Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/11/12
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1138 AM PDT TUE OCT 9 2012
.DISCUSSION...AS OF 9:00 AM PDT TUESDAY MORNING...SURFACE LOW
PRESSURE SYSTEM CONTINUES TO MOVE VERY SLOWLY SOUTH
SOUTHEAST...CURRENTLY NEAR 35N/125W. OCCASIONAL LIGHTNING STRIKES
WERE ASSOCIATED WITH THE LOW CENTER...BUT CONTINUE WELL OFF THE
CALIFORNIA COAST. PARTLY TO MOSTLY CLOUDS SKIES STREAMED NORTHEAST
OVER SONOMA AND NAPA COUNTIES...WHILE THE REST OF THE REGION
REMAINED MOSTLY CLEAR. TEMPERATURES OVERNIGHT FELL INTO THE MID 40S TO
MID 50S...SIMILAR TO THOSE OBSERVED LAST NIGHT AND NEAR NORMAL FOR
THE MIDDLE OF OCTOBER. IN ADDITION...THE NORTH BAY VALLEY DID SEE
PATCHY DENSE FOG...WITH VISIBILITIES DOWN TO A QUARTER MILE
OVERNIGHT.
ANOTHER DIFFICULT FORECAST IN STORE TODAY THROUGH THE END OF THE
WORK WEEK...AS THE LOW CONTINUES TO MIGRATE SLOWLY SOUTH. UPDATED
THE FORECAST THIS MORNING TO REMOVE SLIGHT CHANCE OF THUNDERSTORMS
ONSHORE...BUT KEPT THEM OVER THE WATERS. ALSO INCREASED COVERAGE
OF SLIGHT CHANCE OF RAIN SHOWERS...AS THE HRRR INDICATED SPOTTY
LIGHT RAIN SHOWERS THIS AFTERNOON WELL INLAND.
HOWEVER...CONFIDENCE REMAINS EXTREMELY LOW WITH LOCATION AND
TIMING OF ANY PRECIPITATION.
OTHERWISE...WE WILL CONTINUE TO MONITOR THE FORECAST CLOSELY AND
UPDATE WITH ANY NEW INFORMATION.
.PREVIOUS DISCUSSION...AS OF 3:45 AM PDT TUESDAY MORNING...A
MIXED BAG OF WEATHER ACROSS THE DISTRICT AND COASTAL WATERS. FOG
PRODUCT IMAGERY AND SFC OBS SHOW PATCHY LOW CLOUDS ALONG THE COAST
AND IN THE NORTH BAY VALLEYS...EVEN THOUGH THE SAN CARLOS SODAR
AND THE FT ORD PROFILER ARE NOT INDC A MARINE LAYER.
WATER VAPOR IMAGERY IS SHOWING THE UPPER LOW CENTERED ABOUT 260
MILES WEST OF THE GOLDEN GATE. A STRONG VORT MAX WEST OF PT REYES
IS ROTATING AROUND THE UPPER LOW. THE VORT MAX HAS THE CLASSIC
COMMA HEAD LOOK ON WATER VAPOR IMAGERY. THIS VORT MAX HAS
GENERATED SHOWERS AND THUNDERSTORMS ...WITH LIGHTNING STRIKES LESS
THAN 50 MILES WEST OF THE NORTH BAY COASTLINE. KMUX RADAR IS INDC
THAT THE SHOWER ACTIVITY IS ABOUT 25 MILES WEST OF PT REYES AS OF
3:30 AM. OTHER VORT MAXES CONTINUE TO ROTATE AROUND THE UPPER LOW AS
IT MOVES SLOWLY SOUTHEAST.
TODAY THROUGH THURSDAY...MODELS ARE IN AGREEMENT IN TAKING THE
UPPER LOW SLOWLY SOUTHEAST TO WEST OF BIG SUR BY EARLY WEDNESDAY
MORNING. HOWEVER...THE MODELS ARE HAVING A DIFFICULT TIME WITH THE
DETAILS. HAVE ADDED A SLIGHT CHC OF SHOWERS/THUNDERSTORMS TO THE
OUTER COASTAL WATERS...INNER COASTAL WATERS NORTH OF THE GOLDEN
GATE...AND IN THE NORTH BAY AS THE VORT MAX ROTATES TOWARDS THE
COAST NORTH OF THE GOLDEN GATE. CONVECTIVE ACTIVITY WILL END IN
THE NORTH BAY BY LATE AFTN...WITH THE SLIGHT CHANCE OF SHOWERS
SHIFTING SOUTH TONIGHT AND WEDNESDAY WITH THE UPPER LOW. DID NOT
MENTION THUNDER FOR TONIGHT...BUT THIS WILL NEED TO BE WATCHED IN
LIGHT OF THE CONVECTIVE ACTIVITY THIS EARLY MORNING. HAVE KEPT THE
MENTION OF THUNDERSTORMS WEDNESDAY AFTN AND EVENING FOR MOST OF
MONTEREY AND SAN BENITO COUNTIES AS IT LOOKS LIKE IT WILL BE QUITE
UNSTABLE WITH LI`S AS LOW AS -3C AND CAPES GREATER THAN 350 J/KG.
SHOWERS COULD LINGER IN THE SOUTH ON THURSDAY WITH WRAP AROUND
MOISTURE FROM THE UPPER LOW AS IT MOVES INTO SOUTHERN CALIFORNIA.
FRIDAY INTO EARLY NEXT WEEK...A WEAK FRONT WILL MOVE INTO NORTHERN
CALIFORNIA FRIDAY AFTN INTO SATURDAY. MEDIUM RANGE MODELS CONTINUE
TO SHOW THIS FRONT SPLITTING AS IT MOVES TO THE COAST. AS OF
NOW...IT LOOKS LIKE ANY RAIN WILL REMAIN NORTH OF THE GOLDEN GATE.
AN ACTIVE STORM TRACK WILL SET UP ACROSS THE PACIFIC NORTHWEST AND
NORTHERN CALIFORNIA SUNDAY INTO NEXT WEEK WITH THE DISTRICT ON THE
SOUTHERN FRINGE. SUNDAY SHOULD BE DRY ACROSS THE DISTRICT. THE JET
COULD DIP A LITTLE FURTHER SOUTH FOR A SLIGHT CHANCE OF WARM
ADVECTION RAIN IN NORTHERN SONOMA COUNTY ON MONDAY.
&&
.AVIATION...AS OF 11:35 AM TUESDAY...LOW CONTINUES TO SPIN OFF THE
COAST. RADAR AND SATELLITE ARE NOT IMPRESSIVE FOR RAIN CHANCES
MOVING INTO OUR AREA SO NEW TAF PACKAGE KEEPS VCSH OUT OF ANY
TERMINALS. TONIGHT IS A VERY TOUGH CALL AS THE ONSHORE FLOW PICKS
UP ALONG WITH HIGHER BL RH VALUES. HOWEVER...THESE TYPE OF SETUPS
BEHIND A LOW HEADING TO THE SOUTH ARE VERY DIFFICULT. FOR NOW DECIDED
TO BRING IN MOSTLY IFR CONDITIONS OVERNIGHT BUT NOT AS PESSIMISTIC
AS SOME OF THE GUIDANCE. WINDS SHOULD NOT BE A FACTOR AND WILL BE
THE TYPICAL AFTERNOON/EVENING SEA BREEZES. HIGH CONFIDENCE THROUGH TODAY.
LOW CONFIDENCE AFTER 05Z.
.VICINITY OF KSFO...VFR THROUGH AT LEAST 03Z. FROM 04Z ON GUIDANCE
BRINGS LOW CLOUDS BACK TO MVFR LEVELS. DECIDED TO GO WITH CIGS
AROUND 015 FROM 05Z ON. AFTERNOON AND EARLY EVENING WINDS OF 11 TO
16 KT EXPECTED. HIGH CONFIDENCE THROUGH 03Z. LOW CONFIDENCE
BEYOND THAT.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR THROUGH THE DAY WITH IFR/MVFR
CIGS FORECAST TO RETURN AFTER 07Z. AGAIN...DIFFICULT TO FORECAST
WITH THIS TYPE OF SETUP. SO...HIGH CONFIDENCE THROUGH 06Z WITH LOW
CONFIDENCE AFTER THAT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: STROBIN
AVIATION/MARINE: CANEPA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
904 AM PDT TUE OCT 9 2012
.DISCUSSION...AS OF 9:00 AM PDT TUESDAY MORNING...SURFACE LOW
PRESSURE SYSTEM CONTINUES TO MOVE VERY SLOWLY SOUTH
SOUTHEAST...CURRENTLY NEAR 35N/125W. OCCASIONAL LIGHTNING STRIKES
WERE ASSOCIATED WITH THE LOW CENTER...BUT CONTINUE WELL OFF THE
CALIFORNIA COAST. PARTLY TO MOSTLY CLOUDS SKIES STREAMED NORTHEAST
OVER SONOMA AND NAPA COUNTIES...WHILE THE REST OF THE REGION
REMAINED MOSTLY CLEAR. TEMPERATURES OVERNIGHT FELL INTO THE MID 40S TO
MID 50S...SIMILAR TO THOSE OBSERVED LAST NIGHT AND NEAR NORMAL FOR
THE MIDDLE OF OCTOBER. IN ADDITION...THE NORTH BAY VALLEY DID SEE
PATCHY DENSE FOG...WITH VISIBILITIES DOWN TO A QUARTER MILE
OVERNIGHT.
ANOTHER DIFFICULT FORECAST IN STORE TODAY THROUGH THE END OF THE
WORK WEEK...AS THE LOW CONTINUES TO MIGRATE SLOWLY SOUTH. UPDATED
THE FORECAST THIS MORNING TO REMOVE SLIGHT CHANCE OF THUNDERSTORMS
ONSHORE...BUT KEPT THEM OVER THE WATERS. ALSO INCREASED COVERAGE
OF SLIGHT CHANCE OF RAIN SHOWERS...AS THE HRRR INDICATED SPOTTY
LIGHT RAIN SHOWERS THIS AFTERNOON WELL INLAND.
HOWEVER...CONFIDENCE REMAINS EXTREMELY LOW WITH LOCATION AND
TIMING OF ANY PRECIPITATION.
OTHERWISE...WE WILL CONTINUE TO MONITOR THE FORECAST CLOSELY AND
UPDATE WITH ANY NEW INFORMATION.
.PREVIOUS DISCUSSION...AS OF 3:45 AM PDT TUESDAY MORNING...A
MIXED BAG OF WEATHER ACROSS THE DISTRICT AND COASTAL WATERS. FOG
PRODUCT IMAGERY AND SFC OBS SHOW PATCHY LOW CLOUDS ALONG THE COAST
AND IN THE NORTH BAY VALLEYS...EVEN THOUGH THE SAN CARLOS SODAR
AND THE FT ORD PROFILER ARE NOT INDC A MARINE LAYER.
WATER VAPOR IMAGERY IS SHOWING THE UPPER LOW CENTERED ABOUT 260
MILES WEST OF THE GOLDEN GATE. A STRONG VORT MAX WEST OF PT REYES
IS ROTATING AROUND THE UPPER LOW. THE VORT MAX HAS THE CLASSIC
COMMA HEAD LOOK ON WATER VAPOR IMAGERY. THIS VORT MAX HAS
GENERATED SHOWERS AND THUNDERSTORMS ...WITH LIGHTNING STRIKES LESS
THAN 50 MILES WEST OF THE NORTH BAY COASTLINE. KMUX RADAR IS INDC
THAT THE SHOWER ACTIVITY IS ABOUT 25 MILES WEST OF PT REYES AS OF
3:30 AM. OTHER VORT MAXES CONTINUE TO ROTATE AROUND THE UPPER LOW AS
IT MOVES SLOWLY SOUTHEAST.
TODAY THROUGH THURSDAY...MODELS ARE IN AGREEMENT IN TAKING THE
UPPER LOW SLOWLY SOUTHEAST TO WEST OF BIG SUR BY EARLY WEDNESDAY
MORNING. HOWEVER...THE MODELS ARE HAVING A DIFFICULT TIME WITH THE
DETAILS. HAVE ADDED A SLIGHT CHC OF SHOWERS/THUNDERSTORMS TO THE
OUTER COASTAL WATERS...INNER COASTAL WATERS NORTH OF THE GOLDEN
GATE...AND IN THE NORTH BAY AS THE VORT MAX ROTATES TOWARDS THE
COAST NORTH OF THE GOLDEN GATE. CONVECTIVE ACTIVITY WILL END IN
THE NORTH BAY BY LATE AFTN...WITH THE SLIGHT CHANCE OF SHOWERS
SHIFTING SOUTH TONIGHT AND WEDNESDAY WITH THE UPPER LOW. DID NOT
MENTION THUNDER FOR TONIGHT...BUT THIS WILL NEED TO BE WATCHED IN
LIGHT OF THE CONVECTIVE ACTIVITY THIS EARLY MORNING. HAVE KEPT THE
MENTION OF THUNDERSTORMS WEDNESDAY AFTN AND EVENING FOR MOST OF
MONTEREY AND SAN BENITO COUNTIES AS IT LOOKS LIKE IT WILL BE QUITE
UNSTABLE WITH LI`S AS LOW AS -3C AND CAPES GREATER THAN 350 J/KG.
SHOWERS COULD LINGER IN THE SOUTH ON THURSDAY WITH WRAP AROUND
MOISTURE FROM THE UPPER LOW AS IT MOVES INTO SOUTHERN CALIFORNIA.
FRIDAY INTO EARLY NEXT WEEK...A WEAK FRONT WILL MOVE INTO NORTHERN
CALIFORNIA FRIDAY AFTN INTO SATURDAY. MEDIUM RANGE MODELS CONTINUE
TO SHOW THIS FRONT SPLITTING AS IT MOVES TO THE COAST. AS OF
NOW...IT LOOKS LIKE ANY RAIN WILL REMAIN NORTH OF THE GOLDEN GATE.
AN ACTIVE STORM TRACK WILL SET UP ACROSS THE PACIFIC NORTHWEST AND
NORTHERN CALIFORNIA SUNDAY INTO NEXT WEEK WITH THE DISTRICT ON THE
SOUTHERN FRINGE. SUNDAY SHOULD BE DRY ACROSS THE DISTRICT. THE JET
COULD DIP A LITTLE FURTHER SOUTH FOR A SLIGHT CHANCE OF WARM
ADVECTION RAIN IN NORTHERN SONOMA COUNTY ON MONDAY.
&&
.AVIATION...AS OF 7:30 AM TUESDAY...VARIOUS CLOUD LAYERS ARE
DEVELOPING OVER THE BAY AREA AND CENTRAL COAST AS THE LARGE UPPER
LOW PRESSURE AREA TO THE WEST GETS A BIT CLOSER TO THE AREA THIS
MORNING. THE MODELS HAVE BEEN PREDICTING AN INCREASE IN LOW LEVEL
CLOUDINESS OVERNIGHT. SOME TERMINALS ARE STILL REPORTING VFR
HOWEVER. LOWER CONFIDENCE IN THE FORECAST THIS MORNING.
VICINITY OF KSFO...VFR THROUGH THE DAY TODAY AS CLOUDS QUICKLY
LIFTED THIS MORNING AND VARIOUS CAMS SHOW NEARLY CLEAR SKIES
ACROSS THE BOARD. ONLY CAUTION WOULD BE IF ANY CIGS COME IN OFF
THE COAST THIS MORNING HOWEVER RADAR/SATELLITE SHOWS THE CLOSEST
BAND STALLING AND DISSIPATING SO FEEL THEY WILL NOT HAVE ANY
IMPACT THROUGH 20Z. UPPER LOW TO THE WEST WILL DRIFT CLOSER THE
AREA TODAY AND TONIGHT CAUSING A FEW SHOWERS IN INCREASINGLY
UNSTABLE AIRMASS.
KSFO BRIDGE APPROACH...CLOUDS CONFINED TO THE EAST BAY MOSTLY
FROM KOAK TO THE NORTH AND SHOULD NOT IMPACT THE APPROACH.
THEREFORE...OVERALL SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...A PATCH OF LOW CLOUDS IS OBSERVED
OVER THE MONTEREY BAY NEAR KWVI. KSNS AND KMRY ARE STILL REPORTING
VFR AT THIS HOUR AND BELIEVE THIS WILL HOLD THOUGH CONFIDENCE IS
LOW. VFR IS LIKELY FROM LATE MORNING THROUGH THE AFTERNOON WITH A
SIMILAR CHANCE FOR SHOWER ACTIVITY DUE TO INBOUND LOW PRESSURE
AREA.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: STROBIN
AVIATION/MARINE: CANEPA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
150 AM EDT TUE OCT 9 2012
.SYNOPSIS...
LOW PRESSURE FORMING ALONG THE MID ATLANTIC COAST OVERNIGHT
WILL SLOWLY TRACK NORTHEAST...PASSING EAST OF THE TRI-STATE AREA
TUESDAY EVENING. HIGH PRESSURE THEN BRIEFLY BUILDS BACK IN BEHIND
THE LOW TUESDAY NIGHT. A COLD FRONT MOVES THROUGH WEDNESDAY
AFTERNOON AND EVENING...WITH HIGH PRESSURE BUILDING IN ON
THURSDAY. ANOTHER COLD FRONT MOVES THROUGH ON FRIDAY...FOLLOWED BY
HIGH PRESSURE ON SATURDAY. A WARM FRONT WILL THEN PASS BY ON
SUNDAY...FOLLOWED BY A COLD FRONT ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WITH THE DRY AIR REMAINING IN THE AREA HAVE LOWERED POPS UNTIL
LATE TONIGHT WHEN SHORTWAVE PASSES ACROSS THE EASTERN ZONES.
00Z KOKX SHOWS A STRONG DRY LAYER BETWEEN 975-725 HPA AND THE 00Z
KALY SOUND FROM THE SURFACE-575 HPA. THIS GOES ALONG WAY TO
EXPLAINING WHY ANY MEASURABLE RAINFALL HAS BASICALLY REMAINED
OFFSHORE SO FAR THIS EVENING. THE HRRR AND RUC ARE HANDLING THE
CURRENT SITUATION THE BEST...SO HAVE USED TO UPDATE THE FORECAST
FOR OVERNIGHT...SIGNIFICANTLY LOWERING POPS...ESPECIALLY ACROSS
THE NORTHERN INTERIOR AND NW 1/3 OF THE CWA.
LOOKING FURTHER AT THE NAM - GIVEN THE VORTICITY MINIMA IT
FORECASTS AT 700 HPA OVER THE AREA OVERNIGHT - IT IS SURPRISING
THAT IT IS FORECASTING AS MUCH RAIN AS IT DOES. TYPICALLY WITH
THESE FEATURES AT 700 HPA...IT GOES WITH MINIMAL PRECIPITATION AND
ENDS UP BEING CORRECT. SO THE LOWER POPS ARE ALSO CONSISTENT WITH
THE NAM 700 HPA VORTICITY FIELDS.
STILL LOOKS LIKE THE TWIN FORKS COULD GET SOME LIGHT-MODERATE RAIN
LATE - OTHERWISE AT MOST A TENTH OF AN INCH - WITH MOST AREAS
CLOSER TO 0.01 INCHES.
TEMPERATURE FORECAST ON TRACK BASED ON MAV/MET BLEND WITH NEAR
NORMAL LOWS EXPECTED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
RAIN WILL BE LIKELY DURING THE MORNING HOURS...ESPECIALLY ALONG THE
COAST. THERE WILL BE PLENTY OF LOW-LEVEL MOISTURE IN PLACE WITH A
LOW-LEVEL NE FLOW AND A SW FLOW ALOFT. CONDITIONS WILL DRY OUT
FROM WEST TO EAST DURING THE AFTERNOON HOURS AS THE LOW PASSES TO
THE E AND THEN NE BY EVE. HIGHS WILL BE AROUND 60...WHICH IS
SEVERAL DEGREES BELOW NORMAL.
FOR TUE NIGHT....WITH WEAK LOW-LEVEL WARM ADVECTION...STRATUS
WILL REMAIN ACROSS THE ENTIRE AREA. THERE MAY EVEN BE A LITTLE
DRIZZLE AND/OR LIGHT RAIN DEVELOPING OVERNIGHT WITH AN E/SE
FLOW...ESPECIALLY ACROSS THE HILLS NORTH AND WEST OF NYC. LOWS
WILL ONCE AGAIN BE IN THE MID 40S TO AROUND 50.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE LONGWAVE PATTERN DURING THE LONG TERM PERIOD IS FORECAST TO BE
PROGRESSIVE WITH A LACK OF DEEP AMPLIFICATION. IN
SHORT...RELATIVELY QUICK MOVING SURFACE FEATURES PASS THROUGH THE
FORECAST AREA.
ON WEDNESDAY...A PRE-FRONTAL SURFACE TROUGH MOVES THROUGH. IT LOOKS
LIKE THERE WILL BE DEEP ENOUGH MOISTURE TO WARRANT SLIGHT CHANCE
POPS. BY THE TIME THE TRAILING COLD FRONT ARRIVES LATE IN THE DAY
INTO THE EVENING HOURS....MODELS SHOW DRYING OF THE COLUMN. WILL
THEREFORE CARRY ONLY SLIGHT CHANCE POPS FOR THIS PERIOD. LEANED A
LITTLE MORE TOWARDS THE COOLER NAM MOS DUE TO THE ANTICIPATED CLOUD
COVER...HOWEVER...HIGH TEMPERATURES NEAR NORMAL.
HIGH PRESSURE BUILDS IN ON THURSDAY BEHIND THE COLD FRONT. BUT
BECAUSE OF THE PROGRESSIVE FLOW...RISING HEIGHTS AND SOME AIR MASS
MODIFICATION/MODERATION IS FORECAST BY LATE IN THE DAY. AFTERNOON
HIGHS ARE NOT EXPECTED TO BE SIGNIFICANTLY COOLER...BUT STILL
FALLING BELOW NORMAL LEVELS.
THE NEXT COLD FRONT PASSAGE IS EXPECTED ON FRIDAY. MODELS SHOWING
ONLY LIGHT QPF OUTPUT...SO WON`T BUMP UP POPS JUST YET FROM THE
CURRENT FORECAST OF SLIGHT CHANCE.
HIGH PRESSURE RETURNS ON SATURDAY. THE ORIGIN OF THIS AIRMASS WILL
BE SOMEWHAT MORE DIRECT FROM CANADA WITH LESS TIME TO MODIFY.
THEREFORE EXPECTING TEMPERATURES COOLER THAN THOSE USHERED IN BY
THE HIGH PRESSURE SYSTEM ON THURSDAY.
WITH THE CENTER OF THE HIGH OFFSHORE ON SUNDAY...A RETURN SOUTHERLY
FLOW AND WARM FRONT ENTER THE REGION. MODELS HAVE BEEN TRENDING
FARTHER NORTH REGARDING THE COVERAGE OF QPF ASSOCIATED WITH THE WARM
FRONT. WILL KEEP IN A SLIGHT CHANCE OF SHOWERS NORTH OF THE CITY
LATE SATURDAY INTO SUNDAY MORNING...BUT IT IS LOOKING MORE LIKE A
COMPLETELY DRY UPCOMING WEEKEND ACROSS THE AREA. A TRAILING COLD
FRONT DROPS DOWN FROM THE NORTH ON MONDAY. WITH THE TIMING OF ITS
PASSAGE SOMEWHAT UNCERTAIN...WILL GO WITH SLIGHT CHANCE POPS SUNDAY
NIGHT THROUGH MONDAY NIGHT...BUT MOST OF THE TIME SHOULD BE DRY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE PASSES TO THE EAST TODAY. MAINLY VFR CONDITIONS THE
REST OF TONIGHT...WITH POSSIBLE MVFR CONDITIONS DURING THE DAY
INTO THE COMING NIGHT.
FIRST ROUND OF PCPN NOW PUSHING OFF TO THE EAST. ANOTHER ROUND OF
LIGHT RAIN POSSIBLE BETWEEN 08Z AND 12Z...WITH SOME LINGERING
SHOWERS THROUGH MID MORNING. A PERIOD OF DRY CONDITIONS THEN FOR
THE AFTERNOON WITH HIGH PRESSURE BUILDING BACK IN OVER THE AREA.
VFR CIGS TO START...BUT SHOULD SEE LOWERING OF CIGS TO SUB VFR WITH
THE NEXT ROUND OF PCPN. OVC CONDITIONS THROUGH THE DAY...WITH MOD
CONFIDENCE OF A PERIOD THIS AFTN OF CIGS IMPROVING TO
VFR...RETURNING TO THE LOWER LEVELS AFTER 03Z TONIGHT.
WINDS GENERALLY NE 5-10 KTS...INCREASING TO AROUND 10 KTS DURING
THE DAY AS THE LOW NEARS JUST TO THE EAST.
OUTLOOK FOR 06Z TUESDAY THROUGH SATURDAY...
.TUESDAY NIGHT...MVFR WITH SCT SHOWERS POSSIBLE AFTER 06Z.
.WEDNESDAY...MVFR CONDS POSSIBLE IN -SHRA WITH COLD FRONT
PASSAGE.
.THURSDAY-SATURDAY...VFR.
&&
.MARINE...
MINOR ADJUSTMENTS MADE TO REFLECT LATEST TRENDS IN OBSERVATIONS AND
GUIDANCE. APPEARS WINDS/SEAS WILL REMAIN BENIGN INTO THE OVERNIGHT
HOURS.
A SCA HAS BEEN HOISTED FOR THE OCEAN WATERS TUE-WED MORNING. A
STRENGTHENING NE FLOW AHEAD OF LOW PRESSURE TRACKING NE FROM THE
MID ATLANTIC COAST WILL PRODUCE MARGINAL WIND GUSTS AND SEAS RIGHT
AROUND 5 FT. CONDITIONS WILL BRIEFLY IMPROVE TUE NIGHT AS THE LOW
PASSES TO THE NORTH AND EAST OF THE WATERS. THE REMAINDER OF THE
WATERS SHOULD EXPERIENCE SUB-SCA CONDITIONS TONIGHT-TUESDAY NIGHT.
LOOKS LIKE SUB SCA CONDITIONS SHOULD CONTINUE THROUGH WEDNESDAY
AFTERNOON...BUT WITH A COLD FRONT MOVING THROUGH IN THE
EVENING...WINDS AND SEAS PICK UP...AND MOST IF NOT ALL OF THE AREA
WATERS STAND A GOOD CHANCE OF SCA CONDITIONS. WINDS AND SEAS
SUBSIDE THROUGH THURSDAY WITH HIGH PRESSURE AND A WEAK PRESSURE
GRADIENT IN CONTROL...SO BY LATE IN THE DAY...ALL WATERS ARE
EXPECTED TO HAVE SUB SCA CONDITIONS. ANOTHER COLD FRONT APPROACHES
BEFORE MOVING THROUGH DURING FRIDAY. SCA CONDITIONS PROBABLE ON
SOME OF THE WATERS DURING THIS PERIOD. HIGH PRESSURE WITH A WEAK
PRESSURE RESTORES TRANQUIL CONDITIONS AGAIN ON SATURDAY.
&&
.HYDROLOGY...
RAINFALL FROM LATE THIS AFTERNOON THROUGH TUESDAY MORNING WILL
TOTAL FROM AROUND A FEW HUNDREDTHS OF OF AN INCH ACROSS THE LOWER
HUDSON VALLEY INTO PORTIONS OF NORTHEASTERN NEW JERSEY TO AROUND A
QUARTER TO ONE THIRD OF ACROSS EASTERN LONG ISLAND. THE RAIN WILL
BE MAINLY LIGHT. NO FLOODING IS EXPECTED.
NO SIGNIFICANT RAINFALL EXPECTED MID WEEK THROUGH THE WEEKEND.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 AM EDT
WEDNESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JC/DW
NEAR TERM...MALOIT/MET
SHORT TERM...DW
LONG TERM...JC
AVIATION...SEARS
MARINE...JC/MALOIT/DW
HYDROLOGY...DW
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
241 PM EDT Tue Oct 9 2012
.SYNOPSIS...
Looking at the long wave pattern, we see a trough dominating much of
North America with a northern stream short wave trough moving across
the Upper Midwest. A cut-off low is noted off the California coast.
Surface analysis shows a stationary front across the northern FL
Peninsula with high pressure centered over the TN Valley. Water
vapor imagery indicates dry air over the northeast Gulf Coast
region. Visible satellite shows that the the low stratus deck
continues to gradually erode. However, many locations in Southwest
and South Central GA remained overcast as of 18Z.
&&
.NEAR TERM [through Tonight]...
The main issue for tonight into Wednesday morning is whether or not
there will be a repeat of the low ceilings and patchy fog that we
saw this morning. Examination of our hi-res local WRF time-height
cross section and forecast soundings in BUFKIT does reveal a very
shallow moist layer and inversion near the surface, similar to this
morning. The "long range" RAP forecast valid at 09z tonight is
showing a similar profile. Therefore, we went with persistence and
are forecasting another round of patchy fog to develop late tonight
with an increase in low clouds towards dawn. The low temperature
forecast utilized an even blend of the MAV and MET guidance, which
were fairly similar.
.SHORT TERM [Wednesday through Thursday night]...
The negatively-tilted long wave trough over the eastern CONUS will
deamplify as the primary short wave lifts northeast across the
eastern Great Lakes and New England and the upper low moves into CA.
Surface high pressure will remain in control of our weather locally
which will maintain comfortable temps and humidity levels, even with
the passage of a dry cold front Wednesday night into Thursday. Min
temps will be several degrees below normal through the period. Max
temps will be at or slightly above normal on Wednesday and at or
slightly below normal on Thursday. We do not anticipate another
round of nocturnal low clouds after tonight.
.LONG TERM [Friday through next Tuesday]...
The latest GFS & ECMWF forecast ridging at 500 mb over the Southeast
U.S. through Saturday, followed by a slight fall in the heights into
early next week as trough (currently off the CA coast) translates
quickly northeastward over the Ohio Valley. An area of high pressure
centered to our northeast will provide our forecast area with east
to northeast winds. Both global models forecast the airmass to be
quite dry, though some increase in boundary layer moisture is likely
over the weekend and next week as the boundary layer becomes
modified by its increasing trajectory over the western Atlantic.
Rain chances will be near climo, which this time of year (typically
our driest period) is less than 15%. Temperatures will be a little
above climo, especially during the daytime, with highs in the
generally in the mid 80s (climo is lower 80s). Lows will start off
(Friday & Saturday) in the 50s, then warm into the 60s Sunday
through next Tuesday. Of course, highs will be slightly cooler and
lows slightly warmer than this at the beaches.
&&
.MARINE...
Offshore flow will continue over the waters for the next several
days. Northwest to north winds on Wednesday will veer to the
northeast and increase behind a cold front late Wednesday night into
Thursday. At this time, it appears that winds speeds will remain
just below headline criteria at around 15 kt. As high pressure moves
off the Mid Atlantic coast this weekend, easterly winds could
increase to cautionary levels from late Saturday into Sunday morning.
&&
.AVIATION...
[through 18z Wednesday] The low cloud deck from this morning that
has persisted into the early afternoon hours is finally starting to
break up. It appears as though KABY and KVLD will be the last to
break out into VFR conditions, but this should occur later this
afternoon. However, we are forecasting another round of low cigs and
patchy fog to develop late tonight with IFR conditions expected to
return.
&&
.FIRE WEATHER...
A brief period of low RH values and high dispersions are possible
Wednesday afternoon across northwest Florida, but conditions seem
too marginal for any headlines at this time. Low RH values are
likely again on Thursday afternoon, but dispersions are forecast to
be lower.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 57 85 54 83 55 / 0 0 0 0 0
Panama City 61 84 61 84 61 / 0 0 0 0 0
Dothan 54 82 53 81 54 / 0 0 0 0 0
Albany 55 83 54 81 52 / 0 0 0 0 0
Valdosta 57 84 54 80 54 / 0 0 0 0 0
Cross City 57 86 54 85 57 / 0 0 0 0 0
Apalachicola 62 83 59 82 59 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Short Term/Marine...Wool
Long Term...Fournier
Rest of Discussion...DVD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
936 AM EDT Tue Oct 9 2012
.NEAR TERM...
[Rest of Today] The main issue for today is how long it will take
for the low clouds to break up. So far, they have been expanding
westward through the mid-morning hours with low level northeasterly
flow and now cover the entire forecast area. Looking at the 12z KTAE
sounding, the moisture appears rather shallow overall, but there
is a clear inversion up to around 2500 ft. The 11z RAP viewed in
BUFKIT does not break the inversion until the mid-afternoon hours
around Tallahassee, and it holds low clouds in around Valdosta for
most of the day. Currently, we expect clouds to break from west to
east during the day, but they may hold until the afternoon hours
in areas around Tallahassee and for most of the day in areas
around Valdosta. The previous forecast was already showing a
similar scenario, so only minor adjustments were made to the sky
grids. In terms of temperatures, the current high temperature
forecast is on the low side of guidance given all of the cloud
cover.
&&
.AVIATION...
[Through 12z Wednesday] IFR cigs dominate the area this morning with
a surface inversion in place. These cigs are expected to be slow to
dissipate and will likely linger into the afternoon hours over most
areas.
&&
.PREV DISCUSSION 634 AM EDT Tue Oct 9 2012
.SHORT TERM...
[Tonight through Thursday] The broad trough aloft will keep
afternoon temperatures near or slightly below average through
Thursday. Overnight temperatures will remain about 5 degrees below
average through the period. At the surface, dry northerly flow
provided by high pressure will keep rain out of the forecast. It
appears as though benign weather will continue for several days.
.LONG TERM...
[Thursday night through next Tuesday] The latest GFS & ECMWF
forecast ridging at 500 mb over the Southeast U.S. through
Saturday, followed by a slight fall in the heights into early next
week as trough (currently off the CA coast) translates quickly
northeastward over the Ohio Valley. An area of high pressure
centered to our northeast will provide our forecast area with east
to northeast winds. Both global models forecast the airmass to be
quite dry, though some increase in boundary layer moisture is
likely over the weekend and next week as the boundary layer
becomes modified by its increasing trajectory over the western
Atlantic. Rain chances will be near climo, which this time of year
(typically our driest period) is less than 15%. Temperatures will
be a little above climo, especially during the daytime, with highs
in the generally in the mid 80s (climo is lower 80s). Lows will
start off (Friday & Saturday) in the 50s, then warm into the 60s
Sunday through next Tuesday. Of course, highs will be slightly
cooler and lows slightly warmer than this at the beaches.
&&
.MARINE...
Winds will continue subsiding through the day today as the calm
center of high pressure moves nearer to the Gulf. By Thursday, a
reinforcing area of high pressure will move into the Gulf,
increasing winds and seas through the weekend. Cautionary winds
are expected for at least a brief period of time over the weekend.
&&
.FIRE WEATHER...
With a drier airmass moving into the region, a brief period of
locally "critical" low RH levels is possible Wednesday afternoon,
but it`s probably too marginal for any sort of Fire Weather Watch at
this time. A slightly longer period of low RH is possible Thursday
afternoon, but it`s too early to tell if other factors (such as ERC
and dispersion) will warrant any watches or warnings. GA & AL will
probably not be quite dry enough for Red Flag conditions on these
days.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 78 56 85 57 83 / 0 0 0 0 0
Panama City 79 61 82 62 81 / 0 0 0 0 0
Dothan 77 53 83 53 80 / 0 0 0 0 0
Albany 75 54 83 53 80 / 0 0 0 0 0
Valdosta 71 55 84 55 81 / 0 0 0 0 0
Cross City 78 58 86 57 84 / 0 0 0 0 0
Apalachicola 80 61 82 63 81 / 0 0 0 0 0
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
Near Term/Aviation...DVD
Short Term/Marine...Harrigan
Long Term/Fire Wx...Fournier
AREA FORECAST DISCUSSION
NWS GOODLAND KS
530 PM MDT WED OCT 10 2012
.UPDATE...
ISSUED AT 225 PM MDT WED OCT 10 2012
MADE MINOR ADJUSTMENT TO WX/SKY GRIDS FOR TONIGHT PERIOD...TO
INCREASE SKY COVER AND ADD PATCHY FOG. NAM/RUC BOTH SHOWING DECENT
BL MOISTURE ADVECTING NORTH. WITH BETTER CLEARING SOUTH
COULDNT RULE OUT STRATUS/FOG DEVELOPING AND THEN ADVECTING NORTH
OUT OF SE CO AND SW KS. NOT SURE HOW FAR NORTH THIS WILL GET...SO
I ONLY LIMITED IT TO THE FAR SOUTHERN TIER OF COUNTIES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 1203 PM MDT WED OCT 10 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW SIMILAR PATTERN AS THE
LAST FEW DAYS...WITH BROAD TROUGH ACROSS CANADA EXTENDING SOUTH
ACROSS THE EASTERN US. A REX BLOCK IS ALSO STILL IN PLACE OFF THE
WESTERN US...WITH A CLOSED UPPER LOW BEGINNING TO MOVE OVER THE
CENTRAL CALIFORNIA COAST. A SHORTWAVE RIDGE EXTENDS NORTH OVER
WESTERN COLORADO AND TOWARDS THE GREAT BASIN. AT THE SURFACE HIGH
PRESSURE EXTENDS FROM THE CENTRAL MISSISSIPPI VALLEY WEST INTO
CENTRAL KANSAS. A LEE TROUGH IS DEEPENING OVER EASTERN
COLORADO...WITH INCREASING PRESSURE GRADIENT OVER WESTERN KS BETWEEN
THESE FEATURES.
GOOD WAA OVERNIGHT TONIGHT...COMBINED WITH MID-HIGH CLOUD COVER
COMPLICATES THE LOW TEMPERATURE. WINDS SHOULD DIMINISH AROUND
SUNSET AS DAYTIME HEATING COMES TO AN END...AND THE LEE TROUGH
AXIS SHIFTS EAST OVER THE CWA...SO WINDS SHOULD NOT BE AS MUCH OF
AN ISSUE. TEMPERATURES CURRENTLY EXPECTED TO BE IN THE 40S ACROSS
MOST OF THE AREA. IF CLOUD COVER WERE TO BE MORE EXTENSIVE WE
MAY SEE OVERNIGHT TEMPS CLOSER TO 50F AT SOME LOCATIONS.
A COLD FRONT WILL PUSH SOUTH OVER THE CWA AS A SHORTWAVE TROUGH
MOVES FROM SOUTHERN CANADA INTO NORTHERN MINNESOTA THURSDAY. WITH
VERY LITTLE IN MOISTURE IN PLACE AND BEST LARGE SCALE ASCENT WELL TO
THE NORTH AND EAST...NO PRECIP IS EXPECTED. LATEST GUIDANCE FAVORS
FRONTAL PASSAGE AROUND 15Z ACROSS MOST OF THE CWA...AND AROUND 18Z
ACROSS THE SOUTHERN HALF OF THE CWA. I HAVE TRENDED TEMPS DOWN
ACCORDINGLY...WITH HIGHS IN THE UPPER 50S/LOW 60S ACROSS THE
NORTH...AND NEAR 70 ACROSS THE SOUTH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1251 PM MDT WED OCT 10 2012
SYSTEM CURRENTLY OVER SOUTHERN CALIFORNIA WILL LIFT OUT ACROSS THE
SOUTHERN AND CENTRAL ROCKIES FRIDAY AND SATURDAY. BEST LIFT LOCALLY
WILL OCCUR FRIDAY AFTERNOON THROUGH FRIDAY NIGHT. COOL AND STABLE
CONDITIONS ARE FORECAST FOR FRIDAY WHICH WILL RESULT IN SURFACE
INSTABILITY OF ZERO. HOWEVER...THERE IS WEAK ELEVATED INSTABILITY
AND DEEP LAYER SHEAR IS UP TO 40KTS. THERE IS SOME WEAK SURFACE
BASED INSTABILITY FORECAST LATE FRIDAY NIGHT...SO CANNOT RULE OUT
THE POSSIBILITY OF A SEVERE STORM MOVING INTO AREAS SOUTH OF INTERSTATE
70 FROM SOUTHWEST KANSAS FRIDAY NIGHT. AFTER MIDNIGHT A MASSIVE
MID LEVEL DRY SLOT WILL OVERSPREAD THE FORECAST AREA...ENDING THE
PRECIPITATION CHANCES FOR ALL BUT THE FAR NORTHWEST CORNER WHICH
COULD RECEIVE SOME LIGHT WRAPAROUND PRECIPITATION THROUGH SATURDAY
MORNING. CLEARING IS EXPECTED BY SATURDAY AFTERNOON FOR THE ENTIRE
AREA.
RIDGING IS FORECAST FOR SUNDAY AND MONDAY WITH ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS. NEXT SHORTWAVE TROUGH WILL
APPROACH THE NORTHERN ROCKIES MONDAY NIGHT AND MOVE ACROSS THE
AREA TUESDAY OR WEDNESDAY. HOWEVER...MOISTURE APPEARS TO BE
LACKING FOR PRECIPITATION CHANCES. ASSOCIATED SURFACE COLD FRONT
COULD PRODUCE WINDY CONDITIONS TUESDAY NIGHT AND WEDNESDAY GIVEN
STRONG UPPER JET IN THE VICINITY. ONLY SLIGHT COOLING IS EXPECTED
WITH FRONTAL PASSAGE GIVEN PACIFIC ORIGIN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 530 PM MDT WED OCT 10 2012
VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE PERIOD AT BOTH
GLD AND MCK. A FEW MORE HOURS OF LIGHT SOUTHERLY WINDS BEFORE THEY
BECOME LIGHT AND VARIABLE IN DIRECTION OVERNIGHT. A COLD FRONT
MOVING THROUGH FROM THE NORTH TOMORROW MID-MORNING WILL INCREASE
WINDS...BECOMING NORTHERLY BEHIND THE FRONT WITH GUSTS UP TO 25KTS. THE
FRONT WILL BRING A FEW MID TO HIGH LEVEL CLOUDS...BUT NO
PRECIPITATION IS EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...024
AVIATION...JJM/LOCKHART
AREA FORECAST DISCUSSION
NWS GOODLAND KS
236 PM MDT TUE OCT 9 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 233 PM MDT TUE OCT 9 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW BROAD TROUGH IN
STILL IN PLACE ACROSS THE US. A POSITIVELY TILTED LONGWAVE TROUGH
AXIS CURRENTLY EXTENDS SOUTHWEST ALONG THE UPPER MISSISSIPPI VALLEY
ACROSS CENTRAL KANSAS. REX BLOCK IS STILL IN PLACE OFF THE
WESTERN...WITH ASSOCIATED CLOSED LOW CENTERED JUST OFF THE
CALIFORNIA COAST. AT THE SURFACE HIGH PRESSURE IS CURRENTLY IN PLACE
ACROSS THE NORTHERN AND HIGH PLAINS REGIONS BEHIND A COLD FRONT THAT
MOVED THROUGH WESTERN KANSAS THIS MORNING.
SKIES SHOULD CLEAR ACROSS THE CWA AS STRATUS ACROSS THE WESTERN
CWA SHIFTS WEST AND DISSIPATES. THE REMAINDER OF THE NIGHT SHOULD
BE MOSTLY CLEAR WITH ONLY PASSING HIGH CLOUDS. THERE IS SOME
INDICATION OF STRATUS/FOG DEVELOPMENT OVER EASTERN
COLORADO...HOWEVER THIS LOOKS TO REMAIN JUST WEST OF OUR CWA...SO
NO MENTION IS INCLUDED IN THE FORECAST AT THIS TIME.
WINDS WILL DECREASE LATE THIS AFTERNOON AND EARLY THIS EVENING AS
HIGH PRESSURE CONTINUES TO BUILD SOUTH. WITH A COOL AIRMASS IN PLACE
MOST OF THE CWA SHOULD SEE TEMPS DROP TO THE 30-35F RANGE...WITH THE
COLDEST TEMPS IN THE EAST. WINDS WILL INCREASE FROM THE SOUTHWEST IN
THE WEST TOWARDS SUNRISE...WHICH WILL ALSO HELP BRING TEMPS BACK UP
ABOVE FREEZING. DESPITE THIS...THERE IS STILL A WINDOW IN THE WEST
BETWEEN 06-09Z WHEN MANY LOCATIONS WILL BE WITHIN FROST ADVISORY
CRITERIA. LOCATIONS NORTH AND EAST HAVE ALREADY SEEN A HARD
FREEZE...SO I ONLY ISSUED A FROST ADVISORY FOR THE SOUTHWEST
QUADRANT OF MY CWA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 233 PM MDT TUE OCT 9 2012
UPPER FLOW WILL BE NORTHWEST WEDNESDAY NIGHT TRANSITIONING TO A MORE
WESTERLY FLOW AS A RIDGE BUILDS INTO THE CENTRAL ROCKIES ON
THURSDAY. FLOW BECOMES SOUTHWESTERLY THURSDAY NIGHT AHEAD OF AN
UPPER THAT MOVES TO A POSITION WEST OF THE FOUR CORNERS REGION
FRIDAY. SURFACE HIGH PRESSURE WILL CONTINUE OVER THE CENTRAL PLAINS
WEDNESDAY NIGHT. LOW PRESSURE WILL MOVE INTO EASTERN COLORADO
THURSDAY. A COLD FRONT WILL MOVE INTO NORTHWEST KANSAS THURSDAY
AFTERNOON/NIGHT FOLLOWED BY HIGH PRESSURE FRIDAY.
DRY CONDITIONS WILL CONTINIUE THROUGH THURSDAY WITH LACK OF FORCING
AND MOISTURE. LATE THURSDAY NIGHT/EARLY FRIDAY MORNING DYNAMICS
APPROACH THE FA FROM THE SOUTHWEST. PLAN TO KEEP A SMALL AREA OF
SLIGHT CHANCE/CHANCE POPS ACROSS THE EXTREME SOUTHERN FA.
PRECIPITATION APPEARS MORE LIKELY FRIDAY SO HAVE INCREASED POPS TO
HIGHER CHANCE POPS.
MIN TEMPERATURES WILL RANGE FROM THE LOWER 40S WEDNESDAY NIGHT
COOLING TO THE UPPER 30S THURSDAY NIGHT. MAX TEMPERATURES THURSDAY
WILL BE AROUND 70. CLOUDS AND PRECIPITATION WILL KEEP HIGH
TEMPERATURES FRIDAY IN THE UPPER 50S
FOR FRIDAY NIGHT THROUGH MONDAY...THE UPPER TROUGH WILL BE OVER THE
CENTRAL ROCKIES FRIDAY NIGHT AND LIFT NORTHEAST INTO NORTHCENTRAL
NEBRASKA SATURDAY. NORTHWEST FLOW WILL RESUME SUNDAY AND CONTINUE
THROUGH TUESDAY. A SURFACE TROUGH WILL BE OVER EASTERN COLORADO
FRIDAY NIGHT. THIS AREA OF LOW PRESSURE WILL MOVE INTO NORTHEAST
NEBRASKA SATURDAY FOLLOWED BY HIGH PRESSURE SATURDAY NIGHT AND
SUNDAY. ANOTHER TROUGH WILL DEVELOP IN EASTERN COLORADO MONDAY
REPLACED BY HIGH PRESSURE TUESDAY.
GOOD DYNAMICS AND MOISTURE WILL SUPPORT HIGH CHANCE AND LIKELY POPS
FRIDAY NIGHT. PRECIPITATION CHANCES LOWER TO SLIGHT CHANCE OVER THE
FAR NORTHWEST FA SATURDAY AS THE SYSTEM MOVES INTO NEBRASKA.
SUBSIDENCE MOVES IN BEHIND THIS SYSTEM. POPS WILL BE NIL FROM
SATURDAY THROUGH TUESDAY. MIN TEMPERATURES WILL BE IN THE MID 40S
FOR THIS PART OF THE FORECAST. MAX TEMPERATURES WILL RISE TO AROUND
70 EACH DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1122 AM MDT TUE OCT 9 2012
MVFR STRATUS DECK CONTINUES TO MOVE SOUTH TO SOUTHWEST OVER THE
AREA...WITH THE BACK EDGE ALONG THE KS/NE STATE LINE. BASED ON
TIMING FROM SATELLITE...I EXPECT VFR CONDITIONS AT KMCK BY 19Z.
ITS A TOUGHER CALL AT KGLD...WHERE STRATUS IS MORE EXTENSIVE. IT
DOES APPEAR THAT STRATUS IS BEGINNING TO DISSIPATE ALONG THE
NORTHERN EDGE OF THE STRATUS FIELD IN SW NEBRASKA. THIS MATCHES
TRENDS BY SHORT RANGE GUIDANCE. FOR NOW I AM ANTICIPATING MVFR
CIGS AT KGLD UNTIL 20-21Z. AFTER STRATUS CLEARS AT BOTH TERMINALS
THIS AFTERNOON...VFR CONDITIONS SHOULD PREVAIL THROUGH THE
REMAINING TAF PERIOD. GUSTY WINDS SHOULD DIMINISH THIS AFTERNOON
AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH. LIGHT AND
VARIABLE WINDS ARE THEN EXPECTED THROUGH MOST OF THE NIGHT...WITH
GUSTY SOUTH-SOUTHWEST WINDS REDEVELOPING OVER KGLD WEDNESDAY
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FROST ADVISORY FROM MIDNIGHT MDT /1 AM CDT/ TONIGHT TO 9 AM MDT
/10 AM CDT/ WEDNESDAY FOR KSZ013-014-027-028-041-042.
CO...FROST ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM MDT WEDNESDAY FOR
COZ091-092.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1135 AM MDT TUE OCT 9 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 401 AM MDT TUE OCT 9 2012
FORECAST CONCERNS WILL BE WINDS TODAY AND WEDNESDAY...HOW COOL TO
MAKE TODAY...HOW MUCH TO WARM UP THE NEXT TWO DAYS...AND CHANCE OF
PRECIPITATION LATE IN THE SHORT TERM. SATELLITE CONTINUING TO SHOW AN
AMPLIFIED AND BLOCKY FLOW FROM THE PACIFIC INTO EASTERN NORTH
AMERICA. UPPER LOW NEAR HAS MOVED CLOSER TO THE COAST BUT HAS BEGUN
TO TAKE A MORE SOUTHWARD COURSE. STRONG SYSTEM DIGGING INTO THE NORTH
CENTRAL PORTION OF THE COUNTRY IS PUSHING A COLD FRONT THROUGH THE
AREA AT THIS TIME.
AT JET LEVEL...MODELS WERE CLOSE WITH THE NAM DOING A LITTLE BETTER
THAN THE REMAINING OUTPUT. AT MID LEVELS...MODELS TENDED TO HAVE THE
FEATURES/HEIGHT FIELD TOO FAR SOUTH AND WEST. OVERALL THE CANADIAN...
GFS...AND UKMET WERE DOING THE BEST. HOWEVER...THE NAM DID BETTER ON
THE NORTH CENTRAL SYSTEM. THE MODELS WERE NOT QUITE FAST ENOUGH
WITH THE FRONT. THE HRRR AND RUC WERE DOING THE BEST FOLLOWED BY THE
NAM ON THAT AND OVERALL. ON THE LOW LEVEL THERMAL FIELD THE MODELS
OVERALL WERE CLOSE. HOWEVER...THEY TENDED TO NOT HAVE THE COLD AIR
TO OUR NORTH FAR ENOUGH SOUTH AND WEST. IN THIS AREA THE CANADIAN
AND THE UKMET WERE DOING THE BEST.
TODAY/TONIGHT...AFTER SPEEDING UP THE FRONT THE MODELS HAVE NOW
SLOWED THE FRONT DOWN. LOOKS LIKE IT WILL BE THROUGH THE NORTHWEST
HALF OF THE AREA BY 12Z AND THROUGH ALL THE AREA BY 15Z OR SO.
WINDS LOOK TO STAY UNDER WIND ADVISORY CRITERIA. THE TIGHTEST
GRADIENT AND 3 HOUR PRESSURE RISES ARE DONE BY 15Z AND THEN THEY
START STEADILY DECREASING. BY THE TIME THE SUN COMES UP AND STARTS
THE HEATING...WHICH MAY BE LIMITED BY CLOUD COVER...THOSE
PARAMETERS WILL HAVE BEGUN THIS DECREASE.
THE MODELS ALSO LOOK LIKE THEY HAVE BACK OFF A LITTLE ON THE STRATUS
BEHIND IT. SOME OTHER MID AND HIGH LEVEL CLOUDS WILL MOVE THROUGH AS
WELL DUE TO THE SHORTWAVE TROUGH AND A RIGHT REAR QUADRANT OF THE
JET MOVES FROM NORTH TO SOUTH ACROSS THE AREA THIS MORNING. AT THE
VERY LEAST THIS IS GOING TO PRODUCE THICK CLOUD COVER DURING THIS
TIME. SUBSIDENCE AND CLEARING SHOULD OCCUR BEGINNING AT 18Z. MODELS
HAVE BEEN TRENDING COOLER WITH THE TEMPERATURES AND FOLLOWED THAT
TREND IN THE GRIDS.
VERY LIGHT WINDS AND LOW DEWPOINTS WITH LITTLE IF ANY CLOUD COVER
TONIGHT. THE BEST RADIATIONAL CONDITIONS OCCUR OVER THE NORTHEAST
AND EASTERN COUNTIES AND LOWERED OVERNIGHT LOWS AS A RESULT.
WEDNESDAY/WEDNESDAY NIGHT...SURFACE RIDGE MOVES OFF AS LEE TROUGH
DEVELOPS. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS INCREASE BY
18Z WHICH SHOULD LEAD TO AT LEAST BREEZY AND POSSIBLY WINDY
CONDITIONS DEVELOPING. HIGHER CLOUDS INCREASE DURING THE AFTERNOON IN
THE WEST. MODELS BEGIN DIFFERING HERE ON THE AMOUNT OF WARMUP. WILL
HAVE A COLD START...ESPECIALLY EAST. MODELS HAVE BEEN REALLY ALL
OVER THE PLACE RECENTLY. USING THE 2 METER TEMPERATURES THAT HAVE
BEEN DOING THE BEST AND RECENT 850 MB TEMPERATURE BIASES LED TO ONLY
A SLIGHT ADJUSTMENT TO THE CURRENT FORECAST.
RIGHT REAR QUADRANT OF THE JET MOVES SLOWLY NORTH TO SOUTH ACROSS
THE AREA DURING THE NIGHT. THIS WILL INCREASE CLOUDS PLUS LOW LEVEL
WARM AIR ADVECTION INCREASES THROUGH THE NIGHT. SO WILL BE MUCH
WARMER THAN IT HAS RECENTLY.
THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT REMAINS OVER OR NEAR
THE NORTHERN PORTION OF THE AREA THROUGH THE DAY. UPPER RIDGE
BUILDS TO OUR WEST IN ADVANCE OF UPPER LOW IN THE DESERT SOUTHWEST.
MODELS HAVE SLOWED IN THEIR PROGRESSION OF THIS FEATURE. THIS HAS
ALLOWED A WEST TO WEST NORTHWEST FLOW TO REMAIN A LITTLE LONGER
OVER THE AREA. SO WILL PROBABLY HAVE A LITTLE MORE CLOUD COVER...
ESPECIALLY IN THE NORTH.
BUT WHAT IS MORE IMPORTANT...THIS IS ALLOWING A WEAK SHORTWAVE
TROUGH IN THE NORTH CENTRAL PORTION OF THE COUNTRY TO PUSH A
BACKDOOR COLD FRONT THROUGH THE AREA. MODELS DO SHOW THIS IN A
SIMILAR FASHION BUT DIFFER DRAMATICALLY ON HOW MUCH TO COOL OFF THE
TEMPERATURES. THERE IS A 10 TO 15 DEGREE DIFFERENCE. HEIGHTS RISE
OVER THE PREVIOUS DAY WITH SIMILAR MID LEVEL TEMPERATURES. THE NAM
NWP AND 2 METER IS BY FAR THE WARMEST WITH THE SREF AND UKMET NEXT IN
LINE. THE GFS AND ECMWF FOLLOWED BY THE CANADIAN ARE THE COOLEST.
WHAT ENDED UP DOING WAS SPLITTING THE DIFFERENCE BETWEEN THE
EXTREMES. HOWEVER...COULD SEE EITHER EXTREME OCCURRING.
AGAIN THE MODELS DIFFER ON HOW FAR SOUTH TO TAKE THE FRONT WHICH
WILL AFFECT PRECIPITATION CHANCES DURING THE NIGHT. AGAIN MODELS ARE
SPLIT NEARLY EVENLY ON THE DIFFERENT SOLUTIONS. USUALLY IN THESE
SITUATIONS THE MODEL WITH BETTER TERRAIN ENDS UP HAVING A BETTER
DEPICTION OF THE FRONT. CONSIDERING THE SYNOPTIC PATTERN BELIEVE THE
FARTHER NORTH SOLUTIONS OF WHERE THE FRONT STALLS OUT ARE THE BEST.
THIS ENDS UP BEING THE NAM...UKMET AND CANADIAN. THE FRONT STALLS
OVER SOUTHEAST COLORADO AND SOUTHWEST KANSAS EARLY AND THEN MOVES
NORTH OVERNIGHT.
EVEN THOUGH THE MODELS ARE SLOWER THEY SHOOT OUT A SHORTWAVE INTO
THE AREA AFTER 06Z. ALSO A STRONGER RIGHT REAR QUADRANT
DEVELOPS/MOVES OVER THE AREA...ESPECIALLY AFTER 06Z. ELEVATED CAPE
DEVELOPS OVER THE AREA...ALTHOUGH THEY DIFFER HOW MUCH AND HOW FAR
NORTH. THERE IS ALSO LIMITED ELEVATED CINH. STRONG ISENTROPIC LIFT
DEVELOPS ON THE 300 SURFACE. SATURATED PRESSURE DEFICITS ALSO
DRAMATICALLY DECREASE AS WELL. THE 06Z NAM CAME IN EVEN MORE
FAVORABLE THAN THE 00Z. ALL THIS PLUS SREF AND GEFS PROBABILITIES
SUPPORT HAVING SLIGHT CHANCE TO LOW CHANCE POPS IN OUR SOUTHERN
PORTION AFTER 06Z.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 401 AM MDT TUE OCT 9 2012
RELATIVELY LARGE EARLY SEASON CUTOFF LOW WILL MOVE ACROSS SOUTHEAST
UTAH AND THEN OVER THE CENTRAL ROCKIES INTO THE NEBRASKA PANHANDLE
BY SATURDAY. CYCLOGENESIS WILL INCREASE AS THIS SYSTEM MOVES OUT
ONTO THE PLAINS. INSTABILITY AXIS WILL BE POSITIONED ACROSS THE
COLORADO/KANSAS BORDER AND EXTENDING SOUTH ACROSS TEXAS AND EASTWARD
ACROSS MUCH OF THE REST OF THE STATE. MODELS DIFFER FROM YESTERDAY
IN THAT BOTH THE EC AND THE GFS TAKE THE LOW THROUGH EASTERN
NEBRASKA PANHANDLE AND INTO SOUTHERN MINNESOTA. COMBINED WITH
THIS...A 250 MB JET STREAK WILL BE IN PLACE ACROSS NEW MEXICO AND
THEN UP THROUGH WESTERN KANSAS. AT THE SURFACE...LEE TROUGH ACROSS
EASTERN COLORADO WILL QUICKLY DEEPEN AS COLD FRONT BEGINS TO MOVE
THROUGH THE REGION. CHANCES FOR PRECIPITATION STILL LOOK TO BE ON
TRACK WITH THIS SYSTEM...WITH A CHANCE THAT SOME OF THESE STORMS MAY
BE SEVERE. MUCH OF THE SEVERE ACTIVITY APPEARS TO INITIATE WELL EAST
OF THE CWA AS BETTER OVERALL PROFILE SETS UP ACROSS IOWA AND
MISSOURI. SYSTEM DOES NOT APPEAR TO USHER IN TOO MUCH COLD AIR BUT
DOES TRY TO DRY SLOT THE AREA BY SATURDAY MORNING. IF THIS REIGNS
TRUE...SECTIONS OF THE AREA MAY SEE LITTLE TO NO PRECIPITATION.
SUBSIDENCE WILL QUICKLY MOVE IN BEHIND THE DEPARTING SYSTEM AHEAD OF
ANOTHER COLD FRONT THAT WILL MOVE ACROSS THE AREA BY EARLY NEXT
WEEK. A SHORTWAVE TROUGH WILL ALSO MOVE ACROSS THE NORTHERN PLAINS
DURING THIS TIME...WITH PRECIPITATION CHANGES REMAINING WELL NORTH
OF THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1122 AM MDT TUE OCT 9 2012
MVFR STRATUS DECK CONTINUES TO MOVE SOUTH TO SOUTHWEST OVER THE
AREA...WITH THE BACK EDGE ALONG THE KS/NE STATE LINE. BASED ON
TIMING FROM SATELLITE...I EXPECT VFR CONDITIONS AT KMCK BY 19Z.
ITS A TOUGHER CALL AT KGLD...WHERE STRATUS IS MORE EXTENSIVE. IT
DOES APPEAR THAT STRATUS IS BEGINNING TO DISSIPATE ALONG THE
NORTHERN EDGE OF THE STRATUS FIELD IN SW NEBRASKA. THIS MATCHES
TRENDS BY SHORT RANGE GUIDANCE. FOR NOW I AM ANTICIPATING MVFR
CIGS AT KGLD UNTIL 20-21Z. AFTER STRATUS CLEARS AT BOTH TERMINALS
THIS AFTERNOON...VFR CONDITIONS SHOULD PREVAIL THROUGH THE
REMAINING TAF PERIOD. GUSTY WINDS SHOULD DIMINISH THIS AFTERNOON
AS HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTH. LIGHT AND
VARIABLE WINDS ARE THEN EXPECTED THROUGH MOST OF THE NIGHT...WITH
GUSTY SOUTH-SOUTHWEST WINDS REDEVELOPING OVER KGLD WEDNESDAY
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...PMM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
529 AM MDT TUE OCT 9 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 401 AM MDT TUE OCT 9 2012
FORECAST CONCERNS WILL BE WINDS TODAY AND WEDNESDAY...HOW COOL TO
MAKE TODAY...HOW MUCH TO WARM UP THE NEXT TWO DAYS...AND CHANCE OF
PRECIPITATION LATE IN THE SHORT TERM. SATELLITE CONTINUING TO SHOW AN
AMPLIFIED AND BLOCKY FLOW FROM THE PACIFIC INTO EASTERN NORTH
AMERICA. UPPER LOW NEAR HAS MOVED CLOSER TO THE COAST BUT HAS BEGUN
TO TAKE A MORE SOUTHWARD COURSE. STRONG SYSTEM DIGGING INTO THE NORTH
CENTRAL PORTION OF THE COUNTRY IS PUSHING A COLD FRONT THROUGH THE
AREA AT THIS TIME.
AT JET LEVEL...MODELS WERE CLOSE WITH THE NAM DOING A LITTLE BETTER
THAN THE REMAINING OUTPUT. AT MID LEVELS...MODELS TENDED TO HAVE THE
FEATURES/HEIGHT FIELD TOO FAR SOUTH AND WEST. OVERALL THE CANADIAN...
GFS...AND UKMET WERE DOING THE BEST. HOWEVER...THE NAM DID BETTER ON
THE NORTH CENTRAL SYSTEM. THE MODELS WERE NOT QUITE FAST ENOUGH
WITH THE FRONT. THE HRRR AND RUC WERE DOING THE BEST FOLLOWED BY THE
NAM ON THAT AND OVERALL. ON THE LOW LEVEL THERMAL FIELD THE MODELS
OVERALL WERE CLOSE. HOWEVER...THEY TENDED TO NOT HAVE THE COLD AIR
TO OUR NORTH FAR ENOUGH SOUTH AND WEST. IN THIS AREA THE CANADIAN
AND THE UKMET WERE DOING THE BEST.
TODAY/TONIGHT...AFTER SPEEDING UP THE FRONT THE MODELS HAVE NOW
SLOWED THE FRONT DOWN. LOOKS LIKE IT WILL BE THROUGH THE NORTHWEST
HALF OF THE AREA BY 12Z AND THROUGH ALL THE AREA BY 15Z OR SO.
WINDS LOOK TO STAY UNDER WIND ADVISORY CRITERIA. THE TIGHTEST
GRADIENT AND 3 HOUR PRESSURE RISES ARE DONE BY 15Z AND THEN THEY
START STEADILY DECREASING. BY THE TIME THE SUN COMES UP AND STARTS
THE HEATING...WHICH MAY BE LIMITED BY CLOUD COVER...THOSE
PARAMETERS WILL HAVE BEGUN THIS DECREASE.
THE MODELS ALSO LOOK LIKE THEY HAVE BACK OFF A LITTLE ON THE STRATUS
BEHIND IT. SOME OTHER MID AND HIGH LEVEL CLOUDS WILL MOVE THROUGH AS
WELL DUE TO THE SHORTWAVE TROUGH AND A RIGHT REAR QUADRANT OF THE
JET MOVES FROM NORTH TO SOUTH ACROSS THE AREA THIS MORNING. AT THE
VERY LEAST THIS IS GOING TO PRODUCE THICK CLOUD COVER DURING THIS
TIME. SUBSIDENCE AND CLEARING SHOULD OCCUR BEGINNING AT 18Z. MODELS
HAVE BEEN TRENDING COOLER WITH THE TEMPERATURES AND FOLLOWED THAT
TREND IN THE GRIDS.
VERY LIGHT WINDS AND LOW DEWPOINTS WITH LITTLE IF ANY CLOUD COVER
TONIGHT. THE BEST RADIATIONAL CONDITIONS OCCUR OVER THE NORTHEAST
AND EASTERN COUNTIES AND LOWERED OVERNIGHT LOWS AS A RESULT.
WEDNESDAY/WEDNESDAY NIGHT...SURFACE RIDGE MOVES OFF AS LEE TROUGH
DEVELOPS. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS INCREASE BY
18Z WHICH SHOULD LEAD TO AT LEAST BREEZY AND POSSIBLY WINDY
CONDITIONS DEVELOPING. HIGHER CLOUDS INCREASE DURING THE AFTERNOON IN
THE WEST. MODELS BEGIN DIFFERING HERE ON THE AMOUNT OF WARMUP. WILL
HAVE A COLD START...ESPECIALLY EAST. MODELS HAVE BEEN REALLY ALL
OVER THE PLACE RECENTLY. USING THE 2 METER TEMPERATURES THAT HAVE
BEEN DOING THE BEST AND RECENT 850 MB TEMPERATURE BIASES LED TO ONLY
A SLIGHT ADJUSTMENT TO THE CURRENT FORECAST.
RIGHT REAR QUADRANT OF THE JET MOVES SLOWLY NORTH TO SOUTH ACROSS
THE AREA DURING THE NIGHT. THIS WILL INCREASE CLOUDS PLUS LOW LEVEL
WARM AIR ADVECTION INCREASES THROUGH THE NIGHT. SO WILL BE MUCH
WARMER THAN IT HAS RECENTLY.
THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT REMAINS OVER OR NEAR
THE NORTHERN PORTION OF THE AREA THROUGH THE DAY. UPPER RIDGE
BUILDS TO OUR WEST IN ADVANCE OF UPPER LOW IN THE DESERT SOUTHWEST.
MODELS HAVE SLOWED IN THEIR PROGRESSION OF THIS FEATURE. THIS HAS
ALLOWED A WEST TO WEST NORTHWEST FLOW TO REMAIN A LITTLE LONGER
OVER THE AREA. SO WILL PROBABLY HAVE A LITTLE MORE CLOUD COVER...
ESPECIALLY IN THE NORTH.
BUT WHAT IS MORE IMPORTANT...THIS IS ALLOWING A WEAK SHORTWAVE
TROUGH IN THE NORTH CENTRAL PORTION OF THE COUNTRY TO PUSH A
BACKDOOR COLD FRONT THROUGH THE AREA. MODELS DO SHOW THIS IN A
SIMILAR FASHION BUT DIFFER DRAMATICALLY ON HOW MUCH TO COOL OFF THE
TEMPERATURES. THERE IS A 10 TO 15 DEGREE DIFFERENCE. HEIGHTS RISE
OVER THE PREVIOUS DAY WITH SIMILAR MID LEVEL TEMPERATURES. THE NAM
NWP AND 2 METER IS BY FAR THE WARMEST WITH THE SREF AND UKMET NEXT IN
LINE. THE GFS AND ECMWF FOLLOWED BY THE CANADIAN ARE THE COOLEST.
WHAT ENDED UP DOING WAS SPLITTING THE DIFFERENCE BETWEEN THE
EXTREMES. HOWEVER...COULD SEE EITHER EXTREME OCCURRING.
AGAIN THE MODELS DIFFER ON HOW FAR SOUTH TO TAKE THE FRONT WHICH
WILL AFFECT PRECIPITATION CHANCES DURING THE NIGHT. AGAIN MODELS ARE
SPLIT NEARLY EVENLY ON THE DIFFERENT SOLUTIONS. USUALLY IN THESE
SITUATIONS THE MODEL WITH BETTER TERRAIN ENDS UP HAVING A BETTER
DEPICTION OF THE FRONT. CONSIDERING THE SYNOPTIC PATTERN BELIEVE THE
FARTHER NORTH SOLUTIONS OF WHERE THE FRONT STALLS OUT ARE THE BEST.
THIS ENDS UP BEING THE NAM...UKMET AND CANADIAN. THE FRONT STALLS
OVER SOUTHEAST COLORADO AND SOUTHWEST KANSAS EARLY AND THEN MOVES
NORTH OVERNIGHT.
EVEN THOUGH THE MODELS ARE SLOWER THEY SHOOT OUT A SHORTWAVE INTO
THE AREA AFTER 06Z. ALSO A STRONGER RIGHT REAR QUADRANT
DEVELOPS/MOVES OVER THE AREA...ESPECIALLY AFTER 06Z. ELEVATED CAPE
DEVELOPS OVER THE AREA...ALTHOUGH THEY DIFFER HOW MUCH AND HOW FAR
NORTH. THERE IS ALSO LIMITED ELEVATED CINH. STRONG ISENTROPIC LIFT
DEVELOPS ON THE 300 SURFACE. SATURATED PRESSURE DEFICITS ALSO
DRAMATICALLY DECREASE AS WELL. THE 06Z NAM CAME IN EVEN MORE
FAVORABLE THAN THE 00Z. ALL THIS PLUS SREF AND GEFS PROBABILITIES
SUPPORT HAVING SLIGHT CHANCE TO LOW CHANCE POPS IN OUR SOUTHERN
PORTION AFTER 06Z.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 401 AM MDT TUE OCT 9 2012
RELATIVELY LARGE EARLY SEASON CUTOFF LOW WILL MOVE ACROSS SOUTHEAST
UTAH AND THEN OVER THE CENTRAL ROCKIES INTO THE NEBRASKA PANHANDLE
BY SATURDAY. CYCLOGENESIS WILL INCREASE AS THIS SYSTEM MOVES OUT
ONTO THE PLAINS. INSTABILITY AXIS WILL BE POSITIONED ACROSS THE
COLORADO/KANSAS BORDER AND EXTENDING SOUTH ACROSS TEXAS AND EASTWARD
ACROSS MUCH OF THE REST OF THE STATE. MODELS DIFFER FROM YESTERDAY
IN THAT BOTH THE EC AND THE GFS TAKE THE LOW THROUGH EASTERN
NEBRASKA PANHANDLE AND INTO SOUTHERN MINNESOTA. COMBINED WITH
THIS...A 250 MB JET STREAK WILL BE IN PLACE ACROSS NEW MEXICO AND
THEN UP THROUGH WESTERN KANSAS. AT THE SURFACE...LEE TROUGH ACROSS
EASTERN COLORADO WILL QUICKLY DEEPEN AS COLD FRONT BEGINS TO MOVE
THROUGH THE REGION. CHANCES FOR PRECIPITATION STILL LOOK TO BE ON
TRACK WITH THIS SYSTEM...WITH A CHANCE THAT SOME OF THESE STORMS MAY
BE SEVERE. MUCH OF THE SEVERE ACTIVITY APPEARS TO INITIATE WELL EAST
OF THE CWA AS BETTER OVERALL PROFILE SETS UP ACROSS IOWA AND
MISSOURI. SYSTEM DOES NOT APPEAR TO USHER IN TOO MUCH COLD AIR BUT
DOES TRY TO DRY SLOT THE AREA BY SATURDAY MORNING. IF THIS REIGNS
TRUE...SECTIONS OF THE AREA MAY SEE LITTLE TO NO PRECIPITATION.
SUBSIDENCE WILL QUICKLY MOVE IN BEHIND THE DEPARTING SYSTEM AHEAD OF
ANOTHER COLD FRONT THAT WILL MOVE ACROSS THE AREA BY EARLY NEXT
WEEK. A SHORTWAVE TROUGH WILL ALSO MOVE ACROSS THE NORTHERN PLAINS
DURING THIS TIME...WITH PRECIPITATION CHANGES REMAINING WELL NORTH
OF THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 525 AM MDT TUE OCT 9 2012
COLD FRONT IS MOVING THROUGH THE AREA AT THIS TIME. WINDS WILL
RAPIDLY INCREASE THIS MORNING WITH SPEEDS OF NEAR 23 KNOTS GUSTING
TO AROUND 33 KNOTS. LATE THIS MORNING INTO EARLY THIS AFTERNOON
THESE WINDS WILL GRADUALLY DECREASE BEFORE BECOMING LIGHT. JUST
BEHIND THE FRONT MVFR CEILINGS ARE EXPECTED TO DEVELOP AND CONTINUE
INTO EARLY AFTERNOON BEFORE RISING JUST ABOVE MVFR. SKIES WILL
CLEAR LATE THIS AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...PMM
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
401 AM MDT TUE OCT 9 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 401 AM MDT TUE OCT 9 2012
FORECAST CONCERNS WILL BE WINDS TODAY AND WEDNESDAY...HOW COOL TO
MAKE TODAY...HOW MUCH TO WARM UP THE NEXT TWO DAYS...AND CHANCE OF
PRECIPITATION LATE IN THE SHORT TERM. SATELLITE CONTINUING TO SHOW AN
AMPLIFIED AND BLOCKY FLOW FROM THE PACIFIC INTO EASTERN NORTH
AMERICA. UPPER LOW NEAR HAS MOVED CLOSER TO THE COAST BUT HAS BEGUN
TO TAKE A MORE SOUTHWARD COURSE. STRONG SYSTEM DIGGING INTO THE NORTH
CENTRAL PORTION OF THE COUNTRY IS PUSHING A COLD FRONT THROUGH THE
AREA AT THIS TIME.
AT JET LEVEL...MODELS WERE CLOSE WITH THE NAM DOING A LITTLE BETTER
THAN THE REMAINING OUTPUT. AT MID LEVELS...MODELS TENDED TO HAVE THE
FEATURES/HEIGHT FIELD TOO FAR SOUTH AND WEST. OVERALL THE CANADIAN...
GFS...AND UKMET WERE DOING THE BEST. HOWEVER...THE NAM DID BETTER ON
THE NORTH CENTRAL SYSTEM. THE MODELS WERE NOT QUITE FAST ENOUGH
WITH THE FRONT. THE HRRR AND RUC WERE DOING THE BEST FOLLOWED BY THE
NAM ON THAT AND OVERALL. ON THE LOW LEVEL THERMAL FIELD THE MODELS
OVERALL WERE CLOSE. HOWEVER...THEY TENDED TO NOT HAVE THE COLD AIR
TO OUR NORTH FAR ENOUGH SOUTH AND WEST. IN THIS AREA THE CANADIAN
AND THE UKMET WERE DOING THE BEST.
TODAY/TONIGHT...AFTER SPEEDING UP THE FRONT THE MODELS HAVE NOW
SLOWED THE FRONT DOWN. LOOKS LIKE IT WILL BE THROUGH THE NORTHWEST
HALF OF THE AREA BY 12Z AND THROUGH ALL THE AREA BY 15Z OR SO.
WINDS LOOK TO STAY UNDER WIND ADVISORY CRITERIA. THE TIGHTEST
GRADIENT AND 3 HOUR PRESSURE RISES ARE DONE BY 15Z AND THEN THEY
START STEADILY DECREASING. BY THE TIME THE SUN COMES UP AND STARTS
THE HEATING...WHICH MAY BE LIMITED BY CLOUD COVER...THOSE
PARAMETERS WILL HAVE BEGUN THIS DECREASE.
THE MODELS ALSO LOOK LIKE THEY HAVE BACK OFF A LITTLE ON THE STRATUS
BEHIND IT. SOME OTHER MID AND HIGH LEVEL CLOUDS WILL MOVE THROUGH AS
WELL DUE TO THE SHORTWAVE TROUGH AND A RIGHT REAR QUADRANT OF THE
JET MOVES FROM NORTH TO SOUTH ACROSS THE AREA THIS MORNING. AT THE
VERY LEAST THIS IS GOING TO PRODUCE THICK CLOUD COVER DURING THIS
TIME. SUBSIDENCE AND CLEARING SHOULD OCCUR BEGINNING AT 18Z. MODELS
HAVE BEEN TRENDING COOLER WITH THE TEMPERATURES AND FOLLOWED THAT
TREND IN THE GRIDS.
VERY LIGHT WINDS AND LOW DEWPOINTS WITH LITTLE IF ANY CLOUD COVER
TONIGHT. THE BEST RADIATIONAL CONDITIONS OCCUR OVER THE NORTHEAST
AND EASTERN COUNTIES AND LOWERED OVERNIGHT LOWS AS A RESULT.
WEDNESDAY/WEDNESDAY NIGHT...SURFACE RIDGE MOVES OFF AS LEE TROUGH
DEVELOPS. PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS INCREASE BY
18Z WHICH SHOULD LEAD TO AT LEAST BREEZY AND POSSIBLY WINDY
CONDITIONS DEVELOPING. HIGHER CLOUDS INCREASE DURING THE AFTERNOON IN
THE WEST. MODELS BEGIN DIFFERING HERE ON THE AMOUNT OF WARMUP. WILL
HAVE A COLD START...ESPECIALLY EAST. MODELS HAVE BEEN REALLY ALL
OVER THE PLACE RECENTLY. USING THE 2 METER TEMPERATURES THAT HAVE
BEEN DOING THE BEST AND RECENT 850 MB TEMPERATURE BIASES LED TO ONLY
A SLIGHT ADJUSTMENT TO THE CURRENT FORECAST.
RIGHT REAR QUADRANT OF THE JET MOVES SLOWLY NORTH TO SOUTH ACROSS
THE AREA DURING THE NIGHT. THIS WILL INCREASE CLOUDS PLUS LOW LEVEL
WARM AIR ADVECTION INCREASES THROUGH THE NIGHT. SO WILL BE MUCH
WARMER THAN IT HAS RECENTLY.
THURSDAY/THURSDAY NIGHT...RIGHT REAR QUADRANT REMAINS OVER OR NEAR
THE NORTHERN PORTION OF THE AREA THROUGH THE DAY. UPPER RIDGE
BUILDS TO OUR WEST IN ADVANCE OF UPPER LOW IN THE DESERT SOUTHWEST.
MODELS HAVE SLOWED IN THEIR PROGRESSION OF THIS FEATURE. THIS HAS
ALLOWED A WEST TO WEST NORTHWEST FLOW TO REMAIN A LITTLE LONGER
OVER THE AREA. SO WILL PROBABLY HAVE A LITTLE MORE CLOUD COVER...
ESPECIALLY IN THE NORTH.
BUT WHAT IS MORE IMPORTANT...THIS IS ALLOWING A WEAK SHORTWAVE
TROUGH IN THE NORTH CENTRAL PORTION OF THE COUNTRY TO PUSH A
BACKDOOR COLD FRONT THROUGH THE AREA. MODELS DO SHOW THIS IN A
SIMILAR FASHION BUT DIFFER DRAMATICALLY ON HOW MUCH TO COOL OFF THE
TEMPERATURES. THERE IS A 10 TO 15 DEGREE DIFFERENCE. HEIGHTS RISE
OVER THE PREVIOUS DAY WITH SIMILAR MID LEVEL TEMPERATURES. THE NAM
NWP AND 2 METER IS BY FAR THE WARMEST WITH THE SREF AND UKMET NEXT IN
LINE. THE GFS AND ECMWF FOLLOWED BY THE CANADIAN ARE THE COOLEST.
WHAT ENDED UP DOING WAS SPLITTING THE DIFFERENCE BETWEEN THE
EXTREMES. HOWEVER...COULD SEE EITHER EXTREME OCCURRING.
AGAIN THE MODELS DIFFER ON HOW FAR SOUTH TO TAKE THE FRONT WHICH
WILL AFFECT PRECIPITATION CHANCES DURING THE NIGHT. AGAIN MODELS ARE
SPLIT NEARLY EVENLY ON THE DIFFERENT SOLUTIONS. USUALLY IN THESE
SITUATIONS THE MODEL WITH BETTER TERRAIN ENDS UP HAVING A BETTER
DEPICTION OF THE FRONT. CONSIDERING THE SYNOPTIC PATTERN BELIEVE THE
FARTHER NORTH SOLUTIONS OF WHERE THE FRONT STALLS OUT ARE THE BEST.
THIS ENDS UP BEING THE NAM...UKMET AND CANADIAN. THE FRONT STALLS
OVER SOUTHEAST COLORADO AND SOUTHWEST KANSAS EARLY AND THEN MOVES
NORTH OVERNIGHT.
EVEN THOUGH THE MODELS ARE SLOWER THEY SHOOT OUT A SHORTWAVE INTO
THE AREA AFTER 06Z. ALSO A STRONGER RIGHT REAR QUADRANT
DEVELOPS/MOVES OVER THE AREA...ESPECIALLY AFTER 06Z. ELEVATED CAPE
DEVELOPS OVER THE AREA...ALTHOUGH THEY DIFFER HOW MUCH AND HOW FAR
NORTH. THERE IS ALSO LIMITED ELEVATED CINH. STRONG ISENTROPIC LIFT
DEVELOPS ON THE 300 SURFACE. SATURATED PRESSURE DEFICITS ALSO
DRAMATICALLY DECREASE AS WELL. THE 06Z NAM CAME IN EVEN MORE
FAVORABLE THAN THE 00Z. ALL THIS PLUS SREF AND GEFS PROBABILITIES
SUPPORT HAVING SLIGHT CHANCE TO LOW CHANCE POPS IN OUR SOUTHERN
PORTION AFTER 06Z.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 401 AM MDT TUE OCT 9 2012
RELATIVELY LARGE EARLY SEASON CUTOFF LOW WILL MOVE ACROSS SOUTHEAST
UTAH AND THEN OVER THE CENTRAL ROCKIES INTO THE NEBRASKA PANHANDLE
BY SATURDAY. CYCLOGENESIS WILL INCREASE AS THIS SYSTEM MOVES OUT
ONTO THE PLAINS. INSTABILITY AXIS WILL BE POSITIONED ACROSS THE
COLORADO/KANSAS BORDER AND EXTENDING SOUTH ACROSS TEXAS AND EASTWARD
ACROSS MUCH OF THE REST OF THE STATE. MODELS DIFFER FROM YESTERDAY
IN THAT BOTH THE EC AND THE GFS TAKE THE LOW THROUGH EASTERN
NEBRASKA PANHANDLE AND INTO SOUTHERN MINNESOTA. COMBINED WITH
THIS...A 250 MB JET STREAK WILL BE IN PLACE ACROSS NEW MEXICO AND
THEN UP THROUGH WESTERN KANSAS. AT THE SURFACE...LEE TROUGH ACROSS
EASTERN COLORADO WILL QUICKLY DEEPEN AS COLD FRONT BEGINS TO MOVE
THROUGH THE REGION. CHANCES FOR PRECIPITATION STILL LOOK TO BE ON
TRACK WITH THIS SYSTEM...WITH A CHANCE THAT SOME OF THESE STORMS MAY
BE SEVERE. MUCH OF THE SEVERE ACTIVITY APPEARS TO INITIATE WELL EAST
OF THE CWA AS BETTER OVERALL PROFILE SETS UP ACROSS IOWA AND
MISSOURI. SYSTEM DOES NOT APPEAR TO USHER IN TOO MUCH COLD AIR BUT
DOES TRY TO DRY SLOT THE AREA BY SATURDAY MORNING. IF THIS REIGNS
TRUE...SECTIONS OF THE AREA MAY SEE LITTLE TO NO PRECIPITATION.
SUBSIDENCE WILL QUICKLY MOVE IN BEHIND THE DEPARTING SYSTEM AHEAD OF
ANOTHER COLD FRONT THAT WILL MOVE ACROSS THE AREA BY EARLY NEXT
WEEK. A SHORTWAVE TROUGH WILL ALSO MOVE ACROSS THE NORTHERN PLAINS
DURING THIS TIME...WITH PRECIPITATION CHANGES REMAINING WELL NORTH
OF THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1146 PM MDT MON OCT 8 2012
MVFR TO VFR CONDITIONS ARE FORECAST FOR BOTH TAF SITES. LATEST
RADAR IMAGERY SHOWS THE COLD FRONT JUST NORTH OF KMCK...ARRIVING
AROUND 7Z WITH A 9Z ARRIVAL AT KGLD. MODELS SHOW AN INCREASE IN
LOW LEVEL MOISTURE DURING THE MORNING BEHIND THE COLD FRONT. MAY
HAVE SOME LOW CLOUDS DEVELOP OVER BOTH SITES AS A RESULT. THE
SKIES SHOULD CLEAR DURING THE AFTERNOON AS DRIER AIR MOVES IN.
OTHERWISE WINDS WILL BE STRONGEST DURING THE MORNING THEN DECLINE
DURING THE AFTERNOON AS THE FRONT MOVES FURTHER SOUTH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...PMM
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1153 PM MDT MON OCT 8 2012
.UPDATE...
ISSUED AT 1039 PM MDT MON OCT 8 2012
LATEST REGIONAL RADAR IMAGERY SHOWS THE COLD FRONT ALREADY OVER
SOUTHERN NEBRASKA...WELL AHEAD OF WHERE THE MODELS HAVE THE FRONT.
BEHIND THE FRONT TEMPERATURES ARE STILL IN THE MID 40S TO MID
50S UP INTO SOUTH DAKOTA...AIDED BY THE OVERCAST SKIES BEHIND THE
FRONT WHILE COOLER AIR IS BEGINNING TO ENTER THE NORTHWEST PART
OF THE STATE.
IF THE FRONT CONTINUES AT ITS PRESENT SPEED IT WILL BE THROUGH THE
AREA BEFORE SUNRISE. WITH A QUICKER FRONTAL PASSAGE...AM THINKING
THE WINDS BEHIND THE FRONT WILL NOT HAVE TIME TO MIX
TO THE GROUND WITH THE INVERSION IN PLACE. INSTEAD OF MIXING THE
MAIN CONTRIBUTOR TO THE WIND WILL BE THE RAPID PRESSURE RISES
BEHIND THE FRONT DURING THE MORNING...WHICH MAY LEAD TO GUSTS OF
40 MPH. THE WINDS WILL DECLINE DURING THE AFTERNOON AS THE FRONT
MOVES FURTHER SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 128 PM MDT MON OCT 8 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE SCALE
TROUGH DOMINATING PATTERN ACROSS NORTH AMERICAN...WITH BROAD
LONG WAVE TROUGH IN PLACE OVER CANADA. ON TROUGH AXIS EXTENDS SOUTH
ALONG THE MISSISSIPPI RIVER VALLEY...WITH A CLOSED UPPER LOW OFF THE
CALIFORNIA COAST. W/NW FLOW IS IN PLACE OVER THE TRI STATE REGION
WITH A SHORTWAVE TROUGH UPSTREAM OVER WYOMING. AT THE SURFACE A COLD
FRONT IS CURRENTLY EXTENDING ACROSS SOUTHERN MONTANA INTO THE
NORTHERN PART OF SOUTH DAKOTA.
THIS COLD FRONT IS EXPECTED TO DROP SOUTH ACROSS THE CWA BETWEEN
09-12Z...WITH WINDS INCREASING BEHIND IT. I HAVE CONCERNS THAT WE
MAY REACH WIND ADVISORY CRITERIA ACROSS OUR SOUTHEAST BETWEEN
12-15Z...WITH ADVERTISED PRESSURE RISES BETWEEN 8-11MB AND H85 WINDS
AROUND 14Z. THE BIGGEST QUESTION WILL BE WHETHER THESE WINDS CAN MIX
DOWN BEFORE THE PRESSURE GRADIENT BEGINS TO WEAKEN OVER OUR CWA. FOR
I INCREASED WINDS TO JUST BELOW ADVISORY CRITERIA...WITH CONFIDENCE
TOO LOW AT THIS TIME. LARGE SCALE ASCENT AND BEST MOISTURE SHOULD
REMAIN WELL NORTH OF THE CWA...SO ONLY MID-HIGH CLOUDS ARE EXPECTED
TUESDAY MORNING.
ON ANOTHER NOTE...NAM/SREF CONTINUE TO ADVERTISE POSSIBLE FOG
DEVELOPMENT ACROSS THE NORTHWEST. THIS COINCIDES WITH THE AREAS
THAT RECEIVED SNOW SEVERAL DAYS AGO THAT HAS ALREADY MELTED. BOTH
MODELS HAVE SIGNIFICANTLY HIGHER TD VALUES THAN WHAT IS CURRENTLY
OCCURRING...SO CONSIDERING THIS BIAS I WILL NOT BE INCLUDING FOG IN
THE FORECAST FOR TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 131 PM MDT MON OCT 8 2012
SHORTWAVE RIDGING WILL BUILD OVER THE AREA WEDNESDAY AND THURSDAY
WITH TEMPERATURES NEAR NORMAL AND DRY CONDITIONS. A CUT OFF LOW
WILL MOVE ACROSS THE SOUTHERN AND CENTRAL ROCKIES LATE THIS WEEK.
CURRENTLY THE MODELS BRING THE SYSTEM INTO THE LOCAL AREA FRIDAY
AND SATURDAY...HOWEVER TIMING MAY BE TOO FAST GIVEN PREVIOUS
EXPERIENCE WITH CUT OFF SYSTEMS AND IT MAY NOT ARRIVE UNTIL FRIDAY
NIGHT OR SATURDAY AND DEPART SATURDAY NIGHT OR SUNDAY. THERE WILL
BE A CHANCE FOR SEVERE THUNDERSTORMS AS THE MAIN DYNAMICS ARRIVE
FOLLOWED BY A DRY SLOT AND EVENTUALLY SOME LIGHT WRAPAROUND
PRECIPITATION ON THE BACKSIDE. THERE IS NOT MUCH COLD AIR WITH THE
SYSTEM SO NO WINTRY WEATHER EXPECTED. NORTHWEST FLOW WILL BECOME
ESTABLISHED EARLY NEXT WEEK WITH A HINT OF ANOTHER SHORTWAVE
TROUGH...THOUGH MOISTURE MAY BE LIMITED WITH THAT SYSTEM.
TEMPERATURES WILL BE BELOW NORMAL FRIDAY THROUGH SUNDAY WITH THE
PRECIPITATION AND CLOUDS...THEN NEAR NORMAL EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1146 PM MDT MON OCT 8 2012
MVFR TO VFR CONDITIONS ARE FORECAST FOR BOTH TAF SITES. LATEST
RADAR IMAGERY SHOWS THE COLD FRONT JUST NORTH OF KMCK...ARRIVING
AROUND 7Z WITH A 9Z ARRIVAL AT KGLD. MODELS SHOW AN INCREASE IN
LOW LEVEL MOISTURE DURING THE MORNING BEHIND THE COLD FRONT. MAY
HAVE SOME LOW CLOUDS DEVELOP OVER BOTH SITES AS A RESULT. THE
SKIES SHOULD CLEAR DURING THE AFTERNOON AS DRIER AIR MOVES IN.
OTHERWISE WINDS WILL BE STRONGEST DURING THE MORNING THEN DECLINE
DURING THE AFTERNOON AS THE FRONT MOVES FURTHER SOUTH.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1056 PM MDT MON OCT 8 2012
.UPDATE...
ISSUED AT 1039 PM MDT MON OCT 8 2012
LATEST REGIONAL RADAR IMAGERY SHOWS THE COLD FRONT ALREADY OVER
SOUTHERN NEBRASKA...WELL AHEAD OF WHERE THE MODELS HAVE THE FRONT.
BEHIND THE FRONT TEMPERATURES ARE STILL IN THE MID 40S TO MID
50S UP INTO SOUTH DAKOTA...AIDED BY THE OVERCAST SKIES BEHIND THE
FRONT WHILE COOLER AIR IS BEGINNING TO ENTER THE NORTHWEST PART
OF THE STATE.
IF THE FRONT CONTINUES AT ITS PRESENT SPEED IT WILL BE THROUGH THE
AREA BEFORE SUNRISE. WITH A QUICKER FRONTAL PASSAGE...AM THINKING
THE WINDS BEHIND THE FRONT WILL NOT HAVE TIME TO MIX
TO THE GROUND WITH THE INVERSION IN PLACE. INSTEAD OF MIXING THE
MAIN CONTRIBUTOR TO THE WIND WILL BE THE RAPID PRESSURE RISES
BEHIND THE FRONT DURING THE MORNING...WHICH MAY LEAD TO GUSTS OF
40 MPH. THE WINDS WILL DECLINE DURING THE AFTERNOON AS THE FRONT
MOVES FURTHER SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 128 PM MDT MON OCT 8 2012
EARLY AFTERNOON WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE SCALE
TROUGH DOMINATING PATTERN ACROSS NORTH AMERICAN...WITH BROAD
LONG WAVE TROUGH IN PLACE OVER CANADA. ON TROUGH AXIS EXTENDS SOUTH
ALONG THE MISSISSIPPI RIVER VALLEY...WITH A CLOSED UPPER LOW OFF THE
CALIFORNIA COAST. W/NW FLOW IS IN PLACE OVER THE TRI STATE REGION
WITH A SHORTWAVE TROUGH UPSTREAM OVER WYOMING. AT THE SURFACE A COLD
FRONT IS CURRENTLY EXTENDING ACROSS SOUTHERN MONTANA INTO THE
NORTHERN PART OF SOUTH DAKOTA.
THIS COLD FRONT IS EXPECTED TO DROP SOUTH ACROSS THE CWA BETWEEN
09-12Z...WITH WINDS INCREASING BEHIND IT. I HAVE CONCERNS THAT WE
MAY REACH WIND ADVISORY CRITERIA ACROSS OUR SOUTHEAST BETWEEN
12-15Z...WITH ADVERTISED PRESSURE RISES BETWEEN 8-11MB AND H85 WINDS
AROUND 14Z. THE BIGGEST QUESTION WILL BE WHETHER THESE WINDS CAN MIX
DOWN BEFORE THE PRESSURE GRADIENT BEGINS TO WEAKEN OVER OUR CWA. FOR
I INCREASED WINDS TO JUST BELOW ADVISORY CRITERIA...WITH CONFIDENCE
TOO LOW AT THIS TIME. LARGE SCALE ASCENT AND BEST MOISTURE SHOULD
REMAIN WELL NORTH OF THE CWA...SO ONLY MID-HIGH CLOUDS ARE EXPECTED
TUESDAY MORNING.
ON ANOTHER NOTE...NAM/SREF CONTINUE TO ADVERTISE POSSIBLE FOG
DEVELOPMENT ACROSS THE NORTHWEST. THIS COINCIDES WITH THE AREAS
THAT RECEIVED SNOW SEVERAL DAYS AGO THAT HAS ALREADY MELTED. BOTH
MODELS HAVE SIGNIFICANTLY HIGHER TD VALUES THAN WHAT IS CURRENTLY
OCCURRING...SO CONSIDERING THIS BIAS I WILL NOT BE INCLUDING FOG IN
THE FORECAST FOR TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 131 PM MDT MON OCT 8 2012
SHORTWAVE RIDGING WILL BUILD OVER THE AREA WEDNESDAY AND THURSDAY
WITH TEMPERATURES NEAR NORMAL AND DRY CONDITIONS. A CUT OFF LOW
WILL MOVE ACROSS THE SOUTHERN AND CENTRAL ROCKIES LATE THIS WEEK.
CURRENTLY THE MODELS BRING THE SYSTEM INTO THE LOCAL AREA FRIDAY
AND SATURDAY...HOWEVER TIMING MAY BE TOO FAST GIVEN PREVIOUS
EXPERIENCE WITH CUT OFF SYSTEMS AND IT MAY NOT ARRIVE UNTIL FRIDAY
NIGHT OR SATURDAY AND DEPART SATURDAY NIGHT OR SUNDAY. THERE WILL
BE A CHANCE FOR SEVERE THUNDERSTORMS AS THE MAIN DYNAMICS ARRIVE
FOLLOWED BY A DRY SLOT AND EVENTUALLY SOME LIGHT WRAPAROUND
PRECIPITATION ON THE BACKSIDE. THERE IS NOT MUCH COLD AIR WITH THE
SYSTEM SO NO WINTRY WEATHER EXPECTED. NORTHWEST FLOW WILL BECOME
ESTABLISHED EARLY NEXT WEEK WITH A HINT OF ANOTHER SHORTWAVE
TROUGH...THOUGH MOISTURE MAY BE LIMITED WITH THAT SYSTEM.
TEMPERATURES WILL BE BELOW NORMAL FRIDAY THROUGH SUNDAY WITH THE
PRECIPITATION AND CLOUDS...THEN NEAR NORMAL EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 517 PM MDT MON OCT 8 2012
MAINLY VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE TAF PERIOD
AT BOTH MCK AND GLD. A COLD FRONT WILL MOVE THROUGH BOTH TAF SITES
AROUND 12Z TOMORROW MORNING BRINGING A FEW MID TO LOW LEVEL CLOUDS
AND STRONG NORTHERLY WINDS...GUSTING UP 30KTS AT TIMES. WINDS WILL
DIMINISH BY THE EARLY AFTERNOON TO 12KTS OR LESS AS THE FRONT EXITS
THE REGION AND HIGH PRESSURE BUILDS INTO THE AREA. THERE EXISTS THE
POSSIBILITY FOR A SHORT PERIOD OF MVFR CEILINGS WITH LOW CLOUDS
ASSOCIATED WITH THE FRONTAL PASSAGE...SO ALLUDED TO THIS BY
MENTIONING A SCATTERED DECK AROUND 1800FT AT GLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...024
AVIATION...JJM/JTL
AREA FORECAST DISCUSSION
NWS GRAY ME
946 AM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE
AREA WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT
USHERING IN COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD
OVER NEW ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM
FRONT WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /TODAY/...
10AM UPDATE... HAVE MADE ONLY MINOR ADJUSTMENTS TO TEMPERATURES
TODAY. SOME LOWER STRATUS ARE MOVING INTO THE AREA FROM THE
SOUTHWEST IN ASSOCIATION WITH A SHORTWAVE TROUGH ALOFT AND
OFFSHORE LOW PRESSURE. ONLY A SLIGHT CHANCE OF SHOWERS WITH
THIS... AS SOME ACTIVITY IS SHOWING UP ON REGIONAL RADARS ALREADY.
MUCH OF THIS MAY NOT BE REACHING THE GROUND. BEST CHANCE TO
RECEIVE PRECIPITATION WILL BE ALONG THE COAST.
UPDATE...SOME TWEAKS TO THE GOING FCST TO ACCOUNT FOR LATEST
OBSERVATIONAL TRENDS IN TEMPS AND DEW POINTS. ELY WINDS HAVE
PICKED UP ON THE COAST...AND THAT IS HELPING TO PUSH SOME OF THAT
HIGH MID LVL RH ONSHORE. BLENDED THE PREVIOUS FCST WITH THE LOCAL
WRF MODEL...AS IT HAD A GOOD HANDLE ON LOCATION AND TIMING OF
CLOUD DECK. ALSO SHARPENED THE GRADIENT OF POP FOR THIS AFTN...TO
KEEP ANY SHRA CONFINED TO THE COAST ONLY.
PREVIOUS DISCUSSION...CIRRUS SHIELD ALONG THE COAST AND INTERIOR
HAS ALLOWED TEMPS TO REMAIN IN THE MID 40S UNDERNEATH THE CANOPY.
HOWEVER...ON THE FRINGES AND ACROSS THE NRN MTNS AND VALLEYS
RADIATIONAL COOLING HAS ALLOWED READINGS TO TUMBLE INTO THE 30S
WITH A FEW UPR 20S. HERE AREAS OF GROUND/VALLEY FOG WILL BE
COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORNING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ150>154.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
713 AM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE AREA
WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT USHERING IN
COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD OVER NEW
ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM FRONT
WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SOME TWEAKS TO THE GOING FCST TO ACCOUNT FOR LATEST
OBSERVATIONAL TRENDS IN TEMPS AND DEW POINTS. ELY WINDS HAVE
PICKED UP ON THE COAST...AND THAT IS HELPING TO PUSH SOME OF THAT
HIGH MID LVL RH ONSHORE. BLENDED THE PREVIOUS FCST WITH THE LOCAL
WRF MODEL...AS IT HAD A GOOD HANDLE ON LOCATION AND TIMING OF
CLOUD DECK. ALSO SHARPENED THE GRADIENT OF POP FOR THIS AFTN...TO
KEEP ANY SHRA CONFINED TO THE COAST ONLY.
PREVIOUS DISCUSSION...CIRRUS SHIELD ALONG THE COAST AND INTERIOR
HAS ALLOWED TEMPS TO REMAIN IN THE MID 40S UNDERNEATH THE CANOPY.
HOWEVER...ON THE FRINGES AND ACROSS THE NRN MTNS AND VALLEYS
RADIATIONAL COOLING HAS ALLOWED READINGS TO TUMBLE INTO THE 30S
WITH A FEW UPR 20S. HERE AREAS OF GROUND/VALLEY FOG WILL BE
COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORNING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ150>154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
712 AM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE AREA
WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT USHERING IN
COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD OVER NEW
ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM FRONT
WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SOME TWEAKS TO THE GOING FCST TO ACCOUNT FOR LATEST
OBSERVATIONAL TRENDS. ELY WINDS HAVE PICKED UP ON THE COAST...AND
THAT IS HELPING TO PUSH SOME OF THAT HIGH MID LVL RH ONSHORE.
BLENDED THE PREVIOUS FCST WITH THE LOCAL WRF MODEL...AS IT HAD A
GOOD HANDLE ON LOCATION AND TIMING OF CLOUD DECK. ALSO SHARPENED
THE GRADIENT OF POP FOR THIS AFTN...TO KEEP ANY SHRA CONFINED TO
THE COAST ONLY.
PREVIOUS DISCUSSION...CIRRUS SHIELD ALONG THE COAST AND INTERIOR
HAS ALLOWED TEMPS TO REMAIN IN THE MID 40S UNDERNEATH THE CANOPY.
HOWEVER...ON THE FRINGES AND ACROSS THE NRN MTNS AND VALLEYS
RADIATIONAL COOLING HAS ALLOWED READINGS TO TUMBLE INTO THE 30S
WITH A FEW UPR 20S. HERE AREAS OF GROUND/VALLEY FOG WILL BE
COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORNING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR ANZ150>154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
553 AM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE AREA
WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT USHERING IN
COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD OVER NEW
ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM FRONT
WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SOME TWEAKS TO THE GOING FCST TO ACCOUNT FOR LATEST
OBSERVATIONAL TRENDS. ELY WINDS HAVE PICKED UP ON THE COAST...AND
THAT IS HELPING TO PUSH SOME OF THAT HIGH MID LVL RH ONSHORE.
BLENDED THE PREVIOUS FCST WITH THE LOCAL WRF MODEL...AS IT HAD A
GOOD HANDLE ON LOCATION AND TIMING OF CLOUD DECK. ALSO SHARPENED
THE GRADIENT OF POP FOR THIS AFTN...TO KEEP ANY SHRA CONFINED TO
THE COAST ONLY.
PREVIOUS DISCUSSION...CIRRUS SHIELD ALONG THE COAST AND INTERIOR
HAS ALLOWED TEMPS TO REMAIN IN THE MID 40S UNDERNEATH THE CANOPY.
HOWEVER...ON THE FRINGES AND ACROSS THE NRN MTNS AND VALLEYS
RADIATIONAL COOLING HAS ALLOWED READINGS TO TUMBLE INTO THE 30S
WITH A FEW UPR 20S. HERE AREAS OF GROUND/VALLEY FOG WILL BE
COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /WEDNESDAY/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORNING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 AM EDT
WEDNESDAY FOR ANZ150>154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS GRAY ME
251 AM EDT TUE OCT 9 2012
.SYNOPSIS...A WEAK WAVE OF LOW PRESSURE OFFSHORE COULD BRING A
FEW SHOWERS TO THE COAST TODAY. A COLD FRONT WILL MOVE ACROSS THE AREA
WEDNESDAY NIGHT... WITH ANOTHER STRONGER COLD FRONT USHERING IN
COLDER AIR ON FRIDAY. HIGH PRESSURE WILL THEN BUILD OVER NEW
ENGLAND BEFORE EXITING OFF THE COASTLINE SATURDAY. A WARM FRONT
WILL APPROACH FROM THE SOUTHWEST ON SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
CIRRUS SHIELD ALONG THE COAST AND INTERIOR HAS ALLOWED TEMPS TO
REMAIN IN THE MID 40S UNDERNEATH THE CANOPY. HOWEVER...ON THE
FRINGES AND ACROSS THE NRN MTNS AND VALLEYS RADIATIONAL COOLING
HAS ALLOWED READINGS TO TUMBLE INTO THE 30S WITH A FEW UPR 20S.
HERE AREAS OF GROUND/VALLEY FOG WILL BE COMMON.
CIRRUS WILL MOVE NEWD TODAY...WITH MOST LOCATIONS STARTING WITH AT
LEAST SOME FILTERED SUNSHINE. FARTHER TO THE SW...HIGH MID LVL RH
VALUES WILL LIFT TOWARDS THE REGION. SO HIGH CLOUDS WILL GRADUALLY
BE REPLACED BY LOWER AS THE DAY WEARS ON...ESPECIALLY AS WEAK LOW
PRES MOVES UP THE EAST COAST.
THIS LOW WILL SLIDE MOSTLY E OF THE CWFA...BUT SOME SHRA MAY CREEP
TOWARDS THE COAST DURING THE DAY. HAVE USED SOME ELEMENTS OF THE
SREF POP...BUT LIKED THE IDEA OF THE LAST FEW HRRR RUNS OF KEEPING
MOST OF THE PCPN OFFSHORE. GENERAL THEME WAS TO BACK OFF POP SOME
FOR TODAY.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
TNGT LOW PRES PULLS NEWD THRU THE GULF OF MAINE...BUT WILL HAVE TO
WATCH AND SEE HOW FAR INLAND STRATUS TRIES TO WORK. MODEL GUIDANCE
IS PRETTY AGGRESSIVE WITH IT...BUT THERE ARE SOME SIGNS IT COULD
HOLD OFF UNTIL WED. FOR NOW HAVE TRENDED BACK SKY COVER FOR THE
FAR N...WHICH WILL DROP MIN TEMPS A COUPLE DEG WITH SKIES A
LITTLE MORE CLOUD FREE.
ON WED STRONG S/WV TROF...NOW EVIDENT DIVING THRU THE
DAKOTAS...WILL INDUCE BROADLY SW FLOW ALOFT OVER THE AREA. AT THE
SFC...WINDS BECOME ONSHORE...AND THIS SHOULD HELP PULL STRATUS
FARTHER INLAND. WILL HAVE TO WATCH AND SEE IF ANY OF THIS CAN
PRODUCE PCPN AHEAD OF THE APPROACHING COLD FNT IF THE CLOUD DEPTHS
CAN INCREASE ENOUGH. N OF THE WARM FNT...THE POTENTIAL IS THERE
FOR A DREARY DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
SOME OF THE COLDEST AIR OF THE SEASON WILL USHER INTO THE REGION
WEDNESDAY NIGHT. THE CAN GEM FORMS A WEAK SURFACE WAVE ALONG THE
FRONT. NEVERTHELESS...THE SYSTEM WILL BE RELATIVELY PROGRESSIVE
AND ANY PCPN WILL BE LIGHT.
AS THE UPPER LEVEL TROUGH CROSSES THE REGION BY EARLY THURSDAY
MORING...EXPECT WINDS TO BECOME GUSTY FROM THE WNW. DOWNSLOPING
WILL ALLOW FOR THE MOST SUNSHINE TO BE FOCUSED ALONG THE
COASTLINE.
ANOTHER FRONT WILL CROSS THE REGION EARLY FRIDAY MORNING. THIS
WILL ALLOW ANOTHER SIGNIFICANT SHOT OF COLD AIR TO ENTER THE
REGION. A STRONG HIGH PRESSURE SYSTEM WILL THEN BUILD EAST AND
WILL CREST OF NEW ENGLAND ON SATURDAY BRINGING VERY CHILLY TEMPS.
THEREAFTER...TEMPS WILL MODERATE AS THE HIGH SLIPS OFFSHORE AND A
SW FLOW DEVELOPS OVER THE REGION.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...LOCAL IFR/LIFR CIGS/VSBYS THIS MORNING IN VALLEY FOG.
VFR CONDS EXPECTED TO PREVAIL TODAY. LOW CHC AT -SHRA ALONG
COAST...WITH MVFR CIGS PSBL. BETTER CHC FOR CIGS TO LOWER WED...AS
ONSHORE FLOW DEVELOPS AHEAD OF NEXT COLD FNT.
LONG TERM...COULD SEE MVFR OR IFR CONDITIONS ON WEDNESDAY IN
ADVANCE OF A COLD FRONT. RETURN TO VFR THURSDAY. MVFR POSSIBLE
AGAIN ON FRIDAY AS ANOTHER FRONT PUSHES INTO THE AREA.
&&
.MARINE...
SHORT TERM...LOW PRES WILL CROSS THE GULF OF MAINE TNGT. AS
APPROACHES WINDS AND SEAS WILL INCREASE ABV SCA THRESHOLDS TODAY.
SCA IN EFFECT THRU EARLY WED MORNING.
LONG TERM...WINDS BEHIND A COLD FRONT LATE WEDNESDAY NIGHT AND ON
THURSDAY MAY GUST TO 25 OR 30 KT. HIGH PRESSURE CRESTS OVER THE
WATERS THURSDAY AND SOUTHWEST FLOW RETURNS BRIEFLY BEFORE ANOTHER
COLD FRONT PUSHES THROUGH ON FRIDAY. WINDS WILL BE NEAR 25 KT SO
SMALL CRAFT ADVISORIES MAY BE NEEDED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 AM EDT
WEDNESDAY FOR ANZ150>154.
&&
$$
LEGRO/JC
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1016 PM EDT WED OCT 10 2012
.SYNOPSIS...
IN THE WAKE OF A COLD FRONT...HIGH PRESSURE WILL APPROACH FROM
THE SOUTHWEST OVERNIGHT. THIS WILL ALLOW CLEARING SKIES AND
TEMPERATURES DROPPING BELOW FREEZING ACROSS MUCH OF THE AREA. THE
NEXT COLD FRONT WILL CROSS THE AREA THURSDAY NIGHT INTO FRIDAY
MORNING WITH HIGH PRESSURE THEN BUILDING IN FOR THE EARLY PART OF
THE WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
03Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO REDUCE
POPS ACROSS THE NORTH. OTHERWISE...NO CHANGE AND THE FOLLOWING
DISCUSSION REMAINS THE SAME.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A BROAD 500MB TROUGH
CENTERED ACROSS THE EASTERN GREAT LAKES WITH THE UPPER OHIO VALLEY
IN A WEAK CYCLONIC TO NEAR ZONAL FLOW AT THE BASE OF THIS FEATURE.
AT THE SURFACE...A COLD FRONT HAS PUSHED WELL EAST OF THE AREA
AND COLD AIR ADVECTION IS OCCURRING WITH A WNWRLY FLOW IN THE
FRONTS WAKE. MEANWHILE...A SURFACE HIGH IS CENTERED IN WESTERN KY.
THE PASSING TROUGH ALONG WITH WEAK COLD AIR ADVECTION ACROSS LAKE
ERIE ARE ALLOWING FOR A FEW REMAINING SHOWERS ACROSS THE I-80
CORRIDOR.
TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS KENTUCKY AND BECOME
CENTERED OVER WEST VIRGINIA BY 12Z THURSDAY. WEAK CAA ALONG WITH A
NWRLY 850MB FLOW WILL ALLOW FOR A FEW MORE SHOWERS ACROSS THE I-80
CORRIDOR THROUGH 06Z. THE 850MB FLOW WILL BACK TO MORE ZONAL AFTER
06Z...BRINGING ANY LINGERING SHOWERS TO AN END. WITH A DEEP LAYER OF
DRY AIR AND SUBSIDENCE ALOFT FROM HIGH PRESSURE BUILDING IN...SKIES
WILL BE CLEAR OVERNIGHT EVERYWHERE ASIDE FROM THE I-80 CORRIDOR. A
STRONG RADIATIONAL COOLING NIGHT IS SETTING UP AS WINDS DROP TO
NEAR CALM OVERNIGHT WITH THE HIGH BUILDING IN AND TDS IN THE UPPER
20S IN OHIO ADVECTING INTO THE AREA. WITH THIS IN MIND...FORECAST IS
CLOSER TO THE COOLER MAV GUIDANCE WITH LOWS IN THE UPPER 20S TO
LOWER 30S. THUS...A WIDESPREAD FREEZE IS EXPECTED AND A FREEZE
WARNING REMAINS IN EFFECT FOR PORTIONS OF THE AREA THAT HAVE NOT
HAD A WIDESPREAD FREEZE YET THIS FALL.
THURSDAY...A ZONAL MID-LEVEL FLOW WILL REMAIN IN PLACE WITH THE
SURFACE HIGH SHIFTING EASTWARD INTO THE DELMARVA PENINSULA. THUS...THE
LOW-LEVEL FLOW WILL SHIFT TO MORE SOUTHWESTERLY THROUGH THE DAY
AND WEAK WAA ADVECTION WILL ENSUE. WITH THE DEEP LAYER OF DRY AIR
REMAINING IN PLACE...ABUNDANT SUNSHINE WILL ALSO AID IN TEMPS
RECOVERING THROUGH THE DAY. WITH THIS IN MIND...HIGHS ARE A MAV/MET
BLEND...RANGING FROM THE MID 50S ACROSS THE EASTERN RIDGES AND I-80
CORRIDOR TO NEAR 60 IN PORTIONS OF EASTERN OHIO.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
MODELS REMAIN IN GOOD OVERALL AGREEMENT...ALBEIT WITH QUICKER
TIMING THAN PREVIOUS SOLNS...IN DEPICTIONS OF CONTINUED
PROGRESSIVE FLOW FEATURING THE APPROACH AND PASSAGE OF ANOTHER
COLD FRONT FOR THURSDAY NIGHT INTO FRIDAY MORNING...BUT WITH ONLY
SLIGHT SHRA CHCS GIVEN THE LACK OF MSTR.
BUILDING HIGH PRES IS FORECAST TO QUICKLY END ANY PCPN BY MIDDAY
FRIDAY...AND ANOTHER COLD NGT IS ANTICIPATED BEFORE WARM ADVCTN
RESUMES IN ADVN OF A STRNGER SYSTEM PROJECTED ACRS THE MIDWEST.
THE SHRTWV RIDGE IN THE AMPLIFIED FLOW SPPRTS A WARMER...AND
STILL DRY SATURDAY...ALTHOUGH SLIGHT CHC POPS WERE INCLUDED OVR
NRN COUNTIES AS MDLS...WITH GFS PROJECTING A MORE SRN EXTENT...SPAWN
PCPN ALNG THE ADVNG LOWS WARM FRONT.
SHORT TERM TEMPS WERE FORECAST USING TWEAKED SREF MEANS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
STRATOCUMULUS ARE FADING QUICKLY POST-FRONTAL AS SUBSTANTIALLY
DRIER BOUNDARY LAYER AIR IS USHERED INTO THE REGION. WHILE THE LOW
LEVELS REMAIN FAIRLY UNSTABLE...A LACK OF MOISTURE SHOULD PRECLUDE
MUCH CLOUD FORMATION OVER THE AREA FOR THE NEXT 24 HOURS...WITH
ONE GIANT EXCEPTION. DOWN WIND OF LAKE ERIE...LAKE-INDUCED
STRATOCUMULUS WILL CONTINUE TO BLOSSOM DUE TO EXTREME LAKE EFFECT
INSTABILITY. LAKE TO 850 MB DELTA T VALUES ARE RUNNING UPWARDS OF
23C THIS EVENING...AND WHILE THESE VALUES WILL BE NARROWING AS THE
850 MB TEMPERATURES EDGE UP ON THURSDAY...LAKE EFFECT SHOWERS AND
CLOUDS DOWNWIND OF THE LAKE WILL BE COMMON. HOWEVER...CURRENT
BOUNDARY LAYER FLOW IS ONLY SLIGHTLY NORTH OF DUE WESTERLY...AND
THIS FLOW WILL BACK TOWARD WSW BY THURSDAY MORNING. AS
SUCH...SHOWERS AND CLOUDS WILL BE COMMON AROUND KFKL...BUT EDGE
NORTHWARD BY MORNING. NO OTHER SITES SHOULD BE IMPACTED BY
SHOWERS.
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL BE PREVALENT INTO SATURDAY...EVEN DESPITE A
WEAK FRONTAL PASSAGE ON FRIDAY THAT WILL HAVE LITTLE IMPACT ON THE
TERMINALS. THE BETTER CHANCE OF SHOWERS AND RESTRICTIONS WILL BE
ON SUNDAY WHEN THE NEXT COLD FRONT CROSSES THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING FROM 3 AM TO 9 AM EDT THURSDAY FOR PAZ016-022-
023-031-073-075.
WV...FREEZE WARNING FROM 3 AM TO 9 AM EDT THURSDAY FOR WVZ004-012-
021-022.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...FRIES
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
811 PM EDT WED OCT 10 2012
.SYNOPSIS...
IN THE WAKE A OF A COLD FRONT...HIGH PRESSURE WILL APPROACH FROM THE
SOUTHWEST OVERNIGHT. THIS WILL ALLOW FOR SHOWERS NORTH OF
PITTSBURGH TO DIMINISH WITH CLEARING SKIES AND TEMPERATURES
DROPPING BELOW FREEZING FOR LOWS ACROSS MUCH OF THE AREA. THE NEXT
COLD FRONT WILL CROSS THE AREA THURSDAY NIGHT INTO FRIDAY MORNING
WITH HIGH PRESSURE THEN BUILDING IN FOR THE EARLY PART OF THE
WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
00Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED IN ORDER
TO DECREASE CLOUD COVERAGE EARLIER AND TO ADD WIDESPREAD FROST
WORDING TO LOCATIONS IN THE FREEZE WARNING.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A BROAD 500MB TROUGH
CENTERED ACROSS THE EASTERN GREAT LAKES WITH THE UPPER OHIO VALLEY
IN A WEAK CYCLONIC TO NEAR ZONAL FLOW AT THE BASE OF THIS FEATURE.
AT THE SURFACE...A COLD FRONT HAS PUSHED WELL EAST OF THE AREA
AND COLD AIR ADVECTION IS OCCURRING WITH A WNWRLY FLOW IN THE
FRONTS WAKE. MEANWHILE...A SURFACE HIGH IS CENTERED IN WESTERN KY.
DIURNALLY DRIVEN CU HAS MOSTLY DIMINISHED THIS EVENING...LEAVING
LINGERING CLOUD COVERAGE MOSTLY NORTH OF PITTSBURGH. THE PASSING
TROUGH ALONG WITH WEAK COLD AIR ADVECTION ACROSS LAKE ERIE ARE
ALLOWING FOR A FEW REMAINING SHOWERS ACROSS THE I-80 CORRIDOR THIS
EVENING.
TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS KENTUCKY AND BECOME
CENTERED OVER WEST VIRGINIA BY 12Z THURSDAY. WEAK CAA ALONG WITH A
NWRLY 850MB FLOW WILL ALLOW FOR A FEW MORE SHOWERS ACROSS THE I-80
CORRIDOR THROUGH 06Z. THE 850MB FLOW WILL BACK TO MORE ZONAL AFTER
06Z...BRINGING ANY LINGERING SHOWERS TO AN END. WITH A DEEP LAYER OF
DRY AIR AND SUBSIDENCE ALOFT FROM HIGH PRESSURE BUILDING IN...SKIES
WILL BE CLEAR OVERNIGHT EVERYWHERE ASIDE FROM THE I-80 CORRIDOR. A
STRONG RADIATIONAL COOLING NIGHT IS SETTING UP AS WINDS DROP TO
NEAR CALM OVERNIGHT WITH THE HIGH BUILDING IN AND TDS IN THE UPPER
20S IN OHIO ADVECTING INTO THE AREA. WITH THIS IN MIND...FORECAST IS
CLOSER TO THE COOLER MAV GUIDANCE WITH LOWS IN THE UPPER 20S TO
LOWER 30S. THUS...A WIDESPREAD FREEZE IS EXPECTED AND A FREEZE
WARNING REMAINS IN EFFECT FOR PORTIONS OF THE AREA THAT HAVE NOT
HAD A WIDESPREAD FREEZE YET THIS FALL.
THURSDAY...A ZONAL MID-LEVEL FLOW WILL REMAIN IN PLACE WITH THE
SURFACE HIGH SHIFTING EASTWARD INTO THE DELMARVA PENINSULA. THUS...THE
LOW-LEVEL FLOW WILL SHIFT TO MORE SOUTHWESTERLY THROUGH THE DAY
AND WEAK WAA ADVECTION WILL ENSUE. WITH THE DEEP LAYER OF DRY AIR
REMAINING IN PLACE...ABUNDANT SUNSHINE WILL ALSO AID IN TEMPS
RECOVERING THROUGH THE DAY. WITH THIS IN MIND...HIGHS ARE A MAV/MET
BLEND...RANGING FROM THE MID 50S ACROSS THE EASTERN RIDGES AND I-80
CORRIDOR TO NEAR 60 IN PORTIONS OF EASTERN OHIO.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
MODELS REMAIN IN GOOD OVERALL AGREEMENT...ALBEIT WITH QUICKER
TIMING THAN PREVIOUS SOLNS...IN DEPICTIONS OF CONTINUED
PROGRESSIVE FLOW FEATURING THE APPROACH AND PASSAGE OF ANOTHER
COLD FRONT FOR THURSDAY NIGHT INTO FRIDAY MORNING...BUT WITH ONLY
SLIGHT SHRA CHCS GIVEN THE LACK OF MSTR.
BUILDING HIGH PRES IS FORECAST TO QUICKLY END ANY PCPN BY MIDDAY
FRIDAY...AND ANOTHER COLD NGT IS ANTICIPATED BEFORE WARM ADVCTN
RESUMES IN ADVN OF A STRNGER SYSTEM PROJECTED ACRS THE MIDWEST.
THE SHRTWV RIDGE IN THE AMPLIFIED FLOW SPPRTS A WARMER...AND
STILL DRY SATURDAY...ALTHOUGH SLIGHT CHC POPS WERE INCLUDED OVR
NRN COUNTIES AS MDLS...WITH GFS PROJECTING A MORE SRN EXTENT...SPAWN
PCPN ALNG THE ADVNG LOWS WARM FRONT.
SHORT TERM TEMPS WERE FORECAST USING TWEAKED SREF MEANS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
STRATOCUMULUS ARE FADING QUICKLY POST-FRONTAL AS SUBSTANTIALLY
DRIER BOUNDARY LAYER AIR IS USHERED INTO THE REGION. WHILE THE LOW
LEVELS REMAIN FAIRLY UNSTABLE...A LACK OF MOISTURE SHOULD PRECLUDE
MUCH CLOUD FORMATION OVER THE AREA FOR THE NEXT 24 HOURS...WITH
ONE GIANT EXCEPTION. DOWN WIND OF LAKE ERIE...LAKE-INDUCED
STRATOCUMULUS WILL CONTINUE TO BLOSSOM DUE TO EXTREME LAKE EFFECT
INSTABILITY. LAKE TO 850 MB DELTA T VALUES ARE RUNNING UPWARDS OF
23C THIS EVENING...AND WHILE THESE VALUES WILL BE NARROWING AS THE
850 MB TEMPERATURES EDGE UP ON THURSDAY...LAKE EFFECT SHOWERS AND
CLOUDS DOWNWIND OF THE LAKE WILL BE COMMON. HOWEVER...CURRENT
BOUNDARY LAYER FLOW IS ONLY SLIGHTLY NORTH OF DUE WESTERLY...AND
THIS FLOW WILL BACK TOWARD WSW BY THURSDAY MORNING. AS
SUCH...SHOWERS AND CLOUDS WILL BE COMMON AROUND KFKL...BUT EDGE
NORTHWARD BY MORNING. NO OTHER SITES SHOULD BE IMPACTED BY
SHOWERS.
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL BE PREVALENT INTO SATURDAY...EVEN DESPITE A
WEAK FRONTAL PASSAGE ON FRIDAY THAT WILL HAVE LITTLE IMPACT ON THE
TERMINALS. THE BETTER CHANCE OF SHOWERS AND RESTRICTIONS WILL BE
ON SUNDAY WHEN THE NEXT COLD FRONT CROSSES THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING FROM 3 AM TO 9 AM EDT THURSDAY FOR PAZ016-022-
023-031-073-075.
WV...FREEZE WARNING FROM 3 AM TO 9 AM EDT THURSDAY FOR WVZ004-012-
021-022.
&&
$$
SYNOPSIS...WOODRUM
NEAR TERM...WOODRUM
AVIATION...FRIES
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
705 PM EDT WED OCT 10 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF OVER
CNTRL NAMERICA. NEXT SHORTWAVE DROPPING INTO THE TROF IS CURRENTLY
HEADING SE THRU SASKATCHEWAN TOWARD SRN MANITOBA. THIS WAVE WILL BE
THE MAIN FCST ISSUE IN THE SHORT TERM. OTHERWISE...ALTHOUGH 850MB
THERMAL TROF (TEMPS OF -6 TO -8C) IS STILL CROSSING THE AREA...LAKE
EFFECT PCPN HAS BEEN GRADUALLY WINDING DOWN FROM W TO E DUE TO
SOMEWHAT DRIER AIR ADVECTING INTO THE AREA AND FLOW BECOMING MORE
ANTICYCLONIC. MORE IMPORTANT NEGATIVE FACTOR IS PROBABLY DAYTIME
HEATING DISRUPTING LAKE EFFECT PROCESSES.
LINGERING LAKE EFFECT PCPN WILL CONTINUE TO DIMINISH AND SHIFT MORE
OFFSHORE AS WINDS BACK WITH SFC HIGH PRES RIDGE PASSING. LAST OF THE
PCPN SHOULD EXIT NRN LUCE COUNTY AROUND 06Z. ATTENTION THEN TURNS TO
APPROACHING SHORTWAVE. THERE ISN`T MUCH DIFFERENCE IN MODELS...BUT
WILL FAVOR THE REGIONAL GEM WHICH HAS BEEN VERY CONSISTENT SHOWING
MORE PCPN WITH THIS SYSTEM. FAIRLY ROBUST DEEP LAYER FORCING PER
QVECTORS ALONG WITH DECENT ISENTROPIC ASCENT (285-290K SFCS)
SUGGESTS PCPN IS A GOOD BET...ESPECIALLY ACROSS THE N AND E...CLOSER
TO SHORTWAVE TRACK. PCPN SHOULD SPREAD INTO THE W LATE EVENING AND
REACH THE E OVERNIGHT. 1000-850MB THICKNESSES IN THE 1302-1310M
RANGE SUGGEST A MIX OF RAIN/SNOW WILL OCCUR. HIGH TERRAIN SHOULD BE
PREDOMINANTLY SNOW...TRANSITIONING TO MAINLY RAIN NEAR THE GREAT
LAKES. WITH 0.1 TO 0.3 INCHES OF PCPN...MAY SEE A SLUSHY INCH OR TWO
OF SNOW ACCUMULATION IN THE HIGH TERRAIN. WINDS MAY BACK JUST ENOUGH
FOR SOME LAKE ENHANCEMENT OFF LAKE MICHIGAN INTO THE FAR ERN FCST
AREA...SO PCPN AMOUNTS MAY BE HIGHER THERE. WITH LOW-LEVELS SLIGHTLY
WARMER...LAKE ENHANCED PCPN OVER THE E SHOULD BE MOSTLY IN THE FORM
OF RAIN. TEMPS WILL HAVE A BRIEF OPPORTUNITY TO FALL THIS EVENING
(SHOULD FALL BLO FREEZING IN MANY AREAS)...BUT THICKENING CLOUDS
WILL RESULT IN TEMPS RISING A LITTLE AFTER EARLY LOWS.
THERE MAY BE A BRIEF PERIOD OF NW FLOW LAKE ENHANCEMENT THU MORNING
BEFORE FORCING EXITS AND STRONG DEEP LAYER QVECTOR DIVERGENCE AND
MID LEVEL DRYING ARRIVE. THAT WILL HELP MORE WIDESPREAD PCPN LINGER
A BIT LONGER IN THE AREAS AFFECTED BY NW FLOW OFF LAKE SUPERIOR. CAA
DROPS 850MB TEMPS TO -5 TO -7C DURING THE DAY...WHICH WILL SUPPORT
SOME LAKE EFFECT PCPN. GIVEN EARLY SEASON/DIURNAL HEATING...IT WILL
BE MORE OF A HYBRID TYPE PCPN PATTERN WITH NOT SO MUCH BANDING OFF
THE LAKE...BUT ISOLD/SCT SHOWERS EXTENDING WELL INLAND.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
THURSDAY NIGHT...THE SHORTWAVE TROUGH WILL EXIT THE NRN GREAT LAKES
WITH STRONG STRONG 700-300 MB QVECTOR CONV IN ITS WAKE. AS SFC HIGH
PRES BUILDS FROM THE NRN PLAINS INTO THE UPPER MS VALLEY NW FLOW WILL
CONTINUE ACROSS LAKE SUPERIOR WITH 850 MB TEMPS INTO THE -7C TO -8C
RANGE. WITH WATER TEMPS FROM 7C TO 12C...THERE WILL BE MORE THAN
ENOUGH INSTABILITY TO SUSTAIN LAKE EFFECT PCPN. EVEN THROUGH OVERALL
WINDS WILL BE NORTHWEST...EXPECT THEAT LAKE INDUCED TROUGHING WILL
HELP TO FOCUS LOW LEVEL CONV INTO AREAS NEAR P53 AND GRAND MARAIS.
ALTHOUGH THE LONG FETCH ACROSS THE LAKE WILL KEEP TEMPS RELATIVELY
WARM OVER THE EAST...EXPECT MAINLY SNOW WITH A COATING TO HALF AN
INCH OF ACCUMULATION IN SOME LOCATIONS. OVER THE WEST...THE PCPN WILL
TAPER OFF SOONER AS THE RIDGE AND BUILDS TOWARD THE AREA WITH LIGHT
ACYC FLOW.
FRI...ANY LINGERING LAKE EFFECT PCPN INTO THE NORTHEAST CWA WILL
TAPER OFF QUICKLY IN THE MORNING AS WINDS BACK WITH THE RIDGE
BUILDING INTO THE AREA. SUNSHINE AND DEVELOPING WAA WITH SW FLOW
SHOULD HELP PUSH TEMPS INTO THE MID AND UPPER 40S...PER FCST
SOUNDINGS.
FRI NIGHT AND SAT...MODELS WERE IN GOOD AGREEMENT WITH THE OVERALL
PATTERN RESULTING IN STRONG WAA AND MOISTURE ADVECTION INTO THE
UPPER GREAT LAKES AS A STRONG SHRTWV MOVES THROUGH THE CNTRL PLAINS.
300K-310K ISENTROPIC LIFT SUPPORTED BY UPPER LEVEL DIV WITH THE
RIGHT EXIT REGION OF THE 250-300 JET OVER NRN ONTARIO WILL SUPPORT
WIDESPREAD RAIN FROM WI SPREADING INTO UPPER MI. THE NAM/SREF WAS
PREFERRED IN WITH A LATER ONSET OF PCPN AND KEEPING THE GREATER QPF
A BIT FARTHER SOUTH...CLOSER TO THE 850 MB WARM FRONT AND GREATER
ELEVATED CAPE.
SAT NIGHT INTO SUN...THE GFS...12Z GEFS AND GEM REMAINED A BIT
FARTHER NORTH WITH THE TRACK OF THE MID LEVEL SHORTWAVE AND SFC LOW
COMPARED TO THE ECMWF. SO...THERE IS GREATER UNCERTAINTY WITH THE
POSITION AND POTENTIAL FOR HEAVY PCPN ASSOCIATED WITH THE STRONG
FGEN/DEF AS THE 700 MB LOW MOVES THROUGH. WITH EITHER SCENARIO...A
COLD WIND DRIVEN RAIN MAY LINGER INTO SUNDAY WITH WRAP-AROUND PCPN
AND SOME LAKE ENHANCEMENT OFF OF LAKE SUPERIOR AS 850 MB TEMPS DROP
TO AROUND 0C.
MON-WED...MODELS WERE SIMILAR WITH A PROGRESSIVE PATTERN EARLY NEXT
WEEK BUT SHOW EXPECTED DIFFERENCES WITH DETAILS. A WAA PATTERN WITH
THE POTENTIAL FOR MORE RAIN...ESPECIALLY FROM TUE NIGHT INTO
WED...PER MDLS CONSENSUS. TEMPS ARE EXPECTED CLIMB BACK VALUES AOA
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 705 PM EDT WED OCT 10 2012
VFR CONDITIONS SHOULD BE THE RULE AT KIWD/KCMX/KSAW THIS EVENING. A
DISTURBANCE WILL QUICKLY MOVE INTO THE AREA TONIGHT. EXPECT A PERIOD
OF MVFR CONDITIONS AS -SN/-RA SPREAD ACROSS THE AREA. PCPN SHOULD BE
MAINLY SN AT KCMX/KSAW. PCPN WILL DIMINISH/END LATE TONIGHT/THU
MORNING...BUT MVFR CIGS MAY LINGER THRU THE MORNING AT KCMX/KSAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EDT WED OCT 10 2012
ATTENTION OVER THE NEXT 24HRS IS ON LOW PRES WHICH WILL BE MOVING
ACROSS OR JUST N OF LAKE SUPERIOR LATE TONIGHT AND THU MORNING.
STRONGEST WINDS THRU EARLY THIS EVENING WILL BE OVER ERN LAKE
SUPERIOR WHERE NW WINDS WILL BE GUSTING TO 30KT WITH A FEW GUSTS TO
GALE FORCE. WINDS WILL BRIEFLY BE IN THE 15-25KT RANGE FOR A TIME
TONIGHT BEFORE INCREASING AGAIN LATE AS THE LOW ARRIVES IN THE UPPER
LAKES. SW WINDS MAY GUST TO NEAR 30KT LATE TONIGHT. OF MORE CONCERN
WILL BE THE NW WINDS DEVELOPING THU AS THE LOW SHIFTS E OF THE LAKE.
AIDED BY INCREASINGLY COLDER AIR AND PRES RISES APPROACHING FROM THE
NW...A PERIOD OF NW GALES IS A POSSIBILITY OVER THE E HALF OF LAKE
SUPERIOR. MAY NEED TO HOIST A GALE WARNING IF NEW GUIDANCE ARRIVING
THIS EVENING MORE SOLIDLY SUPPORTS GALES.
A MODERATELY STRONG LOW PRESSURE SYSTEM IS EXPECTED TO TRACK THROUGH
THE WESTERN GREAT LAKES. SOUTH WINDS OF 15 TO 25 KNOTS ARE EXPECTED
AHEAD OF THE SYSTEM SATURDAY WHILE NORTHERLY 15 TO 25 KNOT WINDS ARE
WILL DEVELOP AS THE LOW PULLS AWAY SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
427 PM EDT TUE OCT 9 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 424 PM EDT TUE OCT 9 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER CNTRL
NAMERICA. EMBEDDED IN THE TROF IS A SHORTWAVE EXTENDING FROM NRN
ONTARIO THRU NW WI TO SRN MN. AREA OF DEEP LAYER FORCING PER
QVECTORS AND STRENGTHENING LOW-MID LEVEL FRONTOGENESIS IN REPONSE TO
SHORTWAVE HAS HELPED TO DEVELOP AREA OF -RA ACROSS SE MN ACROSS WI
AND INTO MUCH OF UPPER MI TODAY.
FCST FOCUS IN THE SHORT TERM WILL SHIFT TO A DEVELOPING LAKE EFFECT
REGIME AS 850MB TEMPS FALL TOWARD -8C UNDER DEEP CYCLONIC FLOW. AS
DEEP LAYER FORCING SHIFTS E TONIGHT...AREA OF PCPN CURRENTLY
AFFECTING ALL BUT THE FAR WRN FCST AREA SHOULD END BY MID EVENING.
LAKE EFFECT PCPN WILL THEN DEVELOP/INCREASE FROM W TO E TONIGHT THRU
WED MORNING AS 850MB TEMPS FALL TO ABOUT -5C E TO -8C W BY 12Z.
UPSTREAM KINL SOUNDING AT 12Z TODAY SHOWED 850MB TEMP OF -3C WITH
DEEP MOISTURE THRU 600MB. WRN LAKE SUPERIOR BUOY SHOWS A WATER TEMP
OF 7C. FOR LAKE EFFECT PURPOSES...8C IS PROBABLY A GOOD OVERALL
ESTIMATE FOR WRN LAKE SUPERIOR SINCE THERE IS LIKELY SOME WARMER
WATER TOWARD SHORE. GIVEN THE UPSTREAM DEEP MOISTURE...THERE SHOULD
BE A PERIOD WHERE DEEP MOISTURE COINCIDES WITH SUFFICIENT OVERWATER
INSTABILITY FOR DEVELOPMENT OF DECENT COVERAGE OF LAKE EFFECT PCPN
TONIGHT. WITH WINDS VEERING NW...BEST LOW-LEVEL CONVERGENCE OVER THE
W SHOULD SET UP INTO GOGEBIC/ONTONAGON COUNTIES DUE TO LAND BREEZE
WIND COMPONENT OFF NW WI. TIME SECTIONS SHOW DENDRITIC SNOW GROWTH
TEMPS DIPPING INTO THE TOP OF CONVECTIVE/MOIST LAYER...SO WOULDN`T
BE SURPRISED TO SEE AN INCH OR TWO OF SNOW ACCUMULATION IN THE HIGH
TERRAIN...PERHAPS ISOLATED 3 INCH AMOUNTS. PCPN WILL BE MORE OF A
RAIN/GRAUPEL MIX DOWN TOWARD THE LAKE. OVER THE E...MARINE
MODIFICATION OF LOW LEVEL TEMPS WILL BE MORE PRONOUNCED DUE TO
LONGER FETCH OVER WARMER WATERS (ERN LAKE SUPERIOR BUOY SHOWS WATER
TEMP OF 10C AND IT IS LIKELY WARMER TOWARD SHORE). SO PCPN WILL BE
MORE RAIN OR RAIN/GRAUPEL RATHER THAN SNOW. MAY SEE SOME MINOR
ACCUMULATIONS.
FCST AREA IS SITUATED UNDER 850MB THERMAL TROF THRU THE DAY WED...
SO LAKE EFFECT PCPN WILL CONTINUE. HOWEVER...DEEPER MOISTURE PULLS
OUT FROM W TO E...AND FCST SOUNDINGS SHOW MORE OF A WELL-MIXED
BOUNDARY LAYER DEVELOPING AS DRIER AIR MAKES INROADS AT LOW LEVELS
AS WELL. DAYTIME HEATING WILL ALSO INCREASINGLY WORK TO DISRUPT LAKE
EFFECT PROCESSES. IN THE END...THIS WILL SPELL AN END TO LAKE EFFECT
PCPN OVER THE W IN THE AFTN AND A DIMINISHING TREND OVER THE E
DURING THE DAY. MAY SEE MINOR ADDITIONAL SNOW ACCUMULATIONS UP TO AN
INCH DURING THE MORNING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 424 PM EDT TUE OCT 9 2012
HIGH PRESSURE RIDGE WILL BE MOVING ACROSS UPPER MICHIGAN ON
WEDNESDAY EVENING. THERE WILL BE LINGERING LAKE EFFECT PCPN OVER THE
EAST IN THE EVENING BEFORE WINDS BACK TO THE WEST AND SHIFT IT
TOWARDS ONTARIO. MEANWHILE TO THE WEST...A SHORTWAVE THAT IS
CURRENTLY JUST EAST OF ALASKA WILL BE DROPPING THROUGH THE NORTHWEST
FLOW AND INTO LAKE SUPERIOR EARLY THURSDAY MORNING. QUESTION FOR THE
FORECAST IS HOW FAR S THE SHORTWAVE WILL DIG. GEM/GFS ON THE
SOUTHERN TRACK...WITH THE NAM/ECMWF ON THE NORTH. COULD END UP
MAKING A HUGE DIFFERENCE IN THE FORECAST PCPN AMNTS AND THUS SNOW
POTENTIAL. BEST FORCING...VERY STRONG H850-700 WAA ASSOCIATED WITH
THIS WAVE AND IS CO-LOCATED WITH THE BEST MOISTURE OVER THE NORTH
HALF OF THE CWA...MAINLY FROM TWIN LAKES AND HOUGHTON SOUTHEAST TO
MANISTIQUE/NEWBERRY. WITH THE DIFFERENCES IN THE EXACT LOCATION OF
THE WAA...DID SHIFT THE PCPN CHANCES A LITTLE FARTHER SOUTH BASED
OFF LATEST VARIABILITY IN THE MODELS AND POTENTIAL FARTHER S
SOLUTION. THE BEST FORCING IS WITHIN THE SNOW GROWTH ZONE AND WITH
THE LLVL TEMPS OVER THE KEWEENAW PENINSULA NOW REMAINING AT OR A
DEGREE ABOVE FREEZING AND DURING THE COOLEST TIME OF THE DAY...THINK
THE INTENSITY OF THE PCPN SHOULD ALLOW IT TO FALL AS SNOW. THIS
MODERATE...TO POTENTIALLY HEAVY...SNOW FALLING JUST BEFORE DAYBREAK
COULD CAUSE SOME TRAVEL ISSUES IN THE KEWEENAW ON THURSDAY MORNING.
RIGHT NOW...HAVE AROUND 2 INCHES OVER THE HIGHER TERRAIN WITH LESSER
AMNTS AT LOWER ELEVATIONS AND NEAR THE SHORELINE WHERE IT WILL MIX
WITH RAIN. THIS IS A VERY DIFFICULT FORECAST FOR THE KEWEENAW WITH
SUBTLE CHANGES MAKING A DIFFERENCE BETWEEN RAIN/SNOW.
ELSEWHERE...PCPN AMNTS ARE A LITTLE MORE UNCERTAIN...BUT STILL
THINK MUCH OF THE AREA WOULD SEE SNOW OR A RAIN/SNOW MIX AS INITIAL
DRY LLVL AIR AIDS EVAPORATIVE COOLING. ACCUMULATIONS WILL TAPER
OFF FROM AN INCH OVER THE NCNTRL TO A DUSTING TO THE SOUTH...IF THE
GROUND ISN/T TOO WARM THERE.
BEHIND THE SHORTWAVE...THERE WILL LIKELY BE A 6-12HR GAP IN THE PCPN
BEFORE THE LAKE EFFECT PCPN PICKS UP THURS AFTN WHEN THE -5C H850
TEMPS ARRIVE AND FALL TO -7C ON THURS NIGHT. THE COOL WATER TEMPS
OVER WRN LAKE SUPERIOR PUTS THE WRN CWA UNDER MARGINAL DELTA-T
VALUES...BUT THE EAST SHOULD STILL SEE FAVORABLE VALUES. DRY MID LVL
AIR WILL SURGE IN BEHIND THE SHORTWAVE AND HELP INHIBIT CLOUD DEPTH
UNTIL IT SLIDES SOUTH ON THURS NIGHT. WITH THE LIMITED CONDITIONS
OVER THE WEST...WILL ONLY GO SLIGHT/CHANCES OVER THE WEST AND HIGH
CHANCES AND LIKELY/S OVER THE EAST FOR LOCATIONS FAVORED BY NW
WINDS.
HIGH PRESSURE WILL BUILD OVER THE GREAT LAKES REGION ON
FRIDAY...BRINGING AN END TO THE LAKE EFFECT PCPN QUICKLY IN THE
MORNING. FRIDAY WILL LIKELY BE THE NICEST DAY OF THE WEEK...WITH
PARTLY/MOSTLY SUNNY SKIES AND TEMPERATURES IN THE UPPER 40S.
ATTENTION THEN TURNS TO THE WEEKEND SYSTEM. THINGS STILL SEEM TO BE
ON TRACK WITH THE SURFACE LOW TRACKING ACROSS UPPER MICHIGAN ON
SATURDAY NIGHT...ALTHOUGH THE LATE ARRIVING 12Z ECMWF HAS PUSHED
THE LOW A LITTLE FARTHER SE. WITH THE TRACK OF THE SYSTEM AND THE
MOISTURE BROUGHT UP FROM THE SW...LATEST INDICATIONS ARE FOR A
WIDESPREAD 0.75 PLUS OF RAIN ACROSS UPPER MICHIGAN. THE ONLY THING
THAT COULD CAUSE ISSUES WITH PCPN AMNTS AT THIS TIME WOULD BE THE
DRY SLOT THAT TRIES TO SURGE NE INTO THE SCNTRL CWA ON SAT NIGHT AS
THE LOW MOVES DIRECTLY OVERHEAD.
HIGH PRESSURE WILL MOVE IN BEHIND THE LOW ON SUNDAY NIGHT INTO
MONDAY...BEFORE THE NEXT SHORTWAVE ARRIVES ON MONDAY NIGHT AND
TUES. TEMPS SHOULD CLIMB BACK TO MORE NORMAL VALUES THIS WEEKEND
INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 136 PM EDT TUE OCT 9 2012
PER REGIONAL RADARS...BAND OF -RA IS STREAKING NE INTO UPPER MI
ATTM. KSAW WILL BE MOST AFFECTED...AND EXPECT A PERIOD OF MVFR
CONDITIONS THERE THIS AFTN AS STEADIER/HEAVIER PCPN PASSES.
KIWD/KCMX ARE ON THE WRN FRINGE OF PCPN AND SHOULD REMAIN VFR THOUGH
CIGS MAY BRIEFLY DROP TO MVFR AT TIMES. AS COLDER AIR PUSHES INTO
THE AREA TONIGHT...INCREASING INSTABILITY OVER THE LAKE WILL RESULT
IN MVFR CIGS/LAKE EFFECT -SHRA THAT MIX WITH/CHANGE TO -SN
OVERNIGHT...MAINLY AT KIWD/KCMX WITH UPSLOPE WIND COMPONENT.
DOWNSLOPE NATURE OF THE WNW FLOW AT KSAW WILL LIKELY PREVENT ANY
SIGNIFICANT PCPN AND MAKE VFR CIGS A GREATER POSSIBILITY THAN AT
KIWD/KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EDT TUE OCT 9 2012
COLD FRONT/TROF WILL PUSH ACROSS LAKE SUPERIOR TONIGHT. WINDS IN
GENERAL WILL REMAIN IN THE 20-30KT RANGE...BUT AFTER THE COLD FRONT
PASSES...COLDER AIR WILL RESULT IN INCREASING OVERWATER INSTABILITY
AND DEEPER MIXING. ALONG WITH INCREASED MIXING...PRES RISES
APPROACHING FROM THE NW MAY HELP PUSH WIND GUSTS TO GALE FORCE AT
TIMES OVERNIGHT THRU WED MORNING FROM NCNTRL INTO SCNTRL/SE LAKE
SUPERIOR.
AN UPPER LEVEL DISTURBANCE AND LOW PRESSURE SYSTEM WILL SLIDE EAST
ACROSS LAKE SUPERIOR LATE WEDNESDAY NIGHT AND THURSDAY. BEHIND THIS
LOW...EXPECT NORTHWEST WINDS TO INCREASE ON THURSDAY TO
30KTS...WITH A FEW GALE FORCE GUSTS TO 35KTS OVER THE EAST HALF IN
THE AFTERNOON. HIGH PRESSURE WILL THEN MOVE ACROSS LAKE SUPERIOR ON
FRIDAY AND DECREASE WINDS BELOW 20KTS. THE NEXT LOW PRESSURE SYSTEM
WILL MOVE OUT OF THE CENTRAL PLAINS ON FRIDAY NIGHT AND ACROSS
UPPER MICHIGAN ON SATURDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...ROLFSON/SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
137 PM EDT TUE OCT 9 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EDT TUE OCT 9 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW MEAN UPR TROF
STILL DOMINATING ERN NAMERICA DOWNSTREAM OF UPR RDG OFF THE W COAST
OF CANADA. TWO DISTURBANCES OF NOTE ARE EMBEDDED IN THIS TROF. THE
FIRST IS CURRENTLY MOVING THRU THE UPR GRT LKS...WITH 999MB SFC LO
OVER ONTARIO. AT 06Z...ATTENDANT COLD FNT IS PUSHING INTO THE WRN
CWA...PRECEDED BY A BAND OF SCT -SHRA STRETCHING FM JUST E OF THE
KEWEENAW SWWD INTO NCENTRAL WI. STRONG S WINDS ARE EVIDENT UNDER THE
SHARPER PRES GRADIENT TO THE E AS 00Z GRB RAOB INDICATED WINDS UP TO
39KTS AS LO AS 2K FT AGL AND UNSTABLE LLVL LAPSE RATES. THE WINDS
ARE STRONGEST AT EXPOSED LOCATIONS NEAR LK MI...WHERE WINDS GUSTED
AS HI AS 45-55 MPH AT SEVERAL SITES YDAY EVNG. WHILE THE DRYNESS OF
THE SUB H8 LYR SHOWN ON THE 00Z GRB RAOB RESTRICTED PCPN COVERAGE/
AMOUNTS OVER MUCH OF THE CWA AHEAD OF THE COLD FNT...MORE SHRA ARE
NOTED OVER THE ERN CWA WHERE THE S WIND UP THE LENGTH OF LK MI
ALLOWED SUFFICIENT MOISTENING TO OVERCOME THIS LLVL DRY AIR. BUT
THIS PCPN IS TENDING TO DRIFT INTO FAR ERN UPR MI AND OUT OF THE MQT
CWA. TO THE W...THERE IS PARTIAL CLRG OVER MUCH OF CENTRAL AND SRN
MN BEHIND THE COLD FROPA AS DRIER AIR SHOWN ON THE 00Z MPX RAOB
ADVECTS TO THE ENE. BUT MORE HI AND MID CLDS ASSOCIATED WITH A
STRONGER SECOND SHRTWV DROPPING SEWD INTO THE NRN PLAINS ARE
SPREADING TO THE E THRU MN AT THE SAME TIME. THE APRCH OF THIS
SHRTWV IS ALSO CAUSING A GREATER COVERAGE OF -SHRA ON THE SRN EDGE
OF THE COLD FNT OVER SE MN/NRN IOWA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE WHETHER TO ALLOW CURRENT
WIND ADVY FOR THE ERN CWA TO EXPIRE AS SCHEDULED AT 09Z AND EVENTUAL
-RA COVERAGE ASSOCIATED WITH STRONGER SECOND SHRTWV NOW DIGGING INTO
THE NRN PLAINS.
EARLY THIS MRNG...AS SHRTWV/SFC LO TO THE N MOVE TO THE NE...COLD
FNT EXTENDING S THRU UPR MI WL SHIFT TO THE E BUT TEND TO SLOW DOWN
AS SECOND SHRTWV DIGGING THRU THE NRN PLAINS DEEPENS THE UPR TROF
AXIS TO THE W AND THE FLOW ALF BACKS TO MORE SW OVER THE GREAT
LAKES. THE BAND OF -SHRA PRECEDING THE FNT WL LIKELY DRY OUT A BIT
WITH BEST FORCING EXITING TO THE NE AND LLVL DRY AIR LINGERING W OF
LIMITING STREAMLINE OFF LK MI. BUT MOISTENING OFF LK MI MIGHT ALLOW
FOR SOME EHNANCEMENT TO THE COVERAGE AGAIN ONCE THE BAND REACHES
THAT AREA. WITH THE CLOSER APRCH OF THE COLD FNT...THE PRES GRADIENT
OVER THE E WL WEAKEN SUFFICIENTLY TO ALLOW THE STRONGER S WINDS TO
DIMINISH BEFORE 12Z. SO PLANNED EXPIRATION OF WIND ADVY AT 09Z SEEMS
TO BE ON TRACK. OVER THE W...DRYING ALF WL BRING DRY WX FOR THE MOST
PART.
TODAY...AS THE UPR TROF AXIS DEEPENS TO THE W IN RESPONSE TO DIGGING
SECOND SHRTWV...EXPECT AREA OF SHRA NOW ON COLD FNT TO THE S TO
EXPAND AND MOVE NE. LATEST MODEL RUNS SHOW CONSIDERABLE SPREAD ON
WHERE AREA OF SHRA WL IMPACT. THE 00Z LOCAL WRF-ARW/CNDN MODELS ARE
FARTHEST W WITH THE TRACK OF THE HEAVIER PCPN...WHILE THE 00Z NAM IS
FARTHEST TO THE E AND IN LINE WITH CURRENT FCST. CONSIDERING THE
TRENDS ON THE INCOMING DRYING TO THE W BEHIND THE COLD FNT AS WELL
AS FCST SHARPEST H85-5 QVECTOR CNVGC OVER THE E THIS AFTN...TEND TO
THINK THE NAM IS ON THE RIGHT TRACK. THE SHARPEST H85-7 FGEN IS ALSO
OVER THE E. ON THE OTHER HAND...SINCE THE FRONTAL SLOPE WL BE RATHER
FLAT...SOME SHARP H7-5 FGEN/H7-3 QVECTOR CVNGC/H4-2 DVGC IS EVIDENT
FARTHER W AND OVER THE WRN CWA. SO EVEN IF THE HEAVIER PCPN DOES
FALL TO THE E...SUSPECT THERE WL BE AT LEAST SOME SCT -SHRA OVER THE
W...WHERE THE HIER DYNAMICS WL HAVE TO OVERCOME MORE LLVL DRYING. AS
THE SHRTWV/DYNAMIC SUPPORT SHIFTS TO THE NE LATER IN THE DAY...
EXPECT THE POPS TO DIMINISH...LATEST OVER THE E. WITH PLENTY OF CLD
COVER AND A GRADUAL INFLUX OF COOLER AIR...EXPECT LTL DIURNAL RISE
IN TEMPS.
TONIGHT...IN THE WAKE OF THE DEPARTING SHRTWV...A CYC NW LLVL FLOW
WL ADVECT A CHILLY CNDN AIRMASS INTO THE UPR LKS. WITH H85 TEMPS
FALLING AS LO AS -7C/-5C OVER WRN/ERN LK SUP BY 12Z /COMPARED WITH
WATER TEMPS OF 7C AT THE WRN BUOY AND 11C AT THE ERN BUOY/...
OVERWATER INSTABILITY WL BECOME SUFFICIENT FOR LK EFFECT -SHRASN TO
IMPACT AREAS FAVORED BY THE LLVL NW FLOW...ESPECIALLY SINCE DEEPER
MSTR WL EXTEND TO THE DGZ. BUMPED POPS UP IN THESE AREAS ABV MODEL
GUIDANCE. WOULD NOT BE SURPRISED TO SEE 1 TO 2 INCHES OF SNOW ACCUM
OVER THE HIER TERRAIN IN AREAS FAVORED BY NW FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR THEME OF INCREASED WIND WITH SYSTEMS ROLLING THROUGH EVERY
COUPLE OF DAYS WILL CONTINUE FOR THE FORESEEABLE FUTURE.
WEDNESDAY...
THE LARGE SCALE TROUGH OVER MUCH OF THE NATION WILL BE CENTERED
ACROSS THE UPPER GREAT LAKES AT 12Z WEDNESDAY...EDGING E THROUGH THE
DAY...WITH NW FLOW RULING THE AREA. WITH NW FLOW AT THE SFC AND
ALOFT...EXPECT COOL AIR TO REMAIN IN PLACE /850MB TEMPS OF -6 TO
-8C/...WITH UPSLOPE LAKE EFFECT SHOWER ACTIVITY. SNOW WILL LIKELY
MIX IN ACROSS W PORTIONS OF THE CWA BEFORE TEMPS WARM TO NEAR 40F
AND WINDS TURN A BIT MORE WESTERLY. ANY ADDITIONAL SNOW WEDNESDAY
SHOULD TOTAL AROUND A HALF AN INCH OR LESS...AS THE INCOMING SFC
RIDGE HELPS TO SCOUR OUT SOME OF THE LOW LEVEL MOISTURE.
WEDNESDAY NIGHT THROUGH FRIDAY...
THE NEXT CLIPPER-LIKE LOW WILL SLIDE IN FROM THE NORTHWEST LATE
WEDNESDAY NIGHT INTO THURSDAY...MOVING DIRECTLY OVER LAKE SUPERIOR
AT 12Z THURSDAY. AFTER 850MB TEMPS JUMPING UP TO AROUND 0C ON
INCREASED SW WINDS...THEY SHOULD AGAIN FALL TO -6 TO -7C THURSDAY
AFTERNOON. LIKE BEFORE...ANOTHER RIDGE OF HIGH PRESSURE WILL PUSH
IN...DRYING US OUT THURSDAY NIGHT AND FRIDAY. THIS TIME THE SFC HIGH
WILL MOVE OVER OR JUST S OF THE AREA /ACROSS WI AND LAKE MI FRIDAY
AFTERNOON/...WITH MUCH LIGHTER WINDS AT LEAST TEMPORARILY.
FRIDAY NIGHT THROUGH MONDAY...
THE HIGH WILL QUICKLY SLIDE TO THE LOWER GREAT LAKES FRIDAY
NIGHT...AS LOW PRESSURE ORGANIZES OFF THE ROCKIES. THE STRENGTHENING
LOW WILL SLIDE IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING
MUCH WARMER AIR ON STRONG SOUTHERLY WINDS...AND THE POTENTIAL FOR
MODERATE TO HEAVY RAIN...BEFORE EXITING NORTHEAST ON SUNDAY. FCST
MODELS HAVE BEEN FAIRLY CONSISTANT ON THE TRACK OF THE LOW OVER
UPPER MI...SO HAVE INCREASED POPS TO 80 PERCENT OR BETTER SATURDAY
AND SATURDAY NIGHT OVER CENTRAL AND E AREAS...AS WELL AS ADDED A
NON-DIURNAL TEMP TREND SATURDAY NIGHT /PARTICULARLY E WITH THE
CONTINUED S WINDS OFF LAKE MI/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 136 PM EDT TUE OCT 9 2012
PER REGIONAL RADARS...BAND OF -RA IS STREAKING NE INTO UPPER MI
ATTM. KSAW WILL BE MOST AFFECTED...AND EXPECT A PERIOD OF MVFR
CONDITIONS THERE THIS AFTN AS STEADIER/HEAVIER PCPN PASSES.
KIWD/KCMX ARE ON THE WRN FRINGE OF PCPN AND SHOULD REMAIN VFR THOUGH
CIGS MAY BRIEFLY DROP TO MVFR AT TIMES. AS COLDER AIR PUSHES INTO
THE AREA TONIGHT...INCREASING INSTABILITY OVER THE LAKE WILL RESULT
IN MVFR CIGS/LAKE EFFECT -SHRA THAT MIX WITH/CHANGE TO -SN
OVERNIGHT...MAINLY AT KIWD/KCMX WITH UPSLOPE WIND COMPONENT.
DOWNSLOPE NATURE OF THE WNW FLOW AT KSAW WILL LIKELY PREVENT ANY
SIGNIFICANT PCPN AND MAKE VFR CIGS A GREATER POSSIBILITY THAN AT
KIWD/KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE WEEKEND...WITH
ANOTHER SYSTEM SLIDING IN FOR THE WEEKEND. EXITING LOW PRESSURE JUST
NORTH OF LS WILL SWEEP A TROUGH ACROSS CENTRAL AND EASTERN LS
TODAY...WITH A COOLER SECONDARY TROUGH ROTATING THROUGH TONIGHT. THIS
WILL BRING NORTHWESTERLY WINDS BACK TO THE REGION THROUGH EARLY
WEDNESDAY /WITH SOME NW GALE FORCE GUSTS TO 35 KTS WEDNESDAY ACROSS E
LS/. AFTER A QUICK RIDGE PUSHES IN...THE NEXT LOW WILL SLIDE IN FROM
THE NW LATE WEDNESDAY NIGHT INTO THURSDAY /WITH W GUSTS AGAIN OF
30-35KTS THURSDAY INTO THURSDAY EVENING/...BEFORE HIGH PRESSURE MOVES
OVERHEAD WITH TEMPORARILY LIGHTER WINDS FRIDAY. A STRENGTHENING LOW
WILL PUSH IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING STRONGER
SOUTHERLY WINDS BEFORE EXITING NE OF LS ON SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
724 AM EDT TUE OCT 9 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EDT TUE OCT 9 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW MEAN UPR TROF
STILL DOMINATING ERN NAMERICA DOWNSTREAM OF UPR RDG OFF THE W COAST
OF CANADA. TWO DISTURBANCES OF NOTE ARE EMBEDDED IN THIS TROF. THE
FIRST IS CURRENTLY MOVING THRU THE UPR GRT LKS...WITH 999MB SFC LO
OVER ONTARIO. AT 06Z...ATTENDANT COLD FNT IS PUSHING INTO THE WRN
CWA...PRECEDED BY A BAND OF SCT -SHRA STRETCHING FM JUST E OF THE
KEWEENAW SWWD INTO NCENTRAL WI. STRONG S WINDS ARE EVIDENT UNDER THE
SHARPER PRES GRADIENT TO THE E AS 00Z GRB RAOB INDICATED WINDS UP TO
39KTS AS LO AS 2K FT AGL AND UNSTABLE LLVL LAPSE RATES. THE WINDS
ARE STRONGEST AT EXPOSED LOCATIONS NEAR LK MI...WHERE WINDS GUSTED
AS HI AS 45-55 MPH AT SEVERAL SITES YDAY EVNG. WHILE THE DRYNESS OF
THE SUB H8 LYR SHOWN ON THE 00Z GRB RAOB RESTRICTED PCPN COVERAGE/
AMOUNTS OVER MUCH OF THE CWA AHEAD OF THE COLD FNT...MORE SHRA ARE
NOTED OVER THE ERN CWA WHERE THE S WIND UP THE LENGTH OF LK MI
ALLOWED SUFFICIENT MOISTENING TO OVERCOME THIS LLVL DRY AIR. BUT
THIS PCPN IS TENDING TO DRIFT INTO FAR ERN UPR MI AND OUT OF THE MQT
CWA. TO THE W...THERE IS PARTIAL CLRG OVER MUCH OF CENTRAL AND SRN
MN BEHIND THE COLD FROPA AS DRIER AIR SHOWN ON THE 00Z MPX RAOB
ADVECTS TO THE ENE. BUT MORE HI AND MID CLDS ASSOCIATED WITH A
STRONGER SECOND SHRTWV DROPPING SEWD INTO THE NRN PLAINS ARE
SPREADING TO THE E THRU MN AT THE SAME TIME. THE APRCH OF THIS
SHRTWV IS ALSO CAUSING A GREATER COVERAGE OF -SHRA ON THE SRN EDGE
OF THE COLD FNT OVER SE MN/NRN IOWA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE WHETHER TO ALLOW CURRENT
WIND ADVY FOR THE ERN CWA TO EXPIRE AS SCHEDULED AT 09Z AND EVENTUAL
-RA COVERAGE ASSOCIATED WITH STRONGER SECOND SHRTWV NOW DIGGING INTO
THE NRN PLAINS.
EARLY THIS MRNG...AS SHRTWV/SFC LO TO THE N MOVE TO THE NE...COLD
FNT EXTENDING S THRU UPR MI WL SHIFT TO THE E BUT TEND TO SLOW DOWN
AS SECOND SHRTWV DIGGING THRU THE NRN PLAINS DEEPENS THE UPR TROF
AXIS TO THE W AND THE FLOW ALF BACKS TO MORE SW OVER THE GREAT
LAKES. THE BAND OF -SHRA PRECEDING THE FNT WL LIKELY DRY OUT A BIT
WITH BEST FORCING EXITING TO THE NE AND LLVL DRY AIR LINGERING W OF
LIMITING STREAMLINE OFF LK MI. BUT MOISTENING OFF LK MI MIGHT ALLOW
FOR SOME EHNANCEMENT TO THE COVERAGE AGAIN ONCE THE BAND REACHES
THAT AREA. WITH THE CLOSER APRCH OF THE COLD FNT...THE PRES GRADIENT
OVER THE E WL WEAKEN SUFFICIENTLY TO ALLOW THE STRONGER S WINDS TO
DIMINISH BEFORE 12Z. SO PLANNED EXPIRATION OF WIND ADVY AT 09Z SEEMS
TO BE ON TRACK. OVER THE W...DRYING ALF WL BRING DRY WX FOR THE MOST
PART.
TODAY...AS THE UPR TROF AXIS DEEPENS TO THE W IN RESPONSE TO DIGGING
SECOND SHRTWV...EXPECT AREA OF SHRA NOW ON COLD FNT TO THE S TO
EXPAND AND MOVE NE. LATEST MODEL RUNS SHOW CONSIDERABLE SPREAD ON
WHERE AREA OF SHRA WL IMPACT. THE 00Z LOCAL WRF-ARW/CNDN MODELS ARE
FARTHEST W WITH THE TRACK OF THE HEAVIER PCPN...WHILE THE 00Z NAM IS
FARTHEST TO THE E AND IN LINE WITH CURRENT FCST. CONSIDERING THE
TRENDS ON THE INCOMING DRYING TO THE W BEHIND THE COLD FNT AS WELL
AS FCST SHARPEST H85-5 QVECTOR CNVGC OVER THE E THIS AFTN...TEND TO
THINK THE NAM IS ON THE RIGHT TRACK. THE SHARPEST H85-7 FGEN IS ALSO
OVER THE E. ON THE OTHER HAND...SINCE THE FRONTAL SLOPE WL BE RATHER
FLAT...SOME SHARP H7-5 FGEN/H7-3 QVECTOR CVNGC/H4-2 DVGC IS EVIDENT
FARTHER W AND OVER THE WRN CWA. SO EVEN IF THE HEAVIER PCPN DOES
FALL TO THE E...SUSPECT THERE WL BE AT LEAST SOME SCT -SHRA OVER THE
W...WHERE THE HIER DYNAMICS WL HAVE TO OVERCOME MORE LLVL DRYING. AS
THE SHRTWV/DYNAMIC SUPPORT SHIFTS TO THE NE LATER IN THE DAY...
EXPECT THE POPS TO DIMINISH...LATEST OVER THE E. WITH PLENTY OF CLD
COVER AND A GRADUAL INFLUX OF COOLER AIR...EXPECT LTL DIURNAL RISE
IN TEMPS.
TONIGHT...IN THE WAKE OF THE DEPARTING SHRTWV...A CYC NW LLVL FLOW
WL ADVECT A CHILLY CNDN AIRMASS INTO THE UPR LKS. WITH H85 TEMPS
FALLING AS LO AS -7C/-5C OVER WRN/ERN LK SUP BY 12Z /COMPARED WITH
WATER TEMPS OF 7C AT THE WRN BUOY AND 11C AT THE ERN BUOY/...
OVERWATER INSTABILITY WL BECOME SUFFICIENT FOR LK EFFECT -SHRASN TO
IMPACT AREAS FAVORED BY THE LLVL NW FLOW...ESPECIALLY SINCE DEEPER
MSTR WL EXTEND TO THE DGZ. BUMPED POPS UP IN THESE AREAS ABV MODEL
GUIDANCE. WOULD NOT BE SURPRISED TO SEE 1 TO 2 INCHES OF SNOW ACCUM
OVER THE HIER TERRAIN IN AREAS FAVORED BY NW FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR THEME OF INCREASED WIND WITH SYSTEMS ROLLING THROUGH EVERY
COUPLE OF DAYS WILL CONTINUE FOR THE FORESEEABLE FUTURE.
WEDNESDAY...
THE LARGE SCALE TROUGH OVER MUCH OF THE NATION WILL BE CENTERED
ACROSS THE UPPER GREAT LAKES AT 12Z WEDNESDAY...EDGING E THROUGH THE
DAY...WITH NW FLOW RULING THE AREA. WITH NW FLOW AT THE SFC AND
ALOFT...EXPECT COOL AIR TO REMAIN IN PLACE /850MB TEMPS OF -6 TO
-8C/...WITH UPSLOPE LAKE EFFECT SHOWER ACTIVITY. SNOW WILL LIKELY
MIX IN ACROSS W PORTIONS OF THE CWA BEFORE TEMPS WARM TO NEAR 40F
AND WINDS TURN A BIT MORE WESTERLY. ANY ADDITIONAL SNOW WEDNESDAY
SHOULD TOTAL AROUND A HALF AN INCH OR LESS...AS THE INCOMING SFC
RIDGE HELPS TO SCOUR OUT SOME OF THE LOW LEVEL MOISTURE.
WEDNESDAY NIGHT THROUGH FRIDAY...
THE NEXT CLIPPER-LIKE LOW WILL SLIDE IN FROM THE NORTHWEST LATE
WEDNESDAY NIGHT INTO THURSDAY...MOVING DIRECTLY OVER LAKE SUPERIOR
AT 12Z THURSDAY. AFTER 850MB TEMPS JUMPING UP TO AROUND 0C ON
INCREASED SW WINDS...THEY SHOULD AGAIN FALL TO -6 TO -7C THURSDAY
AFTERNOON. LIKE BEFORE...ANOTHER RIDGE OF HIGH PRESSURE WILL PUSH
IN...DRYING US OUT THURSDAY NIGHT AND FRIDAY. THIS TIME THE SFC HIGH
WILL MOVE OVER OR JUST S OF THE AREA /ACROSS WI AND LAKE MI FRIDAY
AFTERNOON/...WITH MUCH LIGHTER WINDS AT LEAST TEMPORARILY.
FRIDAY NIGHT THROUGH MONDAY...
THE HIGH WILL QUICKLY SLIDE TO THE LOWER GREAT LAKES FRIDAY
NIGHT...AS LOW PRESSURE ORGANIZES OFF THE ROCKIES. THE STRENGTHENING
LOW WILL SLIDE IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING
MUCH WARMER AIR ON STRONG SOUTHERLY WINDS...AND THE POTENTIAL FOR
MODERATE TO HEAVY RAIN...BEFORE EXITING NORTHEAST ON SUNDAY. FCST
MODELS HAVE BEEN FAIRLY CONSISTANT ON THE TRACK OF THE LOW OVER
UPPER MI...SO HAVE INCREASED POPS TO 80 PERCENT OR BETTER SATURDAY
AND SATURDAY NIGHT OVER CENTRAL AND E AREAS...AS WELL AS ADDED A
NON-DIURNAL TEMP TREND SATURDAY NIGHT /PARTICULARLY E WITH THE
CONTINUED S WINDS OFF LAKE MI/.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 722 AM EDT TUE OCT 9 2012
DESPITE THE APRCH OF AN UPR DISTURBANCE THAT WL BRING SOME -SHRA
THAT IMPACT SAW THIS AFTN...EXPECT VFR CONDITIONS TO PREDOMINATE
TODAY AT ALL 3 TAF SITES WITH LLVL W-SW FLOW ADVECTING DRY AIR SHOWN
ON THE 00Z MPX RAOB OVER UPR MI. THE PASSAGE OF A COLD FNT
ASSOCIATED WITH THIS UPR DISTURBANCE WL CAUSE A WSHFT TO THE NW
TNGT. AS COLDER AIR PUSHES INTO THE AREA...INCRSG LLVL INSTABILITY
WL RESULT IN GUSTY NW WINDS...ESPECIALLY AT THE MORE EXPOSED CMX
SITE. THE ARRIVAL OF THE COLDER AIR WL ALSO BRING MVFR CIGS/LK
EFFECT -SHRA THAT MIX WITH/CHG TO SN OVERNGT...ESPECIALLY AT IWD/CMX
WITH UPSLOPE WIND COMPONENT. DOWNSLOPE NATURE OF THE FLOW AT SAW WL
LIKELY PREVENT ANY SGNFT PCPN AND MAKE VFR CIGS A GREATER
POSSIBILITY THAN AT IWD/CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE WEEKEND...WITH
ANOTHER SYSTEM SLIDING IN FOR THE WEEKEND. EXITING LOW PRESSURE JUST
NORTH OF LS WILL SWEEP A TROUGH ACROSS CENTRAL AND EASTERN LS
TODAY...WITH A COOLER SECONDARY TROUGH ROTATING THROUGH TONIGHT. THIS
WILL BRING NORTHWESTERLY WINDS BACK TO THE REGION THROUGH EARLY
WEDNESDAY /WITH SOME NW GALE FORCE GUSTS TO 35 KTS WEDNESDAY ACROSS E
LS/. AFTER A QUICK RIDGE PUSHES IN...THE NEXT LOW WILL SLIDE IN FROM
THE NW LATE WEDNESDAY NIGHT INTO THURSDAY /WITH W GUSTS AGAIN OF
30-35KTS THURSDAY INTO THURSDAY EVENING/...BEFORE HIGH PRESSURE MOVES
OVERHEAD WITH TEMPORARILY LIGHTER WINDS FRIDAY. A STRENGTHENING LOW
WILL PUSH IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING STRONGER
SOUTHERLY WINDS BEFORE EXITING NE OF LS ON SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ266-267.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LMZ248-250.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
439 AM EDT TUE OCT 9 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 438 AM EDT TUE OCT 9 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW MEAN UPR TROF
STILL DOMINATING ERN NAMERICA DOWNSTREAM OF UPR RDG OFF THE W COAST
OF CANADA. TWO DISTURBANCES OF NOTE ARE EMBEDDED IN THIS TROF. THE
FIRST IS CURRENTLY MOVING THRU THE UPR GRT LKS...WITH 999MB SFC LO
OVER ONTARIO. AT 06Z...ATTENDANT COLD FNT IS PUSHING INTO THE WRN
CWA...PRECEDED BY A BAND OF SCT -SHRA STRETCHING FM JUST E OF THE
KEWEENAW SWWD INTO NCENTRAL WI. STRONG S WINDS ARE EVIDENT UNDER THE
SHARPER PRES GRADIENT TO THE E AS 00Z GRB RAOB INDICATED WINDS UP TO
39KTS AS LO AS 2K FT AGL AND UNSTABLE LLVL LAPSE RATES. THE WINDS
ARE STRONGEST AT EXPOSED LOCATIONS NEAR LK MI...WHERE WINDS GUSTED
AS HI AS 45-55 MPH AT SEVERAL SITES YDAY EVNG. WHILE THE DRYNESS OF
THE SUB H8 LYR SHOWN ON THE 00Z GRB RAOB RESTRICTED PCPN COVERAGE/
AMOUNTS OVER MUCH OF THE CWA AHEAD OF THE COLD FNT...MORE SHRA ARE
NOTED OVER THE ERN CWA WHERE THE S WIND UP THE LENGTH OF LK MI
ALLOWED SUFFICIENT MOISTENING TO OVERCOME THIS LLVL DRY AIR. BUT
THIS PCPN IS TENDING TO DRIFT INTO FAR ERN UPR MI AND OUT OF THE MQT
CWA. TO THE W...THERE IS PARTIAL CLRG OVER MUCH OF CENTRAL AND SRN
MN BEHIND THE COLD FROPA AS DRIER AIR SHOWN ON THE 00Z MPX RAOB
ADVECTS TO THE ENE. BUT MORE HI AND MID CLDS ASSOCIATED WITH A
STRONGER SECOND SHRTWV DROPPING SEWD INTO THE NRN PLAINS ARE
SPREADING TO THE E THRU MN AT THE SAME TIME. THE APRCH OF THIS
SHRTWV IS ALSO CAUSING A GREATER COVERAGE OF -SHRA ON THE SRN EDGE
OF THE COLD FNT OVER SE MN/NRN IOWA.
MAIN FCST CONCERNS IN THE SHORT TERM ARE WHETHER TO ALLOW CURRENT
WIND ADVY FOR THE ERN CWA TO EXPIRE AS SCHEDULED AT 09Z AND EVENTUAL
-RA COVERAGE ASSOCIATED WITH STRONGER SECOND SHRTWV NOW DIGGING INTO
THE NRN PLAINS.
EARLY THIS MRNG...AS SHRTWV/SFC LO TO THE N MOVE TO THE NE...COLD
FNT EXTENDING S THRU UPR MI WL SHIFT TO THE E BUT TEND TO SLOW DOWN
AS SECOND SHRTWV DIGGING THRU THE NRN PLAINS DEEPENS THE UPR TROF
AXIS TO THE W AND THE FLOW ALF BACKS TO MORE SW OVER THE GREAT
LAKES. THE BAND OF -SHRA PRECEDING THE FNT WL LIKELY DRY OUT A BIT
WITH BEST FORCING EXITING TO THE NE AND LLVL DRY AIR LINGERING W OF
LIMITING STREAMLINE OFF LK MI. BUT MOISTENING OFF LK MI MIGHT ALLOW
FOR SOME EHNANCEMENT TO THE COVERAGE AGAIN ONCE THE BAND REACHES
THAT AREA. WITH THE CLOSER APRCH OF THE COLD FNT...THE PRES GRADIENT
OVER THE E WL WEAKEN SUFFICIENTLY TO ALLOW THE STRONGER S WINDS TO
DIMINISH BEFORE 12Z. SO PLANNED EXPIRATION OF WIND ADVY AT 09Z SEEMS
TO BE ON TRACK. OVER THE W...DRYING ALF WL BRING DRY WX FOR THE MOST
PART.
TODAY...AS THE UPR TROF AXIS DEEPENS TO THE W IN RESPONSE TO DIGGING
SECOND SHRTWV...EXPECT AREA OF SHRA NOW ON COLD FNT TO THE S TO
EXPAND AND MOVE NE. LATEST MODEL RUNS SHOW CONSIDERABLE SPREAD ON
WHERE AREA OF SHRA WL IMPACT. THE 00Z LOCAL WRF-ARW/CNDN MODELS ARE
FARTHEST W WITH THE TRACK OF THE HEAVIER PCPN...WHILE THE 00Z NAM IS
FARTHEST TO THE E AND IN LINE WITH CURRENT FCST. CONSIDERING THE
TRENDS ON THE INCOMING DRYING TO THE W BEHIND THE COLD FNT AS WELL
AS FCST SHARPEST H85-5 QVECTOR CNVGC OVER THE E THIS AFTN...TEND TO
THINK THE NAM IS ON THE RIGHT TRACK. THE SHARPEST H85-7 FGEN IS ALSO
OVER THE E. ON THE OTHER HAND...SINCE THE FRONTAL SLOPE WL BE RATHER
FLAT...SOME SHARP H7-5 FGEN/H7-3 QVECTOR CVNGC/H4-2 DVGC IS EVIDENT
FARTHER W AND OVER THE WRN CWA. SO EVEN IF THE HEAVIER PCPN DOES
FALL TO THE E...SUSPECT THERE WL BE AT LEAST SOME SCT -SHRA OVER THE
W...WHERE THE HIER DYNAMICS WL HAVE TO OVERCOME MORE LLVL DRYING. AS
THE SHRTWV/DYNAMIC SUPPORT SHIFTS TO THE NE LATER IN THE DAY...
EXPECT THE POPS TO DIMINISH...LATEST OVER THE E. WITH PLENTY OF CLD
COVER AND A GRADUAL INFLUX OF COOLER AIR...EXPECT LTL DIURNAL RISE
IN TEMPS.
TONIGHT...IN THE WAKE OF THE DEPARTING SHRTWV...A CYC NW LLVL FLOW
WL ADVECT A CHILLY CNDN AIRMASS INTO THE UPR LKS. WITH H85 TEMPS
FALLING AS LO AS -7C/-5C OVER WRN/ERN LK SUP BY 12Z /COMPARED WITH
WATER TEMPS OF 7C AT THE WRN BUOY AND 11C AT THE ERN BUOY/...
OVERWATER INSTABILITY WL BECOME SUFFICIENT FOR LK EFFECT -SHRASN TO
IMPACT AREAS FAVORED BY THE LLVL NW FLOW...ESPECIALLY SINCE DEEPER
MSTR WL EXTEND TO THE DGZ. BUMPED POPS UP IN THESE AREAS ABV MODEL
GUIDANCE. WOULD NOT BE SURPRISED TO SEE 1 TO 2 INCHES OF SNOW ACCUM
OVER THE HIER TERRAIN IN AREAS FAVORED BY NW FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR THEME OF INCREASED WIND WITH SYSTEMS ROLLING THROUGH EVERY
COUPLE OF DAYS WILL CONTINUE FOR THE FORESEEABLE FUTURE.
WEDNESDAY...
THE LARGE SCALE TROUGH OVER MUCH OF THE NATION WILL BE CENTERED
ACROSS THE UPPER GREAT LAKES AT 12Z WEDNESDAY...EDGING E THROUGH THE
DAY...WITH NW FLOW RULING THE AREA. WITH NW FLOW AT THE SFC AND
ALOFT...EXPECT COOL AIR TO REMAIN IN PLACE /850MB TEMPS OF -6 TO
-8C/...WITH UPSLOPE LAKE EFFECT SHOWER ACTIVITY. SNOW WILL LIKELY
MIX IN ACROSS W PORTIONS OF THE CWA BEFORE TEMPS WARM TO NEAR 40F
AND WINDS TURN A BIT MORE WESTERLY. ANY ADDITIONAL SNOW WEDNESDAY
SHOULD TOTAL AROUND A HALF AN INCH OR LESS...AS THE INCOMING SFC
RIDGE HELPS TO SCOUR OUT SOME OF THE LOW LEVEL MOISTURE.
WEDNESDAY NIGHT THROUGH FRIDAY...
THE NEXT CLIPPER-LIKE LOW WILL SLIDE IN FROM THE NORTHWEST LATE
WEDNESDAY NIGHT INTO THURSDAY...MOVING DIRECTLY OVER LAKE SUPERIOR
AT 12Z THURSDAY. AFTER 850MB TEMPS JUMPING UP TO AROUND 0C ON
INCREASED SW WINDS...THEY SHOULD AGAIN FALL TO -6 TO -7C THURSDAY
AFTERNOON. LIKE BEFORE...ANOTHER RIDGE OF HIGH PRESSURE WILL PUSH
IN...DRYING US OUT THURSDAY NIGHT AND FRIDAY. THIS TIME THE SFC HIGH
WILL MOVE OVER OR JUST S OF THE AREA /ACROSS WI AND LAKE MI FRIDAY
AFTERNOON/...WITH MUCH LIGHTER WINDS AT LEAST TEMPORARILY.
FRIDAY NIGHT THROUGH MONDAY...
THE HIGH WILL QUICKLY SLIDE TO THE LOWER GREAT LAKES FRIDAY
NIGHT...AS LOW PRESSURE ORGANIZES OFF THE ROCKIES. THE STRENGTHENING
LOW WILL SLIDE IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING
MUCH WARMER AIR ON STRONG SOUTHERLY WINDS...AND THE POTENTIAL FOR
MODERATE TO HEAVY RAIN...BEFORE EXITING NORTHEAST ON SUNDAY. FCST
MODELS HAVE BEEN FAIRLY CONSISTANT ON THE TRACK OF THE LOW OVER
UPPER MI...SO HAVE INCREASED POPS TO 80 PERCENT OR BETTER SATURDAY
AND SATURDAY NIGHT OVER CENTRAL AND E AREAS...AS WELL AS ADDED A
NON-DIURNAL TEMP TREND SATURDAY NIGHT /PARTICULARLY E WITH THE
CONTINUED S WINDS OFF LAKE MI/.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 132 AM EDT TUE OCT 9 2012
DESPITE A SERIES OF DISTURBANCES PASSING ACROSS THE UPPER GREAT
LAKES...VFR CONDITIONS SHOULD PREVAIL THRU MOST OF THE TAF PERIOD
AT KIWD/KCMX/KSAW AS LOW-LEVELS REMAIN RELATIVELY DRY UNDER
CONTINUED ADVECTION OF DRIER AIR FROM THE S. DISTURBANCE TONIGHT MAY
STILL PRODUCE A PERIOD OF -SHRA AT KSAW INTO THE EARLY OVERNIGHT.
PASSAGE OF A COLD FRONT WILL LEAD TO GUSTY WINDS INTO THE EARLY
OVERNIGHT. A SECOND DISTURBANCE MOVING INTO THE UPPER GREAT LAKES
TUE WILL BRING A ROUND OF -SHRA TO KSAW. IT APPEARS KCMX/KIWD MAY BE
JUST W OF THE MAIN PCPN AREA. AS A SECONDARY COLD FRONT MOVES
THROUGH THE AREA LATE TUE EVENING...WINDS WILL SHIFT WRLY AND COULD
BRING IN SOME MVFR LAKE CLOUDS INTO KIWD AND KCMX LATE IN THE TAF
PD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 AM EDT TUE OCT 9 2012
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE WEEKEND...WITH
ANOTHER SYSTEM SLIDING IN FOR THE WEEKEND. EXITING LOW PRESSURE JUST
NORTH OF LS WILL SWEEP A TROUGH ACROSS CENTRAL AND EASTERN LS
TODAY...WITH A COOLER SECONDARY TROUGH ROTATING THROUGH TONIGHT. THIS
WILL BRING NORTHWESTERLY WINDS BACK TO THE REGION THROUGH EARLY
WEDNESDAY /WITH SOME NW GALE FORCE GUSTS TO 35 KTS WEDNESDAY ACROSS E
LS/. AFTER A QUICK RIDGE PUSHES IN...THE NEXT LOW WILL SLIDE IN FROM
THE NW LATE WEDNESDAY NIGHT INTO THURSDAY /WITH W GUSTS AGAIN OF
30-35KTS THURSDAY INTO THURSDAY EVENING/...BEFORE HIGH PRESSURE MOVES
OVERHEAD WITH TEMPORARILY LIGHTER WINDS FRIDAY. A STRENGTHENING LOW
WILL PUSH IN FROM THE W AND SW SATURDAY AFTERNOON...BRINGING STRONGER
SOUTHERLY WINDS BEFORE EXITING NE OF LS ON SUNDAY. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR MIZ006-007-
013-014-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ266-267.
GALE WARNING UNTIL 5 AM EDT EARLY THIS MORNING FOR LSZ248>251.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LMZ248-250.
GALE WARNING UNTIL 5 AM EDT EARLY THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
138 AM EDT TUE OCT 9 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 436 PM EDT MON OCT 8 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF
DOMINATING ERN NAMERICA DOWNSTREAM OF A RIDGE/ANTICYCLONE OVER THE
GULF OF ALASKA. A COUPLE OF SHORTWAVES ARE EVIDENT DROPPING SE INTO
THE ERN TROF. ONE IS HEADING INTO NRN MN WHILE A SECOND STRONGER
WAVE IS DROPPING THRU SRN SASKATCHEWAN. AT THE SFC...LOW PRES
ASSOCIATED WITH THE LEAD WAVE IS OVER NW MN WITH SECONDARY CENTER
VCNTY OF LAKE WINNIPEG. IN REPONSE TO APPROACHING SHORTWAVE...12Z
RAOBS AT 850MB SHOW STRONG WAA INTO THE UPPER LAKES...CORRESPONDING
TO STRONG ISENTROPIC ASCENT PER LATEST RUC ANALYSIS. LINGERING DRY
AIR AT THE LOW LEVELS PER 12Z KGRB/KMPX SOUNDING IS SO FAR LIMITING
SRN EXTENT OF PCPN.
SHORT TERM WILL BE ACTIVE WITH THE 2 AFOREMENTIONED SHORTWAVES
AFFECTING THE AREA. PRIMARY CONCERN TONIGHT WILL BE WINDS WITHIN
TIGHT PRES GRADIENT OVER THE AREA...ESPECIALLY THE ERN FCST AREA
WHERE 925MB WINDS ARE PROGGED AT 40-50KT BY NAM/GFS. LOW-LEVEL WIND
MAX WON`T BE PASSING DURING THE FAVORABLE PART OF THE DIURNAL CYCLE
FOR MIXING. HOWEVER...AREA OF DECENT PRES FALLS PASSING JUST N OF
LAKE SUPERIOR WILL CERTAINLY BE AN ENHANCING FACTOR FOR STRONGER
WINDS. SO...CURRENT WIND ADVY LOOKS ON TRACK FOR THE DELTA/SRN
SCHOOLCRAFT WHICH ARE EXPOSED TO STRONG WINDS UP LAKE MICHIGAN.
SINCE S WINDS ARE A VERY FAVORABLE WIND DIRECTION FOR STRONGER WINDS
AT GRAND MARAIS AND KERY...OPTED TO INCLUDE ALGER/NRN SCHOOLCRAFT
AND LUCE COUNTIES IN ADVY AS WELL. AS FOR PCPN...GIVEN RADAR/SFC OB
TRENDS AND MODEL INDICATED PERIOD OF DEEP LAYER FORCING PER QVECTORS
AND STRONG ISENTROPIC ASCENT...SOME -SHRA APPEAR LIKELY TO MOVE
ACROSS THE AREA TONIGHT...ESPECIALLY NRN UPPER MI...DESPITE CURRENT
LOW-LEVEL DRY AIR. ALTHOUGH STRONGER FORCING WILL BEGIN TO LIFT
NE...FLOW UP LAKE MICHIGAN MAY PROVIDE ENOUGH LOW-LEVEL MOISTENING
TO ENHANCE PCPN CHANCE FOR THE ERN FCST AREA.
ON TUE...ATTENTION TURNS TO THE STRONGER SHORTWAVE CURRENTLY
DROPPING THRU SRN SASKATCHEWAN. IN RESPONSE...A NICE SW-NE ORIENTED
BAND OF FRONTOGENESIS DEVELOPS THRU THE WRN GREAT LAKES. MAJORITY OF
GUIDANCE APPEARS TO HAVE A BIT TOO MUCH PCPN ON THE COLD SIDE OF THE
FGEN CIRCULATION. BASED ON FGEN...THE ERN FCST SHOULD BE FAVORED FOR
PCPN...AND GRIDS REFLECT THIS WITH A GRADIENT FROM SCHC/LOW CHC POPS
OVER THE W TO HIGH LIKELY OVER THE E.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 436 PM EDT MON OCT 8 2012
ACTIVE PATTERN CONTINUES THROUGH THE WEEKEND. THE PATTERN FEATURES A
SYSTEM MOVING THROUGH EVERY COUPLE DAYS...FOLLOWED BY 12-24HRS OF LK
EFFECT PRECIPITATION AND THEN A WEAK HIGH PRESSURE RIDGE FOR ANOTHER
12-24HRS. THIS WILL CONTINUE THROUGH SUNDAY NIGHT. DUE TO THE
FREQUENT SYSTEMS MOVING THROUGH...IT WILL BE BREEZY THROUGH MUCH OF
THE PERIOD...ESPECIALLY OVER/NEAR LAKE SUPERIOR...WITH THE ONLY
TIMES WINDS WILL BE LIGHTER ARE DURING THE HIGH PRESSURE RIDGES ON
WED AFTN/EVENING AND FRIDAY.
FIRST LOW PRESSURE SYSTEM EXITING TO THE NE THROUGH ONTARIO AT THE
START OF THE PERIOD WHILE SFC TROUGH WILL BE OVER THE ERN CWA. NAM
DIFFERS FROM THE REST OF THE LARGE SCALE MODELS IN DEVELOPING
ANOTHER LOW OVER ERN LK SUPERIOR AS A SECONDARY SHORTWAVE AND LEFT
FRONT OF UPPER JET MOVE THROUGH. NOT SEEING THAT ON THE
LOCAL/NATIONAL HI-RES WRF RUNS...SO WILL DISREGARD AT THIS POINT.
PCPN SHOULD BE ONGOING OVER THE ERN THIRD OF THE CWA AHEAD OF THE
SFC TROUGH AND ASSOCIATED WITH SHORTWAVE FORCING.
BEHIND THE TROUGH...WINDS WILL SHIFT TO THE NW AND COLDER H850
TEMPS WILL SURGE SE...FALLING TO -7C BY 12Z WED. LAKE
EFFECT SHOWERS SHOULD DEVELOP THROUGH THE NIGHT...WITH THE
STRONGEST INTENSITY OVERNIGHT INTO WED MORNING. CURRENT FORECAST IS
FOR ABOUT AN INCH OVER THE HIGHER TERRAIN AREAS OF THE WRN U.P.
TUES NIGHT INTO WED MORNING. LLVL MOISTURE WILL QUICKLY PULL OUT
FROM W TO E DURING THE DAY WED AS WINDS BACK TO THE WSW IN RESPONSE
TO THE HIGH PRESSURE RIDGE MOVING THROUGH.
NEXT LOW PRESSURE SYSTEM MOVES RIGHT ACROSS LAKE SUPERIOR AS
SHORTWAVE DROPS THROUGH THE WNW FLOW. WITH THE BEST WAA/FORCING
LIKELY OVER LK SUPERIOR...WILL CONTINUE TO MENTION HIGHEST POPS
THERE AND ONLY SLIGHTS/CHANCES OVER THE SRN CWA. P-TYPE COULD BE AN
ISSUE WITH THIS SYSTEM OVER THE NRN PART OF THE CWA...MAINLY OVER
THE KEWEENAW. WITH THE DEEP MOISTURE THROUGH THE SNOW GROWTH
LAYER...EXPECT THE PCPN TO START AS SNOW. BUT LOOKING AT THE LOWER
LEVELS...DOESN/T APPEAR TO BE TOO MUCH WARM AIR TO WORK WITH. A
NEARLY ISOTHERMAL LAYER AT FREEZING FROM 1-3KFT BEFORE WARMING A
DEGREE OR TWO ABOVE FREEZING AT THE SURFACE. IN THE HEAVIER PCPN
AREAS...WOULD THINK THIS WOULD DEFINITELY STAY AS ALL SNOW...BUT
LIGHTER AREAS WOULD PROBABLY BE A MIX. FARTHER SOUTH...EXPECT A
RAIN/SNOW MIX DUE TO THE LIKELY WEAKER INTENSITY. ONCE
AGAIN...SHOULD SEE SOME LAKE EFFECT SHOWERS BEHIND THE LOW ON THURS
NIGHT INTO FRIDAY...BEFORE HIGH PRESSURE BUILDS BACK IN AND BRINGS
AN END TO THE SHOWERS.
WEEKEND SYSTEM HAS SHIFTED A LITTLE FARTHER NORTH OVER THE LAST
DAY...WITH THE STRENGTHENING SURFACE LOW NOW TRACKING OVER UPPER MI.
THIS SYSTEM IS CAUSED BY THE UPPER LOW CURRENTLY OFF THE CALIFORNIA
COAST MOVING THROUGH THE SW CONUS THIS WEEK AND EXITING INTO THE
PLAINS ON FRI NIGHT. LOCATION AND TIMING ARE IN DECENT AGREEMENT
WITH THE MODELS...ALTHOUGH THE CANADIAN AND IT/S ENS MEMBERS VARY
GREATLY FROM GFS/ECMWF. LOOKING AT 00Z GFS ENS MEMBERS...THE MEAN OF
THE MAJORITY OF MEMBERS WOULD GIVE A SOLN SIMILAR TO THE
00Z DETERMINISTIC ECMWF...WHICH THE 12Z DETERMINISTIC GFS TRENDED
TOWARDS AND WILL FOLLOW THAT SOLN. WITH THE FARTHER NORTH SOLUTION
THAN YESTERDAY...HAVE BUMPED UP POPS FOR THE SAT INTO SUNDAY PERIOD.
WARM AIR SURGING NORTH AHEAD OF THE SYSTEM SHOULD LEAD TO THE PCPN
STAYING RAIN. COULD BE SOME RUMBLES OF THUNDER ON SAT NIGHT...AS
SHOWALTER VALUES FALL TO 0 TO -1C ALONG AND JUST AHEAD OF THE SFC
LOW...ALTHOUGH MID LVL LAPSE RATES ARE MARGINAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 132 AM EDT TUE OCT 9 2012
DESPITE A SERIES OF DISTURBANCES PASSING ACROSS THE UPPER GREAT
LAKES...VFR CONDITIONS SHOULD PREVAIL THRU MOST OF THE TAF PERIOD
AT KIWD/KCMX/KSAW AS LOW-LEVELS REMAIN RELATIVELY DRY UNDER
CONTINUED ADVECTION OF DRIER AIR FROM THE S. DISTURBANCE TONIGHT MAY
STILL PRODUCE A PERIOD OF -SHRA AT KSAW INTO THE EARLY OVERNIGHT.
PASSAGE OF A COLD FRONT WILL LEAD TO GUSTY WINDS INTO THE EARLY
OVERNIGHT. A SECOND DISTURBANCE MOVING INTO THE UPPER GREAT LAKES
TUE WILL BRING A ROUND OF -SHRA TO KSAW. IT APPEARS KCMX/KIWD MAY BE
JUST W OF THE MAIN PCPN AREA. AS A SECONDARY COLD FRONT MOVES
THROUGH THE AREA LATE TUE EVENING...WINDS WILL SHIFT WRLY AND COULD
BRING IN SOME MVFR LAKE CLOUDS INTO KIWD AND KCMX LATE IN THE TAF
PD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 PM EDT MON OCT 8 2012
TIGHT PRES GRADIENT BTWN LOW PRES APPROACHING FROM NW MN AND HIGH
PRES TO THE E COMBINED WITH AREA OF PRES FALLS PASSING JUST N OF
LAKE SUPERIOR WILL RESULT IN S GALES ACROSS ROUGHLY THE E HALF OF
LAKE SUPERIOR TONIGHT. COULD BE A FEW HRS LATE EVENING INTO THE
EARLY OVERNIGHT WITH GUSTS TO AROUND 45KT AT HIGHER OBS PLATFORMS.
WITH PASSAGE OF COLD FRONT...WINDS WILL DIMINISH SOME OVERNIGHT.
HOWEVER...WIND SWITCH TO THE WSW ALONG WITH PRES RISE HEADING FOR
WRN LAKE SUPERIOR COULD LEAD TO A SHORT PERIOD OF GALE FORCE GUSTS
IN THE AREA BTWN ISLE ROYALE AND THE KEWEENAW. WEAKENING PRES
GRADIENT WILL LEAD TO WINDS DIMINISHING TO MOSTLY 15-25KT TUE.
ACTIVE PERIOD ON LAKE SUPERIOR CONTINUES TUESDAY NIGHT AS NORTHWEST
WINDS INCREASE TO 30KTS BEHIND THE SURFACE TROUGH MOVING ACROSS THE
LAKE ON TUESDAY. THERE COULD BE SOME GALE FORCE GUSTS TO 35KTS OVER
THE EASTERN LAKE TUESDAY NIGHT INTO WEDNESDAY...BEFORE A HIGH
PRESSURE RIDGE DECREASES WINDS BELOW 25KTS. THE NEXT SYSTEM WILL MOVE
ACROSS LAKE SUPERIOR LATE WEDNESDAY NIGHT INTO THURSDAY. THIS WILL
AGAIN PRODUCE WEST GUSTS TO 30-35KTS ON THURSDAY AND THURSDAY
EVENING. WEAKER WINDS WILL PREVAIL ON FRIDAY AS HIGH PRESSURE SLIDES
OVER THE GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY UNTIL 5 AM EDT EARLY THIS MORNING FOR MIZ006-007-
013-014-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LSZ265>267.
GALE WARNING UNTIL 5 AM EDT EARLY THIS MORNING FOR LSZ248>251.
LAKE MICHIGAN...
GALE WARNING UNTIL 8 AM EDT THIS MORNING FOR LMZ248-250.
GALE WARNING UNTIL 5 AM EDT EARLY THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...VOSS
MARINE...ROLFSON/SRF
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
940 PM CDT WED OCT 10 2012
.UPDATE...
A FEW CHANGES HAVE BEEN MADE TO THE FORECAST FOR THE OVERNIGHT AND
THURSDAY MORNING PERIODS.
FIRST OFF...CURRENT TEMPERATURES ACROSS MUCH OF THE FORECAST AREA
ARE NEARING PREVIOUSLY FORECASTED LOWS. MOSTLY CLEAR SKIES...LIGHT
WINDS...AND DEW POINTS WELL DOWN IN THE 30S HAVE RESULTED IN
TEMPERATURES DROPPING OFF VERY QUICKLY THIS EVENING. INCREASING
WINDS FROM THE SOUTH ALONG WITH INCREASING CLOUDS WILL STEADY
TEMPERATURES OFF LATER TONIGHT ACROSS THE EASTERN OZARKS...WITH
TEMPERATURES LIKELY RISING ACROSS WESTERN MISSOURI AND
SOUTHEASTERN KANSAS. NEVERTHELESS...LOWS OVER MOST LOCATIONS WERE
BUMPED DOWN A CATEGORY.
THE SECOND TWEAK TO THE FORECAST WAS TO ADD A SLIGHT CHANCE FOR
THUNDER IN FOR LATE TONIGHT ACROSS SOUTHWESTERN MISSOURI AND
SOUTHEASTERN KANSAS. BOTH THE 00Z NAM AND RAP INDICATE LITTLE
CONVECTIVE INHIBITION LATE TONIGHT FOR SOURCE PARCELS IN THE 800
TO 700 MB LAYER. THESE MODELS ALSO INDICATE THAT ISENTROPIC
UPGLIDE WILL OVERSPREAD THIS GENERAL AREA LATE TONIGHT AS A LOW
LEVEL JET NOSES IN FROM THE SOUTHWEST. GENERALLY KEPT POPS IN THE
SLIGHT CHANCE RANGE FOR NOW AS REGIONAL RAOBS INDICATE THAT THERE
IS WORK TO BE DONE TO OVERCOME A CAPPING INVERSION CENTERED AROUND
750 MB. WE THEN WENT WITH SLIGHTLY HIGHER POPS ACROSS SOUTHERN
MISSOURI FOR THURSDAY MORNING. OTHERWISE...THE SETUP STILL LOOKS
DECENT FOR AT LEAST PATCHY DRIZZLE AS LOW LEVEL MOISTURE SURGES UP
FROM THE SOUTH.
SCHAUMANN
&&
.SHORT TERM (TONIGHT THROUGH SATURDAY)...
THE FORECAST FOR THE NEXT SEVERAL DAYS LOOKS TO BE A BIT OF A MESS
WITH THE POTENTIAL FOR DRIZZLE...RAIN AND THUNDERSTORMS SOME OF
WHICH COULD BE STRONG TO SEVERE.
FOR THE REMAINDER OF TODAY HOWEVER...THE REGION WILL SEE SUNNY
SKIES AND COOL AFTERNOON TEMPERATURES. THIS IS THE RESULT OF
CANADIAN HIGH PRESSURE OVER THE REGION. THE COOL TEMPERATURES ARE
EXPECTED TO REMAIN THROUGH TONIGHT ACROSS CENTRAL MISSOURI AS THE
HIGH PRESSURE SLIDES EAST WITH OVERNIGHT LOW FALLING INTO THE
UPPER 30S.
FOR SOUTHWESTERN MISSOURI AND SOUTHEASTERN KANSAS...SOUTHERLY
FLOW IS EXPECTED TO BEGIN OVERNIGHT AS THE HIGH PRESSURE MOVES
EAST. FAIRLY STRONG WARM AIR AND MOISTURE ADVECTION WILL BE
ONGOING AFTER MIDNIGHT ACROSS THE WESTERN PORTION OF THE AREA AND
KEEP OVER NIGHT LOW TEMPERATURES IN THE LOWER 40S. THE STRENGTH
OF THE MOISTURE AND WARM AIR ADVECTION COMBINED WITH 30KTS OF
ISENTROPIC UPGLIDE...NOTED ON THE NAM...ACROSS THE REGION WILL
PRODUCE PRECIPITATION ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST
STARTING AROUND 09Z. THE SHALLOW NATURE OF THE MOISTURE
HOWEVER...ALL BELOW 700MB AND A CAPPING INVERSION...WOULD INDICATE
DRIZZLE AND SHOWERS SHOULD BE MAIN CONCERN. THIS WILL CONTINUE
INTO THE MIDDLE OF THE DAY WITH LIGHT SHOWERS AND DRIZZLE BEING
MODERATE AT TIMES.
A COLD FRONT WILL SLIDE SOUTH ACROSS THE OZARKS THURSDAY NIGHT
INTO FRIDAY AND FINALLY STALL ACROSS THE MISSOURI/ARKANSAS STATE
LINE. THIS WILL PROVIDE THE FOCUS FOR SHOWERS AND SCATTERED
THUNDERSTORMS FROM LATE THURSDAY NIGHT THROUGH FRIDAY EVENING.
CURRENT MODELS ARE INDICATING SOME DECENT LAPSE RATES AND
INSTABILITY WITH THE FRONT THURSDAY NIGHT. THIS WILL ALLOW FOR THE
DEVELOPMENT OF SOME SCATTERED STRONG TO SEVERE STORMS MAINLY ALONG
AND SOUTH OF INTERSTATE 44. CURRENT INDICATION ARE FOR THE
STRONGEST STORMS TO BE CAPABLE OF PRODUCING HAIL TO QUARTER SIZE
AND LOCALIZED DOWNBURST WINDS.
SHOWERS AND STORMS SHOULD REMAIN SCATTERED INTO MIDDAY FRIDAY AS
THE FRONT BRIEFLY SLIDES SOUTH IN ADVANCE OF A STRONG STORM SYSTEM
THAT BEGINS TO SWING OUT OF THE SOUTHWESTERN CONUS AND INTO THE
CENTRAL PLAINS.
HATCH
&&
.LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...
BIGGEST FORECAST CHALLENGE FOR LATE SATURDAY AND SATURDAY NIGHT IS
THE POTENTIAL FOR SEVERE THUNDERSTORMS. HIGHLY ENERGETIC STORM
SYSTEM WILL LIFT OUT OF THE CENTRAL ROCKIES AND MOVE TOWARD THE
UPPER MIDWEST/WESTERN GREAT LAKES REGION WITH A NEUTRAL TILT
ORIENTATION. THERE WILL NO DOUBT BE STRONG WIND FIELDS ASSOCIATED
WITH THIS SYSTEM...A 50 KT LOW LEVEL JET...70+ KT MID LEVEL
JET...A 100 KT UPPER LEVEL JET...AND DEEP LAYER SHEAR IN EXCESS OF
60KT. HOWEVER...INSTABILITY VALUES REMAIN A CONCERN. THE DEPTH OF
MOISTURE RETURN IS IN QUESTION...THOUGH SURFACE DEWPOINT VALUES
IN THE 60F TO 65F RANGE ALONG/AHEAD OF THE SURGING COLD FRONT
SHOULD YIELD A NARROW BAND OF 500 TO 1000 J/KG OF MLCAPE BY LATE
AFTERNOON SATURDAY FROM WESTERN IOWA SOUTHWESTWARD THROUGH NORTH
CENTRAL TEXAS. 12Z MODEL OUTPUT HAS ONCE AGAIN SLOWED THE
PROGRESSION OF THIS SYSTEM A BIT...WITH TIME OF ARRIVAL MORE SO
IN THE SATURDAY EVENING TIME FRAME FOR THE OUTLOOK AREA. AS A
RESULT...LOSS OF DAYTIME HEATING WILL AT LEAST CAP...IF NOT LIMIT
INSTABILITY VALUES A LITTLE.
NEVERTHELESS...STRONG FORCING WILL HELP YIELD A LINEAR STORM MODE
ALONG THE COLD FRONT AS IT MOVES INTO THE REGION. HIGH SHEAR...LOW
CAPE ENVIRONMENT SUGGESTS STRAIGHT LINE WIND AS A PRIMARY RISK...
WHICH IS FURTHER SUPPORTED BY VERY STRONG WIND FIELDS JUST OFF THE
SURFACE. THE RISK FOR HAIL/TORNADOES IS IN QUESTION AND IT WILL
MOST LIKELY REQUIRE OBSERVING HOW MESOSCALE CONDITIONS UNFOLD TO
HONE IN ON ANY RISK. FOR NOW...CANNOT RULE IT OUT...BUT WOULD LIKE
TO SEE MORE IN THE WAY OF MLCAPE AS WELL AS LOW LEVEL CAPE.
CERTAINLY THIS SYSTEM BEARS WATCHING.
FROM SUNDAY NIGHT THROUGH EARLY TUESDAY...QUIET WEATHER IS
EXPECTED AS SHORTWAVE RIDGING ALOFT BRIEFLY TAKES HOLD IN AN
INCREASING ACTIVE UPPER LEVEL PATTERN. TEMPERATURES WILL BE AROUND
AVERAGE DURING THIS TIME FRAME. FROM LATE TUESDAY THROUGH THE
MIDDLE OF NEXT WEEK...MEDIUM RANGE MODEL OUTPUT CONTINUES TO
SUGGEST ANOTHER FRONTAL PASSAGE AND CHANCE FOR RAINFALL.
TEMPERATURES LOOK TO REMAIN SEASONABLY MILD.
GAGAN
&&
.AVIATION...
LOW AND MID LEVEL MOISTURE WILL INCREASE ACROSS THE REGION
STARTING LATER TONIGHT. MID LEVEL CLOUDS WILL INITIALLY INCREASE
ACROSS SOUTHERN MISSOURI WITH LOW CLOUDS THEN PUSHING IN AROUND
SUNRISE. AT THIS TIME...PRIMARILY MVFR CEILINGS ARE EXPECTED BY
THURSDAY MORNING. THE SETUP ALSO APPEARS FAVORABLE FOR DRIZZLE
THURSDAY MORNING...WHICH WILL AT LEAST MARGINALLY RESTRICT
VISIBILITY. THE ONLY OTHER AVIATION IMPACT OF NOTE WILL BE LOW
LEVEL WIND SHEAR AT KJLN AND KSGF THURSDAY MORNING AS A LOW LEVEL
JET STREAM SHIFTS OVER THE REGION.
SCHAUMANN
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
955 PM MDT WED OCT 10 2012
.UPDATE...
REMOVED POPS THRU THE EARLY MORNING HOURS ACROSS MUCH OF THE SW
MTS AND THE SE PLAINS PER LATEST RUC13 AND 00Z NAM12 SOLUTIONS. 03Z
SATELLITE IMAGERY IS BEGINNING TO SHOW LOW CLOUD DEVELOPMENT OVER
FAR SE NM WHERE LOW LEVEL MOISTURE ADVECTION IS SURGING NW INTO THE
AREA. BUFKIT PROFILES DO FAVOR SOME THICK LOW CLOUDS AND PATCHY FOG
DEVELOPMENT FOR THE PECOS RIVER VALLEY AND SE PLAINS.
SW FLOW AHEAD OF A DEEP UPPER LOW OVER SOCA IS SHOWING SIGNS OF
MOISTENING FROM SOUTH TO NORTH TOWARD NM HOWEVER PRECIP WILL LIKELY
HOLD OFF UNTIL AROUND SUNRISE. ALSO MADE CHANGES TO HIGHEST POPS
FOR THURSDAY THRU FRIDAY MORE IN LINE WITH HPC PROBABILISTIC QPF
GRIDS AND THE LATEST NAM. THE OVERALL SCENARIO REMAINS ON TRACK.
EXPECT THE MOST ACTIVE PERIOD OF PRECIP FROM EARLY FRIDAY MORNING
THRU FRIDAY AFTERNOON AS SIGNIFICANT UPPER DIVERGENCE ALLOWS AN
AREA OF RAIN/STORMS TO DEVELOP ACROSS THE STATE AND SHIFT NORTHEAST
THRU THE DAY WHILE THE PACIFIC FRONT APPROACHES FROM THE WEST. STRONG
TO POTENTIALLY SEVERE STORMS ARE POSSIBLE TOWARD THE TX STATE LINE
FRIDAY. GUYER
&&
.PREV DISCUSSION...602 PM MDT WED OCT 10 2012...
.AVIATION...
00Z TAF CYCLE
NO NOTABLE AVIATION HAZARDS THIS EVE WITH VFR CONDITIONS TO
CONTINUE ALL NIGHT CENTRAL...WEST AND NORTH. BUT MOIST LOW LEVEL
FLOW INTO THE SOUTHEAST AND E CENTRAL PLAINS WILL ENCOURAGE AT
LEAST PATCHY LOW CLOUD AND FOG DEVELOPMENT AS MVFR TO LOCALLY IFR
CIGS AND VISIBILITIES DEVELOP BETWEEN ABOUT 08Z AND 16Z. TAF SITES
THAT THESE LOW CIGS AND POSS FOG ARE MOST LIKELY TO AFFECT INCLUDE
KTCC AND KROW. ALSO A FEW GUSTY TSRA ARE POSSIBLE S OF A LINE FROM
QUEMADO TO KLVS TO KTCC AFTER 19Z THU. 43
.PREV DISCUSSION...307 PM MDT WED OCT 10 2012...
CURRENTLY...RIDGE ALOFT EXTENDING FROM THE TEXAS BIG BEND COUNTRY
SQUARELY ACROSS NEW MEXICO TO GREAT SALT LAKE...AHEAD OF LARGE
WEATHER SYSTEM COILED UP OFF POINT CONCEPCION IN SOUTHERN
CALIFORNIA EN ROUTE TO THE SAN DIEGO AREA. AT THE
SURFACE...STATIONARY BOUNDARY LYING FROM TAOS TO WHITE SANDS
MISSILE RANGE STANDS AS LAST GASP FOR COLD FRONT WHICH DIPPED INTO
THE EASTERN PLAINS OVER THE LAST 24 HOURS. ADVANCING STORM SYSTEM
TOUCHING OFF LIGHTNING STRIKES ACROSS SOUTHERN NEVADA AND SOUTHERN
UTAH...AND ALL THIS IS HEADING FOR NEW MEXICO OVER THE NEXT 48 HOURS.
MODELS...IN GOOD AGREEMENT THROUGH THE UPCOMING WEEKEND AND INTO
NEXT WORK WEEK...WITH SOME MODEST DIFFERENCES EMERGING FROM
TUESDAY ONWARD IN THE DETAILS WITHIN BROADER AGREEMENT ON THE
GENERAL THEME. PLAUSIBLE AND ACCEPTED CONSENSUS MOVES CALIFORNIA
CLOSED LOW TO SAN DIEGO LATE THURSDAY NIGHT AND TO THE FOUR
CORNERS BY FRIDAY AFTERNOON. SYSTEM WILL EJECT RAPIDLY TO THE
PLATTE RIVER VALLEY OF CENTRAL NEBRASKA BY SATURDAY MIDDAY AND
RAPIDLY INTO THE WESTERN GREAT LAKES BY SUNDAY MORNING. EJECTION
SPEED WILL VEER FLOW ALOFT RAPIDLY TO THE NORTHWEST DURING THE DAY
ON SATURDAY...AND SOME FORM OF NORTHWEST FLOW IS IN THE CARDS FOR
NEW MEXICO THROUGH MIDWEEK NEXT WEEK AS RIDGE CORE SETS UP OVER
THE TROPICAL EAST PACIFIC. FROM TUESDAY ONWARD...DOMESTIC GFS
SOLUTION PREFERS A MORE LAMINAR AND STEADY NORTHWEST FLOW RUNNING
JUST NORTH OF NEW MEXICO...WHILE EUROPEAN COLLEAGUES AT ECMWF DIG
BROAD TROUGH OUT OF THE CANADIAN PRAIRIES ACROSS NEW MEXICO TO THE
GULF OF CALIFORNIA...AND THEN MOVES THIS TROUGH INTO THE SOUTHERN
PLAINS BY MIDWEEK. UPSHOT FOR NEW MEXICO WOULD BE A CLOUDIER DAY
WITH SOME ENHANCED SHOWER CHANCES TUESDAY UNDER THE ECMWF
SOLUTION...WITH A DRY AND COOL DAY FOR THE GFS. ECMWF HAS BEEN
DIGGING THESE TROUGHS INTO THE SOUTHWEST FOR THE LAST SEVERAL
STORMS THAT HAVE COME THROUGH...BUT THESE HAVE NOT VERIFIED AS
DEEPLY AS THE ECMWF SOLUTION WOULD SUGGEST. WILL THUS KEEP A LEAN
TOWARD GFS IN THE EXTENDED PERIODS FOR NOW AND AWAIT A BETTER
CONSENSUS IN FUTURE RUNS.
OVERNIGHT...REASONABLY SEASONABLE OVERNIGHT TEMPERATURES
TONIGHT...WITH FREEZES MOSTLY OVER THE NORTHERN MOUNTAINS AND MORE
MILD TEMPERATURES ELSEWHERE. AS RIDGE BREAKS DOWN AND SHIFTS
EASTWARD...SOME ISOLATED THUNDERSTORMS REMAIN A POSSIBILITY OVER
THE SOUTHEAST CORNER OF THE STATE...AS THE FIRST OF THE SOUTHWEST
WINDS CIRCULATING ABOUT THE APPROACHING WEATHER SYSTEM PUSH SOME
DYNAMICAL HELP OVER THE EXISTING MOISTURE. OUTSIDE OF CONVECTIVE
SHOWERS...SOME VISIBILITY REDUCTIONS IN PATCHY FOG ARE POSSIBLE
TOWARDS DAYBREAK...ESPECIALLY NEAR THE TEXAS PANHANDLE ALONG AND
SOUTH OF INTERSTATE 40.
FOR THURSDAY...STORM CENTER APPROACHING SAN DIEGO THURSDAY MORNING
WILL DRIFT INTO THE IMPERIAL AND MOJAVE DESERT COUNTRY OF INLAND
SOUTHERN CALIFORNIA BY THURSDAY EVENING. DIFFLUENT SOUTHWEST FLOW
ACROSS NEW MEXICO WILL EXPAND CLOUD AND SHOWER COVERAGE RAPIDLY
THROUGH THE DAY...WITH HEAVIER SHOWERS SETTING UP OVER THE EAST
CENTRAL PLAINS BY THURSDAY AFTERNOON. SHOWER COVERAGE WILL EXPAND
IN COVERAGE AND INCREASE IN INTENSITY THURSDAY NIGHT...WITH
HEAVIER RAINFALL BUILDING ACROSS THE ARIZONA AND COLORADO LINES IN
THE NORTH AND WEST...AND MORE WIDESPREAD SHOWERS ON TAP FOR THE
EAST. WARM MOIST AIR MOVING INTO THE PLAINS WILL BRING DAYTIME
HIGH TEMPERATURES BACK UP ABOVE NORMAL...WITH NEAR NORMAL
TEMPERATURES IN THE WEST. ADDED CLOUD COVER AND RAINFALL WILL KEEP
OVERNIGHT LOWS MILD.
FOR FRIDAY...THE MAIN EVENT PLAYING OUT...AS STORM CENTER MOVES
FROM SOUTHEAST CALIFORNIA TO THE FOUR CORNERS. SOUTHWEST WINDS
WILL GET AN EARLY BOOST IN SPEEDS IN THE WEST FRIDAY MORNING WITH
GUSTY WINDS SPREADING TO CENTRAL PORTIONS BY MIDDAY AND EXPANDING
INTO THE NORTHEAST PLAINS BY LATE AFTERNOON. FORECAST WINDS
CURRENTLY CROSSING ADVISORY THRESHOLDS BY MID AFTERNOON WITH
SPEEDS TAPERING OFF THROUGH FRIDAY EVENING. A WET DAY IN THE
CARDS...WITH HEAVIEST RAINFALL OVER THE NORTHEAST PLAINS AND
ADJACENT HIGHLANDS THROUGH FRIDAY EVENING. RAPIDLY DEEPENING
SURFACE TROUGH ALONG THE NEW MEXICO EASTERN BORDER WILL SET UP
SURFACE CONVERGENCE...AND WITH AMPLE DYNAMICS IN
PLACE...THUNDERSTORMS NEAR THE TEXAS PANHANDLE FRIDAY AFTERNOON
MAY RUN TO THE STRONG WIDE WITH HAIL AND POSSIBLY DAMAGING WIND.
AND THATS NOT ALL...AS COLDER AIR MOVING IN OVER THE NORTHERN
MOUNTAINS MAY CHANGE RAIN OVER TO AN INCH OR TWO OF WET SNOW
OVERNIGHT FOR THE SAN JUAN...SANGRE DE CRISTO...AND JEMEZ SUMMITS
AND HIGH COUNTRY SLOPES...WITH SOME LESSER AMOUNTS OVER THE
CHUSKAS AND SOME OF THE HIGHER SPOTS ON THE CONTINENTAL DIVIDE.
ACCUMULATIONS WILL BE VISIBLE BUT NOT ESPECIALLY LARGE...WITH SNOW
GETTING A LATE START OVERNIGHT AND FALLING ON RELATIVELY WARM
SURFACES.
FOR SATURDAY...STORM CENTER MOVING RAPIDLY TO NORTHEAST COLORADO
SATURDAY MORNING AND TO THE MISSOURI RIVER VALLEY BY SATURDAY
AFTERNOON. COLD FRONT BARRELING SOUTHWARD IN WAKE OF THE STORM
WILL KEEP DAYTIME HIGH TEMPERATURES 3 TO 8 DEGREES BELOW NORMAL
CENTRAL AND WEST...AND NEAR NORMAL IN THE EXTREME EAST. SHOWER
COVERAGE AND SKIES WILL CLEAR RAPIDLY FROM SOUTHWEST TO NORTHEAST
DURING THE DAY WITH BREEZES CONTINUING OVER THE CENTRAL MOUNTAIN
CHAIN SUMMITS...AND ALONG THE INTERSTATE 40 CORRIDOR ACROSS THE
EASTERN PLAINS.
OUTLOOK...SUNDAY THROUGH TUESDAY...NORTHWEST FLOW MOVING FROM
NORTHERN CALIFORNIA ACROSS THE NORTHEAST HALF OF NEW MEXICO AND
INTO THE DEEP SOUTH SUNDAY WILL CLEAR SKIES AND ALLOW MODEST
WARMING TREND TO TAKE HOLD FOR THE WORK WEEK START...AS SURFACE HIGH
PRESSURE BUILDS INTO THE NORTHWEST HALF OF NEW MEXICO. WARMING
WILL BRING TEMPERATURES 6 TO 12 DEGREES ABOVE NORMAL OVER THE
EASTERN PLAINS...WITH TEMPERATURES CLOSER TO NORMAL CENTRAL AND
WEST. COLD FRONT DROPPING SOUTHWARD WILL RUN TO THE WEAK SIDE AND
LEVEL OFF TEMPERATURES ON MONDAY. COOLER AIR IN PLACE FOR
TUESDAY...WITH SOME AFTERNOON BREEZES DEVELOPING ONCE AGAIN OVER
THE EASTERN SLOPES AND ADJACENT PLAINS OF THE CENTRAL MOUNTAIN
CHAIN TUESDAY AFTERNOON. SPEEDY FLOW CLIPPING NORTHERN NEW MEXICO
MAY KICK OFF SOME EVENING SPRINKLES OR FLURRIES OVER THE HIGH
PEAKS LATE TUESDAY NIGHT. SHY
.FIRE WEATHER...
A CHANGE IN CONDITIONS FROM WARM AND DRY TO A MORE ACTIVE PATTERN
IS EXPECTED THURSDAY AND FRIDAY.
A SHORT WAVE RIDGE IS CURRENTLY POSITIONED OVER NEW MEXICO WITH
ABOVE NORMAL TEMPERATURES ACROSS CENTRAL AND WESTERN ZONES AND SOME
COOLER TEMPERATURES ACROSS THE EASTERN PLAINS IN THE WAKE OF A COLD
FRONT. SOME BREEZY AFTERNOON WINDS WILL PERSIST THROUGH EARLY
EVENING AS RH VALUES DIP BELOW 20 PERCENT ACROSS THE WEST. OVERNIGHT
RH RECOVERIES AREA EXPECTED TO BE FAIR ACROSS MUCH OF CENTRAL AND
WESTERN ZONES WITH GOOD TO EXCELLENT VALUES ACROSS THE EAST. LOW
CLOUDS...SOME FOG WITH A SLIGHT CHANCE FOR SOME WETTING RAIN IS
INTRODUCED INTO THE SOUTHEAST PLAIN TONIGHT.
A NEARLY STATIONARY UPPER LEVEL LOW POSITIONED OFF THE CALIFORNIA
COAST IS PROGGED TO MOVE ONSHORE BY LATE THURSDAY. SOUTHWEST FLOW
IN ADVANCE OF THE SYSTEM WILL SUPPORT STRENGTHENING SOUTH TO
SOUTHWEST WINDS ON THURSDAY...ESPECIALLY OVER THE WEST. CHANCES FOR
WETTING RAIN INCREASE AS WELL. VENTILATION INCREASES TO VERY GOOD TO
EXCELLENT MOST ZONES AND TEMPERATURES REBOUND ACROSS THE EAST.
THERE IS REASONABLY GOOD AGREEMENT ON THE TRACK OF THE UPPER LOW
THURSDAY INTO FRIDAY...WITH A SLOW PROGRESSION EAST AND SOUTH ON
THURSDAY WITH BEST JET...LIFT AND MOISTURE AHEAD OF THE SYSTEM.
HOWEVER...MODELS CAN STRUGGLE WITH THE SPEED OF THE UPPER LOW AND
SOME DRY AIR AHEAD OF THE LOW WILL MAKE THE FORECAST A LITTLE TRICKY
AS WELL. MODELS MOVE THE UPPER LOW TO THE NORTHEAST ON FRIDAY WITH A
TIGHT GRADIENT AND STRONG JET OVER NEW MEXICO. WINDS SHOULD BE THE
STRONGEST ON FRIDAY...WITH A SIGNIFICANT WIND EVENT POSSIBLE...BUT
CURRENT GRIDS MAINTAIN RH WELL ABOVE CRITICAL VALUES. THE BEST
CHANCES FOR WETTING RAIN LOOK TO BE THE NORTH AND EXTREME EAST WHERE
STRONG THUNDERSTORMS ARE POSSIBLE.
MODELS MOVE THE LOW MORE RAPIDLY TO THE NORTHEAST ON SATURDAY...WITH
THE LOW CENTERED NEAR OR OVER NEBRASKA BY MIDDAY. UNDER DEVELOPING
NORTHWEST FLOW ALOFT...COOLER AND MUCH DRIER AIR FILTERS IN OVER THE
STATE.
WARMER AND MOSTLY DRIER CONDITIONS CONTINUE INTO SUNDAY WITH
A WEAKENING GRADIENT AND MUCH LIGHTER WINDS. VENTILATION VALUES LOOK
TO BE POOR TO FAIR.
EXTENDED MODELS MAINTAIN NORTHWEST FLOW AT LEAST THROUGH MID WEEK
WITH DRY AND SEASONABLE WARM TEMPERATURES EXPECTED. 05
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
348 PM EDT TUE OCT 9 2012
.SYNOPSIS...
A WEAK RIDGE OF HIGH PRESSURE WILL SHIFT INTO EASTERN CANADA
TONIGHT...AS A SURFACE COLD FRONT APPROACHES THE SAINT LAWRENCE
VALLEY BY WEDNESDAY. THIS COLD FRONT WILL PRODUCE A BRIEF PERIOD OF
SHOWERS FROM WEST TO EAST ACROSS THE AREA ON WEDNESDAY INTO
WEDNESDAY EVENING...ALONG WITH BREEZY SOUTHERLY WINDS. THESE WINDS
WILL SHIFT TO THE WEST AND COOLER TEMPERATURES WILL ARRIVE BY
THURSDAY. A SECONDARY COLD FRONT WILL PRODUCE MORE LIGHT SHOWERS ON
FRIDAY...WITH SOME HIGH ELEVATION SNOW SHOWERS POSSIBLE...WITH EVEN
COOLER TEMPERATURES AND WIDESPREAD FROST EXPECTED ON SATURDAY
MORNING.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 350 PM EDT TUESDAY...FCST CHALLENGE WL BE TIMING OF FROPA
AND ASSOCIATED POPS/QPF ON WEDS AFTN/EVENING. WATER VAPOR SHOWS
SMALL ENVELOPE OF DRY AIR ACRS OUR CWA THIS AFTN...ASSOCIATED WITH
SUBSIDENCE FROM SYSTEM WELL OFF THE COAST..WITH NEXT RIBBON OF
ENHANCED MOISTURE/VORT DIVING TWD THE CENTRAL GREAT LAKES ATTM.
WEAK PRE-FRNTAL VORT AND RIBBON OF MOISTURE WL LIFT ACRS OUR
WESTERN/CENTRAL CWA THIS EVENING...WITH LLVL ATLANTIC MOISTURE
ADVECTING AROUND HIGH PRES IMPACTING OUR CENTRAL/EASTERN CWA.
PATCHY DRIZZLE/VERY LIGHT RAIN WL BE POSSIBLE ACRS OUR EASTERN ZNS
MTNS TONIGHT. CLOUD GRIDS AND ASSOCIATED TEMPS WL BE TRICKY
TONIGHT. RUC13 925MB TO 700MB RH PROGS SHOW PLENTY OF MOISTURE
ALONG AND EAST OF THE GREEN MTNS THRU THIS EVENING...THEREFORE WL
MENTION MOSTLY CLOUDY SKIES AND KEEP TEMPS IN THE 40S...MAYBE A
FEW 30S NORTHERN ZNS. ELSEWHERE...SKIES SHOULD BE PC WITH TEMPS IN
U30S DACKS TO 40S CPV/SLV.
FOR WEDNESDAY...POTENT S/W ENERGY AND ASSOCIATED ENHANCED RIBBON OF
MID LVL RH WL ENTER THE SLV AROUND 16Z...BE ACRS THE DACKS BTWN
18Z-20Z...CPV AROUND 21Z...AND THRU VT BY 02Z THURS. NAM12 SHOWS
GOOD 925MB FGEN FORCING...GOOD 850 TO 700MB RH/OMEGA FIELDS...AND
PWS VALUES NEAR 0.75"...WHICH WL RESULT IN A 1 TO 3 HR WINDOW OF
SHOWERS. FAST MOVEMENT OF SYSTEM AND LIMITED DEEP LAYER MOISTURE
ADVECTION WL KEEP QPF AMOUNT GENERALLY <0.25"...WITH HIGHEST VALUES
ACRS THE MTNS. HIGH RESOLUTION MODELS SHOW SOME CHANNELING EFFECTS
ACRS THE SLV/CPV WITH LOCALIZED WIND GUSTS BTWN 30 AND 35 MPH
POSSIBLE. PROGGED 85H SOUTHWEST FLW OF 35 TO 40 KNTS AHEAD OF SYSTEM
WL LIMIT QPF/POP CHCS ACRS THE CPV ON WEDS. WL TREND TEMPS SEVERAL
DEGREES ABOVE GUIDANCE GIVEN SOUTHERLY FLW AND PROGGED 925MB TEMPS
NEAR 11C. THINKING M50S MTNS TO M60S VALLEYS...WITH WARMEST READINGS
AT VSF.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 350 PM EDT TUESDAY...MID/UPPER LVL TROF DEEPENS BEHIND SFC
COLD FRNT...BUT STRONG SFC PRES GRADIENT BTWN HIGH PRES ACRS THE
OHIO VALLEY AND DEPARTING LOW PRES WL KEEP TEMPS FROM DROPPING TOO
FAR. GIVEN...A WEST TO NORTHWEST FLW BTWN 925MB AND
850MB...THINKING BEST LAKE EFFECT MOISTURE WL STAY SOUTH OF OUR
CWA ON WEDS NIGHT. THE COMBINATION OF UPSLOPE NW FLW AND LEFTOVER
850 TO 700MB RH...MAY PRODUCE A FEW MTN FLURRIES/SNOW SHOWERS ON
WEDS NIGHT...AS 85H TEMPS COOL BLW 0C. GFS SOUNDINGS AT JAY PEAK
SHOW THIS POTENTIAL...WITH A DUSTING OF SNOW POSSIBLE BY THURS
MORNING FROM SUGARBUSH TO MOUNT MANSFIELD TO JAY PEAK. SOUNDINGS
SHOW WELL MIXED BL WITH CAA ACRS OUR CWA...WL MENTION LOWS FROM
THE U20S MTNS TO U30S VALLEYS AND L40S NEAR LAKE CHAMPLAIN.
ON THURSDAY...SFC RIDGE AXIS MOVES ACRS OUR CWA BY 18Z...WITH RETURN
SOUTHWEST FLW DEVELOPING BY 00Z FRIDAY. BOTH GFS/NAM SHOW ENHANCED
850 TO 500MB RH IMPACTING THE SLV BY 18Z THURS AND SPREADING TWD THE
CPV BY 00Z FRIDAY...ASSOCIATED WITH LOW TO MID WAA AHEAD OF NEXT
SYSTEM. THIS FAST MOVING CLIPPER LIKE SYSTEM WL PUSH ACRS OUR CWA
THUR NIGHT INTO FRIDAY MORNING. THIS NORTHERN STREAM SYSTEM WL HAVE
LIMITED MOISTURE...BUT GIVEN STRONG DYNAMICS AND GOOD SFC
CONVERGENCE...EXPECT ANOTHER BRIEF PERIOD OF SHOWERS OVERNIGHT INTO
FRIDAY MORNING..WITH HIGHEST POPS/QPF CONCENTRATED ACRS THE MTNS.
MUCH COOLER TEMPS ARRIVE ON FRIDAY INTO SATURDAY BEHIND THIS SYSTEM.
FOR THURSDAY...PROGGED 85H TEMPS WARM TO NEAR 0C...BUT INCREASE
CLOUDS MAY LIMIT SFC HEATING/MIXING...THINKING U40S NEK TO NEAR 60F
CPV/SLV. THE COMBINATION OF SOUTHERLY SFC WINDS FROM APPROACHING
BOUNDARY...INCREASING CLOUDS/PRECIP...AND WARMING LLVL THERMAL
PROFILES ON THURS NIGHT...WL MENTION LOWS ABOVE GUIDANCE AND MAINLY
IN THE 40S. HOWEVER...TWD FRIDAY MORNING LLVL CAA DEVELOPS AND
THERMAL PROFILES ABOVE 2000 FT WL BECM COLD ENOUGH TO SUPPORT SOME
SNOW. HAVE MENTION A MIX OF RAIN/SNOW WITH SOME LIGHT ACCUMULATION
POSSIBLE ABOVE 3000 FT AROUND 12Z FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 326 PM EDT TUESDAY...UPPER TROUGH SWINGS THRU THE CWA DURING
THE DAY ON FRIDAY. MDLS CONTINUE TO SHOW SFC RIDGE BUILDING OVER
THE NORTH COUNTRY FRI NGT INTO SATURDAY. SATURDAY NIGHT HAS WARM
FRNTL BOUNDARY SWING THRU THE WESTERN PORTIONS OF THE
CWA...OVERSPREADING THE ENTIRE CWA SLOWLY ON SUNDAY. SFC LOW
ASSOCIATED WITH FRNT LIFTS NORTH OF CWA TRAVELING EAST THRU QUEBEC
INTO MONDAY. TIMING ISSUES WITH EXITING SYSTEM ON MONDAY INTO
TUESDAY AS LATEST ECMWF DIGS UPPER TROUGH FURTHER SOUTH. THIS WILL
POTENTIALLY KEEP PRECIP LONGER OVER THE AREA...WHILE THE LATEST
GFS BRINGS DRIER AIR WITH RIDGE FROM GREAT LKS REGION.
IMPACTS FOR THE NORTH COUNTRY...
FRIDAY...MOST OF THE REGION WILL SEE LGT -RW...EMPHASIS WILL BE OVER
HIR TRRN AS PRECIP TAPERS OFF WITH WNW FLOW OVER THE AREA. SOME --SW
POSSIBLE AT 1500-2000` OR HIR FOR A FEW HRS IN THE MORNING...BECM
ALL -RW BFR ENDING.
FRIDAY NIGHT THRU SATURDAY...CWA WILL RADIATE OUT UNDER CLR SKIES
FRI NGT ALLOWING FOR TEMPS TO DROP INTO THE TEENS AND 20S CWA-WIDE.
COLDER TEMPS IN THE HILLS OF DACKS NE VT. RIDGE SHIFTS EAST DURING
THE DAY SATURDAY ALLOWING FOR WARM UP WITH HGHS INTO THE MID50S AS
SSW FLOW INCR AHEAD OF APPROACHING WARM FRNT.
SATURDAY NIGHT THRU TUESDAY...LGT PRECIP/CLDS INCR OVER N NY SAT NGT
OVERSPREADING CWA BY SUNDAY MORNING. POSITIONING OF WARM FRNT ON
GFS/ECMWF EXTENT OF ANY -SW THAT DEMELOP OVE RHIR TRRN BFR GOING TO
ALL -RW. SYSTEM SLIDES SLOWLY EAST THRU SUN/SUN NGT AS PARENT LOW
SHIFTS INTO SOUTHERN QUEBEC. WILL KEEP CHANCE FOR -RW OVER AREA
THRU PERIOD. LATE SUNDAY NIGHT INTO MONDAY W/ FRNT LIFTING N OF
CWA...PRECIP WILL SCT OUT SOME AS DRIER AIR WORKS INTO AREA. WILL BE
KEEPING CHANCE POPS FOR -RW TRANSITIONING TO LGT -SW OVER HIR AS CD
AIR FILTERS INTO AREA UNDER NW. FOR NOW WITH MDL UNCERTAINTY HAVE
KEPT SL CHANCE FOR TUESDAY FOR SHOWERS.
TEMPS FOR THE EXTENDED BLW NORMAL BY A FEW DEGREES WITH RIDGE
OVERHD...AND INCR TO AT OR ABV NORMAL CONDITIONS DUE TO WARMER
AIRMASS WORKING INTO AREA W/ FRNT.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
THROUGH 18Z WEDNESDAY...MAINLY VFR COND AS REGION REMAINS UNDER
HIGH PRESSURE. CEILINGS WILL RANGE FROM BKN035-060. SLK/MPV/RUT
WILL SEE MVFR MIX IN BY 04Z-05Z W/ TEMPO CEILINGS DROPPING DOWN TO
BKN020-030 AT TIMES. WINDS SSW AROUND 10KTS BECM LGT/VAR BY 00Z
WED...THEN SSW 10-20KTS FROM 07Z-15Z FROM WEST TO EAST.
OUTLOOK 18Z WEDNESDAY THROUGH SATURDAY...
18Z WEDNESDAY THROUGH 12Z THURSDAY...A COLD FRONT WILL MOVE INTO
THE REGION ON WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT WITH
SCATTERED SHOWERS ALONG WITH SOME AREAS OF MVFR.
12Z THURSDAY THROUGH 00Z FRIDAY...MAINLY VFR AS A RIDGE OF HIGH
PRESSURE WILL BE OVER THE REGION.
00Z FRIDAY THROUGH 18Z FRIDAY...TRENDING BKN/OVC VFR WITH SOME
MVFR IN SCATTERED SHOWERS WITH COLD FRONTAL PASSAGE.
18Z FRIDAY THROUGH 18Z SUNDAY...TRENDING VFR AS A RIDGE OF HIGH
PRESSURE BUILDS INTO THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...JN
AVIATION...KGM/JN
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1008 AM EDT TUE OCT 9 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST INTO THE MARITIMES TODAY ALONG WITH
LIGHT SOUTH TO SOUTHEASTERLY WINDS DEVELOPING AND VARIABLE CLOUD
COVER EXPECTED. DRY WEATHER IS EXPECTED. A COLD FRONT WILL SWING
THROUGH THE REGION LATER WEDNESDAY INTO WEDNESDAY EVENING WITH A
RENEWED THREAT OF SHOWERS...WITH ADDITIONAL SHOWERS POSSIBLE
THURSDAY NIGHT WITH YET ANOTHER COLD FRONT. DRY AND CHILLY
WEATHER SETTLES INTO THE REGION FOR FRIDAY INTO EARLY SATURDAY
BEFORE MODERATING TEMPERATURES AND A CHANCE OF SHOWERS RETURN BY
SUNDAY INTO MONDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1010 AM EDT TUESDAY...SFC ANALYSIS SHOWS WEAK RIDGE OF HIGH
PRES ACRS NORTHERN NY INTO CENTRAL/NORTHERN VT THIS MORNING.
MEANWHILE...ANTICYCLONIC FLOW AROUND THIS SYSTEM IS ADVECTING LLVL
MOISTURE/CLOUDS INTO SOUTHERN VT THIS MORNING. LATEST SATL TRENDS
SHOW THESE CLOUDS MOVING INTO CENTRAL VT ATTM...WITH MAINLY CLR
SKIES ACRS NORTHERN VT/NORTHERN NY. WL ADJUST CLOUD COVER GRIDS
BASED ON TRENDS AND TWEAK TEMPS SLIGHTLY COOLER ACRS
RUTLAND/WINDSOR COUNTIES BASED ON MORE CLOUDS. RUC13 925MB TO
700MB RH PROGS SHOWS THIS MOISTURE SLOWLY MOVING NORTHWARD THIS
AFTN...BUT ALSO THINNING THRU TIME. EXPECT PARTLY SUNNY SKIES MOST
OF THE CWA BY THIS AFTN WITH TEMPS IN THE U40S SOUTHERN MTNS TO
NEAR 60 CPV/SLV.
PRIOR DISCO...
1030 HPA SFC HIGH CONTINUES TO PUSH EAST OF THE REGION
INTO THE CANADIAN MARITIMES THIS MORNING WITH MAINLY CLEAR SKIES
AND PATCHY FOG HERE AND THERE. CHALLENGE FOR TODAY WILL BE AREAL
EXTENT/COVERAGE OF LOW TO MID LEVEL STRATUS CLOUDS CURRENTLY
PUSHING SLOWLY NORTH ACROSS THE NRN MID ATLANTIC INTO SRN NEW
ENGLAND. WITH HYSPLIT LOW LEVEL BACK TRAJECTORIES FROM THE
EAST/SOUTHEAST TODAY...FEEL THESE CLOUDS WILL CONTINUE THEIR NORTH
TO NORTHEASTWARD TREK...WITH MANY AREAS FROM THE EASTERN SLOPES OF
THE DACKS EAST ACROSS VT TRENDING PARTLY TO MOSTLY CLOUDY AS THE
MORNING/AFTERNOON WEARS ON. GIVEN FAIRLY SHALLOW MOIST
LAYER...SOME POSSIBILITY THAT AFTERNOON SUN CAN BURN SOME OF THIS
OFF OVER TIME...ESP IN THE CHAMPLAIN VALLEY...BUT WITH MARGINALLY
LOW SUN ANGLE I`M NOT HANGING MY HAT ON IT...ESP ERN VT. FURTHER
WEST MORE SUN EXPECTED AND THIS IS WHERE THE MILDEST TEMPERATURES
WILL OCCUR (L60S). ELSEWHERE VALUES IN THE M-U 50S LOOKS
REASONABLE. NO PCPN IS EXPECTED OUTSIDE SOME PATCHY DRIZZLE
POSSIBLE ABOVE 2 KFT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 356 AM EDT TUESDAY...VARIABLE CLOUD COVER THEN PERSISTS
ACROSS THE REGION TONIGHT AS LOW TO MID LEVEL SOUTHERLY FLOW
SLOWLY INCREASES ACROSS THE REGION IN ADVANCE OF A DIGGING
SHORTWAVE TROUGH SWINGING INTO THE GREAT LAKES. LOW TEMPERATURES
A TAD MILDER GIVEN AT LEAST SOME TURBULENT MIXING PROCESSES JUST
OFF THE DECK...MAINLY 35-40 MTNS AND L-M 40S CHAMPLAIN/ST
LAWRENCE VALLEYS.
CHANGEABLE CONDITIONS TO THEN OCCUR DURING WEDNESDAY INTO
WEDNESDAY NIGHT AS A STRONG UPPER SHORTWAVE TROUGH AND ATTENDANT
SFC FRONT PUSH INTO THE AREA. MODELS HAVE TRENDED JUST A TAD
SLOWER WITH THIS FEATURE OVER THE PAST 24 HOURS SUCH THAT THE
FIRST HALF OF THE DAY ON WEDNESDAY SHOULD BE HALFWAY DECENT
DESPITE SOME CONTINUED PESKY LOW LEVEL CLOUD COVER. TEMPERATURES
WILL CLIMB INTO THE 55 TO 65 RANGE UNDER LIGHT TO MODEST
SOUTHERLY WINDS. BY LATER IN THE AFTERNOON AND INTO THE
EVENING...SHORTWAVE SWINGS INTO THE REGION WITH FAIRLY ROBUST
UPPER DYNAMICAL SUPPORT AND GOOD PVA/MOISTURE ADVECTION. THUS
WILL CONTINUE WITH PRIOR FCSTS IDEA OF HIGH CHC TO LIKELY POPS
(50/60%) DURING A SIX HOUR WINDOW FROM EARLY EVENING TO MIDNIGHT
OR SO. PCPN TENDS TO TAPER OFF AND TREND MORE OROGRAPHIC LATER AT
NIGHT AS POST-FRONTAL FLOW TURNS WESTERLY UNDER MODEST COLD AIR
ADVECTION. COULD ONCE AGAIN SEE SOME TAIL-END FLURRY/SHSN
ACTIVITY AT THE SUMMIT LEVEL OVERNIGHT AS PCPN ENDS...BUT THIS
SHOULD BE LIGHT. LOWS MAINLY IN THE 35 TO 40 RANGE.
SHORTWAVE RIDGING THEN SKIRTS ACROSS THE AREA BY THURSDAY WITH A
GOOD SHOT AT A FEW HOURS OF SUNSHINE THROUGH THE FIRST HALF OF
THE DAY. NEXT SHORTWAVE WILL QUICKLY APPROACH HOWEVER BY LATER IN
THE AFTERNOON WITH A RENEWED THREAT OF SHOWER ACTIVITY TOWARD
DAY`S END AS HIGHS TREND A TAD COOLER INTO THE 45 TO 55 RANGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 403 AM EDT TUESDAY...LARGE HIGH PRESSURE RIDGE WILL SINK
SOUTH TOWARDS THE CAROLINAS...ALLOWING A SHORTWAVE TO TRAVERSE
JUST NORTH OF THE NORTH COUNTRY...PRODUCING RAIN SHOWERS THURSDAY
NIGHT...LINGERING INTO FRIDAY. HIGH PRESSURE WILL BUILD IN BEHIND
THIS SHORTWAVE LATE FRIDAY INTO THE FIRST HALF OF THE WEEKEND.
FOR THE SECOND HALF OF THE WEEKEND...A CLOSED LOW PRESSURE SYSTEM
WILL APPROACH FROM THE WESTERN GREAT LAKES REGION...WITH A WARM
FRONT EXTENDING EASTWARD AHEAD OF THE LOW. THIS WARM FRONT WILL
BRING ANOTHER CHANCE FOR RAIN SHOWERS LATE SATURDAY INTO
SUNDAY...ALONG WITH WARMING TEMPERATURES INTO THE 60S.
THE CUTOFF LOW WILL MOVE NORTHEASTWARD TOWARD THE ST LAWRENCE
VALLEY DELTA...SO THE ASSOCIATED PRECIP WILL HAVE THE GREATEST
IMPACT ON OUR NORTHERN ZONES THROUGH LATE SUNDAY/EARLY MONDAY.
SUNDAY INTO SUNDAY NIGHT WILL EXPERIENCE SOME GUSTY CONDITIONS AS
THE PRESSURE GRADIENT INCREASES AT THE SFC...AND A JET AT 925MB
MOVES OVER THE WESTERN ST LAWRENCE VALLEY.
DRYER CONDITIONS EXPECTED ON MONDAY AS WEAK HIGH PRESSURE BRIEFLY
BUILDS IN AT THE SFC...AHEAD OF THE NEXT SHORTWAVE FEATURE
APPROACHING FROM CENTRAL SOUTHERN CANADA.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...ISOLATED AREAS OF IFR BR/FG WILL BE SLOW
TO BURN OFF THIS MORNING AS LOW LEVEL MOISTURE CONTINUES TO
SLOWLY EDGE NORTHWARD INTO THE NORTH COUNTRY. WITH THIS AREA OF
MOISTURE...MID AND LOW LEVEL CLOUDS WILL AFFECT ALL TAF SITES BY
LATE MORNING TO EARLY AFTERNOON. EXPECT VFR CIGS AND VSBYS TO
PERSIST THROUGHOUT THE DAY. AS EVENING APPROACHES...KMPV AND KRUT
CIGS WILL LOWER TO MVFR WITH BR/FG DEVELOPING AFTER MIDNIGHT.
WINDS WILL GENERALLY BE LIGHT...INCREASING OUT OF THE S-SE AT
5-10KTS THIS AFTERNOON. WIND SPEEDS WILL DECREASE TO LIGHT TO
CALM CONDITIONS TUESDAY NIGHT.
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...
12Z WEDNESDAY THROUGH 18Z WEDNESDAY...WEAK HIGH PRESSURE RIDGING
WILL BE OVERSHADOWED BY LOW LEVEL MOISTURE...KEEPING VFR TO MVFR
CIGS OVER THE REGION IN SE FLOW.
18Z WEDNESDAY THROUGH 12Z THURSDAY...A COLD FRONT WILL MOVE INTO
THE REGION ON WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT WITH
SCATTERED SHOWERS ALONG WITH SOME AREAS OF MVFR.
12Z THURSDAY THROUGH 00Z FRIDAY...MAINLY VFR AS A RIDGE OF HIGH
PRESSURE WILL BE OVER THE REGION.
00Z FRIDAY THROUGH 18Z FRIDAY...TRENDING BKN/OVC VFR WITH SOME
MVFR IN SCATTERED SHOWERS WITH COLD FRONTAL PASSAGE.
18Z FRIDAY THROUGH 00Z SUNDAY...TRENDING VFR AS A RIDGE OF HIGH
PRESSURE BUILDS INTO THE REGION.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/TABER
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS TULSA OK
933 PM CDT WED OCT 10 2012
...UPDATE...
.DISCUSSION...
ELEVATED MOISTURE RETURN IS UNDERWAY THIS EVENING EVIDENT WITH
EXPANDING STRATUS DECK WHILE ELEVATED WARM FRONTAL ZONE WORKS
NORTHWARD PER AREA 88D VWP DATA. 00Z KOUN/KSGF SOUNDINGS SAMPLE
BOTH THE MOISTURE LAYER /KOUN/ AND THE EDGE OF THE WEAKER CAPPING
ALOFT /KSGF/. THIS MOIST LAYER HEIGHT ALIGNS WELL WITH KSRX VWP
FRONTAL DEPTH AND SUPPORTS SHORT TERM MODEL SOLUTIONS OF
GENERATING LIGHT PRECIP LATER TONIGHT AS MOISTURE SPREADS
EASTWARD. LATEST LOCAL WRF / HRRR RUNS FAVOR E/SE AREAS OF THE
FORECAST AREA FOR BULK OF LATE NIGHT PRECIP WITH INSTABILITY IN
PLACE TO WARRANT A FEW THUNDERSTORMS. HRRR LIGHTNING FORECASTS
ALSO SUPPORT THIS TREND WITH ANY THUNDERSTORM LIKELY DEVELOPING
MORE TOWARD SUNRISE AND AFTERWARD. HAIL WILL BE POSSIBLE WITH MOST
ANY SUSTAINED UPDRAFT THOUGH THE RISK OF SEVERE CRITERIA HAIL
LOOKS VERY LOW THROUGH THE REMAINDER OF TONIGHT. UPDATED FORECAST
WILL ADJUST WX GRIDS AND SKY COVER TRENDS. FAR NE OK HAS COOLED
QUICKLY PRIOR TO LOW CLOUD ARRIVAL..BUT THIS TREND SHOULD STEADY
SOON. TEMPS ADJUSTMENTS WERE SLIGHTLY DOWN FOR FAR NE OK AND
SLIGHTLY UPWARD ELSEWHERE GIVEN THICK CLOUD BLANKET.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 56 76 64 77 / 10 20 70 60
FSM 55 75 62 81 / 20 20 60 50
MLC 58 79 65 82 / 20 20 50 40
BVO 44 76 62 75 / 10 20 70 60
FYV 51 71 60 76 / 20 20 70 50
BYV 49 70 58 72 / 20 30 80 50
MKO 55 76 64 79 / 20 20 70 50
MIO 48 72 59 74 / 20 20 80 50
F10 58 80 65 80 / 10 20 50 50
HHW 60 80 66 85 / 20 20 10 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...07
AREA FORECAST DISCUSSION
NWS NORMAN OK
851 PM CDT WED OCT 10 2012
.UPDATE...
ONLY MINOR TWEAKS TO TONIGHTS GRIDS. STILL APPEARS THERE IS AN
OUTSIDE CHANCE FOR SOME LATE NIGHT SHOWERS OR PERHAPS A
THUNDERSTORM. OTHERWISE MILD NIGHT AS CLOUD COVER OVERSPREADS THE
AREA AND LOW LEVEL MOISTURE BEGINS TO INCREASE WITH THE RETURN OF
SOUTH WINDS. NO UPDATES AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 631 PM CDT WED OCT 10 2012/
DISCUSSION...
PLEASE SEE THE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
MOSTLY MVFR DUE TO LOW CIGS WILL PREVAIL THROUGH AT LEAST THE
OVERNIGHT HOURS FOR A MAJORITY OF THE TERMINALS. THE WINDS WILL
BEGIN TO SHIFT FROM THE SOUTH LATE TONIGHT AND EARLY TOMORROW
MORNING...INCREASING TO AROUND 15 TO 20KT BY TOMORROW AFTERNOON.
VFR MAY RETURN AT PNC..WWR..AND GAG AROUND 12-18Z...BUT THE OTHER
TERMINALS MAY NOT EXPERIENCE THESE IMPROVED CONDITIONS UNTIL AFTER
18Z.
PREV DISCUSSION... /ISSUED 335 PM CDT WED OCT 10 2012/
DISCUSSION...
STRATUS CONTINUES TO SPREAD NORTH ACROSS THE AREA AND EXPECT
OVERCAST SKIES AREAWIDE BY MID-LATE EVENING. HRRR HAS SOME SIGNAL
THAT CLEARING OVER CENTRAL TEXAS NOW MAY SPREAD INTO NORTH TEXAS
ZONES LATE TONIGHT... BUT MOST SIGNAL IS FOR STRATUS PERSISTANCE
OR REDEVELOPMENT WITH THIS LOW-LEVEL MOISTURE ADVECTION... SO WILL
JUST KEEP THE OVERCAST SKIES THROUGHOUT. MAY SEE SOME LIGHT
SHOWERS DEVELOP OVERNIGHT AS LOW-LEVEL MOISTURE INCREASES.
STORM CHANCES INCREASE THURSDAY NIGHT AND PERSIST THROUGH AT LEAST
SATURDAY AS EXPECTED WITH /A/ THE ARRIVAL OF A COLD FRONT MOVING
SOUTH THROUGH THE CENTRAL PLAINS IN RESPONSE TO A STORM SYSTEM
SWINGING THROUGH THE GREAT LAKES.. AND /B/ THE STORM SYSTEM
CURRENTLY ON THE SOUTHERN CALIFORNIA COAST MOVING TOWARD THE
PLAINS. NO REAL SIGNIFICANT CHANGE IN THE EXPECTATIONS FROM THE
PREVIOUS FORECAST WITH THIS SYSTEM... SO HAVE ONLY MADE MINOR
CHANGES TO THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 55 80 65 83 / 20 20 40 50
HOBART OK 52 80 64 81 / 20 20 40 40
WICHITA FALLS TX 58 84 67 85 / 20 20 20 20
GAGE OK 50 84 58 75 / 10 20 40 50
PONCA CITY OK 54 81 61 76 / 20 20 60 50
DURANT OK 58 82 65 85 / 20 20 20 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
30/03
AREA FORECAST DISCUSSION
NWS NORMAN OK
631 PM CDT WED OCT 10 2012
.DISCUSSION...
PLEASE SEE THE 00Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
MOSTLY MVFR DUE TO LOW CIGS WILL PREVAIL THROUGH AT LEAST THE
OVERNIGHT HOURS FOR A MAJORITY OF THE TERMINALS. THE WINDS WILL
BEGIN TO SHIFT FROM THE SOUTH LATE TONIGHT AND EARLY TOMORROW
MORNING...INCREASING TO AROUND 15 TO 20KT BY TOMORROW AFTERNOON.
VFR MAY RETURN AT PNC..WWR..AND GAG AROUND 12-18Z...BUT THE OTHER
TERMINALS MAY NOT EXPERIENCE THESE IMPROVED CONDITIONS UNTIL AFTER
18Z.
&&
.PREV DISCUSSION... /ISSUED 335 PM CDT WED OCT 10 2012/
DISCUSSION...
STRATUS CONTINUES TO SPREAD NORTH ACROSS THE AREA AND EXPECT
OVERCAST SKIES AREAWIDE BY MID-LATE EVENING. HRRR HAS SOME SIGNAL
THAT CLEARING OVER CENTRAL TEXAS NOW MAY SPREAD INTO NORTH TEXAS
ZONES LATE TONIGHT... BUT MOST SIGNAL IS FOR STRATUS PERSISTANCE
OR REDEVELOPMENT WITH THIS LOW-LEVEL MOISTURE ADVECTION... SO WILL
JUST KEEP THE OVERCAST SKIES THROUGHOUT. MAY SEE SOME LIGHT
SHOWERS DEVELOP OVERNIGHT AS LOW-LEVEL MOISTURE INCREASES.
STORM CHANCES INCREASE THURSDAY NIGHT AND PERSIST THROUGH AT LEAST
SATURDAY AS EXPECTED WITH /A/ THE ARRIVAL OF A COLD FRONT MOVING
SOUTH THROUGH THE CENTRAL PLAINS IN RESPONSE TO A STORM SYSTEM
SWINGING THROUGH THE GREAT LAKES.. AND /B/ THE STORM SYSTEM
CURRENTLY ON THE SOUTHERN CALIFORNIA COAST MOVING TOWARD THE
PLAINS. NO REAL SIGNIFICANT CHANGE IN THE EXPECTATIONS FROM THE
PREVIOUS FORECAST WITH THIS SYSTEM... SO HAVE ONLY MADE MINOR
CHANGES TO THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 55 80 65 83 / 20 20 40 50
HOBART OK 52 80 64 81 / 20 20 40 40
WICHITA FALLS TX 58 84 67 85 / 20 20 20 20
GAGE OK 50 84 58 75 / 10 20 40 50
PONCA CITY OK 54 81 61 76 / 20 20 60 50
DURANT OK 58 82 65 85 / 20 20 20 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
30/03/03
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
925 PM CDT WED OCT 10 2012
.UPDATE...
SEE EVENING UPDATE.
&&
.DISCUSSION...
RELATIVELY DEEP MOISTURE COUPLED WITH A WEAK 850 TROUGH PRODUCED
SCATTERED SHRA/TSRA THIS AFTN AND EVENING. AM EXPECTING SHRA/TSRA
TO END IN THE NEXT 30 MINUTES OR SO. A FEW OF THE STORMS PRODUCED
SOME HEFTY (3 TO 4 INCHES) RAINFALL TOTALS OVER THE SW ZONES THIS
EVENING. GLS IS ALREADY BELOW FCST VALUES SO WILL TWEAK MIN TEMP
GRIDS A BIT BUT OVERALL FCST FOR TONIGHT IS ON TRACK. T/TD SPREAD
IS NARROWING SO FEEL PATCHY FOG WILL AGAIN BE POSSIBLE. 43
&&
.PREV DISCUSSION... /ISSUED 650 PM CDT WED OCT 10 2012/
DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
A STATIONARY FRONT STRETCHED ACROSS THE NORTHERN PART OF SE TX
EARLY THIS EVENING...WHILE THE 22Z RUC MODEL SHOWED THAT A
SHORTWAVE TROUGH WAS MOVING OVER THE AREA. ISOLATED SHOWERS AND
THUNDERSTORMS THAT DEVELOPED EARLIER...MOST OUTSIDE OF THE
TERMINAL FORECAST SITES AND VICINITY AREAS...SHOULD DIMINISH BY
03Z. HOWEVER..WILL DO FREQUENT CHECKS FOR ANY NEEDED UPDATES.
OTHERWISE...THERE IS GOOD CONFIDENCE IN THE VFR CONDITIONS
BECOMING MVFR BETWEEN 06Z AND 11Z. DIMINISHING WINDS IN THE
BOUNDARY LAYER AS WELL AS A DEVELOPING LOW-LEVEL INVERSION SHOULD
AID IN DEVELOPMENT OF A CLOUD DECK...WHILE FOG IS POSSIBLE
ESPECIALLY AT KLBX. EXPECT THESE CONDITIONS TO IMPROVE BACK TO
VFR BY 15Z.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 70 89 69 89 69 / 10 10 10 0 10
HOUSTON (IAH) 71 89 70 88 71 / 10 10 10 0 10
GALVESTON (GLS) 76 84 75 84 77 / 10 10 10 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
650 PM CDT WED OCT 10 2012
.DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
A STATIONARY FRONT STRETCHED ACROSS THE NORTHERN PART OF SE TX
EARLY THIS EVENING...WHILE THE 22Z RUC MODEL SHOWED THAT A
SHORTWAVE TROUGH WAS MOVING OVER THE AREA. ISOLATED SHOWERS AND
THUNDERSTORMS THAT DEVELOPED EARLIER...MOST OUTSIDE OF THE
TERMINAL FORECAST SITES AND VICINITY AREAS...SHOULD DIMINISH BY
03Z. HOWEVER..WILL DO FREQUENT CHECKS FOR ANY NEEDED UPDATES.
OTHERWISE...THERE IS GOOD CONFIDENCE IN THE VFR CONDITIONS
BECOMING MVFR BETWEEN 06Z AND 11Z. DIMINISHING WINDS IN THE
BOUNDARY LAYER AS WELL AS A DEVELOPING LOW-LEVEL INVERSION SHOULD
AID IN DEVELOPMENT OF A CLOUD DECK...WHILE FOG IS POSSIBLE
ESPECIALLY AT KLBX. EXPECT THESE CONDITIONS TO IMPROVE BACK TO
VFR BY 15Z.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 69 89 69 89 69 / 10 10 10 0 10
HOUSTON (IAH) 68 89 70 88 71 / 10 10 10 0 10
GALVESTON (GLS) 77 84 75 84 77 / 10 10 10 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 PM CDT MON OCT 8 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
235 PM CDT MON OCT 8 2012
MAIN FORECAST CONCERN IS ON RAIN CHANCES FOR TONIGHT AND TUESDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE NORTHEAST PACIFIC AND TROUGHING ACROSS
CENTRAL AND EASTERN CANADA. WITHIN THIS TROUGH...THERE ARE TWO
SHORTWAVE TROUGHS OF NOTE. THE FIRST IS OVER NORTHERN MINNESOTA...
WITH AN ASSOCIATED 998MB SURFACE LOW OVER NORTHWEST MINNESOTA. DPVA
AHEAD OF THE SHORTWAVE IN CONJUNCTION WITH WARM ADVECTION/ISENTROPIC
LIFT HAS SUPPORTED A LARGE AREA OF ALTOSTRATUS ACROSS MINNESOTA INTO
THE NORTHWEST HALF OF WISCONSIN. DRY LOW LEVEL AIR SEEN ON THE 12Z
MPX SOUNDING AS WELL AS SURFACE RELATIVE HUMIDITIES IN THE 25-40
PERCENT RANGE HAS KEPT THE SOUTHERN MINNESOTA DRY DESPITE LIGHT
RETURNS ON RADAR. BREEZY SOUTHWEST WINDS ARE ALSO OCCURRING ACROSS
THE FORECAST AREA AS A RESULT OF A TIGHT PRESSURE GRADIENT. THESE
SOUTHWEST WINDS ARE ADVECTING WARMER AIR INTO THE AREA...NOTED BY
850MB TEMPS PER THE RAP THAT HAVE CLIMBED TO 4-6C AFTER STARTING OFF
AT 1-3C ACCORDING TO 12Z RAOBS. COLD FRONT ASSOCIATED WITH THE LOW
PRESSURE AREA APPROACHING SIOUX FALLS SOUTH DAKOTA. THE NEXT
SHORTWAVE TROUGH OF NOTE...WHICH LOOKS QUITE POTENT IN WATER
VAPOR...IS IN SOUTHERN SASKATCHEWAN. A 100-120 KT JET NEAR 250MB WAS
LOCATED ON THE WEST/SOUTHWEST SIDE OF THIS SHORTWAVE.
TONIGHT AND TUESDAY...THE POTENT SHORTWAVE IN SASKATCHEWAN MODELS
SHOW DROPPING DOWN INTO THE DAKOTAS TONIGHT...THEN INTENSIFYING AND
TURNING NEUTRAL TILT AS IT CROSSES MINNESOTA INTO FAR WESTERN
WISCONSIN DURING THE DAY TUESDAY. AS THIS SHORTWAVE APPROACHES
TONIGHT...IT HELPS TO SLOW DOWN THE CURRENT EASTWARD PROGRESS OF THE
COLD FRONT NEAR SIOUX FALLS. IN FACT...BY 12Z...THE FRONT MAY JUST
BE GETTING INTO SOUTHEAST MN. AS SUCH...A MILD NIGHT COMPARED TO
WHAT HAS BEEN SEEN RECENTLY IS ON TAP TONIGHT...AIDED BY A
CONTINUING SOUTHWEST BREEZE AND PLENTY OF CLOUDS. THEREFORE...STAYED
ON THE WARM SIDE OF GUIDANCE. PRECIPITATION CHANCES TONIGHT ARE VERY
QUESTIONABLE BECAUSE OF THE SLOW FRONTAL PROGRESS. WHEN HEADING INTO
THE COLD SEASON...MOST PRECIPITATION FALLS POST-COLD FRONTAL BECAUSE
OF COLD AIR UNDERCUTTING THE WARM AIR. IN THIS CASE...THE
FRONTOGENESIS FORCING WHICH DOES STRENGTHEN THROUGH THE NIGHT ENDS
UP STAYING MOSTLY WEST OF THE AREA. AS SUCH...HAVE CONFINED THE
PRECIPITATION CHANCES TO MOSTLY LATE TONIGHT AND OVER THE NORTHWEST
1/3 OF THE AREA. IN ADDITION...HAVE KEPT THE CHANCES IN THE 20-40
RANGE AS CONFIDENCE IS LOW IN GETTING THE AIR SATURATED AND THE
FRONT INTO THE AREA. NOW THINGS ARE A LOT DIFFERENT ON TUESDAY. THE
FRONTOGENESIS ZONE ON TUESDAY IS PROGGED TO STRENGTHEN
DRAMATICALLY...CAUSED BY THE APPROACHING SHORTWAVE. CROSS-SECTIONS
SHOW A NICE FRONTOLYSIS/FRONTOGENESIS COUPLET WHICH YIELDS STRONG
UPWARD VERTICAL MOTION. SO ANTICIPATING THAT AS THE SHORTWAVE MOVES
IN AND PUSHES THE FRONT EAST...SHOULD SEE A BAND OF RAIN BEHIND IT.
IN FACT...MOST OF THE AREA LOOKS TO GET RAIN NOW FOR TUESDAY...
THOUGH NORTHWEST SECTIONS SHOULD DRY OUT IN THE AFTERNOON AS THE
FRONTOGENESIS FORCING HEADS EAST. WITH THE FRONT AND RAIN MOVING
THROUGH...A NON-DIURNAL TREND IS REQUIRED. PLUS...850MB TEMPS FALL
FROM 2-6C AT 12Z TO 0 TO -2C AT 00Z. HIGHS WILL TOP OUT IN THE UPPER
40S TO MIDDLE 50S AT BEST...AND FOR SOME LOCATIONS THIS MAY BE A
MORNING HIGH.
TUESDAY NIGHT AND WEDNESDAY...THE FORECAST AREA IS PROGGED TO SIT
UNDER UPPER LEVEL TROUGHING FOR MUCH OF TUESDAY NIGHT...IN THE WAKE
OF THE POTENT SHORTWAVE PUSHING EAST OF THE AREA DURING THE EVENING.
NORTHERLY LOW LEVEL FLOW UNDER THE UPPER TROUGH WILL HELP DRIVE
850MB TEMPS FURTHER DOWN...REACHING -4 TO -7C BY 12Z WEDNESDAY.
ACCOMPANYING THE COLDER AIR SHOULD BE A LOW STRATUS DECK...
PARTICULARLY ACROSS WISCONSIN. SO AFTER PERHAPS A BRIEF PERIOD OF
CLEARING IN THE EVENING IN THE WAKE OF THE PRECIPITATION...EXPECT
CLOUDS TO INCREASE. THE COMBINATION OF THESE CLOUDS AND A DECENT
NORTHERLY BREEZE WILL HELP TO KEEP TEMPERATURES FROM BOTTOMING OUT
TO MUCH. HAVE LEANED TOWARDS THE WARMER SIDE OF GUIDANCE AS A RESULT
WITH LOWS IN THE UPPER 20S TO LOWER 30S. THIS STRATUS DECK WILL
DISSIPATE ON WEDNESDAY AS A SURFACE HIGH PRESSURE RIDGE AXIS SLIDES
EAST ACROSS THE AREA. IN FACT...BY 00Z THURSDAY...STRENGTHENING
SOUTHWEST BREEZES ARE EXPECTED AHEAD OF YET ANOTHER POTENT SHORTWAVE
DROPPING DOWN INTO SOUTH CENTRAL CANADA. THESE BREEZES WILL HELP
ADVECT WARMER AIR INTO THE AREA...WITH 850MB TEMPS CLIMBING TO 0 TO
-3C BY 00Z. PLENTY OF SUN AND DRY AIR SHOULD ALLOW FOR PLENTY OF
MIXING...BUT GIVEN THE COOL 850MB TEMPS...AT BEST HIGHS MAY REACH
THE MID 50S AND THAT IS IN FAR SOUTHWESTERN PORTIONS OF THE FORECAST
AREA WHERE THE WARMEST AIR COMES IN LATE.
WEDNESDAY NIGHT AND THURSDAY...THE NEXT POTENT SHORTWAVE THAT
DROPPED DOWN INTO SOUTH CENTRAL CANADA ON WEDNESDAY IS FORECAST TO
HEAD TO THE EAST...VERSUS DIG DOWN TOWARDS THE FORECAST AREA LIKE
THE PAST COUPLE HAVE DONE. AS SUCH...ALL FORCING AND EXPECTED
PRECIPITATION WITH IT WILL STAY WELL NORTH OF THE FORECAST AREA.
HOWEVER...A COLD FRONT IS STILL SLATED TO COME THROUGH. SOME TIMING
DIFFERENCES ON THE SPEED...WITH THE 08.12Z NAM THE SLOWEST NOT
SHOWING FULL PASSAGE UNTIL THURSDAY EVENING WHILE THE 08.12Z
GFS/ECMWF/CANADIAN/UKMET SUGGESTING MAINLY DURING THURSDAY MORNING.
WILL FOLLOW THE MAJORITY GROUP AT THIS TIME AND CONSIDER THE NAM AN
OUTLIER. NO MATTER WHAT MODEL FOLLOWED...IN THE COLD FRONT
WAKE...YET ANOTHER COLD CANADIAN HIGH PRESSURE AREA IS PROGGED TO
DROP DOWN INTO NORTH DAKOTA. AS SUCH...AFTER 850MB TEMPS WARM UP TO
A CONSENSUS 4-8C AT 12Z THURSDAY AHEAD OF THE FRONT...THEY FALL BACK
DOWN TO 0 TO -4C. THIS COLD ADVECTION MAY BE ENOUGH TO PROVIDE A
LITTLE FALL TO TEMPERATURES IN THE AFTERNOON. REGARDING
TEMPERATURES...LEANED CLOSER TO A BLEND OF GUIDANCE FROM THE
MAJORITY GROUP...YIELDING LOWS IN THE MID 30S TO LOW 40S AND HIGHS
IN THE 50S TO LOWER 60S. WARMEST READINGS ON THURSDAY EXPECTED IN
THE FAR SOUTHEAST WITH THE LONGEST PERIOD AHEAD OF THE FRONT AND
POTENTIAL FOR MOST SUN.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
235 PM CDT MON OCT 8 2012
MAIN FORECAST CONCERN IS ON THE EXPECTED WIDESPREAD RAINFALL
CENTERED AROUND SATURDAY
08.12Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES REMAIN IN GOOD AGREEMENT
AMONGST EACH OTHER AND PAST RUNS SHOWING A PATTERN CHANGE HERE LATE
THIS WEEK. CURRENT UPPER LOW OFF THE COAST OF CALIFORNIA...WHICH
WILL BE DROPPING INTO THE DESERT SOUTHWEST BY FRIDAY MORNING...
MODELS PROG TO LIFT INTO NEBRASKA AND KANSAS ON SATURDAY. A LOW
PRESSURE SYSTEM DEEPENS AHEAD OF THIS UPPER LOW...RESULTING IN
STRONG LOW LEVEL MOISTURE TRANSPORT OUT OF THE GULF OF MEXICO
NORTHWARD INTO THE FORECAST AREA. SO AFTER WHAT WILL BE A DRY AND
COOL THURSDAY NIGHT AND FRIDAY ASSOCIATED WITH CANADIAN HIGH
PRESSURE MOVING ACROSS...EXPECT WARMING WITH PRECIPITATION
EVENTUALLY SPREADING IN FRIDAY NIGHT AND SATURDAY. SATURDAY STILL
LOOKS TO BE THE BEST DAY FOR PRECIPITATION WITH EXPECTED COMBINATION
OF ISENTROPIC LIFT...UPPER JET FORCING AND DPVA. SOME DIFFERENCES DO
EXIST ON SATURDAY AND PARTICULARLY SATURDAY NIGHT AND SUNDAY
REGARDING THE TRACK OF THE UPPER AND SURFACE LOWS. THE 08.12Z
CANADIAN AND A FEW OF THE GFS ENSEMBLE MEMBERS HOLD THE MAJORITY OF
THE SYSTEM BACK OVER THE CENTRAL PLAINS...WHEREAS MOST OTHER MODELS
CONTINUE THE IDEA OF THE PAST FEW DAYS OF EJECTING IT UP TOWARDS THE
GREAT LAKES. HOWEVER...THERE HAS BEEN A TREND IN THE LATTER GROUP TO
ALSO LIFT THE SYSTEM MORE TO THE NORTHWEST. AS A RESULT...FOR LATE
SATURDAY AND SATURDAY EVENING...OUR WHOLE FORECAST AREA ENDS UP IN
THE WARM SECTOR. ALTHOUGH 0-6KM SHEAR IS PLENTIFUL AHEAD OF THE COLD
FRONT...NO FEAR OF SEVERE CONVECTION AS THE 0-3KM MUCAPE FOR
SATURDAY AND SATURDAY NIGHT IS GENERALLY LESS THAN 500 J/KG. FOR THE
FORECAST...HAVE LEANED TOWARDS THE LATTER GROUP...BUT EITHER
SCENARIO YIELDS WIDESPREAD RAINFALL FOR THE FORECAST AREA SATURDAY
INTO MUCH OF SATURDAY NIGHT. THUNDER CHANCES REMAIN NECESSARY DUE TO
THE EXPECTED MUCAPE. EXACT QPF AMOUNTS UNCERTAIN...ESPECIALLY WITH
THE TREND OF THE SYSTEM NOW MORE THE NORTHWEST WHICH WOULD LIKELY
BE LESS THAN IF THE SYSTEM WAS GOING SLIGHTLY TO OUR SOUTH.
IN THE WAKE OF THE UPPER LOW...FORECAST BECOMES A LITTLE MORE
UNCERTAIN FOR SUNDAY INTO MONDAY. PATTERN FROM THE EAST PACIFIC
ACROSS NORTH AMERICA APPEARS TO HAVE FAST FLOW ASSOCIATED WITH IT.
THERE ARE SUGGESTIONS BY THE 08.12Z GFS AND 08.00Z ECMWF OF A
SHORTWAVE TROUGH COMING OUT OF THE PACIFIC NORTHWEST ON SATURDAY
WHICH DIGS INTO THE CENTRAL PLAINS ON MONDAY. GFS ENSEMBLES SHOW A
LOT OF SPREAD...THOUGH...WITH SOME NOT HAVING THIS TROUGH AT ALL AND
ACTUALLY SHOWING A RIDGE. NEW 08.12Z ECMWF KEEPS THE SHORTWAVE
MOVING EAST WITH HINTS OF RIDGING COMING AT THE FORECAST AREA LATE
MONDAY. AS SUCH...HAVE FOLLOWED A CONSENSUS APPROACH FOR THE SUNDAY
THROUGH MONDAY FORECAST. NET RESULT IS TO HAVE SOME LOW
PRECIPITATION CHANCES ON SUNDAY WITH ANY LINGERING PRECIPITATION
FROM THE UPPER LOW...THEN SOME LOW PRECIPITATION CHANCES ON
MONDAY WITH THE POTENTIAL OF THE SHORTWAVE TROUGH DROPPING IN.
TEMPERATURES AT LEAST LOOK CLOSER TO NORMAL THANKS TO THE PACIFIC
FLOW OF AIR.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1150 PM CDT MON OCT 8 2012
A BAND OF SPRINKLES AND LIGHT RAIN WERE FOUND ACROSS SOUTHEAST
MINNESOTA AND INTO PORTIONS OF WESTERN WISCONSIN LATE THIS
EVENING. CEILINGS REMAINED IN THE VFR CATEGORY WITH BASES BETWEEN
050-070K FEET. THIS ALL AHEAD OF THE SURFACE TROUGH NOW MAKING ITS
WAY INTO SOUTHEAST MINNESOTA. BUFKIT SOUNDINGS INDICATE LOW LAYERS
TO SATURATE THROUGH THE OVERNIGHT HOURS AND DO EXPECT MVFR
CEILINGS TO DEVELOP AT BOTH TAF SITES BETWEEN 12Z-14Z. MAIN
SHORTWAVE DROPS THROUGH THE FLOW TUESDAY PUSHING THE SURFACE
TROUGH THROUGH THE AREA. TIME HEIGHT CROSS SECTIONS SHOW RATHER
DEEP FRONTOGENETIC FORCING AND WOULD EXPECT THE PERIODS OF RAIN TO
CONTINUE INTO THE AFTERNOON HOURS. TROUGH LOOKS TO CLEAR THE AREA
LATER IN THE AFTERNOON WITH SOME DRIER AIR WORKING IN. HOWEVER...A
BAND OF STRATUS MAY AFFECT THE KLSE TAF SITES IN ITS WAKE...BUT
THE NAM RELATIVE HUMIDITY PROGS SHOWS IT JUST BRUSHING KRST. THUS
WILL SCATTERED OUT THE CLOUDS AT KRST...BUT KEEP A BROKEN VFR
CEILING AT KLSE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
702 PM CDT MON OCT 8 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...JLR
AREA FORECAST DISCUSSION
NWS ALBANY NY
135 AM EDT THU OCT 11 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND THIS EVENING WITH SOME SCATTERED SHOWERS
PERSISTING NORTHWEST OF THE CAPITAL REGION. HIGH PRESSURE WILL
BRIEFLY BUILD IN FROM THE OHIO VALLEY WITH COOL AND BRISK CONDITIONS
TOMORROW. ANOTHER COLD FRONT WILL APPROACH FROM THE EASTERN GREAT
LAKES REGION THURSDAY NIGHT WITH A CHANCE OF SHOWERS ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AT 1:30 AM EDT...LAKE EFFECT SHOWERS NOW OVER MUCH OF THE ADIRONDACK
PARK...SOME OF WHICH HAVE WORKED NORTH OF GLENS FALLS INTO EVEN
NORTHERN WASHINGTON COUNTY. MOST IF NOT ALL PLACES WERE STILL ABOVE
FREEZING WITH MADIS INDICATING 37 DEGREES AT LONG LAKE. SOME OF THE
HIGHER ELEVATIONS PROBABLY SEEING SOME MIXING WITH WET SNOW FLAKES
OR GRAUPEL AT THIS TIME.
FINE TUNED THE PLUME IN OUR GRIDS BASED ON THE LATEST GUIDANCE AND
RADAR TRENDS. THE HRRR ACTUALLY BRINGS THE PLUME RIGHT INTO THE
CAPITAL DISTRICT BRIEFLY LATER OVERNIGHT. NOT SOLD ON THIS SOLUTION
SO WILL USE PERSISTENCE AT THIS TIME FRAME.
THE KVIE PROGRAM INDICATED THAT THE INLAND EXTENT NEVER EXCEEDS
ABOUT 75 MILES WHICH MEANS THE PLUME WOULD FALL SHORT OF THE CAPITAL
DISTRICT. AGAIN...FOR NOW WILL LEAVE IT OUT.
IT SHOULD BE COLD ENOUGH FOR ALL SNOW SHOWERS ACROSS THE ADIRONDACKS
BUT AT THIS TIME...WE BELIEVE ANY ACCUMULATIONS WOULD BE CONFINED TO
THE HIGHEST MOUNTAIN AREAS AND WE DID NOT INCLUDE ANY IN THE
GRIDS.
OVERNIGHT LOWS LOOK FINE FROM BEFORE AND WERE GENERALLY LEFT
ALONE.
A CHANNEL OF VERY COLD AIR WILL BE DIVING IN FROM THE NORTHWEST WITH
THE UPPER TROUGH SHOWING SIGNS OF BECOMING NEGATIVELY TILTED...AS
THE CLOSED EMBEDDED H500 CIRCULATION IN THE TROUGH MOVES OVER HUDSON
BAY. THE H500 TEMPS ARE CLOSE TO -30C OVER MI AND WI FROM THE 1200
UTC RAOB DATA. THIS CHILLY AIR ALOFT COUPLED WITH THE WARM LAKE
ONTARIO TEMPS IN THE 10-13C RANGE /FAVORABLE DELTA TEMPS FROM THE
SFC TO H700/ WILL KICK UP SOME LAKE EFFECT SHOWERS...WHICH WILL
LIKELY TRANSITION TO SOME SNOW SHOWERS OVER THE WRN DACKS. THE
BOUNDARY LAYER WILL TAKE ITS TIME TO COOL DOWN. THE LOW LEVEL WINDS
WILL CONTINUE TO VEER CLOSE TO A 270-280 DEG LOW-LEVEL TRAJECTORY.
THERE COULD BE A FEW RUMBLES OF THUNDER CLOSER TO LAKE SHORE...WHERE
BETTER LAKE INDUCED INSTABILITY IS OCCURRING. AGAIN..ANY SNOW
ACCUMULATIONS WILL BE VERY LIGHT ON THE ORDER OF A COATING TO A FEW
TENTHS OVER SOME ISOLD PORTIONS OF NRN HERKIMER AND NRN HAMILTON
COUNTIES...MAINLY OVER THE HIGHEST ELEVATIONS.
ELSEWHERE...PARTLY TO MOSTLY CLOUDY CONDITIONS WILL PERSIST AFTER
MIDNIGHT WITH BRISK CONDITIONS. THE COLD ADVECTION IN THE WAKE OF
THE BOUNDARY WILL ALLOW TEMPS TO FALL INTO THE 0 TO -5C RANGE
ACROSS THE FCST AREA. LOW TEMPS WILL GENERALLY BE IN THE U30S TO
L40S...EXCEPT FOR SOME LOWER TO M30S OVER THE SRN DACKS
REGION...AND SRN GREENS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
TOMORROW...THE LOW-LEVEL FLOW CONTINUES TO VEER TO MORE OF A W/NW
DIRECTION WITH SOME LAKE EFFECT RAIN SHOWERS CONTINUING OVER THE
WRN DACKS...W-CNTRL MOHAWK VALLEY...NRN CATSKILLS...AND SCHOHARIE
VALLEY. SFC HIGH PRESSURE WILL BE NUDGING IN FROM THE OHIO VALLEY.
IT WILL BE A BRISK AND COOL AFTERNOON WITH W/NW WINDS OF 10 TO 20
MPH WITH SOME GUSTS AROUND 30 MPH. THE BRISK CONDITIONS WILL BE
DUE TO GOOD MIXING...AND A STRONG SFC PRESSURE GRADIENT BETWEEN
THE SFC ANTICYCLONE TO THE SOUTH...AND LOW PRESSURE OVER THE
CANADIAN MARITIMES. MAX TEMPS WILL GENERALLY BE IN THE 50S /A FEW
ISOLD 60S TO THE SOUTH/ WITH SOME U40S OVER THE SRN GREENS...SRN
DACKS...AND ERN CATSKILLS.
THU NIGHT...THE VESTIGES OF THE LAKE EFFECT LIFT NORTHWARD ACROSS
THE DACKS...AS THE LOW TO MID LEVEL FLOW BACKS...AND BECOMES
ZONAL. SOME WARM ADVECTION RAIN OR EVEN LIGHT SNOW SHOWERS MAY
OCCUR OVER THE SRN DACKS AGAIN. CLOUDS WILL THICKEN AND LOWER OVER
THE REGION...AS THE NEXT SHORT-WAVE APPROACHES FROM ONTARIO AND
THE GREAT LAKES REGION. THE SFC COLD FRONT WITH THE SHORT-WAVE
TROUGH IS FASTER THIS SUITE OF SHORT-RANGE GUIDANCE...WITH A GOOD
CHANCE OF SHOWERS FROM THE I-90 CORRIDOR NORTH PRIOR TO 12Z/FRI.
LOWS WILL GENERALLY BE IN THE U30S TO L40S AGAIN...EXCEPT
NORTHWEST OF THE CAPITAL REGION WHERE SOME LOWER TO M30S WILL BE
POSSIBLE. TEMPS MAY ACTUALLY FALL EARLY AND RISE OVERNIGHT.
FRIDAY...THE COLD FRONT BLASTS THROUGH WITH SOME SCATTERED SHOWERS
MOVING ACROSS THE REGION. THE MOISTURE CONVERGENCE ISN/T TOO
IMPRESSIVE WITH THE FASTER TIMING OF THE BOUNDARY. THE THERMAL
GRADIENT IS IMPRESSIVE WITH H850 TEMPS FALLING TO -4C TO -8C FROM
SOUTH TO NORTH OVER THE REGION IN THE STRONG COLD AIR ADVECTION
REGIME. THE WINDS WILL INCREASE DURING THE AFTERNOON...AND THERE
COULD BE SOME UPSLOPE OR LAKE EFFECT RAIN/SNOW SHOWERS
BRIEFLY...BEFORE THE LOW LEVEL FLOW VEERS QUICKLY TO THE N/NW. MAX
TEMPS WILL BE TRICKY WITH HIGHS GENERALLY IN THE 50S IN THE
VALLEYS...AND LOWER 40S TO POSSIBLY 50F OVER THE HILLS AND MTNS.
FRI NIGHT...A COLD CANADIAN ANTICYCLONE BUILDS IN RAPIDLY OVER THE
NORTHEAST WITH CLEAR/MOSTLY CLEAR SKIES...AND LIGHT TO CALM WINDS.
IDEAL RADIATIONAL COOLING IS EXPECTED...AS TEMPS ARE EXPECTED TO
FALL BELOW 32F ACROSS THE ENTIRE FCST AREA. A WIDESPREAD FROST IS
ANTICIPATED AT THIS TIME. THERE COULD EVEN BE SOME TEENS OVER THE
SRN DACKS. MID AND U20S WILL BE COMMON IN MOST LOCATIONS. WE
CONTINUED THE MENTION OF A WIDESPREAD FREEZE IN THE HWO.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A CUT OFF LOW OVER THE SOUTHWESTERN UNITED STATES IS EXPECTED TO
OPEN AND MOVE NORTHEASTWARD. IT WILL WEAKEN AS HEADS INTO THE GREAT
LAKES REGION OVER THE WEEKEND. TO START OFF THE WEEKEND WILL HAVE
SURFACE RIDGING OVER THE REGION WHICH WILL SHIFT EASTWARD AND
OFFSHORE BY SATURDAY EVENING. ALOFT WILL HAVE SOME RIDGING BEING
INDUCED AHEAD OF APPROACHING LOW PRESSURE SYSTEM. AT THIS TIME
EXPECTING DRY WEATHER ON SATURDAY WITH CHANCES FOR SHOWERS
INCREASING SATURDAY NIGHT ESPECIALLY LATE AS THE LOW PRESSURE SYSTEM
APPROACHES. THIS SYSTEM IS EXPECTED TO IMPACT THE REGION INTO
MONDAY. MODEL GUIDANCE IS IN AGREEMENT THAT THE SURFACE LOW WILL
PASS TO OUR NORTH AND WEST AND BRING MULTIPLE BOUNDARIES INTO AND
THROUGH THE REGION.
THERE IS GOOD AGREEMENT THAT THE THE LONGWAVE PATTERN WILL
TRANSITION INTO A FAST ZONAL FLOW EARLY NEXT WEEK. WITH THIS
COMES UNCERTAINTY IN TIMING OF INDIVIDUAL FEATURES. AT THIS TIME
EXPECT TUESDAY AND POSSIBLY WEDNESDAY TO BE DRY AS HIGH PRESSURE
MOVES ACROSS THE REGION.
AFTER A COLD START ON SATURDAY...THEN SEASONABLE TEMPERATURES ARE
EXPECTED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
LAKE EFFECT ACTIVITY CONTINUES DOWNWIND OF LAKE ONTARIO AND THIS
WILL CONTINUE THROUGH THE REMAINDER OF THE OVERNIGHT HOURS. THE
BAND IS EXPECTED TO LIFT NORTHWARD DURING THE MORNING HOURS. IN THE
MEANTIME...SOME OF THESE LAKE CLOUDS WILL IMPACT THE KGFL-KALB-KPSF
SITES WITH EXPECTATIONS THAT CIGS WOULD REMAIN ABOVE OR JUST TOUCH
THE MVFR THRESHOLDS. HOWEVER...NO RESTRICTIONS TO VIS ARE EXPECTED
AT THIS TIME. THEREAFTER...VFR CONDITIONS SHOULD PREVAIL FOR THE
REMAINDER OF THE TAF FORECAST CYCLE.
WESTERLY WINDS WILL CONTINUE OVERNIGHT AND INCREASE THROUGH THURSDAY
AS THE COMBINATION OF INCREASING MIXING LAYER HEIGHTS AND STILL A
TIGHT SURFACE PRESSURE GRADIENT HOLDS ACROSS THE REGION. GUSTS AT
OR ABOVE THE 20KT THRESHOLD IS EXPECTED. THOSE VALUES WILL GREATLY
DIMINISH WITHIN AN HOUR OR TWO OF SUNSET.
OUTLOOK...
THU OVRNT. VFR/MVFR. CHC -SHRA.
FRI...VFR. CHC -SHRA IN THE AM.
FRI PM-SAT...VFR. NO SIG WX.
SAT NT-MON...VFR/MVFR CHC -SHRA.
&&
.FIRE WEATHER...
A COLD FRONT WILL MOVE ACROSS EASTERN NEW YORK AND
WESTERN NEW ENGLAND THIS EVENING WITH SOME SCATTERED SHOWERS
PERSISTING NORTHWEST OF THE CAPITAL REGION. A FEW SNOW SHOWERS MAY
OCCUR OVER THE SOUTHERN ADIRONDACKS. HIGH PRESSURE WILL BRIEFLY
BUILD IN FROM THE OHIO VALLEY WITH COOL AND BRISK CONDITIONS
TOMORROW. THE WINDS WILL BE FROM THE WEST OR NORTHWEST AT 10 TO 20
MPH...WITH SOME GUSTS TO AROUND 30 MPH.
SCATTERED LIGHT SHOWERS ARE EXPECTED THURSDAY NIGHT INTO FRIDAY
MORNING WITH ANOTHER COLD FRONT. SOME VERY LIGHT SNOW
ACCUMULATIONS ARE POSSIBLE IN THE SOUTHERN ADIRONDACK REGION. THE
WINDS WILL INCREASE FROM THE NORTHWEST AT 10 TO 20 MPH WITH SOME
GUSTS CLOSE TO 30 MPH FRIDAY AFTERNOON...AND THE WINDS WILL BECOME
LIGHT TO CALM FRIDAY NIGHT. A WIDESPREAD FREEZE WILL BE POSSIBLE
SATURDAY MORNING.
&&
.HYDROLOGY...
NO HYDRO RELATED PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS.
THE PRECIPITATION WITH THE COLD FRONTAL PASSAGE TONIGHT WILL AMOUNT
TO A FEW HUNDREDTHS TO A FEW TENTHS OF AN INCH.
ANOTHER COLD FRONT MAY FOCUS ANOTHER ROUND OF LIGHT SHOWERS THURSDAY
NIGHT INTO FRIDAY...SOME OF WHICH COULD FALL AS SNOW SHOWERS
ACROSS THE ADIRONDACKS WITH LITTLE OR NO NO ACCUMULATIONS
EXPECTED. QPF AMOUNTS WILL RANGE FROM A FEW HUNDREDTHS TO A FEW
TENTHS OF AN INCH AGAIN.
DRY AND COLD WEATHER WILL RETURN FRIDAY NIGHT INTO SATURDAY
NIGHT.
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...IAA/WASULA
NEAR TERM...IAA/HWJIV
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...BGM
FIRE WEATHER...WASULA
HYDROLOGY...WASULA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
400 AM CDT THU OCT 11 2012
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1111 PM CDT WED OCT 10 2012
THE 11.00Z 250 HPA RAOB MAP SHOWED CYCLONIC FLOW OFFSHORE AND ACROSS
CA. THE PEAK JET LEVEL WINDS ASSOCIATED WITH THIS FEATURE WAS AROUND
90 KT EXTENDING ACROSS SOUTHERN CALIFORNIA. DOWNSTREAM, A STRONG NORTHWESTERLY
JET EXTENDED FROM THE CENTRAL CANADIAN PRAIRIE PROVINCES SOUTHEAST TO
THE GREAT LAKES REGION. A JET STREAK OF 140 KT WAS OBSERVED FROM KINL
TO KGRB. AT 500 HPA, OUR NEXT WEATHER SYSTEM WAS OBVIOUS PER GEOPOTENTIAL
HEIGHT ANALYSIS, WIND FIELDS AND SATELLITE WATER VAPOR IMAGERY. THIS
FEATURE WAS A 559 DM LOW LOCATED SSW OF KSFO. AN ASSOCIATED COLD POOL
OF -21 DEG C WAS OBSERVED AT KOAK. OTHERWISE, A BROAD TROUGH WAS LOCATED
ACROSS MUCH OF CENTRAL AND EASTERN CANADA WITH MID LEVEL TEMPERATURES
AS COLD AS -37 DEG C ACROSS CENTRAL MANITOBA. AT 700 HPA, -1 DEG C TEMPS
WERE ASSOCIATED WITH THE WEST COAST LOW. TO THE NORTHEAST, IMPRESSIVE
COLD TEMPERATURES AS LOW AS -19 DEG C WERE OBSERVED ACROSS MANITOBA
AND ONTARIO. THE AIRMASS IN THIS REGION WAS ALSO FAIRLY SATURATED. AT
850 HPA, A WARM AIR ADVECTION PATTERN WAS IN PLACE ACROSS THE CENTRAL
AND SOUTHERN PLAINS WITH MANY UPPER AIR SITES REPORTING SEVERAL DEGREES
OF WARMING BETWEEN THE 10.00Z AND 11.00Z FLIGHTS. SOME MOISTURE ADVECTION
WAS NOTED DOWNSTREAM OF THE AFOREMENTIONED LOW ACROSS SOUTHERN CALIFORNIA.
LOW DEWPOINT DEPRESSIONS - ASSOCIATED WITH STRATUS WAS ALSO NOTED ACROSS
PORTIONS OF TEXAS AND OKLAHOMA. AT THE SFC, A PLETHORA OF FRONTS WERE
NOTED ACROSS THE CONUS...ONE ACROSS MONTANA AND THE DAKOTAS, A STATIONARY
FRONT BUCKED UP ACROSS THE ROCKIES EXTENDING INTO PORTIONS OF TEXAS...AND
A COLD FRONT ACROSS THE DEEP SOUTH EXTENDING NE TO NEW ENGLAND. RICH
BOUNDARY LAYER MOISTURE /MARKED BY DEWPOINTS IN THE UPPER 60S DEG F/
WERE SOUTH OF SAID TWO FRONTS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 400 AM CDT THU OCT 11 2012
THIS MORNING:
THE 11-3.9 MICRON SATELLITE IMAGERY SHOWS STRATUS WORKING ITS WAY NORTHWARD
EARLY THIS MORNING. PLAN VIEW RH`S PROGS SHOW NEAR 100 PERCENT SATURATION
WITHIN THE BOUNDARY LAYER, HOWEVER, BUFKIT SOUNDINGS ARE A LITTLE LESS
AGGRESSIVE WITH FOG FORMATION AND LOW LEVEL STRATUS. WILL CONTINUE TO
ADVECT THE CLOUD COVER NORTHWARD THIS MORNING. A LEE LOW WILL STRENGTHEN
THROUGH THE MORNING HOURS AND ALSO TRANSLATE EAST FARTHER. THIS WILL
RESULT IN A MORE DOWNSLOPE SSW/SW WIND FROM THE SFC THROUGH 700 HPA.
AS A RESULT, EXPECT SKIES TO CLEAR THROUGH THE MID MORNING HOURS. DENSE
FOG IS NOT EXPECTED THIS MORNING AS T/TD DEPRESSIONS ARE FAIRLY LARGE
AT THE SURFACE.
TODAY:
A COLD FRONT WILL TRAVERSE ACROSS THE REGION THROUGH THE AFTERNOON.
A STRONG TEMPERATURES GRADIENT IS EXPECTED ACROSS SW KANSAS WITH HIGHS
AROUND 70 DEG F ACROSS THE INTERSTATE 70 CORRIDOR TO VERY WARM TEMPERATURES
IN THE MID TO UPPER 80S DEG F ALONG THE KANSAS/OKLAHOMA BORDER. BOISE
VERIFICATION SHOWS THAT THE NAM12BC MODEL IS PERFORMING BETTER THAN
OTHER GUIDANCE SO WILL GO WITH THIS SOLUTION FOR NOW. 850 HPA WINDS
BEHIND THE FRONT ARE NOT THAT STRONG (~20 KT) SO THERE WILL NOT BE
MUCH WIND WITH THIS FRONT (15-20 KT AT THE SFC).
TONIGHT:
ATTENTION THEN TURNS TO CONVECTIVE PROSPECTS FOR THIS EVENING. MESOSCALE
MODELS SUCH AS THE 00Z/06Z NAM AND THE 00Z ARW-NMM CORE SUGGEST CONVECTION
ALONG THE STATE LINE AFTER SUNSET. THIS ACTIVITY IS IN RESPONSE INCREASING
850 HPA THETA-E ADVECTION AND 850-700 HPA FRONTOGENESIS. THE UPPER LEVEL
DISTURBANCE MENTIONED IN THE SYNOPSIS WILL STILL BE WAY WEST OF THE
REGION, HOWEVER, FORECAST MUCAPE OF 1500 J/KG...30-35 KT OF 0-6 KM BULK
SHEAR...AND FAIRLY STEEP 700-500 HPA AND 500-300 HPA LAPSE RATES (~7.3
DEG C/KM) SUGGEST THE THREAT FOR A LOW END HAIL EVENT. WILL HIGHLIGHT
THIS CONCERN IN THE HWO. CONVECTION SHOULD BE FAIRLY ELEVATED AS THE
COLD AIR UNDERCUTS BUOYANT PARCELS ALOFT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 322 AM CDT THU OCT 11 2012
STARTING WITH FRIDAY MORNING, THERE WILL BE UPPER DIFFLUENCE OVER
MUCH OF WESTERN KANSAS EARLY FRIDAY, WITH A WARM FRONT STARTING TO
EDGE NORTHWARD DURING THE DAY FRIDAY. THERE COULD BE A FEW
THUNDERSTORMS DOWN IN THE PRATT AND MEDICINE LODGE AREAS EARLY
FRIDAY MORNING. BUT THE MORE DEEPER, UNSTABLE CONVECTIVE MODE WILL
START DURING THE AFTERNOON FRIDAY AND EXTEND INTO THE NIGHT. ALL
MODELS POINT TOWARDS AROUND 1000 J/KG OF CAPE DEVELOPING FRIDAY
AFTERNOON AS THE SURFACE WARMS UP SOUTH OF THE WARM FRONT. A WAVE
OF 500MB VORTICITY STREAMS NORTHEASTWARD ACROSS SOUTHERN KANSAS
FRIDAY EVENING AROUND 00Z, WITH A 70 TO 80 KNOT 500MB JET CURVING
FROM NORTHERN NEW MEXICO TO WESTERN NEBRASKA. THIS JET WILL
INCREASE UPPER LEVEL FORCING FOR STRONGER VERTICAL MOTION TO DEVELOP,
WHICH WILL ALSO SHARPEN THE SHEAR PROFILE. HAVE OPTED TO PLACE
T+RW(M) WEATHER TYPE IN FROM APPROXIMATELY 20Z FRIDAY THROUGH 09Z
SATURDAY MORNING. LARGE HAIL LOOKS TO BE THE PRIMARY RISK FACTOR
FRIDAY EVENING AND FRIDAY NIGHT, BUT LOWER LEVEL CIRCULATION WILL
NEED TO BE WATCHED FOR THE POSSIBLE DEVELOPMENT OF TORNADOES FRIDAY
NIGHT. THIS SHIFT HAS DECIDED TO PRODUCE A MULTIMEDIA BRIEFING AND
WILL PLACE IT ON OUR WEB PAGE TO HEIGHTEN AWARENESS TO THIS SEVERE
POTENTIAL.
SATURDAY WILL SEE THE ABOVE MENTIONED FRONT MOVE BACK SOUTHEASTWARD
AS A COLD FRONT, WITH THE BASE OF THE UPPER TROUGH ADVANCING INTO
FAR WESTERN KANSAS BY 18Z SATURDAY AND TO EAST-CENTRAL KANSAS BY 00Z
SUNDAY. LOWER 30 PERCENT POPS WILL LINGER IN MY FAR SOUTHEASTERN
ZONES NEAR MEDICINE LODGE SATURDAY MORNING WHERE THE COLD FRONT
SHOULD BE, AND THEN DIMINISH TO LESS THAN 10 PERCENT BY SATURDAY
EVENING. AFTER SATURDAY, POPS LOOK NIL FOR SUNDAY THROUGH
WEDNESDAY AS A NEAR ZONAL FLOW ESTABLISHES A HOLD IN THE UPPER
FLOW. ONE SMALL WAVE MOVES THROUGH PER THE ECMWF MODEL ON
WEDNESDAY, BUT THE UPPER DYNAMICS WITH THIS WAVE SHOULD STAY NORTH
OF OUR FORECAST AREA OF SOUTHWEST KANSAS.
TEMPERATURES WILL START OUT DIVIDED ON FRIDAY WITH CLOUDS AND COOL
AIR KEEPING AREAS NORTH OF A LACROSSE TO SYRACUSE LINE WITH MAX
TEMPERATURES IN THE UPPER 50S. SOUTH OF THAT LINE AND SOUTH OF THE
AFTERNOON WARM FRONT, TEMPERATURES WILL APPROACH THE LOWER 70S FROM
LIBERAL TO COLDWATER. MAXIMUM TEMPERATURES FROM SATURDAY THROUGH
TUESDAY SHOULD TOP OUT IN THE UPPER 70S TO LOWER 80S AS A WEST FLOW
DEVELOPS ALOFT, WITH PERHAPS TUESDAY THE WARMEST DAY. THAT WAVE
MENTIONED ABOVE FOR WEDNESDAY WILL BRING CLOUDS AND SLIGHTLY COOLER
AIR, PRODUCING HIGHS ON WEDNESDAY IN THE 70S. MINIMUM TEMPERATURES
SATURDAY MORNING NEAR 50F IN ALONG THE COLORADO BORDER AND AROUND
THE MID 60S NEAR PRATT, WILL LOWER TO THE LOWER 40S TO MID 50S (SE)
SUNDAY, BUT THEN WARM INTO THE 50S MON, TUE, AND WED. LOOKING
AHEAD, THURSDAY`S MINS COULD DIP BACK INTO THE 40S AS COOL AIR
INFILTRATES WESTERN KANSAS FROM THE NORTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1234 AM CDT THU OCT 11 2012
MAIN CONCERN FOR 06Z TAFS IS CIGS. LOW PRESSURE LOCATED ACROSS THE LEE
OF THE ROCKIES WILL KEEP SSE WINDS IN THE FORECAST THROUGH THE OVERNIGHT
HOURS. LOW STRATUS HAS BEGUN TO CREEP CLOSER WITH PRATT REPORTING CLOSE
TO MVFR CIGS. AN INSPECTION OF PLAN VIEW RH PROGS WITHIN THE BOUNDARY
LAYER SHOW NEAR SATURATION, HOWEVER, INSPECTING BUFKIT FORECAST SOUNDINGS
SHOW LESS OF PROBLEM THAN WHAT THE HRRR IS SUGGESTING (NAMELY VIS).
ANYWAY, WILL PUT MVFR CIGS FOR KGCK/KDDC THIS MORNING. CONFIDENCE IS
LOWER FOR MVFR CIGS AT KHYS DUE TO A DRIER PROFILE. BY MID MORNING,
A DOWNSLOPE SW IS EXPECTED AHEAD OF A COLD FRONT WHICH SHOULD ALLOW
FOR VFR CIGS. THIS FRONT WILL TRAVERSE ACROSS MUCH OF THE REGION BY
THE AFTERNOON. SECOND CONCERN IS CONVECTION LATE THIS EVENING, HOWEVER,
THIS ACTIVITY SHOULD REMAIN SOUTH OF THE TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 82 49 68 61 / 10 20 40 70
GCK 80 45 60 58 / 0 10 60 70
EHA 86 49 68 52 / 10 30 60 70
LBL 86 51 70 59 / 10 40 60 70
HYS 72 44 59 58 / 0 10 30 70
P28 85 60 73 63 / 20 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...BURKE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
329 AM CDT THU OCT 11 2012
...UPDATED FOR THE LONG RANGE FORECAST...
.SYNOPSIS...
ISSUED AT 1111 PM CDT WED OCT 10 2012
THE 11.00Z 250 HPA RAOB MAP SHOWED CYCLONIC FLOW OFFSHORE AND ACROSS
CA. THE PEAK JET LEVEL WINDS ASSOCIATED WITH THIS FEATURE WAS AROUND
90 KT EXTENDING ACROSS SOUTHERN CALIFORNIA. DOWNSTREAM, A STRONG NORTHWESTERLY
JET EXTENDED FROM THE CENTRAL CANADIAN PRAIRIE PROVINCES SOUTHEAST TO
THE GREAT LAKES REGION. A JET STREAK OF 140 KT WAS OBSERVED FROM KINL
TO KGRB. AT 500 HPA, OUR NEXT WEATHER SYSTEM WAS OBVIOUS PER GEOPOTENTIAL
HEIGHT ANALYSIS, WIND FIELDS AND SATELLITE WATER VAPOR IMAGERY. THIS
FEATURE WAS A 559 DM LOW LOCATED SSW OF KSFO. AN ASSOCIATED COLD POOL
OF -21 DEG C WAS OBSERVED AT KOAK. OTHERWISE, A BROAD TROUGH WAS LOCATED
ACROSS MUCH OF CENTRAL AND EASTERN CANADA WITH MID LEVEL TEMPERATURES
AS COLD AS -37 DEG C ACROSS CENTRAL MANITOBA. AT 700 HPA, -1 DEG C TEMPS
WERE ASSOCIATED WITH THE WEST COAST LOW. TO THE NORTHEAST, IMPRESSIVE
COLD TEMPERATURES AS LOW AS -19 DEG C WERE OBSERVED ACROSS MANITOBA
AND ONTARIO. THE AIRMASS IN THIS REGION WAS ALSO FAIRLY SATURATED. AT
850 HPA, A WARM AIR ADVECTION PATTERN WAS IN PLACE ACROSS THE CENTRAL
AND SOUTHERN PLAINS WITH MANY UPPER AIR SITES REPORTING SEVERAL DEGREES
OF WARMING BETWEEN THE 10.00Z AND 11.00Z FLIGHTS. SOME MOISTURE ADVECTION
WAS NOTED DOWNSTREAM OF THE AFOREMENTIONED LOW ACROSS SOUTHERN CALIFORNIA.
LOW DEWPOINT DEPRESSIONS - ASSOCIATED WITH STRATUS WAS ALSO NOTED ACROSS
PORTIONS OF TEXAS AND OKLAHOMA. AT THE SFC, A PLETHORA OF FRONTS WERE
NOTED ACROSS THE CONUS...ONE ACROSS MONTANA AND THE DAKOTAS, A STATIONARY
FRONT BUCKED UP ACROSS THE ROCKIES EXTENDING INTO PORTIONS OF TEXAS...AND
A COLD FRONT ACROSS THE DEEP SOUTH EXTENDING NE TO NEW ENGLAND. RICH
BOUNDARY LAYER MOISTURE /MARKED BY DEWPOINTS IN THE UPPER 60S DEG F/
WERE SOUTH OF SAID TWO FRONTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 254 PM CDT WED OCT 10 2012
THE MAIN FORECAST CHALLENGES ARE HIGHS THURSDAY AND THUNDERSTORM
CHANCES LATE THURSDAY AFTERNOON.
AS AN UPPER-LOW TAKES SHAPE OVER THE SOUTHWESTERN UNITED STATES, A
STRONG SURFACE HIGH WILL MOVE SOUTHEASTWARD FROM NORTHERN ALASKA
INTO THE NORTHERN PLAINS IN RESPONSE TO UPPER-LEVEL TROUGHING OVER
THE GREAT LAKES. MID-LEVEL DOWNSLOPE FLOW OVER THE SOUTHERN HIGH PLAINS
AND MEXICO WITH THE SOUTHWESTERN SYSTEM WILL ENCOURAGE LEE TROUGHING
OVER THE SOUTHERN HIGH PLAINS, WITH GULF MOISTURE RETURN INTO THE
SOUTHERN PLAINS. A BAROCLINIC ZONE WILL BECOME ESTABLISHED ACROSS
SOUTHERN KANSAS BY LATE THURSDAY AFTERNOON. GULF MOISTURE CONVERGING
ALONG THIS FRONT MAY WILL LEAD TO THUNDERSTORM DEVELOPMENT BY LATE
AFTERNOON NEAR THE OKLAHOMA STATE LINE. WITH SURFACE BASED CAPE
VALUES AROUND 1000-1500 J/KG AND DECENT SHEAR, SOME HAIL IS POSSIBLE
UP TO THE SIZE OF QUARTERS. HIGHS THURSDAY SHOULD RANGE FROM THE
UPPER 60S AND LOWER 70S ACROSS NORTHERN TREGO AND ELLIS COUNTIES
TO THE UPPER 80S TO EVEN LOWER 90S OVER BARBER AND COMANCHE
COUNTIES.
IN THE NEAR TERM, LOW LEVEL WARM ADVECTION WAS BEGINNING ACROSS
WEST TEXAS THIS AFTERNOON. THE NAM MODEL SOUNDINGS SUGGEST LOW
STRATUS FORMATION BY 09Z AND THEN ERODING BY 15Z WITH DAYTIME
HEATING. LOWS SHOULD BE HELD UP IN THE MID TO HIGH 40S DUE TO THE
SOUTH WIND AT 10 KTS, CLOUD COVER AND INCREASING DEWPOINTS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 322 AM CDT THU OCT 11 2012
STARTING WITH FRIDAY MORNING, THERE WILL BE UPPER DIFFLUENCE OVER
MUCH OF WESTERN KANSAS EARLY FRIDAY, WITH A WARM FRONT STARTING TO
EDGE NORTHWARD DURING THE DAY FRIDAY. THERE COULD BE A FEW
THUNDERSTORMS DOWN IN THE PRATT AND MEDICINE LODGE AREAS EARLY
FRIDAY MORNING. BUT THE MORE DEEPER, UNSTABLE CONVECTIVE MODE WILL
START DURING THE AFTERNOON FRIDAY AND EXTEND INTO THE NIGHT. ALL
MODELS POINT TOWARDS AROUND 1000 J/KG OF CAPE DEVELOPING FRIDAY
AFTERNOON AS THE SURFACE WARMS UP SOUTH OF THE WARM FRONT. A WAVE
OF 500MB VORTICITY STREAMS NORTHEASTWARD ACROSS SOUTHERN KANSAS
FRIDAY EVENING AROUND 00Z, WITH A 70 TO 80 KNOT 500MB JET CURVING
FROM NORTHERN NEW MEXICO TO WESTERN NEBRASKA. THIS JET WILL
INCREASE UPPER LEVEL FORCING FOR STRONGER VERTICAL MOTION TO DEVELOP,
WHICH WILL ALSO SHARPEN THE SHEAR PROFILE. HAVE OPTED TO PLACE
T+RW(M) WEATHER TYPE IN FROM APPROXIMATELY 20Z FRIDAY THROUGH 09Z
SATURDAY MORNING. LARGE HAIL LOOKS TO BE THE PRIMARY RISK FACTOR
FRIDAY EVENING AND FRIDAY NIGHT, BUT LOWER LEVEL CIRCULATION WILL
NEED TO BE WATCHED FOR THE POSSIBLE DEVELOPMENT OF TORNADOES FRIDAY
NIGHT. THIS SHIFT HAS DECIDED TO PRODUCE A MULTIMEDIA BRIEFING AND
WILL PLACE IT ON OUR WEB PAGE TO HEIGHTEN AWARENESS TO THIS SEVERE
POTENTIAL.
SATURDAY WILL SEE THE ABOVE MENTIONED FRONT MOVE BACK SOUTHEASTWARD
AS A COLD FRONT, WITH THE BASE OF THE UPPER TROUGH ADVANCING INTO
FAR WESTERN KANSAS BY 18Z SATURDAY AND TO EAST-CENTRAL KANSAS BY 00Z
SUNDAY. LOWER 30 PERCENT POPS WILL LINGER IN MY FAR SOUTHEASTERN
ZONES NEAR MEDICINE LODGE SATURDAY MORNING WHERE THE COLD FRONT
SHOULD BE, AND THEN DIMINISH TO LESS THAN 10 PERCENT BY SATURDAY
EVENING. AFTER SATURDAY, POPS LOOK NIL FOR SUNDAY THROUGH
WEDNESDAY AS A NEAR ZONAL FLOW ESTABLISHES A HOLD IN THE UPPER
FLOW. ONE SMALL WAVE MOVES THROUGH PER THE ECMWF MODEL ON
WEDNESDAY, BUT THE UPPER DYNAMICS WITH THIS WAVE SHOULD STAY NORTH
OF OUR FORECAST AREA OF SOUTHWEST KANSAS.
TEMPERATURES WILL START OUT DIVIDED ON FRIDAY WITH CLOUDS AND COOL
AIR KEEPING AREAS NORTH OF A LACROSSE TO SYRACUSE LINE WITH MAX
TEMPERATURES IN THE UPPER 50S. SOUTH OF THAT LINE AND SOUTH OF THE
AFTERNOON WARM FRONT, TEMPERATURES WILL APPROACH THE LOWER 70S FROM
LIBERAL TO COLDWATER. MAXIMUM TEMPERATURES FROM SATURDAY THROUGH
TUESDAY SHOULD TOP OUT IN THE UPPER 70S TO LOWER 80S AS A WEST FLOW
DEVELOPS ALOFT, WITH PERHAPS TUESDAY THE WARMEST DAY. THAT WAVE
MENTIONED ABOVE FOR WEDNESDAY WILL BRING CLOUDS AND SLIGHTLY COOLER
AIR, PRODUCING HIGHS ON WEDNESDAY IN THE 70S. MINIMUM TEMPERATURES
SATURDAY MORNING NEAR 50F IN ALONG THE COLORADO BORDER AND AROUND
THE MID 60S NEAR PRATT, WILL LOWER TO THE LOWER 40S TO MID 50S (SE)
SUNDAY, BUT THEN WARM INTO THE 50S MON, TUE, AND WED. LOOKING
AHEAD, THURSDAY`S MINS COULD DIP BACK INTO THE 40S AS COOL AIR
INFILTRATES WESTERN KANSAS FROM THE NORTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1234 AM CDT THU OCT 11 2012
MAIN CONCERN FOR 06Z TAFS IS CIGS. LOW PRESSURE LOCATED ACROSS THE LEE
OF THE ROCKIES WILL KEEP SSE WINDS IN THE FORECAST THROUGH THE OVERNIGHT
HOURS. LOW STRATUS HAS BEGUN TO CREEP CLOSER WITH PRATT REPORTING CLOSE
TO MVFR CIGS. AN INSPECTION OF PLAN VIEW RH PROGS WITHIN THE BOUNDARY
LAYER SHOW NEAR SATURATION, HOWEVER, INSPECTING BUFKIT FORECAST SOUNDINGS
SHOW LESS OF PROBLEM THAN WHAT THE HRRR IS SUGGESTING (NAMELY VIS).
ANYWAY, WILL PUT MVFR CIGS FOR KGCK/KDDC THIS MORNING. CONFIDENCE IS
LOWER FOR MVFR CIGS AT KHYS DUE TO A DRIER PROFILE. BY MID MORNING,
A DOWNSLOPE SW IS EXPECTED AHEAD OF A COLD FRONT WHICH SHOULD ALLOW
FOR VFR CIGS. THIS FRONT WILL TRAVERSE ACROSS MUCH OF THE REGION BY
THE AFTERNOON. SECOND CONCERN IS CONVECTION LATE THIS EVENING, HOWEVER,
THIS ACTIVITY SHOULD REMAIN SOUTH OF THE TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 82 49 68 61 / 10 20 40 70
GCK 80 45 60 58 / 0 10 60 70
EHA 86 49 68 52 / 10 30 60 70
LBL 86 51 70 59 / 10 40 60 70
HYS 72 44 59 58 / 0 10 30 70
P28 85 60 73 63 / 20 70 50 60
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...FINCH
LONG TERM...BURKE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1147 PM MDT WED OCT 10 2012
.UPDATE...
ISSUED AT 225 PM MDT WED OCT 10 2012
MADE MINOR ADJUSTMENT TO WX/SKY GRIDS FOR TONIGHT PERIOD...TO
INCREASE SKY COVER AND ADD PATCHY FOG. NAM/RUC BOTH SHOWING DECENT
BL MOISTURE ADVECTING NORTH. WITH BETTER CLEARING SOUTH
COULDNT RULE OUT STRATUS/FOG DEVELOPING AND THEN ADVECTING NORTH
OUT OF SE CO AND SW KS. NOT SURE HOW FAR NORTH THIS WILL GET...SO
I ONLY LIMITED IT TO THE FAR SOUTHERN TIER OF COUNTIES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 1203 PM MDT WED OCT 10 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW SIMILAR PATTERN AS THE
LAST FEW DAYS...WITH BROAD TROUGH ACROSS CANADA EXTENDING SOUTH
ACROSS THE EASTERN US. A REX BLOCK IS ALSO STILL IN PLACE OFF THE
WESTERN US...WITH A CLOSED UPPER LOW BEGINNING TO MOVE OVER THE
CENTRAL CALIFORNIA COAST. A SHORTWAVE RIDGE EXTENDS NORTH OVER
WESTERN COLORADO AND TOWARDS THE GREAT BASIN. AT THE SURFACE HIGH
PRESSURE EXTENDS FROM THE CENTRAL MISSISSIPPI VALLEY WEST INTO
CENTRAL KANSAS. A LEE TROUGH IS DEEPENING OVER EASTERN
COLORADO...WITH INCREASING PRESSURE GRADIENT OVER WESTERN KS BETWEEN
THESE FEATURES.
GOOD WAA OVERNIGHT TONIGHT...COMBINED WITH MID-HIGH CLOUD COVER
COMPLICATES THE LOW TEMPERATURE. WINDS SHOULD DIMINISH AROUND
SUNSET AS DAYTIME HEATING COMES TO AN END...AND THE LEE TROUGH
AXIS SHIFTS EAST OVER THE CWA...SO WINDS SHOULD NOT BE AS MUCH OF
AN ISSUE. TEMPERATURES CURRENTLY EXPECTED TO BE IN THE 40S ACROSS
MOST OF THE AREA. IF CLOUD COVER WERE TO BE MORE EXTENSIVE WE
MAY SEE OVERNIGHT TEMPS CLOSER TO 50F AT SOME LOCATIONS.
A COLD FRONT WILL PUSH SOUTH OVER THE CWA AS A SHORTWAVE TROUGH
MOVES FROM SOUTHERN CANADA INTO NORTHERN MINNESOTA THURSDAY. WITH
VERY LITTLE IN MOISTURE IN PLACE AND BEST LARGE SCALE ASCENT WELL TO
THE NORTH AND EAST...NO PRECIP IS EXPECTED. LATEST GUIDANCE FAVORS
FRONTAL PASSAGE AROUND 15Z ACROSS MOST OF THE CWA...AND AROUND 18Z
ACROSS THE SOUTHERN HALF OF THE CWA. I HAVE TRENDED TEMPS DOWN
ACCORDINGLY...WITH HIGHS IN THE UPPER 50S/LOW 60S ACROSS THE
NORTH...AND NEAR 70 ACROSS THE SOUTH.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1251 PM MDT WED OCT 10 2012
SYSTEM CURRENTLY OVER SOUTHERN CALIFORNIA WILL LIFT OUT ACROSS THE
SOUTHERN AND CENTRAL ROCKIES FRIDAY AND SATURDAY. BEST LIFT LOCALLY
WILL OCCUR FRIDAY AFTERNOON THROUGH FRIDAY NIGHT. COOL AND STABLE
CONDITIONS ARE FORECAST FOR FRIDAY WHICH WILL RESULT IN SURFACE
INSTABILITY OF ZERO. HOWEVER...THERE IS WEAK ELEVATED INSTABILITY
AND DEEP LAYER SHEAR IS UP TO 40KTS. THERE IS SOME WEAK SURFACE
BASED INSTABILITY FORECAST LATE FRIDAY NIGHT...SO CANNOT RULE OUT
THE POSSIBILITY OF A SEVERE STORM MOVING INTO AREAS SOUTH OF INTERSTATE
70 FROM SOUTHWEST KANSAS FRIDAY NIGHT. AFTER MIDNIGHT A MASSIVE
MID LEVEL DRY SLOT WILL OVERSPREAD THE FORECAST AREA...ENDING THE
PRECIPITATION CHANCES FOR ALL BUT THE FAR NORTHWEST CORNER WHICH
COULD RECEIVE SOME LIGHT WRAPAROUND PRECIPITATION THROUGH SATURDAY
MORNING. CLEARING IS EXPECTED BY SATURDAY AFTERNOON FOR THE ENTIRE
AREA.
RIDGING IS FORECAST FOR SUNDAY AND MONDAY WITH ABOVE NORMAL
TEMPERATURES AND DRY CONDITIONS. NEXT SHORTWAVE TROUGH WILL
APPROACH THE NORTHERN ROCKIES MONDAY NIGHT AND MOVE ACROSS THE
AREA TUESDAY OR WEDNESDAY. HOWEVER...MOISTURE APPEARS TO BE
LACKING FOR PRECIPITATION CHANCES. ASSOCIATED SURFACE COLD FRONT
COULD PRODUCE WINDY CONDITIONS TUESDAY NIGHT AND WEDNESDAY GIVEN
STRONG UPPER JET IN THE VICINITY. ONLY SLIGHT COOLING IS EXPECTED
WITH FRONTAL PASSAGE GIVEN PACIFIC ORIGIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1142 PM MDT WED OCT 10 2012
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. WINDS WILL BE TURING FROM THE SOUTH TO THE NORTHWEST
THROUGH THE OVERNIGHT HOURS WITH A COLD FRONT EXPECTED TO MOVE
THROUGH THE TAF SITES AFTER 15Z. WINDS BEHIND THE FRONT WILL
BECOME GUSTY FROM THE NORTH. NO PRECIPITATION IS EXPECTED WITH
THIS FRONT AS ONLY HIGHER CLOUDS ARE EXPECTED. WIND SPEEDS WILL
DECREASE AND LOSE THE GUSTS AFTER SUNSET AROUND 01Z WITH THE WIND
DIRECTION BECOME NORTHEAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...024
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1234 AM CDT THU OCT 11 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 1111 PM CDT WED OCT 10 2012
THE 11.00Z 250 HPA RAOB MAP SHOWED CYCLONIC FLOW OFFSHORE AND ACROSS
CA. THE PEAK JET LEVEL WINDS ASSOCIATED WITH THIS FEATURE WAS AROUND
90 KT EXTENDING ACROSS SOUTHERN CALIFORNIA. DOWNSTREAM, A STRONG NORTHWESTERLY
JET EXTENDED FROM THE CENTRAL CANADIAN PRAIRIE PROVINCES SOUTHEAST TO
THE GREAT LAKES REGION. A JET STREAK OF 140 KT WAS OBSERVED FROM KINL
TO KGRB. AT 500 HPA, OUR NEXT WEATHER SYSTEM WAS OBVIOUS PER GEOPOTENTIAL
HEIGHT ANALYSIS, WIND FIELDS AND SATELLITE WATER VAPOR IMAGERY. THIS
FEATURE WAS A 559 DM LOW LOCATED SSW OF KSFO. AN ASSOCIATED COLD POOL
OF -21 DEG C WAS OBSERVED AT KOAK. OTHERWISE, A BROAD TROUGH WAS LOCATED
ACROSS MUCH OF CENTRAL AND EASTERN CANADA WITH MID LEVEL TEMPERATURES
AS COLD AS -37 DEG C ACROSS CENTRAL MANITOBA. AT 700 HPA, -1 DEG C TEMPS
WERE ASSOCIATED WITH THE WEST COAST LOW. TO THE NORTHEAST, IMPRESSIVE
COLD TEMPERATURES AS LOW AS -19 DEG C WERE OBSERVED ACROSS MANITOBA
AND ONTARIO. THE AIRMASS IN THIS REGION WAS ALSO FAIRLY SATURATED. AT
850 HPA, A WARM AIR ADVECTION PATTERN WAS IN PLACE ACROSS THE CENTRAL
AND SOUTHERN PLAINS WITH MANY UPPER AIR SITES REPORTING SEVERAL DEGREES
OF WARMING BETWEEN THE 10.00Z AND 11.00Z FLIGHTS. SOME MOISTURE ADVECTION
WAS NOTED DOWNSTREAM OF THE AFOREMENTIONED LOW ACROSS SOUTHERN CALIFORNIA.
LOW DEWPOINT DEPRESSIONS - ASSOCIATED WITH STRATUS WAS ALSO NOTED ACROSS
PORTIONS OF TEXAS AND OKLAHOMA. AT THE SFC, A PLETHORA OF FRONTS WERE
NOTED ACROSS THE CONUS...ONE ACROSS MONTANA AND THE DAKOTAS, A STATIONARY
FRONT BUCKED UP ACROSS THE ROCKIES EXTENDING INTO PORTIONS OF TEXAS...AND
A COLD FRONT ACROSS THE DEEP SOUTH EXTENDING NE TO NEW ENGLAND. RICH
BOUNDARY LAYER MOISTURE /MARKED BY DEWPOINTS IN THE UPPER 60S DEG F/
WERE SOUTH OF SAID TWO FRONTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 254 PM CDT WED OCT 10 2012
THE MAIN FORECAST CHALLENGES ARE HIGHS THURSDAY AND THUNDERSTORM
CHANCES LATE THURSDAY AFTERNOON.
AS AN UPPER-LOW TAKES SHAPE OVER THE SOUTHWESTERN UNITED STATES, A
STRONG SURFACE HIGH WILL MOVE SOUTHEASTWARD FROM NORTHERN ALASKA
INTO THE NORTHERN PLAINS IN RESPONSE TO UPPER-LEVEL TROUGHING OVER
THE GREAT LAKES. MID-LEVEL DOWNSLOPE FLOW OVER THE SOUTHERN HIGH PLAINS
AND MEXICO WITH THE SOUTHWESTERN SYSTEM WILL ENCOURAGE LEE TROUGHING
OVER THE SOUTHERN HIGH PLAINS, WITH GULF MOISTURE RETURN INTO THE
SOUTHERN PLAINS. A BAROCLINIC ZONE WILL BECOME ESTABLISHED ACROSS
SOUTHERN KANSAS BY LATE THURSDAY AFTERNOON. GULF MOISTURE CONVERGING
ALONG THIS FRONT MAY WILL LEAD TO THUNDERSTORM DEVELOPMENT BY LATE
AFTERNOON NEAR THE OKLAHOMA STATE LINE. WITH SURFACE BASED CAPE
VALUES AROUND 1000-1500 J/KG AND DECENT SHEAR, SOME HAIL IS POSSIBLE
UP TO THE SIZE OF QUARTERS. HIGHS THURSDAY SHOULD RANGE FROM THE
UPPER 60S AND LOWER 70S ACROSS NORTHERN TREGO AND ELLIS COUNTIES
TO THE UPPER 80S TO EVEN LOWER 90S OVER BARBER AND COMANCHE
COUNTIES.
IN THE NEAR TERM, LOW LEVEL WARM ADVECTION WAS BEGINNING ACROSS
WEST TEXAS THIS AFTERNOON. THE NAM MODEL SOUNDINGS SUGGEST LOW
STRATUS FORMATION BY 09Z AND THEN ERODING BY 15Z WITH DAYTIME
HEATING. LOWS SHOULD BE HELD UP IN THE MID TO HIGH 40S DUE TO THE
SOUTH WIND AT 10 KTS, CLOUD COVER AND INCREASING DEWPOINTS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 353 PM CDT WED OCT 10 2012
THURSDAY NIGHT AND FRIDAY:
SCATTERED CONVECTION SHOULD DEVELOP ALONG THE QUASI-STATIONARY FRONT
DURING THE EVENING HOUR ALONG OR JUST SOUTH OF THE OKLAHOMA BORDER.
WILL MAINTAIN THE 30 TO 40 POPS ACROSS MAINLY THE OKLAHOMA BORDER
COUNTIES WITH A SMALL SLIVER OF 50 POPS ACROSS SOUTHERN BARBER
COUNTY (I.E. KIOWA, KS). UPPER LEVEL FLOW PATTERN WILL STILL BE
MAINLY OUT OF THE WEST WITHIN SHORTWAVE RIDGING SO NORTHWARD ADVANCE
OF STORMS INTO SOUTHWEST/SOUTH CENTRAL KS WILL BE VERY DIFFICULT.
MOST UNSTABLE CAPE OF 1500-2000 J/KG WILL SUPPORT SOME ISOLATED
SEVERE STORMS WITH SOME LARGE HAIL ALONG THE OKLAHOMA BORDER. THE
SURFACE FRONT WILL GRADUALLY LIFT NORTH THROUGH THE DAY FRIDAY WILL
AREAS OF DRIZZLE DEVELOPING IN THE NEAR-SURFACE DEFORMATION AXIS AT
THE ONSET OF LOWER 60S DEWPOINTS. SURFACE TEMPERATURES WILL BE
LOCKED IN THE MID TO UPPER 50S MOST OF THE DAY ACROSS MUCH OF
SOUTHWEST KANSAS...EXCEPT ALONG THE OKLAHOMA BORDER. WILL BE RAMPING
UP THE POPS INTO 40 TO 60 PERCENT CATEGORY SOUTH OF THE ARKANSAS
RIVER LATE IN THE DAY FRIDAY AS UPWARD VERTICAL MOTION INCREASES AND
ISOLATED/SCATTERED CONVECTION BECOMES MORE PROMINENT. WITH THE
SURFACE FRONT AND ATTENDANT SURFACE-BASED CAPE TO THE SOUTH OF
SOUTHWEST KANSAS...MOST AGGRESSIVE CONVECTION WILL STAY ACROSS THE
TEXAS PANHANDLE THROUGH THE AFTERNOON/EARLY EVENING FRIDAY.
FRIDAY NIGHT AND SATURDAY:
THE UPPER LOW AND MID LEVEL POTENTIAL VORTICITY ANOMALY WILL EJECT
NORTHEAST ACROSS KANSAS WHICH WILL SUBSEQUENTLY INCREASE WARM/MOIST
ADVECTION DRAMATICALLY ACROSS WESTERN KANSAS. SURFACE-BASED CAPE
WILL THEN INCREASE ACROSS FAR SOUTHWEST KANSAS FROM 00-03Z WITH
STRONG TO SEVERE CONVECTION FORMING ALONG ADVANCING PACIFIC COLD
FRONT FROM FAR SOUTHEAST COLORADO TO THE NORTHEASTERN TEXAS
PANHANDLE. THESE STORMS WILL MOST LIKELY MOVE TOWARD HIGHWAY 27
DURING THE 00-03Z TIME FRAME...ESPECIALLY JOHNSON TO ELKHART. 0-1KM
SRH WILL BE EXTREMELY HIGH WITH 300-400 M2/S2 AS DYNAMIC LOW LEVEL
JET FORMS OFF THE SURFACE TO THE TUNE OF 50-55 KNOTS. WITH THE
ADVANCE OF 600 TO 1000 J/KG SURFACE BASED CAPE AND STRONG COLD
FRONTAL FORCING...QUASI-LINEAR SEVERE CONVECTION WITH A TENDENCY FOR
LOW LEVEL ROTATION WILL BE A CONCERN...ESPECIALLY 02-05Z TIME FRAME
WEST OF A GARDEN CITY TO LIBERAL LINE. IF SURFACE-BASED INSTABILITY
INCREASES TO AROUND 1200 TO 1500 J/KG FARTHER NORTH INTO SOUTHWEST
KANSAS DURING THE 02-05Z TIME FRAME...THE CONCERN FOR ISOLATED
TORNADOES WILL CERTAINLY BE THERE GIVEN THE INCREDIBLE AMOUNT OF
NEAR-SURFACE SHEAR. IN FACT...JUST A QUICK GLANCE OF THE 18Z NAM
MODEL THAT JUST ROLLED IN AT 2045Z SUGGESTS A MORE OMINOUS SCENARIO
WITH SEVERE STORMS QUITE LIKELY WEST OF A DODGE CITY TO ASHLAND LINE
AS THE SURFACE WARM FRONT RACES NORTH. WILL CARRY 50 TO 60 POPS
FARTHER EAST BEYOND 06Z ACROSS PORTIONS OF SOUTHWEST, CENTRAL, SOUTH
CENTRAL KANSAS AS STRONG/SEVERE STORMS CONTINUE TO MOVE NORTHEAST IN
ADVANCE OF THE PACIFIC COLD FRONT. STORMS SHOULD EXIT THE SOUTHWEST
KANSAS REGION BEFORE DAYBREAK WITH DRIER AIRMASS ADVECTING IN FROM
COLORADO DURING THE MID TO LATE MORNING HOURS. AS DEWPOINTS FALL
RAPIDLY INTO THE LOWER 30S AND TEMPERATURES RISE INTO THE MID TO
UPPER 70S BY AFTERNOON...CRITICAL OR NEAR CRITICAL FIRE WEATHER
CONDITIONS WILL BE POSSIBLE AS WEST-SOUTHWEST WINDS OF 20 TO 30 MPH
WILL BE LIKELY.
SUNDAY THROUGH WEDNESDAY:
A WARM AND DRY SENSIBLE WEATHER SETUP IS EXPECTED AS SUSTAINED
DOWNSLOPE MID-LEVEL FLOW FROM THE WEST NORTHWEST WILL PREVAIL.
TEMPERATURES SUNDAY THROUGH TUESDAY WILL BE ABOVE AVERAGE WITH HIGHS
IN THE LOWER 80S AND LOWS IN THE LOWER TO MID 50S. A VERY STRONG
UPPER LEVEL JET WILL ENTER THE PACIFIC NORTHWEST EARLY NEXT WEEK
WITH A FAIRLY POTENT SHORTWAVE TROUGH MOVING ACROSS THE FAR NORTHERN
PLAINS/SOUTHERN CANADA PRAIRIES. COLD FRONT FROM THIS SYSTEM WILL
LIKELY PENETRATE THE CENTRAL PLAINS AROUND EARLY WEDNESDAY OF NEXT
WEEK WITH COOLER TEMPERATURES BACK TO TYPICAL OCTOBER
NUMBERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1234 AM CDT THU OCT 11 2012
MAIN CONCERN FOR 06Z TAFS IS CIGS. LOW PRESSURE LOCATED ACROSS THE LEE
OF THE ROCKIES WILL KEEP SSE WINDS IN THE FORECAST THROUGH THE OVERNIGHT
HOURS. LOW STRATUS HAS BEGUN TO CREEP CLOSER WITH PRATT REPORTING CLOSE
TO MVFR CIGS. AN INSPECTION OF PLAN VIEW RH PROGS WITHIN THE BOUNDARY
LAYER SHOW NEAR SATURATION, HOWEVER, INSPECTING BUFKIT FORECAST SOUNDINGS
SHOW LESS OF PROBLEM THAN WHAT THE HRRR IS SUGGESTING (NAMELY VIS).
ANYWAY, WILL PUT MVFR CIGS FOR KGCK/KDDC THIS MORNING. CONFIDENCE IS
LOWER FOR MVFR CIGS AT KHYS DUE TO A DRIER PROFILE. BY MID MORNING,
A DOWNSLOPE SW IS EXPECTED AHEAD OF A COLD FRONT WHICH SHOULD ALLOW
FOR VFR CIGS. THIS FRONT WILL TRAVERSE ACROSS MUCH OF THE REGION BY
THE AFTERNOON. SECOND CONCERN IS CONVECTION LATE THIS EVENING, HOWEVER,
THIS ACTIVITY SHOULD REMAIN SOUTH OF THE TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 62 61 78 / 20 40 60 20
GCK 47 59 58 75 / 10 50 70 10
EHA 50 63 51 76 / 30 70 70 0
LBL 51 65 59 78 / 30 70 70 10
HYS 45 58 58 76 / 10 30 60 20
P28 58 68 63 79 / 50 60 50 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...FINCH
LONG TERM...UMSCHEID
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
340 AM EDT THU OCT 11 2012
.SYNOPSIS...
HIGH PRESSURE PUSHING INTO THE DISTRICT THIS MORNING WITH
CLEAR SKIES AND TEMPERATURES DROPPING BELOW FREEZING ACROSS MUCH
OF THE AREA. DRY WEATHER CAN BE EXPECTED TODAY...BUT A COLD FRONT
WILL CROSS THE AREA THURSDAY NIGHT INTO FRIDAY MORNING. HIGH
PRESSURE WILL BUILD IN FOR THE EARLY PART OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL DOMINATE TODAY WITH DRY WEATHER AND MODERATING
TEMPERATURES. HIGH TEMPERATURES WILL RECOVER TO NEAR 60 BY THIS
AFTERNOON. A WEAK COLD FRONT WILL PUSH ACROSS THE DISTRICT LATE TONIGHT
INTO FRIDAY MORNING...BRINGING JUST A CHANCE OF SHOWERS DUE TO A
LACK OF MOISTURE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE COLD FRONT WILL PUSH EAST OF THE DISTRICT BY MID DAY FRIDAY
ENDING THE RISK OF SHOWERS BY AFTERNOON. ANOTHER COLD NIGHT IS
ANTICIPATED FRIDAY NIGHT BEFORE WARM ADVECTION RESUMES IN ADVANCE OF
A STRONGER COLD FRONT ACROSS THE MIDWEST. THE SHORT WAVE RIDGE IN THE
AMPLIFIED FLOW SUPPORTS A WARMER...AND STILL DRY SATURDAY...ALTHOUGH
SLIGHT CHC POPS WERE INCLUDED OVER NRN COUNTIES AS MDLS...WITH GFS
PROJECTING A MORE SRN EXTENT...SPAWN PCPN ALNG THE ADVNG LOWS WARM
FRONT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
STRATO-CU STILL HANGING ACROSS NORTHERN TERMINALS IN NW 850 FLOW
AND 850 TEMPERATURES NEAR MINUS 4C. 850 FLOW GOES ZONAL EARLY THURSDAY
AND STRATO-CU SHOULD BE ON THE WANE. CURRENTLY MORE STRATO-CU
UPSTREAM BUT HRRR AND GFS SUGGESTING AS FLOW GOES ZONAL TO
SOUTHWEST...CLOUDS NOW OVER WI ERODE AND GENERALLY LIFT NORTHWARD.
WITH GENERAL FLOW GOING SOUTHWEST TODAY... WILL JUST GO WITH
SCT050 CU AND CLEAR IT OUT TOWARD SUNSET THIS EVENING BEFORE
BRINGING IN AC AND CI TOWARD 06Z FRIDAY. WINDS DECREASING ACROSS
CWA WITH DUJ ONLY TERMINAL STILL GUSTING AT THIS TIME. EXPECT
CONTINUED DIMINISHING OVERNIGHT.
.OUTLOOK.../THURSDAY NIGHT THROUGH SUNDAY/...
WEAK FRONT APPROACHES OVERNIGHT THURSDAY INTO FRIDAY WITH MID DECK
AND CI BUT EXPECT VFR CONDITIONS. HIGH PRESSURE THEN BUILDS ACROSS
REGION THROUGH SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR PAZ016-022-023-
031-073-075.
WV...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ004-012-021-
022.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
151 AM EDT THU OCT 11 2012
.SYNOPSIS...
HIGH PRESSURE WILL APPROACH FROM THE SOUTHWEST OVERNIGHT ALLOWING
CLEARING SKIES AND TEMPERATURES DROPPING BELOW FREEZING ACROSS
MUCH OF THE AREA. THE NEXT COLD FRONT WILL CROSS THE AREA THURSDAY
NIGHT INTO FRIDAY MORNING. HIGH PRESSURE WILL BUILD IN FOR THE
EARLY PART OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCREASE
THE COVERAGE OF LAKE EFFECT STRATOCU ACROSS NORTHWEST PA.
THE LATEST RAP MID- LEVEL ANALYSIS INDICATES A BROAD 500MB TROUGH
CENTERED ACROSS THE EASTERN GREAT LAKES WITH THE UPPER OHIO VALLEY
IN A WEAK CYCLONIC TO NEAR ZONAL FLOW AT THE BASE OF THIS FEATURE.
AT THE SURFACE...A COLD FRONT HAS PUSHED WELL EAST OF THE AREA AND
COLD AIR ADVECTION IS OCCURRING WITH A WNW FLOW IN THE FRONTS
WAKE. MEANWHILE...A SURFACE HIGH IS CENTERED IN WESTERN KY. THE
PASSING TROUGH ALONG WITH WEAK COLD AIR ADVECTION ACROSS LAKE ERIE
IS PRODUCING OVERCAST STRATOCU ACROSS THE I-80 CORRIDOR.
TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS KENTUCKY AND BECOME
CENTERED OVER WEST VIRGINIA BY 12Z THURSDAY. WITH A DEEP LAYER OF
DRY AIR AND SUBSIDENCE ALOFT FROM HIGH PRESSURE BUILDING
IN...SKIES WILL BE CLEAR OVERNIGHT EVERYWHERE ASIDE FROM THE I-80
CORRIDOR. A STRONG RADIATIONAL COOLING NIGHT IS SETTING UP AS
WINDS DROP TO NEAR CALM OVERNIGHT WITH THE HIGH BUILDING IN AND
TDS IN THE UPPER 20S IN OHIO ADVECTING INTO THE AREA. WITH THIS IN
MIND...FORECAST IS CLOSER TO THE COOLER MAV GUIDANCE WITH LOWS IN
THE UPPER 20S TO LOWER 30S. THUS...A WIDESPREAD FREEZE IS EXPECTED
AND A FREEZE WARNING REMAINS IN EFFECT FOR PORTIONS OF THE AREA
THAT HAVE NOT HAD A WIDESPREAD FREEZE YET THIS FALL.
THURSDAY...A ZONAL MID-LEVEL FLOW WILL REMAIN IN PLACE WITH THE
SURFACE HIGH SHIFTING EASTWARD INTO THE DELMARVA PENINSULA. THUS...THE
LOW-LEVEL FLOW WILL SHIFT TO MORE SOUTHWESTERLY THROUGH THE DAY
AND WEAK WAA ADVECTION WILL ENSUE. WITH THE DEEP LAYER OF DRY AIR
REMAINING IN PLACE...ABUNDANT SUNSHINE WILL ALSO AID IN TEMPS
RECOVERING THROUGH THE DAY. WITH THIS IN MIND...HIGHS ARE A MAV/MET
BLEND...RANGING FROM THE MID 50S ACROSS THE EASTERN RIDGES AND I-80
CORRIDOR TO NEAR 60 IN PORTIONS OF EASTERN OHIO.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
MODELS REMAIN IN GOOD OVERALL AGREEMENT...ALBEIT WITH QUICKER
TIMING THAN PREVIOUS SOLNS...IN DEPICTIONS OF CONTINUED
PROGRESSIVE FLOW FEATURING THE APPROACH AND PASSAGE OF ANOTHER
COLD FRONT FOR THURSDAY NIGHT INTO FRIDAY MORNING...BUT WITH ONLY
SLIGHT SHRA CHCS GIVEN THE LACK OF MSTR.
BUILDING HIGH PRES IS FORECAST TO QUICKLY END ANY PCPN BY MIDDAY
FRIDAY...AND ANOTHER COLD NGT IS ANTICIPATED BEFORE WARM ADVCTN
RESUMES IN ADVN OF A STRNGER SYSTEM PROJECTED ACRS THE MIDWEST.
THE SHRTWV RIDGE IN THE AMPLIFIED FLOW SPPRTS A WARMER...AND
STILL DRY SATURDAY...ALTHOUGH SLIGHT CHC POPS WERE INCLUDED OVR
NRN COUNTIES AS MDLS...WITH GFS PROJECTING A MORE SRN EXTENT...SPAWN
PCPN ALNG THE ADVNG LOWS WARM FRONT.
SHORT TERM TEMPS WERE FORECAST USING TWEAKED SREF MEANS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
STRATO-CU STILL HANGING ACROSS NORTHERN TERMINALS IN NW 850 FLOW
AND 850 TEMPERATURES NEAR MINUS 4C. 850 FLOW GOES ZONAL EARLY THURSDAY
AND STRATO-CU SHOULD BE ON THE WANE. CURRENTLY MORE STRATO-CU
UPSTREAM BUT HRRR AND GFS SUGGESTING AS FLOW GOES ZONAL TO
SOUTHWEST...CLOUDS NOW OVER WI ERODE AND GENERALLY LIFT NORTHWARD.
WITH GENERAL FLOW GOING SOUTHWEST TODAY... WILL JUST GO WITH
SCT050 CU AND CLEAR IT OUT TOWARD SUNSET THIS EVENING BEFORE
BRINGING IN AC AND CI TOWARD 06Z FRIDAY. WINDS DECREASING ACROSS
CWA WITH DUJ ONLY TERMINAL STILL GUSTING AT THIS TIME. EXPECT
CONTINUED DIMINISHING OVERNIGHT.
.OUTLOOK.../THURSDAY NIGHT THROUGH SUNDAY/...
WEAK FRONT APPROACHES OVERNIGHT THURSDAY INTO FRIDAY WITH MID DECK
AND CI BUT EXPECT VFR CONDITIONS. HIGH PRESSURE THEN BUILDS ACROSS
REGION THROUGH SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR PAZ016-022-023-
031-073-075.
WV...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ004-012-021-
022.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1247 AM EDT THU OCT 11 2012
.SYNOPSIS...
HIGH PRESSURE WILL APPROACH FROM THE SOUTHWEST OVERNIGHT ALLOWING
CLEARING SKIES AND TEMPERATURES DROPPING BELOW FREEZING ACROSS
MUCH OF THE AREA. THE NEXT COLD FRONT WILL CROSS THE AREA THURSDAY
NIGHT INTO FRIDAY MORNING. HIGH PRESSURE WILL BUILD IN FOR THE
EARLY PART OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
06Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO INCREASE
THE COVERAGE OF LAKE EFFECT STRATOCU ACROSS NORTHWEST PA.
THE LATEST RAP MID- LEVEL ANALYSIS INDICATES A BROAD 500MB TROUGH
CENTERED ACROSS THE EASTERN GREAT LAKES WITH THE UPPER OHIO VALLEY
IN A WEAK CYCLONIC TO NEAR ZONAL FLOW AT THE BASE OF THIS FEATURE.
AT THE SURFACE...A COLD FRONT HAS PUSHED WELL EAST OF THE AREA AND
COLD AIR ADVECTION IS OCCURRING WITH A WNW FLOW IN THE FRONTS
WAKE. MEANWHILE...A SURFACE HIGH IS CENTERED IN WESTERN KY. THE
PASSING TROUGH ALONG WITH WEAK COLD AIR ADVECTION ACROSS LAKE ERIE
IS PRODUCING OVERCAST STRATOCU ACROSS THE I-80 CORRIDOR.
TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS KENTUCKY AND BECOME
CENTERED OVER WEST VIRGINIA BY 12Z THURSDAY. WITH A DEEP LAYER OF
DRY AIR AND SUBSIDENCE ALOFT FROM HIGH PRESSURE BUILDING
IN...SKIES WILL BE CLEAR OVERNIGHT EVERYWHERE ASIDE FROM THE I-80
CORRIDOR. A STRONG RADIATIONAL COOLING NIGHT IS SETTING UP AS
WINDS DROP TO NEAR CALM OVERNIGHT WITH THE HIGH BUILDING IN AND
TDS IN THE UPPER 20S IN OHIO ADVECTING INTO THE AREA. WITH THIS IN
MIND...FORECAST IS CLOSER TO THE COOLER MAV GUIDANCE WITH LOWS IN
THE UPPER 20S TO LOWER 30S. THUS...A WIDESPREAD FREEZE IS EXPECTED
AND A FREEZE WARNING REMAINS IN EFFECT FOR PORTIONS OF THE AREA
THAT HAVE NOT HAD A WIDESPREAD FREEZE YET THIS FALL.
THURSDAY...A ZONAL MID-LEVEL FLOW WILL REMAIN IN PLACE WITH THE
SURFACE HIGH SHIFTING EASTWARD INTO THE DELMARVA PENINSULA. THUS...THE
LOW-LEVEL FLOW WILL SHIFT TO MORE SOUTHWESTERLY THROUGH THE DAY
AND WEAK WAA ADVECTION WILL ENSUE. WITH THE DEEP LAYER OF DRY AIR
REMAINING IN PLACE...ABUNDANT SUNSHINE WILL ALSO AID IN TEMPS
RECOVERING THROUGH THE DAY. WITH THIS IN MIND...HIGHS ARE A MAV/MET
BLEND...RANGING FROM THE MID 50S ACROSS THE EASTERN RIDGES AND I-80
CORRIDOR TO NEAR 60 IN PORTIONS OF EASTERN OHIO.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
MODELS REMAIN IN GOOD OVERALL AGREEMENT...ALBEIT WITH QUICKER
TIMING THAN PREVIOUS SOLNS...IN DEPICTIONS OF CONTINUED
PROGRESSIVE FLOW FEATURING THE APPROACH AND PASSAGE OF ANOTHER
COLD FRONT FOR THURSDAY NIGHT INTO FRIDAY MORNING...BUT WITH ONLY
SLIGHT SHRA CHCS GIVEN THE LACK OF MSTR.
BUILDING HIGH PRES IS FORECAST TO QUICKLY END ANY PCPN BY MIDDAY
FRIDAY...AND ANOTHER COLD NGT IS ANTICIPATED BEFORE WARM ADVCTN
RESUMES IN ADVN OF A STRNGER SYSTEM PROJECTED ACRS THE MIDWEST.
THE SHRTWV RIDGE IN THE AMPLIFIED FLOW SPPRTS A WARMER...AND
STILL DRY SATURDAY...ALTHOUGH SLIGHT CHC POPS WERE INCLUDED OVR
NRN COUNTIES AS MDLS...WITH GFS PROJECTING A MORE SRN EXTENT...SPAWN
PCPN ALNG THE ADVNG LOWS WARM FRONT.
SHORT TERM TEMPS WERE FORECAST USING TWEAKED SREF MEANS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
STRATOCUMULUS ARE FADING QUICKLY POST-FRONTAL AS SUBSTANTIALLY
DRIER BOUNDARY LAYER AIR IS USHERED INTO THE REGION. WHILE THE LOW
LEVELS REMAIN FAIRLY UNSTABLE...A LACK OF MOISTURE SHOULD PRECLUDE
MUCH CLOUD FORMATION OVER THE AREA FOR THE NEXT 24 HOURS...WITH
ONE GIANT EXCEPTION. DOWN WIND OF LAKE ERIE...LAKE-INDUCED
STRATOCUMULUS WILL CONTINUE TO BLOSSOM DUE TO EXTREME LAKE EFFECT
INSTABILITY. LAKE TO 850 MB DELTA T VALUES ARE RUNNING UPWARDS OF
23C THIS EVENING...AND WHILE THESE VALUES WILL BE NARROWING AS THE
850 MB TEMPERATURES EDGE UP ON THURSDAY...LAKE EFFECT SHOWERS AND
CLOUDS DOWNWIND OF THE LAKE WILL BE COMMON. HOWEVER...CURRENT
BOUNDARY LAYER FLOW IS ONLY SLIGHTLY NORTH OF DUE WESTERLY...AND
THIS FLOW WILL BACK TOWARD WSW BY THURSDAY MORNING. AS
SUCH...SHOWERS AND CLOUDS WILL BE COMMON AROUND KFKL...BUT EDGE
NORTHWARD BY MORNING. NO OTHER SITES SHOULD BE IMPACTED BY
SHOWERS.
.OUTLOOK.../THURSDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL BE PREVALENT INTO SATURDAY...EVEN DESPITE A
WEAK FRONTAL PASSAGE ON FRIDAY THAT WILL HAVE LITTLE IMPACT ON THE
TERMINALS. THE BETTER CHANCE OF SHOWERS AND RESTRICTIONS WILL BE
ON SUNDAY WHEN THE NEXT COLD FRONT CROSSES THE REGION.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR PAZ016-022-023-
031-073-075.
WV...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ004-012-021-
022.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
542 AM EDT THU OCT 11 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF OVER
CNTRL NAMERICA. NEXT SHORTWAVE DROPPING INTO THE TROF IS CURRENTLY
HEADING SE THRU SASKATCHEWAN TOWARD SRN MANITOBA. THIS WAVE WILL BE
THE MAIN FCST ISSUE IN THE SHORT TERM. OTHERWISE...ALTHOUGH 850MB
THERMAL TROF (TEMPS OF -6 TO -8C) IS STILL CROSSING THE AREA...LAKE
EFFECT PCPN HAS BEEN GRADUALLY WINDING DOWN FROM W TO E DUE TO
SOMEWHAT DRIER AIR ADVECTING INTO THE AREA AND FLOW BECOMING MORE
ANTICYCLONIC. MORE IMPORTANT NEGATIVE FACTOR IS PROBABLY DAYTIME
HEATING DISRUPTING LAKE EFFECT PROCESSES.
LINGERING LAKE EFFECT PCPN WILL CONTINUE TO DIMINISH AND SHIFT MORE
OFFSHORE AS WINDS BACK WITH SFC HIGH PRES RIDGE PASSING. LAST OF THE
PCPN SHOULD EXIT NRN LUCE COUNTY AROUND 06Z. ATTENTION THEN TURNS TO
APPROACHING SHORTWAVE. THERE ISN`T MUCH DIFFERENCE IN MODELS...BUT
WILL FAVOR THE REGIONAL GEM WHICH HAS BEEN VERY CONSISTENT SHOWING
MORE PCPN WITH THIS SYSTEM. FAIRLY ROBUST DEEP LAYER FORCING PER
QVECTORS ALONG WITH DECENT ISENTROPIC ASCENT (285-290K SFCS)
SUGGESTS PCPN IS A GOOD BET...ESPECIALLY ACROSS THE N AND E...CLOSER
TO SHORTWAVE TRACK. PCPN SHOULD SPREAD INTO THE W LATE EVENING AND
REACH THE E OVERNIGHT. 1000-850MB THICKNESSES IN THE 1302-1310M
RANGE SUGGEST A MIX OF RAIN/SNOW WILL OCCUR. HIGH TERRAIN SHOULD BE
PREDOMINANTLY SNOW...TRANSITIONING TO MAINLY RAIN NEAR THE GREAT
LAKES. WITH 0.1 TO 0.3 INCHES OF PCPN...MAY SEE A SLUSHY INCH OR TWO
OF SNOW ACCUMULATION IN THE HIGH TERRAIN. WINDS MAY BACK JUST ENOUGH
FOR SOME LAKE ENHANCEMENT OFF LAKE MICHIGAN INTO THE FAR ERN FCST
AREA...SO PCPN AMOUNTS MAY BE HIGHER THERE. WITH LOW-LEVELS SLIGHTLY
WARMER...LAKE ENHANCED PCPN OVER THE E SHOULD BE MOSTLY IN THE FORM
OF RAIN. TEMPS WILL HAVE A BRIEF OPPORTUNITY TO FALL THIS EVENING
(SHOULD FALL BLO FREEZING IN MANY AREAS)...BUT THICKENING CLOUDS
WILL RESULT IN TEMPS RISING A LITTLE AFTER EARLY LOWS.
THERE MAY BE A BRIEF PERIOD OF NW FLOW LAKE ENHANCEMENT THU MORNING
BEFORE FORCING EXITS AND STRONG DEEP LAYER QVECTOR DIVERGENCE AND
MID LEVEL DRYING ARRIVE. THAT WILL HELP MORE WIDESPREAD PCPN LINGER
A BIT LONGER IN THE AREAS AFFECTED BY NW FLOW OFF LAKE SUPERIOR. CAA
DROPS 850MB TEMPS TO -5 TO -7C DURING THE DAY...WHICH WILL SUPPORT
SOME LAKE EFFECT PCPN. GIVEN EARLY SEASON/DIURNAL HEATING...IT WILL
BE MORE OF A HYBRID TYPE PCPN PATTERN WITH NOT SO MUCH BANDING OFF
THE LAKE...BUT ISOLD/SCT SHOWERS EXTENDING WELL INLAND.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
THURSDAY NIGHT...THE SHORTWAVE TROUGH WILL EXIT THE NRN GREAT LAKES
WITH STRONG STRONG 700-300 MB QVECTOR CONV IN ITS WAKE. AS SFC HIGH
PRES BUILDS FROM THE NRN PLAINS INTO THE UPPER MS VALLEY NW FLOW WILL
CONTINUE ACROSS LAKE SUPERIOR WITH 850 MB TEMPS INTO THE -7C TO -8C
RANGE. WITH WATER TEMPS FROM 7C TO 12C...THERE WILL BE MORE THAN
ENOUGH INSTABILITY TO SUSTAIN LAKE EFFECT PCPN. EVEN THROUGH OVERALL
WINDS WILL BE NORTHWEST...EXPECT THEAT LAKE INDUCED TROUGHING WILL
HELP TO FOCUS LOW LEVEL CONV INTO AREAS NEAR P53 AND GRAND MARAIS.
ALTHOUGH THE LONG FETCH ACROSS THE LAKE WILL KEEP TEMPS RELATIVELY
WARM OVER THE EAST...EXPECT MAINLY SNOW WITH A COATING TO HALF AN
INCH OF ACCUMULATION IN SOME LOCATIONS. OVER THE WEST...THE PCPN WILL
TAPER OFF SOONER AS THE RIDGE AND BUILDS TOWARD THE AREA WITH LIGHT
ACYC FLOW.
FRI...ANY LINGERING LAKE EFFECT PCPN INTO THE NORTHEAST CWA WILL
TAPER OFF QUICKLY IN THE MORNING AS WINDS BACK WITH THE RIDGE
BUILDING INTO THE AREA. SUNSHINE AND DEVELOPING WAA WITH SW FLOW
SHOULD HELP PUSH TEMPS INTO THE MID AND UPPER 40S...PER FCST
SOUNDINGS.
FRI NIGHT AND SAT...MODELS WERE IN GOOD AGREEMENT WITH THE OVERALL
PATTERN RESULTING IN STRONG WAA AND MOISTURE ADVECTION INTO THE
UPPER GREAT LAKES AS A STRONG SHRTWV MOVES THROUGH THE CNTRL PLAINS.
300K-310K ISENTROPIC LIFT SUPPORTED BY UPPER LEVEL DIV WITH THE
RIGHT EXIT REGION OF THE 250-300 JET OVER NRN ONTARIO WILL SUPPORT
WIDESPREAD RAIN FROM WI SPREADING INTO UPPER MI. THE NAM/SREF WAS
PREFERRED IN WITH A LATER ONSET OF PCPN AND KEEPING THE GREATER QPF
A BIT FARTHER SOUTH...CLOSER TO THE 850 MB WARM FRONT AND GREATER
ELEVATED CAPE.
SAT NIGHT INTO SUN...THE GFS...12Z GEFS AND GEM REMAINED A BIT
FARTHER NORTH WITH THE TRACK OF THE MID LEVEL SHORTWAVE AND SFC LOW
COMPARED TO THE ECMWF. SO...THERE IS GREATER UNCERTAINTY WITH THE
POSITION AND POTENTIAL FOR HEAVY PCPN ASSOCIATED WITH THE STRONG
FGEN/DEF AS THE 700 MB LOW MOVES THROUGH. WITH EITHER SCENARIO...A
COLD WIND DRIVEN RAIN MAY LINGER INTO SUNDAY WITH WRAP-AROUND PCPN
AND SOME LAKE ENHANCEMENT OFF OF LAKE SUPERIOR AS 850 MB TEMPS DROP
TO AROUND 0C.
MON-WED...MODELS WERE SIMILAR WITH A PROGRESSIVE PATTERN EARLY NEXT
WEEK BUT SHOW EXPECTED DIFFERENCES WITH DETAILS. A WAA PATTERN WITH
THE POTENTIAL FOR MORE RAIN...ESPECIALLY FROM TUE NIGHT INTO
WED...PER MDLS CONSENSUS. TEMPS ARE EXPECTED CLIMB BACK VALUES AOA
SEASONAL AVERAGES.
&&
FOR THE EXTENDED...
ISSUED AT 541 AM EDT THU OCT 11 2012
MODELS ARE STILL IN FAIRLY GOOD AGREEMENT IN THE PLACEMENT OF A
MID/UPPER LEVEL RIDGE OVER THE PLAINS THROUGH THE DAY FRIDAY...WITH
THE ASSOCIATED SURFACE HIGH PRESSURE DOMINATING THE UPPER GREAT
LAKES REGION THROUGH SATURDAY. THIS WILL KEEP DRY WEATHER WITH
PREDOMINATE LIGHT N/NERLY WINDS THROUGH THIS TIME PERIOD.
SUNNY/PARTLY CLOUDY SKIES WILL KEEP TEMPERATURES FAIRLY STEADY /AT
OR SLIGHTLY BELOW NORMAL/...WITH COOLEST TEMPERATURES NEAR LAKE
SUPERIOR DUE TO NORTHERLY WINDS OFF THE LAKE.
MODEL CONSENSUS ALSO SHOWS A SHORTWAVE DEVELOPING ON THE BACKSIDE OF
THE RIDGE...HOWEVER DISAGREEMENTS COME IN TO PLAY ON THE PATH THIS
SHORTWAVE WILL TAKE. GFS AND GEM SOLUTIONS HAVE THE SHORTWAVE
DEVELOPING OVER THE PLAINS ON SATURDAY...THEN GETTING PUSHED TO THE
SOUTHEAST UNDER THE INFLUENCE OF THE HIGH PRESSURE RIDGE AND DRY AIR
ALREADY IN PLACE. THIS SOLUTION SEEMS THE MOST REASONABLE. ECMWF
SOLUTION ON THE OTHER HAND CONTINUES TO BE MORE AGGRESSIVE WITH THIS
SYSTEM...MOVING IT NORTHEAST ALONG THE BACKSIDE OF THE RIDGE AND
REACHING THE UPPER GREAT LAKES BY SATURDAY AFTERNOON. WITH THE
GFS/GEM...UPPER MI SHOULD REMAIN DRY. HOWEVER WILL KEEP SLIGHT
CHANCES NEAR THE WI BORDER SATURDAY AFTERNOON...SPREADING FURTHER
INLAND SATURDAY NIGHT AND SUNDAY TO ACCOUNT FOR ECMWF SOLUTION. WITH
THE INCREASE IN CLOUD COVER ASSOCIATED WITH THIS SYSTEM...EXPECT LOW
TEMPERATURES SAT NIGHT TO BE SLIGHTLY WARMER THAN PREVIOUS...BUT
STILL HOVERING ON THE FREEZING LINE...SO SNOW COULD MIX IN WITH RAIN
IN AFFECTED AREAS. PRECIP SHOULD DISSIPATE BY SUNDAY NIGHT AS
SHORTWAVE MOVES TO THE SOUTHEAST AND HIGH PRESSURE BEGINS TO BUILD
IN FROM CANADA THROUGH THE DAY MONDAY.
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1205 AM EDT THU OCT 11 2012
A DISTURBANCE WILL QUICKLY MOVE INTO THE AREA OVERNIGHT. EXPECT A
PERIOD OF MVFR CONDITIONS AS -SN/-RA SPREAD ACROSS THE AREA. PCPN
SHOULD BE MAINLY SN AT KCMX/KSAW. PCPN WILL DIMINISH/END LATE
TONIGHT/THU MORNING...BUT MVFR CIGS MAY LINGER THRU THE MORNING AT
KCMX/KSAW BEFORE COMING VFR IN THE AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 541 AM EDT THU OCT 11 2012
EXPECT NW GALES TO 35 KTS TO DEVELOP THIS AFTERNOON OVER THE E HALF
OF THE LAKE AS COLDER AIR FOLLOWS A VIGOUROUS DISTURBANCE PASSING
INTO SE CANADA AND ALLOWS EFFICIENT MIXING OVER THE RELATIVELY WARM
LAKE WATERS OF STRONGER WINDS JUST ABOVE THE SURFACE. LIGHTER WINDS
WILL THEN PREVAIL TONIGHT THRU FRI AS A HI PRES RIDGE/WEAKER PRES
GRADIENT FOLLOWS INTO THE UPPER LAKES. STRONGER S WINDS UP 25 TO 30
KTS MAY IMPACT MAINLY THE E HALF ON SAT AS A SHARPER PRES GRADIENT
BETWEEN THE DEPARTING HI AND LO PRES MOVING NE FROM THE PLAINS
DEVELOPS OVER THE AREA. AS THE LO PRES CENTER MOVES TO THE E JUST S
OF UPPER MI EARLY SUN...LOOK FOR THE WINDS TO BACK TO THE N AND
INCREASE UP TO 25 TO 30 KTS...ESPECIALLY OVER THE E HALF. THE
APPROACH OF HI PRES ON MON WILL CAUSE A STEADY DECREASE IN WIND
SPEED LATER SUN INTO MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
LSZ249>251-266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
EXTENDED...
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1205 AM EDT THU OCT 11 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW A TROF OVER
CNTRL NAMERICA. NEXT SHORTWAVE DROPPING INTO THE TROF IS CURRENTLY
HEADING SE THRU SASKATCHEWAN TOWARD SRN MANITOBA. THIS WAVE WILL BE
THE MAIN FCST ISSUE IN THE SHORT TERM. OTHERWISE...ALTHOUGH 850MB
THERMAL TROF (TEMPS OF -6 TO -8C) IS STILL CROSSING THE AREA...LAKE
EFFECT PCPN HAS BEEN GRADUALLY WINDING DOWN FROM W TO E DUE TO
SOMEWHAT DRIER AIR ADVECTING INTO THE AREA AND FLOW BECOMING MORE
ANTICYCLONIC. MORE IMPORTANT NEGATIVE FACTOR IS PROBABLY DAYTIME
HEATING DISRUPTING LAKE EFFECT PROCESSES.
LINGERING LAKE EFFECT PCPN WILL CONTINUE TO DIMINISH AND SHIFT MORE
OFFSHORE AS WINDS BACK WITH SFC HIGH PRES RIDGE PASSING. LAST OF THE
PCPN SHOULD EXIT NRN LUCE COUNTY AROUND 06Z. ATTENTION THEN TURNS TO
APPROACHING SHORTWAVE. THERE ISN`T MUCH DIFFERENCE IN MODELS...BUT
WILL FAVOR THE REGIONAL GEM WHICH HAS BEEN VERY CONSISTENT SHOWING
MORE PCPN WITH THIS SYSTEM. FAIRLY ROBUST DEEP LAYER FORCING PER
QVECTORS ALONG WITH DECENT ISENTROPIC ASCENT (285-290K SFCS)
SUGGESTS PCPN IS A GOOD BET...ESPECIALLY ACROSS THE N AND E...CLOSER
TO SHORTWAVE TRACK. PCPN SHOULD SPREAD INTO THE W LATE EVENING AND
REACH THE E OVERNIGHT. 1000-850MB THICKNESSES IN THE 1302-1310M
RANGE SUGGEST A MIX OF RAIN/SNOW WILL OCCUR. HIGH TERRAIN SHOULD BE
PREDOMINANTLY SNOW...TRANSITIONING TO MAINLY RAIN NEAR THE GREAT
LAKES. WITH 0.1 TO 0.3 INCHES OF PCPN...MAY SEE A SLUSHY INCH OR TWO
OF SNOW ACCUMULATION IN THE HIGH TERRAIN. WINDS MAY BACK JUST ENOUGH
FOR SOME LAKE ENHANCEMENT OFF LAKE MICHIGAN INTO THE FAR ERN FCST
AREA...SO PCPN AMOUNTS MAY BE HIGHER THERE. WITH LOW-LEVELS SLIGHTLY
WARMER...LAKE ENHANCED PCPN OVER THE E SHOULD BE MOSTLY IN THE FORM
OF RAIN. TEMPS WILL HAVE A BRIEF OPPORTUNITY TO FALL THIS EVENING
(SHOULD FALL BLO FREEZING IN MANY AREAS)...BUT THICKENING CLOUDS
WILL RESULT IN TEMPS RISING A LITTLE AFTER EARLY LOWS.
THERE MAY BE A BRIEF PERIOD OF NW FLOW LAKE ENHANCEMENT THU MORNING
BEFORE FORCING EXITS AND STRONG DEEP LAYER QVECTOR DIVERGENCE AND
MID LEVEL DRYING ARRIVE. THAT WILL HELP MORE WIDESPREAD PCPN LINGER
A BIT LONGER IN THE AREAS AFFECTED BY NW FLOW OFF LAKE SUPERIOR. CAA
DROPS 850MB TEMPS TO -5 TO -7C DURING THE DAY...WHICH WILL SUPPORT
SOME LAKE EFFECT PCPN. GIVEN EARLY SEASON/DIURNAL HEATING...IT WILL
BE MORE OF A HYBRID TYPE PCPN PATTERN WITH NOT SO MUCH BANDING OFF
THE LAKE...BUT ISOLD/SCT SHOWERS EXTENDING WELL INLAND.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 450 PM EDT WED OCT 10 2012
THURSDAY NIGHT...THE SHORTWAVE TROUGH WILL EXIT THE NRN GREAT LAKES
WITH STRONG STRONG 700-300 MB QVECTOR CONV IN ITS WAKE. AS SFC HIGH
PRES BUILDS FROM THE NRN PLAINS INTO THE UPPER MS VALLEY NW FLOW WILL
CONTINUE ACROSS LAKE SUPERIOR WITH 850 MB TEMPS INTO THE -7C TO -8C
RANGE. WITH WATER TEMPS FROM 7C TO 12C...THERE WILL BE MORE THAN
ENOUGH INSTABILITY TO SUSTAIN LAKE EFFECT PCPN. EVEN THROUGH OVERALL
WINDS WILL BE NORTHWEST...EXPECT THEAT LAKE INDUCED TROUGHING WILL
HELP TO FOCUS LOW LEVEL CONV INTO AREAS NEAR P53 AND GRAND MARAIS.
ALTHOUGH THE LONG FETCH ACROSS THE LAKE WILL KEEP TEMPS RELATIVELY
WARM OVER THE EAST...EXPECT MAINLY SNOW WITH A COATING TO HALF AN
INCH OF ACCUMULATION IN SOME LOCATIONS. OVER THE WEST...THE PCPN WILL
TAPER OFF SOONER AS THE RIDGE AND BUILDS TOWARD THE AREA WITH LIGHT
ACYC FLOW.
FRI...ANY LINGERING LAKE EFFECT PCPN INTO THE NORTHEAST CWA WILL
TAPER OFF QUICKLY IN THE MORNING AS WINDS BACK WITH THE RIDGE
BUILDING INTO THE AREA. SUNSHINE AND DEVELOPING WAA WITH SW FLOW
SHOULD HELP PUSH TEMPS INTO THE MID AND UPPER 40S...PER FCST
SOUNDINGS.
FRI NIGHT AND SAT...MODELS WERE IN GOOD AGREEMENT WITH THE OVERALL
PATTERN RESULTING IN STRONG WAA AND MOISTURE ADVECTION INTO THE
UPPER GREAT LAKES AS A STRONG SHRTWV MOVES THROUGH THE CNTRL PLAINS.
300K-310K ISENTROPIC LIFT SUPPORTED BY UPPER LEVEL DIV WITH THE
RIGHT EXIT REGION OF THE 250-300 JET OVER NRN ONTARIO WILL SUPPORT
WIDESPREAD RAIN FROM WI SPREADING INTO UPPER MI. THE NAM/SREF WAS
PREFERRED IN WITH A LATER ONSET OF PCPN AND KEEPING THE GREATER QPF
A BIT FARTHER SOUTH...CLOSER TO THE 850 MB WARM FRONT AND GREATER
ELEVATED CAPE.
SAT NIGHT INTO SUN...THE GFS...12Z GEFS AND GEM REMAINED A BIT
FARTHER NORTH WITH THE TRACK OF THE MID LEVEL SHORTWAVE AND SFC LOW
COMPARED TO THE ECMWF. SO...THERE IS GREATER UNCERTAINTY WITH THE
POSITION AND POTENTIAL FOR HEAVY PCPN ASSOCIATED WITH THE STRONG
FGEN/DEF AS THE 700 MB LOW MOVES THROUGH. WITH EITHER SCENARIO...A
COLD WIND DRIVEN RAIN MAY LINGER INTO SUNDAY WITH WRAP-AROUND PCPN
AND SOME LAKE ENHANCEMENT OFF OF LAKE SUPERIOR AS 850 MB TEMPS DROP
TO AROUND 0C.
MON-WED...MODELS WERE SIMILAR WITH A PROGRESSIVE PATTERN EARLY NEXT
WEEK BUT SHOW EXPECTED DIFFERENCES WITH DETAILS. A WAA PATTERN WITH
THE POTENTIAL FOR MORE RAIN...ESPECIALLY FROM TUE NIGHT INTO
WED...PER MDLS CONSENSUS. TEMPS ARE EXPECTED CLIMB BACK VALUES AOA
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1205 AM EDT THU OCT 11 2012
A DISTURBANCE WILL QUICKLY MOVE INTO THE AREA OVERNIGHT. EXPECT A
PERIOD OF MVFR CONDITIONS AS -SN/-RA SPREAD ACROSS THE AREA. PCPN
SHOULD BE MAINLY SN AT KCMX/KSAW. PCPN WILL DIMINISH/END LATE
TONIGHT/THU MORNING...BUT MVFR CIGS MAY LINGER THRU THE MORNING AT
KCMX/KSAW BEFORE COMING VFR IN THE AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EDT WED OCT 10 2012
ATTENTION OVER THE NEXT 24HRS IS ON LOW PRES WHICH WILL BE MOVING
ACROSS OR JUST N OF LAKE SUPERIOR LATE TONIGHT AND THU MORNING.
STRONGEST WINDS THRU EARLY THIS EVENING WILL BE OVER ERN LAKE
SUPERIOR WHERE NW WINDS WILL BE GUSTING TO 30KT WITH A FEW GUSTS TO
GALE FORCE. WINDS WILL BRIEFLY BE IN THE 15-25KT RANGE FOR A TIME
TONIGHT BEFORE INCREASING AGAIN LATE AS THE LOW ARRIVES IN THE UPPER
LAKES. SW WINDS MAY GUST TO NEAR 30KT LATE TONIGHT. OF MORE CONCERN
WILL BE THE NW WINDS DEVELOPING THU AS THE LOW SHIFTS E OF THE LAKE.
AIDED BY INCREASINGLY COLDER AIR AND PRES RISES APPROACHING FROM THE
NW...A PERIOD OF NW GALES IS A POSSIBILITY OVER THE E HALF OF LAKE
SUPERIOR. MAY NEED TO HOIST A GALE WARNING IF NEW GUIDANCE ARRIVING
THIS EVENING MORE SOLIDLY SUPPORTS GALES.
A MODERATELY STRONG LOW PRESSURE SYSTEM IS EXPECTED TO TRACK THROUGH
THE WESTERN GREAT LAKES. SOUTH WINDS OF 15 TO 25 KNOTS ARE EXPECTED
AHEAD OF THE SYSTEM SATURDAY WHILE NORTHERLY 15 TO 25 KNOT WINDS ARE
WILL DEVELOP AS THE LOW PULLS AWAY SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
LSZ249>251-266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
342 AM CDT THU OCT 11 2012
.SHORT TERM...
ISSUED AT 311 AM CDT THU OCT 11 2012
(TODAY THROUGH FRIDAY NIGHT)
WARM ADVECTION UNDER WAY OVER SOUTHWEST MISSOURI AT THIS TIME.
CLOUD DECK BETWEEN 5000-8000FT IS MOVING SLOWLY NORTHEAST TOWARD OUR
AREA. CLOUDS SHOULD OVERSPREAD CENTRAL MISSOURI BY LATE MORNING AND
ON INTO EASTERN MISSOURI EARLY IN THE AFTERNOON. EVEN THOUGH PRECIP
HAS YET TO DEVELOP...SHORT-RANGE MODELS CONTINUE TO PRINT OUT PRECIP
DUE TO THE STRONG WARM ADVECTION AND MOISTURE CONVERGENCE ON THE
850MB BAROCLINIC ZONE ACROSS SOUTHERN MISSOURI. FORECAST SOUNDINGS
ARE PRETTY STRONGLY CAPPED THOUGH SO WOULD EXPECT THAT PRECIP WILL
BE PRETTY SCATTERED. HRRR DEVELOPS ISOLATED TO WIDELY SCATTERED
PRECIP...SO THIS JIVES WELL WITH THAT THINKING. WARM ADVECTION WILL
CONTINUE TONIGHT OVER SOUTHERN MISSOURI AND A SUBTLE SHORTWAVE WILL
BRING ANOTHER CANADIAN HIGH AND A SHOT OF COOL AIR DOWN FROM THE
NORTHERN PLAINS INTO MISSOURI TO REINFORCE THE BAROCLINIC ZONE. THE
STRONG BAROCLINICITY AND CONTINUING LOW LEVEL JET COMBINED WITH THE
SHORTWAVE PASSING OVERHEAD SHOULD PRODUCE MORE WIDESPREAD RAIN AND
THUNDERSTORMS. THE LOW LEVEL JET AND MOISTURE CONVERGENCE STAYS
FOCUSED OVER SOUTHERN MISSOURI...SO HAVE BACKED DOWN TO CHANCE POPS
ALONG THE I-70 CORRIDOR TONIGHT BUT KEPT LIKELY DOWN OVER THE
OZARKS. LOW LEVEL JET CHANGES FOCUS TO THE GREAT PLAINS ON FRIDAY
WHICH SHOULD BRING THE RAIN OVER SOUTHEAST MISSOURI TO AN END. THE
AFOREMENTIONED CANADIAN HIGH MOVES OVER THE MID ATLANTIC FRIDAY
NIGHT WHICH TURNS LOW LEVEL FLOW TO THE SOUTH. THIS PUSHES A WARM
FRONT UP THROUGH OUR AREA INTO THE UPPER MIDWEST SETTING THE STAGE
FOR A WARM SATURDAY AND POTENTIALLY SEVERE WEATHER SATURDAY NIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 340 AM CDT THU OCT 11 2012(SATURDAY THROUGH WEDNESDAY)
WE SHOULD BE WELL INTO THE WARM SECTOR ON SATURDAY. NAM AND GFS
SHOW 14-16C AT 850MB SATURDAY AFTERNOON SO AM GOING AT OR ABOVE
UPPER RANGE OF GUIDANCE TEMPS. THE SYNOPTIC SETUP REMAINS
FAVORABLE FOR SEVERE WEATHER SATURDAY AFTERNOON AND NIGHT. THE
DETAILS IN THE MODELS ARE VERY SIMILAR AND HAVE BEEN VERY
CONSISTENT. DEEP LAYER SHEAR IN EXCESS OF 50KTS WITH A STRONG
SHORTWAVE AND LOW LEVEL MOISTURE WILL BE IN PLACE. CONVECTION LOOKS
TO DEVELOP OVER EASTERN KANSAS AND SHOULD MOVE INTO MISSOURI DURING
THE LATE AFTERNOON. FOR OUR AREA...BEST CHANCE FOR STORMS WILL BE
SATURDAY NIGHT. DAY 3 SEVERE OUTLOOK COVERS ALL OF CENTRAL AND
NORTHEAST MISSOURI AS WELL AS PARTS OF THE STL METRO. STILL...MODE
AND SEVERITY OF CONVECTION WILL LIKELY BE DECIDED BY AMOUNT OF
AVAILABLE INSTABILITY. STAY TUNED.
COLD FRONT ASSOCIATED WITH THE STORM WILL MOVE THROUGH SUNDAY
MORNING. COULD SEE SOME LINGERING SHOWERS AHEAD OF THE FRONT...BUT
IT LOOKS LIKE DRY AIR WILL SHUT THE PRECIP OFF SO WILL KEEP POPS OUT
OF THE FORECAST EXCEPT FOR EXTREME EASTERN ZONES FOR NOW. TEMPS
WILL COOL FROM SATURDAY`S HIGHS...BUT THE REALLY COLD AIR WILL STAY
LOCKED UP IN CANADA THIS TIME AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE WESTERN HALF OF THE U.S. WARM AND DRY CONDITIONS WILL CONTINUE
MONDAY AND TUESDAY UNDER THE INFLUENCE OF THE RIDGE. TEMPS SHOULD
BE AT OR ABOVE NORMAL IN THE 70S. NEXT CHANCE FOR RAIN WILL COME
WEDNESDAY AS ANOTHER SHORTWAVE DIPS INTO THE UPPER MIDWEST WHICH
WILL ALLOW THE LOW LEVEL JET TO RAMP UP OVER THE AREA AHEAD OF A
COLD FRONT.
CARNEY
&&
.AVIATION...
ISSUED AT 1145 PM CDT WED OCT 10 2012
SC OVER N OK/NW AR HAS BEGUN ITS NWD PUSH EARLY THIS EVENING...AND
00Z NAM/GFS REMAIN IN FAIRLY GOOD AGREEMENT THAT VFR CIGS 4-6KFT
WILL MOVE INTO MID MO AFTER 12-14Z TIME FRAME...AND THEN
SPREAD EAST TO THE MISSISSIPPI RIVER BY MIDDAY/EARLY AFTERNOON.
NAM CONTINUES TO SUGGEST CIGS LOWERING WELL INTO MVFR CAT A FEW
HOURS AFTER THE ARRIVAL OF THE 4-6KFT DECK...BUT FOR NOW HAVE
DELAYED THIS A BIT AND HAVE NOT GONE QUITE AS
PESSIMISTIC...LOWERING CIGS TO AROUND 3KFT BY EARLY EVENING ALONG
THE I-70 CORRIDOR. WHILE SOME VERY LIGHT PRECIP CANNOT TOTALLY BE
RULED OUT...CERTAINLY APPEARS THAT BEST COVERAGE WILL BE S OF TAF
SITES SO HAVE KEPT FORECAST DRY FOR NOW.
SPECIFICS FOR KSTL...LITTLE IF ANY CLOUDINESS EXPECTED
OVERNIGHT...BUT INCREASING S FLOW SHOULD ADVECT 6KFT CIGS INTO
THE AREA BY AROUND MIDDAY THURSDAY. THESE CIGS SHOULD GRADUALLY
LOWER...AND MAY APPROACH HIGH END MVFR BY 06Z/12.
TRUETT
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 47 66 57 / 20 40 10 10
QUINCY 66 39 63 52 / 10 10 5 50
COLUMBIA 64 44 66 57 / 20 40 20 20
JEFFERSON CITY 63 46 66 57 / 20 40 20 20
SALEM 62 46 64 52 / 10 40 10 10
FARMINGTON 58 48 65 55 / 30 60 20 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
312 AM CDT THU OCT 11 2012
.SHORT TERM...
ISSUED AT 311 AM CDT THU OCT 11 2012
(TODAY THROUGH FRIDAY NIGHT)
WARM ADVECTION UNDER WAY OVER SOUTHWEST MISSOURI AT THIS TIME.
CLOUD DECK BETWEEN 5000-8000FT IS MOVING SLOWLY NORTHEAST TOWARD OUR
AREA. CLOUDS SHOULD OVERSPREAD CENTRAL MISSOURI BY LATE MORNING AND
ON INTO EASTERN MISSOURI EARLY IN THE AFTERNOON. EVEN THOUGH PRECIP
HAS YET TO DEVELOP...SHORT-RANGE MODELS CONTINUE TO PRINT OUT PRECIP
DUE TO THE STRONG WARM ADVECTION AND MOISTURE CONVERGENCE ON THE
850MB BAROCLINIC ZONE ACROSS SOUTHERN MISSOURI. FORECAST SOUNDINGS
ARE PRETTY STRONGLY CAPPED THOUGH SO WOULD EXPECT THAT PRECIP WILL
BE PRETTY SCATTERED. HRRR DEVELOPS ISOLATED TO WIDELY SCATTERED
PRECIP...SO THIS JIVES WELL WITH THAT THINKING. WARM ADVECTION WILL
CONTINUE TONIGHT OVER SOUTHERN MISSOURI AND A SUBTLE SHORTWAVE WILL
BRING ANOTHER CANADIAN HIGH AND A SHOT OF COOL AIR DOWN FROM THE
NORTHERN PLAINS INTO MISSOURI TO REINFORCE THE BAROCLINIC ZONE. THE
STRONG BAROCLINICITY AND CONTINUING LOW LEVEL JET COMBINED WITH THE
SHORTWAVE PASSING OVERHEAD SHOULD PRODUCE MORE WIDESPREAD RAIN AND
THUNDERSTORMS. THE LOW LEVEL JET AND MOISTURE CONVERGENCE STAYS
FOCUSED OVER SOUTHERN MISSOURI...SO HAVE BACKED DOWN TO CHANCE POPS
ALONG THE I-70 CORRIDOR TONIGHT BUT KEPT LIKELY DOWN OVER THE
OZARKS. LOW LEVEL JET CHANGES FOCUS TO THE GREAT PLAINS ON FRIDAY
WHICH SHOULD BRING THE RAIN OVER SOUTHEAST MISSOURI TO AN END. THE
AFOREMENTIONED CANADIAN HIGH MOVES OVER THE MID ATLANTIC FRIDAY
NIGHT WHICH TURNS LOW LEVEL FLOW TO THE SOUTH. THIS PUSHES A WARM
FRONT UP THROUGH OUR AREA INTO THE UPPER MIDWEST SETTING THE STAGE
FOR A WARM SATURDAY AND POTENTIALLY SEVERE WEATHER SATURDAY NIGHT.
CARNEY
&&
.AVIATION...
ISSUED AT 1145 PM CDT WED OCT 10 2012
SC OVER N OK/NW AR HAS BEGUN ITS NWD PUSH EARLY THIS EVENING...AND
00Z NAM/GFS REMAIN IN FAIRLY GOOD AGREEMENT THAT VFR CIGS 4-6KFT
WILL MOVE INTO MID MO AFTER 12-14Z TIME FRAME...AND THEN
SPREAD EAST TO THE MISSISSIPPI RIVER BY MIDDAY/EARLY AFTERNOON.
NAM CONTINUES TO SUGGEST CIGS LOWERING WELL INTO MVFR CAT A FEW
HOURS AFTER THE ARRIVAL OF THE 4-6KFT DECK...BUT FOR NOW HAVE
DELAYED THIS A BIT AND HAVE NOT GONE QUITE AS
PESSIMISTIC...LOWERING CIGS TO AROUND 3KFT BY EARLY EVENING ALONG
THE I-70 CORRIDOR. WHILE SOME VERY LIGHT PRECIP CANNOT TOTALLY BE
RULED OUT...CERTAINLY APPEARS THAT BEST COVERAGE WILL BE S OF TAF
SITES SO HAVE KEPT FORECAST DRY FOR NOW.
SPECIFICS FOR KSTL...LITTLE IF ANY CLOUDINESS EXPECTED
OVERNIGHT...BUT INCREASING S FLOW SHOULD ADVECT 6KFT CIGS INTO
THE AREA BY AROUND MIDDAY THURSDAY. THESE CIGS SHOULD GRADUALLY
LOWER...AND MAY APPROACH HIGH END MVFR BY 06Z/12.
TRUETT
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 47 66 57 / 20 40 10 10
QUINCY 66 39 63 52 / 10 10 5 50
COLUMBIA 64 44 66 57 / 20 40 20 20
JEFFERSON CITY 63 46 66 57 / 20 40 20 20
SALEM 62 46 64 52 / 10 40 10 10
FARMINGTON 58 48 65 55 / 30 60 20 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1223 AM CDT THU OCT 11 2012
...UPDATE TO AVIATION...
.UPDATE...
A FEW CHANGES HAVE BEEN MADE TO THE FORECAST FOR THE OVERNIGHT AND
THURSDAY MORNING PERIODS.
FIRST OFF...CURRENT TEMPERATURES ACROSS MUCH OF THE FORECAST AREA
ARE NEARING PREVIOUSLY FORECASTED LOWS. MOSTLY CLEAR SKIES...LIGHT
WINDS...AND DEW POINTS WELL DOWN IN THE 30S HAVE RESULTED IN
TEMPERATURES DROPPING OFF VERY QUICKLY THIS EVENING. INCREASING
WINDS FROM THE SOUTH ALONG WITH INCREASING CLOUDS WILL STEADY
TEMPERATURES OFF LATER TONIGHT ACROSS THE EASTERN OZARKS...WITH
TEMPERATURES LIKELY RISING ACROSS WESTERN MISSOURI AND
SOUTHEASTERN KANSAS. NEVERTHELESS...LOWS OVER MOST LOCATIONS WERE
BUMPED DOWN A CATEGORY.
THE SECOND TWEAK TO THE FORECAST WAS TO ADD A SLIGHT CHANCE FOR
THUNDER IN FOR LATE TONIGHT ACROSS SOUTHWESTERN MISSOURI AND
SOUTHEASTERN KANSAS. BOTH THE 00Z NAM AND RAP INDICATE LITTLE
CONVECTIVE INHIBITION LATE TONIGHT FOR SOURCE PARCELS IN THE 800
TO 700 MB LAYER. THESE MODELS ALSO INDICATE THAT ISENTROPIC
UPGLIDE WILL OVERSPREAD THIS GENERAL AREA LATE TONIGHT AS A LOW
LEVEL JET NOSES IN FROM THE SOUTHWEST. GENERALLY KEPT POPS IN THE
SLIGHT CHANCE RANGE FOR NOW AS REGIONAL RAOBS INDICATE THAT THERE
IS WORK TO BE DONE TO OVERCOME A CAPPING INVERSION CENTERED AROUND
750 MB. WE THEN WENT WITH SLIGHTLY HIGHER POPS ACROSS SOUTHERN
MISSOURI FOR THURSDAY MORNING. OTHERWISE...THE SETUP STILL LOOKS
DECENT FOR AT LEAST PATCHY DRIZZLE AS LOW LEVEL MOISTURE SURGES UP
FROM THE SOUTH.
SCHAUMANN
&&
.SHORT TERM (TONIGHT THROUGH SATURDAY)...
THE FORECAST FOR THE NEXT SEVERAL DAYS LOOKS TO BE A BIT OF A MESS
WITH THE POTENTIAL FOR DRIZZLE...RAIN AND THUNDERSTORMS SOME OF
WHICH COULD BE STRONG TO SEVERE.
FOR THE REMAINDER OF TODAY HOWEVER...THE REGION WILL SEE SUNNY
SKIES AND COOL AFTERNOON TEMPERATURES. THIS IS THE RESULT OF
CANADIAN HIGH PRESSURE OVER THE REGION. THE COOL TEMPERATURES ARE
EXPECTED TO REMAIN THROUGH TONIGHT ACROSS CENTRAL MISSOURI AS THE
HIGH PRESSURE SLIDES EAST WITH OVERNIGHT LOW FALLING INTO THE
UPPER 30S.
FOR SOUTHWESTERN MISSOURI AND SOUTHEASTERN KANSAS...SOUTHERLY
FLOW IS EXPECTED TO BEGIN OVERNIGHT AS THE HIGH PRESSURE MOVES
EAST. FAIRLY STRONG WARM AIR AND MOISTURE ADVECTION WILL BE
ONGOING AFTER MIDNIGHT ACROSS THE WESTERN PORTION OF THE AREA AND
KEEP OVER NIGHT LOW TEMPERATURES IN THE LOWER 40S. THE STRENGTH
OF THE MOISTURE AND WARM AIR ADVECTION COMBINED WITH 30KTS OF
ISENTROPIC UPGLIDE...NOTED ON THE NAM...ACROSS THE REGION WILL
PRODUCE PRECIPITATION ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST
STARTING AROUND 09Z. THE SHALLOW NATURE OF THE MOISTURE
HOWEVER...ALL BELOW 700MB AND A CAPPING INVERSION...WOULD INDICATE
DRIZZLE AND SHOWERS SHOULD BE MAIN CONCERN. THIS WILL CONTINUE
INTO THE MIDDLE OF THE DAY WITH LIGHT SHOWERS AND DRIZZLE BEING
MODERATE AT TIMES.
A COLD FRONT WILL SLIDE SOUTH ACROSS THE OZARKS THURSDAY NIGHT
INTO FRIDAY AND FINALLY STALL ACROSS THE MISSOURI/ARKANSAS STATE
LINE. THIS WILL PROVIDE THE FOCUS FOR SHOWERS AND SCATTERED
THUNDERSTORMS FROM LATE THURSDAY NIGHT THROUGH FRIDAY EVENING.
CURRENT MODELS ARE INDICATING SOME DECENT LAPSE RATES AND
INSTABILITY WITH THE FRONT THURSDAY NIGHT. THIS WILL ALLOW FOR THE
DEVELOPMENT OF SOME SCATTERED STRONG TO SEVERE STORMS MAINLY ALONG
AND SOUTH OF INTERSTATE 44. CURRENT INDICATION ARE FOR THE
STRONGEST STORMS TO BE CAPABLE OF PRODUCING HAIL TO QUARTER SIZE
AND LOCALIZED DOWNBURST WINDS.
SHOWERS AND STORMS SHOULD REMAIN SCATTERED INTO MIDDAY FRIDAY AS
THE FRONT BRIEFLY SLIDES SOUTH IN ADVANCE OF A STRONG STORM SYSTEM
THAT BEGINS TO SWING OUT OF THE SOUTHWESTERN CONUS AND INTO THE
CENTRAL PLAINS.
HATCH
&&
.LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...
BIGGEST FORECAST CHALLENGE FOR LATE SATURDAY AND SATURDAY NIGHT IS
THE POTENTIAL FOR SEVERE THUNDERSTORMS. HIGHLY ENERGETIC STORM
SYSTEM WILL LIFT OUT OF THE CENTRAL ROCKIES AND MOVE TOWARD THE
UPPER MIDWEST/WESTERN GREAT LAKES REGION WITH A NEUTRAL TILT
ORIENTATION. THERE WILL NO DOUBT BE STRONG WIND FIELDS ASSOCIATED
WITH THIS SYSTEM...A 50 KT LOW LEVEL JET...70+ KT MID LEVEL
JET...A 100 KT UPPER LEVEL JET...AND DEEP LAYER SHEAR IN EXCESS OF
60KT. HOWEVER...INSTABILITY VALUES REMAIN A CONCERN. THE DEPTH OF
MOISTURE RETURN IS IN QUESTION...THOUGH SURFACE DEWPOINT VALUES
IN THE 60F TO 65F RANGE ALONG/AHEAD OF THE SURGING COLD FRONT
SHOULD YIELD A NARROW BAND OF 500 TO 1000 J/KG OF MLCAPE BY LATE
AFTERNOON SATURDAY FROM WESTERN IOWA SOUTHWESTWARD THROUGH NORTH
CENTRAL TEXAS. 12Z MODEL OUTPUT HAS ONCE AGAIN SLOWED THE
PROGRESSION OF THIS SYSTEM A BIT...WITH TIME OF ARRIVAL MORE SO
IN THE SATURDAY EVENING TIME FRAME FOR THE OUTLOOK AREA. AS A
RESULT...LOSS OF DAYTIME HEATING WILL AT LEAST CAP...IF NOT LIMIT
INSTABILITY VALUES A LITTLE.
NEVERTHELESS...STRONG FORCING WILL HELP YIELD A LINEAR STORM MODE
ALONG THE COLD FRONT AS IT MOVES INTO THE REGION. HIGH SHEAR...LOW
CAPE ENVIRONMENT SUGGESTS STRAIGHT LINE WIND AS A PRIMARY RISK...
WHICH IS FURTHER SUPPORTED BY VERY STRONG WIND FIELDS JUST OFF THE
SURFACE. THE RISK FOR HAIL/TORNADOES IS IN QUESTION AND IT WILL
MOST LIKELY REQUIRE OBSERVING HOW MESOSCALE CONDITIONS UNFOLD TO
HONE IN ON ANY RISK. FOR NOW...CANNOT RULE IT OUT...BUT WOULD LIKE
TO SEE MORE IN THE WAY OF MLCAPE AS WELL AS LOW LEVEL CAPE.
CERTAINLY THIS SYSTEM BEARS WATCHING.
FROM SUNDAY NIGHT THROUGH EARLY TUESDAY...QUIET WEATHER IS
EXPECTED AS SHORTWAVE RIDGING ALOFT BRIEFLY TAKES HOLD IN AN
INCREASING ACTIVE UPPER LEVEL PATTERN. TEMPERATURES WILL BE AROUND
AVERAGE DURING THIS TIME FRAME. FROM LATE TUESDAY THROUGH THE
MIDDLE OF NEXT WEEK...MEDIUM RANGE MODEL OUTPUT CONTINUES TO
SUGGEST ANOTHER FRONTAL PASSAGE AND CHANCE FOR RAINFALL.
TEMPERATURES LOOK TO REMAIN SEASONABLY MILD.
GAGAN
&&
.AVIATION...
CEILINGS WILL CONTINUE TO LOWER OVERNIGHT AND INTO THURSDAY
MORNING AS MOISTURE INCREASES FROM THE SOUTH. WE HAVE DELAYED MVFR
ONSET A FEW HOURS BUT ARE STILL EXPECTING IT TO COME INTO SOUTHERN
MISSOURI AROUND SUNRISE. WE ARE ALSO EXPECTING PATCHY DRIZZLE TO
DEVELOP...WHICH MAY CAUSE SLIGHT REDUCTION TO VISIBILITY. THERE IS
ALSO A LOW PROBABILITY FOR A THUNDERSTORM OR TWO TO DEVELOP AROUND
SUNRISE AS A LOW LEVEL JET STREAM SHIFTS INTO THE REGION. DID NOT
INCLUDE THIS THREAT IN THE TAFS DUE TO LOW CONFIDENCE. THE LOW
LEVEL JET STREAM WILL ALSO RESULT IN LOW LEVEL WIND SHEAR THURSDAY
MORNING. MVFR CEILINGS ARE THEN EXPECTED TO PERSIST FOR MUCH OF
THE DAY ON THURSDAY WITH PERHAPS SOME PARTIAL CLEARING LATE IN THE
DAY. SHOWERS AND THUNDERSTORMS ALONG WITH MVFR CONDITIONS ARE THEN
EXPECTED TO DEVELOP THURSDAY EVENING AS A COLD FRONT DROPS SOUTH
INTO SOUTHERN MISSOURI.
SCHAUMANN
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1148 PM MDT WED OCT 10 2012
.AVIATION...
06Z TAF CYCLE
NO NOTABLE AVIATION HAZARDS OVERNIGHT FOR NW TWO THIRDS OF FCST
AREA...HOWEVER AS OF JUST BEFORE MIDNIGHT PATCHY MVFR CATEGORY
CIGS SLOWLY EXPANDING ACROSS FAR SE PLAINS. AS MOIST LOW LEVEL FLOW
CONTINUES ACROSS SE AND E CENTRAL PLAINS THIS WILL ENCOURAGE
EXPANSION OF MVFR TO LOCALLY IFR CIGS AND PERHAPS A FEW FOG PATCHES
THROUGH THE EARLY AND MID MORNING HOURS IN AREAS SE OF A LINE FROM
ROUGHLY KTCC TO RUIDOSO. TAF SITES THAT THESE LOW CIGS AND POSS FOG
ARE MOST LIKELY TO AFFECT INCLUDE KROW AND PERHAPS KTCC. THERE IS
A SLIGHT CHANCE THAT AFTER DAWN AND THROUGH GOOD PORTION OF THU
MORN...BUT MORE LIKELY LATE THU...THERE MAY BE SOME MT TOP
OBSCURATIONS ACROSS THE S CENTRAL MTS. ALSO A FEW GUSTY TSRA ARE
POSSIBLE S OF A LINE FROM QUEMADO TO KLVS TO KTCC AFTER 20Z
THU...BUT MOSTLY JUST -SHRA ARE EXPECTED DURING DAYLIGHT HOURS
THU. SPOTTY TSRA WILL BE MORE LIKELY LATER THU NIGHT OVER A LARGER
AREA. 43
&&
.PREV DISCUSSION...955 PM MDT WED OCT 10 2012...
REMOVED POPS THRU THE EARLY MORNING HOURS ACROSS MUCH OF THE SW
MTS AND THE SE PLAINS PER LATEST RUC13 AND 00Z NAM12 SOLUTIONS. 03Z
SATELLITE IMAGERY IS BEGINNING TO SHOW LOW CLOUD DEVELOPMENT OVER
FAR SE NM WHERE LOW LEVEL MOISTURE ADVECTION IS SURGING NW INTO THE
AREA. BUFKIT PROFILES DO FAVOR SOME THICK LOW CLOUDS AND PATCHY FOG
DEVELOPMENT FOR THE PECOS RIVER VALLEY AND SE PLAINS.
SW FLOW AHEAD OF A DEEP UPPER LOW OVER SOCA IS SHOWING SIGNS OF
MOISTENING FROM SOUTH TO NORTH TOWARD NM HOWEVER PRECIP WILL LIKELY
HOLD OFF UNTIL AROUND SUNRISE. ALSO MADE CHANGES TO HIGHEST POPS
FOR THURSDAY THRU FRIDAY MORE IN LINE WITH HPC PROBABILISTIC QPF
GRIDS AND THE LATEST NAM. THE OVERALL SCENARIO REMAINS ON TRACK.
EXPECT THE MOST ACTIVE PERIOD OF PRECIP FROM EARLY FRIDAY MORNING
THRU FRIDAY AFTERNOON AS SIGNIFICANT UPPER DIVERGENCE ALLOWS AN
AREA OF RAIN/STORMS TO DEVELOP ACROSS THE STATE AND SHIFT NORTHEAST
THRU THE DAY WHILE THE PACIFIC FRONT APPROACHES FROM THE WEST. STRONG
TO POTENTIALLY SEVERE STORMS ARE POSSIBLE TOWARD THE TX STATE LINE
FRIDAY. GUYER
&&
.PREV DISCUSSION...307 PM MDT WED OCT 10 2012...
CURRENTLY...RIDGE ALOFT EXTENDING FROM THE TEXAS BIG BEND COUNTRY
SQUARELY ACROSS NEW MEXICO TO GREAT SALT LAKE...AHEAD OF LARGE
WEATHER SYSTEM COILED UP OFF POINT CONCEPCION IN SOUTHERN
CALIFORNIA EN ROUTE TO THE SAN DIEGO AREA. AT THE
SURFACE...STATIONARY BOUNDARY LYING FROM TAOS TO WHITE SANDS
MISSILE RANGE STANDS AS LAST GASP FOR COLD FRONT WHICH DIPPED INTO
THE EASTERN PLAINS OVER THE LAST 24 HOURS. ADVANCING STORM SYSTEM
TOUCHING OFF LIGHTNING STRIKES ACROSS SOUTHERN NEVADA AND SOUTHERN
UTAH...AND ALL THIS IS HEADING FOR NEW MEXICO OVER THE NEXT 48 HOURS.
MODELS...IN GOOD AGREEMENT THROUGH THE UPCOMING WEEKEND AND INTO
NEXT WORK WEEK...WITH SOME MODEST DIFFERENCES EMERGING FROM
TUESDAY ONWARD IN THE DETAILS WITHIN BROADER AGREEMENT ON THE
GENERAL THEME. PLAUSIBLE AND ACCEPTED CONSENSUS MOVES CALIFORNIA
CLOSED LOW TO SAN DIEGO LATE THURSDAY NIGHT AND TO THE FOUR
CORNERS BY FRIDAY AFTERNOON. SYSTEM WILL EJECT RAPIDLY TO THE
PLATTE RIVER VALLEY OF CENTRAL NEBRASKA BY SATURDAY MIDDAY AND
RAPIDLY INTO THE WESTERN GREAT LAKES BY SUNDAY MORNING. EJECTION
SPEED WILL VEER FLOW ALOFT RAPIDLY TO THE NORTHWEST DURING THE DAY
ON SATURDAY...AND SOME FORM OF NORTHWEST FLOW IS IN THE CARDS FOR
NEW MEXICO THROUGH MIDWEEK NEXT WEEK AS RIDGE CORE SETS UP OVER
THE TROPICAL EAST PACIFIC. FROM TUESDAY ONWARD...DOMESTIC GFS
SOLUTION PREFERS A MORE LAMINAR AND STEADY NORTHWEST FLOW RUNNING
JUST NORTH OF NEW MEXICO...WHILE EUROPEAN COLLEAGUES AT ECMWF DIG
BROAD TROUGH OUT OF THE CANADIAN PRAIRIES ACROSS NEW MEXICO TO THE
GULF OF CALIFORNIA...AND THEN MOVES THIS TROUGH INTO THE SOUTHERN
PLAINS BY MIDWEEK. UPSHOT FOR NEW MEXICO WOULD BE A CLOUDIER DAY
WITH SOME ENHANCED SHOWER CHANCES TUESDAY UNDER THE ECMWF
SOLUTION...WITH A DRY AND COOL DAY FOR THE GFS. ECMWF HAS BEEN
DIGGING THESE TROUGHS INTO THE SOUTHWEST FOR THE LAST SEVERAL
STORMS THAT HAVE COME THROUGH...BUT THESE HAVE NOT VERIFIED AS
DEEPLY AS THE ECMWF SOLUTION WOULD SUGGEST. WILL THUS KEEP A LEAN
TOWARD GFS IN THE EXTENDED PERIODS FOR NOW AND AWAIT A BETTER
CONSENSUS IN FUTURE RUNS.
OVERNIGHT...REASONABLY SEASONABLE OVERNIGHT TEMPERATURES
TONIGHT...WITH FREEZES MOSTLY OVER THE NORTHERN MOUNTAINS AND MORE
MILD TEMPERATURES ELSEWHERE. AS RIDGE BREAKS DOWN AND SHIFTS
EASTWARD...SOME ISOLATED THUNDERSTORMS REMAIN A POSSIBILITY OVER
THE SOUTHEAST CORNER OF THE STATE...AS THE FIRST OF THE SOUTHWEST
WINDS CIRCULATING ABOUT THE APPROACHING WEATHER SYSTEM PUSH SOME
DYNAMICAL HELP OVER THE EXISTING MOISTURE. OUTSIDE OF CONVECTIVE
SHOWERS...SOME VISIBILITY REDUCTIONS IN PATCHY FOG ARE POSSIBLE
TOWARDS DAYBREAK...ESPECIALLY NEAR THE TEXAS PANHANDLE ALONG AND
SOUTH OF INTERSTATE 40.
FOR THURSDAY...STORM CENTER APPROACHING SAN DIEGO THURSDAY MORNING
WILL DRIFT INTO THE IMPERIAL AND MOJAVE DESERT COUNTRY OF INLAND
SOUTHERN CALIFORNIA BY THURSDAY EVENING. DIFFLUENT SOUTHWEST FLOW
ACROSS NEW MEXICO WILL EXPAND CLOUD AND SHOWER COVERAGE RAPIDLY
THROUGH THE DAY...WITH HEAVIER SHOWERS SETTING UP OVER THE EAST
CENTRAL PLAINS BY THURSDAY AFTERNOON. SHOWER COVERAGE WILL EXPAND
IN COVERAGE AND INCREASE IN INTENSITY THURSDAY NIGHT...WITH
HEAVIER RAINFALL BUILDING ACROSS THE ARIZONA AND COLORADO LINES IN
THE NORTH AND WEST...AND MORE WIDESPREAD SHOWERS ON TAP FOR THE
EAST. WARM MOIST AIR MOVING INTO THE PLAINS WILL BRING DAYTIME
HIGH TEMPERATURES BACK UP ABOVE NORMAL...WITH NEAR NORMAL
TEMPERATURES IN THE WEST. ADDED CLOUD COVER AND RAINFALL WILL KEEP
OVERNIGHT LOWS MILD.
FOR FRIDAY...THE MAIN EVENT PLAYING OUT...AS STORM CENTER MOVES
FROM SOUTHEAST CALIFORNIA TO THE FOUR CORNERS. SOUTHWEST WINDS
WILL GET AN EARLY BOOST IN SPEEDS IN THE WEST FRIDAY MORNING WITH
GUSTY WINDS SPREADING TO CENTRAL PORTIONS BY MIDDAY AND EXPANDING
INTO THE NORTHEAST PLAINS BY LATE AFTERNOON. FORECAST WINDS
CURRENTLY CROSSING ADVISORY THRESHOLDS BY MID AFTERNOON WITH
SPEEDS TAPERING OFF THROUGH FRIDAY EVENING. A WET DAY IN THE
CARDS...WITH HEAVIEST RAINFALL OVER THE NORTHEAST PLAINS AND
ADJACENT HIGHLANDS THROUGH FRIDAY EVENING. RAPIDLY DEEPENING
SURFACE TROUGH ALONG THE NEW MEXICO EASTERN BORDER WILL SET UP
SURFACE CONVERGENCE...AND WITH AMPLE DYNAMICS IN
PLACE...THUNDERSTORMS NEAR THE TEXAS PANHANDLE FRIDAY AFTERNOON
MAY RUN TO THE STRONG WIDE WITH HAIL AND POSSIBLY DAMAGING WIND.
AND THATS NOT ALL...AS COLDER AIR MOVING IN OVER THE NORTHERN
MOUNTAINS MAY CHANGE RAIN OVER TO AN INCH OR TWO OF WET SNOW
OVERNIGHT FOR THE SAN JUAN...SANGRE DE CRISTO...AND JEMEZ SUMMITS
AND HIGH COUNTRY SLOPES...WITH SOME LESSER AMOUNTS OVER THE
CHUSKAS AND SOME OF THE HIGHER SPOTS ON THE CONTINENTAL DIVIDE.
ACCUMULATIONS WILL BE VISIBLE BUT NOT ESPECIALLY LARGE...WITH SNOW
GETTING A LATE START OVERNIGHT AND FALLING ON RELATIVELY WARM
SURFACES.
FOR SATURDAY...STORM CENTER MOVING RAPIDLY TO NORTHEAST COLORADO
SATURDAY MORNING AND TO THE MISSOURI RIVER VALLEY BY SATURDAY
AFTERNOON. COLD FRONT BARRELING SOUTHWARD IN WAKE OF THE STORM
WILL KEEP DAYTIME HIGH TEMPERATURES 3 TO 8 DEGREES BELOW NORMAL
CENTRAL AND WEST...AND NEAR NORMAL IN THE EXTREME EAST. SHOWER
COVERAGE AND SKIES WILL CLEAR RAPIDLY FROM SOUTHWEST TO NORTHEAST
DURING THE DAY WITH BREEZES CONTINUING OVER THE CENTRAL MOUNTAIN
CHAIN SUMMITS...AND ALONG THE INTERSTATE 40 CORRIDOR ACROSS THE
EASTERN PLAINS.
OUTLOOK...SUNDAY THROUGH TUESDAY...NORTHWEST FLOW MOVING FROM
NORTHERN CALIFORNIA ACROSS THE NORTHEAST HALF OF NEW MEXICO AND
INTO THE DEEP SOUTH SUNDAY WILL CLEAR SKIES AND ALLOW MODEST
WARMING TREND TO TAKE HOLD FOR THE WORK WEEK START...AS SURFACE HIGH
PRESSURE BUILDS INTO THE NORTHWEST HALF OF NEW MEXICO. WARMING
WILL BRING TEMPERATURES 6 TO 12 DEGREES ABOVE NORMAL OVER THE
EASTERN PLAINS...WITH TEMPERATURES CLOSER TO NORMAL CENTRAL AND
WEST. COLD FRONT DROPPING SOUTHWARD WILL RUN TO THE WEAK SIDE AND
LEVEL OFF TEMPERATURES ON MONDAY. COOLER AIR IN PLACE FOR
TUESDAY...WITH SOME AFTERNOON BREEZES DEVELOPING ONCE AGAIN OVER
THE EASTERN SLOPES AND ADJACENT PLAINS OF THE CENTRAL MOUNTAIN
CHAIN TUESDAY AFTERNOON. SPEEDY FLOW CLIPPING NORTHERN NEW MEXICO
MAY KICK OFF SOME EVENING SPRINKLES OR FLURRIES OVER THE HIGH
PEAKS LATE TUESDAY NIGHT. SHY
.FIRE WEATHER...
A CHANGE IN CONDITIONS FROM WARM AND DRY TO A MORE ACTIVE PATTERN
IS EXPECTED THURSDAY AND FRIDAY.
A SHORT WAVE RIDGE IS CURRENTLY POSITIONED OVER NEW MEXICO WITH
ABOVE NORMAL TEMPERATURES ACROSS CENTRAL AND WESTERN ZONES AND SOME
COOLER TEMPERATURES ACROSS THE EASTERN PLAINS IN THE WAKE OF A COLD
FRONT. SOME BREEZY AFTERNOON WINDS WILL PERSIST THROUGH EARLY
EVENING AS RH VALUES DIP BELOW 20 PERCENT ACROSS THE WEST. OVERNIGHT
RH RECOVERIES AREA EXPECTED TO BE FAIR ACROSS MUCH OF CENTRAL AND
WESTERN ZONES WITH GOOD TO EXCELLENT VALUES ACROSS THE EAST. LOW
CLOUDS...SOME FOG WITH A SLIGHT CHANCE FOR SOME WETTING RAIN IS
INTRODUCED INTO THE SOUTHEAST PLAIN TONIGHT.
A NEARLY STATIONARY UPPER LEVEL LOW POSITIONED OFF THE CALIFORNIA
COAST IS PROGGED TO MOVE ONSHORE BY LATE THURSDAY. SOUTHWEST FLOW
IN ADVANCE OF THE SYSTEM WILL SUPPORT STRENGTHENING SOUTH TO
SOUTHWEST WINDS ON THURSDAY...ESPECIALLY OVER THE WEST. CHANCES FOR
WETTING RAIN INCREASE AS WELL. VENTILATION INCREASES TO VERY GOOD TO
EXCELLENT MOST ZONES AND TEMPERATURES REBOUND ACROSS THE EAST.
THERE IS REASONABLY GOOD AGREEMENT ON THE TRACK OF THE UPPER LOW
THURSDAY INTO FRIDAY...WITH A SLOW PROGRESSION EAST AND SOUTH ON
THURSDAY WITH BEST JET...LIFT AND MOISTURE AHEAD OF THE SYSTEM.
HOWEVER...MODELS CAN STRUGGLE WITH THE SPEED OF THE UPPER LOW AND
SOME DRY AIR AHEAD OF THE LOW WILL MAKE THE FORECAST A LITTLE TRICKY
AS WELL. MODELS MOVE THE UPPER LOW TO THE NORTHEAST ON FRIDAY WITH A
TIGHT GRADIENT AND STRONG JET OVER NEW MEXICO. WINDS SHOULD BE THE
STRONGEST ON FRIDAY...WITH A SIGNIFICANT WIND EVENT POSSIBLE...BUT
CURRENT GRIDS MAINTAIN RH WELL ABOVE CRITICAL VALUES. THE BEST
CHANCES FOR WETTING RAIN LOOK TO BE THE NORTH AND EXTREME EAST WHERE
STRONG THUNDERSTORMS ARE POSSIBLE.
MODELS MOVE THE LOW MORE RAPIDLY TO THE NORTHEAST ON SATURDAY...WITH
THE LOW CENTERED NEAR OR OVER NEBRASKA BY MIDDAY. UNDER DEVELOPING
NORTHWEST FLOW ALOFT...COOLER AND MUCH DRIER AIR FILTERS IN OVER THE
STATE.
WARMER AND MOSTLY DRIER CONDITIONS CONTINUE INTO SUNDAY WITH
A WEAKENING GRADIENT AND MUCH LIGHTER WINDS. VENTILATION VALUES LOOK
TO BE POOR TO FAIR.
EXTENDED MODELS MAINTAIN NORTHWEST FLOW AT LEAST THROUGH MID WEEK
WITH DRY AND SEASONABLE WARM TEMPERATURES EXPECTED. 05
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
43
AREA FORECAST DISCUSSION
NWS NORMAN OK
1240 AM CDT THU OCT 11 2012
.AVIATION...
RAPID MOISTURE RETURN HAS LEAD TO WIDESPREAD LOW CLOUDS THIS
MORNING. MVFR/IFR CIGS ARE EXPECTED TO PERSIST THROUGH MOST OF THE
TAF PERIOD AT ALL BUT KGAG AND KWWR. ISOLD DZ/-SHRA WILL BE
POSSIBLE...PRIMARILY AFTER 08Z FROM KSPS AND KLAW...NNEWD TO KOKC
AND KPNC. HOWEVER...LITTLE IMPACT TO VSBYS IS EXPECTED. EXPECT BKN
MVFR CIGS TO LINGER INTO THE AFTERNOON TOMORROW AT MOST TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 851 PM CDT WED OCT 10 2012/
UPDATE...
ONLY MINOR TWEAKS TO TONIGHTS GRIDS. STILL APPEARS THERE IS AN
OUTSIDE CHANCE FOR SOME LATE NIGHT SHOWERS OR PERHAPS A
THUNDERSTORM. OTHERWISE MILD NIGHT AS CLOUD COVER OVERSPREADS THE
AREA AND LOW LEVEL MOISTURE BEGINS TO INCREASE WITH THE RETURN OF
SOUTH WINDS. NO UPDATES AT THIS TIME.
PREV DISCUSSION... /ISSUED 631 PM CDT WED OCT 10 2012/
DISCUSSION...
PLEASE SEE THE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
MOSTLY MVFR DUE TO LOW CIGS WILL PREVAIL THROUGH AT LEAST THE
OVERNIGHT HOURS FOR A MAJORITY OF THE TERMINALS. THE WINDS WILL
BEGIN TO SHIFT FROM THE SOUTH LATE TONIGHT AND EARLY TOMORROW
MORNING...INCREASING TO AROUND 15 TO 20KT BY TOMORROW AFTERNOON.
VFR MAY RETURN AT PNC..WWR..AND GAG AROUND 12-18Z...BUT THE OTHER
TERMINALS MAY NOT EXPERIENCE THESE IMPROVED CONDITIONS UNTIL AFTER
18Z.
PREV DISCUSSION... /ISSUED 335 PM CDT WED OCT 10 2012/
DISCUSSION...
STRATUS CONTINUES TO SPREAD NORTH ACROSS THE AREA AND EXPECT
OVERCAST SKIES AREAWIDE BY MID-LATE EVENING. HRRR HAS SOME SIGNAL
THAT CLEARING OVER CENTRAL TEXAS NOW MAY SPREAD INTO NORTH TEXAS
ZONES LATE TONIGHT... BUT MOST SIGNAL IS FOR STRATUS PERSISTANCE
OR REDEVELOPMENT WITH THIS LOW-LEVEL MOISTURE ADVECTION... SO WILL
JUST KEEP THE OVERCAST SKIES THROUGHOUT. MAY SEE SOME LIGHT
SHOWERS DEVELOP OVERNIGHT AS LOW-LEVEL MOISTURE INCREASES.
STORM CHANCES INCREASE THURSDAY NIGHT AND PERSIST THROUGH AT LEAST
SATURDAY AS EXPECTED WITH /A/ THE ARRIVAL OF A COLD FRONT MOVING
SOUTH THROUGH THE CENTRAL PLAINS IN RESPONSE TO A STORM SYSTEM
SWINGING THROUGH THE GREAT LAKES.. AND /B/ THE STORM SYSTEM
CURRENTLY ON THE SOUTHERN CALIFORNIA COAST MOVING TOWARD THE
PLAINS. NO REAL SIGNIFICANT CHANGE IN THE EXPECTATIONS FROM THE
PREVIOUS FORECAST WITH THIS SYSTEM... SO HAVE ONLY MADE MINOR
CHANGES TO THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 80 65 83 66 / 20 40 50 30
HOBART OK 80 64 81 62 / 20 40 40 50
WICHITA FALLS TX 84 67 85 68 / 20 20 20 30
GAGE OK 84 58 75 61 / 20 40 50 70
PONCA CITY OK 81 61 76 66 / 20 60 50 50
DURANT OK 82 65 85 66 / 20 20 20 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/84/84
AREA FORECAST DISCUSSION
NWS TULSA OK
1150 PM CDT WED OCT 10 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
CEILINGS WILL CONTINUE TO LOWER OVERNIGHT WITH WIDESPREAD MVFR
CONDITIONS DEVELOPING 09-12Z AND CONTINUING THROUGH AT LEAST 18Z
THU. ISOLATED SHOWERS OR THUNDERSTORMS POSSIBLE OVERNIGHT BUT
LIMITED COVERAGE PRECLUDES MENTION IN TAFS AND IMPACTS UNLIKELY TO
CAUSE REDUCTION IN FLIGHT CATEGORY. GRADUAL IMPROVEMENT TO VFR
SHOULD OCCUR BY 21Z...WITH MORE SIGNIFICANT THUNDERSTORM CHANCES
HOLDING OFF UNTIL JUST AFTER END OF FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 933 PM CDT WED OCT 10 2012/
..UPDATE...
DISCUSSION...
ELEVATED MOISTURE RETURN IS UNDERWAY THIS EVENING EVIDENT WITH
EXPANDING STRATUS DECK WHILE ELEVATED WARM FRONTAL ZONE WORKS
NORTHWARD PER AREA 88D VWP DATA. 00Z KOUN/KSGF SOUNDINGS SAMPLE
BOTH THE MOISTURE LAYER /KOUN/ AND THE EDGE OF THE WEAKER CAPPING
ALOFT /KSGF/. THIS MOIST LAYER HEIGHT ALIGNS WELL WITH KSRX VWP
FRONTAL DEPTH AND SUPPORTS SHORT TERM MODEL SOLUTIONS OF
GENERATING LIGHT PRECIP LATER TONIGHT AS MOISTURE SPREADS
EASTWARD. LATEST LOCAL WRF / HRRR RUNS FAVOR E/SE AREAS OF THE
FORECAST AREA FOR BULK OF LATE NIGHT PRECIP WITH INSTABILITY IN
PLACE TO WARRANT A FEW THUNDERSTORMS. HRRR LIGHTNING FORECASTS
ALSO SUPPORT THIS TREND WITH ANY THUNDERSTORM LIKELY DEVELOPING
MORE TOWARD SUNRISE AND AFTERWARD. HAIL WILL BE POSSIBLE WITH MOST
ANY SUSTAINED UPDRAFT THOUGH THE RISK OF SEVERE CRITERIA HAIL
LOOKS VERY LOW THROUGH THE REMAINDER OF TONIGHT. UPDATED FORECAST
WILL ADJUST WX GRIDS AND SKY COVER TRENDS. FAR NE OK HAS COOLED
QUICKLY PRIOR TO LOW CLOUD ARRIVAL..BUT THIS TREND SHOULD STEADY
SOON. TEMPS ADJUSTMENTS WERE SLIGHTLY DOWN FOR FAR NE OK AND
SLIGHTLY UPWARD ELSEWHERE GIVEN THICK CLOUD BLANKET.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...14
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1153 PM CDT WED OCT 10 2012
.DISCUSSION...
SEE THE 06Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
MVFR LIKELY BETWEEN 08Z AND 15Z. OTHERWISE...THE 700 MB TROUGH
THAT WAS OVERHEAD NEAR THE COAST SHOULD SLOWLY MOVE NORTHWARD
TONIGHT AND THURSDAY. THE GFS AND NAM BOTH INDICATE RAIN CHANCES
DURING THE AFTERNOON AFTER 21Z. THE THINKING HERE IS THAT BEST
CHANCES WILL BE OVER THE WESTERN HALF...AND WILL GO WITH A VCTS AT
BOTH KCLL AND KUTS AFTER 21Z.
40
&&
.PREV DISCUSSION... /ISSUED 925 PM CDT WED OCT 10 2012/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
RELATIVELY DEEP MOISTURE COUPLED WITH A WEAK 850 TROUGH PRODUCED
SCATTERED SHRA/TSRA THIS AFTN AND EVENING. AM EXPECTING SHRA/TSRA
TO END IN THE NEXT 30 MINUTES OR SO. A FEW OF THE STORMS PRODUCED
SOME HEFTY (3 TO 4 INCHES) RAINFALL TOTALS OVER THE SW ZONES THIS
EVENING. GLS IS ALREADY BELOW FCST VALUES SO WILL TWEAK MIN TEMP
GRIDS A BIT BUT OVERALL FCST FOR TONIGHT IS ON TRACK. T/TD SPREAD
IS NARROWING SO FEEL PATCHY FOG WILL AGAIN BE POSSIBLE. 43
PREV DISCUSSION... /ISSUED 650 PM CDT WED OCT 10 2012/
DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
AVIATION...
A STATIONARY FRONT STRETCHED ACROSS THE NORTHERN PART OF SE TX
EARLY THIS EVENING...WHILE THE 22Z RUC MODEL SHOWED THAT A
SHORTWAVE TROUGH WAS MOVING OVER THE AREA. ISOLATED SHOWERS AND
THUNDERSTORMS THAT DEVELOPED EARLIER...MOST OUTSIDE OF THE
TERMINAL FORECAST SITES AND VICINITY AREAS...SHOULD DIMINISH BY
03Z. HOWEVER..WILL DO FREQUENT CHECKS FOR ANY NEEDED UPDATES.
OTHERWISE...THERE IS GOOD CONFIDENCE IN THE VFR CONDITIONS
BECOMING MVFR BETWEEN 06Z AND 11Z. DIMINISHING WINDS IN THE
BOUNDARY LAYER AS WELL AS A DEVELOPING LOW-LEVEL INVERSION SHOULD
AID IN DEVELOPMENT OF A CLOUD DECK...WHILE FOG IS POSSIBLE
ESPECIALLY AT KLBX. EXPECT THESE CONDITIONS TO IMPROVE BACK TO
VFR BY 15Z.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 70 89 69 89 69 / 10 10 10 0 10
HOUSTON (IAH) 71 89 70 88 71 / 10 10 10 0 10
GALVESTON (GLS) 76 84 75 84 77 / 10 10 10 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
924 AM MDT THU OCT 11 2012
.UPDATE...FRONT SEEMS TO BE ACROSS NORTHERN FRINGES OF ADAMS
COUNTY...BASED ON SURFACE OBSERVATIONS AND LAPS SURFACE ANALYSIS.
FRONT TO CONTINUE TO MOVE ACROSS REMAINDER OF PLAINS DURING THE
MORNING HOURS WITH WINDS BECOMING MORE EASTERLY BY THE AFTERNOON.
AIRMASS TO BE SLIGHTLY COOLER ACROSS PLAINS BEHIND FRONT...WITH
THE COOLER AIR OVER NORTHEAST CORNER. OTHERWISE...ONLY A SLIGHT
CHANCE FOR SHOWERS OVER THE MOUNTAINS LATER THIS AFTERNOON AS
LATEST RUC INDICATE MODEST INSTABILITY AND SOME CAPE.
OVERALL...CURRENT FORECAST LOOK ON TRACK...THOUGH MAY NEED TO
ADJUST WIND AND TEMP GRIDS ACROSS PLAINS GIVEN CURRENT
CONDITIONS.
&&
.SHORT TERM...
.AVIATION...FRONT APPEARS TO BE MOVING ACROSS THE NORTHERN
SECTIONS OF ADAMS COUNTY...THOUGH NOT QUITE INTO THE DIA AREA.
FRONT SHOULD BE MOVING ACROSS DIA WITHIN THE NEXT HALF HOUR.
CURRENT TAF TRENDS STILL LOOKING GOOD...BUT DID DELAY THE ONSET OF
THE GUSTS AN HOUR BASED ON UPSTREAM OBSERVATIONS. MAY ALSO NEED TO
ADJUST WINDS AT KBJC.
&&
.PREV DISCUSSION... /ISSUED 304 AM MDT THU OCT 11 2012/
SHORT TERM...SCATTERED HIGH WAVE CLOUDS STILL MOVING ACROSS THE
FORECAST AREA AS HIGH LEVEL MOISTURE IS STREAMING OVERHEAD THROUGH
THE RIDGE ALOFT. THE RIDGE AXIS IS PROGGED TO MOVE FROM
SOUTHWESTERN CO TO THE NORTHEAST CORNER OF THE STATE BY TONIGHT AS
A CUTOFF LOW MOVES INTO THE SOUTHERN GREAT BASIN. FORECASTED
SYNTHETIC SATELLITE IMAGES SHOW THE HIGH WAVE CLOUDS DECREASING
EARLY THIS MORNING...THEN REFORMING MID-MORNING AND INTO THE
AFTERNOON. HAVE ADDED THIS TO THE GRIDS AS HINTS OF IT ARE ALREADY
FORMING OVER SOUTHERN COLORADO.
A COLD FRONT CURRENTLY OVER NORTHERN NEBRASKA SHOULD CONTINUE TO
MOVE SOUTH AND INTO COLORADO JUST AROUND SUNRISE. THE POST FRONTAL
AIRMASS WILL BE MUCH COOLER...THOUGH NO MOISTURE WITH IT SO NO
POPS ARE MENTIONED. HAVE TRENDED MAX TEMPERATURES DOWN A FEW
DEGREES OVER THE PLAINS FOR TODAY WITH THE ANTICIPATED HIGH CLOUDS
AROUND FOR TODAY AS WELL AS THE COLD FRONT AFFECTING THE
NORTHEAST AND EASTERN PLAINS. THE DEPTH OF THE COLD FRONT LOOKS TO
REACH UP TO 9000 FEET OR LESS...KEEPING THE HIGHER TERRAIN OUT OF
THE STABLE AIRMASS. A SMALL AMOUNT OF INSTABILITY AND A SLIGHT
INCREASE IN MOISTURE WILL ALLOW FOR A SLIGHT CHANCE OF SHOWERS AND
A THUNDERSTORM OR TWO OVER THE HIGH MOUNTAINS THIS AFTERNOON.
TONIGHT WILL SEE AN INCREASE IN CLOUDS FROM THE SOUTH AS THE LOW
MOVES CLOSER. A FEW SHOWERS WILL BE POSSIBLE OVER THE MOUNTAINS
SOUTH OF I70 AFTER MIDNIGHT. NO ACCUMULATIONS ARE EXPECTED.
TEMPERATURES OVER THE PLAINS WILL BE COOLER THAN LAST NIGHT WITH A
SMALL CHANCE FOR PATCHY FOG OVER THE NORTHERN URBAN CORRIDOR.
LONG TERM...ATTENTION CONTINUES TO FOCUS ON UPPER LEVEL LOW
WHICH WILL MOVE ACROSS THE DESERT SOUTHWEST AND APPROACH SOUTHERN
UTAH BY FRIDAY EVENING AND THEN ACROSS WESTERN COLORADO FRIDAY
NIGHT. Q-G VERTICAL MOTION INCREASES AHEAD OF THIS FEATURE...AS
WELL AS MID AND UPPER LEVEL MOISTURE. AT THE SAME TIME...LOW LEVEL
MOISTURE IS ALSO PROGGED TO GET DRAWN INTO THIS SYSTEM FROM TEXAS
AS SOUTHERLY SURFACE WINDS INCREASE ACROSS THE HIGH PLAINS. THE
RESULT WILL BE AN INCREASINGLY MOIST AND UNSTABLE AIRMASS WITH A
COUPLE HUNDRED JOULES OF CAPE AVAILABLE BY AFTERNOON. WITH THE
LARGE SCALE Q-G VERTICAL MOTION ADVERTISED...WE SHOULD BE ABLE TO
GENERATE NUMEROUS SHOWERS OVER THE MOUNTAINS AND A FEW
THUNDERSTORMS AS WELL. AIRMASS IS INITIALLY VERY WARM SO ANY SNOW
ACCUMULATION TOMORROW SHOULD BE CONFINED TO ELEVATIONS ABOVE 11-12
THOUSAND FEET. ON THE PLAINS...SHOWER/STORM COVERAGE WILL BE MORE
LIMITED GIVEN SOUTHWEST FLOW ALOFT AND DOWNSLOPING COMPONENT ABOVE
THE BOUNDARY LAYER. NONETHELESS...WE SHOULD STILL SEE CONVECTIVE
ACTIVITY WITH LIFT AND CAPE PRESENT. BEST CHANCE WOULD BE OVER THE
SOUTHERN AND EASTERN PORTIONS OF THE CWA LATE IN THE DAY WHERE
BEST THETA-E ADVECTION OCCURS...WHILE ONE CANT RULE OUT SURFACE
BASED CONVECTIVE INITIATION ALONG A DENVER CONVERGENCE ZONE.
BY FRIDAY NIGHT...STRONG MID LEVEL COLD ADVECTION OCCURS WITH
UPPER TROUGH ADVANCEMENT AND COLD POOL PASSING OVERHEAD.
HOWEVER...WE WILL LIKELY SEE MID LEVEL DRYING WITH GOOD POTENTIAL
OF DRY SLOT PASSING OVER MOST OF THE CWA. AS A RESULT...LOOKS LIKE
BEST CHANCE OF SHOWERS/STORMS WOULD BE EARLY IN THE EVENING WITH
DRYING THEREAFTER. IN THE MOUNTAINS...TEMPERATURES WILL BE COLD
ENOUGH FOR MOSTLY SNOW AND THERE IS A THREAT OF MORE SIGNIFICANT
SNOWFALL DEVELOPING ON THE BACK EDGE DEFORMATION ZONE OF UPPER
TROUGH. AT THIS TIME...BEST LIFT AND TROWAL WOULD PASS OFF TO OUR
NORTH AND WEST AND WE WOULD HAVE TO WAIT UNTIL LATE FRIDAY
NIGHT/SATURDAY MORNING TO GET A STEADY AND HEAVIER SNOW INTO THE
MOUNTAINS AS NORTHWEST FLOW DEVELOPS. ZONE 31 WOULD HAVE BEST SHOT
OF RECEIVING HEAVIER SNOWFALL BUT EVEN THERE BEGINNING OF SNOW
WOULD BE LATE 4TH PERIOD SO NO WATCHES YET. ZONE 33 AND 34 COULD
SEE TOO MUCH DRY SLOT INTERACTION LIMITING ACCUMULATIONS...BUT
THAT ALL DEPENDS ON EXACT STORM PATH. SPEAKING OF WHICH...IT WAS
INTERESTING TO SEE ALMOST ALL 00Z MODELS INCLUDING THE
ECWMF...CANADIAN...AND GFS ENSEMBLES BECOME MORE ELONGATED WITH
THE UPPER TROUGH AS IT PASSES OVER EASTERN COLORADO.
IF THE TROUGH DOES BECOME ELONGATED...THE FORECAST FOR SATURDAY ON
THE PLAINS BECOMES UNCERTAIN AS A MORE NORTHERLY FLOW COULD
RESULT IN LESS DOWNSLOPE AND A CHANCE OF SHOWERS. MEANWHILE...
THREAT OF STRONGEST WINDS WITH GUSTS TO 40 MPH PLUS WOULD SHIFT
FROM THE FAVORED DOWNSLOPE AREAS IN/NEAR THE FOOTHILLS TO THE
EASTERN PLAINS. AT THIS TIME...WE WILL KEEP THE GUSTY WINDS IN THE
FORECAST BUT ALSO INTRODUCE JUST A SLIGHT CHANCE OF SHOWERS IN
CASE THE 00Z MODELS ARE CORRECT. BY SATURDAY NIGHT...MOUNTAIN SNOW
SHOWERS WILL GRADUALLY DECREASE WITH CLEARING SKIES AND
DIMINISHING WINDS ELSEWHERE.
SUNDAY THROUGH THURSDAY LOOKS MAINLY DRY AND WARMER. THERE ARE
STILL A FEW MODELS RUNS POINTING TO A LOW PRECIP THREAT IN THE
MOUNTAINS TUESDAY AND SLIGHT COOLING/GUSTY WINDS. OTHERWISE DRY
WEATHER EXPECTED WITH TEMPERATURES A FEW DEGREES ABOVE NORMAL.
AVIATION...DRAINAGE FLOW EARLY THIS MORNING IS EXPECTED TO SHIFT
TO THE NW AHEAD OF A SURFACE FRONT. THE FRONT SHOULD PASS ACROSS
THE AREA BETWEEN 15Z AND 18Z...WITH SPEEDS 10-15 KTS. AFTER 18Z
WINDS TO BECOME EASTERLY WITH SPEEDS AROUND 10 KTS TRANSITIONING
TO DRAINAGE AGAIN TONIGHT. VFR CONDITIONS EXPECTED THROUGH TONIGHT
AND INTO TOMORROW MORNING. HIGH LEVEL MOISTURE TO DECREASE EARLY
THIS MORNING BEFORE INCREASING AGAIN LATE MORNING. A CHANCE FOR
RAIN SHOWERS WILL OCCUR FRIDAY AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BARJENBRUCH
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1015 AM EDT THU OCT 11 2012
.UPDATE (REST OF TODAY AND TONIGHT)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER UNAMPLIFIED UPPER
LEVEL PATTERN OVER MUCH OF THE CONUS THIS MORNING. MAIN NORTHERN
STREAM FLOW ARRIVES OVER TOP OF A REX BLOCK PATTERN OVER THE PACIFIC
COAST AND THEN RIDES ALONG THE US/CANADIAN BORDER ALONG THE SOUTHERN
PERIPHERY OF AN ELONGATED TROUGH IN PLACE OVER CENTRAL/EASTERN
CANADA. CLOSER TO HOME...UPPER LEVEL RIDGING OVER THE GULF OF MEXICO
IS BEGINNING TO AMPLIFY TO THE NORTH AND NORTHEAST IN RESPONSE TO
HEIGHT FALLS SPREADING OVER THE SW STATES AHEAD OF A POTENT UPPER
LOW ON THE SOUTHERN END OF THE REX BLOCK. THIS RIDGING WILL CONTINUE
TO EXPAND OVER OUR REGION AND HELP EXTEND THE STRETCH OF DRY AND
PLEASANT WEATHER INTO THE WEEKEND. 12Z KTBW SOUNDING SHOWS A DRY
PROFILE THROUGH ALMOST ALL OF THE TROPOSPHERE WITH A SUBSIDENCE
INVERSION AT 900MB AND A PW UNDER 1".
AT THE SURFACE...FORECAST AREA RESIDES WITHIN A LOW LEVEL EASTERLY
FLOW AROUND THE SOUTHERN PERIPHERY OF 1027MB HIGH PRESSURE CENTERED
OVER THE EASTERN TN VALLEY. DUE TO NEARLY 100% OF THE POSSIBLE
INSOLATION...TEMPERATURES ARE QUICKLY REBOUNDING THROUGH THE 70S...
ON THEIR WAY TO AFTERNOON HIGHS IN THE MIDDLE TO UPPER 80S. MAY SEE
A FEW-SCT SHALLOW CU FIELD THIS AFTERNOON...HOWEVER CROSS-SECTION
PLOTS SHOW THAT LOW LEVEL MOISTURE IS VERY SHALLOW AND WILL KEEP
SKIES MOSTLY SUNNY IN THE GRIDS.
ANY FEW-SCT CU QUICKLY DISSIPATE TOWARDS SUNSET PROVIDING MOSTLY
CLEAR/CLEAR SKIES INTO THE OVERNIGHT. THE GRADIENT WILL TIGHTEN
LATER TODAY INTO TONIGHT WHICH SHOULD HELP PREVENT A SIGNIFICANT
AMOUNT OF RADIATIONAL COOLING/RADIATION FOG LATE TONIGHT...HOWEVER
STILL EXPECTING NORMALLY COLDER AND INLAND LOCATIONS TO BOTTOM OUT
IN THE 60S BY SUNRISE.
&&
.PREVIOUS DISCUSSION (FRIDAY - SATURDAY)...
A REINFORCING SURGE OF DRY AIR ACCOMPANYING A WEAK COOL FRONT NOW
OVER THE NORTHERN PENINSULA EARLY THIS MORNING WILL MOVE INTO WEST
CENTRAL AND SOUTHWEST FLORIDA DURING TODAY AS SURFACE HIGH PRESSURE
BUILDS IN OVER THE MID ATLANTIC. A DRY AND STABLE AIR MASS WILL
SUPPORT PLEASANT DRY WEATHER WITH LOWER HUMIDITY VALUES UNDER MOSTLY
SUNNY SKIES WITH TEMPERATURES CLIMBING INTO THE MID AND UPPER 80S.
TONIGHT THROUGH SATURDAY HIGH PRESSURE ALONG THE MID ATLANTIC WILL
BE REINFORCED BY ANOTHER STRONGER HIGH MOVING SOUTHEAST FROM THE
GREAT LAKES REGION AS UPPER RIDGING BUILDS IN OVER THE GULF IN
RESPONSE TO THE CLOSED LOW OVER CALIFORNIA OPENING UP AND MOVING
EAST INTO THE FOUR-CORNERS REGION. A DRY SUBSIDENT AIR MASS UNDER
THE RIDGING WILL CONTINUE TO SUPPORT PLEASANT DRY WEATHER ACROSS
THE ENTIRE FORECAST AREA WITH CLEAR NIGHTS AND MOSTLY SUNNY DAYS.
DAYTIME TEMPERATURES WILL RUN SOME 2 TO 4 DEGREES ABOVE NORMAL
WITH HIGHS CLIMBING INTO THE MID AND UPPER 80S...WHILE THE DRY AIR
MASS AND CLEAR SKIES WILL ALLOW NIGHTTIME LOWS TO RUN BELOW NORMAL
WITH LOWS IN THE UPPER 50S TO LOWER 60S OVER THE NATURE COAST...AND
MID TO UPPER 60S CENTRAL AND SOUTH...EXCEPT LOWER 70S ALONG THE
IMMEDIATE COAST.
&&
.AVIATION...
VFR NEXT 24 HOURS. SOME PATCHY GROUND FOG POSSIBLE AGAIN FRIDAY
MORNING BUT PROBABILITIES TOO LOW TO MENTION IN TAFS.
&&
.MARINE...
STRONGER SURFACE HIGH PRESSURE BUILDING IN OVER THE MID ATLANTIC
WILL SUPPORT AN UPTICK IN THE NORTHEAST WIND FLOW OVER THE GULF
WATERS TODAY...AND WILL THEN HELP TO TIGHTEN THE PRESSURE GRADIENT
ACROSS THE REGION TONIGHT THROUGH FRIDAY WHICH WILL RESULT IN A
BREEZY NORTHEAST TO EASTERLY WIND FLOW DEVELOPING WITH SPEEDS
LIKELY TO INCREASE TOWARD EXERCISE CAUTION LEVELS DURING FRIDAY
AND FRIDAY NIGHT...ESPECIALLY OVER THE OFFSHORE WATERS. DURING
FRIDAY NIGHT AND SATURDAY THE HIGH ALONG THE MID ATLANTIC WILL BE
REINFORCED BY YET AN EVEN STRONGER RIDGE BUILDING SOUTHEAST FROM
THE GREAT LAKES REGION WHICH WILL KEEP WIND AND SEAS ELEVATED
THROUGH THE UPCOMING WEEKEND...WITH EASTERLY SURGES LIKELY TO
PRODUCE ADDITIONAL PERIODS OF EXERCISE CAUTION OR EVEN LOW END
SMALL CRAFT CONDITIONS. LIGHTER WINDS WILL RETURN TO THE WATERS
EARLY NEXT WEEK AS THE HIGH WEAKENS AND SHIFTS EAST INTO THE
ATLANTIC AHEAD OF THE NEXT FRONT MOVING INTO THE SOUTHEASTERN STATES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 88 67 87 68 / 0 0 0 0
FMY 87 68 87 68 / 0 0 0 0
GIF 88 67 87 68 / 0 0 0 0
SRQ 87 68 88 67 / 0 0 0 0
BKV 88 59 86 60 / 0 0 0 0
SPG 86 72 86 72 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...JILLSON
PREVIOUS DISCUSSION...MCMICHAEL
AREA FORECAST DISCUSSION
NWS CARIBOU ME
949 AM EDT THU OCT 11 2012
.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE EAST OF THE AREA TODAY AS HIGH
PRESSURE BUILDS SOUTH OF THE REGION. WEAK FAST MOVING LOW PRESSURE WILL
MOVE ACROSS FAR NORTHERN MAINE LATE TONIGHT. COLD HIGH PRESSURE
WILL FOLLOW FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: ADJUSTED THE POPS TO REFLECT THE LATEST RADAR TRENDS
W/SCATTERED SHOWERS MOVING ACROSS THE NORTHERN PORTION OF THE
REGION THIS MORNING. INCREASED THE PERCENTAGES AND AREAL COVERAGE
FOR LATE MORNING INTO THE AFTERNOON. INCLUDED A BRIEF PERIOD OF SNOW
FOR THIS UPDATE W/VERY COLD AIR ALOFT. LITTLE OR NO ACCUMULATION IS
EXPECTED.
UPPER TROF W/STRONG VORTICITY ADVECTION WILL AID IN LIFT.
LATEST RUC SOUNDINGS SHOW LAPSE RATES TO STEEPEN LATER THIS MORNING
INTO THE AFTERNOON W/INVERTED V IN THE LLVLS. THIS COMBINED W/CAA
WILL ALLOW FOR SOME STRONGER WIND GUSTS INTO THE AFTERNOON.
THEREFORE, INCREASED THE GUST POTENTIAL UP 5-10 KTS EVERYWHERE.
COULD VERY WELL SEE GUSTS HIT 40+MPH OVER OPEN AND HIGHER TERRAIN
AREAS. TWEAKED DEWPOINTS USING THE LATEST LAMP GUIDANCE SHOWING
READINGS TO DROP THROUGH THE DAY.
SEE MARINE SECTION BELOW.
PREVIOUS DISCUSSION...
STRONG CAA EXPECTED TO OVERSPREAD THE FA TODAY ON BRISK W TO NW
WNDS AS RIDGE OF CANADIAN HIGH PRES BEGINS TO BUILD INTO THE
REGION. MAX TEMPS LIKELY TO BE REACHED BY LATE AM/ERLY AFTN
BEFORE STEADYING OUT OR EVN FALLING A BIT THIS AFTN. CLOUDS AND
WNDS SHOULD DECREASE QUICKLY BY MID TO LATE AFTN AS THE RIDGE AXIS
IS EXPECTED TO QUICKLY CREST THE AREA BY THIS EVE AHEAD OF A FAST
MVG BUT WEAK SFC LOW PRES SYSTEM WHICH MODEL CONSENSUS HAS
CROSSING FAR NRN MAINE BY 12Z FRI. WEAK WAA AHEAD OF THIS SYSTEM
WILL ALLOW PRECIP TO OVERSPREAD FAR N AND NW AREAS BEFORE MDNGT
AND REACH NERN AREAS 06-08Z. BL TEMPS/CRITICAL THCKNS VALS SUGGEST
BEST CHC FOR ANY SNOW REMAINS ACROSS THE FAR N AND NW WHERE AN
INCH OR SO IS PSBL. WILL CONT CAT TO LIKELY POPS FAR NRN AREAS W/CHC
POPS CENTRAL AND S. OVERALL EXPECT THIS UPCOMING EVENT TO PRODUCE
ONLY LGT QPF AMOUNTS W/ PRECIP MAXES BLO .25 INCHES EXPECTED...
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
CLIPPER-TYPE LOW PRESSURE WILL BE EXITING FROM MAINE INTO NEW
BRUNSWICK LATE FRIDAY MORNING, WITH HIGH PRESSURE QUICKLY BEGINNING
TO BUILD OVER THE NORTHEAST CONUS THEREAFTER. SHOWERS WILL LINGER
THROUGH THE MORNING HOURS, BUT WILL QUICKLY END BY EARLY AFTERNOON.
EARLY MORNING TEMPERATURES WILL BE COLD ENOUGH FOR SNOW OR A
RAIN/SNOW MIX, BUT ANTICIPATE LITTLE TO NO ACCUMULATION, ESPECIALLY
ONCE THE SUN COMES UP. CLOUDS WILL LINGER ACROSS THE NORTHWESTERN
PORTIONS OF THE STATE, BUT MOST AREAS SHOULD SEE SUNSHINE BEGIN TO
BREAK THROUGH IN THE AFTERNOON, ESPECIALLY DOWNEAST. HOWEVER, EVEN
WITH SUN, IT WILL FEEL VERY CHILLY FRIDAY AS BRISK NORTHWEST WINDS
DEVELOP IN THE TIGHT PRESSURE GRADIENT BETWEEN THE RETREATING LOW
AND THE ADVANCING HIGH. WINDS OF 15 TO 25 MPH WITH GUSTS TO 30 MPH
CAN BE EXPECTED. TEMPERATURES WILL RANGE FROM AROUND 40 IN THE NORTH
WOODS TO AROUND 50 DOWNEAST.
HIGH PRESSURE WILL SLOWLY BUILD EASTWARD FRIDAY NIGHT INTO SATURDAY,
EVENTUALLY MOVING OFF THE MID ATLANTIC COAST AND OUT TO SEA. AS
SUCH, EXPECT CLEARING SKIES FOR FRIDAY NIGHT INTO SATURDAY MORNING.
OVERNIGHT TEMPERATURES WILL BE QUITE COLD WITH EVERYONE GETTING DOWN
INTO THE 20S. WINDS WILL SUBSIDE A BIT FROM FRIDAY AFTERNOON, BUT
SHOULD REMAIN HIGH ENOUGH TO PRECLUDE ANY FOG DEVELOPMENT OUTSIDE OF
THE DEEPER RIVER VALLEYS. SATURDAY WILL START OUT MOSTLY SUNNY, BUT
EXPECT STRATOCUMULUS TO ARISE BY LATE MORNING AS MIXING OCCURS.
WINDS WILL ONCE AGAIN BE ON THE GUSTY SIDE, THOUGH NOT AS STRONG AS
ON FRIDAY. TEMPERATURES ON SATURDAY WILL BE SIMILAR TO THOSE ON
FRIDAY, TOPPING OUT IN THE 40S IN MOST SPOTS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE UNSETTLED PATTERN CONTINUES THROUGH THE LONG TERM. WE START OFF
WITH A FRONTAL SYSTEM SET TO MOVE ACROSS THE GREAT LAKES SATURDAY
NIGHT INTO SUNDAY, WITH THE LEADING WARM FRONT MOVING ACROSS MAINE
DURING THAT TIME FRAME. THE LOW WILL THEN TRAVERSE EASTWARD
THROUGH SOUTHERN QUEBEC, DRAGGING ITS COLD FRONT THROUGH THE
FORECAST AREA MONDAY AFTERNOON AND NIGHT. AS SUCH, SUNDAY AND
MONDAY WILL BE WET, WITH A MIX OF RAIN AND SNOW POSSIBLE OVER THE
NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING. WRAP AROUND
SHOWERS CONTINUE INTO EARLY TUESDAY, THEN CONDITIONS WILL DRY OUT
AS HIGH PRESSURE BUILDS OVER THE AREA. THIS FEATURE WILL KEEP FAIR
WEATHER IN THE STATE TUESDAY AFTERNOON THROUGH WEDNESDAY. MONDAY
WILL BE THE WARMEST DAY OF THE PERIOD, THOUGH IT DEPENDS ON HOW
LONG THE AREA STAYS IN THE WARM SECTOR BEFORE THE COLD FRONT
PUSHES THROUGH. OTHERWISE, TEMPERATURES WILL BE NEAR SEASONAL
NORMAL THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
NEAR TERM: MAINLY VFR CONDS WILL PREVAIL TODAY INTO TNGT THO CAN
NOT RULE OUT SOME PATCHY MVFR ACROSS OUR NRN TAF SITES THIS AM IN
SOME POST-FRONTAL SC. MFR TO PSBL IFR CONDS ARE PSBL ACROSS THE
NRN TAF SITES LATE TNGT/ERLY FRI AS A FAST MVG LOW PRES SYSTEM
CROSSES FAR NRN AREAS W/ SOME LGT RAIN OR WET SNOW.
SHORT TERM: MVFR/OCCASIONAL IFR EXPECTED THROUGH 15Z FRIDAY DUE TO
LOW CEILINGS AND PRECIPITATION. RAIN MAY MIX WITH SNOW EARLY AT THE
NORTHERN TERMINALS. CONDITIONS IMPROVE FRIDAY AFTERNOON WITH VFR
CONDITIONS EXPECTED THROUGH SATURDAY. PRECIPITATION RETURNS SATURDAY
NIGHT AND CONTINUES THROUGH MONDAY. EXPECT MAINLY MVFR CONDITIONS
DURING THIS PERIOD. THE EXCEPTIONS WILL BE EARLY SUNDAY MORNING WHEN
SNOW MAY DROP THINGS TO IFR AT THE NORTHERN SITES. OCCASIONAL IFR
CEILINGS ARE ALSO POSSIBLE SUNDAY AND SUNDAY NIGHT, WHEN THE
STEADIEST RAIN IS EXPECTED.
&&
.MARINE...
NEAR TERM:
UPDATE...UPGRADED THE HEADLINE TO GLW AS WINDS ARE CREEPING UP
CLOSE TO 34 KTS. 44027 ALREADY AT 33 KTS AT 9 AM. THINKING IS THAT
GUSTS WILL HIT 35 KTS THROUGH THE AFTERNOON INCLUDING THE INTRA-
COASTAL WATERS. INVERTED V TYPE SOUNDINGS SHOWING STRONG
INSTABILITY AND CAA WILL ALLOW FOR STRONGER WINDS ALOFT TO MIX
DOWN TO THE BLYR. SCA CONDITIONS EXPECTED TONIGHT W/A BRIEF
REPRIEVE IN THE WINDS BEFORE THEY COME BACK UP ON FRIDAY.
SHORT TERM: THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED THROUGH BY
FRIDAY NIGHT SINCE WINDS LOOK TO INCREASE AHEAD OF A CLIPPER-TYPE
LOW PRESSURE SYSTEM. WINDS OF 20 TO 30 KT AND WAVES 5 TO 7 FT CAN
BE EXPECTED TO LAST INTO FRIDAY EVENING. CONDITIONS WILL BEGIN TO
IMPROVE BY AROUND MIDNIGHT AS HIGH PRESSURE BEGINS TO BUILD OVER
THE REGION. HOWEVER, GUSTY WINDS AROUND 20 KT WILL STILL BE
POSSIBLE THROUGH SATURDAY MORNING.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING UNTIL 8 PM EDT THIS EVENING FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT/KHW
SHORT TERM...HASTINGS
LONG TERM...HASTINGS
AVIATION...HEWITT/KHW
MARINE...HEWITT/KHW/HASTINGS
AREA FORECAST DISCUSSION
NWS GRAY ME
944 AM EDT THU OCT 11 2012
.SYNOPSIS...
GUSTY WEST WINDS ARE EXPECTED BEHIND THE FRONT TODAY WITH
MOSTLY SUNNY SKIES OUTSIDE THE MOUNTAINS. ANOTHER COLD FRONT WILL
CROSS THE REGION FRIDAY MORNING...BRINGING VERY COLD
TEMPERATURES OVERNIGHT INTO SATURDAY. A HIGH BUILDS IN FOR THE
START OF THE WEEKEND BEFORE ANOTHER LOW MOVES UP THE SAINT
LAWRENCE VALLEY ON SUNDAY NIGHT WITH WIDESPREAD RAIN SHOWERS AND
MODERATE TEMPERATURES EXPECTED THROUGH THE START OF NEXT WEEK.
&&
.NEAR TERM /TODAY/...
945 AM UPDATE...HAVE UPDATED TO ADJUST POPS AND SKY COVER TO
REFLECT CURRENT THINKING. SHOULD BE A SUNNY DAY ON THE DOWNSLOPING
SIDE OF THE MOUNTAINS. BUT IN UPSLOPE AREAS SOME RAIN/SNOW SHOWERS
WILL CONTINUE THROUGH THE REMAINDER OF THE MORNING BEFORE
GRADUALLY DISSIPATING. NO OTHER SIGNIFICANT CHANGES WERE MADE.
UPDATE... HAVE UPDATED GRIDS BASED ON LATEST RADAR AND INFRARED
SATELLITE IMAGERY. UPSLOPE SNOW SHOWERS CONTINUE IN THE WESTERN
MOUNTAINS OF MAINE AND NORTHERNMOST NEW HAMPSHIRE AT THIS HOUR.
LATEST HRRR MODEL RUN DEPICTING A FEW MORE OF THESE FAST MOVING
SPRINKLES/SHOWERS CONTINUING UNTIL THIS AFTERNOON.
MINOR ADJUSTMENTS MADE TO WIND/CLOUD GRIDS. OTHERWISE FORECAST ON
TRACK.
PREVIOUS DISCUSSION...
GUSTY WEST WINDS WILL DOMINATE OUR WEATHER CONDITIONS TODAY AS THE
PRESSURE GRADIENT REMAINS IN PLACE TODAY WITH COLD AIR ADVECTION.
DOWNSLOPING WILL OCCUR OUTSIDE THE MOUNTAINS...ALLOWING FOR SUNSHINE
AND TEMPS TO CLIMB THRU THE UPPER 50S TO NEAR 60. MUCH COOLER IN
THE MOUNTAINS WITH CLOUD COVER AND ISOLATED SHOWERS/SPRINKLES. LOOK
FOR HIGHS ONLY IN THE UPPER 40S ACROSS THE HIGHER TERRAIN. USED A
BLEND OF MAV/MET MOS FOR MAX TEMPERATURES TODAY.
&&
.SHORT TERM /TONIGHT AND FRIDAY/...
MID AND HIGH LEVEL MOISTURE WILL ALREADY BE ADVECTING QUICKLY INTO
THE REGION BY THIS EVENING ACROSS MUCH OF MAINE AND NEW HAMPSHIRE.
YET ANOTHER FRONT WILL BRING THE THREAT OF SHOWERS AND EVEN A FEW
SNOW SHOWERS ABOVE 2500 FEET. ANY LIGHT PRECIPITATION WILL MOSTLY
BE CONFINED TO NORTHERN AREAS.
GUSTY WINDS AND ANOTHER SHOT OF COLD AIR WILL ENTER THE REGION ON
FRIDAY. LOOK FOR HIGH TEMPERATURES TO OCCUR AROUND NOONTIME...BEFORE
SETTLING BACK. A STRONG RIDGE OF HIGH PRESSURE WILL CONTINUE TO
BUILD TOWARDS NEW ENGLAND THRU THE DAY. THIS SETS THE STAGE FOR
THE COLDEST AIR OF THE SEASON AND WIDESPREAD FREEZES IN THE
EXTENDED PORTION OF THE FORECAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
WE BEGIN THE PERIOD WITH AN IMPULSE EXITING THE REGION...AND
IN ITS WAKE INTRODUCING AN EARLY TASTE OF LATE FALL CHILL TO THE
REGION. SURFACE HIGH PRESSURE WITH DRY AIR AND BELOW NORMAL
TEMPERATURES WILL BUILD ACROSS THE AREA FOR FRIDAY NIGHT AND
SATURDAY. A SHORT WAVE ARRIVES FROM THE UPPER MIDWEST FOR SATURDAY
NIGHT AND SUNDAY. AN ASSOCIATED SURFACE LOW TRACKS FROM THE UPPER
GREAT LAKES ON SUNDAY TO THE SAINT LAWRENCE VALLEY ON MONDAY
PULLING ITS ASSOCIATED WARM AND COLD FRONTS ACROSS THE AREA. THE
WARM FRONT MAY PRODUCE SOME LIGHT SNOW ACROSS THE HIGH TERRAIN
EARLY SUNDAY...AS THE FORECAST PROFILES THERE ARE INITIALLY COLD
ENOUGH FOR SNOW. ABOVE NORMAL TEMPERATURES THEN FOLLOW THE WARM
FRONT IN SOUTHERLY FLOW FOR BOTH SUNDAY AND MONDAY...WITH COLD
FRONT TO CROSS THE AREA LATE MONDAY FOLLOWED BY A RETURN TO MORE
AVERAGE TEMPERATURES FOR THE REMAINDER OF THE PERIOD. HIGH
PRESSURE WILL BUILD ACROSS THE REGION FOR THE MID WEEK PERIOD.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SHORT TERM...
WILL SEE VFR CONDITIONS TODAY WITH WESTERLY WINDS GUSTING FROM 20
TO 25 KT. MAY SEE CONDITIONS LOWER AGAIN TONIGHT AS THE NEXT WAVE
APPROACHES.
LONG TERM...
SUN - MON...AREAS OF MVFR IN SHOWERS.
&&
.MARINE...
SHORT TERM...
THE SMALL CRAFT ADVISORY CONTINUES THROUGH THURSDAY AFTERNOON AS
WESTERLY WINDS BEHIND A COLD FRONT ARE EXPECTED TO GUST FROM 25 TO
30 KT WITH A FEW GUSTS TO 35 KT POSSIBLE MAINLY DURING THE DAY
THURSDAY. HAVE ALSO INCLUDED THE BAYS IN THE SMALL CRAFT ADVISORY
AS WINDS WILL BE GUSTING IN THE BAYS AS WELL.
SOUTHWEST FLOW PICKS UP TONIGHT...WITH SMALL CRAFT ADVISORY LEVEL
CONDITIONS POSSIBLE OVER THE OUTER WATERS. WILL NOT ISSUE A NEW
ADVISORY AT THIS TIME AND WILL ALLOW THE DAY SHIFT TO TREAT THIS
SEPARATE WIND/WAVE EVENT LATER TODAY. ADVISORY LEVEL WINDS LIKELY
ON FRIDAY AS WELL IN STRONG COLD AIR ADVECTION AND INCREASING
GRADIENT.
LONG TERM...
FRI NIGHT...A SMALL CRAFT FOR WINDS AND SEAS IS POSSIBLE.
SUN - MON...A SMALL CRAFT FOR WINDS AND SEAS IS POSSIBLE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ150>154.
&&
$$
UPDATE...KIMBLE
AREA FORECAST DISCUSSION
NWS GRAY ME
707 AM EDT THU OCT 11 2012
.SYNOPSIS...
GUSTY WEST WINDS ARE EXPECTED BEHIND THE FRONT TODAY WITH
INCREASING SUNSHINE. ANOTHER COLD FRONT WILL CROSS THE REGION FRIDAY
MORNING...BRINGING VERY COLD TEMPERATURES OVERNIGHT INTO
SATURDAY. A HIGH BUILDS IN FOR THE START OF THE WEEKEND BEFORE
ANOTHER LOW MOVES UP THE SAINT LAWRENCE VALLEY ON SUNDAY NIGHT
WITH WIDESPREAD RAIN SHOWERS AND MODERATE TEMPERATURES EXPECTED
THROUGH THE START OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAVE UPDATED GRIDS BASED ON LATEST RADAR AND IR STLT IMAGERY.
UPSLOPE -SHSN CONTS IN THE WRN MTNS OF ME AND NRNMST NH AT THIS
HR. LATEST HRRR MODEL RUN DEPICTING A FEW MORE OF THESE FAST
MOVING SPRINKLES/SHOWERS CONTG UNTIL THIS AFTN.
MINOR ADJUSTMENTS MADE TO WIND/CLOUD GRIDS. OTRW FCST ON TRACK.
PREV DISC...
GUSTY WESTERLY WINDS WILL DOMINATE OUR WEATHER CONDS TODAY
AS THE PRES GRADIENT REMAINS IN PLACE TODAY WITH CAA. DOWNSLOPING
WILL OCCUR OUTSIDE THE MTNS...ALLOWING FOR SUNSHINE AND TEMPS TO
CLIMB THRU THE UPPER 50S TO NEAR 60. MUCH COOLER IN THE MTNS WITH
CLOUD COVER AND ISOLD -SHRA/SPRINKLES. LOOK FOR HIGHS ONLY IN THE
UPPER 40S ACROSS THE HIGHER TRRN. USED A BLEND OF MAV/MET MOS FOR
MAX TEMPS TODAY.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
MID AND HIGH LEVEL MOISTR WILL ALREADY BE ADVECTING QUICKLY INTO
THE REGION BY THIS EVENING ACROSS MUCH OF MAINE AND NEW HAMPSHIRE.
YET ANOTHER FRONT WILL BRING THE THREAT OF -SHRA AND EVEN A FEW
-SHSN ABOVE 2500 FEET. ANY LIGHT PCPN WILL MOSTLY BE CONFINED TO
NRN AREAS.
GUSTY WINDS AND ANOTHER SHOT OF COLD AIR WILL ENTER THE REGION ON
FRIDAY. LOOK FOR HIGH TEMPS TO OCCUR AROUND NOONTIME...BEFORE
SETTLING BACK. A STRONG RIDGE OF HIGH PRES WILL CONT TO BUILD
TOWARDS NEW ENGLAND THRU THE DAY. THIS SETS THE STAGE FOR THE
COLDEST AIR OF THE SEASON AND WIDESPREAD FREEZES IN THE EXTENDED
PTN OF THE FCST.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
WE BEGIN THE PERIOD WITH AN IMPULSE EXITING THE REGION...AND
IN ITS WAKE INTRODUCING AN EARLY TASTE OF LATE FALL CHILL TO THE
REGION. SURFACE HIGH PRESSURE WITH DRY AIR AND BELOW NORMAL
TEMPERATURES WILL BUILD ACROSS THE AREA FOR FRIDAY NIGHT AND
SATURDAY. A SHORT WAVE ARRIVES FROM THE UPPER MIDWEST FOR SATURDAY
NIGHT AND SUNDAY. AN ASSOCIATED SURFACE LOW TRACKS FROM THE UPPER
GREAT LAKES ON SUNDAY TO THE SAINT LAWRENCE VALLEY ON MONDAY
PULLING ITS ASSOCIATED WARM AND COLD FRONTS ACROSS THE AREA. THE
WARM FRONT MAY PRODUCE SOME LIGHT SNOW ACROSS THE HIGH TERRAIN
EARLY SUNDAY...AS THE FORECAST PROFILES THERE ARE INITIALLY COLD
ENOUGH FOR SNOW. ABOVE NORMAL TEMPERATURES THEN FOLLOW THE WARM
FRONT IN SOUTHERLY FLOW FOR BOTH SUNDAY AND MONDAY...WITH COLD
FRONT TO CROSS THE AREA LATE MONDAY FOLLOWED BY A RETURN TO MORE
AVERAGE TEMPERATURES FOR THE REMAINDER OF THE PERIOD. HIGH
PRESSURE WILL BUILD ACROSS THE REGION FOR THE MID WEEK PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
SHORT TERM...
WILL SEE VFR CONDITIONS TODAY WITH WESTERLY WINDS GUSTING FROM 20
TO 25 KT. MAY SEE CONDITIONS LOWER AGAIN TONIGHT AS THE NEXT WAVE
APPROACHES.
LONG TERM...
SUN - MON...AREAS OF MVFR IN SHOWERS.
&&
.MARINE...
SHORT TERM...
THE SMALL CRAFT ADVISORY CONTS THROUGH THURSDAY AFTERNOON AS
WESTERLY WINDS BEHIND A COLD FRONT ARE EXPECTED TO GUST FROM 25 TO
30 KT WITH A FEW GUSTS TO 35 KT POSSIBLE MAINLY DURING THE DAY
THURSDAY. HAVE ALSO INCLUDED THE BAYS IN THE SMALL CRAFT ADVISORY
AS WINDS WILL BE GUSTING IN THE BAYS AS WELL.
SW FLOW PICKS UP TONIGHT...WITH SCA CONDS PSBL OVER THE OUTER
WATERS. WILL NOT ISSUE SCA AT THIS TIME AND WILL ALLOW THE DAY
SHIFT TO TREAT THIS SEPARATE WIND/WAVE EVENT LATER TODAY. SCA
WINDS LIKELY ON FRI AS WELL IN STG CAA AND INCREASING GRADIENT.
LONG TERM...
FRI NIGHT...A SMALL CRAFT FOR WINDS AND SEAS IS POSSIBLE.
SUN - MON...A SMALL CRAFT FOR WINDS AND SEAS IS POSSIBLE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
ANZ150>154.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
618 AM EDT THU OCT 11 2012
.SYNOPSIS...
CHILLY EARLY MORNING TEMPERATURES WILL GIVE WAY TO PLENTY OF
SUNSHINE TODAY AS HIGH PRESSURE BUILDS INTO OUR AREA. A WEAK COLD
FRONT WILL CROSS THE REGION TONIGHT INTO FRIDAY MORNING. HIGH
PRESSURE WILL THEN BUILD IN FOR THE EARLY PART OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
600 AM UPDATE...
TWEAKED TEMPERATURES FOR EARLY MORNING AND CLEARED OUT CLOUDS
THROUGH MUCH OF NORTH. WAITED FOR CLOUDS TO DEPART NORTH SECTIONS
IN HOPES OF TEMPERATURES FALLING INTO LOWER 30S FOR DISCONTINUING
FREEZE PROGRAM. DUJ AND IDI BOTH DROPPED TO 34. WILL CONTINUE TO
MONITOR.
PREVIOUS DISCUSSION FOLLOWS... HIGH PRESSURE WILL DOMINATE TODAY
WITH DRY WEATHER AND MODERATING TEMPERATURES. HIGH TEMPERATURES
WILL RECOVER TO NEAR 60 BY THIS AFTERNOON. A WEAK COLD FRONT WILL
PUSH ACROSS THE DISTRICT LATE TONIGHT INTO FRIDAY
MORNING...BRINGING JUST A CHANCE OF SHOWERS DUE TO A LACK OF
MOISTURE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE COLD FRONT WILL PUSH EAST OF THE DISTRICT BY MID DAY FRIDAY
ENDING THE RISK OF SHOWERS BY AFTERNOON. ANOTHER COLD NIGHT IS
ANTICIPATED FRIDAY NIGHT BEFORE WARM ADVECTION RESUMES IN ADVANCE OF
A STRONGER COLD FRONT ACROSS THE MIDWEST. THE SHORT WAVE RIDGE IN THE
AMPLIFIED FLOW SUPPORTS A WARMER...AND STILL DRY SATURDAY...ALTHOUGH
SLIGHT CHC POPS WERE INCLUDED OVER NRN COUNTIES AS MDLS...WITH GFS
PROJECTING A MORE SRN EXTENT...SPAWN PCPN ALNG THE ADVNG LOWS WARM
FRONT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
LOW PRES IS STILL PROJECTED ACRS THE GREAT LAKES ON SUNDAY...AS IS
THE SYSTEMS CDFNT ACRS THE UPR OH REGION. AS IN PREVIOUS
SYSTEMS...THE BTR MID LVL SPPRT AND MSTR IS FORECAST N OF THE
AREA...HENCE POPS WERE CONFINED TO THE CHC CATEGORY...WITH THE
HIGHER NMBRS DRAWN FM PIT NWD.
THEREAFTER...CONFIDENCE IN THE LONG TERM FORECAST DROPS AS MDLS
DIVERGE IN MAGNITUDE AND TIMING OF SHRTWVS WITHIN A STILL-
PROGRESSIVE PTN. FORECAST IS THUS CLOSE TO HPC GUIDANCE IN
DEPICTIONS OF NR NORMAL TEMPS AND SLGT CHC...TO CHC POPS.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
STRATO-CU STILL HANGING ACROSS NORTHERN TERMINALS IN NW 850 FLOW
AND 850 TEMPERATURES NEAR MINUS 4C. 850 FLOW GOES ZONAL EARLY THURSDAY
AND STRATO-CU SHOULD BE ON THE WANE. CURRENTLY MORE STRATO-CU
UPSTREAM BUT HRRR AND GFS SUGGESTING AS FLOW GOES ZONAL TO
SOUTHWEST...CLOUDS NOW OVER WI ERODE AND GENERALLY LIFT NORTHWARD.
WITH GENERAL FLOW GOING SOUTHWEST TODAY... WILL JUST GO WITH
SCT050 CU AND CLEAR IT OUT TOWARD SUNSET THIS EVENING BEFORE
BRINGING IN AC AND CI TOWARD 06Z FRIDAY. WINDS DECREASING ACROSS
CWA WITH DUJ ONLY TERMINAL STILL GUSTING AT THIS TIME. EXPECT
CONTINUED DIMINISHING OVERNIGHT.
.OUTLOOK.../THURSDAY NIGHT THROUGH SUNDAY/...
WEAK FRONT APPROACHES OVERNIGHT THURSDAY INTO FRIDAY WITH MID DECK
AND CI BUT EXPECT VFR CONDITIONS. HIGH PRESSURE THEN BUILDS ACROSS
REGION THROUGH SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR PAZ016-022-023-
031-073-075.
WV...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ004-012-021-
022.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1054 AM EDT THU OCT 11 2012
.SYNOPSIS...
ISSUED AT 345 AM EDT THU OCT 11 2012
WINDY CONDITIONS AND A FEW SHOWERS ARE ANTICIPATED TODAY AS A
CLIPPER SYSTEM MOVES THROUGH. SOME SHOWERS WILL LINGER TONIGHT
BEFORE FAIR WEATHER RETURNS FRIDAY AS HIGH PRESSURE BUILDS IN. A
STRONG LOW PRESSURE SYSTEM WILL MOVE THROUGH OUR REGION THIS WEEKEND
BRINGING POTENTIAL FOR WINDY CONDITIONS HEAVY RAINFALL AND
THUNDERSTORMS.
&&
.UPDATE...
ISSUED AT 1052 AM EDT THU OCT 11 2012
HAVE HOISTED A WIND ADVISORY FOR A GOOD PORTION OF THE FORECAST
AREA AS WINDS RAMP UP AHEAD OF THE COLD FRONT. TIGHT GRADIENT IS
IN PLACE AHEAD OF THE FRONT. SOUTHWEST FLOW OFF THE LAKE WILL PEAK
ACROSS THE GRR FORECAST AREA BETWEEN NOON AND 400 PM. WIND GUSTS
WILL PUSH TOWARDS 45 MPH. IT WILL BE A CLOSE CALL...NOT A SLAM
DUNK IT APPEARS ESPECIALLY GIVEN THE CLOUDS TRYING TO ADVANCE IN
FROM THE NORTH. IF THESE CLOUDS SLOW OR ERODE A BIT ON THE SOUTH
EDGE THE MIXING WILL ENHANCE THE WIND GUSTS. HRRR IS SHOWING A
PRETTY GOOD BET FOR WIND GUSTS PUSHING INTO THE 40-50 MPH.
ESPECIALLY DOWN WIND OF THE LAKE IN SOUTHWEST FLOW FROM LWA/MKG
INLAND TO LAN/AMN. OTHERWISE FORECAST IN GOOD SHAPE WITH SOME
LIGHT SHOWERS TRYING TO ADVANCE SOUTH WITH TIME THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON)
ISSUED AT 345 AM EDT THU OCT 11 2012
A CLIPPER SYSTEM WILL BRING WINDY CONDITIONS TODAY. IN FACT
CONDITIONS MAY FLIRT WITH WIND ADVISORY CRITERIA (GUSTS REACHING 45
MPH) BY LATE MORNING INTO THIS AFTERNOON. DECIDED AGAINST A HEADLINE
THOUGH SINCE GUSTS PRIMARILY IN THE 35 TO 44 MPH ARE THE MOST
PROBABLE OUTCOME WITH MINIMAL IMPACTS. THIS SYSTEM WILL ALSO BRING A
FEW SHOWERS THIS AFTN/TONIGHT. BUMPED POPS UP SLIGHTLY INTO THE LOW
CHC CATEGORY FOR THE SOUTHERN TWO THIRDS OF OUR FCST AREA TONIGHT
BASED ON OVERALL SHORT RANGE GUIDANCE TRENDS.
FAIR WX IS ANTICIPATED FRIDAY THROUGH FRIDAY NIGHT WITH HIGH
PRESSURE IN CONTROL. THE WARM FRONT ASSOCIATED WITH THE STRONG LOW
PRESSURE SYSTEM OFF TO OUR WEST WILL BRING RAIN AND A CHC OF
THUNDERSTORMS SATURDAY. THIS AS ELEVATED INSTABILITY INCREASES AND
H8 LI/S GO SLIGHTLY NEGATIVE ALONG WITH INCREASING 1000-850 MB
MOISTURE TRANSPORT AND PRECIPITABLE WATER VALUES REACHING THE 1.5 TO
1.75 INCH RANGE BY MIDDAY SATURDAY. THE THREAT FOR ANY SVR WX WILL
MOST LIKELY HOLD OFF UNTIL SATURDAY NIGHT INTO SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM EDT THU OCT 11 2012
STRONG FALL STORM MOVES THROUGH SATURDAY NIGHT AND SUNDAY. BUMPED UP
POPS...ESPECIALLY ACROSS THE NORTH WHERE CATEGORICAL IS WARRANTED.
GFS CONTINUES TO SHOW VERY STRONG SHEAR PROFILES AND SOME
INSTABILITY SATURDAY NIGHT...SO THREAT FOR SEVERE WEATHER WILL BE
PRESENT. CONVECTION OVER WISCONSIN ON SATURDAY COULD MAKE IT INTO
LOWER MICHIGAN SATURDAY EVENING IN THE FORM AN ORGANIZED LINE OF
STORMS.
SOME ROTATING STORMS COULD BE EMBEDDED IN THIS LINE ACROSS
THE SOUTHERN FORECAST AREA WHERE 0 TO 1 KM STORM RELATIVE HELICITY
IS PROGGED TO BE OVER 100. OVERALL THREAT APPEARS TO BE STRAIGHT
LINE WINDS AS ENVIRONMENTAL WINDS ARE ABOVE 50 KNOTS WITHIN 3 KFT
AGL. TORNADIC THREAT IS SECONDARY AND MOSTLY CONFINED TO THE SOUTH.
SFC LOW TRACKS ACROSS NORTHERN LOWER MICHIGAN SUNDAY WITH THE COLD
FRONT MOVING THROUGH AND SHOWERS TAPERING OFF SUNDAY NIGHT. SFC
RIDGE WILL HOLD SWAY INTO TUESDAY NIGHT. DROPPED POPS FOR TUESDAY.
NORTHERN STREAM SHORTWAVE APPROACHES BY WEDNESDAY WITH SHOWERS
ARRIVING AND CONTINUING WED NIGHT AS TROUGH AXIS ARRIVES ALONG WITH
SFC CYCLONE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 718 AM EDT THU OCT 11 2012
VFR CONDITIONS EXPECTED TODAY AND INTO TONIGHT. SOME SHOWERS ARE
EXPECTED THIS EVENING BUT MVFR CONDITIONS ARE NOT EXPECTED TO BE
WIDESPREAD. SOUTHWEST WINDS WILL PICK UP THIS MORNING WITH GUSTS
OVER 25 KNOTS MOST OF THIS AFTERNOON.
&&
.MARINE...
ISSUED AT 345 AM EDT THU OCT 11 2012
A GALE WARNING IS IN EFFECT WITH 35 TO 40 KNOT GALES ANTICIPATED
THROUGH THIS AFTERNOON. WAVE HEIGHTS COULD REACH 8 TO 12 FEET WITH
HIGHEST WAVES NORTH OF GRAND HAVEN. WINDS AND WAVES WILL GRADUALLY
DIMINISH TONIGHT AND PARTICULARLY FRIDAY AS HIGH PRESSURE BUILDS IN.
&&
.HYDROLOGY...
ISSUED AT 345 AM EDT THU OCT 11 2012
NO HYDRO ISSUES THROUGH FRIDAY. A STRONG LOW PRESSURE SYSTEM HAS
POTENTIAL TO BRING SOME HEAVY RAINFALL THIS WEEKEND WITH TOTAL
RAINFALL AMOUNTS OF AN INCH OR TWO WITH LOCALLY HIGHER AMOUNTS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MIZ037-043>046-
050>052-056>059-064>067-071>074.
LM...GALE WARNING UNTIL 6 PM EDT THIS EVENING FOR LMZ844>849.
&&
$$
UPDATE...DUKE
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
619 AM CDT THU OCT 11 2012
.SHORT TERM...
ISSUED AT 311 AM CDT THU OCT 11 2012
(TODAY THROUGH FRIDAY NIGHT)
WARM ADVECTION UNDER WAY OVER SOUTHWEST MISSOURI AT THIS TIME.
CLOUD DECK BETWEEN 5000-8000FT IS MOVING SLOWLY NORTHEAST TOWARD OUR
AREA. CLOUDS SHOULD OVERSPREAD CENTRAL MISSOURI BY LATE MORNING AND
ON INTO EASTERN MISSOURI EARLY IN THE AFTERNOON. EVEN THOUGH PRECIP
HAS YET TO DEVELOP...SHORT-RANGE MODELS CONTINUE TO PRINT OUT PRECIP
DUE TO THE STRONG WARM ADVECTION AND MOISTURE CONVERGENCE ON THE
850MB BAROCLINIC ZONE ACROSS SOUTHERN MISSOURI. FORECAST SOUNDINGS
ARE PRETTY STRONGLY CAPPED THOUGH SO WOULD EXPECT THAT PRECIP WILL
BE PRETTY SCATTERED. HRRR DEVELOPS ISOLATED TO WIDELY SCATTERED
PRECIP...SO THIS JIVES WELL WITH THAT THINKING. WARM ADVECTION WILL
CONTINUE TONIGHT OVER SOUTHERN MISSOURI AND A SUBTLE SHORTWAVE WILL
BRING ANOTHER CANADIAN HIGH AND A SHOT OF COOL AIR DOWN FROM THE
NORTHERN PLAINS INTO MISSOURI TO REINFORCE THE BAROCLINIC ZONE. THE
STRONG BAROCLINICITY AND CONTINUING LOW LEVEL JET COMBINED WITH THE
SHORTWAVE PASSING OVERHEAD SHOULD PRODUCE MORE WIDESPREAD RAIN AND
THUNDERSTORMS. THE LOW LEVEL JET AND MOISTURE CONVERGENCE STAYS
FOCUSED OVER SOUTHERN MISSOURI...SO HAVE BACKED DOWN TO CHANCE POPS
ALONG THE I-70 CORRIDOR TONIGHT BUT KEPT LIKELY DOWN OVER THE
OZARKS. LOW LEVEL JET CHANGES FOCUS TO THE GREAT PLAINS ON FRIDAY
WHICH SHOULD BRING THE RAIN OVER SOUTHEAST MISSOURI TO AN END. THE
AFOREMENTIONED CANADIAN HIGH MOVES OVER THE MID ATLANTIC FRIDAY
NIGHT WHICH TURNS LOW LEVEL FLOW TO THE SOUTH. THIS PUSHES A WARM
FRONT UP THROUGH OUR AREA INTO THE UPPER MIDWEST SETTING THE STAGE
FOR A WARM SATURDAY AND POTENTIALLY SEVERE WEATHER SATURDAY NIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 340 AM CDT THU OCT 11 2012(SATURDAY THROUGH WEDNESDAY)
WE SHOULD BE WELL INTO THE WARM SECTOR ON SATURDAY. NAM AND GFS
SHOW 14-16C AT 850MB SATURDAY AFTERNOON SO AM GOING AT OR ABOVE
UPPER RANGE OF GUIDANCE TEMPS. THE SYNOPTIC SETUP REMAINS
FAVORABLE FOR SEVERE WEATHER SATURDAY AFTERNOON AND NIGHT. THE
DETAILS IN THE MODELS ARE VERY SIMILAR AND HAVE BEEN VERY
CONSISTENT. DEEP LAYER SHEAR IN EXCESS OF 50KTS WITH A STRONG
SHORTWAVE AND LOW LEVEL MOISTURE WILL BE IN PLACE. CONVECTION LOOKS
TO DEVELOP OVER EASTERN KANSAS AND SHOULD MOVE INTO MISSOURI DURING
THE LATE AFTERNOON. FOR OUR AREA...BEST CHANCE FOR STORMS WILL BE
SATURDAY NIGHT. DAY 3 SEVERE OUTLOOK COVERS ALL OF CENTRAL AND
NORTHEAST MISSOURI AS WELL AS PARTS OF THE STL METRO. STILL...MODE
AND SEVERITY OF CONVECTION WILL LIKELY BE DECIDED BY AMOUNT OF
AVAILABLE INSTABILITY. STAY TUNED.
COLD FRONT ASSOCIATED WITH THE STORM WILL MOVE THROUGH SUNDAY
MORNING. COULD SEE SOME LINGERING SHOWERS AHEAD OF THE FRONT...BUT
IT LOOKS LIKE DRY AIR WILL SHUT THE PRECIP OFF SO WILL KEEP POPS OUT
OF THE FORECAST EXCEPT FOR EXTREME EASTERN ZONES FOR NOW. TEMPS
WILL COOL FROM SATURDAY`S HIGHS...BUT THE REALLY COLD AIR WILL STAY
LOCKED UP IN CANADA THIS TIME AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE WESTERN HALF OF THE U.S. WARM AND DRY CONDITIONS WILL CONTINUE
MONDAY AND TUESDAY UNDER THE INFLUENCE OF THE RIDGE. TEMPS SHOULD
BE AT OR ABOVE NORMAL IN THE 70S. NEXT CHANCE FOR RAIN WILL COME
WEDNESDAY AS ANOTHER SHORTWAVE DIPS INTO THE UPPER MIDWEST WHICH
WILL ALLOW THE LOW LEVEL JET TO RAMP UP OVER THE AREA AHEAD OF A
COLD FRONT.
CARNEY
&&
.AVIATION...
ISSUED AT 616 AM CDT THU OCT 11 2012
AREA OF STRATUS CONTINUES TO ADVANCE NORTHEAST AT 15KTS AND WILL
SPREAD ACROSS THE ENTIRE AREA BY MID AFTERNOON. AT THIS POINT
BELIEVE CEILING WILL REMAIN VFR UNTIL TONIGHT...WITH A LOWERING TO
MVFR LEVELS ALONG AND SOUTH OF INTERSTATE 70. APPEARS BEST CHANCES
OF PRECIPITATION WILL REMAIN SOUTH OF THE TERMINALS AT THIS TIME.
WINDS WILL BE SOUTHELRY TODAY WITH A WIND SHIFT TO THE NORTHWEST
TONIGHT AS A COLD FRONT SLIDES SOUTHEAST ACROSS THE FORECAST AREA.
SPECIFICS FOR KSTL...
VFR STRATUS WILL OVERSPREAD THE TERMINAL BY 16Z. CEILING WILL
LOWER TO MVFR LEVELS BY 07Z TONIGHT. BELIEVE RAIN WILL STAY SOUTH
OF TERMINAL AT THIS TIME.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 47 66 57 / 20 40 10 10
QUINCY 66 39 63 52 / 10 10 5 50
COLUMBIA 64 44 66 57 / 20 40 20 20
JEFFERSON CITY 63 46 66 57 / 20 40 20 20
SALEM 62 46 64 52 / 10 40 10 10
FARMINGTON 58 48 65 55 / 30 60 20 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS TULSA OK
1044 AM CDT THU OCT 11 2012
.DISCUSSION...
LOW LVL MOISTURE RETURN ON THE BACK SIDE OF THE SURFACE HIGH OVER
THE SOUTHEAST STATES HAS RESULTED IN WIDESPREAD LOW CLOUDS. THE
LATEST DATA INDICATES THAT THIS CLOUD COVER WILL STICK AROUND FOR
MUCH OF THE DAY...LIMITING HEATING. I HAVE LOWERED HIGHS TEMPS BY
A CATEGORY IN MOST PLACES. THE LATEST HRRR SUGGESTS THAT THE
MORNING SHOWERS AND ISOLD TSTORMS TO THE SOUTH AND EAST OF TULSA
WILL EVENTUALLY DISSIPATE THIS AFTERNOON AND SHOULD REMAIN QUIET
UNTIL TONIGHT. THUS I HAVE MADE SOME ADJUSTMENT TO THE
POPS...DECREASING THEM IN THE WEST. TEXT PRODUCTS HAVE BEEN SENT.
LACY
&&
.PREV DISCUSSION... /ISSUED 556 AM CDT THU OCT 11 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
WIDESPREAD MVFR CIGS SHOULD PERSIST THROUGH THE MORNING
HOURS...ALONG WITH WIDELY SCATTERED SHOWERS MAINLY FOR
THE ARKANSAS TAF SITES. EXPECT CIGS TO RISE TO VFR AFTER
18-20Z. THUNDERSTORM DEVELOPMENT LIKELY AT KBVO/KTUL/KRVS
KFYV AND KXNA AROUND 04-06Z...WITH SEVERE THUNDERSTORMS
POSSIBLE.
PREV DISCUSSION... /ISSUED 323 AM CDT THU OCT 11 2012/
DISCUSSION...
FRONTAL BOUNDARY...CURRENTLY LOCATED ACROSS FAR SOUTHERN ARKANSAS
THIS MORNING...HAS BEGUN TO LIFT BACK NORTH INTO SOUTHEAST
OKLAHOMA THIS MORNING WITH LOW LEVEL MOISTURE INCREASING. ISOLATED
SHOWERS/THUNDERSTORMS MAY DEVELOP LATER THIS MORNING AS THE LOW
LEVEL JET CONTINUES TO INCREASE WITH A LIMITED SEVERE THREAT ALONG
AND NORTH OF THE RETREATING WARM FRONT.
BETTER THUNDERSTORM CHANCES...INCLUDING THE THREAT FOR SEVERE
WEATHER...WILL OCCUR THIS EVENING INTO THE OVERNIGHT HOURS AS A
SECONDARY SURGE OF COOLER AIR MOVES TO THE OKLAHOMA/KANSAS BORDER
AND STALLS. MOISTURE POOLING ALONG THE FRONT WILL ALLOW THE
ATMOSPHERE TO BECOME MODERATELY UNSTABLE WITH 30-40 KNOT DEEP
LAYER SHEAR IN PLACE. LARGE HAIL WILL BE THE PRIMARY THREAT WITH
THE STRONGER STORMS OVERNIGHT...INCLUDING THE THREAT FOR LOCALLY
HEAVY RAINFALL.
MAIN FOCUS THEN SHIFTS TO STRONG UPPER LOW CURRENTLY OFF THE
CALIFORNIA COAST AND ITS POTENTIAL IMPACTS INTO THE WEEKEND. UPPER
LOW WILL QUICKLY LIFT NORTHEAST INTO THE CENTRAL PLAINS BY
SATURDAY. STRONG TO SEVERE THUNDERSTORMS WILL BE LIKELY SATURDAY
AFTERNOON INTO SATURDAY EVENING AS THE COLD FRONT SWEEPS EAST
THROUGH THE AREA. STRONG LOW LEVEL WIND FIELDS WILL DEVELOP AHEAD
OF FRONT AND WITH MODERATE INSTABILITY EXPECTED...ALL MODES OF
SEVERE WEATHER WILL BE POSSIBLE. THE SEVERE THREAT SHOULD END
SUNDAY MORNING AS CONVECTIVE LINE SWEEPS EAST.
FOR THE REMAINDER OF THE FORECAST...WARM/DRY CONDITIONS ARE
GENERALLY EXPECTED. ANOTHER COLD FRONT IS EXPECTED AROUND MID
WEEK...HOWEVER AS IT APPEARS NOW...LIMITED MOISTURE WILL KEEP
PRECIPITATION CHANCES LOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 75 68 82 66 / 10 80 60 20
FSM 72 65 81 63 / 30 50 30 10
MLC 79 66 83 66 / 20 30 20 10
BVO 76 60 78 63 / 10 80 60 40
FYV 67 60 78 61 / 20 80 60 10
BYV 66 58 74 61 / 20 80 60 10
MKO 74 65 81 64 / 20 60 30 10
MIO 70 61 78 63 / 20 80 60 20
F10 77 66 81 66 / 20 50 30 20
HHW 80 66 84 64 / 20 20 20 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...30
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1006 AM CDT THU OCT 11 2012
.DISCUSSION...UPDATED NEAR TERM POP GRIDS BASED ON LATEST
OBSERVATIONAL TRENDS. SHOWERS SOUTH OF HIDALGO AND CAMERON COUNTY
ARE LIFTING FROM AROUND 950MB...AND WILL LIKELY PERSIST FOR
ANOTHER HOUR OR TWO BEFORE DIMINISHING. CU STREAKS ALONG THE
IMMEDIATE COASTAL REGION ON VISIBLE SATELLITE POINT TO SEABREEZE
CONVERGENCE FORMING UP ON SCHEDULE THIS MORNING. MODIFIED OBSERVED
AND LAPS SOUNDINGS SHOW WE WILL ONLY NEED ABOUT 2000FT OF
MECHANICAL LIFTING TO GET CONVECTION TODAY WITH SLIGHTLY COOLER
TEMPERATURES AT 850 TO 925MB THAN YESTERDAY WITH JUST SLIGHTLY
BETTER MOISTURE. ANY SURFACE BASED PARCELS THAT MAKE IT TO
THUNDERSTORM STATUS WILL HAVE ABOUT 3000 J/KG OF CAPE WITH A THETA
E DIFFERENTIAL OF AROUND 35 K...SO GUSTY WINDS WILL BE POSSIBLE.
WITH A COLUMN PWAT AROUND 1.80 STORMS WILL ALSO BE EFFICIENT
RAINFALL PRODUCERS. WITH THE STRONGER SOUTHEAST WINDS TODAY STILL
EXPECT THAT WILL BE ISOLATED AT BEST FOR NOW. 14Z RAP...WHICH
SEEMS TO HAVE A GOOD HANDLE...09Z SREF AND 12Z HRRR USED
PARTIALLY TO ASSIST WITH LOCATION OF BEST RAINFALL CHANCES AND
TIMING. NEAR TERM DEWPOINTS AND SKY ALSO TWEAKED...BUT PACAKGE IS
IN GOOD SHAPE OVERALL. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 623 AM CDT THU OCT 11 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...STREAMER SHOWERS ARE ATTEMPTING TO MOVE INLAND NEAR THE
COAST THIS MORNING. EXPECT REMNANTS OF THESE SHOWERS TO PASS NEAR
IMMEDIATELY COASTAL AIRPORTS DURING THE NEXT COUPLE HOURS...WITH
TEMPO CIG REDUCTIONS TO AROUND 2000 FEET. SCT TO BKN CLOUDS AT
AROUND 3500 FT ARE EXPECTED BY MID TO LATE MORNING WITH SCATTERED
SHOWERS AND POSSIBLY A THUNDERSTORM DEVELOPING ALONG THE SEABREEZE
AND MOVING WEST. WINDS WILL JUMP TO 15G25KTS LATER THIS AFTERNOON
BEFORE REDUCING BACK TO AROUND 5KTS OVERNIGHT.
PREV DISCUSSION... /ISSUED 426 AM CDT THU OCT 11 2012/
SHORT TERM /TODAY THROUGH FRIDAY/...MIDLEVEL RIDGE SLOWLY
BUILDING ALOFT OVERHEAD DURING THE NEXT 36 HOURS. THIS WILL BE
COUNTERACTED BY SOUTHEAST FLOW AT THE SFC CONTINUING TO INCREASE
LLVL MOISTURE. PW VALUES ABOVE 1.8 INCHES AND TEMPERATURES IN THE
90S AREAWIDE WILL ALLOW THE SEABREEZE TO FORM AND DRIFT NEWD
ACROSS THE REGION TODAY. WINDS OF 15 TO 20KTS WILL MAKE THE
SEABREEZE A MORE DIFFUSE BOUNDARY...BUT SHOWERS WILL BE ABLE TO
POP UP THIS AFTERNOON...ALSO AIDED BY INSTABILITY FROM STREAMER
SHOWERS CURRENTLY ATTEMPTING TO MOVE ASHORE FROM THE SOUTHEAST.
TEMPERATURES WILL BE NEAR YESTERDAY/S HIGHS...IMPEDED SLIGHTLY BY
INCREASED MOISTURE. OF NOTE WERE YESTERDAY/S TEMPERATURES IN MFE
/96/ AND EBG /98/ WERE HIGHER THAN DEATH VALLEY CALIFORNIA /95/.
ANOTHER HOT AND HUMID DAY TOMORROW WITH ANOTHER ROUND OF SEABREEZE
SHOWERS.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY...EXTENDED DOES NOT
VARY MUCH FROM YESTERDAY WITH EXCEPTION TO THE ADDITION OF SLIGHT
CHANCE OF RAIN ACROSS THE NORTHERN TIER COUNTIES MONDAY AS A
WEAKENING COLD FRONT APPROACHES. OTHERWISE...HIGH PRESSURE TO
DOMINATE THROUGH THE COMING WEEKEND WITH HOT AND DRY WEATHER THEN
THE RIDGE BREAKS DOWN AS A BROAD LOW PRESSURE TROUGH DEVELOPS
ACROSS THE EASTERN TWO THIRDS OF THE COUNTRY.
FORECAST TRENDS WITH THE GFS WITH ENSEMBLE MEMBERS SHOWING A
NARROW VARIANCE THROUGH THE NEXT 7 DAYS. THE FIRST THREE DAYS GFS
AND ECMWF SHOW GOOD CONSISTENCY THROUGH THE WEEKEND BEFORE SOME
MID LEVEL PATTERN DIFFERENCES START DEVELOPING IN BY THE END OF
THE FORECAST PACKAGE.
MAIN FEATURES WE ARE KEEPING AN EYE ON ARE AN UPPER LOW OFF THE
CALIFORNIA COAST AND A STRONG MID LEVEL RIDGE PARKED OVER THE
WESTERN GULF. SURFACE PRESSURE TO LOWER ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THROUGH SATURDAY WITH A LOW LEVEL JET GAINING
STRENGTH. THIS WILL GENERATE WINDY CONDITIONS SATURDAY WITH GUSTS
UPWARDS OF 35 MPH. DO NOT THINK GRADIENT WILL BE STRONG ENOUGH FOR
A WIND ADVISORY WITH SURFACE HIGH OVER THE GULF NOT AS STRONG AS
WOULD LIKE TO SEE. THE SOUTHERLY FLOW PUMPS IN SOME MOISTURE
ACROSS THE REGION WITH TEMPERATURE PICKING RISING WELL ABOVE
NORMAL. THE MID LEVEL LOW LIFTS QUICKLY NORTHEAST DRAGGING A
PACIFIC FRONT ACROSS THE STATE. GFS AND ECMWF PLACE WITH FRONT
NEAR THE NORTHERN COUNTIES SUNDAY WHICH MIGHT BE CLOSE ENOUGH TO
WARRANT A FEW SHOWERS OR THUNDERSTORMS. GFS IS MUCH HIGHER ON THE
POPS THEN ECMWF SO A LOW BIAS ON RAIN CHANCES WERE ADDED ACROSS
THE NORTH. DOWN SOUTH MUCH OF THE SAME FOR NOW.
LITTLE CHANGE MADE TO THE LATTER HALF OF THE FORECAST WITH A
PERSISTENT WEAK MIDLEVEL NORTHWEST FLOW. AS MENTIONED ABOVE
FORECAST TRENDS TOWARDS THE GFS WITH ABOVE NORMAL TEMPERATURES AND
KEEPING ANY FRONTS WELL NORTH OF THE REGION UNTIL MAYBE THURSDAY OR
FRIDAY. EUROPEAN MODELS IS MORE AGGRESSIVE WITH THE TROUGH OVER THE
CENTRAL PLAINS AND IS MORE AGGRESSIVE WITH A FRONT THROUGH THE
AREA WEDNESDAY. WILL DETER FROM THIS SOLUTION FROM NOW UNTIL
BETTER MODEL CONSISTENCY IS SEEN.
MARINE...TODAY THROUGH FRIDAY...WINDS ACROSS THE GULF WATERS WILL
INCREASE TO 15 TO 20 KNOTS TODAY...WITH SEAS FLUCTUATING BETWEEN 3
AND 5 FEET THIS AFTERNOON. THESE CONDITIONS ARE FORECAST TO CONTINUE
THROUGH THURSDAY NIGHT INTO FRIDAY. ADVISORIES ARE NOT CURRENTLY
FORECAST...BUT SMALL CRAFT SHOULD EXERCISE CAUTION.
FRIDAY NIGHT THROUGH MONDAY...SMALL CRAFT ADVISORY ARE BECOMING
MORE PROBABLE FRIDAY NIGHT THROUGH SATURDAY AS THE PRESSURE
GRADIENT STRENGTHENS AS SURFACE PRESSURES LOWER SIGNIFICANTLY OVER
NORTHWEST TEXAS IN RESPONSE TO AN UPPER LOW MOVING THROUGH THE
SOUTHERN ROCKIES. STRONG WIND AND BUILD WIND WAVES ARE IN ORDER
THROUGH SATURDAY NIGHT. WINDS AND SEAS BEGIN TO RELAX SUNDAY AND
BECOME LOWER MONDAY AS THE LOW LIFTS OUT AND A WEAK FRONT STALLS
JUST NORTH OF THE REGION.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/66
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
942 AM CDT THU OCT 11 2012
.SHORT TERM...UPDATED FOR TODAY
942 AM CDT THU OCT 11 2012
COLD FRONT MAKING PROGRESS SOUTHWARD ACROSS THE AREA WITH MID-LEVEL
SHORTWAVE MOVING EAST ACROSS LAKE SUPERIOR. RADAR SHOWING SOME
LIGHT SHOWER/SPRINKLE ACTIVITY CURRENTLY ALONG AND IMMEDIATELY
BEHIND THE SURFACE FRONT. RAP SHOWING INCREASING FRONTOGENESIS
THIS AFTERNOON CENTERED AROUND 700MB JUXTAPOSED WITH FAVORED RIGHT
ENTRANCE REGION OF THE 300MB JET MOVING OVERHEAD. BASED ON THIS
FORCING SIGNAL...HAVE ADDED ISOLATED SHOWER MENTION ALONG AND
SOUTH OF I-90 FOR THIS AFTERNOON. TEMPERATURE-WISE...LIKELY NOT TO
SEE TOO MUCH MOVEMENT TODAY WITH CLOUD AND COLD AIR ADVECTION.
WILL HAVE UPDATED FORECAST OUT SOON.
.PREVIOUS SHORT TERM ISSUED 347 AM...THROUGH SATURDAY NIGHT
MAIN FORECAST CONCERNS THIS PACAGE...SHRA/TSRA CHANCES/RAIN AMOUNTS
FRI NIGHT THRU SAT NIGHT...TEMPERATURES THRU THE PERIOD.
DATA ANALYSIS AT 06Z HAD A WAVE OF LOW PRESSURE MOVING EAST ACROSS
CENTRAL MN. RATHER STRONG 3HR PRESSURE FALL/RISE COUPLET WITH THIS
LOW. STRONGEST OF FORCING/LIFT AND SATURATION WITH THIS FEATURE WAS
ACROSS NORTHERN MN/FAR NORTHERN WI...WHERE A BAND OF -RA/-SN WAS
MOVING QUICKLY EAST THRU THE KDLH AREA. ACROSS WEST-CENTRAL MN AND
ALONG THE SD/ND BORDER WEAK 850-700MB FN CONVERGENCE WAS PRODUCING A
BAND OF PATCHY -RA/SCT -SHRA. ALL THIS TRANSLATING EAST-SOUTHEAST
EARLY THIS MORNING. SOUTH OF THE LOW/TRAILING COLD FRONT...SKIES
WERE CLEAR ACROSS IA/FAR SOUTHERN MN INTO FAR SOUTHERN WI. BRISK/
INCREASING SOUTH WINDS AHEAD OF THE LOW/FRONT KEEPING TEMPS WARMER
EARLY THIS MORNING...EVEN UNDER THE CLEAR SKIES.
11.00Z MODELS LOOK TO HAVE INITIALIZED QUITE WELL. SOLUTIONS SIMILAR
THRU 48HRS...THEN BEGIN TO DIVERGE AS THE SOUTHWEST CONUS SYSTEM
TAKES AIM AT THE UPPER MIDWEST FOR FRI NIGHT THRU SAT NIGHT. WHAT
HAD BEEN A TIGHT CONSENSUS NOW TAKES 2 CAMPS AS THE TROUGH/ENERGY
EJECTS INTO/CROSSES THE CENTRAL CONUS. DPROG/DT OF 500MB HGTS AT
11.00Z SHOWED THE MODEL RUNS OF 09.00Z AND 10.00Z ALL VERIFIED WELL
ACROSS NOAM/EASTERN PAC...CONVERGING ON A TIGHT COMPROMISE CONSENSUS
OF THE EARLIER RUNS. SOLUTIONS SIMILAR WITH A TIGHT CONSENSUS AND
GOOD RUN-TO-RUN CONSISTENCY THRU TONIGHT. BY SAT MORNING BETWEEN
MODEL AND RUN-TO-RUN CONSISTENCY DECREASES AS THE TROUGH/LOW OF
INTEREST MOVES THRU THE ROCKIES INTO THE CENTRAL PLAINS. TREND IS
TOWARD MORE OF SPLIT OF THE SHORTWAVE ENERGY BY SAT MORNING.
SOLUTIONS CONTINUE TO DIVERGE WITH THE EVOLUTION/TRACK OF THE MID
LEVEL LOW/TROUGH AS IT LIFTS INTO THE UPPER MIDWEST BY SUN MORNING.
CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED MODELS ALL QUITE GOOD
WITH THE MN LOW AND TRAILING COLD FRONT. MODELS ALL QUITE REASONABLE
WITH THE 00-06Z PRECIP ACROSS NORTHERN MN/WI WITH GFS/ECMWF BETTER
ON THE LIGHT PRECIP OVER WEST CENTRAL MN/ALONG SD/ND BORDER. PER WV
IMAGERY ALL LOOKED GOOD WITH THE NOAM/EASTERN PAC SHORTWAVE DETAILS.
WILL LEAN TOWARD ECMWF/GFS TODAY...THEN CONTINUE TO FAVOR A MODEL/
ENSEMBLE CONSENSUS FOR TONIGHT THRU SAT NIGHT. SHORT TERM FCST
CONFIDENCE GOOD THRU FRI BUT NOW AVERAGE WITH THE STORM SYSTEM FOR
FRI NIGHT THRU SAT NIGHT.
IN THE SHORT TERM...MN LOW WILL CONTINUE TO MOVE QUICKLY EAST THIS
MORNING AND DRAG THE COLD FRONT INTO/ACROSS THE AREA. BAND OF WEAK
FORCING/850-700MB FN CONVERGENCE BEHIND THE FRONT WILL SLIDE ACROSS
THE NORTHERN PARTS OF THE FCST AREA THIS MORNING. WITH OBS UNDER
THE BAND OF PRECIP IN WEST CENTRAL MN CONTINUING TO REPORT
OCCASIONAL -RA AND GFS/ECMWF AND LCL/REGIONAL WRF MODELS PRODUCING
SOME LIGHT PRECIP IN THE NORTH END OF THE FCST AREA THIS MORNING...
EXPANDED SMALL -RA CHANCE TO ALONG/NORTH OF HWY 10 THRU 18Z. BAND
OF POST-FRONTAL CLOUDS WILL SINK SOUTH ACROSS THE AREA AS WELL AND
RAISED SKY COVER/LOWERED HIGHS A BIT FOR TODAY. CLOUDS CLEAR OUT
LATE THIS AFTERNOON/EARLY THIS EVENING AS THE SFC-850MB RIDGE BUILDS
INTO THE AREA AND MDT/STRONG 700-500MB SUBSIDENCE SPREADS OVER THE
AREA. SFC HIGH IS CENTERED OVER THE AREA AT 12Z FRI...WITH LIGHT
WINDS/CLEAR SKIES AND COOL 925-850MB TEMPS. LOOKS LIKE LOWS
EVERYWHERE WILL DROP INTO AT LAST THE 20S...WITH WIDESPREAD
FREEZING TEMPS FINALLY ENDING THE GROWING SEASON IN THOSE ISOLATED
LOCATIONS THAT HAVE ESCAPED FROST/FREEZING SO FAR THIS FALL.
FROST/FREEZE HEADLINES HAVE BEEN TERMINATED FOR THE SEASON...SO NO
HEADLINE WILL BE ISSUED FOR LATE TONIGHT/EARLY FRI MORNING.
THE HIGH MOVES QUICKLY EAST OF THE AREA FRI AS LEE TROUGHING
DEVELOPS FROM MT TO CO. BROAD LOW LEVEL WARM ADVECTION ALREADY
SPREADS ACROSS THE AREA FRI AS THE GRADIENT TIGHTENS...WITH 925MB
TEMPS IN THE +4 TO +7C RANGE BY 00Z SAT. AIRMASS OVER THE AREA
REMAINS DRY THRU FRI...WITH PLENTY OF SUNSHINE AND A DIURNAL TEMP
RISE OF SOME 25-30F FOR MOST AREAS.
LEAD 925-700MB WARM ADVECTION/ISENTROPIC LIFT AND MOISTURE
TRANSPORT/THETA-E CONVERGENCE SPREAD QUICKLY NORTHEAST ACROSS THE
AREA FRI NIGHT. MODELS ALL REMAIN QUITE CONSISTENT WITH THIS
SIGNAL. PREVIOUS GRID SET TRENDED THE 00-03Z PERIOD FRI EVENING
DRY AND THIS LOOKS GOOD...WITH THE MOISTURE/LIFT ARRIVING AROUND
MIDNIGHT. WITH THE CONSISTENT MOISTURE/WARM ADVECTION SIGNAL RAISED
RAIN CHANCES TO 60-90 PERCENT AFTER MIDNIGHT FRI NIGHT. GIVEN THE
STRENGTH OF THE LIFT AND MODELS SHOWING SOME CAPE LIFTING PARCELS IN
THE 800-700MB LAYER...SOME THUNDER LOOKS TO ACCOMPANY THE SHRA AS
THEY LIFT NORTHEAST ACROSS THE AREA FROM LATE EVENING ON.
ON SAT MODELS BEGIN TO DIFFER ON THE DETAILS OF WHERE THE STRONGER
FORCING/LIFT WILL MOVE ACROSS THE FCST AREA. SPLITTING GFS SOLUTION
KEEPS THE STRONGER FORCING OVER THE SOUTHEAST HALF OF THE FCST AREA
SAT INTO SAT NIGHT WHILE OTHER MODELS CONTINUE TO SPREAD STRONG
FORCING ACROSS THE ENTIRE FCST AREA AS THE SFC-MID LEVEL TROUGH
MOVES INTO/ACROSS THE REGION. 90-100 PERCENT SHRA/TSRA CHANCES
ACROSS THE FCST AREA SAT STILL LOOK WARRANTED. DEEPER OF THE
MOISTURE LIFT DOES MOVE EAST OF THE AREA SAT NIGHT. CARRIED HIGHEST
SHRA/TSRA CHANCES OF 60-90 PERCENT SAT EVENING...TRENDING DOWNWARD
AFTER MIDNIGHT AS THE MID LEVEL TROUGH AXIS PASSES.
HIGH TEMPS ON SAT...RESULTING INSTABILITY AND SEVERE TSRA RISK
REMAIN THE SOME OF THE MORE UNCERTAIN ELEMENTS AS THIS SYSTEM
PASSES. MODEL SOUNDINGS FOR SAT SHOW EITHER A DEEPLY SATURATED
COLUMN OR AT LEAST SATURATED BELOW 800MB. FCST GRIDS ARE CARRYING
CLOUDY SKIES SAT...AND THIS BLENDS WILL WITH ALL NEIGHBORS. STILL
APPEARS THE SFC LOW AND ATTENDANT FRONTS WILL BE WEST/NORTH OF THE
FCST AREA UNTIL AFTER 00Z SUN. THIS LIKELY TO LIMIT BOUNDARY LAYER
INVOLVEMENT IN THE SEVERE STORM RISK. APPEARS STRONGER INSTABILITY
OF UP TO 500-1000 J/KG WILL BE ELEVATED. GIVEN THE BROAD FORCING
FOR ASCENT AHEAD OF THE SFC-MID LEVEL TROUGH AND STRONGER SHEAR...
ISOLATED SEVERE TSRA CANNOT BE RULED OUT WITH SWODY3 OKAY FOR NOW.
PW VALUES STILL PROGGED TO BE IN THE 1.5 INCH RANGE LATE FRI NIGHT
INTO SAT EVENING...WITH ANY TSRA CAPABLE OF PRODUCING HEAVY
DOWNPOURS. WITH THE ANTECEDENT DRY CONDITIONS...ANY FLOODING OR
FLASH FLOODING THREAT LOOKS MINIMAL.
GENERALLY FAVORED A BLEND OF THE NUMERICAL GUIDANCE HIGHS/LOWS FOR
TODAY THRU SAT NIGHT. WITH PLENTY OF CLOUDS/SHRA/TSRA EXPECTED
SAT...DID FAVOR COOLER OF GUIDANCE HIGHS.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
347 AM CDT THU OCT 11 2012
11.00Z MEDIUM RANGE MODELS SHOW THE TROUGH/LOW TO BE PROGRESSIVE
SUNDAY...EXITING EAST OF THE AREA BY AFTERNOON. LIMITED SHRA
CHANCES SUN MAINLY TO THE MORNING HOURS. DECENT MODEL CONSISTENCY
FOR BROAD 500MB TROUGHING TO REMAIN OVER THE AREA THRU SUN NIGHT.
ECMWF DROPS A STRONGER SHORTWAVE ACROSS THE AREA IN NORTHWEST FLOW
SUN NIGHT...AND LEFT A SMALL -RA CHANCE ACROSS THE NORTH END OF THE
FCST AREA. MODERATE CONSENSUS FOR WEAK SHORTWAVE RIDGING TO BUILD
THE AREA MON FOR A DRY DAY. PATTERN REMAINS UNSETTLED THRU THE
MIDDLE OF NEXT WEEK AS THE FLOW BECOMES QUASI-ZONAL ACROSS THE
NORTHERN CONUS AND MODELS STRUGGLE WITH THE TIMING/STRENGTH OF
SHORTWAVES THRU THE FLOW. LOOSE CONSENSUS FOR A STRONGER SHORTWAVE
TO CARVE OUT A TROUGH OVER THE UPPER MIDWEST BY WED. SOME SHRA
CHANCES IN THE 20-40 PERCENT RANGE TUE NIGHT/WED...PER THE
MODEL/ENSEMBLE CONSENSUS...LOOK GOOD FOR NOW. WITH THE MORE EAST-
WEST FLOW AND MAIN STORM TRACK ALONG THE US/CAN BORDER...TEMPS FOR
SUN-WED CONTINUE TO TREND NEAR OR ABOVE NORMAL AND THIS WELL
DEPICTED BY THE MODEL CONSENSUS GRID SET.
&&
.AVIATION...TODAY AND TONIGHT
645 AM CDT THU OCT 11 2012
A LOW PRESSURE SYSTEM AND COLD FRONT ARE MOVING THROUGH THE REGION
WITH THE FRONT PASSING THROUGH RST AND LSE THIS MORNING. A FEW
SPRINKLES HAVE BEEN REPORTED THOUGH THEY SHOULD NOT CAUSE ANY
VISIBILITY RESTRICTIONS AT EITHER TERMINAL. CLOUD COVER IS THE
MAIN QUESTION...PARTICULARLY WITH IF ANY MVFR CEILINGS CAN MAKE IT
INTO RST/LSE. LOCAL OBSERVATIONS AND FORECAST GUIDANCE SUGGEST
THAT THE BATCH OF MVFR 2-3KFT CEILINGS SHOULD STAY NORTH OF THE
TWIN CITIES AND TRACK EAST ALONG WITH THE SYSTEM.
OTHERWISE...WINDS WILL SWING AROUND TO THE NORTHWEST AS THE FRONT
PASSES AND REMAIN GUSTY UP TO AROUND 20KTS TODAY. A RIDGE OF HIGH
PRESSURE WILL MOVE INTO THE REGION TONIGHT WHICH WILL HELP TO
CLEAR OUT THE SKIES AND LIGHTEN THE WINDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
347 AM CDT THU OCT 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATED SHORT TERM...DAS
PREVIOUS SHORT TERM...RRS
LONG TERM....RRS
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
347 PM MDT THU OCT 11 2012
.SHORT TERM... FRONT PASSED ACROSS PLAINS DURING THE MORNING HOURS
WITH NORTHEAST WINDS PERSISTING THOUGH SLOWING DECREASING. HIGH
LEVEL MOISTURE IN PLACE OVER AREA WITH SOME CUMULUS ACROSS MOUNTAINS
ABOVE WEAK INVERSION. RADAR SHOWING SOME WEAK ECHOES OVER ZONE 34
WHERE LAPS SURFACE ANALYSIS INDICATING SOME CAPE. LATEST RUC KEEPS
SOME CAPE IN THIS AREA DURING THE EVENING...AND WILL CONTINUE WITH A
SLIGHT CHANCE OF THUNDERSTORMS THERE. OTHERWISE...SHOULD CONTINUE TO
SEE AN INCREASE IN MID AND HIGH LEVEL MOISTURE TONIGHT AS UPPER LOW
MOVES INTO THE DESERT SOUTHWEST. MODEL CROSS SECTIONS SHOW A GRADUAL
LOWERING OF THE MOISTURE AFTER MIDNIGHT ALONG WITH SOME INCREASE IN
MID LEVEL QG ASCENT. SOME SHOWERS POSSIBLE ACROSS THE MOUNTAINS
OVERNIGHT. AIRMASS STILL FAIRLY WARM SO SNOW LEVEL WILL BE RATHER
HIGH WITH NO ACCUMULATION. ACROSS PLAINS...WINDS TO BECOME SOUTHEAST
AND WEAKEN DURING THE EVENING WITH ONLY A SLIGHT INCREASE IN LOW
LEVEL MOISTURE AFTER MIDNIGHT. WITH THE LIGHT WINDS AND COOLER
AIRMASS...DECIDED TO KEEP THE MENTION OF PATCHY FOG ACROSS THE
NORTHERN SECTIONS OF THE URBAN CORRIDOR. ON FRIDAY...MODES SHOW
UPPER LOW MOVING INTO SOUTHERN ARIZONA BY 18Z AND OVER SOUTHEAST
UTAH LATE IN THE AFTERNOON. SOUTHWEST FLOW ALOFT TO BECOME SOUTHERLY
WHICH WILL BRING MORE MOISTURE ACROSS THE AREA. THOUGH FLOW NOT
FAVORABLE FOR GOOD MOUNTAIN OROGRAPHICS...DECENT MOISTURE ALONG WITH
INCREASING QG VERTICAL MOTION AND INSTABILITY SUFFICIENT SHOULD BE
SUFFICIENT TO GENERATE NUMEROUS SHOWERS ALONG WITH SOME
THUNDERSTORMS ACROSS THE MOUNTAINS DURING THE AFTERNOON. AIRMASS
STILL FAIRLY WARM THROUGH THE AFTERNOON AND DESPITE THE POTENTIAL
FOR SOME EVAPORATIVE COOLING...SNOW LEVEL SHOULD REMAIN FAIRLY HIGH.
ANY ACCUMULATION TO BE CONFINED TO ELEVATIONS ABOVE 12000 FEET. AS
FOR PLAINS...SURFACE WINDS TO BECOME SOUTHEAST BY THE AFTERNOON WITH
THE POSSIBLE DEVELOPMENT OF A DENVER CYCLONE. THE SOUTHERLY FLOW
WILL ADVECT LOW LEVEL MOISTURE NORTHWARD. MODELS GENERATE CAPES OF
AROUND 300 J/KG ACROSS PALMER DIVIDE DURING THE AFTERNOON...LESS
FURTHER NORTH. SO BEST CHANCE OF STORMS TO BE ALONG PALMER DIVIDE
NORTHEAST INTO SOUTHERN WASHINGTON COUNTY. GUIDANCE TEMPERATURES
FAIRLY CLOSE ACROSS THE AREA THOUGH COULD BE A BIT TOO WARM BASED ON
POTENTIAL CLOUD COVER.
.LONG TERM...THE UPPER CLOSED LOW IS OVER THE NORTHEAST CORNER OF
COLORADO AT 12Z SATURDAY. THE UPPER TROUGH AXIS GETS EAST OF THE
CWA BY EARLY SATURDAY AFTERNOON. NORTHWESTERLY FLOW ALOFT WILL
DOMINATE AFTER TROUGH PASSAGE THROUGH SUNDAY NIGHT. THERE IS PRETTY
DECENT UPWARD SYNOPTIC SCALE ENERGY PROGGED ON THE QG VERTICAL
VELOCITY FIELDS FRIDAY NIGHT INTO SATURDAY MORNING. BY 18Z...PRETTY
STRONG DOWNWARD MOTION IS EXPECTED. BY 06Z SATURDAY NIGHT THROUGH
SUNDAY NIGHT...THERE IS BENIGN ENERGY IN THE SYNOPTIC SCALE. THE
BOUNDARY LAYER FLOW IS PROGGED TO BE DOWNSLOPING AS THE TROUGH
PASSES SATURDAY MORNING. THERE IS A BRIEF SHOT OF FAIRLY STRONG
NORTHWESTERLIES SATURDAY MORNING. THE DOWNSLOPING RELAXES BY
SATURDAY EVENING...WITH NORMAL DIURNAL PATTERNS EXPECTED THE REST OF
THE NIGHT THROUGH SUNDAY NIGHT. FOR MOISTURE...IT IS DEEP OVER THE
MOUNTAINS FRIDAY NIGHT THROUGH SATURDAY. EVEN SATURDAY NIGHT IT IS
PRETTY GOOD...BUT DECREASES SUNDAY MORNING. FOR THE PLAINS...
MOISTURE IS ONLY FAIR FRIDAY NIGHT...THAT AREA IS IN THE DRY SLOT OF
THE MID LATITUDE CYCLONE. MOISTURE GETS BETTER ON SATURDAY ON THE
BACKSIDE OF THE CLOSED LOW...AND IT LINGERS AROUND SATURDAY EVEN
OVER THE EASTERN HALF OF THE PLAINS. ON SUNDAY...MOISTURE DECREASES
OVER ALL THE CWA...SUNDAY NIGHT TOO. PRECIPITABLE WATER VALUES ARE
IN THE 0.40 TO 0.60 INCH RANGE LATER FRIDAY NIGHT AND SATURDAY
...THEN THEY DECREASE ON SUNDAY. THERE IS SOME CAPE OVER THE
EASTERN HALF OF THE PLAINS FRIDAY EVENING...VALUES ARE UP TO 500
J/KG. THAT IS IT FOR CAPE...THERE IS NONE SATURDAY OR SUNDAY FOR
THE CWA. FOR MOUNTAIN POPS...PRECIPITATION IS A VERY GOOD BET
FRIDAY NIGHT INTO SATURDAY EVENING...INITIALLY WITH THE SYNOPTIC
SCALE ENERGY OF THE CLOSED LOW...THEN WITH ORTHOGRAPHIC ENHANCEMENT
BY SATURDAY AFTERNOON. SO WILL GO WITH 60-80%S FRIDAY NIGHT INTO
SATURDAY EVENING. THEN DECREASE THEM DOWN TO NOTHING BY SUNDAY
MORNING SOMETIME. FOR THE PLAINS...THE FRONT RANGE AREA WILL HAVE
DRY SLOTTING...THEN PRETTY DECENT DRYING FROM DOWNSLOPING...SO POPS
WILL BE MINIMAL. BETTER POPS ARE EXPECTED FURTHER EAST...BUT NO
"LIKELY"S. WILL KEEP POPS GOING OVER THE FAR EAST INTO SATURDAY
NIGHT. SUNDAY AND SUNDAY NIGHT ARE DRY. WILL NOT GO WITH ANY
HIGHLIGHTS RIGHT NOW. NOT SURE IF THERE WILL BE ENOUGH MOISTURE FOR
ADVISORY AMOUNTS. FOR TEMPERATURES...SATURDAY`S HIGHS ARE SIMILAR
TO FRIDAY`S. SUNDAY`S HIGHS ARE 1-3 C WARMER THAN SATURDAY`S. FOR
THE LATER DAYS...MONDAY THROUGH THURSDAY...NORTHWESTERLY FLOW ALOFT
WILL CONTINUE OVER THE CWA ALL FOUR DAYS. FROM 12Z TUESDAY THROUGH
WEDNESDAY AFTERNOON...THE FLOW ALOFT IS WELL OVER 100 KNOTS. A COLD
FRONT IS PROGGED TO MOVE IN TUESDAY NIGHT AS WELL. MOISTURE IS VERY
SPARSE.
&&
.AVIATION...NORTHEAST SURFACE WINDS TO WEAKEN AND SHIFT TO THE
SOUTHEAST DURING THE EVENING TRANSITIONING TO DRAINAGE FLOW
OVERNIGHT. SLIGHT CHANCE FOR SOME PATCHY FOG DEVELOPING IN THE
15Z-18Z TIME FRAME NORTH OF THE DENVER AREA...SHOULD NOT AFFECT AREA
AIRPORTS. WINDS TO SHIFT TO THE SOUTHEAST BY 18Z FRIDAY WITH THE
POTENTIAL FOR THE DEVELOPMENT OF A DENVER CYCLONE ACROSS SOUTHERN
WELD COUNTY. THUS WINDS COULD BE NORTHWEST AT KBJC AND SOUTHERLY AT
KDEN AND KAPA. HIGH LEVEL MOISTURE WILL INCREASE OVERNIGHT ALONG
WITH SOME MID LEVEL MOISTURE. BY 18Z FRIDAY...LOW LEVEL MOISTURE TO
SPREAD ACROSS PLAINS WITH A SLIGHT CHANCE FOR RAIN SHOWERS. VFR
CONDITIONS TO PREVAIL...WITH POTENTIAL FOR CEILINGS AROUND 6000 FEET
AGL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D_L
LONG TERM....RJK
AVIATION...D_L
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
135 PM EDT THU OCT 11 2012
.SYNOPSIS...
17Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RATHER UNAMPLIFIED UPPER
LEVEL PATTERN OVER MUCH OF THE CONUS. MAIN NORTHERN STREAM FLOW
ARRIVES OVER THE BRITISH COLUMBIA COAST OVER TOP OF A REX BLOCK
PATTERN AND THEN RIDES ALONG THE US/CANADIAN BORDER ALONG THE
SOUTHERN PERIPHERY OF AN ELONGATED TROUGH IN PLACE OVER
CENTRAL/EASTERN CANADA. CLOSER TO HOME...UPPER LEVEL RIDGING OVER
THE GULF OF MEXICO IS BEGINNING TO AMPLIFY TO THE NORTH AND
NORTHEAST IN RESPONSE TO HEIGHT FALLS SPREADING INTO THE SW STATES
AHEAD OF A POTENT UPPER LOW ON THE SOUTHERN END OF THE REX BLOCK.
THIS RIDGING WILL CONTINUE TO EXPAND OVER OUR REGION AND HELP EXTEND
THE STRETCH OF DRY AND PLEASANT WEATHER INTO THE WEEKEND. 12Z KTBW
SOUNDING SHOWS A DRY PROFILE THROUGH ALMOST ALL OF THE TROPOSPHERE
WITH A SUBSIDENCE INVERSION AT 900MB AND A PW UNDER 1".
AT THE SURFACE...FORECAST AREA RESIDES WITHIN A LOW LEVEL EASTERLY
FLOW AROUND THE SOUTHERN PERIPHERY OF 1027MB HIGH PRESSURE CENTERED
OVER THE EASTERN TN VALLEY. DUE TO NEARLY 100% OF THE POSSIBLE
INSOLATION...TEMPERATURES HAVE REBOUNDED INTO THE LOWER TO MIDDLE
80S...ON THEIR WAY TO LATE AFTERNOON HIGHS IN THE MIDDLE TO UPPER
80S. A FEW-SCT SHALLOW CU FIELD HAS DEVELOPED IN SPOTS...HOWEVER
CROSS-SECTION PLOTS SHOW THAT LOW LEVEL MOISTURE IS VERY SHALLOW
WITH THETA-E VALUES WELL BELOW 320K ABOVE 850MB. THESE CONDITIONS
WILL PREVENT ANY SIGNIFICANT VERTICAL GROWTH AND KEEP OUR SKIES
PARTLY TO MOSTLY SUNNY THROUGH THE DAYLIGHT HOURS.
&&
.SHORT TERM (TONIGHT THROUGH SATURDAY)...
"CHAMBER OF COMMERCE" WEATHER WILL CONTINUE ALONG THE FLORIDA WEST
COAST THROUGH FRIDAY WITH SEASONABLE TEMPERATURES...AMBLE
SUNSHINE...AND DRY CONDITIONS.
TONIGHT...FEW-SCT CU QUICKLY DISSIPATE TOWARDS SUNSET PROVIDING
MOSTLY CLEAR/CLEAR SKIES INTO THE OVERNIGHT. THE GRADIENT WILL
TIGHTEN WHICH SHOULD HELP PREVENT A SIGNIFICANT AMOUNT OF
RADIATIONAL COOLING/RADIATION FOG LATE TONIGHT...HOWEVER STILL
EXPECTING NORMALLY COLDER AND INLAND LOCATIONS TO BOTTOM OUT IN THE
60S BY SUNRISE. A FEW OF THE COOLEST SPOTS...ESPECIALLY NORTH OF
BROOKSVILLE MAY BRIEFLY REACH THE UPPER 50S.
FRIDAY/FRIDAY NIGHT...ANOTHER PLEASANT AND DRY DAY ON TAP.
TEMPERATURES AND SKY CONDITIONS WILL BE VERY SIMILAR TO WHAT IS
OCCURRING TODAY. ONLY REAL DIFFERENCE WILL BE A SLIGHTLY
STRONGER/MORE GUSTY EAST/NE BREEZE DURING THE LATE MORNING/AFTERNOON
HOURS DUE TO DIURNAL MIXING OF SOME STRONGER MOMENTUM NEAR THE TOP
OF THE BOUNDARY LAYER COMPARED TO TODAY. FRIDAY NIGHT WILL SEE A
REINFORCING AND EVEN STRONGER RIDGE OF HIGH PRESSURE BUILD OVER AND
DOWN THE EASTERN SEABOARD RESULTING IN AN EVEN STRONGER PRESSURE
GRADIENT ACROSS THE PENINSULA. THIS TIGHTER GRADIENT ALONG WITH A
SLIGHT INCREASE IN SURFACE MOISTURE OFF THE ATLANTIC SHOULD KEEP LOW
TEMPS A COUPLE DEGREES COOLER THAN WHAT WE ARE FORECASTING FOR
TONIGHT.
SATURDAY...GENERALLY DRY AND SEASONABLE SENSIBLE WEATHER. THE
TIGHTER PRESSURE GRADIENT WILL CONTINUE THE INCREASE IN DIURNAL
GUSTY WINDS DURING THE LATE MORNING AND AFTERNOON...WITH FREQUENT
GUSTS OF 20 TO 25 MPH APPEARING LIKELY. OF NOTE...GFS/NAM BOTH
SHOWING (TO SOME DEGREE) A SURGE IN LOW LEVEL MOISTURE BELOW 700MB
ARRIVING WITHIN THE NE FLOW INTO THE SOUTHERN HALF OF THE PENINSULA
LATE FRIDAY NIGHT AND SATURDAY. FOR NOW WILL ONLY SHOW AN INCREASE
IN COVERAGE WITH RESPECT TO THE DIURNAL CUMULUS FIELD TO THE SOUTH
OF I-4. NAM IS HINTING AT SOME SHOWER POTENTIAL DOWN TOWARD FT MYERS
ASSOCIATED WITH THIS SURGE. THIS SEEMS UNLIKELY FOR THE WEST COAST
OF FLORIDA GIVEN THE SHALLOW NATURE OF THE MOISTURE. MORE LIKELY TO
SEE ANY FORCED SPEED CONVERGENCE SHOWERS OVER TOWARD THE SOUTHEAST
COAST OF THE STATE...BUT WILL CONTINUE TO MONITOR WITH FUTURE NWP
GUIDANCE. FOR NOW WILL KEEP POPS AT SILENT 10% DOWN TOWARD FT MYERS
AND LEAVE SHOWER MENTION OUT OF THE FORECAST.
&&
.LONG TERM (SATURDAY NIGHT - WEDNESDAY)...
AN UPPER LEVEL RIDGE INITIALLY ACROSS THE GULF REGION FLATTENS
AND THEN SHIFTS WEST AS UPPER LEVEL TROUGHING SETTLES IN ACROSS
THE EASTERN U.S. MON AND RESIDES THERE THROUGH THE REMAINDER OF
THE PERIOD. A HIGH PRESSURE CENTER OFF THE MID-ATLANTIC COAST
MOVES EAST THROUGH MON AS IT RIDGES BACK TO THE EAST GULF. THIS
RIDGE BEGINS TO WEAKEN MON AS A FRONTAL BOUNDARY SAGS INTO THE
SE U.S. THE BOUNDARY STALLS AND WASHES OUT NORTH OF THE AREA
TUE AS HIGH PRESSURE MOVES IN FROM THE WEST WED. MEANWHILE A LOW
PRESSURE AREA MOVES NORTH OVER THE ATLANTIC...ALONG OR EAST OF
LONGITUDE 70...FROM NEAR HISPANIOLA.
THE ATMOSPHERE REMAINS FAIRLY DRY AND WITH LIMITED ENERGY
AVAILABLE WILL KEEP THE FORECAST RAIN FREE. TEMPERATURES RUN
ABOVE NORMAL ALTHOUGH THEY WILL DIP A DEGREE OR TWO THROUGH THE
PERIOD. ROBUST EASTERLY WINDS BEGIN TO DIMINISH MON AND BECOME
MORE NORTHERLY BUT WITH AFTERNOON SEA BREEZES.
&&
.AVIATION...
VFR NEXT 24 HOURS. LOW CHANCE OF BRIEF MVFR VISIBILITIES MAINLY AT
LAL AND PGD NEAR SUNRISE FRIDAY.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE WILL REMAIN TO THE NORTH OF THE FORECAST
WATERS THROUGH FRIDAY. A TIGHTENING GRADIENT OVER THE EASTERN GULF
AROUND THIS RIDGE WILL LEAD TO PERIODS OF CAUTIONARY LEVEL
WINDS...ESPECIALLY OFFSHORE. FRIDAY NIGHT AND SATURDAY...AN EVEN
STRONG RIDGE OF HIGH PRESSURE WILL BUILD DOWN THE EASTERN ATLANTIC
SEABOARD RESULTING IN WIDESPREAD CAUTIONARY TO POTENTIAL LOW END
ADVISORY LEVEL WINDS FOR THE EASTERN GULF OF MEXICO.
&&
.FIRE WEATHER...
A DRY BUT SEASONABLE AIRMASS WILL REMAIN IN PLACE THE NEXT COUPLE OF
DAYS. FRIDAY SHOULD BE THE DRIEST DAY OF THE SHORT TERM WHEN MANY
INLAND LOCATIONS SEE RELATIVE HUMIDITY VALUES DROP INTO THE UPPER
30S AND LOWER 40S DURING THE AFTERNOON. CURRENT FORECAST DOES NOT
SUPPORT ANY CRITICAL LEVELS OF RELATIVE HUMIDITY AND ERC VALUES
REMAIN QUITE LOW. A SLOW INCREASE IN LOW LEVEL MOISTURE OFF THE
ATLANTIC SHOULD PREVENT CRITICAL LEVELS OF RELATIVE HUMIDITY FROM
BEING REACHED DURING THE UPCOMING WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 68 86 68 87 / 0 0 0 0
FMY 68 88 68 88 / 0 0 0 10
GIF 64 87 66 89 / 0 0 0 0
SRQ 67 87 67 88 / 0 0 0 10
BKV 60 87 61 87 / 0 0 0 0
SPG 72 85 73 86 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION...JILLSON
LONG TERM...RUDE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
105 PM CDT THU OCT 11 2012
.SHORT TERM...
ISSUED AT 311 AM CDT THU OCT 11 2012
(TODAY THROUGH FRIDAY NIGHT)
WARM ADVECTION UNDER WAY OVER SOUTHWEST MISSOURI AT THIS TIME.
CLOUD DECK BETWEEN 5000-8000FT IS MOVING SLOWLY NORTHEAST TOWARD OUR
AREA. CLOUDS SHOULD OVERSPREAD CENTRAL MISSOURI BY LATE MORNING AND
ON INTO EASTERN MISSOURI EARLY IN THE AFTERNOON. EVEN THOUGH PRECIP
HAS YET TO DEVELOP...SHORT-RANGE MODELS CONTINUE TO PRINT OUT PRECIP
DUE TO THE STRONG WARM ADVECTION AND MOISTURE CONVERGENCE ON THE
850MB BAROCLINIC ZONE ACROSS SOUTHERN MISSOURI. FORECAST SOUNDINGS
ARE PRETTY STRONGLY CAPPED THOUGH SO WOULD EXPECT THAT PRECIP WILL
BE PRETTY SCATTERED. HRRR DEVELOPS ISOLATED TO WIDELY SCATTERED
PRECIP...SO THIS JIVES WELL WITH THAT THINKING. WARM ADVECTION WILL
CONTINUE TONIGHT OVER SOUTHERN MISSOURI AND A SUBTLE SHORTWAVE WILL
BRING ANOTHER CANADIAN HIGH AND A SHOT OF COOL AIR DOWN FROM THE
NORTHERN PLAINS INTO MISSOURI TO REINFORCE THE BAROCLINIC ZONE. THE
STRONG BAROCLINICITY AND CONTINUING LOW LEVEL JET COMBINED WITH THE
SHORTWAVE PASSING OVERHEAD SHOULD PRODUCE MORE WIDESPREAD RAIN AND
THUNDERSTORMS. THE LOW LEVEL JET AND MOISTURE CONVERGENCE STAYS
FOCUSED OVER SOUTHERN MISSOURI...SO HAVE BACKED DOWN TO CHANCE POPS
ALONG THE I-70 CORRIDOR TONIGHT BUT KEPT LIKELY DOWN OVER THE
OZARKS. LOW LEVEL JET CHANGES FOCUS TO THE GREAT PLAINS ON FRIDAY
WHICH SHOULD BRING THE RAIN OVER SOUTHEAST MISSOURI TO AN END. THE
AFOREMENTIONED CANADIAN HIGH MOVES OVER THE MID ATLANTIC FRIDAY
NIGHT WHICH TURNS LOW LEVEL FLOW TO THE SOUTH. THIS PUSHES A WARM
FRONT UP THROUGH OUR AREA INTO THE UPPER MIDWEST SETTING THE STAGE
FOR A WARM SATURDAY AND POTENTIALLY SEVERE WEATHER SATURDAY NIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 340 AM CDT THU OCT 11 2012(SATURDAY THROUGH WEDNESDAY)
WE SHOULD BE WELL INTO THE WARM SECTOR ON SATURDAY. NAM AND GFS
SHOW 14-16C AT 850MB SATURDAY AFTERNOON SO AM GOING AT OR ABOVE
UPPER RANGE OF GUIDANCE TEMPS. THE SYNOPTIC SETUP REMAINS
FAVORABLE FOR SEVERE WEATHER SATURDAY AFTERNOON AND NIGHT. THE
DETAILS IN THE MODELS ARE VERY SIMILAR AND HAVE BEEN VERY
CONSISTENT. DEEP LAYER SHEAR IN EXCESS OF 50KTS WITH A STRONG
SHORTWAVE AND LOW LEVEL MOISTURE WILL BE IN PLACE. CONVECTION LOOKS
TO DEVELOP OVER EASTERN KANSAS AND SHOULD MOVE INTO MISSOURI DURING
THE LATE AFTERNOON. FOR OUR AREA...BEST CHANCE FOR STORMS WILL BE
SATURDAY NIGHT. DAY 3 SEVERE OUTLOOK COVERS ALL OF CENTRAL AND
NORTHEAST MISSOURI AS WELL AS PARTS OF THE STL METRO. STILL...MODE
AND SEVERITY OF CONVECTION WILL LIKELY BE DECIDED BY AMOUNT OF
AVAILABLE INSTABILITY. STAY TUNED.
COLD FRONT ASSOCIATED WITH THE STORM WILL MOVE THROUGH SUNDAY
MORNING. COULD SEE SOME LINGERING SHOWERS AHEAD OF THE FRONT...BUT
IT LOOKS LIKE DRY AIR WILL SHUT THE PRECIP OFF SO WILL KEEP POPS OUT
OF THE FORECAST EXCEPT FOR EXTREME EASTERN ZONES FOR NOW. TEMPS
WILL COOL FROM SATURDAY`S HIGHS...BUT THE REALLY COLD AIR WILL STAY
LOCKED UP IN CANADA THIS TIME AS AN UPPER LEVEL RIDGE BUILDS ACROSS
THE WESTERN HALF OF THE U.S. WARM AND DRY CONDITIONS WILL CONTINUE
MONDAY AND TUESDAY UNDER THE INFLUENCE OF THE RIDGE. TEMPS SHOULD
BE AT OR ABOVE NORMAL IN THE 70S. NEXT CHANCE FOR RAIN WILL COME
WEDNESDAY AS ANOTHER SHORTWAVE DIPS INTO THE UPPER MIDWEST WHICH
WILL ALLOW THE LOW LEVEL JET TO RAMP UP OVER THE AREA AHEAD OF A
COLD FRONT.
CARNEY
&&
.AVIATION...
ISSUED AT 1251 PM CDT THU OCT 11 2012
A STRATUS DECK WILL CONTINUE TO EXPAND NORTHEASTWARD THROUGH THIS
AFTERNOON...WITH CIGS EXPECTED TO REMAIN VFR FOR METRO TAF SITES
AND KUIN. HOWEVER...KCOU COULD BOUNCE BETWEEN HIGH END MVFR TO
LOW VFR AS THE THICKER CLOUDCOVER EXPANDS OVER CENTRAL
MISSOURI...WHERE DIURNAL EFFECTS CANNOT EFFECTIVELY ASSIST IN
KEEPING CLOUD BASES MORE ELEVATED. ALONG AND SOUTH OF I-70...CIGS
ARE EXPECTED TO LOWER TO MVFR BY TONIGHT. WINDS WILL REMAIN
SOUTHERLY THROUGH TONIGHT WHEN A COLD FRONT SLIDES SOUTHWARD
ACROSS THE REGION. EXPECT FROPA THROUGH KUIN AOA 03Z...KCOU AOA
04Z...AND METRO TAF SITES A0A 06Z WITH WINDS VEERING TO THE
NORTHWEST. THOUGH THERE IS A CHANCE FOR SOME PRECIPITATION THIS
EVENING MAINLY ALONG AND SOUTH OF I-70...COVERAGE IS EXPECTED TO
BE WIDELY SCATTERED...AND THUS CONFIDENCE IS TOO LOW TO INCLUDE
MENTION IN THE TAFS AT THIS TIME.
SPECIFICS FOR KSTL...
VFR CONDITIONS WITH CLOUDY SKIES THROUGH THIS EVENING WHEN CIGS
ARE EXPECTED TO DROP TO MVFR AROUND 06Z. THERE IS A CHANCE FOR
PRECIPITATION THIS EVENING...THOUGH COVERAGE WILL BE WIDELY
SCATTERED AND THUS HAVE NOT INCLUDED MENTION IN THE TAF. WINDS
WILL VEER TO THE NORTHWEST BEHIND A COLD FRONT TONIGHT AROUND
06Z...THOUGH CIGS ARE EXPECTED TO REMAIN HIGH-END MVFR THROUGH THE
REMAINDER OF THE VALID FORECAST PERIOD.
JP
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 47 66 57 / 10 30 10 10
QUINCY 66 39 61 54 / 10 10 5 60
COLUMBIA 64 44 65 57 / 10 50 20 20
JEFFERSON CITY 63 46 65 58 / 20 60 20 20
SALEM 62 46 64 51 / 10 30 10 10
FARMINGTON 58 48 64 55 / 20 70 20 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
309 PM CDT THU OCT 11 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT...
THE HIGHLIGHT OF THE SHORT TERM IS THE POTENTIAL FOR CRITICAL FIRE
WEATHER CONDITIONS ON FRIDAY.
FOR TONIGHT...SURFACE HIGH PRESSURE WILL QUICKLY PROPAGATE ACROSS
WESTERN AND CENTRAL NORTH DAKOTA. SOUTHEASTERLY RETURN FLOW WILL
COMMENCE BY 5-6 UTC AND STRENGTHEN THROUGH THE NIGHT...SLOWING THE
TEMPERATURE FALL ONLY INTO THE UPPER 20S TO THE LOWER 30S.
FOR FRIDAY...STRONG SOUTHERLY FLOW IS FORECAST AHEAD OF A WARM
FRONT THAT WILL PROPAGATE INTO FAR WESTERN NORTH DAKOTA BY THE LATE
AFTERNOON. BORDERLINE WIND ADVISORY CRITERIA IS POSSIBLE FOR THE
CENTRAL WITH GUSTS TO 35 KTS WITH ISALLOBARIC FORCING FROM
PRESSURE FALLS ON THE ORDER OF 9 MB/ 6 HR ENHANCING THE GRADIENT
FLOW AND MIXING. LOWER MIXING HEIGHTS AHEAD OF THE WARM FRONT WILL
LIMIT HIGH TEMPERATURES ACROSS CENTRAL NORTH DAKOTA INTO THE 55-60
DEGREE RANGE. HOWEVER...HIGHS IN THE MID TO UPPER 60S ARE POSSIBLE
ACROSS THE FAR WEST BEHIND THE WARM FRONT AS WINDS TRANSITION TO
THE SOUTHWEST. GIVEN THE AFOREMENTIONED CONDITIONS...CRITICAL FIRE
WEATHER CONDITIONS MAY BE POSSIBLE ACROSS PORTIONS OF CENTRAL
NORTH DAKOTA ON FRIDAY AND ISSUED A FIRE WEATHER WATCH. SEE THE
FIRE WEATHER DISCUSSION BELOW FOR DETAILS.
.LONG TERM...SATURDAY THROUGH THURSDAY...
THE START OF THE LONG TERM PERIOD WILL FEATURE AN H5 WAVE MOVING
FROM THE CENTRAL PLAINS INTO THE UPPER GREAT LAKES. PRECIPITATION
FROM THIS SYSTEM COULD STILL TRY TO CLIP THE FAR SOUTHEAST PART OF
THE FORECAST AREA...BUT OVERALL IT APPEARS THE BULK OF FORECAST
AREA WILL REMAIN DRY AS IT PASSES.
A SERIES OF WAVES WILL MOVE ACROSS THE NORTHERN PLAINS/SOUTHERN
CANADA FROM SUNDAY INTO THE MIDDLE OF NEXT WEEK. THE ALL BLEND
MODEL SOLUTION HOLDS ONTO SMALL CHANCES OF RAIN IN THE EXTREME
NORTHERN PORTION OF THE FORECAST AREA ON SUNDAY...THOUGH ITS
ENTIRELY POSSIBLE THE MAIN CHANCES COULD STAY JUST NORTH OF THE
BORDER IN CANADA.
A WAVE FOR MONDAY NIGHT APPEARS TO BRING RAIN CHANCES TO A LARGER
PORTION OF THE FORECAST AREA...BUT ALL BLEND POPS REMAIN ONLY IN THE
SLIGHT CHANCE CATEGORY. A BETTER CHANCE OF RAIN APPEARS TO ARRIVE
TUESDAY INTO WEDNESDAY AS THE LEFT FRONT QUADRANT OF THE UPPER JET
SHIFTS ACROSS NORTH DAKOTA IN ASSOCIATION WITH A STRONGER H5 WAVE.
THIS WAVE ALSO HELPS USHER A COLD FRONT THROUGH THE FORECAST AREA
WITH GUSTY NORTHWEST WINDS EXPECTED BEHIND THE BOUNDARY. H85
TEMPERATURES APPROACH OR FALL JUST BELOW FREEZING ON WEDNESDAY...BUT
LOW LEVEL TEMPERATURES STILL APPEAR TOO WARM FOR SNOW.
&&
.AVIATION...
ISOLATED MVFR CEILINGS REMAIN ACROSS PARTS OF WESTERN
NORTH DAKOTA...BUT NOW THAT THE TERMINAL LOCATIONS HAVE GONE BACK TO
VFR...WILL LEAVE THEM THERE FOR THE AFTERNOON. RAP BUFR SOUNDINGS
SUGGEST VFR CEILINGS AROUND 4KFT COULD PERSIST FOR MUCH OF THE
AFTERNOON...BUT THOSE ARE EXPECTED TO CLEAR THIS EVENING. WINDS
WILL CONTINUE TO BECOME LIGHT THIS AFTERNOON / EVENING AS SURFACE
HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS. WINDS WILL BECOME
SOUTHERLY LATER THIS EVENING AS THE HIGH SLIDES EAST INTO
MINNESOTA. A TIGHT PRESSURE GRADIENT ON FRIDAY COMBINED WITH
SUFFICIENT MIXING WILL ALLOW WIND SPEEDS TO INCREASE AND BECOME
GUSTY SHORTLY AFTER SUNRISE.
&&
.FIRE WEATHER...
ISSUED A FIRE WEATHER WATCH FOR SOUTH CENTRAL NORTH DAKOTA AND THE
JAMES RIVER VALLEY FOR FRIDAY. STRONG SOUTHERLY WINDS IN EXCESS
OF 30 MPH ARE FORECAST TO DEVELOP ACROSS SOUTH CENTRAL NORTH
DAKOTA AND THE JAMES RIVER VALLEY LATE FRIDAY MORNING THROUGH
EARLY EVENING. AFTERNOON HIGH TEMPERATURES OF 55 TO 60 ARE
EXPECTED...WITH RELATIVE HUMIDITY VALUES FALLING TO NEAR 25
PERCENT. WHEN COMBINED WITH ABUNDANT DRY FUELS...VERY HIGH FIRE
DANGER AND RAPID FIRE GROWTH ARE POSSIBLE FRIDAY. WHILE STRONG
WINDS ARE FORECAST ACROSS THE NORTH CENTRAL...HIGHER RELATIVE
HUMIDITY VALUES WILL LIMIT THE FIRE DANGER.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING
FOR NDZ020-022-023-025-034>037-042-045>048-050-051.
&&
$$
SHORT TERM/FIRE...AYD
LONG TERM/AVIATION...CK
AREA FORECAST DISCUSSION
NWS TULSA OK
1232 PM CDT THU OCT 11 2012
.DISCUSSION...
THE 18Z TAF DISCUSSION CAN BE FOUND BELOW.
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
MVFR CIGS SHOULD INCREASE TO VFR LATER THIS AFTERNOON. LATER ON
TONIGHT...MAINLY AFT 04Z...SCT TSRA ARE EXPTD TO DVLP OVER NE OK
AND NW AR. THE ACTIVITY WILL GRADUALLY BUILD SOUTH AND MAY AFFECT
KFSM AND/OR KMLC TOWARD THE END OF THE TAF PERIOD. MVFR CONDITIONS
ARE LIKELY WITH THIS STORM ACTIVITY.
LACY
&&
.PREV DISCUSSION... /ISSUED 1044 AM CDT THU OCT 11 2012/
DISCUSSION...
LOW LVL MOISTURE RETURN ON THE BACK SIDE OF THE SURFACE HIGH OVER
THE SOUTHEAST STATES HAS RESULTED IN WIDESPREAD LOW CLOUDS. THE
LATEST DATA INDICATES THAT THIS CLOUD COVER WILL STICK AROUND FOR
MUCH OF THE DAY...LIMITING HEATING. I HAVE LOWERED HIGHS TEMPS BY
A CATEGORY IN MOST PLACES. THE LATEST HRRR SUGGESTS THAT THE
MORNING SHOWERS AND ISOLD TSTORMS TO THE SOUTH AND EAST OF TULSA
WILL EVENTUALLY DISSIPATE THIS AFTERNOON AND SHOULD REMAIN QUIET
UNTIL TONIGHT. THUS I HAVE MADE SOME ADJUSTMENT TO THE
POPS...DECREASING THEM IN THE WEST. TEXT PRODUCTS HAVE BEEN SENT.
LACY
PREV DISCUSSION... /ISSUED 556 AM CDT THU OCT 11 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
WIDESPREAD MVFR CIGS SHOULD PERSIST THROUGH THE MORNING
HOURS...ALONG WITH WIDELY SCATTERED SHOWERS MAINLY FOR
THE ARKANSAS TAF SITES. EXPECT CIGS TO RISE TO VFR AFTER
18-20Z. THUNDERSTORM DEVELOPMENT LIKELY AT KBVO/KTUL/KRVS
KFYV AND KXNA AROUND 04-06Z...WITH SEVERE THUNDERSTORMS
POSSIBLE.
PREV DISCUSSION... /ISSUED 323 AM CDT THU OCT 11 2012/
DISCUSSION...
FRONTAL BOUNDARY...CURRENTLY LOCATED ACROSS FAR SOUTHERN ARKANSAS
THIS MORNING...HAS BEGUN TO LIFT BACK NORTH INTO SOUTHEAST
OKLAHOMA THIS MORNING WITH LOW LEVEL MOISTURE INCREASING. ISOLATED
SHOWERS/THUNDERSTORMS MAY DEVELOP LATER THIS MORNING AS THE LOW
LEVEL JET CONTINUES TO INCREASE WITH A LIMITED SEVERE THREAT ALONG
AND NORTH OF THE RETREATING WARM FRONT.
BETTER THUNDERSTORM CHANCES...INCLUDING THE THREAT FOR SEVERE
WEATHER...WILL OCCUR THIS EVENING INTO THE OVERNIGHT HOURS AS A
SECONDARY SURGE OF COOLER AIR MOVES TO THE OKLAHOMA/KANSAS BORDER
AND STALLS. MOISTURE POOLING ALONG THE FRONT WILL ALLOW THE
ATMOSPHERE TO BECOME MODERATELY UNSTABLE WITH 30-40 KNOT DEEP
LAYER SHEAR IN PLACE. LARGE HAIL WILL BE THE PRIMARY THREAT WITH
THE STRONGER STORMS OVERNIGHT...INCLUDING THE THREAT FOR LOCALLY
HEAVY RAINFALL.
MAIN FOCUS THEN SHIFTS TO STRONG UPPER LOW CURRENTLY OFF THE
CALIFORNIA COAST AND ITS POTENTIAL IMPACTS INTO THE WEEKEND. UPPER
LOW WILL QUICKLY LIFT NORTHEAST INTO THE CENTRAL PLAINS BY
SATURDAY. STRONG TO SEVERE THUNDERSTORMS WILL BE LIKELY SATURDAY
AFTERNOON INTO SATURDAY EVENING AS THE COLD FRONT SWEEPS EAST
THROUGH THE AREA. STRONG LOW LEVEL WIND FIELDS WILL DEVELOP AHEAD
OF FRONT AND WITH MODERATE INSTABILITY EXPECTED...ALL MODES OF
SEVERE WEATHER WILL BE POSSIBLE. THE SEVERE THREAT SHOULD END
SUNDAY MORNING AS CONVECTIVE LINE SWEEPS EAST.
FOR THE REMAINDER OF THE FORECAST...WARM/DRY CONDITIONS ARE
GENERALLY EXPECTED. ANOTHER COLD FRONT IS EXPECTED AROUND MID
WEEK...HOWEVER AS IT APPEARS NOW...LIMITED MOISTURE WILL KEEP
PRECIPITATION CHANCES LOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 68 82 66 80 / 80 60 20 80
FSM 65 81 63 82 / 50 30 10 30
MLC 66 83 66 82 / 30 20 10 50
BVO 60 78 63 81 / 80 60 40 80
FYV 60 78 61 82 / 80 60 10 40
BYV 58 74 61 82 / 80 60 10 30
MKO 65 81 64 80 / 60 30 10 50
MIO 61 78 63 81 / 80 60 20 70
F10 66 81 66 81 / 50 30 20 70
HHW 66 84 64 82 / 20 20 10 40
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1220 PM CDT THU OCT 11 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...ISOLATED SHOWERS ARE EXPECTED...MAINLY ALONG AND WEST
OF HIGHWAY 77 THROUGH THE REMAINDER OF THE AFTERNOON. THUNDERSTORM
DEVELOPMENT IS POSSIBLE...MAINLY FROM MFE NORTHWARD TO ABOUT HBV
OR BKS THROUGH MID AFTERNOON. BRIEF MVFR VISBY AND GUSTY WINDS CAN
BE EXPECTED AT AIRFIELDS THAT HAPPEN TO CATCH A THUNDERSTORM THIS
AFTERNOON. SOUTHEAST WINDS...GUSTING AT 20 TO 25 KNOTS ARE
EXPECTED THROUGH LATE AFTERNOON AT ALL SITES.
TONIGHT WINDS SHOULD SUBSIDE TO 6 TO 8 KNOTS...BUT AN MVFR CIG AT
AROUND 2000 TO 2500 FT MAY SET UP BY AROUND 09Z THROUGH MOST OF
THE REGION...LASTING THROUGH SUNRISE. LOWEST CIGS ARE EXPECTED AT BKS
AND HBV. THAT CEILING SHOULD GRADUALLY LIFT THROUGH EARLY MORNING
AND ANOTHER ROUND OF GUSTY SOUTH TO SOUTHEAST WINDS IS ANTICIPATED
STARTING AT AROUND 15Z. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 1006 AM CDT THU OCT 11 2012/
DISCUSSION...UPDATED NEAR TERM POP GRIDS BASED ON LATEST
OBSERVATIONAL TRENDS. SHOWERS SOUTH OF HIDALGO AND CAMERON COUNTY
ARE LIFTING FROM AROUND 950MB...AND WILL LIKELY PERSIST FOR
ANOTHER HOUR OR TWO BEFORE DIMINISHING. CU STREAKS ALONG THE
IMMEDIATE COASTAL REGION ON VISIBLE SATELLITE POINT TO SEABREEZE
CONVERGENCE FORMING UP ON SCHEDULE THIS MORNING. MODIFIED OBSERVED
AND LAPS SOUNDINGS SHOW WE WILL ONLY NEED ABOUT 2000FT OF
MECHANICAL LIFTING TO GET CONVECTION TODAY WITH SLIGHTLY COOLER
TEMPERATURES AT 850 TO 925MB THAN YESTERDAY WITH JUST SLIGHTLY
BETTER MOISTURE. ANY SURFACE BASED PARCELS THAT MAKE IT TO
THUNDERSTORM STATUS WILL HAVE ABOUT 3000 J/KG OF CAPE WITH A THETA
E DIFFERENTIAL OF AROUND 35 K...SO GUSTY WINDS WILL BE POSSIBLE.
WITH A COLUMN PWAT AROUND 1.80 STORMS WILL ALSO BE EFFICIENT
RAINFALL PRODUCERS. WITH THE STRONGER SOUTHEAST WINDS TODAY STILL
EXPECT THAT WILL BE ISOLATED AT BEST FOR NOW. 14Z RAP...WHICH
SEEMS TO HAVE A GOOD HANDLE...09Z SREF AND 12Z HRRR USED
PARTIALLY TO ASSIST WITH LOCATION OF BEST RAINFALL CHANCES AND
TIMING. NEAR TERM DEWPOINTS AND SKY ALSO TWEAKED...BUT PACAKGE IS
IN GOOD SHAPE OVERALL. /68-JGG/
PREV DISCUSSION... /ISSUED 623 AM CDT THU OCT 11 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...STREAMER SHOWERS ARE ATTEMPTING TO MOVE INLAND NEAR THE
COAST THIS MORNING. EXPECT REMNANTS OF THESE SHOWERS TO PASS NEAR
IMMEDIATELY COASTAL AIRPORTS DURING THE NEXT COUPLE HOURS...WITH
TEMPO CIG REDUCTIONS TO AROUND 2000 FEET. SCT TO BKN CLOUDS AT
AROUND 3500 FT ARE EXPECTED BY MID TO LATE MORNING WITH SCATTERED
SHOWERS AND POSSIBLY A THUNDERSTORM DEVELOPING ALONG THE SEABREEZE
AND MOVING WEST. WINDS WILL JUMP TO 15G25KTS LATER THIS AFTERNOON
BEFORE REDUCING BACK TO AROUND 5KTS OVERNIGHT.
PREV DISCUSSION... /ISSUED 426 AM CDT THU OCT 11 2012/
SHORT TERM /TODAY THROUGH FRIDAY/...MIDLEVEL RIDGE SLOWLY
BUILDING ALOFT OVERHEAD DURING THE NEXT 36 HOURS. THIS WILL BE
COUNTERACTED BY SOUTHEAST FLOW AT THE SFC CONTINUING TO INCREASE
LLVL MOISTURE. PW VALUES ABOVE 1.8 INCHES AND TEMPERATURES IN THE
90S AREAWIDE WILL ALLOW THE SEABREEZE TO FORM AND DRIFT NEWD
ACROSS THE REGION TODAY. WINDS OF 15 TO 20KTS WILL MAKE THE
SEABREEZE A MORE DIFFUSE BOUNDARY...BUT SHOWERS WILL BE ABLE TO
POP UP THIS AFTERNOON...ALSO AIDED BY INSTABILITY FROM STREAMER
SHOWERS CURRENTLY ATTEMPTING TO MOVE ASHORE FROM THE SOUTHEAST.
TEMPERATURES WILL BE NEAR YESTERDAY/S HIGHS...IMPEDED SLIGHTLY BY
INCREASED MOISTURE. OF NOTE WERE YESTERDAY/S TEMPERATURES IN MFE
/96/ AND EBG /98/ WERE HIGHER THAN DEATH VALLEY CALIFORNIA /95/.
ANOTHER HOT AND HUMID DAY TOMORROW WITH ANOTHER ROUND OF SEABREEZE
SHOWERS.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY...EXTENDED DOES NOT
VARY MUCH FROM YESTERDAY WITH EXCEPTION TO THE ADDITION OF SLIGHT
CHANCE OF RAIN ACROSS THE NORTHERN TIER COUNTIES MONDAY AS A
WEAKENING COLD FRONT APPROACHES. OTHERWISE...HIGH PRESSURE TO
DOMINATE THROUGH THE COMING WEEKEND WITH HOT AND DRY WEATHER THEN
THE RIDGE BREAKS DOWN AS A BROAD LOW PRESSURE TROUGH DEVELOPS
ACROSS THE EASTERN TWO THIRDS OF THE COUNTRY.
FORECAST TRENDS WITH THE GFS WITH ENSEMBLE MEMBERS SHOWING A
NARROW VARIANCE THROUGH THE NEXT 7 DAYS. THE FIRST THREE DAYS GFS
AND ECMWF SHOW GOOD CONSISTENCY THROUGH THE WEEKEND BEFORE SOME
MID LEVEL PATTERN DIFFERENCES START DEVELOPING IN BY THE END OF
THE FORECAST PACKAGE.
MAIN FEATURES WE ARE KEEPING AN EYE ON ARE AN UPPER LOW OFF THE
CALIFORNIA COAST AND A STRONG MID LEVEL RIDGE PARKED OVER THE
WESTERN GULF. SURFACE PRESSURE TO LOWER ACROSS THE SOUTHERN PLAINS
FRIDAY NIGHT THROUGH SATURDAY WITH A LOW LEVEL JET GAINING
STRENGTH. THIS WILL GENERATE WINDY CONDITIONS SATURDAY WITH GUSTS
UPWARDS OF 35 MPH. DO NOT THINK GRADIENT WILL BE STRONG ENOUGH FOR
A WIND ADVISORY WITH SURFACE HIGH OVER THE GULF NOT AS STRONG AS
WOULD LIKE TO SEE. THE SOUTHERLY FLOW PUMPS IN SOME MOISTURE
ACROSS THE REGION WITH TEMPERATURE PICKING RISING WELL ABOVE
NORMAL. THE MID LEVEL LOW LIFTS QUICKLY NORTHEAST DRAGGING A
PACIFIC FRONT ACROSS THE STATE. GFS AND ECMWF PLACE WITH FRONT
NEAR THE NORTHERN COUNTIES SUNDAY WHICH MIGHT BE CLOSE ENOUGH TO
WARRANT A FEW SHOWERS OR THUNDERSTORMS. GFS IS MUCH HIGHER ON THE
POPS THEN ECMWF SO A LOW BIAS ON RAIN CHANCES WERE ADDED ACROSS
THE NORTH. DOWN SOUTH MUCH OF THE SAME FOR NOW.
LITTLE CHANGE MADE TO THE LATTER HALF OF THE FORECAST WITH A
PERSISTENT WEAK MIDLEVEL NORTHWEST FLOW. AS MENTIONED ABOVE
FORECAST TRENDS TOWARDS THE GFS WITH ABOVE NORMAL TEMPERATURES AND
KEEPING ANY FRONTS WELL NORTH OF THE REGION UNTIL MAYBE THURSDAY OR
FRIDAY. EUROPEAN MODELS IS MORE AGGRESSIVE WITH THE TROUGH OVER THE
CENTRAL PLAINS AND IS MORE AGGRESSIVE WITH A FRONT THROUGH THE
AREA WEDNESDAY. WILL DETER FROM THIS SOLUTION FROM NOW UNTIL
BETTER MODEL CONSISTENCY IS SEEN.
MARINE...TODAY THROUGH FRIDAY...WINDS ACROSS THE GULF WATERS WILL
INCREASE TO 15 TO 20 KNOTS TODAY...WITH SEAS FLUCTUATING BETWEEN 3
AND 5 FEET THIS AFTERNOON. THESE CONDITIONS ARE FORECAST TO CONTINUE
THROUGH THURSDAY NIGHT INTO FRIDAY. ADVISORIES ARE NOT CURRENTLY
FORECAST...BUT SMALL CRAFT SHOULD EXERCISE CAUTION.
FRIDAY NIGHT THROUGH MONDAY...SMALL CRAFT ADVISORY ARE BECOMING
MORE PROBABLE FRIDAY NIGHT THROUGH SATURDAY AS THE PRESSURE
GRADIENT STRENGTHENS AS SURFACE PRESSURES LOWER SIGNIFICANTLY OVER
NORTHWEST TEXAS IN RESPONSE TO AN UPPER LOW MOVING THROUGH THE
SOUTHERN ROCKIES. STRONG WIND AND BUILD WIND WAVES ARE IN ORDER
THROUGH SATURDAY NIGHT. WINDS AND SEAS BEGIN TO RELAX SUNDAY AND
BECOME LOWER MONDAY AS THE LOW LIFTS OUT AND A WEAK FRONT STALLS
JUST NORTH OF THE REGION.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/66
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT THU OCT 11 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
345 PM CDT THU OCT 11 2012
AT 3 PM...RADAR CONTINUES TO SHOW A BAND OF RAIN SHOWERS ACROSS
SOUTH CENTRAL AND SOUTHEAST MINNESOTA...NORTHERN IOWA...AND
SOUTHERN WISCONSIN. THERE WAS EVEN A REPORT OF A MIX OF RAIN AND
SLEET 7 MILES WEST OF CRESCO IN HOWARD COUNTY. THE KARX
CORRELATION COEFFICIENTS SHOW VALUES AS LOW 0.8 COLLOCATED WITH
THE HIGHEST REFLECTIVITIES...SO WOULD NOT BE SURPRISED THAT THERE
WILL BE OTHER REPORTS THIS AFTERNOON. THIS PRECIPITATION IS
ASSOCIATED WITH MODERATE TO STRONG 900-700 MB FRONTOGENESIS. THE
LATEST RAP CONTINUES TO SHOW THAT THIS FORCING WILL CONTINUE
TO MOVE SOUTH THIS AFTERNOON...AND BY 11.00Z IT SHOULD BE LOCATED
JUST SOUTH OF THE FORECAST AREA.
LIKE THE PAST SEVERAL DAYS...THE 11.12Z MODELS CONTINUE TO SHOW
THAT A CANADIAN HIGH PRESSURE SYSTEM WILL BUILD SOUTH INTO THE
UPPER MISSISSIPPI RIVER VALLEY TONIGHT...AND THEN MOVE QUICKLY
EAST THROUGH THE OHIO RIVER VALLEY AND INTO THE MID ATLANTIC ON
FRIDAY. WITH LIGHT WINDS...MAINLY CLEAR SKIES...AND LIGHT WINDS
OVERNIGHT...TEMPERATURES WILL FALL INTO THE 20S IN MOST LOCATIONS.
THERE MAY BE EVEN A FEW TEENS IN CENTRAL AND NORTH CENTRAL
WISCONSIN.
ON FRIDAY NIGHT...A SHORT WAVE TROUGH WILL EJECT OUT AHEAD OF A
CLOSED LOW PRESSURE SYSTEM OVER COLORADO. MODERATE TO STRONG
ISENTROPIC LIFT WILL DEVELOP AHEAD OF THIS WAVE. IN
ADDITION...THERE WILL BE STRONG 925 AND 850 MB MOISTURE TRANSPORT
INTO THE REGION. THE NAM QUICKLY GENERATES PRECIPITATION ON FRIDAY
EVENING. MEANWHILE THE OTHER MODELS SUGGEST THAT THE PRECIPITATION
WILL NOT DEVELOP UNTIL AFTER MIDNIGHT FRIDAY NIGHT. LOOKING AT THE
BUFKIT MODEL SOUNDINGS THERE IS VERY LITTLE DIFFERENCE BETWEEN THE
GFS AND NAM. BOTH MODELS SHOW THAT DURING THE EVENING THE AIR MASS
WILL MOISTEN RAPIDLY BETWEEN 800 AND 600 MB AND THERE IS SOME
MODERATE OMEGA IN THIS SAME LAYER. DESPITE THE NAM/WRF APPEARING
AS AN OUTLIER DECIDED THAT IT HAD A MUCH BETTER HANDLE OF THE
DEVELOPMENT OF INITIAL SHOWERS THAN THE OTHER MODELS. AFTER
MIDNIGHT...THE 0-3 KM MOST UNSTABLE CAPES CLIMB UP TO 1000 J/KG
MAINLY SOUTH OF THE INTERSTATE 94 CORRIDOR. AS A RESULT...WENT
WITH THE BEST CHANCES FOR THUNDERSTORMS IN THIS AREA. WITH 1-7 KM
SHEAR LESS THAN 25 KNOTS...NOT ANTICIPATING ANY OF THESE
THUNDERSTORMS TO BECOME SEVERE.
ON SATURDAY MORNING...THERE ARE SOME MODELS SUGGEST THAT THE BEST
MOISTURE TRANSPORT WILL MOVE EAST OF THE AREA BY LATE MORNING. AS
A RESULT STILL THINKING THAT THERE WILL BE A POSSIBILITY OF A
BREAK IN THE SHOWERS AND THUNDERSTORMS LATE SATURDAY MORNING AND
EARLY AFTERNOON. THE MAIN QUESTION FOR THE AFTERNOON WILL THERE BE
SOME CLEARING IN THE WARM SECTOR OF THIS SYSTEM TO HELP INCREASE
THE MEAN LAYER CAPES ALONG AND SOUTH OF THE INTERSTATE 90
CORRIDOR. BOTH THE GFS AND NAM CONTINUE TO HINT THAT THIS WILL
MORE LIKELY OCCUR ACROSS EASTERN IOWA...ILLINOIS...AND THE
SOUTHERN QUARTER OF WISCONSIN. HOWEVER THE 10.09Z SUGGEST THAT THE
MLCAPE WILL BE GREATER THAN 500 J/KG...THE 0-1 KM HELICITY WILL BE
GREATER THAN 100...AND BOTH THE 0-3 KM AND 0-6 KM SHEAR WILL BE
FAVORABLE FOR THE POSSIBILITY OF SEVERE WEATHER ALONG THE COLD
FRONT LATE SATURDAY AFTERNOON AND EVENING ALONG AND SOUTH OF THE
INTERSTATE 90 CORRIDOR.
.LONG TERM...SUNDAY THROUGH THURSDAY
345 PM CDT THU OCT 11 2012
ON SUNDAY MORNING...THE MODELS CONTINUE TO SHOW THAT THE
DEFORMATION BAND ON THE BACK SIDE OF THE LOW PRESSURE SYSTEM WILL
STILL LINGER ACROSS MUCH OF THE AREA. AS A RESULT...RAISED THE
PRECIPITATION CHANCES A BIT MORE.
BEYOND THIS TIME PERIOD...THE MODELS CONTINUE TO STRUGGLE ON THE
TIMING OF SYSTEMS AND THE UPPER FLOW. WITH THIS SAID...THERE
CONTINUES TO BE A SIGNAL FOR A STRONG LOW PRESSURE SYSTEM TO
MOVE THROUGH THE REGION ON WEDNESDAY. THIS SYSTEM IS EXPECTED TO
CARVE OUT A BROAD TROUGH ACROSS THE EASTERN CONUS WHICH WILL
RETURN COLDER AIR TO THE REGION.
&&
.AVIATION...
600 PM CDT THU OCT 11 2012
BAND OF -RA ASSOCIATED WITH SOME UPPER LEVEL FRONTOGENETIC FORCING
NORTH OF A WEST-EAST RUNNING SFC COLD FRONT THAT WAS SINKING
SOUTHEAST ACROSS IA/IL. SOME 88-D RADAR RETURNS NEAR KRST/KLSE...BUT
NO GROUND TRUTH VIA OBS. FORCING SHOULD SHIFT SOUTH OF THE TAF SITES
BY 00Z...SO WON/T INCLUDING ANY -RA MENTION.
HIGH PRESSURE BUILDS IN FROM THE NORTHERN PLAINS OVERNIGHT...WITH
THE HIGH OVERHEAD BY 12Z FRI. CLEAR SKIES WITH A LIGHT WIND WILL
RESULT. IT WOULD BE A GREAT SETUP FOR RIVER VALLEY FOG...EXCEPT THE
T/TD SPREAD IS LARGE AND WILL LIKELY REMAIN THAT WAY OVERNIGHT. IN
ADDITION...PROBABLY ADVECTING IN SOME DRIER AIR FROM THE NORTHWEST.
SO...DON/T EXPECT A FG IMPACT AT KLSE FRI MORNING.
THE HIGH WILL EXIT QUICKLY EAST ON FRI...WITH THE WINDS GRADUALLY
SHIFTING TO THE SOUTH AND INCREASING LATER IN THE DAY. CLOUDS WILL
BE ON THE INCREASE FRIDAY NIGHT AS LOW LEVEL THERMODYNAMICS AND
INCREASING SATURATION PUSH IN FROM THE SOUTH/SOUTHWEST...AHEAD OF A
LOW PRESSURE SYSTEM/COLD FRONT APPROACHING FROM THE WEST. AREAS OF
-SHRA WILL LIKELY DEVELOP FROM THE FORCING OVERNIGHT FRI...WITH SAT
LOOKING LIKE A WET DAY. ENOUGH FORCING AND INSTABILITY THAT A FEW
THUNDERSTORMS WILL BE POSSIBLE. EXPECT CIGS TO DROP INTO THE MVFR
RANGE AROUND 12Z SAT OR SHORTLY AFTER...WITH SOME VSBY RESTRICTIONS
IN THE RAIN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
345 PM CDT THU OCT 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 PM CDT THU OCT 11 2012
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
345 PM CDT THU OCT 11 2012
AT 3 PM...RADAR CONTINUES TO SHOW A BAND OF RAIN SHOWERS ACROSS
SOUTH CENTRAL AND SOUTHEAST MINNESOTA...NORTHERN IOWA...AND
SOUTHERN WISCONSIN. THERE WAS EVEN A REPORT OF A MIX OF RAIN AND
SLEET 7 MILES WEST OF CRESCO IN HOWARD COUNTY. THE KARX
CORRELATION COEFFICIENTS SHOW VALUES AS LOW 0.8 COLLOCATED WITH
THE HIGHEST REFLECTIVITIES...SO WOULD NOT BE SURPRISED THAT THERE
WILL BE OTHER REPORTS THIS AFTERNOON. THIS PRECIPITATION IS
ASSOCIATED WITH MODERATE TO STRONG 900-700 MB FRONTOGENESIS. THE
LATEST RAP CONTINUES TO SHOW THAT THIS FORCING WILL CONTINUE
TO MOVE SOUTH THIS AFTERNOON...AND BY 11.00Z IT SHOULD BE LOCATED
JUST SOUTH OF THE FORECAST AREA.
LIKE THE PAST SEVERAL DAYS...THE 11.12Z MODELS CONTINUE TO SHOW
THAT A CANADIAN HIGH PRESSURE SYSTEM WILL BUILD SOUTH INTO THE
UPPER MISSISSIPPI RIVER VALLEY TONIGHT...AND THEN MOVE QUICKLY
EAST THROUGH THE OHIO RIVER VALLEY AND INTO THE MID ATLANTIC ON
FRIDAY. WITH LIGHT WINDS...MAINLY CLEAR SKIES...AND LIGHT WINDS
OVERNIGHT...TEMPERATURES WILL FALL INTO THE 20S IN MOST LOCATIONS.
THERE MAY BE EVEN A FEW TEENS IN CENTRAL AND NORTH CENTRAL
WISCONSIN.
ON FRIDAY NIGHT...A SHORT WAVE TROUGH WILL EJECT OUT AHEAD OF A
CLOSED LOW PRESSURE SYSTEM OVER COLORADO. MODERATE TO STRONG
ISENTROPIC LIFT WILL DEVELOP AHEAD OF THIS WAVE. IN
ADDITION...THERE WILL BE STRONG 925 AND 850 MB MOISTURE TRANSPORT
INTO THE REGION. THE NAM QUICKLY GENERATES PRECIPITATION ON FRIDAY
EVENING. MEANWHILE THE OTHER MODELS SUGGEST THAT THE PRECIPITATION
WILL NOT DEVELOP UNTIL AFTER MIDNIGHT FRIDAY NIGHT. LOOKING AT THE
BUFKIT MODEL SOUNDINGS THERE IS VERY LITTLE DIFFERENCE BETWEEN THE
GFS AND NAM. BOTH MODELS SHOW THAT DURING THE EVENING THE AIR MASS
WILL MOISTEN RAPIDLY BETWEEN 800 AND 600 MB AND THERE IS SOME
MODERATE OMEGA IN THIS SAME LAYER. DESPITE THE NAM/WRF APPEARING
AS AN OUTLIER DECIDED THAT IT HAD A MUCH BETTER HANDLE OF THE
DEVELOPMENT OF INITIAL SHOWERS THAN THE OTHER MODELS. AFTER
MIDNIGHT...THE 0-3 KM MOST UNSTABLE CAPES CLIMB UP TO 1000 J/KG
MAINLY SOUTH OF THE INTERSTATE 94 CORRIDOR. AS A RESULT...WENT
WITH THE BEST CHANCES FOR THUNDERSTORMS IN THIS AREA. WITH 1-7 KM
SHEAR LESS THAN 25 KNOTS...NOT ANTICIPATING ANY OF THESE
THUNDERSTORMS TO BECOME SEVERE.
ON SATURDAY MORNING...THERE ARE SOME MODELS SUGGEST THAT THE BEST
MOISTURE TRANSPORT WILL MOVE EAST OF THE AREA BY LATE MORNING. AS
A RESULT STILL THINKING THAT THERE WILL BE A POSSIBILITY OF A
BREAK IN THE SHOWERS AND THUNDERSTORMS LATE SATURDAY MORNING AND
EARLY AFTERNOON. THE MAIN QUESTION FOR THE AFTERNOON WILL THERE BE
SOME CLEARING IN THE WARM SECTOR OF THIS SYSTEM TO HELP INCREASE
THE MEAN LAYER CAPES ALONG AND SOUTH OF THE INTERSTATE 90
CORRIDOR. BOTH THE GFS AND NAM CONTINUE TO HINT THAT THIS WILL
MORE LIKELY OCCUR ACROSS EASTERN IOWA...ILLINOIS...AND THE
SOUTHERN QUARTER OF WISCONSIN. HOWEVER THE 10.09Z SUGGEST THAT THE
MLCAPE WILL BE GREATER THAN 500 J/KG...THE 0-1 KM HELICITY WILL BE
GREATER THAN 100...AND BOTH THE 0-3 KM AND 0-6 KM SHEAR WILL BE
FAVORABLE FOR THE POSSIBILITY OF SEVERE WEATHER ALONG THE COLD
FRONT LATE SATURDAY AFTERNOON AND EVENING ALONG AND SOUTH OF THE
INTERSTATE 90 CORRIDOR.
.LONG TERM...SUNDAY THROUGH THURSDAY
345 PM CDT THU OCT 11 2012
ON SUNDAY MORNING...THE MODELS CONTINUE TO SHOW THAT THE
DEFORMATION BAND ON THE BACK SIDE OF THE LOW PRESSURE SYSTEM WILL
STILL LINGER ACROSS MUCH OF THE AREA. AS A RESULT...RAISED THE
PRECIPITATION CHANCES A BIT MORE.
BEYOND THIS TIME PERIOD...THE MODELS CONTINUE TO STRUGGLE ON THE
TIMING OF SYSTEMS AND THE UPPER FLOW. WITH THIS SAID...THERE
CONTINUES TO BE A SIGNAL FOR A STRONG LOW PRESSURE SYSTEM TO
MOVE THROUGH THE REGION ON WEDNESDAY. THIS SYSTEM IS EXPECTED TO
CARVE OUT A BROAD TROUGH ACROSS THE EASTERN CONUS WHICH WILL
RETURN COLDER AIR TO THE REGION.
&&
.AVIATION...THROUGH 18Z FRIDAY
1219 PM CDT THU OCT 11 2012
CURRENTLY WATCHING A COLD FRONT EXITING THE AREA ACROSS EASTERN
WI AND IA. ABUNDANT BKN-OVC ALTOCUMULUS WITH BASES MAINLY AOA
10KFT STILL LINGERING OVER THE AREA IN RESPONSE TO MID-LEVEL
ATMOSPHERIC FORCING. RADAR SHOWING SOME -RA ECHOES FROM THIS CLOUD
AS WELL...BUT MOSTLY VIRGA AT THIS POINT. THIS ACTIVITY IS EXPECTED
TO MOVE SOUTHEAST OF THE AREA THIS EVENING WITH CLEARING SKIES AS
HIGH PRESSURE BUILDS INTO AND OVER THE AREA TONIGHT. NORTH/NORTHWEST
DRYING FLOW EXPECTED THROUGH MIDNIGHT AND PERHAPS A FEW HOURS
AFTER UNTIL THE HIGH SETTLES OVERHEAD. THIS SHOULD PRECLUDE ANY
FOG DEVELOPMENT. THE HIGH STARTS TO DRIF EAST OF TEH REGION BY
LATE FRIDAY MORNING..S.ETTING UP AN INCREASING SOUTH FLOW MAINLY
WEST OF THE MISSISSIPPI BY AFTERNOON. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH THE PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
345 PM CDT THU OCT 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1219 PM CDT THU OCT 11 2012
.SHORT TERM...UPDATED FOR TODAY
942 AM CDT THU OCT 11 2012
COLD FRONT MAKING PROGRESS SOUTHWARD ACROSS THE AREA WITH MID-LEVEL
SHORTWAVE MOVING EAST ACROSS LAKE SUPERIOR. RADAR SHOWING SOME
LIGHT SHOWER/SPRINKLE ACTIVITY CURRENTLY ALONG AND IMMEDIATELY
BEHIND THE SURFACE FRONT. RAP SHOWING INCREASING FRONTOGENESIS
THIS AFTERNOON CENTERED AROUND 700MB JUXTAPOSED WITH FAVORED RIGHT
ENTRANCE REGION OF THE 300MB JET MOVING OVERHEAD. BASED ON THIS
FORCING SIGNAL...HAVE ADDED ISOLATED SHOWER MENTION ALONG AND
SOUTH OF I-90 FOR THIS AFTERNOON. TEMPERATURE-WISE...LIKELY NOT TO
SEE TOO MUCH MOVEMENT TODAY WITH CLOUD AND COLD AIR ADVECTION.
WILL HAVE UPDATED FORECAST OUT SOON.
.PREVIOUS SHORT TERM ISSUED 347 AM...THROUGH SATURDAY NIGHT
MAIN FORECAST CONCERNS THIS PACAGE...SHRA/TSRA CHANCES/RAIN AMOUNTS
FRI NIGHT THRU SAT NIGHT...TEMPERATURES THRU THE PERIOD.
DATA ANALYSIS AT 06Z HAD A WAVE OF LOW PRESSURE MOVING EAST ACROSS
CENTRAL MN. RATHER STRONG 3HR PRESSURE FALL/RISE COUPLET WITH THIS
LOW. STRONGEST OF FORCING/LIFT AND SATURATION WITH THIS FEATURE WAS
ACROSS NORTHERN MN/FAR NORTHERN WI...WHERE A BAND OF -RA/-SN WAS
MOVING QUICKLY EAST THRU THE KDLH AREA. ACROSS WEST-CENTRAL MN AND
ALONG THE SD/ND BORDER WEAK 850-700MB FN CONVERGENCE WAS PRODUCING A
BAND OF PATCHY -RA/SCT -SHRA. ALL THIS TRANSLATING EAST-SOUTHEAST
EARLY THIS MORNING. SOUTH OF THE LOW/TRAILING COLD FRONT...SKIES
WERE CLEAR ACROSS IA/FAR SOUTHERN MN INTO FAR SOUTHERN WI. BRISK/
INCREASING SOUTH WINDS AHEAD OF THE LOW/FRONT KEEPING TEMPS WARMER
EARLY THIS MORNING...EVEN UNDER THE CLEAR SKIES.
11.00Z MODELS LOOK TO HAVE INITIALIZED QUITE WELL. SOLUTIONS SIMILAR
THRU 48HRS...THEN BEGIN TO DIVERGE AS THE SOUTHWEST CONUS SYSTEM
TAKES AIM AT THE UPPER MIDWEST FOR FRI NIGHT THRU SAT NIGHT. WHAT
HAD BEEN A TIGHT CONSENSUS NOW TAKES 2 CAMPS AS THE TROUGH/ENERGY
EJECTS INTO/CROSSES THE CENTRAL CONUS. DPROG/DT OF 500MB HGTS AT
11.00Z SHOWED THE MODEL RUNS OF 09.00Z AND 10.00Z ALL VERIFIED WELL
ACROSS NOAM/EASTERN PAC...CONVERGING ON A TIGHT COMPROMISE CONSENSUS
OF THE EARLIER RUNS. SOLUTIONS SIMILAR WITH A TIGHT CONSENSUS AND
GOOD RUN-TO-RUN CONSISTENCY THRU TONIGHT. BY SAT MORNING BETWEEN
MODEL AND RUN-TO-RUN CONSISTENCY DECREASES AS THE TROUGH/LOW OF
INTEREST MOVES THRU THE ROCKIES INTO THE CENTRAL PLAINS. TREND IS
TOWARD MORE OF SPLIT OF THE SHORTWAVE ENERGY BY SAT MORNING.
SOLUTIONS CONTINUE TO DIVERGE WITH THE EVOLUTION/TRACK OF THE MID
LEVEL LOW/TROUGH AS IT LIFTS INTO THE UPPER MIDWEST BY SUN MORNING.
CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED MODELS ALL QUITE GOOD
WITH THE MN LOW AND TRAILING COLD FRONT. MODELS ALL QUITE REASONABLE
WITH THE 00-06Z PRECIP ACROSS NORTHERN MN/WI WITH GFS/ECMWF BETTER
ON THE LIGHT PRECIP OVER WEST CENTRAL MN/ALONG SD/ND BORDER. PER WV
IMAGERY ALL LOOKED GOOD WITH THE NOAM/EASTERN PAC SHORTWAVE DETAILS.
WILL LEAN TOWARD ECMWF/GFS TODAY...THEN CONTINUE TO FAVOR A MODEL/
ENSEMBLE CONSENSUS FOR TONIGHT THRU SAT NIGHT. SHORT TERM FCST
CONFIDENCE GOOD THRU FRI BUT NOW AVERAGE WITH THE STORM SYSTEM FOR
FRI NIGHT THRU SAT NIGHT.
IN THE SHORT TERM...MN LOW WILL CONTINUE TO MOVE QUICKLY EAST THIS
MORNING AND DRAG THE COLD FRONT INTO/ACROSS THE AREA. BAND OF WEAK
FORCING/850-700MB FN CONVERGENCE BEHIND THE FRONT WILL SLIDE ACROSS
THE NORTHERN PARTS OF THE FCST AREA THIS MORNING. WITH OBS UNDER
THE BAND OF PRECIP IN WEST CENTRAL MN CONTINUING TO REPORT
OCCASIONAL -RA AND GFS/ECMWF AND LCL/REGIONAL WRF MODELS PRODUCING
SOME LIGHT PRECIP IN THE NORTH END OF THE FCST AREA THIS MORNING...
EXPANDED SMALL -RA CHANCE TO ALONG/NORTH OF HWY 10 THRU 18Z. BAND
OF POST-FRONTAL CLOUDS WILL SINK SOUTH ACROSS THE AREA AS WELL AND
RAISED SKY COVER/LOWERED HIGHS A BIT FOR TODAY. CLOUDS CLEAR OUT
LATE THIS AFTERNOON/EARLY THIS EVENING AS THE SFC-850MB RIDGE BUILDS
INTO THE AREA AND MDT/STRONG 700-500MB SUBSIDENCE SPREADS OVER THE
AREA. SFC HIGH IS CENTERED OVER THE AREA AT 12Z FRI...WITH LIGHT
WINDS/CLEAR SKIES AND COOL 925-850MB TEMPS. LOOKS LIKE LOWS
EVERYWHERE WILL DROP INTO AT LAST THE 20S...WITH WIDESPREAD
FREEZING TEMPS FINALLY ENDING THE GROWING SEASON IN THOSE ISOLATED
LOCATIONS THAT HAVE ESCAPED FROST/FREEZING SO FAR THIS FALL.
FROST/FREEZE HEADLINES HAVE BEEN TERMINATED FOR THE SEASON...SO NO
HEADLINE WILL BE ISSUED FOR LATE TONIGHT/EARLY FRI MORNING.
THE HIGH MOVES QUICKLY EAST OF THE AREA FRI AS LEE TROUGHING
DEVELOPS FROM MT TO CO. BROAD LOW LEVEL WARM ADVECTION ALREADY
SPREADS ACROSS THE AREA FRI AS THE GRADIENT TIGHTENS...WITH 925MB
TEMPS IN THE +4 TO +7C RANGE BY 00Z SAT. AIRMASS OVER THE AREA
REMAINS DRY THRU FRI...WITH PLENTY OF SUNSHINE AND A DIURNAL TEMP
RISE OF SOME 25-30F FOR MOST AREAS.
LEAD 925-700MB WARM ADVECTION/ISENTROPIC LIFT AND MOISTURE
TRANSPORT/THETA-E CONVERGENCE SPREAD QUICKLY NORTHEAST ACROSS THE
AREA FRI NIGHT. MODELS ALL REMAIN QUITE CONSISTENT WITH THIS
SIGNAL. PREVIOUS GRID SET TRENDED THE 00-03Z PERIOD FRI EVENING
DRY AND THIS LOOKS GOOD...WITH THE MOISTURE/LIFT ARRIVING AROUND
MIDNIGHT. WITH THE CONSISTENT MOISTURE/WARM ADVECTION SIGNAL RAISED
RAIN CHANCES TO 60-90 PERCENT AFTER MIDNIGHT FRI NIGHT. GIVEN THE
STRENGTH OF THE LIFT AND MODELS SHOWING SOME CAPE LIFTING PARCELS IN
THE 800-700MB LAYER...SOME THUNDER LOOKS TO ACCOMPANY THE SHRA AS
THEY LIFT NORTHEAST ACROSS THE AREA FROM LATE EVENING ON.
ON SAT MODELS BEGIN TO DIFFER ON THE DETAILS OF WHERE THE STRONGER
FORCING/LIFT WILL MOVE ACROSS THE FCST AREA. SPLITTING GFS SOLUTION
KEEPS THE STRONGER FORCING OVER THE SOUTHEAST HALF OF THE FCST AREA
SAT INTO SAT NIGHT WHILE OTHER MODELS CONTINUE TO SPREAD STRONG
FORCING ACROSS THE ENTIRE FCST AREA AS THE SFC-MID LEVEL TROUGH
MOVES INTO/ACROSS THE REGION. 90-100 PERCENT SHRA/TSRA CHANCES
ACROSS THE FCST AREA SAT STILL LOOK WARRANTED. DEEPER OF THE
MOISTURE LIFT DOES MOVE EAST OF THE AREA SAT NIGHT. CARRIED HIGHEST
SHRA/TSRA CHANCES OF 60-90 PERCENT SAT EVENING...TRENDING DOWNWARD
AFTER MIDNIGHT AS THE MID LEVEL TROUGH AXIS PASSES.
HIGH TEMPS ON SAT...RESULTING INSTABILITY AND SEVERE TSRA RISK
REMAIN THE SOME OF THE MORE UNCERTAIN ELEMENTS AS THIS SYSTEM
PASSES. MODEL SOUNDINGS FOR SAT SHOW EITHER A DEEPLY SATURATED
COLUMN OR AT LEAST SATURATED BELOW 800MB. FCST GRIDS ARE CARRYING
CLOUDY SKIES SAT...AND THIS BLENDS WILL WITH ALL NEIGHBORS. STILL
APPEARS THE SFC LOW AND ATTENDANT FRONTS WILL BE WEST/NORTH OF THE
FCST AREA UNTIL AFTER 00Z SUN. THIS LIKELY TO LIMIT BOUNDARY LAYER
INVOLVEMENT IN THE SEVERE STORM RISK. APPEARS STRONGER INSTABILITY
OF UP TO 500-1000 J/KG WILL BE ELEVATED. GIVEN THE BROAD FORCING
FOR ASCENT AHEAD OF THE SFC-MID LEVEL TROUGH AND STRONGER SHEAR...
ISOLATED SEVERE TSRA CANNOT BE RULED OUT WITH SWODY3 OKAY FOR NOW.
PW VALUES STILL PROGGED TO BE IN THE 1.5 INCH RANGE LATE FRI NIGHT
INTO SAT EVENING...WITH ANY TSRA CAPABLE OF PRODUCING HEAVY
DOWNPOURS. WITH THE ANTECEDENT DRY CONDITIONS...ANY FLOODING OR
FLASH FLOODING THREAT LOOKS MINIMAL.
GENERALLY FAVORED A BLEND OF THE NUMERICAL GUIDANCE HIGHS/LOWS FOR
TODAY THRU SAT NIGHT. WITH PLENTY OF CLOUDS/SHRA/TSRA EXPECTED
SAT...DID FAVOR COOLER OF GUIDANCE HIGHS.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
347 AM CDT THU OCT 11 2012
11.00Z MEDIUM RANGE MODELS SHOW THE TROUGH/LOW TO BE PROGRESSIVE
SUNDAY...EXITING EAST OF THE AREA BY AFTERNOON. LIMITED SHRA
CHANCES SUN MAINLY TO THE MORNING HOURS. DECENT MODEL CONSISTENCY
FOR BROAD 500MB TROUGHING TO REMAIN OVER THE AREA THRU SUN NIGHT.
ECMWF DROPS A STRONGER SHORTWAVE ACROSS THE AREA IN NORTHWEST FLOW
SUN NIGHT...AND LEFT A SMALL -RA CHANCE ACROSS THE NORTH END OF THE
FCST AREA. MODERATE CONSENSUS FOR WEAK SHORTWAVE RIDGING TO BUILD
THE AREA MON FOR A DRY DAY. PATTERN REMAINS UNSETTLED THRU THE
MIDDLE OF NEXT WEEK AS THE FLOW BECOMES QUASI-ZONAL ACROSS THE
NORTHERN CONUS AND MODELS STRUGGLE WITH THE TIMING/STRENGTH OF
SHORTWAVES THRU THE FLOW. LOOSE CONSENSUS FOR A STRONGER SHORTWAVE
TO CARVE OUT A TROUGH OVER THE UPPER MIDWEST BY WED. SOME SHRA
CHANCES IN THE 20-40 PERCENT RANGE TUE NIGHT/WED...PER THE
MODEL/ENSEMBLE CONSENSUS...LOOK GOOD FOR NOW. WITH THE MORE EAST-
WEST FLOW AND MAIN STORM TRACK ALONG THE US/CAN BORDER...TEMPS FOR
SUN-WED CONTINUE TO TREND NEAR OR ABOVE NORMAL AND THIS WELL
DEPICTED BY THE MODEL CONSENSUS GRID SET.
&&
.AVIATION...THROUGH 18Z FRIDAY
1219 PM CDT THU OCT 11 2012
CURRENTLY WATCHING A COLD FRONT EXITING THE AREA ACROSS EASTERN
WI AND IA. ABUNDANT BKN-OVC ALTOCUMULUS WITH BASES MAINLY AOA
10KFT STILL LINGERING OVER THE AREA IN RESPONSE TO MID-LEVEL
ATMOSPHERIC FORCING. RADAR SHOWING SOME -RA ECHOES FROM THIS CLOUD
AS WELL...BUT MOSTLY VIRGA AT THIS POINT. THIS ACTIVITY IS EXPECTED
TO MOVE SOUTHEAST OF THE AREA THIS EVENING WITH CLEARING SKIES AS
HIGH PRESSURE BUILDS INTO AND OVER THE AREA TONIGHT. NORTH/NORTHWEST
DRYING FLOW EXPECTED THROUGH MIDNIGHT AND PERHAPS A FEW HOURS
AFTER UNTIL THE HIGH SETTLES OVERHEAD. THIS SHOULD PRECLUDE ANY
FOG DEVELOPMENT. THE HIGH STARTS TO DRIF EAST OF TEH REGION BY
LATE FRIDAY MORNING..S.ETTING UP AN INCREASING SOUTH FLOW MAINLY
WEST OF THE MISSISSIPPI BY AFTERNOON. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH THE PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
347 AM CDT THU OCT 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATED SHORT TERM...DAS
LONG TERM....RRS
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1259 PM MDT THU OCT 11 2012
.AVIATION...18Z TAFS. VFR PREVAILS. PERIODS OF SCATTERED MIDDLE
AND HIGH LEVEL CLOUDINESS. SURFACE HIGH PRESSURE MOVES SOUTHEAST
TO EASTERN NORTH DAKOTA THIS AFTERNOON...THEN FURTHER EAST
PRODUCING RETURN SOUTH WINDS ACROSS TAF SITES TONIGHT. SCATTERED
TO BROKEN IFR CEILINGS DEVELOPING BETWEEN 10Z AND 15Z EAST OF
INTERSTATE 25 ON MOIST LOW LEVEL SOUTH WINDS. LOW CLOUDS
DISSIPATING AROUND 15Z. RUBIN
&&
.PREV DISCUSSION... /ISSUED 1010 AM MDT THU OCT 11 2012/
UPDATE...
CURRENT OBS SHOW MVFR CIGS OVER THE NORTHERN HALF OF THE NEBRASKA
PANHANDLE. SOME OF THESE LOW CLOUDS ARE ALSO MOVING INTO EAST
SECTIONS OF GOSHEN AND NIOBRARA COUNTIES. THE HRRR MODEL SHOWS LOW
CLOUDS PERSISTING INTO 20-21Z OVER THE PANHANDLE BUT NOT MAKING
MUCH HEADWAY INTO SOUTHEAST WYOMING. COOLED TEMPS AND INCREASED
CLOUD COVER OVER THE PANHANDLE WITH THE EXPECTATION THAT CLOUDS WILL
BE PERSISTENT THROUGH THE EARLY AFTERNOON.
PREV DISCUSSION... /ISSUED 526 AM MDT THU OCT 11 2012/
AVIATION...12Z TAF ISSUANCE...
VFR EXPECTED OVER ALL TERMINALS THROUGH FRIDAY MORNING THOUGH A
BRIEF PERIOD OF MVFR CIGS STILL POSSIBLE THIS MORNING VCTY KCDR.
SFC COLD FRONT WILL PUSH UP AGAINST THE WY MTNS THIS MORNING THEN
BECOME STNRY THROUGH TONIGHT. WESTERLY FLOW ALOFT THROUGH TONIGHT.
PREV DISCUSSION... /ISSUED 302 AM MDT THU OCT 11 2012/
SHORT TERM...TODAY THROUGH SUNDAY MORNING
FORECAST CHALLENGE DEALS WITH PACIFIC LOW PRESSURE SYSTEM FRIDAY
INTO SATURDAY. SPECIFICALLY...SNOW AMOUNTS AND WINDS.
CURRENTLY...COLD FRONT SAGGING SOUTH INTO EASTERN WYOMING THIS
MORNING. TO THE WEST...LOW PRESSURE OFF THE COAST OF NORTHERN
CALIFORNIA WILL BE OUR NEXT WEATHER PRODUCER...CURRENTLY COMING
ASHORE SOUTH OF SAN FRANCISCO. SEVERAL LIGHTNING STRIKES BEING
OBSERVED WITH THIS SYSTEM.
ATTENTION TURNS TO FRIDAY AS THIS LOW TRACKS INTO WESTERN COLORADO
FRIDAY AFTERNOON. GOOD POSITION FOR US AS WE SET UP GOOD DIFFLUENT
UPPER LEVEL FLOW AND PRECIP SPREADS INTO THE AREA FRIDAY EVENING.
VERY STRONG ISENTROPIC LIFT FORECAST AT ALL LEVELS FRIDAY NIGHT
INTO SATURDAY. ALL MODELS SHOWING HEFTY QPF WITH THIS STORM SYSTEM
WITH FREEZING LEVELS DROPPING TO 9K FEET OR SO. WENT AHEAD WITH A
WINTER STORM WATCH FOR FRIDAY NIGHT THROUGH SATURDAY FOR THE SNOWY
AND SIERRA MADRE RANGES. THIS SYSTEM VERY SIMILAR TO LAST OCTOBERS
SNOW STORM AND WE REALLY NEED TO WATCH TEMPERATURES. WENT BELOW
GUIDANCE ON TEMPERATURES FOR FRIDAY INTO SATURDAY. HAVE A FEELING
THAT I DID NOT GO LOW ENOUGH...BUT WILL CONTINUE TO MONITOR. IF WE
DO COME IN COLDER...WE COULD SEE WINTER STORM CONDITIONS OVER THE
SOUTHERN LARAMIE RANGE. FOR NOW...KEPT THESE ZONES OUT OF THE
WATCH WITH 3 TO 5 INCHES UP THERE.
WINDS BECOME VERY STRONG FRIDAY NIGHT INTO SATURDAY AS WELL. GFS
SHOWING 50KTS AT 700MBS. WENT AHEAD WITH A HIGH WIND WATCH FOR THE
REST OF CARBON AND ALBANY COUNTIES AS WELL AS BORDEAUX FOR THIS
EVENT. LATEST NAM GUIDANCE SHOWING 28KTS SUSTAINED AT RWL FRIDAY
NIGHT AROUND THE 09Z TIME FRAME. WIND DIE DOWN QUICKLY AFTER 12Z
SATURDAY AS THE LOW TRACKS EAST...SO THERE LOOKS TO BE A 6-12 HOUR
WINDOW FRIDAY EVENING WHERE WE COULD SEE THESE STRONG WINDS.
MOST LOCATIONS SHOULD SEE WETTING RAINS WITH THIS EVENT AS A
TROWAL TYPE SIGNATURE SETS UP OVER THE CWFA. THERE ARE SOME
DIFFERENCES IN MODELS ON QPF PLACEMENT WITH THE NAM FURTHER NORTH
THAN THE GFS AND ECMWF. BEST CHANCES FOR PRECIP LOOK TO BE ACROSS
THE SOUTHERN PANHANDLE AND NEAR THE STATE LINE WITH COLORADO.
PRECIP AMOUNTS COULD APPROACH AN INCH IN SOME SPOTS NEAR THE
COLORADO BORDER...INCLUDING CHEYENNE.
UPPER LOW OPENS UP SATURDAY MORNING AND TRACKS QUICKLY NORTHEAST
SATURDAY AFTERNOON. PRECIP TO COME TO AN END SATURDAY AFTERNOON
FOR MOST LOCATIONS.
LONG TERM...SUNDAY THROUGH WEDNESDAY...
PATTERN ACROSS THE AREA THIS PERIOD WILL BE CHARACTERIZED BY
FAIRLY FAST WNW TO NW FLOW ALOFT WITH A COUPLE OF WEAK
DISTURBANCES PASSING ACROSS IN THIS FLOW. TEMPERATURES WILL BE
MILD AS THESE DISTURBANCES WILL BE OF PACIFIC ORIGIN AND NOT HAVE
MUCH IN THE WAY OF COLD AIR WITH THEIR ASSOCIATED FRONTS. BREEZY
TO WINDY PERIODS SHOULD OCCUR AS THE SYSTEMS CAUSE LEE TROFFING TO
DEEPEN AND INCREASE THE PRESSURE GRADIENT...PARTICULARLY MONDAY
INTO TUESDAY. MAINLY DRY OUTSIDE OF THE MTNS WITH DOWNSLOPING FLOW
BEING PREDOMINANT. SOME SHOWERS SHOULD OCCUR OVER THE MTNS WHERE
OROGRAPHICS INTERACT WITH PERIODS OF ENHANCED MOISTURE IN THE
FLOW.
FIRE WEATHER...
COLD FRONT TO SAG DOWN INTO SOUTHEAST WYOMING TODAY...BRINGING
HIGHER DEWPOINTS AND COOLER TEMPERATURES TO AT LEAST THOSE ZONES
EAST OF THE LARAMIE RANGE. GOING TO SEE AN INCREASE IN CLOUDS AND
MOISTURE FRIDAY AS A STRONG PACIFIC STORM SYSTEM TRACKS THROUGH
NORTHERN COLORADO INTO THE PANHANDLE...BRINGING A VERY GOOD CHANCE
OF WETTING VALLEY RAINS AND MOUNTAIN SNOWS. VERY STRONG WINDS
BEHIND THE LOW FRIDAY NIGHT INTO SATURDAY AS THE LOW TRACKS INTO
THE PANHANDLE. WINDS TO CONTINUE INTO SUNDAY BEFORE EASING.
ANOTHER WIND EVENT IN THE OFFING MONDAY AFTERNOON AND PERSISTING
INTO WEDNESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM 6 PM FRIDAY TO 6 PM SATURDAY FOR WYZ112-
WYZ114.
HIGH WIND WATCH FROM 6 PM FRIDAY TO 6 AM SATURDAY FOR WYZ104-
WYZ105-WYZ106-WYZ109-WYZ110-WYZ111-WYZ115-WYZ116.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...CLAYCOMB
LONG TERM/AVIATION...RE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1010 AM MDT THU OCT 11 2012
.UPDATE...
CURRENT OBS SHOW MVFR CIGS OVER THE NORTHERN HALF OF THE NEBRASKA
PANHANDLE. SOME OF THESE LOW CLOUDS ARE ALSO MOVING INTO EAST
SECTIONS OF GOSHEN AND NIOBRARA COUNTIES. THE HRRR MODEL SHOWS LOW
CLOUDS PERSISTING INTO 20-21Z OVER THE PANHANDLE BUT NOT MAKING
MUCH HEADWAY INTO SOUTHEAST WYOMING. COOLED TEMPS AND INCREASED
CLOUD COVER OVER THE PANHANDLE WITH THE EXPECTATION THAT CLOUDS WILL
BE PERSISTENT THROUGH THE EARLY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 526 AM MDT THU OCT 11 2012/
AVIATION...12Z TAF ISSUANCE...
VFR EXPECTED OVER ALL TERMINALS THROUGH FRIDAY MORNING THOUGH A
BRIEF PERIOD OF MVFR CIGS STILL POSSIBLE THIS MORNING VCTY KCDR.
SFC COLD FRONT WILL PUSH UP AGAINST THE WY MTNS THIS MORNING THEN
BECOME STNRY THROUGH TONIGHT. WESTERLY FLOW ALOFT THROUGH TONIGHT.
PREV DISCUSSION... /ISSUED 302 AM MDT THU OCT 11 2012/
SHORT TERM...TODAY THROUGH SUNDAY MORNING
FORECAST CHALLENGE DEALS WITH PACIFIC LOW PRESSURE SYSTEM FRIDAY
INTO SATURDAY. SPECIFICALLY...SNOW AMOUNTS AND WINDS.
CURRENTLY...COLD FRONT SAGGING SOUTH INTO EASTERN WYOMING THIS
MORNING. TO THE WEST...LOW PRESSURE OFF THE COAST OF NORTHERN
CALIFORNIA WILL BE OUR NEXT WEATHER PRODUCER...CURRENTLY COMING
ASHORE SOUTH OF SAN FRANCISCO. SEVERAL LIGHTNING STRIKES BEING
OBSERVED WITH THIS SYSTEM.
ATTENTION TURNS TO FRIDAY AS THIS LOW TRACKS INTO WESTERN COLORADO
FRIDAY AFTERNOON. GOOD POSITION FOR US AS WE SET UP GOOD DIFFLUENT
UPPER LEVEL FLOW AND PRECIP SPREADS INTO THE AREA FRIDAY EVENING.
VERY STRONG ISENTROPIC LIFT FORECAST AT ALL LEVELS FRIDAY NIGHT
INTO SATURDAY. ALL MODELS SHOWING HEFTY QPF WITH THIS STORM SYSTEM
WITH FREEZING LEVELS DROPPING TO 9K FEET OR SO. WENT AHEAD WITH A
WINTER STORM WATCH FOR FRIDAY NIGHT THROUGH SATURDAY FOR THE SNOWY
AND SIERRA MADRE RANGES. THIS SYSTEM VERY SIMILAR TO LAST OCTOBERS
SNOW STORM AND WE REALLY NEED TO WATCH TEMPERATURES. WENT BELOW
GUIDANCE ON TEMPERATURES FOR FRIDAY INTO SATURDAY. HAVE A FEELING
THAT I DID NOT GO LOW ENOUGH...BUT WILL CONTINUE TO MONITOR. IF WE
DO COME IN COLDER...WE COULD SEE WINTER STORM CONDITIONS OVER THE
SOUTHERN LARAMIE RANGE. FOR NOW...KEPT THESE ZONES OUT OF THE
WATCH WITH 3 TO 5 INCHES UP THERE.
WINDS BECOME VERY STRONG FRIDAY NIGHT INTO SATURDAY AS WELL. GFS
SHOWING 50KTS AT 700MBS. WENT AHEAD WITH A HIGH WIND WATCH FOR THE
REST OF CARBON AND ALBANY COUNTIES AS WELL AS BORDEAUX FOR THIS
EVENT. LATEST NAM GUIDANCE SHOWING 28KTS SUSTAINED AT RWL FRIDAY
NIGHT AROUND THE 09Z TIME FRAME. WIND DIE DOWN QUICKLY AFTER 12Z
SATURDAY AS THE LOW TRACKS EAST...SO THERE LOOKS TO BE A 6-12 HOUR
WINDOW FRIDAY EVENING WHERE WE COULD SEE THESE STRONG WINDS.
MOST LOCATIONS SHOULD SEE WETTING RAINS WITH THIS EVENT AS A
TROWAL TYPE SIGNATURE SETS UP OVER THE CWFA. THERE ARE SOME
DIFFERENCES IN MODELS ON QPF PLACEMENT WITH THE NAM FURTHER NORTH
THAN THE GFS AND ECMWF. BEST CHANCES FOR PRECIP LOOK TO BE ACROSS
THE SOUTHERN PANHANDLE AND NEAR THE STATE LINE WITH COLORADO.
PRECIP AMOUNTS COULD APPROACH AN INCH IN SOME SPOTS NEAR THE
COLORADO BORDER...INCLUDING CHEYENNE.
UPPER LOW OPENS UP SATURDAY MORNING AND TRACKS QUICKLY NORTHEAST
SATURDAY AFTERNOON. PRECIP TO COME TO AN END SATURDAY AFTERNOON
FOR MOST LOCATIONS.
LONG TERM...SUNDAY THROUGH WEDNESDAY...
PATTERN ACROSS THE AREA THIS PERIOD WILL BE CHARACTERIZED BY
FAIRLY FAST WNW TO NW FLOW ALOFT WITH A COUPLE OF WEAK
DISTURBANCES PASSING ACROSS IN THIS FLOW. TEMPERATURES WILL BE
MILD AS THESE DISTURBANCES WILL BE OF PACIFIC ORIGIN AND NOT HAVE
MUCH IN THE WAY OF COLD AIR WITH THEIR ASSOCIATED FRONTS. BREEZY
TO WINDY PERIODS SHOULD OCCUR AS THE SYSTEMS CAUSE LEE TROFFING TO
DEEPEN AND INCREASE THE PRESSURE GRADIENT...PARTICULARLY MONDAY
INTO TUESDAY. MAINLY DRY OUTSIDE OF THE MTNS WITH DOWNSLOPING FLOW
BEING PREDOMINANT. SOME SHOWERS SHOULD OCCUR OVER THE MTNS WHERE
OROGRAPHICS INTERACT WITH PERIODS OF ENHANCED MOISTURE IN THE
FLOW.
FIRE WEATHER...
COLD FRONT TO SAG DOWN INTO SOUTHEAST WYOMING TODAY...BRINGING
HIGHER DEWPOINTS AND COOLER TEMPERATURES TO AT LEAST THOSE ZONES
EAST OF THE LARAMIE RANGE. GOING TO SEE AN INCREASE IN CLOUDS AND
MOISTURE FRIDAY AS A STRONG PACIFIC STORM SYSTEM TRACKS THROUGH
NORTHERN COLORADO INTO THE PANHANDLE...BRINGING A VERY GOOD CHANCE
OF WETTING VALLEY RAINS AND MOUNTAIN SNOWS. VERY STRONG WINDS
BEHIND THE LOW FRIDAY NIGHT INTO SATURDAY AS THE LOW TRACKS INTO
THE PANHANDLE. WINDS TO CONTINUE INTO SUNDAY BEFORE EASING.
ANOTHER WIND EVENT IN THE OFFING MONDAY AFTERNOON AND PERSISTING
INTO WEDNESDAY.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM 6 PM FRIDAY TO 6 PM SATURDAY FOR WYZ112-
WYZ114.
HIGH WIND WATCH FROM 6 PM FRIDAY TO 6 AM SATURDAY FOR WYZ104-
WYZ105-WYZ106-WYZ109-WYZ110-WYZ111-WYZ115-WYZ116.
NE...NONE.
&&
$$
UPDATE...FINCH