Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/05/12
AREA FORECAST DISCUSSION
NWS ALBANY NY
749 PM EDT THU OCT 4 2012
.SYNOPSIS...
A FRONTAL BOUNDARY AND UPPER LEVEL DISTURBANCE WILL PASS THROUGH THE
REGION THIS EVENING...BRINGING AN END TO THE SHOWERS. WEAK HIGH
PRESSURE WILL BUILD INTO OUR AREA OVERNIGHT...BEFORE SHIFTING SOUTH
AND EAST FRIDAY MORNING. A SERIES OF COLD FRONTS WILL MOVE INTO THE
REGION FROM LATE FRIDAY THROUGH THE WEEKEND...RESULTING IN PERIODIC
UNSETTLED WEATHER AND COOLING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 7 PM...RAIN WAS DEPARTING LITCHFIELD COUNTY WHERE DUAL POL
RADAR RAINFALL ESTIMATES SUGGEST 1-3 INCHES OF RAIN HAS FALLEN
ACROSS PORTIONS OF DUTCHESS AND LITCHFIELD COUNTIES. SATELLITE
IMAGERY SUGGESTS A RAPID CLEARING IS TAKING PLACE FROM WEST TO
EAST WHICH WILL PLACE AN INCREASING POTENTIAL FOR FOG FORMATION.
WINDS ARE EXPECTED TO DECOUPLE AND WITH VERY MOIST GROUND SHOULD
ALLOW FOR PATCHY DENSE FOG TO FORM. WE WILL WATCH TRENDS CLOSELY
AND MAKE ADJUSTMENTS AS NEEDED INCLUDING HEADLINE POTENTIAL FOR
FOG.
AS OF 443 PM...QUICK UPDATE TO ADD MENTION OF ISOLATED THUNDER TO
SOUTHERN PORTIONS OF THE MID HUDSON VALLEY AND SOUTHERN
BERKSHIRE/LITCHFIELD COUNTIES...AS A FEW CLOUD TO GROUND LIGHTNING
STRIKES HAVE BEEN DETECTED ASSOCIATED WITH SOME LOW TOPPED
CONVECTIVE CELLS. SBCAPE FROM SPC RUC ANALYSIS SHOWING AROUND
250-500 J/KG IN THIS LIMITED AREA...WHICH IS SUPPORTING SOME
ISOLATED THUNDER.
DEEP MOISTURE PLUME ALONG THE EASTERN SEABOARD WITH CONNECTION TO
THE GULF OF MEXICO STILL EVIDENT ON WATER VAPOR IMAGERY LATE THIS
AFTERNOON. A WEAKENING UPPER LEVEL TROUGH IS NOW MOVING THROUGH
WESTERN PA/NY AND WILL CONTINUE TO PRESS EASTWARD AND ALSO SHIFT
THE DEEP MOISTURE PLUME OFF TO OUR EAST THIS EVENING. AT THE
SURFACE...A WEAKLY DEFINED FRONTAL BOUNDARY IS MOVING THROUGH
CENTRAL NY AT THIS TIME...AND IS MORE OF A DEWPOINT BOUNDARY THAN
THERMAL BOUNDARY.
SO UNTIL THESE FEATURES MOVE THROUGH DURING THE EVENING...FAIRLY
WIDESPREAD SHOWERS WILL CONTINUE MAINLY ALONG A LINE FROM THE UPPER
HUDSON VALLEY/CAPITAL DISTRICT/EASTERN CATSKILLS EASTWARD...WITH
ONLY A FEW SHOWERS TO THE NORTH AND WEST OF THIS LINE. WITH THE DEEP
MOISTURE AND HUMID CONDITIONS...THERE COULD BE SOME BRIEF DOWNPOURS
UNTIL THE SHOWERS END.
SKIES WILL LIKELY CLEAR FROM WEST TO EAST THIS EVENING...HOWEVER
DUE TO SIGNIFICANT RESIDUAL LOW LEVEL MOISTURE IN PLACE FOG WILL
FORM AND WILL BE DENSE IN SPOTS. TEMPS WILL BE COOLER THAN RECENT
NIGHTS...WITH DEWPOINTS DROPPING INTO THE 50S AS OPPOSED TO 60S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
FRIDAY SHOULD END UP BEING THE WARMEST DAY OF THE WEEK ONCE FOG/LOW
STRATUS CLOUDS BURN OFF DURING THE MORNING. BETTER MIXING AND A
DRIER AIR MASS IN PLACE SHOULD RESULT IN SOME SUNSHINE. WITH WARM
AIR ALOFT AROUND +12C AT 850MB IN PLACE ACROSS THE REGION...TEMPS
SHOULD RESPOND TO SUNSHINE AND MIXING AND A SOUTHWEST FLOW BY
WARMING INTO THE MID 70S IN MOST VALLEY LOCATIONS...WITH UPPER 70S
SOUTH OF THE CAPITAL REGION. IT WILL BE COOLER TOWARDS THE WESTERN
ADIRONDACKS...AS A WEAKENING FRONTAL BOUNDARY AND INCREASING CLOUDS
APPROACH DURING THE AFTERNOON.
THIS INITIAL DECAYING FRONT SHOULD ONLY RESULT IN ISOLATED TO
SCATTERED SHOWERS MAINLY NORTH AND WEST OF THE CAPITAL REGION FRIDAY
AFTERNOON INTO FRIDAY EVENING. HOWEVER...A SECONDARY COLD FRONT WILL
BE FAST ON ITS HEELS AND MOVE INTO THE AREA LATE FRIDAY NIGHT. WITH
A WEAK RIPPLE OF LOW PRESSURE EXPECTED TO DEVELOP ALONG THE
FRONT...ITS PROGRESS WILL SLOW AND MOST OF THE RAIN ASSOCIATED WITH
THIS SYSTEM WILL FALL ALONG OR BEHIND THE FRONT. AGAIN...IT APPEARS
THAT THIS BOUNDARY WILL SET UP OVER OR JUST NORTHWEST OF THE CAPITAL
REGION...SO THIS IS WHERE THE HIGHEST POPS HAVE BEEN FORECAST LATE
FRIDAY NIGHT THROUGH SATURDAY MORNING. TO THE SOUTH AND EAST...WILL
MENTION ONLY SLIGHT CHANCE TO CHANCE POPS.
TEMPERATURES ON SATURDAY WILL BE TRICKY AND COULD VARY QUITE A BIT
ACROSS THE AREA DUE TO THE SLOW MOVING COLD FRONT NOT REACHING AREAS
SOUTHEAST OF ALBANY UNTIL LATE IN THE DAY. FROM ALBANY NORTH AND
WEST TEMPS WILL BE MUCH COOLER THAN FRIDAY...ONLY REACHING THE MID
50S TO LOWER 60S. HOWEVER...SOUTH AND EAST OF THE FRONT...MID TO
UPPER 60S ARE POSSIBLE. IN GENERAL...MOST SOURCES OF MODEL GUIDANCE
HAVE BEEN TRENDING SLOWER WITH THE FRONTAL PASSAGE SINCE YESTERDAY.
WILL MENTION SCATTERED SHOWERS SPREADING SOUTHEASTWARD ASSOCIATED
WITH COLD FRONT SATURDAY AFTERNOON.
ANOTHER BRIEF DRY PERIOD IS EXPECTED SATURDAY NIGHT AS A SMALL AND
WEAK AREA OF HIGH PRESSURE BUILDS IN. HOWEVER...CLOUDS WILL LIKELY
INCREASE LATE SATURDAY NIGHT...WHICH SHOULD PRECLUDE ANY FROST
FORMATION DESPITE MUCH COLDER TEMPERATURES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
A RATHER ACTIVE PERIOD OF WEATHER FOR THE REGION AS RATHER LARGE
THERMAL PATTERN CHANGES WILL OCCUR...WITH PERHAPS A LITTLE SNOW FOR
THE HIGHEST TERRAIN.
A LARGE RIDGE AXIS WILL DEVELOP OVER THE NORTHERN PACIFIC OCEAN
WHICH WILL RUN ALONG THE BRITISH COLUMBIA COASTLINE.
MEANWHILE...DOWNSTREAM TROF IS EXPECTED TO AMPLIFY AS THE HUDSON BAY
LOW EVOLVES. ONE PIECE OF POTENT ENERGY IS EXPECTED TO DIVE
SOUTHWARD ALONG THE ROCKIES AND ENTER INTO THE CONFLUENCE OVER THE
CENTER OF THE NATION AND BEGIN TO INTERACT WITH AN INCREASING
BAROCLINIC ZONE OVER THE MID WEST. THIS WILL SET THE STAGE FOR AN
UNFOLDING PRECIP EVENT FOR THE REGION ON SUNDAY. GLOBAL MODELS AND
ASSOCIATED ENSEMBLES REFLECT THAT A WEAK SURFACE WAVE WILL DEVELOP
WITHIN THE REGION OF MID-UPPER LEVEL DIVERGENT Q-VECTORS OVER THE
EASTERN OHIO VALLEY. WE WILL INCREASE POPS BUT KEEP THOSE VALUES
BELOW LIKELY THRESHOLDS AS SOME TIMING DIFFERENCES DO REMAIN. 850MB
TEMPS IN THE WAKE OF THIS SYSTEM DROP BACK AT OR BELOW 0C WHERE SOME
OF THE HIGHER TERRAIN COULD SEE A LITTLE BIT OF THE WHITE BUT NO
ACCUMULATIONS EXPECTED.
THEREAFTER...A LARGE AND ELONGATED REGION OF HIGH PRESSURE WILL MOVE
IN FROM THE MID-LOWER MISSISSIPPI RIVER VALLEY AND INTO NEW ENGLAND
FOR THE START OF THE WEEK. THIS WILL MODIFY THE THERMAL PROFILES
WITH A WARMING TREND AS THOSE 850MB TEMPS CLIMB BACK INTO THE MID
SINGLE DIGITS.
HOWEVER...AS THE HUDSON BAY LOW REMAINS IN PLACE...ANOTHER SHORT
WAVE IS FORECAST TO DIVE FROM CENTRAL CANADA AND INTO THE NORTHERN
TIER OF THE COUNTRY FOR THE MID WEEK PERIOD. THIS WILL SET THE
STAGE FOR ANOTHER OVERRUNNING EVENT WITH MANY ENSEMBLES IN
AGREEMENT. SO WILL INCREASE POPS ONCE AGAIN ALONG WITH MODERATING
TEMPERATURES.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
IFR CONDITIONS TO PREVAIL THROUGH TONIGHT WITH EVEN LIFR/VLIFR
POTENTIAL OVERNIGHT AS DROPPING CIGS/VIS DUE TO NEAR IDEAL
PARAMETERS FOR FOG FORMATION.
CONDITIONS SHOULD IMPROVE THROUGH FRIDAY MORNING AS BOUNDARY LAYER
WINDS INCREASE FOR VFR CONDITIONS TO RETURN. HIGH AND MID LEVEL
CLOUDS WILL INCREASE IN ADVANCE OF THE NEXT FRONTAL BOUNDARY
WILL BE APPROACHING.
OUTLOOK...
SAT-MON...VFR...MVFR/IFR POSS WITH CHC -SHRA.
TUE...VFR. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE EXPECTED WITH WET/SOGGY GROUND
CONDITIONS PERSISTING. A FRONTAL BOUNDARY AND UPPER LEVEL
DISTURBANCE WILL PASS THROUGH THE REGION THIS EVENING...BRINGING AN
END TO THE SHOWERS. WEAK HIGH PRESSURE WILL BUILD INTO OUR AREA
OVERNIGHT...BEFORE SHIFTING SOUTH AND EAST FRIDAY MORNING. A SERIES
OF COLD FRONTS WILL MOVE INTO THE REGION FROM LATE FRIDAY THROUGH
THE WEEKEND...RESULTING IN PERIODIC UNSETTLED WEATHER AND COOLING
TEMPERATURES.
&&
.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5
DAYS...ALTHOUGH UNSETTLED AND WET WEATHER WILL CONTINUE.
ADDITIONAL RAINFALL AMOUNTS THIS EVENING WILL RUN FROM AROUND ONE
TENTH TO ONE QUARTER INCH MAINLY FROM THE CAPITAL REGION SOUTH AND
EAST...WITH SOME ISOLATED AMOUNTS OF UP TO ONE HALF INCH WHERE A FEW
PERSISTENT DOWNPOURS OCCUR. RUNOFF FROM THE RAINFALL TODAY AND THIS
EVENING WILL GENERALLY RESULT IN RISES OF UP TO TWO FEET ON MAIN
STEM RIVERS.
A BREAK IN THE RAINFALL WILL OCCUR TONIGHT THROUGH FRIDAY
MORNING...BEFORE ADDITIONAL SHOWERS MOVE BACK ASSOCIATED WITH
ANOTHER FRONTAL BOUNDARY LATE FRIDAY THROUGH SATURDAY. RAINFALL
AMOUNTS SHOULD BE GENERALLY LIGHT DURING THIS TIME...AROUND ONE
TENTH TO ONE THIRD OF AN INCH...WITH THE HIGHER AMOUNTS NORTH AND
WEST OF ALBANY.
ANOTHER BREAK IS EXPECTED SATURDAY NIGHT INTO SUNDAY
MORNING...BEFORE MORE RAINFALL MOVES BACK IN SUNDAY AFTERNOON AND
NIGHT ASSOCIATED WITH A DEVELOPING LOW PRESSURE SYSTEM. THIS SYSTEM
MAY BRING GREATER RAINFALL AMOUNTS...BUT SHOULD GENERALLY BE LESS
THAN AN INCH.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...JPV
NEAR TERM...BGM/JPV
SHORT TERM...JPV
LONG TERM...BGM
AVIATION...IAA/IRL/BGM
FIRE WEATHER...JPV
HYDROLOGY...JPV
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
941 AM EDT WED OCT 3 2012
.SYNOPSIS...
A FEW SHOWERS ARE POSSIBLE THROUGH TONIGHT...BUT A BETTER CHANCE
OF SHOWERS EXISTS THURSDAY AFTERNOON AND EVENING WITH A COLD
FRONT. DRY WEATHER FOLLOWS FRIDAY. ANOTHER COLD FRONT MOVES
THROUGH THE REGION ON SATURDAY...WHICH WILL LIKELY BE FOLLOWED BY
A PERIOD OF RAIN SOMETIME SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
940 AM UPDATE...
FORECAST ON TRACK. EXPECT CLOUDS/FOG/DRIZZLE TO PERSIST THROUGH
MIDDAY...BUT CLOUDS WILL REMAIN LOCKED IN THROUGH AFTERNOON WITH
PLENTY OF LOW LEVEL MOISTURE AND LIGHT WINDS /N INLAND AND E-NE
NEAR COAST/.
RADAR MOSAIC SHOWS BATCH OF SHOWERS LIFTING NE FROM NJ WHICH
SHOULD REACH CT VALLEY AROUND MIDDAY. 3KM HRRR SHOWS ONLY
SCATTERED SHOWERS AT BEST THIS AFTERNOON...PRIMARILY S OF MASS
PIKE.
FORECAST HIGHS ON TRACK. STILL CONCERNED 70S MAY BE A STRETCH
INLAND GIVEN CLOUD COVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...
UPPER LEVEL RIDGING FROM THE ATLANTIC WILL CONTINUE TO
NOSE INTO SOUTHERN NEW ENGLAND. THIS SHOULD PREVENT WIDESPREAD
PRECIPITATION IN OUR REGION. HOWEVER...WARM ADVECTION AND DEEP
MOISTURE MAY RESULT IN A FEW SHOWERS AT TIMES BUT A WASHOUT IS NOT
EXPECTED. WILL RUN WITH SOME CHANCE POPS. WE ALSO EXPECT TO SEE
MORE AREAS OF FOG AND PATCHY DRIZZLE GIVEN DEEP LOW LEVEL MOISTURE.
LOW TEMPERATURES SHOULD ONLY FALL INTO THE UPPER 50S TO AROUND 60 IN
MOST LOCATIONS GIVEN CLOUD COVER AND LOW LEVEL MOISTURE.
THURSDAY...
SCATTERED SHOWERS ARE POSSIBLE ACROSS THE REGION THROUGH
EARLY AFTERNOON IN THE WARM ADVECTION PATTERN. A BETTER CHANCE OF
MORE WIDESPREAD PRECIPITATION WILL EXIST FROM THE MID AFTERNOON INTO
THE EVENING HOURS. THIS IN RESPONSE TO A STRONG SHORTWAVE LIFTING
ACROSS NEW ENGLAND AND AN ASSOCIATED WAVE OF LOW PRESSURE. ENOUGH
CONFIDENCE TO WARRANT SOME LIKELY TO LOW END CATEGORICAL POPS FOR AT
LEAST A FEW HOURS ACROSS A GOOD PORTION OF THE REGION. HIGHEST POPS
WILL BE IN OUR NORTHWEST ZONES WHERE THE BETTER DYNAMICS RESIDE.
GIVEN HIGH PWAT VALUES...BRIEF HEAVY RAIN RAIN SHOWERS ARE ALSO A
POSSIBILITY. INSTABILITY IS LIMITED...BUT AN ISOLATED THUNDERSTORM
OR TWO CAN/T BE RULED OUT ACROSS OUR INTERIOR ZONES.
HIGH TEMPS ARE TRICKY AGAIN WITH ONSHORE FLOW ALONG THE COAST AND
CLOUD COVER. SIDED WITH THE COOLER GUIDANCE AND WENT WITH HIGHS
MAINLY IN THE UPPER 60S TO THE LOWER 70S FOR NOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
* DRY WEATHER FRIDAY
* FRONTAL SYSTEM WILL BRING RAIN FOR THE
WEEKEND
* DRY...COOL WEATHER RETURNS EARLY NEXT WEEK
00Z MODELS ARE IN REMARKABLY GOOD AGREEMENT THROUGH THE LONG TERM
FORECAST. A WEAK COLD FRONT/AREA OF LOW PRESSURE MOVES THROUGH
SOUTHERN NEW ENGLAND THURSDAY NIGHT...BRINGING MORE SHOWERS TO THE
AREA. LOW PRESSURE MOVES THROUGH QUEBEC FRIDAY WITH A COLD FRONT
MOVING THROUGH THE REGION LATE FRIDAY NIGHT INTO EARLY SATURDAY.
LOW PRESSURE BUILDS OUT OF THE CAROLINAS SATURDAY AND MOVES
NORTHEASTWARD OVER CAPE COD AND INTO THE MARITIMES SUNDAY BRINGING
ANOTHER SHOT OF RAIN TO SOUTHERN NEW ENGLAND. COOL...DRY WEATHER
RETURNS AS HIGH PRESSURE BUILDS INTO NEW ENGLAND.
DETAILS...
THURSDAY NIGHT...AN AREA OF LOW PRESSURE MOVES OVER CAPE COD
BRINGING ANOTHER ROUND OF SHOWERS TO SOUTHERN NEW ENGLAND DURING THE
EARLY PART OF THE NIGHT. AFTER MIDNIGHT...ANY REMAINING SHOWERS AND
CLOUDS MOVE OUT...LINGERING ON THE EAST COAST THE LONGEST. THERE IS
SOME MARGINAL INSTABILITY SO THUNDER IS POSSIBLE...PARTICULARLY
BEFORE MIDNIGHT.
FRIDAY...DRY DAY EXPECTED AHEAD OF A COLD FRONT THAT WILL MOVE
THROUGH THE REGION FRIDAY NIGHT. THIS WILL OCCUR AS LOW PRESSURE
MOVES THROUGH QUEBEC. EXPECT TEMPERATURES TO BE WELL ABOVE NORMAL
WITH 850MB TEMPS IN THE 10 TO 12 DEGREE RANGE.
SATURDAY AND SUNDAY...LOW PRESSURE IN THE CAROLINAS SATURDAY WILL
MOVE NORTHEASTWARD OVER CAPE COD AND INTO THE MARITIMES SUNDAY.
THIS WILL BRING RAIN TO SOUTHERN NEW ENGLAND...PARTICULARLY SATURDAY
NIGHT AND SUNDAY. SOUTHWESTERLY FLOW AT THE MID AND UPPER LEVELS
WILL DRAW MOISTURE UP FROM THE GULF OF MEXICO. PWATS ARE HIGH...IN
THE INCH TO INCH AND A HALF RANGE. THIS WILL LEAD TO PERIODS OF
HEAVY RAIN.
MONDAY AND TUESDAY...HIGH PRESSURE BUILDS INTO THE REGION BRINGING
DRY...COOL WEATHER. TEMPERATURES WILL DROP SLIGHTLY BELOW NORMAL.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW... MODERATE CONFIDENCE. IFR/LIFR PERSISTS THROUGH MIDDAY
BEFORE IMPROVING TO MVFR CIGS THIS AFTERNOON. MORE CONFIDENT ON
RETURN TO IFR/LIFR THIS EVENING THROUGH THU MORNING.
KBOS TAF...MODERATE CONFIDENCE. CIGS WILL HANG AROUND HIGHER END
OF IFR /OVC009/ THROUGH MIDDAY BUT MVFR CIGS SHOULD PREVAIL.
KBDL TAF...MODERATE CONFIDENCE. CIGS MAY REMAIN IFR THROUGH
AFTERNOON /OVC008/ BUT CONFIDENCE IS HIGHER ON CIGS LIFTING TO
MVFR.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... THURSDAY NIGHT...MODERATE
CONFIDENCE. MAINLY VFR. PERIODS OF MVFR/IFR IN -SHRA.
FRIDAY...HIGH CONFIDENCE. VFR.
SATURDAY AND SUNDAY...LOW TO MODERATE CONFIDENCE. PERIODS OF
MVFR/IFR IN RAIN/FOG...ESPECIALLY SATURDAY NIGHT AND SUNDAY.
&&
.MARINE...
HIGH CONFIDENCE THROUGH THURSDAY THAT WINDS AND SEAS WILL REMAIN
BELOW SCA THRESHOLDS WITH A RELATIVELY WEAK PRESSURE GRADIENT. MAIN
CONCERN FOR MARINERS WILL BE FOR AREAS OF FOG RESULTING IN POOR
VISIBILITIES...PARTICULARLY DURING THE OVERNIGHT THROUGH THE MID
MORNING HOURS.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
WINDS AND SEAS REMAIN BELOW SCA CRITERIA THROUGH THE PERIOD. WINDS
INCREASE LATE SATURDAY NIGHT/EARLY SUNDAY MORNING AS A COLD FRONT
APPROACHES THE WATERS. SHOWERS/FOG MAY LIMIT VISIBILITIES AT TIMES
THROUGHOUT THE PERIOD. FRIDAY LOOKS TO BE THE ONLY DAY THAT THIS
DOES NOT OCCUR.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/RLG
NEAR TERM...JWD
SHORT TERM...FRANK
LONG TERM...RLG
AVIATION...JWD
MARINE...FRANK/RLG
AREA FORECAST DISCUSSION
NWS NEW YORK NY
228 AM EDT WED OCT 3 2012
.SYNOPSIS...
A WARM FRONT WILL REMAIN JUST SOUTH OF THE AREA THROUGH WEDNESDAY
BEFORE DISSIPATING AND GIVING WAY TO A COLD FRONTAL PASSAGE ON
THURSDAY. HIGH PRESSURE THEN BUILDS TO OUR SOUTH THROUGH FRIDAY
NIGHT. A STRONGER COLD FRONT WILL MOVE ACROSS THE REGION THIS
WEEKEND WITH A DRY BUT UNSEASONABLY COOL AIR MASS TO FOLLOW NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
PATCHY DRIZZLE WITH AREAS OF FOG WILL BE THE MAIN WEATHER FEATURES
WITHOUT MUCH ADDITIONAL LOWERING OF TEMPERATURE OVERNIGHT INTO
EARLY WEDNESDAY MORNING. WARM FRONT SOUTH OF LONG ISLAND SHOWN BY
SOME FORECAST MODELS SUCH AS RUC AND NAM TO GO INTO EASTERN LONG
ISLAND AS DIAGNOSED FROM LOW LEVEL INCREASES OF DEWPOINTS AND
DECREASE IN LIFTED INDEX.
A LIGHT FLOW OVERNIGHT. THE LIGHT FLOW AND SATURATED LOW LEVELS
SHOULD ALSO ALLOW FOR AREAS OF FOG. SOME OF THIS FOG IS EXPECTED
TO BECOME LOCALLY DENSE AT TIMES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
EARLY MORNING FOG/DRIZZLE ON WED WILL GIVE WAY TO WIDELY SCATTERED
SHOWERS IN THE AFTERNOON...WITH THE POSSIBILITY OF AN ISOLATED
THUNDERSTORM NW OF NYC. MARGINAL INSTABILITY IS FORECAST AS
SURFACE DEW POINTS APPROACH 70. THE WARM FRONT WILL BE IN CLOSE
PROXIMITY..BUT FOR THE TIME WILL KEEP WINDS NE IN THE MORNING AND
THEN VEER THEM AROUND TO THE E/SE IN THE AFT. THE NAM WRF BRINGS
THE WARM FRONT ACROSS THE AREA TUE NIGHT AND KEEPS IT JUST NORTH
THROUGH ON WED. CONFIDENCE IS LOW IN THIS SCENARIO AND STAYED
WITH THE MODEL SUITE WHICH SUPPORTED THE GFS AND THE FARTHER SOUTH
SOLUTION.
WITH THE CLOSE PROXIMITY OF THE WARM FRONT WED/WED NIGHT...THERE
SHOULD BE PLENTY OF CLOUD COVER WITH WARM...MUGGY CONDITIONS.
PREFERRED THE SLIGHTLY COOLER MAV GUIDANCE...WITH HIGHS MID 70S
TO AROUND 80. THIS IS STILL WELL ABOVE NORMAL. NORMAL HIGHS ARE
AROUND 70.
THE UPPER FLOW FEATURES A HIGH AMPLITUDE RIDGE JUST OFF THE EAST
COAST...AND A DEEP TROUGH OVER THE LOWER MS VLY. THUS...THE
UNUSUAL WARMTH AND HUMIDITY.
EXPECT ANOTHER FOGGY NIGHT WED NIGHT WITH LIGHT ONSHORE WINDS AND
SATURATED LOW-LEVELS. THERE IS THE POTENTIAL FOR DENSE FOG.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE PERIOD STARTS WITH UNCERTAINTY OF WHERE THE SFC WARM FRONT WILL
BE THU MORNING. HAVE CONTINUED WITH A NON-NAM SOLN...KEEPING THE
BOUNDARY TO OUR S WITH A WAVE OF LOW PRES PASSING OVER OR JUST S OF
THE FORECAST AREA. RAIN WITH MUGGY CONDS AND AREAS OF FOG IN THE
MORNING WILL GRADUALLY GIVE WAY TO IMPROVING CONDS LATER IN THE
DAY AS THE LOW AND UPPER SHORTWAVE SLOWLY LIFTS TO THE NE AND HIGH
PRES BUILDS IN BEHIND IT.
UPPER PATTERN IS IN GOOD AGREEMENT ACROSS THE LOWER 48 THROUGH
FRI...WITH A NEARLY ZONAL FLOW WEST OF THE ROCKIES. PROBLEMS BEGIN
TO ARISE WITH THE NEXT LONGWAVE TROUGH DIGGING FROM THE PACIFIC NW
TO THE CENTRAL PLAINS THIS WEEKEND WITH LARGER DIFFERENCES IN
SHORTWAVE ENERGY ONCE IT MAKES IT TO THE NORTHEAST. THIS HAS
RESULTED IN DECREASED CONFIDENCE IN EXACT TIMING OF
PRECIPITATION...ESPECIALLY ON SAT AHEAD OF AND WITH COLD FROPA.
UPPER ENERGY AND LIFT IS LAGGING AND BOTH THE GFS AND EC ARE HINTING
AT MID ATLANTIC COASTAL LOW DEVELOPMENT AND INCREASING
FRONTOGENETIC FORCING DURING THE SAT NIGHT/SUN TIME PERIOD. SINCE
THE TIMING OF THE UPPER FEATURES ARE IN QUESTION...HAVE USED A
COMPROMISE OF THE UKMET/EC/GFS FOR THE WEEKEND AND ALTHOUGH THERE IS
A LONG DURATION OF POPS THIS WEEKEND...DON`T THINK IT WILL BE A
COMPLETE WASHOUT.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL THU AND FRI AND NEAR
NORMAL ON SAT WITH CLOUD COVER AND POSSIBLE SHOWERS. BEHIND THE
FRONT...IT WILL BE DRY BUT UNSEASONABLY COOL INTO EARLY NEXT
WEEK...WITH H85 TEMPS DROPPING TO NEAR 0C AND DAYTIME HIGHS
GENERALLY IN THE UPPER 50S TO LOWER 60S AND LOWS GENERALLY IN THE
40S...WHICH IS AROUND 10 DEGREES BELOW NORMAL FOR EARLY FALL.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT WILL REMAIN JUST SOUTH OF NYC AND LONG ISLAND
OVERNIGHT. BASED ON A WEAK WAVE EXPECTED TO MOVE SOUTH OF THE AREA
THROUGH DAYBREAK...THE EXPECTATION IS FOR THE WARM FRONT TO STAY
SOUTH OF THE TERMINALS TODAY INTO TONIGHT.
BASED ON ABOVE THINKING...LIFR/VLIFR CONDS IN -DZ THIS MORNING ARE
ONLY EXPECTED TO SLOWLY IMPROVE AFTER DAYBREAK. UNCERTAINTY EXISTS
TO WHAT EXTENT IMPROVEMENT OCCURS. DIURNAL HEATING SHOULD ALLOW
VSBY TO IMPROVE AS -DZ BECOMES MORE PATCHY. MODERATE CONFIDENCE
EXISTS IN IMPROVEMENT TO MVFR...OR POSSIBLY VFR ACROSS CITY
TERMINALS...THIS AFTERNOON.
IN TERMS OF CIGS...CONFIDENCE IS MODERATE IN MOIST LOW- LEVELS
UNDER A WEAK INVERSION ONLY ALLOWING IMPROVEMENT TO IFR OR LOW-
END MVFR. HIGHER CONFIDENCE IN IFR FOR EASTERN AND NORTHERN
TERMINALS...WITH MVFR FOR THE NYC/NJ TERMINALS.
IFR CONDS ARE LIKELY TO RETURN TOWARDS EVENING WITH
LIGHT ONSHORE WINDS AND ABUNDANT MOISTURE...WITH VLIFR CONDS
POSSIBLE AT THE COAST. INCREASING LIKELIHOOD FOR -DZ OR -SHRA
AHEAD OF NEXT WAVE TONIGHT.
LIGHT N/NE WINDS THIS MORNING...LIKELY BECOME SE THIS
AFTERNOON/EVENING AHEAD OF DEVELOPING LOW PRESSURE WAVE TO THE
SOUTH. LIGHT E/SE WINDS EXPECTED TONIGHT.
OUTLOOK FOR 06Z THU-SUNDAY...
.LATE TONIGHT...LIFR CONDS...POSSIBLY VLIFR...EXPECTED IN FOG AND
LOW STRATUS.
.THU...MORNING IFR/MVFR EXPECTED. IMPROVEMENT TO VFR POSSIBLE
BY AFTERNOON.
.THU NIGHT-FRI NIGHT...VFR.
.SAT...VFR...POSSIBLY LOWER IN SCT SHOWERS.
.SUN...VFR.
&&
.MARINE...
EXPECTING TRANQUIL CONDITIONS ON THE COASTAL WATERS WITH WEAK
PRESSURE GRADIENTS IN PLACE WITH SUB SCA CONDITIONS FORECAST THROUGH
WEDNESDAY NIGHT.
SCA CONDS ARE POSSIBLE BEHIND A STRONG COLD FRONTAL PASSAGE THIS
WEEKEND. OTHERWISE...TRANQUIL CONDITIONS ARE EXPECTED ON THE WATERS.
&&
.HYDROLOGY...
AN UPDATED RAINFALL GRAPHIC HAS BEEN POSTED INDICATING AMOUNTS
EXPECTED FOR THE REMAINDER OF THE NIGHT. IN GENERAL...A FEW
HUNDREDTHS IN THE CITY AND W...WITH A FEW TENTHS OUT E. LOCALLY
HIGHER AMOUNTS POSSIBLE ON LI IF THE WARM FRONT GETS CLOSER THAN
CURRENTLY FCST...BUT THE PROB IS LOW ATTM.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...24/DW
NEAR TERM...JMC/DW/JM
SHORT TERM...DW
LONG TERM...24
AVIATION...NV
MARINE...24/DW
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
737 PM EDT THU OCT 4 2012
.SYNOPSIS...
WEAK HIGH PRESSURE FROM THE SOUTHERN STATES WILL BUILD ACROSS THE
AREA TONIGHT AND REMAIN THROUGH FRIDAY. LOW PRESSURE WILL MOVE
ACROSS ONTARIO AND QUEBEC THIS WEEKEND. AN ASSOCIATED COLD FRONT
WILL CROSS THE MIDDLE ATLANTIC REGION LATE SATURDAY AFTERNOON AND
EVENING. A WAVE OF LOW PRESSURE WILL MOVE ALONG THE FRONT ON SUNDAY.
HIGH PRESSURE WILL BUILD BACK ACROSS THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
WE INCLUDED THE MENTION OF FOG EARLY ALONG THE IMMEDIATE COAST AND
COASTAL WATERS UNTIL THE FRONT CLEARS.
A MID LEVEL TROUGH EXTENDED FROM EASTERN ONTARIO TO THE CAROLINAS
THIS AFTERNOON. THE AXIS OF THE TROUGH IS FORECAST TO PASS OVERHEAD
THIS EVENING.
SOME SHOWERS AND POSSIBLE THUNDERSTORMS HAVE DEVELOPED RIGHT ALONG
THE FRONTAL BOUNDARY. THE LATEST HRRR HAS A GOOD TIMING DEPICTION
(EVEN IF THE EXTENT IS OVERDONE). GRIDS AND FCST HAVE BEEN UPDATED
TO REFLECT THIS THINKING. HOPEFULLY THIS WILL BE THE LAST TIME IN
2012 WE WILL HAVE TO TYPE THE FRONTAL BOUNDARY WILL REMOVE THE 70
PLUS DEW POINTS AS THE EVENING PROGRESSES. OTHERWISE REST OF FCST
KEPT PRETTY MUCH THE SAME AS CLOUDS ARE DECREASING RAPIDLY OVER
EASTERN PA.
HIGH PRESSURE IS FORECAST TO NOSE UP INTO OUR REGION FROM THE
SOUTHWEST FOR TONIGHT. AS A RESULT, A MOSTLY CLEAR SKY IS EXPECTED
ALONG WITH A LIGHT WIND, MAINLY FROM THE WEST. TEMPERATURES SHOULD
DROP INTO THE 50S AND LOWER 60S IN OUR REGION. WITH THE LIGHT WIND
AND THE RECENT RAIN AND HUMIDITY, SOME PATCHY FOG IS ANTICIPATED
FOR LATE TONIGHT, MAINLY OUTSIDE OF URBAN AREAS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
THE AREA OF HIGH PRESSURE WILL CONTINUE TO INFLUENCE OUR REGION ON
FRIDAY. A MOSTLY SUNNY SKY IS EXPECTED ALONG WITH A WEST TO
SOUTHWEST WIND AROUND 5 TO 10 MPH.
WITH A WEST SOUTHWEST FLOW ALOFT, TEMPERATURES ARE EXPECTED TO BE
AROUND +12C AT 850 HPA RESULTING IN ANOTHER MILD DAY. AFTERNOON
TEMPERATURES AT THE SURFACE SHOULD BE ABOUT 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
THE WEAK UPPER AND SFC RIDGING ACROSS THE AREA FRI NIGHT WILL MOVE
QUICKLY TO THE EAST DURING SATURDAY. AN ONGOING PATTERN CHANGE
ALOFT WILL BRING LOWER H5 HEIGHTS ACROSS THE GREAT LAKES AS DEEP LOW
PRESSURE MOVES ACROSS ONTARIO AND QUEBEC THIS WEEKEND. THIS
PATTERN CHANGE WILL ARRIVE ACROSS OUR AREA IN THE FORM OF A COLD
FRONT DURING SATURDAY. ORGANIZED PCPN AHEAD OF THE FRONT...TO OUR
WEST...EARLY SATURDAY FALLS APART AS THE FRONT SEEMS TO OUTRUN THE
DEEPER MOISTURE. POPS WERE HELD IN THE CHC RANGE FOR SAT AT THIS
POINT. THE BETTER CHC WILL BE ACROSS THE WRN AREAS DURING THE
FIRST PART OF THE DAY. FURTHER EAST AND SOUTH...WE WILL KEEP ONLY
SLGT CHC POPS FOR SAT THEN CHC POPS FOR SAT NIGHT. SAT WILL BE THE
LAST ABOVE NORMAL TEMPERATURE DAY FOR AWHILE WITH SOME MID 70S
ACROSS SRN NJ AND THE DELMARVA. FURTHER NORTH AND WEST HIGHS MAY
ONLY REACH THE MID 60S WITH MORE CLOUDS EXPECTED.
COLDER AIR WILL SWEEP ACROSS THE AREA SAT NIGHT AND REMAIN INTO
EARLY NEXT WEEK. HIGHS ON SUNDAY WILL BE NOTICEABLY COLDER WITH
HIGHS IN THE 50S IN MOST AREAS WITH PERHAPS A FEW LOW 60S OVER THE
DELMARVA AREA. THESE READINGS WILL BE 5 TO 10 DEGREES BELOW NORMAL
FOR EARLY OCTOBER. A BATCH OF RAIN WILL ACCOMPANY A WAVE OF LOW
PRESSURE WHICH WILL RIDE ALONG THE FRONT SUN. LOW LIKELY POPS WILL
BE KEPT IN THE FCST FOR SUNDAY WITH THIS FEATURE. QPF COULD BE
1/4 TO 1/2 INCH.
DRIER AIR AND HIGH PRESSURE WILL RETURNS EARLY NEXT WEEK.
TEMPERATURES WILL BE MUCH BELOW NORMAL AT THE BEGINNING OF THE WEEK
WITH READINGS MODERATING BY WEDNESDAY. LOW TEMPERATURES ACROSS THE
SOUTHERN POCONOS AND NORTHERN NEW JERSEY MAY BE COLD ENOUGH FOR
SOME FROST MONDAY AND TUESDAY MORNINGS. ITS TOO EARLY TO TELL
WHETHER IT WILL BE WIDESPREAD OF JUST PATCHY...SOMETHING TO WATCH
OVER THE NEXT FEW DAYS. FURTHER SOUTH...LOWS MONDAY MORNING WILL
BE CLOSE TO 40 DEGREES.
THE HIGH WILL REMAIN ACROSS THE AREA MON AND TUE THEN ANOTHER LOW
AND ASSOCIATED FRONT WILL CROSS THE AREA WEDNESDAY. CHC POPS WERE
INSERTED ACROSS THE NORTHERN AND WESTERN AREAS FOR NOW.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE 00Z TAFS CONTAIN SOME MVFR CONDITIONS FORECAST FOR THIS
EVENING AT OUR EASTERN TERMINALS AND THEN MAINLY MVFR AT OUR MORE
RURAL TERMINALS AROUND SUNRISE FRIDAY.
THE COLD FRONT HAS YET TO CLEAR KACY AND KMIV, SOME PATCHY (EVEN
DENSER AT THE COAST) MVFR FOG IS FORECAST UNTIL THE FRONT CLEARS
THEM BY 02Z. OVERNIGHT SKIES ARE FORECAST TO BE CLEAR AT ALL OF
THE TERMINAL SITES AND ANY NORTHWEST WINDS SHOULD AVERAGE FIVE
KNOTS OR LESS. SO ITS ONE OF THOSE UNEASY SCENARIOS WHERE DRIER AIR
IS MOVING IN, BUT NOT WITH ENOUGH WIND TO REMOVE CONCERNS ABOUT
SOME FOG FORMING. THEREFORE WE HAVE CONTINUED THE MENTION OF MVFR
CONDITIONS AT THE MORE RURAL, OUTLYING TERMINALS AND ALSO KEPT
SOME IFR CONDITIONS AROUND SUNRISE AT KRDG.
WITH CLEAR SKIES ABOVE, THE FOG WHERE IT DOES FORM WILL BURN OFF
MUCH QUICKER THAN WEDNESDAY MORNING AND WE EXPECT VFR CONDITIONS
BY 13Z. THE FORECAST CONVECTIVE TEMPERATURE ON FRIDAY IS FAIRLY
HIGH, SO WE ARE ONLY FORECASTING A FEW CUMULUS CLOUDS TO FORM.
WINDS ARE EXPECTED TO BE FROM THE WEST AROUND 10KT. LATER IN THE
DAY MESOSCALE MODELS ARE FORECASTING A BAY BREEZE TO FORM (BUT NOT
GET TO KILG), OTHERWISE THE SEA BREEZE IF IT DOES FORM LATE SHOULD
NOT GET OFF THE COAST (AS IN WESTWARD) BY MUCH IF AT ALL. IF
ANYTHING THE MODELS ARE SUGGESTING THE OVERALL WINDS SHOULD JUST
BACK TO THE SOUTHWEST LATE IN THE DAY AS REFLECTED IN SOME OF OUR
SOUTHEASTERN TERMINALS.
OUTLOOK...
FRI NIGHT THRU SAT NIGHT...MOSTLY VFR WITH A FEW SCATTERED SHOWERS
LATER SATURDAY.
SUN-SUN NIGHT...POOR CONDITIONS EXPECTED WITH MVFR AND POSSIBLY
SOME IFR AT TIMES.
MON-TUE...MOSTLY VFR.
&&
.MARINE...
A FRONTAL BOUNDARY FROM THE WEST IS FORECAST TO REACH THE COASTAL
WATERS OF NEW JERSEY AND DELAWARE DURING THE LATE AFTERNOON AND
EVENING HOURS. HIGH PRESSURE WILL FOLLOW FOR TONIGHT AND FRIDAY.
WIND SPEEDS AND WAVE HEIGHTS WILL REMAIN BELOW THE SMALL CRAFT
ADVISORY CRITERIA DURING THE PERIOD
OUTLOOK...
SUB-SCA CONDITIONS FOR THE MOST PART. A COLD FRONT WILL BRING SOME
GUSTY WINDS AND HIGHER SEAS SAT NIGHT INTO SUNDAY. MARGINAL SCA
CONDITIONS POSSIBLE THEN.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...O`GIGI/IOVINO
SHORT TERM...IOVINO
LONG TERM...O`HARA
AVIATION...O`GIGI/O`HARA
MARINE...IOVINO
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
330 PM EDT WED OCT 3 2012
.DISCUSSION...
CURRENTLY...
DIURNAL CONVECTION STRUGGLING TO GET STARTED OVER THE CWA THIS
AFTN...DUE IN PART TO SLIGHTLY DRIER AND MORE STABLE AIR ADVECTING
IN FROM THE S. LATEST RAP ANALYSIS SHOWS A MID LVL VORT MIN PARKED
BTWN LAKE OKEECHOBEE AND CAPE CANAVERAL EMBEDDED WITHIN DEEP SRLY
FLOW. MEANWHILE...A SLUG OF DRY LOW/MID LVL AIR IS NUDGING UP FROM S
FL UNDERNEATH AN UPR LVL AIRMASS THAT IS WEAKLY CONVERGENT...AXIS OF
THE H85-H70 THETA-E MINIMUM HAS WORKED ITS WAY UP FROM THE FL
STRAITS INTO THE LAKE OKEECHOBEE REGION. MOISTURE AND DYNAMIC LIFT
ACRS THE NRN CWA ARE MORE FAVORABLE FOR PRECIP...BUT CONTINUES UNDER
THE VEIL OF A MID/UPR LVL CLOUD DECK THAT IS HAMPERING SFC HEATING
AND LOW LVL DESTABILIZATION.
TONIGHT...
THE FCST QUANDARY...AREAS WHERE MOISTURE EXISTS ARE PLAGUED BY
DEBRIS CLOUDS...AND AREAS FREE OF DEBRIS CLOUDS HAVE DIMINISHING
MOISTURE. OVERALL MOISTURE AND INSTABILITY REMAINS TOO HIGH TO
COMPLETELY SUPPRESS DIURNAL PRECIP...BUT WILL NEED MESOSCALE BNDRY
INTERACTION AS A TRIGGER MECHANISM. THESE WILL BE IN THE FORM OF THE
EAST COAST SEA BREEZE AND OUTFLOW BNDRYS FROM THE CONVECTION OVER
THE WEST PENINSULA.
SHOULD SEE CONVECTION FIRE S OF THE I-4 CORRIDOR BY LATE AFTN.
HOWEVER...GIVEN THE DRIER AND MORE STABLE NATURE OF THE AIRMASS...
COVERAGE WILL BE SCT AT BEST. PRECIP ALONG AND N OF I-4 WILL
STRUGGLE AS PERSISTENT CONVECTION OVER THE WRN PENINSULA WILL
REINFORCE THE AFOREMENTIONED DEBRIS DECKS. HOWEVER...HIGH THETA-E
AIRMASS SHOULD ALLOW A LITTLE HIGHER COVERAGE...ALBEIT BLO 50PCT.
PRECIP WILL LINGER INTO THE MID EVNG HRS AND SHOULD BE SPENT BY
MIDNIGHT...LEAVING ONLY A SLGT CHC OF DEBRIS RAINFALL OVERNIGHT.
NO TURNOVER IN AIRMASS...MIN TEMPS WILL CONTINUE IN THE M70S.
THU-FRI...
LITTLE CHANGE IN THE WX PATTERN AS THE REMNANT MOISTURE PLUME FROM
THE ERSTWHILE FRONTAL TROF WILL REMAIN OVER THE FL PENINSULA...
KEEPING RAIN CHANCES ABV AVG ESPECIALLY OVER THE INTERIOR. AS THE
ATLC RIDGE AXIS BUILDS WEST INTO THE DEEP SOUTH...IT WILL MERGE WITH
A SMALL CONTINENTAL JUST S OF THE RIO GRANDE VALLEY. THE COMBINED
RIDGE WILL BRIDGE THE OLD FRNTL BNDRY AND GENERATE AN E/SE FLOW THRU
THE H100-H70 LYR. MOISTURE AVAILABILITY WILL REMAIN HIGH ENOUGH TO
SUPPORT POPS IN THE 40-50PCT RANGE BY DAY...30-40PCT AFT SUNSET
ENDING BY MIDNIGHT.
ONE CAVEAT TO THE NIGHTTIME PDS: AS WINDS BCM MORE SERLY...NOCTURNAL
COASTAL SHRAS/TSRAS WILL BECOME PSBL AS CONVERGENT EDDIES FORM ON
THE LEEWARD SIDE OF THE NRN BAHAMAS AND ADVECT TOWARD THE SPACE AND
TREASURE COASTS. MAX TEMPS IN THE U80S/L90S WITH MIN TEMPS IN THE
L/M70S.
SAT-WED...(PREV DISC)
00Z GFS AND ECMWF HAVE AGAIN PUSHED BACK THE PROGRESSION OF DRIER
AIR INTO THE REGION. HAVE KEPT 40 POP FOR SATURDAY BUT RAISED SUNDAY
TO 40 PERCENT NOW...TAPERING OFF MORE NOTICEABLY TO 20 TO 30 PERCENT
MONDAY AND TUE. BOTH MODELS EVENTUALLY SHUNT THE DEEP TROPICAL
MOISTURE AWAY FROM THE AREA AS UPPER TROUGHING OVER THE EASTERN
CONUS DRIVES A COLD FRONT THRU CENT FL EARLY NEXT WEEK. THERE
PROBABLY WILL NOT BE TOO MUCH COOLING BEHIND THIS FRONT AS THE FLOW
WILL TURN ONSHORE QUICKLY BEHIND IT...BUT THERE LOOKS TO BE
NOTICEABLE DRYING. THIS SHOULD HELP PRODUCE MIN TEMPS OVER INTERIOR
SECTIONS IN THE UPPER 60S FOR MON AND TUE MORNINGS.
&&
.AVIATION...
THRU 04/00Z...SCT/NMRS IFR SHRAS/ISOLD LIFR TSRAS ALL SITES WITH
HIGHEST POPS N OF THE I-4 CORRIDOR...SFC WNDSHFT FROM S TO E/SE AOB
12KTS BY 03/21Z INTERIOR SITES AND COASTAL SITES N OF KMLB. BTWN
04/00Z-04/03Z...SCT MVFR SHRAS/ISOLD IFR TSRAS. AFT 04/03Z...VFR
CONDS WILL PREVAIL WITH SLGT CHC OF BRIEF MVFR SHRAS.
&&
.MARINE...
TONIGHT...SFC/BNDRY LYR WINDS WILL BACK TO THE SE AS A LARGE RIDGE
AXIS EXTENDING FROM THE NRN BAHAMAS TO THE YUCATAN PENINSULA LIFTS N
ACRS THE CENTRAL PENINSULA. WINDS WILL DIMINISH TO BLO 10KTS N OF
THE CAPE...10-15KTS S OF THE CAPE. SEAS 2-3FT NEARSHORE AND 3-4FT
OFFSHORE. SCT SHRAS/TSRAS MOVING OFFSHORE N OF THE CAPE.
THU-SAT...
THE ATLC RIDGE WILL EXPAND WESTWARD INTO THE DEEP SOUTH AND MERGE
WITH A SMALLER RIDGE CENTERED JUST S OF THE RIO GRANDE VALLEY. THE
COMBINED RIDGE WILL FORCE SFC/BNDRY LYR WINDS TO BACK TO THE EAST
WHERE WHERE THEY WILL REMAIN INTO THE WEEKEND. SEAS 2-3 FT...MAINLY
IN AN ERLY SWELL. DOMINANT PDS INCREASING TO 11-13SEC AS THE E/NE
FETCH LENGTH EXPANDS THRU THE WEEK.
SAT-MON...
LIGHT AND VARIABLE WINDS SUN AS THE LCL PGRAD WEAKENS AHEAD OF THE
NEXT FRONTAL TROF. WINDS TO SHIFT TO THE N/NW BY DAYBREAK MON AS A
NEW FRONTAL TROF PUSHES INTO THE STATE...THEN TO THE N/NE THRU THE
DAY AS HIGH PRES BEHIND THE FRONT BUILDS QUICKLY ACRS THE GULF
COAST. SEAS AOB 2FT NEARSHORE...2-3FT OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 73 87 76 86 / 40 50 40 50
MCO 74 91 73 89 / 40 50 40 50
MLB 75 87 77 87 / 30 40 30 40
VRB 76 89 77 88 / 30 40 30 40
LEE 73 90 73 88 / 40 50 40 50
SFB 74 91 75 89 / 40 50 40 50
ORL 74 91 74 90 / 40 50 40 50
FPR 76 88 77 87 / 30 40 30 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX.....LASCODY
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1027 AM EDT WED OCT 3 2012
.DISCUSSION...
FRONTALYSIS OCCURRING OVER THE ERN GOMEX THIS MORNING...DEEP
MOISTURE BAND ASSOCD WITH THE DISSIPATING FRONT WILL REMAIN
OVERHEAD. LATEST RAP ANALYSIS SHOWS THE ATLC RIDGE AXIS BEGINNING TO
NUDGE ITS WAY UP THE FL PENINSULA WITH A SLIGHTLY DRIER AND LESS
ENERGETIC AIRMASS IN TOW. MORNING RAOBS BEAR THIS OUT WITH PWATS OFF
THE KMFL/KEYW SOUNDINGS BTWN 1.5"-2.0"...INCREASING TO 2.0"-2.4" AT
KXMR/KTBW/KJAX. SFC DEWPOINTS REMAIN IN THE M70S ACRS THE CENTRAL
AND SOUTH PENINSULA...THINNER MID/UPR LVL CLOUDS OVER THE TREASURE
COAST HAVE ALLOWED TEMPS TO WARM INTO THE L/M80S WHILE THICKER
CLOUDS TO THE N ARE KEEPING TEMPS IN THE M/U70S.
WX ELEMENTS POINT TOWARD LOWER COVERAGE TODAY THAN IN RECENT DAYS.
THE NRN CWA WITH THE DEEPEST MOISTURE WILL SEE LIMITED SFC HEATING
AND DESTABILIZATION DUE TO THE THE MID/UPR LVL CLOUDS...WHILE DRIER
AND MORE STABLE AIR PUSHING INTO THE SRN CWA ALSO WILL RESULT IN
LOWER COVERAGE...ESPECIALLY AS ENHANCES SFC HEATING WILL PROMOTE THE
FORMATION OF THE EAST COAST SEA BREEZE. EARLY CONVECTION FIRING OVER
THE W FL COAST IS EMBEDDED WITHIN DEEP SRLY FLOW AND WILL LARGELY
MISS THE CWA...BUT DOES DISPLAY GREATER PRECIP POTENTIAL OVER THE
NRN CWA.
MID LVL LAPSE RATES HAVE STEEPENED SLIGHTLY...NOW RUNNING BTWN
5.0-6.0C/KM...WHILE H50 TEMPS HAVE COOLED TO BTWN -6C AND -7C. WHILE
THIS WILL PROMOTE HIGHER TSRA POTENTIAL...TOTAL LTG ACTIVITY OVER
THE PAST FEW DAYS HAS BEEN SO LOW THAT ANY INCREMENTAL INCREASES
STILL WILL RESULT IN ISOLD COVERAGE AT BEST. PREVAILING PRECIP WILL
BE LOW-TOPPED SHRAS.
H85-H70 THETA-E ANALYSIS SHOWS A MAX RUNNING PARALLEL TO THE I-4
CORRIDOR DECREASING TO A LCL MIN OVR THE FL STRAITS AND THE NRN
BAHAMAS. THIS LINES UP WELL WITH THE CURRENT POP CONFIG. TEMP/WIND
FCST LOOKS GOOD AS WELL GIVEN THE CURRENT TREND. WILL UPDATE FCST TO
REFRESH WORDING...NO SIG SUBSTANTIVE CHANGES NECESSARY.
&&
.AVIATION...
THRU 03/18Z...PREVAILING VFR...SFC WNDSHFT FM S TO E/SE AOB 12KTS
ALNG THE COAST S OF KMLB...CIGS AOA FL080 N OF KVRB-KFMY. BTWN
03/18Z-03/24Z...SCT/NMRS IFR SHRAS/ISOLD LIFR TSRAS ALL SITES WITH
HIGHEST POPS N OF THE I-4 CORRIDOR...SFC WNDSHFT FROM S TO E/SE AOB
12KTS BY 03/21Z INTERIOR SITES AND COASTAL SITES N OF KMLB. BTWN
04/00Z-04/03Z...SCT MVFR SHRAS/ISOLD IFR TSRAS. AFT
04/03Z...PREVAILING VFR WITH ISOLD MVFR SHRAS.
&&
.MARINE...
HI PRES RIDGE AXIS NUDGING NWD INTO CNTRL FL WILL GENERATE A GENTLE
TO MODERATE S/SWRLY BREEZE THRU MIDDAY. WINDS WILL BACK TO THE E/SE
BY LATE AFTN AS THE RIDGE AXIS CONTINUES TO BUILD NWD. LATEST BUOY
OBS SHOW SEAS RUNNING 2-3FT NEARSHORE AND 3-4FT OFFSHORE THIS
MORNING. LCL WIND WAVES STILL PREVAIL AT BUOY009 WITH DOMINANT WAVE
PDS ARND 4SEC. HOWEVER...OCNL OBS SHOW PDS ARND 10SEC WHILE OTHER
OFFSHORE BUOYS SHOW PDS UP TO 6-7SEC. FCST TREND LOOKS GOOD...NO SIG
CHANGES NECESSARY.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX.....LASCODY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
251 PM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS THROUGH THIS EVENING...IFR CIGS POSSIBLE THIS AFTERNOON.
* SHOWERS...POSSIBLY DRIZZLE THROUGH THIS EVENING.
* STRONG/GUSTY SOUTHWEST WINDS THURSDAY WITH A COLD FRONT LATE
THURSDAY AFTERNOON/EARLY THURSDAY EVENING. CMS
//DISCUSSION...UPDATED 18Z...
A WEAK AREA OF LOW PRESSURE CONTINUES TO SLOWLY MOVE NORTH ACROSS
NORTHEAST IL WITH QUITE VARIABLE CIGS...WHICH ARE LIFTING THROUGH
MVFR AND INTO VFR ACROSS CENTRAL IL AND FAIRLY CONFIDENT THIS
IMPROVING TREND WILL EVENTUALLY REACH THE TERMINALS THIS EVENING.
UNTIL THEN...IFR CIGS EXTEND AS CLOSE AS IKK TO GYY AND POINTS
EAST...WITH PATCHY IFR WITH HEAVIER SHOWERS. ITS STILL POSSIBLE
THAT IFR CIGS COULD AFFECT THE CHICAGO AREA TERMINALS THROUGH MID
AFTERNOON BUT APPEARS PREVAILING CIGS WILL REMAIN MVFR...OR
HIGHER AND HAVE TRENDED IN THIS DIRECTION. VISIBILITIES HAVE ALSO
SLOWLY IMPROVED TO MVFR OR BETTER...BUT IFR STILL POSSIBLE WITH
SHOWERS OR DRIZZLE.
WINDS HAVE ALREADY TURNED LIGHT SOUTHERLY ACROSS EASTERN IL AND
NORTHWEST INDIANA AND SHOULD REMAIN LIGHT SOUTH/SOUTHWEST THROUGH
THE NIGHT THEN BEGIN TO INCREASE IN SPEED AFTER SUNRISE THURSDAY.
SOME UNCERTAINTY REMAINS REGARDING HOW DEEP THE LOW LEVELS WILL
MIX ON THURSDAY. THE DEEPER THE MIXING...THE STRONGER THE WINDS
THAT WILL MIX TO THE SURFACE. FOR NOW HAVE TRENDED GUSTS INTO THE
MID/UPPER 20 KT RANGE BUT IF DEEPING MIXING DOES DEVELOP...GUSTS
INTO THE MID 30KT RANGE WILL BE POSSIBLE. A COLD FRONT WILL THEN
MOVE ACROSS THE AREA LATE IN THE AFTERNOON OR EARLY THURSDAY
EVENING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE REGARDING MVFR CIGS...LOW CONFIDENCE REGARDING
IFR CIGS.
* MEDIUM CONFIDENCE REGARDING SHOWERS AND END TIME.
* MEDIUM CONFIDENCE REGARDING WINDS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE SHOWERS AND SLIGHT CHANCE TS...OTHERWISE
VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ744-LMZ745...1 PM THURSDAY TO 10 PM
SATURDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...1 PM
THURSDAY TO 10 PM FRIDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...10 PM THURSDAY TO 4 AM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1212 PM CDT WED OCT 3 2012
.DISCUSSION...
ISSUED 1000 AM CDT WED OCT 3 2012
LATEST OBSERVATIONS AND SATELLITE IMAGERY SHOWING SURFACE LOW NOW
CENTERED JUST NORTH OF KANKAKEE. FAIRLY SHARP CLEARING LINE
PERSISTING ALONG THE ILLINOIS/IOWA BORDER...BUT IS NOT MAKING ANY
EASTWARD PROGRESS. ANOTHER CLEARING LINE CENTERED ROUGHLY ALONG
I-64 IN SOUTH CENTRAL ILLINOIS IS MOVING NORTHWARD INTO THE
SOUTHEAST EDGE OF OUR FORECAST AREA. LAYER HUMIDITY PLOTS OFF THE
RAP MODEL SHOW THIS SOUTHERN CLEARING AREA CONTINUING TO MAKE SOME
NORTHWARD PROGRESS THROUGH THE DAY...WITH SKIES BECOMING PARTLY
SUNNY SOUTH OF I-70 BY EARLY AFTERNOON. HOWEVER...THE REMAINDER OF
THE FORECAST AREA SHOULD REMAIN GENERALLY CLOUDY...WITH SOME THIN
SPOTS IN THE OVERCAST HERE AND THERE. RAP AND HRRR MODELS
CONTINUING TO HOLD ON TO SOME SCATTERED SHOWERS THROUGH THE
AFTERNOON.
HAVE SENT SOME UPDATED ZONES/GRIDS...MAINLY TO UPDATE HOURLY TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 1210 PM CDT WED OCT 3 2012
MVFR/IFR CONDITIONS RETREATING INTO NORTHEAST ILLINOIS AS LOW
PRESSURE LIFTS ACROSS THE CHICAGO AREA. STILL SOME CEILINGS AROUND
1500 FEET HANGING AROUND AS FAR SOUTH AS A KBMI-KCMI-KDNV LINE...
BUT THESE SHOULD MAINLY BE NORTH OF THE AREA BY 20Z. OTHERWISE...
VFR CEILINGS EXPECTED THROUGH THE AFTERNOON AND EARLY EVENING...
WITH SOME BREAKUP OF THE CLOUDS AS THE LOW PULLS FURTHER AWAY
FROM THE STATE. ON THURSDAY...SOUTHERLY WINDS WILL BEGIN TO PICK
UP LATE IN THE FORECAST PERIOD...WITH SOME GUSTS TO AROUND 15
KNOTS BY LATE MORNING. HOWEVER...HIGHER GUSTS ARE LIKELY DURING
THE AFTERNOON.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 240 AM CDT WED OCT 3 2012
SHORT TERM...TODAY THROUGH FRIDAY
PERSISTENT UPPER TROUGH WILL REMAIN IN PLACE FROM THE SOUTHERN
GREAT LAKES TO THE WESTERN GULF OF MEXICO TODAY...ENSURING A
CONTINUATION OF MOSTLY CLOUDY CONDITIONS. WITH WEAK SURFACE LOW
PRESSURE MEANDERING NORTHWARD ACROSS EAST-CENTRAL ILLINOIS...MAY
SEE A FEW SHOWERS SCATTERED AROUND THE AREA AS WELL. AS HAS BEEN
THE CASE FOR THE PAST COUPLE OF DAYS...THE DEEPEST MOISTURE AND
THUS BEST CHANCE FOR RAIN WILL BE CONFINED TO THE EASTERN KILX
CWA. AS A RESULT...WILL FOCUS HIGHEST POPS EAST OF I-55...TAPERING
DOWN TO JUST SLIGHT CHANCES FURTHER WEST IN THE ILLINOIS RIVER
VALLEY. TEMPERATURES WILL BE A BIT TRICKY TODAY...AS THEY WILL BE
HIGHLY DEPENDENT UPON HOW MUCH SUNSHINE OCCURS. 07Z/2AM SATELLITE
IMAGERY INDICATES THE ENTIRE AREA IS CURRENTLY BLANKETED BY CLOUD
COVER...AND WITH LOW PRESSURE SHIFTING ONLY VERY SLOWLY
NORTHWARD...THINK MOSTLY CLOUDY SKIES WILL PREVAIL THROUGHOUT THE
DAY. MAY SEE SOME BREAKS IN THE OVERCAST WEST OF THE ILLINOIS
RIVER FROM TIME TO TIME...AS WELL AS ALONG/SOUTH OF I-70 AS DRY
SLOT CONTINUES TO WRAP N/NW AROUND UPPER TROUGH. RESULTING HIGHS
WILL MAINLY BE IN THE LOWER 70S...WITH COOLEST READINGS IN THE
MIDDLE TO UPPER 60S ACROSS THE NE CWA AROUND CHAMPAIGN WHERE CLOUD
COVER WILL BE MOST PERSISTENT. UPPER TROUGH WILL FINALLY GET
EJECTED NORTHEASTWARD TONIGHT...IN RESPONSE TO NORTHERN STREAM
WAVE DIGGING INTO THE NORTHERN PLAINS/UPPER MIDWEST. WILL LINGER
LOW CHANCE POPS FOR SHOWERS INTO THE EVENING HOURS...BEFORE GOING
DRY ACROSS THE BOARD AFTER MIDNIGHT.
THURSDAY WILL BE THE WARMEST DAY OF THE FORECAST PERIOD...AS
STRONG SOUTHERLY FLOW AHEAD OF THE NEXT APPROACHING COLD FRONT
HELPS BOOST HIGH TEMPS INTO THE UPPER 70S AND LOWER 80S. COLD
FRONT IS STILL EXPECTED TO PUSH INTO ILLINOIS DURING THE
AFTERNOON...WITH MODEL CONSENSUS PLACING IT FROM JUST SOUTH OF
CHICAGO TO NEAR SAINT LOUIS BY EARLY EVENING. ALL MODELS CONTINUE
TO SUGGEST ANY PRECIP THAT DEVELOPS WILL BE PRIMARILY
POST-FRONTAL...MEANING MUCH OF CENTRAL ILLINOIS WILL REMAIN DRY
THROUGH THE ENTIRE DAY. WILL THEREFORE CONFINE POPS TO LOCATIONS
ALONG/WEST OF I-55 THURSDAY AFTERNOON...WITH DRY WEATHER
PERSISTING FURTHER EAST. RAIN CHANCES WILL INCREASE THURSDAY NIGHT
AS THE FRONT MOVES THROUGH THE REGION. GIVEN NARROW CORRIDOR OF
INSTABILITY AND INCREASING WIND-SHEAR ALONG/BEHIND THE
BOUNDARY...HAVE INCLUDED ISOLATED THUNDER THURSDAY AFTERNOON AND
EVENING.
FRONT WILL SINK INTO THE OHIO RIVER VALLEY ON FRIDAY...HOWEVER
UPPER-WAVE MOVING ALONG THE BOUNDARY WILL BRING A PERIOD OF
OVERRUNNING RAIN TO PARTS OF CENTRAL AND SOUTHEAST ILLINOIS
FRIDAY/FRIDAY NIGHT. HIGHEST RAIN CHANCES THROUGH THIS PERIOD WILL
BE ACROSS THE SOUTHERN CWA...GENERALLY ALONG/SOUTH OF I-70...WITH
RAIN CHANCES STEADILY DECREASING FURTHER NORTH. IN FACT...AREAS
ALONG AND NORTH OF A CANTON TO BLOOMINGTON-NORMAL LINE MAY REMAIN
COMPLETELY DRY ON FRIDAY. NORTHERLY WINDS BEHIND THE FRONT WILL
BRING SHARPLY COOLER CONDITIONS INTO THE REGION FOR THE END OF THE
WEEK...WITH HIGH TEMPS ON FRIDAY REMAINING IN THE 50S.
LONG TERM...SATURDAY THROUGH TUESDAY
ONCE UPPER WAVE TRACKS OFF TO THE EAST...FRONT WILL GET PUSHED
FURTHER SOUTH OVER THE WEEKEND...RESULTING IN COOL/DRY CONDITIONS
FOR BOTH SATURDAY AND SUNDAY. AS HIGH PRESSURE BUILDS INTO THE
REGION...CLEAR SKIES AND LIGHT WINDS WILL ALLOW OVERNIGHT LOW
TEMPS TO DROP INTO THE LOWER TO MIDDLE 30S BOTH DAYS. AFTER
THAT...SOUTHERLY RETURN FLOW ON THE BACK SIDE OF THE DEPARTING
HIGH WILL SIGNAL A WARMING TREND EARLY NEXT WEEK...WITH HIGH TEMPS
CLIMBING BACK INTO THE MIDDLE 60S BY TUESDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1109 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* VARIABLE WINDS BECOMING SOUTHERLY LATER THIS AFTERNOON.
* MVFR CIGS INTO TONIGHT...WITH IFR CIGS POSSIBLE THROUGH MID
AFTERNOON.
* SHOWERS/AREAS OF DRIZZLE TODAY...POSSIBLY REDUCING VIS TO IFR
THROUGH MID AFTERNOON. CMS
//DISCUSSION...UPDATED 12Z...
CONDITIONS HAVE QUICKLY DETERIORATED THIS MORNING WITH THE ARRIVAL
OF THIS WEAK LOW PRESSURE AND EXPANSIVE AREA OF LOW LEVEL
MOISTURE. IFR CEILINGS BEING REPORTED ACROSS ORD/MDW/GYY
AREAS...WITH THESE LOW CLOUDS TO AFFECT DPA IN THE NEXT HOUR AND
RFD TO REMAIN VFR THROUGH THE FORECAST PERIOD. HAVE CONTINUED
PESSIMISTIC TRENDS WITH LOW CEILINGS TODAY...KEEPING IFR
CONDITIONS OVERHEAD FOR MUCH OF THE DAY. SOME UNCERTAINTY AS TO
THE OVERALL TREND WITH THE CEILINGS TODAY REMAINS...AS IT IS
CONCEIVABLE THAT THESE IFR CONDITIONS COULD LINGER EVEN INTO THE
EARLY EVENING BEFORE LOW/MID LEVEL FLOW INCREASES AND REALLY HELPS
STEER THIS MOISTURE OUT OF THE TERMINAL AREAS. ALTHOUGH AT THIS
TIME...HAVE NOT GONE THAT FAR WITH THE FORECAST AND BRING CEILINGS
UP TO MVFR CONDITIONS LATER THIS AFTERNOON AND THEN EVENTUALLY
SCATTERING THEM OUT TONIGHT. FOG/DRIZZLE WILL ALSO CONTINUE FOR A
GOOD PORTION OF TODAY...WITH VIS RESTRICTIONS EXPECTED INTO THIS
AFTERNOON. WITH THE WEAKENING LOW CENTER MOVING
OVERHEAD...VARIABLE WINDS WILL BE OBSERVED FOR MOST OF TODAY
BEFORE SURFACE PATTERN ALLOWS FOR WINDS TO BECOME MORE ORGANIZED
OUT OF THE SOUTH. VFR CONDITIONS EXPECTED THURSDAY MORNING BUT
WITH SOUTH/SOUTHWEST WINDS/GUSTS REALLY INCREASING BY MID DAY.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE REGARDING MVFR CIGS...LOW CONFIDENCE REGARDING
IFR CIGS.
* MEDIUM CONFIDENCE REGARDING SHOWERS AND VIS TRENDS. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE SHOWERS AND SLIGHT CHANCE TS...OTHERWISE
VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1000 AM CDT WED OCT 3 2012
.DISCUSSION...
ISSUED 1000 AM CDT WED OCT 3 2012
LATEST OBSERVATIONS AND SATELLITE IMAGERY SHOWING SURFACE LOW NOW
CENTERED JUST NORTH OF KANKAKEE. FAIRLY SHARP CLEARING LINE
PERSISTING ALONG THE ILLINOIS/IOWA BORDER...BUT IS NOT MAKING ANY
EASTWARD PROGRESS. ANOTHER CLEARING LINE CENTERED ROUGHLY ALONG
I-64 IN SOUTH CENTRAL ILLINOIS IS MOVING NORTHWARD INTO THE
SOUTHEAST EDGE OF OUR FORECAST AREA. LAYER HUMIDITY PLOTS OFF THE
RAP MODEL SHOW THIS SOUTHERN CLEARING AREA CONTINUING TO MAKE SOME
NORTHWARD PROGRESS THROUGH THE DAY...WITH SKIES BECOMING PARTLY
SUNNY SOUTH OF I-70 BY EARLY AFTERNOON. HOWEVER...THE REMAINDER OF
THE FORECAST AREA SHOULD REMAIN GENERALLY CLOUDY...WITH SOME THIN
SPOTS IN THE OVERCAST HERE AND THERE. RAP AND HRRR MODELS
CONTINUING TO HOLD ON TO SOME SCATTERED SHOWERS THROUGH THE
AFTERNOON.
HAVE SENT SOME UPDATED ZONES/GRIDS...MAINLY TO UPDATE HOURLY TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 640 AM CDT WED OCT 3 2012
CEILINGS BELOW 1K FT AND VSBYS BELOW 3 MILES OVER EASTERN IL TAF
SITES OF BMI...DEC AND CMI (WHERE DENSE FOG AT CMI WITH VSBYS AS
LOW AS 1/4-1/2 MILE) WILL GRADUALLY LIFT TO MVFR LATE THIS MORNING.
WESTERN TAF SITES OF PIA AND SPI WILL SEE MVFR CEILINGS 2-3K FT
INTO MID MORNING AND LIFT TO 6-8K FT BY LATE MORNING. SPOTTY LIGHT
RAIN SHOWERS AND PATCHY DRIZZLE WILL OCCUR TODAY ACROSS CENTRAL IL
DUE TO NEARBY STRONG UPPER LEVEL TROF OVER IL. WEAK LOW PRESSURE
1013 MB NEAR PONTIAC WILL CONTINUE SLOW NORTHWARD DRIFT INTO NE IL
TODAY WHILE 570 DM 500 MB LOW NEAR ST LOUIS AND 571 DM 500 MB LOW
OVER NORTH LA TO SHIFT SLOWLY EAST TO THE IL/IN BORDER BY 06Z/1 AM
TONIGHT AND INTO EASTERN INDIANA AND CENTRAL KY BY 12Z/7 AM THU.
EXPECT CLOUDS TO SCATTER OUT FROM WEST TO EAST DURING THIS EVENING
AS UPPER LEVEL TROF AXIS SHIFTS EASTWARD. SSW WINDS 5-10 KTS TODAY
WILL BE SOUTH 4-8 KTS TONIGHT AND INCREASE DURING THU MORNING AS A
STRONG COLD FRONT FROM NW MN INTO CENTRAL SD MOVES SE TO THE IA/IL
BORDER BY 18Z/1 PM THU.
KH
&&
.PREV DISCUSSION...
ISSUED 240 AM CDT WED OCT 3 2012
SHORT TERM...TODAY THROUGH FRIDAY
PERSISTENT UPPER TROUGH WILL REMAIN IN PLACE FROM THE SOUTHERN
GREAT LAKES TO THE WESTERN GULF OF MEXICO TODAY...ENSURING A
CONTINUATION OF MOSTLY CLOUDY CONDITIONS. WITH WEAK SURFACE LOW
PRESSURE MEANDERING NORTHWARD ACROSS EAST-CENTRAL ILLINOIS...MAY
SEE A FEW SHOWERS SCATTERED AROUND THE AREA AS WELL. AS HAS BEEN
THE CASE FOR THE PAST COUPLE OF DAYS...THE DEEPEST MOISTURE AND
THUS BEST CHANCE FOR RAIN WILL BE CONFINED TO THE EASTERN KILX
CWA. AS A RESULT...WILL FOCUS HIGHEST POPS EAST OF I-55...TAPERING
DOWN TO JUST SLIGHT CHANCES FURTHER WEST IN THE ILLINOIS RIVER
VALLEY. TEMPERATURES WILL BE A BIT TRICKY TODAY...AS THEY WILL BE
HIGHLY DEPENDENT UPON HOW MUCH SUNSHINE OCCURS. 07Z/2AM SATELLITE
IMAGERY INDICATES THE ENTIRE AREA IS CURRENTLY BLANKETED BY CLOUD
COVER...AND WITH LOW PRESSURE SHIFTING ONLY VERY SLOWLY
NORTHWARD...THINK MOSTLY CLOUDY SKIES WILL PREVAIL THROUGHOUT THE
DAY. MAY SEE SOME BREAKS IN THE OVERCAST WEST OF THE ILLINOIS
RIVER FROM TIME TO TIME...AS WELL AS ALONG/SOUTH OF I-70 AS DRY
SLOT CONTINUES TO WRAP N/NW AROUND UPPER TROUGH. RESULTING HIGHS
WILL MAINLY BE IN THE LOWER 70S...WITH COOLEST READINGS IN THE
MIDDLE TO UPPER 60S ACROSS THE NE CWA AROUND CHAMPAIGN WHERE CLOUD
COVER WILL BE MOST PERSISTENT. UPPER TROUGH WILL FINALLY GET
EJECTED NORTHEASTWARD TONIGHT...IN RESPONSE TO NORTHERN STREAM
WAVE DIGGING INTO THE NORTHERN PLAINS/UPPER MIDWEST. WILL LINGER
LOW CHANCE POPS FOR SHOWERS INTO THE EVENING HOURS...BEFORE GOING
DRY ACROSS THE BOARD AFTER MIDNIGHT.
THURSDAY WILL BE THE WARMEST DAY OF THE FORECAST PERIOD...AS
STRONG SOUTHERLY FLOW AHEAD OF THE NEXT APPROACHING COLD FRONT
HELPS BOOST HIGH TEMPS INTO THE UPPER 70S AND LOWER 80S. COLD
FRONT IS STILL EXPECTED TO PUSH INTO ILLINOIS DURING THE
AFTERNOON...WITH MODEL CONSENSUS PLACING IT FROM JUST SOUTH OF
CHICAGO TO NEAR SAINT LOUIS BY EARLY EVENING. ALL MODELS CONTINUE
TO SUGGEST ANY PRECIP THAT DEVELOPS WILL BE PRIMARILY
POST-FRONTAL...MEANING MUCH OF CENTRAL ILLINOIS WILL REMAIN DRY
THROUGH THE ENTIRE DAY. WILL THEREFORE CONFINE POPS TO LOCATIONS
ALONG/WEST OF I-55 THURSDAY AFTERNOON...WITH DRY WEATHER
PERSISTING FURTHER EAST. RAIN CHANCES WILL INCREASE THURSDAY NIGHT
AS THE FRONT MOVES THROUGH THE REGION. GIVEN NARROW CORRIDOR OF
INSTABILITY AND INCREASING WIND-SHEAR ALONG/BEHIND THE
BOUNDARY...HAVE INCLUDED ISOLATED THUNDER THURSDAY AFTERNOON AND
EVENING.
FRONT WILL SINK INTO THE OHIO RIVER VALLEY ON FRIDAY...HOWEVER
UPPER-WAVE MOVING ALONG THE BOUNDARY WILL BRING A PERIOD OF
OVERRUNNING RAIN TO PARTS OF CENTRAL AND SOUTHEAST ILLINOIS
FRIDAY/FRIDAY NIGHT. HIGHEST RAIN CHANCES THROUGH THIS PERIOD WILL
BE ACROSS THE SOUTHERN CWA...GENERALLY ALONG/SOUTH OF I-70...WITH
RAIN CHANCES STEADILY DECREASING FURTHER NORTH. IN FACT...AREAS
ALONG AND NORTH OF A CANTON TO BLOOMINGTON-NORMAL LINE MAY REMAIN
COMPLETELY DRY ON FRIDAY. NORTHERLY WINDS BEHIND THE FRONT WILL
BRING SHARPLY COOLER CONDITIONS INTO THE REGION FOR THE END OF THE
WEEK...WITH HIGH TEMPS ON FRIDAY REMAINING IN THE 50S.
LONG TERM...SATURDAY THROUGH TUESDAY
ONCE UPPER WAVE TRACKS OFF TO THE EAST...FRONT WILL GET PUSHED
FURTHER SOUTH OVER THE WEEKEND...RESULTING IN COOL/DRY CONDITIONS
FOR BOTH SATURDAY AND SUNDAY. AS HIGH PRESSURE BUILDS INTO THE
REGION...CLEAR SKIES AND LIGHT WINDS WILL ALLOW OVERNIGHT LOW
TEMPS TO DROP INTO THE LOWER TO MIDDLE 30S BOTH DAYS. AFTER
THAT...SOUTHERLY RETURN FLOW ON THE BACK SIDE OF THE DEPARTING
HIGH WILL SIGNAL A WARMING TREND EARLY NEXT WEEK...WITH HIGH TEMPS
CLIMBING BACK INTO THE MIDDLE 60S BY TUESDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
901 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* VARIABLE WINDS BECOMING SOUTHERLY LATER THIS AFTERNOON.
* IFR CEILINGS FOR A GOOD PORTION OF TODAY...BEFORE SLOWLY RISING
TO MVFR LATER THIS AFTERNOON.
* SHOWERS/AREAS OF DRIZZLE TODAY...POSSIBLY REDUCING VIS TO IFR
THIS MORNING. CMS
//DISCUSSION...UPDATED 12Z...
CONDITIONS HAVE QUICKLY DETERIORATED THIS MORNING WITH THE ARRIVAL
OF THIS WEAK LOW PRESSURE AND EXPANSIVE AREA OF LOW LEVEL
MOISTURE. IFR CEILINGS BEING REPORTED ACROSS ORD/MDW/GYY
AREAS...WITH THESE LOW CLOUDS TO AFFECT DPA IN THE NEXT HOUR AND
RFD TO REMAIN VFR THROUGH THE FORECAST PERIOD. HAVE CONTINUED
PESSIMISTIC TRENDS WITH LOW CEILINGS TODAY...KEEPING IFR
CONDITIONS OVERHEAD FOR MUCH OF THE DAY. SOME UNCERTAINTY AS TO
THE OVERALL TREND WITH THE CEILINGS TODAY REMAINS...AS IT IS
CONCEIVABLE THAT THESE IFR CONDITIONS COULD LINGER EVEN INTO THE
EARLY EVENING BEFORE LOW/MID LEVEL FLOW INCREASES AND REALLY HELPS
STEER THIS MOISTURE OUT OF THE TERMINAL AREAS. ALTHOUGH AT THIS
TIME...HAVE NOT GONE THAT FAR WITH THE FORECAST AND BRING CEILINGS
UP TO MVFR CONDITIONS LATER THIS AFTERNOON AND THEN EVENTUALLY
SCATTERING THEM OUT TONIGHT. FOG/DRIZZLE WILL ALSO CONTINUE FOR A
GOOD PORTION OF TODAY...WITH VIS RESTRICTIONS EXPECTED INTO THIS
AFTERNOON. WITH THE WEAKENING LOW CENTER MOVING
OVERHEAD...VARIABLE WINDS WILL BE OBSERVED FOR MOST OF TODAY
BEFORE SURFACE PATTERN ALLOWS FOR WINDS TO BECOME MORE ORGANIZED
OUT OF THE SOUTH. VFR CONDITIONS EXPECTED THURSDAY MORNING BUT
WITH SOUTH/SOUTHWEST WINDS/GUSTS REALLY INCREASING BY MID DAY.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH CEILING TRENDS TODAY...WITH LOW
MEDIUM CONFIDENCE AS TO THE EXACT LENGTH OF PERIOD WHICH THE IFR
CEILINGS WILL REMAIN OVER THE TERMINALS.
* MEDIUM HIGH CONFIDENCE WITH SHOWERS/DRIZZLE AND VIS TRENDS. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE SHOWERS AND SLIGHT CHANCE TS...OTHERWISE
VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
700 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* VARIABLE WINDS BECOMING SOUTHERLY LATER THIS AFTERNOON.
* IFR CEILINGS FOR A GOOD PORTION OF TODAY...BEFORE SLOWLY RISING
TO MVFR LATER THIS AFTERNOON.
* FOG/DRIZZLE WITH VIS OF 3-5SM EXPECTED TODAY...AND BRIEF PERIODS
OF VIS AROUND 2SM THIS MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
CONDITIONS HAVE QUICKLY DETERIORATED THIS MORNING WITH THE ARRIVAL
OF THIS WEAK LOW PRESSURE AND EXPANSIVE AREA OF LOW LEVEL
MOISTURE. IFR CEILINGS BEING REPORTED ACROSS ORD/MDW/GYY
AREAS...WITH THESE LOW CLOUDS TO AFFECT DPA IN THE NEXT HOUR AND
RFD TO REMAIN VFR THROUGH THE FORECAST PERIOD. HAVE CONTINUED
PESSIMISTIC TRENDS WITH LOW CEILINGS TODAY...KEEPING IFR
CONDITIONS OVERHEAD FOR MUCH OF THE DAY. SOME UNCERTAINTY AS TO
THE OVERALL TREND WITH THE CEILINGS TODAY REMAINS...AS IT IS
CONCEIVABLE THAT THESE IFR CONDITIONS COULD LINGER EVEN INTO THE
EARLY EVENING BEFORE LOW/MID LEVEL FLOW INCREASES AND REALLY HELPS
STEER THIS MOISTURE OUT OF THE TERMINAL AREAS. ALTHOUGH AT THIS
TIME...HAVE NOT GONE THAT FAR WITH THE FORECAST AND BRING CEILINGS
UP TO MVFR CONDITIONS LATER THIS AFTERNOON AND THEN EVENTUALLY
SCATTERING THEM OUT TONIGHT. FOG/DRIZZLE WILL ALSO CONTINUE FOR A
GOOD PORTION OF TODAY...WITH VIS RESTRICTIONS EXPECTED INTO THIS
AFTERNOON. WITH THE WEAKENING LOW CENTER MOVING
OVERHEAD...VARIABLE WINDS WILL BE OBSERVED FOR MOST OF TODAY
BEFORE SURFACE PATTERN ALLOWS FOR WINDS TO BECOME MORE ORGANIZED
OUT OF THE SOUTH. VFR CONDITIONS EXPECTED THURSDAY MORNING BUT
WITH SOUTH/SOUTHWEST WINDS/GUSTS REALLY INCREASING BY MID DAY.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH CEILING TRENDS TODAY...WITH LOW
MEDIUM CONFIDENCE AS TO THE EXACT LENGTH OF PERIOD WHICH THE IFR
CEILINGS WILL REMAIN OVER THE TERMINALS.
* MEDIUM HIGH CONFIDENCE WITH FOG/DRIZZLE AND VIS TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE SHOWERS AND SLIGHT CHANCE TS...OTHERWISE
VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
546 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT NORTHEAST WINDS BECOMING VARIABLE THROUGH MUCH OF THE
MORNING.
* MVFR CEILINGS LOWERING TO IFR CEILINGS BY 12/13Z THIS
MORNING...AND LINGERING THROUGH THE REMAINDER OF THE MORNING.
* LIGHT SHOWERS/FOG MOVING ACROSS THE TERMINALS THIS MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 09Z...
HAVE MADE SIGNIFICANT CHANGES TO THE TAF WITH THIS UPDATE...GOING
MORE PESSIMISTIC WITH THE CEILINGS THIS MORNING. GOOD SWATH OF
MVFR/IFR CEILINGS CURRENTLY RESIDE JUST SOUTH OF THE TERMINALS AND
AS THIS WEAK LOW CONTINUES NORTH...DONT SEE ANY REASON WHY THESE
LOW CEILINGS WONT MOVE OVERHEAD. SO HAVE STARTED THE TAFS WITH
MVFR CEILINGS BUT HAVE CONDITIONS QUICKLY DETERIORATING TO IFR
CEILINGS AROUND THE 12/13Z TIME FRAME. EXPECT THESE LOW CLOUDS TO
LINGER THROUGH THE REMAINDER OF THE MORNING...BEFORE SLOWLY
LIFTING THIS AFTERNOON.
LIGHT NORTHEAST WINDS WILL PERSIST BEFORE BECOMING MORE VARIABLE
AS THE WEAKENING LOW CENTER MOVES OVERHEAD. THEN A RETURN TO LIGHT
SOUTHERLY WINDS WILL BE OBSERVED LATER THIS AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE WITH CEILING TRENDS AS WELL AS IFR TIMING
THROUGH THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWER/FOG TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE SHOWERS...SLIGHT CHANCE TS.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TRS
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
420 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT NORTHEAST WINDS BECOMING VARIABLE THROUGH MUCH OF THE
MORNING.
* MVFR CEILINGS LOWERING TO IFR CEILINGS BY 12/13Z THIS
MORNING...AND LINGERING THROUGH THE REMAINDER OF THE MORNING.
* LIGHT SHOWERS/FOG MOVING ACROSS THE TERMINALS THIS MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 09Z...
HAVE MADE SIGNIFICANT CHANGES TO THE TAF WITH THIS UPDATE...GOING
MORE PESSIMISTIC WITH THE CEILINGS THIS MORNING. GOOD SWATH OF
MVFR/IFR CEILINGS CURRENTLY RESIDE JUST SOUTH OF THE TERMINALS AND
AS THIS WEAK LOW CONTINUES NORTH...DONT SEE ANY REASON WHY THESE
LOW CEILINGS WONT MOVE OVERHEAD. SO HAVE STARTED THE TAFS WITH
MVFR CEILINGS BUT HAVE CONDITIONS QUICKLY DETERIORATING TO IFR
CEILINGS AROUND THE 12/13Z TIME FRAME. EXPECT THESE LOW CLOUDS TO
LINGER THROUGH THE REMAINDER OF THE MORNING...BEFORE SLOWLY
LIFTING THIS AFTERNOON.
LIGHT NORTHEAST WINDS WILL PERSIST BEFORE BECOMING MORE VARIABLE
AS THE WEAKENING LOW CENTER MOVES OVERHEAD. THEN A RETURN TO LIGHT
SOUTHERLY WINDS WILL BE OBSERVED LATER THIS AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE WITH CEILING TRENDS AS WELL AS IFR TIMING
THROUGH THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWER/FOG TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE SHOWERS...SLIGHT CHANCE TS.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TRS
&&
.MARINE...
215 PM CDT
A WEAK RIDGE LIES JUST TO THE WEST OF LAKE MICHIGAN WHILE AN AREA
OF LOW PRESSURE IS LIFTING NORTH ACROSS THE MID TO UPPER OHIO
RIVER VALLEY THIS AFTERNOON. A MODEST GRADIENT IS IN PLACE OVER
FAR SOUTHERN LAKE MICHIGAN ALLOWING NORTHEASTERLY WINDS TO FRESHEN
UP SOME THIS AFTERNOON...BUT THE GRADIENT WILL WEAKEN THROUGH
THE EVENING AND OVERNIGHT AS THE LOW SLOWLY FILLS. TO OUR
WEST...LOW PRESSURE WILL BEGIN TO TAKE SHAPE OVER THE CENTRAL
PLAINS WEDNESDAY...AND DEEPEN AS IT LIFTS NORTHEAST INTO THE UPPER
MIDWEST WEDNESDAY NIGHT INTO THURSDAY. THERE IS CONSIDERABLE
SPREAD IN THE DIFFERENT MODELS SOLUTIONS REGARDING THE POSITION OF
THE LOW BY THURSDAY MORNING LEADING TO A LOW DEGREE OF CONFIDENCE
IN DETAILS OF THE FORECAST. IN GENERAL THOUGH...EXPECT
SOUTHWESTERLY WINDS TO INCREASE THROUGH THE DAY THURSDAY. WINDS
MAY BE SOMEWHAT TEMPERED BY STABLE CONDITIONS CREATED BY THE WARM
ADVECTION...BUT STILL THINK THAT WINDS MAY INCREASE TO AROUND 30
KT. A COLD FRONT WILL SWEEP ACROSS THE LAKE AS EARLY AS THURSDAY
AFTERNOON...BUT MORE LIKELY THURSDAY NIGHT AS THE LOW TRACKS OVER
THE NORTHERN GREAT LAKES REGION. COLD ADVECTION WILL ALLOW FOR
WINDS TO MIX TO THE LAKE SURFACE AND A STRONG
GRADIENT...PARTICULARLY OVER THE NORTHERN PORTIONS OF THE
LAKE...WILL ALLOW WINDS TO INCREASE TO GALE FORCE. A GALE WATCH
MAY BE ISSUED WHEN MODEL GUIDANCE COMES INTO BETTER AGREEMENT.
HIGH PRESSURE WILL GRADUALLY BUILD WEST OF THE GREAT LAKES THIS
WEEKEND...SINKING SOUTHEAST ACROSS THE MID MISSISSIPPI RIVER
VALLEY LATE THIS WEEKEND...AND KEEPING LAKE MICHIGAN IN AT LEAST A
MODERATE GRADIENT AND PROPPING UP WINDS. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
259 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 25 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIGHT NORTHEAST WINDS BECOMING VARIABLE THROUGH MUCH OF THE
MORNING.
* VFR CEILINGS SLOWLY LOWERING TO MVFR CEILINGS BY 10/11Z THIS
MORNING...AND LINGERING INTO THE AFTERNOON.
* LIGHT SHOWERS/FOG MOVING ACROSS THE TERMINALS LATER THIS
MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
WITH A SLOWLY MOVING AREA OF LOW PRESSURE JUST TO THE SOUTH OF THE
TERMINALS THIS MORNING...LOWER CLOUD COVER FINALLY WORKING ITS WAY
NEAR THE TERMINALS. DESPITE THIS LOW PRESSURE WEAKENING AS IT
MOVES OVERHEAD THIS MORNING...VFR CEILINGS SHOULD LOWER TO HIGH
END MVFR CEILINGS. HAVE CEILINGS LOWERING TO 2500FT BY THE 10/11Z
TIME FRAME THIS MORNING WITH SOME SLIGHT LOWERING TO 2000FT BY MID
MORNING. ALTHOUGH LOWER CEILINGS ARE CURRENTLY BEING OBSERVED
CLOSER TO THE LOW CENTER...STILL AM NOT QUITE CONFIDENT HOW LOW
THE CEILINGS COULD GO ONCE THIS LOW PRESSURE REACHES THE
TERMINALS. AT THIS POINT...A LOWER END POSSIBILITY WOULD BE AROUND
THE 1500FT RANGE BUT WILL NEED TO CONTINUE TO MONITOR TRENDS AND
ADJUST AS NEEDED. LIGHT SHOWERS SHOULD FINALLY MOVE ACROSS THE
TERMINALS BY MID TO LATE MORNING AND CONTINUING INTO THE EARLY
AFTERNOON. ALTHOUGH...AM NOT OVERLY CONCERNED WITH ANY REAL VIS
RESTRICTION WITH THESE SHOWERS...BUT RATHER WILL WATCH FOG TRENDS
AS THIS COULD PLAY A ROLE WITH SOME POSSIBLE LOWER VIS
RESTRICTIONS.
LIGHT NORTHEAST WINDS WILL PERSIST OVER THE NEXT SEVERAL HOURS
BEFORE BECOMING MORE VARIABLE AS THIS WEAKENING LOW CENTER MOVES
OVERHEAD. THEN A RETURN TO LIGHT SOUTHERLY WINDS WILL BE OBSERVED
LATER THIS AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE WITH CEILING TRENDS AS WELL AS MVFR TIMING
THROUGH THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWER/FOG TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE SHOWERS...SLIGHT CHANCE TS.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TRS
&&
.MARINE...
215 PM CDT
A WEAK RIDGE LIES JUST TO THE WEST OF LAKE MICHIGAN WHILE AN AREA
OF LOW PRESSURE IS LIFTING NORTH ACROSS THE MID TO UPPER OHIO
RIVER VALLEY THIS AFTERNOON. A MODEST GRADIENT IS IN PLACE OVER
FAR SOUTHERN LAKE MICHIGAN ALLOWING NORTHEASTERLY WINDS TO FRESHEN
UP SOME THIS AFTERNOON...BUT THE GRADIENT WILL WEAKEN THROUGH
THE EVENING AND OVERNIGHT AS THE LOW SLOWLY FILLS. TO OUR
WEST...LOW PRESSURE WILL BEGIN TO TAKE SHAPE OVER THE CENTRAL
PLAINS WEDNESDAY...AND DEEPEN AS IT LIFTS NORTHEAST INTO THE UPPER
MIDWEST WEDNESDAY NIGHT INTO THURSDAY. THERE IS CONSIDERABLE
SPREAD IN THE DIFFERENT MODELS SOLUTIONS REGARDING THE POSITION OF
THE LOW BY THURSDAY MORNING LEADING TO A LOW DEGREE OF CONFIDENCE
IN DETAILS OF THE FORECAST. IN GENERAL THOUGH...EXPECT
SOUTHWESTERLY WINDS TO INCREASE THROUGH THE DAY THURSDAY. WINDS
MAY BE SOMEWHAT TEMPERED BY STABLE CONDITIONS CREATED BY THE WARM
ADVECTION...BUT STILL THINK THAT WINDS MAY INCREASE TO AROUND 30
KT. A COLD FRONT WILL SWEEP ACROSS THE LAKE AS EARLY AS THURSDAY
AFTERNOON...BUT MORE LIKELY THURSDAY NIGHT AS THE LOW TRACKS OVER
THE NORTHERN GREAT LAKES REGION. COLD ADVECTION WILL ALLOW FOR
WINDS TO MIX TO THE LAKE SURFACE AND A STRONG
GRADIENT...PARTICULARLY OVER THE NORTHERN PORTIONS OF THE
LAKE...WILL ALLOW WINDS TO INCREASE TO GALE FORCE. A GALE WATCH
MAY BE ISSUED WHEN MODEL GUIDANCE COMES INTO BETTER AGREEMENT.
HIGH PRESSURE WILL GRADUALLY BUILD WEST OF THE GREAT LAKES THIS
WEEKEND...SINKING SOUTHEAST ACROSS THE MID MISSISSIPPI RIVER
VALLEY LATE THIS WEEKEND...AND KEEPING LAKE MICHIGAN IN AT LEAST A
MODERATE GRADIENT AND PROPPING UP WINDS. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1223 PM MDT WED OCT 3 2012
.UPDATE...
ISSUED AT 547 AM MDT WED OCT 3 2012
ISSUED RED FLAG WARNING FOR SOUTHWEST NEBRASKA COUNTIES AND YUMA
COUNTY COLORADO. SEE FIRE SECTION FOR DETAILS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 247 AM MDT WED OCT 3 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS A SHORTWAVE RIDGE
EXTENDING NORTH ACROSS NORTHWEST KANSAS AND CENTRAL NEBRASKA.
UPSTREAM A TROUGH IS DIGGING SOUTH INTO NORTHERN IDAHO AND
WESTERN MONTANA. AT THE SURFACE...LOW PRESSURE REMAINS IN PLACE
ACROSS THE HIGH PLAINS WITH A SURFACE COLD FRONT DEEPENING ACROSS
SOUTH DAKOTA...AND A SURFACE TROUGH AXIS EXTENDING JUST WEST OF
THE COLORADO/KANSAS STATE LINE.
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS IN THE UPPER
80S/LOW 90S AS SOUTHERLY FLOW ADVECTS MUCH WARMER AIR INTO THE
REGION AHEAD OF THE APPROACHING COLD FRONT.
TONIGHT...THE COLD FRONT OVER SOUTH DAKOTA IS EXPECTED TO PUSH
SOUTH ACROSS THE CWA BY MIDNIGHT AS THE SHORTWAVE TROUGH DIGS
SOUTH AND EAST ACROSS THE NORTHERN PLAINS. WINDY CONDITIONS ARE
EXPECTED THIS EVENING AND OVERNIGHT BEHIND THE FRONT...AND WILL
APPROACH WIND ADVISORY CRITERIA WITH GUSTS POSSIBLY IN THE 40-45
MPH RANGE. I WAS NOT CONFIDENT ENOUGH TO GO THAT HIGH YET WITH
SOME DIFFERENCES BETWEEN GUIDANCE ON MAGNITUDE OF THE WINDS...AND
THE WINDOW FOR THESE CONDITIONS SEEMS TO BE FAIRLY BRIEF. A FEW
SHOWERS WILL BE POSSIBLE MAINLY IN THE 03Z- 09Z TIME FRAME WHEN
BEST LARGE SCALE ASCENT IS ADVERTISED. DUE TO THE SPEED AND
NORTHERN TRACK OF THE TROUGH AND MINIMAL MOISTURE...CONFIDENCE IS
LOW IN MEASURABLE PRECIP. I KEPT POPS LIMITED TO SLIGHT CHANCE
CATEGORY FOR NOW...AND CONSIDERED ONLY INCLUDING MENTION OF
SPRINKLES.
THURSDAY...COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN THE
50S/60S AND OVERNIGHT LOWS THURSDAY NIGHT IN THE MID 30S. WIND AND
INCREASING CLOUDS WILL LIMIT RADIATION COOLING THURSDAY
NIGHT...OTHERWISE I WOULD BE CONCERNED WITH HARD FREEZE CONDITIONS
BASED ON ADVERTISED H85 TEMPS IN THE 0C-3C RANGE. FOR NOW IT
LOOKS LIKE WE WILL BE IN THE UPPER LIMIT OF LOCAL FROST ADVISORY
CRITERIA.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 247 AM MDT WED OCT 3 2012
THE ANTICIPATED SIGNIFICANT WEATHER CHANGE STILL LOOKS ON TRACK
FOR THE WEEKEND AS A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH IS
FORECAST TO SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND
SATURDAY. DYNAMICS FROM A 105 KT JET AT 250 MB WILL ENHANCE LIFT
FRIDAY NIGHT INTO SATURDAY MORNING WHEN BOTH THE GFS/EC FORECAST A
SATURATED LOWER ATMOSPHERE. GIVEN 850 MB TEMPS OF ZERO TO -2C AND
SATURATED AIR ABOVE -10C...ANTICIPATE LIGHT SNOW ACROSS THE
COLORADO COUNTIES SATURDAY MORNING AND A RAIN-SNOW MIX POSSIBLE
FURTHER EAST. GUIDANCE SUGGESTS LOW AND MID LEVELS WILL RAPIDLY
DRY OUT SATURDAY AFTERNOON AS THE JET AXIS AND UPPER TROUGH SLIDE
SOUTHEAST OF THE FORECAST AREA...ENDING PRECIP CHANCES.
850 MB TEMPERATURES OF 0 TO -2C ARE FORECAST SATURDAY MORNING...
WARMING ONLY A FEW DEGREES BY LATE AFTERNOON. HIGHS WILL HOLD IN THE
40S WHICH IS 25-30 DEGREES BELOW NORMAL. THE NORTHWEST THIRD OF THE
AREA SHOULD SEE MIN TEMPS SATURDAY IN THE 30-32 F RANGE AND BY
SUNDAY MORNING WITH LESS CLOUDS...MIN TEMPERATURES COULD DROP AS LOW
AS THE UPPER 20S...MAINLY IN THE NORTHWEST...WITH LOW 30S ELSEWHERE.
AFTERNOON HIGH TEMPERATURES WILL MODERATE SUNDAY AND MONDAY WITH
TEMPS STILL BELOW NORMAL BUT RETURNING TO THE 50S SUNDAY AND 60S
MONDAY. BOTH GFS/EC HINT AT ANOTHER COLD FRONT ARRIVING TUESDAY
WITH THE AIR MASS MOVING THROUGH RATHER QUICKLY...AND THE
POTENTIAL FOR PRECIPITATION AROUND MID WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1155 AM MDT WED OCT 3 2012
SOUTHWESTERLY WINDS WILL GRADUALLY PICK UP THROUGH THE AFTERNOON
AS A STRONG COLD FRONT DROPS SOUTH AND MOVES ACROSS THE REGION. EXPECTED
ARRIVAL TIME OF COLD FRONT IS BETWEEN 00-02Z THIS EVENING...WITH
NORTHERLY WINDS GUSTING 30-35 KTS BEHIND THE FRONT. STRONGEST
WINDS APPEAR TO BE RIGHT AFTER THE FRONT PASSES AND WILL GRADUALLY
WEAKEN THROUGH THE END OF THE PERIOD. THE OTHER CONCERN IS FOCUSED
ON PRECIPITATION CHANCES BEHIND THE FRONT. GIVEN CURRENT UPSTREAM
OBSERVATIONS AND MODEL ANALYSIS...LIGHT RAIN IS EXPECTED TO DEVELOP FOR A
FEW HOURS AND MAY REDUCE VISIBILITY BRIEFLY. CONDITIONS WILL
IMPROVE BY MID MORNING AS THE FRONT CONTINUES TO PUSH SOUTH.
&&
.FIRE WEATHER...
ISSUED AT 547 AM MDT WED OCT 3 2012
RH VALUES LOOK TO DROP TO WITHIN RED FLAG CRITERIA OVER MOST OF
THE AREA HOWEVER WINDS WILL REMAIN MARGINAL. THE BEST CHANCE FOR
RED FLAG CONDITIONS OVER THE NORTHWEST LATE THIS AFTERNOON. 06Z
NAM/GFS SHOW SUSTAINED WINDS THIS AFTERNOON IN THE 10 TO 20 MPH
ACROSS THE NORTH WITH GOOD MIXING EXPECTED GUSTS IN THE NORTH
SHOULD REACH 25 MPH. AS THE COLD FRONT DROPS SOUTH INTO THE
NORTHERN FRINGE OF OUR CWA WINDS SHOULD SHIFT TO THE NORTH AND
FURTHER INCREASE WITH GUSTS 30 TO 40 MPH. CONSIDERING THE TIMING
OF THE FRONT AND MODEL TRENDS I DECIDED TO ISSUE A RED FLAG
WARNING FOR OUR SOUTHWEST NEBRASKA COUNTIES AND YUMA COUNTY
COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ252.
NE...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR
NEZ079>081.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...DLF
AVIATION...PMM
FIRE WEATHER...DR
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1227 PM CDT WED OCT 3 2012
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 408 AM CDT WED OCT 3 2012
A COMPACT BUT STRONG STORM SYSTEM CONTINUED TO DEVELOP EARLY THIS
MORNING OVER WESTERN MONTANA. RAP ANALYSIS SHOWED A 90-KT JET
STREAK AT 400MB ROUNDING THE BASE OF THE DEVELOPING TROUGH AXIS.
ADDITIONAL JET STREAK ENERGY CONTINUED TO DIG SOUTHWARD TOWARD THE
BASE OF THE TROUGH. THE MID LEVEL COLD FRONT WAS MOVING TOWARD
YELLOWSTONE NATIONAL PARK AS OF 08Z. NEAR THE CENTER OF THIS
STORM...SNOW OBSERVATIONS WERE FOUND AT GREAT FALLS AND CUT BANK,
MONTANA WHERE TEMPERATURES CONTINUED TO FALL INTO THE LOWER 30S.
AHEAD OF THIS STORM SYSTEM...SKY WAS CLEAR ACROSS PRETTY MUCH THE
ENTIRE GREAT PLAINS. SURFACE LEE TROUGH EXTENDED FROM A WEAK LOW
CENTER (1003MB) JUST EAST OF CHADRON, NE SOUTH-SOUTHWESTWARD INTO
EASTERN COLORADO.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 408 AM CDT WED OCT 3 2012
THE STRONG COLD FRONT PUSHING SOUTH TODAY WILL REACH THE SOUTHERN
NEBRASKA PANHANDLE BY LATE AFTERNOON. A DOWNSLOPE WARM THERMAL
RIDGE WILL NOSE NORTHEAST THROUGH NORTHWEST KANSAS INTO CENTRAL
NEBRASKA...WHICH IS WHERE WARMEST SURFACE TEMPERATURES SHOULD BE
TODAY (WITH SCATTERED HIGHS IN THE 91 TO 93F RANGE)...MAINLY NORTH
OF THE DDC FORECAST AREA. ACROSS SOUTHWEST KANSAS...UPPER 80S SHOULD
BE COMMON FOR HIGHS WHICH WAS WHAT THE PREVIOUS FORECAST HAD...SO NO
CHANGE OF SIGNIFICANCE WAS MADE. SURFACE WINDS LATE AFTERNOON
SHOULD REACH 15 TO 18 KNOTS EAST OF A WAKEENEY TO LIBERAL LINE WHERE
LOW LEVEL PRESSURE GRADIENT WILL RESIDE. TIMING OF THE FRONT IS
COMING INTO BETTER FOCUS...AND WILL LEAN ON THE NAM12 FOR TIMING.
AT 06Z...FRONT SHOULD BE KNOCKING ON THE DOOR STEP OF THE DDC
FORECAST AREA (SYRACUSE TO WAKEENEY LINE). THE SUBSTANTIAL PRESSURE
RISES BEHIND THE FRONT COMBINED WITH THE GRADIENT ITSELF SHOULD
RESULT IN SURFACE WINDS OF 25 TO 28 KNOTS SUSTAINED FOR PROBABLY A
THREE-HOUR PERIOD. THIS WILL LIKELY WARRANT ISSUANCE OF A WIND
ADVISORY...BUT WILL HOLD OFF ON ISSUANCE OF ONE THIS FORECAST
CYCLE. WILL GO AHEAD AND KEEP THE 20 POPS IN FOR AREAS MAINLY NORTH
OF HIGHWAY 96 FOR LIGHT RAIN SHOWERS GIVEN SUCH STRONG LOW LEVEL
FRONTOGENESIS IN THE 06-12Z TIME FRAME TONIGHT. SREF MEANS AND
ECMWF MODEL DOES SHOW A SLIGHT QPF SIGNAL...BUT ABSENCE OF QUALITY
LOW LEVEL MOISTURE WILL BE AN ISSUE TO GENERATE ANYTHING MORE THAN
JUST A FEW HUNDREDTHS OF AN INCH OF PRECIPITATION SHOULD ANY RAIN
SHOWERS FORM AT ALL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 249 AM CDT WED OCT 3 2012
MEDIUM RANGE MODELS INDICATE A STRONG UPPER LEVEL TROUGH OF LOW
PRESSURE SWINGING EASTWARD OUT OF THE NORTHERN PLAINS INTO THE
WESTERN GREAT LAKES REGION THURSDAY. THIS SYSTEM WILL BRING THE
POSSIBILITY FOR PRECIP TO THE DAKOTAS, NEBRASKA, AND INTO THE UPPER
MIDWEST THURSDAY. ALTHOUGH AN ATTENDANT COLD FRONT IS PROJECTED TO
PUSH SOUTHEAST INTO AND ACROSS WESTERN KANSAS EARLY THURSDAY, LITTLE
IF ANY PRECIP WILL BE POSSIBLE ACROSS SOUTHWEST AND CENTRAL KANSAS
DUE TO THE LACK OF LOW/MID LEVEL MOISTURE AND INSTABILITY. HOWEVER,
A STRONG JET IS EXPECTED TO TRANSITION OUT OF THE NORTHERN AND
CENTRAL ROCKIES INTO THE WESTERN HIGH PLAINS THURSDAY PROVIDING
STRONG UPPER LEVEL DYNAMICS. SO, CANNOT RULE OUT AN OUTSIDE SLIGHT
CHANCE FOR LIGHT PRECIP AS FAR SOUTH AS CENTRAL KANSAS TO INCLUDE
THE I-70 CORRIDOR. OTHERWISE, GENERALLY DRY CONDITIONS ARE EXPECTED
ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS THROUGH FRIDAY AFTERNOON.
THERE IS A CHANCE FOR PRECIP FRIDAY NIGHT INTO EARLY SATURDAY AS A
SECONDARY UPPER LEVEL JET CORE EJECTS OUT OF THE ROCKIES INTO THE
WESTERN HIGH PLAINS. THIS WILL COINCIDE WITH A COOLING OF THE
ATMOSPHERE AT ALL LEVELS BRINGING GFS AND ECMWF SOUNDING PROFILES
TO NEAR SATURATION FRIDAY NIGHT INTO EARLY SATURDAY.
TEMPERATURES WILL BE WELL BELOW NORMAL THURSDAY IN WAKE OF A STRONG
COLD FRONT PUSHING SOUTHEAST ACROSS WESTERN KANSAS WEDNESDAY NIGHT.
STRONG COLD AIR ADVECTION SOUTHWARD INTO WESTERN KANSAS WILL LOWER
H85 TEMPERATURES DOWN INTO THE SINGLE DIGITS(C) ACROSS THE AREA
WITH NEAR 10C IN FAR SOUTHWESTERN KANSAS. TEMPERATURES ARE LIKELY
TO STRUGGLE TO REACH THE 60S(F) WITH MID TO UPPER 50S(F) POSSIBLE
FURTHER NORTH NEAR THE I-70 CORRIDOR. SIMILAR HIGH TEMPERATURES
ARE EXPECTED FRIDAY BEFORE ANOTHER SURGE OF COLDER AIR DROPS SOUTH
INTO WESTERN KANSAS EARLY IN THE WEEKEND. THIS WILL KEEP
TEMPERATURES DOWN BELOW NORMAL THROUGH VERY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1213 PM CDT WED OCT 3 2012
A STRONG UPPER LEVEL SHORTWAVE TROUGH WILL DIG INTO THE NORTHERN
PLAINS TODAY AND INTO THE UPPER MIDWEST TONIGHT. THIS SYSTEM WILL
DRIVE A STRONG COLD FRONT ACROSS WESTERN KANSAS OVERNIGHT. THE
COLD FRONT WILL SWITCH WINDS FROM THE SOUTH TO ABRUPTLY NORTH AT
25-35KT AT KHYS AROUND 04Z, KGCK AROUND 05Z, AND KDDC AROUND 06Z.
AHEAD OF THE FRONT SOUTH WINDS THIS AFTERNOON AROUND 15-25KT WILL
DECREASE TO SOUTH AROUND 10-15KT THIS EVENING. A POST FRONTAL STRATUS
DECK ALSO MAY FORM WITH CIGS BKN050-070BKN-OVC. AN ISOLATED ELEVATED
THUNDERSTORM IS ALSO POSSIBLE BEHIND THE COLD FRONT UNDERNEATH A
COLD POOL ALOFT WITH SOME MID LEVEL MOISTURE.
&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 46 62 42 / 0 10 0 10
GCK 87 45 62 42 / 0 10 0 10
EHA 88 45 61 42 / 0 10 0 0
LBL 88 47 62 43 / 0 10 0 0
HYS 87 45 61 40 / 0 20 10 10
P28 86 52 64 46 / 0 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
548 AM MDT WED OCT 3 2012
.UPDATE...
ISSUED AT 547 AM MDT WED OCT 3 2012
ISSUED RED FLAG WARNING FOR SOUTHWEST NEBRASKA COUNTIES AND YUMA
COUNTY COLORADO. SEE FIRE SECTION FOR DETAILS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 247 AM MDT WED OCT 3 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS A SHORTWAVE RIDGE
EXTENDING NORTH ACROSS NORTHWEST KANSAS AND CENTRAL NEBRASKA.
UPSTREAM A TROUGH IS DIGGING SOUTH INTO NORTHERN IDAHO AND
WESTERN MONTANA. AT THE SURFACE...LOW PRESSURE REMAINS IN PLACE
ACROSS THE HIGH PLAINS WITH A SURFACE COLD FRONT DEEPENING ACROSS
SOUTH DAKOTA...AND A SURFACE TROUGH AXIS EXTENDING JUST WEST OF
THE COLORADO/KANSAS STATE LINE.
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS IN THE UPPER
80S/LOW 90S AS SOUTHERLY FLOW ADVECTS MUCH WARMER AIR INTO THE
REGION AHEAD OF THE APPROACHING COLD FRONT.
TONIGHT...THE COLD FRONT OVER SOUTH DAKOTA IS EXPECTED TO PUSH
SOUTH ACROSS THE CWA BY MIDNIGHT AS THE SHORTWAVE TROUGH DIGS
SOUTH AND EAST ACROSS THE NORTHERN PLAINS. WINDY CONDITIONS ARE
EXPECTED THIS EVENING AND OVERNIGHT BEHIND THE FRONT...AND WILL
APPROACH WIND ADVISORY CRITERIA WITH GUSTS POSSIBLY IN THE 40-45
MPH RANGE. I WAS NOT CONFIDENT ENOUGH TO GO THAT HIGH YET WITH
SOME DIFFERENCES BETWEEN GUIDANCE ON MAGNITUDE OF THE WINDS...AND
THE WINDOW FOR THESE CONDITIONS SEEMS TO BE FAIRLY BRIEF. A FEW
SHOWERS WILL BE POSSIBLE MAINLY IN THE 03Z- 09Z TIME FRAME WHEN
BEST LARGE SCALE ASCENT IS ADVERTISED. DUE TO THE SPEED AND
NORTHERN TRACK OF THE TROUGH AND MINIMAL MOISTURE...CONFIDENCE IS
LOW IN MEASURABLE PRECIP. I KEPT POPS LIMITED TO SLIGHT CHANCE
CATEGORY FOR NOW...AND CONSIDERED ONLY INCLUDING MENTION OF
SPRINKLES.
THURSDAY...COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN THE
50S/60S AND OVERNIGHT LOWS THURSDAY NIGHT IN THE MID 30S. WIND AND
INCREASING CLOUDS WILL LIMIT RADIATION COOLING THURSDAY
NIGHT...OTHERWISE I WOULD BE CONCERNED WITH HARD FREEZE CONDITIONS
BASED ON ADVERTISED H85 TEMPS IN THE 0C-3C RANGE. FOR NOW IT
LOOKS LIKE WE WILL BE IN THE UPPER LIMIT OF LOCAL FROST ADVISORY
CRITERIA.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 247 AM MDT WED OCT 3 2012
THE ANTICIPATED SIGNIFICANT WEATHER CHANGE STILL LOOKS ON TRACK
FOR THE WEEKEND AS A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH IS
FORECAST TO SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND
SATURDAY. DYNAMICS FROM A 105 KT JET AT 250 MB WILL ENHANCE LIFT
FRIDAY NIGHT INTO SATURDAY MORNING WHEN BOTH THE GFS/EC FORECAST A
SATURATED LOWER ATMOSPHERE. GIVEN 850 MB TEMPS OF ZERO TO -2C AND
SATURATED AIR ABOVE -10C...ANTICIPATE LIGHT SNOW ACROSS THE
COLORADO COUNTIES SATURDAY MORNING AND A RAIN-SNOW MIX POSSIBLE
FURTHER EAST. GUIDANCE SUGGESTS LOW AND MID LEVELS WILL RAPIDLY
DRY OUT SATURDAY AFTERNOON AS THE JET AXIS AND UPPER TROUGH SLIDE
SOUTHEAST OF THE FORECAST AREA...ENDING PRECIP CHANCES.
850 MB TEMPERATURES OF 0 TO -2C ARE FORECAST SATURDAY MORNING...
WARMING ONLY A FEW DEGREES BY LATE AFTERNOON. HIGHS WILL HOLD IN THE
40S WHICH IS 25-30 DEGREES BELOW NORMAL. THE NORTHWEST THIRD OF THE
AREA SHOULD SEE MIN TEMPS SATURDAY IN THE 30-32 F RANGE AND BY
SUNDAY MORNING WITH LESS CLOUDS...MIN TEMPERATURES COULD DROP AS LOW
AS THE UPPER 20S...MAINLY IN THE NORTHWEST...WITH LOW 30S ELSEWHERE.
AFTERNOON HIGH TEMPERATURES WILL MODERATE SUNDAY AND MONDAY WITH
TEMPS STILL BELOW NORMAL BUT RETURNING TO THE 50S SUNDAY AND 60S
MONDAY. BOTH GFS/EC HINT AT ANOTHER COLD FRONT ARRIVING TUESDAY
WITH THE AIR MASS MOVING THROUGH RATHER QUICKLY...AND THE
POTENTIAL FOR PRECIPITATION AROUND MID WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 510 AM MDT WED OCT 3 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. SOUTHERLY WINDS AROUND 10KTS WILL SHIFT TO THE NORTH
AFTER SUNSET AND INCREASE AS A COLD FRONT MOVES THROUGH THE
REGION THIS EVENING. GUSTS AROUND 30KTS WILL BE POSSIBLE AT BOTH
TERMINALS. A FEW SHOWERS WILL BE POSSIBLE...HOWEVER COVERAGE LOOKS
TO BE LIMITED SO WILL NOT MENTION IN TAFS.
&&
.FIRE WEATHER...
ISSUED AT 547 AM MDT WED OCT 3 2012
RH VALUES LOOK TO DROP TO WITHIN RED FLAG CRITERIA OVER MOST OF
THE AREA HOWEVER WINDS WILL REMAIN MARGINAL. THE BEST CHANCE FOR
RED FLAG CONDITIONS OVER THE NORTHWEST LATE THIS AFTERNOON. 06Z
NAM/GFS SHOW SUSTAINED WINDS THIS AFTERNOON IN THE 10 TO 20 MPH
ACROSS THE NORTH WITH GOOD MIXING EXPECTED GUSTS IN THE NORTH
SHOULD REACH 25 MPH. AS THE COLD FRONT DROPS SOUTH INTO THE
NORTHERN FRINGE OF OUR CWA WINDS SHOULD SHIFT TO THE NORTH AND
FURTHER INCREASE WITH GUSTS 30 TO 40 MPH. CONSIDERING THE TIMING
OF THE FRONT AND MODEL TRENDS I DECIDED TO ISSUE A RED FLAG
WARNING FOR OUR SOUTHWEST NEBRASKA COUNTIES AND YUMA COUNTY
COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
COZ252.
NE...RED FLAG WARNING FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10
PM CDT/ THIS EVENING FOR NEZ079>081.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...DLF
AVIATION...DR
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 AM CDT WED OCT 3 2012
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 408 AM CDT WED OCT 3 2012
A COMPACT BUT STRONG STORM SYSTEM CONTINUED TO DEVELOP EARLY THIS
MORNING OVER WESTERN MONTANA. RAP ANALYSIS SHOWED A 90-KT JET
STREAK AT 400MB ROUNDING THE BASE OF THE DEVELOPING TROUGH AXIS.
ADDITIONAL JET STREAK ENERGY CONTINUED TO DIG SOUTHWARD TOWARD THE
BASE OF THE TROUGH. THE MID LEVEL COLD FRONT WAS MOVING TOWARD
YELLOWSTONE NATIONAL PARK AS OF 08Z. NEAR THE CENTER OF THIS
STORM...SNOW OBSERVATIONS WERE FOUND AT GREAT FALLS AND CUT BANK,
MONTANA WHERE TEMPERATURES CONTINUED TO FALL INTO THE LOWER 30S.
AHEAD OF THIS STORM SYSTEM...SKY WAS CLEAR ACROSS PRETTY MUCH THE
ENTIRE GREAT PLAINS. SURFACE LEE TROUGH EXTENDED FROM A WEAK LOW
CENTER (1003MB) JUST EAST OF CHADRON, NE SOUTH-SOUTHWESTWARD INTO
EASTERN COLORADO.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 408 AM CDT WED OCT 3 2012
THE STRONG COLD FRONT PUSHING SOUTH TODAY WILL REACH THE SOUTHERN
NEBRASKA PANHANDLE BY LATE AFTERNOON. A DOWNSLOPE WARM THERMAL
RIDGE WILL NOSE NORTHEAST THROUGH NORTHWEST KANSAS INTO CENTRAL
NEBRASKA...WHICH IS WHERE WARMEST SURFACE TEMPERATURES SHOULD BE
TODAY (WITH SCATTERED HIGHS IN THE 91 TO 93F RANGE)...MAINLY NORTH
OF THE DDC FORECAST AREA. ACROSS SOUTHWEST KANSAS...UPPER 80S SHOULD
BE COMMON FOR HIGHS WHICH WAS WHAT THE PREVIOUS FORECAST HAD...SO NO
CHANGE OF SIGNIFICANCE WAS MADE. SURFACE WINDS LATE AFTERNOON
SHOULD REACH 15 TO 18 KNOTS EAST OF A WAKEENEY TO LIBERAL LINE WHERE
LOW LEVEL PRESSURE GRADIENT WILL RESIDE. TIMING OF THE FRONT IS
COMING INTO BETTER FOCUS...AND WILL LEAN ON THE NAM12 FOR TIMING.
AT 06Z...FRONT SHOULD BE KNOCKING ON THE DOOR STEP OF THE DDC
FORECAST AREA (SYRACUSE TO WAKEENEY LINE). THE SUBSTANTIAL PRESSURE
RISES BEHIND THE FRONT COMBINED WITH THE GRADIENT ITSELF SHOULD
RESULT IN SURFACE WINDS OF 25 TO 28 KNOTS SUSTAINED FOR PROBABLY A
THREE-HOUR PERIOD. THIS WILL LIKELY WARRANT ISSUANCE OF A WIND
ADVISORY...BUT WILL HOLD OFF ON ISSUANCE OF ONE THIS FORECAST
CYCLE. WILL GO AHEAD AND KEEP THE 20 POPS IN FOR AREAS MAINLY NORTH
OF HIGHWAY 96 FOR LIGHT RAIN SHOWERS GIVEN SUCH STRONG LOW LEVEL
FRONTOGENESIS IN THE 06-12Z TIME FRAME TONIGHT. SREF MEANS AND
ECMWF MODEL DOES SHOW A SLIGHT QPF SIGNAL...BUT ABSENCE OF QUALITY
LOW LEVEL MOISTURE WILL BE AN ISSUE TO GENERATE ANYTHING MORE THAN
JUST A FEW HUNDREDTHS OF AN INCH OF PRECIPITATION SHOULD ANY RAIN
SHOWERS FORM AT ALL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 249 AM CDT WED OCT 3 2012
MEDIUM RANGE MODELS INDICATE A STRONG UPPER LEVEL TROUGH OF LOW
PRESSURE SWINGING EASTWARD OUT OF THE NORTHERN PLAINS INTO THE
WESTERN GREAT LAKES REGION THURSDAY. THIS SYSTEM WILL BRING THE
POSSIBILITY FOR PRECIP TO THE DAKOTAS, NEBRASKA, AND INTO THE UPPER
MIDWEST THURSDAY. ALTHOUGH AN ATTENDANT COLD FRONT IS PROJECTED TO
PUSH SOUTHEAST INTO AND ACROSS WESTERN KANSAS EARLY THURSDAY, LITTLE
IF ANY PRECIP WILL BE POSSIBLE ACROSS SOUTHWEST AND CENTRAL KANSAS
DUE TO THE LACK OF LOW/MID LEVEL MOISTURE AND INSTABILITY. HOWEVER,
A STRONG JET IS EXPECTED TO TRANSITION OUT OF THE NORTHERN AND
CENTRAL ROCKIES INTO THE WESTERN HIGH PLAINS THURSDAY PROVIDING
STRONG UPPER LEVEL DYNAMICS. SO, CANNOT RULE OUT AN OUTSIDE SLIGHT
CHANCE FOR LIGHT PRECIP AS FAR SOUTH AS CENTRAL KANSAS TO INCLUDE
THE I-70 CORRIDOR. OTHERWISE, GENERALLY DRY CONDITIONS ARE EXPECTED
ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS THROUGH FRIDAY AFTERNOON.
THERE IS A CHANCE FOR PRECIP FRIDAY NIGHT INTO EARLY SATURDAY AS A
SECONDARY UPPER LEVEL JET CORE EJECTS OUT OF THE ROCKIES INTO THE
WESTERN HIGH PLAINS. THIS WILL COINCIDE WITH A COOLING OF THE
ATMOSPHERE AT ALL LEVELS BRINGING GFS AND ECMWF SOUNDING PROFILES
TO NEAR SATURATION FRIDAY NIGHT INTO EARLY SATURDAY.
TEMPERATURES WILL BE WELL BELOW NORMAL THURSDAY IN WAKE OF A STRONG
COLD FRONT PUSHING SOUTHEAST ACROSS WESTERN KANSAS WEDNESDAY NIGHT.
STRONG COLD AIR ADVECTION SOUTHWARD INTO WESTERN KANSAS WILL LOWER
H85 TEMPERATURES DOWN INTO THE SINGLE DIGITS(C) ACROSS THE AREA
WITH NEAR 10C IN FAR SOUTHWESTERN KANSAS. TEMPERATURES ARE LIKELY
TO STRUGGLE TO REACH THE 60S(F) WITH MID TO UPPER 50S(F) POSSIBLE
FURTHER NORTH NEAR THE I-70 CORRIDOR. SIMILAR HIGH TEMPERATURES
ARE EXPECTED FRIDAY BEFORE ANOTHER SURGE OF COLDER AIR DROPS SOUTH
INTO WESTERN KANSAS EARLY IN THE WEEKEND. THIS WILL KEEP
TEMPERATURES DOWN BELOW NORMAL THROUGH VERY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 614 AM CDT WED OCT 3 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH LATE THIS
EVENING. AS FOR WINDS, A LEE SIDE TROUGH OF LOW PRESSURE WILL
STRENGTHEN ACROSS EXTREME EASTERN COLORADO TODAY. AS A RESULT,
SOUTH TO SOUTHWESTERLY WINDS OF 5 TO 15KT EARLY THIS MORNING WILL
INCREASE UP TO 15 TO 25KT BY EARLY THIS AFTERNOON. A STRONG COLD
FRONT IS THEN EXPECTED TO PUSH SOUTHEAST INTO AND ACROSS WESTERN
KANSAS TONIGHT. WINDS WILL BECOME NORTHERLY 25 TO 35KT BEHIND THE
FRONT...GENERALLY AFTER 06Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 46 62 42 / 0 10 0 10
GCK 87 45 62 42 / 0 10 0 10
EHA 88 45 61 42 / 0 10 0 0
LBL 88 47 62 43 / 0 10 0 0
HYS 87 45 61 40 / 0 20 10 10
P28 86 52 64 46 / 0 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
511 AM MDT WED OCT 3 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 247 AM MDT WED OCT 3 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS A SHORTWAVE RIDGE
EXTENDING NORTH ACROSS NORTHWEST KANSAS AND CENTRAL NEBRASKA.
UPSTREAM A TROUGH IS DIGGING SOUTH INTO NORTHERN IDAHO AND
WESTERN MONTANA. AT THE SURFACE...LOW PRESSURE REMAINS IN PLACE
ACROSS THE HIGH PLAINS WITH A SURFACE COLD FRONT DEEPENING ACROSS
SOUTH DAKOTA...AND A SURFACE TROUGH AXIS EXTENDING JUST WEST OF
THE COLORADO/KANSAS STATE LINE.
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS IN THE UPPER
80S/LOW 90S AS SOUTHERLY FLOW ADVECTS MUCH WARMER AIR INTO THE
REGION AHEAD OF THE APPROACHING COLD FRONT.
TONIGHT...THE COLD FRONT OVER SOUTH DAKOTA IS EXPECTED TO PUSH
SOUTH ACROSS THE CWA BY MIDNIGHT AS THE SHORTWAVE TROUGH DIGS
SOUTH AND EAST ACROSS THE NORTHERN PLAINS. WINDY CONDITIONS ARE
EXPECTED THIS EVENING AND OVERNIGHT BEHIND THE FRONT...AND WILL
APPROACH WIND ADVISORY CRITERIA WITH GUSTS POSSIBLY IN THE 40-45
MPH RANGE. I WAS NOT CONFIDENT ENOUGH TO GO THAT HIGH YET WITH
SOME DIFFERENCES BETWEEN GUIDANCE ON MAGNITUDE OF THE WINDS...AND
THE WINDOW FOR THESE CONDITIONS SEEMS TO BE FAIRLY BRIEF. A FEW
SHOWERS WILL BE POSSIBLE MAINLY IN THE 03Z- 09Z TIME FRAME WHEN
BEST LARGE SCALE ASCENT IS ADVERTISED. DUE TO THE SPEED AND
NORTHERN TRACK OF THE TROUGH AND MINIMAL MOISTURE...CONFIDENCE IS
LOW IN MEASURABLE PRECIP. I KEPT POPS LIMITED TO SLIGHT CHANCE
CATEGORY FOR NOW...AND CONSIDERED ONLY INCLUDING MENTION OF
SPRINKLES.
THURSDAY...COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN THE
50S/60S AND OVERNIGHT LOWS THURSDAY NIGHT IN THE MID 30S. WIND AND
INCREASING CLOUDS WILL LIMIT RADIATION COOLING THURSDAY
NIGHT...OTHERWISE I WOULD BE CONCERNED WITH HARD FREEZE CONDITIONS
BASED ON ADVERTISED H85 TEMPS IN THE 0C-3C RANGE. FOR NOW IT
LOOKS LIKE WE WILL BE IN THE UPPER LIMIT OF LOCAL FROST ADVISORY
CRITERIA.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 247 AM MDT WED OCT 3 2012
THE ANTICIPATED SIGNIFICANT WEATHER CHANGE STILL LOOKS ON TRACK
FOR THE WEEKEND AS A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH IS
FORECAST TO SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND
SATURDAY. DYNAMICS FROM A 105 KT JET AT 250 MB WILL ENHANCE LIFT
FRIDAY NIGHT INTO SATURDAY MORNING WHEN BOTH THE GFS/EC FORECAST A
SATURATED LOWER ATMOSPHERE. GIVEN 850 MB TEMPS OF ZERO TO -2C AND
SATURATED AIR ABOVE -10C...ANTICIPATE LIGHT SNOW ACROSS THE
COLORADO COUNTIES SATURDAY MORNING AND A RAIN-SNOW MIX POSSIBLE
FURTHER EAST. GUIDANCE SUGGESTS LOW AND MID LEVELS WILL RAPIDLY
DRY OUT SATURDAY AFTERNOON AS THE JET AXIS AND UPPER TROUGH SLIDE
SOUTHEAST OF THE FORECAST AREA...ENDING PRECIP CHANCES.
850 MB TEMPERATURES OF 0 TO -2C ARE FORECAST SATURDAY MORNING...
WARMING ONLY A FEW DEGREES BY LATE AFTERNOON. HIGHS WILL HOLD IN THE
40S WHICH IS 25-30 DEGREES BELOW NORMAL. THE NORTHWEST THIRD OF THE
AREA SHOULD SEE MIN TEMPS SATURDAY IN THE 30-32 F RANGE AND BY
SUNDAY MORNING WITH LESS CLOUDS...MIN TEMPERATURES COULD DROP AS LOW
AS THE UPPER 20S...MAINLY IN THE NORTHWEST...WITH LOW 30S ELSEWHERE.
AFTERNOON HIGH TEMPERATURES WILL MODERATE SUNDAY AND MONDAY WITH
TEMPS STILL BELOW NORMAL BUT RETURNING TO THE 50S SUNDAY AND 60S
MONDAY. BOTH GFS/EC HINT AT ANOTHER COLD FRONT ARRIVING TUESDAY
WITH THE AIR MASS MOVING THROUGH RATHER QUICKLY...AND THE
POTENTIAL FOR PRECIPITATION AROUND MID WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 510 AM MDT WED OCT 3 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. SOUTHERLY WINDS AROUND 10KTS WILL SHIFT TO THE NORTH
AFTER SUNSET AND INCREASE AS A COLD FRONT MOVES THROUGH THE
REGION THIS EVENING. GUSTS AROUND 30KTS WILL BE POSSIBLE AT BOTH
TERMINALS. A FEW SHOWERS WILL BE POSSIBLE...HOWEVER COVERAGE LOOKS
TO BE LIMITED SO WILL NOT MENTION IN TAFS.
&&
.FIRE WEATHER...
ISSUED AT 247 AM MDT WED OCT 3 2012
RH VALUES LOOK TO DROP TO WITHIN RED FLAG CRITERIA OVER MOST OF
THE AREA HOWEVER WINDS WILL REMAIN MARGINAL...WITH THE BEST CHANCE
FOR RED FLAG CONDITIONS OVER THE NORTHWEST LATE THIS AFTERNOON.
WINDS WILL INCREASE THIS EVENING...HOWEVER BY THAT POINT RH SHOULD
RECOVER ABOVE CRITERIA. I DO NOT PLAN ON A RFW AT THIS
TIME...SINCE WE LIKELY WONT MEET THE 3HR REQUIREMENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...DLF
AVIATION...DR
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
410 AM CDT WED OCT 3 2012
...UPDATED SYNOPSIS AND SHORT TERM SECTIONS...
.SYNOPSIS...
ISSUED AT 408 AM CDT WED OCT 3 2012
A COMPACT BUT STRONG STORM SYSTEM CONTINUED TO DEVELOP EARLY THIS
MORNING OVER WESTERN MONTANA. RAP ANALYSIS SHOWED A 90-KT JET
STREAK AT 400MB ROUNDING THE BASE OF THE DEVELOPING TROUGH AXIS.
ADDITIONAL JET STREAK ENERGY CONTINUED TO DIG SOUTHWARD TOWARD THE
BASE OF THE TROUGH. THE MID LEVEL COLD FRONT WAS MOVING TOWARD
YELLOWSTONE NATIONAL PARK AS OF 08Z. NEAR THE CENTER OF THIS
STORM...SNOW OBSERVATIONS WERE FOUND AT GREAT FALLS AND CUT BANK,
MONTANA WHERE TEMPERATURES CONTINUED TO FALL INTO THE LOWER 30S.
AHEAD OF THIS STORM SYSTEM...SKY WAS CLEAR ACROSS PRETTY MUCH THE
ENTIRE GREAT PLAINS. SURFACE LEE TROUGH EXTENDED FROM A WEAK LOW
CENTER (1003MB) JUST EAST OF CHADRON, NE SOUTH-SOUTHWESTWARD INTO
EASTERN COLORADO.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 408 AM CDT WED OCT 3 2012
THE STRONG COLD FRONT PUSHING SOUTH TODAY WILL REACH THE SOUTHERN
NEBRASKA PANHANDLE BY LATE AFTERNOON. A DOWNSLOPE WARM THERMAL
RIDGE WILL NOSE NORTHEAST THROUGH NORTHWEST KANSAS INTO CENTRAL
NEBRASKA...WHICH IS WHERE WARMEST SURFACE TEMPERATURES SHOULD BE
TODAY (WITH SCATTERED HIGHS IN THE 91 TO 93F RANGE)...MAINLY NORTH
OF THE DDC FORECAST AREA. ACROSS SOUTHWEST KANSAS...UPPER 80S SHOULD
BE COMMON FOR HIGHS WHICH WAS WHAT THE PREVIOUS FORECAST HAD...SO NO
CHANGE OF SIGNIFICANCE WAS MADE. SURFACE WINDS LATE AFTERNOON
SHOULD REACH 15 TO 18 KNOTS EAST OF A WAKEENEY TO LIBERAL LINE WHERE
LOW LEVEL PRESSURE GRADIENT WILL RESIDE. TIMING OF THE FRONT IS
COMING INTO BETTER FOCUS...AND WILL LEAN ON THE NAM12 FOR TIMING.
AT 06Z...FRONT SHOULD BE KNOCKING ON THE DOOR STEP OF THE DDC
FORECAST AREA (SYRACUSE TO WAKEENEY LINE). THE SUBSTANTIAL PRESSURE
RISES BEHIND THE FRONT COMBINED WITH THE GRADIENT ITSELF SHOULD
RESULT IN SURFACE WINDS OF 25 TO 28 KNOTS SUSTAINED FOR PROBABLY A
THREE-HOUR PERIOD. THIS WILL LIKELY WARRANT ISSUANCE OF A WIND
ADVISORY...BUT WILL HOLD OFF ON ISSUANCE OF ONE THIS FORECAST
CYCLE. WILL GO AHEAD AND KEEP THE 20 POPS IN FOR AREAS MAINLY NORTH
OF HIGHWAY 96 FOR LIGHT RAIN SHOWERS GIVEN SUCH STRONG LOW LEVEL
FRONTOGENESIS IN THE 06-12Z TIME FRAME TONIGHT. SREF MEANS AND
ECMWF MODEL DOES SHOW A SLIGHT QPF SIGNAL...BUT ABSENCE OF QUALITY
LOW LEVEL MOISTURE WILL BE AN ISSUE TO GENERATE ANYTHING MORE THAN
JUST A FEW HUNDREDTHS OF AN INCH OF PRECIPITATION SHOULD ANY RAIN
SHOWERS FORM AT ALL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 249 AM CDT WED OCT 3 2012
MEDIUM RANGE MODELS INDICATE A STRONG UPPER LEVEL TROUGH OF LOW
PRESSURE SWINGING EASTWARD OUT OF THE NORTHERN PLAINS INTO THE
WESTERN GREAT LAKES REGION THURSDAY. THIS SYSTEM WILL BRING THE
POSSIBILITY FOR PRECIP TO THE DAKOTAS, NEBRASKA, AND INTO THE UPPER
MIDWEST THURSDAY. ALTHOUGH AN ATTENDANT COLD FRONT IS PROJECTED TO
PUSH SOUTHEAST INTO AND ACROSS WESTERN KANSAS EARLY THURSDAY, LITTLE
IF ANY PRECIP WILL BE POSSIBLE ACROSS SOUTHWEST AND CENTRAL KANSAS
DUE TO THE LACK OF LOW/MID LEVEL MOISTURE AND INSTABILITY. HOWEVER,
A STRONG JET IS EXPECTED TO TRANSITION OUT OF THE NORTHERN AND
CENTRAL ROCKIES INTO THE WESTERN HIGH PLAINS THURSDAY PROVIDING
STRONG UPPER LEVEL DYNAMICS. SO, CANNOT RULE OUT AN OUTSIDE SLIGHT
CHANCE FOR LIGHT PRECIP AS FAR SOUTH AS CENTRAL KANSAS TO INCLUDE
THE I-70 CORRIDOR. OTHERWISE, GENERALLY DRY CONDITIONS ARE EXPECTED
ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS THROUGH FRIDAY AFTERNOON.
THERE IS A CHANCE FOR PRECIP FRIDAY NIGHT INTO EARLY SATURDAY AS A
SECONDARY UPPER LEVEL JET CORE EJECTS OUT OF THE ROCKIES INTO THE
WESTERN HIGH PLAINS. THIS WILL COINCIDE WITH A COOLING OF THE
ATMOSPHERE AT ALL LEVELS BRINGING GFS AND ECMWF SOUNDING PROFILES
TO NEAR SATURATION FRIDAY NIGHT INTO EARLY SATURDAY.
TEMPERATURES WILL BE WELL BELOW NORMAL THURSDAY IN WAKE OF A STRONG
COLD FRONT PUSHING SOUTHEAST ACROSS WESTERN KANSAS WEDNESDAY NIGHT.
STRONG COLD AIR ADVECTION SOUTHWARD INTO WESTERN KANSAS WILL LOWER
H85 TEMPERATURES DOWN INTO THE SINGLE DIGITS(C) ACROSS THE AREA
WITH NEAR 10C IN FAR SOUTHWESTERN KANSAS. TEMPERATURES ARE LIKELY
TO STRUGGLE TO REACH THE 60S(F) WITH MID TO UPPER 50S(F) POSSIBLE
FURTHER NORTH NEAR THE I-70 CORRIDOR. SIMILAR HIGH TEMPERATURES
ARE EXPECTED FRIDAY BEFORE ANOTHER SURGE OF COLDER AIR DROPS SOUTH
INTO WESTERN KANSAS EARLY IN THE WEEKEND. THIS WILL KEEP
TEMPERATURES DOWN BELOW NORMAL THROUGH VERY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1225 AM CDT WED OCT 3 2012
LEE TROUGH DEVELOPMENT FROM EASTERN COLORADO INTO WESTERN NEBRASKA
WILL KEEP SURFACE WINDS FROM THE SOUTH AT GCK, DDC, HYS TERMINALS.
WIND SPEEDS WILL BE 8 TO 10 KNOTS THIS MORNING WITH AN INCREASE IN
WIND SPEEDS MID-LATE MORNING TO 15 TO 18 KNOTS. A STRONG COLD
FRONT WILL APPROACH LATE THIS EVENING WITH A WIND SHIFT TO THE
NORTH AND AN ABRUPT INCREASE IN SPEED. THE FRONT IS EXPECTED
AROUND 05-07Z TIME FRAME (RIGHT AT THE END OF THE CURRENT TAF
PERIOD) WITH 24 TO 28 KNOT WINDS FROM THE NORTH UPON PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 46 62 42 / 0 10 0 10
GCK 87 45 62 42 / 0 10 0 10
EHA 88 45 61 42 / 0 10 0 0
LBL 88 47 62 43 / 0 10 0 0
HYS 87 45 61 40 / 0 20 10 10
P28 86 52 64 46 / 0 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS GOODLAND KS
247 AM MDT WED OCT 3 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 247 AM MDT WED OCT 3 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS A SHORTWAVE RIDGE
EXTENDING NORTH ACROSS NORTHWEST KANSAS AND CENTRAL NEBRASKA.
UPSTREAM A TROUGH IS DIGGING SOUTH INTO NORTHERN IDAHO AND
WESTERN MONTANA. AT THE SURFACE...LOW PRESSURE REMAINS IN PLACE
ACROSS THE HIGH PLAINS WITH A SURFACE COLD FRONT DEEPENING ACROSS
SOUTH DAKOTA...AND A SURFACE TROUGH AXIS EXTENDING JUST WEST OF
THE COLORADO/KANSAS STATE LINE.
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS IN THE UPPER
80S/LOW 90S AS SOUTHERLY FLOW ADVECTS MUCH WARMER AIR INTO THE
REGION AHEAD OF THE APPROACHING COLD FRONT.
TONIGHT...THE COLD FRONT OVER SOUTH DAKOTA IS EXPECTED TO PUSH
SOUTH ACROSS THE CWA BY MIDNIGHT AS THE SHORTWAVE TROUGH DIGS
SOUTH AND EAST ACROSS THE NORTHERN PLAINS. WINDY CONDITIONS ARE
EXPECTED THIS EVENING AND OVERNIGHT BEHIND THE FRONT...AND WILL
APPROACH WIND ADVISORY CRITERIA WITH GUSTS POSSIBLY IN THE 40-45
MPH RANGE. I WAS NOT CONFIDENT ENOUGH TO GO THAT HIGH YET WITH
SOME DIFFERENCES BETWEEN GUIDANCE ON MAGNITUDE OF THE WINDS...AND
THE WINDOW FOR THESE CONDITIONS SEEMS TO BE FAIRLY BRIEF. A FEW
SHOWERS WILL BE POSSIBLE MAINLY IN THE 03Z- 09Z TIME FRAME WHEN
BEST LARGE SCALE ASCENT IS ADVERTISED. DUE TO THE SPEED AND
NORTHERN TRACK OF THE TROUGH AND MINIMAL MOISTURE...CONFIDENCE IS
LOW IN MEASURABLE PRECIP. I KEPT POPS LIMITED TO SLIGHT CHANCE
CATEGORY FOR NOW...AND CONSIDERED ONLY INCLUDING MENTION OF
SPRINKLES.
THURSDAY...COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN THE
50S/60S AND OVERNIGHT LOWS THURSDAY NIGHT IN THE MID 30S. WIND AND
INCREASING CLOUDS WILL LIMIT RADIATION COOLING THURSDAY
NIGHT...OTHERWISE I WOULD BE CONCERNED WITH HARD FREEZE CONDITIONS
BASED ON ADVERTISED H85 TEMPS IN THE 0C-3C RANGE. FOR NOW IT
LOOKS LIKE WE WILL BE IN THE UPPER LIMIT OF LOCAL FROST ADVISORY
CRITERIA.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 247 AM MDT WED OCT 3 2012
THE ANTICIPATED SIGNIFICANT WEATHER CHANGE STILL LOOKS ON TRACK
FOR THE WEEKEND AS A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH IS
FORECAST TO SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND
SATURDAY. DYNAMICS FROM A 105 KT JET AT 250 MB WILL ENHANCE LIFT
FRIDAY NIGHT INTO SATURDAY MORNING WHEN BOTH THE GFS/EC FORECAST A
SATURATED LOWER ATMOSPHERE. GIVEN 850 MB TEMPS OF ZERO TO -2C AND
SATURATED AIR ABOVE -10C...ANTICIPATE LIGHT SNOW ACROSS THE
COLORADO COUNTIES SATURDAY MORNING AND A RAIN-SNOW MIX POSSIBLE
FURTHER EAST. GUIDANCE SUGGESTS LOW AND MID LEVELS WILL RAPIDLY
DRY OUT SATURDAY AFTERNOON AS THE JET AXIS AND UPPER TROUGH SLIDE
SOUTHEAST OF THE FORECAST AREA...ENDING PRECIP CHANCES.
850 MB TEMPERATURES OF 0 TO -2C ARE FORECAST SATURDAY MORNING...
WARMING ONLY A FEW DEGREES BY LATE AFTERNOON. HIGHS WILL HOLD IN THE
40S WHICH IS 25-30 DEGREES BELOW NORMAL. THE NORTHWEST THIRD OF THE
AREA SHOULD SEE MIN TEMPS SATURDAY IN THE 30-32 F RANGE AND BY
SUNDAY MORNING WITH LESS CLOUDS...MIN TEMPERATURES COULD DROP AS LOW
AS THE UPPER 20S...MAINLY IN THE NORTHWEST...WITH LOW 30S ELSEWHERE.
AFTERNOON HIGH TEMPERATURES WILL MODERATE SUNDAY AND MONDAY WITH
TEMPS STILL BELOW NORMAL BUT RETURNING TO THE 50S SUNDAY AND 60S
MONDAY. BOTH GFS/EC HINT AT ANOTHER COLD FRONT ARRIVING TUESDAY
WITH THE AIR MASS MOVING THROUGH RATHER QUICKLY...AND THE
POTENTIAL FOR PRECIPITATION AROUND MID WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1121 PM MDT TUE OCT 2 2012
VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH THE PERIOD. A COLD
FRONT WILL MOVE THROUGH BOTH TERMINALS LATE WEDNESDAY
AFTERNOON/EARLY EVENING WITH A WIND SHIFT TO THE NORTH AND WIND
SPEEDS INCREASING TO 20 TO 30KTS WEDNESDAY NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 247 AM MDT WED OCT 3 2012
RH VALUES LOOK TO DROP TO WITHIN RED FLAG CRITERIA OVER MOST OF
THE AREA HOWEVER WINDS WILL REMAIN MARGINAL...WITH THE BEST CHANCE
FOR RED FLAG CONDITIONS OVER THE NORTHWEST LATE THIS AFTERNOON.
WINDS WILL INCREASE THIS EVENING...HOWEVER BY THAT POINT RH SHOULD
RECOVER ABOVE CRITERIA. I DO NOT PLAN ON A RFW AT THIS
TIME...SINCE WE LIKELY WONT MEET THE 3HR REQUIREMENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...DLF
AVIATION...024
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
805 PM EDT THU OCT 4 2012
.SYNOPSIS...
ISSUED AT 354 PM EDT THU OCT 4 2012
A STRONG COLD FRONT WILL CROSS THE AREA THIS EVENING WITH SHOWERS
AND SCATTERED THUNDERSTORMS. SKIES WILL CLEAR LATE TONIGHT AND IT
WILL TURN COLDER. EXPECT MOSTLY SUNNY SKIES FRIDAY WITH HIGHS ONLY
IN THE 50S. LAKE EFFECT RAIN SHOWERS ARE EXPECTED SATURDAY INTO
SUNDAY WITH HIGHS MOSTLY IN THE 4OS.
&&
.UPDATE...
ISSUED AT 805 PM EDT THU OCT 4 2012
WE HAVE ISSUED AN UPDATE THIS EVENING TO FRESHEN UP THE FCST BASED
ON CURRENT TRENDS. THE TREND IS FOR THE RAIN TO MOVE THROUGH A
LITTLE QUICKER THAN PREVIOUSLY EXPECTED...ESPECIALLY UP NORTH WHERE THE
RAIN IS LIKELY DONE FOR THIS PORTION OF THE EVENT.
RAIN IS STILL MOVING INTO THE SRN PORTIONS OF THE AREA AS THE
FRONT PRESSES EAST. THERE HAS BEEN A COUPLE OF LIGHTNING STRIKES
OBSERVED...SO WE WILL CONTINUE THE ISOLATED MENTION OF THUNDER.
THE SRN PORTION OF THE CWFA WILL SEE RAIN HOLD OVER A LITTLE
LONGER AS ANOTHER WAVE OF RAINFALL COMING IN FROM THE SW WILL TAKE
A FEW HOURS TO PASS BY THE AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 354 PM EDT THU OCT 4 2012
THE MAIN ISSUE IS THE CONVECTIVE LINE OVER WISCONSIN HEADING
TOWARD SOUTHWEST LOWER MICHIGAN AS I WRITE THIS. BEYOND THAT THERE
IS THE ISSUE OF LAKE EFFECT RAIN SHOWERS OVER THE WEEKEND.
THE COMBINATION OF JET ASSISTED LIFT AND A DEVELOPING LOW LEVEL
JET WILL AID THE DEVELOPMENT OF A LINE OF SHOWERS THAT AT 3 PM WAS
OVER EASTERN WISCONSIN. AS THIS LINE CROSSES LAKE MICHIGAN I
EXPECT THUNDERSTORMS TO DEVELOP WITHIN THAT LINE. AIDING THAT IS
A SURGE OF HIGHER SURFACE DEW POINTS JUST AHEAD OF THE COLD FRONT.
THE 1000 TO 850 MB MOISTURE TRANSPORT VECTORS INCREASE SIGNIFICANTLY
AS THE FRONT CROSSES LAKE MICHIGAN. THE HRRR RUC IS DOING REASONABLY
WELL WITH THE CONVECTION ON THE COLD FRONT SO FAR THIS AFTERNOON.
SO...BASED ON OUR TIMING TOOL...THE TIMING IN THE HRRR RUC AND RELATED
TOOLS I EXPECT A NEARLY SOLID LINE OF SHOWERS AND ISOLATED STORMS
TO CROSS THE CWA BETWEEN 6 PM AND 11 PM THIS EVENING. I DO NOT
EXPECT SEVERE STORMS AS THE CAPES ARE NOT IMPRESSIVE BUT THERE IS
30 - 40 KNOTS OF DEEP LAYER SHEAR TO WORK WITH. THERE IS ALSO 40
TO 50 KNOTS AS CLOSE TO THE GROUND AS 5000 FT AGL AS THIS LINE
MOVES CROSS THE CWA. SO EXPECT GUSTY WINDS WITH THE SHOWERS.
ONCE THIS FEATURE MOVES EAST THE STRONG COLD ADVECTION BEHIND THE
FRONT WILL RESULT IN CONSIDERABLE SUBSIDENCE SO EXPECT CLEARING
SKIES LATER TONIGHT.
ANOTHER JET SEGMENT ROTATING THROUGH THE UPPER TROUGH WILL INDUCE
A WAVE ON THE FRONT FRIDAY INTO SATURDAY. AT THIS POINT IT SEEMS
THE RAIN FROM THAT WILL MOSTLY STAY SOUTH OF THE CWA. IT COULD
IMPACT AREAS SOUTH OF I-69 FRIDAY INTO FRIDAY EVENING EVEN SO. I
HAVE LOW CHANCE POPS FOR THAT.
THE SHORTWAVE TROUGH WITH THE DEEP COLD AIR ROTATES THROUGH THE
CWA SATURDAY. THAT WILL RESULT IN LAKE EFFECT RAIN SHOWERS. THANKS
TO A NORTH NORTHWEST WIND IN THE BOUNDARY LAYER I EXPECT MOST OF
THE SIGNIFICANT SHOWERS TO BE CLOSE TO LAKE SHORE. EVEN SO THE AIR
IS UNSTABLE ENOUGH THAT ALL AREAS SHOULD SEE SOME SHOWERS IN THE
AFTERNOON. SATURDAY NIGHT THOSE SHOWERS WILL CONTINUE NEAR THE
LAKE SHORE BUT SOME CLEARING IS POSSIBLE INLAND. COLD BE A FREEZE
EARLY SUNDAY MORNING NORTH AND EAST OF GRR. WE WILL HAVE TO WATCH
THAT FOR A POSSIBLE FREEZE WARNING.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 354 PM EDT THU OCT 4 2012
STILL EXPECTING SOME WEAK LAKE EFFECT RAIN SHOWERS INTO SUNDAY...
HOWEVER SURFACE RIDGING SHOULD BE BREAKING MUCH OF IT UP THROUGH THE
DAY. FROST POTENTIAL LOOKS RATHER GOOD INTO SUNDAY NIGHT AS SKIES
CLEAR. WE WILL HAVE TO SEE HOW MUCH MIXING REMAINS OVER THE
REGION...WHICH COULD LESSEN THE IMPACTS.
THE NEXT RAIN MAKER WILL COME IN THE FORM OF ANOTHER COLD FRONT
EXPECTED LATE TUESDAY INTO WEDNESDAY. COULD BE POCKETS OF STEADIER
RAINS AS THIS FRONT LOOKS MUCH LIKE THIS EVENING/S FRONT. HAVE LEFT
THUNDER OUT HOWEVER AS THE TIMING OF THE FROPA SHOULD BE LATE
TUESDAY NIGHT.
THE CHILLY AIR WILL SLOWLY LOSE IT/S GRIP ON THE REGION INTO EARLY
NEXT WEEK. H8 TEMPS BELOW 0C MOVE EAST OF THE AREA BY MONDAY
AFTERNOON SO A SLIGHTLY WARMING TREND IS EXPECTED WITH UPPER 50S AND
LOWER 60S FOR MONDAY AND TUESDAY. ANOTHER SHOT OF COOLER AIR IS
EXPECTED BEHIND THE TUESDAY NIGHT FRONT...HOWEVER THIS LOOKS TO BE A
QUICKER SHOT...WITH H8 TEMPS ALREADY WARMING BY THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 756 PM EDT THU OCT 4 2012
EXPECT MOSTLY VFR TONIGHT ALTHOUGH SOME SHOWERS AND ISOLATED
THUNDERSTORMS WILL BRING PATCHY MVFR AND PERHAPS SMALL AREAS OF
IFR. KEPT ALL THE TAFS VFR SINCE COVERAGE OF MVFR IS EXPECTED TO
BE VERY LIMITED. SOUTHWEST WINDS WILL GUST TO NEAR 20 KNOTS AT
TIMES THIS EVENING BEFORE DECREASING LATE TONIGHT.
&&
.MARINE...
ISSUED AT 354 PM EDT THU OCT 4 2012
I EXTENDED THE SMALL CRAFT ADVISORY INTO SATURDAY NIGHT SINCE WAVE
HEIGHTS ARE NOT EXPECTED TO SUBSIDE BELOW 4 FEET UNTIL EARLY
SUNDAY MORNING. THE EXPERIMENTAL GREAT LAKES WATER SPOUT FORECAST
SHOWS THE BEST SHOT OF WATER SPOUTS AS BEING SATURDAY AS THE DEEPER
COLD AIR MOVES IN. I PUT WATER SPOUTS IN THE NEAR SHORE DURING
THAT TIME.
THE HRRR SUGGEST POSSIBLE NEAR GALE WINDS WITH THE FRONT THIS
EVENING THAT WILL HAVE TO BE WATCHED TOO.
&&
.HYDROLOGY...
ISSUED AT 354 PM EDT THU OCT 4 2012
RAINFALL WILL BE LIMITED AT BEST OVER THE NEXT WEEK SO EVEN WITH
THE RAINS LAST NIGHT I DO NOT SEE ANY SIGNIFICANT FLOODING ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR LMZ845>849.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR LMZ844.
&&
$$
UPDATE...NJJ
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
756 PM EDT THU OCT 4 2012
.SYNOPSIS...
ISSUED AT 354 PM EDT THU OCT 4 2012
A STRONG COLD FRONT WILL CROSS THE AREA THIS EVENING WITH SHOWERS
AND SCATTERED THUNDERSTORMS. SKIES WILL CLEAR LATE TONIGHT AND IT
WILL TURN COLDER. EXPECT MOSTLY SUNNY SKIES FRIDAY WITH HIGHS ONLY
IN THE 50S. LAKE EFFECT RAIN SHOWERS ARE EXPECTED SATURDAY INTO
SUNDAY WITH HIGHS MOSTLY IN THE 4OS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 354 PM EDT THU OCT 4 2012
THE MAIN ISSUE IS THE CONVECTIVE LINE OVER WISCONSIN HEADING
TOWARD SOUTHWEST LOWER MICHIGAN AS I WRITE THIS. BEYOND THAT THERE
IS THE ISSUE OF LAKE EFFECT RAIN SHOWERS OVER THE WEEKEND.
THE COMBINATION OF JET ASSISTED LIFT AND A DEVELOPING LOW LEVEL
JET WILL AID THE DEVELOPMENT OF A LINE OF SHOWERS THAT AT 3 PM WAS
OVER EASTERN WISCONSIN. AS THIS LINE CROSSES LAKE MICHIGAN I
EXPECT THUNDERSTORMS TO DEVELOP WITHIN THAT LINE. AIDING THAT IS
A SURGE OF HIGHER SURFACE DEW POINTS JUST AHEAD OF THE COLD FRONT.
THE 1000 TO 850 MB MOISTURE TRANSPORT VECTORS INCREASE SIGNIFICANTLY
AS THE FRONT CROSSES LAKE MICHIGAN. THE HRRR RUC IS DOING REASONABLY
WELL WITH THE CONVECTION ON THE COLD FRONT SO FAR THIS AFTERNOON.
SO...BASED ON OUR TIMING TOOL...THE TIMING IN THE HRRR RUC AND RELATED
TOOLS I EXPECT A NEARLY SOLID LINE OF SHOWERS AND ISOLATED STORMS
TO CROSS THE CWA BETWEEN 6 PM AND 11 PM THIS EVENING. I DO NOT
EXPECT SEVERE STORMS AS THE CAPES ARE NOT IMPRESSIVE BUT THERE IS
30 - 40 KNOTS OF DEEP LAYER SHEAR TO WORK WITH. THERE IS ALSO 40
TO 50 KNOTS AS CLOSE TO THE GROUND AS 5000 FT AGL AS THIS LINE
MOVES CROSS THE CWA. SO EXPECT GUSTY WINDS WITH THE SHOWERS.
ONCE THIS FEATURE MOVES EAST THE STRONG COLD ADVECTION BEHIND THE
FRONT WILL RESULT IN CONSIDERABLE SUBSIDENCE SO EXPECT CLEARING
SKIES LATER TONIGHT.
ANOTHER JET SEGMENT ROTATING THROUGH THE UPPER TROUGH WILL INDUCE
A WAVE ON THE FRONT FRIDAY INTO SATURDAY. AT THIS POINT IT SEEMS
THE RAIN FROM THAT WILL MOSTLY STAY SOUTH OF THE CWA. IT COULD
IMPACT AREAS SOUTH OF I-69 FRIDAY INTO FRIDAY EVENING EVEN SO. I
HAVE LOW CHANCE POPS FOR THAT.
THE SHORTWAVE TROUGH WITH THE DEEP COLD AIR ROTATES THROUGH THE
CWA SATURDAY. THAT WILL RESULT IN LAKE EFFECT RAIN SHOWERS. THANKS
TO A NORTH NORTHWEST WIND IN THE BOUNDARY LAYER I EXPECT MOST OF
THE SIGNIFICANT SHOWERS TO BE CLOSE TO LAKE SHORE. EVEN SO THE AIR
IS UNSTABLE ENOUGH THAT ALL AREAS SHOULD SEE SOME SHOWERS IN THE
AFTERNOON. SATURDAY NIGHT THOSE SHOWERS WILL CONTINUE NEAR THE
LAKE SHORE BUT SOME CLEARING IS POSSIBLE INLAND. COLD BE A FREEZE
EARLY SUNDAY MORNING NORTH AND EAST OF GRR. WE WILL HAVE TO WATCH
THAT FOR A POSSIBLE FREEZE WARNING.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 354 PM EDT THU OCT 4 2012
STILL EXPECTING SOME WEAK LAKE EFFECT RAIN SHOWERS INTO SUNDAY...
HOWEVER SURFACE RIDGING SHOULD BE BREAKING MUCH OF IT UP THROUGH THE
DAY. FROST POTENTIAL LOOKS RATHER GOOD INTO SUNDAY NIGHT AS SKIES
CLEAR. WE WILL HAVE TO SEE HOW MUCH MIXING REMAINS OVER THE
REGION...WHICH COULD LESSEN THE IMPACTS.
THE NEXT RAIN MAKER WILL COME IN THE FORM OF ANOTHER COLD FRONT
EXPECTED LATE TUESDAY INTO WEDNESDAY. COULD BE POCKETS OF STEADIER
RAINS AS THIS FRONT LOOKS MUCH LIKE THIS EVENING/S FRONT. HAVE LEFT
THUNDER OUT HOWEVER AS THE TIMING OF THE FROPA SHOULD BE LATE
TUESDAY NIGHT.
THE CHILLY AIR WILL SLOWLY LOSE IT/S GRIP ON THE REGION INTO EARLY
NEXT WEEK. H8 TEMPS BELOW 0C MOVE EAST OF THE AREA BY MONDAY
AFTERNOON SO A SLIGHTLY WARMING TREND IS EXPECTED WITH UPPER 50S AND
LOWER 60S FOR MONDAY AND TUESDAY. ANOTHER SHOT OF COOLER AIR IS
EXPECTED BEHIND THE TUESDAY NIGHT FRONT...HOWEVER THIS LOOKS TO BE A
QUICKER SHOT...WITH H8 TEMPS ALREADY WARMING BY THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 756 PM EDT THU OCT 4 2012
EXPECT MOSTLY VFR TONIGHT ALTHOUGH SOME SHOWERS AND ISOLATED
THUNDERSTORMS WILL BRING PATCHY MVFR AND PERHAPS SMALL AREAS OF
IFR. KEPT ALL THE TAFS VFR SINCE COVERAGE OF MVFR IS EXPECTED TO
BE VERY LIMITED. SOUTHWEST WINDS WILL GUST TO NEAR 20 KNOTS AT
TIMES THIS EVENING BEFORE DECREASING LATE TONIGHT.
&&
.MARINE...
ISSUED AT 354 PM EDT THU OCT 4 2012
I EXTENDED THE SMALL CRAFT ADVISORY INTO SATURDAY NIGHT SINCE WAVE
HEIGHTS ARE NOT EXPECTED TO SUBSIDE BELOW 4 FEET UNTIL EARLY
SUNDAY MORNING. THE EXPERIMENTAL GREAT LAKES WATER SPOUT FORECAST
SHOWS THE BEST SHOT OF WATER SPOUTS AS BEING SATURDAY AS THE DEEPER
COLD AIR MOVES IN. I PUT WATER SPOUTS IN THE NEAR SHORE DURING
THAT TIME.
THE HRRR SUGGEST POSSIBLE NEAR GALE WINDS WITH THE FRONT THIS
EVENING THAT WILL HAVE TO BE WATCHED TOO.
&&
.HYDROLOGY...
ISSUED AT 354 PM EDT THU OCT 4 2012
RAINFALL WILL BE LIMITED AT BEST OVER THE NEXT WEEK SO EVEN WITH
THE RAINS LAST NIGHT I DO NOT SEE ANY SIGNIFICANT FLOODING ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR LMZ845>849.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR LMZ844.
&&
$$
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
738 PM EDT THU OCT 4 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 423 PM EDT THU OCT 4 2012
WV LOOP AND RUC ANALYSIS SHOW NEGATIVE TILTED SHORTWAVE TROUGH OVER
NORTHERN MINNESOTA THIS AFTN WITH ASSOCIATED SFC LOW IN THE VCNTY OF
KINL. COLD FRONT IS IN PROCESS OF MAKING ITS WAY ACROSS UPR
MICHIGAN...BUT MUCH COLDER AIR IS LAGGING BEHIND OVER NORTHERN
MINNESOTA. HAVE SEEN ISOLD SHRA FORM THIS AFTN WITH EVEN TSRA. MAIN
AREA WAS ON KEWEENAW BUT JUST WITHIN LAST 1 HR ANOTHER LINE OF SHRA
HAS FORMED OVER EASTERN LK SUPERIOR/FAR NORTHEAST CWA. DEEP DRYING
WRAPPING IN ON SOUTHERN EDGE OF SHORTWAVE TROUGH IS STEEPENING MID
LEVEL LAPSE RATES. MOST OF SHRA/TSRA KICKED ON WITHIN THE BETTER
LR/S AND ALSO ON LEADING EDGE OF H85 FRONTOGENESIS. OTHERWISE ONCE
PESKY FOG HELPED OUT BY MOISTURE OFF LK MICHIGAN BURNED OFF...IT HAS
BECOME NICE DAY WITH HIGHS TOPPING OUT IN THE 60S AND EVEN SOME
LOWER 70S. THAT WILL BE LAST 70 DEGREES FOR POSSIBLY THIS FALL
THOUGH AS BIG CHANGES ARE COMING IN ONCE THE LOW OVER MINNESOTA
MOVES TO NORTHERN LK SUPERIOR AND COLDER AIR PLOWS INTO THE REGION.
THROUGH FRIDAY...DO NOT EXPECT ANY BIG SNOW ACCUMS. WIDESPREAD SNOW
ON CYCLONIC SIDE OF SHORTWAVE TROUGH AND IN MOIST/CYCLONIC FLOW
BEHIND SFC LOW NEVER REALLY MAKES IT INTO CWA...INSTEAD LIFTING MORE
NORTHEAST INTO ONTARIO. INSTEAD...NORTHWEST CWA GRADUALLY GETS INTO
A REGIME WITH PLENTIFUL LOW-LEVEL MOISTURE BLO 10KFT AND WSW BLYR
WINDS TURNING MORE WESTERLY WITH TIME. SOUNDINGS INDICATE TEMPS IN
MOIST LAYER ARE WARMER THAN -8C UNTIL THE DAYTIME ON FRIDAY. UPSHOT
IS THAT INITIAL PRECIP TONIGHT INTO FRIDAY MORNING FOR NW CWA WILL
BE MAINLY LIGHT RAIN WITH PERHAPS REALLY SMALL SNOW FLAKES MIXING IN
AT TIMES LATER TONIGHT. AFTER EARLY EVENING POPS EAST...RESTRICTED
POPS FOR LAKE EFFECT/CYCLONIC FLOW MOISTURE TO KEWEENAW OVERNIGHT
TONIGHT AS REST OF AREA STAYS IN UNFAVORABLE WSW WINDS IN LOW-LEVELS.
WINDS IN BLYR LATE TONIGHT PUSH TOWARD 30 MPH SO EXPECT WINDS NW CWA
TO INCREASE LATE. SHOULD BE FAIRLY QUIET OVER REST OF CWA. SKIES MAY
EVEN CLEAR OUT SOME IN THE CNTRL AND EAST OVERNIGHT FOR A TIME.
A RATHER MISERABLE DAY IS IN STORE FOR KEWEENAW ON FRIDAY. SOUNDINGS
SHOW INCREASING DEPTH TO MOISTURE WITH MOISTURE PUSHING COLDER THAN
-10C BY AFTN SO SHOULD SEE MORE AND MORE SNOW MIX WITH RAIN THROUGH
THE DAY. BLYR TEMPS REMAIN WARM IN THE UPR 30S AND LOWER 40S...SO
EVEN IF PRECIP CHANGES TO MOSTLY SNOW DURING THE DAY /WOULD OCCUR
BASED ON WBZERO HEIGHTS FALLING WELL BLO 1000 FT AGL/ LITTLE OR NO
SNOW ACCUM SHOULD OCCUR DURING THE DAY. BEST CHANCE FOR SEEING SNOW
AS ONLY PTYPE WILL BE ON THE HIGHEST TERRAIN OF THE NW CWA. SIMILAR
TO TONIGHT...SHOULD BE PRETTY QUIET MOST OTHER AREAS ON FRIDAY
MORNING THOUGH A BIT BREEZY. BY FAR...STRONGEST WINDS WILL BE FOUND
ON THE KEWEENAW WITH FAVORED WESTERLY WINDS. MIXED LAYER WINDS
EASILY TOP OUT OVER 35 KTS AND TOP OF MIXED LAYER WINDS FROM
SOUNDINGS SUPPORT GUSTS PUSHING WELL OVER 40 KTS. WINDS ARE ALSO
STRONG ALONG LAKE SUPERIOR FROM IWD TO ONTONAGON. FAVORED WEST WIND
DIRECTION AND SUCH STRONG WINDS IN MIXED LAYER IN FACE OF STRONG
COLD AIR ADVECTION SUPPORTS FREQUENT GUSTS ON FRIDAY OVER HIGHER
TERRAIN OF KEWEENAW PENINSULA REACHING WIND ADVY LEVEL /39 KT OR 45
MPH/. WIND ADVY WAS ISSUED FOR KEWEENAW. FOR THOSE OTHER AREAS NEAR
LK SUPERIOR ADVY LEVEL WIND GUSTS SHOULD BE NOT AS FREQUENT...SO DID
NOT INCLUDE THOSE AREAS IN ADVY AT THIS TIME.
BY MID-LATE AFTN ON FRIDAY...925MB-850MB WINDS VEER MORE WNW WHICH
SHOULD BRING MORE OF CWA INTO CYCLONIC LOW-LEVEL MOIST FLOW. EXPECT
WX REGIME OVER KEWEENAW TO BEGIN TO SHIFT TOWARD HIGHER TERRAIN OF
ALL WESTERN AND POSSIBLE NCNTRL CWA BY 21Z. TEMPS MAY ALSO TRY TO
FALL OFF FOR THESE AREAS AS WELL. AGAIN...LIKE THE KEWEENAW EVEN
WITH MAINLY SNOW VERSUS RAIN...WARMER BLYR TEMPS AND MINIMAL
STRONGER LAKE EFFECT CONVECTION SHOULD PROHIBIT MUCH IN WAY OF SNOW
ACCUM. BETTER CHANCE FOR SNOW ACCUMS FOR THE CWA WILL OCCUR MORE ON
FRIDAY NIGHT WHICH IS NOW ADDRESSED IN THE LONGER TERM DISCUSSION.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 PM EDT THU OCT 4 2012
NAM SHOWS A BROAD 500 MB TROUGH ACROSS THE CENTRAL U.S. WITH A RIDGE
OFF THE PACIFIC NW AND A CLOSED LOW OFF THE CA COAST IN A REX BLOCK
PATTERN WITH A RIDGE OFF THE EAST COAST 00Z SAT. PATTERN DOES NOT
CHANGE MUCH WITH A SHORTWAVE OVER THE NORTHERN PLAINS ROTATING
AROUND THE TROUGH AND INTO THE LOWER GREAT LAKES ON SUNDAY.
BASICALLY...WILL NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.
SINCE THIS IS AN EARLY SEASON SNOW...LOT OF THE TOOLS WILL NOT WORK
USING THICKNESSES FOR DETERMINING SNOW AND PRETTY MUCH KEPT WHAT WAS
ALREADY IN THERE WHICH IS SNOW IN THE HIGHER TERRAIN AND RAIN IN THE
LOWER TERRAIN AND EASTERN CWA. DID LOWER SNOW RATIOS THOUGH AS
FEELING IS THAT THE SNOW FLAKE SIZE WILL BE SMALL AND LOWER THAN A
10 TO 1 RATIO WILL WORK. THIS STILL GIVES ME 1-3 INCHES IN THE
HIGHER TERRAIN FOR FRI NIGHT THROUGH SAT EVENING. IT WILL BE COLD
ENOUGH FOR LAKE EFFECT PCPN AND LOWERED THE LAKE TEMPERATURES TO 10C
TO 12C FOR FRI NIGHT AND SAT AS THINKING IS THE LAKE WILL START TO
GET TURNED OVER AND WATER TEMPERATURES WILL COOL OFF FROM 12C TO 15C
THAT IT IS NOW. 850 MB TEMPERATURES COOL TO AROUND -6C BY 12Z SAT
AND THAT IS ENOUGH LAKE EFFECT DELTA-T FOR LAKE EFFECT. BY
SUNDAY...WINDS SWITCH TO THE SW AND WITH WARM AIR ADVECTION COMING
IN...THIS WILL PUSH THE LAKE EFFECT PCPN OFFSHORE OF THE U.P.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH ACROSS
THE CENTRAL AND EASTERN U.S. WITH A RIDGE OFF THE PACIFIC NW AND A
CLOSED LOW OFF THE CA COAST IN A REX BLOCK PATTERN 12Z MONDAY. THERE
IS A SHORTWAVE ACROSS SOUTH CENTRAL CANADA THAT IS POISED TO DROP
INTO THE UPPER GREAT LAKES WITH AN ALBERTA CLIPPER SYSTEM THAT MOVES
THROUGH MON NIGHT INTO TUE. THE TROUGH OVER THE CENTRAL AND EASTERN
U.S. STAYS ANCHORED OVER THE UPPER GREAT LAKES INTO WED. ANOTHER
CLIPPER TYPE SYSTEM LOOKS TO AFFECT THE AREA ON THU. IT LOOKS TO
STAY COLDER THAN NORMAL THROUGH THE EXTENDED PERIOD WITH ACTIVE
WEATHER. KEPT MIXTURE OF RAIN AND SNOW IN FOR LATE TUE NIGHT INTO
WED MORNING WITH NEXT COLD AIR WAVE THAT COMES THROUGH. DID NOT MAKE
TOO MANY CHANGES TO THE GOING FORECAST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 737 PM EDT THU OCT 4 2012
UPPER MI WILL BE UNDER THE CIRCULATION OF A LOW PRES SYSTEM MOVING
ACROSS NRN ONTARIO TONIGHT AND FRI. INITIALLY...CONDITIONS WILL BE
VFR AT KIWD/KCMX/KSAW...BUT AS COLDER AIR INCREASES OVERLAKE
INSTABILITY AND MOISTURE WRAPS AROUND LOW INTO THE AREA...EXPECT
CIGS TO LOWER TO MVFR THIS EVENING AT KCMX AND LATE TONIGHT AT KIWD.
THE COLDER AIR WILL ALSO LEAD TO LAKE ENHANCED RAIN/SNOW/IFR
CONDITIONS DEVELOPING AT KCMX LATER TONIGHT INTO FRI MORNING AND
THEN CONTINUING THRU FRI. WINDS SHOULD VEER ENOUGH TO BRING LAKE
EFFECT PCPN INTO KIWD FRI AFTN. AT KSAW...WSW/DOWNSLOPING WINDS
THRU THE PERIOD SHOULD RESULT IN VFR CONDITIONS PREVAILING WITH NO
PCPN. WITH A TIGHT PRES GRADIENT...WINDS WILL BE STRONG WITH GUSTS
AOA 30KT. STRONGEST WINDS...GUSTING TO 40KT OR SO FRI...WILL BE AT
KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT THU OCT 4 2012
AN INTENSIFYING LOW PRESSURE SYSTEM WILL MOVE NORTH-NORTHEAST FROM
CENTRAL MINNESOTA TO THE U.S./CANADIAN BORDER BY THIS
AFTERNOON...BEFORE BEING LOCATED JUST NORTH NORTHWEST OF LAKE
SUPERIOR BY LATE TONIGHT. THIS WILL LEAD TO INCREASING SOUTHWESTERLY
WINDS ACROSS THE LAKE THIS AFTERNOON WITH GALE FORCE GUSTS OF
35-45KTS EXPECTED OVER MAINLY WRN LAKE SUPERIOR THIS
AFTERNOON/EVENING...INCREASING TO 45KTS TONIGHT INTO EARLY FRIDAY.
THE LOW WILL SHIFT NORTHEAST ON FRIDAY...BUT WILL KEEP A SFC TROUGH
OVER LAKE SUPERIOR THROUGH FRIDAY NIGHT. AS THIS SFC TROUGH SLOWLY
SLIDES SE ACROSS LAKE SUPERIOR...EXPECT WINDS TO SHIFT TO THE
NORTHWEST AND GUSTS UP TO 35KTS AT TIMES. A HIGH PRESSURE RIDGE WILL
BUILD OVER THE UPPER GREAT LAKES REGION ON SATURDAY AND
SUNDAY...LOWERING WINDS BELOW 25KTS. WINDS COME UP TO 30 KNOTS FOR
MON NIGHT AND TUE WITH NEXT CLIPPER TYPE SYSTEM BRINGING IN SOME
COLDER AIR. GETS REAL CLOSE TO A GALE THEN WITH A TIGHTER PRESSURE
GRADIENT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY FROM 7 AM TO 6 PM EDT FRIDAY FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING FROM 6 AM FRIDAY TO 10 AM EDT SATURDAY FOR LSZ267.
GALE WARNING FROM 11 PM THIS EVENING TO 10 AM EDT SATURDAY FOR
LSZ265-266.
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ FRIDAY FOR LSZ162-240>245.
GALE WARNING UNTIL 10 AM EDT SATURDAY FOR LSZ264.
GALE WARNING UNTIL 6 AM EDT SATURDAY FOR LSZ263.
GALE WARNING FROM 6 AM TO 8 PM EDT FRIDAY FOR LSZ248.
GALE WARNING FROM 11 PM THIS EVENING TO 8 PM EDT FRIDAY FOR
LSZ246-247.
LAKE MICHIGAN...
GALE WARNING FROM MIDNIGHT TONIGHT TO 2 PM EDT FRIDAY FOR LMZ221-
248-250.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...ROLFSON
MARINE...07
AREA FORECAST DISCUSSION
NWS JACKSON MS
949 AM CDT WED OCT 3 2012
.UPDATE...POPS WERE INCREASED OVER SOUTHERN AND EASTERN AREAS FOR
THIS AFTERNOON IN LIEU OF PROGGED 500-800 J/KG ML CAPE UNDER DECENT
LAPSE RATES AS A WEAK LOW-LVL SOUTHERN FETCH MOISTURE TOUNGE FEEDS
INTO THE AREA. IT COULD BE CONCEIVEABLE THAT ONE OR TWO OF THE ISO
TSTORMS THIS AFTN COULD BE STRONG WITH SUCH COOL TEMPS ALOFT AND
DECENT BL HEATING. STRONG STORM RISKS WILL BE GUSTY WINDS TO 40 MPH
AND SOME SMALL HAIL. WILL PLACE STRONG STORM WORDING IN HWO FOR THIS
UPDATE.
ACTIVITY WILL WANE NEAR SUNSET AS INSTABILITY DECREASES AND VORT MAX
SHIFTS EAST. MINOR TWEAKS TO HOURLY WX ELEMENTS TO MATCH LATEST
TRENDS WERE ALSO MADE. UPDATED PRODUCTS ARE OUT AND AN UPDATED
AVIATON DISCUSSION CAN BE FOUND DIRECTLY BELOW. /ALLEN/
&&
.AVIATION...A ROBUST UPPER LOW MOVING OVER THE REGION TODAY SHOULD
RESULT IN SCATTERED CU DEVELOPMENT AS THE DAY PROGRESSES...WITH
BASES GENERALLY FROM 3 TO 6 KFT. SOME ISOLATED SHOWER AND
THUNDERSTORM DEVELOPMENT WILL ALSO BE POSSIBLE IN THE
AFTERNOON...BUT MAINLY ALONG AND SOUTHEAST OF THE NATCHEZ TRACE
CORRIDOR. OTHERWISE...WINDS WILL MAINLY BE FROM THE SOUTH AND NOT
TOO STRONG (LESS THAN 15 MPH). SHOWERS SHOULD END THIS EVENING WITH
A CHANCE OF PATCHY FOG AND/OR LOW CLOUD DEVELOPMENT LATE TONIGHT
INTO EARLY THURSDAY MORNING. DUE TO THE LATTER POTENTIAL MANY SITES
CAN EXPECT A DECENT POSSIBILITY OF TEMPORARY MVFR FLIGHT CATS
BETWEEN 5 AM AND 9 AM TOMORROW MORNING. /BB/
&&
.PREV DISCUSSION... /ISSUED 417 AM CDT WED OCT 3 2012/
SHORT TERM...IR IMAGERY THIS MORNING CLEARLY DEPICTS THE CLOSED
UPPER LOW OVER NORTHERN LA...WITH AREA RADARS SHOWING A CLUSTER OF
SHOWERS AND THUNDERSTORMS OVER CATAHOULA AND CONCORDIA PARISH.
SURFACE ANALYSIS SHOWS THESE STORMS DEVELOPING ALONG A WEAK SURFACE
BOUNDARY DRAPED ROUGHLY FROM MOBILE TO JUST NORTH OF ALEXANDRIA. THE
LATEST HRRR RUN VERIFIED THIS CONVECTION ALMOST PERFECTLY...AND
SUGGESTS THESE STORMS WILL BEGIN TO DIMINISH BY SUNRISE AS THEY
DRIFT NORTH. THE QUESTION THEN BECOMES...WHAT KIND OF CHANCE DO WE
HAVE FOR SEEING ADDITIONAL SHOWERS AND STORMS LATER THIS AFTERNOON?
NWP GUIDANCE INDICATES THE UPPER LOW WILL BEGIN TO OPEN AND LIFT
NORTHWARD TODAY AS THE UPPER JET STRENGTHENS OVER AL...WITH THE
WEAKENING S/WV SHIFTING EAST ACROSS THE CWA THROUGH THE DAY. FORCING
FOR ASCENT IN ADVANCE OF THE WAVE WILL BE RATHER POTENT ACROSS
SOUTHERN/SOUTHEASTERN AREAS TODAY...AND COUPLED WITH /1.THE
AFOREMENTIONED BOUNDARY LIFTING NORTHWARD INTO SOUTHERN PORTIONS OF
THE CWA BY LATE MORNING AND /2.SURFACE HEATING RAISING SBCAPE VALUES
ACROSS SOUTHERN/SOUTHEASTERN AREAS INTO THE 600-800J/KG RANGE/ I
THINK THE INGREDIENTS WILL BE SUFFICIENT FOR AT LAST ISOLATED
CONVECTIVE DEVELOPMENT. BEST GUESS RIGHT NOW IS FOR THIS ACTIVITY TO
START ACROSS SOUTHERN ZONES AROUND MID DAY...DRIFTING NORTHWARD/
NORTHEASTWARD WITH ADDITIONAL ISOLATED DEVELOPMENT FURTHER NORTH AND
EAST AS THE DAY WEARS ON. A COMBINATION OF SETTING SUN AND THE BEST
LIFT PUSHING EAST SHOULD BRING THIS ALL TO AN END BY EARLY EVENING.
BASED ON CONVECTIVE PARAMETERS OFFERED BY THE MORE REASONABLE
LOOKING 00Z GFS/ECMWF IT DOESN`T APPEAR SEVERE STORMS WILL BE A HUGE
CONCERN...BUT GIVEN RATHER COLD TEMPS ALOFT I COULD SEE ONE OR TWO
BECOMING STRONG ENOUGH TO POSE A 40 MPH WIND GUST AND SMALL HAIL
RISK.
ONCE THIS ALL CLEARS OUT THE FORECAST BECOMES RATHER UNEVENTFUL AS A
ZONAL UPPER FLOW PATTERN TAKES SHAPE ACROSS THE SOUTHEASTERN STATES
AND SURFACE RIDGING NOSES IN FROM THE EAST. SKIES SHOULD REMAIN
MOSTLY CLEAR THROUGH THE END OF THE WEEK ACCOMPANIED BY DAYTIME
TEMPS CLIMBING BACK ABOVE NORMAL BY TOMORROW WITH HIGHS IN THE MID
80S. LOWS TONIGHT AND TOMORROW NIGHT WILL COME IN MID-UPPER 50S FOR
MOST AREAS. /BK/
LONG TERM...THE NEXT SURFACE BOUNDARY BEGINS TO MOVE INTO NRN MS
FRIDAY NIGHT. THE GFS IS ONCE AGAIN SHOWING A FASTER SWD PROGRESSION
THAN THE EURO...THE LATEST EURO COMING IN SLIGHTLY SLOWER THAN IT
WAS YESTERDAY. THE EURO MOVES THE COLD FRONT JUST INTO THE NWRN
CORNER OF THE FORECAST AREA BY EARLY SATURDAY AFTERNOON WHILE THE
GFS BRINGS IT INTO THE VICINITY OF THE NATCHEZ TRACE. SLOWER
PROGRESSION NOTWITHSTANDING...MODELS ARE IN AGREEMENT THAT THE FRONT
WILL USHER A COLD AIR MASS INTO THE FORECAST AREA WITH SINGLE DIGIT
850 MB TEMPS ACROSS MOST OF THE AREA FOR SUNDAY THROUGH MONDAY.
MODERATION OF TEMPERATURES BEGINS TUESDAY WHEN THE SURFACE HIGH
CENTER LIFTS TO THE NE OF THE AREA AND 850 MB W/SWLY FLOW RETURNS.
THE AIR MASS WILL REMAIN DRY AHEAD OF THE BOUNDARY. LITTLE IN THE
WAY OF LOW LEVEL CONVERGENCE IS EXPECTED ALONG THE FRONT AND LOW
LEVEL/850 MB RIDGING WILL HOLD STEADY AS IT APPROACHES. BETTER UPPER
LEVEL FORCING IS EXPECTED TO THE REAR OF THE FRONT IN RESPONSE TO A
BROAD UPPER TROUGH THAT WILL DIG INTO THE ERN U.S...A HEALTHY
SHORTWAVE PIVOTING INTO THE MID/UPPER MS VALLEY SATURDAY NIGHT.
DUE TO THE SLOWER EURO AND THE SLOWER ADVANCE OF THE GFS QPF
FIELD...MEX POPS HAVE BEEN CUT SLIGHTLY FOR FRIDAY NIGHT. HAVE KEPT
THE VERY LOW RAIN CHANCES PAINTED FOR SUNDAY/SUNDAY NIGHT AS A
SECOND UPPER WAVE DIGS INTO THE LONG WAVE TROUGH. HAVE ALSO
INCREASED SATURDAY HIGHS A FEW DEGREES OVER MEX NUMBERS IN LIGHT OF
THE POTENTIAL FOR SLOWER FRONTAL PROGRESSION BUT NOT AS MUCH AS THE
EURO WHICH IS UP TO TEN DEGREES WARMER IN DELTA REGIONS THAN THE MEX
FOR SATURDAY AFTERNOON. ALSO DECREASED SUNDAY HIGHS A FEW DEGREES IN
THE NORTH TO KEEP THOSE AREAS SLIGHTLY COOLER THAN AREAS FARTHER
SOUTH AND SLOWED THE WARM UP THROUGH MONDAY AND TUESDAY SLIGHTLY.
&&
.AVIATION...
CLR SKIES/LGT WINDS ALLOWING MVFR VSBY IN FOG TO DEVELOP
AT SEVERAL SITES THIS MORNING...AND WOULD NOT BE SURPRISED TO SEE
IFR VSBY OFF AND ON THROUGH ~13Z BEFORE THINGS TREND VFR. VFR CONDS
WILL THEN PREVAIL THRU THE DAY AND INTO THE EVENING BEFORE A RETURN
OF MVFR VSBY BECOMES PSBL AT MOST SITES 07-13Z TOMORROW. THERE`S A
CHANCE ISOLD SHWRS/TSRA WILL DEVELOP ACROSS SRN/SERN MS THIS AFTN AS
AN UPPER DISTURBANCE PASSES. CALM SFC WINDS THIS MORNING BECMG SRLY
5-8KTS THIS AFTN. /BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 81 56 85 56 / 19 3 2 7
MERIDIAN 82 52 85 51 / 21 5 2 7
VICKSBURG 81 55 86 55 / 15 3 2 7
HATTIESBURG 84 57 87 57 / 23 8 3 4
NATCHEZ 81 56 85 57 / 20 3 2 6
GREENVILLE 80 57 86 58 / 5 3 2 7
GREENWOOD 80 55 86 56 / 17 3 2 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS JACKSON MS
417 AM CDT WED OCT 3 2012
.SHORT TERM...IR IMAGERY THIS MORNING CLEARLY DEPICTS THE CLOSED
UPPER LOW OVER NORTHERN LA...WITH AREA RADARS SHOWING A CLUSTER OF
SHOWERS AND THUNDERSTORMS OVER CATAHOULA AND CONCORDIA PARISH.
SURFACE ANALYSIS SHOWS THESE STORMS DEVELOPING ALONG A WEAK SURFACE
BOUNDARY DRAPED ROUGHLY FROM MOBILE TO JUST NORTH OF ALEXANDRIA. THE
LATEST HRRR RUN VERIFIED THIS CONVECTION ALMOST PERFECTLY...AND
SUGGESTS THESE STORMS WILL BEGIN TO DIMINISH BY SUNRISE AS THEY
DRIFT NORTH. THE QUESTION THEN BECOMES...WHAT KIND OF CHANCE DO WE
HAVE FOR SEEING ADDITIONAL SHOWERS AND STORMS LATER THIS AFTERNOON?
NWP GUIDANCE INDICATES THE UPPER LOW WILL BEGIN TO OPEN AND LIFT
NORTHWARD TODAY AS THE UPPER JET STRENGTHENS OVER AL...WITH THE
WEAKENING S/WV SHIFTING EAST ACROSS THE CWA THROUGH THE DAY. FORCING
FOR ASCENT IN ADVANCE OF THE WAVE WILL BE RATHER POTENT ACROSS
SOUTHERN/SOUTHEASTERN AREAS TODAY...AND COUPLED WITH /1.THE
AFOREMENTIONED BOUNDARY LIFTING NORTHWARD INTO SOUTHERN PORTIONS OF
THE CWA BY LATE MORNING AND /2.SURFACE HEATING RAISING SBCAPE VALUES
ACROSS SOUTHERN/SOUTHEASTERN AREAS INTO THE 600-800J/KG RANGE/ I
THINK THE INGREDIENTS WILL BE SUFFICIENT FOR AT LAST ISOLATED
CONVECTIVE DEVELOPMENT. BEST GUESS RIGHT NOW IS FOR THIS ACTIVITY TO
START ACROSS SOUTHERN ZONES AROUND MID DAY...DRIFTING NORTHWARD/
NORTHEASTWARD WITH ADDITIONAL ISOLATED DEVELOPMENT FURTHER NORTH AND
EAST AS THE DAY WEARS ON. A COMBINATION OF SETTING SUN AND THE BEST
LIFT PUSHING EAST SHOULD BRING THIS ALL TO AN END BY EARLY EVENING.
BASED ON CONVECTIVE PARAMETERS OFFERED BY THE MORE REASONABLE
LOOKING 00Z GFS/ECMWF IT DOESN`T APPEAR SEVERE STORMS WILL BE A HUGE
CONCERN...BUT GIVEN RATHER COLD TEMPS ALOFT I COULD SEE ONE OR TWO
BECOMING STRONG ENOUGH TO POSE A 40 MPH WIND GUST AND SMALL HAIL
RISK.
ONCE THIS ALL CLEARS OUT THE FORECAST BECOMES RATHER UNEVENTFUL AS A
ZONAL UPPER FLOW PATTERN TAKES SHAPE ACROSS THE SOUTHEASTERN STATES
AND SURFACE RIDGING NOSES IN FROM THE EAST. SKIES SHOULD REMAIN
MOSTLY CLEAR THROUGH THE END OF THE WEEK ACCOMPANIED BY DAYTIME
TEMPS CLIMBING BACK ABOVE NORMAL BY TOMORROW WITH HIGHS IN THE MID
80S. LOWS TONIGHT AND TOMORROW NIGHT WILL COME IN MID-UPPER 50S FOR
MOST AREAS. /BK/
.LONG TERM...THE NEXT SURFACE BOUNDARY BEGINS TO MOVE INTO NRN MS
FRIDAY NIGHT. THE GFS IS ONCE AGAIN SHOWING A FASTER SWD PROGRESSION
THAN THE EURO...THE LATEST EURO COMING IN SLIGHTLY SLOWER THAN IT
WAS YESTERDAY. THE EURO MOVES THE COLD FRONT JUST INTO THE NWRN
CORNER OF THE FORECAST AREA BY EARLY SATURDAY AFTERNOON WHILE THE
GFS BRINGS IT INTO THE VICINITY OF THE NATCHEZ TRACE. SLOWER
PROGRESSION NOTWITHSTANDING...MODELS ARE IN AGREEMENT THAT THE FRONT
WILL USHER A COLD AIR MASS INTO THE FORECAST AREA WITH SINGLE DIGIT
850 MB TEMPS ACROSS MOST OF THE AREA FOR SUNDAY THROUGH MONDAY.
MODERATION OF TEMPERATURES BEGINS TUESDAY WHEN THE SURFACE HIGH
CENTER LIFTS TO THE NE OF THE AREA AND 850 MB W/SWLY FLOW RETURNS.
THE AIR MASS WILL REMAIN DRY AHEAD OF THE BOUNDARY. LITTLE IN THE
WAY OF LOW LEVEL CONVERGENCE IS EXPECTED ALONG THE FRONT AND LOW
LEVEL/850 MB RIDGING WILL HOLD STEADY AS IT APPROACHES. BETTER UPPER
LEVEL FORCING IS EXPECTED TO THE REAR OF THE FRONT IN RESPONSE TO A
BROAD UPPER TROUGH THAT WILL DIG INTO THE ERN U.S...A HEALTHY
SHORTWAVE PIVOTING INTO THE MID/UPPER MS VALLEY SATURDAY NIGHT.
DUE TO THE SLOWER EURO AND THE SLOWER ADVANCE OF THE GFS QPF
FIELD...MEX POPS HAVE BEEN CUT SLIGHTLY FOR FRIDAY NIGHT. HAVE KEPT
THE VERY LOW RAIN CHANCES PAINTED FOR SUNDAY/SUNDAY NIGHT AS A
SECOND UPPER WAVE DIGS INTO THE LONG WAVE TROUGH. HAVE ALSO
INCREASED SATURDAY HIGHS A FEW DEGREES OVER MEX NUMBERS IN LIGHT OF
THE POTENTIAL FOR SLOWER FRONTAL PROGRESSION BUT NOT AS MUCH AS THE
EURO WHICH IS UP TO TEN DEGREES WARMER IN DELTA REGIONS THAN THE MEX
FOR SATURDAY AFTERNOON. ALSO DECREASED SUNDAY HIGHS A FEW DEGREES IN
THE NORTH TO KEEP THOSE AREAS SLIGHTLY COOLER THAN AREAS FARTHER
SOUTH AND SLOWED THE WARM UP THROUGH MONDAY AND TUESDAY SLIGHTLY.
&&
.AVIATION...CLR SKIES/LGT WINDS ALLOWING MVFR VSBY IN FOG TO DEVELOP
AT SEVERAL SITES THIS MORNING...AND WOULD NOT BE SURPRISED TO SEE
IFR VSBY OFF AND ON THROUGH ~13Z BEFORE THINGS TREND VFR. VFR CONDS
WILL THEN PREVAIL THRU THE DAY AND INTO THE EVENING BEFORE A RETURN
OF MVFR VSBY BECOMES PSBL AT MOST SITES 07-13Z TOMORROW. THERE`S A
CHANCE ISOLD SHWRS/TSRA WILL DEVELOP ACROSS SRN/SERN MS THIS AFTN AS
AN UPPER DISTURBANCE PASSES. CALM SFC WINDS THIS MORNING BECMG SRLY
5-8KTS THIS AFTN. /BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 81 56 85 56 / 13 3 2 7
MERIDIAN 82 52 85 51 / 14 5 2 7
VICKSBURG 81 55 86 55 / 11 3 2 7
HATTIESBURG 84 57 87 57 / 19 8 3 4
NATCHEZ 81 56 85 57 / 15 3 2 6
GREENVILLE 80 57 86 58 / 5 3 2 7
GREENWOOD 80 55 86 56 / 7 3 2 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BK/03
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1258 PM CDT WED OCT 3 2012
.AVIATION...18Z KGRI TAF
REST OF THIS AFTERNOON: VFR CLEAR. BREEZY S WINDS WILL GUST UP TO
30 KTS. ALL ELEMENTS HIGH CONFIDENCE.
TONIGHT: COLD FRONTAL PASSAGE NEAR 03Z. WINDS WILL SLACKEN
IMMEDIATELY AHEAD OF THE FRONT...THEN AN ABRUPT WINDSHIFT TO NNW.
WINDS WILL GUST TO 32 KTS...WITH POTENTIAL FOR AN ISOLATED G35.
WHILE VFR MID-LEVEL CIGS WILL MOVE IN AFTER FROPA...WE/RE NOTING
MVFR CIGS UPSTREAM OVER WY SEEPING INTO SD. THIS PROBABLY MAKES
IT INTO GRI TNGT...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN
18Z TAF. WHILE MODEL RH FIELDS SUPPORT THIS...OTHER GUIDANCE IS
NOT THERE YET. BOTTOM LINE...TAF MAY NEED MVFR/IFR CIGS. FOR NOW
MAINTAINED MENTION OF SCT010. CONFIDENCE IS HIGH ON WINDS/VSBYS
AND MID-LEVEL CIGS...BUT BELOW AVERAGE OF DEVELOPMENT/TIMING OF
LOW CIGS.
THU THROUGH 18Z: CURRENT EXPECTATION IS FOR CLEARING/VFR TO
DEVELOP. WINDS WILL CONTINUE TO GUST TO NEAR 30 KTS...BUT BEGIN TO
DECREASE AFTER 15Z. CONFIDENCE AVERAGE ALL ELEMENTS.
&&
.PREV DISCUSSION... /ISSUED 1115 AM CDT WED OCT 3 2012/
..ONE DAY OF SUNNY/BREEZY/VERY WARM CONDITIONS TODAY WILL BE
REPLACED BY DRASTIC 25-30F DOWNTURN IN TEMPS TOMORROW...
RED FLAG WARNING ISSUED AT 439 AM CONTINUES AS POSTED. IT/S
MARGINAL BASED ON EXACT CRITERIA...BUT CONDITIONS WILL CERTAINLY
BE THREATENING. BEST CHANCE OF VERIFYING /3 CONSECUTIVE HRS/ WILL
BE W OF A LINE FROM ODX-HDE...WHERE DWPTS IN THE MID 30S WILL EDGE
IN WITH EWD PROGRESSION OF LEE TROF IMMEDIATELY AHEAD OF THE
FRONT.
FRONT IS CURRENTLY LOCATED OVER CENTRAL WY INTO WRN SD. PRESENT
INDICATIONS VIA THE 12Z NAM/15Z RAP ARE THAT THE FRONT WILL ENTER
DAWSON/VALLEY COUNTIES IN THE 7-8 PM TIME-FRAME...BE TO GRI BY 10
PM AND SE OF THE FCST AREA BY 2 AM.
WITH LONGWAVE TROF OVER THE ERN USA...THE WARM SECTOR IS VERY DRY.
MOST OF THE CLOUD COVER IS POST-FRONTAL. PCPN CHANCES AHEAD OF THE
FRONT WILL BE NIL.
TEMPS: 12Z LBF SOUNDING OFFERS A MAX TEMP OF 89F. ADJUSTED TEMPS
SLIGHTLY USING BIAS CORRECTED CONSENSUS MOS. THIS RAISED TEMPS
A COUPLE DEG W OF HWY 281 AND LOWERED THEM E OF HWY 281. ALSO
ADJUSTED TEMP CURVES TO ACCOUNT FOR MORE RAPID UPGLIDE THRU 18Z.
WINDS: MEAN SPEEDS IN THE MIXED LAYER WILL AVERAGE 25 KTS WITH A
MAX OF 31 KTS VIA BUFKIT. SO WHILE SFC WINDS WILL AVERAGE 15-25
MPH WITH G30 ...ONE-TIME PEAK GUSTS WILL PROBABLY REACH 34-37 MPH.
WINDS FROM 4 AM GID FCST ISSUANCE LOOK GOOD.
UPDATED FCST HAS ALREADY POSTED TO THE WEB. UPDATED ZFP/AFM/PFM
WILL POST SHORTLY.
PREV DISCUSSION... /ISSUED 417 AM CDT WED OCT 3 2012/
SHORT TERM...TODAY THROUGH 12Z SATURDAY. MAIN FORECAST CHALLENGE
CONTINUES TO BE THE APPROACHING COLD FRONT AND THE ASSOCIATED
WEATHER RELATED PHENOMENA. THE WIND FIELD COUPLED WITH LOW
RELATIVE HUMIDITY VALUES AHEAD OF THE COLD FRONT WILL PRESENT FIRE
WEATHER CONCERNS FOR TODAY. GOING WITH A RED FLAG WARNING FOR OUR
NEBRASKA COUNTIES THIS AFTERNOON.
TEMPERATURES AHEAD OF THE COLD FRONT WILL GET INTO THE MID 80S.
SOUTHERLY WIND SPEEDS AHEAD OF THE COLD FRONT WILL RANGE FROM 15 TO
20 MPH WITH GUSTS CLOSER TO 30 MPH. DEWPOINTS BEING IN THE MID TO
UPPER 30S AND LOWER 40S THIS AFTERNOON WILL PRODUCE RELATIVE
HUMIDITY VALUES IN THE UPPER TEENS AND LOWER 20S FOR A MAJORITY OF
THE CWA. GIVEN THESE CONDITIONS...A RED FLAG WAS WARRANTED THIS
AFTERNOON AND ONGOING THROUGH THE EARLY EVENING HOURS. THE TIMING
OF THE COLD FRONT COULD BE A KEY ISSUE TODAY WITH REGARDS TO FIRE
WEATHER CONCERNS. IF THE BOUNDARY SPEEDS UP ANYMORE THAN WHAT IS
FORECAST NOW...THESE CONDITIONS MIGHT NOT BE MET AS RELATIVE
HUMIDITY VALUES WILL QUICKLY BEGIN TO RISE AS THE FRONT PASSES.
THIS IS NOT A SLAM-DUNK EVENT...MAINLY BECAUSE THE TIMING OF THE
FRONT HAS NOT BEEN VERY CONSISTENT OVER THE LAST SEVERAL DAYS SO
CONFIDENCE IS LEANING TOWARDS MARGINAL. WITH THE BOUNDARY BEING
LESS THAN 24 HOURS FROM APPROACHING...THE GUIDANCE SHOULD HAVE A
DECENT GRIP ON THE SITUATION SO WENT WITH THE WARNING.
AS A RESULT OF LACKING MOISTURE CURRENTLY PROGGED TO BE IN THE
ATMOSPHERE TODAY...PRECIPITATION CHANCES BEHIND THE FRONT HAVE
DIMINISHED SIGNIFICANTLY ACROSS THE CWA FROM PREVIOUS FORECAST. THIS
ANALYSIS FALLS IN LINE WITH THE CRITERIA FOR FIRE WEATHER TODAY AS
FORECAST SOUNDINGS INDICATE A RATHER DRY ATMOSPHERE WITH AN
INVERTED-V PROFILE...WHERE THE LOWER LEVELS ARE ESPECIALLY DRY.
FURTHERMORE...CROSS SECTIONS OVER TIME SHOW VERY LITTLE MOISTURE IN
THE ATMOSPHERE DURING THE PASSAGE OF THE FRONT. PRECIPITATION
CHANCES ARE BEST BETWEEN 06Z AND 12Z WHERE MOISTURE BECOMES
EVIDENT...ALBEIT THESE CHANCES ARE STILL NOT VERY GOOD AS SLIGHT
CHANCES ARE CURRENTLY FORECAST. A BREAK IN PRECIPITATION CHANCES
OCCURS THURSDAY THROUGH THURSDAY NIGHT.
FRIDAY/FRIDAY NIGHT IS VERY INCONSISTENT BETWEEN THE MODELS AS FAR
AS PRECIP CHANCES GO. WITH THAT SAID...A CONVERGENCE ZONE IN THE
LOWER LEVELS WITH PLENTY OF MOISTURE IS FORECAST TO SET UP OVER THE
OUTLOOK AREA FRIDAY. TIMING AND COVERAGE WILL BE THE MAIN CHALLENGE
AS MODELS VARY IN OUTPUT. CONFIDENCE IS LOW FOR PRECIPITATION AT
THIS TIME AND SLIGHT CHANCES WILL BE FORECAST.
TEMPERATURES ON SATURDAY MORNING ARE GOING TO BE NEAR THE LOWER
30S FOR A MAJORITY OF THE CWA...HOWEVER...PRECIPITATION CHANCES
AND CLOUD COVER COULD PRODUCE SOME WARMER TEMPERATURES OVERNIGHT
THAN WHAT IS CURRENTLY FORECAST. OVERALL...ITS GOING TO BE A
RATHER CHILLY NIGHT ACROSS THE OUTLOOK AREA.
LONG TERM...SATURDAY THROUGH TUESDAY. THE BIG STORY WILL CENTER
AROUND THE COLD TEMPERATURES...WHICH WILL BE THE COLDEST WEATHER WE
HAVE SEEN SINCE EARLY MARCH. LOW TEMPERATURES MAY FALL BELOW
FREEZING AS EARLY AS SATURDAY MORNING...BUT ARE EVEN MORE LIKELY TO
FALL BELOW FREEZING BY SATURDAY NIGHT INTO SUNDAY MORNING. OUR
CURRENT FORECAST IS CALLING FOR LOWS SATURDAY NIGHT/SUNDAY MORNING
TO RANGE FROM THE MID 20S AROUND ORD...TO THE UPPER 20S IN THE TRI
CITIES...TO AROUND 30 IN NORTHERN KANSAS. THIS WILL MARK THE END OF
THE GROWING SEASON...WHICH FOR HASTINGS AND MOST LOCATIONS SOUTH OF
HASTINGS INTO NORTHERN KANSAS WILL BE THE LONGEST GROWING SEASON ON
RECORD AT AROUND 210 CONSECUTIVE DAYS WITH LOW TEMPERATURES ABOVE
32F. THE LAST TIME HASTINGS WAS 32F OR BELOW WAS BACK ON MARCH 9TH.
GRAND ISLAND HAD THEIR LAST FREEZE A LITTLE LATER ON APRIL 11TH AND
THUS THE GRAND ISLAND GROWING SEASON IS NOT EXPECTED TO BE A
RECORD...BUT IT SHOULD STILL BE AROUND THE 15TH OR 16TH LONGEST
GROWING SEASON ON RECORD.
IN ADDITION TO THE COLD OVERNIGHT LOWS...HIGH TEMPERATURES SATURDAY
ARE ONLY FORECAST TO BE AROUND 50 DEGREES WITH COOL AND DRY HIGH
PRESSURE OVERHEAD. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
TUESDAY BUT EXPECT HIGHS WILL GRADUALLY MODERATE INTO THE MID AND
UPPER 50S ON SUNDAY AND THEN 60S BY MONDAY AND TUESDAY. NORMAL HIGH
TEMPERATURES WOULD BE RIGHT AROUND 70F. DRY WEATHER IS EXPECTED TO
PERSIST THROUGH THE EXTENDED PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR NEZ039>041-
046>049-060>064-072>077-082>087.
KS...NONE.
&&
$$
AVIATION: HALBLAUB
UPDATE: HALBLAUB
SHORT TERM: GUERRERO
LONG TERM: WESELY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1115 AM CDT WED OCT 3 2012
.UPDATE...
...ONE DAY OF SUNNY/BREEZY/VERY WARM CONDITIONS TODAY WILL BE
REPLACED BY DRASTIC 25-30F DOWNTURN IN TEMPS TOMORROW...
RED FLAG WARNING ISSUED AT 439 AM CONTINUES AS POSTED. IT/S
MARGINAL BASED ON EXACT CRITERIA...BUT CONDITIONS WILL CERTAINLY
BE THREATENING. BEST CHANCE OF VERIFYING /3 CONSECUTIVE HRS/ WILL
BE W OF A LINE FROM ODX-HDE...WHERE DWPTS IN THE MID 30S WILL EDGE
IN WITH EWD PROGRESSION OF LEE TROF IMMEDIATELY AHEAD OF THE
FRONT.
FRONT IS CURRENTLY LOCATED OVER CENTRAL WY INTO WRN SD. PRESENT
INDICATIONS VIA THE 12Z NAM/15Z RAP ARE THAT THE FRONT WILL ENTER
DAWSON/VALLEY COUNTIES IN THE 7-8 PM TIME-FRAME...BE TO GRI BY 10
PM AND SE OF THE FCST AREA BY 2 AM.
WITH LONGWAVE TROF OVER THE ERN USA...THE WARM SECTOR IS VERY DRY.
MOST OF THE CLOUD COVER IS POST-FRONTAL. PCPN CHANCES AHEAD OF THE
FRONT WILL BE NIL.
TEMPS: 12Z LBF SOUNDING OFFERS A MAX TEMP OF 89F. ADJUSTED TEMPS
SLIGHTLY USING BIAS CORRECTED CONSENSUS MOS. THIS RAISED TEMPS
A COUPLE DEG W OF HWY 281 AND LOWERED THEM E OF HWY 281. ALSO
ADJUSTED TEMP CURVES TO ACCOUNT FOR MORE RAPID UPGLIDE THRU 18Z.
WINDS: MEAN SPEEDS IN THE MIXED LAYER WILL AVERAGE 25 KTS WITH A
MAX OF 31 KTS VIA BUFKIT. SO WHILE SFC WINDS WILL AVERAGE 15-25
MPH WITH G30 ...ONE-TIME PEAK GUSTS WILL PROBABLY REACH 34-37 MPH.
WINDS FROM 4 AM GID FCST ISSUANCE LOOK GOOD.
UPDATED FCST HAS ALREADY POSTED TO THE WEB. UPDATED ZFP/AFM/PFM
WILL POST SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 551 AM CDT WED OCT 3 2012/
AVIATION...12Z KGRI TAF. A SOUTH WIND WILL QUICKLY INCREASE
THROUGH THE MORNING AND WILL BE ESPECIALLY GUSTY BY EARLY
AFTERNOON. A STRONG COLD FRONT WILL SWING THROUGH DURING THE
EVENING...LIKELY JUST AFTER 10 PM. STRONG NORTHWEST WINDS ARE
EXPECTED BEHIND THE FRONT AND SHOULD LAST THROUGH MUCH OF THE
NIGHT. CLEAR SKIES THIS MORNING WILL GIVE WAY TO SOME MID AND HIGH
CLOUDS THIS EVENING. THERE MAY ALSO BE A SCATTERED LOW DECK OF
STRATUS CLOUDS BEHIND THE COLD FRONT THIS EVENING. WILL CONTINUE
TO CALL FOR VFR CONDITIONS...BUT WILL NEED TO MONITOR HOW LOW CLOUDS
DEVELOP BEHIND THE FRONT THIS EVENING.
PREV DISCUSSION... /ISSUED 417 AM CDT WED OCT 3 2012/
SHORT TERM...TODAY THROUGH 12Z SATURDAY. MAIN FORECAST CHALLENGE
CONTINUES TO BE THE APPROACHING COLD FRONT AND THE ASSOCIATED
WEATHER RELATED PHENOMENA. THE WIND FIELD COUPLED WITH LOW
RELATIVE HUMIDITY VALUES AHEAD OF THE COLD FRONT WILL PRESENT FIRE
WEATHER CONCERNS FOR TODAY. GOING WITH A RED FLAG WARNING FOR OUR
NEBRASKA COUNTIES THIS AFTERNOON.
TEMPERATURES AHEAD OF THE COLD FRONT WILL GET INTO THE MID 80S.
SOUTHERLY WIND SPEEDS AHEAD OF THE COLD FRONT WILL RANGE FROM 15 TO
20 MPH WITH GUSTS CLOSER TO 30 MPH. DEWPOINTS BEING IN THE MID TO
UPPER 30S AND LOWER 40S THIS AFTERNOON WILL PRODUCE RELATIVE
HUMIDITY VALUES IN THE UPPER TEENS AND LOWER 20S FOR A MAJORITY OF
THE CWA. GIVEN THESE CONDITIONS...A RED FLAG WAS WARRANTED THIS
AFTERNOON AND ONGOING THROUGH THE EARLY EVENING HOURS. THE TIMING
OF THE COLD FRONT COULD BE A KEY ISSUE TODAY WITH REGARDS TO FIRE
WEATHER CONCERNS. IF THE BOUNDARY SPEEDS UP ANYMORE THAN WHAT IS
FORECAST NOW...THESE CONDITIONS MIGHT NOT BE MET AS RELATIVE
HUMIDITY VALUES WILL QUICKLY BEGIN TO RISE AS THE FRONT PASSES.
THIS IS NOT A SLAM-DUNK EVENT...MAINLY BECAUSE THE TIMING OF THE
FRONT HAS NOT BEEN VERY CONSISTENT OVER THE LAST SEVERAL DAYS SO
CONFIDENCE IS LEANING TOWARDS MARGINAL. WITH THE BOUNDARY BEING
LESS THAN 24 HOURS FROM APPROACHING...THE GUIDANCE SHOULD HAVE A
DECENT GRIP ON THE SITUATION SO WENT WITH THE WARNING.
AS A RESULT OF LACKING MOISTURE CURRENTLY PROGGED TO BE IN THE
ATMOSPHERE TODAY...PRECIPITATION CHANCES BEHIND THE FRONT HAVE
DIMINISHED SIGNIFICANTLY ACROSS THE CWA FROM PREVIOUS FORECAST. THIS
ANALYSIS FALLS IN LINE WITH THE CRITERIA FOR FIRE WEATHER TODAY AS
FORECAST SOUNDINGS INDICATE A RATHER DRY ATMOSPHERE WITH AN
INVERTED-V PROFILE...WHERE THE LOWER LEVELS ARE ESPECIALLY DRY.
FURTHERMORE...CROSS SECTIONS OVER TIME SHOW VERY LITTLE MOISTURE IN
THE ATMOSPHERE DURING THE PASSAGE OF THE FRONT. PRECIPITATION
CHANCES ARE BEST BETWEEN 06Z AND 12Z WHERE MOISTURE BECOMES
EVIDENT...ALBEIT THESE CHANCES ARE STILL NOT VERY GOOD AS SLIGHT
CHANCES ARE CURRENTLY FORECAST. A BREAK IN PRECIPITATION CHANCES
OCCURS THURSDAY THROUGH THURSDAY NIGHT.
FRIDAY/FRIDAY NIGHT IS VERY INCONSISTENT BETWEEN THE MODELS AS FAR
AS PRECIP CHANCES GO. WITH THAT SAID...A CONVERGENCE ZONE IN THE
LOWER LEVELS WITH PLENTY OF MOISTURE IS FORECAST TO SET UP OVER THE
OUTLOOK AREA FRIDAY. TIMING AND COVERAGE WILL BE THE MAIN CHALLENGE
AS MODELS VARY IN OUTPUT. CONFIDENCE IS LOW FOR PRECIPITATION AT
THIS TIME AND SLIGHT CHANCES WILL BE FORECAST.
TEMPERATURES ON SATURDAY MORNING ARE GOING TO BE NEAR THE LOWER
30S FOR A MAJORITY OF THE CWA...HOWEVER...PRECIPITATION CHANCES
AND CLOUD COVER COULD PRODUCE SOME WARMER TEMPERATURES OVERNIGHT
THAN WHAT IS CURRENTLY FORECAST. OVERALL...ITS GOING TO BE A
RATHER CHILLY NIGHT ACROSS THE OUTLOOK AREA.
LONG TERM...SATURDAY THROUGH TUESDAY. THE BIG STORY WILL CENTER
AROUND THE COLD TEMPERATURES...WHICH WILL BE THE COLDEST WEATHER WE
HAVE SEEN SINCE EARLY MARCH. LOW TEMPERATURES MAY FALL BELOW
FREEZING AS EARLY AS SATURDAY MORNING...BUT ARE EVEN MORE LIKELY TO
FALL BELOW FREEZING BY SATURDAY NIGHT INTO SUNDAY MORNING. OUR
CURRENT FORECAST IS CALLING FOR LOWS SATURDAY NIGHT/SUNDAY MORNING
TO RANGE FROM THE MID 20S AROUND ORD...TO THE UPPER 20S IN THE TRI
CITIES...TO AROUND 30 IN NORTHERN KANSAS. THIS WILL MARK THE END OF
THE GROWING SEASON...WHICH FOR HASTINGS AND MOST LOCATIONS SOUTH OF
HASTINGS INTO NORTHERN KANSAS WILL BE THE LONGEST GROWING SEASON ON
RECORD AT AROUND 210 CONSECUTIVE DAYS WITH LOW TEMPERATURES ABOVE
32F. THE LAST TIME HASTINGS WAS 32F OR BELOW WAS BACK ON MARCH 9TH.
GRAND ISLAND HAD THEIR LAST FREEZE A LITTLE LATER ON APRIL 11TH AND
THUS THE GRAND ISLAND GROWING SEASON IS NOT EXPECTED TO BE A
RECORD...BUT IT SHOULD STILL BE AROUND THE 15TH OR 16TH LONGEST
GROWING SEASON ON RECORD.
IN ADDITION TO THE COLD OVERNIGHT LOWS...HIGH TEMPERATURES SATURDAY
ARE ONLY FORECAST TO BE AROUND 50 DEGREES WITH COOL AND DRY HIGH
PRESSURE OVERHEAD. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
TUESDAY BUT EXPECT HIGHS WILL GRADUALLY MODERATE INTO THE MID AND
UPPER 50S ON SUNDAY AND THEN 60S BY MONDAY AND TUESDAY. NORMAL HIGH
TEMPERATURES WOULD BE RIGHT AROUND 70F. DRY WEATHER IS EXPECTED TO
PERSIST THROUGH THE EXTENDED PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR NEZ039>041-
046>049-060>064-072>077-082>087.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...GUERRERO
LONG TERM/AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1015 AM EDT WED OCT 3 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY...BRINGING
SEASONABLY WARM TEMPERATURES TO THE OHIO VALLEY TODAY AND THURSDAY.
A COLD FRONT WILL PUSH THROUGH THE AREA ON FRIDAY. THIS WILL BRING
COOLER TEMPERATURES AND A GOOD CHANCE FOR RAIN FRIDAY THROUGH
SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KILN 03.12Z RAOB INDICATED A RATHER MOIST/MIXED BOUNDARY LAYER UP
TO ABOUT 875MB. VIS SATELLITE LOOP THIS MORNING HAS A RATHER
WIDESPREAD BKN/OVC STRATOCUMULUS FIELD NORTH OF THE OHIO
RIVER...AND DEEP ENOUGH NORTHWEST OF DAYTON /2KM LAYER/ TO SUPPORT
A LITTLE DRIZZLE WHICH FAA DAYTON RADAR /TDAY/ HAS PICKED UP ON
NICELY. RAP MODEL HAS PICKED UP ON THIS DEEPER MOISTURE AND LIFTS
IT NWWRD IN TIME AND ANY LIGHT DRIZZLE/VERY LIGHT RAIN SHOULD END
BY NOON IN THE NORTHWEST. LOW CLOUDS IN THE WEST/NORTHWEST WILL BE
STUBBORN AND MAY NEED TO UPDATE AND LOWER HIGH TEMPS IF BREAKS
DON/T BECOME MORE WIDESPREAD OVER THE NEXT FEW HOURS. IN THE
SOUTH/EAST...WILL CONTINUE A SLOW TREND OF DECREASING CLOUDS.
THESE AREAS MAY ALSO BE TOO WARM IN GIVEN FORECAST AND WILL TAKE A
LOOK AT 15Z OBS WITH A NOTION OF DROPPING TEMPS A BIT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
CLEARING SKIES WILL CONTINUE TO SPREAD NORTHWARD THIS EVENING AND
INTO THE OVERNIGHT HOURS. THIS WILL ALLOW TEMPERATURES TO COOL
INTO THE LOWER 50S FOR THE MOST PART. SOME PATCHY VALLEY FOG WILL
BE POSSIBLE WHERE CLEAR SKIES ARE PREVALENT THROUGHOUT THE NIGHT.
THE UPPER LOW THAT BEGAN MOVING OUT OF THE UPPER MISSISSIPPI
VALLEY TODAY...WILL SLIDE ACROSS THE OHIO VALLEY ON THURSDAY. A
FEW MODELS HINT AT A COUPLE OF SHOWERS DEVELOPING DURING THE DAY
THURSDAY ASSOCIATED WITH THIS TROUGH. HAVE OPTED TO CONTINUE A DRY
FORECAST FOR THE TIME BEING DUE TO THE LOW END CHANCES FOR THESE
SHOWERS. OTHERWISE...THURSDAY LOOKS TO BE PARTLY CLOUDY AND
SEASONABLY WARM.
A DEEP AND VERTICALLY STACKED LOW CENTERED ACROSS THE CENTRAL
US/CANADIAN BORDER WILL SLIDE EASTWARD ON THURSDAY NIGHT. A
SURFACE COLD FRONT EXTENDING FROM THIS LOW ACROSS MICHIGAN
SOUTHWESTWARD THROUGH MISSOURI WILL PUSH EASTWARD AND INTO OUR
WESTERN ZONES FRIDAY MORNING...AND ACROSS THE REMAINDER OF OUR ZONES
DURING THE DAY FRIDAY. THE LAGGING FRONTAL BOUNDARY ALOFT WILL BE A
SOURCE FOR CONVERGENCE AS PERIODIC SHORTWAVES RIDE EAST NORTHEAST
ALONG IT. THIS WILL CREATE PERIODS OF ENHANCED CHANCES FOR SHOWERS
STARTING FRIDAY MORNING AND EXTENDING THROUGH SATURDAY NIGHT. EACH
MODEL VARIES ON THEIR TIMING OF THE PASSAGE OF THESE FEATURES.
NOTABLY...THE STATISTICAL MODELS FAIL TO SHOW FOCUSED QPF FIELDS
DUE TO THE TIMING SPREADS...WHEREAS THE OPERATIONAL MODELS SUCH AS
THE NAM AND GFS SHOW THE INDIVIDUALLY FOCUSED PERIODS OF
PRECIPITATION. HOWEVER...DUE TO THE TIMING DIFFERENCES...THE POP
FIELD STARTS ITS FOCUS ACROSS THE NORTH AND GRADUALLY WORKS ITS
WAY SOUTH ACROSS OUR FORECAST AREA. THE GRADUAL SOUTHWARD SHIFT
WILL LIKELY HOLD TRUE FROM FRIDAY THROUGH SATURDAY NIGHT AS EACH
SUBSEQUENT WAVE FORCES THE COLD FRONT ALOFT FARTHER SOUTH.
THE QPF FORECAST WAS A BLEND OF THE GFS/NAM/ECMWF WHICH YIELDS AND
AREA AVERAGE OF ABOUT A HALF TO THREE QUARTERS OF AN INCH FRIDAY
MORNING THROUGH SATURDAY NIGHT.
WITH THE SURFACE COLD FRONT PUSHING THROUGH FRIDAY MORNING INTO
THE DAY FRIDAY...LOW LEVEL COLD ADVECTION WILL BE OCCURRING UNDER
CLOUDY SKIES FOR THE ENTIRE TIME FROM FRIDAY AFTERNOON THROUGH
SATURDAY NIGHT. THIS WILL RESULT IN WELL BELOW NORMAL HIGH
TEMPERATURES ON FRIDAY FOR ALL EXCEPT PERHAPS THE SOUTHEASTERN
ZONES. ON SATURDAY...RAIN COOLED...CLOUDY AND POST FRONTAL LOW
LEVELS WILL LIKELY YIELD HIGH TEMPERATURES MORE THAN 10 DEGREES
BELOW NORMAL.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
MUCH COOLER TEMPERATURES WILL BE IN PLACE ACROSS THE AREA SUNDAY
WITH HIGHS ONLY IN THE 50S. TEMPERATURES SUNDAY NIGHT INTO MONDAY
MORNING ARE EXPECTED TO DROP INTO THE LOW TO MIDDLE 30S. WITH
MOSTLY CLEAR SKIES...LIGHT WINDS...AND A COOL AIRMASS IN PLACE
OVERNIGHT SUNDAY NIGHT...THERE IS THE POTENTIAL FOR AREAS OF FROST
ACROSS THE REGION. SOUTHERLY FLOW DEVELOPS AND INCREASES ACROSS
THE AREA ON MONDAY ALLOWING TEMPERATURES TO REBOUND INTO THE UPPER
50S TO AROUND 60 BY MONDAY AFTERNOON. TEMPERATURES WILL BE WARMER
ON TUESDAY ACROSS THE AREA AS SOUTHERLY FLOW CONTINUES WITH HIGH
TEMPERATURES IN THE 60S.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
VARIABLE CIGS ARE PERSISTING ACROSS THE AREA THIS MORNING WITH THE
GENERAL TREND FOR MORE WIDESPREAD MVFR CIGS ACROSS THE WEST. THIS
IS CLOSER TO THE REMNANT WEAKENING SURFACE LOW OVER WESTERN
INDIANA THAT IS FORECAST TO CONTINUE TO WEAKEN AS IT LIFTS NORTH
THROUGH THIS AFTERNOON. THIS WILL ALLOW FOR DRIER AIR TO WORK IN
ACROSS THE AREA FROM THE SOUTH THROUGH THE DAY. FAIRLY GOOD 925
MB DRYING WILL PUSH UP INTO OUR AREA THROUGH THE MORNING HOURS.
THIS SHOULD ALLOW FOR THE MVFR CIGS TO LIFT UP INTO A VFR CU FIELD
BY THIS AFTERNOON...BEFORE SCATTERING OUT LATER THIS AFTERNOON.
EXPECT MOSTLY CLEAR SKIES OVERNIGHT WITH PERHAPS AN INCREASE IN
SOME MID LEVEL CLOUDS LATE TONIGHT INTO EARLY THURSDAY AS A
WEAKENING MID/UPPER LEVEL TROUGH APPROACHES FROM THE WEST.
.OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE FRIDAY NIGHT
AND SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...BINAU
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS TULSA OK
756 PM CDT THU OCT 4 2012
.DISCUSSION...
SHALLOW FRONT CONTINUES TO WEDGE ITS WAY SOUTH...LOCATED FROM
GROVE TO ADA AT 00Z. THE SOUTHWARD PUSH SHOULD HALT BY LATE
TONIGHT IN THE ELEVATED TERRAIN OF SOUTHEAST OK AND NORTHWEST AR.
THE LATEST DATA CONTINUES TO INDICATE SOME ELEVATED SHOWER AND
STORM DVLPMT LATER TONIGHT MAINLY ACROSS NORTHEAST OK.
HOWEVER...THE LATEST HRRR ISN`T VERY AGGRESSIVE WITH DVLPMT
TONIGHT...WHILE OTHER MODELS SUCH AS THE GFS AND ECMWF SHOW THE
HEAVIER QPF NORTH OF THE KANSAS BORDER. THUS...I HAVE TRENDED POPS
LOWER AND HAVE REDUCED THUNDER CHANCES TO JUST SCT FOR TONIGHT.
UPDATED TEXT PRODUCTS SENT.
LACY
&&
.PREV DISCUSSION... /ISSUED 624 PM CDT THU OCT 4 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 0Z TAFS... A SLOW MOVING COLD FRONT/WIND SHIFT IS CURRENTLY
WORKING ITS WAY SOUTHWARD ACROSS THE REGION. NORTHEAST OKLAHOMA
SITES HAVE ALREADY SHIFTED TO THE NORTH. KMLC AND ARKANSAS SITES
WILL FOLLOW BY 6Z. ARKANSAS SITES WILL HAVE THE BEST POSSIBILITY
FOR THUNDERSTORMS EARLY FRIDAY LASTING INTO MID MORNING.
WIDESPREAD MVFR CEILINGS ARE EXPECTED IN THE WAKE OF THE FRONT.
PREV DISCUSSION... /ISSUED 344 PM CDT THU OCT 4 2012/
DISCUSSION...
MUCH ANTICIPATED COLD FRONT HAS ARRIVED IN NORTHEAST OK AND WAS
POSITIONED NEAR I-44 AT 3 PM. AT THIS TIME ONLY MODEST PRESSURE
RISES NOTED IMMEDIATELY IN ITS WAKE AND THE FRONTS PROGRESS
SOUTHEAST WILL BE SLOW WITH THE FRONT LIKELY STALLING AS IT BEGINS
TO ENCOUNTER HIGHER TERRAIN. RELATIVELY HIGH DEW POINTS POOLING
NEAR THE BOUNDARY IN SOUTHERN OK HAVE RESULTED IN A NARROW AXIS OF
INSTABILITY...HOWEVER WARM MID LEVEL TEMPS KEEPING A STRONG CAP IN
PLACE AND CLOUD COVER HAS LIMITED SFC HEATING POTENTIAL SOMEWHAT.
STILL A SMALL THREAT OF AN ISOLATED STORM DEVELOPING ALONG
BOUNDARY BUT BETTER CHANCES ARRIVE LATE THIS EVENING WITH
STRENGTHENING WINDS ATOP THE COOL AIR EVENTUALLY RESULTING IN
WIDESPREAD ELEVATED THUNDERSTORMS NORTH OF THE FRONT. THE
INCREASING DEEP LAYER SHEAR DOES LEND AT LEAST SOME POSSIBILITY TO
ORGANIZED STORMS BUT OVERALL SEVERE THREAT LOOKS LOW AT THIS TIME.
PROGRESS OF THE FRONT WILL CONTINUE TO BE SLOW THROUGH THE DAY
FRIDAY WITH POST FRONTAL SHOWERS AND A FEW THUNDERSTORMS SHIFTING
EAST. THIS WILL LIKELY RESULT IN A WIDE RANGE OF HIGH TEMPS ACROSS
THE AREA AND A ZONE OF HIGH UNCERTAINTY FROM NW CORNER OF ARKANSAS
THROUGH SE OKLAHOMA. IN GENERAL HAVE GONE LOWER THE GUIDANCE FOR
MAX TEMPS...WITH EXCEPTION OF THOSE AREAS. BREAK IN PRECIP WILL
OCCUR FOR A TIME LATE FRIDAY BEFORE ANOTHER SURGE NORTH OF THE
FRONT FRIDAY NIGHT...WHICH BY THIS TIME SHOULD BE SOUTH OF THE RED
RIVER AS REINFORCING SHOT OF DEEPER COLD AIR ARRIVES.
APPROACHING UPPER LEVEL WAVE FROM THE NORTHWEST WILL KEEP RAIN
CHANCES GOING THROUGH SATURDAY WITH TEMPS STRUGGLING TO REACH 50
IN MANY AREAS...AND RECORD LOW MAXES VERY LIKELY AT TUL/FSM. AS
THIS WAVE PASSES TO THE NORTH...WILL BEGIN TO SEE SOME CLEARING
ACROSS NORTHERN AREAS. POTENTIAL FOR FREEZING TEMPS LOOKING HIGH
OVER FAR NORTHERN AREAS...HOWEVER THERE REMAINS SOME UNCERTAINTY
AS TO HOW MUCH SKIES WILL CLEAR AND HOW SOON. WITH THIS
UNCERTAINTY IN PLACE IN THE 5TH PERIOD OF THE FORECAST WILL NOT
ISSUE A FREEZE WATCH YET...BUT SOME HIGHLIGHTS LIKELY TO BE NEEDED
FOR SUN MORNING ESPECIALLY GIVEN HOW EARLY IN THE SEASON IT IS.
CONTINUED COOL SUNDAY WITH LIGHT WINDS...WHICH COME AROUND SOUTH
LATE. HOWEVER...NIT LATE ENOUGH TO KEEP TEMPS FROM FALLING AT OR A
LITTLE BELOW FREEZING IN THE MORE SHELTERED VALLEY AREAS TO THE
EAST AND SOUTH. A NICE WARM UP WILL OCCUR TUE AHEAD OF ANOTHER
APPROACHING FRONT WHICH WILL BRING ANOTHER CHANCE OF PRECIP TO THE
AREA WED/THU.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 49 54 41 51 / 50 30 20 30
FSM 65 71 47 51 / 20 90 60 70
MLC 55 60 45 51 / 40 50 70 50
BVO 47 54 39 53 / 50 20 20 30
FYV 62 65 41 49 / 30 90 30 60
BYV 58 63 40 50 / 30 100 30 60
MKO 52 57 43 51 / 30 60 30 50
MIO 47 52 39 53 / 60 50 20 30
F10 51 56 44 51 / 40 40 30 30
HHW 67 82 51 54 / 20 40 70 60
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1010 AM EDT WED OCT 3 2012
.SYNOPSIS...
AN OCCLUDED FRONT OVER CENTRAL PENNSYLVANIA WILL DRIFT SLOWLY EAST
TODAY. A FEW WEAK WAVES OF LOW PRESSURE WILL RIPPLE NORTH ALONG THIS
BOUNDARY THIS AFTERNOON INTO EARLY THURSDAY...BRINGING SCATTERED
SHOWERS TO THE REGION. WARMER THAN NORMAL TEMPERATURES ARE IN STORE
FOR TODAY THROUGH FRIDAY. A STRONG COLD FRONT WILL PUSH ACROSS THE
OHIO VALLEY AND GREAT LAKES REGION FOR FRIDAY AND SATURDAY...AND
WILL BRING THE NEXT CHANCE FOR SHOWERS FOLLOWED BY MUCH BELOW NORMAL
TEMPERATURES BY SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
AREAS OF FOG ARE DISSIPATING...WITH CLOUD BASES LIFTING QUICKLY THIS
MORNING.
HIGH PWAT AIR CONTINUING TO STREAM NORTH INTO THE REGION...ALL THE
WAY FROM THE GOMEX...WILL BRING SCATTERED AFTERNOON SHOWERS /AND
EVEN A FEW LOW-TOPPED TSRA NEAR AND TO THE EAST OF THE SUSQ
VALLEY/.
COSPA AND 12Z NAM DATA SHOWS MINIMAL CHCS FOR PRECIP TODAY.
HOWEVER...LATEST RAP INDICATES AN AREA OF LIGHT SHOWERS DRIFTING NE
ACROSS THE ENTIRE CWA VERY LATE THIS MORNING THROUGH THE AFTERNOON
HOURS. REGIONAL RADAR MOSAIC AND SFC OBS SHOW SOME OF THESE -SHRA
ALREADY SPREADING NNE FROM NRN VA...AND THE MD PANHANDLE INTO THE
LAUREL HIGHLANDS.
AS SIGNIFICANT BREAKS IN THE STRATO/ALTOCU CLOUD LAYER DEVELOP
DURING THE MIDDAY AND AFTERNOON HOURS...ML CAPE WILL INCREASE TO
BETWEEN 500-1000 J/KG ACROSS THE SUSQ VALLEY AND POINTS EAST. THIS
INSTABILITY INVOF THE AFOREMENTIONED SLOWING OCCLUDED FRONT WILL
COMBINE TO BRING THE BEST CHC FOR SHRA AND SOME LOW-TOPPED TSRA
NEAR...AND TO THE EAST OF A KIPT TO KSEG AND KMDT LINE.
ALTHOUGH LOCALIZED RAINFALL AMOUNTS AROUND 0.25 INCH ARE
POSSIBLE...BASIN AVERAGE AMOUNTS OVER THE NEXT 12 HOURS WILL BE
MAINLY UNDER 0.10 OF AN INCH.
THE WIND WILL GO WESTERLY IN THE WEST...AND VEER FROM S TO SW IN THE
LOWER SUSQ LATER LATE THIS AM. THIS LLVL DOWNSLOPE FLOW OFF THE
ALLEGHENY PLATEAU AND CENTRAL MTN WILL WARM AND DRY OUT THE BOUNDARY
LAYER A BIT. TEMPS SHOULD REACH A MID AFTERNOON MAX AROUND 80F FOR
THE SERN THIRD OF THE AREA...WHILE MOST OTHER LOCATIONS THROUGHOUT
THE CENTRAL RIDGE AND VALLEY REGION WILL MAKE IT TO THE M-U70S. THE
HIGHER TERRAIN OF THE NORTH AND WEST WILL SEE HIGH TEMPS IN THE
LOWER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
THE UPPER TROUGH TO OUR WEST DOES SWING EAST AND LIFT NORTH A BIT
TONIGHT AND WILL TRY TO SPIN UP A LITTLE WAVE ALONG THE OLD
FRONT...WHICH WILL BE DRAPED OVER FAR EASTERN PA AND DOWN INTO THE
CAROLINAS TONIGHT. ANY COHERENT SFC LOW WILL PASS JUST TO OUR
SE...BUT THE UPPER SUPPORT WILL FORCE SCT SHOWERS AS IT MOVES
PAST. TIMING IS A LITTLE UNCERTAIN...WITH THE WAVE JUST BEING
HANDLED IN THESE LAST FEW RUNS OF THE NCEP PROGS...BUT HAVE
BUMPED THE POPS UP TO MID-CHC LEVELS OVER THE SERN PART OF THE
FCST AREA TONIGHT AND KEPT THEM UP THAT HIGH FOR THE EAST DURING
THE FIRST HALF OF THURS. 8H TEMPS REMAIN HIGH...AND DEWPOINTS AS
WELL...SO MILD/WARM TEMPS CONTINUE TONIGHT AND THURSDAY. TEMPS
WILL MOST LIKELY RUN 10-12F HIGHER THAN NORMAL. SPOILED AS WE
HAVE BEEN...THE TEASER I LEAVE YOU WITH IS WHAT MAY COME TO PASS
LATE THIS WEEKEND. SEE BELOW FOR MORE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
GENERAL FLOW PATTERN
====================
THE 2 OCT 00 AND 12 UTC GLOBAL MODEL AND ENSEMBLE GUIDANCE
REMAINS IN AGREEMENT ON THE LARGE SCALE FLOW REGIME FCST ACROSS
NOAM. HIGH LATITUDE REX BLOCK IN THE NERN PAC WILL BE LESS
MIGRATORY THAN PREVIOUSLY FORECAST 24 HOURS AGO...WHICH SHOULD
ENSURE BROAD TROUGHING DOWNSTREAM OVER THE CENTRAL AND EASTERN
CONUS THROUGH THE PERIOD.
MODEL DIAGNOSTICS/PREFERENCES
=============================
CONCERNING THE MID-UPPER TROUGH WEAKENING/ACCELERATING NEWD OUT
OF THE MIDDLE MISSISSIPPI VALLEY ON D3...THE 12Z NAM IS ON THE
SLOWER/MORE AMPLIFIED SIDE OF MODEL SPREAD WITH LIFTING THE ENERGY
NORTHWARD THROUGH THE OHIO VALLEY INTO THE NORTHEAST THURSDAY.
OVERALL...THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THIS
FEATURE.
THE LAST TWO RUNS OF THE ECMWF ARE STRONGER THAN THE NAM/GFS WITH
THE SHORTWAVE ROTATING THROUGH THE NRN PLAINS/UPPER MS VLY SAT-SUN.
THIS LEADS TO UNCERTAINTY REGARDING THE PCPN PATTERN EVOLVING EWD
THROUGH THE OH VLY INTO THE MID-ATLANTIC REGION...PARTICULARLY ON
DAY 6 (SUN). A COMPROMISE SOLUTION SUPPORTS HIGH END CHC TO LOW LKLY
POPS ON DAY 5. THE ECMWF IS MORE BULLISH THAN THE GFS FOR PCPN FOR
DAY 6...AS IT DEVELOPS AN AREA OF LOW PRES OVR THE MID-ATLC
PIEDMONT.
THE MODEL DIFFS WITH THE AFOREMENTIONED SHORTWAVE IMPACT THE TRACK
OF ASSOC SURFACE CYCLONE DEEPENING OVER THE UPPER MIDWEST/GREAT
LAKES THUR-FRI...AND EWD PROGRESSION OF STRONG TRAILING COLD FRONT
PUSHING EWD THROUGH THE MIDWEST/OH VLY. A ECMWF/UKMET BLEND IS
PREFERRED HERE AS A MIDDLE OF THE ROAD SOLUTION.
THE GFS LOOKS MORE PROGRESSIVE EARLY NEXT WEEK WITH SHORTWAVE
ENERGY ROTATING WITHIN THE MEAN TROUGH OVR THE GREAT LAKES REGION.
WEATHER IMPACTS
================
LATE-WEEK WARM SPELL FOLLOWED BY SIGNIFICANT COOL DOWN INTO
EARLY NEXT WEEK...
WEAKENING SYSTEM EJECTING NEWD FROM THE MS VLY WILL ACCELERATE NEWD
THRU THE NORTHEAST STATES ON THUR...FOLLOWED BY S/W RIDGING AND SFC
HI PRES THURS NGT INTO FRI. THURS AND FRIDAY LOOK MILD AND MAINLY
DRY. FRIDAY COULD BE THE WARMEST DAY AHEAD OF A STRONG COLD FRONT
PUSHING EWD THROUGH THE MIDWEST. FRONTAL SHOWERS MAY REACH THE NW
MTNS BY THE FRI AFTN...WITH MORE ORGANIZED RAINS LKLY FRI NGT
INTO SAT AS THE WELL-DEFINED COLD FRONT SHIFTS SEWD THROUGH
CENTRAL PA. PCPN MAY CONTINUE ON SUNDAY IF THE ECMWF SOLUTION
VERIFIES.
THE MAIN WEATHER IMPACT THIS PERIOD WILL BE A SHOT OF UNSEASONABLY
COLD AIR INVADING THE REGION OVER THE WEEKEND...WITH BELOW NORMAL
TEMPS CONTINUING THROUGH EARLY NEXT WEEK. THE EARLY SEASON COOL
DOWN IS WELL-ADVERTISED AND SUPPORTED BY BELOW NORMAL 500MB
HEIGHTS AND 850MB TEMPS IN THE ENSEMBLE MEANS. THIS MIGHT LEAD TO
THE FIRST LAKE EFFECT SNOW SHOWERS OF THE SEASON OVR THE WRN
MTNS...WHICH IS NOT UNUSUAL FOR EARLY OCTOBER.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AREAS OF LIFR CIGS AND VSBYS WILL PERSIST UNTIL AROUND 15Z.
AFTERWARD...CONDITIONS WILL CONTINUE TO GRADUALLY IMPROVE TO MVFR OR
VFR INTO THE EARLY AFTERNOON. A FEW...HIGH RESOLUTION REGION MODELS
HINTS AT A FEW WEAK WAVES OF LOW PRESSURE LIFTING NE
TODAY...BRINGING SCATTERED SHOWERS AND BRIEF REDUCTIONS IN CIGS AND
VSBYS INTO THE MVFR CATEGORY.
ALSO SOME MODELS LIKE THE NAM SHOW ANOTHER WAVE LIFTING NE ACROSS
THE EAST TONIGHT. FOG COULD BECOME A PROBLEM AGAIN TONIGHT...
ESPECIALLY IN AREAS THAT GET DECENT CLEARING.
ANOTHER BATCH OF SHOWERS POSSIBLE ACROSS THE NW THU AFT.
A NOTABLY STRONGER COLD FRONT MOVES GRADUALLY EAST ACROSS THE STATE
LATE FRIDAY INTO SATURDAY. SOME MODELS HAVE THIS FRONT STALLING FOR
THE FIRST PART OF THE WEEKEND.
OUTLOOK...
THU...AM LOW CIGS POSSIBLE EAST. AREAS OF FOG EARLY.
PERHAPS A SHOWER FAR EAST AND NW.
FRI...A FEW SHOWERS POSSIBLE...MAINLY NORTH.
SAT...AREAS OF RAIN AND FOG WILL BE POSSIBLE.
SUN...MAINLY VFR...BUT AN ISOLATED SHOWER POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...LAMBERT/MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
917 PM CDT THU OCT 4 2012
.UPDATE...
A COLD FRONT CONTINUES PROGRESSING SLOWLY SOUTHEAST ACROSS NORTH
TEXAS THIS EVENING AND IS CURRENTLY ALONG A WHITESBORO...WEATHERFORD...
HAMILTON LINE AS OF 9 PM. THE RUC/HRRR CONTINUES TO BE THE BEST
MODEL WITH THE GFS AND TEXAS TECH 4KM WRF NOW HANDLING THE FRONT
POSITION PRETTY WELL TOO. ALL THE OTHER MODELS ARE STILL TOO SLOW.
IT APPEARS THE FRONT WILL PUSH A LITTLE FURTHER EAST THAN PREVIOUSLY
EXPECTED...BEFORE SLOWING DOWN OR STALLING LATE TONIGHT. BY MIDNIGHT
WE EXPECT THE FRONT TO BE ALONG A SHERMAN...ARLINGTON...LAKE WHITNEY...
TO JUST NORTH OF GATESVILLE LINE. THE FRONT SHOULD EASE A LITTLE
FURTHER EAST OVERNIGHT...BUT IS EXPECTED TO SLOW DOWN OR POSSIBLY
STALL BEFORE MAKING IT INTO WACO/TEMPLE/OR KILLEEN OVERNIGHT.
A SHORTWAVE IS CURRENTLY MOVING OVER THE TX/OK PANHANDLES WITH LIFT
FROM THIS FEATURE RESULTING IN SCATTERED SHOWERS ACROSS CENTRAL
AND EASTERN OK. AS THIS SYSTEM MOVES EAST OVERNIGHT WITHIN ZONAL
FLOW TO OUR NORTH...ISOLATED SHOWERS AND POSSIBLY AN ELEVATED
THUNDERSTORM WILL BE POSSIBLE NEAR THE RED RIVER VALLEY WHICH THE
CURRENT FORECAST HANDLES WELL. WE HAVE UPDATED TEMPERATURES AND
WINDS TO ACCOUNT FOR THE SLIGHTLY FURTHER EAST POSITION EXPECTED
OVERNIGHT.
05/
&&
.AVIATION...
UPDATE CONCERNING THE COLD FRONT...
THE FRONT CONTINUES TO MAKE A DECENT PROGRESSION EASTWARD THIS
EVENING. HAVE ALREADY AMENDED KFTW AND KAFW FOR FROPA BY 03Z. AT
THIS RATE...WILL LIKELY BE AMENDING KDFW AND KGKY WITHIN THE HOUR FOR
FROPA BY 04Z. THE WINDS BEHIND THE SHALLOW FRONT ARE LIGHT NORTH-
NORTHWEST.
AM STILL HOLDING OFF ON AMENDING KDAL FOR FROPA THIS EVENING. WILL
CONTINUE TO WATCH THE FRONT/S MOVEMENT AS SHORT TERM GUIDANCE
CONTINUES TO STALL THE FRONT OVER THE DFW METROPLEX THIS EVENING.
ONE OF THE SHORT TERM MODELS NOW BRINGS THE FRONT VERY CLOSE TO
THE WACO AREA OVERNIGHT OR POSSIBLY AROUND DAYBREAK FRIDAY.
HOWEVER...IT APPEARS THE SOUTHERN PORTION OF THE FRONT MAY BE
STALLING NOW AND WILL CONTINUE TO ASSESS THIS POSSIBILITY THROUGH
THE EVENING HOURS.
.../PREVIOUS AVIATION DISCUSSION/...
CONCERNS...TIMING OF COLD FRONT APPROACHING THE DFW TAF SITES THIS
EVENING AND THE RETURN OF MVFR CIGS OVERNIGHT.
VFR CONDITIONS AND SOUTH TO SOUTHEAST WINDS CONTINUE AT ALL THE
TAF SITES THIS EVENING. A COLD FRONT HAS MOVED INTO NORTH TEXAS
AND WILL BE APPROACHING THE WESTERN METROPLEX AIRPORTS LATER THIS
EVENING. THE CHALLENGE WITH THE FRONT IS THAT IT IS EXPECTED TO
STALL THIS EVENING...LIKELY SOMEWHERE ACROSS TARRANT COUNTY AND
WELL WEST OF KACT. BASED ON ALL AVAILABLE DATA AT THIS TIME...WILL
BRING THE FRONT INTO KAFW AND KFTW BY 04Z...BUT NOT INTO ANY OTHER
TERMINALS AT THIS TIME AND WILL CLOSELY MONITOR ITS PROGRESS THIS
EVENING. IT IS POSSIBLE THAT THE FRONT COULD MOVE INTO KDFW AND
POSSIBLY KGKY AROUND MIDNIGHT. THE FRONT SHOULD GET ANOTHER PUSH
FRIDAY MORNING AND MOVE THROUGH THE REMAINDER OF THE METROPLEX
AIRPORTS BUT EXPECT LIGHT NORTH TO NORTHWEST WINDS TO PREVAIL
BEHIND THE FRONT. THE FRONT WILL NOT REACH KACT IN THIS TAF
FORECAST PERIOD BUT SHOULD ARRIVE FRIDAY EVENING.
NO MATTER WHERE THE FRONT STALLS TONIGHT...MVFR CIGS WILL DEVELOP
OR MOVE NORTH ACROSS ALL THE TAF SITES OVERNIGHT. WILL TEMPO FOR
IFR CIGS AT KACT AROUND DAYBREAK. KACT SHOULD IMPROVE TO VFR
CONDITIONS BY THE EARLY AFTERNOON HOURS. UNFORTUNATELY...THE
METROPLEX AIRPORTS WILL LIKELY REMAIN SOCKED IN MVFR CIGS BEHIND
THE FRONT TOMORROW. HOWEVER...IF THE FRONT DOES NOT MOVE THROUGH
ANY PARTICULAR PART OF THE METROPLEX TOMORROW...CONDITIONS SHOULD
IMPROVE TO VFR AT ANY AIRPORTS THAT ARE NOT BEHIND THE FRONT.
THERE IS A SMALL CHANCE FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM BEHIND THE FRONT TOMORROW...HOWEVER...
CHANCES ARE TOO LOW TO MENTION IN THE DFW TAFS AT THIS TIME. THERE
COULD BE SOME RAIN ACTIVITY OVERNIGHT TONIGHT TO THE NORTH OF THE
METROPLEX.
82/JLD
82
&&
.PREV UPDATE...
.UPDATE...
THE COLD FRONT HAS NOW SURGED TO A LINE FROM JUST WEST OF BOWIE...
TO NEAR JACKSBORO...TO POSSUM KINGDOM LAKE...TO CISCO AS OF 5 PM.
THE AIRMASS IS SHALLOW WITH A DEPTH BETWEEN 1-2 KFT...THUS THE
MODELS ARE STRUGGLING WITH THE FRONTAL POSITION. THE RUC IS THE
ONLY MODEL EVEN CLOSE TO REALITY. THERE IS ALSO PLENTY OF STRATO-
CU BOTH AHEAD AND BEHIND THE FRONT DUE TO ISENTROPIC ASCENT UP
THROUGH 850 MB.
WE HAVE SPED UP THE FRONT AND BRING IT SOUTH-SOUTHEAST WITH THE
BEST PUSH OCCURRING ACROSS THE FAR WESTERN COUNTIES WHERE BEST
PRESSURE RISES WILL OCCUR ACROSS THE HIGHER TERRAIN. THE COLD FRONT
IS PROJECTED TO BE NEAR A SHERMAN...TO FORT WORTH...TO HAMILTON BY
MIDNIGHT. GUSTY NORTH WINDS OF 10 TO 20 MPH ARE EXPECTED BEHIND
THE FRONT...BUT SHOULD SETTLE DOWN OVERNIGHT. WE HAVE LOWERED LOW
TEMPERATURES OVERNIGHT INTO THE MID-UPPER 50S ACROSS THE NORTHWEST
COUNTIES BEHIND THE FRONT DUE TO THE SHALLOW COLD ADVECTION AND
EXPECTED CLOUD COVER...WHILE 60S TO LOWER 70S ARE ELSEWHERE.
CONFIDENCE ON EXACTLY WHERE THE FRONT MAY STALL THROUGH FRIDAY
MORNING REMAINS UNCERTAIN...BUT THIS IS OUR BEST GUESS AT THIS
POINT. WE HAVE LEFT LOW RAIN CHANCES NORTH OF I-20. FEEL MOST THE
ACTIVITY WILL BE IN THE FORM OF LIGHT SHOWERS...THOUGH STEEP MID
LEVEL LAPSE RATES ABOVE THE FRONTAL INVERSION MAY RESULT IN A FEW
ELEVATED THUNDERSTORMS ACROSS THE RED RIVER VALLEY CLOSER TO A
SHORTWAVE RIPPLING ACROSS OK/KS.
05/
&&
.PREV DISCUSSION... /ISSUED 225 PM CDT THU OCT 4 2012/
WATER VAPOR IMAGERY SHOWS A NICE LOOKING LOW PRESSURE SYSTEM
SPIRALING EAST FROM THE NORTHERN PLAINS INTO THE GREAT LAKES
REGION. A RESULTING COLD FRONT CONTINUES ITS PUNCH SOUTH THROUGH
THE SOUTHERN PLAINS AND WAS LOCATED JUST TO THE NORTHWEST OF THE
FORECAST AREA THIS AFTERNOON. PRESSURE RISES BEHIND THE FRONT AND
CURRENT MOMENTUM WOULD CARRY THE LEADING EDGE OF THIS BOUNDARY TO
NEAR THE DALLAS-FORT WORTH METROPLEX JUST AFTER SUNSET THIS
EVENING. THE FRONT SHOULD THEN BECOME STATIONARY AS THE INITIAL
NORTHERN BRANCH SHORTWAVE SWINGS EASTWARD INTO THE NORTHEASTERN
CONUS...BRINGING LIGHT AND VARIABLE WINDS IN THE VICINITY OF THE
FRONT NEAR THE METROPLEX TONIGHT.
FOR TOMORROW...A LONG WAVE TROUGH CENTERED OVER THE CENTRAL U.S.
WILL BEGIN DEEPENING AS THE NEXT SHORTWAVE DIVES SOUTHWARD OUT OF
CANADA INTO THE NORTHERN AND CENTRAL PLAINS. THE RESULT WILL BE A
FORCEFUL SECONDARY PUSH BEHIND THE FRONT...DRIVING THE BOUNDARY
SOUTH THROUGH NORTH AND CENTRAL TEXAS FRIDAY NIGHT THROUGH
SATURDAY. THIS WILL BRING GUSTY NORTH WINDS TO THE ENTIRE AREA AS
THE BOUNDARY CLEARS THE SOUTHERN COUNTIES SATURDAY AFTERNOON.
RAIN CHANCES WILL INITIALLY OCCUR TONIGHT OVER THE NORTHERN AND
NORTHWEST COUNTIES AS THE FRONT MOVES INTO THE AREA. SB CAPE IS
NOT IMPRESSIVE... BUT POCKETS OF MEAGER ELEVATED INSTABILITY
COULD LEAD TO A FEW ISOLATED STORMS LATE TONIGHT AND TOMORROW NEAR OR
JUST NORTH OF THE BOUNDARY. BY SATURDAY...THE PRIMARY MECHANISM
FOR RAIN PRODUCTION SHOULD BE ISENTROPIC UPGLIDE ABOVE THE
RELATIVELY SHALLOW FRONTAL LAYER...WHICH SHOULD BE MAINLY IN THE
FORM OF LIGHT RAIN OR DRIZZLE. CLOUDY SKIES WILL ALSO BE THE RULE
ON SATURDAY...WHICH IN COMBINATION WITH PERSISTENT COLD AIR
ADVECTION WILL NOT ALLOW TEMPS TO CLIMB MUCH ABOVE 60 IF AT ALL.
CONDITIONS SHOULD DRY OUT BY SUNDAY...GIVING WAY TO COOLER...DRIER
CONDITIONS FOR THE FIRST HALF OF NEXT WEEK. NEAR-NORMAL
TEMPERATURES WILL THEN RETURN AROUND THE MIDDLE PART OF NEXT WEEK
AS HIGH PRESSURE REDEVELOPS OVER THE CENTRAL U.S.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 65 84 53 58 47 / 10 10 30 30 20
WACO, TX 68 88 59 65 49 / 5 5 20 20 20
PARIS, TX 68 81 51 57 44 / 20 20 40 40 20
DENTON, TX 64 80 51 57 46 / 20 20 30 30 20
MCKINNEY, TX 68 82 50 57 46 / 20 20 30 30 20
DALLAS, TX 67 84 56 58 46 / 10 10 30 30 20
TERRELL, TX 70 84 53 60 46 / 10 10 30 30 20
CORSICANA, TX 68 87 57 64 48 / 10 10 20 30 20
TEMPLE, TX 68 88 60 68 49 / 5 5 10 20 20
MINERAL WELLS, TX 61 80 47 56 45 / 10 10 20 30 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/05
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
853 PM CDT THU OCT 4 2012
.AVIATION...
UPDATE CONCERNING THE COLD FRONT...
THE FRONT CONTINUES TO MAKE A DECENT PROGRESSION EASTWARD THIS
EVENING. HAVE ALREADY AMENDED KFTW AND KAFW FOR FROPA BY 03Z. AT
THIS RATE...WILL LIKELY BE AMENDING KDFW AND KGKY WITHIN THE HOUR FOR
FROPA BY 04Z. THE WINDS BEHIND THE SHALLOW FRONT ARE LIGHT NORTH-
NORTHWEST.
AM STILL HOLDING OFF ON AMENDING KDAL FOR FROPA THIS EVENING. WILL
CONTINUE TO WATCH THE FRONT/S MOVEMENT AS SHORT TERM GUIDANCE
CONTINUES TO STALL THE FRONT OVER THE DFW METROPLEX THIS EVENING.
ONE OF THE SHORT TERM MODELS NOW BRINGS THE FRONT VERY CLOSE TO
THE WACO AREA OVERNIGHT OR POSSIBLY AROUND DAYBREAK FRIDAY.
HOWEVER...IT APPEARS THE SOUTHERN PORTION OF THE FRONT MAY BE
STALLING NOW AND WILL CONTINUE TO ASSESS THIS POSSIBILITY THROUGH
THE EVENING HOURS.
.../PREVIOUS AVIATION DISCUSSION/...
CONCERNS...TIMING OF COLD FRONT APPROACHING THE DFW TAF SITES THIS
EVENING AND THE RETURN OF MVFR CIGS OVERNIGHT.
VFR CONDITIONS AND SOUTH TO SOUTHEAST WINDS CONTINUE AT ALL THE
TAF SITES THIS EVENING. A COLD FRONT HAS MOVED INTO NORTH TEXAS
AND WILL BE APPROACHING THE WESTERN METROPLEX AIRPORTS LATER THIS
EVENING. THE CHALLENGE WITH THE FRONT IS THAT IT IS EXPECTED TO
STALL THIS EVENING...LIKELY SOMEWHERE ACROSS TARRANT COUNTY AND
WELL WEST OF KACT. BASED ON ALL AVAILABLE DATA AT THIS TIME...WILL
BRING THE FRONT INTO KAFW AND KFTW BY 04Z...BUT NOT INTO ANY OTHER
TERMINALS AT THIS TIME AND WILL CLOSELY MONITOR ITS PROGRESS THIS
EVENING. IT IS POSSIBLE THAT THE FRONT COULD MOVE INTO KDFW AND
POSSIBLY KGKY AROUND MIDNIGHT. THE FRONT SHOULD GET ANOTHER PUSH
FRIDAY MORNING AND MOVE THROUGH THE REMAINDER OF THE METROPLEX
AIRPORTS BUT EXPECT LIGHT NORTH TO NORTHWEST WINDS TO PREVAIL
BEHIND THE FRONT. THE FRONT WILL NOT REACH KACT IN THIS TAF
FORECAST PERIOD BUT SHOULD ARRIVE FRIDAY EVENING.
NO MATTER WHERE THE FRONT STALLS TONIGHT...MVFR CIGS WILL DEVELOP
OR MOVE NORTH ACROSS ALL THE TAF SITES OVERNIGHT. WILL TEMPO FOR
IFR CIGS AT KACT AROUND DAYBREAK. KACT SHOULD IMPROVE TO VFR
CONDITIONS BY THE EARLY AFTERNOON HOURS. UNFORTUNATELY...THE
METROPLEX AIRPORTS WILL LIKELY REMAIN SOCKED IN MVFR CIGS BEHIND
THE FRONT TOMORROW. HOWEVER...IF THE FRONT DOES NOT MOVE THROUGH
ANY PARTICULAR PART OF THE METROPLEX TOMORROW...CONDITIONS SHOULD
IMPROVE TO VFR AT ANY AIRPORTS THAT ARE NOT BEHIND THE FRONT.
THERE IS A SMALL CHANCE FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM BEHIND THE FRONT TOMORROW...HOWEVER...
CHANCES ARE TOO LOW TO MENTION IN THE DFW TAFS AT THIS TIME. THERE
COULD BE SOME RAIN ACTIVITY OVERNIGHT TONIGHT TO THE NORTH OF THE
METROPLEX.
82/JLD
82
&&
.UPDATE...
THE COLD FRONT HAS NOW SURGED TO A LINE FROM JUST WEST OF BOWIE...
TO NEAR JACKSBORO...TO POSSUM KINGDOM LAKE...TO CISCO AS OF 5 PM.
THE AIRMASS IS SHALLOW WITH A DEPTH BETWEEN 1-2 KFT...THUS THE
MODELS ARE STRUGGLING WITH THE FRONTAL POSITION. THE RUC IS THE
ONLY MODEL EVEN CLOSE TO REALITY. THERE IS ALSO PLENTY OF STRATO-
CU BOTH AHEAD AND BEHIND THE FRONT DUE TO ISENTROPIC ASCENT UP
THROUGH 850 MB.
WE HAVE SPED UP THE FRONT AND BRING IT SOUTH-SOUTHEAST WITH THE
BEST PUSH OCCURRING ACROSS THE FAR WESTERN COUNTIES WHERE BEST
PRESSURE RISES WILL OCCUR ACROSS THE HIGHER TERRAIN. THE COLD FRONT
IS PROJECTED TO BE NEAR A SHERMAN...TO FORT WORTH...TO HAMILTON BY
MIDNIGHT. GUSTY NORTH WINDS OF 10 TO 20 MPH ARE EXPECTED BEHIND
THE FRONT...BUT SHOULD SETTLE DOWN OVERNIGHT. WE HAVE LOWERED LOW
TEMPERATURES OVERNIGHT INTO THE MID-UPPER 50S ACROSS THE NORTHWEST
COUNTIES BEHIND THE FRONT DUE TO THE SHALLOW COLD ADVECTION AND
EXPECTED CLOUD COVER...WHILE 60S TO LOWER 70S ARE ELSEWHERE.
CONFIDENCE ON EXACTLY WHERE THE FRONT MAY STALL THROUGH FRIDAY
MORNING REMAINS UNCERTAIN...BUT THIS IS OUR BEST GUESS AT THIS
POINT. WE HAVE LEFT LOW RAIN CHANCES NORTH OF I-20. FEEL MOST THE
ACTIVITY WILL BE IN THE FORM OF LIGHT SHOWERS...THOUGH STEEP MID
LEVEL LAPSE RATES ABOVE THE FRONTAL INVERSION MAY RESULT IN A FEW
ELEVATED THUNDERSTORMS ACROSS THE RED RIVER VALLEY CLOSER TO A
SHORTWAVE RIPPLING ACROSS OK/KS.
05/
&&
.PREV DISCUSSION... /ISSUED 225 PM CDT THU OCT 4 2012/
WATER VAPOR IMAGERY SHOWS A NICE LOOKING LOW PRESSURE SYSTEM
SPIRALING EAST FROM THE NORTHERN PLAINS INTO THE GREAT LAKES
REGION. A RESULTING COLD FRONT CONTINUES ITS PUNCH SOUTH THROUGH
THE SOUTHERN PLAINS AND WAS LOCATED JUST TO THE NORTHWEST OF THE
FORECAST AREA THIS AFTERNOON. PRESSURE RISES BEHIND THE FRONT AND
CURRENT MOMENTUM WOULD CARRY THE LEADING EDGE OF THIS BOUNDARY TO
NEAR THE DALLAS-FORT WORTH METROPLEX JUST AFTER SUNSET THIS
EVENING. THE FRONT SHOULD THEN BECOME STATIONARY AS THE INITIAL
NORTHERN BRANCH SHORTWAVE SWINGS EASTWARD INTO THE NORTHEASTERN
CONUS...BRINGING LIGHT AND VARIABLE WINDS IN THE VICINITY OF THE
FRONT NEAR THE METROPLEX TONIGHT.
FOR TOMORROW...A LONG WAVE TROUGH CENTERED OVER THE CENTRAL U.S.
WILL BEGIN DEEPENING AS THE NEXT SHORTWAVE DIVES SOUTHWARD OUT OF
CANADA INTO THE NORTHERN AND CENTRAL PLAINS. THE RESULT WILL BE A
FORCEFUL SECONDARY PUSH BEHIND THE FRONT...DRIVING THE BOUNDARY
SOUTH THROUGH NORTH AND CENTRAL TEXAS FRIDAY NIGHT THROUGH
SATURDAY. THIS WILL BRING GUSTY NORTH WINDS TO THE ENTIRE AREA AS
THE BOUNDARY CLEARS THE SOUTHERN COUNTIES SATURDAY AFTERNOON.
RAIN CHANCES WILL INITIALLY OCCUR TONIGHT OVER THE NORTHERN AND
NORTHWEST COUNTIES AS THE FRONT MOVES INTO THE AREA. SB CAPE IS
NOT IMPRESSIVE... BUT POCKETS OF MEAGER ELEVATED INSTABILITY
COULD LEAD TO A FEW ISOLATED STORMS LATE TONIGHT AND TOMORROW NEAR OR
JUST NORTH OF THE BOUNDARY. BY SATURDAY...THE PRIMARY MECHANISM
FOR RAIN PRODUCTION SHOULD BE ISENTROPIC UPGLIDE ABOVE THE
RELATIVELY SHALLOW FRONTAL LAYER...WHICH SHOULD BE MAINLY IN THE
FORM OF LIGHT RAIN OR DRIZZLE. CLOUDY SKIES WILL ALSO BE THE RULE
ON SATURDAY...WHICH IN COMBINATION WITH PERSISTENT COLD AIR
ADVECTION WILL NOT ALLOW TEMPS TO CLIMB MUCH ABOVE 60 IF AT ALL.
CONDITIONS SHOULD DRY OUT BY SUNDAY...GIVING WAY TO COOLER...DRIER
CONDITIONS FOR THE FIRST HALF OF NEXT WEEK. NEAR-NORMAL
TEMPERATURES WILL THEN RETURN AROUND THE MIDDLE PART OF NEXT WEEK
AS HIGH PRESSURE REDEVELOPS OVER THE CENTRAL U.S.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 84 53 58 47 / 10 10 30 30 20
WACO, TX 67 88 59 65 49 / 5 5 20 20 20
PARIS, TX 67 81 51 57 44 / 20 20 40 40 20
DENTON, TX 63 80 51 57 46 / 20 20 30 30 20
MCKINNEY, TX 69 82 50 57 46 / 20 20 30 30 20
DALLAS, TX 70 84 56 58 46 / 10 10 30 30 20
TERRELL, TX 69 84 53 60 46 / 10 10 30 30 20
CORSICANA, TX 67 87 57 64 48 / 10 10 20 30 20
TEMPLE, TX 67 88 60 68 49 / 5 5 10 20 20
MINERAL WELLS, TX 60 80 47 56 45 / 10 10 20 30 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/05
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
641 PM CDT THU OCT 4 2012
.AVIATION...
CONCERNS...TIMING OF COLD FRONT APPROACHING THE DFW TAF SITES THIS
EVENING AND THE RETURN OF MVFR CIGS OVERNIGHT.
VFR CONDITIONS AND SOUTH TO SOUTHEAST WINDS CONTINUE AT ALL THE
TAF SITES THIS EVENING. A COLD FRONT HAS MOVED INTO NORTH TEXAS
AND WILL BE APPROACHING THE WESTERN METROPLEX AIRPORTS LATER THIS
EVENING. THE CHALLENGE WITH THE FRONT IS THAT IT IS EXPECTED TO
STALL THIS EVENING...LIKELY SOMEWHERE ACROSS TARRANT COUNTY AND
WELL WEST OF KACT. BASED ON ALL AVAILABLE DATA AT THIS TIME...WILL
BRING THE FRONT INTO KAFW AND KFTW BY 04Z...BUT NOT INTO ANY OTHER
TERMINALS AT THIS TIME AND WILL CLOSELY MONITOR ITS PROGRESS THIS
EVENING. IT IS POSSIBLE THAT THE FRONT COULD MOVE INTO KDFW AND
POSSIBLY KGKY AROUND MIDNIGHT. THE FRONT SHOULD GET ANOTHER PUSH
FRIDAY MORNING AND MOVE THROUGH THE REMAINDER OF THE METROPLEX
AIRPORTS BUT EXPECT LIGHT NORTH TO NORTHWEST WINDS TO PREVAIL
BEHIND THE FRONT. THE FRONT WILL NOT REACH KACT IN THIS TAF
FORECAST PERIOD BUT SHOULD ARRIVE FRIDAY EVENING.
NO MATTER WHERE THE FRONT STALLS TONIGHT...MVFR CIGS WILL DEVELOP
OR MOVE NORTH ACROSS ALL THE TAF SITES OVERNIGHT. WILL TEMPO FOR
IFR CIGS AT KACT AROUND DAYBREAK. KACT SHOULD IMPROVE TO VFR
CONDITIONS BY THE EARLY AFTERNOON HOURS. UNFORTUNATELY...THE
METROPLEX AIRPORTS WILL LIKELY REMAIN SOCKED IN MVFR CIGS BEHIND
THE FRONT TOMORROW. HOWEVER...IF THE FRONT DOES NOT MOVE THROUGH
ANY PARTICULAR PART OF THE METROPLEX TOMORROW...CONDITIONS SHOULD
IMPROVE TO VFR AT ANY AIRPORTS THAT ARE NOT BEHIND THE FRONT.
THERE IS A SMALL CHANCE FOR ISOLATED TO SCATTERED SHOWERS AND
POSSIBLY A THUNDERSTORM BEHIND THE FRONT TOMORROW...HOWEVER...
CHANCES ARE TOO LOW TO MENTION IN THE DFW TAFS AT THIS TIME. THERE
COULD BE SOME RAIN ACTIVITY OVERNIGHT TONIGHT TO THE NORTH OF THE
METROPLEX.
82/JLD
&&
.UPDATE...
THE COLD FRONT HAS NOW SURGED TO A LINE FROM JUST WEST OF BOWIE...
TO NEAR JACKSBORO...TO POSSUM KINGDOM LAKE...TO CISCO AS OF 5 PM.
THE AIRMASS IS SHALLOW WITH A DEPTH BETWEEN 1-2 KFT...THUS THE
MODELS ARE STRUGGLING WITH THE FRONTAL POSITION. THE RUC IS THE
ONLY MODEL EVEN CLOSE TO REALITY. THERE IS ALSO PLENTY OF STRATO-
CU BOTH AHEAD AND BEHIND THE FRONT DUE TO ISENTROPIC ASCENT UP
THROUGH 850 MB.
WE HAVE SPED UP THE FRONT AND BRING IT SOUTH-SOUTHEAST WITH THE
BEST PUSH OCCURRING ACROSS THE FAR WESTERN COUNTIES WHERE BEST
PRESSURE RISES WILL OCCUR ACROSS THE HIGHER TERRAIN. THE COLD FRONT
IS PROJECTED TO BE NEAR A SHERMAN...TO FORT WORTH...TO HAMILTON BY
MIDNIGHT. GUSTY NORTH WINDS OF 10 TO 20 MPH ARE EXPECTED BEHIND
THE FRONT...BUT SHOULD SETTLE DOWN OVERNIGHT. WE HAVE LOWERED LOW
TEMPERATURES OVERNIGHT INTO THE MID-UPPER 50S ACROSS THE NORTHWEST
COUNTIES BEHIND THE FRONT DUE TO THE SHALLOW COLD ADVECTION AND
EXPECTED CLOUD COVER...WHILE 60S TO LOWER 70S ARE ELSEWHERE.
CONFIDENCE ON EXACTLY WHERE THE FRONT MAY STALL THROUGH FRIDAY
MORNING REMAINS UNCERTAIN...BUT THIS IS OUR BEST GUESS AT THIS
POINT. WE HAVE LEFT LOW RAIN CHANCES NORTH OF I-20. FEEL MOST THE
ACTIVITY WILL BE IN THE FORM OF LIGHT SHOWERS...THOUGH STEEP MID
LEVEL LAPSE RATES ABOVE THE FRONTAL INVERSION MAY RESULT IN A FEW
ELEVATED THUNDERSTORMS ACROSS THE RED RIVER VALLEY CLOSER TO A
SHORTWAVE RIPPLING ACROSS OK/KS.
05/
&&
.PREV DISCUSSION... /ISSUED 225 PM CDT THU OCT 4 2012/
WATER VAPOR IMAGERY SHOWS A NICE LOOKING LOW PRESSURE SYSTEM
SPIRALING EAST FROM THE NORTHERN PLAINS INTO THE GREAT LAKES
REGION. A RESULTING COLD FRONT CONTINUES ITS PUNCH SOUTH THROUGH
THE SOUTHERN PLAINS AND WAS LOCATED JUST TO THE NORTHWEST OF THE
FORECAST AREA THIS AFTERNOON. PRESSURE RISES BEHIND THE FRONT AND
CURRENT MOMENTUM WOULD CARRY THE LEADING EDGE OF THIS BOUNDARY TO
NEAR THE DALLAS-FORT WORTH METROPLEX JUST AFTER SUNSET THIS
EVENING. THE FRONT SHOULD THEN BECOME STATIONARY AS THE INITIAL
NORTHERN BRANCH SHORTWAVE SWINGS EASTWARD INTO THE NORTHEASTERN
CONUS...BRINGING LIGHT AND VARIABLE WINDS IN THE VICINITY OF THE
FRONT NEAR THE METROPLEX TONIGHT.
FOR TOMORROW...A LONG WAVE TROUGH CENTERED OVER THE CENTRAL U.S.
WILL BEGIN DEEPENING AS THE NEXT SHORTWAVE DIVES SOUTHWARD OUT OF
CANADA INTO THE NORTHERN AND CENTRAL PLAINS. THE RESULT WILL BE A
FORCEFUL SECONDARY PUSH BEHIND THE FRONT...DRIVING THE BOUNDARY
SOUTH THROUGH NORTH AND CENTRAL TEXAS FRIDAY NIGHT THROUGH
SATURDAY. THIS WILL BRING GUSTY NORTH WINDS TO THE ENTIRE AREA AS
THE BOUNDARY CLEARS THE SOUTHERN COUNTIES SATURDAY AFTERNOON.
RAIN CHANCES WILL INITIALLY OCCUR TONIGHT OVER THE NORTHERN AND
NORTHWEST COUNTIES AS THE FRONT MOVES INTO THE AREA. SB CAPE IS
NOT IMPRESSIVE... BUT POCKETS OF MEAGER ELEVATED INSTABILITY
COULD LEAD TO A FEW ISOLATED STORMS LATE TONIGHT AND TOMORROW NEAR OR
JUST NORTH OF THE BOUNDARY. BY SATURDAY...THE PRIMARY MECHANISM
FOR RAIN PRODUCTION SHOULD BE ISENTROPIC UPGLIDE ABOVE THE
RELATIVELY SHALLOW FRONTAL LAYER...WHICH SHOULD BE MAINLY IN THE
FORM OF LIGHT RAIN OR DRIZZLE. CLOUDY SKIES WILL ALSO BE THE RULE
ON SATURDAY...WHICH IN COMBINATION WITH PERSISTENT COLD AIR
ADVECTION WILL NOT ALLOW TEMPS TO CLIMB MUCH ABOVE 60 IF AT ALL.
CONDITIONS SHOULD DRY OUT BY SUNDAY...GIVING WAY TO COOLER...DRIER
CONDITIONS FOR THE FIRST HALF OF NEXT WEEK. NEAR-NORMAL
TEMPERATURES WILL THEN RETURN AROUND THE MIDDLE PART OF NEXT WEEK
AS HIGH PRESSURE REDEVELOPS OVER THE CENTRAL U.S.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 71 84 53 58 47 / 10 10 30 30 20
WACO, TX 67 88 59 65 49 / 5 5 20 20 20
PARIS, TX 67 81 51 57 44 / 20 20 40 40 20
DENTON, TX 63 80 51 57 46 / 20 20 30 30 20
MCKINNEY, TX 69 82 50 57 46 / 20 20 30 30 20
DALLAS, TX 70 84 56 58 46 / 10 10 30 30 20
TERRELL, TX 69 84 53 60 46 / 10 10 30 30 20
CORSICANA, TX 67 87 57 64 48 / 10 10 20 30 20
TEMPLE, TX 67 88 60 68 49 / 5 5 10 20 20
MINERAL WELLS, TX 60 80 47 56 45 / 10 10 20 30 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/05
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1052 PM PDT Tue Oct 2 2012
.SYNOPSIS...The cold front that moved through the region on
Tuesday will bring the first taste of Autumn to the area.
Temperatures will actually be below normal on Wednesday with most
locations seeing freezing temperatures Wednesday night. Dry and
seasonable weather will continue through the rest of the week and
the upcoming weekend.
&&
.DISCUSSION...
Update to the forecast to increase the shower activity over the
northeast. Bonners Ferry METAR is reporting rain and a spotter
east of there had a snow shower. The radar mosaic shows that the
upper low has now dropped southeastward to around Libby, MT.
Showers are wrapping around this low, coming from the northeast
into the Panhandle. Latest HRRR runs have picked up on this idea
and suggest showers could move as far west as Colville around
midnight and then move off to the southeast overnight. This would
actually bring a threat of showers to the Cd`A area. Accumulating
snow level will be above 3000 feet but a mix of rain/snow could
fall as low as 2000 feet with no accumulation. All of this
activity should be into Montana by sunrise Wednesday. RJ
&&
.AVIATION...
06Z TAFS: Winds will gradually decrease overnight. Blowing dust is
not expected to be a problem for the rest of tonight. Smoke from
wild fires has also been scoured out of the area by the cold
front. A large fire that developed south of KOMK isn`t expected to
cause smoke problems tonight due to the windy conditions. The
Wenatchee Complex fires are also not expected to cause smoke
problems at KEAT tonight. RJ
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 37 60 32 59 34 59 / 10 0 0 0 0 0
Coeur d`Alene 36 60 31 59 31 59 / 20 0 0 0 0 0
Pullman 35 60 30 58 29 58 / 0 0 0 0 0 0
Lewiston 41 66 38 65 38 65 / 0 0 0 0 0 0
Colville 32 65 30 64 29 64 / 20 0 0 0 0 0
Sandpoint 38 58 30 56 30 58 / 30 0 0 0 0 0
Kellogg 34 53 30 57 32 57 / 20 0 0 0 0 0
Moses Lake 40 67 33 65 33 65 / 0 0 0 0 0 0
Wenatchee 45 65 37 65 41 65 / 0 0 0 0 0 0
Omak 37 67 31 66 34 66 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...AIR QUALITY ALERT until Noon PDT Thursday for East Slopes
Northern Cascades-Okanogan Valley-Waterville Plateau-
Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
639 PM CDT THU OCT 4 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
257 PM CDT THU OCT 4 2012
MAIN FORECAST CONCERNS ON BREEZY NORTHWEST WINDS THIS EVENING AND
AGAIN ON FRIDAY. FOCUS THEN TURNS TO LOW PRECIPITATION CHANCES ON
SATURDAY AND TEMPERATURES THROUGH THE WEEKEND.
LATEST WATER VAPOR IMAGERY SHOWED A POTENT LOW PRESSURE SYSTEM OVER
NORTHERN MINNESOTA RESPONSIBLE FOR PRODUCING HEAVY...WET SNOW OVER
PORTIONS OF NORTHWEST MINNESOTA. SURFACE OBSERVATIONS INDICATED A
TIGHT PRESSURE GRADIENT OVER THE FORECAST AREA IN THE WAKE OF A
COLD FRONT THAT MOVED THROUGH THIS MORNING. THE TIGHT GRADIENT AND
COLD AIR ADVECTION BEHIND THE FRONT WAS KEEPING BREEZY
WEST/NORTHWEST ACROSS THE FORECAST AREA.
THE LOW IS EXPECTED TO LIFT NORTHEAST TONIGHT INTO SOUTHWEST ONTARIO
AND MEANDER EAST...JUST NORTH OF LAKE SUPERIOR. A TIGHT PRESSURE
GRADIENT WILL REMAIN IN PLACE OVER THE AREA AS THE REGION IS IN
BETWEEN THE LOW PASSING TO THE NORTH AND HIGH PRESSURE ATTEMPTING
TO BUILD INTO THE DAKOTAS. THIS WILL KEEP BREEZY CONDITIONS
THROUGH THIS EVENING. WINDS WILL TAPER OFF LATE IN THE EVENING FOR
LOCATIONS ALONG AND SOUTH OF INTERSTATE 90. NAM AND RUC LOW LEVEL
RELATIVE HUMIDITY FIELDS SHOWS A SCATTERED TO BROKEN STRATUS DECK
MOVING IN FROM THE NORTHWEST THIS EVENING AND MAKING IT TO ABOUT
THE INTERSTATE 90 CORRIDOR. HAVE INCREASED CLOUD COVER THIS
EVENING INTO THE OVERNIGHT HOURS ACROSS THESES AREAS. LOOK FOR LOW
TEMPERATURES TO FALL INTO THE 30S TONIGHT.
AN UPPER TROUGH WILL DIVE SOUTH INTO THE DAKOTAS AND NORTHERN
MINNESOTA ON FRIDAY OUT OF SOUTHERN MANITOBA...SASKATCHEWAN AND
ALBERTA AS THE LOW FILLS AND LIFTS NORTHEAST OVER JAMES BAY. PLAN ON
CONTINUED BREEZY NORTHWEST WINDS ACROSS THE AREA ON FRIDAY AS THE
PRESSURE GRADIENT REMAINS TIGHT. WIND SPEEDS ARE EXPECTED TO RANGE
FROM 14 TO 24 MPH. SOME GUSTS IN THE 25 TO 30 MPH RANGE ARE
POSSIBLE IN OPEN AREAS. THE GRADIENT WILL REMAIN TIGHTER THOUGH
THE DAY ACROSS CENTRAL INTO NORTH CENTRAL WISCONSIN SO HAVE
INCREASED WINDS GUSTS SLIGHTLY ACROSS THESE AREAS. HIGH
TEMPERATURES WILL RANGE FROM THE LOWER 40S ACROSS NORTHERN
WISCONSIN TO THE LOWER 50S OVER NORTHEAST IOWA. THE TROUGH IS
EXPECTED TO PUSH SOUTH INTO CENTRAL MINNESOTA AND NORTHERN
WISCONSIN LATE FRIDAY NIGHT INTO SATURDAY MORNING. CLOUDS WILL BE
ON THE INCREASE FROM NORTH TO SOUTH AS THE TROUGH MOVES IN. CANNOT
RULE OUT A LIGHT SPRINKLE OR SNOW SHOWER FRIDAY NIGHT INTO
SATURDAY MORNING ALONG AND NORTH OF THE INTERSTATE 94 CORRIDOR.
FORECAST SOUNDING ARE NOT SHOWING ENOUGH SATURATION FOR ICE ALOFT
SO THE PRECIPITATION COULD FALL AS SPRINKLES OR POSSIBLY FREEZING
SPRINKLES DEPENDING ON SURFACE TEMPERATURES. THERE APPEARS TO BE
ENOUGH SATURATION FOR PRECIPITATION BUT THERE REALLY IS NOT
APPRECIABLE LIFT SO CONCERNED THAT THE MAIN IMPACT FROM THE TROUGH
WILL BE JUST INCREASING STRATUS AND NO PRECIPITATION. WILL
MAINTAIN SLIGHT CHANCES FOR RAIN/SNOW SHOWERS OVER NORTH CENTRAL
WISCONSIN. PLAN ON LOW TEMPERATURES RANGING FROM THE UPPER 20S TO
LOWER 30S OVER NORTH CENTRAL WISCONSIN TO THE LOWER 30S OVER
NORTHEAST IOWA. GUIDANCE HAS BEEN TRENDING COOLER FRIDAY NIGHT BUT
CONCERNED THAT THE INCREASING CLOUD COVER AND PERSISTENT NORTHWEST
WINDS WILL LEAD TO SLIGHTLY WARMER TEMPERATURES. WILL HAVE TO KEEP
A CLOSE WATCH ON THE PROGRESSION OF THE STRATUS DECK FRIDAY NIGHT
AND WINDS. LOCATIONS THAT REMAIN CLEAR AND DECOUPLE COULD SEE
TEMPERATURES PLUMMET INTO THE MID 20S.
SATURDAY WILL BE A RATHER CHILLY FALL DAY ACROSS THE REGION. THE
TROUGH WILL CONTINUE ITS SOUTHWARD PUSH...LEADING TO AN EXPANSIVE
STRATUS DECK ACROSS MUCH OF THE FORECAST AREA. DECIDED TO MAINTAIN A
SLIGHT CHANCE FOR RAIN/SNOW SHOWERS OVER NORTH CENTRAL WISCONSIN AS
THE TROUGH MOVES THROUGH DURING THE MORNING HOURS. HAVE INCLUDED A
CHANCE OF FLURRIES ACROSS WEST CENTRAL WISCONSIN INTO SOUTHEAST
MINNESOTA AND NORTHEAST IOWA EARLY SATURDAY MORNING...THEN SWITCHED
OVER TO SPRINKLES LATE IN THE MORNING AS TEMPERATURES WARM. SEEING
THE SATURATION FOR SOME PRECIPITATION IN THE FORECAST SOUNDINGS BUT
VERY MINIMAL LIFT. THINKING THE TROUGH SHOULD BE ABLE TO PRODUCE
SOME VERY LIGHT PRECIP AS IT MOVES THROUGH. OTHERWISE...PLAN ON A
MOSTLY CLOUDY AND COOL DAY WITH HIGHS RANGING FROM THE LOWER 40S
OVER NORTHERN WISCONSIN TO THE UPPER 40S ACROSS NORTHEAST IOWA.
SATURDAY INTO SATURDAY NIGHT...850 MB TEMPERATURE STANDARDIZED
ANOMALIES WILL FALL TO AROUND -1.5 C BASED ON THE ECMWF....WHILE
THE NAM IS SUGGESTING -2.0 C. ANOMALIES THIS LOW SUGGEST THE
POTENTIAL FOR NEAR RECORD LOW TEMPERATURES ACROSS THE REGION. THE
COLD AIRMASS OVER THE REGION AND CLEARING SKIES LATE SATURDAY
NIGHT INTO EARLY SUNDAY MORNING WILL LEAD TO NEAR RECORD LOW
TEMPERATURES AND A HARD...GROWING SEASON ENDING FREEZE...WITH LOWS
FALLING INTO THE 20S. A FREEZE WARNING WILL BE NEEDED LATE
SATURDAY NIGHT INTO EARLY SUNDAY MORNING. SURFACE HIGH PRESSURE
WILL EDGE INTO THE REGION ON SUNDAY WITH MOSTLY SUNNY SKIES
EXPECTED. AFTER A COLD START TO THE DAY...LOOK FOR HIGH
TEMPERATURES TO REBOUND INTO THE UPPER 40S OVER NORTHERN WISCONSIN
TO THE LOWER 50S ACROSS NORTHEAST IOWA.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
257 PM CDT THU OCT 4 2012
04.12 MEDIUM RANGE MODELS IN REASONABLE AGREEMENT THROUGH THE
EXTENDED PERIOD. NORTHWEST FLOW ALOFT WILL CONTINUE INTO SUNDAY
NIGHT WITH SURFACE HIGH PRESSURE IN CONTROL. THE HIGH IS EXPECTED TO
SLIDE EAST OF THE AREA MONDAY AS A COLD FRONT DRIFTS SOUTH ACROSS
NORTHERN MINNESOTA INTO SOUTHERN NORTH DAKOTA. MEANWHILE...AN UPPER
TROUGH WILL MOVE THROUGH MONTANA AND INTO WESTERN NORTH DAKOTA.
SOUTHWEST FLOW AHEAD OF THE APPROACHING FRONT WILL HELP TEMPERATURES
CLIMB INTO THE UPPER 50S TO LOWER 60S ACROSS THE FORECAST AREA
MONDAY AFTERNOON. THE FRONT IS EXPECTED TO PUSH SOUTH INTO NORTHERN
WISCONSIN LATE MONDAY NIGHT BRINGING A SLIGHT CHANCE OF RAIN SHOWERS
TO NORTH CENTRAL WISCONSIN. THE FRONT WILL CONTINUE TO MOVE SOUTH
DURING THE DAY ON TUESDAY BRINGING A SLIGHT CHANCE OF RAIN SHOWERS
TO MUCH OF THE FORECAST AREA. HIGH PRESSURE IS EXPECTED TO BUILD
BACK INTO THE UPPER MISSISSIPPI RIVER VALLEY WEDNESDAY INTO THURSDAY
PROVIDING DRY AND QUIET WEATHER. LOOK FOR HIGH TEMPERATURES IN THE
50S ON WEDNESDAY...CLIMBING INTO THE MID 50S TO LOWER 60S THURSDAY
AFTERNOON.
&&
.AVIATION...TONIGHT AND FRIDAY
639 PM CDT THU OCT 4 2012
TIGHT PRESSURE GRADIENT IN THE WAKE OF THE COLD FRONT WILL PERSIST
THROUGH THE TAF PERIOD. ALTHOUGH GUSTS WILL DIMINISH A BIT
TONIGHT...ESPECIALLY AT KLSE...THE WINDS WILL PICK UP AGAIN AFTER
14Z FRIDAY. TAF SITES NOW CAUGHT BETWEEN TWO AREAS OF
CLOUDS...WITH THE CONCERN BEING THAT SOME OF THE STRATUS TO THE
NORTH WILL ROTATE ACROSS THE AREA LATER THIS EVENING. MODELS TEND
TO KEEP THIS MOISTURE NORTH OF THE AREA AND THUS JUST EXPECT SOME
SCATTERED CONDITIONS AT BOTH SITES. CANNOT RULE OUT A BRIEF PERIOD
OF BROKEN CEILINGS...BUT THESE CEILINGS WOULD LIKELY BE IN THE
VFR CATEGORY BETWEEN 030K-040K FEET.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
257 PM CDT THU OCT 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
340 AM CDT WED OCT 3 2012
.SHORT TERM...TODAY THROUGH FRIDAY
340 AM CDT WED OCT 3 2012
CONCERN REMAINS FOCUSED ON STRONG PATTERN-CHANGING COLD FRONT ON
THURSDAY AND RAIN CHANCES WITH IT.
SURFACE MAP EARLY THIS MORNING HAD A RIDGE OF HIGH PRESSURE
EXTENDING ACROSS THE GREAT LAKES INTO WISCONSIN AND IOWA. LIGHT/CALM
WINDS AND CLEAR SKIES HAS ALLOWED SOME AREAS OF FOG TO DEVELOP
ACROSS EASTERN INTO PORTIONS OF CENTRAL WISCONSIN. VISIBILITY
HOLDING AROUND 3/4SM AT VOLK FIELD IN JUNEAU COUNTY. THINKING THIS
WILL LIKELY BE THE EXTENT OF THE FOG...SO NO HEADLINES EXPECTED AT
THIS TIME. TEMPERATURES VARIED ACROSS THE AREA THIS MORNING...RANGING FROM
36 DEGREES AT BLACK RIVER FALLS WI WHERE WINDS WERE CALM...TO 54
DEGREES AT CHARLES CITY AND DECORAH IOWA WHERE WINDS WERE STIRRING A
BIT FROM THE SOUTHEAST. OTHERWISE...LOOKING AT THE BIGGER
PICTURE...WATER VAPOR IMAGERY SHOWING A VIGOROUS MID-LEVEL TROUGH
DIGGING INTO THE NORTHERN ROCKIES. THIS FEATURE WILL EVENTUALLY
AFFECT US BY THURSDAY.
03.00Z NCEP MODEL SUITE AS WELL AS THE GEM/ECMWF ALL IN PRETTY GOOD
AGREEMENT THROUGH THE PERIOD WITH REGARD TO OVERALL SYNOPTIC
SETUP.
FOR TODAY...LOOK FOR THE RIDGE AXIS OF HIGH PRESSURE TO DRIFT SLOWLY
SOUTHEAST OF THE AREA BY THIS AFTERNOON AS A COLD FRONT HANGS UP
OVER MN INTO SD/NEB. NAM SHOWING 925MB TEMPERATURES WARMING INTO THE
17-19C RANGE ACROSS THE AREA TODAY. THIS IS UP A COUPLE DEGREES C
FROM YESTERDAY. YESTERDAY/S HIGHS WERE IN THE LOWER 70S...SO MIDDLE
TO UPPER 70S CAN BE EXPECTED FOR TODAY. IT WILL BE PRETTY DRY AS
WELL...ESPECIALLY WEST OF THE MISSISSIPPI RIVER WHERE DEEPER MIXING
WILL OCCUR. ALTHOUGH NO HEADLINES ARE EXPECTED...AN ELEVATED FIRE
THREAT STILL EXISTS OVER THE MORE OPEN AND WIND-PRONE AREAS OF
NORTHEAST IA/SOUTHEAST MN. FOR FURTHER DETAILS...SEE FIRE WEATHER
SECTION BELOW.
STRONG SURFACE CYCLOGENESIS WILL TAKE PLACE TONIGHT AS THAT
AFOREMENTIONED VIGOROUS TROUGH OVER THE NORTHERN ROCKIES MOVES INTO
THE PLAINS. MAIN PRECIPITATION FOCUS WITH THIS CYCLOGENESIS WILL BE
FOCUSED ON STRONG FRONTOGENESIS ACROSS NORTHERN MN/ND ON THE
NORTHWEST SIDE OF THE STRENGTHENING LOW. DYNAMIC COOLING EXPECTED TO
SPREAD SNOW ACROSS THAT AREA. MEANWHILE...A MODERATE SURGE OF 850MB
MOISTURE TRANSPORT ALONG OF THE ADVANCING SURFACE COLD FRONT OUT OF
MN/IA TOWARD MORNING WILL COMBINE WITH NOSE OF 90KT 300MB JET FOR A
CHANCE OF SHOWERS ACROSS PORTIONS OF WESTERN IA. THESE SHOWERS ARE
EXPECTED TO HOLD JUST WEST OF THE AREA THROUGH SUNRISE.
FOR THURSDAY...COLD FRONT WILL CONTINUE TO SURGE EAST ACROSS THE
FORECAST AREA AS SURFACE LOW CONTINUES TO DEEPEN ACROSS NORTHERN MN.
850MB MOISTURE TRANSPORT AND LIFT AIDED BY THE NOSE OF 300MB JET
WILL CONTINUE TO PRODUCE A GOOD CHANCE OF SHOWERS THROUGH THE
MORNING. NAM ALSO SHOWING CORRIDOR OF 300-500J/KG 0-3KM MUCAPE
ADVANCING INTO THE AREA IN THE 12-18Z TIME FRAME SOUTH OF I-94.
SO...GIVEN THIS AND STRONG DYNAMICS OF THIS SYSTEM...CONTINUED THE
ISOLATED THUNDER MENTION AS WELL. APPEARS STRONG DRY SLOT WILL
OVERTAKE THE AREA IN THE AFTERNOON AS LOW OCCLUDES OVER NORTHERN MN.
LOOK FOR WEST WINDS TO INCREASE THROUGH THE DAY AS THIS DRY SLOT
MOVES INTO THE AREA. SUSTAINED WINDS EXPECTED TO BE IN THE 15 TO 20
MPH RANGE WITH GUST IN THE 30-35 MPH RANGE BY AFTERNOON. IN THE
MEANTIME...NAM SHOWS 925MB TEMPERATURES COLLAPSING INTO THE 5-10C BY
LATER IN THE AFTERNOON. THIS WILL MARK THE END OF THE UNSEASONABLY
WARM WEATHER THAT THE REGION HAS BEEN ENJOYING AS OF LATE.
ALSO...STRONG WINDS WILL LIKELY PUT A DENT IN THE VERY COLORFUL FALL
FOLIAGE THAT HAS ALSO BEEN ENJOYED AS OF LATE.
CLEARING/DRY SLOT WILL CONTINUE TO BE OVER THE AREA TONIGHT AS THE
LOW MOVES LITTLE ACROSS THE ARROWHEAD OF MN INTO WESTERN LAKE
SUPERIOR. COLD AIR ADVECTION UNDER THE LOW WILL DRAG 925MB
TEMPERATURES INTO THE ZERO TO -4C RANGE BY 12Z FRIDAY. AS A
RESULT...OVERNIGHT LOWS ACROSS THE FORECAST AREA ARE EXPECTED TO
DROP INTO THE LOWER/MIDDLE 30S. AND...WITH THE CONTINUATION OF BRISK
WEST WINDS...WIND CHILLS WILL BE IN THE 20S AFTER MIDNIGHT.
COOL/BLUSTERY CONDITIONS WILL CONTINUE FRIDAY AS THE LOW LIFTS
NORTHEAST INTO ONTARIO. STEEP LOW LEVEL LAPSE RATES WILL PRODUCE AN
EXPANSIVE AREA OF CUMULUS ALONG WITH SCATTERED RAIN/SNOW SHOWERS
ACROSS NORTHERN WI. BELIEVE THIS PRECIPITATION WILL STAY NORTH OF
THE AREA. OTHERWISE...LOOK FOR HIGHS IN THE 40S ACROSS NORTHERN
WISCONSIN...TO THE LOWER 50S ACROSS NORTHEAST IOWA INTO FAR
SOUTHWEST WI.
FRIDAY NIGHT WILL SEE A MID-LEVEL AND SURFACE TROUGH DROP SOUTHEAST
INTO NORTHERN WISCONSIN FOR A CHANCE OF LIGHT SNOW ACROSS
CLARK/TAYLOR COUNTIES AS LOWS THERE DIP INTO THE UPPER 20S. REST OF
THE AREA SHOULD SEE PARTLY CLOUDY SKIES WITH LOWS IN THE UPPER 20S
TO LOWER 30S.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
340 AM CDT WED OCT 3 2012
03.00Z GFS/ECMWF CONTINUE TO SHOW OVERALL COOL/CYCLONIC FLOW OVER
THE AREA THROUGH THE PERIOD FOR BELOW NORMAL TEMPERATURES. TROUGH
AFFECTING THE AREA FRIDAY NIGHT WILL DROP FARTHER SOUTHEAST INTO THE
AREA ON SATURDAY FOR A SMALL CHANCE OF SNOW IN THE EARLY MORNING
MAINLY ALONG AND NORTH OF I-94...CHANGING TO ALL RAIN BY LATER IN
THE MORNING. APPEARS ANY ACCUMULATING SNOW DOES NOT LOOK LIKELY AS
THE GROUND WILL BE TOO WARM. MODELS IN GOOD AGREEMENT WITH A FAIRLY
VIGOROUS EMBEDDED SHORTWAVE TROUGH/SURFACE LOW DROPPING INTO THE
AREA ON MONDAY/TUESDAY. APPEARS OUR AREA WILL BE IN THE WARM SECTOR OF THIS
CYCLONE WITH BEST LIFT/CHANCES FOR PRECIPITATION REMAINING ACROSS
NORTHERN MN INTO NORTHERN WI. OTHERWISE...LOOK FOR HIGHS IN THE 40S
ON SATURDAY...WARMING WELL INTO THE 50S MONDAY AND TUESDAY.
&&
.AVIATION...THROUGH 06Z THURSDAY
1153 PM CDT TUE OCT 2 2012
FORECAST CONCERN REMAINS ON VALLEY FOG POTENTIAL AT KLSE. AT
05Z...MODEL SOUNDINGS APPEAR TO BE ON TRACK WITH THE LOW LEVEL
WINDS PER BLUFF TOP OBSERVATIONS HERE AT THE OFFICE...WITH THE
WINDS INCREASING JUST IN THE PAST HOUR. THE 03.02Z RAP SOUNDING
DOES SHOW SOME 10 TO 12 KNOT WINDS ABOVE THE INVERSION...WITH
OTHERWISE LIGHTER WINDS ELSEWHERE AND THE 03.00Z NAM DOING THE
SAME FEEL VALLY FOG POTENTIAL WILL AGAIN BE MORE PATCHY IN NATURE
WITH A LOWER CEILING DEVELOPING INSTEAD. GFSMOS AND GFSLAMP DATA
HAVE BACKED OFF ON VISIBILITY RESTRICTIONS. THUS WILL GO WITH BCFG
IN THE TAF. OTHERWISE...VFR CONDITIONS EXPECTED WITH SOUTHERLY
WINDS AROUND 12 KNOTS DEVELOPING AT KRST BETWEEN 15Z- 01Z.
&&
.FIRE WEATHER...TODAY
340 AM CDT WED OCT 3 2012
DRY CONDITIONS COUPLED WITH SOUTHERLY WINDS OF 10-20 MPH WILL LEAD TO
SOME ELEVATED FIRE WEATHER CONCERNS ACROSS PORTIONS OF SOUTHEAST
MINNESOTA AND NORTHEAST IOWA. ALTHOUGH RELATIVE HUMIDITIES ARE
EXPECTED TO DROP INTO THE 20-30 PERCENT RANGE IN THE AFTERNOON
ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA...WINDS WILL BE TOO
LOW TO SUPPORT RED FLAG CRITERIA. DUE TO THE LIGHTER WINDS...NO FIRE
WEATHER HEADLINES WILL BE ISSUED AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
340 AM CDT WED OCT 3 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...RABERDING
FIRE WEATHER...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1153 PM CDT TUE OCT 2 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY
312 PM CDT TUE OCT 2 2012
THE MAIN FOCUS THROUGH THE REST OF THE WEEK IS WITH A POTENT COLD
FRONT THAT WILL MOVE ACROSS THE REGION EARLY ON THURSDAY AND BRING
AN END TO THIS FIRST RUN OF INDIAN SUMMER.
ANOTHER DAY OF PLEASANT AND DRY CONDITIONS ACROSS THE REGION TODAY
AS WE REMAIN SANDWICHED IN BETWEEN TWO LOW PRESSURE SYSTEMS WITH
HIGH PRESSURE IN BETWEEN OVER THE UPPER MISSISSIPPI VALLEY FROM
THE SURFACE THROUGH THE UPPER LEVELS OF THE ATMOSPHERE. THIS RIDGE
AXIS WILL SLOWLY DRIFT TO THE EAST TONIGHT INTO TOMORROW AS THE
MID LEVEL TROUGH TO THE SOUTHEAST AND THE OTHER TROUGH OVER SOUTH
CENTRAL CANADA MAKE SOME SLOW PROGRESS EASTWARD. WITH THE CORE OF
THE RIDGE OVERHEAD FOR MUCH OF THE OVERNIGHT PERIOD...SKIES WILL
BE CLEAR WITH WINDS LIGHT FROM THE SURFACE ON UP THROUGH 15KFT.
THIS SETUP SHOULD PRODUCE SOME RADIATIONAL FOG THAT FORMS IN LOW
SPOTS AND VALLEYS...PARTICULARLY ACROSS WESTERN WISCONSIN. LOW
LEVEL WINDS AROUND 925MB DO PICK UP TOWARD DAYBREAK ACROSS
SOUTHEAST MINNESOTA...BUT ARE STILL LIGHT ENOUGH AT 10KTS THAT
SOME RIVER VALLEY FOG SHOULD FORM.
THE WARMEST DAY OF THE WEEK WILL BE ON WEDNESDAY AS THE TROUGH
OVER THE NORTHERN PLAINS BECOMES MORE NEGATIVELY TILTED AND A
DEEPENING SURFACE LOW FORMS IN SOUTHEAST SOUTH DAKOTA WITH SURFACE
WINDS INCREASING OUT OF THE SOUTH ACROSS THE REGION. THE CORE OF
THE WARMEST LOW LEVEL AIR REMAINS OFF TO THE WEST...BUT WITH FULL
SUNSHINE AND SOUTHERLY WINDS SURFACE TEMPERATURES SHOULD BE ABLE
TO CLIMB UP INTO THE UPPER 70S TO AROUND 80. THIS SETUP MAY LEAD
TO SOME FIRE WEATHER CONCERNS WHICH ARE OUTLINED IN THE FIRE
WEATHER SECTION IN THIS AFD DOWN BELOW.
THE MAIN FORECAST CHALLENGE IS WITH THE TIMING OF THE COLD FRONT
PASSAGE ALONG WITH HOW LIKELY IT WILL BE THAT IT WILL RAIN AS THE
FRONT COMES THROUGH. THERE IS NOT A LOT OF CONSISTENCY AMONGST THE
02.12Z GUIDANCE WEDNESDAY NIGHT INTO THURSDAY WITH THE COLD FRONT
AND LOW PRESSURE SYSTEM AS IT MOVES THROUGH THE REGION. THE 02.12Z
NAM AND GFS ARE THE FASTEST WITH THE COLD FRONT REACHING EASTERN
WISCONSIN BY 18Z THURSDAY...THOUGH THE NAM SHOWS A MUCH MORE
OCCLUDED LOW TO THE NORTH ON THURSDAY. THE CONCERNING PART OF
THE LAST FEW MODEL RUNS HAS BEEN THE TREND TOWARD GOING WITH A
DRIER SOLUTION DESPITE THE STRONG DYNAMIC FORCING. GIVEN THE
LATEST TRENDS...IT APPEARS THAT THE BETTER CHANCES FOR THE
CROSSOVER IN FORCING AND MOISTURE WILL BE ACROSS NORTHEAST IOWA
INTO FAR SOUTHEAST MINNESOTA AND WESTERN WISCONSIN THURSDAY
MORNING ALONG AND JUST BEHIND THE FRONTAL PASSAGE. INSTABILITY
LOOKS MARGINAL AT BEST...BUT SOME OF THE CONVECTIVE MODELS DO SHOW
SOME STORMS DEVELOPING AS THE FRONT COMES THROUGH...SO HAVE LEFT
SOME ISOLATED THUNDER MENTION IN ON THURSDAY MORNING. COLD AIR
WILL QUICKLY MOVE IN ACROSS THE REGION WITH HIGH TEMPERATURES
LIKELY COMING IN THE EARLY MORNING HOURS BEFORE DROPPING OR
STABILIZING THROUGH THE REST OF THE DAY. WINDS WILL ALSO BECOME
GUSTY UP TO 25-30KTS THROUGH THE REST OF THE AFTERNOON AS THE DRY
SLOT MOVES IN WHICH WILL HELP TO LIKELY END THE COLORFUL FOLIAGE
THAT HAS BEEN PRESENT THROUGH MUCH OF THE REGION OVER THE PAST FEW
WEEKS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
312 PM CDT TUE OCT 2 2012
NOT MUCH CONFIDENCE IN THE EXTENDED PERIOD FROM THE WEEKEND INTO
EARLY NEXT WEEK AS THE 02.12Z GFS PUSHES FOR A COLDER SOLUTION
WITH A SYSTEM DROPPING THROUGH THE REGION ON MONDAY WHILE THE
02.12Z ECMWF IS WARMER AFTER THE INITIAL COLD SURGE GOING INTO
MONDAY AND TUESDAY AND LINGERS SOME PRECIPITATION ALONG THE
INVERTED TROUGH THIS WEEKEND. THERE AT LEAST IS AGREEMENT THAT
TEMPERATURES WILL STAY BELOW NORMAL THROUGH THE WEEKEND WITH 850MB
TEMPERATURES DROPPING DOWN TO -6C FRIDAY THROUGH SUNDAY BEFORE LOW
LEVEL WARM AIR ADVECTION KICKS BACK IN SUNDAY NIGHT. BEYOND
THAT...THE 02.12Z GFS ADVECTS COLDER AIR BACK IN WHILE THE 02.12Z
ECMWF STRONGLY ADVECTS WARMER AIR IN FROM THE SOUTHWEST. THE GFS
HAS AT LEAST HAD SOME CONSISTENCY TO IT WITH THE MONDAY
SYSTEM...SO FEEL A LITTLE STRONGER TOWARD GOING IN THAT DIRECTION
FOR NOW WITH KEEPING THE COOLER AIR AROUND INTO NEXT WEEK.
PRECIPITATION TYPES COULD BE AN ISSUE...BUT ITS RATHER BORDERLINE
RIGHT NOW FOR WHETHER IT WOULD BE COLD ENOUGH TO SUPPORT A MIX OF
RAIN/SNOW. THE INVERTED SURFACE TROUGH WILL HAVE TO BE WATCHED
THIS WEEKEND AS WELL FOR PRECIPITATION CHANCES IF THE HIGH DOES
NOT BUILD IN AS STRONGLY AS THE GFS IS FORECASTING.
&&
.AVIATION...THROUGH 06Z THURSDAY
1153 PM CDT TUE OCT 2 2012
FORECAST CONCERN REMAINS ON VALLEY FOG POTENTIAL AT KLSE. AT
05Z...MODEL SOUNDINGS APPEAR TO BE ON TRACK WITH THE LOW LEVEL
WINDS PER BLUFF TOP OBSERVATIONS HERE AT THE OFFICE...WITH THE
WINDS INCREASING JUST IN THE PAST HOUR. THE 03.02Z RAP SOUNDING
DOES SHOW SOME 10 TO 12 KNOT WINDS ABOVE THE INVERSION...WITH
OTHERWISE LIGHTER WINDS ELSEWHERE AND THE 03.00Z NAM DOING THE
SAME FEEL VALLY FOG POTENTIAL WILL AGAIN BE MORE PATCHY IN NATURE
WITH A LOWER CEILING DEVELOPING INSTEAD. GFSMOS AND GFSLAMP DATA
HAVE BACKED OFF ON VISIBILITY RESTRICTIONS. THUS WILL GO WITH BCFG
IN THE TAF. OTHERWISE...VFR CONDITIONS EXPECTED WITH SOUTHERLY
WINDS AROUND 12 KNOTS DEVELOPING AT KRST BETWEEN 15Z- 01Z.
&&
.FIRE WEATHER...WEDNESDAY
312 PM CDT TUE OCT 2 2012
DRY CONDITIONS COUPLED WITH SOME GUSTY WINDS OF 15-20 MPH MAY LEAD
TO SOME NEAR CRITICAL FIRE WEATHER CONCERNS ACROSS PORTIONS OF
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. A LOW PRESSURE SYSTEM
WILL MOVE ACROSS THE DAKOTAS AND MINNESOTA TOMORROW WITH WARM AND
DRY SOUTHERLY WINDS IN PLACE AHEAD OF THIS SYSTEM. RELATIVE
HUMIDITIES ARE FORECAST TO DROP INTO THE 20-30 PERCENT RANGE IN
THE AFTERNOON ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA THOUGH
WINDS WILL BE TOO LOW AT 10-20MPH TO SUPPORT RED FLAG CONDITIONS.
GIVEN THE DRY CONDITIONS ALREADY IN PLACE AND THE FACT THAT A LOT
OF VEGETATION IS LIKELY DEAD TO DO A KILLING FREEZE LAST
WEEK...FIRE WEATHER CONDITIONS ARE EXPECTED TO BE NEAR
CRITICAL. DUE TO THE LIGHT WINDS...NO FIRE WEATHER WATCHES OR RED
FLAG WARNINGS WILL BE ISSUED AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
312 PM CDT TUE OCT 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
FIRE WEATHER...HALBACH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
424 AM EDT FRI OCT 5 2012
.SYNOPSIS...
A FRONTAL BOUNDARY JUST OFF THE CAROLINA COAST THIS MORNING WILL
PUSH FARTHER OUT TO SEA TODAY. WEAK HIGH PRESSURE WILL BE OVER
THE FORECAST AREA TODAY THROUGH SATURDAY. A COLD FRONT WILL MOVE
INTO THE AREA SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE WEAK FRONTAL BOUNDARY HAS GONE AND HIGH PRESSURE HAS BEGUN TO
BUILD IN ACROSS THE FORECAST AREA THROUGH TODAY INTO TONIGHT.
SATELLITE LOOPS SHOWS THE BACK EDGE OF A CIRRUS SHIELD CONTINUES
TO RUN SW TO NE ACROSS THE WESTERN PORTION OF THE CWA. AT TIMES
THE CLOUDINESS HAS BEEN SCATTERED AND THIN...BUT CURRENTLY IS A
BIT THICKER AND MORE WIDESPREAD. AMOUNT/THICKNESS OF HIGH
CLOUDINESS TOWARD DAYBREAK WILL WEIGH ON THE AMOUNT OF
RADIATIONAL COOLING AND FOG FORMATION. PATCHY FOG...POSSIBLY
LOCALLY DENSE...IS POSSIBLE NEAR SUNRISE. WEAK HIGH PRESSURE WILL
DOMINATE TODAY AND TONIGHT. MODEL TIME SECTIONS SHOW A RELATIVELY
DRY AIRMASS ACROSS THE AREA THROUGH THE PERIOD. GUIDANCE AND
LOCAL NUMBERS VERY CLOSE FOR TEMPERATURES AND WILL STAY NEAR
CONSENSUS THROUGH THE PERIOD.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
BY SATURDAY INTO SATURDAY NIGHT...ALL OF THE MODELS INDICATE THAT
A FRONTAL BOUNDARY WILL BE APPROACHING THE AREA FROM THE WEST.
WITH FRONTAL BOUNDARY NEARLY PARALLEL TO MID/UPPER FLOW...LOOKS
LIKE THE FRONT WILL BE A SLOW MOVER INTO THE REGION. WILL LIKELY
HAVE TO WAIT FOR MORE VIGOROUS SHORTWAVE ENERGY EXPECTED TO MOVE
ACROSS THE MIDWEST/GREAT LAKES REGION BY SUNDAY FOR FRONT TO MOVE
INTO REGION. THE ECMWF IS STILL THE SLOWEST OF THE MODELS...BUT
GFS/NAM ALONG WITH ECMWF HAVE COME INTO BETTER AGREEMENT WITH THE
00Z MODEL RUN. GUIDANCE AND LOCAL NUMBERS SHOW WARM TEMPERATURES
FOR THE PERIOD WITH TEMPERATURES RUNNING NEARLY 10 DEGREES ABOVE
NORMAL. WILL STAY NEAR A CONSENSUS OF THE GUIDANCE AT THIS TIME
THROUGH THE PERIOD. HPC ANALYSIS INDICATES A COMPROMISE BETWEEN
THE SOLUTIONS MAY BE THE BEST TIMING FOR THE FRONT. WITH FRONT
APPROACHING BY SATURDAY NIGHT...HAVE INCLUDED A SLIGHT CHANCE/LOW
CHANCE OF SHOWERS ACROSS THE NORTH/NORTHWEST MIDLANDS. GUIDANCE
NUMBERS ONCE AGAIN VERY CONSISTENT AND WILL STAY NEAR CONSENSUS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
LATEST ECMWF/GFS CONTINUES TO SHOW A COLD FRONT THAT WILL BE
MOVING INTO THE AREA ON SUNDAY. A COMPROMISE BETWEEN THE FASTER
GFS AND SLOWER ECMWF WILL BE USED. CONTINUED WITH A CHANCE OF
SHOWERS SUNDAY/SUNDAY NIGHT. SREF ENSEMBLE GUIDANCE INDICATED THE
BEST CHANCE FOR RAIN TO BE SUNDAY AFTERNOON/EVENING. TEMPERATURES
WILL BE TRICKY ON SUNDAY BASED ON THE ARRIVAL OF THE FRONTAL
BOUNDARY...BUT EXPECT COOLER TEMPERATURES BY MONDAY. BEHIND THE
FRONT...COOL HIGH PRESSURE WILL BUILD OVER THE REGION MONDAY
THROUGH TUESDAY NIGHT. TEMPERATURES SHOULD BEGIN TO GRADUALLY RISE
THROUGH THE REMAINDER OF THE LONG TERM PERIOD...BUT REMAIN BELOW
NORMAL. LOOKS LIKE THE AREA WILL SEE THE COOLEST TEMPERATURES OF
THE FALL PERIOD BY TUESDAY MORNING AS MANY AREAS WILL FALL INTO
THE MIDDLE TO UPPER 40S. TEMPERATURES WILL GRADUALLY MODERATE
WEDNESDAY INTO THURSDAY. ANOTHER DRY COLD FRONT APPROACHES FROM
THE WEST LATE WEDNESDAY INTO EARLY THURSDAY. EXPECT TEMPERATURES
TO REMAIN BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THIN HIGH CLOUDS CONTINUES ACROSS THE AREA BUT WITH LIGHT
BOUNDARY LAYER WINDS...HIGH NEAR-SURFACE RELATIVE HUMIDITY...FOG
DEVELOPING AT AREA TERMINALS. RADIATION FOG SCHEME ALONG WITH
LATEST HRRR AND LAMP SUGGEST WIDESPREAD MVFR THROUGH 09Z THEN
LIFR/IFR AROUND 12Z POSSIBLE ESPECIALLY AT AGS/OGB. VISIBILITY MAY
STAY UP AT DNL...CROSS OVER TEMPERATURE LOWER THAN OTHER TERMINAL
SITES AND STRATUS NOT FORECAST.
EXTENDED AVIATION OUTLOOK...REDUCED VISIBILITY IN EARLY MORNING FOG
POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
07/77
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
105 AM EDT FRI OCT 5 2012
.SYNOPSIS...
A FRONTAL BOUNDARY JUST OFF THE CAROLINA COAST WILL FINALLY PUSH
FURTHER OUT TO SEA OVERNIGHT. WEAK HIGH PRESSURE WILL BE OVER THE
FORECAST AREA TODAY THROUGH SATURDAY. A COLD FRONT WILL MOVE INTO
THE AREA SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE WEAK FRONTAL BOUNDARY HAS GONE AND HIGH PRESSURE WILL BUILD
ACROSS THE FORECAST AREA OVERNIGHT. THE BACK EDGE OF A CIRRUS
SHIELD CONTINUES TO RUN SW TO NE ACROSS THE WESTERN PORTION OF THE
CWA. AT TIMES THE CLOUDINESS IS SCATTERED AND THIN.
AMOUNT/THICKNESS OF HIGH CLOUDINESS TOWARD MORNING WILL WEIGH ON
THE AMOUNT OF RADIATIONAL COOLING AND FOG FORMATION. PATCHY
FOG...POSSIBLY LOCALLY DENSE...IS POSSIBLE NEAR SUNRISE. WILL
CONTINUE TO MONITOR AREA OBS IN CASE A DENSE FOG ADVISORY MAY BE
NEEDED. LOW TEMPERATURES ARE EXPECTED TO BE IN THE MIDDLE TO
UPPER 50S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
THE SHORT TERM WILL BEGIN WITH WEAK HIGH PRESSURE ACROSS THE AREA
ON FRIDAY INTO FRIDAY NIGHT. BY SATURDAY INTO SATURDAY NIGHT...ALL
OF THE MODELS INDICATE THAT A FRONTAL BOUNDARY WILL BE APPROACHING
THE AREA FROM THE WEST. WITH FRONTAL BOUNDARY NEARLY PARALLEL TO
MID/UPPER FLOW...LOOKS LIKE THE FRONT WILL BE A SLOW MOVER INTO
THE REGION. WILL LIKELY HAVE TO WAIT FOR MORE VIGOROUS SHORTWAVE
ENERGY EXPECTED TO MOVE ACROSS THE MIDWEST/GREAT LAKES REGION BY
SUNDAY FOR FRONT TO MOVE INTO REGION. GUIDANCE AND LOCAL NUMBERS
SHOW WARM TEMPERATURES FOR THE PERIOD WITH TEMPERATURES RUNNING
NEARLY 10 DEGREES ABOVE NORMAL. WILL STAY NEAR A CONSENSUS OF THE
GUIDANCE AT THIS TIME THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
LATEST GFS CONTINUES TO SHOW AN APPROACHING COLD FRONT MOVING
INTO THE FORECAST AREA SUNDAY. CONTINUED WITH A CHANCE OF SHOWERS
SUNDAY/SUNDAY NIGHT. SREF ENSEMBLE GUIDANCE INDICATED THE BEST
CHANCE FOR RAIN TO BE SUNDAY AFTERNOON/NIGHT. TEMPERATURES WILL BE
TRICKY ON SUNDAY BASED ON THE ARRIVAL OF THE FRONTAL
BOUNDARY...BUT EXPECT COOLER TEMPERATURES BY MONDAY. TEMPERATURES
SHOULD BEGIN TO GRADUALLY RISE THROUGH THE REMAINDER OF THE LONG
TERM PERIOD...BUT REMAIN BELOW NORMAL. LOOKS LIKE THE AREA WILL
SEE THE COOLEST TEMPERATURES OF THE FALL PERIOD BY TUESDAY MORNING
AS MANY AREAS WILL FALL INTO THE UPPER 40S. TEMPERATURES WILL
GENERALLY MODERATE WEDNESDAY INTO THURSDAY. ANOTHER DRY COLD FRONT
APPROACHES FROM THE WEST LATE WEDNESDAY INTO EARLY THURSDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
THIN HIGH CLOUDS CONTINUES ACROSS THE AREA BUT WITH LIGHT
BOUNDARY LAYER WINDS...HIGH NEAR-SURFACE RELATIVE HUMIDITY...FOG
DEVELOPING AT AREA TERMINALS. RADIATION FOG SCHEME ALONG WITH
LATEST HRRR AND LAMP SUGGEST WIDESPREAD MVFR THROUGH 09Z THEN
LIFR/IFR AROUND 12Z POSSIBLE ESPECIALLY AT AGS/OGB. VISIBILITY MAY
STAY UP AT DNL...CROSS OVER TEMPERATURE LOWER THAN OTHER TERMINAL
SITES AND STRATUS NOT FORECAST.
EXTENDED AVIATION OUTLOOK...REDUCED VISIBILITY IN EARLY MORNING FOG
POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
07/77
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
324 AM CDT FRI OCT 5 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS THE COLD FRONT FROM LAKE HURON INTO TEXAS WITH
SFC WAVES IN SOUTHWEST MISSOURI AND NORTH TEXAS. A WEAK TROF RAN
FROM SOUTHERN LAKE MICHIGAN BACK TO THE KMCI AREA WITH ANOTHER FROM
LAKE SUPERIOR TO NEAR KHON. DEW POINTS ALONG AND SOUTH OF THE FRONT
WERE IN THE 50S AND 60S WITH 40S FROM LAKE MICHIGAN INTO KANSAS. DEW
POINTS IN THE 20S AND 30S WERE ACROSS MUCH OF THE PLAINS AND UPPER
MISSISSIPPI VALLEY.
&&
.SHORT TERM...TODAY AND TONIGHT...
RADAR RETURNS SHOW A WEAK AREA OF SPRINKLES/SHRA FROM SOUTH OF KIOWA
BACK THROUGH SOUTHERN IOWA. THIS PRECIPITATION APPEARS TO BE DUE TO
A MOISTURE AND THETA E GRADIENT PER RAP TRENDS AND THE OTHER MODELS.
THESE FEATURES WILL SLOWLY WEAKEN THE REMAINDER OF THE NIGHT INTO
THE MORNING COMMUTE. THE BETTER FORCING WITH THE MORE SUBSTANTIAL
SHRA ACTIVITY WILL CONTINUE ACROSS THE FAR SOUTHERN PARTS OF THE
CWFA THROUGH THE MORNING COMMUTE AS WELL. THERE MAY OR MAY NOT BE A
LULL IN THE PRECIPITATION DURING THE LATE MORNING HOURS WHILE THE
NEXT SHORTWAVE APPROACHES FROM THE PLAINS.
DURING THE AFTERNOON THIS SHORTWAVE MOVES ACROSS THE AREA. THERE IS
A COUPLED UPPER JET STRUCTURE WHICH WILL PROVIDE GENERAL SYNOPTIC
LIFT. THE SOUTH HALF OF THE CWFA WILL HAVE THE BETTER CHANCE AT
SEEING SHRA ACTIVITY.
TONIGHT...THERE MAY OR MAY NOT BE SOME LINGERING SPRINKLES IN THE
FAR EAST FOR A FEW HOURS. ALL MODELS SHOW A MOISTURE GRADIENT OVER
THE AREA WITH A DIFFUSE BUT WEAKENING THETA E GRADIENT. SO...HAVE
OPTED TO KEEP TONIGHT DRY.
THE LARGER CONCERN IS TEMPERATURES. ALL MODELS SHOW THE UPPER JET
OVER THE AREA WHICH COULD PROVIDE SOME CI/CS WHILE IN THE LOWER
LEVELS THE MODELS SUGGEST CLOUDS WITH THE INCREASING CYCLONIC FLOW
FROM THE SHORTWAVE DROPPING DOWN FROM THE NORTH. INTERESTINGLY...
THE MODELS ARE INDICATING SUBSIDENCE AND THUS POSSIBLE CLEAR SKIES.
CLOUD COVER WILL BE THE KEY TO HOW COLD IT GETS. IF THERE ARE CLOUDS
BUT THEY ARE THIN...THEN THE DRY GROUND MAY OFFSET THE CLOUDS AND
ALLOW TEMPERATURES TO DROP MORE THAN FCST. THE POTENTIAL DOES EXIST
FOR FREEZE HEADLINES FOR TONIGHT FROM ABOUT HWY 30 ON SOUTH. ..08..
.LONG TERM...SATURDAY THROUGH THURSDAY...
THIS EXTENDED PERIOD WILL MAINLY FOCUS ON TEMPERATURES WITH
ACTIVE...YET MAINLY DRY NORTH TO NORTHWEST FLOW. SATURDAY SHOULD BE
QUITE COLD AND WITH A STRATOCUMULUS DECK SPREADING OVER THE REGION
EARLY IN THE DAY...WE MAY BE HARD PRESSED TO REACH 50 IN MANY
LOCATIONS. FOR NOW...IT IS MOST LIKELY TO BE CLOUDY EARLY ENOUGH IN
THE DAY TO HOLD THE NORTH 1/3 TO THE UPPER 40S FOR HIGHS...WHILE THE
SOUTH COULD REACH THE LOWER 50S. THIS MOST CERTAINLY APPEARS TO BE
THE COLDEST DAY IN THIS CURRENT STRETCH OF CHILLY WEATHER. SATURDAY
NIGHT...ALL MODELS DECREASE SKY COVER FROM WEST TO EAST DURING THE
LATE AFTERNOON/EARLY EVENING HOURS. COMBINED WITH LIGHT WINDS AND
LINGERING VERY COLD AIRMASS ALOFT...WE SHOULD DROP TO LOWS IN THE
20S OVER MOST OF THE CWA...WITH SOME LOWER TO MID 20S IN FAVORED
LOWER LYING AREAS. SHOULD TONIGHT NOT RESULT IN FREEZE
CONDITIONS...HEADLINES SHOULD BE REQUIRED FOR SATURDAY NIGHT.
SUNDAY BEGINS SEVERAL DAYS OF MODERATION TO MORE COMFORTABLE
WEATHER...WITH HIGHS REACHING THE MID 50S WITH PLENTY OF SUN...THEN
AFTER A COOL NIGHT IN THE 30S...MONDAY SHOULD SEE A RETURN TO THE
LOWER 60S. UNFORTUNATELY...THIS WARMTH WILL ARRIVE WITH STRONGER
WINDS...THUS SENSIBLE WEATHER WILL BE PRETTY BRISK OUT THERE.
TUESDAY...A PASSING WAVE IN NORTHWEST FLOW SHOULD KEEP US MILD
AGAIN...WITH A CHANCE FOR RAIN SHOWERS. MODELS INDICATE THAT GOOD
MOISTURE MAY BE NEAR OR JUST PASS SOUTH OF THE CWA. SO...WHILE
CHANCE ARE INCREASED FROM PRIOR FORECASTS...THE AMOUNTS MAY BE QUITE
LIGHT. AFTER TUESDAY...MORE DRY WEATHER WITH CANADIAN HIGH PRESSURE
IS IN STORE FOR WEDNESDAY AND THURSDAY. LOWS IN THE 30S AND HIGHS IN
THE 50S WED/60S THU ARE EXPECTED.
ERVIN
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THE NEXT 24 HOURS WITH
SPOTTY SHOWERS FRONTAL CLOUD BAND HAS EXITED THE
CWA WHILE MID AND HIGH LEVEL CLOUDS FROM THE FIRST OF TWO
SHORTWAVE TROUGHS ENTER THE AREA. THE FIRST TROUGH WILL PASS THROUGH
EARLY TODAY AND THE SECOND THIS AFTERNOON...AND BOTH WILL PRODUCE
INTERMITTENT BOUTS OF LIGHT RAIN...PRIMARILY AT KBRL. OTHER TAF
SITES SHOULD REMAIN DRY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
08/ERVIN/08
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
356 AM EDT FRI OCT 5 2012
.SHORT TERM...TODAY AND TONIGHT
NOW THAT THE SURFACE COLD FRONT HAS CLEARED THE AREA, MODERATE COLD
ADVECTION HAS BEGUN AND IS FORECAST TO CONTINUE WITH 850MB
TEMPERATURES FALLING TO SLIGHTLY BELOW ZERO BY 06Z TONIGHT. THE MOST
NOTEWORTHY CHANGE MADE TO TODAY`S FORECAST PACKAGE WAS TO TREND
TODAY`S HIGH TEMPERATURES DOWNWARD A COUPLE OF DEGREES. ALL
LOCATIONS STAND A GOOD CHANCE TO REMAIN IN THE 50S FOR THE BALANCE
OF THE DAY AS EARLY OCTOBER DIURNAL HEATING WILL HAVE TO CONTEND
WITH NOT ONLY WITH ONGOING COLD ADVECTION, BUT ALSO WIDESPREAD MID
AND UPPER CLOUDS. IN ADDITION, UPSTREAM LOCATIONS THAT SPENT THE
DAYTIME HOURS THURSDAY IN THE POST-FRONTAL ENVIRONMENT GENERALLY
ROSE INTO THE LOW 50S. AFTER GIVING CONSIDERATION TO THE HEAT
CONTRIBUTION FROM LAKE MICHIGAN, WHERE LAKE SFC TEMPS REMAIN IN THE
LOW 60S, HIGHS FOR TODAY WERE GIVEN A DOWNWARD ADJUSTMENT INTO THE
55-58 DEGREE RANGE. A FEW 60S STILL CAN`T BE RULED OUT SHOULD CLOUDS
BREAK DURING PEAK HEATING, MOST LIKELY NORTH OF M-59.
THE OTHER FORECAST ISSUE FOR TODAY IS THE PLACEMENT AND DURATION OF
A BAND OF SHOWERS THAT IS CURRENTLY TAKING SHAPE OVER MO/IL. WATER
VAPOR IMAGERY SHOWS AN ENERGETIC ZONAL FLOW ACROSS THE CENTRAL U.S.
WITH EMBEDDED LOW AMPLITUDE SHORTWAVES PROPAGATING ACROSS THE PLAINS
STATES. SHOWER COVERAGE IS EXPANDING AHEAD OF THIS ENERGY AND IN
ASSOCIATION WITH A DEVELOPING FGEN RESPONSE UNDER THE RIGHT ENTRANCE
OF A STRENGTHENING 90KT JET STREAK. THE 00Z GUIDANCE, IN PARTICULAR
THE NAM AND RECENT 3-KM HRRR SIMULATIONS, LOOK SOLID IN THEIR
REPRESENTATION OF THE DEVELOPING FRONTAL CIRCULATION AND ASSOCIATED
PRECIPITATION COVERAGE. FOR NOW, THE ONLY COMPLAINT IS THAT THE
RESPONSE WITHIN THE LOW STATIC STABILITY ENVIRONMENT LEADING THE
ARRIVAL OF THE JET CORE LOOKS HEALTHY, SO LEANED TOWARD AN EARLIER
12-13Z ARRIVAL TIME FOR SOUTHERN AREAS. THE NORTH SIDE OF THE PRECIP
SHIELD WILL INITIALLY CARRY THE SHARP CUTOFF EVIDENT ON THE REGIONAL
RADAR MOSAIC INTO THE AREA, CASTING SOME UNCERTAINTY ON ITS
NORTHWARD EXTENT AS IT STRADDLES THE METRO DETROIT AREA INTO THE
AFTERNOON. HOWEVER, ADDITIONAL NORTHWARD EXPANSION SEEMS PROBABLE
THIS AFTERNOON AS THE POTENT SHORTWAVE ENERGY OVER ID/WY AT 07Z
ACCELERATES TOWARD THE AREA LATER TODAY. LAKE CLOUDS WILL THEN BUILD
INTO THE AREA LATE TONIGHT COINCIDENT WITH THE APPROACH OF THE UPPER
TROUGH AXIS AND H85-SFC DELTA T VALUES PLUMMETING TO 20C OVER LM.
THE STAGE WILL THEN BE SET FOR A COLD START TO SATURDAY MORNING AS
LOW TEMPS DIP INTO THE MID TO UPPER 30S UNDERNEATH INCREASING
BOUNDARY LAYER SKY COVER.
&&
.LONG TERM...SATURDAY THROUGH THURSDAY
AS UPPER LOW SHIFTS JUST NORTH OF LAKE SUPERIOR IS PULLED NORTHEAST
INTO BROADER HUDSON BAY VORTEX...UPPER TROUGH AXIS WILL SWING ACROSS
LOWER MICHIGAN AND BRING A SECOND SHOT OF COLD AIR INTO THE AREA ON
SATURDAY. WITH H85 TEMPERATURES FALLING SOLIDLY BELOW 0C...EXPECT
HIGH TEMPERATURES TO REMAIN BETWEEN 50 AND 55. WHILE BEST LIFT AND
FORCING WITH THE VORTICITY CENTER ALONG THIS TROUGH WILL REMAIN TO
THE NORTH OF THE AREA...THERE WILL BE A SMALL CHANCE OF SHOWERS IN
THE 20-30% RANGE AS WRAPAROUND MOISTURE BRUSHES THE AREA AND LAKE
EFFECT ACTIVITY BEGINS TO EXPAND IN THE COLDER AIR.
AFTER ANOTHER DAY WITH HIGH TEMPERATURES AOB 55F ON SUNDAY (WITH
EARLY MORNING TEMPERATURES MOST LIKELY REACHING FREEZING IN SOME
LOCATIONS)...THE NEXT STRONG SHORTWAVE PIVOTING THROUGH THE NORTHERN
GREAT LAKES AROUND THE HUDSON VORTEX WILL BRING A MODERATING TREND
IN THE MONDAY AND TUESDAY TIME FRAME AS SOUTHWEST FLOW BECOMES
ESTABLISHED IN ADVANCE OF THE NEXT STRONG COLD FRONT WHICH WILL
SHIFT INTO THE AREA AS THIS SECOND NORTHERN STREAM STORM SYSTEM
WRAPS NORTHEAST INTO THE AFOREMENTIONED VORTEX. TEMPERATURES WILL
CLIMB WELL INTO THE 50S ON MONDAY AND TO 60 OR BETTER ON TUESDAY AS
THE ARRIVAL OF THIS COLD FRONT IS DELAYED SLIGHTLY AS LOW PRESSURE
RIPPLES UP ALONG IT.
THIS SOUTHERN STREAM LOW PRESSURE WILL BRING THE BEST CHANCE OF
RAINFALL IN THE EXTENDED PORTION OF THE FORECAST AS STRONG FORCING
SHIFTS THROUGH THE AREA WITH THIS PASSAGE OF THIS SYSTEM TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING...WITH ONLY MINOR LAKE EFFECT
ACTIVITY EXPECTED LATER WEDNESDAY INTO THURSDAY SOUTHEAST OF LAKE
HURON.
TEMPERATURES WILL COOL BACK INTO THE MID 50S ON WEDNESDAY...BUT WITH
NORTHERN STREAM SHORTWAVE TAKING A WESTERLY TRACK NORTH OF THE GREAT
LAKES...THE COLDEST AIR WITH THIS SYSTEM WILL REMAIN OVER CANADA AND
EXPECT TEMPERATURES TO REBOUND TO THE UPPER 50S TO AROUND 60 BY
THURSDAY.
&&
.MARINE...
A FRESH WEST-SOUTHWEST BREEZE WILL GUST INTO THE 25 TO 30 KNOT RANGE
TODAY AS A COOL AND UNSTABLE AIRMASS OVERSPREADS AREA WATERS. A FEW
GUSTS TO LOW END GALE FORCE WILL BE POSSIBLE FROM OUTER SAGINAW BAY
INTO CENTRAL LAKE HURON THIS AFTERNOON...BUT NO ORGANIZED OR
WIDESPREAD GALES ARE EXPECTED. WINDS WILL GRADUALLY EASE BY LATE
FRIDAY NIGHT BUT WAVES WILL REMAIN REMAIN ELEVATED INTO SATURDAY
MORNING. ALL SMALL CRAFT ADVISORIES THEREFORE REMAIN IN EFFECT FOR
SAGINAW BAY AND THE NEARSHORE FROM PORT AUSTIN TO HARBOR BEACH UNTIL
SATURDAY MORNING. A RENEWED SURGE OF GUSTY WINDS WILL DEVELOP AHEAD
OF ANOTHER PUSH OF COLD AIR ON SATURDAY. A BRIEF REPRIEVE CAN BE
EXPECTED ON SUNDAY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE
AREA...BUT UNSETTLED CONDITIONS WILL QUICKLY REDEVELOP AS THE
SURFACE PRESSURE GRADIENT STRENGTHENS EARLY NEXT WEEK. SOUTH WINDS
WILL INCREASE TO 20 TO 25 KNOTS BY LATE MONDAY.
&&
.AVIATION...ISSUED 1235 AM EDT FRI OCT 5 2012
//DISCUSSION...
COLD FRONTAL BOUNDARY RAPIDLY SHIFTING THROUGH THE AREA EARLY THIS
MORNING. SOME EVIDENCE OF LOWER MVFR CIGS IN LIGHT RAIN SHOWERS
NOW EMERGING ALONG THE FRONTAL SLOPE...BUT COVERAGE REMAINS TOO
SPOTTY TO DEFINE A SPECIFIC MENTION OF MVFR RESTRICTIONS LOCALLY
AT THIS POINT. BRIEF INCREASE IN WESTERLY WINDS IMMEDIATELY BEHIND
THE FRONT BEFORE EASING BACK INTO THE 10-12KT RANGE. INCREASING
MID LEVEL FORCING NORTH OF THIS FRONT WILL BRING A RENEWED CHANCE
FOR SHOWERS IN A LOWER CEILING ACROSS MAINLY THE DETROIT AREA BY
FRIDAY AFTERNOON.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILING INTERMITTENTLY FALLING 5000 FEET EARLY
THIS MORNING.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
PORT AUSTIN TO HARBOR BEACH...FROM 8 AM FRIDAY TO 8 AM
SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...JVC
LONG TERM....DG
MARINE.......JVC
AVIATION.....JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
141 AM EDT FRI OCT 5 2012
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 423 PM EDT THU OCT 4 2012
WV LOOP AND RUC ANALYSIS SHOW NEGATIVE TILTED SHORTWAVE TROUGH OVER
NORTHERN MINNESOTA THIS AFTN WITH ASSOCIATED SFC LOW IN THE VCNTY OF
KINL. COLD FRONT IS IN PROCESS OF MAKING ITS WAY ACROSS UPR
MICHIGAN...BUT MUCH COLDER AIR IS LAGGING BEHIND OVER NORTHERN
MINNESOTA. HAVE SEEN ISOLD SHRA FORM THIS AFTN WITH EVEN TSRA. MAIN
AREA WAS ON KEWEENAW BUT JUST WITHIN LAST 1 HR ANOTHER LINE OF SHRA
HAS FORMED OVER EASTERN LK SUPERIOR/FAR NORTHEAST CWA. DEEP DRYING
WRAPPING IN ON SOUTHERN EDGE OF SHORTWAVE TROUGH IS STEEPENING MID
LEVEL LAPSE RATES. MOST OF SHRA/TSRA KICKED ON WITHIN THE BETTER
LR/S AND ALSO ON LEADING EDGE OF H85 FRONTOGENESIS. OTHERWISE ONCE
PESKY FOG HELPED OUT BY MOISTURE OFF LK MICHIGAN BURNED OFF...IT HAS
BECOME NICE DAY WITH HIGHS TOPPING OUT IN THE 60S AND EVEN SOME
LOWER 70S. THAT WILL BE LAST 70 DEGREES FOR POSSIBLY THIS FALL
THOUGH AS BIG CHANGES ARE COMING IN ONCE THE LOW OVER MINNESOTA
MOVES TO NORTHERN LK SUPERIOR AND COLDER AIR PLOWS INTO THE REGION.
THROUGH FRIDAY...DO NOT EXPECT ANY BIG SNOW ACCUMS. WIDESPREAD SNOW
ON CYCLONIC SIDE OF SHORTWAVE TROUGH AND IN MOIST/CYCLONIC FLOW
BEHIND SFC LOW NEVER REALLY MAKES IT INTO CWA...INSTEAD LIFTING MORE
NORTHEAST INTO ONTARIO. INSTEAD...NORTHWEST CWA GRADUALLY GETS INTO
A REGIME WITH PLENTIFUL LOW-LEVEL MOISTURE BLO 10KFT AND WSW BLYR
WINDS TURNING MORE WESTERLY WITH TIME. SOUNDINGS INDICATE TEMPS IN
MOIST LAYER ARE WARMER THAN -8C UNTIL THE DAYTIME ON FRIDAY. UPSHOT
IS THAT INITIAL PRECIP TONIGHT INTO FRIDAY MORNING FOR NW CWA WILL
BE MAINLY LIGHT RAIN WITH PERHAPS REALLY SMALL SNOW FLAKES MIXING IN
AT TIMES LATER TONIGHT. AFTER EARLY EVENING POPS EAST...RESTRICTED
POPS FOR LAKE EFFECT/CYCLONIC FLOW MOISTURE TO KEWEENAW OVERNIGHT
TONIGHT AS REST OF AREA STAYS IN UNFAVORABLE WSW WINDS IN LOW-LEVELS.
WINDS IN BLYR LATE TONIGHT PUSH TOWARD 30 MPH SO EXPECT WINDS NW CWA
TO INCREASE LATE. SHOULD BE FAIRLY QUIET OVER REST OF CWA. SKIES MAY
EVEN CLEAR OUT SOME IN THE CNTRL AND EAST OVERNIGHT FOR A TIME.
A RATHER MISERABLE DAY IS IN STORE FOR KEWEENAW ON FRIDAY. SOUNDINGS
SHOW INCREASING DEPTH TO MOISTURE WITH MOISTURE PUSHING COLDER THAN
-10C BY AFTN SO SHOULD SEE MORE AND MORE SNOW MIX WITH RAIN THROUGH
THE DAY. BLYR TEMPS REMAIN WARM IN THE UPR 30S AND LOWER 40S...SO
EVEN IF PRECIP CHANGES TO MOSTLY SNOW DURING THE DAY /WOULD OCCUR
BASED ON WBZERO HEIGHTS FALLING WELL BLO 1000 FT AGL/ LITTLE OR NO
SNOW ACCUM SHOULD OCCUR DURING THE DAY. BEST CHANCE FOR SEEING SNOW
AS ONLY PTYPE WILL BE ON THE HIGHEST TERRAIN OF THE NW CWA. SIMILAR
TO TONIGHT...SHOULD BE PRETTY QUIET MOST OTHER AREAS ON FRIDAY
MORNING THOUGH A BIT BREEZY. BY FAR...STRONGEST WINDS WILL BE FOUND
ON THE KEWEENAW WITH FAVORED WESTERLY WINDS. MIXED LAYER WINDS
EASILY TOP OUT OVER 35 KTS AND TOP OF MIXED LAYER WINDS FROM
SOUNDINGS SUPPORT GUSTS PUSHING WELL OVER 40 KTS. WINDS ARE ALSO
STRONG ALONG LAKE SUPERIOR FROM IWD TO ONTONAGON. FAVORED WEST WIND
DIRECTION AND SUCH STRONG WINDS IN MIXED LAYER IN FACE OF STRONG
COLD AIR ADVECTION SUPPORTS FREQUENT GUSTS ON FRIDAY OVER HIGHER
TERRAIN OF KEWEENAW PENINSULA REACHING WIND ADVY LEVEL /39 KT OR 45
MPH/. WIND ADVY WAS ISSUED FOR KEWEENAW. FOR THOSE OTHER AREAS NEAR
LK SUPERIOR ADVY LEVEL WIND GUSTS SHOULD BE NOT AS FREQUENT...SO DID
NOT INCLUDE THOSE AREAS IN ADVY AT THIS TIME.
BY MID-LATE AFTN ON FRIDAY...925MB-850MB WINDS VEER MORE WNW WHICH
SHOULD BRING MORE OF CWA INTO CYCLONIC LOW-LEVEL MOIST FLOW. EXPECT
WX REGIME OVER KEWEENAW TO BEGIN TO SHIFT TOWARD HIGHER TERRAIN OF
ALL WESTERN AND POSSIBLE NCNTRL CWA BY 21Z. TEMPS MAY ALSO TRY TO
FALL OFF FOR THESE AREAS AS WELL. AGAIN...LIKE THE KEWEENAW EVEN
WITH MAINLY SNOW VERSUS RAIN...WARMER BLYR TEMPS AND MINIMAL
STRONGER LAKE EFFECT CONVECTION SHOULD PROHIBIT MUCH IN WAY OF SNOW
ACCUM. BETTER CHANCE FOR SNOW ACCUMS FOR THE CWA WILL OCCUR MORE ON
FRIDAY NIGHT WHICH IS NOW ADDRESSED IN THE LONGER TERM DISCUSSION.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 423 PM EDT THU OCT 4 2012
NAM SHOWS A BROAD 500 MB TROUGH ACROSS THE CENTRAL U.S. WITH A RIDGE
OFF THE PACIFIC NW AND A CLOSED LOW OFF THE CA COAST IN A REX BLOCK
PATTERN WITH A RIDGE OFF THE EAST COAST 00Z SAT. PATTERN DOES NOT
CHANGE MUCH WITH A SHORTWAVE OVER THE NORTHERN PLAINS ROTATING
AROUND THE TROUGH AND INTO THE LOWER GREAT LAKES ON SUNDAY.
BASICALLY...WILL NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.
SINCE THIS IS AN EARLY SEASON SNOW...LOT OF THE TOOLS WILL NOT WORK
USING THICKNESSES FOR DETERMINING SNOW AND PRETTY MUCH KEPT WHAT WAS
ALREADY IN THERE WHICH IS SNOW IN THE HIGHER TERRAIN AND RAIN IN THE
LOWER TERRAIN AND EASTERN CWA. DID LOWER SNOW RATIOS THOUGH AS
FEELING IS THAT THE SNOW FLAKE SIZE WILL BE SMALL AND LOWER THAN A
10 TO 1 RATIO WILL WORK. THIS STILL GIVES ME 1-3 INCHES IN THE
HIGHER TERRAIN FOR FRI NIGHT THROUGH SAT EVENING. IT WILL BE COLD
ENOUGH FOR LAKE EFFECT PCPN AND LOWERED THE LAKE TEMPERATURES TO 10C
TO 12C FOR FRI NIGHT AND SAT AS THINKING IS THE LAKE WILL START TO
GET TURNED OVER AND WATER TEMPERATURES WILL COOL OFF FROM 12C TO 15C
THAT IT IS NOW. 850 MB TEMPERATURES COOL TO AROUND -6C BY 12Z SAT
AND THAT IS ENOUGH LAKE EFFECT DELTA-T FOR LAKE EFFECT. BY
SUNDAY...WINDS SWITCH TO THE SW AND WITH WARM AIR ADVECTION COMING
IN...THIS WILL PUSH THE LAKE EFFECT PCPN OFFSHORE OF THE U.P.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH ACROSS
THE CENTRAL AND EASTERN U.S. WITH A RIDGE OFF THE PACIFIC NW AND A
CLOSED LOW OFF THE CA COAST IN A REX BLOCK PATTERN 12Z MONDAY. THERE
IS A SHORTWAVE ACROSS SOUTH CENTRAL CANADA THAT IS POISED TO DROP
INTO THE UPPER GREAT LAKES WITH AN ALBERTA CLIPPER SYSTEM THAT MOVES
THROUGH MON NIGHT INTO TUE. THE TROUGH OVER THE CENTRAL AND EASTERN
U.S. STAYS ANCHORED OVER THE UPPER GREAT LAKES INTO WED. ANOTHER
CLIPPER TYPE SYSTEM LOOKS TO AFFECT THE AREA ON THU. IT LOOKS TO
STAY COLDER THAN NORMAL THROUGH THE EXTENDED PERIOD WITH ACTIVE
WEATHER. KEPT MIXTURE OF RAIN AND SNOW IN FOR LATE TUE NIGHT INTO
WED MORNING WITH NEXT COLD AIR WAVE THAT COMES THROUGH. DID NOT MAKE
TOO MANY CHANGES TO THE GOING FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 139 AM EDT FRI OCT 5 2012
UPPER MI WILL BE UNDER THE CIRCULATION OF A LOW PRES SYSTEM MOVING
ACROSS NRN ONTARIO TODAY. INITIALLY...CONDITIONS WILL BE VFR AT
KIWD/KCMX/KSAW...BUT AS COLDER AIR INCREASES OVERLAKE INSTABILITY
AND MOISTURE WRAPS AROUND THE LOW INTO THE AREA...EXPECT CIGS TO BE
MVFR AT KCMX BY FCST ISSUANCE TIME AND AT KIWD BEFORE DAYBREAK. THE
COLDER AIR WILL ALSO LEAD TO LAKE ENHANCED RAIN/SNOW/IFR CONDITIONS
DEVELOPING AT KCMX EARLY THIS MORNING AND THEN CONTINUING THRU THE
DAY. WINDS SHOULD VEER ENOUGH TO BRING LAKE EFFECT PCPN INTO KIWD
THIS AFTN. SFC TROF DROPPING ACROSS THE LAKE LATER THIS AFTN/EVENING
SHOULD BRING HEAVIER -SHSN/IFR CONDITIONS TO KIWD THIS EVENING.
MEANWHILE...AFTER TROF PASSES...CONDITIONS SHOULD IMPROVE TO MVFR AT
KCMX. AT KSAW...W DOWNSLOPING WINDS THRU THE PERIOD SHOULD RESULT IN
VFR CONDITIONS PREVAILING WITH NO PCPN. SFC TROF/-SHSN SHOULD REACH
KSAW AROUND THE END OF THIS FCST PERIOD. WITH A TIGHT PRES
GRADIENT...WINDS WILL BE STRONG WITH GUSTS AOA 30KT THRU TODAY.
STRONGEST WINDS...GUSTING TO 40KT OR SO...WILL BE AT KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT THU OCT 4 2012
AN INTENSIFYING LOW PRESSURE SYSTEM WILL MOVE NORTH-NORTHEAST FROM
CENTRAL MINNESOTA TO THE U.S./CANADIAN BORDER BY THIS
AFTERNOON...BEFORE BEING LOCATED JUST NORTH NORTHWEST OF LAKE
SUPERIOR BY LATE TONIGHT. THIS WILL LEAD TO INCREASING SOUTHWESTERLY
WINDS ACROSS THE LAKE THIS AFTERNOON WITH GALE FORCE GUSTS OF
35-45KTS EXPECTED OVER MAINLY WRN LAKE SUPERIOR THIS
AFTERNOON/EVENING...INCREASING TO 45KTS TONIGHT INTO EARLY FRIDAY.
THE LOW WILL SHIFT NORTHEAST ON FRIDAY...BUT WILL KEEP A SFC TROUGH
OVER LAKE SUPERIOR THROUGH FRIDAY NIGHT. AS THIS SFC TROUGH SLOWLY
SLIDES SE ACROSS LAKE SUPERIOR...EXPECT WINDS TO SHIFT TO THE
NORTHWEST AND GUSTS UP TO 35KTS AT TIMES. A HIGH PRESSURE RIDGE WILL
BUILD OVER THE UPPER GREAT LAKES REGION ON SATURDAY AND
SUNDAY...LOWERING WINDS BELOW 25KTS. WINDS COME UP TO 30 KNOTS FOR
MON NIGHT AND TUE WITH NEXT CLIPPER TYPE SYSTEM BRINGING IN SOME
COLDER AIR. GETS REAL CLOSE TO A GALE THEN WITH A TIGHTER PRESSURE
GRADIENT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING FROM 6 AM THIS MORNING TO 10 AM EDT SATURDAY FOR
LSZ267.
GALE WARNING UNTIL 10 AM EDT SATURDAY FOR LSZ264>266.
GALE WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR LSZ162-
240>247.
GALE WARNING UNTIL 6 AM EDT SATURDAY FOR LSZ263.
GALE WARNING FROM 6 AM THIS MORNING TO 8 PM EDT THIS EVENING FOR
LSZ248.
LAKE MICHIGAN...
GALE WARNING UNTIL 2 PM EDT THIS AFTERNOON FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLA
LONG TERM...07
AVIATION...ROLFSON
MARINE...07
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1200 AM EDT FRI OCT 5 2012
.SYNOPSIS...
ISSUED AT 354 PM EDT THU OCT 4 2012
A STRONG COLD FRONT WILL CROSS THE AREA THIS EVENING WITH SHOWERS
AND SCATTERED THUNDERSTORMS. SKIES WILL CLEAR LATE TONIGHT AND IT
WILL TURN COLDER. EXPECT MOSTLY SUNNY SKIES FRIDAY WITH HIGHS ONLY
IN THE 50S. LAKE EFFECT RAIN SHOWERS ARE EXPECTED SATURDAY INTO
SUNDAY WITH HIGHS MOSTLY IN THE 4OS.
&&
.UPDATE...
ISSUED AT 805 PM EDT THU OCT 4 2012
WE HAVE ISSUED AN UPDATE THIS EVENING TO FRESHEN UP THE FCST BASED
ON CURRENT TRENDS. THE TREND IS FOR THE RAIN TO MOVE THROUGH A
LITTLE QUICKER THAN PREVIOUSLY EXPECTED...ESPECIALLY UP NORTH WHERE THE
RAIN IS LIKELY DONE FOR THIS PORTION OF THE EVENT.
RAIN IS STILL MOVING INTO THE SRN PORTIONS OF THE AREA AS THE
FRONT PRESSES EAST. THERE HAS BEEN A COUPLE OF LIGHTNING STRIKES
OBSERVED...SO WE WILL CONTINUE THE ISOLATED MENTION OF THUNDER.
THE SRN PORTION OF THE CWFA WILL SEE RAIN HOLD OVER A LITTLE
LONGER AS ANOTHER WAVE OF RAINFALL COMING IN FROM THE SW WILL TAKE
A FEW HOURS TO PASS BY THE AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 354 PM EDT THU OCT 4 2012
THE MAIN ISSUE IS THE CONVECTIVE LINE OVER WISCONSIN HEADING
TOWARD SOUTHWEST LOWER MICHIGAN AS I WRITE THIS. BEYOND THAT THERE
IS THE ISSUE OF LAKE EFFECT RAIN SHOWERS OVER THE WEEKEND.
THE COMBINATION OF JET ASSISTED LIFT AND A DEVELOPING LOW LEVEL
JET WILL AID THE DEVELOPMENT OF A LINE OF SHOWERS THAT AT 3 PM WAS
OVER EASTERN WISCONSIN. AS THIS LINE CROSSES LAKE MICHIGAN I
EXPECT THUNDERSTORMS TO DEVELOP WITHIN THAT LINE. AIDING THAT IS
A SURGE OF HIGHER SURFACE DEW POINTS JUST AHEAD OF THE COLD FRONT.
THE 1000 TO 850 MB MOISTURE TRANSPORT VECTORS INCREASE SIGNIFICANTLY
AS THE FRONT CROSSES LAKE MICHIGAN. THE HRRR RUC IS DOING REASONABLY
WELL WITH THE CONVECTION ON THE COLD FRONT SO FAR THIS AFTERNOON.
SO...BASED ON OUR TIMING TOOL...THE TIMING IN THE HRRR RUC AND RELATED
TOOLS I EXPECT A NEARLY SOLID LINE OF SHOWERS AND ISOLATED STORMS
TO CROSS THE CWA BETWEEN 6 PM AND 11 PM THIS EVENING. I DO NOT
EXPECT SEVERE STORMS AS THE CAPES ARE NOT IMPRESSIVE BUT THERE IS
30 - 40 KNOTS OF DEEP LAYER SHEAR TO WORK WITH. THERE IS ALSO 40
TO 50 KNOTS AS CLOSE TO THE GROUND AS 5000 FT AGL AS THIS LINE
MOVES CROSS THE CWA. SO EXPECT GUSTY WINDS WITH THE SHOWERS.
ONCE THIS FEATURE MOVES EAST THE STRONG COLD ADVECTION BEHIND THE
FRONT WILL RESULT IN CONSIDERABLE SUBSIDENCE SO EXPECT CLEARING
SKIES LATER TONIGHT.
ANOTHER JET SEGMENT ROTATING THROUGH THE UPPER TROUGH WILL INDUCE
A WAVE ON THE FRONT FRIDAY INTO SATURDAY. AT THIS POINT IT SEEMS
THE RAIN FROM THAT WILL MOSTLY STAY SOUTH OF THE CWA. IT COULD
IMPACT AREAS SOUTH OF I-69 FRIDAY INTO FRIDAY EVENING EVEN SO. I
HAVE LOW CHANCE POPS FOR THAT.
THE SHORTWAVE TROUGH WITH THE DEEP COLD AIR ROTATES THROUGH THE
CWA SATURDAY. THAT WILL RESULT IN LAKE EFFECT RAIN SHOWERS. THANKS
TO A NORTH NORTHWEST WIND IN THE BOUNDARY LAYER I EXPECT MOST OF
THE SIGNIFICANT SHOWERS TO BE CLOSE TO LAKE SHORE. EVEN SO THE AIR
IS UNSTABLE ENOUGH THAT ALL AREAS SHOULD SEE SOME SHOWERS IN THE
AFTERNOON. SATURDAY NIGHT THOSE SHOWERS WILL CONTINUE NEAR THE
LAKE SHORE BUT SOME CLEARING IS POSSIBLE INLAND. COLD BE A FREEZE
EARLY SUNDAY MORNING NORTH AND EAST OF GRR. WE WILL HAVE TO WATCH
THAT FOR A POSSIBLE FREEZE WARNING.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 354 PM EDT THU OCT 4 2012
STILL EXPECTING SOME WEAK LAKE EFFECT RAIN SHOWERS INTO SUNDAY...
HOWEVER SURFACE RIDGING SHOULD BE BREAKING MUCH OF IT UP THROUGH THE
DAY. FROST POTENTIAL LOOKS RATHER GOOD INTO SUNDAY NIGHT AS SKIES
CLEAR. WE WILL HAVE TO SEE HOW MUCH MIXING REMAINS OVER THE
REGION...WHICH COULD LESSEN THE IMPACTS.
THE NEXT RAIN MAKER WILL COME IN THE FORM OF ANOTHER COLD FRONT
EXPECTED LATE TUESDAY INTO WEDNESDAY. COULD BE POCKETS OF STEADIER
RAINS AS THIS FRONT LOOKS MUCH LIKE THIS EVENING/S FRONT. HAVE LEFT
THUNDER OUT HOWEVER AS THE TIMING OF THE FROPA SHOULD BE LATE
TUESDAY NIGHT.
THE CHILLY AIR WILL SLOWLY LOSE IT/S GRIP ON THE REGION INTO EARLY
NEXT WEEK. H8 TEMPS BELOW 0C MOVE EAST OF THE AREA BY MONDAY
AFTERNOON SO A SLIGHTLY WARMING TREND IS EXPECTED WITH UPPER 50S AND
LOWER 60S FOR MONDAY AND TUESDAY. ANOTHER SHOT OF COOLER AIR IS
EXPECTED BEHIND THE TUESDAY NIGHT FRONT...HOWEVER THIS LOOKS TO BE A
QUICKER SHOT...WITH H8 TEMPS ALREADY WARMING BY THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1200 PM EDT FRI OCT 5 2012
EXPECT MOSTLY VFR TONIGHT ALTHOUGH SOME SHOWERS WILL BRING PATCHY
MVFR THROUGH 09Z ESPECIALLY AT AZO AND BTL. SOUTHWEST WINDS WILL
GUST TO NEAR 20 KNOTS AT TIMES BEFORE DECREASING LATE TONIGHT.
&&
.MARINE...
ISSUED AT 354 PM EDT THU OCT 4 2012
I EXTENDED THE SMALL CRAFT ADVISORY INTO SATURDAY NIGHT SINCE WAVE
HEIGHTS ARE NOT EXPECTED TO SUBSIDE BELOW 4 FEET UNTIL EARLY
SUNDAY MORNING. THE EXPERIMENTAL GREAT LAKES WATER SPOUT FORECAST
SHOWS THE BEST SHOT OF WATER SPOUTS AS BEING SATURDAY AS THE DEEPER
COLD AIR MOVES IN. I PUT WATER SPOUTS IN THE NEAR SHORE DURING
THAT TIME.
THE HRRR SUGGEST POSSIBLE NEAR GALE WINDS WITH THE FRONT THIS
EVENING THAT WILL HAVE TO BE WATCHED TOO.
&&
.HYDROLOGY...
ISSUED AT 354 PM EDT THU OCT 4 2012
RAINFALL WILL BE LIMITED AT BEST OVER THE NEXT WEEK SO EVEN WITH
THE RAINS LAST NIGHT I DO NOT SEE ANY SIGNIFICANT FLOODING ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...NJJ
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...OSTUNO
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS TULSA OK
1151 PM CDT THU OCT 4 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 6Z TAFS... RAIN SHOWERS AND SCATTERED THUNDERSTORMS ARE
EXPECTED TO AFFECT MUCH OF THE AREA OVERNIGHT. CEILINGS ARE
EXPECTED TO FALL TO MVFR LEVELS... WITH LIGHT DRIZZLE PERSISTING
THROUGHOUT MUCH OF THE DAY FRIDAY. CONDITIONS WILL SLOWLY IMPROVE
FROM THE NORTH THROUGH THE AFTERNOON AND EVENING.
&&
.PREV DISCUSSION... /ISSUED 756 PM CDT THU OCT 4 2012/
DISCUSSION...
SHALLOW FRONT CONTINUES TO WEDGE ITS WAY SOUTH...LOCATED FROM
GROVE TO ADA AT 00Z. THE SOUTHWARD PUSH SHOULD HALT BY LATE
TONIGHT IN THE ELEVATED TERRAIN OF SOUTHEAST OK AND NORTHWEST AR.
THE LATEST DATA CONTINUES TO INDICATE SOME ELEVATED SHOWER AND
STORM DVLPMT LATER TONIGHT MAINLY ACROSS NORTHEAST OK.
HOWEVER...THE LATEST HRRR ISN`T VERY AGGRESSIVE WITH DVLPMT
TONIGHT...WHILE OTHER MODELS SUCH AS THE GFS AND ECMWF SHOW THE
HEAVIER QPF NORTH OF THE KANSAS BORDER. THUS...I HAVE TRENDED POPS
LOWER AND HAVE REDUCED THUNDER CHANCES TO JUST SCT FOR TONIGHT.
UPDATED TEXT PRODUCTS SENT.
LACY
PREV DISCUSSION... /ISSUED 624 PM CDT THU OCT 4 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 0Z TAFS... A SLOW MOVING COLD FRONT/WIND SHIFT IS CURRENTLY
WORKING ITS WAY SOUTHWARD ACROSS THE REGION. NORTHEAST OKLAHOMA
SITES HAVE ALREADY SHIFTED TO THE NORTH. KMLC AND ARKANSAS SITES
WILL FOLLOW BY 6Z. ARKANSAS SITES WILL HAVE THE BEST POSSIBILITY
FOR THUNDERSTORMS EARLY FRIDAY LASTING INTO MID MORNING.
WIDESPREAD MVFR CEILINGS ARE EXPECTED IN THE WAKE OF THE FRONT.
PREV DISCUSSION... /ISSUED 344 PM CDT THU OCT 4 2012/
DISCUSSION...
MUCH ANTICIPATED COLD FRONT HAS ARRIVED IN NORTHEAST OK AND WAS
POSITIONED NEAR I-44 AT 3 PM. AT THIS TIME ONLY MODEST PRESSURE
RISES NOTED IMMEDIATELY IN ITS WAKE AND THE FRONTS PROGRESS
SOUTHEAST WILL BE SLOW WITH THE FRONT LIKELY STALLING AS IT BEGINS
TO ENCOUNTER HIGHER TERRAIN. RELATIVELY HIGH DEW POINTS POOLING
NEAR THE BOUNDARY IN SOUTHERN OK HAVE RESULTED IN A NARROW AXIS OF
INSTABILITY...HOWEVER WARM MID LEVEL TEMPS KEEPING A STRONG CAP IN
PLACE AND CLOUD COVER HAS LIMITED SFC HEATING POTENTIAL SOMEWHAT.
STILL A SMALL THREAT OF AN ISOLATED STORM DEVELOPING ALONG
BOUNDARY BUT BETTER CHANCES ARRIVE LATE THIS EVENING WITH
STRENGTHENING WINDS ATOP THE COOL AIR EVENTUALLY RESULTING IN
WIDESPREAD ELEVATED THUNDERSTORMS NORTH OF THE FRONT. THE
INCREASING DEEP LAYER SHEAR DOES LEND AT LEAST SOME POSSIBILITY TO
ORGANIZED STORMS BUT OVERALL SEVERE THREAT LOOKS LOW AT THIS TIME.
PROGRESS OF THE FRONT WILL CONTINUE TO BE SLOW THROUGH THE DAY
FRIDAY WITH POST FRONTAL SHOWERS AND A FEW THUNDERSTORMS SHIFTING
EAST. THIS WILL LIKELY RESULT IN A WIDE RANGE OF HIGH TEMPS ACROSS
THE AREA AND A ZONE OF HIGH UNCERTAINTY FROM NW CORNER OF ARKANSAS
THROUGH SE OKLAHOMA. IN GENERAL HAVE GONE LOWER THE GUIDANCE FOR
MAX TEMPS...WITH EXCEPTION OF THOSE AREAS. BREAK IN PRECIP WILL
OCCUR FOR A TIME LATE FRIDAY BEFORE ANOTHER SURGE NORTH OF THE
FRONT FRIDAY NIGHT...WHICH BY THIS TIME SHOULD BE SOUTH OF THE RED
RIVER AS REINFORCING SHOT OF DEEPER COLD AIR ARRIVES.
APPROACHING UPPER LEVEL WAVE FROM THE NORTHWEST WILL KEEP RAIN
CHANCES GOING THROUGH SATURDAY WITH TEMPS STRUGGLING TO REACH 50
IN MANY AREAS...AND RECORD LOW MAXES VERY LIKELY AT TUL/FSM. AS
THIS WAVE PASSES TO THE NORTH...WILL BEGIN TO SEE SOME CLEARING
ACROSS NORTHERN AREAS. POTENTIAL FOR FREEZING TEMPS LOOKING HIGH
OVER FAR NORTHERN AREAS...HOWEVER THERE REMAINS SOME UNCERTAINTY
AS TO HOW MUCH SKIES WILL CLEAR AND HOW SOON. WITH THIS
UNCERTAINTY IN PLACE IN THE 5TH PERIOD OF THE FORECAST WILL NOT
ISSUE A FREEZE WATCH YET...BUT SOME HIGHLIGHTS LIKELY TO BE NEEDED
FOR SUN MORNING ESPECIALLY GIVEN HOW EARLY IN THE SEASON IT IS.
CONTINUED COOL SUNDAY WITH LIGHT WINDS...WHICH COME AROUND SOUTH
LATE. HOWEVER...NIT LATE ENOUGH TO KEEP TEMPS FROM FALLING AT OR A
LITTLE BELOW FREEZING IN THE MORE SHELTERED VALLEY AREAS TO THE
EAST AND SOUTH. A NICE WARM UP WILL OCCUR TUE AHEAD OF ANOTHER
APPROACHING FRONT WHICH WILL BRING ANOTHER CHANCE OF PRECIP TO THE
AREA WED/THU.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS NORMAN OK
1100 PM CDT THU OCT 4 2012
.UPDATE...
ADJUSTED OVERNIGHT TEMPERATURE TRENDS AND POPS THROUGH 12Z.
TEMPS HAVE DECREASED SLOWLY TONIGHT UNDER OVERCAST SKIES.
LOCATIONS ACROSS NORTHERN OKLAHOMA REMAIN IN THE UPPER 50S...
WHILE LOCATIONS SOUTH OF THE I-40 CORRIDOR CONTINUE TO HOVER IN
THE LOWER 60S. STILL EXPECTING A COOL NIGHT...WITH TEMPS IN THE
UPPER 40S ALONG AND NEAR THE KANSAS BORDER TO LOWS RANGING IN THE
50S ACROSS THE REST OF OKLAHOMA AND WESTERN NORTH TEXAS.
MODEL SOUNDINGS FROM OKC AND ACROSS CENTRAL OK CONTINUE TO SHOW A
DECENT EML/WARM LAYER PERSISTING ACROSS THE REGION. THIS WILL
CONTINUE TO LIMIT CONVECTION ACROSS THE MAJORITY OF CENTRAL AND
WESTERN OKLAHOMA INTO WESTERN NORTH TEXAS OVERNIGHT. STILL KEPT
SLIGHT CHANCE TO CHANCE POPS GOING ACROSS THE EASTERN PORTIONS OF
THE FORECAST AREA AS A FEW ISOLATED SHOWERS HAVE CONTINUED TO
LINGER ACROSS CENTRAL OKLAHOMA. ADJUSTED POPS AFTER 06Z AS AN
INCREASE IN ISENTROPIC LIFT AND COOLING OF THE LOW LEVELS MAY
WEAKEN THE CAP JUST ENOUGH TO ALLOW SCATTERED CONVECTION. IN
RESPONSE...SHORT RANGE GUIDANCE FROM THE HRRR AND RAP SUPPORT
SHOWERS AND ISOLATED THUNDER ACROSS THE EASTERN PORTIONS OF THE
CWA SOUTHWARD INTO NORTHEASTERN TEXAS THROUGH 12Z.
KURTZ
&&
.PREV DISCUSSION... /ISSUED 640 PM CDT THU OCT 4 2012/
AVIATION...
05/00Z TAFS...PRIMARILY MVFR CONDITIONS EXPECTED AT ALL BUT FAR
NORTHERN OKLAHOMA TERMINALS THROUGH 15-18Z BEFORE ALL SITES EXPECTED
TO BECOME VFR. SPOTTY DRIZZLE WILL BE SEEN THIS EVENING PRIMARILY
AROUND KPNC AND KOKC/KOUN. WILL NOT INCLUDE DUE TO SHORT DURATION
AND MINIMAL IMPACTS ON CIG/VIS. HOWEVER WILL INCLUDE TEMPO -SHRA
ACROSS KOKC/KOUN TERMINALS 04-08Z AS FINE SCALE MODELS INDICATE
DEVELOPMENT OF LIGHT RAIN BANDS NEAR I-44. RIGHT NOW WE EXPECT TSRA
TO STAY EAST OF TERMINALS.
DISCUSSION...
..RECORD COLD HIGH TEMPERATURES EXPECTED SATURDAY
AFTERNOON...WITH PATCHY FROST POSSIBLE BY SUNDAY MORNING...
THE INITIAL COLD FRONT HAS PROGRESSED ALL THE WAY INTO WESTERN
NORTH TEXAS AND PORTIONS OF SOUTHERN OK THIS AFTERNOON.
ACCOMPANYING POST FRONTAL STRATUS CLOUDS HAVE KEPT TEMPS FROM
CLIMBING OUT OF THE 60S BEHIND THE FRONT. LATER TONIGHT MODEST
ISENTROPIC ASCENT AND LOW LEVEL MOISTURE ADVECTION WILL RESULT IN
INCREASED RAIN CHANCES ESPECIALLY ALONG AND EAST OF I44. IN
ADDITION...POCKETS OF MODERATE ELEVATED INSTABILITY COMBINED WITH
INCREASING WESTERLY FLOW ALOFT MAY SUPPORT SOME HAIL DURING THE
OVERNIGHT HOURS. THE STRATUS WILL LINGER THROUGH TOMORROW KEEPING
TEMPERATURES WELL BELOW NORMAL NEAR THE MID TO UPPER 50S.
TWO OTHER DIGGING SHORTWAVE TROUGHS WILL DIVE SOUTH OUT OF CANADA
FRIDAY AND FRIDAY NIGHT...WITH THE MOST POTENT ONE MOVING INTO THE
CENTRAL PLAINS BY SATURDAY MORNING. THIS WILL PUSH AN EVEN COLDER
AIRMASS INTO THE REGION THROUGH LATE SATURDAY. RECORD COLD HIGHS
ARE ANTICIPATED BY SATURDAY AFTERNOON AS A ~1030MB HIGH MOVES INTO
THE LEE OF THE ROCKIES NEAR EASTERN CO. CLEARING SKIES AND
DEWPOINTS IN THE MID TO UPPER 20S UNDER THE SURFACE RIDGE WILL
ALLOW FOR EXCELLENT RADIATIONAL COOLING SUNDAY MORNING. PATCHY
FROST WILL BE POSSIBLE MAINLY ALONG AND NORTH OF I40. A SLOW WARM
UP IS EXPECTED THROUGH MID NEXT WEEK AS ZONAL FLOW RETURNS OVER
THE SOUTHERN ROCKIES...AHEAD OF A PAC CLOSED LOW MOVING ONSHORE
NEAR SCENTRAL CAL. IT IS UNCLEAR HOW THIS LOW WILL PROGRESS
THROUGH LATE NEXT WEEK...ALTHOUGH INCREASING RAIN CHANCES/MOISTURE
APPEAR LIKELY BY NEXT WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 51 57 44 51 / 20 20 30 20
HOBART OK 51 59 46 51 / 20 20 40 20
WICHITA FALLS TX 56 60 47 52 / 20 20 60 20
GAGE OK 47 55 40 48 / 10 10 20 20
PONCA CITY OK 49 57 40 51 / 20 10 20 20
DURANT OK 66 68 46 54 / 20 20 60 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/11/03
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1154 PM CDT THU OCT 4 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
257 PM CDT THU OCT 4 2012
MAIN FORECAST CONCERNS ON BREEZY NORTHWEST WINDS THIS EVENING AND
AGAIN ON FRIDAY. FOCUS THEN TURNS TO LOW PRECIPITATION CHANCES ON
SATURDAY AND TEMPERATURES THROUGH THE WEEKEND.
LATEST WATER VAPOR IMAGERY SHOWED A POTENT LOW PRESSURE SYSTEM OVER
NORTHERN MINNESOTA RESPONSIBLE FOR PRODUCING HEAVY...WET SNOW OVER
PORTIONS OF NORTHWEST MINNESOTA. SURFACE OBSERVATIONS INDICATED A
TIGHT PRESSURE GRADIENT OVER THE FORECAST AREA IN THE WAKE OF A
COLD FRONT THAT MOVED THROUGH THIS MORNING. THE TIGHT GRADIENT AND
COLD AIR ADVECTION BEHIND THE FRONT WAS KEEPING BREEZY
WEST/NORTHWEST ACROSS THE FORECAST AREA.
THE LOW IS EXPECTED TO LIFT NORTHEAST TONIGHT INTO SOUTHWEST ONTARIO
AND MEANDER EAST...JUST NORTH OF LAKE SUPERIOR. A TIGHT PRESSURE
GRADIENT WILL REMAIN IN PLACE OVER THE AREA AS THE REGION IS IN
BETWEEN THE LOW PASSING TO THE NORTH AND HIGH PRESSURE ATTEMPTING
TO BUILD INTO THE DAKOTAS. THIS WILL KEEP BREEZY CONDITIONS
THROUGH THIS EVENING. WINDS WILL TAPER OFF LATE IN THE EVENING FOR
LOCATIONS ALONG AND SOUTH OF INTERSTATE 90. NAM AND RUC LOW LEVEL
RELATIVE HUMIDITY FIELDS SHOWS A SCATTERED TO BROKEN STRATUS DECK
MOVING IN FROM THE NORTHWEST THIS EVENING AND MAKING IT TO ABOUT
THE INTERSTATE 90 CORRIDOR. HAVE INCREASED CLOUD COVER THIS
EVENING INTO THE OVERNIGHT HOURS ACROSS THESES AREAS. LOOK FOR LOW
TEMPERATURES TO FALL INTO THE 30S TONIGHT.
AN UPPER TROUGH WILL DIVE SOUTH INTO THE DAKOTAS AND NORTHERN
MINNESOTA ON FRIDAY OUT OF SOUTHERN MANITOBA...SASKATCHEWAN AND
ALBERTA AS THE LOW FILLS AND LIFTS NORTHEAST OVER JAMES BAY. PLAN ON
CONTINUED BREEZY NORTHWEST WINDS ACROSS THE AREA ON FRIDAY AS THE
PRESSURE GRADIENT REMAINS TIGHT. WIND SPEEDS ARE EXPECTED TO RANGE
FROM 14 TO 24 MPH. SOME GUSTS IN THE 25 TO 30 MPH RANGE ARE
POSSIBLE IN OPEN AREAS. THE GRADIENT WILL REMAIN TIGHTER THOUGH
THE DAY ACROSS CENTRAL INTO NORTH CENTRAL WISCONSIN SO HAVE
INCREASED WINDS GUSTS SLIGHTLY ACROSS THESE AREAS. HIGH
TEMPERATURES WILL RANGE FROM THE LOWER 40S ACROSS NORTHERN
WISCONSIN TO THE LOWER 50S OVER NORTHEAST IOWA. THE TROUGH IS
EXPECTED TO PUSH SOUTH INTO CENTRAL MINNESOTA AND NORTHERN
WISCONSIN LATE FRIDAY NIGHT INTO SATURDAY MORNING. CLOUDS WILL BE
ON THE INCREASE FROM NORTH TO SOUTH AS THE TROUGH MOVES IN. CANNOT
RULE OUT A LIGHT SPRINKLE OR SNOW SHOWER FRIDAY NIGHT INTO
SATURDAY MORNING ALONG AND NORTH OF THE INTERSTATE 94 CORRIDOR.
FORECAST SOUNDING ARE NOT SHOWING ENOUGH SATURATION FOR ICE ALOFT
SO THE PRECIPITATION COULD FALL AS SPRINKLES OR POSSIBLY FREEZING
SPRINKLES DEPENDING ON SURFACE TEMPERATURES. THERE APPEARS TO BE
ENOUGH SATURATION FOR PRECIPITATION BUT THERE REALLY IS NOT
APPRECIABLE LIFT SO CONCERNED THAT THE MAIN IMPACT FROM THE TROUGH
WILL BE JUST INCREASING STRATUS AND NO PRECIPITATION. WILL
MAINTAIN SLIGHT CHANCES FOR RAIN/SNOW SHOWERS OVER NORTH CENTRAL
WISCONSIN. PLAN ON LOW TEMPERATURES RANGING FROM THE UPPER 20S TO
LOWER 30S OVER NORTH CENTRAL WISCONSIN TO THE LOWER 30S OVER
NORTHEAST IOWA. GUIDANCE HAS BEEN TRENDING COOLER FRIDAY NIGHT BUT
CONCERNED THAT THE INCREASING CLOUD COVER AND PERSISTENT NORTHWEST
WINDS WILL LEAD TO SLIGHTLY WARMER TEMPERATURES. WILL HAVE TO KEEP
A CLOSE WATCH ON THE PROGRESSION OF THE STRATUS DECK FRIDAY NIGHT
AND WINDS. LOCATIONS THAT REMAIN CLEAR AND DECOUPLE COULD SEE
TEMPERATURES PLUMMET INTO THE MID 20S.
SATURDAY WILL BE A RATHER CHILLY FALL DAY ACROSS THE REGION. THE
TROUGH WILL CONTINUE ITS SOUTHWARD PUSH...LEADING TO AN EXPANSIVE
STRATUS DECK ACROSS MUCH OF THE FORECAST AREA. DECIDED TO MAINTAIN A
SLIGHT CHANCE FOR RAIN/SNOW SHOWERS OVER NORTH CENTRAL WISCONSIN AS
THE TROUGH MOVES THROUGH DURING THE MORNING HOURS. HAVE INCLUDED A
CHANCE OF FLURRIES ACROSS WEST CENTRAL WISCONSIN INTO SOUTHEAST
MINNESOTA AND NORTHEAST IOWA EARLY SATURDAY MORNING...THEN SWITCHED
OVER TO SPRINKLES LATE IN THE MORNING AS TEMPERATURES WARM. SEEING
THE SATURATION FOR SOME PRECIPITATION IN THE FORECAST SOUNDINGS BUT
VERY MINIMAL LIFT. THINKING THE TROUGH SHOULD BE ABLE TO PRODUCE
SOME VERY LIGHT PRECIP AS IT MOVES THROUGH. OTHERWISE...PLAN ON A
MOSTLY CLOUDY AND COOL DAY WITH HIGHS RANGING FROM THE LOWER 40S
OVER NORTHERN WISCONSIN TO THE UPPER 40S ACROSS NORTHEAST IOWA.
SATURDAY INTO SATURDAY NIGHT...850 MB TEMPERATURE STANDARDIZED
ANOMALIES WILL FALL TO AROUND -1.5 C BASED ON THE ECMWF....WHILE
THE NAM IS SUGGESTING -2.0 C. ANOMALIES THIS LOW SUGGEST THE
POTENTIAL FOR NEAR RECORD LOW TEMPERATURES ACROSS THE REGION. THE
COLD AIRMASS OVER THE REGION AND CLEARING SKIES LATE SATURDAY
NIGHT INTO EARLY SUNDAY MORNING WILL LEAD TO NEAR RECORD LOW
TEMPERATURES AND A HARD...GROWING SEASON ENDING FREEZE...WITH LOWS
FALLING INTO THE 20S. A FREEZE WARNING WILL BE NEEDED LATE
SATURDAY NIGHT INTO EARLY SUNDAY MORNING. SURFACE HIGH PRESSURE
WILL EDGE INTO THE REGION ON SUNDAY WITH MOSTLY SUNNY SKIES
EXPECTED. AFTER A COLD START TO THE DAY...LOOK FOR HIGH
TEMPERATURES TO REBOUND INTO THE UPPER 40S OVER NORTHERN WISCONSIN
TO THE LOWER 50S ACROSS NORTHEAST IOWA.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
257 PM CDT THU OCT 4 2012
04.12 MEDIUM RANGE MODELS IN REASONABLE AGREEMENT THROUGH THE
EXTENDED PERIOD. NORTHWEST FLOW ALOFT WILL CONTINUE INTO SUNDAY
NIGHT WITH SURFACE HIGH PRESSURE IN CONTROL. THE HIGH IS EXPECTED TO
SLIDE EAST OF THE AREA MONDAY AS A COLD FRONT DRIFTS SOUTH ACROSS
NORTHERN MINNESOTA INTO SOUTHERN NORTH DAKOTA. MEANWHILE...AN UPPER
TROUGH WILL MOVE THROUGH MONTANA AND INTO WESTERN NORTH DAKOTA.
SOUTHWEST FLOW AHEAD OF THE APPROACHING FRONT WILL HELP TEMPERATURES
CLIMB INTO THE UPPER 50S TO LOWER 60S ACROSS THE FORECAST AREA
MONDAY AFTERNOON. THE FRONT IS EXPECTED TO PUSH SOUTH INTO NORTHERN
WISCONSIN LATE MONDAY NIGHT BRINGING A SLIGHT CHANCE OF RAIN SHOWERS
TO NORTH CENTRAL WISCONSIN. THE FRONT WILL CONTINUE TO MOVE SOUTH
DURING THE DAY ON TUESDAY BRINGING A SLIGHT CHANCE OF RAIN SHOWERS
TO MUCH OF THE FORECAST AREA. HIGH PRESSURE IS EXPECTED TO BUILD
BACK INTO THE UPPER MISSISSIPPI RIVER VALLEY WEDNESDAY INTO THURSDAY
PROVIDING DRY AND QUIET WEATHER. LOOK FOR HIGH TEMPERATURES IN THE
50S ON WEDNESDAY...CLIMBING INTO THE MID 50S TO LOWER 60S THURSDAY
AFTERNOON.
&&
.AVIATION...THROUGH 06Z SATURDAY
1154 PM CDT THU OCT 4 2012
THE VFR STRATUS DECK NORTH OF THE TAF SITES EARLIER THIS EVENING
DID MAKE IT INTO THE TAF SITES LATE THIS EVENING. WESTERLY WINDS
CONTINUE TO GUST UPWARDS OF 20 TO 25 KNOTS AT BOTH SITES. EXPECT
CEILINGS OF 035K-040K FOOT TO PERSIST THROUGH THE OVERNIGHT HOURS.
LATEST SATELLITE TRENDS DOES SHOW SOME ERODING OF THE CLOUDS ALONG
THE SOUTHERN FLANK...SO TAF SITES MAY REMAIN ON THE EDGE. WINDS
WILL REMAIN STRONG OVERNIGHT WITH SOME GUSTS CONTINUING IN THE 20
TO 25 KNOT RANGE. STRATUS SHOULD MIX OUT FRIDAY AFTER 15Z WITH
PRESSURE GRADIENT REMAINING TIGHT AND WINDS CONTINUING TO GUST
UPWARDS OF 25 KNOTS. ANOTHER SURFACE TROUGH DROPS SOUTHWARD
THROUGH NORTHERN MINNESOTA AFTER 00Z SATURDAY. NAM IS SHOWING A
SOUTHWARD PUSH OF 850MB-925MB MOISTURE TOWARDS THE TAF SITES.
TIMING AT THIS TIME LOOKS TO BE AROUND OR JUST AFTER 06Z...SO WILL
JUST KEEP MENTION OF A SCATTERED DECK AT THIS TIME....BUT WILL
LIKELY SEE SOME CEILINGS DEVELOP AFTER 06Z IN THE UPPER MVFR LOWER
VFR CATEGORY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
257 PM CDT THU OCT 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1011 AM CDT FRI OCT 5 2012
.DISCUSSION...
ISSUED 958 AM CDT FRI OCT 5 2012
BAND OF STEADIER RAIN HAS SHIFTED SOUTH AND WAS CENTERED ALONG THE
I-70 CORRIDOR LATE THIS MORNING...WITH SCATTERED SHOWERS TO THE
NORTHWEST. LATEST RAP MODEL KEEPS THE BULK OF THE RAIN SOUTH OF A
DANVILLE TO TAYLORVILLE LINE THE REMAINDER OF THE DAY...ALTHOUGH
THE HRRR AND NAM-12 SHOW SOME FILLING IN OF THE SCATTERED RAIN
ACROSS THE NORTHWEST CWA. TEMPERATURES ARE GOING NOWHERE FAST...
EXCEPT IN THE EXTREME SOUTHEAST WHERE THE RAIN HAS NOT STARTED
YET. HAVE LOWERED HIGH TEMPERATURES OVER MOST OF THE CWA...WITH
VALUES ONLY RISING A COUPLE MORE DEGREES ESPECIALLY IN THE RAINY
AREAS. UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 605 AM CDT FRI OCT 5 2012
COLD FRONT WHICH PUSHED ACRS OUR AREA YESTERDAY AFTERNOON AND
EVENING HAS SHIFTED WELL SOUTH OF THE TAF SITES EARLY THIS
MORNING. WEAK LOW PRESSURE ALONG THE BOUNDARY TO OUR SOUTHWEST
HAS PRODUCED BANDS OF SHOWERS AND ISOLD TSRA THRU EARLY THIS
MORNING ALONG WITH AREAS OF MVFR CIGS...ESPECIALLY WHERE THE
MORE CONCENTRATED AREA OF STEADIER RAINS HAS OCCURRED. WE EXPECT
SIMILAR CONDITIONS TO PREVAIL THRU MOST OF THE DAY WITH FORECAST
SOUNDINGS SUGGESTING OCNL MVFR OR LOWER CIGS IN RAIN WITH THE
POSSIBILITY FOR ISOLD CONVECTION AS WELL...ESPECIALLY AT SPI...
DEC...AND CMI. THE RAIN SHIELD WILL GRADUALLY BEGIN TO SHIFT
SOUTHEAST LATE TODAY AS THE SFC HIGH BUILDS SE INTO THE MIDWEST
BRINGING VFR CONDITIONS TO THE REMAINDER OF THE FORECAST AREA
AFTR 01Z. SFC WINDS WILL BE OUT OF THE N-NW AT AROUND 10 KTS
DURING THE DAY...AND THEN DROP TO BETWEEN 5 AND 10 KTS TONIGHT.
SMITH
&&
.PREV DISCUSSION...
ISSUED 214 AM CDT FRI OCT 5 2012
SHORT TERM...TODAY THROUGH SUNDAY
06Z/1AM SURFACE ANALYSIS SHOWS COLD FRONT JUST NORTH OF THE OHIO
RIVER...WITH CHILLY AIRMASS SETTLING SOUTHWARD INTO THE REGION.
WELL NORTH OF THE BOUNDARY...FRONTOGENETIC FORCING ALONG THE
MID-LEVEL BAROCLINIC ZONE IS TRIGGERING A BAND OF SHOWERS WITH
EMBEDDED THUNDERSTORMS FROM SOUTHEAST KANSAS NORTHEASTWARD INTO
CENTRAL ILLINOIS. AT THE CURRENT TIME...THE RAIN IS MAINLY
CENTERED ALONG A WATSEKA...TO LINCOLN...TO PITTSFIELD LINE. A
CLOSER LOOK AT FORCING SHOWS THE NAM 850MB FRONTOGENESIS FIELD
DEPICTING THE RAIN BAND QUITE NICELY...SO WILL FOLLOW THIS
PARAMETER CLOSELY FOR THE SHORT-TERM FORECAST. WITH REGION
REMAINING IN THE RIGHT ENTRANCE REGION OF A 300MB JET STREAK
ACROSS THE GREAT LAKES AND PRIMARY MID-LEVEL FORCING ONLY VERY
SLOWLY SINKING SOUTHWARD...THINK SHOWERS WILL BE WIDESPREAD ACROSS
THE CENTRAL AND SOUTHERN KILX CWA FOR MUCH OF THE DAY. BASED ON
LATEST RADAR LOOPS AND NAM FRONTOGENESIS...HAVE FOCUSED HIGHEST
POPS ALONG/SOUTH OF A RUSHVILLE TO BLOOMINGTON-NORMAL LINE THROUGH
MIDDAY. AFTER THAT...STRONGEST FORCING SHIFTS SOUTH TO ALONG THE
I-70 CORRIDOR DURING THE AFTERNOON. GIVEN STEEP LAPSE RATES ABOVE
700MB...WILL CONTINUE TO MENTION ISOLATED THUNDER THROUGHOUT THE
DAY AS WELL. RAIN TOTALS COULD EXCEED 1 INCH IN SOME LOCATIONS
ACROSS THE CENTRAL CWA...WITH AMOUNTS RAPIDLY DROPPING TO LESS
THAN ONE QUARTER OF AN INCH ACROSS THE FAR NORTH AROUND GALESBURG.
WITH COOL N/NE FLOW AND OFF-AND-ON SHOWERS...TEMPS WILL REMAIN
NEARLY STEADY IN THE UPPER 40S AND LOWER 50S.
AS SHORT-WAVE PUSHES EAST OF THE AREA...FRONT WILL FINALLY GET
SHOVED FURTHER SOUTH TONIGHT. MOST MODEL GUIDANCE IS SUGGESTING
SHOWERS PERSISTING ACROSS THE E/SE CWA THROUGH EVENING...BEFORE
GRADUALLY EXITING INTO INDIANA OVERNIGHT. WILL THEREFORE MAINTAIN
CHANCE POPS ALONG/EAST OF I-55 THROUGH MIDNIGHT...THEN JUST ACROSS
THE FAR SE AROUND LAWRENCEVILLE OVERNIGHT. FORECAST SOUNDINGS
INDICATE CLEARING SKIES FROM NORTHWEST TO SOUTHEAST ACROSS THE
AREA TONIGHT...WITH MOST LOCATIONS SEEING CLEAR SKIES BY DAWN
SATURDAY. GIVEN CLEARING SKIES AND CONTINUED CAA...OVERNIGHT LOWS
WILL DROP INTO THE MIDDLE TO UPPER 30S.
AFTER A COOL/DRY DAY ON SATURDAY...A VIGOROUS SHORT-WAVE WILL DIVE
OUT OF CANADA AND TRACK ACROSS THE AREA SATURDAY NIGHT. PREVIOUS
MODEL SOLUTIONS HAD SUGGESTED THAT THIS FEATURE COULD PULL THE
FRONT BACK NORTHWARD A BIT...POTENTIALLY BRINGING CLOUDS/SHOWERS
INTO THE SE CWA. THE 00Z NAM AND GFS BOTH KEEP ANY PRECIP WELL
SOUTH OF THE AREA...SO HAVE REMOVED PRECIP MENTION. MAIN STORY
WILL BE THE COLD WEATHER AND POTENTIAL FOR FREEZING TEMPS AND/OR
FROST. WITH SHORT-WAVE MOVING THROUGH THE AREA...PARTIAL CLOUD
COVER WILL LIKELY MITIGATE RADIATIONAL COOLING TO SOME EXTENT. IN
ADDITION...WITH SURFACE HIGH CENTERED OVER THE PLAINS...LIGHT N/NW
WINDS MAY ALSO PREVENT TEMPS FROM DROPPING AS LOW AS THEY WOULD
OTHERWISE. AS A RESULT...DO NOT THINK THERE WILL BE A WIDESPREAD
FROST OR FREEZE. INSTEAD...MOST LOCATIONS WILL DROP INTO THE
MIDDLE 30S...WITH A FEW FAVORED LOW-LYING/RURAL SPOTS DIPPING TO
NEAR OR SLIGHTLY BELOW FREEZING. BETTER OPPORTUNITY FOR
FROST/FREEZE MAY DEVELOP SUNDAY NIGHT ACROSS THE E/SE CWA AS RIDGE
AXIS SLIDES EASTWARD INTO THE OHIO RIVER VALLEY BY 12Z MON.
LIGHTEST WINDS WILL LIKELY OCCUR ALONG/SOUTHEAST OF A CHAMPAIGN TO
TAYLORVILLE LINE...SO THIS WILL BE THE AREA TO WATCH FOR POTENTIAL
WIDESPREAD FREEZE. FURTHER WEST...WEAK RETURN FLOW ON THE BACK
SIDE OF THE HIGH WILL KEEP TEMPS A COUPLE OF DEGREES WARMER.
LONG TERM...MONDAY THROUGH THURSDAY
MODERATING TEMPS ARE IN STORE FOR MONDAY AND TUESDAY...AS SOUTHERLY
FLOW BOOSTS HIGH TEMPS BACK INTO THE 60S. NEXT UPPER-WAVE AND
ASSOCIATED COLD FRONT IS SLATED TO APPROACH THE AREA LATE TUESDAY
INTO WEDNESDAY. 00Z GFS TRIES TO SPREAD SHOWERS INTO WEST-CENTRAL
ILLINOIS AS EARLY AS TUESDAY AFTERNOON...HOWEVER GIVEN DRY AIRMASS
IN PLACE...HAVE OPTED TO KEEP TUESDAY DRY. WILL INSTEAD FOCUS POPS
TUESDAY NIGHT...WHEN BOTH THE GFS AND ECMWF AGREE THAT FRONT WILL
PASS THROUGH. AFTER THAT...DRY WEATHER AND SLIGHTLY COOLER TEMPS
IN THE UPPER 50S/LOWER 60S WILL BE IN STORE FOR BOTH WEDNESDAY AND
THURSDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
644 AM CDT FRI OCT 5 2012
.UPDATE...
AS EXPECTED...THERE HAS BEEN A BRIEF LULL WITH PRECIP DROPPING
DOWN TO MAINLY SPRINKLES. RADARS THE PAST 30-45 MINUTES HAVE SHOWN
NEW DEVELOPMENT ACROSS NORTHERN MISSOURI AND INTO EXTREME SOUTHERN
IOWA. SOME OF THIS IS LIKELY MID LEVEL CLOUDS BASED ON APPEARANCE
AND CORRELATION WITH SATELLITE IMAGES. HOWEVER...SOME OF IT IS
LEGITIMATE SPRINKLES OR HIGH BASED SHRA ASSOCIATED WITH SOME
FORCING. SFC OBS INDICATE A WEAK TROF FROM ROUGHLY NORTHERN
WISCONSIN TO NEAR KOMA.
RAP TRENDS SHOW THIS FORCING CONTINUING INTO THE MORNING COMMUTE
BEFORE WEAKENING. THUS ANOTHER LULL MIGHT OCCUR FOR A FEW HOURS
LATE THIS MORNING BEFORE PRECIP RE-DEVELOPS AGAIN WITH THE ARRIVAL
OF THE SHORTWAVE. THE RAP AND WRF MODELS SUGGEST THE WEAK TROF
MOVING THROUGH IOWA MAY PROVIDE SOME ADDITIONAL FOCUS FOR DIURNAL
SHRA ACTIVITY OVER NOT QUITE THE SOUTHEAST HALF OF THE CWFA DURING
THE AFTERNOON HOURS. EXTRAPOLATION OF THE 12HR RAP POSITIONS
SUGGEST THE POSSIBILITY OF SOME SPRINKLES LINGERING PAST 00Z IN
THE FAR EAST/SOUTHEAST PARTS OF THE CWFA.
THE 06Z MODELS CONTINUE TO SHOW THE UPPER JET OVER THE AREA
TONIGHT SUGGESTING CS/CI MAY COME INTO PLAY WITH TEMPERATURES. THE
2 METER TEMPS FROM THE WRF LOOK TOO COLD. HOWEVER...IF CLOUD COVER
IS THIN ENOUGH THE DRY GROUND MAY NEGATE THE AFFECTS OF THE
CLOUDS. THUS THE POTENTIAL IS STILL THERE FOR POSSIBLE FREEZE
HEADLINES TONIGHT. ..08..
&&
.AVIATION...
VFR WX IS EXPECTED THROUGH 12Z/06 AS HIGH PRESSURE SLOWLY BUILDS
INTO THE MIDWEST. A DISTURBANCE MOVING THROUGH MAY PRODUCE SOME
SPRINKLES OR A LIGHT SHRA AT KMLI/KBRL. CLEARING SKIES AND
DECREASING WINDS AFT SUNSET MAY RESULT IN FROST FORMATION ON NON-
HANGARED ACFT. ..08..
&&
.PREV DISCUSSION... /ISSUED 324 AM CDT FRI OCT 5 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE COLD FRONT FROM LAKE HURON INTO TEXAS WITH
SFC WAVES IN SOUTHWEST MISSOURI AND NORTH TEXAS. A WEAK TROF RAN
FROM SOUTHERN LAKE MICHIGAN BACK TO THE KMCI AREA WITH ANOTHER FROM
LAKE SUPERIOR TO NEAR KHON. DEW POINTS ALONG AND SOUTH OF THE FRONT
WERE IN THE 50S AND 60S WITH 40S FROM LAKE MICHIGAN INTO KANSAS. DEW
POINTS IN THE 20S AND 30S WERE ACROSS MUCH OF THE PLAINS AND UPPER
MISSISSIPPI VALLEY.
SHORT TERM...TODAY AND TONIGHT...
RADAR RETURNS SHOW A WEAK AREA OF SPRINKLES/SHRA FROM SOUTH OF KIOWA
BACK THROUGH SOUTHERN IOWA. THIS PRECIPITATION APPEARS TO BE DUE TO
A MOISTURE AND THETA E GRADIENT PER RAP TRENDS AND THE OTHER MODELS.
THESE FEATURES WILL SLOWLY WEAKEN THE REMAINDER OF THE NIGHT INTO
THE MORNING COMMUTE. THE BETTER FORCING WITH THE MORE SUBSTANTIAL
SHRA ACTIVITY WILL CONTINUE ACROSS THE FAR SOUTHERN PARTS OF THE
CWFA THROUGH THE MORNING COMMUTE AS WELL. THERE MAY OR MAY NOT BE A
LULL IN THE PRECIPITATION DURING THE LATE MORNING HOURS WHILE THE
NEXT SHORTWAVE APPROACHES FROM THE PLAINS.
DURING THE AFTERNOON THIS SHORTWAVE MOVES ACROSS THE AREA. THERE IS
A COUPLED UPPER JET STRUCTURE WHICH WILL PROVIDE GENERAL SYNOPTIC
LIFT. THE SOUTH HALF OF THE CWFA WILL HAVE THE BETTER CHANCE AT
SEEING SHRA ACTIVITY.
TONIGHT...THERE MAY OR MAY NOT BE SOME LINGERING SPRINKLES IN THE
FAR EAST FOR A FEW HOURS. ALL MODELS SHOW A MOISTURE GRADIENT OVER
THE AREA WITH A DIFFUSE BUT WEAKENING THETA E GRADIENT. SO...HAVE
OPTED TO KEEP TONIGHT DRY.
THE LARGER CONCERN IS TEMPERATURES. ALL MODELS SHOW THE UPPER JET
OVER THE AREA WHICH COULD PROVIDE SOME CI/CS WHILE IN THE LOWER
LEVELS THE MODELS SUGGEST CLOUDS WITH THE INCREASING CYCLONIC FLOW
FROM THE SHORTWAVE DROPPING DOWN FROM THE NORTH. INTERESTINGLY...
THE MODELS ARE INDICATING SUBSIDENCE AND THUS POSSIBLE CLEAR SKIES.
CLOUD COVER WILL BE THE KEY TO HOW COLD IT GETS. IF THERE ARE CLOUDS
BUT THEY ARE THIN...THEN THE DRY GROUND MAY OFFSET THE CLOUDS AND
ALLOW TEMPERATURES TO DROP MORE THAN FCST. THE POTENTIAL DOES EXIST
FOR FREEZE HEADLINES FOR TONIGHT FROM ABOUT HWY 30 ON SOUTH. ..08..
LONG TERM...SATURDAY THROUGH THURSDAY...
THIS EXTENDED PERIOD WILL MAINLY FOCUS ON TEMPERATURES WITH
ACTIVE...YET MAINLY DRY NORTH TO NORTHWEST FLOW. SATURDAY SHOULD BE
QUITE COLD AND WITH A STRATOCUMULUS DECK SPREADING OVER THE REGION
EARLY IN THE DAY...WE MAY BE HARD PRESSED TO REACH 50 IN MANY
LOCATIONS. FOR NOW...IT IS MOST LIKELY TO BE CLOUDY EARLY ENOUGH IN
THE DAY TO HOLD THE NORTH 1/3 TO THE UPPER 40S FOR HIGHS...WHILE THE
SOUTH COULD REACH THE LOWER 50S. THIS MOST CERTAINLY APPEARS TO BE
THE COLDEST DAY IN THIS CURRENT STRETCH OF CHILLY WEATHER. SATURDAY
NIGHT...ALL MODELS DECREASE SKY COVER FROM WEST TO EAST DURING THE
LATE AFTERNOON/EARLY EVENING HOURS. COMBINED WITH LIGHT WINDS AND
LINGERING VERY COLD AIRMASS ALOFT...WE SHOULD DROP TO LOWS IN THE
20S OVER MOST OF THE CWA...WITH SOME LOWER TO MID 20S IN FAVORED
LOWER LYING AREAS. SHOULD TONIGHT NOT RESULT IN FREEZE
CONDITIONS...HEADLINES SHOULD BE REQUIRED FOR SATURDAY NIGHT.
SUNDAY BEGINS SEVERAL DAYS OF MODERATION TO MORE COMFORTABLE
WEATHER...WITH HIGHS REACHING THE MID 50S WITH PLENTY OF SUN...THEN
AFTER A COOL NIGHT IN THE 30S...MONDAY SHOULD SEE A RETURN TO THE
LOWER 60S. UNFORTUNATELY...THIS WARMTH WILL ARRIVE WITH STRONGER
WINDS...THUS SENSIBLE WEATHER WILL BE PRETTY BRISK OUT THERE.
TUESDAY...A PASSING WAVE IN NORTHWEST FLOW SHOULD KEEP US MILD
AGAIN...WITH A CHANCE FOR RAIN SHOWERS. MODELS INDICATE THAT GOOD
MOISTURE MAY BE NEAR OR JUST PASS SOUTH OF THE CWA. SO...WHILE
CHANCE ARE INCREASED FROM PRIOR FORECASTS...THE AMOUNTS MAY BE QUITE
LIGHT. AFTER TUESDAY...MORE DRY WEATHER WITH CANADIAN HIGH PRESSURE
IS IN STORE FOR WEDNESDAY AND THURSDAY. LOWS IN THE 30S AND HIGHS IN
THE 50S WED/60S THU ARE EXPECTED.
ERVIN
CLIMATE...
RECORD LOWS FOR OCTOBER 7...
MOLINE.........27 IN 1952
CEDAR RAPIDS...25 IN 2001
DUBUQUE........23 IN 2000
BURLINGTON.....26 IN 1952
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1040 AM EDT FRI OCT 5 2012
.UPDATE...
AS OF 14Z...THE POST FRONTAL SHOWERS/THUNDERSTORMS EXTEND FROM S
CNTL MO TO W CNTL LAKE ERIE. THE SHOWERS HAVE REMAINED SOUTH OF
THE FORECAST AREA THIS MORNING AND RECENT RADAR TRENDS SUGGEST THE
FORECAST AREA WILL REMAIN DRY THROUGH AT LEAST EARLY AFTERNOON.
THE AMOUNT OF CONVECTION ALONG THE LOWER LEVELS OF THE FRONTAL
SLOPE /ROUGHLY IN THE 925-850MB LAYER/ HAS BEEN MORE EXTENSIVE
THAN EARLIER MODEL SOLUTIONS SUGGESTED DUE IN PART TO THE DEEP
LAYER OF CONVECTIVE INSTABILITY IN THIS REGION. THUS THE MID
LEVEL PORTIONS OF THE FRONT /WHICH EXTEND ACROSS SE MI/ HAVE THUS
FAR BEEN INACTIVE. SATELLITE DATA IS HOWEVER SHOWING A MID LEVEL
IMPULSE ROTATING INTO IOWA...FORECAST TO LIFT INTO LOWER MI THIS
EVENING. THE APPROACH OF THIS WAVE ALONG WITH AN INTENSIFICATION
OF AN UPPER LEVEL JET STREAK ADVANCING ACROSS THE NRN GREAT LAKES
THIS AFTERNOON SHOULD ENHANCE FRONTOGENESIS ALONG THE ELEVATED
FRONT /850-700MB LAYER/ DRAPED ACROSS SE MI. THIS FORCING IS NOT
EXPECTED TO ARRIVE IN SE MI UNTIL 21Z AND SHOULD PERSIST INTO AT
LEAST 03Z. WHILE THE BETTER CHANCES OF SHOWERS WILL OCCUR ALONG
AND SOUTH OF A BAD AXE TO OWOSSO LINE...THERE IS A POTENTIAL THAT
THE ELEVATED FRONT WILL BECOME MORE ACTIVE FARTHER NORTH...WHICH
WILL SUPPORT ADDING AT LEAST A CHANCE OF LATE DAY SHOWERS TO THE
TRI CITIES. WILL BE UPDATING THE FORECAST TO REFLECT THESE
CHANGES.
MEANWHILE...STRATO CU HAS BEEN DEVELOPING ACROSS SRN MI THIS
MORNING. THE 12Z DTX SOUNDING SHOWED A FAIRLY DEEP INVERSION BASED
NEAR 900MB...WITH AMPLE INSTABILITY BELOW TO ALLOW ENHANCEMENT TO
THE CLOUD FIELD OFF LAKE MICHIGAN. THIS WILL SUPPORT BOOSTING
CLOUD COVER A BIT AND KNOCKING A DEGREE OR TWO OFF AFTERNOON
HIGHS.
THE UPDATED ZFP AND GRIDS WILL BE ISSUED SHORTLY.
&&
.AVIATION...ISSUED 654 AM EDT FRI OCT 5 2012
//DISCUSSION...
WEST WINDS OF 10 TO 15 KNOTS WILL OCCASIONALLY GUST TO 20 KNOTS
TODAY, ESPECIALLY ACROSS NORTHERN AREAS WHERE DIURNAL HEATING IS
EXPECTED TO BE STRONGER. SHOWERS DEVELOPING UPSTREAM WILL SPREAD
INTO THE AREA THROUGH THE MORNING, REACHING THE DETROIT AIRFIELDS
BY EARLY THIS AFTERNOON. CEILINGS STAND A GOOD CHANCE OF FALLING
BELOW 5000 FEET AND POSSIBLY INTO THE MVFR RANGE WITH THIS
ACTIVITY. CONDITIONS WILL IMPROVE AS THE SHOWERS SHIFT EAST LATE
THIS EVENING. DEVELOPING NORTHWEST FLOW WILL RESULT IN LAKE CLOUD
DEVELOPMENT FOR SATURDAY.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5000 FEET BY LATE THIS MORNING
AND AGAIN BY LATE SATURDAY MORNING.
&&
.PREV DISCUSSION...ISSUED 356 AM EDT FRI OCT 5 2012
SHORT TERM...TODAY AND TONIGHT
NOW THAT THE SURFACE COLD FRONT HAS CLEARED THE AREA, MODERATE COLD
ADVECTION HAS BEGUN AND IS FORECAST TO CONTINUE WITH 850MB
TEMPERATURES FALLING TO SLIGHTLY BELOW ZERO BY 06Z TONIGHT. THE MOST
NOTEWORTHY CHANGE MADE TO TODAY`S FORECAST PACKAGE WAS TO TREND
TODAY`S HIGH TEMPERATURES DOWNWARD A COUPLE OF DEGREES. ALL
LOCATIONS STAND A GOOD CHANCE TO REMAIN IN THE 50S FOR THE BALANCE
OF THE DAY AS EARLY OCTOBER DIURNAL HEATING WILL HAVE TO CONTEND
WITH NOT ONLY WITH ONGOING COLD ADVECTION, BUT ALSO WIDESPREAD MID
AND UPPER CLOUDS. IN ADDITION, UPSTREAM LOCATIONS THAT SPENT THE
DAYTIME HOURS THURSDAY IN THE POST-FRONTAL ENVIRONMENT GENERALLY
ROSE INTO THE LOW 50S. AFTER GIVING CONSIDERATION TO THE HEAT
CONTRIBUTION FROM LAKE MICHIGAN, WHERE LAKE SFC TEMPS REMAIN IN THE
LOW 60S, HIGHS FOR TODAY WERE GIVEN A DOWNWARD ADJUSTMENT INTO THE
55-58 DEGREE RANGE. A FEW 60S STILL CAN`T BE RULED OUT SHOULD CLOUDS
BREAK DURING PEAK HEATING, MOST LIKELY NORTH OF M-59.
THE OTHER FORECAST ISSUE FOR TODAY IS THE PLACEMENT AND DURATION OF
A BAND OF SHOWERS THAT IS CURRENTLY TAKING SHAPE OVER MO/IL. WATER
VAPOR IMAGERY SHOWS AN ENERGETIC ZONAL FLOW ACROSS THE CENTRAL U.S.
WITH EMBEDDED LOW AMPLITUDE SHORTWAVES PROPAGATING ACROSS THE PLAINS
STATES. SHOWER COVERAGE IS EXPANDING AHEAD OF THIS ENERGY AND IN
ASSOCIATION WITH A DEVELOPING FGEN RESPONSE UNDER THE RIGHT ENTRANCE
OF A STRENGTHENING 90KT JET STREAK. THE 00Z GUIDANCE, IN PARTICULAR
THE NAM AND RECENT 3-KM HRRR SIMULATIONS, LOOK SOLID IN THEIR
REPRESENTATION OF THE DEVELOPING FRONTAL CIRCULATION AND ASSOCIATED
PRECIPITATION COVERAGE. FOR NOW, THE ONLY COMPLAINT IS THAT THE
RESPONSE WITHIN THE LOW STATIC STABILITY ENVIRONMENT LEADING THE
ARRIVAL OF THE JET CORE LOOKS HEALTHY, SO LEANED TOWARD AN EARLIER
12-13Z ARRIVAL TIME FOR SOUTHERN AREAS. THE NORTH SIDE OF THE PRECIP
SHIELD WILL INITIALLY CARRY THE SHARP CUTOFF EVIDENT ON THE REGIONAL
RADAR MOSAIC INTO THE AREA, CASTING SOME UNCERTAINTY ON ITS
NORTHWARD EXTENT AS IT STRADDLES THE METRO DETROIT AREA INTO THE
AFTERNOON. HOWEVER, ADDITIONAL NORTHWARD EXPANSION SEEMS PROBABLE
THIS AFTERNOON AS THE POTENT SHORTWAVE ENERGY OVER ID/WY AT 07Z
ACCELERATES TOWARD THE AREA LATER TODAY. LAKE CLOUDS WILL THEN BUILD
INTO THE AREA LATE TONIGHT COINCIDENT WITH THE APPROACH OF THE UPPER
TROUGH AXIS AND H85-SFC DELTA T VALUES PLUMMETING TO 20C OVER LM.
THE STAGE WILL THEN BE SET FOR A COLD START TO SATURDAY MORNING AS
LOW TEMPS DIP INTO THE MID TO UPPER 30S UNDERNEATH INCREASING
BOUNDARY LAYER SKY COVER.
LONG TERM...SATURDAY THROUGH THURSDAY
AS UPPER LOW SHIFTS JUST NORTH OF LAKE SUPERIOR IS PULLED NORTHEAST
INTO BROADER HUDSON BAY VORTEX...UPPER TROUGH AXIS WILL SWING ACROSS
LOWER MICHIGAN AND BRING A SECOND SHOT OF COLD AIR INTO THE AREA ON
SATURDAY. WITH H85 TEMPERATURES FALLING SOLIDLY BELOW 0C...EXPECT
HIGH TEMPERATURES TO REMAIN BETWEEN 50 AND 55. WHILE BEST LIFT AND
FORCING WITH THE VORTICITY CENTER ALONG THIS TROUGH WILL REMAIN TO
THE NORTH OF THE AREA...THERE WILL BE A SMALL CHANCE OF SHOWERS IN
THE 20-30% RANGE AS WRAPAROUND MOISTURE BRUSHES THE AREA AND LAKE
EFFECT ACTIVITY BEGINS TO EXPAND IN THE COLDER AIR.
AFTER ANOTHER DAY WITH HIGH TEMPERATURES AOB 55F ON SUNDAY (WITH
EARLY MORNING TEMPERATURES MOST LIKELY REACHING FREEZING IN SOME
LOCATIONS)...THE NEXT STRONG SHORTWAVE PIVOTING THROUGH THE NORTHERN
GREAT LAKES AROUND THE HUDSON VORTEX WILL BRING A MODERATING TREND
IN THE MONDAY AND TUESDAY TIME FRAME AS SOUTHWEST FLOW BECOMES
ESTABLISHED IN ADVANCE OF THE NEXT STRONG COLD FRONT WHICH WILL
SHIFT INTO THE AREA AS THIS SECOND NORTHERN STREAM STORM SYSTEM
WRAPS NORTHEAST INTO THE AFOREMENTIONED VORTEX. TEMPERATURES WILL
CLIMB WELL INTO THE 50S ON MONDAY AND TO 60 OR BETTER ON TUESDAY AS
THE ARRIVAL OF THIS COLD FRONT IS DELAYED SLIGHTLY AS LOW PRESSURE
RIPPLES UP ALONG IT.
THIS SOUTHERN STREAM LOW PRESSURE WILL BRING THE BEST CHANCE OF
RAINFALL IN THE EXTENDED PORTION OF THE FORECAST AS STRONG FORCING
SHIFTS THROUGH THE AREA WITH THIS PASSAGE OF THIS SYSTEM TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING...WITH ONLY MINOR LAKE EFFECT
ACTIVITY EXPECTED LATER WEDNESDAY INTO THURSDAY SOUTHEAST OF LAKE
HURON.
TEMPERATURES WILL COOL BACK INTO THE MID 50S ON WEDNESDAY...BUT WITH
NORTHERN STREAM SHORTWAVE TAKING A WESTERLY TRACK NORTH OF THE GREAT
LAKES...THE COLDEST AIR WITH THIS SYSTEM WILL REMAIN OVER CANADA AND
EXPECT TEMPERATURES TO REBOUND TO THE UPPER 50S TO AROUND 60 BY
THURSDAY.
MARINE...
A FRESH WEST-SOUTHWEST BREEZE WILL GUST INTO THE 25 TO 30 KNOT RANGE
TODAY AS A COOL AND UNSTABLE AIRMASS OVERSPREADS AREA WATERS. A FEW
GUSTS TO LOW END GALE FORCE WILL BE POSSIBLE FROM OUTER SAGINAW BAY
INTO CENTRAL LAKE HURON THIS AFTERNOON...BUT NO ORGANIZED OR
WIDESPREAD GALES ARE EXPECTED. WINDS WILL GRADUALLY EASE BY LATE
FRIDAY NIGHT BUT WAVES WILL REMAIN REMAIN ELEVATED INTO SATURDAY
MORNING. ALL SMALL CRAFT ADVISORIES THEREFORE REMAIN IN EFFECT FOR
SAGINAW BAY AND THE NEARSHORE FROM PORT AUSTIN TO HARBOR BEACH UNTIL
SATURDAY MORNING. A RENEWED SURGE OF GUSTY WINDS WILL DEVELOP AHEAD
OF ANOTHER PUSH OF COLD AIR ON SATURDAY. A BRIEF REPRIEVE CAN BE
EXPECTED ON SUNDAY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE
AREA...BUT UNSETTLED CONDITIONS WILL QUICKLY REDEVELOP AS THE
SURFACE PRESSURE GRADIENT STRENGTHENS EARLY NEXT WEEK. SOUTH WINDS
WILL INCREASE TO 20 TO 25 KNOTS BY LATE MONDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
PORT AUSTIN TO HARBOR BEACH...UNTIL 8 AM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SC
AVIATION.....DG
SHORT TERM...JVC
LONG TERM....DG
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
654 AM EDT FRI OCT 5 2012
.AVIATION...
//DISCUSSION...
WEST WINDS OF 10 TO 15 KNOTS WILL OCCASIONALLY GUST TO 20 KNOTS
TODAY, ESPECIALLY ACROSS NORTHERN AREAS WHERE DIURNAL HEATING IS
EXPECTED TO BE STRONGER. SHOWERS DEVELOPING UPSTREAM WILL SPREAD
INTO THE AREA THROUGH THE MORNING, REACHING THE DETROIT AIRFIELDS
BY EARLY THIS AFTERNOON. CEILINGS STAND A GOOD CHANCE OF FALLING
BELOW 5000 FEET AND POSSIBLY INTO THE MVFR RANGE WITH THIS
ACTIVITY. CONDITIONS WILL IMPROVE AS THE SHOWERS SHIFT EAST LATE
THIS EVENING. DEVELOPING NORTHWEST FLOW WILL RESULT IN LAKE CLOUD
DEVELOPMENT FOR SATURDAY.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5000 FEET BY LATE THIS MORNING
AND AGAIN BY LATE SATURDAY MORNING.
&&
.PREV DISCUSSION...ISSUED 356 AM EDT FRI OCT 5 2012
SHORT TERM...TODAY AND TONIGHT
NOW THAT THE SURFACE COLD FRONT HAS CLEARED THE AREA, MODERATE COLD
ADVECTION HAS BEGUN AND IS FORECAST TO CONTINUE WITH 850MB
TEMPERATURES FALLING TO SLIGHTLY BELOW ZERO BY 06Z TONIGHT. THE MOST
NOTEWORTHY CHANGE MADE TO TODAY`S FORECAST PACKAGE WAS TO TREND
TODAY`S HIGH TEMPERATURES DOWNWARD A COUPLE OF DEGREES. ALL
LOCATIONS STAND A GOOD CHANCE TO REMAIN IN THE 50S FOR THE BALANCE
OF THE DAY AS EARLY OCTOBER DIURNAL HEATING WILL HAVE TO CONTEND
WITH NOT ONLY WITH ONGOING COLD ADVECTION, BUT ALSO WIDESPREAD MID
AND UPPER CLOUDS. IN ADDITION, UPSTREAM LOCATIONS THAT SPENT THE
DAYTIME HOURS THURSDAY IN THE POST-FRONTAL ENVIRONMENT GENERALLY
ROSE INTO THE LOW 50S. AFTER GIVING CONSIDERATION TO THE HEAT
CONTRIBUTION FROM LAKE MICHIGAN, WHERE LAKE SFC TEMPS REMAIN IN THE
LOW 60S, HIGHS FOR TODAY WERE GIVEN A DOWNWARD ADJUSTMENT INTO THE
55-58 DEGREE RANGE. A FEW 60S STILL CAN`T BE RULED OUT SHOULD CLOUDS
BREAK DURING PEAK HEATING, MOST LIKELY NORTH OF M-59.
THE OTHER FORECAST ISSUE FOR TODAY IS THE PLACEMENT AND DURATION OF
A BAND OF SHOWERS THAT IS CURRENTLY TAKING SHAPE OVER MO/IL. WATER
VAPOR IMAGERY SHOWS AN ENERGETIC ZONAL FLOW ACROSS THE CENTRAL U.S.
WITH EMBEDDED LOW AMPLITUDE SHORTWAVES PROPAGATING ACROSS THE PLAINS
STATES. SHOWER COVERAGE IS EXPANDING AHEAD OF THIS ENERGY AND IN
ASSOCIATION WITH A DEVELOPING FGEN RESPONSE UNDER THE RIGHT ENTRANCE
OF A STRENGTHENING 90KT JET STREAK. THE 00Z GUIDANCE, IN PARTICULAR
THE NAM AND RECENT 3-KM HRRR SIMULATIONS, LOOK SOLID IN THEIR
REPRESENTATION OF THE DEVELOPING FRONTAL CIRCULATION AND ASSOCIATED
PRECIPITATION COVERAGE. FOR NOW, THE ONLY COMPLAINT IS THAT THE
RESPONSE WITHIN THE LOW STATIC STABILITY ENVIRONMENT LEADING THE
ARRIVAL OF THE JET CORE LOOKS HEALTHY, SO LEANED TOWARD AN EARLIER
12-13Z ARRIVAL TIME FOR SOUTHERN AREAS. THE NORTH SIDE OF THE PRECIP
SHIELD WILL INITIALLY CARRY THE SHARP CUTOFF EVIDENT ON THE REGIONAL
RADAR MOSAIC INTO THE AREA, CASTING SOME UNCERTAINTY ON ITS
NORTHWARD EXTENT AS IT STRADDLES THE METRO DETROIT AREA INTO THE
AFTERNOON. HOWEVER, ADDITIONAL NORTHWARD EXPANSION SEEMS PROBABLE
THIS AFTERNOON AS THE POTENT SHORTWAVE ENERGY OVER ID/WY AT 07Z
ACCELERATES TOWARD THE AREA LATER TODAY. LAKE CLOUDS WILL THEN BUILD
INTO THE AREA LATE TONIGHT COINCIDENT WITH THE APPROACH OF THE UPPER
TROUGH AXIS AND H85-SFC DELTA T VALUES PLUMMETING TO 20C OVER LM.
THE STAGE WILL THEN BE SET FOR A COLD START TO SATURDAY MORNING AS
LOW TEMPS DIP INTO THE MID TO UPPER 30S UNDERNEATH INCREASING
BOUNDARY LAYER SKY COVER.
LONG TERM...SATURDAY THROUGH THURSDAY
AS UPPER LOW SHIFTS JUST NORTH OF LAKE SUPERIOR IS PULLED NORTHEAST
INTO BROADER HUDSON BAY VORTEX...UPPER TROUGH AXIS WILL SWING ACROSS
LOWER MICHIGAN AND BRING A SECOND SHOT OF COLD AIR INTO THE AREA ON
SATURDAY. WITH H85 TEMPERATURES FALLING SOLIDLY BELOW 0C...EXPECT
HIGH TEMPERATURES TO REMAIN BETWEEN 50 AND 55. WHILE BEST LIFT AND
FORCING WITH THE VORTICITY CENTER ALONG THIS TROUGH WILL REMAIN TO
THE NORTH OF THE AREA...THERE WILL BE A SMALL CHANCE OF SHOWERS IN
THE 20-30% RANGE AS WRAPAROUND MOISTURE BRUSHES THE AREA AND LAKE
EFFECT ACTIVITY BEGINS TO EXPAND IN THE COLDER AIR.
AFTER ANOTHER DAY WITH HIGH TEMPERATURES AOB 55F ON SUNDAY (WITH
EARLY MORNING TEMPERATURES MOST LIKELY REACHING FREEZING IN SOME
LOCATIONS)...THE NEXT STRONG SHORTWAVE PIVOTING THROUGH THE NORTHERN
GREAT LAKES AROUND THE HUDSON VORTEX WILL BRING A MODERATING TREND
IN THE MONDAY AND TUESDAY TIME FRAME AS SOUTHWEST FLOW BECOMES
ESTABLISHED IN ADVANCE OF THE NEXT STRONG COLD FRONT WHICH WILL
SHIFT INTO THE AREA AS THIS SECOND NORTHERN STREAM STORM SYSTEM
WRAPS NORTHEAST INTO THE AFOREMENTIONED VORTEX. TEMPERATURES WILL
CLIMB WELL INTO THE 50S ON MONDAY AND TO 60 OR BETTER ON TUESDAY AS
THE ARRIVAL OF THIS COLD FRONT IS DELAYED SLIGHTLY AS LOW PRESSURE
RIPPLES UP ALONG IT.
THIS SOUTHERN STREAM LOW PRESSURE WILL BRING THE BEST CHANCE OF
RAINFALL IN THE EXTENDED PORTION OF THE FORECAST AS STRONG FORCING
SHIFTS THROUGH THE AREA WITH THIS PASSAGE OF THIS SYSTEM TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING...WITH ONLY MINOR LAKE EFFECT
ACTIVITY EXPECTED LATER WEDNESDAY INTO THURSDAY SOUTHEAST OF LAKE
HURON.
TEMPERATURES WILL COOL BACK INTO THE MID 50S ON WEDNESDAY...BUT WITH
NORTHERN STREAM SHORTWAVE TAKING A WESTERLY TRACK NORTH OF THE GREAT
LAKES...THE COLDEST AIR WITH THIS SYSTEM WILL REMAIN OVER CANADA AND
EXPECT TEMPERATURES TO REBOUND TO THE UPPER 50S TO AROUND 60 BY
THURSDAY.
MARINE...
A FRESH WEST-SOUTHWEST BREEZE WILL GUST INTO THE 25 TO 30 KNOT RANGE
TODAY AS A COOL AND UNSTABLE AIRMASS OVERSPREADS AREA WATERS. A FEW
GUSTS TO LOW END GALE FORCE WILL BE POSSIBLE FROM OUTER SAGINAW BAY
INTO CENTRAL LAKE HURON THIS AFTERNOON...BUT NO ORGANIZED OR
WIDESPREAD GALES ARE EXPECTED. WINDS WILL GRADUALLY EASE BY LATE
FRIDAY NIGHT BUT WAVES WILL REMAIN REMAIN ELEVATED INTO SATURDAY
MORNING. ALL SMALL CRAFT ADVISORIES THEREFORE REMAIN IN EFFECT FOR
SAGINAW BAY AND THE NEARSHORE FROM PORT AUSTIN TO HARBOR BEACH UNTIL
SATURDAY MORNING. A RENEWED SURGE OF GUSTY WINDS WILL DEVELOP AHEAD
OF ANOTHER PUSH OF COLD AIR ON SATURDAY. A BRIEF REPRIEVE CAN BE
EXPECTED ON SUNDAY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE
AREA...BUT UNSETTLED CONDITIONS WILL QUICKLY REDEVELOP AS THE
SURFACE PRESSURE GRADIENT STRENGTHENS EARLY NEXT WEEK. SOUTH WINDS
WILL INCREASE TO 20 TO 25 KNOTS BY LATE MONDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
PORT AUSTIN TO HARBOR BEACH...UNTIL 8 AM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DG
SHORT TERM...JVC
LONG TERM....DG
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
643 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A CANADIAN COLD FRONT...WILL MOVE SOUTHEASTWARD THROUGH THE UPPER
OHIO VALLEY TONIGHT...AND BRING SHOWERS AND MUCH COOLER
TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
MINOR ADJUSTMENTS TO EVE UPDATE. SOME TIMING CHANGES TO OVERNIGHT
POPS AND ADJUSTED TEMPS CLOSER TO LATEST GUIDANCE.
PREVIOUS DISCUSSION...
JUDGING FROM BLEND OF RECENT SURFACE...RADAR AND SATELLITE
DATA...COUPLED WITH RECENT WRF-NMM AND RAP MODEL OUTPUT...CONTINUE
TO EXPECT THE MAIN ADIABATIC COLD FRONTAL BAND OF SHOWERS TO MOVE
SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY LATE TONIGHT INTO
SATURDAY MORNING.
HOWEVER...MODEL OUTPUT CONTINUES TO SUGGEST THERE CAN BE A THIN
BAND OF SCATTERED PREFRONTAL SHOWERS DEVELOPING ACROSS THE UPPER
OHIO VALLEY THIS EVENING. EVEN IF SO PRECIPITATION AMOUNTS WOULD
BE LIGHT. CONCUR WITH HPC QPF THAT RAIN AMOUNTS LATE TONIGHT INTO
SATURDAY MORNING CAN BE UP TO 0.25 INCHES.
FORECASTED TEMPERATURES...PER RECENT GFS AND NAM MOS...TO BECOME
NOTICEABLY COLDER WITH LOWS TONIGHT DOWN TO NEAR NORMAL WITH HIGHS
SATURDAY ABOUT 10 DEGREES COLDER THAN NORMAL.
DUE TO SHALLOW BUT VIGOROUS VERTICAL MIXING IN WAKE OF THE COLD
FRONTAL PASSAGE...WIND MAY GUST UP TO 20 TO 25 MPH THROUGH DAYTIME
SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MORE RECENT SREF MODEL OUTPUT SHOW THE ENSUING LOW PRESSURE WAVE
ALONG THE EXITED COLD FRONT WILL AT MOST ONLY MAINLY AFFECT WV-MD
MOUNTAINS SATURDAY NIGHT AND SUNDAY. HOWEVER...THE COLD UPPER
TROUGH WILL MAINTAIN CLOUDY SKIES INTO MONDAY...AND MAY PROMOTE
SCATTERED INSTABILITY SHOWERS LATE SUNDAY ACROSS MAINLY WESTERN
PENNSYLVANIA.
DUE TO THE COLDNESS OF THE SURFACE LAYER...ITS POSSIBLE HIGHER
ELEVATIONS MAY SEE A CHANGE TO LIGHT SNOW SHOWERS AT TIMES...BUT
THE GROUND WILL REMAIN TOO WARM FOR ANY IMPACT.
FORECASTED SPECIFIC TEMPERATURES USING BLEND OF GFS NAM AND ECMWF
MOS...THAT SHOWED VALUES GENERALLY 7 TO 10 DEGREES COLDER THAN
NORMAL...WITH HIGHS SUNDAY PERHAPS 10 TO 13 DEGREES COLDER THAN
NORMAL.
ALTHOUGH MOST LOW TEMPERATURES SUNDAY NIGHT WILL BE IN THE LOWER
TO MID 30S...FROST AND FREEZE PROSPECTS WILL DEPEND REMAINING
EXTENT OF CLOUD COVER AND WIND...SO HELD OFF ON ANY CORRESPONDING
ISSUANCES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE EXTENDED PERIOD BEGINS WITH HIGH PRESSURE RIDGE ALONG MUCH OF
THE EASTERN UNITED STATES...WHICH SHOULD PERSIST FROM MONDAY NIGHT
INTO TUESDAY NIGHT.
LOW PRESSURE IS THEN EXPECTED TO MOVE EAST FROM LAKE
HURON...SKIRTING THE U.S.-CANADA BORDER. THE LOW SHOULD BRING A
COLD FRONT THROUGH THE REGION ON WEDNESDAY. FOR NOW HAVE STUCK
WITH CHANCE POPS DURING THE DAYTIME. THE FRONT SHOULD DROP
TEMPERATURES ABOUT 5 DEGREES FROM THE PREVIOUS DAYS READING.
HIGH PRESSURE WILL THEN RETURN WEDNESDAY NIGHT AND REMAIN ACROSS
THE SOUTHEASTERN UNITED STATES THURSDAY. ANOTHER CANADIAN LOW
SHOULD SWEEP A SECOND COLD FRONT THROUGH THURSDAY NIGHT INTO
FRIDAY. THIS SHOULD BRING AT LEAST A SLIGHT CHANCE OF SHOWERS
DURING THAT TIME PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
EXPECT BROKEN LOW VFR CIGS IN DIURNAL CUMULUS THIS AFTERNOON...WITH
SW GUSTS UP TO 15-20 KTS POSSIBLE.
BY SUNSET STRATUS DECK SHOULD BE MOVING IN FROM THE WEST. THE
STRATUS SHOULD PROVIDE VFR CEILINGS...EVENTUALLY DROPPING TO MVFR
CIGS AS RAIN MOVES IN AROUND MIDNIGHT. DROPPED CIGS DOWN TO 1KFT
AT FKL AND DUJ...BUT NOT ENOUGH CONFIDENCE TO GO IFR AT THIS
POINT. WITH RAIN EXPECTED TO FALL PRIMARILY BEHIND THE COLD
FRONT...EXPECT WIND SHIFT BEFORE RAIN BEGINS TO FALL. WINDS WILL
SHIFT TO THE WEST AND INCREASE AS WIDESPREAD RAIN ENDS SATURDAY
MORNING...WITH CIGS REMAINING AT A VFR LEVEL.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
WIDESPREAD LOW VFR/HIGH MVFR CIGS CAN BE EXPECTED ALONG WITH
SCATTERED SHOWERS SATURDAY NIGHT INTO SUNDAY. VFR CAN BE EXPECTED
SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A COLD FRONT BRINGS
POSSIBLE RESTRICTIONS IN SHOWERS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
350 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A CANADIAN COLD FRONT...WILL MOVE SOUTHEASTWARD THROUGH THE UPPER
OHIO VALLEY TONIGHT...AND BRING SHOWERS AND MUCH COOLER
TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
JUDGING FROM BLEND OF RECENT SURFACE...RADAR AND SATELLITE
DATA...COUPLED WITH RECENT WRF-NMM AND RAP MODEL OUTPUT...CONTINUE
TO EXPECT THE MAIN ADIABATIC COLD FRONTAL BAND OF SHOWERS TO MOVE
SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY LATE TONIGHT INTO
SATURDAY MORNING.
HOWEVER...MODEL OUTPUT CONTINUES TO SUGGEST THERE CAN BE A THIN
BAND OF SCATTERED PREFRONTAL SHOWERS DEVELOPING ACROSS THE UPPER
OHIO VALLEY THIS EVENING. EVEN IF SO PRECIPITATION AMOUNTS WOULD
BE LIGHT. CONCUR WITH HPC QPF THAT RAIN AMOUNTS LATE TONIGHT INTO
SATURDAY MORNING CAN BE UP TO 0.25 INCHES.
FORECASTED TEMPERATURES...PER RECENT GFS AND NAM MOS...TO BECOME
NOTICEABLY COLDER WITH LOWS TONIGHT DOWN TO NEAR NORMAL WITH HIGHS
SATURDAY ABOUT 10 DEGREES COLDER THAN NORMAL.
DUE TO SHALLOW BUT VIGOROUS VERTICAL MIXING IN WAKE OF THE COLD
FRONTAL PASSAGE...WIND MAY GUST UP TO 20 TO 25 MPH THROUGH DAYTIME
SATURDAY.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
MORE RECENT SREF MODEL OUTPUT SHOW THE ENSUING LOW PRESSURE WAVE
ALONG THE EXITED COLD FRONT WILL AT MOST ONLY MAINLY AFFECT WV-MD
MOUNTAINS SATURDAY NIGHT AND SUNDAY. HOWEVER...THE COLD UPPER
TROUGH WILL MAINTAIN CLOUDY SKIES INTO MONDAY...AND MAY PROMOTE
SCATTERED INSTABILITY SHOWERS LATE SUNDAY ACROSS MAINLY WESTERN
PENNSYLVANIA.
DUE TO THE COLDNESS OF THE SURFACE LAYER...ITS POSSIBLE HIGHER
ELEVATIONS MAY SEE A CHANGE TO LIGHT SNOW SHOWERS AT TIMES...BUT
THE GROUND WILL REMAIN TOO WARM FOR ANY IMPACT.
FORECASTED SPECIFIC TEMPERATURES USING BLEND OF GFS NAM AND ECMWF
MOS...THAT SHOWED VALUES GENERALLY 7 TO 10 DEGREES COLDER THAN
NORMAL...WITH HIGHS SUNDAY PERHAPS 10 TO 13 DEGREES COLDER THAN
NORMAL.
ALTHOUGH MOST LOW TEMPERATURES SUNDAY NIGHT WILL BE IN THE LOWER
TO MID 30S...FROST AND FREEZE PROSPECTS WILL DEPEND REMAINING
EXTENT OF CLOUD COVER AND WIND...SO HELD OFF ON ANY CORRESPONDING
ISSUANCES.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE EXTENDED PERIOD BEGINS WITH HIGH PRESSURE RIDGE ALONG MUCH OF
THE EASTERN UNITED STATES...WHICH SHOULD PERSIST FROM MONDAY NIGHT
INTO TUESDAY NIGHT.
LOW PRESSURE IS THEN EXPECTED TO MOVE EAST FROM LAKE
HURON...SKIRTING THE U.S.-CANADA BORDER. THE LOW SHOULD BRING A
COLD FRONT THROUGH THE REGION ON WEDNESDAY. FOR NOW HAVE STUCK
WITH CHANCE POPS DURING THE DAYTIME. THE FRONT SHOULD DROP
TEMPERATURES ABOUT 5 DEGREES FROM THE PREVIOUS DAYS READING.
HIGH PRESSURE WILL THEN RETURN WEDNESDAY NIGHT AND REMAIN ACROSS
THE SOUTHEASTERN UNITED STATES THURSDAY. ANOTHER CANADIAN LOW
SHOULD SWEEP A SECOND COLD FRONT THROUGH THURSDAY NIGHT INTO
FRIDAY. THIS SHOULD BRING AT LEAST A SLIGHT CHANCE OF SHOWERS
DURING THAT TIME PERIOD.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
EXPECT BROKEN LOW VFR CIGS IN DIURNAL CUMULUS THIS AFTERNOON...WITH
SW GUSTS UP TO 15-20 KTS POSSIBLE.
BY SUNSET STRATUS DECK SHOULD BE MOVING IN FROM THE WEST. THE
STRATUS SHOULD PROVIDE VFR CEILINGS...EVENTUALLY DROPPING TO MVFR
CIGS AS RAIN MOVES IN AROUND MIDNIGHT. DROPPED CIGS DOWN TO 1KFT
AT FKL AND DUJ...BUT NOT ENOUGH CONFIDENCE TO GO IFR AT THIS
POINT. WITH RAIN EXPECTED TO FALL PRIMARILY BEHIND THE COLD
FRONT...EXPECT WIND SHIFT BEFORE RAIN BEGINS TO FALL. WINDS WILL
SHIFT TO THE WEST AND INCREASE AS WIDESPREAD RAIN ENDS SATURDAY
MORNING...WITH CIGS REMAINING AT A VFR LEVEL.
.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
WIDESPREAD LOW VFR/HIGH MVFR CIGS CAN BE EXPECTED ALONG WITH
SCATTERED SHOWERS SATURDAY NIGHT INTO SUNDAY. VFR CAN BE EXPECTED
SUNDAY NIGHT THROUGH TUESDAY NIGHT BEFORE A COLD FRONT BRINGS
POSSIBLE RESTRICTIONS IN SHOWERS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1205 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A CANADIAN COLD FRONT...WILL MOVE SOUTHEASTWARD THROUGH THE UPPER
OHIO VALLEY TONIGHT...AND BRING SHOWERS AND MUCH COOLER
TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH SATURDAY/...
JUDGING FROM BLEND OF RECENT RADAR AND SATELLITE DATA...EXPECT
SKIES TO REMAIN FAIRLY SUNNY THIS AFTERNOON. SURFACE DATA SHOWS
TEMPERATURES CORRESPONDINGLY CLIMBING...SO HAVE CONTINUED FORECAST
OF HIGHS THIS AFTERNOON GENERALLY 10 DEGREES WARMER THAN
NORMAL...WHICH CONCURS WITH RECENT GFS LAMP AND HRRR MODEL OUTPUT.
PER BLEND OF RECENT HIGH-RESOLUTION MODEL OUTPUT...PARTICULARLY
WRF-NMM AND WRF-ARW...SHOW COLD ANAFRONTAL BAND OF SHOWERS PASSING
SOUTHEASTWARD THROUGH THE UPPER OHIO VALLEY...MAINLY LATE TONIGHT
INTO SATURDAY MORNING.
FORECASTED TEMPERATURES...PER RECENT GFS AND NAM MOS...TO BECOME
NOTICEABLY COLDER WITH LOWS TONIGHT NEAR NORMAL BUT HIGHS SATURDAY
ABOUT 10 DEGREES COLDER THAN NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
FRONT WILL CONTINUE ITS PROGRESSION ACROSS THE REGION BRINGING A
GOOD CHANCE FOR RAIN THROUGH SATURDAY AFTERNOON. MODELS CONTINUE
TO STALL THE FRONT SOMEWHERE ALONG THE MASON-DIXON LINE SATURDAY
NIGHT BEFORE ANOTHER SHORTWAVE FINALLY PUSHES IT COMPLETELY SOUTH
AND EAST. DECIDED TO CUT BACK POPS FOR THE SATURDAY NIGHT PERIOD
THOUGH SOME POST FRONTAL SHOWERS COULD BE POSSIBLE IN NORTHWEST
FLOW AND COOLING 850 TEMPERATURES.
THE NEWEST MODEL RUNS ARE STARTING TO AGREE BETTER ON STRONGER
SECONDARY SHORTWAVE EXPECTED TO CROSS THE OHIO VALLEY SUNDAY. THE
ECMWF IS THE SLOWEST AND FURTHER NORTH WITH THE EXTENT OF PRECIP
BUT EVEN WITH THE MORE SOUTHERLY GFS...NORTHWESTERLY FLOW BEHIND
THE WAVE WOULD ONCE AGAIN BRING PRECIPITATION FOR MUCH OF THE AREA
SUNDAY AFTERNOON. WILL KEEP CHANCE POPS FOR MUCH OF THE AREA WITH
LIKELYS ON THE RIDGES. WEST/NORTHWEST UPPER LEVEL FLOW WILL
PERSIST AFTER PASSAGE OF THE SHORTWAVE MAINTAINING THE CHANCE FOR
SHOWERS AND EVEN A FEW SNOW SHOWERS IN THE HIGHER ELEVATIONS AND
POINTS NORTH OF I-80 SUNDAY NIGHT AS 850HPA TEMPERATURES REMAIN AT
-2C.
STRONG COLD ADVECTION WITH THE PASSAGE OF THE FRONT AND SECONDARY
SHORTWAVE WILL KEEP TEMPERATURES 5-10 DEGREES BELOW NORMAL THROUGH
MONDAY. HIGH PRESSURE RIDGE AND BACKING WINDS WILL CUT OFF
PRECIPITATION LATE SUNDAY NIGHT BRINGING THE POSSIBILITY OF A
FREEZE IN SOME COUNTIES BY DAYBREAK. BUT...WITH UNCERTAINTY IN
THE AMOUNT OF CLOUD COVER WILL LEAVE OUT MENTION IN FORECAST FOR
NOW.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN IN CONTROL TUESDAY...HELPING TO MODERATE
TEMPERATURES TO CLOSER TO NORMAL VALUES. A SOUTHEASTBOUND CANADIAN
COLD FRONT WILL PROVIDE A CHANCE OF SHOWERS TUESDAY NIGHT AND
WEDNESDAY.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
VFR IS FORECAST THROUGH THIS AFTN AS SWLY FLOW DVLPS IN ADVN OF A
CDFNT SLOWLY MOVING ACRS THE MIDWEST.
.OUTLOOK.../TONIGHT THROUGH TUESDAY/...
RESTRICTION POTENTIAL WL INCRS ON THIS EVE AS THE FRONT AND SHRA MOVE
OVR THE UPR OH VALLEY REGION. WIDESPREAD MVFR STRATOCU AND
PERIODIC SHRA CAN BE EXPECTED IN THE STRONG COLD ADVCTN REGIME
BEHIND THE FRONT. VFR IS EXPECTED TO RTN WITH MONDAY HIGH PRES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1256 PM EDT FRI OCT 5 2012
.AVIATION...
//DISCUSSION...
SHALLOW POST FRONTAL COLD AIR ADVECTION LED TO THE DEVELOPMENT OF
SOME MVFR BASED STRATUS THIS MORNING. THERE IS ENOUGH DRY AIR MIXING
INTO THE INVERSION THAT THESE CLOUDS HAVE BEEN DECREASING IN
COVERAGE...WHILE CONTINUED LOW LEVEL COLD AIR ADVECTION AND DAYTIME
HEATING LIFT INVERSION BASES. A REGION OF SHOWERS ACROSS NORTH
CENTRAL IL AND SRN IOWA WILL LIFT INTO SE MI THIS AFTERNOON...
PRIMARILY AFTER 21Z. THIS FORCING SHOULD PERSIST THROUGH ROUGHLY 03Z
BEFORE MOVING OFF TO THE EAST. PATCHES OF STRATO CU SHOULD PERSIST
WELL THROUGH THE NIGHT UNDER CONTINUED LOW LEVEL COLD AIR ADVECTION.
THE INCREASING DEPTH OF COLD AIR SHOULD HOWEVER KEEP BASES ABOVE
3000 FT.
FOR DTW...AT LEAST SOME PATCHES OF RAIN ARE EXPECTED TO TRAVERSE
METRO THIS EVENING. BEING A LITTLE CLOSER TO THE SFC COLD
FRONT...INVERSION BASES AND THUS CEILING HEIGHTS WILL LIKELY BE A
TOUCH LOWER THAN LOCATIONS FARTHER NORTH...POSSIBLY FALLING IN THE
3500 TO 4500 FT RANGE. CONFIDENCE ON CEILING HEIGHTS HOWEVER IS
RATHER LOW GIVEN SOME ONGOING ENTRAINMENT OF DRY AIR.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILING HEIGHTS BELOW 5000 FT TODAY AND TONIGHT.
&&
.PREV DISCUSSION...ISSUED 1040 AM EDT FRI OCT 5 2012
UPDATE...
AS OF 14Z...THE POST FRONTAL SHOWERS/THUNDERSTORMS EXTEND FROM S
CNTL MO TO W CNTL LAKE ERIE. THE SHOWERS HAVE REMAINED SOUTH OF
THE FORECAST AREA THIS MORNING AND RECENT RADAR TRENDS SUGGEST THE
FORECAST AREA WILL REMAIN DRY THROUGH AT LEAST EARLY AFTERNOON.
THE AMOUNT OF CONVECTION ALONG THE LOWER LEVELS OF THE FRONTAL
SLOPE /ROUGHLY IN THE 925-850MB LAYER/ HAS BEEN MORE EXTENSIVE
THAN EARLIER MODEL SOLUTIONS SUGGESTED DUE IN PART TO THE DEEP
LAYER OF CONVECTIVE INSTABILITY IN THIS REGION. THUS THE MID
LEVEL PORTIONS OF THE FRONT /WHICH EXTEND ACROSS SE MI/ HAVE THUS
FAR BEEN INACTIVE. SATELLITE DATA IS HOWEVER SHOWING A MID LEVEL
IMPULSE ROTATING INTO IOWA...FORECAST TO LIFT INTO LOWER MI THIS
EVENING. THE APPROACH OF THIS WAVE ALONG WITH AN INTENSIFICATION
OF AN UPPER LEVEL JET STREAK ADVANCING ACROSS THE NRN GREAT LAKES
THIS AFTERNOON SHOULD ENHANCE FRONTOGENESIS ALONG THE ELEVATED
FRONT /850-700MB LAYER/ DRAPED ACROSS SE MI. THIS FORCING IS NOT
EXPECTED TO ARRIVE IN SE MI UNTIL 21Z AND SHOULD PERSIST INTO AT
LEAST 03Z. WHILE THE BETTER CHANCES OF SHOWERS WILL OCCUR ALONG
AND SOUTH OF A BAD AXE TO OWOSSO LINE...THERE IS A POTENTIAL THAT
THE ELEVATED FRONT WILL BECOME MORE ACTIVE FARTHER NORTH...WHICH
WILL SUPPORT ADDING AT LEAST A CHANCE OF LATE DAY SHOWERS TO THE
TRI CITIES. WILL BE UPDATING THE FORECAST TO REFLECT THESE
CHANGES.
MEANWHILE...STRATO CU HAS BEEN DEVELOPING ACROSS SRN MI THIS
MORNING. THE 12Z DTX SOUNDING SHOWED A FAIRLY DEEP INVERSION BASED
NEAR 900MB...WITH AMPLE INSTABILITY BELOW TO ALLOW ENHANCEMENT TO
THE CLOUD FIELD OFF LAKE MICHIGAN. THIS WILL SUPPORT BOOSTING
CLOUD COVER A BIT AND KNOCKING A DEGREE OR TWO OFF AFTERNOON
HIGHS.
THE UPDATED ZFP AND GRIDS WILL BE ISSUED SHORTLY.
PREV DISCUSSION...ISSUED 356 AM EDT FRI OCT 5 2012
SHORT TERM...TODAY AND TONIGHT
NOW THAT THE SURFACE COLD FRONT HAS CLEARED THE AREA, MODERATE COLD
ADVECTION HAS BEGUN AND IS FORECAST TO CONTINUE WITH 850MB
TEMPERATURES FALLING TO SLIGHTLY BELOW ZERO BY 06Z TONIGHT. THE MOST
NOTEWORTHY CHANGE MADE TO TODAY`S FORECAST PACKAGE WAS TO TREND
TODAY`S HIGH TEMPERATURES DOWNWARD A COUPLE OF DEGREES. ALL
LOCATIONS STAND A GOOD CHANCE TO REMAIN IN THE 50S FOR THE BALANCE
OF THE DAY AS EARLY OCTOBER DIURNAL HEATING WILL HAVE TO CONTEND
WITH NOT ONLY WITH ONGOING COLD ADVECTION, BUT ALSO WIDESPREAD MID
AND UPPER CLOUDS. IN ADDITION, UPSTREAM LOCATIONS THAT SPENT THE
DAYTIME HOURS THURSDAY IN THE POST-FRONTAL ENVIRONMENT GENERALLY
ROSE INTO THE LOW 50S. AFTER GIVING CONSIDERATION TO THE HEAT
CONTRIBUTION FROM LAKE MICHIGAN, WHERE LAKE SFC TEMPS REMAIN IN THE
LOW 60S, HIGHS FOR TODAY WERE GIVEN A DOWNWARD ADJUSTMENT INTO THE
55-58 DEGREE RANGE. A FEW 60S STILL CAN`T BE RULED OUT SHOULD CLOUDS
BREAK DURING PEAK HEATING, MOST LIKELY NORTH OF M-59.
THE OTHER FORECAST ISSUE FOR TODAY IS THE PLACEMENT AND DURATION OF
A BAND OF SHOWERS THAT IS CURRENTLY TAKING SHAPE OVER MO/IL. WATER
VAPOR IMAGERY SHOWS AN ENERGETIC ZONAL FLOW ACROSS THE CENTRAL U.S.
WITH EMBEDDED LOW AMPLITUDE SHORTWAVES PROPAGATING ACROSS THE PLAINS
STATES. SHOWER COVERAGE IS EXPANDING AHEAD OF THIS ENERGY AND IN
ASSOCIATION WITH A DEVELOPING FGEN RESPONSE UNDER THE RIGHT ENTRANCE
OF A STRENGTHENING 90KT JET STREAK. THE 00Z GUIDANCE, IN PARTICULAR
THE NAM AND RECENT 3-KM HRRR SIMULATIONS, LOOK SOLID IN THEIR
REPRESENTATION OF THE DEVELOPING FRONTAL CIRCULATION AND ASSOCIATED
PRECIPITATION COVERAGE. FOR NOW, THE ONLY COMPLAINT IS THAT THE
RESPONSE WITHIN THE LOW STATIC STABILITY ENVIRONMENT LEADING THE
ARRIVAL OF THE JET CORE LOOKS HEALTHY, SO LEANED TOWARD AN EARLIER
12-13Z ARRIVAL TIME FOR SOUTHERN AREAS. THE NORTH SIDE OF THE PRECIP
SHIELD WILL INITIALLY CARRY THE SHARP CUTOFF EVIDENT ON THE REGIONAL
RADAR MOSAIC INTO THE AREA, CASTING SOME UNCERTAINTY ON ITS
NORTHWARD EXTENT AS IT STRADDLES THE METRO DETROIT AREA INTO THE
AFTERNOON. HOWEVER, ADDITIONAL NORTHWARD EXPANSION SEEMS PROBABLE
THIS AFTERNOON AS THE POTENT SHORTWAVE ENERGY OVER ID/WY AT 07Z
ACCELERATES TOWARD THE AREA LATER TODAY. LAKE CLOUDS WILL THEN BUILD
INTO THE AREA LATE TONIGHT COINCIDENT WITH THE APPROACH OF THE UPPER
TROUGH AXIS AND H85-SFC DELTA T VALUES PLUMMETING TO 20C OVER LM.
THE STAGE WILL THEN BE SET FOR A COLD START TO SATURDAY MORNING AS
LOW TEMPS DIP INTO THE MID TO UPPER 30S UNDERNEATH INCREASING
BOUNDARY LAYER SKY COVER.
LONG TERM...SATURDAY THROUGH THURSDAY
AS UPPER LOW SHIFTS JUST NORTH OF LAKE SUPERIOR IS PULLED NORTHEAST
INTO BROADER HUDSON BAY VORTEX...UPPER TROUGH AXIS WILL SWING ACROSS
LOWER MICHIGAN AND BRING A SECOND SHOT OF COLD AIR INTO THE AREA ON
SATURDAY. WITH H85 TEMPERATURES FALLING SOLIDLY BELOW 0C...EXPECT
HIGH TEMPERATURES TO REMAIN BETWEEN 50 AND 55. WHILE BEST LIFT AND
FORCING WITH THE VORTICITY CENTER ALONG THIS TROUGH WILL REMAIN TO
THE NORTH OF THE AREA...THERE WILL BE A SMALL CHANCE OF SHOWERS IN
THE 20-30% RANGE AS WRAPAROUND MOISTURE BRUSHES THE AREA AND LAKE
EFFECT ACTIVITY BEGINS TO EXPAND IN THE COLDER AIR.
AFTER ANOTHER DAY WITH HIGH TEMPERATURES AOB 55F ON SUNDAY (WITH
EARLY MORNING TEMPERATURES MOST LIKELY REACHING FREEZING IN SOME
LOCATIONS)...THE NEXT STRONG SHORTWAVE PIVOTING THROUGH THE NORTHERN
GREAT LAKES AROUND THE HUDSON VORTEX WILL BRING A MODERATING TREND
IN THE MONDAY AND TUESDAY TIME FRAME AS SOUTHWEST FLOW BECOMES
ESTABLISHED IN ADVANCE OF THE NEXT STRONG COLD FRONT WHICH WILL
SHIFT INTO THE AREA AS THIS SECOND NORTHERN STREAM STORM SYSTEM
WRAPS NORTHEAST INTO THE AFOREMENTIONED VORTEX. TEMPERATURES WILL
CLIMB WELL INTO THE 50S ON MONDAY AND TO 60 OR BETTER ON TUESDAY AS
THE ARRIVAL OF THIS COLD FRONT IS DELAYED SLIGHTLY AS LOW PRESSURE
RIPPLES UP ALONG IT.
THIS SOUTHERN STREAM LOW PRESSURE WILL BRING THE BEST CHANCE OF
RAINFALL IN THE EXTENDED PORTION OF THE FORECAST AS STRONG FORCING
SHIFTS THROUGH THE AREA WITH THIS PASSAGE OF THIS SYSTEM TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING...WITH ONLY MINOR LAKE EFFECT
ACTIVITY EXPECTED LATER WEDNESDAY INTO THURSDAY SOUTHEAST OF LAKE
HURON.
TEMPERATURES WILL COOL BACK INTO THE MID 50S ON WEDNESDAY...BUT WITH
NORTHERN STREAM SHORTWAVE TAKING A WESTERLY TRACK NORTH OF THE GREAT
LAKES...THE COLDEST AIR WITH THIS SYSTEM WILL REMAIN OVER CANADA AND
EXPECT TEMPERATURES TO REBOUND TO THE UPPER 50S TO AROUND 60 BY
THURSDAY.
MARINE...
A FRESH WEST-SOUTHWEST BREEZE WILL GUST INTO THE 25 TO 30 KNOT RANGE
TODAY AS A COOL AND UNSTABLE AIRMASS OVERSPREADS AREA WATERS. A FEW
GUSTS TO LOW END GALE FORCE WILL BE POSSIBLE FROM OUTER SAGINAW BAY
INTO CENTRAL LAKE HURON THIS AFTERNOON...BUT NO ORGANIZED OR
WIDESPREAD GALES ARE EXPECTED. WINDS WILL GRADUALLY EASE BY LATE
FRIDAY NIGHT BUT WAVES WILL REMAIN REMAIN ELEVATED INTO SATURDAY
MORNING. ALL SMALL CRAFT ADVISORIES THEREFORE REMAIN IN EFFECT FOR
SAGINAW BAY AND THE NEARSHORE FROM PORT AUSTIN TO HARBOR BEACH UNTIL
SATURDAY MORNING. A RENEWED SURGE OF GUSTY WINDS WILL DEVELOP AHEAD
OF ANOTHER PUSH OF COLD AIR ON SATURDAY. A BRIEF REPRIEVE CAN BE
EXPECTED ON SUNDAY AS SURFACE HIGH PRESSURE SLIDES ACROSS THE
AREA...BUT UNSETTLED CONDITIONS WILL QUICKLY REDEVELOP AS THE
SURFACE PRESSURE GRADIENT STRENGTHENS EARLY NEXT WEEK. SOUTH WINDS
WILL INCREASE TO 20 TO 25 KNOTS BY LATE MONDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...SAGINAW BAY AND THE NEARSHORE WATERS FROM
PORT AUSTIN TO HARBOR BEACH...UNTIL 8 AM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...JVC
LONG TERM....DG
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS BILLINGS MT
312 PM MDT FRI OCT 5 2012
.SHORT TERM...VALID FOR SAT AND SUN...
THE MID-LEVEL SHORT WAVE TROUGH APPROACHING FROM THE NORTH AS OF
20 UTC TODAY WILL BE THE LAST IN THE RECENT SERIES OF WAVES THAT
HAVE AFFECTED US IN NORTH-NORTHWEST FLOW ALOFT. HOWEVER...BEFORE
WE BEGIN A SLOW WARMING TREND AS THE MEAN 500-HPA TROUGH THAT IS
BEING FED BY THESE WAVES HEADS EAST ON SAT...WE WILL DEAL WITH A
UPSLOPE-ASSISTED SNOW EVENT IN PARTS OF THE AREA TONIGHT.
TONIGHT...THE 12 UTC GFS AND NAM AND SEVERAL RECENT HRRR AND RAP
SOLUTIONS ALL INCREASED QPF AMOUNTS FROM FAR SOUTH CENTRAL MT TO
SHERIDAN COUNTY WY. THIS IS BASED ON 1/ UPSLOPE FLOW WHICH LASTS
LONGER THAN EARLIER EXPECTED WITH A BIT SLOWER WAVE TIMING...AND
2/ A MODEST BUT DEFINED AREA OF MID-LEVEL FRONTOGENESIS NEAR THE
700 HPA LAYER THAT ASSISTS IN DEEPER VERTICAL MOTION ACROSS PART
OF NORTH CENTRAL WY. SUBSTANTIAL 500-300 Q-VECTOR CONVERGENCE...
AND STEEP MID-LEVEL LAPSE RATES...IS YIELDING CONVECTIVE SHOWERS
OVER MUCH OF THE AREA ALREADY...AND THOSE ELEMENTS WILL HELP OUT
THE POTENTIAL FOR SNOW CENTERED OVER SHERIDAN COUNTY AS WELL. IT
LOOKS LIKE THE DENDRITIC LAYER WILL ALSO BE SATURATED AND HAVE A
DECENT AREA OF OMEGA IN IT OVER NORTH CENTRAL WY...WHICH FURTHER
SOLIDIFIED OUR DECISION TO ISSUE A WINTER WEATHER ADVISORY UNTIL
12 UTC SAT FOR THE SHERIDAN FOOTHILLS. INTERESTINGLY...THERE WAS
A STRONG SIGNAL FOR ACCUMULATING SNOW IN THE CITY OF SHERIDAN IN
THE 12 UTC MET MOS. WHILE WE FEEL SHERIDAN ITSELF WILL LIKELY BE
IN LINE FOR ONLY AN INCH OR TWO OF SNOW...IT IS A BIT RARE FOR A
4 INCH SNOW FORECAST TO SHOW UP IN THE MOS FOR SHERIDAN...SO THE
SITUATION DOES WARRANT CLOSE MONITORING. AT THE VERY LEAST...THE
STORY AREA AND OTHER FOOTHILLS LOCATIONS LOOK IN LINE TO GET 2-4
INCHES OF SNOW...ESPECIALLY IF FORCING ALOFT LINGERS PAST 06 UTC
LIKE THE 12 UTC NAM SUGGESTS. WE ALSO HAVE LIKELY POPS FOR AREAS
LIKE FISHTAIL AND RED LODGE THIS EVENING...BUT IT SEEMS LIKE THE
QPF AND RESULTANT SNOW IN THOSE AREAS WILL BE LESS SINCE FORCING
ALOFT WILL BE LESS ROBUST THERE.
FINALLY...WE STILL EXPECT A WIDESPREAD HARD FREEZE TONIGHT...BUT
WE ARE ALSO STILL GOING A BIT WARMER THAN PURE MOS-BASED NUMBERS
WITH OUR FORECAST LOWS. THAT/S OUT OF RESPECT TO POTENTIAL FOR A
SLOW DECREASE IN CLOUDS...MAINLY IN SOUTH CENTRAL MT. THE CLOUDS
HAVE CAUSED A COLD BIAS ON THE ORDER OF 10+ F TO MOS DURING THE
LAST TWO DAYS...SO WE ARE A BIT HESITANT TO RUN WITH IT...THOUGH
SURFACE DEWPOINTS HAVE FINALLY FALLEN ENOUGH FOR LOWS BELOW 30 F
IN MOST AREAS TONIGHT.
SAT...MODEST MID-LEVEL WARM AIR ADVECTION WILL BEGIN...AND SO WE
WILL BEGIN A WARMING TREND. THE 12 UTC MOS GUIDANCE ALL RESPONDS
TO THIS WARMING ALOFT BY SHOWING HIGHS WELL INTO THE 40S F. WARM
AIR ADVECTION ALOFT AND RELATIVELY WEAK /ALBEIT DOWNSLOPE/ WINDS
IN THE LOW LEVELS ARE NOT VERY FAVORABLE FOR WARMING THOUGH...SO
WE WERE CAUTIOUS IN GOING TOO MUCH WARMER THAN MOS AT THIS TIME.
SUN...MORE AGGRESSIVE WARMING ALOFT IS EXPECTED AS A SURFACE LOW
HEADS EAST ACROSS SOUTHERN CANADA DURING THE DAY. THE 12 UTC GFS
IS A BIT WARMER THAN THE REST OF THE GUIDANCE ALOFT WITH 850-HPA
TEMPERATURES UP TO +13 C AT BILLINGS BY AFTERNOON...BUT WITH THE
DOWNSLOPE FLOW IN THE BOUNDARY LAYER AND A BIT OF BACKING TO THE
FLOW ALOFT...THE WARMER SOLUTION IS PROBABLY A GOOD ONE. WE FEEL
THAT MIXING WILL BE MORE EFFICIENT AS WELL WITH MORE FLOW IN THE
SURFACE TO 2 KM AGL LAYER...SO WE BASED HIGHS MORE OFF OF MIXING
DEPTHS THAN MOS...WHICH MEANT RAISING THEM JUST A BIT. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
EXTENDED MODELS IN FAIRLY GOOD AGREEMENT THROUGH THE MIDDLE OF
NEXT WEEK THEN DIVERGE QUITE A BIT BY LATE WEDNESDAY. OVERALL A
STRAIGHT NORTH TO NORTHWEST FLOW ALOFT WILL BE OVER THE FORECAST
AREA MONDAY AND TUESDAY. A WEAK FRONT IS PROGGED TO MOVE SOUTH
ACROSS THE AREA LATE IN THE DAY MONDAY INTO MONDAY NIGHT WHICH
WILL BRING A SLIGHT CHANCE FOR A RAIN OR SNOW SHOWER.
HOWEVER...NOT MUCH IN THE WAY OF MOISTURE WITH THIS DISTURBANCE SO
ANY SHOWER ACTIVITY IS EXPECTED TO BE LIGHT. BELOW NORMAL
TEMPERATURES CAN BE EXPECTED MONDAY INTO TUESDAY WITH HIGHS MAINLY
IN THE 50S. MODELS BEGIN TO DIVERGE LATE WEDNESDAY AS THE ECMWF
STARTS TO TURN THE NORTHWEST FLOW MORE ZONAL THEN BEGIN TO BUILD A
RIDGE THURSDAY INTO FRIDAY. HOWEVER...THE 12Z GFS NOW BRINGS
ANOTHER COLD FRONT SOUTH LATE WEDNESDAY NIGHT INTO
THURSDAY...WHEREAS...THE PREVIOUS RUN BEGAN TO BUILD A RIDGE. WILL
NOT MAKE ANY SIGNIFICANT CHANGES WITH THIS PACKAGE AND SEE WHAT
THE NEXT MODEL RUN LOOKS LIKE. AS THINGS STAND NOW...DRY
CONDITIONS CAN BE EXPECTED WEDNESDAY THROUGH FRIDAY WITH
TEMPERATURES WARMING BACK TO AROUND SEASONAL LEVELS. HOOLEY
&&
.AVIATION...
SCATTERED SNOW SHOWERS WILL BE POSSIBLE ACROSS THE ENTIRE
FORECAST AREA THROUGH MIDNIGHT RESULTING IN OCCASIONALL MVFR TO
IFR CONDITIONS. IN ADDITION...AREAS OF FOG WILL BE POSSIBLE ACROSS
THE PLAINS MAINLY WEST OF KMLS. OTHERWISE...VFR CONDITIONS WILL
PREVAIL ACROSS THE PLAINS. HOWEVER...MORE NUMEROUS AND HEAVIER
SNOW SHOWER ACTIVITY IS EXPECTED ACROSS THE BIG HORN AND PRYOR
MOUNTAINS...AS WELL AS THE FOOTHILLS AND LOWER ELEVATIONS OF
SHERIDAN COUNTY. MVFR TO IFR CONDITIONS ARE EXPECTED THROUGHOUT
THE NIGHT FOR THE EASTERN FOOTHILLS OF THE BIG HORN MOUNTAINS
EASTWARD ACROSS SHERIDAN COUNTY. ALL MOUNTAIN LOCATIONS WILL BE
OBSCURED THROUGHOUT THE NIGHT. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 024/045 033/063 038/056 037/054 036/061 038/056 039/062
41/U 00/U 01/B 22/W 00/U 00/U 11/U
LVM 019/045 022/059 030/057 026/053 030/062 032/059 033/058
31/U 10/U 01/B 22/W 01/B 11/U 11/U
HDN 026/052 028/063 038/059 037/054 036/063 035/061 036/064
41/U 10/U 01/B 22/W 00/U 00/U 01/U
MLS 022/049 030/062 041/056 036/053 035/061 037/054 037/061
21/U 10/B 12/W 21/B 00/U 00/U 01/U
4BQ 022/046 027/059 039/058 038/053 035/061 038/059 038/061
20/U 00/B 01/B 32/W 00/U 00/U 01/U
BHK 020/046 028/057 040/054 033/050 033/060 034/053 033/059
10/U 00/B 12/W 21/B 00/U 00/U 01/U
SHR 025/040 024/056 034/056 032/050 032/061 033/060 036/057
91/U 10/U 01/B 22/W 10/U 11/U 01/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MDT SATURDAY FOR
ZONE 99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
123 PM MDT FRI OCT 5 2012
.SHORT TERM...VALID FOR TDY AND SAT...
WE HAVE DECIDED TO ISSUE A WINTER WEATHER ADVISORY FROM 00 UTC TO
12 UTC FOR THE SHERIDAN FOOTHILLS FORECAST ZONE FOR 2 TO 4 INCHES
OF SNOW ACCUMULATION. THERE IS ENOUGH EVIDENCE IN THE 12 UTC RUNS
OF THE NAM AND GFS AND VARIOUS OTHER RECENT GUIDANCE TO HOIST THE
HEADLINE. MORE DETAILS ON THIS WILL FOLLOW WITH THE FULL FORECAST
DISCUSSION BY ABOUT 21 UTC. SCHULTZ
PREVIOUS DISCUSSION...ISSUED AT 1055 AM MDT FRI OCT 5 2012...
THE FORECAST WAS UPDATED TO INCREASE POPS A BIT TODAY ACROSS MUCH
OF THE AREA AS A 500-HPA SHORT WAVE TROUGH DROPS SOUTHWARD ACROSS
THE AREA. MID-LEVEL LAPSE RATES WILL STEEPEN THIS AFTERNOON WHILE
MID-LEVEL COLD AIR ADVECTION INCREASES WITH THE WAVE...WHICH WILL
BE SUFFICIENT FOR SCATTERED SHOWERS. THAT COVERAGE HAS SUPPORT ON
THE 12 UTC NAM AND GFS...AS WELL AS THE LAST FEW HRRR RUNS. A MIX
OF RAIN AND SNOW WAS MENTIONED EVEN AS SURFACE TEMPERATURES REACH
THE 40 F OR BETTER MARK IN PLACES SINCE THE WET BULB PROFILE WILL
STILL SUPPORT SNOW. THE TYPE OF SNOW SHOWERS EXPECTED TODAY OFTEN
YIELD TEMPORARY BUT SIGNIFICANT REDUCTIONS IN VISIBILITY. NOTE WE
ALSO EXTENDED AT LEAST SOME 20 TO 30 POPS INTO THIS EVENING BASED
ON THE LATEST TRENDS IN THE 12 UTC NAM AND GFS SOLUTIONS...WHICH
BOTH SHOW A BIT SLOWER TIMING TO THE SHORT WAVE ALOFT. IT APPEARS
THAT FORCING WITH THE WAVE MAY KEEP SOME SHOWERS AROUND BEYOND 00
UTC.
ALONG THE FOOTHILLS LIKE AT FISHTAIL AND RED LODGE SOUTHEAST INTO
THE BIG HORN RANGE AND SHERIDAN COUNTY WY...LOW-LEVEL FLOW HAS AN
UPSLOPE COMPONENT TO IT...AND THAT WILL CONTINUE THROUGH AT LEAST
06 UTC. ADD IN THE 500-300 HPA Q-VECTOR CONVERGENCE WITH THE WAVE
ALOFT AND THE SITUATION EASILY MERITS LIKELY POPS IN THESE PLACES
RIGHT INTO THE EVENING. ADVERTISED SNOW ACCUMULATIONS FALL MOSTLY
INTO THE 1 TO 3 INCH RANGE. HOWEVER...THERE IS A TREND WITHIN THE
12 UTC GUIDANCE FOR A DEEPER UPSLOPE WIND SIGNATURE WHICH LASTS A
COUPLE HOURS LONGER THAN EARLIER ANTICIPATED...SO WE WILL NEED TO
KEEP AN EYE ON THE POTENTIAL FOR A BIT MORE SNOW. OUR CONCERN FOR
GREATER SNOW ACCUMULATIONS WILL BE MAINLY IN SHERIDAN COUNTY WITH
THE 12 UTC NAM ESPECIALLY AGGRESSIVE WITH QPF TOWARD AND PAST THE
00 UTC HOUR ALL THE WAY UP INTO FAR SOUTH CENTRAL MT. MOISTURE IN
THE MODEL IS NON-CONVECTIVE...AND THUS APPEARS TIED TO AN AREA OF
WEAK MID-LEVEL FRONTOGENESIS. THE 12 UTC GFS NOW HAS KEYS ON THIS
AREA OF SLIGHTLY ENHANCED FRONTOGENESIS AS WELL...SO WE CHOSE TO
INCREASE POPS TO THE LIKELY THRESHOLD NOT ONLY OVER THE FOOTHILLS
OF THE BIG HORNS LIKE AT STORY...BUT EVEN AT SHERIDAN AND UP INTO
SOUTHERN BIG HORN COUNTY IN MT FOR THE EVENING HOURS. THIS RAISES
OUR CONCERN A BIT AGAIN FOR THE POSSIBILITY OF REQUIRING A WINTER
WEATHER ADVISORY CENTERED ON THIS EVENING IN AREAS LIKE STORY. WE
WILL CONTINUE TO EVALUATE THAT AS THE DAY WEARS ON. SCHULTZ
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
NORTHERLY FLOW WILL CONTINUE ACROSS THE REGION THROUGH THE MIDDLE
OF NEXT WEEK...WITH RIDGING MAKING A RETURN BY MAYBE NEXT
THURSDAY. THIS PATTERN WILL KEEP TEMPERATURES AT OR BELOW AVERAGE
AS WELL AS BRING OCCASIONAL DISTURBANCES KEEPING CONDITIONS
UNSETTLED.
MAINLY DRY CONDITIONS EXPECTED SUNDAY WITH TEMPERATURES IN THE 50S
TO NEAR 60 DEGREES AHEAD OF A SYSTEM ARRIVING LATE MONDAY.
TEMPERATURES MONDAY SHOULD MAKE IT INTO THE MID 50S BEFORE COOLER
AIR AND PRECIPITATION DROP SOUTHWARD INTO THE AREA LATE IN THE
DAY. PRECIPITATION CHANCES MONDAY NIGHT AND TUESDAY LOOK PRETTY
GOOD WITH STRONG QG FORCING DEVELOPING OVER THE AREA ALONG WITH
LOW LEVEL UPSLOPE FLOW. INCREASED POPS TO CHANCE CATEGORY FOR THIS
TIME FRAME. SYSTEM EXITS THE AREA EARLY WEDNESDAY WITH DRIER AIR
BUILDING IN...BUT STILL ENOUGH MOISTURE FOR A FEW MOUNTAIN SNOW
SHOWERS INTO WEDNESDAY NIGHT.
UPPER LOW OVER CALIFORNIA EARLY IN THE WEEK BEGINS TO TRANSIT TO
THE EAST MID WEEK HELPING TO DRIVE RIDGING NORTHWARD INTO THE AREA
BY THURSDAY. THIS MAY PUSH TEMPERATURES INTO THE MID TO UPPER 60S
THURSDAY AND FRIDAY...HOWEVER SOME MODELS SUGGESTING A GOOD DEAL
OF MOISTURE AND DECENT MID LEVEL FORCING WILL ACCOMPANY THIS
SOUTHERLY FLOW ALOFT RESULTING IN BETTER PRECIPITATION CHANCES
KEEPING TEMPERATURES DOWN. WILL CONTINUE TO WATCH THIS LATE WEEK
SYSTEM FOR POSSIBLE ADJUSTMENTS WITH LATER FORECASTS. CHAMBERS
&&
.AVIATION...
LOW LEVEL UPSLOPE WINDS COMBINED WITH RAIN AND SNOW SHOWERS WILL
RESULT IN MVFR TO LOCAL IFR CONDITIONS IN THE MOUNTAINS AND ALONG
THE FOOTHILLS THROUGHOUT THE DAY. ELSEWHERE...VFR TO LOCAL MVFR
CONDITIONS WILL PREVAIL WITH SCATTERED RAIN OR SNOW SHOWERS. THE
RAIN AND SNOW SHOWERS WILL DISSIPATE AROUND MID EVENING WITH LOCAL
AREAS OF FOG POSSIBLE LATE TONIGHT INTO SATURDAY MORNING. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 041 023/045 031/060 038/056 039/049 036/059 040/056
4/W 31/U 00/U 01/B 32/W 00/U 00/U
LVM 039 011/045 021/056 030/057 028/049 030/060 034/059
4/W 31/U 11/U 11/B 32/W 00/U 00/U
HDN 046 022/052 028/062 038/059 039/053 036/061 037/061
4/W 31/U 10/U 01/B 32/W 00/U 00/U
MLS 044 022/049 030/061 041/056 038/049 035/059 039/054
2/W 21/U 11/B 12/W 32/W 00/U 00/U
4BQ 044 021/049 026/059 039/058 040/049 035/059 040/059
3/W 20/U 00/B 01/B 33/W 00/U 00/U
BHK 043 020/049 028/057 040/054 035/046 033/058 036/052
2/W 00/U 00/B 12/W 32/W 00/U 00/U
SHR 040 020/044 024/056 034/056 034/046 032/059 035/060
6/W 61/U 10/U 00/U 33/W 00/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...WINTER WEATHER ADVISORY IN EFFECT FROM 6 PM THIS EVENING TO 6
AM MDT SATURDAY FOR ZONE 99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1055 AM MDT FRI OCT 5 2012
.SHORT TERM...VALID FOR TDY AND SAT...
THE FORECAST WAS UPDATED TO INCREASE POPS A BIT TODAY ACROSS MUCH
OF THE AREA AS A 500-HPA SHORT WAVE TROUGH DROPS SOUTHWARD ACROSS
THE AREA. MID-LEVEL LAPSE RATES WILL STEEPEN THIS AFTERNOON WHILE
MID-LEVEL COLD AIR ADVECTION INCREASES WITH THE WAVE...WHICH WILL
BE SUFFICIENT FOR SCATTERED SHOWERS. THAT COVERAGE HAS SUPPORT OF
THE 12 UTC NAM AND GFS...AS WELL AS THE LAST FEW HRRR RUNS. A MIX
OF RAIN AND SNOW WAS MENTIONED EVEN AS SURFACE TEMPERATURES REACH
THE 40 F OR BETTER MARK IN PLACES SINCE THE WET BULB PROFILE WILL
STILL SUPPORT SNOW. THE TYPE OF SNOW SHOWERS EXPECTED TODAY OFTEN
YIELD TEMPORARY BUT SIGNIFICANT REDUCTIONS IN VISIBILITY. NOTE WE
ALSO EXTENDED AT LEAST SOME 20 TO 30 POPS INTO THIS EVENING BASED
ON THE LATEST TRENDS IN THE 12 UTC NAM AND GFS SOLUTIONS...WHICH
BOTH SHOW A BIT SLOWER TIMING TO THE SHORT WAVE ALOFT. IT APPEARS
THAT FORCING WITH THE WAVE MAY KEEP SOME SHOWERS AROUND BEYOND 00
UTC.
ALONG THE FOOTHILLS LIKE AT FISHTAIL AND RED LODGE SOUTHEAST INTO
THE BIG HORN RANGE AND SHERIDAN COUNTY WY...LOW-LEVEL FLOW HAS AN
UPSLOPE COMPONENT TO IT...AND THAT WILL CONTINUE THROUGH AT LEAST
06 UTC. ADD IN THE 500-300 HPA Q-VECTOR CONVERGENCE WITH THE WAVE
ALOFT AND THE SITUATION EASILY MERITS LIKELY POPS IN THESE PLACES
RIGHT INTO THE EVENING. ADVERTISED SNOW ACCUMULATIONS FALL MOSTLY
INTO THE 1 TO 3 INCH RANGE. HOWEVER...THERE IS A TREND WITHIN THE
12 UTC GUIDANCE FOR A DEEPER UPSLOPE WIND SIGNATURE WHICH LASTS A
COUPLE HOURS LONGER THAN EARLIER ANTICIPATED...SO WE WILL NEED TO
KEEP AN EYE ON THE POTENTIAL FOR A BIT MORE SNOW. OUR CONCERN FOR
GREATER SNOW ACCUMULATIONS WILL BE MAINLY IN SHERIDAN COUNTY WITH
THE 12 UTC NAM ESPECIALLY AGGRESSIVE WITH QPF TOWARD AND PAST THE
00 UTC HOUR ALL THE WAY UP INTO FAR SOUTH CENTRAL MT. MOISTURE IN
THE MODEL IS NON-CONVECTIVE...AND THUS APPEARS TIED TO AN AREA OF
WEAK MID-LEVEL FRONTOGENESIS. THE 12 UTC GFS NOW HAS EYES ON THIS
AREA OF SLIGHTLY ENHANCED FRONTOGENESIS AS WELL...SO WE CHOSE TO
INCREASE POPS TO THE LIKELY THRESHOLD NOT ONLY OVER THE FOOTHILLS
OF THE BIG HORNS LIKE AT STORY...BUT EVEN AT SHERIDAN AND UP INTO
SOUTHERN BIG HORN COUNTY IN MT FOR THE EVENING HOURS. THIS RAISES
OUR CONCERN A BIT AGAIN FOR THE POSSIBILITY OF REQUIRING A WINTER
WEATHER ADVISORY CENTERED ON THIS EVENING IN AREAS LIKE STORY. WE
WILL CONTINUE TO EVALUATE THAT AS THE DAY WEARS ON. SCHULTZ
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
NORTHERLY FLOW WILL CONTINUE ACROSS THE REGION THROUGH THE MIDDLE
OF NEXT WEEK...WITH RIDGING MAKING A RETURN BY MAYBE NEXT
THURSDAY. THIS PATTERN WILL KEEP TEMPERATURES AT OR BELOW AVERAGE
AS WELL AS BRING OCCASIONAL DISTURBANCES KEEPING CONDITIONS
UNSETTLED.
MAINLY DRY CONDITIONS EXPECTED SUNDAY WITH TEMPERATURES IN THE 50S
TO NEAR 60 DEGREES AHEAD OF A SYSTEM ARRIVING LATE MONDAY.
TEMPERATURES MONDAY SHOULD MAKE IT INTO THE MID 50S BEFORE COOLER
AIR AND PRECIPITATION DROP SOUTHWARD INTO THE AREA LATE IN THE
DAY. PRECIPITATION CHANCES MONDAY NIGHT AND TUESDAY LOOK PRETTY
GOOD WITH STRONG QG FORCING DEVELOPING OVER THE AREA ALONG WITH
LOW LEVEL UPSLOPE FLOW. INCREASED POPS TO CHANCE CATEGORY FOR THIS
TIME FRAME. SYSTEM EXITS THE AREA EARLY WEDNESDAY WITH DRIER AIR
BUILDING IN...BUT STILL ENOUGH MOISTURE FOR A FEW MOUNTAIN SNOW
SHOWERS INTO WEDNESDAY NIGHT.
UPPER LOW OVER CALIFORNIA EARLY IN THE WEEK BEGINS TO TRANSIT TO
THE EAST MID WEEK HELPING TO DRIVE RIDGING NORTHWARD INTO THE AREA
BY THURSDAY. THIS MAY PUSH TEMPERATURES INTO THE MID TO UPPER 60S
THURSDAY AND FRIDAY...HOWEVER SOME MODELS SUGGESTING A GOOD DEAL
OF MOISTURE AND DECENT MID LEVEL FORCING WILL ACCOMPANY THIS
SOUTHERLY FLOW ALOFT RESULTING IN BETTER PRECIPITATION CHANCES
KEEPING TEMPERATURES DOWN. WILL CONTINUE TO WATCH THIS LATE WEEK
SYSTEM FOR POSSIBLE ADJUSTMENTS WITH LATER FORECASTS. CHAMBERS
&&
.AVIATION...
LOW LEVEL UPSLOPE WINDS COMBINED WITH RAIN AND SNOW SHOWERS WILL
RESULT IN MVFR TO LOCAL IFR CONDITIONS IN THE MOUNTAINS AND ALONG
THE FOOTHILLS THROUGHOUT THE DAY. ELSEWHERE...VFR TO LOCAL MVFR
CONDITIONS WILL PREVAIL WITH SCATTERED RAIN OR SNOW SHOWERS. THE
RAIN AND SNOW SHOWERS WILL DISSIPATE AROUND MID EVENING WITH LOCAL
AREAS OF FOG POSSIBLE LATE TONIGHT INTO SATURDAY MORNING. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 041 023/045 031/060 038/056 039/049 036/059 040/056
4/W 31/U 00/U 01/B 32/W 00/U 00/U
LVM 039 011/045 021/056 030/057 028/049 030/060 034/059
4/W 31/U 11/U 11/B 32/W 00/U 00/U
HDN 046 022/052 028/062 038/059 039/053 036/061 037/061
4/W 31/U 10/U 01/B 32/W 00/U 00/U
MLS 044 022/049 030/061 041/056 038/049 035/059 039/054
3/W 21/U 11/B 12/W 32/W 00/U 00/U
4BQ 044 021/049 026/059 039/058 040/049 035/059 040/059
3/W 20/U 00/B 01/B 33/W 00/U 00/U
BHK 043 020/049 028/057 040/054 035/046 033/058 036/052
2/W 00/U 00/B 12/W 32/W 00/U 00/U
SHR 040 020/044 024/056 034/056 034/046 032/059 035/060
6/W 61/U 10/U 00/U 33/W 00/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
317 PM CDT FRI OCT 5 2012
.DISCUSSION...
A FRONTOGENETICALLY FORCED SNOW BAND CONTINUES TO DRIFT SLOWLY
EAST SOUTHEAST ACROSS THE SANDHILLS THIS AFTERNOON. THIS AREA OF
SNOW SHOULD CONTINUE MOVING EAST SOUTHEAST AND WEAKEN AS THE
THERMAL FORCING RELAXES.
ANOTHER ROUND OF SNOW IS FORECAST TO DEVELOP ACROSS SWRN NEB AND
THE PANHANDLE LATE TONIGHT THROUGH EARLY SATURDAY AFTN. THIS IS
BASED ON THE CONSENSUS OF THE 12Z GFS...WRF...NAM...GEM AND 00Z
ECM. HOWEVER THE LATEST RADAR AND RAP/HRRR SOLNS ARE SUGGESTING A
MORE EASTERLY TRACK OF THE DISTURBANCE...CURRENTLY OVER MT...WHICH
COULD PRODUCE SNOW ACROSS NCNTL NEB. THE 18Z NAM IS IN EXCELLENT
AGREEMENT WITH THE GEMREG KEEPING THE BEST FORCING AND SNOW
SOUTHWEST AND ITS NOT UNUSUAL FOR THE RAP AND HRRR TO BE OFF BUT
THE RADAR TRENDS ARE OF CONCERN. A QPF BLEND OF THE MODELS ABOVE
AND A 10 TO 1 RATIO PRODUCE 1 TO 2 INCHES OF SNOW ACROSS THE FAR
WEST AND SOUTHWEST SO NO WINTER WEATHER ADVISORY WILL BE NECESSARY
ASSUMING BRIDGES AND ROAD SURFACES DONT CROSS THE FREEZING MARK
OVERNIGHT.
THE CLOUD COVER BUILDING IN AHEAD OF THIS DISTURBANCE LEAVES A
NARROW WINDOW FOR FREEZING TEMPERATURES ACROSS LINCOLN COUNTY.
OTHER AREAS WEST REMAIN OVERCAST AND AREAS NORTH AND EAST HAVE
ALREADY HAD A FREEZE.
SKIES SHOULD CLEAR OUT BY EARLY SATURDAY EVENING WITH WINDS
BECOMING LIGHT WEST OVERNIGHT. LOW PRESSURE WILL BEGIN DROPPING
SOUTH THROUGH CANADA. A BLEND OF NAM AND MET GUIDANCE WITH NAM12 BIAS
CORRECTION PRODUCED LOWS IN THE TEENS IN SOME AREAS SUNDAY
MORNING. HIGHS REBOUND INTO THE 50S SUNDAY AFTERNOON AS WEST WINDS
CONTINUE. LOWS IN THE 20S FOLLOW MONDAY MORNING WITH HIGHS AROUND
70 MONDAY AFTERNOON. WEST WINDS WILL CONTINUE THROUGH THIS PERIOD
AS LOW PRESSURE MOVES SLOWLY EAST THROUGH MANITOBA AND
SASKATCHEWAN.
TUESDAY THROUGH FRIDAY. UPPER FLOW SHOULD TRANSITION FROM
NORTHWEST FLOW ALOFT AT THE START OF THE PERIOD...TO SOUTHWEST
FLOW ALOFT TOWARD THE END OF THE WEEK AS A LARGE UPPER LEVEL LOW
PRESSURE SYSTEM PUSHES EAST OVER THE DESERT SOUTHWEST. MODELS
AGREE SOMEWHAT THAT THIS UPPER LEVEL LOW PRESSURE SYSTEM WILL
EVENTUALLY MOVE NORTHEAST TOWARD AND ACROSS OUR AREA NEXT WEEKEND.
THIS IS JUST BEYOND THE FORECAST PERIOD...AND ANY PRECIPITATION
ASSOCIATED WITH THIS SYSTEM WOULD BE BEYOND FRIDAY...SO DRY
WEATHER IS CURRENTLY BEING FORECAST THROUGH FRIDAY.
OTHERWISE...HIGH TEMPERATURES WILL STAY MOSTLY IN THE 60S...WITH
PERHAPS ONLY 50S BY FRIDAY BEHIND A COLD FRONT. THIS FRONT SHOULD
BECOME STATIONARY JUST TO OUR SOUTH LATER FRIDAY AND THEN
POTENTIALLY MOVE BACK NORTH THROUGH THE AREA DURING THE WEEKEND AS
A WARM FRONT. WILL CONTINUE TO MONITOR THE POTENTIAL SYSTEM FOR
NEXT WEEKEND.
&&
.AVIATION...
AREAS OF MVFR CEILINGS CONTINUE ACROSS PORTIONS OF SOUTHWEST AND
WESTERN NEBRASKA. THESE ARE EXPECTED TO LIFT...AND BY EARLY
EVENING MOSTLY JUST A MID LEVEL CLOUD DECK IS EXPECTED. ANOTHER
SYSTEM WILL MOVE SOUTHEAST ACROSS THE AREA AFTER 06Z
SATURDAY...WITH CEILINGS LOWERING TO MVFR AND POSSIBLE LIGHT SNOW
WEST OF A LINE FROM KIML TO KOGA TO KAIA. SFC WINDS WILL BE LIGHT
THROUGH THE PERIOD.
&&
.FIRE WEATHER...
FIRE DANGER WILL BECOME VERY HIGH SUNDAY AND MONDAY AFTERNOON.
MODEL CONSENSUS AND BIAS CORRECTED DATA SUGGESTED RH BETWEEN 15
AND 20 PERCENT WITH WINDS GUSTING TO NEAR 25 MPH BOTH DAYS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...FREEZE WARNING FROM 10 PM THIS
EVENING TO 10 AM CDT SATURDAY FOR NEZ059.
&&
$$
SHORT TERM...CDC
AVIATION/EXTENDED...TAYLOR
AREA FORECAST DISCUSSION...CORRECTED
NWS BINGHAMTON NY
304 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A COLD FRONT WORKING OVER OUR REGION THIS AFTERNOON WILL STALL
OVERNIGHT. AS THIS OCCURS...A DISTURBANCE WILL MOVE UP THE
BOUNDARY BRINGING WITH IT AN INCREASED CHANCE FOR SHOWERS TO MUCH
OF CENTRAL NEW YORK AND NORTHEASTERN PENNSYLVANIA. SHOWERS WILL
PREVAIL ACROSS MUCH OF THE REGION SATURDAY MORNING BEFORE
CONDITIONS BEGIN TO IMPROVE BY LATE SATURDAY AFTERNOON. BEYOND
THIS...MUCH COOLER AIR WILL SETTLE INTO THE REGION WITH DAYTIME
HIGHS ONLY EXPECTED TO REACH THE UPPER 40S TO LOWER 50S BY SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN INDIAN SUMMER DAY PREVAILING ACROSS THE FCST AREA THIS AFTERNOON
IN ADVANCE OF A COLD FRONT WHICH CONTINUES TO MAKE SLOW PROGRESS
ACROSS THE REGION. SO FAR TEMPS HAVE WARMED WELL INTO THE LOWER
TO MIDDLE 70S ACROSS MOST LOCATIONS UNDER PARTLY TO MOSTLY CLOUDY
SKIES. AS IS USUALLY THE CASE...VARIOUS FCST MODELS HAVE OVERDONE
THE QPF FCST THIS AFTERNOON AS REGIONAL RADARS SHOW THE CLOSEST
SHWR ACTIVITY STILL QUITE A WAYS TO THE WEST. THAT SAID...VARIOUS
HIGH-RES MODELS TO INCLUDE THE HRRR AND WRF-ARW SUGGEST SHWRS WILL
DEVELOP AFTER 20Z AS THE FRONT CONTINUES TO MOVE THROUGH THE AREA.
WILL MAINTAIN SLGT CHC-CHC MENTION TO ACCOUNT FOR THIS POSSIBILITY.
MAIN FOCUS IN THE NEAR TERM CONTINUES TO BE INCREASING CHANCES FOR
PRECIP OVERNIGHT AS WESTERN ONTARIO CLOSED LOW SHORTWAVE ENERGY
BEGINS TO DIVE SOUTHEAST WITH TIME. AS HAS BEEN THE TREND IN RECENT
DAYS...THE COLD FRONT CURRENTLY WORKING THROUGH THE REGION WILL
EVENTUALLY SLOW DOWN AS AN AREA OF LOW PRESSURE BEGINS WORKING
NORTH ALONG THE BOUNDARY. ADDITIONALLY THE FRONT IS FCST TO BECOME
MORE ANAFRONTISH AS PRECIP BECOMES MORE WIDESPREAD WEST OF THE
BOUNDARY AS UPPER ENERGY ARRIVES FROM THE WEST. FOR NOW WILL
MAINTAIN HIGH END LIKELY TO CATEGORICAL MENTION ACROSS THE
WESTERN ZONES...WITH A GRADUAL SHIFT EAST BY SATURDAY MORNING AS
THE FRONT FINALLY BEGINS MOVING ONCE AGAIN.
FOR SATURDAY...EXPECT WIDESPREAD RAINS IN THE MORNING WITH
ACTIVITY GRADUALLY TAPERING OFF FROM WEST TO EAST BY LATE
MORNING/EARLY AFTERNOON. THE HEAVIEST RAINS WILL FALL ACROSS THE
WESTERN ZONES WHERE TOTAL QPF VALUES MAY APPROACH 1 INCH. FURTHER
SOUTH AND EAST...THE FASTER FRONTAL MOVEMENT WILL RESULT IN MUCH
LOWER PRECIP AMOUNTS WITH QPF TOTALS LARGELY REMAINING UNDER A
QUARTER TO HALF INCH AT BEST. OVERNIGHT TEMPS TONIGHT WILL REMAIN
ON THE WARM SIDE WITH VALUES FALLING ONLY INTO THE UPPER 40S TO
LOWER 50S. COLD AIR ADVECTION EXPECTED TO START TOMORROW WHICH
COMBINED WITH CLOUDS AND PRECIP SHOULD KEEP HIGHS LARGELY IN THE
50S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
UNSETTLED CONDITIONS TO PERSIST RIGHT THROUGH THE START OF THE
SHORT TERM PERIOD AS REGION REMAINS IN BROAD CYCLONIC FLOW ALOFT.
MAIN ATTENTION BY SATURDAY NIGHT WILL BE THE POSSIBILITIES FOR
DEVELOPING LAKE EFFECT ACTIVITY DOWNWIND OF LAKE ONTARIO AS COLD
AIR COMBINED WITH A FAIRLY LONG WESTERLY FETCH CREATES MARGINAL
LAKE EFFECT CONDITIONS. INSPECTION OF SEVERAL FCST SOUNDINGS
SUGGESTS BEST POTENTIAL FOR LAKE EFFECT SHWR ACTIVITY WILL BE
FROM THE SOUTHERN TUG HILL SOUTH THROUGH THE WESTERN MOHAWK VALLEY
AS FLOW WILL TAKE ON A 280-290 DEGREE CONFIGURATION. INVERSION
HEIGHTS BY 12Z SUN WILL BORDER NEAR 10 KFT WITH INCREASING
LAKE GENERATED INSTABILITY EARLY SUN AS COOLER AIR CONTINUES TO
FILTER INTO THE REGION. MAIN QUESTIONS REMAIN JUST HOW FAR SOUTH
THE DEVELOPING BAND IS ABLE TO EXTEND AS THE NAM MAINTAINS ALMOST
A PURE WESTERLY WIND COMPONENT WHILE THE GFS SUGGESTS A BIT MORE
OF A NORTHWESTERLY CONFIGURATION. FOR NOW...HAVE DECIDED TO EXTEND
PRECIP MENTION A BIT FURTHER SOUTH THAN PREVIOUSLY FCST TO INCLUDE
THE GREATER SYR AREA.
BIG QUESTIONS STILL REMAIN WITH THE NEXT SYNOPTIC SYSTEM PROGGED
TO IMPACT OUR AREA BY SUN AFTERNOON. MAIN CULPRIT WILL BE THE NEXT
NORTHERN STREAM PIECE OF ENERGY WHICH IS EXPECTED TO DIVE
SOUTHEAST TOWARDS THE EAST COAST AND INDUCE SFC CYCLOGENESIS OFF
THE COAST OF VIRGINA BEACH. WITH TIME ON SUN THIS FEATURE WILL
MOVE NORTHEAST UP THE COAST WITH INCREASED CHANCES FOR RAIN TO THE
CENTRAL MID-ATLANTIC TO INCLUDE PARTS OF OUR FCST AREA. RIGHT NOW
THE GFS AND ECMWF AND THE FARTHEST EAST WITH THE SFC LOW WHILE THE
NAM REMAINS THE FURTHEST WEST. UNDER THE GFS AND ECMWF/S
SCENARIO...THE BULK OF RAIN WOULD REMAIN SOUTH AND EAST WHILE THE
NAM SOLUTION SUGGESTS INCREASING RAIN CHANCES FOR ALMOST THE
ENTIRE CWA. FOR NOW BASED ON THE AMOUNT OF UNCERTAINTIES THAT
EXIST...WILL MAINTAIN A SLGT CHC TO CHC MENTION THROUGH SUN
AFTERNOON.
BEYOND THIS...SOME POTENTIAL FOR REDEVELOPING LAKE EFFECT ACTIVITY
WILL EXIST EAST OF LAKE ONTARIO SUN NIGHT/EARLY MON. NOT OVERLY
OPTIMISTIC AT THIS POINT AS SFC RIDGING AND AN INFLUX OF DRIER AIR
WILL QUICKLY BUILD IN OVERNIGHT AS HIGH PRESSURE SETTLES OVER THE
REGION. DRY CONDITIONS EXPECTED ON MON AS HIGH PRESSURE REMAINS IN
CONTROL.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
130 PM UPDATE...MED RANGE MODELS INDICATE SFC HIPRES OVR CWA BY 00Z
TUESDAY. ZONAL FLOW AT H5 WL KEEP MAJOR WX SYSTEMS FM MVG IN EARLY
IN THE WEEK. THIS WL CHANGE ON WED AS SFC LOW DVLPS ACRS CNTRL
GREAT LKS IN CONJUNCTION WITH H5 TROF APPCHG THE AREA AND
SPREADING PCPN INTO THE REGION AFTER 12Z WED. AS THIS LOW EXITS TO
THE EAST WED NGT EXPECT LK EFFECT SHOWERS POTENTIALLY MIXED WITH
SNOW TO BE THE DOMINANT WX FEATURE THUR MRNG. THE NEXT SYSTEM WL
SKIRT ACRS ON FRIDAY WITH ANOTHER CHC FOR RA/SN MIX BHND THIS LOW
ON FRI MRNG.
H8 TEMPS WL DROP TO BLO -3C AFTER 06Z THUR AND 12Z FRI. THIS WL
KEEP LOW TEMPS IN THE LOW-MID 30S BOTH MRNGS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
130 PM UPDATE...GNRLY VFR ACRS TERMINALS THIS AFTERNOON WILL GIVE
WAY TO MVFR AND POTENTIAL IFR OVERNIGHT AS A COLD FRONT APPROACHES
THE AREA FROM THE WEST. AREA OF RAIN IS ENTERING WESTERN NEW YORK
AT THIS TIME AND WILL POTENTIALLY AFFECT NY TERMINALS FROM 20Z-24Z
TODAY. NO RESTRICTIONS EXPECTED WITH THIS PRECIPITATION.
WIDESPREAD RAIN WILL MOVE INTO TERMINALS WELL AFTER 08Z WITH
PREDOMINANT MVFR VSBYS/CIGS SETTLING IN FROM NORTH TO SOUTH.
POTENTIAL EXISTS FOR IFR CIGS TOWARD 12Z.
WINDS OUT OF THE SOUTHWEST THIS AFTERNOON AROUND 5KTS WILL
QUICKLY GIVE WAY TO NORTHWEST WINDS BEHIND FRONT AT AROUND 10KTS
BETWEEN 10Z-14Z.
OUTLOOK...
SAT NIGHT TO SUN...SCT MVFR -SHRA ACROSS NORTHERN TERMINALS.
SUN NIGHT TO MON...MAINLY VFR ACROSS NY TERMINALS. SCT MVFR
POSSIBLE SUN NIGHT WIDELY SCATTERED -SHRA ACRS NEPA.
TUE...VFR.
WED...POTENTIAL MVFR IN SCATTERED SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
303 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A COLD FRONT WORKING OVER OUR REGION THIS AFTERNOON WILL STALL
OVERNIGHT. AS THIS OCCURS...A DISTURBANCE WILL MOVE UP THE
BOUNDARY BRINGING WITH IT AN INCREASED CHANCE FOR SHOWERS TO MUCH
OF CENTRAL NEW YORK AND NORTHEASTERN PENNSYLVANIA. SHOWERS WILL
PREVAIL ACROSS MUCH OF THE REGION SATURDAY MORNING BEFORE
CONDITIONS BEGIN TO IMPROVE BY LATE SATURDAY AFTERNOON. BEYOND
THIS...MUCH COOLER AIR WILL SETTLE INTO THE REGION WITH DAYTIME
HIGHS ONLY EXPECTED TO REACH THE UPPER 40S TO LOWER 50S BY SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN INDIAN SUMMER DAY PREVAILING ACROSS THE FCST AREA THIS AFTERNOON
IN ADVANCE OF A COLD FRONT WHICH CONTINUES TO MAKE SLOW PROGRESS
ACROSS THE REGION. SO FAR TEMPS HAVE WARMED WELL INTO THE LOWER
TO MIDDLE 70S ACROSS MOST LOCATIONS UNDER PARTLY TO MOSTLY CLOUDY
SKIES. AS IS USUALLY THE CASE...VARIOUS FCST MODELS HAVE OVERDONE
THE QPF FCST THIS AFTERNOON AS REGIONAL RADARS SHOW THE CLOSEST
SHWR ACTIVITY STILL QUITE A WAYS TO THE WEST. THAT SAID...VARIOUS
HIGH-RES MODELS TO INCLUDE THE HRRR AND WRF-ARW SUGGEST SHWRS WILL
DEVELOP AFTER 20Z AS THE FRONT CONTINUES TO MOVE THROUGH THE AREA.
WILL MAINTAIN SLGT CHC-CHC MENTION TO ACCOUNT FOR THIS POSSIBILITY
HOWEVER OVERALL CONFIDENCE REMAINS MARGINAL.
MAIN FOCUS IN THE NEAR TERM CONTINUES TO BE INCREASING CHANCES FOR
PRECIP OVERNIGHT AS WESTERN ONTARIO CLOSED LOW SHORTWAVE ENERGY
BEGINS TO DIVE SOUTHEAST WITH TIME. AS HAS BEEN THE TREND IN RECENT
DAYS...THE COLD FRONT CURRENTLY WORKING THROUGH THE REGION WILL
EVENTUALLY SLOW DOWN AS AN AREA OF LOW PRESSURE BEGINS WORKING
NORTH ALONG THE BOUNDARY. ADDITIONALLY THE FRONT IS FCST TO BECOME
MORE ANAFRONTISH AS PRECIP BECOMES MORE WIDESPREAD WEST OF THE
BOUNDARY AS UPPER ENERGY ARRIVES FROM THE WEST. FOR NOW WILL
MAINTAIN HIGH END LIKELY TO CATEGORICAL MENTION ACROSS THE
WESTERN ZONES...WITH A GRADUAL SHIFT EAST BY SATURDAY MORNING AS
THE FRONT FINALLY BEGINS MOVING ONCE AGAIN.
FOR SATURDAY...EXPECT WIDESPREAD RAINS IN THE MORNING WITH
ACTIVITY GRADUALLY TAPERING OFF FROM WEST TO EAST BY LATE
MORNING/EARLY AFTERNOON. THE HEAVIEST RAINS WILL FALL ACROSS THE
WESTERN ZONES WHERE TOTAL QPF VALUES MAY APPROACH 1 INCH. FURTHER
SOUTH AND EAST...THE FASTER FRONTAL MOVEMENT WILL RESULT IN MUCH
LOWER PRECIP AMOUNTS WITH QPF TOTALS LARGELY REMAINING UNDER A
QUARTER TO HALF INCH AT BEST. OVERNIGHT TEMPS TONIGHT WILL REMAIN
ON THE WARM SIDE WITH VALUES FALLING ONLY INTO THE UPPER 40S TO
LOWER 50S. COLD AIR ADVECTION EXPECTED TO START TOMORROW WHICH
COMBINED WITH CLOUDS AND PRECIP SHOULD KEEP HIGHS LARGELY IN THE
50S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
UNSETTLED CONDITIONS TO PERSIST RIGHT THROUGH THE START OF THE
SHORT TERM PERIOD AS REGION REMAINS IN BROAD CYCLONIC FLOW ALOFT.
MAIN ATTENTION BY SATURDAY NIGHT WILL BE THE POSSIBILITIES FOR
DEVELOPING LAKE EFFECT ACTIVITY DOWNWIND OF LAKE ONTARIO AS COLD
AIR COMBINED WITH A FAIRLY LONG WESTERLY FETCH CREATES MARGINAL
LAKE EFFECT CONDITIONS. INSPECTION OF SEVERAL FCST SOUNDINGS
SUGGESTS BEST POTENTIAL FOR LAKE EFFECT SHWR ACTIVITY WILL BE
FROM THE SOUTHERN TUG HILL SOUTH THROUGH THE WESTERN MOHAWK VALLEY
AS FLOW WILL TAKE ON A 280-290 DEGREE CONFIGURATION. INVERSION
HEIGHTS BY 12Z SUN WILL BORDER NEAR 10 KFT WITH INCREASING
LAKE GENERATED INSTABILITY EARLY SUN AS COOLER AIR CONTINUES TO
FILTER INTO THE REGION. MAIN QUESTIONS REMAIN JUST HOW FAR SOUTH
THE DEVELOPING BAND IS ABLE TO EXTEND AS THE NAM MAINTAINS ALMOST
A PURE WESTERLY WIND COMPONENT WHILE THE GFS SUGGESTS A BIT MORE
OF A NORTHWESTERLY CONFIGURATION. FOR NOW...HAVE DECIDED TO EXTEND
PRECIP MENTION A BIT FURTHER SOUTH THAN PREVIOUSLY FCST TO INCLUDE
THE GREATER SYR AREA.
BIG QUESTIONS STILL REMAIN WITH THE NEXT SYNOPTIC SYSTEM PROGGED
TO IMPACT OUR AREA BY SUN AFTERNOON. MAIN CULPRIT WILL BE THE NEXT
NORTHERN STREAM PIECE OF ENERGY WHICH IS EXPECTED TO DIVE
SOUTHEAST TOWARDS THE EAST COAST AND INDUCE SFC CYCLOGENESIS OFF
THE COAST OF VIRGINA BEACH. WITH TIME ON SUN THIS FEATURE WILL
MOVE NORTHEAST UP THE COAST WITH INCREASED CHANCES FOR RAIN TO THE
CENTRAL MID-ATLANTIC TO INCLUDE PARTS OF OUR FCST AREA. RIGHT NOW
THE GFS AND ECMWF AND THE FARTHEST EAST WITH THE SFC LOW WHILE THE
NAM REMAINS THE FURTHEST WEST. UNDER THE GFS AND ECMWF/S
SCENARIO...THE BULK OF RAIN WOULD REMAIN SOUTH AND EAST WHILE THE
NAM SOLUTION SUGGESTS INCREASING RAIN CHANCES FOR ALMOST THE
ENTIRE CWA. FOR NOW BASED ON THE AMOUNT OF UNCERTAINTIES THAT
EXIST...WILL MAINTAIN A SLGT CHC TO CHC MENTION THROUGH SUN
AFTERNOON.
BEYOND THIS...SOME POTENTIAL FOR REDEVELOPING LAKE EFFECT ACTIVITY
WILL EXIST EAST OF LAKE ONTARIO SUN NIGHT/EARLY MON. NOT OVERLY
OPTIMISTIC AT THIS POINT AS SFC RIDGING AND AN INFLUX OF DRIER AIR
WILL QUICKLY BUILD IN OVERNIGHT AS HIGH PRESSURE SETTLES OVER THE
REGION. DRY CONDITIONS EXPECTED ON MON AS HIGH PRESSURE REMAINS IN
CONTROL.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
130 PM UPDATE...MED RANGE MODELS INDICATE SFC HIPRES OVR CWA BY 00Z
TUESDAY. ZONAL FLOW AT H5 WL KEEP MAJOR WX SYSTEMS FM MVG IN EARLY
IN THE WEEK. THIS WL CHANGE ON WED AS SFC LOW DVLPS ACRS CNTRL
GREAT LKS IN CONJUNCTION WITH H5 TROF APPCHG THE AREA AND
SPREADING PCPN INTO THE REGION AFTER 12Z WED. AS THIS LOW EXITS TO
THE EAST WED NGT EXPECT LK EFFECT SHOWERS POTENTIALLY MIXED WITH
SNOW TO BE THE DOMINANT WX FEATURE THUR MRNG. THE NEXT SYSTEM WL
SKIRT ACRS ON FRIDAY WITH ANOTHER CHC FOR RA/SN MIX BHND THIS LOW
ON FRI MRNG.
H8 TEMPS WL DROP TO BLO -3C AFTER 06Z THUR AND 12Z FRI. THIS WL
KEEP LOW TEMPS IN THE LOW-MID 30S BOTH MRNGS.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
130 PM UPDATE...GNRLY VFR ACRS TERMINALS THIS AFTERNOON WILL GIVE
WAY TO MVFR AND POTENTIAL IFR OVERNIGHT AS A COLD FRONT APPROACHES
THE AREA FROM THE WEST. AREA OF RAIN IS ENTERING WESTERN NEW YORK
AT THIS TIME AND WILL POTENTIALLY AFFECT NY TERMINALS FROM 20Z-24Z
TODAY. NO RESTRICTIONS EXPECTED WITH THIS PRECIPITATION.
WIDESPREAD RAIN WILL MOVE INTO TERMINALS WELL AFTER 08Z WITH
PREDOMINANT MVFR VSBYS/CIGS SETTLING IN FROM NORTH TO SOUTH.
POTENTIAL EXISTS FOR IFR CIGS TOWARD 12Z.
WINDS OUT OF THE SOUTHWEST THIS AFTERNOON AROUND 5KTS WILL
QUICKLY GIVE WAY TO NORTHWEST WINDS BEHIND FRONT AT AROUND 10KTS
BETWEEN 10Z-14Z.
OUTLOOK...
SAT NIGHT TO SUN...SCT MVFR -SHRA ACROSS NORTHERN TERMINALS.
SUN NIGHT TO MON...MAINLY VFR ACROSS NY TERMINALS. SCT MVFR
POSSIBLE SUN NIGHT WIDELY SCATTERED -SHRA ACRS NEPA.
TUE...VFR.
WED...POTENTIAL MVFR IN SCATTERED SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG
SHORT TERM...CMG
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
143 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING AND BRING IN
COOLER TEMPERATURES. A TROUGH OF LOW PRESSURE WILL ROTATE ACROSS
THE EASTERN GREAT LAKES SATURDAY NIGHT. A RIDGE OF HIGH PRESSURE
WILL EXTEND NORTHEAST OVER THE AREA SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONTAL BOUNDARY IS MAKING SLOW PROGRESS ACROSS THE CWA
THIS AFTERNOON WITH THE HRRR MODEL HANDLING THE PROGRESSION OF THE
SHOWERS RATHER WELL. TEMPERATURES HAVE REACHED NEAR 70 IN THE FAR
SOUTHEAST COUNTIES AHEAD OF THE BOUNDARY WITH COOLER READINGS
BEHIND THE FRONT. REGIONAL MOSAIC RADAR ALREADY SHOWS MORE SHOWERS
OVERSPREADING NORTHERN ILLINOIS AND INDIANA WHICH WILL REACH OHIO
THIS EVENING. ONLY MINOR ADJUSTMENTS MADE TO TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
COLDEST AIR OF THE SEASON MOVES IN TONIGHT AND STICKS AROUND
THROUGH THE WEEKEND. RAIN SHOWERS WILL BE ONGOING DURING THE
EVENING AND WILL SLOWLY END FROM WEST TO EAST OVERNIGHT. THERE MAY
BE A FEW LINGERING SHOWERS ACROSS THE EAST IN THE MORNING...BUT
OVERALL A FAIR BUT COOL WEATHER DAY SATURDAY. WE ARE TALKING HIGHS
ONLY IN THE LOWER/MID 50S AFTER MORNING LOWS FROM 38 TO 45.
THERE ARE A FEW MORE QUESTIONS ABOUT THE WEATHER FOR SATURDAY
NIGHT THROUGH SUNDAY NIGHT YET. OVERALL THERE IS A SECONDARY
TROUGH COMING DOWN ACROSS THE GREAT LAKES SATURDAY INTO SATURDAY
NIGHT WHILE HIGH PRESSURE BUILDS OVER THE PLAINS AND MIDWEST.
ELONGATED TROUGH ALOFT. QUESTIONS WITH HOW MUCH MOISTURE THE GREAT
LAKES TROUGH WILL HAVE...ITS TIMING AND THEN HOW MUCH INFLUENCE
ONE LAST SHORTWAVE MOVING THROUGH THE MEAN TROUGH WILL HAVE. ECMWF
STICKING ITS GROUND AND TAKING A SHARPER SHORTWAVE ACROSS SUNDAY
AND BRINGING PRECIP INTO MUCH OF THE AREA. GFS HOLDING ON WITH
THE GREAT LAKES TROUGH BEING MORE SIGNIFICANT AND THEN POSSIBLY
HAVING TO DEAL WITH SOME LAKE EFFECT/ENHANCED SHOWERS. TIMING AND
DIRECTION OF FLOW WILL DETERMINE WHERE THESE SHOWERS WOULD BE.
THUNDER COULD ACCOMPANY SOME OF THESE SHOWERS SATURDAY NIGHT INTO
SUNDAY OVER THE LAKE WITH LAKE TEMP AND H5 TEMP DIFFERENCE LARGE
ENOUGH. SO FOR NOW HAVE SOME GENERIC POPS FOR SAT NIGHT AND
SUNDAY. WITH THE CLOUD COVER SHOULD KEEP SAT NIGHT LOWS IN THE
UPPER 30S/AROUND 40. COULD A SLUSHY FLAKE OR TWO MIX IN IN THE
HIGHEST ELEVATIONS...POSSIBLY...BUT WITH ALL THE UNCERTAINTY WILL
NOT MENTION YET. HAVE LEANED EVER SO SLIGHTLY TOWARD THE ECMWF AND
THEREFORE HAVE KEPT THE HIGHS SUNDAY LOWER THAN THE GFS MOS
GUIDANCE...MID AND UPPER 40S ONLY.
BY SUNDAY NIGHT INTO MONDAY HIGH PRESSURE BUILDING INTO THE LOCAL
AREA. SUNDAY NIGHT STILL LOOKS TO BE THE COLDEST NIGHT AND HAVE
TEMPS IN THE LOWER/MID 30S. A FROST/FREEZE IS POSSIBLE AWAY FROM
THE LAKE AND WILL CONTINUE TO HIGHLIGHT IN THE HAZARDOUS WEATHER
OUTLOOK.
MONDAY FAIR WITH HIGH PRESSURE BEGINNING TO SHIFT EAST. THIS WILL
ALLOW TEMPS TO RECOVER INTO THE 50S FOR HIGHS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A COLD FRONT MOVES THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY.
CONTINUING WITH THE THREAT OF SHOWERS TUESDAY NIGHT. THE POPS MAY
NEED TO BE ADJUSTED A LITTLE...HIGHER. WITH TIMING ISSUES WILL NOT
MAKE ANY CHANGES NOW...BECAUSE THE IDEA IS RIGHT. SOME LAKE INDUCED
SHOWERS COULD OCCUR WEDNESDAY NIGHT BUT THE HIGH BUILDS IN FAST AND
STRONG...SO WILL KEEP THURSDAY DRY. TEMPERATURES WILL BE BELOW
NORMAL.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
COLD FRONT CONTINUES TO SLOWLY MOVE THROUGH THE FORECAST AREA.
WIDESPREAD RAIN HAS DEVELOPED IN ADVANCE OF THE FRONT. CEILING
HEIGHTS AROUND 1.5 KFT ARE OCCURRING WITH THE HEAVIEST RAIN AND
OTHER CEILINGS AROUND 2.5 KFT SURROUND THIS AREA. VISIBILITIES IN
THE RAIN ARE GENERALLY RANGING FROM 2 TO 4 MILES. EXPECT THIS
TREND TO CONTINUE THIS AFTERNOON AND INTO THE EVENING AS MORE
PRECIPITATION IS FORMING TO THE WEST. MODELS SHOW THE
PRECIPITATION ENDING AFTER MIDNIGHT TONIGHT. SLOWLY DRIER AIR WILL
BUILD OVER THE AREA ON SATURDAY. CLOUDS MAY LINGER OVER THE
EASTERN AREAS AS COLD AIR MOVES OVER THE LAKES ON SATURDAY.
WINDS WILL GENERALLY MAINTAIN A WESTERLY DIRECTION AND MAY VARY
BETWEEN SOUTHWEST TO NORTHWEST DURING THE PERIOD.
.OUTLOOK...NON-VFR SATURDAY AFTERNOON INTO SUNDAY...ESPECIALLY
OVER NORTHEAST OHIO AND NORTHWEST PA.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS LAKE ERIE THIS MORNING. THE WINDS WILL
BECOME WEST AFTER FRONTAL PASSAGE AND THEN MAY DECREASE SOME THIS
EVENING BEFORE PICKING UP AGAIN BY DAYBREAK SATURDAY. IT WILL BE
MAINLY A WEST WIND SO WILL ISSUE A SMALL CRAFT ADVISORY FROM LAKE
COUNTY EAST UNTIL EARLY SUNDAY MORNING. THE WESTERLY FLOW SHOULD
CAUSE WAVES TO INCREASE TO 3 TO 5 FEET THIS MORNING...THEY WILL
PROBABLY FLUCTUATE AND WILL DEFINITELY BE AT SMALL CRAFT ADVISORY
CRITERIA SATURDAY BEFORE DECREASING SATURDAY NIGHT. THE SMALL CRAFT
MAY HAVE TO BE EXTENDED A LITTLE WEST ON SATURDAY AS THE WINDS WILL
BE STRONGEST AND MOST CONSISTENT THEN.
WATERSPOUTS WILL BE POSSIBLE ON THE LAKE MAINLY SATURDAY AFTERNOON
INTO SATURDAY NIGHT. WILL MENTION IN HAZARDOUS WEATHER OUTLOOK.
A RIDGE WILL BE BUILDING INTO THE OHIO VALLEY SUNDAY AND AS THE
RIDGE BECOMES ESTABLISHED BY MONDAY MORNING THE WINDS WILL BECOME
SOUTHWEST ON THE LAKE. THE SOUTHWEST FLOW WILL INCREASE MONDAY AND
TUESDAY AND THE SPEEDS COULD GET CLOSE TO 20 TO 25 KNOTS NEEDING A
SMALL CRAFT ADVISORY...THIS WILL HAVE TO BE MONITORED. A COLD FRONT
MOVES ACROSS THE LAKE LATE TUESDAY NIGHT AND WEDNESDAY...ANOTHER
SMALL CRAFT WILL LIKELY BE NEEDED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT SUNDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...REL
SHORT TERM...OUDEMAN
LONG TERM...KIELTYKA
AVIATION...GARNET
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1234 PM EDT FRI OCT 5 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING AND BRING IN
COOLER TEMPERATURES. A TROUGH OF LOW PRESSURE WILL ROTATE ACROSS
THE EASTERN GREAT LAKES SATURDAY NIGHT. A RIDGE OF HIGH PRESSURE
WILL EXTEND NORTHEAST OVER THE AREA SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONTAL BOUNDARY IS MAKING SLOW PROGRESS ACROSS THE CWA
THIS AFTERNOON WITH THE HRRR MODEL HANDLING THE PROGRESSION OF THE
SHOWERS RATHER WELL. TEMPERATURES HAVE REACHED NEAR 70 IN THE FAR
SOUTHEAST COUNTIES AHEAD OF THE BOUNDARY WITH COOLER READINGS
BEHIND THE FRONT. REGIONAL MOSAIC RADAR ALREADY SHOWS MORE SHOWERS
OVERSPREADING NORTHERN ILLINOIS AND INDIANA WHICH WILL REACH OHIO
THIS EVENING. ONLY MINOR ADJUSTMENTS MADE TO TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
COLDEST AIR OF THE SEASON MOVES IN TONIGHT AND STICKS AROUND
THROUGH THE WEEKEND. RAIN SHOWERS WILL BE ONGOING DURING THE
EVENING AND WILL SLOWLY END FROM WEST TO EAST OVERNIGHT. THERE MAY
BE A FEW LINGERING SHOWERS ACROSS THE EAST IN THE MORNING...BUT
OVERALL A FAIR BUT COOL WEATHER DAY SATURDAY. WE ARE TALKING HIGHS
ONLY IN THE LOWER/MID 50S AFTER MORNING LOWS FROM 38 TO 45.
THERE ARE A FEW MORE QUESTIONS ABOUT THE WEATHER FOR SATURDAY
NIGHT THROUGH SUNDAY NIGHT YET. OVERALL THERE IS A SECONDARY
TROUGH COMING DOWN ACROSS THE GREAT LAKES SATURDAY INTO SATURDAY
NIGHT WHILE HIGH PRESSURE BUILDS OVER THE PLAINS AND MIDWEST.
ELONGATED TROUGH ALOFT. QUESTIONS WITH HOW MUCH MOISTURE THE GREAT
LAKES TROUGH WILL HAVE...ITS TIMING AND THEN HOW MUCH INFLUENCE
ONE LAST SHORTWAVE MOVING THROUGH THE MEAN TROUGH WILL HAVE. ECMWF
STICKING ITS GROUND AND TAKING A SHARPER SHORTWAVE ACROSS SUNDAY
AND BRINGING PRECIP INTO MUCH OF THE AREA. GFS HOLDING ON WITH
THE GREAT LAKES TROUGH BEING MORE SIGNIFICANT AND THEN POSSIBLY
HAVING TO DEAL WITH SOME LAKE EFFECT/ENHANCED SHOWERS. TIMING AND
DIRECTION OF FLOW WILL DETERMINE WHERE THESE SHOWERS WOULD BE.
THUNDER COULD ACCOMPANY SOME OF THESE SHOWERS SATURDAY NIGHT INTO
SUNDAY OVER THE LAKE WITH LAKE TEMP AND H5 TEMP DIFFERENCE LARGE
ENOUGH. SO FOR NOW HAVE SOME GENERIC POPS FOR SAT NIGHT AND
SUNDAY. WITH THE CLOUD COVER SHOULD KEEP SAT NIGHT LOWS IN THE
UPPER 30S/AROUND 40. COULD A SLUSHY FLAKE OR TWO MIX IN IN THE
HIGHEST ELEVATIONS...POSSIBLY...BUT WITH ALL THE UNCERTAINTY WILL
NOT MENTION YET. HAVE LEANED EVER SO SLIGHTLY TOWARD THE ECMWF AND
THEREFORE HAVE KEPT THE HIGHS SUNDAY LOWER THAN THE GFS MOS
GUIDANCE...MID AND UPPER 40S ONLY.
BY SUNDAY NIGHT INTO MONDAY HIGH PRESSURE BUILDING INTO THE LOCAL
AREA. SUNDAY NIGHT STILL LOOKS TO BE THE COLDEST NIGHT AND HAVE
TEMPS IN THE LOWER/MID 30S. A FROST/FREEZE IS POSSIBLE AWAY FROM
THE LAKE AND WILL CONTINUE TO HIGHLIGHT IN THE HAZARDOUS WEATHER
OUTLOOK.
MONDAY FAIR WITH HIGH PRESSURE BEGINNING TO SHIFT EAST. THIS WILL
ALLOW TEMPS TO RECOVER INTO THE 50S FOR HIGHS.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
A COLD FRONT MOVES THROUGH LATE TUESDAY NIGHT INTO WEDNESDAY.
CONTINUING WITH THE THREAT OF SHOWERS TUESDAY NIGHT. THE POPS MAY
NEED TO BE ADJUSTED A LITTLE...HIGHER. WITH TIMING ISSUES WILL NOT
MAKE ANY CHANGES NOW...BECAUSE THE IDEA IS RIGHT. SOME LAKE INDUCED
SHOWERS COULD OCCUR WEDNESDAY NIGHT BUT THE HIGH BUILDS IN FAST AND
STRONG...SO WILL KEEP THURSDAY DRY. TEMPERATURES WILL BE BELOW
NORMAL.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
COLD FRONT WILL MOVE THROUGH MFD AND CLE AROUND 12Z AND ERI AND
YNG 15Z-16Z. A BRIEF PERIOD OF CEILINGS AROUND 1500 FEET WILL
OCCUR AFTER THE FRONTAL PASSAGE. THE RAIN IS ON THE OH AND INDIANA LINE
AND MOVING EAST. THE MODELS ALL HAVE THE SAME IDEA BUT DIFFERENCES
IN THE MOISTURE AND TIMING. CONDITIONS SHOULD DROP TO MVFR...THE
SREF SEEMS TO HAVE A GOOD HANDLE ON THINGS. CONFIDENCE IN THE
TIMING OF THE LOWERING CONDITIONS IS MODERATE AT THIS TIME. ANY
IFR CONDITIONS SHOULD BE BRIEF AND COULD BE EITHER VISIBILITY OR
CEILINGS. CONDITIONS WILL BEGIN IMPROVING TO VFR FROM THE
NORTHWEST LATE THIS EVENING. BY DAYBREAK SATURDAY THE LAKE AND 850
MB TEMPERATURE DIFFERENCE WILL BE NEAR 19C. WITH THE FLOW WESTERLY
THE SHOWERS SHOULD BE MAINLY EAST OF CLE.
.OUTLOOK...NON-VFR SATURDAY AFTERNOON INTO SUNDAY...ESPECIALLY
OVER NORTHEAST OHIO AND NORTHWEST PA.
&&
.MARINE...
A COLD FRONT WILL MOVE ACROSS LAKE ERIE THIS MORNING. THE WINDS WILL
BECOME WEST AFTER FRONTAL PASSAGE AND THEN MAY DECREASE SOME THIS
EVENING BEFORE PICKING UP AGAIN BY DAYBREAK SATURDAY. IT WILL BE
MAINLY A WEST WIND SO WILL ISSUE A SMALL CRAFT ADVISORY FROM LAKE
COUNTY EAST UNTIL EARLY SUNDAY MORNING. THE WESTERLY FLOW SHOULD
CAUSE WAVES TO INCREASE TO 3 TO 5 FEET THIS MORNING...THEY WILL
PROBABLY FLUCTUATE AND WILL DEFINITELY BE AT SMALL CRAFT ADVISORY
CRITERIA SATURDAY BEFORE DECREASING SATURDAY NIGHT. THE SMALL CRAFT
MAY HAVE TO BE EXTENDED A LITTLE WEST ON SATURDAY AS THE WINDS WILL
BE STRONGEST AND MOST CONSISTENT THEN.
WATERSPOUTS WILL BE POSSIBLE ON THE LAKE MAINLY SATURDAY AFTERNOON
INTO SATURDAY NIGHT. WILL MENTION IN HAZARDOUS WEATHER OUTLOOK.
A RIDGE WILL BE BUILDING INTO THE OHIO VALLEY SUNDAY AND AS THE
RIDGE BECOMES ESTABLISHED BY MONDAY MORNING THE WINDS WILL BECOME
SOUTHWEST ON THE LAKE. THE SOUTHWEST FLOW WILL INCREASE MONDAY AND
TUESDAY AND THE SPEEDS COULD GET CLOSE TO 20 TO 25 KNOTS NEEDING A
SMALL CRAFT ADVISORY...THIS WILL HAVE TO BE MONITORED. A COLD FRONT
MOVES ACROSS THE LAKE LATE TUESDAY NIGHT AND WEDNESDAY...ANOTHER
SMALL CRAFT WILL LIKELY BE NEEDED.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 AM EDT SUNDAY FOR LEZ147>149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...REL
SHORT TERM...OUDEMAN
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA