Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/01/12
AREA FORECAST DISCUSSION
NWS MIAMI FL
1009 AM EDT SAT SEP 29 2012
.UPDATE...NO CHANGES ARE FORTHCOMING IN THE MORNING UPDATES. THE
MID/UPPER LOW THAT WAS OVER SOUTH FLORIDA YESTERDAY AND GENERATED
VERY COLD TEMPERATURES ALOFT HAS MOVE SOUTH OF THE REGION WITH THE
12Z MFL SOUNDING INDICATING MUCH WARMER CONDITIONS HAVE RETURNED
WITH 3 DEGREES CELSIUS OF WARMING AT 50H. THE MID LEVEL LAPSE
RATES ARE ALSO MUCH LESS IMPRESSIVE. ALL OF THIS WILL INHIBIT
THUNDERSTORM GROWTH THIS AFTERNOON AND THE HRRR SHOWS MINIMAL
COVERAGE WHICH SEEMS REASONABLE. SO THE 30 PERCENT POPS LOOK OK AT
THIS TIME WITH THE MARINE ZONES ALSO IN GOOD SHAPE.
KOB
&&
.PREV DISCUSSION... /ISSUED 727 AM EDT SAT SEP 29 2012/
AVIATION...
WIDELY SCATTERED SHRA/ISOLATED TSRA MOVING W THROUGH THE ATLC WATERS
AND OCCASIONALLY ONSHORE. AT THIS TIME VCSH IN E COAST TAFS THROUGH
17Z. E COAST SEA BREEZE WILL BE ESTABLISHED AND SCATTERED TSRA WILL
DEVELOP ALONG THE SEA BREEZE AND THE CONVECTIVE ACTIVITY SHOULD BE
TO THE W OF TERMINALS AND POSSIBLY TOO FAR INLAND TO AFFECT ANY ONE
SITE BUT VCTS IN TAFS THROUGH 21Z. AT KAPF...VCTS AFT 18Z THROUGH
30/00Z AS TSRA DEVELOPING CLOSER TO THAT AREA. LIGHT WINDS AT
SUNRISE WILL BECOME EASTERLY TO NEAR 10 KNOTS ALL TERMINALS AFT 14Z.
AT KAPF...CURRENT SURFACE WIND E AROUND 5 KNOTS BECOMING AFT 13Z
ESE THEN SHIFTING W TO 10 KNOTS AFT 17Z AS W COAST SEA BREEZE
DEVELOPS.
PREV DISCUSSION... /ISSUED 429 AM EDT SAT SEP 29 2012/
DISCUSSION...
A TROUGH OF LOW PRESSURE IS CURRENTLY LOCATED OVER EASTERN CANADA
EXTENDING OVER THE NORTHEASTERN US. A RIDGE OF HIGH PRESSURE
OCCUPIES PART OF WESTERN CANADA AND THE WESTERN US. CURRENT UPPER
LEVEL WINDS SHOW AN AREA OF HIGH PRESSURE IN THE UPPER LEVELS OF THE
ATMOSPHERE OVER NORTHERN MEXICO AND THE SOUTH CENTRAL PORTION OF THE
US. 00Z SAT SEP 29 MIAMI SOUNDING SHOWS EASTERLY FLOW UP TO 600 MB
BRINGING PLENTY OF TROPICAL MOISTURE INTO SOUTH FLORIDA. ABOVE 600
MB THE FLOW BECOMES NORTHERLY, IN PART INFLUENCED BY THE AREA OF
HIGH PRESSURE IN THE UPPER LEVELS OF THE ATMOSPHERE OVER THE SOUTH
CENTRAL US. IN THE NEAR TERM A COLD FRONT EXTENDS FROM CENTRAL TEXAS
INTO THE NE US. FOR SATURDAY THIS FRONT IS FORECAST TO STALL AND
BEGIN TO GENERATE AN AREA OF LOW PRESSURE OVER SE TEXAS EXPECTED TO
MOVE TOWARDS THE MOUTH OF THE MISSISSIPPI RIVER BY SUNDAY. THE UPPER
LEVEL WINDS ARE FORECAST TO AMPLIFY ON MONDAY OVER THE CENTRAL AND
SE US PRODUCING AN EXTENSIVE AREA OF SOUTHERLY WINDS OVER THE GULF
OF MEXICO AND THE FLORIDA PENINSULA. THIS SOUTHERLY WINDS ARE
EXPECTED TO INCREASE UP TO 25 KTS AT 850 MB WITH SURFACE WINDS UP TO
15 TO 20 KTS OVER THE ATLANTIC COASTAL WATERS POSSIBLE. GUSTY WINDS
ARE ALSO EXPECTED OVER THE SOUTHERN AND EASTERN PORTIONS OF SOUTH
FLORIDA, ESPECIALLY ON MONDAY. THE AREA OF LOW PRESSURE OVER THE
SOUTH CENTRAL US LIFTS NORTHEASTWARD ON TUESDAY PUSHING A COLD FRONT
OVER THE SE US. HOWEVER, THE FRONT IS NOT EXPECTED TO PUSH PAST THE
CENTRAL PORTIONS OF THE FLORIDA PENINSULA. EASTERLY WINDS RETURN TO
SOUTH FLORIDA ON WEDNESDAY, AS AN AREA OF HIGH PRESSURE BUILDS BACK
IN THE WESTERN ATLANTIC AND INFLUENCES OUR WEATHER BETWEEN WEDNESDAY
AND THE END OF THE FORECAST PERIOD.
VERY LITTLE CHANGE IN TEMPERATURES IS EXPECTED FOR THE FORECAST
PERIOD. HOWEVER, THE DEWPOINT TEMPERATURE IS EXPECTED TO INCREASE
AFTER MONDAY AND TUESDAY WHICH WILL INCREASE THE LOW TEMPERATURES
ESPECIALLY OVER THE EASTERN AND SOUTHERN SECTIONS OF SOUTH FLORIDA.
THE COVERAGE OF THE PRECIPITATION FORECAST FOR SATURDAY AND SUNDAY
IS FORECAST TO BE SLIGHTLY DIFFERENT. FOR SATURDAY MOST OF THE
SHOWERS AND ISOLATED THUNDERSTORMS ARE FORECAST OVER THE INTERIOR
SECTIONS, AS EAST AND WEST COAST SEA BREEZES PUSH INLAND. FOR
SUNDAY, THERE COULD BE AN INCREASE IN SHOWERS OVER THE ATLANTIC
WATERS BEGINNING SUNDAY MORNING WHICH IS EXPECTED TO SPREAD FROM THE
SE TO THE INTERIOR AS THE DAY PROGRESSES. THE GREATEST CHANCE FOR
SHOWERS AND ISOLATED THUNDERSTORMS IS EXPECTED FOR MONDAY AND
TUESDAY. FROM WEDNESDAY THROUGH THE END OF THE FORECAST PERIOD A
MOIST EASTERLY FLOW WILL DOMINATE, WHICH IS EXPECTED TO CONCENTRATE
SHOWERS AND ISOLATED STORMS IN THE INTERIOR DURING THE AFTERNOON AND
EVENING, AND OVER THE ATLANTIC COASTAL WATERS DURING THE NIGHT AND
EARLY MORNING HOURS.
AVIATION...(ISSUED AT 125 AM EDT SAT SEP 29 2012). A FEW STRAY
SHRA/POSSIBLE ISOLATED TSRA SLOWLY MOVING W THROUGH THE ATLC WATERS
BUT NOTHING IN E COAST TAFS AT THIS TIME UNTIL THE E COAST SEA
BREEZE GETS ESTABLISHED AND VCSH AFT 14Z. TSRA EXPECTED AFT 17Z WITH
VCTS IN E COAST TAFS. ACTIVITY SHOULD BE TO THE W OF TERMINALS AND
POSSIBLY TOO FAR INLAND TO AFFECT SITE BUT VCTS IN TAFS THROUGH 21Z.
KTMB MOST VULNERABLE TO SEE A TSRA. AT KAPF...POSSIBLE MVFR VSBY IN
BR FROM 09Z TO 12Z THEN AFT 20Z VCTS THROUGH 30/00Z. E COAST SURFACE
WINDS CURRENTLY CALM TO NNW-N < 5 KNOTS BUT BECOMING EASTERLY TO
NEAR 10 KNOTS AFT 14Z. AT KAPF...VCTS FROM 20Z TO 30/00Z. CURRENT
SURFACE WIND CALM BECOMING AFT 13Z ESE < 5 KNOTS THEN SHIFTING W TO
10 KNOTS AFT 17Z AS W COAST SEA BREEZE DEVELOPS.
MARINE...LIGHT EAST TO NORTHEAST WINDS ARE FORECAST FOR SATURDAY.
FOR SUNDAY WINDS ARE FORECAST TO SHIFT FROM EASTERLY TO
SOUTHEASTERLY AS A TROUGH OF LOW PRESSURE AMPLIFIES OVER THE SE US.
WINDS ARE EXPECTED TO SHIFT FROM THE SOUTH ON MONDAY AND INCREASE
TO 15 TO 20 KTS OVER THE ATLANTIC COASTAL WATERS. BY WEDNESDAY
WINDS OVER THE ATLANTIC WATERS ARE FORECAST TO DECREASE FROM SOUTH
TO NORTH. WAVE HEIGHTS OF 2 TO 3 FEET ARE FORECAST FOR THE PALM
BEACH COASTAL WATERS FOR THE MONDAY-TUESDAY TIME FRAME. SEAS ARE ALSO
EXPECTED TO INCREASE TO ABOUT 4 FEET ACROSS THE OUTER GULF ZONES
BY TUESDAY.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS. THE LOWEST AFTERNOON RH VALUES FOR THE
ENTIRE FORECAST PERIOD ARE EXPECTED TO OCCUR ON SATURDAY. HOWEVER,
THE VALUES ARE EXPECTED TO BE ABOVE 45 PERCENT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 77 88 77 / 20 20 40 40
FORT LAUDERDALE 88 77 88 79 / 20 20 40 40
MIAMI 89 77 89 78 / 20 20 50 40
NAPLES 89 75 89 77 / 20 20 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
1000 AM EDT SAT SEP 29 2012
.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE AREA WILL CONTINUE TO WEAKEN AND
SLIDE FARTHER TO THE SOUTH/SOUTHEAST. THIS WILL ALLOW A COLD FRONT
TO MOVE SLOWLY ACROSS THE REGION TODAY. A LOW PRESSURE SYSTEM OVER
TEXAS WILL MOVE NORTHEAST...SPREADING RAIN OVER THE AREA FOR EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A COLD FRONT WAS NORTH OF THE MIDLANDS THIS MORNING. A BAND OF
SHOWERS WITH A FEW THUNDERSTORMS WAS LOCATED IN THE NORTH PART
OF THE FORECAST AREA MOVING EAST WITH THE UPPER ZONAL FLOW. BOTH
NAM AND RUC MODELS SHOW UPPER LOW NORTH AND A WEAK SHORT WAVE WITH
ROUNDS THIS FEATURE THIS AFTERNOON. THIS IS EXPECTED TO HELP TO
PULL THE COLD FRONT SOUTHWARD INTO THE REGION LATE THIS AFTERNOON
OR EARLY THIS EVENING. INCREASED POPS TO 40-50 PERCENT SOUTH AND
60-80 PERCENT NORTH. OTHERWISE...EXPECT MODERATE INSTABILITY
AHEAD OF THE FRONT WITH PWAT INCREASING TO ABOUT 1.80 INCHES.
COULD SEE A ANOTHER WEAK SHORT WAVE MOVE THROUGH TONIGHT IN
CYCLONIC FLOW ALOFT AS AN UPPER LOW SPINS OVER THE GREAT LAKES
REGION. KEPT POP AT 30 TO 40 PERCENT THROUGH TONIGHT. WENT WITH
CONSENSUS FOR HIGHS IN THE LOW TO MID 80S UNDER MOSTLY CLOUDY
SKIES. MODELS PUSH THE COLD FRONT SOUTH OF THE CSRA OVERNIGHT WITH
POPS DECREASING. SHOULD SEE OVERNIGHT LOWS IN THE LOW TO MID 60S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE COLD FRONT SHOULD BE SOUTH OF THE AREA SUNDAY MORNING. MODELS
SHOWING AN INCREASE IN MOISTURE SUNDAY AFTERNOON AS A FRONT
PUSHES BACK NORTH. LOW PRESSURE IS EXPECTED MOVE NORTHWARD ALONG
THE FRONT FROM THE LOWER MS RIVER VALLEY TO THE TN VALLEY MONDAY
NIGHT. WHILE THE GFS IS FASTER IN SPREADING ISENTROPIC LIFT
NORTHWARD...ALL MODELS INDICATE AN INCREASE IN MOISTURE FLUX
SUNDAY NIGHT THROUGH MONDAY. WILL KEEP HIGH CHANCE TO LIKELY POPS
SUNDAY NIGHT INTO MONDAY NIGHT. CLOUDS AND PRECIP EXPECTED TO HOLD
DAYTIME HIGHS IN THE MID 70S TO LOWER 80S. NIGHT-TIME LOWS IN THE
60S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE MEDIUM RANGE MODELS HAVE THE LOW PRESSURE SYSTEM LIFTING
NORTH OF THE AREA TUESDAY. AN UPPER LEVEL LOW WILL LINGER JUST
WEST OF THE AREA THROUGH MID-WEEK BEFORE OPENING UP AND LIFTING
NORTHEAST THURSDAY. KEPT CHANCE POPS FOR TUESDAY THROUGH WEDNESDAY
NIGHT. MAY BEGIN TO FINALLY SEE SOME DRYING AGAIN AS WE MOVE INTO
THURSDAY AS THE MAIN UPPER TROUGH GETS NEAR ENOUGH TO PUSH THE
SURFACE FRONT AND ITS ASSOCIATED MOISTURE OFF THE COAST. AS FOR
TEMP...CONTINUED WITH A BLEND OF MODEL GUIDANCE WHICH GENERALLY
KEEPS READINGS A FEW DEGREES BELOW CLIMATOLOGY.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
MIXED CONDITIONS POSSIBLE THROUGH THE TAF PERIOD. FRONTAL BOUNDARY
CONTINUES TO APPROACH THE AREA WITH WSR-88D RETURNS SHOWING SHOWERS
MOVING THROUGH THE UPSTATE INTO THE NORTHERN MIDLANDS. MAIN CONCERN
IS RAIN POTENTIAL THROUGH THE AFTERNOON...AND WITH CONFIDENCE
REMAINING LOW HAVE INCLUDED VCSH FOR ALL TAF SITES FROM 15Z-16Z
THROUGH 30/00Z. WV LOOP MID/UPPER FLOW TO BE MORE WEST/WEST
NORTHWEST ACROSS THE AREA...THIS WILL LIKELY PRODUCE A SLOW MOVEMENT
SOUTHWARD IN THE PRECIPITATION FIELD. EXPECT THE BEST CHANCE OF RAIN
IN CAE/CUB...HOWEVER CONFIDENCE IN TIMING REMAINS TOO LOW TO INCLUDE
IN TAFS. EXPECT MUCH OF THE RAIN TO DIMINISH WITH SUNSET AND FOG
CHANCE WILL BE LOWER TONIGHT AS CLOUD COVER WILL PERSIST OVER THE
AREA.
EXTENDED AVIATION OUTLOOK...CHANCE OF PRECIPITATION AND ASSOCIATED
RESTRICTIONS THROUGH MID WEEK...WITH LOWER CIGS EXPECTED LATE
NIGHT/EARLY MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
913 AM EDT SAT SEP 29 2012
.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE AREA HIGH PRESSURE WILL CONTINUE TO
WEAKEN AND SLIDE FARTHER TO THE SOUTH/SOUTHEAST. THIS WILL ALLOW A
COLD FRONT TO MOVE SLOWLY ACROSS THE REGION TODAY. A LOW PRESSURE
SYSTEM OVER TEXAS WILL MOVE NORTHEAST...SPREADING RAIN OVER THE
AREA FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A COLD FRONT WAS NORTH OF THE MIDLANDS THIS MORNING. A BAND OF
SHOWERS WITH A FEW THUNDERSTORMS WAS LOCATED IN THE NORTH PART
OF THE FORECAST AREA MOVING EAST WITH THE UPPER ZONAL FLOW. BOTH
NAM AND RUC MODELS SHOW UPPER LOW NORTH AND A WEAK SHORT WAVE WITH
ROUNDS THIS FEATURE THIS AFTERNOON. THIS IS EXPECTED TO HELP TO
PULL THE COLD FRONT SOUTHWARD INTO THE REGION LATE THIS AFTERNOON
OR EARLY THIS EVENING. INCREASED POPS TO 40-50 PERCENT SOUTH AND
60-80 PERCENT NORTH. OTHERWISE...EXPECT MODERATE INSTABILITY
AHEAD OF THE FRONT WITH PWAT INCREASING TO ABOUT 1.80 INCHES.
COULD SEE A ANOTHER WEAK SHORT WAVE MOVE THROUGH TONIGHT IN
CYCLONIC FLOW ALOFT AS AN UPPER LOW SPINS OVER THE GREAT LAKES
REGION. KEPT POP AT 30 TO 40 PERCENT THROUGH TONIGHT. WENT WITH
CONSENSUS FOR HIGHS IN THE LOW TO MID 80S UNDER MOSTLY CLOUDY
SKIES. MODELS PUSH THE COLD FRONT SOUTH OF THE CSRA OVERNIGHT WITH
POPS DECREASING. SHOULD SEE OVERNIGHT LOWS IN THE LOW TO MID 60S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE COLD FRONT SHOULD BE SOUTH OF THE AREA SUNDAY MORNING. MODELS
SHOWING AN INCREASE IN MOISTURE SUNDAY AFTERNOON AS A FRONT
PUSHES BACK NORTH. LOW PRESSURE IS EXPECTED MOVE NORTHWARD ALONG
THE FRONT FROM THE LOWER MS RIVER VALLEY TO THE TN VALLEY MONDAY
NIGHT. WHILE THE GFS IS FASTER IN SPREADING ISENTROPIC LIFT
NORTHWARD...ALL MODELS INDICATE AN INCREASE IN MOISTURE FLUX
SUNDAY NIGHT THROUGH MONDAY. WILL KEEP HIGH CHANCE TO LIKELY POPS
SUNDAY NIGHT INTO MONDAY NIGHT. CLOUDS AND PRECIP EXPECTED TO HOLD
DAYTIME HIGHS IN THE MID 70S TO LOWER 80S. NIGHT-TIME LOWS IN THE
60S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE MEDIUM RANGE MODELS HAVE THE LOW PRESSURE SYSTEM LIFTING
NORTH OF THE AREA TUESDAY. AN UPPER LEVEL LOW WILL LINGER JUST
WEST OF THE AREA THROUGH MID-WEEK BEFORE OPENING UP AND LIFTING
NORTHEAST THURSDAY. KEPT CHANCE POPS FOR TUESDAY THROUGH WEDNESDAY
NIGHT. MAY BEGIN TO FINALLY SEE SOME DRYING AGAIN AS WE MOVE INTO
THURSDAY AS THE MAIN UPPER TROUGH GETS NEAR ENOUGH TO PUSH THE
SURFACE FRONT AND ITS ASSOCIATED MOISTURE OFF THE COAST. AS FOR
TEMP...CONTINUED WITH A BLEND OF MODEL GUIDANCE WHICH GENERALLY
KEEPS READINGS A FEW DEGREES BELOW CLIMATOLOGY.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
MIXED CONDITIONS POSSIBLE THROUGH THE TAF PERIOD. FRONTAL BOUNDARY
CONTINUES TO APPROACH THE AREA WITH WSR-88D RETURNS SHOWING SHOWERS
MOVING THROUGH THE UPSTATE INTO THE NORTHERN MIDLANDS. MAIN CONCERN
IS RAIN POTENTIAL THROUGH THE AFTERNOON...AND WITH CONFIDENCE
REMAINING LOW HAVE INCLUDED VCSH FOR ALL TAF SITES FROM 15Z-16Z
THROUGH 30/00Z. WV LOOP MID/UPPER FLOW TO BE MORE WEST/WEST
NORTHWEST ACROSS THE AREA...THIS WILL LIKELY PRODUCE A SLOW MOVEMENT
SOUTHWARD IN THE PRECIPITATION FIELD. EXPECT THE BEST CHANCE OF RAIN
IN CAE/CUB...HOWEVER CONFIDENCE IN TIMING REMAINS TOO LOW TO INCLUDE
IN TAFS. EXPECT MUCH OF THE RAIN TO DIMINISH WITH SUNSET AND FOG
CHANCE WILL BE LOWER TONIGHT AS CLOUD COVER WILL PERSIST OVER THE
AREA.
EXTENDED AVIATION OUTLOOK...CHANCE OF PRECIPITATION AND ASSOCIATED
RESTRICTIONS THROUGH MID WEEK...WITH LOWER CIGS EXPECTED LATE
NIGHT/EARLY MORNING.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
07
AREA FORECAST DISCUSSION...ADDITIONAL INFO ADDED IN THE UPDATE
NWS LOUISVILLE KY
937 PM EDT SUN SEP 30 2012
.Forecast Update...
Updated at 905 PM EDT Sat Sep 29 2012
Only minor updates needed to the forecast this evening. Rain is
making steady progress northward over TN. According to a combo of
latest obs, radar imagery, and latest RAP model, we should start to
see some light rain along the KY/TN border in a few hours. Tweaked
POPs just a bit to reflect slightly quicker rain arrival in the Lake
Cumberland region than was previously forecast. Also, tweaked temps
up a degree or two based on current obs and GEMregBC guidance which
is performing the best this evening.
On a separate note, SDF looks to come in 9th for wettest Sept with
5.83 inches of precip. Sept precip at BWG, LEX, FFT did not make
the top ten wettest Sept.
&&
.Short Term (Today through Monday night)...
Issued at 330 PM EDT Sun Sep 30 2012
Cirrus continues to thicken over the CWA this afternoon in advance
of a surface Low over Louisiana that will inch its way toward us
during the period. The large swath of rain currently extending from
northern Arkansas to northern Alabama will move northeast tonight,
reaching the counties along the Tennessee border before sunrise, and
continuing to spread north toward the Ohio River by mid day. While
there are some slight differences between the major models in timing
and the exact placement of the max precip area, the consensus is a
rainy Monday for all. Though the bulk of the precip will fall as
light to moderate rain, some isolated thunder may produce higher
rain rates during the afternoon and evening hours. Overall, it
should be a good soaker for nearly all of the forecast area.
With the blanket of cirrus already in place, overnight lows should
be about 5 degrees warmer than this morning, ranging from 49 to 59.
After warming up slightly ahead of the rainfall, readings will
flatten out as the rain starts, making for a chilly day with highs
only in the 60s, some 10 to 15 degrees below seasonal norms.
With rainfall lingering into Monday night as the surface Low slowly
pushes toward the Ohio Valley, little temperature fluctuation will
occur, with most lows in the 55 to 60 degree range.
.Long Term (Tuesday through Sunday)...
Issued at 315 PM EDT Sun Sep 30 2012
Model solutions have been trending slower with the departure of the
Gulf low, which calls for the surface low to track across Kentucky
Tuesday. This will keep the chance of showers going across the area.
The surface low is expected to move over the Great Lakes by
Wednesday morning, with the upper trough lingering across the Ohio
Valley. With the upper trough still in play, will have to continue a
chance of showers into at least Wednesday morning, perhaps early
afternoon, with the northern forecast area experiencing the best
chance. This low should finally get a kick from an approaching
trough and shove off to the northeast. Things should dry out
Wednesday night and Thursday ahead of our next system, which the
models are not handling all that well.
The 30.12Z GFS has been much more amplified with the approaching
upper trough for the end of the work week than the 30.12Z ECMWF.
This is critical for the overall evolution of the system. The GFS
rockets a cold front through the area Thursday night and through the
day Friday, while the ECMWF brings a much weaker front into the area
and stalls it just to our north, paralleling basically zonal flow
aloft. So, the GFS solution brings showers and perhaps a few
thunderstorms to the area late Thursday and Friday, with the ECMWF
keeping the area dry until Saturday and Sunday when it finally edges
the front into our area. And of course temperatures vary quite a bit
between all guidance, which makes this a difficult forecast. So, for
now, will follow national, regional, and local collaborative efforts
to side more with the GFS/GEFS solution, which has shown run-to-run
consistency over the last few days.
As for temperatures, highs right around 70 will be common Tuesday
and Wednesday. Temperatures Thursday should reach the mid and upper
70s with mostly clear skies ahead of the approaching front. With the
frontal passage Friday, temperatures will only top out in the upper
60s and low 70s. For the weekend, temperatures in the low to mid 60s
will be common. Low temperatures should be in the 50s Tuesday night
through Thursday night, and then in the 40s behind the front Friday
night and Saturday night. Of course, these temperatures will likely
change as model output converges toward a common solution. Stay
tuned!
&&
.Aviation (00Z TAF Issuance)...
Issued at 740 PM EDT Sun Sep 30 2012
Main aviation concern will be the arrival of steady rains along with
reduced vsbys/cigs (LIFR-IFR at worst) into the TAF sites. This
rain is courtesy of a low pressure system pushing northward from the
Gulf States. Latest observations at 2330Z indicate rain reaching
the ground as far north as southwest TN with virga likely falling
aloft over portions of central TN. According to AMDAR soundings
decent dry layers exist at the sfc and aloft over the region, so
will take that into account in timing the precip into the TAF
sites. Have used a combo of RAP, NAM 4km, and NAM 12km models for
this forecast.
BWG...will be the first to see steady rains starting around 9Z.
MVFR vsbys and IFR cigs will be quick to build in once steady rains
begin around 11Z. BWG may even experience a period of moderate
rains with LIFR conditions between 11-15Z. After 15Z, steady rains
should begin to break up a bit and become more showery in nature
with an isld t-storm not out of the question. Will not include
thunder for this TAF issuance since chances are slim, but will
indicate -SHRA to signal a slightly deeper convective type precip
mode vs earlier stratiform rains.
SDF/LEX...will see steady rains starting around 13-14Z. MVFR vsbys
and IFR cigs will gradually build in once steady rains begin around
17-18Z. SDF/LEX may even experience a period of moderate rains with
IFR vsbys as well between 17-22Z. LIFR conditions aren`t out of the
question, but did not feel confident enough to include in the TAFs
at this time. After 21-22Z, steady rains should begin to break up
a bit and become more showery in nature with an isld t-storm not
out of the question. Will not include thunder for this TAF issuance
since chances are slim, but will indicate -SHRA to signal a slightly
deeper convective type precip mode vs earlier stratiform rains.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS
Short Term.......JBS
Long Term........MJP
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
923 PM EDT SUN SEP 30 2012
.Forecast Update...
Updated at 905 PM EDT Sat Sep 29 2012
Only minor updates needed to the forecast this evening. Rain is
making steady progress northward over TN. According to a combo of
latest obs, radar imagery, and latest RAP model, we should start to
see some light rain along the KY/TN border in a few hours. Tweaked
POPs just a bit to reflect slightly quicker rain arrival in the Lake
Cumberland region than was previously forecast. Also, tweaked temps
up a degree or two based on current obs and GEMregBC guidance which
is performing the best this evening.
&&
.Short Term (Today through Monday night)...
Issued at 330 PM EDT Sun Sep 30 2012
Cirrus continues to thicken over the CWA this afternoon in advance
of a surface Low over Louisiana that will inch its way toward us
during the period. The large swath of rain currently extending from
northern Arkansas to northern Alabama will move northeast tonight,
reaching the counties along the Tennessee border before sunrise, and
continuing to spread north toward the Ohio River by mid day. While
there are some slight differences between the major models in timing
and the exact placement of the max precip area, the consensus is a
rainy Monday for all. Though the bulk of the precip will fall as
light to moderate rain, some isolated thunder may produce higher
rain rates during the afternoon and evening hours. Overall, it
should be a good soaker for nearly all of the forecast area.
With the blanket of cirrus already in place, overnight lows should
be about 5 degrees warmer than this morning, ranging from 49 to 59.
After warming up slightly ahead of the rainfall, readings will
flatten out as the rain starts, making for a chilly day with highs
only in the 60s, some 10 to 15 degrees below seasonal norms.
With rainfall lingering into Monday night as the surface Low slowly
pushes toward the Ohio Valley, little temperature fluctuation will
occur, with most lows in the 55 to 60 degree range.
.Long Term (Tuesday through Sunday)...
Issued at 315 PM EDT Sun Sep 30 2012
Model solutions have been trending slower with the departure of the
Gulf low, which calls for the surface low to track across Kentucky
Tuesday. This will keep the chance of showers going across the area.
The surface low is expected to move over the Great Lakes by
Wednesday morning, with the upper trough lingering across the Ohio
Valley. With the upper trough still in play, will have to continue a
chance of showers into at least Wednesday morning, perhaps early
afternoon, with the northern forecast area experiencing the best
chance. This low should finally get a kick from an approaching
trough and shove off to the northeast. Things should dry out
Wednesday night and Thursday ahead of our next system, which the
models are not handling all that well.
The 30.12Z GFS has been much more amplified with the approaching
upper trough for the end of the work week than the 30.12Z ECMWF.
This is critical for the overall evolution of the system. The GFS
rockets a cold front through the area Thursday night and through the
day Friday, while the ECMWF brings a much weaker front into the area
and stalls it just to our north, paralleling basically zonal flow
aloft. So, the GFS solution brings showers and perhaps a few
thunderstorms to the area late Thursday and Friday, with the ECMWF
keeping the area dry until Saturday and Sunday when it finally edges
the front into our area. And of course temperatures vary quite a bit
between all guidance, which makes this a difficult forecast. So, for
now, will follow national, regional, and local collaborative efforts
to side more with the GFS/GEFS solution, which has shown run-to-run
consistency over the last few days.
As for temperatures, highs right around 70 will be common Tuesday
and Wednesday. Temperatures Thursday should reach the mid and upper
70s with mostly clear skies ahead of the approaching front. With the
frontal passage Friday, temperatures will only top out in the upper
60s and low 70s. For the weekend, temperatures in the low to mid 60s
will be common. Low temperatures should be in the 50s Tuesday night
through Thursday night, and then in the 40s behind the front Friday
night and Saturday night. Of course, these temperatures will likely
change as model output converges toward a common solution. Stay
tuned!
&&
.Aviation (00Z TAF Issuance)...
Issued at 740 PM EDT Sun Sep 30 2012
Main aviation concern will be the arrival of steady rains along with
reduced vsbys/cigs (LIFR-IFR at worst) into the TAF sites. This
rain is courtesy of a low pressure system pushing northward from the
Gulf States. Latest observations at 2330Z indicate rain reaching
the ground as far north as southwest TN with virga likely falling
aloft over portions of central TN. According to AMDAR soundings
decent dry layers exist at the sfc and aloft over the region, so
will take that into account in timing the precip into the TAF
sites. Have used a combo of RAP, NAM 4km, and NAM 12km models for
this forecast.
BWG...will be the first to see steady rains starting around 9Z.
MVFR vsbys and IFR cigs will be quick to build in once steady rains
begin around 11Z. BWG may even experience a period of moderate
rains with LIFR conditions between 11-15Z. After 15Z, steady rains
should begin to break up a bit and become more showery in nature
with an isld t-storm not out of the question. Will not include
thunder for this TAF issuance since chances are slim, but will
indicate -SHRA to signal a slightly deeper convective type precip
mode vs earlier stratiform rains.
SDF/LEX...will see steady rains starting around 13-14Z. MVFR vsbys
and IFR cigs will gradually build in once steady rains begin around
17-18Z. SDF/LEX may even experience a period of moderate rains with
IFR vsbys as well between 17-22Z. LIFR conditions aren`t out of the
question, but did not feel confident enough to include in the TAFs
at this time. After 21-22Z, steady rains should begin to break up
a bit and become more showery in nature with an isld t-storm not
out of the question. Will not include thunder for this TAF issuance
since chances are slim, but will indicate -SHRA to signal a slightly
deeper convective type precip mode vs earlier stratiform rains.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS
Short Term.......JBS
Long Term........MJP
Aviation.........AMS
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
731 PM EDT SUN SEP 30 2012
.SYNOPSIS...
LOW PRESSURE OVER THE BAY OF FUNDY WILL LIFT NORTH THROUGH EASTERN
QUEBEC TONIGHT AND MONDAY. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD
OVER NEW ENGLAND MONDAY NIGHT AND WILL HOLD OVER THE AREA ON
TUESDAY. A TROUGH OF LOW PRESSURE WILL SLOWLY MOVE NORTHWARD UP THE
EAST COAST TUESDAY NIGHT AND WEDNESDAY. A COLD FRONT WILL APPROACH
FROM THE WEST WEDNESDAY NIGHT AND WILL CROSS THE REGION ON THURSDAY.
ANOTHER COLD FRONT WILL APPROACH FROM THE THE WEST ON FRIDAY AND
WILL PUSH EAST THROUGH THE REGION FRIDAY NIGHT. A WEAK RIDGE OF HIGH
PRESSURE WILL BUILD IN BEHIND THE FRONT ON SATURDAY AND WILL HOLD
OVER THE REGION ON SUNDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE...STEADY PCPN HAS MOVED MOST N OF THE CWFA ATTM AS ONE MAIN
S/WV TROF HAS PUSHED OVERHEAD. SEEING A BRIEF PERIOD OF CLEARING
IN THE INTERIM AS SUBSIDENCE ACTS WITH SOME WEAK DOWNSLOPING TO
BREAK UP CLOUDS. SOME DIURNALLY DRIVEN TSTMS HAVE WEAKENED TO THE
POINT OF A FEW ISOLD LIGHTNING STRIKES...BUT SECONDARY S/WV
ROTATION THRU THE UPR TROF WILL HELP MAINTAIN THESE SHRA INTO SRN
ZONES. HAVE CONTINUED TO FAVOR THE HRRR POP FIELD BLENDED WITH
PREVIOUS FCST GRIDS TO BRING AN AREA OF LIKELY TO HIGH CHC POP
ACROSS SRN NH INTO SWRN ME IN THE NEXT SEVERAL HRS. AS THESE
TRANSITION EWD...REST OF THE OVERNIGHT WILL BECOME MORE MTN SHRA
AND CLOUDS AS FLOW BECOMES MORE NWLY.
PREVIOUS DISCUSSION...SURFACE LOW PRESSURE CONTINUES TO MOVE
NORTHWARD AND INTO DOWNEAST MAINE AS OF LATE THIS SUNDAY
AFTERNOON. AS IT DOES SO...THE SHIELD OF STRATIFORM RAIN CONTINUES
TO MOVE NORTHWARD AS WELL...WITH THE BACK EDGE ALONG A LINE FROM
PORTLAND ME WESTWARD TO LITTLETON NH. THE STEADY RAINFALL WILL END
WITH THE NORTHWARD PASSAGE OF THE BACK EDGE. HOWEVER...THE STRONG
UPPER LOW IS STILL APPROACHING FROM THE WEST...SO SHOWERY
PRECIPITATION IS DEVELOPING IN THE DRIER AREA TO THE SOUTHWEST.
THEREFORE...HAVE NOT SCALED BACK ON POPS TOO MUCH IN THE SOUTH
EARLY THIS EVENING. CANNOT RULE OUT AN ISOLD THUNDERSTORM ACROSS
SOUTHERN NH TIL ABOUT 00Z...BUT DECIDED TO LEAVE OUT OF FORECAST
AS PROBABILITY SEEMS LOW AT THIS TIME.
AFTER DARK...THE SHOWERY PRECIP WILL WANE. THIS SHOULD LEAVE THE
SOUTHERN ZONES AND COASTAL PLAIN MAINLY DRY OVERNIGHT.
HOWEVER...DIDN/T GET RID OF POPS COMPLETELY...AS UPPER LOW IS
STRONG ENOUGH TO INDUCE A FEW SHOWERS FROM TIME TO TIME. IT/S ALSO
POSSIBLE THAT A LARGER AREA OF WRAP AROUND SHOWERS DEVELOPS LATE
ALSO.
ACROSS CENTRAL AND NORTHERN NH AND THE WESTERN ME
MOUNTAINS...EXPECT NUMEROUS SHOWERS TO CONTINUE OVERNIGHT...WITH A
GOOD CONTRIBUTION COMING FROM WESTERLY UPSLOPE.
MIN TEMPS BASED ON A BLEND OF THE MET/MAV/NAM GUIDANCE.
&&
.SHORT TERM /MONDAY NIGHT/...
STACKED LOW PRESSURE SYSTEM WILL LIKELY BE CENTERED OVER MAINE 8
AM MONDAY MORNING WITH WRAP AROUND SHOWERY PRECIP LIKELY OCCURRING
OVER MUCH OF THE AREA. THE HIGHEST CONCENTRATION WILL BE OVER THE
MOUNTAINS. CANNOT RULE OUT AN ISOLATED THUNDERSTORM WITH STEEP
LAPSE RATES IN PLACE...BUT PROBABILITY IS A LITTLE TO LOW AT THIS
TIME TO INCLUDE IN THE FORECAST. TIMING OF UPPER LOW PASSAGE IS
JUST A LITTLE TOO QUICK WITH RESPECT TO DAYTIME HEATING AT THIS
TIME.
OTHERWISE...GRADUAL DRYING TAKES PLACE MONDAY AFTERNOON. UPSLOPE
SHOWERS PROBABLY STILL OCCUR IN THE MOUNTAINS HOWEVER.
CLEARING MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL PROVIDE MOSTLY SUNNY SKIES ON TUESDAY AS HIGH
PRESSURE HOLDS OVER THE REGION. WILL LIKELY SEE SOME VARIABLE HIGH
CLOUDINESS BUT IT SHOULD NOT HAVE MUCH AFFECT ON TEMPS WHICH WILL
TOP OUT IN THE MID 60S TO NEAR 70 IN THE NORTH AND LOWER TO MID 70S
IN THE SOUTH.
SLOW MOVING AREA OF LOW PRESSURE OVER THE OHIO VALLEY WILL BRING
INCREASING CLOUDS TO THE REGION TUESDAY NIGHT AND WEDNESDAY.
INCREASINGLY MOIST ONSHORE FLOW WILL BRING OCEAN STRATUS INTO
SOUTHERN NEW ENGLAND DURING THE DAY TUESDAY AND THIS WILL GRADUALLY
LIFT NORTHWARD TUESDAY NIGHT AND WEDNESDAY. THIS WILL KEEP TEMPS UP
TUESDAY NIGHT BUT WILL HOLD READINGS DOWN ON WEDNESDAY...ESPECIALLY
IN SOUTHERN ZONES. IN ADDITION WILL BE GOING WITH LOW CHANCE POPS FOR
SCATTERED SHOWERS LATE TUESDAY NIGHT IN SOUTHWEST ZONES AND FOR THE
ENTIRE FORECAST AREA ON WEDNESDAY...BUT NOT EXPECTING MUCH AS
FORCING LIMITED AT BEST.
MORE CLOUDS AND SHOWERS WEDNESDAY NIGHT AS A COLD FRONT MOVES IN
FROM THE WEST. SHOWERS ASSOCIATED WITH THIS SYSTEM WILL PUSH EAST OF
THE FORECAST AREA AFTER MIDNIGHT BUT ABUNDANT LOW LEVEL MOISTURE
WILL LINGER BEHIND THE FRONT AND IT WILL LIKELY TAKE MUCH OF THE
DAY THURSDAY TO PRODUCE A FEW SUNNY BREAKS IN AREAS DOWNWIND OF
THE MOUNTAINS.
QUICK SHOT OF UPPER LEVEL RIDGING THURSDAY NIGHT AND FRIDAY BUT LOW
LEVEL MOISTURE WILL AGAIN KEEP SKIES MOSTLY CLOUDY THURSDAY NIGHT
INTO FRIDAY WITH SOME SUNNY BREAKS DEVELOPING MAINLY IN INLAND
LOCATIONS FRIDAY AFTERNOON.
COLD FRONT APPROACHING FROM THE WEST FRIDAY AFTERNOON WILL QUICKLY
BLOW THROUGH THE REGION FRIDAY NIGHT WITH A BRIEF ROUND OF SHOWERS
AND POSSIBLY A RUMBLE OF THUNDER. WILL SEE CLEARING SKIES DOWNWIND
OF THE MOUNTAINS BY SATURDAY MORNING AS A WEAK SURFACE RIDGE BUILDS
IN BEHIND THE FRONT. FAIR AMOUNT OF COLD AIR POISED TO THE NORTHWEST
SATURDAY MORNING SO WILL LIKELY SEE DAYTIME HIGHS PEAK DURING THE
LATE MORNING BEFORE DROPPING OFF IN THE AFTERNOON. HIGH PRESSURE
WILL HOLD OVER THE REGION ON SUNDAY WITH TEMPS AVERAGING OUT BELOW
NORMAL AFTER A CHILLY START TO THE DAY.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
SHORT TERM...OCCASIONAL MVFR TO IFR CONDITIONS IN SHOWERS AND
PATCHY FOG AND LOW CLOUDS OVERNIGHT. HOWEVER...WE THINK THE TREND
WILL BE TO IMPROVE AFTER MIDNIGHT. MVFR IN SHOWERS ON MONDAY IN
THE MORNING...THEN IMPROVEMENT TO VFR IN THE AFTERNOON EXCEPT THE
MOUNTAINS.
LONG TERM...VFR TUESDAY. MVFR/IFR CEILINGS DEVELOPING LATE TUESDAY
NIGHT AND WEDNESDAY AND PERSISTING THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...SCA FOR LATE TONIGHT AND MONDAY FOR THE OCEAN WATERS
FOR G25KT AND SEAS AOA 5 FT. SEAS WILL TAKE A WHILE TO
SUBSIDE...PROBABLY NOT UNTIL SOMETIME MONDAY NIGHT.
LONG TERM...NO PROBLEMS NOTED.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 8 PM EDT MONDAY
FOR ANZ150-152-154.
&&
$$
LEGRO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
331 PM EDT SAT SEP 29 2012
.SYNOPSIS...
ISSUED AT 316 PM EDT SAT SEP 29 2012
ONE AREA OF LOW PRESSURE WILL DEVELOP OVER NEW ENGLAND TONIGHT AND
SUNDAY. THIS SYSTEM WILL BE TO FAR EAST TO CREATE RAIN HERE IN
WESTERN MICHIGAN. HIGH PRESSURE IN ONTARIO WILL BUILD SOUTH
INTO WESTERN LOWER MICHIGAN CREATING FAIR CONDITIONS WITH COOL
NIGHTS AND NEAR SEASONABLY WARM DAYS INTO MONDAY. A WEAK COLD FRONT
WILL APPROACH THE REGION FROM THE NORTHWEST TUESDAY INTO WEDNESDAY
AS A LOW PRESSURE SYSTEM LIFTS OUT OF THE GULF OF MEXICO. AS A
RESULT THE REGION MAY SEE SOME SHOWERS ARRIVING.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 316 PM EDT SAT SEP 29 2012
THE MAIN CHALLENGE DEALS WITH THE RISK FOR FROST TONIGHT. OVERALL
THE TREND OF TRACKING/FORMING THE SURFACE LOW FURTHER EAST
CONTINUES. LOOKS LIKE IT WILL END UP OVER NEW ENGLAND. HERE IN WRN
LOWER MI...SKIES WILL FEATURE MUCH LESS CLOUD COVER AS A RESULT IT
APPEARS. THIS OPENS UP THE RISK FOR FROST ESPECIALLY WITH HIGH
PRESSURE NOW SHOWN TO DROP SOUTHWARD OUT OF ONTARIO. HOWEVER THE
HRRR RUC AND EVEN THE NAM ARE SHOWING LOW LEVEL MOISTURE AND A
RISK FOR STRATUS TO DEVELOP OVER NORTHEAST LOWER TONIGHT...THEN
DROP SOUTHWEST AND EXPAND INTO SOUTHWEST LOWER MI LATE TONIGHT.
WILL KEEP THE FROST OUT OF THE FORECAST FOR NOW...BUT THIS SHOULD
BE MONITORED CLOSELY AS HEADLINES MAY BE REQUIRED IF THE CLOUDS DO
NOT DEVELOP.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 316 PM EDT SAT SEP 29 2012
TEMPS WILL AVERAGE ABOVE NORMAL TUESDAY BUT SOME CLOUDS FROM LOW
PRESSURE TRACKING NE THROUGH THE OH VALLEY REGION WILL MOVE IN. WE
HAVE INTRODUCED MENTION OF A SLIGHT CHC OF LIGHT RAIN SHOWERS FROM
TUESDAY AFTERNOON THROUGH TUESDAY NIGHT INTO WEDNESDAY IN
ASSOCIATION WITH THAT SYSTEM (MAINLY SE OF GRR).
TEMPS WILL REMAIN ABOVE NORMAL WEDNESDAY THROUGH THURSDAY AFTERNOON
AS FLOW BECOMES SOUTHWESTERLY IN ADVANCE OF A STRONG COLD FRONT.
THAT LOW PRESSURE SYSTEM AND COLD FRONT WILL BRING A CHC OF SHOWERS
THURSDAY NIGHT THROUGH FRIDAY. AN UNSEASONABLY COOL AIRMASS WILL
MOVE IN BEHIND THAT FRONT FRIDAY THROUGH SATURDAY WHEN HIGH TEMPS
WILL ONLY REACH THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1200 PM EDT SAT SEP 29 2012
VFR CONDITIONS ARE EXPECTED THROUGH 18Z SUNDAY. LINGERING MID TO
HIGH LEVEL CLOUDS ARE QUICKLY DRIFTING SOUTH AND OUT OF THE AREA AND
A DRY AIRMASS IS MOVING IN. NW WINDS TO NEAR 10 KTS THIS AFTN WILL
DIMINISH TO 5 KTS OR LESS THIS EVENING AND VEER TO THE NE. NE WINDS
OF 5 TO 10 KTS ARE ANTICIPATED TOMORROW.
&&
.MARINE...
ISSUED AT 316 PM EDT SAT SEP 29 2012
WAVES WILL BE BUILDING AN REACH VALUES CLOSE TO SMALL CRAFT
ADVISORY CRITERIA TONIGHT UP AROUND LITTLE AND BIG SABLE POINTS.
THEN ON SUNDAY AS A NORTHERLY FLOW PERSISTS...WAVES SOUTH OF SOUTH
HAVEN WILL ALSO END UP CLOSE TO CRITERIA. I THOUGHT MOST VALUES
WOULD BE JUST UNDER CRITERIA SO NO HEADLINE AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 316 PM EDT SAT SEP 29 2012
NO HYDRO ISSUES EXPECTED. ANY RAINFALL IS FORECASTED TO BE LIMITED
AND NOT ENOUGH TO CAUSE SIGNIFICANT RISES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS DULUTH MN
818 PM CDT SUN SEP 30 2012
.AVIATION.../00Z TAF ISSUANCE/
VFR CONDITIONS ARE EXPECTED DURING THE TAF PERIOD. A COLD FRONT
WILL MOVE THROUGH THE REGION ON MONDAY...SWITCHING WINDS FROM A
SOUTHERLY DIRECTION TO THE NORTHWEST. A FEW SPRINKLES OR SHOWERS
ARE POSSIBLE BUT THE FRONT SHOULD GENERALLY MOVE THROUGH DRY.
&&
.PREV DISCUSSION... /ISSUED 316 PM CDT SUN SEP 30 2012/
SHORT TERM...SFC HIGH HAD DRIFTED OVER NORTHERN LAKE SUPERIOR AS
OF 20Z WITH DRY AIR ENTRENCHED OVER THE FA. SFC WIND WAS TURNING
FROM THE SE TO THE S AHEAD OF AN APPROACHING A COLD FRONT. THIS
FRONT IS EXPECTED TO MOVE THROUGH NORTHEAST MINNESOTA BY MIDNIGHT
AND NW WI BY 12Z MONDAY. EXPECT THIS TO BE A DRY FROPA WHICH IS
SUPPORTED BY FORECAST SOUNDINGS FROM ALL MODELS WHICH ARE DRY
BELOW 10K FT. HAVE ADDED A MENTION OF PATCHY FOG TO THE NEAR
SHORE WATERS FROM TWO HARBORS TO THE TWIN PORTS AND PORT WING WI
AS WELL AS INLAND TO SUW WHICH THE LATEST HI RES MODELS HRRR AND
NARRE AGREE ON THIS DEVELOPMENT.
BEHIND THE FRONT LATER TONIGHT AND MONDAY A NW WIND IS EXPECTED
AND IT WILL HELP USHER IN COOLER AIR. HOWEVER...WITH PLENTY OF SUN
EXPECTED...LOOK FOR MAX TEMPS IN THE 60S TO NEAR 70 NEAR PBH AND
BRD.
THE SFC RIDGE AXIS OVERLAYS THE FA MONDAY NIGHT AND EXPECT
RADIATIONAL COOLING WITH A CLEARING SKY TO PRODUCE MIN TEMPS IN
THE 30S...TO AROUND 45 NEAR PBH. THE WARMER TEMPS NEAR PBH ARE DUE
TO LINGERING CLOUDS.
LONG TERM...[TUESDAY - SATURDAY]...
SNOW IS APPEARING MORE AND MORE LIKELY FOR LATER THIS WEEK. THE
EXPECTED TREND IS FOR WARMER THAN NORMAL WEATHER ON TUESDAY AND
WEDNESDAY TO COME TO AN END BY THURSDAY WHEN A LOW PRESSURE SYSTEM
MOVES ACROSS SOUTHERN MINNESOTA AND NORTHERN WISCONSIN WEDNESDAY
NIGHT AND THURSDAY. THE SYSTEM...WHICH THE GFS AND ECMWF ARE IN
PRETTY GOOD AGREEMENT WITH...WILL USHER IN RAIN AND MUCH COLDER
WEATHER FOR THURSDAY. THE PCPN COULD TRANSITION TO SNOW OR A
RAIN/SNOW MIXTURE THURSDAY NIGHT. PERIODS OF RAIN AND SNOW COULD
CONTINUE INTO THE WEEKEND AS THE COLD WEATHER STICKS AROUND IN THE
WAKE OF THE SYSTEM. IT IS UNCLEAR AT THIS POINT WHETHER THE SNOW
WILL HAPPEN...BUT IT IS LOOKING MORE AND MORE LIKELY...ESPECIALLY
FOR THURSDAY NIGHT AND FRIDAY NIGHT. DO NOT WANT TO MAKE ANY GUESSES
ABOUT ACCUMULATION AT THIS POINT SINCE THE SYSTEM IS STILL FAR OUT.
AT THIS POINT...DID NOT FORECAST ANY PERIODS OF PURE SNOW...BUT SOME
PERIODS OF A RAIN/SNOW MIXTURE.
AVIATION.../18Z TAF ISSUANCE/
VFR CONDITIONS WILL LIKELY CONTINUE ACROSS NE MINNESOTA AND NW
WISCONSIN THROUGH MONDAY MORNING. THE LIGHT SOUTHERLY WINDS WILL
SWITCH TO NORTHWESTERLY TONIGHT WITH THE PASSAGE OF A COLD
FRONT...AND THE WINDS WILL INCREASE LATE TOMORROW MORNING. THERE
MAY BE FOG SOUTH OF KDLH...BUT AT THIS TIME...DO NOT THINK IT WILL
AFFECT THE TERMINAL. THERE MAY BE ISOLATED LIGHT RAIN SHOWERS
TOMORROW MORNING NEAR KDLH AND KHIB.
&&
.POINT TEMPS/POPS...
DLH 45 65 39 63 / 10 10 0 0
INL 46 64 33 66 / 10 10 0 0
BRD 51 68 35 70 / 10 10 0 0
HYR 43 66 39 68 / 10 10 10 0
ASX 44 67 39 64 / 10 10 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1012 PM CDT SUN SEP 30 2012
.UPDATE...KUEX INDICATES ANY LINGERING CONVECTION ACROSS THE
REGION HAS FINALLY PUSHED OUT OF OUR CWA. LOSS OF DIABATIC HEATING
SHOULD PREVENT ANY ADDITIONAL CONVECTIVE ACTIVITY FROM BEING
REALIZED THROUGH AT LEAST 06Z. BEYOND 06Z HOWEVER...A MID LEVEL
TROUGH AXIS...CURRENTLY OVER THE NORTHERN PLAINS...WILL PUSH
EAST/SOUTHEAST WITH PERHAPS ENOUGH MID LEVEL THERMAL ADVECTION AND
DPVA FOR ADDITIONAL PRECIPITATION PRODUCTION OVER OUR AREA.
ALSO...EVENING UPPER AIR ANALYSIS INDICATES A ~100KT UPPER LEVEL
JET STREAK OVER MONTANA AND WYOMING. THIS UPPER LEVEL JET STREAK
IS EXPECTED TO MOVE SOUTHEAST TONIGHT...WITH THE LEFT-FRONT
QUADRANT OF THIS JET STREAK PERHAPS PROVIDING ENOUGH OF AN
INDIRECT THERMAL CIRCULATION THUS ALSO ENHANCING CHANCES FOR
PRECIPITATION AFTER 06Z. QPF FIELDS FROM THE NAM...OPERATIONAL
GFS...EC AND SREF-MEAN ALL ALSO SUGGEST LIGHT PRECIPITATION WILL
BE REALIZED OVER OUR WEST/NORTHWESTERN CWA AND AS A RESULT OF ALL
THIS...WENT AHEAD CONTINUED CARRYING 20% ACROSS OUR WEST/NORTHWEST
06Z-12Z. INCREASING MID LEVEL LAPSE RATES WITH THE APPROACH OF MID
LEVEL TROUGH AXIS WILL PROMOTE AT LEAST MODEST POTENTIAL
INSTABILITY...WITH THE NAM AND OPERATIONAL GFS BOTH SUGGESTING
DEEP LAYER MUCAPE VALUES OF ~50J/KG OVER THE AREA TONIGHT. GIVEN
ALL THIS...CERTAINLY DO NOT ANTICIPATE MUCH CONVECTION BUT AN
ISOLATED THUNDERSTORM OR TWO CANNOT BE RULED OUT AND WILL CONTINUE
CARRYING THUNDER MENTION IN THE FORECAST OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 614 PM CDT SUN SEP 30 2012/
AVIATION...00Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT KGRI
THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL BE
POSSIBLE AT THE TERMINAL...BUT NOTHING BELOW 10000FT AGL ARE
CURRENTLY FORECAST. THERE IS AN OUTSIDE CHANCE THAT MEASURABLE
RAINFALL COULD BE OBSERVED AT KGRI...PRIMARILY BETWEEN SUNRISE AND
LATE MORNING MONDAY...BUT AT THIS TIME THE CHANCES OF
PRECIPITATION BEING REALIZED AT KGRI ARE TOO LOW FOR INSERTION
INTO THE TAF. THE SURFACE WIND WILL REMAIN LIGHT AND VARIABLE
THROUGH 09Z BEFORE BECOMING MORE ESTABLISHED FROM THE
NORTH/NORTHWEST. A STRONG NORTH/NORTHWESTERLY SURFACE WIND WILL BE
REALIZED AT THE TERMINAL ON MONDAY...SUSTAINED NEAR 22KTS AND
GUSTING TO NEAR 29KTS. VISIBILITY RESTRICTIONS ARE NOT EXPECTED AT
KGRI THROUGH THE NEXT 24 HOURS.
PREV DISCUSSION... /ISSUED 356 PM CDT SUN SEP 30 2012/
SHORT TERM...THROUGH LATE MONDAY AFTERNOON. THERE ARE TWO PRIMARY
ISSUES AT HAND DURING THE NEXT 24 HOURS...THE FIRST BEING A
POSSIBLE BUT STILL FAIRLY UNCERTAIN RISK FOR A FEW STRONG
THUNDERSTORMS ACROSS THE FAR WESTERN CWA LATE THIS AFTERNOON INTO
THIS EVENING...AND THE SECOND MAIN ISSUE BEING ELEVATED TO NEAR-
CRITICAL FIRE DANGER ON MONDAY AFTERNOON. ALSO OF CONCERN IS
TRYING TO FIGURE OUT HOW MUCH POST-FRONTAL RAIN WILL DEVELOP
MAINLY DURING THE MORNING HOURS MONDAY. FOR ALL FIRE WEATHER
DISCUSSION PLEASE SEE THE SEPARATE SECTION BELOW.
20Z OBJECTIVE SURFACE ANALYSIS INDICATES A NORTH-SOUTH TROUGH AXIS
EXTENDING FROM NORTH CENTRAL NEB TO NORTHWEST KS...SEPARATING A
LIGHT/VARIABLE TO LIGHT/SOUTHERLY WIND REGIME TO THE EAST FROM A
STRONGER NORTHERLY COMPONENT TO THE WEST. WITHIN AND NEAR THE
IMMEDIATE TROUGH AXIS...INCLUDING MAINLY THE WESTERN 1/4 OF THE
CWA...SURFACE DEWPOINTS HAVE INCREASED TODAY BETWEEN THE MID 40S
AND MID 50S...AND THERE ARE EVEN NOW SIGNS OF A LOW LEVEL CUMULUS
FIELD STARTING TO SHOW ITS HAND. MEANWHILE...ACROSS THE MAJORITY
OF THE CENTRAL/EASTERN CWA...DEWPOINTS HAVE AGAIN DONE THEIR
SEEMINGLY DAILY CRASH WELL INTO THE 30S IN MOST AREAS...ONCE AGAIN
BELOW FORECAST VALUES. ACTUAL HIGH TEMPS ARE WORKING OUT PRETTY
WELL...WITH NEARLY ALL AREAS WITHIN A FEW DEGREES OF 80. OTHER
THAN THE NEWLY DEVELOPED CUMULUS FIELD IN PARTS OF THE
WEST...VISIBLE SATELLITE SHOWS THAT MOST OF THE THICKER HIGH
CIRRUS FROM EARLIER TODAY HAS VACATED EAST OF THE CWA...WHILE A
FEW LEGITIMATE SHOWERS/NEWLY DEVELOPED THUNDERSTORMS ARE ALREADY
OCCURRING BOTH SOUTHWEST AND NORTHWEST OF THE CWA IN NORTH CENTRAL
NEB AND NORTHWEST KS. WATER VAPOR SATELLITE IMAGERY AND SHORT TERM
MODEL DATA DEPICTS AN ALMOST DUE NORTHERLY MID LEVEL FLOW OVER THE
CWA...WITH THE PRIMARY SYNOPTIC SCALE LOWS CONSISTING OF A DEEP
CLOSED CIRCULATION OVER THE NORTHEAST STATES...A VERY SLOW MOVING
CLOSED MID LEVEL LOW CENTERED OVER EASTERN OK...AND A PROGRESSIVE
OPEN WAVE AND ASSOCIATED UPPER LEVEL JET STREAK DIPPING OUT OF
SOUTHERN CANADA INTO THE MT/ND/SD REGION.
STARTING WITH THE MOST IMMEDIATE ISSUE OVER THE NEXT 6 HOURS OR
SO...HAVE MAINTAINED 20-30 PERCENT SHOWER/STORM CHANCES LATE THIS
AFTERNOON INTO THIS EVENING FOR AREAS PRIMARILY WEST OF AN ORD-
KEARNEY-PLAINVILLE LINE AND ESPECIALLY DAWSON...GOSPER AND FURNAS
COUNTIES WHICH ARE ABOUT THE ONLY PARTS OF THE CWA WITHIN THE
MOIST AXIS AND RESULTANT INSTABILITY AXIS...WITH 20Z MESOSCALE
ANALYSIS SUGGESTING THAT A NARROW CORRIDOR OF MLCAPE AT LEAST INTO
THE 500-1000 J/KG RANGE IS NOW IN PLACE IN THIS AREA.
MEANWHILE...THE EASTERN HALF TO TWO THIRDS OF THE CWA HAS
ESSENTIALLY NO CONVECTIVE INSTABILITY AT THIS HOUR...AND THIS WILL
NOT CHANGE HEADING INTO THE EVENING HOURS. WITH DEEP LAYER 0-6KM
BULK SHEAR ONLY AVERAGING AROUND 20 KT...AM NOT EXPECTING A
LEGITIMATE SEVERE THREAT WITH THIS EVENT...BUT THERE IS MORE THAN
ENOUGH INSTABILITY TO GET SOME SEMI-ORGANIZED MULTICELL STORMS OR
A FEW QUASI-LINEAR CLUSTERS GOING...WITH SMALL HAIL AND WINDS TO
AROUND 50 MPH VERY POSSIBLE. FOLLOWING THE REFLECTIVITY PROGS OF
THE LATEST HRRR AND ALSO 12Z 4KM-WRF NMM...THERE COULD BE A DECENT
LULL IN SHOWER/STORM ACTIVITY ONCE THE MID EVENING HOURS ARRIVE
AND THE LOW LEVELS START TO STABILIZE A BIT. FOR THE LATE NIGHT
06Z-12Z POP/WEATHER GRIDS...OPTED TO BLANKET A 20 PERCENT CHANCE
OF SHOWERS/ISOLATED THUNDER ACROSS ROUGHLY THE NORTHWEST 2/3 OF
THE CWA INCLUDING THE TRI-CITIES...IN ASSOCIATION WITH INCREASING
SYNOPTIC SCALE FORCING AND A RESULTANT SOUTHWEST-NORTHEAST BAND OF
MID LEVEL SATURATION DEVELOPING AHEAD OF THE PARENT SHORTWAVE
DROPPING SOUTHEAST ACROSS THE DAKOTAS. THERE ARE PLENTY OF
QUESTIONS REGARDING HOW WIDESPREAD THIS LATE NIGHT PRECIPITATION
MIGHT BE...WITH BOTH THE LATEST ECMWF/GFS SUGGESTING IT COULD BE
NARROW BUT FAIRLY SOLID BAND OF MEASURABLE RAIN...WHILE THE NAM IS
MUCH DRIER THROUGH SUNRISE ALONG WITH THE 4KM WRF-NMM. AT ANY
RATE...NOT EXPECTING ANY LATE NIGHT STORMS TO BE ALL THAT STRONG
LET ALONE SEVERE. KEPT LOW TEMPS TONIGHT SIMILAR TO PREVIOUS
FORECAST AND MET/MAV GUIDANCE BLEND...GENERALLY RIGHT AROUND 50.
FOR THE MONDAY DAYTIME HOURS...BY SUNRISE A WELL DEFINED SURFACE
COLD FRONT WILL BE IN THE PROCESS OF CROSSING THROUGH THE
CWA...AND REALLY THE MOST PROMINENT WEATHER FEATURE THROUGH THE
DAY WILL BE THE QUITE BREEZY TO WINDY CONDITIONS IN ITS WAKE...AS
NORTH WINDS AVERAGE 20-25 MPH SUSTAINED THROUGH MOST OF THE DAY
AND GUSTS 30-35 MPH...BUT SHOULD AVERAGE AT LEAST 5 MPH SHORT OF
ADVISORY CRITERIA. AS FOR PRECIP CHANCES DURING THE DAY...AM
STARTING TO WONDER IF THE FORECAST 20 PERCENT CHANCE OF SHOWERS
DURING THE MORNING HOURS ACROSS ROUGHLY THE SOUTHEAST 2/3 OF THE
CWA IS HIGH ENOUGH...AS THE LATEST ECMWF/GFS ARE NOW SHOWING
POTENTIAL FOR A MORE ORGANIZED NARROW BAND OF LIGHT BUT MEASURABLE
RAINFALL PASSING THROUGH FROM NORTHWEST TO SOUTHEAST.
HOWEVER...WITH MOST OF THE SATURATION ABOVE 700MB AM HESITANT TO
GET TOO CARRIED AWAY WITH POPS...ESPECIALLY GIVEN THAT BOTH THE
18Z NAM AND 12Z WRF-NMM SHOW A MUCH MORE HIT AND MISS...LESS
ORGANIZED BAND. STAYED WITH THE THEME FROM PREVIOUS FORECAST...AND
LEFT THIS MORNING PRECIP RISK AS JUST SHOWERS WITH NO THUNDER
MENTION...ALTHOUGH SUPPOSE A FEW ROGUE LIGHTNING STRIKES ARE NOT
OUT OF THE QUESTION. ALSO IN LINE WITH PREVIOUS FORECAST...LEFT
THE AFTERNOON 18Z-00Z PERIOD PRECIP FREE...BUT THERE A FEW HINTS
IN LATEST MODELS THAT A FEW SHOWERS COULD LINGER INTO THE
AFTERNOON PERIOD ACROSS THE FAR EASTERN/SOUTHERN CWA...AND THE
NEXT SHIFTS WILL WANT TO SEE IF MAYBE THIS RAIN MENTION NEEDS
EXTENDED IN TIME A BIT. BY THE MID AFTERNOON HOURS
HOWEVER...CONFIDENCE IS FAIRLY HIGH THAT THE ENTIRE CWA SHOULD BE
RAIN-FREE AND SEEING PLENTY OF SUN...AS THE PARENT MID LEVEL
TROUGH AXIS AND RESULTANT MID LEVEL SATURATION STARTS TO FOCUS
EAST OF THE AREA. TEMP WISE...LOWERED HIGHS 2-3 DEGREES FROM
PREVIOUS IN MOST AREAS...FOLLOWING THE RAW 12Z NAM SOLUTION
CLOSELY AND RANGING FROM LOW 70S NORTHWEST TO UPPER 70S SOUTHEAST.
DID LOWER DEWPOINTS SEVERAL DEGREES ESPECIALLY DURING THE MID-LATE
AFTERNOON WITH WIDESPREAD LOW-MID 30S AND EVEN UPPER 20S
NORTHWEST.
LONG TERM...MONDAY NIGHT THROUGH SUNDAY. SURFACE HIGH PRESSURE
BUILDS SOUTH BEHIND THE COLD FRONTAL BOUNDARY...WITH RIDGE AXIS
SETTLING ACROSS NEBRASKA AND WESTERN KANSAS MONDAY NIGHT. THE
RIDGE DOES WEAKEN...HOWEVER IN THE COOLER...DRY AIRMASS WITH LIGHT
WINDS AND GOOD RADIATIONAL CONDITIONS...WE ARE LOOKING AT THE
POTENTIAL FOR SOME CHILLY OVERNIGHT LOW TEMPERATURES. SFC DPS DROP
TO THE 20S AND LOWER 30S AND ITS LOOKING LIKE OVERNIGHT LOWS WILL
AGAIN FALL INTO THE TEMPERATURE RANGE FAVORABLE FOR FROST...IN THE
LOW/MID 30S. THESE LOCATIONS HAVE ALREADY EXPERIENCED SIMILAR LOW
TEMPS THIS SEASON OR COLDER AND WILL NOT MENTION FROST...BUT WILL
NEED TO MONITOR FOR FREEZE CONDITIONS FOR LOCATIONS THAT HAVE YET
TO FREEZE.
THE SURFACE RIDGE AXIS WASHES OUT/SHIFTS EAST ON TUESDAY WITH
RETURN FLOW SETTING UP AHEAD OF A DEEPENING SURFACE LOW IN
MANITOBA...ASSOCIATED WITH UPSTREAM TROUGH ALONG THE US/CANADIAN
BORDER. SHORTWAVE RIDGING NOSES ONTO THE CENTRAL PLAINS IN BETWEEN
UPPER LOW TO THE SOUTHEAST AND TROUGH ENTERING THE NORTHERN
ROCKIES. TEMPERATURES WILL MODERATE TUESDAY...BUT WITH COOL START
TO THE DAY AND LESS MIXING WILL AIM FOR HIGHS IN THE MID 70S VS
NEAR 80F.
WEDNESDAY IS REALLY ONE OF THE TRICKIER DAYS DUE TO TIMING OF COLD
FRONTAL PASSAGE. UPPER LOW PRESSURE TROUGH REACHES THE NORTHERN
PLAINS AND ROCKIES WITH THE ASSOCIATED COLD FRONT MOVING INTO
WESTERN NEBRASKA BY 12Z WEDNESDAY. THERE ARE IMPRESSIVE PRESSURE
RISES OF 10+MB PROGGED BEHIND THE FRONT IN THE NEB PANHANDLE. IN
GENERAL MODELS HAVE TRENDED FASTER WITH FRONTAL PASSAGE WITH THE
BOUNDARY THROUGH AT LEAST OUR WESTERN THIRD CWA...IF NOT HALF OF
THE CWA BY 18Z. WITH THE FASTER TREND...HAVE SHARPENED TEMP
GRADIENT NW/SE WITH AND LOWERED HIGHS IN OUR NORTHWEST TO THE LOW
70S. IF FRONT TRENDS ANY FASTER...COULD SEE TEMPS FALLING DURING
THE AFTERNOON AND OUR NW ZONES MAY NOT REACH 70F. THIS BEING
SAID...IF FRONT IS SLOWER AND MORE IN LINE WITH ECMWF VS
NAM/GFS...TEMPS MAY BE WARMER THAN CURRENT FORECAST.
PCPN CHCS INCREASE WEDNESDAY NIGHT IN INCREASING UPPER DYNAMICS AS
TROUGH CROSSES THE CENTRAL PLAINS. THE 12Z GFS AND GEM ARE DEEPER
WITH TROUGH THAN THE MORE PROGRESSIVE 00Z AND 12Z RUNS OF THE
ECMWF. HAVE CONCERNS THAT ECMWF IS TOO PROGRESSIVE WITH
SYSTEM...AND GFS/GFS ENSEMBLE LOOKS TO BE DECENT COMPROMISE
BETWEEN ECMWF AND GEM SOLUTIONS. IF THE DEEPER TROUGH SOLUTIONS
VERIFY WE COULD SEE A DECENT CHC FOR RAIN...BUT WOULD LIKE TO SEE
MORE CONSISTENCY BEFORE RAISING POPS. THE TROUGH AXIS DEPARTS
THURSDAY MORNING...WITH PCPN ENDING W/E.
THEREAFTER FOR THE REMAINDER OF THE WORKWEEK AND INTO NEXT
WEEKEND...PATTERN WILL BE INFLUENCED BY UPPER TROUGH ENCOMPASSING
MUCH OF THE INTERIOR CONUS. TEMPERATURES WILL REMAIN BELOW NORMAL
AND THERE WILL BE SOME HIT OR MISS CHCS FOR RAIN SHOWERS AS ENERGY
TRANSLATES THRU FLOW.
FIRE WEATHER...ALTHOUGH FIRE WEATHER CONDITIONS ARE CURRENTLY
FORECAST TO FALL JUST A BIT SHORT OF CRITICAL THRESHOLDS ON MONDAY
AFTERNOON THANKS TO RELATIVE HUMIDITY VALUES HOLDING AT LEAST
SLIGHTLY ABOVE 20 PERCENT...THE CURRENTLY FORECAST COMBINATION OF
SUSTAINED NORTHERLY WINDS AROUND 25 MPH/GUSTS 30-35 MPH AND
RELATIVE HUMIDITY VALUES FALLING INTO THE 22-26 PERCENT RANGE FOR
A FEW HOURS IS MORE THAN ENOUGH TO WARRANT THE CONTINUATION OF
ELEVATED TO NEAR-CRITICAL FIRE DANGER WORDING IN THE HAZARDOUS
WEATHER OUTLOOK. BASED ON RAINFALL TRENDS OVER THE PAST MONTH AND
OFFICIAL FIRE GROWTH FUEL STATUS FROM FIRE MANAGERS...THE NEBRASKA
COUNTIES WILL GENERALLY BE UNDER THE GUN MORE SO THAN KS. ONE
FACTOR THAT MIGHT BE JUST ENOUGH TO SPARE US FROM DROPPING TO 20
PERCENT OR LOWER RELATIVE HUMIDITY IS THAT HIGH TEMPS WERE LOWERED
2-3 DEGREES FROM PREVIOUS FORECAST. HOWEVER...DEWPOINTS WERE ALSO
DROPPED AT LEAST 5 DEGREES FROM PREVIOUS FORECAST IN MOST AREAS
DURING THE KEY MID-LATE AFTERNOON HOURS...NOW ADVERTISED BETWEEN
THE UPPER 20S AND MID 30S IN MOST COUNTIES. NEXT FEW SHIFTS WILL
HAVE TO KEEP A CLOSE EYE ON THESE DEWPOINT/RH TRENDS...AS ONLY A
SLIGHT DOWNWARD ADJUSTMENT COULD REQUIRE HEADLINE ISSUANCE FOR AT
LEAST A SMALL PART OF MAINLY THE WESTERN CWA. LOOKING BEYOND
MONDAY...WILL ALSO HAVE TO KEEP AN EYE ON WEDNESDAY AFTERNOON FOR
OUR NEXT POTENTIALLY NEAR-CRITICAL FIRE DANGER SITUATION...AS
NORTHERLY WINDS INCREASE AGAIN BEHIND THE NEXT COLD FRONT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/AVIATION...BRYANT
SHORT TERM/FIRE WEATHER...PFANNKUCH
LONG TERM...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
614 PM CDT SUN SEP 30 2012
.AVIATION...00Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT KGRI
THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL BE
POSSIBLE AT THE TERMINAL...BUT NOTHING BELOW 10000FT AGL ARE
CURRENTLY FORECAST. THERE IS AN OUTSIDE CHANCE THAT MEASURABLE
RAINFALL COULD BE OBSERVED AT KGRI...PRIMARILY BETWEEN SUNRISE AND
LATE MORNING MONDAY...BUT AT THIS TIME THE CHANCES OF
PRECIPITATION BEING REALIZED AT KGRI ARE TOO LOW FOR INSERTION
INTO THE TAF. THE SURFACE WIND WILL REMAIN LIGHT AND VARIABLE
THROUGH 09Z BEFORE BECOMING MORE ESTABLISHED FROM THE
NORTH/NORTHWEST. A STRONG NORTH/NORTHWESTERLY SURFACE WIND WILL BE
REALIZED AT THE TERMINAL ON MONDAY...SUSTAINED NEAR 22KTS AND
GUSTING TO NEAR 29KTS. VISIBILITY RESTRICTIONS ARE NOT EXPECTED AT
KGRI THROUGH THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 356 PM CDT SUN SEP 30 2012/
SHORT TERM...THROUGH LATE MONDAY AFTERNOON. THERE ARE TWO
PRIMARY ISSUES AT HAND DURING THE NEXT 24 HOURS...THE FIRST BEING
A POSSIBLE BUT STILL FAIRLY UNCERTAIN RISK FOR A FEW STRONG
THUNDERSTORMS ACROSS THE FAR WESTERN CWA LATE THIS AFTERNOON INTO
THIS EVENING...AND THE SECOND MAIN ISSUE BEING ELEVATED TO NEAR-
CRITICAL FIRE DANGER ON MONDAY AFTERNOON. ALSO OF CONCERN IS
TRYING TO FIGURE OUT HOW MUCH POST-FRONTAL RAIN WILL DEVELOP
MAINLY DURING THE MORNING HOURS MONDAY. FOR ALL FIRE WEATHER
DISCUSSION PLEASE SEE THE SEPARATE SECTION BELOW.
20Z OBJECTIVE SURFACE ANALYSIS INDICATES A NORTH-SOUTH TROUGH AXIS
EXTENDING FROM NORTH CENTRAL NEB TO NORTHWEST KS...SEPARATING A
LIGHT/VARIABLE TO LIGHT/SOUTHERLY WIND REGIME TO THE EAST FROM A
STRONGER NORTHERLY COMPONENT TO THE WEST. WITHIN AND NEAR THE
IMMEDIATE TROUGH AXIS...INCLUDING MAINLY THE WESTERN 1/4 OF THE
CWA...SURFACE DEWPOINTS HAVE INCREASED TODAY BETWEEN THE MID 40S
AND MID 50S...AND THERE ARE EVEN NOW SIGNS OF A LOW LEVEL CUMULUS
FIELD STARTING TO SHOW ITS HAND. MEANWHILE...ACROSS THE MAJORITY
OF THE CENTRAL/EASTERN CWA...DEWPOINTS HAVE AGAIN DONE THEIR
SEEMINGLY DAILY CRASH WELL INTO THE 30S IN MOST AREAS...ONCE
AGAIN BELOW FORECAST VALUES. ACTUAL HIGH TEMPS ARE WORKING OUT
PRETTY WELL...WITH NEARLY ALL AREAS WITHIN A FEW DEGREES OF 80.
OTHER THAN THE NEWLY DEVELOPED CUMULUS FIELD IN PARTS OF THE
WEST...VISIBLE SATELLITE SHOWS THAT MOST OF THE THICKER HIGH
CIRRUS FROM EARLIER TODAY HAS VACATED EAST OF THE CWA...WHILE A
FEW LEGITIMATE SHOWERS/NEWLY DEVELOPED THUNDERSTORMS ARE ALREADY
OCCURRING BOTH SOUTHWEST AND NORTHWEST OF THE CWA IN NORTH CENTRAL
NEB AND NORTHWEST KS. WATER VAPOR SATELLITE IMAGERY AND SHORT TERM
MODEL DATA DEPICTS AN ALMOST DUE NORTHERLY MID LEVEL FLOW OVER THE
CWA...WITH THE PRIMARY SYNOPTIC SCALE LOWS CONSISTING OF A DEEP
CLOSED CIRCULATION OVER THE NORTHEAST STATES...A VERY SLOW MOVING
CLOSED MID LEVEL LOW CENTERED OVER EASTERN OK...AND A PROGRESSIVE
OPEN WAVE AND ASSOCIATED UPPER LEVEL JET STREAK DIPPING OUT OF
SOUTHERN CANADA INTO THE MT/ND/SD REGION.
STARTING WITH THE MOST IMMEDIATE ISSUE OVER THE NEXT 6 HOURS OR
SO...HAVE MAINTAINED 20-30 PERCENT SHOWER/STORM CHANCES LATE THIS
AFTERNOON INTO THIS EVENING FOR AREAS PRIMARILY WEST OF AN ORD-
KEARNEY-PLAINVILLE LINE AND ESPECIALLY DAWSON...GOSPER AND FURNAS
COUNTIES WHICH ARE ABOUT THE ONLY PARTS OF THE CWA WITHIN THE
MOIST AXIS AND RESULTANT INSTABILITY AXIS...WITH 20Z MESOSCALE
ANALYSIS SUGGESTING THAT A NARROW CORRIDOR OF MLCAPE AT LEAST INTO
THE 500-1000 J/KG RANGE IS NOW IN PLACE IN THIS AREA.
MEANWHILE...THE EASTERN HALF TO TWO THIRDS OF THE CWA HAS
ESSENTIALLY NO CONVECTIVE INSTABILITY AT THIS HOUR...AND THIS WILL
NOT CHANGE HEADING INTO THE EVENING HOURS. WITH DEEP LAYER 0-6KM
BULK SHEAR ONLY AVERAGING AROUND 20 KT...AM NOT EXPECTING A
LEGITIMATE SEVERE THREAT WITH THIS EVENT...BUT THERE IS MORE THAN
ENOUGH INSTABILITY TO GET SOME SEMI-ORGANIZED MULTICELL STORMS OR
A FEW QUASI-LINEAR CLUSTERS GOING...WITH SMALL HAIL AND WINDS TO
AROUND 50 MPH VERY POSSIBLE. FOLLOWING THE REFLECTIVITY PROGS OF
THE LATEST HRRR AND ALSO 12Z 4KM-WRF NMM...THERE COULD BE A DECENT
LULL IN SHOWER/STORM ACTIVITY ONCE THE MID EVENING HOURS ARRIVE
AND THE LOW LEVELS START TO STABILIZE A BIT. FOR THE LATE NIGHT
06Z-12Z POP/WEATHER GRIDS...OPTED TO BLANKET A 20 PERCENT CHANCE
OF SHOWERS/ISOLATED THUNDER ACROSS ROUGHLY THE NORTHWEST 2/3 OF
THE CWA INCLUDING THE TRI-CITIES...IN ASSOCIATION WITH INCREASING
SYNOPTIC SCALE FORCING AND A RESULTANT SOUTHWEST-NORTHEAST BAND
OF MID LEVEL SATURATION DEVELOPING AHEAD OF THE PARENT SHORTWAVE
DROPPING SOUTHEAST ACROSS THE DAKOTAS. THERE ARE PLENTY OF
QUESTIONS REGARDING HOW WIDESPREAD THIS LATE NIGHT PRECIPITATION
MIGHT BE...WITH BOTH THE LATEST ECMWF/GFS SUGGESTING IT COULD BE
NARROW BUT FAIRLY SOLID BAND OF MEASURABLE RAIN...WHILE THE NAM IS
MUCH DRIER THROUGH SUNRISE ALONG WITH THE 4KM WRF-NMM. AT ANY
RATE...NOT EXPECTING ANY LATE NIGHT STORMS TO BE ALL THAT STRONG
LET ALONE SEVERE. KEPT LOW TEMPS TONIGHT SIMILAR TO PREVIOUS
FORECAST AND MET/MAV GUIDANCE BLEND...GENERALLY RIGHT AROUND 50.
FOR THE MONDAY DAYTIME HOURS...BY SUNRISE A WELL DEFINED SURFACE
COLD FRONT WILL BE IN THE PROCESS OF CROSSING THROUGH THE
CWA...AND REALLY THE MOST PROMINENT WEATHER FEATURE THROUGH THE
DAY WILL BE THE QUITE BREEZY TO WINDY CONDITIONS IN ITS WAKE...AS
NORTH WINDS AVERAGE 20-25 MPH SUSTAINED THROUGH MOST OF THE DAY
AND GUSTS 30-35 MPH...BUT SHOULD AVERAGE AT LEAST 5 MPH SHORT OF
ADVISORY CRITERIA. AS FOR PRECIP CHANCES DURING THE DAY...AM
STARTING TO WONDER IF THE FORECAST 20 PERCENT CHANCE OF SHOWERS
DURING THE MORNING HOURS ACROSS ROUGHLY THE SOUTHEAST 2/3 OF THE
CWA IS HIGH ENOUGH...AS THE LATEST ECMWF/GFS ARE NOW SHOWING
POTENTIAL FOR A MORE ORGANIZED NARROW BAND OF LIGHT BUT MEASURABLE
RAINFALL PASSING THROUGH FROM NORTHWEST TO SOUTHEAST.
HOWEVER...WITH MOST OF THE SATURATION ABOVE 700MB AM HESITANT TO
GET TOO CARRIED AWAY WITH POPS...ESPECIALLY GIVEN THAT BOTH THE
18Z NAM AND 12Z WRF-NMM SHOW A MUCH MORE HIT AND MISS...LESS
ORGANIZED BAND. STAYED WITH THE THEME FROM PREVIOUS FORECAST...AND
LEFT THIS MORNING PRECIP RISK AS JUST SHOWERS WITH NO THUNDER
MENTION...ALTHOUGH SUPPOSE A FEW ROGUE LIGHTNING STRIKES ARE NOT
OUT OF THE QUESTION. ALSO IN LINE WITH PREVIOUS FORECAST...LEFT
THE AFTERNOON 18Z-00Z PERIOD PRECIP FREE...BUT THERE A FEW HINTS
IN LATEST MODELS THAT A FEW SHOWERS COULD LINGER INTO THE
AFTERNOON PERIOD ACROSS THE FAR EASTERN/SOUTHERN CWA...AND THE
NEXT SHIFTS WILL WANT TO SEE IF MAYBE THIS RAIN MENTION NEEDS
EXTENDED IN TIME A BIT. BY THE MID AFTERNOON HOURS
HOWEVER...CONFIDENCE IS FAIRLY HIGH THAT THE ENTIRE CWA SHOULD BE
RAIN-FREE AND SEEING PLENTY OF SUN...AS THE PARENT MID LEVEL
TROUGH AXIS AND RESULTANT MID LEVEL SATURATION STARTS TO FOCUS
EAST OF THE AREA. TEMP WISE...LOWERED HIGHS 2-3 DEGREES FROM
PREVIOUS IN MOST AREAS...FOLLOWING THE RAW 12Z NAM SOLUTION
CLOSELY AND RANGING FROM LOW 70S NORTHWEST TO UPPER 70S SOUTHEAST.
DID LOWER DEWPOINTS SEVERAL DEGREES ESPECIALLY DURING THE MID-LATE
AFTERNOON WITH WIDESPREAD LOW-MID 30S AND EVEN UPPER 20S
NORTHWEST.
LONG TERM...MONDAY NIGHT THROUGH SUNDAY. SURFACE HIGH PRESSURE
BUILDS SOUTH BEHIND THE COLD FRONTAL BOUNDARY...WITH RIDGE AXIS
SETTLING ACROSS NEBRASKA AND WESTERN KANSAS MONDAY NIGHT. THE RIDGE
DOES WEAKEN...HOWEVER IN THE COOLER...DRY AIRMASS WITH LIGHT WINDS
AND GOOD RADIATIONAL CONDITIONS...WE ARE LOOKING AT THE POTENTIAL
FOR SOME CHILLY OVERNIGHT LOW TEMPERATURES. SFC DPS DROP TO THE 20S
AND LOWER 30S AND ITS LOOKING LIKE OVERNIGHT LOWS WILL AGAIN FALL
INTO THE TEMPERATURE RANGE FAVORABLE FOR FROST...IN THE LOW/MID
30S. THESE LOCATIONS HAVE ALREADY EXPERIENCED SIMILAR LOW TEMPS
THIS SEASON OR COLDER AND WILL NOT MENTION FROST...BUT WILL NEED TO
MONITOR FOR FREEZE CONDITIONS FOR LOCATIONS THAT HAVE YET TO FREEZE.
THE SURFACE RIDGE AXIS WASHES OUT/SHIFTS EAST ON TUESDAY WITH RETURN
FLOW SETTING UP AHEAD OF A DEEPENING SURFACE LOW IN
MANITOBA...ASSOCIATED WITH UPSTREAM TROUGH ALONG THE US/CANADIAN
BORDER. SHORTWAVE RIDGING NOSES ONTO THE CENTRAL PLAINS IN BETWEEN
UPPER LOW TO THE SOUTHEAST AND TROUGH ENTERING THE NORTHERN
ROCKIES. TEMPERATURES WILL MODERATE TUESDAY...BUT WITH COOL START
TO THE DAY AND LESS MIXING WILL AIM FOR HIGHS IN THE MID 70S VS NEAR
80F.
WEDNESDAY IS REALLY ONE OF THE TRICKIER DAYS DUE TO TIMING OF COLD
FRONTAL PASSAGE. UPPER LOW PRESSURE TROUGH REACHES THE NORTHERN
PLAINS AND ROCKIES WITH THE ASSOCIATED COLD FRONT MOVING INTO
WESTERN NEBRASKA BY 12Z WEDNESDAY. THERE ARE IMPRESSIVE PRESSURE
RISES OF 10+MB PROGGED BEHIND THE FRONT IN THE NEB PANHANDLE. IN
GENERAL MODELS HAVE TRENDED FASTER WITH FRONTAL PASSAGE WITH THE
BOUNDARY THROUGH AT LEAST OUR WESTERN THIRD CWA...IF NOT HALF OF THE
CWA BY 18Z. WITH THE FASTER TREND...HAVE SHARPENED TEMP GRADIENT
NW/SE WITH AND LOWERED HIGHS IN OUR NORTHWEST TO THE LOW 70S. IF
FRONT TRENDS ANY FASTER...COULD SEE TEMPS FALLING DURING THE
AFTERNOON AND OUR NW ZONES MAY NOT REACH 70F. THIS BEING SAID...IF
FRONT IS SLOWER AND MORE IN LINE WITH ECMWF VS NAM/GFS...TEMPS MAY
BE WARMER THAN CURRENT FORECAST.
PCPN CHCS INCREASE WEDNESDAY NIGHT IN INCREASING UPPER DYNAMICS AS
TROUGH CROSSES THE CENTRAL PLAINS. THE 12Z GFS AND GEM ARE DEEPER
WITH TROUGH THAN THE MORE PROGRESSIVE 00Z AND 12Z RUNS OF THE
ECMWF. HAVE CONCERNS THAT ECMWF IS TOO PROGRESSIVE WITH
SYSTEM...AND GFS/GFS ENSEMBLE LOOKS TO BE DECENT COMPROMISE BETWEEN
ECMWF AND GEM SOLUTIONS. IF THE DEEPER TROUGH SOLUTIONS VERIFY WE
COULD SEE A DECENT CHC FOR RAIN...BUT WOULD LIKE TO SEE MORE
CONSISTENCY BEFORE RAISING POPS. THE TROUGH AXIS DEPARTS THURSDAY
MORNING...WITH PCPN ENDING W/E.
THEREAFTER FOR THE REMAINDER OF THE WORKWEEK AND INTO NEXT
WEEKEND...PATTERN WILL BE INFLUENCED BY UPPER TROUGH ENCOMPASSING
MUCH OF THE INTERIOR CONUS. TEMPERATURES WILL REMAIN BELOW NORMAL
AND THERE WILL BE SOME HIT OR MISS CHCS FOR RAIN SHOWERS AS ENERGY
TRANSLATES THRU FLOW.
FIRE WEATHER...ALTHOUGH FIRE WEATHER CONDITIONS ARE CURRENTLY
FORECAST TO FALL JUST A BIT SHORT OF CRITICAL THRESHOLDS ON
MONDAY AFTERNOON THANKS TO RELATIVE HUMIDITY VALUES HOLDING AT
LEAST SLIGHTLY ABOVE 20 PERCENT...THE CURRENTLY FORECAST
COMBINATION OF SUSTAINED NORTHERLY WINDS AROUND 25 MPH/GUSTS
30-35 MPH AND RELATIVE HUMIDITY VALUES FALLING INTO THE 22-26
PERCENT RANGE FOR A FEW HOURS IS MORE THAN ENOUGH TO WARRANT THE
CONTINUATION OF ELEVATED TO NEAR-CRITICAL FIRE DANGER WORDING IN
THE HAZARDOUS WEATHER OUTLOOK. BASED ON RAINFALL TRENDS OVER THE
PAST MONTH AND OFFICIAL FIRE GROWTH FUEL STATUS FROM FIRE
MANAGERS...THE NEBRASKA COUNTIES WILL GENERALLY BE UNDER THE GUN
MORE SO THAN KS. ONE FACTOR THAT MIGHT BE JUST ENOUGH TO SPARE US
FROM DROPPING TO 20 PERCENT OR LOWER RELATIVE HUMIDITY IS THAT
HIGH TEMPS WERE LOWERED 2-3 DEGREES FROM PREVIOUS FORECAST.
HOWEVER...DEWPOINTS WERE ALSO DROPPED AT LEAST 5 DEGREES FROM
PREVIOUS FORECAST IN MOST AREAS DURING THE KEY MID-LATE AFTERNOON
HOURS...NOW ADVERTISED BETWEEN THE UPPER 20S AND MID 30S IN MOST
COUNTIES. NEXT FEW SHIFTS WILL HAVE TO KEEP A CLOSE EYE ON THESE
DEWPOINT/RH TRENDS...AS ONLY A SLIGHT DOWNWARD ADJUSTMENT COULD
REQUIRE HEADLINE ISSUANCE FOR AT LEAST A SMALL PART OF MAINLY THE
WESTERN CWA. LOOKING BEYOND MONDAY...WILL ALSO HAVE TO KEEP AN EYE
ON WEDNESDAY AFTERNOON FOR OUR NEXT POTENTIALLY NEAR-CRITICAL FIRE
DANGER SITUATION...AS NORTHERLY WINDS INCREASE AGAIN BEHIND THE
NEXT COLD FRONT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...BRYANT
SHORT TERM/FIRE WEATHER...PFANNKUCH
LONG TERM...FAY
AREA FORECAST DISCUSSION
NWS BUFFALO NY
345 PM EDT SAT SEP 29 2012
.SYNOPSIS...
A POTENT UPPER LEVEL LOW WILL DROP SOUTH INTO THE REGION
TONIGHT...BRINGING AN INCREASING CHANCE FOR RAIN SHOWERS TONIGHT AND
SUNDAY. INTERMITTENT SHOWERS WILL TAPER OFF IN WESTERN SECTIONS
SUNDAY NIGHT...BUT WILL LINGER EAST OF LAKE ONTARIO INTO MONDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
FOR THE REMAINDER OF THIS AFTERNOON...SHOWERS WHICH WERE FORECAST BY
THE HRRR AND RGEM HAVE YET TO DEVELOP AS OF 300 PM. THE ATMOSPHERE
IS MARGINALLY UNSTABLE...BUT IT WILL LIKELY TAKE A CONVERGENCE
BOUNDARY TO INITIATE SHOWERS WITH THE UPPER LOW STILL WELL NORTH OF
LAKE HURON. BECAUSE THESE MODELS WERE TOO AGGRESSIVE IN DEVELOPING A
SW FLOW OFF LAKE ERIE...EXPECT THEIR QPF FIELDS SUFFERED. WHILE
A STRAY SHOWER CAN/T BE RULED OUT SOUTH OF A BUFFALO TO ROCHESTER
LINE...COVERAGE SHOULD BE QUITE SPARSE. LATE AFTERNOON TEMPERATURES
WILL RANGE FROM THE UPPER 50S TO LOWER 60S...WARMEST NEAR THE LAKES.
FOR TONIGHT...THE UPPER LOW WILL DROP SOUTHWARD...EVENTUALLY
SETTLING ACROSS WESTERN NEW YORK SUNDAY MORNING. THIS WILL BRING TWO
REASONS FOR AN INCREASING CHANCE OF SHOWERS. THE FIRST IS SIMPLY
ASSOCIATED WITH THE UPPER LOW...AS IT WILL ENHANCE LIFT AS IT MOVES
INTO THE REGION. THE LAKES WILL ALSO PROVIDE AN ENHANCEMENT...WITH
LAKE INDUCED CAPES RISING TO AROUND 1000 J/KG AS THE UPPER LOW COOLS
TEMPERATURES ALOFT.
FOLLOWING A LARGELY DRY START TO THE EVENING...EXPECT SOME SCATTERED
SHOWERS TO MOVE INTO FAR WESTERN SECTIONS. MEANWHILE...NIGHTFALL
SHOULD HELP FOCUS A NE FLOW ON LAKE ONTARIO INTO A BAND OF SHOWERS
ON THE SOUTHERN THIRD OF THE LAKE...STEAMING INTO FAR NORTHERN
NIAGARA COUNTY AND THE NIAGARA ESCARPMENT. A SIMILAR STORY SHOULD
PLAY OUT ON LAKE ERIE...BUT THIS BAND SHOULD BE AS ORGANIZED ON
WESTERN PORTIONS OF THE LAKE GIVEN THE SHORTER FETCH. AS THE NIGHT
GOES ON...WINDS WILL SHIFT WITH A MORE NORTHERLY COMPONENT. THIS WILL
LIKELY PUSH THESE SHOWERS ONSHORE INTO NIAGARA/ORLEANS COUNTIES LATE
TONIGHT. ELSEWHERE...SEE A CHANCE OF SHOWERS IN WESTERN
LOCATIONS...THIS MAINLY DUE TO THE UPPER LOW AND ANY LEFT OVER
AFTERNOON SHOWERS.
FOR SUNDAY...THE UPPER LOW WILL CONTINUE TO PUSH MOISTURE ACROSS THE
REGION. MEAN QPF AMONG MODEL GUIDANCE (GFS/NAM/RGEM) IS QUITE
UNIMPRESSIVE...WITH GENERALLY LIGHT RAINFALL AMOUNTS AVERAGING LESS
THAN A TENTH OF AN INCH. GIVEN THE CONVECTIVE NATURE OF THIS...CAN
SEE A FEW SPOTS DODGING THE SHOWERS...HOWEVER THE MAJORITY OF
LOCATIONS SHOULD HAVE AT LEAST SOME MEASURABLE RAIN. WENT WITH HIGH
LIKELY POPS AS A COMPROMISE HERE...BUT KEEP IN MIND RAINFALL AMOUNTS
SHOULD GENERALLY BE LIGHT WITH THIS EVENT...WITH THE POSSIBLE
EXCEPTION OF LAKE EFFECT RAIN SHOWERS IN THE NIAGARA FRONTIER LATE
TONIGHT INTO SUNDAY MORNING. SHOWERS WILL GRADUALLY END FROM WEST TO
EAST AS THE UPPER LEVEL LOW SLOWLY MOVES TO THE EAST ON SUNDAY.
OTHERWISE...THE CLOUD COVER WILL KEEP TEMPERATURES FROM CHANGING
MUCH FROM TONIGHT TO SUNDAY. LOWS WILL MAINLY BE IN THE MID AND
UPPER 40S ACROSS THE CWA FOR TONIGHT...WITH HIGHS IN THE UPPER 50S
SUNDAY. WHILE IT SHOULD BE MAINLY CLOUDY DURING THE PERIOD...PATCHY
CLEARING IS POSSIBLE...WITH ANY CLEARING PRONE TO MORE DIURNAL
SWINGS. AREAS OF FOG APPEAR LIKELY EAST OF LAKE ONTARIO...WHERE THE
NORTHEAST FLOW SHOULD HELP PUSH IN LOW CLOUDS AND FOG IN. THIS IS
SHOWN BY BOTH THE NAM/RAP BUFKIT SOUNDINGS. THERE ALSO MAY BE PATCHY
FOG IN THE VALLEYS OF THE SOUTHERN TIER...WITH FOG POSSIBLE IN ANY
AREAS OF PROLONGED CLEARING TONIGHT.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
THE DEEP CLOSED LOW OVER NEW YORK STATE WILL FINALLY LIFT OUT TO NEW
ENGLAND SUNDAY NIGHT...BEFORE SETTLING OVER THE CANADIAN MARITIMES
ON MONDAY. ONGOING SHOWERS ASSOCIATED WITH THE LOW WILL TAPER OFF
SUNDAY NIGHT. THE EXCEPTION TO THIS GENERAL TREND WILL BE EAST OF
LAKE ONTARIO WHERE A WEST TO NORTHWEST FETCH OFF THE LAKE AND
MARGINALLY COLD AIR ALOFT WILL GENERATE SOME LAKE EFFECT RAIN
SHOWERS. THERE MAY ALSO BE A LINGERING CONTRIBUTION FROM MOISTURE
WRAPPING AROUND THE SLOWLY DEPARTING UPPER LOW. A SHALLOWER LAYER OF
MOISTURE IS EXPECTED TO BE IN PLACE EAST OF LAKE ERIE. THIS WILL
LIKELY PRECLUDE THE DEVELOPMENT OF LAKE EFFECT RAIN...BUT SOME
CLOUDS MAY LINGER IN THE WESTERLY UPSLOPE FLOW.
ANY LINGERING INFLUENCE FROM THE DEPARTING LOW AND LAKE EFFECT
SHOULD END MONDAY MORNING. OTHERWISE...WEAK HIGH PRESSURE SITUATED
BETWEEN THE DEPARTING LOW CANADIAN MARITIMES LOW AND A SECOND LOW IN
PLACE OVER THE LOWER MISSISSIPPI VALLEY WILL BRING FAIR WEATHER AND
A RETURN TO SOME SUNSHINE...ESPECIALLY DURING THE AFTERNOON. AREA
TEMPERATURES WILL BE CLOSE TO SEASONAL AVERAGES.
MONDAY NIGHT WILL FEATURE AN INCREASE IN CLOUDS AS A DEEP LAYERED
SOUTHERLY FLOW TAPS MOISTURE FROM THE NORTHERN GULF STATES. WARM AIR
ADVECTION ON THE NOSE OF A MODEST LOW LEVEL JET THAT WILL BE MOVING
NORTH ACROSS THE OHIO VALLEY WILL A CHANCE OF RAIN SHOWERS TO THE
SOUTHERN TIER BEFORE DAYBREAK TUESDAY. THE INCREASE IN CLOUDS AND
DEEPENING SOUTHERLY FLOW WILL KEEP TEMPERATURES FAIRLY MILD...WITH
MOST AREAS EXPECTED TO READINGS IN THE LOWER 50S.
ON TUESDAY...THE LOWER MISSISSIPPI VALLEY UPPER LOW WILL BEGIN TO
OPEN UP AS A DEEPENING TROUGH DIGS SOUTH ACROSS THE NORTHERN ROCKIES
AND NORTHERN PLAINS STATES. AS THE ATTENDANT SURFACE LOW AND ITS
ASSOCIATED WARM FRONT LIFT TO THE NORTH...SHOWERS WILL SPREAD NORTH
ACROSS OUR CWA. THIS TREND WILL CONTINUE INTO TUESDAY NIGHT AS THE
WARM FRONT LIFTS NORTH TOWARD NEW YORK STATE. STABILITY INDICES
SUGGEST A POSSIBILITY OF ELEVATED CONVECTION AS THE WARM FRONT LIFTS
SLOWLY TO THE NORTH.
THE SOUTHERLY FLOW WILL ALLOW TEMPERATURES TO WARM INTO THE MID AND
UPPER 60S TUESDAY...IN SPITE OF THE INCREASING CHANCES FOR RAIN.
RATHER MILD CONDITIONS WILL CONTINUE TUESDAY NIGHT WITH TEMPERATURES
EXPECTED TO HOLD STEADY IN THE MID TO UPPER 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
A PERIOD OF WARMER THAN AVERAGE TEMPERATURES WITH SOME LATE
SEPTEMBER CONVECTION IS POSSIBLE DURING THE FIRST PART OF THIS
FORECAST PERIOD...BEFORE A TRANSITION TO MID FALL-LIKE WEATHER TAKES
PLACE ON SATURDAY.
THE UPPER TROUGH THAT WILL BE IN PLACE OVER THE TENNESSEE VALLEY
WEDNESDAY MORNING IS FORECAST TO NORTHEAST TOWARD THE LOWER GREAT
LAKES WEDNESDAY AFTERNOON...THEN SHIFT EAST ACROSS NEW YORK STATE
WEDNESDAY NIGHT. THE LIFT ASSOCIATED WITH THIS IMPULSE...COMBINED
WITH THE ONGOING WARM AIR ADVECTION PATTERN...WILL BRING A CHANCE
FOR A FEW MORE SHOWERS. THERE MAY BE SUFFICIENT ELEVATED INSTABILITY
TO RESULT IN SCATTERED CONVECTION. IT WILL BE EVEN WARMER ON
WEDNESDAY WITH TEMPERATURES EXPECTED TO RISE WELL INTO THE 60S AND
MAYBE EVEN LOWER 70S ACROSS THE LOWER ELEVATIONS OF THE LAKE PLAINS.
THE UPPER LEVEL TROUGH IS FORECAST TO SHIFT EAST INTO NEW ENGLAND ON
THURSDAY. RIDGING BEHIND THE TROUGH SHOULD BRING FAIR WEATHER FOR
THURSDAY AND ANOTHER DAY OF UNSEASONABLE WARM TEMPERATURES.
A POTENT COLD FRONT ASSOCIATED WITH A DEEPENING CANADIAN TROUGH WILL
CROSS THE CWA ON FRIDAY. THIS WILL BRING ANOTHER CHANCE FOR SHOWERS
AND POSSIBLE THUNDERSTORMS. STRONG COLD AIR ADVECTION SETTING BEHIND
THE FRONT WILL BRING A CHANCE FOR SOME LAKE EFFECT PCPN...WHILE
TEMPERATURES RANGE THROUGH THE 50S ON SATURDAY.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AN UPPER LEVEL LOW WILL DROP ACROSS THE REGION OVERNIGHT...SETTLING
ACROSS WESTERN NEW YORK SUNDAY. THIS WILL BRING AN UNSETTLED
PATTERN...WITH A FAIR AMOUNT OF LOW LEVEL MOISTURE...BUT ONLY
SPARSE SHOWER COVERAGE.
FOR THE REMAINDER OF TODAY...EXPECT MAINLY VFR CONDITIONS...OUTSIDE
OF SPOTTY AREAS OF SHOWERS AND LOWER CIGS. WITH THE APPROACH OF
THE UPPER LOW...AND A PERSISTENT NE FLOW TONIGHT...EXPECT MOISTURE
TO INCREASE WHICH WILL LIKELY LOWER CIGS TO MVFR OR LOWER IN
SPOTS. TIMING THIS IS A BIT OF A CHALLENGE...SINCE LOWER CIGS WILL
BUILD IN GRADUALLY REFLECTING THE SLOW MOVEMENT OF THE UPPER LOW.
THE CHANCE FOR SHOWERS WILL ALSO INCREASE...WITH A FAIRLY GOOD
CHANCE FOR SOME LIGHT SHOWERS BY SUNDAY MORNING. THE BEST CHANCE
FOR IFR OR LOWER CONDITIONS IS AT ART...WHERE A NE UPSLOPE FLOW
WILL LIKELY DEVELOP LATE TONIGHT...WHICH COULD RESULT IN VERY LOW
CIGS AND OR FOG. THIS SAID...THE MOIST FLOW COULD POTENTIALLY
PRODUCE IFR OR LOWER CIGS...AND EVEN FOG...AT ALL TAF SITES LATE
TONIGHT THROUGH SUNDAY MORNING...HOWEVER FORECAST HEDGES A BIT
MORE OPTIMISTIC AT BUF/IAG/ROC/JHW THAN AT ART.
OUTLOOK...
SUNDAY AFTERNOON AND NIGHT...MVFR/IFR WITH INTERMITTENT SHOWERS.
MONDAY...MAINLY VFR.
TUESDAY AND WEDNESDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
THURSDAY...MAINLY VFR.
&&
.MARINE...
AN UPPER LEVEL LOW WILL DROP SOUTH OUT OF CANADA THROUGH SUNDAY. A
FEW PERIODS OF NORTH TO NORTHEAST WINDS IN THE 10-15 KNOT RANGE WILL
BRING CHOPPY WAVES TO THE SOUTH SHORE OF LAKE ONTARIO AT TIMES...BUT
CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA.
A SURFACE LOW WILL DEEPEN OVER NEW ENGLAND LATER SUNDAY NIGHT AND
MONDAY AND BRING INCREASING WESTERLY WINDS TO LAKE ONTARIO. THIS
WILL LIKELY BRING A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS FROM
LATER SUNDAY NIGHT THROUGH MONDAY...ESPECIALLY ON THE EAST HALF.
COLD AIR ALOFT AND SOME CONVECTIVE SHOWERS WILL BRING THE POTENTIAL
FOR WATERSPOUTS LATER TONIGHT INTO SUNDAY MORNING ON BOTH LAKES ERIE
AND ONTARIO. WATERSPOUTS ARE MOST COMMON IN AND NEAR BANDS OF CLOUDS
LAKE EFFECT CLOUDS AND SHOWERS WHERE LOW LEVEL CONVERGENCE IS
LOCALLY MAXIMIZED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP
LONG TERM...TJP
AVIATION...APFFEL
MARINE...APFFEL/TJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
946 AM EDT SAT SEP 29 2012
.SYNOPSIS...
MOST AREAS WILL REMAIN DRY TODAY WITH VARYING AMOUNTS OF CLOUD
COVER. THERE IS JUST A SMALL CHANCE OF AN ISOLATED SHOWER THIS
AFTERNOON ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND ALSO
EAST OF LAKE ONTARIO. A POTENT UPPER LEVEL LOW WILL DROP SOUTH INTO
THE REGION TONIGHT WITH INCREASING RAIN CHANCES ESPECIALLY ACROSS
WESTERN NY. INTERMITTENT SHOWERS WILL CONTINUE SUNDAY AND SUNDAY
NIGHT AS THIS SYSTEM MOVES SLOWLY EAST ACROSS THE AREA. SHOWERS WILL
LINGER EAST OF LAKE ONTARIO INTO MONDAY WHILE THE REST OF THE REGION
DRIES OUT AS HIGH PRESSURE BUILDS INTO THE GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH MID-MORNING...SHOWERS EAST OF LAKE ONTARIO HAVE
DIMINISHED. RADAR DID PICK UP AN ISOLATED SHOWERS ALONG THE
MONROE/WAYNE COUNTY BORDER WHICH DEVELOPED ALONG A CONVERGENCE OF
BOUNDARIES. THIS SHOULD BE FAIRLY SHORT LIVED...GIVEN THE
TEMPORARY NATURE OF THE SUBTLE CONVERGING FEATURES.
OTHERWISE...VISIBLE SATELLITE SHOWED LOW CLOUDS AND FOG IN
NORTHERN JEFFERSON COUNTY...LIKELY ENHANCED BY AN UPSLOPE
NORTHEAST FLOW. THIS AREA SHOULD ALSO DISSIPATE THROUGH THIS
MORNING WITH DAYTIME HEATING.
FOR THE REST OF TODAY...A MID LEVEL CLOSED LOW DEVELOPING OVER
NORTHERN QUEBEC WILL DROP QUICKLY SSW AND REACH GEORGIAN BAY BY
THIS EVENING. MEANWHILE THE WEAK SURFACE LOW ALONG THE SOUTHERN
NEW ENGLAND COAST EARLY THIS MORNING WILL BECOME CAPTURED BY THE
BROADENING CIRCULATION OF THE CLOSED LOW...AND WILL MOVE NORTHWARD
ALONG THE MAINE COAST. THE WESTERN EDGE OF DEEPER MOISTURE AND MID
LEVEL DEFORMATION ASSOCIATED WITH THIS COASTAL LOW WILL REMAIN
ACROSS THE ADIRONDACKS AND SAINT LAWRENCE VALLEY TODAY. THIS MAY
STAY JUST CLOSE ENOUGH TO SUPPORT A FEW MORE ISOLATED SHOWERS
ACROSS PORTIONS OF LEWIS AND NORTHEAST JEFFERSON COUNTY. THERE MAY
ALSO BE AN ISOLATED SHOWER OR TWO ACROSS THE HIGHER TERRAIN OF THE
WESTERN SOUTHERN TIER AND FINGER LAKES THIS AFTERNOON IN RESPONSE
TO VERY LIMITED DIURNAL INSTABILITY AND NORTHERLY UPSLOPE FLOW.
FINALLY...THE HRRR SUGGESTS A WEAK SW LAKE BREEZE WILL DEVELOP ON
LAKE ERIE...WHICH IF IT DEVELOPS COULD CAUSE A FEW ISOLATED
SHOWERS MAY DEVELOP IN THE NIAGARA ESCARPMENT. IN ALL OF THESE
CASES...THE CAUSE FOR SHOWERS IS QUITE SUBTLE...AND ANY ACTIVITY
SHOULD BE ISOLATED IN NATURE.
850MB TEMPS OF AROUND +4C WILL SUPPORT HIGHS IN THE LOWER TO MID 60S
ACROSS LOWER ELEVATIONS...AND UPPER 50S ACROSS HIGHER TERRAIN WHERE
CLOUD COVER SHOULD BE THICKER AND MORE PERSISTENT.
TONIGHT...THE MID LEVEL LOW WILL CONTINUE SSW ACROSS LAKE HURON THEN
BEGIN TO PIVOT EAST ACROSS WESTERN NY/PA BY EARLY SUNDAY MORNING.
INCREASING DPVA IN ADVANCE OF THIS STRONG MID LEVEL CLOSED LOW WILL
BRING INCREASING CHANCES OF A FEW SHOWERS OVERNIGHT ACROSS WESTERN
NY...AND ALSO ACROSS THE EASTERN LAKE ONTARIO REGION. THE LOWEST
RAIN CHANCES OVERNIGHT WILL BE ACROSS THE FINGER LAKES AND CENTRAL
NY WHERE DEEPER MOISTURE AND ASCENT IS SLOW TO ARRIVE.
THE NAM...CANADIAN GEM AND SEVERAL VERSIONS OF OUR LOCALLY RUN
WORKSTATION WRF SUGGEST SOME LAKE EFFECT RAIN MAY DEVELOP OVERNIGHT
OVER BOTH LAKES ERIE AND ONTARIO IN WEAK EASTERLY FLOW. TEMPS ALOFT
WILL COOL WITH THE APPROACH OF THE UPPER LOW...AND THIS WILL SUPPORT
LAKE INDUCED EQUILIBRIUM LEVELS OF AROUND 25K FEET. THE VERY WEAK
AND SOMEWHAT SHEARED FLOW WILL KEEP WHAT FORMS DISORGANIZED...
ALTHOUGH IT MAY BE QUITE CONVECTIVE GIVEN THE HIGH EQUILIBRIUM
LEVELS WITH EVEN SOME THUNDER POSSIBLE. THE MEAN EASTERLY BOUNDARY
LAYER FLOW WILL KEEP MUCH OF THIS ACTIVITY OVER THE LAKES...BUT SOME
MAY BEGIN TO BRUSH THE LAKE ONTARIO SHORELINE FROM THE BRADDOCK
BAY/HAMLIN AREA OF MONROE COUNTY WEST ACROSS ORLEANS AND NIAGARA
COUNTIES LATE TONIGHT. HAVE INDICATED THE HIGHEST RAIN CHANCES AND
RAIN AMOUNTS IN THAT AREA OVERNIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
A COOL AND DAMP DAY IS EXPECTED ON SUNDAY TO CLOSE OUT THE WEEKEND.
FORECAST MODELS ARE IN GOOD AGREEMENT OF PLACING A CUT-OFF LOW OF
COLD AIR ALOFT DIRECTLY OVERHEAD OF WESTERN NEW YORK SUNDAY MORNING.
THE 00Z GFS BUFKIT PROFILE FOR KBUF SHOWS A STEADY MOIST ADIABATIC
TEMPERATURE LAPSE RATE FROM THE SURFACE RIGHT THROUGH AROUND 400 MB
AT 15Z SUNDAY. THIS WILL PROVIDE SUFFICIENT SYNOPTIC INSTABILITY FOR
RAIN SHOWERS WHICH SHOULD BE ONGOING AT THE START OF THE SHORT TERM
PERIOD.
IF THIS WERE TROPICALLY SOURCED AIR THIS SETUP WOULD MAKE FOR VERY
HEAVY RAIN ACROSS THE FORECAST AREA SUNDAY...BUT THIS IS NOT THE
CASE. THE SOURCE REGION OF THE AIRMASS ALOFT IS CONTINENTAL POLAR
AND IS HAS LIMITED MOISTURE. PRECIPITABLE WATER VALUES WILL ONLY BE
AROUND 0.75 INCHES. THIS IS ABOUT NORMAL FOR LATE SEPTEMBER WITH A
NEUTRAL ANOMALY SO NO HEAVY RAIN WILL BE FORECAST. QPF SUNDAY WILL
ONLY RANGE BETWEEN 0.10 AND 0.25 INCH IN LIGHT SHOWERS. TEMPERATURES
WILL NOT CLIMB MUCH WITH OVERCAST SKIES AND PRECIP AROUND MUCH OF
THE DAY. WITH COOL AIR ALOFT...AND 850 MB TEMPS OF ONLY AROUND +4C
HIGHS WILL ONLY REACH INTO THE MID 50S ACROSS THE SOUTHERN TIER TO
AROUND 60 EAST OF LAKE ONTARIO NORTH OF THE TRACK OF THE UPPER LOW.
ADDITIONALLY...DESPITE SIGNIFICANT LAKE INDUCED INSTABILITY...THE
PATTERN DURING THE DAY SUNDAY IS NOT FAVORABLE FOR ANY LAKE EFFECT
PRECIPITATION GIVEN THE WEAK FLOW OVER THE LAKES. WINDS IN THE LOWER
HALF OF THE ATMOSPHERE WILL BE LESS THAN 10 KNOTS WHICH WILL NOT
ALLOW ANY ORGANIZED BANDS TO FORM.
BY SUNDAY NIGHT A DISTURBANCE ROUNDING THE WESTERN SIDE OF THE UPPER
LOW WILL ACT TO KICK THE SYSTEM TO THE NORTHEAST UP THROUGH NEW
ENGLAND AND OVER THE MOUTH OF THE SAINT LAWRENCE RIVER. RAIN SHOWERS
WILL TAPER OFF QUICKLY SUNDAY EVENING AS THE MOISTURE EXITS THE
FORECAST AREA WITH THE UPPER LOW. AT THIS POINT THE POSITION OF THE
THE UPPER LOW TO THE NORTHEAST WILL BRING AN INCREASED WIND FLOW AND
FETCH ACROSS LAKE ONTARIO. THIS WEST TO NORTHWEST FLOW WILL ALLOW
FOR AN EXTENDED CHANCE OF RAINFALL IN THE FORM OF LAKE EFFECT ON
SUNDAY NIGHT EAST OF LAKE ONTARIO WHILE WESTERN NEW YORK BEGINS TO
DRY OUT. LOW TEMPS...ESPECIALLY IN AREAS WHERE SKIES CLEAR...WILL
FALL INTO THE MIDDLE TO UPPER 40S. SOME PATCHY FOG IS POSSIBLE
ACROSS THE SOUTHERN TIER AS THEY ARE EXPECTED TO CLEAR OUT BEFORE
OTHER PARTS OF WNY.
ON MONDAY THE UPPER LOW WILL LIFT FURTHER NORTHEAST INTO THE
CANADIAN MARITIMES AND SOME UPPER LEVEL RIDGING AND SURFACE HIGH
PRESSURE WILL BRING FAIR WEATHER WITH A RETURN OF SOME SUNSHINE.
HIGHS WILL BE A BIT WARMER WITH WINDS ADVECTING OUT OF THE
SOUTHEAST. HIGHS SHOULD CLIMB INTO THE 60S WITH 850 MB TEMPS WARMING
TO NEAR +8C. FURTHER UPSTREAM...IN THIS CASE ACROSS THE NORTHERN
GULF COAST...A MOIST SURFACE LOW WILL BE FORMING WITH +2 SD
PRECIPITABLE WATER VALUES.
MONDAY NIGHT BRINGS AN RETURN OF CLOUDS AS WARM ADVECTION SETS UP
AHEAD OF THE NEXT STORM SYSTEM APPROACHING FROM THE NORTHERN GULF.
850MB TEMPS WILL RISE TO +10 TO +12C OVERNIGHT AND SURFACE TEMPS MAY
ACTUALLY RISE FOR A TIME DURING THE NIGHT. MILD LOWS WILL RUN IN THE
LOW TO MID 50S. A CHANCE OF SHOWERS WILL ALSO DEVELOP AS A SURFACE
WARM FRONT ASSOCIATED WITH THE LOW LIFTS ACROSS THE CENTRAL
APPALACHIANS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A PERIOD OF WARMER THAN NORMAL TEMPS WITH SOME LATE SEPTEMBER
CONVECTION IS POSSIBLE LATER NEXT WEEK. A DEEP TROUGH OVER THE
CENTRAL US WILL LIFT NORTHEAST TUESDAY INTO WEDNESDAY. AHEAD OF THE
TROUGH A GULF LOW WILL BRING AN INCREASE IN MOISTURE ACROSS NEW YORK
UNDER A FULL CONUS LATITUDE SOUTHERLY FLOW. THIS KEEPS A CHANCE FOR
RAIN SHOWERS IN THE FORECAST FOR TUESDAY. CONVECTIVE PARAMETERS ARE
NEAR ZERO ACROSS THE FORECAST AREA WITH WARM AIR INCREASING ALOFT.
THE RAIN WILL MAINLY BE WARM FRONTAL. THIS COULD BRING UPWARDS OF A
HALF INCH OR MORE OF RAIN. HIGHS WILL REACH INTO THE UPPER 60S TO
NEAR 70.
ON WEDNESDAY A CHANCE FOR THUNDERSTORMS DEVELOPS AS THE UPPER LEVEL
TROUGH DIGGING NORTHEAST FROM THE GULF COAST BRINGS COOL AIR ALOFT
DESTABILIZING THE ATMOSPHERE. THE THUNDERSTORMS COULD FORM ALONG A COLD
FRONT ASSOCIATED WITH THE SURFACE LOW LIFTING NORTH INTO CANADA.
TEMPS WARM EVEN MORE WITH MOST SPOTS GETTING UPPER 60S TO EVEN SOME
MID 70S ACROSS CENTRAL NY.
RIDGING BEHIND THE TROUGH SHOULD BRING FAIR WEATHER FOR THURSDAY
AND ANOTHER DAY OF WARM TEMPS. THEN ON FRIDAY THE 00Z GFS AND ECMWF
BOTH SHOW A LARGE TROUGH DIGGING ACROSS THE WEST COAST WITH A COLD
FRONT POSSIBLY BRINGING ANOTHER SHOT AT THUNDERSTORMS ON FRIDAY.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
PATCHY FOG WITH LOCAL IFR ACROSS THE SOUTHERN TIER WILL BURN OFF IN
THE NEXT HOUR OR TWO...WITH VFR PREVAILING THEREAFTER. AREAS OF MID
LEVEL CLOUD IN THE 4-8K FOOT RANGE ACROSS CENTRAL NY WILL DRIFT EAST
THIS MORNING AND THEN TEND TO REDEVELOP FARTHER WEST THIS AFTERNOON.
PERIODS OF CIRRUS WILL ALSO CROSS THE REGION TODAY.
TONIGHT AN UPPER LEVEL LOW WILL DROP SOUTH ACROSS THE GREAT LAKES.
THIS WILL BRING INCREASING AND LOWERING CLOUD COVER ALONG WITH AN
INCREASING CHANCE OF SHOWERS ACROSS WESTERN NY OVERNIGHT. INITIALLY
THE LOW LEVELS SHOULD REMAIN UNSATURATED WITH MAINLY VFR VSBY AND
CIGS...EXCEPT FOR THE SOUTHERN TIER WHERE MVFR IS MORE LIKELY.
OUTLOOK...
SUNDAY...MVFR/IFR WITH INTERMITTENT SHOWERS.
MONDAY...MAINLY VFR.
TUESDAY AND WEDNESDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
AN UPPER LEVEL LOW WILL DROP SOUTH OUT OF CANADA LATER TODAY THROUGH
SUNDAY. A FEW PERIODS OF NORTH TO NORTHEAST WINDS IN THE 10-15 KNOT
RANGE WILL BRING CHOPPY WAVES TO THE SOUTH SHORE OF LAKE ONTARIO AT
TIMES...BUT CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA.
A SURFACE LOW WILL DEEPEN OVER NEW ENGLAND LATER SUNDAY NIGHT AND
MONDAY AND BRING INCREASING WESTERLY WINDS TO LAKE ONTARIO. THIS
WILL LIKELY BRING A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS FROM
LATER SUNDAY NIGHT THROUGH MONDAY...ESPECIALLY ON THE EAST HALF.
COLD AIR ALOFT AND SOME CONVECTIVE SHOWERS WILL BRING THE POTENTIAL
FOR WATERSPOUTS LATER TONIGHT INTO SUNDAY MORNING ON BOTH LAKES ERIE
AND ONTARIO. WATERSPOUTS ARE MOST COMMON IN AND NEAR BANDS OF CLOUDS
LAKE EFFECT CLOUDS AND SHOWERS WHERE LOW LEVEL CONVERGENCE IS
LOCALLY MAXIMIZED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...AR/APFFEL/HITCHCOCK
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
648 AM EDT SAT SEP 29 2012
.SYNOPSIS...
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE
THIS WEEKEND AS A COLD FRONT STALLS ACROSS THE EASTERN CAROLINAS.
NEXT WEEK WILL REMAIN UNSETTLED AS LOW PRESSURE DEVELOPS ALONG THE
GULF COAST AND MOVES ACROSS THE WESTERN CAROLINAS. A COLD FRONT WILL
CROSS THE AREA BY LATE WEEK BRINGING DRIER AND COOLER WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...NO SIGNIFICANT CHANGES TO THE GOING
FORECAST. CURRENTLY THE BULK OF CONVECTIVE ACTIVITY ACROSS THE
CAROLINAS REMAINS ACROSS THE NORTHERN TIER OF NC...NORTHEAST OF THE
CENTERLINE OF THE APPROACHING 300 MB JET STREAK. PREVIOUS DISCUSSION
FROM 300 AM FOLLOWS...
A SIGNIFICANT CHANGE IN THE WEATHER WILL BEGIN TODAY AS A COLD FRONT
AND ITS ASSOCIATED UPPER LEVEL SYSTEM BEGIN TO AFFECT THE EASTERN
CAROLINAS. THE FRONT CURRENTLY LIES STALLED ACROSS SOUTHERN NORTH
CAROLINA FROM THE SOUTH SIDE OF CHARLOTTE TO SOUTHERN PINES TO ROCKY
MOUNT. A WEAK SURFACE LOW WILL DEVELOP ALONG THE FRONT THIS
AFTERNOON...AND AS THE LOW MOVES EAST AND OFFSHORE TONIGHT THE FRONT
SHOULD GET DRAGGED OFFSHORE BY DAYBREAK SUNDAY.
THE AIRMASS SOUTH OF THE FRONT IS MARITIME SUBTROPICAL IN NATURE
WITH PRECIPITABLE WATER 1.5 TO 1.7 INCHES AND REASONABLY STEEP LAPSE
RATES ALOFT. ALTHOUGH SUNSHINE SHOULD BE FILTERED BY PLENTY OF MID
LEVEL CLOUDS (ESPECIALLY ACROSS NORTH CAROLINA) I STILL ANTICIPATE
AFTERNOON HIGHS TO REACH THE LOWER TO MID 80S FOR MOST AREAS. WITH
DEWPOINTS IN THE MID TO UPPER 60S THIS SHOULD GENERATE SBCAPE VALUES
AS HIGH AS 1200 J/KG WITH LIFTED INDICES DOWN TO -4. A BELT OF
STRONGER MID-LEVEL WINDS ASSOCIATED WITH A JET STREAK MOVING EAST
ACROSS NORTH CAROLINA WILL GENERATE 0-6 KM BULK SHEAR VALUES AROUND
30 KT...SUFFICIENT FOR MULTICELL STORM ORGANIZATION. SEVERE WEATHER
IN THE FORM OF STRONG WINDS AND MARGINALLY SEVERE HAIL CANNOT BE
RULED OUT...MAINLY THIS AFTERNOON.
INTERESTINGLY IT IS THE JET STREAK ITSELF THAT MAY SERVE TO REDUCE
COVERAGE OF SHOWERS AND STORMS THIS AFTERNOON. UNTIL EARLY EVENING
OUR FORECAST AREA WILL REMAIN WITHIN THE RIGHT-EXIT REGION OF THE
JET STREAK...A REGION TYPIFIED BY UPPER-LEVEL CONVERGENCE AND
INFERRED SINKING MOTION BENEATH. FOR THIS REASON MY FORECAST POPS
ARE CLOSER TO THE DRIER GFS MOS NUMBERS FOR TODAY...AND FOCUS ON THE
SEABREEZE AS A PREFERRED LIFTING MECHANISM. THIS EVENING THE JET
STREAK WILL MOVE INTO EXTREME EASTERN NORTH CAROLINA PLACING MY
SOUTHEASTERN NC COUNTIES AT LEAST BRIEFLY WITHIN THE RIGHT-ENTRANCE
REGION OF THE UPPER JET STREAK...A MUCH MORE FAVORABLE ZONE FOR
ENHANCED SYNOPTIC ASCENT. THIS EXPLAINS MY HIGHER POPS IN THE 8 PM
TO MIDNIGHT TIME FRAME...ESPECIALLY AROUND WILMINGTON. THE SURFACE
COLD FRONT SHOULD THEN SLIP IN FROM THE NORTHWEST AND MAKE IT
OFFSHORE BY SUNRISE SUNDAY.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...COLD FRONT OFF THE COAST AT THE START OF THE
PERIOD WILL STALL BEFORE MOVING BACK ONSHORE LATER SUN OR EARLY MON
AS A WARM FRONT. THE EVOLUTION OF A SOUTHERN STREAM 5H TROUGH AND
SURFACE LOW OVER SOUTHEAST TX WILL BE CRITICAL IN DETERMINING WHEN
THE STALLED FRONT BEGINS TO MOVE. THE FRONT WILL BE LIFTED NORTH BY
THE NORTHEAST MOVEMENT OF THE WESTERN GULF OF MEXICO SURFACE LOW SUN
INTO MON. APPROACH AND PASSAGE OF WARM FRONT WILL BE ACCOMPANIED BY
AN INCREASE IN PRECIP COVERAGE LATE SUN AND SUN NIGHT. WENT AHEAD
AND BUMPED POP TO HIGH CHANCE LATE SUN. THE COMBINATION OF
INCREASING CLOUD COVER AND SHOWERS/THUNDERSTORMS WILL KEEP HIGHS
BELOW CLIMO SUN WHILE CLOUDS AND WEAK WARM ADVECTION WILL HOLD SUN
NIGHT LOWS ABOVE CLIMO.
FORECAST AREA WILL SOLIDLY BE IN THE WARM SECTOR MON/MON NIGHT WITH
LOW LEVEL SOUTHEAST TO SOUTH FLOW VEERING WITH HEIGHT. COMBINATION
OF DEEP MOISTURE...DIURNAL INSTABILITY AND DIVERGENCE ALOFT SHOULD
PRODUCE PLENTY OF SHOWERS AND THUNDERSTORMS. ACTIVITY MAY WELL
CONTINUE MON NIGHT WITH FORECAST SOUNDINGS SHOWING DEVELOPMENT OF
STRONG LOW LEVEL JET. SOUTHERLY LOW WILL PUSH TEMPERATURES ABOVE
CLIMO MON AND MON NIGHT.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...DEEP BROAD 5H TROUGH OVER THE MS VALLEY WILL
BE SLOW TO LIFT NORTHEAST NEXT WEEK...ENSURING ACTIVE WEATHER FOR
MUCH OF THE PERIOD. DEEP SOUTHERLY FLOW THROUGH THE MIDDLE OF NEXT
WEEK ALONG WITH DIURNAL HEATING AND THE PRESENCE OF PASSING
SHORTWAVES IN FLOW ALOFT WILL LEAD TO DIURNAL SHOWERS AND
THUNDERSTORMS FOR THE FIRST HALF OF THE PERIOD. THE SECOND HALF OF
THE PERIOD REMAINS IN QUESTION AS GUIDANCE CONTINUES TO SHOW VERY
LITTLE IN THE WAY OF RUN TO RUN CONSISTENCY. THE ISSUE WILL BE HOW
QUICKLY THE 5H TROUGH IS ACCELERATED NORTHEAST AND WHETHER THE
MID LEVEL RIDGE DEVELOPING OVER THE WESTERN ATLANTIC IS STRONG
ENOUGH TO BUILD WEST LATE IN THE PERIOD. GIVEN THE UNCERTAINTY ONLY
PLAN MINIMAL CHANGES AT THIS TIME. TEMPERATURES WILL BE ABOVE CLIMO
THROUGH THE PERIOD...BUT HOW MUCH ABOVE LATE DEPENDS ON HOW THE MID
LEVEL PATTERN EVOLVES.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...CONVECTION NORTH OF THE REGION IS ASSOCIATED WITH A
FRONTAL BOUNDARY ORIENTED WEST TO EAST ACROSS CENTRAL NORTH
CAROLINA. MOST OF THIS CONVECTION WILL STAY NORTH OF THE REGION
THROUGH THE MORNING HOURS. THE HRRR MODEL DOES BRING IN A BATCH OF
CONVECTION TO OUR INLAND ZONES AROUND 19Z...REACHING THE COAST
AROUND 21Z. THERE IS MODERATE UNCERTAINTY WITH RESPECT TO COVERAGE
AND INTENSITY OF THE PRECIPITATION. THINK THE SHOWERS WILL NOT BE
TOO HEAVY AT FIRST...AS SOLAR INSOLATION WILL BE WEAK TODAY.
CONDITIONS SHOULD DETERIORATE THIS EVENING AS DEEP MOISTURE MOVES
IN...IN RESPONSE TO THE DIVERGENT QUADRANT OF THE JET. IFR CEILINGS
ARE POSSIBLE AFTER 06Z...BUT LOW CONFIDENCE ON THIS SCENARIO AT THIS
TIME.
EXTENDED OUTLOOK...POTENTIAL MORNING FOG/STRATUS SUNDAY MORNING MAY
REDUCE CIGS/VSBYS TO IFR LEVELS. UNSETTLED WEATHER ASSOCIATED WITH A
STALLED FRONTAL BOUNDARY COULD PRODUCE PERIODS OF TEMPO SUB-VFR
CONDITIONS ACROSS THE AREA THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...LATEST WIND/WAVE OBSERVATIONS CLOSELY MATCH
THE CURRENT FORECAST. NO CHANGES NEEDED. PREVIOUS DISCUSSION FROM
300 AM FOLLOWS...
A COLD FRONT HAS NEARLY STALLED ACROSS INTERIOR SOUTHERN AND EASTERN
NORTH CAROLINA. LITTLE MOTION OF THE FRONT IS EXPECTED THROUGH THIS
AFTERNOON AS WEAK LOW PRESSURE IS EXPECTED TO DEVELOP NEAR
CHARLOTTE. AS THE LOW MOVES EAST AND OFFSHORE THIS EVENING THE FRONT
WILL ACCELERATE TO THE SOUTHEAST AND SHOULD BE TRAVERSING THE
COASTAL WATERS AROUND DAYBREAK SUNDAY...WITH A WIND SHIFT FROM THE
SOUTHWEST AROUND TO THE NORTH.
WIND SPEEDS TODAY SHOULD AVERAGE AROUND 10 KNOTS...ALTHOUGH ANY
THUNDERSTORMS THIS AFTERNOON OR THIS EVENING WILL HAVE THE
CAPABILITY OF PRODUCING STRONGER...GUSTY WINDS. AS THE SURFACE LOW
PUSHES OFF THE COAST NEAR CAPE LOOKOUT LATE THIS EVENING WE MAY SEE
A PERIOD OF 15 KNOT SOUTHWESTERLY WINDS AHEAD OF THE COLD
FRONT...ESPECIALLY IN THE CAPE FEAR AREA WATERS.
SEAS ARE CURRENTLY AROUND 2 FEET WITH A DOMINANT PERIOD OF 8 TO 9
SECONDS IN EASTERLY SWELL. LITTLE CHANGE IS EXPECTED UNTIL THE FRONT
PUSHES CLOSER TO THE AREA TONIGHT...AT WHICH POINT SOME 3-FOOT
COMBINED SEAS MAY DEVELOP AWAY FROM SHORE.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...FRONT MOVING ACROSS THE WATERS EARLY SUN WILL
STALL JUST EAST OF THE WATERS BEFORE RETURNING AS A WARM FRONT LATE
SUN OR EARLY MON. OFFSHORE FLOW BEHIND THE FRONT WILL BE LIGHT WITH
LIMIT COLD ADVECTION AND WEAK GRADIENT KEEPING SPEEDS CLOSE TO 10
KT. SOUTHERLY FLOW WILL DEVELOP AS THE FRONT LIFTS...BUT GRADIENT
REMAINS WEAK AND SPEEDS WILL STAY IN THE 10 KT OR LESS RANGE. SEAS
WILL BE 2 TO 3 FT THROUGH THE PERIOD.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...GRADIENT BECOMES MORE DEFINED TUE WITH
SOUTHERLY FLOW INCREASE TO CLOSE TO 15 KT BY AFTERNOON. SOUTHERLY
FLOW BECOMES WESTERLY AND DECREASES EARLY WED AS WEAK COLD FRONT
MOVES OFF THE COAST. FRONT SHIFTS WEST DURING WED WITH WESTERLY FLOW
BACKING TO SOUTHERLY. LITTLE CHANGE TO THE GRADIENT IS EXPECTED AND
SPEEDS REMAIN CLOSE TO 10 KT THROUGH THE DAY. SEAS WILL RUN 2 TO 4
FT TUE BUT DROP BACK TO 2 TO 3 FT FOR WED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
126 AM EDT SAT SEP 29 2012
.SYNOPSIS...
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE ON THE INCREASE
THIS WEEKEND AS A COLD FRONT STALLS ACROSS THE EASTERN CAROLINAS.
NEXT WEEK WILL REMAIN UNSETTLED AS LOW PRESSURE DEVELOPS ALONG THE
GULF COAST AND MOVES ACROSS THE WESTERN CAROLINAS. A COLD FRONT WILL
CROSS THE AREA BY LATE WEEK BRINGING DRIER AND COOLER WEATHER.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 130 AM SATURDAY...RADAR LOOPS SHOW NEW SHOWERS DEVELOPING IN
THE ZONE BETWEEN CHARLOTTE AND SOUTHERN PINES. MOST OF THIS WILL
REMAIN NORTH OF OUR FORECAST AREA BUT THE SMALL (20 PERCENT) POPS
CURRENTLY IN PLACE ACROSS THE DARLINGTON-BENNETTSVILLE-LUMBERTON-
ELIZABETHTOWN CORRIDOR LOOK GOOD. OTHER THAN A FEW SMALL TWEAKS TO
TEMPERATURES AND DEWPOINTS BASED ON LATEST OBSERVATIONS...NO CHANGES
HAVE BEEN MADE. PREVIOUS DISCUSSION FROM 1030 PM FOLLOWS...
CURRENT CONVECTION AHEAD OF THE COLD FRONT CONTINUES TO DIMINISH IN
AREAL COVERAGE DURING THIS EVENING...AND SHOULD CONTINUE THIS TREND
OVERNIGHT DUE TO INSTABILITY HAVING WEAKENED. THE OUTFLOWS FROM THE
EARLIER STORMS UPSTREAM HAVE REACHED THE NORTHERN 1/3RD OF THE FA.
LATEST HRRR HAS NOW BACKED OFF WITH PCPN COVERAGE OVERNIGHT. WILL
HOWEVER CONTINUE A SLIGHT CHANCE OF PCPN FOR THE NORTHERN 1/4TH TO
1/3RD PORTIONS OF THE ILM CWA...FOR THE REMAINDER OF THE OVERNIGHT.
TWEAKED MIN TEMPS UP SOME WHERE THE THICKER AND MORE OPAQUE
CLOUDINESS WILL RESIDE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...MID LEVEL TROUGH DEEPENING OVER EASTERN GREAT
LAKES IN RESPONSE TO VERY COLD -24C 500HPA SLIDING DOWN WEST SIDE OF
THE TROUGH. COLD FRONT WILL BE DRIVEN INTO THE AREA BY BY LATE
AFTERNOON. FAIRLY GOOD FORCING WILL SPREAD ACROSS THE AREA FROM THE
NORTHWEST DUE TO HEIGHT FALLS AND INCREASING JETTING ALOFT...AND
THERE IS EVEN SOME WEAK LOW LEVEL WARM AIR ADVECTION. A LATE DAY
VORT MAX MAY ACT TO ENHANCE POPS ALONG THE COAST...BUT OVERALL
PRECIP CHANCES AND AMOUNTS WILL BE SOMEWHAT MARGINALIZED BY A LACK
OF PRE-FRONTAL MOISTURE ADVECTION DUE TO THE ABSENCE OF A STRONG
HIGH IN THE WESTERN ATLANTIC. ANOTHER MUCH WEAKER UPPER DISTURBANCE
WILL DROP INTO THE SOUTHERN MISSISSIPPI VALLEY SATURDAY NIGHT INTO
SUNDAY. THIS WILL INCITE CYCLOGENESIS OVER THE NORTHWESTERN GULF OF
MEXICO. AS THIS SYSTEM MOVES EASTWARD ACROSS THE GULF IT WILL HALT
THE PROGRESS OF THE BOUNDARY ALONG THE COAST OF THE CAROLINAS...AS
WILL THE LIFTING OUT OF THE MAIN UPPER LOW MOVING EAST OUT OF THE
GREAT LAKES INTO THE NORTHEASTERN U.S. THIS WILL KEEP UNSETTLED
WEATHER IN THE FORECAST BUT DUE TO AN OVERALL DECREASE IN FORCING
MECHANISM STRENGTH BOTH IN THE LOWER AND MID LEVELS SUNDAY APPEARS
TO OFFER LESS RAINFALL OPPORTUNITY. WHETHER OR NOT THIS COMES TO
PASS HINGES MAINLY ON THE SPEED AT WHICH THE OFFSHORE FRONT RETURNS
AS A WARM FRONT...WHICH IS HIGHLY UNCERTAIN AND POORLY AGREED UPON
BY VARIOUS GUIDANCE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...ACTIVE PATTERN THROUGH THE FIRST HALF OF THE
WEEK AS SOUTHERN STREAM VORT SPAWNS GULF COAST CYCLOGENESIS ON
MONDAY. AS THE HIGHLY AMPLIFIED 500MB TROUGH AXIS MOVES ONLY VERY
SLOWLY EAST THROUGH THE TN VLY...THIS LOW WILL TRAVERSE UP THROUGH
THE SPINE OF THE APPALACHIAN RANGE AND OFF THE MID-ATLANTIC COAST BY
THURSDAY. WARM FRONT STRETCHING FROM THIS LOW WILL PUSH THROUGH THE
CWA VERY EARLY MONDAY LEAVING DEEP AND MOIST SOUTHERLY FLOW ACROSS
THE REGION. ALTHOUGH CLOUD COVER WILL BE QUITE SIGNIFICANT
MON-WED...THE DEEP MOIST FLOW COMBINED WITH MDT STEEP ML LAPSE RATES
THANKS TO 500MB TROUGHING...WILL CREATE SCATTERED SHOWERS AND
THUNDERSTORMS EACH DAY...FAVORED DURING THE AFTNS. COLD FRONT PUSHES
THROUGH ON WEDNESDAY AFTN...LEADING TO A DRIER END OF THE WEEK. CAA
HOLDS OFF UNTIL FRIDAY HOWEVER BEHIND A SECONDARY /DRY/ COLD FRONT.
TEMPS MONDAY WILL BE RIGHT AROUND CLIMO...BUT WARM TO WELL ABOVE FOR
MID-WEEK THANKS TO THE WARM SOUTHERLY FLOW. TEMPS WILL RETURN TO
NORMAL OR SLIGHTLY BELOW FOR THE END OF THE WEEK.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...RADAR IMAGERY INDICATES SEVERAL CLUSTERS OF SHOWERS HAVE
DEVELOPED FROM CHARLOTTE EAST TO SOUTHERN PINES NC...WITH ADDITIONAL
WEAKER SHOWER ACTIVITY JUST SOUTH OF COLUMBIA SC. A GENERAL EASTWARD
MOVEMENT OF THESE SHOWERS SHOULD KEEP THEM AWAY FROM OUR
AIRPORTS...BUT ADDITIONAL SHOWER DEVELOPMENT MAY BRING ACTIVITY IN
THE LBT OR FLO VICINITY IN THE NEXT SEVERAL HOURS. VFR CONDITIONS
SHOULD PREVAIL BUT VSBYS MAY TEMPO FALL TO 3-5SM IN BR THROUGH
DAYBREAK. EXPECT INCREASING CLOUD COVER AFTER DAYBREAK AHEAD OF AN
APPROACHING COLD FRONT...WITH TEMPO SUB-VFR CONDITIONS POSSIBLE AS
SHOWERS INCREASE IN COVERAGE THROUGHOUT THE DAY WITH ISOLATED
AFTERNOON THUNDERSTORMS PSBL. LIGHT SOUTHWEST SFC WINDS THROUGH THE
MORNING HOURS WILL BECOME SOUTH IN THE AFTERNOON...WITH SUSTAINED
WINDS AOB 10 KTS.
EXTENDED OUTLOOK...POTENTIAL MORNING FOG/STRATUS SUNDAY MORNING MAY
REDUCE CIGS/VSBYS TO IFR LEVELS. UNSETTLED WEATHER ASSOCIATED WITH A
STALLED FRONTAL BOUNDARY COULD PRODUCE PERIODS OF TEMPO SUB-VFR
CONDITIONS ACROSS THE AREA THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM SATURDAY...WINDS AND SEAS ARE IN-LINE WITH THE PREVIOUS
FORECAST. NO CHANGES ARE NEEDED. PREVIOUS DISCUSSION FROM 1030 PM
FOLLOWS...
A WEAK COLD FRONT WILL BE APPROACHING THE WATERS FROM THE NW LATE
TONIGHT AND SAT. DO NOT EXPECT ANY SFC PRESSURE GRADIENT TO DEVELOP
AHEAD OF IT...AND AS A RESULT WIND SPEEDS OF 10 KT OR LESS LOOK AOK.
IN ADDITION...A WEAK SFC PRESSURE PATTERN AHEAD OF THE FRONT WILL
ALSO AFFECT THE ILM WATERS OVERNIGHT INTO SATURDAY. COULD GO
VARIABLE IN DIRECTION. AFTER LOOKING AT THE LATEST NAM SFC PRESSURE
PATTERN...WILL INDICATE S OR SW INITIALLY...BECOMING WSW OVERNIGHT.
A NADINE WAVE TRAIN IDENTIFIED BY THE INCREASED PERIODS OF 10-12
SECONDS WILL BE APPROACHING THE ILM WATERS FROM THE ENE
OVERNIGHT...AND LIKELY AFFECTING THE ILM WATERS LATER ON SATURDAY.
SIG. SEAS TONIGHT WILL BASICALLY RUN A SOLID 2 FEET AND COMPRISED
MAINLY FROM AN EASTERLY SWELL AT 8-9 SECOND PERIODS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 PM
FRIDAY...COLD FRONT MOVES INTO THE AREA LATER SATURDAY. THIS WILL
ONLY BRING ABOUT A MARGINAL INCREASE IN THE WINDS AND SEAS FROM
THE PREEXISTING VERY TRANQUIL CONDITIONS THAT HAVE BEEN IN PLACE
FOR SOME TIME. EXPECTING SW WINDS TO INCREASE TO JUST 10 15KT.
BEING LARGELY COAST-PARALLEL THIS WILL BUILD SEAS UP TO 3 FT ALONG
THE OUTER REACHES OF THE 20NM FORECAST ZONES. THE FRONT WILL BE
DECELERATING ANY MAY VERY WELL STALL SOMEWHERE QUITE CLOSE TO THE
COASTAL WATERS FORECAST ZONES...LEADING TO A LITTLE UNCERTAINTY IN
THE WIND AND RESULTING SEAS FORECAST. AT THE CURRENT TIME IT
APPEARS THAT THE BOUNDARY WILL HEAD BACK TO THE NORTH BY SUNDAY
ALLOWING FOR A RETURN OF A SOUTHERLY FLOW...AT LEAST FOR PART IF
NOT ALL OF THE AREA.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...WARM FRONT WILL BE CROSSING THE WATERS AT THE
START OF THE PERIOD...VEERING WINDS TO THE SOUTH WITH INCREASING
SPEEDS. WINDS OF 5-10 KTS FROM THE SE WILL QUICKLY BECOME SOUTHERLY
AT 10-15 KTS BY LATE MONDAY...AND PERSIST THROUGH EARLY WEDNESDAY.
WEAK COLD FRONT APPROACHES EARLY WEDNESDAY AND DISSIPATES OVER THE
WATERS...TURNING WINDS BRIEFLY TO THE SW BEFORE BACKING TO THE SOUTH
ONCE AGAIN AROUND 10 KTS. WINDS WILL TURN TO THE WEST BY THE END OF
THE PERIOD AS A STRONGER SURGE OF DRY AIR PUSHES ACROSS THE WATERS.
SEAS INITIALLY 1-2 FT WILL BUILD QUICKLY TO 2-4 FT BY LATE MONDAY
AND CONTINUE AT THESE AMPLITUDES THROUGH WEDNESDAY THANKS TO THE
STRONG SOUTHERLY WINDS. AS WINDS VEER MORE TO THE WEST LATE
WEDNESDAY...SEAS DECREASE TO 2-3 FT AS HIGHEST WAVES GET PUSHED AWAY
FROM SHORE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...DCH/TRA
SHORT TERM...MBB
LONG TERM...JDW
AVIATION...BJR/TRA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
133 PM EDT SAT SEP 29 2012
.SYNOPSIS...
RIDGE ACROSS THE AREA TODAY WILL BEGIN TO WEAKEN. AN UPPER LEVEL
DISTURBANCE OVER QUEBEC WILL MOVE SOUTH TODAY AND WILL AFFECT THE
AREA LATE TONIGHT AND SUNDAY. HIGH PRESSURE WILL MOVE IN FOR
SUNDAY NIGHT AND PART OF MONDAY BEFORE MOVING NORTH AS LOW
PRESSURE FROM THE GULF OF MEXICO HEADS INTO THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST RADAR AND SATELLITE IMAGERY INDICATE BAND OF WHAT APPEARS
TO BE SHOWERS MOVING SOUTHEAST TOWARD THE AREA CONTINUES TO REMAIN
WEAK. RADAR SHOWS THAT ACTIVITY IS LIKELY VIRGA. A QUICK LOOK OUT
THE WINDOW CONFIRMS THIS SUSPICION. HRRR MODEL HAS ALSO BACKED OFF
ON PRECIPITATION IN THE NORTHEAST AS WELL. SO WILL KEEP AREA DRY
THROUGH THE REST OF THE AFTERNOON.
TEMPERATURES WILL CONTINUE TO CLIMB INTO MAX FORECAST HIGHS FOR
THE DAY. SUNSHINE WILL HELP TO BOOST TEMPERATURES AS WELL. COOLER
READINGS WILL BE IN THE EAST THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE FORECAST IS NOT CLEAR CUT FOR ANY PERIOD. AN UPPER LOW OVER
QUEBEC WILL BE MOVING SOUTH TODAY AND WILL AFFECT THE FORECAST
AREA FOR TONIGHT INTO SUNDAY. THIS RUN OF THE MODELS ARE MUCH
DRIER WITH THIS FEATURE. KEPT CLOSE TO THE PREVIOUS FORECAST. JUST
WENT CHANCE POPS TONIGHT AND THEN LIKELY SUNDAY OVER NE OH AND NW
PA. A BIG QUESTION IS HOW FAR WEST WILL THE THREAT BE. TOLEDO TO
FINDLAY IS ON THE EDGE. BUT WITH THE CIRCULATION AROUND THE LOW
CAN`T RULE OUT SOME LIGHT SHOWERS FOR THAT AREA. CONTINUED WITH
WATERSPOUTS ON THE LAKE SUNDAY AND ADDED THUNDER TO THE LAKE AND
NE OH AND NW PA BASED ON THE LAKE AND 500 MB TEMPERATURE
DIFFERENCE BEING NEAR 43C. SMALL HAIL IS ALSO POSSIBLE...NOT
INCLUDED IN THE ZONES/GRIDS YET. AS THE UPPER LOW MOVES EAST SUNDAY
NIGHT THE THREAT OF SHOWERS WILL DECREASE FROM WEST TO EAST.
HIGH PRESSURE WILL BUILD IN LATE SUNDAY NIGHT AND THEN BEGIN
MOVING NORTH SUNDAY AS LOW PRESSURE HEADS TOWARDS THE FORECAST
AREA FOR MONDAY NIGHT. THIS IS A MODEL CHANGE SO NOT GOING TO
WILD IN BRINGING IN THE SHOWERS TOO QUICKLY...BUT THE TIMING MAY
NEED TO BE ADJUSTED. IT IS POSSIBLE THAT SOME SHOWERS COULD MAKE
IT INTO THE SOUTHERN PORTION OF THE FORECAST AREA LATE MONDAY AFTERNOON.
THE UPPER TROF ASSOCIATED WITH THIS SURFACE LOW WILL BE OVER THE
REGION INTO MID WEEK. THE MODELS HANDLE IT DIFFERENTLY...THE ECMWF
HAS A CLOSED LOW. ON THE EDGE ABOUT THAT...ITS HISTORY THE LAST FEW
WEEKS HAS NOT BEEN REAL GOOD WITH CLOSED LOWS. NONE THE LESS A
THREAT OF SHOWERS WILL EXIST...LIKELY POPS MAY EVEN BE NEEDED.
USED A BLEND OF GUIDANCE FOR THE TEMPERATURES AS THE FORECAST IS
TRICKY WITH ALL THE MODEL DIFFERENCES.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
WEDNESDAY THE GFS AND ECMWF ARE OUT OF SYNC. GFS HAS STRONG LOW
PRESSURE SYSTEM OVER LAKE ERIE...WHILE ECMWF HAS A RIDGE OF HIGH
PRESSURE OVER THE EASTERN LAKES. FOR NOW WILL CONTINUE WITH THE
HPC SOLUTION...WHICH IS THE ECMWF. BOTH MODELS HAVE WEAK RIDGE OVER
THE AREA THURSDAY SO WILL REMOVE ALL MENTION OF PRECIP. TREND FOR
THE TWO MODELS IS SIMILAR FOR THE END OF THE WORK WEEK WITH A LOW
PRESSURE SYSTEM MOVING ACROSS THE LAKES DRAGGING A COLD FRONT ACROSS
THE AREA THURSDAY NIGHT INTO FRIDAY MORNING. GFS IS FASTER OF THE
TWO MODELS...FOR NOW WILL GO WITH THE TIMING OF THE ECMWF WHICH HAS
THE FRONT INTO NW OH BY 12Z FRIDAY AND EAST OF THE AREA BY LATER
AFTERNOON.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
QUIET WEATHER WILL CONTINUE FOR MOST OF THE TAF PERIOD. SOME
PASSING MID LEVEL CLOUDS WILL CONTINUE THROUGH THE EVENING HOURS.
THE LATEST GUIDANCE IS SUGGESTING SOME CU IS POSSIBLE THIS AFTERNOON
IN THE EAST. MOIST LOW LEVEL AIR WILL BEGIN TO ARRIVE LATE
TONIGHT AS AN UPPER LOW APPROACHES FROM THE NE. WILL GRADUALLY
LOWER CIGS OVERNIGHT. BY DAYBREAK WILL NEED A MENTION OF SHOWERS
OVER ABOUT THE EAST 1/3 TO 1/2 OF THE AREA. LOT`S OF MVFR CIGS
CLOSER TO THE LOW CENTER BUT THE NEW GUIDANCE KEEPS THINGS VFR.
DON`T THINK THAT IS REALISTIC AND EXPECT PATCHY MVFR CIGS BY THE
END OF THE PERIOD OVER NE OH AND NW PA. LIGHT W TO NW FLOW WILL
BECOME VARIABLE THIS EVENING AND THEN NE ON SUNDAY MORNING.
.OUTLOOK...NON-VFR PROBABLE SUNDAY AND AGAIN ON TUESDAY IN SHRA.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE LAKE THROUGH SATURDAY. GRADIENT
SHOULD BE WEAK ENOUGH FOR EXPECT LAKE/LAND BREEZES TO DEVELOP BOTH
TODAY AND SATURDAY. WEAK TROUGH/LOW MOVES ACROSS THE LAKE SUNDAY
BUT CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA.
WITH WINDS GENERALLY 10 KNOTS OR LESS. WINDS TURN TO THE
EAST-NORTHEAST MONDAY NIGHT INTO TUESDAY AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE UPPER OHIO VALLEY/LOWER GREAT LAKES. TRACK OF THE
LOW STILL IN DOUBT. WINDS/WAVES COULD APPROACH SMALL CRAFT ADVISORY
CRITERIA. FOR NOW WILL CONTINUE TO MONITOR.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...LOMBARDY
SHORT TERM...KIELTYKA
LONG TERM...DJB
AVIATION...KUBINA
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1240 PM EDT SAT SEP 29 2012
.SYNOPSIS...
RIDGE ACROSS THE AREA TODAY WILL BEGIN TO WEAKEN. AN UPPER LEVEL
DISTURBANCE OVER QUEBEC WILL MOVE SOUTH TODAY AND WILL AFFECT THE
AREA LATE TONIGHT AND SUNDAY. HIGH PRESSURE WILL MOVE IN FOR
SUNDAY NIGHT AND PART OF MONDAY BEFORE MOVING NORTH AS LOW
PRESSURE FROM THE GULF OF MEXICO HEADS INTO THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST RADAR AND SATELLITE IMAGERY INDICATE BAND OF WHAT APPEARS
TO BE SHOWERS MOVING SOUTHEAST TOWARD THE AREA CONTINUES TO REMAIN
WEAK. RADAR SHOWS THAT ACTIVITY IS LIKELY VIRGA. A QUICK LOOK OUT
THE WINDOW CONFIRMS THIS SUSPICION. HRRR MODEL HAS ALSO BACKED OFF
ON PRECIPITATION IN THE NORTHEAST AS WELL. SO WILL KEEP AREA DRY
THROUGH THE REST OF THE AFTERNOON.
TEMPERATURES WILL CONTINUE TO CLIMB INTO MAX FORECAST HIGHS FOR
THE DAY. SUNSHINE WILL HELP TO BOOST TEMPERATURES AS WELL. COOLER
READINGS WILL BE IN THE EAST THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE FORECAST IS NOT CLEAR CUT FOR ANY PERIOD. AN UPPER LOW OVER
QUEBEC WILL BE MOVING SOUTH TODAY AND WILL AFFECT THE FORECAST
AREA FOR TONIGHT INTO SUNDAY. THIS RUN OF THE MODELS ARE MUCH
DRIER WITH THIS FEATURE. KEPT CLOSE TO THE PREVIOUS FORECAST. JUST
WENT CHANCE POPS TONIGHT AND THEN LIKELY SUNDAY OVER NE OH AND NW
PA. A BIG QUESTION IS HOW FAR WEST WILL THE THREAT BE. TOLEDO TO
FINDLAY IS ON THE EDGE. BUT WITH THE CIRCULATION AROUND THE LOW
CAN`T RULE OUT SOME LIGHT SHOWERS FOR THAT AREA. CONTINUED WITH
WATERSPOUTS ON THE LAKE SUNDAY AND ADDED THUNDER TO THE LAKE AND
NE OH AND NW PA BASED ON THE LAKE AND 500 MB TEMPERATURE
DIFFERENCE BEING NEAR 43C. SMALL HAIL IS ALSO POSSIBLE...NOT
INCLUDED IN THE ZONES/GRIDS YET. AS THE UPPER LOW MOVES EAST SUNDAY
NIGHT THE THREAT OF SHOWERS WILL DECREASE FROM WEST TO EAST.
HIGH PRESSURE WILL BUILD IN LATE SUNDAY NIGHT AND THEN BEGIN
MOVING NORTH SUNDAY AS LOW PRESSURE HEADS TOWARDS THE FORECAST
AREA FOR MONDAY NIGHT. THIS IS A MODEL CHANGE SO NOT GOING TO
WILD IN BRINGING IN THE SHOWERS TOO QUICKLY...BUT THE TIMING MAY
NEED TO BE ADJUSTED. IT IS POSSIBLE THAT SOME SHOWERS COULD MAKE
IT INTO THE SOUTHERN PORTION OF THE FORECAST AREA LATE MONDAY AFTERNOON.
THE UPPER TROF ASSOCIATED WITH THIS SURFACE LOW WILL BE OVER THE
REGION INTO MID WEEK. THE MODELS HANDLE IT DIFFERENTLY...THE ECMWF
HAS A CLOSED LOW. ON THE EDGE ABOUT THAT...ITS HISTORY THE LAST FEW
WEEKS HAS NOT BEEN REAL GOOD WITH CLOSED LOWS. NONE THE LESS A
THREAT OF SHOWERS WILL EXIST...LIKELY POPS MAY EVEN BE NEEDED.
USED A BLEND OF GUIDANCE FOR THE TEMPERATURES AS THE FORECAST IS
TRICKY WITH ALL THE MODEL DIFFERENCES.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
WEDNESDAY THE GFS AND ECMWF ARE OUT OF SYNC. GFS HAS STRONG LOW
PRESSURE SYSTEM OVER LAKE ERIE...WHILE ECMWF HAS A RIDGE OF HIGH
PRESSURE OVER THE EASTERN LAKES. FOR NOW WILL CONTINUE WITH THE
HPC SOLUTION...WHICH IS THE ECMWF. BOTH MODELS HAVE WEAK RIDGE OVER
THE AREA THURSDAY SO WILL REMOVE ALL MENTION OF PRECIP. TREND FOR
THE TWO MODELS IS SIMILAR FOR THE END OF THE WORK WEEK WITH A LOW
PRESSURE SYSTEM MOVING ACROSS THE LAKES DRAGGING A COLD FRONT ACROSS
THE AREA THURSDAY NIGHT INTO FRIDAY MORNING. GFS IS FASTER OF THE
TWO MODELS...FOR NOW WILL GO WITH THE TIMING OF THE ECMWF WHICH HAS
THE FRONT INTO NW OH BY 12Z FRIDAY AND EAST OF THE AREA BY LATER
AFTERNOON.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE SATURDAY. CLOUDS WILL THICKEN AND
LOWER THROUGH THE DAY AS UPPER LEVEL TROUGH SWINGS ACROSS THE
AREA. LIGHT S-SW WINDS NEAR LAKESHORE WILL BECOME ONSHORE THIS
AFTERNOON.
SURFACE TROUGH WILL SWING ACROSS EASTERN LAKES SUNDAY...WHICH
SHOULD BRING SOME SHOWERS TO EASTERN HALF OF THE FORECAST AREA.
WILL SEE RAIN SUNDAY BUT CONFIDENCE IS LOW AS TO HOW MUCH. MODEL
RUNS TODAY HAVE BEEN MUCH DRIER THAN PREVIOUS 2 DAYS.
.OUTLOOK...NON-VFR PROBABLE SUNDAY AND AGAIN ON TUESDAY IN SHRA.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE LAKE THROUGH SATURDAY. GRADIENT
SHOULD BE WEAK ENOUGH FOR EXPECT LAKE/LAND BREEZES TO DEVELOP BOTH
TODAY AND SATURDAY. WEAK TROUGH/LOW MOVES ACROSS THE LAKE SUNDAY
BUT CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA.
WITH WINDS GENERALLY 10 KNOTS OR LESS. WINDS TURN TO THE
EAST-NORTHEAST MONDAY NIGHT INTO TUESDAY AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE UPPER OHIO VALLEY/LOWER GREAT LAKES. TRACK OF THE
LOW STILL IN DOUBT. WINDS/WAVES COULD APPROACH SMALL CRAFT ADVISORY
CRITERIA. FOR NOW WILL CONTINUE TO MONITOR.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...LOMBARDY
SHORT TERM...KIELTYKA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
941 AM EDT SAT SEP 29 2012
.SYNOPSIS...
RIDGE ACROSS THE AREA TODAY WILL BEGIN TO WEAKEN. AN UPPER LEVEL
DISTURBANCE OVER QUEBEC WILL MOVE SOUTH TODAY AND WILL AFFECT THE
AREA LATE TONIGHT AND SUNDAY. HIGH PRESSURE WILL MOVE IN FOR
SUNDAY NIGHT AND PART OF MONDAY BEFORE MOVING NORTH AS LOW
PRESSURE FROM THE GULF OF MEXICO HEADS INTO THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK LAZY TROUGH WILL MOVE SOUTH ACROSS THE AREA AND IS
RESPONSIBLE FOR MUCH OF THE CLOUD COVER OVER THE FORECAST AREA
THIS MORNING. A BIT OF CONVECTIVE CLOUD ACTIVITY WAS PRESENT OVER
MICHIGAN AT THIS TIME AND THIS WILL SLIDE SOUTH ACROSS THE AREA.
SO FAR...NO PRECIPITATION WAS ASSOCIATED WITH THIS FEATURE BUT MY
CONCERN IS THAT THERE MAY BE SOME LAKE ENHANCEMENT WITH THE
ACTIVITY FOR THIS AFTERNOON. LATEST HRRR MODEL SUGGESTS SOME
PRECIPITATION OVER NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA THIS
AFTERNOON AWAY FROM THE LAKE FROM THIS FEATURE. WILL KEEP
FORECAST DRY FOR THE TIME BEING AND MONITOR FOR POSSIBLE ADDITION
OF SHOWERS FOR THIS AFTERNOON AND EVENING. REST OF THE AREA SHOULD
REMAIN DRY THROUGH THE DAY.
MADE SOME MINOR ADJUSTMENTS TO HOURLY TEMPERATURES BUT MAX
TEMPERATURES APPEAR TO BE ON TARGET AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE FORECAST IS NOT CLEAR CUT FOR ANY PERIOD. AN UPPER LOW OVER
QUEBEC WILL BE MOVING SOUTH TODAY AND WILL AFFECT THE FORECAST
AREA FOR TONIGHT INTO SUNDAY. THIS RUN OF THE MODELS ARE MUCH
DRIER WITH THIS FEATURE. KEPT CLOSE TO THE PREVIOUS FORECAST. JUST
WENT CHANCE POPS TONIGHT AND THEN LIKELY SUNDAY OVER NE OH AND NW
PA. A BIG QUESTION IS HOW FAR WEST WILL THE THREAT BE. TOLEDO TO
FINDLAY IS ON THE EDGE. BUT WITH THE CIRCULATION AROUND THE LOW
CAN`T RULE OUT SOME LIGHT SHOWERS FOR THAT AREA. CONTINUED WITH
WATERSPOUTS ON THE LAKE SUNDAY AND ADDED THUNDER TO THE LAKE AND
NE OH AND NW PA BASED ON THE LAKE AND 500 MB TEMPERATURE
DIFFERENCE BEING NEAR 43C. SMALL HAIL IS ALSO POSSIBLE...NOT
INCLUDED IN THE ZONES/GRIDS YET. AS THE UPPER LOW MOVES EAST SUNDAY
NIGHT THE THREAT OF SHOWERS WILL DECREASE FROM WEST TO EAST.
HIGH PRESSURE WILL BUILD IN LATE SUNDAY NIGHT AND THEN BEGIN
MOVING NORTH SUNDAY AS LOW PRESSURE HEADS TOWARDS THE FORECAST
AREA FOR MONDAY NIGHT. THIS IS A MODEL CHANGE SO NOT GOING TO
WILD IN BRINGING IN THE SHOWERS TOO QUICKLY...BUT THE TIMING MAY
NEED TO BE ADJUSTED. IT IS POSSIBLE THAT SOME SHOWERS COULD MAKE
IT INTO THE SOUTHERN PORTION OF THE FORECAST AREA LATE MONDAY AFTERNOON.
THE UPPER TROF ASSOCIATED WITH THIS SURFACE LOW WILL BE OVER THE
REGION INTO MID WEEK. THE MODELS HANDLE IT DIFFERENTLY...THE ECMWF
HAS A CLOSED LOW. ON THE EDGE ABOUT THAT...ITS HISTORY THE LAST FEW
WEEKS HAS NOT BEEN REAL GOOD WITH CLOSED LOWS. NONE THE LESS A
THREAT OF SHOWERS WILL EXIST...LIKELY POPS MAY EVEN BE NEEDED.
USED A BLEND OF GUIDANCE FOR THE TEMPERATURES AS THE FORECAST IS
TRICKY WITH ALL THE MODEL DIFFERENCES.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
WEDNESDAY THE GFS AND ECMWF ARE OUT OF SYNC. GFS HAS STRONG LOW
PRESSURE SYSTEM OVER LAKE ERIE...WHILE ECMWF HAS A RIDGE OF HIGH
PRESSURE OVER THE EASTERN LAKES. FOR NOW WILL CONTINUE WITH THE
HPC SOLUTION...WHICH IS THE ECMWF. BOTH MODELS HAVE WEAK RIDGE OVER
THE AREA THURSDAY SO WILL REMOVE ALL MENTION OF PRECIP. TREND FOR
THE TWO MODELS IS SIMILAR FOR THE END OF THE WORK WEEK WITH A LOW
PRESSURE SYSTEM MOVING ACROSS THE LAKES DRAGGING A COLD FRONT ACROSS
THE AREA THURSDAY NIGHT INTO FRIDAY MORNING. GFS IS FASTER OF THE
TWO MODELS...FOR NOW WILL GO WITH THE TIMING OF THE ECMWF WHICH HAS
THE FRONT INTO NW OH BY 12Z FRIDAY AND EAST OF THE AREA BY LATER
AFTERNOON.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL CONTINUE SATURDAY. CLOUDS WILL THICKEN AND
LOWER THROUGH THE DAY AS UPPER LEVEL TROUGH SWINGS ACROSS THE
AREA. LIGHT S-SW WINDS NEAR LAKESHORE WILL BECOME ONSHORE THIS
AFTERNOON.
SURFACE TROUGH WILL SWING ACROSS EASTERN LAKES SUNDAY...WHICH
SHOULD BRING SOME SHOWERS TO EASTERN HALF OF THE FORECAST AREA.
WILL SEE RAIN SUNDAY BUT CONFIDENCE IS LOW AS TO HOW MUCH. MODEL
RUNS TODAY HAVE BEEN MUCH DRIER THAN PREVIOUS 2 DAYS.
.OUTLOOK...NON-VFR PROBABLE SUNDAY AND AGAIN ON TUESDAY IN SHRA.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE LAKE THROUGH SATURDAY. GRADIENT
SHOULD BE WEAK ENOUGH FOR EXPECT LAKE/LAND BREEZES TO DEVELOP BOTH
TODAY AND SATURDAY. WEAK TROUGH/LOW MOVES ACROSS THE LAKE SUNDAY
BUT CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA.
WITH WINDS GENERALLY 10 KNOTS OR LESS. WINDS TURN TO THE
EAST-NORTHEAST MONDAY NIGHT INTO TUESDAY AS A LOW PRESSURE SYSTEM
MOVES ACROSS THE UPPER OHIO VALLEY/LOWER GREAT LAKES. TRACK OF THE
LOW STILL IN DOUBT. WINDS/WAVES COULD APPROACH SMALL CRAFT ADVISORY
CRITERIA. FOR NOW WILL CONTINUE TO MONITOR.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...LOMBARDY
SHORT TERM...KIELTYKA
LONG TERM...DJB
AVIATION...DJB
MARINE...DJB
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
810 PM EDT SUN SEP 30 2012
.SYNOPSIS...
A DEEP UPPER LOW PRESSURE SYSTEM WILL ROTATE THROUGH NORTHERN
PENNSYLVANIA THIS AFTERNOON...THEN QUICKLY LIFT AWAY FROM THE
AREA TONIGHT. HIGH PRESSURE WILL BRIEFLY VISIT THE REGION ON
MONDAY. WET WEATHER WILL RETURN TO THE KEYSTONE STATE MONDAY NIGHT
THROUGH TUESDAY AS A WAVE OF LOW PRESSURE EJECTS NORTHWARD FROM
THE CENTRAL GULF STATES.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
NMRS INSTABILITY SHOWERS NOW EVIDENT ON RADAR ACRS MUCH OF THE
CWA...DRIVEN BY THE HEATING OF THE DAY /ALBEIT MODEST/ UNDER H5-H7
COLD POOL OF -15C. THIS IS RESULTING IN MID-LVL LAPSE RATES
AROUND 7 C/KM -- A VERY STRONG SIGNAL FOR INSTABILITY SHOWERS.
SMALL HAIL WILL BE POSSIBLE IN THE MORE ROBUST...LOW-TOPPED
CONVECTIVE CELLS. THE LATEST HRRR HAD DONE QUITE WELL WITH THE
SHOWER PLACEMENT THUS FAR...WITH THE GREATEST CONCENTRATION OF
SHOWER ACTIVITY ALONG I-80 AND OVR THE LAURELS/S-CENTRAL MTNS. THE
BAND OF CONVECTIVE SHOWERS CURRENTLY OVR THE S-CENTRAL MTNS SHOULD
REACH THE LWR SUSQ VLY METRO AREAS AROUND 20Z.
BKN-OVC CUMULUS/STRATOCU SHOULD START TO FIZZLE OUT THIS EVE WITH
PARTIAL CLEARING EXPECTED BY LATE TONIGHT. BY THE SAME TOKEN...EXPECT
INSTABILITY SHOWERS/ISOLD TSRA TO QUICKLY FADE AND EVENTUALLY
DISSIPATE WITH THE LOSS OF HEATING SHORTLY AFT 00Z. LLVL MSTR MAY
GET TRAPPED BLW INVERSION AND RESULT IN LOW STRATUS/FOG INTO EARLY
MONDAY MORNING...ESP ACRS THE ALLEGHENIES GIVEN WEAK WNW UPSLOPE.
HAVE ADDED MENTION OF FG LATE TONIGHT WITH THE FINAL AFTN UPDATE.
OTHERWISE...NO MAJOR CHANGES TO NEAR TERM FCST. OVERNIGHT LOWS
WILL BE NEAR SEASONAL NORMALS...WITH THE COLDEST READINGS OVR THE
WRN MTNS WHERE THE BEST RADIATIONAL COOLING SHOULD OCCUR.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AFTER SOME PATCHY EARLY MORNING FOG/LOW CLOUDS...SFC RIDGE WILL
BISECT THE STATE...IN BETWEEN DEPARTING NRN STREAM UPPER TROUGH/LOW
LIFTING NWD ACRS NRN NEW ENGLAND AND DEVELOPING SRN STREAM WAVE OVR
MS/AL. EXPECT AN INCREASE IN MID-HIGH CLOUDS IN ADVANCE OF THE SRN
SYSTEM LATE IN THE DAY...AS IT MOVES NWD INTO THE TN VLY BY 00Z
TUE. HIGHS WILL BE QUITE PLEASANT IN THE 60S TO LOWER 70S NORTH TO
SOUTH.
MDLS IN DECENT AGREEMENT IN MOVG THE SFC WAVE INTO TN/KY BY THE
END OF THE PERIOD. ANOMALOUS SLY LLJ WILL SUPPORT ROBUST NWD MSTR
FLUX INTO THE AREA MON NGT...WITH PWATS SURGING TO +2-3SD BY 12Z
TUE. ANOTHER INTERESTING FEATURE IS PERHAPS A DUEL MSTR FEED FM
THE GOMEX AND ATM RIVER EMANATING FM THE BAHAMAS. THE LATTER
SHOULD BECOME THE MAIN SOURCE OF HI PWATS INTO TUES. THE 12Z
MODELS STILL DISPLAY SOME DETAIL DIFFS WITH THIS SYS AND THEREFORE
ONLY MADE MINOR TWEAKS TO THE SHORT TERM FCST FOR THE DY2 FINALS.
HOWEVER WITH SUPPORT FROM THE 12Z GEFS/09Z SREF...STILL FEEL THAT
HIGHER POPS ARE JUSTIFIED /ESPECIALLY FROM 06-12Z TUES/ GIVEN THE
STG WAA/ISENT LIFT AND MSTR TRANSPORT INTO THE REGION.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
BY TUES...LARGE SCALE PATTERN WILL FEATURE HIGH AMPLITUDE TROUGH
WITH UPPER LOW CENTERED NEAR MISSOURI. SFC LOW WILL BE LIFTING
INTO THE OHIO VALLEY DRAGGING AN OCCLUDED FRONT THROUGH PA LATER
TUE OR TUE NIGHT. THE SHORT RANGE GUIDANCE SHOWS ERODING
STABILITY AND SUGGESTS THE POSSIBILITY OF SOME CONVECTION AS THE
FRONT GETS CLOSER TUES...MAINLY ACROSS THE SOUTHERN HALF. QPF ON
TUE LOOKS TO BE AROUND 0.25 ON AVERAGE...BUT HIGHER AMOUNTS ARE
POSS.
SOAKING RAIN CONTINUES INTO TUE NIGHT/EARLY WED AS SOUTHERLY FLOW
ALOFT RIDES OVER THE SFC LOW...AND SHORTWAVE ENERGY SLIDES AROUND
BASE OF TROUGH BEFORE EJECTING INTO OHIO VALLEY WED. MODELS STILL
HINTING AT WEAK SECONDARY SFC WAVE DEVELOPMENT TO OUR SE...WHICH
MAY PEEL POTENTIAL FOR 1 INCH QPFS AWAY FROM PA RESULTING IN A
WIDESPREAD LIGHT TO MODERATE RAIN...AND A MINIMAL FLOOD THREAT AT
THIS TIME.
AFTER THE SFC LOW/FRONT CLEARS THE AREA...THE UPPER LOW WILL THEN
PUSH THROUGH WED/WED NIGHT...KEEPING MENTION OF SHOWERS IN THE
FORECAST - MAINLY IN THE WEST AS DRY SLOT APPEARS TO WORK IN WITH
RIDGE NOSING IN FROM THE SOUTH.
THU AND FRI WILL SEE SFC RIDGING AND W/SW UPPER FLOW...WHICH
SHOULD KEEP THE REGION DRY WITH NEAR/SLIGHTLY ABOVE NORMAL TEMPS.
MODELS CONTINUE TO PRODUCE DIVERGING FORECASTS FOR THE WEEKEND.
THE GEFS/GFS AND CANADIAN MODELS SHOW AN APPROACHING ALBEIT FADING
FRONT LATER FRIDAY WITH THE PARENT UPPER SHORTWAVE WANTING TO
SHEAR OUT WELL NORTH AND WEST OF HERE. THE ECMWF /UNUSUALLY/
CONTINUES TO BE AN OUTLIER...HOLDING ITS UPPER ENERGY BACK
RESULTING IN A BROAD WSW FLOW EVENTUALLY ESTABLISHING OVER THE GR
LAKES AND NERN US. THIS RESULTS IN THE MODEL DEVELOPING A SLOW
MOVING WAVY ANA-FRONT THAT APPROACHES THE AREA FOR THE WEEKEND.
TOUGH TO EVEN LEAN FORECAST ONE WAY OR THE OTHER WITH SUCH
DIFFERENCE IN GUIDANCE...SO HAD TO KEEP LOW POPS ACROSS SEVERAL
PERIODS...THOUGH PAINTED HIGHEST POPS ON SAT. FOR
TEMPS...GRADUALLY OOZED COOLER TEMPERATURES INTO THE REGION FROM
SAT INTO MON.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
SCT SHRA RAPIDLY DISSIPATING ACROSS CENTRAL PA WITH LOSS OF
HEATING. SFC HIGH PRES WILL SLIDE INTO THE REGION FROM THE UPPER
OH VLY OVERNIGHT...BRINGING MCLEAR SKIES AND A LGT WIND. PATCHY
FOG APPEARS LIKELY TO DEVELOP LATE TONIGHT...ESP ACROSS THE
WESTERN HALF OF THE STATE...WHERE PRES GRADIENT/WINDS WILL BE
WEAKEST. TAKING INTO ACCOUNT CLIMATOLOGY AND WHERE RAIN HAS FALLEN
TODAY...IT APPEARS MOST AIRFIELDS WILL LIKELY EXPERIENCE A PERIOD
OF LOW VSBYS BTWN 09Z-13Z. LACK OF RAINFALL TDY AT UNV AND
UNFAVORABLE CLIMATOLOGY AT MDT WOULD SUGGEST THAT THOSE AIRFIELDS
MAY ESCAPE SIG VIS RESTRICTIONS.
ANY EARLY FOG SHOULD BURN OFF BY ARND 13Z. FOR THE REST OF THE
DAY...A NEAR CERTAINTY OF VFR CONDS AND LGT WINDS...AS SFC HIGH
REMAINS OVR THE REGION. LOW PRES LIFTING NORTH INTO THE OHIO
VALLEY WILL BRING LOWERING CLOUDS AND CHC OF RAIN MON NIGHT.
OUTLOOK...
TUE...RAIN/LOW CIGS POSSIBLE.
WED...AM RAIN/LOW CIGS/FOG POSSIBLE.
THU-FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DEVOIR/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1023 PM CDT SUN SEP 30 2012
.UPDATE...
TO ADD SLIGHT CHANCE POPS AND LOWER OVERNIGHT LOW TEMPERATURES...
&&
.DISCUSSION...
DISTURBANCES CONTINUE TO ROTATE AROUND AN UPPER LEVEL LOW CENTERED
OVER THE ARKLATEX REGION. THIS DISTURBANCES ARE PRODUCING
SCATTERED SHOWERS AND THUNDERSTORMS MOVING FROM NORTH TO
SOUTH...ACROSS THE TEXAS PANHANDLE AND PARTS OF WEST TEXAS. THERE
IS CURRENTLY A LINE OF THUNDERSTORMS OVER THE PERMIAN BASIN...AND
THIS WILL LIKELY CLIP PARTS OF CROCKETT COUNTY. IN
ADDITION...ANOTHER AREA OF THUNDERSTORMS IS QUICKLY MOVING SOUTH
THROUGH THE PANHANDLE. THIS MAY AFFECT...AT LEAST THE WESTERN
PARTS OF THE CWA...AND THIS IS REFLECTED IN THE LATEST HRRR MODEL
RUN. I ADDED IN A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
OVERNIGHT...FOR MAINLY THE WESTERN HALF OF THE AREA.
FINALLY...I LOWERED TEMPERATURES BY A FEW DEGREES ACROSS THE
AREA...AS WINDS REMAIN LIGHT AND DEWPOINT TEMPERATURES DROP INTO THE
MID AND UPPER 50S. OTHERWISE...NO OTHER CHANGES NEEDED AT THIS
TIME.
&&
.PREV DISCUSSION... /ISSUED 706 PM CDT SUN SEP 30 2012/
DISCUSSION...
SEE AVIATION DISCUSSION BELOW.
AVIATION...
VFR CONDITIONS WILL PREVAIL OVERNIGHT. BBD MAY SEE A VICINITY
SHOWER OVER THE NEXT TWO HOURS...AND SOME FOG DEVELOPING AFTER 09Z
FOR ABOUT TWO HOURS. HIGH RESOLUTION RAP MODEL BRINGS THE ACTIVITY
IN THE PANHANDLE NEAR THE WESTERN TERMINALS LATER TONIGHT...BUT DO
NOT HAVE CONFIDENCE ENOUGH TO MENTION IN THE TAFS FOR SJT AND SOA.
MODELS DEVELOP SHOWERS AGAIN TOMORROW AFTERNOON...SO HAVE INCLUDED
VCSH FOR ABI...SOA...AND SJT.
PREV DISCUSSION... /ISSUED 346 PM CDT SUN SEP 30 2012/
SHORT TERM...
CLOUD COVERAGE IS ON A DECREASING TREND AND EXPECT THIS TO CONTINUE
THROUGH THIS EVENING ACROSS OUR AREA. SOMEWHAT GUSTY NORTH WINDS
WILL DIMINISH AND BECOME LIGHT BY EARLY TONIGHT. THE CHANCE FOR
CONVECTION WHICH DEVELOPS IN NORTHEASTERN NEW MEXICO/SOUTHEASTERN
COLORADO TO SURVIVE LONG ENOUGH TO MOVE SOUTH-SOUTHEAST INTO OUR
AREA LATER TONIGHT LOOKS TOO LOW TO INCLUDE A MENTIONABLE POP...SO
WILL LEAVE OUT FOR NOW. ANTICIPATE THAT SOME MIDDLE AND UPPER LEVEL
CLOUDS /FROM UPSTREAM CONVECTIVE DEVELOPMENT/ WILL TRAVERSE OUR
COUNTIES OVERNIGHT. CANNOT RULE OUT A POSSIBILITY FOR SOME PATCHY FOG
DEVELOPMENT LATER TONIGHT WITH WEAK WINDS AND TEMPERATURES COOLING
TO NEAR THE DEWPOINT VALUES. WITH THIS BEING THE SECOND NIGHT REMOVED
FROM THE RAINFALL EVENT HOWEVER...AND WITH SOME INCREASE IN CLOUD
COVER POSSIBLE...NOT ENOUGH CONFIDENCE TO MENTION IN THE FORECAST AT
THIS TIME. THIS CAN BE MONITORED THIS EVENING.
ON MONDAY...HAVE INCLUDED A SLIGHT CHANCE POP FOR SHOWERS AND
THUNDERSTORMS ACROSS MOST OF OUR AREA. AN UPPER JET MAX WILL DIVE
SOUTH THROUGH THE HIGH PLAINS AROUND THE BACK SIDE OF AN UPPER
TROUGH...PLACING OUR AREA IN THE LEFT FRONT QUADRANT DURING THE
AFTERNOON. DURING THAT TIME...COLD AIR ADVECTION ALOFT /500MB
TEMPERATURES DROPPING TO MINUS 13 TO MINUS 15 DEG C / WILL BE
COINCIDENT WITH SURFACE TEMPERATURES WARMING TO OR ABOVE 80 DEGREES.
LONG TERM...
THIS WEEK WILL FEATURE SEASONABLE TEMPERATURES AS THE UPPER LEVEL
JET STREAM CONTINUES TO DIVE SOUTH INTO THE U.S. PUSHING COLD FRONTS
INTO WC TX. THIS PATTERN CAN MAKE IT VERY DIFFICULT TO PREDICT
TEMPERATURES THOUGH. THE CANADIAN/GFS/AND ECMWF ALL INDICATE AN
AMPLIFICATION IN THE UPPER RIDGE ACROSS ACROSS THE WESTERN PROVINCES
OF CANADA THIS WEEK. THIS TYPE OF PATTERN IS VERY FAVORABLE FOR
AT LEAST A COUPLE OF SURGES OF CANADIAN AIRMASSES TO PLUNGE SOUTH
INTO THE U.S. AND EVENTUALLY WC TX.
AFTER A BEAUTIFUL WEATHER DAY ON TUESDAY...A WEAK SURFACE HIGH
PRESSURE SYSTEM WILL MOVE EAST OF THE REGION TUESDAY NIGHT AND
RESULT IN A WARM SOUTHERLY FLOW INTO WEDNESDAY WHEN TEMPERATURES
COULD REACH THE MID TO UPPER 80S. AS A STRONG SHORTWAVE TROUGH MOVES
ACROSS THE CENTRAL PLAINS WEDNESDAY NIGHT...IT WILL SEND A CANADIAN
COLD FRONT INTO THE AREA ON THURSDAY. FOR THIS REASON...TRENDED
COOLER FOR THE BIG COUNTRY ON THURSDAY AND FORECASTED HIGHS MAY BE
SLIGHTLY COOLER.
AFTER A SLIGHT WARMING TREND ON FRIDAY...THE NEXT CANADIAN FRONT
IS PROGGED TO ENTER THE NORTHERN PART OF THE BIG COUNTRY SATURDAY
MORNING...AND THEN SWEEP THROUGH THE REGION DURING THE DAY. A FEW
THUNDERSTORMS MAY FORM ALONG THE FRONT. THE MODELS PROG STRATIFORM
PRECIPITATION TO DEVELOP SATURDAY NIGHT INTO SUNDAY AS THE RIGHT
REAR ENTRANCE OF A JET MAX CAUSES AN ISENTROPIC WARM AIR ADVECTION
PATTERN TO DEVELOP ATOP THE COLD AIR.
THE CHALLENGE WITH THIS FRONT WILL BE HIGH TEMPERATURES ON
SUNDAY. SINCE THERE IS STILL QUITE A BIT OF UNCERTAINTY....WILL
START WITH HIGHS NEAR 70. BUT THESE TEMPS MAY BE COOLER. WENT
AHEAD AND ADDED SLIGHT CHANCE POPS FOR LIGHT RAIN AND MOSTLY
CLOUDY SKIES FOR SATURDAY NIGHT INTO SUNDAY.
26
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 58 81 54 77 56 / 10 20 5 5 0
SAN ANGELO 58 82 56 78 56 / 20 20 10 0 0
JUNCTION 58 82 53 81 53 / 10 20 10 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
706 PM CDT SUN SEP 30 2012
.DISCUSSION...
SEE AVIATION DISCUSSION BELOW.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL OVERNIGHT. BBD MAY SEE A VICINITY
SHOWER OVER THE NEXT TWO HOURS...AND SOME FOG DEVELOPING AFTER 09Z
FOR ABOUT TWO HOURS. HIGH RESOLUTION RAP MODEL BRINGS THE ACTIVITY
IN THE PANHANDLE NEAR THE WESTERN TERMINALS LATER TONIGHT...BUT DO
NOT HAVE CONFIDENCE ENOUGH TO MENTION IN THE TAFS FOR SJT AND SOA.
MODELS DEVELOP SHOWERS AGAIN TOMORROW AFTERNOON...SO HAVE INCLUDED
VCSH FOR ABI...SOA...AND SJT.
&&
.PREV DISCUSSION... /ISSUED 346 PM CDT SUN SEP 30 2012/
SHORT TERM...
CLOUD COVERAGE IS ON A DECREASING TREND AND EXPECT THIS TO CONTINUE
THROUGH THIS EVENING ACROSS OUR AREA. SOMEWHAT GUSTY NORTH WINDS
WILL DIMINISH AND BECOME LIGHT BY EARLY TONIGHT. THE CHANCE FOR
CONVECTION WHICH DEVELOPS IN NORTHEASTERN NEW MEXICO/SOUTHEASTERN
COLORADO TO SURVIVE LONG ENOUGH TO MOVE SOUTH-SOUTHEAST INTO OUR
AREA LATER TONIGHT LOOKS TOO LOW TO INCLUDE A MENTIONABLE POP...SO
WILL LEAVE OUT FOR NOW. ANTICIPATE THAT SOME MIDDLE AND UPPER LEVEL
CLOUDS /FROM UPSTREAM CONVECTIVE DEVELOPMENT/ WILL TRAVERSE OUR
COUNTIES OVERNIGHT. CANNOT RULE OUT A POSSIBILITY FOR SOME PATCHY FOG
DEVELOPMENT LATER TONIGHT WITH WEAK WINDS AND TEMPERATURES COOLING
TO NEAR THE DEWPOINT VALUES. WITH THIS BEING THE SECOND NIGHT REMOVED
FROM THE RAINFALL EVENT HOWEVER...AND WITH SOME INCREASE IN CLOUD
COVER POSSIBLE...NOT ENOUGH CONFIDENCE TO MENTION IN THE FORECAST AT
THIS TIME. THIS CAN BE MONITORED THIS EVENING.
ON MONDAY...HAVE INCLUDED A SLIGHT CHANCE POP FOR SHOWERS AND
THUNDERSTORMS ACROSS MOST OF OUR AREA. AN UPPER JET MAX WILL DIVE
SOUTH THROUGH THE HIGH PLAINS AROUND THE BACK SIDE OF AN UPPER
TROUGH...PLACING OUR AREA IN THE LEFT FRONT QUADRANT DURING THE
AFTERNOON. DURING THAT TIME...COLD AIR ADVECTION ALOFT /500MB
TEMPERATURES DROPPING TO MINUS 13 TO MINUS 15 DEG C / WILL BE
COINCIDENT WITH SURFACE TEMPERATURES WARMING TO OR ABOVE 80 DEGREES.
LONG TERM...
THIS WEEK WILL FEATURE SEASONABLE TEMPERATURES AS THE UPPER LEVEL
JET STREAM CONTINUES TO DIVE SOUTH INTO THE U.S. PUSHING COLD FRONTS
INTO WC TX. THIS PATTERN CAN MAKE IT VERY DIFFICULT TO PREDICT
TEMPERATURES THOUGH. THE CANADIAN/GFS/AND ECMWF ALL INDICATE AN
AMPLIFICATION IN THE UPPER RIDGE ACROSS ACROSS THE WESTERN PROVINCES
OF CANADA THIS WEEK. THIS TYPE OF PATTERN IS VERY FAVORABLE FOR
AT LEAST A COUPLE OF SURGES OF CANADIAN AIRMASSES TO PLUNGE SOUTH
INTO THE U.S. AND EVENTUALLY WC TX.
AFTER A BEAUTIFUL WEATHER DAY ON TUESDAY...A WEAK SURFACE HIGH
PRESSURE SYSTEM WILL MOVE EAST OF THE REGION TUESDAY NIGHT AND
RESULT IN A WARM SOUTHERLY FLOW INTO WEDNESDAY WHEN TEMPERATURES
COULD REACH THE MID TO UPPER 80S. AS A STRONG SHORTWAVE TROUGH MOVES
ACROSS THE CENTRAL PLAINS WEDNESDAY NIGHT...IT WILL SEND A CANADIAN
COLD FRONT INTO THE AREA ON THURSDAY. FOR THIS REASON...TRENDED
COOLER FOR THE BIG COUNTRY ON THURSDAY AND FORECASTED HIGHS MAY BE
SLIGHTLY COOLER.
AFTER A SLIGHT WARMING TREND ON FRIDAY...THE NEXT CANADIAN FRONT
IS PROGGED TO ENTER THE NORTHERN PART OF THE BIG COUNTRY SATURDAY
MORNING...AND THEN SWEEP THROUGH THE REGION DURING THE DAY. A FEW
THUNDERSTORMS MAY FORM ALONG THE FRONT. THE MODELS PROG STRATIFORM
PRECIPITATION TO DEVELOP SATURDAY NIGHT INTO SUNDAY AS THE RIGHT
REAR ENTRANCE OF A JET MAX CAUSES AN ISENTROPIC WARM AIR ADVECTION
PATTERN TO DEVELOP ATOP THE COLD AIR.
THE CHALLENGE WITH THIS FRONT WILL BE HIGH TEMPERATURES ON
SUNDAY. SINCE THERE IS STILL QUITE A BIT OF UNCERTAINTY....WILL
START WITH HIGHS NEAR 70. BUT THESE TEMPS MAY BE COOLER. WENT
AHEAD AND ADDED SLIGHT CHANCE POPS FOR LIGHT RAIN AND MOSTLY
CLOUDY SKIES FOR SATURDAY NIGHT INTO SUNDAY.
26
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 59 81 54 77 56 / 10 20 5 5 0
SAN ANGELO 58 82 56 78 56 / 10 20 10 0 0
JUNCTION 57 82 53 81 53 / 5 20 10 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
REIMER
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
640 PM CDT SUN SEP 30 2012
.AVIATION...
/00 UTC TAFS/ ONGOING CONVECTION CONTINUES TO MOVE SOUTH ACROSS THE
WESTERN TX PANHANDLE...AND ARE NOT EXPECTED TO IMPACT KAMA/KDHT.
ADDITIONAL SHOWERS AND THUNDERSTORMS WERE DEVELOPING IN SOUTHWESTERN
KS AND ARE ALSO MOVING TO THE SOUTH. HAVE LEFT OUT MENTION OF TSRA IN
AT KGUY AS LATEST HRRR AND TT WRF SHOW THESE STORMS WILL MOVE EAST OF
THE TERMINAL. WILL CONTINUE TO MONITOR AND AMEND AS NECESSARY. LIGHT
AND VARIABLE WINDS THIS EVENING WILL SHIFT TO THE NORTH BEHIND A WEAK
COLD FRONT THAT WILL MOVE ACROSS THE TERMINALS THIS EVENING. WINDS
WILL REMAIN OUT OF THE NORTH THROUGH THE REMAINDER OF THE FORECAST
BUT WILL INCREASE TO AROUND 20-25 KTS SUSTAINED WITH GUSTS UP TO 35 KTS
AS THE PRESSURE GRADIENT TIGHTENS BEHIND THIS FRONT. VFR CONDITIONS
ARE EXPECTED THROUGH THE VALID TAF FORECAST PERIOD.
CLK
&&
.PREV DISCUSSION... /ISSUED 337 PM CDT SUN SEP 30 2012/
DISCUSSION...
PRECIPITATION CHANCES THROUGH TOMORROW AND COOLER TEMPERATURES LATE
WEEK ARE THE MAIN FORECAST CONCERNS.
ISOLATED TO SCATTERED THUNDERSTORMS CONTINUE TO DEVELOP FROM THE
NORTHWEST TX PANHANDLE AND NORTHEAST NM...NORTH INTO THE CENTRAL HIGH
PLAINS. A MID-LEVEL SHORTWAVE DIVING DOWN WITHIN THE NORTH/NORTHWEST
FLOW ALOFT WAS ACTING ON AN INCREASINGLY UNSTABLE AIRMASS TO TRIGGER
THIS CONVECTION. A WEAK SURFACE TROUGH IS ALSO DRAPED NORTH/NORTHEAST
TO SOUTH/SOUTHWEST ACROSS THE AREA...WHICH MAY ALSO HELP TO FOCUS
CONVECTION THIS AFTERNOON AND EVENING. LAPS/RUC ANALYSIS DATA SHOW
A CORRIDOR OF 1000-1500 MLCAPES ACROSS THE PANHANDLES...WITH FAIRLY
WEAK DEEP LAYER SHEAR IN THE 20-30 KT RANGE. GIVEN THIS
COMBINATION...COULD SEE A FEW STRONG TO MARGINALLY SEVERE STORMS
THROUGH THE EVENING HOURS. PRECIPITATION IS LIKELY TO WANE LATE THIS
EVENING...BUT WITH THE NOSE OF THE UPPER JET CURRENTLY DIGGING SOUTH
ALONG THE LEE OF THE ROCKIES DRAWING CLOSER TO THE PANHANDLES
OVERNIGHT...CAN/T RULE OUT A FEW LINGERING SHOWERS/WEAK THUNDERSTORMS
ACROSS THE EASTERN HALF OF THE AREA OVERNIGHT.
THIS DIGGING UPPER JET AND ANOTHER SHORTWAVE TROUGH DIVING SOUTH
ACROSS THE PLAINS WILL HELP TO SEND A WEAK COLD FRONT SOUTH THROUGH
THE CWA LATE TONIGHT INTO MONDAY MORNING. WON/T SEE MUCH OF A COOL
DOWN BEHIND THE FRONT...BUT BREEZY NORTHERLY WINDS WILL DEVELOP
BEHIND THE FRONT. THE LFQ OF AN 80-100 KT NORTH/SOUTH UPPER JET WILL
SLIDE ACROSS THE PANHANDLES ON MONDAY...ACTING WITH SOME LOW TO MID-
LEVEL FRONTOGENESIS TO SUPPORT A CHANCE OF A FEW SHOWERS AND WEAK
THUNDERSTORMS /AS INSTABILITY REMAINS WEAK/ ACROSS MOST OF THE CWA.
ANY PRECIPITATION WILL SLIDE EAST/SOUTHEAST OF THE AREA BY EARLY
MONDAY EVENING.
DRY AND WARMING CONDITIONS ARE THEN ON TAP TUESDAY AND WEDNESDAY
IN BETWEEN COLD FRONTS. A DEEPENING LEE TROUGH AHEAD OF THE NEXT UPPER
TROUGH DIGGING ACROSS THE NORTHERN AND CENTRAL ROCKIES WILL HELP
TEMPS REBOUND INTO THE 80S BY WEDNESDAY. NEXT COLD FRONT WILL PUSH
THROUGH WEDNESDAY NIGHT AS THE PARENT UPPER TROUGH PUSHES ACROSS THE
NORTHERN AND CENTRAL PLAINS...KNOCKING HIGHS BACK INTO THE 60S AND
70S ON THURSDAY. NOT EXPECTING ANY PRECIP WITH THE FRONT AS MOISTURE
WILL BE LACKING AND UPPER DYNAMICS STAY TO OUR NORTH.
FRIDAY WILL BRING A BRIEF REBOUND IN TEMPS AHEAD OF THE NEXT STRONGER
COLD FRONT EXPECTED TO PLOW THROUGH FRIDAY NIGHT. AS THE ASSOCIATED
UPPER TROUGH/JET DIG ACROSS THE NORTHERN AND CENTRAL
PLAINS...FORCING FROM THE RRQ OF THE UPPER JET WILL GRAZE THE
NORTHEAST CWA FRIDAY NIGHT...POSSIBLE TEAMING WITH THE FRONT TO
BRING A FEW SHOWERS TO THIS PORTION OF THE AREA. BEYOND THAT...RAIN
CHANCES CURRENTLY LOOK MINIMAL FOR THE WEEKEND AS SURFACE HIGH
PRESSURE AND DRIER AIR BUILD IN BEHIND THE FRONT. WILL AIM FOR HIGHS
IN THE 60S FOR THE WEEKEND...WITH LATE WEEK/WEEKEND LOWS MAINLY IN
THE 40S ALTHOUGH A FEW UPPER 30S MAY CREEP INTO NORTHERN AREAS.
KB
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH
THE NEXT WEEK. BREEZY NORTH WINDS WILL DEVELOP MONDAY BEHIND A COLD
FRONT BUT RELATIVE HUMIDITIES WILL REMAIN ABOVE 20 PERCENT.
KB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/15
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
639 PM CDT SUN SEP 30 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
259 PM CDT SUN SEP 30 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION POTENTIAL MONDAY
AFTERNOON/EVENING AND TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING NEAR THE U.S. WEST COAST...A SHORTWAVE TROUGH
DROPPING DOWN INTO SOUTH CENTRAL CANADA AND NORTH DAKOTA...UPPER
LOWS OVER THE SOUTHERN PLAINS AND NEW ENGLAND...AND RIDGING OVER THE
FORECAST AREA. OTHER THAN SOME CIRRUS STREAMING NORTHEAST ACROSS
IOWA AHEAD OF THE SOUTHERN PLAINS UPPER LOW...MOSTLY SUNNY SKIES
EXIST ACROSS MUCH OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER
VALLEY REGION. THIS IS DUE TO PLENTIFUL DRY AIR SEEN ON 12Z
SOUNDINGS FROM ABR...MPX AND GRB...WHERE DEWPOINT DEPRESSIONS OF 10C
OR MORE EXISTED THROUGHOUT MUCH OF THE TROPOSPHERE. AT THE
SURFACE...HIGH PRESSURE WAS SITUATED ACROSS THE GREAT LAKES WHILE A
COLD FRONT EXTENDED FROM THE MANITOBA/ONTARIO BORDER SOUTHWEST INTO
CENTRAL SOUTH DAKOTA. SHARP 850MB TEMPERATURE GRADIENT EXISTS
BETWEEN THESE TWO SURFACE FEATURES...NOTED BY 12Z SOUNDING DATA OF
15C AT INL AND MPX COMPARED TO 8C AT GRB. THIS HAS RESULTED IN A
SIMILAR SHARP GRADIENT IN CURRENT TEMPERATURES....FROM THE LOWER 80S
IN WESTERN MINNESOTA TO THE UPPER 60S IN EASTERN WISCONSIN.
TONIGHT AND MONDAY...SHORTWAVE TROUGH COMING INTO NORTH DAKOTA IS
PROGGED TO SPLIT APART INTO TWO BY THE 30.12Z GFS/UKMET/CANADIAN AND
ECMWF...WITH PART OF IT HEADING INTO NORTHWEST ONTARIO AND THE OTHER
DROPPING SOUTH INTO NEBRASKA BY LATE MONDAY. THIS SCENARIO CREATES
SOME ISSUES FOR PRECIPITATION TO OCCUR...SINCE THE UPPER LEVEL
FORCING GETS SPLIT AROUND THE FORECAST AREA. PLUS THE AIRMASS IS
QUITE DRY. ALL FOUR MODELS SUGGEST A DRY FORECAST. THE 30.00Z ECMWF
AND 30.12Z NAM ON THE OTHER HAND KEEP MOST OF THE TROUGH
TOGETHER....DROPPING IT INTO MN AND IA DURING THE AFTERNOON. AS
SUCH...STRONGER FORCING EXISTS AND A FRONTOGENETICAL BAND OF LIGHT
RAIN IS FORECAST TO MOVE INTO NORTHWEST SECTIONS OF THE FORECAST
AREA DURING THE AFTERNOON. HAVE FOLLOWED THE MAJORITY OF THE 30.12Z
GUIDANCE AND PULLED OUT PRECIPITATION CHANCES ENTIRELY. BOTH
SCENARIOS STILL HAVE THE COLD FRONT OVER THE EASTERN DAKOTAS SLIDE
INTO THE FORECAST AREA WITH SIMILAR TIMING...SLOWLY MOVING THROUGH
DURING THE COURSE OF THE DAY MONDAY. AS SUCH...THERE COULD BE SOME
SLIGHT COOLING IN SOUTHEAST MINNESOTA LATE IN THE DAY. OTHERWISE...
850MB TEMPS OF 10-12C AT 18Z MONDAY COMBINED WITH MID/HIGH CLOUD
COVER SHOULD SUPPORT HIGHS TOPPING OUT IN THE UPPER 60S TO LOW 70S.
ENOUGH HIGH CLOUDS AND A SOUTHERLY GRADIENT LOOKS TO BE IN PLACE
TONIGHT TO PRECLUDE ANY VALLEY FOG DEVELOPMENT. THEY SHOULD ALSO
RESULT IN WARMER LOWS...ESPECIALLY WEST OF THE MISSISSIPPI RIVER.
GOING PREVIOUS FORECAST LOWS LOOK REASONABLE...WITH THE TYPICAL
WISCONSIN COLD SPOTS DROPPING INTO THE UPPER 30S DUE TO A LONGER
PERIOD OF DECOUPLED WINDS.
MONDAY NIGHT AND TUESDAY...THE POSSIBLY SPLIT SHORTWAVE TROUGH LOOKS
TO MOVE THROUGH THE FORECAST AREA LATE MONDAY NIGHT...WITH RIDGING
BUILDING IN FROM THE WEST ON TUESDAY AS A POTENT UPPER TROUGH BEGINS
TO DROP SOUTH INTO MONTANA. AGAIN WHETHER OR NOT PRECIPITATION FALLS
MONDAY NIGHT DEPENDS ON HOW SPLIT APART THAT SHORTWAVE TROUGH IS...
WITH THE 30.00Z ECMWF DEPICTING A MUCH BETTER CHANCE OF RAIN
COMPARED TO THE 30.12Z NAM/GFS/UKMET/CANADIAN/ECMWF. CONTINUED TO
FOLLOW THE DRY MAJORITY AS WELL AS PREVIOUS DRY FORECAST.
STILL...AFTER 06Z TUESDAY...DRY WEATHER SHOULD BE THE RULE WITH
SKIES CLEARING OUT...ESPECIALLY OVER THE NORTHWESTERN 2/3 OF THE
AREA. TEMPERATURES SHOULD STILL REMAIN SEASONABLE MONDAY
NIGHT...DESPITE THE COLD FRONTAL PASSAGE...DUE TO A COMBINATION OF
THE CLOUDS AND 850MB TEMPS ONLY FALLING TO 6-8C BY 12Z TUESDAY.
GENERALLY FOLLOWED A BLEND OF GUIDANCE WHICH RESULTS IN LOWS IN THE
40S. WITH SUN BACK OUT FOR TUESDAY AND THE GIVEN 850MB TEMPS...HIGHS
REACHING UP INTO THE UPPER 60S TO LOW 70S SEEM REASONABLE.
TUESDAY NIGHT AND WEDNESDAY...THE POTENT UPPER TROUGHING DROPPING
INTO MONTANA ON TUESDAY IS PROGGED TO CONTINUE DIGGING SOUTHEAST...
INTO WYOMING AND PERHAPS THE DAKOTAS AS WELL BY 00Z THURSDAY. AS
THIS TROUGH DIGS...IT HELPS TO KICK OUT THE STALLED UPPER LOW IN THE
SOUTHERN PLAINS. MODEL TRENDS HAVE SHOWN A LOT OF RETROGRESSION THE
PAST COUPLE OF DAYS WITH THIS UPPER LOW...WHICH IS NOW SLATED TO
LIFT UP THROUGH LOWER MICHIGAN ON WEDNESDAY. A DEFORMATION
PRECIPITATION BAND ASSOCIATED WITH THIS UPPER LOW IS FORECAST BY THE
30.12Z NAM TO PERHAPS CLIP PORTIONS OF GRANT AND ADAMS COUNTIES ON
WEDNESDAY. THE NAM IS A WESTERN OUTLIER...WITH ALL OTHER MODELS
KEEPING THE BAND TRACKING NOT MUCH FARTHER WEST THAN THE CHICAGO
AREA. THEREFORE...HAVE DISCOUNTED THE NAM AT THIS TIME...AND WILL
FOLLOW THE MAJORITY SHOWING UPPER RIDGING HOLDING OVER THE FORECAST
AREA BETWEEN THE POTENT UPPER TROUGH AND UPPER LOW. SUBSIDENCE AND
DRY AIR UNDER THIS UPPER RIDGE IS EXPECTED TO RESULT IN DRY WEATHER
FOR THIS TUESDAY NIGHT AND WEDNESDAY PERIOD. DEPENDING ON CLOUD
COVER AND IF IT RAINS MONDAY NIGHT...COULD BE A CONCERN FOR VALLEY
FOG TUESDAY NIGHT...SINCE A SURFACE RIDGE OF HIGH PRESSURE SHOULD BE
IN PLACE. OTHERWISE...TEMPERATURES LOOK FAIRLY MILD FOR EARLY
OCTOBER WITH LOWS STILL IN THE 40S AND 850MB TEMPS OF 10-12C ON
WEDNESDAY BOOSTING HIGHS INTO THE LOW TO MID 70S.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
259 PM CDT SUN SEP 30 2012
IN THE MEAN...THE 30.12Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ALL
CONTINUE TO FORECAST A BIG CHANGE IN THE UPPER LEVEL PATTERN DURING
THE LONG TERM PERIOD. BY THE WEEKEND...THERE SHOULD BE DEEP UPPER
LEVEL TROUGHING IN PLACE ACROSS THE EASTERN TWO THIRDS OF CANADA AS
WELL AS THE NORTHERN PLAINS EASTWARD INTO THE GREAT LAKES. FALL WILL
REALLY BE FELT THIS WEEKEND AS 850MB TEMPS PLUMMET TO BELOW -2C.
PLENTY OF DIFFERENCES EXIST ON HOW WE GET TO THE WEEKEND...MOSTLY
RELATED TO THAT POTENT TROUGH THE DIGS INTO WYOMING ON WEDNESDAY.
THE 30.12Z ECMWF/CANADIAN/GFS ALL HAVE THE POTENT TROUGH TURNING
NEGATIVE TILT AS IT COMES ACROSS THE NORTHERN PLAINS INTO MINNESOTA
WEDNESDAY NIGHT AND THURSDAY. HOW FAR NORTHWEST THIS TURN TO
NEGATIVE TILT OCCURS AND TIMING IS AT ODDS AMONGST THE MODELS...WITH
THE 30.00Z ECMWF/30.12Z CANADIAN FARTHER TO THE NORTHWEST THAN THE
30.12Z GFS. THIS HAS MAJOR IMPLICATIONS ON HOW MUCH PRECIPITATION
AND COLD AIR TIMING. IN THE CASE OF THE 30.00Z ECMWF/30.12Z
CANADIAN...THEY ARE MUCH LIGHTER ON PRECIPITATION COMPARED TO THE
30.12Z GFS. NEW 30.12Z ECMWF IS COMPLETELY DRY. FOR NOW...WILL
FOLLOW A CONSENSUS APPROACH WITH 20 CHANCES WEDNESDAY NIGHT AND
30-50 ON THURSDAY. ALSO OF NOTE IS THE 30.12Z ECMWF/CANADIAN ARE
MUCH FASTER THAN THE GFS. MUCH COOLER DAY ANTICIPATED ON THURSDAY
TOO AS THE COLD FRONT PASSES...SENDING 850MB TEMPS DOWN TO 0-4C BY
00Z FRIDAY. BREEZY NORTHWEST WINDS LIKELY TOO BEHIND THE FRONT...
ESPECIALLY IF THE GFS PANS OUT. MAINLY DRY WEATHER SHOULD FOLLOW FOR
THURSDAY NIGHT. FOR FRIDAY AND SATURDAY...THE 30.00Z/30.12Z ECMWF
SHOW SOME FRONTOGENESIS-TYPE LIGHT RAIN OCCURRING ACROSS MUCH OF
THE FORECAST AREA...NORTH OF A STALLED BOUNDARY FROM KANSAS TO
INDIANA. THE 30.12Z GFS/CANADIAN HAVE THIS BOUNDARY MUCH FARTHER
SOUTH...RESULTING IN DRY CONDITIONS. GIVEN THE GENERALLY GOOD
PERFORMANCE OF THE ECMWF...NEED TO HAVE AT LEAST SOME 20 PERCENT
CHANCES FOR FRIDAY AND SATURDAY...ESPECIALLY SOUTH OF I-90. ALL
MODELS HAVE HIGH PRESSURE CROSSING THE AREA ON SUNDAY...THUS DRIER
WEATHER IS EXPECTED.
&&
.AVIATION...TONIGHT AND MONDAY
639 PM CDT SUN SEP 30 2012
THE MAIN FOCUS GOING INTO TOMORROW IS WITH A COLD FRONT THAT WILL
COME THROUGH TOMORROW MORNING. CURRENT TIMING BRINGS THIS FRONT
THROUGH RST AROUND 14Z AND LSE AROUND 18Z. WINDS WILL COME AROUND
FROM THE SOUTH TO THE NORTHWEST AND BECOME GUSTY UP TO 20KTS AS
THE FRONT COMES THROUGH TOMORROW. RAIN SHOWERS DO NOT LOOK LIKELY
WITH THIS FRONTAL PASSAGE THOUGH A FEW SPRINKLES MAY BE POSSIBLE
GOING INTO THE AFTERNOON AS A 8KFT CLOUD DECK MOVES IN. CONDITIONS
ARE EXPECTED TO REMAIN VFR THROUGHOUT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
259 PM CDT SUN SEP 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
426 AM EDT MON OCT 1 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 341 AM EDT MON OCT 1 2012
AN UPPER TROUGH SLOWLY LIFTING OUT OF THE MISSISSIPPI VALLEY WILL
KEEP CHANCES FOR RAIN IN THE FORECAST TODAY THROUGH WEDNESDAY.
WEDNESDAY NIGHT THIS FEATURE FINALLY LIFTS OUT OF THE AREA AND
ALLOWS THINGS TO DRY OUT. THURSDAY NIGHT A COLD FRONT WILL MOVE
THROUGH AND BRING CHANCES FOR SHOWERS AND THUNDERSTORMS AND USHER IN
COOLER TEMPERATURES. AFTER THAT UPPER PATTERN IS MORE PROGRESSIVE
AND COULD SEE SHORTWAVES MOVE THROUGH THE FLOW AND HAVE SLIGHT
CHANCES FOR PRECIPITATION DUE TO THIS.
&&
.NEAR TERM /TODAY/...
ISSUED AT 341 AM EDT MON OCT 1 2012
CURRENT PRECIP SHIELD NEAR THE KENTUCKY TENNESSEE BORDER IS MATCHING
UP NICELY WITH ISENTROPIC LIFT AT 300K IN THE NAM. GFS IS A BIT
FURTHER SOUTH WITH THE ISENTROPIC LIFT CURRENTLY...AND THUS IT
BRINGS IN THE PRECIPITATION SLOWER TODAY IF AT ALL. THIS SEEMS TO BE
RESULTING FROM A SLOWER NORTHWARD MOVEMENT OF THE SURFACE LOW IN THE
GFS. OTHER MODELS ARE QUICKER WITH THE NORTHWARD MOVEMENT OF THE LOW
AND NOT AS FAR EAST. WILL FOLLOW THE 300K ISENTROPIC LIFT IN THE NAM
FOR THE INTRODUCTION OF POPS INTO THE AREA...RESULTING IN A SLIGHTLY
SLOWER ARRIVAL THAN PREVIOUS FORECAST BUT HIGHER POPS BY AFTERNOON
SPREADING FURTHER NORTH. THIS ARRIVAL OF PRECIP IN THE SOUTH AROUND
18Z IS SIMILAR TO THAT SEEN IN THE 3Z HRRR AND THE 6Z RAP. GUIDANCE
TEMPERATURES WERE SIMILAR SO USED A MAV/MET AVERAGE. WILL CONTINUE
TO MONITOR TO SEE IF SHOWERS MOVE NORTH QUICKER THAN FORECAST BUT AT
THIS POINT LOOKS UNLIKELY BEFORE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 341 AM EDT MON OCT 1 2012
FORECAST FOCUS IS ON POPS THROUGH THE PERIOD. MODELS HAVE SOME
DISTINCT DISAGREEMENTS DESCRIBED BELOW. GFS TAKES THE SURFACE LOW
FURTHER SOUTH AND EAST THAN NAM/12Z ECMWF/UKMET OR SREFS UNTIL
TUESDAY AFTERNOON AND AS A RESULT IT/S QPF FIELDS BARELY BRING
PRECIPITATION INTO THE SOUTHERN COUNTIES AND PRODUCE NOTHING IN THE
NORTH OR WEST UNTIL TUESDAY NIGHT WHEN THE LOW SWINGS A BIT WEST.
LOOKING AT THE UPPER LEVEL Q VECTOR CONVERGENCE AS WELL AS LOW LEVEL
FRONTOGENESIS FIELDS EVEN IN THE GFS THE QPF DOESN/T SEEM TO MATCH
UP. THE UPPER LEVEL FORCING ARRIVES BY MIDDAY MONDAY ACROSS THE AREA
AND FRONTOGENESIS ARRIVES IN THE SOUTH BY 0Z AND LIFTS NORTH THROUGH
THE AREA FROM 0 TO 12Z TUESDAY. BOTH IMPLY QPF ACROSS MUCH OF THE
AREA. UKMET SOLUTION MATCHES UP FAIRLY WELL WITH NAM AND SREFS ARE
ALSO IN THIS CAMP. THEREFORE PREFER A NAM/SREF SOLUTION THROUGH
TUESDAY NIGHT.
ISENTROPIC LIFT AND GOOD JET DYNAMICS ESPECIALLY ACROSS THE EASTERN
COUNTIES WILL BE IN PLACE TONIGHT AND THIS SHOULD BE SUFFICIENT TO
JUSTIFY CATEGORICAL POPS IN THE EAST TAPERING TO HIGH CHANCE IN THE
NORTHWEST. A SMALL AMOUNT OF ELEVATED INSTABILITY WILL ALSO BE
ADVECTED IN ACROSS THE SOUTH AND EAST AND THUS INCLUDE A SLIGHT
CHANCE FOR THUNDER THERE AS WELL. TUESDAY SHOULD SEE THE ARRIVAL OF
MORE INSTABILITY. AGAIN THE UPPER LEVEL JET WILL BE PARKED OVER THE
AREA AND ISENTROPIC LIFT WILL CONTINUE AND WENT WITH LIKELY POPS
ACROSS ALL BUT THE NORTHWEST WITH A CHANCE FOR THUNDER ACROSS THE
SAME AREA AS THE LIKELY POPS. TUESDAY NIGHT AND WEDNESDAY THE UPPER
TROUGH CONTINUES OVER THE AREA WITH THE TROUGH AXIS MOVING THROUGH
ON WEDNESDAY AFTERNOON. THE SURFACE LOW LIFTS THROUGH THE AREA
DURING THIS TIME AS WELL. FORCING IS A BIT WEAKER DURING THIS TIME
BUT SUFFICIENT TO INCLUDE CHANCES FOR RAIN. AFTER THE TROUGH AXIS
GETS EAST OF THE AREA BY WEDNESDAY EVENING THERE WILL BE NOTHING
LEFT IN THE WAY OF FORCING AND WEDNESDAY NIGHT SHOULD BE DRY AS A
RESULT.
FOR TEMPERATURES LEANED COOLER THAN GUIDANCE FOR HIGHS WITH
SIGNIFICANT CLOUD COVER AND RAIN. FOR LOWS FAVORED WARMER GUIDANCE
FOR SAME REASON.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 341 AM EDT MON OCT 1 2012
MAIN CHALLENGE TO THE EXTENDED WILL BE ATTEMPTING TO RESOLVE MODEL
DIFFERENCES ESPECIALLY RELATED TO QPF.
MODELS ARE IN A BIT BETTER AGREEMENT TO START THE EXTENDED OFF AS
THE ALL KEYING IN ON A POTENT NEGATIVELY TILTED TROUGH THAT WILL BE
PIVOTING FROM THE UPPER MIDWEST INTO ONTARIO ON FRIDAY. FAST UPPER
FLOW AROUND THE BASE OF THE TROUGH WILL PUSH A COLD FRONT QUICKLY
THROUGH CENTRAL INDIANA THURSDAY NIGHT AND TO AROUND A CINCINNATI TO
MEMPHIS LINE BY 12Z FRIDAY. THE STRENGTH OF THIS SYSTEM ALONG WITH
SOME WEAK INSTABILITY PER THE MODELS SHOULD RESULT IN AT LEAST A FEW
SHOWERS AND ISOLATED THUNDERSTORMS SHORTLY AFTER 00Z FRIDAY.
SOUTHWEST FLOW AHEAD OF THE FRONT SHOULD RESULT IN SLIGHTLY ABOVE
NORMAL TEMPERATURES ON THURSDAY.
BY 00Z DAY...THE MODELS START TO HAVE BIG DIFFERENCES. MODELS ARE
ALL SHOWING A VERY LARGE AREA OF WEST CENTRAL CANADIAN HIGH PRESSURE
EXTENDING SOUTHEAST TO THE TENNESSEE VALLEY BEHIND THE DEPARTING
FRONT. HOWEVER...THE 12Z AND 00Z ECMWF RUNS ARE MUCH STRONGER AND
FURTHER NORTHEAST WITH A SOUTHWEST SYSTEM THAN ANY OTHER EXTENDED
MODEL PER COLLABORATION WITH THE HYDROMETEOROLOGICAL PREDICTION
CENTER. THIS RESULTS IN THE EURO MOVING A WAVE ACROSS THE OHIO
VALLEY ON SATURDAY AND RESULTANT OVERRUNNING AND A LARGE AREA OF QPF
ACROSS OUR FORECAST AREA. THE OTHER MODELS ARE WELL SOUTHWEST WITH
THE OVERRUNNING AND QPF. THAT SAID...KEPT SMALL POPS FROM THE
REGIONAL ENSEMBLE THROUGH SATURDAY NIGHT IN THE EVENT THE THE EURO
ENDS UP VERIFYING BETTER AND/OR ANY WAVE IN THE FAST ZONAL FLOW
ALOFT HAPPENS TO SQUEEZE OUT SOME LIGHT QPF. AT ANY RATE...ALL
MODELS AGREE ON THE CANADIAN HIGH PRESSURE CENTERED ACROSS CENTRAL
INDIANA ON SUNDAY WITH A DRY COLUMN. SO SHOULD NOT SEE ANY SHOWERS
THEN.
REGIONAL ENSEMBLES LOOK PRETTY REASONABLE WITH TEMPERATURES STARTING
OUT ABOVE NORMAL IN THE 70S ON THURSDAY AND GETTING PROGRESSIVELY
COLDER WITH AFTERNOON HIGHS WELL BELOW NORMAL AND ONLY IN THE 50S
BY SATURDAY. OVERNIGHT LOWS WILL BE IN THE 30S BY SATURDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR THE 010900Z TAF ISSUANCE/...
ISSUED AT 426 AM EDT MON OCT 1 2012
NO CHANGES NEEDED TO THE TAFS.
PREVIOUS DISCUSSION FOLLOWS...
CEILINGS ABOVE 050 AND UNRESTRICTED VISIBILITY EXPECTED AT THE TAF
SITES THROUGH 011800Z. MODEL DATA SUGGEST AREAS OF LIGHT RAIN MAY
BEGIN AFFECTING THE TAF SITES FROM THE SOUTH AFTER 011800Z.
SURFACE WINDS MAY APPROACH 15 KTS FROM 060-090 DEGREES TOWARDS
MIDDAY ON MONDAY...ESPECIALLY AT KBMG/KHUF/KIND.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....KOCH
AVIATION...JAS/MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
343 AM EDT MON OCT 1 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM
AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 341 AM EDT MON OCT 1 2012
AN UPPER TROUGH SLOWLY LIFTING OUT OF THE MISSISSIPPI VALLEY WILL
KEEP CHANCES FOR RAIN IN THE FORECAST TODAY THROUGH WEDNESDAY.
WEDNESDAY NIGHT THIS FEATURE FINALLY LIFTS OUT OF THE AREA AND
ALLOWS THINGS TO DRY OUT. THURSDAY NIGHT A COLD FRONT WILL MOVE
THROUGH AND BRING CHANCES FOR SHOWERS AND THUNDERSTORMS AND USHER IN
COOLER TEMPERATURES. AFTER THAT UPPER PATTERN IS MORE PROGRESSIVE
AND COULD SEE SHORTWAVES MOVE THROUGH THE FLOW AND HAVE SLIGHT
CHANCES FOR PRECIPITATION DUE TO THIS.
&&
.NEAR TERM /TODAY/...
ISSUED AT 341 AM EDT MON OCT 1 2012
CURRENT PRECIP SHIELD NEAR THE KENTUCKY TENNESSEE BORDER IS MATCHING UP
NICELY WITH ISENTROPIC LIFT AT 300K IN THE NAM. GFS IS A BIT FURTHER
SOUTH WITH THE ISENTROPIC LIFT CURRENTLY...AND THUS IT BRINGS IN THE
PRECIPITATION SLOWER TODAY IF AT ALL. THIS SEEMS TO BE RESULTING
FROM A SLOWER NORTHWARD MOVEMENT OF THE SURFACE LOW IN THE GFS.
OTHER MODELS ARE QUICKER WITH THE NORTHWARD MOVEMENT OF THE LOW AND
NOT AS FAR EAST. WILL FOLLOW THE 300K ISENTROPIC LIFT IN THE NAM FOR
THE INTRODUCTION OF POPS INTO THE AREA...RESULTING IN A SLIGHTLY
SLOWER ARRIVAL THAN PREVIOUS FORECAST BUT HIGHER POPS BY AFTERNOON
SPREADING FURTHER NORTH. THIS ARRIVAL OF PRECIP IN THE SOUTH AROUND
18Z IS SIMILAR TO THAT SEEN IN THE 3Z HRRR AND THE 6Z RAP. GUIDANCE
TEMPERATURES WERE SIMILAR SO USED A MAV/MET AVERAGE. WILL CONTINUE
TO MONITOR TO SEE IF SHOWERS MOVE NORTH QUICKER THAN FORECAST BUT AT
THIS POINT LOOKS UNLIKELY BEFORE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 341 AM EDT MON OCT 1 2012
FORECAST FOCUS IS ON POPS THROUGH THE PERIOD. MODELS HAVE SOME
DISTINCT DISAGREEMENTS DESCRIBED BELOW. GFS TAKES THE SURFACE LOW
FURTHER SOUTH AND EAST THAN NAM/12Z ECMWF/UKMET OR SREFS UNTIL
TUESDAY AFTERNOON AND AS A RESULT IT/S QPF FIELDS BARELY BRING
PRECIPITATION INTO THE SOUTHERN COUNTIES AND PRODUCE NOTHING IN THE
NORTH OR WEST UNTIL TUESDAY NIGHT WHEN THE LOW SWINGS A BIT WEST.
LOOKING AT THE UPPER LEVEL Q VECTOR CONVERGENCE AS WELL AS LOW LEVEL
FRONTOGENESIS FIELDS EVEN IN THE GFS THE QPF DOESN/T SEEM TO MATCH
UP. THE UPPER LEVEL FORCING ARRIVES BY MIDDAY MONDAY ACROSS THE AREA
AND FRONTOGENESIS ARRIVES IN THE SOUTH BY 0Z AND LIFTS NORTH THROUGH
THE AREA FROM 0 TO 12Z TUESDAY. BOTH IMPLY QPF ACROSS MUCH OF THE
AREA. UKMET SOLUTION MATCHES UP FAIRLY WELL WITH NAM AND SREFS ARE
ALSO IN THIS CAMP. THEREFORE PREFER A NAM/SREF SOLUTION THROUGH
TUESDAY NIGHT.
ISENTROPIC LIFT AND GOOD JET DYNAMICS ESPECIALLY ACROSS THE EASTERN
COUNTIES WILL BE IN PLACE TONIGHT AND THIS SHOULD BE SUFFICIENT TO
JUSTIFY CATEGORICAL POPS IN THE EAST TAPERING TO HIGH CHANCE IN THE
NORTHWEST. A SMALL AMOUNT OF ELEVATED INSTABILITY WILL ALSO BE
ADVECTED IN ACROSS THE SOUTH AND EAST AND THUS INCLUDE A SLIGHT
CHANCE FOR THUNDER THERE AS WELL. TUESDAY SHOULD SEE THE ARRIVAL OF
MORE INSTABILITY. AGAIN THE UPPER LEVEL JET WILL BE PARKED OVER THE
AREA AND ISENTROPIC LIFT WILL CONTINUE AND WENT WITH LIKELY POPS
ACROSS ALL BUT THE NORTHWEST WITH A CHANCE FOR THUNDER ACROSS THE
SAME AREA AS THE LIKELY POPS. TUESDAY NIGHT AND WEDNESDAY THE UPPER
TROUGH CONTINUES OVER THE AREA WITH THE TROUGH AXIS MOVING THROUGH
ON WEDNESDAY AFTERNOON. THE SURFACE LOW LIFTS THROUGH THE AREA
DURING THIS TIME AS WELL. FORCING IS A BIT WEAKER DURING THIS TIME
BUT SUFFICIENT TO INCLUDE CHANCES FOR RAIN. AFTER THE TROUGH AXIS
GETS EAST OF THE AREA BY WEDNESDAY EVENING THERE WILL BE NOTHING
LEFT IN THE WAY OF FORCING AND WEDNESDAY NIGHT SHOULD BE DRY AS A
RESULT.
FOR TEMPERATURES LEANED COOLER THAN GUIDANCE FOR HIGHS WITH
SIGNIFICANT CLOUD COVER AND RAIN. FOR LOWS FAVORED WARMER GUIDANCE
FOR SAME REASON.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 341 AM EDT MON OCT 1 2012
MAIN CHALLENGE TO THE EXTENDED WILL BE ATTEMPTING TO RESOLVE MODEL
DIFFERENCES ESPECIALLY RELATED TO QPF.
MODELS ARE IN A BIT BETTER AGREEMENT TO START THE EXTENDED OFF AS
THE ALL KEYING IN ON A POTENT NEGATIVELY TILTED TROUGH THAT WILL BE
PIVOTING FROM THE UPPER MIDWEST INTO ONTARIO ON FRIDAY. FAST UPPER
FLOW AROUND THE BASE OF THE TROUGH WILL PUSH A COLD FRONT QUICKLY
THROUGH CENTRAL INDIANA THURSDAY NIGHT AND TO AROUND A CINCINNATI TO
MEMPHIS LINE BY 12Z FRIDAY. THE STRENGTH OF THIS SYSTEM ALONG WITH
SOME WEAK INSTABILITY PER THE MODELS SHOULD RESULT IN AT LEAST A FEW
SHOWERS AND ISOLATED THUNDERSTORMS SHORTLY AFTER 00Z FRIDAY.
SOUTHWEST FLOW AHEAD OF THE FRONT SHOULD RESULT IN SLIGHTLY ABOVE
NORMAL TEMPERATURES ON THURSDAY.
BY 00Z DAY...THE MODELS START TO HAVE BIG DIFFERENCES. MODELS ARE
ALL SHOWING A VERY LARGE AREA OF WEST CENTRAL CANADIAN HIGH PRESSURE
EXTENDING SOUTHEAST TO THE TENNESSEE VALLEY BEHIND THE DEPARTING
FRONT. HOWEVER...THE 12Z AND 00Z ECMWF RUNS ARE MUCH STRONGER AND
FURTHER NORTHEAST WITH A SOUTHWEST SYSTEM THAN ANY OTHER EXTENDED
MODEL PER COLLABORATION WITH THE HYDROMETEOROLOGICAL PREDICTION
CENTER. THIS RESULTS IN THE EURO MOVING A WAVE ACROSS THE OHIO
VALLEY ON SATURDAY AND RESULTANT OVERRUNNING AND A LARGE AREA OF QPF
ACROSS OUR FORECAST AREA. THE OTHER MODELS ARE WELL SOUTHWEST WITH
THE OVERRUNNING AND QPF. THAT SAID...KEPT SMALL POPS FROM THE
REGIONAL ENSEMBLE THROUGH SATURDAY NIGHT IN THE EVENT THE THE EURO
ENDS UP VERIFYING BETTER AND/OR ANY WAVE IN THE FAST ZONAL FLOW
ALOFT HAPPENS TO SQUEEZE OUT SOME LIGHT QPF. AT ANY RATE...ALL
MODELS AGREE ON THE CANADIAN HIGH PRESSURE CENTERED ACROSS CENTRAL
INDIANA ON SUNDAY WITH A DRY COLUMN. SO SHOULD NOT SEE ANY SHOWERS
THEN.
REGIONAL ENSEMBLES LOOK PRETTY REASONABLE WITH TEMPERATURES STARTING
OUT ABOVE NORMAL IN THE 70S ON THURSDAY AND GETTING PROGRESSIVELY
COLDER WITH AFTERNOON HIGHS WELL BELOW NORMAL AND ONLY IN THE 50S
BY SATURDAY. OVERNIGHT LOWS WILL BE IN THE 30S BY SATURDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR THE 010600Z TAFS/...
ISSUED AT 1240 AM EDT MON OCT 1 2012
CEILINGS ABOVE 050 AND UNRESTRICTED VISIBILITY EXPECTED AT THE TAF
SITES THROUGH 011800Z. MODEL DATA SUGGEST AREAS OF LIGHT RAIN MAY
BEGIN AFFECTING THE TAF SITES FROM THE SOUTH AFTER 011800Z.
SURFACE WINDS MAY APPROACH 15 KTS FROM 060-090 DEGREES TOWARDS
MIDDAY ON MONDAY...ESPECIALLY AT KBMG/KHUF/KIND.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....KOCH
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
338 AM MDT MON OCT 1 2012
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 216 AM MDT MON OCT 1 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW LONGWAVE TROUGH
EXTENDING SOUTH ACROSS THE EASTERN CONUS...WITH TWO CLOSED LOW
CENTERS OVER NEW ENGLAND AND ANOTHER OVER THE SOUTHERN MISSISSIPPI
VALLEY. A LARGE SCALE RIDGE EXTENDS NORTH ACROSS THE WESTERN
CONUS...WITH NORTH TO NORTHWEST FLOW OVER THE PLAINS. AT THE
SURFACE A COLD FRONT HAS DROPPED SOUTH ACROSS THE NORTHEAST PART
OF THE CWA.
ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ALONG THIS FRONT
NEAR AN AXIS OF H85 FRONTOGENESIS IN THE NORTHWEST. THIS ACTIVITY
SHOULD CONTINUE TO SPREAD SOUTHEAST ACROSS THE REST OF THE FORECAST
AREA THROUGH THE EARLY MORNING HOURS. THE FRONT SHOULD BE SOUTH OF
THE CWA BY THE AFTERNOON...WITH SUBSIDENCE BUILDING IN FROM THE
WEST. I LEFT LINGERING POPS IN PLACE ACROSS THE EAST THROUGH THE IN
PROXIMITY TO FRONT WHERE GUIDANCE CONTINUES TO INDICATE LIGHT QPF.
PRECIP AMOUNTS SHOULD BE LOW WITH A FEW HUNDREDTHS OF AN INCH AT THE
MOST.
OVERALL TREND SHOULD BE CLEARING BY THIS EVENING WITH SUBSIDENCE
OVERSPREADING THE AREA FROM THE WEST. HIGH TEMPERATURES TODAY WILL
BE ABOUT 10 TO 15F COOLER THAN SUNDAY WITH HIGHS IN THE 60S/70S
ACROSS THE CWA. THE AIRMASS TONIGHT LOOKS VERY SIMILAR TO OUR LAST
FEW COOL-DOWNS...SO I USED THAT AS A BASIS FOR MY LOW TEMPERATURE
FORECAST. WITH CLEAR SKIES AND CALM WINDS EXPECTED TEMPERATURES
SHOULD DROP INTO THE LOW 40S ACROSS MUCH OF THE AREA...WITH
TRADITIONAL COLD SPOTS IN THE MID TO UPPER 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 336 AM MDT MON OCT 1 2012
SHORTWAVE RIDGING BUILDS OVER THE TRI-STATE AREA TUESDAY AND
WEDNESDAY...WITH DRY CONDITIONS EXPECTED. A WARM FRONT WILL MOVE
ACROSS THE REGION TUESDAY WITH TEMPERATURE WARMING BACK INTO THE
UPPER 70S/LOW 80S. A COLD FRONT WILL DROP SOUTH INTO THE REGION LATE
WEDNESDAY OR WEDNESDAY NIGHT. OVERALL TREND HAS BEEN TO SPEED UP
THIS FRONTAL PASSAGE. WITH THE AMOUNT OF SPREAD BETWEEN MODELS ON
THIS FEATURE...CONFIDENCE IS LOW ON TEMPERATURE FORECAST WED. LARGE
SCALE ASCENT BUILDS OVER THE REGION WEDNESDAY NIGHT BEHIND THIS
FRONT AS ITS PARENT TROUGH MOVES ACROSS NORTHERN PLAINS. BEST
MOISTURE ADVECTION/LIFT SHOULD BE ACROSS THE NORTH...SO I KEPT
CHANCE POPS MAINLY NORTH OF I-70.
A DEFINITE CHANGE TO THE WEATHER BY LATE IN THE WEEK AS MUCH COLDER
TEMPERATURES ARE USHERED IN BEHIND A STRONG COLD FRONT THAT WILL MOVE
ACROSS THE PLAINS WEDNESDAY AFTERNOON. A SURFACE HIGH WILL BEGIN TO
BUILD INTO THE CENTRAL PLAINS ON THURSDAY BEHIND THE COLD FRONT AS
THE UPPER LEVEL LOW MOVES INTO THE GREAT LAKES REGION. FORECAST GETS
A LITTLE COMPLICATED LATE FRIDAY AND INTO THE WEEKEND. BROAD TROUGH
WITH CLOSED LOW OVER THE GREAT LAKES WILL SWING ANOTHER SHORTWAVE
TROUGH THROUGH THE NORTHERN PLAINS. MODELS ARE IN AGREEMENT WITH
THIS SHORTWAVE TROUGH...BUT DISAGREE ON THE MAGNITUDE AND SPEED OF
THE SYSTEM. ANOTHER CLOSED LOW WILL BE DEEPENING OFF THE COAST OF
CALIFORNIA AND WILL SLOWLY BEGIN TO MOVE ONSHORE BY EARLY NEXT WEEK.
THIS WILL KEEP THE REGION UNDER NEAR ZONAL TO NORTHWEST FLOW ALOFT.
NEAR THE SURFACE...A REINFORCING SHOT OF COLDER AIR WILL SLIDE DOWN
FROM CANADA AND INTO THE CENTRAL PLAINS BY THE WEEKEND. THIS NEXT
SHOT OF COLD AIR WILL ONLY ALLOW HIGHS TO CLIMB INTO THE 40S AND
MAYBE LOW 50S ON SATURDAY. THIS WILL ALSO BE OUR BEST CHANCE TO HAVE
OUR FIRST HARD FREEZE THIS SEASON AS MODELS AGREE THAT TEMPERATURES
WILL DROP INTO THE LOW TO MID 30S BOTH SAT AND SUN MORNINGS.
AS FOR PRECIPITATION CHANCES...MODELS ARE IN AGREEMENT THAT A COLD
WET WEEKEND IS A HIGH PROBABILITY. BEST POSSIBILITY LOOKS TO BE
FRIDAY NIGHT THROUGH SATURDAY AS THE SHORTWAVE TROUGH BEGINS TO MOVE
ACROSS THE NORTHERN PLAINS AND THE NEXT COLD SURGE SLIDES SOUTHWARD.
THE COLDER MODEL SOLUTIONS HAVE HINTED THAT A CHANCE FOR A RAIN/SNOW
MIX MAY BE POSSIBLE IN SOME PARTS OF THE TRI STATE REGION. GIVEN
THAT THIS IS PRETTY LATE IN THE EXTENDED PERIOD...WILL WAIT AND SEE
IF THIS TREND CONTINUES. FOR NOW...HAVE JUST KEPT RAIN SHOWERS IN
THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1122 PM MDT SUN SEP 30 2012
ONE BATCH OF PRECIPITATION HAS ENDED WITH THE NEXT BATCH
DEVELOPING TO OUR NORTHWEST AS A SHORTWAVE TROUGH AND RATHER
STRONG LEFT FRONT QUADRANT OF THE JET MOVES TOWARDS THE AREA.
SATELLITE AND RADAR TRENDS INDICATE EXPANDING RETURNS AND CLOUDS.
NOT ENTIRELY SURE HOW MUCH WILL MAKE IT HERE AND THE AFFECT ON THE
TAF SITES. IT DOES LOOK LIKE CONDITIONS WILL REMAIN VFR. AFTER
PRECIPITATION THERE WILL BE CLEARING. ALSO A FRONT WILL MOVE
THROUGH...AND WILL SEE GUSTY NORTHERLY WINDS THROUGH MOST OF THE
DAY BEFORE BECOMING MUCH LIGHTER.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...PMM
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
217 AM MDT MON OCT 1 2012
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 216 AM MDT MON OCT 1 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW LONGWAVE TROUGH
EXTENDING SOUTH ACROSS THE EASTERN CONUS...WITH TWO CLOSED LOW
CENTERS OVER NEW ENGLAND AND ANOTHER OVER THE SOUTHERN MISSISSIPPI
VALLEY. A LARGE SCALE RIDGE EXTENDS NORTH ACROSS THE WESTERN
CONUS...WITH NORTH TO NORTHWEST FLOW OVER THE PLAINS. AT THE
SURFACE A COLD FRONT HAS DROPPED SOUTH ACROSS THE NORTHEAST PART
OF THE CWA.
ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ALONG THIS FRONT
NEAR AN AXIS OF H85 FRONTOGENESIS IN THE NORTHWEST. THIS ACTIVITY
SHOULD CONTINUE TO SPREAD SOUTHEAST ACROSS THE REST OF THE FORECAST
AREA THROUGH THE EARLY MORNING HOURS. THE FRONT SHOULD BE SOUTH OF
THE CWA BY THE AFTERNOON...WITH SUBSIDENCE BUILDING IN FROM THE
WEST. I LEFT LINGERING POPS IN PLACE ACROSS THE EAST THROUGH THE IN
PROXIMITY TO FRONT WHERE GUIDANCE CONTINUES TO INDICATE LIGHT QPF.
PRECIP AMOUNTS SHOULD BE LOW WITH A FEW HUNDREDTHS OF AN INCH AT THE
MOST.
OVERALL TREND SHOULD BE CLEARING BY THIS EVENING WITH SUBSIDENCE
OVERSPREADING THE AREA FROM THE WEST. HIGH TEMPERATURES TODAY WILL
BE ABOUT 10 TO 15F COOLER THAN SUNDAY WITH HIGHS IN THE 60S/70S
ACROSS THE CWA. THE AIRMASS TONIGHT LOOKS VERY SIMILAR TO OUR LAST
FEW COOL-DOWNS...SO I USED THAT AS A BASIS FOR MY LOW TEMPERATURE
FORECAST. WITH CLEAR SKIES AND CALM WINDS EXPECTED TEMPERATURES
SHOULD DROP INTO THE LOW 40S ACROSS MUCH OF THE AREA...WITH
TRADITIONAL COLD SPOTS IN THE MID TO UPPER 30S.
SHORTWAVE RIDGING BUILDS OVER THE TRI-STATE AREA TUESDAY AND
WEDNESDAY...WITH DRY CONDITIONS EXPECTED. A WARM FRONT WILL MOVE
ACROSS THE REGION TUESDAY WITH TEMPERATURE WARMING BACK INTO THE
UPPER 70S/LOW 80S. A COLD FRONT WILL DROP SOUTH INTO THE REGION LATE
WEDNESDAY OR WEDNESDAY NIGHT. OVERALL TREND HAS BEEN TO SPEED UP
THIS FRONTAL PASSAGE. WITH THE AMOUNT OF SPREAD BETWEEN MODELS ON
THIS FEATURE...CONFIDENCE IS LOW ON TEMPERATURE FORECAST WED. LARGE
SCALE ASCENT BUILDS OVER THE REGION WEDNESDAY NIGHT BEHIND THIS
FRONT AS ITS PARENT TROUGH MOVES ACROSS NORTHERN PLAINS. BEST
MOISTURE ADVECTION/LIFT SHOULD BE ACROSS THE NORTH...SO I KEPT
CHANCE POPS MAINLY NORTH OF I-70.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 239 PM MDT SUN SEP 30 2012
MONDAY NIGHT THROUGH TUESDAY WILL BE DRY AS AN UPPER LEVEL SHORT
WAVE RIDGE AND SURFACE RIDGE MOVE THROUGH THE AREA. MONDAY NIGHT
LOW TEMPERATURES APPROACH THE MID 30S FROM MCCOOK SOUTHEAST TO HILL
CITY...WHICH MAY CAUSE LOW LYING AREAS TO SEE PATH CY FROST. WILL
KEEP A MENTION OF FROST OUT OF THE FORECAST FOR NOW SINCE MOST
MODELS HAVE LOWS JUST ABOVE FROST CRITERIA. HOWEVER WITH DEW
POINTS NEAR 30 DEGREES AT SUNRISE...CLEAR SKIES AND LIGHT
WINDS...LOWS MAY BE A FEW DEGREES TOO WARM. ON A SIDE NOTE THE
AVERAGE FIRST FREEZE FOR THE TRI-STATE AREA USUALLY OCCURS IN THE
NEXT 10 DAYS.
TUESDAY NIGHT THE SHORT WAVE RIDGE MOVES SOUTH AS AN UPPER LEVEL
LONG WAVE TROUGH DROPS OUT OF CANADA INTO THE NORTHWEST US WITH A
STRONG COLD FRONT AHEAD OF IT. MODELS DIFFER ON THE SPEED OF THE
COLD FRONT...WITH THE NAM/SREF AND SOME OF THE 12Z GEFS MEMBERS
MOVING THE FRONT HALFWAY THROUGH THE AREA BY SUNRISE WEDNESDAY. THE
12Z GFS HAS SPED THE FRONTAL PASSAGE UP SOME. GIVEN THE CURRENT
FASTER TREND...AND THE FACT THE NAM HAD THE A BETTER HANDLE ON THE
SURFACE TROUGH FOR SUNDAY...AM LEANING TOWARDS THE FASTER FRONTAL
PASSAGE FOR LATE TUESDAY/EARLY WEDNESDAY. A FASTER FRONTAL PASSAGE
WILL PLACE THE FRONT AHEAD OF THE BETTER 1000-500MB MOISTURE...SO AM
NOT EXPECTING MUCH IF ANY PRECIP. WITH THE FRONT AT THIS POINT.
WEDNESDAY THROUGH SUNDAY GENERAL MODEL TREND HAS BEEN TO SPEED UP
THE FRONTAL TIMING FOR WEDNESDAY AS MENTION PREVIOUSLY...RESULTING
IN A DRY FRONTAL PASSAGE. MODELS INCREASE THE 1000-500MB RELATIVE
HUMIDITY BEHIND THE FRONT AND AHEAD OF THE MAIN SHORT WAVE
TROUGH...HOWEVER MODELS STILL DIFFER AS TO HOW FAR SOUTH THE TROUGH
WILL DIG AND HOW FAST THE TROUGH WILL EXIT THE AREA WEDNESDAY
NIGHT. MODELS CONSENSUS IS LEANING TOWARDS KEEPING THE MAJORITY OF
THE TROUGH FURTHER NORTH...BUT THERE IS STILL A CHANCE THE ENTIRE
AREA MAY RECEIVE RAINFALL SO HAVE AT LEAST SLIGHT PRECIP. CHANCES
FOR THE ENTIRE AREA WED. NIGHT. THROUGH THE REST OF THE WEEK THE
UPPER LEVEL TROUGH BROADENS OVER THE NORTHERN CONUS AS IT MOVES
EAST. TOWARD THE END OF THE WEEK ANOTHER SHORT WAVE TROUGH/COLD
FRONT DIVES SOUTH THROUGH THE FLOW...MOVING OVER THE AREA FRIDAY
NIGHT...GIVING THE AREA A SHOT AT PRECIP. THROUGH SUNDAY.
BEHIND THE COLD FRONT TEMPERATURES WILL BE 5 TO 15 DEGREES BELOW
NORMAL. THURSDAY NIGHT THROUGH SATURDAY NIGHT LOW LYING AREAS WILL
BE AT RISK FOR FROST AS TEMPERATURES DIP TO THE MID 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1122 PM MDT SUN SEP 30 2012
ONE BATCH OF PRECIPITATION HAS ENDED WITH THE NEXT BATCH
DEVELOPING TO OUR NORTHWEST AS A SHORTWAVE TROUGH AND RATHER
STRONG LEFT FRONT QUADRANT OF THE JET MOVES TOWARDS THE AREA.
SATELLITE AND RADAR TRENDS INDICATE EXPANDING RETURNS AND CLOUDS.
NOT ENTIRELY SURE HOW MUCH WILL MAKE IT HERE AND THE AFFECT ON THE
TAF SITES. IT DOES LOOK LIKE CONDITIONS WILL REMAIN VFR. AFTER
PRECIPITATION THERE WILL BE CLEARING. ALSO A FRONT WILL MOVE
THROUGH...AND WILL SEE GUSTY NORTHERLY WINDS THROUGH MOST OF THE
DAY BEFORE BECOMING MUCH LIGHTER.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
123 AM CDT MON OCT 1 2012
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 121 AM CDT MON OCT 1 2012
WV IMAGERY AND 00Z UPPER AIR ANALYSIS INDICATE A CLOSED OFF UPPER
LEVEL LOW DRIFTING EASTWARD ACROSS THE ARK-LA-TEX REGION. MEANWHILE,
A +90KT UPPER LEVEL JET IS DIVING SOUTH-SOUTHEAST ACROSS MONTANA
INTO EASTERN WYOMING. NEAR THE SURFACE, A POOL OF LOW LEVEL MOISTURE
EXTENDS NORTHWARD ACROSS WEST TEXAS INTO SOUTHWEST KANSAS WITH H85
DEWPOINTS UP AROUND 8C. A SURFACE TROUGH IS EDGING SLOWLY EASTWARD
ACROSS WESTERN KANSAS AS A COLD FRONT APPROACHES FROM THE NORTH
THROUGH NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 143 PM CDT SUN SEP 30 2012
LATEST RAP WAS CONSISTENT WITH THE 12Z NAM AND THEY BOTH VERIFIED
FAIRLY WELL WITH THE LOCATION OF THE SURFACE LEE TROUGH WHICH WAS
LOCATED ACROSS FAR WESTERN KANSAS. AHEAD OF THIS SURFACE BOUNDARY
A 0-1KM THETA-E RIDGE AXIS EXTENDED NORTHWARD INTO SOUTHWEST
NEBRASKA. THIS FEATURE IS FORECAST TO MOVE VERY LITTLE THROUGH
EARLY TONIGHT AND WILL BE THE AREA WHERE THE BETTER LOW LEVEL
FORCING WILL BE LATE TODAY AS 500MB TEMPERATURE COOL AND
INSTABILITY IMPROVES. WILL THEREFORE RETAIN MENTION OF LATE
DAY/EARLY NIGHT THUNDERSTORMS ACROSS MAINLY SOUTHWEST AND NORTH
CENTRAL KANSAS.
THE UPPER LEVEL JET LOCATED OVER MONTANA EARLIER TODAY WILL DIVE
SOUTH ALONG THE WESTERN HIGH PLAINS AND BY EARLY MONDAY THE LEFT
EXIT REGION OF THIS JET IS FORECAST TO BE LOCATED OVER WESTERN
KANSAS. BUFR SOUNDINGS ALSO SUGGESTING MOISTURE WILL BE PRESENT
AROUND THE 700MB LEVEL EARLY IN THE DAY AS A COLD FRONT MOVES
SOUTH ACROSS SOUTHWEST KANSAS. BASED ON THE LOCATION OF THE UPPER
JET, BETTER 700MB MOISTURE ALONG WITH SOME FRONTOGENESIS WILL
RETAIN MENTION OF PRECIPITATION EARLY IN THE DAY. BUFR SOUNDING WIND
PROFILES INDICATED 30KTS AT 800MB LEVEL BEHIND THIS FRONT WITH
MEAN MIXED LEVEL WINDS SUGGESTING WINDS SPEEDS IN THE 20 TO 30 MPH
RANGE WILL BE POSSIBLE. 850MB TEMPERATURES AT 00Z TUESDAY SUGGESTS
HIGHS WILL BE IN THE LOW TO MID 70S WHICH WERE SIMILAR TO THE
MOSGUIDE, AND CONSMOS. THIS ALSO ONLY A FEW DEGREES COOLER THAN
THE PREVIOUS FORECAST SO GIVEN A SLIGHT SUPER NEAR THE SURFACE THE
PREVIOUS FORECAST WITH HIGHS MAINLY IN THE 75 TO NEAR 80 DEGREE
RANGE STILL APPEARS ON TRACK.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 401 PM CDT SUN SEP 30 2012
NORTHERLY UPPER-LEVEL FLOW WILL PERSIST TUESDAY ON THE BACK SIDE OF AN
UPPER LOW. IN THE ABSENCE OF LEE TROUGHING, PLEASANT WEATHER CAN
BE EXPECTED. IT WILL BE FAIRLY COOL IN THE LOWER 40S IN THE
MORNING GIVEN THE DRY AIR AND LIGHT WINDS. THE AFTERNOON WILL TURN
OUT PLEASANT WITH HIGHS IN THE LOWER TO MID 70S AND LIGHT WINDS. A
STRONG SHORTWAVE TROUGH WILL PROGRESS SOUTHEASTWARD OUT OF CANADA
INTO THE NORTHERN PLAINS BY WEDNESDAY. AHEAD OF THE ASSOCIATED
COLD FRONT, TEMPERATURES SHOULD REACH INTO THE UPPER 70S IN PLACES
LIKE SCOTT CITY AND DIGHTON, WITH WARMER 80S FROM DODGE CITY INTO
SOUTH CENTRAL KANSAS. SOME MID-LEVEL MOISTURE WILL ACCOMPANY THIS
SYSTEM AFTER THE LOW-LEVEL BAROCLINIC ZONE MOVES THROUGH AND THE
JET STREAK APPROACHES. SO A FEW RAIN SHOWERS CANNOT BE RULED OUT
WEDNESDAY NIGHT, ESPECIALLY FROM DODGE CITY NORTHWARD TO THE
INTERSTATE 70 CORRIDOR.
THERE ARE MAJOR DISAGREEMENTS AMONG THE VARIOUS MODELS BY
THURSDAY AND THROUGH THE WEEKEND. THE ECMWF DEVELOPS A POSITIVELY
TILTED UPPER-LEVEL TROUGH FROM WINNIPEG SOUTHWESTWARD TO THE
CALIFORNIA COAST, WHILE THE GFS DEVELOPS A LARGE TROUGH OVER THE
GREAT LAKES REGION, WITH A CUTOFF LOW OFF OF THE WEST COAST.
INTERESTINGLY, EVEN THOUGH THE PATTERNS ARE DIFFERENT IN THE
GFS/ECMWF, THEY BOTH SHOW MID-LEVEL FRONTOGENESIS AND SOME
POSSIBLE LIGHT RAIN FOR FRIDAY NIGHT. OTHER THAN THAT, BOTH MODELS
SHOW SURFACE HIGH PRESSURE ENTRENCHED ACROSS THE PLAINS WITH
FAIRLY COOL HIGHS MAINLY IN THE LOWER TO MID 60S FOR THURSDAY AND
FRIDAY AND LOWS DROPPING INTO THE 40S. BY SATURDAY AND SUNDAY,
THE GFS KEEPS A NORTHWESTERLY UPPER-LEVEL FLOW REGIME OVER THE
PLAINS AS UPPER TROUGHING PERSISTS OVER THE GREAT LAKES. THIS
WOULD BE A COOL AND MAINLY DRY REGIME. THE ECMWF INDICATES
ISENTROPIC LIFT AS LOW LEVEL COOL AIR BECOMES WEDGED UNDERNEATH
THE WEST- SOUTHWESTERLY MID-LEVEL FLOW. THIS WOULD YIELD A CLOUDY
PATTERN WITH PERHAPS SOME AREAS OF LIGHT RAIN SATURDAY AND SUNDAY,
AND POSSIBLY EVEN SNOW BY SUNDAY NIGHT. THE UKMET IS SIMILAR TO
THE ECMWF AT DAY 6 WHILE THE GEM AGREES MORE WITH THE GFS. DUE TO
THE GREAT UNCERTAINTY, WE JUST OPTED TO GO WITH THE ALLBLEND
INITIALIZATION, WHICH FEATURES COOL BUT DRY WEATHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1200 AM CDT MON OCT 1 2012
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DRIFT SOUTH ACROSS
SOUTHWEST KANSAS OVERNIGHT POTENTIALLY AFFECTING KDDC AND KGCK.
OTHERWISE, VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH
LATE THIS AFTERNOON. AS FOR WINDS, A COLD FRONT PUSHING SOUTH
OUT OF WESTERN SOUTH DAKOTA INTO WESTERN NEBRASKA EARLY THIS
MORNING, WILL CONTINUE MOVING SOUTH INTO AND ACROSS WESTERN
KANSAS BY LATE THIS MORNING. AS A RESULT, LIGHT AND VARIABLE
WINDS OVERNIGHT WILL BECOME NORTHERLY 20 TO 30KT BY MID DAY
MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 75 43 74 50 / 20 0 0 0
GCK 73 42 75 49 / 20 0 0 0
EHA 73 45 76 50 / 20 0 0 0
LBL 75 45 75 49 / 20 0 0 0
HYS 73 40 74 50 / 20 0 0 0
P28 78 47 74 52 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJOHNSON
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1131 PM MDT SUN SEP 30 2012
.UPDATE...
ISSUED AT 1122 PM MDT SUN SEP 30 2012
COMPLETED AN UPDATE EARLIER. INITIALLY WAS TO REFINE POPS/WX AND
OTHER HOURLY GRIDS FOR THE REST OF THE EVENING. MAIN CHANGE TO ADD
SLIGHT CHANCE POPS FOR THE 06Z TO 18Z TIME FRAME. RATHER STRONG
LEFT FRONT QUADRANT OF THE JET WILL BE AFFECTING DURING THIS TIME
ALONG WITH STRONG MID LEVEL MESOSCALE FORCING. THETA-E LAPSE RATES
INDICATE THERE SHOULD BE A DECENT RESPONSE TO THE LIFT. FOR THE
LAST HOUR OR TWO CLOUDS AND RADAR RETURNS HAVE BEEN INCREASING TO
THE NORTHWEST WITH SOME LIGHT PRECIPITATION MAKING IT TO THE GROUND.
SOUNDINGS WOULD INDICATE THAT AIR MASS INITIALLY SATURATED AT 700
MB. BUT WITH THE LIFT...LAPSE RATES...AND SAME ELEVATED CAPE/LITTLE
CINH...SHOULD BE ABLE TO HAVE SOME VERY LIGHT QPF. ADJUSTED WINDS
PER LATEST RUC THROUGH THE REST OF TONIGHT INTO EARLY TOMORROW.
INCREASED THE SPEEDS BEHIND THE FRONT. OTHERWISE JUST DID NORMAL
ADJUSTMENTS TO THE HOURLY GRIDS.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 1259 PM MDT SUN SEP 30 2012
NORTHWEST FLOW WILL BRING A SHORTWAVE ACROSS THE REGION TONIGHT.
HOWEVER H8-7 LAYER MEAN RH IS LIMITED AND DYNAMICS ARE WEAK. THERE
IS ENOUGH CAPE FOR THUNDERSTORMS SO WILL GO WITH A SLIGHT CHANCE
OF THUNDERSTORMS FOR THE FA THIS EVENING WITH SOME CHANCE POPS IN
THE EAST NEAR THE SURFACE TROUGH. DYNAMICS WILL WEAKEN AS THE
SHORTWAVE EXITS BY 06Z MONDAY. POPS WILL BE LOWERED TO NIL AT THIS
POINT AND CONTINUE THROUGH MONDAY AS SUBSIDENCE BUILDS INTO
NORTHWEST KANSAS. MIN TEMPERATURES TONIGHT WILL FALL INTO THE
UPPER 40S IN EASTERN COLORADO WITH AROUND 50S ELSEWHERE. MAX
TEMPERATURES MONDAY WILL RANGE FROM 70 TO 75.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 239 PM MDT SUN SEP 30 2012
MONDAY NIGHT THROUGH TUESDAY WILL BE DRY AS AN UPPER LEVEL SHORT
WAVE RIDGE AND SURFACE RIDGE MOVE THROUGH THE AREA. MONDAY NIGHT
LOW TEMPERATURES APPROACH THE MID 30S FROM MCCOOK SOUTHEAST TO HILL
CITY...WHICH MAY CAUSE LOW LYING AREAS TO SEE PATH CY FROST. WILL
KEEP A MENTION OF FROST OUT OF THE FORECAST FOR NOW SINCE MOST
MODELS HAVE LOWS JUST ABOVE FROST CRITERIA. HOWEVER WITH DEW POINTS NEAR
30 DEGREES AT SUNRISE...CLEAR SKIES AND LIGHT WINDS...LOWS MAY BE A
FEW DEGREES TOO WARM. ON A SIDE NOTE THE AVERAGE FIRST FREEZE FOR
THE TRI-STATE AREA USUALLY OCCURS IN THE NEXT 10 DAYS.
TUESDAY NIGHT THE SHORT WAVE RIDGE MOVES SOUTH AS AN UPPER LEVEL
LONG WAVE TROUGH DROPS OUT OF CANADA INTO THE NORTHWEST US WITH A
STRONG COLD FRONT AHEAD OF IT. MODELS DIFFER ON THE SPEED OF THE
COLD FRONT...WITH THE NAM/SREF AND SOME OF THE 12Z GEFS MEMBERS
MOVING THE FRONT HALFWAY THROUGH THE AREA BY SUNRISE WEDNESDAY. THE
12Z GFS HAS SPED THE FRONTAL PASSAGE UP SOME. GIVEN THE CURRENT
FASTER TREND...AND THE FACT THE NAM HAD THE A BETTER HANDLE ON THE
SURFACE TROUGH FOR SUNDAY...AM LEANING TOWARDS THE FASTER FRONTAL
PASSAGE FOR LATE TUESDAY/EARLY WEDNESDAY. A FASTER FRONTAL PASSAGE
WILL PLACE THE FRONT AHEAD OF THE BETTER 1000-500MB MOISTURE...SO AM
NOT EXPECTING MUCH IF ANY PRECIP. WITH THE FRONT AT THIS POINT.
WEDNESDAY THROUGH SUNDAY GENERAL MODEL TREND HAS BEEN TO SPEED UP
THE FRONTAL TIMING FOR WEDNESDAY AS MENTION PREVIOUSLY...RESULTING
IN A DRY FRONTAL PASSAGE. MODELS INCREASE THE 1000-500MB RELATIVE
HUMIDITY BEHIND THE FRONT AND AHEAD OF THE MAIN SHORT WAVE
TROUGH...HOWEVER MODELS STILL DIFFER AS TO HOW FAR SOUTH THE TROUGH
WILL DIG AND HOW FAST THE TROUGH WILL EXIT THE AREA WEDNESDAY
NIGHT. MODELS CONSENSUS IS LEANING TOWARDS KEEPING THE MAJORITY OF
THE TROUGH FURTHER NORTH...BUT THERE IS STILL A CHANCE THE ENTIRE
AREA MAY RECEIVE RAINFALL SO HAVE AT LEAST SLIGHT PRECIP. CHANCES FOR THE
ENTIRE AREA WED. NIGHT. THROUGH THE REST OF THE WEEK THE UPPER
LEVEL TROUGH BROADENS OVER THE NORTHERN CONUS AS IT MOVES EAST.
TOWARD THE END OF THE WEEK ANOTHER SHORT WAVE TROUGH/COLD FRONT DIVES SOUTH
THROUGH THE FLOW...MOVING OVER THE AREA FRIDAY NIGHT...GIVING THE
AREA A SHOT AT PRECIP. THROUGH SUNDAY.
BEHIND THE COLD FRONT TEMPERATURES WILL BE 5 TO 15 DEGREES BELOW
NORMAL. THURSDAY NIGHT THROUGH SATURDAY NIGHT LOW LYING AREAS WILL
BE AT RISK FOR FROST AS TEMPERATURES DIP TO THE MID 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1122 PM MDT SUN SEP 30 2012
ONE BATCH OF PRECIPITATION HAS ENDED WITH THE NEXT BATCH
DEVELOPING TO OUR NORTHWEST AS A SHORTWAVE TROUGH AND RATHER
STRONG LEFT FRONT QUADRANT OF THE JET MOVES TOWARDS THE AREA.
SATELLITE AND RADAR TRENDS INDICATE EXPANDING RETURNS AND CLOUDS.
NOT ENTIRELY SURE HOW MUCH WILL MAKE IT HERE AND THE AFFECT ON THE
TAF SITES. IT DOES LOOK LIKE CONDITIONS WILL REMAIN VFR. AFTER
PRECIPITATION THERE WILL BE CLEARING. ALSO A FRONT WILL MOVE
THROUGH...AND WILL SEE GUSTY NORTHERLY WINDS THROUGH MOST OF THE
DAY BEFORE BECOMING MUCH LIGHTER.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...FS
LONG TERM...JTL
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1208 AM CDT MON OCT 1 2012
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 1212 PM CDT SUN SEP 30 2012
AT 12Z SUNDAY AN UPPER LEVEL JET STREAK EXTENDED FROM NORTHWEST
MONTANA INTO SOUTHERN BRITISH COLUMBIA. AT THE 500MB LEVEL A -14
TO -15C THERMAL TROUGH EXTENDED FROM NORTH DAKOTA INTO SOUTHWEST
NEBRASKA. ANOTHER COLDER UPPER LEVEL THERMAL TROUGH WAS LOCATED
NEAR THE LEFT EXIT REGION THE UPPER LEVEL JET LOCATED NEAR
SOUTHERN SASKATCHEWAN AND SOUTHERN ALBERTA CANADA. AT THE 700MB
LEVEL A +5 TO +7C THERMAL RIDGE EXTENDED FROM SOUTHERN SOUTH DAKOTA
INTO NORTHEAST COLORADO WITH SOME 700-600MB MOISTURE AND MID LEVEL
INSTABILITY PRESENT IN THIS AREA BASED ON THE NORTH PLATTE
SOUNDING AND RAP. MOSAIC RADAR LOOP ALSO PICKED UP ON A FEW
ISOLATED SHOWERS AND THUNDERSTORMS IN THIS AREA. NEAR THE SURFACE
A TROUGH OF LOW PRESSURE STRETCHED FROM CENTRAL NEBRASKA INTO WEST
CENTRAL KANSAS WITH A WEDGE OF HIGHER MOISTURE PRESENT AHEAD OF
THIS TROUGH BASED THE EARLY MORNING STATUS/FOG, LOW TO MID 50S
SURFACE DEWPOINTS, AND +10 TO +12C 850MB DEWPOINTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 143 PM CDT SUN SEP 30 2012
LATEST RAP WAS CONSISTENT WITH THE 12Z NAM AND THEY BOTH VERIFIED
FAIRLY WELL WITH THE LOCATION OF THE SURFACE LEE TROUGH WHICH WAS
LOCATED ACROSS FAR WESTERN KANSAS. AHEAD OF THIS SURFACE BOUNDARY
A 0-1KM THETA-E RIDGE AXIS EXTENDED NORTHWARD INTO SOUTHWEST
NEBRASKA. THIS FEATURE IS FORECAST TO MOVE VERY LITTLE THROUGH
EARLY TONIGHT AND WILL BE THE AREA WHERE THE BETTER LOW LEVEL
FORCING WILL BE LATE TODAY AS 500MB TEMPERATURE COOL AND
INSTABILITY IMPROVES. WILL THEREFORE RETAIN MENTION OF LATE
DAY/EARLY NIGHT THUNDERSTORMS ACROSS MAINLY SOUTHWEST AND NORTH
CENTRAL KANSAS.
THE UPPER LEVEL JET LOCATED OVER MONTANA EARLIER TODAY WILL DIVE
SOUTH ALONG THE WESTERN HIGH PLAINS AND BY EARLY MONDAY THE LEFT
EXIT REGION OF THIS JET IS FORECAST TO BE LOCATED OVER WESTERN
KANSAS. BUFR SOUNDINGS ALSO SUGGESTING MOISTURE WILL BE PRESENT
AROUND THE 700MB LEVEL EARLY IN THE DAY AS A COLD FRONT MOVES
SOUTH ACROSS SOUTHWEST KANSAS. BASED ON THE LOCATION OF THE UPPER
JET, BETTER 700MB MOISTURE ALONG WITH SOME FRONTOGENESIS WILL
RETAIN MENTION OF PRECIPITATION EARLY IN THE DAY. BUFR SOUNDING WIND
PROFILES INDICATED 30KTS AT 800MB LEVEL BEHIND THIS FRONT WITH
MEAN MIXED LEVEL WINDS SUGGESTING WINDS SPEEDS IN THE 20 TO 30 MPH
RANGE WILL BE POSSIBLE. 850MB TEMPERATURES AT 00Z TUESDAY SUGGESTS
HIGHS WILL BE IN THE LOW TO MID 70S WHICH WERE SIMILAR TO THE
MOSGUIDE, AND CONSMOS. THIS ALSO ONLY A FEW DEGREES COOLER THAN
THE PREVIOUS FORECAST SO GIVEN A SLIGHT SUPER NEAR THE SURFACE THE
PREVIOUS FORECAST WITH HIGHS MAINLY IN THE 75 TO NEAR 80 DEGREE
RANGE STILL APPEARS ON TRACK.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 401 PM CDT SUN SEP 30 2012
NORTHERLY UPPER-LEVEL FLOW WILL PERSIST TUESDAY ON THE BACK SIDE OF AN
UPPER LOW. IN THE ABSENCE OF LEE TROUGHING, PLEASANT WEATHER CAN
BE EXPECTED. IT WILL BE FAIRLY COOL IN THE LOWER 40S IN THE
MORNING GIVEN THE DRY AIR AND LIGHT WINDS. THE AFTERNOON WILL TURN
OUT PLEASANT WITH HIGHS IN THE LOWER TO MID 70S AND LIGHT WINDS. A
STRONG SHORTWAVE TROUGH WILL PROGRESS SOUTHEASTWARD OUT OF CANADA
INTO THE NORTHERN PLAINS BY WEDNESDAY. AHEAD OF THE ASSOCIATED
COLD FRONT, TEMPERATURES SHOULD REACH INTO THE UPPER 70S IN PLACES
LIKE SCOTT CITY AND DIGHTON, WITH WARMER 80S FROM DODGE CITY INTO
SOUTH CENTRAL KANSAS. SOME MID-LEVEL MOISTURE WILL ACCOMPANY THIS
SYSTEM AFTER THE LOW-LEVEL BAROCLINIC ZONE MOVES THROUGH AND THE
JET STREAK APPROACHES. SO A FEW RAIN SHOWERS CANNOT BE RULED OUT
WEDNESDAY NIGHT, ESPECIALLY FROM DODGE CITY NORTHWARD TO THE
INTERSTATE 70 CORRIDOR.
THERE ARE MAJOR DISAGREEMENTS AMONG THE VARIOUS MODELS BY
THURSDAY AND THROUGH THE WEEKEND. THE ECMWF DEVELOPS A POSITIVELY
TILTED UPPER-LEVEL TROUGH FROM WINNIPEG SOUTHWESTWARD TO THE
CALIFORNIA COAST, WHILE THE GFS DEVELOPS A LARGE TROUGH OVER THE
GREAT LAKES REGION, WITH A CUTOFF LOW OFF OF THE WEST COAST.
INTERESTINGLY, EVEN THOUGH THE PATTERNS ARE DIFFERENT IN THE
GFS/ECMWF, THEY BOTH SHOW MID-LEVEL FRONTOGENESIS AND SOME
POSSIBLE LIGHT RAIN FOR FRIDAY NIGHT. OTHER THAN THAT, BOTH MODELS
SHOW SURFACE HIGH PRESSURE ENTRENCHED ACROSS THE PLAINS WITH
FAIRLY COOL HIGHS MAINLY IN THE LOWER TO MID 60S FOR THURSDAY AND
FRIDAY AND LOWS DROPPING INTO THE 40S. BY SATURDAY AND SUNDAY,
THE GFS KEEPS A NORTHWESTERLY UPPER-LEVEL FLOW REGIME OVER THE
PLAINS AS UPPER TROUGHING PERSISTS OVER THE GREAT LAKES. THIS
WOULD BE A COOL AND MAINLY DRY REGIME. THE ECMWF INDICATES
ISENTROPIC LIFT AS LOW LEVEL COOL AIR BECOMES WEDGED UNDERNEATH
THE WEST- SOUTHWESTERLY MID-LEVEL FLOW. THIS WOULD YIELD A CLOUDY
PATTERN WITH PERHAPS SOME AREAS OF LIGHT RAIN SATURDAY AND SUNDAY,
AND POSSIBLY EVEN SNOW BY SUNDAY NIGHT. THE UKMET IS SIMILAR TO
THE ECMWF AT DAY 6 WHILE THE GEM AGREES MORE WITH THE GFS. DUE TO
THE GREAT UNCERTAINTY, WE JUST OPTED TO GO WITH THE ALLBLEND
INITIALIZATION, WHICH FEATURES COOL BUT DRY WEATHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1200 AM CDT MON OCT 1 2012
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DRIFT SOUTH ACROSS
SOUTHWEST KANSAS OVERNIGHT POTENTIALLY AFFECTING KDDC AND KGCK.
OTHERWISE, VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH
LATE THIS AFTERNOON. AS FOR WINDS, A COLD FRONT PUSHING SOUTH
OUT OF WESTERN SOUTH DAKOTA INTO WESTERN NEBRASKA EARLY THIS
MORNING, WILL CONTINUE MOVING SOUTH INTO AND ACROSS WESTERN
KANSAS BY LATE THIS MORNING. AS A RESULT, LIGHT AND VARIABLE
WINDS OVERNIGHT WILL BECOME NORTHERLY 20 TO 30KT BY MID DAY
MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 40 74 50 82 / 0 0 0 0
GCK 41 75 49 81 / 0 0 0 0
EHA 42 76 50 82 / 0 0 0 0
LBL 42 75 49 82 / 0 0 0 0
HYS 41 74 50 81 / 0 0 0 0
P28 46 74 52 85 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...BURGERT
LONG TERM...FINCH
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS JACKSON KY
236 AM EDT MON OCT 1 2012
.UPDATE...
ISSUED AT 236 AM EDT MON OCT 1 2012
SURGE OF MOISTURE HAS MOVED INTO THE COUNTIES BORDERING TN/VA. THE
LATEST HRRR SEEMS TO HAVE A DECENT HANDLE OF THIS PRECIPITATION
SHIELD...ALTHOUGH IT DOES APPEAR TO BE A TAD TOO FAST. HAVE MADE SOME
ADJUSTMENTS TO THE FORCAST...MAINLY FOR A SLIGHTLY SPEEDIER TIMING TO
THE MEASURABLE RAIN. TEMPERATURES ARE ALSO RUNNING WARMER...WITH DEW
POINTS IN THE 50S CWA-WIDE NOW AND EXTENSIVE CLOUD COVER. AS
SUCH...THINK LOW TO MID 50S WILL BE THE BOTTOM END...EVEN IN THE
NORTH.
UPDATE ISSUED AT 1050 PM EDT SUN SEP 30 2012
MADE A FEW MORE TWEAKS TO THE FORECAST FOR THE REMAINDER OF THE
OVERNIGHT PERIOD. RADAR DATA AND SURFACE OBSERVATIONS FROM THE PAST
FEW HOURS HAVE SHOWN THAT SOME LIGHT RAIN HAS BEEN REACHING THE
GROUND IN CENTRAL AND NORTH CENTRAL TENNESSEE. THIS ACTIVITY HAS NOT
BEEN HANDLED VERY WELL BY THE MODELS THUS FAR...SO THE FORECAST HAS
BEEN UPDATED TO REFLECT THE LATEST OBSERVED TRENDS. THE TWO TIERS OF
COUNTIES ALONG AND NORTH OF THE TENNESSEE BORDER COULD BEGIN SEEING
ACCUMULATING RAINFALL BY 6Z TONIGHT. THE RAIN SHOWERS ARE EXPECTED TO
CONTINUE SPREADING SLOWLY NORTHWARD DURING THE NIGHT...AND WILL BE
WELL NORTH OF THE TENNESSEE BORDER BY 12Z ON MONDAY. THE SKY COVER
GRIDS HAVE ALSO BEEN UPDATED TO REFLECT MOSTLY CLOUDY TO CLOUDY SKIES
ACROSS ALL OF EASTERN KENTUCKY. THE QPF...POP12...AND WEATHER TYPE
GRIDS WERE ALSO UPDATED TO REFLECT THE CHANGES MADE TO THE HOURLY
PRECIPITATION PROBABILITY FORECAST GRIDS. THE REST OF THE FORECAST
WAS ON TRACK WITH NO OTHER CHANGES MADE.
UPDATE ISSUED AT 743 PM EDT SUN SEP 30 2012
MADE A FEW MINOR UPDATES TO THE FORECAST GRIDS FOR THE OVERNIGHT
PERIOD. BOTH VISUAL OBSERVATION AND SATELLITE IMAGERY SHOW QUITE
CLEARLY THAT SKIES ACROSS EASTERN AND CENTRAL KENTUCKY HAVE BECOME
BROKEN TO OVERCAST WITH ALTOSTRATUS AND CIRROSTRATUS CLOUDS. THESE
CLOUDS WILL CONTINUE TO STREAM INTO THE AREA FROM THE SOUTH THIS AND
TONIGHT. INCREASED CLOUD COVER ACROSS THE BOARD THROUGH 15Z TOMORROW
TO ACCOUNT FOR THE OBSERVED TRENDS. WILL ALSO BE REMOVING SOME STALE
WORDING FROM THE ZONE TEXT PRODUCT. WILL MONITOR THE CURRENT
CONDITIONS AND LATEST MODEL DATA TO DETERMINE IF FURTHER UPDATES TO
THE FORECAST WILL BE NEEDED THIS EVENING.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 250 PM EDT SUN SEP 30 2012
SHORTWAVE RIDGING CONTINUES TO DOMINATE EASTERN KENTUCKY THIS
AFTERNOON WITH A CUT OFF LOW OVER NEW ENGLAND...AND ANOTHER CUT OFF
LOW OVER THE SOUTHERN PLAINS. THE SYSTEM OVER THE SOUTHERN PLAINS
WILL BE OUR MAIN CONCERN OVER THE NEXT 24 TO 48 HOURS AS THIS CUT OFF
SYSTEM DRIFTS NORTHWARD INTO THE OHIO RIVER VALLEY. AS FOR
TONIGHT...HIGH CLOUDS WILL REMAIN ON THE INCREASE AND GROW THICKER
THROUGH THE NIGHT. COULD BE A BIT OF A GRADIENT WITH TEMPERATURES
TONIGHT...AS AREAS IN THE NORTH AND NORTHEAST MAY DECOUPLE QUICKLY
THIS EVENING WITH TEMPERATURES QUICKLY FALLING THROUGH THE 50S.
MEANWHILE...THE MORE ROBUST CLOUD COVER IN THE SOUTH MAY KEEP
CONDITIONS A BIT MILDER. THUS...GOING TO SHOW A BIT OF A GRADIENT
FROM SOUTHWEST TO NORTHEAST. THE LOWEST READINGS WILL REMAIN IN THE
UPPER 40S IN THE SHELTERED VALLEYS WITH MID 50S IN THE SOUTHWEST.
ISENTROPIC ASCENT WILL KICK INTO FULL GEAR AROUND DAYBREAK TOMORROW
MORNING NEAR THE TENNESSEE BORDER AND SPREAD NORTHWARD THROUGH THE
DAY. A BAND OF MODERATE TO HEAVY RAIN WILL DEVELOP AND PUSH NORTHWARD
THROUGH THE DAY. MODELS IN GOOD AGREEMENT ON A WET DAY...SO HAVE
BUMPED UP POPS ACCORDINGLY. BY MID TO LATE AFTERNOON...DOWNSLOPING
SOUTHEAST WINDS WILL LIKELY BRING A BIT OF A LULL TO EASTERN
KENTUCKY. IN FACT...ALTHOUGH POPS HAVE BEEN LOWERED...WE COULD END UP
DRY FOR A CONSIDERABLE AMOUNT OF TIME LATE TOMORROW AND TOMORROW
EVENING. A WEAK EMBEDDED WAVE IN THE SOUTHERLY FLOW MAY REGENERATE
SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM LATE MONDAY NIGHT...SO
BROUGHT SOME HIGH POPS BACK INTO THE AREA OVERNIGHT. AS FAR AS
TEMPERATURES GO...WENT A BIT HIGHER IN THE DOWNSLOPING AREAS IN THE
SOUTHEAST SINCE WE SHOULD BE ABLE TO WARM UP AFTER THE DEPARTURE OF
THE EARLY DAY RAIN. LOWS MONDAY NIGHT WILL REMAIN MILD WITH DAMP
CONDITIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 332 PM EDT SUN SEP 30 2012
THE MODELS ARE IN GOOD AGREEMENT AT THE START OF THE PERIOD ON
TUESDAY MORNING WITH AN UPPER LOW OVER MISSOURI AND TROUGHING
EXTENDING INTO THE WESTERN GULF. THIS LOW IS ASSOCIATED WITH THE
SOUTHERN STREAM AND ON THE NORTHERN STREAM...THE IS AN UPPER TROUGH
OVER THE PACIFIC NORTHWEST. BY TUESDAY MORNING...THE ASSOCIATED
FRONTAL SYSTEM WILL BE SOUTH AND EAST OF THE AREA WITH EASTERN
KENTUCKY INITIALLY BEING EFFECTED BY OVER RUNNING FROM THE FRONT AND
THEN BEING DOMINATED BY THE UPPER LOW. TUESDAY WILL START OUT WITH
SOME WIDESPREAD LIGHT RAIN AND DRIZZLE AND THEN MORPH MORE INTO
OCCASIONAL INSTABILITY SHOWERS THROUGH WEDNESDAY. BY
THURSDAY...SURFACE HIGH PRESSURE WILL HAVE BUILT INTO THE AREA. THIS
IS WHERE THE MODELS REALLY START TO DIVERGE. THE GFS IS TRYING TO
DEVELOP A SHARP TROUGH OVER THE CENTRAL CONUS...WHILE THE ECMWF HAS
MORE OF A BROAD TROUGH ACROSS MOST OF THE CONUS. THE FORECAST HAS A
FRONT MOVING ACROSS THE AREA ON FRIDAY AND FRIDAY NIGHT WHICH IS MORE
LIKE THE GFS. THE ECMWF DOES NOT HAVE A FRONT MOVING THROUGH UNTIL
SUNDAY. WILL KEEP THE PRECIPITATION IN THERE FOR NOW FOR
FRIDAY...HOWEVER WOULD NOT BE TOO SURPRISED TO SEE IT EVENTUALLY FALL
OUT OF THE FORECAST. AFTER THURSDAY NIGHT...CONFIDENCE DROPS OFF
SHARPLY. THE TEMPERATURES ARE A BIT MORE MODERATE AT THE END OF THE
PERIOD. PREVIOUS MODEL RUNS WERE MUCH COLDER. HAVE ADJUSTED THE
TEMPERATURES TO MATCH THE CURRENT WARMER TREND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 236 AM EDT MON OCT 1 2012
LIGHT RAIN WILL OVERTAKE THE AREA FROM SOUTH TO NORTH THROUGH THE DAY.
VFR CONDITIONS WILL HOLD ON THROUGH 12Z...WITH MVFR CONDITIONS TAKING
HOLD BETWEEN 12 AND 16Z...AND THEN IFR CONDITIONS AFTER 00Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...KAS
LONG TERM....JJ
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
519 AM EDT MON OCT 1 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EDT MON OCT 1 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE WRN GREAT LAKES TO JAMES BAY BETWEEN A LOW OVER NRN NEW ENGLAND
AND A TROUGH FROM MANITOBA INTO NORTH DAKOTA. AT THE SFC...A COLD
FRONT EXTENDED FROM NEAR PICKLE LAKE ONTARIO INTO ERN MN. RADAR
SHOWED SOME WEAK REFLECTIVITIES N CNTRL MN ALIGNED WITH WEAK TO
MODERATE MID LEVEL EVEN THOUGH SFC OBS INDICATED LITTLE MORE THAN
SOME MID CLOUDS. OTHERWISE...HIGH CLOUDS SPREADING ACROSS UPPER MI
AND WEAK SW WINDS HAVE KEPT TEMPS FROM FALLING OFF AS MUCH WITH
READINGS IN THE UPPER 30S AND LOWER 40S INLAND AND NEAR 50 ALONG
LAKE SUPERIOR.
AS THE MANITOBA MID LEVEL TROUGH PROGRESSES TO THE EAST TODAY AND
TONIGHT...THE COLD FRONT WILL ALSO SPREAD ACROSS UPPER MI. SINCE
THERE IS LITTLE MOISTURE INFLOW INTO THE RELATIVELY DRY AIR MASS AND
THE STRONGER 850-500 MB QVECTOR CONV REMAINS NORTH OF LAKE
SUPERIOR...RAIN CHANCES WILL BE MINIMAL. HOWEVER...WITH THE BAND OF
850-600 MB FGEN MOVING INTO THE WEST THIS EVENING...SOME ISOLATED
LIGHT SHOWERS OR SPRINKLES MAY BE POSSIBLE. POTENTIAL FOR ANY LAKE
ENHANCED PCPN WITH NRLY FLOW BEHIND THE FRONT ALSO WILL BE MINIMAL
WITH 850 MB TEMPS ONLY DROPPING TO AROUND 5C (LAKE SFC TEMPS WERE IN
THE 11C TO 14C RANGE).
EVEN WITH INCREASING MID/HIGH CLOUDS...WAA WILL HELP PUSH TEMPS INTO
THE MID AND UPPER 60S. CLOUDS WITH LINGERING 925-850 MB MOISTURE
OVER THE AREA WILL HOLD MIN READINGS IN THE 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 518 AM EDT MON OCT 1 2012
MAIN CONCERN PAST 12Z TUE IS WITH A DEEP UPPER TROUGH MOVING INTO
THE AREA THU...AND STAYING THROUGH THE WEEKEND.
FIRST FOR WED INTO EARLY WED NIGHT...AN UPPER TROUGH OVER THE LOWER
MISSISSIPPI VALLEY WILL SHEAR OFF AND MOVE SE OF THE CWA...WHICH MAY
PRODUCE SOME RAIN OVER THE FAR ERN CWA. PREVIOUS FORECAST WITH
CHANCE POPS OVER THE FAR E LOOKS GOOD SO WILL LEAVE THAT MOSTLY
UNCHANGED.
THEN FOR THE MAIN EVENT THU THROUGH SUN. MAIN IDEA FROM THE MODELS
IS THAT AS THE UPPER TROUGH MOVES INTO THE REGION...THE SRN END OF
THE TROUGH WILL BECOME NEGATIVELY TILTED RESULTING IN THE TROUGH
DEEPENING AND CLOSING OFF SOMEWHERE OVER OR NEAR THE CWA.
COMPLICATING MATTERS...ENERGY FROM THE TROUGH WILL SPLIT BETWEEN THE
SRN END AND THE MORE NRN END (OVER FAR NRN ONTARIO)...AND IT IS
DIFFICULT TO DETERMINE HOW MUCH OF THE ENERGY WILL GO TO THE SRN VS.
NRN END. THIS SEEMS TO BE ONE REASON WHY MODELS HAVE POOR RUN TO RUN
CONTINUITY AND POOR AGREEMENT WITH HOW TO HANDLE THIS SYSTEM. LATEST
RUN OF THE GFS (00Z/01) IS MORE LIKE THE LAST COUPLE RUNS OF THE
ECMWF...BRINGING A MODERATELY DEEPENING SFC LOW FROM WRN LAKE
SUPERIOR AROUND 12Z THU TO JAMES BAY BY 18Z FRI. THERE ARE STILL
SIGNIFICANT DIFFERENCES BETWEEN THE GFS AND ECMWF...BUT THE LATEST
RUN AGREES MORE WITH THE ECMWF THAN THE LAST RUN WITH SHOWING THE
LOW RAPIDLY DEEPENING AS IT MOVED THROUGH THE CENTER OF THE CWA. THE
GEM HAS THE SAME GENERAL IDEA BUT FARTHER N OVER ONTARIO. THE IDEA
OF A DEEPENING SYSTEM MOVING UP THE WRN SIDE OF LAKE SUPERIOR SEEMS
LIKE A REASONABLE AND FAMILIAR SCENARIO...BUT THE TRACK OF THIS
SYSTEM WILL BE VERY TRICKY TO FORECAST. EVEN IF MODEL AGREEMENT WAS
GREAT WITH THIS SYSTEM...THE FACT THAT THE TRACK OF THIS TYPE OF
SYSTEM IS HARD TO FORECAST THIS FAR OUT COMBINED WITH THE FACT THAT
THE SYSTEM HAS NOT MOVED INTO THE N AMERICAN PROFILING NETWORK YET
WOULD STILL LEAVE LITTLE CONFIDENCE IN THE FORECAST FOR THU/FRI. FOR
THIS REASON...AT THIS TIME IT IS NEARLY FUTILE TO MAKE LARGE
ADJUSTMENTS TO THE FORECAST FOR THU/FRI BASED ONLY ON THE LAST RUN
OF THE MODELS...ESPECIALLY GIVEN THE RUN TO RUN DISCONTINUITY FROM
THE MODELS AND THE FACT THAT THE TRACK OF THIS SYSTEM WILL HAVE HUGE
BEARING ON THE FORECAST.
THERE ARE SOME THINGS WE CAN LOOK AT THAT ARE MORE CERTAIN WITH THIS
SYSTEM...LIKE THE COLD AIR AND NW LOW LEVEL WINDS BEHIND THE SYSTEM.
850MB TEMPS FALL BELOW 0C BY LATE THU...AND GET PROGRESSIVELY COLDER
THROUGH FRI NIGHT (ALTHOUGH THE GFS WITH 850MB TEMPS OF -7C TO -9C
AT 12Z SAT IS 3-4C COLDER THAN THE ECMWF). THIS WILL LEAD TO LAKE
ENHANCE/EFFECT RAIN/SNOW IN NW WIND SNOWBELTS BEHIND THE SYSTEM INTO
SUN...WITH DECREASING LOW LEVEL MOISTURE LATE SAT INTO SUN MAKING
FOR MORE SCATTERED COVERAGE. THERE IS POTENTIAL FOR THE FIRST
ACCUMULATING SNOWFALL...ESPECIALLY OVER THE HIGHER TERRAIN OF WRN
UPPER MI WHERE LOW LEVEL TEMPS WILL BE COOLER. ANOTHER MORE CERTAIN
ASPECT WITH THE SYSTEM IS WLY GALES BEHIND THE LOW...ESPECIALLY IF
THE SFC LOW STICKS TO THE LAKE LONGER THAN MODELS SHOW AS IS COMMON
THIS TIME OF YEAR. WITH THE LOW DEEPENING AS IT MOVES OVER OR NEARBY
AND GOOD PRESSURE GRADIENT AND COLD AIR BEHIND THE SYSTEM...GALES
SHOULD BE ON THE STRONG SIDE AND WIND ADVISORIES/WARNINGS MAY BE
NEEDED ON LAND AS WELL...PARTICULARLY OVER THE KEWEENAW PENINSULA
AND ERN UPPER MI NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 125 AM EDT MON OCT 1 2012
EVEN THOUGH SOME HI CLDS WL ARRIVE OVERNGT...EXPECT VFR CONDITIONS
INTO AT LEAST MID AFTN WITH DRY HI PRES DOMINATING. A COLD FNT WL
CROSS UPR MI TODAY...BUT THE AIRMASS IS TOO DRY TO SUPPORT MUCH IN
THE WAY OF SHRA OR EVEN LO CLDS. THE BEST CHC OF SHRA WL BE AFTER
THE COLD FROPA...WHEN SOME LOWER CLDS MIGHT ARRIVE AT IWD/CMX TOWARD
LATE AFTN WITH AN UPSLOPE NW FLOW AND THEN AT SAW LATER IN THE EVNG.
ALTHOUGH SOME GUIDANCE INDICATES MVFR CONDITIONS MIGHT IMPACT THESE
SITES...UPSTREAM OBS IN THE PLAINS SHOW VERY DRY AIR FOLLOWING THE
FROPA...WHICH WOULD LIMIT THE POTENTIAL FOR -SHRA/MVFR CIGS. THE
INCOMING AIRMASS IS ALSO NOT COLD ENUF TO SUPPORT LAKE EFFECT CLDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT MON OCT 1 2012
A COLD FRONT WILL MOVE THROUGH LAKE SUPERIOR TODAY INTO TONIGHT. A
PERIOD OF MODERATE NRLY WINDS TO 25 KNOTS OVER CNTRL AND ERN LAKE
SUPERIOR IS EXPECTED JUST BEHIND THE FRONT LATE THIS EVENING AND
OVERNIGHT. OTHERWISE...WINDS WILL STAY BELOW 20 KNOTS INTO THURSDAY
BEFORE THE PRESSURE GRADIENT TIGHTENS AS A STRONG LOW PRESSURE
SYSTEM LIFTS INTO NORTHERN ONTARIO AND BRINGS WEST GALES THURSDAY
NIGHT INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1238 AM CDT MON OCT 1 2012
.AVIATION...06Z TAF ISSUANCE
A COLD FRONT WILL MOVE INTO THE NORTHLAND EARLY THIS MORNING. THE
RESULT WILL BE A CHANGE IN WINDS FROM A LIGHT SOUTHERLY DIRECTION
TO THE NORTHWEST. AN AREA OF LOW CLOUDS/BR/FG MAY IMPACT KDLH
BEFORE THE FRONT ARRIVES. WINDS WILL ALSO INCREASE BEHIND THE
FRONT. THE FRONT IS GENERALLY EXPECTED TO BE A DRY FRONT...WITH
MAINLY MID AND HIGH CLOUDS...BUT A FEW SPRINKLES OR AN ISOLATED
SHOWER WILL BE POSSIBLE.
&&
.PREV DISCUSSION... /ISSUED 818 PM CDT SUN SEP 30 2012/
AVIATION.../00Z TAF ISSUANCE/
VFR CONDITIONS ARE EXPECTED DURING THE TAF PERIOD. A COLD FRONT
WILL MOVE THROUGH THE REGION ON MONDAY...SWITCHING WINDS FROM A
SOUTHERLY DIRECTION TO THE NORTHWEST. A FEW SPRINKLES OR SHOWERS
ARE POSSIBLE BUT THE FRONT SHOULD GENERALLY MOVE THROUGH DRY.
PREV DISCUSSION... /ISSUED 316 PM CDT SUN SEP 30 2012/
SHORT TERM...SFC HIGH HAD DRIFTED OVER NORTHERN LAKE SUPERIOR AS
OF 20Z WITH DRY AIR ENTRENCHED OVER THE FA. SFC WIND WAS TURNING
FROM THE SE TO THE S AHEAD OF AN APPROACHING A COLD FRONT. THIS
FRONT IS EXPECTED TO MOVE THROUGH NORTHEAST MINNESOTA BY MIDNIGHT
AND NW WI BY 12Z MONDAY. EXPECT THIS TO BE A DRY FROPA WHICH IS
SUPPORTED BY FORECAST SOUNDINGS FROM ALL MODELS WHICH ARE DRY
BELOW 10K FT. HAVE ADDED A MENTION OF PATCHY FOG TO THE NEAR
SHORE WATERS FROM TWO HARBORS TO THE TWIN PORTS AND PORT WING WI
AS WELL AS INLAND TO SUW WHICH THE LATEST HI RES MODELS HRRR AND
NARRE AGREE ON THIS DEVELOPMENT.
BEHIND THE FRONT LATER TONIGHT AND MONDAY A NW WIND IS EXPECTED
AND IT WILL HELP USHER IN COOLER AIR. HOWEVER...WITH PLENTY OF SUN
EXPECTED...LOOK FOR MAX TEMPS IN THE 60S TO NEAR 70 NEAR PBH AND
BRD.
THE SFC RIDGE AXIS OVERLAYS THE FA MONDAY NIGHT AND EXPECT
RADIATIONAL COOLING WITH A CLEARING SKY TO PRODUCE MIN TEMPS IN
THE 30S...TO AROUND 45 NEAR PBH. THE WARMER TEMPS NEAR PBH ARE DUE
TO LINGERING CLOUDS.
LONG TERM...[TUESDAY - SATURDAY]...
SNOW IS APPEARING MORE AND MORE LIKELY FOR LATER THIS WEEK. THE
EXPECTED TREND IS FOR WARMER THAN NORMAL WEATHER ON TUESDAY AND
WEDNESDAY TO COME TO AN END BY THURSDAY WHEN A LOW PRESSURE SYSTEM
MOVES ACROSS SOUTHERN MINNESOTA AND NORTHERN WISCONSIN WEDNESDAY
NIGHT AND THURSDAY. THE SYSTEM...WHICH THE GFS AND ECMWF ARE IN
PRETTY GOOD AGREEMENT WITH...WILL USHER IN RAIN AND MUCH COLDER
WEATHER FOR THURSDAY. THE PCPN COULD TRANSITION TO SNOW OR A
RAIN/SNOW MIXTURE THURSDAY NIGHT. PERIODS OF RAIN AND SNOW COULD
CONTINUE INTO THE WEEKEND AS THE COLD WEATHER STICKS AROUND IN THE
WAKE OF THE SYSTEM. IT IS UNCLEAR AT THIS POINT WHETHER THE SNOW
WILL HAPPEN...BUT IT IS LOOKING MORE AND MORE LIKELY...ESPECIALLY
FOR THURSDAY NIGHT AND FRIDAY NIGHT. DO NOT WANT TO MAKE ANY GUESSES
ABOUT ACCUMULATION AT THIS POINT SINCE THE SYSTEM IS STILL FAR OUT.
AT THIS POINT...DID NOT FORECAST ANY PERIODS OF PURE SNOW...BUT SOME
PERIODS OF A RAIN/SNOW MIXTURE.
AVIATION.../18Z TAF ISSUANCE/
VFR CONDITIONS WILL LIKELY CONTINUE ACROSS NE MINNESOTA AND NW
WISCONSIN THROUGH MONDAY MORNING. THE LIGHT SOUTHERLY WINDS WILL
SWITCH TO NORTHWESTERLY TONIGHT WITH THE PASSAGE OF A COLD
FRONT...AND THE WINDS WILL INCREASE LATE TOMORROW MORNING. THERE
MAY BE FOG SOUTH OF KDLH...BUT AT THIS TIME...DO NOT THINK IT WILL
AFFECT THE TERMINAL. THERE MAY BE ISOLATED LIGHT RAIN SHOWERS
TOMORROW MORNING NEAR KDLH AND KHIB.
&&
.POINT TEMPS/POPS...
DLH 65 39 63 45 / 10 0 0 0
INL 64 33 66 43 / 10 0 0 0
BRD 68 35 70 45 / 10 0 0 0
HYR 66 39 68 45 / 10 10 0 0
ASX 67 39 64 46 / 10 10 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...CANNON
AREA FORECAST DISCUSSION
NWS HASTINGS NE
453 AM CDT MON OCT 1 2012
.SHORT TERM...TODAY THROUGH 12Z THURSDAY. MAIN FORECAST CHALLENGE
DURING THIS PERIOD WILL BE HIGH TEMPERATURES AHEAD OF THE COLD
FRONT ON WEDNESDAY AND PRECIPITATION TIMING/COVERAGE ON WEDNESDAY
NIGHT.
SOME SCATTERED LIGHT SHOWERS ARE LIKELY ACROSS THE OUTLOOK AREA
THIS MORNING. REFLECTIVITY AT 09Z SHOWED SHOWERS ACROSS NORTH
CENTRAL NEBRASKA IN THE VICINITY OF A SURFACE BOUNDARY. THESE
SHOWERS WERE HEADING SOUTH. SATELLITE IMAGERY ALSO INDICATED SOME
LIGHTNING STRIKES. HRRR AND RUC BOTH HAVE REFLECTIVITY CONTINUING
THROUGH 18Z. GOING TO LEAVE POPS IN FOR THE MORNING HOURS WITH
CHANCES DIMINISHING AROUND NOON FOR OUR CWA AS THE COLD FRONT
TRANSITIONS FARTHER SOUTH OUT OF THE REGION. THIS AFTERNOON WILL
BE BREEZY WITH SUSTAINED NORTHERLY WIND SPEEDS AROUND 20 KNOTS AS
ATMOSPHERIC MIXING GETS TO UP TO AROUND 700MB. WIND GUSTS WILL BE
CLOSER TO 30 KNOTS THIS AFTERNOON. WIND SPEEDS ARE EXPECTED TO
CALM DOWN AROUND 23Z WITH A CONTINUING TREND THEREAFTER. NEAR
CRITICAL FIRE WEATHER CONCERNS WILL BE EXPECTED THIS AFTERNOON.
HOWEVER...RELATIVE HUMIDITY VALUES WILL BE BETWEEN 25 AND 35
PERCENT AT ITS DRIEST POINT THIS AFTERNOON...SO THE OUTLOOK AREA
SHOULD BE SAFE FROM ANY FIRE WEATHER HEADLINES AT THIS TIME.
KANSAS FUEL STATUS IS UNFAVORABLE AT THIS TIME...BUT NEBRASKA
STILL REMAINS FAVORABLE FOR FIRE GROWTH UNDER THE RIGHT
CONDITIONS.
WEDNESDAY HIGH TEMPERATURES WERE RAISED A LITTLE AHEAD OF THE COLD
FRONT...MAINLY FOR NORTHWESTERN PARTS OF THE CWA TO ACCOUNT FOR
THE SLOWER TIMING OF THE COLD FRONT. THE THOUGHT IS ENOUGH DAYTIME
HEATING WILL OCCUR BEFORE THE COLD AIR ADVECTION BEGINS TO TAKE
CONTROL OF TEMPERATURES. THE GFS...GEM...AND THE EC ARE STRONGER
THAN THE NAM WITH REGARDS TO SURFACE...1000MB-500MB...AND 1000MB-
850MB COLD AIR ADVECTION...AND THE BULK OF THIS COLD AIR ADVECTION
DOESN/T REACH THE CWA UNTIL 00Z. LOWERED LOW TEMPERATURES
OVERNIGHT TO ACCOUNT FOR THIS COLDER AIRMASS. THE
NAM...HOWEVER...IS MUCH QUICKER THAN THE OTHER MODELS PREVIOUS
MENTIONED WITH REGARDS TO THE TIMING OF THE COLD AIR. OF
COURSE...THIS SCENARIO COULD CHANGE AS IT HAS OVER THE LAST
SEVERAL DAYS. NEIGHBORS AGAINST OUR CWA GENERALLY LEANED TOWARDS
THE WARMER TEMPERATURES AHEAD OF THE COLD FRONT.
PRECIPITATION CHANCES ARE DECENT ON WEDNESDAY NIGHT AS THE
SREF...GFS...EC...AND NAM ARE ALL IN PRETTY GOOD AGREEMENT WITH
TIMING AND COVERAGE. THE COLD FRONT WILL BE THE MAIN FACTOR LEADING
TOWARDS PRECIPITATION TIMING ACROSS THE OUTLOOK AREA...AS ENOUGH
MOISTURE SHOULD BE PRESENT IN THE LOWER TO MID LEVELS FOR
STRATIFORM RAIN. SEVERE WEATHER IS NOT EXPECTED. CHANCES DIMINISH
LATER IN THE DAY AS THE SURFACE LOW PROGGED TO BE OVER THE GREAT
LAKES REGION PUSHES EASTWARD...WITH THE SOUTHEASTWARD EXTENDING
COLD FRONT FOLLOWING SUIT.
THE FOLLOWING CHANGES WERE ALSO MADE FROM THE PREVIOUS FORECAST.
LOWERED HIGH TEMPERATURES ON MONDAY AND IN RETURN LOWERED
TEMPERATURES THAT NIGHT. TUESDAY HIGH TEMPERATURES WERE RAISED
SLIGHTLY ACROSS THE CWA BUT DID NOT CHANGE LOWS ON WEDNESDAY.
WENT WITH THE LATEST RUNS OF THE BCCONSALL FOR HIGHS ON MONDAY AND
WENT WITH THE ADJMAVBC FOR TUESDAY HIGHS...WITH SOME SLIGHT
MODIFICATIONS. TEMPERATURES WERE LOWERED ON TUESDAY MORNING. LOW
TEMPERATURES WERE LOWERED SEVERAL DEGREES ON THURSDAY AS A RESULT
OF THE STRONGER COLD AIRMASS PROGGED TO ENTER THE OUTLOOK AREA.
.LONG TERM...THURSDAY THROUGH SUNDAY. TEMPERATURES WILL GENERALLY BE
10 TO 15 DEGREES BELOW NORMAL THROUGH THE PERIOD AND MAY EVEN
APPROACH 15 TO 20 DEGREES BELOW NORMAL ON SATURDAY BEHIND YET
ANOTHER STRONG COLD FRONT. NORMAL HIGHS ARE RIGHT AROUND 70
DEGREES AND WE WILL BE SEEING HIGHS PRIMARILY IN THE 50S. THE BEST
CHANCE FOR PRECIPITATION WILL BE FRIDAY NIGHT INTO SATURDAY AND WILL
NEED TO KEEP AN EYE ON PRECIPITATION TYPE.
THURSDAY...A FEW VERY LIGHT RAIN SHOWERS MAY LINGER OVER FROM
WEDNESDAY NIGHT PRIMARILY DURING THE MORNING HOURS FOR AREAS EAST OF
HIGHWAY 281. THE COLD FRONT WILL HAVE ALREADY PASSED THROUGH THE
ENTIRE CWA AND EXPECT COLD AIR ADVECTION THROUGH MUCH OF THE DAY
RESULTING IN HIGHS THAT ONLY REACH INTO THE 50S.
FRIDAY...TEMPERATURES WILL REMAIN COOL AND A REINFORCING COLD FRONT
WILL BE KNOCKING AT OUR DOOR BY LATE DAY...LIKELY TO SWING THROUGH
FRIDAY NIGHT. WILL KEEP FRIDAY DRY FOR NOW...BUT THERE ARE SOME
HINTS THAT SLIGHT POPS MAY BE NEEDED FOR LATE FRIDAY AFTERNOON AS
THE COLD FRONT NEARS.
FRIDAY NIGHT INTO SATURDAY...THERE WILL BE A DECENT CHANCE OF A
LIGHT COLD RAIN FRIDAY NIGHT INTO SATURDAY BEHIND THE COLD FRONT.
TEMPERATURES LATE FRIDAY NIGHT UNTIL JUST AFTER DAWN SATURDAY
MORNING WILL ONLY BE A FEW DEGREES ABOVE FREEZING ACROSS WESTERN
ZONES AND MAY BE COLD ENOUGH FOR A FEW WET SNOW FLAKES TO MIX IN.
WILL CONTINUE TO KEEP THE FORECAST ALL RAIN FOR NOW...BUT WILL NEED
TO CLOSELY MONITOR MODEL FORECAST TRENDS IN THE COMING DAYS. THE 00Z
GEM AND 00Z ECMWF ARE THE COLDEST AND WETTEST MODEL RUNS AND FOCUS
THE BEST CHANCE OF SEEING LIGHT PRECIPITATION OVER OUR WESTERN
COUNTIES AS WELL AS ACROSS NORTHERN KANSAS. EXPECT MODELS WILL
CONTINUE TO HAVE VARYING SWINGS IN FRONTAL POSITION UNTIL WE GET A
BIT CLOSER TO THE ACTUAL ARRIVAL OF THE FRONT. THE NEW CONSALL BLEND
WAS A GOOD DEAL COOLER THAN THE PREVIOUS FORECAST FOR SATURDAY AND
GIVEN THE CURRENT MODEL TRENDS DECIDED TO LOWER SATURDAY
TEMPERATURES EVEN FURTHER. AREAS THAT SEE LITTLE TO NO SUNSHINE MAY
NOT GET OUT OF THE 40S FOR HIGHS ON SATURDAY. HOWEVER...IF WE DO SEE
A LITTLE SUN THEN EXPECT HIGHS WILL MAKE THE 50S.
SUNDAY...DRY WEATHER WILL RETURN AND TEMPERATURES SHOULD SEE SOME
SLIGHT MODERATION WITH MORE SUNSHINE...ALTHOUGH HIGHS WILL LIKELY
STILL ONLY BE IN THE MID TO UPPER 50S.
&&
.PREV DISCUSSION... /ISSUED 1153 PM CDT SUN SEP 30 2012/
AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT KGRI
THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL BE
POSSIBLE AT THE TERMINAL...BUT NOTHING BELOW 10000FT AGL ARE
CURRENTLY FORECAST. THERE IS AN OUTSIDE CHANCE THAT MEASURABLE
RAINFALL COULD BE OBSERVED AT KGRI...PRIMARILY BETWEEN SUNRISE AND
LATE MORNING MONDAY...BUT AT THIS TIME THE CHANCES OF
PRECIPITATION BEING REALIZED AT KGRI ARE TOO LOW FOR INSERTION
INTO THE TAF. THE SURFACE WIND WILL REMAIN LIGHT AND VARIABLE
THROUGH 09Z BEFORE BECOMING MORE ESTABLISHED FROM THE
NORTH/NORTHWEST. A STRONG NORTH/NORTHWESTERLY SURFACE WIND WILL BE
REALIZED AT THE TERMINAL ON MONDAY...SUSTAINED NEAR 22KTS AND
GUSTING TO NEAR 29KTS. VISIBILITY RESTRICTIONS ARE NOT EXPECTED AT
KGRI THROUGH THE NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...GUERRERO
LONG TERM/AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1153 PM CDT SUN SEP 30 2012
.AVIATION...06Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT KGRI
THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL BE
POSSIBLE AT THE TERMINAL...BUT NOTHING BELOW 10000FT AGL ARE
CURRENTLY FORECAST. THERE IS AN OUTSIDE CHANCE THAT MEASURABLE
RAINFALL COULD BE OBSERVED AT KGRI...PRIMARILY BETWEEN SUNRISE AND
LATE MORNING MONDAY...BUT AT THIS TIME THE CHANCES OF
PRECIPITATION BEING REALIZED AT KGRI ARE TOO LOW FOR INSERTION
INTO THE TAF. THE SURFACE WIND WILL REMAIN LIGHT AND VARIABLE
THROUGH 09Z BEFORE BECOMING MORE ESTABLISHED FROM THE
NORTH/NORTHWEST. A STRONG NORTH/NORTHWESTERLY SURFACE WIND WILL BE
REALIZED AT THE TERMINAL ON MONDAY...SUSTAINED NEAR 22KTS AND
GUSTING TO NEAR 29KTS. VISIBILITY RESTRICTIONS ARE NOT EXPECTED AT
KGRI THROUGH THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 1012 PM CDT SUN SEP 30 2012/
UPDATE...KUEX INDICATES ANY LINGERING CONVECTION ACROSS THE REGION
HAS FINALLY PUSHED OUT OF OUR CWA. LOSS OF DIABATIC HEATING SHOULD
PREVENT ANY ADDITIONAL CONVECTIVE ACTIVITY FROM BEING REALIZED
THROUGH AT LEAST 06Z. BEYOND 06Z HOWEVER...A MID LEVEL TROUGH
AXIS...CURRENTLY OVER THE NORTHERN PLAINS...WILL PUSH
EAST/SOUTHEAST WITH PERHAPS ENOUGH MID LEVEL THERMAL ADVECTION AND
DPVA FOR ADDITIONAL PRECIPITATION PRODUCTION OVER OUR AREA.
ALSO...EVENING UPPER AIR ANALYSIS INDICATES A ~100KT UPPER LEVEL
JET STREAK OVER MONTANA AND WYOMING. THIS UPPER LEVEL JET STREAK
IS EXPECTED TO MOVE SOUTHEAST TONIGHT...WITH THE LEFT-FRONT
QUADRANT OF THIS JET STREAK PERHAPS PROVIDING ENOUGH OF AN
INDIRECT THERMAL CIRCULATION THUS ALSO ENHANCING CHANCES FOR
PRECIPITATION AFTER 06Z. QPF FIELDS FROM THE NAM...OPERATIONAL
GFS...EC AND SREF-MEAN ALL ALSO SUGGEST LIGHT PRECIPITATION WILL
BE REALIZED OVER OUR WEST/NORTHWESTERN CWA AND AS A RESULT OF ALL
THIS...WENT AHEAD CONTINUED CARRYING 20% ACROSS OUR WEST/NORTHWEST
06Z-12Z. INCREASING MID LEVEL LAPSE RATES WITH THE APPROACH OF MID
LEVEL TROUGH AXIS WILL PROMOTE AT LEAST MODEST POTENTIAL
INSTABILITY...WITH THE NAM AND OPERATIONAL GFS BOTH SUGGESTING
DEEP LAYER MUCAPE VALUES OF ~50J/KG OVER THE AREA TONIGHT. GIVEN
ALL THIS...CERTAINLY DO NOT ANTICIPATE MUCH CONVECTION BUT AN
ISOLATED THUNDERSTORM OR TWO CANNOT BE RULED OUT AND WILL CONTINUE
CARRYING THUNDER MENTION IN THE FORECAST OVERNIGHT.
PREV DISCUSSION... /ISSUED 356 PM CDT SUN SEP 30 2012/
SHORT TERM...THROUGH LATE MONDAY AFTERNOON. THERE ARE TWO PRIMARY
ISSUES AT HAND DURING THE NEXT 24 HOURS...THE FIRST BEING A
POSSIBLE BUT STILL FAIRLY UNCERTAIN RISK FOR A FEW STRONG
THUNDERSTORMS ACROSS THE FAR WESTERN CWA LATE THIS AFTERNOON INTO
THIS EVENING...AND THE SECOND MAIN ISSUE BEING ELEVATED TO NEAR-
CRITICAL FIRE DANGER ON MONDAY AFTERNOON. ALSO OF CONCERN IS
TRYING TO FIGURE OUT HOW MUCH POST-FRONTAL RAIN WILL DEVELOP
MAINLY DURING THE MORNING HOURS MONDAY. FOR ALL FIRE WEATHER
DISCUSSION PLEASE SEE THE SEPARATE SECTION BELOW.
20Z OBJECTIVE SURFACE ANALYSIS INDICATES A NORTH-SOUTH TROUGH AXIS
EXTENDING FROM NORTH CENTRAL NEB TO NORTHWEST KS...SEPARATING A
LIGHT/VARIABLE TO LIGHT/SOUTHERLY WIND REGIME TO THE EAST FROM A
STRONGER NORTHERLY COMPONENT TO THE WEST. WITHIN AND NEAR THE
IMMEDIATE TROUGH AXIS...INCLUDING MAINLY THE WESTERN 1/4 OF THE
CWA...SURFACE DEWPOINTS HAVE INCREASED TODAY BETWEEN THE MID 40S
AND MID 50S...AND THERE ARE EVEN NOW SIGNS OF A LOW LEVEL CUMULUS
FIELD STARTING TO SHOW ITS HAND. MEANWHILE...ACROSS THE MAJORITY
OF THE CENTRAL/EASTERN CWA...DEWPOINTS HAVE AGAIN DONE THEIR
SEEMINGLY DAILY CRASH WELL INTO THE 30S IN MOST AREAS...ONCE AGAIN
BELOW FORECAST VALUES. ACTUAL HIGH TEMPS ARE WORKING OUT PRETTY
WELL...WITH NEARLY ALL AREAS WITHIN A FEW DEGREES OF 80. OTHER
THAN THE NEWLY DEVELOPED CUMULUS FIELD IN PARTS OF THE
WEST...VISIBLE SATELLITE SHOWS THAT MOST OF THE THICKER HIGH
CIRRUS FROM EARLIER TODAY HAS VACATED EAST OF THE CWA...WHILE A
FEW LEGITIMATE SHOWERS/NEWLY DEVELOPED THUNDERSTORMS ARE ALREADY
OCCURRING BOTH SOUTHWEST AND NORTHWEST OF THE CWA IN NORTH CENTRAL
NEB AND NORTHWEST KS. WATER VAPOR SATELLITE IMAGERY AND SHORT TERM
MODEL DATA DEPICTS AN ALMOST DUE NORTHERLY MID LEVEL FLOW OVER THE
CWA...WITH THE PRIMARY SYNOPTIC SCALE LOWS CONSISTING OF A DEEP
CLOSED CIRCULATION OVER THE NORTHEAST STATES...A VERY SLOW MOVING
CLOSED MID LEVEL LOW CENTERED OVER EASTERN OK...AND A PROGRESSIVE
OPEN WAVE AND ASSOCIATED UPPER LEVEL JET STREAK DIPPING OUT OF
SOUTHERN CANADA INTO THE MT/ND/SD REGION.
STARTING WITH THE MOST IMMEDIATE ISSUE OVER THE NEXT 6 HOURS OR
SO...HAVE MAINTAINED 20-30 PERCENT SHOWER/STORM CHANCES LATE THIS
AFTERNOON INTO THIS EVENING FOR AREAS PRIMARILY WEST OF AN ORD-
KEARNEY-PLAINVILLE LINE AND ESPECIALLY DAWSON...GOSPER AND FURNAS
COUNTIES WHICH ARE ABOUT THE ONLY PARTS OF THE CWA WITHIN THE
MOIST AXIS AND RESULTANT INSTABILITY AXIS...WITH 20Z MESOSCALE
ANALYSIS SUGGESTING THAT A NARROW CORRIDOR OF MLCAPE AT LEAST INTO
THE 500-1000 J/KG RANGE IS NOW IN PLACE IN THIS AREA.
MEANWHILE...THE EASTERN HALF TO TWO THIRDS OF THE CWA HAS
ESSENTIALLY NO CONVECTIVE INSTABILITY AT THIS HOUR...AND THIS WILL
NOT CHANGE HEADING INTO THE EVENING HOURS. WITH DEEP LAYER 0-6KM
BULK SHEAR ONLY AVERAGING AROUND 20 KT...AM NOT EXPECTING A
LEGITIMATE SEVERE THREAT WITH THIS EVENT...BUT THERE IS MORE THAN
ENOUGH INSTABILITY TO GET SOME SEMI-ORGANIZED MULTICELL STORMS OR
A FEW QUASI-LINEAR CLUSTERS GOING...WITH SMALL HAIL AND WINDS TO
AROUND 50 MPH VERY POSSIBLE. FOLLOWING THE REFLECTIVITY PROGS OF
THE LATEST HRRR AND ALSO 12Z 4KM-WRF NMM...THERE COULD BE A DECENT
LULL IN SHOWER/STORM ACTIVITY ONCE THE MID EVENING HOURS ARRIVE
AND THE LOW LEVELS START TO STABILIZE A BIT. FOR THE LATE NIGHT
06Z-12Z POP/WEATHER GRIDS...OPTED TO BLANKET A 20 PERCENT CHANCE
OF SHOWERS/ISOLATED THUNDER ACROSS ROUGHLY THE NORTHWEST 2/3 OF
THE CWA INCLUDING THE TRI-CITIES...IN ASSOCIATION WITH INCREASING
SYNOPTIC SCALE FORCING AND A RESULTANT SOUTHWEST-NORTHEAST BAND OF
MID LEVEL SATURATION DEVELOPING AHEAD OF THE PARENT SHORTWAVE
DROPPING SOUTHEAST ACROSS THE DAKOTAS. THERE ARE PLENTY OF
QUESTIONS REGARDING HOW WIDESPREAD THIS LATE NIGHT PRECIPITATION
MIGHT BE...WITH BOTH THE LATEST ECMWF/GFS SUGGESTING IT COULD BE
NARROW BUT FAIRLY SOLID BAND OF MEASURABLE RAIN...WHILE THE NAM IS
MUCH DRIER THROUGH SUNRISE ALONG WITH THE 4KM WRF-NMM. AT ANY
RATE...NOT EXPECTING ANY LATE NIGHT STORMS TO BE ALL THAT STRONG
LET ALONE SEVERE. KEPT LOW TEMPS TONIGHT SIMILAR TO PREVIOUS
FORECAST AND MET/MAV GUIDANCE BLEND...GENERALLY RIGHT AROUND 50.
FOR THE MONDAY DAYTIME HOURS...BY SUNRISE A WELL DEFINED SURFACE
COLD FRONT WILL BE IN THE PROCESS OF CROSSING THROUGH THE
CWA...AND REALLY THE MOST PROMINENT WEATHER FEATURE THROUGH THE
DAY WILL BE THE QUITE BREEZY TO WINDY CONDITIONS IN ITS WAKE...AS
NORTH WINDS AVERAGE 20-25 MPH SUSTAINED THROUGH MOST OF THE DAY
AND GUSTS 30-35 MPH...BUT SHOULD AVERAGE AT LEAST 5 MPH SHORT OF
ADVISORY CRITERIA. AS FOR PRECIP CHANCES DURING THE DAY...AM
STARTING TO WONDER IF THE FORECAST 20 PERCENT CHANCE OF SHOWERS
DURING THE MORNING HOURS ACROSS ROUGHLY THE SOUTHEAST 2/3 OF THE
CWA IS HIGH ENOUGH...AS THE LATEST ECMWF/GFS ARE NOW SHOWING
POTENTIAL FOR A MORE ORGANIZED NARROW BAND OF LIGHT BUT MEASURABLE
RAINFALL PASSING THROUGH FROM NORTHWEST TO SOUTHEAST.
HOWEVER...WITH MOST OF THE SATURATION ABOVE 700MB AM HESITANT TO
GET TOO CARRIED AWAY WITH POPS...ESPECIALLY GIVEN THAT BOTH THE
18Z NAM AND 12Z WRF-NMM SHOW A MUCH MORE HIT AND MISS...LESS
ORGANIZED BAND. STAYED WITH THE THEME FROM PREVIOUS FORECAST...AND
LEFT THIS MORNING PRECIP RISK AS JUST SHOWERS WITH NO THUNDER
MENTION...ALTHOUGH SUPPOSE A FEW ROGUE LIGHTNING STRIKES ARE NOT
OUT OF THE QUESTION. ALSO IN LINE WITH PREVIOUS FORECAST...LEFT
THE AFTERNOON 18Z-00Z PERIOD PRECIP FREE...BUT THERE A FEW HINTS
IN LATEST MODELS THAT A FEW SHOWERS COULD LINGER INTO THE
AFTERNOON PERIOD ACROSS THE FAR EASTERN/SOUTHERN CWA...AND THE
NEXT SHIFTS WILL WANT TO SEE IF MAYBE THIS RAIN MENTION NEEDS
EXTENDED IN TIME A BIT. BY THE MID AFTERNOON HOURS
HOWEVER...CONFIDENCE IS FAIRLY HIGH THAT THE ENTIRE CWA SHOULD BE
RAIN-FREE AND SEEING PLENTY OF SUN...AS THE PARENT MID LEVEL
TROUGH AXIS AND RESULTANT MID LEVEL SATURATION STARTS TO FOCUS
EAST OF THE AREA. TEMP WISE...LOWERED HIGHS 2-3 DEGREES FROM
PREVIOUS IN MOST AREAS...FOLLOWING THE RAW 12Z NAM SOLUTION
CLOSELY AND RANGING FROM LOW 70S NORTHWEST TO UPPER 70S SOUTHEAST.
DID LOWER DEWPOINTS SEVERAL DEGREES ESPECIALLY DURING THE MID-LATE
AFTERNOON WITH WIDESPREAD LOW-MID 30S AND EVEN UPPER 20S
NORTHWEST.
LONG TERM...MONDAY NIGHT THROUGH SUNDAY. SURFACE HIGH PRESSURE
BUILDS SOUTH BEHIND THE COLD FRONTAL BOUNDARY...WITH RIDGE AXIS
SETTLING ACROSS NEBRASKA AND WESTERN KANSAS MONDAY NIGHT. THE
RIDGE DOES WEAKEN...HOWEVER IN THE COOLER...DRY AIRMASS WITH LIGHT
WINDS AND GOOD RADIATIONAL CONDITIONS...WE ARE LOOKING AT THE
POTENTIAL FOR SOME CHILLY OVERNIGHT LOW TEMPERATURES. SFC DPS DROP
TO THE 20S AND LOWER 30S AND ITS LOOKING LIKE OVERNIGHT LOWS WILL
AGAIN FALL INTO THE TEMPERATURE RANGE FAVORABLE FOR FROST...IN THE
LOW/MID 30S. THESE LOCATIONS HAVE ALREADY EXPERIENCED SIMILAR LOW
TEMPS THIS SEASON OR COLDER AND WILL NOT MENTION FROST...BUT WILL
NEED TO MONITOR FOR FREEZE CONDITIONS FOR LOCATIONS THAT HAVE YET
TO FREEZE.
THE SURFACE RIDGE AXIS WASHES OUT/SHIFTS EAST ON TUESDAY WITH
RETURN FLOW SETTING UP AHEAD OF A DEEPENING SURFACE LOW IN
MANITOBA...ASSOCIATED WITH UPSTREAM TROUGH ALONG THE US/CANADIAN
BORDER. SHORTWAVE RIDGING NOSES ONTO THE CENTRAL PLAINS IN BETWEEN
UPPER LOW TO THE SOUTHEAST AND TROUGH ENTERING THE NORTHERN
ROCKIES. TEMPERATURES WILL MODERATE TUESDAY...BUT WITH COOL START
TO THE DAY AND LESS MIXING WILL AIM FOR HIGHS IN THE MID 70S VS
NEAR 80F.
WEDNESDAY IS REALLY ONE OF THE TRICKIER DAYS DUE TO TIMING OF COLD
FRONTAL PASSAGE. UPPER LOW PRESSURE TROUGH REACHES THE NORTHERN
PLAINS AND ROCKIES WITH THE ASSOCIATED COLD FRONT MOVING INTO
WESTERN NEBRASKA BY 12Z WEDNESDAY. THERE ARE IMPRESSIVE PRESSURE
RISES OF 10+MB PROGGED BEHIND THE FRONT IN THE NEB PANHANDLE. IN
GENERAL MODELS HAVE TRENDED FASTER WITH FRONTAL PASSAGE WITH THE
BOUNDARY THROUGH AT LEAST OUR WESTERN THIRD CWA...IF NOT HALF OF
THE CWA BY 18Z. WITH THE FASTER TREND...HAVE SHARPENED TEMP
GRADIENT NW/SE WITH AND LOWERED HIGHS IN OUR NORTHWEST TO THE LOW
70S. IF FRONT TRENDS ANY FASTER...COULD SEE TEMPS FALLING DURING
THE AFTERNOON AND OUR NW ZONES MAY NOT REACH 70F. THIS BEING
SAID...IF FRONT IS SLOWER AND MORE IN LINE WITH ECMWF VS
NAM/GFS...TEMPS MAY BE WARMER THAN CURRENT FORECAST.
PCPN CHCS INCREASE WEDNESDAY NIGHT IN INCREASING UPPER DYNAMICS AS
TROUGH CROSSES THE CENTRAL PLAINS. THE 12Z GFS AND GEM ARE DEEPER
WITH TROUGH THAN THE MORE PROGRESSIVE 00Z AND 12Z RUNS OF THE
ECMWF. HAVE CONCERNS THAT ECMWF IS TOO PROGRESSIVE WITH
SYSTEM...AND GFS/GFS ENSEMBLE LOOKS TO BE DECENT COMPROMISE
BETWEEN ECMWF AND GEM SOLUTIONS. IF THE DEEPER TROUGH SOLUTIONS
VERIFY WE COULD SEE A DECENT CHC FOR RAIN...BUT WOULD LIKE TO SEE
MORE CONSISTENCY BEFORE RAISING POPS. THE TROUGH AXIS DEPARTS
THURSDAY MORNING...WITH PCPN ENDING W/E.
THEREAFTER FOR THE REMAINDER OF THE WORKWEEK AND INTO NEXT
WEEKEND...PATTERN WILL BE INFLUENCED BY UPPER TROUGH ENCOMPASSING
MUCH OF THE INTERIOR CONUS. TEMPERATURES WILL REMAIN BELOW NORMAL
AND THERE WILL BE SOME HIT OR MISS CHCS FOR RAIN SHOWERS AS ENERGY
TRANSLATES THRU FLOW.
FIRE WEATHER...ALTHOUGH FIRE WEATHER CONDITIONS ARE CURRENTLY
FORECAST TO FALL JUST A BIT SHORT OF CRITICAL THRESHOLDS ON MONDAY
AFTERNOON THANKS TO RELATIVE HUMIDITY VALUES HOLDING AT LEAST
SLIGHTLY ABOVE 20 PERCENT...THE CURRENTLY FORECAST COMBINATION OF
SUSTAINED NORTHERLY WINDS AROUND 25 MPH/GUSTS 30-35 MPH AND
RELATIVE HUMIDITY VALUES FALLING INTO THE 22-26 PERCENT RANGE FOR
A FEW HOURS IS MORE THAN ENOUGH TO WARRANT THE CONTINUATION OF
ELEVATED TO NEAR-CRITICAL FIRE DANGER WORDING IN THE HAZARDOUS
WEATHER OUTLOOK. BASED ON RAINFALL TRENDS OVER THE PAST MONTH AND
OFFICIAL FIRE GROWTH FUEL STATUS FROM FIRE MANAGERS...THE NEBRASKA
COUNTIES WILL GENERALLY BE UNDER THE GUN MORE SO THAN KS. ONE
FACTOR THAT MIGHT BE JUST ENOUGH TO SPARE US FROM DROPPING TO 20
PERCENT OR LOWER RELATIVE HUMIDITY IS THAT HIGH TEMPS WERE LOWERED
2-3 DEGREES FROM PREVIOUS FORECAST. HOWEVER...DEWPOINTS WERE ALSO
DROPPED AT LEAST 5 DEGREES FROM PREVIOUS FORECAST IN MOST AREAS
DURING THE KEY MID-LATE AFTERNOON HOURS...NOW ADVERTISED BETWEEN
THE UPPER 20S AND MID 30S IN MOST COUNTIES. NEXT FEW SHIFTS WILL
HAVE TO KEEP A CLOSE EYE ON THESE DEWPOINT/RH TRENDS...AS ONLY A
SLIGHT DOWNWARD ADJUSTMENT COULD REQUIRE HEADLINE ISSUANCE FOR AT
LEAST A SMALL PART OF MAINLY THE WESTERN CWA. LOOKING BEYOND
MONDAY...WILL ALSO HAVE TO KEEP AN EYE ON WEDNESDAY AFTERNOON FOR
OUR NEXT POTENTIALLY NEAR-CRITICAL FIRE DANGER SITUATION...AS
NORTHERLY WINDS INCREASE AGAIN BEHIND THE NEXT COLD FRONT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION/UPDATE...BRYANT
SHORT TERM/FIRE WEATHER...PFANNKUCH
LONG TERM...FAY
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1205 AM CDT MON OCT 1 2012
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
PREDOMINANTLY A VFR FORECAST THE NEXT 24 HOURS. COULD SEE SOME
MVFR VISIBILITIES AT KBBD FOR A COUPLE OF HOURS EARLY THIS
MORNING...OTHERWISE VFR EXPECTED. A FEW SHOWERS MAY AFFECT THE
KSJT AND KSOA TERMINALS JUST BEFORE DAYBREAK WITH ANOTHER CHANCE
FOR SHOWERS AND THUNDERSTORMS ACROSS MOST OF THE TERMINALS MONDAY
AFTERNOON. WENT WITH VICINITY SHOWERS MONDAY AFTERNOON FOR NOW AND
WILL LEAVE MENTION OF THUNDER OUT OF THE FORECAST DUE TO
TIMING/CONFIDENCE ISSUES.
&&
.PREV DISCUSSION... /ISSUED 1023 PM CDT SUN SEP 30 2012/
UPDATE...
TO ADD SLIGHT CHANCE POPS AND LOWER OVERNIGHT LOW TEMPERATURES...
DISCUSSION...
DISTURBANCES CONTINUE TO ROTATE AROUND AN UPPER LEVEL LOW CENTERED
OVER THE ARKLATEX REGION. THIS DISTURBANCES ARE PRODUCING
SCATTERED SHOWERS AND THUNDERSTORMS MOVING FROM NORTH TO
SOUTH...ACROSS THE TEXAS PANHANDLE AND PARTS OF WEST TEXAS. THERE
IS CURRENTLY A LINE OF THUNDERSTORMS OVER THE PERMIAN BASIN...AND
THIS WILL LIKELY CLIP PARTS OF CROCKETT COUNTY. IN
ADDITION...ANOTHER AREA OF THUNDERSTORMS IS QUICKLY MOVING SOUTH
THROUGH THE PANHANDLE. THIS MAY AFFECT...AT LEAST THE WESTERN
PARTS OF THE CWA...AND THIS IS REFLECTED IN THE LATEST HRRR MODEL
RUN. I ADDED IN A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
OVERNIGHT...FOR MAINLY THE WESTERN HALF OF THE AREA.
FINALLY...I LOWERED TEMPERATURES BY A FEW DEGREES ACROSS THE
AREA...AS WINDS REMAIN LIGHT AND DEWPOINT TEMPERATURES DROP INTO THE
MID AND UPPER 50S. OTHERWISE...NO OTHER CHANGES NEEDED AT THIS
TIME.
PREV DISCUSSION... /ISSUED 706 PM CDT SUN SEP 30 2012/
DISCUSSION...
SEE AVIATION DISCUSSION BELOW.
AVIATION...
VFR CONDITIONS WILL PREVAIL OVERNIGHT. BBD MAY SEE A VICINITY
SHOWER OVER THE NEXT TWO HOURS...AND SOME FOG DEVELOPING AFTER 09Z
FOR ABOUT TWO HOURS. HIGH RESOLUTION RAP MODEL BRINGS THE ACTIVITY
IN THE PANHANDLE NEAR THE WESTERN TERMINALS LATER TONIGHT...BUT DO
NOT HAVE CONFIDENCE ENOUGH TO MENTION IN THE TAFS FOR SJT AND SOA.
MODELS DEVELOP SHOWERS AGAIN TOMORROW AFTERNOON...SO HAVE INCLUDED
VCSH FOR ABI...SOA...AND SJT.
PREV DISCUSSION... /ISSUED 346 PM CDT SUN SEP 30 2012/
SHORT TERM...
CLOUD COVERAGE IS ON A DECREASING TREND AND EXPECT THIS TO CONTINUE
THROUGH THIS EVENING ACROSS OUR AREA. SOMEWHAT GUSTY NORTH WINDS
WILL DIMINISH AND BECOME LIGHT BY EARLY TONIGHT. THE CHANCE FOR
CONVECTION WHICH DEVELOPS IN NORTHEASTERN NEW MEXICO/SOUTHEASTERN
COLORADO TO SURVIVE LONG ENOUGH TO MOVE SOUTH-SOUTHEAST INTO OUR
AREA LATER TONIGHT LOOKS TOO LOW TO INCLUDE A MENTIONABLE POP...SO
WILL LEAVE OUT FOR NOW. ANTICIPATE THAT SOME MIDDLE AND UPPER LEVEL
CLOUDS /FROM UPSTREAM CONVECTIVE DEVELOPMENT/ WILL TRAVERSE OUR
COUNTIES OVERNIGHT. CANNOT RULE OUT A POSSIBILITY FOR SOME PATCHY FOG
DEVELOPMENT LATER TONIGHT WITH WEAK WINDS AND TEMPERATURES COOLING
TO NEAR THE DEWPOINT VALUES. WITH THIS BEING THE SECOND NIGHT REMOVED
FROM THE RAINFALL EVENT HOWEVER...AND WITH SOME INCREASE IN CLOUD
COVER POSSIBLE...NOT ENOUGH CONFIDENCE TO MENTION IN THE FORECAST AT
THIS TIME. THIS CAN BE MONITORED THIS EVENING.
ON MONDAY...HAVE INCLUDED A SLIGHT CHANCE POP FOR SHOWERS AND
THUNDERSTORMS ACROSS MOST OF OUR AREA. AN UPPER JET MAX WILL DIVE
SOUTH THROUGH THE HIGH PLAINS AROUND THE BACK SIDE OF AN UPPER
TROUGH...PLACING OUR AREA IN THE LEFT FRONT QUADRANT DURING THE
AFTERNOON. DURING THAT TIME...COLD AIR ADVECTION ALOFT /500MB
TEMPERATURES DROPPING TO MINUS 13 TO MINUS 15 DEG C / WILL BE
COINCIDENT WITH SURFACE TEMPERATURES WARMING TO OR ABOVE 80 DEGREES.
LONG TERM...
THIS WEEK WILL FEATURE SEASONABLE TEMPERATURES AS THE UPPER LEVEL
JET STREAM CONTINUES TO DIVE SOUTH INTO THE U.S. PUSHING COLD FRONTS
INTO WC TX. THIS PATTERN CAN MAKE IT VERY DIFFICULT TO PREDICT
TEMPERATURES THOUGH. THE CANADIAN/GFS/AND ECMWF ALL INDICATE AN
AMPLIFICATION IN THE UPPER RIDGE ACROSS ACROSS THE WESTERN PROVINCES
OF CANADA THIS WEEK. THIS TYPE OF PATTERN IS VERY FAVORABLE FOR
AT LEAST A COUPLE OF SURGES OF CANADIAN AIRMASSES TO PLUNGE SOUTH
INTO THE U.S. AND EVENTUALLY WC TX.
AFTER A BEAUTIFUL WEATHER DAY ON TUESDAY...A WEAK SURFACE HIGH
PRESSURE SYSTEM WILL MOVE EAST OF THE REGION TUESDAY NIGHT AND
RESULT IN A WARM SOUTHERLY FLOW INTO WEDNESDAY WHEN TEMPERATURES
COULD REACH THE MID TO UPPER 80S. AS A STRONG SHORTWAVE TROUGH MOVES
ACROSS THE CENTRAL PLAINS WEDNESDAY NIGHT...IT WILL SEND A CANADIAN
COLD FRONT INTO THE AREA ON THURSDAY. FOR THIS REASON...TRENDED
COOLER FOR THE BIG COUNTRY ON THURSDAY AND FORECASTED HIGHS MAY BE
SLIGHTLY COOLER.
AFTER A SLIGHT WARMING TREND ON FRIDAY...THE NEXT CANADIAN FRONT
IS PROGGED TO ENTER THE NORTHERN PART OF THE BIG COUNTRY SATURDAY
MORNING...AND THEN SWEEP THROUGH THE REGION DURING THE DAY. A FEW
THUNDERSTORMS MAY FORM ALONG THE FRONT. THE MODELS PROG STRATIFORM
PRECIPITATION TO DEVELOP SATURDAY NIGHT INTO SUNDAY AS THE RIGHT
REAR ENTRANCE OF A JET MAX CAUSES AN ISENTROPIC WARM AIR ADVECTION
PATTERN TO DEVELOP ATOP THE COLD AIR.
THE CHALLENGE WITH THIS FRONT WILL BE HIGH TEMPERATURES ON
SUNDAY. SINCE THERE IS STILL QUITE A BIT OF UNCERTAINTY....WILL
START WITH HIGHS NEAR 70. BUT THESE TEMPS MAY BE COOLER. WENT
AHEAD AND ADDED SLIGHT CHANCE POPS FOR LIGHT RAIN AND MOSTLY
CLOUDY SKIES FOR SATURDAY NIGHT INTO SUNDAY.
26
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 78 58 81 54 77 / 10 10 20 5 5
SAN ANGELO 79 58 82 56 78 / 10 20 20 10 0
JUNCTION 78 58 82 53 81 / 10 10 20 10 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/24
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1140 PM CDT SUN SEP 30 2012
.AVIATION...
/06 UTC TAFS/ THUNDERSTORMS CONTINUE TO RACE SOUTH OVER THE SOUTHERN
TX PANHANDLE AND WILL MOVE SOUTH OF THE KAMA TERMINAL SHORTLY. GUSTY
WINDS ARE STILL POSSIBLE NEAR THE TERMINAL SO WILL LET THE CURRENT
AWW CONTINUE UNTIL IT EXPIRES AT 05Z. A WEAK COLD FRONT WILL BE
MOVING ACROSS THE TERMINALS SHORTLY...WITH WINDS SHIFTING TO THE
NORTHWEST TO NORTH. DESPITE THE RECENT RAINFALL...NOT EXPECTING AREAS
OF FOG TO DEVELOP AS NORTHERLY LOW LEVEL FLOW WILL DRAW IN THE DRIER
AIR UPSTREAM. NORTHERLY WINDS WILL CONTINUE THROUGH THE VALID TAF
FORECAST PERIOD ALTHOUGH WILL SEE WINDS INCREASE TO AROUND 20-25 KTS
WITH GUSTS UP TO 35 KTS BY 14Z MONDAY. WINDS WILL DIMINISH IN TYPICAL
DIURNAL FASHION AFTER 00Z TUESDAY. THERE IS A SLIGHT CHANCE FOR
SHOWERS AND THUNDERSTORMS MONDAY AFTERNOON AND EVENING BUT CONFIDENCE
IS TOO LOW TO MENTION IN THE FORECAST.
CLK
&&
.PREV DISCUSSION... /ISSUED 640 PM CDT SUN SEP 30 2012/
AVIATION...
/00 UTC TAFS/ ONGOING CONVECTION CONTINUES TO MOVE SOUTH ACROSS THE
WESTERN TX PANHANDLE...AND ARE NOT EXPECTED TO IMPACT KAMA/KDHT.
ADDITIONAL SHOWERS AND THUNDERSTORMS WERE DEVELOPING IN SOUTHWESTERN
KS AND ARE ALSO MOVING TO THE SOUTH. HAVE LEFT OUT MENTION OF TSRA IN
AT KGUY AS LATEST HRRR AND TT WRF SHOW THESE STORMS WILL MOVE EAST OF
THE TERMINAL. WILL CONTINUE TO MONITOR AND AMEND AS NECESSARY. LIGHT
AND VARIABLE WINDS THIS EVENING WILL SHIFT TO THE NORTH BEHIND A WEAK
COLD FRONT THAT WILL MOVE ACROSS THE TERMINALS THIS EVENING. WINDS
WILL REMAIN OUT OF THE NORTH THROUGH THE REMAINDER OF THE FORECAST
BUT WILL INCREASE TO AROUND 20-25 KTS SUSTAINED WITH GUSTS UP TO 35 KTS
AS THE PRESSURE GRADIENT TIGHTENS BEHIND THIS FRONT. VFR CONDITIONS
ARE EXPECTED THROUGH THE VALID TAF FORECAST PERIOD.
CLK
PREV DISCUSSION... /ISSUED 337 PM CDT SUN SEP 30 2012/
DISCUSSION...
PRECIPITATION CHANCES THROUGH TOMORROW AND COOLER TEMPERATURES LATE
WEEK ARE THE MAIN FORECAST CONCERNS.
ISOLATED TO SCATTERED THUNDERSTORMS CONTINUE TO DEVELOP FROM THE
NORTHWEST TX PANHANDLE AND NORTHEAST NM...NORTH INTO THE CENTRAL HIGH
PLAINS. A MID-LEVEL SHORTWAVE DIVING DOWN WITHIN THE NORTH/NORTHWEST
FLOW ALOFT WAS ACTING ON AN INCREASINGLY UNSTABLE AIRMASS TO TRIGGER
THIS CONVECTION. A WEAK SURFACE TROUGH IS ALSO DRAPED NORTH/NORTHEAST
TO SOUTH/SOUTHWEST ACROSS THE AREA...WHICH MAY ALSO HELP TO FOCUS
CONVECTION THIS AFTERNOON AND EVENING. LAPS/RUC ANALYSIS DATA SHOW
A CORRIDOR OF 1000-1500 MLCAPES ACROSS THE PANHANDLES...WITH FAIRLY
WEAK DEEP LAYER SHEAR IN THE 20-30 KT RANGE. GIVEN THIS
COMBINATION...COULD SEE A FEW STRONG TO MARGINALLY SEVERE STORMS
THROUGH THE EVENING HOURS. PRECIPITATION IS LIKELY TO WANE LATE THIS
EVENING...BUT WITH THE NOSE OF THE UPPER JET CURRENTLY DIGGING SOUTH
ALONG THE LEE OF THE ROCKIES DRAWING CLOSER TO THE PANHANDLES
OVERNIGHT...CAN/T RULE OUT A FEW LINGERING SHOWERS/WEAK THUNDERSTORMS
ACROSS THE EASTERN HALF OF THE AREA OVERNIGHT.
THIS DIGGING UPPER JET AND ANOTHER SHORTWAVE TROUGH DIVING SOUTH
ACROSS THE PLAINS WILL HELP TO SEND A WEAK COLD FRONT SOUTH THROUGH
THE CWA LATE TONIGHT INTO MONDAY MORNING. WON/T SEE MUCH OF A COOL
DOWN BEHIND THE FRONT...BUT BREEZY NORTHERLY WINDS WILL DEVELOP
BEHIND THE FRONT. THE LFQ OF AN 80-100 KT NORTH/SOUTH UPPER JET WILL
SLIDE ACROSS THE PANHANDLES ON MONDAY...ACTING WITH SOME LOW TO MID-
LEVEL FRONTOGENESIS TO SUPPORT A CHANCE OF A FEW SHOWERS AND WEAK
THUNDERSTORMS /AS INSTABILITY REMAINS WEAK/ ACROSS MOST OF THE CWA.
ANY PRECIPITATION WILL SLIDE EAST/SOUTHEAST OF THE AREA BY EARLY
MONDAY EVENING.
DRY AND WARMING CONDITIONS ARE THEN ON TAP TUESDAY AND WEDNESDAY
IN BETWEEN COLD FRONTS. A DEEPENING LEE TROUGH AHEAD OF THE NEXT UPPER
TROUGH DIGGING ACROSS THE NORTHERN AND CENTRAL ROCKIES WILL HELP
TEMPS REBOUND INTO THE 80S BY WEDNESDAY. NEXT COLD FRONT WILL PUSH
THROUGH WEDNESDAY NIGHT AS THE PARENT UPPER TROUGH PUSHES ACROSS THE
NORTHERN AND CENTRAL PLAINS...KNOCKING HIGHS BACK INTO THE 60S AND
70S ON THURSDAY. NOT EXPECTING ANY PRECIP WITH THE FRONT AS MOISTURE
WILL BE LACKING AND UPPER DYNAMICS STAY TO OUR NORTH.
FRIDAY WILL BRING A BRIEF REBOUND IN TEMPS AHEAD OF THE NEXT STRONGER
COLD FRONT EXPECTED TO PLOW THROUGH FRIDAY NIGHT. AS THE ASSOCIATED
UPPER TROUGH/JET DIG ACROSS THE NORTHERN AND CENTRAL
PLAINS...FORCING FROM THE RRQ OF THE UPPER JET WILL GRAZE THE
NORTHEAST CWA FRIDAY NIGHT...POSSIBLE TEAMING WITH THE FRONT TO
BRING A FEW SHOWERS TO THIS PORTION OF THE AREA. BEYOND THAT...RAIN
CHANCES CURRENTLY LOOK MINIMAL FOR THE WEEKEND AS SURFACE HIGH
PRESSURE AND DRIER AIR BUILD IN BEHIND THE FRONT. WILL AIM FOR HIGHS
IN THE 60S FOR THE WEEKEND...WITH LATE WEEK/WEEKEND LOWS MAINLY IN
THE 40S ALTHOUGH A FEW UPPER 30S MAY CREEP INTO NORTHERN AREAS.
KB
FIRE WEATHER...
NO ELEVATED OR CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED THROUGH
THE NEXT WEEK. BREEZY NORTH WINDS WILL DEVELOP MONDAY BEHIND A COLD
FRONT BUT RELATIVE HUMIDITIES WILL REMAIN ABOVE 20 PERCENT.
KB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
05/15
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1124 PM CDT SUN SEP 30 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
259 PM CDT SUN SEP 30 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION POTENTIAL MONDAY
AFTERNOON/EVENING AND TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING NEAR THE U.S. WEST COAST...A SHORTWAVE TROUGH
DROPPING DOWN INTO SOUTH CENTRAL CANADA AND NORTH DAKOTA...UPPER
LOWS OVER THE SOUTHERN PLAINS AND NEW ENGLAND...AND RIDGING OVER THE
FORECAST AREA. OTHER THAN SOME CIRRUS STREAMING NORTHEAST ACROSS
IOWA AHEAD OF THE SOUTHERN PLAINS UPPER LOW...MOSTLY SUNNY SKIES
EXIST ACROSS MUCH OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER
VALLEY REGION. THIS IS DUE TO PLENTIFUL DRY AIR SEEN ON 12Z
SOUNDINGS FROM ABR...MPX AND GRB...WHERE DEWPOINT DEPRESSIONS OF 10C
OR MORE EXISTED THROUGHOUT MUCH OF THE TROPOSPHERE. AT THE
SURFACE...HIGH PRESSURE WAS SITUATED ACROSS THE GREAT LAKES WHILE A
COLD FRONT EXTENDED FROM THE MANITOBA/ONTARIO BORDER SOUTHWEST INTO
CENTRAL SOUTH DAKOTA. SHARP 850MB TEMPERATURE GRADIENT EXISTS
BETWEEN THESE TWO SURFACE FEATURES...NOTED BY 12Z SOUNDING DATA OF
15C AT INL AND MPX COMPARED TO 8C AT GRB. THIS HAS RESULTED IN A
SIMILAR SHARP GRADIENT IN CURRENT TEMPERATURES....FROM THE LOWER 80S
IN WESTERN MINNESOTA TO THE UPPER 60S IN EASTERN WISCONSIN.
TONIGHT AND MONDAY...SHORTWAVE TROUGH COMING INTO NORTH DAKOTA IS
PROGGED TO SPLIT APART INTO TWO BY THE 30.12Z GFS/UKMET/CANADIAN AND
ECMWF...WITH PART OF IT HEADING INTO NORTHWEST ONTARIO AND THE OTHER
DROPPING SOUTH INTO NEBRASKA BY LATE MONDAY. THIS SCENARIO CREATES
SOME ISSUES FOR PRECIPITATION TO OCCUR...SINCE THE UPPER LEVEL
FORCING GETS SPLIT AROUND THE FORECAST AREA. PLUS THE AIRMASS IS
QUITE DRY. ALL FOUR MODELS SUGGEST A DRY FORECAST. THE 30.00Z ECMWF
AND 30.12Z NAM ON THE OTHER HAND KEEP MOST OF THE TROUGH
TOGETHER....DROPPING IT INTO MN AND IA DURING THE AFTERNOON. AS
SUCH...STRONGER FORCING EXISTS AND A FRONTOGENETICAL BAND OF LIGHT
RAIN IS FORECAST TO MOVE INTO NORTHWEST SECTIONS OF THE FORECAST
AREA DURING THE AFTERNOON. HAVE FOLLOWED THE MAJORITY OF THE 30.12Z
GUIDANCE AND PULLED OUT PRECIPITATION CHANCES ENTIRELY. BOTH
SCENARIOS STILL HAVE THE COLD FRONT OVER THE EASTERN DAKOTAS SLIDE
INTO THE FORECAST AREA WITH SIMILAR TIMING...SLOWLY MOVING THROUGH
DURING THE COURSE OF THE DAY MONDAY. AS SUCH...THERE COULD BE SOME
SLIGHT COOLING IN SOUTHEAST MINNESOTA LATE IN THE DAY. OTHERWISE...
850MB TEMPS OF 10-12C AT 18Z MONDAY COMBINED WITH MID/HIGH CLOUD
COVER SHOULD SUPPORT HIGHS TOPPING OUT IN THE UPPER 60S TO LOW 70S.
ENOUGH HIGH CLOUDS AND A SOUTHERLY GRADIENT LOOKS TO BE IN PLACE
TONIGHT TO PRECLUDE ANY VALLEY FOG DEVELOPMENT. THEY SHOULD ALSO
RESULT IN WARMER LOWS...ESPECIALLY WEST OF THE MISSISSIPPI RIVER.
GOING PREVIOUS FORECAST LOWS LOOK REASONABLE...WITH THE TYPICAL
WISCONSIN COLD SPOTS DROPPING INTO THE UPPER 30S DUE TO A LONGER
PERIOD OF DECOUPLED WINDS.
MONDAY NIGHT AND TUESDAY...THE POSSIBLY SPLIT SHORTWAVE TROUGH LOOKS
TO MOVE THROUGH THE FORECAST AREA LATE MONDAY NIGHT...WITH RIDGING
BUILDING IN FROM THE WEST ON TUESDAY AS A POTENT UPPER TROUGH BEGINS
TO DROP SOUTH INTO MONTANA. AGAIN WHETHER OR NOT PRECIPITATION FALLS
MONDAY NIGHT DEPENDS ON HOW SPLIT APART THAT SHORTWAVE TROUGH IS...
WITH THE 30.00Z ECMWF DEPICTING A MUCH BETTER CHANCE OF RAIN
COMPARED TO THE 30.12Z NAM/GFS/UKMET/CANADIAN/ECMWF. CONTINUED TO
FOLLOW THE DRY MAJORITY AS WELL AS PREVIOUS DRY FORECAST.
STILL...AFTER 06Z TUESDAY...DRY WEATHER SHOULD BE THE RULE WITH
SKIES CLEARING OUT...ESPECIALLY OVER THE NORTHWESTERN 2/3 OF THE
AREA. TEMPERATURES SHOULD STILL REMAIN SEASONABLE MONDAY
NIGHT...DESPITE THE COLD FRONTAL PASSAGE...DUE TO A COMBINATION OF
THE CLOUDS AND 850MB TEMPS ONLY FALLING TO 6-8C BY 12Z TUESDAY.
GENERALLY FOLLOWED A BLEND OF GUIDANCE WHICH RESULTS IN LOWS IN THE
40S. WITH SUN BACK OUT FOR TUESDAY AND THE GIVEN 850MB TEMPS...HIGHS
REACHING UP INTO THE UPPER 60S TO LOW 70S SEEM REASONABLE.
TUESDAY NIGHT AND WEDNESDAY...THE POTENT UPPER TROUGHING DROPPING
INTO MONTANA ON TUESDAY IS PROGGED TO CONTINUE DIGGING SOUTHEAST...
INTO WYOMING AND PERHAPS THE DAKOTAS AS WELL BY 00Z THURSDAY. AS
THIS TROUGH DIGS...IT HELPS TO KICK OUT THE STALLED UPPER LOW IN THE
SOUTHERN PLAINS. MODEL TRENDS HAVE SHOWN A LOT OF RETROGRESSION THE
PAST COUPLE OF DAYS WITH THIS UPPER LOW...WHICH IS NOW SLATED TO
LIFT UP THROUGH LOWER MICHIGAN ON WEDNESDAY. A DEFORMATION
PRECIPITATION BAND ASSOCIATED WITH THIS UPPER LOW IS FORECAST BY THE
30.12Z NAM TO PERHAPS CLIP PORTIONS OF GRANT AND ADAMS COUNTIES ON
WEDNESDAY. THE NAM IS A WESTERN OUTLIER...WITH ALL OTHER MODELS
KEEPING THE BAND TRACKING NOT MUCH FARTHER WEST THAN THE CHICAGO
AREA. THEREFORE...HAVE DISCOUNTED THE NAM AT THIS TIME...AND WILL
FOLLOW THE MAJORITY SHOWING UPPER RIDGING HOLDING OVER THE FORECAST
AREA BETWEEN THE POTENT UPPER TROUGH AND UPPER LOW. SUBSIDENCE AND
DRY AIR UNDER THIS UPPER RIDGE IS EXPECTED TO RESULT IN DRY WEATHER
FOR THIS TUESDAY NIGHT AND WEDNESDAY PERIOD. DEPENDING ON CLOUD
COVER AND IF IT RAINS MONDAY NIGHT...COULD BE A CONCERN FOR VALLEY
FOG TUESDAY NIGHT...SINCE A SURFACE RIDGE OF HIGH PRESSURE SHOULD BE
IN PLACE. OTHERWISE...TEMPERATURES LOOK FAIRLY MILD FOR EARLY
OCTOBER WITH LOWS STILL IN THE 40S AND 850MB TEMPS OF 10-12C ON
WEDNESDAY BOOSTING HIGHS INTO THE LOW TO MID 70S.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
259 PM CDT SUN SEP 30 2012
IN THE MEAN...THE 30.12Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ALL
CONTINUE TO FORECAST A BIG CHANGE IN THE UPPER LEVEL PATTERN DURING
THE LONG TERM PERIOD. BY THE WEEKEND...THERE SHOULD BE DEEP UPPER
LEVEL TROUGHING IN PLACE ACROSS THE EASTERN TWO THIRDS OF CANADA AS
WELL AS THE NORTHERN PLAINS EASTWARD INTO THE GREAT LAKES. FALL WILL
REALLY BE FELT THIS WEEKEND AS 850MB TEMPS PLUMMET TO BELOW -2C.
PLENTY OF DIFFERENCES EXIST ON HOW WE GET TO THE WEEKEND...MOSTLY
RELATED TO THAT POTENT TROUGH THE DIGS INTO WYOMING ON WEDNESDAY.
THE 30.12Z ECMWF/CANADIAN/GFS ALL HAVE THE POTENT TROUGH TURNING
NEGATIVE TILT AS IT COMES ACROSS THE NORTHERN PLAINS INTO MINNESOTA
WEDNESDAY NIGHT AND THURSDAY. HOW FAR NORTHWEST THIS TURN TO
NEGATIVE TILT OCCURS AND TIMING IS AT ODDS AMONGST THE MODELS...WITH
THE 30.00Z ECMWF/30.12Z CANADIAN FARTHER TO THE NORTHWEST THAN THE
30.12Z GFS. THIS HAS MAJOR IMPLICATIONS ON HOW MUCH PRECIPITATION
AND COLD AIR TIMING. IN THE CASE OF THE 30.00Z ECMWF/30.12Z
CANADIAN...THEY ARE MUCH LIGHTER ON PRECIPITATION COMPARED TO THE
30.12Z GFS. NEW 30.12Z ECMWF IS COMPLETELY DRY. FOR NOW...WILL
FOLLOW A CONSENSUS APPROACH WITH 20 CHANCES WEDNESDAY NIGHT AND
30-50 ON THURSDAY. ALSO OF NOTE IS THE 30.12Z ECMWF/CANADIAN ARE
MUCH FASTER THAN THE GFS. MUCH COOLER DAY ANTICIPATED ON THURSDAY
TOO AS THE COLD FRONT PASSES...SENDING 850MB TEMPS DOWN TO 0-4C BY
00Z FRIDAY. BREEZY NORTHWEST WINDS LIKELY TOO BEHIND THE FRONT...
ESPECIALLY IF THE GFS PANS OUT. MAINLY DRY WEATHER SHOULD FOLLOW FOR
THURSDAY NIGHT. FOR FRIDAY AND SATURDAY...THE 30.00Z/30.12Z ECMWF
SHOW SOME FRONTOGENESIS-TYPE LIGHT RAIN OCCURRING ACROSS MUCH OF
THE FORECAST AREA...NORTH OF A STALLED BOUNDARY FROM KANSAS TO
INDIANA. THE 30.12Z GFS/CANADIAN HAVE THIS BOUNDARY MUCH FARTHER
SOUTH...RESULTING IN DRY CONDITIONS. GIVEN THE GENERALLY GOOD
PERFORMANCE OF THE ECMWF...NEED TO HAVE AT LEAST SOME 20 PERCENT
CHANCES FOR FRIDAY AND SATURDAY...ESPECIALLY SOUTH OF I-90. ALL
MODELS HAVE HIGH PRESSURE CROSSING THE AREA ON SUNDAY...THUS DRIER
WEATHER IS EXPECTED.
&&
.AVIATION...THROUGH 06Z TUESDAY
1124 PM CDT SUN SEP 30 2012
THE MAIN FOCUS AT THE TAF SITES WILL BE WITH THE TIMING OF WHEN A
COLD FRONT MOVES THROUGH MONDAY MORNING. HIGH LEVEL CLOUD COVER
WILL PERSIST OVERNIGHT AHEAD OF THE COLD FRONT WITH SOUTHERLY
WINDS GRADUALLY INCREASING BY DAY BREAK. THESE WINDS WILL QUICKLY
SHIFT AROUND TO THE NORTHWEST AND BECOME GUSTY TO 20KTS AS THE
COLD FRONT PASSES THROUGH RST AROUND 14Z AND LSE AROUND 18Z. MID
LEVEL CLOUD COVER WILL BE ON THE INCREASE BEHIND THE FRONT WITH
SOME SPRINKLES NOT OUT OF THE QUESTION. VISIBILITY AND CEILINGS
WILL REMAIN VFR THOUGH THROUGHOUT WITH THE WIND GUSTS RECEDING
MONDAY EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
259 PM CDT SUN SEP 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1025 AM EDT MON OCT 1 2012
.UPDATE...
AVIATION SECTION UPDATED
&&
.SYNOPSIS...
ISSUED AT 341 AM EDT MON OCT 1 2012
AN UPPER TROUGH SLOWLY LIFTING OUT OF THE MISSISSIPPI VALLEY WILL
KEEP CHANCES FOR RAIN IN THE FORECAST TODAY THROUGH WEDNESDAY.
WEDNESDAY NIGHT THIS FEATURE FINALLY LIFTS OUT OF THE AREA AND
ALLOWS THINGS TO DRY OUT. THURSDAY NIGHT A COLD FRONT WILL MOVE
THROUGH AND BRING CHANCES FOR SHOWERS AND THUNDERSTORMS AND USHER IN
COOLER TEMPERATURES. AFTER THAT UPPER PATTERN IS MORE PROGRESSIVE
AND COULD SEE SHORTWAVES MOVE THROUGH THE FLOW AND HAVE SLIGHT
CHANCES FOR PRECIPITATION DUE TO THIS.
&&
.NEAR TERM /TODAY/...
ISSUED AT 341 AM EDT MON OCT 1 2012
CURRENT PRECIP SHIELD NEAR THE KENTUCKY TENNESSEE BORDER IS MATCHING
UP NICELY WITH ISENTROPIC LIFT AT 300K IN THE NAM. GFS IS A BIT
FURTHER SOUTH WITH THE ISENTROPIC LIFT CURRENTLY...AND THUS IT
BRINGS IN THE PRECIPITATION SLOWER TODAY IF AT ALL. THIS SEEMS TO BE
RESULTING FROM A SLOWER NORTHWARD MOVEMENT OF THE SURFACE LOW IN THE
GFS. OTHER MODELS ARE QUICKER WITH THE NORTHWARD MOVEMENT OF THE LOW
AND NOT AS FAR EAST. WILL FOLLOW THE 300K ISENTROPIC LIFT IN THE NAM
FOR THE INTRODUCTION OF POPS INTO THE AREA...RESULTING IN A SLIGHTLY
SLOWER ARRIVAL THAN PREVIOUS FORECAST BUT HIGHER POPS BY AFTERNOON
SPREADING FURTHER NORTH. THIS ARRIVAL OF PRECIP IN THE SOUTH AROUND
18Z IS SIMILAR TO THAT SEEN IN THE 3Z HRRR AND THE 6Z RAP. GUIDANCE
TEMPERATURES WERE SIMILAR SO USED A MAV/MET AVERAGE. WILL CONTINUE
TO MONITOR TO SEE IF SHOWERS MOVE NORTH QUICKER THAN FORECAST BUT AT
THIS POINT LOOKS UNLIKELY BEFORE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 341 AM EDT MON OCT 1 2012
FORECAST FOCUS IS ON POPS THROUGH THE PERIOD. MODELS HAVE SOME
DISTINCT DISAGREEMENTS DESCRIBED BELOW. GFS TAKES THE SURFACE LOW
FURTHER SOUTH AND EAST THAN NAM/12Z ECMWF/UKMET OR SREFS UNTIL
TUESDAY AFTERNOON AND AS A RESULT IT/S QPF FIELDS BARELY BRING
PRECIPITATION INTO THE SOUTHERN COUNTIES AND PRODUCE NOTHING IN THE
NORTH OR WEST UNTIL TUESDAY NIGHT WHEN THE LOW SWINGS A BIT WEST.
LOOKING AT THE UPPER LEVEL Q VECTOR CONVERGENCE AS WELL AS LOW LEVEL
FRONTOGENESIS FIELDS EVEN IN THE GFS THE QPF DOESN/T SEEM TO MATCH
UP. THE UPPER LEVEL FORCING ARRIVES BY MIDDAY MONDAY ACROSS THE AREA
AND FRONTOGENESIS ARRIVES IN THE SOUTH BY 0Z AND LIFTS NORTH THROUGH
THE AREA FROM 0 TO 12Z TUESDAY. BOTH IMPLY QPF ACROSS MUCH OF THE
AREA. UKMET SOLUTION MATCHES UP FAIRLY WELL WITH NAM AND SREFS ARE
ALSO IN THIS CAMP. THEREFORE PREFER A NAM/SREF SOLUTION THROUGH
TUESDAY NIGHT.
ISENTROPIC LIFT AND GOOD JET DYNAMICS ESPECIALLY ACROSS THE EASTERN
COUNTIES WILL BE IN PLACE TONIGHT AND THIS SHOULD BE SUFFICIENT TO
JUSTIFY CATEGORICAL POPS IN THE EAST TAPERING TO HIGH CHANCE IN THE
NORTHWEST. A SMALL AMOUNT OF ELEVATED INSTABILITY WILL ALSO BE
ADVECTED IN ACROSS THE SOUTH AND EAST AND THUS INCLUDE A SLIGHT
CHANCE FOR THUNDER THERE AS WELL. TUESDAY SHOULD SEE THE ARRIVAL OF
MORE INSTABILITY. AGAIN THE UPPER LEVEL JET WILL BE PARKED OVER THE
AREA AND ISENTROPIC LIFT WILL CONTINUE AND WENT WITH LIKELY POPS
ACROSS ALL BUT THE NORTHWEST WITH A CHANCE FOR THUNDER ACROSS THE
SAME AREA AS THE LIKELY POPS. TUESDAY NIGHT AND WEDNESDAY THE UPPER
TROUGH CONTINUES OVER THE AREA WITH THE TROUGH AXIS MOVING THROUGH
ON WEDNESDAY AFTERNOON. THE SURFACE LOW LIFTS THROUGH THE AREA
DURING THIS TIME AS WELL. FORCING IS A BIT WEAKER DURING THIS TIME
BUT SUFFICIENT TO INCLUDE CHANCES FOR RAIN. AFTER THE TROUGH AXIS
GETS EAST OF THE AREA BY WEDNESDAY EVENING THERE WILL BE NOTHING
LEFT IN THE WAY OF FORCING AND WEDNESDAY NIGHT SHOULD BE DRY AS A
RESULT.
FOR TEMPERATURES LEANED COOLER THAN GUIDANCE FOR HIGHS WITH
SIGNIFICANT CLOUD COVER AND RAIN. FOR LOWS FAVORED WARMER GUIDANCE
FOR SAME REASON.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 341 AM EDT MON OCT 1 2012
MAIN CHALLENGE TO THE EXTENDED WILL BE ATTEMPTING TO RESOLVE MODEL
DIFFERENCES ESPECIALLY RELATED TO QPF.
MODELS ARE IN A BIT BETTER AGREEMENT TO START THE EXTENDED OFF AS
THE ALL KEYING IN ON A POTENT NEGATIVELY TILTED TROUGH THAT WILL BE
PIVOTING FROM THE UPPER MIDWEST INTO ONTARIO ON FRIDAY. FAST UPPER
FLOW AROUND THE BASE OF THE TROUGH WILL PUSH A COLD FRONT QUICKLY
THROUGH CENTRAL INDIANA THURSDAY NIGHT AND TO AROUND A CINCINNATI TO
MEMPHIS LINE BY 12Z FRIDAY. THE STRENGTH OF THIS SYSTEM ALONG WITH
SOME WEAK INSTABILITY PER THE MODELS SHOULD RESULT IN AT LEAST A FEW
SHOWERS AND ISOLATED THUNDERSTORMS SHORTLY AFTER 00Z FRIDAY.
SOUTHWEST FLOW AHEAD OF THE FRONT SHOULD RESULT IN SLIGHTLY ABOVE
NORMAL TEMPERATURES ON THURSDAY.
BY 00Z DAY...THE MODELS START TO HAVE BIG DIFFERENCES. MODELS ARE
ALL SHOWING A VERY LARGE AREA OF WEST CENTRAL CANADIAN HIGH PRESSURE
EXTENDING SOUTHEAST TO THE TENNESSEE VALLEY BEHIND THE DEPARTING
FRONT. HOWEVER...THE 12Z AND 00Z ECMWF RUNS ARE MUCH STRONGER AND
FURTHER NORTHEAST WITH A SOUTHWEST SYSTEM THAN ANY OTHER EXTENDED
MODEL PER COLLABORATION WITH THE HYDROMETEOROLOGICAL PREDICTION
CENTER. THIS RESULTS IN THE EURO MOVING A WAVE ACROSS THE OHIO
VALLEY ON SATURDAY AND RESULTANT OVERRUNNING AND A LARGE AREA OF QPF
ACROSS OUR FORECAST AREA. THE OTHER MODELS ARE WELL SOUTHWEST WITH
THE OVERRUNNING AND QPF. THAT SAID...KEPT SMALL POPS FROM THE
REGIONAL ENSEMBLE THROUGH SATURDAY NIGHT IN THE EVENT THE THE EURO
ENDS UP VERIFYING BETTER AND/OR ANY WAVE IN THE FAST ZONAL FLOW
ALOFT HAPPENS TO SQUEEZE OUT SOME LIGHT QPF. AT ANY RATE...ALL
MODELS AGREE ON THE CANADIAN HIGH PRESSURE CENTERED ACROSS CENTRAL
INDIANA ON SUNDAY WITH A DRY COLUMN. SO SHOULD NOT SEE ANY SHOWERS
THEN.
REGIONAL ENSEMBLES LOOK PRETTY REASONABLE WITH TEMPERATURES STARTING
OUT ABOVE NORMAL IN THE 70S ON THURSDAY AND GETTING PROGRESSIVELY
COLDER WITH AFTERNOON HIGHS WELL BELOW NORMAL AND ONLY IN THE 50S
BY SATURDAY. OVERNIGHT LOWS WILL BE IN THE 30S BY SATURDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR THE 15Z IND TAF UPDATE/...
RADAR TRENDS INDICATE SHRA OVER SOUTHERN INDIANA AND KENTUCKY
SLOWLY MAKING PROGRESS NORTHWARD. HOWEVER..DRY NORTHEAST WINDS
WITH DEW POINT TEMPS IN THE MID 40S WERE HELPING TO ERODE THE
APPROACHING PRECIP AND KEEP VFR CONDITIONS CONTINUING.
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH LATE THIS
AFTERNOON UNTIL THE ARRIVAL OF DEEPER MOISTURE ASSOCIATED WITH THE
APPROACHING LOW. ONGOING TAF HANDLES THIS WELL AND HAVE MADE ONLY
MINOR CHANGES BASED UPON OBSERVATIONAL TRENDS.
PREVIOUS DISCUSSION BELOW
/DISCUSSION FOR THE 011200Z TAF ISSUANCE/...
ISSUED AT 640 AM EDT MON OCT 1 2012
VFR CONDITIONS WILL BECOME MVFR AND THEN IFR LATE AS RAIN
OVERSPREADS THE TAF SITES FROM SOUTHWEST TO NORTHEAST. THE RAIN
SHIELD SHOULD BE NEAR BMG BY 20Z...IND AND HUF BY 23Z AND LAF BY 02Z
TUESDAY. LEFT WINDS WILL BE NORTHEAST AROUND 10 KNOTS THROUGH THE
TAF PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....KOCH
AVIATION...MK/JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
640 AM EDT MON OCT 1 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 341 AM EDT MON OCT 1 2012
AN UPPER TROUGH SLOWLY LIFTING OUT OF THE MISSISSIPPI VALLEY WILL
KEEP CHANCES FOR RAIN IN THE FORECAST TODAY THROUGH WEDNESDAY.
WEDNESDAY NIGHT THIS FEATURE FINALLY LIFTS OUT OF THE AREA AND
ALLOWS THINGS TO DRY OUT. THURSDAY NIGHT A COLD FRONT WILL MOVE
THROUGH AND BRING CHANCES FOR SHOWERS AND THUNDERSTORMS AND USHER IN
COOLER TEMPERATURES. AFTER THAT UPPER PATTERN IS MORE PROGRESSIVE
AND COULD SEE SHORTWAVES MOVE THROUGH THE FLOW AND HAVE SLIGHT
CHANCES FOR PRECIPITATION DUE TO THIS.
&&
.NEAR TERM /TODAY/...
ISSUED AT 341 AM EDT MON OCT 1 2012
CURRENT PRECIP SHIELD NEAR THE KENTUCKY TENNESSEE BORDER IS MATCHING
UP NICELY WITH ISENTROPIC LIFT AT 300K IN THE NAM. GFS IS A BIT
FURTHER SOUTH WITH THE ISENTROPIC LIFT CURRENTLY...AND THUS IT
BRINGS IN THE PRECIPITATION SLOWER TODAY IF AT ALL. THIS SEEMS TO BE
RESULTING FROM A SLOWER NORTHWARD MOVEMENT OF THE SURFACE LOW IN THE
GFS. OTHER MODELS ARE QUICKER WITH THE NORTHWARD MOVEMENT OF THE LOW
AND NOT AS FAR EAST. WILL FOLLOW THE 300K ISENTROPIC LIFT IN THE NAM
FOR THE INTRODUCTION OF POPS INTO THE AREA...RESULTING IN A SLIGHTLY
SLOWER ARRIVAL THAN PREVIOUS FORECAST BUT HIGHER POPS BY AFTERNOON
SPREADING FURTHER NORTH. THIS ARRIVAL OF PRECIP IN THE SOUTH AROUND
18Z IS SIMILAR TO THAT SEEN IN THE 3Z HRRR AND THE 6Z RAP. GUIDANCE
TEMPERATURES WERE SIMILAR SO USED A MAV/MET AVERAGE. WILL CONTINUE
TO MONITOR TO SEE IF SHOWERS MOVE NORTH QUICKER THAN FORECAST BUT AT
THIS POINT LOOKS UNLIKELY BEFORE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 341 AM EDT MON OCT 1 2012
FORECAST FOCUS IS ON POPS THROUGH THE PERIOD. MODELS HAVE SOME
DISTINCT DISAGREEMENTS DESCRIBED BELOW. GFS TAKES THE SURFACE LOW
FURTHER SOUTH AND EAST THAN NAM/12Z ECMWF/UKMET OR SREFS UNTIL
TUESDAY AFTERNOON AND AS A RESULT IT/S QPF FIELDS BARELY BRING
PRECIPITATION INTO THE SOUTHERN COUNTIES AND PRODUCE NOTHING IN THE
NORTH OR WEST UNTIL TUESDAY NIGHT WHEN THE LOW SWINGS A BIT WEST.
LOOKING AT THE UPPER LEVEL Q VECTOR CONVERGENCE AS WELL AS LOW LEVEL
FRONTOGENESIS FIELDS EVEN IN THE GFS THE QPF DOESN/T SEEM TO MATCH
UP. THE UPPER LEVEL FORCING ARRIVES BY MIDDAY MONDAY ACROSS THE AREA
AND FRONTOGENESIS ARRIVES IN THE SOUTH BY 0Z AND LIFTS NORTH THROUGH
THE AREA FROM 0 TO 12Z TUESDAY. BOTH IMPLY QPF ACROSS MUCH OF THE
AREA. UKMET SOLUTION MATCHES UP FAIRLY WELL WITH NAM AND SREFS ARE
ALSO IN THIS CAMP. THEREFORE PREFER A NAM/SREF SOLUTION THROUGH
TUESDAY NIGHT.
ISENTROPIC LIFT AND GOOD JET DYNAMICS ESPECIALLY ACROSS THE EASTERN
COUNTIES WILL BE IN PLACE TONIGHT AND THIS SHOULD BE SUFFICIENT TO
JUSTIFY CATEGORICAL POPS IN THE EAST TAPERING TO HIGH CHANCE IN THE
NORTHWEST. A SMALL AMOUNT OF ELEVATED INSTABILITY WILL ALSO BE
ADVECTED IN ACROSS THE SOUTH AND EAST AND THUS INCLUDE A SLIGHT
CHANCE FOR THUNDER THERE AS WELL. TUESDAY SHOULD SEE THE ARRIVAL OF
MORE INSTABILITY. AGAIN THE UPPER LEVEL JET WILL BE PARKED OVER THE
AREA AND ISENTROPIC LIFT WILL CONTINUE AND WENT WITH LIKELY POPS
ACROSS ALL BUT THE NORTHWEST WITH A CHANCE FOR THUNDER ACROSS THE
SAME AREA AS THE LIKELY POPS. TUESDAY NIGHT AND WEDNESDAY THE UPPER
TROUGH CONTINUES OVER THE AREA WITH THE TROUGH AXIS MOVING THROUGH
ON WEDNESDAY AFTERNOON. THE SURFACE LOW LIFTS THROUGH THE AREA
DURING THIS TIME AS WELL. FORCING IS A BIT WEAKER DURING THIS TIME
BUT SUFFICIENT TO INCLUDE CHANCES FOR RAIN. AFTER THE TROUGH AXIS
GETS EAST OF THE AREA BY WEDNESDAY EVENING THERE WILL BE NOTHING
LEFT IN THE WAY OF FORCING AND WEDNESDAY NIGHT SHOULD BE DRY AS A
RESULT.
FOR TEMPERATURES LEANED COOLER THAN GUIDANCE FOR HIGHS WITH
SIGNIFICANT CLOUD COVER AND RAIN. FOR LOWS FAVORED WARMER GUIDANCE
FOR SAME REASON.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 341 AM EDT MON OCT 1 2012
MAIN CHALLENGE TO THE EXTENDED WILL BE ATTEMPTING TO RESOLVE MODEL
DIFFERENCES ESPECIALLY RELATED TO QPF.
MODELS ARE IN A BIT BETTER AGREEMENT TO START THE EXTENDED OFF AS
THE ALL KEYING IN ON A POTENT NEGATIVELY TILTED TROUGH THAT WILL BE
PIVOTING FROM THE UPPER MIDWEST INTO ONTARIO ON FRIDAY. FAST UPPER
FLOW AROUND THE BASE OF THE TROUGH WILL PUSH A COLD FRONT QUICKLY
THROUGH CENTRAL INDIANA THURSDAY NIGHT AND TO AROUND A CINCINNATI TO
MEMPHIS LINE BY 12Z FRIDAY. THE STRENGTH OF THIS SYSTEM ALONG WITH
SOME WEAK INSTABILITY PER THE MODELS SHOULD RESULT IN AT LEAST A FEW
SHOWERS AND ISOLATED THUNDERSTORMS SHORTLY AFTER 00Z FRIDAY.
SOUTHWEST FLOW AHEAD OF THE FRONT SHOULD RESULT IN SLIGHTLY ABOVE
NORMAL TEMPERATURES ON THURSDAY.
BY 00Z DAY...THE MODELS START TO HAVE BIG DIFFERENCES. MODELS ARE
ALL SHOWING A VERY LARGE AREA OF WEST CENTRAL CANADIAN HIGH PRESSURE
EXTENDING SOUTHEAST TO THE TENNESSEE VALLEY BEHIND THE DEPARTING
FRONT. HOWEVER...THE 12Z AND 00Z ECMWF RUNS ARE MUCH STRONGER AND
FURTHER NORTHEAST WITH A SOUTHWEST SYSTEM THAN ANY OTHER EXTENDED
MODEL PER COLLABORATION WITH THE HYDROMETEOROLOGICAL PREDICTION
CENTER. THIS RESULTS IN THE EURO MOVING A WAVE ACROSS THE OHIO
VALLEY ON SATURDAY AND RESULTANT OVERRUNNING AND A LARGE AREA OF QPF
ACROSS OUR FORECAST AREA. THE OTHER MODELS ARE WELL SOUTHWEST WITH
THE OVERRUNNING AND QPF. THAT SAID...KEPT SMALL POPS FROM THE
REGIONAL ENSEMBLE THROUGH SATURDAY NIGHT IN THE EVENT THE THE EURO
ENDS UP VERIFYING BETTER AND/OR ANY WAVE IN THE FAST ZONAL FLOW
ALOFT HAPPENS TO SQUEEZE OUT SOME LIGHT QPF. AT ANY RATE...ALL
MODELS AGREE ON THE CANADIAN HIGH PRESSURE CENTERED ACROSS CENTRAL
INDIANA ON SUNDAY WITH A DRY COLUMN. SO SHOULD NOT SEE ANY SHOWERS
THEN.
REGIONAL ENSEMBLES LOOK PRETTY REASONABLE WITH TEMPERATURES STARTING
OUT ABOVE NORMAL IN THE 70S ON THURSDAY AND GETTING PROGRESSIVELY
COLDER WITH AFTERNOON HIGHS WELL BELOW NORMAL AND ONLY IN THE 50S
BY SATURDAY. OVERNIGHT LOWS WILL BE IN THE 30S BY SATURDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...
ISSUED AT 640 AM EDT MON OCT 1 2012
VFR CONDITIONS WILL BECOME MVFR AND THEN IFR LATE AS RAIN
OVERSPREADS THE TAF SITES FROM SOUTHWEST TO NORTHEAST. THE RAIN
SHIELD SHOULD BE NEAR BMG BY 20Z...IND AND HUF BY 23Z AND LAF BY 02Z
TUESDAY. LEFT WINDS WILL BE NORTHEAST AROUND 10 KNOTS THROUGH THE
TAF PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....KOCH
AVIATION...MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
910 AM MDT MON OCT 1 2012
.UPDATE...
ISSUED AT 902 AM MDT MON OCT 1 2012
MAIN CHANGE WAS TO INCREASE THE WINDS FOR THE DAY OVER THE EAST
HALF OF THE AREA. LATEST VAD WINDS FROM THE RADAR SHOW WINDS OF
30KTS ABOVE THE SURFACE. LATEST NAM MIXED LAYER WINDS HAVE
STRENGTHENED TO MATCH THE MOS OUTPUT...SUGGESTING GUSTS MAY REACH
40 MPH EAST OF A STRATTON NEBRASKA TO RUSSELL SPRINGS LINE DURING
THE EARLY AFTERNOON. AFTER THAT THE STRONGER WINDS MOVE SOUTH.
DID HOLD ONTO THE SLIGHT CHANCES OVER THE EAST HALF DURING THE
MORNING SINCE THE LEFT EXIT OF THE 300MB JET WILL BE OVER THE
AREA. IF ANY STORMS DO DEVELOP THEY WILL BE WIDELY SCATTERED AT
BEST AND MOVE OUT BY THE EARLY AFTERNOON AS THE LEFT EXIT OF THE
JET MOVES SOUTHEAST.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 216 AM MDT MON OCT 1 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW LONGWAVE TROUGH
EXTENDING SOUTH ACROSS THE EASTERN CONUS...WITH TWO CLOSED LOW
CENTERS OVER NEW ENGLAND AND ANOTHER OVER THE SOUTHERN MISSISSIPPI
VALLEY. A LARGE SCALE RIDGE EXTENDS NORTH ACROSS THE WESTERN
CONUS...WITH NORTH TO NORTHWEST FLOW OVER THE PLAINS. AT THE
SURFACE A COLD FRONT HAS DROPPED SOUTH ACROSS THE NORTHEAST PART
OF THE CWA.
ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ALONG THIS FRONT
NEAR AN AXIS OF H85 FRONTOGENESIS IN THE NORTHWEST. THIS ACTIVITY
SHOULD CONTINUE TO SPREAD SOUTHEAST ACROSS THE REST OF THE FORECAST
AREA THROUGH THE EARLY MORNING HOURS. THE FRONT SHOULD BE SOUTH OF
THE CWA BY THE AFTERNOON...WITH SUBSIDENCE BUILDING IN FROM THE
WEST. I LEFT LINGERING POPS IN PLACE ACROSS THE EAST THROUGH THE IN
PROXIMITY TO FRONT WHERE GUIDANCE CONTINUES TO INDICATE LIGHT QPF.
PRECIP AMOUNTS SHOULD BE LOW WITH A FEW HUNDREDTHS OF AN INCH AT THE
MOST.
OVERALL TREND SHOULD BE CLEARING BY THIS EVENING WITH SUBSIDENCE
OVERSPREADING THE AREA FROM THE WEST. HIGH TEMPERATURES TODAY WILL
BE ABOUT 10 TO 15F COOLER THAN SUNDAY WITH HIGHS IN THE 60S/70S
ACROSS THE CWA. THE AIR MASS TONIGHT LOOKS VERY SIMILAR TO OUR LAST
FEW COOL-DOWNS...SO I USED THAT AS A BASIS FOR MY LOW TEMPERATURE
FORECAST. WITH CLEAR SKIES AND CALM WINDS EXPECTED TEMPERATURES
SHOULD DROP INTO THE LOW 40S ACROSS MUCH OF THE AREA...WITH
TRADITIONAL COLD SPOTS IN THE MID TO UPPER 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 336 AM MDT MON OCT 1 2012
SHORTWAVE RIDGING BUILDS OVER THE TRI-STATE AREA TUESDAY AND
WEDNESDAY...WITH DRY CONDITIONS EXPECTED. A WARM FRONT WILL MOVE
ACROSS THE REGION TUESDAY WITH TEMPERATURE WARMING BACK INTO THE
UPPER 70S/LOW 80S. A COLD FRONT WILL DROP SOUTH INTO THE REGION LATE
WEDNESDAY OR WEDNESDAY NIGHT. OVERALL TREND HAS BEEN TO SPEED UP
THIS FRONTAL PASSAGE. WITH THE AMOUNT OF SPREAD BETWEEN MODELS ON
THIS FEATURE...CONFIDENCE IS LOW ON TEMPERATURE FORECAST WED. LARGE
SCALE ASCENT BUILDS OVER THE REGION WEDNESDAY NIGHT BEHIND THIS
FRONT AS ITS PARENT TROUGH MOVES ACROSS NORTHERN PLAINS. BEST
MOISTURE ADVECTION/LIFT SHOULD BE ACROSS THE NORTH...SO I KEPT
CHANCE POPS MAINLY NORTH OF I-70.
A DEFINITE CHANGE TO THE WEATHER BY LATE IN THE WEEK AS MUCH COLDER
TEMPERATURES ARE USHERED IN BEHIND A STRONG COLD FRONT THAT WILL MOVE
ACROSS THE PLAINS WEDNESDAY AFTERNOON. A SURFACE HIGH WILL BEGIN TO
BUILD INTO THE CENTRAL PLAINS ON THURSDAY BEHIND THE COLD FRONT AS
THE UPPER LEVEL LOW MOVES INTO THE GREAT LAKES REGION. FORECAST GETS
A LITTLE COMPLICATED LATE FRIDAY AND INTO THE WEEKEND. BROAD TROUGH
WITH CLOSED LOW OVER THE GREAT LAKES WILL SWING ANOTHER SHORTWAVE
TROUGH THROUGH THE NORTHERN PLAINS. MODELS ARE IN AGREEMENT WITH
THIS SHORTWAVE TROUGH...BUT DISAGREE ON THE MAGNITUDE AND SPEED OF
THE SYSTEM. ANOTHER CLOSED LOW WILL BE DEEPENING OFF THE COAST OF
CALIFORNIA AND WILL SLOWLY BEGIN TO MOVE ONSHORE BY EARLY NEXT WEEK.
THIS WILL KEEP THE REGION UNDER NEAR ZONAL TO NORTHWEST FLOW ALOFT.
NEAR THE SURFACE...A REINFORCING SHOT OF COLDER AIR WILL SLIDE DOWN
FROM CANADA AND INTO THE CENTRAL PLAINS BY THE WEEKEND. THIS NEXT
SHOT OF COLD AIR WILL ONLY ALLOW HIGHS TO CLIMB INTO THE 40S AND
MAYBE LOW 50S ON SATURDAY. THIS WILL ALSO BE OUR BEST CHANCE TO HAVE
OUR FIRST HARD FREEZE THIS SEASON AS MODELS AGREE THAT TEMPERATURES
WILL DROP INTO THE LOW TO MID 30S BOTH SAT AND SUN MORNINGS.
AS FOR PRECIPITATION CHANCES...MODELS ARE IN AGREEMENT THAT A COLD
WET WEEKEND IS A HIGH PROBABILITY. BEST POSSIBILITY LOOKS TO BE
FRIDAY NIGHT THROUGH SATURDAY AS THE SHORTWAVE TROUGH BEGINS TO MOVE
ACROSS THE NORTHERN PLAINS AND THE NEXT COLD SURGE SLIDES SOUTHWARD.
THE COLDER MODEL SOLUTIONS HAVE HINTED THAT A CHANCE FOR A RAIN/SNOW
MIX MAY BE POSSIBLE IN SOME PARTS OF THE TRI STATE REGION. GIVEN
THAT THIS IS PRETTY LATE IN THE EXTENDED PERIOD...WILL WAIT AND SEE
IF THIS TREND CONTINUES. FOR NOW...HAVE JUST KEPT RAIN SHOWERS IN
THE FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 500 AM MDT MON OCT 1 2012
VFR CONDITIONS ARE EXPECTED AT BOTH KGLD AND KMCK THROUGH THE
TAF PERIOD. LOW LEVEL WIND SHEAR BETWEEN 35-40KT WILL CONTINUE
THROUGH THE EARLY PART OF THE TAF PERIOD WITH LLJ IN PLACE AND
WINDS AT THE SURFACE GENERALLY AROUND 10KT. WINDS WILL INCREASE AT
BOTH TERMINALS AFTER SUNRISE WITH GUSTS 28-30KT EXPECTED. THESE
WINDS WILL DIMINISH AROUND 00Z AS THE PRESSURE GRADIENT
WEAKENS...AND DAYTIME MIXING COMES TO AN END. A FEW SHOWERS WILL
BE POSSIBLE THIS MORNING AS FRONT CONTINUES TO MOVE ACROSS THE
AREA...MAINLY AT KMCK WHERE VCSH IS INCLUDED THROUGH 14Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...PMM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
501 AM MDT MON OCT 1 2012
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 216 AM MDT MON OCT 1 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW LONGWAVE TROUGH
EXTENDING SOUTH ACROSS THE EASTERN CONUS...WITH TWO CLOSED LOW
CENTERS OVER NEW ENGLAND AND ANOTHER OVER THE SOUTHERN MISSISSIPPI
VALLEY. A LARGE SCALE RIDGE EXTENDS NORTH ACROSS THE WESTERN
CONUS...WITH NORTH TO NORTHWEST FLOW OVER THE PLAINS. AT THE
SURFACE A COLD FRONT HAS DROPPED SOUTH ACROSS THE NORTHEAST PART
OF THE CWA.
ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ALONG THIS FRONT
NEAR AN AXIS OF H85 FRONTOGENESIS IN THE NORTHWEST. THIS ACTIVITY
SHOULD CONTINUE TO SPREAD SOUTHEAST ACROSS THE REST OF THE FORECAST
AREA THROUGH THE EARLY MORNING HOURS. THE FRONT SHOULD BE SOUTH OF
THE CWA BY THE AFTERNOON...WITH SUBSIDENCE BUILDING IN FROM THE
WEST. I LEFT LINGERING POPS IN PLACE ACROSS THE EAST THROUGH THE IN
PROXIMITY TO FRONT WHERE GUIDANCE CONTINUES TO INDICATE LIGHT QPF.
PRECIP AMOUNTS SHOULD BE LOW WITH A FEW HUNDREDTHS OF AN INCH AT THE
MOST.
OVERALL TREND SHOULD BE CLEARING BY THIS EVENING WITH SUBSIDENCE
OVERSPREADING THE AREA FROM THE WEST. HIGH TEMPERATURES TODAY WILL
BE ABOUT 10 TO 15F COOLER THAN SUNDAY WITH HIGHS IN THE 60S/70S
ACROSS THE CWA. THE AIRMASS TONIGHT LOOKS VERY SIMILAR TO OUR LAST
FEW COOL-DOWNS...SO I USED THAT AS A BASIS FOR MY LOW TEMPERATURE
FORECAST. WITH CLEAR SKIES AND CALM WINDS EXPECTED TEMPERATURES
SHOULD DROP INTO THE LOW 40S ACROSS MUCH OF THE AREA...WITH
TRADITIONAL COLD SPOTS IN THE MID TO UPPER 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 336 AM MDT MON OCT 1 2012
SHORTWAVE RIDGING BUILDS OVER THE TRI-STATE AREA TUESDAY AND
WEDNESDAY...WITH DRY CONDITIONS EXPECTED. A WARM FRONT WILL MOVE
ACROSS THE REGION TUESDAY WITH TEMPERATURE WARMING BACK INTO THE
UPPER 70S/LOW 80S. A COLD FRONT WILL DROP SOUTH INTO THE REGION LATE
WEDNESDAY OR WEDNESDAY NIGHT. OVERALL TREND HAS BEEN TO SPEED UP
THIS FRONTAL PASSAGE. WITH THE AMOUNT OF SPREAD BETWEEN MODELS ON
THIS FEATURE...CONFIDENCE IS LOW ON TEMPERATURE FORECAST WED. LARGE
SCALE ASCENT BUILDS OVER THE REGION WEDNESDAY NIGHT BEHIND THIS
FRONT AS ITS PARENT TROUGH MOVES ACROSS NORTHERN PLAINS. BEST
MOISTURE ADVECTION/LIFT SHOULD BE ACROSS THE NORTH...SO I KEPT
CHANCE POPS MAINLY NORTH OF I-70.
A DEFINITE CHANGE TO THE WEATHER BY LATE IN THE WEEK AS MUCH COLDER
TEMPERATURES ARE USHERED IN BEHIND A STRONG COLD FRONT THAT WILL MOVE
ACROSS THE PLAINS WEDNESDAY AFTERNOON. A SURFACE HIGH WILL BEGIN TO
BUILD INTO THE CENTRAL PLAINS ON THURSDAY BEHIND THE COLD FRONT AS
THE UPPER LEVEL LOW MOVES INTO THE GREAT LAKES REGION. FORECAST GETS
A LITTLE COMPLICATED LATE FRIDAY AND INTO THE WEEKEND. BROAD TROUGH
WITH CLOSED LOW OVER THE GREAT LAKES WILL SWING ANOTHER SHORTWAVE
TROUGH THROUGH THE NORTHERN PLAINS. MODELS ARE IN AGREEMENT WITH
THIS SHORTWAVE TROUGH...BUT DISAGREE ON THE MAGNITUDE AND SPEED OF
THE SYSTEM. ANOTHER CLOSED LOW WILL BE DEEPENING OFF THE COAST OF
CALIFORNIA AND WILL SLOWLY BEGIN TO MOVE ONSHORE BY EARLY NEXT WEEK.
THIS WILL KEEP THE REGION UNDER NEAR ZONAL TO NORTHWEST FLOW ALOFT.
NEAR THE SURFACE...A REINFORCING SHOT OF COLDER AIR WILL SLIDE DOWN
FROM CANADA AND INTO THE CENTRAL PLAINS BY THE WEEKEND. THIS NEXT
SHOT OF COLD AIR WILL ONLY ALLOW HIGHS TO CLIMB INTO THE 40S AND
MAYBE LOW 50S ON SATURDAY. THIS WILL ALSO BE OUR BEST CHANCE TO HAVE
OUR FIRST HARD FREEZE THIS SEASON AS MODELS AGREE THAT TEMPERATURES
WILL DROP INTO THE LOW TO MID 30S BOTH SAT AND SUN MORNINGS.
AS FOR PRECIPITATION CHANCES...MODELS ARE IN AGREEMENT THAT A COLD
WET WEEKEND IS A HIGH PROBABILITY. BEST POSSIBILITY LOOKS TO BE
FRIDAY NIGHT THROUGH SATURDAY AS THE SHORTWAVE TROUGH BEGINS TO MOVE
ACROSS THE NORTHERN PLAINS AND THE NEXT COLD SURGE SLIDES SOUTHWARD.
THE COLDER MODEL SOLUTIONS HAVE HINTED THAT A CHANCE FOR A RAIN/SNOW
MIX MAY BE POSSIBLE IN SOME PARTS OF THE TRI STATE REGION. GIVEN
THAT THIS IS PRETTY LATE IN THE EXTENDED PERIOD...WILL WAIT AND SEE
IF THIS TREND CONTINUES. FOR NOW...HAVE JUST KEPT RAIN SHOWERS IN
THE FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 500 AM MDT MON OCT 1 2012
VFR CONDITIONS ARE EXPECTED AT BOTH KGLD AND KMCK THROUGH THE
TAF PERIOD. LOW LEVEL WIND SHEAR BETWEEN 35-40KT WILL CONTINUE
THROUGH THE EARLY PART OF THE TAF PERIOD WITH LLJ IN PLACE AND
WINDS AT THE SURFACE GENERALLY AROUND 10KT. WINDS WILL INCREASE AT
BOTH TERMINALS AFTER SUNRISE WITH GUSTS 28-30KT EXPECTED. THESE
WINDS WILL DIMINISH AROUND 00Z AS THE PRESSURE GRADIENT
WEAKENS...AND DAYTIME MIXING COMES TO AN END. A FEW SHOWERS WILL
BE POSSIBLE THIS MORNING AS FRONT CONTINUES TO MOVE ACROSS THE
AREA...MAINLY AT KMCK WHERE VCSH IS INCLUDED THROUGH 14Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...PMM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
757 AM EDT MON OCT 1 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EDT MON OCT 1 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE WRN GREAT LAKES TO JAMES BAY BETWEEN A LOW OVER NRN NEW ENGLAND
AND A TROUGH FROM MANITOBA INTO NORTH DAKOTA. AT THE SFC...A COLD
FRONT EXTENDED FROM NEAR PICKLE LAKE ONTARIO INTO ERN MN. RADAR
SHOWED SOME WEAK REFLECTIVITIES N CNTRL MN ALIGNED WITH WEAK TO
MODERATE MID LEVEL EVEN THOUGH SFC OBS INDICATED LITTLE MORE THAN
SOME MID CLOUDS. OTHERWISE...HIGH CLOUDS SPREADING ACROSS UPPER MI
AND WEAK SW WINDS HAVE KEPT TEMPS FROM FALLING OFF AS MUCH WITH
READINGS IN THE UPPER 30S AND LOWER 40S INLAND AND NEAR 50 ALONG
LAKE SUPERIOR.
AS THE MANITOBA MID LEVEL TROUGH PROGRESSES TO THE EAST TODAY AND
TONIGHT...THE COLD FRONT WILL ALSO SPREAD ACROSS UPPER MI. SINCE
THERE IS LITTLE MOISTURE INFLOW INTO THE RELATIVELY DRY AIR MASS AND
THE STRONGER 850-500 MB QVECTOR CONV REMAINS NORTH OF LAKE
SUPERIOR...RAIN CHANCES WILL BE MINIMAL. HOWEVER...WITH THE BAND OF
850-600 MB FGEN MOVING INTO THE WEST THIS EVENING...SOME ISOLATED
LIGHT SHOWERS OR SPRINKLES MAY BE POSSIBLE. POTENTIAL FOR ANY LAKE
ENHANCED PCPN WITH NRLY FLOW BEHIND THE FRONT ALSO WILL BE MINIMAL
WITH 850 MB TEMPS ONLY DROPPING TO AROUND 5C (LAKE SFC TEMPS WERE IN
THE 11C TO 14C RANGE).
EVEN WITH INCREASING MID/HIGH CLOUDS...WAA WILL HELP PUSH TEMPS INTO
THE MID AND UPPER 60S. CLOUDS WITH LINGERING 925-850 MB MOISTURE
OVER THE AREA WILL HOLD MIN READINGS IN THE 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 518 AM EDT MON OCT 1 2012
MAIN CONCERN PAST 12Z TUE IS WITH A DEEP UPPER TROUGH MOVING INTO
THE AREA THU...AND STAYING THROUGH THE WEEKEND.
FIRST FOR WED INTO EARLY WED NIGHT...AN UPPER TROUGH OVER THE LOWER
MISSISSIPPI VALLEY WILL SHEAR OFF AND MOVE SE OF THE CWA...WHICH MAY
PRODUCE SOME RAIN OVER THE FAR ERN CWA. PREVIOUS FORECAST WITH
CHANCE POPS OVER THE FAR E LOOKS GOOD SO WILL LEAVE THAT MOSTLY
UNCHANGED.
THEN FOR THE MAIN EVENT THU THROUGH SUN. MAIN IDEA FROM THE MODELS
IS THAT AS THE UPPER TROUGH MOVES INTO THE REGION...THE SRN END OF
THE TROUGH WILL BECOME NEGATIVELY TILTED RESULTING IN THE TROUGH
DEEPENING AND CLOSING OFF SOMEWHERE OVER OR NEAR THE CWA.
COMPLICATING MATTERS...ENERGY FROM THE TROUGH WILL SPLIT BETWEEN THE
SRN END AND THE MORE NRN END (OVER FAR NRN ONTARIO)...AND IT IS
DIFFICULT TO DETERMINE HOW MUCH OF THE ENERGY WILL GO TO THE SRN VS.
NRN END. THIS SEEMS TO BE ONE REASON WHY MODELS HAVE POOR RUN TO RUN
CONTINUITY AND POOR AGREEMENT WITH HOW TO HANDLE THIS SYSTEM. LATEST
RUN OF THE GFS (00Z/01) IS MORE LIKE THE LAST COUPLE RUNS OF THE
ECMWF...BRINGING A MODERATELY DEEPENING SFC LOW FROM WRN LAKE
SUPERIOR AROUND 12Z THU TO JAMES BAY BY 18Z FRI. THERE ARE STILL
SIGNIFICANT DIFFERENCES BETWEEN THE GFS AND ECMWF...BUT THE LATEST
RUN AGREES MORE WITH THE ECMWF THAN THE LAST RUN WITH SHOWING THE
LOW RAPIDLY DEEPENING AS IT MOVED THROUGH THE CENTER OF THE CWA. THE
GEM HAS THE SAME GENERAL IDEA BUT FARTHER N OVER ONTARIO. THE IDEA
OF A DEEPENING SYSTEM MOVING UP THE WRN SIDE OF LAKE SUPERIOR SEEMS
LIKE A REASONABLE AND FAMILIAR SCENARIO...BUT THE TRACK OF THIS
SYSTEM WILL BE VERY TRICKY TO FORECAST. EVEN IF MODEL AGREEMENT WAS
GREAT WITH THIS SYSTEM...THE FACT THAT THE TRACK OF THIS TYPE OF
SYSTEM IS HARD TO FORECAST THIS FAR OUT COMBINED WITH THE FACT THAT
THE SYSTEM HAS NOT MOVED INTO THE N AMERICAN PROFILING NETWORK YET
WOULD STILL LEAVE LITTLE CONFIDENCE IN THE FORECAST FOR THU/FRI. FOR
THIS REASON...AT THIS TIME IT IS NEARLY FUTILE TO MAKE LARGE
ADJUSTMENTS TO THE FORECAST FOR THU/FRI BASED ONLY ON THE LAST RUN
OF THE MODELS...ESPECIALLY GIVEN THE RUN TO RUN DISCONTINUITY FROM
THE MODELS AND THE FACT THAT THE TRACK OF THIS SYSTEM WILL HAVE HUGE
BEARING ON THE FORECAST.
THERE ARE SOME THINGS WE CAN LOOK AT THAT ARE MORE CERTAIN WITH THIS
SYSTEM...LIKE THE COLD AIR AND NW LOW LEVEL WINDS BEHIND THE SYSTEM.
850MB TEMPS FALL BELOW 0C BY LATE THU...AND GET PROGRESSIVELY COLDER
THROUGH FRI NIGHT (ALTHOUGH THE GFS WITH 850MB TEMPS OF -7C TO -9C
AT 12Z SAT IS 3-4C COLDER THAN THE ECMWF). THIS WILL LEAD TO LAKE
ENHANCE/EFFECT RAIN/SNOW IN NW WIND SNOWBELTS BEHIND THE SYSTEM INTO
SUN...WITH DECREASING LOW LEVEL MOISTURE LATE SAT INTO SUN MAKING
FOR MORE SCATTERED COVERAGE. THERE IS POTENTIAL FOR THE FIRST
ACCUMULATING SNOWFALL...ESPECIALLY OVER THE HIGHER TERRAIN OF WRN
UPPER MI WHERE LOW LEVEL TEMPS WILL BE COOLER. ANOTHER MORE CERTAIN
ASPECT WITH THE SYSTEM IS WLY GALES BEHIND THE LOW...ESPECIALLY IF
THE SFC LOW STICKS TO THE LAKE LONGER THAN MODELS SHOW AS IS COMMON
THIS TIME OF YEAR. WITH THE LOW DEEPENING AS IT MOVES OVER OR NEARBY
AND GOOD PRESSURE GRADIENT AND COLD AIR BEHIND THE SYSTEM...GALES
SHOULD BE ON THE STRONG SIDE AND WIND ADVISORIES/WARNINGS MAY BE
NEEDED ON LAND AS WELL...PARTICULARLY OVER THE KEWEENAW PENINSULA
AND ERN UPPER MI NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 751 AM EDT MON OCT 1 2012
ANY LINGERING SHALLOW FOG AT KSAW WILL DISSIPATE BY 13Z. OTHERWISE...
A COLD FNT WL CROSS UPR MI TODAY...BUT THE AIRMASS IS TOO DRY TO
SUPPORT MUCH IN THE WAY OF SHRA OR EVEN LO CLDS. THE BEST CHC OF
SHRA WL BE AFTER THE COLD FROPA...WHEN SOME LOWER CLDS MIGHT ARRIVE
AT IWD/CMX TOWARD LATE AFTN WITH AN UPSLOPE NW FLOW AND THEN AT SAW
LATER IN THE EVNG. ALTHOUGH THERE IS THE POTENTIAL FOR MVFR
CONDITIONS THAT MIGHT IMPACT THESE SITES...THE MOST FAVORABLE
UPSLOPE AND MOISTENING IS LIKELY AT KSAW WHERE IFR CIGS ARE MORE
LIKELY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT MON OCT 1 2012
A COLD FRONT WILL MOVE THROUGH LAKE SUPERIOR TODAY INTO TONIGHT. A
PERIOD OF MODERATE NRLY WINDS TO 25 KNOTS OVER CNTRL AND ERN LAKE
SUPERIOR IS EXPECTED JUST BEHIND THE FRONT LATE THIS EVENING AND
OVERNIGHT. OTHERWISE...WINDS WILL STAY BELOW 20 KNOTS INTO THURSDAY
BEFORE THE PRESSURE GRADIENT TIGHTENS AS A STRONG LOW PRESSURE
SYSTEM LIFTS INTO NORTHERN ONTARIO AND BRINGS WEST GALES THURSDAY
NIGHT INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
609 AM MDT MON OCT 1 2012
.SHORT TERM...VALID FOR TDY AND TUE...
UPDATE TO ADD AREAS OF FOG TO EASTERN ZONES WHERE SHOWERS
OCCURRED YESTERDAY. KBHK WAS REPORTING FOG THIS MORNING AND NEARBY
LOCATIONS HAD SMALL TEMPERATURE/DEWPOINT SPREADS. RAP SOUNDINGS
CAPTURED THE ONGOING FOG AND DISSIPATED IT BY 15Z.
.PREVIOUS DISCUSSION...
MODELS HAVE MAINTAINED CONSISTENCY WITH THE UPCOMING PATTERN
CHANGE FROM THEIR PREVIOUS RUNS. FOR TODAY AND TONIGHT...ALL MODELS
WERE IN GOOD AGREEMENT IN SHOWING AN ANTICYCLONIC/DRY NW FLOW OVER
THE FORECAST AREA TODAY...TRANSITIONING TO A FAST ZONAL FLOW
TONIGHT AS A STRONG PACIFIC JET SINKS S THROUGH WESTERN CANADA. A
STRONG SHORTWAVE...SEEN FROM THE GULF OF AK EXTENDING S ALONG THE
BC COAST IN WATER VAPOR IMAGERY EARLY THIS MORNING...WILL ROTATE
SE THROUGH THE PERIOD...REACHING MT ON TUE. THE GFS...ECMWF AND
CANADIAN MODELS WERE VERY SIMILAR WITH THE EVOLUTION OF THE
ENSUING TROUGH TUE THROUGH TUE NIGHT. THE WRF WAS SLOWER THAN THE
OTHER MODELS IN MOVING ENERGY SOUTHWARD IN THE WESTERN SIDE OF
THE TROUGH. WILL FOLLOW THE CONSISTENT GFS AND ECMWF FOR THE
FORECAST.
THE AIRMASS WILL BE DRY THROUGH TUE...THEN MOISTEN UP FROM NW TO
SE TUE NIGHT. EARLY MORNING SATELLITE IMAGERY AND BLENDED
PRECIPITABLE WATERS INDICATED A LARGE AMOUNT OF MOISTURE WITH THE
SYSTEM...SO MOISTURE SHOULD BE AVAILABLE TO THE SYSTEM AS IT
MOVES IN ON TUE NIGHT. THE GFS AND ECMWF CONTINUED TO INDICATE QPF
MOVING INTO THE AREA BEHIND THE COLD FRONT. THE GFS HAD THE FRONT
SINKING S THROUGH THE AREA AFTER 00Z WED. NORTHERLY LOW TO MID
LEVEL UPSLOPE FLOW...LIFT FROM THE TROUGH AND GOOD INSTABILITY
WILL SUPPORT THE DEVELOPMENT OF PRECIPITATION OVER THE AREA. ONLY
CHANGE TO POPS WAS TO TAPER THEM BACK OVER THE E DURING THE
EVENING BASED ON EXPECTED TIMING OF THE PRECIPITATION. THE COLD
AIR WILL MOVE IN SLOWLY TUE NIGHT AND MODEL SOUNDINGS INDICATED
THE BEST CHANCES FOR FROZEN PRECIPITATION WILL BE NEAR 5000 FT AGL
AND ABOVE. THUS WILL CONTINUE THE MIX OF RAIN AND SNOW W OF KBIL
AND KEEP KBIL AND AREAS E ALL RAIN TUE NIGHT. NOTED THE DENDRITIC
GROWTH ZONE REMAINED HIGH IN THE ATMOSPHERE TUE NIGHT AND WAS NOT
VERY DEEP...SO ANY SNOW ACCUMULATIONS WILL BE LIGHT.
AS FOR TODAY...MIXING WILL BE LIMITED TO BETWEEN 800 AND 700 MB
DUE TO A SUBSIDENCE INVERSION...THUS HAVE LOWERED TEMPERATURES A
BIT. HUMIDITIES WILL BE IN THE 20S AND WINDS WILL NOT BE VERY
STRONG. WINDS WILL INCREASE TONIGHT DUE TO A LEE TROUGH OVER THE
AREA...AND OVERNIGHT LOWS WILL BE HIGHER DUE TO A WARM 850 MB
AIRMASS. HAVE RAISED THE MINS A FEW DEGREES AND INCREASED WIND
SPEEDS. STRONG WESTERLY WINDS AHEAD OF THE COLD FRONT ON
TUE...WILL COMBINE WITH TEMPERATURES IN THE UPPER 70S TO MID
80S...AND LOW RELATIVE HUMIDITIES TO BRING THE POTENTIAL FOR
CRITICAL FIRE WEATHER CONDITIONS. EXPECT WINDS TO SHIFT TO THE NW
TUE AFTERNOON...THEN STRONG NORTHERLY WINDS WILL OVERTAKE THE
REGION TUE NIGHT. WILL CONTINUE THE FIRE WEATHER WATCH FOR TUE
AND TUE NIGHT. ARTHUR
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
LONG TERM MODELS CONSISTENCY STILL ON TRACK FOR SIGNIFICANT
WEATHER SYSTEM TO IMPACT OUR FORECAST AREA AT MIDWEEK. THE WRF
MODEL IS A DRIER OUTLIER WHICH WE ARE GENERALLY DISCOUNTING
AT THIS TIME...BUT EVEN ITS SOLUTION TAKES THE ENERGY FURTHER WEST
INTO IDAHO ALLOWING MUCH COOLER AIR AND UPSLOPE TO DEVELOP INTO
OUR REGION. THEREFORE...INHERITED TRENDS OF VERY COOL AND WET
FORECAST FOR MID WEEK LOOK ON TRACK. LOOK FOR TEMPERATURE CHANGE
BETWEEN TUESDAY AND WEDNESDAY TO BE ON THE ORDER OF 25 TO 30
DEGREES.
PRECIPITATION TYPE IS STILL A QUESTION MARK FOR THE LOWER
ELEVATIONS. FROM A BROAD PERSPECTIVE AND TAKING INTO ACCOUNT
DYNAMIC COOLING...UPSLOPE FLOW AND 850MB TEMP PROGGS...IT SEEMS
BEST ODDS FOR LOWER ELEVATION SNOW OR A MIX OF SNOW AND RAIN IS
WEST OF A ROUNDUP TO BRIDGER LINE. BILLINGS MAY SEE SOME MIXED
PRECIPITATION FOR A SHORT PERIOD OF TIME WEDNESDAY MORNING.
ACCUMULATING SNOWFALL IS EXPECTED IN THE BEARTOOTHS AND THEIR
FOOTHILLS INCLUDING RED LODGE. AT THIS TIME...THE LOW LEVEL
UPSLOPE LOOKS TO HAVE A DISTINCT NORTHERLY COMPONENT WHICH WILL
FAVOR NORTH FACING SLOPES WHICH SOMETIMES LIMITS AMOUNTS FROM NYE
TO ABSAROKEE...AND HITS HIGHER TERRAIN AROUND RED LODGE AND
ROSCOE. THE NORTHERLY COMPONENT COULD ALSO LIMIT PRECIPITATION IN
THE BILLINGS AREA AND SECTIONS OF WHEATLAND COUNTY WHICH CAN
EXPERIENCE DOWNSLOPE WITH A NORTHERLY WIND.
THE WEDNESDAY SYSTEM SLOWLY MOVES OUT BY THURSDAY MORNING LEAVING
AN UNSEASONABLY COOL AIR MASS IN ITS WAKE. THURSDAY NIGHT INTO
FRIDAY THE ECMWF HAS BEEN SUGGESTING ANOTHER POCKET OF SHORT WAVE
ENERGY DROPPING INTO THE BOTTOM OF THE CYCLONIC FLOW OVER THE
ROCKIES AND PRODUCING A GOOD SHOT OF UPSLOPE AND PRECIPITATION
INTO THE MOUNTAINS AND FOOTHILLS. THE GFS HAS TRENDED JUST A BIT
TOWARD THIS SOLUTION AS WELL WITH MUCH COOLER TEMPS FOR FRIDAY.
THEREFORE...WILL CONTINUE AN UNSETTLED AND RATHER COOL FORECAST
FOR THE LATTER HALF OF THE WORK WEEK. BT
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL OVER THE REGION AND TAF ROUTES TODAY.
LOOK FOR WESTERLY SURFACE WINDS TO INCREASE IN THE KLVM VICINITY
BY 18Z...REACHING 15 TO 25 KNOTS THROUGH THE AFTERNOON. BT
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 076 056/080 040/044 033/047 032/045 029/049 031/053
0/U 00/N 66/R 40/B 33/O 11/B 00/B
LVM 074 046/080 033/040 026/044 025/040 023/046 024/048
0/U 00/N 66/O 41/B 43/O 11/B 00/B
HDN 078 047/084 042/047 034/048 033/047 030/050 033/054
0/U 00/N 56/R 41/B 23/R 11/B 00/B
MLS 074 050/082 042/047 033/047 032/047 030/050 033/053
0/U 00/N 56/R 31/B 11/B 11/B 11/B
4BQ 072 050/084 040/048 035/047 032/047 030/049 033/052
0/U 00/U 46/R 31/B 22/R 11/B 10/B
BHK 070 044/076 034/047 032/045 031/046 030/049 031/051
0/U 00/U 56/O 32/W 12/R 11/B 11/B
SHR 072 043/083 042/044 030/045 030/044 027/045 029/049
0/U 00/U 36/R 51/B 24/O 21/B 01/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...RED FLAG WARNING IN EFFECT FROM 11 AM THIS MORNING TO
MIDNIGHT MDT TONIGHT FOR ZONE 117.
FIRE WEATHER WATCH IN EFFECT FROM TUESDAY MORNING THROUGH
LATE TUESDAY NIGHT FOR ZONES 123>133.
WY...FIRE WEATHER WATCH IN EFFECT FROM TUESDAY MORNING THROUGH
LATE TUESDAY NIGHT FOR ZONES 274-284.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
654 AM CDT MON OCT 1 2012
.AVIATION...12Z KGRI TAF. A FEW WEAK SHOWERS HAVE PASSED THROUGH
KGRI. THERE ARE STILL A FEW SPRINKLES ON RADAR NEAR ORD...BUT
THESE ARE INSIGNIFICANT AND WILL KEEP ALL MENTION OF ADDITIONAL
RAIN OUT OF THE TAF FOR NOW AS ADDITIONAL ACCUMULATING RAINFALL
SEEMS UNLIKELY. MID CLOUDS WILL HANG AROUND THROUGH THE MORNING
BUT EXPECT MOSTLY CLEAR SKIES BY AFTERNOON. THE NORTH WIND WILL
INCREASE IN STRENGTH THROUGH THE MORNING AND COULD BE RATHER GUSTY
AT TIMES THIS AFTERNOON WITH SOME GUSTS TO AROUND 35 MPH.
&&
.PREV DISCUSSION... /ISSUED 453 AM CDT MON OCT 1 2012/
SHORT TERM...TODAY THROUGH 12Z THURSDAY. MAIN FORECAST CHALLENGE
DURING THIS PERIOD WILL BE HIGH TEMPERATURES AHEAD OF THE COLD
FRONT ON WEDNESDAY AND PRECIPITATION TIMING/COVERAGE ON WEDNESDAY
NIGHT.
SOME SCATTERED LIGHT SHOWERS ARE LIKELY ACROSS THE OUTLOOK AREA
THIS MORNING. REFLECTIVITY AT 09Z SHOWED SHOWERS ACROSS NORTH
CENTRAL NEBRASKA IN THE VICINITY OF A SURFACE BOUNDARY. THESE
SHOWERS WERE HEADING SOUTH. SATELLITE IMAGERY ALSO INDICATED SOME
LIGHTNING STRIKES. HRRR AND RUC BOTH HAVE REFLECTIVITY CONTINUING
THROUGH 18Z. GOING TO LEAVE POPS IN FOR THE MORNING HOURS WITH
CHANCES DIMINISHING AROUND NOON FOR OUR CWA AS THE COLD FRONT
TRANSITIONS FARTHER SOUTH OUT OF THE REGION. THIS AFTERNOON WILL
BE BREEZY WITH SUSTAINED NORTHERLY WIND SPEEDS AROUND 20 KNOTS AS
ATMOSPHERIC MIXING GETS TO UP TO AROUND 700MB. WIND GUSTS WILL BE
CLOSER TO 30 KNOTS THIS AFTERNOON. WIND SPEEDS ARE EXPECTED TO
CALM DOWN AROUND 23Z WITH A CONTINUING TREND THEREAFTER. NEAR
CRITICAL FIRE WEATHER CONCERNS WILL BE EXPECTED THIS AFTERNOON.
HOWEVER...RELATIVE HUMIDITY VALUES WILL BE BETWEEN 25 AND 35
PERCENT AT ITS DRIEST POINT THIS AFTERNOON...SO THE OUTLOOK AREA
SHOULD BE SAFE FROM ANY FIRE WEATHER HEADLINES AT THIS TIME.
KANSAS FUEL STATUS IS UNFAVORABLE AT THIS TIME...BUT NEBRASKA
STILL REMAINS FAVORABLE FOR FIRE GROWTH UNDER THE RIGHT
CONDITIONS.
WEDNESDAY HIGH TEMPERATURES WERE RAISED A LITTLE AHEAD OF THE COLD
FRONT...MAINLY FOR NORTHWESTERN PARTS OF THE CWA TO ACCOUNT FOR
THE SLOWER TIMING OF THE COLD FRONT. THE THOUGHT IS ENOUGH DAYTIME
HEATING WILL OCCUR BEFORE THE COLD AIR ADVECTION BEGINS TO TAKE
CONTROL OF TEMPERATURES. THE GFS...GEM...AND THE EC ARE STRONGER
THAN THE NAM WITH REGARDS TO SURFACE...1000MB-500MB...AND 1000MB-
850MB COLD AIR ADVECTION...AND THE BULK OF THIS COLD AIR ADVECTION
DOESN/T REACH THE CWA UNTIL 00Z. LOWERED LOW TEMPERATURES
OVERNIGHT TO ACCOUNT FOR THIS COLDER AIRMASS. THE
NAM...HOWEVER...IS MUCH QUICKER THAN THE OTHER MODELS PREVIOUS
MENTIONED WITH REGARDS TO THE TIMING OF THE COLD AIR. OF
COURSE...THIS SCENARIO COULD CHANGE AS IT HAS OVER THE LAST
SEVERAL DAYS. NEIGHBORS AGAINST OUR CWA GENERALLY LEANED TOWARDS
THE WARMER TEMPERATURES AHEAD OF THE COLD FRONT.
PRECIPITATION CHANCES ARE DECENT ON WEDNESDAY NIGHT AS THE
SREF...GFS...EC...AND NAM ARE ALL IN PRETTY GOOD AGREEMENT WITH
TIMING AND COVERAGE. THE COLD FRONT WILL BE THE MAIN FACTOR LEADING
TOWARDS PRECIPITATION TIMING ACROSS THE OUTLOOK AREA...AS ENOUGH
MOISTURE SHOULD BE PRESENT IN THE LOWER TO MID LEVELS FOR
STRATIFORM RAIN. SEVERE WEATHER IS NOT EXPECTED. CHANCES DIMINISH
LATER IN THE DAY AS THE SURFACE LOW PROGGED TO BE OVER THE GREAT
LAKES REGION PUSHES EASTWARD...WITH THE SOUTHEASTWARD EXTENDING
COLD FRONT FOLLOWING SUIT.
THE FOLLOWING CHANGES WERE ALSO MADE FROM THE PREVIOUS FORECAST.
LOWERED HIGH TEMPERATURES ON MONDAY AND IN RETURN LOWERED
TEMPERATURES THAT NIGHT. TUESDAY HIGH TEMPERATURES WERE RAISED
SLIGHTLY ACROSS THE CWA BUT DID NOT CHANGE LOWS ON WEDNESDAY.
WENT WITH THE LATEST RUNS OF THE BCCONSALL FOR HIGHS ON MONDAY AND
WENT WITH THE ADJMAVBC FOR TUESDAY HIGHS...WITH SOME SLIGHT
MODIFICATIONS. TEMPERATURES WERE LOWERED ON TUESDAY MORNING. LOW
TEMPERATURES WERE LOWERED SEVERAL DEGREES ON THURSDAY AS A RESULT
OF THE STRONGER COLD AIRMASS PROGGED TO ENTER THE OUTLOOK AREA.
LONG TERM...THURSDAY THROUGH SUNDAY. TEMPERATURES WILL GENERALLY BE
10 TO 15 DEGREES BELOW NORMAL THROUGH THE PERIOD AND MAY EVEN
APPROACH 15 TO 20 DEGREES BELOW NORMAL ON SATURDAY BEHIND YET
ANOTHER STRONG COLD FRONT. NORMAL HIGHS ARE RIGHT AROUND 70
DEGREES AND WE WILL BE SEEING HIGHS PRIMARILY IN THE 50S. THE BEST
CHANCE FOR PRECIPITATION WILL BE FRIDAY NIGHT INTO SATURDAY AND WILL
NEED TO KEEP AN EYE ON PRECIPITATION TYPE.
THURSDAY...A FEW VERY LIGHT RAIN SHOWERS MAY LINGER OVER FROM
WEDNESDAY NIGHT PRIMARILY DURING THE MORNING HOURS FOR AREAS EAST OF
HIGHWAY 281. THE COLD FRONT WILL HAVE ALREADY PASSED THROUGH THE
ENTIRE CWA AND EXPECT COLD AIR ADVECTION THROUGH MUCH OF THE DAY
RESULTING IN HIGHS THAT ONLY REACH INTO THE 50S.
FRIDAY...TEMPERATURES WILL REMAIN COOL AND A REINFORCING COLD FRONT
WILL BE KNOCKING AT OUR DOOR BY LATE DAY...LIKELY TO SWING THROUGH
FRIDAY NIGHT. WILL KEEP FRIDAY DRY FOR NOW...BUT THERE ARE SOME
HINTS THAT SLIGHT POPS MAY BE NEEDED FOR LATE FRIDAY AFTERNOON AS
THE COLD FRONT NEARS.
FRIDAY NIGHT INTO SATURDAY...THERE WILL BE A DECENT CHANCE OF A
LIGHT COLD RAIN FRIDAY NIGHT INTO SATURDAY BEHIND THE COLD FRONT.
TEMPERATURES LATE FRIDAY NIGHT UNTIL JUST AFTER DAWN SATURDAY
MORNING WILL ONLY BE A FEW DEGREES ABOVE FREEZING ACROSS WESTERN
ZONES AND MAY BE COLD ENOUGH FOR A FEW WET SNOW FLAKES TO MIX IN.
WILL CONTINUE TO KEEP THE FORECAST ALL RAIN FOR NOW...BUT WILL NEED
TO CLOSELY MONITOR MODEL FORECAST TRENDS IN THE COMING DAYS. THE 00Z
GEM AND 00Z ECMWF ARE THE COLDEST AND WETTEST MODEL RUNS AND FOCUS
THE BEST CHANCE OF SEEING LIGHT PRECIPITATION OVER OUR WESTERN
COUNTIES AS WELL AS ACROSS NORTHERN KANSAS. EXPECT MODELS WILL
CONTINUE TO HAVE VARYING SWINGS IN FRONTAL POSITION UNTIL WE GET A
BIT CLOSER TO THE ACTUAL ARRIVAL OF THE FRONT. THE NEW CONSALL BLEND
WAS A GOOD DEAL COOLER THAN THE PREVIOUS FORECAST FOR SATURDAY AND
GIVEN THE CURRENT MODEL TRENDS DECIDED TO LOWER SATURDAY
TEMPERATURES EVEN FURTHER. AREAS THAT SEE LITTLE TO NO SUNSHINE MAY
NOT GET OUT OF THE 40S FOR HIGHS ON SATURDAY. HOWEVER...IF WE DO SEE
A LITTLE SUN THEN EXPECT HIGHS WILL MAKE THE 50S.
SUNDAY...DRY WEATHER WILL RETURN AND TEMPERATURES SHOULD SEE SOME
SLIGHT MODERATION WITH MORE SUNSHINE...ALTHOUGH HIGHS WILL LIKELY
STILL ONLY BE IN THE MID TO UPPER 50S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT...GUERRERO
LONG TERM/AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1040 AM EDT MON OCT 1 2012
.SYNOPSIS...
A WARM FRONT WILL MOVE NORTH OF THE AREA TODAY...AS LOW PRESSURE
OVER MISSISSIPPI THIS MORNING MOVES INTO TENNESSEE TONIGHT. THE LOW
WILL LIFT TO THE SOUTHERN GREAT LAKES BY WEDNESDAY. ITS ASSOCIATED
COLD FRONT WILL REACH THE FORECAST AREA TUESDAY NIGHT...MOVING OFF
THE COAST LATE WEDNESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST
LATE WEEK INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM MONDAY...WARM FRONT MAKING SLOW PROGRESS THROUGH THE
AREA NOW JUST SOUTH OF CONWAY AND NORTH OF KINGSTREE. ONLY A FEW
LIGHT SHOWERS REMAIN ACROSS NORTHERN MOST AREAS DUE TO THE BROAD
ISENTROPIC UPGLIDE ON THE 305K SURFACE. NAM AND HRRR SHOW A LULL FOR
SEVERAL HOURS AS AN AREA OF LOWER RH IN THE MID LEVELS...CAPTURED
WELL BY THE NAM AND SHOWN ON THE 1200 UTC CHS RAOB MOVES TO THE
NORTH. I HAVE TRIMMED BACK POPS FOR THE NEXT FEW HOURS THEN RAMPING
BACK UP AS SURFACE BASED INSTABILITY POSSIBLY DEVELOPS. HAVE
ADJUSTED POPS TO LIKELY LATE TONIGHT AS ANOTHER SWATH OF RAIN
DEVELOPS VIA SURFACE CONVERGENCE AND MOVES ONSHORE.
AS FOR TEMPERATURES...LOWER 80S MAY BE A TALL ORDER FOR NORTHEASTERN
AREAS DUE TO THE PROGRESS OF THE WARM FRONT AND OVERCAST SKIES.
WALKED BACK EXPECTED HIGHS A COUPLE OF DEGREES IN THESE AREAS WITH
THE CAVEAT FURTHER ADJUSTMENTS MAY BE NECESSARY WITH THE MIDDAY
UPDATE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...AMPLIFIED PATTERN OVER THE EASTERN US WILL
MAINTAIN DEEP SOUTHERLY FLOW OVER THE SOUTHEAST TUE. DEEP MOISTURE
WILL BE PLENTIFUL WITH PRECIPITABLE WATER VALUES EXCEEDING 2 INCHES
TUE MORNING AND REMAINING AT OR ABOVE 2 INCHES INTO WED. PLENTIFUL
MOISTURE COMBINED WITH ENHANCEMENT ALOFT FROM PASSING SHORTWAVES AND
WEAKLY DIVERGENT UPPER PATTERN ALONG WITH DIURNAL INSTABILITY SHOULD
MAKE FOR A FAIRLY ACTIVE PERIOD...AT LEAST UNTIL A WEAK COLD FRONT
MOVES INTO THE REGION DURING WED.
ONCE THE FRONT ARRIVES FORECAST CONFIDENCE DECREASES AS THE BOUNDARY
IS PROGGED TO STALL...BUT ITS EXACT LOCATION REMAINS IN QUESTION.
SOLUTIONS RANGE FROM IT STALLING ALONG OR JUST INLAND OF THE COAST
TO OVER THE WATERS ON WED. WHILE THE DISTANCE IS NOT SIGNIFICANT
TIMING THE ARRIVAL AND THE AMOUNT OF LOW LEVEL DRY AIR IS. HIGH
UNCERTAINTY COMBINED WITH WESTWARD EXPANSION OF MID LEVEL WESTERN
ATLANTIC RIDGE AND ITS SUBSIDENCE ALONG WITH INCREASING DRY AIR FROM
LOW LEVEL WEST TO NORTHWEST FLOW WILL BRING AN END TO PRECIP DURING
WED. MOISTURE ALOFT WILL ENSURE CLOUD COVER REMAINS IN PLACE THROUGH
THE END OF THE PERIOD. TUE INTO WED WILL BE THE HIGH POP PORTION OF
THE FORECAST WITH LIKELY TO CATEGORICAL REQUIRED. THINGS DRY OUT
WED. WILL CARRY LOW CHANCE ALONG THE COAST WITH SLIGHT CHANCE INLAND.
STRONG SOUTHERLY FLOW WILL HELP KEEP HIGHS ABOVE CLIMO TUE AND WED
DESPITE CLOUD COVER AND RAIN CHANCES. LOW LEVEL MOISTURE...CLOUD
COVER...AND MIXING WILL ALSO KEEP LOWS ABOVE CLIMO.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...MID LEVEL TROUGH LIFTING NORTHEAST AT THE START
OF THE PERIOD WILL HELP PUSH THE FRONT STALLED NEAR THE COAST
FARTHER OFFSHORE THU INTO FRI. INITIALLY FLOW ALOFT WILL BE
SOUTHWEST...BUT AS THE 5H TROUGH LIFTS NORTHEAST THE MID LEVEL
PATTERN BECOMES PROGRESSIVE. THIS RESULTS IN FLOW ALOFT BECOMING
WESTERLY WHICH HELPS MOVE THE FRONT OFF THE COAST. AS THE FRONT
HEADS EAST HIGH PRESSURE BUILDS IN FROM THE WEST SPREADING LOW AND
MID LEVEL DRY AIR OVER THE REGION. MOISTURE ABOVE 500 MB WILL
MAINTAIN HIGH CLOUDS BUT PRECIP IS NOT ANTICIPATED ON THU. DEEP DRY
AIR ARRIVES THU NIGHT INTO FRI AT WHICH POINT PRECIPITABLE WATER
VALUES DROP WELL BELOW 1 INCH. WEST TO NORTHWEST FLOW AT THE SURFACE
AND ALOFT CONTINUE FRI BUT SAT LOW LEVEL FLOW STARTS TO VEER TO
NORTHEAST AS SURFACE RIDGE AXIS BECOMES ELONGATED. RIDGE AXIS SHIFTS
OFFSHORE DURING SAT AND RETURN FLOW SETS UP AHEAD OF NEXT COLD
FRONT...WHICH MAY OR MAY NOT REACH THE REGION SUN. REGARDLESS RETURN
FLOW WILL INCREASE MOISTURE IN THE REGION AND MAY LEAD TO SOME
ISOLATED CONVECTION EARLY NEXT WEEK.
BOTH HIGHS AND LOWS WILL BE SLIGHTLY ABOVE CLIMO THROUGH THE
PERIOD...WITH A SUBTLE COOLING TREND LATE IN THE PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...IFR STRATUS ENTRENCHED THROUGHOUT THE CWA. THE WARM
FRONT WILL WAVE NORTHWARD TODAY...BUT THE STRATUS WILL LIKELY TRY TO
HOLD IN FOR MOST OF THE MORNING. THINK THE COASTAL TERMINALS WILL
SEE CONDITIONS IMPROVING FIRST...AS THE WARM FRONT EASES ONSHORE
WITH A WIND SHIFT TO THE EAST SOUTHEAST. CONVECTION MAY REFIRE THIS
AFTERNOON...BEST CHANCE ALONG THE COAST OF SOUTH CAROLINA WHERE
SOLAR INSOLATION WILL BE THE HIGHEST. TONIGHT...ANOTHER SLUG OF
MOISTURE WILL MOVE IN FROM THE SOUTH WITH SCATTERED SHOWERS.
VISIBILITIES COULD BRIEFLY GO IFR IN THE HEAVIEST ACTIVITY WITH
MAINLY MVFR CEILINGS.
EXTENDED OUTLOOK...UNSETTLED WEATHER ASSOCIATED WITH A STALLED FRONT
COULD PRODUCE PERIODS OF MVFR/IFR CONDITIONS ACROSS THE AREA THROUGH
FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM MONDAY...ALL IS RELATIVELY QUIET OVER THE COASTAL
WATERS AS 41013 IS SHOWING A LESS THAN ROBUST FOUR KNOTS WITH SEAS
JUST OVER TWO FEET. NO CHANGES TO THE FORECAST WITH THE MORNING
UPDATE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...SOUTHERLY FLOW IN THE 15 TO 20 KT TUE WILL
DECREASE ON WED AS COLD FRONT APPROACHES THE COAST FROM THE WEST.
FRONT IS SLOW TO MOVE OFF THE COAST WED...SO SOUTHERLY FLOW WILL
CONTINUE INTO AFTERNOON...BUT PROXIMITY TO THE FRONT WILL KEEP
GRADIENT WEAK THUS SPEEDS WILL ONLY BE 10 KT OR SO WED. FRONT PUSHES
OFF THE COAST LATE WED OR WED NIGHT WITH LIGHT OFFSHORE FLOW BEHIND
IT. NO COLD ADVECTION AND WEAK GRADIENT WILL KEEP FLOW UNDER 10 KT
THROUGH THE END OF THE PERIOD. SEAS WILL FLIRT WITH 6 FT AWAY FROM
SHORE IN STRONGER SOUTHERLY FLOW TUE INTO TUE NIGHT AND HEADLINES
MAY BE REQUIRED. SEAS WILL SUBSIDE WED AND WED NIGHT AS WINDS
DECREASE AND EVENTUALLY BECOME OFFSHORE.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...LIGHT WEST TO NORTHWEST FLOW EARLY IN THE PERIOD
WILL BECOME VARIABLE THU NIGHT INTO FRI AS STALLED COLD FRONT SLOWLY
MOVES EAST. LACK OF ANY SIGNIFICANT GRADIENT OR COLD ADVECTION WILL
KEEP SPEEDS UNDER 10 KT. LIGHT OFFSHORE FLOW FOLLOWED BY LIGHT
VARIABLE WINDS WILL KEEP SEAS AROUND 2 FT THROUGH THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...15
SHORT TERM...III
LONG TERM...III
AVIATION...43
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1043 AM CDT MON OCT 1 2012
.DISCUSSION...
MINOR UPDATES THIS MORNING. FORECAST CHALLENGE CONTINUES TO BE
CRITICAL FIRE WEATHER CONDITIONS THIS AFTERNOON (SEE FIRE
DISCUSSION BELOW). NAM TEMPS CAME IN A BIT COOLER FOR THIS AFTN
WHILE HRRR AND NAM WINDS WERE BOTH GENTLER THAN PREV FCST. GIVEN
GOOD ADIABATIC MIXING...DID NOT DROP WINDS AS MUCH AS 12Z GUIDANCE.
STILL EXPECT NORTH NORTHWEST FLOW FOR MOST OF AREA THIS AFTN. DAYTIME
HIGHS SHOULD BE WARMEST IN SOUTHERN VALLEY AND COOLEST IN THE
NORTHWEST WHERE OVERNIGHT LOWS WERE THE COLDEST. RIDGE AXIS WILL
MOVE ACROSS AFT 00Z...RESULTING IN LIGHTER WINDS AND A SHIFT TO A
SOUTHERLY COMPONENT BY MIDNIGHT.
&&
.AVIATION...
VFR CONDS WITH NNW FLOW GUSTING INTO THE 20 TO 25 MPH RANGE. WINDS
WILL SHIFT TO THE SOUTH BY LATE EVENING AS SFC RIDGE MOVES ACROSS VALLEY.
&&
.FIRE WEATHER...
WITH EXTREMELY DRY FUELS IN PLACE...RAPID FIRE GROWTH IS EXPECTED
TODAY...ESPECIALLY OVER WEST-CENTRAL AND NORTHWEST MINNESOTA. AS A
RESULT...A RED FLAG WARNING IS IN EFFECT FOR THIS AFTERNOON OVER
NORTHWEST AND WEST-CENTRAL MINNESOTA. RELATIVE HUMIDITY WILL FALL TO
AROUND 25 TO 30 PERCENT OVER THIS AREA. NORTHWEST WINDS WILL
STRENGTHEN TO 15 TO 20 MPH...WITH SOME GUSTS AROUND 25 MPH. WINDS WILL
GRADUALLY BEGIN TO DIMINISH A BIT DURING THE LATE AFTERNOON HOURS AS
A SFC RIDGE BUILDS INTO THE REGION.
CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED ACROSS THE ENTIRE
REGION ON TUESDAY...AND A FIRE WEATHER WATCH HAS BEEN ISSUED. A
STRONG LOW PRESSURE SYSTEM WILL MOVE ACROSS MANITOBA DURING THE
DAY...WITH WARM TEMPERATURES AND GUSTY SOUTH TO SOUTHWEST WINDS
AHEAD OF AN APPROACHING COLD FRONTAL BOUNDARY. AS TEMPERATURES
RISE INTO THE 70S...RELATIVE HUMIDITY IS EXPECTED TO FALL BELOW 20
PERCENT ALONG AND WEST OF THE RED RIVER VALLY...AND BELOW 25 PERCENT
FARTHER EAST. SUSTAINED WINDS OF 20 TO 30 MPH ARE EXPECTED WITH SOME
HIGHER GUSTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NDZ006>008-014>016-024-026>030-038-039-049-
052>054.
MN...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR MNZ001>009-013>017-022>024-027>032-040.
RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR MNZ001>009-
013>017-022>024-027>032-040.
&&
$$
SPEICHER/MAKOWSKI
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1038 AM CDT MON OCT 1 2012
.UPDATE...
CONVECTION DEVELOPING NORTH CENTRAL.
&&
.DISCUSSION...
A SMALL AREA OF CONVECTION HAS DEVELOPED IS MOVING SOUTHEASTWARD
INTO KERR COUNTY. THE CURRENT RAP MODEL SHOWS CONVECTION
CONTINUING THROUGH ABOUT NOON...BUT IS MISPLACED TO THE WEST. HAVE
UPDATED POPS AND WX TO SHOW A CHANCE FOR SHOWERS AND THUNDERSTORMS
DOWN INTO MEDINA AND WESTERN BEXAR COUNTIES. WILL SEE HOW THINGS
DEVELOP OVER THE NEXT COUPLE OF HOURS FOR POSSIBLE CHANGES FOR THE
AFTERNOON. MAY NEED TO INCREASE POPS FURTHER.
&&
.PREV DISCUSSION... /ISSUED 619 AM CDT MON OCT 1 2012/
AVIATION...
AN UPPER LEVEL DISTURBANCE WILL GENERATE ISOLD SHRA/TSRA TODAY
THROUGH THIS EVENING. FOR NOW...DUE TO UNCERTAINTY ON LOCATION OF
DEVELOPMENT AND SUBSEQUENT MOVEMENT...WILL LEAVE MENTION OUT OF
TAFS. HOWEVER...ONE OR MORE TAFS MAY HAVE TO BE UPDATED TO INCLUDE
MENTION WHEN IT BECOMES MORE CERTAIN. VFR SKIES WILL PREVAIL WITH
CLOUDS ABOVE 4K FT. DAYTIME MIXING WILL CREATE N TO NW WINDS 8 TO
15 KTS WITH SOME GUSTS TO 20 KTS. DECOUPLING AND A WEAK PRESSURE
GRADIENT WILL ALLOW FOR WINDS DECREASING TO 5 KTS OR LESS TONIGHT.
PREV DISCUSSION... /ISSUED 328 AM CDT MON OCT 1 2012/
DISCUSSION...
MAIN CHANGE THIS MORNING IS TO ADD ISOLATED SHOWERS AND THUNDERSTORMS
TO THE FCST FOR TODAY AND THIS EVENING. CONVECTIVE COMPLEX OVER THE
TRANS-PECOS REGION HAS BEEN MOVING SSE OVERNIGHT AND IS ENTERING
NORTHWEST VAL VERDE COUNTY. THIS IS A HARBINGER OF THINGS TO COME
FOR TODAY. THERE IS GOOD MODEL CONSENSUS FOR ISOLATED CONVECTION
ACROSS OUR CWFA TODAY AND THIS EVENING. THIS IS DUE TO AN UPPER
LEVEL DISTURBANCE THAT IS CURRENTLY LOCATED OVER THE TEXAS PANHANDLE.
THIS FEATURE WILL MOVE SOUTHWARD ACROSS OUR CWFA ALONG THE BACKSIDE
OF THE UPPER LEVEL TROF. THE HI-RES ARW AND NMM DO A GOOD JOB
CAPTURING THIS FEATURE AND ASSOCIATED QPF. COOLER TEMPS ALOFT IN
CONJUNCTION WITH ELEVATED CLOUD BASES MEAN THAT SOME OF THE
THUNDERSTORMS TODAY THRU THIS EVENING WILL HAVE THE POTENTIAL TO
PRODUCE SMALL HAIL WITH OUTFLOW WIND GUSTS OF 30 TO 40 MPH. HIGHS
TODAY WILL RANGE FROM NEAR 80 ACROSS THE HILL COUNTRY TO UPPER 80S
SOUTHWEST.
THE UPPER LEVEL TROF WILL FINALLY MOVE OFF TO THE EAST ON TUESDAY.
THIS WILL PLACE THE BEST UPPER LEVEL FORCING ACROSS SOUTHEAST
TEXAS AS ANOTHER DISTURBANCE ROUNDS THE BASE OF THE TROF. THE
UPPER LEVEL HIGH OVER BAJA CALIFORNIA WILL BUILD EASTWARD TOWARDS
TEXAS WEDNESDAY THRU FRIDAY WHILE A WEAK COLD FRONT WASHES OUT
ACROSS NORTHERN TEXAS ON THURSDAY. THIS PATTERN WILL KEEP SOUTH
CENTRAL TEXAS RAIN-FREE THRU THE END OF THE WEEK. ANOTHER COLD
FRONT WILL ENTER THE HILL COUNTRY SATURDAY NIGHT BUT UPPER LEVEL
SUPPORT IS WEAK SO DO NOT EXPECT SIGNIFICANT RAINFALL.
THE PATTERN OF COOL NIGHTS FOLLOWED BY WARM AFTERNOONS WILL PREVAIL
TODAY THRU WEDNESDAY. WEDNESDAY NIGHT GULF MOISTURE WILL BEGIN TO
ADVECT INLAND ACROSS SOUTH CENTRAL TEXAS AS THE SFC HIGH SHIFTS
EASTWARD. THIS WILL RESULT IN MORE HUMID CONDITIONS OVERNIGHT
THURSDAY INTO THE WEEKEND. AFTERNOON HIGHS WILL ALSO SHOW A
WARMING TREND AS THE WEEK PROGRESSES WITH THE DEPARTURE OF THE
UPPER LEVEL TROF AND ARRIVAL OF WEAK RIDGING ALOFT.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 83 60 83 61 88 / - 20 - 0 0
AUSTIN BERGSTROM INTL AIRPORT 83 59 82 55 87 / - 20 - 0 0
NEW BRAUNFELS MUNI AIRPORT 84 61 83 57 88 / 10 20 - 0 0
BURNET MUNI AIRPORT 81 58 80 58 86 / 10 20 - 0 0
DEL RIO INTL AIRPORT 88 62 84 62 92 / 10 10 - 0 0
GEORGETOWN MUNI AIRPORT 82 59 81 58 86 / - 10 - 0 0
HONDO MUNI AIRPORT 84 60 83 58 89 / 20 20 - 0 0
SAN MARCOS MUNI AIRPORT 84 60 83 57 88 / 10 20 - 0 0
LA GRANGE - FAYETTE REGIONAL 83 59 83 58 88 / - 10 - 0 0
SAN ANTONIO INTL AIRPORT 84 61 82 60 88 / 10 20 - 0 0
STINSON MUNI AIRPORT 84 61 83 60 89 / 10 20 - 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...05
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
313 PM MDT MON OCT 1 2012
.SHORT TERM...NORTHERLY WINDS ACROSS PLAINS HAVE PERSISTED A BIT
LONGER THAN ANTICIPATED...PROBABLY DUE TO A BIT MORE SUBSIDENCE
WITH NORTHERLY FLOW ALOFT. SHORT TERM MODELS CONTINUE TO SHOW A
WEAKENING NORTHERLY SURFACE PRESSURE GRADIENT BY 00Z WITH FLOW
BECOMING EASTERLY THEN SOUTHEAST DURING THE EVENING. WILL CONTINUE
THIS TREND OF DECREASING WINDS. OTHERWISE...FLOW ALOFT TO BECOME
MORE NORTHWEST AS UPPER RIDGE BUILDS INTO COLORADO FROM THE GREAT
BASIN. WINDS TO CONTINUE A BIT GUSTY OVER THE HIGHER RIDGES
OVERNIGHT. A COOL NIGHT EXPECTED TONIGHT UNDER CLEAR SKIES...
ALTHOUGH WINDS AND SOME WARMING ALOFT ACROSS MOUNTAINS AND
FOOTHILLS WILL KEEP MINS FROM PLUMMETING. ACROSS PLAINS...SHOULD
SEE OVERNIGHT TEMPERATURES IN THE LOWER AND MID 40S MOST AREAS...
SLIGHTLY COOLER IN LOW LYING AREAS. SOME POSSIBILITY FOR
DEVELOPMENT OF FROST FAR EASTERN PLAINS LATE TONIGHT BUT LOOKS TOO
LOCALIZED. ON TUESDAY...DRY NORTHWEST FLOW ALOFT TO PREVAIL WITH
UPPER RIDGE OVER STATE. BOTH NAM AND GFS SHOW 700 MB TEMPS WARMING
TO AROUND +11 DEGREES C. THUS...SHOULD SEE TEMPERATURES ACROSS
MOST OF PLAINS WARMING INTO THE LOWER AND MIDDLE 80S. MODELS
SUGGEST SOME MIXING OF THE NORTHWEST WINDS DURING THE AFTERNOON
MAINLY NEAR THE WYOMING BORDER ALONG WITH HUMIDITY READINGS IN THE
TEENS. WINDS AND HUMIDITY MAY BRIEFLY REACH CRITICAL FIRE WEATHER
THRESHOLDS...THOUGH DURATION LOOKS BRIEF. SOME UNCERTAINTIES ON
STATUS OF FUELS GIVEN RECENT PRECIPITATION. SO NO FIRE WEATHER
HILITES AT THIS TIME.
.LONG TERM...MAJOR CHANGES ON THE WAY FOR MUCH OF THE LONGER TERM
THIS WEEK...ESPECIALLY IN TERMS OF COLDER TEMPERATURES FROM
THURSDAY ONWARD THROUGH THE WEEKEND. INITIALLY AN UPPER LEVEL
TROF WILL CARVE OUT ACROSS THE NORTHERN ROCKIES BEFORE SWEEPING
ACROSS NORTHEAST COLORADO AND THE CENTRAL PLAINS WEDNESDAY NIGHT
AND EARLY THURSDAY. THERE IS SOME DIFFERENCES IN THE TIMING OF THE
COLD FRONT AS THE NAM BRINGS AN INITIAL SURGE EARLIER IN THE DAY
ON WEDNESDAY WHILE GFS IS LATER. HIGH TEMPERATURES WILL BE TRICKY
AND WILL PLAY MIDDLE OF THE ROAD FOR NOW WITH READINGS IN THE 60S
AND SOME LOWER 70S OVER SOUTHERN PORTIONS OF CWA. THE COLDER AIR
WILL BLAST THROUGH WEDNESDAY NIGHT. AS IN PREVIOUS DAYS...MOISTURE
STILL LOOKS SUSPECT AND RATHER LIMITED SO WILL KEEP POPS IN THE
20-30 PERCENT RANGE...HIGHEST OVER THE FAR EAST PLAINS. GIVEN
THE COLD AIR THERE COULD EVEN BE SOME RAIN MIX WITH SNOW ON THE
PLAINS OVERNIGHT WEDNESDAY BUT DOUBT IF THERE WILL BE LITTLE IF
ANY ACCUMULATION. THURSDAY WILL BE COOL AND GENERALLY DRY WITH
READINGS ONLY IN THE 50S.
ANOTHER DISTURBANCE AND SHOT OF REINFORCING COLD AIR IS PROGGED TO
MOVE INTO NORTHERN COLORADO LATE FRIDAY AND SATURDAY WITH EVEN
COLDER TEMPERATURES FORECAST. THERE SEEMS TO BE MORE MOISTURE WITH
THIS SYSTEM SO WILL BUMP POPS UP A BIT WITH THIS FORECAST PACKAGE
AND AGAIN COULD BE COLD ENOUGH FOR SOME RAIN/SNOW MIX ON THE
PLAINS. THERE ARE QUITE A FEW MODEL DIFFERENCES ON HOW THE
WEEKEND PATTERN EVOLVES...AND HOW THE CUTOFF LOW OFF WEST COAST
BEHAVES. WON`T GET TOO EXCITED YET BUT CERTAINLY BEARS WATCHING
FOR OUR BEST CHANCE OF POSSIBLE SNOWFALL. CERTAINLY FROM THURSDAY
AM AND THRU THE WEEKEND WE WILL HAVE SOME FROST/FREEZE POTENTIAL
SO TIME TO START FINISHING OUTDOOR ACTIVITIES...INCLUDING ANY
GARDEN FOOD REMAINS AND SHUTTING DOWN SPRINKLER SYSTEMS.
&&
.AVIATION...SURFACE WINDS FINALLY SHOWING MORE OF A NORTHEAST
COMPONENT IN RESPONSE TO NORTHEAST SURFACE GRADIENT. BOTH HRRR AND
RUC INDICATE NORTHEAST WINDS TO PERSIST UNTIL 22Z WITH SPEEDS
AROUND 12 KTS...THEN WEAKEN AND BECOME EASTERLY BY 00Z. THIS TREND
LOOKING ON TRACK. WINDS TO BECOME SOUTHERLY DURING THE EVENING AS
DRAINAGE PATTERN DEVELOPS WITH SPEEDS AROUND 8 KTS. LATEST NAM
SHOWS WINDS BECOMING NORTHWEST AROUND 16Z TIME WHILE GFS CONTINUES
MORE OF A SOUTHERLY DIRECTION. WITH THE POTENTIAL FOR SOME MIXING
OF THE NORTHWEST WIND...WILL LEAN TOWARD THE NAM SOLUTION AT THIS
TIME. OTHERWISE VFR TO CONTINUE WITH UNLIMITED CEILING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....ENTREKIN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1132 AM MDT MON OCT 1 2012
.UPDATE...
ISSUED AT 902 AM MDT MON OCT 1 2012
MAIN CHANGE WAS TO INCREASE THE WINDS FOR THE DAY OVER THE EAST
HALF OF THE AREA. LATEST VAD WINDS FROM THE RADAR SHOW WINDS OF
30KTS ABOVE THE SURFACE. LATEST NAM MIXED LAYER WINDS HAVE
STRENGTHENED TO MATCH THE MOS OUTPUT...SUGGESTING GUSTS MAY REACH
40 MPH EAST OF A STRATTON NEBRASKA TO RUSSELL SPRINGS LINE DURING
THE EARLY AFTERNOON. AFTER THAT THE STRONGER WINDS MOVE SOUTH.
DID HOLD ONTO THE SLIGHT CHANCES OVER THE EAST HALF DURING THE
MORNING SINCE THE LEFT EXIT OF THE 300MB JET WILL BE OVER THE
AREA. IF ANY STORMS DO DEVELOP THEY WILL BE WIDELY SCATTERED AT
BEST AND MOVE OUT BY THE EARLY AFTERNOON AS THE LEFT EXIT OF THE
JET MOVES SOUTHEAST.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 216 AM MDT MON OCT 1 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW LONG WAVE TROUGH
EXTENDING SOUTH ACROSS THE EASTERN CONUS...WITH TWO CLOSED LOW
CENTERS OVER NEW ENGLAND AND ANOTHER OVER THE SOUTHERN MISSISSIPPI
VALLEY. A LARGE SCALE RIDGE EXTENDS NORTH ACROSS THE WESTERN
CONUS...WITH NORTH TO NORTHWEST FLOW OVER THE PLAINS. AT THE
SURFACE A COLD FRONT HAS DROPPED SOUTH ACROSS THE NORTHEAST PART
OF THE CWA.
ISOLATED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ALONG THIS FRONT
NEAR AN AXIS OF H85 FRONTOGENESIS IN THE NORTHWEST. THIS ACTIVITY
SHOULD CONTINUE TO SPREAD SOUTHEAST ACROSS THE REST OF THE FORECAST
AREA THROUGH THE EARLY MORNING HOURS. THE FRONT SHOULD BE SOUTH OF
THE CWA BY THE AFTERNOON...WITH SUBSIDENCE BUILDING IN FROM THE
WEST. I LEFT LINGERING POPS IN PLACE ACROSS THE EAST THROUGH THE IN
PROXIMITY TO FRONT WHERE GUIDANCE CONTINUES TO INDICATE LIGHT QPF.
PRECIP AMOUNTS SHOULD BE LOW WITH A FEW HUNDREDTHS OF AN INCH AT THE
MOST.
OVERALL TREND SHOULD BE CLEARING BY THIS EVENING WITH SUBSIDENCE
OVERSPREADING THE AREA FROM THE WEST. HIGH TEMPERATURES TODAY WILL
BE ABOUT 10 TO 15F COOLER THAN SUNDAY WITH HIGHS IN THE 60S/70S
ACROSS THE CWA. THE AIR MASS TONIGHT LOOKS VERY SIMILAR TO OUR LAST
FEW COOL-DOWNS...SO I USED THAT AS A BASIS FOR MY LOW TEMPERATURE
FORECAST. WITH CLEAR SKIES AND CALM WINDS EXPECTED TEMPERATURES
SHOULD DROP INTO THE LOW 40S ACROSS MUCH OF THE AREA...WITH
TRADITIONAL COLD SPOTS IN THE MID TO UPPER 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 336 AM MDT MON OCT 1 2012
SHORTWAVE RIDGING BUILDS OVER THE TRI-STATE AREA TUESDAY AND
WEDNESDAY...WITH DRY CONDITIONS EXPECTED. A WARM FRONT WILL MOVE
ACROSS THE REGION TUESDAY WITH TEMPERATURE WARMING BACK INTO THE
UPPER 70S/LOW 80S. A COLD FRONT WILL DROP SOUTH INTO THE REGION LATE
WEDNESDAY OR WEDNESDAY NIGHT. OVERALL TREND HAS BEEN TO SPEED UP
THIS FRONTAL PASSAGE. WITH THE AMOUNT OF SPREAD BETWEEN MODELS ON
THIS FEATURE...CONFIDENCE IS LOW ON TEMPERATURE FORECAST WED. LARGE
SCALE ASCENT BUILDS OVER THE REGION WEDNESDAY NIGHT BEHIND THIS
FRONT AS ITS PARENT TROUGH MOVES ACROSS NORTHERN PLAINS. BEST
MOISTURE ADVECTION/LIFT SHOULD BE ACROSS THE NORTH...SO I KEPT
CHANCE POPS MAINLY NORTH OF I-70.
A DEFINITE CHANGE TO THE WEATHER BY LATE IN THE WEEK AS MUCH COLDER
TEMPERATURES ARE USHERED IN BEHIND A STRONG COLD FRONT THAT WILL MOVE
ACROSS THE PLAINS WEDNESDAY AFTERNOON. A SURFACE HIGH WILL BEGIN TO
BUILD INTO THE CENTRAL PLAINS ON THURSDAY BEHIND THE COLD FRONT AS
THE UPPER LEVEL LOW MOVES INTO THE GREAT LAKES REGION. FORECAST GETS
A LITTLE COMPLICATED LATE FRIDAY AND INTO THE WEEKEND. BROAD TROUGH
WITH CLOSED LOW OVER THE GREAT LAKES WILL SWING ANOTHER SHORTWAVE
TROUGH THROUGH THE NORTHERN PLAINS. MODELS ARE IN AGREEMENT WITH
THIS SHORTWAVE TROUGH...BUT DISAGREE ON THE MAGNITUDE AND SPEED OF
THE SYSTEM. ANOTHER CLOSED LOW WILL BE DEEPENING OFF THE COAST OF
CALIFORNIA AND WILL SLOWLY BEGIN TO MOVE ONSHORE BY EARLY NEXT WEEK.
THIS WILL KEEP THE REGION UNDER NEAR ZONAL TO NORTHWEST FLOW ALOFT.
NEAR THE SURFACE...A REINFORCING SHOT OF COLDER AIR WILL SLIDE DOWN
FROM CANADA AND INTO THE CENTRAL PLAINS BY THE WEEKEND. THIS NEXT
SHOT OF COLD AIR WILL ONLY ALLOW HIGHS TO CLIMB INTO THE 40S AND
MAYBE LOW 50S ON SATURDAY. THIS WILL ALSO BE OUR BEST CHANCE TO HAVE
OUR FIRST HARD FREEZE THIS SEASON AS MODELS AGREE THAT TEMPERATURES
WILL DROP INTO THE LOW TO MID 30S BOTH SAT AND SUN MORNINGS.
AS FOR PRECIPITATION CHANCES...MODELS ARE IN AGREEMENT THAT A COLD
WET WEEKEND IS A HIGH PROBABILITY. BEST POSSIBILITY LOOKS TO BE
FRIDAY NIGHT THROUGH SATURDAY AS THE SHORTWAVE TROUGH BEGINS TO MOVE
ACROSS THE NORTHERN PLAINS AND THE NEXT COLD SURGE SLIDES SOUTHWARD.
THE COLDER MODEL SOLUTIONS HAVE HINTED THAT A CHANCE FOR A RAIN/SNOW
MIX MAY BE POSSIBLE IN SOME PARTS OF THE TRI STATE REGION. GIVEN
THAT THIS IS PRETTY LATE IN THE EXTENDED PERIOD...WILL WAIT AND SEE
IF THIS TREND CONTINUES. FOR NOW...HAVE JUST KEPT RAIN SHOWERS IN
THE FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1129 AM MDT MON OCT 1 2012
VFR CONDITIONS FORECAST FOR THE 18Z TAFS. GUSTY WINDS WILL
CONTINUE THROUGH THE AFTERNOON FOR BOTH SITES...ALTHOUGH A GRADUAL
DECREASE CAN BE EXPECTED LATE THIS AFTERNOON. WINDS WILL BECOME
LIGHT TONIGHT AS MIXING CEASES AND A SURFACE HIGH PRESSURE MOVES
IN. DRY CONDITIONS CONTINUE TUESDAY AS AN UPPER LEVEL RIDGE
REMAINS OVER THE AREA.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...PMM
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
114 PM EDT MON OCT 1 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EDT MON OCT 1 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THE WRN GREAT LAKES TO JAMES BAY BETWEEN A LOW OVER NRN NEW ENGLAND
AND A TROUGH FROM MANITOBA INTO NORTH DAKOTA. AT THE SFC...A COLD
FRONT EXTENDED FROM NEAR PICKLE LAKE ONTARIO INTO ERN MN. RADAR
SHOWED SOME WEAK REFLECTIVITIES N CNTRL MN ALIGNED WITH WEAK TO
MODERATE MID LEVEL EVEN THOUGH SFC OBS INDICATED LITTLE MORE THAN
SOME MID CLOUDS. OTHERWISE...HIGH CLOUDS SPREADING ACROSS UPPER MI
AND WEAK SW WINDS HAVE KEPT TEMPS FROM FALLING OFF AS MUCH WITH
READINGS IN THE UPPER 30S AND LOWER 40S INLAND AND NEAR 50 ALONG
LAKE SUPERIOR.
AS THE MANITOBA MID LEVEL TROUGH PROGRESSES TO THE EAST TODAY AND
TONIGHT...THE COLD FRONT WILL ALSO SPREAD ACROSS UPPER MI. SINCE
THERE IS LITTLE MOISTURE INFLOW INTO THE RELATIVELY DRY AIR MASS AND
THE STRONGER 850-500 MB QVECTOR CONV REMAINS NORTH OF LAKE
SUPERIOR...RAIN CHANCES WILL BE MINIMAL. HOWEVER...WITH THE BAND OF
850-600 MB FGEN MOVING INTO THE WEST THIS EVENING...SOME ISOLATED
LIGHT SHOWERS OR SPRINKLES MAY BE POSSIBLE. POTENTIAL FOR ANY LAKE
ENHANCED PCPN WITH NRLY FLOW BEHIND THE FRONT ALSO WILL BE MINIMAL
WITH 850 MB TEMPS ONLY DROPPING TO AROUND 5C (LAKE SFC TEMPS WERE IN
THE 11C TO 14C RANGE).
EVEN WITH INCREASING MID/HIGH CLOUDS...WAA WILL HELP PUSH TEMPS INTO
THE MID AND UPPER 60S. CLOUDS WITH LINGERING 925-850 MB MOISTURE
OVER THE AREA WILL HOLD MIN READINGS IN THE 40S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 518 AM EDT MON OCT 1 2012
MAIN CONCERN PAST 12Z TUE IS WITH A DEEP UPPER TROUGH MOVING INTO
THE AREA THU...AND STAYING THROUGH THE WEEKEND.
FIRST FOR WED INTO EARLY WED NIGHT...AN UPPER TROUGH OVER THE LOWER
MISSISSIPPI VALLEY WILL SHEAR OFF AND MOVE SE OF THE CWA...WHICH MAY
PRODUCE SOME RAIN OVER THE FAR ERN CWA. PREVIOUS FORECAST WITH
CHANCE POPS OVER THE FAR E LOOKS GOOD SO WILL LEAVE THAT MOSTLY
UNCHANGED.
THEN FOR THE MAIN EVENT THU THROUGH SUN. MAIN IDEA FROM THE MODELS
IS THAT AS THE UPPER TROUGH MOVES INTO THE REGION...THE SRN END OF
THE TROUGH WILL BECOME NEGATIVELY TILTED RESULTING IN THE TROUGH
DEEPENING AND CLOSING OFF SOMEWHERE OVER OR NEAR THE CWA.
COMPLICATING MATTERS...ENERGY FROM THE TROUGH WILL SPLIT BETWEEN THE
SRN END AND THE MORE NRN END (OVER FAR NRN ONTARIO)...AND IT IS
DIFFICULT TO DETERMINE HOW MUCH OF THE ENERGY WILL GO TO THE SRN VS.
NRN END. THIS SEEMS TO BE ONE REASON WHY MODELS HAVE POOR RUN TO RUN
CONTINUITY AND POOR AGREEMENT WITH HOW TO HANDLE THIS SYSTEM. LATEST
RUN OF THE GFS (00Z/01) IS MORE LIKE THE LAST COUPLE RUNS OF THE
ECMWF...BRINGING A MODERATELY DEEPENING SFC LOW FROM WRN LAKE
SUPERIOR AROUND 12Z THU TO JAMES BAY BY 18Z FRI. THERE ARE STILL
SIGNIFICANT DIFFERENCES BETWEEN THE GFS AND ECMWF...BUT THE LATEST
RUN AGREES MORE WITH THE ECMWF THAN THE LAST RUN WITH SHOWING THE
LOW RAPIDLY DEEPENING AS IT MOVED THROUGH THE CENTER OF THE CWA. THE
GEM HAS THE SAME GENERAL IDEA BUT FARTHER N OVER ONTARIO. THE IDEA
OF A DEEPENING SYSTEM MOVING UP THE WRN SIDE OF LAKE SUPERIOR SEEMS
LIKE A REASONABLE AND FAMILIAR SCENARIO...BUT THE TRACK OF THIS
SYSTEM WILL BE VERY TRICKY TO FORECAST. EVEN IF MODEL AGREEMENT WAS
GREAT WITH THIS SYSTEM...THE FACT THAT THE TRACK OF THIS TYPE OF
SYSTEM IS HARD TO FORECAST THIS FAR OUT COMBINED WITH THE FACT THAT
THE SYSTEM HAS NOT MOVED INTO THE N AMERICAN PROFILING NETWORK YET
WOULD STILL LEAVE LITTLE CONFIDENCE IN THE FORECAST FOR THU/FRI. FOR
THIS REASON...AT THIS TIME IT IS NEARLY FUTILE TO MAKE LARGE
ADJUSTMENTS TO THE FORECAST FOR THU/FRI BASED ONLY ON THE LAST RUN
OF THE MODELS...ESPECIALLY GIVEN THE RUN TO RUN DISCONTINUITY FROM
THE MODELS AND THE FACT THAT THE TRACK OF THIS SYSTEM WILL HAVE HUGE
BEARING ON THE FORECAST.
THERE ARE SOME THINGS WE CAN LOOK AT THAT ARE MORE CERTAIN WITH THIS
SYSTEM...LIKE THE COLD AIR AND NW LOW LEVEL WINDS BEHIND THE SYSTEM.
850MB TEMPS FALL BELOW 0C BY LATE THU...AND GET PROGRESSIVELY COLDER
THROUGH FRI NIGHT (ALTHOUGH THE GFS WITH 850MB TEMPS OF -7C TO -9C
AT 12Z SAT IS 3-4C COLDER THAN THE ECMWF). THIS WILL LEAD TO LAKE
ENHANCE/EFFECT RAIN/SNOW IN NW WIND SNOWBELTS BEHIND THE SYSTEM INTO
SUN...WITH DECREASING LOW LEVEL MOISTURE LATE SAT INTO SUN MAKING
FOR MORE SCATTERED COVERAGE. THERE IS POTENTIAL FOR THE FIRST
ACCUMULATING SNOWFALL...ESPECIALLY OVER THE HIGHER TERRAIN OF WRN
UPPER MI WHERE LOW LEVEL TEMPS WILL BE COOLER. ANOTHER MORE CERTAIN
ASPECT WITH THE SYSTEM IS WLY GALES BEHIND THE LOW...ESPECIALLY IF
THE SFC LOW STICKS TO THE LAKE LONGER THAN MODELS SHOW AS IS COMMON
THIS TIME OF YEAR. WITH THE LOW DEEPENING AS IT MOVES OVER OR NEARBY
AND GOOD PRESSURE GRADIENT AND COLD AIR BEHIND THE SYSTEM...GALES
SHOULD BE ON THE STRONG SIDE AND WIND ADVISORIES/WARNINGS MAY BE
NEEDED ON LAND AS WELL...PARTICULARLY OVER THE KEWEENAW PENINSULA
AND ERN UPPER MI NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 113 PM EDT MON OCT 1 2012
A COLD FRONT WILL CROSS THE AREA THIS AFTERNOON...BUT THE
AIRMASS IS TOO DRY TO SUPPORT MUCH IN THE WAY OF SHRA OR EVEN LOW
CLOUDS. AFTER THE COLD FROPA...SOME LOWER CLDS MIGHT ARRIVE AT
IWD/CMX TOWARD LATE AFTN WITH AN UPSLOPE NW FLOW AND THEN AT SAW
LATER IN THE EVNG. ALTHOUGH THERE IS THE POTENTIAL FOR MVFR
CONDITIONS THAT MIGHT IMPACT THESE SITES...THE MOST FAVORABLE
UPSLOPE AND MOISTENING IS LIKELY AT KSAW WHERE IFR CIGS ARE MORE
LIKELY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 AM EDT MON OCT 1 2012
A COLD FRONT WILL MOVE THROUGH LAKE SUPERIOR TODAY INTO TONIGHT. A
PERIOD OF MODERATE NRLY WINDS TO 25 KNOTS OVER CNTRL AND ERN LAKE
SUPERIOR IS EXPECTED JUST BEHIND THE FRONT LATE THIS EVENING AND
OVERNIGHT. OTHERWISE...WINDS WILL STAY BELOW 20 KNOTS INTO THURSDAY
BEFORE THE PRESSURE GRADIENT TIGHTENS AS A STRONG LOW PRESSURE
SYSTEM LIFTS INTO NORTHERN ONTARIO AND BRINGS WEST GALES THURSDAY
NIGHT INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1238 PM CDT MON OCT 1 2012
.AVIATION...18Z KGRI TAF...VFR CONDS WILL PREVAIL AT KGRI FOR THE
NEXT 24 HOURS WITH WINDS BEING THE PRIMARY CONCERN THROUGH THE
PERIOD. EXPECT MID LEVEL CLOUD DECK TO CONTINUE TO CLEAR ACROSS
THE AREA OVER THE NEXT COUPLE OF HOURS...WITH GUSTY NORTH TO
NORTHWESTERLY WINDS TO 30KTS EXPECTED TO CONTINUE TIL AROUND 00Z.
THEREAFTER...WINDS WILL SLOWLY RELAX DURING THE EVENING
HOURS...EVENTUALLY BECOMING LIGHT AND VARIABLE OVERNIGHT AS AN
AREA OF SURFACE HIGH PRESSURE SLIDES SOUTHWARD ACROSS THE REGION.
WINDS WILL THEN GENERALLY REMAIN LIGHT AND WESTERLY ACROSS THE
REGION ON TUESDAY...AS THE SURFACE HIGH SLIDES FURTHER SOUTH INTO
THE SOUTHERN PLAINS.
&&
.PREV DISCUSSION... /ISSUED 453 AM CDT MON OCT 1 2012/
SHORT TERM...TODAY THROUGH 12Z THURSDAY. MAIN FORECAST CHALLENGE
DURING THIS PERIOD WILL BE HIGH TEMPERATURES AHEAD OF THE COLD
FRONT ON WEDNESDAY AND PRECIPITATION TIMING/COVERAGE ON WEDNESDAY
NIGHT.
SOME SCATTERED LIGHT SHOWERS ARE LIKELY ACROSS THE OUTLOOK AREA
THIS MORNING. REFLECTIVITY AT 09Z SHOWED SHOWERS ACROSS NORTH
CENTRAL NEBRASKA IN THE VICINITY OF A SURFACE BOUNDARY. THESE
SHOWERS WERE HEADING SOUTH. SATELLITE IMAGERY ALSO INDICATED SOME
LIGHTNING STRIKES. HRRR AND RUC BOTH HAVE REFLECTIVITY CONTINUING
THROUGH 18Z. GOING TO LEAVE POPS IN FOR THE MORNING HOURS WITH
CHANCES DIMINISHING AROUND NOON FOR OUR CWA AS THE COLD FRONT
TRANSITIONS FARTHER SOUTH OUT OF THE REGION. THIS AFTERNOON WILL
BE BREEZY WITH SUSTAINED NORTHERLY WIND SPEEDS AROUND 20 KNOTS AS
ATMOSPHERIC MIXING GETS TO UP TO AROUND 700MB. WIND GUSTS WILL BE
CLOSER TO 30 KNOTS THIS AFTERNOON. WIND SPEEDS ARE EXPECTED TO
CALM DOWN AROUND 23Z WITH A CONTINUING TREND THEREAFTER. NEAR
CRITICAL FIRE WEATHER CONCERNS WILL BE EXPECTED THIS AFTERNOON.
HOWEVER...RELATIVE HUMIDITY VALUES WILL BE BETWEEN 25 AND 35
PERCENT AT ITS DRIEST POINT THIS AFTERNOON...SO THE OUTLOOK AREA
SHOULD BE SAFE FROM ANY FIRE WEATHER HEADLINES AT THIS TIME.
KANSAS FUEL STATUS IS UNFAVORABLE AT THIS TIME...BUT NEBRASKA
STILL REMAINS FAVORABLE FOR FIRE GROWTH UNDER THE RIGHT
CONDITIONS.
WEDNESDAY HIGH TEMPERATURES WERE RAISED A LITTLE AHEAD OF THE COLD
FRONT...MAINLY FOR NORTHWESTERN PARTS OF THE CWA TO ACCOUNT FOR
THE SLOWER TIMING OF THE COLD FRONT. THE THOUGHT IS ENOUGH DAYTIME
HEATING WILL OCCUR BEFORE THE COLD AIR ADVECTION BEGINS TO TAKE
CONTROL OF TEMPERATURES. THE GFS...GEM...AND THE EC ARE STRONGER
THAN THE NAM WITH REGARDS TO SURFACE...1000MB-500MB...AND 1000MB-
850MB COLD AIR ADVECTION...AND THE BULK OF THIS COLD AIR ADVECTION
DOESN/T REACH THE CWA UNTIL 00Z. LOWERED LOW TEMPERATURES
OVERNIGHT TO ACCOUNT FOR THIS COLDER AIRMASS. THE
NAM...HOWEVER...IS MUCH QUICKER THAN THE OTHER MODELS PREVIOUS
MENTIONED WITH REGARDS TO THE TIMING OF THE COLD AIR. OF
COURSE...THIS SCENARIO COULD CHANGE AS IT HAS OVER THE LAST
SEVERAL DAYS. NEIGHBORS AGAINST OUR CWA GENERALLY LEANED TOWARDS
THE WARMER TEMPERATURES AHEAD OF THE COLD FRONT.
PRECIPITATION CHANCES ARE DECENT ON WEDNESDAY NIGHT AS THE
SREF...GFS...EC...AND NAM ARE ALL IN PRETTY GOOD AGREEMENT WITH
TIMING AND COVERAGE. THE COLD FRONT WILL BE THE MAIN FACTOR LEADING
TOWARDS PRECIPITATION TIMING ACROSS THE OUTLOOK AREA...AS ENOUGH
MOISTURE SHOULD BE PRESENT IN THE LOWER TO MID LEVELS FOR
STRATIFORM RAIN. SEVERE WEATHER IS NOT EXPECTED. CHANCES DIMINISH
LATER IN THE DAY AS THE SURFACE LOW PROGGED TO BE OVER THE GREAT
LAKES REGION PUSHES EASTWARD...WITH THE SOUTHEASTWARD EXTENDING
COLD FRONT FOLLOWING SUIT.
THE FOLLOWING CHANGES WERE ALSO MADE FROM THE PREVIOUS FORECAST.
LOWERED HIGH TEMPERATURES ON MONDAY AND IN RETURN LOWERED
TEMPERATURES THAT NIGHT. TUESDAY HIGH TEMPERATURES WERE RAISED
SLIGHTLY ACROSS THE CWA BUT DID NOT CHANGE LOWS ON WEDNESDAY.
WENT WITH THE LATEST RUNS OF THE BCCONSALL FOR HIGHS ON MONDAY AND
WENT WITH THE ADJMAVBC FOR TUESDAY HIGHS...WITH SOME SLIGHT
MODIFICATIONS. TEMPERATURES WERE LOWERED ON TUESDAY MORNING. LOW
TEMPERATURES WERE LOWERED SEVERAL DEGREES ON THURSDAY AS A RESULT
OF THE STRONGER COLD AIRMASS PROGGED TO ENTER THE OUTLOOK AREA.
LONG TERM...THURSDAY THROUGH SUNDAY. TEMPERATURES WILL GENERALLY BE
10 TO 15 DEGREES BELOW NORMAL THROUGH THE PERIOD AND MAY EVEN
APPROACH 15 TO 20 DEGREES BELOW NORMAL ON SATURDAY BEHIND YET
ANOTHER STRONG COLD FRONT. NORMAL HIGHS ARE RIGHT AROUND 70
DEGREES AND WE WILL BE SEEING HIGHS PRIMARILY IN THE 50S. THE BEST
CHANCE FOR PRECIPITATION WILL BE FRIDAY NIGHT INTO SATURDAY AND WILL
NEED TO KEEP AN EYE ON PRECIPITATION TYPE.
THURSDAY...A FEW VERY LIGHT RAIN SHOWERS MAY LINGER OVER FROM
WEDNESDAY NIGHT PRIMARILY DURING THE MORNING HOURS FOR AREAS EAST OF
HIGHWAY 281. THE COLD FRONT WILL HAVE ALREADY PASSED THROUGH THE
ENTIRE CWA AND EXPECT COLD AIR ADVECTION THROUGH MUCH OF THE DAY
RESULTING IN HIGHS THAT ONLY REACH INTO THE 50S.
FRIDAY...TEMPERATURES WILL REMAIN COOL AND A REINFORCING COLD FRONT
WILL BE KNOCKING AT OUR DOOR BY LATE DAY...LIKELY TO SWING THROUGH
FRIDAY NIGHT. WILL KEEP FRIDAY DRY FOR NOW...BUT THERE ARE SOME
HINTS THAT SLIGHT POPS MAY BE NEEDED FOR LATE FRIDAY AFTERNOON AS
THE COLD FRONT NEARS.
FRIDAY NIGHT INTO SATURDAY...THERE WILL BE A DECENT CHANCE OF A
LIGHT COLD RAIN FRIDAY NIGHT INTO SATURDAY BEHIND THE COLD FRONT.
TEMPERATURES LATE FRIDAY NIGHT UNTIL JUST AFTER DAWN SATURDAY
MORNING WILL ONLY BE A FEW DEGREES ABOVE FREEZING ACROSS WESTERN
ZONES AND MAY BE COLD ENOUGH FOR A FEW WET SNOW FLAKES TO MIX IN.
WILL CONTINUE TO KEEP THE FORECAST ALL RAIN FOR NOW...BUT WILL NEED
TO CLOSELY MONITOR MODEL FORECAST TRENDS IN THE COMING DAYS. THE 00Z
GEM AND 00Z ECMWF ARE THE COLDEST AND WETTEST MODEL RUNS AND FOCUS
THE BEST CHANCE OF SEEING LIGHT PRECIPITATION OVER OUR WESTERN
COUNTIES AS WELL AS ACROSS NORTHERN KANSAS. EXPECT MODELS WILL
CONTINUE TO HAVE VARYING SWINGS IN FRONTAL POSITION UNTIL WE GET A
BIT CLOSER TO THE ACTUAL ARRIVAL OF THE FRONT. THE NEW CONSALL BLEND
WAS A GOOD DEAL COOLER THAN THE PREVIOUS FORECAST FOR SATURDAY AND
GIVEN THE CURRENT MODEL TRENDS DECIDED TO LOWER SATURDAY
TEMPERATURES EVEN FURTHER. AREAS THAT SEE LITTLE TO NO SUNSHINE MAY
NOT GET OUT OF THE 40S FOR HIGHS ON SATURDAY. HOWEVER...IF WE DO SEE
A LITTLE SUN THEN EXPECT HIGHS WILL MAKE THE 50S.
SUNDAY...DRY WEATHER WILL RETURN AND TEMPERATURES SHOULD SEE SOME
SLIGHT MODERATION WITH MORE SUNSHINE...ALTHOUGH HIGHS WILL LIKELY
STILL ONLY BE IN THE MID TO UPPER 50S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...ROSSI
SHORT TERM...GUERRERO
LONG TERM...WESELY
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1246 PM CDT MON OCT 1 2012
.UPDATE...
ONGOING CONVECTION.
&&
.DISCUSSION...
QUICK UPDATE TO INCREASE POPS THROUGH CENTRAL PART OF CWA TO
ACCOUNT FOR ONGOING CONVECTION. EXPECT THIS TO CONTINUE THROUGH THE
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 1038 AM CDT MON OCT 1 2012/
UPDATE...
CONVECTION DEVELOPING NORTH CENTRAL.
DISCUSSION...
A SMALL AREA OF CONVECTION HAS DEVELOPED IS MOVING SOUTHEASTWARD
INTO KERR COUNTY. THE CURRENT RAP MODEL SHOWS CONVECTION
CONTINUING THROUGH ABOUT NOON...BUT IS MISPLACED TO THE WEST. HAVE
UPDATED POPS AND WX TO SHOW A CHANCE FOR SHOWERS AND THUNDERSTORMS
DOWN INTO MEDINA AND WESTERN BEXAR COUNTIES. WILL SEE HOW THINGS
DEVELOP OVER THE NEXT COUPLE OF HOURS FOR POSSIBLE CHANGES FOR THE
AFTERNOON. MAY NEED TO INCREASE POPS FURTHER.
PREV DISCUSSION... /ISSUED 619 AM CDT MON OCT 1 2012/
AVIATION...
AN UPPER LEVEL DISTURBANCE WILL GENERATE ISOLD SHRA/TSRA TODAY
THROUGH THIS EVENING. FOR NOW...DUE TO UNCERTAINTY ON LOCATION OF
DEVELOPMENT AND SUBSEQUENT MOVEMENT...WILL LEAVE MENTION OUT OF
TAFS. HOWEVER...ONE OR MORE TAFS MAY HAVE TO BE UPDATED TO INCLUDE
MENTION WHEN IT BECOMES MORE CERTAIN. VFR SKIES WILL PREVAIL WITH
CLOUDS ABOVE 4K FT. DAYTIME MIXING WILL CREATE N TO NW WINDS 8 TO
15 KTS WITH SOME GUSTS TO 20 KTS. DECOUPLING AND A WEAK PRESSURE
GRADIENT WILL ALLOW FOR WINDS DECREASING TO 5 KTS OR LESS TONIGHT.
PREV DISCUSSION... /ISSUED 328 AM CDT MON OCT 1 2012/
DISCUSSION...
MAIN CHANGE THIS MORNING IS TO ADD ISOLATED SHOWERS AND THUNDERSTORMS
TO THE FCST FOR TODAY AND THIS EVENING. CONVECTIVE COMPLEX OVER THE
TRANS-PECOS REGION HAS BEEN MOVING SSE OVERNIGHT AND IS ENTERING
NORTHWEST VAL VERDE COUNTY. THIS IS A HARBINGER OF THINGS TO COME
FOR TODAY. THERE IS GOOD MODEL CONSENSUS FOR ISOLATED CONVECTION
ACROSS OUR CWFA TODAY AND THIS EVENING. THIS IS DUE TO AN UPPER
LEVEL DISTURBANCE THAT IS CURRENTLY LOCATED OVER THE TEXAS PANHANDLE.
THIS FEATURE WILL MOVE SOUTHWARD ACROSS OUR CWFA ALONG THE BACKSIDE
OF THE UPPER LEVEL TROF. THE HI-RES ARW AND NMM DO A GOOD JOB
CAPTURING THIS FEATURE AND ASSOCIATED QPF. COOLER TEMPS ALOFT IN
CONJUNCTION WITH ELEVATED CLOUD BASES MEAN THAT SOME OF THE
THUNDERSTORMS TODAY THRU THIS EVENING WILL HAVE THE POTENTIAL TO
PRODUCE SMALL HAIL WITH OUTFLOW WIND GUSTS OF 30 TO 40 MPH. HIGHS
TODAY WILL RANGE FROM NEAR 80 ACROSS THE HILL COUNTRY TO UPPER 80S
SOUTHWEST.
THE UPPER LEVEL TROF WILL FINALLY MOVE OFF TO THE EAST ON TUESDAY.
THIS WILL PLACE THE BEST UPPER LEVEL FORCING ACROSS SOUTHEAST
TEXAS AS ANOTHER DISTURBANCE ROUNDS THE BASE OF THE TROF. THE
UPPER LEVEL HIGH OVER BAJA CALIFORNIA WILL BUILD EASTWARD TOWARDS
TEXAS WEDNESDAY THRU FRIDAY WHILE A WEAK COLD FRONT WASHES OUT
ACROSS NORTHERN TEXAS ON THURSDAY. THIS PATTERN WILL KEEP SOUTH
CENTRAL TEXAS RAIN-FREE THRU THE END OF THE WEEK. ANOTHER COLD
FRONT WILL ENTER THE HILL COUNTRY SATURDAY NIGHT BUT UPPER LEVEL
SUPPORT IS WEAK SO DO NOT EXPECT SIGNIFICANT RAINFALL.
THE PATTERN OF COOL NIGHTS FOLLOWED BY WARM AFTERNOONS WILL PREVAIL
TODAY THRU WEDNESDAY. WEDNESDAY NIGHT GULF MOISTURE WILL BEGIN TO
ADVECT INLAND ACROSS SOUTH CENTRAL TEXAS AS THE SFC HIGH SHIFTS
EASTWARD. THIS WILL RESULT IN MORE HUMID CONDITIONS OVERNIGHT
THURSDAY INTO THE WEEKEND. AFTERNOON HIGHS WILL ALSO SHOW A
WARMING TREND AS THE WEEK PROGRESSES WITH THE DEPARTURE OF THE
UPPER LEVEL TROF AND ARRIVAL OF WEAK RIDGING ALOFT.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 60 83 61 88 69 / 20 - 0 0 -
AUSTIN BERGSTROM INTL AIRPORT 59 82 55 87 66 / 20 - 0 0 -
NEW BRAUNFELS MUNI AIRPORT 61 83 57 88 66 / 20 - 0 0 -
BURNET MUNI AIRPORT 58 80 58 86 68 / 20 - 0 0 -
DEL RIO INTL AIRPORT 62 84 62 92 67 / 10 - 0 0 -
GEORGETOWN MUNI AIRPORT 59 81 58 86 67 / 10 - 0 0 -
HONDO MUNI AIRPORT 60 83 58 89 64 / 20 - 0 0 -
SAN MARCOS MUNI AIRPORT 60 83 57 88 66 / 20 - 0 0 -
LA GRANGE - FAYETTE REGIONAL 59 83 58 88 67 / 10 - 0 0 -
SAN ANTONIO INTL AIRPORT 61 82 60 88 67 / 20 - 0 0 -
STINSON MUNI AIRPORT 61 83 60 89 67 / 20 - 0 0 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...05
PUBLIC SERVICE/DATA COLLECTION...33