BY THURSDAY AFTERNOON TO 35 TO 50 PERCENT.
THE WINDS WILL BE FROM THE SOUTH OR SOUTHWEST AT 5 TO 15 MPH
TODAY...AND THEN SHIFT TO THE WEST OF NORTHWEST AT 5 TO 10 MPH
TONIGHT. THURSDAY WILL FEATURE NORTH OR NORTHWEST WINDS OF 10 TO
15 MPH.
&&
.HYDROLOGY...
NO WIDESPREAD PROBLEMS ARE EXPECTED IN THE ALY HYDRO SERVICE AREA
THE NEXT 5 DAYS.
THE COLD FRONT AND UPPER LEVEL DISTURBANCE TODAY INTO TONIGHT WILL
BRING AREAL RAINFALL AMOUNTS RANGING FROM TWO TENTHS TO A HALF AN
INCH OR SO...THOUGH ANY LOCATION THAT MIGHT GET CAUGHT UNDER A
THUNDERSTORM COULD RECEIVE AROUND AN INCH. RIVERS...
STREAMS...CREEKS...BROOKS AND OTHER BODIES OF WATER MAY HAVE
MINIMAL RISES AT BEST. THE 06Z HPC QPF WAS USED CLOSELY PRIOR TO
THURSDAY.
HIGH PRESSURE WILL BRING DRY WEATHER TO MOST OF THE HSA THURSDAY
AND THURSDAY NIGHT.
A FRONTAL BOUNDARY LIFTING NORTHWARD FROM THE MID ATLANTIC
REGION...AND A CUTOFF LOW MAY BRING PERIODS OF SHOWERS AND RAIN TO
THE HSA FRIDAY INTO THE WEEKEND. THE NWP GUIDANCE IS HIGHLY
VARIABLE ON THE EVOLUTION OF WHAT HAPPENS THIS WEEKEND. AT THIS
POINT LIGHT TO MODERATE RAINFALL IS GENERALLY ANTICIPATED FRIDAY
INTO SATURDAY FROM THE CAPITAL REGION SOUTH AND EAST /A FEW TENTHS
OF AN INCH TO THREE QUARTER OF AN INCH/...BUT A STEADIER MODERATE
RAINFALL MAY OCCUR ESPECIALLY SOUTH OF THE CAPITAL REGION...AND
EAST OF THE HUDSON VALLEY LATER IN THE WEEKEND. THE PLACEMENT OF THE
RAINFALL...AND HOW MUCH QPF OCCURS WILL DEPEND ON THE LOCATIONS OF
THE CUTOFF LOW. TRENDS WILL CONTINUE TO BE FOLLOWED OVER THE NEXT
FEW DAYS.
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.
&&
.EQUIPMENT...
THE KENX DOPPLER RADAR WILL BE UNDERGOING REPAIRS AS ADDITIONAL
PARTS ARE ON ORDER. THE KENX RADAR WILL CONTINUE TO BE DOWN AND IS
EXPECTED TO BE BACK IN SERVICE BY MID AFTERNOON ON WEDNESDAY
SEPTEMBER 26TH 2012. WE APOLOGIZE FOR ANY INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...WASULA
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
657 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT WILL BRING SOME SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS TODAY INTO EARLY THIS EVENING FOR EASTERN NEW YORK
AND WESTERN NEW ENGLAND. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM
THE GREAT LAKES REGION ON THURSDAY WITH FAIR AND DRY WEATHER. AS
THE ANTICYCLONE MOVES OFF THE NEW ENGLAND COAST THURSDAY NIGHT...A
FRONTAL BOUNDARY MAY MOVE NORTHWARD FROM THE MID ATLANTIC REGION
WITH SOME RAIN PREDOMINANTLY SOUTH AND EAST OF THE CAPITAL
DISTRICT TO CLOSE THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 655 AM EDT...AN AREA OF SCATTERED SHOWERS OR LIGHT RAIN CONTINUES
OVER THE ERN NY AND WRN NEW ENGLAND CORRIDOR EARLY THIS MORNING.
UPSTREAM RADAR TRENDS SHOW A BREAK IN THE PCPN SHIELD...AS THE
LATEST RUC40 SHOWS A SHORT-WAVE MOVING ACROSS NEW ENGLAND. THE
FRONTAL BOUNDARY IS STILL BACK OVER THE GREAT LAKES REGION AND
NORTH OF THE ST LAWRENCE RIVER VALLEY. THE LULL IN THE PCPN IS
SUPPORTED BY THE 3KM HRRR TOWARDS LUNCHTIME.
THE COLD FRONT BEGINS TO SAG S/SE DURING THE AFTERNOON WITH
ANOTHER IMPULSE IN THE W/SW FLOW INTERACTING WITH IT. AFTER A LULL
IN THE PCPN...WE ARE EXPECTING SHOWERS TO REKINDLE IN THE LATE
MORNING AND EARLY PM. PWATS WILL BE AROUND AN INCH TO AN INCH A
THIRD OVER THE REGION. THE IMMENSE AMOUNT OF CLOUD COVER /CLOUDY OR
MOSTLY CLOUD CONDITIONS ARE FORECASTED/ SHOULD PREVENT SIGNIFICANT
SFC HEATING AND DESTABILIZATION. SBCAPES ARE GENERALLY UNDER A
FEW HUNDRED J/KG FROM BOTH THE NAM AND GFS. THERE IS A NARROW
RIBBON OF NEGATIVE SHOWALTER VALUES OR BEST LIFTED INDICES AHEAD
OF THE BOUNDARY LATE IN THE AFTERNOON FROM THE CAPITAL
REGION...CNTRL MOHAWK VALLEY...AND SRN VT SOUTH AND EAST. MID
LEVEL LAPSE RATES CONTINUE TO BE RATHER WEAK. WE KEPT A SLIGHT CHC
OF THUNDERSTORMS HERE...AND REMOVED THEM TO THE NORTH. POPS WERE
CONTINUED IN THE HIGH CHC AND LIKELY VALUES LATE. THERE IS NOT AN
ANTICIPATION OF ANY SEVERE THUNDERSTORMS TODAY DUE TO THE MEAGER
INSTABILITY AND WEAK LAPSE RATES PROJECTED BY THE GUIDANCE.
HIGHS TODAY WILL RANGE FROM THE MID AND UPPER 60S OVER THE HILLS
AND MTNS...TO MAINLY U60S TO L70S IN THE VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...THE COLD FRONT MAKES STEADY PROGRESS ACROSS THE REGION
WITH THE NAM BEING MUCH FASTER THAN THE GFS. WE KEPT SLIGHT OR LOW
CHANCE OF SHOWERS AROUND UNTIL MIDNIGHT TO 0600 UTC...SINCE THE
UPPER LEVEL TROUGH AXIS STILL LINGERS UPSTREAM EVEN ON THE NAM.
HIGH PRESSURE STARTS TO BUILD IN QUICKLY FROM S-CNTRL ONTARIO AND
THE GREAT LAKES REGION. SOME FOG MAY FORM IN THE FAVORED AREAS OF
THE LAKE GEORGE REGION...SRN VT...AND THE BERKSHIRES. SOME PATCHY
FOG WAS ADDED TO RECENT WET GROUNDS...AND CLEARING SKIES. LOWS
WILL GENERALLY BE IN THE U40S TO M50S FROM THE MOHAWK VALLEY...AND
CAPITAL REGION SOUTH AND EAST WITH U30S TO M40S NORTH AND WEST.
SEE THE HYDRO SECTION FOR QPF AMOUNTS.
THURSDAY...HIGH PRESSURE BUILDS IN FOR A FINE EARLY FALL DAY WITH
PARTLY TO MOSTLY SUNNY CONDITIONS DUE TO THE SUBSIDENCE WITH THE
ANTICYCLONE. WE LEANED A LITTLE CLOSER TO THE COOLER MAVMOS MAX
TEMPS WITH H850 TEMPS OF +2C TO +6C. MIXING SHOULD BE FROM H800 TO
H850. MAX TEMPS WILL GENERALLY BE IN THE 60S WITH SOME U50S OVER
THE SRN DACKS...SRN GREENS...AND ERN CATSKILLS.
THURSDAY NIGHT...THIS WILL BE INTERESTING WITH HIGH PRESSURE
SHIFTING EASTWARD OFF THE COAST...AND THE OLD FRONTAL BOUNDARY
BENDING NORTHWARD FROM THE MID ATLANTIC REGION...AND OHIO VALLEY.
THE NRN ZONES COULD BE MOSTLY CLEAR AND CALM WITH A POTENTIAL
FROST OR FREEZE. FROM THE CAPITAL REGION SOUTH...MID AND HIGH CLOUDS
WILL INCREASE. THE GUIDANCE HAS BACKED OFF A LITTLE...BUT FROM KPOU
SOUTH AND EAST SOME LIGHT RAIN MAY POP UP WITH INCREASING LOW
LEVEL THERMAL ADVECTION IN ADVANCE OF THE FRONT...AND WITH A
SHORT- WAVE RIPPLING ALONG. LOWS WILL RANGE FROM THE U20S TO M30S
NORTH OF THE CAPITAL REGION TO U30S TO M40S SOUTH AND EAST.
FRIDAY...LOCATIONS MAINLY SOUTH AND EAST OF THE CAPITAL REGION MAY
SEE PERIODS OF LIGHT RAIN EVOLVE INTO A STEADIER RAIN BY AFTERNOON
BASED ON THE NAM/EC/GFS/CAN GUIDANCE. THERE WILL LIKELY BE A SHARP
CUTOFF FROM THE RAINFALL...AS WEAK LOW PRESSURE MOVES SOUTH OF LONG
ISLAND. SLIGHT CHANCES OF RAINFALL WERE BROUGHT UP TO THE CAPITAL
REGION LATE IN THE DAY. A BROAD CUTOFF LOW WILL BE DESCENDING
EQUATORWARD FROM JAMES BAY. MORE SUNSHINE MAY OCCUR NORTH OF THE
TRI CITES...AS TEMPS WILL RUN NEAR NORMAL TO CLOSE THE WORK WEEK
WITH U50S TO U60S OVER THE REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
UNSETTLED WEATHER IS EXPECTED FOR MUCH OF THE LONG TERM
PERIOD...ALTHOUGH MUCH UNCERTAINTY REMAINS IN TERMS OF TIMING OF
PRECIPITATION AS WELL AS WHICH FORECAST PERIODS HAVE THE GREATEST
PROBABILITY OF PRECIPITATION. THE FA IS EXPECTED TO BE IMPACTED BY A
LARGE UPPER CLOSED LOW INITIALLY OVER CANADA AS WELL AS A SERIES OF
COASTAL SYSTEMS AT THE SURFACE LIFTING NORTHEAST FROM NEAR DELMARVA
FRIDAY NIGHT...PASSING EAST OF THE JERSEY COAST AND SOUTHEAST OF
LONG ISLAND ON SATURDAY INTO SUNDAY...AND FINALLY OUT TO SEA ON
MONDAY. MEANWHILE...THE UPPER CLOSED LOW IS EXPECTED TO BE ANYWHERE
FROM SOUTHEAST OF JAMES BAY TO UPPER MICHIGAN SATURDAY MORNING AND
THEN GRADUALLY SLIDE SOUTHWEST INTO THE EASTERN GREAT LAKES OR OHIO
VALLEY ON SUNDAY BEFORE LIFTING NORTHEAST ON MONDAY INTO THE EASTERN
SAINT LAWRENCE VALLEY BY MONDAY NIGHT. THE GFS IS THE FARTHEST EAST
WITH THIS FEATURE AND HAS THE EARLIEST DEPARTURE AWAY FROM THE
REGION ON MONDAY...WHILE THE GGEM IS THE FARTHEST WEST AND SLOWEST
WITH THE ECMWF TRACK IN BETWEEN.
AT THIS POINT PLAN ON GOING WITH MAINLY CHANCE POPS FROM FRIDAY
NIGHT THROUGH MONDAY AND THEN MAINLY DRY WEATHER MONDAY NIGHT AND
TUESDAY AS THE NOSE OF A RIDGE OF HIGH PRESSURE GRADUALLY BUILDS
INTO THE NORTHEAST ON TUESDAY. ALSO EXPECT A CONSIDERABLE AMOUNT OF
CLOUD COVER FROM FRIDAY NIGHT INTO MONDAY MORNING ALTHOUGH CANNOT
RULE OUT SOME BREAKS IN THE CLOUD COVER AS WELL AS PCPN ACRS
NORTHWEST PORTION OF FA ESPECIALLY DURING THE SATURDAY NIGHT AND
SUNDAY TIME FRAME AS A DRY SLOT MAY DEVELOP BETWEEN SURFACE LOW
PASSING SOUTHEAST AND UPPER LOW STILL TO THE WEST OR SOUTHWEST.
HIGHS ARE GENERALLY EXPECTED TO BE IN THE UPPER 50S TO UPPER 60S
SATURDAY THROUGH MONDAY WITH THE COOLEST OF THE THREE DAYS LIKELY TO
BE SATURDAY. HIGHS ON TUESDAY SHOULD REBOUND TO THE 60S TO LOWER 70S
WITH MORE SUNSHINE. LOWS ARE EXPECTED TO BE IN THE MID 40S TO MID
50S FRIDAY NIGHT THROUGH SUNDAY NIGHT WITH LOWS IN THE 40S TO AROUND
50 ON MONDAY NIGHT WITH MORE BREAKS IN THE CLOUD COVER.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL GRADUALLY GIVE WAY TO MVFR CONDITIONS AT THE
TAF SITES DURING THE REMAINDER OF THE OVERNIGHT PERIOD AS CIGS AND
VSBYS LOWER WITH AN INCREASING PROBABILITY OF SHOWERS.
THE SHOWERS ARE THE RESULT OF A SHORTWAVE TROUGH WHICH WILL
CONTINUE TO ROTATE CLOSER TO THE REGION DURING THE REMAINDER OF
THE OVERNIGHT PERIOD. AS THE PRECIPITATION INCREASES IN COVERAGE
ACRS THE AREA LATER TONIGHT...MVFR CEILINGS AND BORDERLINE MVFR
VISIBILITIES ARE EXPECTED AT ALL TAF SITES.
THE SHOWERS ARE EXPECTED TO DECREASE IN COVERAGE DURING THE
DAYLIGHT HOURS ON WEDNESDAY WITH A RENEWED THREAT FOR ADDITIONAL
SHOWERS THROUGH THE DAY. FOR NOW...WE WILL PLACE VCSH AND AWAIT
FUTURE TRENDS AS EXPECTATIONS THAT MVFR THRESHOLDS COULD BE
SATISFIED. ANY LINGERING SHOWERS WILL END DURING THE EVENING WITH
CIGS STILL REMAINING MAINLY MVFR.
WINDS WILL BE LIGHT AND VARIABLE DURING THE REMAINDER OF THE
OVERNIGHT HOURS EXCEPT SOUTH ARND 8 KTS AT KALB. ON WEDNESDAY
EXPECT SOUTH TO SOUTHWEST WINDS 5-8 KTS WITH WINDS THEN SHIFTING
TO THE NORTH-NORTHWEST AT 3-6 KTS DURING THE EVENING IN THE WAKE
OF THE SHORTWAVE TROUGH.
OUTLOOK...
THU-FRI...VFR. CHC MVFR KPOU W/CHC SHWRS ON FRI.
SAT-SUN...MAINLY VFR. CHC -SHRA.
&&
.FIRE WEATHER...
A COLD FRONT WILL BRING SOME RAIN AND A SLIGHT CHANCE OF
THUNDERSTORMS TODAY INTO EARLY THIS EVENING FOR EASTERN NEW YORK AND
WESTERN NEW ENGLAND. HIGH PRESSURE WILL BRIEFLY BUILD IN FROM THE
GREAT LAKES REGION ON THURSDAY WITH FAIR AND DRY WEATHER.
UNSETTLED WEATHER MAY RETURN FRIDAY INTO THE WEEKEND FOR PARTS OF
THE REGION.
FIRE WEATHER PROBLEMS CONTINUE TO BE NON EXISTENT IN THE REGION
WITH A WETTING RAIN CONTINUING TODAY INTO TONIGHT. RH VALUES WILL
REMAIN HIGH TODAY AND TONIGHT. EXPECT THEM TO LOWER IN THE DRIER
AIR MASS BY THURSDAY AFTERNOON TO 35 TO 50 PERCENT.
THE WINDS WILL BE FROM THE SOUTH OR SOUTHWEST AT 5 TO 15 MPH
TODAY...AND THEN SHIFT TO THE WEST OF NORTHWEST AT 5 TO 10 MPH
TONIGHT. THURSDAY WILL FEATURE NORTH OR NORTHWEST WINDS OF 10 TO
15 MPH.
&&
.HYDROLOGY...
NO WIDESPREAD PROBLEMS ARE EXPECTED IN THE ALY HYDRO SERVICE AREA
THE NEXT 5 DAYS.
THE COLD FRONT AND UPPER LEVEL DISTURBANCE TODAY INTO TONIGHT WILL
BRING AREAL RAINFALL AMOUNTS RANGING FROM TWO TENTHS TO A HALF AN
INCH OR SO...THOUGH ANY LOCATION THAT MIGHT GET CAUGHT UNDER A
THUNDERSTORM COULD RECEIVE AROUND AN INCH. RIVERS...
STREAMS...CREEKS...BROOKS AND OTHER BODIES OF WATER MAY HAVE
MINIMAL RISES AT BEST. THE 06Z HPC QPF WAS USED CLOSELY PRIOR TO
THURSDAY.
HIGH PRESSURE WILL BRING DRY WEATHER TO MOST OF THE HSA THURSDAY
AND THURSDAY NIGHT.
A FRONTAL BOUNDARY LIFTING NORTHWARD FROM THE MID ATLANTIC
REGION...AND A CUTOFF LOW MAY BRING PERIODS OF SHOWERS AND RAIN TO
THE HSA FRIDAY INTO THE WEEKEND. THE NWP GUIDANCE IS HIGHLY
VARIABLE ON THE EVOLUTION OF WHAT HAPPENS THIS WEEKEND. AT THIS
POINT LIGHT TO MODERATE RAINFALL IS GENERALLY ANTICIPATED FRIDAY
INTO SATURDAY FROM THE CAPITAL REGION SOUTH AND EAST /A FEW TENTHS
OF AN INCH TO THREE QUARTER OF AN INCH/...BUT A STEADIER MODERATE
RAINFALL MAY OCCUR ESPECIALLY SOUTH OF THE CAPITAL REGION...AND
EAST OF THE HUDSON VALLEY LATER IN THE WEEKEND. THE PLACEMENT OF THE
RAINFALL...AND HOW MUCH QPF OCCURS WILL DEPEND ON THE LOCATIONS OF
THE CUTOFF LOW. TRENDS WILL CONTINUE TO BE FOLLOWED OVER THE NEXT
FEW DAYS.
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.
&&
.EQUIPMENT...
THE KENX DOPPLER RADAR WILL BE UNDERGOING REPAIRS AS ADDITIONAL
PARTS ARE ON ORDER. THE KENX RADAR WILL CONTINUE TO BE DOWN AND IS
EXPECTED TO BE BACK IN SERVICE BY MID AFTERNOON ON WEDNESDAY
SEPTEMBER 26TH 2012. WE APOLOGIZE FOR ANY INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...WASULA
EQUIPMENT...ALY STAFF
AREA FORECAST DISCUSSION
NWS NEW YORK NY
633 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE WEST TODAY...THEN CROSSES THE
TRI-STATE TONIGHT...FOLLOWED BY HIGH PRESSURE BUILDING IN THROUGH
THURSDAY NIGHT...AS THE FRONT STALLS TO OUR SOUTH. A NEARLY
STATIONARY FRONT OFFSHORE WILL RESULT IN UNSETTLED WEATHER FRIDAY
INTO EARLY NEXT WEEK. FAIR WEATHER THEN ATTEMPTS TO ESTABLISH
ITSELF BY TUESDAY AS WEAK HIGH PRESSURE BUILDS IN.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST RADAR TRENDS AND 6Z/7Z HRRR 6Z NAM/GFS AND 3Z SREF ALL
SUGGEST THAT AFTER CURRENT BATCH OF SPOTTY LIGHT RAIN MOVES
THROUGH IN THE NEXT HOUR...THAT THE REMAINDER OF THE MORNING
SHOULD BE BASICALLY DRY...ESPECIALLY OVER THE SE 2/3 OF THE CWA.
WILL CONTINUE TO MONITOR ONGOING PRECIPITATION OVER S CENTRAL
PA...BUT IT APPEARS TO BE FALLING APART AS IT HEADS ENE...AND
GIVEN MARINE AIRMASS IN PLACE EAST OF THE APPALACHIANS...THIS
TREND SHOULD CONTINUE. AS A RESULT HAVE LOWERED POPS FOR MOST OF
THE CWA THIS MORNING BASED ON A BLEND OF 7Z HRRR/6Z NAM/3Z SREF POPS.
REMAINDER OF FORECAST APPEARS ON TRACKS...WITH MINOR ADJUSTMENT
MADE TO THE GRIDS FOR THIS MORNING TO REFLECT LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE.
SPOTTY LIGHT RAIN THIS MORNING IN RESPONSE TO 850 WARM FRONT
LIFTING THROUGH THE AREA. SHOWERS LIKELY ACROSS NW 1/3 OF THE CWA
WITH SCT SHRA ELSEWHERE BY LATE AFTERNOON AHEAD OF A COLD
FRONT...AND WITH A PASSING 700 HPA VORTICITY MAXIMUM. SHOULD HAVE
MODEST INSTABILITY BY LATE AFTERNOON - 100-500 J/KG OF CAPE - TO
WARRANT MENTION OF ISOLD TSTMS AS WELL. 30-40 KT OF BULK SHEAR
WITH THE MEAGER CAPE WILL LIKELY SHEAR OUT STORMS BEFORE THEY CAN
BECOME STRONG TO SEVERE...BUT WITH A 35 KT LOW LEVEL JET THE
POSSIBILITY OF A SEVERE STORM LATE IN THE AFTERNOON CANNOT BE
COMPLETELY RULED OUT.
FOR HIGHS TODAY USED A BLEND OF MIXING DOWN FROM 950 HPA NEAR THE
COAST...900 HPA INLAND...NAM 2-METER TEMPERATURES AND MAV/MET
GUIDANCE. EXPECT READINGS TO BE 5 DEGREES OR SO ABOVE NORMAL.
THERE IS A MODERATE RISK OF RIP CURRENTS AT ATLANTIC BEACHES TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
700 HPA TROUGH ALONG WITH SURFACE-850 COLD FRONT PASSES THROUGH
TONIGHT. TAPER LIKELY POPS OFF TO SLIGHT CHANCE FROM NW TO SE
WITH ITS PASSAGE. LIKE LATE THIS AFTERNOON...THE COMBINATION OF
MEAGER CAPES AND A STRONG LOW LEVEL JET WARRANT A SLIGHT CHANCE OF
THUNDER...WITH A SEVERE STORM OR TWO NOT COMPLETELY OUT OF THE
QUESTION - BUT VERY UNLIKELY. USED A BLEND OF MAV/MET GUIDANCE
WITH NAM 2-METER TEMPERATURES FOR LOWS...WITH VALUES 5-10 DEGREES
ABOVE NORMAL.
PASSING 500 HPA TROUGH WARRANTS SLIGHT CHANCE POPS EARLY...BUT FOR
THE MOST PART EXPECT THURSDAY TO BE DRY WITH DECREASING LOUD COVER
AS HEIGHTS RISE IN THE WAVE OF THE SYSTEM LIFTING NE INTO THE
CANADIAN MARITIMES. FOR HIGHS USED A BLEND OF MIXING DOWN FROM 850
HPA WITH MAV/MET GUIDANCE AND NAM 2-METER TEMPERATURES.
FORECASTING VALUES TO BE A FEW DEGREES ABOVE NORMAL AS A
RESULT...AS COOLER TEMPERATURES IN THE LOW LEVELS DO NOT PUSH IN
UNTIL LATE IN THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
LATEST DATA BRINGS INCREASING CONFIDENCE IN A RAINY PERIOD FRI THROUGH
THE WEEKEND.
00Z MODELS SHOW THAT ACTIVE WEATHER WILL FOLLOW ROUGHLY IN THE VICINITY
OF THE 10C H85 ISOTHERM. THIS HAPPENS TO BE OVER OR NEAR THE CWA
THIS WEEKEND. BEFORE THAT HOWEVER...SOME UNCERTAINTY WITH RESPECT
TO PRECIPITATION CHANCES THU NIGHT AND FRI.
NAM AND ECMWF WERE THE FASTEST WITH THE PRECIPITATION DURING THAT
PERIOD. THIS IS THE TIMING FAVORED BY MODEL DIAGNOSTICS. THE GFS
KICKS IN AROUND 18Z FRI. TRENDED THE FCST TOWARDS THE FASTER
PROGS...WHICH TRANSLATES TO INCREASING CHANCES FOR LGT RAIN
THROUGH THE NIGHT.
CHANCES FOR RAIN FRI. MAINTAINED THE 40 POPS BECAUSE THE NAM SHOWED
MARGINAL PRECIPITATION AMOUNTS FOR MEASURABLE. IF THE MODEL CONSENSUS
CONTINUES HOWEVER...POPS WILL NEED TO BE RAISED SIGNIFICANTLY.
MID LEVEL MOISTURE CONVERGENCE ZONE REMAINS OVER THE CWA THIS
WEEKEND. IN ADDITION...H5 TROUGH WILL PRESENT THE OPPORTUNITY FOR
COASTAL CYCLOGENESIS. GFS AND ECMWF BOTH POINT TO THIS OCCURRING...
ALTHOUGH THE DETERMINISTIC SOLUTIONS ARE NOT EXACTLY ON THE SAME
SCHEDULE. OUTSIDE OF THIS LOW PRES DEVELOPMENT...PERIODS OF LGT
RAIN POSSIBLE DUE TO THE MOISTURE CONVERGENCE ALONE. POPS HAVE
THEREFORE BEEN INCREASED BY 10 PCT TO HIGH CHANCE.
IT LOOKED LIKE THE MODELS CLEARED THINGS OUT FOR MON...BUT THE 00Z
ECMWF ROLLED IN WET. FORCED TO MAINTAIN CHANCE SHRA FOR THIS PERIOD.
BEHAVIOR OF THE H5 CLOSED LOW IS THE MAIN DRIVER OF THE FCST. IT
SHOULD BE NOTED THAT THE 00Z ECMWF IS ABOUT 10DAM DEEPER THAN THE
GFS ENSEMBLE MEMBERS...BUT CLOSE TO THE CLUSTERING POSITION-WISE.
THE GFS IS DEEPER THAN THE ECMWF AND NE OF THE ENSEMBLE DATA...SO
APPEARS TO BE EVEN FURTHER AWAY FROM THE CONSENSUS. FCST IS
UNCERTAIN IN THIS TIME PERIOD.
IT DOES APPEAR SUPPRESSION OF HEIGHTS OVER THE CENTRAL CONUS TAKES
PLACE ON TUE...CHANGING THE UPPER LEVEL PATTERN. THEREFORE KEPT A DRY
FCST FOR TUE.
TEMPS THU NIGHT-FRI A BLEND OF THE BCGMOS/MET/MAV. THE REMAINDER OF
THE FCST A BLEND OF THE BCGMOS/MEN/ECE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
UPPER LEVEL DISTURBANCE IS CURRENTLY LIFTS N OF THE AREA EARLY
THIS MORNING. A COLD FRONT WILL MOVE THROUGH DURING THE EVENING
HOURS.
MAINLY VFR CONDS THROUGH THE PERIOD. CIGS/VSBY MAY BRIEFLY DROP
BETWEEN 2-3K FT AND 5SM RESPECTIVELY IN ANY SHOWERS...BUT HIGHEST
PROBABILITY IS AT KSWF AND MAINLY WITH THE FRONTAL PASSAGE THIS
EVENING. IF WINDS DECOUPLE TONIGHT AT KSWF...3-5SM VSBY IS
POSSIBLE. LOW CONFIDENCE AS DRIER AIR BEHIND THE FRONT WOULD BE
WORKING IN AT THE SAME TIME.
A MODERATE S/SW FLOW WILL CONTINUE THROUGH THE DAY. OCNL GUSTS UP TO
20 KT ARE POSSIBLE THROUGH THE REMAINDER OF THE NIGHT...MAINLY AT
COASTAL TERMINALS. SOME UNCERTAINTY WHEN GUSTS RETURN AND HOW
HIGH THEY WILL BE. MODELS ARE IN GOOD AGREEMENT THAT WINDS ALOFT
OVER WESTERN ZONES DECREASE THIS MORNING AND THEN INCREASE AGAIN
THIS AFTN. AT EASTERN TERMINALS...THEY COULD BE 1-2 HOURS EARLIER THAN
FORECAST...WHERE WINDS OFF THE DECK WILL BE HIGHER. GUSTS COULD
ALSO BE A FEW KT HIGHER BETWEEN 17Z AND 21Z AND MAY LINGER A FEW
HOURS LONGER THAN CURRENTLY FORECAST.
WDLY SCT SHOWERS EARLY...THEN PRECIP IS NOT EXPECTED TO RETURN
UNTIL UNTIL THE COLD FRONT APPROACHES LATE THIS AFTN/EARLY EVE. SCT
TO NUMEROUS SHOWERS AND POSSIBLY AN ISOLD RUMBLE OF THUNDER WILL
PRECEDE THE FROPA WHICH MOVES THROUGH THE TERMINALS BETWEEN 02Z TO
06Z THU RESULTING IN A WIND SHIFT TO THE W/NW AND DECREASING
SPEEDS. WEAK INSTABILITY AND STRONG WINDS ALOFT COULD PRODUCE
SOME GUSTY WINDS WITH THESE SHOWERS/TSTM. POSSIBLE GUSTS UP TO 30
KT.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE IN WINDS. GUSTS
AROUND 20 KT POSSIBLE BETWEEN 11Z AND 14Z.
KLGA FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE IN WINDS. GUSTS
AROUND 20 KT POSSIBLE BETWEEN 11Z AND 14Z.
KEWR FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE IN WINDS. GUSTS
AROUND 20 KT POSSIBLE BETWEEN 11Z AND 14Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED.
OUTLOOK FOR 06Z THURSDAY-SUNDAY...
.WED NIGHT-THU...VFR.
.FRI-SUN...MVFR OR LOWER POSSIBLE IN RAIN.
&&
.MARINE...
FORECAST APPEARS ON TRACKS...WITH MINOR ADJUSTMENT
MADE TO THE GRIDS FOR THIS MORNING TO REFLECT LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE.
GUSTS TO 25 KT EXPECTED ON ALL WATERS TODAY...THEN ON THE COASTAL
OCEAN AND EASTERN WATERS TONIGHT...WITH A 35 KT LOW LEVEL JET
CROSSING THE COASTAL OCEAN AND EASTERN WATERS. HAVE ISSUED A SMALL
CRAFT ADVISORY FOR ALL WATERS FOR TODAY...AND CONTINUED IT FOR THE
SOUTH SHORE BAYS THROUGH THIS EVENING...AND FOR THE COASTAL OCEAN
WATERS AND EASTERN SOUND/BAYS THROUGH TONIGHT.
SCA LEVEL SEAS SHOULD CONTINUE INTO THURSDAY...LINGERING LONGER
OVER THE EASTERN COASTAL OCEAN ZONES. CONFIDENCE THOUGH IS NOT
QUITE HIGH ENOUGH TO EXTEND THE SCA THERE AT THIS TIME. ON THE
REMAINDER OF THE WATERS SUB-SCA CONDITIONS ARE EXPECTED ON THURSDAY.
CONDITIONS WILL REMAIN BELOW SCA LEVELS THU NIGHT-SAT. NE FLOW WILL
INTENSIFY FOR THE SECOND HALF OF THE WEEKEND AS LOW PRES DEEPENS
NEAR THE WATERS. SCA CONDITIONS WILL BE POSSIBLE
SUNDAY...ESPECIALLY ON THE ERN OCEAN.
&&
.HYDROLOGY...
LESS THAN 1/4 INCH OF BASIN AVERAGE QPF IS EXPECTED THROUGH
TONIGHT...FOLLOWED BY DRY CONDITIONS THURSDAY.
WIDESPREAD SIGNIFICANT PRECIPITATION IS NOT EXPECTED THU NIGHT-TUE.
&&
.TIDES/COASTAL FLOODING...
FULL MOON ON SAT...SO SOME MINOR TIDAL FLOODING COULD BE POSSIBLE
WITH PERSISTENT E TO NE FLOW. MOST SUSCEPTIBLE SPOT WOULD BE THE S
SHORE BAYS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ335-
338.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ330-340-
350-353-355.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ345.
&&
$$
SYNOPSIS...MALOIT/JMC
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...JMC
AVIATION...24
MARINE...MALOIT/JMC
HYDROLOGY...MALOIT/JMC
TIDES/COASTAL FLOODING...JMC
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1024 AM EDT WED SEP 26 2012
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH FRIDAY. A COLD
FRONT IS EXPECTED TO APPROACH AND THEN LINGER NEAR THE AREA LATE
THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT WILL DOMINATE AGAIN
TODAY. THE LOW-LEVEL FLOW IS EXPECTED TO VEER MORE EASTERLY THIS
AFTERNOON IN RESPONSE TO SURFACE HIGH PRESSURE SHIFTING FARTHER
OUT INTO THE ATLANTIC. ALTHOUGH LOW-LEVEL MOISTURE WILL SLOWLY
INCREASE AS THE FLOW BECOMES MORE ONSHORE...26/13Z RAP SOUNDINGS
SUGGEST THE SUBCLOUD LAYER WILL REMAIN TOO DRY TO SUPPORT
MEASURABLE PRECIPITATION. STILL CAN NOT COMPLETELY RULE OUT A
SPRINKLE OR TWO ACROSS THE GEORGIA COASTAL COUNTIES...MAINLY ALONG
THE BEACHES FROM SAINT CATHERINES SOUND SOUTH TO THE ALTAMAHA
SOUND...BUT PROBABILITIES ARE TOO LOW TO JUSTIFY A MENTION AT THIS
TIME. EXPECT A MODEST CUMULUS FIELD TO DEVELOP AT THE COAST AND
SOUTH OF I-16 WITH MOSTLY SUNNY SKIES ELSEWHERE. HIGHS WILL RANGE
FROM THE MID 80S INLAND TO THE UPPER 70S/AROUND 80 AT THE BEACHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT...HIGH PRESSURE TO PERSIST TONIGHT WITH MAINLY CLEAR SKIES
IN PLACE. INCREASING LOW-LEVEL MOISTURE AND LIGHT WINDS WILL
PROMOTE FOG DEVELOPMENT...SOME OF WHICH COULD BECOME DENSE. LOWS
MAINLY IN THE LOWER TO MID 60S INLAND WITH LOWER 70S AT THE COAST.
THE FLOW ALOFT BECOMES MORE ZONAL THURSDAY THROUGH FRIDAY...AS THE
RIDGING TO THE SOUTH BEGINS TO WEAKEN AS SHORT WAVES PASS BY TO THE
NORTH. THIS PATTERN CAUSES SURFACE HIGH PRESSURE THAT IS INITIALLY
ATOP THE REGION EARLY THURSDAY TO WEAKEN...EVENTUALLY FORCING IT TO
WEAKEN ENOUGH FRIDAY WHERE THE CORE OF THE HIGH IS IN THE ATLANTIC
AND MERGING WITH HIGH PRESSURE MOVING OUT OF NEW ENGLAND. IN
RESPONSE THERE IS AN INCREASE IN SURFACE DEW POINTS AND COLUMNAR
MOISTURE AS A PERSISTENT EASTERLY SYNOPTIC FLOW SETS IN. ALTHOUGH
THERE IS SUFFICIENT INSTABILITY PRESENT WITH LIFTED INDICES NEAR
-3/-4 AND SBCAPES GREATER THAN 1000 J/KG...THERE IS LITTLE IN THE
WAY OF FORCING OUTSIDE OF THE SEA BREEZE. FOR THAT REASON WE WILL
SHOW NO MORE THAN 14 PERCENT POPS OVER LAND-BASED LOCATIONS. TEMPS
WILL MODERATE TO VALUES ABOVE SEASONAL NORMS...WITH AFTERNOON
MAXIMUM READINGS BOTH DAYS TO REACH THE MID-UPPER 80S MOST
LOCALES AWAY FROM THE SLIGHTLY COOLER COASTLINE. FOG WILL BE A
CONCERN THURSDAY MORNING AND AGAIN THURSDAY NIGHT INTO FRIDAY
MORNING WITH THE HIGHER DEW POINTS AND CONSIDERABLE DRY AIR IN THE
MID/UPPER LEVELS. WITH CONDENSATION PRESSURE DEFICITS LESS THAN 20
OR 30 MILLIBARS AND LIGHT WIND FIELDS IN THE PLANETARY BOUNDARY
LAYER WE WILL NEED TO MONITOR THE POTENTIAL FOR AT LEAST LOCALLY
DENSE FOG OCCURRING.
SATURDAY...THE RECENTLY FLAT FLOW ALOFT BECOMES MUCH MORE AMPLIFIED
AS A CLOSED LOW DEVELOPS OVER SE CANADA AND ITS ASSOCIATED SHORT
WAVE ENERGY DROPS SE THROUGH THE GREAT LAKES. THIS ESTABLISHES A
LARGE TROUGH OVER THE EASTERN STATES...WHILE AT THE SAME TIME
RIDGING FORMS OVER THE CENTRAL U.S. AND INTO SOUTH-CENTRAL CANADA. A
STRONG 100 KT OR GREATER JET PROGRESSES EASTWARD THROUGH THE BASE OF
THE EASTERN TROUGH AND PUSHES TOWARD THE MID ATLANTIC/SE STATES FOR
THE FIRST HALF OF THE WEEKEND. THIS IN TURN SENDS A COLD FRONT
TOWARD THE CENTRAL/SOUTHERN APPALACHIANS BY LATE IN THE DAY.
ADEQUATE MOISTURE/INSTABILITY...BETTER DYNAMIC FORCING ALOFT WITH
THE APPROACHING JET AND FALLING HEIGHTS SUPPORTS ISOLATED TO
SCATTERED SHOWERS/T-STORMS. COMPRESSIONAL HEATING IN ADVANCE OF THE
FRONT LOOKS TO BE ENOUGH TO OVERCOME AN INCREASE IN CLOUD COVER TO
BOOST TEMPS AS HIGH AS THE MID 80S AWAY FROM THE BEACHES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THE CLOSED LOW DROPS SOUTHWARD INTO THE OHIO VALLEY THE SECOND HALF
OF THE WEEKEND..WITH ITS ASSOCIATED LONG WAVE TROUGH TO DIG SOUTH TO
AT LEAST THE GULF COAST STATES...OR MAYBE EVEN INTO THE GULF OF
MEXICO. THIS IN TURN PUSHES THE COLD FRONT ACROSS THE APPALACHIANS
AS IT ATTEMPTS TO APPROACH THE FORECAST AREA SUNDAY. THE CLOSED LOW
THEN LIFTS OUT ON MONDAY...BUT IT LEAVES BEHIND A PIECE OF ENERGY
OVER THE LOWER MS VALLEY...WHICH THEN LOOKS TO CLOSE OFF BY MID
WEEK. UNCERTAINTY EXISTS IN THE FORECAST IN REGARDS TO THE
PROGRESSION OR LACK THEREOF FOR THE COLD FRONT. THE FRONT WILL
BECOME PARALLEL TO THE FLOW ALOFT...AND IT ALSO RUNS INTO A BUILDING
ATLANTIC SUB-TROPICAL RIDGE ALOFT. PLUS A SURFACE WAVE MAY FORM ON
THE FRONT IN THE GULF OF MEXICO...WHICH WOULD FURTHER SLOW THE
PROGRESSION OF THE FRONT. WE/LL KEEP THE FRONT IN CLOSE PROXIMITY TO
OUR AREA DURING THE EARLY AND MIDDLE PART OF NEXT WEEK...AND THUS A
GREATER CHANCE OF PRECIPITATION. WE PREFER TO KEEP THE RAIN CHANCE
NO HIGHER THAN 30-40 PERCENT...BUT THAT COULD CHANGE SIGNIFICANTLY
ONE WAY OR THE OTHER DEPENDING UPON THE FUTURE PROGRESSION OF THE
FRONT AND THE PATTERN ALOFT. TEMPS WILL HOLD NEAR OR SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
KSAV...SCATTERED TO BROKEN STRATOCUMULUS CLOUDS WILL IMPACT THE
TERMINAL THIS MORNING...TRANSITIONING OVER TO CUMULUS CLOUDS THIS
AFTERNOON. CONDITIONS WILL TEETER NEAR MARGINAL MVFR CEILINGS AS A
RESULT...BUT FOR NOW WE HAVE MAINTAINED THE VFR WEATHER. THE SET
UP LOOKS AT LEAST MODERATELY FAVORABLE FOR LATE NIGHT FOG AND
STRATUS...PRODUCING MVFR OR MAYBE EVEN IFR CONDITIONS AFTER 08Z.
KCHS...VFR WEATHER WILL PREVAIL TODAY THROUGH MOST OF
TONIGHT...WITH THE POTENTIAL FOR MVFR CONDITIONS LATE TONIGHT IN
FOG/STRATUS. PROBABILITIES AT THIS TIME DO NOT JUSTIFY ANYTHING
WORSE THAN 6SM IN MIST AND FEW STRATUS CLOUDS AT 800 FEET.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CONDITIONS POSSIBLE IN
FOG THURSDAY MORNING AND AGAIN LATE THURSDAY NIGHT/FRIDAY MORNING.
ISOLATED TO SCATTERED SHRA/TSRA SATURDAY INTO SUNDAY MAY
TEMPORARILY REDUCE VSBYS/CIGS TO SUB-VFR LEVELS.
&&
.MARINE...
TODAY AND TONIGHT...HIGH PRESSURE WILL PERSIST OVER OR JUST NORTH
OF THE AREA KEEPING A LIGHT-MODERATE NORTHEAST/EAST FLOW ACROSS
THE LOCAL WATERS. SEAS WILL BE ON A DOWNWARD TREND...WITH
SIGNIFICANT WAVE HEIGHTS PEAKING AT 5 FT THIS MORNING ACROSS THE
EASTERN EDGES OF THE OFFSHORE GEORGIA WATERS...OTHERWISE NO HIGHER
THAN 3 OR 4 FT ELSEWHERE TO OCCUR.
THURSDAY THROUGH SUNDAY...WEAK HIGH PRESSURE WILL PREVAIL ACROSS THE
WATERS INTO SATURDAY...WHICH GIVES WAY TO A COLD FRONT SUNDAY. WIND
AND SEA CONDITIONS ACROSS THE MARINE AREA DURING THIS TIME WILL
REMAIN RELATIVELY QUIET...WITH MOSTLY GENTLE OR MODERATE BREEZES
/WMO CLASSIFICATION/...AND SEAS 3 FEET OR LESS. MARINERS WILL
EXPERIENCE A FEW SHOWERS OR T-STORMS THROUGH THE WEEKEND...WITH THE
HIGHEST PROBABILITIES TO OCCUR LATE SUNDAY IN ADVANCE OF THE COLD
FRONT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...RJB
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
954 AM CDT WED SEP 26 2012
...UPDATED FOR CURRENT TRENDS...
.SYNOPSIS...
ISSUED AT 1214 AM CDT WED SEP 26 2012
AT 00Z WEDNESDAY A 500MB LOW WAS LOCATED JUST NORTH OF THE FOUR
CORNERS REGION WITH A 250MB 55KT JET STREAK LOCATED ON ITS WEST
SIDE DIVING SOUTH ACROSS WESTERN NEVADA. ANOTHER 50KT JET WAS
LOCATED IN THE BASED ON THIS UPPER LOW/TROUGH OVER NORTHERN
NEVADA. FURTHER EAST ACROSS SOUTHWEST KANSAS THE WATER VAPOR LOOP
AND RAP 400MB POTENTIAL VORTICITY INDICATED AN UPPER LEVEL TROUGH
MOVING EAST FROM SOUTHEAST COLORADO INTO SOUTHWEST KANSAS. CLOUD
TOPS WERE COOLING AHEAD OF THIS FEATURE FROM 00Z- 02Z. A 700MB
BAROCLINIC ZONE WAS ALSO LOCATED IN THIS AREA AT 00Z AND AT THE
850MB LEVEL WARM AIR ADVECTION WAS LOCATED ALONG AND NORTH OF A
SURFACE BOUNDARY WHICH WAS LOCATED FROM THE PANHANDLE OF OKLAHOMA
ACROSS SOUTH CENTRAL KANSAS.
&&
.UPDATE...
ISSUED AT 953 AM CDT WED SEP 26 2012
A CLUSTER OF ELEVATED THUNDERSTORMS THAT ORIGINATED NEAR THE 310K
THETA LEVEL IN WEAK WESTERLY ISENTROPIC LIFT NEAR THE COLORADO LINE
THIS MORNING, HAS DECAYED ALONG AND EAST OF THE HIGHWAY 83 CORRIDOR.
THERE DOES NOT APPEAR TO BE AN IMMEDIATE MECHANISM TO DEVELOP
ADDITIONAL CONVECTION, AND PROBABILITIES HAVE BEEN REDUCED
SIGNIFICANTLY FROM NOW UNTIL THE AFTERNOON WHEN INSTABILITY INCREASES.
A MID LEVEL CLOUD FIELD ASSOCIATED WITH CONVECTIVE OUTFLOW AND A MID
LEVEL BAROCLINIC ZONE IS HAVING A LARGE EFFECT ON RAP MODEL MAX
TEMPERATURES ACROSS CENTRAL KANSAS. TEMPERATURE WILL LIKELY NOT
EXCEED 70 DEGREES THIS AFTERNOON IN A COOL CLOUDY REGIME THROUGH
THE INTERSTATE 70 CORRIDOR.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 147 AM CDT WED SEP 26 2012
SATELLITE LOOP INDICATING SKIES ATTEMPTING TO CLEAR BEHIND THE
FIRST UPPER LEVEL TROUGH THAT WAS CROSSING SOUTHWEST KANSAS
EARLIER THIS MORNING. THIS FIRST WAVE WAS REFLECTED WELL BY THE
WATER VAPOR LOOP AND RAP 400MB POTENTIAL VORTICITY. AS THIS SYSTEM
EXITS WESTERN KANSAS THE PRECIPITATION CHANCES WILL DROP WITH THE
POSSIBLE EXCEPTION OF NORTH CENTRAL KANSAS AS ANOTHER WEAKER WAVE
CROSSES SOUTHWEST KANSAS EARLY WEDNESDAY MORNING. WILL MONITOR
TREND AND INSERT A PERIOD OF EARLY MORNING CLOUDS AND POSSIBLE
LIGHT RAINSHOWERS/SPRINKLES AS NEEDED.
THE NEXT DECENT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE
TODAY AND ESPECIALLY OVERNIGHT AS THE UPPER LEVEL JET THAT WAS
LOCATED OVER NEVADA ROTATES AROUND THE 500MB LOW AND APPROACHES
THE AREA. NAM AND GFS WERE IN DECENT AGREEMENT WITH THE PLACEMENT
OF THIS UPPER LEVEL FEATURE LATE TODAY WITH IMPROVING 850-700MB MOISTURE
AND FRONTOGENESIS DEVELOPING NORTH OF THE COLD FRONT. 00Z NAM AND
00Z GFS DO HOWEVER DIFFER SLIGHTLY ON THE LOCATION ON WHERE THE
BETTER FRONTOGENESIS BUT THE GENERAL TREND IS CONVECTION CHANCES
IMPROVING FROM WEST TO EAST LATE TODAY ACROSS WESTERN KANSAS.
AROUND 40 KNOTS OF 0-6KM SHEAR ARE EXPECTED BY LATE DAY BASED ON
THE 00Z NAM. CAPE VALUES WILL ACROSS WESTERN KANSAS ARE EXPECTED
TO BE AROUND 1000J/KG WITH 0-2.5KM LAPSE RATES EXCEEDING 8C/KM.
GIVEN THIS AND SOME LATE DAY FORCING DEVELOPING WILL KEEP A
MENTION OF SEVERE STORMS GOING IN THE HAZARDOUS WEATHER OUTLOOK.
MAIN HAZARD APPEARS TO BE HAIL.
AS FOR TEMPERATURES...THE OVERNIGHT RAINFALL AND EXPECTED CLOUD
COVER LATER TODAY SHOULD LIMIT THE WARM UP THIS AFTERNOON. AT THIS
TIME WILL TREND TOWARDS THE COOLER GUIDANCE WHICH SUPPORTS THE
850MB MIX DOWN TEMPERATURES FROM THE NAM AND GFS ALONG WITH WHAT
THE PREVIOUS SHIFT SUGGESTED. WILL ALSO NOT DEVIATE FAR FROM THE
LOWS TONIGHT GIVEN THE MID 50S TO NEAR 60 DEWPOINTS FORECAST NORTH
OF THE FRONT ACROSS SOUTHWEST KANSAS AND EXPECTED CLOUD COVER.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED SEP 26 2012
THE NEXT SHORTWAVE TROUGH WILL APPROACH WESTERN KANSAS THURSDAY.
WITH ABUNDANT LOW LEVEL MOISTURE IN PLACE, THERE IS A GOOD CHANCE
FOR SHOWERS AND THUNDERSTORMS. PRECIPITATION WILL AIDED BY LIFT
IN THE LEFT EXIT REGION OF A 90 KT JET STREAK WITH ASSOCIATED MID-
LEVEL BAROCLINIC ZONE AND ISENTROPIC LIFT. THE POTENTIAL FOR
SEVERE WEATHER MAY BE LOW BECAUSE OF WIDESPREAD CLOUD COVER AND
COOL SURFACE TEMPERATURES. HOWEVER, A FEW ELEVATED SEVERE STORMS
WITH LARGE HAIL CANNOT BE RULED OUT GIVEN THE APPROACH OF THE
100KT UPPER-LEVEL JET, PLENTIFUL MOISTURE AND FAIRLY COOL
TEMPERATURES AT 500MB.
STORM CHANCES DECREASE AFTER THURSDAY WHEN THIS SYSTEM PASSES.
HOWEVER, GENERAL UPPER-LEVEL TROUGHINESS WILL REMAIN, AND WITH
RESIDUAL LOW LEVEL MOISTURE AND FAIRLY COOL 500MB TEMPERATURES
PERSISTING, SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
CONTINUE INTO FRIDAY AND SATURDAY. HIGH TEMPERATURES WILL STAY
RATHER COOL GIVEN THE CLOUD COVER AND FAIRLY COOL AIRMASS STILL IN
PLACE. LOW TEMPERATURES ARE EXPECTED TO SLOWLY FALL AS DEWPOINTS
GRADUALLY DECREASE.
DRY WEATHER AND A WARMING TREND WILL COMMENCE BY SATURDAY AND
CONTINUE THROUGH MID NEXT WEEK AS UPPER-LEVEL RIDGING BUILDS OVER THE
ROCKIES AND WESTERN HIGH PLAINS. HIGH TEMPERATURES OUGHT TO WARM
INTO THE UPPER 70S BY SUNDAY AND 80S BY MONDAY AND TUESDAY. EVEN
WARMER HIGH TEMPERATURES IN THE UPPER 80S TO LOWER 90S ARE POSSIBLE
BY MID NEXT WEEK AS UPPER-LEVEL TROUGHING BEGINS TO DEVELOP ALONG
THE WEST COAST, WITH LEE TROUGHING AND WEAK DOWNSLOPE LOW-LEVEL
FLOW ON THE HIGH PLAINS. AFTER COORDINATION WITH SURROUNDING OFFICES,
IT WAS DECIDED TO RAISE MAXIMUM TEMPERATURES ABOVE THOSE GIVEN BY THE
CENTRAL REGION INITIALIZATION GRIDS. THESE TEMPERATURES MAY STILL
BE TOO COOL. LOWS SHOULD BE MAINLY IN THE 50S THROUGH NEXT WEEK,
WITH SOME 40S POSSIBLE IN THE TRADITIONALLY COOLER AREAS NEAR THE
COLORADO BORDER ON THE HIGHER TERRAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 654 AM CDT WED SEP 26 2012
NORTHEAST TO EASTERLY UPSLOPE FLOW WILL PERSIST THROUGH THE TAF
PERIOD TO THE NORTH OF A STATIONARY FRONT. THERE IS A CHANCE FOR
THUNDERSTORMS IN VICINITY OF THE TAF SITES, ESPECIALLY AFTER 23Z
AND THROUGH THE END OF THE TAF PERIOD. OUTSIDE OF THUNDERSTORMS
VFR CONDITIONS WILL PERSIST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 79 58 76 61 / 30 60 60 50
GCK 79 56 75 59 / 30 50 50 40
EHA 81 55 76 58 / 40 50 40 30
LBL 82 57 77 60 / 30 50 60 40
HYS 67 56 74 59 / 30 40 40 40
P28 79 62 78 62 / 20 50 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RUSSELL
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
700 AM CDT WED SEP 26 2012
...UPDATED FOR AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1214 AM CDT WED SEP 26 2012
AT 00Z WEDNESDAY A 500MB LOW WAS LOCATED JUST NORTH OF THE FOUR
CORNERS REGION WITH A 250MB 55KT JET STREAK LOCATED ON ITS WEST
SIDE DIVING SOUTH ACROSS WESTERN NEVADA. ANOTHER 50KT JET WAS
LOCATED IN THE BASED ON THIS UPPER LOW/TROUGH OVER NORTHERN
NEVADA. FURTHER EAST ACROSS SOUTHWEST KANSAS THE WATER VAPOR LOOP
AND RAP 400MB POTENTIAL VORTICITY INDICATED AN UPPER LEVEL TROUGH
MOVING EAST FROM SOUTHEAST COLORADO INTO SOUTHWEST KANSAS. CLOUD
TOPS WERE COOLING AHEAD OF THIS FEATURE FROM 00Z- 02Z. A 700MB
BAROCLINIC ZONE WAS ALSO LOCATED IN THIS AREA AT 00Z AND AT THE
850MB LEVEL WARM AIR ADVECTION WAS LOCATED ALONG AND NORTH OF A
SURFACE BOUNDARY WHICH WAS LOCATED FROM THE PANHANDLE OF OKLAHOMA
ACROSS SOUTH CENTRAL KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 147 AM CDT WED SEP 26 2012
SATELLITE LOOP INDICATING SKIES ATTEMPTING TO CLEAR BEHIND THE
FIRST UPPER LEVEL TROUGH THAT WAS CROSSING SOUTHWEST KANSAS
EARLIER THIS MORNING. THIS FIRST WAVE WAS REFLECTED WELL BY THE
WATER VAPOR LOOP AND RAP 400MB POTENTIAL VORTICITY. AS THIS SYSTEM
EXITS WESTERN KANSAS THE PRECIPITATION CHANCES WILL DROP WITH THE
POSSIBLE EXCEPTION OF NORTH CENTRAL KANSAS AS ANOTHER WEAKER WAVE
CROSSES SOUTHWEST KANSAS EARLY WEDNESDAY MORNING. WILL MONITOR
TREND AND INSERT A PERIOD OF EARLY MORNING CLOUDS AND POSSIBLE
LIGHT RAINSHOWERS/SPRINKLES AS NEEDED.
THE NEXT DECENT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE
TODAY AND ESPECIALLY OVERNIGHT AS THE UPPER LEVEL JET THAT WAS
LOCATED OVER NEVADA ROTATES AROUND THE 500MB LOW AND APPROACHES
THE AREA. NAM AND GFS WERE IN DECENT AGREEMENT WITH THE PLACEMENT
OF THIS UPPER LEVEL FEATURE LATE TODAY WITH IMPROVING 850-700MB MOISTURE
AND FRONTOGENESIS DEVELOPING NORTH OF THE COLD FRONT. 00Z NAM AND
00Z GFS DO HOWEVER DIFFER SLIGHTLY ON THE LOCATION ON WHERE THE
BETTER FRONTOGENESIS BUT THE GENERAL TREND IS CONVECTION CHANCES
IMPROVING FROM WEST TO EAST LATE TODAY ACROSS WESTERN KANSAS.
AROUND 40 KNOTS OF 0-6KM SHEAR ARE EXPECTED BY LATE DAY BASED ON
THE 00Z NAM. CAPE VALUES WILL ACROSS WESTERN KANSAS ARE EXPECTED
TO BE AROUND 1000J/KG WITH 0-2.5KM LAPSE RATES EXCEEDING 8C/KM.
GIVEN THIS AND SOME LATE DAY FORCING DEVELOPING WILL KEEP A
MENTION OF SEVERE STORMS GOING IN THE HAZARDOUS WEATHER OUTLOOK.
MAIN HAZARD APPEARS TO BE HAIL.
AS FOR TEMPERATURES...THE OVERNIGHT RAINFALL AND EXPECTED CLOUD
COVER LATER TODAY SHOULD LIMIT THE WARM UP THIS AFTERNOON. AT THIS
TIME WILL TREND TOWARDS THE COOLER GUIDANCE WHICH SUPPORTS THE
850MB MIX DOWN TEMPERATURES FROM THE NAM AND GFS ALONG WITH WHAT
THE PREVIOUS SHIFT SUGGESTED. WILL ALSO NOT DEVIATE FAR FROM THE
LOWS TONIGHT GIVEN THE MID 50S TO NEAR 60 DEWPOINTS FORECAST NORTH
OF THE FRONT ACROSS SOUTHWEST KANSAS AND EXPECTED CLOUD COVER.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED SEP 26 2012
THE NEXT SHORTWAVE TROUGH WILL APPROACH WESTERN KANSAS THURSDAY.
WITH ABUNDANT LOW LEVEL MOISTURE IN PLACE, THERE IS A GOOD CHANCE
FOR SHOWERS AND THUNDERSTORMS. PRECIPITATION WILL AIDED BY LIFT
IN THE LEFT EXIT REGION OF A 90 KT JET STREAK WITH ASSOCIATED MID-
LEVEL BAROCLINIC ZONE AND ISENTROPIC LIFT. THE POTENTIAL FOR
SEVERE WEATHER MAY BE LOW BECAUSE OF WIDESPREAD CLOUD COVER AND
COOL SURFACE TEMPERATURES. HOWEVER, A FEW ELEVATED SEVERE STORMS
WITH LARGE HAIL CANNOT BE RULED OUT GIVEN THE APPROACH OF THE
100KT UPPER-LEVEL JET, PLENTIFUL MOISTURE AND FAIRLY COOL
TEMPERATURES AT 500MB.
STORM CHANCES DECREASE AFTER THURSDAY WHEN THIS SYSTEM PASSES.
HOWEVER, GENERAL UPPER-LEVEL TROUGHINESS WILL REMAIN, AND WITH
RESIDUAL LOW LEVEL MOISTURE AND FAIRLY COOL 500MB TEMPERATURES
PERSISTING, SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
CONTINUE INTO FRIDAY AND SATURDAY. HIGH TEMPERATURES WILL STAY
RATHER COOL GIVEN THE CLOUD COVER AND FAIRLY COOL AIRMASS STILL IN
PLACE. LOW TEMPERATURES ARE EXPECTED TO SLOWLY FALL AS DEWPOINTS
GRADUALLY DECREASE.
DRY WEATHER AND A WARMING TREND WILL COMMENCE BY SATURDAY AND
CONTINUE THROUGH MID NEXT WEEK AS UPPER-LEVEL RIDGING BUILDS OVER THE
ROCKIES AND WESTERN HIGH PLAINS. HIGH TEMPERATURES OUGHT TO WARM
INTO THE UPPER 70S BY SUNDAY AND 80S BY MONDAY AND TUESDAY. EVEN
WARMER HIGH TEMPERATURES IN THE UPPER 80S TO LOWER 90S ARE POSSIBLE
BY MID NEXT WEEK AS UPPER-LEVEL TROUGHING BEGINS TO DEVELOP ALONG
THE WEST COAST, WITH LEE TROUGHING AND WEAK DOWNSLOPE LOW-LEVEL
FLOW ON THE HIGH PLAINS. AFTER COORDINATION WITH SURROUNDING OFFICES,
IT WAS DECIDED TO RAISE MAXIMUM TEMPERATURES ABOVE THOSE GIVEN BY THE
CENTRAL REGION INITIALIZATION GRIDS. THESE TEMPERATURES MAY STILL
BE TOO COOL. LOWS SHOULD BE MAINLY IN THE 50S THROUGH NEXT WEEK,
WITH SOME 40S POSSIBLE IN THE TRADITIONALLY COOLER AREAS NEAR THE
COLORADO BORDER ON THE HIGHER TERRAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 654 AM CDT WED SEP 26 2012
NORTHEAST TO EASTERLY UPSLOPE FLOW WILL PERSIST THROUGH THE TAF
PERIOD TO THE NORTH OF A STATIONARY FRONT. THERE IS A CHANCE FOR
THUNDERSTORMS IN VICINITY OF THE TAF SITES, ESPECIALLY AFTER 23Z
AND THROUGH THE END OF THE TAF PERIOD. OUTSIDE OF THUNDERSTORMS
VFR CONDITIONS WILL PERSIST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 81 58 76 61 / 30 60 60 50
GCK 79 56 75 59 / 40 50 50 40
EHA 83 55 76 58 / 40 50 40 30
LBL 85 57 77 60 / 30 50 60 40
HYS 78 56 74 59 / 30 40 40 40
P28 83 62 78 62 / 30 50 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1031 AM EDT WED SEP 26 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE SOUTHERN MID-ATLANTIC COAST AND
SOUTHEAST STATES TODAY AS A COLD FRONT APPROACHES FROM THE GREAT
LAKES. THIS COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT...AND
STALL OUT JUST SOUTH OF THE AREA THROUGH THE REST OF THE WEEK AND
INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT CURRENTLY ACROSS THE CENTRAL GREAT LAKES MOVING INTO
THE NORTHERN OHIO VALLEY. BOUNDARY IS DE-MARKED ON THE REGIONAL
RADAR LOOPS AS A LINE OF SHOWERS ACROSS NORTHERN OH AND NW PA.
WARM ADVECTION SHOWERS ARE ARE NOTED OVER WV AND THE FAR WEST CWFA.
MODIFIED 12Z SOUNDING SHOWED AN INVERTED V STRUCTURE...WITH AROUND
1500 J/KG OF SURFACE BASED CAPE. EARLIER CLOUDS THINNED OUT A BIT
THIS MORNING BEHIND A SHORTWAVE...AND HAVE ALLOWED TEMPS TO RISE
INTO THE MIDDLE 60S TO AROUND 70 THIS MORNING. MAX TEMPS SHOULD BE
IN THE UPPER 70S TO LOWER 80S ACROSS MOST LOCALES. DO EXPECT
CLOUDS TO FILL BACK IN THIS AFTERNOON...WHICH SHOULD HELP LIMIT
WIDESPREAD THUNDERSTORM ACTIVITY. HOWEVER...STEEP LAPSE RATES...A
30 TO 40 KT LLJ AND A MID LEVEL SHORTWAVE WILL ALL COMBINE TO HELP
SCATTERED THUNDERSTORM FORMATION WITH ISOLATED SEVERE STORMS.
LATEST RUNS OF HRRR SHOWS A LINE OF SHOWERS AND ISOLATED
THUNDERSTORMS IMPACTING AREAS EAST OF THE BLUE RIDGE AFTER 2 PM.
COLD FRONT LOCATED OVER THE GREAT LAKES SLOWLY SAGS TO THE
SOUTH...MOVING THROUGH THE CWA TONIGHT. FRONTAL BOUNDARY AND
EMBEDDED VORT MAXES WITHIN WESTERLY FLOW WILL KEEP A CHANCE OF
SHOWERS THROUGH THE NIGHT. HIGHEST CONCENTRATION MAY FOCUS NEAR
THE FRONTAL BOUNDARY AS IT PROGRESSES THROUGH NORTHERN VIRGINIA
LATE TONIGHT...SO POPS WILL INCREASE SOME WITH SOUTHERN EXTENT
OVERNIGHT.
&&
.SHORT TERM /THURSDAY/...
FRONTAL BOUNDARY IS FORECAST TO STALL ACROSS CENTRAL VIRGINIA ON
THURSDAY...AS A WEAK WAVE OF LOW PRESSURE DEVELOPS ALONG IT. FRONTAL
BOUNDARY AND MID-LEVEL VORT MAXES WILL MEAN A CONTINUATION OF AT
LEAST SCATTERED SHOWERS...BUT GIVEN THE POSITION OF THE FRONTAL
BOUNDARY THE POP DISTRIBUTION MAY REVERSE ON THURSDAY WHERE THE
HIGHEST POPS WILL BE ACROSS THE SOUTHERN PORTION OF THE CWA AND
LOWER POPS ACROSS THE NORTH. ACROSS THE SOUTHERN PORTION OF THE
CWA...THERE MAY ALSO BE ISOLATED THUNDERSTORMS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A COLD FRONT WILL LINGER ACROSS SOUTHERN PARTS OF THE REGION
THURSDAY NIGHT THROUGH THE WEEKEND. UPPER LEVEL DISTURBANCES WILL
MOVE WEST TO EAST ALONG THE FRONT CREATING SHOWERS AND A FEW
THUNDERSTORMS ACROSS THE REGION PERIODICALLY. PRECIPITATION
AMOUNTS...GENERALLY...SHOULD AVERAGE ONE QUARTER TO ONE HALF OF AN
INCH WITH ISOLATED HIGHER AMOUNTS...ESPECIALLY IN ANY
THUNDERSTORMS. THE BEST CHANCE FOR THUNDERSTORMS BETWEEN THURSDAY
NIGHT AND SATURDAY APPEARS TO BE LATE FRIDAY INTO FRIDAY EVENING
AS AN AREA OF LOW PRESSURE TRIES TO FORM ALONG THE STALLED FRONT
ABOUT THE SAME TIME THAT A SIGNIFICANT UPPER LEVEL TROUGH OF LOW
PRESSURE DROPS SOUTHWARD OUT OF THE EASTERN GREAT LAKES BEFORE
SWINGING EASTWARD. LIFTED INDICES RANGE FROM -2 TO -4 FRIDAY
AFTERNOON. TEMPERATURES ARE EXPECTED TO BE NEAR TO SLIGHTLY BELOW
NORMAL. OVERNIGHT FRIDAY INTO SATURDAY...THE BULK OF THE SHOWER
AND THUNDERSTORM ACTIVITY SHOULD SHIFT TO THE CHESAPEAKE BAY AS
THE UPPER LEVEL TROUGH PIVOTS TO BECOME PARALLEL TO THE
APPALACHIAN MOUNTAINS. WINDS MAY INCREASE SOME FROM THE NORTH AS
THE SURFACE LOW PUSHES OUT TO SEA.
THE SIGNIFICANT UPPER LEVEL TROUGH OF LOW PRESSURE WILL TRY TO WORK
ITS WAY INTO PARTS OF NEW ENGLAND AND ALONG THE EASTERN SEABOARD. IT
IS A LITTLE TOO EARLY TO TELL HOW STRONG THE UPPER LEVEL TROUGH WILL
BE BY LATE SUNDAY INTO MONDAY. THE INTERACTION BETWEEN THE UPPER
LEVEL TROUGH AND THE BUILDING HIGH TO THE WEST COULD INDUCE STRONGER
WINDS AT THE SURFACE. FOR NOW...WE WONT PLAY THOSE WINDS UP TOO MUCH
FOR THE POSSIBILITY OF MODELS FLIP-FLOPPING ON THE STRENGTH AND
POSITION OF THE TROUGH.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
SHORTWAVE OVER THE OHIO VALLEY WILL CONTINUE TO MOVE EAST TODAY
AND IMPACT THE CWFA THIS AFTERNOON. THE MID LEVEL ENERGY IN
COMBINATION WITH AN APPROACHING FRONT WILL LEAD TO THE DEVELOPMENT
OF SCT/NMRS SHOWERS AND ISO/SCT THUNDERSTORMS DURING THE
AFTERNOON. PRECIP COVERAGE SHOULD BE HIGHEST ALONG THE MASON DIXON
LINE. CONFIDENCE IN EXACTLY WHERE THUNDERSTORMS WOULD DEVELOP/MOVE
WAS LOW...SO NOT MENTIONED IN THE TAFS AT THIS TIME. COLD FRONT SAGS
SOUTH THROUGH THE AREA TONIGHT.
PERIODIC SHOWERS ARE EXPECTED ACROSS THE TERMINALS LATE IN THE
WEEK AND INTO THE WEEKEND AS A SLOW MOVING COLD FRONT SAGS INTO
AND STALLS OVER THE REGION. THERE IS THE POTENTIAL FOR MVFR OR
EVEN IFR CIGS DEVELOPING LATE THURSDAY NIGHT INTO FRIDAY MORNING
NORTH OF THE FRONT WITH A NORTHEAST WIND DEVELOPING.
&&
.MARINE...
SIMILAR TO LAST NIGHT...SOUTH/SOUTHWEST WINDS WERE EFFICIENTLY
CHANNELLING UP THE BAY FOR AROUND 20 KT WINDS. THESE WINDS REMAIN
IN PLACE THROUGH THE DAY...AS DOES THE SCA. COLD FRONT SLIPS SOUTH
THROUGH THE WATERS TONIGHT. WIND SHIFT/LESS WIND WILL PRECLUDE THE
NEED FOR A SCA ON THURSDAY.
A NORTHEAST WIND WILL EVENTUALLY EVOLVE WITH THE FRONT SAGGING JUST
TO THE SOUTH THROUGH THE END OF THE WEEK. THESE WINDS MAY
INCREASE LATER IN THE WEEKEND INTO EARLY NEXT WEEK DEPENDING ON
THE TIMING AND LOCATION OF A DEVELOPING LOW PRESSURE SYSTEM.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ530>534-
537>543.
&&
$$
UPDATE...LISTEMAA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
749 AM EDT WED SEP 26 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EDT WED SEP 26 2012
WV IMAGERY AND RUC ANALYSIS SHOWING UPPER TROUGH STRETCHING SW OVER
THE UPPER GREAT LKS FROM NRN QUEBEC. SHORTWAVE CURRENTLY ROTATING
THROUGH THE AXIS OF THE TROUGH OVER WRN LK SUPERIOR. AREA OF CLOUDS
ASSOCIATED WITH THIS SHORTWAVE HAVE BEEN STRUGGLING TO MOVE ACROSS
WRN LK SUPERIOR...BUT ARE FINALLY STARTING TO MOVE OVER LAND.
FARTHER EAST...A FEW AREAS OF LK ENHANCED RAIN SHOWERS HAVE BEEN
ONGOING OVER THE MAINLY NW FLOW ACROSS EASTERN LK SUPERIOR. THESE
HAVE BEEN DRIFTING MORE TO THE S OVER TIME AS 8Z KMQT VAD WIND
PROFILE SHOWING MORE NNW WINDS ALOFT. THESE SHOWERS LINE UP WELL
WITH MODEL INDICATED POCKET OF DEEPEST MOISTURE.
THE SHOWERS AND CLOUDS ASSOCIATED WITH THE SHORTWAVE WILL BE THE
MAIN CONCERNS FOR THE SHORT TERM PERIOD. EXPECT THE SHOWERS TO
CONTINUE TO SLIDE TO THE SSE UNDER THE NNW FLOW ALOFT THROUGH THE
MORNING HOURS AND LARGELY BE FOCUSED OVER NCNTRL UPPER MI. WITH THE
SHORTWAVE BRUSHING THE NE HALF OF THE CWA...COULD SEE AN INCREASE IN
INTENSITY FOR A WHILE THIS EARLY MORNING...BEFORE THE SHORTWAVE
QUICKLY DIVES SE OF THE CWA. AS THIS OCCURS...EXPECT THE MOISTURE TO
EXIT AND BRING AN END TO THE SHOWERS AS H500 HEIGHTS ARE ON THE
RISE. AS FOR CLOUDS...THERE SHOULD BE ENOUGH LLVL MOISTURE TO
PRODUCE A MOSTLY CLOUDY SKY NEAR LK SUPERIOR THIS MORNING AND THEN
SPREAD ACROSS MUCH OF THE REST OF THE CWA UNDER DIURNAL HEATING BY
MID DAY. THEN THE PREVIOUSLY MENTIONED DRYING WILL BEGIN TO TAKE
HOLD IN THE AFTN AND DIMINISH THE CLOUDS FROM NW TO SE ACROSS THE
CWA...WITH THE CLOUDS HOLDING ON THE LONGEST OVER ERN UPPER MI
/TOWARDS EARLY EVENING/. H850 TEMPS A DEGREE OR TWO COOLER TODAY
THAN YESTERDAY...SO EXPECT A SLIGHTLY COOLER DAY AND HIGHS IN THE
50S.
AS HAS BEEN DISCUSED OVER THE LAST SEVERAL SHIFTS...APPEARS TO BE A
GOOD FROST/FREEZE OVER MUCH OF UPPER MI TONIGHT. HIGH PRESSURE
CURRENTLY OVER SRN MANITOBA WILL SLIDE OVERHEAD AND PRODUCE CLEAR
SKIES OVER ALL BUT FAR EASTERN UPPER MI /LINGERING LK EFFECT
CLOUDS/. PWATS AROUND 50 PERCENT OF NORMAL AND CLEAR SKIES WILL
PROMOTE RADIATIONAL COOLING AND EXPECT LOWS IN THE MID 20S TO LOWER
30S OVER MOST INTERIOR LOCATIONS. UNDER SIMILAR CONDITIONS THIS
MORNING...MANY LOCATIONS IN THE INTERIOR WEST FELL INTO THE UPPER
20S. THEREFORE...EXPECT ANOTHER DECENT FROST/FREEZE ACROSS THE
AREA...WHICH COULD EVEN EFFECT AREAS CLOSE TO THE GREAT LKS
SHORELINES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 450 AM EDT WED SEP 26 2012
TEHRE IS A FAIR AMOUNT OF DISAGREEMENT IN MEDIUM RANGE GUIDANCE FOR
THE NEXT 7 DAYS. CURRENT TROF OVER ERN CANADA INTO THE GREAT LAKES
WILL LIFT OUT OVER THE NEXT FEW DAYS. HOWEVER...ANOTHER SHORTWAVE
WILL BE DROPPING SE AS THE TROF LIFTS OUT LATE WEEK. MODELS HAVE
BEEN STRUGGLING WITH EXACTLY WHAT HAPPENS WITH THAT PIECE OF ENERGY.
MORE ON THAT LATER. FORTUNATELY...THE ARRAY OF SOLUTIONS DOESN`T
IMPACT THE PCPN FCST. THE DIFFERENCES IN GUIDANCE INTO/THRU THE
WEEKEND TRANSITION TO LARGER DIFFERENCES DURING THE EARLY PART OF
NEXT WEEK AS GFS/ECMWF HAVE BEEN VARYING BTWN NW AND WSW FLOW INTO
THE UPPER GREAT LAKES. OVERALL...THIS WILL BE A DRY PATTERN FOR
UPPER MI. TEMP FCST IS SOMEWHAT UNCERTAIN GIVEN THE MODEL
DISCREPENCIES...BUT TREND WILL BE TOWARD ABOVE NORMAL IN GENERAL.
BEGINNING THU...ALTHOUGH ERN TROF WILL BE IN THE PROCESS OF LIFTING
OUT...A SHORTWAVE WILL BE DROPPING SE TOWARD FAR NRN ONTARIO. THIS
WILL RESULT IN A MODEST WAA PATTERN ACROSS THE AREA THU. MODELS SHOW
A DRY COLUMN...SO PCPN IS NOT A CONCERN WITH THE WAA. IN FACT...THE
DAY WILL LIKELY BE MOSTLY SUNNY GIVEN THE DEGREE OF DRY AIR. WAA
WILL HELP TEMPS RISE INTO THE UPPER 50S/LWR 60S PER MIXING TO AROUND
850MB ON FCST SOUNDINGS.
AS SHORTWAVE CONTINUES SE...PASSING OVER THE SRN TIP OF JAMES BAY
FRI...A VERY WEAK SFC TROF WILL SINK S ACROSS THE AREA. WITH MAIN
DYNAMICS PASSING WELL TO THE NE AND A DRY AIR MASS REMAINING OVER
THE AREA...PCPN IS NOT AN ISSUE. 850MB TEMPS TO START THE DAY FRI
ARE 4-6C HIGHER THAN THE PREVIOUS DAY. MIXING TO AROUND 850MB YIELDS
MAX TEMPS AROUND 70F. LOOKS LIKE THERE MAY BE A FAIR AMOUNT OF MID
CLOUD FOR AT LEAST A PORTION OF THE DAY...SO HELD TEMPS GENERALLY TO
THE MID/UPPER 60S.
SHORTWAVE PASSING NEAR THE SRN TIP OF JAMES BAY FRI GETS LEFT BEHIND
OVER THE WEEKEND AS STRONG HEIGHT RISES OCCUR OVER SE CANADA IN THE
WAKE OF DEPARTING ERN TROF. AS THE SYSTEM BECOMES A BROADENING
MIDLEVEL LOW...THE HEIGHT RISES TO THE N END UP PUSHING SYSTEM S OR
SW. 00Z MODEL AGREEMENT IS NOT BAD WITH THE RANGE OF SOLUTIONS
SHOWING THE CENTER OF THE MID LEVEL LOW SOMEWHERE BTWN WRN LWR MI
(GLOBAL GEM) AND NW PA/WRN NY SUN (GFS). AT THIS POINT...THE
DIFFERENCES SEEN IN THE 00Z MODEL RUNS AND IN PREVIOUS RUNS WON`T
IMPACT FCST SIGNIFICANTLY. GIVEN THE DRY ORIGINATION OF THE SYSTEM
AND THE TIME IT WILL TAKE TO FULLY ENTRAIN DEEPER MOISTURE OFF THE
ATLANTIC...PCPN SHOULD NOT BE A CONCERN HERE. LOCATION OF THE MID
LEVEL LOW WILL HAVE MORE OF AN AFFECT ON TEMPS. THE FARTHER W GLOBAL
GEM SOLUTION WOULD BRING A COOLER AIR MASS INTO THE AREA FROM THE NE
FOR SUN (850MB TEMPS 3C E TO 5C W) WHILE THE FARTHER E GFS SOLUTION
WOULD MAINTAIN WARMER WEATHER THRU SUN (850MB TEMPS 4C E TO 10C W).
GIVEN THE VARYING SOLUTIONS OF RECENT DAYS...WILL STAY CLOSE TO A
BIAS CORRECTED CONSENSUS FCST UNTIL LOCATION OF MID LEVEL LOW IS
BETTER AGREED UPON. END RESULT IS HIGHS MAINLY IN THE 60S THIS
WEEKEND.
ECWMF/GFS HAVE STRUGGLED WITH THE PATTERN EARLY NEXT WEEK AS BOTH
MODELS HAVE VARIED FROM HAVING A RIDGE IN THE PACIFIC NW AND NW FLOW
INTO THE UPPER LAKES TO A TROF IN THE PACIFIC NW AND WSW FLOW INTO
THE UPPER LAKES. FOR THE MOMENT...THE 00Z RUNS FAVOR NW FLOW INTO
THE UPPER LAKES WHICH RESULTS IN A SHORTWAVE/COLD FRONT PASSING MON
AND PERHAPS ANOTHER LATE TUE. ONLY INCLUDED A SCHC OF -SHRA MON WITH
FIRST SHORTWAVE. TEMPS MON/TUE SHOULD BE MOSTLY IN THE 60S TO AROUND
70F.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 748 AM EDT WED SEP 26 2012
MODELS SEEM TO BE STRUGGLING ON THE AMOUNT OF LOW LEVEL MOISTURE
AND THUS HAVE UNCERTAINTY ON CIGS THIS MORNING. A SHORTWAVE HAS
PUSHED ACROSS UPPER MI THIS MORNING AND COLD AIR ON THE BACK SIDE
HAS LED TO SOME LK EFFECT CLOUDS AND SHOWERS DEVELOPING. LATEST OBS
INDICATE VFR CIGS AT ALL SITES IN THE UPPER GREAT LKS. WITH SOME
DIURNAL HEATING BETWEEN THE BREAKS IN THE CLOUDS...HAVE STILL TRENDED
TOWARDS A PERIOD OF SPORADIC...HIGH END MVFR CIGS DURING THE LATE
MORNING. HAVE ALSO MENTIONED VCSH AT KIWD/KSAW BASED OFF LATEST RADAR
RETURNS AND EXPECTED MOVEMENT.
HIGH PRESSURE WILL BUILD IN THIS AFTERNOON AND DECREASE CLOUDS FROM
WEST TO EAST. LIGHT WINDS AND CLEAR SKIES ARE EXPECTED TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT WED SEP 26 2012
HIGH PRES/WEAK PRES GRADIENT WILL GENERALLY DOMINATE FOR THE REST
OF THIS WEEK AND INTO THE WEEKEND. THIS WILL RESULT IN WINDS
UNDER 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1058 AM EDT WED SEP 26 2012
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL ACROSS THE REGION TODAY AS A
COLD FRONT SLIDES SOUTHEAST THROUGH THE AREA. BEHIND THE COLD
FRONT LATE TONIGHT...COOL AND DRY CONDITIONS WILL PREVAIL FOR
THURSDAY AS HIGH PRESSURE BUILDS INTO THE AREA. RAIN CHANCES
WILL ONCE AGAIN INCREASE TOWARDS THE END OF THE WEEK AS THE NEXT
SERIES OF DISTURBANCES IMPACT THE FORECAST REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...
MINOR CHANGES. AGAIN BACKED OFF ON THE PRECIP ONSET. SPRINKLES NOW
IN THE SW CWA BUT THIS CONTINUES TO DIE. MORE WAVES WILL DO BETTER
THIS AFTERNOON BRINGING RAINFALL TO THE ENTIRE CWA AHEAD OF A COLD
FRONT. TSTORM CHANCES CONTINUE TO LOOK LOW. SKIES SHOULD STAY
CLOUDY. SMALL NARROW CAPE WITH NO MID LEVEL DRYING. LEFT ISOLATED
T. BEST CHC WILL BE IN THE FAR S WHERE TEMPERATURES WILL BE
WARMEST AND THE FRONT WILL TAKE THE LONGEST TO GET TO.
640 AM UPDATE...
REGIONAL RADARS SHOWING AN AREA OF SHWRS/EMBEDDED THUNDER LIFTING
NORTHEAST TOWARDS OUR AREA FROM WESTERN PA. HIGH-RES MODELS TO
INCLUDE THE HRRR AND WRF-ARW SUGGEST THIS ACTIVITY WILL WEAKEN
WITH FURTHER EASTWARD PROGRESS. DESPITE THIS HOWEVER...HAVE
INCREASED POPS ACROSS THE SOUTHWEST FOR THE NEXT FEW HRS IN CASE
ACTIVITY HOLDS TOGETHER. BEYOND THIS...MAIN ACTIVITY IS EXPECTED
TO BE ALONG THE COLD FRONT AS IT SHIFTS SOUTH OVER OUR REGION
(DETAILS HIGHLIGHTED BELOW). IN ADDITION TO POP GRID
ADJUSTMENTS...MINOR TWEAKS ALSO MADE TO HOURLY TEMP AND DEWPOINT
GRIDS.
PREVIOUS NEAR TERM DISCUSSION...
EARLY MORNING RADAR IMAGERY SHOWING THE FIRST ROUND OF SHWRS
ASSOCIATED WITH SOUTHERN STREAM SHORTWAVE ENERGY AND WARM AIR
ADVECTION NOW WORKING THROUGH THE FCST AREA. TRAILING EDGE OF
SHWRS MOVING INTO THE CENTRAL FINGER LAKES THIS HR WITH UPSTREAM
RADAR TRENDS SUGGESTING WE/LL HAVE A FEW DRY HRS BEFORE THE NEXT
ROUND OF SHWRS DEVELOPS ALONG THE SOUTHWARD SAGGING COLD FRONT
LATER THIS MORNING/EARLY AFTERNOON. EXPANDING OUT...WATER VAPOR
IMAGERY SHOWING THE NORTHERN STREAM SHORTWAVE DIGGING SOUTHEAST
ACROSS THE WESTERN GREAT LAKES WITH MAIN STATIONARY BOUNDARY
ANALYZED FROM CENTRAL MI NORTHEAST INTO SOUTHERN ONTARIO AND
WESTERN QUEBEC. THIS FRONT IS FCST TO BEGIN SLIDING SOUTHEAST WITH
TIME AS MAIN NORTHERN STREAM SHORTWAVE ENERGY NOW ACROSS THE
WESTERN LAKES APPROACHES...SETTING THE STAGE FOR THE NEXT ROUND OF
SHWRS AND THE POSSIBILITY OF A THUNDERSTORM OR TWO LATER TODAY.
AS HAS BEEN HIGHLIGHTED IN RECENT FCST DISCUSSIONS...MUCH
UNCERTAINTY STILL REMAINS WITH RESPECT TO CONVECTIVE COVERAGE
LATER TODAY. MAIN CONCERNS ARE A RESULT OF MIXED SIGNALS FROM
VARIOUS SHORT TERM MODELS TO INCLUDE BOTH THE GFS AND WRF. THE
LATTER IN RECENT WEEKS HAS PERFORMED VERY POORLY WITH RESPECT TO
INSTABILITY FCST AND TODAY APPEARS TO BE ANOTHER REPEAT
PERFORMANCE AS THE LATEST RUN SUGGESTS UP TO 1000 JOULES OF MLCAPE
DEVELOPMENT LATER TODAY. THE GFS ON THE OTHER HAND ONLY SUGGESTS A
FEW HUNDRED JOULES AT BEST WHICH APPEARS MORE LIKELY CONSIDERING
ATMOSPHERE AHEAD OF THE FRONT WILL LIKELY BE "JUNKED UP" AS A
RESULT OF THIS MORNING/S SHWR ACTIVITY. THAT SAID...HAVE
MAINTAINED AN ISOLATED THUNDER MENTION FROM MAINLY THE STATE LINE
SOUTH AS BEST INSTABILITY GENERATION WILL BE ACROSS THESE AREAS.
DESPITE FAVORABLE WIND FIELDS ALOFT...THE LACK OF APPRECIABLE
INSTABILITY WILL KEEP ANY DEVELOPING CONVECTION FROM APPROACHING
SEVERE LIMITS.
RAIN TO QUICKLY COME TO AN END FROM NORTH TO SOUTH AFTER 00Z.
FOLLOWING THE DEPARTURE OF THE FRONT...VERY DRY AIR WILL QUICKLY
MOVE INTO THE AREA WHICH SHOULD PREVENT ANY LAKE RESPONSE DESPITE
LAKE/H85 TEMP DIFFERENCES APPROACHING 20C BY 12Z THU. ADDITIONALLY
LOW-LEVEL WIND PROFILES SUGGEST AMPLE AMOUNTS OF SHEAR WITHIN THE
INVERSION LAYER WHICH WILL ALSO BE UNFAVORABLE LAKE EFFECT RAIN
SHWRS.
TEMPS TODAY SHOULD WARM INTO THE UPPER 60S TO LOWER 70S AS WARM
AIR ADVECTION PERSISTS AHEAD OF THE COLD FRONT. TOOK A MET/MAV
BLEND AS RESIDUAL CLOUD COVER MAY KEEP TEMPS FROM WARMING TO THE
HIGHER VALUES AS SUGGESTED BY THE MET. BY TONIGHT...WITH CLEARING
SKIES ALOFT AND TEMPS EASILY FALLING INTO THE MIDDLE TO UPPER
40S...PATCHY VALLEY FOG DEVELOPMENT APPEARS LIKELY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
DRY AND COOLER CONDITIONS ARE EXPECTED ON THURSDAY AS HIGH
PRESSURE TEMPORARILY MOVES INTO THE REGION. WITH COLD AIR
ADVECTION PREVAILING OVER THE AREA...EXPECT HIGH TEMPS TO ONLY
REACH THE LOWER TO MIDDLE 60S.
FCST BECOMES A BIT MORE COMPLICATED BY THU NGT/EARLY FRI AS
SHORTWAVE ENERGY RIDES EAST ALONG A STALLED FRONT TO OUR SOUTH.
SHORT TERM MODELS INCREASE RAIN CHANCES DURING THIS PERIOD MAINLY
FOR AREAS SOUTH OF THE STATE LINE AS LINGERING HIGH PRESSURE AND
STRONG SFC RIDGING CONTINUE TO SUPPLY DRY AIR TO THE NORTHERN CWA.
HAVE SCALED PRECIP MENTION FURTHER SOUTH AS A RESULT OF THE SFC
RIDGING WHILE ALSO MAINTAINING A CHC MENTION FOR THE SOUTHERN
ZONES.
WEAK SFC LOW TO BEGIN WORKING UP THE MID-ATLANTIC COAST ON FRI
WHICH COMBINED WITH INCREASING DPVA ALOFT FROM APPROACHING POLAR
VORTEX ACROSS CENTRAL ONTARIO...WILL KEEP THE CHC FOR SHWRS
ACROSS THE ENTIRE REGION BOTH FRI AND FRI NGT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
430 AM UPDATE...
STALLED FRNTL BNDRY PRESENT TO THE SOUTH OF THE AREA WL BEGIN TO
PROGRESS NORTH AND EAST THRU THE WEEKEND AS A STRONG S/WV DROPS IN
ASSOC WITH UL TROF IN ERN CANADA...INDUCING SFC LOW DVLPMNT ALONG
THE MID-ATLANTIC COAST. THIS LOW WL RIDE ALONG THE FRONTAL
BNDRY...KEEPING UNSETTLED WX PRESENT THRU EARLY NEXT WEEK. MODELS
IN FAIRLY GOOD AGREEMENT WITH UA PATTERN THRU 00Z TUE THO THEY
DIFFER ON HOW FAR SOUTH AND HOW STRONG THE UL LOW WL BCM. GIVEN
THAT MODELS ARE CONSISTENT WITH EACH OTHER SEE NO REASON TO CHG
LONG TERM GRIDS AT THIS POINT WITH 30 POPS PRESENT SAT THRU MON IN
THE FORM OF SHOWERS. TEMPS WL BE RELATIVELY CLOSE TO NORMAL VALUES
THRU THE EXTNDD.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
MVFR CIGS WILL START OFF THE TAF PERIOD THIS MORNING. SOME
IMPROVEMENT EXPECTED THIS AFTERNOON. UPPER LEVEL DISTURBANCE WILL
MOVE IN FROM THE SOUTHWEST AND HELP TO DEVELOP MVFR SHOWERS LATER
THIS AFTERNOON IN COMBINATION WITH A COLD FRONT DROPPING SOUTH
THROUGH THE REGION. SHOWERS WILL CONTINUE THROUGH THE OVERNIGHT
HOURS AT KAVP BTWN 04Z-08Z. SKIES WILL CLEAR FROM NORTH TO
SOUTH AFTER 08Z...THEREFORE HAVE TEMPO/D IFR VSBYS INTO KELM
TOWARD DAYBREAK THURSDAY.
WINDS GNRLY OUT OF THE SW AROUND 10 KTS TODAY...TURNING OUT OF THE
NORTH AFTER FROPA.
OUTLOOK...
THU...VFR.
FRI TO SUN...GENERALLY VFR...BUT MVFR POSSIBLE IN SHOWERS AT
KAVP.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/TAC
NEAR TERM...CMG/TAC
SHORT TERM...CMG
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
707 AM EDT WED SEP 26 2012
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL ACROSS THE REGION TODAY AS A
COLD FRONT SLIDES SOUTH THROUGH THE AREA. FOLLOWING ITS DEPARTURE
LATER TONIGHT...COOL AND DRY CONDITIONS WILL PREVAIL THROUGH
THURSDAY AS HIGH PRESSURE BUILDS INTO THE AREA. RAIN CHANCES WILL
ONCE AGAIN INCREASE TOWARDS THE END OF THE WEEK AS THE NEXT SERIES
OF DISTURBANCES IMPACT THE FORECAST REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
640 AM UPDATE...
REGIONAL RADARS SHOWING AN AREA OF SHWRS/EMBEDDED THUNDER LIFTING
NORTHEAST TOWARDS OUR AREA FROM WESTERN PA. HIGH-RES MODELS TO
INCLUDE THE HRRR AND WRF-ARW SUGGEST THIS ACTIVITY WILL WEAKEN
WITH FURTHER EASTWARD PROGRESS. DESPITE THIS HOWEVER...HAVE
INCREASED POPS ACROSS THE SOUTHWEST FOR THE NEXT FEW HRS IN CASE
ACTIVITY HOLDS TOGETHER. BEYOND THIS...MAIN ACTIVITY IS EXPECTED
TO BE ALONG THE COLD FRONT AS IT SHIFTS SOUTH OVER OUR REGION
(DETAILS HIGHLIGHTED BELOW). IN ADDITION TO POP GRID
ADJUSTMENTS...MINOR TWEAKS ALSO MADE TO HOURLY TEMP AND DEWPOINT
GRIDS.
PREVIOUS NEAR TERM DISCUSSION...
EARLY MORNING RADAR IMAGERY SHOWING THE FIRST ROUND OF SHWRS
ASSOCIATED WITH SOUTHERN STREAM SHORTWAVE ENERGY AND WARM AIR
ADVECTION NOW WORKING THROUGH THE FCST AREA. TRAILING EDGE OF
SHWRS MOVING INTO THE CENTRAL FINGER LAKES THIS HR WITH UPSTREAM
RADAR TRENDS SUGGESTING WE/LL HAVE A FEW DRY HRS BEFORE THE NEXT
ROUND OF SHWRS DEVELOPS ALONG THE SOUTHWARD SAGGING COLD FRONT
LATER THIS MORNING/EARLY AFTERNOON. EXPANDING OUT...WATER VAPOR
IMAGERY SHOWING THE NORTHERN STREAM SHORTWAVE DIGGING SOUTHEAST
ACROSS THE WESTERN GREAT LAKES WITH MAIN STATIONARY BOUNDARY
ANALYZED FROM CENTRAL MI NORTHEAST INTO SOUTHERN ONTARIO AND
WESTERN QUEBEC. THIS FRONT IS FCST TO BEGIN SLIDING SOUTHEAST WITH
TIME AS MAIN NORTHERN STREAM SHORTWAVE ENERGY NOW ACROSS THE
WESTERN LAKES APPROACHES...SETTING THE STAGE FOR THE NEXT ROUND OF
SHWRS AND THE POSSIBILITY OF A THUNDERSTORM OR TWO LATER TODAY.
AS HAS BEEN HIGHLIGHTED IN RECENT FCST DISCUSSIONS...MUCH
UNCERTAINTY STILL REMAINS WITH RESPECT TO CONVECTIVE COVERAGE
LATER TODAY. MAIN CONCERNS ARE A RESULT OF MIXED SIGNALS FROM
VARIOUS SHORT TERM MODELS TO INCLUDE BOTH THE GFS AND WRF. THE
LATTER IN RECENT WEEKS HAS PERFORMED VERY POORLY WITH RESPECT TO
INSTABILITY FCST AND TODAY APPEARS TO BE ANOTHER REPEAT
PERFORMANCE AS THE LATEST RUN SUGGESTS UP TO 1000 JOULES OF MLCAPE
DEVELOPMENT LATER TODAY. THE GFS ON THE OTHER HAND ONLY SUGGESTS A
FEW HUNDRED JOULES AT BEST WHICH APPEARS MORE LIKELY CONSIDERING
ATMOSPHERE AHEAD OF THE FRONT WILL LIKELY BE "JUNKED UP" AS A
RESULT OF THIS MORNING/S SHWR ACTIVITY. THAT SAID...HAVE
MAINTAINED AN ISOLATED THUNDER MENTION FROM MAINLY THE STATE LINE
SOUTH AS BEST INSTABILITY GENERATION WILL BE ACROSS THESE AREAS.
DESPITE FAVORABLE WIND FIELDS ALOFT...THE LACK OF APPRECIABLE
INSTABILITY WILL KEEP ANY DEVELOPING CONVECTION FROM APPROACHING
SEVERE LIMITS.
RAIN TO QUICKLY COME TO AN END FROM NORTH TO SOUTH AFTER 00Z.
FOLLOWING THE DEPARTURE OF THE FRONT...VERY DRY AIR WILL QUICKLY
MOVE INTO THE AREA WHICH SHOULD PREVENT ANY LAKE RESPONSE DESPITE
LAKE/H85 TEMP DIFFERENCES APPROACHING 20C BY 12Z THU. ADDITIONALLY
LOW-LEVEL WIND PROFILES SUGGEST AMPLE AMOUNTS OF SHEAR WITHIN THE
INVERSION LAYER WHICH WILL ALSO BE UNFAVORABLE LAKE EFFECT RAIN
SHWRS.
TEMPS TODAY SHOULD WARM INTO THE UPPER 60S TO LOWER 70S AS WARM
AIR ADVECTION PERSISTS AHEAD OF THE COLD FRONT. TOOK A MET/MAV
BLEND AS RESIDUAL CLOUD COVER MAY KEEP TEMPS FROM WARMING TO THE
HIGHER VALUES AS SUGGESTED BY THE MET. BY TONIGHT...WITH CLEARING
SKIES ALOFT AND TEMPS EASILY FALLING INTO THE MIDDLE TO UPPER
40S...PATCHY VALLEY FOG DEVELOPMENT APPEARS LIKELY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
DRY AND COOLER CONDITIONS ARE EXPECTED ON THURSDAY AS HIGH
PRESSURE TEMPORARILY MOVES INTO THE REGION. WITH COLD AIR
ADVECTION PREVAILING OVER THE AREA...EXPECT HIGH TEMPS TO ONLY
REACH THE LOWER TO MIDDLE 60S.
FCST BECOMES A BIT MORE COMPLICATED BY THU NGT/EARLY FRI AS
SHORTWAVE ENERGY RIDES EAST ALONG A STALLED FRONT TO OUR SOUTH.
SHORT TERM MODELS INCREASE RAIN CHANCES DURING THIS PERIOD MAINLY
FOR AREAS SOUTH OF THE STATE LINE AS LINGERING HIGH PRESSURE AND
STRONG SFC RIDGING CONTINUE TO SUPPLY DRY AIR TO THE NORTHERN CWA.
HAVE SCALED PRECIP MENTION FURTHER SOUTH AS A RESULT OF THE SFC
RIDGING WHILE ALSO MAINTAINING A CHC MENTION FOR THE SOUTHERN
ZONES.
WEAK SFC LOW TO BEGIN WORKING UP THE MID-ATLANTIC COAST ON FRI
WHICH COMBINED WITH INCREASING DPVA ALOFT FROM APPROACHING POLAR
VORTEX ACROSS CENTRAL ONTARIO...WILL KEEP THE CHC FOR SHWRS
ACROSS THE ENTIRE REGION BOTH FRI AND FRI NGT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
430 AM UPDATE...
STALLED FRNTL BNDRY PRESENT TO THE SOUTH OF THE AREA WL BEGIN TO
PROGRESS NORTH AND EAST THRU THE WEEKEND AS A STRONG S/WV DROPS IN
ASSOC WITH UL TROF IN ERN CANADA...INDUCING SFC LOW DVLPMNT ALONG
THE MID-ATLANTIC COAST. THIS LOW WL RIDE ALONG THE FRONTAL
BNDRY...KEEPING UNSETTLED WX PRESENT THRU EARLY NEXT WEEK. MODELS
IN FAIRLY GOOD AGREEMENT WITH UA PATTERN THRU 00Z TUE THO THEY
DIFFER ON HOW FAR SOUTH AND HOW STRONG THE UL LOW WL BCM. GIVEN
THAT MODELS ARE CONSISTENT WITH EACH OTHER SEE NO REASON TO CHG
LONG TERM GRIDS AT THIS POINT WITH 30 POPS PRESENT SAT THRU MON IN
THE FORM OF SHOWERS. TEMPS WL BE RELATIVELY CLOSE TO NORMAL VALUES
THRU THE EXTNDD.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
MVFR CIGS WILL START OFF THE TAF PERIOD THIS MORNING. SOME
IMPROVEMENT EXPECTED THIS AFTERNOON. UPPER LEVEL DISTURBANCE WILL
MOVE IN FROM THE SOUTHWEST AND HELP TO DEVELOP MVFR SHOWERS LATER
THIS AFTERNOON IN COMBINATION WITH A COLD FRONT DROPPING SOUTH
THROUGH THE REGION. SHOWERS WILL CONTINUE THROUGH THE OVERNIGHT
HOURS AT KAVP BTWN 04Z-08Z. SKIES WILL CLEAR FROM NORTH TO
SOUTH AFTER 08Z...THEREFORE HAVE TEMPO/D IFR VSBYS INTO KELM
TOWARD DAYBREAK THURSDAY.
WINDS GNRLY OUT OF THE SW AROUND 10 KTS TODAY...TURNING OUT OF THE
NORTH AFTER FROPA.
OUTLOOK...
THU...VFR.
FRI TO SUN...GENERALLY VFR...BUT MVFR POSSIBLE IN SHOWERS AT
KAVP.
&&
.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
644 AM EDT WED SEP 26 2012
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL ACROSS THE REGION TODAY AS A
COLD FRONT SLIDES SOUTH THROUGH THE AREA. FOLLOWING ITS DEPARTURE
LATER TONIGHT...COOL AND DRY CONDITIONS WILL PREVAIL THROUGH
THURSDAY AS HIGH PRESSURE BUILDS INTO THE AREA. RAIN CHANCES WILL
ONCE AGAIN INCREASE TOWARDS THE END OF THE WEEK AS THE NEXT SERIES
OF DISTURBANCES IMPACT THE FORECAST REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
640 AM UPDATE...
REGIONAL RADARS SHOWING AN AREA OF SHWRS/EMBEDDED THUNDER LIFTING
NORTHEAST TOWARDS OUR AREA FROM WESTERN PA. HIGH-RES MODELS TO
INCLUDE THE HRRR AND WRF-ARW SUGGEST THIS ACTIVITY WILL WEAKEN
WITH FURTHER EASTWARD PROGRESS. DESPITE THIS HOWEVER...HAVE
INCREASED POPS ACROSS THE SOUTHWEST FOR THE NEXT FEW HRS IN CASE
ACTIVITY HOLDS TOGETHER. BEYOND THIS...MAIN ACTIVITY IS EXPECTED
TO BE ALONG THE COLD FRONT AS IT SHIFTS SOUTH OVER OUR REGION
(DETAILS HIGHLIGHTED BELOW). IN ADDITION TO POP GRID
ADJUSTMENTS...MINOR TWEAKS ALSO MADE TO HOURLY TEMP AND DEWPOINT
GRIDS.
PREVIOUS NEAR TERM DISCUSSION...
EARLY MORNING RADAR IMAGERY SHOWING THE FIRST ROUND OF SHWRS
ASSOCIATED WITH SOUTHERN STREAM SHORTWAVE ENERGY AND WARM AIR
ADVECTION NOW WORKING THROUGH THE FCST AREA. TRAILING EDGE OF
SHWRS MOVING INTO THE CENTRAL FINGER LAKES THIS HR WITH UPSTREAM
RADAR TRENDS SUGGESTING WE/LL HAVE A FEW DRY HRS BEFORE THE NEXT
ROUND OF SHWRS DEVELOPS ALONG THE SOUTHWARD SAGGING COLD FRONT
LATER THIS MORNING/EARLY AFTERNOON. EXPANDING OUT...WATER VAPOR
IMAGERY SHOWING THE NORTHERN STREAM SHORTWAVE DIGGING SOUTHEAST
ACROSS THE WESTERN GREAT LAKES WITH MAIN STATIONARY BOUNDARY
ANALYZED FROM CENTRAL MI NORTHEAST INTO SOUTHERN ONTARIO AND
WESTERN QUEBEC. THIS FRONT IS FCST TO BEGIN SLIDING SOUTHEAST WITH
TIME AS MAIN NORTHERN STREAM SHORTWAVE ENERGY NOW ACROSS THE
WESTERN LAKES APPROACHES...SETTING THE STAGE FOR THE NEXT ROUND OF
SHWRS AND THE POSSIBILITY OF A THUNDERSTORM OR TWO LATER TODAY.
AS HAS BEEN HIGHLIGHTED IN RECENT FCST DISCUSSIONS...MUCH
UNCERTAINTY STILL REMAINS WITH RESPECT TO CONVECTIVE COVERAGE
LATER TODAY. MAIN CONCERNS ARE A RESULT OF MIXED SIGNALS FROM
VARIOUS SHORT TERM MODELS TO INCLUDE BOTH THE GFS AND WRF. THE
LATTER IN RECENT WEEKS HAS PERFORMED VERY POORLY WITH RESPECT TO
INSTABILITY FCST AND TODAY APPEARS TO BE ANOTHER REPEAT
PERFORMANCE AS THE LATEST RUN SUGGESTS UP TO 1000 JOULES OF MLCAPE
DEVELOPMENT LATER TODAY. THE GFS ON THE OTHER HAND ONLY SUGGESTS A
FEW HUNDRED JOULES AT BEST WHICH APPEARS MORE LIKELY CONSIDERING
ATMOSPHERE AHEAD OF THE FRONT WILL LIKELY BE "JUNKED UP" AS A
RESULT OF THIS MORNING/S SHWR ACTIVITY. THAT SAID...HAVE
MAINTAINED AN ISOLATED THUNDER MENTION FROM MAINLY THE STATE LINE
SOUTH AS BEST INSTABILITY GENERATION WILL BE ACROSS THESE AREAS.
DESPITE FAVORABLE WIND FIELDS ALOFT...THE LACK OF APPRECIABLE
INSTABILITY WILL KEEP ANY DEVELOPING CONVECTION FROM APPROACHING
SEVERE LIMITS.
RAIN TO QUICKLY COME TO AN END FROM NORTH TO SOUTH AFTER 00Z.
FOLLOWING THE DEPARTURE OF THE FRONT...VERY DRY AIR WILL QUICKLY
MOVE INTO THE AREA WHICH SHOULD PREVENT ANY LAKE RESPONSE DESPITE
LAKE/H85 TEMP DIFFERENCES APPROACHING 20C BY 12Z THU. ADDITIONALLY
LOW-LEVEL WIND PROFILES SUGGEST AMPLE AMOUNTS OF SHEAR WITHIN THE
INVERSION LAYER WHICH WILL ALSO BE UNFAVORABLE LAKE EFFECT RAIN
SHWRS.
TEMPS TODAY SHOULD WARM INTO THE UPPER 60S TO LOWER 70S AS WARM
AIR ADVECTION PERSISTS AHEAD OF THE COLD FRONT. TOOK A MET/MAV
BLEND AS RESIDUAL CLOUD COVER MAY KEEP TEMPS FROM WARMING TO THE
HIGHER VALUES AS SUGGESTED BY THE MET. BY TONIGHT...WITH CLEARING
SKIES ALOFT AND TEMPS EASILY FALLING INTO THE MIDDLE TO UPPER
40S...PATCHY VALLEY FOG DEVELOPMENT APPEARS LIKELY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
DRY AND COOLER CONDITIONS ARE EXPECTED ON THURSDAY AS HIGH
PRESSURE TEMPORARILY MOVES INTO THE REGION. WITH COLD AIR
ADVECTION PREVAILING OVER THE AREA...EXPECT HIGH TEMPS TO ONLY
REACH THE LOWER TO MIDDLE 60S.
FCST BECOMES A BIT MORE COMPLICATED BY THU NGT/EARLY FRI AS
SHORTWAVE ENERGY RIDES EAST ALONG A STALLED FRONT TO OUR SOUTH.
SHORT TERM MODELS INCREASE RAIN CHANCES DURING THIS PERIOD MAINLY
FOR AREAS SOUTH OF THE STATE LINE AS LINGERING HIGH PRESSURE AND
STRONG SFC RIDGING CONTINUE TO SUPPLY DRY AIR TO THE NORTHERN CWA.
HAVE SCALED PRECIP MENTION FURTHER SOUTH AS A RESULT OF THE SFC
RIDGING WHILE ALSO MAINTAINING A CHC MENTION FOR THE SOUTHERN
ZONES.
WEAK SFC LOW TO BEGIN WORKING UP THE MID-ATLANTIC COAST ON FRI
WHICH COMBINED WITH INCREASING DPVA ALOFT FROM APPROACHING POLAR
VORTEX ACROSS CENTRAL ONTARIO...WILL KEEP THE CHC FOR SHWRS
ACROSS THE ENTIRE REGION BOTH FRI AND FRI NGT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
430 AM UPDATE...
STALLED FRNTL BNDRY PRESENT TO THE SOUTH OF THE AREA WL BEGIN TO
PROGRESS NORTH AND EAST THRU THE WEEKEND AS A STRONG S/WV DROPS IN
ASSOC WITH UL TROF IN ERN CANADA...INDUCING SFC LOW DVLPMNT ALONG
THE MID-ATLANTIC COAST. THIS LOW WL RIDE ALONG THE FRONTAL
BNDRY...KEEPING UNSETTLED WX PRESENT THRU EARLY NEXT WEEK. MODELS
IN FAIRLY GOOD AGREEMENT WITH UA PATTERN THRU 00Z TUE THO THEY
DIFFER ON HOW FAR SOUTH AND HOW STRONG THE UL LOW WL BCM. GIVEN
THAT MODELS ARE CONSISTENT WITH EACH OTHER SEE NO REASON TO CHG
LONG TERM GRIDS AT THIS POINT WITH 30 POPS PRESENT SAT THRU MON IN
THE FORM OF SHOWERS. TEMPS WL BE RELATIVELY CLOSE TO NORMAL VALUES
THRU THE EXTNDD.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR AT ALL TERMINALS TO BEGIN THE TAF PERIOD. HOWEVER...THIS WILL
QUICKLY DETERIORATE AT MOST LOCATIONS TO MVFR BETWEEN 06Z AND 12Z.
LIGHT SHOWERS WILL BE POSSIBLE OFF AND ON THROUGH 09Z BEFORE
ENDING BRIEFLY. IFR CIGS WILL BE POSSIBLE AT HIGHER TERMINALS OF
KITH/KBGM. CIGS WILL LIFT BY 14Z AT MOST TERMINALS WITH A BRIEF
BREAK IN THE SHOWER ACTIVITY. MORE SHOWERS ARE EXPECTED TO MOVE IN
AFTER 18Z WITH MOST LIKELY LOCATION AT KAVP WHERE CDFNT INTERACTS
WITH MOST INSTABILITY.
WINDS TNGT GNRLY SRLY 5-10 KTS...SWLY ON WED 10-20 KTS.
OUTLOOK...
THUR MORNING...MVFR/IFR FOG POSSIBLE ESPECIALLY KELM.
THU...VFR.
FRI TO SUN...GENERALLY VFR...BUT MVFR POSSIBLE IN SHOWERS AT
KAVP.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...PVN/TAC
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1056 AM EDT WED SEP 26 2012
.SYNOPSIS...
PERIODS OF RAIN CAN BE EXPECTED INTO THE EARLY EVENING UNTIL A
FRONTAL BOUNDARY PUSHES SOUTH AND EAST. THE FRONT WILL STALL OUT
NEAR THE MASON DIXON LINE THURSDAY AND FRIDAY...WITH THE THREAT OF
RAIN PERSISTING MAINLY OVER THE SOUTHERN THIRD OF THE KEYSTONE
STATE. A DEEP UPPER LEVEL TROUGH IS FORECAST TO DROP SOUTHWARD
FROM EASTERN CANADA AND CARVE OUT OVER THE GREAT LAKES REGION AND
NORTHEAST STATES THIS WEEKEND.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
11 AM UPDATE...
SHOWERS CONTINUE TO SLIDE EASTWARD. SOLID CLOUD COVER OVER THE
NRN/NWRN TWO-THIRDS OF THE AREA SHOULD CONTINUE...OR ONLY SHOW
MINOR BREAKS THIS AFTERNOON AND EARLY THIS EVENING. BUT...JUST
ENOUGH DESTABILIZATION WITH INFLUX OF HIGHER THETA-E AIR WILL KEEP
THE CHC OF THUNDER IN THE NORTHWEST...AND THE SUNSHINE AND FORCING
MECHANISMS MENTIONED PREVIOUSLY WILL HOLD THE FCST AS IS IN THE
SOUTH. FORECAST REMAINS VERY HIGH IN CONTINUITY WITH ONLY MINOR
TWEAKS TO TIMING OF PRECIP.
9 AM UPDATE...
MULTIPLE VORTICIES /MOST LIKELY MCV LEFT OVER FROM OH VALLEY
CONVECTION/ MOVING THRU SRN OH AND SRN INDIANA ARE VISIBLE IN BOTH
VIS SHOTS FROM GOES-14 AND IN THE RADAR MOSAIC. THESE CYCLONIC
TWISTS WILL PROVIDE FORCING FOR ADDITION THUNDERSTORMS THIS AFTN.
SPC HAS JUST UPGRADED THE SRN TIER INTO SLIGHT RISK FOR
TODAY...CONSISTENT WITH THE FORCING AND EXPECTED HEATING. LOTS OF
BREAKS IN THE CLOUDS IN SRN SECTIONS OF THE AREA RIGHT NOW...BUT
THESE COULD CLOSE UP AS BLOW OFF FROM THE STORMS TO THE WEST FLOW
OVERHEAD. IF THE SUNSHINE PERSISTS...SRN AREAS WILL GET SLIGHTLY
WARMER THAN FCST...BUT WILL HOLD THE COURSE FOR NOW.
PREV DSIC FOLLOWS...
S/W EVIDENT OVR SERN OH/NRN WV PER RADAR/SATL IMAGERY IS
COMBINING WITH 40-50KT WSWLY LLJ /ILM VWP/ AND AXIS OF HI PWATS TO
PRODUCE AN AREA OF SHOWERS WITH EMBEDDED ELEVATED THUNDER FROM THE
LAUREL HIGHLANDS NWWD TO CLEVELAND. THE LATEST HRRR TAKES THE BULK
OF THE SHOWERS ACRS THE S-CENTRAL MTNS BTWN 09-12Z...WEAKENING
WITH EWD EXTENT AS THEY MOVE AWAY FROM THE NOSE OF LLJ AND REACH
THE LWR SUSQ VLY BY DAYBREAK. FURTHER NORTH TO THE I-80
CORRIDOR..EXPECT CVRG OF SHOWERS TO BE MORE SCT IN NATURE WITH THE
BEST CHC FOR RAIN EARLY THIS MORNING WEST OF A LINE FROM UNV-BFD.
THERE SHOULD BE SOMEWHAT OF A BREAK IN THE PCPN THRU MID
MORNING...BUT THERE WILL STILL BE SOME SHOWERS AROUND THE AREA.
THE NEXT WAVE APPEARS TO BE MOVG THRU CVG ATTM AND WILL LKLY BE
THE CATALYST FOR THE NEXT ROUND OF SHOWERS ACRS WRN PA BY EARLY
AFTN.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE MAIN SYNOPTIC COLD FRONT WILL PRESS SEWD LATE TONIGHT AND
EVENTUALLY STALL OUT NEAR THE PA/MD BORDER INTO THURS. NLY LLVL
FLOW WILL ADVECT A MUCH DRIER AIRMASS INTO THE NRN PART OF THE CWA
TONIGHT...WHICH SHOULD ENSURE A DRY OVERNIGHT PERIOD.
HOWEVER...SRN PA WILL LKLY CONT TO HAVE SHOWERS AS MSTR AXIS
REMAINS IN PLACE ALONG STALLED E-W FRONTAL ZONE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER TROF OVER SOUTHEAST CANADA AND THE NORTHEASTERN UNITED
STATES WILL LIFT OUT THURSDAY NIGHT AND FRIDAY IN FAVOR OF A
STRONGER UPPER TROF DIGGING SHARPLY SOUTHWARD THROUGH ONTARIO AND
CUTTING OFF OVER THE CENTRAL AND EASTERN GREAT LAKES LATE SATURDAY
AND SUNDAY. THIS WILL BRING SHORTLIVED IMPROVING CONDITIONS TO THE
REGION ON THURSDAY BEFORE INCREASINGLY UNSETTLED CONDITIONS RETURN
FOR LATER SATURDAY AND SUNDAY OVER CENTRAL PA.
GFS AND ECMWF ARE SIMILAR IN OVERALL SYNOPTIC EVOLUTION LATE THIS
WEEK AND THIS WEEKEND...WITH THE GFS DECIDEDLY FAVORING QPF
FARTHER TO THE EAST AS THE UPPER LOW CUTS OFF OVER THE CENTRAL AND
EASTERN GLAKS. ECMWF APPEARS MORE REALISTIC IN ITS DEPICTION OF
SCT TO NMRS SHOWERS IN THIS REGIME. SUBTROPICAL MOISTURE PLUME IS
DISPLACED WELL TO THE EAST OF OF THE MID ATLANTIC COAST AND IT
APPEARS WILL HAVE LITTLE INTERACTION WITH THE SAT-SUN CUTOFF AND
RESULTANT PRECIPITATION ACROSS THE REGION...SO HEAVY RAIN THREAT
IS FAIRLY LOW. GFS ENSEMBLE IS EVIDENCE OF THIS...WITH 24 HOUR
PROBABILITIES OF GREATER THAN 1 INCH IN THE SAT-SUN TIMEFRAME ONLY
TOPPING OUT AT 30 PERCENT OVER CENTRAL AND NORTHERN NJ AND WESTERN
LONG ISLAND.
THE OVERALL LONGWAVE PATTERN EVOLUTION WILL KEEP THE POTENTIAL OF
SHOWERS SOMEWHERE IN CENTRAL PA EACH DAY FROM FRIDAY ONWARD. WHILE
NO THREAT OF HEAVY RAINFALL IS SEEN AT THIS TIME...IT DOES NOT
APPEAR THAT DRIER CONDITIONS WILL RETURN UNTIL THE END OF THIS
PERIOD OF SHORTLY THEREAFTER.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
26/15Z...NO CHANGES TO PREV FCST REASONING. DID ADD VCTS TO
JST/AOO FOR THE AFTERNOON. WILL CONSIDER ADDING TO MDT/LNS WITH
NEXT UPDATE.
26/12Z...IN ADVANCE OF SFC COLD FRONT PUSHING SLOWLY SEWD ACRS THE
MIDWEST...COMBINATION OF STRONG MSTR TRANSPORT VIA SWLY LLJ AND
BROAD VERTICAL LIFT ASSOC WITH MID- UPPER TROUGH MOVG EWD ACRS
SERN CANADA WILL SUPPORT NMRS RAIN/SHOWERS ACROSS CENTRAL PA
THROUGH TONIGHT. THE FRONTAL ZONE WILL SHIFT SLOWLY SEWD ACRS THE
AREA THRU EARLY THURS MORNING BEFORE STALLING OUT NEAR THE PA/MD
BORDER INTO FRIDAY. CURRENT RADAR SHOWS BAND OF RAIN MOVG NEWD
THRU CENTRAL PA...IMPACTING LNS/MDT/UNV/BFD BTWN 12-13Z AND IPT
BTWN 13-15Z. FQNT SHOWERS ARE EXPECTED THROUGH THE AFTN...WITH AN
ISOLD TSTM PSBL MAINLY OVR THE SRN TERMINALS. IFR CIGS SHOULD
CONTINUE THRU THE MORNING HOURS AT BFD. SSW WIND AT JST FAVORS
MVFR OVER IFR..BUT WILL KEEP IFR THRU 15Z. ELSEWHERE...EXPECT MVFR
TO VFR CONDS TO PREVAIL.
OUTLOOK...
THU...VFR NORTH/MVFR SOUTH. SHOWERS LKLY SRN AIRFIELDS.
FRI-SUN...VFR TO MVFR WITH SCT SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...DANGELO/STEINBUGL
LONG TERM...DEVOIR/LA CORTE/GARTNER
AVIATION...DANGELO/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
852 AM EDT WED SEP 26 2012
.SYNOPSIS...
PERIODS OF RAIN CAN BE EXPECTED TODAY ACROSS MUCH OF CENTRAL
PENNSYLVANIA...IN ADVANCE OF A FRONTAL BOUNDARY PUSHING SLOWLY
SOUTHEAST THROUGH THE LOWER GREAT LAKES AND OHIO VALLEY. THE
FRONT WILL STALL OUT NEAR THE MASON DIXON LINE THURSDAY AND
FRIDAY...WITH THE THREAT OF RAIN PERSISTING MAINLY OVER THE
SOUTHERN THIRD OF THE KEYSTONE STATE. A DEEP UPPER LEVEL TROUGH
IS FORECAST TO DROP SOUTHWARD FROM EASTERN CANADA AND CARVE OUT
OVER THE GREAT LAKES REGION AND NORTHEAST STATES THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
9AM UPDATE...
MULTIPLE VORTICIES /MOST LIKELY MCV LEFT OVER FROM OH VALLEY
CONVECTION/ MOVING THRU SRN OH AND SRN INDIANA ARE VISIBLE IN
BOTH VIS SHOTS FROM GOES-14 AND IN THE RADAR MOSAIC. THESE
CYCLONIC TWISTS WILL PROVIDE FORCING FOR ADDITION THUNDERSTORMS
THIS AFTN. SPC HAS JUST UPGRADED THE SRN TIER INTO SLIGHT RISK FOR
TODAY...CONSISTENT WITH THE FORCING AND EXPECTED HEATING. LOTS OF
BREAKS IN THE CLOUDS IN SRN SECTIONS OF THE AREA RIGHT NOW...BUT
THESE COULD CLOSE UP AS BLOW OFF FROM THE STORMS TO THE WEST FLOW
OVERHEAD. IF THE SUNSHINE PERSISTS...SRN AREAS WILL GET SLIGHTLY
WARMER THAN FCST...BUT WILL HOLD THE COURSE FOR NOW.
PREV DSIC FOLLOWS...
S/W EVIDENT OVR SERN OH/NRN WV PER RADAR/SATL IMAGERY IS
COMBINING WITH 40-50KT WSWLY LLJ /ILM VWP/ AND AXIS OF HI PWATS TO
PRODUCE AN AREA OF SHOWERS WITH EMBEDDED ELEVATED THUNDER FROM THE
LAUREL HIGHLANDS NWWD TO CLEVELAND. THE LATEST HRRR TAKES THE BULK
OF THE SHOWERS ACRS THE S-CENTRAL MTNS BTWN 09-12Z...WEAKENING
WITH EWD EXTENT AS THEY MOVE AWAY FROM THE NOSE OF LLJ AND REACH
THE LWR SUSQ VLY BY DAYBREAK. FURTHER NORTH TO THE I-80
CORRIDOR..EXPECT CVRG OF SHOWERS TO BE MORE SCT IN NATURE WITH THE
BEST CHC FOR RAIN EARLY THIS MORNING WEST OF A LINE FROM UNV-BFD.
THERE SHOULD BE SOMEWHAT OF A BREAK IN THE PCPN THRU MID
MORNING...BUT THERE WILL STILL BE SOME SHOWERS AROUND THE AREA.
THE NEXT WAVE APPEARS TO BE MOVG THRU CVG ATTM AND WILL LKLY BE
THE CATALYST FOR THE NEXT ROUND OF SHOWERS ACRS WRN PA BY EARLY
AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
ALTHOUGH THE MDLS SOLUTIONS DISAGREE ON THE FINER QPF DETAILS OF
THE FCST EVEN AT 6 HRLY TIME STEPS...THEY ARE OTHERWISE IN PRETTY
GOOD AGREEMENT ON A RNFL AXIS SETTING UP ALONG DEEP MSTR AXIS
STRADDLING THE OH RVR AND EXTENDING ENEWD ACRS SW/S-CENTRAL PA.
WAA/ISENT LIFT VIA STG WSWLY LLJ ALONG WITH ENHANCED LG SCALE LIFT
NEAR RIGHT ENT REGION OF UPPER JET WILL SUPPORT PERIODS OF RAIN
INTO TONIGHT. CLOUD COVER SHOULD LIMIT INSTABILITY BUT SCT TSTMS
CANNOT BE RULED OUT THIS EVENING...ESPECIALLY OVR SRN PA WHERE
SREF SHOWS THE GREATEST POTENTIAL FOR DESTABILIZATION. MOD/HVY
RNFL AXIS FROM THE OH VLY SHOULD STRETCH INTO SW PA/LAURELS WITH
D1 24HR QPF AMTS NEAR 1 INCH IN THE JST/AOO AREA. FOLLOWED BLEND
MORE IN-LINE WITH ECMWF/CANADIAN/UKMET AS GFS DOES NOT APPEAR TO
HAVE A GOOD HANDLE ON CURRENT EVOLUTION OF PCPN.
THE MAIN SYNOPTIC COLD FRONT WILL PRESS SEWD LATE TONIGHT AND
EVENTUALLY STALL OUT NEAR THE PA/MD BORDER INTO THURS. NLY LLVL
FLOW WILL ADVECT A MUCH DRIER AIRMASS INTO THE NRN PART OF THE CWA
TONIGHT...WHICH SHOULD ENSURE A DRY OVERNIGHT PERIOD.
HOWEVER...SRN PA WILL LKLY CONT TO HAVE SHOWERS AS MSTR AXIS
REMAINS IN PLACE ALONG STALLED E-W FRONTAL ZONE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER TROF OVER SOUTHEAST CANADA AND THE NORTHEASTERN UNITED
STATES WILL LIFT OUT THURSDAY NIGHT AND FRIDAY IN FAVOR OF A
STRONGER UPPER TROF DIGGING SHARPLY SOUTHWARD THROUGH ONTARIO AND
CUTTING OFF OVER THE CENTRAL AND EASTERN GREAT LAKES LATE SATURDAY
AND SUNDAY. THIS WILL BRING SHORTLIVED IMPROVING CONDITIONS TO THE
REGION ON THURSDAY BEFORE INCREASINGLY UNSETTLED CONDITIONS RETURN
FOR LATER SATURDAY AND SUNDAY OVER CENTRAL PA.
GFS AND ECMWF ARE SIMILAR IN OVERALL SYNOPTIC EVOLUTION LATE THIS
WEEK AND THIS WEEKEND...WITH THE GFS DECIDEDLY FAVORING QPF
FARTHER TO THE EAST AS THE UPPER LOW CUTS OFF OVER THE CENTRAL AND
EASTERN GLAKS. ECMWF APPEARS MORE REALISTIC IN ITS DEPICTION OF
SCT TO NMRS SHOWERS IN THIS REGIME. SUBTROPICAL MOISTURE PLUME IS
DISPLACED WELL TO THE EAST OF OF THE MID ATLANTIC COAST AND IT
APPEARS WILL HAVE LITTLE INTERACTION WITH THE SAT-SUN CUTOFF AND
RESULTANT PRECIPITATION ACROSS THE REGION...SO HEAVY RAIN THREAT
IS FAIRLY LOW. GFS ENSEMBLE IS EVIDENCE OF THIS...WITH 24 HOUR
PROBABILITIES OF GREATER THAN 1 INCH IN THE SAT-SUN TIMEFRAME ONLY
TOPPING OUT AT 30 PERCENT OVER CENTRAL AND NORTHERN NJ AND WESTERN
LONG ISLAND.
THE OVERALL LONGWAVE PATTERN EVOLUTION WILL KEEP THE POTENTIAL OF
SHOWERS SOMEWHERE IN CENTRAL PA EACH DAY FROM FRIDAY ONWARD. WHILE
NO THREAT OF HEAVY RAINFALL IS SEEN AT THIS TIME...IT DOES NOT
APPEAR THAT DRIER CONDITIONS WILL RETURN UNTIL THE END OF THIS
PERIOD OF SHORTLY THEREAFTER.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
26/12Z...IN ADVANCE OF SFC COLD FRONT PUSHING SLOWLY SEWD ACRS
THE MIDWEST...COMBINATION OF STRONG MSTR TRANSPORT VIA SWLY LLJ
AND BROAD VERTICAL LIFT ASSOC WITH MID-UPPER TROUGH MOVG EWD ACRS
SERN CANADA WILL SUPPORT NMRS RAIN/SHOWERS ACROSS CENTRAL PA
THROUGH TONIGHT. THE FRONTAL ZONE WILL SHIFT SLOWLY SEWD ACRS THE
AREA THRU EARLY THURS MORNING BEFORE STALLING OUT NEAR THE PA/MD
BORDER INTO FRIDAY. CURRENT RADAR SHOWS BAND OF RAIN MOVG NEWD
THRU CENTRAL PA...IMPACTING LNS/MDT/UNV/BFD BTWN 12-13Z AND IPT
BTWN 13-15Z. FQNT SHOWERS ARE EXPECTED THROUGH THE AFTN...WITH AN
ISOLD TSTM PSBL MAINLY OVR THE SRN TERMINALS. IFR CIGS SHOULD
CONTINUE THRU THE MORNING HOURS AT BFD. SSW WIND AT JST FAVORS
MVFR OVER IFR..BUT WILL KEEP IFR THRU 15Z. ELSEWHERE...EXPECT MVFR
TO VFR CONDS TO PREVAIL.
OUTLOOK...
THU...VFR NORTH/MVFR SOUTH. SHOWERS LKLY SRN AIRFIELDS.
FRI-SUN...VFR TO MVFR WITH SCT SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...DANGELO/STEINBUGL
LONG TERM...DEVOIR/LA CORTE/GARTNER
AVIATION...DANGELO/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
750 AM EDT WED SEP 26 2012
.SYNOPSIS...
PERIODS OF RAIN CAN BE EXPECTED TODAY ACROSS MUCH OF CENTRAL
PENNSYLVANIA...IN ADVANCE OF A FRONTAL BOUNDARY PUSHING SLOWLY
SOUTHEAST THROUGH THE LOWER GREAT LAKES AND OHIO VALLEY. THE
FRONT WILL STALL OUT NEAR THE MASON DIXON LINE THURSDAY AND
FRIDAY...WITH THE THREAT OF RAIN PERSISTING MAINLY OVER THE
SOUTHERN THIRD OF THE KEYSTONE STATE. A DEEP UPPER LEVEL TROUGH
IS FORECAST TO DROP SOUTHWARD FROM EASTERN CANADA AND CARVE OUT
OVER THE GREAT LAKES REGION AND NORTHEAST STATES THIS WEEKEND.
&&
.NEAR TERM /UNTIL NOON TODAY/...
S/W EVIDENT OVR SERN OH/NRN WV PER RADAR/SATL IMAGERY IS COMBINING
WITH 40-50KT WSWLY LLJ /ILM VWP/ AND AXIS OF HI PWATS TO PRODUCE
AN AREA OF SHOWERS WITH EMBEDDED ELEVATED THUNDER FROM THE LAUREL
HIGHLANDS NWWD TO CLEVELAND. THE LATEST HRRR TAKES THE BULK OF THE
SHOWERS ACRS THE S-CENTRAL MTNS BTWN 09-12Z...WEAKENING WITH EWD
EXTENT AS THEY MOVE AWAY FROM THE NOSE OF LLJ AND REACH THE LWR
SUSQ VLY BY DAYBREAK. FURTHER NORTH TO THE I-80 CORRIDOR..EXPECT
CVRG OF SHOWERS TO BE MORE SCT IN NATURE WITH THE BEST CHC FOR
RAIN EARLY THIS MORNING WEST OF A LINE FROM UNV-BFD.
THERE SHOULD BE SOMEWHAT OF A BREAK IN THE PCPN THRU MID
MORNING...BUT THERE WILL STILL BE SOME SHOWERS AROUND THE AREA.
THE NEXT WAVE APPEARS TO BE MOVG THRU CVG ATTM AND WILL LKLY BE
THE CATALYST FOR THE NEXT ROUND OF SHOWERS ACRS WRN PA BY EARLY
AFTN.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM THURSDAY/...
ALTHOUGH THE MDLS SOLUTIONS DISAGREE ON THE FINER QPF DETAILS OF
THE FCST EVEN AT 6 HRLY TIME STEPS...THEY ARE OTHERWISE IN PRETTY
GOOD AGREEMENT ON A RNFL AXIS SETTING UP ALONG DEEP MSTR AXIS
STRADDLING THE OH RVR AND EXTENDING ENEWD ACRS SW/S-CENTRAL PA.
WAA/ISENT LIFT VIA STG WSWLY LLJ ALONG WITH ENHANCED LG SCALE LIFT
NEAR RIGHT ENT REGION OF UPPER JET WILL SUPPORT PERIODS OF RAIN
INTO TONIGHT. CLOUD COVER SHOULD LIMIT INSTABILITY BUT A FEW ISOLD
TSTMS CANNOT BE RULED OUT...ESPECIALLY OVR SRN PA WHERE SREF SHOWS
THE GREATEST POTENTIAL FOR DESTABILIZATION. MOD/HVY RNFL AXIS FROM
THE OH VLY SHOULD STRETCH INTO SW PA/LAURELS WITH D1 24HR QPF
AMTS NEAR 1 INCH IN THE JST/AOO AREA. FOLLOWED BLEND MORE IN-LINE
WITH ECMWF/CANADIAN/UKMET AS GFS DOES NOT APPEAR TO HAVE A GOOD
HANDLE ON CURRENT EVOLUTION OF PCPN.
THE MAIN SYNOPTIC COLD FRONT WILL PRESS SEWD LATE TONIGHT AND
EVENTUALLY STALL OUT NEAR THE PA/MD BORDER INTO THURS. NLY LLVL
FLOW WILL ADVECT A MUCH DRIER AIRMASS INTO THE NRN PART OF THE CWA
TONIGHT...WHICH SHOULD ENSURE A DRY OVERNIGHT PERIOD.
HOWEVER...SRN PA WILL LKLY CONT TO HAVE SHOWERS AS MSTR AXIS
REMAINS IN PLACE ALONG STALLED E-W FRONTAL ZONE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER TROF OVER SOUTHEAST CANADA AND THE NORTHEASTERN UNITED
STATES WILL LIFT OUT THURSDAY NIGHT AND FRIDAY IN FAVOR OF A
STRONGER UPPER TROF DIGGING SHARPLY SOUTHWARD THROUGH ONTARIO AND
CUTTING OFF OVER THE CENTRAL AND EASTERN GREAT LAKES LATE SATURDAY
AND SUNDAY. THIS WILL BRING SHORTLIVED IMPROVING CONDITIONS TO THE
REGION ON THURSDAY BEFORE INCREASINGLY UNSETTLED CONDITIONS RETURN
FOR LATER SATURDAY AND SUNDAY OVER CENTRAL PA.
GFS AND ECMWF ARE SIMILAR IN OVERALL SYNOPTIC EVOLUTION LATE THIS
WEEK AND THIS WEEKEND...WITH THE GFS DECIDEDLY FAVORING QPF
FARTHER TO THE EAST AS THE UPPER LOW CUTS OFF OVER THE CENTRAL AND
EASTERN GLAKS. ECMWF APPEARS MORE REALISTIC IN ITS DEPICTION OF
SCT TO NMRS SHOWERS IN THIS REGIME. SUBTROPICAL MOISTURE PLUME IS
DISPLACED WELL TO THE EAST OF OF THE MID ATLANTIC COAST AND IT
APPEARS WILL HAVE LITTLE INTERACTION WITH THE SAT-SUN CUTOFF AND
RESULTANT PRECIPITATION ACROSS THE REGION...SO HEAVY RAIN THREAT
IS FAIRLY LOW. GFS ENSEMBLE IS EVIDENCE OF THIS...WITH 24 HOUR
PROBABILITIES OF GREATER THAN 1 INCH IN THE SAT-SUN TIMEFRAME ONLY
TOPPING OUT AT 30 PERCENT OVER CENTRAL AND NORTHERN NJ AND WESTERN
LONG ISLAND.
THE OVERALL LONGWAVE PATTERN EVOLUTION WILL KEEP THE POTENTIAL OF
SHOWERS SOMEWHERE IN CENTRAL PA EACH DAY FROM FRIDAY ONWARD. WHILE
NO THREAT OF HEAVY RAINFALL IS SEEN AT THIS TIME...IT DOES NOT
APPEAR THAT DRIER CONDITIONS WILL RETURN UNTIL THE END OF THIS
PERIOD OF SHORTLY THEREAFTER.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
26/12Z...IN ADVANCE OF SFC COLD FRONT PUSHING SLOWLY SEWD ACRS
THE MIDWEST...COMBINATION OF STRONG MSTR TRANSPORT VIA SWLY LLJ
AND BROAD VERTICAL LIFT ASSOC WITH MID-UPPER TROUGH MOVG EWD ACRS
SERN CANADA WILL SUPPORT NMRS RAIN/SHOWERS ACROSS CENTRAL PA
THROUGH TONIGHT. THE FRONTAL ZONE WILL SHIFT SLOWLY SEWD ACRS THE
AREA THRU EARLY THURS MORNING BEFORE STALLING OUT NEAR THE PA/MD
BORDER INTO FRIDAY. CURRENT RADAR SHOWS BAND OF RAIN MOVG NEWD
THRU CENTRAL PA...IMPACTING LNS/MDT/UNV/BFD BTWN 12-13Z AND IPT
BTWN 13-15Z. FQNT SHOWERS ARE EXPECTED THROUGH THE AFTN...WITH AN
ISOLD TSTM PSBL MAINLY OVR THE SRN TERMINALS. IFR CIGS SHOULD
CONTINUE THRU THE MORNING HOURS AT BFD. SSW WIND AT JST FAVORS
MVFR OVER IFR..BUT WILL KEEP IFR THRU 15Z. ELSEWHERE...EXPECT MVFR
TO VFR CONDS TO PREVAIL.
OUTLOOK...
THU...VFR NORTH/MVFR SOUTH. SHOWERS LKLY SRN AIRFIELDS.
FRI-SUN...VFR TO MVFR WITH SCT SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DEVOIR/LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
605 AM EDT WED SEP 26 2012
.SYNOPSIS...
PERIODS OF RAIN CAN BE EXPECTED TODAY ACROSS MUCH OF CENTRAL
PENNSYLVANIA...IN ADVANCE OF A FRONTAL BOUNDARY PUSHING SLOWLY
SOUTHEAST THROUGH THE LOWER GREAT LAKES AND OHIO VALLEY. THE
FRONT WILL STALL OUT NEAR THE MASON DIXON LINE THURSDAY AND
FRIDAY...WITH THE THREAT OF RAIN PERSISTING MAINLY OVER THE
SOUTHERN THIRD OF THE KEYSTONE STATE. A DEEP UPPER LEVEL TROUGH
IS FORECAST TO DROP SOUTHWARD FROM EASTERN CANADA AND CARVE OUT
OVER THE GREAT LAKES REGION AND NORTHEAST STATES THIS WEEKEND.
&&
.NEAR TERM /UNTIL NOON TODAY/...
S/W EVIDENT OVR SERN OH/NRN WV PER RADAR/SATL IMAGERY IS COMBINING
WITH 40-50KT WSWLY LLJ /ILM VWP/ AND AXIS OF HI PWATS TO PRODUCE
AN AREA OF SHOWERS WITH EMBEDDED ELEVATED THUNDER FROM THE LAUREL
HIGHLANDS NWWD TO CLEVELAND. THE LATEST HRRR TAKES THE BULK OF THE
SHOWERS ACRS THE S-CENTRAL MTNS BTWN 09-12Z...WEAKENING WITH EWD
EXTENT AS THEY MOVE AWAY FROM THE NOSE OF LLJ AND REACH THE LWR
SUSQ VLY BY DAYBREAK. FURTHER NORTH TO THE I-80 CORRIDOR..EXPECT
CVRG OF SHOWERS TO BE MORE SCT IN NATURE WITH THE BEST CHC FOR
RAIN EARLY THIS MORNING WEST OF A LINE FROM UNV-BFD.
THERE SHOULD BE SOMEWHAT OF A BREAK IN THE PCPN THRU MID
MORNING...BUT THERE WILL STILL BE SOME SHOWERS AROUND THE AREA.
THE NEXT WAVE APPEARS TO BE MOVG THRU CVG ATTM AND WILL LKLY BE
THE CATALYST FOR THE NEXT ROUND OF SHOWERS ACRS WRN PA BY EARLY
AFTN.
&&
.SHORT TERM /NOON TODAY THROUGH 6 AM THURSDAY/...
ALTHOUGH THE MDLS SOLUTIONS DISAGREE ON THE FINER QPF DETAILS OF
THE FCST EVEN AT 6 HRLY TIME STEPS...THEY ARE OTHERWISE IN PRETTY
GOOD AGREEMENT ON A RNFL AXIS SETTING UP ALONG DEEP MSTR AXIS
STRADDLING THE OH RVR AND EXTENDING ENEWD ACRS SW/S-CENTRAL PA.
WAA/ISENT LIFT VIA STG WSWLY LLJ ALONG WITH ENHANCED LG SCALE LIFT
NEAR RIGHT ENT REGION OF UPPER JET WILL SUPPORT PERIODS OF RAIN
INTO TONIGHT. CLOUD COVER SHOULD LIMIT INSTABILITY BUT A FEW ISOLD
TSTMS CANNOT BE RULED OUT...ESPECIALLY OVR SRN PA WHERE SREF SHOWS
THE GREATEST POTENTIAL FOR DESTABILIZATION. MOD/HVY RNFL AXIS FROM
THE OH VLY SHOULD STRETCH INTO SW PA/LAURELS WITH D1 24HR QPF
AMTS NEAR 1 INCH IN THE JST/AOO AREA. FOLLOWED BLEND MORE IN-LINE
WITH ECMWF/CANADIAN/UKMET AS GFS DOES NOT APPEAR TO HAVE A GOOD
HANDLE ON CURRENT EVOLUTION OF PCPN.
THE MAIN SYNOPTIC COLD FRONT WILL PRESS SEWD LATE TONIGHT AND
EVENTUALLY STALL OUT NEAR THE PA/MD BORDER INTO THURS. NLY LLVL
FLOW WILL ADVECT A MUCH DRIER AIRMASS INTO THE NRN PART OF THE CWA
TONIGHT...WHICH SHOULD ENSURE A DRY OVERNIGHT PERIOD.
HOWEVER...SRN PA WILL LKLY CONT TO HAVE SHOWERS AS MSTR AXIS
REMAINS IN PLACE ALONG STALLED E-W FRONTAL ZONE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER TROF OVER SOUTHEAST CANADA AND THE NORTHEASTERN UNITED
STATES WILL LIFT OUT THURSDAY NIGHT AND FRIDAY IN FAVOR OF A
STRONGER UPPER TROF DIGGING SHARPLY SOUTHWARD THROUGH ONTARIO AND
CUTTING OFF OVER THE CENTRAL AND EASTERN GREAT LAKES LATE SATURDAY
AND SUNDAY. THIS WILL BRING SHORTLIVED IMPROVING CONDITIONS TO THE
REGION ON THURSDAY BEFORE INCREASINGLY UNSETTLED CONDITIONS RETURN
FOR LATER SATURDAY AND SUNDAY OVER CENTRAL PA.
GFS AND ECMWF ARE SIMILAR IN OVERALL SYNOPTIC EVOLUTION LATE THIS
WEEK AND THIS WEEKEND...WITH THE GFS DECIDEDLY FAVORING QPF
FARTHER TO THE EAST AS THE UPPER LOW CUTS OFF OVER THE CENTRAL AND
EASTERN GLAKS. ECMWF APPEARS MORE REALISTIC IN ITS DEPICTION OF
SCT TO NMRS SHOWERS IN THIS REGIME. SUBTROPICAL MOISTURE PLUME IS
DISPLACED WELL TO THE EAST OF OF THE MID ATLANTIC COAST AND IT
APPEARS WILL HAVE LITTLE INTERACTION WITH THE SAT-SUN CUTOFF AND
RESULTANT PRECIPITATION ACROSS THE REGION...SO HEAVY RAIN THREAT
IS FAIRLY LOW. GFS ENSEMBLE IS EVIDENCE OF THIS...WITH 24 HOUR
PROBABILITIES OF GREATER THAN 1 INCH IN THE SAT-SUN TIMEFRAME ONLY
TOPPING OUT AT 30 PERCENT OVER CENTRAL AND NORTHERN NJ AND WESTERN
LONG ISLAND.
THE OVERALL LONGWAVE PATTERN EVOLUTION WILL KEEP THE POTENTIAL OF
SHOWERS SOMEWHERE IN CENTRAL PA EACH DAY FROM FRIDAY ONWARD. WHILE
NO THREAT OF HEAVY RAINFALL IS SEEN AT THIS TIME...IT DOES NOT
APPEAR THAT DRIER CONDITIONS WILL RETURN UNTIL THE END OF THIS
PERIOD OF SHORTLY THEREAFTER.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
26/09Z UPDATE...MADE ONLY MINOR CHANGES TO 06Z TAFS TO ACCOUNT
FOR OCNL TS EMBEDDED WITHIN LGT/MOD RA MOVG THRU JST/AOO
TERMINALS. THIS AREA OF PCPN SHOULD REACH THE MDT/LNS AREA BTWN
11-12Z. NRN TERMINALS SHOULD STAY DRY THRU 11Z BEFORE BAND OF
SHOWERS NEAR BFD-UNV LINE BTWN 12-13Z. IPT SHOULD REMAIN DRY THRU
12Z. LOW IFR CIGS WILL PERSIST AT BFD WITH LOWER END MVFR AT JST.
AOO/UNV/IPT WILL STAY MVFR WITH MAINLY VFR AT MDT/LNS.
26/06Z...
IN ADVANCE OF A SFC FRONTAL BOUNDARY PUSHING SLOWLY SEWD ACRS THE
GRT LKS INTO THE OH VLY...COMBINATION OF STRONG MSTR TRANSPORT VIA
SWLY LLJ AND BROAD LIFT ASSOC WITH MID-UPPER TROUGH MOVG EWD ACRS
SERN CANADA WILL SUPPORT PERIODS OF RAIN ACROSS CENTRAL PA THROUGH
TONIGHT. MODEL DATA INDICATES HIGHEST PROBABILITY/GREATEST
COVERAGE OF RAIN ALONG A CORRIDOR FROM EITHER SIDE OF THE OH RVR
ENEWD ACRS S-CENTRAL PA INTO THE NRN MID-ATLC STATES...WITH THE
HEAVIEST SHOWERS/ISOLD TSTMS LOCATED FROM SRN OH INTO SW PA. THE
FRONTAL ZONE WILL SHIFT SLOWLY SEWD ACRS THE AREA LATER TODAY INTO
TONIGHT...SHIFTING WINDS FROM SSW TO WNW BEFORE STALLING OUT NEAR
THE PA/MD BORDER THURSDAY AND FRIDAY. 06Z OBS SHOW AREA OF LOW
IFR CIGS CONFINED THE NW PA WHICH SHOULD PERSIST AT LEAST THROUGH
THE MORNING HOURS. FURTHER TO THE SOUTH AND EAST...MVFR TO VFR
CONDS WILL PREVAIL ACRS THE CENTRAL AND SRN AIRFIELDS THROUGH THE
PERIOD. NOSE OF 30-40KT WSW LLJ WILL PRODUCE MARGINAL LLWS AT
JST/AOO/UNV IN THE 30-35KT RANGE THRU MID MORNING.
OUTLOOK...
THU...VFR NORTH/MVFR SOUTH. SHOWERS LKLY SRN AIRFIELDS.
FRI-SUN...VFR TO MVFR WITH SCT SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DEVOIR/LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
951 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT OVER THE OHIO VALLEY MOVES EAST TODAY AND TONIGHT AND
STALLS FROM THE MID ATLANTIC TO THE CENTRAL PLAINS ON THURSDAY.
THIS FRONT WILL GRADUALLY DRIFT INTO THE SOUTHEAST UNITED STATES ON
SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM EDT WEDNESDAY...
A FRONTAL BOUNDARY EXTENDED FROM LOWER MICHIGAN SOUTHWEST INTO
NORTHERN MISSOURI. THIS FEATURE WILL SLOW MOVE SOUTH TODAY. WAVES
OF ENERGY WILL BE RIDING ALONG THIS BOUNDARY...AND BRINGING ROUNDS
OF SHOWERS AND STORMS TO THE OHIO VALLEY. ISOLATED SHOWERS AND
STORMS OF THE SOUTHERN PERIPHERY OF THIS ACTIVITY IS EXPECTED TO
BRUSH THE FAR NORTHWESTERN EXTENT OF THE FORECAST AREA. THE
GREATEST EXTENT OF THE ISOLATED COVERAGE WILL LATE THIS
AFTERNOON...AND ALONG AND NORTH OF A MATOKA WV TO A GOSHEN VA
LINE.
OUR EARLIER FORECAST HAS BEEN ADJUSTED TO DEPICT A SLIGHTLY SLOWER
PROGRESSION OF THE SHOWERS AND STORMS INTO OUR REGION. OTHER THAN
THAT...HAVE MAKE TWEAKS IN THE TEMPERATURE...DEW
POINT...WIND...AND SKY COVER TO DEPICT THE LATEST OBSERVATIONS AND
EXPECTED TRENDS INTO THE EARLY AFTERNOON.
AS OF 420 AM EDT WEDNESDAY...
UPPER TROF WILL DIG INTO THE GREAT LAKES TODAY THEN MOVE EAST. 500
MB PATTERN OVER THE MID ATLANTIC REGION REMAINS ZONAL. FORECAST
AREA WELL WITHIN THE WARM SECTOR AHEAD OF A COLD FRONT THAT
EXTENDED FROM ONTARIO INTO NORTHERN MISSOURI. THE FRONT WILL MOVE
MUCH FASTER EAST THAN SOUTH AND SHOULD TRAIL FROM THE NEW ENGLAND
STATES INTO THE CENTRAL PLAINS BY THIS EVENING. BY THURSDAY
MORNING THE FRONT WILL BE OVER THE FORECAST AREAS BUT PARALLEL TO
THE UPPER FLOW SO EXPECTING LITTLE CHANGE IN THE SURFACE PATTERN FOR
THURSDAY.
CLUSTERS OF SHOWERS AND THUNDERSTORMS LINED UP ALONG THE FRONT AT
4AM. AS THE FRONT GETS CLOSER TO THE COUNTY WARNING AREA SO WILL
THE PRECIPITATION. SREF...LATEST RUC AND LOCAL WRF ALL BRING THE
PROBABILITY OF PRECIPITATION INTO THE NORTHWEST COUNTIES OF THE
FORECAST AREA THIS AFTERNOON. MOST LOCATIONS WILL HAVE ENOUGH
HEATING THIS MORNING TO HAVE ENOUGH INSTABILITY TO SUPPORT
THUNDERSTORMS THIS AFTERNOON.
HAVE TRIMMED HIGHS FOR TODAY ACROSS BATH AND GREENBRIER COUNTIES
WHERE THE CLOUDS WILL MOVE IN THE SOONEST. LOWS TONIGHT WILL
REMAIN MILD WITH ENOUGH MIXING AND CLOUDS TO HOLD UP MINIMUM
TEMPERATURES. STAYED WITH WARMER GUIDANCE FOR LOWS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
A QUASI-STATIONARY COLD FRONT WILL BEGIN TO DRIFT TO THE SOUTH
THURSDAY INTO FRIDAY. THIS FRONT WILL THEN STALL ON THE WESTERN SIDE
OF THE APPALACHIANS FRIDAY NIGHT. ONE REASON THIS FRONT IS SLOW TO
MOVE IS BECAUSE OF ZONAL FLOW ALOFT. ALSO TRAPPED IN THIS ZONAL FLOW
IS A WEAK RIDGE OF HIGH PRESSURE. THIS RIDGE WILL TRACK FROM THE
GREAT LAKES INTO NORTHEASTERN USA BY THURSDAY NIGHT. MODELS
INDICATING THIS RIDGE WILL WEDGE DOWN THE MID ATLANTIC THURSDAY
NIGHT. THIS WEDGE LOOKS SHALLOW AND SHOULD RETREAT TO THE NORTH
FRIDAY AFTERNOON IF LITTLE RAIN FALLS INTO IT.
WITH ZONAL FLOW...WE WILL NEED TO KEEP AN EYE ON THE MID WEST TO SEE
IF ANY STRONG COMPLEXES DRIFT OUR WAY...AS IN THE CASE YESTERDAY.
FOR NOW...MODELS ONLY BRING WEAK WAVES OVER THE AREA. RAIN CHANCES
WILL ALSO GET A BOOST FROM ISENTROPIC LIFT FRIDAY AND FRIDAY NIGHT.
THE BEST ISENTROPIC LIFT AND HEAVIER RAIN SHOULD REMAIN NORTH OF THE
AREA AND ALONG THE MASON-DIXON LINE. THE POTENTIAL FOR SEVERE
WEATHER IS LOW UNLESS A MESOSCALE COMPLEX SURVIVES THE TRIP FROM THE
MID WEST. THE WAY THINGS ARE LOOKING NOW...ONLY ELEVATED THUNDER
FROM SCATTERED STORMS ARE EXPECTED.
TEMPERATURES WILL REMAIN ABOVE NORMAL AS ALONG AS THE FRONT STAYS TO
OUR NORTH AND WEST. IF SHOWERS ARE SCATTERED OVER THE
REGION...ENOUGH ISOLATION SHOULD PEAK TEMPERATURES IN THE MID TO
UPPER 80S IN THE EAST. ACROSS THE MOUNTAINS...UPPER 70S TO LOWER 80S
EXPECTED THURSDAY. SIMILAR TEMPERATURES CAN BE ACHIEVED FRIDAY IF
THE RAIN HOLDS OFF. WITH RAIN EXPECTED...NEAR 80F IN THE EAST TO
LOWER TO MIDDLE 70S WEST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 245 PM EDT TUESDAY...
FRONTAL BOUNDARY IS GOING TO PLAY HAVOC WITH OUR WEATHER AND THE
FORECAST IN GENERAL THIS PERIOD. THE FRONT WORKS INTO THE AREA EARLY
IN THE PERIOD...THEN AS UPPER LOW OVER SRN ONTARIO DEEPENS INTO THE
GREAT LAKES OVER THE WEEKEND...IT SHOULD BE PUSHING THE FRONT
FURTHER SOUTH...WHILE SFC HIGH BUILDS INTO THE MID ATLANTIC.
HOWEVER..THE SW FLOW ALOFT GIVEN UPPER LOW/TROUGH BEING JUST WEST OF
US MAY HANG THE FRONT ACROSS THE CAROLINAS INTO ERN VA...WHILE WAVES
OF LOW PRESSURE MOVE ALONG IT KEEPING CLOUDS AND THREAT OF SHOWERS
AROUND. THIS WILL IMPACT TEMPS AND DECIDED TO GO CLOSER TO THE ECMWF
MOS. EARLY NEXT WEEK MODELS DIVERGE WITH BOTH AGREEING ON THE NRN
STREAM LOW LIFTING NEWD BUT SHOWING DIFFERENCES ON THE SRN STREAM.
THE GFS IS SHOWING SHARPER TROUGH MONDAY WHICH COULD SHIFT DEEPER
MOISTURE EAST...ALTHOUGH THE GFS/ECMWF DO SHOWING ANOTHER TROUGH
DEVELOPING ACROSS THE LOWER MISSISSIPPI VALLEY MONDAY...BUT WITH
UPSTREAM DIFFERENCES...THE ECMWF SHOWS MORE SOUTHERLY FLOW ALOFT
WHILE THE GFS BREAKS OFF AN UPPER HIGH INTO THE OHIO VALLEY
DEPICTING MORE NW FLOW ALOFT. ECMWF HAS BEEN DOING A BETTER JOB
OVERALL...AND HPC LINGERS THE FRONT AROUND THE EASTERN CAROLINAS
MON-TUE WITH CHANCES FOR PRECIP REMAINING. WEDGE MAY DEVELOP AS SFC
HIGH BUILDS SWD FROM THE MID ATLANTIC BY TUESDAY WITH EASTERLY FLOW
KEEPING MORE CLOUDS AROUND.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 740 AM EDT WEDNESDAY...
EXPECT PATCHY FOG AT BCB TO DISSIPATE BY 14Z/10AM. CLOUDS WILL
CONTINUE TO SPREAD BACK INTO THE AREA FROM THE WEST THIS MORNING.
PROBABILITY OF PRECIPITATION THROUGH 00Z/8PM TONIGHT IS NOT HIGH
ENOUGH TO INCLUDE IN THE TAFS AT THIS TIME. BEST CHANCE REMAINS
WEST AND NORTH OF LWB.
AS A COLD FRONT APPROACHES THE REGION TONIGHT THE CHANCE OF
PRECIPITATION WITH MVFR CEILINGS AND VISIBILITIES INCREASES AT
LWB AND BLF.
MVFR CONDITIONS ARE EXPECTED TO BECOME MORE WIDESPREAD ON THURSDAY
AND PERSIST INTO SATURDAY AS A COLD FRONT STALLS ACROSS THE AREA.
HIGH CONFIDENCE OF OCCASIONAL SHOWERS AND THUNDERSTORMS. ALSO PATCHY
MORNING FOG MAY DEVELOP DURING THE PREDAWN HOURS AT LWB/BCB...AND
AT ANY SITES THAT GET PRECIPITATION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/DS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...WP
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
748 AM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT OVER THE OHIO VALLEY MOVES EAST TODAY AND TONIGHT AND
STALLS FROM THE MID ATLANTIC TO THE CENTRAL PLAINS ON THURSDAY.
THIS FROM WILL GRADUALLY DRIFT INTO THE SOUTHEAST UNITED STATES ON
SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 420 AM EDT WEDNESDAY...
UPPER TROF WILL DIG INTO THE GREAT LAKES TODAY THEN MOVE EAST. 500
MB PATTERN OVER THE MID ATLANTIC REGION REMAINS ZONAL. FORECAST
AREA WELL WITHIN THE WARM SECTOR AHEAD OF A COLD FRONT THAT
EXTENDED FROM ONTARIO INTO NORTHERN MISSOURI. THE FRONT WILL MOVE
MUCH FASTER EAST THAN SOUTH AND SHOULD TRAIL FROM THE NEW ENGLAND
STATES INTO THE CENTRAL PLAINS BY THIS EVENING. BY THURSDAY
MORNING THE FRONT WILL BE OVER THE FORECAST AREAS BUT PARALLEL TO
THE UPPER FLOW SO EXPECTING LITTLE CHANGE IN THE SURFACE PATTERN FOR
THURSDAY.
CLUSTERS OF SHOWERS AND THUNDERSTORMS LINED UP ALONG THE FRONT AT
4AM. AS THE FRONT GETS CLOSER TO THE COUNTY WARNING AREA SO WILL
THE PRECIPITATION. SREF...LATEST RUC AND LOCAL WRF ALL BRING THE
PROBABILITY OF PRECIPITATION INTO THE NORTHWEST COUNTIES OF THE
FORECAST AREA THIS AFTERNOON. MOST LOCATIONS WILL HAVE ENOUGH
HEATING THIS MORNING TO HAVE ENOUGH INSTABILITY TO SUPPORT
THUNDERSTORMS THIS AFTERNOON.
HAVE TRIMMED HIGHS FOR TODAY ACROSS BATH AND GREENBRIER COUNTIES
WHERE THE CLOUDS WILL MOVE IN THE SOONEST. LOWS TONIGHT WILL
REMAIN MILD WITH ENOUGH MIXING AND CLOUDS TO HOLD UP MINIMUM
TEMPERATURES. STAYED WITH WARMER GUIDANCE FOR LOWS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
A QUASI-STATIONARY COLD FRONT WILL BEGIN TO DRIFT TO THE SOUTH
THURSDAY INTO FRIDAY. THIS FRONT WILL THEN STALL ON THE WESTERN SIDE
OF THE APPALACHIANS FRIDAY NIGHT. ONE REASON THIS FRONT IS SLOW TO
MOVE IS BECAUSE OF ZONAL FLOW ALOFT. ALSO TRAPPED IN THIS ZONAL FLOW
IS A WEAK RIDGE OF HIGH PRESSURE. THIS RIDGE WILL TRACK FROM THE
GREAT LAKES INTO NORTHEASTERN USA BY THURSDAY NIGHT. MODELS
INDICATING THIS RIDGE WILL WEDGE DOWN THE MID ATLANTIC THURSDAY
NIGHT. THIS WEDGE LOOKS SHALLOW AND SHOULD RETREAT TO THE NORTH
FRIDAY AFTERNOON IF LITTLE RAIN FALLS INTO IT.
WITH ZONAL FLOW...WE WILL NEED TO KEEP AN EYE ON THE MID WEST TO SEE
IF ANY STRONG COMPLEXES DRIFT OUR WAY...AS IN THE CASE YESTERDAY.
FOR NOW...MODELS ONLY BRING WEAK WAVES OVER THE AREA. RAIN CHANCES
WILL ALSO GET A BOOST FROM ISENTROPIC LIFT FRIDAY AND FRIDAY NIGHT.
THE BEST ISENTROPIC LIFT AND HEAVIER RAIN SHOULD REMAIN NORTH OF THE
AREA AND ALONG THE MASON-DIXON LINE. THE POTENTIAL FOR SEVERE
WEATHER IS LOW UNLESS A MESOSCALE COMPLEX SURVIVES THE TRIP FROM THE
MID WEST. THE WAY THINGS ARE LOOKING NOW...ONLY ELEVATED THUNDER
FROM SCATTERED STORMS ARE EXPECTED.
TEMPERATURES WILL REMAIN ABOVE NORMAL AS ALONG AS THE FRONT STAYS TO
OUR NORTH AND WEST. IF SHOWERS ARE SCATTERED OVER THE
REGION...ENOUGH ISOLATION SHOULD PEAK TEMPERATURES IN THE MID TO
UPPER 80S IN THE EAST. ACROSS THE MOUNTAINS...UPPER 70S TO LOWER 80S
EXPECTED THURSDAY. SIMILAR TEMPERATURES CAN BE ACHIEVED FRIDAY IF
THE RAIN HOLDS OFF. WITH RAIN EXPECTED...NEAR 80F IN THE EAST TO
LOWER TO MIDDLE 70S WEST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 245 PM EDT TUESDAY...
FRONTAL BOUNDARY IS GOING TO PLAY HAVOC WITH OUR WEATHER AND THE
FORECAST IN GENERAL THIS PERIOD. THE FRONT WORKS INTO THE AREA EARLY
IN THE PERIOD...THEN AS UPPER LOW OVER SRN ONTARIO DEEPENS INTO THE
GREAT LAKES OVER THE WEEKEND...IT SHOULD BE PUSHING THE FRONT
FURTHER SOUTH...WHILE SFC HIGH BUILDS INTO THE MID ATLANTIC.
HOWEVER..THE SW FLOW ALOFT GIVEN UPPER LOW/TROUGH BEING JUST WEST OF
US MAY HANG THE FRONT ACROSS THE CAROLINAS INTO ERN VA...WHILE WAVES
OF LOW PRESSURE MOVE ALONG IT KEEPING CLOUDS AND THREAT OF SHOWERS
AROUND. THIS WILL IMPACT TEMPS AND DECIDED TO GO CLOSER TO THE ECMWF
MOS. EARLY NEXT WEEK MODELS DIVERGE WITH BOTH AGREEING ON THE NRN
STREAM LOW LIFTING NEWD BUT SHOWING DIFFERENCES ON THE SRN STREAM.
THE GFS IS SHOWING SHARPER TROUGH MONDAY WHICH COULD SHIFT DEEPER
MOISTURE EAST...ALTHOUGH THE GFS/ECMWF DO SHOWING ANOTHER TROUGH
DEVELOPING ACROSS THE LOWER MISSISSIPPI VALLEY MONDAY...BUT WITH
UPSTREAM DIFFERENCES...THE ECMWF SHOWS MORE SOUTHERLY FLOW ALOFT
WHILE THE GFS BREAKS OFF AN UPPER HIGH INTO THE OHIO VALLEY
DEPICTING MORE NW FLOW ALOFT. ECMWF HAS BEEN DOING A BETTER JOB
OVERALL...AND HPC LINGERS THE FRONT AROUND THE EASTERN CAROLINAS
MON-TUE WITH CHANCES FOR PRECIP REMAINING. WEDGE MAY DEVELOP AS SFC
HIGH BUILDS SWD FROM THE MID ATLANTIC BY TUESDAY WITH EASTERLY FLOW
KEEPING MORE CLOUDS AROUND.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 740 AM EDT WEDNESDAY...
EXPECT PATCHY FOG AT BCB TO DISSIPATE BY 14Z/10AM. CLOUDS WILL
CONTINUE TO SPREAD BACK INTO THE AREA FROM THE WEST THIS MORNING.
PROBABILITY OF PRECIPITATION THROUGH 00Z/8PM TONIGHT IS NOT HIGH
ENOUGH TO INCLUDE IN THE TAFS AT THIS TIME. BEST CHANCE REMAINS
WEST AND NORTH OF LWB.
AS A COLD FRONT APPROACHES THE REGION TONIGHT THE CHANCE OF
PRECIPITATION WITH MVFR CEILINGS AND VISIBILITIES INCREASES AT
LWB AND BLF.
MVFR CONDITIONS ARE EXPECTED TO BECOME MORE WIDESPREAD ON THURSDAY
AND PERSIST INTO SATURDAY AS A COLD FRONT STALLS ACROSS THE AREA.
HIGH CONFIDENCE OF OCCASIONAL SHOWERS AND THUNDERSTORMS. ALSO PATCHY
MORNING FOG MAY DEVELOP DURING THE PREDAWN HOURS AT LWB/BCB...AND
AT ANY SITES THAT GET PRECIPITATION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...WP
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
123 PM EDT WED SEP 26 2012
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND ACROSS THE REGION THROUGH FRIDAY. A COLD
FRONT IS EXPECTED TO APPROACH AND THEN LINGER NEAR THE AREA LATE
THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE BOTH AT THE SURFACE AND ALOFT WILL DOMINATE AGAIN
TODAY. THE LOW-LEVEL FLOW IS EXPECTED TO VEER MORE EASTERLY THIS
AFTERNOON IN RESPONSE TO SURFACE HIGH PRESSURE SHIFTING FARTHER
OUT INTO THE ATLANTIC. ALTHOUGH LOW-LEVEL MOISTURE WILL SLOWLY
INCREASE AS THE FLOW BECOMES MORE ONSHORE...26/13Z RAP SOUNDINGS
SUGGEST THE SUBCLOUD LAYER WILL REMAIN TOO DRY TO SUPPORT
MEASURABLE PRECIPITATION. STILL CAN NOT COMPLETELY RULE OUT A
SPRINKLE OR TWO ACROSS THE GEORGIA COASTAL COUNTIES...MAINLY ALONG
THE BEACHES FROM SAINT CATHERINES SOUND SOUTH TO THE ALTAMAHA
SOUND...BUT PROBABILITIES ARE TOO LOW TO JUSTIFY A MENTION AT THIS
TIME. EXPECT A MODEST CUMULUS FIELD TO DEVELOP AT THE COAST AND
SOUTH OF I-16 WITH MOSTLY SUNNY SKIES ELSEWHERE. HIGHS WILL RANGE
FROM THE MID 80S INLAND TO THE UPPER 70S/AROUND 80 AT THE BEACHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT...HIGH PRESSURE TO PERSIST TONIGHT WITH MAINLY CLEAR SKIES
IN PLACE. INCREASING LOW-LEVEL MOISTURE AND LIGHT WINDS WILL
PROMOTE FOG DEVELOPMENT...SOME OF WHICH COULD BECOME DENSE. LOWS
MAINLY IN THE LOWER TO MID 60S INLAND WITH LOWER 70S AT THE COAST.
THE FLOW ALOFT BECOMES MORE ZONAL THURSDAY THROUGH FRIDAY...AS THE
RIDGING TO THE SOUTH BEGINS TO WEAKEN AS SHORT WAVES PASS BY TO THE
NORTH. THIS PATTERN CAUSES SURFACE HIGH PRESSURE THAT IS INITIALLY
ATOP THE REGION EARLY THURSDAY TO WEAKEN...EVENTUALLY FORCING IT TO
WEAKEN ENOUGH FRIDAY WHERE THE CORE OF THE HIGH IS IN THE ATLANTIC
AND MERGING WITH HIGH PRESSURE MOVING OUT OF NEW ENGLAND. IN
RESPONSE THERE IS AN INCREASE IN SURFACE DEW POINTS AND COLUMNAR
MOISTURE AS A PERSISTENT EASTERLY SYNOPTIC FLOW SETS IN. ALTHOUGH
THERE IS SUFFICIENT INSTABILITY PRESENT WITH LIFTED INDICES NEAR
-3/-4 AND SBCAPES GREATER THAN 1000 J/KG...THERE IS LITTLE IN THE
WAY OF FORCING OUTSIDE OF THE SEA BREEZE. FOR THAT REASON WE WILL
SHOW NO MORE THAN 14 PERCENT POPS OVER LAND-BASED LOCATIONS. TEMPS
WILL MODERATE TO VALUES ABOVE SEASONAL NORMS...WITH AFTERNOON
MAXIMUM READINGS BOTH DAYS TO REACH THE MID-UPPER 80S MOST
LOCALES AWAY FROM THE SLIGHTLY COOLER COASTLINE. FOG WILL BE A
CONCERN THURSDAY MORNING AND AGAIN THURSDAY NIGHT INTO FRIDAY
MORNING WITH THE HIGHER DEW POINTS AND CONSIDERABLE DRY AIR IN THE
MID/UPPER LEVELS. WITH CONDENSATION PRESSURE DEFICITS LESS THAN 20
OR 30 MILLIBARS AND LIGHT WIND FIELDS IN THE PLANETARY BOUNDARY
LAYER WE WILL NEED TO MONITOR THE POTENTIAL FOR AT LEAST LOCALLY
DENSE FOG OCCURRING.
SATURDAY...THE RECENTLY FLAT FLOW ALOFT BECOMES MUCH MORE AMPLIFIED
AS A CLOSED LOW DEVELOPS OVER SE CANADA AND ITS ASSOCIATED SHORT
WAVE ENERGY DROPS SE THROUGH THE GREAT LAKES. THIS ESTABLISHES A
LARGE TROUGH OVER THE EASTERN STATES...WHILE AT THE SAME TIME
RIDGING FORMS OVER THE CENTRAL U.S. AND INTO SOUTH-CENTRAL CANADA. A
STRONG 100 KT OR GREATER JET PROGRESSES EASTWARD THROUGH THE BASE OF
THE EASTERN TROUGH AND PUSHES TOWARD THE MID ATLANTIC/SE STATES FOR
THE FIRST HALF OF THE WEEKEND. THIS IN TURN SENDS A COLD FRONT
TOWARD THE CENTRAL/SOUTHERN APPALACHIANS BY LATE IN THE DAY.
ADEQUATE MOISTURE/INSTABILITY...BETTER DYNAMIC FORCING ALOFT WITH
THE APPROACHING JET AND FALLING HEIGHTS SUPPORTS ISOLATED TO
SCATTERED SHOWERS/T-STORMS. COMPRESSIONAL HEATING IN ADVANCE OF THE
FRONT LOOKS TO BE ENOUGH TO OVERCOME AN INCREASE IN CLOUD COVER TO
BOOST TEMPS AS HIGH AS THE MID 80S AWAY FROM THE BEACHES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THE CLOSED LOW DROPS SOUTHWARD INTO THE OHIO VALLEY THE SECOND HALF
OF THE WEEKEND..WITH ITS ASSOCIATED LONG WAVE TROUGH TO DIG SOUTH TO
AT LEAST THE GULF COAST STATES...OR MAYBE EVEN INTO THE GULF OF
MEXICO. THIS IN TURN PUSHES THE COLD FRONT ACROSS THE APPALACHIANS
AS IT ATTEMPTS TO APPROACH THE FORECAST AREA SUNDAY. THE CLOSED LOW
THEN LIFTS OUT ON MONDAY...BUT IT LEAVES BEHIND A PIECE OF ENERGY
OVER THE LOWER MS VALLEY...WHICH THEN LOOKS TO CLOSE OFF BY MID
WEEK. UNCERTAINTY EXISTS IN THE FORECAST IN REGARDS TO THE
PROGRESSION OR LACK THEREOF FOR THE COLD FRONT. THE FRONT WILL
BECOME PARALLEL TO THE FLOW ALOFT...AND IT ALSO RUNS INTO A BUILDING
ATLANTIC SUB-TROPICAL RIDGE ALOFT. PLUS A SURFACE WAVE MAY FORM ON
THE FRONT IN THE GULF OF MEXICO...WHICH WOULD FURTHER SLOW THE
PROGRESSION OF THE FRONT. WE/LL KEEP THE FRONT IN CLOSE PROXIMITY TO
OUR AREA DURING THE EARLY AND MIDDLE PART OF NEXT WEEK...AND THUS A
GREATER CHANCE OF PRECIPITATION. WE PREFER TO KEEP THE RAIN CHANCE
NO HIGHER THAN 30-40 PERCENT...BUT THAT COULD CHANGE SIGNIFICANTLY
ONE WAY OR THE OTHER DEPENDING UPON THE FUTURE PROGRESSION OF THE
FRONT AND THE PATTERN ALOFT. TEMPS WILL HOLD NEAR OR SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
THE PRIMARY ISSUE FOR THE 18Z TAF CYCLE IS PINNING DOWN THE EXTENT
OF OVERNIGHT FOG/STRATUS. 12Z GUIDANCE HAS BEGUN TO BACK OFF
CONSIDERABLY ON THE POTENTIAL FOR FOG AND STRATUS LATE TONIGHT.
DEWPOINTS ARE EXPECTED TO REMAIN SOMEWHAT ELEVATED WITHIN A CALM
WIND REGIME AND THERE WILL BE CONSIDERABLE DRY AIR ALOFT...SO SOME
PARAMETERS ARE CERTAINLY FAVORABLE FOR FOG. ATTM IT APPEARS THE
GREATEST COVERAGE OF FOG/STRATUS WILL REMAIN WEST OF THE KCHS-KSAV
TERMINALS WITH KSAV LIKELY SEEING THE HIGHEST PROBABILITIES FOR
IMPACT. GIVEN MODELS ARE BEGINNING TO BACK OFF SOMEWHAT...DO NOT
SEE A NEED TO SHOW IFR CONDITIONS ATTM. PLAN TO KEEP KCHS VFR FOR
THE ENTIRE OVERNIGHT PERIOD WITH KSAV ONLY DROPPING TO MVFR FROM
08-12Z. THERE IS LOW CONFIDENCE IN THIS FORECAST AND THERE IS A
POSSIBILITY THAT THE TAFS WILL NEED TO BE TRENDED LOWER IN BOTH
VSBYS/CIGS WITH THE 00Z TAF CYCLE.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CONDITIONS POSSIBLE IN
FOG THURSDAY MORNING AND AGAIN LATE THURSDAY NIGHT/FRIDAY MORNING.
ISOLATED TO SCATTERED SHRA/TSRA SATURDAY INTO SUNDAY MAY
TEMPORARILY REDUCE VSBYS/CIGS TO SUB-VFR LEVELS.
&&
.MARINE...
TODAY AND TONIGHT...HIGH PRESSURE WILL PERSIST OVER OR JUST NORTH
OF THE AREA KEEPING A LIGHT-MODERATE NORTHEAST/EAST FLOW ACROSS
THE LOCAL WATERS. SEAS WILL BE ON A DOWNWARD TREND...WITH
SIGNIFICANT WAVE HEIGHTS PEAKING AT 5 FT THIS MORNING ACROSS THE
EASTERN EDGES OF THE OFFSHORE GEORGIA WATERS...OTHERWISE NO HIGHER
THAN 3 OR 4 FT ELSEWHERE TO OCCUR.
THURSDAY THROUGH SUNDAY...WEAK HIGH PRESSURE WILL PREVAIL ACROSS THE
WATERS INTO SATURDAY...WHICH GIVES WAY TO A COLD FRONT SUNDAY. WIND
AND SEA CONDITIONS ACROSS THE MARINE AREA DURING THIS TIME WILL
REMAIN RELATIVELY QUIET...WITH MOSTLY GENTLE OR MODERATE BREEZES
/WMO CLASSIFICATION/...AND SEAS 3 FEET OR LESS. MARINERS WILL
EXPERIENCE A FEW SHOWERS OR T-STORMS THROUGH THE WEEKEND...WITH THE
HIGHEST PROBABILITIES TO OCCUR LATE SUNDAY IN ADVANCE OF THE COLD
FRONT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...RJB
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS LINCOLN IL
221 PM CDT WED SEP 26 2012
.DISCUSSION...
ISSUED 221 PM CDT WED SEP 26 2012
RAIN CHANCES WILL PERSIST ACROSS SOUTH-CENTRAL ILLINOIS THROUGH
THURSDAY NIGHT...BEFORE A LONG STRETCH OF DRY WEATHER DEVELOPS
ACROSS THE ENTIRE REGION THROUGH NEXT WEEK.
SHORT TERM...TONIGHT THROUGH SATURDAY
19Z/2PM SURFACE ANALYSIS SHOWS A SLOW-MOVING COLD FRONT EXTENDING
FROM JUST SOUTH OF KIKK TO NEAR KUIN. TO THE NORTH OF THE
FRONT...WINDS HAVE BECOME NORTHERLY AND A DRIER AIRMASS IS
BEGINNING TO SETTLE INTO THE FAR NORTHERN KILX CWA. MEANWHILE
SOUTH OF THE BOUNDARY...A MOIST ENVIRONMENT CHARACTERIZED BY
DEWPOINTS IN THE 60S IS SUPPORTING SCATTERED SHOWERS/THUNDER
ACROSS THE REMAINDER OF THE AREA. COLD FRONT IS NOT EXPECTED TO
DROP MUCH FURTHER SOUTH TONIGHT...AS UPPER-LEVEL WAVE CURRENTLY
OVER EASTERN KANSAS WILL IMPEDE ITS SOUTHERN PROGRESS. AS A
RESULT...THINK FRONT WILL ONLY SINK TO JUST SOUTH OF THE I-72
CORRIDOR OVERNIGHT. AS A RESULT...WILL CONTINUE TO CARRY LOW
CHANCE POPS ACROSS THE CENTRAL ZONES...WITH HIGHEST POPS FOCUSED
ALONG/SOUTH OF I-70 WHERE DEEPEST MOISTURE AND STRONGEST LIFT WILL
BE PRESENT. WITH FRONT IN THE VICINITY AND DRIER AIRMASS ONLY
TRICKLING SLOWLY SOUTHWARD...THINK AREAS OF FOG WILL DEVELOP
OVERNIGHT. LAST NIGHT...FOG FORMED IN LOCATIONS NEAR/SOUTH OF THE
BOUNDARY WHERE DEWPOINTS HOVERED IN THE UPPER 50S/LOWER 60S. THOSE
CONDITIONS WILL LIKELY EXIST FURTHER SOUTH TONIGHT...PRIMARILY
ALONG/SOUTH OF I-70. NAM FORECAST SOUNDINGS PROVIDE A STRONG
SIGNAL FOR FOG AT BOTH KMTO AND KLWV AND HRRR VISBY PROGS SUPPORT
THIS AS WELL...SO HAVE INCLUDED AREAS OF FOG ACROSS THE SOUTHEAST
AFTER MIDNIGHT.
ANY FOG WILL GRADUALLY BURN OFF THURSDAY MORNING...HOWEVER SKIES
WILL REMAIN MOSTLY CLOUDY THROUGHOUT THE DAY ACROSS THE SOUTHEAST
AS THE FRONT MAKES ONLY VERY SLOW PROGRESS SOUTHWARD. WILL
CONTINUE WITH CHANCE POPS ALONG AND SOUTH OF A PARIS TO
SHELBYVILLE LINE...WITH DRY CONDITIONS EXPECTED FURTHER NORTH.
BOTH THE NAM AND GFS FINALLY GIVE THE BOUNDARY A GOOD PUSH
SOUTHWARD BY FRIDAY...AS HIGH PRESSURE BUILDS INTO THE UPPER
MIDWEST. WILL HOLD ON TO A SLIM CHANCE FOR A SHOWER SOUTH OF I-70
INTO FRIDAY IN CASE FRONT IS DELAYED...BUT WILL GO WITH MOSTLY
SUNNY AND DRY CONDITIONS ELSEWHERE.
WITH HIGH PRESSURE BEING THE DOMINANT WEATHER FEATURE...SUNNY
SKIES AND DRY WEATHER IS EXPECTED THIS WEEKEND. TEMPERATURES WILL
REMAIN NEAR NORMAL FOR THIS TIME OF YEAR...WITH DAYTIME HIGHS IN
THE LOWER TO MIDDLE 70S AND OVERNIGHT LOWS IN THE LOWER 50S.
LONG TERM...SUNDAY THROUGH WEDNESDAY
A VIGOROUS SHORT-WAVE WILL DIVE INTO THE GREAT LAKES LATE IN THE
WEEKEND...PUSHING A WEAK COLD FRONT/SURFACE TROUGH THROUGH CENTRAL
ILLINOIS SATURDAY NIGHT INTO SUNDAY. SYSTEM WILL HAVE VERY LITTLE
MOISTURE TO WORK WITH...SO AM ONLY EXPECTING A FEW CLOUDS AS IT
PASSES THROUGH. AFTER THAT...A MAJOR PATTERN CHANGE IS IN STORE
NEXT WEEK. BOTH THE GFS AND ECMWF ARE SHOWING AN UPPER-LEVEL RIDGE
BUILDING ACROSS THE PLAINS INTO THE MIDWEST BY THE MIDDLE AND END
OF THE WEEK. RISING HEIGHTS AND INCREASING SOUTHERLY FLOW WILL
BOOST TEMPS WELL INTO THE 70S BY MONDAY AND TUESDAY...THEN PERHAPS
INTO THE 80S AFTER THAT. BOTH MODELS INDICATE 850MB TEMPS IN THE
15 TO 17C RANGE BY NEXT WEDNESDAY...SUGGESTING A RETURN TO
SUMMER-LIKE WARMTH IN THE EXTENDED.
BARNES
&&
.AVIATION...
ISSUED 1249 PM CDT WED SEP 26 2012
MAIN CONCERN THIS TAF PERIOD WILL BE WITH CIGS AT THE START OF THE
PERIOD AND TIMING OF FRONTAL PASSAGE. A FRONTAL BOUNDARY REMAINS DRAPED
ACROSS CENTRAL ILLINOIS...WHERE A BAND OF SHOWERS AND ISOLATED
THUNDERSTORMS HAVE DEVELOPED AHEAD OF IT. MVFR CIGS HAVE ALSO
PERSISTED ALONG AND AHEAD OF THE BOUNDARY. THESE CIGS WILL LIKELY
HANG AROUND UNTIL THE BOUNDARY SINKS SOUTH LATER THIS AFTERNOON.
SPI/DEC/CMI HAVE THE BEST SHOT OF SEEING ANY PRECIPITATION
TODAY...SO HAVE DECIDED TO KEEP VCSH IN TAF AS PINNING DOWN TIMING FOR
SUCH SCATTERED ACTIVITY IS DIFFICULT. SOUTHERLY WINDS WILL TURN TO
THE NORTH/NORTHEAST ONCE FRONT PASSES THROUGH. SHOULD START TO SEE
SOME DRIER AIR ADVECT SOUTHWARD...SO THINKING THAT FOG SHOULD NOT BE
MUCH OF AN ISSUE TONIGHT. ALTHOUGH GIVEN PREVIOUS RAINFALL...COULD
SEE SOME POCKETS OF MVFR. WILL LEAVE OUT MENTION FOR NOW AND
CONTINUE TO MONITOR TRENDS.
ECT
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
332 PM EDT WED SEP 26 2012
.SHORT TERM.../TONIGHT THROUGH THURSDAY NIGHT/
COLD FRONT WAS LOCATED FROM ROUGHLY RENSSELAER TO WARSAW TO MONROE
MI. A FEW SHOWERS/STORMS WERE ATTEMPTING TO FORM ON THE FRONT.
HOWEVER...GREATER COVERAGE AND INTENSITY SHOWERS/STORMS WERE NOTED
ALONG AND SOUTH OF US 24 ALONG SEMI STATIONARY TROUGH THAT HAS BEEN
A FOCUS FOR DEVELOPMENT MUCH OF THE DAY. IN ADDITION...A WAVE WAS
MOVING ACROSS CENTRAL INDIANA GIVING EXTRA LIFT TO THE FEATURE.
GRIDS WERE UPDATED EARLIER TO REFLECT THESE TRENDS AND STILL LOOK
REASONABLE SO WILL RUN WITH PRE 1ST PERIOD WITH SOME TIMING OF
PRECIP HOPEFULLY OUT OF THE AREA BY 00Z. SOME CONCERNS THAT FAR SE
COUNTIES COULD SEE SOME LINGERING SHOWERS INTO THE 00-03Z TIME FRAME
BUT WILL LEAVE DRY FOR NOW AND LET EVE SHIFT MONITOR TRENDS.
FRONT AND DEEPER MSTR STILL LOOKS TO SETTLE FAR ENOUGH SOUTH OF THE
FORECAST AREA TO ALLOW FOR CLEARING ACROSS MOST LOCATIONS SAVE
SOUTHERN THIRD WHERE PARTLY CLOUDY SKIES MAY STICK AROUND GIVEN
PROXIMITY OF FRONT AND ADDITIONAL WAVES MOVING ALONG IT TO THROW AT
LEAST SOME CLOUD COVER NORTHWARD. MUCH DRIER AIR WILL FILTER IN WITH
DEWPTS DROPPING INTO THE 40S AND PARTLY TO MOSTLY SUNNY SKIES ON
THURSDAY ALLOWING FOR SEASONABLE TEMPS IN THE UPPER 60S TO AROUND
70.
&&
.LONG TERM...
GENERAL PATTN DEAMPLIFICATION XPCD THIS PD BEYOND THIS WEEKEND.
ACTIVE W-E FNTL ZONE INVOF THE OH RVR WILL SINK SWD IN RESPONSE TO
RETROGRADING COMING OUT OF WRN QB FRI NIGHT. HWVR CONTD DRY NRLY FLW
EQUATES TO LTL IF ANY SENSIBLE WX CONCERNS SANS DY4 SAT PENDING SWRN
EXTENT OF UPR LOW TRACK. WILL CONT W/DRY FCST AS MODEL TRACK
CONSENSUS REMAINS NE OF AREA W/LIMITED MSTR.
OTHERWISE TEMPS NR SEASONAL NORMS TO START THE PD W/GRADUAL
MODERATION TO MUCH ABV XPCD LT PD IN RESPONSE TO INCREASINGLY ZONAL
FLW.
&&
.AVIATION...
COLD FRONT HAS CLEARED KSBN WITH DRIER AIR AND CLEARING SKIES
SLOWLY ARRIVING. VFR CONDITIONS ANTICIPATED OVER NEXT COUPLE OF
HOURS. AT KFWA...FORECAST MORE CHALLENGING WITH FRONT STILL TO THE
NW AND AREA OF SHOWERS AND EMBEDDED STORMS SLOWLY WORKING N/NNE
OUT OF CNTRL INDIANA AND ILLINOIS. 13Z RUN OF HRRR HAD A GOOD
HANDLE ON CURRENT SETUP AND TRIES TO BRING THE AREA AS FAR NORTH
AS THE AIRPORT. HOWEVER WITH FRONT NOT TOO FAR AWAY HAVE DECIDED
TO HOLD OFF ON ADDING ANY SHOWER/STORM MENTION AND MONITOR TRENDS.
MVFR/IFR CONDITIONS WILL LIKELY PERSIST THROUGH AT LEAST LATER TONIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...RIP CURRENT RISK THROUGH LATE TONIGHT FOR INZ003.
MI...RIP CURRENT RISK THROUGH LATE TONIGHT FOR MIZ077.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...T
AVIATION...FISHER
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
150 PM EDT WED SEP 26 2012
.AVIATION...
COLD FRONT HAS CLEARED KSBN WITH DRIER AIR AND CLEARING SKIES
SLOWLY ARRIVING. VFR CONDITIONS ANTICIPATED OVER NEXT COUPLE OF
HOURS. AT KFWA...FORECAST MORE CHALLENGING WITH FRONT STILL TO THE
NW AND AREA OF SHOWERS AND EMBEDDED STORMS SLOWLY WORKING N/NNE
OUT OF CNTRL INDIANA AND ILLINOIS. 13Z RUN OF HRRR HAD A GOOD
HANDLE ON CURRENT SETUP AND TRIES TO BRING THE AREA AS FAR NORTH
AS THE AIRPORT. HOWEVER WITH FRONT NOT TOO FAR AWAY HAVE DECIDED
TO HOLD OFF ON ADDING ANY SHOWER/STORM MENTION AND MONITOR TRENDS.
MVFR/IFR CONDITIONS WILL LIKELY PERSIST THROUGH AT LEAST LATER TONIGHT.
&&
.UPDATE...
GRIDS/ZONES UPDATED TO REFLECT INCREASING CHANCES FOR ADDITIONAL
PRECIP IN MAINLY S/SE COUNTIES. SMALL WAVE MOVING ACROSS CENTRAL
INDIANA WAS WORKING SLOWLY NNE. LINE OF SHOWERS AND EMBEDDED
STORMS WAS WORKING NORTH WITH THIS FEATURE AND TRYING TO EXPAND.
HAVE TRIED TO CAPTURE GREATEST POTENTIAL IN FAR SE AREAS WITH CAT
POPS THROUGH MOST OF THE AFTERNOON AND A QUICK TAPER TO NO POPS
BEHIND THE COLD FRONT. CLOUD COVER HAS SLOWED DOWN THE WARMUP
SOMEWHAT...BUT NOT ENOUGH TO REQUIRE DRASTIC CHANGES IN FORECAST
HIGHS.
&&
.PREV DISCUSSION... /ISSUED 435 AM EDT WED SEP 26 2012/
SHORT TERM.../TODAY THROUGH THURSDAY NIGHT/
ANOTHER SHRTWV MOVG THROUGH THE UPR GRTLKS THIS MORNING WITH SFC CDFNT
MOVG SE TO JUST NW OF OUR CWA ATTM. LIGHT WINDS OVER THE AREA...
ESPCLY NRN PORTIONS COMBINED WITH MOIST AIRMASS AHEAD OF THE FRONT
RESULTING IN PATCHY FOG WHICH SHOULD PERSIST A SHORT WHILE BEYOND
DAYBREAK. NO CONVECTION ALONG FRONT MOVG THROUGH THE GRTLKS WITH
JUST STRATUS/FOG ACCOMPANYING IT OVER MI. WAA AHEAD OF THE FRONT
COMBINED WITH WK VORT MAXES EJECTING EASTWARD FROM WESTERN TROF
THROUGH THE PLAINS AND INTO THE OH VALLEY CONTG TO CAUSE CLUSTERS
OF TSTMS IN THAT AREA. SHOWERS/STORMS FOR THE MOST PART HAVE STAYED SOUTH
OF THE CWA THOUGH A CLUSTER DID IMPACT SRN PORTION OF OUR AREA
OVERNIGHT AND CONTS TO MOVE ACROSS SE ATTM. CDFNT WILL MOVE SLOWLY
SE ACROSS THE AREA TODAY. COMBINATION OF LOW LEVEL MOISTURE
CONVERGENCE AND POTENTIAL FOR ADDITIONAL WK SHRTWVS MOVG EAST INTO
THE OH VALLEY TODAY WITH MOIST/UNSTABLE AIRMASS IN PLACE AHEAD OF
THE FRONT SUPPORTS CONTINUING CHC OF SHOWERS/TSTMS ACROSS THE SE.
FRONT SHOULD MOVE SLOWLY SE OF THE AREA TONIGHT. CONTD WITH DRY
FCST BUT EXPECT SOME CLOUDINESS WILL LINGER OVER SRN PORTIONS OF
THE AREA. FAIR WX EXPECTED THU-THU NGT AS HIGH PRESSURE DRIFTS
EASTWARD ACROSS THE GRTLKS. FRONTAL BOUNDARY MOVG THROUGH OUR AREA
TODAY SHOULD STALL OVER THE OH VALLEY THU-THU NGT SO SOME
CLOUDINESS MAY PERSIST ACROSS SRN PORTIONS OF THE AREA THROUGH
THESE PERIODS.
TEMPS SHOULD BE CLOSE TO NORMAL THROUGH THE SHORT TERM PERIOD. GOING
FCST CLOSE TO LATEST GUIDANCE AND LITTLE CHANGE MADE BUT DID HEDGE
TOWARD SMALLER DIURNAL SWINGS SOUTH THAN NORTH DUE TO EXPECTATION OF
GREATER CLOUD COVER IN THAT PORTION OF THE CWA.
LONG TERM...
FRIDAY THROUGH TUESDAY...THE FORECAST CHALLENGES THIS PERIOD INCLUDE
THE DEVELOPMENT OF A CUT OFF LOW DOWNSTREAM OF A BLOCKING RIDGE.
FAVOR THE ECMWF THIS PACKAGE WITH AN UPPER LOW MOVING SOUTHWEST INTO
THE WESTERN GREAT LAKES REGION THIS WEEKEND. THE ECMWF HAS BEEN
TRENDING THIS UPPER LOW SOUTHWEST THE PAST 4 RUNS. HAVE KEPT THE
FORECAST DRY THROUGH THE PERIOD...BUT HAVE ADDED MORE CLOUDS LATE
SATURDAY THROUGH SUNDAY NIGHT AND HAVE LOWERED HIGH TEMPERATURES
SUNDAY. THE ISENTROPIC 295K LEVEL INDICATES THE UPPER LOW WILL BE
ABLE TO TAP A LITTLE BIT OF MOISTURE FROM THE ATLANTIC. THE GFS AND
CANADIAN 500 MB ANALOGS WERE STILL HAVING ISSUES HANDLING THE
DEVELOPMENT THIS UPPER LOW AS INDICATED BY CORRELATION COEFFICIENTS
BELOW 0.80. ASSOCIATED WITH THIS PATTERN...A PERSISTENT NORTHEAST TO
EAST LOW LEVEL FLOW SHOULD HELP KEEP A COOL FETCH OUT OF CANADA...
ALLOWING TEMPERATURES TO BE BELOW NORMAL SUNDAY. CURRENT THINKING
IS LOWS GENERALLY IN THE MID TO UPPER 40S...AND HIGHS IN THE MID TO
UPPER 60S...RISING INTO 70S BY TUESDAY AS THE UPPER LOW LIFTS
NORTHEAST.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...RIP CURRENT RISK THROUGH LATE TONIGHT FOR INZ003.
MI...RIP CURRENT RISK THROUGH LATE TONIGHT FOR MIZ077.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...FISHER
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
304 PM CDT WED SEP 26 2012
...UPDATED FOR THE LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1214 AM CDT WED SEP 26 2012
AT 00Z WEDNESDAY A 500MB LOW WAS LOCATED JUST NORTH OF THE FOUR
CORNERS REGION WITH A 250MB 55KT JET STREAK LOCATED ON ITS WEST
SIDE DIVING SOUTH ACROSS WESTERN NEVADA. ANOTHER 50KT JET WAS
LOCATED IN THE BASED ON THIS UPPER LOW/TROUGH OVER NORTHERN
NEVADA. FURTHER EAST ACROSS SOUTHWEST KANSAS THE WATER VAPOR LOOP
AND RAP 400MB POTENTIAL VORTICITY INDICATED AN UPPER LEVEL TROUGH
MOVING EAST FROM SOUTHEAST COLORADO INTO SOUTHWEST KANSAS. CLOUD
TOPS WERE COOLING AHEAD OF THIS FEATURE FROM 00Z- 02Z. A 700MB
BAROCLINIC ZONE WAS ALSO LOCATED IN THIS AREA AT 00Z AND AT THE
850MB LEVEL WARM AIR ADVECTION WAS LOCATED ALONG AND NORTH OF A
SURFACE BOUNDARY WHICH WAS LOCATED FROM THE PANHANDLE OF OKLAHOMA
ACROSS SOUTH CENTRAL KANSAS.
&&
.UPDATE...
ISSUED AT 953 AM CDT WED SEP 26 2012
A CLUSTER OF ELEVATED THUNDERSTORMS THAT ORIGINATED NEAR THE 310K
THETA LEVEL IN WEAK WESTERLY ISENTROPIC LIFT NEAR THE COLORADO LINE
THIS MORNING, HAS DECAYED ALONG AND EAST OF THE HIGHWAY 83 CORRIDOR.
THERE DOES NOT APPEAR TO BE AN IMMEDIATE MECHANISM TO DEVELOP
ADDITIONAL CONVECTION, AND PROBABILITIES HAVE BEEN REDUCED
SIGNIFICANTLY FROM NOW UNTIL THE AFTERNOON WHEN INSTABILITY INCREASES.
A MID LEVEL CLOUD FIELD ASSOCIATED WITH CONVECTIVE OUTFLOW AND A MID
LEVEL BAROCLINIC ZONE IS HAVING A LARGE EFFECT ON RAP MODEL MAX
TEMPERATURES ACROSS CENTRAL KANSAS. TEMPERATURE WILL LIKELY NOT
EXCEED 70 DEGREES THIS AFTERNOON IN A COOL CLOUDY REGIME THROUGH
THE INTERSTATE 70 CORRIDOR.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 147 AM CDT WED SEP 26 2012
SATELLITE LOOP INDICATING SKIES ATTEMPTING TO CLEAR BEHIND THE
FIRST UPPER LEVEL TROUGH THAT WAS CROSSING SOUTHWEST KANSAS
EARLIER THIS MORNING. THIS FIRST WAVE WAS REFLECTED WELL BY THE
WATER VAPOR LOOP AND RAP 400MB POTENTIAL VORTICITY. AS THIS SYSTEM
EXITS WESTERN KANSAS THE PRECIPITATION CHANCES WILL DROP WITH THE
POSSIBLE EXCEPTION OF NORTH CENTRAL KANSAS AS ANOTHER WEAKER WAVE
CROSSES SOUTHWEST KANSAS EARLY WEDNESDAY MORNING. WILL MONITOR
TREND AND INSERT A PERIOD OF EARLY MORNING CLOUDS AND POSSIBLE
LIGHT RAINSHOWERS/SPRINKLES AS NEEDED.
THE NEXT DECENT CHANCE FOR MEASURABLE PRECIPITATION WILL BE LATE
TODAY AND ESPECIALLY OVERNIGHT AS THE UPPER LEVEL JET THAT WAS
LOCATED OVER NEVADA ROTATES AROUND THE 500MB LOW AND APPROACHES
THE AREA. NAM AND GFS WERE IN DECENT AGREEMENT WITH THE PLACEMENT
OF THIS UPPER LEVEL FEATURE LATE TODAY WITH IMPROVING 850-700MB MOISTURE
AND FRONTOGENESIS DEVELOPING NORTH OF THE COLD FRONT. 00Z NAM AND
00Z GFS DO HOWEVER DIFFER SLIGHTLY ON THE LOCATION ON WHERE THE
BETTER FRONTOGENESIS BUT THE GENERAL TREND IS CONVECTION CHANCES
IMPROVING FROM WEST TO EAST LATE TODAY ACROSS WESTERN KANSAS.
AROUND 40 KNOTS OF 0-6KM SHEAR ARE EXPECTED BY LATE DAY BASED ON
THE 00Z NAM. CAPE VALUES WILL ACROSS WESTERN KANSAS ARE EXPECTED
TO BE AROUND 1000J/KG WITH 0-2.5KM LAPSE RATES EXCEEDING 8C/KM.
GIVEN THIS AND SOME LATE DAY FORCING DEVELOPING WILL KEEP A
MENTION OF SEVERE STORMS GOING IN THE HAZARDOUS WEATHER OUTLOOK.
MAIN HAZARD APPEARS TO BE HAIL.
AS FOR TEMPERATURES...THE OVERNIGHT RAINFALL AND EXPECTED CLOUD
COVER LATER TODAY SHOULD LIMIT THE WARM UP THIS AFTERNOON. AT THIS
TIME WILL TREND TOWARDS THE COOLER GUIDANCE WHICH SUPPORTS THE
850MB MIX DOWN TEMPERATURES FROM THE NAM AND GFS ALONG WITH WHAT
THE PREVIOUS SHIFT SUGGESTED. WILL ALSO NOT DEVIATE FAR FROM THE
LOWS TONIGHT GIVEN THE MID 50S TO NEAR 60 DEWPOINTS FORECAST NORTH
OF THE FRONT ACROSS SOUTHWEST KANSAS AND EXPECTED CLOUD COVER.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 303 PM CDT WED SEP 26 2012
THE THURSDAY NIGHT PERIOD WILL CONTINUE TO BE WET WITH A FRONT
STRETCHED SOUTHWEST TO NORTHEAST ACROSS OUR CWA AND AN UPPER WAVE
STILL TRANSITIONING EASTWARD. THERE WILL BE 50 PERCENT POPS IN OUR
SOUTHEAST ZONES AROUND MEDICINE LODGE, 40 PERCENT FROM LARNED TO
LIBERAL, AND 30 PERCENT POPS WEST OF THERE. THE UPPER WAVE WILL
MOVE FARTHER EAST ON FRIDAY INTO WICHITA`S AREA, BUT THE FRONT WILL
STILL LINGER OVER OUR SOUTHERN CWA NEAR THE OKLAHOMA BORDER. POPS
WILL DECREASE DURING FRIDAY MORNING FROM NORTHWEST TO SOUTHEAST. ON
FRIDAY NIGHT, THERE COULD BE SOME MORE CONVECTION ALONG AND NORTH OF
THE FRONT, BUT THERE IS A MUCH LOWER CHANCE THAN ON THURSDAY NIGHT
WHEN THERE IS UPPER SUPPORT. FOR SATURDAY, SLOWLY DECREASED THE
POPS TO LESS THAN 15 PERCENT BY 00Z SUNDAY. THE UPPER SUPPORT/WAVE
TO PRODUCE RAIN WILL BE WELL EAST OF OUR CWA BY SUNDAY NIGHT. SO,
NO POPS ARE IN THE PLANS AFTER ABOUT 21Z SATURDAY. CLOUDS WILL
CLEAR, SUNNY SKIES RESULT AND A WARMING TREND WILL SET IN FROM
SUNDAY INTO WEDNESDAY. THE QPF COULD END UP SUBSTANTIAL FOR A FEW
SPOTS IN OUR CWA BETWEEN TONIGHT AND SATURDAY, ESPECIALLY ACROSS OUR
SOUTHERN COUNTIES. I RAN A STORMTOTALQPF GRID FOR THAT TIME PERIOD,
AND OVER 1.20 INCHES SHOWED UP SOUTH OF JOHNSON CITY TO DODGE CITY
TO PRATT LINE. NORTH OF THAT LINE, 0.50 TO 0.75 INCHES ARE
POSSIBLE. AS ALWAYS, SOME PLACE WILL END UP WITH A HIGHER AMOUNT,
AND MANY OTHER SPOTS WILL GET MUCH LESS RAINFALL.
AS FOR TEMPERATURES, MAXIMUM TEMPERATURES IN THE LOWER TO MID 70S ON
A RAINY FRIDAY WILL WARM TO THE UPPER 70S UNDER A PARTLY SUNNY
SUNDAY SKY, WHICH WILL BE CLEARING SUNDAY NIGHT. UNDER SUNNY SKIES
AND RATHER LIGHT WINDS, TEMPERATURES SHOULD WARM UP TO THE MID 80S
FOR BOTH TUESDAY AND WEDNESDAY. THE MODELS SUPPORT LOW TEMPERATURES
IN THE IN THE UPPER 50S TO LOWER 60S FRIDAY MORNING, COOLING TO MID
50S BY SUNDAY MORNING, AND BASICALLY STAYING IN THE MIDDLE TO UPPER
50S THROUGH WEDNESDAY.
THE EC AND THE GEM MODELS ARE IN GOOD AGREEMENT AT BOTH THE H5 AND
SURFACE PRESSURE PROGS, WITH THE GFS FASTER WITH THE UPPER WAVE
MOVING EAST AND ALSO PORTRAYS THE UPPER LOW TO BE FARTHER NORTH THAN
EITHER THE ECMWF OR GEM MODELS DO. GRIDS ARE IN FINE AGREEMENT WITH
SURROUNDING WFO`S ISC GRIDS, AND SEEM REASONABLE WITH RESPECT TO THE
ECMWF AND GEM MODELS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 654 AM CDT WED SEP 26 2012
NORTHEAST TO EASTERLY UPSLOPE FLOW WILL PERSIST THROUGH THE TAF
PERIOD TO THE NORTH OF A STATIONARY FRONT. THERE IS A CHANCE FOR
THUNDERSTORMS IN VICINITY OF THE TAF SITES, ESPECIALLY AFTER 23Z
AND THROUGH THE END OF THE TAF PERIOD. OUTSIDE OF THUNDERSTORMS
VFR CONDITIONS WILL PERSIST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 58 76 61 73 / 60 60 50 40
GCK 56 75 59 71 / 50 50 40 30
EHA 55 76 58 74 / 50 40 30 30
LBL 57 77 60 73 / 50 60 40 40
HYS 56 74 59 71 / 40 40 40 40
P28 62 78 62 75 / 50 50 50 50
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RUSSELL
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...BURKE
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS WICHITA KS
229 PM CDT WED SEP 26 2012
.DISCUSSION...
SYNOPSIS...THE MCV LEFT FROM LAST NIGHTS CONVECTION WAS CENTERED
ABOUT 55 MILES NORTHWEST OF SALINA. CONVECTION FROM THIS IS
FESTERING NEAR AND EAST OF THE CENTER...EXTENDING INTO MISSOURI.
A STRONG RESIDENT COLD POOL REMAINED IN PLACE ACROSS THE FORECAST
AREA FOR MUCH OF THE MORNING...MAKING RECOVERY OF THE ATMOSPHERE
QUITE SLOW. OF NOTE AS WELL IN THE VISIBLE IMAGERY ARE GRAVITY
WAVES PROPAGATING AWAY FROM THE CONVECTION TO THE SOUTH AND
SOUTHWEST...THE MOST RECENT OF WHICH HAS INCREASING CONVERGENCE
ALONG IT.
THE COLD POOL HAS PUSHED THE COLD FRONT ALL THE WAY INTO OKLAHOMA
AND ARKANSAS...WITH AN 18Z POSITION EXTENDING FROM A
KRUE-KFSM-KOKC-KDDC APPROXIMATION.
FROM 18Z TO 19Z...TEMPERATURES HAVE RISEN INTO THE MID 70S ACROSS
SOUTH-CENTRAL KANSAS WHERE THE COLD POOL HAS NEARLY MIXED OUT. SOME
CUMULUS HAVE STARTED TO FORM IN THIS AREA AS A RESULT.
UPPER LEVEL ANALYSIS ENDING AT 19Z SHOWS AN UPPER LOW CENTERED OVER
THE FOUR CORNERS REGION...WITH IMPULSES OF ENERGY ROTATING AROUND
IT. THESE ARE THE MAIN IMPULSES AFFECTING THE AREA.
ANOTHER DISTURBANCE WAS NOTED IN THE WATER VAPOR IMAGERY MOVING
ALONG THE U.S. CANADIAN BORDER OF CENTRAL MONTANA. A VERY DEEP AREA
OF LOW PRESSURE WAS OVER THE GULF OF ALASKA WITH WEAKENING LOW
PRESSURE OVER NORTHERN QUEBEC.
THE MAIN FORECAST FOCUS WILL BE ON CONVECTION OVER THE NEXT SEVERAL
DAYS.
TONIGHT - THE MAIN FORCING MECHANISM FOR CONVECTION SHOULD ONCE
AGAIN BE LOW LEVEL MOISTURE TRANSPORT INTERSECTING THE FRONT. THE
MOISTURE TRANSPORT VECTORS...ISENTROPIC LIFT AT 305K AND 310K...AND
THE 1000MB-850MB FRONTOGENESIS REALLY ISOLATE WHERE THIS SHOULD
OCCUR. THE BULK OF THE NWP CONTINUE TO FAVOR AN AREA OVER SOUTHEAST
KANSAS. THIS IS EXPECTED TO OCCUR LATE THIS EVENING.
A SECOND AREA SHOULD CONTINUE IN THE VICINITY OF THE MCV...WHERE
CONVECTION FESTERS THIS AFTERNOON. A THIRD AND FINAL AREA OF
CONVECTION WILL MOVE INTO THE AREA FROM THE WEST. THE NAM-WRF
AND THE HRRR BOTH SHOW STORMS MOVING OFF THE HIGH PLAINS INTO THE
WESTERN PART OF THE STATE. THESE REACH THE FORECAST AREA AT VARIOUS
TIMES. THE HRRR /MULTIPLE RUNS FROM 10Z THROUGH 15Z/ BRING THIS
CONVECTION INTO WESTERN KANSAS BY 01Z...THE 26.12Z NAM-WRF BRINGS IT
INTO WESTERN KANSAS BETWEEN 06Z AND 09Z.
THIS HAS A GREAT AFFECT ON THE FORECAST AND WHETHER WE GET
ADDITIONAL CONVECTION ALONG THE SOUTHERN PERIPHERY OF THE FORECAST
AREA. HAVE LOW CONFIDENCE IN TIMING OF THIS SYSTEM. THE LATEST RAP
AT 18Z SHOWS A STRONG LOW LEVEL JET ACROSS THE HIGH PLAINS...WHICH
WOULD FAVOR THE NAM-WRF. STILL...CONFIDENCE IS RATHER LOW.
THURSDAY - ANY ONGOING CONVECTION IN THE MORNING SHOULD GRADUALLY
DIMINISH DURING THE MORNING. DURING THE AFTERNOON...THERE SHOULD BE
ENOUGH RESIDUAL MOISTURE IN THE BOUNDARY LAYER TO ENABLE SOME
ADDITIONAL SHOWERS AND THUNDERSTORMS...THOUGH NOTHING LOOKS
ORGANIZED AT THIS TIME.
FRIDAY THROUGH WEDNESDAY - HIGH PRESSURE MOVES INTO THE
REGION...BOTH THE 26.12Z ECMWF AND THE 26.12Z GFS AGREE ON THAT.
THEY ALSO HAVE A COLD FRONT...ASSOCIATED WITH A LOW IN THE NORTHERN
STREAM UP IN CANADA...MOVING THROUGH THE REGION ON SUNDAY. THIS
FRONT SHOULD BE DRY SINCE THE GULF IS CLOSED OFF.
ON WEDNESDAY...ANOTHER COLD FRONT MOVES SOUTH THEN STALLS OVER THE
REGION. PRECIPITATION CHANCES WITH THIS FRONT SHOULD BE A BIT
BETTER.
LOOKING OUT AHEAD...A SIGNIFICANT PATTERN CHANGE MAY BE UNDERWAY. A
VERY DEEP TROUGH IS FORECAST TO DEVELOP OVER THE WESTERN U.S. THIS
PRODUCES A STRONG DEEP SURFACE LOW OVER THE NATIONS
MID-SECTION...WITH STRONG HIGH PRESSURE OVER THE NORTHWESTERN U.S.
AND CANADA IN THE LEE OF THE ROCKIES. THIS COULD BE THE FIRST
SIGNIFICANT SNOW STORM OF THE SEASON FOR THE NORTHERN PLAINS AND
SOUTHERN CANADA.
COOK
&&
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
SCATTERED SHOWERS/T-STORMS EXPECTED TO CONTINUE OVER CENTRAL KS
THIS AFTERNOON UNDERNEATH WEAK MID-LEVEL CYCLONIC CIRCULATION
CENTER. A FEW LINGERING SHOWERS WILL LINGER OVER SOUTHEAST KS.
SURFACE-850 FRONTAL ZONE WILL BE A BIT FURTHER SOUTH
TONIGHT...STRETCHING FROM WEST-CENTRAL OKLAHOMA TO FAR SOUTHEAST
KS. THIS WILL BE THE FOCUS FOR THUNDERSTORM DEVELOPMENT WITH
ANOTHER LOW-LEVEL JET DEVELOPING SOUTH OF THE BOUNDARY. THIS
ACTIVITY COULD AFFECT CNU AND WILL INCLUDE A VCTS THERE.
INSTABILITY WILL BE MUCH LESS FURTHER NORTH/NORTHWEST AND WILL
KEEP PRECIPITATION OUT OF THE REMAINING TAF SITES. VFR TO PREVAIL
OUTSIDE OF ANY STORM ACTIVITY.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 64 78 62 73 / 60 50 50 50
HUTCHINSON 62 77 60 72 / 50 50 40 50
NEWTON 62 76 60 72 / 60 40 40 50
ELDORADO 63 77 61 73 / 60 40 50 50
WINFIELD-KWLD 65 79 63 74 / 70 60 50 50
RUSSELL 58 75 58 71 / 30 40 40 40
GREAT BEND 60 76 59 72 / 40 40 40 40
SALINA 61 77 59 74 / 40 30 40 40
MCPHERSON 61 77 60 72 / 50 40 40 40
COFFEYVILLE 64 82 64 75 / 90 60 50 50
CHANUTE 64 78 62 74 / 80 50 50 50
IOLA 64 76 61 74 / 70 50 50 50
PARSONS-KPPF 64 80 63 74 / 80 60 50 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
650 PM EDT WED SEP 26 2012
.UPDATE...
ISSUED AT 650 PM EDT WED SEP 26 2012
SCATTERED CONVECTION CONTINUES TO DRIFT ACROSS OUR BLUEGRASS COUNTIES
THIS EVENING WITH RAINFALL THUS FAR LESS THAN 1/4 INCH. THE NEAR TERM
GUIDANCE GENERALLY APPEARS TO HAVE A GOOD HANDLE ON THE SCATTERED
CONVECTION UPSTREAM OVER WRN KY...DEPICTING THIS ACTIVITY TO
DISSIPATE OVER THE NEXT FEW HOURS BEFORE REACHING THE CWA...WITH
RESIDUAL ACTIVITY OVERNIGHT REMAINING BELOW SEVERE LIMITS AND
PREDOMINANTLY AFFECTING AREAS OVER NERN KY. THE CURRENT FORECAST HAS
ALL OF THIS WELL IN HAND...AND GENERALLY ONLY NEEDED MINOR MASSAGING
TO THE TEMP AND DEW PT CURVES HEADING INTO THE OVERNIGHT PERIOD.
METMOS APPEARS TO HAVE A FAIRLY GOOD HANDLE ON THE TEMP/DEW PT REGIME
ATTM...AND IS HINTING AT SOME TYPICAL ERN KY PATCHY VALLEY FOG
TOWARDS DAWN...SO WILL ADD THIS TO THE MIX FOR AREAS GENERALLY ALONG
AND SOUTH OF THE HAL ROGERS/KY 80 CORRIDOR WHERE CLEARER SKIES ARE
EXPECTED TO PREVAIL OVERNIGHT. UPDATED GRIDS HAVE BEEN SENT...AND
FRESH ZONES WILL BE ISSUED SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 309 PM EDT WED SEP 26 2012
QUASI STATIONARY FRONTAL BOUNDARY REMAINS FROM LAKE ONTARIO TO
NORTHERN ILLINOIS...WHILE ANOTHER WEAK BOUNDARY IS ACROSS NORTHERN
KY. A SERIES OF CONVECTIVE COMPLEXES HAS BEEN MOVING ENE THROUGH THE
OH VALLEY...AND THIS SCENARIO LOOKS TO CONTINUE THROUGH THE FORECAST
PERIOD...WITH A GRADUAL SHIFT SOUTH OF THE ACTIVITY AS THE PRIMARY FRONT
SAGS SOUTH. MODEL CONSENSUS IS THAT THE FOCUS OF THE REPEATED RAINS
WILL BE NORTHWEST OF THE FORECAST AREA...AND THUS HEAVIEST RAIN
TOTALS ARE EXPECTED TO REMAIN OUTSIDE OF FORECAST AREA. HPC HAS
PLACED THE EXTREME WESTERN EDGE OF THE FORECAST AREA IN A SLIGHT RISK
FOR EXCESSIVE RAINS. PRECIPITABLE WATER IS FORECAST TO BE IN EXCESS
OF THE 75TH PERCENTILE...BUT NOT TO BECOME TOO EXCESSIVE WITH PW
GETTING UP NEAR 1.5 INCHES. NONE THE LESS IF THE THE REPEATED RAINS
SET UP FURTHER SOUTH THE SITUATION WILL NEED TO BE MONITORED
CLOSELY. HOWEVER FLOOD THREAT FOR OUR AREA LOOKS MINIMAL AT THIS TIME.
CONVECTION CURRENTLY OVER SOUTHEASTERN INDIANA SHOULD REMAIN NORTH
OF THE FORECAST AREA LATE THIS AFTERNOON AND EVENING...BUT MAY
AFFECT THE FAR NORTHERN PART OF THE FORECAST AREA IF DEVELOPMENT
OCCURS FURTHER TO THE SOUTH. CONVECTION NOW OVER SOUTHEASTERN MO IS
MORE LIKELY TO AFFECT THE FORECAST AREA TONIGHT...AND THIS IS PICKED
UP ON BY THE HRRR.
LOW LEVEL JET LOOKS TO INCREASE EARLY TONIGHT...SO THIS SHOULD HELP TO
INCREASE THE PRECIPITATION CHANCES...MAINLY IN THE NORTH. THE
NORTHERN PART OF THE FORECAST AREA ALSO REMAINS IN A SLIGHT RISK FOR
SEVERE THUNDERSTORMS PER THE LATEST SPC DAY 1 OUTLOOK. HOWEVER SINCE
CONVECTION DID NOT DEVELOP THIS AFTERNOON ALONG THE OLD BOUNDARY
CURRENTLY OVER THE AREA IT APPEARS THE THREAT FOR SEVERE WEATHER WILL
BE DECREASING. IT APPEARS WE WILL NEED TO WAIT FOR THE COMPLEX
CURRENTLY DEVELOPING OVER MO TO MOVE ACROSS THE AREA TONIGHT. HOWEVER
BASED ON LATEST HRRR SHORT RANGE GUIDANCE THIS CONVECTION SHOULD
WEAKEN AS IT MOVES INTO OUR AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 PM EDT WED SEP 26 2012
MODELS ARE IN FAIR AGREEMENT TO START THE EXTENDED FCST. A SLOWLY
SAGGING TROF EXTENDS FROM WEST TO EAST ACROSS THE COMMONWEALTH. PCPN
IN THE FORM OF WAVES TRACKS ALONG THE FRONTAL ZONE WITH DIFFERENCES
IN THE DETAILS. HIGH PRESSURE FORCES THE FRONTAL ZONE SOUTH OF THE
STATE WITH THE GFS SLIGHTLY QUICKER IN CLEARING OUT THE PCPN. HAVE
CHOSEN TO FOLLOW THIS TREND AS THE HIGH PRESSURE OVER THE NORTHERN
PLAINS INITIALIZES BETTER IN THIS RUN. THIS PLACES CHANCE POPS
ACROSS THE ENTIRE CWFA WITH 30S IN THE NORTH AND 50S SOUTH ON FRI.
FRI NITE AND SAT SHOWS CLEARING IN THE NORTH WITH CHANCE POPS IN THE
SOUTH FOLLOWED ON SAT NITE WITH NO POPS FOR THE ENTIRE AREA. THE DRY
WEATHER THEN CONTINUES THRU THE REMAINDER OF THE FCST AS HIGH
PRESSURE SETTLES OVER THE CNTRL APPALACHIANS AND THE MID ATLANTIC
COAST. THIS HIGH EXTENDS WEST INTO THE CNTRL PLAINS AND CUTS OFF ANY
RETURN FLOW FROM THE GULF. HENCE THE DEWPOINTS WILL DROP AS THE
DRIER AIR SETTLES IN WITH THE PLAINS HIGH WITH VALUES IN THE UPPER
40S AND LOWER 50S. TEMPERATURES WILL START IN THE MID 70S ON FRI BUT
DROP TO THE UPPER 60S WITH THE CLOUDS AND RAIN ON SAT. THEN AS THE
FRONT EASES SOUTH LOOK FOR HIGH TEMPS TO RECOVER INTO THE LOWER 70S
ON SUN AND CONTINUE CLIMBING SLOWLY TO THE MID 70S AGAIN BY WED.
LOWS WILL REMAIN FAIRLY STEADY IN THE 50S WITH MONDAY MORNING THE
COOLEST AS THE MERCURY SHOULD FALL TO AROUND 50.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 150 PM EDT WED SEP 26 2012
QUASI STATIONARY FRONTAL BOUNDARY REMAINS FROM LAKE ONTARIO TO
NORTHERN ILLINOIS. THERE IS ALSO A WEAK BOUNDARY FURTHER SOUTH WHICH
IS ACROSS NORTHERN KY. CONVECTION CURRENTLY OVER SOUTHERN INDIANA
MAY AFFECT THE FAR NORTHERN PART OF THE FORECAST AREA DURING THE LATE
AFTERNOON WHILE CONVECTION OVER SOUTHERN ILLINOIS MAY AFFECT THE
NORTHERN PART OF THE FORECAST AREA THIS EVENING.
CONVECTION OVER THE CENTRAL AND SOUTHERN PART OF THE FORECAST
AREA...WHILE POSSIBLE TONIGHT...IS NOT LIKELY...AND AT THIS TIME WILL
LEAVE ALL MENTION OF THUNDER OUT OF TAF SITES. CLOUDS WILL BE ON THE
INCREASE DURING THE FORECAST PERIOD...BUT ANY CEILINGS AT THE TAF
SITES ARE EXPECTED TO REMAIN VFR. SOME MVFR CEILINGS WILL BE POSSIBLE
THIS AFTERNOON AND TONIGHT IN THE NORTHERN PART OF THE FORECAST AREA.
CLOUDS WILL ALSO LIMIT FOG TONIGHT...WITH AREAS OUTSIDE OF PRECIPITATION
HAVING MOSTLY VFR VISIBILITY THROUGH THE FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MB
SHORT TERM...SBH
LONG TERM....DUSTY
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
310 PM EDT WED SEP 26 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 309 PM EDT WED SEP 26 2012
QUASI STATIONARY FRONTAL BOUNDARY REMAINS FROM LAKE ONTARIO TO
NORTHERN ILLINOIS...WHILE ANOTHER WEAK BOUNDARY IS ACROSS NORTHERN
KY. A SERIES OF CONVECTIVE COMPLEXES HAS BEEN MOVING ENE THROUGH THE
OH VALLEY...AND THIS SCENARIO LOOKS TO CONTINUE THROUGH THE FORECAST
PERIOD...WITH A GRADUAL SHIFT SOUTH OF THE ACTIVITY AS THE PRIMARY FRONT
SAGS SOUTH. MODEL CONSENSUS IS THAT THE FOCUS OF THE REPEATED RAINS
WILL BE NORTHWEST OF THE FORECAST AREA...AND THUS HEAVIEST RAIN
TOTALS ARE EXPECTED TO REMAIN OUTSIDE OF FORECAST AREA. HPC HAS
PLACED THE EXTREME WESTERN EDGE OF THE FORECAST AREA IN A SLIGHT RISK
FOR EXCESSIVE RAINS. PRECIPITABLE WATER IS FORECAST TO BE IN EXCESS
OF THE 75TH PERCENTILE...BUT NOT TO BECOME TOO EXCESSIVE WITH PW
GETTING UP NEAR 1.5 INCHES. NONE THE LESS IF THE THE REPEATED RAINS
SET UP FURTHER SOUTH THE SITUATION WILL NEED TO BE MONITORED
CLOSELY. HOWEVER FLOOD THREAT FOR OUR AREA LOOKS MINIMAL AT THIS TIME.
CONVECTION CURRENTLY OVER SOUTHEASTERN INDIANA SHOULD REMAIN NORTH
OF THE FORECAST AREA LATE THIS AFTERNOON AND EVENING...BUT MAY
AFFECT THE FAR NORTHERN PART OF THE FORECAST AREA IF DEVELOPMENT
OCCURS FURTHER TO THE SOUTH. CONVECTION NOW OVER SOUTHEASTERN MO IS
MORE LIKELY TO AFFECT THE FORECAST AREA TONIGHT...AND THIS IS PICKED
UP ON BY THE HRRR.
LOW LEVEL JET LOOKS TO INCREASE EARLY TONIGHT...SO THIS SHOULD HELP TO
INCREASE THE PRECIPITATION CHANCES...MAINLY IN THE NORTH. THE
NORTHERN PART OF THE FORECAST AREA ALSO REMAINS IN A SLIGHT RISK FOR
SEVERE THUNDERSTORMS PER THE LATEST SPC DAY 1 OUTLOOK. HOWEVER SINCE
CONVECTION DID NOT DEVELOP THIS AFTERNOON ALONG THE OLD BOUNDARY
CURRENTLY OVER THE AREA IT APPEARS THE THREAT FOR SEVERE WEATHER WILL
BE DECREASING. IT APPEARS WE WILL NEED TO WAIT FOR THE COMPLEX
CURRENTLY DEVELOPING OVER MO TO MOVE ACROSS THE AREA TONIGHT. HOWEVER
BASED ON LATEST HRRR SHORT RANGE GUIDANCE THIS CONVECTION SHOULD
WEAKEN AS IT MOVES INTO OUR AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 PM EDT WED SEP 26 2012
MODELS ARE IN FAIR AGREEMENT TO START THE EXTENDED FCST. A SLOWLY
SAGGING TROF EXTENDS FROM WEST TO EAST ACROSS THE COMMONWEALTH. PCPN
IN THE FORM OF WAVES TRACKS ALONG THE FRONTAL ZONE WITH DIFFERENCES
IN THE DETAILS. HIGH PRESSURE FORCES THE FRONTAL ZONE SOUTH OF THE
STATE WITH THE GFS SLIGHTLY QUICKER IN CLEARING OUT THE PCPN. HAVE
CHOSEN TO FOLLOW THIS TREND AS THE HIGH PRESSURE OVER THE NORTHERN
PLAINS INITIALIZES BETTER IN THIS RUN. THIS PLACES CHANCE POPS
ACROSS THE ENTIRE CWFA WITH 30S IN THE NORTH AND 50S SOUTH ON FRI.
FRI NITE AND SAT SHOWS CLEARING IN THE NORTH WITH CHANCE POPS IN THE
SOUTH FOLLOWED ON SAT NITE WITH NO POPS FOR THE ENTIRE AREA. THE DRY
WEATHER THEN CONTINUES THRU THE REMAINDER OF THE FCST AS HIGH
PRESSURE SETTLES OVER THE CNTRL APPALACHIANS AND THE MID ATLANTIC
COAST. THIS HIGH EXTENDS WEST INTO THE CNTRL PLAINS AND CUTS OFF ANY
RETURN FLOW FROM THE GULF. HENCE THE DEWPOINTS WILL DROP AS THE
DRIER AIR SETTLES IN WITH THE PLAINS HIGH WITH VALUES IN THE UPPER
40S AND LOWER 50S. TEMPERATURES WILL START IN THE MID 70S ON FRI BUT
DROP TO THE UPPER 60S WITH THE CLOUDS AND RAIN ON SAT. THEN AS THE
FRONT EASES SOUTH LOOK FOR HIGH TEMPS TO RECOVER INTO THE LOWER 70S
ON SUN AND CONTINUE CLIMBING SLOWLY TO THE MID 70S AGAIN BY WED.
LOWS WILL REMAIN FAIRLY STEADY IN THE 50S WITH MONDAY MORNING THE
COOLEST AS THE MERCURY SHOULD FALL TO AROUND 50.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 150 PM EDT WED SEP 26 2012
QUASI STATIONARY FRONTAL BOUNDARY REMAINS FROM LAKE ONTARIO TO
NORTHERN ILLINOIS. THERE IS ALSO A WEAK BOUNDARY FURTHER SOUTH WHICH
IS ACROSS NORTHERN KY. CONVECTION CURRENTLY OVER SOUTHERN INDIANA
MAY AFFECT THE FAR NORTHERN PART OF THE FORECAST AREA DURING THE LATE
AFTERNOON WHILE CONVECTION OVER SOUTHERN ILLINOIS MAY AFFECT THE
NORTHERN PART OF THE FORECAST AREA THIS EVENING.
CONVECTION OVER THE CENTRAL AND SOUTHERN PART OF THE FORECAST
AREA...WHILE POSSIBLE TONIGHT...IS NOT LIKELY...AND AT THIS TIME WILL
LEAVE ALL MENTION OF THUNDER OUT OF TAF SITES. CLOUDS WILL BE ON THE
INCREASE DURING THE FORECAST PERIOD...BUT ANY CEILINGS AT THE TAF
SITES ARE EXPECTED TO REMAIN VFR. SOME MVFR CEILINGS WILL BE POSSIBLE
THIS AFTERNOON AND TONIGHT IN THE NORTHERN PART OF THE FORECAST AREA.
CLOUDS WILL ALSO LIMIT FOG TONIGHT...WITH AREAS OUTSIDE OF PRECIPITATION
HAVING MOSTLY VFR VISIBILITY THROUGH THE FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SBH
LONG TERM....DUSTY
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
151 PM EDT WED SEP 26 2012
.UPDATE...
ISSUED AT 150 PM EDT WED SEP 26 2012
ISSUED AN UPDATE TO NDFD FOR LATEST OBSERVATIONAL TRENDS. CU ALONG
BOUNDARY FROM THIS MORNINGS CONVECTION HAS DECREASED OVER THE PAST
HOUR AND ADDITIONAL CONVECTIVE DEVELOPMENT THIS AFTERNOON OVER THE
CENTRAL AND SOUTHERN PART OF FORECAST AREA LOOKING LESS AND LESS
LIKELY. HAVE REMOVED ALL RAIN CHANCES FOR THIS AFTERNOON SOUTH OF A
MOUNT VERNON TO SANDY HOOK LINE.
QUASI STATIONARY FRONTAL BOUNDARY REMAINS FROM LAKE ONTARIO TO
NORTHERN ILLINOIS. CONVECTION CURRENTLY OVER SOUTHERN INDIANA MAY
AFFECT THE FAR NORTHERN PART OF THE FORECAST AREA DURING THE LATE
AFTERNOON WHILE CONVECTION OVER SOUTHERN ILLINOIS MAY AFFECT THE
NORTHERN PART OF THE FORECAST AREA THIS EVENING.
UPDATE ISSUED AT 1114 AM EDT WED SEP 26 2012
WILL BE UPDATING NDFD AND ASSOCIATED PRODUCTS BY 1140 AM EDT.
SHOWERS AND THUNDERSTORMS HAVE ENDED ACROSS THE FAR NORTH. BOUNDARY
EVIDENT ON SATELLITE FROM NEAR HUNTINGTON WV TO SOUTH OF MOREHEAD TO
SOUTH OF MOUNT STERLING. SOME CONVECTION COULD DEVELOP ALONG THIS
WITHIN THE NEXT COUPLE OF HOURS AND THIS IS HINTED AT IN THE HRRR.
HOWEVER FEEL THAT ANY CONVECTION WILL REMAIN ISOLATED THROUGH MOST OF
THE AFTERNOON...WITH BETTER CHANCE THIS EVENING. THIS IDEA IS
SUPPORTED BY THE 12Z NAM AND LATEST HRRR AND HAVE ADJUSTED HOURLY
NDFD ACCORDINGLY.
UPDATE ISSUED AT 948 AM EDT WED SEP 26 2012
UPDATED NDFD AND ASSOCIATED PRODUCTS TO DEPICT CURRENT AREA OF
SHOWERS AND THUNDERSTORMS THAT IS ABOUT TO IMPACT THE FAR NORTHERN
PART OF THE FORECAST AREA. THIS HAS RESULTED IN A SIGNIFICANT
GRADIENT IN THE PROBABILITY OF PRECIPITATION FOR TODAY...RANGING
FROM 100 PERCENT IN THE FAR NORTH TO 20 PERCENT IN THE FAR SOUTH. SPC
HAS ALSO PLACED THE NORTHERN TWO THIRDS OF THE FORECAST AREA IN A
SLIGHT RISK FOR THIS AFTERNOON AND EVENING...AND HAVE UPDATED THE HWO
AS WELL FOR THIS. THIS MORNINGS SHOWERS AND THUNDERSTORMS AND SUBSEQUENT
CLOUD DEBRIS MAY LIMIT SEVERE THREAT IN THE NORTH THIS
AFTERNOON...BUT COULD SEE CONVECTION INITIATE ON BOUNDARY ACROSS THE
CENTRAL PART OF FORECAST AREA. BOUNDARY MAY BE ENHANCED AS THE
SOUTHERN PART OF THE FORECAST AREA WILL SEE MORE SUN.
UPDATE ISSUED AT 735 AM EDT WED SEP 26 2012
UPDATED THE FORECAST TO REFLECT CURRENT CONDITIONS AND MODEL TRENDS.
THE 06 GMT NAM BUFFER SOUNDING IS NOT QUITE AS UNSTABLE AS THE
PREVIOUS RUN. WILL STICK WITH THE STRONG THUNDERSTORM WORDING IN THE
HWO VERSUS SEVERE. THERE IS STILL QUITE A BIT OF UNCERTAINTY AS TO
EXACTLY WHERE THE THUNDERSTORMS WILL FIRE UP THIS AFTERNOON...HOWEVER
STILL THE THE BEST CHANCES WOULD BE NEAR THE MOUNTAIN PARKWAY. ONCE
THEY FIRE UP...THEN A LOT WILL DEPEND ON THE OUTFLOW BOUNDARIES. THE
JUICIEST AIR IS STILL IN THE NORTHERN PORTION OF EASTERN KENTUCKY. THE
REST OF THE FORECAST IS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 259 AM EDT WED SEP 26 2012
THE MODELS ARE IN GOOD GENERAL AGREEMENT WITH THE GENERAL PATTERN
THROUGH THURSDAY WITH THE MAIN FEATURE BEING A SHORT WAVE MOVING INTO
THE AREA FROM THE NORTHWEST WHICH WILL BE PUSHING THE FRONTS SOUTH
OVER THE NEXT TWO DAYS. THERE ARE REALLY TWO FRONTAL BOUNDARIES THAT
WE ARE DEALING WITH. THIS AFTERNOON...THERE WILL BE WEAK FRONT
GENERALLY RUNNING ALONG I 64. AS THIS FRONT IS PUSHES SOUTH IS WILL
FALL APART AND FRONTALYSE. ON THURSDAY A SECOND BOUNDARY WILL PUSH
SOUTH INTO EASTERN KENTUCKY AND ONCE AGAIN WILL FALL APART AS IT
DOES. WITH THESE WEAK BOUNDARIES IN THE MIX...THE WEATHER WILL STAY
UNSETTLED. WITH PERIODS OF SHOWERS AND THUNDERSTORMS.
THE BIG CHALLENGE FOR TODAY IS THE INSTABILITY THAT WILL BE OVER THE
AREA. AT 4PM...THE NAM BUFFER SOUNDING OVER JACKSON IS SHOWING TOTAL
TOTALS OF 55 AND A LIFTED INDEX OF -7. THE CAPE...WHICH MEASURES THE
POTENTIAL ENERGY OF THE SYSTEM IS AN IMPRESSIVE 2381 JOULES. ALL OF
THESE PARAMETERS WOULD BE INDICATIVE OF A GOOD POTENTIAL FOR SEVERE
WEATHER. ONE OF THE COMPLICATING FACTORS IS ALL OF THE DEBRIS THAT IS
LEFT OVER FROM THE MCS ACTIVITY THAT HAS OCCURRED OVER NIGHT. THE
RADAR IS SHOWING ANOTHER LINE OF STORMS WHICH SHOULD BE MOVING INTO
THE BLUEGRASS AROUND 53O AM THIS MORNING. THIS DEBRIS WILL RETARD THE
HEATING AND LESSEN THE INSTABILITY. AREAS JUST SOUTH OF THE MOUNTAIN
PARKWAY WOULD BE THE MOST LIKELY TO SEE THE STRONGER STORMS THIS
AFTERNOON. THIS IS BECAUSE THEY WILL BE CLOSE TO THE FORCING AND ALSO
HAVE SUFFICIENT INSTABILITY. AREAS FURTHER SOUTH LACK THE FORCING.
SINCE THERE IS NOT MUCH TURNING IN THE WINDS...THE BIGGEST THREAT
THIS AFTERNOON WILL BE FOR DAMAGING WINDS. THE THREAT FOR SEVERE HAIL
WOULD BE PRETTY LOW.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 259 AM EDT WED SEP 26 2012
THE LONG TERM MODELS START OFF IN DECENT AGREEMENT...WITH BOTH THE
GFS AND ECMWF DRAPING A SLUGGISH FRONTAL BOUNDARY ALONG THE OHIO
RIVER TO BEGIN THE PERIOD. BOTH MODELS THEN HAVE THIS BOUNDARY
LINGERING ACROSS THE AREA AS IT DRIFTS SLOWLY SOUTHWARD ON FRIDAY
AND SATURDAY. BY SATURDAY NIGHT...THE BOUNDARY FINALLY MAKES IT
SOUTH OF THE AREA. THERE WILL BE A GOOD CHANCE OF SHOWERS AND
THUNDERSTORMS WHILE THE FRONT MOVES ACROSS EASTERN AND CENTRAL
KENTUCKY...WITH THE MOST ACTIVE PERIODS OCCURRING DURING DAYTIME
HEATING. MOIST NORTH TO NORTHWEST WILL THEN BECOME ESTABLISHED
ACROSS THE REGION SATURDAY AND SATURDAY NIGHT...AS THE FRONT MOVES
INTO THE TENNESSEE VALLEY. AN AREA OF CANADIAN HIGH PRESSURE WILL
FINALLY BECOME ESTABLISHED OVER THE EASTERN CONUS FROM SUNDAY
ONWARD. THIS AIR MASS WILL BRING ANOTHER SHOT OF FALL LIKE WEATHER
TO THE REGION...WITH DAYTIME HIGHS TOPPING OUT IN THE LOW 70S AND
NIGHT TIME LOWS DIPPING INTO THE LOWER 50S FOR MOST OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 150 PM EDT WED SEP 26 2012
QUASI STATIONARY FRONTAL BOUNDARY REMAINS FROM LAKE ONTARIO TO
NORTHERN ILLINOIS. THERE IS ALSO A WEAK BOUNDARY FURTHER SOUTH WHICH
IS ACROSS NORTHERN KY. CONVECTION CURRENTLY OVER SOUTHERN INDIANA
MAY AFFECT THE FAR NORTHERN PART OF THE FORECAST AREA DURING THE LATE
AFTERNOON WHILE CONVECTION OVER SOUTHERN ILLINOIS MAY AFFECT THE
NORTHERN PART OF THE FORECAST AREA THIS EVENING.
CONVECTION OVER THE CENTRAL AND SOUTHERN PART OF THE FORECAST
AREA...WHILE POSSIBLE TONIGHT...IS NOT LIKELY...AND AT THIS TIME WILL
LEAVE ALL MENTION OF THUNDER OUT OF TAF SITES. CLOUDS WILL BE ON THE
INCREASE DURING THE FORECAST PERIOD...BUT ANY CEILINGS AT THE TAF
SITES ARE EXPECTED TO REMAIN VFR. SOME MVFR CEILINGS WILL BE POSSIBLE
THIS AFTERNOON AND TONIGHT IN THE NORTHERN PART OF THE FORECAST AREA.
CLOUDS WILL ALSO LIMIT FOG TONIGHT...WITH AREAS OUTSIDE OF PRECIPITATION
HAVING MOSTLY VFR VISIBILITY THROUGH THE FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...JJ
LONG TERM....AR
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 PM EDT WED SEP 26 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 450 AM EDT WED SEP 26 2012
WV IMAGERY AND RUC ANALYSIS SHOWING UPPER TROUGH STRETCHING SW OVER
THE UPPER GREAT LKS FROM NRN QUEBEC. SHORTWAVE CURRENTLY ROTATING
THROUGH THE AXIS OF THE TROUGH OVER WRN LK SUPERIOR. AREA OF CLOUDS
ASSOCIATED WITH THIS SHORTWAVE HAVE BEEN STRUGGLING TO MOVE ACROSS
WRN LK SUPERIOR...BUT ARE FINALLY STARTING TO MOVE OVER LAND.
FARTHER EAST...A FEW AREAS OF LK ENHANCED RAIN SHOWERS HAVE BEEN
ONGOING OVER THE MAINLY NW FLOW ACROSS EASTERN LK SUPERIOR. THESE
HAVE BEEN DRIFTING MORE TO THE S OVER TIME AS 8Z KMQT VAD WIND
PROFILE SHOWING MORE NNW WINDS ALOFT. THESE SHOWERS LINE UP WELL
WITH MODEL INDICATED POCKET OF DEEPEST MOISTURE.
THE SHOWERS AND CLOUDS ASSOCIATED WITH THE SHORTWAVE WILL BE THE
MAIN CONCERNS FOR THE SHORT TERM PERIOD. EXPECT THE SHOWERS TO
CONTINUE TO SLIDE TO THE SSE UNDER THE NNW FLOW ALOFT THROUGH THE
MORNING HOURS AND LARGELY BE FOCUSED OVER NCNTRL UPPER MI. WITH THE
SHORTWAVE BRUSHING THE NE HALF OF THE CWA...COULD SEE AN INCREASE IN
INTENSITY FOR A WHILE THIS EARLY MORNING...BEFORE THE SHORTWAVE
QUICKLY DIVES SE OF THE CWA. AS THIS OCCURS...EXPECT THE MOISTURE TO
EXIT AND BRING AN END TO THE SHOWERS AS H500 HEIGHTS ARE ON THE
RISE. AS FOR CLOUDS...THERE SHOULD BE ENOUGH LLVL MOISTURE TO
PRODUCE A MOSTLY CLOUDY SKY NEAR LK SUPERIOR THIS MORNING AND THEN
SPREAD ACROSS MUCH OF THE REST OF THE CWA UNDER DIURNAL HEATING BY
MID DAY. THEN THE PREVIOUSLY MENTIONED DRYING WILL BEGIN TO TAKE
HOLD IN THE AFTN AND DIMINISH THE CLOUDS FROM NW TO SE ACROSS THE
CWA...WITH THE CLOUDS HOLDING ON THE LONGEST OVER ERN UPPER MI
/TOWARDS EARLY EVENING/. H850 TEMPS A DEGREE OR TWO COOLER TODAY
THAN YESTERDAY...SO EXPECT A SLIGHTLY COOLER DAY AND HIGHS IN THE
50S.
AS HAS BEEN DISCUSED OVER THE LAST SEVERAL SHIFTS...APPEARS TO BE A
GOOD FROST/FREEZE OVER MUCH OF UPPER MI TONIGHT. HIGH PRESSURE
CURRENTLY OVER SRN MANITOBA WILL SLIDE OVERHEAD AND PRODUCE CLEAR
SKIES OVER ALL BUT FAR EASTERN UPPER MI /LINGERING LK EFFECT
CLOUDS/. PWATS AROUND 50 PERCENT OF NORMAL AND CLEAR SKIES WILL
PROMOTE RADIATIONAL COOLING AND EXPECT LOWS IN THE MID 20S TO LOWER
30S OVER MOST INTERIOR LOCATIONS. UNDER SIMILAR CONDITIONS THIS
MORNING...MANY LOCATIONS IN THE INTERIOR WEST FELL INTO THE UPPER
20S. THEREFORE...EXPECT ANOTHER DECENT FROST/FREEZE ACROSS THE
AREA...WHICH COULD EVEN EFFECT AREAS CLOSE TO THE GREAT LKS
SHORELINES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 450 AM EDT WED SEP 26 2012
TEHRE IS A FAIR AMOUNT OF DISAGREEMENT IN MEDIUM RANGE GUIDANCE FOR
THE NEXT 7 DAYS. CURRENT TROF OVER ERN CANADA INTO THE GREAT LAKES
WILL LIFT OUT OVER THE NEXT FEW DAYS. HOWEVER...ANOTHER SHORTWAVE
WILL BE DROPPING SE AS THE TROF LIFTS OUT LATE WEEK. MODELS HAVE
BEEN STRUGGLING WITH EXACTLY WHAT HAPPENS WITH THAT PIECE OF ENERGY.
MORE ON THAT LATER. FORTUNATELY...THE ARRAY OF SOLUTIONS DOESN`T
IMPACT THE PCPN FCST. THE DIFFERENCES IN GUIDANCE INTO/THRU THE
WEEKEND TRANSITION TO LARGER DIFFERENCES DURING THE EARLY PART OF
NEXT WEEK AS GFS/ECMWF HAVE BEEN VARYING BTWN NW AND WSW FLOW INTO
THE UPPER GREAT LAKES. OVERALL...THIS WILL BE A DRY PATTERN FOR
UPPER MI. TEMP FCST IS SOMEWHAT UNCERTAIN GIVEN THE MODEL
DISCREPENCIES...BUT TREND WILL BE TOWARD ABOVE NORMAL IN GENERAL.
BEGINNING THU...ALTHOUGH ERN TROF WILL BE IN THE PROCESS OF LIFTING
OUT...A SHORTWAVE WILL BE DROPPING SE TOWARD FAR NRN ONTARIO. THIS
WILL RESULT IN A MODEST WAA PATTERN ACROSS THE AREA THU. MODELS SHOW
A DRY COLUMN...SO PCPN IS NOT A CONCERN WITH THE WAA. IN FACT...THE
DAY WILL LIKELY BE MOSTLY SUNNY GIVEN THE DEGREE OF DRY AIR. WAA
WILL HELP TEMPS RISE INTO THE UPPER 50S/LWR 60S PER MIXING TO AROUND
850MB ON FCST SOUNDINGS.
AS SHORTWAVE CONTINUES SE...PASSING OVER THE SRN TIP OF JAMES BAY
FRI...A VERY WEAK SFC TROF WILL SINK S ACROSS THE AREA. WITH MAIN
DYNAMICS PASSING WELL TO THE NE AND A DRY AIR MASS REMAINING OVER
THE AREA...PCPN IS NOT AN ISSUE. 850MB TEMPS TO START THE DAY FRI
ARE 4-6C HIGHER THAN THE PREVIOUS DAY. MIXING TO AROUND 850MB YIELDS
MAX TEMPS AROUND 70F. LOOKS LIKE THERE MAY BE A FAIR AMOUNT OF MID
CLOUD FOR AT LEAST A PORTION OF THE DAY...SO HELD TEMPS GENERALLY TO
THE MID/UPPER 60S.
SHORTWAVE PASSING NEAR THE SRN TIP OF JAMES BAY FRI GETS LEFT BEHIND
OVER THE WEEKEND AS STRONG HEIGHT RISES OCCUR OVER SE CANADA IN THE
WAKE OF DEPARTING ERN TROF. AS THE SYSTEM BECOMES A BROADENING
MIDLEVEL LOW...THE HEIGHT RISES TO THE N END UP PUSHING SYSTEM S OR
SW. 00Z MODEL AGREEMENT IS NOT BAD WITH THE RANGE OF SOLUTIONS
SHOWING THE CENTER OF THE MID LEVEL LOW SOMEWHERE BTWN WRN LWR MI
(GLOBAL GEM) AND NW PA/WRN NY SUN (GFS). AT THIS POINT...THE
DIFFERENCES SEEN IN THE 00Z MODEL RUNS AND IN PREVIOUS RUNS WON`T
IMPACT FCST SIGNIFICANTLY. GIVEN THE DRY ORIGINATION OF THE SYSTEM
AND THE TIME IT WILL TAKE TO FULLY ENTRAIN DEEPER MOISTURE OFF THE
ATLANTIC...PCPN SHOULD NOT BE A CONCERN HERE. LOCATION OF THE MID
LEVEL LOW WILL HAVE MORE OF AN AFFECT ON TEMPS. THE FARTHER W GLOBAL
GEM SOLUTION WOULD BRING A COOLER AIR MASS INTO THE AREA FROM THE NE
FOR SUN (850MB TEMPS 3C E TO 5C W) WHILE THE FARTHER E GFS SOLUTION
WOULD MAINTAIN WARMER WEATHER THRU SUN (850MB TEMPS 4C E TO 10C W).
GIVEN THE VARYING SOLUTIONS OF RECENT DAYS...WILL STAY CLOSE TO A
BIAS CORRECTED CONSENSUS FCST UNTIL LOCATION OF MID LEVEL LOW IS
BETTER AGREED UPON. END RESULT IS HIGHS MAINLY IN THE 60S THIS
WEEKEND.
ECWMF/GFS HAVE STRUGGLED WITH THE PATTERN EARLY NEXT WEEK AS BOTH
MODELS HAVE VARIED FROM HAVING A RIDGE IN THE PACIFIC NW AND NW FLOW
INTO THE UPPER LAKES TO A TROF IN THE PACIFIC NW AND WSW FLOW INTO
THE UPPER LAKES. FOR THE MOMENT...THE 00Z RUNS FAVOR NW FLOW INTO
THE UPPER LAKES WHICH RESULTS IN A SHORTWAVE/COLD FRONT PASSING MON
AND PERHAPS ANOTHER LATE TUE. ONLY INCLUDED A SCHC OF -SHRA MON WITH
FIRST SHORTWAVE. TEMPS MON/TUE SHOULD BE MOSTLY IN THE 60S TO AROUND
70F.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 132 PM EDT WED SEP 26 2012
SHORTWAVE AND GOOD AREA OF LOW LEVEL MOISTURE ARE BEGINNING TO MOVE
SOUTHEAST OUT OF THE CWA. SOME LINGERING LAKE ENHANCED VCSH NEAR
KSAW WILL BEGIN TO DIMINISH AS BEST MOISTURE MOVES AWAY FROM TAF
SITE. STRONG HIGH PRESSURE RIDGING WILL CONTINUE MOVING IN FROM THE
WEST...KEEPING WINDS CALM AND DRY CONDITIONS. THE MAIN CONCERN
DURING TAF PERIOD THEN IS THE EXTENSIVE DIURNAL CU THAT HAS SET UP
ACROSS UPPER MI AND NORTHERN MN. THOUGH FORECAST MODELS HAD ALL TAF
SITES CLEARING OUT DURING THE AFTERNOON...IT LOOKS AS THOUGH THE
CLOUDS WILL PERSIST UNTIL DAYTIME HEATING IS LOST. DO NOT EXPECT
ANYTHING BELOW VFR. SKIES WILL CLEAR OUT OVERNIGHT...AND WITH HIGH
PRESSURE DIRECTLY OVERHEAD TOMORROW...EXPECT LIGHT WINDS AND SUNNY
SKIES THOUGH THE REMAINDER OF THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 AM EDT WED SEP 26 2012
HIGH PRES/WEAK PRES GRADIENT WILL GENERALLY DOMINATE FOR THE REST
OF THIS WEEK AND INTO THE WEEKEND. THIS WILL RESULT IN WINDS
UNDER 20KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...JMW
MARINE...SRF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
242 PM EDT WED SEP 26 2012
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL ACROSS THE REGION TODAY AS A
COLD FRONT SLIDES SOUTHEAST THROUGH THE AREA. BEHIND THE COLD
FRONT LATE TONIGHT...COOL AND DRY CONDITIONS WILL PREVAIL FOR
THURSDAY AS HIGH PRESSURE BUILDS INTO THE AREA. RAIN CHANCES
WILL ONCE AGAIN INCREASE TOWARDS THE END OF THE WEEK AS THE NEXT
SERIES OF DISTURBANCES IMPACT THE FORECAST REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...
MINOR CHANGES. AGAIN BACKED OFF ON THE PRECIP ONSET. SPRINKLES NOW
IN THE SW CWA BUT THIS CONTINUES TO DIE. MORE WAVES WILL DO BETTER
THIS AFTERNOON BRINGING RAINFALL TO THE ENTIRE CWA AHEAD OF A COLD
FRONT. TSTORM CHANCES CONTINUE TO LOOK LOW. SKIES SHOULD STAY
CLOUDY. SMALL NARROW CAPE WITH NO MID LEVEL DRYING. LEFT ISOLATED
T. BEST CHC WILL BE IN THE FAR S WHERE TEMPERATURES WILL BE
WARMEST AND THE FRONT WILL TAKE THE LONGEST TO GET TO.
640 AM UPDATE...
REGIONAL RADARS SHOWING AN AREA OF SHWRS/EMBEDDED THUNDER LIFTING
NORTHEAST TOWARDS OUR AREA FROM WESTERN PA. HIGH-RES MODELS TO
INCLUDE THE HRRR AND WRF-ARW SUGGEST THIS ACTIVITY WILL WEAKEN
WITH FURTHER EASTWARD PROGRESS. DESPITE THIS HOWEVER...HAVE
INCREASED POPS ACROSS THE SOUTHWEST FOR THE NEXT FEW HRS IN CASE
ACTIVITY HOLDS TOGETHER. BEYOND THIS...MAIN ACTIVITY IS EXPECTED
TO BE ALONG THE COLD FRONT AS IT SHIFTS SOUTH OVER OUR REGION
(DETAILS HIGHLIGHTED BELOW). IN ADDITION TO POP GRID
ADJUSTMENTS...MINOR TWEAKS ALSO MADE TO HOURLY TEMP AND DEWPOINT
GRIDS.
PREVIOUS NEAR TERM DISCUSSION...
EARLY MORNING RADAR IMAGERY SHOWING THE FIRST ROUND OF SHWRS
ASSOCIATED WITH SOUTHERN STREAM SHORTWAVE ENERGY AND WARM AIR
ADVECTION NOW WORKING THROUGH THE FCST AREA. TRAILING EDGE OF
SHWRS MOVING INTO THE CENTRAL FINGER LAKES THIS HR WITH UPSTREAM
RADAR TRENDS SUGGESTING WE/LL HAVE A FEW DRY HRS BEFORE THE NEXT
ROUND OF SHWRS DEVELOPS ALONG THE SOUTHWARD SAGGING COLD FRONT
LATER THIS MORNING/EARLY AFTERNOON. EXPANDING OUT...WATER VAPOR
IMAGERY SHOWING THE NORTHERN STREAM SHORTWAVE DIGGING SOUTHEAST
ACROSS THE WESTERN GREAT LAKES WITH MAIN STATIONARY BOUNDARY
ANALYZED FROM CENTRAL MI NORTHEAST INTO SOUTHERN ONTARIO AND
WESTERN QUEBEC. THIS FRONT IS FCST TO BEGIN SLIDING SOUTHEAST WITH
TIME AS MAIN NORTHERN STREAM SHORTWAVE ENERGY NOW ACROSS THE
WESTERN LAKES APPROACHES...SETTING THE STAGE FOR THE NEXT ROUND OF
SHWRS AND THE POSSIBILITY OF A THUNDERSTORM OR TWO LATER TODAY.
AS HAS BEEN HIGHLIGHTED IN RECENT FCST DISCUSSIONS...MUCH
UNCERTAINTY STILL REMAINS WITH RESPECT TO CONVECTIVE COVERAGE
LATER TODAY. MAIN CONCERNS ARE A RESULT OF MIXED SIGNALS FROM
VARIOUS SHORT TERM MODELS TO INCLUDE BOTH THE GFS AND WRF. THE
LATTER IN RECENT WEEKS HAS PERFORMED VERY POORLY WITH RESPECT TO
INSTABILITY FCST AND TODAY APPEARS TO BE ANOTHER REPEAT
PERFORMANCE AS THE LATEST RUN SUGGESTS UP TO 1000 JOULES OF MLCAPE
DEVELOPMENT LATER TODAY. THE GFS ON THE OTHER HAND ONLY SUGGESTS A
FEW HUNDRED JOULES AT BEST WHICH APPEARS MORE LIKELY CONSIDERING
ATMOSPHERE AHEAD OF THE FRONT WILL LIKELY BE "JUNKED UP" AS A
RESULT OF THIS MORNING/S SHWR ACTIVITY. THAT SAID...HAVE
MAINTAINED AN ISOLATED THUNDER MENTION FROM MAINLY THE STATE LINE
SOUTH AS BEST INSTABILITY GENERATION WILL BE ACROSS THESE AREAS.
DESPITE FAVORABLE WIND FIELDS ALOFT...THE LACK OF APPRECIABLE
INSTABILITY WILL KEEP ANY DEVELOPING CONVECTION FROM APPROACHING
SEVERE LIMITS.
RAIN TO QUICKLY COME TO AN END FROM NORTH TO SOUTH AFTER 00Z.
FOLLOWING THE DEPARTURE OF THE FRONT...VERY DRY AIR WILL QUICKLY
MOVE INTO THE AREA WHICH SHOULD PREVENT ANY LAKE RESPONSE DESPITE
LAKE/H85 TEMP DIFFERENCES APPROACHING 20C BY 12Z THU. ADDITIONALLY
LOW-LEVEL WIND PROFILES SUGGEST AMPLE AMOUNTS OF SHEAR WITHIN THE
INVERSION LAYER WHICH WILL ALSO BE UNFAVORABLE LAKE EFFECT RAIN
SHWRS.
TEMPS TODAY SHOULD WARM INTO THE UPPER 60S TO LOWER 70S AS WARM
AIR ADVECTION PERSISTS AHEAD OF THE COLD FRONT. TOOK A MET/MAV
BLEND AS RESIDUAL CLOUD COVER MAY KEEP TEMPS FROM WARMING TO THE
HIGHER VALUES AS SUGGESTED BY THE MET. BY TONIGHT...WITH CLEARING
SKIES ALOFT AND TEMPS EASILY FALLING INTO THE MIDDLE TO UPPER
40S...PATCHY VALLEY FOG DEVELOPMENT APPEARS LIKELY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
DRY AND COOLER CONDITIONS ARE EXPECTED ON THURSDAY AS HIGH
PRESSURE TEMPORARILY MOVES INTO THE REGION. WITH COLD AIR
ADVECTION PREVAILING OVER THE AREA...EXPECT HIGH TEMPS TO ONLY
REACH THE LOWER TO MIDDLE 60S.
FCST BECOMES A BIT MORE COMPLICATED BY THU NGT/EARLY FRI AS
SHORTWAVE ENERGY RIDES EAST ALONG A STALLED FRONT TO OUR SOUTH.
SHORT TERM MODELS INCREASE RAIN CHANCES DURING THIS PERIOD MAINLY
FOR AREAS SOUTH OF THE STATE LINE AS LINGERING HIGH PRESSURE AND
STRONG SFC RIDGING CONTINUE TO SUPPLY DRY AIR TO THE NORTHERN CWA.
HAVE SCALED PRECIP MENTION FURTHER SOUTH AS A RESULT OF THE SFC
RIDGING WHILE ALSO MAINTAINING A CHC MENTION FOR THE SOUTHERN
ZONES.
WEAK SFC LOW TO BEGIN WORKING UP THE MID-ATLANTIC COAST ON FRI
WHICH COMBINED WITH INCREASING DPVA ALOFT FROM APPROACHING POLAR
VORTEX ACROSS CENTRAL ONTARIO...WILL KEEP THE CHC FOR SHWRS
ACROSS THE ENTIRE REGION BOTH FRI AND FRI NGT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED
WITH A CUTOFF UPPER LEVEL LOW DROPPING SOUTH INTO THE LOWER LAKES
SATURDAY AND SUNDAY BEFORE LIFTING OUT BY MONDAY NIGHT. THIS WILL
RESULT IN A PROLONGED PERIOD OF UNSETTLED WEATHER WITH CHC POPS
FOR SHOWERS. CONDITIONS WILL IMPROVE TUESDAY AND WEDNESDAY DUE TO
RISING UPPER LEVEL HEIGHTS AND SFC HIGH PRES IN THE MID ATLANTIC.
THIS SETUP WILL PROVIDE MAINLY DRY WEATHER ALONG WITH MODERATING
TEMPERATURES.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
A COLD FRONT ACROSS NEARBY SOUTHERN ONTARIO WILL GRADUALLY DROP
SOUTH THROUGH THE REGION OVERNIGHT. FRONTAL TIMING WILL BE DURING
THE EVENING HOURS AT KRME/KSYR/KTIH AND TOWARD MIDNIGHT AT
KBGM/KELM AND NEAR 06Z AT KAVP. IN GENERAL WIDESPREAD MVFR/LOW
MVFR CONDITIONS WILL PERSIST UNTIL LATE TONIGHT DUE TO CIGS. LIGHT
SHOWERS ARE POSSIBLE AT KBGM/KAVP THROUGH LATE AFTERNOON AND AGAIN
AT ALL TAF SITES AROUND FROPA. CONDITIONS WILL IMPROVE TO VFR OVER
THE NRN TERMINALS AROUND 09Z AND MID MORNING FOR THE REMAINDER OF SITES.
SOUTHWEST WINDS AROUND 5-8 KNOTS BECOMING NORTHWEST AFTER FROPA
AROUND 5 KNOTS THEN NORTHERLY WINDS ON THURSDAY AROUND 10 KNOTS.
OUTLOOK...
FRI THROUGH SAT...GENERALLY VFR...BUT MVFR POSSIBLE IN SHOWERS AT
KAVP.
SUNDAY THROUGH MONDAY...MVFR SHOWERS POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/TAC
NEAR TERM...CMG/TAC
SHORT TERM...CMG
LONG TERM...RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
210 PM EDT WED SEP 26 2012
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PREVAIL ACROSS THE REGION TODAY AS A
COLD FRONT SLIDES SOUTHEAST THROUGH THE AREA. BEHIND THE COLD
FRONT LATE TONIGHT...COOL AND DRY CONDITIONS WILL PREVAIL FOR
THURSDAY AS HIGH PRESSURE BUILDS INTO THE AREA. RAIN CHANCES
WILL ONCE AGAIN INCREASE TOWARDS THE END OF THE WEEK AS THE NEXT
SERIES OF DISTURBANCES IMPACT THE FORECAST REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE...
MINOR CHANGES. AGAIN BACKED OFF ON THE PRECIP ONSET. SPRINKLES NOW
IN THE SW CWA BUT THIS CONTINUES TO DIE. MORE WAVES WILL DO BETTER
THIS AFTERNOON BRINGING RAINFALL TO THE ENTIRE CWA AHEAD OF A COLD
FRONT. TSTORM CHANCES CONTINUE TO LOOK LOW. SKIES SHOULD STAY
CLOUDY. SMALL NARROW CAPE WITH NO MID LEVEL DRYING. LEFT ISOLATED
T. BEST CHC WILL BE IN THE FAR S WHERE TEMPERATURES WILL BE
WARMEST AND THE FRONT WILL TAKE THE LONGEST TO GET TO.
640 AM UPDATE...
REGIONAL RADARS SHOWING AN AREA OF SHWRS/EMBEDDED THUNDER LIFTING
NORTHEAST TOWARDS OUR AREA FROM WESTERN PA. HIGH-RES MODELS TO
INCLUDE THE HRRR AND WRF-ARW SUGGEST THIS ACTIVITY WILL WEAKEN
WITH FURTHER EASTWARD PROGRESS. DESPITE THIS HOWEVER...HAVE
INCREASED POPS ACROSS THE SOUTHWEST FOR THE NEXT FEW HRS IN CASE
ACTIVITY HOLDS TOGETHER. BEYOND THIS...MAIN ACTIVITY IS EXPECTED
TO BE ALONG THE COLD FRONT AS IT SHIFTS SOUTH OVER OUR REGION
(DETAILS HIGHLIGHTED BELOW). IN ADDITION TO POP GRID
ADJUSTMENTS...MINOR TWEAKS ALSO MADE TO HOURLY TEMP AND DEWPOINT
GRIDS.
PREVIOUS NEAR TERM DISCUSSION...
EARLY MORNING RADAR IMAGERY SHOWING THE FIRST ROUND OF SHWRS
ASSOCIATED WITH SOUTHERN STREAM SHORTWAVE ENERGY AND WARM AIR
ADVECTION NOW WORKING THROUGH THE FCST AREA. TRAILING EDGE OF
SHWRS MOVING INTO THE CENTRAL FINGER LAKES THIS HR WITH UPSTREAM
RADAR TRENDS SUGGESTING WE/LL HAVE A FEW DRY HRS BEFORE THE NEXT
ROUND OF SHWRS DEVELOPS ALONG THE SOUTHWARD SAGGING COLD FRONT
LATER THIS MORNING/EARLY AFTERNOON. EXPANDING OUT...WATER VAPOR
IMAGERY SHOWING THE NORTHERN STREAM SHORTWAVE DIGGING SOUTHEAST
ACROSS THE WESTERN GREAT LAKES WITH MAIN STATIONARY BOUNDARY
ANALYZED FROM CENTRAL MI NORTHEAST INTO SOUTHERN ONTARIO AND
WESTERN QUEBEC. THIS FRONT IS FCST TO BEGIN SLIDING SOUTHEAST WITH
TIME AS MAIN NORTHERN STREAM SHORTWAVE ENERGY NOW ACROSS THE
WESTERN LAKES APPROACHES...SETTING THE STAGE FOR THE NEXT ROUND OF
SHWRS AND THE POSSIBILITY OF A THUNDERSTORM OR TWO LATER TODAY.
AS HAS BEEN HIGHLIGHTED IN RECENT FCST DISCUSSIONS...MUCH
UNCERTAINTY STILL REMAINS WITH RESPECT TO CONVECTIVE COVERAGE
LATER TODAY. MAIN CONCERNS ARE A RESULT OF MIXED SIGNALS FROM
VARIOUS SHORT TERM MODELS TO INCLUDE BOTH THE GFS AND WRF. THE
LATTER IN RECENT WEEKS HAS PERFORMED VERY POORLY WITH RESPECT TO
INSTABILITY FCST AND TODAY APPEARS TO BE ANOTHER REPEAT
PERFORMANCE AS THE LATEST RUN SUGGESTS UP TO 1000 JOULES OF MLCAPE
DEVELOPMENT LATER TODAY. THE GFS ON THE OTHER HAND ONLY SUGGESTS A
FEW HUNDRED JOULES AT BEST WHICH APPEARS MORE LIKELY CONSIDERING
ATMOSPHERE AHEAD OF THE FRONT WILL LIKELY BE "JUNKED UP" AS A
RESULT OF THIS MORNING/S SHWR ACTIVITY. THAT SAID...HAVE
MAINTAINED AN ISOLATED THUNDER MENTION FROM MAINLY THE STATE LINE
SOUTH AS BEST INSTABILITY GENERATION WILL BE ACROSS THESE AREAS.
DESPITE FAVORABLE WIND FIELDS ALOFT...THE LACK OF APPRECIABLE
INSTABILITY WILL KEEP ANY DEVELOPING CONVECTION FROM APPROACHING
SEVERE LIMITS.
RAIN TO QUICKLY COME TO AN END FROM NORTH TO SOUTH AFTER 00Z.
FOLLOWING THE DEPARTURE OF THE FRONT...VERY DRY AIR WILL QUICKLY
MOVE INTO THE AREA WHICH SHOULD PREVENT ANY LAKE RESPONSE DESPITE
LAKE/H85 TEMP DIFFERENCES APPROACHING 20C BY 12Z THU. ADDITIONALLY
LOW-LEVEL WIND PROFILES SUGGEST AMPLE AMOUNTS OF SHEAR WITHIN THE
INVERSION LAYER WHICH WILL ALSO BE UNFAVORABLE LAKE EFFECT RAIN
SHWRS.
TEMPS TODAY SHOULD WARM INTO THE UPPER 60S TO LOWER 70S AS WARM
AIR ADVECTION PERSISTS AHEAD OF THE COLD FRONT. TOOK A MET/MAV
BLEND AS RESIDUAL CLOUD COVER MAY KEEP TEMPS FROM WARMING TO THE
HIGHER VALUES AS SUGGESTED BY THE MET. BY TONIGHT...WITH CLEARING
SKIES ALOFT AND TEMPS EASILY FALLING INTO THE MIDDLE TO UPPER
40S...PATCHY VALLEY FOG DEVELOPMENT APPEARS LIKELY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
DRY AND COOLER CONDITIONS ARE EXPECTED ON THURSDAY AS HIGH
PRESSURE TEMPORARILY MOVES INTO THE REGION. WITH COLD AIR
ADVECTION PREVAILING OVER THE AREA...EXPECT HIGH TEMPS TO ONLY
REACH THE LOWER TO MIDDLE 60S.
FCST BECOMES A BIT MORE COMPLICATED BY THU NGT/EARLY FRI AS
SHORTWAVE ENERGY RIDES EAST ALONG A STALLED FRONT TO OUR SOUTH.
SHORT TERM MODELS INCREASE RAIN CHANCES DURING THIS PERIOD MAINLY
FOR AREAS SOUTH OF THE STATE LINE AS LINGERING HIGH PRESSURE AND
STRONG SFC RIDGING CONTINUE TO SUPPLY DRY AIR TO THE NORTHERN CWA.
HAVE SCALED PRECIP MENTION FURTHER SOUTH AS A RESULT OF THE SFC
RIDGING WHILE ALSO MAINTAINING A CHC MENTION FOR THE SOUTHERN
ZONES.
WEAK SFC LOW TO BEGIN WORKING UP THE MID-ATLANTIC COAST ON FRI
WHICH COMBINED WITH INCREASING DPVA ALOFT FROM APPROACHING POLAR
VORTEX ACROSS CENTRAL ONTARIO...WILL KEEP THE CHC FOR SHWRS
ACROSS THE ENTIRE REGION BOTH FRI AND FRI NGT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
430 AM UPDATE...
STALLED FRNTL BNDRY PRESENT TO THE SOUTH OF THE AREA WL BEGIN TO
PROGRESS NORTH AND EAST THRU THE WEEKEND AS A STRONG S/WV DROPS IN
ASSOC WITH UL TROF IN ERN CANADA...INDUCING SFC LOW DVLPMNT ALONG
THE MID-ATLANTIC COAST. THIS LOW WL RIDE ALONG THE FRONTAL
BNDRY...KEEPING UNSETTLED WX PRESENT THRU EARLY NEXT WEEK. MODELS
IN FAIRLY GOOD AGREEMENT WITH UA PATTERN THRU 00Z TUE THO THEY
DIFFER ON HOW FAR SOUTH AND HOW STRONG THE UL LOW WL BCM. GIVEN
THAT MODELS ARE CONSISTENT WITH EACH OTHER SEE NO REASON TO CHG
LONG TERM GRIDS AT THIS POINT WITH 30 POPS PRESENT SAT THRU MON IN
THE FORM OF SHOWERS. TEMPS WL BE RELATIVELY CLOSE TO NORMAL VALUES
THRU THE EXTNDD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A COLD FRONT ACROSS NEARBY SOUTHERN ONTARIO WILL GRADUALLY DROP
SOUTH THROUGH THE REGION OVERNIGHT. FRONTAL TIMING WILL BE DURING
THE EVENING HOURS AT KRME/KSYR/KTIH AND TOWARD MIDNIGHT AT
KBGM/KELM AND NEAR 06Z AT KAVP. IN GENERAL WIDESPREAD MVFR/LOW
MVFR CONDITIONS WILL PERSIST UNTIL LATE TONIGHT DUE TO CIGS. LIGHT
SHOWERS ARE POSSIBLE AT KBGM/KAVP THROUGH LATE AFTERNOON AND AGAIN
AT ALL TAF SITES AROUND FROPA. CONDITIONS WILL IMPROVE TO VFR OVER
THE NRN TERMINALS AROUND 09Z AND MID MORNING FOR THE REMAINDER OF SITES.
SOUTHWEST WINDS AROUND 5-8 KNOTS BECOMING NORTHWEST AFTER FROPA
AROUND 5 KNOTS THEN NORTHERLY WINDS ON THURSDAY AROUND 10 KNOTS.
OUTLOOK...
FRI THROUGH SAT...GENERALLY VFR...BUT MVFR POSSIBLE IN SHOWERS AT
KAVP.
SUNDAY THROUGH MONDAY...MVFR SHOWERS POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG/TAC
NEAR TERM...CMG/TAC
SHORT TERM...CMG
LONG TERM...PVN
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
338 PM EDT WED SEP 26 2012
.SYNOPSIS...
A SLOW MOVING FRONTAL BOUNDARY WILL GRADUALLY MOVE THROUGH THE
OHIO VALLEY THIS WEEK. SOUTH OF THE FRONT...SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO IMPACT THE REGION. HIGH PRESSURE
WILL BUILD IN ON SATURDAY...BUT AN UPPER LEVEL LOW PRESSURE
CENTER WILL PROVIDE A CHANCE OF SHOWERS ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
SOUTH OF A SLOWLY-MOVING COLD FRONT...THE CWA REMAINS ENTRENCHED
IN AN AREA OF DEEP MOISTURE AND MODERATE WEST-SOUTHWESTERLY FLOW
IN THE LOWER TO MID LEVELS. THE PRIMARY FORECAST FOCUS IS ON
CONVECTIVE CHANCES AND TIMING TONIGHT.
CONVECTION ONGOING ACROSS THE CWA APPEARS TO BE ASSOCIATED WITH A
WEAK VORTICITY CENTER OVER INDIANA...WITH THE NEW DEVELOPMENT
FIRING UP ON A BAND WELL OUT AHEAD OF IT. MEANWHILE...THE WSW-ENE
ORIENTED BAND OF SHOWERS (WITH EMBEDDED THUNDER) THROUGH CENTRAL
OHIO IS JUST AHEAD OF THE BOUNDARY. INSTABILITY HAS BUILT TO ABOUT 1000
J/KG IN NORTHERN KENTUCKY...AND IS GREATER FURTHER TO THE
SOUTHWEST. RUC13 INSTABILITY FORECASTS OF 2000-2500 J/KG ARE MUCH
TOO HIGH...GIVEN THE ERRONEOUS ADVECTION OF DEWPOINTS OVER 70
DEGREES INTO SW OHIO.
POPS ARE CATEGORICAL FOR THE FIRST FEW HOURS OF THE FORECAST...AS
THE CURRENT ACTIVITY WORKS ITS WAY THROUGH THE CWA. AFTER
THAT...MUCH OF THE CWA MAY SEE A BREAK FROM CONVECTIVE
POTENTIAL...IN THE WAKE OF THE AFTERNOON SYSTEM. WHERE INSTABILITY
IS GREATER IN THE SOUTH...ADDITIONAL DEVELOPMENT IS POSSIBLE.
GIVEN THE 40 KNOTS OF 0-3 KM SHEAR (WHICH IS ACTUALLY STRONGER
THAN THE 0-6 KM SHEAR)...SOME STORM ORGANIZATION AND A FEW STRONG
CELLS WILL BE POSSIBLE. WITHOUT A KEY TRIGGER OR MUCH
INSTABILITY...WIDESPREAD SEVERE WEATHER DOES NOT APPEAR POSSIBLE.
POPS WILL BE KEPT IN THE LIKELY CATEGORY FOR THE SOUTHEASTERN TWO
THIRDS OF THE CWA GOING INTO TONIGHT. HOWEVER...GIVEN THE LACK OF
PRECIPITATION BEHIND THE CURRENT INDIANA/OHIO SYSTEM...IT APPEARS
THAT THE ACTIVITY WILL BE SHOWERY AND NOT ALL OF IT WILL BE
CONVECTIVE. DEVELOPING STORMS IN SOUTHERN ILLINOIS MAY BE WHAT
ENDS UP PROVIDING A GREATER CHANCE OF PRECIPITATION LATER ON
TONIGHT.
THE HOLES IN THE CLOUD COVER ALLOWED THE SOUTHERN CWA TO APPROACH
80 DEGREES TODAY. GIVEN THE WARMER STARTING POINT...AND EXPECTED
MOIST AND CLOUDY ATMOSPHERE TONIGHT...MIN TEMPS IN THE SOUTH WERE
BUMPED UP A FEW DEGREES FROM THE PREVIOUS FORECAST. WITH THE FRONT
MOVING INTO THE AREA...AND COLD ADVECTION BEGINNING IN THE
NORTH...THE TEMPERATURE GRADIENT OVERNIGHT WILL BE SOMEWHAT TIGHT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
THE FRONTAL BOUNDARY WILL CONTINUE TO MAKE VERY SLOW PROGRESS TO
THE EAST ON THURSDAY...BUT ENOUGH PROGRESS TO BRING AN END TO ANY
SIGNIFICANT CHANCES OF PRECIPITATION. THE FRONT WILL ORIENT ITSELF
EAST-TO-WEST ACROSS KENTUCKY...AND STALL OUT THROUGH FRIDAY. THIS
MEANS THAT THE MOISTURE AND FORCING ASSOCIATED WITH THE FRONT WILL
BE VERY CLOSE TO THE SOUTHERN EDGE OF THE FORECAST AREA. THIS
WILL REQUIRE A CHANCE OF SHOWERS (WITH A POSSIBILITY OF
THUNDERSTORMS) IN THE SOUTHERN HALF OF THE CWA FOR THURSDAY...AND
THEN JUST THE SOUTHERN THIRD OF THE CWA ON FRIDAY. AS THE VARIOUS
MODELS (AND THEIR VARIOUS RUNS) CONTINUE TO STRUGGLE WITH TIMING
THE EMBEDDED DISTURBANCES IN THE QUICK LOWER-TO-MID-LEVEL
FLOW...IT REMAINS DIFFICULT TO PIN DOWN THE TIME OR PLACEMENT OF
ANY NORTHWARD-IMPINGING CONVECTIVE SYSTEMS THAT MAY IMPACT THE CWA
DURING THIS TIME FRAME.
MAX TEMPERATURES WERE ADJUSTED SLIGHTLY DOWN THROUGH THE END OF
THE WEEK...AS THE COLD ADVECTION BEHIND THE FRONT WILL KEEP TEMPS
FROM REACHING 70. THE TEMPERATURE GRADIENT WILL BE TIGHTER ON
THURSDAY...WITH THE FRONT STILL IN THE AREA. GUIDANCE AND MODEL
NUMBERS EXHIBITED LITTLE SPREAD...INCREASING CONFIDENCE IN THE
FORECAST.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODELS ARE IN CLOSE AGREEMENT THROUGH THE PERIOD. SAT AND SUN
FOCUSED ON TROUGH ACROSS THE AREA WITH DISTURBANCE ROTATING THRU.
TIMING OF THIS DISTURBANCE IS MAIN PROBLEM WITH GFS MORE SAT NIGHT
AND ECMWF MORE SUN. HAVE OPTED FOR SMALL POP ACROSS THE NORTH FOR
BOTH SCENARIOS FOR NOW. LATER FCST CAN PERHAPS HAVE BETTER HANDLE ON
TIMING. MON-WED WILL SEE RIDGING WITH WARMING THRU PERIOD.
SEASONABLY COOL MORNINGS WITH SEASONAL OR SLIGHTLY ABOVE NORMAL
DAYTIME HIGHS.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
TAFS REMAIN IN A CONFLUENT H5 FLOW...AS A H5 TROF DIGS FROM THE
WRN GREAT LAKES INTO THE ERN ONES. AT THE SFC...A CDFNT CONTINUES
ITS SLOW PROGRESSION SOUTH ACROSS THE OH VALLEY. THE OVERALL
PATTERN IS A SET UP FOR SCATTERED CONVECTION AFFECTING THE
TAFS...THE CONFIDENCE IS VERY LOW ON THE TIMING OF THE CONVECTION
AT THE TAF SITES. STEADIEST CONVECTION ATTM IS RUNNING FROM LAF-
AOH-MFD IN AN AREA OF LIFT OUT AHEAD OF THE FRONT. THE BETTER
INSTABILITY IS DEVELOPING ACROSS SRN OH IN KY HOWEVER.
FOR NOW COVERED THE POSSIBILITY OF CONVECTION WITH ONLY VCTS OR
VCSH. THINK THAT THE BETTER CHC OF TS IN IN THE SRN TAFS. AS THE
FNT PUSHES S OVERNIGHT WINDS WILL SHIFT TO A NLY COMPONENT AND THE
CHC OF PCPN SHOULD END IN THE NRN TAFS. BROUGHT SOME MVFR CIGS IN
POST FRONTAL. THE FRONT IS SLOW TO MAKE ITS WAY S TOMORROW...SO
THERE COULD BE A LINGERING CHC OF SHRA AT CVG/LUK. AFT 12Z...CIGS
WILL BE SLOW TO RISE TO VFR.
.OUTLOOK...MVFR CONDITIONS POSSIBLE SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...PADGETT
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
142 PM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT OVER THE OHIO VALLEY MOVES EAST TODAY AND TONIGHT AND
STALLS FROM THE MID ATLANTIC TO THE CENTRAL PLAINS ON THURSDAY.
THIS FRONT WILL GRADUALLY DRIFT INTO THE SOUTHEAST UNITED STATES ON
SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM EDT WEDNESDAY...
THE TREND FOR A SLOWER AND FARTHER NORTH DEVELOP OF AFTERNOON
SHOWERS AND STORMS CONTINUES. HAVE CONFINED THE CHANCES TO
PRIMARILY NORTHERN GREENBRIER AND BATH COUNTIES THIS AFTERNOON
BASED UPON THE LATEST UPSTREAM RADAR TRENDS AND LACK OF
DEVELOPMENT IN THE IMMEDIATE REGION. DISPITE THIS TREND...THOSE
STORMS THAT DO DEVELOP MAY BE ON THE STRONG SIDE. THE LATEST DAY
ONE CONVECTIVE OUTLOOK BY SPC PLACES A SLIGHT RISK OF SEVERE
WEATHER ACROSS THESE TWO COUNTIES THIS AFTERNOON AND OVERNIGHT.
WILL BE ADJUSTING THE HAZARDOUS WEATHER OUTLOOK TO ACCOUNT FOR
THIS. THE CONCERN IS FOR SOME STORMS TO CONTAIN DAMAGING WINDS.
OTHERWISE...HAVE TWEAKED HOURLY TEMPERATURE...DEW POINT AND SKY
COVER GRIDS BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS
THROUGH THE AFTERNOON.
AS OF 940 AM EDT WEDNESDAY...
A FRONTAL BOUNDARY EXTENDED FROM LOWER MICHIGAN SOUTHWEST INTO
NORTHERN MISSOURI. THIS FEATURE WILL SLOW MOVE SOUTH TODAY. WAVES
OF ENERGY WILL BE RIDING ALONG THIS BOUNDARY...AND BRINGING ROUNDS
OF SHOWERS AND STORMS TO THE OHIO VALLEY. ISOLATED SHOWERS AND
STORMS OF THE SOUTHERN PERIPHERY OF THIS ACTIVITY IS EXPECTED TO
BRUSH THE FAR NORTHWESTERN EXTENT OF THE FORECAST AREA. THE
GREATEST EXTENT OF THE ISOLATED COVERAGE WILL LATE THIS
AFTERNOON...AND ALONG AND NORTH OF A MATOKA WV TO A GOSHEN VA
LINE.
OUR EARLIER FORECAST HAS BEEN ADJUSTED TO DEPICT A SLIGHTLY SLOWER
PROGRESSION OF THE SHOWERS AND STORMS INTO OUR REGION. OTHER THAN
THAT...HAVE MAKE TWEAKS IN THE TEMPERATURE...DEW
POINT...WIND...AND SKY COVER TO DEPICT THE LATEST OBSERVATIONS AND
EXPECTED TRENDS INTO THE EARLY AFTERNOON.
AS OF 420 AM EDT WEDNESDAY...
UPPER TROF WILL DIG INTO THE GREAT LAKES TODAY THEN MOVE EAST. 500
MB PATTERN OVER THE MID ATLANTIC REGION REMAINS ZONAL. FORECAST
AREA WELL WITHIN THE WARM SECTOR AHEAD OF A COLD FRONT THAT
EXTENDED FROM ONTARIO INTO NORTHERN MISSOURI. THE FRONT WILL MOVE
MUCH FASTER EAST THAN SOUTH AND SHOULD TRAIL FROM THE NEW ENGLAND
STATES INTO THE CENTRAL PLAINS BY THIS EVENING. BY THURSDAY
MORNING THE FRONT WILL BE OVER THE FORECAST AREAS BUT PARALLEL TO
THE UPPER FLOW SO EXPECTING LITTLE CHANGE IN THE SURFACE PATTERN FOR
THURSDAY.
CLUSTERS OF SHOWERS AND THUNDERSTORMS LINED UP ALONG THE FRONT AT
4AM. AS THE FRONT GETS CLOSER TO THE COUNTY WARNING AREA SO WILL
THE PRECIPITATION. SREF...LATEST RUC AND LOCAL WRF ALL BRING THE
PROBABILITY OF PRECIPITATION INTO THE NORTHWEST COUNTIES OF THE
FORECAST AREA THIS AFTERNOON. MOST LOCATIONS WILL HAVE ENOUGH
HEATING THIS MORNING TO HAVE ENOUGH INSTABILITY TO SUPPORT
THUNDERSTORMS THIS AFTERNOON.
HAVE TRIMMED HIGHS FOR TODAY ACROSS BATH AND GREENBRIER COUNTIES
WHERE THE CLOUDS WILL MOVE IN THE SOONEST. LOWS TONIGHT WILL
REMAIN MILD WITH ENOUGH MIXING AND CLOUDS TO HOLD UP MINIMUM
TEMPERATURES. STAYED WITH WARMER GUIDANCE FOR LOWS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
A QUASI-STATIONARY COLD FRONT WILL BEGIN TO DRIFT TO THE SOUTH
THURSDAY INTO FRIDAY. THIS FRONT WILL THEN STALL ON THE WESTERN SIDE
OF THE APPALACHIANS FRIDAY NIGHT. ONE REASON THIS FRONT IS SLOW TO
MOVE IS BECAUSE OF ZONAL FLOW ALOFT. ALSO TRAPPED IN THIS ZONAL FLOW
IS A WEAK RIDGE OF HIGH PRESSURE. THIS RIDGE WILL TRACK FROM THE
GREAT LAKES INTO NORTHEASTERN USA BY THURSDAY NIGHT. MODELS
INDICATING THIS RIDGE WILL WEDGE DOWN THE MID ATLANTIC THURSDAY
NIGHT. THIS WEDGE LOOKS SHALLOW AND SHOULD RETREAT TO THE NORTH
FRIDAY AFTERNOON IF LITTLE RAIN FALLS INTO IT.
WITH ZONAL FLOW...WE WILL NEED TO KEEP AN EYE ON THE MID WEST TO SEE
IF ANY STRONG COMPLEXES DRIFT OUR WAY...AS IN THE CASE YESTERDAY.
FOR NOW...MODELS ONLY BRING WEAK WAVES OVER THE AREA. RAIN CHANCES
WILL ALSO GET A BOOST FROM ISENTROPIC LIFT FRIDAY AND FRIDAY NIGHT.
THE BEST ISENTROPIC LIFT AND HEAVIER RAIN SHOULD REMAIN NORTH OF THE
AREA AND ALONG THE MASON-DIXON LINE. THE POTENTIAL FOR SEVERE
WEATHER IS LOW UNLESS A MESOSCALE COMPLEX SURVIVES THE TRIP FROM THE
MID WEST. THE WAY THINGS ARE LOOKING NOW...ONLY ELEVATED THUNDER
FROM SCATTERED STORMS ARE EXPECTED.
TEMPERATURES WILL REMAIN ABOVE NORMAL AS ALONG AS THE FRONT STAYS TO
OUR NORTH AND WEST. IF SHOWERS ARE SCATTERED OVER THE
REGION...ENOUGH ISOLATION SHOULD PEAK TEMPERATURES IN THE MID TO
UPPER 80S IN THE EAST. ACROSS THE MOUNTAINS...UPPER 70S TO LOWER 80S
EXPECTED THURSDAY. SIMILAR TEMPERATURES CAN BE ACHIEVED FRIDAY IF
THE RAIN HOLDS OFF. WITH RAIN EXPECTED...NEAR 80F IN THE EAST TO
LOWER TO MIDDLE 70S WEST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 245 PM EDT TUESDAY...
FRONTAL BOUNDARY IS GOING TO PLAY HAVOC WITH OUR WEATHER AND THE
FORECAST IN GENERAL THIS PERIOD. THE FRONT WORKS INTO THE AREA EARLY
IN THE PERIOD...THEN AS UPPER LOW OVER SRN ONTARIO DEEPENS INTO THE
GREAT LAKES OVER THE WEEKEND...IT SHOULD BE PUSHING THE FRONT
FURTHER SOUTH...WHILE SFC HIGH BUILDS INTO THE MID ATLANTIC.
HOWEVER..THE SW FLOW ALOFT GIVEN UPPER LOW/TROUGH BEING JUST WEST OF
US MAY HANG THE FRONT ACROSS THE CAROLINAS INTO ERN VA...WHILE WAVES
OF LOW PRESSURE MOVE ALONG IT KEEPING CLOUDS AND THREAT OF SHOWERS
AROUND. THIS WILL IMPACT TEMPS AND DECIDED TO GO CLOSER TO THE ECMWF
MOS. EARLY NEXT WEEK MODELS DIVERGE WITH BOTH AGREEING ON THE NRN
STREAM LOW LIFTING NEWD BUT SHOWING DIFFERENCES ON THE SRN STREAM.
THE GFS IS SHOWING SHARPER TROUGH MONDAY WHICH COULD SHIFT DEEPER
MOISTURE EAST...ALTHOUGH THE GFS/ECMWF DO SHOWING ANOTHER TROUGH
DEVELOPING ACROSS THE LOWER MISSISSIPPI VALLEY MONDAY...BUT WITH
UPSTREAM DIFFERENCES...THE ECMWF SHOWS MORE SOUTHERLY FLOW ALOFT
WHILE THE GFS BREAKS OFF AN UPPER HIGH INTO THE OHIO VALLEY
DEPICTING MORE NW FLOW ALOFT. ECMWF HAS BEEN DOING A BETTER JOB
OVERALL...AND HPC LINGERS THE FRONT AROUND THE EASTERN CAROLINAS
MON-TUE WITH CHANCES FOR PRECIP REMAINING. WEDGE MAY DEVELOP AS SFC
HIGH BUILDS SWD FROM THE MID ATLANTIC BY TUESDAY WITH EASTERLY FLOW
KEEPING MORE CLOUDS AROUND.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 1230 PM EDT WEDNESDAY...
VFR CONDITIONS WILL PREVAIL ACROSS THE REGION THROUGH
06Z...2AM...THURSDAY MORNING. AT THIS TIME...WE ARE ANTICIPATING
THE DEVELOPMENT OF SOME PATCHY VALLEY MVFR/IFR FOG IN MAINLY THE
GREENBRIER AND NEW RIVER VALLEYS. HAVE GONE WITH COMPARABLE
CONDITIONS AT KBCB AS OCCURRED THIS MORNING. AT KLWB...A
CIRR0STRATUS CEILING IS EXPECTED TO MOVE OVERHEAD DURING THE
OVERNIGHT. THIS IS EXPECTED TO HELP KEEP CONDITIONS FROM DROPPING
BELOW IFR AS OCCURRED THIS MORNING. HOWVER...THE PRESENCE OF THESE
CLOUDS WILL MEAN A SLIGHTLY LONGER RECOVERY TIME TO VFR THURSDAY
MORNING AT KLWB AS COMPARED TO THIS MORNING. THE REMAINING TAF
SITES ARE EXPECTED TO REMAIN VFR THROUGH THE NIGHT.
AS A FRONTAL BOUNDARY APPROACHES THE REGION FROM THE OHIO
VALLEY...ISOLATED SHOWERS AND STORMS WILL BE POSSIBLE LATE THIS
AFTERNOON AND EVENING NEAR OR NORTH OF KLWB. HAVE NOT INCLUDED ANY
PREVAILING OR TEMPO CONDITIONS FOR THESE AT KLWB AT THIS TIME
GIVEN THE EXPCECT ISOLATED NATURE OF THE ACTIVITY.
AS THE FRONT DRAWS CLOSER ON THURSDAY...KBLF...IN ADDITION TO
KLWB...WILL ALSO HAVE THE POTENTIAL FOR ISOLATED SHOWERS OR
STORMS NEAR IT BY 18Z...2PM. AGAIN HAVE NOT INCLUDED THIS
POTENTIAL IN THE TAFS GIVEN THE ISOLATED NATURE OF THE ACTIVITY
AND THE TIME SCALE FROM NOW.
MVFR CONDITIONS AND A GREATER COVERAGE OF SHOWERS AND STORMS ARE
EXPECTED THURSDAY INTO THE START OF THE WEEKEND AS THE FRONT MOVES
INTO THE REGION...STALLS...AND THEN HEADS SOUTH OF THE AREA.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/DS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...WP
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1249 PM EDT WED SEP 26 2012
.SYNOPSIS...
A COLD FRONT OVER THE OHIO VALLEY MOVES EAST TODAY AND TONIGHT AND
STALLS FROM THE MID ATLANTIC TO THE CENTRAL PLAINS ON THURSDAY.
THIS FRONT WILL GRADUALLY DRIFT INTO THE SOUTHEAST UNITED STATES ON
SATURDAY AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1245 PM EDT WEDNESDAY...
THE TREND FOR A SLOWER AND FARTHER NORTH DEVELOP OF AFTERNOON
SHOWERS AND STORMS CONTINUES. HAVE CONFINED THE CHANCES TO
PRIMARILY NORTHERN GREENBRIER AND BATH COUNTIES THIS AFTERNOON
BASED UPON THE LATEST UPSTREAM RADAR TRENDS AND LACK OF
DEVELOPMENT IN THE IMMEDIATE REGION. DISPITE THIS TREND...THOSE
STORMS THAT DO DEVELOP MAY BE ON THE STRONG SIDE. THE LATEST DAY
ONE CONVECTIVE OUTLOOK BY SPC PLACES A SLIGHT RISK OF SEVERE
WEATHER ACROSS THESE TWO COUNTIES THIS AFTERNOON AND OVERNIGHT.
WILL BE ADJUSTING THE HAZARDOUS WEATHER OUTLOOK TO ACCOUNT FOR
THIS. THE CONCERN IS FOR SOME STORMS TO CONTAIN DAMAGING WINDS.
OTHERWISE...HAVE TWEAKED HOURLY TEMPERATURE...DEW POINT AND SKY
COVER GRIDS BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS
THROUGH THE AFTERNOON.
AS OF 940 AM EDT WEDNESDAY...
A FRONTAL BOUNDARY EXTENDED FROM LOWER MICHIGAN SOUTHWEST INTO
NORTHERN MISSOURI. THIS FEATURE WILL SLOW MOVE SOUTH TODAY. WAVES
OF ENERGY WILL BE RIDING ALONG THIS BOUNDARY...AND BRINGING ROUNDS
OF SHOWERS AND STORMS TO THE OHIO VALLEY. ISOLATED SHOWERS AND
STORMS OF THE SOUTHERN PERIPHERY OF THIS ACTIVITY IS EXPECTED TO
BRUSH THE FAR NORTHWESTERN EXTENT OF THE FORECAST AREA. THE
GREATEST EXTENT OF THE ISOLATED COVERAGE WILL LATE THIS
AFTERNOON...AND ALONG AND NORTH OF A MATOKA WV TO A GOSHEN VA
LINE.
OUR EARLIER FORECAST HAS BEEN ADJUSTED TO DEPICT A SLIGHTLY SLOWER
PROGRESSION OF THE SHOWERS AND STORMS INTO OUR REGION. OTHER THAN
THAT...HAVE MAKE TWEAKS IN THE TEMPERATURE...DEW
POINT...WIND...AND SKY COVER TO DEPICT THE LATEST OBSERVATIONS AND
EXPECTED TRENDS INTO THE EARLY AFTERNOON.
AS OF 420 AM EDT WEDNESDAY...
UPPER TROF WILL DIG INTO THE GREAT LAKES TODAY THEN MOVE EAST. 500
MB PATTERN OVER THE MID ATLANTIC REGION REMAINS ZONAL. FORECAST
AREA WELL WITHIN THE WARM SECTOR AHEAD OF A COLD FRONT THAT
EXTENDED FROM ONTARIO INTO NORTHERN MISSOURI. THE FRONT WILL MOVE
MUCH FASTER EAST THAN SOUTH AND SHOULD TRAIL FROM THE NEW ENGLAND
STATES INTO THE CENTRAL PLAINS BY THIS EVENING. BY THURSDAY
MORNING THE FRONT WILL BE OVER THE FORECAST AREAS BUT PARALLEL TO
THE UPPER FLOW SO EXPECTING LITTLE CHANGE IN THE SURFACE PATTERN FOR
THURSDAY.
CLUSTERS OF SHOWERS AND THUNDERSTORMS LINED UP ALONG THE FRONT AT
4AM. AS THE FRONT GETS CLOSER TO THE COUNTY WARNING AREA SO WILL
THE PRECIPITATION. SREF...LATEST RUC AND LOCAL WRF ALL BRING THE
PROBABILITY OF PRECIPITATION INTO THE NORTHWEST COUNTIES OF THE
FORECAST AREA THIS AFTERNOON. MOST LOCATIONS WILL HAVE ENOUGH
HEATING THIS MORNING TO HAVE ENOUGH INSTABILITY TO SUPPORT
THUNDERSTORMS THIS AFTERNOON.
HAVE TRIMMED HIGHS FOR TODAY ACROSS BATH AND GREENBRIER COUNTIES
WHERE THE CLOUDS WILL MOVE IN THE SOONEST. LOWS TONIGHT WILL
REMAIN MILD WITH ENOUGH MIXING AND CLOUDS TO HOLD UP MINIMUM
TEMPERATURES. STAYED WITH WARMER GUIDANCE FOR LOWS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 400 AM EDT WEDNESDAY...
A QUASI-STATIONARY COLD FRONT WILL BEGIN TO DRIFT TO THE SOUTH
THURSDAY INTO FRIDAY. THIS FRONT WILL THEN STALL ON THE WESTERN SIDE
OF THE APPALACHIANS FRIDAY NIGHT. ONE REASON THIS FRONT IS SLOW TO
MOVE IS BECAUSE OF ZONAL FLOW ALOFT. ALSO TRAPPED IN THIS ZONAL FLOW
IS A WEAK RIDGE OF HIGH PRESSURE. THIS RIDGE WILL TRACK FROM THE
GREAT LAKES INTO NORTHEASTERN USA BY THURSDAY NIGHT. MODELS
INDICATING THIS RIDGE WILL WEDGE DOWN THE MID ATLANTIC THURSDAY
NIGHT. THIS WEDGE LOOKS SHALLOW AND SHOULD RETREAT TO THE NORTH
FRIDAY AFTERNOON IF LITTLE RAIN FALLS INTO IT.
WITH ZONAL FLOW...WE WILL NEED TO KEEP AN EYE ON THE MID WEST TO SEE
IF ANY STRONG COMPLEXES DRIFT OUR WAY...AS IN THE CASE YESTERDAY.
FOR NOW...MODELS ONLY BRING WEAK WAVES OVER THE AREA. RAIN CHANCES
WILL ALSO GET A BOOST FROM ISENTROPIC LIFT FRIDAY AND FRIDAY NIGHT.
THE BEST ISENTROPIC LIFT AND HEAVIER RAIN SHOULD REMAIN NORTH OF THE
AREA AND ALONG THE MASON-DIXON LINE. THE POTENTIAL FOR SEVERE
WEATHER IS LOW UNLESS A MESOSCALE COMPLEX SURVIVES THE TRIP FROM THE
MID WEST. THE WAY THINGS ARE LOOKING NOW...ONLY ELEVATED THUNDER
FROM SCATTERED STORMS ARE EXPECTED.
TEMPERATURES WILL REMAIN ABOVE NORMAL AS ALONG AS THE FRONT STAYS TO
OUR NORTH AND WEST. IF SHOWERS ARE SCATTERED OVER THE
REGION...ENOUGH ISOLATION SHOULD PEAK TEMPERATURES IN THE MID TO
UPPER 80S IN THE EAST. ACROSS THE MOUNTAINS...UPPER 70S TO LOWER 80S
EXPECTED THURSDAY. SIMILAR TEMPERATURES CAN BE ACHIEVED FRIDAY IF
THE RAIN HOLDS OFF. WITH RAIN EXPECTED...NEAR 80F IN THE EAST TO
LOWER TO MIDDLE 70S WEST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 245 PM EDT TUESDAY...
FRONTAL BOUNDARY IS GOING TO PLAY HAVOC WITH OUR WEATHER AND THE
FORECAST IN GENERAL THIS PERIOD. THE FRONT WORKS INTO THE AREA EARLY
IN THE PERIOD...THEN AS UPPER LOW OVER SRN ONTARIO DEEPENS INTO THE
GREAT LAKES OVER THE WEEKEND...IT SHOULD BE PUSHING THE FRONT
FURTHER SOUTH...WHILE SFC HIGH BUILDS INTO THE MID ATLANTIC.
HOWEVER..THE SW FLOW ALOFT GIVEN UPPER LOW/TROUGH BEING JUST WEST OF
US MAY HANG THE FRONT ACROSS THE CAROLINAS INTO ERN VA...WHILE WAVES
OF LOW PRESSURE MOVE ALONG IT KEEPING CLOUDS AND THREAT OF SHOWERS
AROUND. THIS WILL IMPACT TEMPS AND DECIDED TO GO CLOSER TO THE ECMWF
MOS. EARLY NEXT WEEK MODELS DIVERGE WITH BOTH AGREEING ON THE NRN
STREAM LOW LIFTING NEWD BUT SHOWING DIFFERENCES ON THE SRN STREAM.
THE GFS IS SHOWING SHARPER TROUGH MONDAY WHICH COULD SHIFT DEEPER
MOISTURE EAST...ALTHOUGH THE GFS/ECMWF DO SHOWING ANOTHER TROUGH
DEVELOPING ACROSS THE LOWER MISSISSIPPI VALLEY MONDAY...BUT WITH
UPSTREAM DIFFERENCES...THE ECMWF SHOWS MORE SOUTHERLY FLOW ALOFT
WHILE THE GFS BREAKS OFF AN UPPER HIGH INTO THE OHIO VALLEY
DEPICTING MORE NW FLOW ALOFT. ECMWF HAS BEEN DOING A BETTER JOB
OVERALL...AND HPC LINGERS THE FRONT AROUND THE EASTERN CAROLINAS
MON-TUE WITH CHANCES FOR PRECIP REMAINING. WEDGE MAY DEVELOP AS SFC
HIGH BUILDS SWD FROM THE MID ATLANTIC BY TUESDAY WITH EASTERLY FLOW
KEEPING MORE CLOUDS AROUND.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 740 AM EDT WEDNESDAY...
EXPECT PATCHY FOG AT BCB TO DISSIPATE BY 14Z/10AM. CLOUDS WILL
CONTINUE TO SPREAD BACK INTO THE AREA FROM THE WEST THIS MORNING.
PROBABILITY OF PRECIPITATION THROUGH 00Z/8PM TONIGHT IS NOT HIGH
ENOUGH TO INCLUDE IN THE TAFS AT THIS TIME. BEST CHANCE REMAINS
WEST AND NORTH OF LWB.
AS A COLD FRONT APPROACHES THE REGION TONIGHT THE CHANCE OF
PRECIPITATION WITH MVFR CEILINGS AND VISIBILITIES INCREASES AT
LWB AND BLF.
MVFR CONDITIONS ARE EXPECTED TO BECOME MORE WIDESPREAD ON THURSDAY
AND PERSIST INTO SATURDAY AS A COLD FRONT STALLS ACROSS THE AREA.
HIGH CONFIDENCE OF OCCASIONAL SHOWERS AND THUNDERSTORMS. ALSO PATCHY
MORNING FOG MAY DEVELOP DURING THE PREDAWN HOURS AT LWB/BCB...AND
AT ANY SITES THAT GET PRECIPITATION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/DS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...WP
AVIATION...AMS/RAB