Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/30/12
AREA FORECAST DISCUSSION
NWS DENVER CO
1032 AM MDT FRI SEP 28 2012
.UPDATE...CORRECTION TO LINE 18 OF FIRST PARAGRAPH
&&
.SHORT TERM...DENSE FOG ADVISORY WAS HOISTED EARLIER THIS MORNING
FOR PORTIONS OF THE SOUTH PLATTE RIVER BASIN DOWN STREAM FROM THE
DENVER METRO AREA. VISIBILITIES LESS THAN A QUARTER MILE WERE
OBSERVED AT LONGMONT...GREELEY...FT MORGAN AND STERLING...TO NAME
BUT A FEW LOCATIONS. HOWEVER IN THE PAST HOUR...THE TREND HAS BEEN
UP AND THEREFORE THE ADVISORY MAY BE DROPPED SHORTLY. THE PATCHY
FOG HANGING AROUND IN THE NORTH AND MIDDLE PARKS SHOULD ALSO BURN
OFF THIS HOUR. OTHERWISE...THE REST OF THE FORECAST APPEARS ON
TRACK. ALREADY BEGINNING TO SEE CUMULUS FORMING OVER THE FOOTHILLS
AND HIGHER RIDGES ALONG THE CONTINENTAL DIVIDE. LATEST HRRR AND
NAM RUNS INDICATE A SLOW BUT STEADY INCREASE IN CAPE OVER THE
FRONT RANGE OVER THE NEXT FEW HOURS...WITH VALUES APPROACHING 400
J/KG BY MID-AFTERNOON. ON THE PLAINS THE FOG AND STRATUS
BLANKETING MUCH OF THE SOUTH PLATTE BASIN DOWNSTREAM FROM DENVER
SHOULD REMAIN STRONGLY CAPPED AT LEAST THOUGH MID-AFTERNOON.
FARTHER SOUTH ALONG THE SPINE OF THE PALMER DIVIDE IN
DOUGLAS...ELBERT AND NRN LINCOLN COUNTIES...MODELS ALSO SHOW CAPES
ON THE RISE THROUGH THE AFTERNOON. THE HRRR INDICATES CAPES IN THE
500-1000 J/KG RANGE IN THIS AREA BY MID-AFTERNOON...WHEREAS THE
12Z/NAM ONLY INDICATES CAPES UP AROUND 400 J/KG. THAT SAID...THE
ISOLATED TO SCATTERED POPS FOR THE FRONT RANGE MTNS/FOOTHILLS AND
SOUTH PARK FOR THE AFTERNOON/ EARLY EVENING LOOK GOOD. THE ISOLATED
POPS FOR THE I-25 URBAN CORRIDOR AND PALMER DIVIDE SHOULD ALSO
SUFFICE. SEE LITTLE IF ANY CHANCE FOR PRECIP FARTHER OUT ON THE
PLAINS. FOR THIS FORECAST UPDATE...WHICH HAS ALREADY BEEN
ISSUED...ALSO MADE MINOR ADJUSTMENTS TO TEMPERATURE AND WINDS TO
BETTER REFLECT THE LINGERING CLOUD COVER ON THE PLAINS.
.AVIATION...VFR CONDITIONS ARE TO BE EXPECTED AT DENVER AREA
AIRPORTS. AFTER 21Z TODAY...MAY STILL SEE A LIGHT RAIN SHOWERS OR
WEAK T-STORM DRIFT SOUTHEAST OVER THE DENVER METRO AREA. GUSTY
ERRATIC OUTFLOW AND LIGHTNING MOST LIKELY THE BIGGEST CONCERN WITH
THESE PASSING CELLS. AS FOR WINDS...WINDS SPEEDS GENERALLY BELOW
10KTS WITH A GRADUAL SHIFT TO AN EAST-SOUTHEAST COMPONENT EARLY
THIS AFTERNOON AND A RETURN TO OUR TYPICAL DRAINAGE WIND PATTERN
NOT LONG AFTER SUNSET.
&&
.HYDROLOGY...NO CONCERNS TODAY.
&&
.PREV DISCUSSION... /ISSUED 420 AM MDT FRI SEP 28 2012/
SHORT TERM...FOG AND LOW CLOUDS HAVE DEVELOPED AS EXPECTED ACROSS
MUCH OF NORTHEASTERN COLORADO BEHIND THE CLEARING LINE WHICH IS
NEARING THE EASTERN BORDER. NORTH SIDE OF THE PALMER DIVIDE HAS WEAK
DOWNSLOPE WINDS THOUGH KMNH HAS STILL CARRIED SOME THIN FOG AT
TIMES. LIGHT SOUTH WINDS ARE ALSO KEEPING THE FOG FROM THICKENING
AROUND DENVER SO FAR. ONLY WEAK HINTS OF A DENVER CYCLONE
CIRCULATION...SO STILL SOME UNCERTAINTY ABOUT WHETHER DENVER WILL
SOCK IN OVER THE NEXT FEW HOURS. AT THIS POINT MY BEST ESTIMATE IS
THAT THE FOG WILL CONTINUE TO EXPAND ON ITS FRINGES INTO BOULDER
COUNTY AND THE NORTHERN PART OF THE DENVER METRO AREA...BUT NOT MAKE
A WHOLESALE SOUTHWARD PUSH. WEBCAMS LOOK TO BE MOSTLY IN THE QUARTER
TO HALF MILE RANGE IN THE FOGGIER AREAS FROM LOVELAND OUT TO
STERLING.
THE VALLEY INVERSIONS WILL NOT HELP WITH THE INSTABILITY THIS
AFTERNOON...EXPECTING LESS CONVECTION AND LATER TODAY THOUGH THERE
WILL LIKELY STILL BE SOME SHOWERS OVER THE MOUNTAINS AND EVENTUALLY
A FEW WEAK THUNDERSTORMS ON THE PLAINS. INHERITED POPS WERE HEDGED
TOWARD THE PALMER DIVIDE AND CREST/EAST SLOPES OF THE FRONT RANGE
AND THAT PATTERN SEEMS FINE. WITH MOISTURE MIXING OUT A BIT...CAPES
ARE FORECAST TO BE AROUND 400 J/KG ALONG THE FRONT RANGE AND 800
J/KG OUT ON THE PLAINS. PRECIPITABLE WATER DROPPING DOWN TO 0.6 TO
0.7...STILL ENOUGH MOISTURE AND SLOW STORM MOTION FOR SOME HEAVY
RAIN WITH A COUPLE OF THE STORMS...BUT NOT MUCH OF A FLOOD THREAT.
EXPECT FASTER CLEARING TONIGHT WITHOUT MUCH TO KEEP CONVECTION
GOING. I LOWERED THE MOUNTAIN LOWS FOR TONIGHT AS THERE SHOULD BE
GOOD RADIATIONAL COOLING.
LONG TERM...UPPER RIDGING TO THE WEST OF COLORADO WILL DOMINATE
THE WEATHER FOR THE CWA SATURDAY THROUGH SUNDAY. WEAK ZONAL FLOW ON
SATURDAY WILL GIVE WAY TO INCREASING NORTHERLY FLOW FOR SUNDAY AND
SUNDAY NIGHT. WEAK DOWNWARD QG VERTICAL VELOCITY IS PROGGED FOR THE
CWA SATURDAY THROUGH SUNDAY NIGHT. THE LOW LEVEL PRESSURE AND WIND
FIELDS HAVE WEAK TROUGHING EAST OF THE MOUNTAINS SATURDAY AND
SATURDAY NIGHT...SO THE BOUNDARY LAYER WINDS MAY HAVE A DOWNSLOPING
COMPONENT TO THEM. THERE IS A WEAK SURGE OF COOLER AIR TO MOVE INTO
THE FORECAST AREA SUNDAY...WITH WEAK NORTHERLY UPSLOPE FLOW
PROGGED. FOR MOISTURE...THERE IS SOME IN THE MID AND UPPER LEVELS
THROUGH THE FOUR PERIODS. THE LOWER LEVELS ARE DRY OVER THE WESTERN
HALF OF THE CWA...WITH SOME 40S F DEW POINTS OVER THE EASTERN PLAINS
..ESPECIALLY ON SATURDAY. THE PRECIPITABLE WATER VALUES ARE IN THE
0.45 TO 0.60 INCH RANGE ALL FOUR PERIODS. THERE IS MORE MOISTURE
PROGGED ON THE THIRD DAY...SUNDAY...ON THESE LATEST MODEL RUNS AS
COMPARED TO YESTERDAY`S RUNS. THIS SEEMS TO BE THE CASE THE LAST
TWO NIGHTS. THERE IS SOME CAPE PROGGED...MAINLY OVER THE PLAINS
SATURDAY AFTERNOON. THE FAR NORTHEAST HAS VALUES UP TO 1000J/KG.
THERE IS VERY LITTLE CAPE PROGGED ON SUNDAY. THE QPF FIELDS SHOW
SMALL AMOUNTS OF MEASURABLE RAINFALL OVER THE CWA LATE IN THE DAY.
SUNDAY LOOKS SIMILAR. FOR POPS WILL GO WITH 10-20%S FOR BOTH LATE
DAY SATURDAY AND LATE DAY SUNDAY. FOR TEMPERATURES...SATURDAY`S
HIGHS ARE PROGGED TO BE 2-3 C WARMER THAN TODAY`S. SUNDAY`S HIGHS
ARE 0.5-1.5 C COOLER THAN SATURDAY`S. FOR THE LATER DAYS...MODELS
HAVE A STRONG UPPER RIDGE TO THE WEST OF COLORADO WITH NORTHERLY
FLOW ALOFT FOR THE CWA MONDAY AND TUESDAY. BY WEDNESDAY AND
THURSDAY THE RIDGE MOVES SOUTH A BIT AND IS SOUTHWEST OF OUR STATE.
THE FLOW ALOFT BECOMES NORTHWESTERLY FOR THE CWA THOSE TWO DAYS.
THE GFS BRINGS A COLD FRONT DOWN TUESDAY NIGHT INTO WEDNESDAY...THE
ECMWF DOES NOT. MOISTURE IS LACKING. NO POPS. WILL KEEP
TEMPERATURES ABOVE SEASONAL NORMALS FOR NOW ALL FOUR DAYS.
AVIATION...FOG NORTH OF THE DENVER AREA SHOULD EXPAND OVER THE NEXT
COUPLE OF HOURS. STILL UNCERTAIN ABOUT HOW MUCH IT WILL IMPACT KDEN
AND KBJC AS THEY LOOK TO BE ON THE EDGE. IF THE FOG DOES GET INTO
KDEN RVRS WILL LIKELY STAY ABOVE 1000 FEET...BUT THERE COULD BE A
COUPLE HOURS OF INSTRUMENT APPROACHES. FOG WILL BE GONE BY 15Z WITH
VFR CONDITIONS THE REST OF THE DAY.
HYDROLOGY...STILL SOME POSSIBILITY OF SOME HEAVY RAIN...HALF AN
INCH IN UNDER AN HOUR...BUT NOT EXPECTING A FLOOD THREAT TODAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM MDT THIS MORNING FOR COZ043-044-
048.
&&
$$
SHORT TERM...BAKER/GIMMESTAD
LONG TERM....RJK
AVIATION...BAKER/GIMMESTAD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
428 PM EDT FRI SEP 28 2012
.SYNOPSIS...
RAIN WILL CONTINUE TO PLAGUE THE REGION OVERNIGHT AS A BROAD AREA
OF LOW PRESSURE GRADUALLY LIFTS THROUGH THE REGION. ANTICIPATE
ACTIVITY TO DIMINISH ACROSS INTERIOR NEW ENGLAND FOR SATURDAY IN
THE FORM OF LIGHT SHOWERS AND DRIZZLE...WHILE THE EASTERN HALF
CONTINUES TO BE IMPACTED BY RAIN. ACTIVITY SHOULD DIMINISH INTO
SUNDAY AND SUNDAY NIGHT...WITH A BRIEF PERIOD OF HIGH PRESSURE FOR
MONDAY INTO TUESDAY. ANOTHER DISTURBANCE IS POSSIBLE FOR THE
MIDWEEK PERIOD...ESPECIALLY ALONG THE SOUTH COAST. HIGH PRESSURE
RETURNS FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
215 PM UPDATE...
28/15Z RAP MODEL HAD AN EXCELLENT HANDLE ON LOCATION AND TIMING OF
PRECIPITATION ACROSS SOUTHERN NEW ENGLAND EARLY THIS AFTERNOON.
HAD THE FRONTAL BOUNDARY BETWEEN NORWOOD AND MARSHFIELD MA...
EXTENDING SOUTHWEST ACROSS RI TO BE BETWEEN WILLIMANTIC CT AND
WESTERLY RI. THIS SHOULD BE THE FOCUS FOR THE HEAVIEST RAINFALL
LATER THIS AFTERNOON AND EVENING.
NOT MUCH SURFACE-BASED INSTABILITY TO WORK WITH ACROSS SOUTHERN
NEW ENGLAND AND THE BEST WIND SHEAR REMAINS TO THE SOUTH AS WELL.
WE HAVE NOTICED THE STRONGEST CONVECTION ACROSS CONTINUES TO
BACK-BUILD ACROSS LONG ISLAND SOUND...ANOTHER INDICATION OF THE
WEAK INSTABILITY ACROSS OUR REGION. THAT SAID...CANNOT COMPLETELY
RULE OUT A THUNDERSTORM LATER THIS AFTERNOON ACROSS PORTIONS OF RI
AND SOUTHEAST MA. PRECIPITABLE WATER CONTINUES TO BE OVER 2
INCHES...SO LOCALLY HEAVY DOWNPOURS WILL ALSO BE A POSSIBILITY.
DO NOT HAVE A LOT OF FAITH IN THE TIMING DETAILS OF THE 28/12Z
GUIDANCE. AS SUCH FAVORED A BLEND OF THE AVAILABLE GUIDANCE FOR
TIMING THE PRECIPITATION. EXPECTING ONE AREA OF ISENTROPIC LIFT ON
TE 295K AND 300K SURFACES TO MOVE OFFSHORE AND NORTH OF SOUTHERN
NEW ENGLAND OVERNIGHT. THIS SHOULD BRING IN A RELATIVE DRY PERIOD
LATE TONIGHT...ESPECIALLY ACROSS THE WESTERN HALF OF SOUTHERN NEW
ENGLAND.
TEMPERATURES NOT EXPECTED TO MOVE MUCH FROM PRESENT LEVELS. USED A
BLEND OF THE MOS GUIDANCE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
EXPECTING A BROAD SURFACE TROUGH TO LONGER ACROSS THE COAST OF
SOUTHERN NEW ENGLAND SATURDAY INTO SATURDAY NIGHT. CANNOT RULE OUT
SOME AREAS OF RAIN AS THE AIRMASS DOES NOT DRY OUT APPRECIABLY.
AGAIN CONFIDENCE IN THE TIMING IS LOW. DO EXPECT THE GREATEST RISK
OF RAINFALL TO BE ALONG THE EAST COAST OF MA AND THE MA COASTAL
WATERS.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* SHOWERS DISSIPATING INTO MONDAY
* BRIEF PERIOD OF HIGH PRES INTO TUESDAY
* WET WX MAY PREVAIL FOR MUCH OF THE MIDWEEK
* COOLER INTO THE WEEKEND WITH A PSBL WX DISTURBANCE
MODEL ANALYSIS...
THE 28/12Z GFS SEEMINGLY PROGRESSES SLIGHTLY FASTER THAN OTHER MDL
SOLNS IN REGARDS TO H85 HEIGHTS...AND THERE ARE NOTABLE DIFFERENCES
IN REGARDS TO SFC FEATURES IN COMPARISON TO SHORT-TERM GUIDANCE THRU
MONDAY. WITH REGARDS TO THE SUNDAY-MONDAY FCST...LEANED TOWARDS A
BLEND OF THE NAM/ECMWF GUIDANCE. THEREAFTER THE FCST PD REMAINS
UNCERTAIN. IT WAS WITH YESTERDAYS MDL SOLNS THAT HIGH PRES WOULD
HOLD IN PLACE KEEPING DISTURBANCES ASSOC WITH REMNANT TROPICAL
ENERGY WELL OFFSHORE ALONG THE ATTENDANT STALLED SFC BOUNDARY. WITH
TODAYS LATEST MDL SUITE...THE SFC BOUNDARY IS PROGGED TO RETROGRADE
TOWARDS INTERIOR NEW ENGLAND AS LOW PRES LIFTS FROM THE GULF COAST
FURTHER N INTO THE MID-ATLANTIC. CONFIDENCE WANES FOR THE MID-WEEK
TIME FRAME ACCORDINGLY...AND FOR ALL DAYS THEREAFTER. ON A FINAL
NOTE...THERE REMAINS A PERSISTENT SIGNAL OF HIGH PRES AND MUCH
COOLER AND DRIER AIR BUILDING DOWN FROM CENTRAL CANADA. THERE IS
STILL A HINT THAT A TASTE OF AUTUMN MAY BE ON THE NEAR HORIZON.
DETAILS...
SUNDAY...
GREATER CONFIDENCE IS WEIGHTED TOWARDS THE 28/12Z NAM AND 28/0Z
ECMWF. SOLNS HIGHLIGHT THE BEST CHCS FOR RAIN ACROSS S/E NEW
ENGLAND IN PROXIMITY TO THE STALLED OFFSHORE FRONTAL BOUNDARY ALONG
WHICH THE BETTER MOIST AXIS AND ATTENDANT FORCING RESIDE. WEAK WAVES
OF LOW PRES ADVECTING NEWD ALONG THE BOUNDARY ADD AN ADDITIONAL
FOCUS FOR ENHANCED RAIN FOR AFOREMENTIONED RGNS. AREAS OF HEAVY RAIN
ARE PSBL WITH THE CHC FOR THUNDERSTORMS...ESPECIALLY ACROSS SERN NEW
ENGLAND. LIKELY POPS ARE WARRANTED. AS FOR INTERIOR NEW ENGLAND
THERE IS A GREATER AMNT OF UNCERTAINTY. MDL SOLNS CONTINUE TO KEY ON
DRIER AIR ENTRAINING ALONG THE ERN PERIPHERY OF THE ERN GRT LKS
NEARLY-STACKED CLOSED LOW...WITH 28/12Z NAM MDL SOUNDINGS EXHIBITING
A FAIRLY DRY ATMOS INDICATIVE OF SCT-BKN CLOUD COVER AND VERY LITTLE
CHC OF RAIN. WILL STILL INCITE SOME SLGT CHC POPS AS SHRTWV ENERGY
PINWHEELS AROUND THE AFOREMENTIONED LOW AND CYCLONIC FLOW PREVAILS.
OVERALL WLY FLOW WITH TEMPS PSBLY INTO THE UPR 60S-LOW 70S FOR THE
CT VLY.
SUNDAY NIGHT INTO MONDAY...
NEARLY-STACKED CLOSED LOW LIFTS NEWD INTO THE ST LAWRENCE RVR VLY.
WHILE DRIER AIR CONTINUALLY ENTRAINS TO THE REAR OF THE DEPARTING
SYSTEM /ALLOWING SERN NEW ENGLAND TO DRY OUT AFTER DUSK/...IT IS
PLAUSIBLE THAT AN INVERTED TROF SWEEPING ACROSS THE RGN WITH
DEPARTURE OF THE LOW WILL BE THE FOCUS FOR ADDITIONAL SHOWER
DEVELOPMENT...YET THE BETTER MOISTURE AVAILABILITY AND FORCING LOOK
TO LIFT N OF THE FCST RGN PARENT WITH THE DEPARTING LOW. WILL INVOKE
SLGT CHC POPS WITH TRENDS FOR GRADUAL CLEARING BY MONDAY MORNING.
THE SPEED AT WHICH CONDITIONS IMPROVE REMAINS UNCERTAIN...BUT A
BLEND OF THE 28/12Z NAM AND 28/0Z ECMWF SUFFICES. A MILD NGT ON TAP
WITH CLOUDS AND MOISTURE LINGERING...LOOKING TO BE A WARM AND DRY
DAY MONDAY WITH HIGHS INTO THE LOW 70S. W/SWLY FLOW PREVAILS.
MONDAY NIGHT THROUGH THURSDAY...
BOTH THE 28/12Z GFS AND 28/0Z ECMWF HAVE ALTERED THEIR APPROACH IN
HANDLING THE REMNANTS OF TS MIRIAM /EAST-PACIFIC DISTURBANCE/ ACROSS
MEXICO EWD ALONG THE GULF COAST AND LIFTING NEWD THRU THE LONG WAVE
PATTERN INTO NEW ENGLAND. THE PRESENT SYNOPSIS IS FOR ATTENDANT
ENERGY TO ELONGATE AGAINST THE WRN PERIPHERY OF THE STOUT RIDGE OF
HIGH PRES ANCHORED OVER THE ATLANTIC. AN ATTENDANT WAVE OF SFC LOW
PRES LIFTING CONCURRENTLY THRU THE MID-ATLANTIC DURING THIS PD ACTS
TO DRAG THE STALLED OFFSHORE FRONTAL BOUNDARY /WHICH AT THIS POINT WAS
THE FOCUS FOR ACTIVE WX ON SUNDAY/ NWD AS A WARM FRNT. WHILE IT IS
LIKELY THAT MDL SOLNS WILL ALTER IN TIME...THERE REMAINS AN ENHANCED
THREAT OF RAIN...POSSIBLY HEAVY AT TIMES...ALONG THE S COASTLINE OF
NEW ENGLAND WHERE THE STALLED FRONTAL BOUNDARY SHALL RESIDE BY TUE NGT
THRU THURS NGT ALONG AS ADDITIONAL WEAK WAVES OF LOW PRES WILL
TRAVERSE ALONG THE AFOREMENTIONED FRONTAL BOUNDARY.
FRIDAY ONWARD...
THE 28/0Z ECMWF IS STILL KEYING UPON SOME INFLUENCE OF HIGH PRES
BUILDING S/E OUT OF CENTRAL CANADA AS MID-WEEK SRN STREAM ENERGY IS
PUSHED OUT BY A SLIGHT STRONG NRN STREAM DISTURBANCE. W/NWLY FLOW
PREVAILS IN WAKE OF THE TWO USHERING MUCH COOLER AND DRIER AIR
ACROSS THE RGN. CPC CONTINUES TO HINT AT SOME BELOW NORMAL TEMPS FOR
THE CONUS IN ITS 8-14 DAY OUTLOOK. SOME HINT AMONGST THE FCST
GUIDANCE FOR ANOTHER DISTURBANCE BY THE END OF THE WEEKEND INTO THE
BEGINNING OF NEXT WEEK.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
SHORT TERM...
THROUGH 00Z...MODERATE CONFIDENCE. TIMING OF RAIN AND LOWER CLOUDS
CONTINUES TO BE PROBLEMATIC FOR SOME TERMINALS. DO EXPECT IFR
CONDITIONS TO PREVAIL LATE THIS AFTERNOON ACROSS THE INTERIOR...
WITH VFR TO MVFR CONDITIONS ACROSS THE CAPE AND ISLANDS.
TONIGHT...MODERATE TO HIGH CONFIDENCE.
ONE BATCH OF RAIN MOVES OFF...A SECOND MOVES UP FROM THE SOUTH.
EITHER WAY...EXPECTING CIGS TO REMAIN MVFR WITH AREAS OF IFR IN
RAIN AND FOG. VSBYS ALSO MVFR WITH AREAS OF IFR IN HEAVIER RAIN
AREAS. SOME POTENTIAL FOR TSTMS TO DEVELOP...MAINLY ALONG THE
SOUTH COAST AND THE COASTAL PLAIN.
SATURDAY...MODERATE CONFIDENCE.
COASTAL LOW PRESSURE PASSES AND MOVES OFF THROUGH THE GULF OF
MAINE. DIMINISHING COVERAGE OF RAIN. VSBYS IMPROVE ESPECIALLY IN
THE AFTERNOON. CEILINGS MAY IMPROVE...BUT LESS CERTAIN. POTENTIAL
FOR LINGERING MVFR CIGS IN EASTERN MA DURING THE AFTERNOON.
SATURDAY NIGHT...MODERATE CONFIDENCE.
PREDOMINANTLY IFR CIGS ACROSS THE REGION WITH POCKETS OF MVFR
CIGS.
KBOS TAF...MODERATE CONFIDENCE.
EXPECTING TERMINAL TO BOUND BETWEEN VFR/MVFR CONDITIONS AS
RAINFALL INTENSITY CHANGES...WITH MVFR DOMINATING LATER THIS
EVENING. MODERATE CONFIDENCE IN IFR CIGS OVERNIGHT WITH SLIGHTLY
LOWER CONFIDENCE OF VLIFR AROUND MIDNIGHT INTO 29/12Z.
KBDL TAF...MODERATE CONFIDENCE.
PRIMARILY IFR TO START...WITH BRIEF PERIODS OF MVFR THIS
AFTERNOON. FIRST BATCH OF RAIN MOVES OFF THIS AFTERNOON...THEN A
SECOND AREA OF RAIN MOVES UP THE COAST TONIGHT. CEILINGS SHOULD
HOLD AROUND 1000-1500 FEET THROUGH THE PERIOD.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY INTO MONDAY...
MODERATE CONFIDENCE. INITALLY...MVFR/VFR CIGS SHOULD BE IMPACTING
TERMINALS E OF THE CT RVR VLY WITH SHRA. MAY SEE SOME INTERMITTENT
IFR VSBY IMPACTS. GRADUALLY THRU SUNDAY CONDITIONS WILL IMPROVE AS
NLY FLOW VEERS OUT OF THE W/SW. CIGS LIFT AND VFR PREVAILS...YET
THERE REMAINS A SLIGHT POSSIBILITY FOR RENEWED SHRA AND ATTENDANT
IMPACTS SUNDAY NGT...LOW CONFIDENCE. AS FOR MONDAY...GRADUAL
IMPROVEMENT CONTINUES. MAY SEE GUSTS UP TO 15-20 KTS OUT OF THE SW
/UP TO 25 KTS PSBL FOR TERMINALS ALONG THE S COAST/.
TUESDAY THROUGH WEDNESDAY...
LOW TO MODERATE CONFIDENCE. ADDITIONAL WET WX DISTURBANCE TRANSLATE
FROM THE MID-ATLANTIC NEWD JUST S OF NEW ENGLAND /OFFSHORE/.
ANTICIPATING A STALLED FRONTAL BOUNDARY JUST S OF NEW ENGLAND
RESULTING IN VRB WINDS ALONG THE S COAST...BUT A MORE N/NELY FLOW
THRU THE INTERIOR. LOWEST OF CIGS ACCORDINGLY ALONG THE S COAST...
HIGHER N INTO INTERIOR NEW ENGLAND. ANTICIPATING A MIX OF MVFR/VFR
CIGS WITH SHRA. PERHAPS SOME VSBY IMPACTS.
&&
.MARINE...
CONTINUING SMALL CRAFT ADVISORIES FOR MOST OF THE COASTAL WATERS
AS A LOW PRESSURE MOVES ACROSS THE REGION OVERNIGHT. COULD SEE
SOME GUSTS UP TO 25 KT BEFORE THE CENTER OF THE LOW PRESSURE
ARRIVES. THE EASTERLY FLOW COULD ALSO GENERATE 5 FT SEAS AS
WELL...ESPECIALLY ACROSS THE OUTER COASTAL WATERS. WINDS AND SEAS
START TO DIMINISH LATE TONIGHT...AND SHOULD BE BELOW SMALL CRAFT
ADVISORY LEVELS SATURDAY AFTERNOON.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY INTO MONDAY...
AS SHOWERS LIFT OUT OF THE RGN AND SKIES BEGIN TO BREAK...WILL SEE
AN ENHANCEMENT OF SWLY FLOW INTO MONDAY WITH GUSTS UP TO 25 KTS PSBL
FOR THE S WATERS. WHILE VSBY WILL IMPROVE...WAVE HEIGHTS ARE
EXPECTED TO BUILD UP TO 5 FT FOR THE S/SE WATERS.
TUESDAY INTO WEDNESDAY...
WAVE HEIGHTS OF 5 FT LESSEN ALONG THE S/SE WATERS GRADUALLY THRU
TUES. WILL SEE A FRONTAL BOUNDARY LIFT N AND STALL JUST OFFSHORE OF
NEW ENGLAND RESULTING IN LGT PREVAILING N/NELY FLOW. SHOWERS WILL BE
ON THE INCREASE AS A SERIES OF DISTURBANCES TRANSLATE ALONG THE
STALLED FRONTAL BOUNDARY...VSBY IMPACTS WITH HEAVIER SHOWERS WILL BE
PSBL. PATCHY FOG ALSO PSBL.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
ANZ232>234.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ231.
SMALL CRAFT ADVISORY UNTIL 3 AM EDT SATURDAY FOR ANZ235-237-
255-256.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ250-251-
254.
&&
$$
SYNOPSIS...BELK/SIPPRELL
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...SIPPRELL
AVIATION...BELK/SIPPRELL
MARINE...BELK/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
242 PM EDT FRI SEP 28 2012
.SYNOPSIS...
HIGH PRESSURE MOVES EAST THROUGH THE MARITIMES TODAY WHILE LOW
PRESSURE APPROACHES FROM THE WEST. THIS WILL BRING TWO PERIODS OF
APPRECIABLE RAINFALL TO THE AREA TODAY AND TONIGHT. THIS LOW
PRESSURE WILL EXIT THE REGION SATURDAY...BUT LOW CLOUDS AND
SPOTTY DRIZZLE WILL LINGER. ANOTHER LOW PRESSURE WILL APPROACH
FROM THE SOUTH SUNDAY NIGHT AND MONDAY...BRINGING MORE RAIN TO THE
AREA. YET ANOTHER WEAK LOW MAY SCRAPE BY TO THE SOUTH DURING
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
215 PM UPDATE...
28/15Z RAP MODEL HAD AN EXCELLENT HANDLE ON LOCATION AND TIMING OF
PRECIPITATION ACROSS SOUTHERN NEW ENGLAND EARLY THIS AFTERNOON.
HAD THE FRONTAL BOUNDARY BETWEEN NORWOOD AND MARSHFIELD MA...
EXTENDING SOUTHWEST ACROSS RI TO BE BETWEEN WILLIMANTIC CT AND
WESTERLY RI. THIS SHOULD BE THE FOCUS FOR THE HEAVIEST RAINFALL
LATER THIS AFTERNOON AND EVENING.
NOT MUCH SURFACE-BASED INSTABILITY TO WORK WITH ACROSS SOUTHERN
NEW ENGLAND AND THE BEST WIND SHEAR REMAINS TO THE SOUTH AS WELL.
WE HAVE NOTICED THE STRONGEST CONVECTION ACROSS CONTINUES TO
BACK-BUILD ACROSS LONG ISLAND SOUND...ANOTHER INDICATION OF THE
WEAK INSTABILITY ACROSS OUR REGION. THAT SAID...CANNOT COMPLETELY
RULE OUT A THUNDERSTORM LATER THIS AFTERNOON ACROSS PORTIONS OF RI
AND SOUTHEAST MA. PRECIPITABLE WATER CONTINUES TO BE OVER 2
INCHES...SO LOCALLY HEAVY DOWNPOURS WILL ALSO BE A POSSIBILITY.
DO NOT HAVE A LOT OF FAITH IN THE TIMING DETAILS OF THE 28/12Z
GUIDANCE. AS SUCH FAVORED A BLEND OF THE AVAILABLE GUIDANCE FOR
TIMING THE PRECIPITATION. EXPECTING ONE AREA OF ISENTROPIC LIFT ON
TE 295K AND 300K SURFACES TO MOVE OFFSHORE AND NORTH OF SOUTHERN
NEW ENGLAND OVERNIGHT. THIS SHOULD BRING IN A RELATIVE DRY PERIOD
LATE TONIGHT...ESPECIALLY ACROSS THE WESTERN HALF OF SOUTHERN NEW
ENGLAND.
TEMPERATURES NOT EXPECTED TO MOVE MUCH FROM PRESENT LEVELS. USED A
BLEND OF THE MOS GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
EXPECTING A BROAD SURFACE TROUGH TO LONGER ACROSS THE COAST OF
SOUTHERN NEW ENGLAND SATURDAY INTO SATURDAY NIGHT. CANNOT RULE OUT
SOME AREAS OF RAIN AS THE AIRMASS DOES NOT DRY OUT APPRECIABLY.
AGAIN CONFIDENCE IN THE TIMING IS LOW. DO EXPECT THE GREATEST RISK
OF RAINFALL TO BE ALONG THE EAST COAST OF MA AND THE MA COASTAL
WATERS.
USED A BLEND OF THE MOS GUIDANCE FOR TEMPERATURES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODEL SOLUTIONS GIVE GOOD RESULTS ON THE OVERALL UPPER
LEVEL PATTERN...ESPECIALLY WITH THE MOVEMENT OF THE H5 CLOSED LOW
OUT OF THE GREAT LAKES INTO NORTHERN NEW ENGLAND THROUGH THIS
WEEKEND INTO EARLY NEXT WEEK. HOWEVER...MODELS STILL HAVING
DIFFICULTIES WITH THE SURFACE FEATURES...THOUGH STILL SIGNALING
UNSETTLED WEATHER INTO MONDAY. NOW THOUGH...SEVERAL MEMBERS
INCLUDING THE ECMWF AND GGEM STARTING TO SIGNAL YET ANOTHER LOW
TRYING TO RIDE OUT OF THE GULF COAST ACROSS THE REGION TUESDAY ON
THE CONTINUED SW UPPER FLOW. NOTED THAT THE 00Z OP GFS RUN BECOMING
AN OUTLIER BEYOND MONDAY WITH THIS LOW. LEANED TOWARD A GFS/EC/EC
ENSEMBLE BLEND EARLY...THEN MORE TOWARD THE EC LATER IN THE PACKAGE.
DETAILS...
SUNDAY...
STALLED FRONT MEANDERS ACROSS THE REGION WHILE A WEAK WAVE
APPROACHES LATE SAT NIGHT/SUN. WENT ALONG WITH LOW LIKELY POPS
ACROSS RI/SE MA WHERE BEST LIFT/LL MOISTURE ARE. WITH FAIRLY GOOD
E-NE FLOW IN PLACE...HAVE MENTIONED PATCHY DRIZZLE FOR SAT
NIGHT/EARLY SUN AS WELL. BEST PW/S REMAIN CLOSE TO CAPE COD AND
OFFSHORE...AROUND 1.5 INCHES...BUT COULD STILL SEE A COUPLE OF
BRIEF HEAVY DOWNPOURS ACROSS EASTERN AREAS WHEN BEST LIFT MOVES
THROUGH. WINDS VEER AROUND TO S DURING SUNDAY...SO COULD SEE TEMPS
RISE TO THE 60S...MAYBE TOUCHING 70 ACROSS THE CT VALLEY AWAY FROM
BEST LIFT/LL MOISTURE FEED.
SUNDAY NIGHT-MONDAY...
GFS STARTS TO LINGER AWAY FROM MOST OTHER SOLUTIONS AS IT TRIES TO
OPEN UP THE H5 CUTOFF FASTER THAN THE GGEM/ECMWF SOLUTIONS. STILL
NOTING MAINLY A S-SW UPPER FLOW CONTINUING...ALONG WITH STALLED
FRONT WAVERING CLOSE TO OR JUST S OF THE REGION. BOTH GGEM AND EC
INDICATING ANOTHER WEAK WAVE MOVING ACROSS EASTERN AREAS LATE SUN
NIGHT/MONDAY MORNING WITH ANOTHER ROUND OF SHOWERS AND PATCHY
DRIZZLE/FOG. MAY START TO SEE CONDITIONS DRY OUT SOMEWHAT OVER W
MA/N CENTRAL CT/SW NH DURING THE AFTERNOON. DAYTIME HIGHS MAY BE A
FEW DEGS HIGHER THAN SATURDAY...POSSIBLY INTO THE LOWER 70S IN SOME
SPOTS AS WINDS SHIFT TO S-SW AND PICK UP A BIT.
MONDAY NIGHT AND TUESDAY...
GGEM/ECMWF MODELS IN PRETTY GOOD AGREEMENT IN BRINGING YET ANOTHER
WAVE ON FRONT...WHICH WILL REMAIN JUST S OF THE REGION. BIG QUESTION
AT THIS POINT WILL BE HOW FAR N WILL THIS LOW TRACK OUT OF THE GULF
COAST STATES. EC TRIES TO BRING LOW ACROSS CAPE COD DURING TUESDAY
SO HAVE ADDED LOW CHANCE POPS FOR THE S COAST. LOW TO MODERATE
CONFIDENCE ON THIS FEATURE AT THIS TIME...HOWEVER.
TUESDAY NIGHT THROUGH THURSDAY...
TIMING ISSUES ABOUND DURING THIS TIMEFRAME...AND EVEN HOW THE
NORTHERN STREAM INTERACTS WITH SOUTHERN STREAM ENERGY. AT THIS
POINT...HAVE KEPT SLIGHT CHANCE POPS GOING THROUGH AT LEAST
WEDNESDAY AS EC AND GGEM TRY TO KEEP MOISTURE PLUME ACROSS MAINLY S
COASTAL AREAS BUT UNCERTAIN IF THIS WILL SET UP AS WELL AS HOW FAR
N. MAY DRY THINGS OUT ACROSS N MA/S NH DURING THURSDAY. RATHER LOW
CONFIDENCE ON THIS PORTION OF THE FORECAST.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
SHORT TERM...
THROUGH 00Z...MODERATE CONFIDENCE. TIMING OF RAIN AND LOWER CLOUDS
CONTINUES TO BE PROBLEMATIC FOR SOME TERMINALS. DO EXPECT IFR
CONDITIONS TO PREVAIL LATE THIS AFTERNOON ACROSS THE
INTERIOR...WITH VFR TO MVFR CONDITIONS ACROSS THE CAPE AND
ISLANDS.
TONIGHT...MODERATE TO HIGH CONFIDENCE.
ONE BATCH OF RAIN MOVES OFF...A SECOND MOVES UP FROM THE SOUTH.
EITHER WAY...EXPECTING CIGS TO REMAIN MVFR WITH AREAS OF IFR IN
RAIN AND FOG. VSBYS ALSO MVFR WITH AREAS OF IFR IN HEAVIER RAIN
AREAS. SOME POTENTIAL FOR TSTMS TO DEVELOP...MAINLY ALONG THE
SOUTH COAST AND THE COASTAL PLAIN.
SATURDAY...MODERATE CONFIDENCE.
COASTAL LOW PRESSURE PASSES AND MOVES OFF THROUGH THE GULF OF
MAINE. DIMINISHING COVERAGE OF RAIN. VSBYS IMPROVE ESPECIALLY IN
THE AFTERNOON. CEILINGS MAY IMPROVE...BUT LESS CERTAIN. POTENTIAL
FOR LINGERING MVFR CIGS IN EASTERN MA DURING THE AFTERNOON.
SATURDAY NIGHT...MODERATE CONFIDENCE.
PREDOMINANTLY IFR CIGS ACROSS THE REGION WITH POCKETS OF MVFR
CIGS.
KBOS TAF...MODERATE CONFIDENCE.
EXPECTING TERMINAL TO BOUND BETWEEN VFR/MVFR CONDITIONS AS
RAINFALL INTENSITY CHANGES...WITH MVFR DOMINATING LATER THIS
EVENING. MODERATE CONFIDENCE IN IFR CIGS OVERNIGHT WITH SLIGHTLY
LOWER CONFIDENCE OF VLIFR AROUND MIDNIGHT INTO 29/12Z.
KBDL TAF...MODERATE CONFIDENCE.
PRIMARILY IFR TO START...WITH BRIEF PERIODS OF MVFR THIS
AFTERNOON. FIRST BATCH OF RAIN MOVES OFF THIS AFTERNOON...THEN A
SECOND AREA OF RAIN MOVES UP THE COAST TONIGHT. CEILINGS SHOULD
HOLD AROUND 1000-1500 FEET THROUGH THE PERIOD.
OUTLOOK...SUNDAY THROUGH TUESDAY...
SUNDAY...MODERATE CONFIDENCE. MAINLY MVFR/VFR CIGS. SCT
SHOWERS/PATCHY DRZL AND FOG ACROSS MOST OF THE REGION...WITH BEST
CHANCE ACROSS RI/E MA LATE SAT NIGHT/SUN. LOW-MODERATE PROB OF IFR
CIGS/VSBYS LATE SAT NIGHT IN FOG/DRZL PATCHES.
SUNDAY NIGHT-MONDAY...MODERATE CONFIDENCE.
EXPECT MVFR-VFR CIGS/VSBYS IN SCT SHOWERS/PATCHY DRZL/FOG. ANOTHER
LOW MOVES ALONG PASSING FRONT LATE SUN NIGHT/MON MORNING WITH
SHOWERS LIKELY ACROSS RI/E MA. LOCAL IFR VSBYS POSSIBLE IN ANY BRIEF
HEAVY DOWNPOURS. SW WINDS MAY GUST TO UP TO 20 KT ON THE S COAST
DURING MON.
MONDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.
SHOULD BE MAINLY VFR MON NIGHT WITH PATCHY MVFR-IFR VSBYS IN PATCHY
FOG. YET ANOTHER LOW MOVES S OF THE REGION...WHICH MAY BRING SCT
SHOWERS ACROSS RI/SE MA WITH LOCAL MVFR CIGS/VSBYS.
&&
.MARINE...
TODAY...
INCREASING SOUTHEAST WINDS AS LOW PRESSURE ROLLS ACROSS FROM THE
OHIO VALLEY. WINDS JUST OFF THE SURFACE WILL REACH 20-25
KNOTS...WITH CONFIDENCE THAT SOME OR ALL OF THIS WILL REACH THE
SURFACE THIS AFTERNOON...ESPECIALLY IN ANY RAIN. THE WIND WILL
SERVE TO BUILD SEAS WITH 5 FOOT VALUES ON THE OUTER WATERS. SMALL
CRAFT ADVISORY CONTINUES...FOR THE SOUTHERN WATERS THIS MORNING
AND FOR MOST WATERS THIS AFTERNOON.
TONIGHT...
AS THE CENTER OF LOW PRESSURE MOVES UP OVER THE WATERS...THE
DIMINISHING PRESSURE GRADIENT WILL ALLOW WINDS TO DIMINISH AS
WELL. SMALL CRAFT ADVISORY CONTINUES...WITH SMALL ADJUSTMENTS TO
ENDING TIMES AS THE WINDS AND SEAS DIMINISH OVERNIGHT.
SATURDAY...
WINDS AND SEAS DIMINISH WITH VALUES EXPECTED TO REMAIN BELOW SMALL
CRAFT THRESHOLDS.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT THROUGH SUNDAY NIGHT...MODERATE CONFIDENCE.
WINDS EXPECTED TO REMAIN BELOW 15 KT...MAINLY FROM THE E-NE THOUGH
WILL BE SHIFTING AS LOW PRES MOVES ACROSS THE EASTERN WATERS SUNDAY
NIGHT. SEAS WILL ALSO REMAIN BELOW SMALL CRAFT CRITERIA. VSBY
RESTRICTIONS IN SCATTERED SHOWERS ALONG WITH PATCHY RAIN AND
NIGHTTIME DRIZZLE.
MONDAY AND TUESDAY...MODERATE CONFIDENCE.
SW WINDS PICK UP ON MONDAY...GUSTS UP TO 20 KT. SEAS MAY BUILD TO 5
FT ON THE SOUTHERN OUTER WATERS. WINDS DIMINISH MON NIGHT INTO
TUESDAY. ANOTHER LOW WILL SCRAPE ACROSS THE SOUTHERN WATERS
TUE...WITH SOME VSBY RESTRICTIONS IN SCT SHOWERS/PATCHY FOG.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
ANZ232>234.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ231.
SMALL CRAFT ADVISORY UNTIL 3 AM EDT SATURDAY FOR ANZ235-237-
255-256.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ250-251-
254.
&&
$$
SYNOPSIS...BELK/EVT
NEAR TERM...BELK/EVT
SHORT TERM...BELK
LONG TERM...EVT
AVIATION...BELK/EVT
MARINE...BELK/EVT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1024 AM EDT FRI SEP 28 2012
.SYNOPSIS...
HIGH PRESSURE MOVES EAST THROUGH THE MARITIMES TODAY WHILE LOW
PRESSURE APPROACHES FROM THE WEST. THIS WILL BRING TWO PERIODS OF
APPRECIABLE RAINFALL TO THE AREA TODAY AND TONIGHT. THE LOW WILL
EXIT THE REGION SATURDAY BUT LOW CLOUDS AND SPOTTY DRIZZLE WILL
LINGER. ANOTHER LOW WILL APPROACH FROM THE SOUTH SUNDAY NIGHT AND
MONDAY...BRINGING MORE RAIN TO THE AREA. YET ANOTHER WEAK LOW MAY
SCRAPE BY TO THE SOUTH DURING TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1015 AM UPDATE...
AREA OF RAIN MOVING ACROSS MOST OF THE REGION AT 15Z. LIGHT E-NE
WINDS CONTINUE. NOTING SOME SPOTTY HIGHER REFLECTIVITIES ON NE
88D REGIONAL MOSAIC RADAR...SO WILL SEE SOME LOCALIZED BRIEF
DOWNPOURS INTO THIS AFTERNOON.
UPDATED WINDS TO HAVE A MORE NORTHERLY COMPONENT BASED ON LATEST
OBSERVATIONS AND HRRR MODEL. TEMPS...DEW POINTS AND POPS LOOK ON TRACK.
PREVIOUS DISCUSSION...
SOUTHEAST LOW LEVEL JET LIFTS ACROSS SOUTHERN NEW ENGLAND
TODAY...SUPPORTING ISENTROPIC LIFT OVER SOUTHERN NEW ENGLAND MUCH OF
THE DAY. THE AREAS OF STRONGEST LIFT AND STRONGEST FRONTOGENETIC
FORCING ARE BROUGHT ACROSS CT AND INTERIOR MASS AND SOUTHERN NH.
PRECIPITABLE WATER VALUES CONTINUE TO BE ADVERTISED AT 1.5 INCHES.
THE FORECAST RUNS WITH CATEGORICAL POPS FOR RAIN AND QPF VALUES OF
0.5 TO 1.0 INCHES.
CLOUDS/PCPN AND LOW LEVEL EAST FLOW SHOULD KEEP TEMPS FROM
CLIMBING TOO FAR TODAY. WE USED A BLEND OF MOS WHICH YIELDS MAX
TEMPS IN THE MID 50S TO MID 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
ONE AREA OF ISENTROPIC FORCING MOVES OFF THROUGH NORTHERN NEW
ENGLAND THIS EVENING. MEANWHILE THE MAIN SURFACE LOW TURNS THE
CORNER AT THE COAST AND MOVES NORTHEAST TOWARD COASTAL NEW
ENGLAND. THIS BRINGS A SECOND AREA OF FRONTOGENETIC FORCING UP
ACROSS THE COASTAL PLAIN DURING TONIGHT. STABILITY VALUES DIMINISH
AS THE LOW APPROACHES...WITH LI VALUES SUB ZERO MAINLY OVER RI AND
EASTERN MASS. WE HAVE MAINTAINED A CHANCE OF THUNDER IN THESE
AREAS DURING THE NIGHT.
EVEN WITH THE BREAK BETWEEN AREAS OF FORCING...THE MOIST EAST FLOW
SHOULD SUPPORT CLOUDS/FOG AND POSSIBLY SOME DRIZZLE.
SATURDAY...
LOW PRESSURE WAVE MOVES OFF TO THE NORTHEAST BY SATURDAY
AFTERNOON. EXPECT CONTINUED RAIN IN THE MORNING BUT DIMINISHING AS
THE LOW MOVES OFF. NOT SURE ABOUT SUBSTANTIAL DRYING OF THE
AIRMASS...SO WILL MAINTAIN MOSTLY CLOUDY SKIES THROUGH THE DAY.
TEMPS ARE A BLEND OF MOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODEL SOLUTIONS GIVE GOOD RESULTS ON THE OVERALL UPPER
LEVEL PATTERN...ESPECIALLY WITH THE MOVEMENT OF THE H5 CLOSED LOW
OUT OF THE GREAT LAKES INTO NORTHERN NEW ENGLAND THROUGH THIS
WEEKEND INTO EARLY NEXT WEEK. HOWEVER...MODELS STILL HAVING
DIFFICULTIES WITH THE SURFACE FEATURES...THOUGH STILL SIGNALING
UNSETTLED WEATHER INTO MONDAY. NOW THOUGH...SEVERAL MEMBERS
INCLUDING THE ECMWF AND GGEM STARTING TO SIGNAL YET ANOTHER LOW
TRYING TO RIDE OUT OF THE GULF COAST ACROSS THE REGION TUESDAY ON
THE CONTINUED SW UPPER FLOW. NOTED THAT THE 00Z OP GFS RUN BECOMING
AN OUTLIER BEYOND MONDAY WITH THIS LOW. LEANED TOWARD A GFS/EC/EC
ENSEMBLE BLEND EARLY...THEN MORE TOWARD THE EC LATER IN THE PACKAGE.
DETAILS...
SATURDAY NIGHT-SUNDAY...
STALLED FRONT MEANDERS ACROSS THE REGION WHILE A WEAK WAVE
APPROACHES LATE SAT NIGHT/SUN. WENT ALONG WITH LOW LIKELY POPS
ACROSS RI/SE MA WHERE BEST LIFT/LL MOISTURE ARE. WITH FAIRLY GOOD
E-NE FLOW IN PLACE...HAVE MENTIONED PATCHY DRIZZLE FOR SAT
NIGHT/EARLY SUN AS WELL. BEST PW/S REMAIN CLOSE TO CAPE COD AND
OFFSHORE...AROUND 1.5 INCHES...BUT COULD STILL SEE A COUPLE OF BRIEF
HEAVY DOWNPOURS ACROSS EASTERN AREAS WHEN BEST LIFT MOVES THROUGH.
WINDS VEER AROUND TO S DURING SUNDAY...SO COULD SEE TEMPS RISE TO
THE 60S...MAYBE TOUCHING 70 ACROSS THE CT VALLEY AWAY FROM BEST
LIFT/LL MOISTURE FEED.
SUNDAY NIGHT-MONDAY...
GFS STARTS TO LINGER AWAY FROM MOST OTHER SOLUTIONS AS IT TRIES TO
OPEN UP THE H5 CUTOFF FASTER THAN THE GGEM/ECWMF SOLUTIONS. STILL
NOTING MAINLY A S-SW UPPER FLOW CONTINUING...ALONG WITH STALLED
FRONT WAVERING CLOSE TO OR JUST S OF THE REGION. BOTH GGEM AND EC
INDICATING ANOTHER WEAK WAVE MOVING ACROSS EASTERN AREAS LATE SUN
NIGHT/MONDAY MORNING WITH ANOTHER ROUND OF SHOWERS AND PATCHY
DRIZZLE/FOG. MAY START TO SEE CONDITIONS DRY OUT SOMEWHAT OVER W
MA/N CENTRAL CT/SW NH DURING THE AFTERNOON. DAYTIME HIGHS MAY BE A
FEW DEGS HIGHER THAN SATURDAY...POSSIBLY INTO THE LOWER 70S IN SOME
SPOTS AS WINDS SHIFT TO S-SW AND PICK UP A BIT.
MONDAY NIGHT AND TUESDAY...
GGEM/ECWMF MODELS IN PRETTY GOOD AGREEMENT IN BRINGING YET ANOTHER
WAVE ON FRONT...WHICH WILL REMAIN JUST S OF THE REGION. BIG QUESTION
AT THIS POINT WILL BE HOW FAR N WILL THIS LOW TRACK OUT OF THE GULF
COAST STATES. EC TRIES TO BRING LOW ACROSS CAPE COD DURING TUESDAY
SO HAVE ADDED LOW CHANCE POPS FOR THE S COAST. LOW TO MODERATE
CONFIDENCE ON THIS FEATURE AT THIS TIME...HOWEVER.
TUESDAY NIGHT THROUGH THURSDAY...
TIMING ISSUES ABOUND DURING THIS TIMEFRAME...AND EVEN HOW THE
NORTHERN STREAM INTERACTS WITH SOUTHERN STREAM ENERGY. AT THIS
POINT...HAVE KEPT SLIGHT CHANCE POPS GOING THROUGH AT LEAST
WEDNESDAY AS EC AND GGEM TRY TO KEEP MOISTURE PLUME ACROSS MAINLY S
COASTAL AREAS BUT UNCERTAIN IF THIS WILL SET UP AS WELL AS HOW FAR
N. MAY DRY THINGS OUT ACROSS N MA/S NH DURING THURSDAY. RATHER LOW
CONFIDENCE ON THIS PORTION OF THE FORECAST.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
SHORT TERM...
TODAY...MODERATE CONFIDENCE.
RAIN WILL CONTINUE TO CROSS THE REGION. NOTING A MIX OF CIG
CONDITIONS AT 15Z...BUT ANTICIPATE PRIIMARILY VFR TODAY SE
COAST...AND PERIODS OF MVFR CIGS/VSBYS ACROSS MUCH OF MA/N CT WITH
LOCALIZED IFR ESPECIALLY OVER THE HILLS OF WESTERN MA/N CT. VSBYS
WILL LOWER TO 3-4 MILES AND MAY DIP TO 1 1/2 MILES IN SPOTS.
INCREASING NE-E WINDS WITH GUSTS AROUND 20 KNOTS DURING THE LATE
AFTERNOON AND EVENING ESPECIALLY IN THE COASTAL PLAIN.
TONIGHT...MODERATE TO HIGH CONFIDENCE.
ONE BATCH OF RAIN MOVES OFF...A SECOND MOVES UP FROM THE SOUTH.
EITHER WAY...EXPECTING CIGS TO REMAIN MVFR WITH AREAS OF IFR IN RAIN
AND FOG. VSBYS ALSO MVFR WITH AREAS OF IFR IN HEAVIER RAIN AREAS.
SOME POTENTIAL FOR TSTMS TO DEVELOP...MAINLY ALONG THE SOUTH COAST
AND THE COASTAL PLAIN.
SATURDAY...MODERATE CONFIDENCE.
COASTAL LOW PRESSURE PASSES AND MOVES OFF THROUGH THE GULF OF
MAINE. DIMINISHING COVERAGE OF RAIN. VSBYS IMPROVE ESPECIALLY IN
THE AFTERNOON. CEILINGS MAY IMPROVE...BUT LESS CERTAIN. POTENTIAL
FOR LINGERING MVFR CIGS IN EASTERN MASS DURING THE AFTERNOON.
KBOS TAF...MODERATE CONFIDENCE.
CIGS/VSBYS REMAIN VFR THROUGH EARLY AFTERNOON...THEN LOWERING TO
MVFR AFTER 20Z. COULD BE A PERIOD OF IFR VSBYS IN HEAVIER RAIN LATE
AFTERNOON AND THEN A SECOND PERIOD OVERNIGHT. EAST WINDS TODAY AND
AT LEAST THE START OF TONIGHT...GUSTS TO 20 KNOTS POSSIBLE.
POTENTIAL FOR THUNDER TONIGHT AND EARLY SATURDAY AS COASTAL LOW
PRESSURE MOVES PAST.
KBDL TAF...MODERATE CONFIDENCE.
MIX OF IFR TO VFR CIGS IN -RA TO START...THEN ANTICIPATE PRIMARILY
MVFR CIGS. VSBYS LOWERING TO MVFR BY AFTERNOON. LOWER VSBYS IN
HEAVIER RAIN ARE POSSIBLE TOWARD MIDDAY AND THIS AFTERNOON. THIS
FIRST BATCH OF RAIN MOVES OFF DURING THE AFTERNOON...THEN A SECOND
AREA OF RAIN MOVES UP THE COAST TONIGHT. CEILINGS SHOULD HOLD
AROUND 1000-1500 FEET THROUGH THE PERIOD.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT-SUNDAY...MODERATE CONFIDENCE.
MAINLY MVFR/VFR CIGS. SCT SHOWERS/PATCHY DRZL AND FOG ACROSS MOST OF
THE REGION...WITH BEST CHANCE ACROSS RI/E MA LATE SAT NIGHT/SUN.
LOW-MODERATE PROB OF IFR CIGS/VSBYS LATE SAT NIGHT IN FOG/DRZL
PATCHES.
SUNDAY NIGHT-MONDAY...MODERATE CONFIDENCE.
EXPECT MVFR-VFR CIGS/VSBYS IN SCT SHOWERS/PATCHY DRZL/FOG. ANOTHER
LOW MOVES ALONG PASSING FRONT LATE SUN NIGHT/MON MORNING WITH
SHOWERS LIKELY ACROSS RI/E MA. LOCAL IFR VSBYS POSSIBLE IN ANY BRIEF
HEAVY DOWNPOURS. SW WINDS MAY GUST TO UP TO 20 KT ON THE S COAST
DURING MON.
MONDAY NIGHT INTO TUESDAY...MODERATE CONFIDENCE.
SHOULD BE MAINLY VFR MON NIGHT WITH PATCHY MVFR-IFR VSBYS IN PATCHY
FOG. YET ANOTHER LOW MOVES S OF THE REGION...WHICH MAY BRING SCT
SHOWERS ACROSS RI/SE MA WITH LOCAL MVFR CIGS/VSBYS.
&&
.MARINE...
TODAY...
INCREASING SOUTHEAST WINDS AS LOW PRESSURE ROLLS ACROSS FROM THE
OHIO VALLEY. WINDS JUST OFF THE SURFACE WILL REACH 20-25
KNOTS...WITH CONFIDENCE THAT SOME OR ALL OF THIS WILL REACH THE
SURFACE THIS AFTERNOON...ESPECIALLY IN ANY RAIN. THE WIND WILL
SERVE TO BUILD SEAS WITH 5 FOOT VALUES ON THE OUTER WATERS. SMALL
CRAFT ADVISORY CONTINUES...FOR THE SOUTHERN WATERS THIS MORNING
AND FOR MOST WATERS THIS AFTERNOON.
TONIGHT...
AS THE CENTER OF LOW PRESSURE MOVES UP OVER THE WATERS...THE
DIMINISHING PRESSURE GRADIENT WILL ALLOW WINDS TO DIMINISH AS
WELL. SMALL CRAFT ADVISORY CONTINUES...WITH SMALL ADJUSTMENTS TO
ENDING TIMES AS THE WINDS AND SEAS DIMINISH OVERNIGHT.
SATURDAY...
WINDS AND SEAS DIMINISH WITH VALUES EXPECTED TO REMAIN BELOW SMALL
CRAFT THRESHOLDS.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT THROUGH SUNDAY NIGHT...MODERATE CONFIDENCE.
WINDS EXPECTED TO REMAIN BELOW 15 KT...MAINLY FROM THE E-NE THOUGH
WILL BE SHIFTING AS LOW PRES MOVES ACROSS THE EASTERN WATERS SUNDAY
NIGHT. SEAS WILL ALSO REMAIN BELOW SMALL CRAFT CRITERIA. VSBY
RESTRICTIONS IN SCATTERED SHOWERS ALONG WITH PATCHY RAIN AND
NIGHTTIME DRIZZLE.
MONDAY AND TUESDAY...MODERATE CONFIDENCE.
SW WINDS PICK UP ON MONDAY...GUSTS UP TO 20 KT. SEAS MAY BUILD TO 5
FT ON THE SOUTHERN OUTER WATERS. WINDS DIMINISH MON NIGHT INTO
TUESDAY. ANOTHER LOW WILL SCRAPE ACROSS THE SOUTHERN WATERS
TUE...WITH SOME VSBY RESTRICTIONS IN SCT SHOWERS/PATCHY FOG.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
ANZ232>234.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR ANZ231.
SMALL CRAFT ADVISORY UNTIL 3 AM EDT SATURDAY FOR ANZ235-237-
255-256.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR ANZ250-251-
254.
&&
$$
SYNOPSIS...WTB/EVT
NEAR TERM...WTB/EVT/NMB
SHORT TERM...WTB
LONG TERM...EVT
AVIATION...WTB/EVT/NMB
MARINE...WTB/EVT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
156 AM EDT FRI SEP 28 2012
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN JUST TO THE SOUTH THROUGH TONIGHT.
LOW PRESSURE WILL MOVE SLOWLY EAST ALONG THE FRONT AND WILL CROSS
THE REGION THIS AFTERNOON AND NIGHT. THE LOW WILL THEN MOVE AWAY ON
SATURDAY. ANOTHER WEAK LOW WILL PASS TO THE NORTHEAST SUNDAY NIGHT
INTO MONDAY. YET ANOTHER LOW WILL PASS TO THE SOUTHEAST TUESDAY
INTO TUESDAY NIGHT...FOLLOWED BY HIGH PRESSURE BUILDING IN FOR
WEDNESDAY. ANOTHER LOW PRESSURE SYSTEM COULD AFFECT THE REGION AT
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
JUST MADE SOME MINOR ADJUSTMENTS TO TEMPS TO MATCH CURRENT
TRENDS...OTHERWISE REST OF FORECAST IS ON TRACK.
A WAVE OF LOW PRESSURE ALONG A STATIONARY FRONT TO THE SOUTH OF
THE REGION IS APPROACHING. THIS WILL BRING THE MOST
SYNOPTIC FORCING AFTER 6Z AS NOTED FROM 850-500MB Q VECTOR
CONVERGENCE WITH THE APPROACHING SHORTWAVE AND ATTENDANT INCREASE
IN LAYER PW VALUES TO AROUND 1.5 INCHES. IN ADDITION...PRETTY
DECENT ISENTROPIC LIFT HAS BEEN NOTED IN THE MODEL FIELDS ALONG
THE 300 K ISENTROPE STARTING AT 6Z AND CONTINUING INTO EARLY
FRIDAY MORNING. LATEST HRRR MODEL REFLECTIVITY FIELDS SUGGEST
RAIN SPREADS ACROSS THE REMAINDER OF THE AREA GRADUALLY EARLY THIS
MORNING. THIS SEEMS TO FIT WITH LINEAR EXTRAPOLATIONS OF CURRENT
RADAR REFLECTIVITY. WILL MAINTAIN HEAVY RAIN MENTION.
ALSO...THERE IS AGREEMENT WITH THE MODELS OF MUCAPE OF A FEW
HUNDRED J/KG SO MENTIONED ISOLATED THUNDERSTORMS AS WELL...BUT
RESTRICTED THIS TOWARDS SOUTHWESTERN COASTAL PORTIONS OF THE
FORECAST REGION.
MIN TEMPS WERE SLIGHTLY INCREASED TOWARDS THE NORTHERN HALF OF THE
FORECAST AREA BUT OVERALL...NO SIGNIFICANT CHANGES WERE MADE TO
THESE AND THE DEWPOINTS FIELDS. STILL LOOKING AT A GENERAL RANGE
OF MIN TEMPS FROM THE LOWER/MID 50S TO THE LOWER 60S WHICH IS
CONSISTENT WITH A MAV/MET BLEND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
NWP GUIDANCE SUGGESTS HEAVIEST RAIN VIA BEST ISENTROPIC/OROGRAPHIC
LIFT AND FRONTOGENETIC FORCING WILL INITIALLY BE FOCUSED MORE JUST
TO THE NORTH/WEST OF THE CWA INTO FRI MORNING...BUT EVEN SO NYC
METRO AND THE LOWER HUDSON VALLEY SHOULD RECEIVE ABOUT AN INCH OF
RAIN THROUGH MIDDAY FRI.
AS THE WEAK LOW MOVES ACROSS FRI AFTERNOON...COMBO OF GOOD
MOISTURE TRANSPORT...ISENTROPIC LIFT AND INSTABILITY JUST TO ITS
EAST WITH MUCAPE INCREASING TO 500-1000 J/KG SHOULD BE ENOUGH TO
SUPPORT MODERATE TO LOCALLY HEAVY RAIN AND TSTMS. MOST MODELS ARE
UNDERPLAYING THIS...EXCEPT FOR THE 12Z RGEM WHICH IS A VERY WET
OUTLIER WITH UP TO 2 INCHES TOTAL QPF ACROSS SOUTHERN CT FRI
AFTERNOON. NYC METRO AND COASTAL SECTIONS MAY GET INTO THE WARM
SECTOR...WHERE INSTABILITY WILL BE SFC-BASED AND WHERE A FEW GUSTY
TSTMS ARE POSSIBLE.
THIS COMBO OF GOOD MOISTURE TRANSPORT...LIFT AND INSTABILITY
SHOULD LINGER ACROSS LONG ISLAND AND SOUTHERN CT INTO THE
EVENING...THEN WANE AFTER MIDNIGHT. A SECOND ROUND OF
SHOWERS/TSTMS MAY BE POSSIBLE FOR LONG ISLAND AND SOUTHERN CT
LATE FRI NIGHT AS A STRONG MID LEVEL VORT MAX AND POSSIBLE INDUCED
SFC WAVE SWEEP ACROSS OR JUST TO THE SE. MODELS DISAGREE ON
TIMING/PLACEMENT...SO HAVE JUST CONTINUED A GENERIC CHANCE POP
DURING THAT TIME.
THERE IS A HIGH RISK OF RIP CURRENTS AT THE OCEAN BEACHES WEDNESDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
SOMEWHAT UNSETTLED..ALBEIT LIGHT PRECIPITATION IN THE LONG TERM AS
CUT OFF UPPER LEVEL LOW AND NEARLY STATIONARY COLD FRONT WELL OFF
THE EAST COAST ARE THE MAIN PLAYERS TO START OFF THE PERIOD. SURFACE
LOW PRESSURE ALONG THE STALLED FRONTAL BOUNDARY PUSHES AWAY FROM THE
AREA AS THE UPPER LEVEL LOW SITUATED BETWEEN THE HUDSON BAY AND THE
GREAT LAKES MOVES SOUTHWEST TOWARD THE GREAT LAKES ON SATURDAY. WITH
THE UPPER LOW IN THE VICINITY AND COLD POOL ALOFT...THERE WILL BE
SOME INSTABILITY SHOWERS ACROSS THE AREA...WITH THE BEST CHANCES
NORTH AND WEST OF THE NEW YORK METRO AREA.
A PIECE OF ENERGY FROM THE UPPER LEVEL LOW THEN SWINGS ACROSS THE
EASTERN GREAT LAKES AND TRACKS TO THE NORTHEAST SUNDAY INTO MONDAY.
THERE IS A GOOD DEAL OF UNCERTAINTY WITH THE TRACK OF THIS LOW. ALL
MODELS TRACK THIS LOW TO THE NORTH AND EAST OF THE AREA...BUT THE
ECMWF TRACKS THE LOW THROUGH CENTRAL NY...WHILE THE GFS TRACKS IT
ACROSS THE EASTERN GREAT LAKES...AND THE GEM IS CLOSER TO THE
ECMWF...BUT WEAKENS IT AS IT GETS ABSORBED INTO A COASTAL LOW. THE
ECMWF ALSO HAS THIS COASTAL LOW...BUT IT IS FARTHER OFFSHORE...MORE
ALIGNED WITH THE COLD FRONT...AND WEAKER. SO WENT WITH CHANCE POPS
DUE TO UNCERTAINTY.
HIGH PRESSURE BUILDS IN FOR MONDAY NIGHT. LOW PRESSURE FORMS ALONG
THE FRONTAL BOUNDARY OVER THE SOUTHEAST U.S. AND TRACKS NORTHEAST
MONDAY. ECMWF AND GEM TRACKS THE LOW SOUTH AND EAST OF THE
CWA...WITH A SOLID HALF INCH OF QPF...WHILE THE GFS IS MORE
SUPPRESSED WITH HIGH PRESSURE OVER THE REGION FOR TUESDAY. HIGH
PRESSURE BUILDS IN FOR TUESDAY NIGHT AND WEDNESDAY...WITH POSSIBLY
ANOTHER SYSTEM POISED TO AFFECT THE REGION AT THE END OF THE WEEK.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
A FRONTAL BOUNDARY SOUTH OF THE REGION WILL SLOWLY LIFT NORTH
TOWARDS THE REGION TODAY. A WAVE OF LOW PRESSURE...ON THE
FRONT...APPROACHES FROM THE WEST EARLY THIS MORNING...AND MOVES
THROUGH DURING THE DAY TODAY.
FORECAST CONFIDENCE IS LOW.
THE FORECAST...ESPECIALLY WINDS...WILL DEPEND ON THE TRACK OF THE
LOW AND ASSOCIATED WARM FRONT. THERE REMAINS UNCERTAINTY IN THE
FORECAST AS TO WHETHER OR NOT THE WARM FRONT MOVES ON SHORE FRIDAY
MORNING...AND IF IT DOES HOW FAR NORTH THE WARM FRONT WILL MOVE.
THERE IS ALSO A CHANCE THAT WINDS COULD GUST FOR A PERIOD THIS
MORNING. DEPENDING ON HOW FAR NORTH THE FRONT LIFTS...WILL ALSO
DEPENDS ON THE TRACK OF THE LOW.
CIGS WILL GRADUALLY LOWER TO 1500 TO 2500 FT.
MEANWHILE...VISIBILITIES WILL LOWER TO 3 TO 5 SM IN DEVELOPING
SHOWERS AND FOG...AND THEN LOWER TO AROUND 2 SM IN RAIN AND FOG
TOWARD 12Z OR SO. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS FRIDAY
MORNING...AROUND 12Z TO 18Z. NOT INCLUDED AT THIS TIME WITH THE
LOW PROBABILITY AND ISOLATED COVERAGE.
OUTLOOK FOR 06Z SAT-TUE...
.FRI NIGHT...MVFR CEILINGS AND VISIBILITIES IN SHOWERS. CONDITIONS
IMPROVING TOWARD SAT MORNING. LOW CONFIDENCE.
.SAT-TUE...GENERALLY VFR BUT MVFR OR LOWER CONDITIONS POSSIBLE AT
TIMES IN SHOWERS. LOW CONFIDENCE ON DETAILS.
&&
.MARINE...
FAIRLY TRANQUIL CONDITIONS WILL QUICKLY DETERIORATE EARLY THIS
MORNING AS WINDS INCREASE...BUILDING SEAS.
SCA REMAIN IN EFFECT FOR ALL WATERS. EASTERLY FLOW LOOKS TO
INCREASE TO 15-20 WITH GUSTS UP TO 25 KT DURING THIS TIME. OCEAN
SEAS SHOULD MAX OUT AT EITHER 6-7 FT...ABOUT 1 FT ABOVE 12Z
WAVEWATCH.
SCA CONDS SHOULD LINGER ON THE ERN OCEAN WATERS UNTIL ABOUT
MIDNIGHT FRI NIGHT...THEN QUIET CONDITIONS ARE EXPECTED.
&&
.HYDROLOGY...
UP TO 2 INCHES OF RAINFALL POSSIBLE THROUGH TONIGHT. THE HEAVIEST
RAIN WILL FALL MOSTLY NW OF THE LOW CENTER INITIALLY THIS MORNING...
FROM NYC METRO AND POINTS NORTH/WEST...BUT THEN HEAVY RAIN FOCUS
SHOULD SHIFT TO LONG ISLAND AND SOUTHERN CT IN THE AFTERNOON JUST
AHEAD OF THE LOW AS IT MOVES ACROSS. MAIN CONCERN IS FOR MINOR
FLOODING. ISOLD FLASH FLOODING COULD OCCUR WITH HEAVIEST TSTMS FRI
AFTERNOON AND EARLY EVENING ACROSS LONG ISLAND AND SOUTHERN
CT...BUT THIS THREAT APPEARS TOO LOW/ISOLD TO WARRANT A WATCH. A
STORM TOTAL GRAPHIC HAS BEEN POSTED TO THE WEB.
&&
.TIDES/COASTAL FLOODING...
COMBO OF HIGH ASTRONOMICAL HIGH TIDES WITH THE UPCOMING FULL MOON
PLUS ABOUT 1 TO 1.5 FT OF SURGE AHEAD OF THE LOW APPROACHING
THIS MORNING COULD LEAD TO ISOLATED MINOR COASTAL FLOODING AT THE
TIMES OF HIGH TIDE TONIGHT IN THE MOST VULNERABLE LOCATIONS ALONG
THE SOUTH SHORE BACK BAYS OF WRN LONG ISLAND...AND ALONG WRN LONG
ISLAND SOUND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO NOON EDT TODAY
FOR ANZ335-338-345.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EDT THIS
EVENING FOR ANZ330-340.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...
NEAR TERM...GOODMAN/JM/PW
SHORT TERM...GOODMAN
LONG TERM...
AVIATION...BC
MARINE...GOODMAN/PW
HYDROLOGY...GOODMAN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
105 AM EDT FRI SEP 28 2012
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN JUST TO THE SOUTH THROUGH TONIGHT.
LOW PRESSURE WILL MOVE SLOWLY EAST ALONG THE FRONT AND WILL CROSS
THE REGION THIS AFTERNOON AND NIGHT. THE LOW WILL THEN MOVE AWAY ON
SATURDAY. ANOTHER WEAK LOW WILL PASS TO THE NORTHEAST SUNDAY NIGHT
INTO MONDAY. YET ANOTHER LOW WILL PASS TO THE SOUTHEAST TUESDAY
INTO TUESDAY NIGHT...FOLLOWED BY HIGH PRESSURE BUILDING IN FOR
WEDNESDAY. ANOTHER LOW PRESSURE SYSTEM COULD AFFECT THE REGION AT
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
JUST MADE SOME MINOR ADJUSTMENTS TO TEMPS TO MATCH CURRENT
TRENDS...OTHERWISE REST OF FORECAST IS ON TRACK.
A WAVE OF LOW PRESSURE ALONG A STATIONARY FRONT TO THE SOUTH OF
THE REGION IS APPROACHING. THIS WILL BRING THE MOST
SYNOPTIC FORCING AFTER 6Z AS NOTED FROM 850-500MB Q VECTOR
CONVERGENCE WITH THE APPROACHING SHORTWAVE AND ATTENDANT INCREASE
IN LAYER PW VALUES TO AROUND 1.5 INCHES. IN ADDITION...PRETTY
DECENT ISENTROPIC LIFT HAS BEEN NOTED IN THE MODEL FIELDS ALONG
THE 300 K ISENTROPE STARTING AT 6Z AND CONTINUING INTO EARLY
FRIDAY MORNING. LATEST HRRR MODEL REFLECTIVITY FIELDS SUGGEST
RAIN SPREADS ACROSS THE REMAINDER OF THE AREA GRADUALLY EARLY THIS
MORNING. THIS SEEMS TO FIT WITH LINEAR EXTRAPOLATIONS OF CURRENT
RADAR REFLECTIVITY. WILL MAINTAIN HEAVY RAIN MENTION.
ALSO...THERE IS AGREEMENT WITH THE MODELS OF MUCAPE OF A FEW
HUNDRED J/KG SO MENTIONED ISOLATED THUNDERSTORMS AS WELL...BUT
RESTRICTED THIS TOWARDS SOUTHWESTERN COASTAL PORTIONS OF THE
FORECAST REGION.
MIN TEMPS WERE SLIGHTLY INCREASED TOWARDS THE NORTHERN HALF OF THE
FORECAST AREA BUT OVERALL...NO SIGNIFICANT CHANGES WERE MADE TO
THESE AND THE DEWPOINTS FIELDS. STILL LOOKING AT A GENERAL RANGE
OF MIN TEMPS FROM THE LOWER/MID 50S TO THE LOWER 60S WHICH IS
CONSISTENT WITH A MAV/MET BLEND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
NWP GUIDANCE SUGGESTS HEAVIEST RAIN VIA BEST ISENTROPIC/OROGRAPHIC
LIFT AND FRONTOGENETIC FORCING WILL INITIALLY BE FOCUSED MORE JUST
TO THE NORTH/WEST OF THE CWA INTO FRI MORNING...BUT EVEN SO NYC
METRO AND THE LOWER HUDSON VALLEY SHOULD RECEIVE ABOUT AN INCH OF
RAIN THROUGH MIDDAY FRI.
AS THE WEAK LOW MOVES ACROSS FRI AFTERNOON...COMBO OF GOOD
MOISTURE TRANSPORT...ISENTROPIC LIFT AND INSTABILITY JUST TO ITS
EAST WITH MUCAPE INCREASING TO 500-1000 J/KG SHOULD BE ENOUGH TO
SUPPORT MODERATE TO LOCALLY HEAVY RAIN AND TSTMS. MOST MODELS ARE
UNDERPLAYING THIS...EXCEPT FOR THE 12Z RGEM WHICH IS A VERY WET
OUTLIER WITH UP TO 2 INCHES TOTAL QPF ACROSS SOUTHERN CT FRI
AFTERNOON. NYC METRO AND COASTAL SECTIONS MAY GET INTO THE WARM
SECTOR...WHERE INSTABILITY WILL BE SFC-BASED AND WHERE A FEW GUSTY
TSTMS ARE POSSIBLE.
THIS COMBO OF GOOD MOISTURE TRANSPORT...LIFT AND INSTABILITY
SHOULD LINGER ACROSS LONG ISLAND AND SOUTHERN CT INTO THE
EVENING...THEN WANE AFTER MIDNIGHT. A SECOND ROUND OF
SHOWERS/TSTMS MAY BE POSSIBLE FOR LONG ISLAND AND SOUTHERN CT
LATE FRI NIGHT AS A STRONG MID LEVEL VORT MAX AND POSSIBLE INDUCED
SFC WAVE SWEEP ACROSS OR JUST TO THE SE. MODELS DISAGREE ON
TIMING/PLACEMENT...SO HAVE JUST CONTINUED A GENERIC CHANCE POP
DURING THAT TIME.
THERE IS A HIGH RISK OF RIP CURRENTS AT THE OCEAN BEACHES WEDNESDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
SOMEWHAT UNSETTLED..ALBEIT LIGHT PRECIPITATION IN THE LONG TERM AS
CUT OFF UPPER LEVEL LOW AND NEARLY STATIONARY COLD FRONT WELL OFF
THE EAST COAST ARE THE MAIN PLAYERS TO START OFF THE PERIOD. SURFACE
LOW PRESSURE ALONG THE STALLED FRONTAL BOUNDARY PUSHES AWAY FROM THE
AREA AS THE UPPER LEVEL LOW SITUATED BETWEEN THE HUDSON BAY AND THE
GREAT LAKES MOVES SOUTHWEST TOWARD THE GREAT LAKES ON SATURDAY. WITH
THE UPPER LOW IN THE VICINITY AND COLD POOL ALOFT...THERE WILL BE
SOME INSTABILITY SHOWERS ACROSS THE AREA...WITH THE BEST CHANCES
NORTH AND WEST OF THE NEW YORK METRO AREA.
A PIECE OF ENERGY FROM THE UPPER LEVEL LOW THEN SWINGS ACROSS THE
EASTERN GREAT LAKES AND TRACKS TO THE NORTHEAST SUNDAY INTO MONDAY.
THERE IS A GOOD DEAL OF UNCERTAINTY WITH THE TRACK OF THIS LOW. ALL
MODELS TRACK THIS LOW TO THE NORTH AND EAST OF THE AREA...BUT THE
ECMWF TRACKS THE LOW THROUGH CENTRAL NY...WHILE THE GFS TRACKS IT
ACROSS THE EASTERN GREAT LAKES...AND THE GEM IS CLOSER TO THE
ECMWF...BUT WEAKENS IT AS IT GETS ABSORBED INTO A COASTAL LOW. THE
ECMWF ALSO HAS THIS COASTAL LOW...BUT IT IS FARTHER OFFSHORE...MORE
ALIGNED WITH THE COLD FRONT...AND WEAKER. SO WENT WITH CHANCE POPS
DUE TO UNCERTAINTY.
HIGH PRESSURE BUILDS IN FOR MONDAY NIGHT. LOW PRESSURE FORMS ALONG
THE FRONTAL BOUNDARY OVER THE SOUTHEAST U.S. AND TRACKS NORTHEAST
MONDAY. ECMWF AND GEM TRACKS THE LOW SOUTH AND EAST OF THE
CWA...WITH A SOLID HALF INCH OF QPF...WHILE THE GFS IS MORE
SUPPRESSED WITH HIGH PRESSURE OVER THE REGION FOR TUESDAY. HIGH
PRESSURE BUILDS IN FOR TUESDAY NIGHT AND WEDNESDAY...WITH POSSIBLY
ANOTHER SYSTEM POISED TO AFFECT THE REGION AT THE END OF THE WEEK.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
A COLD FRONT WILL REMAIN JUST TO THE SOUTH TONIGHT. A WAVE OF LOW
PRESSURE...ON THE FRONT...APPROACHES FROM THE WEST OVERNIGHT...AND
MOVES THROUGH DURING THE FORECAST PERIOD.
FORECAST...ESPECIALLY WINDS AND GUSTS...WILL DEPEND ON THE TRACK OF
THE LOW AND ASSOCIATED WARM FRONT. THERE IS UNCERTAINTY IF THE WARM
FRONT MOVES ON SHORE FRIDAY MORNING...AND IF IT DOES HOW FAR NORTH
THE WARM FRONT WILL MOVE. FORECAST CONFIDENCE IS LOW.
VFR CONDITIONS LOWER WITH 1500 TO 2500 FT CEILINGS DEVELOPING.
VISIBILITIES WILL LOWER TO 3 TO 5 SM IN DEVELOPING SHOWERS AND
FOG...AND THEN LOWER TO AROUND 2 SM IN RAIN AND FOG TOWARD FRIDAY
MORNING. THERE IS A SLIGHT CHANCE OF THUNDERSTORMS FRIDAY
MORNING...AROUND 12Z TO 18Z. NOT INCLUDED AT THIS TIME WITH THE LOW
PROBABILITY AND ISOLATED COVERAGE.
OUTLOOK FOR 00Z SAT-TUE...
.FRI NIGHT...MVFR CEILINGS AND VISIBILITIES IN SHOWERS. CONDITIONS
IMPROVING TOWARD SAT MORNING. LOW CONFIDENCE.
.SAT-TUE...GENERALLY VFR BUT MVFR OR LOWER CONDITIONS POSSIBLE AT
TIMES IN SHOWERS. LOW CONFIDENCE ON DETAILS.
&&
.MARINE...
FAIRLY TRANQUIL CONDITIONS WILL QUICKLY DETERIORATE EARLY THIS
MORNING AS WINDS INCREASE...BUILDING SEAS.
SCA REMAIN IN EFFECT FOR ALL WATERS. EASTERLY FLOW LOOKS TO
INCREASE TO 15-20 WITH GUSTS UP TO 25 KT DURING THIS TIME. OCEAN
SEAS SHOULD MAX OUT AT EITHER 6-7 FT...ABOUT 1 FT ABOVE 12Z
WAVEWATCH.
SCA CONDS SHOULD LINGER ON THE ERN OCEAN WATERS UNTIL ABOUT
MIDNIGHT FRI NIGHT...THEN QUIET CONDITIONS ARE EXPECTED.
&&
.HYDROLOGY...
UP TO 2 INCHES OF RAINFALL POSSIBLE THROUGH TONIGHT. THE HEAVIEST
RAIN WILL FALL MOSTLY NW OF THE LOW CENTER INITIALLY THIS MORNING...
FROM NYC METRO AND POINTS NORTH/WEST...BUT THEN HEAVY RAIN FOCUS
SHOULD SHIFT TO LONG ISLAND AND SOUTHERN CT IN THE AFTERNOON JUST
AHEAD OF THE LOW AS IT MOVES ACROSS. MAIN CONCERN IS FOR MINOR
FLOODING. ISOLD FLASH FLOODING COULD OCCUR WITH HEAVIEST TSTMS FRI
AFTERNOON AND EARLY EVENING ACROSS LONG ISLAND AND SOUTHERN
CT...BUT THIS THREAT APPEARS TOO LOW/ISOLD TO WARRANT A WATCH. A
STORM TOTAL GRAPHIC HAS BEEN POSTED TO THE WEB.
&&
.TIDES/COASTAL FLOODING...
COMBO OF HIGH ASTRONOMICAL HIGH TIDES WITH THE UPCOMING FULL MOON
PLUS ABOUT 1 TO 1.5 FT OF SURGE AHEAD OF THE LOW APPROACHING
THIS MORNING COULD LEAD TO ISOLATED MINOR COASTAL FLOODING AT THE
TIMES OF HIGH TIDE TONIGHT IN THE MOST VULNERABLE LOCATIONS ALONG
THE SOUTH SHORE BACK BAYS OF WRN LONG ISLAND...AND ALONG WRN LONG
ISLAND SOUND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO NOON EDT TODAY
FOR ANZ335-338-345.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EDT THIS
EVENING FOR ANZ330-340.
SMALL CRAFT ADVISORY FROM 4 AM EARLY THIS MORNING TO 6 PM EDT
THIS EVENING FOR ANZ350-353-355.
&&
$$
SYNOPSIS...
NEAR TERM...GOODMAN/JM/PW
SHORT TERM...GOODMAN
LONG TERM...
AVIATION...MET
MARINE...GOODMAN/PW
HYDROLOGY...GOODMAN
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
105 PM EDT FRI SEP 28 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 359 AM EDT FRI SEP 28 2012
A LARGE CANADIAN UPPER LOW WILL DIG INTO THE GREAT LAKES FOR THE
WEEKEND BRINGING SLIGHTLY COOLER TEMPERATURES WITH IT. THIS FEATURE
WILL MOVE OFF TO THE EAST ON MONDAY AND MORE ZONAL FLOW WILL SET UP
ACROSS THE AREA WITH A SLOW WARMING TREND AND DRY WEATHER INTO MID
WEEK.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 1106 AM EDT FRI SEP 28 2012
LOW STRATUS SLOWLY MOVING OUT OF THE FORECAST AREA LATE THIS
MORNING...WITH CLOUD COVER AND FOG LARGELY CONFINED TO THE EASTERN
HALF OF THE FORECAST AREA. STILL A FEW LIGHT SHOWERS OVER FAR
SOUTHERN COUNTIES AS WELL. TEMPS AT 15Z WERE IN THE UPPER 50S AND
LOWER 60S.
MODEL SOUNDINGS AND RH PROGS SHOW LOWER CLOUDS AND FOG WILL
CONTINUE TO MOVE EAST AND MIX OUT INTO A CU FIELD INTO THE
AFTERNOON AS DRIER AIR FILTERS INTO CENTRAL INDIANA. IN LOCATIONS
ACROSS THE WABASH VALLEY WHERE SKIES HAVE CLEARED...SHOULD SEE CU
REDEVELOP AS CONVECTIVE TEMPS ARE MET BY EARLY AFTERNOON. HELD ONTO
A 20 POP OVER EXTREME SOUTHERN PORTIONS OF THE FORECAST AREA TO
ACCOUNT FOR ONGOING LIGHT SHOWERS. HRRR INDICATING THAT THE PRECIP
SHOULD BE OUT OF SOUTHERN COUNTIES BY 18Z WITH DRY WEATHER
THEREAFTER. WITH A SLOWER DEPARTURE TO CLOUDS THIS
MORNING...LOWERED HIGH TEMPS A DEGREE OR TWO IN MOST LOCATIONS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
FORECAST FOCUS IS ON SKY COVER AND TEMPERATURES. MODELS ARE IN
PRETTY GOOD AGREEMENT SO WILL GENERALLY USE A CONSENSUS. FOR TONIGHT
AND SATURDAY EXPECT TO SEE DECREASING CLOUDS ESPECIALLY IN THE WEST
CLOSER TO THE SURFACE HIGH. AN UPPER TROUGH DIGGING INTO THE GREAT
LAKES AND SWINGING A SHORTWAVE THROUGH POSSIBLE NORTHEASTERN INDIANA
OR OHIO COULD KEEP MORE CLOUDS ACROSS NORTHEASTERN PARTS OF THE AREA
SO MAINTAINED HIGHER SKY COVER HERE...BUT LACK OF ANY SIGNIFICANT
MOISTURE AND THE FEATURE ITSELF POTENTIALLY BEING FURTHER EAST
PRECLUDE ANY POP MENTION.
GENERALLY USED A GUIDANCE CONSENSUS FOR OVERNIGHT LOWS AS GUIDANCE
DID A BETTER JOB OF CAPTURING HEAT ISLAND EFFECTS EXPECTING WITH
MOSTLY CLEAR SKIES FOR MOST OF THE AREA DURING THE OVERNIGHT HOURS.
FOR HIGHS USED A CONSENSUS FOR SATURDAY...BUT WENT COOLER THAN
GUIDANCE FOR SUNDAY WITH COLD ADVECTION AT 850 ON THE BACK SIDE OF
THE UPPER LOW.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 316 AM EDT FRI SEP 28 2012
MAIN FOCUS TO THE EXTENDED WILL BE TEMPERATURES AS IT APPEARS DEEPER
MOISTURE WILL BE SOUTH AND EAST OF CENTRAL INDIANA WEDNESDAY NIGHT
AND THURSDAY AHEAD OF FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST.
WOULD ALSO NOT RULE OUT A SHOWER OR TOO MONDAY NIGHT AND TUESDAY AS
A WEAK SYSTEM LIFTS NORTHEAST FROM THE SOUTHERN STATES TO THE
APPALACHIANS...BUT LEFT IT OUT FOR NOW PER THE CENTRAL REGION
INITIALIZATION.
PREFERRED TO STAY CLOSER TO THE 00Z ECMWF WITH THE TIMING OF THE
AFOREMENTIONED FRONT AS THE 00Z GFS LOOKS WAY TOO FAST BASED ON THE
REMAINING LONG RANGE MODELS INCLUDING THE 144 HOUR GEM FRONTAL
POSITION FROM THE 00Z RUN. HOWEVER...WITH MOISTURE LACKING...PULLED
SMALL POPS FROM THE CENTRAL REGION INITIALIZATION AFTER COORDINATION
WITH ILX...PAH...LMK AND ILN. WITH THE FORECAST AREA FOR THE MOST
PART UNDER THE INFLUENCE OF HIGH PRESSURE AND LOW MEAN LEVEL
RH...NOT EXPECTING MUCH CLOUD COVER THROUGH THE PERIOD.
TEMPERATURES LOOK OK FROM THE CR INIT...EXCEPT WILL BUMP THEM UP A
FEW DEGREES ON MONDAY BASED ON LITTLE EXPECTED CLOUD COVER AND 00Z
ECMWF 850 MILLIBAR TEMPERATURES AROUND 10 DEGREE CELSIUS.
TEMPERATURES SHOULD BE SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 70S
BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR THE 28/18Z TAFS/...
ISSUED AT 105 PM EDT FRI SEP 28 2012
BECOMING VFR QUICKLY AT ALL SITES THAT HAVE NOT YET DONE SO...MAINLY
JUST IND. ADDITIONAL RESTRICTIONS POSSIBLE NEAR SUNRISE SATURDAY.
LOW CEILINGS AND FOG HAVE BEEN SLOW TO BURN OFF THIS MORNING AT SOME
SITES...BUT ARE WELL ON THEIR WAY NOW. SCT TO BKN030-040 SHOULD BE
THE RULE FOR MUCH OF THE AFTERNOON...WITH THIS LOWER CLOUD
DISSIPATING AT SUNSET.
SOME LOW LEVEL MOISTURE WILL REMAIN IN PLACE TONIGHT...AND
EXPERIMENTAL SATELLITE GUIDANCE SUGGESTS IFR CONDITIONS POSSIBLE
AGAIN IN THE SOUTH. WILL CARRY MVFR RESTRICTIONS IN FOG WITH A
SCT015 MENTION LATE TONIGHT AT IND/LAF/HUF...AND IFR AT BMG. THIS
SHOULD BURN OFF IN TYPICAL DIURNAL FASHION MID MORNING TOMORROW.
WINDS WILL REMAIN BELOW 10KT THROUGHOUT THE PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....MK
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1106 AM EDT FRI SEP 28 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 359 AM EDT FRI SEP 28 2012
A LARGE CANADIAN UPPER LOW WILL DIG INTO THE GREAT LAKES FOR THE
WEEKEND BRINGING SLIGHTLY COOLER TEMPERATURES WITH IT. THIS FEATURE
WILL MOVE OFF TO THE EAST ON MONDAY AND MORE ZONAL FLOW WILL SET UP
ACROSS THE AREA WITH A SLOW WARMING TREND AND DRY WEATHER INTO MID
WEEK.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 1106 AM EDT FRI SEP 28 2012
LOW STRATUS SLOWLY MOVING OUT OF THE FORECAST AREA LATE THIS
MORNING...WITH CLOUD COVER AND FOG LARGELY CONFINED TO THE EASTERN
HALF OF THE FORECAST AREA. STILL A FEW LIGHT SHOWERS OVER FAR
SOUTHERN COUNTIES AS WELL. TEMPS AT 15Z WERE IN THE UPPER 50S AND
LOWER 60S.
MODEL SOUNDINGS AND RH PROGS SHOW LOWER CLOUDS AND FOG WILL
CONTINUE TO MOVE EAST AND MIX OUT INTO A CU FIELD INTO THE
AFTERNOON AS DRIER AIR FILTERS INTO CENTRAL INDIANA. IN LOCATIONS
ACROSS THE WABASH VALLEY WHERE SKIES HAVE CLEARED...SHOULD SEE CU
REDEVELOP AS CONVECTIVE TEMPS ARE MET BY EARLY AFTERNOON. HELD ONTO
A 20 POP OVER EXTREME SOUTHERN PORTIONS OF THE FORECAST AREA TO
ACCOUNT FOR ONGOING LIGHT SHOWERS. HRRR INDICATING THAT THE PRECIP
SHOULD BE OUT OF SOUTHERN COUNTIES BY 18Z WITH DRY WEATHER
THEREAFTER. WITH A SLOWER DEPARTURE TO CLOUDS THIS
MORNING...LOWERED HIGH TEMPS A DEGREE OR TWO IN MOST LOCATIONS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
FORECAST FOCUS IS ON SKY COVER AND TEMPERATURES. MODELS ARE IN
PRETTY GOOD AGREEMENT SO WILL GENERALLY USE A CONSENSUS. FOR TONIGHT
AND SATURDAY EXPECT TO SEE DECREASING CLOUDS ESPECIALLY IN THE WEST
CLOSER TO THE SURFACE HIGH. AN UPPER TROUGH DIGGING INTO THE GREAT
LAKES AND SWINGING A SHORTWAVE THROUGH POSSIBLE NORTHEASTERN INDIANA
OR OHIO COULD KEEP MORE CLOUDS ACROSS NORTHEASTERN PARTS OF THE AREA
SO MAINTAINED HIGHER SKY COVER HERE...BUT LACK OF ANY SIGNIFICANT
MOISTURE AND THE FEATURE ITSELF POTENTIALLY BEING FURTHER EAST
PRECLUDE ANY POP MENTION.
GENERALLY USED A GUIDANCE CONSENSUS FOR OVERNIGHT LOWS AS GUIDANCE
DID A BETTER JOB OF CAPTURING HEAT ISLAND EFFECTS EXPECTING WITH
MOSTLY CLEAR SKIES FOR MOST OF THE AREA DURING THE OVERNIGHT HOURS.
FOR HIGHS USED A CONSENSUS FOR SATURDAY...BUT WENT COOLER THAN
GUIDANCE FOR SUNDAY WITH COLD ADVECTION AT 850 ON THE BACK SIDE OF
THE UPPER LOW.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 316 AM EDT FRI SEP 28 2012
MAIN FOCUS TO THE EXTENDED WILL BE TEMPERATURES AS IT APPEARS DEEPER
MOISTURE WILL BE SOUTH AND EAST OF CENTRAL INDIANA WEDNESDAY NIGHT
AND THURSDAY AHEAD OF FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST.
WOULD ALSO NOT RULE OUT A SHOWER OR TOO MONDAY NIGHT AND TUESDAY AS
A WEAK SYSTEM LIFTS NORTHEAST FROM THE SOUTHERN STATES TO THE
APPALACHIANS...BUT LEFT IT OUT FOR NOW PER THE CENTRAL REGION
INITIALIZATION.
PREFERRED TO STAY CLOSER TO THE 00Z ECMWF WITH THE TIMING OF THE
AFOREMENTIONED FRONT AS THE 00Z GFS LOOKS WAY TOO FAST BASED ON THE
REMAINING LONG RANGE MODELS INCLUDING THE 144 HOUR GEM FRONTAL
POSITION FROM THE 00Z RUN. HOWEVER...WITH MOISTURE LACKING...PULLED
SMALL POPS FROM THE CENTRAL REGION INITIALIZATION AFTER COORDINATION
WITH ILX...PAH...LMK AND ILN. WITH THE FORECAST AREA FOR THE MOST
PART UNDER THE INFLUENCE OF HIGH PRESSURE AND LOW MEAN LEVEL
RH...NOT EXPECTING MUCH CLOUD COVER THROUGH THE PERIOD.
TEMPERATURES LOOK OK FROM THE CR INIT...EXCEPT WILL BUMP THEM UP A
FEW DEGREES ON MONDAY BASED ON LITTLE EXPECTED CLOUD COVER AND 00Z
ECMWF 850 MILLIBAR TEMPERATURES AROUND 10 DEGREE CELSIUS.
TEMPERATURES SHOULD BE SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 70S
BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR THE 28/15Z TAF UPDATE/...
ISSUED AT 1012 AM EDT FRI SEP 28 2012
CLEARING TO THE WEST IS TRYING TO MAKE ITS WAY INTO IND AND
BMG...AND LIKELY WILL IN THE NEXT FEW HOURS. MINOR ADJUSTMENTS
REQUIRED.
ISSUED AT 618 AM EDT FRI SEP 28 2012
HIGH PRESSURE AND RESIDUAL LOW LEVEL MOISTURE WAS ALLOWING FOG AND
STRATUS TO FORM MAINLY AT IND AND BMG OVERNIGHT. OBSERVATIONAL
TRENDS...MESOSCALE MODELS INCLUDING THE NORTH AMERICAN RAPID REFRESH
ENSEMBLE SYSTEM ALL FAVOR LIFR OR WORSE CONDITIONS AT BMG TO
GRADUALLY IMPROVE TO IFR TOWARD 14Z AND MVFR AND BETTER SHORTLY
THEREAFTER. IND ALSO WAS SEEING LOW CEILINGS AND SHORT START OFF AT
IFR OR WORSE BEFORE BECOMING MVFR BY 14Z AND VFR BY 16Z. CU
DEVELOPMENT PROGS WERE INDICATING AT LEAST BROKEN DIURNAL CU. THE
OTHER SITES WERE DOING BETTER WITH LESS LOW LEVEL MOISTURE SHOWING
UP NICE IN THE MODELS AND THE RAPID REFRESH. COULD ONCE AGAIN SEE
SOME FOG AT BMG TONIGHT...BUT WILL ONLY GO AS LOW AS IFR THERE FOR
NOW AFTER 04Z. OTHERWISE...DRIER AIR SETTLING DOWN FROM THE NORTH
SHOULD KEEP FOG LIGHT IF AT ALL.
WINDS THROUGH THE PERIOD WILL SEE A NORTHERLY COMPONENT AND LESS
THAN 10 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...RYAN
SHORT TERM...CP
LONG TERM....MK
AVIATION...MK/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1012 AM EDT FRI SEP 28 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 359 AM EDT FRI SEP 28 2012
A LARGE CANADIAN UPPER LOW WILL DIG INTO THE GREAT LAKES FOR THE
WEEKEND BRINGING SLIGHTLY COOLER TEMPERATURES WITH IT. THIS FEATURE
WILL MOVE OFF TO THE EAST ON MONDAY AND MORE ZONAL FLOW WILL SET UP
ACROSS THE AREA WITH A SLOW WARMING TREND AND DRY WEATHER INTO MID
WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
MAIN CONCERN IS WHETHER OR NOT TO INCLUDE POPS IN THE SOUTH FOR A
FEW HOURS THIS MORNING. NAM/GFS/ECMWF ARE ALL SHOWING VERY SMALL QPF
ACROSS THE SOUTHERNMOST COUNTIES THIS MORNING...AND HRRR SHOWS
DEVELOPMENT OF SOME ECHOES ACROSS THE SOUTHERN AND CENTRAL COUNTIES.
THIS IS ASSOCIATED WITH A MID LEVEL SHORTWAVE MOVING THROUGH THE
FLOW. TIME HEIGHTS SHOW A LOT OF DRY AIR IN THE MID LEVELS THOUGH
MAKING SATURATION THROUGH THE COLUMN DIFFICULT AND DRY ADVECTION IS
OCCURRING ACROSS AT LEAST THE CENTRAL AND NORTHERN COUNTIES
CURRENTLY. WATER VAPOR LOOP SHOWS THE SHORTWAVE CURRENTLY ACROSS
MISSOURI AND SOME SHOWERS FIRING UP IN FRONT OF IT. ULTIMATELY THINK
THE SHOWERS WILL HAVE TO OVERCOME THE DRY AIR AS THEY HEAD EAST SO
MAY WIND UP JUST BEING SPRINKLES BY THE TIME THEY REACH
INDIANA...BUT COULD ALSO SEE A HUNDREDTH OR TWO EEK OUT IN THE FAR
SOUTHERN COUNTIES. THUS WILL GO WITH AROUND A 30 POP IN THE
SOUTH...TIMED OUT TO MATCH WITH THE CURRENT MOVEMENT OF THE RAIN
SHIELD IN WESTERN ILLINOIS. DON/T SEE INSTABILITY GETTING THIS FAR
NORTH SO WILL NOT INCLUDE THUNDER MENTION. BY AFTERNOON ENTIRE AREA
SHOULD BE DRY. CU RULE SHOWS SCATTERED TO BROKEN CLOUD COVER
DECREASING BY EVENING AND 850 MB TEMPERATURES DECREASING BUT NOT
UNTIL LATER IN THE DAY. THUS THINK HIGHS WILL BE NEAR
YESTERDAY...PERHAPS A DEGREE OR SO COOLER AND THE MAV NUMBERS WENT
WELL WITH THIS THEORY.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
FORECAST FOCUS IS ON SKY COVER AND TEMPERATURES. MODELS ARE IN
PRETTY GOOD AGREEMENT SO WILL GENERALLY USE A CONSENSUS. FOR TONIGHT
AND SATURDAY EXPECT TO SEE DECREASING CLOUDS ESPECIALLY IN THE WEST
CLOSER TO THE SURFACE HIGH. AN UPPER TROUGH DIGGING INTO THE GREAT
LAKES AND SWINGING A SHORTWAVE THROUGH POSSIBLE NORTHEASTERN INDIANA
OR OHIO COULD KEEP MORE CLOUDS ACROSS NORTHEASTERN PARTS OF THE AREA
SO MAINTAINED HIGHER SKY COVER HERE...BUT LACK OF ANY SIGNIFICANT
MOISTURE AND THE FEATURE ITSELF POTENTIALLY BEING FURTHER EAST
PRECLUDE ANY POP MENTION.
GENERALLY USED A GUIDANCE CONSENSUS FOR OVERNIGHT LOWS AS GUIDANCE
DID A BETTER JOB OF CAPTURING HEAT ISLAND EFFECTS EXPECTING WITH
MOSTLY CLEAR SKIES FOR MOST OF THE AREA DURING THE OVERNIGHT HOURS.
FOR HIGHS USED A CONSENSUS FOR SATURDAY...BUT WENT COOLER THAN
GUIDANCE FOR SUNDAY WITH COLD ADVECTION AT 850 ON THE BACK SIDE OF
THE UPPER LOW.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 316 AM EDT FRI SEP 28 2012
MAIN FOCUS TO THE EXTENDED WILL BE TEMPERATURES AS IT APPEARS DEEPER
MOISTURE WILL BE SOUTH AND EAST OF CENTRAL INDIANA WEDNESDAY NIGHT
AND THURSDAY AHEAD OF FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST.
WOULD ALSO NOT RULE OUT A SHOWER OR TOO MONDAY NIGHT AND TUESDAY AS
A WEAK SYSTEM LIFTS NORTHEAST FROM THE SOUTHERN STATES TO THE
APPALACHIANS...BUT LEFT IT OUT FOR NOW PER THE CENTRAL REGION
INITIALIZATION.
PREFERRED TO STAY CLOSER TO THE 00Z ECMWF WITH THE TIMING OF THE
AFOREMENTIONED FRONT AS THE 00Z GFS LOOKS WAY TOO FAST BASED ON THE
REMAINING LONG RANGE MODELS INCLUDING THE 144 HOUR GEM FRONTAL
POSITION FROM THE 00Z RUN. HOWEVER...WITH MOISTURE LACKING...PULLED
SMALL POPS FROM THE CENTRAL REGION INITIALIZATION AFTER COORDINATION
WITH ILX...PAH...LMK AND ILN. WITH THE FORECAST AREA FOR THE MOST
PART UNDER THE INFLUENCE OF HIGH PRESSURE AND LOW MEAN LEVEL
RH...NOT EXPECTING MUCH CLOUD COVER THROUGH THE PERIOD.
TEMPERATURES LOOK OK FROM THE CR INIT...EXCEPT WILL BUMP THEM UP A
FEW DEGREES ON MONDAY BASED ON LITTLE EXPECTED CLOUD COVER AND 00Z
ECMWF 850 MILLIBAR TEMPERATURES AROUND 10 DEGREE CELSIUS.
TEMPERATURES SHOULD BE SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 70S
BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR THE 28/15Z TAF UPDATE/...
ISSUED AT 1012 AM EDT FRI SEP 28 2012
CLEARING TO THE WEST IS TRYING TO MAKE ITS WAY INTO IND AND
BMG...AND LIKELY WILL IN THE NEXT FEW HOURS. MINOR ADJUSTMENTS
REQUIRED.
ISSUED AT 618 AM EDT FRI SEP 28 2012
HIGH PRESSURE AND RESIDUAL LOW LEVEL MOISTURE WAS ALLOWING FOG AND
STRATUS TO FORM MAINLY AT IND AND BMG OVERNIGHT. OBSERVATIONAL
TRENDS...MESOSCALE MODELS INCLUDING THE NORTH AMERICAN RAPID REFRESH
ENSEMBLE SYSTEM ALL FAVOR LIFR OR WORSE CONDITIONS AT BMG TO
GRADUALLY IMPROVE TO IFR TOWARD 14Z AND MVFR AND BETTER SHORTLY
THEREAFTER. IND ALSO WAS SEEING LOW CEILINGS AND SHORT START OFF AT
IFR OR WORSE BEFORE BECOMING MVFR BY 14Z AND VFR BY 16Z. CU
DEVELOPMENT PROGS WERE INDICATING AT LEAST BROKEN DIURNAL CU. THE
OTHER SITES WERE DOING BETTER WITH LESS LOW LEVEL MOISTURE SHOWING
UP NICE IN THE MODELS AND THE RAPID REFRESH. COULD ONCE AGAIN SEE
SOME FOG AT BMG TONIGHT...BUT WILL ONLY GO AS LOW AS IFR THERE FOR
NOW AFTER 04Z. OTHERWISE...DRIER AIR SETTLING DOWN FROM THE NORTH
SHOULD KEEP FOG LIGHT IF AT ALL.
WINDS THROUGH THE PERIOD WILL SEE A NORTHERLY COMPONENT AND LESS
THAN 10 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...MK/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
618 AM EDT FRI SEP 28 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 359 AM EDT FRI SEP 28 2012
A LARGE CANADIAN UPPER LOW WILL DIG INTO THE GREAT LAKES FOR THE
WEEKEND BRINGING SLIGHTLY COOLER TEMPERATURES WITH IT. THIS FEATURE
WILL MOVE OFF TO THE EAST ON MONDAY AND MORE ZONAL FLOW WILL SET UP
ACROSS THE AREA WITH A SLOW WARMING TREND AND DRY WEATHER INTO MID
WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
MAIN CONCERN IS WHETHER OR NOT TO INCLUDE POPS IN THE SOUTH FOR A
FEW HOURS THIS MORNING. NAM/GFS/ECMWF ARE ALL SHOWING VERY SMALL QPF
ACROSS THE SOUTHERNMOST COUNTIES THIS MORNING...AND HRRR SHOWS
DEVELOPMENT OF SOME ECHOES ACROSS THE SOUTHERN AND CENTRAL COUNTIES.
THIS IS ASSOCIATED WITH A MID LEVEL SHORTWAVE MOVING THROUGH THE
FLOW. TIME HEIGHTS SHOW A LOT OF DRY AIR IN THE MID LEVELS THOUGH
MAKING SATURATION THROUGH THE COLUMN DIFFICULT AND DRY ADVECTION IS
OCCURRING ACROSS AT LEAST THE CENTRAL AND NORTHERN COUNTIES
CURRENTLY. WATER VAPOR LOOP SHOWS THE SHORTWAVE CURRENTLY ACROSS
MISSOURI AND SOME SHOWERS FIRING UP IN FRONT OF IT. ULTIMATELY THINK
THE SHOWERS WILL HAVE TO OVERCOME THE DRY AIR AS THEY HEAD EAST SO
MAY WIND UP JUST BEING SPRINKLES BY THE TIME THEY REACH
INDIANA...BUT COULD ALSO SEE A HUNDREDTH OR TWO EEK OUT IN THE FAR
SOUTHERN COUNTIES. THUS WILL GO WITH AROUND A 30 POP IN THE
SOUTH...TIMED OUT TO MATCH WITH THE CURRENT MOVEMENT OF THE RAIN
SHIELD IN WESTERN ILLINOIS. DON/T SEE INSTABILITY GETTING THIS FAR
NORTH SO WILL NOT INCLUDE THUNDER MENTION. BY AFTERNOON ENTIRE AREA
SHOULD BE DRY. CU RULE SHOWS SCATTERED TO BROKEN CLOUD COVER
DECREASING BY EVENING AND 850 MB TEMPERATURES DECREASING BUT NOT
UNTIL LATER IN THE DAY. THUS THINK HIGHS WILL BE NEAR
YESTERDAY...PERHAPS A DEGREE OR SO COOLER AND THE MAV NUMBERS WENT
WELL WITH THIS THEORY.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
FORECAST FOCUS IS ON SKY COVER AND TEMPERATURES. MODELS ARE IN
PRETTY GOOD AGREEMENT SO WILL GENERALLY USE A CONSENSUS. FOR TONIGHT
AND SATURDAY EXPECT TO SEE DECREASING CLOUDS ESPECIALLY IN THE WEST
CLOSER TO THE SURFACE HIGH. AN UPPER TROUGH DIGGING INTO THE GREAT
LAKES AND SWINGING A SHORTWAVE THROUGH POSSIBLE NORTHEASTERN INDIANA
OR OHIO COULD KEEP MORE CLOUDS ACROSS NORTHEASTERN PARTS OF THE AREA
SO MAINTAINED HIGHER SKY COVER HERE...BUT LACK OF ANY SIGNIFICANT
MOISTURE AND THE FEATURE ITSELF POTENTIALLY BEING FURTHER EAST
PRECLUDE ANY POP MENTION.
GENERALLY USED A GUIDANCE CONSENSUS FOR OVERNIGHT LOWS AS GUIDANCE
DID A BETTER JOB OF CAPTURING HEAT ISLAND EFFECTS EXPECTING WITH
MOSTLY CLEAR SKIES FOR MOST OF THE AREA DURING THE OVERNIGHT HOURS.
FOR HIGHS USED A CONSENSUS FOR SATURDAY...BUT WENT COOLER THAN
GUIDANCE FOR SUNDAY WITH COLD ADVECTION AT 850 ON THE BACK SIDE OF
THE UPPER LOW.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 316 AM EDT FRI SEP 28 2012
MAIN FOCUS TO THE EXTENDED WILL BE TEMPERATURES AS IT APPEARS DEEPER
MOISTURE WILL BE SOUTH AND EAST OF CENTRAL INDIANA WEDNESDAY NIGHT
AND THURSDAY AHEAD OF FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST.
WOULD ALSO NOT RULE OUT A SHOWER OR TOO MONDAY NIGHT AND TUESDAY AS
A WEAK SYSTEM LIFTS NORTHEAST FROM THE SOUTHERN STATES TO THE
APPALACHIANS...BUT LEFT IT OUT FOR NOW PER THE CENTRAL REGION
INITIALIZATION.
PREFERRED TO STAY CLOSER TO THE 00Z ECMWF WITH THE TIMING OF THE
AFOREMENTIONED FRONT AS THE 00Z GFS LOOKS WAY TOO FAST BASED ON THE
REMAINING LONG RANGE MODELS INCLUDING THE 144 HOUR GEM FRONTAL
POSITION FROM THE 00Z RUN. HOWEVER...WITH MOISTURE LACKING...PULLED
SMALL POPS FROM THE CENTRAL REGION INITIALIZATION AFTER COORDINATION
WITH ILX...PAH...LMK AND ILN. WITH THE FORECAST AREA FOR THE MOST
PART UNDER THE INFLUENCE OF HIGH PRESSURE AND LOW MEAN LEVEL
RH...NOT EXPECTING MUCH CLOUD COVER THROUGH THE PERIOD.
TEMPERATURES LOOK OK FROM THE CR INIT...EXCEPT WILL BUMP THEM UP A
FEW DEGREES ON MONDAY BASED ON LITTLE EXPECTED CLOUD COVER AND 00Z
ECMWF 850 MILLIBAR TEMPERATURES AROUND 10 DEGREE CELSIUS.
TEMPERATURES SHOULD BE SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 70S
BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR THE 281200Z TAF ISSUANCE/...
ISSUED AT 618 AM EDT FRI SEP 28 2012
HIGH PRESSURE AND RESIDUAL LOW LEVEL MOISTURE WAS ALLOWING FOG AND
STRATUS TO FORM MAINLY AT IND AND BMG OVERNIGHT. OBSERVATIONAL
TRENDS...MESOSCALE MODELS INCLUDING THE NORTH AMERICAN RAPID REFRESH
ENSEMBLE SYSTEM ALL FAVOR LIFR OR WORSE CONDITIONS AT BMG TO
GRADUALLY IMPROVE TO IFR TOWARD 14Z AND MVFR AND BETTER SHORTLY
THEREAFTER. IND ALSO WAS SEEING LOW CEILINGS AND SHORT START OFF AT
IFR OR WORSE BEFORE BECOMING MVFR BY 14Z AND VFR BY 16Z. CU
DEVELOPMENT PROGS WERE INDICATING AT LEAST BROKEN DIURNAL CU. THE
OTHER SITES WERE DOING BETTER WITH LESS LOW LEVEL MOISTURE SHOWING
UP NICE IN THE MODELS AND THE RAPID REFRESH. COULD ONCE AGAIN SEE
SOME FOG AT BMG TONIGHT...BUT WILL ONLY GO AS LOW AS IFR THERE FOR
NOW AFTER 04Z. OTHERWISE...DRIER AIR SETTLING DOWN FROM THE NORTH
SHOULD KEEP FOG LIGHT IF AT ALL.
WINDS THROUGH THE PERIOD WILL SEE A NORTHERLY COMPONENT AND LESS
THAN 10 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
426 AM EDT FRI SEP 28 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 359 AM EDT FRI SEP 28 2012
A LARGE CANADIAN UPPER LOW WILL DIG INTO THE GREAT LAKES FOR THE
WEEKEND BRINGING SLIGHTLY COOLER TEMPERATURES WITH IT. THIS FEATURE
WILL MOVE OFF TO THE EAST ON MONDAY AND MORE ZONAL FLOW WILL SET UP
ACROSS THE AREA WITH A SLOW WARMING TREND AND DRY WEATHER INTO MID
WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
MAIN CONCERN IS WHETHER OR NOT TO INCLUDE POPS IN THE SOUTH FOR A
FEW HOURS THIS MORNING. NAM/GFS/ECMWF ARE ALL SHOWING VERY SMALL QPF
ACROSS THE SOUTHERNMOST COUNTIES THIS MORNING...AND HRRR SHOWS
DEVELOPMENT OF SOME ECHOES ACROSS THE SOUTHERN AND CENTRAL COUNTIES.
THIS IS ASSOCIATED WITH A MID LEVEL SHORTWAVE MOVING THROUGH THE
FLOW. TIME HEIGHTS SHOW A LOT OF DRY AIR IN THE MID LEVELS THOUGH
MAKING SATURATION THROUGH THE COLUMN DIFFICULT AND DRY ADVECTION IS
OCCURRING ACROSS AT LEAST THE CENTRAL AND NORTHERN COUNTIES
CURRENTLY. WATER VAPOR LOOP SHOWS THE SHORTWAVE CURRENTLY ACROSS
MISSOURI AND SOME SHOWERS FIRING UP IN FRONT OF IT. ULTIMATELY THINK
THE SHOWERS WILL HAVE TO OVERCOME THE DRY AIR AS THEY HEAD EAST SO
MAY WIND UP JUST BEING SPRINKLES BY THE TIME THEY REACH
INDIANA...BUT COULD ALSO SEE A HUNDREDTH OR TWO EEK OUT IN THE FAR
SOUTHERN COUNTIES. THUS WILL GO WITH AROUND A 30 POP IN THE
SOUTH...TIMED OUT TO MATCH WITH THE CURRENT MOVEMENT OF THE RAIN
SHIELD IN WESTERN ILLINOIS. DON/T SEE INSTABILITY GETTING THIS FAR
NORTH SO WILL NOT INCLUDE THUNDER MENTION. BY AFTERNOON ENTIRE AREA
SHOULD BE DRY. CU RULE SHOWS SCATTERED TO BROKEN CLOUD COVER
DECREASING BY EVENING AND 850 MB TEMPERATURES DECREASING BUT NOT
UNTIL LATER IN THE DAY. THUS THINK HIGHS WILL BE NEAR
YESTERDAY...PERHAPS A DEGREE OR SO COOLER AND THE MAV NUMBERS WENT
WELL WITH THIS THEORY.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
FORECAST FOCUS IS ON SKY COVER AND TEMPERATURES. MODELS ARE IN
PRETTY GOOD AGREEMENT SO WILL GENERALLY USE A CONSENSUS. FOR TONIGHT
AND SATURDAY EXPECT TO SEE DECREASING CLOUDS ESPECIALLY IN THE WEST
CLOSER TO THE SURFACE HIGH. AN UPPER TROUGH DIGGING INTO THE GREAT
LAKES AND SWINGING A SHORTWAVE THROUGH POSSIBLE NORTHEASTERN INDIANA
OR OHIO COULD KEEP MORE CLOUDS ACROSS NORTHEASTERN PARTS OF THE AREA
SO MAINTAINED HIGHER SKY COVER HERE...BUT LACK OF ANY SIGNIFICANT
MOISTURE AND THE FEATURE ITSELF POTENTIALLY BEING FURTHER EAST
PRECLUDE ANY POP MENTION.
GENERALLY USED A GUIDANCE CONSENSUS FOR OVERNIGHT LOWS AS GUIDANCE
DID A BETTER JOB OF CAPTURING HEAT ISLAND EFFECTS EXPECTING WITH
MOSTLY CLEAR SKIES FOR MOST OF THE AREA DURING THE OVERNIGHT HOURS.
FOR HIGHS USED A CONSENSUS FOR SATURDAY...BUT WENT COOLER THAN
GUIDANCE FOR SUNDAY WITH COLD ADVECTION AT 850 ON THE BACK SIDE OF
THE UPPER LOW.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 316 AM EDT FRI SEP 28 2012
MAIN FOCUS TO THE EXTENDED WILL BE TEMPERATURES AS IT APPEARS DEEPER
MOISTURE WILL BE SOUTH AND EAST OF CENTRAL INDIANA WEDNESDAY NIGHT
AND THURSDAY AHEAD OF FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST.
WOULD ALSO NOT RULE OUT A SHOWER OR TOO MONDAY NIGHT AND TUESDAY AS
A WEAK SYSTEM LIFTS NORTHEAST FROM THE SOUTHERN STATES TO THE
APPALACHIANS...BUT LEFT IT OUT FOR NOW PER THE CENTRAL REGION
INITIALIZATION.
PREFERRED TO STAY CLOSER TO THE 00Z ECMWF WITH THE TIMING OF THE
AFOREMENTIONED FRONT AS THE 00Z GFS LOOKS WAY TOO FAST BASED ON THE
REMAINING LONG RANGE MODELS INCLUDING THE 144 HOUR GEM FRONTAL
POSITION FROM THE 00Z RUN. HOWEVER...WITH MOISTURE LACKING...PULLED
SMALL POPS FROM THE CENTRAL REGION INITIALIZATION AFTER COORDINATION
WITH ILX...PAH...LMK AND ILN. WITH THE FORECAST AREA FOR THE MOST
PART UNDER THE INFLUENCE OF HIGH PRESSURE AND LOW MEAN LEVEL
RH...NOT EXPECTING MUCH CLOUD COVER THROUGH THE PERIOD.
TEMPERATURES LOOK OK FROM THE CR INIT...EXCEPT WILL BUMP THEM UP A
FEW DEGREES ON MONDAY BASED ON LITTLE EXPECTED CLOUD COVER AND 00Z
ECMWF 850 MILLIBAR TEMPERATURES AROUND 10 DEGREE CELSIUS.
TEMPERATURES SHOULD BE SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 70S
BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR THE 280900Z TAF UPDATES/...
ISSUED AT 426 AM EDT FRI SEP 28 2012
BMG CEILING AND VISIBILITY HAS DROPPED TO LIFR AND SHOULD REMAIN
THERE OR WORSE OVERNIGHT. OTHERWISE...HUF WAS VFR WITH A 4K DECK AND
STILL 8 DEGREE TEMPERATURE/DEW POINT SPREAD...SO PULLED FOG AND LOW
CEILINGS THERE. OTHERWISE...LITTLE CHANGES TO THE TAFS.
PREVIOUS DISCUSSION FOLLOWS...
A PERIOD OF IFR CEILINGS FOG STILL LIKELY AT KIND...KHUF...KBMG...
WHILE MVFR CEILINGS FOG STILL POSSIBLE AT KLAF. THIS WILL OCCUR
LATE TONIGHT AND EARLY FRIDAY MAINLY FROM 09Z-14Z. SATELLITE AND
WEATHER DEPICTION IS SHOWING AN AREA OF IFR CEILINGS ADVANCING
ACROSS EAST CENTRAL INDIANA AND DEWPOINTS STILL AROUND 60 AT
KIND...KHUF AND KBMG. WITH LIGHT WINDS AND MOIST GROUND AND SOME
RADIATIONAL COOLING EXPECT IFR CONDITIONS TO GRADUALLY INCREASE LATE
TONIGHT. DRIER AIR HAS SPREAD INTO KLAF...BUT WEATHER DEPICTION
SHOWS SOME AREAS OF MVFR CEILINGS TO THE NORTHEAST OF KLAF.
ON FRIDAY...STRATUS/FOG WILL LIFT BY MID TO LATE MORNING. CONVECTIVE
TEMPERATURES WILL BE IN UPPER 60S...SO EXPECT MOSTLY BROKEN 4 TO 5
THOUSAND CLOUDS MIDDAY ON WITH CLEARING LATE FRIDAY AND EARLY FRIDAY
EVENING.
HIGH PRESSURE OVER THE GREAT LAKES WILL KEEP US UNDER A VERY LIGHT
NORTH TO NORTHEAST FLOW FRIDAY AND FRIDAY EVENING. WINDS WILL BE
ALMOST NEAR CALM OVERNIGHT AND 7 KNOTS OR LESS FRIDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...JH/MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
404 AM EDT FRI SEP 28 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 359 AM EDT FRI SEP 28 2012
A LARGE CANADIAN UPPER LOW WILL DIG INTO THE GREAT LAKES FOR THE
WEEKEND BRINGING SLIGHTLY COOLER TEMPERATURES WITH IT. THIS FEATURE
WILL MOVE OFF TO THE EAST ON MONDAY AND MORE ZONAL FLOW WILL SET UP
ACROSS THE AREA WITH A SLOW WARMING TREND AND DRY WEATHER INTO MID
WEEK.
&&
.NEAR TERM /TODAY/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
MAIN CONCERN IS WHETHER OR NOT TO INCLUDE POPS IN THE SOUTH FOR A
FEW HOURS THIS MORNING. NAM/GFS/ECMWF ARE ALL SHOWING VERY SMALL QPF
ACROSS THE SOUTHERNMOST COUNTIES THIS MORNING...AND HRRR SHOWS
DEVELOPMENT OF SOME ECHOES ACROSS THE SOUTHERN AND CENTRAL COUNTIES.
THIS IS ASSOCIATED WITH A MID LEVEL SHORTWAVE MOVING THROUGH THE
FLOW. TIME HEIGHTS SHOW A LOT OF DRY AIR IN THE MID LEVELS THOUGH
MAKING SATURATION THROUGH THE COLUMN DIFFICULT AND DRY ADVECTION IS
OCCURRING ACROSS AT LEAST THE CENTRAL AND NORTHERN COUNTIES
CURRENTLY. WATER VAPOR LOOP SHOWS THE SHORTWAVE CURRENTLY ACROSS
MISSOURI AND SOME SHOWERS FIRING UP IN FRONT OF IT. ULTIMATELY THINK
THE SHOWERS WILL HAVE TO OVERCOME THE DRY AIR AS THEY HEAD EAST SO
MAY WIND UP JUST BEING SPRINKLES BY THE TIME THEY REACH INDIANA...BUT
COULD ALSO SEE A HUNDREDTH OR TWO EEK OUT IN THE FAR SOUTHERN
COUNTIES. THUS WILL GO WITH AROUND A 30 POP IN THE SOUTH...TIMED OUT
TO MATCH WITH THE CURRENT MOVEMENT OF THE RAIN SHIELD IN WESTERN
ILLINOIS. DON/T SEE INSTABILITY GETTING THIS FAR NORTH SO WILL NOT
INCLUDE THUNDER MENTION. BY AFTERNOON ENTIRE AREA SHOULD BE DRY. CU
RULE SHOWS SCATTERED TO BROKEN CLOUD COVER DECREASING BY EVENING AND
850 MB TEMPERATURES DECREASING BUT NOT UNTIL LATER IN THE DAY. THUS
THINK HIGHS WILL BE NEAR YESTERDAY...PERHAPS A DEGREE OR SO COOLER
AND THE MAV NUMBERS WENT WELL WITH THIS THEORY.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 359 AM EDT FRI SEP 28 2012
FORECAST FOCUS IS ON SKY COVER AND TEMPERATURES. MODELS ARE IN PRETTY GOOD
AGREEMENT SO WILL GENERALLY USE A CONSENSUS. FOR TONIGHT AND
SATURDAY EXPECT TO SEE DECREASING CLOUDS ESPECIALLY IN THE WEST
CLOSER TO THE SURFACE HIGH. AN UPPER TROUGH DIGGING INTO THE GREAT
LAKES AND SWINGING A SHORTWAVE THROUGH POSSIBLE NORTHEASTERN INDIANA
OR OHIO COULD KEEP MORE CLOUDS ACROSS NORTHEASTERN PARTS OF THE AREA
SO MAINTAINED HIGHER SKY COVER HERE...BUT LACK OF ANY SIGNIFICANT
MOISTURE AND THE FEATURE ITSELF POTENTIALLY BEING FURTHER EAST
PRECLUDE ANY POP MENTION.
GENERALLY USED A GUIDANCE CONSENSUS FOR OVERNIGHT LOWS AS GUIDANCE
DID A BETTER JOB OF CAPTURING HEAT ISLAND EFFECTS EXPECTING WITH
MOSTLY CLEAR SKIES FOR MOST OF THE AREA DURING THE OVERNIGHT HOURS.
FOR HIGHS USED A CONSENSUS FOR SATURDAY...BUT WENT COOLER THAN
GUIDANCE FOR SUNDAY WITH COLD ADVECTION AT 850 ON THE BACK SIDE OF
THE UPPER LOW.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 316 AM EDT FRI SEP 28 2012
MAIN FOCUS TO THE EXTENDED WILL BE TEMPERATURES AS IT APPEARS DEEPER
MOISTURE WILL BE SOUTH AND EAST OF CENTRAL INDIANA WEDNESDAY NIGHT
AND THURSDAY AHEAD OF FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST.
WOULD ALSO NOT RULE OUT A SHOWER OR TOO MONDAY NIGHT AND TUESDAY AS
A WEAK SYSTEM LIFTS NORTHEAST FROM THE SOUTHERN STATES TO THE
APPALACHIANS...BUT LEFT IT OUT FOR NOW PER THE CENTRAL REGION
INITIALIZATION.
PREFERRED TO STAY CLOSER TO THE 00Z ECMWF WITH THE TIMING OF THE
AFOREMENTIONED FRONT AS THE 00Z GFS LOOKS WAY TOO FAST BASED ON THE
REMAINING LONG RANGE MODELS INCLUDING THE 144 HOUR GEM FRONTAL
POSITION FROM THE 00Z RUN. HOWEVER...WITH MOISTURE LACKING...PULLED
SMALL POPS FROM THE CENTRAL REGION INITIALIZATION AFTER COORDINATION
WITH ILX...PAH...LMK AND ILN. WITH THE FORECAST AREA FOR THE MOST
PART UNDER THE INFLUENCE OF HIGH PRESSURE AND LOW MEAN LEVEL
RH...NOT EXPECTING MUCH CLOUD COVER THROUGH THE PERIOD.
TEMPERATURES LOOK OK FROM THE CR INIT...EXCEPT WILL BUMP THEM UP A
FEW DEGREES ON MONDAY BASED ON LITTLE EXPECTED CLOUD COVER AND 00Z
ECMWF 850 MILLIBAR TEMPERATURES AROUND 10 DEGREE CELSIUS.
TEMPERATURES SHOULD BE SLIGHTLY ABOVE NORMAL IN THE MID TO UPPER 70S
BY TUESDAY.
&&
.AVIATION /DISCUSSION FOR THE 280600Z TAF ISSUANCE/...
ISSUED AT 1200 AM EDT FRI SEP 28 2012
A PERIOD OF IFR CEILINGS FOG STILL LIKELY AT KIND...KHUF...KBMG...
WHILE MVFR CEILINGS FOG STILL POSSIBLE AT KLAF. THIS WILL OCCUR
LATE TONIGHT AND EARLY FRIDAY MAINLY FROM 09Z-14Z. SATELLITE AND
WEATHER DEPICTION IS SHOWING AN AREA OF IFR CEILINGS ADVANCING
ACROSS EAST CENTRAL INDIANA AND DEWPOINTS STILL AROUND 60 AT
KIND...KHUF AND KBMG. WITH LIGHT WINDS AND MOIST GROUND AND SOME
RADIATIONAL COOLING EXPECT IFR CONDITIONS TO GRADUALLY INCREASE LATE
TONIGHT. DRIER AIR HAS SPREAD INTO KLAF...BUT WEATHER DEPICTION
SHOWS SOME AREAS OF MVFR CEILINGS TO THE NORTHEAST OF KLAF.
ON FRIDAY...STRATUS/FOG WILL LIFT BY MID TO LATE MORNING. CONVECTIVE
TEMPERATURES WILL BE IN UPPER 60S...SO EXPECT MOSTLY BROKEN 4 TO 5
THOUSAND CLOUDS MIDDAY ON WITH CLEARING LATE FRIDAY AND EARLY FRIDAY
EVENING.
HIGH PRESSURE OVER THE GREAT LAKES WILL KEEP US UNDER A VERY LIGHT
NORTH TO NORTHEAST FLOW FRIDAY AND FRIDAY EVENING. WINDS WILL BE
ALMOST NEAR CALM OVERNIGHT AND 7 KNOTS OR LESS FRIDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...JH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
803 PM MDT SAT SEP 29 2012
.UPDATE...
ISSUED AT 745 PM MDT SAT SEP 29 2012
JUST COMPLETED AN UPDATE THROUGH TOMORROW. LATEST MODELS CONFIRMED
BY SURFACE ANALYSIS. SURFACE TROUGH STILL CLOSE TO THE FRONT AND
MODELS HAVE THIS TOO FAR EAST. THE RUC FOLLOWED BY THE HRRR AND
NAM WERE THE BEST MODELS WITH THIS. AS A RESULT WINDS WILL STAY
FROM A SOUTH TO SOUTHEAST DIRECTION WELL INTO THE NIGHT ALLOWED AN
INCREASE IN BLYR MOISTURE. BECAUSE OF ALL THIS INCREASED CLOUD
COVER THROUGH THE NIGHT TO ACCOUNT FOR STRATUS AND ALSO INSERTED
AREAS OF FOG OVER MOST OF THE AREA BEGINNING AT 06Z. ALSO ADJUSTED
THE WINDS AND DEWPOINTS ACCORDING THE RUC...NAM...AND HRRR.
CURRENTLY LITTLE IF ANY PRECIPITATION OCCURRING CLOSE TO THE
FORECAST AREA. 00Z SOUNDINGS AND SATELLITE SHOW DEEP DRY LAYER AND
LITTLE IF ANY LIFT ACROSS THE AREA AT THIS TIME. LIFT FROM INCOMING
SURFACE TROUGH AND SHORTWAVE TROUGH AND DEEPER MOISTURE INCREASES
AFTER 06Z...ESPECIALLY BY LATER IN THE NIGHT. ALSO ELEVATED CAPE
INCREASES DRAMATICALLY WITH CINH THAT CAN BE OVERCOME. SO CONFINED
A SLIGHT CHANCE OF THUNDERSTORMS UNTIL AFTER 06Z AND TO THE WEST
OF THE COLORADO BORDER. THEN INCREASED THUNDERSTORM CHANCES AFTER
12Z AND GRADUALLY PROGRESS THIS ACROSS THE FORECAST AREA THROUGH
THE DAY.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 142 PM MDT SAT SEP 29 2012
NORTHWEST FLOW WILL BRING A SHORTWAVE INTO THE REGION LATE TONIGHT
AND SUNDAY. A SURFACE TROUGH IN EASTERN COLORADO TONIGHT WILL SHIFT
EAST ACROSS NORTHWEST KANSAS SUNDAY.
SHORTWAVE TIMING WILL KEEP POPS NIL ACROSS MOST OF THE FA WITH
EXCEPTION OF EASTERN COLORADO THIS EVENING. EASTERN COLORADO WILL BE
THE FIRST ZONES TO HAVE ANY CHANCE THIS EVENING. WEAK DYNAMICS WILL
THEN SPREAD INTO NORTHWEST KANSAS/EXTREME SOUTHWEST NEBRASKA AFTER
06Z SUNDAY. AFTER A MORNING LULL, THERE WILL BE A CHANCE OF
THUNDERSTORMS ACROSS NORTHWEST KANSAS SUNDAY AFTERNOON GENERALLY
EAST OF GOODLAND.
BOUNDARY LAYER RH GETS HIGH ENOUGH TO SUPPORT PATCHY FOG OVER THE
SOUTHEAST ZONES LATE TONIGHT. TEMPERATURES TONIGHT WILL FALL TO THE
LOWER 50S. HIGHS SUNDAY WILL BE IN THE UPPER 70S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 220 PM MDT SAT SEP 29 2012
THE 12Z GFS AND ECMWF HAVE SLOWED THE PRE-FRONTAL SURFACE TROUGH DOWN
FOR SUNDAY TO WHAT THE NAM HAS BEEN SHOWING THE LAST COUPLE OF
DAYS. WITH THE LATEST GEFS MEMBERS ALSO SLOWING THE TROUGH DOWN
WILL KEEP HIGHER PRECIP. CHANCES OVER THE EASTERN 1/3 OF THE AREA SUNDAY EVENING.
EXTENDED THE SLIGHT CHANCES OVER THE EAST PAST MIDNIGHT DUE TO THE
SLOWER TROUGH PASSAGE. MEANWHILE A COOLER AIR MASS WILL BEGIN TO MOVE INTO
THE AREA DURING THE OVERNIGHT HOURS.
MONDAY DRIER AIR MOVES INTO THE AREA SO WILL CONTINUE TO LEAVE THE
FORECAST DRY DESPITE AN UPPER LEVEL SHORT WAVE TROUGH MOVING THROUGH
DURING THE AFTERNOON. SURFACE WINDS WILL STRENGTHEN DURING THE
AFTERNOON AS WINDS OF 20 TO 30 KTS MIX DOWN FROM 700MB.
MONDAY NIGHT WILL ALSO BE DRY AS A SURFACE AND UPPER LEVEL RIDGE
MOVE THROUGH AND POINT SOUNDINGS CONTINUE TO DRY OUT.
FOR THE TUESDAY THROUGH SATURDAY PERIOD MODELS ARE COMING INTO
BETTER AGREEMENT REGARDING THE TIMING OF THE UPPER LEVEL TROUGH
DROPPING DOWN FROM CANADA INTO THE CENTRAL PLAINS. CURRENT MODEL
RUNS HAVE THE TROUGH PASSING THROUGH THE AREA WEDNESDAY NIGHT...WITH
THE MAJORITY OF THE LIFT WITH THE TROUGH NORTH OF THE AREA. WITH
1000-500MB RELATIVE HUMIDITY INCREASING AS THE TROUGH MOVES
THROUGH...HAVE INTRODUCED PRECIP. CHANCES ALONG/NORTH OF THE
NEBRASKA LINE. THE TROUGH BROADENS DURING THE LATTER HALF OF THE
WORK WEEK AS ANOTHER SHORT WAVE TROUGH DIVES SOUTH ACROSS THE
PLAINS...PASSING OVER THE AREA SATURDAY. MODELS CURRENTLY PLACE THE
MAJORITY OF THE 1000-500MB RELATIVE HUMIDITY JUST NORTH OF THE AREA...SO
WILL KEEP PRECIP. CHANCES IN THE SILENT CATEGORY FOR NOW.
A STRONG COLD FRONT WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT.
BELOW NORMAL TEMPERATURES CAN BE EXPECTED AFTER WEDNESDAY AS THE COOLER AIR
MASS REMAINS OVER THE AREA. SOME LOCATIONS...ESPECIALLY THOSE IN
LOW LYING AREAS MAY SEE FROST FRIDAY AND SATURDAY MORNING AS LOW
TEMPERATURES APPROACH THE MID 30S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 553 PM MDT SAT SEP 29 2012
COMPLICATED SET OF TAFS. MODELS ARE SLOWER IN BRINGING SURFACE
TROUGH THROUGH THE AREA TONIGHT. AS A RESULT THE WINDS WILL
REMAIN FROM A SOUTH TO SOUTHEAST DIRECTION MOST OF THE NIGHT WHICH
SHOULD KEEP THE LOW LEVEL AIR MASS MOIST. BELIEVE MODELS ARE UNDERDOING
MOISTURE RETURN AS A RESULT. LATEST RUC AND NAM STILL HAVE THE
WIND SHIFT TO THE WEST OF KGLD AT 12Z. THOSE MODELS PLUS THE HRRR HAVE
STRATUS AND FOG FURTHER WEST THAN CURRENTLY DEPICTED. STRATUS AND
FOG WILL DEVELOP AFTER 06Z. SO PUT IN MVFR CEILINGS AND VISIBILITIES
UNTIL NEAR 15Z.
AT THAT TIME...SURFACE TROUGH AND MID LEVEL SHORTWAVE TROUGH WILL
BEGIN TO AFFECT THE AREA. MODELS SHOW A RATHER HIGH AMOUNT OF
ELEVATED CAPE AND NOT A LOT OF CINH. DEEP LIFT AND MOISTURE LOOK
TO CREATE A LINE OF THUNDERSTORMS DURING THE TIME. THE LINE LOOKS
TO FORM NEAR KGLD AND IS POSSIBLE THAT IT COULD FORM JUST EAST OF
KGLD. MORE SURE THAT KMCK WILL BE AFFECTED BY THUNDERSTORMS BY
MIDDAY. SINCE IT WILL BE CLOSE AT KGLD AND THUNDERSTORMS NOT
EXPECTED AT KMCK UNTIL THE LAST 6 HOURS OF THE PERIOD...CHOSE TO
ONLY HAVE VCTS AT THIS TIME. WILL ADJUST WITH THE NEWER DATA BUT
WOULD EXPECT THAT KMCK WILL HAVE A GOOD CHANCE TO BE AFFECTED BY
THUNDERSTORMS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...FS
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
602 PM MDT SAT SEP 29 2012
.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 142 PM MDT SAT SEP 29 2012
NORTHWEST FLOW WILL BRING A SHORTWAVE INTO THE REGION LATE TONIGHT
AND SUNDAY. A SURFACE TROUGH IN EASTERN COLORADO TONIGHT WILL SHIFT
EAST ACROSS NORTHWEST KANSAS SUNDAY.
SHORTWAVE TIMING WILL KEEP POPS NIL ACROSS MOST OF THE FA WITH
EXCEPTION OF EASTERN COLORADO THIS EVENING. EASTERN COLORADO WILL BE
THE FIRST ZONES TO HAVE ANY CHANCE THIS EVENING. WEAK DYNAMICS WILL
THEN SPREAD INTO NORTHWEST KANSAS/EXTREME SOUTHWEST NEBRASKA AFTER
06Z SUNDAY. AFTER A MORNING LULL, THERE WILL BE A CHANCE OF
THUNDERSTORMS ACROSS NORTHWEST KANSAS SUNDAY AFTERNOON GENERALLY
EAST OF GOODLAND.
BOUNDARY LAYER RH GETS HIGH ENOUGH TO SUPPORT PATCHY FOG OVER THE
SOUTHEAST ZONES LATE TONIGHT. TEMPERATURES TONIGHT WILL FALL TO THE
LOWER 50S. HIGHS SUNDAY WILL BE IN THE UPPER 70S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 220 PM MDT SAT SEP 29 2012
THE 12Z GFS AND ECMWF HAVE SLOWED THE PRE-FRONTAL SURFACE TROUGH DOWN
FOR SUNDAY TO WHAT THE NAM HAS BEEN SHOWING THE LAST COUPLE OF
DAYS. WITH THE LATEST GEFS MEMBERS ALSO SLOWING THE TROUGH DOWN
WILL KEEP HIGHER PRECIP. CHANCES OVER THE EASTERN 1/3 OF THE AREA SUNDAY EVENING.
EXTENDED THE SLIGHT CHANCES OVER THE EAST PAST MIDNIGHT DUE TO THE
SLOWER TROUGH PASSAGE. MEANWHILE A COOLER AIR MASS WILL BEGIN TO MOVE INTO
THE AREA DURING THE OVERNIGHT HOURS.
MONDAY DRIER AIR MOVES INTO THE AREA SO WILL CONTINUE TO LEAVE THE
FORECAST DRY DESPITE AN UPPER LEVEL SHORT WAVE TROUGH MOVING THROUGH
DURING THE AFTERNOON. SURFACE WINDS WILL STRENGTHEN DURING THE
AFTERNOON AS WINDS OF 20 TO 30 KTS MIX DOWN FROM 700MB.
MONDAY NIGHT WILL ALSO BE DRY AS A SURFACE AND UPPER LEVEL RIDGE
MOVE THROUGH AND POINT SOUNDINGS CONTINUE TO DRY OUT.
FOR THE TUESDAY THROUGH SATURDAY PERIOD MODELS ARE COMING INTO
BETTER AGREEMENT REGARDING THE TIMING OF THE UPPER LEVEL TROUGH
DROPPING DOWN FROM CANADA INTO THE CENTRAL PLAINS. CURRENT MODEL
RUNS HAVE THE TROUGH PASSING THROUGH THE AREA WEDNESDAY NIGHT...WITH
THE MAJORITY OF THE LIFT WITH THE TROUGH NORTH OF THE AREA. WITH
1000-500MB RELATIVE HUMIDITY INCREASING AS THE TROUGH MOVES
THROUGH...HAVE INTRODUCED PRECIP. CHANCES ALONG/NORTH OF THE
NEBRASKA LINE. THE TROUGH BROADENS DURING THE LATTER HALF OF THE
WORK WEEK AS ANOTHER SHORT WAVE TROUGH DIVES SOUTH ACROSS THE
PLAINS...PASSING OVER THE AREA SATURDAY. MODELS CURRENTLY PLACE THE
MAJORITY OF THE 1000-500MB RELATIVE HUMIDITY JUST NORTH OF THE AREA...SO
WILL KEEP PRECIP. CHANCES IN THE SILENT CATEGORY FOR NOW.
A STRONG COLD FRONT WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT.
BELOW NORMAL TEMPERATURES CAN BE EXPECTED AFTER WEDNESDAY AS THE COOLER AIR
MASS REMAINS OVER THE AREA. SOME LOCATIONS...ESPECIALLY THOSE IN
LOW LYING AREAS MAY SEE FROST FRIDAY AND SATURDAY MORNING AS LOW
TEMPERATURES APPROACH THE MID 30S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 553 PM MDT SAT SEP 29 2012
COMPLICATED SET OF TAFS. MODELS ARE SLOWER IN BRINGING SURFACE
TROUGH THROUGH THE AREA TONIGHT. AS A RESULT THE WINDS WILL
REMAIN FROM A SOUTH TO SOUTHEAST DIRECTION MOST OF THE NIGHT WHICH
SHOULD KEEP THE LOW LEVEL AIR MASS MOIST. BELIEVE MODELS ARE UNDERDOING
MOISTURE RETURN AS A RESULT. LATEST RUC AND NAM STILL HAVE THE
WIND SHIFT TO THE WEST OF KGLD AT 12Z. THOSE MODELS PLUS THE HRRR HAVE
STRATUS AND FOG FURTHER WEST THAN CURRENTLY DEPICTED. STRATUS AND
FOG WILL DEVELOP AFTER 06Z. SO PUT IN MVFR CEILINGS AND VISIBILITIES
UNTIL NEAR 15Z.
AT THAT TIME...SURFACE TROUGH AND MID LEVEL SHORTWAVE TROUGH WILL
BEGIN TO AFFECT THE AREA. MODELS SHOW A RATHER HIGH AMOUNT OF
ELEVATED CAPE AND NOT A LOT OF CINH. DEEP LIFT AND MOISTURE LOOK
TO CREATE A LINE OF THUNDERSTORMS DURING THE TIME. THE LINE LOOKS
TO FORM NEAR KGLD AND IS POSSIBLE THAT IT COULD FORM JUST EAST OF
KGLD. MORE SURE THAT KMCK WILL BE AFFECTED BY THUNDERSTORMS BY
MIDDAY. SINCE IT WILL BE CLOSE AT KGLD AND THUNDERSTORMS NOT
EXPECTED AT KMCK UNTIL THE LAST 6 HOURS OF THE PERIOD...CHOSE TO
ONLY HAVE VCTS AT THIS TIME. WILL ADJUST WITH THE NEWER DATA BUT
WOULD EXPECT THAT KMCK WILL HAVE A GOOD CHANCE TO BE AFFECTED BY
THUNDERSTORMS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
102 AM CDT FRI SEP 28 2012
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 100 AM CDT FRI SEP 28 2012
WV IMAGERY AND 00Z UPPER AIR ANALYSIS INDICATE AN UPPER LEVEL TROUGH
OF LOW PRESSURE PUSHING EAST ACROSS NORTHEASTERN COLORADO AND
WESTERN NEBRASKA. A +80KT UPPER LEVEL JET IS CLIMBING NORTHEAST OUT
OF THE DESERT SOUTHWEST INTO THE WESTERN HIGH PLAINS OF SOUTHWEST
KANSAS AND JUST NOSING INTO WESTERN MISSOURI. NEAR THE SURFACE,
AN AREA OF HIGH PRESSURE ACROSS THE UPPER MIDWEST IS HELPING
INFLUENCE AN EAST TO SOUTHEASTERLY UPSLOPE FLOW ACROSS WESTERN
KANSAS. SURFACE DEWPOINTS ARE PRIMARILY IN THE 50S(F) ACROSS CENTRAL
AND SOUTHWEST KANSAS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 237 PM
CDT THU SEP 27 2012
THE FIRST PRIORITY FOR THIS FORECAST IS THE CHANCE FOR SEVERE STORMS
VERY LATE THIS AFTERNOON AND THIS EVENING. TEMPERATURES AND WINDS
ARE OF A SECONDARY CONCERN. THE SPC DAY ONE OUTLOOK HAS OUR
SOUTHWEST CORNER, SOUTHWEST OF A HAMILTON TO GRANT TO SEWARD LINE,
IN A SLIGHT CHANCE. I THINK THERE COULD BE ONE OR TWO OR THREE
HAIL PRODUCERS IN OUR WEST/SOUTHWEST CORNER, BUT MAINLY AFTER 9 PM CDT.
THE HRRR MODEL HAS JUST MARGINAL CAPE THIS EVENING IN THE 1000
J/KG, THE RUC MODEL HAS LITTLE OR NO 0-6 KM HELICITY, AND FORECAST
SOUNDINGS FROM BOTH THE HRRR AND RUC MODELS FOR A POINT NEAR
RICHFIELD SHOW -5.8 LI`S BY 06Z. IF THERE IS SOME SEVERE, IT WILL
BE A LATE SHOW AFTER 9PM CDT. WE HELD A EMS/KDOT/FEMA CONTACTS,
AND TOLD THEM POSSIBLE HAILERS WITH UP TO GOLF BALL HAIL AFTER 7 PM
CDT, SO THEY SHOULD HAVE PLENTY OF NOTICE.
AFTER THE FIRST ROUND OF MARGINAL SEVERE CONVECTION, THERE IS A GOOD
WAVE MOVING EAST ACROSS OUR CWA AFTER MIDNIGHT. THEREFORE, THERE
WILL BE INCREASING POPS AFTER 06Z, FROM WEST TO EAST. THERE COULD
BE A GOOD WIDESPREAD RAIN EVENT, BUT DID NOT OVERDO THE RAINFALL
QPF SINCE HIGH RAINFALL AMOUNTS WILL SPOTTY SUCH AS THE LAST
SEVERAL PRECIPITATION EVENTS. LAST NIGHT, DOWN NEAR LIBERAL, WE
HAD ONE RAINFALL REPORT OF 3.50 INCHES 2 MILES SOUTH OF LIBERAL
AND ANOTHER REPORT OF 2.61 INCHES OF RAIN FROM THE SOUTH-SOUTHWEST
EDGE OF ROLLA. SO, WIDESPREAD RAIN LIKE THAT IS NOT EXPECTED
AGAIN. THE RUC13 MODEL SOUNDING FOR NEAR ELKHART SHOWED 1.13
INCHES AT 06Z. OUR EASTERN CWA SHOULD STAY CLOUDY TONIGHT WITH
3-5SM FOG, AND THE WEST WILL LIKELY SEE EVEN LOWER LEVEL CLOUDS
IN THE EASTERLY UPSLOPE FLOW. TEMPERATURES WILL NOT FALL QUICKLY
UNDER THE THICK CLOUDS, AND SHOULD ONLY BOTTOM OUT IN THE MID 50S
IN THE WEST AND THE LOWER 60S IN THE SOUTHEAST.
FRIDAY COULD STILL BE WET WITH SCATTERED SHOWERS AND THUNDERSTORMS,
WITH THE BETTER CHANCE IN OUR EASTERN COUNTIES EAST OF A LINE FROM
HAYS TO DODGE CITY TO ASHLAND. THIS MAY BE AN EARLY MORNING THEN
ANOTHER ROUND OF RAIN IN THE AFTERNOON EVENT. POPS WILL BE 40 TO
50 PERCENT EAST OF THAT LINE ABOVE, WITH 30 TO 40 POPS WEST OF THAT
LINE. HOW MUCH RAIN IS ALWAYS THE QUESTION CALLERS SEEM TO ASK,
BUT DO NOT THINK ANY ADDITIONAL HEAVY RAIN WILL FALL ON FRIDAY. THE
UPPER SUPPORT WILL BE PULLING EAST DURING THE AFTERNOON, AND THE
SURFACE FRONT SHOULD BE MOVING SOUTH OUT OF OUR CWA DURING THE
AFTERNOON. LIGHT BUT STEADY UPSLOPE FLOW WILL BE THE MAIN SOURCE
OF PRECIPITATION FRIDAY. FRIDAY AFTERNOON SHOULD BE ANOTHER COOL
ONE, AS TEMPERATURES WILL STRUGGLE TO REACH THE MID 70S IN OUR
EASTERN ZONES OF ELLIS, EDWARDS AND CLARK COUNTIES (AND EAST) AND
IN THE LOWER 70S TO DOWN NEAR 70F DEGREES OUT WEST NEAR THE
COLORADO BORDER NEAR THE STRONGEST UPSLOPE AFFECT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 PM CDT THU SEP 27 2012
FRIDAY NIGHT:
CONVECTION WILL QUICKLY BE ON THE WANE FRIDAY EVENING AS A 90 KT
250 HPA JET STREAK TRAVERSES QUICKLY ACROSS THE STATE AND AS DIURNAL
INSTABILITY RAPIDLY DIMINISHES. AS A RESULT, HAVE RAMPED POPS DOWN SOONER
ACROSS THE REGION BETWEEN FRIDAY EVENING AND TOWARDS MIDNIGHT SATURDAY.
THE NEXT SENSIBLE WEATHER CONCERN HEADING INTO SATURDAY MORNING IS FOG.
BUFKIT/BUFR FORECAST SOUNDINGS SHOW AN ENVIRONMENT THAT IS CONDUCIVE
FOR RADIATIONAL FOG. THIS IS A RESULT OF HIGH PRESSURE BUILDING IN ACROSS
KANSAS AND WINDS BECOMING LIGHT OR EVEN CALM. HAVE INSERTED AREAS OF
FOG IN THE WX GRIDS AS BETTER CONFIDENCE OF FOG VIA THE AFOREMENTIONED
SOUNDINGS AND PLAN VIEW RH PROGS IN THE BOUNDARY LAYER.
SATURDAY THROUGH NEXT THURSDAY:
THE FORECAST WILL BE FAIRLY DRY THROUGH MUCH OF THE PERIOD IN ASSOCIATION
WITH UPPER LEVEL RIDGING, THE WARM PLUME SPREADING EAST, AND LACK OF
REAL SURFACE MOISTURE & CONVERGENCE. THE EXCEPTION TO THIS IS SUNDAY
EVENING. A SHORTWAVE TROUGH SKIRTING ACROSS THE NORTHERN PRAIRIES WILL
USHER IN A COLD FRONT/TROF AXIS WHICH COULD BE THE IMPETUS FOR CONVECTION
DURING THE AFTERNOON AND EARLY EVENING. WILL MAINLY USE THE 12Z ECMWF
FOR GUIDANCE IN CONCERNING THIS CONVECTION FOR NOW. SLIGHT POPS LOOK
REASONABLE FOR NOW AND RESULTED IN NOT MUCH CHANGE FROM THE PREVIOUS
FORECAST.
OTHERWISE, RELATIVELY HIGH 500 HPA HEIGHTS ARE EXPECTED ACROSS WESTERN
KANSAS FOR MUCH OF NEXT WEEK. THE FLOW WILL BECOME MORE PERPENDICULAR
TO THE ROCKIES BY MIDWEEK NEXT WEEK WHICH WILL RESULT IN LOWERING PRESSURES
ACROSS THE LEE OF THE ROCKIES AND A CONTINUED WARM AIR ADVECTION PATTERN
THROUGH THE LOWER ATMOSPHERE. AS A RESULT, EXPECT MODERATING TEMPERATURES
THROUGH NEXT WEEK WITH NEAR TO ABOVE NORMAL HIGHS. THE 12Z ECMWF IS
SHOWING A FAIRLY STRONG COLD FRONT TRAVERSING ACROSS THE KANSAS PRAIRIES
BY NEXT THURSDAY. WILL NOT STRAY FROM WHAT THE ALLBLEND GIVES ME AS
THE VALUES LOOK REASONABLE WITH HIGHS COOLING DOWN INTO THE 70S DEG
F. UPPER LEVEL JET DYNAMICS WITH THIS FRONT LOOKS TO BE FAIRLY BROAD
AND ELONGATED SO ANY SIGNIFICANT SYNOPTIC SCALE LIFT AND ASSOCIATED
RESULTANT PRECIPITATION LOOKS TO REMAIN NORTH OF THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1200 AM CDT FRI SEP 28 2012
SHOWERS AND THUNDERSTORMS IN WEST CENTRAL AND SOUTHWEST KANSAS
WILL CONTINUE TO TRACK EAST-SOUTHEAST INTO CENTRAL AND SOUTH
CENTRAL KANSAS OVERNIGHT. MVFR CIGS/VSBYS WILL BE POSSIBLE WITH
THE HEAVIEST RAINFALL. OTHERWISE, LOW LEVEL STRATUS IS EXPECTED
TO DEVELOP LATER TONIGHT WITHIN A MOIST EAST TO SOUTHEASTERLY
UPSLOPE FLOW ACROSS SOUTHWEST AND PORTIONS OF SOUTH CENTRAL KANSAS.
MVFR CIGS/VSBYS ARE LIKELY IN THE VICINITY AND SOUTH OF KGCK AND
KDDC...GENERALLY AFTER 07Z...WITH IFR CIGS/VSBYS POSSIBLE TOWARD
DAYBREAK. CONDITIONS ARE THEN EXPECTED TO GRADUALLY IMPROVE
THROUGH MID TO LATE MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 75 55 76 54 / 50 20 10 10
GCK 73 54 75 54 / 40 20 10 10
EHA 72 53 76 54 / 30 20 10 10
LBL 74 55 76 54 / 40 20 10 10
HYS 75 53 76 53 / 40 20 10 10
P28 77 58 77 56 / 50 30 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJOHNSON
SHORT TERM...BURKE
LONG TERM...SUGDEN
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1205 AM CDT FRI SEP 28 2012
...UPDATE TO AVIATION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW) ISSUED AT 237 PM
CDT THU SEP 27 2012
THE FIRST PRIORITY FOR THIS FORECAST IS THE CHANCE FOR SEVERE STORMS
VERY LATE THIS AFTERNOON AND THIS EVENING. TEMPERATURES AND WINDS
ARE OF A SECONDARY CONCERN. THE SPC DAY ONE OUTLOOK HAS OUR
SOUTHWEST CORNER, SOUTHWEST OF A HAMILTON TO GRANT TO SEWARD LINE,
IN A SLIGHT CHANCE. I THINK THERE COULD BE ONE OR TWO OR THREE
HAIL PRODUCERS IN OUR WEST/SOUTHWEST CORNER, BUT MAINLY AFTER 9 PM CDT.
THE HRRR MODEL HAS JUST MARGINAL CAPE THIS EVENING IN THE 1000
J/KG, THE RUC MODEL HAS LITTLE OR NO 0-6 KM HELICITY, AND FORECAST
SOUNDINGS FROM BOTH THE HRRR AND RUC MODELS FOR A POINT NEAR
RICHFIELD SHOW -5.8 LI`S BY 06Z. IF THERE IS SOME SEVERE, IT WILL
BE A LATE SHOW AFTER 9PM CDT. WE HELD A EMS/KDOT/FEMA CONTACTS,
AND TOLD THEM POSSIBLE HAILERS WITH UP TO GOLF BALL HAIL AFTER 7 PM
CDT, SO THEY SHOULD HAVE PLENTY OF NOTICE.
AFTER THE FIRST ROUND OF MARGINAL SEVERE CONVECTION, THERE IS A GOOD
WAVE MOVING EAST ACROSS OUR CWA AFTER MIDNIGHT. THEREFORE, THERE
WILL BE INCREASING POPS AFTER 06Z, FROM WEST TO EAST. THERE COULD
BE A GOOD WIDESPREAD RAIN EVENT, BUT DID NOT OVERDO THE RAINFALL
QPF SINCE HIGH RAINFALL AMOUNTS WILL SPOTTY SUCH AS THE LAST
SEVERAL PRECIPITATION EVENTS. LAST NIGHT, DOWN NEAR LIBERAL, WE
HAD ONE RAINFALL REPORT OF 3.50 INCHES 2 MILES SOUTH OF LIBERAL
AND ANOTHER REPORT OF 2.61 INCHES OF RAIN FROM THE SOUTH-SOUTHWEST
EDGE OF ROLLA. SO, WIDESPREAD RAIN LIKE THAT IS NOT EXPECTED
AGAIN. THE RUC13 MODEL SOUNDING FOR NEAR ELKHART SHOWED 1.13
INCHES AT 06Z. OUR EASTERN CWA SHOULD STAY CLOUDY TONIGHT WITH
3-5SM FOG, AND THE WEST WILL LIKELY SEE EVEN LOWER LEVEL CLOUDS
IN THE EASTERLY UPSLOPE FLOW. TEMPERATURES WILL NOT FALL QUICKLY
UNDER THE THICK CLOUDS, AND SHOULD ONLY BOTTOM OUT IN THE MID 50S
IN THE WEST AND THE LOWER 60S IN THE SOUTHEAST.
FRIDAY COULD STILL BE WET WITH SCATTERED SHOWERS AND THUNDERSTORMS,
WITH THE BETTER CHANCE IN OUR EASTERN COUNTIES EAST OF A LINE FROM
HAYS TO DODGE CITY TO ASHLAND. THIS MAY BE AN EARLY MORNING THEN
ANOTHER ROUND OF RAIN IN THE AFTERNOON EVENT. POPS WILL BE 40 TO
50 PERCENT EAST OF THAT LINE ABOVE, WITH 30 TO 40 POPS WEST OF THAT
LINE. HOW MUCH RAIN IS ALWAYS THE QUESTION CALLERS SEEM TO ASK,
BUT DO NOT THINK ANY ADDITIONAL HEAVY RAIN WILL FALL ON FRIDAY. THE
UPPER SUPPORT WILL BE PULLING EAST DURING THE AFTERNOON, AND THE
SURFACE FRONT SHOULD BE MOVING SOUTH OUT OF OUR CWA DURING THE
AFTERNOON. LIGHT BUT STEADY UPSLOPE FLOW WILL BE THE MAIN SOURCE
OF PRECIPITATION FRIDAY. FRIDAY AFTERNOON SHOULD BE ANOTHER COOL
ONE, AS TEMPERATURES WILL STRUGGLE TO REACH THE MID 70S IN OUR
EASTERN ZONES OF ELLIS, EDWARDS AND CLARK COUNTIES (AND EAST) AND
IN THE LOWER 70S TO DOWN NEAR 70F DEGREES OUT WEST NEAR THE
COLORADO BORDER NEAR THE STRONGEST UPSLOPE AFFECT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 345 PM CDT THU SEP 27 2012
FRIDAY NIGHT:
CONVECTION WILL QUICKLY BE ON THE WANE FRIDAY EVENING AS A 90 KT
250 HPA JET STREAK TRAVERSES QUICKLY ACROSS THE STATE AND AS DIURNAL
INSTABILITY RAPIDLY DIMINISHES. AS A RESULT, HAVE RAMPED POPS DOWN SOONER
ACROSS THE REGION BETWEEN FRIDAY EVENING AND TOWARDS MIDNIGHT SATURDAY.
THE NEXT SENSIBLE WEATHER CONCERN HEADING INTO SATURDAY MORNING IS FOG.
BUFKIT/BUFR FORECAST SOUNDINGS SHOW AN ENVIRONMENT THAT IS CONDUCIVE
FOR RADIATIONAL FOG. THIS IS A RESULT OF HIGH PRESSURE BUILDING IN ACROSS
KANSAS AND WINDS BECOMING LIGHT OR EVEN CALM. HAVE INSERTED AREAS OF
FOG IN THE WX GRIDS AS BETTER CONFIDENCE OF FOG VIA THE AFOREMENTIONED
SOUNDINGS AND PLAN VIEW RH PROGS IN THE BOUNDARY LAYER.
SATURDAY THROUGH NEXT THURSDAY:
THE FORECAST WILL BE FAIRLY DRY THROUGH MUCH OF THE PERIOD IN ASSOCIATION
WITH UPPER LEVEL RIDGING, THE WARM PLUME SPREADING EAST, AND LACK OF
REAL SURFACE MOISTURE & CONVERGENCE. THE EXCEPTION TO THIS IS SUNDAY
EVENING. A SHORTWAVE TROUGH SKIRTING ACROSS THE NORTHERN PRAIRIES WILL
USHER IN A COLD FRONT/TROF AXIS WHICH COULD BE THE IMPETUS FOR CONVECTION
DURING THE AFTERNOON AND EARLY EVENING. WILL MAINLY USE THE 12Z ECMWF
FOR GUIDANCE IN CONCERNING THIS CONVECTION FOR NOW. SLIGHT POPS LOOK
REASONABLE FOR NOW AND RESULTED IN NOT MUCH CHANGE FROM THE PREVIOUS
FORECAST.
OTHERWISE, RELATIVELY HIGH 500 HPA HEIGHTS ARE EXPECTED ACROSS WESTERN
KANSAS FOR MUCH OF NEXT WEEK. THE FLOW WILL BECOME MORE PERPENDICULAR
TO THE ROCKIES BY MIDWEEK NEXT WEEK WHICH WILL RESULT IN LOWERING PRESSURES
ACROSS THE LEE OF THE ROCKIES AND A CONTINUED WARM AIR ADVECTION PATTERN
THROUGH THE LOWER ATMOSPHERE. AS A RESULT, EXPECT MODERATING TEMPERATURES
THROUGH NEXT WEEK WITH NEAR TO ABOVE NORMAL HIGHS. THE 12Z ECMWF IS
SHOWING A FAIRLY STRONG COLD FRONT TRAVERSING ACROSS THE KANSAS PRAIRIES
BY NEXT THURSDAY. WILL NOT STRAY FROM WHAT THE ALLBLEND GIVES ME AS
THE VALUES LOOK REASONABLE WITH HIGHS COOLING DOWN INTO THE 70S DEG
F. UPPER LEVEL JET DYNAMICS WITH THIS FRONT LOOKS TO BE FAIRLY BROAD
AND ELONGATED SO ANY SIGNIFICANT SYNOPTIC SCALE LIFT AND ASSOCIATED
RESULTANT PRECIPITATION LOOKS TO REMAIN NORTH OF THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1200 AM CDT FRI SEP 28 2012
SHOWERS AND THUNDERSTORMS IN WEST CENTRAL AND SOUTHWEST KANSAS
WILL CONTINUE TO TRACK EAST-SOUTHEAST INTO CENTRAL AND SOUTH
CENTRAL KANSAS OVERNIGHT. MVFR CIGS/VSBYS WILL BE POSSIBLE WITH
THE HEAVIEST RAINFALL. OTHERWISE, LOW LEVEL STRATUS IS EXPECTED
TO DEVELOP LATER TONIGHT WITHIN A MOIST EAST TO SOUTHEASTERLY
UPSLOPE FLOW ACROSS SOUTHWEST AND PORTIONS OF SOUTH CENTRAL KANSAS.
MVFR CIGS/VSBYS ARE LIKELY IN THE VICINITY AND SOUTH OF KGCK AND
KDDC...GENERALLY AFTER 07Z...WITH IFR CIGS/VSBYS POSSIBLE TOWARD
DAYBREAK. CONDITIONS ARE THEN EXPECTED TO GRADUALLY IMPROVE
THROUGH MID TO LATE MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 58 73 56 76 / 60 50 20 10
GCK 56 71 55 75 / 60 40 10 10
EHA 55 72 55 76 / 70 40 10 10
LBL 56 73 56 76 / 70 50 20 10
HYS 56 73 55 76 / 40 50 10 10
P28 60 75 60 77 / 50 60 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BURKE
LONG TERM...SUGDEN
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1025 PM EDT SAT SEP 29 2012
.SYNOPSIS...
AN UPPER LEVEL LOW WILL BRING SHOWERS TO THE AREA LATE TONIGHT
THROUGH MUCH OF THE DAY ON SUNDAY. A FEW THUNDERSTORMS WILL BE
POSSIBLE WITH SHOWERS SUNDAY AFTERNOON. HIGH PRESSURE WILL THEN
RETURN DRY CONDITIONS FOR MONDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
03Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
ADD MORE PATCHY FOG FOR LOCATIONS PRIMARILY SOUTHWEST OF
PITTSBURGH. THE REST OF THE PREVIOUS DISCUSSION REMAINS THE SAME.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB CLOSED LOW
CENTERED JUST EAST OF LAKE HURON IN ONTARIO. AN AXIS OF MID-LEVEL
MOISTURE EXTENDS SOUTHWARD OF THE LOW INTO WESTERN PA. THE
CYCLONIC FLOW AROUND THE LOW IS ADVECTING THAT MOISTURE EASTWARD
WITH DRIER AIR UPSTREAM IN OHIO. VORT ENERGY IS SWINGING AROUND
THE LOW...ACROSS LAKE ERIE...AND PROVIDING FORCING FOR SCATTERED
SHOWERS IN NORTHEAST OHIO AND NORTHWEST PA.
TONIGHT...THE UPPER LOW WILL SLIDE SOUTHWARD ACROSS LAKE ERIE AND
INTO WESTERN PA BY DAWN. VORT LOBE OF ENERGY WILL SHIFT INTO
EASTERN OHIO AND INCREASE THE CHANCES FOR SHOWERS OVERNIGHT...ESPECIALLY
FOR LOCATIONS ALONG AND NORTH OF THE I-70 CORRIDOR. POPS OVERNIGHT
INCREASE FROM SCHC EARLY TO LIKELY BY DAWN ACROSS THE I-80
CORRIDOR. AS THE DRIER AIR ADVECTS IN FROM OHIO SOME CLEARING WILL
OCCUR FOR EASTERN OHIO AND NORTHERN WV. THIS WILL ALLOW FOR SOME
PATCHY RADIATIONAL FOG TO DEVELOP WITH NEAR CALM WINDS. TEMPS
OVERNIGHT ARE A HRRR/LAMP BLEND...WITH LOWS IN THE LOWER TO MID
40S ACROSS THE AREA.
SUNDAY...THE UPPER LOW WILL PIVOT FROM WESTERN PA INTO NY. THE
BEST FORCING WITH THE LOW WILL CROSS THE AREA IN THE 12Z-21Z
WINDOW AS VORT ENERGY SWINGS ACROSS THE AREA. INCREASING
INSTABILITY TO AROUND 300-500 J/KG SBCAPE WITH COOL TEMPS ALOFT
(0C AROUND 7KFT) WILL SUPPORT THE SCHC OF THUNDERSTORMS IN THE
LATE MORNING INTO THE AFTERNOON. WITH COOLER TEMPS ALOFT...NOT
OUT OF THE QUESTION THAT GRAUPEL OR SMALL HAIL WOULD BE POSSIBLE
IN THE STRONGER SHOWERS OR STORMS. CLOUD COVERAGE ALONG WITH
COOLER AIR ADVECTING INTO THE AREA WITH THE LOW WILL KEEP TEMPS
DOWN FOR HIGHS. HIGHS ARE A FEW DEGREES COOLER THAN A MAV/MET
BLEND ACROSS MOST OF THE AREA, RANGING FROM MID 50S ALONG THE I-80
CORRIDOR TO THE MID 60S ACROSS THE LOWLANDS SOUTH OF I-70.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
UPPER LOW WILL PUSH EAST SUNDAY NIGHT...AND AS HIGH PRESSURE EDGES
IN FROM THE WEST...HARD TO SAY HOW FAR LOW TEMPS WILL DROP SUNDAY
NIGHT. IF CLOUDS BREAK EARLY ENOUGH...LOWS COULD EASILY DROP 5
DEGREES BELOW CURRENT FORECAST. INFLUENCE OF HIGH PRESSURE WILL BE
SHORT LIVED AS SURFACE LOW PRESSURE DEVELOPS ALONG THE LOWER
MISSISSIPPI AND MOVES NORTHEAST. STILL LOTS OF UNCERTAINTY WITH THE
SYSTEM...INCLUDING INITIAL TIMING...AMOUNT OF RAIN...AND LOCATION OF
HEAVIEST RAINFALL. ENSEMBLES SEEM AWFULLY FAST BRINGING THE RAIN
IN...AND HAVE STUCK CLOSER TO NAM/GFS TIMING...WHICH KEEPS MOST
PLACES DRY UNTIL LATE MONDAY EVENING. WILL NOT GET FANCY WITH
LOCATION/TIMING OF HIGHEST QPF FOR NOW...BUT SOME LOCATIONS SHOULD
BE A GOOD BET TO GET AT LEAST A HALF INCH OF RAIN. SOUTHEASTERLY
FLOW WILL ALLOW FOR SOME TEMPERATURE RECOVERY...BRINGING HIGHS BACK
INTO THE MID/UPPER 60S AND LOWER 70S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
SHORT WAVE IN THE NORTHERN BRANCH MERGES WITH THE SOUTHERN BRANCH
LOW TUESDAY EVENING IN THE WESTERN OHIO VALLEY AND WILL BRING
SHOWERS FOR TUESDAY NIGHT INTO WEDNESDAY. THE UPPER LOW PUSHES
INTO NEW YORK STATE BY WEDNESDAY EVENING...ENDING THE SHOWERS
ACROSS THE FORECAST AREA. HIGH PRESSURE BUILDING INTO THE DISTRICT
THURSDAY WILL BRING DRY WEATHER INTO THURSDAY NIGHT. A WEAK COLD
FRONT PASSING ACROSS THE DISTRICT FRIDAY WILL BRING A CHANCE OF
SHOWERS. HIGH PRESSURE BEHIND THE FRONT WILL BRING A RETURN OF DRY
WEATHER FOR SATURDAY.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS CAN BE EXPECTED FOR TONIGHT WITH BROKEN STRATOCU VFR
CEILINGS AND A FEW STRAY SHOWERS. PASSING UPPER LEVEL LOW CENTER
WILL PROVIDE SCATTERED SHOWERS SUNDAY AND EARLY SUNDAY NIGHT WITH
TIMES OF MVFR POSSIBLE BUT COVERAGE EXPECTED TO BE ENOUGH FOR
INCLUSION IN TERMINALS. WITH COLD TEMPERATURES ALOFT ISOLATED
THUNDERSTORMS ALSO POSSIBLE.
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
SHOWERS WILL CONTINUE INTO THE FIRST HALF OF SUNDAY NIGHT FOLLOWED
BY POSSIBLE PATCHY IFR FOG AND STRATUS. GENERAL VFR RETURNS FOR
DAYTIME MONDAY...BUT A LOW PRESSURE SYSTEM WILL PROVIDE SHOWERS AND
POSSIBLE RESTRICTIONS MONDAY NIGHT INTO WEDNESDAY. VFR RETURNS
WEDNESDAY NIGHT INTO THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...
LONG TERM...
AVIATION...RES
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
816 PM EDT SAT SEP 29 2012
.SYNOPSIS...
AN UPPER LEVEL LOW WILL BRING SHOWERS TO THE AREA LATE TONIGHT
THROUGH MUCH OF THE DAY ON SUNDAY. A FEW THUNDERSTORMS WILL BE
POSSIBLE WITH SHOWERS SUNDAY AFTERNOON. HIGH PRESSURE WILL THEN
RETURN DRY CONDITIONS FOR MONDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
00Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO MAKE
THE ONSET OF SHOWERS EARLIER TONIGHT.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB CLOSED LOW
CENTERED JUST EAST OF LAKE HURON IN ONTARIO. AN AXIS OF MID-LEVEL
MOISTURE EXTENDS SOUTHWARD OF THE LOW INTO WESTERN PA. THE
CYCLONIC FLOW AROUND THE LOW IS ADVECTING THAT MOISTURE EASTWARD
WITH DRIER AIR UPSTREAM IN OHIO. VORT ENERGY IS SWINGING AROUND
THE LOW...ACROSS LAKE ERIE...AND PROVIDING FORCING FOR SCATTERED
SHOWERS IN NORTHEAST OHIO AND NORTHWEST PA.
TONIGHT...THE UPPER LOW WILL SLIDE SOUTHWARD ACROSS LAKE ERIE AND
INTO WESTERN PA BY DAWN. VORT LOBE OF ENERGY WILL SHIFT INTO
EASTERN OHIO AND INCREASE THE CHANCES FOR SHOWERS OVERNIGHT...ESPECIALLY
FOR LOCATIONS ALONG AND NORTH OF THE I-70 CORRIDOR. POPS OVERNIGHT
INCREASE FROM SCHC EARLY TO LIKELY BY DAWN ACROSS THE I-80
CORRIDOR. AS THE DRIER AIR ADVECTS IN FROM OHIO SOME CLEARING WILL
OCCUR FOR LOCATIONS SOUTH OF I-70. THIS WILL ALLOW FOR SOME PATCHY
RADIATIONAL FOG TO DEVELOP WITH NEAR CALM WINDS. TEMPS OVERNIGHT
ARE A HRRR/LAMP BLEND...WITH LOWS IN THE LOWER TO MID 40S ACROSS
THE AREA.
SUNDAY...THE UPPER LOW WILL PIVOT FROM WESTERN PA INTO NY. THE
BEST FORCING WITH THE LOW WILL CROSS THE AREA IN THE 12Z-21Z
WINDOW AS VORT ENERGY SWINGS ACROSS THE AREA. INCREASING
INSTABILITY TO AROUND 300-500 J/KG SBCAPE WITH COOL TEMPS ALOFT
(0C AROUND 7KFT) WILL SUPPORT THE SCHC OF THUNDERSTORMS IN THE
LATE MORNING INTO THE AFTERNOON. WITH COOLER TEMPS ALOFT...NOT
OUT OF THE QUESTION THAT GRAUPEL OR SMALL HAIL WOULD BE POSSIBLE
IN THE STRONGER SHOWERS OR STORMS. CLOUD COVERAGE ALONG WITH
COOLER AIR ADVECTING INTO THE AREA WITH THE LOW WILL KEEP TEMPS
DOWN FOR HIGHS. HIGHS ARE A FEW DEGREES COOLER THAN A MAV/MET
BLEND ACROSS MOST OF THE AREA, RANGING FROM MID 50S ALONG THE I-80
CORRIDOR TO THE MID 60S ACROSS THE LOWLANDS SOUTH OF I-70.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
UPPER LOW WILL PUSH EAST SUNDAY NIGHT...AND AS HIGH PRESSURE EDGES
IN FROM THE WEST...HARD TO SAY HOW FAR LOW TEMPS WILL DROP SUNDAY
NIGHT. IF CLOUDS BREAK EARLY ENOUGH...LOWS COULD EASILY DROP 5
DEGREES BELOW CURRENT FORECAST. INFLUENCE OF HIGH PRESSURE WILL BE
SHORT LIVED AS SURFACE LOW PRESSURE DEVELOPS ALONG THE LOWER
MISSISSIPPI AND MOVES NORTHEAST. STILL LOTS OF UNCERTAINTY WITH THE
SYSTEM...INCLUDING INITIAL TIMING...AMOUNT OF RAIN...AND LOCATION OF
HEAVIEST RAINFALL. ENSEMBLES SEEM AWFULLY FAST BRINGING THE RAIN
IN...AND HAVE STUCK CLOSER TO NAM/GFS TIMING...WHICH KEEPS MOST
PLACES DRY UNTIL LATE MONDAY EVENING. WILL NOT GET FANCY WITH
LOCATION/TIMING OF HIGHEST QPF FOR NOW...BUT SOME LOCATIONS SHOULD
BE A GOOD BET TO GET AT LEAST A HALF INCH OF RAIN. SOUTHEASTERLY
FLOW WILL ALLOW FOR SOME TEMPERATURE RECOVERY...BRINGING HIGHS BACK
INTO THE MID/UPPER 60S AND LOWER 70S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
SHORT WAVE IN THE NORTHERN BRANCH MERGES WITH THE SOUTHERN BRANCH
LOW TUESDAY EVENING IN THE WESTERN OHIO VALLEY AND WILL BRING
SHOWERS FOR TUESDAY NIGHT INTO WEDNESDAY. THE UPPER LOW PUSHES
INTO NEW YORK STATE BY WEDNESDAY EVENING...ENDING THE SHOWERS
ACROSS THE FORECAST AREA. HIGH PRESSURE BUILDING INTO THE DISTRICT
THURSDAY WILL BRING DRY WEATHER INTO THURSDAY NIGHT. A WEAK COLD
FRONT PASSING ACROSS THE DISTRICT FRIDAY WILL BRING A CHANCE OF
SHOWERS. HIGH PRESSURE BEHIND THE FRONT WILL BRING A RETURN OF DRY
WEATHER FOR SATURDAY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS CAN BE EXPECTED FOR TONIGHT WITH BROKEN STRATOCU
CEILINGS. THE STRATOCU WILL DIMINISH AFTER SUNSET WITH SOME
SUFFICIENT RADIATIONAL COOLING TO PROMOTE MVFR FOG AROUND DAYBREAK
SUNDAY.
.OUTLOOK.../SUNDAY THROUGH THURSDAY/...
PASSING UPPER LEVEL LOW CENTER WILL PROVIDE SCATTERED SHOWERS SUNDAY
AND EARLY SUNDAY NIGHT WITH TIMES OF MVFR POSSIBLE. FOR NOW LEFT OUT
OF TERMINALS AS MAY BE BRIEF. PATCHY IFR FOG AND STRATUS POSSIBLE
LATE SUNDAY NIGHT. VFR RETURNS FOR DAYTIME MONDAY...BUT A LOW
PRESSURE SYSTEM WILL PROVIDE SHOWERS AND POSSIBLE RESTRICTIONS
TUESDAY INTO WEDNESDAY. VFR RETURNS WEDNESDAY NIGHT INTO THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
SHORT TERM...
LONG TERM...
AVIATION...RES
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1126 PM EDT SAT SEP 29 2012
.SYNOPSIS...
ISSUED AT 316 PM EDT SAT SEP 29 2012
ONE AREA OF LOW PRESSURE WILL DEVELOP OVER NEW ENGLAND TONIGHT AND
SUNDAY. THIS SYSTEM WILL BE TO FAR EAST TO CREATE RAIN HERE IN
WESTERN MICHIGAN. HIGH PRESSURE IN ONTARIO WILL BUILD SOUTH
INTO WESTERN LOWER MICHIGAN CREATING FAIR CONDITIONS WITH COOL
NIGHTS AND NEAR SEASONABLY WARM DAYS INTO MONDAY. A WEAK COLD FRONT
WILL APPROACH THE REGION FROM THE NORTHWEST TUESDAY INTO WEDNESDAY
AS A LOW PRESSURE SYSTEM LIFTS OUT OF THE GULF OF MEXICO. AS A
RESULT THE REGION MAY SEE SOME SHOWERS ARRIVING.
&&
.UPDATE...
ISSUED AT 1027 PM EDT SAT SEP 29 2012
NOT TOO CONCERNED WITH FROST POTENTIAL TONIGHT. MIXING REMAINS UP
THROUGH THE NIGHT AND IT SEEMS FAIRLY LIKELY THAT SC WILL ENCROACH
MUCH OF THE NE CWA BY MORNING. EVEN IF THE CLOUDS WERE TO BE THIN
OR SCATTERED BELIEVE FROST THREAT IS VERY LOW. COULD BE REMOTE POCKETS
OVER THE INTERIOR NORTH...BUT IT SHOULD BE TOO ISOLATED FOR ANY
HEADLINE. INCREASED MIN TEMPS FOR OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 316 PM EDT SAT SEP 29 2012
THE MAIN CHALLENGE DEALS WITH THE RISK FOR FROST TONIGHT. OVERALL
THE TREND OF TRACKING/FORMING THE SURFACE LOW FURTHER EAST
CONTINUES. LOOKS LIKE IT WILL END UP OVER NEW ENGLAND. HERE IN WRN
LOWER MI...SKIES WILL FEATURE MUCH LESS CLOUD COVER AS A RESULT IT
APPEARS. THIS OPENS UP THE RISK FOR FROST ESPECIALLY WITH HIGH
PRESSURE NOW SHOWN TO DROP SOUTHWARD OUT OF ONTARIO. HOWEVER THE
HRRR RUC AND EVEN THE NAM ARE SHOWING LOW LEVEL MOISTURE AND A
RISK FOR STRATUS TO DEVELOP OVER NORTHEAST LOWER TONIGHT...THEN
DROP SOUTHWEST AND EXPAND INTO SOUTHWEST LOWER MI LATE TONIGHT.
WILL KEEP THE FROST OUT OF THE FORECAST FOR NOW...BUT THIS SHOULD
BE MONITORED CLOSELY AS HEADLINES MAY BE REQUIRED IF THE CLOUDS DO
NOT DEVELOP.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 316 PM EDT SAT SEP 29 2012
TEMPS WILL AVERAGE ABOVE NORMAL TUESDAY BUT SOME CLOUDS FROM LOW
PRESSURE TRACKING NE THROUGH THE OH VALLEY REGION WILL MOVE IN. WE
HAVE INTRODUCED MENTION OF A SLIGHT CHC OF LIGHT RAIN SHOWERS FROM
TUESDAY AFTERNOON THROUGH TUESDAY NIGHT INTO WEDNESDAY IN
ASSOCIATION WITH THAT SYSTEM (MAINLY SE OF GRR).
TEMPS WILL REMAIN ABOVE NORMAL WEDNESDAY THROUGH THURSDAY AFTERNOON
AS FLOW BECOMES SOUTHWESTERLY IN ADVANCE OF A STRONG COLD FRONT.
THAT LOW PRESSURE SYSTEM AND COLD FRONT WILL BRING A CHC OF SHOWERS
THURSDAY NIGHT THROUGH FRIDAY. AN UNSEASONABLY COOL AIRMASS WILL
MOVE IN BEHIND THAT FRONT FRIDAY THROUGH SATURDAY WHEN HIGH TEMPS
WILL ONLY REACH THE 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1125 PM EDT SAT SEP 29 2012
LITTLE CHANGE TO THE GOING FORECAST. STRATOCU CONTINUES TO DEVELOP
OVER LAKE HURON AND IS MOVING SWWD. WE CONTINUED THE MVFR CIGS AT
KLAN/KJXN LATE TONIGHT. THE REST OF THE TAFS SHOULD REMAIN VFR.
&&
.MARINE...
ISSUED AT 316 PM EDT SAT SEP 29 2012
WAVES WILL BE BUILDING AN REACH VALUES CLOSE TO SMALL CRAFT
ADVISORY CRITERIA TONIGHT UP AROUND LITTLE AND BIG SABLE POINTS.
THEN ON SUNDAY AS A NORTHERLY FLOW PERSISTS...WAVES SOUTH OF SOUTH
HAVEN WILL ALSO END UP CLOSE TO CRITERIA. I THOUGHT MOST VALUES
WOULD BE JUST UNDER CRITERIA SO NO HEADLINE AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 316 PM EDT SAT SEP 29 2012
NO HYDRO ISSUES EXPECTED. ANY RAINFALL IS FORECASTED TO BE LIMITED
AND NOT ENOUGH TO CAUSE SIGNIFICANT RISES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...JK
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...LAURENS
AVIATION...93
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1027 PM EDT SAT SEP 29 2012
.SYNOPSIS...
ISSUED AT 316 PM EDT SAT SEP 29 2012
ONE AREA OF LOW PRESSURE WILL DEVELOP OVER NEW ENGLAND TONIGHT AND
SUNDAY. THIS SYSTEM WILL BE TO FAR EAST TO CREATE RAIN HERE IN
WESTERN MICHIGAN. HIGH PRESSURE IN ONTARIO WILL BUILD SOUTH
INTO WESTERN LOWER MICHIGAN CREATING FAIR CONDITIONS WITH COOL
NIGHTS AND NEAR SEASONABLY WARM DAYS INTO MONDAY. A WEAK COLD FRONT
WILL APPROACH THE REGION FROM THE NORTHWEST TUESDAY INTO WEDNESDAY
AS A LOW PRESSURE SYSTEM LIFTS OUT OF THE GULF OF MEXICO. AS A
RESULT THE REGION MAY SEE SOME SHOWERS ARRIVING.
&&
.UPDATE...
ISSUED AT 1027 PM EDT SAT SEP 29 2012
NOT TOO CONCERNED WITH FROST POTENTIAL TONIGHT. MIXING REMAINS UP
THROUGH THE NIGHT AND IT SEEMS FAIRLY LIKELY THAT SC WILL ENCROACH
MUCH OF THE NE CWA BY MORNING. EVEN IF THE CLOUDS WERE TO BE THIN
OR SCATTERED BELIEVE FROST THREAT IS VERY LOW. COULD BE REMOTE POCKETS
OVER THE INTERIOR NORTH...BUT IT SHOULD BE TOO ISOLATED FOR ANY
HEADLINE. INCREASED MIN TEMPS FOR OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 316 PM EDT SAT SEP 29 2012
THE MAIN CHALLENGE DEALS WITH THE RISK FOR FROST TONIGHT. OVERALL
THE TREND OF TRACKING/FORMING THE SURFACE LOW FURTHER EAST
CONTINUES. LOOKS LIKE IT WILL END UP OVER NEW ENGLAND. HERE IN WRN
LOWER MI...SKIES WILL FEATURE MUCH LESS CLOUD COVER AS A RESULT IT
APPEARS. THIS OPENS UP THE RISK FOR FROST ESPECIALLY WITH HIGH
PRESSURE NOW SHOWN TO DROP SOUTHWARD OUT OF ONTARIO. HOWEVER THE
HRRR RUC AND EVEN THE NAM ARE SHOWING LOW LEVEL MOISTURE AND A
RISK FOR STRATUS TO DEVELOP OVER NORTHEAST LOWER TONIGHT...THEN
DROP SOUTHWEST AND EXPAND INTO SOUTHWEST LOWER MI LATE TONIGHT.
WILL KEEP THE FROST OUT OF THE FORECAST FOR NOW...BUT THIS SHOULD
BE MONITORED CLOSELY AS HEADLINES MAY BE REQUIRED IF THE CLOUDS DO
NOT DEVELOP.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 316 PM EDT SAT SEP 29 2012
TEMPS WILL AVERAGE ABOVE NORMAL TUESDAY BUT SOME CLOUDS FROM LOW
PRESSURE TRACKING NE THROUGH THE OH VALLEY REGION WILL MOVE IN. WE
HAVE INTRODUCED MENTION OF A SLIGHT CHC OF LIGHT RAIN SHOWERS FROM
TUESDAY AFTERNOON THROUGH TUESDAY NIGHT INTO WEDNESDAY IN
ASSOCIATION WITH THAT SYSTEM (MAINLY SE OF GRR).
TEMPS WILL REMAIN ABOVE NORMAL WEDNESDAY THROUGH THURSDAY AFTERNOON
AS FLOW BECOMES SOUTHWESTERLY IN ADVANCE OF A STRONG COLD FRONT.
THAT LOW PRESSURE SYSTEM AND COLD FRONT WILL BRING A CHC OF SHOWERS
THURSDAY NIGHT THROUGH FRIDAY. AN UNSEASONABLY COOL AIRMASS WILL
MOVE IN BEHIND THAT FRONT FRIDAY THROUGH SATURDAY WHEN HIGH TEMPS
WILL ONLY REACH THE 50S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 732 PM EDT SAT SEP 29 2012
SKIES WILL REMAIN MOSTLY CLEAR THROUGH THE EVENING. HOWEVER A
POTENT UPPER LOW MAY GENERATE SOME MVFR CIGS OVER THE ERN CWA
TONIGHT. NE FLOW WILL DEVELOP. WARMER AIR FLOWING OVER LAKE HURON
WILL INTERACT WITH THE COOLER LAND TEMPS SHOULD PRODUCE SOME
STRATOCU. THE QUESTION IS HOW MUCH AND WHERE. STARTED WITH THE ERN
TAFS AFTER 06Z. IT/S POSSIBLE SOME STRATOCU COULD MOVE OVER KGRR
LATE TONIGHT BUT OPTED TO KEEP THAT OUT OF THE TAFS FOR NOW.
&&
.MARINE...
ISSUED AT 316 PM EDT SAT SEP 29 2012
WAVES WILL BE BUILDING AN REACH VALUES CLOSE TO SMALL CRAFT
ADVISORY CRITERIA TONIGHT UP AROUND LITTLE AND BIG SABLE POINTS.
THEN ON SUNDAY AS A NORTHERLY FLOW PERSISTS...WAVES SOUTH OF SOUTH
HAVEN WILL ALSO END UP CLOSE TO CRITERIA. I THOUGHT MOST VALUES
WOULD BE JUST UNDER CRITERIA SO NO HEADLINE AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 316 PM EDT SAT SEP 29 2012
NO HYDRO ISSUES EXPECTED. ANY RAINFALL IS FORECASTED TO BE LIMITED
AND NOT ENOUGH TO CAUSE SIGNIFICANT RISES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...JK
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...LAURENS
AVIATION...93
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
732 PM EDT SAT SEP 29 2012
.SYNOPSIS...
ISSUED AT 316 PM EDT SAT SEP 29 2012
ONE AREA OF LOW PRESSURE WILL DEVELOP OVER NEW ENGLAND TONIGHT AND
SUNDAY. THIS SYSTEM WILL BE TO FAR EAST TO CREATE RAIN HERE IN
WESTERN MICHIGAN. HIGH PRESSURE IN ONTARIO WILL BUILD SOUTH
INTO WESTERN LOWER MICHIGAN CREATING FAIR CONDITIONS WITH COOL
NIGHTS AND NEAR SEASONABLY WARM DAYS INTO MONDAY. A WEAK COLD FRONT
WILL APPROACH THE REGION FROM THE NORTHWEST TUESDAY INTO WEDNESDAY
AS A LOW PRESSURE SYSTEM LIFTS OUT OF THE GULF OF MEXICO. AS A
RESULT THE REGION MAY SEE SOME SHOWERS ARRIVING.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 316 PM EDT SAT SEP 29 2012
THE MAIN CHALLENGE DEALS WITH THE RISK FOR FROST TONIGHT. OVERALL
THE TREND OF TRACKING/FORMING THE SURFACE LOW FURTHER EAST
CONTINUES. LOOKS LIKE IT WILL END UP OVER NEW ENGLAND. HERE IN WRN
LOWER MI...SKIES WILL FEATURE MUCH LESS CLOUD COVER AS A RESULT IT
APPEARS. THIS OPENS UP THE RISK FOR FROST ESPECIALLY WITH HIGH
PRESSURE NOW SHOWN TO DROP SOUTHWARD OUT OF ONTARIO. HOWEVER THE
HRRR RUC AND EVEN THE NAM ARE SHOWING LOW LEVEL MOISTURE AND A
RISK FOR STRATUS TO DEVELOP OVER NORTHEAST LOWER TONIGHT...THEN
DROP SOUTHWEST AND EXPAND INTO SOUTHWEST LOWER MI LATE TONIGHT.
WILL KEEP THE FROST OUT OF THE FORECAST FOR NOW...BUT THIS SHOULD
BE MONITORED CLOSELY AS HEADLINES MAY BE REQUIRED IF THE CLOUDS DO
NOT DEVELOP.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 316 PM EDT SAT SEP 29 2012
TEMPS WILL AVERAGE ABOVE NORMAL TUESDAY BUT SOME CLOUDS FROM LOW
PRESSURE TRACKING NE THROUGH THE OH VALLEY REGION WILL MOVE IN. WE
HAVE INTRODUCED MENTION OF A SLIGHT CHC OF LIGHT RAIN SHOWERS FROM
TUESDAY AFTERNOON THROUGH TUESDAY NIGHT INTO WEDNESDAY IN
ASSOCIATION WITH THAT SYSTEM (MAINLY SE OF GRR).
TEMPS WILL REMAIN ABOVE NORMAL WEDNESDAY THROUGH THURSDAY AFTERNOON
AS FLOW BECOMES SOUTHWESTERLY IN ADVANCE OF A STRONG COLD FRONT.
THAT LOW PRESSURE SYSTEM AND COLD FRONT WILL BRING A CHC OF SHOWERS
THURSDAY NIGHT THROUGH FRIDAY. AN UNSEASONABLY COOL AIRMASS WILL
MOVE IN BEHIND THAT FRONT FRIDAY THROUGH SATURDAY WHEN HIGH TEMPS
WILL ONLY REACH THE 50S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 732 PM EDT SAT SEP 29 2012
SKIES WILL REMAIN MOSTLY CLEAR THROUGH THE EVENING. HOWEVER A
POTENT UPPER LOW MAY GENERATE SOME MVFR CIGS OVER THE ERN CWA
TONIGHT. NE FLOW WILL DEVELOP. WARMER AIR FLOWING OVER LAKE HURON
WILL INTERACT WITH THE COOLER LAND TEMPS SHOULD PRODUCE SOME
STRATOCU. THE QUESTION IS HOW MUCH AND WHERE. STARTED WITH THE ERN
TAFS AFTER 06Z. IT/S POSSIBLE SOME STRATOCU COULD MOVE OVER KGRR
LATE TONIGHT BUT OPTED TO KEEP THAT OUT OF THE TAFS FOR NOW.
&&
.MARINE...
ISSUED AT 316 PM EDT SAT SEP 29 2012
WAVES WILL BE BUILDING AN REACH VALUES CLOSE TO SMALL CRAFT
ADVISORY CRITERIA TONIGHT UP AROUND LITTLE AND BIG SABLE POINTS.
THEN ON SUNDAY AS A NORTHERLY FLOW PERSISTS...WAVES SOUTH OF SOUTH
HAVEN WILL ALSO END UP CLOSE TO CRITERIA. I THOUGHT MOST VALUES
WOULD BE JUST UNDER CRITERIA SO NO HEADLINE AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 316 PM EDT SAT SEP 29 2012
NO HYDRO ISSUES EXPECTED. ANY RAINFALL IS FORECASTED TO BE LIMITED
AND NOT ENOUGH TO CAUSE SIGNIFICANT RISES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...LAURENS
AVIATION...93
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1135 AM CDT FRI SEP 28 2012
.UPDATE...
ISSUED AT 1052 AM CDT FRI SEP 28 2012
HAVE MADE SOME MINOR UPDATES TO PRECIP AND CLOUD COVERAGE TO
ACCOUNT FOR ONGOING TRENDS. SHOWERS OVER THE SRN PART OF THE CWA
ARE DIMINISHING AND DO NOT SEE MUCH MORE THAN SCT COVERAGE THIS
MORNING WITH JUST A FEW SHOWERS THIS AFTERNOON. CLEARING LINE
SHOULD ALSO PUSH SLOWLY SOUTH AS NORTH-NORTHEAST WINDS ADVECT
DRIER AIR INTO THE REGION. GOING HIGHS STILL LOOK ON TRACK.
BRITT
&&
.SHORT TERM...
ISSUED AT 313 AM CDT FRI SEP 28 2012
(TODAY)
THE PRIMARY FCST ISSUE FOR THIS FCST PD IS DETERMINING WHICH PARTS
OF THE CWA ARE MOST LIKELY TO RECEIVE PCPN THROUGH 00Z.
07Z METARS AND MSAS SATURATED EQUIVALENT POTENTIAL TEMPERATURE
FIELDS DEPICTED AN E-W ORIENTED BDRY BISECTING THE CWA. ALOFT...A
SHORTWAVE TROF WAS LOCATED OVER CENTRAL AND WRN MO PER WATER VAPOR
SATELLITE IMAGERY ALONG WITH AN ANTICYCLONICALLY CURVED JET STREAK
AT H25 OVER CENTRAL IL NOTED ON THE LATEST RUC ANALYSIS AND
SUPPORTED BY AREA VWP/PROFILER OBS. LARGE SCALE LIFT AHEAD OF THIS
SHORTWAVE AND RER DYNAMICS ASSOCIATED WITH THE CURVED JET STREAK
WERE SUPPORTING ISO-SCT SHRA ACROSS THE SRN HALF OF THE CWA...MAINLY
ALONG AND S OF THE BDRY. THESE FEATURES ARE EXPECTED TO MOVE E OF
THE CWA BY DAYBREAK WITH PCPN DIMINISHING DUE TO SUBSIDENCE IN THE
WAKE OF THE DEPARTING SHORTWAVE AND DRIER AIR FILTERING IN TO THE
REGION AS A SFC HIGH SINKS SWD. HOWEVER...THE BDRY WILL STILL BE
PRESENT /ALBEIT SLOWLY SINKING SWD/ ACROSS PART OF THE AREA
THROUGH THE AFTN HOURS...AND ANOTHER SHORTWAVE WAS LOCATED
UPSTREAM AT 07Z NEAR THE KS/CO BORDER. DESPITE THE DRIER AIR
FILTERING IN FROM THE NORTH...MODELS DO SHOW SOME 300-250MB
DIVERGENCE ACROSS THE SRN CWA DURING THE DAY AND WHEN COMBINED
WITH THE CO/KS SHORTWAVE THERE MAY BE ENOUGH SUPPORT FOR ISO-SCT
SHRA THIS AFTN INVOF THE BDRY.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 300 AM CDT FRI SEP 28 2012
(TONIGHT - TUESDAY)
ZONAL FLOW ALOFT THAT HAS GIVEN US A PROLONGED PERIOD OF UNSETTLED
WX THIS PAST WEEK WILL TRANSITION TO NW TO N FLOW THAT SHOULD GIVE
US A QUIETER PERIOD FOR A BIT. THIS CHANGE IN FLOW WILL INITIALLY
BE HELPED OUT BY A POLAR VORTEX DIGGING INTO THE GRTLKS REGION THIS
WEEKEND AND LATER BY A TROF THAT DIGS INTO THE CNTRL AND S CNTRL
CONUS EARLY NEXT WEEK...WITH BOTH OF THESE FEATURES EXPECTED TO BE
FAR ENOUGH AWAY TO HAVE LITTLE IMPACT. THE SFC IS EXPECTED TO HAVE
A WEAK RIDGE PREVAILING FOR MUCH OF THIS PERIOD...ALTHOUGH A TROF
WILL TAKE A SWIPE MAINLY AT THE IL SIDE ON SATURDAY NIGHT AND
SUNDAY.
BELOW NORMAL PWATS FOR THIS WEEKEND...A STABLE ATMOSPHERE...AND MOST
IMPORTANTLY...LIFTING MECHANISMS TOO WEAK...SHOULD PRECLUDE ANY PCPN
DEVELOPMENT THIS WEEKEND. NEAR AVERAGE TEMPS FOR LATE SEPTEMBER ARE
EXPECTED...WHICH FAVOR THE MAV MOS NUMBERS WHICH IN MOST CASES ARE
RUNNING A BIT LOWER THAN THE MET MOS.
UP UNTIL THIS POINT THERE IS GOOD AGREEMENT BETWEEN THE MODELS. WE
START TO SEE SOME DISAGREEMENT BEGINNING MONDAY WHERE THE ECMWF
DRAGS A CDFNT THRU WHEREAS THE GFS KEEPS IT WEST OF THE FA WHERE IT
THEN DISSIPATES IT AND RE-ESTABLISHES THE RIDGE. IT APPEARS WITH
RESPECT TO THE BOTTOM LINE...THIS IS A MINOR QUIBBLE AS THE ECMWF
STRUGGLES TO BRING ANY MOISTURE UP IN TIME FOR WHEN IT BRINGS THE
CDFNT THRU...AND IF THIS DOES HAPPEN...SHOULD GO THRU DRY AS A
SYSTEM FURTHER TO THE SE WILL STEAL THE SHOW AND HOG THE SENSIBLE
WX. WILL NEED TO WATCH EXACTLY WHERE THIS SERN CONUS SYSTEM GOES AS
IT COULD EDGE SOME PARTS OF SERN MO AND SRN IL ON MONDAY. TEMPS
COULD BE A BIGGER SOURCE OF ERROR HERE...NAMELY IF THE FRONT
ACTUALLY GOES THRU OR NOT...BUT TEMPS AT OR A BIT ABOVE AVERAGE SEEM
THE BETTER BET.
(WEDNESDAY - THURSDAY)
GFS AND ECMWF CONTINUE THEIR STANDOFF INTO THE MID AND LATER PARTS
OF NEXT WEEK. THE ECMWF FEATURES ZONAL FLOW RETURNING BUT MORE IN
THE FORM OF A PLATEAUED OUT BUILDING RIDGE FROM THE SW WHILE THE GFS
MAINTAINS A TROF OVER THE LOWER MS VALLEY WHICH THEN LIFTS NEWD INTO
THE LOWER OH VALLEY AS IT GETS ABSORBED. EITHER WAY...BOTH ARE
TAKING ANOTHER...STRONGER...CDFNT THRU THE AREA DURING THIS TIME BUT
THE DIFFS IN FLOW ALOFT WILL MAKE FOR A TIMING QUANDARY WITH THE
FRONT BY AS MUCH AS 24HRS. THE GFS TAKES THE CDFNT THRU WEDNESDAY
WHILE THE ECMWF DOESN/T UNTIL THURSDAY. BUT ONCE AGAIN...MOISTURE
RETURN FROM THE GULF IS EFFECTIVELY BLOCKED AND WILL MAKE FOR
LIMITED AMOUNTS TO WORK WITH. VERY QUESTIONABLE WHETHER OR NOT
FRONT CAN GENERATE PCPN HERE BUT IF STRENGTH OF COLD AIR BEHIND IS
SUFFICIENT...IT MAY. ABOVE AVERAGE TEMPS TO CONTINUE AHEAD OF
FRONT.
TES
&&
.AVIATION...
ISSUED AT 1134 AM CDT FRI SEP 28 2012
GENERALLY DRY AND VFR CONDITIONS WILL OCCUR AT THE TAF SITES THROUGH
THE END OF PERIOD. MVFR CIGS OVER THE EASTERN OZARKS WILL GRADUALLY
IMPROVE TO VFR THROUGH THE AFTERNOON. DRY AIR ADVECTION AND MIXING
SHOULD BE ENOUGH TO LIMIT FOG DEVELOPMENT EXCEPT AT KCPS AND KSUS
LATE TONIGHT. EXPECT WINDS TO TURN CALM AT THESE AIRPORTS WHICH
SHOULD ALLOW ENOUGH COOLING TO CAUSE SOME MVFR VSBYS IN BR BETWEEN
09-14Z.
SPECIFICS FOR KSTL...EXPECT DRY AND VFR CONDITIONS THE NEXT 30
HOURS WITH LIGHT NORTH TO NORTHEAST WINDS.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1053 AM CDT FRI SEP 28 2012
.UPDATE...
ISSUED AT 1052 AM CDT FRI SEP 28 2012
HAVE MADE SOME MINOR UPDATES TO PRECIP AND CLOUD COVERAGE TO
ACCOUNT FOR ONGOING TRENDS. SHOWERS OVER THE SRN PART OF THE CWA
ARE DIMINISHING AND DO NOT SEE MUCH MORE THAN SCT COVERAGE THIS
MORNING WITH JUST A FEW SHOWERS THIS AFTERNOON. CLEARING LINE
SHOULD ALSO PUSH SLOWLY SOUTH AS NORTH-NORTHEAST WINDS ADVECT
DRIER AIR INTO THE REGION. GOING HIGHS STILL LOOK ON TRACK.
BRITT
&&
.SHORT TERM...
ISSUED AT 313 AM CDT FRI SEP 28 2012
(TODAY)
THE PRIMARY FCST ISSUE FOR THIS FCST PD IS DETERMINING WHICH PARTS
OF THE CWA ARE MOST LIKELY TO RECEIVE PCPN THROUGH 00Z.
07Z METARS AND MSAS SATURATED EQUIVALENT POTENTIAL TEMPERATURE
FIELDS DEPICTED AN E-W ORIENTED BDRY BISECTING THE CWA. ALOFT...A
SHORTWAVE TROF WAS LOCATED OVER CENTRAL AND WRN MO PER WATER VAPOR
SATELLITE IMAGERY ALONG WITH AN ANTICYCLONICALLY CURVED JET STREAK
AT H25 OVER CENTRAL IL NOTED ON THE LATEST RUC ANALYSIS AND
SUPPORTED BY AREA VWP/PROFILER OBS. LARGE SCALE LIFT AHEAD OF THIS
SHORTWAVE AND RER DYNAMICS ASSOCIATED WITH THE CURVED JET STREAK
WERE SUPPORTING ISO-SCT SHRA ACROSS THE SRN HALF OF THE CWA...MAINLY
ALONG AND S OF THE BDRY. THESE FEATURES ARE EXPECTED TO MOVE E OF
THE CWA BY DAYBREAK WITH PCPN DIMINISHING DUE TO SUBSIDENCE IN THE
WAKE OF THE DEPARTING SHORTWAVE AND DRIER AIR FILTERING IN TO THE
REGION AS A SFC HIGH SINKS SWD. HOWEVER...THE BDRY WILL STILL BE
PRESENT /ALBEIT SLOWLY SINKING SWD/ ACROSS PART OF THE AREA
THROUGH THE AFTN HOURS...AND ANOTHER SHORTWAVE WAS LOCATED
UPSTREAM AT 07Z NEAR THE KS/CO BORDER. DESPITE THE DRIER AIR
FILTERING IN FROM THE NORTH...MODELS DO SHOW SOME 300-250MB
DIVERGENCE ACROSS THE SRN CWA DURING THE DAY AND WHEN COMBINED
WITH THE CO/KS SHORTWAVE THERE MAY BE ENOUGH SUPPORT FOR ISO-SCT
SHRA THIS AFTN INVOF THE BDRY.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 300 AM CDT FRI SEP 28 2012
(TONIGHT - TUESDAY)
ZONAL FLOW ALOFT THAT HAS GIVEN US A PROLONGED PERIOD OF UNSETTLED
WX THIS PAST WEEK WILL TRANSITION TO NW TO N FLOW THAT SHOULD GIVE
US A QUIETER PERIOD FOR A BIT. THIS CHANGE IN FLOW WILL INITIALLY
BE HELPED OUT BY A POLAR VORTEX DIGGING INTO THE GRTLKS REGION THIS
WEEKEND AND LATER BY A TROF THAT DIGS INTO THE CNTRL AND S CNTRL
CONUS EARLY NEXT WEEK...WITH BOTH OF THESE FEATURES EXPECTED TO BE
FAR ENOUGH AWAY TO HAVE LITTLE IMPACT. THE SFC IS EXPECTED TO HAVE
A WEAK RIDGE PREVAILING FOR MUCH OF THIS PERIOD...ALTHOUGH A TROF
WILL TAKE A SWIPE MAINLY AT THE IL SIDE ON SATURDAY NIGHT AND
SUNDAY.
BELOW NORMAL PWATS FOR THIS WEEKEND...A STABLE ATMOSPHERE...AND MOST
IMPORTANTLY...LIFTING MECHANISMS TOO WEAK...SHOULD PRECLUDE ANY PCPN
DEVELOPMENT THIS WEEKEND. NEAR AVERAGE TEMPS FOR LATE SEPTEMBER ARE
EXPECTED...WHICH FAVOR THE MAV MOS NUMBERS WHICH IN MOST CASES ARE
RUNNING A BIT LOWER THAN THE MET MOS.
UP UNTIL THIS POINT THERE IS GOOD AGREEMENT BETWEEN THE MODELS. WE
START TO SEE SOME DISAGREEMENT BEGINNING MONDAY WHERE THE ECMWF
DRAGS A CDFNT THRU WHEREAS THE GFS KEEPS IT WEST OF THE FA WHERE IT
THEN DISSIPATES IT AND RE-ESTABLISHES THE RIDGE. IT APPEARS WITH
RESPECT TO THE BOTTOM LINE...THIS IS A MINOR QUIBBLE AS THE ECMWF
STRUGGLES TO BRING ANY MOISTURE UP IN TIME FOR WHEN IT BRINGS THE
CDFNT THRU...AND IF THIS DOES HAPPEN...SHOULD GO THRU DRY AS A
SYSTEM FURTHER TO THE SE WILL STEAL THE SHOW AND HOG THE SENSIBLE
WX. WILL NEED TO WATCH EXACTLY WHERE THIS SERN CONUS SYSTEM GOES AS
IT COULD EDGE SOME PARTS OF SERN MO AND SRN IL ON MONDAY. TEMPS
COULD BE A BIGGER SOURCE OF ERROR HERE...NAMELY IF THE FRONT
ACTUALLY GOES THRU OR NOT...BUT TEMPS AT OR A BIT ABOVE AVERAGE SEEM
THE BETTER BET.
(WEDNESDAY - THURSDAY)
GFS AND ECMWF CONTINUE THEIR STANDOFF INTO THE MID AND LATER PARTS
OF NEXT WEEK. THE ECMWF FEATURES ZONAL FLOW RETURNING BUT MORE IN
THE FORM OF A PLATEAUED OUT BUILDING RIDGE FROM THE SW WHILE THE GFS
MAINTAINS A TROF OVER THE LOWER MS VALLEY WHICH THEN LIFTS NEWD INTO
THE LOWER OH VALLEY AS IT GETS ABSORBED. EITHER WAY...BOTH ARE
TAKING ANOTHER...STRONGER...CDFNT THRU THE AREA DURING THIS TIME BUT
THE DIFFS IN FLOW ALOFT WILL MAKE FOR A TIMING QUANDARY WITH THE
FRONT BY AS MUCH AS 24HRS. THE GFS TAKES THE CDFNT THRU WEDNESDAY
WHILE THE ECMWF DOESN/T UNTIL THURSDAY. BUT ONCE AGAIN...MOISTURE
RETURN FROM THE GULF IS EFFECTIVELY BLOCKED AND WILL MAKE FOR
LIMITED AMOUNTS TO WORK WITH. VERY QUESTIONABLE WHETHER OR NOT
FRONT CAN GENERATE PCPN HERE BUT IF STRENGTH OF COLD AIR BEHIND IS
SUFFICIENT...IT MAY. ABOVE AVERAGE TEMPS TO CONTINUE AHEAD OF
FRONT.
TES
&&
.AVIATION...
ISSUED AT 615 AM CDT FRI SEP 28 2012
ISO-SCT SHRA INVOF KCOU AND THE STL METRO AREA TAF SITES ARE
EXPECTED TO CONTINUE FOR A FEW MORE HOURS UNTIL A SLOWLY MOVING
FRONT FINALLY SINKS SOUTH OF THE TERMINALS. ISO-SCT PCPN WILL
STILL BE POSSIBLE ALONG AND SOUTH OF THE FRONT TODAY BUT THIS
SHOULD BE LIMITED TO AREAS SOUTH OF THE TAF SITES. MVFR CIGS ARE
EXPECTED TO IMPROVE THIS MORNING DUE TO A COMBINATION OF DIURNAL
MIXING...DRIER AIR NORTH OF THE FRONT...AND THE DEPARTURE OF THE
FRONTAL BDRY.
SPECIFICS FOR KSTL...SCT SHRA INVOF KSTL ARE EXPECTED FOR A FEW
MORE HOURS UNTIL A SLOWLY MOVING FRONT SINKS SOUTH OF THE
TERMINAL. MVFR CIGS ARE EXPECTED TO IMPROVE TO VFR LATER THIS
MORNING ONCE THE BDRY SINKS FARTHER SOUTH OF KSTL.
KANOFSKY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
622 AM CDT FRI SEP 28 2012
.SHORT TERM...
ISSUED AT 313 AM CDT FRI SEP 28 2012
(TODAY)
THE PRIMARY FCST ISSUE FOR THIS FCST PD IS DETERMINING WHICH PARTS
OF THE CWA ARE MOST LIKELY TO RECEIVE PCPN THROUGH 00Z.
07Z METARS AND MSAS SATURATED EQUIVALENT POTENTIAL TEMPERATURE
FIELDS DEPICTED AN E-W ORIENTED BDRY BISECTING THE CWA. ALOFT...A
SHORTWAVE TROF WAS LOCATED OVER CENTRAL AND WRN MO PER WATER VAPOR
SATELLITE IMAGERY ALONG WITH AN ANTICYCLONICALLY CURVED JET STREAK
AT H25 OVER CENTRAL IL NOTED ON THE LATEST RUC ANALYSIS AND
SUPPORTED BY AREA VWP/PROFILER OBS. LARGE SCALE LIFT AHEAD OF THIS
SHORTWAVE AND RER DYNAMICS ASSOCIATED WITH THE CURVED JET STREAK
WERE SUPPORTING ISO-SCT SHRA ACROSS THE SRN HALF OF THE CWA...MAINLY
ALONG AND S OF THE BDRY. THESE FEATURES ARE EXPECTED TO MOVE E OF
THE CWA BY DAYBREAK WITH PCPN DIMINISHING DUE TO SUBSIDENCE IN THE
WAKE OF THE DEPARTING SHORTWAVE AND DRIER AIR FILTERING IN TO THE
REGION AS A SFC HIGH SINKS SWD. HOWEVER...THE BDRY WILL STILL BE
PRESENT /ALBEIT SLOWLY SINKING SWD/ ACROSS PART OF THE AREA
THROUGH THE AFTN HOURS...AND ANOTHER SHORTWAVE WAS LOCATED
UPSTREAM AT 07Z NEAR THE KS/CO BORDER. DESPITE THE DRIER AIR
FILTERING IN FROM THE NORTH...MODELS DO SHOW SOME 300-250MB
DIVERGENCE ACROSS THE SRN CWA DURING THE DAY AND WHEN COMBINED
WITH THE CO/KS SHORTWAVE THERE MAY BE ENOUGH SUPPORT FOR ISO-SCT
SHRA THIS AFTN INVOF THE BDRY.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 300 AM CDT FRI SEP 28 2012
(TONIGHT - TUESDAY)
ZONAL FLOW ALOFT THAT HAS GIVEN US A PROLONGED PERIOD OF UNSETTLED
WX THIS PAST WEEK WILL TRANSITION TO NW TO N FLOW THAT SHOULD GIVE
US A QUIETER PERIOD FOR A BIT. THIS CHANGE IN FLOW WILL INITIALLY
BE HELPED OUT BY A POLAR VORTEX DIGGING INTO THE GRTLKS REGION THIS
WEEKEND AND LATER BY A TROF THAT DIGS INTO THE CNTRL AND S CNTRL
CONUS EARLY NEXT WEEK...WITH BOTH OF THESE FEATURES EXPECTED TO BE
FAR ENOUGH AWAY TO HAVE LITTLE IMPACT. THE SFC IS EXPECTED TO HAVE
A WEAK RIDGE PREVAILING FOR MUCH OF THIS PERIOD...ALTHOUGH A TROF
WILL TAKE A SWIPE MAINLY AT THE IL SIDE ON SATURDAY NIGHT AND
SUNDAY.
BELOW NORMAL PWATS FOR THIS WEEKEND...A STABLE ATMOSPHERE...AND MOST
IMPORTANTLY...LIFTING MECHANISMS TOO WEAK...SHOULD PRECLUDE ANY PCPN
DEVELOPMENT THIS WEEKEND. NEAR AVERAGE TEMPS FOR LATE SEPTEMBER ARE
EXPECTED...WHICH FAVOR THE MAV MOS NUMBERS WHICH IN MOST CASES ARE
RUNNING A BIT LOWER THAN THE MET MOS.
UP UNTIL THIS POINT THERE IS GOOD AGREEMENT BETWEEN THE MODELS. WE
START TO SEE SOME DISAGREEMENT BEGINNING MONDAY WHERE THE ECMWF
DRAGS A CDFNT THRU WHEREAS THE GFS KEEPS IT WEST OF THE FA WHERE IT
THEN DISSIPATES IT AND RE-ESTABLISHES THE RIDGE. IT APPEARS WITH
RESPECT TO THE BOTTOM LINE...THIS IS A MINOR QUIBBLE AS THE ECMWF
STRUGGLES TO BRING ANY MOISTURE UP IN TIME FOR WHEN IT BRINGS THE
CDFNT THRU...AND IF THIS DOES HAPPEN...SHOULD GO THRU DRY AS A
SYSTEM FURTHER TO THE SE WILL STEAL THE SHOW AND HOG THE SENSIBLE
WX. WILL NEED TO WATCH EXACTLY WHERE THIS SERN CONUS SYSTEM GOES AS
IT COULD EDGE SOME PARTS OF SERN MO AND SRN IL ON MONDAY. TEMPS
COULD BE A BIGGER SOURCE OF ERROR HERE...NAMELY IF THE FRONT
ACTUALLY GOES THRU OR NOT...BUT TEMPS AT OR A BIT ABOVE AVERAGE SEEM
THE BETTER BET.
(WEDNESDAY - THURSDAY)
GFS AND ECMWF CONTINUE THEIR STANDOFF INTO THE MID AND LATER PARTS
OF NEXT WEEK. THE ECMWF FEATURES ZONAL FLOW RETURNING BUT MORE IN
THE FORM OF A PLATEAUED OUT BUILDING RIDGE FROM THE SW WHILE THE GFS
MAINTAINS A TROF OVER THE LOWER MS VALLEY WHICH THEN LIFTS NEWD INTO
THE LOWER OH VALLEY AS IT GETS ABSORBED. EITHER WAY...BOTH ARE
TAKING ANOTHER...STRONGER...CDFNT THRU THE AREA DURING THIS TIME BUT
THE DIFFS IN FLOW ALOFT WILL MAKE FOR A TIMING QUANDARY WITH THE
FRONT BY AS MUCH AS 24HRS. THE GFS TAKES THE CDFNT THRU WEDNESDAY
WHILE THE ECMWF DOESN/T UNTIL THURSDAY. BUT ONCE AGAIN...MOISTURE
RETURN FROM THE GULF IS EFFECTIVELY BLOCKED AND WILL MAKE FOR
LIMITED AMOUNTS TO WORK WITH. VERY QUESTIONABLE WHETHER OR NOT
FRONT CAN GENERATE PCPN HERE BUT IF STRENGTH OF COLD AIR BEHIND IS
SUFFICIENT...IT MAY. ABOVE AVERAGE TEMPS TO CONTINUE AHEAD OF
FRONT.
TES
&&
.AVIATION...
ISSUED AT 615 AM CDT FRI SEP 28 2012
ISO-SCT SHRA INVOF KCOU AND THE STL METRO AREA TAF SITES ARE
EXPECTED TO CONTINUE FOR A FEW MORE HOURS UNTIL A SLOWLY MOVING
FRONT FINALLY SINKS SOUTH OF THE TERMINALS. ISO-SCT PCPN WILL
STILL BE POSSIBLE ALONG AND SOUTH OF THE FRONT TODAY BUT THIS
SHOULD BE LIMITED TO AREAS SOUTH OF THE TAF SITES. MVFR CIGS ARE
EXPECTED TO IMPROVE THIS MORNING DUE TO A COMBINATION OF DIURNAL
MIXING...DRIER AIR NORTH OF THE FRONT...AND THE DEPARTURE OF THE
FRONTAL BDRY.
SPECIFICS FOR KSTL...SCT SHRA INVOF KSTL ARE EXPECTED FOR A FEW
MORE HOURS UNTIL A SLOWLY MOVING FRONT SINKS SOUTH OF THE
TERMINAL. MVFR CIGS ARE EXPECTED TO IMPROVE TO VFR LATER THIS
MORNING ONCE THE BDRY SINKS FARTHER SOUTH OF KSTL.
KANOFSKY
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 71 52 75 56 / 10 0 0 0
QUINCY 70 47 76 50 / 5 0 0 0
COLUMBIA 72 48 75 51 / 10 0 0 0
JEFFERSON CITY 72 49 74 51 / 20 5 0 0
SALEM 71 48 72 50 / 10 0 0 5
FARMINGTON 71 50 73 50 / 20 5 0 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
315 AM CDT FRI SEP 28 2012
.SHORT TERM...
ISSUED AT 313 AM CDT FRI SEP 28 2012
(TODAY)
THE PRIMARY FCST ISSUE FOR THIS FCST PD IS DETERMINING WHICH PARTS
OF THE CWA ARE MOST LIKELY TO RECEIVE PCPN THROUGH 00Z.
07Z METARS AND MSAS SATURATED EQUIVALENT POTENTIAL TEMPERATURE
FIELDS DEPICTED AN E-W ORIENTED BDRY BISECTING THE CWA. ALOFT...A
SHORTWAVE TROF WAS LOCATED OVER CENTRAL AND WRN MO PER WATER VAPOR
SATELLITE IMAGERY ALONG WITH AN ANTICYCLONICALLY CURVED JET STREAK
AT H25 OVER CENTRAL IL NOTED ON THE LATEST RUC ANALYSIS AND
SUPPORTED BY AREA VWP/PROFILER OBS. LARGE SCALE LIFT AHEAD OF THIS
SHORTWAVE AND RER DYNAMICS ASSOCIATED WITH THE CURVED JET STREAK
WERE SUPPORTING ISO-SCT SHRA ACROSS THE SRN HALF OF THE CWA...MAINLY
ALONG AND S OF THE BDRY. THESE FEATURES ARE EXPECTED TO MOVE E OF
THE CWA BY DAYBREAK WITH PCPN DIMINISHING DUE TO SUBSIDENCE IN THE
WAKE OF THE DEPARTING SHORTWAVE AND DRIER AIR FILTERING IN TO THE
REGION AS A SFC HIGH SINKS SWD. HOWEVER...THE BDRY WILL STILL BE
PRESENT /ALBEIT SLOWLY SINKING SWD/ ACROSS PART OF THE AREA
THROUGH THE AFTN HOURS...AND ANOTHER SHORTWAVE WAS LOCATED
UPSTREAM AT 07Z NEAR THE KS/CO BORDER. DESPITE THE DRIER AIR
FILTERING IN FROM THE NORTH...MODELS DO SHOW SOME 300-250MB
DIVERGENCE ACROSS THE SRN CWA DURING THE DAY AND WHEN COMBINED
WITH THE CO/KS SHORTWAVE THERE MAY BE ENOUGH SUPPORT FOR ISO-SCT
SHRA THIS AFTN INVOF THE BDRY.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 300 AM CDT FRI SEP 28 2012
(TONIGHT - TUESDAY)
ZONAL FLOW ALOFT THAT HAS GIVEN US A PROLONGED PERIOD OF UNSETTLED
WX THIS PAST WEEK WILL TRANSITION TO NW TO N FLOW THAT SHOULD GIVE
US A QUIETER PERIOD FOR A BIT. THIS CHANGE IN FLOW WILL INITIALLY
BE HELPED OUT BY A POLAR VORTEX DIGGING INTO THE GRTLKS REGION THIS
WEEKEND AND LATER BY A TROF THAT DIGS INTO THE CNTRL AND S CNTRL
CONUS EARLY NEXT WEEK...WITH BOTH OF THESE FEATURES EXPECTED TO BE
FAR ENOUGH AWAY TO HAVE LITTLE IMPACT. THE SFC IS EXPECTED TO HAVE
A WEAK RIDGE PREVAILING FOR MUCH OF THIS PERIOD...ALTHOUGH A TROF
WILL TAKE A SWIPE MAINLY AT THE IL SIDE ON SATURDAY NIGHT AND
SUNDAY.
BELOW NORMAL PWATS FOR THIS WEEKEND...A STABLE ATMOSPHERE...AND MOST
IMPORTANTLY...LIFTING MECHANISMS TOO WEAK...SHOULD PRECLUDE ANY PCPN
DEVELOPMENT THIS WEEKEND. NEAR AVERAGE TEMPS FOR LATE SEPTEMBER ARE
EXPECTED...WHICH FAVOR THE MAV MOS NUMBERS WHICH IN MOST CASES ARE
RUNNING A BIT LOWER THAN THE MET MOS.
UP UNTIL THIS POINT THERE IS GOOD AGREEMENT BETWEEN THE MODELS. WE
START TO SEE SOME DISAGREEMENT BEGINNING MONDAY WHERE THE ECMWF
DRAGS A CDFNT THRU WHEREAS THE GFS KEEPS IT WEST OF THE FA WHERE IT
THEN DISSIPATES IT AND RE-ESTABLISHES THE RIDGE. IT APPEARS WITH
RESPECT TO THE BOTTOM LINE...THIS IS A MINOR QUIBBLE AS THE ECMWF
STRUGGLES TO BRING ANY MOISTURE UP IN TIME FOR WHEN IT BRINGS THE
CDFNT THRU...AND IF THIS DOES HAPPEN...SHOULD GO THRU DRY AS A
SYSTEM FURTHER TO THE SE WILL STEAL THE SHOW AND HOG THE SENSIBLE
WX. WILL NEED TO WATCH EXACTLY WHERE THIS SERN CONUS SYSTEM GOES AS
IT COULD EDGE SOME PARTS OF SERN MO AND SRN IL ON MONDAY. TEMPS
COULD BE A BIGGER SOURCE OF ERROR HERE...NAMELY IF THE FRONT
ACTUALLY GOES THRU OR NOT...BUT TEMPS AT OR A BIT ABOVE AVERAGE SEEM
THE BETTER BET.
(WEDNESDAY - THURSDAY)
GFS AND ECMWF CONTINUE THEIR STANDOFF INTO THE MID AND LATER PARTS
OF NEXT WEEK. THE ECMWF FEATURES ZONAL FLOW RETURNING BUT MORE IN
THE FORM OF A PLATEAUED OUT BUILDING RIDGE FROM THE SW WHILE THE GFS
MAINTAINS A TROF OVER THE LOWER MS VALLEY WHICH THEN LIFTS NEWD INTO
THE LOWER OH VALLEY AS IT GETS ABSORBED. EITHER WAY...BOTH ARE
TAKING ANOTHER...STRONGER...CDFNT THRU THE AREA DURING THIS TIME BUT
THE DIFFS IN FLOW ALOFT WILL MAKE FOR A TIMING QUANDARY WITH THE
FRONT BY AS MUCH AS 24HRS. THE GFS TAKES THE CDFNT THRU WEDNESDAY
WHILE THE ECMWF DOESN/T UNTIL THURSDAY. BUT ONCE AGAIN...MOISTURE
RETURN FROM THE GULF IS EFFECTIVELY BLOCKED AND WILL MAKE FOR
LIMITED AMOUNTS TO WORK WITH. VERY QUESTIONABLE WHETHER OR NOT
FRONT CAN GENERATE PCPN HERE BUT IF STRENGTH OF COLD AIR BEHIND IS
SUFFUCIENT...IT MAY. ABOVE AVERAGE TEMPS TO CONTINUE AHEAD OF
FRONT.
TES
&&
.AVIATION...
ISSUED AT 1152 PM CDT THU SEP 27 2012
HAVE ADDED VCSH AT KCOU AND THE ST. LOUIS METRO TAFS OVER THE NEXT
6 HOURS AS SCATTERED -RA HAS DEVELOPED OVER WRN MO AND WILL MOVE
EAST OVERNIGHT. OTHERWISE...NOT CERTAIN IF CIGS WILL FALL INTO THE
MVFR RANGE THROUGH 14Z...SO HAVE CIGS IN THE BKN035-040 RANGE.
AFTER 15Z...EXPECT DRY AND VFR CONDITIONS THE REST OF THE PERIOD.
SPECIFICS FOR KSTL...HAVE ADDED VCSH FROM 08-11Z TO REFLECT RECENT
DEVELOPMENT OF -RA OVER CNTRL/WRN MO. THERE IS STILL SOME POSSIBILITY
THAT CIGS WILL FALL INTO THE MVFR RANGE OVERNIGHT...BUT WITH PERSISTENT
10-15KT WINDS BETWEEN 1-3K FT NOTED ON THE KLSX AND TSTL WIND
PROFILES THAT WILL IS BRINGING DRY AIR INTO THE REGION...DO NOT
FEEL CONFIDENT ENOUGH AT THIS POINT TO INCLUDE IN A PREDOMINANT
GROUP IN THE TAF. OTHERWISE...EXPECT DRY AND VFR CONDITIONS TO
RETURN TO THE AREA BY MID-MORNING FRIDAY.
BRITT
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 75 52 75 56 / 10 0 0 0
QUINCY 71 47 76 50 / 5 0 0 0
COLUMBIA 73 48 75 51 / 10 0 0 0
JEFFERSON CITY 73 49 74 51 / 20 5 0 0
SALEM 72 48 72 50 / 10 0 0 5
FARMINGTON 72 50 73 50 / 20 5 0 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1152 PM CDT THU SEP 27 2012
.UPDATE...
ISSUED AT 801 PM CDT THU SEP 27 2012
HAVE REDUCED POPS THRU MUCH OF THE NIGHT BASED ON LATEST RADAR
TRENDS AND HRRR DATA. STILL BELIEVE AN INCREASE IN COVERAGE OF
PRECIP WILL OCCUR...BUT EXPECT IT TO BE LATE TONIGHT. S/W
APPROACHING THE REGION SHUD HELP PROVIDE ENUF LIFT THAT ISOD TO
SCT SHRA WILL DEVELOP ACROSS SRN MO. EXPECT PRECIP TO REMAIN ACROSS
SRN HALF OF THE CWA CO-LOCATED WITH BETTER FORCING AND WHAT LITTLE
INSTABILITY REMAINS.
EXPECT CLOUDS TO REMAIN OVER MUCH OF THE CWA THRU MOST OF THE
NIGHT. SOME QUESTION REMAINS ABOUT CLOUDS AS THE S/W MOVES THRU.
IF ENUF CLEARING CAN OCCUR S OF THE FNT...DEVELOPMENT OF FG WILL
BECOME A CONCERN ONCE AGAIN. WILL KEEP MENTION OF FG OUT OF
FORECAST FOR NOW AND ADDRESS IF/WHEN NEEDED.
TILLY
&&
.SHORT TERM...
ISSUED AT 311 PM CDT THU SEP 27 2012
SYNOPSIS
WEAK ZONAL FLOW REMAINS IN CONTROL TODAY. AT THE SFC...A SLOW MOVING
COLD FRONT CONTINUES STEADY PROGRESS SOUTH. THE BNDRY EXTENDS FROM AN
AREA OF LOW PRESSURE IN OK...NE INTO CNTRL MO AND IL AND ON INTO
THE OH VLY. A WAVE ALONG THE FRONT IS PUSHING THRU SW MO AND
SHOULD CONTINUE TO SLIDE EAST ALONG THE FRONT THRU THIS EVENING.
DIURNAL SHRA HAVE ALREADY BEGUN TO FORM ACROSS NW AR AND S CNTRL
MO IN ADVANCE OF THIS FEATURE. OTHER SHRAS HAVE FORMED ACROSS ERN
KS AND WRN MO ON WHAT IS PROBABLY THE ACTUAL FRONT. TO THE
NORTH...A WEAK AREA OF HIGH PRESSURE HAS CLEARED THE SKIES ACROSS
NTRHN MO AND W CNTRL IL.
(TONIGHT THROUGH SUNDAY)
MAIN FOCUS FOR THIS PERIOD WILL BE POPS THRU TOMORROW. THE COLD
FRONT THAT HAS BEEN TRUDGING THRU THE CWA FOR THE PAST COUPLE OF
DAYS HAS FINALLY MADE IT TO I70 TODAY. SHRA/ISLD TSTMS WILL CONTINUE
TO DOT THE STHRN FA THIS EVENING AND THRU THE OVERNIGHT HRS. A VORT
MAX RIDING ENE ALONG THE FRONT WILL ENHANCE THE COVERAGE OF PRECIP
THIS EVENING AND INTO THE EARLY OVERNIGHT HRS. THE NAM AND
SUBSEQUENTLY THE LOCAL WRF APPEAR TO BE TOO STRONG WITH THIS ENERGY.
CONSEQUENTLY...THEY BOTH DEPICT WIDESPREAD PRECIP SOUTH OF I70 THIS
EVENING AND OVERNIGHT. I THINK THIS IS WAY OVERDONE AND THE COVERAGE
WILL BE MORE OF A SCATTERED NATURE. THE FRONT SHOULD PUSH OUT OF THE
AREA FRIDAY MORNING. THERE WILL STILL BE A CHANCE OF SHRAS ON FRIDAY
ACROSS THE ERN OZARKS DUE TO THE PROXIMITY OF THE FRONT.
THE WEAK HIGH WILL CONTINUE TO BUILD INTO THE AREA ON FRIDAY.
ALOFT...A CLOSED LOW OVER JAMES BAY WILL DROP SSW TO LOWER MI BY
SUNDAY MORNING. THIS WILL CAUSE HEIGHTS TO DROP THIS WEEKEND AND
TEMPER THE MODERATION OF THE AIR MASS. 850 TEMPS WILL REMAIN IN THE
UPPER SINGLE DIGITS TO THE LOWER TEENS THRU THE PERIOD...THOUGH
THERE WILL BE A TIGHTER GRADIENT ON SUNDAY AS THE UPPER LOW MAKES
IT/S CLOSEST APPROACH. A WEAK AREA OF LOW PRESSURE IS EXPECTED TO
DVLP THIS WKND IN RESPONSE TO A SW WAVE ROTATING AROUND THE BACK
SIDE OF THE CLOSED LOW. THE MAIN IMPACT OF THIS SYSTEM SHOULD BE A
CHANGE IN THE WIND DIRECTION AS IT PASSES BY TO THE NE
SATURDAY/NIGHT. WINDS SHOULD BECOME WESTERLY FOR A TIME ON SATURDAY
AFTN.
CLOUDS AND PRECIP CHANCES SHOULD KEEP TEMPS DOWN A BIT ON FRIDAY
ACROSS THE ERN OZARKS...OTHERWISE EXPECT CLEAR/MOSTLY CLEAR SKIES
WITH HIGHS IN THE 70S AND LOWS IN THE UPPER 40S/50S. WENT WITH A
BLEND OF GUIDANCE FOR THE MOST PART WITH A FEW EXCEPTIONS. WENT WITH
THE COOLER MAV GUIDANCE FOR HIGHS TOMORROW ACROSS THE ERN OZARKS DUE
TO CLOUDS AND PRECIP POTENTIAL. USED THE WARMER MET GUIDANCE ACROSS
THE ERN OZARKS TONIGHT FOR THE SAME REASON AS THE COOLER GUIDANCE
FOR HIGHS ON FRIDAY. TRIED TO USE THE COOLER MAV MOS FOR LOWS OVER
THE WKND. CLEAR SKIES...LIGHT WINDS AND LOW DPS SHOULD CREATE COOL
OVERNIGHT LOWS.
MILLER
&&
.LONG TERM...
ISSUED AT 311 PM CDT THU SEP 27 2012
(SUNDAY NIGHT THRU THURSDAY NIGHT)
THIS APPEARS TO BE AN EXTENDED PERIOD OF TRANQUIL WEATHER FOR NEXT
WEEK WITH DRY CONDITIONS AND HIGHS IN THE MID 70S TO LOW 80S AND
LOWS IN THE 50S. THE CLOSED LOW OVER THE GRT LKS LIFTS NE ON MONDAY.
IN IT/S WAKE IS A LW TROF THAT TRANSITIONS TO ZONAL FLOW BY MIDWEEK.
THE MODELS ARE INDICATING THE BASE OF THE TROF TRIES TO CLOSE
OFF...BUT THEIR SOLUTIONS VARY ON THE EVOLUTION OF THIS FEATURE.
MODELS INDICATE A SURGE OF MOISTURE FROM THE GULF COAST INTO THE
TN/OH VLYS TOWARDS THE END OF THE PERIOD AS THE REMNANTS OF THE
TROF ARE ABSORBED INTO THE ZONAL FLOW. MOST OF THE PRECIP STAYS TO
THE EAST ATTM...BUT SOMETHING TO BE WATCHED.
MILLER
&&
.AVIATION...
ISSUED AT 1152 PM CDT THU SEP 27 2012
HAVE ADDED VCSH AT KCOU AND THE ST. LOUIS METRO TAFS OVER THE NEXT
6 HOURS AS SCATTERED -RA HAS DEVELOPED OVER WRN MO AND WILL MOVE
EAST OVERNIGHT. OTHERWISE...NOT CERTAIN IF CIGS WILL FALL INTO THE
MVFR RANGE THROUGH 14Z...SO HAVE CIGS IN THE BKN035-040 RANGE.
AFTER 15Z...EXPECT DRY AND VFR CONDITIONS THE REST OF THE PERIOD.
SPECIFICS FOR KSTL...HAVE ADDED VCSH FROM 08-11Z TO REFLECT RECENT
DEVELOPMENT OF -RA OVER CNTRL/WRN MO. THERE IS STILL SOME POSSIBILITY
THAT CIGS WILL FALL INTO THE MVFR RANGE OVERNIGHT...BUT WITH PERSISTENT
10-15KT WINDS BETWEEN 1-3K FT NOTED ON THE KLSX AND TSTL WIND
PROFILES THAT WILL IS BRINGING DRY AIR INTO THE REGION...DO NOT
FEEL CONFIDENT ENOUGH AT THIS POINT TO INCLUDE IN A PREDOMINANT
GROUP IN THE TAF. OTHERWISE...EXPECT DRY AND VFR CONDITIONS TO
RETURN TO THE AREA BY MID-MORNING FRIDAY.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
215 PM EDT FRI SEP 28 2012
.SYNOPSIS...
ISOLATED TO SCATTERED SHOWERS WILL LINGER ACROSS THE REGION THIS
AFTERNOON AS LOW PRESSURE MOVES INTO SOUTHERN NEW ENGLAND. AN
UPPER LEVEL DISTURBANCE WILL BRING UNSETTLED CONDITIONS TO THE
REGION SUNDAY AND MONDAY. NEAR SEASONAL TEMPERATURES ARE EXPECTED
THROUGH THE WEEKEND...WITH TEMPERATURES MODERATING BY MIDWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1130 AM UPDATE...SFC LOW PRES WAS LOCATED OVER NRN NEW JERSEY WITH
ISOLATED TO SCATTERED SHOWERS BACK ACROSS CENTRAL NY AND NRN TIER
OF PA WITH MORE WIDESPREAD ACTIVITY IN PIKE/SULLIVAN COUNTIES.
ACTIVITY WILL ALL BECOME JUST ISOLATED TO SCATTERED DURING THE
NEXT COUPLE OF HOURS AS SFC LOW TRACKS TOWARD LONG ISLAND. WILL
CONTINUE WITH SLIGHT CHC/CHC POPS THROUGH LATE AFTERNOON WITH
HIGHEST POPS NRN/ERN CWA IN AREA OF BETTER MOISTURE/FORCING.
SATELLITE SHOWS OVERCAST SKIES BACK ACROSS LAKE ONTARIO AND EXPECT
AREA TO REMAIN CLOUDY THROUGH MUCH OF THE AFTERNOON WITH SLOW
IMPROVEMENT LATE DAY. BASED ON PERSISTENCE OF LOW CLOUDS LOWERED
MAX TEMPS SEVERAL DEGREES.
PREVIOUS DISC... 4 AM UPDATE... LARGE SCALE UL LOW LOCATED ACRS
LABRADOR AND OVR HUDSON BAY. S/WV IS RIPPING THRU CNTRL
PA...SPURRING SCTD SHOWERS ACRS NY/PA AND NJ AT THIS HOUR.
ELONGATED SFC LOW EXTNDS ACRS THE SPINE OF THE APPS. GREATEST 3HR
SFC PRESSURE FALLS LOCATED OVR ERN PA AND 00Z NAM/GFS TENDS TO
AGREE ON THIS MVMNT THRU 12Z.
HOW FAR NORTH THIS RAIN PROGRESSES ACRS THE CWA IS UP FOR DEBATE AND
MODELS DIFFER ON HOW MUCH OF THE FA WL BE IMPACTED. NAM/GFS ARE
FURTHEST TO THE NORTH WITH THIS PCPN. LATEST HRRR GUIDANCE KEEPS IT
CONFINED FURTHER SOUTH...THEREFORE HV DROPPED POPS ACRS FAR NRN
ZONES NORTH OF A PENN YAN TO SYR TO BOONVILLE LINE THRU 12Z.
AS THE MRNG PROGRESSES AIR MASS WL BEGIN TO SATURATE DOWN WITH LKLY
POPS THRU A GOOD PORTION OF THE AREA THRU THE MRNG HRS. FURTHER TO
THE SOUTHEAST SIGNIFICANT WIND SHEAR WL BE PRESENT TWD DAYBREAK WITH
NAM INDICATING CAPES ARND 200 J/KG AND GFS AT 0 THRU THE DAY TODAY.
THUS HV ADDED IN SLGT CHC FOR THUNDER SOUTH OF THE I-84 CORRIDOR.
AS FOR MAX TEMPS TDA...MOCLDY SKIES WL BE PRESENT THRU THE DAY WITH
H8 TEMPS DROPPING TO BLO 10C. THUS HIGHS WL ONLY REACH TO NR 60F
ACRS UPSTATE NY WITH WYOMING/LACKAWANNA VLYS TOPPING OUT IN THE
MID-UPR 60S.
AS LOPRES WORKS ITS WAY OFF TO THE NE PCPN WL COME TO AN END BY 00Z.
TOTAL QPF AMNTS APPEAR TO BE ARND 1.00 INCH THRU 00Z TONIGHT ACRS
THE WRN CATS AND POCONOS. RMNDR OF THE REGION WL SEE AMNTS ARND 0.50
INCHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
4 AM UPDATE...
RAIN WL COME TO AN END BY SAT MRNG WITH H8 CLD AIR ADVECTION WORKING
INTO THE CWA. MIN TEMPS WL DIP INTO THE MID-40S AND POSSIBLY INTO
THE U30S IN FAVORED LOW VLYS ACRS THE CNTRL SRN TIER WHERE CAA WL BE
STRONGEST. H5 LOW WL DRIFT SOUTH OUT OF HUDSON BAY WITH ALL GUIDANCE
(NAM/GFS/EC) DROPPING IT TO ONTARIO/QUEBEC BORDER BY 12Z SAT.
AS UL LOW APPCHS ON SAT ISOLD SHRAS WL DVLP ACRS THE CWA. THIS UL
LOPRES SYSTEM WL AFFECT CNTRL NY/NEPA THRU THE SHORT TERM. SFC LOW
WL DVLP AND MV INTO THE REGION ALONG WITH PCPN BEGINNING ON SUNDAY.
POPS INCRS FOR SUN AFTN AND INTO THE OVRNGT HRS...WITH LKLY POPS
THRU 12Z MON. TEMPS DRG THE LATTER HALF OF THE WEEKEND WL AVG NR
CLIMO.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS IN DECENT AGREEMENT WITH THE SETUP FOR MONDAY NIGHT. THERE
WILL BE AN EJECTING 500MB CUTOFF LOW THAT SHOULD BE NORTH OF
MAINE. THEY ALSO INDICATE THAT A 500MB LOW PRESSURE TROUGH WILL BE
MOVING EASTWARDS ACROSS THE MISSISSIPPI VALLEY MONDAY NIGHT. AHEAD
OF THIS TROUGH A SFC LOW AND AN AREA OF SHOWERS WILL MOVE
NORTHWARD ALONG THE EASTERN UNITED STATES. SHOWERS WILL BE CLOSE
TO THE SOUTHERN ZONES LATE MONDAY NIGHT. HAVE BUMPED POPS SLIGHTLY
TO HAVE A MENTION OF SHOWERS IN NEPA. THE SOUTHERN TIER, AND CATSKILLS.
FROM THERE, MODEL DIFFER SLIGHTLY. THE ECMWF SHOWS SHOWERS MAY TRY
TO SLIDE OFF TO THE EAST, CLIPPING THE EASTERN ZONES, WHILE THE
GFS HAS THE MAIN BATCH OF SHOWERS COMING RIGHT ACROSS THE ON
TUESDAY. HAVE BUMPED POPS TO CHC FOR THESE AREAS AND SLIGHT CHC
FOR THE REMAINDER OF THE CWA.
BY WEDNESDAY MORNING, THE TROUGH CUTS OFF OVER TENNESSEE, BLOCKED
BY A BUILDING BERMUDA HIGH. SEVERAL WAVES WILL RIDE OVER THE HIGH,
WITH A MOIST RETURN FLOW OVER THE CWA. THIS COULD END UP KEEPING
AT LEAST A SLIGHT CHC OF POPS IN THE FORECAST FOR MOST OF THE
REMAINDER OF THE WEEK.
MODELS BEGIN TO DIFFER GREATLY BY THE END OF NEXT WEEK. THE GFS
HAS A VERY STRONG LOW PRESSURE SYSTEM OVER THE HUDSON BAY BY FRIDAY
06Z, WITH A COLD FRONT APPROACHING THE AREA FROM THE WEST. LOOKING AT
THE ECMWF, THERE IS A SHORT WAVE AT 500MB WITH A SFC LOW DEEPENING
AS IT MOVES ACROSS THE GREAT LAKES EASTWARD, ENDING UP JUST NORTH
OF MAINE BY 06Z FRIDAY, KEEPING THE CWA DRY. GIVEN THESE
DIFFERENCES, HAVE KEPT POPS OUT OF THE FORECAST FOR FRIDAY FOR
NOW, AS THERE IS GREAT UNCERTAINTY ATTM.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A VERY DIFFICULT AVIATION FORECAST AT BEST. AN UPPER LEVEL LOW
PRESSURE SYSTEM IS DROPPING SOUTHWARDS TOWARDS THE FORECAST AREA.
THE LOW, A WEAK SFC LOW, AND PLENTY OF SFC MOISTURE, HAVE KEPT A
VERY LOW DECK OF CLOUDS ALONG WITH SOME LIGHT RAIN SHOWERS AND
DRIZZLE AROUND THIS AFTERNOON. LOOKING AT THE MODELS, THIS LOW
DECK SHOULD EVER SO SLOWLY BEGIN TO LIFT THIS AFTERNOON AND
EVENING. HOWEVER, THIS MAY TAKE UNTIL EARLY TOMORROW MORNING
BEFORE THEY FINALLY RISE ENOUGH TO GO EVEN MVFR. WITH THE LOW
DECK, NOT EXPECTING MUCH IN THE WAY OF FOG, ALTHOUGH SOME SPOTS
MAY STILL SEE FOG EITHER DEVELOP, OR REMAIN IN PLACE FOR NOW. HAVE
PLAYED THE FORECAST CONSERVATIVELY FOR NOW, AS CIGS ARE NOT RISING
MUCH AND RADAR CONTINUES TO SHOW LIGHT SHOWERS DEVELOPING AND
MOVING ACROSS THE AREA.
WINDS LOOK TO BE THE LEAST CONCERN THROUGH THE TAF PERIOD AS THEY
WILL RANGE FROM LIGHT AND VARIABLE TONIGHT AND BECOMING NW A
BETWEEN 5 AND 10 KTS TOMORROW MORNING.
OUTLOOK...
SAT...GENERALLY VFR.
SUN THROUGH WED...VFR WITH MVFR IN SHOWERS POSSIBLE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN/RRM
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...SLI
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1143 AM EDT FRI SEP 28 2012
.SYNOPSIS...
ISOLATED TO SCATTERED SHOWERS WILL LINGER ACROSS THE REGION THIS
AFTERNOON AS LOW PRESSURE MOVES INTO SOUTHERN NEW ENGLAND. AN
UPPER LEVEL DISTURBANCE WILL BRING UNSETTLED CONDITIONS TO THE
REGION SUNDAY AND MONDAY. NEAR SEASONAL TEMPERATURES ARE EXPECTED
THROUGH THE WEEKEND...WITH TEMPERATURES MODERATING BY MIDWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1130 AM UPDATE...SFC LOW PRES WAS LOCATED OVER NRN NEW JERSEY WITH
ISOLATED TO SCATTERED SHOWERS BACK ACROSS CENTRAL NY AND NRN TIER
OF PA WITH MORE WIDESPREAD ACTIVITY IN PIKE/SULLIVAN COUNTIES.
ACTIVITY WILL ALL BECOME JUST ISOLATED TO SCATTERED DURING THE
NEXT COUPLE OF HOURS AS SFC LOW TRACKS TOWARD LONG ISLAND. WILL
CONTINUE WITH SLIGHT CHC/CHC POPS THROUGH LATE AFTERNOON WITH
HIGHEST POPS NRN/ERN CWA IN AREA OF BETTER MOISTURE/FORCING.
SATELLITE SHOWS OVERCAST SKIES BACK ACROSS LAKE ONTARIO AND EXPECT
AREA TO REMAIN CLOUDY THROUGH MUCH OF THE AFTERNOON WITH SLOW
IMPROVEMENT LATE DAY. BASED ON PERSISTENCE OF LOW CLOUDS LOWERED
MAX TEMPS SEVERAL DEGREES.
PREVIOUS DISC... 4 AM UPDATE... LARGE SCALE UL LOW LOCATED ACRS
LABRADOR AND OVR HUDSON BAY. S/WV IS RIPPING THRU CNTRL
PA...SPURRING SCTD SHOWERS ACRS NY/PA AND NJ AT THIS HOUR.
ELONGATED SFC LOW EXTNDS ACRS THE SPINE OF THE APPS. GREATEST 3HR
SFC PRESSURE FALLS LOCATED OVR ERN PA AND 00Z NAM/GFS TENDS TO
AGREE ON THIS MVMNT THRU 12Z.
HOW FAR NORTH THIS RAIN PROGRESSES ACRS THE CWA IS UP FOR DEBATE AND
MODELS DIFFER ON HOW MUCH OF THE FA WL BE IMPACTED. NAM/GFS ARE
FURTHEST TO THE NORTH WITH THIS PCPN. LATEST HRRR GUIDANCE KEEPS IT
CONFINED FURTHER SOUTH...THEREFORE HV DROPPED POPS ACRS FAR NRN
ZONES NORTH OF A PENN YAN TO SYR TO BOONVILLE LINE THRU 12Z.
AS THE MRNG PROGRESSES AIRMASS WL BEGIN TO SATURATE DOWN WITH LKLY
POPS THRU A GOOD PORTION OF THE AREA THRU THE MRNG HRS. FURTHER TO
THE SOUTHEAST SIGNIFICANT WIND SHEAR WL BE PRESENT TWD DAYBREAK WITH
NAM INDICATING CAPES ARND 200 J/KG AND GFS AT 0 THRU THE DAY TODAY.
THUS HV ADDED IN SLGT CHC FOR THUNDER SOUTH OF THE I-84 CORRIDOR.
AS FOR MAX TEMPS TDA...MOCLDY SKIES WL BE PRESENT THRU THE DAY WITH
H8 TEMPS DROPPING TO BLO 10C. THUS HIGHS WL ONLY REACH TO NR 60F
ACRS UPSTATE NY WITH WYOMING/LACKAWANNA VLYS TOPPING OUT IN THE
MID-UPR 60S.
AS LOPRES WORKS ITS WAY OFF TO THE NE PCPN WL COME TO AN END BY 00Z.
TOTAL QPF AMNTS APPEAR TO BE ARND 1.00 INCH THRU 00Z TONIGHT ACRS
THE WRN CATS AND POCONOS. RMNDR OF THE REGION WL SEE AMNTS ARND 0.50
INCHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
4 AM UPDATE...
RAIN WL COME TO AN END BY SAT MRNG WITH H8 CLD AIR ADVECTION WORKING
INTO THE CWA. MIN TEMPS WL DIP INTO THE MID-40S AND POSSIBLY INTO
THE U30S IN FAVORED LOW VLYS ACRS THE CNTRL SRN TIER WHERE CAA WL BE
STRONGEST. H5 LOW WL DRIFT SOUTH OUT OF HUDSON BAY WITH ALL GUIDANCE
(NAM/GFS/EC) DROPPING IT TO ONTARIO/QUEBEC BORDER BY 12Z SAT.
AS UL LOW APPCHS ON SAT ISOLD SHRAS WL DVLP ACRS THE CWA. THIS UL
LOPRES SYSTEM WL AFFECT CNTRL NY/NEPA THRU THE SHORT TERM. SFC LOW
WL DVLP AND MV INTO THE REGION ALONG WITH PCPN BEGINNING ON SUNDAY.
POPS INCRS FOR SUN AFTN AND INTO THE OVRNGT HRS...WITH LKLY POPS
THRU 12Z MON. TEMPS DRG THE LATTER HALF OF THE WEEKEND WL AVG NR
CLIMO.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
320 AM UPDATE...
DRY PERIOD EXPECTED EARLY NEXT WEEK FOLLOWING DEPARTURE OF THIS
WEEKEND/S UPPER LOW. SOME QUESTIONS STILL REMAIN WITH RESPECT TO
POSSIBLE COLD FRONT WHICH IS ADVERTISED BY THE GFS TO PASS WED
AFTERNOON EVENING. THIS SOLUTION HAS VERY LITTLE SUPPORT FROM THE
00Z ECMWF WHICH TAKES A SFC LOW UP THE MID-ATLANTIC COAST DURING
THIS TIME FRAME. THE ECMWF HAS BEEN ADVERTISING THIS IN RECENT
RUNS AND BASED ON THIS...HAVE ELECTED TO INCREASE POPS BOTH TUE
AND TUE NGT. FOLLOWING THIS SYSTEM/S DEPARTURE...DRIER WX LOOKS TO
PREVAIL THROUGH THE DURATION OF THE EXTENDED PERIOD WITH NEAR TO
SLIGHTLY ABOVE NORMAL TEMPS.
PREVIOUS LONG TERM DISCUSSION...
EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL LOW OVER NEW YORK STATE
WHICH LIFTS INTO EASTERN CANADA ON MONDAY. THIS FEATURE WILL
PROVIDE A CONTINUATION OF SHOWERY WEATHER THROUGH SUNDAY NIGHT
WITH GRADUAL IMPROVEMENT ON MONDAY. MONDAY NIGHT THROUGH
WEDNESDAY, UPPER LEVEL FLOW BECOMES MORE ZONAL WITH AREA BETWEEN
TWO SYSTEMS, A WEAK TROF IN EASTERN CANADA AND SFC LOW IN THE MID
ATLANTIC. REGION MAY REMAIN DRY THROUGH THIS PERIOD BUT DUE TO
LACK OF MODEL RUN TO RUN CONTINUITY CONFIDENCE NOT VERY HIGH. ON
THURSDAY, RETURN FLOW ON BACK SIDE OF SFC HIGH PRES OFF THE MID
ATLANTIC COAST MAY BRING THE THREAT FOR SHOWERS ESPECIALLY IN THE
SOUTHERN FORECAST AREA. TEMPS THROUGH PERIOD WILL RUN 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
MAIN BATCH OF RAIN QUICKLY EXITING TOWARDS EASTERN NY THIS
MORNING. MEANWHILE...NEW SCT SHWR ACTIVITY DEVELOPING ACROSS
NORTH-CENTRAL PA AND WESTERN NY AS NEXT UPPER WAVE APPROACHES.
HAVE INCLUDED TEMPO GROUPS AT ALL TERMINALS WITH THE EXCEPTION OF
SYR AND RME FOR LIGHT SHRA ACTIVITY THROUGH 16Z. IFR CONDITIONS
EXPECTED TO PERSIST AT BGM THROUGH THE MORNING WITH MVFR
CONDITIONS LIKELY ELSEWHERE AS INITIAL WAVE EXITS TO THE NORTHEAST.
IFR CIGS ALSO POSSIBLE AT ELM FOR A FEW HRS BEFORE CIGS START TO RISE
LATER THIS MORNING.
MAIN QUESTIONS LATER ONE HINGE UPON WHEN/IF CONDITIONS BEGIN TO
CLEAR LATER ON. FOR NOW WILL SUGGEST BKN-OVC CIGS THROUGH LATE AFTERNOON
WITH POTENTIAL BREAKS THEREAFTER. THE NAM SUGGESTS THE POSSIBILITY
OF A DEVELOPING LAKE RESPONSE LATER TONIGHT WHICH MAY IMPACT SYR.
FOR NOW WILL HIGHLIGHT A BKN MVFR MENTION AFTER 06Z.
OUTLOOK...
SAT...GENERALLY VFR.
SUNDAY THROUGH MONDAY...MVFR SHOWERS POSSIBLE.
TUESDAY...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN/RRM
NEAR TERM...PVN/RRM
SHORT TERM...PVN
LONG TERM...CMG/RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
659 AM EDT FRI SEP 28 2012
.SYNOPSIS...
SHOWERS WILL CONTINUE OFF AND ON ACROSS CENTRAL NEW YORK AND
NORTHEAST PENNSYLVANIA TODAY. AS LOW PRESSURE EXITS THE AREA TO
THE NORTHEAST TONIGHT RAIN WILL COME TO AN END. AN UPPER LEVEL
DISTURBANCE WILL BRING UNSETTLED CONDITIONS TO THE REGION SUNDAY
AND MONDAY. NEAR SEASONAL TEMPERATURES ARE EXPECTED THROUGH THE
WEEKEND...WITH TEMPERATURES MODERATING BY MIDWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4 AM UPDATE...
LARGE SCALE UL LOW LOCATED ACRS LABRADOR AND OVR HUDSON BAY. S/WV
IS RIPPING THRU CNTRL PA...SPURRING SCTD SHOWERS ACRS NY/PA AND NJ
AT THIS HOUR. ELONGATED SFC LOW EXTNDS ACRS THE SPINE OF THE APPS.
GREATEST 3HR SFC PRESSURE FALLS LOCATED OVR ERN PA AND 00Z NAM/GFS
TENDS TO AGREE ON THIS MVMNT THRU 12Z.
HOW FAR NORTH THIS RAIN PROGRESSES ACRS THE CWA IS UP FOR DEBATE AND
MODELS DIFFER ON HOW MUCH OF THE FA WL BE IMPACTED. NAM/GFS ARE
FURTHEST TO THE NORTH WITH THIS PCPN. LATEST HRRR GUIDANCE KEEPS IT
CONFINED FURTHER SOUTH...THEREFORE HV DROPPED POPS ACRS FAR NRN
ZONES NORTH OF A PENN YAN TO SYR TO BOONVILLE LINE THRU 12Z.
AS THE MRNG PROGRESSES AIRMASS WL BEGIN TO SATURATE DOWN WITH LKLY
POPS THRU A GOOD PORTION OF THE AREA THRU THE MRNG HRS. FURTHER TO
THE SOUTHEAST SIGNIFICANT WIND SHEAR WL BE PRESENT TWD DAYBREAK WITH
NAM INDICATING CAPES ARND 200 J/KG AND GFS AT 0 THRU THE DAY TODAY.
THUS HV ADDED IN SLGT CHC FOR THUNDER SOUTH OF THE I-84 CORRIDOR.
AS FOR MAX TEMPS TDA...MOCLDY SKIES WL BE PRESENT THRU THE DAY WITH
H8 TEMPS DROPPING TO BLO 10C. THUS HIGHS WL ONLY REACH TO NR 60F
ACRS UPSTATE NY WITH WYOMING/LACKAWANNA VLYS TOPPING OUT IN THE
MID-UPR 60S.
AS LOPRES WORKS ITS WAY OFF TO THE NE PCPN WL COME TO AN END BY 00Z.
TOTAL QPF AMNTS APPEAR TO BE ARND 1.00 INCH THRU 00Z TONIGHT ACRS
THE WRN CATS AND POCONOS. RMNDR OF THE REGION WL SEE AMNTS ARND 0.50
INCHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
4 AM UPDATE...
RAIN WL COME TO AN END BY SAT MRNG WITH H8 CLD AIR ADVECTION WORKING
INTO THE CWA. MIN TEMPS WL DIP INTO THE MID-40S AND POSSIBLY INTO
THE U30S IN FAVORED LOW VLYS ACRS THE CNTRL SRN TIER WHERE CAA WL BE
STRONGEST. H5 LOW WL DRIFT SOUTH OUT OF HUDSON BAY WITH ALL GUIDANCE
(NAM/GFS/EC) DROPPING IT TO ONTARIO/QUEBEC BORDER BY 12Z SAT.
AS UL LOW APPCHS ON SAT ISOLD SHRAS WL DVLP ACRS THE CWA. THIS UL
LOPRES SYSTEM WL AFFECT CNTRL NY/NEPA THRU THE SHORT TERM. SFC LOW
WL DVLP AND MV INTO THE REGION ALONG WITH PCPN BEGINNING ON SUNDAY.
POPS INCRS FOR SUN AFTN AND INTO THE OVRNGT HRS...WITH LKLY POPS
THRU 12Z MON. TEMPS DRG THE LATTER HALF OF THE WEEKEND WL AVG NR
CLIMO.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
320 AM UPDATE...
DRY PERIOD EXPECTED EARLY NEXT WEEK FOLLOWING DEPARTURE OF THIS
WEEKEND/S UPPER LOW. SOME QUESTIONS STILL REMAIN WITH RESPECT TO
POSSIBLE COLD FRONT WHICH IS ADVERTISED BY THE GFS TO PASS WED
AFTERNOON EVENING. THIS SOLUTION HAS VERY LITTLE SUPPORT FROM THE
00Z ECMWF WHICH TAKES A SFC LOW UP THE MID-ATLANTIC COAST DURING
THIS TIME FRAME. THE ECMWF HAS BEEN ADVERTISING THIS IN RECENT
RUNS AND BASED ON THIS...HAVE ELECTED TO INCREASE POPS BOTH TUE
AND TUE NGT. FOLLOWING THIS SYSTEM/S DEPARTURE...DRIER WX LOOKS TO
PREVAIL THROUGH THE DURATION OF THE EXTENDED PERIOD WITH NEAR TO
SLIGHTLY ABOVE NORMAL TEMPS.
PREVIOUS LONG TERM DISCUSSION...
EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL LOW OVER NEW YORK STATE
WHICH LIFTS INTO EASTERN CANADA ON MONDAY. THIS FEATURE WILL
PROVIDE A CONTINUATION OF SHOWERY WEATHER THROUGH SUNDAY NIGHT
WITH GRADUAL IMPROVEMENT ON MONDAY. MONDAY NIGHT THROUGH
WEDNESDAY, UPPER LEVEL FLOW BECOMES MORE ZONAL WITH AREA BETWEEN
TWO SYSTEMS, A WEAK TROF IN EASTERN CANADA AND SFC LOW IN THE MID
ATLANTIC. REGION MAY REMAIN DRY THROUGH THIS PERIOD BUT DUE TO
LACK OF MODEL RUN TO RUN CONTINUITY CONFIDENCE NOT VERY HIGH. ON
THURSDAY, RETURN FLOW ON BACK SIDE OF SFC HIGH PRES OFF THE MID
ATLANTIC COAST MAY BRING THE THREAT FOR SHOWERS ESPECIALLY IN THE
SOUTHERN FORECAST AREA. TEMPS THROUGH PERIOD WILL RUN 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
MAIN BATCH OF RAIN QUICKLY EXITING TOWARDS EASTERN NY THIS
MORNING. MEANWHILE...NEW SCT SHWR ACTIVITY DEVELOPING ACROSS
NORTH-CENTRAL PA AND WESTERN NY AS NEXT UPPER WAVE APPROACHES.
HAVE INCLUDED TEMPO GROUPS AT ALL TERMINALS WITH THE EXCEPTION OF
SYR AND RME FOR LIGHT SHRA ACTIVITY THROUGH 16Z. IFR CONDITIONS
EXPECTED TO PERSIST AT BGM THROUGH THE MORNING WITH MVFR
CONDITIONS LIKELY ELSEWHERE AS INITIAL WAVE EXITS TO THE NORTHEAST.
IFR CIGS ALSO POSSIBLE AT ELM FOR A FEW HRS BEFORE CIGS START TO RISE
LATER THIS MORNING.
MAIN QUESTIONS LATER ONE HINGE UPON WHEN/IF CONDITIONS BEGIN TO
CLEAR LATER ON. FOR NOW WILL SUGGEST BKN-OVC CIGS THROUGH LATE AFTERNOON
WITH POTENTIAL BREAKS THEREAFTER. THE NAM SUGGESTS THE POSSIBILITY
OF A DEVELOPING LAKE RESPONSE LATER TONIGHT WHICH MAY IMPACT SYR.
FOR NOW WILL HIGHLIGHT A BKN MVFR MENTION AFTER 06Z.
OUTLOOK...
SAT...GENERALLY VFR.
SUNDAY THROUGH MONDAY...MVFR SHOWERS POSSIBLE.
TUESDAY...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...PVN
LONG TERM...CMG/RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
358 AM EDT FRI SEP 28 2012
.SYNOPSIS...
SHOWERS WILL CONTINUE OFF AND ON ACROSS CENTRAL NEW YORK AND
NORTHEAST PENNSYLVANIA TODAY. AS LOW PRESSURE EXITS THE AREA TO
THE NORTHEAST TONIGHT RAIN WILL COME TO AN END. AN UPPER LEVEL
DISTURBANCE WILL BRING UNSETTLED CONDITIONS TO THE REGION SUNDAY
AND MONDAY. NEAR SEASONAL TEMPERATURES ARE EXPECTED THROUGH THE
WEEKEND...WITH TEMPERATURES MODERATING BY MIDWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4 AM UPDATE...
LARGE SCALE UL LOW LOCATED ACRS LABRADOR AND OVR HUDSON BAY. S/WV
IS RIPPING THRU CNTRL PA...SPURRING SCTD SHOWERS ACRS NY/PA AND NJ
AT THIS HOUR. ELONGATED SFC LOW EXTNDS ACRS THE SPINE OF THE APPS.
GREATEST 3HR SFC PRESSURE FALLS LOCATED OVR ERN PA AND 00Z NAM/GFS
TENDS TO AGREE ON THIS MVMNT THRU 12Z.
HOW FAR NORTH THIS RAIN PROGRESSES ACRS THE CWA IS UP FOR DEBATE AND
MODELS DIFFER ON HOW MUCH OF THE FA WL BE IMPACTED. NAM/GFS ARE
FURTHEST TO THE NORTH WITH THIS PCPN. LATEST HRRR GUIDANCE KEEPS IT
CONFINED FURTHER SOUTH...THEREFORE HV DROPPED POPS ACRS FAR NRN
ZONES NORTH OF A PENN YAN TO SYR TO BOONVILLE LINE THRU 12Z.
AS THE MRNG PROGRESSES AIRMASS WL BEGIN TO SATURATE DOWN WITH LKLY
POPS THRU A GOOD PORTION OF THE AREA THRU THE MRNG HRS. FURTHER TO
THE SOUTHEAST SIGNIFICANT WIND SHEAR WL BE PRESENT TWD DAYBREAK WITH
NAM INDICATING CAPES ARND 200 J/KG AND GFS AT 0 THRU THE DAY TODAY.
THUS HV ADDED IN SLGT CHC FOR THUNDER SOUTH OF THE I-84 CORRIDOR.
AS FOR MAX TEMPS TDA...MOCLDY SKIES WL BE PRESENT THRU THE DAY WITH
H8 TEMPS DROPPING TO BLO 10C. THUS HIGHS WL ONLY REACH TO NR 60F
ACRS UPSTATE NY WITH WYOMING/LACKAWANNA VLYS TOPPING OUT IN THE
MID-UPR 60S.
AS LOPRES WORKS ITS WAY OFF TO THE NE PCPN WL COME TO AN END BY 00Z.
TOTAL QPF AMNTS APPEAR TO BE ARND 1.00 INCH THRU 00Z TONIGHT ACRS
THE WRN CATS AND POCONOS. RMNDR OF THE REGION WL SEE AMNTS ARND 0.50
INCHES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
4 AM UPDATE...
RAIN WL COME TO AN END BY SAT MRNG WITH H8 CLD AIR ADVECTION WORKING
INTO THE CWA. MIN TEMPS WL DIP INTO THE MID-40S AND POSSIBLY INTO
THE U30S IN FAVORED LOW VLYS ACRS THE CNTRL SRN TIER WHERE CAA WL BE
STRONGEST. H5 LOW WL DRIFT SOUTH OUT OF HUDSON BAY WITH ALL GUIDANCE
(NAM/GFS/EC) DROPPING IT TO ONTARIO/QUEBEC BORDER BY 12Z SAT.
AS UL LOW APPCHS ON SAT ISOLD SHRAS WL DVLP ACRS THE CWA. THIS UL
LOPRES SYSTEM WL AFFECT CNTRL NY/NEPA THRU THE SHORT TERM. SFC LOW
WL DVLP AND MV INTO THE REGION ALONG WITH PCPN BEGINNING ON SUNDAY.
POPS INCRS FOR SUN AFTN AND INTO THE OVRNGT HRS...WITH LKLY POPS
THRU 12Z MON. TEMPS DRG THE LATTER HALF OF THE WEEKEND WL AVG NR
CLIMO.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
320 AM UPDATE...
DRY PERIOD EXPECTED EARLY NEXT WEEK FOLLOWING DEPARTURE OF THIS
WEEKEND/S UPPER LOW. SOME QUESTIONS STILL REMAIN WITH RESPECT TO
POSSIBLE COLD FRONT WHICH IS ADVERTISED BY THE GFS TO PASS WED
AFTERNOON EVENING. THIS SOLUTION HAS VERY LITTLE SUPPORT FROM THE
00Z ECMWF WHICH TAKES A SFC LOW UP THE MID-ATLANTIC COAST DURING
THIS TIME FRAME. THE ECMWF HAS BEEN ADVERTISING THIS IN RECENT
RUNS AND BASED ON THIS...HAVE ELECTED TO INCREASE POPS BOTH TUE
AND TUE NGT. FOLLOWING THIS SYSTEM/S DEPARTURE...DRIER WX LOOKS TO
PREVAIL THROUGH THE DURATION OF THE EXTENDED PERIOD WITH NEAR TO
SLIGHTLY ABOVE NORMAL TEMPS.
PREVIOUS LONG TERM DISCUSSION...
EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL LOW OVER NEW YORK STATE
WHICH LIFTS INTO EASTERN CANADA ON MONDAY. THIS FEATURE WILL
PROVIDE A CONTINUATION OF SHOWERY WEATHER THROUGH SUNDAY NIGHT
WITH GRADUAL IMPROVEMENT ON MONDAY. MONDAY NIGHT THROUGH
WEDNESDAY, UPPER LEVEL FLOW BECOMES MORE ZONAL WITH AREA BETWEEN
TWO SYSTEMS, A WEAK TROF IN EASTERN CANADA AND SFC LOW IN THE MID
ATLANTIC. REGION MAY REMAIN DRY THROUGH THIS PERIOD BUT DUE TO
LACK OF MODEL RUN TO RUN CONTINUITY CONFIDENCE NOT VERY HIGH. ON
THURSDAY, RETURN FLOW ON BACK SIDE OF SFC HIGH PRES OFF THE MID
ATLANTIC COAST MAY BRING THE THREAT FOR SHOWERS ESPECIALLY IN THE
SOUTHERN FORECAST AREA. TEMPS THROUGH PERIOD WILL RUN 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
LATEST RADAR TRENDS SHOWING MAIN RAIN SHIELD PUSHING THROUGH THE
TWIN TIERS AND REMAINDER OF NE PA THIS HR. SO FAR CONDITIONS HAVE
LARGELY REMAINED VFR...HOWEVER EXPECT CATEGORICAL DETERIORATION
WITHIN THE NEXT FEW HRS FOR ALL SITES EXCEPT SYR AND RME WHERE
RAIN SHIELD SHOULD REMAIN SOUTH. FOR NOW EXPECT IFR CONDITIONS ARE
BGM AFTER 08Z...WITH ELM/ITH/AVP LARGELY EXPECTED TO REMAIN MVFR.
CLOUDS WILL BE SLOW TO GO WITH MVFR CONDITIONS EXPECTED THROUGH
EARLY TO MID AFTERNOON. BEYOND THIS...DRIER AIR WILL MOVE INTO THE
REGION WHICH SHOULD RESULT IN GRADUAL IMPROVEMENT TOWARDS 00Z.
LIGHT EASTERLY WINDS EARLY ON WILL GRADUALLY SHIFT TOWARDS THE
NORTHWEST (5-10 KTS) BY AFTERNOON AS LOW EXITS TO THE EAST.
OUTLOOK...
SAT...GENERALLY VFR.
SUNDAY THROUGH MONDAY...MVFR SHOWERS POSSIBLE.
TUESDAY...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...PVN
NEAR TERM...PVN
SHORT TERM...PVN
LONG TERM...CMG/RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
322 AM EDT FRI SEP 28 2012
.SYNOPSIS...
CONDITIONS WILL DETERIORATE QUICKLY TONIGHT, AS LOW PRESSURE
TRACKS TOWARDS OUR AREA FROM OHIO. RAIN WILL MOSTLY FALL LATE
TONIGHT AND FRIDAY MORNING BEFORE ENDING FRIDAY AFTERNOON.
SATURDAY, WEAK HIGH PRESSURE WILL BRING MAINLY DRY WEATHER.
UNSETTLED CONDITIONS WILL RETURN SUNDAY INTO MONDAY AS AN UPPER
LEVEL DISTURBANCE MOVES THROUGH THE NORTHEAST UNITED STATES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12 AM UPDATE..
QUICK UPDATE TO RMV POPS ACRS THE FAR NORTH FOR TONIGHT. RADAR
POPUP SKEW-T ACRS THE NRN ZONES INDICATE DRY LAYER FM SFC-H7. 00Z
RAOBS INDICATE SAT/D AIRMASS TO THE SOUTH AND DRY AIR TO THE
NORTH. THIS APPEARS TO SUPPORT BUFKIT SNDGS AND 00Z NAM GUIDANCE
INDICATES A SLOW SATURATION OF ATMOS AFT 12Z ACRS THE NORTH...THUS
HV TRIMMED POPS BACK THRU 12Z. PREVIOUS AFD BELOW.
9 PM UPDATE...
RAIN NOW MOVING INTO NEPA. FROM RADAR RETURNS BIGGEST IMPACT WILL
REMAIN HERE FOR THE NEXT FEW HOURS...WITH VERY LIGHT SHOWERS JUST
GETTING INTO THE SOUTHERN TIER OF NY...WITH DRY WEATHER NORTH OF
HERE.
7 PM UPDATE...
AN AREA OF LIGHT RAIN ACROSS CENTRAL PA CONTINUES TO SLOWLY LIFT
NORTHEAST BUT IS HAVING SOME TROUBLE AT THE MOMENT AS HIGH
PRESSURE OVER QUEBEC IS SLOW TO LOSE ITS GRIP ON OUR AREA. THIS IS
MOST EVIDENT WITH A QUICK GLANCE AT SURFACE DEW POINTS...SHOWING
LOW TO MID 40S ACROSS CNY...BUT CREEPING INTO THE MID 50S DOWN IN
NEPA. AS OUR ATMOSPHERE CONTINUES TO MOISTEN UP AND WE BEGIN TO
SEE A MID DECK AROUND 5KFT DEVELOP...SHOWERS ARE LIKELY IN NEPA
BETWEEN 02Z AND 04Z...OR JUST A TAD SLOWER THAN THE PREVIOUS
FORECAST. THE 18Z NAM...ALONG WITH THE HIGHER RESOLUTION MODELS OF
THE ARW/NMM AND HRRR CONTINUE TO SUGGEST THAT IT WILL BE HARD FOR
PRECIP TO MAKE IT MUCH FARTHER NORTH THAN THE NY/PA LINE THROUGH
06Z. IN FACT...THE BIGGEST ADJUSTMENT WITH THIS PACKAGE WAS
DELAYING THE RAIN MUCH LONGER ACROSS CNY...AND KEEPING THESE AREAS
DRY UNTIL CLOSER TO DAYBREAK IF NOT MID FRIDAY MORNING. THE NEW
QPF GUIDANCE IS IN FROM HPC AND AGREES WITH MORE EMPHASIS FARTHER
SOUTH AND EAST...AND DELAYED TIMING FARTHER NORTH AND WEST. THE
PREVIOUS AFD IS BELOW...
3 PM UPDATE...
WEAK LOW PRESSURE IN OHIO WILL TRACK ENE INTO SE NY FRI AFTN.
AHEAD OF THIS SFC LOW IS A 40 KT LOW LEVEL JET FEEDING MOISTURE
INTO THE LIFT AHEAD OF IT. THIS WILL INCREASE AS IT NEARS THE
COAST AND TAPS THE ATLANTIC. PWATS RISE TO AROUND 1.5 INCHES. SFC
PRESSURE WILL ALSO DECREASE SLOWLY AS IT APPROACHES. LIFT WILL
ALSO INCREASE AS THE NORTHERN STREAM MOVES SOUTH PUTTING THE AREA
IN THE RIGHT REAR WHILE THE SOUTHERN STREAM MOVES IN FOR THE FRONT
LEFT QUAD. MOST OF THE RAIN WILL BE AHEAD OF THE SFC LOW STARTING
IN NE PA THIS EVENING THEN INTO THE REST OF THE AREA LATE TONIGHT.
THE RAIN WILL TAPER OFF FROM SW TO NE FRIDAY AFTERNOON. RAINFALL
AMOUNTS WILL RANGE FROM A THIRD OF AN INCH IN THE CENTRAL SOUTHERN
TIER AND FINGER LAKES OF NY TO JUST OVER AN INCH IN NE PA AND THE
CATSKILLS. SOME LOCATIONS COULD APPROACH TWO INCHES DUE TO UPSLOPE
FLOW. THIS AMOUNT OF RAIN WILL NOT CAUSE ANY FLASH FLOODING.
RIVERS WILL RISE SOME BUT REMAIN WELL BELOW BANK FULL.
FOR TEMPERATURES WENT ON THE WARM SIDE TONIGHT WITH CLOUDS COMING
IN ATTM. FRIDAY GUIDANCE SIMILAR AND WENT CLOSE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
3 PM UPDATE...
AFTER A QUIET MAINLY DRY PERIOD FRIDAY NIGHT TO SATURDAY NIGHT
SHOWERS WILL RETURN STARTING SUNDAY. FRIDAY NIGHT PARTIAL
CLEARING WITH WEAK HIGH PRESSURE. THE SFC LOW WILL CONTINUE
EAST TO THE GULF OF MAINE. THE CWA WILL BE WAITING FOR THE NEXT
SYSTEM WITH A DEEP UPPER LEVEL TROF DROPPING SE INTO NY. MODELS
SLOWER WITH THIS FEATURE SO SATURDAY IS LOOKING BETTER.
TEMPERATURES NEAR NORMAL BUT MOSTLY CLOUDY STILL. SOME LOW LEVEL
MOISTURE OFF OF THE LAKES WILL BRING SOME CUMULUS. 850MB TEMPS
FALL BACK TO PLUS 3C.
MODELS DIFFER ON THE TIMING OF THE UPPER LEVEL TROF. MOST OF THE
DIFFERENCE IS IN THE EXIT DURING THE EARLY PART OF THE LONG TERM.
MOST MODELS HAVE THE LOW OVER NY AND PA LATE SUNDAY. THE COLD AIR
ALOFT COMBINED WITH EARLY DAY SUNSHINE AND HEATING WILL MEAN
SHOWERS WILL INCREASE IN COVERAGE AND INTENSITY. HIGH TEMPS NEAR
NORMAL MIDDAY BEFORE FALLING IN THE SHOWERS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
320 AM UPDATE...
DRY PERIOD EXPECTED EARLY NEXT WEEK FOLLOWING DEPARTURE OF THIS
WEEKEND/S UPPER LOW. SOME QUESTIONS STILL REMAIN WITH RESPECT TO
POSSIBLE COLD FRONT WHICH IS ADVERTISED BY THE GFS TO PASS WED
AFTERNOON EVENING. THIS SOLUTION HAS VERY LITTLE SUPPORT FROM THE
00Z ECMWF WHICH TAKES A SFC LOW UP THE MID-ATLANTIC COAST DURING
THIS TIME FRAME. THE ECMWF HAS BEEN ADVERTISING THIS IN RECENT
RUNS AND BASED ON THIS...HAVE ELECTED TO INCREASE POPS BOTH TUE
AND TUE NGT. FOLLOWING THIS SYSTEM/S DEPARTURE...DRIER WX LOOKS TO
PREVAIL THROUGH THE DURATION OF THE EXTENDED PERIOD WITH NEAR TO
SLIGHTLY ABOVE NORMAL TEMPS.
PREVIOUS LONG TERM DISCUSSION...
EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL LOW OVER NEW YORK STATE
WHICH LIFTS INTO EASTERN CANADA ON MONDAY. THIS FEATURE WILL
PROVIDE A CONTINUATION OF SHOWERY WEATHER THROUGH SUNDAY NIGHT
WITH GRADUAL IMPROVEMENT ON MONDAY. MONDAY NIGHT THROUGH
WEDNESDAY, UPPER LEVEL FLOW BECOMES MORE ZONAL WITH AREA BETWEEN
TWO SYSTEMS, A WEAK TROF IN EASTERN CANADA AND SFC LOW IN THE MID
ATLANTIC. REGION MAY REMAIN DRY THROUGH THIS PERIOD BUT DUE TO
LACK OF MODEL RUN TO RUN CONTINUITY CONFIDENCE NOT VERY HIGH. ON
THURSDAY, RETURN FLOW ON BACK SIDE OF SFC HIGH PRES OFF THE MID
ATLANTIC COAST MAY BRING THE THREAT FOR SHOWERS ESPECIALLY IN THE
SOUTHERN FORECAST AREA. TEMPS THROUGH PERIOD WILL RUN 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
LATEST RADAR TRENDS SHOWING MAIN RAIN SHIELD PUSHING THROUGH THE
TWIN TIERS AND REMAINDER OF NE PA THIS HR. SO FAR CONDITIONS HAVE
LARGELY REMAINED VFR...HOWEVER EXPECT CATEGORICAL DETERIORATION
WITHIN THE NEXT FEW HRS FOR ALL SITES EXCEPT SYR AND RME WHERE
RAIN SHIELD SHOULD REMAIN SOUTH. FOR NOW EXPECT IFR CONDITIONS ARE
BGM AFTER 08Z...WITH ELM/ITH/AVP LARGELY EXPECTED TO REMAIN MVFR.
CLOUDS WILL BE SLOW TO GO WITH MVFR CONDITIONS EXPECTED THROUGH
EARLY TO MID AFTERNOON. BEYOND THIS...DRIER AIR WILL MOVE INTO THE
REGION WHICH SHOULD RESULT IN GRADUAL IMPROVEMENT TOWARDS 00Z.
LIGHT EASTERLY WINDS EARLY ON WILL GRADUALLY SHIFT TOWARDS THE
NORTHWEST (5-10 KTS) BY AFTERNOON AS LOW EXITS TO THE EAST.
OUTLOOK...
SAT...GENERALLY VFR.
SUNDAY THROUGH MONDAY...MVFR SHOWERS POSSIBLE.
TUESDAY...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...HEDEN/PVN
SHORT TERM...TAC
LONG TERM...CMG/RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
151 AM EDT FRI SEP 28 2012
.SYNOPSIS...
CONDITIONS WILL DETERIORATE QUICKLY TONIGHT, AS LOW PRESSURE
TRACKS TOWARDS OUR AREA FROM OHIO. RAIN WILL MOSTLY FALL LATE
TONIGHT AND FRIDAY MORNING BEFORE ENDING FRIDAY AFTERNOON.
SATURDAY, WEAK HIGH PRESSURE WILL BRING MAINLY DRY WEATHER.
UNSETTLED CONDITIONS WILL RETURN SUNDAY INTO MONDAY AS AN UPPER
LEVEL DISTURBANCE MOVES THROUGH THE NORTHEAST UNITED STATES.
&&
.NEAR TERM /THROUGH TODAY/...
12 AM UPDATE..
QUICK UPDATE TO RMV POPS ACRS THE FAR NORTH FOR TONIGHT. RADAR
POPUP SKEW-T ACRS THE NRN ZONES INDICATE DRY LAYER FM SFC-H7. 00Z
RAOBS INDICATE SAT/D AIRMASS TO THE SOUTH AND DRY AIR TO THE
NORTH. THIS APPEARS TO SUPPORT BUFKIT SNDGS AND 00Z NAM GUIDANCE
INDICATES A SLOW SATURATION OF ATMOS AFT 12Z ACRS THE NORTH...THUS
HV TRIMMED POPS BACK THRU 12Z. PREVIOUS AFD BELOW.
9 PM UPDATE...
RAIN NOW MOVING INTO NEPA. FROM RADAR RETURNS BIGGEST IMPACT WILL
REMAIN HERE FOR THE NEXT FEW HOURS...WITH VERY LIGHT SHOWERS JUST
GETTING INTO THE SOUTHERN TIER OF NY...WITH DRY WEATHER NORTH OF
HERE.
7 PM UPDATE...
AN AREA OF LIGHT RAIN ACROSS CENTRAL PA CONTINUES TO SLOWLY LIFT
NORTHEAST BUT IS HAVING SOME TROUBLE AT THE MOMENT AS HIGH
PRESSURE OVER QUEBEC IS SLOW TO LOSE ITS GRIP ON OUR AREA. THIS IS
MOST EVIDENT WITH A QUICK GLANCE AT SURFACE DEW POINTS...SHOWING
LOW TO MID 40S ACROSS CNY...BUT CREEPING INTO THE MID 50S DOWN IN
NEPA. AS OUR ATMOSPHERE CONTINUES TO MOISTEN UP AND WE BEGIN TO
SEE A MID DECK AROUND 5KFT DEVELOP...SHOWERS ARE LIKELY IN NEPA
BETWEEN 02Z AND 04Z...OR JUST A TAD SLOWER THAN THE PREVIOUS
FORECAST. THE 18Z NAM...ALONG WITH THE HIGHER RESOLUTION MODELS OF
THE ARW/NMM AND HRRR CONTINUE TO SUGGEST THAT IT WILL BE HARD FOR
PRECIP TO MAKE IT MUCH FARTHER NORTH THAN THE NY/PA LINE THROUGH
06Z. IN FACT...THE BIGGEST ADJUSTMENT WITH THIS PACKAGE WAS
DELAYING THE RAIN MUCH LONGER ACROSS CNY...AND KEEPING THESE AREAS
DRY UNTIL CLOSER TO DAYBREAK IF NOT MID FRIDAY MORNING. THE NEW
QPF GUIDANCE IS IN FROM HPC AND AGREES WITH MORE EMPHASIS FARTHER
SOUTH AND EAST...AND DELAYED TIMING FARTHER NORTH AND WEST. THE
PREVIOUS AFD IS BELOW...
3 PM UPDATE...
WEAK LOW PRESSURE IN OHIO WILL TRACK ENE INTO SE NY FRI AFTN.
AHEAD OF THIS SFC LOW IS A 40 KT LOW LEVEL JET FEEDING MOISTURE
INTO THE LIFT AHEAD OF IT. THIS WILL INCREASE AS IT NEARS THE
COAST AND TAPS THE ATLANTIC. PWATS RISE TO AROUND 1.5 INCHES. SFC
PRESSURE WILL ALSO DECREASE SLOWLY AS IT APPROACHES. LIFT WILL
ALSO INCREASE AS THE NORTHERN STREAM MOVES SOUTH PUTTING THE AREA
IN THE RIGHT REAR WHILE THE SOUTHERN STREAM MOVES IN FOR THE FRONT
LEFT QUAD. MOST OF THE RAIN WILL BE AHEAD OF THE SFC LOW STARTING
IN NE PA THIS EVENING THEN INTO THE REST OF THE AREA LATE TONIGHT.
THE RAIN WILL TAPER OFF FROM SW TO NE FRIDAY AFTERNOON. RAINFALL
AMOUNTS WILL RANGE FROM A THIRD OF AN INCH IN THE CENTRAL SOUTHERN
TIER AND FINGER LAKES OF NY TO JUST OVER AN INCH IN NE PA AND THE
CATSKILLS. SOME LOCATIONS COULD APPROACH TWO INCHES DUE TO UPSLOPE
FLOW. THIS AMOUNT OF RAIN WILL NOT CAUSE ANY FLASH FLOODING.
RIVERS WILL RISE SOME BUT REMAIN WELL BELOW BANK FULL.
FOR TEMPERATURES WENT ON THE WARM SIDE TONIGHT WITH CLOUDS COMING
IN ATTM. FRIDAY GUIDANCE SIMILAR AND WENT CLOSE.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
3 PM UPDATE...
AFTER A QUIET MAINLY DRY PERIOD FRIDAY NIGHT TO SATURDAY NIGHT
SHOWERS WILL RETURN STARTING SUNDAY. FRIDAY NIGHT PARTIAL
CLEARING WITH WEAK HIGH PRESSURE. THE SFC LOW WILL CONTINUE
EAST TO THE GULF OF MAINE. THE CWA WILL BE WAITING FOR THE NEXT
SYSTEM WITH A DEEP UPPER LEVEL TROF DROPPING SE INTO NY. MODELS
SLOWER WITH THIS FEATURE SO SATURDAY IS LOOKING BETTER.
TEMPERATURES NEAR NORMAL BUT MOSTLY CLOUDY STILL. SOME LOW LEVEL
MOISTURE OFF OF THE LAKES WILL BRING SOME CUMULUS. 850MB TEMPS
FALL BACK TO PLUS 3C.
MODELS DIFFER ON THE TIMING OF THE UPPER LEVEL TROF. MOST OF THE
DIFFERENCE IS IN THE EXIT DURING THE EARLY PART OF THE LONG TERM.
MOST MODELS HAVE THE LOW OVER NY AND PA LATE SUNDAY. THE COLD AIR
ALOFT COMBINED WITH EARLY DAY SUNSHINE AND HEATING WILL MEAN
SHOWERS WILL INCREASE IN COVERAGE AND INTENSITY. HIGH TEMPS NEAR
NORMAL MIDDAY BEFORE FALLING IN THE SHOWERS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL LOW OVER NEW YORK STATE
WHICH LIFTS INTO EASTERN CANADA ON MONDAY. THIS FEATURE WILL
PROVIDE A CONTINUATION OF SHOWERY WEATHER THROUGH SUNDAY NIGHT
WITH GRADUAL IMPROVEMENT ON MONDAY. MONDAY NIGHT THROUGH
WEDNESDAY, UPPER LEVEL FLOW BECOMES MORE ZONAL WITH AREA BETWEEN
TWO SYSTEMS, A WEAK TROF IN EASTERN CANADA AND SFC LOW IN THE MID
ATLANTIC. REGION MAY REMAIN DRY THROUGH THIS PERIOD BUT DUE TO
LACK OF MODEL RUN TO RUN CONTINUITY CONFIDENCE NOT VERY HIGH. ON
THURSDAY, RETURN FLOW ON BACK SIDE OF SFC HIGH PRES OFF THE MID
ATLANTIC COAST MAY BRING THE THREAT FOR SHOWERS ESPECIALLY IN THE
SOUTHERN FORECAST AREA. TEMPS THROUGH PERIOD WILL RUN 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
LATEST RADAR TRENDS SHOWING MAIN RAIN SHIELD PUSHING THROUGH THE
TWIN TIERS AND REMAINDER OF NE PA THIS HR. SO FAR CONDITIONS HAVE
LARGELY REMAINED VFR...HOWEVER EXPECT CATEGORICAL DETERIORATION
WITHIN THE NEXT FEW HRS FOR ALL SITES EXCEPT SYR AND RME WHERE
RAIN SHIELD SHOULD REMAIN SOUTH. FOR NOW EXPECT IFR CONDITIONS ARE
BGM AFTER 08Z...WITH ELM/ITH/AVP LARGELY EXPECTED TO REMAIN MVFR.
CLOUDS WILL BE SLOW TO GO WITH MVFR CONDITIONS EXPECTED THROUGH
EARLY TO MID AFTERNOON. BEYOND THIS...DRIER AIR WILL MOVE INTO THE
REGION WHICH SHOULD RESULT IN GRADUAL IMPROVEMENT TOWARDS 00Z.
LIGHT EASTERLY WINDS EARLY ON WILL GRADUALLY SHIFT TOWARDS THE
NORTHWEST (5-10 KTS) BY AFTERNOON AS LOW EXITS TO THE EAST.
OUTLOOK...
SAT...GENERALLY VFR.
SUNDAY THROUGH MONDAY...MVFR SHOWERS POSSIBLE.
TUESDAY...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...HEDEN/PVN
SHORT TERM...TAC
LONG TERM...RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1227 AM EDT FRI SEP 28 2012
.SYNOPSIS...
CONDITIONS WILL DETERIORATE QUICKLY TONIGHT, AS LOW PRESSURE
TRACKS TOWARDS OUR AREA FROM OHIO. RAIN WILL MOSTLY FALL LATE
TONIGHT AND FRIDAY MORNING BEFORE ENDING FRIDAY AFTERNOON.
SATURDAY, WEAK HIGH PRESSURE WILL BRING MAINLY DRY WEATHER.
UNSETTLED CONDITIONS WILL RETURN SUNDAY INTO MONDAY AS AN UPPER
LEVEL DISTURBANCE MOVES THROUGH THE NORTHEAST UNITED STATES.
&&
.NEAR TERM /THROUGH TODAY/...
12 AM UPDATE..
QUICK UPDATE TO RMV POPS ACRS THE FAR NORTH FOR TONIGHT. RADAR
POPUP SKEW-T ACRS THE NRN ZONES INDICATE DRY LAYER FM SFC-H7. 00Z
RAOBS INDICATE SAT/D AIRMASS TO THE SOUTH AND DRY AIR TO THE
NORTH. THIS APPEARS TO SUPPORT BUFKIT SNDGS AND 00Z NAM GUIDANCE
INDICATES A SLOW SATURATION OF ATMOS AFT 12Z ACRS THE NORTH...THUS
HV TRIMMED POPS BACK THRU 12Z. PREVIOUS AFD BELOW.
9 PM UPDATE...
RAIN NOW MOVING INTO NEPA. FROM RADAR RETURNS BIGGEST IMPACT WILL
REMAIN HERE FOR THE NEXT FEW HOURS...WITH VERY LIGHT SHOWERS JUST
GETTING INTO THE SOUTHERN TIER OF NY...WITH DRY WEATHER NORTH OF
HERE.
7 PM UPDATE...
AN AREA OF LIGHT RAIN ACROSS CENTRAL PA CONTINUES TO SLOWLY LIFT
NORTHEAST BUT IS HAVING SOME TROUBLE AT THE MOMENT AS HIGH
PRESSURE OVER QUEBEC IS SLOW TO LOSE ITS GRIP ON OUR AREA. THIS IS
MOST EVIDENT WITH A QUICK GLANCE AT SURFACE DEW POINTS...SHOWING
LOW TO MID 40S ACROSS CNY...BUT CREEPING INTO THE MID 50S DOWN IN
NEPA. AS OUR ATMOSPHERE CONTINUES TO MOISTEN UP AND WE BEGIN TO
SEE A MID DECK AROUND 5KFT DEVELOP...SHOWERS ARE LIKELY IN NEPA
BETWEEN 02Z AND 04Z...OR JUST A TAD SLOWER THAN THE PREVIOUS
FORECAST. THE 18Z NAM...ALONG WITH THE HIGHER RESOLUTION MODELS OF
THE ARW/NMM AND HRRR CONTINUE TO SUGGEST THAT IT WILL BE HARD FOR
PRECIP TO MAKE IT MUCH FARTHER NORTH THAN THE NY/PA LINE THROUGH
06Z. IN FACT...THE BIGGEST ADJUSTMENT WITH THIS PACKAGE WAS
DELAYING THE RAIN MUCH LONGER ACROSS CNY...AND KEEPING THESE AREAS
DRY UNTIL CLOSER TO DAYBREAK IF NOT MID FRIDAY MORNING. THE NEW
QPF GUIDANCE IS IN FROM HPC AND AGREES WITH MORE EMPHASIS FARTHER
SOUTH AND EAST...AND DELAYED TIMING FARTHER NORTH AND WEST. THE
PREVIOUS AFD IS BELOW...
3 PM UPDATE...
WEAK LOW PRESSURE IN OHIO WILL TRACK ENE INTO SE NY FRI AFTN.
AHEAD OF THIS SFC LOW IS A 40 KT LOW LEVEL JET FEEDING MOISTURE
INTO THE LIFT AHEAD OF IT. THIS WILL INCREASE AS IT NEARS THE
COAST AND TAPS THE ATLANTIC. PWATS RISE TO AROUND 1.5 INCHES. SFC
PRESSURE WILL ALSO DECREASE SLOWLY AS IT APPROACHES. LIFT WILL
ALSO INCREASE AS THE NORTHERN STREAM MOVES SOUTH PUTTING THE AREA
IN THE RIGHT REAR WHILE THE SOUTHERN STREAM MOVES IN FOR THE FRONT
LEFT QUAD. MOST OF THE RAIN WILL BE AHEAD OF THE SFC LOW STARTING
IN NE PA THIS EVENING THEN INTO THE REST OF THE AREA LATE TONIGHT.
THE RAIN WILL TAPER OFF FROM SW TO NE FRIDAY AFTERNOON. RAINFALL
AMOUNTS WILL RANGE FROM A THIRD OF AN INCH IN THE CENTRAL SOUTHERN
TIER AND FINGER LAKES OF NY TO JUST OVER AN INCH IN NE PA AND THE
CATSKILLS. SOME LOCATIONS COULD APPROACH TWO INCHES DUE TO UPSLOPE
FLOW. THIS AMOUNT OF RAIN WILL NOT CAUSE ANY FLASH FLOODING.
RIVERS WILL RISE SOME BUT REMAIN WELL BELOW BANK FULL.
FOR TEMPERATURES WENT ON THE WARM SIDE TONIGHT WITH CLOUDS COMING
IN ATTM. FRIDAY GUIDANCE SIMILAR AND WENT CLOSE.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
3 PM UPDATE...
AFTER A QUIET MAINLY DRY PERIOD FRIDAY NIGHT TO SATURDAY NIGHT
SHOWERS WILL RETURN STARTING SUNDAY. FRIDAY NIGHT PARTIAL
CLEARING WITH WEAK HIGH PRESSURE. THE SFC LOW WILL CONTINUE
EAST TO THE GULF OF MAINE. THE CWA WILL BE WAITING FOR THE NEXT
SYSTEM WITH A DEEP UPPER LEVEL TROF DROPPING SE INTO NY. MODELS
SLOWER WITH THIS FEATURE SO SATURDAY IS LOOKING BETTER.
TEMPERATURES NEAR NORMAL BUT MOSTLY CLOUDY STILL. SOME LOW LEVEL
MOISTURE OFF OF THE LAKES WILL BRING SOME CUMULUS. 850MB TEMPS
FALL BACK TO PLUS 3C.
MODELS DIFFER ON THE TIMING OF THE UPPER LEVEL TROF. MOST OF THE
DIFFERENCE IS IN THE EXIT DURING THE EARLY PART OF THE LONG TERM.
MOST MODELS HAVE THE LOW OVER NY AND PA LATE SUNDAY. THE COLD AIR
ALOFT COMBINED WITH EARLY DAY SUNSHINE AND HEATING WILL MEAN
SHOWERS WILL INCREASE IN COVERAGE AND INTENSITY. HIGH TEMPS NEAR
NORMAL MIDDAY BEFORE FALLING IN THE SHOWERS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
EXTENDED PERIOD BEGINS WITH AN UPPER LEVEL LOW OVER NEW YORK STATE
WHICH LIFTS INTO EASTERN CANADA ON MONDAY. THIS FEATURE WILL
PROVIDE A CONTINUATION OF SHOWERY WEATHER THROUGH SUNDAY NIGHT
WITH GRADUAL IMPROVEMENT ON MONDAY. MONDAY NIGHT THROUGH
WEDNESDAY, UPPER LEVEL FLOW BECOMES MORE ZONAL WITH AREA BETWEEN
TWO SYSTEMS, A WEAK TROF IN EASTERN CANADA AND SFC LOW IN THE MID
ATLANTIC. REGION MAY REMAIN DRY THROUGH THIS PERIOD BUT DUE TO
LACK OF MODEL RUN TO RUN CONTINUITY CONFIDENCE NOT VERY HIGH. ON
THURSDAY, RETURN FLOW ON BACK SIDE OF SFC HIGH PRES OFF THE MID
ATLANTIC COAST MAY BRING THE THREAT FOR SHOWERS ESPECIALLY IN THE
SOUTHERN FORECAST AREA. TEMPS THROUGH PERIOD WILL RUN 5 TO 10
DEGREES ABOVE NORMAL.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
00Z FRI UPDATE... VFR WILL CONTINUE THIS EVE...BEFORE CONDS
DETERIORATE LATER TNT INTO FRI...AS LWR CIGS AND RAIN MOVE IN FOR
KAVP...KELM...KBGM...AND KITH. THE MOST PERSISTENT RAIN SHOULD
OCCUR AT KAVP (MORE INTERMITTENT AT KELM...KBGM...AND KITH)...BUT
MVFR CONDS SHOULD PREVAIL AT EACH SITE. IN GENERAL...STEADIER RAIN
SHOULD TAPER OFF BY MIDDAY FRI...BUT MVFR CIGS ARE LIKELY TO LAST LONGER.
FOR KSYR AND KRME...VFR IS EXPECTED TO REMAIN PREVALENT...AS THE
RAIN SHIELD LARGELY BYPASSES THESE SITES TO THE S.
LGT SFC WINDS OVERNIGHT (AOB 5 KT)...WILL BECOME N TO NW AND
INCREASE TO ARND 10 KT FRI.
OUTLOOK...
FRI NGT...IMPROVING TO VFR.
SAT...GENERALLY VFR.
SUNDAY THROUGH MONDAY...MVFR SHOWERS POSSIBLE.
TUESDAY...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...HEDEN/PVN
SHORT TERM...TAC
LONG TERM...RRM
AVIATION...MLJ/RRM
AREA FORECAST DISCUSSION
NWS NORMAN OK
1034 AM CDT FRI SEP 28 2012
.DISCUSSION...
THE AREA OF RAIN OVER TEXAS...JUST SOUTH AND SOUTHWEST OF OUR
TEXAS COUNTIES...SEEMS TO BE STRUGGLING TO EXPAND INTO OUR
COUNTIES. NEVERTHELESS...SHORT-RANGE MODELS CONTINUE TO BRING THE
RAIN INTO WESTERN NORTH TEXAS DURING THE DAY TODAY. SO...WILL
RETAIN THE HIGH POPS IN THAT AREA. SIMILARLY...MODELS SUPPORT THE
LOWER POPS ELSEWHERE. GIVEN THE VERY MOIST ATMOSPHERE...IT IS HARD
TO RULE OUT THE CHANCE OF RAIN ANYWHERE IN OUR FORECAST AREA
TODAY.
ALL THE OTHER FORECAST ELEMENTS ALSO APPEAR TO BE WELL-
HANDLED...SO NO CHANGES ARE PLANNED FOR THIS MORNING.
&&
.PREV DISCUSSION... /ISSUED 654 AM CDT FRI SEP 28 2012/
DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
AVIATION...
GENERALLY HAVE VERY LOW CONFIDENCE AT ALL SITES THROUGH
18Z...THEN MODERATE CONFIDENCE 18-03Z...THEN LOW CONFIDENCE
AFTER 03Z.
VLIFR CONDITIONS AND FG WILL OCCUR NEAR KOKC...KPNC... KCSM...AND
KHBR THROUGH AT LEAST 14Z...AND MAY LINGER AS LONG AS 17Z. MVFR
CONDITIONS ARE EXPECTED NEAR KSPS...KOUN...AND KLAW THROUGH AT
LEAST 14Z.
BY 18Z...WENT OPTIMISTIC WITH VFR CONDITIONS EVERYWHERE.
MVFR OR LOWER CONDITIONS MAY RETURN TO ANY SITE AFTER
03Z...ESPECIALLY OVER NORTHERN OKLAHOMA WHERE BR/FG MAY
REDEVELOP AND WITH -RA/BR OVER SOUTHERN OKLAHOMA AND
WESTERN NORTH TEXAS. WENT MVFR CONDITIONS WITH -RA/BR
AT KSPS AFTER 06Z WHERE CONFIDENCE IS SLIGHTLY HIGHER.
MBS
PREV DISCUSSION... /ISSUED 431 AM CDT FRI SEP 28 2012/
DISCUSSION...
FOG THIS MORNING AND RAIN CHANCES THROUGH SUNDAY NIGHT ARE
THE MAIN CONCERNS.
THROUGH 11 AM CDT THIS MORNING...AREAS OF FOG WILL REDUCE
VISIBILITIES BELOW 1 MILE IN SOME LOCATIONS. DO NOT PLAN ON
ISSUING A DENSE FOG ADVISORY AS VISIBILITIES SHOULD REMAIN
MAINLY ABOVE 1/4 MILE AND AS VARIOUS CLOUD LAYERS SHOULD
PREVENT WIDESPREAD DENSE FOG DEVELOPMENT.
AS FOR RAIN CHANCES TODAY...LOWERED THEM EAST OF A PONCA
CITY TO WICHITA FALLS LINE...INCLUDING OKLAHOMA CITY DUE
TO THE LACK OF LIFT. BASED ON LATEST RADAR AND HRRR RUNS...
CURRENT SHOWERS OVER FAR NORTHWEST OKLAHOMA WILL LIKELY DISSIPATE
BY 11 AM CDT AS THE LOW LEVEL JET WEAKENS AND A MID LEVEL
DISTURBANCE OVER THE CENTRAL PLAINS PULLS NORTHEAST OF THE AREA.
INCREASING RAIN CHANCES WILL ARRIVE THIS AFTERNOON OVER WESTERN
NORTH TEXAS AND FAR SOUTHWESTERN OKLAHOMA AHEAD OF AN EJECTING MID
LEVEL DISTURBANCE NEAR THE GULF OF CALIFORNIA. CANNOT RULE OUT
ISOLATED NEW DEVELOPMENT NEARLY ANYWHERE TODAY AS THE AIR IS VERY
MOIST...BUT THIS SEEMS UNLIKELY...ESPECIALLY AS ABUNDANT CLOUD
COVER WILL MAKE REACHING CONVECTIVE TEMPERATURES IN THE 81 TO 86
DEGREE RANGE DIFFICULT.
THERE IS A LOW CHANCE FOR LOCALLY HEAVY RAINFALL WITH ANY SHOWER
OR STORM TODAY WITH PRECIPITABLE WATER VALUES ABOUT 150 PERCENT
OF NORMAL AND SLOW STORM MOVEMENT. HOWEVER...LACK OF SIGNIFICANT
INSTABILITY AND FAIRLY WEAK SHEAR WILL KEEP ANY HEAVY RAINFALL
LOCALIZED. SEVERE STORMS ARE UNLIKELY AS WELL.
WENT NEAR OR SLIGHTLY BELOW 00Z MOS GUIDANCE TEMPERATURES FOR
HIGHS TODAY DUE TO ABUNDANT CLOUD COVER COVER.
TONIGHT INTO SATURDAY...RAIN CHANCES MAY INCREASE...ESPECIALLY
OVER WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA AS THE POORLY
SAMPLED LOW PRESSURE DISTURBANCE MENTIONED ABOVE APPROACHES.
LOCALLY HEAVY RAINFALL MAY BE POSSIBLE DUE TO HIGH PRECIPITABLE
WATER VALUES...THOUGH CONFIDENCE REMAINS LOW. NO SEVERE STORMS
ARE EXPECTED. WENT TOWARDS THE COOLER 00Z GUIDANCE HIGHS ON
SATURDAY DUE TO ABUNDANT CLOUD COVER. THERE IS AN OUTSIDE SHOT
FOG MAY DEVELOP OVER NORTHERN OKLAHOMA IF SKIES CAN CLEAR.
SATURDAY NIGHT INTO SUNDAY NIGHT...FOG DEVELOPMENT MAY BE
CONCERN...ESPECIALLY SUNDAY MORNING ACROSS THE AREA. WAS NOT
CONFIDENT TO MENTION. KEPT LOW RAIN CHANCES OVER SOUTHEAST
OKLAHOMA AS WELL AS FAR WESTERN OKLAHOMA AND NORTH TEXAS
DURING THIS TIME FRAME.
MONDAY THROUGH THURSDAY...DRY AND WARMER WEATHER CAN BE
EXPECTED. ABOVE AVERAGE TEMPERATURES ARE FORECAST...THOUGH
CONFIDENCE IS NOT THE GREATEST...ESPECIALLY WEDNESDAY AND
BEYOND AS ANOTHER COLD FRONT MAY MOVE THROUGH THE AREA.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 79 64 77 60 / 20 30 30 10
HOBART OK 74 64 79 59 / 50 50 30 10
WICHITA FALLS TX 79 66 77 62 / 50 50 50 20
GAGE OK 77 58 77 55 / 50 30 20 10
PONCA CITY OK 79 58 79 53 / 30 20 10 10
DURANT OK 85 66 75 63 / 30 60 60 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
23/04
AREA FORECAST DISCUSSION
NWS NORMAN OK
654 AM CDT FRI SEP 28 2012
.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
&&
.AVIATION...
GENERALLY HAVE VERY LOW CONFIDENCE AT ALL SITES THROUGH
18Z...THEN MODERATE CONFIDENCE 18-03Z...THEN LOW CONFIDENCE
AFTER 03Z.
VLIFR CONDITIONS AND FG WILL OCCUR NEAR KOKC...KPNC... KCSM...AND
KHBR THROUGH AT LEAST 14Z...AND MAY LINGER AS LONG AS 17Z. MVFR
CONDITIONS ARE EXPECTED NEAR KSPS...KOUN...AND KLAW THROUGH AT
LEAST 14Z.
BY 18Z...WENT OPTIMISTIC WITH VFR CONDITIONS EVERYWHERE.
MVFR OR LOWER CONDITIONS MAY RETURN TO ANY SITE AFTER
03Z...ESPECIALLY OVER NORTHERN OKLAHOMA WHERE BR/FG MAY
REDEVELOP AND WITH -RA/BR OVER SOUTHERN OKLAHOMA AND
WESTERN NORTH TEXAS. WENT MVFR CONDITIONS WITH -RA/BR
AT KSPS AFTER 06Z WHERE CONFIDENCE IS SLIGHTLY HIGHER.
MBS
&&
.PREV DISCUSSION... /ISSUED 431 AM CDT FRI SEP 28 2012/
DISCUSSION...
FOG THIS MORNING AND RAIN CHANCES THROUGH SUNDAY NIGHT ARE
THE MAIN CONCERNS.
THROUGH 11 AM CDT THIS MORNING...AREAS OF FOG WILL REDUCE
VISIBILITIES BELOW 1 MILE IN SOME LOCATIONS. DO NOT PLAN ON
ISSUING A DENSE FOG ADVISORY AS VISIBILITIES SHOULD REMAIN
MAINLY ABOVE 1/4 MILE AND AS VARIOUS CLOUD LAYERS SHOULD
PREVENT WIDESPREAD DENSE FOG DEVELOPMENT.
AS FOR RAIN CHANCES TODAY...LOWERED THEM EAST OF A PONCA
CITY TO WICHITA FALLS LINE...INCLUDING OKLAHOMA CITY DUE
TO THE LACK OF LIFT. BASED ON LATEST RADAR AND HRRR RUNS...
CURRENT SHOWERS OVER FAR NORTHWEST OKLAHOMA WILL LIKELY DISSIPATE
BY 11 AM CDT AS THE LOW LEVEL JET WEAKENS AND A MID LEVEL
DISTURBANCE OVER THE CENTRAL PLAINS PULLS NORTHEAST OF THE AREA.
INCREASING RAIN CHANCES WILL ARRIVE THIS AFTERNOON OVER WESTERN
NORTH TEXAS AND FAR SOUTHWESTERN OKLAHOMA AHEAD OF AN EJECTING MID
LEVEL DISTURBANCE NEAR THE GULF OF CALIFORNIA. CANNOT RULE OUT
ISOLATED NEW DEVELOPMENT NEARLY ANYWHERE TODAY AS THE AIR IS VERY
MOIST...BUT THIS SEEMS UNLIKELY...ESPECIALLY AS ABUNDANT CLOUD
COVER WILL MAKE REACHING CONVECTIVE TEMPERATURES IN THE 81 TO 86
DEGREE RANGE DIFFICULT.
THERE IS A LOW CHANCE FOR LOCALLY HEAVY RAINFALL WITH ANY SHOWER
OR STORM TODAY WITH PRECIPITABLE WATER VALUES ABOUT 150 PERCENT
OF NORMAL AND SLOW STORM MOVEMENT. HOWEVER...LACK OF SIGNIFICANT
INSTABILITY AND FAIRLY WEAK SHEAR WILL KEEP ANY HEAVY RAINFALL
LOCALIZED. SEVERE STORMS ARE UNLIKELY AS WELL.
WENT NEAR OR SLIGHTLY BELOW 00Z MOS GUIDANCE TEMPERATURES FOR
HIGHS TODAY DUE TO ABUNDANT CLOUD COVER COVER.
TONIGHT INTO SATURDAY...RAIN CHANCES MAY INCREASE...ESPECIALLY
OVER WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA AS THE POORLY
SAMPLED LOW PRESSURE DISTURBANCE MENTIONED ABOVE APPROACHES.
LOCALLY HEAVY RAINFALL MAY BE POSSIBLE DUE TO HIGH PRECIPITABLE
WATER VALUES...THOUGH CONFIDENCE REMAINS LOW. NO SEVERE STORMS
ARE EXPECTED. WENT TOWARDS THE COOLER 00Z GUIDANCE HIGHS ON
SATURDAY DUE TO ABUNDANT CLOUD COVER. THERE IS AN OUTSIDE SHOT
FOG MAY DEVELOP OVER NORTHERN OKLAHOMA IF SKIES CAN CLEAR.
SATURDAY NIGHT INTO SUNDAY NIGHT...FOG DEVELOPMENT MAY BE
CONCERN...ESPECIALLY SUNDAY MORNING ACROSS THE AREA. WAS NOT
CONFIDENT TO MENTION. KEPT LOW RAIN CHANCES OVER SOUTHEAST
OKLAHOMA AS WELL AS FAR WESTERN OKLAHOMA AND NORTH TEXAS
DURING THIS TIME FRAME.
MONDAY THROUGH THURSDAY...DRY AND WARMER WEATHER CAN BE
EXPECTED. ABOVE AVERAGE TEMPERATURES ARE FORECAST...THOUGH
CONFIDENCE IS NOT THE GREATEST...ESPECIALLY WEDNESDAY AND
BEYOND AS ANOTHER COLD FRONT MAY MOVE THROUGH THE AREA.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 79 64 77 60 / 20 30 30 10
HOBART OK 74 64 79 59 / 50 50 30 10
WICHITA FALLS TX 79 66 77 62 / 50 50 50 20
GAGE OK 77 58 77 55 / 50 30 20 10
PONCA CITY OK 79 58 79 53 / 30 20 10 10
DURANT OK 85 66 75 63 / 30 60 60 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17/17
AREA FORECAST DISCUSSION
NWS NORMAN OK
431 AM CDT FRI SEP 28 2012
.DISCUSSION...
FOG THIS MORNING AND RAIN CHANCES THROUGH SUNDAY NIGHT ARE
THE MAIN CONCERNS.
THROUGH 11 AM CDT THIS MORNING...AREAS OF FOG WILL REDUCE
VISIBILITIES BELOW 1 MILE IN SOME LOCATIONS. DO NOT PLAN ON
ISSUING A DENSE FOG ADVISORY AS VISIBILITIES SHOULD REMAIN
MAINLY ABOVE 1/4 MILE AND AS VARIOUS CLOUD LAYERS SHOULD
PREVENT WIDESPREAD DENSE FOG DEVELOPMENT.
AS FOR RAIN CHANCES TODAY...LOWERED THEM EAST OF A PONCA
CITY TO WICHITA FALLS LINE...INCLUDING OKLAHOMA CITY DUE
TO THE LACK OF LIFT. BASED ON LATEST RADAR AND HRRR RUNS...
CURRENT SHOWERS OVER FAR NORTHWEST OKLAHOMA WILL LIKELY DISSIPATE
BY 11 AM CDT AS THE LOW LEVEL JET WEAKENS AND A MID LEVEL
DISTURBANCE OVER THE CENTRAL PLAINS PULLS NORTHEAST OF THE AREA.
INCREASING RAIN CHANCES WILL ARRIVE THIS AFTERNOON OVER WESTERN
NORTH TEXAS AND FAR SOUTHWESTERN OKLAHOMA AHEAD OF AN EJECTING MID
LEVEL DISTURBANCE NEAR THE GULF OF CALIFORNIA. CANNOT RULE OUT
ISOLATED NEW DEVELOPMENT NEARLY ANYWHERE TODAY AS THE AIR IS VERY
MOIST...BUT THIS SEEMS UNLIKELY...ESPECIALLY AS ABUNDANT CLOUD
COVER WILL MAKE REACHING CONVECTIVE TEMPERATURES IN THE 81 TO 86
DEGREE RANGE DIFFICULT.
THERE IS A LOW CHANCE FOR LOCALLY HEAVY RAINFALL WITH ANY SHOWER
OR STORM TODAY WITH PRECIPITABLE WATER VALUES ABOUT 150 PERCENT
OF NORMAL AND SLOW STORM MOVEMENT. HOWEVER...LACK OF SIGNIFICANT
INSTABILITY AND FAIRLY WEAK SHEAR WILL KEEP ANY HEAVY RAINFALL
LOCALIZED. SEVERE STORMS ARE UNLIKELY AS WELL.
WENT NEAR OR SLIGHTLY BELOW 00Z MOS GUIDANCE TEMPERATURES FOR
HIGHS TODAY DUE TO ABUNDANT CLOUD COVER COVER.
TONIGHT INTO SATURDAY...RAIN CHANCES MAY INCREASE...ESPECIALLY
OVER WESTERN NORTH TEXAS AND SOUTHERN OKLAHOMA AS THE POORLY
SAMPLED LOW PRESSURE DISTURBANCE MENTIONED ABOVE APPROACHES.
LOCALLY HEAVY RAINFALL MAY BE POSSIBLE DUE TO HIGH PRECIPITABLE
WATER VALUES...THOUGH CONFIDENCE REMAINS LOW. NO SEVERE STORMS
ARE EXPECTED. WENT TOWARDS THE COOLER 00Z GUIDANCE HIGHS ON
SATURDAY DUE TO ABUNDANT CLOUD COVER. THERE IS AN OUTSIDE SHOT
FOG MAY DEVELOP OVER NORTHERN OKLAHOMA IF SKIES CAN CLEAR.
SATURDAY NIGHT INTO SUNDAY NIGHT...FOG DEVELOPMENT MAY BE
CONCERN...ESPECIALLY SUNDAY MORNING ACROSS THE AREA. WAS NOT
CONFIDENT TO MENTION. KEPT LOW RAIN CHANCES OVER SOUTHEAST
OKLAHOMA AS WELL AS FAR WESTERN OKLAHOMA AND NORTH TEXAS
DURING THIS TIME FRAME.
MONDAY THROUGH THURSDAY...DRY AND WARMER WEATHER CAN BE
EXPECTED. ABOVE AVERAGE TEMPERATURES ARE FORECAST...THOUGH
CONFIDENCE IS NOT THE GREATEST...ESPECIALLY WEDNESDAY AND
BEYOND AS ANOTHER COLD FRONT MAY MOVE THROUGH THE AREA.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 79 64 77 60 / 20 30 30 10
HOBART OK 74 64 79 59 / 50 50 30 10
WICHITA FALLS TX 79 66 77 62 / 50 50 50 20
GAGE OK 77 58 77 55 / 50 30 20 10
PONCA CITY OK 79 58 79 53 / 30 20 10 10
DURANT OK 85 66 75 63 / 30 60 60 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
748 AM EDT FRI SEP 28 2012
.SYNOPSIS...
A STRONG DISTURBANCE ALOFT WILL MOVE EAST OF THE REGION TODAY.
DRIER AIR WILL MOVE INTO THE REGION LATER TODAY AND
SATURDAY...BEFORE A DEVELOPING UPPER LOW BRINGS MORE UNSETTLED
WEATHER LATER IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4AM UPDATE...
SHORTWAVE TROF AXIS IS MOVING INTO EASTERN PA AT THIS HOUR...WITH
THE STEADIEST RAINS NOW MOVING THRU NERN PA. THE TRAILING SHOWERS
EXTEND BACK TO THE LOWER SUSQ VALLEY WHERE ACTIVITY WILL WIND DOWN
IN THE HOURS NEAR AND JUST AFTER SUNRISE. HRRR TIMING HAS THE LAST
OF THE RAINS MOVING OUT OF THE FCST AREA AROUND 14Z.
IT WILL BE A MOSTLY CLOUDY DAY WITH BRIGHTENING SKIES FOR THE
AFTERNOON. STILL CANNOT RULE OUT A STRAY SHOWER AFTER MID
DAY...BUT CHANCES ARE LOW AND FOR NOW I WILL NOT MENTION RAIN.
HIGHS TODAY WILL RANGE FROM THE LOW/MID 60S OVER THE FAR NW TO MID
70S OVER THE SE. FOR THE TIME OF YEAR THAT WILL BE A LITTLE COOLER
THAN NORMAL NW TO A LITTLE WARMER THAN NORMAL OVER THE SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
EXPECT CLEARING SKIES TONIGHT AS SFC HIGH PRESSURE RIDGES IN FROM
THE OHIO VALLEY. IF CLEARING OCCURS EARLY ENOUGH...FOG COULD
BECOME AN ISSUE. LOWS WILL BOTTOM OUT VERY NEAR CLIMO NORMS...40S
NORTH TO 50S SOUTH.
LOW LEVEL COLD ADVECTION AND MOISTURE WILL COMBINE FOR THE
DEVELOPMENT OF STRATOCU ON SATURDAY. HAVE PUT A VERY SMALL CHANCE
OF RAIN OVER NRN AREAS...WITH LITTLE MORE THAN A FEW SPRINKLES
ELSEWHERE.
HIGHS IN THE 60S WILL BE A BIT BELOW NORMAL FOR A CHANGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
INCREASINGLY UNSETTLED CONDITIONS RETURN BY THE END OF THE
WEEKEND AS AN UPPER LOW NEAR JAMES BAY DIVES SSW INTO THE GR LAKES
BEFORE EJECTING BACK INTO ERN CANADA BY MONDAY. SUNDAY LOOKS LIKE
A COOL AND SHOWERY DAY AS THE UPPER TROF/LOW BOTTOM OUT AND BEGIN
TO SLIDE INTO THE AREA.
AFTER WE DRY OUT FOR A BIT MONDAY...GUIDANCE STARTS TO DIVERGE FOR
MIDWEEK. THE ECMWF IS AGGRESSIVE IN DRAGGING GULF MOISTURE
NORTHWARD AS IT CARVES OUT A DEEP TROF OVER THE ERN US BY TUESDAY.
OPERATIONAL GFS KEEPS THE SRN MOISTURE AND ENERGY MORE
SEPARATE...NOT NEARLY AS AGGRESSIVE AS THE ECMWF. THE GEFS LOOKS
VERY MUCH LIKE THE GFS ALOFT...BUT SHOWS HIGHER POPS INTO MID
WEEK. WITH CONFLICTING GUIDANCE SUCH AS IT IS...I BROUGHT IN A
CHANCE OF RAIN TUES INTO WED.
ONCE THE EASTERN SYSTEM IS RESOLVED...THE END OF THE WEEK LOOKS
DRIER IN ALL THE GUIDANCE. TEMPS SHOULD ACTUALLY BE A BIT ABOVE
NORMAL BEFORE HIGH PRESSURE LIKELY BRINGS COOLER AIR FOR NEXT
WEEKEND.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
A WEAK AREA OF SURFACE LOW PRESSURE WAS CENTERED NEAR KMDT AT
1130Z...AND WILL COMBINE WITH A POTENT...AND SLOW MOVING UPPER
AIR DISTURBANCE TO BRING NUMEROUS SHOWERS /AND LOW FLYING
CONDITIONS/ NEAR AND TO THE EAST OF A LINE FROM KIPT TO KSEG
THROUGH 16Z.
AFTERWARD...AND ELSEWHERE ACROSS THE REGION MAINLY IFR TO LIFR
CIGS /AND MVFR TO IFR VSBYS IN AREAS OF DRIZZLE/ WILL PERSIST AT
MOST CENTRAL PENN TAF SITES THROUGH THE REST OF THIS MORNING...
BEFORE GRADUAL IMPROVING DURING THE AFTERNOON HOURS.
VSBYS WILL BECOME MAINLY VFR THIS AFTERNOON /WITH LINGERING AREAS
OF MVFR CIGS/ AS THE LOW PRESSURE AREA MOVES OFF TOWARD THE NEW
ENGLAND COAST. AREAS OF MVFR CIGS AND VSBYS WILL PERSIST INTO
TONIGHT...MAINLY ACROSS THE HIGHER ELEVATION AIRFIELDS OF WESTERN
PENN /KJST...NORTH TO KBFD/.
OUTLOOK...
SAT...MAINLY VFR. MVFR CIGS POSS NW.
SUN...VFR/AREAS OF MVFR IN SHOWERS - MAINLY ACROSS THE WESTERN
MTNS OF PENN DURING DAY...BECOMING AREA-WIDE SUN NIGHT.
MON...MAINLY VFR...WITH MVFR POSS IN THE MORNING.
TUE...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
503 AM EDT FRI SEP 28 2012
.SYNOPSIS...
A STRONG DISTURBANCE ALOFT WILL MOVE EAST OF THE REGION TODAY.
DRIER AIR WILL MOVE INTO THE REGION LATER TODAY AND
SATURDAY...BEFORE A DEVELOPING UPPER LOW BRINGS MORE UNSETTLED
WEATHER LATER IN THE WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4AM UPDATE...
SHORTWAVE TROF AXIS IS MOVING INTO EASTERN PA AT THIS HOUR...WITH
THE STEADIEST RAINS NOW MOVING THRU NERN PA. THE TRAILING SHOWERS
EXTEND BACK TO THE LOWER SUSQ VALLEY WHERE ACTIVITY WILL WIND DOWN
IN THE HOURS NEAR AND JUST AFTER SUNRISE. HRRR TIMING HAS THE LAST
OF THE RAINS MOVING OUT OF THE FCST AREA AROUND 14Z.
IT WILL BE A MOSTLY CLOUDY DAY WITH BRIGHTENING SKIES FOR THE
AFTERNOON. STILL CANNOT RULE OUT A STRAY SHOWER AFTER MID
DAY...BUT CHANCES ARE LOW AND FOR NOW I WILL NOT MENTION RAIN.
HIGHS TODAY WILL RANGE FROM THE LOW/MID 60S OVER THE FAR NW TO MID
70S OVER THE SE. FOR THE TIME OF YEAR THAT WILL BE A LITTLE COOLER
THAN NORMAL NW TO A LITTLE WARMER THAN NORMAL OVER THE SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
EXPECT CLEARING SKIES TONIGHT AS SFC HIGH PRESSURE RIDGES IN FROM
THE OHIO VALLEY. IF CLEARING OCCURS EARLY ENOUGH...FOG COULD
BECOME AN ISSUE. LOWS WILL BOTTOM OUT VERY NEAR CLIMO NORMS...40S
NORTH TO 50S SOUTH.
LOW LEVEL COLD ADVECTION AND MOISTURE WILL COMBINE FOR THE
DEVELOPMENT OF STRATOCU ON SATURDAY. HAVE PUT A VERY SMALL CHANCE
OF RAIN OVER NRN AREAS...WITH LITTLE MORE THAN A FEW SPRINKLES
ELSEWHERE.
HIGHS IN THE 60S WILL BE A BIT BELOW NORMAL FOR A CHANGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
INCREASINGLY UNSETTLED CONDITIONS RETURN BY THE END OF THE
WEEKEND AS AN UPPER LOW NEAR JAMES BAY DIVES SSW INTO THE GR LAKES
BEFORE EJECTING BACK INTO ERN CANADA BY MONDAY. SUNDAY LOOKS LIKE
A COOL AND SHOWERY DAY AS THE UPPER TROF/LOW BOTTOM OUT AND BEGIN
TO SLIDE INTO THE AREA.
AFTER WE DRY OUT FOR A BIT MONDAY...GUIDANCE STARTS TO DIVERGE FOR
MIDWEEK. THE ECMWF IS AGGRESSIVE IN DRAGGING GULF MOISTURE
NORTHWARD AS IT CARVES OUT A DEEP TROF OVER THE ERN US BY TUESDAY.
OPERATIONAL GFS KEEPS THE SRN MOISTURE AND ENERGY MORE
SEPARATE...NOT NEARLY AS AGGRESSIVE AS THE ECMWF. THE GEFS LOOKS
VERY MUCH LIKE THE GFS ALOFT...BUT SHOWS HIGHER POPS INTO MID
WEEK. WITH CONFLICTING GUIDANCE SUCH AS IT IS...I BROUGHT IN A
CHANCE OF RAIN TUES INTO WED.
ONCE THE EASTERN SYSTEM IS RESOLVED...THE END OF THE WEEK LOOKS
DRIER IN ALL THE GUIDANCE. TEMPS SHOULD ACTUALLY BE A BIT ABOVE
NORMAL BEFORE HIGH PRESSURE LIKELY BRINGS COOLER AIR FOR NEXT
WEEKEND.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
SLOW MOVING SURFACE LOW PRESSURE CENTERED NEAR KUNV AT 06Z...WILL
COMBINE WITH A POTENT UPPER AIR DISTURBANCE TO BRING WIDESPREAD
MODERATE TO HEAVY RAIN SHOWERS /AND LOW FLYING CONDITIONS/ NEAR
AND TO THE EAST OF A LINE FROM KHGR...TO KMDT...KSEG AND KIPT
THROUGH 09Z.
AFTERWARD...AND ELSEWHERE ACROSS THE REGION IFR TO LIFR CIGS /AND
MVFR TO IFR VSBYS IN AREAS OF LIGHTER SHOWERS AND DRIZZLE/ WILL
PERSIST AT MOST CENTRAL PENN TAF SITES THROUGH 14Z BEFORE GRADUAL
IMPROVING FOR THE LATE MORNING AND AFTERNOON HOURS.
VSBYS WILL BECOME MAINLY VFR THIS FRIDAY AFTERNOON AS THE LOW
PRESSURE AREA MOVES OFF TOWARD THE NEW ENGLAND COAST...BUT AREAS
OF MVFR VSBYS WILL PERSIST INTO TONIGHT...MAINLY ACROSS THE HIGHER
ELEVATION AIRFIELDS OF WESTERN PENN /KJST...NORTH TO KBFD/.
OUTLOOK...
SAT...MAINLY VFR. MVFR CIGS POSS NW.
SUN...VFR/AREAS OF MVFR IN SHOWERS - MAINLY WEST DURING
DAY...AREA-WIDE SUN NIGHT.
MON...MAINLY VFR...WITH MVFR POSS IN THE MORNING.
TUE...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...LAMBERT/RXR
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
126 PM EDT FRI SEP 28 2012
.SYNOPSIS...
A COLD FRONT WILL SAG SLOWLY SOUTH INTO THE AREA TONIGHT AND INTO
NORTH CAROLINA BY EARLY SATURDAY. THE FRONT WILL STALL OVER THE
CAROLINAS OVER THE WEEKEND INTO EARLY NEXT WEEK. LOW PRESSURE WILL
MOVE FROM THE GULF COAST INTO THE CAROLINAS ON TUESDAY AND
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT FRIDAY...
WAVE/VORT MOVING INTO SOUTHERN WVA ATTM THE MAIN PLAYER THIS
MORNING WITH BANDS OF SHRA/TSRA EXTENDING FROM AROUND THE SMALL
COMMA HEAD SOUTH INTO SW VA PER LATEST RADAR TRENDS. LATEST
GUIDANCE TAKES THIS IMPULSE NE ALONG THE FRONT INTO NORTH/CENTRAL
VA AND GRADUALLY DAMPENS IT THIS AFTERNOON AS THE SURFACE BOUNDARY
SAGS IN BY LATE IN THE DAY. EXPECT MUCH OF THE DEEPER CONVECTION
TO THE WEST TO WEAKEN PUSHING OUT EAST ACROSS THE MOUNTAINS GIVEN
LACK OF EARLY INSTABILITY BUT MAY BE ENOUGH SHRA/CLOUDS TO INHIBIT
HEATING THIS AFTERNOON. EXCEPTIONS LIKELY OVER THE FAR SOUTH AND
EAST WHERE DOWNSLOPING SEEN OFF MORNING RAOBS SHOULD ALLOW FOR
MORE BREAKS. HAVE ALREADY UPDATED TO BUMP POPS TO LIKELY A BIT
SOONER FAR WEST WHILE TRIMMING OUT EAST WHERE WILL STILL BE A FEW
HOURS PUSHING ANY SHRA OVER THE BLUE RIDGE. LEFT OVERALL LIKELY
POPS FOR MOST AREAS LATER IN THE AFTERNOON WHEN COMBO OF
WAVE/FRONT AND SOME HEATING SHOULD ALLOW FOR MORE WIDESPREAD SHRA
ACROSS THE CWA. TEMPS TRICKY AS EXPECT LITTLE IN THE WAY OF RISES
NW EARLY ON WHILE SEEING SOME SUN PIEDMONT AND FAR SOUTH.
THEREFORE BUMPED DOWN HIGHS IN THE WEST AND NORTH A FEW DEGREES
WHILE LEAVING THE EAST MOSTLY IN THE LOW 80S.
PREVIOUS DISCUSSION AS OF 420 AM EDT FRIDAY...
COLD FRONT TRAILS FROM LOW IN WESTERN PENNSYLVANIA TO ANOTHER LOW
IN WESTERN KENTUCKY. WATER VAPOR LOOP SHOWS A WELL DEFINED SHORT
WAVE ASSOCIATED WITH THE KENTUCKY LOW. THIS FEATURE WILL TRACK
EAST TODAY...REACHING THE FORECAST AREA THIS AFTERNOON. EXPECT THE
FRONT TO REMAIN ALONG A DC TO WESTERN KENTUCKY LINE THROUGH THE
DAY WITH A SLIGHT PUSH TO THE SOUTH TONIGHT AFTER THE LOW GOES BY.
SIMILAR TO THE PAST COUPLE OF DAYS EXPECT CLUSTERS OF SHOWERS AND
THUNDERSTORMS ALONG THE BOUNDARY TODAY AND TONIGHT. RADAR WAS
SHOWING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THE
WARM...MOIST AIR MASS AHEAD OF THE FRONT. LATEST RUC AND LOCAL WRF
DATA KEPT A MAJORITY OF THE SHOWERS AND THUNDERSTORMS IN THE
WESTERN COUNTY WARNING AREA THIS MORNING THEN MOVES A LINE OF
THUNDERSTORMS ACROSS THE FORECAST AREA BETWEEN 19Z/3PM AND
01Z/9PM. HAVE ALIGNED PROBABILITY OF PRECIPITATION TO FOLLOW THIS
TIMING AND PLACEMENT.
ONCE THE STORMS EXIT THE AREA THIS EVENING...THE CHANCE OF
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES OVERNIGHT WITH THE
FRONT ENTERING THE NORTHERN AND CENTRAL COUNTY WARNING AREA. CLOUD
COVER WILL GREATLY INFLUENCE THE INSTABILITY TODAY AND THE
LOCATIONS WITH THE HIGHEST POTENTIAL OF STRONG TO SEVERE STORMS.
WITH CLOUDS ALREADY SPREADING INTO THE WESTERN COUNTY WARNING
AREA...APPEARS THE BETTER THREAT FOR ANY SEVERE STORMS WILL BE IN
THE FOOTHILLS AND PIEDMONT WERE THERE WILL BE MORE HEATING AND
BETTER LAPSE RATES. WILL HIGHLIGHT THE SEVERE THREAT FOR THIS
REGION IN THE HAZARDOUS WEATHER OUTLOOK.
WITH THE FOOTHILLS AND PIEDMONT GETTING MORE SUN THIS MORNING HAVE
USE THE WARMER GUIDANCE AS A BASIS FOR AFTERNOON HIGH
TEMPERATURES. CLOUDS WILL KEEP HIGHS SLIGHTLY COOLER IN THE WEST.
WILL ALSO KEEP MINIMUM TEMPERATURES TONIGHT ON THE MILD
SIDE...WITH MUCH OF THE FORECAST AREA STILL ON THE WARM SIDE OF
THE FRONT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
AN UPPER LEVEL CLOSED OFF LOW WILL TRACK SOUTH FROM ONTARIO ON
SATURDAY TO NORTHWEST PENNSYLVANIA SUNDAY. THIS LOW WILL THEN TRACK
NORTHEAST OVER NEW YORK SUNDAY NIGHT. THIS LOW WILL MAINLY INFLUENCE
THE AREAS WEATHER BY KEEPING TEMPERATURES NEAR NORMAL ON SATURDAY
AND BELOW NORMAL SUNDAY. CAN NOT RULE OUT A STRAY MOUNTAIN SHOWERS AS
SHORT WAVES PIVOT AROUND THE LOW AND ACROSS THE APPALACHIANS.
MODELS ARE PAINTING SHOWERS ACROSS RNK SOUTH IN THE MORNING...THEN
IN THE PIEDMONT DURING THE AFTERNOON. AT FIRST...I DISREGARDED THESE
SHOWERS AS THE FRONT IS WELL SOUTH OF THE AREA AND THE SURFACE TO
LOW LEVEL FLOW IS NORTHERLY. IN FURTHER DISSECTING THE MODELS...THERE
IS AN 85H THETA-E BOUNDARY ALONG THE BLUE RIDGE FOR MUCH OF THE DAY.
FURTHERMORE...MID AND UPPER LEVEL JET STRUCTURE WOULD PROMOTE
SHOWERS TO FORM...ESPECIALLY IF LOW LEVEL MOISTURE IS SIGNIFICANT
ENOUGH. SO I AM CONVINCED SHOWERS WILL DEVELOP ACROSS THE SOUTH AND
EAST ON SATURDAY. HOWEVER...THINKING MODELS ARE OVER DONE ON
RAINFALL AMOUNTS WITH SOME DRIER AIR WORKING IN FROM THE NORTH.
THESE SHOWERS SHOULD FADE OR MOVE EAST OF THE AREA OVERNIGHT.
NEIGHBORING OFFICES IN THE EAST HAVE LOW CHANCE POPS FOR SUNDAY.
CONSIDERING THE FLIP-FLOP NATURE OF THE MODELS LATELY AND FORECAST
COLLABORATION...WILL ALSO HAVE LOW CHANCE POPS ACROSS THE PIEDMONT
SUNDAY. ANY SHOWERS WILL BE BRIEF AND THEREFORE LOOKING AT MORE OF A
DRY DAY. BY MONDAY MORNING...THE UPPER LEVEL LOW WILL TRACK TO THE
NORTHEAST AND HIGH PRESSURE FILLS IN BEHIND IT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
GFS IS DEFINITELY TRENDING TOWARD AN ECMWF SOLUTION NOW WITH MUCH
LESS AMPLITUDE WITH THE 500MB SHORT WAVE RIDING THROUGH THE UPPER
MIDWEST ON TUESDAY. PATTERN WILL ESSENTIALLY EVOLVE FROM A DEEP TROF
IN THE EAST ON SUNDAY TO A SPLIT FLOW REGIME BY MIDWEEK. HIGH
PRESSURE IS NOW PROGGED TO SET UP SHOP OFF THE COAST AND THIS WILL
BRING DEEP MOIST SLY FLOW INTO OUR AREA. ONE SURGE OF MOISTURE WILL
ARRIVE WITH A SHORT WAVE ON TUESDAY AND AGAIN ON THURSDAY WITH A BIT
OF A BREAK ON WEDNESDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1245 PM EDT FRIDAY...
INITIAL BATCH OF SHOWERS AND ISOLATED STORMS NOW PUSHING OUT TO
EAST OF THE BLUE RIDGE WITH GUSTY WINDS ASSOCIATED WITH THE
LEADING EDGE OF THE CONVECTION. THIS WILL CONTINUE TO BRING
PERIODS OF IFR/MVFR AT KLWB AND PERHAPS KLYH THRU 19Z/3 PM.
ADDITIONAL SHOWERS AND STORMS ARE EXPECTED TO DEVELOP ACROSS THE
EAST WITH SOME OF THIS COVERAGE LIKELY AFFECTING KDAN THIS
AFTERNOON. EXPECTING TO REMAIN VFR AT ALL OTHER SITES AS THE
REGION BRIEFLY SLIDES INTO A BREAK BETWEEN THE CURRENT WAVE AND
THE NEXT UPSTREAM IMPULSE OVER KY.
THIS NEXT WAVE WILL COMBINE WITH THE FRONT SINKING SOUTH TO BRING
ANOTHER ROUND OF SHRA/TSRA FROM WEST TO EAST LATE THIS AFTERNOON
INTO THIS EVENING. FRONT LOOKS TO SLIP THROUGH THE NW LATER
TONIGHT...AND PERHAPS REACHING THE VA/NC BORDER OVERNIGHT. LATEST
NAM QUITE BULLISH ON BRINGING IN IFR/LIFR FOG AND LOW CIGS BEHIND
THE EXITING SHRA THIS EVENING BUT LOOKS OVERDONE OUTSIDE OF SE WVA
WHERE HIGHER CONFIDENCE OF SEEING AT LEAST MVFR CIGS/VSBYS
TONIGHT. ELSW TRENDED CLOSER TO THE LATEST LAMP DATA WITH A COMP
TOWARD THE NAM LATE WHEN A PERIOD OF MVFR/IFR VSBYS/CIGS POSSIBLE
AT MOST LOCATIONS EXCLUDING KROA.
THE DEEPER MOISTURE ALONG THE FRONT GETS PUSHED INTO THE
CAROLINAS ON SATURDAY AND SUNDAY. HOWEVER WITH ANOTHER WAVE
RIPPLING ALONG THE FRONT TO THE SOUTH WILL LIKELY BE HARD TO ERODE
LOW CIGS OVER THE SOUTH UNTIL SAT AFTERNOON. SOME -RA ALSO
POSSIBLE MAINLY AROUND KDAN IN THE MORNING BUT WONT INCLUDE
MENTION ATTM WHILE KEEPING VFR CIGS MOST SPOTS UNTIL MID MORNING
AND INTO THE AFTERNOON AT KDAN. SHOULD FINALLY SEE CLOUDS AND A
RETURN TO VFR SAT NIGHT INTO SUNDAY WITH ONLY SOME RESIDUAL CLOUDS
AROUND OUT EAST SAT EVENING FOR NOW. LOW PRESSURE MOVING UP FROM
THE GULF WILL LIKELY BRING RAIN AND SUB VFR CONDITIONS LATER
MONDAY INTO TUESDAY FOLLOWED BY IMPROVING WEATHER TUESDAY.
&&
.EQUIPMENT...
THE KFCX DOPPLER RADAR WHICH SERVES THE ROANOKE AND SURROUNDING
AREA IS TENTATIVELY SCHEDULED TO BE TAKEN DOWN FOR SEVERAL DAYS
BEGINNING MONDAY OCTOBER 1ST FOR ITS UPGRADE TO DUAL POLARIZATION
TECHNOLOGY. NEIGHBORING DOPPLER RADARS AT STERLING VA (KLWX)...
WAKEFIELD VA (KAKQ)...RALEIGH NC (KRAX)...GREENVILLE-SPARTANBURG
SC (KGSP)...MORRISTOWN TN (KMRX)...AND CHARLESTON WV (KRLX) WILL
CONTINUE TO PROVIDE COVERAGE OVER PARTS OF THE KFCX AREA DURING
THE INSTALLATION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...AMS/JH
SHORT TERM...RCS
LONG TERM...MBS
AVIATION...AMS/JH/KM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1006 AM EDT FRI SEP 28 2012
.SYNOPSIS...
A COLD FRONT FROM WESTERN PENNSYLVANIA TO WESTERN KENTUCKY WILL
MOVE SLOWLY SOUTH THIS AFTERNOON THROUGH SATURDAY. THE FRONT WILL
STALL OVER THE CAROLINAS ON SUNDAY AND MONDAY. LOW PRESSURE WILL
MOVE FROM THE GULF COAST INTO THE CAROLINAS ON TUESDAY AND
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT FRIDAY...
WAVE/VORT MOVING INTO SOUTHERN WVA ATTM THE MAIN PLAYER THIS
MORNING WITH BANDS OF SHRA/TSRA EXTENDING FROM AROUND THE SMALL
COMMA HEAD SOUTH INTO SW VA PER LATEST RADAR TRENDS. LATEST
GUIDANCE TAKES THIS IMPULSE NE ALONG THE FRONT INTO NORTH/CENTRAL
VA AND GRADUALLY DAMPENS IT THIS AFTERNOON AS THE SURFACE BOUNDARY
SAGS IN BY LATE IN THE DAY. EXPECT MUCH OF THE DEEPER CONVECTION
TO THE WEST TO WEAKEN PUSHING OUT EAST ACROSS THE MOUNTAINS GIVEN
LACK OF EARLY INSTABILITY BUT MAY BE ENOUGH SHRA/CLOUDS TO INHIBIT
HEATING THIS AFTERNOON. EXCEPTIONS LIKELY OVER THE FAR SOUTH AND
EAST WHERE DOWNSLOPING SEEN OFF MORNING RAOBS SHOULD ALLOW FOR
MORE BREAKS. HAVE ALREADY UPDATED TO BUMP POPS TO LIKELY A BIT
SOONER FAR WEST WHILE TRIMMING OUT EAST WHERE WILL STILL BE A FEW
HOURS PUSHING ANY SHRA OVER THE BLUE RIDGE. LEFT OVERALL LIKELY
POPS FOR MOST AREAS LATER IN THE AFTERNOON WHEN COMBO OF
WAVE/FRONT AND SOME HEATING SHOULD ALLOW FOR MORE WIDESPREAD SHRA
ACROSS THE CWA. TEMPS TRICKY AS EXPECT LITTLE IN THE WAY OF RISES
NW EARLY ON WHILE SEEING SOME SUN PIEDMONT AND FAR SOUTH.
THEREFORE BUMPED DOWN HIGHS IN THE WEST AND NORTH A FEW DEGREES
WHILE LEAVING THE EAST MOSTLY IN THE LOW 80S.
PREVIOUS DISCUSSION AS OF 420 AM EDT FRIDAY...
COLD FRONT TRAILS FROM LOW IN WESTERN PENNSYLVANIA TO ANOTHER LOW
IN WESTERN KENTUCKY. WATER VAPOR LOOP SHOWS A WELL DEFINED SHORT
WAVE ASSOCIATED WITH THE KENTUCKY LOW. THIS FEATURE WILL TRACK
EAST TODAY...REACHING THE FORECAST AREA THIS AFTERNOON. EXPECT THE
FRONT TO REMAIN ALONG A DC TO WESTERN KENTUCKY LINE THROUGH THE
DAY WITH A SLIGHT PUSH TO THE SOUTH TONIGHT AFTER THE LOW GOES BY.
SIMILAR TO THE PAST COUPLE OF DAYS EXPECT CLUSTERS OF SHOWERS AND
THUNDERSTORMS ALONG THE BOUNDARY TODAY AND TONIGHT. RADAR WAS
SHOWING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THE
WARM...MOIST AIR MASS AHEAD OF THE FRONT. LATEST RUC AND LOCAL WRF
DATA KEPT A MAJORITY OF THE SHOWERS AND THUNDERSTORMS IN THE
WESTERN COUNTY WARNING AREA THIS MORNING THEN MOVES A LINE OF
THUNDERSTORMS ACROSS THE FORECAST AREA BETWEEN 19Z/3PM AND
01Z/9PM. HAVE ALIGNED PROBABILITY OF PRECIPITATION TO FOLLOW THIS
TIMING AND PLACEMENT.
ONCE THE STORMS EXIT THE AREA THIS EVENING...THE CHANCE OF
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES OVERNIGHT WITH THE
FRONT ENTERING THE NORTHERN AND CENTRAL COUNTY WARNING AREA. CLOUD
COVER WILL GREATLY INFLUENCE THE INSTABILITY TODAY AND THE
LOCATIONS WITH THE HIGHEST POTENTIAL OF STRONG TO SEVERE STORMS.
WITH CLOUDS ALREADY SPREADING INTO THE WESTERN COUNTY WARNING
AREA...APPEARS THE BETTER THREAT FOR ANY SEVERE STORMS WILL BE IN
THE FOOTHILLS AND PIEDMONT WERE THERE WILL BE MORE HEATING AND
BETTER LAPSE RATES. WILL HIGHLIGHT THE SEVERE THREAT FOR THIS
REGION IN THE HAZARDOUS WEATHER OUTLOOK.
WITH THE FOOTHILLS AND PIEDMONT GETTING MORE SUN THIS MORNING HAVE
USE THE WARMER GUIDANCE AS A BASIS FOR AFTERNOON HIGH
TEMPERATURES. CLOUDS WILL KEEP HIGHS SLIGHTLY COOLER IN THE WEST.
WILL ALSO KEEP MINIMUM TEMPERATURES TONIGHT ON THE MILD
SIDE...WITH MUCH OF THE FORECAST AREA STILL ON THE WARM SIDE OF
THE FRONT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
AN UPPER LEVEL CLOSED OFF LOW WILL TRACK SOUTH FROM ONTARIO ON
SATURDAY TO NORTHWEST PENNSYLVANIA SUNDAY. THIS LOW WILL THEN TRACK
NORTHEAST OVER NEW YORK SUNDAY NIGHT. THIS LOW WILL MAINLY INFLUENCE
THE AREAS WEATHER BY KEEPING TEMPERATURES NEAR NORMAL ON SATURDAY
AND BELOW NORMAL SUNDAY. CAN NOT RULE OUT A STRAY MOUNTAIN SHOWERS AS
SHORT WAVES PIVOT AROUND THE LOW AND ACROSS THE APPALACHIANS.
MODELS ARE PAINTING SHOWERS ACROSS RNK SOUTH IN THE MORNING...THEN
IN THE PIEDMONT DURING THE AFTERNOON. AT FIRST...I DISREGARDED THESE
SHOWERS AS THE FRONT IS WELL SOUTH OF THE AREA AND THE SURFACE TO
LOW LEVEL FLOW IS NORTHERLY. IN FURTHER DISSECTING THE MODELS...THERE
IS AN 85H THETA-E BOUNDARY ALONG THE BLUE RIDGE FOR MUCH OF THE DAY.
FURTHERMORE...MID AND UPPER LEVEL JET STRUCTURE WOULD PROMOTE
SHOWERS TO FORM...ESPECIALLY IF LOW LEVEL MOISTURE IS SIGNIFICANT
ENOUGH. SO I AM CONVINCED SHOWERS WILL DEVELOP ACROSS THE SOUTH AND
EAST ON SATURDAY. HOWEVER...THINKING MODELS ARE OVER DONE ON
RAINFALL AMOUNTS WITH SOME DRIER AIR WORKING IN FROM THE NORTH.
THESE SHOWERS SHOULD FADE OR MOVE EAST OF THE AREA OVERNIGHT.
NEIGHBORING OFFICES IN THE EAST HAVE LOW CHANCE POPS FOR SUNDAY.
CONSIDERING THE FLIP-FLOP NATURE OF THE MODELS LATELY AND FORECAST
COLLABORATION...WILL ALSO HAVE LOW CHANCE POPS ACROSS THE PIEDMONT
SUNDAY. ANY SHOWERS WILL BE BRIEF AND THEREFORE LOOKING AT MORE OF A
DRY DAY. BY MONDAY MORNING...THE UPPER LEVEL LOW WILL TRACK TO THE
NORTHEAST AND HIGH PRESSURE FILLS IN BEHIND IT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
GFS IS DEFINITELY TRENDING TOWARD AN ECMWF SOLUTION NOW WITH MUCH
LESS AMPLITUDE WITH THE 500MB SHORT WAVE RIDING THROUGH THE UPPER
MIDWEST ON TUESDAY. PATTERN WILL ESSENTIALLY EVOLVE FROM A DEEP TROF
IN THE EAST ON SUNDAY TO A SPLIT FLOW REGIME BY MIDWEEK. HIGH
PRESSURE IS NOW PROGGED TO SET UP SHOP OFF THE COAST AND THIS WILL
BRING DEEP MOIST SLY FLOW INTO OUR AREA. ONE SURGE OF MOISTURE WILL
ARRIVE WITH A SHORT WAVE ON TUESDAY AND AGAIN ON THURSDAY WITH A BIT
OF A BREAK ON WEDNESDAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
AS OF 735 AM EDT FRIDAY...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL BECOME MORE
WIDESPREAD DURING THE MORNING. AT THE CURRENT SPEED AND DIRECTION
THE LINE OF STORMS IN CENTRAL KENTUCKY WILL REACH BLF AROUND
15Z/11AM AND ROA/BCB AROUND 16Z/NOON. HAVE VCSH IN THE LWB AND BCB
TAFS FOR THE SHOWERS AHEAD OF THESE STORMS.
HRRR...RUC AND LOCAL WRF SHOWED ANOTHER BATCH OF THUNDERSTORMS
CROSSING THROUGH THE FORECAST AREA BETWEEN 19Z/3PM AND 01Z/9PM.
THIS WILL BE AHEAD OF A COLD FRONT DRIFTING SLOWLY SOUTH INTO THE
REGION. MODERATE CONFIDENCE THAT BLF AND POSSIBLE LWB WILL HAVE
MVFR CEILINGS ON THE COOL SIDE OF THE FRONT LATE TONIGHT.
THE DEEPER MOISTURE GETS PUSHED INTO THE CAROLINAS ON SATURDAY AND
SUNDAY RESULTING IN VFR CONDITIONS AND A LOWER PROBABILITY OF
PRECIPITATION. THE CHANCE OF RAIN AND SUB VFR CONDITIONS RETURNS
BY TUESDAY.
&&
.EQUIPMENT...
THE KFCX DOPPLER RADAR WHICH SERVES THE ROANOKE AND SURROUNDING
AREA IS TENTATIVELY SCHEDULED TO BE TAKEN DOWN FOR SEVERAL DAYS
BEGINNING MONDAY OCTOBER 1ST FOR ITS UPGRADE TO DUAL POLARIZATION
TECHNOLOGY. NEIGHBORING DOPPLER RADARS AT STERLING VA (KLWX)...
WAKEFIELD VA (KAKQ)...RALEIGH NC (KRAX)...GREENVILLE-SPARTANBURG
SC (KGSP)...MORRISTOWN TN (KMRX)...AND CHARLESTON WV (KRLX) WILL
CONTINUE TO PROVIDE COVERAGE OVER PARTS OF THE KFCX AREA DURING
THE INSTALLATION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/JH
SHORT TERM...RCS
LONG TERM...MBS
AVIATION...AMS/KM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
743 AM EDT FRI SEP 28 2012
.SYNOPSIS...
A COLD FRONT FROM WESTERN PENNSYLVANIA TO WESTERN KENTUCKY WILL
MOVE SLOWLY SOUTH TONIGHT AND SATURDAY. THE FRONT WILL STALL OVER
THE CAROLINAS ON SUNDAY AND MONDAY. LOW PRESSURE WILL MOVE FROM
THE GULF COAST INTO THE CAROLINAS ON TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 420 AM EDT FRIDAY...
COLD FRONT TRAILS FROM LOW IN WESTERN PENNSYLVANIA TO ANOTHER LOW
IN WESTERN KENTUCKY. WATER VAPOR LOOP SHOWS A WELL DEFINED SHORT
WAVE ASSOCIATED WITH THE KENTUCKY LOW. THIS FEATURE WILL TRACK
EAST TODAY...REACHING THE FORECAST AREA THIS AFTERNOON. EXPECT THE
FRONT TO REMAIN ALONG A DC TO WESTERN KENTUCKY LINE THROUGH THE
DAY WITH A SLIGHT PUSH TO THE SOUTH TONIGHT AFTER THE LOW GOES BY.
SIMILAR TO THE PAST COUPLE OF DAYS EXPECT CLUSTERS OF SHOWERS AND
THUNDERSTORMS ALONG THE BOUNDARY TODAY AND TONIGHT. RADAR WAS
SHOWING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THE
WARM...MOIST AIR MASS AHEAD OF THE FRONT. LATEST RUC AND LOCAL WRF
DATA KEPT A MAJORITY OF THE SHOWERS AND THUNDERSTORMS IN THE
WESTERN COUNTY WARNING AREA THIS MORNING THEN MOVES A LINE OF
THUNDERSTORMS ACROSS THE FORECAST AREA BETWEEN 19Z/3PM AND
01Z/9PM. HAVE ALIGNED PROBABILITY OF PRECIPITATION TO FOLLOW THIS
TIMING AND PLACEMENT.
ONCE THE STORMS EXIT THE AREA THIS EVENING...THE CHANCE OF
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES OVERNIGHT WITH THE
FRONT ENTERING THE NORTHERN AND CENTRAL COUNTY WARNING AREA. CLOUD
COVER WILL GREATLY INFLUENCE THE INSTABILITY TODAY AND THE
LOCATIONS WITH THE HIGHEST POTENTIAL OF STRONG TO SEVERE STORMS.
WITH CLOUDS ALREADY SPREADING INTO THE WESTERN COUNTY WARNING
AREA...APPEARS THE BETTER THREAT FOR ANY SEVERE STORMS WILL BE IN
THE FOOTHILLS AND PIEDMONT WERE THERE WILL BE MORE HEATING AND
BETTER LAPSE RATES. WILL HIGHLIGHT THE SEVERE THREAT FOR THIS
REGION IN THE HAZARDOUS WEATHER OUTLOOK.
WITH THE FOOTHILLS AND PIEDMONT GETTING MORE SUN THIS MORNING HAVE
USE THE WARMER GUIDANCE AS A BASIS FOR AFTERNOON HIGH
TEMPERATURES. CLOUDS WILL KEEP HIGHS SLIGHTLY COOLER IN THE WEST.
WILL ALSO KEEP MINIMUM TEMPERATURES TONIGHT ON THE MILD
SIDE...WITH MUCH OF THE FORECAST AREA STILL ON THE WARM SIDE OF
THE FRONT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
AN UPPER LEVEL CLOSED OFF LOW WILL TRACK SOUTH FROM ONTARIO ON
SATURDAY TO NORTHWEST PENNSYLVANIA SUNDAY. THIS LOW WILL THEN TRACK
NORTHEAST OVER NEW YORK SUNDAY NIGHT. THIS LOW WILL MAINLY INFLUENCE
THE AREAS WEATHER BY KEEPING TEMPERATURES NEAR NORMAL ON SATURDAY
AND BELOW NORMAL SUNDAY. CAN NOT RULE OUT A STRAY MOUNTAIN SHOWERS AS
SHORT WAVES PIVOT AROUND THE LOW AND ACROSS THE APPALACHIANS.
MODELS ARE PAINTING SHOWERS ACROSS RNK SOUTH IN THE MORNING...THEN
IN THE PIEDMONT DURING THE AFTERNOON. AT FIRST...I DISREGARDED THESE
SHOWERS AS THE FRONT IS WELL SOUTH OF THE AREA AND THE SURFACE TO
LOW LEVEL FLOW IS NORTHERLY. IN FURTHER DISSECTING THE MODELS...THERE
IS AN 85H THETA-E BOUNDARY ALONG THE BLUE RIDGE FOR MUCH OF THE DAY.
FURTHERMORE...MID AND UPPER LEVEL JET STRUCTURE WOULD PROMOTE
SHOWERS TO FORM...ESPECIALLY IF LOW LEVEL MOISTURE IS SIGNIFICANT
ENOUGH. SO I AM CONVINCED SHOWERS WILL DEVELOP ACROSS THE SOUTH AND
EAST ON SATURDAY. HOWEVER...THINKING MODELS ARE OVER DONE ON
RAINFALL AMOUNTS WITH SOME DRIER AIR WORKING IN FROM THE NORTH.
THESE SHOWERS SHOULD FADE OR MOVE EAST OF THE AREA OVERNIGHT.
NEIGHBORING OFFICES IN THE EAST HAVE LOW CHANCE POPS FOR SUNDAY.
CONSIDERING THE FLIP-FLOP NATURE OF THE MODELS LATELY AND FORECAST
COLLABORATION...WILL ALSO HAVE LOW CHANCE POPS ACROSS THE PIEDMONT
SUNDAY. ANY SHOWERS WILL BE BRIEF AND THEREFORE LOOKING AT MORE OF A
DRY DAY. BY MONDAY MORNING...THE UPPER LEVEL LOW WILL TRACK TO THE
NORTHEAST AND HIGH PRESSURE FILLS IN BEHIND IT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
GFS IS DEFINITELY TRENDING TOWARD AN ECMWF SOLUTION NOW WITH MUCH
LESS AMPLITUDE WITH THE 500MB SHORT WAVE RIDING THROUGH THE UPPER
MIDWEST ON TUESDAY. PATTERN WILL ESSENTIALLY EVOLVE FROM A DEEP TROF
IN THE EAST ON SUNDAY TO A SPLIT FLOW REGIME BY MIDWEEK. HIGH
PRESSURE IS NOW PROGGED TO SET UP SHOP OFF THE COAST AND THIS WILL
BRING DEEP MOIST SLY FLOW INTO OUR AREA. ONE SURGE OF MOISTURE WILL
ARRIVE WITH A SHORT WAVE ON TUESDAY AND AGAIN ON THURSDAY WITH A BIT
OF A BREAK ON WEDNESDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 735 AM EDT FRIDAY...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL BECOME MORE
WIDESPREAD DURING THE MORNING. AT THE CURRENT SPEED AND DIRECTION
THE LINE OF STORMS IN CENTRAL KENTUCKY WILL REACH BLF AROUND
15Z/11AM AND ROA/BCB AROUND 16Z/NOON. HAVE VCSH IN THE LWB AND BCB
TAFS FOR THE SHOWERS AHEAD OF THESE STORMS.
HRRR...RUC AND LOCAL WRF SHOWED ANOTHER BATCH OF THUNDERSTORMS
CROSSING THROUGH THE FORECAST AREA BETWEEN 19Z/3PM AND 01Z/9PM.
THIS WILL BE AHEAD OF A COLD FRONT DRIFTING SLOWLY SOUTH INTO THE
REGION. MODERATE CONFIDENCE THAT BLF AND POSSIBLE LWB WILL HAVE
MVFR CEILINGS ON THE COOL SIDE OF THE FRONT LATE TONIGHT.
THE DEEPER MOISTURE GETS PUSHED INTO THE CAROLINAS ON SATURDAY AND
SUNDAY RESULTING IN VFR CONDITIONS AND A LOWER PROBABILITY OF
PRECIPITATION. THE CHANCE OF RAIN AND SUB VFR CONDITIONS RETURNS
BY TUESDAY.
&&
.EQUIPMENT...
THE KFCX DOPPLER RADAR WHICH SERVES THE ROANOKE AND SURROUNDING
AREA IS TENTATIVELY SCHEDULED TO BE TAKEN DOWN FOR SEVERAL DAYS
BEGINNING MONDAY OCTOBER 1ST FOR ITS UPGRADE TO DUAL POLARIZATION
TECHNOLOGY. NEIGHBORING DOPPLER RADARS AT STERLING VA (KLWX)...
WAKEFIELD VA (KAKQ)...RALEIGH NC (KRAX)...GREENVILLE-SPARTANBURG
SC (KGSP)...MORRISTOWN TN (KMRX)...AND CHARLESTON WV (KRLX) WILL
CONTINUE TO PROVIDE COVERAGE OVER PARTS OF THE KFCX AREA DURING
THE INSTALLATION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...MBS
AVIATION...AMS/KM
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
438 AM EDT FRI SEP 28 2012
.SYNOPSIS...
A COLD FRONT FROM WESTERN PENNSYLVANIA TO WESTERN KENTUCKY WILL
MOVE SLOWLY SOUTH TONIGHT AND SATURDAY. THE FRONT WILL STALL OVER
THE CAROLINAS ON SUNDAY AND MONDAY. LOW PRESSURE WILL MOVE FROM
THE GULF COAST INTO THE CAROLINAS ON TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 420 AM EDT FRIDAY...
COLD FRONT TRAILS FROM LOW IN WESTERN PENNSYLVANIA TO ANOTHER LOW
IN WESTERN KENTUCKY. WATER VAPOR LOOP SHOWS A WELL DEFINED SHORT
WAVE ASSOCIATED WITH THE KENTUCKY LOW. THIS FEATURE WILL TRACK
EAST TODAY...REACHING THE FORECAST AREA THIS AFTERNOON. EXPECT THE
FRONT TO REMAIN ALONG A DC TO WESTERN KENTUCKY LINE THROUGH THE
DAY WITH A SLIGHT PUSH TO THE SOUTH TONIGHT AFTER THE LOW GOES BY.
SIMILAR TO THE PAST COUPLE OF DAYS EXPECT CLUSTERS OF SHOWERS AND
THUNDERSTORMS ALONG THE BOUNDARY TODAY AND TONIGHT. RADAR WAS
SHOWING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IN THE
WARM...MOIST AIR MASS AHEAD OF THE FRONT. LATEST RUC AND LOCAL WRF
DATA KEPT A MAJORITY OF THE SHOWERS AND THUNDERSTORMS IN THE
WESTERN COUNTY WARNING AREA THIS MORNING THEN MOVES A LINE OF
THUNDERSTORMS ACROSS THE FORECAST AREA BETWEEN 19Z/3PM AND
01Z/9PM. HAVE ALIGNED PROBABILITY OF PRECIPITATION TO FOLLOW THIS
TIMING AND PLACEMENT.
ONCE THE STORMS EXIT THE AREA THIS EVENING...THE CHANCE OF
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES OVERNIGHT WITH THE
FRONT ENTERING THE NORTHERN AND CENTRAL COUNTY WARNING AREA. CLOUD
COVER WILL GREATLY INFLUENCE THE INSTABILITY TODAY AND THE
LOCATIONS WITH THE HIGHEST POTENTIAL OF STRONG TO SEVERE STORMS.
WITH CLOUDS ALREADY SPREADING INTO THE WESTERN COUNTY WARNING
AREA...APPEARS THE BETTER THREAT FOR ANY SEVERE STORMS WILL BE IN
THE FOOTHILLS AND PIEDMONT WERE THERE WILL BE MORE HEATING AND
BETTER LAPSE RATES. WILL HIGHLIGHT THE SEVERE THREAT FOR THIS
REGION IN THE HAZARDOUS WEATHER OUTLOOK.
WITH THE FOOTHILLS AND PIEDMONT GETTING MORE SUN THIS MORNING HAVE
USE THE WARMER GUIDANCE AS A BASIS FOR AFTERNOON HIGH
TEMPERATURES. CLOUDS WILL KEEP HIGHS SLIGHTLY COOLER IN THE WEST.
WILL ALSO KEEP MINIMUM TEMPERATURES TONIGHT ON THE MILD
SIDE...WITH MUCH OF THE FORECAST AREA STILL ON THE WARM SIDE OF
THE FRONT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
AN UPPER LEVEL CLOSED OFF LOW WILL TRACK SOUTH FROM ONTARIO ON
SATURDAY TO NORTHWEST PENNSYLVANIA SUNDAY. THIS LOW WILL THEN TRACK
NORTHEAST OVER NEW YORK SUNDAY NIGHT. THIS LOW WILL MAINLY INFLUENCE
THE AREAS WEATHER BY KEEPING TEMPERATURES NEAR NORMAL ON SATURDAY
AND BELOW NORMAL SUNDAY. CAN NOT RULE OUT A STRAY MOUNTAIN SHOWERS AS
SHORT WAVES PIVOT AROUND THE LOW AND ACROSS THE APPALACHIANS.
MODELS ARE PAINTING SHOWERS ACROSS RNK SOUTH IN THE MORNING...THEN
IN THE PIEDMONT DURING THE AFTERNOON. AT FIRST...I DISREGARDED THESE
SHOWERS AS THE FRONT IS WELL SOUTH OF THE AREA AND THE SURFACE TO
LOW LEVEL FLOW IS NORTHERLY. IN FURTHER DISSECTING THE MODELS...THERE
IS AN 85H THETA-E BOUNDARY ALONG THE BLUE RIDGE FOR MUCH OF THE DAY.
FURTHERMORE...MID AND UPPER LEVEL JET STRUCTURE WOULD PROMOTE
SHOWERS TO FORM...ESPECIALLY IF LOW LEVEL MOISTURE IS SIGNIFICANT
ENOUGH. SO I AM CONVINCED SHOWERS WILL DEVELOP ACROSS THE SOUTH AND
EAST ON SATURDAY. HOWEVER...THINKING MODELS ARE OVER DONE ON
RAINFALL AMOUNTS WITH SOME DRIER AIR WORKING IN FROM THE NORTH.
THESE SHOWERS SHOULD FADE OR MOVE EAST OF THE AREA OVERNIGHT.
NEIGHBORING OFFICES IN THE EAST HAVE LOW CHANCE POPS FOR SUNDAY.
CONSIDERING THE FLIP-FLOP NATURE OF THE MODELS LATELY AND FORECAST
COLLABORATION...WILL ALSO HAVE LOW CHANCE POPS ACROSS THE PIEDMONT
SUNDAY. ANY SHOWERS WILL BE BRIEF AND THEREFORE LOOKING AT MORE OF A
DRY DAY. BY MONDAY MORNING...THE UPPER LEVEL LOW WILL TRACK TO THE
NORTHEAST AND HIGH PRESSURE FILLS IN BEHIND IT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM EDT THURSDAY...
GFS IS DEFINITELY TRENDING TOWARD AN ECMWF SOLUTION NOW WITH MUCH
LESS AMPLITUDE WITH THE 500MB SHORT WAVE RIDING THROUGH THE UPPER
MIDWEST ON TUESDAY. PATTERN WILL ESSENTIALLY EVOLVE FROM A DEEP TROF
IN THE EAST ON SUNDAY TO A SPLIT FLOW REGIME BY MIDWEEK. HIGH
PRESSURE IS NOW PROGGED TO SET UP SHOP OFF THE COAST AND THIS WILL
BRING DEEP MOIST SLY FLOW INTO OUR AREA. ONE SURGE OF MOISTURE WILL
ARRIVE WITH A SHORT WAVE ON TUESDAY AND AGAIN ON THURSDAY WITH A BIT
OF A BREAK ON WEDNESDAY.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 135 AM EDT FRIDAY...
SCATTERED SHOWERS EXTENDED FROM SOUTHERN PENNSYLVANIA TO EASTERN
KENTUCKY JUST AHEAD OF A SLOW MOVING COLD FRONT. THESE SHOWERS WERE
DISSIPATING AS THEY MOVED EAST BUT STILL ENOUGH COVERAGE TO ADD
VCSH TO LWB EARLY THIS MORNING.
BY MID MORNING...THE LOW PRESSURE SYSTEM WILL PROGRESS EAST INTO
THE LOWER NEW ENGLAND STATES...DRAGGING THE COLD FRONT FURTHER
SOUTH ACROSS OUR AREA. ADDITIONAL SHOWER AND ISOLATED THUNDERSTORM
ACTIVITY WILL DEVELOP BY THIS AFTERNOON. ANY STRONGER STORMS MAY
HAVE MVFR CONDITIONS.
THE DEEPER MOISTURE GETS PUSHED INTO THE CAROLINAS ON SATURDAY AND
SUNDAY RESULTING IN VFR CONDITIONS AND A LOWER PROBABILITY OF
PRECIPITATION. THE CHANCE OF RAIN RETURNS TO THE REGION ON MONDAY
AND TUESDAY.
&&
.EQUIPMENT...
THE KFCX DOPPLER RADAR WHICH SERVES THE ROANOKE AND SURROUNDING
AREA IS TENTATIVELY SCHEDULED TO BE TAKEN DOWN FOR SEVERAL DAYS
BEGINNING MONDAY OCTOBER 1ST FOR ITS UPGRADE TO DUAL POLARIZATION
TECHNOLOGY. NEIGHBORING DOPPLER RADARS AT STERLING VA (KLWX)...
WAKEFIELD VA (KAKQ)...RALEIGH NC (KRAX)...GREENVILLE-SPARTANBURG
SC (KGSP)...MORRISTOWN TN (KMRX)...AND CHARLESTON WV (KRLX) WILL
CONTINUE TO PROVIDE COVERAGE OVER PARTS OF THE KFCX AREA DURING
THE INSTALLATION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...MBS
AVIATION...AMS/KM
EQUIPMENT...NF
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
643 PM CDT SAT SEP 29 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
311 PM CDT SAT SEP 29 2012
MAIN FORECAST CONCERNS ARE ON VALLEY FOG POTENTIAL TONIGHT INTO
SUNDAY MORNING. FOCUS THEN TURNS TO RAIN CHANCES ON MONDAY.
LATEST WATER VAPOR IMAGERY SHOWED A HIGH AMPLITUDE UPPER RIDGE
BUILDING INTO THE UPPER MISSISSIPPI RIVER VALLEY. AN ELONGATED UPPER
TROUGH EXTENDED FROM QUEBEC SOUTHWEST INTO THE EASTERN GREAT LAKES.
A SPLIT FLOW TYPE PATTERN IS EVIDENT ACROSS THE CONUS...WITH A
SOUTHERN JET ACROSS THE SOUTHERN UNITED STATES AND A NORTHERN STREAM
JET OVER SOUTHERN/CENTRAL PORTIONS OF CANADA. SURFACE ANALYSIS
SHOWED TWO AREAS OF HIGH PRESSURE. THE FIRST EXTENDED FROM HUDSONS
BAY SOUTHWEST OVER LAKE SUPERIOR. THE SECOND HIGH WAS LOCATED OVER
THE IOWA/NEBRASKA BORDER. THESE TWO HIGHS WERE MERGING TOGETHER AND
PROVIDING ABUNDANT SUNSHINE ACROSS THE FORECAST AREA.
THE HIGH WILL REMAIN IN CONTROL ACROSS THE FORECAST AREA TONIGHT
PROVIDING CLEAR SKIES AND CALM TO LIGHT WINDS. FORECAST SOUNDINGS
SHOW THE POTENTIAL FOR VALLEY FOG ALONG THE MISSISSIPPI RIVER
VALLEY. THE MAIN LIMITING FACTOR APPEARS TO BE A LACK OF
SUFFICIENT MOISTURE IN THE LOWER LEVELS...THANKS TO DEEP MIXING THIS
AFTERNOON AND PLANT NO LONGER PROVIDING SUFFICIENT
EVAPOTRANSPIRATION TO ADD MOISTURE TO THE BOUNDARY LAYER.
HOWEVER...WITH THE HIGH OVERHEAD AND THE LONGER NIGHTS THIS TIME
OF YEAR...FEEL THAT WE HAVE A BETTER CHANCE OF SEEING THE FOG
VERSUS THE PREVIOUS TWO NIGHTS. OFF OF THE NAM...WINDS FROM THE
SURFACE THROUGH 500 FEET ARE VERY LIGHT THEN INCREASE SLIGHTLY
THROUGH 1200 FT. THIS INCREASE IN WINDS IN THE LOWER LEVELS IS
TYPICAL IN THE NAM AND THINKING THAT THIS IS OVERDONE. THE SURFACE
TEMPERATURE AND DEWPOINT SPREAD FINALLY GO TO ZERO IN THE 11 TO
12Z TIMEFRAME. THERE ARE ENOUGH SIGNALS TO SUPPORT THE FOG SO WILL
BE ADDING PATCHY FOG TO THE FORECAST ALONG THE MISSISSIPPI AND
WISCONSIN RIVER VALLEYS. PLAN ON LOW TEMPERATURES RANGING FROM THE
LOWER TO MID 30S OVER NORTHERN WISCONSIN TO THE MID 40S ACROSS
NORTHEAST IOWA.
THE UPPER RIDGE WILL MAKE VERY LITTLE PROGRESS EAST ON SUNDAY AS THE
UPPER TROUGH OVER QUEBEC DRIFTS SOUTHWEST AND CLOSES INTO A BROAD
UPPER LOW OVER EASTERN LAKE HURON. THIS WILL KEEP THE FORECAST AREA
UNDER THE RIDGE THROUGH SUNDAY NIGHT PROVIDING PLEASANT WEATHER.
SLIGHTLY COOLER AIR WILL EDGE INTO LOCATIONS ALONG AND EAST OF THE
MISSISSIPPI RIVER AS THE SLIDES OVER LAKE HURON. 925 MB TEMPERATURES
TO FROM 14Z ON SATURDAY ACROSS NORTH CENTRAL WISCONSIN...TO AROUND
12C BY SUNDAY AFTERNOON. PLAN ON HIGHS RANGING FROM THE MID TO UPPER
60S ACROSS NORTHERN WISCONSIN TO THE LOWER TO MID 70S OVER NORTHEAST
IOWA. THE RIDGE WILL BREAK DOWN SUNDAY NIGHT INTO MONDAY AS A TROUGH
AND COLD FRONT DIVE SOUTHEAST OUT OF SOUTHERN SASKATCHEWAN AND
MANITOBA. MEANWHILE...THE UPPER LOW OVER LAKE HURON WILL LIFT
NORTHEAST INTO NEW ENGLAND LATE SUNDAY AFTERNOON THROUGH SUNDAY
NIGHT. THE COLD FRONT IS EXPECTED TO MOVE ACROSS THE REGION DURING
THE DAY ON MONDAY BRINGING SLIGHT CHANCES FOR RAIN TO THE AREA.
FORECAST MODELS ARE NOT PRODUCING MUCH PRECIPITATION AS THE FRONT
MOVES THROUGH. FORCING SHOULD BE SUFFICIENT TO PRODUCE LIGHT
RAIN...WITH 500-300 MB POTENTIAL VORTICITY ADVECTION OF 15 PVU/S AND
WEAK FRONTOGENESIS IN THE 1000 TO 700 MB LAYER. THE FRONTOGENESIS
REALLY DIES OUT MONDAY AFTERNOON AND IT APPEARS FORCING REALLY
STARTS TO WANE EAST OF THE MISSISSIPPI RIVER DURING THE AFTERNOON
HOURS. WOULD NOT EXPECT MORE THAN JUST SOME LIGHT RAIN SHOWERS AS THE
FRONT MOVES THROUGH. PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST
AND CENTRAL WISCONSIN MAY NOT SEE MORE THAN SOME SPRINKLES. WILL
KEEP PRECIPITATION CHANCES IN THE 20 TO 30 PERCENT RANGE DURING THIS
TIMEFRAME. PLAN ON A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST AS
THE FRONT MOVES THROUGH. LOOK FOR HIGHS ON MONDAY TO RANGE FROM THE
MID TO UPPER 60S ACROSS NORTH CENTRAL WISCONSIN TO THE LOWER 70S
OVER NORTHEAST IOWA. HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE
REGION IN THE WAKE OF THE FRONT MONDAY NIGHT INTO TUESDAY. THE
FORECAST AREA WILL BE IN BETWEEN TWO SYSTEMS...AN APPROACHING TROUGH
OVER SOUTHERN ALBERTA/SASKATCHEWAN/MANITOBA...AND AN UPPER LOW OVER
THE LOWER MISSISSIPPI RIVER VALLEY. PLAN ON MOSTLY SUNNY SKIES ON
TUESDAY WITH HIGHS MAINLY IN THE 70S.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
311 PM CDT SAT SEP 29 2012
FORECAST MODELS ARE LEANING TOWARD A MORE ACTIVE AND COOLER PATTERN
FOR THE LAST HALF OF THE WORK WEEK. WEDNESDAY LOOKS TO BE THE LAST
WARM DAY IN THE EXTENDED PERIOD AHEAD OF STRONG COLD FRONT PUSHING
OUT OF SOUTHERN CANADA ACROSS THE DAKOTAS. THE COLD FRONT IS
EXPECTED TO EDGE INTO THE AREA LATE WEDNESDAY INTO THURSDAY AS A
SHORTWAVE MOVES EAST ACROSS THE DAKOTAS AND LIFTS NORTHEAST INTO
WESTERN ONTARIO. THE TRAJECTORY OF THE TROUGH AND DEEPENING LOW OVER
WESTERN ONTARIO WILL KEEP A BAROCLINIC ZONE ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY THURSDAY INTO FRIDAY. THE BAROCLINIC ZONE
WILL INTERACT WITH A SERIES OF EMBEDDED SHORTWAVES IN SOUTHWEST
FLOW ALOFT. THIS INTERACTION WILL PRODUCE CHANCES FOR RAIN SHOWERS
WEDNESDAY NIGHT INTO THURSDAY. A BROAD UPPER TROUGH WILL SETTLE INTO
THE AREA LATE THURSDAY NIGHT INTO FRIDAY WITH COLDER AIR SPILLING
INTO THE UPPER MISSISSIPPI RIVER VALLEY. THE RAIN MAY MIX WITH OR
CHANGE OVER TO SNOW LATE THURSDAY NIGHT INTO FRIDAY MORNING AS
TEMPERATURES PLUMMET INTO THE 30S. SLIGHT RAIN CHANCES WILL CONTINUE
INTO FRIDAY NIGHT ALONG AND NORTH OF INTERSTATE 94 WITH CYCLONIC
FLOW IN PLACE. A FEW SNOW FLAKES MAY MIX IN LATE IN THE NIGHT.
SURFACE HIGH PRESSURE LOOKS TO BUILD INTO THE AREA ON SATURDAY. PLAN
ON HIGHS ONLY THE UPPER 40S TO LOWER 50S ON SATURDAY UNDER MOSTLY
SUNNY SKIES.
&&
.AVIATION...TONIGHT AND SUNDAY
643 PM CDT SAT SEP 29 2012
FOR TONIGHT...HIGH PRESSURE WILL PROVIDE CLEAR SKIES AT BOTH TAF SITES.
THE ONLY QUESTION IS WHETHER THERE WILL BE ENOUGH OF A RECOVERY IN THE
DEW POINTS FOR THE POSSIBILITY OF SOME SHALLOW GROUND FOG AT KLSE.
THE NAM/WRF SOUNDING WOULD SUGGEST THAT THIS WOULD BE A POSSIBILITY.
MEANWHILE THE GFS AND RAP WOULD SAY NO. SINCE THERE IS STILL A BIT OF
UNCERTAINTY...LEFT THE BCFG IN THE TAF FOR NOW. WILL WATCH THE DEW
POINTS DURING THE NEXT 4 HOURS AND SEE WHETHER THERE IS ANY RECOVERY.
FOR SUNDAY...A SCATTERED TO BROKEN DECK OF CIRRUS WILL MOVE INTO
BOTH TAF SITES DURING THE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
311 PM CDT SAT SEP 29 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
354 AM CDT SUN SEP 30 2012
.DISCUSSION...
338 AM CDT
MAIN FORECAST CHALLENGES THIS MORNING ARE WITH LAKE EFFECT CLOUD
POTENTIAL NOW THROUGH LATE MORNING TODAY...WITH MOSTLY SUNNY SKIES
THEN EXPECTED FOR THE ENTIRE AREA INTO THE AFTERNOON AS TEMPS RISE
TO THE UPPER 60S AND LOW 70S.
LATEST WATER VAPOR IMAGERY DEPICTING A FAIRLY STRONG PIECE OF MID
LEVEL ENERGY WRAPPING AROUND THE CLOSED UPPER LEVEL SYSTEM ACROSS
THE EASTERN GREAT LAKES REGION THIS MORNING. AS THIS
OCCURS...COLDER AIR WILL CONTINUE TO WORK ITS WAY SOUTHWEST OVER
THE LAKE THIS MORNING AND ACROSS THE CWA THROUGH THE AFTERNOON.
WHAT THIS WILL MEAN FOR TODAY IS SLIGHTLY COOLER HIGH TEMPERATURES
ACROSS THE CWA AS WELL AS THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER TO SPILL INTO AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS AND
NORTHWEST INDIANA. AS WAS EXPECTED...LATEST RAP ANALYSIS SHOWING
DELTA TS FINALLY INCREASING ACROSS THE ENTIRE LENGTH OF THE
LAKE...WITH THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING. ALTHOUGH LATEST SATELLITE IMAGERY SHOWING THIS CLOUD
COVER SOMEWHAT SLOW TO DEVELOP OVER THE NORTHERN PORTIONS OF THE
LAKE...SHOULD BEGIN TO SEE AN INCREASE IN THIS DEVELOPMENT OVER
THE NEXT TWO TO THREE HOURS. FAVORED LOW LEVEL FLOW SHOULD KEEP
MOST OF ANY CLOUD COVER OVER AREAS IN FAR NORTHEAST ILLINOIS...BUT
WITH SOME CLOUD COVER TO STILL POSSIBLY SPILL OVER INTO AREAS IN
FAR NORTHWEST INDIANA. ALTHOUGH THIS CLOUD COVER IS EXPECTED TO
DEVELOP AND MOVE ACROSS AREAS NEAR THE LAKE...IT SHOULDNT BE MORE
THAN PARTLY CLOUDY SKIES WITH SOME BRIEF PERIODS OF PARTLY
SUNNY/CLOUDY CONDITIONS THROUGH THE 15Z TIME FRAME. AFTER THIS
TIME FRAME...CLOUD COVER SHOULD BEGIN TO DIMINISH INTO THE
AFTERNOON AS HIGHER PRESSURE SHIFTS DOWN THE LAKE. AFTER THIS
POINT...SKIES SHOULD BE MOSTLY SUNNY INTO THE AFTERNOON WITH
ANOTHER PLEASANT DAY IN STORE. ALTHOUGH TEMPS TODAY WILL BE
SLIGHTLY COOLER THAN YESTERDAY...I DID RAISE TEMPS A COUPLE OF
DEGREES OVER GUIDANCE WITH TEMPERATURES RISING INTO THE LOW 70S
FOR MOST AREAS IN NORTHERN ILLINOIS...WITH TEMPS SLIGHTLY COOLER
IN THE UPPER 60S IF NOT AROUND 70 MARK FOR AREAS NEAR THE LAKE.
NONETHELESS...A PLEASANT DAY WILL BE IN STORE FOR THE AREA TODAY.
AFTER QUIET CONDITIONS ONCE AGAIN TONIGHT INTO THE EARLY PORTIONS
OF MONDAY...A SOMEWHAT MORE ACTIVE WEATHER APPEARS TO BE ON THE
HORIZON. AS MID AND HIGH LEVEL CLOUD INCREASES FROM THE SOUTH ON
MONDAY...TEMPS SHOULD STILL RISE INTO THE LOW 70S ON MONDAY.
ALTHOUGH AS WAS EXPECTED OVER THE LAST 24 HOURS...MODELS CONTINUE
TO TREND TOWARDS BRINGING CURRENT CLOSED UPPER LEVEL LOW OVER THE
SOUTHERN PLAINS NORTHEAST TOWARDS THE AREA BY LATE MONDAY. MODEL
CONSENSUS SEEMS TO BRING THIS UPPER LEVEL SYSTEM AND SURFACE
REFLECTION UP THROUGH THE TENNESSEE VALLEY LATE MONDAY INTO EARLY
TUESDAY MORNING...AS A SEPARATE MID LEVEL TROUGH APPROACHES FROM
THE NORTHERN PLAINS. ALTHOUGH WITH A LACK OF MOISTURE WITH THIS
NORTHERN STREAM MID LEVEL TROUGH...PRECIP SHOULD BE DIMINISHING AS
IT APPROACHES THE CWA. BEST CHANCES FOR SHOWERS WILL BE FOR AREAS
ACROSS THE SOUTHEAST CWA MONDAY NIGHT. THIS SYSTEM WILL SLOWLY
SPIN ACROSS THE REGION...WITH PRECIP POSSIBLY LINGERING ACROSS
THE SAME AREA TUESDAY INTO TUESDAY NIGHT. CURRENT FORECAST KEEPS
PRECIP CHANCES THROUGH LATE IN THE DAY TUESDAY...BUT ITS
CONCEIVABLE THAT THIS SYSTEM WILL TAKE A SLOWER EASTWARD MOVEMENT.
IF THIS WERE TO OCCUR...PRECIP COULD LINGER INTO THE MIDDLE PART
OF THE WEEK BEFORE EXITING. AFTER WEAK RIDGING AND A SLIGHT
INCREASE IN TEMPS ON WEDNESDAY...ANOTHER MID LEVEL SYSTEM AND
SURFACE REFLECTION/FRONTAL BOUNDARY WILL APPROACH THE CWA WITH
PRECIP CHANCES INCREASING ONCE AGAIN TOWARDS THE END OF THE WORK
WEEK. IT WOULD APPEAR THAT MAINLY SHOWERS SHOULD BE OBSERVED AS
THIS SYSTEM PUSHES THROUGH THE AREA ON THURSDAY...BUT WITH SOME
UNCERTAINTY AS TO THE OVERALL AMOUNT OF MOISTURE/INSTABILITY
PRESENT OUT AHEAD OF IT. IF THE ECMWF WERE TO VERIFY...THEN
PRIMARILY SHOWERS WOULD BE OBSERVED. IN CONTRAST...THE GFS SEEMS
TO BE MORE AGGRESSIVE WITH DEWPOINTS AND IF THIS WERE TO
OCCUR...THEN THUNDERSTORMS COULD BE PRESENT OUT AHEAD OF THIS
SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LAKE EFFECT MVFR CIGS PROBABLE IN THE COUPLE HOURS AFTER
DAYBREAK AND LASTING INTO EARLY AFTERNOON...WITH A SMALL CHC FOR
THEM TO BE NEAR 1700 FT AT ONSET.
* NORTHEAST WINDS INCREASING IN SPEED SOON AFTER DAYBREAK.
/DISCUSSION...UPDATED 06Z...
THE COOL FRONT WHICH MOVED THROUGH THE TERMINALS LAST EVE WILL
CONTINUE TO WORK SOUTH TOWARD THE OHIO RIVER VALLEY. COLD AIR
ADVECTION ON NORTHEAST WINDS IN ITS WAKE WILL HELP TO STEEPEN
LAPSE RATES OVER WARM LAKE MICHIGAN. CLOUDS ARE LIKELY TO DEVELOP
ACROSS THE WESTERN HALF OF THE LAKE TOWARD DAYBREAK AND MOVE INTO
NORTHEAST IL AND LIKELY NORTHWEST IN DURING THE MORNING HOURS.
THESE WILL LIKELY BE IN THE MVFR CATEGORY...ESPECIALLY AT
ONSET...AND THEN VERY SLOWLY LIFT TOWARD LATE MORNING INTO THE
AFTERNOON. THESE DO LOOK TO BE PRETTY THIN...UNDER 1500 FT IN
DEPTH...WHICH SHOULD FAVOR SCATTERING IN THE AFTERNOON. WITH THE
WIND DIRECTION FROM THE NORTHEAST OFF OF LAKE
MICHIGAN...OCCASIONAL GUSTS ARE FAVORED FROM MID-MORNING INTO THE
AFTERNOON. SPEEDS WILL DIMINISH TONIGHT AS WEAK RIDGING MOVES INTO
THE GREAT LAKES. WITH STILL GENERALLY COOL AIR OVER THE LAKE...FEW
TO SCT LAKE GENERATED CLOUDS MAY TRY TO EXPAND SLIGHTLY TONIGHT.
BUT LESS IN THE WAY OF AN ADVECTION COMPONENT MAY KEEP ANY
OFFSHORE.
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM CONFIDENCE IN 2000-3500 FT CIGS OCCURRING. HIGHEST
CONFIDENCE BETWEEN 15Z-17Z.
* HIGH CONFIDENCE IN WIND TRENDS.
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH WEDNESDAY...GENERALLY VFR.
THURSDAY INTO FRIDAY...CHANCE OF SHOWERS AND MVFR CIGS.
MTF/IZZI
&&
.MARINE...
224 AM CDT
BEHIND A COOL FRONT WHICH PASSED LATE ON SATURDAY...NORTHEAST FLOW
WILL CONTINUE ACROSS THE LAKE TODAY. THIS WILL BE DIRECTED INTO THE
NEARSHORE AREAS OF ILLINOIS AND INDIANA...FAVORING HIGH WAVES INTO
THE AFTERNOON AND EVENING. HIGH PRESSURE WILL SLIDE SOUTHWARD OVER
THE LAKE TONIGHT INTO EARLY MONDAY EASING WINDS. A WEAK COOL FRONT
WILL PASS FROM WEST TO EAST OVER THE LAKE ON MONDAY NIGHT...OFFERING
A WIND SHIFT BUT NO REAL INCREASE IN SPEED. THAT IS IN PART BECAUSE
LOW PRESSURE WILL BE MOVING NORTHEASTWARD FROM THE LOWER OHIO VALLEY
TO HUDSON BAY TUESDAY INTO WEDNESDAY SLOWING THE AFOREMENTIONED
BOUNDARY. A POTENTIALLY ACTIVE END OF THE WEEK OVER THE WESTERN
GREAT LAKES MAY BE IN STORE AS SEVERAL FORECAST MODELS INDICATE A
STRONG LOW PRESSURE SOMEWHERE IN THE UPPER MIDWEST/GREAT LAKES
REGION...WITH STRONG THERMAL ADVECTION CONDUCIVE FOR GUSTY WINDS
AHEAD AND BEHIND OF THE LOW PRESSURE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ006-ILZ014 UNTIL 4 AM MONDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002 UNTIL 4 AM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
343 AM CDT SUN SEP 30 2012
.DISCUSSION...
338 AM CDT
MAIN FORECAST CHALLENGES THIS MORNING ARE WITH LAKE EFFECT CLOUD
POTENTIAL NOW THROUGH LATE MORNING TODAY...WITH MOSTLY SUNNY SKIES
THEN EXPECTED FOR THE ENTIRE AREA INTO THE AFTERNOON AS TEMPS RISE
TO THE UPPER 60S AND LOW 70S.
LATEST WATER VAPOR IMAGERY DEPICTING A FAIRLY STRONG PIECE OF MID
LEVEL ENERGY WRAPPING AROUND THE CLOSED UPPER LEVEL SYSTEM ACROSS
THE EASTERN GREAT LAKES REGION THIS MORNING. AS THIS
OCCURS...COLDER AIR WILL CONTINUE TO WORK ITS WAY SOUTHWEST OVER
THE LAKE THIS MORNING AND ACROSS THE CWA THROUGH THE AFTERNOON.
WHAT THIS WILL MEAN FOR TODAY IS SLIGHTLY COOLER HIGH TEMPERATURES
ACROSS THE CWA AS WELL AS THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER TO SPILL INTO AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS AND
NORTHWEST INDIANA. AS WAS EXPECTED...LATEST RAP ANALYSIS SHOWING
DELTA TS FINALLY INCREASING ACROSS THE ENTIRE LENGTH OF THE
LAKE...WITH THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING. ALTHOUGH LATEST SATELLITE IMAGERY SHOWING THIS CLOUD
COVER SOMEWHAT SLOW TO DEVELOP OVER THE NORTHERN PORTIONS OF THE
LAKE...SHOULD BEGIN TO SEE AN INCREASE IN THIS DEVELOPMENT OVER
THE NEXT TWO TO THREE HOURS. FAVORED LOW LEVEL FLOW SHOULD KEEP
MOST OF ANY CLOUD COVER OVER AREAS IN FAR NORTHEAST ILLINOIS...BUT
WITH SOME CLOUD COVER TO STILL POSSIBLY SPILL OVER INTO AREAS IN
FAR NORTHWEST INDIANA. ALTHOUGH THIS CLOUD COVER IS EXPECTED TO
DEVELOP AND MOVE ACROSS AREAS NEAR THE LAKE...IT SHOULDNT BE MORE
THAN PARTLY CLOUDY SKIES WITH SOME BRIEF PERIODS OF PARTLY
SUNNY/CLOUDY CONDITIONS THROUGH THE 15Z TIME FRAME. AFTER THIS
TIME FRAME...CLOUD COVER SHOULD BEGIN TO DIMINISH INTO THE
AFTERNOON AS HIGHER PRESSURE SHIFTS DOWN THE LAKE. AFTER THIS
POINT...SKIES SHOULD BE MOSTLY SUNNY INTO THE AFTERNOON WITH
ANOTHER PLEASANT DAY IN STORE. ALTHOUGH TEMPS TODAY WILL BE
SLIGHTLY COOLER THAN YESTERDAY...I DID RAISE TEMPS A COUPLE OF
DEGREES OVER GUIDANCE WITH TEMPERATURES RISING INTO THE LOW 70S
FOR MOST AREAS IN NORTHERN ILLINOIS...WITH TEMPS SLIGHTLY COOLER
IN THE UPPER 60S IF NOT AROUND 70 MARK FOR AREAS NEAR THE LAKE.
NONETHELESS...A PLEASANT DAY WILL BE IN STORE FOR THE AREA TODAY.
AFTER QUIET CONDITIONS ONCE AGAIN TONIGHT INTO THE EARLY PORTIONS
OF MONDAY...A SOMEWHAT MORE ACTIVE WEATHER APPEARS TO BE ON THE
HORIZON. AS MID AND HIGH LEVEL CLOUD INCREASES FROM THE SOUTH ON
MONDAY...TEMPS SHOULD STILL RISE INTO THE LOW 70S ON MONDAY.
ALTHOUGH AS WAS EXPECTED OVER THE LAST 24 HOURS...MODELS CONTINUE
TO TREND TOWARDS BRINGING CURRENT CLOSED UPPER LEVEL LOW OVER THE
SOUTHERN PLAINS NORTHEAST TOWARDS THE AREA BY LATE MONDAY. MODEL
CONSENSUS SEEMS TO BRING THIS UPPER LEVEL SYSTEM AND SURFACE
REFLECTION UP THROUGH THE TENNESSEE VALLEY LATE MONDAY INTO EARLY
TUESDAY MORNING...AS A SEPARATE MID LEVEL TROUGH APPROACHES FROM
THE NORTHERN PLAINS. ALTHOUGH WITH A LACK OF MOISTURE WITH THIS
NORTHERN STREAM MID LEVEL TROUGH...PRECIP SHOULD BE DIMINISHING AS
IT APPROACHES THE CWA. BEST CHANCES FOR SHOWERS WILL BE FOR AREAS
ACROSS THE SOUTHEAST CWA MONDAY NIGHT. THIS SYSTEM WILL SLOWLY
SPIN ACROSS THE REGION...WITH PRECIP POSSIBLY LINGERING ACROSS
THE SAME AREA TUESDAY INTO TUESDAY NIGHT. CURRENT FORECAST KEEPS
PRECIP CHANCES THROUGH LATE IN THE DAY TUESDAY...BUT ITS
CONCEIVABLE THAT THIS SYSTEM WILL TAKE A SLOWER EASTWARD MOVEMENT.
IF THIS WERE TO OCCUR...PRECIP COULD LINGER INTO THE MIDDLE PART
OF THE WEEK BEFORE EXITING. AFTER WEAK RIDGING AND A SLIGHT
INCREASE IN TEMPS ON WEDNESDAY...ANOTHER MID LEVEL SYSTEM AND
SURFACE REFLECTION/FRONTAL BOUNDARY WILL APPROACH THE CWA WITH
PRECIP CHANCES INCREASING ONCE AGAIN TOWARDS THE END OF THE WORK
WEEK. IT WOULD APPEAR THAT MAINLY SHOWERS SHOULD BE OBSERVED AS
THIS SYSTEM PUSHES THROUGH THE AREA ON THURSDAY...BUT WITH SOME
UNCERTAINTY AS TO THE OVERALL AMOUNT OF MOISTURE/INSTABILITY
PRESENT OUT AHEAD OF IT. IF THE ECMWF WERE TO VERIFY...THEN
PRIMARILY SHOWERS WOULD BE OBSERVED. IN CONTRAST...THE GFS SEEMS
TO BE MORE AGGRESSIVE WITH DEWPOINTS AND IF THIS WERE TO
OCCUR...THEN THUNDERSTORMS COULD BE PRESENT OUT AHEAD OF THIS
SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LAKE EFFECT MVFR CIGS PROBABLE NEAR OR SOON AFTER
DAYBREAK...WITH A CHC FOR THEM TO BE NEAR 1700 FT AT ONSET.
* NORTHEAST WINDS INCREASING IN SPEED SOON AFTER DAYBREAK.
//DISCUSSION...UPDATED 06Z...
THE COOL FRONT WHICH MOVED THROUGH THE TERMINALS LAST EVE WILL
CONTINUE TO WORK SOUTH TOWARD THE OHIO RIVER VALLEY. COLD AIR
ADVECTION ON NORTHEAST WINDS IN ITS WAKE WILL HELP TO STEEPEN
LAPSE RATES OVER WARM LAKE MICHIGAN. CLOUDS ARE LIKELY TO DEVELOP
ACROSS THE WESTERN HALF OF THE LAKE TOWARD DAYBREAK AND MOVE INTO
NORTHEAST IL AND LIKELY NORTHWEST IN DURING THE MORNING HOURS.
THESE WILL LIKELY BE IN THE MVFR CATEGORY...ESPECIALLY AT
ONSET...AND THEN VERY SLOWLY LIFT TOWARD LATE MORNING INTO THE
AFTERNOON. THESE DO LOOK TO BE PRETTY THIN...UNDER 1500 FT IN
DEPTH...WHICH SHOULD FAVOR SCATTERING IN THE AFTERNOON. WITH THE
WIND DIRECTION FROM THE NORTHEAST OFF OF LAKE
MICHIGAN...OCCASIONAL GUSTS ARE FAVORED FROM MID-MORNING INTO THE
AFTERNOON. SPEEDS WILL DIMINISH TONIGHT AS WEAK RIDGING MOVES INTO
THE GREAT LAKES. WITH STILL GENERALLY COOL AIR OVER THE LAKE...FEW
TO SCT LAKE GENERATED CLOUDS MAY TRY TO EXPAND SLIGHTLY TONIGHT.
BUT LESS IN THE WAY OF AN ADVECTION COMPONENT MAY KEEP ANY
OFFSHORE.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE IN MVFR CIGS OCCURRING. HIGHEST CONFIDENCE
BETWEEN 14Z-17Z.
* HIGH CONFIDENCE IN WIND TRENDS.
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH WEDNESDAY...GENERALLY VFR.
THURSDAY INTO FRIDAY...CHANCE OF SHOWERS AND MVFR CIGS.
MTF/IZZI
&&
.MARINE...
224 AM CDT
BEHIND A COOL FRONT WHICH PASSED LATE ON SATURDAY...NORTHEAST FLOW
WILL CONTINUE ACROSS THE LAKE TODAY. THIS WILL BE DIRECTED INTO THE
NEARSHORE AREAS OF ILLINOIS AND INDIANA...FAVORING HIGH WAVES INTO
THE AFTERNOON AND EVENING. HIGH PRESSURE WILL SLIDE SOUTHWARD OVER
THE LAKE TONIGHT INTO EARLY MONDAY EASING WINDS. A WEAK COOL FRONT
WILL PASS FROM WEST TO EAST OVER THE LAKE ON MONDAY NIGHT...OFFERING
A WIND SHIFT BUT NO REAL INCREASE IN SPEED. THAT IS IN PART BECAUSE
LOW PRESSURE WILL BE MOVING NORTHEASTWARD FROM THE LOWER OHIO VALLEY
TO HUDSON BAY TUESDAY INTO WEDNESDAY SLOWING THE AFOREMENTIONED
BOUNDARY. A POTENTIALLY ACTIVE END OF THE WEEK OVER THE WESTERN
GREAT LAKES MAY BE IN STORE AS SEVERAL FORECAST MODELS INDICATE A
STRONG LOW PRESSURE SOMEWHERE IN THE UPPER MIDWEST/GREAT LAKES
REGION...WITH STRONG THERMAL ADVECTION CONDUCIVE FOR GUSTY WINDS
AHEAD AND BEHIND OF THE LOW PRESSURE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ006-ILZ014 UNTIL 4 AM MONDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002 UNTIL 4 AM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
332 AM CDT SUN SEP 30 2012
.SHORT TERM /TODAY/...
SURFACE RIDGE AXIS WILL REMAIN IN PLACE ACROSS IOWA WITH LITTLE
CHANGE IN THE FORECAST. SOME HIGH CLOUDS WILL DRIFT OVERHEAD WHICH
MAY TAKE AWAY SOME INSOLATION TODAY ALONG WITH SLIGHTLY MODIFIED
850MB TEMPERATURES...THEREFORE HIGHS TODAY LIKELY A DEGREE OR TWO
LESS THAN SATURDAY. THREAT OF PRECIPITATION REMAINS NIL WITH VERY
LIMITED MOISTURE AND FORCING.
.LONG TERM /TONIGHT THROUGH SATURDAY/...
SEVERAL WEATHER SYSTEMS ARE SET TO IMPACT THE REGION IN THE COMING
SEVEN DAYS...INCLUDING A DRAMATIC SHIFT IN TEMPERATURES TOWARD THE
END OF THE WEEK. THE RIDGING THAT HAS BROUGHT US QUIET AND MILD
WEATHER THIS WEEKEND WILL BE SLOWLY PINCHED OFF TODAY BETWEEN A 500
MB CUTOFF LOW OVER ARKANSAS AND A SHORTWAVE MOVING ACROSS SOUTHERN
CANADA. THE WEAKNESS IN THE RIDGE CREATED BY THE SOUTHERN LOW WILL
ALLOW THE NORTHERN SHORTWAVE TO DIVE SOUTHEASTWARD TONIGHT AND
MONDAY...PUSHING A SURFACE TROUGH ACROSS OUR AREA ON MONDAY. THE
PASSAGE OF THE NORTHERN WAVE WILL BE ACCOMPANIED BY A BRIEF SHOT OF
LIFT HOWEVER THERE IS SUBSTANTIAL DRY AIR IN THE LOWER LEVELS
INDICATED BY FORECAST SOUNDINGS. HAVE THUS INCLUDED SLIGHT CHANCE
POPS ON MONDAY BUT ANY RAINFALL THAT DOES OCCUR WILL BE SPOTTY AND
VERY LIGHT. BEHIND THE SURFACE TROUGH A PACIFIC HIGH WILL BUILD
IN...WITH AN AIRMASS ONLY A LITTLE COOLER THAN WHAT PRECEDED THE
FRONT AND HIGHS WELL INTO THE 70S FORECAST ON MONDAY AND TUESDAY.
MEANWHILE THE WAVE THAT MOVED BY ON SUNDAY NIGHT/MONDAY WILL PHASE
WITH THE CUTOFF LOW TO THE SOUTH...RESULTING IN AN ELONGATED 500 MB
TROUGH THAT WILL LINGER FROM THE OZARKS UP TO THE GREAT LAKES FROM
MONDAY NIGHT THROUGH TUESDAY BEFORE IT FINALLY MOVES DOWNSTREAM ON
TUESDAY NIGHT.
BY WEDNESDAY MORNING THE FIRST 500 MB TROUGH WILL BE MOVING EASTWARD
ACROSS THE OHIO RIVER VALLEY...WHILE AT THE SAME TIME A MORE POTENT
NORTHERN STREAM TROUGH WILL BE WHEELING FROM SOUTHWESTERN CANADA
INTO THE NORTHERN U.S. ROCKIES. BETWEEN THESE TWO SYSTEMS A BRIEF
SHOT OF RIDGING WILL BUILD ACROSS THE MIDWEST AND IOWA ON WEDNESDAY.
AT THE SURFACE THIS WILL BE REFLECTED BY MODEST SOUTHERLY FLOW AND
MUCH WARMER TEMPERATURES. HAVE TRENDED AFTERNOON HIGHS UP BY SEVERAL
DEGREES ON WEDNESDAY...INTO THE LOWER 80S ACROSS MUCH OF THE CWA AND
WE COULD EVEN SEE SOME MID-80S ESPECIALLY ACROSS OUR SOUTHERN
COUNTIES. ANY LOVERS OF WARM WEATHER SHOULD BREATHE DEEP ON
WEDNESDAY HOWEVER...AS THE TROUGH MOVING OVER THE NORTHERN ROCKIES
WILL SUBSEQUENTLY DIG EASTWARD AND PUSH A POWERFUL SURFACE COLD
FRONT ACROSS IOWA ON WEDNESDAY NIGHT/THURSDAY. THERE REMAIN SOME
DIFFERENCES IN TIMING OF FRONTAL PASSAGE BETWEEN THE VARIOUS MODELS
WHICH PRECLUDES HIGHER THAN 30-40 POPS FOR NOW...HOWEVER THERE IS A
GOOD SIGNAL FOR SOME SHOWERS AND UNANIMOUS SIGNS OF A MUCH COOLER
AIRMASS BEHIND THE FRONT THAT WILL DROP TEMPERATURES SIGNIFICANTLY
BY THURSDAY OR THURSDAY NIGHT. THEREAFTER...SEVERAL SUCCEEDING 500
MB SHORTWAVES WILL CARVE OUT A LARGE BOWL OF CYCLONIC FLOW OVER THE
NORTHERN U.S. THAT WILL KEEP US COOL AT LEAST THROUGH THE WEEKEND
WITH HIGHS ACROSS IOWA ONLY IN THE 50S FROM FRIDAY THROUGH SUNDAY.
DURING THIS TIME FRAME WE MAY SEE ONE OR MORE SHOTS OF LIGHT SHOWERS
AS THE AFOREMENTIONED SHORTWAVES MOVE OVERHEAD...HOWEVER MOISTURE
WILL BE LIMITED AND ONLY ISOLATED/LIGHT RAINFALL IS EXPECTED AT THIS
TIME.
&&
.AVIATION...30/06Z
HIGH PRESSURE WILL BE IN PLACE THROUGH THE PERIOD WITH MAINLY VFR
CONDITIONS AND CLEAR SKIES. ONLY EXCEPTION APPEARS TO BE AT
KOTM...AND IS ALSO SHOWING UP AT KAMW...WHERE MVFR HZ VSYBS HAVE
DEVELOPED. ONLY EXPLANATION SEEMS TO BE HARVEST RESIDUE TRAPPED
UNDER STRONG INVERSION AS DEPICTED IN RAP FORECAST SOUNDINGS. WINDS
WILL BE LIGHT WITH ONLY SLIGHT INCREASE DURING PEAK HEATING SUN.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...COGIL
LONG TERM...LEE
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1200 AM CDT SUN SEP 30 2012
.SHORT TERM /TONIGHT/...
RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE STATE TONIGHT HOWEVER
MODIFICATION OF THE AIRMASS ASSOCIATED WITH IT IS IN PROGRESS. SFC
THETA-E VALUES WILL TREND A BIT HIGHER TONIGHT THAN THE PREVIOUS
NIGHT. THE HIGHER SFC THETA-E VALUES IN ADDITION TO WARMING IN THE
950-925 MB LAYER...WHICH WILL BE THE BASE OF THE OVERNIGHT
INVERSION...WILL HELP HOLD TEMPERATURES UP A FEW DEGREES TONIGHT
FROM THIS MORNINGS LOWS. OTHERWISE EXPECT MOSTLY CLEAR SKIES AND
LIGHT WINDS TO PREVAIL.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
THE RIDGING OVER THE MIDWEST BEGINS TO BREAK DOWN ON SUNDAY WITH THE
ENTRANCE OF A DECENT SHORT WAVE OVER CANADA. MEANWHILE AN UPPER LOW
OVER TX/OK/LA DEEPENS. THE SURFACE REFLECTION OF THE NORTHERN
SYSTEM IN THE FORM OF A COLD FRONT WILL BE PUSHING OUT OF THE
NORTHERN PLAINS LATE SUNDAY AND SUNDAY NIGHT THEN ACROSS THE UPPER
MIDWEST MONDAY. FORECAST SOUNDING ARE DRY THROUGH 700 MB THOUGH
THERE IS SOME FORCING WITH THE FRONT...WHICH DIMINISHES AS IT MOVES
EAST ACROSS CENTRAL IOWA. MY CONFIDENCE IS NOT HIGH ENOUGH TO GO
WITH POPS AND MENTION SHOWERS THOUGH THERE IS MOISTURE AT 700 MB AND
THE FORCING WITH THE FRONT SUGGESTS THAT WE COULD SEE SPRINKLES.
TEMPERATURES MONDAY WILL BE A LITTLE TRICKY WITH A WARM SOUTHERLY
FLOW IN PLACE ACROSS THE EAST/SOUTHEAST AND THE COLD FRONT PUSHING
INTO THE NORTHWEST IN THE MORNING. THE AIR IS NOT REALLY COLD
BEHIND THE FRONT SO I TEMPS SHOULD REMAIN IN THE 70S WITH THE
WARMEST READINGS FAR SOUTH.
RIDGING BUILDS BACK INTO THE UPPER MIDWEST MONDAY NIGHT THROUGH
WEDNESDAY FOR MORE DRY CONDITIONS WITH WARMING TEMPERATURES. HIGHS
SHOULD BE BACK AROUND 80 IN THE FAR SOUTH WITH MID 70S OR SO NORTH.
MODELS VARY ON THE STRENGTH OF THE RIDGE BUILDING BACK SO I WAS
CONSERVATIVE IN TEMPS BUT OF THE EURO IS RIGHT THEN THE ENTIRE CWA
WILL BE A FEW DEGREES ABOVE WHAT I CURRENTLY HAVE. THE EURO IS
CURRENTLY THE OUTLIER SO I DID NOT PUT ALL MY CONFIDENCE IN THAT
MODEL JUST YET.
THEN FOR THE GAME CHANGER SYSTEM WEDNESDAY NIGHT AND THURSDAY. A
DEEPENING LOW OVER CANADA CARVES OUT A TROUGH OVER THE MIDWEST AND A
STRONG COLD FRONT PUSHES IN OVERNIGHT WEDNESDAY NIGHT INTO THURSDAY
MORNING. ONCE AGAIN SOUNDINGS ARE SHOWING A DECIDED LACK OF
MOISTURE WITH THIS SYSTEM BUT FORCING IS STRONGER AND MORE FOCUSED
ALONG THE BOUNDARY SO I AM MORE CONFIDENT THAT CHANCE POPS ARE
WARRANTED FOR THIS PERIOD. PRECIP SHOULD BE IN THE FORM OF RAIN BUT
TEMPS WILL DROP TO FREEZING OR BELOW NORTH. THE FORCING WITH THE
FRONT HOWEVER WILL BE DONE AND PRECIP SHOULD BE OVER BEFORE IT
SWITCHES TO SNOW. IF HOWEVER THE COLDER AIR SURGES IN QUICKER OR
THE FORCING LASTS LONGER WE MAY NEED TO ADDRESS AT LEAST A RAIN TO
SNOW WORDING WEDNESDAY NIGHT. AT THIS POINT THOUGH IT APPEARS
UNLIKELY. THIS WILL CHANGE TO TEMP TRENDS OVER THE UPPER MIDWEST
INTO NEXT WEEK. THE UPPER FLOW GOES ZONAL BUT A LARGE SURFACE HIGH
OF CANADIAN ORIGIN PARKS ITSELF OVER THE NORTHERN PLAINS/UPPER
MIDWEST KEEPING SOME VERY COLD AIR IN PLACE. HIGHS IN THE 70S WILL
BE REPLACED WITH HIGHS IN THE 50S AND LOWS IN THE 40S WITH LOWS IN
THE 30S.
&&
.AVIATION...30/06Z
HIGH PRESSURE WILL BE IN PLACE THROUGH THE PERIOD WITH MAINLY VFR
CONDITIONS AND CLEAR SKIES. ONLY EXCEPTION APPEARS TO BE AT
KOTM...AND IS ALSO SHOWING UP AT KAMW...WHERE MVFR HZ VSYBS HAVE
DEVELOPED. ONLY EXPLANATION SEEMS TO BE HARVEST RESIDUE TRAPPED
UNDER STRONG INVERSION AS DEPICTED IN RAP FORECAST SOUNDINGS. WINDS
WILL BE LIGHT WITH ONLY SLIGHT INCREASE DURING PEAK HEATING SUN.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...DONAVON
LONG TERM...FAB
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1129 PM MDT SAT SEP 29 2012
.UPDATE...
ISSUED AT 745 PM MDT SAT SEP 29 2012
JUST COMPLETED AN UPDATE THROUGH TOMORROW. LATEST MODELS CONFIRMED
BY SURFACE ANALYSIS. SURFACE TROUGH STILL CLOSE TO THE FRONT AND
MODELS HAVE THIS TOO FAR EAST. THE RUC FOLLOWED BY THE HRRR AND
NAM WERE THE BEST MODELS WITH THIS. AS A RESULT WINDS WILL STAY
FROM A SOUTH TO SOUTHEAST DIRECTION WELL INTO THE NIGHT ALLOWED AN
INCREASE IN BLYR MOISTURE. BECAUSE OF ALL THIS INCREASED CLOUD
COVER THROUGH THE NIGHT TO ACCOUNT FOR STRATUS AND ALSO INSERTED
AREAS OF FOG OVER MOST OF THE AREA BEGINNING AT 06Z. ALSO ADJUSTED
THE WINDS AND DEWPOINTS ACCORDING THE RUC...NAM...AND HRRR.
CURRENTLY LITTLE IF ANY PRECIPITATION OCCURRING CLOSE TO THE
FORECAST AREA. 00Z SOUNDINGS AND SATELLITE SHOW DEEP DRY LAYER AND
LITTLE IF ANY LIFT ACROSS THE AREA AT THIS TIME. LIFT FROM INCOMING
SURFACE TROUGH AND SHORTWAVE TROUGH AND DEEPER MOISTURE INCREASES
AFTER 06Z...ESPECIALLY BY LATER IN THE NIGHT. ALSO ELEVATED CAPE
INCREASES DRAMATICALLY WITH CINH THAT CAN BE OVERCOME. SO CONFINED
A SLIGHT CHANCE OF THUNDERSTORMS UNTIL AFTER 06Z AND TO THE WEST
OF THE COLORADO BORDER. THEN INCREASED THUNDERSTORM CHANCES AFTER
12Z AND GRADUALLY PROGRESS THIS ACROSS THE FORECAST AREA THROUGH
THE DAY.
&&
.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 142 PM MDT SAT SEP 29 2012
NORTHWEST FLOW WILL BRING A SHORTWAVE INTO THE REGION LATE TONIGHT
AND SUNDAY. A SURFACE TROUGH IN EASTERN COLORADO TONIGHT WILL SHIFT
EAST ACROSS NORTHWEST KANSAS SUNDAY.
SHORTWAVE TIMING WILL KEEP POPS NIL ACROSS MOST OF THE FA WITH
EXCEPTION OF EASTERN COLORADO THIS EVENING. EASTERN COLORADO WILL BE
THE FIRST ZONES TO HAVE ANY CHANCE THIS EVENING. WEAK DYNAMICS WILL
THEN SPREAD INTO NORTHWEST KANSAS/EXTREME SOUTHWEST NEBRASKA AFTER
06Z SUNDAY. AFTER A MORNING LULL, THERE WILL BE A CHANCE OF
THUNDERSTORMS ACROSS NORTHWEST KANSAS SUNDAY AFTERNOON GENERALLY
EAST OF GOODLAND.
BOUNDARY LAYER RH GETS HIGH ENOUGH TO SUPPORT PATCHY FOG OVER THE
SOUTHEAST ZONES LATE TONIGHT. TEMPERATURES TONIGHT WILL FALL TO THE
LOWER 50S. HIGHS SUNDAY WILL BE IN THE UPPER 70S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 220 PM MDT SAT SEP 29 2012
THE 12Z GFS AND ECMWF HAVE SLOWED THE PRE-FRONTAL SURFACE TROUGH DOWN
FOR SUNDAY TO WHAT THE NAM HAS BEEN SHOWING THE LAST COUPLE OF
DAYS. WITH THE LATEST GEFS MEMBERS ALSO SLOWING THE TROUGH DOWN
WILL KEEP HIGHER PRECIP. CHANCES OVER THE EASTERN 1/3 OF THE AREA SUNDAY EVENING.
EXTENDED THE SLIGHT CHANCES OVER THE EAST PAST MIDNIGHT DUE TO THE
SLOWER TROUGH PASSAGE. MEANWHILE A COOLER AIR MASS WILL BEGIN TO MOVE INTO
THE AREA DURING THE OVERNIGHT HOURS.
MONDAY DRIER AIR MOVES INTO THE AREA SO WILL CONTINUE TO LEAVE THE
FORECAST DRY DESPITE AN UPPER LEVEL SHORT WAVE TROUGH MOVING THROUGH
DURING THE AFTERNOON. SURFACE WINDS WILL STRENGTHEN DURING THE
AFTERNOON AS WINDS OF 20 TO 30 KTS MIX DOWN FROM 700MB.
MONDAY NIGHT WILL ALSO BE DRY AS A SURFACE AND UPPER LEVEL RIDGE
MOVE THROUGH AND POINT SOUNDINGS CONTINUE TO DRY OUT.
FOR THE TUESDAY THROUGH SATURDAY PERIOD MODELS ARE COMING INTO
BETTER AGREEMENT REGARDING THE TIMING OF THE UPPER LEVEL TROUGH
DROPPING DOWN FROM CANADA INTO THE CENTRAL PLAINS. CURRENT MODEL
RUNS HAVE THE TROUGH PASSING THROUGH THE AREA WEDNESDAY NIGHT...WITH
THE MAJORITY OF THE LIFT WITH THE TROUGH NORTH OF THE AREA. WITH
1000-500MB RELATIVE HUMIDITY INCREASING AS THE TROUGH MOVES
THROUGH...HAVE INTRODUCED PRECIP. CHANCES ALONG/NORTH OF THE
NEBRASKA LINE. THE TROUGH BROADENS DURING THE LATTER HALF OF THE
WORK WEEK AS ANOTHER SHORT WAVE TROUGH DIVES SOUTH ACROSS THE
PLAINS...PASSING OVER THE AREA SATURDAY. MODELS CURRENTLY PLACE THE
MAJORITY OF THE 1000-500MB RELATIVE HUMIDITY JUST NORTH OF THE AREA...SO
WILL KEEP PRECIP. CHANCES IN THE SILENT CATEGORY FOR NOW.
A STRONG COLD FRONT WILL MOVE THROUGH THE AREA WEDNESDAY NIGHT.
BELOW NORMAL TEMPERATURES CAN BE EXPECTED AFTER WEDNESDAY AS THE COOLER AIR
MASS REMAINS OVER THE AREA. SOME LOCATIONS...ESPECIALLY THOSE IN
LOW LYING AREAS MAY SEE FROST FRIDAY AND SATURDAY MORNING AS LOW
TEMPERATURES APPROACH THE MID 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1122 PM MDT SAT SEP 29 2012
NOT TOO MUCH HAS CHANGED FROM EARLIER THINKING. STILL A LOT OF
UNCERTAINTY WITH A NUMBER PARAMETERS. MODELS HAVE BACKED OFF ON
COVERAGE/TIMING OF PRECIPITATION...STRATUS/FOG...AND QUICKENED
THE ARRIVAL OF THE SURFACE TROUGH. HOWEVER...CURRENT SURFACE
OBSERVATIONS ARE INDICATING FOG HAS BEGUN TO DEVELOP TO OUR SOUTH
AND SURFACE TROUGH IS STILL WELL TO THE WEST. 88D SHOWS THAT
RETURNS HAVE INCREASED A LITTLE TO THE NORTHWEST OF OUR FORECAST AREA.
SO HAVE ONLY MADE MINOR ADJUSTMENTS TO THE TAFS FROM THE 00Z
ISSUANCE. EXPECT MVFR CONDITIONS UNTIL THE SURFACE TROUGH AND
PRECIPITATION ARRIVES/BEGINS. DUE TO THAT UNCERTAINTY KEPT ONLY THE
VCTS MENTION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...FS
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
437 AM EDT SUN SEP 30 2012
.SYNOPSIS...
A COLD UPPER LEVEL LOW WILL BRING SHOWERS AND ISOLATED
THUNDERSTORMS TO THE UPPER OHIO VALLEY TODAY. HIGH PRESSURE WILL
FOLLOW WITH A DRY BREAK MONDAY BEFORE A LOW PRESSURE SYSTEM...COMING
SLOWLY NORTH FROM LOUISIANA...BRINGS SHOWERS MONDAY NIGHT INTO
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE ADDED ISOLATED THUNDERSTORMS TO THE INCREASING COVERAGE OF
SHOWERS ACROSS THE UPPER OHIO VALLEY TODAY. RECENT RAP MODEL
OUTPUT SHOWS H5 TEMPERATURES AS COLD AS -24C PASSING THROUGH AT
LEAST WESTERN PENNSYLVANIA...IN ASSOCIATION WITH THE COLD UPPER
LEVEL LOW CENTER THAT WILL BE SWINGING THROUGH THE UPPER OHIO
VALLEY INTO LATE AFTERNOON. THERE CAN BE BRIEF EPISODES OF SMALL
HAIL/GRAUPEL/ BUT COVERAGE TOO RESTRICTED TO CONFIDENTLY MENTION.
HAVE KEPT MENTION OF PATCHY FOG PER RECENT SURFACE DATA...BUT
EXPECT FOG TO DISSIPATE BEFORE 9 AM.
FORECASTED HIGH TEMPERATURES TODAY TO BE UP TO 5 DEGREES COLDER
THAN NORMAL PER RECENT GFS AND NAM MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
PER RECENT SREF AND NAM MODEL OUTPUT...THAT SHOW A FASTER UPPER
LOW CENTER EXIT EAST...HAVE ENDED SHOWER CHANCES EARLIER THIS EVENING.
WITH CLOUDS LIKEWISE DECREASING FASTER...CONCUR WITH NAM MODEL
PROFILES THAT NOCTURNAL RADIATIONAL COOLING SHOULD PROMOTE PATCHY
FOG LATE TONIGHT.
EASTBOUND HIGH PRESSURE SHOULD PROVIDE A DRY BREAK FOR MOST OF
DAYTIME MONDAY. THEN SREF MODEL OUTPUT SHOWS A LOW PRESSURE
SYSTEM...COMING SLOWLY NORTH FROM LOUISIANA...WILL LIKELY PROVIDE
THE UPPER OHIO VALLEY WITH SHOWERS MONDAY NIGHT AND TUESDAY. A
TRAILING UPPER LEVEL TROUGH MAY CONTINUE A CHANCE OF SHOWERS
TUESDAY NIGHT AND DAYTIME WEDNESDAY. PER SPC CONVECTIVE OUTLOOK
AND NAM MODEL PROFILES...HAVE ADDED MENTION OF A CHANCE OF
THUNDERSTORMS WEDNESDAY AFTERNOON.
FORECASTED TEMPERATURES TO CONTINUE COOLER THAN NORMAL
MONDAY...BUT THEN WARM TO AS MUCH AS 7 TO 10 DEGREES ABOVE NORMAL
TUESDAY AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THE UPPER LOW PUSHES INTO NEW YORK STATE BY WEDNESDAY
EVENING...ENDING THE SHOWERS ACROSS THE FORECAST AREA.
HIGH PRESSURE BUILDING INTO THE DISTRICT THURSDAY WILL BRING DRY
WEATHER INTO THURSDAY NIGHT. A WEAK COLD FRONT PASSING ACROSS THE
DISTRICT FRIDAY WILL BRING A CHANCE OF SHOWERS. HIGH PRESSURE
BEHIND THE FRONT WILL BRING A RETURN OF DRY WEATHER FOR SATURDAY.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
GENERAL VFR CONDITIONS THROUGH MID-MORNING WITH BKN-OVC STRATOCU AND
SCT SHOWERS/STORMS. THERE WILL BE PATCHY MVFR FOG THROUGH DAWN AT
THE USUAL PORTS.
LARGE UL SYSTEM WILL ROTATE THROUGH THE UPPER OHIO VALLEY THIS
AFTERNOON. THIS WILL KEEP IN CLOUDS AND THE RISK FOR
SHOWERS/STORMS. FOR FORECAST...WILL GO WITH VFR CIGS IN THE
SOUTH...WHILE MVFR CIGS ARE POSSIBLE TO THE NORTH. A SHOWER/STORM
IS POSSIBLE AT ANY TIME TODAY...SO WILL INCLUDE THE MENTION OF
NON-RESTRICTIVE SHOWERS AT ALL PORTS UNTIL LATE AFTERNOON.
.OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
SKIES WILL CLEAR TONIGHT...WITH POSSIBLE PATCHY IFR FOG AND STRATUS
TOWARD DAWN ON MON. GENERAL VFR RETURNS FOR DAYTIME MONDAY...BUT A
LOW PRESSURE SYSTEM WILL PROVIDE SHOWERS AND POSSIBLE RESTRICTIONS
MONDAY NIGHT INTO WEDNESDAY. VFR RETURNS WEDNESDAY NIGHT INTO
THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
511 AM EDT SUN SEP 30 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EDT SUN SEP 30 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER THE
ERN GREAT LAKES AND A RIDGE UPSTREAM FROM MN TO NEAR JAMES BAY.
SINCE THE LOW HAS EDGED SLIGHTLY TO THE WEST...COOLER AIR AND AN
INCREASE IN LOW LEVEL MOISTURE HAS ALSO PUSHED WESTWARD THROUGH
UPPER MI WITH SOME PATCHY LOW CLOUDS...ESPECIALLY IN LOCATIONS FAVORED
BY NE UPSLOPE FLOW. FARTHER UPSTREAM...A SHRTWV AND NOSE OF A
250-300 JET STREAK WAS MOVING THROUGH SRN ALBERTA. AT THE SFC...A
RIDGE EXTENDED FROM NRN QUEBEC TO THE SOUTHWEST INTO THE NRN GREAT
LAKES.
TODAY...EXPECT ANY LINGERING LOWER CLOUDS TO THIN OUT BY MID TO LATE
MORNING WITH INCREASING DAYTIME HEATING. OTHERWISE...HIGH PRES WILL
CONTINUE TO DOMINATE THE REGION WITH MOSTLY SUNNY SKIES AND LIGHT
ERLY WINDS. WITH LITTLE CHANGE IN THE POSITION OF THE 925-850 MB
THERMAL TROUGH...TEMPS SHOULD BE SIMILAR TO SATURDAY WITH MAX
READINGS IN THE MID TO UPPER 60S INLAND AND AROUND 60 NEAR LAKE
SUPERIOR.
TONIGHT...THE SRN CANADA SHRTWV WILL MOVE THROUGH THE NRN PLAINS AND
WILL HELP NUDGE THE BLOCKY DOWNSTREAM RIDGE/TROUGH TO THE EAST.
HOWEVER...MDLS/ENSEMBLE CONSENSUS SUGGESTS THAT ANY PCPN WITH THE
TROUGH SHOULD REMAIN WEST OF LAKE SUPERIOR. AN INCREASE IN SRLY
WINDS AND SOME MID AND HIGH CLOUDS SHOULD KEEP TEMPS FROM FALLING
OFF AS MUCH. LOOK FOR MIN READINGS FROM THE UPPER 30S TO AROUND 40
INLAND AND CLOSE TO 50 FOR THE GREAT LAKES AND WHERE DOWNSLOPE SSW
FLOW PREVAILS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 510 AM EDT SUN SEP 30 2012
AT 12Z MON THERE WILL BE AN UPPER RIDGE OVER THE CWA...WITH A
SHORTWAVE TROUGH FROM WRN HUDSON BAY TO WRN MN. AHEAD OF THE
SHORTWAVE...A SFC TROUGH WILL BE OVER WRN LAKE SUPERIOR. MODELS NOT
SHOWING MUCH MOISTURE WITH THE SYSTEM...OR MUCH QPF...BUT MOST DO
SHOW SOME LIGHT PRECIP ASSOCIATED WITH A NARROW BAND OF LOW LEVEL
MOISTURE OVER PORTIONS OF THE CWA AS THE SHORTWAVE PASSES MON INTO
MON NIGHT. WILL KEEP SLIGHT CHANCE POPS IN THE FORECAST FOR THIS TIME.
ATTENTION THEN TURNS TO A MUCH STRONGER SYSTEM THAT MODELS SHOW
ENTERING THE NRN PLAINS TUE NIGHT AND STRENGTHENING SOMEWHERE IN THE
REGION AROUND THE CWA THU. MODELS THEN SHOW REINFORCING UPPER ENERGY
AND COLD AIR MOVING IN FRI INTO THE WEEKEND. OVERALL...THE FORECAST
DURING THIS TIME IS VERY UNCERTAIN AND QUITE TRICKY. THERE IS
SUBSTANTIAL RUN TO RUN VARIABILITY WITH MOST MODELS AS WELL AS MODEL
DISAGREEMENT...SO FORECAST CONFIDENCE IS LOW. THE OVERALL IDEA SHOWN
BY MODELS IS THAT THE UPPER TROUGH WILL DEEPEN AND CLOSE OFF
SOMEWHERE IN THE REGION THU...AND THEN MOVE NE TO JAMES BAY OR
QUEBEC FRI. NW LOW LEVEL WINDS AND 850MB TEMPS AS LOW AS -8C BEHIND
THE SYSTEM WOULD BE FAVORABLE FOR LAKE EFFECT RAIN/SNOW FRI INTO
SAT. MODELS HAVE BEEN SHOWING A GENERAL NORTHERLY TREND WITH THE LOW
TRACK...MORE TOWARD THE ECMWF WHICH HAS SHOWN BETTER CONTINUITY. NOW
THE LATEST RUN OF THE GFS (00Z/30) SLOWED THE EVOLUTION OF THE
SYSTEM BY 12-18 HOURS FROM THE PREVIOUS RUN. WITH THE SYSTEM
CURRENTLY S OF THE ALEUTIAN ISLANDS AT AROUND LAT 45N LON 160W IT IS
NOT BEING SAMPLED BY TRADITIONAL UPPER AIR NETWORK...SO HOPEFULLY
CONFIDENCE WILL BE IMPROVED WHEN THE SYSTEM MOVES INTO THE
OBSERVATION NETWORK OF WRN CANADA AROUND 00Z TUE. IT IS IMPORTANT TO
POINT THAT THERE IS A VERY WIDE GAMUT OF POSSIBLE REALITIES
RESULTING FROM DIFFERENT PATHS THIS SYSTEM MAY TAKE. IF THE SYSTEM
GOES MORE S OF THE CWA...SE TO NE GALES AND A WETTER/SNOWIER
FORECAST MAY RESULT. IF THE SYSTEM GOES N OF THE CWA...W GALES AND A
DRIER FORECAST MAY RESULT...WITH THE POSSIBILITY OF THUNDERSTORMS
ALONG THE ATTENDANT COLD FRONT. IF THE SYSTEM GOES OVER THE CWA...A
COMBINATION OF THE PREVIOUS SCENARIOS MAY RESULT. OF COURSE...THERE
IS ALSO THE POSSIBILITY THAT THE SYSTEM ENDS UP BEING SIGNIFICANTLY
WEAKER (OR EVEN STRONGER) THAN WHAT THE MODELS CURRENTLY SHOW. AM
REALLY NOT CERTAIN WHAT WILL HAPPEN...BUT AM LEANING TOWARD THE NRN
TRACK OF THE MORE PERSISTENT ECMWF AND FORECAST PERSISTENCE WITH
THIS SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 133 AM EDT SUN SEP 30 2012
EXPECT MAINLY VFR CONDITIONS THIS FCST PERIOD AT ALL 3 TAF SITES
WITH DRY HI PRES OVER ONTARIO DOMINATING. WITH A LIGHT E UPSLOPE
WIND...SOME FOG MAY BE POSSIBLE AT SAW. THERE IS ALSO A CHANCE SOME MVFR
CIGS MIGHT IMPACT CMX/SAW THRU TODAY...BUT THE AIRMASS APPEARS TOO
DRY TO FCST THESE LOWER CONDITIONS ATTM.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EDT SUN SEP 30 2012
HIGH PRESSURE AND A WEAK PRESSURE GRADIENT WILL PERSIST TODAY.
SRLY WINDS WILL INCREASE INTO THE 10 TO 20 KT RANGE TONIGHT AHEAD OF
A TROUGH MOVING TOWARD THE REGION. WINDS WILL VEER TO THE WEST
MONDAY AND THEN TO THE NORTH MONDAY NIGHT BUT SHOULD REMAIN AT OR
BELOW 20 KT. HIGH PRESSURE WILL AGAIN DOMINATE TUESDAY WITH
RELATIVELY LIGHT WINDS. A LOW PRESSURE SYSTEM LIFTING INTO NORTHWEST
ONTARIO WILL PUSH A COLD FRONT THROUGH LAKE SUPERIOR THURSDAY WITH
STRONG WRLY WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC/JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
406 AM CDT SUN SEP 30 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT. MAIN FORECAST CONCERN IS
ISOLATED THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON/EVENING...
FOLLOWED BY THE PASSAGE OF A COLD FRONT SHORTLY THEREAFTER.
WEAK SURFACE HIGH PRESSURE CENTERED NEAR HILL CITY KANSAS THIS
MORNING HAS KEPT WINDS LIGHT...WITH ONLY SOME HIGH CLOUDS SCRAPING
THE SOUTHEAST 1/3 OF THE FORECAST AREA. TEMPERATURES WARMER
IN THE CLOUDY AREAS...AS OPPOSED TO CLOUD FREE REGIONS.
ONE EARLY...ALTHOUGH MINOR CONCERN...MAY BE A BIT OF FOG IN THE FAR
SOUTHWEST/WESTERN FORECAST AREA. LATEST HRRR DATA IS SHYING AWAY
FROM ANY FOG OR LOW CLOUDS IN OUR FORECAST AREA...OPTING INSTEAD
JUST TO THE WEST WHERE SOUTHERLY FLOW HAS ALLOWED FOR A LITTLE
BETTER MOISTURE RETURN. MOST LIKELY THIS STUFF WOULDN/T GET GOING
UNTIL CLOSE TO SUNRISE...SO ITS A GAME TIME DECISION WHETHER ITS
WORTH EVEN BEING PART OF THE FORECAST. RIGHT NOW...ITS NOT LOOKING
TO LIKELY TO FORM.
THE MAIN STORY REST OF THE DAY IS WHETHER THE WESTERN PART OF THE
FORECAST CAN SHARE IN SOME ISOLATED SHOWERS/THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING. WEAK SURFACE CONVERGENCE ALONG A BOUNDARY
STARTS TO PUSHING THE FAR WESTERN SECTION OF THE FORECAST ABOUT MID
AFTERNOON. THIS COINCIDES WITH NARROW AXIS OF MOISTURE AND SURFACE
INSTABILITY BRIEFLY ABOVE 1000 J/KG. STEEP MID LEVEL LAPSE RATES ALSO
SET UP. THERE LIKELY WILL BE SOME HIGH BASED SHOWERS/ISOLATED
THUNDERSTORMS FORMING JUST TO THE WEST OF THE FORECAST AREA AROUND
3-4 PM...AND THEN GRADUALLY MIGRATE EAST. HAVE CONTINUED WITH THE
20-30% CHANCE OF RAIN...NOT SO MUCH FOR UNCERTAINTY ON CONVECTIVE
ACTIVITY...BUT KEPT THINGS ON THE LOW SIDE WITH LARGE LOW
LEVEL DEWPOINT DEPRESSIONS AND CLASSIC INVERTED V SOUNDINGS. BOTH
SUGGEST LIMITED RAINFALL...BUT SOME WIND GUST POTENTIAL TO NEAR
SEVERE LEVELS. HAVE INCLUDED SOME CHANCE INTO THE EARLY EVENING
AS FAR EAST AS HIGHWAY 281...ALTHOUGH THAT MAY WELL BE STRETCHING
IT WITH STORM MOTIONS PROBABLY AROUND 10KTS OR SO. LATEST MODELS
HAVE FAVORED A LITTLE FURTHER WEST PROFILE...SO KEPT THE BEST
SHOT FOR RAIN THERE.
WELL...ONCE THAT STUFF WRAPS BY LATE EVENING...ATTENTION TURNS
TO ONCOMING COLD FRONT LATE TONIGHT AND EARLY MONDAY. PRETTY STRONG
PRESSURE RISES AS THE FRONT PASSES...SO EXPECT THE WIND TO PICK UP
PRETTY STEADY BY LATE TONIGHT. GOOD MOMENTUM TRANSFER WILL CONTINUE
ALL DAY MONDAY WITH NEARLY UNIDIRECTIONAL FLOW GIVING US THE FIRST
BREEZY/WINDY DAY...SINCE THE LAST COLD FRONT A FEW DAYS AGO. MODELS
TRY TO SQUEEZE OUT SOME LIGHT SHOWERS...PROBABLY SPRINKLES. NONE THE
LESS...HAVE WORKED IN TANDEM WITH OTHER OFFICES TO INCLUDE A SLIGHT
CHANCE OF LIGHT SHOWERS MONDAY MORNING...BEFORE SUNSHINE TAKES OVER
LATER. TEMPERATURES WILL NOT ONLY FEEL COOLER DUE TO THE NORTH
WIND...BUT ACTUALLY BE COOLER DURING THE DAY MONDAY.
NOT MUCH ELSE TO WORRY ABOUT MONDAY NIGHT THROUGH TUESDAY NIGHT...
WITH A COOL NIGHT MONDAY NIGHT...GIVING WAY TO A REALLY NICE AND
MILD DAY TUESDAY WITH SUNSHINE AND LIGHT WINDS.
.LONG TERM...12Z WEDNESDAY THROUGH SATURDAY. A COLD FRONT
PROGGED TO TRANSITION THROUGH THE REGION WEDNESDAY NIGHT INTO
THURSDAY WILL PROVE TO BE THE MOST CHALLENGING ASPECT OF THE
EXTENDED FORECAST. CHALLENGES WILL RESULT IN PRECIPITATION
TIMING/COVERAGE AND TEMPERATURES BOTH AHEAD AND BEHIND THE COLD
FRONT. PRECIP CHANCES WILL ALSO BE REALIZED TOWARDS THE END OF THE
LONG TERM.
A COLD FRONT WILL EXTEND DOWN INTO THE CENTRAL PLAINS ON THURSDAY
FROM FROM AN ASSOCIATED UPPER LEVEL TROUGH FORECAST TO PASS
THROUGH THE NORTHERN PLAINS. RETURN FLOW IN THE LOWER LEVELS AHEAD
OF THIS FRONTAL BOUNDARY SHOULD ADVECT ENOUGH MOISTURE INTO THE
CENTRAL PLAINS TO HELP AID IN THE DEVELOPMENT OF SOME STRATIFORM
RAIN ACROSS THE OUTLOOK AREA. FORECAST SOUNDINGS SUGGEST A MOIST
ATMOSPHERIC PROFILE BEGINNING AROUND MIDNIGHT ON WEDNESDAY AND
CONTINUING THROUGH THE MORNING HOURS OF THURSDAY. PRECIPITATION
TIMING WILL RELY SOLELY ON THE TIMING OF THE COLD FRONT...BUT
CURRENT ANALYSIS LEADS TO PRECIP BEGINNING LATE WEDNESDAY NIGHT AND
CONTINUING THROUGH THURSDAY MORNING BEHIND THE COLD FRONT. NO SEVERE
WEATHER IS ANTICIPATED.
THE BIGGEST CHANGE IN THE FORECAST WAS WEDNESDAY HIGH
TEMPERATURES...WHICH WILL BE NEAR 80 DEGREES AHEAD OF THE FRONT FOR
MOST OF THE OUTLOOK AREA. THIS CHANGE IS MAINLY DUE TO THE TIMING OF
THE FRONT BEING A LITTLE SLOWER THAN PREVIOUSLY FORECAST.
FURTHERMORE...850MB TEMPS ALSO SUGGEST HIGHER TEMPERATURES THAN THE
OUTPUT FROM ALLBLEND. THURSDAY HIGH TEMPERATURES AND FRIDAY MORNING
LOW TEMPERATURES HAVE BEEN RATHER TRICKY WITH THE PASSAGE OF THE
FRONTAL BOUNDARY OVER THE LAST COUPLE OF DAYS. SEEMS AS THOUGH THE
MODELS MAY HAVE FINALLY SETTLED ON A SOLUTION. THE PAST SEVERAL DAYS
HAVE SHOWN A GENERAL DECREASE IN TEMPERATURES ACROSS THE CWA FOR
THURSDAY HIGH TEMPERATURES AND THE OVERNIGHT LOWS...BUT TEMPERATURES
ARE NOW NEARLY CONSISTENT WITH THE PREVIOUS FORECAST. THURSDAY WILL
BE BELOW NORMAL FOR HIGHS AS UPPER 50S AND LOWER 60S ARE FORECAST.
IN FACT...THE REST OF THE LONG TERM IS FORECAST TO EXPERIENCE BELOW
NORMAL TEMPERATURES FOR THIS TIME OF YEAR. THURSDAY NIGHT LOW
TEMPERATURES ARE STILL FLIRTING WITH FROST POTENTIAL. WILL NEED TO
MONITOR THIS OVER THE NEXT COUPLE OF DAYS. A FROST ADVISORY
MIGHT HAVE SOME CREDIBILITY ACROSS NORTHERN PARTS OF THE CWA NEXT
WEEK.
THERE WILL BE A CHANCE FOR PRECIPITATION FRIDAY NIGHT AND INTO
SATURDAY AS ANOTHER CONVERGENCE ZONE SETS UP OVER THE CENTRAL PLAINS
WITH FORECAST SOUNDINGS SUGGESTING A MOIST ATMOSPHERIC PROFILE.
AGAIN...SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 1209 AM CDT SUN SEP 30 2012/
AVIATION...VFR CONDITIONS WILL PREVAIL THROUGHOUT THE VALID TAF
PERIOD. FORECAST SOUNDINGS SUGGEST HIGH CLOUDS WILL EXIT THE
TERMINAL SITE AROUND SUNRISE...AND A PERIOD OF CLEARER SKIES WILL
BEGIN IN THE WAKE OF AN ARRIVING COLD FRONT ON MONDAY. WIND SPEEDS
WILL BE LIGHT TODAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM....NOAA/NWS/MORITZ
LONG TERM/AVIATION...GUERRERO
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
358 AM EDT SUN SEP 30 2012
.SYNOPSIS...
LOW PRESSURE OVER THE EAST COAST WILL MOVE SLOWLY NORTHEAST AND
EXTEND A TROUGH BACK WEST OVER THE REGION THROUGH TONIGHT. HIGH
PRESSURE WILL BUILD EAST ON MONDAY ACROSS THE AREA. LOW PRESSURE
AND RESULTING WARM FRONT WILL LIFT NORTH ACROSS THE REGION ON
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE UPPER LOW OVER THE EASTERN GREAT LAKES EARLY THIS MORNING WILL
MOVE SOUTHEAST TODAY. THE BIG QUESTION IS WHAT KIND OF POP IS NEEDED
FOR NE OH AND NW PA AND HOW FAR WEST TO CARRY A THREAT. THE HRRR
MODEL REALLY DECREASES THE THREAT BY DAYBREAK. WITH THE INSTABILITY
SO STRONG THE LAKE AND 500 MB TEMPERATURE DIFFERENCE NEAR 43C FROM
LAKE COUNTY EAST TODAY...WILL KEEP THE LIKELY POPS GOING THROUGH
EARLY TO MID AFTERNOON AND THEN DECREASE THEM AS SUBSIDENCE OCCURS
BEHIND THE VORT MAX. THE HRRR IS NOW KEEPING SHOWERS GOING LONGER
INTO THE AFTERNOON WHICH SEEMS GOOD WITH SOME MUCH INSTABILITY. MOST MODELS
AGREE WITH THIS. CONFIDENCE IS MODERATE. AS PER THE HRRR MODEL AND
SOME SHOWERS ON LAKE HURON WILL HAVE A THREAT OF SHOWERS AS FAR
WEST AS THE ISLANDS. USED A BLEND OF GUIDANCE FOR THE
HIGHS...COOLER EAST BECAUSE OF THE CLOUDS AND SHOWERS AND WARMER
WEST WITH SOME SUNSHINE THIS AFTERNOON.
WILL MENTION OF THREAT OF SMALL HAIL IN EXTREME NE OH AND NW PA
AND WATERSPOUTS OVER THE EAST END OF THE LAKE. THIS WILL BE IN
GRIDS AND THE HWO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE WILL BE BUILDING IN BUT WITH THE LAKE AND 850 MB
TEMPERATURE DIFFERENCE NEAR 13C SOME LAKE ENHANCED SHOWERS MAY
OCCUR. THE BEST CHANCE WOULD BE NW PA WHERE THE MOISTURE IS A LITTLE
BETTER...ESPECIALLY EARLY TONIGHT. ELSEWHERE SOME CIRRUS WILL BE
MOVING IN FROM THE SOUTHWEST. THIS MAY HELP LIMIT ANY WIDESPREAD
DENSE FOG FROM DEVELOPING...SO WILL NOT MENTION IT AT THIS TIME.
WATCHING THE NEXT WEATHER MAKER FOR THE REGION FROM THE GULF OF
MEXICO. THE 00Z ECMWF IS VERY QUICK WITH THIS SYSTEM...DIDN`T GO AS
FAST AS THE ECMWF BUT DID SPEED THE TIMING OF THE SHOWERS A LITTLE
BIT. LIKELY LOOKS GOOD MONDAY NIGHT INTO TUESDAY AND THEN CHANCE
AFTER THAT AS WE GET CLOSE TO THE WARM SECTOR. AT THIS TIME NO
MENTION OF THUNDER BUT A THREAT WILL EVENTUALLY HAVE TO BE
MENTIONED. NOT CONFIDENT ENOUGH TO FORECAST IT AT THIS TIME.
USED A BLEND OF THE GUIDANCE BUT WITH PLENTY OF CLOUDS AND SHOWERS
AROUND WENT COOLER FOR THE HIGHS AND WARMER FOR THE LOWS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE PERIOD WILL START OUT DRY ON THURSDAY AS THE AREA WILL BE
BETWEEN WEATHER SYSTEMS. MODELS CONTINUE TO MOVE NEXT COLD FRONT
ACROSS THE AREA ON FRIDAY. ECMWF CONTINUES TO BE THE FASTER OF THE
2 MODELS. ECMWF HAS THE FRONT JUST EXITING THE AREA BY 12Z FRIDAY
WHILE THE GFS JUST HAS THE FRONT INTO NW OH. CONTINUED TO USE THE
SLOWER GFS FOR FORECAST. MODELS DIFFER SIGNIFICANTLY ON SATURDAY.
ECMWF HAS ANOTHER STRONG COLD FRONT PUSHING ACROSS THE AREA ON
SATURDAY. GFS ON OTHER HAND HAS LARGE LOW SETTING UP OVER JAMES BAY
WITH A SERIES OF TROUGHS SWINGING ACROSS EASTERN LAKES. FOR NOW
WILL CONTINUE WITH THE GFS SOLUTION. LEFT CHANCE POPS SNOWBELT EAST
OF CLEVELAND FOR SATURDAY WITH TROUGH AND IN ADDITION 850 MB TEMPS
DIP TO MINUS 4C SETTING UP POTENTIAL FOR LAKE EFFECT SHOWERS.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
SURFACE TROUGH SWINGING ACROSS EASTERN PORTION OF FORECAST AREA
NOW KICKING OFF A FEW SHOWERS. WILL BE A BRIEF RESPITE...THEN
UPPER LEVEL VORTICITY MAX NOW OVER LAKE HURON WILL SWING ACROSS
THE AREA SHORTLY AFTER SUNRISE. THIS WILL ALSO KICK OFF A FEW
SHOWERS...BUT DO NOT THINK IT WILL BE ANY WORSE THAN MVFR
CONDITIONS IN THE HEAVIER SHOWERS. AGAIN MOST SHOWERS WILL BE FROM
CLEVELAND EAST. SKIES WILL BEGIN TO SCATTER OUT FROM THE NORTH BY
MID AFTERNOON AS THE VORT MAX SWINGS SOUTH OF THE AREA.
.OUTLOOK...NON-VFR CONDITIONS PROBABLE TUESDAY INTO WEDNESDAY IN
SHRA.
&&
.MARINE...
FLOW WILL BECOME NORTHEAST TODAY BUT CONDITIONS WILL STAY BELOW
SMALL CRAFT ADVISORY CRITERIA. NE FLOW WILL CONTINUE ON SUNDAY AND
THEN BECOME NORTHERLY ON SUNDAY NIGHT AS HIGH PRESSURE BRIEFLY
RETURNS. LOCAL SCHEMES SHOWING A GOOD CHANCE FOR WATERSPOUTS ON
SUNDAY. BEST CHANCES FOR THIS WILL BE TO THE EAST OF CLEVELAND AND
ANYWHERE A DECENT SHOWER DEVELOPS. LOW PRESSURE STILL FORECAST TO
MOVE ACROSS THE OHIO VALLEY ON TUESDAY...AND ACROSS LAKE ERIE
TUESDAY NIGHT. MODELS STILL NOT IN GOOD AGREEMENT ON EXACT TRACK
AND TIMING.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1043 AM EDT SUN SEP 30 2012
.SYNOPSIS...
A BROAD UPPER LEVEL STORM SYSTEM IMPACTS THE NORTHEAST INTO
MONDAY. WEAK HIGH PRESSURE BUILDS IN MONDAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM...WHICH WILL PASS THROUGH MID
WEEK. HIGH PRESSURE BRIEFLY BUILDS IN THE END OF THE WEEK BEFORE
THE NEXT FRONT APPROACHES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST WATER VAPOR AND RUC ANALYSIS SHOW CUTOFF LOW ALOFT CENTERED
NEAR THE WESTERN NY/PA BORDER...WITH A 33 UNIT 500 HPA VORTICITY
MAXIMUM JUST S OF LONG ISLAND LIFTING NE. AHEAD OF THIS VORTICITY
MAXIMUM - STRONG POSITIVE VORTICITY ADVECTION - THERE ARE ISOLD-
SCT SHRA...AND BEHIND IT - NEGATIVE VORTICITY ADVECTION - DRY
CONDITIONS WITH AT MOST FEW-SCT CLOUD COVERAGE.
THE NEXT VORTICITY MAXIMUM APPROACHES WESTERN ZONES BY LATE
AFTERNOON...SO INTRODUCE ISOLD-SCT SHRA THERE.
SHOWALTER INDICES AROUND TO JUST BELOW 0 ARE FORECAST ACROSS THE
NORTHERN AND FAR EASTERN PORTIONS OF THE CWA THIS AFTERNOON...SO
HAVE ISOLATED THUNDER IN FOR THOSE LOCATIONS.
A BLEND OF NAM/SREF/HRRR POPS REFLECTS PRECIPITATION TREND FAIRLY
WELL...THOUGH MIGHT BE UNDER DOING AREA TO BE MAINLY DRY LATE THIS
MORNING INTO THIS AFTERNOON. CMC-REG SKY PRODUCT CAPTURES CURRENT
AREA OF MAINLY SKC FROM NJ BACK INTO EASTERN PA...SO HAVE USED IT
TO UPDATE SKY GRIDS...RESULTING IN A SIGNIFICANT DECREASE IN CLOUD
COVER FORECAST...ESPECIALLY FOR SOUTHERN ZONES.
12Z KOKX AND KALY SOUNDINGS SUGGEST HIGHS RANGING FROM THE LOWER
60S ACROSS THE NORTHERN INTERIOR TO THE MID-UPPER 60S NEAR THE
COAST. THIS IS CONSISTENT WITH A BLEND OF 6Z MAV/NAM 2-METER
TEMPERATURES WITH 00Z MET GUIDANCE. HOURLY AND HIGH TEMPERATURE
GRIDS ADJUSTED ACCORDINGLY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
DRYING CONDITIONS THIS PERIOD AS THE UPPER LEVEL LOW FINALLY
PUSHES OFF TO THE NORTHEAST...ALLOWING FOR RIDGING TO BUILD IN ON
MONDAY. THE SURFACE LOW MOVES OFF TO THE NORTH AS WELL...DRAGGING
A TROUGH THROUGH THE CWA...RESULTING IN A MORE WESTERLY FLOW TO
THE WEST...AND A SOUTHWESTERLY FLOW OVER THE EAST. A TIGHTENING
PRESSURE GRADIENT BETWEEN THE DEPARTING LOW AND APPROACHING HIGH
FROM THE SOUTH WILL INCREASE WINDS LATE SUNDAY NIGHT INTO
MONDAY...WITH GUSTS BETWEEN 15 AND 20 MPH POSSIBLE. SOUNDINGS
INDICATE DRYING AT ALL LEVELS AS THE LOW MOVES AWAY AND COOLER AIR
IS USHERED IN ON THE BACKSIDE OF THE LOW...CREATING PLENTY OF SUBSIDENCE
FOR MONDAY. OTHER THAN A FEW LINGERING SHOWERS THIS
EVENING...SHOULD HAVE A DRY FORECAST UNTIL MONDAY NIGHT WHEN THE
FLOW RETURNS TO THE SOUTH AND THE MOISTURE FIELD BEGINS
INCREASING.
GFS THE WARMEST WITH TEMPS WITH IT PUSHING THE LOW OUT THE
QUICKEST. SIDED WITH THE SLIGHTLY SLOWER NAM GUIDANCE FOR
TEMPS...WHICH KEEPS TEMPS NEAR NORMAL. IF SKIES CLEAR QUICKER THAN
FORECASTED...COULD SEE TEMPS DROP ANOTHER COUPLE OF DEGREES...ESP
INLAND.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
OVERALL...UNSETTLED WEATHER STILL FORECASTED FOR MID WEEK...WITH
A BREAK IN THE PRECIPITATION POSSIBLE THURS/FRI. WHILE MODEL
DISCREPANCIES ARE STILL IN PLACE...THERE IS SOME BETTER ALIGNMENT
WITH THE 00Z RUNS...ALLOWING FOR SLIGHTLY HIGHER CONFIDENCE ON THE
FORECAST.
WEAK HIGH PRESSURE AT THE SURFACE BEGINS TO RETREAT TUESDAY AS A
WARM FRONT ASSOCIATED WITH A SURFACE LOW OVER THE OHIO RIVER
VALLEY APPROACHES AND MOVES THROUGH THE NORTHEAST. DESPITE
DIFFERENCES IN THE EXACT TIMING...GENERAL MODEL CONSENSUS IS A TAD
SLOWER WITH THE PROGRESSION OF THE LOW AND ITS ASSOCIATED
FRONTS. 00Z NAM REMAINS THE MAIN OUTLIER WITH TIMING...REALLY
SLOWING EVERYTHING DOWN TILL WED. HOWEVER...DECIDED TO SIDE WITH
THE MORE CONSISTENT AND PROGRESSIVE PATHS...BRINGING THE
PRECIPITATION IN BY TUES NIGHT. KEPT CHANCE POPS IN FOR TUES
MORNING WITH INCREASING WAA/MOISTURE FIELD...THEN INCREASED POPS
THROUGHOUT THE DAY INTO TUES NIGHT ALONG THE ISENTROPIC LIFT. ALSO
TIMED PRECIPITATION OUT TO CORRESPOND WITH PASSING SHORTWAVES
ALONG THE NORTHERN FRINGE OF THE UPPER LEVEL RIDGE.
CHANCE OF PRECIPITATION REMAINS MENTIONED THROUGH WED ALONG THE
PASSAGE OF THE COLD FRONT/SURFACE LOW. HOWEVER...WITH RIDGING IN
PLACE ALOFT...EXPECT THINGS TO DRY OUT RATHER QUICKLY ONCE THE
FRONT PASSES. SURFACE HIGH PRESSURE BUILDS IN FROM THE SOUTH THURS
INTO FRI...WHICH SHOULD KEEP THE DRY WEATHER IN PLACE. ANOTHER
STORM SYSTEM IS EXPECTED TO IMPACT THE AREA THIS WEEKEND...BUT
TIMING IS STILL UNCERTAIN AT THIS TIME. THUS...CONTINUED PREVIOUS
FORECAST FOR THE END OF THE WEEK DUE TO THESE UNCERTAINTIES.
WAA AHEAD OF THE COLD FRONT MID WEEK WILL PUSH TEMPS BACK TO ABOVE
NORMAL TUES THROUGH THURS...WITH CLOUDY CONDITIONS AND RAIN
MODERATING TEMPS. SLIGHT COOLING SETTLES IN FRI...BUT THE NEXT
BURST OF COOLER AIR LOOKS TO BE AFTER THE FRONT THIS WEEKEND.
GENERALLY WENT WITH A BLEND OF HPC/MOS GUIDANCE FOR TEMPS AND DEW
POINTS.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
LOW PRES E OF CAPE COD WILL CONTINUE TO TRACK N TODAY.
LIGHT N/NW FLOW WILL BACK TO THE WNW THIS AFTN. SPEEDS WILL
INCREASE INTO THE 10-15KT RANGE AFT 18Z.
VFR IS OVERSPREADING THE REGION FROM THE SW. THIS TREND IS
EXPECTED TO CONTINUE. CU IS EXPECTED TO BEGIN TO DEVELOP IN THE
16-18Z PERIOD. ISOLD-SCT SHRA ARE POSSIBLE...HOWEVER THE BULK OF
THIS ACTIVITY IS PROGGED TO BE N OF THE CITY TERMINALS. ANY SHRA
DISSIPATE BY 23-00Z.
TONIGHT...WINDS REMAIN FROM THE WEST AROUND 10 KT OR LESS WITH VFR
CONDITIONS.
OUTLOOK FOR 12Z MONDAY-THURSDAY...
.MONDAY-MONDAY NIGHT...VFR. GUSTS ARE POSSIBLE DURING THE DAY MONDAY.
.TUESDAY-WEDNESDAY...MVFR OR LOWER CONDITIONS POSSIBLE IN SHRA.
.WEDNESDAY NIGHT-THURSDAY...VFR.
&&
.MARINE...
MINOR CHANGES MADE IN THE GRIDS TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
SUB-SCA CONDITIONS TODAY WITH A NORTHERLY TO WESTERLY FLOW BETWEEN
5 AND 10 KTS. AS THE LOW DEPARTS TOMORROW AND THE HIGH BUILDS
IN...TIGHTENING PRESSURE GRADIENT WILL INCREASE BOTH WINDS AND
SEAS...WITH POSSIBLE GUSTS UP TO 25 KTS. THE PERSISTENT FLOW COULD
INCREASE SEAS TO 5 FT ON THE OCEAN WATERS.
WINDS AND SEAS DIMINISH BY TUESDAY AND SHOULD REMAIN SUB SCA FOR
THE REMAINDER OF THE FORECAST. OCCASIONAL HIGHER GUSTS POSSIBLE
WITH THE PASSAGE OF THE FRONT ON WED.
&&
.HYDROLOGY...
SIGNIFICANT PRECIPITATION IS NOT EXPECTED THROUGH SUNDAY NIGHT.
A PROLONGED PERIOD OF STRATIFORM RAIN IS POSSIBLE FROM LATE
MONDAY NIGHT INTO WEDNESDAY. SINCE THIS WILL BE A LONG DURATION
EVENT AND HEAVY RAIN IS NOT EXPECTED AT THIS TIME...FLOODING DOES
NOT APPEAR TO BE A CONCERN.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SEARS
NEAR TERM...MALOIT
SHORT TERM...SEARS
LONG TERM...SEARS
AVIATION...BC/JMC
MARINE...MALOIT/SEARS
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS MIAMI FL
1022 AM EDT SUN SEP 30 2012
.UPDATE...BASED ON CURRENT TRENDS AND OBSERVATIONS, DO NOT PLAN TO
MAKE ANY CHANGES WITH THE MORNING UPDATES. THE 12Z MFL SOUNDING
WAS CONTAMINATED IN THE LOWEST LEVELS SO THE PWAT VALUE WAS
CALCULATED WAY TOO LOW. HOWEVER, IT DOES SHOW A GENERAL INCREASE
IN MOISTURE THROUGH THE MID LEVELS AND BASED ON THIS IT APPEARS
THE PWAT HAS PROBABLY INCREASED BACK CLOSE TO TWO INCHES. IT
DEPICTS ONLY A MARGINALLY UNSTABLE AIRMASS SO THE 30-40 PERCENT
POPS LOOK REASONABLE. THE HRRR DOES INDICATE NNW STORM MOTION WITH
SCATTERED COVERAGE AND THIS ALSO SEEMS REASONABLE GIVEN ABOVE
DISCUSSION.
KOB
&&
.PREV DISCUSSION... /ISSUED 727 AM EDT SUN SEP 30 2012/
AVIATION...ISOLATED SHRA MOVING NW THROUGH THE ATLC WATERS AND
GULF WATERS AT THIS TIME WITH THE ACTIVITY OCCASIONALLY MOVING
UPON THE E COAST. HAVE VCSH INITIALLY IN E COAST TAFS AND VERY
BRIEF MVFR CIG POSSIBLE. CURRENT E COAST SURFACE WINDS CALM TO
LIGHT SE WITH SEA BREEZE INCREASING SE 10 TO 12 KNOTS AFT 16Z.
TSRA TO DEVELOP MAINLY ALONG THE SEA BREEZE WITH VCTS IN TAFS AFT
17/18Z. TSRA MAY BE FAR ENOUGH INLAND TO AFFECT ONLY KTMB AND
KPBI. AT KAPF ...SHRA SHOULD REMAIN OFFSHORE WITH VCTS IN TAFS AFT
18Z THROUGH 30/00Z. AT KAPF CURRENT SURFACE WIND CALM BECOMING
ESE-SE < 10 KNOTS AFT 13Z THEN SSW-SW TO 10 KNOTS AFT 16Z AS W
COAST SEA BREEZE DEVELOPS.
PREV DISCUSSION... /ISSUED 307 AM EDT SUN SEP 30 2012/
.POTENTIAL FOR HEAVY RAIN AND LOCALIZED FLOODING ACROSS SOUTH FLORIDA MONDAY AND TUESDAY...
DISCUSSION...
WATER VAPOR ANALYSIS FROM THIS MORNING SHOWED A LARGE UPPER LOW
SPINNING OVER THE LOWER GREAT LAKES...AND ANOTHER CUT OFF LOW OVER
OKLAHOMA. UPPER LEVEL HIGH PRESSURE WAS LOCATED ACROSS THE PACIFIC
AND WEST COAST AND OUT ACROSS THE WESTERN ATLANTIC. AT THE
SURFACE...LOW PRESSURE WAS LOCATED ACROSS EAST TEXAS AND A WEAK
FRONT WAS ACROSS THE SOUTHEAST AND INTO THE WESTERN ATLANTIC. A WEAK
RIDGE AXIS WAS LOCATED FROM THE WESTERN ATLANTIC ACROSS THE LAKE
OKEECHOBEE REGION. FOR SOUTH FLORIDA...LOW LEVEL SOUTHEAST FLOW HAS
BEGUN...BUT DEEP MOISTURE WAS STILL LOCATED OVER THE CARIBBEAN. SOME
DRIER AIR WAS ALSO NOTED OVER THE YUCATAN NORTHEASTWARD TO OFF WEST
COAST OF SOUTH FLORIDA.
A SHORTWAVE IS EXPECTED TO DIVE SOUTHEAST ACROSS THE PACIFIC
NORTHWEST...AND THE CUT OFF LOW IS EXPECTED TO DEEPEN ACROSS THE
ARKLATEX REGION. THIS WILL AMPLIFY THE UPPER PATTERN THROUGH THE
MIDDLE OF THE WEEK...WITH A DEEP TROUGH ACROSS THE SOUTH AND STRONG
RIDGES ACROSS THE WEST COAST AND OVER THE WESTERN ATLANTIC. DEEP
SOUTH TO SOUTHWEST FLOW WILL DEVELOP OVER SOUTH FLORIDA...PULLING
TROPICAL MOISTURE OUT OF THE CARIBBEAN OVER THE REGION LATE TONIGHT
THROUGH TUESDAY. SINCE MODELS HAVE SLOWED DOWN THE TIMING OF THE
DEEP TROPICAL MOISTURE UNTIL TONIGHT...AND WITH WARM AND DRY AIR
ALOFT...500MB TEMPS AROUND -4C TO -5C...CUT BACK POPS SLIGHTLY
FOR TODAY. WENT WITH A BLEND OF MAV AND ECMWF FOR THE POPS...WITH
STILL A CHANCE OF STORMS ACROSS THE REGION. EXPECT MAINLY SEA
BREEZE ACTIVITY...WITH OVERALL STORM MOTION SLOW TO THE NORTH.
THE UPPER LOW OVER THE NORTHEAST CONUS WILL SLOWLY SLIDE TO THE
NORTHEAST...AND SURFACE LOW PRESSURE WILL MOVE ACROSS THE NORTHERN
GULF AND INTO THE SOUTHEAST STATES EARLY NEXT WEEK. A COLD FRONT
ATTACHED TO THE SURFACE LOW WILL MOVE INTO THE CENTRAL/EASTERN
GULF ON MONDAY AND THEN INTO CENTRAL FLORIDA AND NEAR LAKE
OKEECHOBEE ON TUESDAY.
SO FOR MONDAY...PWATS WILL INCREASE TO AROUND 2.1-2.4
INCHES...AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. ALTHOUGH STORM
MOTION IS NOT TERRIBLY SLOW...AROUND 10 KNOTS TO THE
NORTHEAST...WITH THE DEEP MOISTURE AND SATURATED SOILS ACROSS SOUTH
FLORIDA THERE WILL A POTENTIAL FOR LOCALLY HEAVY RAINFALL. HPC
PAINTS AROUND 1 INCH OF RAIN AREAL AVERAGE ACROSS THE ENTIRE
EASTERN TWO-THIRDS OF SOUTH FLORIDA...SO LOCALIZED SPOTS COULD
SEE 2 TO 4 INCHES OF RAIN AND POSSIBLY MORE. SO LOCALIZED
FLOODING IS THE BIGGEST CONCERN. FLASH FLOOD GUIDANCE IS NOT STILL
RELATIVELY HIGH...3-4 INCHES FOR 1 HOUR...AROUND 4 INCHES FOR 3
HOURS...AND 4-5.5 INCHES FOR 6 HOURS. WITH NO REAL FOCUS FOR
STORMS AND CLOUD COVER POSSIBLY HAMPERING OVERALL ACTIVITY...WILL
NOT ISSUE A FLOOD WATCH AT THIS TIME. WENT BELOW GUIDANCE BY A FEW
DEGREES FOR HIGH TEMPERATURES DUE TO EXPECTED CLOUD COVER AND
RAINFALL ON MONDAY.
SOME OF THE DRIER AIR PREVIOUSLY MENTIONED ACROSS THE
EASTERN GULF AND TOWARDS THE YUCATAN MAY TRY TO PUSH INTO THE GULF
COAST OF SOUTH FLORIDA MONDAY NIGHT DUE TO THE SOUTHWEST FLOW
ALOFT. HOWEVER...HIGH PRESSURE ACROSS THE WESTERN ATLANTIC WILL
BEGIN TO STRENGTHEN AND BATTLE BACK AGAINST THE TROUGH OVER THE
SOUTH...AND THE DEEP MOISTURE IS FORECAST TO PUSH BACK ACROSS AT
LEAST THE EASTERN TWO-THIRDS OF THE REGION ON TUESDAY. HEIGHTS
WILL BEGIN TO RISE ACROSS THE REGION...BUT THERE WILL BE ANOTHER
CHANCE FOR LOCALLY HEAVY RAINFALL...MAINLY FOR THE EAST COAST
METRO AREAS.
HIGH PRESSURE WILL CONTINUE TO STRENGTHEN ACROSS THE WESTERN
ATLANTIC TUESDAY NIGHT INTO WEDNESDAY WITH HEIGHTS OF 596-598
DECAMETERS...AND 592-593 DECAMETERS ACROSS SOUTH FLORIDA. THE FLOW
WILL BECOME MORE SOUTHEASTERLY AS HIGH PRESSURE BUILDS IN...AND THE
DEEP MOISTURE WILL BEGIN TO GET PUSHED TO THE NORTHWEST. PWATS WILL
FALL TO 1.8 TO 2 INCHES ACROSS THE REGION...HIGHEST ACROSS THE
NORTHWEST. THE PERSISTENT TROUGH OVER THE DEEP SOUTH WILL BEGIN TO
LIFT TO THE NORTHEAST AS ANOTHER TROUGH DIGS INTO THE NORTHERN
PLAINS ON THURSDAY...AND HIGH PRESSURE WILL BEGIN TO WEAKEN OVER THE
WESTERN ATLANTIC. SURFACE HIGH PRESSURE WILL DEVELOP OVER THE
SOUTHEAST AND EASTERLY FLOW WILL DEVELOP ACROSS THE REGION...WITH
MORE TYPICAL SEA BREEZE TYPE CONVECTION. HOWEVER...A WEAK BOUNDARY
WILL REMAIN OVER CENTRAL FLORIDA OR NEAR LAKE OKEECHOBEE...KEEPING
RELATIVELY HIGH LEVELS OF MOISTURE...PWATS NEAR 2 INCHES...INTO THE
WEEKEND. SO RAIN CHANCES WILL REMAIN AT OR ABOVE NORMAL THROUGH NEXT
SATURDAY. TEMPERATURES ARE EXPECTED TO REMAIN NEAR NORMAL THROUGH
THE PERIOD.
AVIATION...FOR 06Z TAFS.
WIDELY SCATTERED SHRA MOVING NW THROUGH THE
ATLC WATERS AND GULF WATERS WITH THE ACTIVITY OCCASIONALLY MOVING
UPON THE E COAST. VERY BRIEF MVFR CIG POSSIBLE. VCSH IN E COAST
TAFS. E COAST SEA BREEZE INCREASES SE WINDS AFT 16Z AND TSRA TO
DEVELOP MAINLY ALONG THE SEA BREEZE WITH VCTS IN TAFS. POTENTIAL
THAT TSRA MAY BE FAR ENOUGH INLAND TO AFFECT MAINLY KTMB AND KPBI.
AT KAPF...SHRA SHOULD REMAIN OFFSHORE WITH VCTS AFT 18Z THROUGH
30/00Z. E COAST SURFACE WINDS CURRENTLY CALM TO SE-SSE < 5 KNOTS
UNLESS BECOMING VARIABLE FOR A SHORT PERIOD OF TIME IF A SHRA
MOVES OVER THE AREA...BECOMING SE 10-12 KNOTS AFT 15Z. AT KAPF
CURRENT SURFACE WIND CALM TO SE < 5 KNOTS INCREASING AFT 12Z 5 TO
8 KNOTS THEN SHIFTING SSW-SW TO 10 KNOTS AFT 16Z AS W COAST SEA
BREEZE DEVELOPS.
MARINE...
WIND AND SEAS WILL REMAIN QUITE TRANQUIL THROUGH THE
WEEKEND WITH LIGHT SOUTHEAST FLOW BECOMING MORE SOUTHERLY ON
SUNDAY. A STRONGER SOUTH WIND WILL BEGIN TO DEVELOP MONDAY AND
TUESDAY IN RESPONSE TO THE DEVELOPING LOW PRESSURE WITH SEAS
POSSIBLY BUILDING TO AROUND 4 FEET.
FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH HIGH LOW LEVEL MOISTURE IN PLACE THIS
WEEKEND AND ALL OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 77 87 77 / 30 30 70 50
FORT LAUDERDALE 89 76 86 77 / 30 40 70 50
MIAMI 88 78 86 77 / 30 40 70 50
NAPLES 89 77 89 77 / 20 20 60 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
904 AM CDT SUN SEP 30 2012
.DISCUSSION...
338 AM CDT
MAIN FORECAST CHALLENGES THIS MORNING ARE WITH LAKE EFFECT CLOUD
POTENTIAL NOW THROUGH LATE MORNING TODAY...WITH MOSTLY SUNNY SKIES
THEN EXPECTED FOR THE ENTIRE AREA INTO THE AFTERNOON AS TEMPS RISE
TO THE UPPER 60S AND LOW 70S.
LATEST WATER VAPOR IMAGERY DEPICTING A FAIRLY STRONG PIECE OF MID
LEVEL ENERGY WRAPPING AROUND THE CLOSED UPPER LEVEL SYSTEM ACROSS
THE EASTERN GREAT LAKES REGION THIS MORNING. AS THIS
OCCURS...COLDER AIR WILL CONTINUE TO WORK ITS WAY SOUTHWEST OVER
THE LAKE THIS MORNING AND ACROSS THE CWA THROUGH THE AFTERNOON.
WHAT THIS WILL MEAN FOR TODAY IS SLIGHTLY COOLER HIGH TEMPERATURES
ACROSS THE CWA AS WELL AS THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER TO SPILL INTO AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS AND
NORTHWEST INDIANA. AS WAS EXPECTED...LATEST RAP ANALYSIS SHOWING
DELTA TS FINALLY INCREASING ACROSS THE ENTIRE LENGTH OF THE
LAKE...WITH THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING. ALTHOUGH LATEST SATELLITE IMAGERY SHOWING THIS CLOUD
COVER SOMEWHAT SLOW TO DEVELOP OVER THE NORTHERN PORTIONS OF THE
LAKE...SHOULD BEGIN TO SEE AN INCREASE IN THIS DEVELOPMENT OVER
THE NEXT TWO TO THREE HOURS. FAVORED LOW LEVEL FLOW SHOULD KEEP
MOST OF ANY CLOUD COVER OVER AREAS IN FAR NORTHEAST ILLINOIS...BUT
WITH SOME CLOUD COVER TO STILL POSSIBLY SPILL OVER INTO AREAS IN
FAR NORTHWEST INDIANA. ALTHOUGH THIS CLOUD COVER IS EXPECTED TO
DEVELOP AND MOVE ACROSS AREAS NEAR THE LAKE...IT SHOULDNT BE MORE
THAN PARTLY CLOUDY SKIES WITH SOME BRIEF PERIODS OF PARTLY
SUNNY/CLOUDY CONDITIONS THROUGH THE 15Z TIME FRAME. AFTER THIS
TIME FRAME...CLOUD COVER SHOULD BEGIN TO DIMINISH INTO THE
AFTERNOON AS HIGHER PRESSURE SHIFTS DOWN THE LAKE. AFTER THIS
POINT...SKIES SHOULD BE MOSTLY SUNNY INTO THE AFTERNOON WITH
ANOTHER PLEASANT DAY IN STORE. ALTHOUGH TEMPS TODAY WILL BE
SLIGHTLY COOLER THAN YESTERDAY...I DID RAISE TEMPS A COUPLE OF
DEGREES OVER GUIDANCE WITH TEMPERATURES RISING INTO THE LOW 70S
FOR MOST AREAS IN NORTHERN ILLINOIS...WITH TEMPS SLIGHTLY COOLER
IN THE UPPER 60S IF NOT AROUND 70 MARK FOR AREAS NEAR THE LAKE.
NONETHELESS...A PLEASANT DAY WILL BE IN STORE FOR THE AREA TODAY.
AFTER QUIET CONDITIONS ONCE AGAIN TONIGHT INTO THE EARLY PORTIONS
OF MONDAY...A SOMEWHAT MORE ACTIVE WEATHER APPEARS TO BE ON THE
HORIZON. AS MID AND HIGH LEVEL CLOUD INCREASES FROM THE SOUTH ON
MONDAY...TEMPS SHOULD STILL RISE INTO THE LOW 70S ON MONDAY.
ALTHOUGH AS WAS EXPECTED OVER THE LAST 24 HOURS...MODELS CONTINUE
TO TREND TOWARDS BRINGING CURRENT CLOSED UPPER LEVEL LOW OVER THE
SOUTHERN PLAINS NORTHEAST TOWARDS THE AREA BY LATE MONDAY. MODEL
CONSENSUS SEEMS TO BRING THIS UPPER LEVEL SYSTEM AND SURFACE
REFLECTION UP THROUGH THE TENNESSEE VALLEY LATE MONDAY INTO EARLY
TUESDAY MORNING...AS A SEPARATE MID LEVEL TROUGH APPROACHES FROM
THE NORTHERN PLAINS. ALTHOUGH WITH A LACK OF MOISTURE WITH THIS
NORTHERN STREAM MID LEVEL TROUGH...PRECIP SHOULD BE DIMINISHING AS
IT APPROACHES THE CWA. BEST CHANCES FOR SHOWERS WILL BE FOR AREAS
ACROSS THE SOUTHEAST CWA MONDAY NIGHT. THIS SYSTEM WILL SLOWLY
SPIN ACROSS THE REGION...WITH PRECIP POSSIBLY LINGERING ACROSS
THE SAME AREA TUESDAY INTO TUESDAY NIGHT. CURRENT FORECAST KEEPS
PRECIP CHANCES THROUGH LATE IN THE DAY TUESDAY...BUT ITS
CONCEIVABLE THAT THIS SYSTEM WILL TAKE A SLOWER EASTWARD MOVEMENT.
IF THIS WERE TO OCCUR...PRECIP COULD LINGER INTO THE MIDDLE PART
OF THE WEEK BEFORE EXITING. AFTER WEAK RIDGING AND A SLIGHT
INCREASE IN TEMPS ON WEDNESDAY...ANOTHER MID LEVEL SYSTEM AND
SURFACE REFLECTION/FRONTAL BOUNDARY WILL APPROACH THE CWA WITH
PRECIP CHANCES INCREASING ONCE AGAIN TOWARDS THE END OF THE WORK
WEEK. IT WOULD APPEAR THAT MAINLY SHOWERS SHOULD BE OBSERVED AS
THIS SYSTEM PUSHES THROUGH THE AREA ON THURSDAY...BUT WITH SOME
UNCERTAINTY AS TO THE OVERALL AMOUNT OF MOISTURE/INSTABILITY
PRESENT OUT AHEAD OF IT. IF THE ECMWF WERE TO VERIFY...THEN
PRIMARILY SHOWERS WOULD BE OBSERVED. IN CONTRAST...THE GFS SEEMS
TO BE MORE AGGRESSIVE WITH DEWPOINTS AND IF THIS WERE TO
OCCUR...THEN THUNDERSTORMS COULD BE PRESENT OUT AHEAD OF THIS
SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE EFFECT CIGS BECMG MVFR INTO EARLY AFTERNOON...INITIALLY MAY
BE BRIEFLY BELOW 2 KFT...BUT SHOULD QUICKLY LIFT TO 2-2.5 KFT.
* NORTHEAST WINDS BECOMG GUSTY TO G15KT BY LATE MORNING.
* SMALL CHANCE FOR MVFR CIGS TONIGHT AND EARLY MONDAY MORNING.
KREIN
//DISCUSSION...UPDATED 12Z...
THE TERMINALS LIE BETWEEEN A COLD FRONT TO THE SOUTH WHICH PASSED
LATE YESTERDAY AND HIGH PRESSURE ACROSS ONTARIO AND QUEBEC. THE
GRADIENT BETWEEN THESE FEATURES WILL CONTINUE TO FAVOR A NORTHEAST
SYNOPTIC WIND. INITIALLY...THROUGH 14Z...A SLIGHTLY MORE NNW WIND
WILL BE SEEN ACROSS NORTHEAST IL DUE TO A REMNANT LAND BREEZE FROM
THE NIGHT. THIS IS AIDING CONVERGENCE INTO NORTHEAST IL THAT
SHOULD HELP TO FOCUS DEVELOPING CLOUDS OVER THE LAKE INTO
NORTHEAST IL BY MID MORNING...AND LIKELY TOWARD GYY AS WELL. THESE
LAKE ENHANCED CLOUDS ARE PRESENTLY FAVORED TO BE AT OR ABOVE 2000
FT BY THE TIME THEY ARRIVE AT THE TERMINALS...BUT AT ONSET SOME
COULD BE BELOW 2000 FT. THAT SHOULD BE BRIEF IF THAT OCCURS.
CLOUDS SHOULD GRADUALLY BECOME MORE SCATTERED THROUGH THE
AFTERNOON AS THE COLD AIR ADVECTION COMPONENT OVER THE WATER
WEAKENS. THE HIGH PRESSURE WILL SETTLE SOUTHWARD OVER THE AREA
THIS EVENING...WITH RETURN FLOW DEVELOPING ON MONDAY.
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN BROKEN CLOUDS BETWEEN 2000 AND 3500 FT.
MEDIUM CONFIDENCE IN TIMING. LOW CONFIDENCE IN ANY CIGS BELOW
2000 FT.
* HIGH CONFIDENCE IN WIND DIRECTIONAL TRENDS. MEDIUM CONFIDENCE
IN GUSTS.
* LOW CONFIDENCE IN ANY RETURNING BROKEN CIGS TONIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...CHC FOR MVFR.
TUESDAY...SMALL CHC FOR MORNING VFR.
WEDNESDAY...VFR.
THURSDAY...CHC OF SHRA AND MVFR.
FRIDAY...WINDY. CHC OF SHRA AND MVFR
SATURDAY...VFR.
MTF
&&
.MARINE...
224 AM CDT
BEHIND A COOL FRONT WHICH PASSED LATE ON SATURDAY...NORTHEAST FLOW
WILL CONTINUE ACROSS THE LAKE TODAY. THIS WILL BE DIRECTED INTO THE
NEARSHORE AREAS OF ILLINOIS AND INDIANA...FAVORING HIGH WAVES INTO
THE AFTERNOON AND EVENING. HIGH PRESSURE WILL SLIDE SOUTHWARD OVER
THE LAKE TONIGHT INTO EARLY MONDAY EASING WINDS. A WEAK COOL FRONT
WILL PASS FROM WEST TO EAST OVER THE LAKE ON MONDAY NIGHT...OFFERING
A WIND SHIFT BUT NO REAL INCREASE IN SPEED. THAT IS IN PART BECAUSE
LOW PRESSURE WILL BE MOVING NORTHEASTWARD FROM THE LOWER OHIO VALLEY
TO HUDSON BAY TUESDAY INTO WEDNESDAY SLOWING THE AFOREMENTIONED
BOUNDARY. A POTENTIALLY ACTIVE END OF THE WEEK OVER THE WESTERN
GREAT LAKES MAY BE IN STORE AS SEVERAL FORECAST MODELS INDICATE A
STRONG LOW PRESSURE SOMEWHERE IN THE UPPER MIDWEST/GREAT LAKES
REGION...WITH STRONG THERMAL ADVECTION CONDUCIVE FOR GUSTY WINDS
AHEAD AND BEHIND OF THE LOW PRESSURE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ006-ILZ014 UNTIL 4 AM MONDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002 UNTIL 4 AM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
647 AM CDT SUN SEP 30 2012
.DISCUSSION...
338 AM CDT
MAIN FORECAST CHALLENGES THIS MORNING ARE WITH LAKE EFFECT CLOUD
POTENTIAL NOW THROUGH LATE MORNING TODAY...WITH MOSTLY SUNNY SKIES
THEN EXPECTED FOR THE ENTIRE AREA INTO THE AFTERNOON AS TEMPS RISE
TO THE UPPER 60S AND LOW 70S.
LATEST WATER VAPOR IMAGERY DEPICTING A FAIRLY STRONG PIECE OF MID
LEVEL ENERGY WRAPPING AROUND THE CLOSED UPPER LEVEL SYSTEM ACROSS
THE EASTERN GREAT LAKES REGION THIS MORNING. AS THIS
OCCURS...COLDER AIR WILL CONTINUE TO WORK ITS WAY SOUTHWEST OVER
THE LAKE THIS MORNING AND ACROSS THE CWA THROUGH THE AFTERNOON.
WHAT THIS WILL MEAN FOR TODAY IS SLIGHTLY COOLER HIGH TEMPERATURES
ACROSS THE CWA AS WELL AS THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER TO SPILL INTO AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS AND
NORTHWEST INDIANA. AS WAS EXPECTED...LATEST RAP ANALYSIS SHOWING
DELTA TS FINALLY INCREASING ACROSS THE ENTIRE LENGTH OF THE
LAKE...WITH THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING. ALTHOUGH LATEST SATELLITE IMAGERY SHOWING THIS CLOUD
COVER SOMEWHAT SLOW TO DEVELOP OVER THE NORTHERN PORTIONS OF THE
LAKE...SHOULD BEGIN TO SEE AN INCREASE IN THIS DEVELOPMENT OVER
THE NEXT TWO TO THREE HOURS. FAVORED LOW LEVEL FLOW SHOULD KEEP
MOST OF ANY CLOUD COVER OVER AREAS IN FAR NORTHEAST ILLINOIS...BUT
WITH SOME CLOUD COVER TO STILL POSSIBLY SPILL OVER INTO AREAS IN
FAR NORTHWEST INDIANA. ALTHOUGH THIS CLOUD COVER IS EXPECTED TO
DEVELOP AND MOVE ACROSS AREAS NEAR THE LAKE...IT SHOULDNT BE MORE
THAN PARTLY CLOUDY SKIES WITH SOME BRIEF PERIODS OF PARTLY
SUNNY/CLOUDY CONDITIONS THROUGH THE 15Z TIME FRAME. AFTER THIS
TIME FRAME...CLOUD COVER SHOULD BEGIN TO DIMINISH INTO THE
AFTERNOON AS HIGHER PRESSURE SHIFTS DOWN THE LAKE. AFTER THIS
POINT...SKIES SHOULD BE MOSTLY SUNNY INTO THE AFTERNOON WITH
ANOTHER PLEASANT DAY IN STORE. ALTHOUGH TEMPS TODAY WILL BE
SLIGHTLY COOLER THAN YESTERDAY...I DID RAISE TEMPS A COUPLE OF
DEGREES OVER GUIDANCE WITH TEMPERATURES RISING INTO THE LOW 70S
FOR MOST AREAS IN NORTHERN ILLINOIS...WITH TEMPS SLIGHTLY COOLER
IN THE UPPER 60S IF NOT AROUND 70 MARK FOR AREAS NEAR THE LAKE.
NONETHELESS...A PLEASANT DAY WILL BE IN STORE FOR THE AREA TODAY.
AFTER QUIET CONDITIONS ONCE AGAIN TONIGHT INTO THE EARLY PORTIONS
OF MONDAY...A SOMEWHAT MORE ACTIVE WEATHER APPEARS TO BE ON THE
HORIZON. AS MID AND HIGH LEVEL CLOUD INCREASES FROM THE SOUTH ON
MONDAY...TEMPS SHOULD STILL RISE INTO THE LOW 70S ON MONDAY.
ALTHOUGH AS WAS EXPECTED OVER THE LAST 24 HOURS...MODELS CONTINUE
TO TREND TOWARDS BRINGING CURRENT CLOSED UPPER LEVEL LOW OVER THE
SOUTHERN PLAINS NORTHEAST TOWARDS THE AREA BY LATE MONDAY. MODEL
CONSENSUS SEEMS TO BRING THIS UPPER LEVEL SYSTEM AND SURFACE
REFLECTION UP THROUGH THE TENNESSEE VALLEY LATE MONDAY INTO EARLY
TUESDAY MORNING...AS A SEPARATE MID LEVEL TROUGH APPROACHES FROM
THE NORTHERN PLAINS. ALTHOUGH WITH A LACK OF MOISTURE WITH THIS
NORTHERN STREAM MID LEVEL TROUGH...PRECIP SHOULD BE DIMINISHING AS
IT APPROACHES THE CWA. BEST CHANCES FOR SHOWERS WILL BE FOR AREAS
ACROSS THE SOUTHEAST CWA MONDAY NIGHT. THIS SYSTEM WILL SLOWLY
SPIN ACROSS THE REGION...WITH PRECIP POSSIBLY LINGERING ACROSS
THE SAME AREA TUESDAY INTO TUESDAY NIGHT. CURRENT FORECAST KEEPS
PRECIP CHANCES THROUGH LATE IN THE DAY TUESDAY...BUT ITS
CONCEIVABLE THAT THIS SYSTEM WILL TAKE A SLOWER EASTWARD MOVEMENT.
IF THIS WERE TO OCCUR...PRECIP COULD LINGER INTO THE MIDDLE PART
OF THE WEEK BEFORE EXITING. AFTER WEAK RIDGING AND A SLIGHT
INCREASE IN TEMPS ON WEDNESDAY...ANOTHER MID LEVEL SYSTEM AND
SURFACE REFLECTION/FRONTAL BOUNDARY WILL APPROACH THE CWA WITH
PRECIP CHANCES INCREASING ONCE AGAIN TOWARDS THE END OF THE WORK
WEEK. IT WOULD APPEAR THAT MAINLY SHOWERS SHOULD BE OBSERVED AS
THIS SYSTEM PUSHES THROUGH THE AREA ON THURSDAY...BUT WITH SOME
UNCERTAINTY AS TO THE OVERALL AMOUNT OF MOISTURE/INSTABILITY
PRESENT OUT AHEAD OF IT. IF THE ECMWF WERE TO VERIFY...THEN
PRIMARILY SHOWERS WOULD BE OBSERVED. IN CONTRAST...THE GFS SEEMS
TO BE MORE AGGRESSIVE WITH DEWPOINTS AND IF THIS WERE TO
OCCUR...THEN THUNDERSTORMS COULD BE PRESENT OUT AHEAD OF THIS
SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LAKE EFFECT MVFR CIGS PROBABLE DURING THE MID-MORNING INTO EARLY
AFTERNOON...SOME OF WHICH AT ONSET COULD BE BELOW 2000 FT.
* NORTHEAST WINDS INCREASING IN SPEED BY MID-MORNING.
* SMALL CHANCE FOR MVFR CIGS TONIGHT AND EARLY MONDAY MORNING.
//DISCUSSION...UPDATED 12Z...
THE TERMINALS LIE BETWEEEN A COLD FRONT TO THE SOUTH WHICH PASSED
LATE YESTERDAY AND HIGH PRESSURE ACROSS ONTARIO AND QUEBEC. THE
GRADIENT BETWEEN THESE FEATURES WILL CONTINUE TO FAVOR A NORTHEAST
SYNOPTIC WIND. INITIALLY...THROUGH 14Z...A SLIGHTLY MORE NNW WIND
WILL BE SEEN ACROSS NORTHEAST IL DUE TO A REMNANT LAND BREEZE FROM
THE NIGHT. THIS IS AIDING CONVERGENCE INTO NORTHEAST IL THAT
SHOULD HELP TO FOCUS DEVELOPING CLOUDS OVER THE LAKE INTO
NORTHEAST IL BY MID MORNING...AND LIKELY TOWARD GYY AS WELL. THESE
LAKE ENHANCED CLOUDS ARE PRESENTLY FAVORED TO BE AT OR ABOVE 2000
FT BY THE TIME THEY ARRIVE AT THE TERMINALS...BUT AT ONSET SOME
COULD BE BELOW 2000 FT. THAT SHOULD BE BRIEF IF THAT OCCURS.
CLOUDS SHOULD GRADUALLY BECOME MORE SCATTERED THROUGH THE
AFTERNOON AS THE COLD AIR ADVECTION COMPONENT OVER THE WATER
WEAKENS. THE HIGH PRESSURE WILL SETTLE SOUTHWARD OVER THE AREA
THIS EVENING...WITH RETURN FLOW DEVELOPING ON MONDAY.
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN BROKEN CLOUDS BETWEEN 2000 AND 3500 FT.
MEDIUM CONFIDENCE IN TIMING. LOW CONFIDENCE IN ANY CIGS BELOW
2000 FT.
* HIGH CONFIDENCE IN WIND DIRECTIONAL TRENDS. MEDIUM CONFIDENCE
IN GUSTS.
* LOW CONFIDENCE IN ANY RETURNING BROKEN CIGS TONIGHT.
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...CHC FOR MVFR.
TUESDAY...SMALL CHC FOR MORNING VFR.
WEDNESDAY...VFR.
THURSDAY...CHC OF SHRA AND MVFR.
FRIDAY...WINDY. CHC OF SHRA AND MVFR
SATURDAY...VFR.
MTF
&&
.MARINE...
224 AM CDT
BEHIND A COOL FRONT WHICH PASSED LATE ON SATURDAY...NORTHEAST FLOW
WILL CONTINUE ACROSS THE LAKE TODAY. THIS WILL BE DIRECTED INTO THE
NEARSHORE AREAS OF ILLINOIS AND INDIANA...FAVORING HIGH WAVES INTO
THE AFTERNOON AND EVENING. HIGH PRESSURE WILL SLIDE SOUTHWARD OVER
THE LAKE TONIGHT INTO EARLY MONDAY EASING WINDS. A WEAK COOL FRONT
WILL PASS FROM WEST TO EAST OVER THE LAKE ON MONDAY NIGHT...OFFERING
A WIND SHIFT BUT NO REAL INCREASE IN SPEED. THAT IS IN PART BECAUSE
LOW PRESSURE WILL BE MOVING NORTHEASTWARD FROM THE LOWER OHIO VALLEY
TO HUDSON BAY TUESDAY INTO WEDNESDAY SLOWING THE AFOREMENTIONED
BOUNDARY. A POTENTIALLY ACTIVE END OF THE WEEK OVER THE WESTERN
GREAT LAKES MAY BE IN STORE AS SEVERAL FORECAST MODELS INDICATE A
STRONG LOW PRESSURE SOMEWHERE IN THE UPPER MIDWEST/GREAT LAKES
REGION...WITH STRONG THERMAL ADVECTION CONDUCIVE FOR GUSTY WINDS
AHEAD AND BEHIND OF THE LOW PRESSURE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ006-ILZ014 UNTIL 4 AM MONDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002 UNTIL 4 AM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
738 AM EDT SUN SEP 30 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EDT SUN SEP 30 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER THE
ERN GREAT LAKES AND A RIDGE UPSTREAM FROM MN TO NEAR JAMES BAY.
SINCE THE LOW HAS EDGED SLIGHTLY TO THE WEST...COOLER AIR AND AN
INCREASE IN LOW LEVEL MOISTURE HAS ALSO PUSHED WESTWARD THROUGH
UPPER MI WITH SOME PATCHY LOW CLOUDS...ESPECIALLY IN LOCATIONS FAVORED
BY NE UPSLOPE FLOW. FARTHER UPSTREAM...A SHRTWV AND NOSE OF A
250-300 JET STREAK WAS MOVING THROUGH SRN ALBERTA. AT THE SFC...A
RIDGE EXTENDED FROM NRN QUEBEC TO THE SOUTHWEST INTO THE NRN GREAT
LAKES.
TODAY...EXPECT ANY LINGERING LOWER CLOUDS TO THIN OUT BY MID TO LATE
MORNING WITH INCREASING DAYTIME HEATING. OTHERWISE...HIGH PRES WILL
CONTINUE TO DOMINATE THE REGION WITH MOSTLY SUNNY SKIES AND LIGHT
ERLY WINDS. WITH LITTLE CHANGE IN THE POSITION OF THE 925-850 MB
THERMAL TROUGH...TEMPS SHOULD BE SIMILAR TO SATURDAY WITH MAX
READINGS IN THE MID TO UPPER 60S INLAND AND AROUND 60 NEAR LAKE
SUPERIOR.
TONIGHT...THE SRN CANADA SHRTWV WILL MOVE THROUGH THE NRN PLAINS AND
WILL HELP NUDGE THE BLOCKY DOWNSTREAM RIDGE/TROUGH TO THE EAST.
HOWEVER...MDLS/ENSEMBLE CONSENSUS SUGGESTS THAT ANY PCPN WITH THE
TROUGH SHOULD REMAIN WEST OF LAKE SUPERIOR. AN INCREASE IN SRLY
WINDS AND SOME MID AND HIGH CLOUDS SHOULD KEEP TEMPS FROM FALLING
OFF AS MUCH. LOOK FOR MIN READINGS FROM THE UPPER 30S TO AROUND 40
INLAND AND CLOSE TO 50 FOR THE GREAT LAKES AND WHERE DOWNSLOPE SSW
FLOW PREVAILS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 510 AM EDT SUN SEP 30 2012
AT 12Z MON THERE WILL BE AN UPPER RIDGE OVER THE CWA...WITH A
SHORTWAVE TROUGH FROM WRN HUDSON BAY TO WRN MN. AHEAD OF THE
SHORTWAVE...A SFC TROUGH WILL BE OVER WRN LAKE SUPERIOR. MODELS NOT
SHOWING MUCH MOISTURE WITH THE SYSTEM...OR MUCH QPF...BUT MOST DO
SHOW SOME LIGHT PRECIP ASSOCIATED WITH A NARROW BAND OF LOW LEVEL
MOISTURE OVER PORTIONS OF THE CWA AS THE SHORTWAVE PASSES MON INTO
MON NIGHT. WILL KEEP SLIGHT CHANCE POPS IN THE FORECAST FOR THIS TIME.
ATTENTION THEN TURNS TO A MUCH STRONGER SYSTEM THAT MODELS SHOW
ENTERING THE NRN PLAINS TUE NIGHT AND STRENGTHENING SOMEWHERE IN THE
REGION AROUND THE CWA THU. MODELS THEN SHOW REINFORCING UPPER ENERGY
AND COLD AIR MOVING IN FRI INTO THE WEEKEND. OVERALL...THE FORECAST
DURING THIS TIME IS VERY UNCERTAIN AND QUITE TRICKY. THERE IS
SUBSTANTIAL RUN TO RUN VARIABILITY WITH MOST MODELS AS WELL AS MODEL
DISAGREEMENT...SO FORECAST CONFIDENCE IS LOW. THE OVERALL IDEA SHOWN
BY MODELS IS THAT THE UPPER TROUGH WILL DEEPEN AND CLOSE OFF
SOMEWHERE IN THE REGION THU...AND THEN MOVE NE TO JAMES BAY OR
QUEBEC FRI. NW LOW LEVEL WINDS AND 850MB TEMPS AS LOW AS -8C BEHIND
THE SYSTEM WOULD BE FAVORABLE FOR LAKE EFFECT RAIN/SNOW FRI INTO
SAT. MODELS HAVE BEEN SHOWING A GENERAL NORTHERLY TREND WITH THE LOW
TRACK...MORE TOWARD THE ECMWF WHICH HAS SHOWN BETTER CONTINUITY. NOW
THE LATEST RUN OF THE GFS (00Z/30) SLOWED THE EVOLUTION OF THE
SYSTEM BY 12-18 HOURS FROM THE PREVIOUS RUN. WITH THE SYSTEM
CURRENTLY S OF THE ALEUTIAN ISLANDS AT AROUND LAT 45N LON 160W IT IS
NOT BEING SAMPLED BY TRADITIONAL UPPER AIR NETWORK...SO HOPEFULLY
CONFIDENCE WILL BE IMPROVED WHEN THE SYSTEM MOVES INTO THE
OBSERVATION NETWORK OF WRN CANADA AROUND 00Z TUE. IT IS IMPORTANT TO
POINT THAT THERE IS A VERY WIDE GAMUT OF POSSIBLE REALITIES
RESULTING FROM DIFFERENT PATHS THIS SYSTEM MAY TAKE. IF THE SYSTEM
GOES MORE S OF THE CWA...SE TO NE GALES AND A WETTER/SNOWIER
FORECAST MAY RESULT. IF THE SYSTEM GOES N OF THE CWA...W GALES AND A
DRIER FORECAST MAY RESULT...WITH THE POSSIBILITY OF THUNDERSTORMS
ALONG THE ATTENDANT COLD FRONT. IF THE SYSTEM GOES OVER THE CWA...A
COMBINATION OF THE PREVIOUS SCENARIOS MAY RESULT. OF COURSE...THERE
IS ALSO THE POSSIBILITY THAT THE SYSTEM ENDS UP BEING SIGNIFICANTLY
WEAKER (OR EVEN STRONGER) THAN WHAT THE MODELS CURRENTLY SHOW. AM
REALLY NOT CERTAIN WHAT WILL HAPPEN...BUT AM LEANING TOWARD THE NRN
TRACK OF THE MORE PERSISTENT ECMWF AND FORECAST PERSISTENCE WITH
THIS SYSTEM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 737 AM EDT SUN SEP 30 2012
ANY LEFTOVER SHALLOW FOG SHOULD DISSIPATE BY AROUND 13Z THIS
MORNING WITH THE ONSET OF DAYTIME HEATING. OTHERWISE...EXPECT MAINLY VFR
CONDITIONS THIS FCST PERIOD AT ALL 3 TAF SITES WITH DRY HI PRES OVER
ONTARIO DOMINATING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EDT SUN SEP 30 2012
HIGH PRESSURE AND A WEAK PRESSURE GRADIENT WILL PERSIST TODAY.
SRLY WINDS WILL INCREASE INTO THE 10 TO 20 KT RANGE TONIGHT AHEAD OF
A TROUGH MOVING TOWARD THE REGION. WINDS WILL VEER TO THE WEST
MONDAY AND THEN TO THE NORTH MONDAY NIGHT BUT SHOULD REMAIN AT OR
BELOW 20 KT. HIGH PRESSURE WILL AGAIN DOMINATE TUESDAY WITH
RELATIVELY LIGHT WINDS. A LOW PRESSURE SYSTEM LIFTING INTO NORTHWEST
ONTARIO WILL PUSH A COLD FRONT THROUGH LAKE SUPERIOR THURSDAY WITH
STRONG WRLY WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
611 AM CDT SUN SEP 30 2012
.AVIATION...12Z TAF FOR KGRI. VFR CONDITIONS WILL PREVAIL DURING
THE VALID TIME PERIOD. AS HIGH CLOUDS CONTINUE TO EXIT THE
REGION...MOSTLY CLEAR SKIES WILL BE REALIZED OVER THE TERMINAL
SITE TODAY. SHORTLY AFTER MIDNIGHT...NAM FORECAST SOUNDINGS
SUGGEST CLOUDS WILL BEGIN TO ROLL IN OVER THE TAF SITE IN
ASSOCIATION WITH AN APPROACHING COLD FRONT. SHOWERS ARE EXPECTED
TO FORM OVER WESTERN NEBRASKA THIS AFTERNOON...BUT THESE SHOWERS
ARE NOT EXPECTED TO IMPACT THE TERMINAL SITE.
&&
.PREV DISCUSSION... /ISSUED 406 AM CDT SUN SEP 30 2012/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. MAIN FORECAST CONCERN IS
ISOLATED THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON/EVENING...
FOLLOWED BY THE PASSAGE OF A COLD FRONT SHORTLY THEREAFTER.
WEAK SURFACE HIGH PRESSURE CENTERED NEAR HILL CITY KANSAS THIS
MORNING HAS KEPT WINDS LIGHT...WITH ONLY SOME HIGH CLOUDS SCRAPING
THE SOUTHEAST 1/3 OF THE FORECAST AREA. TEMPERATURES WARMER
IN THE CLOUDY AREAS...AS OPPOSED TO CLOUD FREE REGIONS.
ONE EARLY...ALTHOUGH MINOR CONCERN...MAY BE A BIT OF FOG IN THE FAR
SOUTHWEST/WESTERN FORECAST AREA. LATEST HRRR DATA IS SHYING AWAY
FROM ANY FOG OR LOW CLOUDS IN OUR FORECAST AREA...OPTING INSTEAD
JUST TO THE WEST WHERE SOUTHERLY FLOW HAS ALLOWED FOR A LITTLE
BETTER MOISTURE RETURN. MOST LIKELY THIS STUFF WOULDN/T GET GOING
UNTIL CLOSE TO SUNRISE...SO ITS A GAME TIME DECISION WHETHER ITS
WORTH EVEN BEING PART OF THE FORECAST. RIGHT NOW...ITS NOT LOOKING
TO LIKELY TO FORM.
THE MAIN STORY REST OF THE DAY IS WHETHER THE WESTERN PART OF THE
FORECAST CAN SHARE IN SOME ISOLATED SHOWERS/THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING. WEAK SURFACE CONVERGENCE ALONG A BOUNDARY
STARTS TO PUSHING THE FAR WESTERN SECTION OF THE FORECAST ABOUT MID
AFTERNOON. THIS COINCIDES WITH NARROW AXIS OF MOISTURE AND SURFACE
INSTABILITY BRIEFLY ABOVE 1000 J/KG. STEEP MID LEVEL LAPSE RATES ALSO
SET UP. THERE LIKELY WILL BE SOME HIGH BASED SHOWERS/ISOLATED
THUNDERSTORMS FORMING JUST TO THE WEST OF THE FORECAST AREA AROUND
3-4 PM...AND THEN GRADUALLY MIGRATE EAST. HAVE CONTINUED WITH THE
20-30% CHANCE OF RAIN...NOT SO MUCH FOR UNCERTAINTY ON CONVECTIVE
ACTIVITY...BUT KEPT THINGS ON THE LOW SIDE WITH LARGE LOW
LEVEL DEWPOINT DEPRESSIONS AND CLASSIC INVERTED V SOUNDINGS. BOTH
SUGGEST LIMITED RAINFALL...BUT SOME WIND GUST POTENTIAL TO NEAR
SEVERE LEVELS. HAVE INCLUDED SOME CHANCE INTO THE EARLY EVENING
AS FAR EAST AS HIGHWAY 281...ALTHOUGH THAT MAY WELL BE STRETCHING
IT WITH STORM MOTIONS PROBABLY AROUND 10KTS OR SO. LATEST MODELS
HAVE FAVORED A LITTLE FURTHER WEST PROFILE...SO KEPT THE BEST
SHOT FOR RAIN THERE.
WELL...ONCE THAT STUFF WRAPS BY LATE EVENING...ATTENTION TURNS
TO ONCOMING COLD FRONT LATE TONIGHT AND EARLY MONDAY. PRETTY STRONG
PRESSURE RISES AS THE FRONT PASSES...SO EXPECT THE WIND TO PICK UP
PRETTY STEADY BY LATE TONIGHT. GOOD MOMENTUM TRANSFER WILL CONTINUE
ALL DAY MONDAY WITH NEARLY UNIDIRECTIONAL FLOW GIVING US THE FIRST
BREEZY/WINDY DAY...SINCE THE LAST COLD FRONT A FEW DAYS AGO. MODELS
TRY TO SQUEEZE OUT SOME LIGHT SHOWERS...PROBABLY SPRINKLES. NONE THE
LESS...HAVE WORKED IN TANDEM WITH OTHER OFFICES TO INCLUDE A SLIGHT
CHANCE OF LIGHT SHOWERS MONDAY MORNING...BEFORE SUNSHINE TAKES OVER
LATER. TEMPERATURES WILL NOT ONLY FEEL COOLER DUE TO THE NORTH
WIND...BUT ACTUALLY BE COOLER DURING THE DAY MONDAY.
NOT MUCH ELSE TO WORRY ABOUT MONDAY NIGHT THROUGH TUESDAY NIGHT...
WITH A COOL NIGHT MONDAY NIGHT...GIVING WAY TO A REALLY NICE AND
MILD DAY TUESDAY WITH SUNSHINE AND LIGHT WINDS.
LONG TERM...12Z WEDNESDAY THROUGH SATURDAY. A COLD FRONT
PROGGED TO TRANSITION THROUGH THE REGION WEDNESDAY NIGHT INTO
THURSDAY WILL PROVE TO BE THE MOST CHALLENGING ASPECT OF THE
EXTENDED FORECAST. CHALLENGES WILL RESULT IN PRECIPITATION
TIMING/COVERAGE AND TEMPERATURES BOTH AHEAD AND BEHIND THE COLD
FRONT. PRECIP CHANCES WILL ALSO BE REALIZED TOWARDS THE END OF THE
LONG TERM.
A COLD FRONT WILL EXTEND DOWN INTO THE CENTRAL PLAINS ON THURSDAY
FROM FROM AN ASSOCIATED UPPER LEVEL TROUGH FORECAST TO PASS
THROUGH THE NORTHERN PLAINS. RETURN FLOW IN THE LOWER LEVELS AHEAD
OF THIS FRONTAL BOUNDARY SHOULD ADVECT ENOUGH MOISTURE INTO THE
CENTRAL PLAINS TO HELP AID IN THE DEVELOPMENT OF SOME STRATIFORM
RAIN ACROSS THE OUTLOOK AREA. FORECAST SOUNDINGS SUGGEST A MOIST
ATMOSPHERIC PROFILE BEGINNING AROUND MIDNIGHT ON WEDNESDAY AND
CONTINUING THROUGH THE MORNING HOURS OF THURSDAY. PRECIPITATION
TIMING WILL RELY SOLELY ON THE TIMING OF THE COLD FRONT...BUT
CURRENT ANALYSIS LEADS TO PRECIP BEGINNING LATE WEDNESDAY NIGHT AND
CONTINUING THROUGH THURSDAY MORNING BEHIND THE COLD FRONT. NO SEVERE
WEATHER IS ANTICIPATED.
THE BIGGEST CHANGE IN THE FORECAST WAS WEDNESDAY HIGH
TEMPERATURES...WHICH WILL BE NEAR 80 DEGREES AHEAD OF THE FRONT FOR
MOST OF THE OUTLOOK AREA. THIS CHANGE IS MAINLY DUE TO THE TIMING OF
THE FRONT BEING A LITTLE SLOWER THAN PREVIOUSLY FORECAST.
FURTHERMORE...850MB TEMPS ALSO SUGGEST HIGHER TEMPERATURES THAN THE
OUTPUT FROM ALLBLEND. THURSDAY HIGH TEMPERATURES AND FRIDAY MORNING
LOW TEMPERATURES HAVE BEEN RATHER TRICKY WITH THE PASSAGE OF THE
FRONTAL BOUNDARY OVER THE LAST COUPLE OF DAYS. SEEMS AS THOUGH THE
MODELS MAY HAVE FINALLY SETTLED ON A SOLUTION. THE PAST SEVERAL DAYS
HAVE SHOWN A GENERAL DECREASE IN TEMPERATURES ACROSS THE CWA FOR
THURSDAY HIGH TEMPERATURES AND THE OVERNIGHT LOWS...BUT TEMPERATURES
ARE NOW NEARLY CONSISTENT WITH THE PREVIOUS FORECAST. THURSDAY WILL
BE BELOW NORMAL FOR HIGHS AS UPPER 50S AND LOWER 60S ARE FORECAST.
IN FACT...THE REST OF THE LONG TERM IS FORECAST TO EXPERIENCE BELOW
NORMAL TEMPERATURES FOR THIS TIME OF YEAR. THURSDAY NIGHT LOW
TEMPERATURES ARE STILL FLIRTING WITH FROST POTENTIAL. WILL NEED TO
MONITOR THIS OVER THE NEXT COUPLE OF DAYS. A FROST ADVISORY
MIGHT HAVE SOME CREDIBILITY ACROSS NORTHERN PARTS OF THE CWA NEXT
WEEK.
THERE WILL BE A CHANCE FOR PRECIPITATION FRIDAY NIGHT AND INTO
SATURDAY AS ANOTHER CONVERGENCE ZONE SETS UP OVER THE CENTRAL PLAINS
WITH FORECAST SOUNDINGS SUGGESTING A MOIST ATMOSPHERIC PROFILE.
AGAIN...SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...NOAA/NWS/MORITZ
LONG TERM/AVIATION...GUERRERO
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
645 AM EDT SUN SEP 30 2012
.SYNOPSIS...
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE
THIS WEEK AS A COLD FRONT STALLS ACROSS THE EASTERN CAROLINAS.
WEATHER WILL REMAIN UNSETTLED THROUGH MID WEEK AS LOW PRESSURE
DEVELOPS ALONG THE GULF COAST AND MOVES NORTHEAST ACROSS THE
TENNESSEE VALLEY. A COLD FRONT WILL CROSS THE AREA BY LATE WEEK
BRINGING DRIER AND COOLER WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...THE LAST OF THE SHOWERS ARE DISSIPATING AS
THEY MOVE INTO WILMINGTON EARLY THIS MORNING. DRY WEATHER IS
EXPECTED THE REMAINDER OF THE DAY...ALTHOUGH THE 06Z MODELS CONTINUE
TO DIVERGE ON HOW MUCH CLEARING AND HEATING WE WILL END UP SEEING
THIS AFTERNOON. THE 06Z NAM AND ESPECIALLY 09Z RUC ARE QUITE A BIT
WARMER THAN THE 06Z GFS. INFRARED BRIGHTNESS TEMPERATURES ACROSS
NORTH CAROLINA AWAY FROM THE CIRRUS DECK CONTINUE TO READ 8 DEGREES
CELSIUS...INDICATIVE OF A CLOUD TOP 6500-7000 FT AGL. IF THIS IS
CORRECT WE WILL SEE A VERY SLOW BURNOFF OF CLOUDS TODAY...WITH
OVERCAST CONDITIONS PERHAPS LINGERING INTO THE AFTERNOON HOURS.
PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
THE SURFACE COLD FRONT HAS PUSHED INTO NORTHEASTERN SOUTH CAROLINA
ROUGHLY FROM MYRTLE BEACH TO NEAR KINGSTREE. WAVES OF SHOWERS AND
EMBEDDED THUNDERSTORMS NORTH OF THE BOUNDARY ARE FEEDING OFF 500-750
J/KG OF ELEVATED INSTABILITY WITH SYNOPTIC LIFT PROVIDED BY AN
UPPER-LEVEL DIVERGENT PATTERN IN THE RIGHT-ENTRANCE REGION OF A 300
MB JET STREAK OVER EASTERN NORTH CAROLINA. AS THIS JET STREAK MOVES
OFFSHORE IN THE NEXT FEW HOURS LOOK FOR SHOWERS AND STORMS TO MOVE
OFFSHORE AND/OR DISSIPATE.
LOW STRATUS CLOUDS NORTH OF THE FRONT WILL PERSIST THROUGH SUNRISE
AND POSSIBLY FOR SEVERAL HOURS BEYOND. IN FACT OUR BIGGEST FORECAST
CHALLENGE FOR THE DAYLIGHT HOURS IS DETERMINING HOW QUICKLY THESE
LOW CLOUDS DISSIPATE...WITH MAJOR IMPLICATIONS ON OUR HIGH
TEMPERATURES. GFS AND NAM FORECAST SOUNDINGS FOR 18Z TODAY DO NOT
NECESSARILY AGREE WITH SATELLITE DERIVED ESTIMATES OF THE STRATUS
CLOUD TOPS ACROSS NORTH CAROLINA CURRENTLY. GIVEN THE DEPTH OF
MOISTURE OBSERVED ON THE 00Z GSO AND RNK SOUNDINGS (WHICH DO AGREE
WITH THE SATELLITE ESTIMATES OF CLOUD TOPS) I HAVE LOWERED OUR HIGH
TEMPERATURE FORECASTS BY SEVERAL DEGREES TODAY...NOW RANGING FROM
THE MID TO UPPER 70S...BUT CONSIDERABLE UNCERTAINTY REMAINS.
SYNOPTIC LOW PRESSURE DEVELOPING ALONG THE TX GULF COAST WILL MOVE
EAST INTO MISSISSIPPI TONIGHT. INCREASING SOUTHERLY LOW LEVEL FLOW
ALONG THE SOUTH ATLANTIC COAST WILL PUSH THE FRONT NORTHWARD. ABOVE
THE FRONTAL SURFACE THE SOUTHERLY WINDS WILL ADVECT A WARM AND HUMID
AIRMASS OVERHEAD TONIGHT...PRODUCING AN ALMOST WINTER-LIKE
ISENTROPIC LIFT REGIME. THERE ARE NO FAVORABLY POSITIONED UPPER
LEVEL JETS TO ASSIST LIFT AND THEREFORE DESPITE FAIRLY HIGH POPS IN
OUR FORECAST (50-60 PERCENT TONIGHT) I HAVE KEPT QPF VALUES RATHER
LOW. LOWS SHOULD FALL INTO THE MID 60S FOR MOST AREAS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...STALLED FRONT WILL LIFT NORTH OF THE AREA EARLY
MON AS A WARM FRONT. THIS WILL RESULT IN PRECIP TRANSITIONING FROM
LIGHT RAIN TO DEEPER ISOLATED CONVECTION IN THE AFTERNOON. THE BIG
QUESTION FOR MONDAY WILL BE HOW MUCH LOW LEVEL INSTABILITY WILL BE
PRESENT. REGION SHOULD BE SOLIDLY IN THE WARM SECTOR BUT CLOUD COVER
WILL LIMIT DIURNAL HEATING. FLOW ALOFT MAY BE SLIGHTLY DIVERGENT BUT
LIKELY NOT ENOUGH TO SIGNIFICANTLY ENHANCE UPWARD MOTION. GIVEN THE
LACK OF ANY SIGNIFICANT TRIGGERS AND LIMITED DIURNAL INSTABILITY
WILL MAINTAIN HIGH CHANCE POP MON. MON NIGHT SURFACE LOW ASSOCIATED
WITH THE 5 TROUGH OVER THE MS VALLEY STARTS TO SLOWLY LIFT
NORTH...KEEPING THE SOUTHEAST IN THE WARM SECTOR. DEEP SOUTHERLY
FLOW AND ABUNDANT MOISTURE COMBINED WITH INCREASING DIVERGENCE ALOFT
WILL LEAD TO AN INCREASE IN CONVECTION LATE MON NIGHT...ESPECIALLY
OFFSHORE.
SURFACE LOW CONTINUE TO TRACK NORTH TUE INTO TUE NIGHT...MOVING
ACROSS THE TN/KY/OH VALLEYS AND ENDING UP OVER THE EASTERN GREAT
LAKES AT THE END OF THE PERIOD. THE COMBINATION OF SURFACE LOW
LIFTING NORTH-NORTHEAST AND THE GRADUAL EASTWARD MOVEMENT OF THE 5H
TROUGH HELPS PUSH A WEAK COLD FRONT ACROSS THE REGION TUE NIGHT.
AHEAD OF THE FRONT DEEP MOISTURE...PRECIPITABLE WATER VALUES CLIMB
OVER 2 INCHES TUE...ALONG WITH LOW LEVEL SPEED CONVERGENCE AND
WEAKLY DIVERGENT FLOW ALOFT HELPS GENERATE AFTERNOON SHOWERS AND
THUNDERSTORMS. FRONT ITSELF DOES NOT LOOK VERY ACTIVE AND ITS
ARRIVAL WILL NOT BE ACCOMPANIED BY SIGNIFICANT COLD
ADVECTION...THOUGH DEEP DRY AIR WILL START TO BUILD OVER THE
SOUTHEAST AS THE PERIOD ENDS.
ALTHOUGH CLOUD COVER AND PRECIP ARE EXPECTED BOTH DAYS THE WARM
SOUTHERLY FLOW WILL HELP KEEP HIGHS ABOVE CLIMO. LOWS WILL ALSO BE
ABOVE CLIMO...HELPED BY BOTH CLOUD COVER AND WINDS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...DEEP MOISTURE AND STALLED FRONT LINGERING ALONG
OR JUST OFF THE COAST WED WILL MAINTAIN THE CHANCE OF PRECIP EARLY
IN THE PERIOD. HIGHEST POP WED WILL BE ALONG THE COAST WITH MORE OF
A DIURNAL TREND...THOUGH NOCTURNAL CONVECTION OVER THE WATERS WED
NIGHT COULD MOVE ONSHORE AS IT DISSIPATES. MID LEVEL TROUGH MOVING
THROUGH THE NORTHEAST AND SOUTHEASTERN CANADA PUSHES A SURFACE LOW
OFF THE NEW ENGLAND COAST. AS THIS LOW MOVES EAST IT HELPS PULL THE
FRONT STALLED JUST OFF THE COAST FARTHER EAST. SOME DIFFERENCES
BETWEEN THE GFS/ECMWF SOLUTIONS WITH THE STALLED FRONT...THE GFS IS
ADVERTISING A SLOWER SOLUTION WHICH HOLDS ONTO POP ALONG THE COAST
THU AND THU NIGHT. INHERITED A SLIGHT CHANCE THU...WILL TRIM POP
INLAND BUT HOLD ONTO SLIGHT CHANCE AT THE COAST. LACK OF ANY REAL
COLD ADVECTION OR CLOUD COVER RESULTS IN HIGHS SEVERAL DEGREES ABOVE
CLIMO. LOW ALSO END UP ABOVE CLIMO...THOUGH ONLY BY A FEW DEGREES AS
DRIER AIR...ESPECIALLY INLAND...AND LIGHT WINDS ALLOW FOR SOME
RADIATIONAL COOLING.
SURFACE HIGH PRESSURE AND MUCH DRIER AIR BUILDS OVER THE REGION FRI
AND SAT. COMBINATION OF DEEP WEST TO NORTHWEST FLOW AND LOW LEVEL
NORTHEAST FLOW WILL KEEP THE REGION DRY WITH DOWNSLOPE FLOW HELPING
KEEP HIGHS SLIGHTLY ABOVE CLIMO. DRY AIR AND RADIATIONAL COOLING
WILL RESULT IN LOWS VERY CLOSE TO CLIMO TO END THE PERIOD.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...WIDESPREAD IFR CEILINGS WILL BE THE RULE FOR THE FIRST
FEW HOURS THIS MORNING...WITH SOME ISOLATED LOW VISIBILITIES. THE
MYRTLES ARE ON THE FRINGE OF THE IFR AND MAY COME UP FIRST. MOST OF
THE DEEP MOISTURE HAS RETREATED TO THE SOUTH AND EAST...WITH LITTLE
CHANCE FOR CONVECTION TODAY AS THE FRONT STALLS JUST TO THE SOUTH OF
THE REGION. TIME HEIGHT SHOWS A VERY THIN LAYER OF STRATA CU BY
EARLY AFTERNOON...IT WILL PROBABLY SCATTER. TONIGHT...WARM FRONT
WAVES BACK NORTH WITH PRECIPITATION RETURNING AFTER 03Z. CEILINGS
WILL ALSO DRIVE BACK DOWN TO IFR WITH ABUNDANT LOW LEVEL MOISTURE.
EXTENDED OUTLOOK...UNSETTLED WEATHER ASSOCIATED WITH A STALLED FRONT
COULD PRODUCE PERIODS OF IFR CONDITIONS ACROSS THE AREA THROUGH
THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...THE FRONT CONTINUES TO PRESS SOUTHWARD ALONG
THE SC COAST AND SHOULD BE MOVING INTO GEORGETOWN SHORTLY. NO
SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST. PREVIOUS DISCUSSION
FROM 330 AM FOLLOWS...
A COLD FRONT HAS PUSHED SOUTH THROUGH MYRTLE BEACH AND SHOULD STALL
OUT LATER TODAY JUST SOUTH OF GEORGETOWN. THERE IS NOT A STRONG
SURGE OF NORTH WINDS BEHIND THIS FRONT...AND WIND SPEEDS 10 KT OR
LESS ARE EXPECTED TO PREDOMINATE. WAVES OF SHOWERS AND THUNDERSTORMS
NORTH OF THE SURFACE FRONT ARE BEING PRODUCED BY AN UPPER LEVEL
DISTURBANCE MOVING OFF THE NC COAST AND SHOULD DIMINISH AROUND
DAYBREAK...AFFECTING MAINLY THE CAPE FEAR AREA.
FOR TONIGHT THE FRONT WILL BEGIN TO LIFT BACK TO THE NORTH IN
RESPONSE TO DEVELOPING LOW PRESSURE ALONG THE CENTRAL GULF COAST.
THE FRONT MAY REACH MYRTLE BEACH BY DAYBREAK MONDAY...WITH WINDS
SOUTH OF THE FRONT SHIFTING TO THE SOUTH...WITH LIGHTER NORTHEAST TO
EAST WINDS EXPECTED NORTH OF THE BOUNDARY. SEAS AT THE NEARSHORE AND
OFFSHORE BUOYS ARE ONLY 2 FEET CURRENTLY...AND LITTLE CHANGE IS
EXPECTED THROUGH TONIGHT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...WARM FRONT WILL LIFT NORTH OF THE WATERS MON
WITH SOUTHERLY FLOW DEVELOPING. RIGHT BEHIND THE FRONT WINDS WILL BE
EAST-SOUTHEAST...BUT DURING THE AFTERNOON WINDS BECOME MORE
SOUTHERLY. SLIGHT INCREASE IN GRADIENT WILL SEE WINDS INCREASE INTO
THE 10 TO 15 KT RANGE ON MON. FURTHER TIGHTENING OF THE GRADIENT IS
POSSIBLE MON NIGHT INTO TUE WHICH MAY RESULT IN A SOLID 15 KT TUE
INTO TUE NIGHT. LATE IN THE PERIOD WEAK COLD FRONT MOVES OFF THE
COAST. BEHIND THE FRONT WINDS BECOME WEST-SOUTHWEST AROUND 10 KT AS
GRADIENT RELAXES AND COLD ADVECTION FAILS TO DEVELOP. SEAS START OUT
2 TO 3 FT BUT BUILD TO 3 TO 4 FT LATE MON NIGHT AND 3 TO 5 FT TUE
INTO TUE NIGHT BEFORE SOUTHWEST FLOW AND REDUCTION IN SPEEDS RESULTS
IN A SLIGHT DECREASE IN SEAS.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...FRONT STALLED ACROSS THE WATERS AND LACK OF ANY
SIGNIFICANT GRADIENT WILL KEEP SPEEDS AROUND 10 KT OR LESS
WED...WITH A SOUTHWESTERLY COMPONENT. WED NIGHT HIGH PRESSURE
CENTERED TO THE WEST SLIDES NORTHEAST AS THE STALLED FRONT STARTS TO
PUSH EAST. WINDS VEER TO NORTHWEST LATE WED NIGHT AND CONTINUE
VEERING TO NORTHEAST THU AS HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST. LIGHT AND CHANGEABLE WINDS DURING THE PERIOD WILL RESULT
IN SEAS FALLING THROUGH THE PERIOD. 2 TO 4 FT WED DECREASING TO 2 TO
3 FT THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
634 AM EDT SUN SEP 30 2012
.SYNOPSIS...
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE
THIS WEEK AS A COLD FRONT STALLS ACROSS THE EASTERN CAROLINAS.
WEATHER WILL REMAIN UNSETTLED THROUGH MID WEEK AS LOW PRESSURE
DEVELOPS ALONG THE GULF COAST AND MOVES NORTHEAST ACROSS THE
TENNESSEE VALLEY. A COLD FRONT WILL CROSS THE AREA BY LATE WEEK
BRINGING DRIER AND COOLER WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...THE LAST OF THE SHOWERS ARE DISSIPATING AS
THEY MOVE INTO WILMINGTON EARLY THIS MORNING. DRY WEATHER IS
EXPECTED THE REMAINDER OF THE DAY...ALTHOUGH THE 06Z MODELS CONTINUE
TO DIVERGE ON HOW MUCH CLEARING AND HEATING WE WILL END UP SEEING
THIS AFTERNOON. THE 06Z NAM AND ESPECIALLY 09Z RUC ARE QUITE A BIT
WARMER THAN THE 06Z GFS. INFRARED BRIGHTNESS TEMPERATURES ACROSS
NORTH CAROLINA AWAY FROM THE CIRRUS DECK CONTINUE TO READ 8 DEGREES
CELSIUS...INDICATIVE OF A CLOUD TOP 6500-7000 FT AGL. IF THIS IS
CORRECT WE WILL SEE A VERY SLOW BURNOFF OF CLOUDS TODAY...WITH
OVERCAST CONDITIONS PERHAPS LINGERING INTO THE AFTERNOON HOURS.
PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
THE SURFACE COLD FRONT HAS PUSHED INTO NORTHEASTERN SOUTH CAROLINA
ROUGHLY FROM MYRTLE BEACH TO NEAR KINGSTREE. WAVES OF SHOWERS AND
EMBEDDED THUNDERSTORMS NORTH OF THE BOUNDARY ARE FEEDING OFF 500-750
J/KG OF ELEVATED INSTABILITY WITH SYNOPTIC LIFT PROVIDED BY AN
UPPER-LEVEL DIVERGENT PATTERN IN THE RIGHT-ENTRANCE REGION OF A 300
MB JET STREAK OVER EASTERN NORTH CAROLINA. AS THIS JET STREAK MOVES
OFFSHORE IN THE NEXT FEW HOURS LOOK FOR SHOWERS AND STORMS TO MOVE
OFFSHORE AND/OR DISSIPATE.
LOW STRATUS CLOUDS NORTH OF THE FRONT WILL PERSIST THROUGH SUNRISE
AND POSSIBLY FOR SEVERAL HOURS BEYOND. IN FACT OUR BIGGEST FORECAST
CHALLENGE FOR THE DAYLIGHT HOURS IS DETERMINING HOW QUICKLY THESE
LOW CLOUDS DISSIPATE...WITH MAJOR IMPLICATIONS ON OUR HIGH
TEMPERATURES. GFS AND NAM FORECAST SOUNDINGS FOR 18Z TODAY DO NOT
NECESSARILY AGREE WITH SATELLITE DERIVED ESTIMATES OF THE STRATUS
CLOUD TOPS ACROSS NORTH CAROLINA CURRENTLY. GIVEN THE DEPTH OF
MOISTURE OBSERVED ON THE 00Z GSO AND RNK SOUNDINGS (WHICH DO AGREE
WITH THE SATELLITE ESTIMATES OF CLOUD TOPS) I HAVE LOWERED OUR HIGH
TEMPERATURE FORECASTS BY SEVERAL DEGREES TODAY...NOW RANGING FROM
THE MID TO UPPER 70S...BUT CONSIDERABLE UNCERTAINTY REMAINS.
SYNOPTIC LOW PRESSURE DEVELOPING ALONG THE TX GULF COAST WILL MOVE
EAST INTO MISSISSIPPI TONIGHT. INCREASING SOUTHERLY LOW LEVEL FLOW
ALONG THE SOUTH ATLANTIC COAST WILL PUSH THE FRONT NORTHWARD. ABOVE
THE FRONTAL SURFACE THE SOUTHERLY WINDS WILL ADVECT A WARM AND HUMID
AIRMASS OVERHEAD TONIGHT...PRODUCING AN ALMOST WINTER-LIKE
ISENTROPIC LIFT REGIME. THERE ARE NO FAVORABLY POSITIONED UPPER
LEVEL JETS TO ASSIST LIFT AND THEREFORE DESPITE FAIRLY HIGH POPS IN
OUR FORECAST (50-60 PERCENT TONIGHT) I HAVE KEPT QPF VALUES RATHER
LOW. LOWS SHOULD FALL INTO THE MID 60S FOR MOST AREAS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...STALLED FRONT WILL LIFT NORTH OF THE AREA EARLY
MON AS A WARM FRONT. THIS WILL RESULT IN PRECIP TRANSITIONING FROM
LIGHT RAIN TO DEEPER ISOLATED CONVECTION IN THE AFTERNOON. THE BIG
QUESTION FOR MONDAY WILL BE HOW MUCH LOW LEVEL INSTABILITY WILL BE
PRESENT. REGION SHOULD BE SOLIDLY IN THE WARM SECTOR BUT CLOUD COVER
WILL LIMIT DIURNAL HEATING. FLOW ALOFT MAY BE SLIGHTLY DIVERGENT BUT
LIKELY NOT ENOUGH TO SIGNIFICANTLY ENHANCE UPWARD MOTION. GIVEN THE
LACK OF ANY SIGNIFICANT TRIGGERS AND LIMITED DIURNAL INSTABILITY
WILL MAINTAIN HIGH CHANCE POP MON. MON NIGHT SURFACE LOW ASSOCIATED
WITH THE 5 TROUGH OVER THE MS VALLEY STARTS TO SLOWLY LIFT
NORTH...KEEPING THE SOUTHEAST IN THE WARM SECTOR. DEEP SOUTHERLY
FLOW AND ABUNDANT MOISTURE COMBINED WITH INCREASING DIVERGENCE ALOFT
WILL LEAD TO AN INCREASE IN CONVECTION LATE MON NIGHT...ESPECIALLY
OFFSHORE.
SURFACE LOW CONTINUE TO TRACK NORTH TUE INTO TUE NIGHT...MOVING
ACROSS THE TN/KY/OH VALLEYS AND ENDING UP OVER THE EASTERN GREAT
LAKES AT THE END OF THE PERIOD. THE COMBINATION OF SURFACE LOW
LIFTING NORTH-NORTHEAST AND THE GRADUAL EASTWARD MOVEMENT OF THE 5H
TROUGH HELPS PUSH A WEAK COLD FRONT ACROSS THE REGION TUE NIGHT.
AHEAD OF THE FRONT DEEP MOISTURE...PRECIPITABLE WATER VALUES CLIMB
OVER 2 INCHES TUE...ALONG WITH LOW LEVEL SPEED CONVERGENCE AND
WEAKLY DIVERGENT FLOW ALOFT HELPS GENERATE AFTERNOON SHOWERS AND
THUNDERSTORMS. FRONT ITSELF DOES NOT LOOK VERY ACTIVE AND ITS
ARRIVAL WILL NOT BE ACCOMPANIED BY SIGNIFICANT COLD
ADVECTION...THOUGH DEEP DRY AIR WILL START TO BUILD OVER THE
SOUTHEAST AS THE PERIOD ENDS.
ALTHOUGH CLOUD COVER AND PRECIP ARE EXPECTED BOTH DAYS THE WARM
SOUTHERLY FLOW WILL HELP KEEP HIGHS ABOVE CLIMO. LOWS WILL ALSO BE
ABOVE CLIMO...HELPED BY BOTH CLOUD COVER AND WINDS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...DEEP MOISTURE AND STALLED FRONT LINGERING ALONG
OR JUST OFF THE COAST WED WILL MAINTAIN THE CHANCE OF PRECIP EARLY
IN THE PERIOD. HIGHEST POP WED WILL BE ALONG THE COAST WITH MORE OF
A DIURNAL TREND...THOUGH NOCTURNAL CONVECTION OVER THE WATERS WED
NIGHT COULD MOVE ONSHORE AS IT DISSIPATES. MID LEVEL TROUGH MOVING
THROUGH THE NORTHEAST AND SOUTHEASTERN CANADA PUSHES A SURFACE LOW
OFF THE NEW ENGLAND COAST. AS THIS LOW MOVES EAST IT HELPS PULL THE
FRONT STALLED JUST OFF THE COAST FARTHER EAST. SOME DIFFERENCES
BETWEEN THE GFS/ECMWF SOLUTIONS WITH THE STALLED FRONT...THE GFS IS
ADVERTISING A SLOWER SOLUTION WHICH HOLDS ONTO POP ALONG THE COAST
THU AND THU NIGHT. INHERITED A SLIGHT CHANCE THU...WILL TRIM POP
INLAND BUT HOLD ONTO SLIGHT CHANCE AT THE COAST. LACK OF ANY REAL
COLD ADVECTION OR CLOUD COVER RESULTS IN HIGHS SEVERAL DEGREES ABOVE
CLIMO. LOW ALSO END UP ABOVE CLIMO...THOUGH ONLY BY A FEW DEGREES AS
DRIER AIR...ESPECIALLY INLAND...AND LIGHT WINDS ALLOW FOR SOME
RADIATIONAL COOLING.
SURFACE HIGH PRESSURE AND MUCH DRIER AIR BUILDS OVER THE REGION FRI
AND SAT. COMBINATION OF DEEP WEST TO NORTHWEST FLOW AND LOW LEVEL
NORTHEAST FLOW WILL KEEP THE REGION DRY WITH DOWNSLOPE FLOW HELPING
KEEP HIGHS SLIGHTLY ABOVE CLIMO. DRY AIR AND RADIATIONAL COOLING
WILL RESULT IN LOWS VERY CLOSE TO CLIMO TO END THE PERIOD.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...SURFACE COLD FRONT IS SINKING SOUTH ACROSS THE EASTERN
CAROLINAS...RUNNING AT 06Z FROM ABOUT 20 MILES S OF ILM...TO 15
MILES NW OF MYR...TO 15 MILES S OF FLO. THE BOUNDARY SHOULD CONTINUE
TO SINK SOUTH THROUGH DAYBREAK. SHOWERS AND THUNDERSTORMS JUST NORTH
OF THE FRONT ARE ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE THAT
WILL PUSH OFF THE NC COAST BY 09Z...TAKING PRECIP CHANCES WITH IT.
THE FOCUS WILL TURN FROM CONVECTION TO LOW CEILINGS: LOW STRATUS IN
THE 300-800 FT AGL RANGE WILL SLIP SOUTH BEHIND THE FRONT AND
THREATEN ALL OF OUR AIRPORTS THIS MORNING.
STRATUS AND ANY REDUCED VSBY IN BR WILL MIX OUT IN THE 13-14Z TIME
FRAME...WITH VFR AND SCT/BKN MID AND HIGH CLOUDS THIS AFTERNOON. THE
FRONT WILL BEGIN TO SWING BACK TO THE NORTH TONIGHT WITH A
WINTER-LIKE RAIN SHIELD EXPECTED AS OVERRUNNING MOISTURE-LADEN SOUTH
WINDS DEVELOP.
EXTENDED OUTLOOK...UNSETTLED WEATHER ASSOCIATED WITH A STALLED FRONT
COULD PRODUCE PERIODS OF IFR CONDITIONS ACROSS THE AREA THROUGH
THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SUNDAY...THE FRONT CONTINUES TO PRESS SOUTHWARD ALONG
THE SC COAST AND SHOULD BE MOVING INTO GEORGETOWN SHORTLY. NO
SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST. PREVIOUS DISCUSSION
FROM 330 AM FOLLOWS...
A COLD FRONT HAS PUSHED SOUTH THROUGH MYRTLE BEACH AND SHOULD STALL
OUT LATER TODAY JUST SOUTH OF GEORGETOWN. THERE IS NOT A STRONG
SURGE OF NORTH WINDS BEHIND THIS FRONT...AND WIND SPEEDS 10 KT OR
LESS ARE EXPECTED TO PREDOMINATE. WAVES OF SHOWERS AND THUNDERSTORMS
NORTH OF THE SURFACE FRONT ARE BEING PRODUCED BY AN UPPER LEVEL
DISTURBANCE MOVING OFF THE NC COAST AND SHOULD DIMINISH AROUND
DAYBREAK...AFFECTING MAINLY THE CAPE FEAR AREA.
FOR TONIGHT THE FRONT WILL BEGIN TO LIFT BACK TO THE NORTH IN
RESPONSE TO DEVELOPING LOW PRESSURE ALONG THE CENTRAL GULF COAST.
THE FRONT MAY REACH MYRTLE BEACH BY DAYBREAK MONDAY...WITH WINDS
SOUTH OF THE FRONT SHIFTING TO THE SOUTH...WITH LIGHTER NORTHEAST TO
EAST WINDS EXPECTED NORTH OF THE BOUNDARY. SEAS AT THE NEARSHORE AND
OFFSHORE BUOYS ARE ONLY 2 FEET CURRENTLY...AND LITTLE CHANGE IS
EXPECTED THROUGH TONIGHT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...WARM FRONT WILL LIFT NORTH OF THE WATERS MON
WITH SOUTHERLY FLOW DEVELOPING. RIGHT BEHIND THE FRONT WINDS WILL BE
EAST-SOUTHEAST...BUT DURING THE AFTERNOON WINDS BECOME MORE
SOUTHERLY. SLIGHT INCREASE IN GRADIENT WILL SEE WINDS INCREASE INTO
THE 10 TO 15 KT RANGE ON MON. FURTHER TIGHTENING OF THE GRADIENT IS
POSSIBLE MON NIGHT INTO TUE WHICH MAY RESULT IN A SOLID 15 KT TUE
INTO TUE NIGHT. LATE IN THE PERIOD WEAK COLD FRONT MOVES OFF THE
COAST. BEHIND THE FRONT WINDS BECOME WEST-SOUTHWEST AROUND 10 KT AS
GRADIENT RELAXES AND COLD ADVECTION FAILS TO DEVELOP. SEAS START OUT
2 TO 3 FT BUT BUILD TO 3 TO 4 FT LATE MON NIGHT AND 3 TO 5 FT TUE
INTO TUE NIGHT BEFORE SOUTHWEST FLOW AND REDUCTION IN SPEEDS RESULTS
IN A SLIGHT DECREASE IN SEAS.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...FRONT STALLED ACROSS THE WATERS AND LACK OF ANY
SIGNIFICANT GRADIENT WILL KEEP SPEEDS AROUND 10 KT OR LESS
WED...WITH A SOUTHWESTERLY COMPONENT. WED NIGHT HIGH PRESSURE
CENTERED TO THE WEST SLIDES NORTHEAST AS THE STALLED FRONT STARTS TO
PUSH EAST. WINDS VEER TO NORTHWEST LATE WED NIGHT AND CONTINUE
VEERING TO NORTHEAST THU AS HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST. LIGHT AND CHANGEABLE WINDS DURING THE PERIOD WILL RESULT
IN SEAS FALLING THROUGH THE PERIOD. 2 TO 4 FT WED DECREASING TO 2 TO
3 FT THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...TRA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
709 AM EDT SUN SEP 30 2012
.SYNOPSIS...
LOW PRESSURE OVER THE EAST COAST WILL MOVE SLOWLY NORTHEAST AND
EXTEND A TROUGH BACK WEST OVER THE REGION THROUGH TONIGHT. HIGH
PRESSURE WILL BUILD EAST ON MONDAY ACROSS THE AREA. LOW PRESSURE
AND A RESULTING WARM FRONT WILL LIFT NORTH ACROSS THE REGION ON
TUESDAY. THE LOW WILL REMAIN IN THE AREA THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED TO MAKE MINOR CHANGES TO THE SKY COVER AND POPS FOR THE
MORNING. STILL SOME QUESTION HOW EXTENSIVE THE COVERAGE OF SHOWERS
TODAY. THE CIRCULATION AROUND THE LOW WILL BE VERY CYCLONIC SO
THAT SHOULD ENHANCE THE CLOUDS AND SHOWERS AND THUNDERSTORMS.
THE UPPER LOW OVER THE EASTERN GREAT LAKES EARLY THIS MORNING
WILL MOVE SOUTHEAST TODAY. THE BIG QUESTION IS WHAT KIND OF POP IS
NEEDED FOR NE OH AND NW PA AND HOW FAR WEST TO CARRY A THREAT. THE
HRRR MODEL REALLY DECREASES THE THREAT BY DAYBREAK. WITH THE
INSTABILITY SO STRONG THE LAKE AND 500 MB TEMPERATURE DIFFERENCE
NEAR 43C FROM LAKE COUNTY EAST TODAY...WILL KEEP THE LIKELY POPS
GOING THROUGH EARLY TO MID AFTERNOON AND THEN DECREASE THEM AS
SUBSIDENCE OCCURS BEHIND THE VORT MAX. THE HRRR IS NOW KEEPING
SHOWERS GOING LONGER INTO THE AFTERNOON WHICH SEEMS GOOD WITH SOME
MUCH INSTABILITY. MOST MODELS AGREE WITH THIS. CONFIDENCE IS
MODERATE. AS PER THE HRRR MODEL AND SOME SHOWERS ON LAKE HURON
WILL HAVE A THREAT OF SHOWERS AS FAR WEST AS THE ISLANDS. USED A
BLEND OF GUIDANCE FOR THE HIGHS...COOLER EAST BECAUSE OF THE
CLOUDS AND SHOWERS AND WARMER WEST WITH SOME SUNSHINE THIS
AFTERNOON.
WILL MENTION OF THREAT OF SMALL HAIL IN EXTREME NE OH AND NW PA
AND WATERSPOUTS OVER THE EAST END OF THE LAKE. THIS WILL BE IN
GRIDS AND THE HWO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE WILL BE BUILDING IN BUT WITH THE LAKE AND 850 MB
TEMPERATURE DIFFERENCE NEAR 13C SOME LAKE ENHANCED SHOWERS MAY
OCCUR. THE BEST CHANCE WOULD BE NW PA WHERE THE MOISTURE IS A LITTLE
BETTER...ESPECIALLY EARLY TONIGHT. ELSEWHERE SOME CIRRUS WILL BE
MOVING IN FROM THE SOUTHWEST. THIS MAY HELP LIMIT ANY WIDESPREAD
DENSE FOG FROM DEVELOPING...SO WILL NOT MENTION IT AT THIS TIME.
WATCHING THE NEXT WEATHER MAKER FOR THE REGION FROM THE GULF OF
MEXICO. THE 00Z ECMWF IS VERY QUICK WITH THIS SYSTEM...DIDN`T GO AS
FAST AS THE ECMWF BUT DID SPEED THE TIMING OF THE SHOWERS A LITTLE
BIT. LIKELY LOOKS GOOD MONDAY NIGHT INTO TUESDAY AND THEN CHANCE
AFTER THAT AS WE GET CLOSE TO THE WARM SECTOR. AT THIS TIME NO
MENTION OF THUNDER BUT A THREAT WILL EVENTUALLY HAVE TO BE
MENTIONED. NOT CONFIDENT ENOUGH TO FORECAST IT AT THIS TIME.
USED A BLEND OF THE GUIDANCE BUT WITH PLENTY OF CLOUDS AND SHOWERS
AROUND WENT COOLER FOR THE HIGHS AND WARMER FOR THE LOWS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE PERIOD WILL START OUT DRY ON THURSDAY AS THE AREA WILL BE
BETWEEN WEATHER SYSTEMS. MODELS CONTINUE TO MOVE NEXT COLD FRONT
ACROSS THE AREA ON FRIDAY. ECMWF CONTINUES TO BE THE FASTER OF THE
2 MODELS. ECMWF HAS THE FRONT JUST EXITING THE AREA BY 12Z FRIDAY
WHILE THE GFS JUST HAS THE FRONT INTO NW OH. CONTINUED TO USE THE
SLOWER GFS FOR FORECAST. MODELS DIFFER SIGNIFICANTLY ON SATURDAY.
ECMWF HAS ANOTHER STRONG COLD FRONT PUSHING ACROSS THE AREA ON
SATURDAY. GFS ON OTHER HAND HAS LARGE LOW SETTING UP OVER JAMES BAY
WITH A SERIES OF TROUGHS SWINGING ACROSS EASTERN LAKES. FOR NOW
WILL CONTINUE WITH THE GFS SOLUTION. LEFT CHANCE POPS SNOWBELT EAST
OF CLEVELAND FOR SATURDAY WITH TROUGH AND IN ADDITION 850 MB TEMPS
DIP TO MINUS 4C SETTING UP POTENTIAL FOR LAKE EFFECT SHOWERS.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
UPPER LEVEL SHORT WAVE NOW OVER SOUTHERN LAKE HURON WILL SWING
ACROSS THE AREA THIS MORNING. THIS WILL PRODUCE SCATTERED SHOWERS
AND ISOLATED TSRA FROM CLE EAST THIS MORNING. DO NOT THINK IT
WILL BE ANY WORSE THAN MVFR CONDITIONS IN THE HEAVIER SHOWERS.
SKIES WILL BEGIN TO SCATTER OUT FROM THE NORTH BY MID AFTERNOON
AS THE VORT MAX SWINGS SOUTH OF THE AREA.
.OUTLOOK...NON-VFR CONDITIONS PROBABLE TUESDAY INTO WEDNESDAY IN
SHRA.
&&
.MARINE...
FLOW WILL BECOME NORTHEAST TODAY BUT CONDITIONS WILL STAY BELOW
SMALL CRAFT ADVISORY CRITERIA. NE FLOW WILL CONTINUE ON SUNDAY AND
THEN BECOME NORTHERLY ON SUNDAY NIGHT AS HIGH PRESSURE BRIEFLY
RETURNS. LOCAL SCHEMES SHOWING A GOOD CHANCE FOR WATERSPOUTS ON
SUNDAY. BEST CHANCES FOR THIS WILL BE TO THE EAST OF CLEVELAND AND
ANYWHERE A DECENT SHOWER DEVELOPS. LOW PRESSURE STILL FORECAST TO
MOVE ACROSS THE OHIO VALLEY ON TUESDAY...AND ACROSS LAKE ERIE
TUESDAY NIGHT. MODELS STILL NOT IN GOOD AGREEMENT ON EXACT TRACK
AND TIMING.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
659 AM EDT SUN SEP 30 2012
.SYNOPSIS...
LOW PRESSURE OVER THE EAST COAST WILL MOVE SLOWLY NORTHEAST AND
EXTEND A TROUGH BACK WEST OVER THE REGION THROUGH TONIGHT. HIGH
PRESSURE WILL BUILD EAST ON MONDAY ACROSS THE AREA. LOW PRESSURE
AND A RESULTING WARM FRONT WILL LIFT NORTH ACROSS THE REGION ON
TUESDAY. THE LOW WILL REMAIN IN THE AREA THROUGH WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED TO MAKE MINOR CHANGES TO THE SKY COVER AND POPS FOR THE
MORNING. STILL SOME QUESTION HOW EXTENSIVE THE COVERAGE OF SHOWERS
TODAY. THE CIRCULATION AROUND THE LOW WILL BE VERY CYCLONIC SO
THAT SHOULD ENHANCE THE CLOUDS AND SHOWERS AND THUNDERSTORMS.
THE UPPER LOW OVER THE EASTERN GREAT LAKES EARLY THIS MORNING
WILL MOVE SOUTHEAST TODAY. THE BIG QUESTION IS WHAT KIND OF POP IS
NEEDED FOR NE OH AND NW PA AND HOW FAR WEST TO CARRY A THREAT. THE
HRRR MODEL REALLY DECREASES THE THREAT BY DAYBREAK. WITH THE
INSTABILITY SO STRONG THE LAKE AND 500 MB TEMPERATURE DIFFERENCE
NEAR 43C FROM LAKE COUNTY EAST TODAY...WILL KEEP THE LIKELY POPS
GOING THROUGH EARLY TO MID AFTERNOON AND THEN DECREASE THEM AS
SUBSIDENCE OCCURS BEHIND THE VORT MAX. THE HRRR IS NOW KEEPING
SHOWERS GOING LONGER INTO THE AFTERNOON WHICH SEEMS GOOD WITH SOME
MUCH INSTABILITY. MOST MODELS AGREE WITH THIS. CONFIDENCE IS
MODERATE. AS PER THE HRRR MODEL AND SOME SHOWERS ON LAKE HURON
WILL HAVE A THREAT OF SHOWERS AS FAR WEST AS THE ISLANDS. USED A
BLEND OF GUIDANCE FOR THE HIGHS...COOLER EAST BECAUSE OF THE
CLOUDS AND SHOWERS AND WARMER WEST WITH SOME SUNSHINE THIS
AFTERNOON.
WILL MENTION OF THREAT OF SMALL HAIL IN EXTREME NE OH AND NW PA
AND WATERSPOUTS OVER THE EAST END OF THE LAKE. THIS WILL BE IN
GRIDS AND THE HWO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE WILL BE BUILDING IN BUT WITH THE LAKE AND 850 MB
TEMPERATURE DIFFERENCE NEAR 13C SOME LAKE ENHANCED SHOWERS MAY
OCCUR. THE BEST CHANCE WOULD BE NW PA WHERE THE MOISTURE IS A LITTLE
BETTER...ESPECIALLY EARLY TONIGHT. ELSEWHERE SOME CIRRUS WILL BE
MOVING IN FROM THE SOUTHWEST. THIS MAY HELP LIMIT ANY WIDESPREAD
DENSE FOG FROM DEVELOPING...SO WILL NOT MENTION IT AT THIS TIME.
WATCHING THE NEXT WEATHER MAKER FOR THE REGION FROM THE GULF OF
MEXICO. THE 00Z ECMWF IS VERY QUICK WITH THIS SYSTEM...DIDN`T GO AS
FAST AS THE ECMWF BUT DID SPEED THE TIMING OF THE SHOWERS A LITTLE
BIT. LIKELY LOOKS GOOD MONDAY NIGHT INTO TUESDAY AND THEN CHANCE
AFTER THAT AS WE GET CLOSE TO THE WARM SECTOR. AT THIS TIME NO
MENTION OF THUNDER BUT A THREAT WILL EVENTUALLY HAVE TO BE
MENTIONED. NOT CONFIDENT ENOUGH TO FORECAST IT AT THIS TIME.
USED A BLEND OF THE GUIDANCE BUT WITH PLENTY OF CLOUDS AND SHOWERS
AROUND WENT COOLER FOR THE HIGHS AND WARMER FOR THE LOWS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
THE PERIOD WILL START OUT DRY ON THURSDAY AS THE AREA WILL BE
BETWEEN WEATHER SYSTEMS. MODELS CONTINUE TO MOVE NEXT COLD FRONT
ACROSS THE AREA ON FRIDAY. ECMWF CONTINUES TO BE THE FASTER OF THE
2 MODELS. ECMWF HAS THE FRONT JUST EXITING THE AREA BY 12Z FRIDAY
WHILE THE GFS JUST HAS THE FRONT INTO NW OH. CONTINUED TO USE THE
SLOWER GFS FOR FORECAST. MODELS DIFFER SIGNIFICANTLY ON SATURDAY.
ECMWF HAS ANOTHER STRONG COLD FRONT PUSHING ACROSS THE AREA ON
SATURDAY. GFS ON OTHER HAND HAS LARGE LOW SETTING UP OVER JAMES BAY
WITH A SERIES OF TROUGHS SWINGING ACROSS EASTERN LAKES. FOR NOW
WILL CONTINUE WITH THE GFS SOLUTION. LEFT CHANCE POPS SNOWBELT EAST
OF CLEVELAND FOR SATURDAY WITH TROUGH AND IN ADDITION 850 MB TEMPS
DIP TO MINUS 4C SETTING UP POTENTIAL FOR LAKE EFFECT SHOWERS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SURFACE TROUGH SWINGING ACROSS EASTERN PORTION OF FORECAST AREA
NOW KICKING OFF A FEW SHOWERS. WILL BE A BRIEF RESPITE...THEN
UPPER LEVEL VORTICITY MAX NOW OVER LAKE HURON WILL SWING ACROSS
THE AREA SHORTLY AFTER SUNRISE. THIS WILL ALSO KICK OFF A FEW
SHOWERS...BUT DO NOT THINK IT WILL BE ANY WORSE THAN MVFR
CONDITIONS IN THE HEAVIER SHOWERS. AGAIN MOST SHOWERS WILL BE FROM
CLEVELAND EAST. SKIES WILL BEGIN TO SCATTER OUT FROM THE NORTH BY
MID AFTERNOON AS THE VORT MAX SWINGS SOUTH OF THE AREA.
.OUTLOOK...NON-VFR CONDITIONS PROBABLE TUESDAY INTO WEDNESDAY IN
SHRA.
&&
.MARINE...
FLOW WILL BECOME NORTHEAST TODAY BUT CONDITIONS WILL STAY BELOW
SMALL CRAFT ADVISORY CRITERIA. NE FLOW WILL CONTINUE ON SUNDAY AND
THEN BECOME NORTHERLY ON SUNDAY NIGHT AS HIGH PRESSURE BRIEFLY
RETURNS. LOCAL SCHEMES SHOWING A GOOD CHANCE FOR WATERSPOUTS ON
SUNDAY. BEST CHANCES FOR THIS WILL BE TO THE EAST OF CLEVELAND AND
ANYWHERE A DECENT SHOWER DEVELOPS. LOW PRESSURE STILL FORECAST TO
MOVE ACROSS THE OHIO VALLEY ON TUESDAY...AND ACROSS LAKE ERIE
TUESDAY NIGHT. MODELS STILL NOT IN GOOD AGREEMENT ON EXACT TRACK
AND TIMING.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1112 AM EDT SUN SEP 30 2012
.SYNOPSIS...
A DEEP UPPER LOW PRESSURE SYSTEM WILL ROTATE THROUGH NORTHERN
PENNSYLVANIA THIS AFTERNOON...THEN QUICKLY LIFT NORTHWARD AND MOVE
AWAY FROM THE AREA TONIGHT. HIGH PRESSURE WILL BRIEFLY VISIT THE
REGION ON MONDAY. WET WEATHER WILL RETURN TO THE KEYSTONE STATE
MONDAY NIGHT THROUGH TUESDAY AS A WAVE OF LOW PRESSURE EJECTS
NORTHWARD FROM THE CENTRAL GULF STATES.
&&
.NEAR TERM /THROUGH TONIGHT/...
REGIONAL RADAR DOES NOT SHOW MUCH ON THE SCOPE AT OF
15Z...EXCEPT FOR AN AREA OF SHOWERS OVR THE LAUREL HIGHLANDS/SW PA.
STILL EXPECTING NMRS INSTABILITY SHOWERS TO DEVELOP BY THE EARLY
AFTN WITH THE HEATING OF THE DAY /ALBEIT MODEST/...UNDER H5-H7
COLD POOL OF -15C. THIS WILL SUPPORT MID-LVL LAPSE RATES AROUND 7
C/KM WHICH IS A VERY STRONG SIGNAL FOR INSTABILITY SHOWERS. SMALL
HAIL WILL BE POSSIBLE IN THE MORE ROBUST...LOW- TOPPED CONVECTIVE
CELLS. THE LATEST HRRR SHOWS THE GREATEST CONCENTRATION OF SHOWER
ACTIVITY INVOF I-80/N-CENTRAL MTNS WHERE HIGHEST POPS HAVE PAINTED
IN THE GRIDS. ANY PEAKS OF SUN THIS MORNING WILL BE REPLACED BY
SELF-DESTRUCT CUMULUS/STRATOCU WITH BKN SKIES ANTICIPATED ACRS
MUCH OF THE CWA BY LATE MORNING. HIGHS WILL ONLY MAKE IT INTO THE
50S AND 60S...WHICH WILL BE AS MUCH AS 10 DEG BELOW NORMAL IN SOME
AREAS. EXPECT INSTABILITY SHOWERS/ISOLD TSRA TO QUICKLY WEAKEN AND
DISSIPATE WITH THE LOSS OF HEATING INTO TONIGHT. THERE SHOULD ALSO
BE A GRADUAL DECREASE IN CLOUDS AS HIGH PRES BUILDS IN FROM THE
UPPER OH VLY. SOME LLVL MSTR MAY GET TRAPPED BLW INVERSION AND
RESULT IN LOW STRATUS/FOG INTO EARLY MONDAY MORNING...ESP ACRS THE
ALLEGHENIES GIVEN WEAK WNW UPSLOPE. OVERNIGHT LOWS WILL BE NEAR
SEASONAL NORMALS.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AFTER SOME PATCHY EARLY MORNING FOG/LOW CLOUDS...SFC RIDGE WILL
BISECT THE STATE IN BETWEEN DEPARTING NRN STREAM UPPER TROUGH
LIFTING NWD ACRS NRN NEW ENGLAND AND DEVELOPING SRN STREAM WAVE
OF LOW PRES OVR MS/AL. EXPECT AN INCREASE IN MID-HIGH CLOUDS IN
ADVANCE OF THE SRN SYSTEM LATE IN THE DAY...AS IT MOVES NWD INTO
THE TN VLY BY 00Z TUE. HIGHS WILL BE QUITE PLEASANT IN THE 60S TO
LOWER 70S NORTH TO SOUTH.
MDLS IN DECENT AGREEMENT IN MOVG THE SFC WAVE INTO TN/KY BY THE
END OF THE PERIOD. ANOMALOUS SLY LLJ WILL SUPPORT ROBUST NWD MSTR
FLUX INTO THE AREA MON NGT...WITH PWATS SURGING TO +2-3SD BY 12Z
TUE. ANOTHER INTERESTING FEATURE IS PERHAPS A DUEL/INC MSTR FEED
FM THE GOMEX AND ATM RIVER EMANATING FM THE BAHAMAS. THERE ARE
STILL SOME DETAIL DIFFS WITH THE SYS AND WILL REFINE DY2 FCST
BASED ON THE LATER ARRIVING 30/12Z GUID. FOR NOW...FELT THAT AN
INCREASE IN POPS IS JUSTIFIED GIVEN THE STG WAA/ISENT LIFT AND
MSTR TRANSPORT INTO THE REGION.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE LARGE SCALE PATTERN QUICKLY RELOADS INTO A HIGH AMPLITUDE
TROF OVER THE EASTERN HALF OF THE US. THE DETAILS DIFFER BETWEEN
THE VARIOUS MODELS...BUT IT LOOKS LIKE THE CONSENSUS IS FOR A LOW
TO MOVE UP TOWARD THE CENTRAL GR LAKES...WITH THE OCCLUDED FRONT
EVENTUALLY SWINGING THRU THE REGION SOME TIME TUES NIGHT OR WED.
THE SHORT RANGE GUIDANCE SHOWS ERODING STABILITY AND SUGGESTS THE
POSSIBILITY OF SOME CONVECTION AS THE FRONT GETS CLOSER TUES.
03Z SREF STILL SHOWS AS MUCH AS A 30-50 PROB OF 24 HOUR RAINFALLS
OF AN INCH OR MORE OVER WEST-CENTRAL PA...MAINLY FROM TUESDAY INTO
WED. THIS ISN`T MUCH DIFFERENT THAN THE 21Z RUN. THE GEFS IS NOT
NEARLY AS AGGRESSIVE AND HAS SHIFTED ITS LOWER PROBABILITY OF ONE
INCH RAINS MAINLY OFF TO OUR SE...WHICH MATCHES BETTER TO WHERE
THE OPERATIONAL MODEL SUGGESTS THE POSSIBILITY OF A COASTAL
SECONDARY WAVE TO FORM. AT THIS STAGE THE DIFFERENCES IN GUIDANCE
MUDDY THE DETAILS...BUT WHAT LOOKS ALMOST ASSURED IS THAT WE WILL
SEE A WIDESPREAD LIGHT TO MODERATE RAIN...AND A MINIMAL FLOOD
THREAT AT THIS TIME.
AFTER THE SFC LOW/FRONT MOVES THROUGH...THE UPPER LOW WILL THEN
PUSH THROUGH WED/WED NIGHT KEEPING THE MENTION OF SHOWERS IN THE
FORECAST. BY THURSDAY WE SHOULD SEE ENOUGH RIDGING FROM THE WEST
TO DRY OUT...AT LEAST TEMPORARILY.
THE GEFS/GFS AND CANADIAN MODELS SHOW AN APPROACHING ALBEIT FADING
FRONT BY FRIDAY WITH THE PARENT UPPER SHORTWAVE WANTING TO SHEAR
OUT WELL NORTH AND WEST OF HERE. THE ECMWF AT THIS POINT IS AN
OUTLIER...HANGING MORE UPPER ENERGY BACK ITO THE NORTHERN
ROCKIES...RESULTING IN A BROAD WSW FLOW EVENTUALLY ESTABLISHING
OVER THE GR LAKES AND NERN US. THIS RESULTS IN THE MODEL
DEVELOPING A SLOW MOVING WAVY ANA-FRONT THAT APPROACHES THE AREA FOR
THE WEEKEND. DEPENDING ON TIMING...IT COULD EITHER BE MILD AND
DRY...OR CHILLY AND RAINY. AS A RESULT...HAVE CHOSEN TO NOT TOUCH
THE EXTENDED PORTION OF THE FORECAST WHERE WE NOW HAVE SMALL
CHANCES FOR RAIN...WHICH WOULD BETTER FIT A WASHING FRONTAL
PASSAGE CONCEPTUAL MODEL.
IT DOES LOOK LIKE ONCE THE RAIN MOVES THROUGH...WE SHOULD ENJOY
SEVERAL DAYS OF ABOVE NORMAL WARMTH STARTING ABOUT WEDNESDAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
30/15Z...COLD AIR ALOFT AND DAYTIME HEATING WILL RESULT IN BKN
CU/SC FIELD ACRS CENTRAL PA TERMINALS BY THE EARLY AFTN. CLOUDS
BASES WILL BE IN THE LOW END VFR RANGE BTWN 3.5-6KFT AGL. IN
ADDITION...EXPECT SCT TO NMRS INSTABILITY SHOWERS TO DEVELOP UNDER
THE COLD POOL ALOFT ASSOC WITH A CLOSED UPPER LEVEL LOW PIVOTING
OVR PA/NY THIS AFTN. THERE MAY ALSO BE AN ISOLD TSRA BUT WILL
CVRG/CONFIDENCE TOO LOW FOR MENTION IN TAFS ATTM. WITH THE LOSS OF
DAYTIME HEATING...EXPECT SHOWERS TO QUICKLY DISSIPATE AFT 00Z.
SFC HIGH PRES WILL SLIDE INTO THE REGION FROM THE UPPER OH VLY
OVERNIGHT. SOME RESIDUAL LLVL MSTR MAY GET TRAPPED UNDER INVERSION
AND RESULT IN LOW CIGS/FOG OVERNIGHT...ESP OVR THE WRN MTNS GIVEN
WEAK UPSLOPE FLOW.
OUTLOOK...
MON...AM LOW CIGS/FOG POSSIBLE ACROSS THE W MTNS...BCMG VFR.
TUE...RAIN/LOW CIGS LIKELY...ESP OVR THE CENTRAL MTNS.
WED...RAIN/LOW CIGS POSSIBLE.
THU...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...LA CORTE/STEINBUGL
LONG TERM...LA CORTE
AVIATION...MARTIN/STEINBUGL
AREA FORECAST DISCUSSION
NWS NEW YORK NY
133 PM EDT SUN SEP 30 2012
.SYNOPSIS...
A BROAD UPPER LEVEL STORM SYSTEM IMPACTS THE NORTHEAST INTO
MONDAY. WEAK HIGH PRESSURE BUILDS IN MONDAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM...WHICH WILL PASS THROUGH MID
WEEK. HIGH PRESSURE BRIEFLY BUILDS IN THE END OF THE WEEK BEFORE
THE NEXT FRONT APPROACHES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST WATER VAPOR AND RUC ANALYSIS SHOW CUTOFF LOW ALOFT CENTERED
NEAR THE CENTRAL NY/PA BORDER...WITH A 38 UNIT 500 HPA VORTICITY
MAXIMUM ALONG THE S SHORE OF LONG ISLAND LIFTING NE. AHEAD OF THIS
VORTICITY MAXIMUM - STRONG POSITIVE VORTICITY ADVECTION - THERE
ARE ISOLD- SCT SHRA...AND BEHIND IT - NEGATIVE VORTICITY ADVECTION
- DRY CONDITIONS WITH MAINLY FEW-SCT CLOUD COVERAGE.
THE NEXT VORTICITY MAXIMUM APPROACHES WESTERN ZONES BY LATE
AFTERNOON...SO INTRODUCE ISOLD-SCT SHRA THERE.
A BLEND OF NAM/SREF/HRRR POPS REFLECTS PRECIPITATION TREND FAIRLY
WELL...THOUGH MIGHT BE UNDER DOING AREA TO BE MAINLY DRY THIS
AFTERNOON. CMC-REG SKY PRODUCT HAS HANDLED SKY COVER THIS MORNING
WELL...SO HAVE USED IT TO UPDATE SKY GRIDS.
NO LIGHTNING HAS BEEN OBSERVED OVER THE NE UNITED STATES OVER THE
PAST SEVERAL HOURS...AND GIVEN THIS TREND...HAVE REMOVED THE
MENTION OF THUNDER FROM THE FORECAST FOR THIS AFTERNOON.
12Z KOKX AND KALY SOUNDINGS SUGGEST HIGHS RANGING FROM THE LOWER
60S ACROSS THE NORTHERN INTERIOR TO THE MID-UPPER 60S NEAR THE
COAST. THIS IS CONSISTENT WITH A BLEND OF 12Z MET/MAV/NAM 2-METER
TEMPERATURES. HOURLY AND HIGH TEMPERATURE GRIDS ADJUSTED
ACCORDINGLY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
DRYING CONDITIONS THIS PERIOD AS THE UPPER LEVEL LOW FINALLY
PUSHES OFF TO THE NORTHEAST...ALLOWING FOR RIDGING TO BUILD IN ON
MONDAY. THE SURFACE LOW MOVES OFF TO THE NORTH AS WELL...DRAGGING
A TROUGH THROUGH THE CWA...RESULTING IN A MORE WESTERLY FLOW TO
THE WEST...AND A SOUTHWESTERLY FLOW OVER THE EAST. A TIGHTENING
PRESSURE GRADIENT BETWEEN THE DEPARTING LOW AND APPROACHING HIGH
FROM THE SOUTH WILL INCREASE WINDS LATE SUNDAY NIGHT INTO
MONDAY...WITH GUSTS BETWEEN 15 AND 20 MPH POSSIBLE. SOUNDINGS
INDICATE DRYING AT ALL LEVELS AS THE LOW MOVES AWAY AND COOLER AIR
IS USHERED IN ON THE BACKSIDE OF THE LOW...CREATING PLENTY OF SUBSIDENCE
FOR MONDAY. OTHER THAN A FEW LINGERING SHOWERS THIS
EVENING...SHOULD HAVE A DRY FORECAST UNTIL MONDAY NIGHT WHEN THE
FLOW RETURNS TO THE SOUTH AND THE MOISTURE FIELD BEGINS
INCREASING.
GFS THE WARMEST WITH TEMPS WITH IT PUSHING THE LOW OUT THE
QUICKEST. SIDED WITH THE SLIGHTLY SLOWER NAM GUIDANCE FOR
TEMPS...WHICH KEEPS TEMPS NEAR NORMAL. IF SKIES CLEAR QUICKER THAN
FORECASTED...COULD SEE TEMPS DROP ANOTHER COUPLE OF DEGREES...ESP
INLAND.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
OVERALL...UNSETTLED WEATHER STILL FORECASTED FOR MID WEEK...WITH
A BREAK IN THE PRECIPITATION POSSIBLE THURS/FRI. WHILE MODEL
DISCREPANCIES ARE STILL IN PLACE...THERE IS SOME BETTER ALIGNMENT
WITH THE 00Z RUNS...ALLOWING FOR SLIGHTLY HIGHER CONFIDENCE ON THE
FORECAST.
WEAK HIGH PRESSURE AT THE SURFACE BEGINS TO RETREAT TUESDAY AS A
WARM FRONT ASSOCIATED WITH A SURFACE LOW OVER THE OHIO RIVER
VALLEY APPROACHES AND MOVES THROUGH THE NORTHEAST. DESPITE
DIFFERENCES IN THE EXACT TIMING...GENERAL MODEL CONSENSUS IS A TAD
SLOWER WITH THE PROGRESSION OF THE LOW AND ITS ASSOCIATED
FRONTS. 00Z NAM REMAINS THE MAIN OUTLIER WITH TIMING...REALLY
SLOWING EVERYTHING DOWN TILL WED. HOWEVER...DECIDED TO SIDE WITH
THE MORE CONSISTENT AND PROGRESSIVE PATHS...BRINGING THE
PRECIPITATION IN BY TUES NIGHT. KEPT CHANCE POPS IN FOR TUES
MORNING WITH INCREASING WAA/MOISTURE FIELD...THEN INCREASED POPS
THROUGHOUT THE DAY INTO TUES NIGHT ALONG THE ISENTROPIC LIFT. ALSO
TIMED PRECIPITATION OUT TO CORRESPOND WITH PASSING SHORTWAVES
ALONG THE NORTHERN FRINGE OF THE UPPER LEVEL RIDGE.
CHANCE OF PRECIPITATION REMAINS MENTIONED THROUGH WED ALONG THE
PASSAGE OF THE COLD FRONT/SURFACE LOW. HOWEVER...WITH RIDGING IN
PLACE ALOFT...EXPECT THINGS TO DRY OUT RATHER QUICKLY ONCE THE
FRONT PASSES. SURFACE HIGH PRESSURE BUILDS IN FROM THE SOUTH THURS
INTO FRI...WHICH SHOULD KEEP THE DRY WEATHER IN PLACE. ANOTHER
STORM SYSTEM IS EXPECTED TO IMPACT THE AREA THIS WEEKEND...BUT
TIMING IS STILL UNCERTAIN AT THIS TIME. THUS...CONTINUED PREVIOUS
FORECAST FOR THE END OF THE WEEK DUE TO THESE UNCERTAINTIES.
WAA AHEAD OF THE COLD FRONT MID WEEK WILL PUSH TEMPS BACK TO ABOVE
NORMAL TUES THROUGH THURS...WITH CLOUDY CONDITIONS AND RAIN
MODERATING TEMPS. SLIGHT COOLING SETTLES IN FRI...BUT THE NEXT
BURST OF COOLER AIR LOOKS TO BE AFTER THE FRONT THIS WEEKEND.
GENERALLY WENT WITH A BLEND OF HPC/MOS GUIDANCE FOR TEMPS AND DEW
POINTS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
LOW PRES OVER THE GULF OF ME WILL CONTINUE TO TRACK N TNGT.
MAINLY VFR THRU THE TAF PERIOD. MVFR AT KGON WILL IMPROVE THRU THE
REMAINDER OF THE AFTN. ELSEWHERE...ISOLD-SCT SHRA WILL DEVELOP
ACROSS NJ AND UPSTATE NY. VCSH HAS BEEN INCLUDED FOR KTEB AND
KEWR. POTENTIAL FOR THESE SHRA TO GET INTO KLGA AND KJFK.
THERE COULD BE AN ISOLD TSTM EMBEDDED IN THE DEVELOPING
SHRA...WITH SMALL HAIL POSSIBLE.
SHRA DISSIPATE THIS EVE...WITH DRY CONDITIONS THEREAFTER THRU THE
TAF PERIOD.
VRB WIND FLOW WILL BACK TO THE W. SOME GUSTS AROUND 18KT POSSIBLE.
FLOW DECREASES TNGT...THEN WINDS INCREASE AGAIN MON MRNG.
W DIRECTION IS EXPECTED TO REMAIN NEARLY THE SAME THRU THE TAF
PERIOD AFT THE SHIFT OCCURS.
OUTLOOK FOR 18Z MONDAY-FRIDAY...
.MONDAY AFTN-MONDAY NIGHT...VFR. GUSTS ARE POSSIBLE DURING THE
DAY.
.TUESDAY-WEDNESDAY...MVFR OR LOWER LIKELY. PERIODS OF -RA
POSSIBLE.
.THURSDAY...MRNG MVFR OR LOWER POSSIBLE. IMPROVEMENT TO VFR BY
AFTN.
.FRIDAY...VFR.
&&
.MARINE...
MINOR CHANGES MADE IN THE GRIDS TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
SUB-SCA CONDITIONS TODAY WITH A NORTHERLY TO WESTERLY FLOW BETWEEN
5 AND 10 KTS. AS THE LOW DEPARTS TOMORROW AND THE HIGH BUILDS
IN...TIGHTENING PRESSURE GRADIENT WILL INCREASE BOTH WINDS AND
SEAS...WITH POSSIBLE GUSTS UP TO 25 KTS. THE PERSISTENT FLOW COULD
INCREASE SEAS TO 5 FT ON THE OCEAN WATERS.
WINDS AND SEAS DIMINISH BY TUESDAY AND SHOULD REMAIN SUB SCA FOR
THE REMAINDER OF THE FORECAST. OCCASIONAL HIGHER GUSTS POSSIBLE
WITH THE PASSAGE OF THE FRONT ON WED.
&&
.HYDROLOGY...
SIGNIFICANT PRECIPITATION IS NOT EXPECTED THROUGH SUNDAY NIGHT.
A PROLONGED PERIOD OF STRATIFORM RAIN IS POSSIBLE FROM LATE
MONDAY NIGHT INTO WEDNESDAY. SINCE THIS WILL BE A LONG DURATION
EVENT AND HEAVY RAIN IS NOT EXPECTED AT THIS TIME...FLOODING DOES
NOT APPEAR TO BE A CONCERN.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SEARS
NEAR TERM...MALOIT
SHORT TERM...SEARS
LONG TERM...SEARS
AVIATION...JMC
MARINE...MALOIT/SEARS
HYDROLOGY...SEARS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1224 PM EDT SUN SEP 30 2012
.SYNOPSIS...
A BROAD UPPER LEVEL STORM SYSTEM IMPACTS THE NORTHEAST INTO
MONDAY. WEAK HIGH PRESSURE BUILDS IN MONDAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM...WHICH WILL PASS THROUGH MID
WEEK. HIGH PRESSURE BRIEFLY BUILDS IN THE END OF THE WEEK BEFORE
THE NEXT FRONT APPROACHES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST WATER VAPOR AND RUC ANALYSIS SHOW CUTOFF LOW ALOFT CENTERED
NEAR THE CENTRAL NY/PA BORDER...WITH A 38 UNIT 500 HPA VORTICITY
MAXIMUM ALONG THE S SHORE OF LONG ISLAND LIFTING NE. AHEAD OF THIS
VORTICITY MAXIMUM - STRONG POSITIVE VORTICITY ADVECTION - THERE
ARE ISOLD- SCT SHRA...AND BEHIND IT - NEGATIVE VORTICITY ADVECTION
- DRY CONDITIONS WITH MAINLY FEW-SCT CLOUD COVERAGE.
THE NEXT VORTICITY MAXIMUM APPROACHES WESTERN ZONES BY LATE
AFTERNOON...SO INTRODUCE ISOLD-SCT SHRA THERE.
A BLEND OF NAM/SREF/HRRR POPS REFLECTS PRECIPITATION TREND FAIRLY
WELL...THOUGH MIGHT BE UNDER DOING AREA TO BE MAINLY DRY THIS
AFTERNOON. CMC-REG SKY PRODUCT HAS HANDLED SKY COVER THIS MORNING
WELL...SO HAVE USED IT TO UPDATE SKY GRIDS.
NO LIGHTNING HAS BEEN OBSERVED OVER THE NE UNITED STATES OVER THE
PAST SEVERAL HOURS...AND GIVEN THIS TREND...HAVE REMOVED THE
MENTION OF THUNDER FROM THE FORECAST FOR THIS AFTERNOON.
12Z KOKX AND KALY SOUNDINGS SUGGEST HIGHS RANGING FROM THE LOWER
60S ACROSS THE NORTHERN INTERIOR TO THE MID-UPPER 60S NEAR THE
COAST. THIS IS CONSISTENT WITH A BLEND OF 12Z MET/MAV/NAM 2-METER
TEMPERATURES. HOURLY AND HIGH TEMPERATURE GRIDS ADJUSTED
ACCORDINGLY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
DRYING CONDITIONS THIS PERIOD AS THE UPPER LEVEL LOW FINALLY
PUSHES OFF TO THE NORTHEAST...ALLOWING FOR RIDGING TO BUILD IN ON
MONDAY. THE SURFACE LOW MOVES OFF TO THE NORTH AS WELL...DRAGGING
A TROUGH THROUGH THE CWA...RESULTING IN A MORE WESTERLY FLOW TO
THE WEST...AND A SOUTHWESTERLY FLOW OVER THE EAST. A TIGHTENING
PRESSURE GRADIENT BETWEEN THE DEPARTING LOW AND APPROACHING HIGH
FROM THE SOUTH WILL INCREASE WINDS LATE SUNDAY NIGHT INTO
MONDAY...WITH GUSTS BETWEEN 15 AND 20 MPH POSSIBLE. SOUNDINGS
INDICATE DRYING AT ALL LEVELS AS THE LOW MOVES AWAY AND COOLER AIR
IS USHERED IN ON THE BACKSIDE OF THE LOW...CREATING PLENTY OF SUBSIDENCE
FOR MONDAY. OTHER THAN A FEW LINGERING SHOWERS THIS
EVENING...SHOULD HAVE A DRY FORECAST UNTIL MONDAY NIGHT WHEN THE
FLOW RETURNS TO THE SOUTH AND THE MOISTURE FIELD BEGINS
INCREASING.
GFS THE WARMEST WITH TEMPS WITH IT PUSHING THE LOW OUT THE
QUICKEST. SIDED WITH THE SLIGHTLY SLOWER NAM GUIDANCE FOR
TEMPS...WHICH KEEPS TEMPS NEAR NORMAL. IF SKIES CLEAR QUICKER THAN
FORECASTED...COULD SEE TEMPS DROP ANOTHER COUPLE OF DEGREES...ESP
INLAND.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
OVERALL...UNSETTLED WEATHER STILL FORECASTED FOR MID WEEK...WITH
A BREAK IN THE PRECIPITATION POSSIBLE THURS/FRI. WHILE MODEL
DISCREPANCIES ARE STILL IN PLACE...THERE IS SOME BETTER ALIGNMENT
WITH THE 00Z RUNS...ALLOWING FOR SLIGHTLY HIGHER CONFIDENCE ON THE
FORECAST.
WEAK HIGH PRESSURE AT THE SURFACE BEGINS TO RETREAT TUESDAY AS A
WARM FRONT ASSOCIATED WITH A SURFACE LOW OVER THE OHIO RIVER
VALLEY APPROACHES AND MOVES THROUGH THE NORTHEAST. DESPITE
DIFFERENCES IN THE EXACT TIMING...GENERAL MODEL CONSENSUS IS A TAD
SLOWER WITH THE PROGRESSION OF THE LOW AND ITS ASSOCIATED
FRONTS. 00Z NAM REMAINS THE MAIN OUTLIER WITH TIMING...REALLY
SLOWING EVERYTHING DOWN TILL WED. HOWEVER...DECIDED TO SIDE WITH
THE MORE CONSISTENT AND PROGRESSIVE PATHS...BRINGING THE
PRECIPITATION IN BY TUES NIGHT. KEPT CHANCE POPS IN FOR TUES
MORNING WITH INCREASING WAA/MOISTURE FIELD...THEN INCREASED POPS
THROUGHOUT THE DAY INTO TUES NIGHT ALONG THE ISENTROPIC LIFT. ALSO
TIMED PRECIPITATION OUT TO CORRESPOND WITH PASSING SHORTWAVES
ALONG THE NORTHERN FRINGE OF THE UPPER LEVEL RIDGE.
CHANCE OF PRECIPITATION REMAINS MENTIONED THROUGH WED ALONG THE
PASSAGE OF THE COLD FRONT/SURFACE LOW. HOWEVER...WITH RIDGING IN
PLACE ALOFT...EXPECT THINGS TO DRY OUT RATHER QUICKLY ONCE THE
FRONT PASSES. SURFACE HIGH PRESSURE BUILDS IN FROM THE SOUTH THURS
INTO FRI...WHICH SHOULD KEEP THE DRY WEATHER IN PLACE. ANOTHER
STORM SYSTEM IS EXPECTED TO IMPACT THE AREA THIS WEEKEND...BUT
TIMING IS STILL UNCERTAIN AT THIS TIME. THUS...CONTINUED PREVIOUS
FORECAST FOR THE END OF THE WEEK DUE TO THESE UNCERTAINTIES.
WAA AHEAD OF THE COLD FRONT MID WEEK WILL PUSH TEMPS BACK TO ABOVE
NORMAL TUES THROUGH THURS...WITH CLOUDY CONDITIONS AND RAIN
MODERATING TEMPS. SLIGHT COOLING SETTLES IN FRI...BUT THE NEXT
BURST OF COOLER AIR LOOKS TO BE AFTER THE FRONT THIS WEEKEND.
GENERALLY WENT WITH A BLEND OF HPC/MOS GUIDANCE FOR TEMPS AND DEW
POINTS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
LOW PRES E OF CAPE COD WILL CONTINUE TO TRACK N TODAY.
LIGHT N/NW FLOW WILL BACK TO THE WNW THIS AFTN. SPEEDS WILL
INCREASE INTO THE 10-15KT RANGE AFT 18Z.
VFR IS OVERSPREADING THE REGION FROM THE SW. THIS TREND IS
EXPECTED TO CONTINUE. CU IS EXPECTED TO BEGIN TO DEVELOP IN THE
16-18Z PERIOD. ISOLD-SCT SHRA ARE POSSIBLE...HOWEVER THE BULK OF
THIS ACTIVITY IS PROGGED TO BE N OF THE CITY TERMINALS. ANY SHRA
DISSIPATE BY 23-00Z.
TONIGHT...WINDS REMAIN FROM THE WEST AROUND 10 KT OR LESS WITH VFR
CONDITIONS.
OUTLOOK FOR 12Z MONDAY-THURSDAY...
.MONDAY-MONDAY NIGHT...VFR. GUSTS ARE POSSIBLE DURING THE DAY MONDAY.
.TUESDAY-WEDNESDAY...MVFR OR LOWER CONDITIONS POSSIBLE IN SHRA.
.WEDNESDAY NIGHT-THURSDAY...VFR.
&&
.MARINE...
MINOR CHANGES MADE IN THE GRIDS TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
SUB-SCA CONDITIONS TODAY WITH A NORTHERLY TO WESTERLY FLOW BETWEEN
5 AND 10 KTS. AS THE LOW DEPARTS TOMORROW AND THE HIGH BUILDS
IN...TIGHTENING PRESSURE GRADIENT WILL INCREASE BOTH WINDS AND
SEAS...WITH POSSIBLE GUSTS UP TO 25 KTS. THE PERSISTENT FLOW COULD
INCREASE SEAS TO 5 FT ON THE OCEAN WATERS.
WINDS AND SEAS DIMINISH BY TUESDAY AND SHOULD REMAIN SUB SCA FOR
THE REMAINDER OF THE FORECAST. OCCASIONAL HIGHER GUSTS POSSIBLE
WITH THE PASSAGE OF THE FRONT ON WED.
&&
.HYDROLOGY...
SIGNIFICANT PRECIPITATION IS NOT EXPECTED THROUGH SUNDAY NIGHT.
A PROLONGED PERIOD OF STRATIFORM RAIN IS POSSIBLE FROM LATE
MONDAY NIGHT INTO WEDNESDAY. SINCE THIS WILL BE A LONG DURATION
EVENT AND HEAVY RAIN IS NOT EXPECTED AT THIS TIME...FLOODING DOES
NOT APPEAR TO BE A CONCERN.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SEARS
NEAR TERM...MALOIT
SHORT TERM...SEARS
LONG TERM...SEARS
AVIATION...BC/JMC
MARINE...MALOIT/SEARS
HYDROLOGY...SEARS
AREA FORECAST DISCUSSION
NWS MIAMI FL
204 PM EDT SUN SEP 30 2012
.AVIATION...VFR WILL PREVAIL. EAST COAST SEA BREEZE HAS MOVED
INLAND FROM THE EAST COAST TERMINALS SO REMOVED VCTS THERE, BUT
KEPT IT FOR KAPF AS TSTORMS COULD BE IN THE VICINITY. INCLUDED
VCSH ALL EAST COAST TERMINALS OVERNIGHT. SHOWERS ARE MOST LIKELY
IN THE VICINITY TOWARDS DAWN MON. VCTS ALL TERMINALS FOR MON. IT
COULD BECOME WET AND MAY NEED TO ADD TEMPO`S DOWN THE ROAD. BRIEF
IFR POSSIBLE MON. ONSHORE WINDS WILL BECOME LIGHT OVERNIGHT THEN
SOUTHERLY ON MON. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 1022 AM EDT SUN SEP 30 2012/
UPDATE...BASED ON CURRENT TRENDS AND OBSERVATIONS, DO NOT PLAN TO
MAKE ANY CHANGES WITH THE MORNING UPDATES. THE 12Z MFL SOUNDING
WAS CONTAMINATED IN THE LOWEST LEVELS SO THE PWAT VALUE WAS
CALCULATED WAY TOO LOW. HOWEVER, IT DOES SHOW A GENERAL INCREASE
IN MOISTURE THROUGH THE MID LEVELS AND BASED ON THIS IT APPEARS
THE PWAT HAS PROBABLY INCREASED BACK CLOSE TO TWO INCHES. IT
DEPICTS ONLY A MARGINALLY UNSTABLE AIRMASS SO THE 30-40 PERCENT
POPS LOOK REASONABLE. THE HRRR DOES INDICATE NNW STORM MOTION WITH
SCATTERED COVERAGE AND THIS ALSO SEEMS REASONABLE GIVEN ABOVE
DISCUSSION.
KOB
PREV DISCUSSION... /ISSUED 727 AM EDT SUN SEP 30 2012/
AVIATION...ISOLATED SHRA MOVING NW THROUGH THE ATLC WATERS AND
GULF WATERS AT THIS TIME WITH THE ACTIVITY OCCASIONALLY MOVING
UPON THE E COAST. HAVE VCSH INITIALLY IN E COAST TAFS AND VERY
BRIEF MVFR CIG POSSIBLE. CURRENT E COAST SURFACE WINDS CALM TO
LIGHT SE WITH SEA BREEZE INCREASING SE 10 TO 12 KNOTS AFT 16Z.
TSRA TO DEVELOP MAINLY ALONG THE SEA BREEZE WITH VCTS IN TAFS AFT
17/18Z. TSRA MAY BE FAR ENOUGH INLAND TO AFFECT ONLY KTMB AND
KPBI. AT KAPF ...SHRA SHOULD REMAIN OFFSHORE WITH VCTS IN TAFS AFT
18Z THROUGH 30/00Z. AT KAPF CURRENT SURFACE WIND CALM BECOMING
ESE-SE < 10 KNOTS AFT 13Z THEN SSW-SW TO 10 KNOTS AFT 16Z AS W
COAST SEA BREEZE DEVELOPS.
PREV DISCUSSION... /ISSUED 307 AM EDT SUN SEP 30 2012/
POTENTIAL FOR HEAVY RAIN AND LOCALIZED FLOODING ACROSS SOUTH FLORIDA MONDAY AND TUESDAY...
DISCUSSION...
WATER VAPOR ANALYSIS FROM THIS MORNING SHOWED A LARGE UPPER LOW
SPINNING OVER THE LOWER GREAT LAKES...AND ANOTHER CUT OFF LOW OVER
OKLAHOMA. UPPER LEVEL HIGH PRESSURE WAS LOCATED ACROSS THE PACIFIC
AND WEST COAST AND OUT ACROSS THE WESTERN ATLANTIC. AT THE
SURFACE...LOW PRESSURE WAS LOCATED ACROSS EAST TEXAS AND A WEAK
FRONT WAS ACROSS THE SOUTHEAST AND INTO THE WESTERN ATLANTIC. A WEAK
RIDGE AXIS WAS LOCATED FROM THE WESTERN ATLANTIC ACROSS THE LAKE
OKEECHOBEE REGION. FOR SOUTH FLORIDA...LOW LEVEL SOUTHEAST FLOW HAS
BEGUN...BUT DEEP MOISTURE WAS STILL LOCATED OVER THE CARIBBEAN. SOME
DRIER AIR WAS ALSO NOTED OVER THE YUCATAN NORTHEASTWARD TO OFF WEST
COAST OF SOUTH FLORIDA.
A SHORTWAVE IS EXPECTED TO DIVE SOUTHEAST ACROSS THE PACIFIC
NORTHWEST...AND THE CUT OFF LOW IS EXPECTED TO DEEPEN ACROSS THE
ARKLATEX REGION. THIS WILL AMPLIFY THE UPPER PATTERN THROUGH THE
MIDDLE OF THE WEEK...WITH A DEEP TROUGH ACROSS THE SOUTH AND STRONG
RIDGES ACROSS THE WEST COAST AND OVER THE WESTERN ATLANTIC. DEEP
SOUTH TO SOUTHWEST FLOW WILL DEVELOP OVER SOUTH FLORIDA...PULLING
TROPICAL MOISTURE OUT OF THE CARIBBEAN OVER THE REGION LATE TONIGHT
THROUGH TUESDAY. SINCE MODELS HAVE SLOWED DOWN THE TIMING OF THE
DEEP TROPICAL MOISTURE UNTIL TONIGHT...AND WITH WARM AND DRY AIR
ALOFT...500MB TEMPS AROUND -4C TO -5C...CUT BACK POPS SLIGHTLY
FOR TODAY. WENT WITH A BLEND OF MAV AND ECMWF FOR THE POPS...WITH
STILL A CHANCE OF STORMS ACROSS THE REGION. EXPECT MAINLY SEA
BREEZE ACTIVITY...WITH OVERALL STORM MOTION SLOW TO THE NORTH.
THE UPPER LOW OVER THE NORTHEAST CONUS WILL SLOWLY SLIDE TO THE
NORTHEAST...AND SURFACE LOW PRESSURE WILL MOVE ACROSS THE NORTHERN
GULF AND INTO THE SOUTHEAST STATES EARLY NEXT WEEK. A COLD FRONT
ATTACHED TO THE SURFACE LOW WILL MOVE INTO THE CENTRAL/EASTERN
GULF ON MONDAY AND THEN INTO CENTRAL FLORIDA AND NEAR LAKE
OKEECHOBEE ON TUESDAY.
SO FOR MONDAY...PWATS WILL INCREASE TO AROUND 2.1-2.4
INCHES...AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. ALTHOUGH STORM
MOTION IS NOT TERRIBLY SLOW...AROUND 10 KNOTS TO THE
NORTHEAST...WITH THE DEEP MOISTURE AND SATURATED SOILS ACROSS SOUTH
FLORIDA THERE WILL A POTENTIAL FOR LOCALLY HEAVY RAINFALL. HPC
PAINTS AROUND 1 INCH OF RAIN AREAL AVERAGE ACROSS THE ENTIRE
EASTERN TWO-THIRDS OF SOUTH FLORIDA...SO LOCALIZED SPOTS COULD
SEE 2 TO 4 INCHES OF RAIN AND POSSIBLY MORE. SO LOCALIZED
FLOODING IS THE BIGGEST CONCERN. FLASH FLOOD GUIDANCE IS NOT STILL
RELATIVELY HIGH...3-4 INCHES FOR 1 HOUR...AROUND 4 INCHES FOR 3
HOURS...AND 4-5.5 INCHES FOR 6 HOURS. WITH NO REAL FOCUS FOR
STORMS AND CLOUD COVER POSSIBLY HAMPERING OVERALL ACTIVITY...WILL
NOT ISSUE A FLOOD WATCH AT THIS TIME. WENT BELOW GUIDANCE BY A FEW
DEGREES FOR HIGH TEMPERATURES DUE TO EXPECTED CLOUD COVER AND
RAINFALL ON MONDAY.
SOME OF THE DRIER AIR PREVIOUSLY MENTIONED ACROSS THE
EASTERN GULF AND TOWARDS THE YUCATAN MAY TRY TO PUSH INTO THE GULF
COAST OF SOUTH FLORIDA MONDAY NIGHT DUE TO THE SOUTHWEST FLOW
ALOFT. HOWEVER...HIGH PRESSURE ACROSS THE WESTERN ATLANTIC WILL
BEGIN TO STRENGTHEN AND BATTLE BACK AGAINST THE TROUGH OVER THE
SOUTH...AND THE DEEP MOISTURE IS FORECAST TO PUSH BACK ACROSS AT
LEAST THE EASTERN TWO-THIRDS OF THE REGION ON TUESDAY. HEIGHTS
WILL BEGIN TO RISE ACROSS THE REGION...BUT THERE WILL BE ANOTHER
CHANCE FOR LOCALLY HEAVY RAINFALL...MAINLY FOR THE EAST COAST
METRO AREAS.
HIGH PRESSURE WILL CONTINUE TO STRENGTHEN ACROSS THE WESTERN
ATLANTIC TUESDAY NIGHT INTO WEDNESDAY WITH HEIGHTS OF 596-598
DECAMETERS...AND 592-593 DECAMETERS ACROSS SOUTH FLORIDA. THE FLOW
WILL BECOME MORE SOUTHEASTERLY AS HIGH PRESSURE BUILDS IN...AND THE
DEEP MOISTURE WILL BEGIN TO GET PUSHED TO THE NORTHWEST. PWATS WILL
FALL TO 1.8 TO 2 INCHES ACROSS THE REGION...HIGHEST ACROSS THE
NORTHWEST. THE PERSISTENT TROUGH OVER THE DEEP SOUTH WILL BEGIN TO
LIFT TO THE NORTHEAST AS ANOTHER TROUGH DIGS INTO THE NORTHERN
PLAINS ON THURSDAY...AND HIGH PRESSURE WILL BEGIN TO WEAKEN OVER THE
WESTERN ATLANTIC. SURFACE HIGH PRESSURE WILL DEVELOP OVER THE
SOUTHEAST AND EASTERLY FLOW WILL DEVELOP ACROSS THE REGION...WITH
MORE TYPICAL SEA BREEZE TYPE CONVECTION. HOWEVER...A WEAK BOUNDARY
WILL REMAIN OVER CENTRAL FLORIDA OR NEAR LAKE OKEECHOBEE...KEEPING
RELATIVELY HIGH LEVELS OF MOISTURE...PWATS NEAR 2 INCHES...INTO THE
WEEKEND. SO RAIN CHANCES WILL REMAIN AT OR ABOVE NORMAL THROUGH NEXT
SATURDAY. TEMPERATURES ARE EXPECTED TO REMAIN NEAR NORMAL THROUGH
THE PERIOD.
AVIATION...FOR 06Z TAFS.
WIDELY SCATTERED SHRA MOVING NW THROUGH THE
ATLC WATERS AND GULF WATERS WITH THE ACTIVITY OCCASIONALLY MOVING
UPON THE E COAST. VERY BRIEF MVFR CIG POSSIBLE. VCSH IN E COAST
TAFS. E COAST SEA BREEZE INCREASES SE WINDS AFT 16Z AND TSRA TO
DEVELOP MAINLY ALONG THE SEA BREEZE WITH VCTS IN TAFS. POTENTIAL
THAT TSRA MAY BE FAR ENOUGH INLAND TO AFFECT MAINLY KTMB AND KPBI.
AT KAPF...SHRA SHOULD REMAIN OFFSHORE WITH VCTS AFT 18Z THROUGH
30/00Z. E COAST SURFACE WINDS CURRENTLY CALM TO SE-SSE < 5 KNOTS
UNLESS BECOMING VARIABLE FOR A SHORT PERIOD OF TIME IF A SHRA
MOVES OVER THE AREA...BECOMING SE 10-12 KNOTS AFT 15Z. AT KAPF
CURRENT SURFACE WIND CALM TO SE < 5 KNOTS INCREASING AFT 12Z 5 TO
8 KNOTS THEN SHIFTING SSW-SW TO 10 KNOTS AFT 16Z AS W COAST SEA
BREEZE DEVELOPS.
MARINE...
WIND AND SEAS WILL REMAIN QUITE TRANQUIL THROUGH THE
WEEKEND WITH LIGHT SOUTHEAST FLOW BECOMING MORE SOUTHERLY ON
SUNDAY. A STRONGER SOUTH WIND WILL BEGIN TO DEVELOP MONDAY AND
TUESDAY IN RESPONSE TO THE DEVELOPING LOW PRESSURE WITH SEAS
POSSIBLY BUILDING TO AROUND 4 FEET.
FIRE WEATHER...
NO PROBLEMS OR CONCERNS WITH HIGH LOW LEVEL MOISTURE IN PLACE THIS
WEEKEND AND ALL OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 77 87 77 / 30 30 70 50
FORT LAUDERDALE 89 76 86 77 / 30 40 70 50
MIAMI 88 78 86 77 / 30 40 70 50
NAPLES 89 77 89 77 / 20 20 60 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
242 PM CDT SUN SEP 30 2012
.DISCUSSION...
1111 AM CDT
FOR MORNING UPDATE...
ONLY MINOR TWEAKS TO HOURLY SKY COVER GRIDS MADE THIS MORNING...WITH
FORECAST GENERALLY RIGHT ON TRACK.
COLD FRONT WHICH PASSED ACROSS THE AREA LAST EVENING WAS OVER THE
OHIO VALLEY AT MID-MORNING...WITH WEAK HIGH PRESSURE SPREADING
ACROSS THE NORTHERN GREAT LAKES. NORTHEAST SURFACE WINDS WERE
PROVIDING COOLER LOW LEVEL AIR TO THE REGION...WITH A SOME
LAKE-INDUCED STRATOCU MOVING INLAND OFF OF LAKE MICHIGAN INTO
NORTHEAST IL. STRATOCU LAYER IS EXPECTED TO DECREASE IN COVERAGE AS
WE HEAD INTO THE AFTERNOON HOURS...THANKS TO WARMING TEMPS ABOVE THE
BOUNDARY LAYER IN RESPONSE TO LARGE SCALE SUBSIDENCE ASSOCIATED WITH
AFOREMENTIONED HIGH PRESSURE IN THE WAKE OF STRONG VORT MOVING AWAY
OVER OHIO. THUS MODEST NORTHEAST WINDS WILL LIKELY HOLD TEMPS INTO
THE LOW-MID 60S ALONG THE LAKE MICHIGAN SHORES...WHILE AREAS WELL
INLAND WARM TO AROUND 70 OR THE LOWER 70S FAR WEST UNDER GENERALLY
MOSTLY SUNNY SKIES DURING THE AFTERNOON.
RATZER
//PREV DISCUSSION...
338 AM CDT
MAIN FORECAST CHALLENGES THIS MORNING ARE WITH LAKE EFFECT CLOUD
POTENTIAL NOW THROUGH LATE MORNING TODAY...WITH MOSTLY SUNNY SKIES
THEN EXPECTED FOR THE ENTIRE AREA INTO THE AFTERNOON AS TEMPS RISE
TO THE UPPER 60S AND LOW 70S.
LATEST WATER VAPOR IMAGERY DEPICTING A FAIRLY STRONG PIECE OF MID
LEVEL ENERGY WRAPPING AROUND THE CLOSED UPPER LEVEL SYSTEM ACROSS
THE EASTERN GREAT LAKES REGION THIS MORNING. AS THIS
OCCURS...COLDER AIR WILL CONTINUE TO WORK ITS WAY SOUTHWEST OVER
THE LAKE THIS MORNING AND ACROSS THE CWA THROUGH THE AFTERNOON.
WHAT THIS WILL MEAN FOR TODAY IS SLIGHTLY COOLER HIGH TEMPERATURES
ACROSS THE CWA AS WELL AS THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER TO SPILL INTO AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS AND
NORTHWEST INDIANA. AS WAS EXPECTED...LATEST RAP ANALYSIS SHOWING
DELTA TS FINALLY INCREASING ACROSS THE ENTIRE LENGTH OF THE
LAKE...WITH THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING. ALTHOUGH LATEST SATELLITE IMAGERY SHOWING THIS CLOUD
COVER SOMEWHAT SLOW TO DEVELOP OVER THE NORTHERN PORTIONS OF THE
LAKE...SHOULD BEGIN TO SEE AN INCREASE IN THIS DEVELOPMENT OVER
THE NEXT TWO TO THREE HOURS. FAVORED LOW LEVEL FLOW SHOULD KEEP
MOST OF ANY CLOUD COVER OVER AREAS IN FAR NORTHEAST ILLINOIS...BUT
WITH SOME CLOUD COVER TO STILL POSSIBLY SPILL OVER INTO AREAS IN
FAR NORTHWEST INDIANA. ALTHOUGH THIS CLOUD COVER IS EXPECTED TO
DEVELOP AND MOVE ACROSS AREAS NEAR THE LAKE...IT SHOULDNT BE MORE
THAN PARTLY CLOUDY SKIES WITH SOME BRIEF PERIODS OF PARTLY
SUNNY/CLOUDY CONDITIONS THROUGH THE 15Z TIME FRAME. AFTER THIS
TIME FRAME...CLOUD COVER SHOULD BEGIN TO DIMINISH INTO THE
AFTERNOON AS HIGHER PRESSURE SHIFTS DOWN THE LAKE. AFTER THIS
POINT...SKIES SHOULD BE MOSTLY SUNNY INTO THE AFTERNOON WITH
ANOTHER PLEASANT DAY IN STORE. ALTHOUGH TEMPS TODAY WILL BE
SLIGHTLY COOLER THAN YESTERDAY...I DID RAISE TEMPS A COUPLE OF
DEGREES OVER GUIDANCE WITH TEMPERATURES RISING INTO THE LOW 70S
FOR MOST AREAS IN NORTHERN ILLINOIS...WITH TEMPS SLIGHTLY COOLER
IN THE UPPER 60S IF NOT AROUND 70 MARK FOR AREAS NEAR THE LAKE.
NONETHELESS...A PLEASANT DAY WILL BE IN STORE FOR THE AREA TODAY.
AFTER QUIET CONDITIONS ONCE AGAIN TONIGHT INTO THE EARLY PORTIONS
OF MONDAY...A SOMEWHAT MORE ACTIVE WEATHER APPEARS TO BE ON THE
HORIZON. AS MID AND HIGH LEVEL CLOUD INCREASES FROM THE SOUTH ON
MONDAY...TEMPS SHOULD STILL RISE INTO THE LOW 70S ON MONDAY.
ALTHOUGH AS WAS EXPECTED OVER THE LAST 24 HOURS...MODELS CONTINUE
TO TREND TOWARDS BRINGING CURRENT CLOSED UPPER LEVEL LOW OVER THE
SOUTHERN PLAINS NORTHEAST TOWARDS THE AREA BY LATE MONDAY. MODEL
CONSENSUS SEEMS TO BRING THIS UPPER LEVEL SYSTEM AND SURFACE
REFLECTION UP THROUGH THE TENNESSEE VALLEY LATE MONDAY INTO EARLY
TUESDAY MORNING...AS A SEPARATE MID LEVEL TROUGH APPROACHES FROM
THE NORTHERN PLAINS. ALTHOUGH WITH A LACK OF MOISTURE WITH THIS
NORTHERN STREAM MID LEVEL TROUGH...PRECIP SHOULD BE DIMINISHING AS
IT APPROACHES THE CWA. BEST CHANCES FOR SHOWERS WILL BE FOR AREAS
ACROSS THE SOUTHEAST CWA MONDAY NIGHT. THIS SYSTEM WILL SLOWLY
SPIN ACROSS THE REGION...WITH PRECIP POSSIBLY LINGERING ACROSS
THE SAME AREA TUESDAY INTO TUESDAY NIGHT. CURRENT FORECAST KEEPS
PRECIP CHANCES THROUGH LATE IN THE DAY TUESDAY...BUT ITS
CONCEIVABLE THAT THIS SYSTEM WILL TAKE A SLOWER EASTWARD MOVEMENT.
IF THIS WERE TO OCCUR...PRECIP COULD LINGER INTO THE MIDDLE PART
OF THE WEEK BEFORE EXITING. AFTER WEAK RIDGING AND A SLIGHT
INCREASE IN TEMPS ON WEDNESDAY...ANOTHER MID LEVEL SYSTEM AND
SURFACE REFLECTION/FRONTAL BOUNDARY WILL APPROACH THE CWA WITH
PRECIP CHANCES INCREASING ONCE AGAIN TOWARDS THE END OF THE WORK
WEEK. IT WOULD APPEAR THAT MAINLY SHOWERS SHOULD BE OBSERVED AS
THIS SYSTEM PUSHES THROUGH THE AREA ON THURSDAY...BUT WITH SOME
UNCERTAINTY AS TO THE OVERALL AMOUNT OF MOISTURE/INSTABILITY
PRESENT OUT AHEAD OF IT. IF THE ECMWF WERE TO VERIFY...THEN
PRIMARILY SHOWERS WOULD BE OBSERVED. IN CONTRAST...THE GFS SEEMS
TO BE MORE AGGRESSIVE WITH DEWPOINTS AND IF THIS WERE TO
OCCUR...THEN THUNDERSTORMS COULD BE PRESENT OUT AHEAD OF THIS
SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY ENELY-NELY WINDS TO G15-20KT THROUGH EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...
A BKN MVFR DECK OF LAKE EFFECT CLOUDINESS MOVED ONSHORE THIS
MORNING AND COOL HIGH PRESSURE AS HIGH PRESSURE PUSHED SWD DOWN
LAKE MICHIGAN. LATEST VISIBLE SATELLITE IMAGERY SHOWS A SHARP BACK
EDGE OF THE CLOUD DECK PUSHING INLAND AS THE CLOUD DECK THINS WITH
DEEP LAYER MIXING THROUGH THE LATE MORNING HOURS. EXPECT ANY
REMAINING CLOUD THIS AFTERNOON TO BE FEW TO SCT. THE DEEP LAYER
MIXING IS GENERATING GUSTS TO ARND 20KT WITH AN OCNL HIGHER GUST.
EXPECT THAT THE GUSTINESS SHOULD SUBSIDE WITH SUNSET. AS THE HIGH
PRESSURE CONTINUES TO BUILD SOUTH OVER THE REGION...WINDS WILL
BECOME LIGHT AND VARIABLE OVERNIGHT. UNDER CLEAR SKIES AND LIGHT
WINDS...SOME SHALLOW GROUND FOG MAY FORM IN LOW LYING AREAS...BUT
SHOULD NOT IMPACT ORD/MDW/GYY. THERE IS A CHANCE SOME MIFG COULD
DRIFT OVER RFD/DPA...BUT WILL LEAVE OUT OF THE TAFS FOR NOW AS IT
WOULD LIKELY NOT HAVE AN OPERATIONAL IMPACT.
WINDS SHOULD TURN MORE SELY TOMORROW AS LOW PRESSURE TRACKS NWD
THROUGH THE OHIO VALLEY. THIS WILL BRING INCREASING CI THOUGH THE
DAY TOMORROW...AND COULD BRING INCREASING MID CLOUD AS WELL...BUT
LIKELY NOT UNTIL AFTER THE END OF THE FORECAST PERIOD.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN SUSTAINED WIND SPEED/DIRECTION.
* MODERATE CONFIDENCE IN MAX SPEED AND DURATION OF GUSTS.
* MODERATE TO HIGH CONFIDENCE THAT ANY MIFG THAT FORMS IN THE
REGION WILL NOT IMPACT THE ORD/MDW TERMINALS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...CHC FOR MVFR.
TUESDAY...SMALL CHC FOR MORNING VFR.
WEDNESDAY...VFR.
THURSDAY...CHC OF SHRA AND MVFR.
FRIDAY...WINDY. CHC OF SHRA AND MVFR
SATURDAY...VFR.
MTF
&&
.MARINE...
242 PM...A WEAK RIDGE OF HIGH PRESSURE WILL MOVE SOUTH ACROSS LAKE
MICHIGAN TONIGHT. NORTHEAST WINDS WILL SLOWLY DIMINISH THIS EVENING
AND BEGIN TO TURN SOUTHERLY FROM NORTH TO SOUTH MONDAY MORNING. A
COLD FRONT WILL MOVE ACROSS THE WESTERN LAKES MONDAY INTO MONDAY
EVENING AND THE GRADIENT WILL TIGHTEN SOME AHEAD OF THIS FRONT
WITH SOUTHERLY WINDS PERHAPS AS HIGH AS 10-20 KTS ACROSS THE
NORTHERN PART OF THE LAKE MONDAY AFTERNOON/EVENING. THIS FRONT
WILL MOVE ACROSS NORTHERN LAKE MICHIGAN TUESDAY NIGHT AS IT SLOWS
AND IS THEN ABSORBED AS LOW PRESSURE CURRENTLY OVER LOUISIANA
LIFTS NORTH ACROSS THE OHIO VALLEY ON TUESDAY AND THEN ACROSS THE
SOUTHERN LAKES REGION TUESDAY NIGHT. WINDS WILL TURN NORTHEASTERLY
ACROSS THE ENTIRE LAKE DURING THIS TIME WITH 10-20 KTS LIKELY OVER
THE SOUTHERN HALF OF THE LAKE. THIS LOW WILL WEAKEN AS IT
CONTINUES MOVING NORTH ON WEDNESDAY.
A STRONG COLD FRONT WILL MOVE ACROSS THE NORTHERN AND CENTRAL PLAINS
WEDNESDAY AND WEDNESDAY NIGHT...REACHING THE WESTERN LAKES REGION ON
THURSDAY. THERE STILL REMAINS SOME UNCERTAINTY REGARDING THE TIMING
OF THIS FRONT. IF NEW LOW PRESSURE DEVELOPS ALONG THE FRONT OVER
MINNESOTA AND WISCONSIN...THE FRONT WILL LIKELY SLOW AND NOT REACH
LAKE MICHIGAN UNTIL LATE THURSDAY AFTERNOON OR THURSDAY EVENING.
SHOULD NO NEW LOW PRESSURE DEVELOP...THE FRONT COULD SPEED UP AND
ARRIVE AS EARLY AS THURSDAY MORNING. SOUTHERLY FLOW AHEAD OF THE
FRONT IS EXPECTED AND COULD BECOME STRONGER WITH A SLOWER FRONTAL
PASSAGE. COLDER AIR BEHIND THE FRONT ALONG WITH THE POSSIBILITY OF A
DEEPENING LOW MOVING INTO ONTARIO WILL LIKELY LEAD TO STRONG WINDS
TO 30 KTS...ESPECIALLY ON THE NORTH END OF THE LAKE. GALES ARE ALSO
POSSIBLE DURING THIS TIME PERIOD BUT TOO MUCH UNCERTAINTY TO INCLUDE
JUST YET. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ006-ILZ014 UNTIL 4 AM MONDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002 UNTIL 4 AM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
230 PM CDT SUN SEP 30 2012
.DISCUSSION...
1111 AM CDT
FOR MORNING UPDATE...
ONLY MINOR TWEAKS TO HOURLY SKY COVER GRIDS MADE THIS MORNING...WITH
FORECAST GENERALLY RIGHT ON TRACK.
COLD FRONT WHICH PASSED ACROSS THE AREA LAST EVENING WAS OVER THE
OHIO VALLEY AT MID-MORNING...WITH WEAK HIGH PRESSURE SPREADING
ACROSS THE NORTHERN GREAT LAKES. NORTHEAST SURFACE WINDS WERE
PROVIDING COOLER LOW LEVEL AIR TO THE REGION...WITH A SOME
LAKE-INDUCED STRATOCU MOVING INLAND OFF OF LAKE MICHIGAN INTO
NORTHEAST IL. STRATOCU LAYER IS EXPECTED TO DECREASE IN COVERAGE AS
WE HEAD INTO THE AFTERNOON HOURS...THANKS TO WARMING TEMPS ABOVE THE
BOUNDARY LAYER IN RESPONSE TO LARGE SCALE SUBSIDENCE ASSOCIATED WITH
AFOREMENTIONED HIGH PRESSURE IN THE WAKE OF STRONG VORT MOVING AWAY
OVER OHIO. THUS MODEST NORTHEAST WINDS WILL LIKELY HOLD TEMPS INTO
THE LOW-MID 60S ALONG THE LAKE MICHIGAN SHORES...WHILE AREAS WELL
INLAND WARM TO AROUND 70 OR THE LOWER 70S FAR WEST UNDER GENERALLY
MOSTLY SUNNY SKIES DURING THE AFTERNOON.
RATZER
//PREV DISCUSSION...
338 AM CDT
MAIN FORECAST CHALLENGES THIS MORNING ARE WITH LAKE EFFECT CLOUD
POTENTIAL NOW THROUGH LATE MORNING TODAY...WITH MOSTLY SUNNY SKIES
THEN EXPECTED FOR THE ENTIRE AREA INTO THE AFTERNOON AS TEMPS RISE
TO THE UPPER 60S AND LOW 70S.
LATEST WATER VAPOR IMAGERY DEPICTING A FAIRLY STRONG PIECE OF MID
LEVEL ENERGY WRAPPING AROUND THE CLOSED UPPER LEVEL SYSTEM ACROSS
THE EASTERN GREAT LAKES REGION THIS MORNING. AS THIS
OCCURS...COLDER AIR WILL CONTINUE TO WORK ITS WAY SOUTHWEST OVER
THE LAKE THIS MORNING AND ACROSS THE CWA THROUGH THE AFTERNOON.
WHAT THIS WILL MEAN FOR TODAY IS SLIGHTLY COOLER HIGH TEMPERATURES
ACROSS THE CWA AS WELL AS THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER TO SPILL INTO AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS AND
NORTHWEST INDIANA. AS WAS EXPECTED...LATEST RAP ANALYSIS SHOWING
DELTA TS FINALLY INCREASING ACROSS THE ENTIRE LENGTH OF THE
LAKE...WITH THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING. ALTHOUGH LATEST SATELLITE IMAGERY SHOWING THIS CLOUD
COVER SOMEWHAT SLOW TO DEVELOP OVER THE NORTHERN PORTIONS OF THE
LAKE...SHOULD BEGIN TO SEE AN INCREASE IN THIS DEVELOPMENT OVER
THE NEXT TWO TO THREE HOURS. FAVORED LOW LEVEL FLOW SHOULD KEEP
MOST OF ANY CLOUD COVER OVER AREAS IN FAR NORTHEAST ILLINOIS...BUT
WITH SOME CLOUD COVER TO STILL POSSIBLY SPILL OVER INTO AREAS IN
FAR NORTHWEST INDIANA. ALTHOUGH THIS CLOUD COVER IS EXPECTED TO
DEVELOP AND MOVE ACROSS AREAS NEAR THE LAKE...IT SHOULDNT BE MORE
THAN PARTLY CLOUDY SKIES WITH SOME BRIEF PERIODS OF PARTLY
SUNNY/CLOUDY CONDITIONS THROUGH THE 15Z TIME FRAME. AFTER THIS
TIME FRAME...CLOUD COVER SHOULD BEGIN TO DIMINISH INTO THE
AFTERNOON AS HIGHER PRESSURE SHIFTS DOWN THE LAKE. AFTER THIS
POINT...SKIES SHOULD BE MOSTLY SUNNY INTO THE AFTERNOON WITH
ANOTHER PLEASANT DAY IN STORE. ALTHOUGH TEMPS TODAY WILL BE
SLIGHTLY COOLER THAN YESTERDAY...I DID RAISE TEMPS A COUPLE OF
DEGREES OVER GUIDANCE WITH TEMPERATURES RISING INTO THE LOW 70S
FOR MOST AREAS IN NORTHERN ILLINOIS...WITH TEMPS SLIGHTLY COOLER
IN THE UPPER 60S IF NOT AROUND 70 MARK FOR AREAS NEAR THE LAKE.
NONETHELESS...A PLEASANT DAY WILL BE IN STORE FOR THE AREA TODAY.
AFTER QUIET CONDITIONS ONCE AGAIN TONIGHT INTO THE EARLY PORTIONS
OF MONDAY...A SOMEWHAT MORE ACTIVE WEATHER APPEARS TO BE ON THE
HORIZON. AS MID AND HIGH LEVEL CLOUD INCREASES FROM THE SOUTH ON
MONDAY...TEMPS SHOULD STILL RISE INTO THE LOW 70S ON MONDAY.
ALTHOUGH AS WAS EXPECTED OVER THE LAST 24 HOURS...MODELS CONTINUE
TO TREND TOWARDS BRINGING CURRENT CLOSED UPPER LEVEL LOW OVER THE
SOUTHERN PLAINS NORTHEAST TOWARDS THE AREA BY LATE MONDAY. MODEL
CONSENSUS SEEMS TO BRING THIS UPPER LEVEL SYSTEM AND SURFACE
REFLECTION UP THROUGH THE TENNESSEE VALLEY LATE MONDAY INTO EARLY
TUESDAY MORNING...AS A SEPARATE MID LEVEL TROUGH APPROACHES FROM
THE NORTHERN PLAINS. ALTHOUGH WITH A LACK OF MOISTURE WITH THIS
NORTHERN STREAM MID LEVEL TROUGH...PRECIP SHOULD BE DIMINISHING AS
IT APPROACHES THE CWA. BEST CHANCES FOR SHOWERS WILL BE FOR AREAS
ACROSS THE SOUTHEAST CWA MONDAY NIGHT. THIS SYSTEM WILL SLOWLY
SPIN ACROSS THE REGION...WITH PRECIP POSSIBLY LINGERING ACROSS
THE SAME AREA TUESDAY INTO TUESDAY NIGHT. CURRENT FORECAST KEEPS
PRECIP CHANCES THROUGH LATE IN THE DAY TUESDAY...BUT ITS
CONCEIVABLE THAT THIS SYSTEM WILL TAKE A SLOWER EASTWARD MOVEMENT.
IF THIS WERE TO OCCUR...PRECIP COULD LINGER INTO THE MIDDLE PART
OF THE WEEK BEFORE EXITING. AFTER WEAK RIDGING AND A SLIGHT
INCREASE IN TEMPS ON WEDNESDAY...ANOTHER MID LEVEL SYSTEM AND
SURFACE REFLECTION/FRONTAL BOUNDARY WILL APPROACH THE CWA WITH
PRECIP CHANCES INCREASING ONCE AGAIN TOWARDS THE END OF THE WORK
WEEK. IT WOULD APPEAR THAT MAINLY SHOWERS SHOULD BE OBSERVED AS
THIS SYSTEM PUSHES THROUGH THE AREA ON THURSDAY...BUT WITH SOME
UNCERTAINTY AS TO THE OVERALL AMOUNT OF MOISTURE/INSTABILITY
PRESENT OUT AHEAD OF IT. IF THE ECMWF WERE TO VERIFY...THEN
PRIMARILY SHOWERS WOULD BE OBSERVED. IN CONTRAST...THE GFS SEEMS
TO BE MORE AGGRESSIVE WITH DEWPOINTS AND IF THIS WERE TO
OCCUR...THEN THUNDERSTORMS COULD BE PRESENT OUT AHEAD OF THIS
SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY ENELY-NELY WINDS TO G15-20KT THROUGH EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...
A BKN MVFR DECK OF LAKE EFFECT CLOUDINESS MOVED ONSHORE THIS
MORNING AND COOL HIGH PRESSURE AS HIGH PRESSURE PUSHED SWD DOWN
LAKE MICHIGAN. LATEST VISIBLE SATELLITE IMAGERY SHOWS A SHARP BACK
EDGE OF THE CLOUD DECK PUSHING INLAND AS THE CLOUD DECK THINS WITH
DEEP LAYER MIXING THROUGH THE LATE MORNING HOURS. EXPECT ANY
REMAINING CLOUD THIS AFTERNOON TO BE FEW TO SCT. THE DEEP LAYER
MIXING IS GENERATING GUSTS TO ARND 20KT WITH AN OCNL HIGHER GUST.
EXPECT THAT THE GUSTINESS SHOULD SUBSIDE WITH SUNSET. AS THE HIGH
PRESSURE CONTINUES TO BUILD SOUTH OVER THE REGION...WINDS WILL
BECOME LIGHT AND VARIABLE OVERNIGHT. UNDER CLEAR SKIES AND LIGHT
WINDS...SOME SHALLOW GROUND FOG MAY FORM IN LOW LYING AREAS...BUT
SHOULD NOT IMPACT ORD/MDW/GYY. THERE IS A CHANCE SOME MIFG COULD
DRIFT OVER RFD/DPA...BUT WILL LEAVE OUT OF THE TAFS FOR NOW AS IT
WOULD LIKELY NOT HAVE AN OPERATIONAL IMPACT.
WINDS SHOULD TURN MORE SELY TOMORROW AS LOW PRESSURE TRACKS NWD
THROUGH THE OHIO VALLEY. THIS WILL BRING INCREASING CI THOUGH THE
DAY TOMORROW...AND COULD BRING INCREASING MID CLOUD AS WELL...BUT
LIKELY NOT UNTIL AFTER THE END OF THE FORECAST PERIOD.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN SUSTAINED WIND SPEED/DIRECTION.
* MODERATE CONFIDENCE IN MAX SPEED AND DURATION OF GUSTS.
* MODERATE TO HIGH CONFIDENCE THAT ANY MIFG THAT FORMS IN THE
REGION WILL NOT IMPACT THE ORD/MDW TERMINALS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...CHC FOR MVFR.
TUESDAY...SMALL CHC FOR MORNING VFR.
WEDNESDAY...VFR.
THURSDAY...CHC OF SHRA AND MVFR.
FRIDAY...WINDY. CHC OF SHRA AND MVFR
SATURDAY...VFR.
MTF
&&
.MARINE...
224 AM CDT
BEHIND A COOL FRONT WHICH PASSED LATE ON SATURDAY...NORTHEAST FLOW
WILL CONTINUE ACROSS THE LAKE TODAY. THIS WILL BE DIRECTED INTO THE
NEARSHORE AREAS OF ILLINOIS AND INDIANA...FAVORING HIGH WAVES INTO
THE AFTERNOON AND EVENING. HIGH PRESSURE WILL SLIDE SOUTHWARD OVER
THE LAKE TONIGHT INTO EARLY MONDAY EASING WINDS. A WEAK COOL FRONT
WILL PASS FROM WEST TO EAST OVER THE LAKE ON MONDAY NIGHT...OFFERING
A WIND SHIFT BUT NO REAL INCREASE IN SPEED. THAT IS IN PART BECAUSE
LOW PRESSURE WILL BE MOVING NORTHEASTWARD FROM THE LOWER OHIO VALLEY
TO HUDSON BAY TUESDAY INTO WEDNESDAY SLOWING THE AFOREMENTIONED
BOUNDARY. A POTENTIALLY ACTIVE END OF THE WEEK OVER THE WESTERN
GREAT LAKES MAY BE IN STORE AS SEVERAL FORECAST MODELS INDICATE A
STRONG LOW PRESSURE SOMEWHERE IN THE UPPER MIDWEST/GREAT LAKES
REGION...WITH STRONG THERMAL ADVECTION CONDUCIVE FOR GUSTY WINDS
AHEAD AND BEHIND OF THE LOW PRESSURE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ006-ILZ014 UNTIL 4 AM MONDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002 UNTIL 4 AM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1223 PM CDT SUN SEP 30 2012
.DISCUSSION...
1111 AM CDT
FOR MORNING UPDATE...
ONLY MINOR TWEAKS TO HOURLY SKY COVER GRIDS MADE THIS MORNING...WITH
FORECAST GENERALLY RIGHT ON TRACK.
COLD FRONT WHICH PASSED ACROSS THE AREA LAST EVENING WAS OVER THE
OHIO VALLEY AT MID-MORNING...WITH WEAK HIGH PRESSURE SPREADING
ACROSS THE NORTHERN GREAT LAKES. NORTHEAST SURFACE WINDS WERE
PROVIDING COOLER LOW LEVEL AIR TO THE REGION...WITH A SOME
LAKE-INDUCED STRATOCU MOVING INLAND OFF OF LAKE MICHIGAN INTO
NORTHEAST IL. STRATOCU LAYER IS EXPECTED TO DECREASE IN COVERAGE AS
WE HEAD INTO THE AFTERNOON HOURS...THANKS TO WARMING TEMPS ABOVE THE
BOUNDARY LAYER IN RESPONSE TO LARGE SCALE SUBSIDENCE ASSOCIATED WITH
AFOREMENTIONED HIGH PRESSURE IN THE WAKE OF STRONG VORT MOVING AWAY
OVER OHIO. THUS MODEST NORTHEAST WINDS WILL LIKELY HOLD TEMPS INTO
THE LOW-MID 60S ALONG THE LAKE MICHIGAN SHORES...WHILE AREAS WELL
INLAND WARM TO AROUND 70 OR THE LOWER 70S FAR WEST UNDER GENERALLY
MOSTLY SUNNY SKIES DURING THE AFTERNOON.
RATZER
//PREV DISCUSSION...
338 AM CDT
MAIN FORECAST CHALLENGES THIS MORNING ARE WITH LAKE EFFECT CLOUD
POTENTIAL NOW THROUGH LATE MORNING TODAY...WITH MOSTLY SUNNY SKIES
THEN EXPECTED FOR THE ENTIRE AREA INTO THE AFTERNOON AS TEMPS RISE
TO THE UPPER 60S AND LOW 70S.
LATEST WATER VAPOR IMAGERY DEPICTING A FAIRLY STRONG PIECE OF MID
LEVEL ENERGY WRAPPING AROUND THE CLOSED UPPER LEVEL SYSTEM ACROSS
THE EASTERN GREAT LAKES REGION THIS MORNING. AS THIS
OCCURS...COLDER AIR WILL CONTINUE TO WORK ITS WAY SOUTHWEST OVER
THE LAKE THIS MORNING AND ACROSS THE CWA THROUGH THE AFTERNOON.
WHAT THIS WILL MEAN FOR TODAY IS SLIGHTLY COOLER HIGH TEMPERATURES
ACROSS THE CWA AS WELL AS THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER TO SPILL INTO AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS AND
NORTHWEST INDIANA. AS WAS EXPECTED...LATEST RAP ANALYSIS SHOWING
DELTA TS FINALLY INCREASING ACROSS THE ENTIRE LENGTH OF THE
LAKE...WITH THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING. ALTHOUGH LATEST SATELLITE IMAGERY SHOWING THIS CLOUD
COVER SOMEWHAT SLOW TO DEVELOP OVER THE NORTHERN PORTIONS OF THE
LAKE...SHOULD BEGIN TO SEE AN INCREASE IN THIS DEVELOPMENT OVER
THE NEXT TWO TO THREE HOURS. FAVORED LOW LEVEL FLOW SHOULD KEEP
MOST OF ANY CLOUD COVER OVER AREAS IN FAR NORTHEAST ILLINOIS...BUT
WITH SOME CLOUD COVER TO STILL POSSIBLY SPILL OVER INTO AREAS IN
FAR NORTHWEST INDIANA. ALTHOUGH THIS CLOUD COVER IS EXPECTED TO
DEVELOP AND MOVE ACROSS AREAS NEAR THE LAKE...IT SHOULDNT BE MORE
THAN PARTLY CLOUDY SKIES WITH SOME BRIEF PERIODS OF PARTLY
SUNNY/CLOUDY CONDITIONS THROUGH THE 15Z TIME FRAME. AFTER THIS
TIME FRAME...CLOUD COVER SHOULD BEGIN TO DIMINISH INTO THE
AFTERNOON AS HIGHER PRESSURE SHIFTS DOWN THE LAKE. AFTER THIS
POINT...SKIES SHOULD BE MOSTLY SUNNY INTO THE AFTERNOON WITH
ANOTHER PLEASANT DAY IN STORE. ALTHOUGH TEMPS TODAY WILL BE
SLIGHTLY COOLER THAN YESTERDAY...I DID RAISE TEMPS A COUPLE OF
DEGREES OVER GUIDANCE WITH TEMPERATURES RISING INTO THE LOW 70S
FOR MOST AREAS IN NORTHERN ILLINOIS...WITH TEMPS SLIGHTLY COOLER
IN THE UPPER 60S IF NOT AROUND 70 MARK FOR AREAS NEAR THE LAKE.
NONETHELESS...A PLEASANT DAY WILL BE IN STORE FOR THE AREA TODAY.
AFTER QUIET CONDITIONS ONCE AGAIN TONIGHT INTO THE EARLY PORTIONS
OF MONDAY...A SOMEWHAT MORE ACTIVE WEATHER APPEARS TO BE ON THE
HORIZON. AS MID AND HIGH LEVEL CLOUD INCREASES FROM THE SOUTH ON
MONDAY...TEMPS SHOULD STILL RISE INTO THE LOW 70S ON MONDAY.
ALTHOUGH AS WAS EXPECTED OVER THE LAST 24 HOURS...MODELS CONTINUE
TO TREND TOWARDS BRINGING CURRENT CLOSED UPPER LEVEL LOW OVER THE
SOUTHERN PLAINS NORTHEAST TOWARDS THE AREA BY LATE MONDAY. MODEL
CONSENSUS SEEMS TO BRING THIS UPPER LEVEL SYSTEM AND SURFACE
REFLECTION UP THROUGH THE TENNESSEE VALLEY LATE MONDAY INTO EARLY
TUESDAY MORNING...AS A SEPARATE MID LEVEL TROUGH APPROACHES FROM
THE NORTHERN PLAINS. ALTHOUGH WITH A LACK OF MOISTURE WITH THIS
NORTHERN STREAM MID LEVEL TROUGH...PRECIP SHOULD BE DIMINISHING AS
IT APPROACHES THE CWA. BEST CHANCES FOR SHOWERS WILL BE FOR AREAS
ACROSS THE SOUTHEAST CWA MONDAY NIGHT. THIS SYSTEM WILL SLOWLY
SPIN ACROSS THE REGION...WITH PRECIP POSSIBLY LINGERING ACROSS
THE SAME AREA TUESDAY INTO TUESDAY NIGHT. CURRENT FORECAST KEEPS
PRECIP CHANCES THROUGH LATE IN THE DAY TUESDAY...BUT ITS
CONCEIVABLE THAT THIS SYSTEM WILL TAKE A SLOWER EASTWARD MOVEMENT.
IF THIS WERE TO OCCUR...PRECIP COULD LINGER INTO THE MIDDLE PART
OF THE WEEK BEFORE EXITING. AFTER WEAK RIDGING AND A SLIGHT
INCREASE IN TEMPS ON WEDNESDAY...ANOTHER MID LEVEL SYSTEM AND
SURFACE REFLECTION/FRONTAL BOUNDARY WILL APPROACH THE CWA WITH
PRECIP CHANCES INCREASING ONCE AGAIN TOWARDS THE END OF THE WORK
WEEK. IT WOULD APPEAR THAT MAINLY SHOWERS SHOULD BE OBSERVED AS
THIS SYSTEM PUSHES THROUGH THE AREA ON THURSDAY...BUT WITH SOME
UNCERTAINTY AS TO THE OVERALL AMOUNT OF MOISTURE/INSTABILITY
PRESENT OUT AHEAD OF IT. IF THE ECMWF WERE TO VERIFY...THEN
PRIMARILY SHOWERS WOULD BE OBSERVED. IN CONTRAST...THE GFS SEEMS
TO BE MORE AGGRESSIVE WITH DEWPOINTS AND IF THIS WERE TO
OCCUR...THEN THUNDERSTORMS COULD BE PRESENT OUT AHEAD OF THIS
SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY ENELY-NELY WINDS TO G15-20KT THROUGH EARLY EVENING.
* SCT LAKE EFFECT CLOUDINESS THROUGH THE AFTERNOON.
KREIN
//DISCUSSION...UPDATED 18Z...
A BKN MVFR DECK OF LAKE EFFECT CLOUDINESS MOVED ONSHORE THIS
MORNING AND COOL HIGH PRESSURE AS HIGH PRESSURE PUSHED SWD DOWN
LAKE MICHIGAN. LATEST VISIBLE SATELLITE IMAGERY SHOWS A SHARP BACK
EDGE OF THE CLOUD DECK PUSHING INLAND AS THE CLOUD DECK THINS WITH
DEEP LAYER MIXING THROUGH THE LATE MORNING HOURS. EXPECT ANY
REMAINING CLOUD THIS AFTERNOON TO BE FEW TO SCT. THE DEEP LAYER
MIXING IS GENERATING GUSTS TO ARND 20KT WITH AN OCNL HIGHER GUST.
EXPECT THAT THE GUSTINESS SHOULD SUBSIDE WITH SUNSET. AS THE HIGH
PRESSURE CONTINUES TO BUILD SOUTH OVER THE REGION...WINDS WILL
BECOME LIGHT AND VARIABLE OVERNIGHT. UNDER CLEAR SKIES AND LIGHT
WINDS...SOME SHALLOW GROUND FOG MAY FORM IN LOW LYING AREAS...BUT
SHOULD NOT IMPACT ORD/MDW/GYY. THERE IS A CHANCE SOME MIFG COULD
DRIFT OVER RFD/DPA...BUT WILL LEAVE OUT OF THE TAFS FOR NOW AS IT
WOULD LIKELY NOT HAVE AN OPERATIONAL IMPACT.
WINDS SHOULD TURN MORE SELY TOMORROW AS LOW PRESSURE TRACKS NWD
THROUGH THE OHIO VALLEY. THIS WILL BRING INCREASING CI THOUGH THE
DAY TOMORROW...AND COULD BRING INCREASING MID CLOUD AS WELL...BUT
LIKELY NOT UNTIL AFTER THE END OF THE FORECAST PERIOD.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN SUSTAINED WIND SPEED/DIRECTION.
* MODERATE CONFIDENCE IN MAX SPEED AND DURATION OF GUSTS.
* MODERATE TO HIGH CONFIDENCE THAT ANY MIFG THAT FORMS IN THE
REGION WILL NOT IMPACT THE ORD/MDW TERMINALS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...CHC FOR MVFR.
TUESDAY...SMALL CHC FOR MORNING VFR.
WEDNESDAY...VFR.
THURSDAY...CHC OF SHRA AND MVFR.
FRIDAY...WINDY. CHC OF SHRA AND MVFR
SATURDAY...VFR.
MTF
&&
.MARINE...
224 AM CDT
BEHIND A COOL FRONT WHICH PASSED LATE ON SATURDAY...NORTHEAST FLOW
WILL CONTINUE ACROSS THE LAKE TODAY. THIS WILL BE DIRECTED INTO THE
NEARSHORE AREAS OF ILLINOIS AND INDIANA...FAVORING HIGH WAVES INTO
THE AFTERNOON AND EVENING. HIGH PRESSURE WILL SLIDE SOUTHWARD OVER
THE LAKE TONIGHT INTO EARLY MONDAY EASING WINDS. A WEAK COOL FRONT
WILL PASS FROM WEST TO EAST OVER THE LAKE ON MONDAY NIGHT...OFFERING
A WIND SHIFT BUT NO REAL INCREASE IN SPEED. THAT IS IN PART BECAUSE
LOW PRESSURE WILL BE MOVING NORTHEASTWARD FROM THE LOWER OHIO VALLEY
TO HUDSON BAY TUESDAY INTO WEDNESDAY SLOWING THE AFOREMENTIONED
BOUNDARY. A POTENTIALLY ACTIVE END OF THE WEEK OVER THE WESTERN
GREAT LAKES MAY BE IN STORE AS SEVERAL FORECAST MODELS INDICATE A
STRONG LOW PRESSURE SOMEWHERE IN THE UPPER MIDWEST/GREAT LAKES
REGION...WITH STRONG THERMAL ADVECTION CONDUCIVE FOR GUSTY WINDS
AHEAD AND BEHIND OF THE LOW PRESSURE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ006-ILZ014 UNTIL 4 AM MONDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002 UNTIL 4 AM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1118 AM CDT SUN SEP 30 2012
.DISCUSSION...
1111 AM CDT
FOR MORNING UPDATE...
ONLY MINOR TWEAKS TO HOURLY SKY COVER GRIDS MADE THIS MORNING...WITH
FORECAST GENERALLY RIGHT ON TRACK.
COLD FRONT WHICH PASSED ACROSS THE AREA LAST EVENING WAS OVER THE
OHIO VALLEY AT MID-MORNING...WITH WEAK HIGH PRESSURE SPREADING
ACROSS THE NORTHERN GREAT LAKES. NORTHEAST SURFACE WINDS WERE
PROVIDING COOLER LOW LEVEL AIR TO THE REGION...WITH A SOME
LAKE-INDUCED STRATOCU MOVING INLAND OFF OF LAKE MICHIGAN INTO
NORTHEAST IL. STRATOCU LAYER IS EXPECTED TO DECREASE IN COVERAGE AS
WE HEAD INTO THE AFTERNOON HOURS...THANKS TO WARMING TEMPS ABOVE THE
BOUNDARY LAYER IN RESPONSE TO LARGE SCALE SUBSIDENCE ASSOCIATED WITH
AFOREMENTIONED HIGH PRESSURE IN THE WAKE OF STRONG VORT MOVING AWAY
OVER OHIO. THUS MODEST NORTHEAST WINDS WILL LIKELY HOLD TEMPS INTO
THE LOW-MID 60S ALONG THE LAKE MICHIGAN SHORES...WHILE AREAS WELL
INLAND WARM TO AROUND 70 OR THE LOWER 70S FAR WEST UNDER GENERALLY
MOSTLY SUNNY SKIES DURING THE AFTERNOON.
RATZER
//PREV DISCUSSION...
338 AM CDT
MAIN FORECAST CHALLENGES THIS MORNING ARE WITH LAKE EFFECT CLOUD
POTENTIAL NOW THROUGH LATE MORNING TODAY...WITH MOSTLY SUNNY SKIES
THEN EXPECTED FOR THE ENTIRE AREA INTO THE AFTERNOON AS TEMPS RISE
TO THE UPPER 60S AND LOW 70S.
LATEST WATER VAPOR IMAGERY DEPICTING A FAIRLY STRONG PIECE OF MID
LEVEL ENERGY WRAPPING AROUND THE CLOSED UPPER LEVEL SYSTEM ACROSS
THE EASTERN GREAT LAKES REGION THIS MORNING. AS THIS
OCCURS...COLDER AIR WILL CONTINUE TO WORK ITS WAY SOUTHWEST OVER
THE LAKE THIS MORNING AND ACROSS THE CWA THROUGH THE AFTERNOON.
WHAT THIS WILL MEAN FOR TODAY IS SLIGHTLY COOLER HIGH TEMPERATURES
ACROSS THE CWA AS WELL AS THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER TO SPILL INTO AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS AND
NORTHWEST INDIANA. AS WAS EXPECTED...LATEST RAP ANALYSIS SHOWING
DELTA TS FINALLY INCREASING ACROSS THE ENTIRE LENGTH OF THE
LAKE...WITH THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING. ALTHOUGH LATEST SATELLITE IMAGERY SHOWING THIS CLOUD
COVER SOMEWHAT SLOW TO DEVELOP OVER THE NORTHERN PORTIONS OF THE
LAKE...SHOULD BEGIN TO SEE AN INCREASE IN THIS DEVELOPMENT OVER
THE NEXT TWO TO THREE HOURS. FAVORED LOW LEVEL FLOW SHOULD KEEP
MOST OF ANY CLOUD COVER OVER AREAS IN FAR NORTHEAST ILLINOIS...BUT
WITH SOME CLOUD COVER TO STILL POSSIBLY SPILL OVER INTO AREAS IN
FAR NORTHWEST INDIANA. ALTHOUGH THIS CLOUD COVER IS EXPECTED TO
DEVELOP AND MOVE ACROSS AREAS NEAR THE LAKE...IT SHOULDNT BE MORE
THAN PARTLY CLOUDY SKIES WITH SOME BRIEF PERIODS OF PARTLY
SUNNY/CLOUDY CONDITIONS THROUGH THE 15Z TIME FRAME. AFTER THIS
TIME FRAME...CLOUD COVER SHOULD BEGIN TO DIMINISH INTO THE
AFTERNOON AS HIGHER PRESSURE SHIFTS DOWN THE LAKE. AFTER THIS
POINT...SKIES SHOULD BE MOSTLY SUNNY INTO THE AFTERNOON WITH
ANOTHER PLEASANT DAY IN STORE. ALTHOUGH TEMPS TODAY WILL BE
SLIGHTLY COOLER THAN YESTERDAY...I DID RAISE TEMPS A COUPLE OF
DEGREES OVER GUIDANCE WITH TEMPERATURES RISING INTO THE LOW 70S
FOR MOST AREAS IN NORTHERN ILLINOIS...WITH TEMPS SLIGHTLY COOLER
IN THE UPPER 60S IF NOT AROUND 70 MARK FOR AREAS NEAR THE LAKE.
NONETHELESS...A PLEASANT DAY WILL BE IN STORE FOR THE AREA TODAY.
AFTER QUIET CONDITIONS ONCE AGAIN TONIGHT INTO THE EARLY PORTIONS
OF MONDAY...A SOMEWHAT MORE ACTIVE WEATHER APPEARS TO BE ON THE
HORIZON. AS MID AND HIGH LEVEL CLOUD INCREASES FROM THE SOUTH ON
MONDAY...TEMPS SHOULD STILL RISE INTO THE LOW 70S ON MONDAY.
ALTHOUGH AS WAS EXPECTED OVER THE LAST 24 HOURS...MODELS CONTINUE
TO TREND TOWARDS BRINGING CURRENT CLOSED UPPER LEVEL LOW OVER THE
SOUTHERN PLAINS NORTHEAST TOWARDS THE AREA BY LATE MONDAY. MODEL
CONSENSUS SEEMS TO BRING THIS UPPER LEVEL SYSTEM AND SURFACE
REFLECTION UP THROUGH THE TENNESSEE VALLEY LATE MONDAY INTO EARLY
TUESDAY MORNING...AS A SEPARATE MID LEVEL TROUGH APPROACHES FROM
THE NORTHERN PLAINS. ALTHOUGH WITH A LACK OF MOISTURE WITH THIS
NORTHERN STREAM MID LEVEL TROUGH...PRECIP SHOULD BE DIMINISHING AS
IT APPROACHES THE CWA. BEST CHANCES FOR SHOWERS WILL BE FOR AREAS
ACROSS THE SOUTHEAST CWA MONDAY NIGHT. THIS SYSTEM WILL SLOWLY
SPIN ACROSS THE REGION...WITH PRECIP POSSIBLY LINGERING ACROSS
THE SAME AREA TUESDAY INTO TUESDAY NIGHT. CURRENT FORECAST KEEPS
PRECIP CHANCES THROUGH LATE IN THE DAY TUESDAY...BUT ITS
CONCEIVABLE THAT THIS SYSTEM WILL TAKE A SLOWER EASTWARD MOVEMENT.
IF THIS WERE TO OCCUR...PRECIP COULD LINGER INTO THE MIDDLE PART
OF THE WEEK BEFORE EXITING. AFTER WEAK RIDGING AND A SLIGHT
INCREASE IN TEMPS ON WEDNESDAY...ANOTHER MID LEVEL SYSTEM AND
SURFACE REFLECTION/FRONTAL BOUNDARY WILL APPROACH THE CWA WITH
PRECIP CHANCES INCREASING ONCE AGAIN TOWARDS THE END OF THE WORK
WEEK. IT WOULD APPEAR THAT MAINLY SHOWERS SHOULD BE OBSERVED AS
THIS SYSTEM PUSHES THROUGH THE AREA ON THURSDAY...BUT WITH SOME
UNCERTAINTY AS TO THE OVERALL AMOUNT OF MOISTURE/INSTABILITY
PRESENT OUT AHEAD OF IT. IF THE ECMWF WERE TO VERIFY...THEN
PRIMARILY SHOWERS WOULD BE OBSERVED. IN CONTRAST...THE GFS SEEMS
TO BE MORE AGGRESSIVE WITH DEWPOINTS AND IF THIS WERE TO
OCCUR...THEN THUNDERSTORMS COULD BE PRESENT OUT AHEAD OF THIS
SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE EFFECT MVFR CIGS ENDING BY 18Z. A SHARP BACK EDGE TO THE
BKN DECK OBSERVED ON SATELLITE IMAGERY.
* GUSTY NORTHEAST WINDS TO G15-18KT THROUGH EARLY EVENING.
* SMALL CHANCE FOR MVFR CIGS TONIGHT AND EARLY MONDAY MORNING.
KREIN
//DISCUSSION...UPDATED 12Z...
THE TERMINALS LIE BETWEEEN A COLD FRONT TO THE SOUTH WHICH PASSED
LATE YESTERDAY AND HIGH PRESSURE ACROSS ONTARIO AND QUEBEC. THE
GRADIENT BETWEEN THESE FEATURES WILL CONTINUE TO FAVOR A NORTHEAST
SYNOPTIC WIND. INITIALLY...THROUGH 14Z...A SLIGHTLY MORE NNW WIND
WILL BE SEEN ACROSS NORTHEAST IL DUE TO A REMNANT LAND BREEZE FROM
THE NIGHT. THIS IS AIDING CONVERGENCE INTO NORTHEAST IL THAT
SHOULD HELP TO FOCUS DEVELOPING CLOUDS OVER THE LAKE INTO
NORTHEAST IL BY MID MORNING...AND LIKELY TOWARD GYY AS WELL. THESE
LAKE ENHANCED CLOUDS ARE PRESENTLY FAVORED TO BE AT OR ABOVE 2000
FT BY THE TIME THEY ARRIVE AT THE TERMINALS...BUT AT ONSET SOME
COULD BE BELOW 2000 FT. THAT SHOULD BE BRIEF IF THAT OCCURS.
CLOUDS SHOULD GRADUALLY BECOME MORE SCATTERED THROUGH THE
AFTERNOON AS THE COLD AIR ADVECTION COMPONENT OVER THE WATER
WEAKENS. THE HIGH PRESSURE WILL SETTLE SOUTHWARD OVER THE AREA
THIS EVENING...WITH RETURN FLOW DEVELOPING ON MONDAY.
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN BROKEN CLOUDS BETWEEN 2000 AND 3500 FT.
MEDIUM CONFIDENCE IN TIMING. LOW CONFIDENCE IN ANY CIGS BELOW
2000 FT.
* HIGH CONFIDENCE IN WIND DIRECTIONAL TRENDS. MEDIUM CONFIDENCE
IN MAXIMUM GUST SPEED.
* LOW CONFIDENCE IN ANY RETURNING BROKEN CIGS TONIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...CHC FOR MVFR.
TUESDAY...SMALL CHC FOR MORNING VFR.
WEDNESDAY...VFR.
THURSDAY...CHC OF SHRA AND MVFR.
FRIDAY...WINDY. CHC OF SHRA AND MVFR
SATURDAY...VFR.
MTF
&&
.MARINE...
224 AM CDT
BEHIND A COOL FRONT WHICH PASSED LATE ON SATURDAY...NORTHEAST FLOW
WILL CONTINUE ACROSS THE LAKE TODAY. THIS WILL BE DIRECTED INTO THE
NEARSHORE AREAS OF ILLINOIS AND INDIANA...FAVORING HIGH WAVES INTO
THE AFTERNOON AND EVENING. HIGH PRESSURE WILL SLIDE SOUTHWARD OVER
THE LAKE TONIGHT INTO EARLY MONDAY EASING WINDS. A WEAK COOL FRONT
WILL PASS FROM WEST TO EAST OVER THE LAKE ON MONDAY NIGHT...OFFERING
A WIND SHIFT BUT NO REAL INCREASE IN SPEED. THAT IS IN PART BECAUSE
LOW PRESSURE WILL BE MOVING NORTHEASTWARD FROM THE LOWER OHIO VALLEY
TO HUDSON BAY TUESDAY INTO WEDNESDAY SLOWING THE AFOREMENTIONED
BOUNDARY. A POTENTIALLY ACTIVE END OF THE WEEK OVER THE WESTERN
GREAT LAKES MAY BE IN STORE AS SEVERAL FORECAST MODELS INDICATE A
STRONG LOW PRESSURE SOMEWHERE IN THE UPPER MIDWEST/GREAT LAKES
REGION...WITH STRONG THERMAL ADVECTION CONDUCIVE FOR GUSTY WINDS
AHEAD AND BEHIND OF THE LOW PRESSURE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ006-ILZ014 UNTIL 4 AM MONDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002 UNTIL 4 AM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1112 AM CDT SUN SEP 30 2012
.DISCUSSION...
1111 AM CDT
FOR MORNING UPDATE...
ONLY MINOR TWEAKS TO HOURLY SKY COVER GRIDS MADE THIS MORNING...WITH
FORECAST GENERALLY RIGHT ON TRACK.
COLD FRONT WHICH PASSED ACROSS THE AREA LAST EVENING WAS OVER THE
OHIO VALLEY AT MID-MORNING...WITH WEAK HIGH PRESSURE SPREADING
ACROSS THE NORTHERN GREAT LAKES. NORTHEAST SURFACE WINDS WERE
PROVIDING COOLER LOW LEVEL AIR TO THE REGION...WITH A SOME
LAKE-INDUCED STRATOCU MOVING INLAND OFF OF LAKE MICHIGAN INTO
NORTHEAST IL. STRATOCU LAYER IS EXPECTED TO DECREASE IN COVERAGE AS
WE HEAD INTO THE AFTERNOON HOURS...THANKS TO WARMING TEMPS ABOVE THE
BOUNDARY LAYER IN RESPONSE TO LARGE SCALE SUBSIDENCE ASSOCIATED WITH
AFOREMENTIONED HIGH PRESSURE IN THE WAKE OF STRONG VORT MOVING AWAY
OVER OHIO. THUS MODEST NORTHEAST WINDS WILL LIKELY HOLD TEMPS INTO
THE LOW-MID 60S ALONG THE LAKE MICHIGAN SHORES...WHILE AREAS WELL
INLAND WARM TO AROUND 70 OR THE LOWER 70S FAR WEST UNDER GENERALLY
MOSTLY SUNNY SKIES DURING THE AFTERNOON.
RATZER
&&
.PREV DISCUSSION...
338 AM CDT
MAIN FORECAST CHALLENGES THIS MORNING ARE WITH LAKE EFFECT CLOUD
POTENTIAL NOW THROUGH LATE MORNING TODAY...WITH MOSTLY SUNNY SKIES
THEN EXPECTED FOR THE ENTIRE AREA INTO THE AFTERNOON AS TEMPS RISE
TO THE UPPER 60S AND LOW 70S.
LATEST WATER VAPOR IMAGERY DEPICTING A FAIRLY STRONG PIECE OF MID
LEVEL ENERGY WRAPPING AROUND THE CLOSED UPPER LEVEL SYSTEM ACROSS
THE EASTERN GREAT LAKES REGION THIS MORNING. AS THIS
OCCURS...COLDER AIR WILL CONTINUE TO WORK ITS WAY SOUTHWEST OVER
THE LAKE THIS MORNING AND ACROSS THE CWA THROUGH THE AFTERNOON.
WHAT THIS WILL MEAN FOR TODAY IS SLIGHTLY COOLER HIGH TEMPERATURES
ACROSS THE CWA AS WELL AS THE POTENTIAL FOR SOME LAKE EFFECT CLOUD
COVER TO SPILL INTO AREAS NEAR THE LAKE IN NORTHEAST ILLINOIS AND
NORTHWEST INDIANA. AS WAS EXPECTED...LATEST RAP ANALYSIS SHOWING
DELTA TS FINALLY INCREASING ACROSS THE ENTIRE LENGTH OF THE
LAKE...WITH THIS TREND TO CONTINUE THROUGH THE REMAINDER OF THE
MORNING. ALTHOUGH LATEST SATELLITE IMAGERY SHOWING THIS CLOUD
COVER SOMEWHAT SLOW TO DEVELOP OVER THE NORTHERN PORTIONS OF THE
LAKE...SHOULD BEGIN TO SEE AN INCREASE IN THIS DEVELOPMENT OVER
THE NEXT TWO TO THREE HOURS. FAVORED LOW LEVEL FLOW SHOULD KEEP
MOST OF ANY CLOUD COVER OVER AREAS IN FAR NORTHEAST ILLINOIS...BUT
WITH SOME CLOUD COVER TO STILL POSSIBLY SPILL OVER INTO AREAS IN
FAR NORTHWEST INDIANA. ALTHOUGH THIS CLOUD COVER IS EXPECTED TO
DEVELOP AND MOVE ACROSS AREAS NEAR THE LAKE...IT SHOULDNT BE MORE
THAN PARTLY CLOUDY SKIES WITH SOME BRIEF PERIODS OF PARTLY
SUNNY/CLOUDY CONDITIONS THROUGH THE 15Z TIME FRAME. AFTER THIS
TIME FRAME...CLOUD COVER SHOULD BEGIN TO DIMINISH INTO THE
AFTERNOON AS HIGHER PRESSURE SHIFTS DOWN THE LAKE. AFTER THIS
POINT...SKIES SHOULD BE MOSTLY SUNNY INTO THE AFTERNOON WITH
ANOTHER PLEASANT DAY IN STORE. ALTHOUGH TEMPS TODAY WILL BE
SLIGHTLY COOLER THAN YESTERDAY...I DID RAISE TEMPS A COUPLE OF
DEGREES OVER GUIDANCE WITH TEMPERATURES RISING INTO THE LOW 70S
FOR MOST AREAS IN NORTHERN ILLINOIS...WITH TEMPS SLIGHTLY COOLER
IN THE UPPER 60S IF NOT AROUND 70 MARK FOR AREAS NEAR THE LAKE.
NONETHELESS...A PLEASANT DAY WILL BE IN STORE FOR THE AREA TODAY.
AFTER QUIET CONDITIONS ONCE AGAIN TONIGHT INTO THE EARLY PORTIONS
OF MONDAY...A SOMEWHAT MORE ACTIVE WEATHER APPEARS TO BE ON THE
HORIZON. AS MID AND HIGH LEVEL CLOUD INCREASES FROM THE SOUTH ON
MONDAY...TEMPS SHOULD STILL RISE INTO THE LOW 70S ON MONDAY.
ALTHOUGH AS WAS EXPECTED OVER THE LAST 24 HOURS...MODELS CONTINUE
TO TREND TOWARDS BRINGING CURRENT CLOSED UPPER LEVEL LOW OVER THE
SOUTHERN PLAINS NORTHEAST TOWARDS THE AREA BY LATE MONDAY. MODEL
CONSENSUS SEEMS TO BRING THIS UPPER LEVEL SYSTEM AND SURFACE
REFLECTION UP THROUGH THE TENNESSEE VALLEY LATE MONDAY INTO EARLY
TUESDAY MORNING...AS A SEPARATE MID LEVEL TROUGH APPROACHES FROM
THE NORTHERN PLAINS. ALTHOUGH WITH A LACK OF MOISTURE WITH THIS
NORTHERN STREAM MID LEVEL TROUGH...PRECIP SHOULD BE DIMINISHING AS
IT APPROACHES THE CWA. BEST CHANCES FOR SHOWERS WILL BE FOR AREAS
ACROSS THE SOUTHEAST CWA MONDAY NIGHT. THIS SYSTEM WILL SLOWLY
SPIN ACROSS THE REGION...WITH PRECIP POSSIBLY LINGERING ACROSS
THE SAME AREA TUESDAY INTO TUESDAY NIGHT. CURRENT FORECAST KEEPS
PRECIP CHANCES THROUGH LATE IN THE DAY TUESDAY...BUT ITS
CONCEIVABLE THAT THIS SYSTEM WILL TAKE A SLOWER EASTWARD MOVEMENT.
IF THIS WERE TO OCCUR...PRECIP COULD LINGER INTO THE MIDDLE PART
OF THE WEEK BEFORE EXITING. AFTER WEAK RIDGING AND A SLIGHT
INCREASE IN TEMPS ON WEDNESDAY...ANOTHER MID LEVEL SYSTEM AND
SURFACE REFLECTION/FRONTAL BOUNDARY WILL APPROACH THE CWA WITH
PRECIP CHANCES INCREASING ONCE AGAIN TOWARDS THE END OF THE WORK
WEEK. IT WOULD APPEAR THAT MAINLY SHOWERS SHOULD BE OBSERVED AS
THIS SYSTEM PUSHES THROUGH THE AREA ON THURSDAY...BUT WITH SOME
UNCERTAINTY AS TO THE OVERALL AMOUNT OF MOISTURE/INSTABILITY
PRESENT OUT AHEAD OF IT. IF THE ECMWF WERE TO VERIFY...THEN
PRIMARILY SHOWERS WOULD BE OBSERVED. IN CONTRAST...THE GFS SEEMS
TO BE MORE AGGRESSIVE WITH DEWPOINTS AND IF THIS WERE TO
OCCUR...THEN THUNDERSTORMS COULD BE PRESENT OUT AHEAD OF THIS
SYSTEM.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE EFFECT CIGS BECMG MVFR INTO EARLY AFTERNOON...INITIALLY MAY
BE BRIEFLY BELOW 2 KFT...BUT SHOULD QUICKLY LIFT TO 2-2.5 KFT.
* NORTHEAST WINDS BECOMG GUSTY TO G15KT BY LATE MORNING.
* SMALL CHANCE FOR MVFR CIGS TONIGHT AND EARLY MONDAY MORNING.
KREIN
//DISCUSSION...UPDATED 12Z...
THE TERMINALS LIE BETWEEEN A COLD FRONT TO THE SOUTH WHICH PASSED
LATE YESTERDAY AND HIGH PRESSURE ACROSS ONTARIO AND QUEBEC. THE
GRADIENT BETWEEN THESE FEATURES WILL CONTINUE TO FAVOR A NORTHEAST
SYNOPTIC WIND. INITIALLY...THROUGH 14Z...A SLIGHTLY MORE NNW WIND
WILL BE SEEN ACROSS NORTHEAST IL DUE TO A REMNANT LAND BREEZE FROM
THE NIGHT. THIS IS AIDING CONVERGENCE INTO NORTHEAST IL THAT
SHOULD HELP TO FOCUS DEVELOPING CLOUDS OVER THE LAKE INTO
NORTHEAST IL BY MID MORNING...AND LIKELY TOWARD GYY AS WELL. THESE
LAKE ENHANCED CLOUDS ARE PRESENTLY FAVORED TO BE AT OR ABOVE 2000
FT BY THE TIME THEY ARRIVE AT THE TERMINALS...BUT AT ONSET SOME
COULD BE BELOW 2000 FT. THAT SHOULD BE BRIEF IF THAT OCCURS.
CLOUDS SHOULD GRADUALLY BECOME MORE SCATTERED THROUGH THE
AFTERNOON AS THE COLD AIR ADVECTION COMPONENT OVER THE WATER
WEAKENS. THE HIGH PRESSURE WILL SETTLE SOUTHWARD OVER THE AREA
THIS EVENING...WITH RETURN FLOW DEVELOPING ON MONDAY.
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN BROKEN CLOUDS BETWEEN 2000 AND 3500 FT.
MEDIUM CONFIDENCE IN TIMING. LOW CONFIDENCE IN ANY CIGS BELOW
2000 FT.
* HIGH CONFIDENCE IN WIND DIRECTIONAL TRENDS. MEDIUM CONFIDENCE
IN GUSTS.
* LOW CONFIDENCE IN ANY RETURNING BROKEN CIGS TONIGHT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...CHC FOR MVFR.
TUESDAY...SMALL CHC FOR MORNING VFR.
WEDNESDAY...VFR.
THURSDAY...CHC OF SHRA AND MVFR.
FRIDAY...WINDY. CHC OF SHRA AND MVFR
SATURDAY...VFR.
MTF
&&
.MARINE...
224 AM CDT
BEHIND A COOL FRONT WHICH PASSED LATE ON SATURDAY...NORTHEAST FLOW
WILL CONTINUE ACROSS THE LAKE TODAY. THIS WILL BE DIRECTED INTO THE
NEARSHORE AREAS OF ILLINOIS AND INDIANA...FAVORING HIGH WAVES INTO
THE AFTERNOON AND EVENING. HIGH PRESSURE WILL SLIDE SOUTHWARD OVER
THE LAKE TONIGHT INTO EARLY MONDAY EASING WINDS. A WEAK COOL FRONT
WILL PASS FROM WEST TO EAST OVER THE LAKE ON MONDAY NIGHT...OFFERING
A WIND SHIFT BUT NO REAL INCREASE IN SPEED. THAT IS IN PART BECAUSE
LOW PRESSURE WILL BE MOVING NORTHEASTWARD FROM THE LOWER OHIO VALLEY
TO HUDSON BAY TUESDAY INTO WEDNESDAY SLOWING THE AFOREMENTIONED
BOUNDARY. A POTENTIALLY ACTIVE END OF THE WEEK OVER THE WESTERN
GREAT LAKES MAY BE IN STORE AS SEVERAL FORECAST MODELS INDICATE A
STRONG LOW PRESSURE SOMEWHERE IN THE UPPER MIDWEST/GREAT LAKES
REGION...WITH STRONG THERMAL ADVECTION CONDUCIVE FOR GUSTY WINDS
AHEAD AND BEHIND OF THE LOW PRESSURE.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ006-ILZ014 UNTIL 4 AM MONDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002 UNTIL 4 AM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
406 PM CDT SUN SEP 30 2012
...CORRECTED THE LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1212 PM CDT SUN SEP 30 2012
AT 12Z SUNDAY AN UPPER LEVEL JET STREAK EXTENDED FROM NORTHWEST
MONTANA INTO SOUTHERN BRITISH COLUMBIA. AT THE 500MB LEVEL A -14
TO -15C THERMAL TROUGH EXTENDED FROM NORTH DAKOTA INTO SOUTHWEST
NEBRASKA. ANOTHER COLDER UPPER LEVEL THERMAL TROUGH WAS LOCATED
NEAR THE LEFT EXIT REGION THE UPPER LEVEL JET LOCATED NEAR
SOUTHERN SASKATCHEWAN AND SOUTHERN ALBERTA CANADA. AT THE 700MB
LEVEL A +5 TO +7C THERMAL RIDGE EXTENDED FROM SOUTHERN SOUTH DAKOTA
INTO NORTHEAST COLORADO WITH SOME 700-600MB MOISTURE AND MID LEVEL
INSTABILITY PRESENT IN THIS AREA BASED ON THE NORTH PLATTE
SOUNDING AND RAP. MOSAIC RADAR LOOP ALSO PICKED UP ON A FEW
ISOLATED SHOWERS AND THUNDERSTORMS IN THIS AREA. NEAR THE SURFACE
A TROUGH OF LOW PRESSURE STRETCHED FROM CENTRAL NEBRASKA INTO WEST
CENTRAL KANSAS WITH A WEDGE OF HIGHER MOISTURE PRESENT AHEAD OF
THIS TROUGH BASED THE EARLY MORNING STATUS/FOG, LOW TO MID 50S
SURFACE DEWPOINTS, AND +10 TO +12C 850MB DEWPOINTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 143 PM CDT SUN SEP 30 2012
LATEST RAP WAS CONSISTENT WITH THE 12Z NAM AND THEY BOTH VERIFIED
FAIRLY WELL WITH THE LOCATION OF THE SURFACE LEE TROUGH WHICH WAS
LOCATED ACROSS FAR WESTERN KANSAS. AHEAD OF THIS SURFACE BOUNDARY
A 0-1KM THTA-E RIDGE AXIS EXTENDED NORTHWARD INTO SOUTHWEST
NEBRASKA. THIS FEATURE IS FORECAST TO MOVE VERY LITTLE THROUGH
EARLY TONIGHT AND WILL BE THE AREA WHERE THE BETTER LOW LEVEL
FORCING WILL BE LATE TODAY AS 500MB TEMPERATURE COOL AND
INSTABILITY IMPROVES. WILL THEREFORE RETAIN MENTION OF LATE
DAY/EARLY NIGHT THUNDERSTORMS ACROSS MAINLY SOUTHWEST AND NORTH
CENTRAL KANSAS.
THE UPPER LEVEL JET LOCATED OVER MONTANA EARLIER TODAY WILL DIVE
SOUTH ALONG THE WESTERN HIGH PLAINS AND BY EARLY MONDAY THE LEFT
EXIT REGION OF THIS JET IS FORECAST TO BE LOCATED OVER WESTERN
KANSAS. BUFR SOUNDINGS ALSO SUGGESTING MOISTURE WILL BE PRESENT
AROUND THE 700MB LEVEL EARLY IN THE DAY AS A COLD FRONT MOVES
SOUTH ACROSS SOUTHWEST KANSAS. BASED ON THE LOCATION OF THE UPPER
JET, BETTER 700MB MOISTURE ALONG WITH SOME FRONTOGENESIS WILL
RETAIN MENTION OF PRECIPITATION EARLY IN THE DAY. BUFR SOUNDING WIND
PROFILES INDICATED 30KTS AT 800MB LEVEL BEHIND THIS FRONT WITH
MEAN MIXED LEVEL WINDS SUGGESTING WINDS SPEEDS IN THE 20 TO 30 MPH
RANGE WILL BE POSSIBLE. 850MB TEMPERATURES AT 00Z TUESDAY SUGGESTS
HIGHS WILL BE IN THE LOW TO MID 70S WHICH WERE SIMILAR TO THE
MOSGUIDE, AND CONSMOS. THIS ALSO ONLY A FEW DEGREES COOLER THAN
THE PREVIOUS FORECAST SO GIVEN A SLIGHT SUPER NEAR THE SURFACE THE
PREVIOUS FORECAST WITH HIGHS MAINLY IN THE 75 TO NEAR 80 DEGREE
RANGE STILL APPEARS ON TRACK.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 401 PM CDT SUN SEP 30 2012
NORTHERLY UPPER-LEVEL FLOW WILL PERSIST TUESDAY ON THE BACK SIDE OF AN
UPPER LOW. IN THE ABSENCE OF LEE TROUGHING, PLEASANT WEATHER CAN
BE EXPECTED. IT WILL BE FAIRLY COOL IN THE LOWER 40S IN THE
MORNING GIVEN THE DRY AIR AND LIGHT WINDS. THE AFTERNOON WILL TURN
OUT PLEASANT WITH HIGHS IN THE LOWER TO MID 70S AND LIGHT WINDS. A
STRONG SHORTWAVE TROUGH WILL PROGRESS SOUTHEASTWARD OUT OF CANADA
INTO THE NORTHERN PLAINS BY WEDNESDAY. AHEAD OF THE ASSOCIATED
COLD FRONT, TEMPERATURES SHOULD REACH INTO THE UPPER 70S IN PLACES
LIKE SCOTT CITY AND DIGHTON, WITH WARMER 80S FROM DODGE CITY INTO
SOUTH CENTRAL KANSAS. SOME MID-LEVEL MOISTURE WILL ACCOMPANY THIS
SYSTEM AFTER THE LOW-LEVEL BAROCLINIC ZONE MOVES THROUGH AND THE
JET STREAK APPROACHES. SO A FEW RAIN SHOWERS CANNOT BE RULED OUT
WEDNESDAY NIGHT, ESPECIALLY FROM DODGE CITY NORTHWARD TO THE
INTERSTATE 70 CORRIDOR.
THERE ARE MAJOR DISAGREEMENTS AMONG THE VARIOUS MODELS BY
THURSDAY AND THROUGH THE WEEKEND. THE ECMWF DEVELOPS A POSITIVELY
TILTED UPPER-LEVEL TROUGH FROM WINNIPEG SOUTHWESTWARD TO THE
CALIFORNIA COAST, WHILE THE GFS DEVELOPS A LARGE TROUGH OVER THE
GREAT LAKES REGION, WITH A CUTOFF LOW OFF OF THE WEST COAST.
INTERESTINGLY, EVEN THOUGH THE PATTERNS ARE DIFFERENT IN THE
GFS/ECMWF, THEY BOTH SHOW MID-LEVEL FRONTOGENESIS AND SOME
POSSIBLE LIGHT RAIN FOR FRIDAY NIGHT. OTHER THAN THAT, BOTH MODELS
SHOW SURFACE HIGH PRESSURE ENTRENCHED ACROSS THE PLAINS WITH
FAIRLY COOL HIGHS MAINLY IN THE LOWER TO MID 60S FOR THURSDAY AND
FRIDAY AND LOWS DROPPING INTO THE 40S. BY SATURDAY AND SUNDAY,
THE GFS KEEPS A NORTHWESTERLY UPPER-LEVEL FLOW REGIME OVER THE
PLAINS AS UPPER TROUGHING PERSISTS OVER THE GREAT LAKES. THIS
WOULD BE A COOL AND MAINLY DRY REGIME. THE ECMWF INDICATES
ISENTROPIC LIFT AS LOW LEVEL COOL AIR BECOMES WEDGED UNDERNEATH
THE WEST- SOUTHWESTERLY MID-LEVEL FLOW. THIS WOULD YIELD A CLOUDY
PATTERN WITH PERHAPS SOME AREAS OF LIGHT RAIN SATURDAY AND SUNDAY,
AND POSSIBLY EVEN SNOW BY SUNDAY NIGHT. THE UKMET IS SIMILAR TO
THE ECMWF AT DAY 6 WHILE THE GEM AGREES MORE WITH THE GFS. DUE TO
THE GREAT UNCERTAINTY, WE JUST OPTED TO GO WITH THE ALLBLEND
INITIALIZATION, WHICH FEATURES COOL BUT DRY WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1212 PM CDT SUN SEP 30 2012
SCATTERED CONVECTION WILL BE POSSIBLE THIS AFTERNOON AND EARLY
THIS EVENING UNDER A -14 TO -15C 500MB THERMAL TROUGH AS IT MOVES
ACROSS WESTERN KANSAS. BASED ON THE LOCATION OF THE THTA-E RIDGE
AXIS AHEAD OF THE SURFACE BOUNDARY AND TIMING OF THE UPPER LEVEL
TROUGH BY THE NAM/RAP WILL FOCUS ANY THUNDERSTORM CHANCES PRIOR TO
00Z AT GCK AND HYS. AT DDC THE CONVECTION SHOULD HOLD OFF UNTIL
AFTER 21Z WITH A VCTS THROUGH 03Z. BUFR SOUNDINGS INDICATING CIGS
WILL BE AT OR ABOVE 3000FT SO VFR CONDITIONS ARE EXPECTED.
ALTHOUGH COULD SEE SOME GUSTY WINDS NEAR THESE ISOLATED THUNDERSTORMS
LATER TODAY THE AVERAGE WIND SPEED IS EXPECTED TO BE AT 10KTS OR
LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 76 40 74 / 30 20 0 0
GCK 52 75 41 75 / 40 20 0 0
EHA 52 75 42 76 / 60 20 0 0
LBL 52 76 42 75 / 60 20 0 0
HYS 52 76 41 74 / 20 20 0 0
P28 53 80 46 74 / 10 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 PM CDT SUN SEP 30 2012
...UPDATED FOR LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1212 PM CDT SUN SEP 30 2012
AT 12Z SUNDAY AN UPPER LEVEL JET STREAK EXTENDED FROM NORTHWEST
MONTANA INTO SOUTHERN BRITISH COLUMBIA. AT THE 500MB LEVEL A -14
TO -15C THERMAL TROUGH EXTENDED FROM NORTH DAKOTA INTO SOUTHWEST
NEBRASKA. ANOTHER COLDER UPPER LEVEL THERMAL TROUGH WAS LOCATED
NEAR THE LEFT EXIT REGION THE UPPER LEVEL JET LOCATED NEAR
SOUTHERN SASKATCHEWAN AND SOUTHERN ALBERTA CANADA. AT THE 700MB
LEVEL A +5 TO +7C THERMAL RIDGE EXTENDED FROM SOUTHERN SOUTH DAKOTA
INTO NORTHEAST COLORADO WITH SOME 700-600MB MOISTURE AND MID LEVEL
INSTABILITY PRESENT IN THIS AREA BASED ON THE NORTH PLATTE
SOUNDING AND RAP. MOSAIC RADAR LOOP ALSO PICKED UP ON A FEW
ISOLATED SHOWERS AND THUNDERSTORMS IN THIS AREA. NEAR THE SURFACE
A TROUGH OF LOW PRESSURE STRETCHED FROM CENTRAL NEBRASKA INTO WEST
CENTRAL KANSAS WITH A WEDGE OF HIGHER MOISTURE PRESENT AHEAD OF
THIS TROUGH BASED THE EARLY MORNING STATUS/FOG, LOW TO MID 50S
SURFACE DEWPOINTS, AND +10 TO +12C 850MB DEWPOINTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 143 PM CDT SUN SEP 30 2012
LATEST RAP WAS CONSISTENT WITH THE 12Z NAM AND THEY BOTH VERIFIED
FAIRLY WELL WITH THE LOCATION OF THE SURFACE LEE TROUGH WHICH WAS
LOCATED ACROSS FAR WESTERN KANSAS. AHEAD OF THIS SURFACE BOUNDARY
A 0-1KM THTA-E RIDGE AXIS EXTENDED NORTHWARD INTO SOUTHWEST
NEBRASKA. THIS FEATURE IS FORECAST TO MOVE VERY LITTLE THROUGH
EARLY TONIGHT AND WILL BE THE AREA WHERE THE BETTER LOW LEVEL
FORCING WILL BE LATE TODAY AS 500MB TEMPERATURE COOL AND
INSTABILITY IMPROVES. WILL THEREFORE RETAIN MENTION OF LATE
DAY/EARLY NIGHT THUNDERSTORMS ACROSS MAINLY SOUTHWEST AND NORTH
CENTRAL KANSAS.
THE UPPER LEVEL JET LOCATED OVER MONTANA EARLIER TODAY WILL DIVE
SOUTH ALONG THE WESTERN HIGH PLAINS AND BY EARLY MONDAY THE LEFT
EXIT REGION OF THIS JET IS FORECAST TO BE LOCATED OVER WESTERN
KANSAS. BUFR SOUNDINGS ALSO SUGGESTING MOISTURE WILL BE PRESENT
AROUND THE 700MB LEVEL EARLY IN THE DAY AS A COLD FRONT MOVES
SOUTH ACROSS SOUTHWEST KANSAS. BASED ON THE LOCATION OF THE UPPER
JET, BETTER 700MB MOISTURE ALONG WITH SOME FRONTOGENESIS WILL
RETAIN MENTION OF PRECIPITATION EARLY IN THE DAY. BUFR SOUNDING WIND
PROFILES INDICATED 30KTS AT 800MB LEVEL BEHIND THIS FRONT WITH
MEAN MIXED LEVEL WINDS SUGGESTING WINDS SPEEDS IN THE 20 TO 30 MPH
RANGE WILL BE POSSIBLE. 850MB TEMPERATURES AT 00Z TUESDAY SUGGESTS
HIGHS WILL BE IN THE LOW TO MID 70S WHICH WERE SIMILAR TO THE
MOSGUIDE, AND CONSMOS. THIS ALSO ONLY A FEW DEGREES COOLER THAN
THE PREVIOUS FORECAST SO GIVEN A SLIGHT SUPER NEAR THE SURFACE THE
PREVIOUS FORECAST WITH HIGHS MAINLY IN THE 75 TO NEAR 80 DEGREE
RANGE STILL APPEARS ON TRACK.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 351 PM CDT SUN SEP 30 2012
NORTHERLY UPPER-LEVEL FLOW WILL PERSIST TUESDAY ON THE BACK SIDE OF AN
UPPER LOW. IN THE ABSENCE OF LEE TROUGHING, PLEASANT WEATHER CAN
BE EXPECTED. IT WILL BE FAIRLY COOL IN THE LOWER 40S IN THE
MORNING GIVEN THE DRY AIR AND LIGHT WINDS. THE AFTERNOON WILL TURN
OUT PLEASANT WITH HIGHS IN THE LOWER TO MID 70S AND LIGHT WINDS. A
STRONG SHORTWAVE TROUGH WILL PROGRESS SOUTHEASTWARD OUT OF CANADA
INTO THE NORTHERN PLAINS BY WEDNESDAY. AHEAD OF THE ASSOCIATED
COLD FRONT, TEMPERATURES SHOULD REACH INTO THE UPPER 70S IN PLACES
LIKE SCOTT CITY AND DIGHTON, WITH WARMER 80S FROM DODGE CITY INTO
SOUTH CENTRAL KANSAS. SOME MID-LEVEL MOISTURE WILL ACCOMPANY THIS
SYSTEM AFTER THE LOW-LEVEL BAROCLINIC ZONE MOVES THROUGH AND THE
JET STREAK APPROACHES. SO A FEW RAIN SHOWERS CANNOT BE RULED OUT
WEDNESDAY NIGHT, ESPECIALLY FROM DODGE CITY NORTHWARD TO THE
INTERSTATE 70 CORRIDOR.
THERE ARE MAJOR DISAGREEMENTS AMONG THE VARIOUS MODELS BY
THURSDAY AND THROUGH THE WEEKEND. THE ECMWF DEVELOPS A POSITIVELY
TILTED UPPER-LEVEL TROUGH FROM WINNIPEG SOUTHWESTWARD TO THE
CALIFORNIA COAST, WHILE THE GFS DEVELOPS A LARGE TROUGH OVER THE
GREAT LAKES REGION, WITH A CUTOFF LOW OFF OF THE WEST COAST.
INTERESTINGLY, EVEN THOUGH THE PATTERNS ARE DIFFERENT IN THE
GFS/ECMWF, THEY BOTH SHOW MID-LEVEL FRONTOGENESIS AND SOME
POSSIBLE LIGHT RAIN FOR FRIDAY NIGHT. OTHER THAN THAT, BOTH MODELS
SHOW SURFACE HIGH PRESSURE ENTRENCHED ACROSS THE PLAINS WITH
FAIRLY COOL HIGHS IN THE LOWER TO MID 60S FOR THURSDAY AND FRIDAY.
BY SATURDAY AND SUNDAY, THE GFS KEEPS A NORTHWESTERLY UPPER-LEVEL
FLOW REGIME OVER THE PLAINS AS UPPER TROUGHING PERSISTS OVER THE
GREAT LAKES. THIS WOULD BE A COOL AND MAINLY DRY REGIME. THE ECMWF
INDICATES ISENTROPIC LIFT AS LOW LEVEL COOL AIR BECOMES WEDGED
UNDERNEATH THE WEST-SOUTHWESTERLY MID-LEVEL FLOW. THIS WOULD YIELD
A CLOUDY PATTERN WITH PERHAPS SOME AREAS OF LIGHT RAIN SATURDAY
AND SUNDAY, AND POSSIBLY EVEN SNOW BY SUNDAY NIGHT. THE UKMET IS
SIMILAR TO THE ECMWF AT DAY 6 WHILE THE GEM AGREES MORE WITH THE
GFS. DUE TO THE GREAT UNCERTAINTY, WE JUST OPTED TO GO WITH THE
ALLBLEND INITIALIZATION, WHICH FEATURES COOL BUT DRY WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1212 PM CDT SUN SEP 30 2012
SCATTERED CONVECTION WILL BE POSSIBLE THIS AFTERNOON AND EARLY
THIS EVENING UNDER A -14 TO -15C 500MB THERMAL TROUGH AS IT MOVES
ACROSS WESTERN KANSAS. BASED ON THE LOCATION OF THE THTA-E RIDGE
AXIS AHEAD OF THE SURFACE BOUNDARY AND TIMING OF THE UPPER LEVEL
TROUGH BY THE NAM/RAP WILL FOCUS ANY THUNDERSTORM CHANCES PRIOR TO
00Z AT GCK AND HYS. AT DDC THE CONVECTION SHOULD HOLD OFF UNTIL
AFTER 21Z WITH A VCTS THROUGH 03Z. BUFR SOUNDINGS INDICATING CIGS
WILL BE AT OR ABOVE 3000FT SO VFR CONDITIONS ARE EXPECTED.
ALTHOUGH COULD SEE SOME GUSTY WINDS NEAR THESE ISOLATED THUNDERSTORMS
LATER TODAY THE AVERAGE WIND SPEED IS EXPECTED TO BE AT 10KTS OR
LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 76 40 74 / 20 20 0 0
GCK 52 75 41 75 / 30 20 0 0
EHA 52 75 42 76 / 40 20 0 0
LBL 52 76 42 75 / 30 20 0 0
HYS 52 76 41 74 / 20 20 0 0
P28 53 80 46 74 / 10 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
148 PM CDT SUN SEP 30 2012
...UPDATED SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1212 PM CDT SUN SEP 30 2012
AT 12Z SUNDAY AN UPPER LEVEL JET STREAK EXTENDED FROM NORTHWEST
MONTANA INTO SOUTHERN BRITISH COLUMBIA. AT THE 500MB LEVEL A -14
TO -15C THERMAL TROUGH EXTENDED FROM NORTHERN DAKOTA INTO
SOUTHWEST NEBRASKA. ANOTHER COLDER UPPER LEVEL THERMAL TROUGH WAS
LOCATED NEAR THE LEFT EXIT REGION THE UPPER LEVEL JET LOCATED NEAR
SOUTHERN SASKATCHEWAN AND SOUTHERN ALBERTA CANADA. AT THE 700MB
LEVEL A +5 TO +7C THERMAL RIDGE EXTENDED FROM SOU TERN SOUTH DAKOTA
INTO NORTHEAST COLORADO WITH SOME 700-600MB MOISTURE AND MID LEVEL
INSTABILITY PRESENT IN THIS AREA BASED ON THE NORTH PLATTE
SOUNDING AND RAP. MOSAIC RADAR LOOP ALSO PICKED UP ON A FEW ISOLATED
SHOWERS AND THUNDERSTORMS IN THIS AREA. NEAR THE SURFACE A TROUGH
OF LOW PRESSURE STRETCHED FROM CENTRAL NEBRASKA INTO WEST CENTRAL
KANSAS WITH A WEDGE OF HIGHER MOISTURE PRESENT AHEAD OF THIS
TROUGH BASED THE EARLY MORNING STATUS/FOG, LOW TO MID 50S SURFACE
DEWPOINTS, AND +10 TO +12C 850MB DEWPOINTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 143 PM CDT SUN SEP 30 2012
LATEST RAP WAS CONSISTENT WITH THE 12Z NAM AND THEY BOTH VERIFIED
FAIRLY WELL WITH THE LOCATION OF THE SURFACE LEE TROUGH WHICH WAS
LOCATED ACROSS FAR WESTERN KANSAS. AHEAD OF THIS SURFACE BOUNDARY
A 0-1KM THTA-E RIDGE AXIS EXTENDED NORTHWARD INTO SOUTHWEST
NEBRASKA. THIS FEATURE IS FORECAST TO MOVE VERY LITTLE THROUGH
EARLY TONIGHT AND WILL BE THE AREA WHERE THE BETTER LOW LEVEL
FORCING WILL BE LATE TODAY AS 500MB TEMPERATURE COOL AND
INSTABILITY IMPROVES. WILL THEREFORE RETAIN MENTION OF LATE
DAY/EARLY NIGHT THUNDERSTORMS ACROSS MAINLY SOUTHWEST AND NORTH
CENTRAL KANSAS.
THE UPPER LEVEL JET LOCATED OVER MONTANA EARLIER TODAY WILL DIVE
SOUTH ALONG THE WESTERN HIGH PLAINS AND BY EARLY MONDAY THE LEFT
EXIT REGION OF THIS JET IS FORECAST TO BE LOCATED OVER WESTERN
KANSAS. BUFR SOUNDINGS ALSO SUGGESTING MOISTURE WILL BE PRESENT
AROUND THE 700MB LEVEL EARLY IN THE DAY AS A COLD FRONT MOVES
SOUTH ACROSS SOUTHWEST KANSAS. BASED ON THE LOCATION OF THE UPPER
JET, BETTER 700MB MOISTURE ALONG WITH SOME FRONTOGENESIS WILL
RETAIN MENTION OF PRECIPITATION EARLY IN THE DAY. BUFR SOUNDING WIND
PROFILES INDICATED 30KTS AT 800MB LEVEL BEHIND THIS FRONT WITH
MEAN MIXED LEVEL WINDS SUGGESTING WINDS SPEEDS IN THE 20 TO 30 MPH
RANGE WILL BE POSSIBLE. 850MB TEMPERATURES AT 00Z TUESDAY SUGGESTS
HIGHS WILL BE IN THE LOW TO MID 70S WHICH WERE SIMILAR TO THE
MOSGUIDE, AND CONSMOS. THIS ALSO ONLY A FEW DEGREES COOLER THAN
THE PREVIOUS FORECAST SO GIVEN A SLIGHT SUPER NEAR THE SURFACE THE
PREVIOUS FORECAST WITH HIGHS MAINLY IN THE 75 TO NEAR 80 DEGREE
RANGE STILL APPEARS ON TRACK.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 327 AM CDT SUN SEP 30 2012
MONDAY INTO TUESDAY WILL SEE AN UPPER TROUGH POSITIONED FROM THE
HUDSON BAY REGION OF CANADA INTO THE LOWER MISSISSIPPI RIVER
VALLEY. AN 80-100 KNOT JET STREAK ON THE BACK SIDE OF THE TROUGH
WILL NOSE INTO THE CENTRAL PLAINS MONDAY BEFORE THE CORE OF STRONGER
JET WINDS ROTATE ONTO THE FRONT SIDE OF THE TROUGH AXIS BY EARLY
TUESDAY. UPSTREAM FROM THIS TROUGH A HIGH AMPLITUDE RIDGE WILL
EXIST OFF THE WEST COAST WHILE A POTENT WAVE AND ASSOCIATED 100
KNOT JET STREAK DIGS INTO THE PACIFIC NORTHWEST STATES. THIS WILL
LEAVE THE CENTRAL PLAINS UNDER A PROGRESSIVE NORTHWEST FLOW REGIME
WITH THE AFOREMENTIONED JET STREAK AND ASSOCIATED SHORTWAVE AIDING
IN PUSHING A WEAK FRONT THROUGH WESTERN KANSAS MONDAY MORNING.
FURTHER, THE LEFT EXIT REGION OF THIS JET WILL INTERACT WITH AN
800-700 HPA BAROCLINIC ZONE TO PRODUCE A MODEST BAND OF
FRONTOGENESIS AND RESULTANT ASCENT OVER WESTERN AND CENTRAL KANSAS
MONDAY MORNING TO EARLY AFTERNOON. EXPECT THIS FORCING WILL BE
ENOUGH TO TRIGGER AT LEAST SOME ISOLATED TO SCATTERED SHOWERS
THROUGH EARLY AFTERNOON ALTHOUGH PRECIPITATION AMOUNTS WILL BE LIGHT.
OTHERWISE...GOOD SOLAR INSOLATION BY MID AFTERNOON ALONG WITH 850
HPA TEMPERATURES BETWEEN +14 TO +18C SHOULD SUPPORT HIGHS IN THE
UPPER 70S TO LOWER 80S BOTH MONDAY AND TUESDAY.
WEDNESDAY WILL BE A TRANSITION DAY AHEAD OF A MAJOR PATTERN CHANGE
ANTICIPATED ON THURSDAY AS THE AFOREMENTIONED UPPER WAVE DIGS
SOUTHEAST INTO THE PLAINS STATES. THIS WILL PUSH A POTENT COLD
FRONT THROUGH WESTERN KANSAS WEDNESDAY NIGHT INTO THURSDAY MORNING
WITH MUCH COLDER AIR EXPECTED BEHIND THE BOUNDARY. NONETHELESS...AHEAD
OF THE FRONT MOST OF WEDNESDAY WILL BE WARM AND DRY AS THE
APPROACHING WAVE AIDS IN DEEPENING THE LEE TROUGH OVER EASTERN
COLORADO WHILE A SURFACE LOW TRACKS ACROSS THE DAKOTAS. THIS WILL
ALLOW MODEST SOUTH TO SOUTHWEST WINDS AHEAD OF THE TROUGH AXIS
KEEP 850 HPA TEMPERATURES AROUND 20C WITH HIGHS IN THE 80S
EXPECTED. HOWEVER, STRONG COLD AIR ADVECTION BEHIND THE BOUNDARY
WILL LOWER TEMPERATURES QUICKLY ON THURSDAY WITH 850 HPA TEMPS OF
+5 TO +10C AND RESULTANT HIGHS IN THE 60S EXPECTED BY AFTERNOON. THE
UPPER WAVE THEN EJECTS NORTHEAST INTO THE GREAT LAKES TO HUDSON
BAY REGION ON FRIDAY WHILE A SECOND MORE POTENT WAVE DIGS INTO THE
NORTHERN ROCKIES. THIS WILL INITIALLY STALL THE FIRST BOUNDARY
OVER THE SOUTHERN PLAINS BY FRIDAY MORNING BEFORE A SECOND FRONT
SURGES THROUGH THE REGION FRIDAY NIGHT. IN ADDITION...JET DYNAMICS
ARE SHOWN TO INTERACT WITH A MID LEVEL BAROCLINIC ZONE TO PRODUCE
AN AREA OF FRONTOGENESIS AND RESULTANT ASCENT ACROSS WESTERN
KANSAS FRIDAY NIGHT INTO EARLY SATURDAY. THIS MAY RESULT IN A
CHANCE FOR SOME LIGHT RAIN ALTHOUGH THE MAIN STORY WILL LIKELY BE
COOLER TEMPERATURES WITH HIGHS IN THE UPPER 50S TO LOWER 60S AND
LOWS POSSIBLE IN THE 30S TO LOWER 40S EXPECTED NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1212 PM CDT SUN SEP 30 2012
SCATTERED CONVECTION WILL BE POSSIBLE THIS AFTERNOON AND EARLY
THIS EVENING UNDER A -14 TO -15C 500MB THERMAL TROUGH AS IT MOVES
ACROSS WESTERN KANSAS. BASED ON THE LOCATION OF THE THTA-E RIDGE
AXIS AHEAD OF THE SURFACE BOUNDARY AND TIMING OF THE UPPER LEVEL
TROUGH BY THE NAM/RAP WILL FOCUS ANY THUNDERSTORM CHANCES PRIOR TO
00Z AT GCK AND HYS. AT DDC THE CONVECTION SHOULD HOLD OFF UNTIL
AFTER 21Z WITH A VCTS THROUGH 03Z. BUFR SOUNDINGS INDICATING CIGS
WILL BE AT OR ABOVE 3000FT SO VFR CONDITIONS ARE EXPECTED.
ALTHOUGH COULD SEE SOME GUSTY WINDS NEAR THESE ISOLATED THUNDERSTORMS
LATER TODAY THE AVERAGE WIND SPEED IS EXPECTED TO BE AT 10KTS OR
LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 77 45 78 / 30 20 0 0
GCK 52 77 44 79 / 30 20 0 0
EHA 52 77 47 80 / 20 20 0 0
LBL 52 78 45 78 / 30 20 0 0
HYS 52 77 44 78 / 30 20 0 0
P28 53 81 48 78 / 10 20 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...AJOHNSON
AVIATION...BURGERT
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
537 PM EDT SUN SEP 30 2012
.SYNOPSIS...
LOW PRESSURE OVER THE BAY OF FUNDY WILL LIFT NORTH THROUGH EASTERN
QUEBEC TONIGHT AND MONDAY. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD
OVER NEW ENGLAND MONDAY NIGHT AND WILL HOLD OVER THE AREA ON
TUESDAY. A TROUGH OF LOW PRESSURE WILL SLOWLY MOVE NORTHWARD UP THE
EAST COAST TUESDAY NIGHT AND WEDNESDAY. A COLD FRONT WILL APPROACH
FROM THE WEST WEDNESDAY NIGHT AND WILL CROSS THE REGION ON THURSDAY.
ANOTHER COLD FRONT WILL APPROACH FROM THE THE WEST ON FRIDAY AND
WILL PUSH EAST THROUGH THE REGION FRIDAY NIGHT. A WEAK RIDGE OF HIGH
PRESSURE WILL BUILD IN BEHIND THE FRONT ON SATURDAY AND WILL HOLD
OVER THE REGION ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATE...WITH SFC LOW PRES NEARING THE COAST OF DOWNEAST ME WINDS
ARE BEGINNING TO TURN MORE WLY ACROSS MUCH OF THE CWFA. WILL SEE
THESE GRADUALLY INCREASE OVER THE WATERS...AND SCA IN PLACE LOOKS
GOOD FOR TNGT. WILL ALSO SEE WLY WINDS HELP CLEAR OUT COASTAL AND
ADJACENT INTERIOR PORTIONS OF SRN NH AND SWRN ME. DIURNALLY DRIVEN
CONVECTION UNDER THE UPR LOW WILL CONTINUE TO MOVE NEWD THIS EVE.
EXPECT A GRADUAL WEAKENING WITH LOSS OF DAYTIME HEATING...BUT HI
RES MODELS SUGGEST THEY WILL HOLD TOGETHER LONG ENOUGH TO AFFECT
PARTS OF THE FAR SRN CWFA. HAVE HELD ONTO CHC POP HERE LONGER THAN
THE REST OF THE COAST FOR THIS REASON. A BLEND OF THE PREVIOUS
FCST WITH LATEST HRRR POP FIELD LOOKED LIKE A GOOD APPROXIMATION
FOR TIMING AND HAVE USED THIS THRU THE OVERNIGHT.
PREVIOUS DISCUSSION...SURFACE LOW PRESSURE CONTINUES TO MOVE
NORTHWARD AND INTO DOWNEAST MAINE AS OF LATE THIS SUNDAY
AFTERNOON. AS IT DOES SO...THE SHIELD OF STRATIFORM RAIN CONTINUES
TO MOVE NORTHWARD AS WELL...WITH THE BACK EDGE ALONG A LINE FROM
PORTLAND ME WESTWARD TO LITTLETON NH. THE STEADY RAINFALL WILL END
WITH THE NORTHWARD PASSAGE OF THE BACK EDGE. HOWEVER...THE STRONG
UPPER LOW IS STILL APPROACHING FROM THE WEST...SO SHOWERY
PRECIPITATION IS DEVELOPING IN THE DRIER AREA TO THE SOUTHWEST.
THEREFORE...HAVE NOT SCALED BACK ON POPS TOO MUCH IN THE SOUTH
EARLY THIS EVENING. CANNOT RULE OUT AN ISOLD THUNDERSTORM ACROSS
SOUTHERN NH TIL ABOUT 00Z...BUT DECIDED TO LEAVE OUT OF FORECAST
AS PROBABILITY SEEMS LOW AT THIS TIME.
AFTER DARK...THE SHOWERY PRECIP WILL WANE. THIS SHOULD LEAVE THE
SOUTHERN ZONES AND COASTAL PLAIN MAINLY DRY OVERNIGHT.
HOWEVER...DIDN/T GET RID OF POPS COMPLETELY...AS UPPER LOW IS
STRONG ENOUGH TO INDUCE A FEW SHOWERS FROM TIME TO TIME. IT/S ALSO
POSSIBLE THAT A LARGER AREA OF WRAP AROUND SHOWERS DEVELOPS LATE
ALSO.
ACROSS CENTRAL AND NORTHERN NH AND THE WESTERN ME
MOUNTAINS...EXPECT NUMEROUS SHOWERS TO CONTINUE OVERNIGHT...WITH A
GOOD CONTRIBUTION COMING FROM WESTERLY UPSLOPE.
MIN TEMPS BASED ON A BLEND OF THE MET/MAV/NAM GUIDANCE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
STACKED LOW PRESSURE SYSTEM WILL LIKELY BE CENTERED OVER MAINE 8
AM MONDAY MORNING WITH WRAP AROUND SHOWERY PRECIP LIKELY OCCURRING
OVER MUCH OF THE AREA. THE HIGHEST CONCENTRATION WILL BE OVER THE
MOUNTAINS. CANNOT RULE OUT AN ISOLATED THUNDERSTORM WITH STEEP
LAPSE RATES IN PLACE...BUT PROBABILITY IS A LITTLE TO LOW AT THIS
TIME TO INCLUDE IN THE FORECAST. TIMING OF UPPER LOW PASSAGE IS
JUST A LITTLE TOO QUICK WITH RESPECT TO DAYTIME HEATING AT THIS
TIME.
OTHERWISE...GRADUAL DRYING TAKES PLACE MONDAY AFTERNOON. UPSLOPE
SHOWERS PROBABLY STILL OCCUR IN THE MOUNTAINS HOWEVER.
CLEARING MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL PROVIDE MOSTLY SUNNY SKIES ON TUESDAY AS HIGH
PRESSURE HOLDS OVER THE REGION. WILL LIKELY SEE SOME VARIABLE HIGH
CLOUDINESS BUT IT SHOULD NOT HAVE MUCH AFFECT ON TEMPS WHICH WILL
TOP OUT IN THE MID 60S TO NEAR 70 IN THE NORTH AND LOWER TO MID 70S
IN THE SOUTH.
SLOW MOVING AREA OF LOW PRESSURE OVER THE OHIO VALLEY WILL BRING
INCREASING CLOUDS TO THE REGION TUESDAY NIGHT AND WEDNESDAY.
INCREASINGLY MOIST ONSHORE FLOW WILL BRING OCEAN STRATUS INTO
SOUTHERN NEW ENGLAND DURING THE DAY TUESDAY AND THIS WILL GRADUALLY
LIFT NORTHWARD TUESDAY NIGHT AND WEDNESDAY. THIS WILL KEEP TEMPS UP
TUESDAY NIGHT BUT WILL HOLD READINGS DOWN ON WEDNESDAY...ESPECIALLY
IN SOUTHERN ZONES. IN ADDITION WILL BE GOING WITH LOW CHANCE POPS FOR
SCATTERED SHOWERS LATE TUESDAY NIGHT IN SOUTHWEST ZONES AND FOR THE
ENTIRE FORECAST AREA ON WEDNESDAY...BUT NOT EXPECTING MUCH AS
FORCING LIMITED AT BEST.
MORE CLOUDS AND SHOWERS WEDNESDAY NIGHT AS A COLD FRONT MOVES IN
FROM THE WEST. SHOWERS ASSOCIATED WITH THIS SYSTEM WILL PUSH EAST OF
THE FORECAST AREA AFTER MIDNIGHT BUT ABUNDANT LOW LEVEL MOISTURE
WILL LINGER BEHIND THE FRONT AND IT WILL LIKELY TAKE MUCH OF THE
DAY THURSDAY TO PRODUCE A FEW SUNNY BREAKS IN AREAS DOWNWIND OF
THE MOUNTAINS.
QUICK SHOT OF UPPER LEVEL RIDGING THURSDAY NIGHT AND FRIDAY BUT LOW
LEVEL MOISTURE WILL AGAIN KEEP SKIES MOSTLY CLOUDY THURSDAY NIGHT
INTO FRIDAY WITH SOME SUNNY BREAKS DEVELOPING MAINLY IN INLAND
LOCATIONS FRIDAY AFTERNOON.
COLD FRONT APPROACHING FROM THE WEST FRIDAY AFTERNOON WILL QUICKLY
BLOW THROUGH THE REGION FRIDAY NIGHT WITH A BRIEF ROUND OF SHOWERS
AND POSSIBLY A RUMBLE OF THUNDER. WILL SEE CLEARING SKIES DOWNWIND
OF THE MOUNTAINS BY SATURDAY MORNING AS A WEAK SURFACE RIDGE BUILDS
IN BEHIND THE FRONT. FAIR AMOUNT OF COLD AIR POISED TO THE NORTHWEST
SATURDAY MORNING SO WILL LIKELY SEE DAYTIME HIGHS PEAK DURING THE
LATE MORNING BEFORE DROPPING OFF IN THE AFTERNOON. HIGH PRESSURE
WILL HOLD OVER THE REGION ON SUNDAY WITH TEMPS AVERAGING OUT BELOW
NORMAL AFTER A CHILLY START TO THE DAY.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...OCCASIONAL MVFR TO IFR CONDITIONS IN SHOWERS AND
PATCHY FOG AND LOW CLOUDS OVERNIGHT. HOWEVER...WE THINK THE TREND
WILL BE TO IMPROVE AFTER MIDNIGHT. MVFR IN SHOWERS ON MONDAY IN
THE MORNING...THEN IMPROVEMENT TO VFR IN THE AFTERNOON EXCEPT THE
MOUNTAINS.
LONG TERM...VFR TUESDAY. MVFR/IFR CEILINGS DEVELOPING LATE TUESDAY
NIGHT AND WEDNESDAY AND PERSISTING THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...SCA FOR LATE TONIGHT AND MONDAY FOR THE OCEAN WATERS
FOR G25KT AND SEAS AOA 5 FT. SEAS WILL TAKE A WHILE TO
SUBSIDE...PROBABLY NOT UNTIL SOMETIME MONDAY NIGHT.
LONG TERM...NO PROBLEMS NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 8 PM EDT MONDAY
FOR ANZ150-152-154.
&&
$$
LEGRO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
119 PM EDT SUN SEP 30 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 510 AM EDT SUN SEP 30 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER THE
ERN GREAT LAKES AND A RIDGE UPSTREAM FROM MN TO NEAR JAMES BAY.
SINCE THE LOW HAS EDGED SLIGHTLY TO THE WEST...COOLER AIR AND AN
INCREASE IN LOW LEVEL MOISTURE HAS ALSO PUSHED WESTWARD THROUGH
UPPER MI WITH SOME PATCHY LOW CLOUDS...ESPECIALLY IN LOCATIONS FAVORED
BY NE UPSLOPE FLOW. FARTHER UPSTREAM...A SHRTWV AND NOSE OF A
250-300 JET STREAK WAS MOVING THROUGH SRN ALBERTA. AT THE SFC...A
RIDGE EXTENDED FROM NRN QUEBEC TO THE SOUTHWEST INTO THE NRN GREAT
LAKES.
TODAY...EXPECT ANY LINGERING LOWER CLOUDS TO THIN OUT BY MID TO LATE
MORNING WITH INCREASING DAYTIME HEATING. OTHERWISE...HIGH PRES WILL
CONTINUE TO DOMINATE THE REGION WITH MOSTLY SUNNY SKIES AND LIGHT
ERLY WINDS. WITH LITTLE CHANGE IN THE POSITION OF THE 925-850 MB
THERMAL TROUGH...TEMPS SHOULD BE SIMILAR TO SATURDAY WITH MAX
READINGS IN THE MID TO UPPER 60S INLAND AND AROUND 60 NEAR LAKE
SUPERIOR.
TONIGHT...THE SRN CANADA SHRTWV WILL MOVE THROUGH THE NRN PLAINS AND
WILL HELP NUDGE THE BLOCKY DOWNSTREAM RIDGE/TROUGH TO THE EAST.
HOWEVER...MDLS/ENSEMBLE CONSENSUS SUGGESTS THAT ANY PCPN WITH THE
TROUGH SHOULD REMAIN WEST OF LAKE SUPERIOR. AN INCREASE IN SRLY
WINDS AND SOME MID AND HIGH CLOUDS SHOULD KEEP TEMPS FROM FALLING
OFF AS MUCH. LOOK FOR MIN READINGS FROM THE UPPER 30S TO AROUND 40
INLAND AND CLOSE TO 50 FOR THE GREAT LAKES AND WHERE DOWNSLOPE SSW
FLOW PREVAILS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 510 AM EDT SUN SEP 30 2012
AT 12Z MON THERE WILL BE AN UPPER RIDGE OVER THE CWA...WITH A
SHORTWAVE TROUGH FROM WRN HUDSON BAY TO WRN MN. AHEAD OF THE
SHORTWAVE...A SFC TROUGH WILL BE OVER WRN LAKE SUPERIOR. MODELS NOT
SHOWING MUCH MOISTURE WITH THE SYSTEM...OR MUCH QPF...BUT MOST DO
SHOW SOME LIGHT PRECIP ASSOCIATED WITH A NARROW BAND OF LOW LEVEL
MOISTURE OVER PORTIONS OF THE CWA AS THE SHORTWAVE PASSES MON INTO
MON NIGHT. WILL KEEP SLIGHT CHANCE POPS IN THE FORECAST FOR THIS TIME.
ATTENTION THEN TURNS TO A MUCH STRONGER SYSTEM THAT MODELS SHOW
ENTERING THE NRN PLAINS TUE NIGHT AND STRENGTHENING SOMEWHERE IN THE
REGION AROUND THE CWA THU. MODELS THEN SHOW REINFORCING UPPER ENERGY
AND COLD AIR MOVING IN FRI INTO THE WEEKEND. OVERALL...THE FORECAST
DURING THIS TIME IS VERY UNCERTAIN AND QUITE TRICKY. THERE IS
SUBSTANTIAL RUN TO RUN VARIABILITY WITH MOST MODELS AS WELL AS MODEL
DISAGREEMENT...SO FORECAST CONFIDENCE IS LOW. THE OVERALL IDEA SHOWN
BY MODELS IS THAT THE UPPER TROUGH WILL DEEPEN AND CLOSE OFF
SOMEWHERE IN THE REGION THU...AND THEN MOVE NE TO JAMES BAY OR
QUEBEC FRI. NW LOW LEVEL WINDS AND 850MB TEMPS AS LOW AS -8C BEHIND
THE SYSTEM WOULD BE FAVORABLE FOR LAKE EFFECT RAIN/SNOW FRI INTO
SAT. MODELS HAVE BEEN SHOWING A GENERAL NORTHERLY TREND WITH THE LOW
TRACK...MORE TOWARD THE ECMWF WHICH HAS SHOWN BETTER CONTINUITY. NOW
THE LATEST RUN OF THE GFS (00Z/30) SLOWED THE EVOLUTION OF THE
SYSTEM BY 12-18 HOURS FROM THE PREVIOUS RUN. WITH THE SYSTEM
CURRENTLY S OF THE ALEUTIAN ISLANDS AT AROUND LAT 45N LON 160W IT IS
NOT BEING SAMPLED BY TRADITIONAL UPPER AIR NETWORK...SO HOPEFULLY
CONFIDENCE WILL BE IMPROVED WHEN THE SYSTEM MOVES INTO THE
OBSERVATION NETWORK OF WRN CANADA AROUND 00Z TUE. IT IS IMPORTANT TO
POINT THAT THERE IS A VERY WIDE GAMUT OF POSSIBLE REALITIES
RESULTING FROM DIFFERENT PATHS THIS SYSTEM MAY TAKE. IF THE SYSTEM
GOES MORE S OF THE CWA...SE TO NE GALES AND A WETTER/SNOWIER
FORECAST MAY RESULT. IF THE SYSTEM GOES N OF THE CWA...W GALES AND A
DRIER FORECAST MAY RESULT...WITH THE POSSIBILITY OF THUNDERSTORMS
ALONG THE ATTENDANT COLD FRONT. IF THE SYSTEM GOES OVER THE CWA...A
COMBINATION OF THE PREVIOUS SCENARIOS MAY RESULT. OF COURSE...THERE
IS ALSO THE POSSIBILITY THAT THE SYSTEM ENDS UP BEING SIGNIFICANTLY
WEAKER (OR EVEN STRONGER) THAN WHAT THE MODELS CURRENTLY SHOW. AM
REALLY NOT CERTAIN WHAT WILL HAPPEN...BUT AM LEANING TOWARD THE NRN
TRACK OF THE MORE PERSISTENT ECMWF AND FORECAST PERSISTENCE WITH
THIS SYSTEM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 119 PM EDT SUN SEP 30 2012
EXPECT VFR CONDITIONS THIS FCST PERIOD AT ALL 3 TAF SITES WITH DRY
HIGH PRESSURE DOMINATING. SOME MID AND HIGH CLOUDS WILL APPROACH
WITH A SHORTWAVE LATE TONIGHT INTO MONDAY MORNING. COULD BE SOME
LLWS AT KIWD LATE TONIGHT AND INCLUDED IN THE FORECAST WITH A WEAK
SW LOW LEVEL JET. RAIN SHOULD HOLD OFF UNTIL AFTER THIS FORECAST
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 510 AM EDT SUN SEP 30 2012
HIGH PRESSURE AND A WEAK PRESSURE GRADIENT WILL PERSIST TODAY.
SRLY WINDS WILL INCREASE INTO THE 10 TO 20 KT RANGE TONIGHT AHEAD OF
A TROUGH MOVING TOWARD THE REGION. WINDS WILL VEER TO THE WEST
MONDAY AND THEN TO THE NORTH MONDAY NIGHT BUT SHOULD REMAIN AT OR
BELOW 20 KT. HIGH PRESSURE WILL AGAIN DOMINATE TUESDAY WITH
RELATIVELY LIGHT WINDS. A LOW PRESSURE SYSTEM LIFTING INTO NORTHWEST
ONTARIO WILL PUSH A COLD FRONT THROUGH LAKE SUPERIOR THURSDAY WITH
STRONG WRLY WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
316 PM CDT SUN SEP 30 2012
.SHORT TERM...SFC HIGH HAD DRIFTED OVER NORTHERN LAKE SUPERIOR AS
OF 20Z WITH DRY AIR ENTRENCHED OVER THE FA. SFC WIND WAS TURNING
FROM THE SE TO THE S AHEAD OF AN APPROACHING A COLD FRONT. THIS
FRONT IS EXPECTED TO MOVE THROUGH NORTHEAST MINNESOTA BY MIDNIGHT
AND NW WI BY 12Z MONDAY. EXPECT THIS TO BE A DRY FROPA WHICH IS
SUPPORTED BY FORECAST SOUNDINGS FROM ALL MODELS WHICH ARE DRY
BELOW 10K FT. HAVE ADDED A MENTION OF PATCHY FOG TO THE NEAR
SHORE WATERS FROM TWO HARBORS TO THE TWIN PORTS AND PORT WING WI
AS WELL AS INLAND TO SUW WHICH THE LATEST HI RES MODELS HRRR AND
NARRE AGREE ON THIS DEVELOPMENT.
BEHIND THE FRONT LATER TONIGHT AND MONDAY A NW WIND IS EXPECTED
AND IT WILL HELP USHER IN COOLER AIR. HOWEVER...WITH PLENTY OF SUN
EXPECTED...LOOK FOR MAX TEMPS IN THE 60S TO NEAR 70 NEAR PBH AND
BRD.
THE SFC RIDGE AXIS OVERLAYS THE FA MONDAY NIGHT AND EXPECT
RADIATIONAL COOLING WITH A CLEARING SKY TO PRODUCE MIN TEMPS IN
THE 30S...TO AROUND 45 NEAR PBH. THE WARMER TEMPS NEAR PBH ARE DUE
TO LINGERING CLOUDS.
.LONG TERM...[TUESDAY - SATURDAY]...
SNOW IS APPEARING MORE AND MORE LIKELY FOR LATER THIS WEEK. THE
EXPECTED TREND IS FOR WARMER THAN NORMAL WEATHER ON TUESDAY AND
WEDNESDAY TO COME TO AN END BY THURSDAY WHEN A LOW PRESSURE SYSTEM
MOVES ACROSS SOUTHERN MINNESOTA AND NORTHERN WISCONSIN WEDNESDAY
NIGHT AND THURSDAY. THE SYSTEM...WHICH THE GFS AND ECMWF ARE IN
PRETTY GOOD AGREEMENT WITH...WILL USHER IN RAIN AND MUCH COLDER
WEATHER FOR THURSDAY. THE PCPN COULD TRANSITION TO SNOW OR A
RAIN/SNOW MIXTURE THURSDAY NIGHT. PERIODS OF RAIN AND SNOW COULD
CONTINUE INTO THE WEEKEND AS THE COLD WEATHER STICKS AROUND IN THE
WAKE OF THE SYSTEM. IT IS UNCLEAR AT THIS POINT WHETHER THE SNOW
WILL HAPPEN...BUT IT IS LOOKING MORE AND MORE LIKELY...ESPECIALLY
FOR THURSDAY NIGHT AND FRIDAY NIGHT. DO NOT WANT TO MAKE ANY GUESSES
ABOUT ACCUMULATION AT THIS POINT SINCE THE SYSTEM IS STILL FAR OUT.
AT THIS POINT...DID NOT FORECAST ANY PERIODS OF PURE SNOW...BUT SOME
PERIODS OF A RAIN/SNOW MIXTURE.
&&
.AVIATION.../18Z TAF ISSUANCE/
VFR CONDITIONS WILL LIKELY CONTINUE ACROSS NE MINNESOTA AND NW
WISCONSIN THROUGH MONDAY MORNING. THE LIGHT SOUTHERLY WINDS WILL
SWITCH TO NORTHWESTERLY TONIGHT WITH THE PASSAGE OF A COLD
FRONT...AND THE WINDS WILL INCREASE LATE TOMORROW MORNING. THERE
MAY BE FOG SOUTH OF KDLH...BUT AT THIS TIME...DO NOT THINK IT WILL
AFFECT THE TERMINAL. THERE MAY BE ISOLATED LIGHT RAIN SHOWERS
TOMORROW MORNING NEAR KDLH AND KHIB.
&&
.POINT TEMPS/POPS...
DLH 45 65 39 63 / 10 10 0 0
INL 46 64 33 66 / 10 10 0 0
BRD 51 68 35 70 / 10 10 0 0
HYR 43 66 39 68 / 10 10 10 0
ASX 44 67 39 64 / 10 10 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM/AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
356 PM CDT SUN SEP 30 2012
.SHORT TERM...THROUGH LATE MONDAY AFTERNOON. THERE ARE TWO
PRIMARY ISSUES AT HAND DURING THE NEXT 24 HOURS...THE FIRST BEING
A POSSIBLE BUT STILL FAIRLY UNCERTAIN RISK FOR A FEW STRONG
THUNDERSTORMS ACROSS THE FAR WESTERN CWA LATE THIS AFTERNOON INTO
THIS EVENING...AND THE SECOND MAIN ISSUE BEING ELEVATED TO NEAR-
CRITICAL FIRE DANGER ON MONDAY AFTERNOON. ALSO OF CONCERN IS
TRYING TO FIGURE OUT HOW MUCH POST-FRONTAL RAIN WILL DEVELOP
MAINLY DURING THE MORNING HOURS MONDAY. FOR ALL FIRE WEATHER
DISCUSSION PLEASE SEE THE SEPARATE SECTION BELOW.
20Z OBJECTIVE SURFACE ANALYSIS INDICATES A NORTH-SOUTH TROUGH AXIS
EXTENDING FROM NORTH CENTRAL NEB TO NORTHWEST KS...SEPARATING A
LIGHT/VARIABLE TO LIGHT/SOUTHERLY WIND REGIME TO THE EAST FROM A
STRONGER NORTHERLY COMPONENT TO THE WEST. WITHIN AND NEAR THE
IMMEDIATE TROUGH AXIS...INCLUDING MAINLY THE WESTERN 1/4 OF THE
CWA...SURFACE DEWPOINTS HAVE INCREASED TODAY BETWEEN THE MID 40S
AND MID 50S...AND THERE ARE EVEN NOW SIGNS OF A LOW LEVEL CUMULUS
FIELD STARTING TO SHOW ITS HAND. MEANWHILE...ACROSS THE MAJORITY
OF THE CENTRAL/EASTERN CWA...DEWPOINTS HAVE AGAIN DONE THEIR
SEEMINGLY DAILY CRASH WELL INTO THE 30S IN MOST AREAS...ONCE
AGAIN BELOW FORECAST VALUES. ACTUAL HIGH TEMPS ARE WORKING OUT
PRETTY WELL...WITH NEARLY ALL AREAS WITHIN A FEW DEGREES OF 80.
OTHER THAN THE NEWLY DEVELOPED CUMULUS FIELD IN PARTS OF THE
WEST...VISIBLE SATELLITE SHOWS THAT MOST OF THE THICKER HIGH
CIRRUS FROM EARLIER TODAY HAS VACATED EAST OF THE CWA...WHILE A
FEW LEGITIMATE SHOWERS/NEWLY DEVELOPED THUNDERSTORMS ARE ALREADY
OCCURRING BOTH SOUTHWEST AND NORTHWEST OF THE CWA IN NORTH CENTRAL
NEB AND NORTHWEST KS. WATER VAPOR SATELLITE IMAGERY AND SHORT TERM
MODEL DATA DEPICTS AN ALMOST DUE NORTHERLY MID LEVEL FLOW OVER THE
CWA...WITH THE PRIMARY SYNOPTIC SCALE LOWS CONSISTING OF A DEEP
CLOSED CIRCULATION OVER THE NORTHEAST STATES...A VERY SLOW MOVING
CLOSED MID LEVEL LOW CENTERED OVER EASTERN OK...AND A PROGRESSIVE
OPEN WAVE AND ASSOCIATED UPPER LEVEL JET STREAK DIPPING OUT OF
SOUTHERN CANADA INTO THE MT/ND/SD REGION.
STARTING WITH THE MOST IMMEDIATE ISSUE OVER THE NEXT 6 HOURS OR
SO...HAVE MAINTAINED 20-30 PERCENT SHOWER/STORM CHANCES LATE THIS
AFTERNOON INTO THIS EVENING FOR AREAS PRIMARILY WEST OF AN ORD-
KEARNEY-PLAINVILLE LINE AND ESPECIALLY DAWSON...GOSPER AND FURNAS
COUNTIES WHICH ARE ABOUT THE ONLY PARTS OF THE CWA WITHIN THE
MOIST AXIS AND RESULTANT INSTABILITY AXIS...WITH 20Z MESOSCALE
ANALYSIS SUGGESTING THAT A NARROW CORRIDOR OF MLCAPE AT LEAST INTO
THE 500-1000 J/KG RANGE IS NOW IN PLACE IN THIS AREA.
MEANWHILE...THE EASTERN HALF TO TWO THIRDS OF THE CWA HAS
ESSENTIALLY NO CONVECTIVE INSTABILITY AT THIS HOUR...AND THIS WILL
NOT CHANGE HEADING INTO THE EVENING HOURS. WITH DEEP LAYER 0-6KM
BULK SHEAR ONLY AVERAGING AROUND 20 KT...AM NOT EXPECTING A
LEGITIMATE SEVERE THREAT WITH THIS EVENT...BUT THERE IS MORE THAN
ENOUGH INSTABILITY TO GET SOME SEMI-ORGANIZED MULTICELL STORMS OR
A FEW QUASI-LINEAR CLUSTERS GOING...WITH SMALL HAIL AND WINDS TO
AROUND 50 MPH VERY POSSIBLE. FOLLOWING THE REFLECTIVITY PROGS OF
THE LATEST HRRR AND ALSO 12Z 4KM-WRF NMM...THERE COULD BE A DECENT
LULL IN SHOWER/STORM ACTIVITY ONCE THE MID EVENING HOURS ARRIVE
AND THE LOW LEVELS START TO STABILIZE A BIT. FOR THE LATE NIGHT
06Z-12Z POP/WEATHER GRIDS...OPTED TO BLANKET A 20 PERCENT CHANCE
OF SHOWERS/ISOLATED THUNDER ACROSS ROUGHLY THE NORTHWEST 2/3 OF
THE CWA INCLUDING THE TRI-CITIES...IN ASSOCIATION WITH INCREASING
SYNOPTIC SCALE FORCING AND A RESULTANT SOUTHWEST-NORTHEAST BAND
OF MID LEVEL SATURATION DEVELOPING AHEAD OF THE PARENT SHORTWAVE
DROPPING SOUTHEAST ACROSS THE DAKOTAS. THERE ARE PLENTY OF
QUESTIONS REGARDING HOW WIDESPREAD THIS LATE NIGHT PRECIPITATION
MIGHT BE...WITH BOTH THE LATEST ECMWF/GFS SUGGESTING IT COULD BE
NARROW BUT FAIRLY SOLID BAND OF MEASURABLE RAIN...WHILE THE NAM IS
MUCH DRIER THROUGH SUNRISE ALONG WITH THE 4KM WRF-NMM. AT ANY
RATE...NOT EXPECTING ANY LATE NIGHT STORMS TO BE ALL THAT STRONG
LET ALONE SEVERE. KEPT LOW TEMPS TONIGHT SIMILAR TO PREVIOUS
FORECAST AND MET/MAV GUIDANCE BLEND...GENERALLY RIGHT AROUND 50.
FOR THE MONDAY DAYTIME HOURS...BY SUNRISE A WELL DEFINED SURFACE
COLD FRONT WILL BE IN THE PROCESS OF CROSSING THROUGH THE
CWA...AND REALLY THE MOST PROMINENT WEATHER FEATURE THROUGH THE
DAY WILL BE THE QUITE BREEZY TO WINDY CONDITIONS IN ITS WAKE...AS
NORTH WINDS AVERAGE 20-25 MPH SUSTAINED THROUGH MOST OF THE DAY
AND GUSTS 30-35 MPH...BUT SHOULD AVERAGE AT LEAST 5 MPH SHORT OF
ADVISORY CRITERIA. AS FOR PRECIP CHANCES DURING THE DAY...AM
STARTING TO WONDER IF THE FORECAST 20 PERCENT CHANCE OF SHOWERS
DURING THE MORNING HOURS ACROSS ROUGHLY THE SOUTHEAST 2/3 OF THE
CWA IS HIGH ENOUGH...AS THE LATEST ECMWF/GFS ARE NOW SHOWING
POTENTIAL FOR A MORE ORGANIZED NARROW BAND OF LIGHT BUT MEASURABLE
RAINFALL PASSING THROUGH FROM NORTHWEST TO SOUTHEAST.
HOWEVER...WITH MOST OF THE SATURATION ABOVE 700MB AM HESITANT TO
GET TOO CARRIED AWAY WITH POPS...ESPECIALLY GIVEN THAT BOTH THE
18Z NAM AND 12Z WRF-NMM SHOW A MUCH MORE HIT AND MISS...LESS
ORGANIZED BAND. STAYED WITH THE THEME FROM PREVIOUS FORECAST...AND
LEFT THIS MORNING PRECIP RISK AS JUST SHOWERS WITH NO THUNDER
MENTION...ALTHOUGH SUPPOSE A FEW ROGUE LIGHTNING STRIKES ARE NOT
OUT OF THE QUESTION. ALSO IN LINE WITH PREVIOUS FORECAST...LEFT
THE AFTERNOON 18Z-00Z PERIOD PRECIP FREE...BUT THERE A FEW HINTS
IN LATEST MODELS THAT A FEW SHOWERS COULD LINGER INTO THE
AFTERNOON PERIOD ACROSS THE FAR EASTERN/SOUTHERN CWA...AND THE
NEXT SHIFTS WILL WANT TO SEE IF MAYBE THIS RAIN MENTION NEEDS
EXTENDED IN TIME A BIT. BY THE MID AFTERNOON HOURS
HOWEVER...CONFIDENCE IS FAIRLY HIGH THAT THE ENTIRE CWA SHOULD BE
RAIN-FREE AND SEEING PLENTY OF SUN...AS THE PARENT MID LEVEL
TROUGH AXIS AND RESULTANT MID LEVEL SATURATION STARTS TO FOCUS
EAST OF THE AREA. TEMP WISE...LOWERED HIGHS 2-3 DEGREES FROM
PREVIOUS IN MOST AREAS...FOLLOWING THE RAW 12Z NAM SOLUTION
CLOSELY AND RANGING FROM LOW 70S NORTHWEST TO UPPER 70S SOUTHEAST.
DID LOWER DEWPOINTS SEVERAL DEGREES ESPECIALLY DURING THE MID-LATE
AFTERNOON WITH WIDESPREAD LOW-MID 30S AND EVEN UPPER 20S
NORTHWEST.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY. SURFACE HIGH PRESSURE
BUILDS SOUTH BEHIND THE COLD FRONTAL BOUNDARY...WITH RIDGE AXIS
SETTLING ACROSS NEBRASKA AND WESTERN KANSAS MONDAY NIGHT. THE RIDGE
DOES WEAKEN...HOWEVER IN THE COOLER...DRY AIRMASS WITH LIGHT WINDS
AND GOOD RADIATIONAL CONDITIONS...WE ARE LOOKING AT THE POTENTIAL
FOR SOME CHILLY OVERNIGHT LOW TEMPERATURES. SFC DPS DROP TO THE 20S
AND LOWER 30S AND ITS LOOKING LIKE OVERNIGHT LOWS WILL AGAIN FALL
INTO THE TEMPERATURE RANGE FAVORABLE FOR FROST...IN THE LOW/MID
30S. THESE LOCATIONS HAVE ALREADY EXPERIENCED SIMILAR LOW TEMPS
THIS SEASON OR COLDER AND WILL NOT MENTION FROST...BUT WILL NEED TO
MONITOR FOR FREEZE CONDITIONS FOR LOCATIONS THAT HAVE YET TO FREEZE.
THE SURFACE RIDGE AXIS WASHES OUT/SHIFTS EAST ON TUESDAY WITH RETURN
FLOW SETTING UP AHEAD OF A DEEPENING SURFACE LOW IN
MANITOBA...ASSOCIATED WITH UPSTREAM TROUGH ALONG THE US/CANADIAN
BORDER. SHORTWAVE RIDGING NOSES ONTO THE CENTRAL PLAINS IN BETWEEN
UPPER LOW TO THE SOUTHEAST AND TROUGH ENTERING THE NORTHERN
ROCKIES. TEMPERATURES WILL MODERATE TUESDAY...BUT WITH COOL START
TO THE DAY AND LESS MIXING WILL AIM FOR HIGHS IN THE MID 70S VS NEAR
80F.
WEDNESDAY IS REALLY ONE OF THE TRICKIER DAYS DUE TO TIMING OF COLD
FRONTAL PASSAGE. UPPER LOW PRESSURE TROUGH REACHES THE NORTHERN
PLAINS AND ROCKIES WITH THE ASSOCIATED COLD FRONT MOVING INTO
WESTERN NEBRASKA BY 12Z WEDNESDAY. THERE ARE IMPRESSIVE PRESSURE
RISES OF 10+MB PROGGED BEHIND THE FRONT IN THE NEB PANHANDLE. IN
GENERAL MODELS HAVE TRENDED FASTER WITH FRONTAL PASSAGE WITH THE
BOUNDARY THROUGH AT LEAST OUR WESTERN THIRD CWA...IF NOT HALF OF THE
CWA BY 18Z. WITH THE FASTER TREND...HAVE SHARPENED TEMP GRADIENT
NW/SE WITH AND LOWERED HIGHS IN OUR NORTHWEST TO THE LOW 70S. IF
FRONT TRENDS ANY FASTER...COULD SEE TEMPS FALLING DURING THE
AFTERNOON AND OUR NW ZONES MAY NOT REACH 70F. THIS BEING SAID...IF
FRONT IS SLOWER AND MORE IN LINE WITH ECMWF VS NAM/GFS...TEMPS MAY
BE WARMER THAN CURRENT FORECAST.
PCPN CHCS INCREASE WEDNESDAY NIGHT IN INCREASING UPPER DYNAMICS AS
TROUGH CROSSES THE CENTRAL PLAINS. THE 12Z GFS AND GEM ARE DEEPER
WITH TROUGH THAN THE MORE PROGRESSIVE 00Z AND 12Z RUNS OF THE
ECMWF. HAVE CONCERNS THAT ECMWF IS TOO PROGRESSIVE WITH
SYSTEM...AND GFS/GFS ENSEMBLE LOOKS TO BE DECENT COMPROMISE BETWEEN
ECMWF AND GEM SOLUTIONS. IF THE DEEPER TROUGH SOLUTIONS VERIFY WE
COULD SEE A DECENT CHC FOR RAIN...BUT WOULD LIKE TO SEE MORE
CONSISTENCY BEFORE RAISING POPS. THE TROUGH AXIS DEPARTS THURSDAY
MORNING...WITH PCPN ENDING W/E.
THEREAFTER FOR THE REMAINDER OF THE WORKWEEK AND INTO NEXT
WEEKEND...PATTERN WILL BE INFLUENCED BY UPPER TROUGH ENCOMPASSING
MUCH OF THE INTERIOR CONUS. TEMPERATURES WILL REMAIN BELOW NORMAL
AND THERE WILL BE SOME HIT OR MISS CHCS FOR RAIN SHOWERS AS ENERGY
TRANSLATES THRU FLOW.
&&
.FIRE WEATHER...ALTHOUGH FIRE WEATHER CONDITIONS ARE CURRENTLY
FORECAST TO FALL JUST A BIT SHORT OF CRITICAL THRESHOLDS ON
MONDAY AFTERNOON THANKS TO RELATIVE HUMIDITY VALUES HOLDING AT
LEAST SLIGHTLY ABOVE 20 PERCENT...THE CURRENTLY FORECAST
COMBINATION OF SUSTAINED NORTHERLY WINDS AROUND 25 MPH/GUSTS
30-35 MPH AND RELATIVE HUMIDITY VALUES FALLING INTO THE 22-26
PERCENT RANGE FOR A FEW HOURS IS MORE THAN ENOUGH TO WARRANT THE
CONTINUATION OF ELEVATED TO NEAR-CRITICAL FIRE DANGER WORDING IN
THE HAZARDOUS WEATHER OUTLOOK. BASED ON RAINFALL TRENDS OVER THE
PAST MONTH AND OFFICIAL FIRE GROWTH FUEL STATUS FROM FIRE
MANAGERS...THE NEBRASKA COUNTIES WILL GENERALLY BE UNDER THE GUN
MORE SO THAN KS. ONE FACTOR THAT MIGHT BE JUST ENOUGH TO SPARE US
FROM DROPPING TO 20 PERCENT OR LOWER RELATIVE HUMIDITY IS THAT
HIGH TEMPS WERE LOWERED 2-3 DEGREES FROM PREVIOUS FORECAST.
HOWEVER...DEWPOINTS WERE ALSO DROPPED AT LEAST 5 DEGREES FROM
PREVIOUS FORECAST IN MOST AREAS DURING THE KEY MID-LATE AFTERNOON
HOURS...NOW ADVERTISED BETWEEN THE UPPER 20S AND MID 30S IN MOST
COUNTIES. NEXT FEW SHIFTS WILL HAVE TO KEEP A CLOSE EYE ON THESE
DEWPOINT/RH TRENDS...AS ONLY A SLIGHT DOWNWARD ADJUSTMENT COULD
REQUIRE HEADLINE ISSUANCE FOR AT LEAST A SMALL PART OF MAINLY THE
WESTERN CWA. LOOKING BEYOND MONDAY...WILL ALSO HAVE TO KEEP AN EYE
ON WEDNESDAY AFTERNOON FOR OUR NEXT POTENTIALLY NEAR-CRITICAL FIRE
DANGER SITUATION...AS NORTHERLY WINDS INCREASE AGAIN BEHIND THE
NEXT COLD FRONT.
&&
.PREV DISCUSSION... /ISSUED 1215 PM CDT SUN SEP 30 2012/
AVIATION...18Z KGRI TAF. VFR CEILING AND VISIBILITY ARE
ANTICIPATED THROUGH THE NEXT 24 HOURS...WITH ANY CEILING LATER
TONIGHT INTO MONDAY MORNING LIKELY AVERAGING ABOVE 10 THOUSAND
FEET. AS A RESULT...THE MAIN CONCERN WILL BE THE PASSAGE OF A
FAIRLY WELL-DEFINED COLD FRONT DURING THE LATTER HALF OF THE
PERIOD. FOR THE REST OF TODAY INTO THIS EVENING...FAIRLY LIGHT
SOUTHERLY BREEZES WILL PREVAIL WITH ANY THUNDERSTORM ACTIVITY
LIKELY FOCUSING AT LEAST 60 MILES WEST OF KGRI. HAVE AIMED THE
INITIAL SWITCH TO STEADY NORTHERLY BREEZES BEHIND THE COLD FRONT
AT 10Z FOR NOW...WITH SPEEDS PICKING UP CONSIDERABLY AFTER SUNRISE
WITH GUST POTENTIAL TO AT LEAST 27KT FOR THE LAST SEVERAL HOURS OF
THE PERIOD. PRECIPITATION WISE...CONFIDENCE IS NOT HIGH IN THE
TERMINAL SEEING AN ORGANIZED RISK OF SHOWERS OR WEAK STORMS...BUT
DID INTRODUCE A VICINITY SHOWER MENTION DURING THE LAST 8 HOURS TO
SUGGEST THE POSSIBILITY OF HIGH BASED ACTIVITY IN THE AREA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/FIRE WEATHER/AVIATION...PFANNKUCH
LONG TERM...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1215 PM CDT SUN SEP 30 2012
.UPDATE...RECENTLY SHIPPED AN UPDATE FOR THE AFTERNOON HOURS
THROUGH 00Z. PRIMARY CHANGE FROM PREVIOUS FORECAST WAS TO DELAY
ALL MENTION OF SHOWERS/STORMS UNTIL 21Z...AND EVEN THEN KEPT THESE
20-30 PERCENT CHANCES MAINLY WEST OF AN ORD-KEARNEY-PLAINVILLE
LINE...WITH ESSENTIALLY ZERO RISK OF PRECIP FOR AREAS NEAR AND
EAST OF HIGHWAY 281 THROUGH SUNSET. LATEST MODELS HAVEN/T CHANGED
THE OVERALL THINKING MUCH...AS MID-LATE AFTERNOON STORM
DEVELOPMENT IS STILL SLATED TO FOCUS VERY NEAR A ROUGHLY NORTH-
SOUTH SURFACE TROUGH AXIS ALIGNED FROM NORTH CENTRAL NEB INTO
NORTHWEST KS...WITH DAWSON...GOSPER AND FURNAS COUNTIES IN THE CWA
MOST FAVORED TO SEE THIS CONVECTION. LATEST HOURLY MESOSCALE
ANALYSIS IS ALREADY SUGGESTING AT LEAST 500 J/KG OF LOW LEVEL
MIXED LAYER CAPE IS ALREADY POOLING JUST AHEAD OF THIS BOUNDARY
ACROSS THE FAR WESTERN CWA...BUT LIKELY WITH ENOUGH CINH TO HOLD
THE MAIN SHOW OFF FOR SEVERAL MORE HOURS. THAT BEING SAID...A
SMALL...ROGUE STORM THAT FORMED AROUND SUNRISE HAS ALREADY BARELY
SKIRTED WEST OF THE CWA THIS MORNING AS IT TRACKED FROM NORTH OF
MCCOOK TO ITS CURRENT LOCATION SOUTH OF HILL CITY. STILL NOT
THINKING MUCH SEVERE THREAT THIS AFTERNOON/EVENING WITH DEEP LAYER
SHEAR ONLY AVERAGING AROUND 20KT...BUT SMALL HAIL TO DIME/PENNY
SIZE AND WIND GUSTS TO AROUND 50 MPH GIVEN THE INVERTED-V LOOK TO
SOUNDINGS ARE CERTAINLY FAIR GAME IF THINGS EVENTUALLY DO GET
GOING. BECAUSE THERE ARE STILL QUESTIONS REGARDING HOW WIDESPREAD
THIS STORM COVERAGE MIGHT BE...HAVE KEPT POPS CAPPED AT ONLY 30
PERCENT/SCATTERED COVERAGE FOR NOW. ANY INDIVIDUAL STORMS OR STORM
CLUSTERS WILL DRIFT ALMOST DUE SOUTH AND SHOW VERY LITTLE IF ANY
EASTWARD PROPAGATION. AS FOR AFTERNOON HIGH TEMPS...MADE LITTLE IF
ANY CHANGE TO PREVIOUS FORECAST...WITH MOST ALL AREAS STILL
LOOKING AT 79-82.
&&
.AVIATION...18Z KGRI TAF. VFR CEILING AND VISIBILITY ARE
ANTICIPATED THROUGH THE NEXT 24 HOURS...WITH ANY CEILING LATER
TONIGHT INTO MONDAY MORNING LIKELY AVERAGING ABOVE 10 THOUSAND
FEET. AS A RESULT...THE MAIN CONCERN WILL BE THE PASSAGE OF A
FAIRLY WELL-DEFINED COLD FRONT DURING THE LATTER HALF OF THE
PERIOD. FOR THE REST OF TODAY INTO THIS EVENING...FAIRLY LIGHT
SOUTHERLY BREEZES WILL PREVAIL WITH ANY THUNDERSTORM ACTIVITY
LIKELY FOCUSING AT LEAST 60 MILES WEST OF KGRI. HAVE AIMED THE
INITIAL SWITCH TO STEADY NORTHERLY BREEZES BEHIND THE COLD FRONT AT
10Z FOR NOW...WITH SPEEDS PICKING UP CONSIDERABLY AFTER SUNRISE
WITH GUST POTENTIAL TO AT LEAST 27KT FOR THE LAST SEVERAL HOURS OF
THE PERIOD. PRECIPITATION WISE...CONFIDENCE IS NOT HIGH IN THE
TERMINAL SEEING AN ORGANIZED RISK OF SHOWERS OR WEAK STORMS...BUT
DID INTRODUCE A VICINITY SHOWER MENTION DURING THE LAST 8 HOURS TO
SUGGEST THE POSSIBILITY OF HIGH BASED ACTIVITY IN THE AREA.
&&
.PREV DISCUSSION... /ISSUED 406 AM CDT SUN SEP 30 2012/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. MAIN FORECAST CONCERN IS
ISOLATED THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON/EVENING...
FOLLOWED BY THE PASSAGE OF A COLD FRONT SHORTLY THEREAFTER.
WEAK SURFACE HIGH PRESSURE CENTERED NEAR HILL CITY KANSAS THIS
MORNING HAS KEPT WINDS LIGHT...WITH ONLY SOME HIGH CLOUDS SCRAPING
THE SOUTHEAST 1/3 OF THE FORECAST AREA. TEMPERATURES WARMER
IN THE CLOUDY AREAS...AS OPPOSED TO CLOUD FREE REGIONS.
ONE EARLY...ALTHOUGH MINOR CONCERN...MAY BE A BIT OF FOG IN THE FAR
SOUTHWEST/WESTERN FORECAST AREA. LATEST HRRR DATA IS SHYING AWAY
FROM ANY FOG OR LOW CLOUDS IN OUR FORECAST AREA...OPTING INSTEAD
JUST TO THE WEST WHERE SOUTHERLY FLOW HAS ALLOWED FOR A LITTLE
BETTER MOISTURE RETURN. MOST LIKELY THIS STUFF WOULDN/T GET GOING
UNTIL CLOSE TO SUNRISE...SO ITS A GAME TIME DECISION WHETHER ITS
WORTH EVEN BEING PART OF THE FORECAST. RIGHT NOW...ITS NOT LOOKING
TO LIKELY TO FORM.
THE MAIN STORY REST OF THE DAY IS WHETHER THE WESTERN PART OF THE
FORECAST CAN SHARE IN SOME ISOLATED SHOWERS/THUNDERSTORMS LATE THIS
AFTERNOON AND EVENING. WEAK SURFACE CONVERGENCE ALONG A BOUNDARY
STARTS TO PUSHING THE FAR WESTERN SECTION OF THE FORECAST ABOUT MID
AFTERNOON. THIS COINCIDES WITH NARROW AXIS OF MOISTURE AND SURFACE
INSTABILITY BRIEFLY ABOVE 1000 J/KG. STEEP MID LEVEL LAPSE RATES ALSO
SET UP. THERE LIKELY WILL BE SOME HIGH BASED SHOWERS/ISOLATED
THUNDERSTORMS FORMING JUST TO THE WEST OF THE FORECAST AREA AROUND
3-4 PM...AND THEN GRADUALLY MIGRATE EAST. HAVE CONTINUED WITH THE
20-30% CHANCE OF RAIN...NOT SO MUCH FOR UNCERTAINTY ON CONVECTIVE
ACTIVITY...BUT KEPT THINGS ON THE LOW SIDE WITH LARGE LOW
LEVEL DEWPOINT DEPRESSIONS AND CLASSIC INVERTED V SOUNDINGS. BOTH
SUGGEST LIMITED RAINFALL...BUT SOME WIND GUST POTENTIAL TO NEAR
SEVERE LEVELS. HAVE INCLUDED SOME CHANCE INTO THE EARLY EVENING
AS FAR EAST AS HIGHWAY 281...ALTHOUGH THAT MAY WELL BE STRETCHING
IT WITH STORM MOTIONS PROBABLY AROUND 10KTS OR SO. LATEST MODELS
HAVE FAVORED A LITTLE FURTHER WEST PROFILE...SO KEPT THE BEST
SHOT FOR RAIN THERE.
WELL...ONCE THAT STUFF WRAPS BY LATE EVENING...ATTENTION TURNS
TO ONCOMING COLD FRONT LATE TONIGHT AND EARLY MONDAY. PRETTY STRONG
PRESSURE RISES AS THE FRONT PASSES...SO EXPECT THE WIND TO PICK UP
PRETTY STEADY BY LATE TONIGHT. GOOD MOMENTUM TRANSFER WILL CONTINUE
ALL DAY MONDAY WITH NEARLY UNIDIRECTIONAL FLOW GIVING US THE FIRST
BREEZY/WINDY DAY...SINCE THE LAST COLD FRONT A FEW DAYS AGO. MODELS
TRY TO SQUEEZE OUT SOME LIGHT SHOWERS...PROBABLY SPRINKLES. NONE THE
LESS...HAVE WORKED IN TANDEM WITH OTHER OFFICES TO INCLUDE A SLIGHT
CHANCE OF LIGHT SHOWERS MONDAY MORNING...BEFORE SUNSHINE TAKES OVER
LATER. TEMPERATURES WILL NOT ONLY FEEL COOLER DUE TO THE NORTH
WIND...BUT ACTUALLY BE COOLER DURING THE DAY MONDAY.
NOT MUCH ELSE TO WORRY ABOUT MONDAY NIGHT THROUGH TUESDAY NIGHT...
WITH A COOL NIGHT MONDAY NIGHT...GIVING WAY TO A REALLY NICE AND
MILD DAY TUESDAY WITH SUNSHINE AND LIGHT WINDS.
LONG TERM...12Z WEDNESDAY THROUGH SATURDAY. A COLD FRONT
PROGGED TO TRANSITION THROUGH THE REGION WEDNESDAY NIGHT INTO
THURSDAY WILL PROVE TO BE THE MOST CHALLENGING ASPECT OF THE
EXTENDED FORECAST. CHALLENGES WILL RESULT IN PRECIPITATION
TIMING/COVERAGE AND TEMPERATURES BOTH AHEAD AND BEHIND THE COLD
FRONT. PRECIP CHANCES WILL ALSO BE REALIZED TOWARDS THE END OF THE
LONG TERM.
A COLD FRONT WILL EXTEND DOWN INTO THE CENTRAL PLAINS ON THURSDAY
FROM FROM AN ASSOCIATED UPPER LEVEL TROUGH FORECAST TO PASS
THROUGH THE NORTHERN PLAINS. RETURN FLOW IN THE LOWER LEVELS AHEAD
OF THIS FRONTAL BOUNDARY SHOULD ADVECT ENOUGH MOISTURE INTO THE
CENTRAL PLAINS TO HELP AID IN THE DEVELOPMENT OF SOME STRATIFORM
RAIN ACROSS THE OUTLOOK AREA. FORECAST SOUNDINGS SUGGEST A MOIST
ATMOSPHERIC PROFILE BEGINNING AROUND MIDNIGHT ON WEDNESDAY AND
CONTINUING THROUGH THE MORNING HOURS OF THURSDAY. PRECIPITATION
TIMING WILL RELY SOLELY ON THE TIMING OF THE COLD FRONT...BUT
CURRENT ANALYSIS LEADS TO PRECIP BEGINNING LATE WEDNESDAY NIGHT AND
CONTINUING THROUGH THURSDAY MORNING BEHIND THE COLD FRONT. NO SEVERE
WEATHER IS ANTICIPATED.
THE BIGGEST CHANGE IN THE FORECAST WAS WEDNESDAY HIGH
TEMPERATURES...WHICH WILL BE NEAR 80 DEGREES AHEAD OF THE FRONT FOR
MOST OF THE OUTLOOK AREA. THIS CHANGE IS MAINLY DUE TO THE TIMING OF
THE FRONT BEING A LITTLE SLOWER THAN PREVIOUSLY FORECAST.
FURTHERMORE...850MB TEMPS ALSO SUGGEST HIGHER TEMPERATURES THAN THE
OUTPUT FROM ALLBLEND. THURSDAY HIGH TEMPERATURES AND FRIDAY MORNING
LOW TEMPERATURES HAVE BEEN RATHER TRICKY WITH THE PASSAGE OF THE
FRONTAL BOUNDARY OVER THE LAST COUPLE OF DAYS. SEEMS AS THOUGH THE
MODELS MAY HAVE FINALLY SETTLED ON A SOLUTION. THE PAST SEVERAL DAYS
HAVE SHOWN A GENERAL DECREASE IN TEMPERATURES ACROSS THE CWA FOR
THURSDAY HIGH TEMPERATURES AND THE OVERNIGHT LOWS...BUT TEMPERATURES
ARE NOW NEARLY CONSISTENT WITH THE PREVIOUS FORECAST. THURSDAY WILL
BE BELOW NORMAL FOR HIGHS AS UPPER 50S AND LOWER 60S ARE FORECAST.
IN FACT...THE REST OF THE LONG TERM IS FORECAST TO EXPERIENCE BELOW
NORMAL TEMPERATURES FOR THIS TIME OF YEAR. THURSDAY NIGHT LOW
TEMPERATURES ARE STILL FLIRTING WITH FROST POTENTIAL. WILL NEED TO
MONITOR THIS OVER THE NEXT COUPLE OF DAYS. A FROST ADVISORY
MIGHT HAVE SOME CREDIBILITY ACROSS NORTHERN PARTS OF THE CWA NEXT
WEEK.
THERE WILL BE A CHANCE FOR PRECIPITATION FRIDAY NIGHT AND INTO
SATURDAY AS ANOTHER CONVERGENCE ZONE SETS UP OVER THE CENTRAL PLAINS
WITH FORECAST SOUNDINGS SUGGESTING A MOIST ATMOSPHERIC PROFILE.
AGAIN...SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/AVIATION...PFANNKUCH
SHORT TERM...NOAA/NWS/MORITZ
LONG TERM...GUERRERO
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
348 PM EDT SUN SEP 30 2012
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL CROSS THE AREA TONIGHT WITH WIDESPREAD
LIGHT TO MODERATE RAINFALL EXPECTED. THE RAIN TAPERS TO SHOWERS AND
ENDS BY MONDAY EVENING AS HIGH PRESSURE BRIEFLY BUILDS INTO THE
REGION. GENERALLY DRY AND MILDER WEATHER IS EXPECTED FOR
TUESDAY...BEFORE THE THREAT OF SHOWERS INCREASES AGAIN BY MID WEEK
WITH THE APPROACH OF THE NEXT LOW PRESSURE SYSTEM.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 300 PM EDT SUNDAY...COMPLEX FORECAST TAKING SHAPE FOR TONIGHT
AS UPPER LEVEL LOW PRESSURE DRIFTS ATOP THE AREA WITH WIDESPREAD
RAINFALL. HI-RES RAP/HRRR DATA HAS CAPTURED CURRENT SCENARIO OUT
THROUGH THE NEXT 8 HOURS QUITE WELL AND WILL LEAN TOWARD ITS SOLN
ACCORDINGLY. AS SOUTHERLY FLOW HAS BECOME ESTABLISHED EAST OF THE
UPPER LOW CENTER TODAY...A DEEP WRN ATLANTIC/SUBTROPICAL MOISTURE
PLUME AND ASSOCIATED RAFL HAS EVOLVED SSE-NNW ACROSS NEW
ENGLAND...CAPTURED NICELY BY AMSU/SSM-I BLENDED TPW. THIS RAIN
BAND WILL CONTINUE TO PIVOT BACK TO THE NORTH AND WEST OVER OUR
CENTRAL AND NRN COUNTIES THIS EVENING INTO TONIGHT...EVOLVING INTO
A PRIMARY DEFORMATION ZONE AS THE UPPER LOW CENTER EDGES EAST. NOT
THE CLASSIC DEFORMATION SIGNATURE HOWEVER AS LOW LEVEL FLOW TRENDS
WEST TO SOUTHWESTERLY AFTER MIDNIGHT AND PCPN SHIELD BEGINS TO
TAKE ON A MORE OROGRAPHIC CHARACTER. NONETHELESS A WIDESPREAD
RAINFALL EVENT STILL ON TRACK FOR MUCH OF OUR CENTRAL AND NORTHERN
COUNTIES OVERNIGHT AND WILL CONTINUE CATEGORICAL POPS IN THESE
AREAS. SOUTHERN COUNTIES WILL BE SLIGHTLY REMOVED AND JUST SOUTH
OF THE PRIMARY RAIN BAND PIVOT POINT...AND WILL OFFER SLIGHTLY
LOWER POPS IN THESE AREAS...BUT ALL LOCATIONS TO AT LEAST SEE A
MEASUREABLE RAINFALL WITH HIGHEST AMOUNTS NORTH. LOWS AGAIN VERY
UNIFORM GIVEN LIGHT WINDS AND LACK OF LOW LEVEL THERMAL
ADVECTION...GENERALLY U40S TO L50S. PATCHY FOG ALSO A GOOD BET
HERE AND THERE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM EDT SUNDAY...AS UPPER LOW DRIFTS NORTHEAST AND SLOWLY
AWAY FROM THE REGION ON MONDAY...DEFORMATION/OROGRAPHICALLY FORCED
PCPN SHIELD SHOULD SLOWLY ERODE/WEAKEN OVER TIME...WITH MOST AREAS
OUTSIDE OF THE NORTHERN MTNS TRENDING DRY BY THE AFTERNOON HOURS.
SOUTH TO SOUTHWESTERLY FLOW TO CONTINUE WITH CONDITIONS GUSTY AT
TIMES BY AFTERNOON. HIGHS A TAD MILDER AS 925-850 THERMAL PROFILES
GRADUALLY MODERATE...GENERALLY IN THE 58 TO 65 RANGE WITH MILDEST
READINGS WEST.
FAIR AND DRY WEATHER THEN RETURNS BY MONDAY NIGHT INTO MUCH OF
TUESDAY AS SHORTWAVE RIDGING BUILDS INTO THE NORTHEAST FROM THE
MID-ATLANTIC/OHIO VALLEY STATES. GENERALLY CLR TO PC CONDS EXPECTED
WITH MILDER NEAR SEASONABLE TEMPERATURES EXPECTED. CLOUDS AND A
LOWER END THREAT OF SHOWERS WILL BE ON THE INCREASE BY TUESDAY
EVENING INTO TUESDAY NIGHT HOWEVER AS NEXT UPPER SHORTWAVE TROUGH
OPENS UP AND LIFTS NORTHEAST OUT OF THE MISS/TENN VALLEY REGION.
LATEST MODEL TRENDS HAVE SHIFTED CONSIDERABLY FURTHER WEST WITH THIS
FEATURE ON THE 12Z MODEL SUITE HOWEVER...DEPICTING MILDER SOUTHERLY
FLOW AND A MORE SCATTERED NATURE TO THE SHOWER ACTIVITY AS MEAN H5
BERMUDA RIDGING STRENGTHENS AND SHIFTS WEST TO NEAR 30N/-70W. WITH
SUCH BROAD CONSENSUS...HARD TO IGNORE THIS POTENTIAL SHIFT IN
THINKING...AND HAVE TRENDED POPS BACK SOMEWHAT INTO THE 30/40%
RANGE ALONG WITH RAISING MIN TEMPS BY 2-4 DEG ACROSS THE BOARD.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 PM EDT SUNDAY...FCST FOCUS WL BE TIMING OF RAIN CHCS AND
TEMPS IN ACTIVE SW FLW ALOFT FOR DAYS 4 THRU 7. MID/UPPER LVL
RIDGE IN THE CENTRAL ATLANTIC WL RETROGRADE BACK WEST TWD THE EAST
COAST BY MID WEEK...WHICH WL RESULT IN BUILDING HGHTS AND A
BLOCKING TYPE PATTERN. THIS WL ALSO DEFLECT MID/UPPER LVL S/W
ENERGY AND ASSOCIATED MOISTURE FROM THE MS VALLEY INTO THE GREAT
LAKES AREA...WELL WEST OF OUR CWA...PLACING OUR REGION IN THE WARM
SECTOR FOR WEDS/THURS. PROGGED 85H TEMPS WARM BTWN 12C AND 14C
WITH 925MB TEMPS NEAR 10C...SUPPORT HIGHS WELL INTO THE 70S.
HOWEVER...CLOUDS MAY LIMIT SFC HEATING SOME ACRS MTNS/NEK.
GEM/ECMWF/GEM ALL SHOW GOOD 850 TO 500 MB RH MOVING ACRS OUR
CWA...BUT BEST PVA ASSOCIATED WITH 5H VORT IS LOCATED TO OUR
WEST...THEREFORE WL KEEP POPS BTWN 30 AND 50% ATTM. GIVEN THE
PRIMARY STORM TRACK TO OUR WEST WOULD ANTICIPATE A HIGH POP LOW
QPF EVENT FOR THIS SYSTEM. AN INCREASE IN HUMIDITY IS LIKLEY WITH
DWPTS IN THE 50S TO NEAR 60F...WHICH WL KEEP OVERNIGHT LOWS MUCH
ABOVE NORMAL FOR WEDS NIGHT AND THURS NIGHT. BY LATE WEEK INTO
NEXT WEEKEND MID/UPPER LVL RIDGE SLOWLY BREAKS DOWN...AS SFC COLD
FRNT APPROACHES FA. STILL SOME UNCERTAINTY TO TIMING OF SYSTEM AND
IF SFC LOW PRES DEVELOPS ALONG THE FRNT. GIVEN THE LARGE BLOCKING
PATTERN IN PLACE...WL TREND TWD THE SLOWER ECMWF TIMING OF
SYSTEM...BUT MENTION SCHC TO LOW CHC POPS THRU THE PERIODS. LOOKS
LIKE THE BEST CAA AND COOLER TEMPS ARRIVE ON SUNDAY INTO
MONDAY...WITH VALUES BACK CLOSER TO NORMAL.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...DEEP CLOSED 5H/7H CYCLONIC CIRCULATION ACRS
NORTHERN PA WL CONT TO ADVECT PLENTY OF MOISTURE ACRS OUR TAF
SITES THRU TONIGHT. OVERALL IFR CONDITIONS WL CONT AT SLK/MSS WITH
MAINLY IFR AT BTV/MPV/RUT...AND MVFR AT PBG THRU THIS AFTN/EVENING. VAD
PROFILE SHOWS NORTHERLY FLW DOWN THE CPV...HELPING TO ENHANCE LLVL
MOISTURE CONVERGENCE AT BTV WITH CRNT RADAR SHOWING A BAND OF
MODERATE RAIN ROTATING INTO OUR NORTHERN/CENTRAL TAF SITES. OBS
INDICATING IFR CONDITIONS WITH VIS BTWN 1-3SM AND CIGS BROKEN TO
OVERCAST AT 400 TO 800 FT. THIS BAND OF RAIN WL SLOWLY LIFT FROM
SE TO NW ACRS OUR TAF SITES THRU THE REST OF THIS AFTN. THIS
EVENING...BOTH RAP AND NAM SHOW A WIND SHIFT TO THE SW BTWN 03Z
AND 05Z...WHICH WL RESULT IN DOWNSLOPE FLW AND SOME IMPROVING CIGS
AT BTV/PBG. WL MENTION MVFR CONDITIONS. OTHERWISE...ANTICIPATE
MAINLY IFR CIGS TO CONT AT MPV/RUT/SLK/MPV WITH PATCHY DRIZZLE/FOG
REDUCING VIS BTWN 1-3SM AT TIMES. BUFKIT VERTICAL MOISTURE
PROFILES SHOW A SLOW DECREASE IN RH BTWN 13-15Z WITH BETTER
MIXING...RESULTING IN MVFR CONDITIONS AT MOST SITES. SLOWEST SITES
TO CLR WL BE SLK/MPV.
OUTLOOK 18Z MONDAY THROUGH THURSDAY...
WEAK SFC RIDGE WL RESULT IN DRYING ALOFT AND AT THE SFC WITH
MAINLY VFR CONDITIONS AT BTV/MSS/RUT/PBG AND MVFR BECMG VFR AT
MPV/SLK FROM 18Z THRU 18Z WEDS. SOME PATCHY FOG WL BE POSSIBLE AT
SLK/MPV MONDAY NIGHT/TUES MORNING. NEXT SYSTEM ARRIVES WEDS AFTN
INTO THURS WITH MORE SCATTERED SHOWERS AND POTENTIAL PERIODS OF
MVFR CONDITIONS.
&&
.HYDROLOGY...
AS OF 300 PM EDT SUNDAY...WIDESPREAD RAINFALL EXPECTED THIS
EVENING INTO TONIGHT WITH DEFORMATION/WRAP-AROUND PCPN AFFECTING
THE REGION ASSOC WITH PASSG OF UPPER LOW PRESSURE. 24-HR BASIN
TOTALS GENERALLY IN THE 0.50 TO 1.0 INCH RANGE ACROSS CENTRAL AND
NORTHERN WATERSHEDS...AND 0.25 TO 0.50 INCH SOUTH. ONLY MODESTLY
MOIST ANTECEDENT GROUND CONDITIONS AND ONLY SLIGHT TO MODEST RISES
ON AREA RIVERS OF 1-2 FEET EXPECTED AS RUNOFF PEAKS BY MONDAY
AFTERNOON.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...TABER
AVIATION...TABER
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
300 PM EDT SUN SEP 30 2012
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL CROSS THE AREA TONIGHT WITH WIDESPREAD
LIGHT TO MODERATE RAINFALL EXPECTED. THE RAIN TAPERS TO SHOWERS AND
ENDS BY MONDAY EVENING AS HIGH PRESSURE BRIEFLY BUILDS INTO THE
REGION. GENERALLY DRY AND MILDER WEATHER IS EXPECTED FOR
TUESDAY...BEFORE THE THREAT OF SHOWERS INCREASES AGAIN BY MID WEEK
WITH THE APPROACH OF THE NEXT LOW PRESSURE SYSTEM.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 300 PM EDT SUNDAY...COMPLEX FORECAST TAKING SHAPE FOR TONIGHT
AS UPPER LEVEL LOW PRESSURE DRIFTS ATOP THE AREA WITH WIDESPREAD
RAINFALL. HI-RES RAP/HRRR DATA HAS CAPTURED CURRENT SCENARIO OUT
THROUGH THE NEXT 8 HOURS QUITE WELL AND WILL LEAN TOWARD ITS SOLN
ACCORDINGLY. AS SOUTHERLY FLOW HAS BECOME ESTABLISHED EAST OF THE
UPPER LOW CENTER TODAY...A DEEP WRN ATLANTIC/SUBTROPICAL MOISTURE
PLUME AND ASSOCIATED RAFL HAS EVOLVED SSE-NNW ACROSS NEW
ENGLAND...CAPTURED NICELY BY AMSU/SSM-I BLENDED TPW. THIS RAIN
BAND WILL CONTINUE TO PIVOT BACK TO THE NORTH AND WEST OVER OUR
CENTRAL AND NRN COUNTIES THIS EVENING INTO TONIGHT...EVOLVING INTO
A PRIMARY DEFORMATION ZONE AS THE UPPER LOW CENTER EDGES EAST. NOT
THE CLASSIC DEFORMATION SIGNATURE HOWEVER AS LOW LEVEL FLOW TRENDS
WEST TO SOUTHWESTERLY AFTER MIDNIGHT AND PCPN SHIELD BEGINS TO
TAKE ON A MORE OROGRAPHIC CHARACTER. NONETHELESS A WIDESPREAD
RAINFALL EVENT STILL ON TRACK FOR MUCH OF OUR CENTRAL AND NORTHERN
COUNTIES OVERNIGHT AND WILL CONTINUE CATEGORICAL POPS IN THESE
AREAS. SOUTHERN COUNTIES WILL BE SLIGHTLY REMOVED AND JUST SOUTH
OF THE PRIMARY RAIN BAND PIVOT POINT...AND WILL OFFER SLIGHTLY
LOWER POPS IN THESE AREAS...BUT ALL LOCATIONS TO AT LEAST SEE A
MEASUREABLE RAINFALL WITH HIGHEST AMOUNTS NORTH. LOWS AGAIN VERY
UNIFORM GIVEN LIGHT WINDS AND LACK OF LOW LEVEL THERMAL
ADVECTION...GENERALLY U40S TO L50S. PATCHY FOG ALSO A GOOD BET
HERE AND THERE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM EDT SUNDAY...AS UPPER LOW DRIFTS NORTHEAST AND SLOWLY
AWAY FROM THE REGION ON MONDAY...DEFORMATION/OROGRAPHICALLY FORCED
PCPN SHIELD SHOULD SLOWLY ERODE/WEAKEN OVER TIME...WITH MOST AREAS
OUTSIDE OF THE NORTHERN MTNS TRENDING DRY BY THE AFTERNOON HOURS.
SOUTH TO SOUTHWESTERLY FLOW TO CONTINUE WITH CONDITIONS GUSTY AT
TIMES BY AFTERNOON. HIGHS A TAD MILDER AS 925-850 THERMAL PROFILES
GRADUALLY MODERATE...GENERALLY IN THE 58 TO 65 RANGE WITH MILDEST
READINGS WEST.
FAIR AND DRY WEATHER THEN RETURNS BY MONDAY NIGHT INTO MUCH OF
TUESDAY AS SHORTWAVE RIDGING BUILDS INTO THE NORTHEAST FROM THE
MID-ATLANTIC/OHIO VALLEY STATES. GENERALLY CLR TO PC CONDS EXPECTED
WITH MILDER NEAR SEASONABLE TEMPERATURES EXPECTED. CLOUDS AND A
LOWER END THREAT OF SHOWERS WILL BE ON THE INCREASE BY TUESDAY
EVENING INTO TUESDAY NIGHT HOWEVER AS NEXT UPPER SHORTWAVE TROUGH
OPENS UP AND LIFTS NORTHEAST OUT OF THE MISS/TENN VALLEY REGION.
LATEST MODEL TRENDS HAVE SHIFTED CONSIDERABLY FURTHER WEST WITH THIS
FEATURE ON THE 12Z MODEL SUITE HOWEVER...DEPICTING MILDER SOUTHERLY
FLOW AND A MORE SCATTERED NATURE TO THE SHOWER ACTIVITY AS MEAN H5
BERMUDA RIDGING STRENGTHENS AND SHIFTS WEST TO NEAR 30N/-70W. WITH
SUCH BROAD CONSENSUS...HARD TO IGNORE THIS POTENTIAL SHIFT IN
THINKING...AND HAVE TRENDED POPS BACK SOMEWHAT INTO THE 30/40%
RANGE ALONG WITH RAISING MIN TEMPS BY 2-4 DEG ACROSS THE BOARD.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 324 AM EDT SUNDAY...GOOD RUN-TO-RUN CONSISTENCY NOW SHOWN
IN GFS SOLNS LAST SEVERAL CYCLES. GOOD CONSISTENCY WITH 00Z GFS
ENSEMBLE AND 00Z ECMWF THROUGH THURSDAY BEFORE ECMWF DIVERGES
SIGNIFICANTLY. CURRENT FCST GENERALLY FOLLOWS 00Z GFS.
SRN STREAM 500MB TROUGH EXTENDING ACROSS THE MID/LWR MS RIVER
VALLEY AT 00Z WEDNESDAY IS EXPECTED TO BE ASSOCIATED WITH A WEAK
SFC LOW PRESSURE SYSTEM VCNTY OF THE UPR OHIO VLY/CENTRAL
APPALACHIANS. EWD EXTENDING WARM FRONT EXPECTED TO LIFT NWD
BRINGING INCREASING CLOUDS AND A CHANCE OF SHOWERS TO THE NORTH
COUNTRY TUESDAY NIGHT. 850MB TEMPS PROGGED TO BE QUITE WARM (00Z
GFS SHOWS +14C AT 850MB BY 12Z WED). WITH CLOUDS AND WAA SHOULD
SEE LOWS GENERALLY IN THE 50S AREAWIDE. WEDNESDAY AND WEDNESDAY
NIGHT...EXPECT TO SEE SRN STREAM SHORTWAVE TROUGH BEGIN TO SHEAR
NEWD WITH WEAK SFC LOW PASSING WEST OF THE NORTH COUNTRY DURING
THE DAY WEDNESDAY. CAN/T RULE OUT CONTINUED CHANCES OF SHOWERS
WED/WED NIGHT WITH SKIES REMAINING MOSTLY CLOUDY. AIR MASS QUITE
MILD SO HIGHS IN THE LOWER 70S APPEAR MOST LIKELY...WITH LOWS
AGAIN IN THE 50S WED NIGHT. SOME CLEARING EXPECTED THURSDAY WITH
DRIER CONDITIONS AS TROUGH DEPARTS. 850MB TEMPS COOL SLIGHTLY TO
ABOUT +10C FOR THURSDAY SO STILL LOOKING AT HIGHS UPR 60S TO LWR
70S. DEEP-LAYER RIDGE BRIEFLY IN PLACE THU NGT INTO EARLY FRIDAY
SO KEPT THAT PERIOD DRY. A COLD FRONT APPROACHES FROM THE GREAT
LAKES FRIDAY AFTN WITH CHANCES FOR SHOWERS FRIDAY AFTN ACROSS NRN
NY. PRECEDING AIR MASS STILL MILD WITH HIGHS UPR 60S TO LWR 70S
LIKELY. SHOWERS AREAWIDE FRIDAY NIGHT ASSOCIATED WITH COLD FRONT.
SATURDAY LOOKS COOLER WITH GUSTY WESTERLY WINDS POSSIBLE. MAY
STILL SEE SOME ISOLD -SHRA WITH SHALLOW INSTABILITY...ESPECIALLY
ACROSS THE HIGHER TERRAIN. HIGHS SATURDAY FORECAST AROUND 60
EXCEPT LOW-MID 50S FOR NRN NY. IT/S WORTH NOTING THAT THE 00Z
ECMWF SHOWS A CONSIDERABLY SLOWER ARRIVAL OF THE COLD FRONT...SO
IT/S POSSIBLE TEMPERATURES WILL BE WARMER THAN FORECAST SATURDAY
WITH FRONTAL PASSAGE NOT UNTIL SATURDAY NIGHT. CURRENT FCST
REFLECTS 00Z GFS AND 00Z GFS ENSEMBLE MEAN SOLNS.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...DEEP CLOSED 5H/7H CYCLONIC CIRCULATION ACRS
NORTHERN PA WL CONT TO ADVECT PLENTY OF MOISTURE ACRS OUR TAF
SITES THRU TONIGHT. OVERALL IFR CONDITIONS WL CONT AT SLK/MSS WITH
MAINLY IFR AT BTV/MPV/RUT...AND MVFR AT PBG THRU THIS AFTN/EVENING. VAD
PROFILE SHOWS NORTHERLY FLW DOWN THE CPV...HELPING TO ENHANCE LLVL
MOISTURE CONVERGENCE AT BTV WITH CRNT RADAR SHOWING A BAND OF
MODERATE RAIN ROTATING INTO OUR NORTHERN/CENTRAL TAF SITES. OBS
INDICATING IFR CONDITIONS WITH VIS BTWN 1-3SM AND CIGS BROKEN TO
OVERCAST AT 400 TO 800 FT. THIS BAND OF RAIN WL SLOWLY LIFT FROM
SE TO NW ACRS OUR TAF SITES THRU THE REST OF THIS AFTN. THIS
EVENING...BOTH RAP AND NAM SHOW A WIND SHIFT TO THE SW BTWN 03Z
AND 05Z...WHICH WL RESULT IN DOWNSLOPE FLW AND SOME IMPROVING CIGS
AT BTV/PBG. WL MENTION MVFR CONDITIONS. OTHERWISE...ANTICIPATE
MAINLY IFR CIGS TO CONT AT MPV/RUT/SLK/MPV WITH PATCHY DRIZZLE/FOG
REDUCING VIS BTWN 1-3SM AT TIMES. BUFKIT VERTICAL MOISTURE
PROFILES SHOW A SLOW DECREASE IN RH BTWN 13-15Z WITH BETTER
MIXING...RESULTING IN MVFR CONDITIONS AT MOST SITES. SLOWEST SITES
TO CLR WL BE SLK/MPV.
OUTLOOK 18Z MONDAY THROUGH THURSDAY...
WEAK SFC RIDGE WL RESULT IN DRYING ALOFT AND AT THE SFC WITH
MAINLY VFR CONDITIONS AT BTV/MSS/RUT/PBG AND MVFR BECMG VFR AT
MPV/SLK FROM 18Z THRU 18Z WEDS. SOME PATCHY FOG WL BE POSSIBLE AT
SLK/MPV MONDAY NIGHT/TUES MORNING. NEXT SYSTEM ARRIVES WEDS AFTN
INTO THURS WITH MORE SCATTERED SHOWERS AND POTENTIAL PERIODS OF
MVFR CONDITIONS.
&&
.HYDROLOGY...
AS OF 300 PM EDT SUNDAY...WIDESPREAD RAINFALL EXPECTED THIS
EVENING INTO TONIGHT WITH DEFORMATION/WRAP-AROUND PCPN AFFECTING
THE REGION ASSOC WITH PASSG OF UPPER LOW PRESSURE. 24-HR BASIN
TOTALS GENERALLY IN THE 0.50 TO 1.0 INCH RANGE ACROSS CENTRAL AND
NORTHERN WATERSHEDS...AND 0.25 TO 0.50 INCH SOUTH. ONLY MODESTLY
MOIST ANTECEDENT GROUND CONDITIONS AND ONLY SLIGHT TO MODEST RISES
ON AREA RIVERS OF 1-2 FEET EXPECTED AS RUNOFF PEAKS BY MONDAY
AFTERNOON.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...BANACOS
AVIATION...TABER
HYDROLOGY...JMG
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
152 PM EDT SUN SEP 30 2012
.SYNOPSIS...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL LIFT THROUGH THE REGION
TODAY AND ON MONDAY...BRINGING A CHANCE FOR PRECIPITATION DURING
THIS TIME. HIGH PRESSURE RETURNS FOR TUESDAY...FOLLOWED BY ANOTHER
LOW PRESSURE SYSTEM FOR WEDNESDAY AND THURSDAY. HIGH PRESSURE WILL
MOVE OVER THE AREA AGAIN BY FRIDAY.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
AS OF 1010 AM EDT SUNDAY...SIGNIFICANT CHANGES MADE AS OF MID-
MORNING TO RAMP POPS UPWARD ACROSS OUR CENTRAL/NRN COUNTIES PER
LATEST RADAR AND 10Z RAP/HRRR COMP REFLECTIVITY PROGS. IMPRESSIVE
WRN ATLANTIC MOISTURE PLUME AND ASSOC RAFL CONTINUES TO EVOLVE AND
PUSH FAIRLY QUICKLY NORTH/NORTHWESTWARD INTO EAST/SOUTHEAST NEW
ENGLAND THIS MORNING IN RESPONSE TO DEEPENING SOUTHERLY FLOW ON
THE EAST SIDE OF LARGE-SCALE UPPER CUTOFF LOW OVER THE ERN GREAT
LAKES. THIS RAFL SHOULD SPREAD FAIRLY QUICKLY INTO THE
NORTHEASTERN HALF OF VERMONT BY 18Z...THEN PIVOT SLOWLY WEST AND
THEN SOUTH ACROSS OUR NRN COUNTIES...TAKING ON A PRONOUNCED
DEFORMATIONAL SIGNATURE BY THIS EVENING INTO TONIGHT AS UPPER LOW
PASSES ATOP AND EAST OF THE REGION. 24-HR PCPN TOTALS BY 12Z
MONDAY FROM A FEW TENTHS SOUTH...AND GENERALLY IN THE 0.50 TO 1.0
INCH RANGE NORTH WITH LOCALIZED HIGHER TOTALS ALONG THE WRN NRN
MTN SLOPES. IN REGARD TO OTHER WEATHER ELEMENTS...ONLY NOMINAL
ADJUSTMENTS WERE MADE TO T/TD/MAX T DATASETS...MAINLY BLENDING
CURRENT OBSERVATIONAL DATA IN WITH LATEST LAMP DATA...WHICH WOULD
OFFER NEAR STEADY OR SLIGHTLY COOLER VALUES (1-2 DEG) TODAY. REST
OF FCST UNCHANGED.
PREVIOUS DISCUSSION...CLDY SKIES
PERSIST ACROSS THE NORTH COUNTRY THIS MORNING AS A BROAD UPPER LOW
CONTINUES TO SPIN OVER THE NORTHEAST. BULK OF PRECIP ASSOCIATED
WITH THIS SYSTEM AWAY FROM THE CWA ATTM...WITH ONLY --RW/-DZ AND
FG PERSISTING. EXPECTING THESE CONDITIONS TO GO THRU MORNING/EARLY
AFTNOON HRS...THEN INCR IN AREAL COVERAGE/INTENSITY COMES TO OUR
REGION AS LOW BEGINS TO LIFT NNE INTO QUEBEC. MOISTURE ALONG THE
SOUTHERN AND EASTERN PORTIONS OF THE SYSTEM WILL BRING HEAVIER
SHOWER ACTIVITY LASTING THRU THE EVENING/OVERNIGHT HRS. DO EXPECT
FOCUS OF PRECIP TO SLOWLY SHIFT FROM S TO N AS LOW GOES NORTH OF
US. TOWARDS MORNING WITH GENERAL WNW FLOW DEVELOPING...HIGHEST
POPS FOR REMAINING SHOWER ACTIVITY WILL BE CONCENTRATED OVER HIR
ELEV...ESPECIALLY NE VT. CLDY SKIES THRU THE 24-HR PERIOD WILL
KEEP TEMPS FAIRLY STAGNANT. YESTERDAY/S HIGH/LOW COMBO WERE
57F/52F HERE AT BTV. EXPECTING SIMILAR TREND FOR HERE AND REST OF
CWA WITH LITTLE TEMP VARIANCE WITH HIGHS IN THE 50S AND LOW IN THE
U40S TO AROUND 50F.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH TUESDAY/...
AS OF 414 AM EDT SUNDAY...WITH UPPER LOW FINALLY INTO SOUTHERN
QUEBEC...REMAINING PRECIP OVER THE AREA WILL FOCUS ON THE NORTHERN
ZONES/HIR TRRN. BY MONDAY AFTNOON/EARLY EVENING...WK RIDGE BUILDING
NORTH INTO THE AREA WILL FORCE ANY REMAINING PRECIP OVER NE VT OUT
OF THE AREA. DRY CONDITIONS OVER THE CWA WILL ONLY LAST MONDAY NGT
INTO EARLY TUESDAY AS MDLS BRING NEXT LOW THRU THE OHIO/TENNESSEE
VALLEYS AND INTO THE CWA FROM THE SW. BULK OF MEASURABLE PRECIP
STAYS MAINLY CONFINED TO N NY WITH --RW FOR CVLY/SW VT. LACK OF
THICK CLD COVER WILL ALLOW FOR SLIGHT WARMING TREND THRU THE AREA
WITH HIGHS TIPPING UP INTO THE 60-65F RANGE. OVERNGT LOWS GET A
BUMP UP AS WELL INTO THE 40S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 324 AM EDT SUNDAY...GOOD RUN-TO-RUN CONSISTENCY NOW SHOWN
IN GFS SOLNS LAST SEVERAL CYCLES. GOOD CONSISTENCY WITH 00Z GFS
ENSEMBLE AND 00Z ECMWF THROUGH THURSDAY BEFORE ECMWF DIVERGES
SIGNIFICANTLY. CURRENT FCST GENERALLY FOLLOWS 00Z GFS.
SRN STREAM 500MB TROUGH EXTENDING ACROSS THE MID/LWR MS RIVER
VALLEY AT 00Z WEDNESDAY IS EXPECTED TO BE ASSOCIATED WITH A WEAK
SFC LOW PRESSURE SYSTEM VCNTY OF THE UPR OHIO VLY/CENTRAL
APPALACHIANS. EWD EXTENDING WARM FRONT EXPECTED TO LIFT NWD
BRINGING INCREASING CLOUDS AND A CHANCE OF SHOWERS TO THE NORTH
COUNTRY TUESDAY NIGHT. 850MB TEMPS PROGGED TO BE QUITE WARM (00Z
GFS SHOWS +14C AT 850MB BY 12Z WED). WITH CLOUDS AND WAA SHOULD
SEE LOWS GENERALLY IN THE 50S AREAWIDE. WEDNESDAY AND WEDNESDAY
NIGHT...EXPECT TO SEE SRN STREAM SHORTWAVE TROUGH BEGIN TO SHEAR
NEWD WITH WEAK SFC LOW PASSING WEST OF THE NORTH COUNTRY DURING
THE DAY WEDNESDAY. CAN/T RULE OUT CONTINUED CHANCES OF SHOWERS
WED/WED NIGHT WITH SKIES REMAINING MOSTLY CLOUDY. AIR MASS QUITE
MILD SO HIGHS IN THE LOWER 70S APPEAR MOST LIKELY...WITH LOWS
AGAIN IN THE 50S WED NIGHT. SOME CLEARING EXPECTED THURSDAY WITH
DRIER CONDITIONS AS TROUGH DEPARTS. 850MB TEMPS COOL SLIGHTLY TO
ABOUT +10C FOR THURSDAY SO STILL LOOKING AT HIGHS UPR 60S TO LWR
70S. DEEP-LAYER RIDGE BRIEFLY IN PLACE THU NGT INTO EARLY FRIDAY
SO KEPT THAT PERIOD DRY. A COLD FRONT APPROACHES FROM THE GREAT
LAKES FRIDAY AFTN WITH CHANCES FOR SHOWERS FRIDAY AFTN ACROSS NRN
NY. PRECEDING AIR MASS STILL MILD WITH HIGHS UPR 60S TO LWR 70S
LIKELY. SHOWERS AREAWIDE FRIDAY NIGHT ASSOCIATED WITH COLD FRONT.
SATURDAY LOOKS COOLER WITH GUSTY WESTERLY WINDS POSSIBLE. MAY
STILL SEE SOME ISOLD -SHRA WITH SHALLOW INSTABILITY...ESPECIALLY
ACROSS THE HIGHER TERRAIN. HIGHS SATURDAY FORECAST AROUND 60
EXCEPT LOW-MID 50S FOR NRN NY. IT/S WORTH NOTING THAT THE 00Z
ECMWF SHOWS A CONSIDERABLY SLOWER ARRIVAL OF THE COLD FRONT...SO
IT/S POSSIBLE TEMPERATURES WILL BE WARMER THAN FORECAST SATURDAY
WITH FRONTAL PASSAGE NOT UNTIL SATURDAY NIGHT. CURRENT FCST
REFLECTS 00Z GFS AND 00Z GFS ENSEMBLE MEAN SOLNS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...DEEP CLOSED 5H/7H CYCLONIC CIRCULATION ACRS
NORTHERN PA WL CONT TO ADVECT PLENTY OF MOISTURE ACRS OUR TAF
SITES THRU TONIGHT. OVERALL IFR CONDITIONS WL CONT AT SLK/MSS WITH
MAINLY IFR AT BTV/MPV/RUT...AND MVFR AT PBG THRU THIS AFTN/EVENING. VAD
PROFILE SHOWS NORTHERLY FLW DOWN THE CPV...HELPING TO ENHANCE LLVL
MOISTURE CONVERGENCE AT BTV WITH CRNT RADAR SHOWING A BAND OF
MODERATE RAIN ROTATING INTO OUR NORTHERN/CENTRAL TAF SITES. OBS
INDICATING IFR CONDITIONS WITH VIS BTWN 1-3SM AND CIGS BROKEN TO
OVERCAST AT 400 TO 800 FT. THIS BAND OF RAIN WL SLOWLY LIFT FROM
SE TO NW ACRS OUR TAF SITES THRU THE REST OF THIS AFTN. THIS
EVENING...BOTH RAP AND NAM SHOW A WIND SHIFT TO THE SW BTWN 03Z
AND 05Z...WHICH WL RESULT IN DOWNSLOPE FLW AND SOME IMPROVING CIGS
AT BTV/PBG. WL MENTION MVFR CONDITIONS. OTHERWISE...ANTICIPATE
MAINLY IFR CIGS TO CONT AT MPV/RUT/SLK/MPV WITH PATCHY DRIZZLE/FOG
REDUCING VIS BTWN 1-3SM AT TIMES. BUFKIT VERTICAL MOISTURE
PROFILES SHOW A SLOW DECREASE IN RH BTWN 13-15Z WITH BETTER
MIXING...RESULTING IN MVFR CONDITIONS AT MOST SITES. SLOWEST SITES
TO CLR WL BE SLK/MPV.
OUTLOOK 18Z MONDAY THROUGH THURSDAY...
WEAK SFC RIDGE WL RESULT IN DRYING ALOFT AND AT THE SFC WITH
MAINLY VFR CONDITIONS AT BTV/MSS/RUT/PBG AND MVFR BECMG VFR AT
MPV/SLK FROM 18Z THRU 18Z WEDS. SOME PATCHY FOG WL BE POSSIBLE AT
SLK/MPV MONDAY NIGHT/TUES MORNING. NEXT SYSTEM ARRIVES WEDS AFTN
INTO THURS WITH MORE SCATTERED SHOWERS AND POTENTIAL PERIODS OF
MVFR CONDITIONS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JN
NEAR TERM...JMG/JN
SHORT TERM...JN
LONG TERM...BANACOS
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
513 PM EDT SUN SEP 30 2012
.SYNOPSIS...
A DEEP UPPER LOW PRESSURE SYSTEM WILL ROTATE THROUGH NORTHERN
PENNSYLVANIA THIS AFTERNOON...THEN QUICKLY LIFT AWAY FROM THE
AREA TONIGHT. HIGH PRESSURE WILL BRIEFLY VISIT THE REGION ON
MONDAY. WET WEATHER WILL RETURN TO THE KEYSTONE STATE MONDAY NIGHT
THROUGH TUESDAY AS A WAVE OF LOW PRESSURE EJECTS NORTHWARD FROM
THE CENTRAL GULF STATES.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
NMRS INSTABILITY SHOWERS NOW EVIDENT ON RADAR ACRS MUCH OF THE
CWA...DRIVEN BY THE HEATING OF THE DAY /ALBEIT MODEST/ UNDER H5-H7
COLD POOL OF -15C. THIS IS RESULTING IN MID-LVL LAPSE RATES
AROUND 7 C/KM -- A VERY STRONG SIGNAL FOR INSTABILITY SHOWERS.
SMALL HAIL WILL BE POSSIBLE IN THE MORE ROBUST...LOW-TOPPED
CONVECTIVE CELLS. THE LATEST HRRR HAD DONE QUITE WELL WITH THE
SHOWER PLACEMENT THUS FAR...WITH THE GREATEST CONCENTRATION OF
SHOWER ACTIVITY ALONG I-80 AND OVR THE LAURELS/S-CENTRAL MTNS. THE
BAND OF CONVECTIVE SHOWERS CURRENTLY OVR THE S-CENTRAL MTNS SHOULD
REACH THE LWR SUSQ VLY METRO AREAS AROUND 20Z.
BKN-OVC CUMULUS/STRATOCU SHOULD START TO FIZZLE OUT THIS EVE WITH
PARTIAL CLEARING EXPECTED BY LATE TONIGHT. BY THE SAME TOKEN...EXPECT
INSTABILITY SHOWERS/ISOLD TSRA TO QUICKLY FADE AND EVENTUALLY
DISSIPATE WITH THE LOSS OF HEATING SHORTLY AFT 00Z. LLVL MSTR MAY
GET TRAPPED BLW INVERSION AND RESULT IN LOW STRATUS/FOG INTO EARLY
MONDAY MORNING...ESP ACRS THE ALLEGHENIES GIVEN WEAK WNW UPSLOPE.
HAVE ADDED MENTION OF FG LATE TONIGHT WITH THE FINAL AFTN UPDATE.
OTHERWISE...NO MAJOR CHANGES TO NEAR TERM FCST. OVERNIGHT LOWS
WILL BE NEAR SEASONAL NORMALS...WITH THE COLDEST READINGS OVR THE
WRN MTNS WHERE THE BEST RADIATIONAL COOLING SHOULD OCCUR.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AFTER SOME PATCHY EARLY MORNING FOG/LOW CLOUDS...SFC RIDGE WILL
BISECT THE STATE...IN BETWEEN DEPARTING NRN STREAM UPPER TROUGH/LOW
LIFTING NWD ACRS NRN NEW ENGLAND AND DEVELOPING SRN STREAM WAVE OVR
MS/AL. EXPECT AN INCREASE IN MID-HIGH CLOUDS IN ADVANCE OF THE SRN
SYSTEM LATE IN THE DAY...AS IT MOVES NWD INTO THE TN VLY BY 00Z
TUE. HIGHS WILL BE QUITE PLEASANT IN THE 60S TO LOWER 70S NORTH TO
SOUTH.
MDLS IN DECENT AGREEMENT IN MOVG THE SFC WAVE INTO TN/KY BY THE
END OF THE PERIOD. ANOMALOUS SLY LLJ WILL SUPPORT ROBUST NWD MSTR
FLUX INTO THE AREA MON NGT...WITH PWATS SURGING TO +2-3SD BY 12Z
TUE. ANOTHER INTERESTING FEATURE IS PERHAPS A DUEL MSTR FEED FM
THE GOMEX AND ATM RIVER EMANATING FM THE BAHAMAS. THE LATTER
SHOULD BECOME THE MAIN SOURCE OF HI PWATS INTO TUES. THE 12Z
MODELS STILL DISPLAY SOME DETAIL DIFFS WITH THIS SYS AND THEREFORE
ONLY MADE MINOR TWEAKS TO THE SHORT TERM FCST FOR THE DY2 FINALS.
HOWEVER WITH SUPPORT FROM THE 12Z GEFS/09Z SREF...STILL FEEL THAT
HIGHER POPS ARE JUSTIFIED /ESPECIALLY FROM 06-12Z TUES/ GIVEN THE
STG WAA/ISENT LIFT AND MSTR TRANSPORT INTO THE REGION.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
BY TUES...LARGE SCALE PATTERN WILL FEATURE HIGH AMPLITUDE TROUGH
WITH UPPER LOW CENTERED NEAR MISSOURI. SFC LOW WILL BE LIFTING
INTO THE OHIO VALLEY DRAGGING AN OCCLUDED FRONT THROUGH PA LATER
TUE OR TUE NIGHT. THE SHORT RANGE GUIDANCE SHOWS ERODING
STABILITY AND SUGGESTS THE POSSIBILITY OF SOME CONVECTION AS THE
FRONT GETS CLOSER TUES...MAINLY ACROSS THE SOUTHERN HALF. QPF ON
TUE LOOKS TO BE AROUND 0.25 ON AVERAGE...BUT HIGHER AMOUNTS ARE
POSS.
SOAKING RAIN CONTINUES INTO TUE NIGHT/EARLY WED AS SOUTHERLY FLOW
ALOFT RIDES OVER THE SFC LOW...AND SHORTWAVE ENERGY SLIDES AROUND
BASE OF TROUGH BEFORE EJECTING INTO OHIO VALLEY WED. MODELS STILL
HINTING AT WEAK SECONDARY SFC WAVE DEVELOPMENT TO OUR SE...WHICH
MAY PEEL POTENTIAL FOR 1 INCH QPFS AWAY FROM PA RESULTING IN A
WIDESPREAD LIGHT TO MODERATE RAIN...AND A MINIMAL FLOOD THREAT AT
THIS TIME.
AFTER THE SFC LOW/FRONT CLEARS THE AREA...THE UPPER LOW WILL THEN
PUSH THROUGH WED/WED NIGHT...KEEPING MENTION OF SHOWERS IN THE
FORECAST - MAINLY IN THE WEST AS DRY SLOT APPEARS TO WORK IN WITH
RIDGE NOSING IN FROM THE SOUTH.
THU AND FRI WILL SEE SFC RIDGING AND W/SW UPPER FLOW...WHICH
SHOULD KEEP THE REGION DRY WITH NEAR/SLIGHTLY ABOVE NORMAL TEMPS.
MODELS CONTINUE TO PRODUCE DIVERGING FORECASTS FOR THE WEEKEND.
THE GEFS/GFS AND CANADIAN MODELS SHOW AN APPROACHING ALBEIT FADING
FRONT LATER FRIDAY WITH THE PARENT UPPER SHORTWAVE WANTING TO
SHEAR OUT WELL NORTH AND WEST OF HERE. THE ECMWF /UNUSUALLY/
CONTINUES TO BE AN OUTLIER...HOLDING ITS UPPER ENERGY BACK
RESULTING IN A BROAD WSW FLOW EVENTUALLY ESTABLISHING OVER THE GR
LAKES AND NERN US. THIS RESULTS IN THE MODEL DEVELOPING A SLOW
MOVING WAVY ANA-FRONT THAT APPROACHES THE AREA FOR THE WEEKEND.
TOUGH TO EVEN LEAN FORECAST ONE WAY OR THE OTHER WITH SUCH
DIFFERENCE IN GUIDANCE...SO HAD TO KEEP LOW POPS ACROSS SEVERAL
PERIODS...THOUGH PAINTED HIGHEST POPS ON SAT. FOR
TEMPS...GRADUALLY OOZED COOLER TEMPERATURES INTO THE REGION FROM
SAT INTO MON.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
COLD AIR ALOFT AND DAYTIME HEATING RESULTING IN SCT-BKN CU FIELD
ACRS CENTRAL PA TERMINALS LATE THIS AFTN...WITH VFR CLOUD BASES
BTWN 5-7KFT AGL. AS EXPECTED...SCT INSTABILITY SHOWERS HAVE
DEVELOPED UNDER THE COLD POOL ALOFT...WITH THE MOST CONCENTRATED
AREA OF SHRA...AND A FEW TSRA...NEAR THE MASON-DIXON LINE IN ASSOC
WITH AN UPPER LVL DISTURBANCE TRACKING ACROSS SOUTHERN PA.
ALTHOUGH MOST LOCATIONS WILL REMAIN VFR...CAN/T RULE OUT A
LOCALIZED...BRIEF VSBY REDUCTION FROM ONE OF THESE SHOWERS THRU
ABOUT 00Z.
WITH THE LOSS OF DAYTIME HEATING...EXPECT DIURNAL SHOWERS TO
QUICKLY DISSIPATE AFTER SUNSET. SFC HIGH PRES WILL SLIDE INTO THE
REGION FROM THE UPPER OH VLY OVERNIGHT. SOME RESIDUAL LLVL MSTR
MAY GET TRAPPED UNDER INVERSION AND RESULT IN LOW CIGS/FOG
OVERNIGHT...ESP OVR THE WRN MTNS GIVEN WEAK UPSLOPE FLOW. HAVE
ADDED A PERIOD OF LOW CIGS/VIS BTWN 09-13Z ACRS THE WRN AND
CENTRAL AIRFIELDS.
OUTLOOK...
MON...AM LOW CIGS/FOG PSBL ACROSS THE W-CENTRAL MTNS...BCMG VFR.
TUE...RAIN/LOW CIGS LIKELY.
WED...RAIN/LOW CIGS POSSIBLE.
THU-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...FITZGERALD/STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
226 PM EDT SUN SEP 30 2012
.SYNOPSIS...
A DEEP UPPER LOW PRESSURE SYSTEM WILL ROTATE THROUGH NORTHERN
PENNSYLVANIA THIS AFTERNOON...THEN QUICKLY LIFT AWAY FROM THE
AREA TONIGHT. HIGH PRESSURE WILL BRIEFLY VISIT THE REGION ON
MONDAY. WET WEATHER WILL RETURN TO THE KEYSTONE STATE MONDAY NIGHT
THROUGH TUESDAY AS A WAVE OF LOW PRESSURE EJECTS NORTHWARD FROM
THE CENTRAL GULF STATES.
&&
.NEAR TERM /THROUGH TONIGHT/...
NMRS INSTABILITY SHOWERS NOW EVIDENT ON RADAR ACRS MUCH OF THE
CWA...DRIVEN BY THE HEATING OF THE DAY /ALBEIT MODEST/ UNDER H5-H7
COLD POOL OF -15C. THIS IS RESULTING IN MID-LVL LAPSE RATES
AROUND 7 C/KM -- A VERY STRONG SIGNAL FOR INSTABILITY SHOWERS.
SMALL HAIL WILL BE POSSIBLE IN THE MORE ROBUST...LOW-TOPPED
CONVECTIVE CELLS. THE LATEST HRRR HAD DONE QUITE WELL WITH THE
SHOWER PLACEMENT THUS FAR...WITH THE GREATEST CONCENTRATION OF
SHOWER ACTIVITY ALONG I-80 AND OVR THE LAURELS/S-CENTRAL MTNS. THE
BAND OF CONVECTIVE SHOWERS CURRENTLY OVR THE S-CENTRAL MTNS SHOULD
REACH THE LWR SUSQ VLY METRO AREAS AROUND 20Z.
BKN-OVC CUMULUS/STRATOCU SHOULD START TO FIZZLE OUT THIS EVE WITH
PARTIAL CLEARING EXPECTED BY LATE TONIGHT. BY THE SAME TOKEN...EXPECT
INSTABILITY SHOWERS/ISOLD TSRA TO QUICKLY FADE AND EVENTUALLY
DISSIPATE WITH THE LOSS OF HEATING SHORTLY AFT 00Z. LLVL MSTR MAY
GET TRAPPED BLW INVERSION AND RESULT IN LOW STRATUS/FOG INTO EARLY
MONDAY MORNING...ESP ACRS THE ALLEGHENIES GIVEN WEAK WNW UPSLOPE.
HAVE ADDED MENTION OF FG LATE TONIGHT WITH THE FINAL AFTN UPDATE.
OTHERWISE...NO MAJOR CHANGES TO NEAR TERM FCST. OVERNIGHT LOWS
WILL BE NEAR SEASONAL NORMALS...WITH THE COLDEST READINGS OVR THE
WRN MTNS WHERE THE BEST RADIATIONAL COOLING SHOULD OCCUR.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AFTER SOME PATCHY EARLY MORNING FOG/LOW CLOUDS...SFC RIDGE WILL
BISECT THE STATE...IN BETWEEN DEPARTING NRN STREAM UPPER TROUGH/LOW
LIFTING NWD ACRS NRN NEW ENGLAND AND DEVELOPING SRN STREAM WAVE OVR
MS/AL. EXPECT AN INCREASE IN MID-HIGH CLOUDS IN ADVANCE OF THE SRN
SYSTEM LATE IN THE DAY...AS IT MOVES NWD INTO THE TN VLY BY 00Z
TUE. HIGHS WILL BE QUITE PLEASANT IN THE 60S TO LOWER 70S NORTH TO
SOUTH.
MDLS IN DECENT AGREEMENT IN MOVG THE SFC WAVE INTO TN/KY BY THE
END OF THE PERIOD. ANOMALOUS SLY LLJ WILL SUPPORT ROBUST NWD MSTR
FLUX INTO THE AREA MON NGT...WITH PWATS SURGING TO +2-3SD BY 12Z
TUE. ANOTHER INTERESTING FEATURE IS PERHAPS A DUEL MSTR FEED FM
THE GOMEX AND ATM RIVER EMANATING FM THE BAHAMAS. THE LATTER
SHOULD BECOME THE MAIN SOURCE OF HI PWATS INTO TUES. THE 12Z
MODELS STILL DISPLAY SOME DETAIL DIFFS WITH THIS SYS AND THEREFORE
ONLY MADE MINOR TWEAKS TO THE SHORT TERM FCST FOR THE DY2 FINALS.
HOWEVER WITH SUPPORT FROM THE 12Z GEFS/09Z SREF...STILL FEEL THAT
HIGHER POPS ARE JUSTIFIED /ESPECIALLY FROM 06-12Z TUES/ GIVEN THE
STG WAA/ISENT LIFT AND MSTR TRANSPORT INTO THE REGION.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE LARGE SCALE PATTERN QUICKLY RELOADS INTO A HIGH AMPLITUDE
TROF OVER THE EASTERN HALF OF THE US. THE DETAILS DIFFER BETWEEN
THE VARIOUS MODELS...BUT IT LOOKS LIKE THE CONSENSUS IS FOR A LOW
TO MOVE UP TOWARD THE CENTRAL GR LAKES...WITH THE OCCLUDED FRONT
EVENTUALLY SWINGING THRU THE REGION SOME TIME TUES NIGHT OR WED.
THE SHORT RANGE GUIDANCE SHOWS ERODING STABILITY AND SUGGESTS THE
POSSIBILITY OF SOME CONVECTION AS THE FRONT GETS CLOSER TUES.
03Z SREF STILL SHOWS AS MUCH AS A 30-50 PROB OF 24 HOUR RAINFALLS
OF AN INCH OR MORE OVER WEST-CENTRAL PA...MAINLY FROM TUESDAY INTO
WED. THIS ISN`T MUCH DIFFERENT THAN THE 21Z RUN. THE GEFS IS NOT
NEARLY AS AGGRESSIVE AND HAS SHIFTED ITS LOWER PROBABILITY OF ONE
INCH RAINS MAINLY OFF TO OUR SE...WHICH MATCHES BETTER TO WHERE
THE OPERATIONAL MODEL SUGGESTS THE POSSIBILITY OF A COASTAL
SECONDARY WAVE TO FORM. AT THIS STAGE THE DIFFERENCES IN GUIDANCE
MUDDY THE DETAILS...BUT WHAT LOOKS ALMOST ASSURED IS THAT WE WILL
SEE A WIDESPREAD LIGHT TO MODERATE RAIN...AND A MINIMAL FLOOD
THREAT AT THIS TIME.
AFTER THE SFC LOW/FRONT MOVES THROUGH...THE UPPER LOW WILL THEN
PUSH THROUGH WED/WED NIGHT KEEPING THE MENTION OF SHOWERS IN THE
FORECAST. BY THURSDAY WE SHOULD SEE ENOUGH RIDGING FROM THE WEST
TO DRY OUT...AT LEAST TEMPORARILY.
THE GEFS/GFS AND CANADIAN MODELS SHOW AN APPROACHING ALBEIT FADING
FRONT BY FRIDAY WITH THE PARENT UPPER SHORTWAVE WANTING TO SHEAR
OUT WELL NORTH AND WEST OF HERE. THE ECMWF AT THIS POINT IS AN
OUTLIER...HANGING MORE UPPER ENERGY BACK ITO THE NORTHERN
ROCKIES...RESULTING IN A BROAD WSW FLOW EVENTUALLY ESTABLISHING
OVER THE GR LAKES AND NERN US. THIS RESULTS IN THE MODEL
DEVELOPING A SLOW MOVING WAVY ANA-FRONT THAT APPROACHES THE AREA FOR
THE WEEKEND. DEPENDING ON TIMING...IT COULD EITHER BE MILD AND
DRY...OR CHILLY AND RAINY. AS A RESULT...HAVE CHOSEN TO NOT TOUCH
THE EXTENDED PORTION OF THE FORECAST WHERE WE NOW HAVE SMALL
CHANCES FOR RAIN...WHICH WOULD BETTER FIT A WASHING FRONTAL
PASSAGE CONCEPTUAL MODEL.
IT DOES LOOK LIKE ONCE THE RAIN MOVES THROUGH...WE SHOULD ENJOY
SEVERAL DAYS OF ABOVE NORMAL WARMTH STARTING ABOUT WEDNESDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
30/18Z...COLD AIR ALOFT AND DAYTIME HEATING RESULTING IN BKN
CU/SC FIELD ACRS CENTRAL PA TERMINALS THIS AFTN...WITH LOW-END
VFR CLOUD BASES BTWN 3.5-6KFT AGL. AS EXPECTED...SCT TO NMRS
INSTABILITY SHOWERS HAVE DEVELOPED UNDER THE COLD POOL ALOFT
ASSOC WITH A CLOSED UPPER LEVEL LOW PIVOTING OVR PA/NY. OCNL CG
LTG IS ALSO BEING OBSERVED IN SOME OF THE MORE ROBUST CELLS...AND
CANT RULE OUT A LCL TSRA IMPACT THRU EARLY EVE. HOWEVER CVRG/CONFIDENCE
REMAIN TOO LOW FOR MENTION IN TAFS. WITH THE LOSS OF DAYTIME
HEATING...EXPECT DIURNAL SHOWERS TO QUICKLY DISSIPATE SHORTLY AFT
00Z. SFC HIGH PRES WILL SLIDE INTO THE REGION FROM THE UPPER OH
VLY OVERNIGHT. SOME RESIDUAL LLVL MSTR MAY GET TRAPPED UNDER
INVERSION AND RESULT IN LOW CIGS/FOG OVERNIGHT...ESP OVR THE WRN
MTNS GIVEN WEAK UPSLOPE FLOW. HAVE ADDED A PERIOD OF LOW CIGS/VIS
BTWN 09-13Z ACRS THE WRN AND CENTRAL AIRFIELDS.
OUTLOOK...
MON...AM LOW CIGS/FOG PSBL ACROSS THE W-CENTRAL MTNS...BCMG VFR.
TUE...RAIN/LOW CIGS LIKELY.
WED...RAIN/LOW CIGS POSSIBLE.
THU-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...LA CORTE
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1259 PM CDT SUN SEP 30 2012
.AVIATION...DISCUSSION FOR 18Z TAFS
VFR CONDITIONS SHOULD DOMINATE. SCT SHOWERS AND STORMS WILL AFFECT
THE AREA THIS AFTERNOON AND HAVE INCLUDED VCTS AT KGUY AND KDHT FROM
30/21Z - 01/01Z. WITH SLIGHTLY LESS CONFIDENCE...ONLY UTILIZED VCSH
AT KAMA. MVFR CIGS/VSBYS CANNOT BE RULED OUT IN ANY HEAVIER
THUNDERSTORMS THIS AFTERNOON...BUT CONFIDENCE IS TOO LOW TO INCLUDE
AT THIS TIME AND WILL AMEND AS NECESSARY.
UNLESS A TAF SITE SEES SIGNIFICANT RAIN THIS AFTERNOON...FOG IS
UNLIKELY TO DEVELOP MONDAY MORNING. WINDS WILL BE LIGHT AND VARIABLE
INITIALLY...EVENTUALLY TAKING ON A NORTHERLY DIRECTION AT ABOUT
10-12KTS. GUSTS TO 20 KTS WILL BECOME LIKELY BY LATE MORNING
MONDAY...BUT ELECTED NOT TO INCLUDE ANOTHER LINE AT THE VERY END OF
THE TAF FOR THIS.
SIMPSON
&&
.PREV DISCUSSION... /ISSUED 1150 AM CDT SUN SEP 30 2012/
UPDATE...
QUICK UPDATE TO REMOVE DENSE FOG WORDING FROM ZONES AND INCREASE POPS
THIS AFTERNOON AS A SHRTWV IN NRLY FLOW SHOULD INTERACT WITH A SFC
TROUGH TO PROMOTE SCT STORMS AFTER 19-20Z. LATEST RUC FCST SHOWS
1500-2000 J/KG OF UNCAPPED MLCAPE BY MID AFTERNOON...WITH OTHER
MODELS SHOWING SLIGHTLY LESS INSTABILITY. RELATIVELY WEAK BULK SHEAR
OF 25-30KTS COULD PROMOTE MINIMAL STORM ORGANIZATION...BUT LACKING
LOW LVL DRY AIR SHOULD LIMIT DOWNDRAFT POTENTIAL. HAIL UP TO QUARTER
SIZE AND AN ISOLATED 60 MPH DOWNDRAFT COULD BE POSSIBLE IN STRONGER
STORMS...BUT EXPECT MOST CONVECTION THAT DOES DEVELOP THIS AFTERNOON
TO REMAIN JUST UNDER SVR LIMITS.
SIMPSON
PREV DISCUSSION... /ISSUED 642 AM CDT SUN SEP 30 2012/
AVIATION...
FOR THE 12Z KAMA TAF...THINK THE THREAT OF FG REDUCING VISIBILITIES
TO AIRFIELD MINIMUMS IS MOSTLY OVER...THOUGH COULD SEE TEMPO MVFR
CONDITIONS OVER THE NEXT FEW HOURS. THE LIGHT SW WINDS HAVE HELPED
SCOUR OUT THE FG AND BRING IN SLIGHTLY DRIER AIR. THERE IS A SLIGHT
CHANCE...20 PERCENT...OF TSRA BETWEEN 18 AND 06Z...BUT THIS LOOKS
VERY UNLIKELY GIVEN LACK OF A SOURCE OF LOW LEVEL LIFT...AND
UNFAVORABLE MEAN FLOW TO BRING TSRA FROM ROCKIES THIS FAR E. GFS LAMP
SHOWS BR AND LOW CEILINGS REDEVELOPING TONIGHT...BUT THINK THIS IS
UNLIKELY GIVEN LACK OF SIGNIFICANT RAIN FALL OVER THE LAST 24 HOURS
PLUS SLIGHT DOWNSLOPE COMPONENT IN THE WINDS FOR MUCH OF THE TAF
PERIOD. IN ADDITION...THE TIME HEIGHT DISPLAYS FOR BOTH THE GFS AND
NAM SHOW LOW LEVEL RELATIVE HUMIDITY VALUES WELL BELOW SATURATION.
FOR THE 12Z KDHT AND KGUY TAFS...LOW CEILINGS AND FG SHOULD
INTERMITTENTLY AFFECT THE TAF SITES...ESPECIALLY KDHT...FOR THE NEXT
3 HOURS BEFORE DISSIPATING WITH INCREASED MIXING IN A TYPICAL DIURNAL
PATTERN. THERE IS A SMALL CHANCE...20 TO 30 PERCENT...OF TSRA BETWEEN
18 AND 06Z. FOR NOW HAVE LEFT MENTION OUT OF THE TAFS AS THE MEAN
FLOW THROUGH THIS PERIOD SHOULD BE NORTHERLY...WHICH IS SOMEWHAT
UNFAVORABLE FOR TSRA THAT DEVELOPS ON THE HIGHER TERRAIN IN NM AND CO
PROPAGATING THIS FAR E. GFS LAMP SHOWS BR AND LOW CEILINGS
REDEVELOPING AFTER 06Z...BUT THINK THIS IS UNLIKELY GIVEN LACK OF
SIGNIFICANT RAIN FALL OVER THE PAST DAY. IN ADDITION...THE TIME
HEIGHT DISPLAYS FOR BOTH THE GFS AND NAM SHOW LOW LEVEL RELATIVE
HUMIDITY VALUES WELL BELOW SATURATION DURING THIS TIME.
JOHNSON
PREV DISCUSSION... /ISSUED 306 AM CDT SUN SEP 30 2012/
DISCUSSION...
NORTHWESTERLY TO NORTH NORTHWESTERLY FLOW ALOFT TODAY WILL ALLOW FOR
SHORTWAVE ENERGY OVER THE CENTRAL ROCKIES TO APPROACH THE PANHANDLES
BETWEEN 18Z TODAY AND 00Z MONDAY. CONVECTION SHOULD DEVELOP THIS
AFTERNOON AND INTO THIS EVENING ACROSS THE MOUNTAINS AND HIGHER
TERRAIN OF SOUTHERN COLORADO AND NORTHERN NEW MEXICO AND TRACK
SOUTHEASTWARD INTO THE PANHANDLES. REMOVED MENTION OF PRECIP AND POPS
THIS MORNING AS RADIATIONAL COOLING FOG DEVELOPING ACROSS THE
FORECAST AREA...DENSE IN MANY LOCATIONS...AND SHOULD PREVAIL UNTIL
AROUND 15Z TO 16Z TODAY BEFORE LIFTING. THE DENSE FOG ADVISORY LOOKS
TO BE ON TRACK AND WILL CONTINUE ADVISORY UNTIL EXPIRATION. COLD
FRONT PUSHES THROUGH THE PANHANDLES LATE TONIGHT...AFTER 09Z TO 15Z
MONDAY...WITH A WIND SHIFT TO THE NORTH AND INCREASE IN SPEED. WIND
ADVISORY CRITERIA NOT EXPECTED AT THIS TIME...HOWEVER BREEZY TO WINDY
CONDITIONS EXPECTED MONDAY. MODELS IN GOOD AGREEMENT IN BRINGING DOWN
ANOTHER SHORTWAVE OUT OF WESTERN KANSAS AND EASTERN COLORADO MONDAY
MORNING ON NORTHERLY FLOW ALOFT. FAVORABLE JET DYNAMICS AND COLD
FRONT PUSHING THROUGH WILL ALLOW SHOWERS TO TRACK SOUTHWARD INTO
MAINLY THE EASTERN HALF OR TWO-THIRDS OF THE PANHANDLES MONDAY AND
THEN DRIER CONDITION MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK.
ANOTHER MUCH STRONGER COLD FRONT APPROACHES THE FORECAST AREA
WEDNESDAY NIGHT AND SHOULD MOVE THROUGH ALL OF THE PANHANDLES BY MID
MORNING THURSDAY. LOWERED TEMPERATURES FURTHER THURSDAY AND FRIDAY.
UPSLOPE SURFACE FLOW AND FAVORABLE ISENTROPIC LIFT BY FRIDAY NIGHT
INTO SATURDAY WILL RESULT IN INCREASED CHANCES FOR MAINLY SHOWERS
ACROSS MUCH OF THE PANHANDLES. WILL INTRODUCE POPS FRIDAY NIGHT AND
SATURDAY FOR SHOWERS AND POSSIBLE THUNDERSTORMS...MAINLY DURING THE
DAYTIME PERIOD.
SCHNEIDER
FIRE WEATHER...
ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED THROUGH
NEXT SATURDAY.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
09/08
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1150 AM CDT SUN SEP 30 2012
.UPDATE...
QUICK UPDATE TO REMOVE DENSE FOG WORDING FROM ZONES AND INCREASE POPS
THIS AFTERNOON AS A SHRTWV IN NRLY FLOW SHOULD INTERACT WITH A SFC
TROUGH TO PROMOTE SCT STORMS AFTER 19-20Z. LATEST RUC FCST SHOWS
1500-2000 J/KG OF UNCAPPED MLCAPE BY MID AFTERNOON...WITH OTHER
MODELS SHOWING SLIGHTLY LESS INSTABILITY. RELATIVELY WEAK BULK SHEAR
OF 25-30KTS COULD PROMOTE MINIMAL STORM ORGANIZATION...BUT LACKING
LOW LVL DRY AIR SHOULD LIMIT DOWNDRAFT POTENTIAL. HAIL UP TO QUARTER
SIZE AND AN ISOLATED 60 MPH DOWNDRAFT COULD BE POSSIBLE IN STRONGER
STORMS...BUT EXPECT MOST CONVECTION THAT DOES DEVELOP THIS AFTERNOON
TO REMAIN JUST UNDER SVR LIMITS.
SIMPSON
&&
.PREV DISCUSSION... /ISSUED 642 AM CDT SUN SEP 30 2012/
AVIATION...
FOR THE 12Z KAMA TAF...THINK THE THREAT OF FG REDUCING VISIBILITIES
TO AIRFIELD MINIMUMS IS MOSTLY OVER...THOUGH COULD SEE TEMPO MVFR
CONDITIONS OVER THE NEXT FEW HOURS. THE LIGHT SW WINDS HAVE HELPED
SCOUR OUT THE FG AND BRING IN SLIGHTLY DRIER AIR. THERE IS A SLIGHT
CHANCE...20 PERCENT...OF TSRA BETWEEN 18 AND 06Z...BUT THIS LOOKS
VERY UNLIKELY GIVEN LACK OF A SOURCE OF LOW LEVEL LIFT...AND
UNFAVORABLE MEAN FLOW TO BRING TSRA FROM ROCKIES THIS FAR E. GFS LAMP
SHOWS BR AND LOW CEILINGS REDEVELOPING TONIGHT...BUT THINK THIS IS
UNLIKELY GIVEN LACK OF SIGNIFICANT RAIN FALL OVER THE LAST 24 HOURS
PLUS SLIGHT DOWNSLOPE COMPONENT IN THE WINDS FOR MUCH OF THE TAF
PERIOD. IN ADDITION...THE TIME HEIGHT DISPLAYS FOR BOTH THE GFS AND
NAM SHOW LOW LEVEL RELATIVE HUMIDITY VALUES WELL BELOW SATURATION.
FOR THE 12Z KDHT AND KGUY TAFS...LOW CEILINGS AND FG SHOULD
INTERMITTENTLY AFFECT THE TAF SITES...ESPECIALLY KDHT...FOR THE NEXT
3 HOURS BEFORE DISSIPATING WITH INCREASED MIXING IN A TYPICAL DIURNAL
PATTERN. THERE IS A SMALL CHANCE...20 TO 30 PERCENT...OF TSRA BETWEEN
18 AND 06Z. FOR NOW HAVE LEFT MENTION OUT OF THE TAFS AS THE MEAN
FLOW THROUGH THIS PERIOD SHOULD BE NORTHERLY...WHICH IS SOMEWHAT
UNFAVORABLE FOR TSRA THAT DEVELOPS ON THE HIGHER TERRAIN IN NM AND CO
PROPAGATING THIS FAR E. GFS LAMP SHOWS BR AND LOW CEILINGS
REDEVELOPING AFTER 06Z...BUT THINK THIS IS UNLIKELY GIVEN LACK OF
SIGNIFICANT RAIN FALL OVER THE PAST DAY. IN ADDITION...THE TIME
HEIGHT DISPLAYS FOR BOTH THE GFS AND NAM SHOW LOW LEVEL RELATIVE
HUMIDITY VALUES WELL BELOW SATURATION DURING THIS TIME.
JOHNSON
PREV DISCUSSION... /ISSUED 306 AM CDT SUN SEP 30 2012/
DISCUSSION...
NORTHWESTERLY TO NORTH NORTHWESTERLY FLOW ALOFT TODAY WILL ALLOW FOR
SHORTWAVE ENERGY OVER THE CENTRAL ROCKIES TO APPROACH THE PANHANDLES
BETWEEN 18Z TODAY AND 00Z MONDAY. CONVECTION SHOULD DEVELOP THIS
AFTERNOON AND INTO THIS EVENING ACROSS THE MOUNTAINS AND HIGHER
TERRAIN OF SOUTHERN COLORADO AND NORTHERN NEW MEXICO AND TRACK
SOUTHEASTWARD INTO THE PANHANDLES. REMOVED MENTION OF PRECIP AND POPS
THIS MORNING AS RADIATIONAL COOLING FOG DEVELOPING ACROSS THE
FORECAST AREA...DENSE IN MANY LOCATIONS...AND SHOULD PREVAIL UNTIL
AROUND 15Z TO 16Z TODAY BEFORE LIFTING. THE DENSE FOG ADVISORY LOOKS
TO BE ON TRACK AND WILL CONTINUE ADVISORY UNTIL EXPIRATION. COLD
FRONT PUSHES THROUGH THE PANHANDLES LATE TONIGHT...AFTER 09Z TO 15Z
MONDAY...WITH A WIND SHIFT TO THE NORTH AND INCREASE IN SPEED. WIND
ADVISORY CRITERIA NOT EXPECTED AT THIS TIME...HOWEVER BREEZY TO WINDY
CONDITIONS EXPECTED MONDAY. MODELS IN GOOD AGREEMENT IN BRINGING DOWN
ANOTHER SHORTWAVE OUT OF WESTERN KANSAS AND EASTERN COLORADO MONDAY
MORNING ON NORTHERLY FLOW ALOFT. FAVORABLE JET DYNAMICS AND COLD
FRONT PUSHING THROUGH WILL ALLOW SHOWERS TO TRACK SOUTHWARD INTO
MAINLY THE EASTERN HALF OR TWO-THIRDS OF THE PANHANDLES MONDAY AND
THEN DRIER CONDITION MONDAY NIGHT THROUGH THE MIDDLE OF THE WEEK.
ANOTHER MUCH STRONGER COLD FRONT APPROACHES THE FORECAST AREA
WEDNESDAY NIGHT AND SHOULD MOVE THROUGH ALL OF THE PANHANDLES BY MID
MORNING THURSDAY. LOWERED TEMPERATURES FURTHER THURSDAY AND FRIDAY.
UPSLOPE SURFACE FLOW AND FAVORABLE ISENTROPIC LIFT BY FRIDAY NIGHT
INTO SATURDAY WILL RESULT IN INCREASED CHANCES FOR MAINLY SHOWERS
ACROSS MUCH OF THE PANHANDLES. WILL INTRODUCE POPS FRIDAY NIGHT AND
SATURDAY FOR SHOWERS AND POSSIBLE THUNDERSTORMS...MAINLY DURING THE
DAYTIME PERIOD.
SCHNEIDER
FIRE WEATHER...
ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS ARE NOT EXPECTED THROUGH
NEXT SATURDAY.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
09/08
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
259 PM CDT SUN SEP 30 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
259 PM CDT SUN SEP 30 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION POTENTIAL MONDAY
AFTERNOON/EVENING AND TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING NEAR THE U.S. WEST COAST...A SHORTWAVE TROUGH
DROPPING DOWN INTO SOUTH CENTRAL CANADA AND NORTH DAKOTA...UPPER
LOWS OVER THE SOUTHERN PLAINS AND NEW ENGLAND...AND RIDGING OVER THE
FORECAST AREA. OTHER THAN SOME CIRRUS STREAMING NORTHEAST ACROSS
IOWA AHEAD OF THE SOUTHERN PLAINS UPPER LOW...MOSTLY SUNNY SKIES
EXIST ACROSS MUCH OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER
VALLEY REGION. THIS IS DUE TO PLENTIFUL DRY AIR SEEN ON 12Z
SOUNDINGS FROM ABR...MPX AND GRB...WHERE DEWPOINT DEPRESSIONS OF 10C
OR MORE EXISTED THROUGHOUT MUCH OF THE TROPOSPHERE. AT THE
SURFACE...HIGH PRESSURE WAS SITUATED ACROSS THE GREAT LAKES WHILE A
COLD FRONT EXTENDED FROM THE MANITOBA/ONTARIO BORDER SOUTHWEST INTO
CENTRAL SOUTH DAKOTA. SHARP 850MB TEMPERATURE GRADIENT EXISTS
BETWEEN THESE TWO SURFACE FEATURES...NOTED BY 12Z SOUNDING DATA OF
15C AT INL AND MPX COMPARED TO 8C AT GRB. THIS HAS RESULTED IN A
SIMILAR SHARP GRADIENT IN CURRENT TEMPERATURES....FROM THE LOWER 80S
IN WESTERN MINNESOTA TO THE UPPER 60S IN EASTERN WISCONSIN.
TONIGHT AND MONDAY...SHORTWAVE TROUGH COMING INTO NORTH DAKOTA IS
PROGGED TO SPLIT APART INTO TWO BY THE 30.12Z GFS/UKMET/CANADIAN AND
ECMWF...WITH PART OF IT HEADING INTO NORTHWEST ONTARIO AND THE OTHER
DROPPING SOUTH INTO NEBRASKA BY LATE MONDAY. THIS SCENARIO CREATES
SOME ISSUES FOR PRECIPITATION TO OCCUR...SINCE THE UPPER LEVEL
FORCING GETS SPLIT AROUND THE FORECAST AREA. PLUS THE AIRMASS IS
QUITE DRY. ALL FOUR MODELS SUGGEST A DRY FORECAST. THE 30.00Z ECMWF
AND 30.12Z NAM ON THE OTHER HAND KEEP MOST OF THE TROUGH
TOGETHER....DROPPING IT INTO MN AND IA DURING THE AFTERNOON. AS
SUCH...STRONGER FORCING EXISTS AND A FRONTOGENETICAL BAND OF LIGHT
RAIN IS FORECAST TO MOVE INTO NORTHWEST SECTIONS OF THE FORECAST
AREA DURING THE AFTERNOON. HAVE FOLLOWED THE MAJORITY OF THE 30.12Z
GUIDANCE AND PULLED OUT PRECIPITATION CHANCES ENTIRELY. BOTH
SCENARIOS STILL HAVE THE COLD FRONT OVER THE EASTERN DAKOTAS SLIDE
INTO THE FORECAST AREA WITH SIMILAR TIMING...SLOWLY MOVING THROUGH
DURING THE COURSE OF THE DAY MONDAY. AS SUCH...THERE COULD BE SOME
SLIGHT COOLING IN SOUTHEAST MINNESOTA LATE IN THE DAY. OTHERWISE...
850MB TEMPS OF 10-12C AT 18Z MONDAY COMBINED WITH MID/HIGH CLOUD
COVER SHOULD SUPPORT HIGHS TOPPING OUT IN THE UPPER 60S TO LOW 70S.
ENOUGH HIGH CLOUDS AND A SOUTHERLY GRADIENT LOOKS TO BE IN PLACE
TONIGHT TO PRECLUDE ANY VALLEY FOG DEVELOPMENT. THEY SHOULD ALSO
RESULT IN WARMER LOWS...ESPECIALLY WEST OF THE MISSISSIPPI RIVER.
GOING PREVIOUS FORECAST LOWS LOOK REASONABLE...WITH THE TYPICAL
WISCONSIN COLD SPOTS DROPPING INTO THE UPPER 30S DUE TO A LONGER
PERIOD OF DECOUPLED WINDS.
MONDAY NIGHT AND TUESDAY...THE POSSIBLY SPLIT SHORTWAVE TROUGH LOOKS
TO MOVE THROUGH THE FORECAST AREA LATE MONDAY NIGHT...WITH RIDGING
BUILDING IN FROM THE WEST ON TUESDAY AS A POTENT UPPER TROUGH BEGINS
TO DROP SOUTH INTO MONTANA. AGAIN WHETHER OR NOT PRECIPITATION FALLS
MONDAY NIGHT DEPENDS ON HOW SPLIT APART THAT SHORTWAVE TROUGH IS...
WITH THE 30.00Z ECMWF DEPICTING A MUCH BETTER CHANCE OF RAIN
COMPARED TO THE 30.12Z NAM/GFS/UKMET/CANADIAN/ECMWF. CONTINUED TO
FOLLOW THE DRY MAJORITY AS WELL AS PREVIOUS DRY FORECAST.
STILL...AFTER 06Z TUESDAY...DRY WEATHER SHOULD BE THE RULE WITH
SKIES CLEARING OUT...ESPECIALLY OVER THE NORTHWESTERN 2/3 OF THE
AREA. TEMPERATURES SHOULD STILL REMAIN SEASONABLE MONDAY
NIGHT...DESPITE THE COLD FRONTAL PASSAGE...DUE TO A COMBINATION OF
THE CLOUDS AND 850MB TEMPS ONLY FALLING TO 6-8C BY 12Z TUESDAY.
GENERALLY FOLLOWED A BLEND OF GUIDANCE WHICH RESULTS IN LOWS IN THE
40S. WITH SUN BACK OUT FOR TUESDAY AND THE GIVEN 850MB TEMPS...HIGHS
REACHING UP INTO THE UPPER 60S TO LOW 70S SEEM REASONABLE.
TUESDAY NIGHT AND WEDNESDAY...THE POTENT UPPER TROUGHING DROPPING
INTO MONTANA ON TUESDAY IS PROGGED TO CONTINUE DIGGING SOUTHEAST...
INTO WYOMING AND PERHAPS THE DAKOTAS AS WELL BY 00Z THURSDAY. AS
THIS TROUGH DIGS...IT HELPS TO KICK OUT THE STALLED UPPER LOW IN THE
SOUTHERN PLAINS. MODEL TRENDS HAVE SHOWN A LOT OF RETROGRESSION THE
PAST COUPLE OF DAYS WITH THIS UPPER LOW...WHICH IS NOW SLATED TO
LIFT UP THROUGH LOWER MICHIGAN ON WEDNESDAY. A DEFORMATION
PRECIPITATION BAND ASSOCIATED WITH THIS UPPER LOW IS FORECAST BY THE
30.12Z NAM TO PERHAPS CLIP PORTIONS OF GRANT AND ADAMS COUNTIES ON
WEDNESDAY. THE NAM IS A WESTERN OUTLIER...WITH ALL OTHER MODELS
KEEPING THE BAND TRACKING NOT MUCH FARTHER WEST THAN THE CHICAGO
AREA. THEREFORE...HAVE DISCOUNTED THE NAM AT THIS TIME...AND WILL
FOLLOW THE MAJORITY SHOWING UPPER RIDGING HOLDING OVER THE FORECAST
AREA BETWEEN THE POTENT UPPER TROUGH AND UPPER LOW. SUBSIDENCE AND
DRY AIR UNDER THIS UPPER RIDGE IS EXPECTED TO RESULT IN DRY WEATHER
FOR THIS TUESDAY NIGHT AND WEDNESDAY PERIOD. DEPENDING ON CLOUD
COVER AND IF IT RAINS MONDAY NIGHT...COULD BE A CONCERN FOR VALLEY
FOG TUESDAY NIGHT...SINCE A SURFACE RIDGE OF HIGH PRESSURE SHOULD BE
IN PLACE. OTHERWISE...TEMPERATURES LOOK FAIRLY MILD FOR EARLY
OCTOBER WITH LOWS STILL IN THE 40S AND 850MB TEMPS OF 10-12C ON
WEDNESDAY BOOSTING HIGHS INTO THE LOW TO MID 70S.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
259 PM CDT SUN SEP 30 2012
IN THE MEAN...THE 30.12Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ALL
CONTINUE TO FORECAST A BIG CHANGE IN THE UPPER LEVEL PATTERN DURING
THE LONG TERM PERIOD. BY THE WEEKEND...THERE SHOULD BE DEEP UPPER
LEVEL TROUGHING IN PLACE ACROSS THE EASTERN TWO THIRDS OF CANADA AS
WELL AS THE NORTHERN PLAINS EASTWARD INTO THE GREAT LAKES. FALL WILL
REALLY BE FELT THIS WEEKEND AS 850MB TEMPS PLUMMET TO BELOW -2C.
PLENTY OF DIFFERENCES EXIST ON HOW WE GET TO THE WEEKEND...MOSTLY
RELATED TO THAT POTENT TROUGH THE DIGS INTO WYOMING ON WEDNESDAY.
THE 30.12Z ECMWF/CANADIAN/GFS ALL HAVE THE POTENT TROUGH TURNING
NEGATIVE TILT AS IT COMES ACROSS THE NORTHERN PLAINS INTO MINNESOTA
WEDNESDAY NIGHT AND THURSDAY. HOW FAR NORTHWEST THIS TURN TO
NEGATIVE TILT OCCURS AND TIMING IS AT ODDS AMONGST THE MODELS...WITH
THE 30.00Z ECMWF/30.12Z CANADIAN FARTHER TO THE NORTHWEST THAN THE
30.12Z GFS. THIS HAS MAJOR IMPLICATIONS ON HOW MUCH PRECIPITATION
AND COLD AIR TIMING. IN THE CASE OF THE 30.00Z ECMWF/30.12Z
CANADIAN...THEY ARE MUCH LIGHTER ON PRECIPITATION COMPARED TO THE
30.12Z GFS. NEW 30.12Z ECMWF IS COMPLETELY DRY. FOR NOW...WILL
FOLLOW A CONSENSUS APPROACH WITH 20 CHANCES WEDNESDAY NIGHT AND
30-50 ON THURSDAY. ALSO OF NOTE IS THE 30.12Z ECMWF/CANADIAN ARE
MUCH FASTER THAN THE GFS. MUCH COOLER DAY ANTICIPATED ON THURSDAY
TOO AS THE COLD FRONT PASSES...SENDING 850MB TEMPS DOWN TO 0-4C BY
00Z FRIDAY. BREEZY NORTHWEST WINDS LIKELY TOO BEHIND THE FRONT...
ESPECIALLY IF THE GFS PANS OUT. MAINLY DRY WEATHER SHOULD FOLLOW FOR
THURSDAY NIGHT. FOR FRIDAY AND SATURDAY...THE 30.00Z/30.12Z ECMWF
SHOW SOME FRONTOGENESIS-TYPE LIGHT RAIN OCCURRING ACROSS MUCH OF
THE FORECAST AREA...NORTH OF A STALLED BOUNDARY FROM KANSAS TO
INDIANA. THE 30.12Z GFS/CANADIAN HAVE THIS BOUNDARY MUCH FARTHER
SOUTH...RESULTING IN DRY CONDITIONS. GIVEN THE GENERALLY GOOD
PERFORMANCE OF THE ECMWF...NEED TO HAVE AT LEAST SOME 20 PERCENT
CHANCES FOR FRIDAY AND SATURDAY...ESPECIALLY SOUTH OF I-90. ALL
MODELS HAVE HIGH PRESSURE CROSSING THE AREA ON SUNDAY...THUS DRIER
WEATHER IS EXPECTED.
&&
.AVIATION...THIS AFTERNOON THROUGH MONDAY
1215 PM CDT SUN SEP 30 2012
HIGH PRESSURE AND LIGHT EAST TO SOUTHEAST WIND FLOW WILL KEEP A DRY
AIRMASS AND GOOD VFR CONDITIONS OVER THE AREA THIS AFTERNOON AND
TONIGHT. AN APPROACHING MID LEVEL TROUGH WILL SPREAD INCREASING MID
AND HIGH LEVEL MOISTURE ACROSS THE AREA TONIGHT AND TUESDAY. SCT-BKN
CIRRUS THIS AFTERNOON AND EVENING WILL GIVE WAY TO SCT-BKN 8K TO 12K
MID CLOUDS LATE TONIGHT/MON AS THE MID LEVEL TROUGH/SHORTWAVE
APPROACHES AND MOVES ACROSS THE AREA. THERE MAY BE WDLY SCT -SHRA
AROUND THE AREA LATER MON MORNING INTO MON AFTERNOON BUT GIVEN
UNCERTAINTY AND THE DRIER SFC-8K FT AIRMASS BELOW THE MOISTURE AND
MID LEVEL LIFT...LEFT VCSH OUT OF THE LATE PORTIONS OF THE TAFS FOR
NOW. PASSAGE OF THE SFC FRONT WILL SWITCH THE WINDS FROM SOUTH AHEAD
OF IT TO NORTHWEST BEHIND IT...AROUND 14Z MON AT KRST AND AROUND 18Z
MON AT KLSE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
259 PM CDT SUN SEP 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RRS