Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/03/12
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 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 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
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 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 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
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 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
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...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
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 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 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 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 STATE COLLEGE PA
817 PM EDT TUE OCT 2 2012
.SYNOPSIS...
A WEAKENING STORM SYSTEM MOVING NORTHWARD THROUGH THE OHIO VALLEY
WILL PUSH A COMPLEX FRONTAL SYSTEM THROUGH THE STATE TONIGHT AND
WEDNESDAY. HIGH PRESSURE THEN BUILDS IN FROM THE SOUTH...WITH
WARMER THAN NORMAL TEMPERATURES IN STORE FOR WEDNESDAY INTO
FRIDAY. SHOWERS AND NOTICEABLY COOLER TEMPERATURES WILL RETURN FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST RADAR SHOWS LITTLE MORE THAN SCATTERED LIGHT SHOWERS RACING
NE ACROSS THE AREA. THIS TREND TOWARD JUST A FEW SCATTERED SHOWERS
WILL CONTINUE THIS EVENING AND OVERNIGHT A THE SYSTEM TO OUR WEST
WEAKENS AND OUR UPPER HEIGHTS ACTUALLY RISE. HAVE LOWERED POPS TO
LOW CHANCE AND SLIGHT CHANCE LEVELS. HRRR SHOWS IT DRY OVER MOST
OF THE AREA THROUGH DAYLIGHT SO MAY EVEN DROP THEM FURTHER IF
CURRENT TRENDS CONTINUE.
OVERNIGHT TEMPS WON/T DIP FAR AS LOW LEVEL MOISTURE AND CLOUD
COVER KEEP THWART COOLING. MAY SEE A COUPLE OF BREAKS IN THE
CLOUDS ACROSS THE SW EARLY...BUT STRATOCU DECK WILL RE- ESTABLISH
OVERNIGHT IN LIGHT SOUTHERLY FLOW WITH POSS OF AREAS OF DRIZZLE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
STUBBORN STRATOCU DECK WILL MIX OUT BY MID/LATE MORNING ACROSS THE
WEST...BUT MAY HOLD ON LONGER IN THE EAST WITH DEEPER MOISTURE
ALONG QUICKLY WEAKENING FRONTAL BOUNDARY. KEPT JUST A MENTION OF A
SHOWER IN THE EAST WITH THIS FEATURE...BUT MAY BE OVERDOING IT.
AS SUBTROPICAL HIGH NOSES IN FROM THE SOUTH...8H TEMPS IN THE MID
TEENS COULD ALLOW THE TEMPS TO GET 10-15F ABOVE NORMAL. SFC WINDS
VEER FROM SE TO SW DURING THE DAY...WHICH IS USUALLY A GOOD
DIRECTION FOR DOWNSLOPE AND THEREFORE A BETTER CHANCE AT CLEARING
UP AT LEAST THE SERN COS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
GENERAL FLOW PATTERN
====================
THE 2 OCT 00 AND 12 UTC GLOBAL MODEL AND ENSEMBLE GUIDANCE
REMAINS IN AGREEMENT ON THE LARGE SCALE FLOW REGIME FCST ACROSS
NOAM. HIGH LATITUDE REX BLOCK IN THE NERN PAC WILL BE LESS
MIGRATORY THAN PREVIOUSLY FORECAST 24 HOURS AGO...WHICH SHOULD
ENSURE BROAD TROUGHING DOWNSTREAM OVER THE CENTRAL AND EASTERN
CONUS THROUGH THE PERIOD.
MODEL DIAGNOSTICS/PREFERENCES
=============================
CONCERNING THE MID-UPPER TROUGH WEAKENING/ACCELERATING NEWD OUT
OF THE MIDDLE MISSISSIPPI VALLEY ON D3...THE 12Z NAM IS ON THE
SLOWER/MORE AMPLIFIED SIDE OF MODEL SPREAD WITH LIFTING THE ENERGY
NORTHWARD THROUGH THE OHIO VALLEY INTO THE NORTHEAST THURSDAY.
OVERALL...THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THIS
FEATURE.
THE LAST TWO RUNS OF THE ECMWF ARE STRONGER THAN THE NAM/GFS WITH
THE SHORTWAVE ROTATING THROUGH THE NRN PLAINS/UPPER MS VLY SAT-SUN.
THIS LEADS TO UNCERTAINTY REGARDING THE PCPN PATTERN EVOLVING EWD
THROUGH THE OH VLY INTO THE MID-ATLANTIC REGION...PARTICULARLY ON
DAY 6 (SUN). A COMPROMISE SOLUTION SUPPORTS HIGH END CHC TO LOW LKLY
POPS ON DAY 5. THE ECMWF IS MORE BULLISH THAN THE GFS FOR PCPN FOR
DAY 6...AS IT DEVELOPS AN AREA OF LOW PRES OVR THE MID-ATLC
PIEDMONT.
THE MODEL DIFFS WITH THE AFOREMENTIONED SHORTWAVE IMPACT THE TRACK
OF ASSOC SURFACE CYCLONE DEEPENING OVER THE UPPER MIDWEST/GREAT
LAKES THUR-FRI...AND EWD PROGRESSION OF STRONG TRAILING COLD FRONT
PUSHING EWD THROUGH THE MIDWEST/OH VLY. A ECMWF/UKMET BLEND IS
PREFERRED HERE AS A MIDDLE OF THE ROAD SOLUTION.
THE GFS LOOKS MORE PROGRESSIVE EARLY NEXT WEEK WITH SHORTWAVE
ENERGY ROTATING WITHIN THE MEAN TROUGH OVR THE GREAT LAKES REGION.
WEATHER IMPACTS
================
LATE-WEEK WARM SPELL FOLLOWED BY SIGNIFICANT COOL DOWN INTO
EARLY NEXT WEEK...
WEAKENING SYSTEM EJECTING NEWD FROM THE MS VLY WILL ACCELERATE NEWD
THRU THE NORTHEAST STATES ON THUR...FOLLOWED BY S/W RIDGING AND SFC
HI PRES THURS NGT INTO FRI. THURS AND FRIDAY LOOK MILD AND MAINLY
DRY. FRIDAY COULD BE THE WARMEST DAY AHEAD OF A STRONG COLD FRONT
PUSHING EWD THROUGH THE MIDWEST. FRONTAL SHOWERS MAY REACH THE NW
MTNS BY THE FRI AFTN...WITH MORE ORGANIZED RAINS LKLY FRI NGT
INTO SAT AS THE WELL-DEFINED COLD FRONT SHIFTS SEWD THROUGH
CENTRAL PA. PCPN MAY CONTINUE ON SUNDAY IF THE ECMWF SOLUTION
VERIFIES.
THE MAIN WEATHER IMPACT THIS PERIOD WILL BE A SHOT OF UNSEASONABLY
COLD AIR INVADING THE REGION OVER THE WEEKEND...WITH BELOW NORMAL
TEMPS CONTINUING THROUGH EARLY NEXT WEEK. THE EARLY SEASON COOL
DOWN IS WELL-ADVERTISED AND SUPPORTED BY BELOW NORMAL 500MB
HEIGHTS AND 850MB TEMPS IN THE ENSEMBLE MEANS. THIS MIGHT LEAD TO
THE FIRST LAKE EFFECT SNOW SHOWERS OF THE SEASON OVR THE WRN
MTNS...WHICH IS NOT UNUSUAL FOR EARLY OCTOBER.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
LOW CIGS CONTINUE TO INTENSIFY AS THE EVENING CONTINUES. TODAYS
RAINFALL AND LOW CIGS HAVE COUPLED TO ALLOW FOR IFR TO LIFR
CONDITIONS ACROSS THE REGION. EXPECT THESE CONDITIONS TO CONTINUE
THROUGH MOST OF THE EVENING. BANDS OF -DZ SHOULD FORM OVER THE NW
MTNS AND THE LAURELS TONIGHT...BETWEEN 04-10Z. EXPECT THE IFR TO
LIFR CONDITIONS TO CONTINUE UNTIL MORNING...ESPECIALLY THE LOW
STRATOCU DECK. THE NOSE OF DRY AIR SHOULD ADVECT INTO THE AREA
LATE TONIGHT/EARLY MORNING...HOWEVER THIS SHOULD ONLY CEASE ANY
PRECIPITATION. EXPECT THE STUBBORN STRATOCU DECK TO REMAIN
ENTRENCHED OVER THE REGION UNTIL IT MIXES OUT BY MID/LATE MORNING
ACROSS THE WEST...BUT MAY HOLD ON LONGER IN THE EAST WITH DEEPER
MOISTURE ALONG A QUICKLY WEAKENING FRONTAL BOUNDARY. CONDITIONS
EVENTUALLY GET TO VFR AS THE DAY PROGRESSES...WITH LIGHT SOUTH/SW
WINDS...BY 18Z.
OUTLOOK...
WED...AM LOW CIGS/FOG...GRADUALLY IMPROVING CONDITIONS.
THU...AM LOW CIGS/FOG POSSIBLE EAST. OTHERWISE NO SIG WX.
FRI...NO SIG WX EXPECTED.
SAT-SUN...MAINLY VFR...MVFR LIKELY IN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...LA CORTE/RXR
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
707 PM EDT TUE OCT 2 2012
.SYNOPSIS...
A WEAKENING STORM SYSTEM MOVING NORTHWARD THROUGH THE OHIO VALLEY
WILL PUSH A COMPLEX FRONTAL SYSTEM THROUGH THE STATE TONIGHT AND
WEDNESDAY. HIGH PRESSURE THEN BUILDS IN FROM THE SOUTH...WITH
WARMER THAN NORMAL TEMPERATURES IN STORE FOR WEDNESDAY INTO
FRIDAY. SHOWERS AND NOTICEABLY COOLER TEMPERATURES WILL RETURN FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LATEST RADAR SHOWS LITTLE MORE THAN SCATTERED LIGHT SHOWERS RACING
NE ACROSS THE AREA. THIS TREND TOWARD JUST A FEW SCATTERED SHOWERS
WILL CONTINUE THIS EVENING AND OVERNIGHT A THE SYSTEM TO OUR WEST
WEAKENS AND OUR UPPER HEIGHTS ACTUALLY RISE. HAVE LOWERED POPS TO
LOW CHANCE AND SLIGHT CHANCE LEVELS. HRRR SHOWS IT DRY OVER MOST
OF THE AREA THROUGH DAYLIGHT SO MAY EVEN DROP THEM FURTHER IF
CURRENT TRENDS CONTINUE.
OVERNIGHT TEMPS WON/T DIP FAR AS LOW LEVEL MOISTURE AND CLOUD
COVER KEEP THWART COOLING. MAY SEE A COUPLE OF BREAKS IN THE
CLOUDS ACROSS THE SW EARLY...BUT STRATOCU DECK WILL RE- ESTABLISH
OVERNIGHT IN LIGHT SOUTHERLY FLOW WITH POSS OF AREAS OF DRIZZLE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
STUBBORN STRATOCU DECK WILL MIX OUT BY MID/LATE MORNING ACROSS THE
WEST...BUT MAY HOLD ON LONGER IN THE EAST WITH DEEPER MOISTURE
ALONG QUICKLY WEAKENING FRONTAL BOUNDARY. KEPT JUST A MENTION OF A
SHOWER IN THE EAST WITH THIS FEATURE...BUT MAY BE OVERDOING IT.
AS SUBTROPICAL HIGH NOSES IN FROM THE SOUTH...8H TEMPS IN THE MID
TEENS COULD ALLOW THE TEMPS TO GET 10-15F ABOVE NORMAL. SFC WINDS
VEER FROM SE TO SW DURING THE DAY...WHICH IS USUALLY A GOOD
DIRECTION FOR DOWNSLOPE AND THEREFORE A BETTER CHANCE AT CLEARING
UP AT LEAST THE SERN COS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
GENERAL FLOW PATTERN
====================
THE 2 OCT 00 AND 12 UTC GLOBAL MODEL AND ENSEMBLE GUIDANCE
REMAINS IN AGREEMENT ON THE LARGE SCALE FLOW REGIME FCST ACROSS
NOAM. HIGH LATITUDE REX BLOCK IN THE NERN PAC WILL BE LESS
MIGRATORY THAN PREVIOUSLY FORECAST 24 HOURS AGO...WHICH SHOULD
ENSURE BROAD TROUGHING DOWNSTREAM OVER THE CENTRAL AND EASTERN
CONUS THROUGH THE PERIOD.
MODEL DIAGNOSTICS/PREFERENCES
=============================
CONCERNING THE MID-UPPER TROUGH WEAKENING/ACCELERATING NEWD OUT
OF THE MIDDLE MISSISSIPPI VALLEY ON D3...THE 12Z NAM IS ON THE
SLOWER/MORE AMPLIFIED SIDE OF MODEL SPREAD WITH LIFTING THE ENERGY
NORTHWARD THROUGH THE OHIO VALLEY INTO THE NORTHEAST THURSDAY.
OVERALL...THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THIS
FEATURE.
THE LAST TWO RUNS OF THE ECMWF ARE STRONGER THAN THE NAM/GFS WITH
THE SHORTWAVE ROTATING THROUGH THE NRN PLAINS/UPPER MS VLY SAT-SUN.
THIS LEADS TO UNCERTAINTY REGARDING THE PCPN PATTERN EVOLVING EWD
THROUGH THE OH VLY INTO THE MID-ATLANTIC REGION...PARTICULARLY ON
DAY 6 (SUN). A COMPROMISE SOLUTION SUPPORTS HIGH END CHC TO LOW LKLY
POPS ON DAY 5. THE ECMWF IS MORE BULLISH THAN THE GFS FOR PCPN FOR
DAY 6...AS IT DEVELOPS AN AREA OF LOW PRES OVR THE MID-ATLC
PIEDMONT.
THE MODEL DIFFS WITH THE AFOREMENTIONED SHORTWAVE IMPACT THE TRACK
OF ASSOC SURFACE CYCLONE DEEPENING OVER THE UPPER MIDWEST/GREAT
LAKES THUR-FRI...AND EWD PROGRESSION OF STRONG TRAILING COLD FRONT
PUSHING EWD THROUGH THE MIDWEST/OH VLY. A ECMWF/UKMET BLEND IS
PREFERRED HERE AS A MIDDLE OF THE ROAD SOLUTION.
THE GFS LOOKS MORE PROGRESSIVE EARLY NEXT WEEK WITH SHORTWAVE
ENERGY ROTATING WITHIN THE MEAN TROUGH OVR THE GREAT LAKES REGION.
WEATHER IMPACTS
================
LATE-WEEK WARM SPELL FOLLOWED BY SIGNIFICANT COOL DOWN INTO
EARLY NEXT WEEK...
WEAKENING SYSTEM EJECTING NEWD FROM THE MS VLY WILL ACCELERATE NEWD
THRU THE NORTHEAST STATES ON THUR...FOLLOWED BY S/W RIDGING AND SFC
HI PRES THURS NGT INTO FRI. THURS AND FRIDAY LOOK MILD AND MAINLY
DRY. FRIDAY COULD BE THE WARMEST DAY AHEAD OF A STRONG COLD FRONT
PUSHING EWD THROUGH THE MIDWEST. FRONTAL SHOWERS MAY REACH THE NW
MTNS BY THE FRI AFTN...WITH MORE ORGANIZED RAINS LKLY FRI NGT
INTO SAT AS THE WELL-DEFINED COLD FRONT SHIFTS SEWD THROUGH
CENTRAL PA. PCPN MAY CONTINUE ON SUNDAY IF THE ECMWF SOLUTION
VERIFIES.
THE MAIN WEATHER IMPACT THIS PERIOD WILL BE A SHOT OF UNSEASONABLY
COLD AIR INVADING THE REGION OVER THE WEEKEND...WITH BELOW NORMAL
TEMPS CONTINUING THROUGH EARLY NEXT WEEK. THE EARLY SEASON COOL
DOWN IS WELL-ADVERTISED AND SUPPORTED BY BELOW NORMAL 500MB
HEIGHTS AND 850MB TEMPS IN THE ENSEMBLE MEANS. THIS MIGHT LEAD TO
THE FIRST LAKE EFFECT SNOW SHOWERS OF THE SEASON OVR THE WRN
MTNS...WHICH IS NOT UNUSUAL FOR EARLY OCTOBER.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
SCATTERED LINGERING PRECIPITATION CONTINUES TO PROPAGATE THROUGH
CENTRAL AND SOUTHEASTERN PA EARLY THIS EVENING. EXPECT THESE
SHOWERS TO CONTINUE THROUGH MID EVENING BEFORE DRY AIR ADVECTS IN
BY MIDNIGHT. LOW CIGS REMAIN IN PLACE THOUGH WITH WIDESPREAD
MVFR/IFR CONDITIONS. CIGS MAY POP UP IN THE SW FOR A BIT LATE THIS
AFTERNOON AS DRY SLOT NOSES INTO W PA...BUT STRATOCU DECK WILL RE-
ESTABLISH ITSELF ACROSS THE REGION OVERNIGHT IN LIGHT SOUTHERLY
FLOW WITH POSS OF VERY LIGHT SHOWERS AND/OR AREAS OF DRIZZLE. SO
WIDESPREAD IFR CONDITIONS EXPECTED OVERNIGHT.
STUBBORN STRATOCU DECK WILL MIX OUT BY MID/LATE MORNING ACROSS THE
WEST...BUT MAY HOLD ON LONGER IN THE EAST WITH DEEPER MOISTURE
ALONG QUICKLY WEAKENING FRONTAL BOUNDARY. CONDITIONS EVENTUALLY
GET TO VFR AS THE DAY PROGRESSES...WITH LIGHT SOUTH/SW WINDS.
OUTLOOK...
WED...AM LOW CIGS/FOG...GRADUALLY IMPROVING CONDITIONS.
THU...AM LOW CIGS/FOG POSSIBLE EAST. OTHERWISE NO SIG WX.
FRI...NO SIG WX EXPECTED.
SAT-SUN...MAINLY VFR...MVFR LIKELY IN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...LA CORTE/RXR
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...CERU/RXR
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
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 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 SPOKANE WA
531 PM PDT Tue Oct 2 2012
.SYNOPSIS...
A strong cold front will bring breezy to locally windy conditions
through this evening then decreasing overnight into Wednesday. These
gusty north winds will result in areas of blowing dust for central
Washington and heighten the fire danger for much of the Inland
Northwest. The second half of the week will be cooler than
average. Some parts of northeast Washington and north Idaho may
experience a hard freeze by early Thursday morning. The dry and
cool weather will continue into the weekend.
&&
.DISCUSSION...
Quick update to this evenings forecast. Radar clearly shows the
cold front moving into the northern Palouse at the moment.
Meanwhile the 3.9 micron satellite imagery has done a great job of
showing the dust cloud spreading southward from the Okanogan
Valley into the western Columbia Basin. Web cams have shown
blowing dust reducing visibilities to less than 1 mile at times.
Have issued a blowing dust advisory for most of the Basin and
Palouse this evening. Will probably have to update this to add the
Pomeroy area.
Meanwhile a few showers are clipping the northern Panhandle. Web
cams and surface observations don`t show any rain reaching the
valleys, but some of these showers are likely reaching the higher
mountains. HRRR model shows that this activity should only last a
few hours. Updated the snow levels, lowering them to around 4000
feet for the northern Panhandle. RJ
&&
.AVIATION...
00Z TAFS...A strong cold front is moving south across the region
this evening. At 2330Z, this front has just passed through
Spokane/Coeur d`Alene Area and through the Moses Lake Area. This
front has kicked up a dust cloud with visibilities down to between 3
to 6 miles and locally down to 1 mile near tilled soils. The front
is expected to reach KPUW and KLWS between 0200-0300Z this evening
with winds shifting out of the north-northwest and MVFR visibilities
possible due to the blowing dust. Winds will shift to out of the
northeast overnight (except at KEAT, which will back to the
northwest), but should become less gusty as the surface decouples
from the free atmosphere above. Weaker winds overnight should allow dust
to settle with improving visibilities into the early morning hours.
/SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 37 60 32 59 34 59 / 0 0 0 0 0 0
Coeur d`Alene 36 60 31 59 31 59 / 10 0 0 0 0 0
Pullman 35 60 30 58 29 58 / 0 0 0 0 0 0
Lewiston 41 66 38 65 38 65 / 0 0 0 0 0 0
Colville 32 65 30 64 29 64 / 10 0 0 0 0 0
Sandpoint 38 58 30 56 30 58 / 10 0 0 0 0 0
Kellogg 34 53 30 57 32 57 / 10 0 0 0 0 0
Moses Lake 40 67 33 65 33 65 / 0 0 0 0 0 0
Wenatchee 45 65 37 65 41 65 / 0 0 0 0 0 0
Omak 37 67 31 66 34 66 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning until 10 PM PDT this evening for Northern and
Central Idaho Panhandle (Zone 101).
WA...Red Flag Warning until 10 PM PDT this evening for East
Washington Northeast (Zone 686)-East Washington Northern
Columbia Basin (Zone 673)-East Washington Okanogan
Highlands (Zone 687)-East Washington Okanogan/Methow
Valleys (Zone 684).
Blowing Dust Advisory until 11 PM PDT this evening for Moses
Lake Area-Spokane Area-Upper Columbia Basin-Washington
Palouse.
Red Flag Warning until 8 PM PDT this evening for East Washington
Central Cascade Mountains (Zone 682)-East Washington
Central Cascade Valleys (Zone 677)-East Washington North
Cascades (Zone 685)-East Washington South Central Cascade
Mountains (Zone 680)-East Washington South Central Cascade
Valleys (Zone 676).
AIR QUALITY ALERT until Noon PDT Thursday for East Slopes
Northern Cascades-Okanogan Valley-Waterville Plateau-
Wenatchee Area.
Wind Advisory until 8 PM PDT this evening for Okanogan Valley-
Waterville Plateau.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
626 PM CDT TUE OCT 2 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY
312 PM CDT TUE OCT 2 2012
THE MAIN FOCUS THROUGH THE REST OF THE WEEK IS WITH A POTENT COLD
FRONT THAT WILL MOVE ACROSS THE REGION EARLY ON THURSDAY AND BRING
AN END TO THIS FIRST RUN OF INDIAN SUMMER.
ANOTHER DAY OF PLEASANT AND DRY CONDITIONS ACROSS THE REGION TODAY
AS WE REMAIN SANDWICHED IN BETWEEN TWO LOW PRESSURE SYSTEMS WITH
HIGH PRESSURE IN BETWEEN OVER THE UPPER MISSISSIPPI VALLEY FROM
THE SURFACE THROUGH THE UPPER LEVELS OF THE ATMOSPHERE. THIS RIDGE
AXIS WILL SLOWLY DRIFT TO THE EAST TONIGHT INTO TOMORROW AS THE
MID LEVEL TROUGH TO THE SOUTHEAST AND THE OTHER TROUGH OVER SOUTH
CENTRAL CANADA MAKE SOME SLOW PROGRESS EASTWARD. WITH THE CORE OF
THE RIDGE OVERHEAD FOR MUCH OF THE OVERNIGHT PERIOD...SKIES WILL
BE CLEAR WITH WINDS LIGHT FROM THE SURFACE ON UP THROUGH 15KFT.
THIS SETUP SHOULD PRODUCE SOME RADIATIONAL FOG THAT FORMS IN LOW
SPOTS AND VALLEYS...PARTICULARLY ACROSS WESTERN WISCONSIN. LOW
LEVEL WINDS AROUND 925MB DO PICK UP TOWARD DAYBREAK ACROSS
SOUTHEAST MINNESOTA...BUT ARE STILL LIGHT ENOUGH AT 10KTS THAT
SOME RIVER VALLEY FOG SHOULD FORM.
THE WARMEST DAY OF THE WEEK WILL BE ON WEDNESDAY AS THE TROUGH
OVER THE NORTHERN PLAINS BECOMES MORE NEGATIVELY TILTED AND A
DEEPENING SURFACE LOW FORMS IN SOUTHEAST SOUTH DAKOTA WITH SURFACE
WINDS INCREASING OUT OF THE SOUTH ACROSS THE REGION. THE CORE OF
THE WARMEST LOW LEVEL AIR REMAINS OFF TO THE WEST...BUT WITH FULL
SUNSHINE AND SOUTHERLY WINDS SURFACE TEMPERATURES SHOULD BE ABLE
TO CLIMB UP INTO THE UPPER 70S TO AROUND 80. THIS SETUP MAY LEAD
TO SOME FIRE WEATHER CONCERNS WHICH ARE OUTLINED IN THE FIRE
WEATHER SECTION IN THIS AFD DOWN BELOW.
THE MAIN FORECAST CHALLENGE IS WITH THE TIMING OF THE COLD FRONT
PASSAGE ALONG WITH HOW LIKELY IT WILL BE THAT IT WILL RAIN AS THE
FRONT COMES THROUGH. THERE IS NOT A LOT OF CONSISTENCY AMONGST THE
02.12Z GUIDANCE WEDNESDAY NIGHT INTO THURSDAY WITH THE COLD FRONT
AND LOW PRESSURE SYSTEM AS IT MOVES THROUGH THE REGION. THE 02.12Z
NAM AND GFS ARE THE FASTEST WITH THE COLD FRONT REACHING EASTERN
WISCONSIN BY 18Z THURSDAY...THOUGH THE NAM SHOWS A MUCH MORE
OCCLUDED LOW TO THE NORTH ON THURSDAY. THE CONCERNING PART OF
THE LAST FEW MODEL RUNS HAS BEEN THE TREND TOWARD GOING WITH A
DRIER SOLUTION DESPITE THE STRONG DYNAMIC FORCING. GIVEN THE
LATEST TRENDS...IT APPEARS THAT THE BETTER CHANCES FOR THE
CROSSOVER IN FORCING AND MOISTURE WILL BE ACROSS NORTHEAST IOWA
INTO FAR SOUTHEAST MINNESOTA AND WESTERN WISCONSIN THURSDAY
MORNING ALONG AND JUST BEHIND THE FRONTAL PASSAGE. INSTABILITY
LOOKS MARGINAL AT BEST...BUT SOME OF THE CONVECTIVE MODELS DO SHOW
SOME STORMS DEVELOPING AS THE FRONT COMES THROUGH...SO HAVE LEFT
SOME ISOLATED THUNDER MENTION IN ON THURSDAY MORNING. COLD AIR
WILL QUICKLY MOVE IN ACROSS THE REGION WITH HIGH TEMPERATURES
LIKELY COMING IN THE EARLY MORNING HOURS BEFORE DROPPING OR
STABILIZING THROUGH THE REST OF THE DAY. WINDS WILL ALSO BECOME
GUSTY UP TO 25-30KTS THROUGH THE REST OF THE AFTERNOON AS THE DRY
SLOT MOVES IN WHICH WILL HELP TO LIKELY END THE COLORFUL FOLIAGE
THAT HAS BEEN PRESENT THROUGH MUCH OF THE REGION OVER THE PAST FEW
WEEKS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
312 PM CDT TUE OCT 2 2012
NOT MUCH CONFIDENCE IN THE EXTENDED PERIOD FROM THE WEEKEND INTO
EARLY NEXT WEEK AS THE 02.12Z GFS PUSHES FOR A COLDER SOLUTION
WITH A SYSTEM DROPPING THROUGH THE REGION ON MONDAY WHILE THE
02.12Z ECMWF IS WARMER AFTER THE INITIAL COLD SURGE GOING INTO
MONDAY AND TUESDAY AND LINGERS SOME PRECIPITATION ALONG THE
INVERTED TROUGH THIS WEEKEND. THERE AT LEAST IS AGREEMENT THAT
TEMPERATURES WILL STAY BELOW NORMAL THROUGH THE WEEKEND WITH 850MB
TEMPERATURES DROPPING DOWN TO -6C FRIDAY THROUGH SUNDAY BEFORE LOW
LEVEL WARM AIR ADVECTION KICKS BACK IN SUNDAY NIGHT. BEYOND
THAT...THE 02.12Z GFS ADVECTS COLDER AIR BACK IN WHILE THE 02.12Z
ECMWF STRONGLY ADVECTS WARMER AIR IN FROM THE SOUTHWEST. THE GFS
HAS AT LEAST HAD SOME CONSISTENCY TO IT WITH THE MONDAY
SYSTEM...SO FEEL A LITTLE STRONGER TOWARD GOING IN THAT DIRECTION
FOR NOW WITH KEEPING THE COOLER AIR AROUND INTO NEXT WEEK.
PRECIPITATION TYPES COULD BE AN ISSUE...BUT ITS RATHER BORDERLINE
RIGHT NOW FOR WHETHER IT WOULD BE COLD ENOUGH TO SUPPORT A MIX OF
RAIN/SNOW. THE INVERTED SURFACE TROUGH WILL HAVE TO BE WATCHED
THIS WEEKEND AS WELL FOR PRECIPITATION CHANCES IF THE HIGH DOES
NOT BUILD IN AS STRONGLY AS THE GFS IS FORECASTING.
&&
.AVIATION...TONIGHT AND WEDNESDAY
626 PM CDT TUE OCT 2 2012
MAIN CONCERN IS VALLEY FOG POTENTIAL LATE TONIGHT EARLY WEDNESDAY
MORNING AT KLSE. OUTSIDE OF THIS VFR CONDITIONS EXPECTED. WITH
HIGH PRESSURE OVERHEAD...CLEAR SKIES AND LIGHTER WINDS EXPECTED
OVERNIGHT SETTING UP IDEAL RADIATIONAL FOG CONDITIONS. THE ONE CAVEAT
IS BUFKIT SOUNDINGS FROM THE 02.21Z RAP AND 02.18Z NAM SHOWING
INCREASING LOW LEVEL WINDS LATE TONIGHT. WILL LIKELY BE SOME FOG
IN THE MISSISSIPPI RIVER VALLEY TONIGHT...BUT WITH THIS INCREASE
IN WIND WILL LIKELY SEE IT MORE PATCHY IN NATURE. FOR NOW WILL
CONTINUE THE BCFG WITH A SCATTERED DECK AT 300 FEET AND WILL WATCH
MODEL TRENDS THIS EVENING FOR ANY POTENTIAL RESTRICTIONS TO
VISIBILITIES.
&&
.FIRE WEATHER...WEDNESDAY
312 PM CDT TUE OCT 2 2012
DRY CONDITIONS COUPLED WITH SOME GUSTY WINDS OF 15-20 MPH MAY LEAD
TO SOME NEAR CRITICAL FIRE WEATHER CONCERNS ACROSS PORTIONS OF
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. A LOW PRESSURE SYSTEM
WILL MOVE ACROSS THE DAKOTAS AND MINNESOTA TOMORROW WITH WARM AND
DRY SOUTHERLY WINDS IN PLACE AHEAD OF THIS SYSTEM. RELATIVE
HUMIDITIES ARE FORECAST TO DROP INTO THE 20-30 PERCENT RANGE IN
THE AFTERNOON ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA THOUGH
WINDS WILL BE TOO LOW AT 10-20MPH TO SUPPORT RED FLAG CONDITIONS.
GIVEN THE DRY CONDITIONS ALREADY IN PLACE AND THE FACT THAT A LOT
OF VEGETATION IS LIKELY DEAD TO DO A KILLING FREEZE LAST
WEEK...FIRE WEATHER CONDITIONS ARE EXPECTED TO BE NEAR
CRITICAL. DUE TO THE LIGHT WINDS...NO FIRE WEATHER WATCHES OR RED
FLAG WARNINGS WILL BE ISSUED AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
312 PM CDT TUE OCT 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
FIRE WEATHER...HALBACH
AREA FORECAST DISCUSSION
NWS 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 NEW YORK NY
228 AM EDT WED OCT 3 2012
.SYNOPSIS...
A WARM FRONT WILL REMAIN JUST SOUTH OF THE AREA THROUGH WEDNESDAY
BEFORE DISSIPATING AND GIVING WAY TO A COLD FRONTAL PASSAGE ON
THURSDAY. HIGH PRESSURE THEN BUILDS TO OUR SOUTH THROUGH FRIDAY
NIGHT. A STRONGER COLD FRONT WILL MOVE ACROSS THE REGION THIS
WEEKEND WITH A DRY BUT UNSEASONABLY COOL AIR MASS TO FOLLOW NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
PATCHY DRIZZLE WITH AREAS OF FOG WILL BE THE MAIN WEATHER FEATURES
WITHOUT MUCH ADDITIONAL LOWERING OF TEMPERATURE OVERNIGHT INTO
EARLY WEDNESDAY MORNING. WARM FRONT SOUTH OF LONG ISLAND SHOWN BY
SOME FORECAST MODELS SUCH AS RUC AND NAM TO GO INTO EASTERN LONG
ISLAND AS DIAGNOSED FROM LOW LEVEL INCREASES OF DEWPOINTS AND
DECREASE IN LIFTED INDEX.
A LIGHT FLOW OVERNIGHT. THE LIGHT FLOW AND SATURATED LOW LEVELS
SHOULD ALSO ALLOW FOR AREAS OF FOG. SOME OF THIS FOG IS EXPECTED
TO BECOME LOCALLY DENSE AT TIMES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
EARLY MORNING FOG/DRIZZLE ON WED WILL GIVE WAY TO WIDELY SCATTERED
SHOWERS IN THE AFTERNOON...WITH THE POSSIBILITY OF AN ISOLATED
THUNDERSTORM NW OF NYC. MARGINAL INSTABILITY IS FORECAST AS
SURFACE DEW POINTS APPROACH 70. THE WARM FRONT WILL BE IN CLOSE
PROXIMITY..BUT FOR THE TIME WILL KEEP WINDS NE IN THE MORNING AND
THEN VEER THEM AROUND TO THE E/SE IN THE AFT. THE NAM WRF BRINGS
THE WARM FRONT ACROSS THE AREA TUE NIGHT AND KEEPS IT JUST NORTH
THROUGH ON WED. CONFIDENCE IS LOW IN THIS SCENARIO AND STAYED
WITH THE MODEL SUITE WHICH SUPPORTED THE GFS AND THE FARTHER SOUTH
SOLUTION.
WITH THE CLOSE PROXIMITY OF THE WARM FRONT WED/WED NIGHT...THERE
SHOULD BE PLENTY OF CLOUD COVER WITH WARM...MUGGY CONDITIONS.
PREFERRED THE SLIGHTLY COOLER MAV GUIDANCE...WITH HIGHS MID 70S
TO AROUND 80. THIS IS STILL WELL ABOVE NORMAL. NORMAL HIGHS ARE
AROUND 70.
THE UPPER FLOW FEATURES A HIGH AMPLITUDE RIDGE JUST OFF THE EAST
COAST...AND A DEEP TROUGH OVER THE LOWER MS VLY. THUS...THE
UNUSUAL WARMTH AND HUMIDITY.
EXPECT ANOTHER FOGGY NIGHT WED NIGHT WITH LIGHT ONSHORE WINDS AND
SATURATED LOW-LEVELS. THERE IS THE POTENTIAL FOR DENSE FOG.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE PERIOD STARTS WITH UNCERTAINTY OF WHERE THE SFC WARM FRONT WILL
BE THU MORNING. HAVE CONTINUED WITH A NON-NAM SOLN...KEEPING THE
BOUNDARY TO OUR S WITH A WAVE OF LOW PRES PASSING OVER OR JUST S OF
THE FORECAST AREA. RAIN WITH MUGGY CONDS AND AREAS OF FOG IN THE
MORNING WILL GRADUALLY GIVE WAY TO IMPROVING CONDS LATER IN THE
DAY AS THE LOW AND UPPER SHORTWAVE SLOWLY LIFTS TO THE NE AND HIGH
PRES BUILDS IN BEHIND IT.
UPPER PATTERN IS IN GOOD AGREEMENT ACROSS THE LOWER 48 THROUGH
FRI...WITH A NEARLY ZONAL FLOW WEST OF THE ROCKIES. PROBLEMS BEGIN
TO ARISE WITH THE NEXT LONGWAVE TROUGH DIGGING FROM THE PACIFIC NW
TO THE CENTRAL PLAINS THIS WEEKEND WITH LARGER DIFFERENCES IN
SHORTWAVE ENERGY ONCE IT MAKES IT TO THE NORTHEAST. THIS HAS
RESULTED IN DECREASED CONFIDENCE IN EXACT TIMING OF
PRECIPITATION...ESPECIALLY ON SAT AHEAD OF AND WITH COLD FROPA.
UPPER ENERGY AND LIFT IS LAGGING AND BOTH THE GFS AND EC ARE HINTING
AT MID ATLANTIC COASTAL LOW DEVELOPMENT AND INCREASING
FRONTOGENETIC FORCING DURING THE SAT NIGHT/SUN TIME PERIOD. SINCE
THE TIMING OF THE UPPER FEATURES ARE IN QUESTION...HAVE USED A
COMPROMISE OF THE UKMET/EC/GFS FOR THE WEEKEND AND ALTHOUGH THERE IS
A LONG DURATION OF POPS THIS WEEKEND...DON`T THINK IT WILL BE A
COMPLETE WASHOUT.
TEMPERATURES ARE EXPECTED TO BE ABOVE NORMAL THU AND FRI AND NEAR
NORMAL ON SAT WITH CLOUD COVER AND POSSIBLE SHOWERS. BEHIND THE
FRONT...IT WILL BE DRY BUT UNSEASONABLY COOL INTO EARLY NEXT
WEEK...WITH H85 TEMPS DROPPING TO NEAR 0C AND DAYTIME HIGHS
GENERALLY IN THE UPPER 50S TO LOWER 60S AND LOWS GENERALLY IN THE
40S...WHICH IS AROUND 10 DEGREES BELOW NORMAL FOR EARLY FALL.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A WARM FRONT WILL REMAIN JUST SOUTH OF NYC AND LONG ISLAND
OVERNIGHT. BASED ON A WEAK WAVE EXPECTED TO MOVE SOUTH OF THE AREA
THROUGH DAYBREAK...THE EXPECTATION IS FOR THE WARM FRONT TO STAY
SOUTH OF THE TERMINALS TODAY INTO TONIGHT.
BASED ON ABOVE THINKING...LIFR/VLIFR CONDS IN -DZ THIS MORNING ARE
ONLY EXPECTED TO SLOWLY IMPROVE AFTER DAYBREAK. UNCERTAINTY EXISTS
TO WHAT EXTENT IMPROVEMENT OCCURS. DIURNAL HEATING SHOULD ALLOW
VSBY TO IMPROVE AS -DZ BECOMES MORE PATCHY. MODERATE CONFIDENCE
EXISTS IN IMPROVEMENT TO MVFR...OR POSSIBLY VFR ACROSS CITY
TERMINALS...THIS AFTERNOON.
IN TERMS OF CIGS...CONFIDENCE IS MODERATE IN MOIST LOW- LEVELS
UNDER A WEAK INVERSION ONLY ALLOWING IMPROVEMENT TO IFR OR LOW-
END MVFR. HIGHER CONFIDENCE IN IFR FOR EASTERN AND NORTHERN
TERMINALS...WITH MVFR FOR THE NYC/NJ TERMINALS.
IFR CONDS ARE LIKELY TO RETURN TOWARDS EVENING WITH
LIGHT ONSHORE WINDS AND ABUNDANT MOISTURE...WITH VLIFR CONDS
POSSIBLE AT THE COAST. INCREASING LIKELIHOOD FOR -DZ OR -SHRA
AHEAD OF NEXT WAVE TONIGHT.
LIGHT N/NE WINDS THIS MORNING...LIKELY BECOME SE THIS
AFTERNOON/EVENING AHEAD OF DEVELOPING LOW PRESSURE WAVE TO THE
SOUTH. LIGHT E/SE WINDS EXPECTED TONIGHT.
OUTLOOK FOR 06Z THU-SUNDAY...
.LATE TONIGHT...LIFR CONDS...POSSIBLY VLIFR...EXPECTED IN FOG AND
LOW STRATUS.
.THU...MORNING IFR/MVFR EXPECTED. IMPROVEMENT TO VFR POSSIBLE
BY AFTERNOON.
.THU NIGHT-FRI NIGHT...VFR.
.SAT...VFR...POSSIBLY LOWER IN SCT SHOWERS.
.SUN...VFR.
&&
.MARINE...
EXPECTING TRANQUIL CONDITIONS ON THE COASTAL WATERS WITH WEAK
PRESSURE GRADIENTS IN PLACE WITH SUB SCA CONDITIONS FORECAST THROUGH
WEDNESDAY NIGHT.
SCA CONDS ARE POSSIBLE BEHIND A STRONG COLD FRONTAL PASSAGE THIS
WEEKEND. OTHERWISE...TRANQUIL CONDITIONS ARE EXPECTED ON THE WATERS.
&&
.HYDROLOGY...
AN UPDATED RAINFALL GRAPHIC HAS BEEN POSTED INDICATING AMOUNTS
EXPECTED FOR THE REMAINDER OF THE NIGHT. IN GENERAL...A FEW
HUNDREDTHS IN THE CITY AND W...WITH A FEW TENTHS OUT E. LOCALLY
HIGHER AMOUNTS POSSIBLE ON LI IF THE WARM FRONT GETS CLOSER THAN
CURRENTLY FCST...BUT THE PROB IS LOW ATTM.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...24/DW
NEAR TERM...JMC/DW/JM
SHORT TERM...DW
LONG TERM...24
AVIATION...NV
MARINE...24/DW
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
420 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT NORTHEAST WINDS BECOMING VARIABLE THROUGH MUCH OF THE
MORNING.
* MVFR CEILINGS LOWERING TO IFR CEILINGS BY 12/13Z THIS
MORNING...AND LINGERING THROUGH THE REMAINDER OF THE MORNING.
* LIGHT SHOWERS/FOG MOVING ACROSS THE TERMINALS THIS MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 09Z...
HAVE MADE SIGNIFICANT CHANGES TO THE TAF WITH THIS UPDATE...GOING
MORE PESSIMISTIC WITH THE CEILINGS THIS MORNING. GOOD SWATH OF
MVFR/IFR CEILINGS CURRENTLY RESIDE JUST SOUTH OF THE TERMINALS AND
AS THIS WEAK LOW CONTINUES NORTH...DONT SEE ANY REASON WHY THESE
LOW CEILINGS WONT MOVE OVERHEAD. SO HAVE STARTED THE TAFS WITH
MVFR CEILINGS BUT HAVE CONDITIONS QUICKLY DETERIORATING TO IFR
CEILINGS AROUND THE 12/13Z TIME FRAME. EXPECT THESE LOW CLOUDS TO
LINGER THROUGH THE REMAINDER OF THE MORNING...BEFORE SLOWLY
LIFTING THIS AFTERNOON.
LIGHT NORTHEAST WINDS WILL PERSIST BEFORE BECOMING MORE VARIABLE
AS THE WEAKENING LOW CENTER MOVES OVERHEAD. THEN A RETURN TO LIGHT
SOUTHERLY WINDS WILL BE OBSERVED LATER THIS AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE WITH CEILING TRENDS AS WELL AS IFR TIMING
THROUGH THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWER/FOG TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE SHOWERS...SLIGHT CHANCE TS.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TRS
&&
.MARINE...
215 PM CDT
A WEAK RIDGE LIES JUST TO THE WEST OF LAKE MICHIGAN WHILE AN AREA
OF LOW PRESSURE IS LIFTING NORTH ACROSS THE MID TO UPPER OHIO
RIVER VALLEY THIS AFTERNOON. A MODEST GRADIENT IS IN PLACE OVER
FAR SOUTHERN LAKE MICHIGAN ALLOWING NORTHEASTERLY WINDS TO FRESHEN
UP SOME THIS AFTERNOON...BUT THE GRADIENT WILL WEAKEN THROUGH
THE EVENING AND OVERNIGHT AS THE LOW SLOWLY FILLS. TO OUR
WEST...LOW PRESSURE WILL BEGIN TO TAKE SHAPE OVER THE CENTRAL
PLAINS WEDNESDAY...AND DEEPEN AS IT LIFTS NORTHEAST INTO THE UPPER
MIDWEST WEDNESDAY NIGHT INTO THURSDAY. THERE IS CONSIDERABLE
SPREAD IN THE DIFFERENT MODELS SOLUTIONS REGARDING THE POSITION OF
THE LOW BY THURSDAY MORNING LEADING TO A LOW DEGREE OF CONFIDENCE
IN DETAILS OF THE FORECAST. IN GENERAL THOUGH...EXPECT
SOUTHWESTERLY WINDS TO INCREASE THROUGH THE DAY THURSDAY. WINDS
MAY BE SOMEWHAT TEMPERED BY STABLE CONDITIONS CREATED BY THE WARM
ADVECTION...BUT STILL THINK THAT WINDS MAY INCREASE TO AROUND 30
KT. A COLD FRONT WILL SWEEP ACROSS THE LAKE AS EARLY AS THURSDAY
AFTERNOON...BUT MORE LIKELY THURSDAY NIGHT AS THE LOW TRACKS OVER
THE NORTHERN GREAT LAKES REGION. COLD ADVECTION WILL ALLOW FOR
WINDS TO MIX TO THE LAKE SURFACE AND A STRONG
GRADIENT...PARTICULARLY OVER THE NORTHERN PORTIONS OF THE
LAKE...WILL ALLOW WINDS TO INCREASE TO GALE FORCE. A GALE WATCH
MAY BE ISSUED WHEN MODEL GUIDANCE COMES INTO BETTER AGREEMENT.
HIGH PRESSURE WILL GRADUALLY BUILD WEST OF THE GREAT LAKES THIS
WEEKEND...SINKING SOUTHEAST ACROSS THE MID MISSISSIPPI RIVER
VALLEY LATE THIS WEEKEND...AND KEEPING LAKE MICHIGAN IN AT LEAST A
MODERATE GRADIENT AND PROPPING UP WINDS. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
259 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 25 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIGHT NORTHEAST WINDS BECOMING VARIABLE THROUGH MUCH OF THE
MORNING.
* VFR CEILINGS SLOWLY LOWERING TO MVFR CEILINGS BY 10/11Z THIS
MORNING...AND LINGERING INTO THE AFTERNOON.
* LIGHT SHOWERS/FOG MOVING ACROSS THE TERMINALS LATER THIS
MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
WITH A SLOWLY MOVING AREA OF LOW PRESSURE JUST TO THE SOUTH OF THE
TERMINALS THIS MORNING...LOWER CLOUD COVER FINALLY WORKING ITS WAY
NEAR THE TERMINALS. DESPITE THIS LOW PRESSURE WEAKENING AS IT
MOVES OVERHEAD THIS MORNING...VFR CEILINGS SHOULD LOWER TO HIGH
END MVFR CEILINGS. HAVE CEILINGS LOWERING TO 2500FT BY THE 10/11Z
TIME FRAME THIS MORNING WITH SOME SLIGHT LOWERING TO 2000FT BY MID
MORNING. ALTHOUGH LOWER CEILINGS ARE CURRENTLY BEING OBSERVED
CLOSER TO THE LOW CENTER...STILL AM NOT QUITE CONFIDENT HOW LOW
THE CEILINGS COULD GO ONCE THIS LOW PRESSURE REACHES THE
TERMINALS. AT THIS POINT...A LOWER END POSSIBILITY WOULD BE AROUND
THE 1500FT RANGE BUT WILL NEED TO CONTINUE TO MONITOR TRENDS AND
ADJUST AS NEEDED. LIGHT SHOWERS SHOULD FINALLY MOVE ACROSS THE
TERMINALS BY MID TO LATE MORNING AND CONTINUING INTO THE EARLY
AFTERNOON. ALTHOUGH...AM NOT OVERLY CONCERNED WITH ANY REAL VIS
RESTRICTION WITH THESE SHOWERS...BUT RATHER WILL WATCH FOG TRENDS
AS THIS COULD PLAY A ROLE WITH SOME POSSIBLE LOWER VIS
RESTRICTIONS.
LIGHT NORTHEAST WINDS WILL PERSIST OVER THE NEXT SEVERAL HOURS
BEFORE BECOMING MORE VARIABLE AS THIS WEAKENING LOW CENTER MOVES
OVERHEAD. THEN A RETURN TO LIGHT SOUTHERLY WINDS WILL BE OBSERVED
LATER THIS AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE WITH CEILING TRENDS AS WELL AS MVFR TIMING
THROUGH THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWER/FOG TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE SHOWERS...SLIGHT CHANCE TS.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TRS
&&
.MARINE...
215 PM CDT
A WEAK RIDGE LIES JUST TO THE WEST OF LAKE MICHIGAN WHILE AN AREA
OF LOW PRESSURE IS LIFTING NORTH ACROSS THE MID TO UPPER OHIO
RIVER VALLEY THIS AFTERNOON. A MODEST GRADIENT IS IN PLACE OVER
FAR SOUTHERN LAKE MICHIGAN ALLOWING NORTHEASTERLY WINDS TO FRESHEN
UP SOME THIS AFTERNOON...BUT THE GRADIENT WILL WEAKEN THROUGH
THE EVENING AND OVERNIGHT AS THE LOW SLOWLY FILLS. TO OUR
WEST...LOW PRESSURE WILL BEGIN TO TAKE SHAPE OVER THE CENTRAL
PLAINS WEDNESDAY...AND DEEPEN AS IT LIFTS NORTHEAST INTO THE UPPER
MIDWEST WEDNESDAY NIGHT INTO THURSDAY. THERE IS CONSIDERABLE
SPREAD IN THE DIFFERENT MODELS SOLUTIONS REGARDING THE POSITION OF
THE LOW BY THURSDAY MORNING LEADING TO A LOW DEGREE OF CONFIDENCE
IN DETAILS OF THE FORECAST. IN GENERAL THOUGH...EXPECT
SOUTHWESTERLY WINDS TO INCREASE THROUGH THE DAY THURSDAY. WINDS
MAY BE SOMEWHAT TEMPERED BY STABLE CONDITIONS CREATED BY THE WARM
ADVECTION...BUT STILL THINK THAT WINDS MAY INCREASE TO AROUND 30
KT. A COLD FRONT WILL SWEEP ACROSS THE LAKE AS EARLY AS THURSDAY
AFTERNOON...BUT MORE LIKELY THURSDAY NIGHT AS THE LOW TRACKS OVER
THE NORTHERN GREAT LAKES REGION. COLD ADVECTION WILL ALLOW FOR
WINDS TO MIX TO THE LAKE SURFACE AND A STRONG
GRADIENT...PARTICULARLY OVER THE NORTHERN PORTIONS OF THE
LAKE...WILL ALLOW WINDS TO INCREASE TO GALE FORCE. A GALE WATCH
MAY BE ISSUED WHEN MODEL GUIDANCE COMES INTO BETTER AGREEMENT.
HIGH PRESSURE WILL GRADUALLY BUILD WEST OF THE GREAT LAKES THIS
WEEKEND...SINKING SOUTHEAST ACROSS THE MID MISSISSIPPI RIVER
VALLEY LATE THIS WEEKEND...AND KEEPING LAKE MICHIGAN IN AT LEAST A
MODERATE GRADIENT AND PROPPING UP WINDS. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
410 AM CDT WED OCT 3 2012
...UPDATED SYNOPSIS AND SHORT TERM SECTIONS...
.SYNOPSIS...
ISSUED AT 408 AM CDT WED OCT 3 2012
A COMPACT BUT STRONG STORM SYSTEM CONTINUED TO DEVELOP EARLY THIS
MORNING OVER WESTERN MONTANA. RAP ANALYSIS SHOWED A 90-KT JET
STREAK AT 400MB ROUNDING THE BASE OF THE DEVELOPING TROUGH AXIS.
ADDITIONAL JET STREAK ENERGY CONTINUED TO DIG SOUTHWARD TOWARD THE
BASE OF THE TROUGH. THE MID LEVEL COLD FRONT WAS MOVING TOWARD
YELLOWSTONE NATIONAL PARK AS OF 08Z. NEAR THE CENTER OF THIS
STORM...SNOW OBSERVATIONS WERE FOUND AT GREAT FALLS AND CUT BANK,
MONTANA WHERE TEMPERATURES CONTINUED TO FALL INTO THE LOWER 30S.
AHEAD OF THIS STORM SYSTEM...SKY WAS CLEAR ACROSS PRETTY MUCH THE
ENTIRE GREAT PLAINS. SURFACE LEE TROUGH EXTENDED FROM A WEAK LOW
CENTER (1003MB) JUST EAST OF CHADRON, NE SOUTH-SOUTHWESTWARD INTO
EASTERN COLORADO.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 408 AM CDT WED OCT 3 2012
THE STRONG COLD FRONT PUSHING SOUTH TODAY WILL REACH THE SOUTHERN
NEBRASKA PANHANDLE BY LATE AFTERNOON. A DOWNSLOPE WARM THERMAL
RIDGE WILL NOSE NORTHEAST THROUGH NORTHWEST KANSAS INTO CENTRAL
NEBRASKA...WHICH IS WHERE WARMEST SURFACE TEMPERATURES SHOULD BE
TODAY (WITH SCATTERED HIGHS IN THE 91 TO 93F RANGE)...MAINLY NORTH
OF THE DDC FORECAST AREA. ACROSS SOUTHWEST KANSAS...UPPER 80S SHOULD
BE COMMON FOR HIGHS WHICH WAS WHAT THE PREVIOUS FORECAST HAD...SO NO
CHANGE OF SIGNIFICANCE WAS MADE. SURFACE WINDS LATE AFTERNOON
SHOULD REACH 15 TO 18 KNOTS EAST OF A WAKEENEY TO LIBERAL LINE WHERE
LOW LEVEL PRESSURE GRADIENT WILL RESIDE. TIMING OF THE FRONT IS
COMING INTO BETTER FOCUS...AND WILL LEAN ON THE NAM12 FOR TIMING.
AT 06Z...FRONT SHOULD BE KNOCKING ON THE DOOR STEP OF THE DDC
FORECAST AREA (SYRACUSE TO WAKEENEY LINE). THE SUBSTANTIAL PRESSURE
RISES BEHIND THE FRONT COMBINED WITH THE GRADIENT ITSELF SHOULD
RESULT IN SURFACE WINDS OF 25 TO 28 KNOTS SUSTAINED FOR PROBABLY A
THREE-HOUR PERIOD. THIS WILL LIKELY WARRANT ISSUANCE OF A WIND
ADVISORY...BUT WILL HOLD OFF ON ISSUANCE OF ONE THIS FORECAST
CYCLE. WILL GO AHEAD AND KEEP THE 20 POPS IN FOR AREAS MAINLY NORTH
OF HIGHWAY 96 FOR LIGHT RAIN SHOWERS GIVEN SUCH STRONG LOW LEVEL
FRONTOGENESIS IN THE 06-12Z TIME FRAME TONIGHT. SREF MEANS AND
ECMWF MODEL DOES SHOW A SLIGHT QPF SIGNAL...BUT ABSENCE OF QUALITY
LOW LEVEL MOISTURE WILL BE AN ISSUE TO GENERATE ANYTHING MORE THAN
JUST A FEW HUNDREDTHS OF AN INCH OF PRECIPITATION SHOULD ANY RAIN
SHOWERS FORM AT ALL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 249 AM CDT WED OCT 3 2012
MEDIUM RANGE MODELS INDICATE A STRONG UPPER LEVEL TROUGH OF LOW
PRESSURE SWINGING EASTWARD OUT OF THE NORTHERN PLAINS INTO THE
WESTERN GREAT LAKES REGION THURSDAY. THIS SYSTEM WILL BRING THE
POSSIBILITY FOR PRECIP TO THE DAKOTAS, NEBRASKA, AND INTO THE UPPER
MIDWEST THURSDAY. ALTHOUGH AN ATTENDANT COLD FRONT IS PROJECTED TO
PUSH SOUTHEAST INTO AND ACROSS WESTERN KANSAS EARLY THURSDAY, LITTLE
IF ANY PRECIP WILL BE POSSIBLE ACROSS SOUTHWEST AND CENTRAL KANSAS
DUE TO THE LACK OF LOW/MID LEVEL MOISTURE AND INSTABILITY. HOWEVER,
A STRONG JET IS EXPECTED TO TRANSITION OUT OF THE NORTHERN AND
CENTRAL ROCKIES INTO THE WESTERN HIGH PLAINS THURSDAY PROVIDING
STRONG UPPER LEVEL DYNAMICS. SO, CANNOT RULE OUT AN OUTSIDE SLIGHT
CHANCE FOR LIGHT PRECIP AS FAR SOUTH AS CENTRAL KANSAS TO INCLUDE
THE I-70 CORRIDOR. OTHERWISE, GENERALLY DRY CONDITIONS ARE EXPECTED
ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS THROUGH FRIDAY AFTERNOON.
THERE IS A CHANCE FOR PRECIP FRIDAY NIGHT INTO EARLY SATURDAY AS A
SECONDARY UPPER LEVEL JET CORE EJECTS OUT OF THE ROCKIES INTO THE
WESTERN HIGH PLAINS. THIS WILL COINCIDE WITH A COOLING OF THE
ATMOSPHERE AT ALL LEVELS BRINGING GFS AND ECMWF SOUNDING PROFILES
TO NEAR SATURATION FRIDAY NIGHT INTO EARLY SATURDAY.
TEMPERATURES WILL BE WELL BELOW NORMAL THURSDAY IN WAKE OF A STRONG
COLD FRONT PUSHING SOUTHEAST ACROSS WESTERN KANSAS WEDNESDAY NIGHT.
STRONG COLD AIR ADVECTION SOUTHWARD INTO WESTERN KANSAS WILL LOWER
H85 TEMPERATURES DOWN INTO THE SINGLE DIGITS(C) ACROSS THE AREA
WITH NEAR 10C IN FAR SOUTHWESTERN KANSAS. TEMPERATURES ARE LIKELY
TO STRUGGLE TO REACH THE 60S(F) WITH MID TO UPPER 50S(F) POSSIBLE
FURTHER NORTH NEAR THE I-70 CORRIDOR. SIMILAR HIGH TEMPERATURES
ARE EXPECTED FRIDAY BEFORE ANOTHER SURGE OF COLDER AIR DROPS SOUTH
INTO WESTERN KANSAS EARLY IN THE WEEKEND. THIS WILL KEEP
TEMPERATURES DOWN BELOW NORMAL THROUGH VERY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1225 AM CDT WED OCT 3 2012
LEE TROUGH DEVELOPMENT FROM EASTERN COLORADO INTO WESTERN NEBRASKA
WILL KEEP SURFACE WINDS FROM THE SOUTH AT GCK, DDC, HYS TERMINALS.
WIND SPEEDS WILL BE 8 TO 10 KNOTS THIS MORNING WITH AN INCREASE IN
WIND SPEEDS MID-LATE MORNING TO 15 TO 18 KNOTS. A STRONG COLD
FRONT WILL APPROACH LATE THIS EVENING WITH A WIND SHIFT TO THE
NORTH AND AN ABRUPT INCREASE IN SPEED. THE FRONT IS EXPECTED
AROUND 05-07Z TIME FRAME (RIGHT AT THE END OF THE CURRENT TAF
PERIOD) WITH 24 TO 28 KNOT WINDS FROM THE NORTH UPON PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 46 62 42 / 0 10 0 10
GCK 87 45 62 42 / 0 10 0 10
EHA 88 45 61 42 / 0 10 0 0
LBL 88 47 62 43 / 0 10 0 0
HYS 87 45 61 40 / 0 20 10 10
P28 86 52 64 46 / 0 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS GOODLAND KS
247 AM MDT WED OCT 3 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 247 AM MDT WED OCT 3 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS A SHORTWAVE RIDGE
EXTENDING NORTH ACROSS NORTHWEST KANSAS AND CENTRAL NEBRASKA.
UPSTREAM A TROUGH IS DIGGING SOUTH INTO NORTHERN IDAHO AND
WESTERN MONTANA. AT THE SURFACE...LOW PRESSURE REMAINS IN PLACE
ACROSS THE HIGH PLAINS WITH A SURFACE COLD FRONT DEEPENING ACROSS
SOUTH DAKOTA...AND A SURFACE TROUGH AXIS EXTENDING JUST WEST OF
THE COLORADO/KANSAS STATE LINE.
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS IN THE UPPER
80S/LOW 90S AS SOUTHERLY FLOW ADVECTS MUCH WARMER AIR INTO THE
REGION AHEAD OF THE APPROACHING COLD FRONT.
TONIGHT...THE COLD FRONT OVER SOUTH DAKOTA IS EXPECTED TO PUSH
SOUTH ACROSS THE CWA BY MIDNIGHT AS THE SHORTWAVE TROUGH DIGS
SOUTH AND EAST ACROSS THE NORTHERN PLAINS. WINDY CONDITIONS ARE
EXPECTED THIS EVENING AND OVERNIGHT BEHIND THE FRONT...AND WILL
APPROACH WIND ADVISORY CRITERIA WITH GUSTS POSSIBLY IN THE 40-45
MPH RANGE. I WAS NOT CONFIDENT ENOUGH TO GO THAT HIGH YET WITH
SOME DIFFERENCES BETWEEN GUIDANCE ON MAGNITUDE OF THE WINDS...AND
THE WINDOW FOR THESE CONDITIONS SEEMS TO BE FAIRLY BRIEF. A FEW
SHOWERS WILL BE POSSIBLE MAINLY IN THE 03Z- 09Z TIME FRAME WHEN
BEST LARGE SCALE ASCENT IS ADVERTISED. DUE TO THE SPEED AND
NORTHERN TRACK OF THE TROUGH AND MINIMAL MOISTURE...CONFIDENCE IS
LOW IN MEASURABLE PRECIP. I KEPT POPS LIMITED TO SLIGHT CHANCE
CATEGORY FOR NOW...AND CONSIDERED ONLY INCLUDING MENTION OF
SPRINKLES.
THURSDAY...COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN THE
50S/60S AND OVERNIGHT LOWS THURSDAY NIGHT IN THE MID 30S. WIND AND
INCREASING CLOUDS WILL LIMIT RADIATION COOLING THURSDAY
NIGHT...OTHERWISE I WOULD BE CONCERNED WITH HARD FREEZE CONDITIONS
BASED ON ADVERTISED H85 TEMPS IN THE 0C-3C RANGE. FOR NOW IT
LOOKS LIKE WE WILL BE IN THE UPPER LIMIT OF LOCAL FROST ADVISORY
CRITERIA.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 247 AM MDT WED OCT 3 2012
THE ANTICIPATED SIGNIFICANT WEATHER CHANGE STILL LOOKS ON TRACK
FOR THE WEEKEND AS A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH IS
FORECAST TO SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND
SATURDAY. DYNAMICS FROM A 105 KT JET AT 250 MB WILL ENHANCE LIFT
FRIDAY NIGHT INTO SATURDAY MORNING WHEN BOTH THE GFS/EC FORECAST A
SATURATED LOWER ATMOSPHERE. GIVEN 850 MB TEMPS OF ZERO TO -2C AND
SATURATED AIR ABOVE -10C...ANTICIPATE LIGHT SNOW ACROSS THE
COLORADO COUNTIES SATURDAY MORNING AND A RAIN-SNOW MIX POSSIBLE
FURTHER EAST. GUIDANCE SUGGESTS LOW AND MID LEVELS WILL RAPIDLY
DRY OUT SATURDAY AFTERNOON AS THE JET AXIS AND UPPER TROUGH SLIDE
SOUTHEAST OF THE FORECAST AREA...ENDING PRECIP CHANCES.
850 MB TEMPERATURES OF 0 TO -2C ARE FORECAST SATURDAY MORNING...
WARMING ONLY A FEW DEGREES BY LATE AFTERNOON. HIGHS WILL HOLD IN THE
40S WHICH IS 25-30 DEGREES BELOW NORMAL. THE NORTHWEST THIRD OF THE
AREA SHOULD SEE MIN TEMPS SATURDAY IN THE 30-32 F RANGE AND BY
SUNDAY MORNING WITH LESS CLOUDS...MIN TEMPERATURES COULD DROP AS LOW
AS THE UPPER 20S...MAINLY IN THE NORTHWEST...WITH LOW 30S ELSEWHERE.
AFTERNOON HIGH TEMPERATURES WILL MODERATE SUNDAY AND MONDAY WITH
TEMPS STILL BELOW NORMAL BUT RETURNING TO THE 50S SUNDAY AND 60S
MONDAY. BOTH GFS/EC HINT AT ANOTHER COLD FRONT ARRIVING TUESDAY
WITH THE AIR MASS MOVING THROUGH RATHER QUICKLY...AND THE
POTENTIAL FOR PRECIPITATION AROUND MID WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1121 PM MDT TUE OCT 2 2012
VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH THE PERIOD. A COLD
FRONT WILL MOVE THROUGH BOTH TERMINALS LATE WEDNESDAY
AFTERNOON/EARLY EVENING WITH A WIND SHIFT TO THE NORTH AND WIND
SPEEDS INCREASING TO 20 TO 30KTS WEDNESDAY NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 247 AM MDT WED OCT 3 2012
RH VALUES LOOK TO DROP TO WITHIN RED FLAG CRITERIA OVER MOST OF
THE AREA HOWEVER WINDS WILL REMAIN MARGINAL...WITH THE BEST CHANCE
FOR RED FLAG CONDITIONS OVER THE NORTHWEST LATE THIS AFTERNOON.
WINDS WILL INCREASE THIS EVENING...HOWEVER BY THAT POINT RH SHOULD
RECOVER ABOVE CRITERIA. I DO NOT PLAN ON A RFW AT THIS
TIME...SINCE WE LIKELY WONT MEET THE 3HR REQUIREMENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...DLF
AVIATION...024
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS JACKSON MS
417 AM CDT WED OCT 3 2012
.SHORT TERM...IR IMAGERY THIS MORNING CLEARLY DEPICTS THE CLOSED
UPPER LOW OVER NORTHERN LA...WITH AREA RADARS SHOWING A CLUSTER OF
SHOWERS AND THUNDERSTORMS OVER CATAHOULA AND CONCORDIA PARISH.
SURFACE ANALYSIS SHOWS THESE STORMS DEVELOPING ALONG A WEAK SURFACE
BOUNDARY DRAPED ROUGHLY FROM MOBILE TO JUST NORTH OF ALEXANDRIA. THE
LATEST HRRR RUN VERIFIED THIS CONVECTION ALMOST PERFECTLY...AND
SUGGESTS THESE STORMS WILL BEGIN TO DIMINISH BY SUNRISE AS THEY
DRIFT NORTH. THE QUESTION THEN BECOMES...WHAT KIND OF CHANCE DO WE
HAVE FOR SEEING ADDITIONAL SHOWERS AND STORMS LATER THIS AFTERNOON?
NWP GUIDANCE INDICATES THE UPPER LOW WILL BEGIN TO OPEN AND LIFT
NORTHWARD TODAY AS THE UPPER JET STRENGTHENS OVER AL...WITH THE
WEAKENING S/WV SHIFTING EAST ACROSS THE CWA THROUGH THE DAY. FORCING
FOR ASCENT IN ADVANCE OF THE WAVE WILL BE RATHER POTENT ACROSS
SOUTHERN/SOUTHEASTERN AREAS TODAY...AND COUPLED WITH /1.THE
AFOREMENTIONED BOUNDARY LIFTING NORTHWARD INTO SOUTHERN PORTIONS OF
THE CWA BY LATE MORNING AND /2.SURFACE HEATING RAISING SBCAPE VALUES
ACROSS SOUTHERN/SOUTHEASTERN AREAS INTO THE 600-800J/KG RANGE/ I
THINK THE INGREDIENTS WILL BE SUFFICIENT FOR AT LAST ISOLATED
CONVECTIVE DEVELOPMENT. BEST GUESS RIGHT NOW IS FOR THIS ACTIVITY TO
START ACROSS SOUTHERN ZONES AROUND MID DAY...DRIFTING NORTHWARD/
NORTHEASTWARD WITH ADDITIONAL ISOLATED DEVELOPMENT FURTHER NORTH AND
EAST AS THE DAY WEARS ON. A COMBINATION OF SETTING SUN AND THE BEST
LIFT PUSHING EAST SHOULD BRING THIS ALL TO AN END BY EARLY EVENING.
BASED ON CONVECTIVE PARAMETERS OFFERED BY THE MORE REASONABLE
LOOKING 00Z GFS/ECMWF IT DOESN`T APPEAR SEVERE STORMS WILL BE A HUGE
CONCERN...BUT GIVEN RATHER COLD TEMPS ALOFT I COULD SEE ONE OR TWO
BECOMING STRONG ENOUGH TO POSE A 40 MPH WIND GUST AND SMALL HAIL
RISK.
ONCE THIS ALL CLEARS OUT THE FORECAST BECOMES RATHER UNEVENTFUL AS A
ZONAL UPPER FLOW PATTERN TAKES SHAPE ACROSS THE SOUTHEASTERN STATES
AND SURFACE RIDGING NOSES IN FROM THE EAST. SKIES SHOULD REMAIN
MOSTLY CLEAR THROUGH THE END OF THE WEEK ACCOMPANIED BY DAYTIME
TEMPS CLIMBING BACK ABOVE NORMAL BY TOMORROW WITH HIGHS IN THE MID
80S. LOWS TONIGHT AND TOMORROW NIGHT WILL COME IN MID-UPPER 50S FOR
MOST AREAS. /BK/
.LONG TERM...THE NEXT SURFACE BOUNDARY BEGINS TO MOVE INTO NRN MS
FRIDAY NIGHT. THE GFS IS ONCE AGAIN SHOWING A FASTER SWD PROGRESSION
THAN THE EURO...THE LATEST EURO COMING IN SLIGHTLY SLOWER THAN IT
WAS YESTERDAY. THE EURO MOVES THE COLD FRONT JUST INTO THE NWRN
CORNER OF THE FORECAST AREA BY EARLY SATURDAY AFTERNOON WHILE THE
GFS BRINGS IT INTO THE VICINITY OF THE NATCHEZ TRACE. SLOWER
PROGRESSION NOTWITHSTANDING...MODELS ARE IN AGREEMENT THAT THE FRONT
WILL USHER A COLD AIR MASS INTO THE FORECAST AREA WITH SINGLE DIGIT
850 MB TEMPS ACROSS MOST OF THE AREA FOR SUNDAY THROUGH MONDAY.
MODERATION OF TEMPERATURES BEGINS TUESDAY WHEN THE SURFACE HIGH
CENTER LIFTS TO THE NE OF THE AREA AND 850 MB W/SWLY FLOW RETURNS.
THE AIR MASS WILL REMAIN DRY AHEAD OF THE BOUNDARY. LITTLE IN THE
WAY OF LOW LEVEL CONVERGENCE IS EXPECTED ALONG THE FRONT AND LOW
LEVEL/850 MB RIDGING WILL HOLD STEADY AS IT APPROACHES. BETTER UPPER
LEVEL FORCING IS EXPECTED TO THE REAR OF THE FRONT IN RESPONSE TO A
BROAD UPPER TROUGH THAT WILL DIG INTO THE ERN U.S...A HEALTHY
SHORTWAVE PIVOTING INTO THE MID/UPPER MS VALLEY SATURDAY NIGHT.
DUE TO THE SLOWER EURO AND THE SLOWER ADVANCE OF THE GFS QPF
FIELD...MEX POPS HAVE BEEN CUT SLIGHTLY FOR FRIDAY NIGHT. HAVE KEPT
THE VERY LOW RAIN CHANCES PAINTED FOR SUNDAY/SUNDAY NIGHT AS A
SECOND UPPER WAVE DIGS INTO THE LONG WAVE TROUGH. HAVE ALSO
INCREASED SATURDAY HIGHS A FEW DEGREES OVER MEX NUMBERS IN LIGHT OF
THE POTENTIAL FOR SLOWER FRONTAL PROGRESSION BUT NOT AS MUCH AS THE
EURO WHICH IS UP TO TEN DEGREES WARMER IN DELTA REGIONS THAN THE MEX
FOR SATURDAY AFTERNOON. ALSO DECREASED SUNDAY HIGHS A FEW DEGREES IN
THE NORTH TO KEEP THOSE AREAS SLIGHTLY COOLER THAN AREAS FARTHER
SOUTH AND SLOWED THE WARM UP THROUGH MONDAY AND TUESDAY SLIGHTLY.
&&
.AVIATION...CLR SKIES/LGT WINDS ALLOWING MVFR VSBY IN FOG TO DEVELOP
AT SEVERAL SITES THIS MORNING...AND WOULD NOT BE SURPRISED TO SEE
IFR VSBY OFF AND ON THROUGH ~13Z BEFORE THINGS TREND VFR. VFR CONDS
WILL THEN PREVAIL THRU THE DAY AND INTO THE EVENING BEFORE A RETURN
OF MVFR VSBY BECOMES PSBL AT MOST SITES 07-13Z TOMORROW. THERE`S A
CHANCE ISOLD SHWRS/TSRA WILL DEVELOP ACROSS SRN/SERN MS THIS AFTN AS
AN UPPER DISTURBANCE PASSES. CALM SFC WINDS THIS MORNING BECMG SRLY
5-8KTS THIS AFTN. /BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 81 56 85 56 / 13 3 2 7
MERIDIAN 82 52 85 51 / 14 5 2 7
VICKSBURG 81 55 86 55 / 11 3 2 7
HATTIESBURG 84 57 87 57 / 19 8 3 4
NATCHEZ 81 56 85 57 / 15 3 2 6
GREENVILLE 80 57 86 58 / 5 3 2 7
GREENWOOD 80 55 86 56 / 7 3 2 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BK/03
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1052 PM PDT Tue Oct 2 2012
.SYNOPSIS...The cold front that moved through the region on
Tuesday will bring the first taste of Autumn to the area.
Temperatures will actually be below normal on Wednesday with most
locations seeing freezing temperatures Wednesday night. Dry and
seasonable weather will continue through the rest of the week and
the upcoming weekend.
&&
.DISCUSSION...
Update to the forecast to increase the shower activity over the
northeast. Bonners Ferry METAR is reporting rain and a spotter
east of there had a snow shower. The radar mosaic shows that the
upper low has now dropped southeastward to around Libby, MT.
Showers are wrapping around this low, coming from the northeast
into the Panhandle. Latest HRRR runs have picked up on this idea
and suggest showers could move as far west as Colville around
midnight and then move off to the southeast overnight. This would
actually bring a threat of showers to the Cd`A area. Accumulating
snow level will be above 3000 feet but a mix of rain/snow could
fall as low as 2000 feet with no accumulation. All of this
activity should be into Montana by sunrise Wednesday. RJ
&&
.AVIATION...
06Z TAFS: Winds will gradually decrease overnight. Blowing dust is
not expected to be a problem for the rest of tonight. Smoke from
wild fires has also been scoured out of the area by the cold
front. A large fire that developed south of KOMK isn`t expected to
cause smoke problems tonight due to the windy conditions. The
Wenatchee Complex fires are also not expected to cause smoke
problems at KEAT tonight. RJ
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 37 60 32 59 34 59 / 10 0 0 0 0 0
Coeur d`Alene 36 60 31 59 31 59 / 20 0 0 0 0 0
Pullman 35 60 30 58 29 58 / 0 0 0 0 0 0
Lewiston 41 66 38 65 38 65 / 0 0 0 0 0 0
Colville 32 65 30 64 29 64 / 20 0 0 0 0 0
Sandpoint 38 58 30 56 30 58 / 30 0 0 0 0 0
Kellogg 34 53 30 57 32 57 / 20 0 0 0 0 0
Moses Lake 40 67 33 65 33 65 / 0 0 0 0 0 0
Wenatchee 45 65 37 65 41 65 / 0 0 0 0 0 0
Omak 37 67 31 66 34 66 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...AIR QUALITY ALERT until Noon PDT Thursday for East Slopes
Northern Cascades-Okanogan Valley-Waterville Plateau-
Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
340 AM CDT WED OCT 3 2012
.SHORT TERM...TODAY THROUGH FRIDAY
340 AM CDT WED OCT 3 2012
CONCERN REMAINS FOCUSED ON STRONG PATTERN-CHANGING COLD FRONT ON
THURSDAY AND RAIN CHANCES WITH IT.
SURFACE MAP EARLY THIS MORNING HAD A RIDGE OF HIGH PRESSURE
EXTENDING ACROSS THE GREAT LAKES INTO WISCONSIN AND IOWA. LIGHT/CALM
WINDS AND CLEAR SKIES HAS ALLOWED SOME AREAS OF FOG TO DEVELOP
ACROSS EASTERN INTO PORTIONS OF CENTRAL WISCONSIN. VISIBILITY
HOLDING AROUND 3/4SM AT VOLK FIELD IN JUNEAU COUNTY. THINKING THIS
WILL LIKELY BE THE EXTENT OF THE FOG...SO NO HEADLINES EXPECTED AT
THIS TIME. TEMPERATURES VARIED ACROSS THE AREA THIS MORNING...RANGING FROM
36 DEGREES AT BLACK RIVER FALLS WI WHERE WINDS WERE CALM...TO 54
DEGREES AT CHARLES CITY AND DECORAH IOWA WHERE WINDS WERE STIRRING A
BIT FROM THE SOUTHEAST. OTHERWISE...LOOKING AT THE BIGGER
PICTURE...WATER VAPOR IMAGERY SHOWING A VIGOROUS MID-LEVEL TROUGH
DIGGING INTO THE NORTHERN ROCKIES. THIS FEATURE WILL EVENTUALLY
AFFECT US BY THURSDAY.
03.00Z NCEP MODEL SUITE AS WELL AS THE GEM/ECMWF ALL IN PRETTY GOOD
AGREEMENT THROUGH THE PERIOD WITH REGARD TO OVERALL SYNOPTIC
SETUP.
FOR TODAY...LOOK FOR THE RIDGE AXIS OF HIGH PRESSURE TO DRIFT SLOWLY
SOUTHEAST OF THE AREA BY THIS AFTERNOON AS A COLD FRONT HANGS UP
OVER MN INTO SD/NEB. NAM SHOWING 925MB TEMPERATURES WARMING INTO THE
17-19C RANGE ACROSS THE AREA TODAY. THIS IS UP A COUPLE DEGREES C
FROM YESTERDAY. YESTERDAY/S HIGHS WERE IN THE LOWER 70S...SO MIDDLE
TO UPPER 70S CAN BE EXPECTED FOR TODAY. IT WILL BE PRETTY DRY AS
WELL...ESPECIALLY WEST OF THE MISSISSIPPI RIVER WHERE DEEPER MIXING
WILL OCCUR. ALTHOUGH NO HEADLINES ARE EXPECTED...AN ELEVATED FIRE
THREAT STILL EXISTS OVER THE MORE OPEN AND WIND-PRONE AREAS OF
NORTHEAST IA/SOUTHEAST MN. FOR FURTHER DETAILS...SEE FIRE WEATHER
SECTION BELOW.
STRONG SURFACE CYCLOGENESIS WILL TAKE PLACE TONIGHT AS THAT
AFOREMENTIONED VIGOROUS TROUGH OVER THE NORTHERN ROCKIES MOVES INTO
THE PLAINS. MAIN PRECIPITATION FOCUS WITH THIS CYCLOGENESIS WILL BE
FOCUSED ON STRONG FRONTOGENESIS ACROSS NORTHERN MN/ND ON THE
NORTHWEST SIDE OF THE STRENGTHENING LOW. DYNAMIC COOLING EXPECTED TO
SPREAD SNOW ACROSS THAT AREA. MEANWHILE...A MODERATE SURGE OF 850MB
MOISTURE TRANSPORT ALONG OF THE ADVANCING SURFACE COLD FRONT OUT OF
MN/IA TOWARD MORNING WILL COMBINE WITH NOSE OF 90KT 300MB JET FOR A
CHANCE OF SHOWERS ACROSS PORTIONS OF WESTERN IA. THESE SHOWERS ARE
EXPECTED TO HOLD JUST WEST OF THE AREA THROUGH SUNRISE.
FOR THURSDAY...COLD FRONT WILL CONTINUE TO SURGE EAST ACROSS THE
FORECAST AREA AS SURFACE LOW CONTINUES TO DEEPEN ACROSS NORTHERN MN.
850MB MOISTURE TRANSPORT AND LIFT AIDED BY THE NOSE OF 300MB JET
WILL CONTINUE TO PRODUCE A GOOD CHANCE OF SHOWERS THROUGH THE
MORNING. NAM ALSO SHOWING CORRIDOR OF 300-500J/KG 0-3KM MUCAPE
ADVANCING INTO THE AREA IN THE 12-18Z TIME FRAME SOUTH OF I-94.
SO...GIVEN THIS AND STRONG DYNAMICS OF THIS SYSTEM...CONTINUED THE
ISOLATED THUNDER MENTION AS WELL. APPEARS STRONG DRY SLOT WILL
OVERTAKE THE AREA IN THE AFTERNOON AS LOW OCCLUDES OVER NORTHERN MN.
LOOK FOR WEST WINDS TO INCREASE THROUGH THE DAY AS THIS DRY SLOT
MOVES INTO THE AREA. SUSTAINED WINDS EXPECTED TO BE IN THE 15 TO 20
MPH RANGE WITH GUST IN THE 30-35 MPH RANGE BY AFTERNOON. IN THE
MEANTIME...NAM SHOWS 925MB TEMPERATURES COLLAPSING INTO THE 5-10C BY
LATER IN THE AFTERNOON. THIS WILL MARK THE END OF THE UNSEASONABLY
WARM WEATHER THAT THE REGION HAS BEEN ENJOYING AS OF LATE.
ALSO...STRONG WINDS WILL LIKELY PUT A DENT IN THE VERY COLORFUL FALL
FOLIAGE THAT HAS ALSO BEEN ENJOYED AS OF LATE.
CLEARING/DRY SLOT WILL CONTINUE TO BE OVER THE AREA TONIGHT AS THE
LOW MOVES LITTLE ACROSS THE ARROWHEAD OF MN INTO WESTERN LAKE
SUPERIOR. COLD AIR ADVECTION UNDER THE LOW WILL DRAG 925MB
TEMPERATURES INTO THE ZERO TO -4C RANGE BY 12Z FRIDAY. AS A
RESULT...OVERNIGHT LOWS ACROSS THE FORECAST AREA ARE EXPECTED TO
DROP INTO THE LOWER/MIDDLE 30S. AND...WITH THE CONTINUATION OF BRISK
WEST WINDS...WIND CHILLS WILL BE IN THE 20S AFTER MIDNIGHT.
COOL/BLUSTERY CONDITIONS WILL CONTINUE FRIDAY AS THE LOW LIFTS
NORTHEAST INTO ONTARIO. STEEP LOW LEVEL LAPSE RATES WILL PRODUCE AN
EXPANSIVE AREA OF CUMULUS ALONG WITH SCATTERED RAIN/SNOW SHOWERS
ACROSS NORTHERN WI. BELIEVE THIS PRECIPITATION WILL STAY NORTH OF
THE AREA. OTHERWISE...LOOK FOR HIGHS IN THE 40S ACROSS NORTHERN
WISCONSIN...TO THE LOWER 50S ACROSS NORTHEAST IOWA INTO FAR
SOUTHWEST WI.
FRIDAY NIGHT WILL SEE A MID-LEVEL AND SURFACE TROUGH DROP SOUTHEAST
INTO NORTHERN WISCONSIN FOR A CHANCE OF LIGHT SNOW ACROSS
CLARK/TAYLOR COUNTIES AS LOWS THERE DIP INTO THE UPPER 20S. REST OF
THE AREA SHOULD SEE PARTLY CLOUDY SKIES WITH LOWS IN THE UPPER 20S
TO LOWER 30S.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
340 AM CDT WED OCT 3 2012
03.00Z GFS/ECMWF CONTINUE TO SHOW OVERALL COOL/CYCLONIC FLOW OVER
THE AREA THROUGH THE PERIOD FOR BELOW NORMAL TEMPERATURES. TROUGH
AFFECTING THE AREA FRIDAY NIGHT WILL DROP FARTHER SOUTHEAST INTO THE
AREA ON SATURDAY FOR A SMALL CHANCE OF SNOW IN THE EARLY MORNING
MAINLY ALONG AND NORTH OF I-94...CHANGING TO ALL RAIN BY LATER IN
THE MORNING. APPEARS ANY ACCUMULATING SNOW DOES NOT LOOK LIKELY AS
THE GROUND WILL BE TOO WARM. MODELS IN GOOD AGREEMENT WITH A FAIRLY
VIGOROUS EMBEDDED SHORTWAVE TROUGH/SURFACE LOW DROPPING INTO THE
AREA ON MONDAY/TUESDAY. APPEARS OUR AREA WILL BE IN THE WARM SECTOR OF THIS
CYCLONE WITH BEST LIFT/CHANCES FOR PRECIPITATION REMAINING ACROSS
NORTHERN MN INTO NORTHERN WI. OTHERWISE...LOOK FOR HIGHS IN THE 40S
ON SATURDAY...WARMING WELL INTO THE 50S MONDAY AND TUESDAY.
&&
.AVIATION...THROUGH 06Z THURSDAY
1153 PM CDT TUE OCT 2 2012
FORECAST CONCERN REMAINS ON VALLEY FOG POTENTIAL AT KLSE. AT
05Z...MODEL SOUNDINGS APPEAR TO BE ON TRACK WITH THE LOW LEVEL
WINDS PER BLUFF TOP OBSERVATIONS HERE AT THE OFFICE...WITH THE
WINDS INCREASING JUST IN THE PAST HOUR. THE 03.02Z RAP SOUNDING
DOES SHOW SOME 10 TO 12 KNOT WINDS ABOVE THE INVERSION...WITH
OTHERWISE LIGHTER WINDS ELSEWHERE AND THE 03.00Z NAM DOING THE
SAME FEEL VALLY FOG POTENTIAL WILL AGAIN BE MORE PATCHY IN NATURE
WITH A LOWER CEILING DEVELOPING INSTEAD. GFSMOS AND GFSLAMP DATA
HAVE BACKED OFF ON VISIBILITY RESTRICTIONS. THUS WILL GO WITH BCFG
IN THE TAF. OTHERWISE...VFR CONDITIONS EXPECTED WITH SOUTHERLY
WINDS AROUND 12 KNOTS DEVELOPING AT KRST BETWEEN 15Z- 01Z.
&&
.FIRE WEATHER...TODAY
340 AM CDT WED OCT 3 2012
DRY CONDITIONS COUPLED WITH SOUTHERLY WINDS OF 10-20 MPH WILL LEAD TO
SOME ELEVATED FIRE WEATHER CONCERNS ACROSS PORTIONS OF SOUTHEAST
MINNESOTA AND NORTHEAST IOWA. ALTHOUGH RELATIVE HUMIDITIES ARE
EXPECTED TO DROP INTO THE 20-30 PERCENT RANGE IN THE AFTERNOON
ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA...WINDS WILL BE TOO
LOW TO SUPPORT RED FLAG CRITERIA. DUE TO THE LIGHTER WINDS...NO FIRE
WEATHER HEADLINES WILL BE ISSUED AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
340 AM CDT WED OCT 3 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...RABERDING
FIRE WEATHER...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1153 PM CDT TUE OCT 2 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY
312 PM CDT TUE OCT 2 2012
THE MAIN FOCUS THROUGH THE REST OF THE WEEK IS WITH A POTENT COLD
FRONT THAT WILL MOVE ACROSS THE REGION EARLY ON THURSDAY AND BRING
AN END TO THIS FIRST RUN OF INDIAN SUMMER.
ANOTHER DAY OF PLEASANT AND DRY CONDITIONS ACROSS THE REGION TODAY
AS WE REMAIN SANDWICHED IN BETWEEN TWO LOW PRESSURE SYSTEMS WITH
HIGH PRESSURE IN BETWEEN OVER THE UPPER MISSISSIPPI VALLEY FROM
THE SURFACE THROUGH THE UPPER LEVELS OF THE ATMOSPHERE. THIS RIDGE
AXIS WILL SLOWLY DRIFT TO THE EAST TONIGHT INTO TOMORROW AS THE
MID LEVEL TROUGH TO THE SOUTHEAST AND THE OTHER TROUGH OVER SOUTH
CENTRAL CANADA MAKE SOME SLOW PROGRESS EASTWARD. WITH THE CORE OF
THE RIDGE OVERHEAD FOR MUCH OF THE OVERNIGHT PERIOD...SKIES WILL
BE CLEAR WITH WINDS LIGHT FROM THE SURFACE ON UP THROUGH 15KFT.
THIS SETUP SHOULD PRODUCE SOME RADIATIONAL FOG THAT FORMS IN LOW
SPOTS AND VALLEYS...PARTICULARLY ACROSS WESTERN WISCONSIN. LOW
LEVEL WINDS AROUND 925MB DO PICK UP TOWARD DAYBREAK ACROSS
SOUTHEAST MINNESOTA...BUT ARE STILL LIGHT ENOUGH AT 10KTS THAT
SOME RIVER VALLEY FOG SHOULD FORM.
THE WARMEST DAY OF THE WEEK WILL BE ON WEDNESDAY AS THE TROUGH
OVER THE NORTHERN PLAINS BECOMES MORE NEGATIVELY TILTED AND A
DEEPENING SURFACE LOW FORMS IN SOUTHEAST SOUTH DAKOTA WITH SURFACE
WINDS INCREASING OUT OF THE SOUTH ACROSS THE REGION. THE CORE OF
THE WARMEST LOW LEVEL AIR REMAINS OFF TO THE WEST...BUT WITH FULL
SUNSHINE AND SOUTHERLY WINDS SURFACE TEMPERATURES SHOULD BE ABLE
TO CLIMB UP INTO THE UPPER 70S TO AROUND 80. THIS SETUP MAY LEAD
TO SOME FIRE WEATHER CONCERNS WHICH ARE OUTLINED IN THE FIRE
WEATHER SECTION IN THIS AFD DOWN BELOW.
THE MAIN FORECAST CHALLENGE IS WITH THE TIMING OF THE COLD FRONT
PASSAGE ALONG WITH HOW LIKELY IT WILL BE THAT IT WILL RAIN AS THE
FRONT COMES THROUGH. THERE IS NOT A LOT OF CONSISTENCY AMONGST THE
02.12Z GUIDANCE WEDNESDAY NIGHT INTO THURSDAY WITH THE COLD FRONT
AND LOW PRESSURE SYSTEM AS IT MOVES THROUGH THE REGION. THE 02.12Z
NAM AND GFS ARE THE FASTEST WITH THE COLD FRONT REACHING EASTERN
WISCONSIN BY 18Z THURSDAY...THOUGH THE NAM SHOWS A MUCH MORE
OCCLUDED LOW TO THE NORTH ON THURSDAY. THE CONCERNING PART OF
THE LAST FEW MODEL RUNS HAS BEEN THE TREND TOWARD GOING WITH A
DRIER SOLUTION DESPITE THE STRONG DYNAMIC FORCING. GIVEN THE
LATEST TRENDS...IT APPEARS THAT THE BETTER CHANCES FOR THE
CROSSOVER IN FORCING AND MOISTURE WILL BE ACROSS NORTHEAST IOWA
INTO FAR SOUTHEAST MINNESOTA AND WESTERN WISCONSIN THURSDAY
MORNING ALONG AND JUST BEHIND THE FRONTAL PASSAGE. INSTABILITY
LOOKS MARGINAL AT BEST...BUT SOME OF THE CONVECTIVE MODELS DO SHOW
SOME STORMS DEVELOPING AS THE FRONT COMES THROUGH...SO HAVE LEFT
SOME ISOLATED THUNDER MENTION IN ON THURSDAY MORNING. COLD AIR
WILL QUICKLY MOVE IN ACROSS THE REGION WITH HIGH TEMPERATURES
LIKELY COMING IN THE EARLY MORNING HOURS BEFORE DROPPING OR
STABILIZING THROUGH THE REST OF THE DAY. WINDS WILL ALSO BECOME
GUSTY UP TO 25-30KTS THROUGH THE REST OF THE AFTERNOON AS THE DRY
SLOT MOVES IN WHICH WILL HELP TO LIKELY END THE COLORFUL FOLIAGE
THAT HAS BEEN PRESENT THROUGH MUCH OF THE REGION OVER THE PAST FEW
WEEKS.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
312 PM CDT TUE OCT 2 2012
NOT MUCH CONFIDENCE IN THE EXTENDED PERIOD FROM THE WEEKEND INTO
EARLY NEXT WEEK AS THE 02.12Z GFS PUSHES FOR A COLDER SOLUTION
WITH A SYSTEM DROPPING THROUGH THE REGION ON MONDAY WHILE THE
02.12Z ECMWF IS WARMER AFTER THE INITIAL COLD SURGE GOING INTO
MONDAY AND TUESDAY AND LINGERS SOME PRECIPITATION ALONG THE
INVERTED TROUGH THIS WEEKEND. THERE AT LEAST IS AGREEMENT THAT
TEMPERATURES WILL STAY BELOW NORMAL THROUGH THE WEEKEND WITH 850MB
TEMPERATURES DROPPING DOWN TO -6C FRIDAY THROUGH SUNDAY BEFORE LOW
LEVEL WARM AIR ADVECTION KICKS BACK IN SUNDAY NIGHT. BEYOND
THAT...THE 02.12Z GFS ADVECTS COLDER AIR BACK IN WHILE THE 02.12Z
ECMWF STRONGLY ADVECTS WARMER AIR IN FROM THE SOUTHWEST. THE GFS
HAS AT LEAST HAD SOME CONSISTENCY TO IT WITH THE MONDAY
SYSTEM...SO FEEL A LITTLE STRONGER TOWARD GOING IN THAT DIRECTION
FOR NOW WITH KEEPING THE COOLER AIR AROUND INTO NEXT WEEK.
PRECIPITATION TYPES COULD BE AN ISSUE...BUT ITS RATHER BORDERLINE
RIGHT NOW FOR WHETHER IT WOULD BE COLD ENOUGH TO SUPPORT A MIX OF
RAIN/SNOW. THE INVERTED SURFACE TROUGH WILL HAVE TO BE WATCHED
THIS WEEKEND AS WELL FOR PRECIPITATION CHANCES IF THE HIGH DOES
NOT BUILD IN AS STRONGLY AS THE GFS IS FORECASTING.
&&
.AVIATION...THROUGH 06Z THURSDAY
1153 PM CDT TUE OCT 2 2012
FORECAST CONCERN REMAINS ON VALLEY FOG POTENTIAL AT KLSE. AT
05Z...MODEL SOUNDINGS APPEAR TO BE ON TRACK WITH THE LOW LEVEL
WINDS PER BLUFF TOP OBSERVATIONS HERE AT THE OFFICE...WITH THE
WINDS INCREASING JUST IN THE PAST HOUR. THE 03.02Z RAP SOUNDING
DOES SHOW SOME 10 TO 12 KNOT WINDS ABOVE THE INVERSION...WITH
OTHERWISE LIGHTER WINDS ELSEWHERE AND THE 03.00Z NAM DOING THE
SAME FEEL VALLY FOG POTENTIAL WILL AGAIN BE MORE PATCHY IN NATURE
WITH A LOWER CEILING DEVELOPING INSTEAD. GFSMOS AND GFSLAMP DATA
HAVE BACKED OFF ON VISIBILITY RESTRICTIONS. THUS WILL GO WITH BCFG
IN THE TAF. OTHERWISE...VFR CONDITIONS EXPECTED WITH SOUTHERLY
WINDS AROUND 12 KNOTS DEVELOPING AT KRST BETWEEN 15Z- 01Z.
&&
.FIRE WEATHER...WEDNESDAY
312 PM CDT TUE OCT 2 2012
DRY CONDITIONS COUPLED WITH SOME GUSTY WINDS OF 15-20 MPH MAY LEAD
TO SOME NEAR CRITICAL FIRE WEATHER CONCERNS ACROSS PORTIONS OF
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. A LOW PRESSURE SYSTEM
WILL MOVE ACROSS THE DAKOTAS AND MINNESOTA TOMORROW WITH WARM AND
DRY SOUTHERLY WINDS IN PLACE AHEAD OF THIS SYSTEM. RELATIVE
HUMIDITIES ARE FORECAST TO DROP INTO THE 20-30 PERCENT RANGE IN
THE AFTERNOON ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA THOUGH
WINDS WILL BE TOO LOW AT 10-20MPH TO SUPPORT RED FLAG CONDITIONS.
GIVEN THE DRY CONDITIONS ALREADY IN PLACE AND THE FACT THAT A LOT
OF VEGETATION IS LIKELY DEAD TO DO A KILLING FREEZE LAST
WEEK...FIRE WEATHER CONDITIONS ARE EXPECTED TO BE NEAR
CRITICAL. DUE TO THE LIGHT WINDS...NO FIRE WEATHER WATCHES OR RED
FLAG WARNINGS WILL BE ISSUED AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
312 PM CDT TUE OCT 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
FIRE WEATHER...HALBACH
AREA FORECAST DISCUSSION
NWS TAUNTON MA
941 AM EDT WED OCT 3 2012
.SYNOPSIS...
A FEW SHOWERS ARE POSSIBLE THROUGH TONIGHT...BUT A BETTER CHANCE
OF SHOWERS EXISTS THURSDAY AFTERNOON AND EVENING WITH A COLD
FRONT. DRY WEATHER FOLLOWS FRIDAY. ANOTHER COLD FRONT MOVES
THROUGH THE REGION ON SATURDAY...WHICH WILL LIKELY BE FOLLOWED BY
A PERIOD OF RAIN SOMETIME SATURDAY NIGHT INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
940 AM UPDATE...
FORECAST ON TRACK. EXPECT CLOUDS/FOG/DRIZZLE TO PERSIST THROUGH
MIDDAY...BUT CLOUDS WILL REMAIN LOCKED IN THROUGH AFTERNOON WITH
PLENTY OF LOW LEVEL MOISTURE AND LIGHT WINDS /N INLAND AND E-NE
NEAR COAST/.
RADAR MOSAIC SHOWS BATCH OF SHOWERS LIFTING NE FROM NJ WHICH
SHOULD REACH CT VALLEY AROUND MIDDAY. 3KM HRRR SHOWS ONLY
SCATTERED SHOWERS AT BEST THIS AFTERNOON...PRIMARILY S OF MASS
PIKE.
FORECAST HIGHS ON TRACK. STILL CONCERNED 70S MAY BE A STRETCH
INLAND GIVEN CLOUD COVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...
UPPER LEVEL RIDGING FROM THE ATLANTIC WILL CONTINUE TO
NOSE INTO SOUTHERN NEW ENGLAND. THIS SHOULD PREVENT WIDESPREAD
PRECIPITATION IN OUR REGION. HOWEVER...WARM ADVECTION AND DEEP
MOISTURE MAY RESULT IN A FEW SHOWERS AT TIMES BUT A WASHOUT IS NOT
EXPECTED. WILL RUN WITH SOME CHANCE POPS. WE ALSO EXPECT TO SEE
MORE AREAS OF FOG AND PATCHY DRIZZLE GIVEN DEEP LOW LEVEL MOISTURE.
LOW TEMPERATURES SHOULD ONLY FALL INTO THE UPPER 50S TO AROUND 60 IN
MOST LOCATIONS GIVEN CLOUD COVER AND LOW LEVEL MOISTURE.
THURSDAY...
SCATTERED SHOWERS ARE POSSIBLE ACROSS THE REGION THROUGH
EARLY AFTERNOON IN THE WARM ADVECTION PATTERN. A BETTER CHANCE OF
MORE WIDESPREAD PRECIPITATION WILL EXIST FROM THE MID AFTERNOON INTO
THE EVENING HOURS. THIS IN RESPONSE TO A STRONG SHORTWAVE LIFTING
ACROSS NEW ENGLAND AND AN ASSOCIATED WAVE OF LOW PRESSURE. ENOUGH
CONFIDENCE TO WARRANT SOME LIKELY TO LOW END CATEGORICAL POPS FOR AT
LEAST A FEW HOURS ACROSS A GOOD PORTION OF THE REGION. HIGHEST POPS
WILL BE IN OUR NORTHWEST ZONES WHERE THE BETTER DYNAMICS RESIDE.
GIVEN HIGH PWAT VALUES...BRIEF HEAVY RAIN RAIN SHOWERS ARE ALSO A
POSSIBILITY. INSTABILITY IS LIMITED...BUT AN ISOLATED THUNDERSTORM
OR TWO CAN/T BE RULED OUT ACROSS OUR INTERIOR ZONES.
HIGH TEMPS ARE TRICKY AGAIN WITH ONSHORE FLOW ALONG THE COAST AND
CLOUD COVER. SIDED WITH THE COOLER GUIDANCE AND WENT WITH HIGHS
MAINLY IN THE UPPER 60S TO THE LOWER 70S FOR NOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
* DRY WEATHER FRIDAY
* FRONTAL SYSTEM WILL BRING RAIN FOR THE
WEEKEND
* DRY...COOL WEATHER RETURNS EARLY NEXT WEEK
00Z MODELS ARE IN REMARKABLY GOOD AGREEMENT THROUGH THE LONG TERM
FORECAST. A WEAK COLD FRONT/AREA OF LOW PRESSURE MOVES THROUGH
SOUTHERN NEW ENGLAND THURSDAY NIGHT...BRINGING MORE SHOWERS TO THE
AREA. LOW PRESSURE MOVES THROUGH QUEBEC FRIDAY WITH A COLD FRONT
MOVING THROUGH THE REGION LATE FRIDAY NIGHT INTO EARLY SATURDAY.
LOW PRESSURE BUILDS OUT OF THE CAROLINAS SATURDAY AND MOVES
NORTHEASTWARD OVER CAPE COD AND INTO THE MARITIMES SUNDAY BRINGING
ANOTHER SHOT OF RAIN TO SOUTHERN NEW ENGLAND. COOL...DRY WEATHER
RETURNS AS HIGH PRESSURE BUILDS INTO NEW ENGLAND.
DETAILS...
THURSDAY NIGHT...AN AREA OF LOW PRESSURE MOVES OVER CAPE COD
BRINGING ANOTHER ROUND OF SHOWERS TO SOUTHERN NEW ENGLAND DURING THE
EARLY PART OF THE NIGHT. AFTER MIDNIGHT...ANY REMAINING SHOWERS AND
CLOUDS MOVE OUT...LINGERING ON THE EAST COAST THE LONGEST. THERE IS
SOME MARGINAL INSTABILITY SO THUNDER IS POSSIBLE...PARTICULARLY
BEFORE MIDNIGHT.
FRIDAY...DRY DAY EXPECTED AHEAD OF A COLD FRONT THAT WILL MOVE
THROUGH THE REGION FRIDAY NIGHT. THIS WILL OCCUR AS LOW PRESSURE
MOVES THROUGH QUEBEC. EXPECT TEMPERATURES TO BE WELL ABOVE NORMAL
WITH 850MB TEMPS IN THE 10 TO 12 DEGREE RANGE.
SATURDAY AND SUNDAY...LOW PRESSURE IN THE CAROLINAS SATURDAY WILL
MOVE NORTHEASTWARD OVER CAPE COD AND INTO THE MARITIMES SUNDAY.
THIS WILL BRING RAIN TO SOUTHERN NEW ENGLAND...PARTICULARLY SATURDAY
NIGHT AND SUNDAY. SOUTHWESTERLY FLOW AT THE MID AND UPPER LEVELS
WILL DRAW MOISTURE UP FROM THE GULF OF MEXICO. PWATS ARE HIGH...IN
THE INCH TO INCH AND A HALF RANGE. THIS WILL LEAD TO PERIODS OF
HEAVY RAIN.
MONDAY AND TUESDAY...HIGH PRESSURE BUILDS INTO THE REGION BRINGING
DRY...COOL WEATHER. TEMPERATURES WILL DROP SLIGHTLY BELOW NORMAL.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW... MODERATE CONFIDENCE. IFR/LIFR PERSISTS THROUGH MIDDAY
BEFORE IMPROVING TO MVFR CIGS THIS AFTERNOON. MORE CONFIDENT ON
RETURN TO IFR/LIFR THIS EVENING THROUGH THU MORNING.
KBOS TAF...MODERATE CONFIDENCE. CIGS WILL HANG AROUND HIGHER END
OF IFR /OVC009/ THROUGH MIDDAY BUT MVFR CIGS SHOULD PREVAIL.
KBDL TAF...MODERATE CONFIDENCE. CIGS MAY REMAIN IFR THROUGH
AFTERNOON /OVC008/ BUT CONFIDENCE IS HIGHER ON CIGS LIFTING TO
MVFR.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY... THURSDAY NIGHT...MODERATE
CONFIDENCE. MAINLY VFR. PERIODS OF MVFR/IFR IN -SHRA.
FRIDAY...HIGH CONFIDENCE. VFR.
SATURDAY AND SUNDAY...LOW TO MODERATE CONFIDENCE. PERIODS OF
MVFR/IFR IN RAIN/FOG...ESPECIALLY SATURDAY NIGHT AND SUNDAY.
&&
.MARINE...
HIGH CONFIDENCE THROUGH THURSDAY THAT WINDS AND SEAS WILL REMAIN
BELOW SCA THRESHOLDS WITH A RELATIVELY WEAK PRESSURE GRADIENT. MAIN
CONCERN FOR MARINERS WILL BE FOR AREAS OF FOG RESULTING IN POOR
VISIBILITIES...PARTICULARLY DURING THE OVERNIGHT THROUGH THE MID
MORNING HOURS.
OUTLOOK...THURSDAY NIGHT THROUGH SUNDAY...
WINDS AND SEAS REMAIN BELOW SCA CRITERIA THROUGH THE PERIOD. WINDS
INCREASE LATE SATURDAY NIGHT/EARLY SUNDAY MORNING AS A COLD FRONT
APPROACHES THE WATERS. SHOWERS/FOG MAY LIMIT VISIBILITIES AT TIMES
THROUGHOUT THE PERIOD. FRIDAY LOOKS TO BE THE ONLY DAY THAT THIS
DOES NOT OCCUR.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANK/RLG
NEAR TERM...JWD
SHORT TERM...FRANK
LONG TERM...RLG
AVIATION...JWD
MARINE...FRANK/RLG
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1027 AM EDT WED OCT 3 2012
.DISCUSSION...
FRONTALYSIS OCCURRING OVER THE ERN GOMEX THIS MORNING...DEEP
MOISTURE BAND ASSOCD WITH THE DISSIPATING FRONT WILL REMAIN
OVERHEAD. LATEST RAP ANALYSIS SHOWS THE ATLC RIDGE AXIS BEGINNING TO
NUDGE ITS WAY UP THE FL PENINSULA WITH A SLIGHTLY DRIER AND LESS
ENERGETIC AIRMASS IN TOW. MORNING RAOBS BEAR THIS OUT WITH PWATS OFF
THE KMFL/KEYW SOUNDINGS BTWN 1.5"-2.0"...INCREASING TO 2.0"-2.4" AT
KXMR/KTBW/KJAX. SFC DEWPOINTS REMAIN IN THE M70S ACRS THE CENTRAL
AND SOUTH PENINSULA...THINNER MID/UPR LVL CLOUDS OVER THE TREASURE
COAST HAVE ALLOWED TEMPS TO WARM INTO THE L/M80S WHILE THICKER
CLOUDS TO THE N ARE KEEPING TEMPS IN THE M/U70S.
WX ELEMENTS POINT TOWARD LOWER COVERAGE TODAY THAN IN RECENT DAYS.
THE NRN CWA WITH THE DEEPEST MOISTURE WILL SEE LIMITED SFC HEATING
AND DESTABILIZATION DUE TO THE THE MID/UPR LVL CLOUDS...WHILE DRIER
AND MORE STABLE AIR PUSHING INTO THE SRN CWA ALSO WILL RESULT IN
LOWER COVERAGE...ESPECIALLY AS ENHANCES SFC HEATING WILL PROMOTE THE
FORMATION OF THE EAST COAST SEA BREEZE. EARLY CONVECTION FIRING OVER
THE W FL COAST IS EMBEDDED WITHIN DEEP SRLY FLOW AND WILL LARGELY
MISS THE CWA...BUT DOES DISPLAY GREATER PRECIP POTENTIAL OVER THE
NRN CWA.
MID LVL LAPSE RATES HAVE STEEPENED SLIGHTLY...NOW RUNNING BTWN
5.0-6.0C/KM...WHILE H50 TEMPS HAVE COOLED TO BTWN -6C AND -7C. WHILE
THIS WILL PROMOTE HIGHER TSRA POTENTIAL...TOTAL LTG ACTIVITY OVER
THE PAST FEW DAYS HAS BEEN SO LOW THAT ANY INCREMENTAL INCREASES
STILL WILL RESULT IN ISOLD COVERAGE AT BEST. PREVAILING PRECIP WILL
BE LOW-TOPPED SHRAS.
H85-H70 THETA-E ANALYSIS SHOWS A MAX RUNNING PARALLEL TO THE I-4
CORRIDOR DECREASING TO A LCL MIN OVR THE FL STRAITS AND THE NRN
BAHAMAS. THIS LINES UP WELL WITH THE CURRENT POP CONFIG. TEMP/WIND
FCST LOOKS GOOD AS WELL GIVEN THE CURRENT TREND. WILL UPDATE FCST TO
REFRESH WORDING...NO SIG SUBSTANTIVE CHANGES NECESSARY.
&&
.AVIATION...
THRU 03/18Z...PREVAILING VFR...SFC WNDSHFT FM S TO E/SE AOB 12KTS
ALNG THE COAST S OF KMLB...CIGS AOA FL080 N OF KVRB-KFMY. BTWN
03/18Z-03/24Z...SCT/NMRS IFR SHRAS/ISOLD LIFR TSRAS ALL SITES WITH
HIGHEST POPS N OF THE I-4 CORRIDOR...SFC WNDSHFT FROM S TO E/SE AOB
12KTS BY 03/21Z INTERIOR SITES AND COASTAL SITES N OF KMLB. BTWN
04/00Z-04/03Z...SCT MVFR SHRAS/ISOLD IFR TSRAS. AFT
04/03Z...PREVAILING VFR WITH ISOLD MVFR SHRAS.
&&
.MARINE...
HI PRES RIDGE AXIS NUDGING NWD INTO CNTRL FL WILL GENERATE A GENTLE
TO MODERATE S/SWRLY BREEZE THRU MIDDAY. WINDS WILL BACK TO THE E/SE
BY LATE AFTN AS THE RIDGE AXIS CONTINUES TO BUILD NWD. LATEST BUOY
OBS SHOW SEAS RUNNING 2-3FT NEARSHORE AND 3-4FT OFFSHORE THIS
MORNING. LCL WIND WAVES STILL PREVAIL AT BUOY009 WITH DOMINANT WAVE
PDS ARND 4SEC. HOWEVER...OCNL OBS SHOW PDS ARND 10SEC WHILE OTHER
OFFSHORE BUOYS SHOW PDS UP TO 6-7SEC. FCST TREND LOOKS GOOD...NO SIG
CHANGES NECESSARY.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX.....LASCODY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1000 AM CDT WED OCT 3 2012
.DISCUSSION...
ISSUED 1000 AM CDT WED OCT 3 2012
LATEST OBSERVATIONS AND SATELLITE IMAGERY SHOWING SURFACE LOW NOW
CENTERED JUST NORTH OF KANKAKEE. FAIRLY SHARP CLEARING LINE
PERSISTING ALONG THE ILLINOIS/IOWA BORDER...BUT IS NOT MAKING ANY
EASTWARD PROGRESS. ANOTHER CLEARING LINE CENTERED ROUGHLY ALONG
I-64 IN SOUTH CENTRAL ILLINOIS IS MOVING NORTHWARD INTO THE
SOUTHEAST EDGE OF OUR FORECAST AREA. LAYER HUMIDITY PLOTS OFF THE
RAP MODEL SHOW THIS SOUTHERN CLEARING AREA CONTINUING TO MAKE SOME
NORTHWARD PROGRESS THROUGH THE DAY...WITH SKIES BECOMING PARTLY
SUNNY SOUTH OF I-70 BY EARLY AFTERNOON. HOWEVER...THE REMAINDER OF
THE FORECAST AREA SHOULD REMAIN GENERALLY CLOUDY...WITH SOME THIN
SPOTS IN THE OVERCAST HERE AND THERE. RAP AND HRRR MODELS
CONTINUING TO HOLD ON TO SOME SCATTERED SHOWERS THROUGH THE
AFTERNOON.
HAVE SENT SOME UPDATED ZONES/GRIDS...MAINLY TO UPDATE HOURLY TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 640 AM CDT WED OCT 3 2012
CEILINGS BELOW 1K FT AND VSBYS BELOW 3 MILES OVER EASTERN IL TAF
SITES OF BMI...DEC AND CMI (WHERE DENSE FOG AT CMI WITH VSBYS AS
LOW AS 1/4-1/2 MILE) WILL GRADUALLY LIFT TO MVFR LATE THIS MORNING.
WESTERN TAF SITES OF PIA AND SPI WILL SEE MVFR CEILINGS 2-3K FT
INTO MID MORNING AND LIFT TO 6-8K FT BY LATE MORNING. SPOTTY LIGHT
RAIN SHOWERS AND PATCHY DRIZZLE WILL OCCUR TODAY ACROSS CENTRAL IL
DUE TO NEARBY STRONG UPPER LEVEL TROF OVER IL. WEAK LOW PRESSURE
1013 MB NEAR PONTIAC WILL CONTINUE SLOW NORTHWARD DRIFT INTO NE IL
TODAY WHILE 570 DM 500 MB LOW NEAR ST LOUIS AND 571 DM 500 MB LOW
OVER NORTH LA TO SHIFT SLOWLY EAST TO THE IL/IN BORDER BY 06Z/1 AM
TONIGHT AND INTO EASTERN INDIANA AND CENTRAL KY BY 12Z/7 AM THU.
EXPECT CLOUDS TO SCATTER OUT FROM WEST TO EAST DURING THIS EVENING
AS UPPER LEVEL TROF AXIS SHIFTS EASTWARD. SSW WINDS 5-10 KTS TODAY
WILL BE SOUTH 4-8 KTS TONIGHT AND INCREASE DURING THU MORNING AS A
STRONG COLD FRONT FROM NW MN INTO CENTRAL SD MOVES SE TO THE IA/IL
BORDER BY 18Z/1 PM THU.
KH
&&
.PREV DISCUSSION...
ISSUED 240 AM CDT WED OCT 3 2012
SHORT TERM...TODAY THROUGH FRIDAY
PERSISTENT UPPER TROUGH WILL REMAIN IN PLACE FROM THE SOUTHERN
GREAT LAKES TO THE WESTERN GULF OF MEXICO TODAY...ENSURING A
CONTINUATION OF MOSTLY CLOUDY CONDITIONS. WITH WEAK SURFACE LOW
PRESSURE MEANDERING NORTHWARD ACROSS EAST-CENTRAL ILLINOIS...MAY
SEE A FEW SHOWERS SCATTERED AROUND THE AREA AS WELL. AS HAS BEEN
THE CASE FOR THE PAST COUPLE OF DAYS...THE DEEPEST MOISTURE AND
THUS BEST CHANCE FOR RAIN WILL BE CONFINED TO THE EASTERN KILX
CWA. AS A RESULT...WILL FOCUS HIGHEST POPS EAST OF I-55...TAPERING
DOWN TO JUST SLIGHT CHANCES FURTHER WEST IN THE ILLINOIS RIVER
VALLEY. TEMPERATURES WILL BE A BIT TRICKY TODAY...AS THEY WILL BE
HIGHLY DEPENDENT UPON HOW MUCH SUNSHINE OCCURS. 07Z/2AM SATELLITE
IMAGERY INDICATES THE ENTIRE AREA IS CURRENTLY BLANKETED BY CLOUD
COVER...AND WITH LOW PRESSURE SHIFTING ONLY VERY SLOWLY
NORTHWARD...THINK MOSTLY CLOUDY SKIES WILL PREVAIL THROUGHOUT THE
DAY. MAY SEE SOME BREAKS IN THE OVERCAST WEST OF THE ILLINOIS
RIVER FROM TIME TO TIME...AS WELL AS ALONG/SOUTH OF I-70 AS DRY
SLOT CONTINUES TO WRAP N/NW AROUND UPPER TROUGH. RESULTING HIGHS
WILL MAINLY BE IN THE LOWER 70S...WITH COOLEST READINGS IN THE
MIDDLE TO UPPER 60S ACROSS THE NE CWA AROUND CHAMPAIGN WHERE CLOUD
COVER WILL BE MOST PERSISTENT. UPPER TROUGH WILL FINALLY GET
EJECTED NORTHEASTWARD TONIGHT...IN RESPONSE TO NORTHERN STREAM
WAVE DIGGING INTO THE NORTHERN PLAINS/UPPER MIDWEST. WILL LINGER
LOW CHANCE POPS FOR SHOWERS INTO THE EVENING HOURS...BEFORE GOING
DRY ACROSS THE BOARD AFTER MIDNIGHT.
THURSDAY WILL BE THE WARMEST DAY OF THE FORECAST PERIOD...AS
STRONG SOUTHERLY FLOW AHEAD OF THE NEXT APPROACHING COLD FRONT
HELPS BOOST HIGH TEMPS INTO THE UPPER 70S AND LOWER 80S. COLD
FRONT IS STILL EXPECTED TO PUSH INTO ILLINOIS DURING THE
AFTERNOON...WITH MODEL CONSENSUS PLACING IT FROM JUST SOUTH OF
CHICAGO TO NEAR SAINT LOUIS BY EARLY EVENING. ALL MODELS CONTINUE
TO SUGGEST ANY PRECIP THAT DEVELOPS WILL BE PRIMARILY
POST-FRONTAL...MEANING MUCH OF CENTRAL ILLINOIS WILL REMAIN DRY
THROUGH THE ENTIRE DAY. WILL THEREFORE CONFINE POPS TO LOCATIONS
ALONG/WEST OF I-55 THURSDAY AFTERNOON...WITH DRY WEATHER
PERSISTING FURTHER EAST. RAIN CHANCES WILL INCREASE THURSDAY NIGHT
AS THE FRONT MOVES THROUGH THE REGION. GIVEN NARROW CORRIDOR OF
INSTABILITY AND INCREASING WIND-SHEAR ALONG/BEHIND THE
BOUNDARY...HAVE INCLUDED ISOLATED THUNDER THURSDAY AFTERNOON AND
EVENING.
FRONT WILL SINK INTO THE OHIO RIVER VALLEY ON FRIDAY...HOWEVER
UPPER-WAVE MOVING ALONG THE BOUNDARY WILL BRING A PERIOD OF
OVERRUNNING RAIN TO PARTS OF CENTRAL AND SOUTHEAST ILLINOIS
FRIDAY/FRIDAY NIGHT. HIGHEST RAIN CHANCES THROUGH THIS PERIOD WILL
BE ACROSS THE SOUTHERN CWA...GENERALLY ALONG/SOUTH OF I-70...WITH
RAIN CHANCES STEADILY DECREASING FURTHER NORTH. IN FACT...AREAS
ALONG AND NORTH OF A CANTON TO BLOOMINGTON-NORMAL LINE MAY REMAIN
COMPLETELY DRY ON FRIDAY. NORTHERLY WINDS BEHIND THE FRONT WILL
BRING SHARPLY COOLER CONDITIONS INTO THE REGION FOR THE END OF THE
WEEK...WITH HIGH TEMPS ON FRIDAY REMAINING IN THE 50S.
LONG TERM...SATURDAY THROUGH TUESDAY
ONCE UPPER WAVE TRACKS OFF TO THE EAST...FRONT WILL GET PUSHED
FURTHER SOUTH OVER THE WEEKEND...RESULTING IN COOL/DRY CONDITIONS
FOR BOTH SATURDAY AND SUNDAY. AS HIGH PRESSURE BUILDS INTO THE
REGION...CLEAR SKIES AND LIGHT WINDS WILL ALLOW OVERNIGHT LOW
TEMPS TO DROP INTO THE LOWER TO MIDDLE 30S BOTH DAYS. AFTER
THAT...SOUTHERLY RETURN FLOW ON THE BACK SIDE OF THE DEPARTING
HIGH WILL SIGNAL A WARMING TREND EARLY NEXT WEEK...WITH HIGH TEMPS
CLIMBING BACK INTO THE MIDDLE 60S BY TUESDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
901 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* VARIABLE WINDS BECOMING SOUTHERLY LATER THIS AFTERNOON.
* IFR CEILINGS FOR A GOOD PORTION OF TODAY...BEFORE SLOWLY RISING
TO MVFR LATER THIS AFTERNOON.
* SHOWERS/AREAS OF DRIZZLE TODAY...POSSIBLY REDUCING VIS TO IFR
THIS MORNING. CMS
//DISCUSSION...UPDATED 12Z...
CONDITIONS HAVE QUICKLY DETERIORATED THIS MORNING WITH THE ARRIVAL
OF THIS WEAK LOW PRESSURE AND EXPANSIVE AREA OF LOW LEVEL
MOISTURE. IFR CEILINGS BEING REPORTED ACROSS ORD/MDW/GYY
AREAS...WITH THESE LOW CLOUDS TO AFFECT DPA IN THE NEXT HOUR AND
RFD TO REMAIN VFR THROUGH THE FORECAST PERIOD. HAVE CONTINUED
PESSIMISTIC TRENDS WITH LOW CEILINGS TODAY...KEEPING IFR
CONDITIONS OVERHEAD FOR MUCH OF THE DAY. SOME UNCERTAINTY AS TO
THE OVERALL TREND WITH THE CEILINGS TODAY REMAINS...AS IT IS
CONCEIVABLE THAT THESE IFR CONDITIONS COULD LINGER EVEN INTO THE
EARLY EVENING BEFORE LOW/MID LEVEL FLOW INCREASES AND REALLY HELPS
STEER THIS MOISTURE OUT OF THE TERMINAL AREAS. ALTHOUGH AT THIS
TIME...HAVE NOT GONE THAT FAR WITH THE FORECAST AND BRING CEILINGS
UP TO MVFR CONDITIONS LATER THIS AFTERNOON AND THEN EVENTUALLY
SCATTERING THEM OUT TONIGHT. FOG/DRIZZLE WILL ALSO CONTINUE FOR A
GOOD PORTION OF TODAY...WITH VIS RESTRICTIONS EXPECTED INTO THIS
AFTERNOON. WITH THE WEAKENING LOW CENTER MOVING
OVERHEAD...VARIABLE WINDS WILL BE OBSERVED FOR MOST OF TODAY
BEFORE SURFACE PATTERN ALLOWS FOR WINDS TO BECOME MORE ORGANIZED
OUT OF THE SOUTH. VFR CONDITIONS EXPECTED THURSDAY MORNING BUT
WITH SOUTH/SOUTHWEST WINDS/GUSTS REALLY INCREASING BY MID DAY.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH CEILING TRENDS TODAY...WITH LOW
MEDIUM CONFIDENCE AS TO THE EXACT LENGTH OF PERIOD WHICH THE IFR
CEILINGS WILL REMAIN OVER THE TERMINALS.
* MEDIUM HIGH CONFIDENCE WITH SHOWERS/DRIZZLE AND VIS TRENDS. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE SHOWERS AND SLIGHT CHANCE TS...OTHERWISE
VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
700 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* VARIABLE WINDS BECOMING SOUTHERLY LATER THIS AFTERNOON.
* IFR CEILINGS FOR A GOOD PORTION OF TODAY...BEFORE SLOWLY RISING
TO MVFR LATER THIS AFTERNOON.
* FOG/DRIZZLE WITH VIS OF 3-5SM EXPECTED TODAY...AND BRIEF PERIODS
OF VIS AROUND 2SM THIS MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
CONDITIONS HAVE QUICKLY DETERIORATED THIS MORNING WITH THE ARRIVAL
OF THIS WEAK LOW PRESSURE AND EXPANSIVE AREA OF LOW LEVEL
MOISTURE. IFR CEILINGS BEING REPORTED ACROSS ORD/MDW/GYY
AREAS...WITH THESE LOW CLOUDS TO AFFECT DPA IN THE NEXT HOUR AND
RFD TO REMAIN VFR THROUGH THE FORECAST PERIOD. HAVE CONTINUED
PESSIMISTIC TRENDS WITH LOW CEILINGS TODAY...KEEPING IFR
CONDITIONS OVERHEAD FOR MUCH OF THE DAY. SOME UNCERTAINTY AS TO
THE OVERALL TREND WITH THE CEILINGS TODAY REMAINS...AS IT IS
CONCEIVABLE THAT THESE IFR CONDITIONS COULD LINGER EVEN INTO THE
EARLY EVENING BEFORE LOW/MID LEVEL FLOW INCREASES AND REALLY HELPS
STEER THIS MOISTURE OUT OF THE TERMINAL AREAS. ALTHOUGH AT THIS
TIME...HAVE NOT GONE THAT FAR WITH THE FORECAST AND BRING CEILINGS
UP TO MVFR CONDITIONS LATER THIS AFTERNOON AND THEN EVENTUALLY
SCATTERING THEM OUT TONIGHT. FOG/DRIZZLE WILL ALSO CONTINUE FOR A
GOOD PORTION OF TODAY...WITH VIS RESTRICTIONS EXPECTED INTO THIS
AFTERNOON. WITH THE WEAKENING LOW CENTER MOVING
OVERHEAD...VARIABLE WINDS WILL BE OBSERVED FOR MOST OF TODAY
BEFORE SURFACE PATTERN ALLOWS FOR WINDS TO BECOME MORE ORGANIZED
OUT OF THE SOUTH. VFR CONDITIONS EXPECTED THURSDAY MORNING BUT
WITH SOUTH/SOUTHWEST WINDS/GUSTS REALLY INCREASING BY MID DAY.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM HIGH CONFIDENCE WITH CEILING TRENDS TODAY...WITH LOW
MEDIUM CONFIDENCE AS TO THE EXACT LENGTH OF PERIOD WHICH THE IFR
CEILINGS WILL REMAIN OVER THE TERMINALS.
* MEDIUM HIGH CONFIDENCE WITH FOG/DRIZZLE AND VIS TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE SHOWERS AND SLIGHT CHANCE TS...OTHERWISE
VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
546 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT NORTHEAST WINDS BECOMING VARIABLE THROUGH MUCH OF THE
MORNING.
* MVFR CEILINGS LOWERING TO IFR CEILINGS BY 12/13Z THIS
MORNING...AND LINGERING THROUGH THE REMAINDER OF THE MORNING.
* LIGHT SHOWERS/FOG MOVING ACROSS THE TERMINALS THIS MORNING.
RODRIGUEZ
//DISCUSSION...UPDATED 09Z...
HAVE MADE SIGNIFICANT CHANGES TO THE TAF WITH THIS UPDATE...GOING
MORE PESSIMISTIC WITH THE CEILINGS THIS MORNING. GOOD SWATH OF
MVFR/IFR CEILINGS CURRENTLY RESIDE JUST SOUTH OF THE TERMINALS AND
AS THIS WEAK LOW CONTINUES NORTH...DONT SEE ANY REASON WHY THESE
LOW CEILINGS WONT MOVE OVERHEAD. SO HAVE STARTED THE TAFS WITH
MVFR CEILINGS BUT HAVE CONDITIONS QUICKLY DETERIORATING TO IFR
CEILINGS AROUND THE 12/13Z TIME FRAME. EXPECT THESE LOW CLOUDS TO
LINGER THROUGH THE REMAINDER OF THE MORNING...BEFORE SLOWLY
LIFTING THIS AFTERNOON.
LIGHT NORTHEAST WINDS WILL PERSIST BEFORE BECOMING MORE VARIABLE
AS THE WEAKENING LOW CENTER MOVES OVERHEAD. THEN A RETURN TO LIGHT
SOUTHERLY WINDS WILL BE OBSERVED LATER THIS AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE WITH CEILING TRENDS AS WELL AS IFR TIMING
THROUGH THIS MORNING.
* MEDIUM CONFIDENCE WITH SHOWER/FOG TRENDS.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...CHANCE SHOWERS...SLIGHT CHANCE TS.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TRS
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON MS
949 AM CDT WED OCT 3 2012
.UPDATE...POPS WERE INCREASED OVER SOUTHERN AND EASTERN AREAS FOR
THIS AFTERNOON IN LIEU OF PROGGED 500-800 J/KG ML CAPE UNDER DECENT
LAPSE RATES AS A WEAK LOW-LVL SOUTHERN FETCH MOISTURE TOUNGE FEEDS
INTO THE AREA. IT COULD BE CONCEIVEABLE THAT ONE OR TWO OF THE ISO
TSTORMS THIS AFTN COULD BE STRONG WITH SUCH COOL TEMPS ALOFT AND
DECENT BL HEATING. STRONG STORM RISKS WILL BE GUSTY WINDS TO 40 MPH
AND SOME SMALL HAIL. WILL PLACE STRONG STORM WORDING IN HWO FOR THIS
UPDATE.
ACTIVITY WILL WANE NEAR SUNSET AS INSTABILITY DECREASES AND VORT MAX
SHIFTS EAST. MINOR TWEAKS TO HOURLY WX ELEMENTS TO MATCH LATEST
TRENDS WERE ALSO MADE. UPDATED PRODUCTS ARE OUT AND AN UPDATED
AVIATON DISCUSSION CAN BE FOUND DIRECTLY BELOW. /ALLEN/
&&
.AVIATION...A ROBUST UPPER LOW MOVING OVER THE REGION TODAY SHOULD
RESULT IN SCATTERED CU DEVELOPMENT AS THE DAY PROGRESSES...WITH
BASES GENERALLY FROM 3 TO 6 KFT. SOME ISOLATED SHOWER AND
THUNDERSTORM DEVELOPMENT WILL ALSO BE POSSIBLE IN THE
AFTERNOON...BUT MAINLY ALONG AND SOUTHEAST OF THE NATCHEZ TRACE
CORRIDOR. OTHERWISE...WINDS WILL MAINLY BE FROM THE SOUTH AND NOT
TOO STRONG (LESS THAN 15 MPH). SHOWERS SHOULD END THIS EVENING WITH
A CHANCE OF PATCHY FOG AND/OR LOW CLOUD DEVELOPMENT LATE TONIGHT
INTO EARLY THURSDAY MORNING. DUE TO THE LATTER POTENTIAL MANY SITES
CAN EXPECT A DECENT POSSIBILITY OF TEMPORARY MVFR FLIGHT CATS
BETWEEN 5 AM AND 9 AM TOMORROW MORNING. /BB/
&&
.PREV DISCUSSION... /ISSUED 417 AM CDT WED OCT 3 2012/
SHORT TERM...IR IMAGERY THIS MORNING CLEARLY DEPICTS THE CLOSED
UPPER LOW OVER NORTHERN LA...WITH AREA RADARS SHOWING A CLUSTER OF
SHOWERS AND THUNDERSTORMS OVER CATAHOULA AND CONCORDIA PARISH.
SURFACE ANALYSIS SHOWS THESE STORMS DEVELOPING ALONG A WEAK SURFACE
BOUNDARY DRAPED ROUGHLY FROM MOBILE TO JUST NORTH OF ALEXANDRIA. THE
LATEST HRRR RUN VERIFIED THIS CONVECTION ALMOST PERFECTLY...AND
SUGGESTS THESE STORMS WILL BEGIN TO DIMINISH BY SUNRISE AS THEY
DRIFT NORTH. THE QUESTION THEN BECOMES...WHAT KIND OF CHANCE DO WE
HAVE FOR SEEING ADDITIONAL SHOWERS AND STORMS LATER THIS AFTERNOON?
NWP GUIDANCE INDICATES THE UPPER LOW WILL BEGIN TO OPEN AND LIFT
NORTHWARD TODAY AS THE UPPER JET STRENGTHENS OVER AL...WITH THE
WEAKENING S/WV SHIFTING EAST ACROSS THE CWA THROUGH THE DAY. FORCING
FOR ASCENT IN ADVANCE OF THE WAVE WILL BE RATHER POTENT ACROSS
SOUTHERN/SOUTHEASTERN AREAS TODAY...AND COUPLED WITH /1.THE
AFOREMENTIONED BOUNDARY LIFTING NORTHWARD INTO SOUTHERN PORTIONS OF
THE CWA BY LATE MORNING AND /2.SURFACE HEATING RAISING SBCAPE VALUES
ACROSS SOUTHERN/SOUTHEASTERN AREAS INTO THE 600-800J/KG RANGE/ I
THINK THE INGREDIENTS WILL BE SUFFICIENT FOR AT LAST ISOLATED
CONVECTIVE DEVELOPMENT. BEST GUESS RIGHT NOW IS FOR THIS ACTIVITY TO
START ACROSS SOUTHERN ZONES AROUND MID DAY...DRIFTING NORTHWARD/
NORTHEASTWARD WITH ADDITIONAL ISOLATED DEVELOPMENT FURTHER NORTH AND
EAST AS THE DAY WEARS ON. A COMBINATION OF SETTING SUN AND THE BEST
LIFT PUSHING EAST SHOULD BRING THIS ALL TO AN END BY EARLY EVENING.
BASED ON CONVECTIVE PARAMETERS OFFERED BY THE MORE REASONABLE
LOOKING 00Z GFS/ECMWF IT DOESN`T APPEAR SEVERE STORMS WILL BE A HUGE
CONCERN...BUT GIVEN RATHER COLD TEMPS ALOFT I COULD SEE ONE OR TWO
BECOMING STRONG ENOUGH TO POSE A 40 MPH WIND GUST AND SMALL HAIL
RISK.
ONCE THIS ALL CLEARS OUT THE FORECAST BECOMES RATHER UNEVENTFUL AS A
ZONAL UPPER FLOW PATTERN TAKES SHAPE ACROSS THE SOUTHEASTERN STATES
AND SURFACE RIDGING NOSES IN FROM THE EAST. SKIES SHOULD REMAIN
MOSTLY CLEAR THROUGH THE END OF THE WEEK ACCOMPANIED BY DAYTIME
TEMPS CLIMBING BACK ABOVE NORMAL BY TOMORROW WITH HIGHS IN THE MID
80S. LOWS TONIGHT AND TOMORROW NIGHT WILL COME IN MID-UPPER 50S FOR
MOST AREAS. /BK/
LONG TERM...THE NEXT SURFACE BOUNDARY BEGINS TO MOVE INTO NRN MS
FRIDAY NIGHT. THE GFS IS ONCE AGAIN SHOWING A FASTER SWD PROGRESSION
THAN THE EURO...THE LATEST EURO COMING IN SLIGHTLY SLOWER THAN IT
WAS YESTERDAY. THE EURO MOVES THE COLD FRONT JUST INTO THE NWRN
CORNER OF THE FORECAST AREA BY EARLY SATURDAY AFTERNOON WHILE THE
GFS BRINGS IT INTO THE VICINITY OF THE NATCHEZ TRACE. SLOWER
PROGRESSION NOTWITHSTANDING...MODELS ARE IN AGREEMENT THAT THE FRONT
WILL USHER A COLD AIR MASS INTO THE FORECAST AREA WITH SINGLE DIGIT
850 MB TEMPS ACROSS MOST OF THE AREA FOR SUNDAY THROUGH MONDAY.
MODERATION OF TEMPERATURES BEGINS TUESDAY WHEN THE SURFACE HIGH
CENTER LIFTS TO THE NE OF THE AREA AND 850 MB W/SWLY FLOW RETURNS.
THE AIR MASS WILL REMAIN DRY AHEAD OF THE BOUNDARY. LITTLE IN THE
WAY OF LOW LEVEL CONVERGENCE IS EXPECTED ALONG THE FRONT AND LOW
LEVEL/850 MB RIDGING WILL HOLD STEADY AS IT APPROACHES. BETTER UPPER
LEVEL FORCING IS EXPECTED TO THE REAR OF THE FRONT IN RESPONSE TO A
BROAD UPPER TROUGH THAT WILL DIG INTO THE ERN U.S...A HEALTHY
SHORTWAVE PIVOTING INTO THE MID/UPPER MS VALLEY SATURDAY NIGHT.
DUE TO THE SLOWER EURO AND THE SLOWER ADVANCE OF THE GFS QPF
FIELD...MEX POPS HAVE BEEN CUT SLIGHTLY FOR FRIDAY NIGHT. HAVE KEPT
THE VERY LOW RAIN CHANCES PAINTED FOR SUNDAY/SUNDAY NIGHT AS A
SECOND UPPER WAVE DIGS INTO THE LONG WAVE TROUGH. HAVE ALSO
INCREASED SATURDAY HIGHS A FEW DEGREES OVER MEX NUMBERS IN LIGHT OF
THE POTENTIAL FOR SLOWER FRONTAL PROGRESSION BUT NOT AS MUCH AS THE
EURO WHICH IS UP TO TEN DEGREES WARMER IN DELTA REGIONS THAN THE MEX
FOR SATURDAY AFTERNOON. ALSO DECREASED SUNDAY HIGHS A FEW DEGREES IN
THE NORTH TO KEEP THOSE AREAS SLIGHTLY COOLER THAN AREAS FARTHER
SOUTH AND SLOWED THE WARM UP THROUGH MONDAY AND TUESDAY SLIGHTLY.
&&
.AVIATION...
CLR SKIES/LGT WINDS ALLOWING MVFR VSBY IN FOG TO DEVELOP
AT SEVERAL SITES THIS MORNING...AND WOULD NOT BE SURPRISED TO SEE
IFR VSBY OFF AND ON THROUGH ~13Z BEFORE THINGS TREND VFR. VFR CONDS
WILL THEN PREVAIL THRU THE DAY AND INTO THE EVENING BEFORE A RETURN
OF MVFR VSBY BECOMES PSBL AT MOST SITES 07-13Z TOMORROW. THERE`S A
CHANCE ISOLD SHWRS/TSRA WILL DEVELOP ACROSS SRN/SERN MS THIS AFTN AS
AN UPPER DISTURBANCE PASSES. CALM SFC WINDS THIS MORNING BECMG SRLY
5-8KTS THIS AFTN. /BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 81 56 85 56 / 19 3 2 7
MERIDIAN 82 52 85 51 / 21 5 2 7
VICKSBURG 81 55 86 55 / 15 3 2 7
HATTIESBURG 84 57 87 57 / 23 8 3 4
NATCHEZ 81 56 85 57 / 20 3 2 6
GREENVILLE 80 57 86 58 / 5 3 2 7
GREENWOOD 80 55 86 56 / 17 3 2 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1015 AM EDT WED OCT 3 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY...BRINGING
SEASONABLY WARM TEMPERATURES TO THE OHIO VALLEY TODAY AND THURSDAY.
A COLD FRONT WILL PUSH THROUGH THE AREA ON FRIDAY. THIS WILL BRING
COOLER TEMPERATURES AND A GOOD CHANCE FOR RAIN FRIDAY THROUGH
SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KILN 03.12Z RAOB INDICATED A RATHER MOIST/MIXED BOUNDARY LAYER UP
TO ABOUT 875MB. VIS SATELLITE LOOP THIS MORNING HAS A RATHER
WIDESPREAD BKN/OVC STRATOCUMULUS FIELD NORTH OF THE OHIO
RIVER...AND DEEP ENOUGH NORTHWEST OF DAYTON /2KM LAYER/ TO SUPPORT
A LITTLE DRIZZLE WHICH FAA DAYTON RADAR /TDAY/ HAS PICKED UP ON
NICELY. RAP MODEL HAS PICKED UP ON THIS DEEPER MOISTURE AND LIFTS
IT NWWRD IN TIME AND ANY LIGHT DRIZZLE/VERY LIGHT RAIN SHOULD END
BY NOON IN THE NORTHWEST. LOW CLOUDS IN THE WEST/NORTHWEST WILL BE
STUBBORN AND MAY NEED TO UPDATE AND LOWER HIGH TEMPS IF BREAKS
DON/T BECOME MORE WIDESPREAD OVER THE NEXT FEW HOURS. IN THE
SOUTH/EAST...WILL CONTINUE A SLOW TREND OF DECREASING CLOUDS.
THESE AREAS MAY ALSO BE TOO WARM IN GIVEN FORECAST AND WILL TAKE A
LOOK AT 15Z OBS WITH A NOTION OF DROPPING TEMPS A BIT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
CLEARING SKIES WILL CONTINUE TO SPREAD NORTHWARD THIS EVENING AND
INTO THE OVERNIGHT HOURS. THIS WILL ALLOW TEMPERATURES TO COOL
INTO THE LOWER 50S FOR THE MOST PART. SOME PATCHY VALLEY FOG WILL
BE POSSIBLE WHERE CLEAR SKIES ARE PREVALENT THROUGHOUT THE NIGHT.
THE UPPER LOW THAT BEGAN MOVING OUT OF THE UPPER MISSISSIPPI
VALLEY TODAY...WILL SLIDE ACROSS THE OHIO VALLEY ON THURSDAY. A
FEW MODELS HINT AT A COUPLE OF SHOWERS DEVELOPING DURING THE DAY
THURSDAY ASSOCIATED WITH THIS TROUGH. HAVE OPTED TO CONTINUE A DRY
FORECAST FOR THE TIME BEING DUE TO THE LOW END CHANCES FOR THESE
SHOWERS. OTHERWISE...THURSDAY LOOKS TO BE PARTLY CLOUDY AND
SEASONABLY WARM.
A DEEP AND VERTICALLY STACKED LOW CENTERED ACROSS THE CENTRAL
US/CANADIAN BORDER WILL SLIDE EASTWARD ON THURSDAY NIGHT. A
SURFACE COLD FRONT EXTENDING FROM THIS LOW ACROSS MICHIGAN
SOUTHWESTWARD THROUGH MISSOURI WILL PUSH EASTWARD AND INTO OUR
WESTERN ZONES FRIDAY MORNING...AND ACROSS THE REMAINDER OF OUR ZONES
DURING THE DAY FRIDAY. THE LAGGING FRONTAL BOUNDARY ALOFT WILL BE A
SOURCE FOR CONVERGENCE AS PERIODIC SHORTWAVES RIDE EAST NORTHEAST
ALONG IT. THIS WILL CREATE PERIODS OF ENHANCED CHANCES FOR SHOWERS
STARTING FRIDAY MORNING AND EXTENDING THROUGH SATURDAY NIGHT. EACH
MODEL VARIES ON THEIR TIMING OF THE PASSAGE OF THESE FEATURES.
NOTABLY...THE STATISTICAL MODELS FAIL TO SHOW FOCUSED QPF FIELDS
DUE TO THE TIMING SPREADS...WHEREAS THE OPERATIONAL MODELS SUCH AS
THE NAM AND GFS SHOW THE INDIVIDUALLY FOCUSED PERIODS OF
PRECIPITATION. HOWEVER...DUE TO THE TIMING DIFFERENCES...THE POP
FIELD STARTS ITS FOCUS ACROSS THE NORTH AND GRADUALLY WORKS ITS
WAY SOUTH ACROSS OUR FORECAST AREA. THE GRADUAL SOUTHWARD SHIFT
WILL LIKELY HOLD TRUE FROM FRIDAY THROUGH SATURDAY NIGHT AS EACH
SUBSEQUENT WAVE FORCES THE COLD FRONT ALOFT FARTHER SOUTH.
THE QPF FORECAST WAS A BLEND OF THE GFS/NAM/ECMWF WHICH YIELDS AND
AREA AVERAGE OF ABOUT A HALF TO THREE QUARTERS OF AN INCH FRIDAY
MORNING THROUGH SATURDAY NIGHT.
WITH THE SURFACE COLD FRONT PUSHING THROUGH FRIDAY MORNING INTO
THE DAY FRIDAY...LOW LEVEL COLD ADVECTION WILL BE OCCURRING UNDER
CLOUDY SKIES FOR THE ENTIRE TIME FROM FRIDAY AFTERNOON THROUGH
SATURDAY NIGHT. THIS WILL RESULT IN WELL BELOW NORMAL HIGH
TEMPERATURES ON FRIDAY FOR ALL EXCEPT PERHAPS THE SOUTHEASTERN
ZONES. ON SATURDAY...RAIN COOLED...CLOUDY AND POST FRONTAL LOW
LEVELS WILL LIKELY YIELD HIGH TEMPERATURES MORE THAN 10 DEGREES
BELOW NORMAL.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
MUCH COOLER TEMPERATURES WILL BE IN PLACE ACROSS THE AREA SUNDAY
WITH HIGHS ONLY IN THE 50S. TEMPERATURES SUNDAY NIGHT INTO MONDAY
MORNING ARE EXPECTED TO DROP INTO THE LOW TO MIDDLE 30S. WITH
MOSTLY CLEAR SKIES...LIGHT WINDS...AND A COOL AIRMASS IN PLACE
OVERNIGHT SUNDAY NIGHT...THERE IS THE POTENTIAL FOR AREAS OF FROST
ACROSS THE REGION. SOUTHERLY FLOW DEVELOPS AND INCREASES ACROSS
THE AREA ON MONDAY ALLOWING TEMPERATURES TO REBOUND INTO THE UPPER
50S TO AROUND 60 BY MONDAY AFTERNOON. TEMPERATURES WILL BE WARMER
ON TUESDAY ACROSS THE AREA AS SOUTHERLY FLOW CONTINUES WITH HIGH
TEMPERATURES IN THE 60S.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
VARIABLE CIGS ARE PERSISTING ACROSS THE AREA THIS MORNING WITH THE
GENERAL TREND FOR MORE WIDESPREAD MVFR CIGS ACROSS THE WEST. THIS
IS CLOSER TO THE REMNANT WEAKENING SURFACE LOW OVER WESTERN
INDIANA THAT IS FORECAST TO CONTINUE TO WEAKEN AS IT LIFTS NORTH
THROUGH THIS AFTERNOON. THIS WILL ALLOW FOR DRIER AIR TO WORK IN
ACROSS THE AREA FROM THE SOUTH THROUGH THE DAY. FAIRLY GOOD 925
MB DRYING WILL PUSH UP INTO OUR AREA THROUGH THE MORNING HOURS.
THIS SHOULD ALLOW FOR THE MVFR CIGS TO LIFT UP INTO A VFR CU FIELD
BY THIS AFTERNOON...BEFORE SCATTERING OUT LATER THIS AFTERNOON.
EXPECT MOSTLY CLEAR SKIES OVERNIGHT WITH PERHAPS AN INCREASE IN
SOME MID LEVEL CLOUDS LATE TONIGHT INTO EARLY THURSDAY AS A
WEAKENING MID/UPPER LEVEL TROUGH APPROACHES FROM THE WEST.
.OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE FRIDAY NIGHT
AND SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...BINAU
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1010 AM EDT WED OCT 3 2012
.SYNOPSIS...
AN OCCLUDED FRONT OVER CENTRAL PENNSYLVANIA WILL DRIFT SLOWLY EAST
TODAY. A FEW WEAK WAVES OF LOW PRESSURE WILL RIPPLE NORTH ALONG THIS
BOUNDARY THIS AFTERNOON INTO EARLY THURSDAY...BRINGING SCATTERED
SHOWERS TO THE REGION. WARMER THAN NORMAL TEMPERATURES ARE IN STORE
FOR TODAY THROUGH FRIDAY. A STRONG COLD FRONT WILL PUSH ACROSS THE
OHIO VALLEY AND GREAT LAKES REGION FOR FRIDAY AND SATURDAY...AND
WILL BRING THE NEXT CHANCE FOR SHOWERS FOLLOWED BY MUCH BELOW NORMAL
TEMPERATURES BY SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
AREAS OF FOG ARE DISSIPATING...WITH CLOUD BASES LIFTING QUICKLY THIS
MORNING.
HIGH PWAT AIR CONTINUING TO STREAM NORTH INTO THE REGION...ALL THE
WAY FROM THE GOMEX...WILL BRING SCATTERED AFTERNOON SHOWERS /AND
EVEN A FEW LOW-TOPPED TSRA NEAR AND TO THE EAST OF THE SUSQ
VALLEY/.
COSPA AND 12Z NAM DATA SHOWS MINIMAL CHCS FOR PRECIP TODAY.
HOWEVER...LATEST RAP INDICATES AN AREA OF LIGHT SHOWERS DRIFTING NE
ACROSS THE ENTIRE CWA VERY LATE THIS MORNING THROUGH THE AFTERNOON
HOURS. REGIONAL RADAR MOSAIC AND SFC OBS SHOW SOME OF THESE -SHRA
ALREADY SPREADING NNE FROM NRN VA...AND THE MD PANHANDLE INTO THE
LAUREL HIGHLANDS.
AS SIGNIFICANT BREAKS IN THE STRATO/ALTOCU CLOUD LAYER DEVELOP
DURING THE MIDDAY AND AFTERNOON HOURS...ML CAPE WILL INCREASE TO
BETWEEN 500-1000 J/KG ACROSS THE SUSQ VALLEY AND POINTS EAST. THIS
INSTABILITY INVOF THE AFOREMENTIONED SLOWING OCCLUDED FRONT WILL
COMBINE TO BRING THE BEST CHC FOR SHRA AND SOME LOW-TOPPED TSRA
NEAR...AND TO THE EAST OF A KIPT TO KSEG AND KMDT LINE.
ALTHOUGH LOCALIZED RAINFALL AMOUNTS AROUND 0.25 INCH ARE
POSSIBLE...BASIN AVERAGE AMOUNTS OVER THE NEXT 12 HOURS WILL BE
MAINLY UNDER 0.10 OF AN INCH.
THE WIND WILL GO WESTERLY IN THE WEST...AND VEER FROM S TO SW IN THE
LOWER SUSQ LATER LATE THIS AM. THIS LLVL DOWNSLOPE FLOW OFF THE
ALLEGHENY PLATEAU AND CENTRAL MTN WILL WARM AND DRY OUT THE BOUNDARY
LAYER A BIT. TEMPS SHOULD REACH A MID AFTERNOON MAX AROUND 80F FOR
THE SERN THIRD OF THE AREA...WHILE MOST OTHER LOCATIONS THROUGHOUT
THE CENTRAL RIDGE AND VALLEY REGION WILL MAKE IT TO THE M-U70S. THE
HIGHER TERRAIN OF THE NORTH AND WEST WILL SEE HIGH TEMPS IN THE
LOWER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
THE UPPER TROUGH TO OUR WEST DOES SWING EAST AND LIFT NORTH A BIT
TONIGHT AND WILL TRY TO SPIN UP A LITTLE WAVE ALONG THE OLD
FRONT...WHICH WILL BE DRAPED OVER FAR EASTERN PA AND DOWN INTO THE
CAROLINAS TONIGHT. ANY COHERENT SFC LOW WILL PASS JUST TO OUR
SE...BUT THE UPPER SUPPORT WILL FORCE SCT SHOWERS AS IT MOVES
PAST. TIMING IS A LITTLE UNCERTAIN...WITH THE WAVE JUST BEING
HANDLED IN THESE LAST FEW RUNS OF THE NCEP PROGS...BUT HAVE
BUMPED THE POPS UP TO MID-CHC LEVELS OVER THE SERN PART OF THE
FCST AREA TONIGHT AND KEPT THEM UP THAT HIGH FOR THE EAST DURING
THE FIRST HALF OF THURS. 8H TEMPS REMAIN HIGH...AND DEWPOINTS AS
WELL...SO MILD/WARM TEMPS CONTINUE TONIGHT AND THURSDAY. TEMPS
WILL MOST LIKELY RUN 10-12F HIGHER THAN NORMAL. SPOILED AS WE
HAVE BEEN...THE TEASER I LEAVE YOU WITH IS WHAT MAY COME TO PASS
LATE THIS WEEKEND. SEE BELOW FOR MORE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
GENERAL FLOW PATTERN
====================
THE 2 OCT 00 AND 12 UTC GLOBAL MODEL AND ENSEMBLE GUIDANCE
REMAINS IN AGREEMENT ON THE LARGE SCALE FLOW REGIME FCST ACROSS
NOAM. HIGH LATITUDE REX BLOCK IN THE NERN PAC WILL BE LESS
MIGRATORY THAN PREVIOUSLY FORECAST 24 HOURS AGO...WHICH SHOULD
ENSURE BROAD TROUGHING DOWNSTREAM OVER THE CENTRAL AND EASTERN
CONUS THROUGH THE PERIOD.
MODEL DIAGNOSTICS/PREFERENCES
=============================
CONCERNING THE MID-UPPER TROUGH WEAKENING/ACCELERATING NEWD OUT
OF THE MIDDLE MISSISSIPPI VALLEY ON D3...THE 12Z NAM IS ON THE
SLOWER/MORE AMPLIFIED SIDE OF MODEL SPREAD WITH LIFTING THE ENERGY
NORTHWARD THROUGH THE OHIO VALLEY INTO THE NORTHEAST THURSDAY.
OVERALL...THE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THIS
FEATURE.
THE LAST TWO RUNS OF THE ECMWF ARE STRONGER THAN THE NAM/GFS WITH
THE SHORTWAVE ROTATING THROUGH THE NRN PLAINS/UPPER MS VLY SAT-SUN.
THIS LEADS TO UNCERTAINTY REGARDING THE PCPN PATTERN EVOLVING EWD
THROUGH THE OH VLY INTO THE MID-ATLANTIC REGION...PARTICULARLY ON
DAY 6 (SUN). A COMPROMISE SOLUTION SUPPORTS HIGH END CHC TO LOW LKLY
POPS ON DAY 5. THE ECMWF IS MORE BULLISH THAN THE GFS FOR PCPN FOR
DAY 6...AS IT DEVELOPS AN AREA OF LOW PRES OVR THE MID-ATLC
PIEDMONT.
THE MODEL DIFFS WITH THE AFOREMENTIONED SHORTWAVE IMPACT THE TRACK
OF ASSOC SURFACE CYCLONE DEEPENING OVER THE UPPER MIDWEST/GREAT
LAKES THUR-FRI...AND EWD PROGRESSION OF STRONG TRAILING COLD FRONT
PUSHING EWD THROUGH THE MIDWEST/OH VLY. A ECMWF/UKMET BLEND IS
PREFERRED HERE AS A MIDDLE OF THE ROAD SOLUTION.
THE GFS LOOKS MORE PROGRESSIVE EARLY NEXT WEEK WITH SHORTWAVE
ENERGY ROTATING WITHIN THE MEAN TROUGH OVR THE GREAT LAKES REGION.
WEATHER IMPACTS
================
LATE-WEEK WARM SPELL FOLLOWED BY SIGNIFICANT COOL DOWN INTO
EARLY NEXT WEEK...
WEAKENING SYSTEM EJECTING NEWD FROM THE MS VLY WILL ACCELERATE NEWD
THRU THE NORTHEAST STATES ON THUR...FOLLOWED BY S/W RIDGING AND SFC
HI PRES THURS NGT INTO FRI. THURS AND FRIDAY LOOK MILD AND MAINLY
DRY. FRIDAY COULD BE THE WARMEST DAY AHEAD OF A STRONG COLD FRONT
PUSHING EWD THROUGH THE MIDWEST. FRONTAL SHOWERS MAY REACH THE NW
MTNS BY THE FRI AFTN...WITH MORE ORGANIZED RAINS LKLY FRI NGT
INTO SAT AS THE WELL-DEFINED COLD FRONT SHIFTS SEWD THROUGH
CENTRAL PA. PCPN MAY CONTINUE ON SUNDAY IF THE ECMWF SOLUTION
VERIFIES.
THE MAIN WEATHER IMPACT THIS PERIOD WILL BE A SHOT OF UNSEASONABLY
COLD AIR INVADING THE REGION OVER THE WEEKEND...WITH BELOW NORMAL
TEMPS CONTINUING THROUGH EARLY NEXT WEEK. THE EARLY SEASON COOL
DOWN IS WELL-ADVERTISED AND SUPPORTED BY BELOW NORMAL 500MB
HEIGHTS AND 850MB TEMPS IN THE ENSEMBLE MEANS. THIS MIGHT LEAD TO
THE FIRST LAKE EFFECT SNOW SHOWERS OF THE SEASON OVR THE WRN
MTNS...WHICH IS NOT UNUSUAL FOR EARLY OCTOBER.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AREAS OF LIFR CIGS AND VSBYS WILL PERSIST UNTIL AROUND 15Z.
AFTERWARD...CONDITIONS WILL CONTINUE TO GRADUALLY IMPROVE TO MVFR OR
VFR INTO THE EARLY AFTERNOON. A FEW...HIGH RESOLUTION REGION MODELS
HINTS AT A FEW WEAK WAVES OF LOW PRESSURE LIFTING NE
TODAY...BRINGING SCATTERED SHOWERS AND BRIEF REDUCTIONS IN CIGS AND
VSBYS INTO THE MVFR CATEGORY.
ALSO SOME MODELS LIKE THE NAM SHOW ANOTHER WAVE LIFTING NE ACROSS
THE EAST TONIGHT. FOG COULD BECOME A PROBLEM AGAIN TONIGHT...
ESPECIALLY IN AREAS THAT GET DECENT CLEARING.
ANOTHER BATCH OF SHOWERS POSSIBLE ACROSS THE NW THU AFT.
A NOTABLY STRONGER COLD FRONT MOVES GRADUALLY EAST ACROSS THE STATE
LATE FRIDAY INTO SATURDAY. SOME MODELS HAVE THIS FRONT STALLING FOR
THE FIRST PART OF THE WEEKEND.
OUTLOOK...
THU...AM LOW CIGS POSSIBLE EAST. AREAS OF FOG EARLY.
PERHAPS A SHOWER FAR EAST AND NW.
FRI...A FEW SHOWERS POSSIBLE...MAINLY NORTH.
SAT...AREAS OF RAIN AND FOG WILL BE POSSIBLE.
SUN...MAINLY VFR...BUT AN ISOLATED SHOWER POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...LAMBERT/MARTIN
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
330 PM EDT WED OCT 3 2012
.DISCUSSION...
CURRENTLY...
DIURNAL CONVECTION STRUGGLING TO GET STARTED OVER THE CWA THIS
AFTN...DUE IN PART TO SLIGHTLY DRIER AND MORE STABLE AIR ADVECTING
IN FROM THE S. LATEST RAP ANALYSIS SHOWS A MID LVL VORT MIN PARKED
BTWN LAKE OKEECHOBEE AND CAPE CANAVERAL EMBEDDED WITHIN DEEP SRLY
FLOW. MEANWHILE...A SLUG OF DRY LOW/MID LVL AIR IS NUDGING UP FROM S
FL UNDERNEATH AN UPR LVL AIRMASS THAT IS WEAKLY CONVERGENT...AXIS OF
THE H85-H70 THETA-E MINIMUM HAS WORKED ITS WAY UP FROM THE FL
STRAITS INTO THE LAKE OKEECHOBEE REGION. MOISTURE AND DYNAMIC LIFT
ACRS THE NRN CWA ARE MORE FAVORABLE FOR PRECIP...BUT CONTINUES UNDER
THE VEIL OF A MID/UPR LVL CLOUD DECK THAT IS HAMPERING SFC HEATING
AND LOW LVL DESTABILIZATION.
TONIGHT...
THE FCST QUANDARY...AREAS WHERE MOISTURE EXISTS ARE PLAGUED BY
DEBRIS CLOUDS...AND AREAS FREE OF DEBRIS CLOUDS HAVE DIMINISHING
MOISTURE. OVERALL MOISTURE AND INSTABILITY REMAINS TOO HIGH TO
COMPLETELY SUPPRESS DIURNAL PRECIP...BUT WILL NEED MESOSCALE BNDRY
INTERACTION AS A TRIGGER MECHANISM. THESE WILL BE IN THE FORM OF THE
EAST COAST SEA BREEZE AND OUTFLOW BNDRYS FROM THE CONVECTION OVER
THE WEST PENINSULA.
SHOULD SEE CONVECTION FIRE S OF THE I-4 CORRIDOR BY LATE AFTN.
HOWEVER...GIVEN THE DRIER AND MORE STABLE NATURE OF THE AIRMASS...
COVERAGE WILL BE SCT AT BEST. PRECIP ALONG AND N OF I-4 WILL
STRUGGLE AS PERSISTENT CONVECTION OVER THE WRN PENINSULA WILL
REINFORCE THE AFOREMENTIONED DEBRIS DECKS. HOWEVER...HIGH THETA-E
AIRMASS SHOULD ALLOW A LITTLE HIGHER COVERAGE...ALBEIT BLO 50PCT.
PRECIP WILL LINGER INTO THE MID EVNG HRS AND SHOULD BE SPENT BY
MIDNIGHT...LEAVING ONLY A SLGT CHC OF DEBRIS RAINFALL OVERNIGHT.
NO TURNOVER IN AIRMASS...MIN TEMPS WILL CONTINUE IN THE M70S.
THU-FRI...
LITTLE CHANGE IN THE WX PATTERN AS THE REMNANT MOISTURE PLUME FROM
THE ERSTWHILE FRONTAL TROF WILL REMAIN OVER THE FL PENINSULA...
KEEPING RAIN CHANCES ABV AVG ESPECIALLY OVER THE INTERIOR. AS THE
ATLC RIDGE AXIS BUILDS WEST INTO THE DEEP SOUTH...IT WILL MERGE WITH
A SMALL CONTINENTAL JUST S OF THE RIO GRANDE VALLEY. THE COMBINED
RIDGE WILL BRIDGE THE OLD FRNTL BNDRY AND GENERATE AN E/SE FLOW THRU
THE H100-H70 LYR. MOISTURE AVAILABILITY WILL REMAIN HIGH ENOUGH TO
SUPPORT POPS IN THE 40-50PCT RANGE BY DAY...30-40PCT AFT SUNSET
ENDING BY MIDNIGHT.
ONE CAVEAT TO THE NIGHTTIME PDS: AS WINDS BCM MORE SERLY...NOCTURNAL
COASTAL SHRAS/TSRAS WILL BECOME PSBL AS CONVERGENT EDDIES FORM ON
THE LEEWARD SIDE OF THE NRN BAHAMAS AND ADVECT TOWARD THE SPACE AND
TREASURE COASTS. MAX TEMPS IN THE U80S/L90S WITH MIN TEMPS IN THE
L/M70S.
SAT-WED...(PREV DISC)
00Z GFS AND ECMWF HAVE AGAIN PUSHED BACK THE PROGRESSION OF DRIER
AIR INTO THE REGION. HAVE KEPT 40 POP FOR SATURDAY BUT RAISED SUNDAY
TO 40 PERCENT NOW...TAPERING OFF MORE NOTICEABLY TO 20 TO 30 PERCENT
MONDAY AND TUE. BOTH MODELS EVENTUALLY SHUNT THE DEEP TROPICAL
MOISTURE AWAY FROM THE AREA AS UPPER TROUGHING OVER THE EASTERN
CONUS DRIVES A COLD FRONT THRU CENT FL EARLY NEXT WEEK. THERE
PROBABLY WILL NOT BE TOO MUCH COOLING BEHIND THIS FRONT AS THE FLOW
WILL TURN ONSHORE QUICKLY BEHIND IT...BUT THERE LOOKS TO BE
NOTICEABLE DRYING. THIS SHOULD HELP PRODUCE MIN TEMPS OVER INTERIOR
SECTIONS IN THE UPPER 60S FOR MON AND TUE MORNINGS.
&&
.AVIATION...
THRU 04/00Z...SCT/NMRS IFR SHRAS/ISOLD LIFR TSRAS ALL SITES WITH
HIGHEST POPS N OF THE I-4 CORRIDOR...SFC WNDSHFT FROM S TO E/SE AOB
12KTS BY 03/21Z INTERIOR SITES AND COASTAL SITES N OF KMLB. BTWN
04/00Z-04/03Z...SCT MVFR SHRAS/ISOLD IFR TSRAS. AFT 04/03Z...VFR
CONDS WILL PREVAIL WITH SLGT CHC OF BRIEF MVFR SHRAS.
&&
.MARINE...
TONIGHT...SFC/BNDRY LYR WINDS WILL BACK TO THE SE AS A LARGE RIDGE
AXIS EXTENDING FROM THE NRN BAHAMAS TO THE YUCATAN PENINSULA LIFTS N
ACRS THE CENTRAL PENINSULA. WINDS WILL DIMINISH TO BLO 10KTS N OF
THE CAPE...10-15KTS S OF THE CAPE. SEAS 2-3FT NEARSHORE AND 3-4FT
OFFSHORE. SCT SHRAS/TSRAS MOVING OFFSHORE N OF THE CAPE.
THU-SAT...
THE ATLC RIDGE WILL EXPAND WESTWARD INTO THE DEEP SOUTH AND MERGE
WITH A SMALLER RIDGE CENTERED JUST S OF THE RIO GRANDE VALLEY. THE
COMBINED RIDGE WILL FORCE SFC/BNDRY LYR WINDS TO BACK TO THE EAST
WHERE WHERE THEY WILL REMAIN INTO THE WEEKEND. SEAS 2-3 FT...MAINLY
IN AN ERLY SWELL. DOMINANT PDS INCREASING TO 11-13SEC AS THE E/NE
FETCH LENGTH EXPANDS THRU THE WEEK.
SAT-MON...
LIGHT AND VARIABLE WINDS SUN AS THE LCL PGRAD WEAKENS AHEAD OF THE
NEXT FRONTAL TROF. WINDS TO SHIFT TO THE N/NW BY DAYBREAK MON AS A
NEW FRONTAL TROF PUSHES INTO THE STATE...THEN TO THE N/NE THRU THE
DAY AS HIGH PRES BEHIND THE FRONT BUILDS QUICKLY ACRS THE GULF
COAST. SEAS AOB 2FT NEARSHORE...2-3FT OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 73 87 76 86 / 40 50 40 50
MCO 74 91 73 89 / 40 50 40 50
MLB 75 87 77 87 / 30 40 30 40
VRB 76 89 77 88 / 30 40 30 40
LEE 73 90 73 88 / 40 50 40 50
SFB 74 91 75 89 / 40 50 40 50
ORL 74 91 74 90 / 40 50 40 50
FPR 76 88 77 87 / 30 40 30 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX.....LASCODY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
251 PM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CIGS THROUGH THIS EVENING...IFR CIGS POSSIBLE THIS AFTERNOON.
* SHOWERS...POSSIBLY DRIZZLE THROUGH THIS EVENING.
* STRONG/GUSTY SOUTHWEST WINDS THURSDAY WITH A COLD FRONT LATE
THURSDAY AFTERNOON/EARLY THURSDAY EVENING. CMS
//DISCUSSION...UPDATED 18Z...
A WEAK AREA OF LOW PRESSURE CONTINUES TO SLOWLY MOVE NORTH ACROSS
NORTHEAST IL WITH QUITE VARIABLE CIGS...WHICH ARE LIFTING THROUGH
MVFR AND INTO VFR ACROSS CENTRAL IL AND FAIRLY CONFIDENT THIS
IMPROVING TREND WILL EVENTUALLY REACH THE TERMINALS THIS EVENING.
UNTIL THEN...IFR CIGS EXTEND AS CLOSE AS IKK TO GYY AND POINTS
EAST...WITH PATCHY IFR WITH HEAVIER SHOWERS. ITS STILL POSSIBLE
THAT IFR CIGS COULD AFFECT THE CHICAGO AREA TERMINALS THROUGH MID
AFTERNOON BUT APPEARS PREVAILING CIGS WILL REMAIN MVFR...OR
HIGHER AND HAVE TRENDED IN THIS DIRECTION. VISIBILITIES HAVE ALSO
SLOWLY IMPROVED TO MVFR OR BETTER...BUT IFR STILL POSSIBLE WITH
SHOWERS OR DRIZZLE.
WINDS HAVE ALREADY TURNED LIGHT SOUTHERLY ACROSS EASTERN IL AND
NORTHWEST INDIANA AND SHOULD REMAIN LIGHT SOUTH/SOUTHWEST THROUGH
THE NIGHT THEN BEGIN TO INCREASE IN SPEED AFTER SUNRISE THURSDAY.
SOME UNCERTAINTY REMAINS REGARDING HOW DEEP THE LOW LEVELS WILL
MIX ON THURSDAY. THE DEEPER THE MIXING...THE STRONGER THE WINDS
THAT WILL MIX TO THE SURFACE. FOR NOW HAVE TRENDED GUSTS INTO THE
MID/UPPER 20 KT RANGE BUT IF DEEPING MIXING DOES DEVELOP...GUSTS
INTO THE MID 30KT RANGE WILL BE POSSIBLE. A COLD FRONT WILL THEN
MOVE ACROSS THE AREA LATE IN THE AFTERNOON OR EARLY THURSDAY
EVENING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE REGARDING MVFR CIGS...LOW CONFIDENCE REGARDING
IFR CIGS.
* MEDIUM CONFIDENCE REGARDING SHOWERS AND END TIME.
* MEDIUM CONFIDENCE REGARDING WINDS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE SHOWERS AND SLIGHT CHANCE TS...OTHERWISE
VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ744-LMZ745...1 PM THURSDAY TO 10 PM
SATURDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...1 PM
THURSDAY TO 10 PM FRIDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...10 PM THURSDAY TO 4 AM SATURDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1212 PM CDT WED OCT 3 2012
.DISCUSSION...
ISSUED 1000 AM CDT WED OCT 3 2012
LATEST OBSERVATIONS AND SATELLITE IMAGERY SHOWING SURFACE LOW NOW
CENTERED JUST NORTH OF KANKAKEE. FAIRLY SHARP CLEARING LINE
PERSISTING ALONG THE ILLINOIS/IOWA BORDER...BUT IS NOT MAKING ANY
EASTWARD PROGRESS. ANOTHER CLEARING LINE CENTERED ROUGHLY ALONG
I-64 IN SOUTH CENTRAL ILLINOIS IS MOVING NORTHWARD INTO THE
SOUTHEAST EDGE OF OUR FORECAST AREA. LAYER HUMIDITY PLOTS OFF THE
RAP MODEL SHOW THIS SOUTHERN CLEARING AREA CONTINUING TO MAKE SOME
NORTHWARD PROGRESS THROUGH THE DAY...WITH SKIES BECOMING PARTLY
SUNNY SOUTH OF I-70 BY EARLY AFTERNOON. HOWEVER...THE REMAINDER OF
THE FORECAST AREA SHOULD REMAIN GENERALLY CLOUDY...WITH SOME THIN
SPOTS IN THE OVERCAST HERE AND THERE. RAP AND HRRR MODELS
CONTINUING TO HOLD ON TO SOME SCATTERED SHOWERS THROUGH THE
AFTERNOON.
HAVE SENT SOME UPDATED ZONES/GRIDS...MAINLY TO UPDATE HOURLY TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 1210 PM CDT WED OCT 3 2012
MVFR/IFR CONDITIONS RETREATING INTO NORTHEAST ILLINOIS AS LOW
PRESSURE LIFTS ACROSS THE CHICAGO AREA. STILL SOME CEILINGS AROUND
1500 FEET HANGING AROUND AS FAR SOUTH AS A KBMI-KCMI-KDNV LINE...
BUT THESE SHOULD MAINLY BE NORTH OF THE AREA BY 20Z. OTHERWISE...
VFR CEILINGS EXPECTED THROUGH THE AFTERNOON AND EARLY EVENING...
WITH SOME BREAKUP OF THE CLOUDS AS THE LOW PULLS FURTHER AWAY
FROM THE STATE. ON THURSDAY...SOUTHERLY WINDS WILL BEGIN TO PICK
UP LATE IN THE FORECAST PERIOD...WITH SOME GUSTS TO AROUND 15
KNOTS BY LATE MORNING. HOWEVER...HIGHER GUSTS ARE LIKELY DURING
THE AFTERNOON.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 240 AM CDT WED OCT 3 2012
SHORT TERM...TODAY THROUGH FRIDAY
PERSISTENT UPPER TROUGH WILL REMAIN IN PLACE FROM THE SOUTHERN
GREAT LAKES TO THE WESTERN GULF OF MEXICO TODAY...ENSURING A
CONTINUATION OF MOSTLY CLOUDY CONDITIONS. WITH WEAK SURFACE LOW
PRESSURE MEANDERING NORTHWARD ACROSS EAST-CENTRAL ILLINOIS...MAY
SEE A FEW SHOWERS SCATTERED AROUND THE AREA AS WELL. AS HAS BEEN
THE CASE FOR THE PAST COUPLE OF DAYS...THE DEEPEST MOISTURE AND
THUS BEST CHANCE FOR RAIN WILL BE CONFINED TO THE EASTERN KILX
CWA. AS A RESULT...WILL FOCUS HIGHEST POPS EAST OF I-55...TAPERING
DOWN TO JUST SLIGHT CHANCES FURTHER WEST IN THE ILLINOIS RIVER
VALLEY. TEMPERATURES WILL BE A BIT TRICKY TODAY...AS THEY WILL BE
HIGHLY DEPENDENT UPON HOW MUCH SUNSHINE OCCURS. 07Z/2AM SATELLITE
IMAGERY INDICATES THE ENTIRE AREA IS CURRENTLY BLANKETED BY CLOUD
COVER...AND WITH LOW PRESSURE SHIFTING ONLY VERY SLOWLY
NORTHWARD...THINK MOSTLY CLOUDY SKIES WILL PREVAIL THROUGHOUT THE
DAY. MAY SEE SOME BREAKS IN THE OVERCAST WEST OF THE ILLINOIS
RIVER FROM TIME TO TIME...AS WELL AS ALONG/SOUTH OF I-70 AS DRY
SLOT CONTINUES TO WRAP N/NW AROUND UPPER TROUGH. RESULTING HIGHS
WILL MAINLY BE IN THE LOWER 70S...WITH COOLEST READINGS IN THE
MIDDLE TO UPPER 60S ACROSS THE NE CWA AROUND CHAMPAIGN WHERE CLOUD
COVER WILL BE MOST PERSISTENT. UPPER TROUGH WILL FINALLY GET
EJECTED NORTHEASTWARD TONIGHT...IN RESPONSE TO NORTHERN STREAM
WAVE DIGGING INTO THE NORTHERN PLAINS/UPPER MIDWEST. WILL LINGER
LOW CHANCE POPS FOR SHOWERS INTO THE EVENING HOURS...BEFORE GOING
DRY ACROSS THE BOARD AFTER MIDNIGHT.
THURSDAY WILL BE THE WARMEST DAY OF THE FORECAST PERIOD...AS
STRONG SOUTHERLY FLOW AHEAD OF THE NEXT APPROACHING COLD FRONT
HELPS BOOST HIGH TEMPS INTO THE UPPER 70S AND LOWER 80S. COLD
FRONT IS STILL EXPECTED TO PUSH INTO ILLINOIS DURING THE
AFTERNOON...WITH MODEL CONSENSUS PLACING IT FROM JUST SOUTH OF
CHICAGO TO NEAR SAINT LOUIS BY EARLY EVENING. ALL MODELS CONTINUE
TO SUGGEST ANY PRECIP THAT DEVELOPS WILL BE PRIMARILY
POST-FRONTAL...MEANING MUCH OF CENTRAL ILLINOIS WILL REMAIN DRY
THROUGH THE ENTIRE DAY. WILL THEREFORE CONFINE POPS TO LOCATIONS
ALONG/WEST OF I-55 THURSDAY AFTERNOON...WITH DRY WEATHER
PERSISTING FURTHER EAST. RAIN CHANCES WILL INCREASE THURSDAY NIGHT
AS THE FRONT MOVES THROUGH THE REGION. GIVEN NARROW CORRIDOR OF
INSTABILITY AND INCREASING WIND-SHEAR ALONG/BEHIND THE
BOUNDARY...HAVE INCLUDED ISOLATED THUNDER THURSDAY AFTERNOON AND
EVENING.
FRONT WILL SINK INTO THE OHIO RIVER VALLEY ON FRIDAY...HOWEVER
UPPER-WAVE MOVING ALONG THE BOUNDARY WILL BRING A PERIOD OF
OVERRUNNING RAIN TO PARTS OF CENTRAL AND SOUTHEAST ILLINOIS
FRIDAY/FRIDAY NIGHT. HIGHEST RAIN CHANCES THROUGH THIS PERIOD WILL
BE ACROSS THE SOUTHERN CWA...GENERALLY ALONG/SOUTH OF I-70...WITH
RAIN CHANCES STEADILY DECREASING FURTHER NORTH. IN FACT...AREAS
ALONG AND NORTH OF A CANTON TO BLOOMINGTON-NORMAL LINE MAY REMAIN
COMPLETELY DRY ON FRIDAY. NORTHERLY WINDS BEHIND THE FRONT WILL
BRING SHARPLY COOLER CONDITIONS INTO THE REGION FOR THE END OF THE
WEEK...WITH HIGH TEMPS ON FRIDAY REMAINING IN THE 50S.
LONG TERM...SATURDAY THROUGH TUESDAY
ONCE UPPER WAVE TRACKS OFF TO THE EAST...FRONT WILL GET PUSHED
FURTHER SOUTH OVER THE WEEKEND...RESULTING IN COOL/DRY CONDITIONS
FOR BOTH SATURDAY AND SUNDAY. AS HIGH PRESSURE BUILDS INTO THE
REGION...CLEAR SKIES AND LIGHT WINDS WILL ALLOW OVERNIGHT LOW
TEMPS TO DROP INTO THE LOWER TO MIDDLE 30S BOTH DAYS. AFTER
THAT...SOUTHERLY RETURN FLOW ON THE BACK SIDE OF THE DEPARTING
HIGH WILL SIGNAL A WARMING TREND EARLY NEXT WEEK...WITH HIGH TEMPS
CLIMBING BACK INTO THE MIDDLE 60S BY TUESDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1109 AM CDT WED OCT 3 2012
.DISCUSSION...
255 AM CDT
THE FORECAST CONCERNS CENTER ON SHOWER AND DRIZZLE CHANCES TODAY
AND IMPACTS ON TEMPERATURES...FOLLOWED BY THE TEMPERATURE ROLLER
COASTER THURSDAY INTO FRIDAY WITH A STRONG AUTUMN COLD FRONT AND
ITS SHOWER CHANCES MOVING THROUGH THURSDAY AFTERNOON AND EVENING.
THE MORNING GOES WATER VAPOR LOOP DEPICTS THE ELONGATED AND FAIRLY
NARROW CLOSED LOW/UPPER TROUGH CENTERED FROM LOWER MICHIGAN TO THE
LOWER MISSISSIPPI VALLEY...NEARLY IDENTICAL PLACEMENT AS 24 HOURS
AGO. THE PRIMARY MID-LEVEL CIRCULATIONS NEAR ST LOUIS AND NORTHERN
LA WILL GENERALLY MERGE INTO ONE LOW OVER THE AREA BY EARLY
EVENING. A NARROW CORRIDOR OF DEEPER MOISTURE...WITH PWATS
SLIGHTLY OVER AN INCH AS INDICATED BY LAST EVES SOUNDINGS...EXISTS
WITHIN THE UPPER TROUGH AXIS. AT THE SURFACE...A 1012 MB LOW IS
REFLECTED ACROSS EAST CENTRAL IL WHICH WILL DRIFT NORTH TO CHICAGO
BY EARLY AFTERNOON. DEW POINTS IN THE MID 50S HAVE ALREADY SPREAD
UP AS FAR NORTH AS SOUTHEAST WI EARLY THIS MORNING AND WITH THIS
HAS DEVELOPED WIDESPREAD STRATUS AND SOME FOG AT THE CLOUD
PERIPHERY NEAR THE WI BORDER.
EARLY MORNING RADAR ECHOES AND OBSERVATIONS HAVE INDICATED
PRIMARILY DRIZZLE WITH A SPATTERING OF LIGHT SHOWERS AROUND THE
SURFACE LOW CENTER. RAP AND NAM ISENTROPIC ASCENT FORECASTS ARE
FOR CONTINUED VERY GRADUAL ASCENT AROUND THIS CIRCULATION
CENTER THROUGH THE MORNING...WITH ANY FOCUSED MOISTURE
CONVERGENCE NOT BEING STRONG. SO BELIEVE THE DRIZZLE MAY BE THE
PREDOMINANT FORM OF PRECIP THROUGH THE MORNING...WITH SPOTTY BRIEF
SHOWERS. BY AFTERNOON THROUGH MID-EVE SCATTERED SHOWERS LOOK TO BE
A LITTLE MORE FAVORED AS THE VORT MAX APPROACHES AND SLIGHTLY
BETTER MOISTURE TRANSPORT EVOLVES OVER THE AREA...ALONG WITH JUST
BETTER QG FORCING IN THE LEFT EXIT REGION OF THE JET MAX
PROGRESSING NORTH AROUND THE UPPER TROUGH. EXPLICIT MODEL RADAR
SIMULATIONS GENERALLY AGREE WITH THIS PORTRAYAL. CONTINUE WITH
40-50 PERCENT OF MEASURABLE POPS IN SHOWERS ACROSS MUCH OF THE
AREA EAST OF ILLINOIS 47...THOUGH THE CHANCES FOR ACTUALLY SEEING
SOME LIGHT PRECIP ARE PROBABLY MORE NEAR 70-80 PERCENT IN THESE
AREAS...IT JUST MAY NOT MEASURE. AREAS TOWARD INTERSTATE 39 ARE
LIKELY NOT TO SEE MUCH IF ANYTHING AT ALL DUE TO BEING WEST OF THE
BETTER FORCING AND DEEPER MOISTURE.
LOOKING UPSTREAM AT TEMPERATURES YESTERDAY ACROSS SOUTHERN IN AND
SOUTHEAST IL...READINGS WERE IN THE UPPER 50S TO LOWER 60S. WE
WILL HAVE A FAIRLY MILD STARTING POINT THANKS TO THE
STRATUS...WITH EARLY MORNING READINGS IN THE LOWER 60S IN MANY
AREAS FROM CHICAGO SOUTH. THE TEMPERATURE RANGE SHOULD BE
SMALL...SO HAVE HIGHS IN THE MID TO UPPER 60S ACROSS MOST OF THE
FORECAST AREA.
THE UPPER LOW HEADED FOR THE AREA SHOULD BE PICKED UP WELL BY
GUIDANCE NOW...AND AN IMPRESSIVE 12-HR 500 MB TEMPERATURE FALL OF
13C WAS OBSERVED WITH THIS FEATURE LAST EVE ON THE CYLW SOUNDING.
THIS WILL QUICKLY PROGRESS EAST THROUGH THURSDAY...DEEPENING A
SURFACE LOW ACROSS MN BY EARLY THURSDAY. THIS WILL ALLOW WARM AIR
ADVECTION TO INCREASE ACROSS THE AREA. WHILE SOME LINGERING CLOUDS
ARE POSSIBLE THURSDAY MORNING IN EASTERN AREAS...ANY SHOULD
QUICKLY MOVE OUT WITH THE WARM AIR ADVECTION PUSH. SO STILL
EXPECTING A WARM-UP INTO THE MID TO UPPER 70S ACROSS A GOOD PART
OF THE AREA. BY THURSDAY AFTERNOON AND EVENING...MODEST HEIGHT
FALLS AND FORCING ARE EXPECTED TO GRADUALLY BECOME MORE IN TANDEM
WITH THE LOW-LEVEL BAROCLINIC ZONE AND CONVERGENCE OF THE FRONT.
THE DEEP MOISTURE STILL APPEARS FAIRLY NARROW...ESPECIALLY IN THE
PRE-FRONTAL AIR MASS. SO TOUGH TO GO LIKELY FOR SHOWERS...BUT DO
THINK AT LEAST SCATTERED WILL BE SEEN WITH THE FRONT BY MID-
AFTERNOON THROUGH MID-EVE THURSDAY AS IT PROGRESSES THROUGH.
DYNAMICS ALONG WITH A NARROW CORRIDOR OF 500 J/KG OF MUCAPE
ADVERTISED BY THE 03.00 AND 03.06 NAM SUPPORT A SLIGHT CHANCE FOR
THUNDER. TEMPERATURES WILL FALL QUICKLY BEHIND THE FRONT. WINDS
LOOK TO BE BREEZY WITH NEAR 35 MPH GUSTS ON THE WARM AIR ADVECTION
SIDE OF THE FRONT. WHILE THEY LOOK TO NOT BE TOO STRONG IN THE
IMMEDIATE COLD AIR ADVECTION PUSH...THEY SHOULD PICK UP ON FRIDAY
AS THE ATMOSPHERIC WINDS BECOME MORE UNIDIRECTIONAL.
FRIDAY THROUGH SUNDAY WILL SEE HIGHS WELL BELOW NORMAL AS 850 MB
TEMPERATURES FALL TO 0C BY LATER FRIDAY AND STAY BELOW THROUGH THE
WEEKEND. LOOKING AT LOCAL CLIMATOLOGY FOR EARLY OCTOBER AND SUCH
850 MB TEMPERATURES...THE MEDIAN HIGH AT ORD IS 53 AND LOW IS 32
AND THIS REGIME SHOULD ALLOW FOR THIS CONDITIONAL CLIMATOLOGY TO
PAN OUT. A FEW LOCATIONS ON SATURDAY MAY NOT REACH 50. AS THE
ENTIRE UPPER TROUGH ACROSS CENTRAL NORTH AMERICA TAKES SHAPE
FRIDAY INTO SATURDAY...THE NORTHERN STREAM JET WILL PASS ATOP THE
AREA WITH MULTIPLE SHORT WAVES RIDING THE BAROCLINIC ZONE JUST TO
THE SOUTH. CONFIDENCE FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON ON SHOWERS IS PRETTY LOW RIGHT NOW...BUT IT WOULD
CERTAINLY SEEM THE MOST FAVORED AREA FOR FAIRLY COLD RAIN SHOWERS
WOULD BE ACROSS THE SOUTHERN FORECAST AREA IF THINGS WERE ABLE TO
LINE UP. ANY LAKE EFFECT SHOWERS LOOK TO PRIMARILY BE DIRECTED
TOWARDS THE EASTERN PART OF THE LAKE...THOUGH NORTHWEST INDIANA
MAY BE CLIPPED SATURDAY AND SUNDAY. SUNDAY MAY NEED TO HAVE A
SLIGHT CHANCE ADDED FOR A LARGER PART OF THE AREA AS THE UPPER
TROUGH PASSES ACROSS THE REGION.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* VARIABLE WINDS BECOMING SOUTHERLY LATER THIS AFTERNOON.
* MVFR CIGS INTO TONIGHT...WITH IFR CIGS POSSIBLE THROUGH MID
AFTERNOON.
* SHOWERS/AREAS OF DRIZZLE TODAY...POSSIBLY REDUCING VIS TO IFR
THROUGH MID AFTERNOON. CMS
//DISCUSSION...UPDATED 12Z...
CONDITIONS HAVE QUICKLY DETERIORATED THIS MORNING WITH THE ARRIVAL
OF THIS WEAK LOW PRESSURE AND EXPANSIVE AREA OF LOW LEVEL
MOISTURE. IFR CEILINGS BEING REPORTED ACROSS ORD/MDW/GYY
AREAS...WITH THESE LOW CLOUDS TO AFFECT DPA IN THE NEXT HOUR AND
RFD TO REMAIN VFR THROUGH THE FORECAST PERIOD. HAVE CONTINUED
PESSIMISTIC TRENDS WITH LOW CEILINGS TODAY...KEEPING IFR
CONDITIONS OVERHEAD FOR MUCH OF THE DAY. SOME UNCERTAINTY AS TO
THE OVERALL TREND WITH THE CEILINGS TODAY REMAINS...AS IT IS
CONCEIVABLE THAT THESE IFR CONDITIONS COULD LINGER EVEN INTO THE
EARLY EVENING BEFORE LOW/MID LEVEL FLOW INCREASES AND REALLY HELPS
STEER THIS MOISTURE OUT OF THE TERMINAL AREAS. ALTHOUGH AT THIS
TIME...HAVE NOT GONE THAT FAR WITH THE FORECAST AND BRING CEILINGS
UP TO MVFR CONDITIONS LATER THIS AFTERNOON AND THEN EVENTUALLY
SCATTERING THEM OUT TONIGHT. FOG/DRIZZLE WILL ALSO CONTINUE FOR A
GOOD PORTION OF TODAY...WITH VIS RESTRICTIONS EXPECTED INTO THIS
AFTERNOON. WITH THE WEAKENING LOW CENTER MOVING
OVERHEAD...VARIABLE WINDS WILL BE OBSERVED FOR MOST OF TODAY
BEFORE SURFACE PATTERN ALLOWS FOR WINDS TO BECOME MORE ORGANIZED
OUT OF THE SOUTH. VFR CONDITIONS EXPECTED THURSDAY MORNING BUT
WITH SOUTH/SOUTHWEST WINDS/GUSTS REALLY INCREASING BY MID DAY.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
* MEDIUM CONFIDENCE REGARDING MVFR CIGS...LOW CONFIDENCE REGARDING
IFR CIGS.
* MEDIUM CONFIDENCE REGARDING SHOWERS AND VIS TRENDS. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...CHANCE SHOWERS AND SLIGHT CHANCE TS...OTHERWISE
VFR.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
TUESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
543 AM CDT
THE WINDS HAVE DIMINISHED OVERNIGHT WITH WAVES ALSO SUBSIDING AS
THE PRESSURE GRADIENT OVER THE LAKE REMAINS SOMEWHAT RELAXED THIS
MORNING. ALTHOUGH LOW PRESSURE WILL BE APPROACHING THE LAKE
TODAY...IT IS FAIRLY WEAK AND WILL CONTINUE A WEAKENING TREND.
AFTER SOME LIGHTER WINDS ACROSS THE LAKE TODAY...WINDS WILL BE ON
THE INCREASE TONIGHT INTO THURSDAY AS LOW PRESSURE OVER THE
NORTHERN PLAINS DRAWS NEAR. THIS LOW WILL SLOWLY CONTINUE MOVING
NORTHEAST THROUGH ONTARIO ON THURSDAY WITH SOUTHWEST WINDS
EXPECTED OVER THE ENTIRE LAKE WITH SPEEDS EXPECTED TO STAY IN THE
15 TO 25KT RANGE FOR THE OPEN WATERS AS WARMER AIR OVER THE COOLER
LAKE WILL HELP KEEPS WINDS DOWN. THE NEARSHORE WATERS ON THURSDAY
COULD EXPERIENCE SOME STRONG SOUTHWEST WINDS TO 30 KT...WITH EVEN
AN OUTSIDE POSSIBILITY OF STRONGER WINDS FOR SOME TIME THURSDAY
AFTERNOON. THIS LOW WILL THEN DRAG A COLD FRONT ACROSS THE LAKE
THURSDAY NIGHT WITH WINDS THEN EXPECTED TO REALLY INCREASE
THURSDAY NIGHT INTO FRIDAY MORNING. A CONTINUED TREND TOWARDS
STRONGER WINDS OVER THE NORTHERN END OF THE LAKE APPEARS TO BE
CONTINUING WITH A PERIOD OF GALES POSSIBLE FROM THURSDAY EVENING
INTO THE MIDDLE PART OF THE DAY ON FRIDAY. WINDS WILL BE SLOW TO
DIMINISH FRIDAY AS THIS LOW PRESSURE SYSTEM WILL BE SLOWLY
SHIFTING TO THE EAST...AND STRONG HIGH PRESSURE BUILDS IN ON THE
BACKSIDE OF THIS SYSTEM.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1223 PM MDT WED OCT 3 2012
.UPDATE...
ISSUED AT 547 AM MDT WED OCT 3 2012
ISSUED RED FLAG WARNING FOR SOUTHWEST NEBRASKA COUNTIES AND YUMA
COUNTY COLORADO. SEE FIRE SECTION FOR DETAILS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 247 AM MDT WED OCT 3 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS A SHORTWAVE RIDGE
EXTENDING NORTH ACROSS NORTHWEST KANSAS AND CENTRAL NEBRASKA.
UPSTREAM A TROUGH IS DIGGING SOUTH INTO NORTHERN IDAHO AND
WESTERN MONTANA. AT THE SURFACE...LOW PRESSURE REMAINS IN PLACE
ACROSS THE HIGH PLAINS WITH A SURFACE COLD FRONT DEEPENING ACROSS
SOUTH DAKOTA...AND A SURFACE TROUGH AXIS EXTENDING JUST WEST OF
THE COLORADO/KANSAS STATE LINE.
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS IN THE UPPER
80S/LOW 90S AS SOUTHERLY FLOW ADVECTS MUCH WARMER AIR INTO THE
REGION AHEAD OF THE APPROACHING COLD FRONT.
TONIGHT...THE COLD FRONT OVER SOUTH DAKOTA IS EXPECTED TO PUSH
SOUTH ACROSS THE CWA BY MIDNIGHT AS THE SHORTWAVE TROUGH DIGS
SOUTH AND EAST ACROSS THE NORTHERN PLAINS. WINDY CONDITIONS ARE
EXPECTED THIS EVENING AND OVERNIGHT BEHIND THE FRONT...AND WILL
APPROACH WIND ADVISORY CRITERIA WITH GUSTS POSSIBLY IN THE 40-45
MPH RANGE. I WAS NOT CONFIDENT ENOUGH TO GO THAT HIGH YET WITH
SOME DIFFERENCES BETWEEN GUIDANCE ON MAGNITUDE OF THE WINDS...AND
THE WINDOW FOR THESE CONDITIONS SEEMS TO BE FAIRLY BRIEF. A FEW
SHOWERS WILL BE POSSIBLE MAINLY IN THE 03Z- 09Z TIME FRAME WHEN
BEST LARGE SCALE ASCENT IS ADVERTISED. DUE TO THE SPEED AND
NORTHERN TRACK OF THE TROUGH AND MINIMAL MOISTURE...CONFIDENCE IS
LOW IN MEASURABLE PRECIP. I KEPT POPS LIMITED TO SLIGHT CHANCE
CATEGORY FOR NOW...AND CONSIDERED ONLY INCLUDING MENTION OF
SPRINKLES.
THURSDAY...COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN THE
50S/60S AND OVERNIGHT LOWS THURSDAY NIGHT IN THE MID 30S. WIND AND
INCREASING CLOUDS WILL LIMIT RADIATION COOLING THURSDAY
NIGHT...OTHERWISE I WOULD BE CONCERNED WITH HARD FREEZE CONDITIONS
BASED ON ADVERTISED H85 TEMPS IN THE 0C-3C RANGE. FOR NOW IT
LOOKS LIKE WE WILL BE IN THE UPPER LIMIT OF LOCAL FROST ADVISORY
CRITERIA.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 247 AM MDT WED OCT 3 2012
THE ANTICIPATED SIGNIFICANT WEATHER CHANGE STILL LOOKS ON TRACK
FOR THE WEEKEND AS A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH IS
FORECAST TO SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND
SATURDAY. DYNAMICS FROM A 105 KT JET AT 250 MB WILL ENHANCE LIFT
FRIDAY NIGHT INTO SATURDAY MORNING WHEN BOTH THE GFS/EC FORECAST A
SATURATED LOWER ATMOSPHERE. GIVEN 850 MB TEMPS OF ZERO TO -2C AND
SATURATED AIR ABOVE -10C...ANTICIPATE LIGHT SNOW ACROSS THE
COLORADO COUNTIES SATURDAY MORNING AND A RAIN-SNOW MIX POSSIBLE
FURTHER EAST. GUIDANCE SUGGESTS LOW AND MID LEVELS WILL RAPIDLY
DRY OUT SATURDAY AFTERNOON AS THE JET AXIS AND UPPER TROUGH SLIDE
SOUTHEAST OF THE FORECAST AREA...ENDING PRECIP CHANCES.
850 MB TEMPERATURES OF 0 TO -2C ARE FORECAST SATURDAY MORNING...
WARMING ONLY A FEW DEGREES BY LATE AFTERNOON. HIGHS WILL HOLD IN THE
40S WHICH IS 25-30 DEGREES BELOW NORMAL. THE NORTHWEST THIRD OF THE
AREA SHOULD SEE MIN TEMPS SATURDAY IN THE 30-32 F RANGE AND BY
SUNDAY MORNING WITH LESS CLOUDS...MIN TEMPERATURES COULD DROP AS LOW
AS THE UPPER 20S...MAINLY IN THE NORTHWEST...WITH LOW 30S ELSEWHERE.
AFTERNOON HIGH TEMPERATURES WILL MODERATE SUNDAY AND MONDAY WITH
TEMPS STILL BELOW NORMAL BUT RETURNING TO THE 50S SUNDAY AND 60S
MONDAY. BOTH GFS/EC HINT AT ANOTHER COLD FRONT ARRIVING TUESDAY
WITH THE AIR MASS MOVING THROUGH RATHER QUICKLY...AND THE
POTENTIAL FOR PRECIPITATION AROUND MID WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1155 AM MDT WED OCT 3 2012
SOUTHWESTERLY WINDS WILL GRADUALLY PICK UP THROUGH THE AFTERNOON
AS A STRONG COLD FRONT DROPS SOUTH AND MOVES ACROSS THE REGION. EXPECTED
ARRIVAL TIME OF COLD FRONT IS BETWEEN 00-02Z THIS EVENING...WITH
NORTHERLY WINDS GUSTING 30-35 KTS BEHIND THE FRONT. STRONGEST
WINDS APPEAR TO BE RIGHT AFTER THE FRONT PASSES AND WILL GRADUALLY
WEAKEN THROUGH THE END OF THE PERIOD. THE OTHER CONCERN IS FOCUSED
ON PRECIPITATION CHANCES BEHIND THE FRONT. GIVEN CURRENT UPSTREAM
OBSERVATIONS AND MODEL ANALYSIS...LIGHT RAIN IS EXPECTED TO DEVELOP FOR A
FEW HOURS AND MAY REDUCE VISIBILITY BRIEFLY. CONDITIONS WILL
IMPROVE BY MID MORNING AS THE FRONT CONTINUES TO PUSH SOUTH.
&&
.FIRE WEATHER...
ISSUED AT 547 AM MDT WED OCT 3 2012
RH VALUES LOOK TO DROP TO WITHIN RED FLAG CRITERIA OVER MOST OF
THE AREA HOWEVER WINDS WILL REMAIN MARGINAL. THE BEST CHANCE FOR
RED FLAG CONDITIONS OVER THE NORTHWEST LATE THIS AFTERNOON. 06Z
NAM/GFS SHOW SUSTAINED WINDS THIS AFTERNOON IN THE 10 TO 20 MPH
ACROSS THE NORTH WITH GOOD MIXING EXPECTED GUSTS IN THE NORTH
SHOULD REACH 25 MPH. AS THE COLD FRONT DROPS SOUTH INTO THE
NORTHERN FRINGE OF OUR CWA WINDS SHOULD SHIFT TO THE NORTH AND
FURTHER INCREASE WITH GUSTS 30 TO 40 MPH. CONSIDERING THE TIMING
OF THE FRONT AND MODEL TRENDS I DECIDED TO ISSUE A RED FLAG
WARNING FOR OUR SOUTHWEST NEBRASKA COUNTIES AND YUMA COUNTY
COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ252.
NE...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR
NEZ079>081.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...DLF
AVIATION...PMM
FIRE WEATHER...DR
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1227 PM CDT WED OCT 3 2012
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 408 AM CDT WED OCT 3 2012
A COMPACT BUT STRONG STORM SYSTEM CONTINUED TO DEVELOP EARLY THIS
MORNING OVER WESTERN MONTANA. RAP ANALYSIS SHOWED A 90-KT JET
STREAK AT 400MB ROUNDING THE BASE OF THE DEVELOPING TROUGH AXIS.
ADDITIONAL JET STREAK ENERGY CONTINUED TO DIG SOUTHWARD TOWARD THE
BASE OF THE TROUGH. THE MID LEVEL COLD FRONT WAS MOVING TOWARD
YELLOWSTONE NATIONAL PARK AS OF 08Z. NEAR THE CENTER OF THIS
STORM...SNOW OBSERVATIONS WERE FOUND AT GREAT FALLS AND CUT BANK,
MONTANA WHERE TEMPERATURES CONTINUED TO FALL INTO THE LOWER 30S.
AHEAD OF THIS STORM SYSTEM...SKY WAS CLEAR ACROSS PRETTY MUCH THE
ENTIRE GREAT PLAINS. SURFACE LEE TROUGH EXTENDED FROM A WEAK LOW
CENTER (1003MB) JUST EAST OF CHADRON, NE SOUTH-SOUTHWESTWARD INTO
EASTERN COLORADO.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 408 AM CDT WED OCT 3 2012
THE STRONG COLD FRONT PUSHING SOUTH TODAY WILL REACH THE SOUTHERN
NEBRASKA PANHANDLE BY LATE AFTERNOON. A DOWNSLOPE WARM THERMAL
RIDGE WILL NOSE NORTHEAST THROUGH NORTHWEST KANSAS INTO CENTRAL
NEBRASKA...WHICH IS WHERE WARMEST SURFACE TEMPERATURES SHOULD BE
TODAY (WITH SCATTERED HIGHS IN THE 91 TO 93F RANGE)...MAINLY NORTH
OF THE DDC FORECAST AREA. ACROSS SOUTHWEST KANSAS...UPPER 80S SHOULD
BE COMMON FOR HIGHS WHICH WAS WHAT THE PREVIOUS FORECAST HAD...SO NO
CHANGE OF SIGNIFICANCE WAS MADE. SURFACE WINDS LATE AFTERNOON
SHOULD REACH 15 TO 18 KNOTS EAST OF A WAKEENEY TO LIBERAL LINE WHERE
LOW LEVEL PRESSURE GRADIENT WILL RESIDE. TIMING OF THE FRONT IS
COMING INTO BETTER FOCUS...AND WILL LEAN ON THE NAM12 FOR TIMING.
AT 06Z...FRONT SHOULD BE KNOCKING ON THE DOOR STEP OF THE DDC
FORECAST AREA (SYRACUSE TO WAKEENEY LINE). THE SUBSTANTIAL PRESSURE
RISES BEHIND THE FRONT COMBINED WITH THE GRADIENT ITSELF SHOULD
RESULT IN SURFACE WINDS OF 25 TO 28 KNOTS SUSTAINED FOR PROBABLY A
THREE-HOUR PERIOD. THIS WILL LIKELY WARRANT ISSUANCE OF A WIND
ADVISORY...BUT WILL HOLD OFF ON ISSUANCE OF ONE THIS FORECAST
CYCLE. WILL GO AHEAD AND KEEP THE 20 POPS IN FOR AREAS MAINLY NORTH
OF HIGHWAY 96 FOR LIGHT RAIN SHOWERS GIVEN SUCH STRONG LOW LEVEL
FRONTOGENESIS IN THE 06-12Z TIME FRAME TONIGHT. SREF MEANS AND
ECMWF MODEL DOES SHOW A SLIGHT QPF SIGNAL...BUT ABSENCE OF QUALITY
LOW LEVEL MOISTURE WILL BE AN ISSUE TO GENERATE ANYTHING MORE THAN
JUST A FEW HUNDREDTHS OF AN INCH OF PRECIPITATION SHOULD ANY RAIN
SHOWERS FORM AT ALL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 249 AM CDT WED OCT 3 2012
MEDIUM RANGE MODELS INDICATE A STRONG UPPER LEVEL TROUGH OF LOW
PRESSURE SWINGING EASTWARD OUT OF THE NORTHERN PLAINS INTO THE
WESTERN GREAT LAKES REGION THURSDAY. THIS SYSTEM WILL BRING THE
POSSIBILITY FOR PRECIP TO THE DAKOTAS, NEBRASKA, AND INTO THE UPPER
MIDWEST THURSDAY. ALTHOUGH AN ATTENDANT COLD FRONT IS PROJECTED TO
PUSH SOUTHEAST INTO AND ACROSS WESTERN KANSAS EARLY THURSDAY, LITTLE
IF ANY PRECIP WILL BE POSSIBLE ACROSS SOUTHWEST AND CENTRAL KANSAS
DUE TO THE LACK OF LOW/MID LEVEL MOISTURE AND INSTABILITY. HOWEVER,
A STRONG JET IS EXPECTED TO TRANSITION OUT OF THE NORTHERN AND
CENTRAL ROCKIES INTO THE WESTERN HIGH PLAINS THURSDAY PROVIDING
STRONG UPPER LEVEL DYNAMICS. SO, CANNOT RULE OUT AN OUTSIDE SLIGHT
CHANCE FOR LIGHT PRECIP AS FAR SOUTH AS CENTRAL KANSAS TO INCLUDE
THE I-70 CORRIDOR. OTHERWISE, GENERALLY DRY CONDITIONS ARE EXPECTED
ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS THROUGH FRIDAY AFTERNOON.
THERE IS A CHANCE FOR PRECIP FRIDAY NIGHT INTO EARLY SATURDAY AS A
SECONDARY UPPER LEVEL JET CORE EJECTS OUT OF THE ROCKIES INTO THE
WESTERN HIGH PLAINS. THIS WILL COINCIDE WITH A COOLING OF THE
ATMOSPHERE AT ALL LEVELS BRINGING GFS AND ECMWF SOUNDING PROFILES
TO NEAR SATURATION FRIDAY NIGHT INTO EARLY SATURDAY.
TEMPERATURES WILL BE WELL BELOW NORMAL THURSDAY IN WAKE OF A STRONG
COLD FRONT PUSHING SOUTHEAST ACROSS WESTERN KANSAS WEDNESDAY NIGHT.
STRONG COLD AIR ADVECTION SOUTHWARD INTO WESTERN KANSAS WILL LOWER
H85 TEMPERATURES DOWN INTO THE SINGLE DIGITS(C) ACROSS THE AREA
WITH NEAR 10C IN FAR SOUTHWESTERN KANSAS. TEMPERATURES ARE LIKELY
TO STRUGGLE TO REACH THE 60S(F) WITH MID TO UPPER 50S(F) POSSIBLE
FURTHER NORTH NEAR THE I-70 CORRIDOR. SIMILAR HIGH TEMPERATURES
ARE EXPECTED FRIDAY BEFORE ANOTHER SURGE OF COLDER AIR DROPS SOUTH
INTO WESTERN KANSAS EARLY IN THE WEEKEND. THIS WILL KEEP
TEMPERATURES DOWN BELOW NORMAL THROUGH VERY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1213 PM CDT WED OCT 3 2012
A STRONG UPPER LEVEL SHORTWAVE TROUGH WILL DIG INTO THE NORTHERN
PLAINS TODAY AND INTO THE UPPER MIDWEST TONIGHT. THIS SYSTEM WILL
DRIVE A STRONG COLD FRONT ACROSS WESTERN KANSAS OVERNIGHT. THE
COLD FRONT WILL SWITCH WINDS FROM THE SOUTH TO ABRUPTLY NORTH AT
25-35KT AT KHYS AROUND 04Z, KGCK AROUND 05Z, AND KDDC AROUND 06Z.
AHEAD OF THE FRONT SOUTH WINDS THIS AFTERNOON AROUND 15-25KT WILL
DECREASE TO SOUTH AROUND 10-15KT THIS EVENING. A POST FRONTAL STRATUS
DECK ALSO MAY FORM WITH CIGS BKN050-070BKN-OVC. AN ISOLATED ELEVATED
THUNDERSTORM IS ALSO POSSIBLE BEHIND THE COLD FRONT UNDERNEATH A
COLD POOL ALOFT WITH SOME MID LEVEL MOISTURE.
&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 46 62 42 / 0 10 0 10
GCK 87 45 62 42 / 0 10 0 10
EHA 88 45 61 42 / 0 10 0 0
LBL 88 47 62 43 / 0 10 0 0
HYS 87 45 61 40 / 0 20 10 10
P28 86 52 64 46 / 0 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
548 AM MDT WED OCT 3 2012
.UPDATE...
ISSUED AT 547 AM MDT WED OCT 3 2012
ISSUED RED FLAG WARNING FOR SOUTHWEST NEBRASKA COUNTIES AND YUMA
COUNTY COLORADO. SEE FIRE SECTION FOR DETAILS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 247 AM MDT WED OCT 3 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS A SHORTWAVE RIDGE
EXTENDING NORTH ACROSS NORTHWEST KANSAS AND CENTRAL NEBRASKA.
UPSTREAM A TROUGH IS DIGGING SOUTH INTO NORTHERN IDAHO AND
WESTERN MONTANA. AT THE SURFACE...LOW PRESSURE REMAINS IN PLACE
ACROSS THE HIGH PLAINS WITH A SURFACE COLD FRONT DEEPENING ACROSS
SOUTH DAKOTA...AND A SURFACE TROUGH AXIS EXTENDING JUST WEST OF
THE COLORADO/KANSAS STATE LINE.
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS IN THE UPPER
80S/LOW 90S AS SOUTHERLY FLOW ADVECTS MUCH WARMER AIR INTO THE
REGION AHEAD OF THE APPROACHING COLD FRONT.
TONIGHT...THE COLD FRONT OVER SOUTH DAKOTA IS EXPECTED TO PUSH
SOUTH ACROSS THE CWA BY MIDNIGHT AS THE SHORTWAVE TROUGH DIGS
SOUTH AND EAST ACROSS THE NORTHERN PLAINS. WINDY CONDITIONS ARE
EXPECTED THIS EVENING AND OVERNIGHT BEHIND THE FRONT...AND WILL
APPROACH WIND ADVISORY CRITERIA WITH GUSTS POSSIBLY IN THE 40-45
MPH RANGE. I WAS NOT CONFIDENT ENOUGH TO GO THAT HIGH YET WITH
SOME DIFFERENCES BETWEEN GUIDANCE ON MAGNITUDE OF THE WINDS...AND
THE WINDOW FOR THESE CONDITIONS SEEMS TO BE FAIRLY BRIEF. A FEW
SHOWERS WILL BE POSSIBLE MAINLY IN THE 03Z- 09Z TIME FRAME WHEN
BEST LARGE SCALE ASCENT IS ADVERTISED. DUE TO THE SPEED AND
NORTHERN TRACK OF THE TROUGH AND MINIMAL MOISTURE...CONFIDENCE IS
LOW IN MEASURABLE PRECIP. I KEPT POPS LIMITED TO SLIGHT CHANCE
CATEGORY FOR NOW...AND CONSIDERED ONLY INCLUDING MENTION OF
SPRINKLES.
THURSDAY...COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN THE
50S/60S AND OVERNIGHT LOWS THURSDAY NIGHT IN THE MID 30S. WIND AND
INCREASING CLOUDS WILL LIMIT RADIATION COOLING THURSDAY
NIGHT...OTHERWISE I WOULD BE CONCERNED WITH HARD FREEZE CONDITIONS
BASED ON ADVERTISED H85 TEMPS IN THE 0C-3C RANGE. FOR NOW IT
LOOKS LIKE WE WILL BE IN THE UPPER LIMIT OF LOCAL FROST ADVISORY
CRITERIA.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 247 AM MDT WED OCT 3 2012
THE ANTICIPATED SIGNIFICANT WEATHER CHANGE STILL LOOKS ON TRACK
FOR THE WEEKEND AS A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH IS
FORECAST TO SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND
SATURDAY. DYNAMICS FROM A 105 KT JET AT 250 MB WILL ENHANCE LIFT
FRIDAY NIGHT INTO SATURDAY MORNING WHEN BOTH THE GFS/EC FORECAST A
SATURATED LOWER ATMOSPHERE. GIVEN 850 MB TEMPS OF ZERO TO -2C AND
SATURATED AIR ABOVE -10C...ANTICIPATE LIGHT SNOW ACROSS THE
COLORADO COUNTIES SATURDAY MORNING AND A RAIN-SNOW MIX POSSIBLE
FURTHER EAST. GUIDANCE SUGGESTS LOW AND MID LEVELS WILL RAPIDLY
DRY OUT SATURDAY AFTERNOON AS THE JET AXIS AND UPPER TROUGH SLIDE
SOUTHEAST OF THE FORECAST AREA...ENDING PRECIP CHANCES.
850 MB TEMPERATURES OF 0 TO -2C ARE FORECAST SATURDAY MORNING...
WARMING ONLY A FEW DEGREES BY LATE AFTERNOON. HIGHS WILL HOLD IN THE
40S WHICH IS 25-30 DEGREES BELOW NORMAL. THE NORTHWEST THIRD OF THE
AREA SHOULD SEE MIN TEMPS SATURDAY IN THE 30-32 F RANGE AND BY
SUNDAY MORNING WITH LESS CLOUDS...MIN TEMPERATURES COULD DROP AS LOW
AS THE UPPER 20S...MAINLY IN THE NORTHWEST...WITH LOW 30S ELSEWHERE.
AFTERNOON HIGH TEMPERATURES WILL MODERATE SUNDAY AND MONDAY WITH
TEMPS STILL BELOW NORMAL BUT RETURNING TO THE 50S SUNDAY AND 60S
MONDAY. BOTH GFS/EC HINT AT ANOTHER COLD FRONT ARRIVING TUESDAY
WITH THE AIR MASS MOVING THROUGH RATHER QUICKLY...AND THE
POTENTIAL FOR PRECIPITATION AROUND MID WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 510 AM MDT WED OCT 3 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. SOUTHERLY WINDS AROUND 10KTS WILL SHIFT TO THE NORTH
AFTER SUNSET AND INCREASE AS A COLD FRONT MOVES THROUGH THE
REGION THIS EVENING. GUSTS AROUND 30KTS WILL BE POSSIBLE AT BOTH
TERMINALS. A FEW SHOWERS WILL BE POSSIBLE...HOWEVER COVERAGE LOOKS
TO BE LIMITED SO WILL NOT MENTION IN TAFS.
&&
.FIRE WEATHER...
ISSUED AT 547 AM MDT WED OCT 3 2012
RH VALUES LOOK TO DROP TO WITHIN RED FLAG CRITERIA OVER MOST OF
THE AREA HOWEVER WINDS WILL REMAIN MARGINAL. THE BEST CHANCE FOR
RED FLAG CONDITIONS OVER THE NORTHWEST LATE THIS AFTERNOON. 06Z
NAM/GFS SHOW SUSTAINED WINDS THIS AFTERNOON IN THE 10 TO 20 MPH
ACROSS THE NORTH WITH GOOD MIXING EXPECTED GUSTS IN THE NORTH
SHOULD REACH 25 MPH. AS THE COLD FRONT DROPS SOUTH INTO THE
NORTHERN FRINGE OF OUR CWA WINDS SHOULD SHIFT TO THE NORTH AND
FURTHER INCREASE WITH GUSTS 30 TO 40 MPH. CONSIDERING THE TIMING
OF THE FRONT AND MODEL TRENDS I DECIDED TO ISSUE A RED FLAG
WARNING FOR OUR SOUTHWEST NEBRASKA COUNTIES AND YUMA COUNTY
COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
COZ252.
NE...RED FLAG WARNING FROM NOON MDT /1 PM CDT/ TODAY TO 9 PM MDT /10
PM CDT/ THIS EVENING FOR NEZ079>081.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...DLF
AVIATION...DR
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 AM CDT WED OCT 3 2012
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 408 AM CDT WED OCT 3 2012
A COMPACT BUT STRONG STORM SYSTEM CONTINUED TO DEVELOP EARLY THIS
MORNING OVER WESTERN MONTANA. RAP ANALYSIS SHOWED A 90-KT JET
STREAK AT 400MB ROUNDING THE BASE OF THE DEVELOPING TROUGH AXIS.
ADDITIONAL JET STREAK ENERGY CONTINUED TO DIG SOUTHWARD TOWARD THE
BASE OF THE TROUGH. THE MID LEVEL COLD FRONT WAS MOVING TOWARD
YELLOWSTONE NATIONAL PARK AS OF 08Z. NEAR THE CENTER OF THIS
STORM...SNOW OBSERVATIONS WERE FOUND AT GREAT FALLS AND CUT BANK,
MONTANA WHERE TEMPERATURES CONTINUED TO FALL INTO THE LOWER 30S.
AHEAD OF THIS STORM SYSTEM...SKY WAS CLEAR ACROSS PRETTY MUCH THE
ENTIRE GREAT PLAINS. SURFACE LEE TROUGH EXTENDED FROM A WEAK LOW
CENTER (1003MB) JUST EAST OF CHADRON, NE SOUTH-SOUTHWESTWARD INTO
EASTERN COLORADO.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 408 AM CDT WED OCT 3 2012
THE STRONG COLD FRONT PUSHING SOUTH TODAY WILL REACH THE SOUTHERN
NEBRASKA PANHANDLE BY LATE AFTERNOON. A DOWNSLOPE WARM THERMAL
RIDGE WILL NOSE NORTHEAST THROUGH NORTHWEST KANSAS INTO CENTRAL
NEBRASKA...WHICH IS WHERE WARMEST SURFACE TEMPERATURES SHOULD BE
TODAY (WITH SCATTERED HIGHS IN THE 91 TO 93F RANGE)...MAINLY NORTH
OF THE DDC FORECAST AREA. ACROSS SOUTHWEST KANSAS...UPPER 80S SHOULD
BE COMMON FOR HIGHS WHICH WAS WHAT THE PREVIOUS FORECAST HAD...SO NO
CHANGE OF SIGNIFICANCE WAS MADE. SURFACE WINDS LATE AFTERNOON
SHOULD REACH 15 TO 18 KNOTS EAST OF A WAKEENEY TO LIBERAL LINE WHERE
LOW LEVEL PRESSURE GRADIENT WILL RESIDE. TIMING OF THE FRONT IS
COMING INTO BETTER FOCUS...AND WILL LEAN ON THE NAM12 FOR TIMING.
AT 06Z...FRONT SHOULD BE KNOCKING ON THE DOOR STEP OF THE DDC
FORECAST AREA (SYRACUSE TO WAKEENEY LINE). THE SUBSTANTIAL PRESSURE
RISES BEHIND THE FRONT COMBINED WITH THE GRADIENT ITSELF SHOULD
RESULT IN SURFACE WINDS OF 25 TO 28 KNOTS SUSTAINED FOR PROBABLY A
THREE-HOUR PERIOD. THIS WILL LIKELY WARRANT ISSUANCE OF A WIND
ADVISORY...BUT WILL HOLD OFF ON ISSUANCE OF ONE THIS FORECAST
CYCLE. WILL GO AHEAD AND KEEP THE 20 POPS IN FOR AREAS MAINLY NORTH
OF HIGHWAY 96 FOR LIGHT RAIN SHOWERS GIVEN SUCH STRONG LOW LEVEL
FRONTOGENESIS IN THE 06-12Z TIME FRAME TONIGHT. SREF MEANS AND
ECMWF MODEL DOES SHOW A SLIGHT QPF SIGNAL...BUT ABSENCE OF QUALITY
LOW LEVEL MOISTURE WILL BE AN ISSUE TO GENERATE ANYTHING MORE THAN
JUST A FEW HUNDREDTHS OF AN INCH OF PRECIPITATION SHOULD ANY RAIN
SHOWERS FORM AT ALL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 249 AM CDT WED OCT 3 2012
MEDIUM RANGE MODELS INDICATE A STRONG UPPER LEVEL TROUGH OF LOW
PRESSURE SWINGING EASTWARD OUT OF THE NORTHERN PLAINS INTO THE
WESTERN GREAT LAKES REGION THURSDAY. THIS SYSTEM WILL BRING THE
POSSIBILITY FOR PRECIP TO THE DAKOTAS, NEBRASKA, AND INTO THE UPPER
MIDWEST THURSDAY. ALTHOUGH AN ATTENDANT COLD FRONT IS PROJECTED TO
PUSH SOUTHEAST INTO AND ACROSS WESTERN KANSAS EARLY THURSDAY, LITTLE
IF ANY PRECIP WILL BE POSSIBLE ACROSS SOUTHWEST AND CENTRAL KANSAS
DUE TO THE LACK OF LOW/MID LEVEL MOISTURE AND INSTABILITY. HOWEVER,
A STRONG JET IS EXPECTED TO TRANSITION OUT OF THE NORTHERN AND
CENTRAL ROCKIES INTO THE WESTERN HIGH PLAINS THURSDAY PROVIDING
STRONG UPPER LEVEL DYNAMICS. SO, CANNOT RULE OUT AN OUTSIDE SLIGHT
CHANCE FOR LIGHT PRECIP AS FAR SOUTH AS CENTRAL KANSAS TO INCLUDE
THE I-70 CORRIDOR. OTHERWISE, GENERALLY DRY CONDITIONS ARE EXPECTED
ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS THROUGH FRIDAY AFTERNOON.
THERE IS A CHANCE FOR PRECIP FRIDAY NIGHT INTO EARLY SATURDAY AS A
SECONDARY UPPER LEVEL JET CORE EJECTS OUT OF THE ROCKIES INTO THE
WESTERN HIGH PLAINS. THIS WILL COINCIDE WITH A COOLING OF THE
ATMOSPHERE AT ALL LEVELS BRINGING GFS AND ECMWF SOUNDING PROFILES
TO NEAR SATURATION FRIDAY NIGHT INTO EARLY SATURDAY.
TEMPERATURES WILL BE WELL BELOW NORMAL THURSDAY IN WAKE OF A STRONG
COLD FRONT PUSHING SOUTHEAST ACROSS WESTERN KANSAS WEDNESDAY NIGHT.
STRONG COLD AIR ADVECTION SOUTHWARD INTO WESTERN KANSAS WILL LOWER
H85 TEMPERATURES DOWN INTO THE SINGLE DIGITS(C) ACROSS THE AREA
WITH NEAR 10C IN FAR SOUTHWESTERN KANSAS. TEMPERATURES ARE LIKELY
TO STRUGGLE TO REACH THE 60S(F) WITH MID TO UPPER 50S(F) POSSIBLE
FURTHER NORTH NEAR THE I-70 CORRIDOR. SIMILAR HIGH TEMPERATURES
ARE EXPECTED FRIDAY BEFORE ANOTHER SURGE OF COLDER AIR DROPS SOUTH
INTO WESTERN KANSAS EARLY IN THE WEEKEND. THIS WILL KEEP
TEMPERATURES DOWN BELOW NORMAL THROUGH VERY EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 614 AM CDT WED OCT 3 2012
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THROUGH LATE THIS
EVENING. AS FOR WINDS, A LEE SIDE TROUGH OF LOW PRESSURE WILL
STRENGTHEN ACROSS EXTREME EASTERN COLORADO TODAY. AS A RESULT,
SOUTH TO SOUTHWESTERLY WINDS OF 5 TO 15KT EARLY THIS MORNING WILL
INCREASE UP TO 15 TO 25KT BY EARLY THIS AFTERNOON. A STRONG COLD
FRONT IS THEN EXPECTED TO PUSH SOUTHEAST INTO AND ACROSS WESTERN
KANSAS TONIGHT. WINDS WILL BECOME NORTHERLY 25 TO 35KT BEHIND THE
FRONT...GENERALLY AFTER 06Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 46 62 42 / 0 10 0 10
GCK 87 45 62 42 / 0 10 0 10
EHA 88 45 61 42 / 0 10 0 0
LBL 88 47 62 43 / 0 10 0 0
HYS 87 45 61 40 / 0 20 10 10
P28 86 52 64 46 / 0 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...JJOHNSON
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
511 AM MDT WED OCT 3 2012
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 247 AM MDT WED OCT 3 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOWS A SHORTWAVE RIDGE
EXTENDING NORTH ACROSS NORTHWEST KANSAS AND CENTRAL NEBRASKA.
UPSTREAM A TROUGH IS DIGGING SOUTH INTO NORTHERN IDAHO AND
WESTERN MONTANA. AT THE SURFACE...LOW PRESSURE REMAINS IN PLACE
ACROSS THE HIGH PLAINS WITH A SURFACE COLD FRONT DEEPENING ACROSS
SOUTH DAKOTA...AND A SURFACE TROUGH AXIS EXTENDING JUST WEST OF
THE COLORADO/KANSAS STATE LINE.
VERY WARM TEMPERATURES ARE EXPECTED TODAY WITH HIGHS IN THE UPPER
80S/LOW 90S AS SOUTHERLY FLOW ADVECTS MUCH WARMER AIR INTO THE
REGION AHEAD OF THE APPROACHING COLD FRONT.
TONIGHT...THE COLD FRONT OVER SOUTH DAKOTA IS EXPECTED TO PUSH
SOUTH ACROSS THE CWA BY MIDNIGHT AS THE SHORTWAVE TROUGH DIGS
SOUTH AND EAST ACROSS THE NORTHERN PLAINS. WINDY CONDITIONS ARE
EXPECTED THIS EVENING AND OVERNIGHT BEHIND THE FRONT...AND WILL
APPROACH WIND ADVISORY CRITERIA WITH GUSTS POSSIBLY IN THE 40-45
MPH RANGE. I WAS NOT CONFIDENT ENOUGH TO GO THAT HIGH YET WITH
SOME DIFFERENCES BETWEEN GUIDANCE ON MAGNITUDE OF THE WINDS...AND
THE WINDOW FOR THESE CONDITIONS SEEMS TO BE FAIRLY BRIEF. A FEW
SHOWERS WILL BE POSSIBLE MAINLY IN THE 03Z- 09Z TIME FRAME WHEN
BEST LARGE SCALE ASCENT IS ADVERTISED. DUE TO THE SPEED AND
NORTHERN TRACK OF THE TROUGH AND MINIMAL MOISTURE...CONFIDENCE IS
LOW IN MEASURABLE PRECIP. I KEPT POPS LIMITED TO SLIGHT CHANCE
CATEGORY FOR NOW...AND CONSIDERED ONLY INCLUDING MENTION OF
SPRINKLES.
THURSDAY...COOLER TEMPERATURES ARE EXPECTED WITH HIGHS IN THE
50S/60S AND OVERNIGHT LOWS THURSDAY NIGHT IN THE MID 30S. WIND AND
INCREASING CLOUDS WILL LIMIT RADIATION COOLING THURSDAY
NIGHT...OTHERWISE I WOULD BE CONCERNED WITH HARD FREEZE CONDITIONS
BASED ON ADVERTISED H85 TEMPS IN THE 0C-3C RANGE. FOR NOW IT
LOOKS LIKE WE WILL BE IN THE UPPER LIMIT OF LOCAL FROST ADVISORY
CRITERIA.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 247 AM MDT WED OCT 3 2012
THE ANTICIPATED SIGNIFICANT WEATHER CHANGE STILL LOOKS ON TRACK
FOR THE WEEKEND AS A VIGOROUS UPPER LEVEL SHORT WAVE TROUGH IS
FORECAST TO SWEEP SOUTHEAST ACROSS THE CENTRAL PLAINS FRIDAY AND
SATURDAY. DYNAMICS FROM A 105 KT JET AT 250 MB WILL ENHANCE LIFT
FRIDAY NIGHT INTO SATURDAY MORNING WHEN BOTH THE GFS/EC FORECAST A
SATURATED LOWER ATMOSPHERE. GIVEN 850 MB TEMPS OF ZERO TO -2C AND
SATURATED AIR ABOVE -10C...ANTICIPATE LIGHT SNOW ACROSS THE
COLORADO COUNTIES SATURDAY MORNING AND A RAIN-SNOW MIX POSSIBLE
FURTHER EAST. GUIDANCE SUGGESTS LOW AND MID LEVELS WILL RAPIDLY
DRY OUT SATURDAY AFTERNOON AS THE JET AXIS AND UPPER TROUGH SLIDE
SOUTHEAST OF THE FORECAST AREA...ENDING PRECIP CHANCES.
850 MB TEMPERATURES OF 0 TO -2C ARE FORECAST SATURDAY MORNING...
WARMING ONLY A FEW DEGREES BY LATE AFTERNOON. HIGHS WILL HOLD IN THE
40S WHICH IS 25-30 DEGREES BELOW NORMAL. THE NORTHWEST THIRD OF THE
AREA SHOULD SEE MIN TEMPS SATURDAY IN THE 30-32 F RANGE AND BY
SUNDAY MORNING WITH LESS CLOUDS...MIN TEMPERATURES COULD DROP AS LOW
AS THE UPPER 20S...MAINLY IN THE NORTHWEST...WITH LOW 30S ELSEWHERE.
AFTERNOON HIGH TEMPERATURES WILL MODERATE SUNDAY AND MONDAY WITH
TEMPS STILL BELOW NORMAL BUT RETURNING TO THE 50S SUNDAY AND 60S
MONDAY. BOTH GFS/EC HINT AT ANOTHER COLD FRONT ARRIVING TUESDAY
WITH THE AIR MASS MOVING THROUGH RATHER QUICKLY...AND THE
POTENTIAL FOR PRECIPITATION AROUND MID WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 510 AM MDT WED OCT 3 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. SOUTHERLY WINDS AROUND 10KTS WILL SHIFT TO THE NORTH
AFTER SUNSET AND INCREASE AS A COLD FRONT MOVES THROUGH THE
REGION THIS EVENING. GUSTS AROUND 30KTS WILL BE POSSIBLE AT BOTH
TERMINALS. A FEW SHOWERS WILL BE POSSIBLE...HOWEVER COVERAGE LOOKS
TO BE LIMITED SO WILL NOT MENTION IN TAFS.
&&
.FIRE WEATHER...
ISSUED AT 247 AM MDT WED OCT 3 2012
RH VALUES LOOK TO DROP TO WITHIN RED FLAG CRITERIA OVER MOST OF
THE AREA HOWEVER WINDS WILL REMAIN MARGINAL...WITH THE BEST CHANCE
FOR RED FLAG CONDITIONS OVER THE NORTHWEST LATE THIS AFTERNOON.
WINDS WILL INCREASE THIS EVENING...HOWEVER BY THAT POINT RH SHOULD
RECOVER ABOVE CRITERIA. I DO NOT PLAN ON A RFW AT THIS
TIME...SINCE WE LIKELY WONT MEET THE 3HR REQUIREMENT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...DLF
AVIATION...DR
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1258 PM CDT WED OCT 3 2012
.AVIATION...18Z KGRI TAF
REST OF THIS AFTERNOON: VFR CLEAR. BREEZY S WINDS WILL GUST UP TO
30 KTS. ALL ELEMENTS HIGH CONFIDENCE.
TONIGHT: COLD FRONTAL PASSAGE NEAR 03Z. WINDS WILL SLACKEN
IMMEDIATELY AHEAD OF THE FRONT...THEN AN ABRUPT WINDSHIFT TO NNW.
WINDS WILL GUST TO 32 KTS...WITH POTENTIAL FOR AN ISOLATED G35.
WHILE VFR MID-LEVEL CIGS WILL MOVE IN AFTER FROPA...WE/RE NOTING
MVFR CIGS UPSTREAM OVER WY SEEPING INTO SD. THIS PROBABLY MAKES
IT INTO GRI TNGT...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN
18Z TAF. WHILE MODEL RH FIELDS SUPPORT THIS...OTHER GUIDANCE IS
NOT THERE YET. BOTTOM LINE...TAF MAY NEED MVFR/IFR CIGS. FOR NOW
MAINTAINED MENTION OF SCT010. CONFIDENCE IS HIGH ON WINDS/VSBYS
AND MID-LEVEL CIGS...BUT BELOW AVERAGE OF DEVELOPMENT/TIMING OF
LOW CIGS.
THU THROUGH 18Z: CURRENT EXPECTATION IS FOR CLEARING/VFR TO
DEVELOP. WINDS WILL CONTINUE TO GUST TO NEAR 30 KTS...BUT BEGIN TO
DECREASE AFTER 15Z. CONFIDENCE AVERAGE ALL ELEMENTS.
&&
.PREV DISCUSSION... /ISSUED 1115 AM CDT WED OCT 3 2012/
..ONE DAY OF SUNNY/BREEZY/VERY WARM CONDITIONS TODAY WILL BE
REPLACED BY DRASTIC 25-30F DOWNTURN IN TEMPS TOMORROW...
RED FLAG WARNING ISSUED AT 439 AM CONTINUES AS POSTED. IT/S
MARGINAL BASED ON EXACT CRITERIA...BUT CONDITIONS WILL CERTAINLY
BE THREATENING. BEST CHANCE OF VERIFYING /3 CONSECUTIVE HRS/ WILL
BE W OF A LINE FROM ODX-HDE...WHERE DWPTS IN THE MID 30S WILL EDGE
IN WITH EWD PROGRESSION OF LEE TROF IMMEDIATELY AHEAD OF THE
FRONT.
FRONT IS CURRENTLY LOCATED OVER CENTRAL WY INTO WRN SD. PRESENT
INDICATIONS VIA THE 12Z NAM/15Z RAP ARE THAT THE FRONT WILL ENTER
DAWSON/VALLEY COUNTIES IN THE 7-8 PM TIME-FRAME...BE TO GRI BY 10
PM AND SE OF THE FCST AREA BY 2 AM.
WITH LONGWAVE TROF OVER THE ERN USA...THE WARM SECTOR IS VERY DRY.
MOST OF THE CLOUD COVER IS POST-FRONTAL. PCPN CHANCES AHEAD OF THE
FRONT WILL BE NIL.
TEMPS: 12Z LBF SOUNDING OFFERS A MAX TEMP OF 89F. ADJUSTED TEMPS
SLIGHTLY USING BIAS CORRECTED CONSENSUS MOS. THIS RAISED TEMPS
A COUPLE DEG W OF HWY 281 AND LOWERED THEM E OF HWY 281. ALSO
ADJUSTED TEMP CURVES TO ACCOUNT FOR MORE RAPID UPGLIDE THRU 18Z.
WINDS: MEAN SPEEDS IN THE MIXED LAYER WILL AVERAGE 25 KTS WITH A
MAX OF 31 KTS VIA BUFKIT. SO WHILE SFC WINDS WILL AVERAGE 15-25
MPH WITH G30 ...ONE-TIME PEAK GUSTS WILL PROBABLY REACH 34-37 MPH.
WINDS FROM 4 AM GID FCST ISSUANCE LOOK GOOD.
UPDATED FCST HAS ALREADY POSTED TO THE WEB. UPDATED ZFP/AFM/PFM
WILL POST SHORTLY.
PREV DISCUSSION... /ISSUED 417 AM CDT WED OCT 3 2012/
SHORT TERM...TODAY THROUGH 12Z SATURDAY. MAIN FORECAST CHALLENGE
CONTINUES TO BE THE APPROACHING COLD FRONT AND THE ASSOCIATED
WEATHER RELATED PHENOMENA. THE WIND FIELD COUPLED WITH LOW
RELATIVE HUMIDITY VALUES AHEAD OF THE COLD FRONT WILL PRESENT FIRE
WEATHER CONCERNS FOR TODAY. GOING WITH A RED FLAG WARNING FOR OUR
NEBRASKA COUNTIES THIS AFTERNOON.
TEMPERATURES AHEAD OF THE COLD FRONT WILL GET INTO THE MID 80S.
SOUTHERLY WIND SPEEDS AHEAD OF THE COLD FRONT WILL RANGE FROM 15 TO
20 MPH WITH GUSTS CLOSER TO 30 MPH. DEWPOINTS BEING IN THE MID TO
UPPER 30S AND LOWER 40S THIS AFTERNOON WILL PRODUCE RELATIVE
HUMIDITY VALUES IN THE UPPER TEENS AND LOWER 20S FOR A MAJORITY OF
THE CWA. GIVEN THESE CONDITIONS...A RED FLAG WAS WARRANTED THIS
AFTERNOON AND ONGOING THROUGH THE EARLY EVENING HOURS. THE TIMING
OF THE COLD FRONT COULD BE A KEY ISSUE TODAY WITH REGARDS TO FIRE
WEATHER CONCERNS. IF THE BOUNDARY SPEEDS UP ANYMORE THAN WHAT IS
FORECAST NOW...THESE CONDITIONS MIGHT NOT BE MET AS RELATIVE
HUMIDITY VALUES WILL QUICKLY BEGIN TO RISE AS THE FRONT PASSES.
THIS IS NOT A SLAM-DUNK EVENT...MAINLY BECAUSE THE TIMING OF THE
FRONT HAS NOT BEEN VERY CONSISTENT OVER THE LAST SEVERAL DAYS SO
CONFIDENCE IS LEANING TOWARDS MARGINAL. WITH THE BOUNDARY BEING
LESS THAN 24 HOURS FROM APPROACHING...THE GUIDANCE SHOULD HAVE A
DECENT GRIP ON THE SITUATION SO WENT WITH THE WARNING.
AS A RESULT OF LACKING MOISTURE CURRENTLY PROGGED TO BE IN THE
ATMOSPHERE TODAY...PRECIPITATION CHANCES BEHIND THE FRONT HAVE
DIMINISHED SIGNIFICANTLY ACROSS THE CWA FROM PREVIOUS FORECAST. THIS
ANALYSIS FALLS IN LINE WITH THE CRITERIA FOR FIRE WEATHER TODAY AS
FORECAST SOUNDINGS INDICATE A RATHER DRY ATMOSPHERE WITH AN
INVERTED-V PROFILE...WHERE THE LOWER LEVELS ARE ESPECIALLY DRY.
FURTHERMORE...CROSS SECTIONS OVER TIME SHOW VERY LITTLE MOISTURE IN
THE ATMOSPHERE DURING THE PASSAGE OF THE FRONT. PRECIPITATION
CHANCES ARE BEST BETWEEN 06Z AND 12Z WHERE MOISTURE BECOMES
EVIDENT...ALBEIT THESE CHANCES ARE STILL NOT VERY GOOD AS SLIGHT
CHANCES ARE CURRENTLY FORECAST. A BREAK IN PRECIPITATION CHANCES
OCCURS THURSDAY THROUGH THURSDAY NIGHT.
FRIDAY/FRIDAY NIGHT IS VERY INCONSISTENT BETWEEN THE MODELS AS FAR
AS PRECIP CHANCES GO. WITH THAT SAID...A CONVERGENCE ZONE IN THE
LOWER LEVELS WITH PLENTY OF MOISTURE IS FORECAST TO SET UP OVER THE
OUTLOOK AREA FRIDAY. TIMING AND COVERAGE WILL BE THE MAIN CHALLENGE
AS MODELS VARY IN OUTPUT. CONFIDENCE IS LOW FOR PRECIPITATION AT
THIS TIME AND SLIGHT CHANCES WILL BE FORECAST.
TEMPERATURES ON SATURDAY MORNING ARE GOING TO BE NEAR THE LOWER
30S FOR A MAJORITY OF THE CWA...HOWEVER...PRECIPITATION CHANCES
AND CLOUD COVER COULD PRODUCE SOME WARMER TEMPERATURES OVERNIGHT
THAN WHAT IS CURRENTLY FORECAST. OVERALL...ITS GOING TO BE A
RATHER CHILLY NIGHT ACROSS THE OUTLOOK AREA.
LONG TERM...SATURDAY THROUGH TUESDAY. THE BIG STORY WILL CENTER
AROUND THE COLD TEMPERATURES...WHICH WILL BE THE COLDEST WEATHER WE
HAVE SEEN SINCE EARLY MARCH. LOW TEMPERATURES MAY FALL BELOW
FREEZING AS EARLY AS SATURDAY MORNING...BUT ARE EVEN MORE LIKELY TO
FALL BELOW FREEZING BY SATURDAY NIGHT INTO SUNDAY MORNING. OUR
CURRENT FORECAST IS CALLING FOR LOWS SATURDAY NIGHT/SUNDAY MORNING
TO RANGE FROM THE MID 20S AROUND ORD...TO THE UPPER 20S IN THE TRI
CITIES...TO AROUND 30 IN NORTHERN KANSAS. THIS WILL MARK THE END OF
THE GROWING SEASON...WHICH FOR HASTINGS AND MOST LOCATIONS SOUTH OF
HASTINGS INTO NORTHERN KANSAS WILL BE THE LONGEST GROWING SEASON ON
RECORD AT AROUND 210 CONSECUTIVE DAYS WITH LOW TEMPERATURES ABOVE
32F. THE LAST TIME HASTINGS WAS 32F OR BELOW WAS BACK ON MARCH 9TH.
GRAND ISLAND HAD THEIR LAST FREEZE A LITTLE LATER ON APRIL 11TH AND
THUS THE GRAND ISLAND GROWING SEASON IS NOT EXPECTED TO BE A
RECORD...BUT IT SHOULD STILL BE AROUND THE 15TH OR 16TH LONGEST
GROWING SEASON ON RECORD.
IN ADDITION TO THE COLD OVERNIGHT LOWS...HIGH TEMPERATURES SATURDAY
ARE ONLY FORECAST TO BE AROUND 50 DEGREES WITH COOL AND DRY HIGH
PRESSURE OVERHEAD. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
TUESDAY BUT EXPECT HIGHS WILL GRADUALLY MODERATE INTO THE MID AND
UPPER 50S ON SUNDAY AND THEN 60S BY MONDAY AND TUESDAY. NORMAL HIGH
TEMPERATURES WOULD BE RIGHT AROUND 70F. DRY WEATHER IS EXPECTED TO
PERSIST THROUGH THE EXTENDED PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR NEZ039>041-
046>049-060>064-072>077-082>087.
KS...NONE.
&&
$$
AVIATION: HALBLAUB
UPDATE: HALBLAUB
SHORT TERM: GUERRERO
LONG TERM: WESELY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1115 AM CDT WED OCT 3 2012
.UPDATE...
...ONE DAY OF SUNNY/BREEZY/VERY WARM CONDITIONS TODAY WILL BE
REPLACED BY DRASTIC 25-30F DOWNTURN IN TEMPS TOMORROW...
RED FLAG WARNING ISSUED AT 439 AM CONTINUES AS POSTED. IT/S
MARGINAL BASED ON EXACT CRITERIA...BUT CONDITIONS WILL CERTAINLY
BE THREATENING. BEST CHANCE OF VERIFYING /3 CONSECUTIVE HRS/ WILL
BE W OF A LINE FROM ODX-HDE...WHERE DWPTS IN THE MID 30S WILL EDGE
IN WITH EWD PROGRESSION OF LEE TROF IMMEDIATELY AHEAD OF THE
FRONT.
FRONT IS CURRENTLY LOCATED OVER CENTRAL WY INTO WRN SD. PRESENT
INDICATIONS VIA THE 12Z NAM/15Z RAP ARE THAT THE FRONT WILL ENTER
DAWSON/VALLEY COUNTIES IN THE 7-8 PM TIME-FRAME...BE TO GRI BY 10
PM AND SE OF THE FCST AREA BY 2 AM.
WITH LONGWAVE TROF OVER THE ERN USA...THE WARM SECTOR IS VERY DRY.
MOST OF THE CLOUD COVER IS POST-FRONTAL. PCPN CHANCES AHEAD OF THE
FRONT WILL BE NIL.
TEMPS: 12Z LBF SOUNDING OFFERS A MAX TEMP OF 89F. ADJUSTED TEMPS
SLIGHTLY USING BIAS CORRECTED CONSENSUS MOS. THIS RAISED TEMPS
A COUPLE DEG W OF HWY 281 AND LOWERED THEM E OF HWY 281. ALSO
ADJUSTED TEMP CURVES TO ACCOUNT FOR MORE RAPID UPGLIDE THRU 18Z.
WINDS: MEAN SPEEDS IN THE MIXED LAYER WILL AVERAGE 25 KTS WITH A
MAX OF 31 KTS VIA BUFKIT. SO WHILE SFC WINDS WILL AVERAGE 15-25
MPH WITH G30 ...ONE-TIME PEAK GUSTS WILL PROBABLY REACH 34-37 MPH.
WINDS FROM 4 AM GID FCST ISSUANCE LOOK GOOD.
UPDATED FCST HAS ALREADY POSTED TO THE WEB. UPDATED ZFP/AFM/PFM
WILL POST SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 551 AM CDT WED OCT 3 2012/
AVIATION...12Z KGRI TAF. A SOUTH WIND WILL QUICKLY INCREASE
THROUGH THE MORNING AND WILL BE ESPECIALLY GUSTY BY EARLY
AFTERNOON. A STRONG COLD FRONT WILL SWING THROUGH DURING THE
EVENING...LIKELY JUST AFTER 10 PM. STRONG NORTHWEST WINDS ARE
EXPECTED BEHIND THE FRONT AND SHOULD LAST THROUGH MUCH OF THE
NIGHT. CLEAR SKIES THIS MORNING WILL GIVE WAY TO SOME MID AND HIGH
CLOUDS THIS EVENING. THERE MAY ALSO BE A SCATTERED LOW DECK OF
STRATUS CLOUDS BEHIND THE COLD FRONT THIS EVENING. WILL CONTINUE
TO CALL FOR VFR CONDITIONS...BUT WILL NEED TO MONITOR HOW LOW CLOUDS
DEVELOP BEHIND THE FRONT THIS EVENING.
PREV DISCUSSION... /ISSUED 417 AM CDT WED OCT 3 2012/
SHORT TERM...TODAY THROUGH 12Z SATURDAY. MAIN FORECAST CHALLENGE
CONTINUES TO BE THE APPROACHING COLD FRONT AND THE ASSOCIATED
WEATHER RELATED PHENOMENA. THE WIND FIELD COUPLED WITH LOW
RELATIVE HUMIDITY VALUES AHEAD OF THE COLD FRONT WILL PRESENT FIRE
WEATHER CONCERNS FOR TODAY. GOING WITH A RED FLAG WARNING FOR OUR
NEBRASKA COUNTIES THIS AFTERNOON.
TEMPERATURES AHEAD OF THE COLD FRONT WILL GET INTO THE MID 80S.
SOUTHERLY WIND SPEEDS AHEAD OF THE COLD FRONT WILL RANGE FROM 15 TO
20 MPH WITH GUSTS CLOSER TO 30 MPH. DEWPOINTS BEING IN THE MID TO
UPPER 30S AND LOWER 40S THIS AFTERNOON WILL PRODUCE RELATIVE
HUMIDITY VALUES IN THE UPPER TEENS AND LOWER 20S FOR A MAJORITY OF
THE CWA. GIVEN THESE CONDITIONS...A RED FLAG WAS WARRANTED THIS
AFTERNOON AND ONGOING THROUGH THE EARLY EVENING HOURS. THE TIMING
OF THE COLD FRONT COULD BE A KEY ISSUE TODAY WITH REGARDS TO FIRE
WEATHER CONCERNS. IF THE BOUNDARY SPEEDS UP ANYMORE THAN WHAT IS
FORECAST NOW...THESE CONDITIONS MIGHT NOT BE MET AS RELATIVE
HUMIDITY VALUES WILL QUICKLY BEGIN TO RISE AS THE FRONT PASSES.
THIS IS NOT A SLAM-DUNK EVENT...MAINLY BECAUSE THE TIMING OF THE
FRONT HAS NOT BEEN VERY CONSISTENT OVER THE LAST SEVERAL DAYS SO
CONFIDENCE IS LEANING TOWARDS MARGINAL. WITH THE BOUNDARY BEING
LESS THAN 24 HOURS FROM APPROACHING...THE GUIDANCE SHOULD HAVE A
DECENT GRIP ON THE SITUATION SO WENT WITH THE WARNING.
AS A RESULT OF LACKING MOISTURE CURRENTLY PROGGED TO BE IN THE
ATMOSPHERE TODAY...PRECIPITATION CHANCES BEHIND THE FRONT HAVE
DIMINISHED SIGNIFICANTLY ACROSS THE CWA FROM PREVIOUS FORECAST. THIS
ANALYSIS FALLS IN LINE WITH THE CRITERIA FOR FIRE WEATHER TODAY AS
FORECAST SOUNDINGS INDICATE A RATHER DRY ATMOSPHERE WITH AN
INVERTED-V PROFILE...WHERE THE LOWER LEVELS ARE ESPECIALLY DRY.
FURTHERMORE...CROSS SECTIONS OVER TIME SHOW VERY LITTLE MOISTURE IN
THE ATMOSPHERE DURING THE PASSAGE OF THE FRONT. PRECIPITATION
CHANCES ARE BEST BETWEEN 06Z AND 12Z WHERE MOISTURE BECOMES
EVIDENT...ALBEIT THESE CHANCES ARE STILL NOT VERY GOOD AS SLIGHT
CHANCES ARE CURRENTLY FORECAST. A BREAK IN PRECIPITATION CHANCES
OCCURS THURSDAY THROUGH THURSDAY NIGHT.
FRIDAY/FRIDAY NIGHT IS VERY INCONSISTENT BETWEEN THE MODELS AS FAR
AS PRECIP CHANCES GO. WITH THAT SAID...A CONVERGENCE ZONE IN THE
LOWER LEVELS WITH PLENTY OF MOISTURE IS FORECAST TO SET UP OVER THE
OUTLOOK AREA FRIDAY. TIMING AND COVERAGE WILL BE THE MAIN CHALLENGE
AS MODELS VARY IN OUTPUT. CONFIDENCE IS LOW FOR PRECIPITATION AT
THIS TIME AND SLIGHT CHANCES WILL BE FORECAST.
TEMPERATURES ON SATURDAY MORNING ARE GOING TO BE NEAR THE LOWER
30S FOR A MAJORITY OF THE CWA...HOWEVER...PRECIPITATION CHANCES
AND CLOUD COVER COULD PRODUCE SOME WARMER TEMPERATURES OVERNIGHT
THAN WHAT IS CURRENTLY FORECAST. OVERALL...ITS GOING TO BE A
RATHER CHILLY NIGHT ACROSS THE OUTLOOK AREA.
LONG TERM...SATURDAY THROUGH TUESDAY. THE BIG STORY WILL CENTER
AROUND THE COLD TEMPERATURES...WHICH WILL BE THE COLDEST WEATHER WE
HAVE SEEN SINCE EARLY MARCH. LOW TEMPERATURES MAY FALL BELOW
FREEZING AS EARLY AS SATURDAY MORNING...BUT ARE EVEN MORE LIKELY TO
FALL BELOW FREEZING BY SATURDAY NIGHT INTO SUNDAY MORNING. OUR
CURRENT FORECAST IS CALLING FOR LOWS SATURDAY NIGHT/SUNDAY MORNING
TO RANGE FROM THE MID 20S AROUND ORD...TO THE UPPER 20S IN THE TRI
CITIES...TO AROUND 30 IN NORTHERN KANSAS. THIS WILL MARK THE END OF
THE GROWING SEASON...WHICH FOR HASTINGS AND MOST LOCATIONS SOUTH OF
HASTINGS INTO NORTHERN KANSAS WILL BE THE LONGEST GROWING SEASON ON
RECORD AT AROUND 210 CONSECUTIVE DAYS WITH LOW TEMPERATURES ABOVE
32F. THE LAST TIME HASTINGS WAS 32F OR BELOW WAS BACK ON MARCH 9TH.
GRAND ISLAND HAD THEIR LAST FREEZE A LITTLE LATER ON APRIL 11TH AND
THUS THE GRAND ISLAND GROWING SEASON IS NOT EXPECTED TO BE A
RECORD...BUT IT SHOULD STILL BE AROUND THE 15TH OR 16TH LONGEST
GROWING SEASON ON RECORD.
IN ADDITION TO THE COLD OVERNIGHT LOWS...HIGH TEMPERATURES SATURDAY
ARE ONLY FORECAST TO BE AROUND 50 DEGREES WITH COOL AND DRY HIGH
PRESSURE OVERHEAD. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH
TUESDAY BUT EXPECT HIGHS WILL GRADUALLY MODERATE INTO THE MID AND
UPPER 50S ON SUNDAY AND THEN 60S BY MONDAY AND TUESDAY. NORMAL HIGH
TEMPERATURES WOULD BE RIGHT AROUND 70F. DRY WEATHER IS EXPECTED TO
PERSIST THROUGH THE EXTENDED PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR NEZ039>041-
046>049-060>064-072>077-082>087.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...GUERRERO
LONG TERM/AVIATION...WESELY