Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 10/15/12
AREA FORECAST DISCUSSION
NWS MIAMI FL
145 PM EDT SAT OCT 13 2012
.AVIATION...
ISOLATED SHRAS HAVE PUSHED WELL INLAND AND AWAY FROM THE EAST
COAST TERMINALS AS NORTHEAST WINDS HAVE BECOME GUSTY. BELIEVE ANY
FURTHER SHRA ACTIVITY WILL NOT RESTRICT ANY OF THE TERMINALS.
SLIGHTLY DEEPER MOISTURE WILL BEGIN TO POOL INTO THE SOUTH FLORIDA
AREA TOWARD THE END OF THE TAF PERIOD DUE TO REMNANTS FROM PATTY.
LEFT ANY MENTION OF VCSH OUT OF TAFS FOR NOW. IN THE MEAN TIME,
NORTHEAST TO EAST-NORTHEAST FLOW WILL DOMINATE.
&&
.PREV DISCUSSION... /ISSUED 1051 AM EDT SAT OCT 13 2012/
UPDATE...
NO MAJOR UPDATES ARE ANTICIPATED THIS MORNING AS THE PREVIOUS
FORECAST PACKAGE REMAINS ON TRACK. WE DID SLIGHTLY ADJUST TO
GRIDDED TEMPERATURE DATABASE BASED ON THE LATEST OBSERVATIONS THIS
MORNING...WHICH WERE RUNNING SLIGHTLY COOLER INLAND THAN WHAT WAS
FORECAST. THE LATEST RADAR LOOP SHOWED ISOLATED TO SCATTERED
SHOWERS SPREADING ASHORE ALONG PORTIONS OF THE EAST COAST AREAS
WITHIN THE BREEZY NE FLOW. THE LATEST HRRR MODEL REFLECTIVITIES
INITIALIZED WELL WITH THIS PATTERN AND SHOWED A SIMILAR TREND
CONTINUING THROUGH THE REMAINDER OF THE DAY. 85/AG
PREV DISCUSSION... /ISSUED 733 AM EDT SAT OCT 13 2012/
AVIATION...
STRONG NORTHEAST FLOW WILL CONTINUE TO BUILD INTO THE
REGION THIS MORNING AND IS EXPECTED TO PERSIST THROUGH THE DAY.
STRATOCUMULUS IN THE 3 KFT TO 6 KFT RANGE WITH EMBEDDED SHOWERS WILL
CONTINUE TO STREAM SOUTHWEST ACROSS THE ATLANTIC WATERS WITH THE
EAST COAST TAF SITES EXPERIENCING BRIEF PASSING SHOWERS FROM TIME TO
TIME WITH GUSTS TO NEAR 30 KNOTS OCCASIONALLY WITH A PASSING SHOWER
WITH VERY BRIEF SUB-VFR CONDITIONS POSSIBLE.
PREV DISCUSSION... /ISSUED 452 AM EDT SAT OCT 13 2012/
UPDATE...SHOWERS HAVE INCREASED IN COVERAGE ACROSS THE ATLANTIC
WATERS AND IR SATELLITE IMAGERY SHOWS A BAND OF MOISTURE EXTENDING
ACROSS GRAND BAHAMA AND TO THE NORTH WITH MOVEMENT TOWARDS SOUTH
FLORIDA. GIVEN THIS CURRENT TREND, HAVE UPDATED THE POPS INTO THE
SCATTERED CATEGORY FOR THE INTERIOR/EAST COAST TODAY ALONG WITH
INCREASING SKY COVER AS WELL. /GREGORIA
PREV DISCUSSION... /ISSUED 319 AM EDT SAT OCT 13 2012/
WINDY THIS WEEKEND WITH A HIGH RISK OF RIP CURRENTS ATLANTIC COAST...
FEW FAST MOVING SHOWERS EXPECTED, FOCUSED EAST COAST, BECOMING
SCATTERED SUNDAY WITH A SLIGHT CHANCE OF THUNDERSTORMS...
DISCUSSION...
THE PRESSURE GRADIENT WILL CONTINUE TIGHT ACROSS SOUTH FLORIDA
THROUGH SUNDAY, DUE TO STRONG HIGH PRESSURE OVER THE MID ATLANTIC
STATES AND T.D. PATTY EAST OF THE BAHAMAS, WHICH IS FORECAST BY NHC
TO DISSIPATE INTO A REMNANT LOW BY THIS EVENING WHILE MOVING SW. THE
RESULT ACROSS SOUTH FL WILL BE WINDY CONDITIONS THROUGH SUNDAY,
ESPECIALLY ALONG THE ATLANTIC COAST, ALONG WITH INCREASING MOISTURE
FROM THE EAST. AS THE REMNANTS OF PATTY MOVE OVER THE STRAITS AND
CUBA SUN-MON, MOISTURE WILL CONTINUE TO INCREASE WELL NORTH OF THIS
FEATURE. THE PWAT IS FORECAST TO INCREASE FROM AROUND AN INCH NOW TO
1.6-1.8" BY SUN AFTERNOON. THIS WILL LEAD TO A BETTER CHANCE OF FAST
MOVING SHOWERS SUN-SUN NIGHT. FORECAST SOUNDINGS SHOW THE CAP IN
PLACE NOW ERODING WITH MORE INSTABILITY, SO CANNOT RULE OUT A TSTORM
OR TWO AS WELL SO PLACED A SLIGHT CHANCE IN THE FORECAST SUN-MON.
STRONG RIP CURRENTS ARE LIKELY ALONG THE ATLANTIC BEACHES THROUGH
THE WEEKEND. MINOR COASTAL FLOODING WILL BE POSSIBLE IN THE MORE
VULNERABLE LOCALES ALONG THE ATLANTIC COAST, DUE TO A COMBINATION OF
HIGHER THAN NORMAL TIDES AND THE STRONG ONSHORE WIND FLOW. WILL
CONTINUE TO HIGHLIGHT THIS, ESPECIALLY THE RIPS WHICH ARE THE
BIGGEST THREAT.
WINDS BEGIN TO WEAKEN SUN NIGHT-MON AS THE ATLANTIC HIGH MOVES EAST.
BOTH GFS/ECMWF SHOW A SHORTWAVE TROUGH MOVING ACROSS THE EASTERN
STATES MON NIGHT-TUE. THIS IS FORECAST TO TAKE T.S. RAFAEL, NOW OVER
THE EASTERN CARIBBEAN, ON A NNW TRACK THEN RECURVING OUT TO SEA
TOWARDS BERMUDA AS PER NHC. LOCALLY, A WEAKENING COLD FRONTAL
BOUNDARY WILL MOVE INTO SOUTH FL MON NIGHT AND MOVE JUST SOUTH OF
THE AREA TUE-WED WITH HIGH PRESSURE RE-BUILDING TO THE NORTH. THIS
WILL LEAD TO A DECREASING MOISTURE TREND SO WILL CONTINUE WITH LOW
POPS THIS PERIOD. SO THE MID/LATE PERIOD NEXT WEEK LOOKS RATHER
TRANQUIL WITH NO MAJOR WEATHER SYSTEMS EXPECTED. HUMIDITY WILL
GRADUALLY INCREASE OVER THE NEXT FEW DAYS BUT IT NEVER GETS OUT OF
HAND.
LOOKING WAY OUT INTO THE EXTENDED FOR NEXT WEEKEND - ECWMF AND GFS
BOTH SHOW A DEEPENING MID/UPPER CLOSED LOW MOVING FROM THE GREAT
LAKE TO NEW ENGLAND. THE 12.12Z ECMWF AMPLIFIED THE TROUGH,
SENDING A STRONG COLD FRONT ACROSS SOUTH FL WITH DEWPOINTS FALLING
INTO THE 40S AND 50S! HOWEVER, THE LATEST ECMWF RUN IS NOT AS
STRONG AND THE LATEST GFS RUN IS NOT AS AGGRESSIVE WITH THE
TROUGH, BRINGING A COLD FRONT THROUGH BRIEFLY NEXT WEEKEND WITH A
QUICK TURN OF THE WINDS TO THE NORTHEAST, KEEPING CONDITIONS WARM
AND RATHER HUMID. NO SIGNIFICANT WEATHER IS EXPECTED THROUGH THE
PERIOD.
MARINE...OBS SHOW SUSTAINED WINDS NEAR 20 KT ACROSS THE WATERS.
WILL CONTINUE THE SMALL CRAFT ADVISORY FOR THE ATLANTIC, BISCAYNE
BAY AND THE LAKE...AND ADD THE OFFSHORE GULF WATERS AS WELL. WINDS
WILL STAY UP THROUGH TONIGHT THEN BEGIN TO GRADUALLY SUBSIDE SUN-
MON. SEAS WILL CONTINUE AT 7 FT OR HIGHER ACROSS THE ATLANTIC
THROUGH SUNDAY BEFORE GRADUALLY SUBSIDING.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN WELL
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 87 76 87 / 20 40 30 30
FORT LAUDERDALE 78 88 79 87 / 20 40 40 30
MIAMI 79 88 77 88 / 20 40 40 30
NAPLES 72 90 75 89 / 10 30 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH SUNDAY EVENING FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR BISCAYNE BAY-
LAKE OKEECHOBEE.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR COASTAL WATERS
FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL
WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING
FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR GULF WATERS FROM
CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
1051 AM EDT SAT OCT 13 2012
.UPDATE...
NO MAJOR UPDATES ARE ANTICIPATED THIS MORNING AS THE PREVIOUS
FORECAST PACKAGE REMAINS ON TRACK. WE DID SLIGHTLY ADJUST TO
GRIDDED TEMPERATURE DATABASE BASED ON THE LATEST OBSERVATIONS THIS
MORNING...WHICH WERE RUNNING SLIGHTLY COOLER INLAND THAN WHAT WAS
FORECAST. THE LATEST RADAR LOOP SHOWED ISOLATED TO SCATTERED
SHOWERS SPREADING ASHORE ALONG PORTIONS OF THE EAST COAST AREAS
WITHIN THE BREEZY NE FLOW. THE LATEST HRRR MODEL REFLECTIVITIES
INITIALIZED WELL WITH THIS PATTERN AND SHOWED A SIMILAR TREND
CONTINUING THROUGH THE REMAINDER OF THE DAY. 85/AG
&&
.PREV DISCUSSION... /ISSUED 733 AM EDT SAT OCT 13 2012/
AVIATION...
STRONG NORTHEAST FLOW WILL CONTINUE TO BUILD INTO THE
REGION THIS MORNING AND IS EXPECTED TO PERSIST THROUGH THE DAY.
STRATOCUMULUS IN THE 3 KFT TO 6 KFT RANGE WITH EMBEDDED SHOWERS WILL
CONTINUE TO STREAM SOUTHWEST ACROSS THE ATLANTIC WATERS WITH THE
EAST COAST TAF SITES EXPERIENCING BRIEF PASSING SHOWERS FROM TIME TO
TIME WITH GUSTS TO NEAR 30 KNOTS OCCASIONALLY WITH A PASSING SHOWER
WITH VERY BRIEF SUB-VFR CONDITIONS POSSIBLE.
PREV DISCUSSION... /ISSUED 452 AM EDT SAT OCT 13 2012/
UPDATE...SHOWERS HAVE INCREASED IN COVERAGE ACROSS THE ATLANTIC
WATERS AND IR SATELLITE IMAGERY SHOWS A BAND OF MOISTURE EXTENDING
ACROSS GRAND BAHAMA AND TO THE NORTH WITH MOVEMENT TOWARDS SOUTH
FLORIDA. GIVEN THIS CURRENT TREND, HAVE UPDATED THE POPS INTO THE
SCATTERED CATEGORY FOR THE INTERIOR/EAST COAST TODAY ALONG WITH
INCREASING SKY COVER AS WELL. /GREGORIA
PREV DISCUSSION... /ISSUED 319 AM EDT SAT OCT 13 2012/
WINDY THIS WEEKEND WITH A HIGH RISK OF RIP CURRENTS ATLANTIC COAST...
FEW FAST MOVING SHOWERS EXPECTED, FOCUSED EAST COAST, BECOMING
SCATTERED SUNDAY WITH A SLIGHT CHANCE OF THUNDERSTORMS...
DISCUSSION...
THE PRESSURE GRADIENT WILL CONTINUE TIGHT ACROSS SOUTH FLORIDA
THROUGH SUNDAY, DUE TO STRONG HIGH PRESSURE OVER THE MID ATLANTIC
STATES AND T.D. PATTY EAST OF THE BAHAMAS, WHICH IS FORECAST BY NHC
TO DISSIPATE INTO A REMNANT LOW BY THIS EVENING WHILE MOVING SW. THE
RESULT ACROSS SOUTH FL WILL BE WINDY CONDITIONS THROUGH SUNDAY,
ESPECIALLY ALONG THE ATLANTIC COAST, ALONG WITH INCREASING MOISTURE
FROM THE EAST. AS THE REMNANTS OF PATTY MOVE OVER THE STRAITS AND
CUBA SUN-MON, MOISTURE WILL CONTINUE TO INCREASE WELL NORTH OF THIS
FEATURE. THE PWAT IS FORECAST TO INCREASE FROM AROUND AN INCH NOW TO
1.6-1.8" BY SUN AFTERNOON. THIS WILL LEAD TO A BETTER CHANCE OF FAST
MOVING SHOWERS SUN-SUN NIGHT. FORECAST SOUNDINGS SHOW THE CAP IN
PLACE NOW ERODING WITH MORE INSTABILITY, SO CANNOT RULE OUT A TSTORM
OR TWO AS WELL SO PLACED A SLIGHT CHANCE IN THE FORECAST SUN-MON.
STRONG RIP CURRENTS ARE LIKELY ALONG THE ATLANTIC BEACHES THROUGH
THE WEEKEND. MINOR COASTAL FLOODING WILL BE POSSIBLE IN THE MORE
VULNERABLE LOCALES ALONG THE ATLANTIC COAST, DUE TO A COMBINATION OF
HIGHER THAN NORMAL TIDES AND THE STRONG ONSHORE WIND FLOW. WILL
CONTINUE TO HIGHLIGHT THIS, ESPECIALLY THE RIPS WHICH ARE THE
BIGGEST THREAT.
WINDS BEGIN TO WEAKEN SUN NIGHT-MON AS THE ATLANTIC HIGH MOVES EAST.
BOTH GFS/ECMWF SHOW A SHORTWAVE TROUGH MOVING ACROSS THE EASTERN
STATES MON NIGHT-TUE. THIS IS FORECAST TO TAKE T.S. RAFAEL, NOW OVER
THE EASTERN CARIBBEAN, ON A NNW TRACK THEN RECURVING OUT TO SEA
TOWARDS BERMUDA AS PER NHC. LOCALLY, A WEAKENING COLD FRONTAL
BOUNDARY WILL MOVE INTO SOUTH FL MON NIGHT AND MOVE JUST SOUTH OF
THE AREA TUE-WED WITH HIGH PRESSURE RE-BUILDING TO THE NORTH. THIS
WILL LEAD TO A DECREASING MOISTURE TREND SO WILL CONTINUE WITH LOW
POPS THIS PERIOD. SO THE MID/LATE PERIOD NEXT WEEK LOOKS RATHER
TRANQUIL WITH NO MAJOR WEATHER SYSTEMS EXPECTED. HUMIDITY WILL
GRADUALLY INCREASE OVER THE NEXT FEW DAYS BUT IT NEVER GETS OUT OF
HAND.
LOOKING WAY OUT INTO THE EXTENDED FOR NEXT WEEKEND - ECWMF AND GFS
BOTH SHOW A DEEPENING MID/UPPER CLOSED LOW MOVING FROM THE GREAT
LAKE TO NEW ENGLAND. THE 12.12Z ECMWF AMPLIFIED THE TROUGH,
SENDING A STRONG COLD FRONT ACROSS SOUTH FL WITH DEWPOINTS FALLING
INTO THE 40S AND 50S! HOWEVER, THE LATEST ECMWF RUN IS NOT AS
STRONG AND THE LATEST GFS RUN IS NOT AS AGGRESSIVE WITH THE
TROUGH, BRINGING A COLD FRONT THROUGH BRIEFLY NEXT WEEKEND WITH A
QUICK TURN OF THE WINDS TO THE NORTHEAST, KEEPING CONDITIONS WARM
AND RATHER HUMID. NO SIGNIFICANT WEATHER IS EXPECTED THROUGH THE
PERIOD.
MARINE...OBS SHOW SUSTAINED WINDS NEAR 20 KT ACROSS THE WATERS.
WILL CONTINUE THE SMALL CRAFT ADVISORY FOR THE ATLANTIC, BISCAYNE
BAY AND THE LAKE...AND ADD THE OFFSHORE GULF WATERS AS WELL. WINDS
WILL STAY UP THROUGH TONIGHT THEN BEGIN TO GRADUALLY SUBSIDE SUN-
MON. SEAS WILL CONTINUE AT 7 FT OR HIGHER ACROSS THE ATLANTIC
THROUGH SUNDAY BEFORE GRADUALLY SUBSIDING.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN WELL
ABOVE CRITICAL LEVELS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 78 87 76 / 40 20 40 30
FORT LAUDERDALE 85 78 88 79 / 40 20 40 40
MIAMI 85 79 88 77 / 40 20 40 40
NAPLES 89 72 90 75 / 20 10 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH SUNDAY EVENING FOR COASTAL BROWARD-
COASTAL MIAMI DADE-COASTAL PALM BEACH.
AM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR BISCAYNE BAY-
LAKE OKEECHOBEE.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT SUNDAY FOR COASTAL WATERS
FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL
WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING
FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR GULF WATERS FROM
CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
954 PM EDT SUN OCT 14 2012
.UPDATE...
HAVE MADE SEVERAL MINOR TWEAKS TO GRIDS...MOSTLY TO UPDATE FOR
CURRENT TRENDS BUT ALSO TO TWEAK POPS/WX GRIDS. INITIALLY
DECREASED POPS ESPECIALLY ACROSS THE METRO AREA TO ACCOUNT FOR THE
MOVEMENT OF THE FRONT...THEN INCREASED POPS ACROSS THE NORTH AS
CONVECTION FILLS IN. SPC MESOANALYSIS BARELY BRINGS 100 J/KG
SBCAPE INTO THE AREA AND RAP FORECAST NOT REALLY ANY BETTER...SO
CONTINUED TREND OF LIMITING THUNDER WORDING TO SLIGHT CHANCE WHILE
KEEPING OVERALL POPS LIKELY TO CATEGORICAL. ADDED PATCHY FOG
WORDING AS WELL. WILL BE KEEPING AN EYE ON CONVECTION ALONG THE
FRONT AS CELLS HAVE SHOWN SIGNS OF ROTATION...BUT WITH THE LACK OF
INSTABILITY DO NOT EXPECT ENOUGH UPDRAFTS TO CAUSE CONCERN ACROSS
OUR AREA. UPDATED PRODUCTS WILL BE OUT SHORTLY.
TDP
&&
.PREV DISCUSSION... /ISSUED 745 PM EDT SUN OCT 14 2012/
PREV DISCUSSION... /ISSUED 346 PM EDT SUN OCT 14 2012/
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
VARIABLE CLOUDINESS PREVAILS AT THIS TIME WITH SCATTERED SHOWERS
AND ISOLATED TSTMS IN EAST CENTRAL GA DUE TO ATLANTIC MOISTURE
INTERACTING WITH THE DIURNAL HEATING. OTHERWISE...A LINE OF SHOWERS
AND A FEW TSTMS IN NORTH AL WAS WELL AHEAD OF THE COLD FRONT IN THE
MS RIVER VALLEY. STILL EXPECTING MEASURABLE RAIN OVER NORTHWEST GA
AFTER 800 PM IN ADVANCE OF THE APPROACHING COLD FRONT AND AFTER
MIDNIGHT IN THE ATLANTA AND ATHENS METRO AREAS. THE SHOWERS AND A FEW
TSTMS WILL DIMINISH BY SUNRISE OVER NORTH GA AND CONTINUE MOVING
THROUGH CENTRAL GA ON MONDAY MORNING ENDING BY AFTERNOON. A
SOUTHWEST FLOW ALOFT IN ADVANCE OF THE FRONT WILL ALLOW MODERATE
AMOUNTS OF GULF MOISTURE...PWS AROUND 1.6 INCHES...TO FLOW INTO THE
STATE WITH WEAK INSTABILITY...CAPES AROUND 1000 J/KG. CONSEQUENTLY
.EXPECTING NUMEROUS SHOWERS WITH A FEW TSTMS PRIOR TO AND WITH THE
FRONTAL PASSAGE. QPF AMOUNTS OF AROUND ONE HALF INCH CAN BE
ANTICIPATED. HIGH PRESSURE WILL BUILD OVER THE FORECAST AREA ON
MONDAY AFTERNOON WITH A BREEZY NORTHWEST FLOW. COLD AIR ADVECTION
WILL CAUSE MIN TEMPS TO BE AROUND 5 DEGREES BELOW NORMAL FOR MONDAY
NIGHT.
CONTINUED TO LEAN TOWARD THE MET MOS GUIDANCE MORE FOR WEATHER
ELEMENTS THROUGH THE FIRST 18 HOURS BASED ON TIMING OF CONVECTION.
USED A BLEND OF MET/MAV MOS GUIDANCE IN THE 18 TO 36 HOUR RANGE.
16
LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG STORY THROUGH THE LONG TERM CONTINUES TO BE THE COLD FRONT
ANTICIPATED TO PUSH THROUGH THE TENNESSEE VALLEY AND INTO
NORTHWEST GEORGIA EARLY THURSDAY. LATEST ECMWF MORE IN ALIGNMENT
WITH THE GFS WITH REGARDS TO INITIAL TIMING AND STRENGTH...THOUGH
IT CONTINUES TO BE MORE AGGRESSIVE WITH SECONDARY LOW DEVELOPING
OVER EASTERN GEORGIA AND THE CAROLINAS EARLY FRIDAY. THAT BEING
SAID...THE 12Z ECMWF DOES APPEAR LESS ENTHUSIASTIC WITH THE
IMPACTS TO OUR CWA THAN THE PREVIOUS RUNS. GIVEN THE HIGH
UNCERTAINTY THAT SURROUNDS THIS EVENT...HAVE ONLY MADE MINOR
CHANGES TO THE EXTENDED FORECAST. HAVE GONE AHEAD AND INCREASED
POPS FROM SLIGHT CHANCE TO CHANCE ACROSS EASTERN GEORGIA EARLY
FRIDAY DUE TO A SLIGHTLY BETTER MODEL CONSENSUS ON THE PRECIP
DURING THAT TIME. OTHERWISE...HAVE GENERALLY ONLY MADE CHANGES TO
TEMPERATURES AND DEWPOINTS...THOUGH FAIRLY MINOR. THE PREVIOUS
DISCUSSION IS INCLUDED BELOW FOR REFERENCE.
31
/ISSUED 419 AM EDT SUN OCT 14 2012/
IN WAKE OF FROPA SUNDAY NIGHT INTO MONDAY...HIGH PRESSURE WILL
BUILD INTO THE AREA AND ALLOW FOR DRY CONDITIONS INTO MIDWEEK. THE
MAIN FORECAST CONCERN FOR THE LONG TERM WILL BE FROM A SECOND COLD
FRONT PROGGED TO INFLUENCE THE FORECAST AREA ON THURSDAY INTO
FRIDAY. MODEL SOLUTIONS CONTINUE TO HAVE SIGNIFICANT DISCREPANCIES
ON THE TIMING AND PRECIP POTENTIAL WITH THIS FEATURE. THE LATEST
GFS STILL SUGGESTS A MOSTLY DRY PASSAGE COMPARED TO THE
ECMWF...WHICH CONTRASTINGLY DEVELOPS A SECONDARY LOW OVER THE
SOUTHEAST CONUS AND DRAWS IN A MUCH MORE EXPANSIVE MOISTURE FIELD.
THE GFS ALSO IS MUCH MORE PROGRESSIVE THAN THE ECMWF...PUSHING THE
FRONT THROUGH ON THURSDAY MORNING AND AFTERNOON INSTEAD OF THE
LATTER THURSDAY NIGHT INTO FRIDAY SOLUTION. WILL THEREFORE
CONTINUE TO GO WITH A GENERAL BLEND AND INCLUDE SLIGHT TO CHANCE
POPS THROUGH THE PERIOD AND HAVE ISOLATED THUNDER POTENTIAL DURING
THURSDAY INTO THURSDAY NIGHT.
BY NEXT WEEKEND...THE GFS HAS THE UPPER TROUGH EXITING THE
REGION...WHILE THE ECMWF LINGERS AN UPPER CLOSED LOW OVER THE GREAT
LAKES AND HAS THE MAJORITY OF HIGH RH VALUES NORTH OF GEORGIA. IF
THE CLOSED LOW SOLUTION PANS OUT THEN ANY LOBES OF VORTICITY
TRACKING ALONG THE TROUGH WOULD ENHANCE CLOUD COVERAGE OR PRECIP
POTENTIAL. DUE TO THIS LARGE VARIATION AMONG GUIDANCE...WILL GO WITH
A DRY FORECAST THROUGH THE WEEKEND AND WILL MAKE ADJUSTMENTS ONCE
CONFIDENCE INCREASES WITH WEIGHING IN ON MODEL CONSISTENCY OR
CONSENSUS.
GENERALLY STUCK A BIT WARMER THAN MEX GUIDANCE FOR TEMPS AS THE
ECMWF HAS A WARMER SOLUTION THROUGH THE MAJORITY OF THE LONG TERM.
BAKER
AVIATION...
00Z UPDATE...
COLD FRONT APPROACHING FROM THE NW WILL PUSH INTO N GA LATER
TONIGHT. EXPECT SHRA WITH MVFR VSBY FROM A PERIOD AROUND 06-10Z
FOR NORTHERN TAFS...NOT CONFIDENT ENOUGH TO INCLUDE PREVAILING WX
AT CSG/MCN. TSRA STILL A POSSIBILITY BUT WITH ONLY SLIGHT CHANCE
HAVE LEFT IT OUT OF TAF AT THIS TIME. EXPECT CIGS TO DROP TO LOW
MVFR OR IFR EVERYWHERE...AND LIFR FROM APPROX 11-14Z AT MCN. SSE
WINDS THIS EVENING SHIFT TO SW NO LATER THAN 06Z...AND THEN TO NW
BY MONDAY AFTERNOON 10-15KT WITH GUSTS 20-25KT...HIGHER AT ATL.
CLEARING MONDAY LATE AFTERNOON.
//ATL CONFIDENCE...00Z UPDATE...
HIGH ON SHRA OVERNIGHT...LOW ON POSSIBILITY OF TSRA.
MEDIUM ON TIMING OF WIND SHIFT BACK TO SW AT 06Z.
HIGH ON CIGS OVERNIGHT...MEDIUM ON TIMING OF DEVELOPMENT AND
IMPROVEMENT.
HIGH ON WINDS MONDAY.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 62 76 46 74 / 40 50 0 5
ATLANTA 62 74 49 72 / 60 30 0 5
BLAIRSVILLE 54 67 41 69 / 100 20 0 5
CARTERSVILLE 59 73 42 73 / 80 20 0 5
COLUMBUS 65 80 50 76 / 40 40 0 5
GAINESVILLE 60 74 47 70 / 70 30 0 5
MACON 63 82 47 78 / 30 40 0 5
ROME 58 73 42 74 / 90 10 0 5
PEACHTREE CITY 61 77 42 75 / 50 30 0 5
VIDALIA 65 83 54 79 / 20 20 0 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
128 AM EDT SAT OCT 13 2012
.SYNOPSIS...
STRONG HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE NORTH
THROUGH THIS WEEKEND. A WEAK COLD FRONT WILL MOVE ACROSS THE
AREA EARLY NEXT WEEK...FOLLOWED BY WEAK HIGH PRESSURE THROUGH
MID WEEK. A COLD FRONT IS EXPECTED TO APPROACH THE EAST COAST
LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
BAND OF HIGH CLOUDS EXTENDING FROM TENNESSEE INTO SOUTHERN SOUTH
CAROLINA CORRELATE WELL WITH THE LATEST RAP 300MB MOISTURE FIELDS.
RAP SHOWS THE CIRRUS STEADILY THINNING WITH TIME AND CURRENT GOES-
EAST IR CHANNELS SUGGEST THIS IS ALREADY IN PROGRESS. MADE SOME
ADJUSTMENTS TO SKY COVER TO TAKE CURRENT TRENDS INTO ACCOUNT. ALSO
INCREASED WINDS ACROSS THE COASTAL AREAS AS WINDS ARE EXPECTED TO
INCREASE RATHER RAPIDLY OVER THE NEXT FEW HOURS AS THE PRESSURE
GRADIENT TIGHTENS. TEMPERATURES LOOK ON TRACK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
HIGH PRESSURE WILL RIDGE DOWN THE EAST COAST THROUGH THE PERIOD. A
COLD FRONT WILL APPROACH FROM THE WEST SUNDAY NIGHT. THE NET RESULT
OF THESE FEATURES WILL BE FAIR WEATHER THROUGH THE PERIOD...THOUGH
THERE MAY BE AN INCREASE IN CLOUDINESS AHEAD OF THE FRONT SUNDAY
NIGHT. THERE IS ALSO AN OUTSIDE SHOT AT A SHOWER OR THUNDERSTORM
LATE BUT THE PROBABILITY OF THAT IS LOW ENOUGH THAT IT WILL NOT BE
INCLUDED IN THE FORECAST AT THIS TIME. MAX TEMPERATURES SATURDAY
WILL GENERALLY FALL BETWEEN 75 AND 80 AND BE TWO OR THREE DEGREES
WARMER SUNDAY. MINS SATURDAY NIGHT WILL MAINLY BE IN THE LOWER TO
MIDDLE 50S. AND MODERATE TO THE UPPER 50S TO MIDDLE 60S SUNDAY
NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE COLD FRONT WILL RAPIDLY SHIFT OFFSHORE MONDAY AND MONDAY
NIGHT...WITH WEAK HIGH PRESSURE BUILDING IN ITS WAKE TUESDAY THROUGH
WEDNESDAY. WILL KEEP RAIN CHANCES BELOW 15 PERCENT OVER LAND AREAS
TUESDAY AND WEDNESDAY ACCORDINGLY. ANOTHER COLD FRONT IS THEN
EXPECTED TO APPROACH FROM THE WEST ON THURSDAY...AND COULD
RE-INTRODUCE RAIN CHANCES FOR THE LATE WEEK PERIOD. OVERALL...HIGH
TEMPERATURES WILL GENERALLY RANGE FROM THE UPPER 70S NORTHERN AREAS
TO THE LOW 80S SOUTH. OVERNIGHT LOWS TREND SLIGHTLY WARMER TO THE
UPPER 50S INLAND AND THE LOW/MID 60S ALONG THE COAST.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR. GUSTY WINDS WILL IMPACT THE TERMINALS AFTER SUNRISE IN
RESPONSE TO A TIGHTENING PRESSURE GRADIENT. THERE ARE SMALL
PROBABILITIES FOR MARGINAL MVFR CIGS TONIGHT AT KSAV...BUT
PROBABILITIES ARE TOO LOW TO JUSTIFY A MENTION ATTM.
EXTENDED AVIATION OUTLOOK...BREEZY/GUSTY NORTHEAST/EAST WINDS ARE
EXPECTED SATURDAY WITH A STRONG WEDGE OF HIGH PRESSURE IN PLACE.
THERE WILL BE AN INCREASING RISK FOR SHOWERS AND MVFR CIGS/VSBYS
EARLY NEXT WEEK...AS LOW-LEVEL MOISTURE INCREASES AND A WEAK COLD
FRONT AFFECTS THE AREA.
&&
.MARINE...
STRONG NORTHEAST SURGE IS BEGINNING TO TAKE SHAPE ALONG THE NORTH
CAROLINA COAST WHERE WINDS ARE ALREADY 20-25 KT WITH GUSTS TO 30
KT. RAP/H3R AS WELL AS THE LATEST MARINE TABULAR GUIDANCE ALL
SUPPORT WINDS INCREASING TO 20-25 KT WITH GUSTS TO 30 KT ACROSS
THE SOUTH CAROLINA MARINE ZONES OVER THE NEXT FEW HOURS AS THE
PRESSURE GRADIENT TIGHTENS IN RESPONSE TO HIGH PRESSURE WEDGING
DOWN THE CAROLINA PIEDMONT. THE STRONGEST SURGE WILL LIKELY WAIT
UNTIL AFTER SUNRISE TO REACH THE GEORGIA MARINE ZONES. SEAS WILL
BUILD QUICKLY IN THE NORTHEAST FLOW REGIME...LIKELY REACHING 4-6
FT OFF THE SOUTH CAROLINA COAST BY SUNRISE. SMALL CRAFT ADVISORIES
REMAIN IN FORCE FOR ALL MARINE LEGS.
SATURDAY THROUGH TUESDAY...STRONG HIGH PRESSURE WILL BUILD NORTH
OF THE AREA SATURDAY...BEFORE WEAKENING AND SHIFTING OFFSHORE
SUNDAY. A WEAK COASTAL TROUGH OF LOW PRESSURE COULD SET UP SUNDAY
BEFORE A COLD FRONT PUSHES THROUGH THE WATERS MONDAY INTO TUESDAY.
WILL CONTINUE THE ONGOING SMALL CRAFT ADVISORIES FOR ALL WATERS TO
ACCOUNT FOR MODERATE TO STRONG NORTHEAST FLOW AND BUILDING SEAS.
CONDITIONS ARE EXPECTED TO DIMINISH BY LATE SATURDAY FOR THE
NEARSHORE WATERS...HOWEVER LINGERING 6 FT SEAS WITHIN AN IDEAL FETCH
WILL MAINTAIN A SMALL CRAFT ADVISORY FOR THE OUTER GEORGIA WATERS
THROUGH AT LEAST MONDAY.
RIP CURRENTS...STRONG NE WINDS AND THE APPROACHING PERIGEAN SPRING
TIDE WILL CONTRIBUTE TO A MODERATE RISK FOR RIP CURRENTS ON ALL
BEACHES SATURDAY.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE ELEVATED THIS WEEKEND INTO THE MIDDLE OF NEXT
WEEK MAINLY DUE TO THE PERIGEAN SPRING TIDE. THERE IS A GOOD
CHANCE THAT TIDES WILL BE HIGH ENOUGH TO PRODUCE SOME INUNDATION
OF SALTWATER IN NORMALLY PRONE AREAS STARTING SUNDAY MORNING.
COASTAL FLOOD ADVISORIES WILL LIKELY BE NEEDED AT LEAST AROUND THE
TIMES OF THE MORNING HIGH TIDE EACH DAY THROUGH THE MIDDLE OF NEXT
WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR AMZ330-350-
352-354.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT MONDAY NIGHT FOR
AMZ374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1212 AM EDT SAT OCT 13 2012
.SYNOPSIS...
STRONG HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE NORTH
THROUGH THIS WEEKEND. A WEAK COLD FRONT WILL MOVE ACROSS THE
AREA EARLY NEXT WEEK...FOLLOWED BY WEAK HIGH PRESSURE THROUGH
MID WEEK. A COLD FRONT IS EXPECTED TO APPROACH THE EAST COAST
LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
BAND OF HIGH CLOUDS EXTENDING FROM TENNESSEE INTO SOUTHERN SOUTH
CAROLINA CORRELATE WELL WITH THE LATEST RAP 300MB MOISTURE FIELDS.
RAP SHOWS THE CIRRUS STEADILY THINNING WITH TIME AND CURRENT GOES-
EAST IR CHANNELS SUGGEST THIS IS ALREADY IN PROGRESS. MADE SOME
ADJUSTMENTS TO SKY COVER TO TAKE CURRENT TRENDS INTO ACCOUNT. ALSO
INCREASED WINDS ACROSS THE COASTAL AREAS AS WINDS ARE EXPECTED TO
INCREASE RATHER RAPIDLY OVER THE NEXT FEW HOURS AS THE PRESSURE
GRADIENT TIGHTENS. TEMPERATURES LOOK ON TRACK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
HIGH PRESSURE WILL RIDGE DOWN THE EAST COAST THROUGH THE PERIOD. A
COLD FRONT WILL APPROACH FROM THE WEST SUNDAY NIGHT. THE NET RESULT
OF THESE FEATURES WILL BE FAIR WEATHER THROUGH THE PERIOD...THOUGH
THERE MAY BE AN INCREASE IN CLOUDINESS AHEAD OF THE FRONT SUNDAY
NIGHT. THERE IS ALSO AN OUTSIDE SHOT AT A SHOWER OR THUNDERSTORM
LATE BUT THE PROBABILITY OF THAT IS LOW ENOUGH THAT IT WILL NOT BE
INCLUDED IN THE FORECAST AT THIS TIME. MAX TEMPERATURES SATURDAY
WILL GENERALLY FALL BETWEEN 75 AND 80 AND BE TWO OR THREE DEGREES
WARMER SUNDAY. MINS SATURDAY NIGHT WILL MAINLY BE IN THE LOWER TO
MIDDLE 50S. AND MODERATE TO THE UPPER 50S TO MIDDLE 60S SUNDAY
NIGHT.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE COLD FRONT WILL RAPIDLY SHIFT OFFSHORE MONDAY AND MONDAY
NIGHT...WITH WEAK HIGH PRESSURE BUILDING IN ITS WAKE TUESDAY THROUGH
WEDNESDAY. WILL KEEP RAIN CHANCES BELOW 15 PERCENT OVER LAND AREAS
TUESDAY AND WEDNESDAY ACCORDINGLY. ANOTHER COLD FRONT IS THEN
EXPECTED TO APPROACH FROM THE WEST ON THURSDAY...AND COULD
RE-INTRODUCE RAIN CHANCES FOR THE LATE WEEK PERIOD. OVERALL...HIGH
TEMPERATURES WILL GENERALLY RANGE FROM THE UPPER 70S NORTHERN AREAS
TO THE LOW 80S SOUTH. OVERNIGHT LOWS TREND SLIGHTLY WARMER TO THE
UPPER 50S INLAND AND THE LOW/MID 60S ALONG THE COAST.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
VFR LIKELY THROUGH SATURDAY. HOWEVER...LOW LEVEL MOISTURE DEPICTED
BY MODEL SOUNDINGS SUGGESTS SOME POTENTIAL FOR OCCASIONAL MVFR
CEILINGS SATURDAY. STRONG HIGH PRESSURE CENTERED N/NE OF THE
TERMINALS WILL SUPPORT E/NE WINDS WITH GUSTS AROUND 20 KT
SATURDAY.
EXTENDED AVIATION OUTLOOK...BREEZY/GUSTY NORTHEAST/EAST WINDS ARE
EXPECTED SATURDAY WITH A STRONG WEDGE OF HIGH PRESSURE IN PLACE.
THERE WILL BE AN INCREASING RISK FOR SHOWERS AND MVFR CIGS/VSBYS
EARLY NEXT WEEK...AS LOW-LEVEL MOISTURE INCREASES AND A WEAK COLD
FRONT AFFECTS THE AREA.
&&
.MARINE...
STRONG NORTHEAST SURGE IS BEGINNING TO TAKE SHAPE ALONG THE NORTH
CAROLINA COAST WHERE WINDS ARE ALREADY 20-25 KT WITH GUSTS TO 30
KT. RAP/H3R AS WELL AS THE LATEST MARINE TABULAR GUIDANCE ALL
SUPPORT WINDS INCREASING TO 20-25 KT WITH GUSTS TO 30 KT ACROSS
THE SOUTH CAROLINA MARINE ZONES OVER THE NEXT FEW HOURS AS THE
PRESSURE GRADIENT TIGHTENS IN RESPONSE TO HIGH PRESSURE WEDGING
DOWN THE CAROLINA PIEDMONT. THE STRONGEST SURGE WILL LIKELY WAIT
UNTIL AFTER SUNRISE TO REACH THE GEORGIA MARINE ZONES. SEAS WILL
BUILD QUICKLY IN THE NORTHEAST FLOW REGIME...LIKELY REACHING 4-6
FT OFF THE SOUTH CAROLINA COAST BY SUNRISE. SMALL CRAFT ADVISORIES
REMAIN IN FORCE FOR ALL MARINE LEGS.
SATURDAY THROUGH TUESDAY...STRONG HIGH PRESSURE WILL BUILD NORTH
OF THE AREA SATURDAY...BEFORE WEAKENING AND SHIFTING OFFSHORE
SUNDAY. A WEAK COASTAL TROUGH OF LOW PRESSURE COULD SET UP SUNDAY
BEFORE A COLD FRONT PUSHES THROUGH THE WATERS MONDAY INTO TUESDAY.
WILL CONTINUE THE ONGOING SMALL CRAFT ADVISORIES FOR ALL WATERS TO
ACCOUNT FOR MODERATE TO STRONG NORTHEAST FLOW AND BUILDING SEAS.
CONDITIONS ARE EXPECTED TO DIMINISH BY LATE SATURDAY FOR THE
NEARSHORE WATERS...HOWEVER LINGERING 6 FT SEAS WITHIN AN IDEAL FETCH
WILL MAINTAIN A SMALL CRAFT ADVISORY FOR THE OUTER GEORGIA WATERS
THROUGH AT LEAST MONDAY.
RIP CURRENTS...STRONG NE WINDS AND THE APPROACHING PERIGEAN SPRING
TIDE WILL CONTRIBUTE TO A MODERATE RISK FOR RIP CURRENTS ON ALL
BEACHES SATURDAY.
&&
.TIDES/COASTAL FLOODING...
TIDE LEVELS WILL BE ELEVATED THIS WEEKEND INTO THE MIDDLE OF NEXT
WEEK MAINLY DUE TO THE PERIGEAN SPRING TIDE. THERE IS A GOOD
CHANCE THAT TIDES WILL BE HIGH ENOUGH TO PRODUCE SOME INUNDATION
OF SALTWATER IN NORMALLY PRONE AREAS STARTING SUNDAY MORNING.
COASTAL FLOOD ADVISORIES WILL LIKELY BE NEEDED AT LEAST AROUND THE
TIMES OF THE MORNING HIGH TIDE EACH DAY THROUGH THE MIDDLE OF NEXT
WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR AMZ330-350-
352-354.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT MONDAY NIGHT FOR
AMZ374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1235 PM CDT SAT OCT 13 2012
.DISCUSSION...
ISSUED 1030 AM CDT SAT OCT 13 2012
ELEVATED SHOWERS AND THUNDERSTORMS WERE WIDESPREAD ACROSS THE
NORTHERN HALF OF ILLINOIS AT 10 AM. WILL CONTINUE TO SEE THAT
SPREAD EASTWARD THE REMAINDER OF THE MORNING...BEFORE A BREAK IN
THE RAIN OCCURS EARLY THIS AFTERNOON. MAIN QUESTION WILL BE HOW
MUCH RENEWED INSTABILITY CAN DEVELOP THIS AFTERNOON. TEMPERATURES
CURRENTLY ONLY IN THE 50S OVER ALMOST ALL THE CWA EXCEPT THE
EXTREME SOUTHEAST. LOW CLOUDS WERE EXTENSIVE WESTWARD ALL THE WAY
INTO KANSAS...ALTHOUGH RECENT VISIBLE SATELLITE IMAGERY SHOWING
SOME SIZABLE BREAKS DEVELOPING IN CENTRAL MISSOURI. LATEST RAP...
HRRR AND NAM SHOWING SHOWERS AND STORMS CURRENTLY IN NORTHWEST
MISSOURI AND EASTERN KANSAS ADVECTING NORTHEAST...WITH SOME
ADDITIONAL REDEVELOPING OVER NORTHERN MISSOURI THIS AFTERNOON
BEFORE MOVING INTO ILLINOIS.
UPDATED ZONES/GRIDS WERE SENT ABOUT A HALF HOUR AGO TO ADDRESS THE
LATEST RAIN AND TEMPERATURE TRENDS. WILL NEED TO MONITOR
TEMPERATURES CLOSELY...AS THE RAIN AND EXTENSIVE CLOUD COVER WILL
LIKELY PREVENT ANY RAPID WARM UPS. TEMPERATURES WERE LOWERED BY A
FEW DEGREES IN THE RECENT UPDATE.
GEELHART
&&
.AVIATION...
ISSUED 1235 PM CDT SAT OCT 13 2012
COMPLICATED TAF FORECAST FOR THIS PERIOD. WIDESPREAD MVFR/IFR
CONDITIONS OVER THE TAF SITES AT MIDDAY...WESTWARD ACROSS
MISSOURI...ALTHOUGH SURFACE OBS AND SATELLITE SHOWING SOME
THINNING CLOUDS AND VFR CEILINGS WEST OF KSPI. FORECAST SOUNDINGS
TRYING TO SHOW SOME GRADUAL IMPROVEMENT BY MID TO LATE
AFTERNOON...BUT INVERSION AROUND 2000 FEET MAY BE DIFFICULT TO
OVERCOME IN SOME AREAS. WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS CONTINUE TO PUSH THROUGH THE AREA...BUT A COUPLE
HOUR BREAK AROUND KPIA/KSPI IS LIKELY BETWEEN THE INITIAL BLOB
OF RAIN AND A LINE OF RAIN EXPANDING FROM SOUTHWEST MISSOURI INTO
EASTERN IOWA. AT THE EASTERN TAF SITES...A MORE EXTENDED BREAK IS
EXPECTED THIS EVENING...WITH RETURN OF RAIN AND MVFR CEILINGS
DEVELOPING AFTER 06Z.
AS STRENGTHENING LOW PRESSURE MOVES ACROSS NORTHWEST ILLINOIS ON
SUNDAY MORNING...SOUTHWEST WINDS WILL RAMP UP...AND GUSTS SHOULD
BE APPROACHING 25-30 KNOTS BY LATE MORNING. LINGERING
SHOWERS/STORMS SHOULD DIMINISH TO SCATTERED ACTIVITY AS A DRY SLOT
STARTS TO WRAP AROUND THE LOW.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 327 AM CDT SAT OCT 13 2012
SHORT TERM...TODAY THROUGH SUNDAY
MAIN CONCERNS THIS FORECAST PERIOD WILL BE ANTICIPATED CONVECTION
AND ANY ASSOCIATED STRONG/SEVERE STORMS AND HEAVY RAINFALL.
ELEVATED CONVECTION WAS ONGOING IN NORTHERN IL...AS WELL AS
NORTHERN AND CENTRAL MO. THIS WAS ASSOCIATED WITH LOWER LEVEL WARM
AIR ADVECTION/ISENTROPIC LIFT. THE GFS 300K SURFACE INDICATED THAT
THIS WILL CONTINUE THROUGH MUCH OF THE MORNING IN NORTHERN AND
CENTRAL IL. THE HRRR MODEL CONCURS THAT PERIODS OF SHOWERS AND
T-STORMS CAN BE EXPECTED THIS MORNING... ESPECIALLY ALONG AND
NORTH OF A TAYLORVILLE- DANVILLE LINE.
HIGH TEMPERATURES...AND PARTICULARLY SFC BASED INSTABILITY...WILL BE
CHALLENGING BECAUSE OF CONVECTIVE DEBRIS AS WELL AS PLENTY OF LOW
LEVEL MOISTURE AND AN INVERSION ON FORECAST SOUNDINGS UNTIL LATE
THIS AFTERNOON IN CENTRAL IL. WILL KNOCK DOWN HIGH TEMPS IN CENTRAL
IL AS A RESULT...BUT KEEP WARMER READINGS IN THE SOUTHEAST.
DESPITE MARGINAL INSTABILITY IN MOST AREAS THIS EVENING...INCREASING
UPPER LEVEL DIVERGENCE AHEAD OF AN UPPER LOW IN NORTHEAST KS ALONG
WITH 30-40KTS OF BULK SHEAR WILL RESULT IN A DEVELOPING LINE OF
STORMS APPROACHING WEST CENTRAL IL LATE THIS EVENING.
UNIDIRECTIONAL FLOW ALOFT AND INCREASING LOW LEVEL WINDS BELOW
850 MB COULD RESULT IN GUSTY WINDS WITH THE STRONGEST STORMS.
WITH EACH SUCCESSIVE MODEL RUN A BIT SLOWER...AM NOT EXPECTING THE
T-STORMS TO REACH EXTREME EAST AND SOUTHEAST IL UNTIL VERY LATE
TONIGHT. EXPECT SHOWERS AND ISOLATED T-STORMS TO LINGER IN
CENTRAL IL MUCH OF THE DAY SUNDAY AHEAD OF THE UPPER LEVEL TROUGH
AXIS...BEFORE DEPARTING THE STATE LATE SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH FRIDAY
A SEMI-ZONAL FLOW WILL DEVELOP AFTER THE UPPER LEVEL TROF
DEAMPLIFIES AND LIFTS THROUGH THE NEW ENGLAND STATES LATER MONDAY
AND TUESDAY. THIS WILL RESULT IN TEMPERATURES CLOSE TO SEASONAL
NORMALS FOR MID-OCTOBER.
THE NEXT CHANCE FOR PRECIPITATION IS EXPECTED LATE TUESDAY
NIGHT...BUT PARTICULARLY WEDNESDAY AS AN UPPER LEVEL TROUGH FROM
THE PACIFIC NORTHWEST CROSSES INTO THE NORTHERN PLAINS AND DEEPENS
IN THE UPPER MIDWEST. THERE IS CONSIDERABLE MODEL UNCERTAINTY AT
THIS POINT WITH THE SPEED OF THE SYSTEM AND JUST HOW FAR SOUTH THE
UPPER LEVEL LOW WILL DEVELOP AND HOW STRONG IT WILL BE. FOR NOW
WILL GO WITH SHOWERS AND A FEW T-STORMS AHEAD OF THE SURFACE COLD
FRONT WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY SOMEWHAT COOLER
TEMPERATURES IN THE LOWER TO MIDDLE 60S.
WILL NEED TO KEEP AN EYE ON THIS SYSTEM BECAUSE IF THE UPPER LOW
SETTLES OVER THE MIDWEST THEN TEMPERATURES WILL BE QUITE CHILLY
WITH RAINY CONDITIONS FOR FRIDAY AND BEYOND.
MILLER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1032 AM CDT SAT OCT 13 2012
.DISCUSSION...
ISSUED 1030 AM CDT SAT OCT 13 2012
ELEVATED SHOWERS AND THUNDERSTORMS WERE WIDESPREAD ACROSS THE
NORTHERN HALF OF ILLINOIS AT 10 AM. WILL CONTINUE TO SEE THAT
SPREAD EASTWARD THE REMAINDER OF THE MORNING...BEFORE A BREAK IN
THE RAIN OCCURS EARLY THIS AFTERNOON. MAIN QUESTION WILL BE HOW
MUCH RENEWED INSTABILITY CAN DEVELOP THIS AFTERNOON. TEMPERATURES
CURRENTLY ONLY IN THE 50S OVER ALMOST ALL THE CWA EXCEPT THE
EXTREME SOUTHEAST. LOW CLOUDS WERE EXTENSIVE WESTWARD ALL THE WAY
INTO KANSAS...ALTHOUGH RECENT VISIBLE SATELLITE IMAGERY SHOWING
SOME SIZABLE BREAKS DEVELOPING IN CENTRAL MISSOURI. LATEST RAP...
HRRR AND NAM SHOWING SHOWERS AND STORMS CURRENTLY IN NORTHWEST
MISSOURI AND EASTERN KANSAS ADVECTING NORTHEAST...WITH SOME
ADDITIONAL REDEVELOPING OVER NORTHERN MISSOURI THIS AFTERNOON
BEFORE MOVING INTO ILLINOIS.
UPDATED ZONES/GRIDS WERE SENT ABOUT A HALF HOUR AGO TO ADDRESS THE
LATEST RAIN AND TEMPERATURE TRENDS. WILL NEED TO MONITOR
TEMPERATURES CLOSELY...AS THE RAIN AND EXTENSIVE CLOUD COVER WILL
LIKELY PREVENT ANY RAPID WARM UPS. TEMPERATURES WERE LOWERED BY A
FEW DEGREES IN THE RECENT UPDATE.
GEELHART
&&
.AVIATION...
ISSUED 658 AM CDT SAT OCT 13 2012
PERIODS OF SHOWERS AND THUNDERSTORMS WILL IMPACT THE CENTRAL
ILLINOIS TERMINALS THROUGH THE 12Z TAF VALID TIME AS A SLOW MOVING
STORM SYSTEM MOVES THROUGH THE AREA. THE FIRST WAVE SHOULD MOVE
THROUGH MAINLY KPIA/KBMI/KSPI IN THE NEXT FEW HOURS...WITH
KDEC/KCMI MISSING OUT FOR NOW. A PERIOD OF MVFR CIGS WILL DEVELOP
SHORTLY AND LAST INTO THE AFTERNOON UNTIL DIURNAL MIXING AND THE
PASSAGE OF A WARM FRONT LIFT THEM BACK TO VFR. EXPECT
PRECIPITATION COVERAGE TO BECOME MORE WIDESPREAD TONIGHT AHEAD OF
AN ADVANCING COLD FRONT...BUT LIMITED THUNDER MENTION TO VCTS UNTIL
COVERAGE IS BETTER DEFINED. CIGS SHOULD GRADUALLY DROP BACK TO
MVFR AS PRECIP EXPANDS TONIGHT. GUSTY SOUTHERLY WINDS ARE EXPECTED
TODAY...ESPECIALLY TOWARD MIDDAY IN THE WAKE OF THE WARM FRONT.
EXPECT THE GUSTS TO DROP OFF TONIGHT AWAY FROM ANY STORMS...BUT
THEY SHOULD HOLD ABOVE 10 KTS.
BAK
&&
.PREV DISCUSSION...
ISSUED 327 AM CDT SAT OCT 13 2012
SHORT TERM...TODAY THROUGH SUNDAY
MAIN CONCERNS THIS FORECAST PERIOD WILL BE ANTICIPATED CONVECTION
AND ANY ASSOCIATED STRONG/SEVERE STORMS AND HEAVY RAINFALL.
ELEVATED CONVECTION WAS ONGOING IN NORTHERN IL...AS WELL AS
NORTHERN AND CENTRAL MO. THIS WAS ASSOCIATED WITH LOWER LEVEL WARM
AIR ADVECTION/ISENTROPIC LIFT. THE GFS 300K SURFACE INDICATED THAT
THIS WILL CONTINUE THROUGH MUCH OF THE MORNING IN NORTHERN AND
CENTRAL IL. THE HRRR MODEL CONCURS THAT PERIODS OF SHOWERS AND
T-STORMS CAN BE EXPECTED THIS MORNING... ESPECIALLY ALONG AND
NORTH OF A TAYLORVILLE- DANVILLE LINE.
HIGH TEMPERATURES...AND PARTICULARLY SFC BASED INSTABILITY...WILL BE
CHALLENGING BECAUSE OF CONVECTIVE DEBRIS AS WELL AS PLENTY OF LOW
LEVEL MOISTURE AND AN INVERSION ON FORECAST SOUNDINGS UNTIL LATE
THIS AFTERNOON IN CENTRAL IL. WILL KNOCK DOWN HIGH TEMPS IN CENTRAL
IL AS A RESULT...BUT KEEP WARMER READINGS IN THE SOUTHEAST.
DESPITE MARGINAL INSTABILITY IN MOST AREAS THIS EVENING...INCREASING
UPPER LEVEL DIVERGENCE AHEAD OF AN UPPER LOW IN NORTHEAST KS ALONG
WITH 30-40KTS OF BULK SHEAR WILL RESULT IN A DEVELOPING LINE OF
STORMS APPROACHING WEST CENTRAL IL LATE THIS EVENING.
UNIDIRECTIONAL FLOW ALOFT AND INCREASING LOW LEVEL WINDS BELOW
850 MB COULD RESULT IN GUSTY WINDS WITH THE STRONGEST STORMS.
WITH EACH SUCCESSIVE MODEL RUN A BIT SLOWER...AM NOT EXPECTING THE
T-STORMS TO REACH EXTREME EAST AND SOUTHEAST IL UNTIL VERY LATE
TONIGHT. EXPECT SHOWERS AND ISOLATED T-STORMS TO LINGER IN
CENTRAL IL MUCH OF THE DAY SUNDAY AHEAD OF THE UPPER LEVEL TROUGH
AXIS...BEFORE DEPARTING THE STATE LATE SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH FRIDAY
A SEMI-ZONAL FLOW WILL DEVELOP AFTER THE UPPER LEVEL TROF
DEAMPLIFIES AND LIFTS THROUGH THE NEW ENGLAND STATES LATER MONDAY
AND TUESDAY. THIS WILL RESULT IN TEMPERATURES CLOSE TO SEASONAL
NORMALS FOR MID-OCTOBER.
THE NEXT CHANCE FOR PRECIPITATION IS EXPECTED LATE TUESDAY
NIGHT...BUT PARTICULARLY WEDNESDAY AS AN UPPER LEVEL TROUGH FROM
THE PACIFIC NORTHWEST CROSSES INTO THE NORTHERN PLAINS AND DEEPENS
IN THE UPPER MIDWEST. THERE IS CONSIDERABLE MODEL UNCERTAINTY AT
THIS POINT WITH THE SPEED OF THE SYSTEM AND JUST HOW FAR SOUTH THE
UPPER LEVEL LOW WILL DEVELOP AND HOW STRONG IT WILL BE. FOR NOW
WILL GO WITH SHOWERS AND A FEW T-STORMS AHEAD OF THE SURFACE COLD
FRONT WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY SOMEWHAT COOLER
TEMPERATURES IN THE LOWER TO MIDDLE 60S.
WILL NEED TO KEEP AN EYE ON THIS SYSTEM BECAUSE IF THE UPPER LOW
SETTLES OVER THE MIDWEST THEN TEMPERATURES WILL BE QUITE CHILLY
WITH RAINY CONDITIONS FOR FRIDAY AND BEYOND.
MILLER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
658 AM CDT SAT OCT 13 2012
.DISCUSSION...
ISSUED 327 AM CDT SAT OCT 13 2012
SHORT TERM...TODAY THROUGH SUNDAY
MAIN CONCERNS THIS FORECAST PERIOD WILL BE ANTICIPATED CONVECTION
AND ANY ASSOCIATED STRONG/SEVERE STORMS AND HEAVY RAINFALL.
ELEVATED CONVECTION WAS ONGOING IN NORTHERN IL...AS WELL AS
NORTHERN AND CENTRAL MO. THIS WAS ASSOCIATED WITH LOWER LEVEL WARM
AIR ADVECTION/ISENTROPIC LIFT. THE GFS 300K SURFACE INDICATED THAT
THIS WILL CONTINUE THROUGH MUCH OF THE MORNING IN NORTHERN AND
CENTRAL IL. THE HRRR MODEL CONCURS THAT PERIODS OF SHOWERS AND
T-STORMS CAN BE EXPECTED THIS MORNING... ESPECIALLY ALONG AND
NORTH OF A TAYLORVILLE- DANVILLE LINE.
HIGH TEMPERATURES...AND PARTICULARLY SFC BASED INSTABILITY...WILL BE
CHALLENGING BECAUSE OF CONVECTIVE DEBRIS AS WELL AS PLENTY OF LOW
LEVEL MOISTURE AND AN INVERSION ON FORECAST SOUNDINGS UNTIL LATE
THIS AFTERNOON IN CENTRAL IL. WILL KNOCK DOWN HIGH TEMPS IN CENTRAL
IL AS A RESULT...BUT KEEP WARMER READINGS IN THE SOUTHEAST.
DESPITE MARGINAL INSTABILITY IN MOST AREAS THIS EVENING...INCREASING
UPPER LEVEL DIVERGENCE AHEAD OF AN UPPER LOW IN NORTHEAST KS ALONG
WITH 30-40KTS OF BULK SHEAR WILL RESULT IN A DEVELOPING LINE OF
STORMS APPROACHING WEST CENTRAL IL LATE THIS EVENING.
UNIDIRECTIONAL FLOW ALOFT AND INCREASING LOW LEVEL WINDS BELOW
850 MB COULD RESULT IN GUSTY WINDS WITH THE STRONGEST STORMS.
WITH EACH SUCCESSIVE MODEL RUN A BIT SLOWER...AM NOT EXPECTING THE
T-STORMS TO REACH EXTREME EAST AND SOUTHEAST IL UNTIL VERY LATE
TONIGHT. EXPECT SHOWERS AND ISOLATED T-STORMS TO LINGER IN
CENTRAL IL MUCH OF THE DAY SUNDAY AHEAD OF THE UPPER LEVEL TROUGH
AXIS...BEFORE DEPARTING THE STATE LATE SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH FRIDAY
A SEMI-ZONAL FLOW WILL DEVELOP AFTER THE UPPER LEVEL TROF
DEAMPLIFIES AND LIFTS THROUGH THE NEW ENGLAND STATES LATER MONDAY
AND TUESDAY. THIS WILL RESULT IN TEMPERATURES CLOSE TO SEASONAL
NORMALS FOR MID-OCTOBER.
THE NEXT CHANCE FOR PRECIPITATION IS EXPECTED LATE TUESDAY
NIGHT...BUT PARTICULARLY WEDNESDAY AS AN UPPER LEVEL TROUGH FROM
THE PACIFIC NORTHWEST CROSSES INTO THE NORTHERN PLAINS AND DEEPENS
IN THE UPPER MIDWEST. THERE IS CONSIDERABLE MODEL UNCERTAINTY AT
THIS POINT WITH THE SPEED OF THE SYSTEM AND JUST HOW FAR SOUTH THE
UPPER LEVEL LOW WILL DEVELOP AND HOW STRONG IT WILL BE. FOR NOW
WILL GO WITH SHOWERS AND A FEW T-STORMS AHEAD OF THE SURFACE COLD
FRONT WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY SOMEWHAT COOLER
TEMPERATURES IN THE LOWER TO MIDDLE 60S.
WILL NEED TO KEEP AN EYE ON THIS SYSTEM BECAUSE IF THE UPPER LOW
SETTLES OVER THE MIDWEST THEN TEMPERATURES WILL BE QUITE CHILLY
WITH RAINY CONDITIONS FOR FRIDAY AND BEYOND.
MILLER
&&
.AVIATION...
ISSUED 658 AM CDT SAT OCT 13 2012
PERIODS OF SHOWERS AND THUNDERSTORMS WILL IMPACT THE CENTRAL
ILLINOIS TERMINALS THROUGH THE 12Z TAF VALID TIME AS A SLOW MOVING
STORM SYSTEM MOVES THROUGH THE AREA. THE FIRST WAVE SHOULD MOVE
THROUGH MAINLY KPIA/KBMI/KSPI IN THE NEXT FEW HOURS...WITH
KDEC/KCMI MISSING OUT FOR NOW. A PERIOD OF MVFR CIGS WILL DEVELOP
SHORTLY AND LAST INTO THE AFTERNOON UNTIL DIURNAL MIXING AND THE
PASSAGE OF A WARM FRONT LIFT THEM BACK TO VFR. EXPECT
PRECIPITATION COVERAGE TO BECOME MORE WIDESPREAD TONIGHT AHEAD OF
AN ADVANCING COLD FRONT...BUT LIMITED THUNDER MENTION TO VCTS UNTIL
COVERAGE IS BETTER DEFINED. CIGS SHOULD GRADUALLY DROP BACK TO
MVFR AS PRECIP EXPANDS TONIGHT. GUSTY SOUTHERLY WINDS ARE EXPECTED
TODAY...ESPECIALLY TOWARD MIDDAY IN THE WAKE OF THE WARM FRONT.
EXPECT THE GUSTS TO DROP OFF TONIGHT AWAY FROM ANY STORMS...BUT
THEY SHOULD HOLD ABOVE 10 KTS.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
327 AM CDT SAT OCT 13 2012
.DISCUSSION...
ISSUED 327 AM CDT SAT OCT 13 2012
SHORT TERM...TODAY THROUGH SUNDAY
MAIN CONCERNS THIS FORECAST PERIOD WILL BE ANTICIPATED CONVECTION
AND ANY ASSOCIATED STRONG/SEVERE STORMS AND HEAVY RAINFALL.
ELEVATED CONVECTION WAS ONGOING IN NORTHERN IL...AS WELL AS
NORTHERN AND CENTRAL MO. THIS WAS ASSOCIATED WITH LOWER LEVEL WARM
AIR ADVECTION/ISENTROPIC LIFT. THE GFS 300K SURFACE INDICATED THAT
THIS WILL CONTINUE THROUGH MUCH OF THE MORNING IN NORTHERN AND
CENTRAL IL. THE HRRR MODEL CONCURS THAT PERIODS OF SHOWERS AND
T-STORMS CAN BE EXPECTED THIS MORNING... ESPECIALLY ALONG AND
NORTH OF A TAYLORVILLE- DANVILLE LINE.
HIGH TEMPERATURES...AND PARTICULARLY SFC BASED INSTABILITY...WILL BE
CHALLENGING BECAUSE OF CONVECTIVE DEBRIS AS WELL AS PLENTY OF LOW
LEVEL MOISTURE AND AN INVERSION ON FORECAST SOUNDINGS UNTIL LATE
THIS AFTERNOON IN CENTRAL IL. WILL KNOCK DOWN HIGH TEMPS IN CENTRAL
IL AS A RESULT...BUT KEEP WARMER READINGS IN THE SOUTHEAST.
DESPITE MARGINAL INSTABILITY IN MOST AREAS THIS EVENING...INCREASING
UPPER LEVEL DIVERGENCE AHEAD OF AN UPPER LOW IN NORTHEAST KS ALONG
WITH 30-40KTS OF BULK SHEAR WILL RESULT IN A DEVELOPING LINE OF
STORMS APPROACHING WEST CENTRAL IL LATE THIS EVENING.
UNIDIRECTIONAL FLOW ALOFT AND INCREASING LOW LEVEL WINDS BELOW
850 MB COULD RESULT IN GUSTY WINDS WITH THE STRONGEST STORMS.
WITH EACH SUCCESSIVE MODEL RUN A BIT SLOWER...AM NOT EXPECTING THE
T-STORMS TO REACH EXTREME EAST AND SOUTHEAST IL UNTIL VERY LATE
TONIGHT. EXPECT SHOWERS AND ISOLATED T-STORMS TO LINGER IN
CENTRAL IL MUCH OF THE DAY SUNDAY AHEAD OF THE UPPER LEVEL TROUGH
AXIS...BEFORE DEPARTING THE STATE LATE SUNDAY NIGHT.
LONG TERM...MONDAY THROUGH FRIDAY
A SEMI-ZONAL FLOW WILL DEVELOP AFTER THE UPPER LEVEL TROF
DEAMPLIFIES AND LIFTS THROUGH THE NEW ENGLAND STATES LATER MONDAY
AND TUESDAY. THIS WILL RESULT IN TEMPERATURES CLOSE TO SEASONAL
NORMALS FOR MID-OCTOBER.
THE NEXT CHANCE FOR PRECIPTIATION IS EXPECTED LATE TUESDAY
NIGHT...BUT PARTICULARLY WEDNESDAY AS AN UPPER LEVEL TROUGH FROM
THE PACIFIC NORTHWEST CROSSES INTO THE NORTHERN PLAINS AND DEEPENS
IN THE UPPER MIDWEST. THERE IS CONSIDERABLE MODEL UNCERTAINTY AT
THIS POINT WITH THE SPEED OF THE SYSTEM AND JUST HOW FAR SOUTH THE
UPPER LEVEL LOW WILL DEVELOP AND HOW STRONG IT WILL BE. FOR NOW
WILL GO WITH SHOWERS AND A FEW T-STORMS AHEAD OF THE SURFACE COLD
FRONT WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY SOMEWHAT COOLER
TEMPERATURES IN THE LOWER TO MIDDLE 60S.
WILL NEED TO KEEP AN EYE ON THIS SYSTEM BECAUSE IF THE UPPER LOW
SETTLES OVER THE MIDWEST THEN TEMPERATURES WILL BE QUITE CHILLY
WITH RAINY CONDITIONS FOR FRIDAY AND BEYOND.
MILLER
&&
.AVIATION...
ISSUED 1150 PM CDT FRI OCT 12 2012...FOR THE 06Z TAFS
AN INITIAL LINE OF SHOWERS AND STORMS WILL PRIMARILY PASS JUST TO
THE NORTHWEST OF PIA...BUT THE SOUTHERN EDGE OF THE LINE MAY COME
CLOSE TO THE PIA AIRPORT. WE WILL CONTINUE WITH VCSH INSTEAD OF
VCTS AS WE DO NOT EXPECT LIGHTNING AT THE AIRPORT. THE NEAREST
STORM CELL IS PROJECTED TO PASS WELL TO THE NORTH OF PIA. MVFR
CLOUD HEIGHTS WILL BE POSSIBLE FOR PIA/BMI/SPI OVERNIGHT.
THE NEXT WAVE OF STORMS FARTHER TO THE SOUTHWEST ARE PROJECTED TO
ARRIVE AFTER SUNRISE ON SATURDAY...AND EXPAND TO COVER AREAS
CLOSER TO THE REMAINING TAF SITES. WE WILL INCLUDE SOME VCSH FOR
THE DAYTIME HOURS...BEGINNING 14Z AT PIA/SPI AND PROGRESSING TO
18Z AT CMI/DEC. SOME MVFR CLOUDS MAY OCCUR DURING THE MORNING AS
MOISTURES LEVELS INCREASE NEAR THE SURFACE. WE CANT RULE OUT A
BRIEF PERIOD OF IFR AS WELL...BUT WILL NOT INCLUDE THAT LOW AT
THIS POINT.
THE BEST CHANCES FOR STRONGER STORMS WILL STILL BE LATE EVENING
NEAR PIA...AND FOR AFTER MIDNIGHT SAT NIGHT FOR THE REMAINING TAF
SITES...WHICH IS BEYOND THIS TAF PERIOD.
WILL INCLUDE A BREAK IN THE RAIN CHANCES FOR MOST OF SATURDAY EVENING
FOR THE TAFS.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1243 PM CDT SAT OCT 13 2012
.UPDATE 13/18Z AVIATION DISCUSSION...
.SHORT TERM FORECAST /TODAY/...
FIRST MCS TIED TO STRONG THETAE ADVECTION NOW EAST OF THE AREA WITH
NEXT ROUND OF WARM AIR ADVECTION STORMS HEADING NORTHEAST INTO
SOUTHEAST SECTIONS. FOR NOW...INSTABILITY REMAINS LOW AT THIS TIME
AND MAIN WAVE OVER NEW MEXICO THIS MORNING NOW TURNING NORTH INTO
WESTERN KS/OK/TX AT THIS TIME. THOUGH COLD FRONT REMAINS FAR
NORTHWEST AT THIS TIME...ANOTHER WARM FRONT OVER EASTERN KS/NEBRASKA
WILL MOVE NORTHEAST LATE THIS AFTERNOON AND SHOULD BRING THE
SOUTHERN SECTIONS INTO THE WARM SECTOR AS INSTABILITY INCREASES BY
LATE AFTERNOON. MAIN CONCERNS REMAIN THE SOUTHEAST WHICH SHOULD SEE
BETTER CHANCES FOR SEVERE THIS AFTERNOON AND EVENING HOURS AS THE
SFC LOW CONSOLIDATES AND HEADS INTO NORTHEAST KS/NORTHWEST MO BY
00Z. STRONGER UPPER LEVEL WIND FIELDS REMAIN SOUTH AND EAST OF
FORECAST AREA THIS AFTERNOON...BUT ENOUGH SHEAR STILL EXISTS FOR
SEVERE STORM POTENTIAL. HAVE TRIMMED SEVERE CHANCES BACK TO AFT 21Z
WITH LESSER CHANCES FOR THUNDER MOST AREAS THIS AFTERNOON WITH THE
EXCEPTION OF THE SOUTHEAST WHERE NEXT AREA OF STORMS CURRENTLY OVER
MO WILL IMPACT REGION YET BEFORE 21Z. HIGHS LOOK SLIGHTLY COOLER
NORTH AND HAVE REDUCED HIGHS THERE BY A FEW DEGREES AS WELL.
.PREVIOUS SHORT TERM /TODAY/...
MAIN CONCERN THIS MORNING IS OBVIOUSLY CONVECTIVE TRENDS. LONG WAVE
TROUGH CONTINUES TO MOVE ACROSS THE ROCKIES WITH ASSOCIATED WARM
FRONT FROM WY/SD SURFACE LOW THROUGH MO VALLEY. RAP ANALYSIS
APPEARS TO BE HANDLING CURRENT WEATHER WELL SHOWING INTENSIFYING
THETA-E ADVECTION COINCIDENT WITH NARROW NW-SE MCS FROM NE INTO MO.
REMNANT MCS THAT FORMED NEAR PARENT UPPER LOW IN THE ROCKIES
CONTINUES TO ADVANCE ACROSS KS INTO NE...MERGING WITH WARM ADVECTION
CONVECTION. RAP 300-310K ISENT LAYER ROOTED AT TOP OF INVERSION
ADVANCES THIS MCS INTO IA AND MATURES IT THROUGH THE MORNING WITH
STRONG MOISTURE TRANSPORT. ELEVATED CAPES APPEAR TO BE AROUND 1000
J/KG WITH MARGINAL EFFECTIVE SHEAR UPSTREAM INTO IMMEDIATE MO RIVER
VALLEY. HOWEVER ESTIMATED RAP EFFECTIVE SHEAR /1-6KM/ WANES SO
REALLY DO NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER THIS
MORNING...JUST MUCH NEEDED RAIN. THE LATEST HRRR SUPPORTS THIS AS
WELL AND SEEMS TO BE CLOSER TO REALITY...UNLIKE MOST WRF RUNS...SO
WIDESPREAD CATEGORICAL POPS HAVE BEEN INCLUDED.
QUESTION BY THIS AFTERNOON TURNS TO SEVERE WEATHER POTENTIAL ALONG
WITH LESS CONFIDENCE. 60F PLUS DEWPOINTS CURRENTLY NOTED SOUTH OF
WARM FRONT ACROSS KS SHOULD ENTER IA BY THIS AFTERNOON RESULTING IN
MAX MLCAPES AROUND 1500 J/KG AND LITTLE CINH. THIS THERMODYNAMIC
ENVIRONMENT WOULD BE COINCIDENT WITH FAVORABLE DEEP SHEAR FOR
SUPERCELLS AND SHALLOW SHEAR FOR A FEW TORNADOES...ESPECIALLY S
CENTRAL/SE LATE. AGREE WITH SPC LOW TOR PROBS SOUTH BECAUSE OF
THIS...BUT UNIDIRECTIONAL S/SWLY FLOW IS NOT TOO CONDUCIVE.
HOWEVER ANOTHER QUESTION WILL BE INITIATION OR SOURCE. FRONTAL
SYSTEM AND CONVERGENCE WILL LAG THIS AREA CONSIDERABLY...STILL BACK
INTO KS/NE/NWRN IA BY 00Z...AS IS STRONGER H7/H5 FORCING IMMEDIATELY
AHEAD OF PARENT LOW. MINOR WAVES AND H85/H7 FORCING EJECTING OUT IN
SWLY UPPER FLOW COULD FORM ANOTHER MCS...OR REMNANTS FROM SRN TAIL
END OF CURRENT KS CONVECTION COULD EVENTUALLY REACH IA. HOWEVER
THIS DEVELOPMENTAL UNCERTAINTY...AND THE POTENTIAL THAT MORNING MCS
COULD HINDER THE THERMODYNAMIC ENVIRONMENT...HAS MADE THIS SEVERE
WEATHER CONDITIONAL AND LESS CERTAIN. MANY MODELS STILL DEVELOP
SOMETHING FROM THE SOUTH INTO SRN IA HOWEVER SO ALTHOUGH DETAILS NOT
CLEAR...HAVE INTRODUCED SEVERE WORDING SOUTH.
REGARDLESS OF PRECIP TRENDS...AIRMASS SHOULD FEEL SUMMERLIKE WITH
MODEL CONSENSUS PUSHING HIGHS INTO THE 70S AND DEWPOINTS INTO THE
60S. RAW MODEL TEMPS AND MOS GUIDANCE ALL SEEM TO BE IN AGREEMENT
ON THIS.
.LONG TERM /TONIGHT THRU FRIDAY/...
MODELS HAVE COME TOGETHER FOR THE MOST PART WITH THE TIMING AND
EVOLUTION OF THE LOW THIS EVENING. SURFACE LOW WILL TRACK ACROSS
IOWA...MOST LIKELY THE SOUTH HALF...THIS EVENING AND KEPT A SHORT
WINDOW FOR POTENTIAL SEVERE. THAT WILL BE OUT OF THE PICTURE BY
03Z. CHANGE IN THE EVOLUTION FROM PREVIOUS RUNS IS THE TRACK A BIT
FARTHER SOUTH...RESULTING IN A DECENT DEFORMATION ZONE CROSSING IOWA
TONIGHT AND LINGERING WELL IN TO SUNDAY MORNING. MADE ADJUSTMENTS
TO COVER THAT BOTH WITH INCREASING POPS AS WELL AS LOWERING MAX
TEMPS FOR SUN. THE NEXT WEATHER SYSTEM IS SLATED TO ARRIVE MID
WEEK. A BIG DIFFERENCE BETWEEN THE GEM AND ECMWF SOLUTIONS AND THE
GFS WITH THE DEEPENING OF THE UPPER LOW. GEM AND EC BOTH SUGGEST
COOLER AND WETTER WEATHER IS IN STORE. CURRENTLY...PRECIP IS IN FOR
THE WED TIME FRAME. KEPT IT IN THE NERN ZONES FOR THE LATER PART OF
THE WEEK...BUT MAY HAVE TO BE ADJUSTED FARTHER SOUTH AND WEST WITH
LATER PACKAGES. WITH THE SYSTEM DURING MID WEEK BEING FROM THE
NORTHERN STREAM INSTEAD OF THE SOUTHERN BRANCH...DON`T SEE THE
THUNDER THREAT AS BEING A BIG DEAL.
&&
.AVIATION...13/18Z
CONTINUE TO DEAL WITH MVFR AND IFR CIGS THIS AFTERNOON WITH SOME
LIFTING OF CEILINGS OVER WESTERN AND CENTRAL SECTIONS AS WARM FRONT
LIFTS NORTH. INSTABILITY TO INCREASE WITH SOME INSOLATION TODAY AND
HAVE INTRODUCED THUNDER AGAIN INTO THE SOUTH TAFS BY LATE AFTERNOON
AND WILL CONTINUE THROUGH NEAR 12Z AS LOW SLOWLY MOVES EAST WITH
TIME. SOME QUESTIONS REGARDING COVERAGE AND TIMING AS MAIN WAVE WILL
ARRIVE BY LATE AFTERNOON AND EARLY EVENING. WINDS TO REMAIN SOUTH
UNTIL FRONT ARRIVES LATE TONIGHT AND EARLY MORNING. WINDS BECOME NW
BETWEEN 09-13Z AND INCREASE THROUGH THE MORNING HOURS. CIGS WILL
SLOWLY IMPROVE TOWARD END OF PERIOD FROM THE NW TO THE SOUTHEAST.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
AVIATION...SMALL
LONG TERM...MS OCT 12
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1132 AM CDT SAT OCT 13 2012
.UPDATE PUBLIC DISCUSSION...
.SHORT TERM FORECAST /TODAY/...
FIRST MCS TIED TO STRONG THETAE ADVECTION NOW EAST OF THE AREA WITH
NEXT ROUND OF WARM AIR ADVECTION STORMS HEADING NORTHEAST INTO
SOUTHEAST SECTIONS. FOR NOW...INSTABILITY REMAINS LOW AT THIS TIME
AND MAIN WAVE OVER NEW MEXICO THIS MORNING NOW TURNING NORTH INTO
WESTERN KS/OK/TX AT THIS TIME. THOUGH COLD FRONT REMAINS FAR
NORTHWEST AT THIS TIME...ANOTHER WARM FRONT OVER EASTERN KS/NEBRASKA
WILL MOVE NORTHEAST LATE THIS AFTERNOON AND SHOULD BRING THE
SOUTHERN SECTIONS INTO THE WARM SECTOR AS INSTABILITY INCREASES BY
LATE AFTERNOON. MAIN CONCERNS REMAIN THE SOUTHEAST WHICH SHOULD SEE
BETTER CHANCES FOR SEVERE THIS AFTERNOON AND EVENING HOURS AS THE
SFC LOW CONSOLIDATES AND HEADS INTO NORTHEAST KS/NORTHWEST MO BY
00Z. STRONGER UPPER LEVEL WIND FIELDS REMAIN SOUTH AND EAST OF
FORECAST AREA THIS AFTERNOON...BUT ENOUGH SHEAR STILL EXISTS FOR
SEVERE STORM POTENTIAL. HAVE TRIMMED SEVERE CHANCES BACK TO AFT 21Z
WITH LESSER CHANCES FOR THUNDER MOST AREAS THIS AFTERNOON WITH THE
EXCEPTION OF THE SOUTHEAST WHERE NEXT AREA OF STORMS CURRENTLY OVER
MO WILL IMPACT REGION YET BEFORE 21Z. HIGHS LOOK SLIGHTLY COOLER
NORTH AND HAVE REDUCED HIGHS THERE BY A FEW DEGREES AS WELL.
.PREVIOUS SHORT TERM /TODAY/...
MAIN CONCERN THIS MORNING IS OBVIOUSLY CONVECTIVE TRENDS. LONG WAVE
TROUGH CONTINUES TO MOVE ACROSS THE ROCKIES WITH ASSOCIATED WARM
FRONT FROM WY/SD SURFACE LOW THROUGH MO VALLEY. RAP ANALYSIS
APPEARS TO BE HANDLING CURRENT WEATHER WELL SHOWING INTENSIFYING
THETA-E ADVECTION COINCIDENT WITH NARROW NW-SE MCS FROM NE INTO MO.
REMNANT MCS THAT FORMED NEAR PARENT UPPER LOW IN THE ROCKIES
CONTINUES TO ADVANCE ACROSS KS INTO NE...MERGING WITH WARM ADVECTION
CONVECTION. RAP 300-310K ISENT LAYER ROOTED AT TOP OF INVERSION
ADVANCES THIS MCS INTO IA AND MATURES IT THROUGH THE MORNING WITH
STRONG MOISTURE TRANSPORT. ELEVATED CAPES APPEAR TO BE AROUND 1000
J/KG WITH MARGINAL EFFECTIVE SHEAR UPSTREAM INTO IMMEDIATE MO RIVER
VALLEY. HOWEVER ESTIMATED RAP EFFECTIVE SHEAR /1-6KM/ WANES SO
REALLY DO NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER THIS
MORNING...JUST MUCH NEEDED RAIN. THE LATEST HRRR SUPPORTS THIS AS
WELL AND SEEMS TO BE CLOSER TO REALITY...UNLIKE MOST WRF RUNS...SO
WIDESPREAD CATEGORICAL POPS HAVE BEEN INCLUDED.
QUESTION BY THIS AFTERNOON TURNS TO SEVERE WEATHER POTENTIAL ALONG
WITH LESS CONFIDENCE. 60F PLUS DEWPOINTS CURRENTLY NOTED SOUTH OF
WARM FRONT ACROSS KS SHOULD ENTER IA BY THIS AFTERNOON RESULTING IN
MAX MLCAPES AROUND 1500 J/KG AND LITTLE CINH. THIS THERMODYNAMIC
ENVIRONMENT WOULD BE COINCIDENT WITH FAVORABLE DEEP SHEAR FOR
SUPERCELLS AND SHALLOW SHEAR FOR A FEW TORNADOES...ESPECIALLY S
CENTRAL/SE LATE. AGREE WITH SPC LOW TOR PROBS SOUTH BECAUSE OF
THIS...BUT UNIDIRECTIONAL S/SWLY FLOW IS NOT TOO CONDUCIVE.
HOWEVER ANOTHER QUESTION WILL BE INITIATION OR SOURCE. FRONTAL
SYSTEM AND CONVERGENCE WILL LAG THIS AREA CONSIDERABLY...STILL BACK
INTO KS/NE/NWRN IA BY 00Z...AS IS STRONGER H7/H5 FORCING IMMEDIATELY
AHEAD OF PARENT LOW. MINOR WAVES AND H85/H7 FORCING EJECTING OUT IN
SWLY UPPER FLOW COULD FORM ANOTHER MCS...OR REMNANTS FROM SRN TAIL
END OF CURRENT KS CONVECTION COULD EVENTUALLY REACH IA. HOWEVER
THIS DEVELOPMENTAL UNCERTAINTY...AND THE POTENTIAL THAT MORNING MCS
COULD HINDER THE THERMODYNAMIC ENVIRONMENT...HAS MADE THIS SEVERE
WEATHER CONDITIONAL AND LESS CERTAIN. MANY MODELS STILL DEVELOP
SOMETHING FROM THE SOUTH INTO SRN IA HOWEVER SO ALTHOUGH DETAILS NOT
CLEAR...HAVE INTRODUCED SEVERE WORDING SOUTH.
REGARDLESS OF PRECIP TRENDS...AIRMASS SHOULD FEEL SUMMERLIKE WITH
MODEL CONSENSUS PUSHING HIGHS INTO THE 70S AND DEWPOINTS INTO THE
60S. RAW MODEL TEMPS AND MOS GUIDANCE ALL SEEM TO BE IN AGREEMENT
ON THIS.
.LONG TERM /TONIGHT THRU FRIDAY/...
MODELS HAVE COME TOGETHER FOR THE MOST PART WITH THE TIMING AND
EVOLUTION OF THE LOW THIS EVENING. SURFACE LOW WILL TRACK ACROSS
IOWA...MOST LIKELY THE SOUTH HALF...THIS EVENING AND KEPT A SHORT
WINDOW FOR POTENTIAL SEVERE. THAT WILL BE OUT OF THE PICTURE BY
03Z. CHANGE IN THE EVOLUTION FROM PREVIOUS RUNS IS THE TRACK A BIT
FARTHER SOUTH...RESULTING IN A DECENT DEFORMATION ZONE CROSSING IOWA
TONIGHT AND LINGERING WELL IN TO SUNDAY MORNING. MADE ADJUSTMENTS
TO COVER THAT BOTH WITH INCREASING POPS AS WELL AS LOWERING MAX
TEMPS FOR SUN. THE NEXT WEATHER SYSTEM IS SLATED TO ARRIVE MID
WEEK. A BIG DIFFERENCE BETWEEN THE GEM AND ECMWF SOLUTIONS AND THE
GFS WITH THE DEEPENING OF THE UPPER LOW. GEM AND EC BOTH SUGGEST
COOLER AND WETTER WEATHER IS IN STORE. CURRENTLY...PRECIP IS IN FOR
THE WED TIME FRAME. KEPT IT IN THE NERN ZONES FOR THE LATER PART OF
THE WEEK...BUT MAY HAVE TO BE ADJUSTED FARTHER SOUTH AND WEST WITH
LATER PACKAGES. WITH THE SYSTEM DURING MID WEEK BEING FROM THE
NORTHERN STREAM INSTEAD OF THE SOUTHERN BRANCH...DON`T SEE THE
THUNDER THREAT AS BEING A BIG DEAL.
&&
.AVIATION...13/12Z
PERIOD OF IFR CONDITIONS ANTICIPATED EARLY THIS MORNING AS SHOWERS
AND THUNDERSTORMS MOVE THROUGH. THIS SHOULD BE FOLLOWED BY A BREAK
IN THE PRECIPITATION BUT PERSISTENT STRATUS WILL MAINTAIN ITSELF
WITH MVFR CIGS MOST PROMINENT. COULD BE LOWER BUT CONFIDENCE IN
THAT TIMING ENOUGH TO MENTION. ADDITIONAL SHOWERS AND STORMS MAY
DEVELOP THIS AFTERNOON AND EVENING SOUTH. LOW CONFIDENCE ON TIMING
AND LOCATION HOWEVER SO NOTHING MORE THAN MVFR OR LESS CIGS AND
VCSH. FARTHER NORTH STRATUS WILL PERSIST...BUT POTENTIAL FOR
THUNDER IS LESS AND MORE LIKELY JUST STEADY RAIN OR SHOWERS DURING
THE EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
AVIATION...SMALL
LONG TERM...MS OCT 12
AREA FORECAST DISCUSSION
NWS DES MOINES IA
711 AM CDT SAT OCT 13 2012
.SHORT TERM /TODAY/...
MAIN CONCERN THIS MORNING IS OBVIOUSLY CONVECTIVE TRENDS. LONG WAVE
TROUGH CONTINUES TO MOVE ACROSS THE ROCKIES WITH ASSOCIATED WARM
FRONT FROM WY/SD SURFACE LOW THROUGH MO VALLEY. RAP ANALYSIS
APPEARS TO BE HANDLING CURRENT WEATHER WELL SHOWING INTENSIFYING
THETA-E ADVECTION COINCIDENT WITH NARROW NW-SE MCS FROM NE INTO MO.
REMNANT MCS THAT FORMED NEAR PARENT UPPER LOW IN THE ROCKIES
CONTINUES TO ADVANCE ACROSS KS INTO NE...MERGING WITH WARM ADVECTION
CONVECTION. RAP 300-310K ISENT LAYER ROOTED AT TOP OF INVERSION
ADVANCES THIS MCS INTO IA AND MATURES IT THROUGH THE MORNING WITH
STRONG MOISTURE TRANSPORT. ELEVATED CAPES APPEAR TO BE AROUND 1000
J/KG WITH MARGINAL EFFECTIVE SHEAR UPSTREAM INTO IMMEDIATE MO RIVER
VALLEY. HOWEVER ESTIMATED RAP EFFECTIVE SHEAR /1-6KM/ WANES SO
REALLY DO NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER THIS
MORNING...JUST MUCH NEEDED RAIN. THE LATEST HRRR SUPPORTS THIS AS
WELL AND SEEMS TO BE CLOSER TO REALITY...UNLIKE MOST WRF RUNS...SO
WIDESPREAD CATEGORICAL POPS HAVE BEEN INCLUDED.
QUESTION BY THIS AFTERNOON TURNS TO SEVERE WEATHER POTENTIAL ALONG
WITH LESS CONFIDENCE. 60F PLUS DEWPOINTS CURRENTLY NOTED SOUTH OF
WARM FRONT ACROSS KS SHOULD ENTER IA BY THIS AFTERNOON RESULTING IN
MAX MLCAPES AROUND 1500 J/KG AND LITTLE CINH. THIS THERMODYNAMIC
ENVIRONMENT WOULD BE COINCIDENT WITH FAVORABLE DEEP SHEAR FOR
SUPERCELLS AND SHALLOW SHEAR FOR A FEW TORNADOES...ESPECIALLY S
CENTRAL/SE LATE. AGREE WITH SPC LOW TOR PROBS SOUTH BECAUSE OF
THIS...BUT UNIDIRECTIONAL S/SWLY FLOW IS NOT TOO CONDUCIVE.
HOWEVER ANOTHER QUESTION WILL BE INITIATION OR SOURCE. FRONTAL
SYSTEM AND CONVERGENCE WILL LAG THIS AREA CONSIDERABLY...STILL BACK
INTO KS/NE/NWRN IA BY 00Z...AS IS STRONGER H7/H5 FORCING IMMEDIATELY
AHEAD OF PARENT LOW. MINOR WAVES AND H85/H7 FORCING EJECTING OUT IN
SWLY UPPER FLOW COULD FORM ANOTHER MCS...OR REMNANTS FROM SRN TAIL
END OF CURRENT KS CONVECTION COULD EVENTUALLY REACH IA. HOWEVER
THIS DEVELOPMENTAL UNCERTAINTY...AND THE POTENTIAL THAT MORNING MCS
COULD HINDER THE THERMODYNAMIC ENVIRONMENT...HAS MADE THIS SEVERE
WEATHER CONDITIONAL AND LESS CERTAIN. MANY MODELS STILL DEVELOP
SOMETHING FROM THE SOUTH INTO SRN IA HOWEVER SO ALTHOUGH DETAILS NOT
CLEAR...HAVE INTRODUCED SEVERE WORDING SOUTH.
REGARDLESS OF PRECIP TRENDS...AIRMASS SHOULD FEEL SUMMERLIKE WITH
MODEL CONSENSUS PUSHING HIGHS INTO THE 70S AND DEWPOINTS INTO THE
60S. RAW MODEL TEMPS AND MOS GUIDANCE ALL SEEM TO BE IN AGREEMENT
ON THIS.
.LONG TERM /TONIGHT THRU FRIDAY/...
MODELS HAVE COME TOGETHER FOR THE MOST PART WITH THE TIMING AND
EVOLUTION OF THE LOW THIS EVENING. SURFACE LOW WILL TRACK ACROSS
IOWA...MOST LIKELY THE SOUTH HALF...THIS EVENING AND KEPT A SHORT
WINDOW FOR POTENTIAL SEVERE. THAT WILL BE OUT OF THE PICTURE BY
03Z. CHANGE IN THE EVOLUTION FROM PREVIOUS RUNS IS THE TRACK A BIT
FARTHER SOUTH...RESULTING IN A DECENT DEFORMATION ZONE CROSSING IOWA
TONIGHT AND LINGERING WELL IN TO SUNDAY MORNING. MADE ADJUSTMENTS
TO COVER THAT BOTH WITH INCREASING POPS AS WELL AS LOWERING MAX
TEMPS FOR SUN. THE NEXT WEATHER SYSTEM IS SLATED TO ARRIVE MID
WEEK. A BIG DIFFERENCE BETWEEN THE GEM AND ECMWF SOLUTIONS AND THE
GFS WITH THE DEEPENING OF THE UPPER LOW. GEM AND EC BOTH SUGGEST
COOLER AND WETTER WEATHER IS IN STORE. CURRENTLY...PRECIP IS IN FOR
THE WED TIME FRAME. KEPT IT IN THE NERN ZONES FOR THE LATER PART OF
THE WEEK...BUT MAY HAVE TO BE ADJUSTED FARTHER SOUTH AND WEST WITH
LATER PACKAGES. WITH THE SYSTEM DURING MID WEEK BEING FROM THE
NORTHERN STREAM INSTEAD OF THE SOUTHERN BRANCH...DON`T SEE THE
THUNDER THREAT AS BEING A BIG DEAL.
&&
.AVIATION...13/12Z
PERIOD OF IFR CONDITIONS ANTICIPATED EARLY THIS MORNING AS SHOWERS
AND THUNDERSTORMS MOVE THROUGH. THIS SHOULD BE FOLLOWED BY A BREAK
IN THE PRECIPITATION BUT PERSISTENT STRATUS WILL MAINTAIN ITSELF
WITH MVFR CIGS MOST PROMINENT. COULD BE LOWER BUT CONFIDENCE IN
THAT TIMING ENOUGH TO MENTION. ADDITIONAL SHOWERS AND STORMS MAY
DEVELOP THIS AFTERNOON AND EVENING SOUTH. LOW CONFIDENCE ON TIMING
AND LOCATION HOWEVER SO NOTHING MORE THAN MVFR OR LESS CIGS AND
VCSH. FARTHER NORTH STRATUS WILL PERSIST...BUT POTENTIAL FOR
THUNDER IS LESS AND MORE LIKELY JUST STEADY RAIN OR SHOWERS DURING
THE EVENING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...SMALL
LONG TERM...MS OCT 12
AREA FORECAST DISCUSSION
NWS DES MOINES IA
338 AM CDT SAT OCT 13 2012
.SHORT TERM /TODAY/...
MAIN CONCERN THIS MORNING IS OBVIOUSLY CONVECTIVE TRENDS. LONG WAVE
TROUGH CONTINUES TO MOVE ACROSS THE ROCKIES WITH ASSOCIATED WARM
FRONT FROM WY/SD SURFACE LOW THROUGH MO VALLEY. RAP ANALYSIS
APPEARS TO BE HANDLING CURRENT WEATHER WELL SHOWING INTENSIFYING
THETA-E ADVECTION COINCIDENT WITH NARROW NW-SE MCS FROM NE INTO MO.
REMNANT MCS THAT FORMED NEAR PARENT UPPER LOW IN THE ROCKIES
CONTINUES TO ADVANCE ACROSS KS INTO NE...MERGING WITH WARM ADVECTION
CONVECTION. RAP 300-310K ISENT LAYER ROOTED AT TOP OF INVERSION
ADVANCES THIS MCS INTO IA AND MATURES IT THROUGH THE MORNING WITH
STRONG MOISTURE TRANSPORT. ELEVATED CAPES APPEAR TO BE AROUND 1000
J/KG WITH MARGINAL EFFECTIVE SHEAR UPSTREAM INTO IMMEDIATE MO RIVER
VALLEY. HOWEVER ESTIMATED RAP EFFECTIVE SHEAR /1-6KM/ WANES SO
REALLY DO NOT EXPECT MUCH IN THE WAY OF SEVERE WEATHER THIS
MORNING...JUST MUCH NEEDED RAIN. THE LATEST HRRR SUPPORTS THIS AS
WELL AND SEEMS TO BE CLOSER TO REALITY...UNLIKE MOST WRF RUNS...SO
WIDESPREAD CATEGORICAL POPS HAVE BEEN INCLUDED.
QUESTION BY THIS AFTERNOON TURNS TO SEVERE WEATHER POTENTIAL ALONG
WITH LESS CONFIDENCE. 60F PLUS DEWPOINTS CURRENTLY NOTED SOUTH OF
WARM FRONT ACROSS KS SHOULD ENTER IA BY THIS AFTERNOON RESULTING IN
MAX MLCAPES AROUND 1500 J/KG AND LITTLE CINH. THIS THERMODYNAMIC
ENVIRONMENT WOULD BE COINCIDENT WITH FAVORABLE DEEP SHEAR FOR
SUPERCELLS AND SHALLOW SHEAR FOR A FEW TORNADOES...ESPECIALLY S
CENTRAL/SE LATE. AGREE WITH SPC LOW TOR PROBS SOUTH BECAUSE OF
THIS...BUT UNIDIRECTIONAL S/SWLY FLOW IS NOT TOO CONDUCIVE.
HOWEVER ANOTHER QUESTION WILL BE INITIATION OR SOURCE. FRONTAL
SYSTEM AND CONVERGENCE WILL LAG THIS AREA CONSIDERABLY...STILL BACK
INTO KS/NE/NWRN IA BY 00Z...AS IS STRONGER H7/H5 FORCING IMMEDIATELY
AHEAD OF PARENT LOW. MINOR WAVES AND H85/H7 FORCING EJECTING OUT IN
SWLY UPPER FLOW COULD FORM ANOTHER MCS...OR REMNANTS FROM SRN TAIL
END OF CURRENT KS CONVECTION COULD EVENTUALLY REACH IA. HOWEVER
THIS DEVELOPMENTAL UNCERTAINTY...AND THE POTENTIAL THAT MORNING MCS
COULD HINDER THE THERMODYNAMIC ENVIRONMENT...HAS MADE THIS SEVERE
WEATHER CONDITIONAL AND LESS CERTAIN. MANY MODELS STILL DEVELOP
SOMETHING FROM THE SOUTH INTO SRN IA HOWEVER SO ALTHOUGH DETAILS NOT
CLEAR...HAVE INTRODUCED SEVERE WORDING SOUTH.
REGARDLESS OF PRECIP TRENDS...AIRMASS SHOULD FEEL SUMMERLIKE WITH
MODEL CONSENSUS PUSHING HIGHS INTO THE 70S AND DEWPOINTS INTO THE
60S. RAW MODEL TEMPS AND MOS GUIDANCE ALL SEEM TO BE IN AGREEMENT
ON THIS.
.LONG TERM /TONIGHT THRU FRIDAY/...
MODELS HAVE COME TOGETHER FOR THE MOST PART WITH THE TIMING AND
EVOLUTION OF THE LOW THIS EVENING. SURFACE LOW WILL TRACK ACROSS
IOWA...MOST LIKELY THE SOUTH HALF...THIS EVENING AND KEPT A SHORT
WINDOW FOR POTENTIAL SEVERE. THAT WILL BE OUT OF THE PICTURE BY
03Z. CHANGE IN THE EVOLUTION FROM PREVIOUS RUNS IS THE TRACK A BIT
FARTHER SOUTH...RESULTING IN A DECENT DEFORMATION ZONE CROSSING IOWA
TONIGHT AND LINGERING WELL IN TO SUNDAY MORNING. MADE ADJUSTMENTS
TO COVER THAT BOTH WITH INCREASING POPS AS WELL AS LOWERING MAX
TEMPS FOR SUN. THE NEXT WEATHER SYSTEM IS SLATED TO ARRIVE MID
WEEK. A BIG DIFFERENCE BETWEEN THE GEM AND ECMWF SOLUTIONS AND THE
GFS WITH THE DEEPENING OF THE UPPER LOW. GEM AND EC BOTH SUGGEST
COOLER AND WETTER WEATHER IS IN STORE. CURRENTLY...PRECIP IS IN FOR
THE WED TIME FRAME. KEPT IT IN THE NERN ZONES FOR THE LATER PART OF
THE WEEK...BUT MAY HAVE TO BE ADJUSTED FARTHER SOUTH AND WEST WITH
LATER PACKAGES. WITH THE SYSTEM DURING MID WEEK BEING FROM THE
NORTHERN STREAM INSTEAD OF THE SOUTHERN BRANCH...DON`T SEE THE
THUNDER THREAT AS BEING A BIG DEAL.
&&
.AVIATION...13/06Z
SHOWERS AND POSSIBLE THUNDERSTORMS EXPECTED TO SPREAD ACROSS THE
STATE THROUGH 06Z TO 09Z AND CONTINUE INTO MID MORNING SATURDAY.
EXPECT A POSSIBLE BREAK IN THE PRECIP BY LATE MORNING INTO THE EARLY
AFTERNOON HOURS WITH SHOWERS AND THUNDERSTORMS EXPECTED TO REDEVELOP
BY MID TO LATE AFTERNOON AND CONTINUE THROUGH THE EVENING HOURS.
HIGH CONFIDENCE THAT THERE WILL BE THUNDER WITH BOTH WAVES OF
PRECIP...HOWEVER HIGH UNCERTAINTY IN TIMING AND PLACEMENT SO HAVE
LEFT MENTION OF THUNDER OUT OF THE TAFS AT THIS TIME. MAINLY MVFR
WITH POSSIBLE IFR CIGS EXPECTED THROUGHOUT THE PERIOD...AND COULD
SEE CIGS LIFT INTO LOW VFR DURING THE BREAKS IN THE PRECIP.
SOUTHERLY WINDS EXPECTED THROUGH THE PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...MS OCT 12
AVIATION...BEERENDS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
518 PM MDT SUN OCT 14 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1251 PM MDT SUN OCT 14 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW RIDGE ACROSS NORTHERN
ROCKIES WITH LARGE SCALE TROUGH STILL IN PLACE OVER UPPER
MISSISSIPPI RIVER VALLEY. NW FLOW REMAINS IN PLACE ACROSS THE PLAINS
BETWEEN THESE FEATURES. AT THE SURFACE HIGH PRESSURE IS IN PLACE
OVER EASTERN COLORADO...WITH A LARGE AREA OF LOW PRESSURE OVER THE
CENTRAL MISSISSIPPI RIVER VALLEY. BETWEEN THESE FEATURES...TIGHTENED
PRESSURE GRADIENT OVER THE CWA HAS LED TO GUSTY WINDS BETWEEN 25 AND
30 MPH. THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH AN END OF
DAYTIME MIXING.
A SURFACE TROUGH WILL DEVELOP ALONG THE KS/CO STATE LINE BY EARLY
MONDAY MORNING...WITH GRADIENT RELAXING ACROSS THE CWA. RESULT WILL
BE DEVELOPMENT OF LIGHT SW WINDS AND WAA AT H85. DESPITE WARMER
TEMPS ALOFT...CLEAR SKIES AND CALM WINDS WILL SUPPORT GOOD
RADIATIONAL COOLING OVERNIGHT. MOST LOCATIONS SHOULD SEE LOWS IN THE
LOW TO MID 40S...AND UPPER 30S AT TRADITIONAL COLD SPOTS. H5 RIDGE
WILL CONTINUE TO BUILD EAST OVERNIGHT AND SHOULD BE OVER CWA BY
EARLY MONDAY MORNING. WITH LARGE SCALE SUBSIDENCE IN PLACE MOSTLY
CLEAR SKIES AND DRY CONDITIONS SHOULD PREVAIL THROUGH MONDAY.
AIR MASS WILL CONTINUE TO MODERATE THROUGH MONDAY AFTERNOON...WITH
H85 TEMPS ABOUT 5-7C WARMER THAN THIS AFTERNOON. THIS SHOULD
SUPPORT AFTERNOON HIGH TEMPERATURES IN THE UPPER 70S TO LOW 80S
ACROSS THE CWA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 217 PM MDT SUN OCT 14 2012
LATE MONDAY NIGHT AN UPPER LEVEL SHORT WAVE TROUGH AND SURFACE
TROUGH/WEAK COLD FRONT WILL MOVE THROUGH THE NORTHEAST HALF OF THE
AREA. SOUNDINGS SHOW LITTLE MOISTURE TO WORK WITH SO AM ONLY
ANTICIPATING A FEW CLOUDS DURING THE OVERNIGHT HOURS.
TUESDAY A SHORT WAVE RIDGE AND SURFACE HIGH FOLLOW THE SURFACE
TROUGH INTO THE AREA. WINDS TURN TO THE SOUTHWEST AS THE RIDGE
BUILDS IN CAUSING TEMPERATURES TO WARM WELL ABOVE NORMAL.
TUESDAY NIGHT A STRONGER COLD FRONT MOVES INTO THE AREA DURING THE
EVENING...AND EXITS THE AREA DURING THE OVERNIGHT HOURS. THERE IS
SOME 700-500MB MOISTURE TO WORK WITH...HOWEVER A DRY LAYER WILL
STILL EXIST BELOW 700MB. MODELS DISAGREE WITH THE 500 AND 300MB
JET PLACEMENT BEHIND THE FRONT...BUT THE MAJORITY OF THE MODELS
INDICATE THE LEFT EXIT REGION OF THE JET MAY BE IN A FAVORABLE
LOCATION FOR THE NORTHERN HALF OF THE AREA TO RECEIVE PRECIP. THE
DOWNFALL IS THE DRY LAYER PRESENT BETWEEN 700MB AND THE SURFACE
WILL PREVENT ANY PRECIP THAT MAY FORM FROM REACHING THE GROUND.
UPPER LEVEL LIFT IMPROVES BEHIND THE FRONT AS A DEEPENING LONG
WAVE TROUGH MOVES IN...BUT SOUNDINGS SHOW THE ENVIRONMENT DRYING
OUT BEHIND THE FRONT. IN ADDITION GEFS AND SREF MEMBERS PLACE THE
PRECIP NORTH OF THE TRI-STATE AREA. WITH UNCERTAINTIES REGARDING THE
AMOUNT OF MOISTURE AVAILABLE WILL ONLY PLACE IN SILENT CHANCES FOR
THE AREA.
FOR THE WEDNESDAY THROUGH SUNDAY PERIOD THE FORECAST WILL CONTINUE
TO BE DRY. THE LONG WAVE TROUGH WILL CONTINUE TO DEEPEN WEDNESDAY
AS IT PROGRESSES EAST...BECOMING A CLOSED LOW OVER THE UPPER
MIDWEST AND LINGERING THERE THROUGH SATURDAY. MEANWHILE NORTHWEST
WINDS WILL STRENGTHEN WEDNESDAY BEHIND THE COLD FRONT FROM TUESDAY
NIGHT. THURSDAY THE WINDS WILL STRENGTHEN FURTHER DUE TO 40-50KT
850MB WINDS WINDS MIXING DOWN. WEDNESDAY AND THURSDAY AFTERNOON
THE FIRE DANGER WILL INCREASE ACROSS THE AREA DUE TO WINDS GUSTING
TO 35 MPH ON WEDNESDAY...45 MPH ON THURSDAY WITH RELATIVE
HUMIDITIES AROUND 20 PERCENT BOTH DAYS. OTHERWISE TEMPERATURES
WILL BE NEAR TO BELOW NORMAL THROUGH FRIDAY THEN ABOVE NORMAL
TEMPERATURES RETURN FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 510 PM MDT SUN OCT 14 2012
VFR CONDITIONS CAN BE EXPECTED AT KGLD AND KMCK DURING THE NEXT 24
HOURS. BREEZY NORTHWEST WIND WILL BECOME LIGHT AND VARIABLE
TONIGHT AS LOW PRESSURE MOVES EAST OF THE MISSOURI RIVER VALLEY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
449 PM MDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW STRONG UPPER LOW CENTERED
ALONG KS/CO BORDER WITH AXIS OF MOISTURE ON BACK SIDE OF UPPER LOW
BEGINNING TO MOVE FROM CENTRAL INTO EASTERN COLORADO. RADAR
CURRENTLY INDICATED SHOWERS/ISOLATED THUNDERSTORMS DEVELOPING OVER
THE WESTERN PART OF OUR CWA ALONG KS/CO STATE LINE. THIS IS AHEAD OF
H7 TROUGH AND ALONG NORTHWESTERN AXIS OF STEEP LAPSE RATES.
LATEST HRRR AND RUC BOTH SHOW SHOWERS AND THUNDERSTORMS CONTINUING
TO DEVELOP EASTWARD ACROSS THE REST OF THE CWA THROUGH THE EARLY
EVENING. THIS ACTIVITY SHOULD DIMINISH AFTER SUNSET AS WE LOOSE THE
STEEP LOW LEVEL LAPSE RATES. WITH SCATTERED COVERAGE...AND LIGHT
NATURE OF MOST OF THIS ACTIVITY...PRECIPITATION SHOULD BE LIGHT.
DESPITE MINIMAL CAPE VALUES IN THE 100-500 J/KG RANGE AND WEAK
0-6KM SHEAR...IT WILL NOT TAKE MUCH TO PRODUCE SEVERE HAIL WITH
-20C HEIGHTS AROUND 15-18KFT ACROSS THE CWA. WITH LOW LCL VALUES
AROUND 1500 KFT AND FAVORABLE AREA BENEATH UPPER LOW WHERE
DIFFERENTIAL HEATING AXIS/SURFACE TROUGH OVERLAP...I CANT RULE OUT
FUNNEL/LANDSPOUT FORMATION WITH THIS ACTIVITY THIS AFTERNOON/EARLY
EVENING. CONSIDERING ABSENCE OF DISTINCT SURFACE BOUNDARY...AND
LOCATION OF BEST SURFACE VORTICITY FURTHER NORTH...THIS THREAT
SEEMS TO BE MINIMAL AT BEST.
THE UPPER LOW WILL SHIFT EAST OF THE CWA BY 06Z TONIGHT...WITH
SHORTWAVE RIDGING AND LARGE SCALE SUBSIDENCE OVERSPREADING THE AREA
BY SUNDAY. WITH SIMILAR H85 TEMPS AND NW WIND PERSISTING...TEMPERATURES
ON SUNDAY SHOULD AT LEAST BE SIMILAR TO THIS AFTERNOON WITH HIGHS
IN THE 70S FOR MOST OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
SUNDAY NIGHT THROUGH MONDAY NIGHT DRY NORTHWEST UPPER LEVEL FLOW
WILL CONTINUE OVER THE AREA. A SHORT WAVE TROUGH MOVES THROUGH THE
FLOW LATE MONDAY NIGHT ACCOMPANYING A SURFACE TROUGH/WEAK COLD
FRONT. POINT SOUNDINGS INDICATE THE UPPER LEVELS MOISTEN AS THE
SHORT WAVE MOVES THROUGH...SO AM ONLY EXPECTING A FEW CLOUDS TO
DEVELOP DURING THE OVERNIGHT HOURS.
TUESDAY THROUGH SATURDAY WILL REMAIN DRY. A COLD FRONT AND UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH WEDNESDAY. BEHIND THE
COLD FRONT WINDS WILL BECOME GUSTY DURING THE AFTERNOON. MOISTURE
WILL REMAIN NORTH OF THE AREA...SO AM NOT ANTICIPATING ANY PRECIP
WITH THE FRONT. THERE MAY BE SOME LIFT FROM THE LEFT EXIT OF THE 500
MB JET...BUT MODELS DISAGREE WITH THE JET PLACEMENT BEHIND THE
FRONT. WITH THE MOISTURE GENERALLY NORTH OF THE AREA AND THE
POSITION OF THE JET IN QUESTION...WILL LEAVE THE FRONTAL PASSAGE DRY.
OTHERWISE TEMPERATURES WILL BE 10 DEGREES ABOVE NORMAL AHEAD THE
COLD FRONT...WITH NEAR NORMAL TEMPERATURES BEHIND THE FRONT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 441 PM MDT SAT OCT 13 2012
SHOWERS AND STORMS CURRENTLY ON RADAR WILL SLOWLY WEAKEN AFTER
SUNSET. THESE HAVE MOVED EAST OF KGLD BUT KMCK WILL CONTIUE TO
HAVE A SLIGHT CHANCE. OTHERWISE, CLOUDS WILL CLEAR OUT OVERNIGHT
WITH VFR CONDITIONS THROUGH THE END OF THIS FORECAST PERIOD.
GUSTY NORTHWEST WIND AND SCATTERED CUMULUS ARE EXPECTED BY MIDDAY
SUNDAY BEHIND THE EXITING LOW PRESSURE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
241 PM MDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW STRONG UPPER LOW CENTERED
ALONG KS/CO BORDER WITH AXIS OF MOISTURE ON BACK SIDE OF UPPER LOW
BEGINNING TO MOVE FROM CENTRAL INTO EASTERN COLORADO. RADAR
CURRENTLY INDICATED SHOWERS/ISOLATED THUNDERSTORMS DEVELOPING OVER
THE WESTERN PART OF OUR CWA ALONG KS/CO STATE LINE. THIS IS AHEAD OF
H7 TROUGH AND ALONG NORTHWESTERN AXIS OF STEEP LAPSE RATES.
LATEST HRRR AND RUC BOTH SHOW SHOWERS AND THUNDERSTORMS CONTINUING
TO DEVELOP EASTWARD ACROSS THE REST OF THE CWA THROUGH THE EARLY
EVENING. THIS ACTIVITY SHOULD DIMINISH AFTER SUNSET AS WE LOOSE THE
STEEP LOW LEVEL LAPSE RATES. WITH SCATTERED COVERAGE...AND LIGHT
NATURE OF MOST OF THIS ACTIVITY...PRECIPITATION SHOULD BE LIGHT.
DESPITE MINIMAL CAPE VALUES IN THE 100-500 J/KG RANGE AND WEAK
0-6KM SHEAR...IT WILL NOT TAKE MUCH TO PRODUCE SEVERE HAIL WITH
-20C HEIGHTS AROUND 15-18KFT ACROSS THE CWA. WITH LOW LCL VALUES
AROUND 1500 KFT AND FAVORABLE AREA BENEATH UPPER LOW WHERE
DIFFERENTIAL HEATING AXIS/SURFACE TROUGH OVERLAP...I CANT RULE OUT
FUNNEL/LANDSPOUT FORMATION WITH THIS ACTIVITY THIS AFTERNOON/EARLY
EVENING. CONSIDERING ABSENCE OF DISTINCT SURFACE BOUNDARY...AND
LOCATION OF BEST SURFACE VORTICITY FURTHER NORTH...THIS THREAT
SEEMS TO BE MINIMAL AT BEST.
THE UPPER LOW WILL SHIFT EAST OF THE CWA BY 06Z TONIGHT...WITH
SHORTWAVE RIDGING AND LARGE SCALE SUBSIDENCE OVERSPREADING THE AREA
BY SUNDAY. WITH SIMILAR H85 TEMPS AND NW WIND PERSISTING...TEMPERATURES
ON SUNDAY SHOULD AT LEAST BE SIMILAR TO THIS AFTERNOON WITH HIGHS
IN THE 70S FOR MOST OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 236 PM MDT SAT OCT 13 2012
SUNDAY NIGHT THROUGH MONDAY NIGHT DRY NORTHWEST UPPER LEVEL FLOW
WILL CONTINUE OVER THE AREA. A SHORT WAVE TROUGH MOVES THROUGH THE
FLOW LATE MONDAY NIGHT ACCOMPANYING A SURFACE TROUGH/WEAK COLD
FRONT. POINT SOUNDINGS INDICATE THE UPPER LEVELS MOISTEN AS THE
SHORT WAVE MOVES THROUGH...SO AM ONLY EXPECTING A FEW CLOUDS TO
DEVELOP DURING THE OVERNIGHT HOURS.
TUESDAY THROUGH SATURDAY WILL REMAIN DRY. A COLD FRONT AND UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH WEDNESDAY. BEHIND THE
COLD FRONT WINDS WILL BECOME GUSTY DURING THE AFTERNOON. MOISTURE
WILL REMAIN NORTH OF THE AREA...SO AM NOT ANTICIPATING ANY PRECIP
WITH THE FRONT. THERE MAY BE SOME LIFT FROM THE LEFT EXIT OF THE 500
MB JET...BUT MODELS DISAGREE WITH THE JET PLACEMENT BEHIND THE
FRONT. WITH THE MOISTURE GENERALLY NORTH OF THE AREA AND THE
POSITION OF THE JET IN QUESTION...WILL LEAVE THE FRONTAL PASSAGE DRY.
OTHERWISE TEMPERATURES WILL BE 10 DEGREES ABOVE NORMAL AHEAD THE
COLD FRONT...WITH NEAR NORMAL TEMPERATURES BEHIND THE FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1127 AM MDT SAT OCT 13 2012
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD AT BOTH
KGLD AND KMCK TERMINALS. GUSTY NORTHWEST WINDS WILL CONTINUE AT
KGLD THROUGH THE EVENING WITH GUSTS UP TO 30KT POSSIBLE. WINDS
WILL BE SLOWER TO INCREASE AT KMCK WITH SURFACE TROUGH IN
PROXIMITY OF TERMINAL...THOUGH GUSTS AROUND 25KT ARE STILL
EXPECTED TO DEVELOP BY SUNRISE. WINDS SHOULD DIMINISH BY 03Z AT
BOTH TERMINALS AS PRESSURE GRADIENT WEAKENS AND MIXING
DIMINISHES. BASED ON UPSTREAM RADAR TRENDS AND 12Z GUIDANCE
CONFIDENCE HAS INCREASED IN SHOWER/ISO THUNDERSTORM POTENTIAL AT
KGLD...THOUGH COVERAGE IS STILL A QUESTION. FOR NOW I HAVE
INTRODUCED A TEMPO GROUP FOR -SHRA DURING THE AFTERNOON PERIOD.
TOO LITTLE CONFIDENCE AT THIS POINT TO INCLUDE MENTION AT KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS WICHITA KS
1250 PM CDT SAT OCT 13 2012
.DISCUSSION...
WARM AIR/MOISTURE ADVECTION WILL KEEP RAIN SHOWERS/THUNDERSTORMS
GOING FOR MOST OF AFTERNOON ALONG/EAST OF I-35. THIS WILL RESULT IN
MAINLY VFR AND BRIEFLY IFR CONDITIONS AT KCNU...AND WILL LIKELY
FLIRT WITH KICT. NAM APPEARS TO BE ON TRACK AND SUGGEST ORGANIZED
STRONG-SEVERE STORMS WILL DEVELOP ALONG DRYLINE THIS AFTERNOON
AND TRAVERSE OVER MOST OF THE AREA LATE THIS AFTERNOON/EARLY
EVENING. DRYLINE MAY BE THROUGH KRSL BEFORE STORMS DEVELOP...BUT
KHUT/KICT/KSLN SHOULD ALL BE IMPACTED. STRONGEST STORMS WOULD BE
AROUND KHUT/KICT WITH G40KT LIKELY AND DECENT THREAT FOR SEVERE
STORMS. DRIER AIR BEHIND FRONT/DRYLINE WILL QUICKLY END PRECIPITATION
AND ERODE LOW CLOUDS WITH GUSTY NORTHWEST WINDS ANTICIPATED FOR
THE REST OF THE PERIOD. -HOWERTON
&&
.PREV DISCUSSION... /ISSUED 657 AM CDT SAT OCT 13 2012/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
WIDESPREAD SHOWERS AND THUNDERSTORMS WERE ONGOING ACROSS MUCH OF
CENTRAL AND SOUTH CENTRAL KANSAS THIS MORNING WITH MVFR
CIGS/VISIBILITIES PREVAILING. THIS ACTIVITY WILL CONTINUE TO DEVELOP AND
MOVE EASTWARD IMPACTING SOUTHEAST KANSAS THROUGH THE MORNING
HOURS. A VIGOROUS STORM SYSTEM OVER THE CENTRAL AND SOUTHERN
ROCKIES WILL MOVE EAST AND THUNDERSTORMS ARE EXPECTED TO REDEVELOP
ALONG A PACIFIC FRONT ACROSS CENTRAL KANSAS THIS AFTERNOON. SEVERE
THUNDERSTORMS WILL LIKELY IMPACT PORTIONS OF CENTRAL AND MUCH OF SOUTH
CENTRAL AND SOUTHEAST KANSAS THIS AFTERNOON AND EVENING BEFORE
DEPARTING EAST DURING THE OVERNIGHT HOURS.
MWM
PREV DISCUSSION... /ISSUED 321 AM CDT SAT OCT 13 2012/
DISCUSSION...
TODAY AND TONIGHT:
ONGOING CONVECTION ACROSS WESTERN KANSAS IS MAKING THE CONVECTIVE
FORECAST FOR LATER TODAY A LITTLE MURKY. SYNOPTIC MODELS DID NOT
HANDLE CONVECTION EVOLUTION DURING THE OVERNIGHT HOURS VERY
WELL...WITH MESO-SCALE MODELS PERFORMING ONLY SLIGHTLY BETTER.
RUC13 APPEARS TO HAVE THE BEST HANDLE ON CONVECTIVE EVOLUTION IN
THE VERY SHORT TERM...THUS WILL USE IT AS A GUIDE AT LEAST THROUGH
THE MORNING HOURS.
AFTER MORNING CONVECTION MOVES EAST OF THE CWA...EXPECT A BRIEF
LULL IN ACTIVITY DUE TO SUBSIDENCE BEHIND MORNING
CONVECTION...BEFORE STORMS RE-FIRE BY EARLY TO MID-AFTERNOON.
TIMING OF WHEN STORMS WILL RE-FIRE AND EXACTLY WHERE STILL IS
UNCLEAR...BUT JUXTAPOSITION OF BEST KINEMATICS AND INSTABILITY
SUGGEST INITIATION SHOULD OCCUR IN THE SOUTHWEST CORNER OF CWA.
FORECAST SOUNDINGS NOT DEPICTING LARGE CAPE VALUES...WITH LARGE
SCALE MOISTURE FLUX LIMITING AMOUNT OF MID-LEVEL DRYING. LARGE
SCALE KINEMATICS SUGGEST CONVECTION WILL BE MAINLY LINEAR IN
NATURE...HOWEVER NAM AND RUC HINT AT A DEVELOPMENT OF MESOLOW
ALONG OR JUST NORTH OF OK-KS BORDER...WHICH COULD INCREASE LOW
LEVEL HELICITY ENOUGH TO ALLOW ISOLATED SUPERCELL TO DEVELOP. FEEL
ANY ISOLATED STORM THAT DEVELOPS WILL NOT LAST TOO LONG...WITH
QLCS BEING THE DOMINATE CONVECTION MODE. BEST POTENTIAL FOR SEVERE
CONVECTION WILL BE DURING THE AFTERNOON INTO EARLY EVENING
HOURS...WITH BULK OF CONVECTION EXITING THE CWA BY MIDNIGHT.
SUN-MON:
LARGE SCALE SUBSIDENCE BEHIND DEPARTING UPPER SYSTEM WILL ALLOW
SKIES TO CLEAR QUICKLY AT LEAST MID-MORNING SUNDAY. WEAK COLD AIR
ADVECTION BEHIND SURFACE COLD FRONT WILL KEEP TEMPERATURES
SLIGHTLY COOLER FOR SUNDAY...ESPECIALLY ACROSS EASTERN PART OF THE
CWA. TEMPERATURES WILL REBOUND ON MONDAY WITH WEAK DOWNSLOPE
WARMING. DRY CONDITIONS ARE EXPECTED.
TUE-THU:
BULK OF THE LONGER RANGE PORTION OF THE FORECAST APPEARS
QUIET. GEFS AND LONGER RANGE OPERATIONAL MODELS SHOWING SOME
DIFFLUENCE IN THE WED-THU TIME FRAME IN THE TIMING OF SHORT WAVE
FEATURE MOVING OUT OF WESTERN CANADA. APPEARS AREA WILL EXPERIENCE
THE PASSAGE OF ANOTHER COLD FRONT BY MID-WEEK...HOWEVER
PRECIPITATION CHANCES IN QUESTION. GULF WILL REMAIN SOMEWHAT
BLOCKED...SO ANY PRECIPITATION WILL BE CONCENTRATED IN PROXIMITY
OF UPPER DYNAMICS...WHICH SHOULD BE FOCUSED NORTH AND EAST OF
FORECAST AREA. HOWEVER...THERMODYNAMIC FORCING MAY ALLOW SCATTERED
CONVECTION TO DEVELOP ALONG FRONT...SO WILL MAINTAIN LOW CHANCE
POPS ACROSS MAINLY EASTERN CWA. TEMPERATURES SHOULD NO DEVIATE TOO
MUCH FROM NORMALS...THUS ACCEPTED GUIDANCE AS A WHOLE.
SF
PREV DISCUSSION... /ISSUED 1156 PM CDT FRI OCT 12 2012/
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE ANTICIPATED UPPER LEVEL LOW IS STILL MAKING ITS WAY INTO THE
HIGH PLAINS...BUT LIFT ASSOCIATED WITH IT IS ALREADY FORMING A
NICE LINE OF STORMS IN WESTERN KANSAS. THE STORY FOR MOST SITES
HAS BEEN IFR CONDITIONS WITH OCCASIONAL MVFR AND/OR LIFR. LOW
VISBYS AND CIGS APPEAR TO BE ON A KINGMAN TO SALINA LINE EXTENDING
TO THE NORTHWEST. BASIC EXPECTED TRENDS ARE FOR BANDS OF SHOWERS
AND THUNDERSTORMS TO PASS OVER THE CENTRAL KANSAS SITES NEAR AND
JUST BEFORE SUNRISE...THEN MOVE SLOWLY TO THE NORTH AND EAST AS
THE SURFACE LOW DEEPENS IN THE LEE OF THE ROCKIES. THIS SURFACE
LOW WILL TIGHTEN UP A DRY LINE AND MOVE EAST...AND DEPENDING ON
THE CLEARING BETWEEN THE MORNING CLOUDS AND PRECIP AND THE DRY
LINE...SHOULD FIRE NEW STORMS LATER SATURDAY AFTERNOON. THE AREAL
EXTENT OF THESE STORMS CAN`T BE PINNED DOWN YET...BUT IS EXPECTED
TO AFFECT ALL SITES EXCEPT FOR CNU...WHICH WILL SEE THE EFFECTS OF
THESE STORMS LATER IN THE EVENING. -LAUGEMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 78 52 77 49 / 70 30 0 0
HUTCHINSON 79 51 78 48 / 60 30 0 0
NEWTON 77 51 77 49 / 60 30 0 0
ELDORADO 76 51 77 49 / 70 40 10 0
WINFIELD-KWLD 78 52 78 50 / 70 40 0 0
RUSSELL 79 48 77 46 / 40 30 0 0
GREAT BEND 80 49 77 47 / 50 20 0 0
SALINA 80 50 77 49 / 60 30 10 0
MCPHERSON 79 50 77 48 / 60 30 0 0
COFFEYVILLE 78 56 79 51 / 80 70 10 0
CHANUTE 76 54 77 50 / 80 70 10 0
IOLA 76 54 76 50 / 80 70 10 0
PARSONS-KPPF 77 54 78 50 / 80 80 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1240 PM CDT SAT OCT 13 2012
...UPDATE TO AVIATION...
.DISCUSSION...
WATER VAPOR IMAGERY SHOWING CENTER OF THE UPPER LOW JUST NORTH OF
THE FOUR CORNERS MOVING EASTWARD AS ANOTHER STRONG SHORTWAVE TROUGH
SWINGS EAST SOUTHEASTWARD AROUND THE SOUTHERN PORTIONS OF THE
TROUGH. CONVECTION HAS CONTINUED TO DEVELOP THROUGH THE NIGHT AHEAD
OF THE MAIN TROUGH THROUGH THE CENTRAL AND SOUTHERN HIGH PLAINS AS
IT MARCHES NORTHEASTWARD AND SLOWLY WEAKENS. MANY OF THE MODELS
ARE NOT HANDLING THIS EXPANSIVE AREA OF CONVECTION AND ITS
MOVEMENT..ALTHOUGH THE RAP IS DOING THE BEST AND INITIALLY HAVE
LEANED WITH ITS GRADUAL EASTWARD MOTION THROUGH THE MORNING WITH
ADDITIONAL DEVELOPMENT OUT AHEAD OF THIS INITIAL CONVECTION ACROSS
MUCH OF THE CENTRAL PORTIONS OF THE CWA THIS MORNING. RECENT RADAR
LOOPS ARE CONFIRMING MORE ELEVATED CONVECTION OUT AHEAD OF THE
LINE AND SOUTHWARD INTO OK. ALSO...NAM AND RECENTLY THE NEW EC
SUGGEST A SLOWER...DEEPER AND FURTHER SOUTH TRACK TO THE UPPER
TROUGH AS IT PROGRESSES ACROSS THE CWA LATE TODAY AND TONIGHT.
THIS COULD RESULT IN A MORE BACKED UPPER FLOW TODAY AND DELAY THE
EASTWARD PROGRESSION OF THIS MORNINGS CONVECTION AND MIDDAY
INSOLATION. ALL IN ALL...THIS COULD CREATE A CHALLENGE IN
FORECASTING THE DEGREE OF INSTABILITY AND RESULTING DEGREE OF THE
SEVERE THUNDERSTORM POTENTIAL ACROSS THE CWA THIS AFTERNOON INTO
THE EVENING. EITHER WAY...ELEVATED SHOWERS AND THUNDERSTORMS WILL
BE PREVALENT THIS MORNING WITH AN "EXPECTED" BREAK IN CONVECTION
BY MIDDAY FOLLOWED BY ADDITIONAL STRONGER DEVELOPMENT AHEAD OF THE
FRONT AND WITHIN INCREASING LARGE SCALE ASCENT AS A JET MAX ROUNDS
THE BASE OF THE UPPER TROUGH AS IT MOVES OUT INTO THE CENTRAL
PLAINS. WITH THE VERY STRONG SHEAR AND CAPE...ANY SUSTAINED
DISCRETE STORMS THAT ARE ABLE TO FORM THIS AFTERNOON MAY BE
CAPABLE OF PRODUCING LARGE HAIL...STRONG WINDS AND POSSIBLY AN
ISOLATED TORNADO PRIMARILY ACROSS NORTHEAST AND EAST CENTRAL AREAS.
HOWEVER...WITH THE ORIENTATION OF LARGE SCALE FORCING AND A MORE
PREDOMINANT UNIDIRECTIONAL FLOW...WOULD EXPECT STORMS TO FORM A
LINE OR LINE SEGMENTS WITH THE MAIN SEVERE POTENTIAL BEING VERY
STRONG STRAIGHTLINE WINDS. AGAIN...DEGREE OF INSTABILITY MAY BE
AFFECTED BY PRECIP COVERAGE AND CLOUD COVER. WITH INCREASING
PRECIPITABLE WATER VALUES APPROACHING AN INCH AND THREE
QUARTERS...LOCALLY HEAVY RAINFALL CAN ALSO BE EXPECTED IN SOME
AREAS. WITH THE SLOWER AND MORE SOUTHWARD TRACK OF THE
TROUGH...HAVE EXTENDED HIGHER POPS BEYOND MIDNIGHT TONIGHT...BUT
STILL ENDED BY SUNRISE ON SUNDAY. LOWERED HIGH TEMPS SLIGHTLY
TODAY THROUGH THE LOWER AND MIDDLE 70S AND AGAIN ON
SUNDAY...ESPECIALLY IN THE FAR EAST.
HAVE MAINTAINED A DRY FCST SUNDAY THROUGH TUESDAY WITH HIGHS IN THE
70S...THEN KEPT THE BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS
CENTERED ON WEDNESDAY AS THE NEXT COLD FRONT AND UPPER TROUGH MOVES
THROUGH THE NORTHERN PLAINS AND MIDWEST. WILL KEEP HIGHS BEHIND THE
FRONT IN THE 60S FOR THURSDAY AND FRIDAY...BUT STILL DRY AS MAIN
TROUGH SETS UP TO THE EAST IN THE MS AND OH RIVER VALLEYS. 63
&&
.AVIATION...
MVFR CEILINGS WILL CONTINUE THROUGH 06Z AT TAF SITES. OCCASIONAL
IFR CONDITIONS WILL BE POSSIBLE DURING PERIODS OF PRECIPITATION.
SCATTERED SHOWERS WILL BE POSSIBLE AT TOP/FOE...WITH THUNDERSTORMS
DEVELOPING AND IMPACTING TAF SITES DURING THE 23Z-04Z WINDOW. A
RETURN TO VFR CONDITIONS WILL BECOME POSSIBLE AFTER 06Z...WITH
CLEARING SKIES BY MID MORNING SUNDAY.
BLAIR
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
657 AM CDT SAT OCT 13 2012
.AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
WIDESPREAD SHOWERS AND THUNDERSTORMS WERE ONGOING ACROSS MUCH OF
CENTRAL AND SOUTH CENTRAL KANSAS THIS MORNING WITH MVFR
CIGS/VISIBILITIES PREVAILING. THIS ACTIVITY WILL CONTINUE TO DEVELOP AND
MOVE EASTWARD IMPACTING SOUTHEAST KANSAS THROUGH THE MORNING
HOURS. A VIGOROUS STORM SYSTEM OVER THE CENTRAL AND SOUTHERN
ROCKIES WILL MOVE EAST AND THUNDERSTORMS ARE EXPECTED TO REDEVELOP
ALONG A PACIFIC FRONT ACROSS CENTRAL KANSAS THIS AFTERNOON. SEVERE
THUNDERSTORMS WILL LIKELY IMPACT PORTIONS OF CENTRAL AND MUCH OF SOUTH
CENTRAL AND SOUTHEAST KANSAS THIS AFTERNOON AND EVENING BEFORE
DEPARTING EAST DURING THE OVERNIGHT HOURS.
MWM
&&
.PREV DISCUSSION... /ISSUED 321 AM CDT SAT OCT 13 2012/
DISCUSSION...
TODAY AND TONIGHT:
ONGOING CONVECTION ACROSS WESTERN KANSAS IS MAKING THE CONVECTIVE
FORECAST FOR LATER TODAY A LITTLE MURKY. SYNOPTIC MODELS DID NOT
HANDLE CONVECTION EVOLUTION DURING THE OVERNIGHT HOURS VERY
WELL...WITH MESO-SCALE MODELS PERFORMING ONLY SLIGHTLY BETTER.
RUC13 APPEARS TO HAVE THE BEST HANDLE ON CONVECTIVE EVOLUTION IN
THE VERY SHORT TERM...THUS WILL USE IT AS A GUIDE AT LEAST THROUGH
THE MORNING HOURS.
AFTER MORNING CONVECTION MOVES EAST OF THE CWA...EXPECT A BRIEF
LULL IN ACTIVITY DUE TO SUBSIDENCE BEHIND MORNING
CONVECTION...BEFORE STORMS RE-FIRE BY EARLY TO MID-AFTERNOON.
TIMING OF WHEN STORMS WILL RE-FIRE AND EXACTLY WHERE STILL IS
UNCLEAR...BUT JUXTAPOSITION OF BEST KINEMATICS AND INSTABILITY
SUGGEST INITIATION SHOULD OCCUR IN THE SOUTHWEST CORNER OF CWA.
FORECAST SOUNDINGS NOT DEPICTING LARGE CAPE VALUES...WITH LARGE
SCALE MOISTURE FLUX LIMITING AMOUNT OF MID-LEVEL DRYING. LARGE
SCALE KINEMATICS SUGGEST CONVECTION WILL BE MAINLY LINEAR IN
NATURE...HOWEVER NAM AND RUC HINT AT A DEVELOPMENT OF MESOLOW
ALONG OR JUST NORTH OF OK-KS BORDER...WHICH COULD INCREASE LOW
LEVEL HELICITY ENOUGH TO ALLOW ISOLATED SUPERCELL TO DEVELOP. FEEL
ANY ISOLATED STORM THAT DEVELOPS WILL NOT LAST TOO LONG...WITH
QLCS BEING THE DOMINATE CONVECTION MODE. BEST POTENTIAL FOR SEVERE
CONVECTION WILL BE DURING THE AFTERNOON INTO EARLY EVENING
HOURS...WITH BULK OF CONVECTION EXITING THE CWA BY MIDNIGHT.
SUN-MON:
LARGE SCALE SUBSIDENCE BEHIND DEPARTING UPPER SYSTEM WILL ALLOW
SKIES TO CLEAR QUICKLY AT LEAST MID-MORNING SUNDAY. WEAK COLD AIR
ADVECTION BEHIND SURFACE COLD FRONT WILL KEEP TEMPERATURES
SLIGHTLY COOLER FOR SUNDAY...ESPECIALLY ACROSS EASTERN PART OF THE
CWA. TEMPERATURES WILL REBOUND ON MONDAY WITH WEAK DOWNSLOPE
WARMING. DRY CONDITIONS ARE EXPECTED.
TUE-THU:
BULK OF THE LONGER RANGE PORTION OF THE FORECAST APPEARS
QUIET. GEFS AND LONGER RANGE OPERATIONAL MODELS SHOWING SOME
DIFFLUENCE IN THE WED-THU TIME FRAME IN THE TIMING OF SHORT WAVE
FEATURE MOVING OUT OF WESTERN CANADA. APPEARS AREA WILL EXPERIENCE
THE PASSAGE OF ANOTHER COLD FRONT BY MID-WEEK...HOWEVER
PRECIPITATION CHANCES IN QUESTION. GULF WILL REMAIN SOMEWHAT
BLOCKED...SO ANY PRECIPITATION WILL BE CONCENTRATED IN PROXIMITY
OF UPPER DYNAMICS...WHICH SHOULD BE FOCUSED NORTH AND EAST OF
FORECAST AREA. HOWEVER...THERMODYNAMIC FORCING MAY ALLOW SCATTERED
CONVECTION TO DEVELOP ALONG FRONT...SO WILL MAINTAIN LOW CHANCE
POPS ACROSS MAINLY EASTERN CWA. TEMPERATURES SHOULD NO DEVIATE TOO
MUCH FROM NORMALS...THUS ACCEPTED GUIDANCE AS A WHOLE.
SF
PREV DISCUSSION... /ISSUED 1156 PM CDT FRI OCT 12 2012/
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE ANTICIPATED UPPER LEVEL LOW IS STILL MAKING ITS WAY INTO THE
HIGH PLAINS...BUT LIFT ASSOCIATED WITH IT IS ALREADY FORMING A
NICE LINE OF STORMS IN WESTERN KANSAS. THE STORY FOR MOST SITES
HAS BEEN IFR CONDITIONS WITH OCCASIONAL MVFR AND/OR LIFR. LOW
VISBYS AND CIGS APPEAR TO BE ON A KINGMAN TO SALINA LINE EXTENDING
TO THE NORTHWEST. BASIC EXPECTED TRENDS ARE FOR BANDS OF SHOWERS
AND THUNDERSTORMS TO PASS OVER THE CENTRAL KANSAS SITES NEAR AND
JUST BEFORE SUNRISE...THEN MOVE SLOWLY TO THE NORTH AND EAST AS
THE SURFACE LOW DEEPENS IN THE LEE OF THE ROCKIES. THIS SURFACE
LOW WILL TIGHTEN UP A DRY LINE AND MOVE EAST...AND DEPENDING ON
THE CLEARING BETWEEN THE MORNING CLOUDS AND PRECIP AND THE DRY
LINE...SHOULD FIRE NEW STORMS LATER SATURDAY AFTERNOON. THE AREAL
EXTENT OF THESE STORMS CAN`T BE PINNED DOWN YET...BUT IS EXPECTED
TO AFFECT ALL SITES EXCEPT FOR CNU...WHICH WILL SEE THE EFFECTS OF
THESE STORMS LATER IN THE EVENING. -LAUGEMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 78 52 77 49 / 70 30 0 0
HUTCHINSON 79 51 78 48 / 60 30 0 0
NEWTON 77 51 77 49 / 60 30 0 0
ELDORADO 76 51 77 49 / 70 40 10 0
WINFIELD-KWLD 78 52 78 50 / 70 40 0 0
RUSSELL 79 48 77 46 / 40 30 0 0
GREAT BEND 80 49 77 47 / 50 20 0 0
SALINA 80 50 77 49 / 60 30 10 0
MCPHERSON 79 50 77 48 / 60 30 0 0
COFFEYVILLE 78 56 79 51 / 80 70 10 0
CHANUTE 76 54 77 50 / 80 70 10 0
IOLA 76 54 76 50 / 80 70 10 0
PARSONS-KPPF 77 54 78 50 / 80 80 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
648 AM CDT SAT OCT 13 2012
...UPDATE TO AVIATION...
.DISCUSSION...
WATER VAPOR IMAGERY SHOWING CENTER OF THE UPPER LOW JUST NORTH OF
THE FOUR CORNERS MOVING EASTWARD AS ANOTHER STRONG SHORTWAVE TROUGH
SWINGS EAST SOUTHEASTWARD AROUND THE SOUTHERN PORTIONS OF THE
TROUGH. CONVECTION HAS CONTINUED TO DEVELOP THROUGH THE NIGHT AHEAD
OF THE MAIN TROUGH THROUGH THE CENTRAL AND SOUTHERN HIGH PLAINS AS
IT MARCHES NORTHEASTWARD AND SLOWLY WEAKENS. MANY OF THE MODELS
ARE NOT HANDLING THIS EXPANSIVE AREA OF CONVECTION AND ITS
MOVEMENT..ALTHOUGH THE RAP IS DOING THE BEST AND INITIALLY HAVE
LEANED WITH ITS GRADUAL EASTWARD MOTION THROUGH THE MORNING WITH
ADDITIONAL DEVELOPMENT OUT AHEAD OF THIS INITIAL CONVECTION ACROSS
MUCH OF THE CENTRAL PORTIONS OF THE CWA THIS MORNING. RECENT RADAR
LOOPS ARE CONFIRMING MORE ELEVATED CONVECTION OUT AHEAD OF THE
LINE AND SOUTHWARD INTO OK. ALSO...NAM AND RECENTLY THE NEW EC
SUGGEST A SLOWER...DEEPER AND FURTHER SOUTH TRACK TO THE UPPER
TROUGH AS IT PROGRESSES ACROSS THE CWA LATE TODAY AND TONIGHT.
THIS COULD RESULT IN A MORE BACKED UPPER FLOW TODAY AND DELAY THE
EASTWARD PROGRESSION OF THIS MORNINGS CONVECTION AND MIDDAY
INSOLATION. ALL IN ALL...THIS COULD CREATE A CHALLENGE IN
FORECASTING THE DEGREE OF INSTABILITY AND RESULTING DEGREE OF THE
SEVERE THUNDERSTORM POTENTIAL ACROSS THE CWA THIS AFTERNOON INTO
THE EVENING. EITHER WAY...ELEVATED SHOWERS AND THUNDERSTORMS WILL
BE PREVALENT THIS MORNING WITH AN "EXPECTED" BREAK IN CONVECTION
BY MIDDAY FOLLOWED BY ADDITIONAL STRONGER DEVELOPMENT AHEAD OF THE
FRONT AND WITHIN INCREASING LARGE SCALE ASCENT AS A JET MAX ROUNDS
THE BASE OF THE UPPER TROUGH AS IT MOVES OUT INTO THE CENTRAL
PLAINS. WITH THE VERY STRONG SHEAR AND CAPE...ANY SUSTAINED
DISCRETE STORMS THAT ARE ABLE TO FORM THIS AFTERNOON MAY BE
CAPABLE OF PRODUCING LARGE HAIL...STRONG WINDS AND POSSIBLY AN
ISOLATED TORNADO PRIMARILY ACROSS NORTHEAST AND EAST CENTRAL AREAS.
HOWEVER...WITH THE ORIENTATION OF LARGE SCALE FORCING AND A MORE
PREDOMINANT UNIDIRECTIONAL FLOW...WOULD EXPECT STORMS TO FORM A
LINE OR LINE SEGMENTS WITH THE MAIN SEVERE POTENTIAL BEING VERY
STRONG STRAIGHTLINE WINDS. AGAIN...DEGREE OF INSTABILITY MAY BE
AFFECTED BY PRECIP COVERAGE AND CLOUD COVER. WITH INCREASING
PRECIPITABLE WATER VALUES APPROACHING AN INCH AND THREE
QUARTERS...LOCALLY HEAVY RAINFALL CAN ALSO BE EXPECTED IN SOME
AREAS. WITH THE SLOWER AND MORE SOUTHWARD TRACK OF THE
TROUGH...HAVE EXTENDED HIGHER POPS BEYOND MIDNIGHT TONIGHT...BUT
STILL ENDED BY SUNRISE ON SUNDAY. LOWERED HIGH TEMPS SLIGHTLY
TODAY THROUGH THE LOWER AND MIDDLE 70S AND AGAIN ON
SUNDAY...ESPECIALLY IN THE FAR EAST.
HAVE MAINTAINED A DRY FCST SUNDAY THROUGH TUESDAY WITH HIGHS IN THE
70S...THEN KEPT THE BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS
CENTERED ON WEDNESDAY AS THE NEXT COLD FRONT AND UPPER TROUGH MOVES
THROUGH THE NORTHERN PLAINS AND MIDWEST. WILL KEEP HIGHS BEHIND THE
FRONT IN THE 60S FOR THURSDAY AND FRIDAY...BUT STILL DRY AS MAIN
TROUGH SETS UP TO THE EAST IN THE MS AND OH RIVER VALLEYS. 63
&&
.AVIATION...
EXPECT IFR TO LOW MVFR CEILINGS THROUGH MUCH OF THE NEXT 24 HOURS.
THERE WILL BE PERIODS OF SHOWERS AND THUNDERSTORMS THROUGH THE
DAY AND INTO THE EVENING. SOME OF THE THUNDERSTORMS LATE THIS
AFTERNOON AND INTO THE EARLY EVENING HOURS MAY CONTAIN GUSTY
WINDS AND QUARTER SIZE HAIL.
GARGAN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
422 AM CDT SAT OCT 13 2012
.DISCUSSION...
WATER VAPOR IMAGERY SHOWING CENTER OF THE UPPER LOW JUST NORTH OF
THE FOUR CORNERS MOVING EASTWARD AS ANOTHER STRONG SHORTWAVE TROUGH
SWINGS EAST SOUTHEASTWARD AROUND THE SOUTHERN PORTIONS OF THE
TROUGH. CONVECTION HAS CONTINUED TO DEVELOP THROUGH THE NIGHT AHEAD
OF THE MAIN TROUGH THROUGH THE CENTRAL AND SOUTHERN HIGH PLAINS AS
IT MARCHES NORTHEASTWARD AND SLOWLY WEAKENS. MANY OF THE MODELS
ARE NOT HANDLING THIS EXPANSIVE AREA OF CONVECTION AND ITS
MOVEMENT..ALTHOUGH THE RAP IS DOING THE BEST AND INITIALLY HAVE
LEANED WITH ITS GRADUAL EASTWARD MOTION THROUGH THE MORNING WITH
ADDITIONAL DEVELOPMENT OUT AHEAD OF THIS INITIAL CONVECTION ACROSS
MUCH OF THE CENTRAL PORTIONS OF THE CWA THIS MORNING. RECENT RADAR
LOOPS ARE CONFIRMING MORE ELEVATED CONVECTION OUT AHEAD OF THE
LINE AND SOUTHWARD INTO OK. ALSO...NAM AND RECENTLY THE NEW EC
SUGGEST A SLOWER...DEEPER AND FURTHER SOUTH TRACK TO THE UPPER
TROUGH AS IT PROGRESSES ACROSS THE CWA LATE TODAY AND TONIGHT.
THIS COULD RESULT IN A MORE BACKED UPPER FLOW TODAY AND DELAY THE
EASTWARD PROGRESSION OF THIS MORNINGS CONVECTION AND MIDDAY
INSOLATION. ALL IN ALL...THIS COULD CREATE A CHALLENGE IN
FORECASTING THE DEGREE OF INSTABILITY AND RESULTING DEGREE OF THE
SEVERE THUNDERSTORM POTENTIAL ACROSS THE CWA THIS AFTERNOON INTO
THE EVENING. EITHER WAY...ELEVATED SHOWERS AND THUNDERSTORMS WILL
BE PREVALENT THIS MORNING WITH AN "EXPECTED" BREAK IN CONVECTION
BY MIDDAY FOLLOWED BY ADDITIONAL STRONGER DEVELOPMENT AHEAD OF THE
FRONT AND WITHIN INCREASING LARGE SCALE ASCENT AS A JET MAX ROUNDS
THE BASE OF THE UPPER TROUGH AS IT MOVES OUT INTO THE CENTRAL
PLAINS. WITH THE VERY STRONG SHEAR AND CAPE...ANY SUSTAINED
DISCRETE STORMS THAT ARE ABLE TO FORM THIS AFTERNOON MAY BE
CAPABLE OF PRODUCING LARGE HAIL...STRONG WINDS AND POSSIBLY AN
ISOLATED TORNADO PRIMARILY ACROSS NORTHEAST AND EAST CENTRAL AREAS.
HOWEVER...WITH THE ORIENTATION OF LARGE SCALE FORCING AND A MORE
PREDOMINANT UNIDIRECTIONAL FLOW...WOULD EXPECT STORMS TO FORM A
LINE OR LINE SEGMENTS WITH THE MAIN SEVERE POTENTIAL BEING VERY
STRONG STRAIGHTLINE WINDS. AGAIN...DEGREE OF INSTABILITY MAY BE
AFFECTED BY PRECIP COVERAGE AND CLOUDCOVER. WITH INCREASING
PRECIPITABLE WATER VALUES APPROACHING AN INCH AND THREE
QUARTERS...LOCALLY HEAVY RAINFALL CAN ALSO BE EXPECTED IN SOME
AREAS. WITH THE SLOWER AND MORE SOUTHWARD TRACK OF THE
TROUGH...HAVE EXTENDED HIGHER POPS BEYOND MIDNIGHT TONIGHT...BUT
STILL ENDED BY SUNRISE ON SUNDAY. LOWERED HIGH TEMPS SLIGHTLY
TODAY THROUGH THE LOWER AND MIDDLE 70S AND AGAIN ON
SUNDAY...ESPECIALLY IN THE FAR EAST.
HAVE MAINTAINED A DRY FCST SUNDAY THROUGH TUESDAY WITH HIGHS IN THE
70S...THEN KEPT THE BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS
CENTERED ON WEDNESDAY AS THE NEXT COLD FRONT AND UPPER TROUGH MOVES
THROUGH THE NORTHERN PLAINS AND MIDWEST. WILL KEEP HIGHS BEHIND THE
FRONT IN THE 60S FOR THURSDAY AND FRIDAY...BUT STILL DRY AS MAIN
TROUGH SETS UP TO THE EAST IN THE MS AND OH RIVER VALLEYS. 63
&&
.AVIATION...
SCATTERED THUNDERSTORMS WILL CONTINUE ON AND OFF THROUGH 09Z
BEFORE BECOMING MORE WIDESPREAD WITH SHOWERS AND THUNDERSTORMS
THROUGH 15Z. ANOTHER ROUND OF THUNDERSTORMS IS EXPECTED AFTER 19Z
AT MHK AND AFTER 21Z AT TOP AND FOE. BY 04Z MOST IF NOT ALL OF THE
CONVECTION SHOULD MOVE EAST OF THE TERMINALS. IFR TO MVFR CIGS AND
VSBYS EXPECTED TO CONTINUE THROUGH MUCH OF THE PERIOD.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
321 AM CDT SAT OCT 13 2012
.DISCUSSION...
TODAY AND TONIGHT:
ONGOING CONVECTION ACROSS WESTERN KANSAS IS MAKING THE CONVECTIVE
FORECAST FOR LATER TODAY A LITTLE MURKY. SYNOPTIC MODELS DID NOT
HANDLE CONVECTION EVOLUTION DURING THE OVERNIGHT HOURS VERY
WELL...WITH MESO-SCALE MODELS PERFORMING ONLY SLIGHTLY BETTER.
RUC13 APPEARS TO HAVE THE BEST HANDLE ON CONVECTIVE EVOLUTION IN
THE VERY SHORT TERM...THUS WILL USE IT AS A GUIDE AT LEAST THROUGH
THE MORNING HOURS.
AFTER MORNING CONVECTION MOVES EAST OF THE CWA...EXPECT A BRIEF
LULL IN ACTIVITY DUE TO SUBSIDENCE BEHIND MORNING
CONVECTION...BEFORE STORMS RE-FIRE BY EARLY TO MID-AFTERNOON.
TIMING OF WHEN STORMS WILL RE-FIRE AND EXACTLY WHERE STILL IS
UNCLEAR...BUT JUXTAPOSITION OF BEST KINEMATICS AND INSTABILITY
SUGGEST INITIATION SHOULD OCCUR IN THE SOUTHWEST CORNER OF CWA.
FORECAST SOUNDINGS NOT DEPICTING LARGE CAPE VALUES...WITH LARGE
SCALE MOISTURE FLUX LIMITING AMOUNT OF MID-LEVEL DRYING. LARGE
SCALE KINEMATICS SUGGEST CONVECTION WILL BE MAINLY LINEAR IN
NATURE...HOWEVER NAM AND RUC HINT AT A DEVELOPMENT OF MESOLOW
ALONG OR JUST NORTH OF OK-KS BORDER...WHICH COULD INCREASE LOW
LEVEL HELICITY ENOUGH TO ALLOW ISOLATED SUPERCELL TO DEVELOP. FEEL
ANY ISOLATED STORM THAT DEVELOPS WILL NOT LAST TOO LONG...WITH
QLCS BEING THE DOMINATE CONVECTION MODE. BEST POTENTIAL FOR SEVERE
CONVECTION WILL BE DURING THE AFTERNOON INTO EARLY EVENING
HOURS...WITH BULK OF CONVECTION EXITING THE CWA BY MIDNIGHT.
SUN-MON:
LARGE SCALE SUBSIDENCE BEHIND DEPARTING UPPER SYSTEM WILL ALLOW
SKIES TO CLEAR QUICKLY AT LEAST MID-MORNING SUNDAY. WEAK COLD AIR
ADVECTION BEHIND SURFACE COLD FRONT WILL KEEP TEMPERATURES
SLIGHTLY COOLER FOR SUNDAY...ESPECIALLY ACROSS EASTERN PART OF THE
CWA. TEMPERATURES WILL REBOUND ON MONDAY WITH WEAK DOWNSLOPE
WARMING. DRY CONDITIONS ARE EXPECTED.
TUE-THU:
BULK OF THE LONGER RANGE PORTION OF THE FORECAST APPEARS
QUIET. GEFS AND LONGER RANGE OPERATIONAL MODELS SHOWING SOME
DIFFLUENCE IN THE WED-THU TIME FRAME IN THE TIMING OF SHORT WAVE
FEATURE MOVING OUT OF WESTERN CANADA. APPEARS AREA WILL EXPERIENCE
THE PASSAGE OF ANOTHER COLD FRONT BY MID-WEEK...HOWEVER
PRECIPITATION CHANCES IN QUESTION. GULF WILL REMAIN SOMEWHAT
BLOCKED...SO ANY PRECIPITATION WILL BE CONCENTRATED IN PROXIMITY
OF UPPER DYNAMICS...WHICH SHOULD BE FOCUSED NORTH AND EAST OF
FORECAST AREA. HOWEVER...THERMODYNAMIC FORCING MAY ALLOW SCATTERED
CONVECTION TO DEVELOP ALONG FRONT...SO WILL MAINTAIN LOW CHANCE
POPS ACROSS MAINLY EASTERN CWA. TEMPERATURES SHOULD NO DEVIATE TOO
MUCH FROM NORMALS...THUS ACCEPTED GUIDANCE AS A WHOLE.
SF
&&
.PREV DISCUSSION... /ISSUED 1156 PM CDT FRI OCT 12 2012/
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE ANTICIPATED UPPER LEVEL LOW IS STILL MAKING ITS WAY INTO THE
HIGH PLAINS...BUT LIFT ASSOCIATED WITH IT IS ALREADY FORMING A
NICE LINE OF STORMS IN WESTERN KANSAS. THE STORY FOR MOST SITES
HAS BEEN IFR CONDITIONS WITH OCCASIONAL MVFR AND/OR LIFR. LOW
VISBYS AND CIGS APPEAR TO BE ON A KINGMAN TO SALINA LINE EXTENDING
TO THE NORTHWEST. BASIC EXPECTED TRENDS ARE FOR BANDS OF SHOWERS
AND THUNDERSTORMS TO PASS OVER THE CENTRAL KANSAS SITES NEAR AND
JUST BEFORE SUNRISE...THEN MOVE SLOWLY TO THE NORTH AND EAST AS
THE SURFACE LOW DEEPENS IN THE LEE OF THE ROCKIES. THIS SURFACE
LOW WILL TIGHTEN UP A DRY LINE AND MOVE EAST...AND DEPENDING ON
THE CLEARING BETWEEN THE MORNING CLOUDS AND PRECIP AND THE DRY
LINE...SHOULD FIRE NEW STORMS LATER SATURDAY AFTERNOON. THE AREAL
EXTENT OF THESE STORMS CAN`T BE PINNED DOWN YET...BUT IS EXPECTED
TO AFFECT ALL SITES EXCEPT FOR CNU...WHICH WILL SEE THE EFFECTS OF
THESE STORMS LATER IN THE EVENING. -LAUGEMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 78 52 77 49 / 70 30 0 0
HUTCHINSON 79 51 78 48 / 60 30 0 0
NEWTON 77 51 77 49 / 60 30 0 0
ELDORADO 76 51 77 49 / 70 40 0 0
WINFIELD-KWLD 78 52 78 50 / 70 40 0 0
RUSSELL 79 48 77 46 / 40 30 0 0
GREAT BEND 80 49 77 47 / 40 20 0 0
SALINA 80 50 77 49 / 60 30 10 0
MCPHERSON 79 50 77 48 / 60 30 0 0
COFFEYVILLE 78 56 79 51 / 80 70 10 0
CHANUTE 76 54 77 50 / 80 70 10 0
IOLA 76 54 76 50 / 80 70 10 0
PARSONS-KPPF 77 54 78 50 / 80 80 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1203 AM MDT SAT OCT 13 2012
.SHORT TERM...(THIS AFTERNOON THROUGH SATURDAY)
ISSUED AT 1245 PM MDT FRI OCT 12 2012
LATEST THINKING IS THERE WILL BE TWO POTENTIAL ROUNDS OF
PRECIPITATION ASSOCIATED WITH THE LARGE UPPER LOW OVER SOUTHERN
NEVADA THAT WILL AFFECT THE REGION IN THE NEXT 18 HOURS. FIRST...A
SHORT WAVE TROUGH CURRENTLY LIFTING NORTHEAST ACROSS THE OKLAHOMA
PANHANDLE WILL INITIATE SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST BETWEEN ABOUT 20Z AND 01Z.
THE NAM SHOWS DECENT ELEVATED CAPE AROUND 1000 J/KG HOWEVER 0-6 KM
BULK SHEAR IS ONLY ABOUT 25 KTS THIS AFTERNOON. SUB-SEVERE HAIL
AND C-G LIGHTNING ARE THOUGHT TO BE THE MAIN THREATS. THIS FIRST
ROUND OF PRECIP SHOULD BEGIN TO WEAK AND LOSE COVERAGE AS THE
UPPER TROUGH LIFTS FURTHER NORTHEAST AFTER 00Z. ONE MODULATING
INFLUENCE THIS AFTERNOON IS POSITION OF 250 MB JET. THE CURRENT
LOCATION PUTS OUR AREA IN THE RIGHT EXIT REGION WHICH MAY EXPLAIN
THE LOOK OF THE HRRR REFLECTIVITY FIELDS LATER THIS AFTERNOON
WITH PRECIPITATION SPLITTING AND WEAKENING.
THE BULK OF THE SYSTEM IS EXPECTED TO APPROACH THE AREA OVERNIGHT...
BUT THINK BETTER CHANCES OF SHOWERS AND THUNDERSTORMS WILL BE IN
THE SOUTHEAST COUNTIES IN THE 06-12Z TIME FRAME. THE NAM SHOWS
SOME CAPE IN THE -10 TO -20 C HAIL GROWTH REGION AT THAT TIME,
PLUS 0-6 KM SHEAR WILL INCREASE TO AROUND 70 KTS INDICATING A FEW
STORMS OVERNIGHT HAVE THE POTENTIAL TO PRODUCE SEVERE HAIL IF
THINGS COME TOGETHER AS PLANNED. ALSO KEPT MENTION OF AREAS OF FOG
OVERNIGHT WITH LOW LEVEL RH VALUES ABOVE 95 PERCENT.
ON SATURDAY...SOMEWHAT LESS CERTAIN REGARDING POTENTIAL FOR
SCATTERED SHOWERS DURING THE AFTERNOON. LAPSE RATES NOT ALL THAT
STEEP AS UPPER SYSTEM MOVES OVERHEAD...AND SUBSIDENCE BEHIND UPPER
TROUGH WITH RIDGING MOVING IN WILL COINCIDE WITH PEAK HEATING. KEPT
SLIGHT CHANCES FOR SHOWERS GOING FOR NOW BUT CONFIDENCE IS NOT THAT
HIGH FOR DECENT COVERAGE IF LATEST NAM-GFS VERIFY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 240 PM MDT FRI OCT 12 2012
THE CLOSED LOW THAT BROUGHT PRECIP WILL EXIT THE AREA EARLY SATURDAY
EVENING. MODELS PLACE PRECIP WELL WEST OF THE LOW WHERE A SHORT
WAVE RIDGE WILL BE. AM THINKING IF ANY PRECIP WILL DEVELOP IT
WILL BE JUST BEHIND THE CLOSED LOW. AM NOT TOO CONFIDENT THERE
WILL BE ANY PRECIP ACCOMPANYING THE CLOSED LOW AS IT MOVES EAST
DUE TO 700-500MB LAPSE RATES LESS THAN 6C/KM. HOWEVER WITH MODELS
SHOWING PRECIP FOLLOWING THE CLOSED LOW...WILL KEEP THE MENTION OF
SLIGHT CHANCES GOING DURING THE EARLY EVENING AS THE LOW EXITS THE
AREA.
SUNDAY AND SUNDAY NIGHT AN UPPER LEVEL RIDGE WILL BUILD OVER THE
INTERMOUNTAIN WEST...EXTENDING OVER THE TRI-STATE AREA. A MINOR
SHORT WAVE TROUGH WILL MOVE THROUGH THE FLOW OVER THE NORTHEAST PART
OF THE AREA. HOWEVER WITH LITTLE MOISTURE TO WORK WITH...AM NOT
EXPECTING ANYTHING MORE THAN A FEW CLOUDS TO DEVELOP. BEHIND THE
SHORT WAVE TROUGH WINDS WILL INCREASE DURING THE AFTERNOON...WITH
GUSTS NEAR 30MPH AS STRONG WINDS ABOVE THE SURFACE MIX DOWN.
TEMPERATURES FOR SATURDAY THROUGH SUNDAY NIGHT WILL BE NEAR NORMAL.
FOR MONDAY THROUGH FRIDAY THE PERIOD WILL BE PRIMARILY DRY. TUESDAY
AND WEDNESDAY A SHORT WAVE TROUGH MOVES THROUGH THE FLOW OVER THE
AREA...WITH A COLD FRONT FOLLOWING THE FIRST SHORT WAVE TUESDAY
NIGHT. THERE IS SOME MOISTURE TO WORK WITH...SO HAVE INCLUDED
SLIGHT CHANCES FOR THE FAR NORTHEAST PART OF THE AREA TUESDAY
NIGHT. ANOTHER STRONGER COLD FRONT MOVES THROUGH WEDNESDAY NIGHT.
THERE IS LESS MODEL AGREEMENT WITH PRECIP DEVELOPING AS THE SECOND
COLD FRONT MOVES THROUGH...SO WILL CONTINUE WITH THE DRY FORECAST.
TEMPERATURES THROUGH THIS PERIOD WILL BE ABOVE NORMAL PRIOR TO THE
FIRST COLD FRONT THEN NEAR NORMAL THROUGH THE REST OF THE WEEK
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1111 PM MDT FRI OCT 12 2012
THE AREA OF SHOWERS HAS MOVED THROUGH THE MAJORITY OF THE
FORECAST AREA THIS EVENING WITH SHOWERS AND THUNDERSTORMS
EXTENDING FROM SOUTH CENTRAL NEBRASKA TO SOUTHWEST KANSAS. THE
MAIN UPPER LOW CENTER IS STILL OVER WESTERN COLORADO AT 06Z AND
WILL CONTINUE TO MOVE EAST OF THE ROCKIES OVERNIGHT WITH SHOWERS
AND THUNDERSTORMS MOVING OUT OF THE AREA AND SURFACE TROUGH AND
FRONTAL BOUNDARY MOVING ACROSS THE AREA BETWEEN 12Z-15Z THIS
MORNING. HAVE MENTIONED SHOWERS IN THE VICINITY OF KMCK AT THE
BEGINNING OF THE TAF PERIOD WITH A POSSIBILITY OF MVFR CONDITIONS
DUE TO LOWER CEILINGS...OTHERWISE CONDITIONS WILL CONTINUE TO BE
VFR. AS THE FRONT MOVES ACROSS THE TAF SITES EARLY THIS
MORNING...WINDS ARE EXPECTED TO TURN FROM THE SOUTH TO THE
NORTHWEST. WINDS WILL ALSO REMAIN GUSTY THROUGH THE DAY AS CLOUDS
THIN THROUGH THE DAY IN THE SUBSIDENT AREA ON THE BACK SIDE OF THE
EXITING LOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DLF
LONG TERM...JTL
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
957 PM EDT SUN OCT 14 2012
.SYNOPSIS...
AN EASTBOUND COLD FRONT WILL PROVIDE SCATTERED SHOWERS AND GUSTY
WINDS INTO MONDAY AS TEMPERATURES DROP TO SLIGHTLY COOLER THAN
NORMAL.
&&
.NEAR TERM /THROUGH MONDAY/...
JUDGING FROM RECENT RADAR AND SURFACE DATA...ALONG WITH RECENT
RAP...WRF-NMM...AND NAM MODEL OUTPUT...CONTINUE TO EXPECT BANDS OF
SCATTERED SHOWERS WITH GUSTY WINDS AT TIMES OVERNIGHT...DUE TO THE
PASSAGE OF AN EASTBOUND COLD FRONT AROUND MIDNIGHT.
CONCUR WITH RECENT RADAR AND SURFACE DATA ALONG WITH NAM MODEL
PROFILES...WRF-NMM AND RAP MODEL OUTPUT... WINDS CAN GUST TO
40 MPH...PARTICULARLY IN WAKE OF SHOWERS AND THE COLD FRONTAL
PASSAGE AROUND MIDNIGHT. FASTEST WIND GUSTS SHOULD BE ACROSS
NORTHERN TIER OF OHIO AND NORTHWEST PENNSYLVANIA COUNTIES...FROM
NEW PHILADELPHIA OH TO FRANKLIN PA.
EXPECT LATE NIGHT TEMPERATURES TO DROP INTO THE 50 TO 55 RANGE IN
THE WAKE OF COLD FRONTAL PASSAGE. ENSUING COLD UPPER TROUGH WITH
H8 TEMPERATURES NEAR 0C...SHOULD KEEP CLOUD COVER AND SHOWER
CHANCES THROUGH MONDAY EVENING. SO TEMPERATURES DAYTIME MONDAY
WILL BE SLIGHTLY COOLER THAN NORMAL WITH MOST HIGHS IN THE MID TO
UPPER 50S.
NAM MODEL PROFILES SHOW SURFACE WINDS CAN GUST TO 30 TO 35 MPH.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
EASTBOUND HIGH PRESSURE WILL HELP TO BACK WIND INTO THE WEST AND
LIKEWISE DRY OUT LOWER LEVELS LATE MONDAY NIGHT AND TUESDAY. THIS
WILL PROMOTE DRY AND RELATIVELY CLOUD FREE CONDITIONS INTO WEDNESDAY.
HIGH CLOUDS WITH THE APPROACH OF THE NEXT LOW PRESSURE SYSTEM
COULD REACH THE OHIO VALLEY BY LATER WEDNESDAY.
USING BLEND OF MODEL GUIDANCE...FORECASTED TEMPERATURES TO BE
SLIGHTLY COOLER THAN NORMAL MONDAY NIGHT AND TUESDAY...THEN NEAR
NORMAL TUESDAY NIGHT AND SEVERAL DEGREES WARMER THAN NORMAL
DAYTIME WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MODELS ARE NOW SLOWER WITH APPROACHING COLD FRONT AND DEVELOPING
CLOSED LOW ACROSS THE WESTERN LAKES MID WEEK. SO HAVE SLOWED POP
INCREASE FOR A DRY FORECAST WEDNESDAY NIGHT...THEN INCREASED RAIN
CHANCES THURSDAY AS FRONT APPROACHES.
SHOWERS WILL REMAIN THROUGH THE WEEKEND...CLOSER TO ECMWF
SOLUTION WHICH IS CLOSER TO BLEND USED FOR HPC GRIDS. THIS
SOLUTION TAKES THE CLOSED UPPER LOW SLOWLY EAST FROM THE GREAT
LAKES TO THE OHIO VALLEY THROUGH THE EXTENDED PERIOD. TEMPERATURES
WILL BE NEAR TO ABOVE NORMAL UNTIL SATURDAY AND SUNDAY...WHEN
COOLER TEMPERATURES UNDER CLOSED LOW WILL ARRIVE.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
PER LATEST MODEL DATA...OBS...SAT AND RADAR DATA. WILL CONTINUE WITH
A PRE-FRONTAL VFR FORECAST WITH GUSTY SOUTHERLY WINDS. FRONT NOW
CROSSING ZZV...WILL CROSS PIT AROUND 05Z...AND DUJ AROUND 07Z.
WILL INTRODUCE MVFR CIGS WITH NON-RESTRICTIVE SHOWERS TO ALL PORTS AT
FRONTAL PASSAGE. GUSTS MAY REACH 30 KTS AT KFKL.
LATEST MODEL DATA IS SHOWING MVFR CIGS HOLDING THROUGH DAWN. GUSTY
WINDS WILL BEGIN TO WANE LATE TONIGHT. IMPROVEMENT TO VFR
CONDITIONS AT ALL PORTS EXCEPT FKL AND DUJ SHORTLY AFTER DAWN.
WESTERLY WINDS WILL STRENGTHEN BY LATE MORNING WITH GUSTS TO 20KTS
POSSIBLE.
.OUTLOOK.../MONDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL PROVIDE GENERAL VFR TUESDAY AND WEDNESDAY. AN
APPROACHING FRONT MAY BRING RESTRICTIONS LATER THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
742 PM EDT SUN OCT 14 2012
.UPDATE...
ISSUED AT 625 PM EDT SUN OCT 14 2012
DID AN EARLY UPDATE THIS EVENING TO ACCOUNT FOR A MORE EXTENSIVE
PERIOD OF RAIN ACROSS THE EASTERN HALF OF THE FORECAST AREA. THE LOW
OVER NRN MICHIGAN WILL BE SLOW TO MOVE NORTHEAST TONIGHT AS THE
UPPER TROUGH BECOMES NEGATIVELY TILTED. THIS WILL ALLOW FOR
DEEPENING TO CONTINUE THIS EVENING WITH A TROWAL TYPE FEATURE
EVENTUALLY DEVELOPING AS THE LOW OCCLUDES OUT. THIS TROWAL WILL HELP
TO STRENGTHEN THE FRONTOGENETIC FORCING TO THE NORTHWEST OF THE LOW
AND ALLOW FOR PCPN TO PERSIST FOR MUCH OF THE OVERNIGHT ACROSS THE
EASTERN 1/3 OF UPPER MICHIGAN. THE LATEST RAP RUN CLEARLY SHOWS PCPN
HANGING ON FOR MUCH OF THE NIGHT AT ERY. MEANWHILE...NORTH CENTRAL
UPPER MICHIGAN IS SEEING THE TERRAIN LIGHT UP DUE TO THE DEEPER
MOISTURE AND SLIGHTLY MORE NORTHERLY PBL FLOW. WITH ALL OF THIS
SAID...HAVE OPTED TO RAISE POPS TO CATEGORICAL THIS EVENING ACROSS
N-CENTRAL UPPER MICHIGAN AND THEN GRADUALLY DIMINISH OVERNIGHT AS
DRIER AIR MOVES IN. WILL ALSO MAINTAIN CATEGORICAL POPS ALL NIGHT
ACROSS THE EAST. SOME PLACES ACROSS THE EASTERN HALF OF UPPER MI
WILL SEE OVER 2 INCHES OF RAIN BY MONDAY MORNING. MANY PLACES ARE
ALREADY WELL OVER 1 INCH TODAY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 351 PM EDT SUN OCT 14 2012
CURRENT /18Z/ ANALYSIS SHOWS A STRONG UPPER SHORTWAVE TROUGH
STRETCHING FROM N MN TO N IL...WITH AN ELONGATED 998MB SFC LOW FROM
N IL TO NE LOWER MI. THE NE PORTION OF THE SFC LOW SHOULD BEGIN TO
DOMINATE AS THE DRY SLOT IS MOVING OVER REDUCING STATIC
STABILITY...AND SINCE THE UPPER SHORTWAVE FOCUS OVER THIS
AREA...FAVORING CYCLOGENESIS. THE 850MB LOW IS JUST SE OF
MENOMINEE...WITH A LARGE SHIELD OF MODERATE TO HEAVY RAINFALL ON THE
NW SIDE OF THIS FEATURE. THE NW EXTENT OF THE RAIN SHIELD EXTENDS
FROM NEAR ARX...TO RHI...TO CRYSTAL FALLS...TO MQT...TO E LAKE
SUPERIOR. AS NOTED BEFORE...HEAVY RAIN HAS BEEN REPORTED...MAINLY
CLOSER TO LAKE MICHIGAN WITH RAIN AMOUNTS UP TO AN INCH SO FAR OVER
SCENTRAL UPPER M. ADDITIONALLY...UPSLOPE FLOW AND AMPLE LOW LEVEL
MOISTURE IS BRINGING DRIZZLE/BR AND RAIN SHOWERS TO MUCH OF THE REST
OF THE CWA. ON THE NW SIDE OF THE SYSTEM IS A SFC RIDGE THAT WILL
MOVE INTO THE CWA TOMORROW.
THE DEFORMATION/FGEN FORCING AXIS AND ASSOCIATED PRECIP IS NOT
EXPECTED TO MOVE MUCH MORE NW THAN WHAT IT IS NOW SINCE IT IS
PIVOTING AROUND THE 850MB LOW...AND IS ALREADY STARTING TO PUSH
SLOWLY E ALONG THE WI BORDER. AS THE UPPER SHORTWAVE MOVES TO THE
ERN CWA BY 06Z MON...THE SFC LOW WILL MOVE TO LAKE HURON AND THE
BAND OF SYNOPTIC PRECIP WILL MOVE TO THE FAR ERN CWA OR JUST E OF
THE CWA. AS MODERATELY COLD 850MB TEMPS OF -2C TO -4C MOVES OVER
LAKE SUPERIOR BY 06Z MON...EXPECT SOME ISOLATED TO SCATTERED LAKE
EFFECT RAIN SHOWERS AND DRIZZLE FROM THE NLY UPSLOPE FLOW. BY TIME
THE COLDER AIR MOVES INTO THE NEAR SFC LAYER...LOW LOW LEVEL
MOISTURE WILL BE PRESENT...SO NOW SNOW IS EXPECTED. THE LAKE EFFECT
PRECIP WILL TAPER OFF FROM W TO E AS DRIER LOW LEVEL AIR MOVES IN
WITH THE SFC RIDGE. THE RIDGE WILL MOVE TO NEAR IWD BY 18Z
MON...THEN TO THE CENTER OF THE CWA BY 00Z TUE...BRINGING A RETURN
OF WARMER 850MB TEMPS UP TO 4C.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 449 PM EDT SUN OCT 14 2012
MONDAY NIGHT INTO TUE...MDLS WERE IN REASONABLE AGREEMENT WITH THE
MID LEVEL AND SFC RIDGE SLIDING QUICKLY TO THE EAST AND A MAINLY
ZONAL PATTERN ACROSS THE NRN CONUS. WAA/ISENTROPIC LIFT AHEAD OF THE
NEXT SHORTWAVE TROUGH WILL BRING INCREASING CLOUDS ACROSS THE AREA
MON NIGHT WITH RAIN CHANCES SPREADING INTO WRN UPPER MI. MODERATE TO
STRONG 300K ASCENT WITH MOISTURE INFLOW BRINGING PWAT VALUES TO
AROUND AN INCH SUPPORT LIKELY POPS OVER MOST OF THE CWA...ESPECIALLY
FOR THE CNTRL AND EAST EVEN IF QPF VALUES ARE ONLY A TENTH OF TWO.
EXPECT THAT THE PCPN WILL TAPER OFF IN THE WEST HALF BY AFTERNOON
AND THE EAST LATE.
TUE NIGHT AND WED...MDLS SUGGEST THAT AS STRONG UPPER LEVEL JET
ENERGY INTO THE PAC NW DIGS TO THE SE A BROAD MID/UPPER LEVEL TROUGH
WILL DEVELOP OVER THE PLAINS. WAA WILL INCREASE AHEAD OF A SFC
TROUGH EXTENDED FROM SRN MANITOBA INTO WRN MN BY 12Z/WED. THE ECMWF
WAS PREFERRED WITH A SLIGHTLY LATER ARRIVAL OF ANY PCPN INTO UPPER
MI AS THE STRONGER FORCING WITH THE JET AND MID LEVEL LOW REMAIN TO
THE SW OF UPPER MI. EVEN THOUGH 850 MB TEMPS CLIMB TO AROUND
10C...INCREASING CLOUDS SHOULD LIMIT MAX READINGS TO AROUND 60.
THU-SUN...MDLS DIFFERENCES BECOME MORE SIGNFICANT AS THE GFS/GEFS
BECOME MORE PROGRESSIVE BY NEXT WEEKEND COMPARED TO THE 00Z ECMWF
AND ASSOCIATED ENSEMBLES. EVEN THOUGH THE 12Z ECMWF HAS TRENDED MORE
TOWARD THE GFS...CONFIDENCE IN THE OVERALL PATTERN AND DETAILS IS
LOW. EXPECT THE BEST CHANCE OF PCPN FROM WED NIGHT INTO THU AS THE
SFC TROUGH AND MOISTURE AXIS LIFTS INTO THE REGION. BEYOND THU...THE
POSITION OF THE DRY SLOT OR ADDITIONAL WEAK IMPULSES AROUND THE MID
LEVEL LOW IS VERY UNCERTAIN. ABOVE NORMAL TEMPS WILL COOL BACK AGAIN
AOB SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 736 PM EDT SUN OCT 14 2012
RAIN WILL CONTINUE TONIGHT ACROSS THE EASTERN HALF OF THE FORECAST
AREA AS LOW PRESSURE OVER NRN LAKE MICHIGAN SLOWLY MOVES NORTHEAST.
NORTHERLY WINDS ACROSS THE AREA OFF OF LAKE SUPERIOR WILL ALLOW FOR
IFR CONDITIONS TO PERSIST FOR MUCH OF THE NIGHT AT THE
TERMINALS...ALTHOUGH CONDITIONS WILL IMPROVE LATER TONIGHT AS DRIER
AIR MOVES INTO THE AREA. WORST CONDITIONS WILL LIKELY BE AT SAW
WHERE LIFR CONDITIONS ARE POSSIBLE ESPECIALLY THIS EVENING. MVFR TO
VFR CONDITIONS AT ALL SITES ON MONDAY. IN ADDITION...NORTH WINDS
WILL GUST TO 30 KT AT TIMES TONIGHT AT SAW...AND TO 20 KT AT CMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 301 PM EDT SUN OCT 14 2012
EXPECT N TO NE WINDS TO INCREASE INTO TONIGHT AS A LOW PRESSURE
SYSTEM OVER NORTHERN LAKE MICHIGAN LIFTS NE TO LAKE HURON BY LATE
TONIGHT. LATE THIS AFTERNOON AND EARLY EVENING...WINDS SHOULD BE IN
THE 20-30KT RANGE OVER PRIMARILY THE CENTRAL AND ERN PORTIONS OF
LAKE SUPERIOR. WINDS WILL BE LIGHTER OVER THE FAR WRN LAKE. EXPECT
NORTHERLY GALES TO DEVELOP OVER ROUGHLY THE EASTERN HALF OF LAKE
SUPERIOR LATE THIS EVENING AND THEN CONTINUE INTO MONDAY MORNING AS
THE LOW RAPIDLY DEEPENS AND MOVES EAST OF THE AREA AND HIGH PRESSURE
PUSHES IN FROM THE WEST. WINDS SETTLE DOWN MONDAY AFTERNOON AND
MONDAY NIGHT WITH ARRIVAL OF HIGH PRESSURE. ANOTHER LOW PRESSURE
SYSTEM WILL MOVE INTO THE UPPER GREAT LAKES ON WEDNESDAY INTO
WEDNESDAY NIGHT. SOUTH WINDS AHEAD OF THIS LOW COULD BRIEFLY REACH
GALES TO 35 KTS OVER ERN LAKE SUPERIOR TUE AFTERNOON.
OTHERWISE...WINDS IN THE VICINITY OF THE LOW SHOULD REMAIN LESS THAN
20 KTS WEDNESDAY THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EDT MONDAY FOR LSZ249>251-266-267.
LAKE MICHIGAN...
GALE WARNING UNTIL 11 AM EDT MONDAY FOR LMZ221-250.
&&
$$
UPDATE...MRD
SHORT TERM...TITUS
LONG TERM...JLB
AVIATION...MRD
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 PM EDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 423 PM EDT SAT OCT 13 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A ZONALLY ORIENTED FLOW
ACROSS SRN CANADA AND THE FAR NRN CONUS. TO THE S...A SHORTWAVE TROF
IS EMERGING FROM CO/NM INTO THE WRN PLAINS. DEEP/MOIST SW FLOW
DOWNSTREAM OF THE TROF HAS GENERATED SEVERAL AREAS OF SHRA AND SOME
TSRA FROM THE SRN PLAINS TO THE GREAT LAKES. WITH THE MORE ZONALLY
ORIENTED FLOW ACROSS THE FAR NRN CONUS...THE AREAS OF SHRA HAVE BEEN
TENDING TO SHIFT MORE EASTWARD THE FARTHER N THEY SPREAD. AS A
RESULT...THERE HAS BEEN LITTLE PCPN OVER THE NW HALF OF THE FCST
AREA TODAY (MUCH OF THE PCPN HAS BEEN DRIZZLE) WHILE THE SE HALF HAS
BEEN GETTING BRUSHED BY SHRA.
PCPN TRENDS/COVERAGE WILL BE THE MAIN FCST ISSUES IN THE SHORT TERM.
FLOW ACROSS SRN CANADA/FAR NRN CONUS IS EXPECTED TO BUCKLE AS HEIGHT
RISES OVER WRN NAMERICA FORCE DOWNSTREAM HEIGHT FALLS INTO
MISSISSIPPI VALLEY REGION. THIS WILL HELP TO PICK UP/LIFT THE WRN
PLAINS SHORTWAVE TO THE NE. EXACTLY HOW FAR N IT LIFTS WILL BE
IMPORTANT TO THE PCPN FCST TONIGHT/SUN. EVEN AT THIS SHORT TIME
RANGE INTO MODEL RUNS...THERE ARE STILL IMPORTANT DIFFERENCES IN THE
MODELS. THE NAM REMAINS MOST SUPPRESSED WITH THE LOW TRACK THOUGH IT
HAS TRENDED SLIGHTLY N...AND IT IS SUPPORTED BY OUR LOCAL REG WRF
RUN AND THE NCEP HIGH RES WRF-ARW AND WRF-NMN. THEY ALL KEEP THE
MAIN PCPN SHIELD ALMOST ENTIRELY SE OF FCST AREA SUN. THE 12Z GFS
HAS TRENDED S AND ONLY BRINGS PCPN SHIELD INTO THE SE FCST AREA. THE
UKMET/REGIONAL GEM PUSH PCPN SHIELD A LITTLE FARTHER N AND W. THE 12Z
ECMWF HAS ALSO TRENDED SLIGHTLY S. GIVEN OVERALL TRENDS AND A
MAJORITY SHOWING A LESS AGGRESSIVE MOISTURE PUSH INTO UPPER MI
SUN...FCST WILL FOLLOW SUIT AND SHOW HIGHER POPS SHIFTED MORE TO THE
S AND E.
CURRENT PUSH OF SHRA ENE THRU WI INTO SRN UPPER MI IS ASSOCIATED
WITH A SURGE OF 850-700MB MOISTURE TRANSPORT AND ISENTROPIC ASCENT
ON THE 305K SFC. WITH THAT MOISTURE TRANSPORT/ASCENT QUICKLY
SHIFTING E THIS EVENING...AND THEN RATHER MEAGER FORCING LEFT BEHIND
FOR THE NIGHT...IT APPEARS THERE WON`T BE MUCH IN THE WAY OF
RAINFALL FOR THE BULK OF TONIGHT AS WE AWAIT THE MAIN PIECE OF
ENERGY TO TRACK INTO THE GREAT LAKES SUN. WITH WINDS BECOMING LIGHT
UPSLOPE OFF LAKE SUPERIOR DURING THE NIGHT...-DZ THAT HAS BEEN
OCCURRING TODAY WILL LIKELY CONTINUE TONIGHT...ESPECIALLY ACROSS THE
NCNTRL.
SHORTWAVE LIFTS INTO THE GREAT LAKES SUN AFTN WITH ASSOCIATED SFC
LOW TRACKING TOWARD NRN LWR MI. AS A RESULT...RAIN WILL SPREAD BACK
TO THE N...BUT AS DISCUSSED ABOVE...LOWERED POPS FROM PREVIOUS FCST.
KEPT CATEGORICAL POPS ONLY ALONG LAKE MICHIGAN INTO THE FAR ERN FCST
AREA WITH POPS DROPPING OFF SHARPLY TO CHC JUST TO THE NW. MAY SEE A
LITTLE LAKE ENHANCED SHRA ACTIVITY IN THE NNE/NE WIND FAVORED
LOCATIONS...SO SHRA CHANCES IN THOSE AREAS WILL BE A LITTLE HIGHER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 423 PM EDT SAT OCT 13 2012
A FAIRLY STRONG UPPER SHORTWAVE TROUGH WILL BE OVER THE CENTRAL CWA
AT 00Z MON...DEEPENING AS IT MOVES TO THE FAR ERN CWA BY 06Z MON DUE
TO A WEAK SHORTWAVE PHASING WITH THE SYSTEM. AT THE SFC...A ROUGHLY
995MB LOW WILL BE OVER OVER NRN LOWER MI AT 00Z MON...MOVING TO
GEORGIAN BAY BY 06Z MON. THE 850MB LOW WILL BE JUST E OF DRUMMOND
ISLAND AT 00Z MON...WITH A NICE DEFORMATION PRECIP BAND JUST ON THE
LEFT SIDE OF THE 850MB LOW TRACK AS IT MOVES NE. THERE SHOULD BE A
PRETTY SHARP CUT OFF BETWEEN THE DEFORMATION BAND AND LITTLE TO NO
SYNOPTIC RAIN...AND AFTER 00Z SUN...THE CWA SHOULD BE ON THE DRIER
SIDE OF THAT CUT OFF. HOWEVER...WITH THE SHORTWAVE DEEPENING
OVERHEAD THEN MOVING E...COLDER 850MB TEMPS WILL FILTER IN FROM THE
NNW. WITH THE NNW LOW LEVEL WINDS AND 850MB TEMPS OF -3C TO
-4C...SOME LIGHT LAKE EFFECT RAIN /MIXING WITH SNOW OVER THE HIGHER
TERRAIN/ WILL LINGER INTO MONDAY MORNING OVER NCENTRAL AND ERN UPPER
MI.
A SFC RIDGE WILL MOVE OVER MON AFTERNOON AND EVENING...BRINGING A
BRIEF DRY PERIOD BEFORE A SHORTWAVE TROUGH AND ASSOCIATED WARM FRONT
MOVE INTO THE CWA. PRECIP CHANCES MOVE BACK IN WITH THIS SYSTEM
AFTER MIDNIGHT MON NIGHT...WITH AT LEAST SLIGHT CHANCE POPS OVER
PARTS OF THE CWA UNTIL MORE PRECIP ARRIVES WITH A LOW PRESSURE
SYSTEM MOVING IN FROM THE W ON WED. HIGHS ON MON LOOK TO BE IN THE
UPPER 40S TO MID 50...WITH WARMER TEMPS ON TUE IN THE 50S. WED LOOKS
TO CONTINUE THE WARM TREND WITH HIGHS AGAIN IN THE 50S. OVERALL GOOD
CONFIDENCE INTO WED.
CONFIDENCE DECREASES AS THE NEXT SYSTEM MOVES IN WED INTO THE END OF
NEXT WEEK SINCE MODELS GENERALLY SHOW THE SAME IDEA OF THE LOW
CLOSING OFF ON THU AND LINGERING SOMEWHERE OVER/NEAR THE REGION
THROUGH THE END OF THE WEEK. HOWEVER...MODELS SHOW SIGNIFICANTLY
VARYING SOLUTIONS WITH WHERE TO HAVE THE LOW...WHICH CAUSES WIDELY
DIFFERENT PRECIP/WIND SCENARIOS. EVEN WITH THE DIFFERENCES...WILL
HAVE CHANCES OF PRECIP FOR THE REST OF THE PERIOD LATE WED THROUGH
SAT...DERIVED FROM CONSENSUS OF MODELS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 130 PM EDT SAT OCT 13 2012
LOW PRES OVER THE PLAINS WILL MOVE NORTHEAST TOWARD THE WRN GREAT
LAKES DURING THE FCST PERIOD. ABUNDANT MOISTURE STREAMING N AHEAD OF
SYSTEM HAS RESULTED IN WIDESPREAD MOSTLY IFR CONDITIONS ACROSS WI
INTO UPPER MI. WHILE A DOWNSLOPE SOUTHERLY WIND MAY SUPPORT BRIEF
VFR CONDITIONS AT KIWD THIS AFTN...EXPECT MVFR CONDITIONS TO
PREVAIL. MAY SEE A PERIOD OF IFR CONDITIONS/-DZ LATER TONIGHT AS NNE
WINDS STRENGTHEN ACROSS LAKE SUPERIOR. AT KCMX...LIFR/IFR CONDITIONS
SHOULD GENERALLY PREVAIL INTO THE EVENING HRS. ADVECTION OF SLIGHTLY
DRIER AIR AND A SLIGHT DOWNSLOPE COMPONENT TO THE WIND LATER
TONIGHT/SUN MORNING SHOULD HELP CIGS RISE TO MVFR. AT KSAW...IFR
CONDITIONS MAY RISE TO LOW MVFR LATE THIS AFTN/EVENING AS WINDS
SHIFT TO A LIGHT DOWNSLOPE DIRECTION. LIFR CONDITIONS EXPECTED LATER
TONIGHT/SUN MORNING AS UPSLOPE NNE WINDS STRENGTHEN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 423 PM EDT SAT OCT 13 2012
WINDS ARE IN THE PROCESS OF DIMINISHING ACROSS LAKE SUPERIOR AS LOW
PRES TROF/WEAKER PRES GRADIENT SHIFT OVER THE AREA. LATER TONIGHT
AND INTO SUN...N TO NE WINDS WILL INCREASE AS LOW PRES MOVES NE
TOWARD NRN LWR MICHIGAN. DURING SUN AFTN...WINDS SHOULD BE IN THE
20-30KT RANGE OVER THE CNTRL AND ERN PORTIONS OF LAKE SUPERIOR.
WINDS WILL BE LIGHTER OVER THE FAR W. SOME NORTHERLY GALE GUSTS OVER
EASTERN LAKE SUPERIOR ARE POSSIBLE INTO SUNDAY NIGHT AS THE LOW
MOVES EAST OF THE AREA AND HIGH PRESSURE PUSHES IN FROM THE WEST.
WINDS SETTLE DOWN MONDAY AND MONDAY NIGHT WITH ARRIVAL OF HIGH
PRESSURE. ANOTHER LOW PRESSURE WILL MOVE INTO THE UPPER GREAT LAKES
ON WEDNESDAY. SOUTH WINDS COULD PUSH UP TO 25 KTS AHEAD OF THE LOW
ON TUESDAY...MAINLY FOR EASTERN SECTIONS. OTHERWISE...WINDS IN THE
VICINITY OF THE LOW SHOULD REMAIN LESS THAN 20 KTS WEDNESDAY INTO
THURSDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON/TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
155 AM EDT SAT OCT 13 2012
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 406 PM EDT FRI OCT 12 2012
WV IMAGERY AND RUC ANALYSIS INDICATED MAINLY ZONAL NRN STREAM
MID/UPPER LEVEL FLOW ACROSS THE NRN CONUS INTO THE WRN GREAT LAKES.
A VIGOROUS SRN STREAM LOW WAS LOCATED OVER NW AZ. AT THE SFC...SRLY
WINDS WERE INCREASING FROM THE PLAINS INTO THE UPPER MS VALLEY BTWN
HIGH PRES OVER LOWER MI AND A TROUGH DEVELOPING OVER THE WRN PLAINS.
VIS LOOP SHOWED DIURNAL CLOUDS OVER CNTRL UPPER MI THINNING AND
SHIFTING TO THE EAST AS SW WINDS DEVELOP. ANY LEFTOVER LAKE EFFECT
PCPN OVER ERN LAKE SUPERIOR HAD DISSIPATED
AS THE SFC HIGH SHIFTS TOWARD THE MID ATLANTIC STATES AND THE
SHRTWV/SFC LOW LIFTS OUT OF THE CENTRAL ROCKIES INTO THE PLAINS...A
STRENGTHENING SW FLOW WILL DEVELOP OVER THE WESTERN GREAT LAKES
TONIGHT. WITH STRONG WAA AND MOISTURE ADVECTION DEVELOPING WITH
MODERATE TO STRONG 295K-305K ISENTROPIC LIFT...RAIN WILL QUICKLY
DEVELOP AND SPREAD TO THE NORTHWEST. HOWEVER...WITH CONVECTION
LIKELY TO DEVELOP CLOSER TO THE SFC-850 MB WARM FRONT...MOISTURE
ADVECTION INTO UPPER MI MAY BE REDUCED. SO...THE NAM/ECMWF WHICH
INDICATES A SLIGHTLY LATER ARRIVAL(BTWN 09Z-12Z)OF THE PCPN WITH THE
HEAVIER PCPN MAINLY SOUTH OF UPPER MI WAS PREFERRED. EXPECT THE
STRONGER ISENTROPIC LIFT TO DIMINISH AND SHIFT TO THE EAST
DURING THE AFTERNOON AS THE SFC-850 MB WARM FRONT MOVES INTO NRN
LAKE MI AND NRN LWR MI. LIKELY TO CATEGORICAL POPS ARE STILL
WARRANTED ACROSS MUCH OF THE FCST AREA EVEN FOR PCPN AMOUNTS LESS
THAN 0.10 NORTHWEST...0.10 TO 0.25 INCH CNTRL TO NEAR 0.50 INCH EAST
AND FAR SOUTH.
INCREASING CLOUDS AND WIND WILL LIMIT THE DIURNAL FALL OF TEMP...AND
FCST THERMAL PROFILES INDICATE ANY PCPN SHOULD BE IN THE FORM OF
RAIN EVEN THOUGH TEMPS AT SOME OF THE INTERIOR COLD SPOTS MIGHT FALL
AOB 32 EARLY THIS EVENING BEFORE THE THICKER CLOUDS ARRIVE. EVEN
WITH THE STRONG WAA...PCPN AND CLOUDS WILL LIMIT HIGHS TO THE MID
AND UPPER 40S SATURDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 406 PM EDT FRI OCT 12 2012
MOST ATTENTION IN LONG TERM ON SAT NIGHT THROUGH SUN WITH A SYSTEM
THAT MAY BRING A COUPLE INCHES OF RAIN TO PARTS OF THE REGION. THERE
IS SOME UNCERTAINTY WITH THIS SYSTEM DUE TO MODEL DISAGREEMENT.
DIFFERENCES BETWEEN MODELS INITIALLY ARE DUE TO DIFFERENCES IN UPPER
LEVEL MASS FIELDS AS A 250MB LOW MOVES FROM THE CURRENT POSITION
OVER SRN NV...TO WRN KS AS A SHORTWAVE TROUGH AT THE START OF THE
PERIOD 00Z SUN. AT 00Z SUN...THE 00Z/12 ECMWF IS ABOUT 50-60M DEEPER
AND ALSO MORE NEUTRALLY TILTED WITH 250MB HEIGHT TROUGH THAN THE
POSITIVELY TILTED GFS. THE 12Z/12 NAM IS AN OUTLIER THROUGH THE
PERIOD AS WAS RULES OUT. THE REG-GEM IS MORE OF A MIDDLE GROUND
SOLUTION THROUGH MUCH OF THE EVENT.. THE DIFFERENCES BETWEEN MODELS
CONTINUES AT 12Z SUN...WHEN THE GFS BECOMES NEUTRALLY TILED OVER THE
WRN MO BORDER WHILE THE ECMWF IS STRONGER...FASTER AND NEGATIVELY
TILTED WITH THE UPPER TROUGH OVER IA/NRN MO. EVENTUAL SFC LOW TRACK
DIFFERENCES ARE NOT DIFFERENT...ALTHOUGH THERE ARE STILL DIFFERENCES
IN SFC LOW STRENGTH...BUT SOME OF THE LARGER DIFFERENCES WITH PRECIP
AMOUNTS/PLACEMENT COME AROUND 850MB. WHILE THE STRONGER ECMWF
DEEPENS THE SYSTEM AND BRINGS A STRENGTHENING 850MB LOW FROM NE IA
12Z SUN TO NEAR THE STRAITS OF MACKINAW AROUND 00Z MON...THE GFS
BRINGS THE 850MB LOW FROM NRN LAKE SUPERIOR AT 00Z SUN TO NEAR THE
STRAITS AT 18Z SUN...THEN DEEPENS IT RAPIDLY OVER LAKE HURON BY 00Z
MON AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED AND UPPER JETS
PHASE. WILL BE INTERESTED TO SEE WHAT THE 12Z/12 ECMWF COMES IN
WITH...BECAUSE THE GFS AND GEM HAVE BEEN TRENDING WEAKER /TOWARD
WHAT THEY HAVE NOW/ OVER THE LAST FEW RUNS. THE MAIN IMPACT FROM THE
WEAKER SCENARIO IS THAT THE STRONG DEFORMATION/FGEN ON THE LEFT SIDE
OF THE 850MB LOW TRACK ARE DISPLACES SE OF THE CWA...WHILE THE ECMWF
SOLUTION BRINGS A COUPLE OF INCHES OF RAIN SAT NIGHT INTO SUN.
OVERALL THINK THE BEST CHANCES OF PRECIP WILL BE OVER THE SERN CWA
CLOSER TO LAKE MICHIGAN...BOTH SAT NIGHT WITH THE WARM FRONT THAT
WILL BE JUST S OF THE CWA AND AS THE LOW PASSES SUN. WILL SHIFT POPS
SE FROM WHAT IS CURRENTLY IN THE FORECAST.
LINGERED SOME SLIGHT CHANCE POPS OVER NORTH CENTRAL AND E UPPER MI
INTO EARLY MON AS N WINDS OFF LAKE SUPERIOR MAY BRING IN SOME LAKE
EFFECT/UPSLOPE PRECIP WHILE 850MB TEMPS DECREASE TO AROUND -3C. ANY
PRECIP WILL BE LIGHT...AND SOME SOME LIGHT SNOW MAY MIX IN OVER THE
HIGHER TERRAIN LATE SUN NIGHT/EARLY MON MORNING. AS SFC RIDGE SLIDES
ACROSS THE CWA MON AFTERNOON/EVENING AHEAD OF AN UPPER RIDGE THAT
WILL MOVE OVERHEAD TUE NIGHT INTO EARLY TUE.
AFTER MON THERE IS CONSIDERABLE MODEL DISAGREEMENT...LIMITED
CONFIDENCE IN THE FORECAST...ESPECIALLY POPS. HOWEVER...IT DOES
APPEAR MORE CERTAIN THAT TUE AND WED WILL BE WARMER WITH HIGHS
GENERALLY IN THE 50S. USED CONSENSUS OF MODELS FOR MON NIGHT THROUGH
FRI.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 152 AM EDT SAT OCT 13 2012
VFR CONDITIONS WILL CONTINUE INTO LATE TONIGHT. A STRENGTHENING SSW
FLOW OVERNIGHT BTWN THE DEPARTING HIGH AND LOW PRESSURE TAKING SHAPE
IN THE PLAINS WILL RESULT IN SOME MARGINAL LLWS AS WELL AS
INCREASING CLOUDS. ENOUGH MOISTURE MAY ARRIVE LATE IN THE FCST
PERIOD TO CAUSE MVFR CIGS CLOSER TO THE WI BORDER AT IWD. STRONGER
MOISTURE INFLOW AHEAD OF WARM FRONT OVER WI WILL BRING LOWER CIGS
INTO THE MVFR RANGE AT ALL SITES LATER TODAY. SRLY LOW LEVEL FLOW
FAVORS EVEN LOWER CIGS INTO THE IFR RANGE AT SAW. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EDT FRI OCT 12 2012
A STEADY SSW WIND UP TO 25 KTS WILL PREVAIL TONIGHT BETWEEN THE
DEPARTING HI AND DEVELOPING LO PRES IN THE PLAINS. AS THE LO PRES
CENTER MOVES TO THE E JUST S OF UPPER MI EARLY SUN...LOOK FOR THE
WINDS TO BACK TO THE N AND INCREASE UP TO 25 TO 30 KTS...ESPECIALLY
OVER THE E HALF. MAY SEE A FEW GALE FORCE GUSTS OVER PORTIONS OF
EASTERN LAKE SUPERIOR SUN. THE APPROACH OF HIGH PRES ON MON WILL CAUSE
A STEADY DECREASE IN WIND SPEED LATER SUN INTO MON. SOUTH WINDS WILL
INCREASE TO 25 KTS OVER MAINLY THE ERN HALF OF THE LAKE ON TUESDAY
AHEAD OF A LOW PRESSURE SYSTEM DEVELOPING OVER THE NRN PLAINS.
&&
.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...UPDATED
NWS JACKSON MS
929 PM CDT SUN OCT 14 2012
.UPDATE...A FRONTAL SYSTEM CURRENTLY PUSHING THROUGH THE AREA WILL
BRING SOME SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE OVERNIGHT
HOURS. A FEW STRONG STORMS CANNOT BE RULED OUT. THE CURRENT FORECAST
IS ON TRACK...WITH ONLY MINOR ADJUSTMENTS TO THE HOURLY TEMPS AND
DEWPTS TO ACCOUNT FOR THE LATEST TRENDS. THE UPDATED AVIATION
DISCUSSION IS BELOW. /27/
&&
.AVIATION...CONVECTION WILL CONTINUE TO BE POSSIBLE ALONG A COLD FRONT
THAT WILL MOVE ACROSS THE AREA TONIGHT. EXPECT VFR CONDITIONS
OUTSIDE OF ANY TSTM ACTIVITY. THE COLD FRONT WILL PASS THROUGH THE
ENTIRE AREA BY DAYBREAK MONDAY AND EXPECT VFR CONDITIONS WILL
PREVAIL FOR THE ENTIRE AREA THROUGH MONDAY NIGHT AS HIGH PRESSURE
AND DRIER AIR BRINGS CLEAR SKIES. /17/
&&
.PREV DISCUSSION... /ISSUED 420 PM CDT SUN OCT 14 2012/
SHORT TERM...
SHOWERS/THUNDERSTORM ACTIVITY ASSOCIATED WITH THE PREFRONTAL TROUGH
HAS ALL BUT DIMINISHED ACROSS THE ARKLAMISS THIS AFTERNOON LEAVING
JUST A FEW LIGHT SHOWERS PASSING OVER AREAS S OF THE NATCHEZ TRACE.
CLEARING CLOUD COVER ACROSS THE DELTA/NE LA HAS ALLOWED HEATING TO
WARM TEMPS INTO THE UPPER 70S/LOWER 80S ACCOMPANIED BY DEW POINTS IN
THE UPPER 60S/NEAR 70. LATEST RUC ANALYSIS SHOWS UNCAPPED SBCAPE
VALUES HAVE CLIMBED ABOVE 1500J/KG ACROSS THESE AREAS JUST AHEAD OF
THE COLD FRONT. FORCING ASSOCIATED WITH THE LEFT EXIT REGION OF A
STRENGTHENING UPPER JET STREAK NOSING IN FROM THE WEST WILL BEGIN TO
OVERSPREAD THESE UNSTABLE AREAS OVER THE NEXT 2 TO 3 HOURS AND WOULD
NOT BE SURPRISED IF AT LEAST A COUPLE STORMS DEVELOPED ALONG THE
FRONT AS WE HEAD INTO EVENING. DEEP LAYER SHEAR OF ~30KTS REMAINS
SUFFICIENT YET MARGINAL FOR SEVERE STORMS SO THE SEVERE WEATHER RISK
WITH ANY OF THIS ACTIVITY IS NOT A SLAM DUNK...BUT IS NOT OUT OF THE
QUESTION. WIND GUSTS WILL BE THE PRIMARY RISK IF ANYTHING CAN GET
GOING...BUT A TORNADO ISN`T COMPLETELY OUT OF THE QUESTION AS LOW
LEVEL SHEAR IN EXCESS OF 20KTS REMAINS ACROSS THIS REGION. WILL KEEP
THESE RISKS MENTIONED IN THE HWO THROUGH THE EVENING.
THE CONVECTIVE POTENTIAL HEADED INTO THE LATTER PART OF THE EVENING
WILL MOST LIKELY BE DOMINATED BY WHAT CAN GET GOING THROUGH EARLY
EVENING. IF STORMS DEVELOP THEN A FEW MAY PERSIST AND PUSH SE TOWARD
THE NATCHEZ TRACE CORRIDOR AS THE STRONG LIFT PUSHES IN...BUT IF
NOTHING DEVELOPS WE MAY NOT SEE MUCH PERSIST PAST 8 OR 9 PM. GIVEN
THE STRENGTH OF THE FORCING...ITS PLAUSIBLE WE COULD SEE ISOLATED
SHOWERS AHEAD OF THE FRONT THROUGH MOST OF THE NIGHT REGARDLESS.
HIGH PRESSURE IN WAKE OF THE FRONT WILL OVERSPREAD THE REGION
TOMORROW KEEPING THINGS DRY THROUGH THE MIDDLE OF THE WEEK. TEMPS
THROUGH THIS TIME WILL BE MUCH MORE SEASONAL ALTHOUGH HIGHS WILL
STILL BE COMING IN A TAD ABOVE NORMAL. RELEVANT SECTIONS OF THE
PREVIOUS LONGER TERM DISCUSSION HAVE BEEN APPENDED BELOW. /BK/
LONG TERM...
BY WED...A VIGOROUS H5 S/WV TROUGH WILL PIVOT INTO THE CNTRL PLAINS.
DEEP SFC CYCLOGENESIS IS PROGGED TO OCCUR WITH A SUB 995MB SFC LOW
ACROSS MID/UPPER MS VALLEY THAT WILL BRING A POTENT COLD FRONT
TOWARDS THE REGION. AHEAD OF THE FRONT...PWATS WILL SURGE FROM S/SW
FLOW LATE WED/ERLY THURS TO NEAR 1.6-1.8" AS SFC DEWPOINTS CLIMB BACK
INTO THE LOW 60S.
ATTM...TIMING OF FROPA IS THURS MRNG PER 00Z EC/GFS WITH LOW
INSTABILITY BUT MODEST KINEMATICS. WILL HAVE TO KEEP WATCH OF THIS
SYSTEM IF SLOWER TIMING /AS 12Z ECMWF HINTED AT/ RESULTS IN GREATER
CONVECTIVE POTENTIAL IF FROPA OCCURS THURS AFTN. INCREASED POPS
ABOVE MEXMOS TOWARDS ECMEX VALUES THURS MRNG FOR NW AREAS WITH
DECREASING RAIN CHANCES BY THURS AFTN/NGT FROM NW TO SE. EC/GFS ARE
AT ODDS WITH DEGREE OF CAA AS EC KEEPS COOLER H85 TEMPS N/W OF
REGION WHILE GFS BARRELS SINGLE DIGIT H85 TEMPS ACROSS NRN ARKLAMISS
FRIDAY. HAVE FAVORED GFS GIVEN CONTINUED MEAN ENSEMBLE SUPPORT WITH
MEAN H5 TROUGH AXIS PLACEMENT JUXTAPOSED TO EC`S LONG RANGE H5
OMEGA BLOCK PATTERN. HIGHS FRI/SAT LOOK TO RANGE FROM NEAR 70 NORTH
TO MID 70S SOUTH WITH A SLIGHT WARM UP INTO SUNDAY WITH PROGGED
AMPLE SUNSHINE POST FROPA. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 57 79 49 78 / 23 0 0 5
MERIDIAN 59 80 45 77 / 23 0 0 3
VICKSBURG 53 80 46 78 / 27 0 0 5
HATTIESBURG 65 82 49 79 / 22 0 0 11
NATCHEZ 57 78 49 77 / 24 0 0 5
GREENVILLE 52 77 50 79 / 30 0 0 3
GREENWOOD 51 77 47 79 / 31 0 0 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
27/17/BK/ALLEN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
318 PM CDT SAT OCT 13 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
MUCH WARMER AND MOISTER AIR HAS REACHED THE REGION AHEAD OF AN
ADVANCING UPPER-LEVEL LOW. SUBJECTIVE 12Z UPPER AIR ANALYSIS
INDICATES OPENING UPPER LOW CENTERED IN SOUTHERN CO...WITH 500MB
HEIGHT FALLS UP TO 90M IN EASTERN CO INDICATING THE WAVE IS EJECTING
INTO THE CENTRAL PLAINS. CORE OF UPPER-LEVEL JET EXTENDED FROM GULF
OF CA THROUGH WESTERN KS/NEB AND INTO CENTRAL MN...WITH STRONGER
NORTHERN STREAM JET STREAK NOSING INTO THE PACIFIC NORTHWEST. AHEAD
OF THE UPPER LOW...850MB MOISTURE HAD SPREAD NORTHWARD FROM OK/TX
INTO NEB/IA...WITH 850MB WINDS UP TO 50-60KT IN EASTERN KS/EASTERN
NEB. SURFACE LOW AT 19Z WAS CENTERED IN NORTH CENTRAL NEB...WITH
COLD FRONT LAGGING FROM SOUTHWEST NEB THROUGH WESTERN KS TO THE
OK/TX PANHANDLES. SURFACE DEWPOINTS IN EASTERN NEB/WESTERN IA ALONG
AND SOUTH OF I-80 WERE IN THE 60S.
MAIN FORECAST CONCERN IS CONVECTIVE POTENTIAL THIS EVENING...WITH
RAIN LINGERING INTO TONIGHT IN THE SOUTHEASTERN CWA. THOUGH UPPER-
LEVEL WAVE IS OPENING...IT REMAINS POTENT. RAP ANALYSIS INDICATES
MLCAPE OF 1000+ J/KG REACHING SOUTH CENTRAL NEB. DEEP-LAYER
EFFECTIVE BULK SHEAR CERTAINLY IS POTENT...AT OR ABOVE 40KT ACROSS
MOST OF SOUTHEAST NEB/SOUTHWEST IA. INTERMITTENT CLOUDS HAVE BEEN
IN PLACE ALL ACROSS THE AREA...BUT ENOUGH SUN IS BREAKING THROUGH TO
ALLOW SOME HEATING AND DESTABILIZATION. THINK CONVECTION COULD
DEVELOP IN CENTRAL KS IN THE LATE AFTN...THEN MOVE NORTHEASTWARD
INTO SOUTHEAST NEB AND EVENTUALLY SOUTHEAST IA THROUGH THE EVENING
HOURS. DO THINK THAT STORMS THAT MOVE INTO THE AREA COULD CARRY A
RISK OF HAIL...AND ALSO WIND...ESPECIALLY AS THEY ORGANIZE INTO A
LINE LATER THIS EVENING AHEAD OF THE FRONT...AS ORIENTATION OF SHEAR
VECTOR IS NEARLY PARALLEL TO FRONTAL FORCING. DO THINK TORNADO
POTENTIAL IS LIMITED BY VEERED SURFACE WIND PROFILE. STORMS SHOULD
PROGRESS ACROSS THE AREA THROUGH THE EVENING HOURS. ECMWF CONTINUES
TO HOLD ONTO A DEFORMATION-ZONE AREA OF RAIN BEHIND THE UPPER-
LOW...WITH A STRONGER LOW THAN NAM/GFS/GEM/UKMET. HELD ONTO A
SHOWER MENTION LATE TONIGHT IN THE SOUTHEAST CWA AS A NOD TO THE
STRONGER ECMWF SOLUTION.
UPPER-LEVEL SYSTEM LACKS ANY KIND OF COLD AIR PUSH BEHIND IT...AND
MILD TEMPERATURES WILL CONTINUE INTO THE WORK WEEK. TEMPS SHOULD
PEAK ON MONDAY UNDER WARM AIR ADVECTION AND LOW-LEVEL
SOUTH/SOUTHWESTERLY FLOW...WITH HIGHS LIKELY TO CRACK 80 IN PARTS OF
EASTERN NEB. A WEAK FRONTAL PASSAGE ASSOCIATED WITH A WEAK UPPER-
LEVEL WAVE WILL SKIRT THROUGH THE AREA ON TUESDAY...BRINGING MAYBE A
FEW EXTRA CLOUDS AND A SLIGHT DIP IN TEMPERATURES TO LESS ABOVE-
NORMAL READINGS.
MAYES
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
GLOBAL MODELS ARE IN BETTER AGREEMENT TODAY IN THE LARGE SCALE FLOW
ACROSS THE CONUS FOR THE SECOND HALF OF THE WORK WEEK. MOST
OPERATIONAL AND ENSEMBLES MODELS NOW AMPLIFY A STRONG SHORTWAVE
TROUGH DIVING INTO THE CNTRL US ON WED. THIS DRIVES A STRONG COLD
FRONT THROUGH THE FA ON WED. WE WILL CONT WITH THE CHC OF SHOWERS
FOR LATE TUE NIGHT IN THE NORTH...SPREADING ACROSS A GOOD PART OF
OUR FA FOR WED. WE MAY SEE THE SHOWERS SHUT OFF FOR A TIME ON WED
NIGHT AS THE MID LEVEL DRY-SLOT WORKS THROUGH THE FORECAST AREA. BUT
THE WRAP-AROUND/DEFORMATION ZONE LOOKS TO IMPACT AT LEAST OUR
NORTHERN AND ERN FA THU AND THU NIGHT WITH CHC POPS IN THE FORECAST.
IT APPEARS THEN THAT THIS PERIOD OF THE FORECAST WILL SEE WELL BELOW
NORMAL TEMPERATURES FOR HIGHS...ESPECIALLY ON THU WHERE HIGHS MAY
NOT GET OUT OF THE MID 40S WITH BREEZY CONDITIONS. WILL LEAVE THE
LATER HALF OF FRI AND INTO SAT DRY ATTM WITH SOME MODERATION TO
TEMPERATURES.
BOUSTEAD
&&
.AVIATION...
18Z TAFS FOR KOFK...KLNK AND KOMA.
A TRICKY AND MESSY TAF FORECAST TO DEAL WITH AT ALL THREE TAF
SITES THIS PACKAGE. EAST NEBRASKA AND WEST IOWA IS BETWEEN A WARM
FRONT THAT LIFTED NORTH ACROSS THE AREA THIS MORNING...AND AN
APPROACHING COLD FRONT FROM THE WEST THAT WILL IMPACT TAF SITES
AROUND 00Z TO 03Z. UNTIL THE FRONT ARRIVES WILL BE JUMPING IN AND
OUT OF MVFR CIGS. WHEN THE FRONT ARRIVES IT WILL BRING A CHANCE OF
THUNDERSTORMS. EXPECT MOST TSRA ACTIVITY TO CLEAR THE AREA AFTER
03Z WITH TREND TO MVFR AND VFR THROUGH THE REMAINDER OF THE
FORECAST.
MEYER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
655 PM EDT SAT OCT 13 2012
.SYNOPSIS...
CLOUDS WILL CONTINUE TO THICKEN OVER THE AREA THROUGH LATE EVENING
WITH RAIN DEVELOPING...FIRST ACROSS NEW YORK STATE AND EVENTUALLY
INTO NORTHERN PENNSYLVANIA AFTER MIDNIGHT. RAIN WILL REMAIN LIKELY
OVERNIGHT AS A WARM FRONT MOVES THROUGH. BEHIND THE WARM FRONT A
FEW SHOWERS WILL BE POSSIBLE ACROSS CENTRAL NEW YORK
SUNDAY...OTHERWISE IT WILL BE BREEZY AND WARM WITH HIGHS NEAR 70.
A COLD FRONT WILL CROSS THE REGION MONDAY WITH SHOWERS ALONG WITH
A RETURN TO COOLER WEATHER.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RADARS SHOW LIGHT RETURNS ACROSS MUCH OF NORTHERN NEW YORK IN
RESPONSE TO INCREASING ISENTROPIC LIFT AND MOISTURE ADVECTION.
MUCH OF THIS WAS VIRGA AT PRESENT. THIS ISEN LIFT/MOISTURE
ADVECTION WAS IN ADVANCE OF A SHORT WAVE RIPPLING THROUGH NORTHERN
ONTARIO. THIS FEATURE WAS INCREASING UPPER CONFLUENCE TO OUR
NORTHEAST ENHANCING THE THERMALLY DIRECT JET STREAK CIRCULATION
FOR NY AND PA. THIS WAS ALLOWING FOR THE STRGR ISEN LIFT AND
PRECIPITATION TO BREAK OUT. BY AROUND 9Z...THIS WAVE PASSES AND THE
WAA IMPULSE WILL WEAKEN AND THE MORE WIDESPREAD RAINS WILL TAPER
TO SCATTERED SHOWERS/SPRINKLES. THIS OCCURS AT THE SAME TIME THAT
THE STRONGER UPPER LEVEL LOW AND ASSOCIATED SURFACE CYCLONE IN THE
PLAINS INTENSIFIES AND INCREASES THE DOWNSTREAM RIDGING ALOFT
OVER THE EAST. THIS WILL ALLOW THE WARM FRONT TO EVENTUALLY PUSH
NORTH OF THE REGION SUNDAY LATER IN THE MORNING AS THE ISENTROPES
WILL EASILY BE ADVECTED NORTH AND NOT BE HELD UP BY A JET STREAK
AND ASSOCIATED GEOSTROPHIC ADJUSTMENTS.
LATEST HRRR HAD THE BEST HANDLE ON THE RADAR ECHOES AT THIS TIME IN
OHIO WHICH WAS MUCH FARTHER SOUTH THAN THE NAM...GFS...AND OTHER
CONVECTION ALLOWING HIGH RES MODELS. SINCE THIS MODEL SEEMS TO HAVE
INITIALIZED WELL AND THE PRECIP IS FARTHER S...I WENT ALONG WITH
THE IDEA OF HAVING MORE PRECIP SLIDE ACROSS NRN PA IN LINE WITH
THE LATEST HRRR LATER TONIGHT. I RAISED POPS IN NE PA FOR LATER TONIGHT
AS A RESULT. OTHERWISE JUST SOME TWEAKS TO AN EXCELLENT FORECAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
330 PM UPDATE...
STRONGEST LIFT MOVES NORTHEAST AS A WARM FRONT LIFTS INTO NNY SUNDAY.
WILL DECREASE POPS FROM SOUTHWEST TO NORTHEAST EARLY...AND
MAINTAIN CHANCE POPS THROUGH THE AFTERNOON ONLY ACROSS NORTHERN
ONEIDA COUNTY. WE WILL REMAIN BREEZY THROUGH EARLY
AFTERNOON...AGAIN WITH THE HIGHER WINDS OVER THE HIGHEST TERRAIN.
WE LOOK FAIRLY DRY THROUGH SUNDAY NIGHT WITH POPS INCREASING
TOWARD DAYBREAK MONDAY AS A COLD FRONT ENTERS THE WESTERN PART OF
THE CWA.
NOT OVERLY IMPRESSED WITH THE FRONTAL PASSAGE MONDAY AND WILL KEEP
POPS IN THE CHANCE RANGE. BY AFTERNOON MOST OF THE CWA SHOULD BE
DRY WITH THE EXCEPTION OF THE FAR SOUTHEAST AS SOME MOISTURE MOVES
UP THE COAST. A TROF MOVES THROUGH MONDAY NIGHT WITH A FEW
SHOWERS. WITH 850S IN THE 0C TO -2C RANGE TUESDAY ON A NORTHWEST
FLOW LAKE SHOWERS WILL BE AROUND BUT STRONG NVA ON THE BACKSIDE OF
THE UPPER TROF WILL LIMIT THE POTENTIAL TO JUST SLIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
330 PM UPDATE...
MAIN FEATURE OF NOTE TO WATCH DURING THIS EXTENDED PERIOD WILL BE AN
UPPER LEVEL CLOSED LOW MOVING SLOWLY EAST FROM THE MIDWEST. MODEL
TRENDS HAVE BEEN TO SLOW THIS FEATURE DOWN WITH TIME. LATEST GFS AND
12Z ECMWF INDICATE THAT THIS SYSTEM MAY NOT BRING ANY RAIN TO OUR
AREA UNTIL FRIDAY. BASED ON THIS WILL GO WITH A DRY MILD FORECAST
WEDNESDAY THROUGH THURSDAY WITH ABOVE NORMAL HIGHS MAINLY IN THE MID
TO UPPER 60S AND LOWS IN THE 40S TO LOWER 50S. WILL BRING HIGH
CHANCE POPS ACROSS THE AREA FRIDAY AND CONTINUED MILD WITH HIGHS
MAINLY IN THE 60S. THE WEEKEND LOOKS COOLER AND CONTINUED UNSETTLED
WITH A CHANCE OF SHOWERS AS THE CLOSED LOW MOVES EAST ACROSS THE
AREA.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE INTO THIS EVENING WITH SOUTHERLY
WINDS INCREASING TO 5 TO 15 KTS. RAIN WILL SPREAD ACROSS CENTRAL
NY THIS EVENING WITH AREAS OF MVFR CIGS AND VSBYS DEVELOPING. THE
HEAVIEST STEADIEST RAIN WILL BE AT AT SYR AND RME. FARTHER SOUTH
JUST A FEW SHOWERS ARE EXPECTED... ALONG WITH AREAS OF MVFR VSBYS
AND CIGS. SOUTH-SOUTHWEST WINDS WILL INCREASE TO 10 TO 20 KTS WITH
A FEW GUSTS TO 25 KTS OVERNIGHT.
CONDITIONS WILL SLOWLY IMPROVE ON SUNDAY WITH CONDITIONS BECOMING
MOSTLY VFR DURING THE AFTERNOON. SOUTHWEST WINDS AT 10 TO 20 KTS
WILL CONTINUE WITH A FEW GUSTS TO 25 KTS THROUGH THE DAY.
OUTLOOK...
SUN NGT/MON/TUE...MVFR IN SHRA.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...HEDEN
LONG TERM...MSE
AVIATION...MSE
AREA FORECAST DISCUSSION
NWS NORMAN OK
345 PM CDT SAT OCT 13 2012
...SEVERE THUNDERSTORMS EXPECTED THROUGH 1 AM CDT TONIGHT
SOUTHEAST OF A CHEROKEE TO QUANAH LINE...
.DISCUSSION...
THE MAIN CONCERN IS ONGOING SEVERE THUNDERSTORMS.
CURRENT STORMS NEAR A SEYMOUR TO EL RENO LINE HAVE DEVELOPED JUST
AHEAD AND EAST OF THE DRYLINE. GENERALLY THINK THESE STORMS WILL
CONGEAL INTO ONE MAIN LINE BY 7 PM CDT NEAR AN ARCHER CITY TO ADA
LINE AND QUICKLY MOVE EAST...LIKELY EXITING ATOKA AND BRYAN
COUNTIES BY 1 AM CDT. THINK THE LATEST HRRR RUNS HANDLE THIS
WELL.
THE MAIN HAZARD IS DAMAGING WINDS UP TO 70 MPH...ESPECIALLY ONCE
STORMS FORM INTO ONE MAIN LINE. A COLD POOL OF AIR SEEMS TO BE
DEVELOPING WITH THE LINE OF STORMS FROM FREDERICK TO EL RENO
WHICH WILL ONLY GET STRONGER OVER THE NEXT FEW HOURS. NOT TO
MENTION...FORCING FROM THE APPROACHING MID/UPPER LOW/TROUGH OVER
WESTERN KANSAS AND THE PANHANDLES WILL ALLOW THE LINE OF STORMS
TO GROW AND PERHAPS ACCELERATE OVER THE NEXT SEVERAL HOURS.
THERE IS A POTENTIAL FOR TORNADOES AND LARGE HAIL UP TO GOLF
BALLS WITH DISCRETE SUPERCELLS AHEAD OF THE MAIN DEVELOPING
LINE...WHICH APPEARS TO BE MOST LIKELY SOUTHEAST OF A KNOX
CITY TO OKLAHOMA CITY TO CHANDLER LINE. LOW LCLS WITH SURFACE
DEWPOINTS AROUND 70 DEGREES...50-100 J/KG 0-3KM MLCAPE...AND
0-1 KM SRH 150 TO 300 M2/S2 SUPPORT LOW LEVEL ROTATING
SUPERCELLS. ANY SUPERCELLS WILL MOVE NORTHEAST AROUND
50 MPH.
ALL SEVERE STORMS WILL END BY 1 AM CDT TONIGHT.
BEYOND TONIGHT...GENERALLY DRY AND QUIET WEATHER WILL
PREVAIL. DID NOT CHANGE ANYTHING BEYOND SUNDAY.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 52 80 53 83 / 70 0 0 0
HOBART OK 51 82 51 82 / 10 0 0 0
WICHITA FALLS TX 55 83 54 86 / 70 0 0 0
GAGE OK 48 81 43 86 / 10 0 0 0
PONCA CITY OK 53 79 48 81 / 40 0 0 0
DURANT OK 60 82 54 84 / 100 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
06/17
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
942 PM CDT SUN OCT 14 2012
.DISCUSSION...
AT 9 PM THE COLD FRONT HAD MOVE THROUGH CROCKETT...MADISONVILLE...
COLLEGE STATION. SHOWER AND THUNDERSTORM ACTIVITY HAD DIMINISHED
OVER THE PAST COUPLE OF HOURS...HOWEVER BETWEEN 9 AND 930 PM
ISOLATED SHOWERS WERE BEGINNING TO DEVELOP ALONG A PREFRONTAL
TROUGH IN THE METRO HOUSTON AREA.
A LOOK AT THE 00Z UPPER AIR ANALYSES SHOWS THAT THE BEST 700 MB
MOISTURE WAS JUST TO THE EAST AND WEST OF THE FORECAST AREA.
HOWEVER...850 MB DEWPOINTS WERE BETWEEN 12 AND 14 CELCIUS. THE
LATEST RAP MODEL ALSO SHOWS THE BEST LOW-LEVEL CONVERGENCE OVER
THE SE TX COASTAL AREAS.
WITH THIS IN MIND...WILL ADJUST THE POPS SLIGHTLY DOWNWARD FOR THE
REMAINDER OF THIS EVENING...MAINLY TO ACCOUNT FOR THE LOCATION OF
THE FRONT AND THE CURRENT LACK OF SHOWER ACTIVITY. DO THINK THAT
BETTER COVERAGE WILL OCCUR AS THE FRONT MOVES INTO THE BETTER
MOISTURE ALONG THE COAST...AND WILL KEEP THE OVERNIGHT POPS IN
PLACE.
40
&&
.PREV DISCUSSION... /ISSUED 714 PM CDT SUN OCT 14 2012/
DISCUSSION...
PLEASE SEE 00Z AVIATION DISCUSSION.
AVIATION...
THE COLD FRONT CURRENTLY EXTENDS ALONG A LINE FROM NEAR
LIVINGSTON TO SEGUIN. MOST OF THE SHOWER AND THUNDERSTORM ACTIVITY
ASSOCIATED WITH THE FRONT HAS DIED OUT WITH THE EXCEPTION OF SCATTERED
SHOWERS AND THUNDERSTORMS EXTENDING FROM 30 TO BEYOND 100 MILES
WEST OF THE HOUSTON METRO AREA. IT LOOKS MORE LIKE A DRY FRONTAL
PASSAGE FOR THE HOUSTON TERMINALS. AT ITS PRESENT SPEED...THE
FRONT SHOULD MOVE OFF THE COAST BETWEEN 06 AND 07Z SATURDAY
MORNING.
BEHIND THE FRONT...CLEAR SKIES...UNLIMITED VISIBILITY...AND NORTH
WINDS BETWEEN 5-10 KNOTS SHOULD PREVAIL. 44
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 59 84 59 81 64 / 10 10 0 10 10
HOUSTON (IAH) 65 86 59 83 64 / 30 10 0 10 10
GALVESTON (GLS) 73 83 70 82 73 / 30 10 0 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...40
AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
353 PM CDT SAT OCT 13 2012
.AVIATION...
355 PM
WILL BACK UP TSRA TIMING WITH 21Z AMENDMENTS. PER HRRR AND TX
TECH WRF...FEEL NOW THAT TSRA LINE WILL LIKELY MAKE SLOW EASTWARD
PROGRESS UNTIL COLD FRONT CATCHES UP WITH THE DRY LINE/TROUGH.
CANNOT RULE OUT CONVECTION AHEAD OF LINE...BUT CURRENT
CLOUD/SHOWER ACTIVITY HAS LIMITED HEATING...CURRENTLY ABOUT 2-3
DEGREES BELOW CONVECTIVE TEMPERATURE WITH MAX HEATING ALREADY
BEHIND US AND CLOUD COVER STILL FAIRLY EXTENSIVE. WEAK FORCING
MAY WEAKEN THE INVERSION ENOUGH FOR A FEW TSRA TO FORM THIS
EVENING AHEAD OF THE LINE. 84
&&
.PREV DISCUSSION... /ISSUED 303 PM CDT SAT OCT 13 2012/
SHORTWAVE THIS MORNING NOW TRACKING NORTHEAST ACROSS THE AREA AND
HAS PRODUCED SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS MAINLY
ALONG AND WEST OF INTERSTATE 35W/35E. WITH A RELATIVELY STRONG
CAP THIS MORNING...THIS FIRST DISTURBANCE WILL ACT AS SOMEWHAT OF
A PRIMER TO LIFT AND WEAKEN THE CAP IN ADVANCE OF THE LARGE SCALE
ASCENT THAT IS NOW ENTERING NORTHWEST TEXAS. A PRE-FRONTAL TROUGH
FROM JUST WEST OF WICHITA FALLS TO NEAR SWEETWATER WAS BECOMING
ACTIVE THIS AFTERNOON WITH A FEW SUPERCELLS DEVELOPING IN THE
VICINITY OF HASKELL AS OF THE PAST HOUR. WE EXPECT THE PACIFIC
COLD FRONT FURTHER WEST OVER THE TEXAS PANHANDLE TO EVENTUALLY
OVERTAKE THE PRE-FRONTAL TROUGH THROUGH THIS AFTERNOON WITH
INCREASING STORMS ACROSS OUR FAR WESTERN COUNTIES BY MID-LATE
AFTERNOON. CONVECTIVE TEMPERATURE IS AROUND 85 DEGREES PER THIS
MORNINGS FWD SOUNDING AND AMDAR VAPOR AND WE ARE JUST A FEW
DEGREES BELOW THAT. WITH THIS ALL IN MIND...OUR FIRST WATCH OF
THE DAY HAS BEEN ISSUED ACROSS OUR NORTHWEST COUNTIES. TORNADO
WATCH 661 IS IN EFFECT UNTIL 9 PM NORTHWEST OF AN
EASTLAND...MINERAL WELLS...SAINT JO LINE.
WE DO EXPECT THE SEVERE WEATHER THREAT TO RAMP UP ACROSS THE
WESTERN HALF OF NORTH TEXAS IN THE 4-7 PM TIME FRAME...AS THE
LARGE SCALE ASCENT APPROACHES FROM THE WEST. WITH MORE OF A CAP
TO ERODE ACROSS NORTH TEXAS VERSUS OKLAHOMA...ITS LIKELY THE
STORM MODE WILL BE MORE CELLULAR INITIALLY VERSUS A SOLID SQUALL
LINE THAT IS EXPECTED FURTHER TO THE NORTH. MLCAPE NOW ACROSS THE
WESTERN COUNTIES IS 1000-1500 J/KG WITH 0-3KM/0-1KM HELICITIES
RANGING FROM 150-300 M2/S2 ACROSS THE WATCH AREA. THROW IN 0-6KM
BULK SHEAR ON THE ORDER OF 45-50KTS INDICATES THAT WIND FIELDS
WILL BE MORE THAN ENOUGH FOR THE ORGANIZATION OF STRONG TO SEVERE
STORMS. INITIAL THREATS INTO EARLY EVENING WILL BE LARGE HAIL...
DAMAGING WINDS AND THE POSSIBILITY OF A TORNADO WITH CELLS
REMAINING DISCRETE. BY MID EVENING... A 40-50 KT LLJ WILL LIKELY
CONGEAL STORMS INTO A LINEAR MCS...WHICH WILL MOVE SOUTH AND EAST
OVERNIGHT AND SLOW DOWN. WE THINK THE GREATEST SEVERE WEATHER
RISK WILL REMAIN ACROSS THE NORTHWEST HALF OF THE CWA...THEN
BECOME MORE LOCALIZED WITH A POSSIBLE INCREASING HYDROLOGICAL
SITUATION FOR OUR SOUTHEAST HALF OF THE CWA OVERNIGHT AND EARLY
SUNDAY MORNING...THOUGH A VEERING LLJ OVERNIGHT SHOULD KEEP ANY
FLOODING MINOR AND LOCALIZED.
WE EXPECT THE PACIFIC FRONT TO CONTINUE ITS SOUTHEAST MIGRATION
THROUGH THE MORNING HOURS SUNDAY AND LIKELY ENDING RAIN CHANCES
ACROSS OUR CENTRAL AND SOUTHEAST TEXAS COUNTIES BY EARLY
AFTERNOON. DRY AIR WILL THEN INFILTRATE INTO THE AREA BY SUNDAY
EVENING AND INTO THE FIRST HALF OF THE WORK WEEK WITH HIGHS IN
THE 80S AND LOWS IN THE 50S AND LOWER 60S. A WEAK SOUTHERN BRANCH
SHORTWAVE TROUGH WILL MOVE ACROSS SOUTH TEXAS LATE TUESDAY INTO
WEDNESDAY...BUT NOTHING IS EXPECTED ACROSS NORTH TEXAS OUTSIDE OF
INCREASING SOUTH WINDS AND SOME MODIFIED MOISTURE RETURN BACK
NORTH ACROSS MAINLY EAST TEXAS AND THE LOWER MISSISSIPPI VALLEY.
ACCOMPANYING COLD FRONT WILL ARRIVE WEDNESDAY NIGHT INTO THURSDAY
AND HAVE PUSHED BEST RAIN CHANCES TO THIS TIME PERIOD MAINLY EAST
OF I-35. SEE ENOUGH FORCING WITH THE FRONT AND LAPSE RATES ALOFT
FOR THE MENTION OF THUNDER WITH THIS FRONT.
FOR THURSDAY AND FRIDAY...AN UPPER LOW DEEPENS OVER THE UPPER
MIDWEST AND GREAT LAKES...HELPING TO KEEP A DRY AND COOL
CONTINENTAL AIRMASS ACROSS NORTH TEXAS. AS THE UPPER LOW MOVES
TOWARD NEW ENGLAND NEXT WEEKEND...WE SHOULD SEE AN UPPER RIDGE
ESTABLISH OVER THE SOUTHERN PLAINS WITH A RETURN OF BREEZY SOUTH
WINDS AND WARMER TEMPERATURES ONCE AGAIN.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 66 84 58 85 60 / 70 5 5 0 5
WACO, TX 69 84 55 84 57 / 70 30 5 5 5
PARIS, TX 65 82 54 83 55 / 60 10 5 0 0
DENTON, TX 62 83 52 85 55 / 70 5 0 0 5
MCKINNEY, TX 65 83 52 84 55 / 60 10 5 0 0
DALLAS, TX 67 83 59 86 61 / 60 10 5 0 5
TERRELL, TX 68 83 55 86 57 / 60 20 5 0 5
CORSICANA, TX 69 84 57 84 58 / 70 30 5 5 5
TEMPLE, TX 70 83 56 85 59 / 70 40 5 5 5
MINERAL WELLS, TX 58 86 54 84 55 / 70 5 0 5 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS SPOKANE WA
902 PM PDT Sun Oct 14 2012
.SYNOPSIS...Rain is expected to spread over the remainder of the
Inland Northwest tonight, as a cold front moves through the region.
A strong storm will arrive early Tuesday morning, bringing widespread
rain and windy conditions. Wind gusts of 35 to 45 mph will be
likely on Tuesday afternoon over portions of the Inland Northwest.
A drier, more stable pattern is expected for Wednesday and
Thursday, before more precipitation chances enter late in the week
with cooler temperatures.
&&
.DISCUSSION...
The cold front is beginning to make its way east of the Cascades.
Latest radar imagery at around 8:30 PM PDT this evening is
starting to show some enhanced echos developing over the Moses
Lake Area and Upper Columbia Basin. The leading edge of the front is
slightly further to the northwest, stretching from around Oroville
to Lincoln City in northeast Oregon. Out ahead of the front,
further east over the basin and into the ID Panhandle, very light
rain has been falling due to some weak isentropic accent. These
showers have generally yielded a few hundredths of an inch of
rainfall, except in the mountains where orographic have produced
slightly higher amounts up to around a tenth or more in the last
five hours or so. Expect rainfall to pick up in intensity a bit as
the cold front produces stronger lift as it moves east across the
region tonight.
Increased precipitation chances a bit and rainfall amounts,
especially in the basin where around a tenth of an inch from the
frontal band is expected. The HRRR model seems to have a better
handle on this frontal band with it moving through the Palouse,
Spokane Area and Northeast Mountains between 10:00 PM and 2:00 AM
tonight. Some lingering showers will pop up behind the front as low
to mid levels of the atmosphere become slightly more unstable with
the upper level shortwave moving through. However, the upper level
wave is fairly weak and the atmosphere will dry out from the top
down; so, I don`t expect a lot of shower activity once the front
pushes east and rain may just transition to a little drizzle
instead. Showers will continue to be more likely in the Panhandle
mountains due to terrain effects. Rainfall amounts will be highest
in the ID Panhandle where a quarter of an inch of rain or more is
expected between midnight tonight and tomorrow morning. These
amounts shouldn`t be much of a concern and probably will be well
received due to our extended stretch dry weather since late July
through early October. /SVH
&&
.AVIATION...
00Z TAFS: A cold front sagging southeast into northwest WA will
result in light to moderate rainfall this evening into tonight
across the region. At 00Z Monday, showers are developing east of a
line from KYKM to KOMK as the front begins to cross east of the
Cascades. Cigs will start out high based at around 10 kft, but will
be dropping through the evening as lower levels of the atmosphere
moisten. Expect MVFR/IFR cigs with MVFR vis, mainly for the KGEG,
KSFF, KCOE and KPUW taf sites. Stronger winds aloft of around 35 mph
at 1500 feet agl will result in some weak low level wind shear with
frontal passage. This frontal band will exit southeast of the region
late Sunday morning with some lingering showers remaining over the
mountains into Sunday afternoon. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 53 64 50 57 36 55 / 100 40 100 50 10 0
Coeur d`Alene 52 61 49 54 34 53 / 100 90 100 70 10 10
Pullman 51 66 50 55 34 54 / 100 70 90 80 10 0
Lewiston 55 72 56 60 40 59 / 70 60 80 60 10 0
Colville 50 63 49 57 29 56 / 90 40 100 30 10 10
Sandpoint 50 58 50 52 32 51 / 100 100 100 70 10 10
Kellogg 49 58 50 50 33 49 / 100 100 100 100 20 10
Moses Lake 52 71 51 64 36 59 / 70 30 30 10 0 0
Wenatchee 52 68 51 61 38 58 / 40 20 50 10 0 0
Omak 47 66 47 60 34 59 / 50 20 60 10 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
626 PM CDT SUN OCT 14 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
307 PM CDT SUN OCT 14 2012
BIGGEST FORECAST CHALLENGES ARE ON THE TIMING OF THE ENDING OF THE
PRECIPITATION TONIGHT ALONG WITH CLOUD TRENDS. ALSO RAIN CHANCES ON
WEDNESDAY.
18Z SURFACE ANALYSIS SHOWS AN AREA OF LOW PRESSURE OVER NORTHERN
ILLINOIS...WITH RADAR SHOWING A DEFORMATION BAND OF RAIN OVER
SOUTHERN AND CENTRAL WISCONSIN AND NORTHERN ILLINOIS. THE BACK EDGE
HAS STEADILY BEEN MOVING EASTWARD AND NOW EXTENDS FROM AROUND
NEILLSVILLE WISCONSIN...TO MONONA IOWA. VISIBLE SATELLITE IMAGERY
SHOWING BACK EDGE OF CLOUDS PUSHING INTO EASTERN MINNESOTA...WITH A
BATCH OF MID LEVEL CLOUDS OVER NORTHERN MINNESOTA.
14.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. IN THE
NEAR TERM...SURFACE LOW WILL CONTINUE TO PULL NORTHEAST INTO LOWER
MICHIGAN THIS EVENING. DEFORMATION AREA OF RAIN WILL CONTINUE TO
SHIFT EASTWARD. THE 14.12Z RAP AND 14.12Z GFS PUSH THE PRECIPITATION
TO THE EAST OF THE AREA BY 00Z...WHILE THE NAM IS A LITTLE SLOWER.
BASED ON MOVEMENT OF THE BACK EDGE...BELIEVE IT WILL CLEAR THE
FORECAST AREA BY 00Z. QUESTION THEN BECOMES HOW QUICKLY THE SKIES
CLEAR. BOTH THE NAM AND GFS RELATIVE HUMIDITY PROGS SHOW THE LOWER
STRATUS TO ADVECT EASTWARD THIS EVENING...BUT SOME MID LEVEL MOISTURE
AROUND 700MB ROTATES SOUTHWARD FROM NORTHERN MINNESOTA INTO THE
AREA. VISIBLE SATELLITE IMAGERY SHOWS THIS MOISTURE NOW OVER NORTHERN
MINNESOTA. THUS DID ADD DOME MORE CLOUDS TO THE EVENING HOURS BEFORE
CLEARING AFTER MIDNIGHT. BETWEEN THE CLOUDS AND THE PRESSURE
GRADIENT REMAINING TIGHT DO NOT EXPECT ANY FOG FORMATION DESPITE THE WET
GROUND FROM THE RAIN.
SURFACE HIGH PRESSURE BUILDS IN MONDAY...WITH THE RIDGE AXIS
QUICKLY MOVING EAST MONDAY NIGHT. 850MB TEMPERATURES IN THE 5 TO 7
DEGREE RANGE CELSIUS AND PLENTY OF SUN WILL MAKE FOR TEMPERATURES
NEAR THE SEASONAL NORMALS. WARM ADVECTION SPREADS ACROSS THE AREA ON
THE BACK SIDE OF THE HIGH MONDAY NIGHT AS A A WEAK SHORTWAVE DROPS
ACROSS THE PLAINS. FORCING SIGNALS RATHER WEAK AND FEEL BEST CHANCES
FOR PRECIPITATION WILL BE ACROSS THE FAR NORTH.
WARM ADVECTION CONTINUES IN EARNEST ON TUESDAY AS 850MB TEMPERATURES
RISE INTO THE LOWER TEENS CELSIUS. WITH A SOUTHWESTER LOW LEVEL
FLOW...EXPECT TEMPERATURES TO TOP OFF IN THE 60S TO LOWER 70S. A
SHORTWAVE WILL TRANSLATE ALONG THE CANADIAN BORDER WITH SOME WEAK
FORCING ACROSS NORTHERN WISCONSIN. GFS AND ECMWF DO GENERATE SOME
LIGHT QPF ACROSS THE FAR NORTHERN COUNTIES...WHILE NAM IS RELATIVELY
DRY. DID KEEP THE LOWER END PROBABILITIES FOR THIS TIME FRAME.
ON WEDNESDAY...A 130 KNOT 300MB JET DIGS DOWN ACROSS THE ROCKIES
INTO THE PLAINS. IN RESPONSE A STRENGTHENING 500MB CLOSED LOW WILL
DROP SOUTHWARD TO NEAR LAKE WINNIPEG. THIS AMPLIFIED FLOW WILL PUSH
A COLD FRONT ACROSS THE AREA...WITH RATHER IMPRESSIVE COLD ADVECTION
IN ITS WAKE. STRONG DYNAMIC FORCING WITH FGEN SIGNAL PUSHES ACROSS
THE AREA. MODELS CONSISTENT WITH PUSHING A BAND OF PRECIPITATION
ACROSS THE AREA WEDNESDAY. SOME WEAK INSTABILITIES LOOK TO BE
PRESENT ACROSS IOWA AND SOUTHWEST WISCONSIN. DID RAISE PROBABILITIES
IN THIS TIME FRAME AND KEPT THE MENTION OF THUNDER ACROSS THE SOUTH.
THESE PRECIPITATION CHANCES WILL REMAIN WEDNESDAY NIGHT AS 500MB
CLOSED LOW SLOWLY CONTINUES TO SINK SOUTHWARD INTO THE AREA.
.LONG TERM...THURSDAY THROUGH SUNDAY
307 PM CDT SUN OCT 14 2012
THE AFOREMENTIONED 500MB LOW WILL BE THE MAIN WEATHER FEATURE OF
INTEREST AT LEAST THROUGH THE EARLY PORTIONS OF THE WEEKEND. ONCE
AGAIN THE 14.12Z GFS IS FASTER AT OPENING THE WAVE UP AND PUSHING IT
EASTWARD ON SATURDAY...WHILE THE ECMWF MAINTAINS ITS CONTINUITY IN
SLOWLY LIFTING IT NORTHEAST LATER IN THE WEEKEND. GIVEN STRENGTH OF
SYSTEM THE SLOWER SOLUTIONS LOOKS MORE REASONABLE AT THIS POINT. WILL
CONTINUE TO SEE RAIN CHANCES THROUGH THE ENTIRE PERIOD. TEMPERATURES
LOOK TO BE BELOW NORMAL...WITH SLOW WARMING TREND BY SUNDAY AS THE
LOW PUSHES AWAY. WILL HAVE TO WAIT FOR LATER MODEL RUNS TO PIN DOWN
ANY OF THE DETAILS.
&&
.AVIATION...TONIGHT AND MONDAY
626 PM CDT SUN OCT 14 2012
VFR CONDITIONS EXPECTED AT KRST/KLSE THROUGH THE PERIOD AS THE
SURFACE LOW PRESSURE SYSTEM RESPONSIBLE FOR RECENT CLOUDS AND
PRECIPITATION LIFTS AWAY FROM THE REGION. AN AXIS OF 800-850 MB
MOISTURE WILL SWING OVER THE TAF SITES TONIGHT...BRINGING A BRIEF
PERIOD OF SCATTERED CLOUDS WITH BASES BETWEEN 5 AND 7 KFT.
REGARDING VALLEY FOG AT KLSE...DESPITE THE COPIOUS AMOUNTS OF RAIN
TODAY...WINDS JUST OFF THE SURFACE WILL BE 10 KTS OR GREATER.
COMBINED WITH DRIER AIR ADVECTING IN FROM THE NORTHWEST...BOTH OF
THESE FACTORS SHOULD PRECLUDE FOG/STRATUS DEVELOPMENT. FOR
MONDAY...SURFACE HIGH PRESSURE WILL DOMINATE...RESULTING IN LIGHT
NORTHWESTERLY WINDS AND MOSTLY SUNNY SKIES. BY MONDAY EVENING...WINDS
ARE EXPECTED TO BECOME SOUTHERLY AND HIGH LEVEL CLOUDS AT OR ABOVE
20 KFT WILL SPILL OVER THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
307 PM CDT SUN OCT 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
305 PM CDT SAT OCT 13 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
305 PM CDT SAT OCT 13 2012
MAIN FORECAST CONCERN IS ON RAIN CHANCES THROUGH SUNDAY.
18Z SURFACE ANALYSIS SHOWS BROAD AREA OF LOW PRESSURE OVER THE
PLAINS...WITH A WARM FRONT DRAPED ACROSS NORTHERN AND EASTERN IOWA.
HIGHER DEW POINT AIR FOUND ALONG AND SOUTH OF THIS BOUNDARY FROM
IOWA SOUTHWARD. AREA RADAR SHOWS HEAVIEST PRECIPITATION OVER EASTERN
WISCONSIN...WITH A DEFORMATION AREA OF LIGHTER RAIN NORTH OF
INTERSTATE 90.
13.12Z MODELS OVERALL OFFER SIMILAR SOLUTIONS...WITH JUST SOME MINOR
DETAIL DIFFERENCES IN CLEARING THE RAIN OUT ON MONDAY.
IN THE NEAR TERM...MAIN WAVE LOOKS TO LIFT EAST-NORTHEAST TONIGHT
INTO ILLINOIS. WITH THE LOW CLOUDS LIMITED INSTABILITY EXPECTED OVER
THE AREA AND THUS SEVERE WEATHER THREAT HAS SHIFTED FURTHER SOUTH
OUT OF THE AREA. LOW LEVEL FRONTOGENESIS STRENGTHENS THIS EVENING
ACROSS NORTHEAST IOWA INTO SOUTHWEST WISCONSIN AND WAVE LIFTS
TOWARDS THE AREA. EXPECT MAIN DEFORMATION OF RAIN TO RE-DEVELOP
ACROSS THE AREA...WITH THE HIGHEST PROBABILITIES AND QPF FROM
NORTHEAST IOWA INTO SOUTHWEST WISCONSIN. 13.15Z HRRR WOULD SUGGEST
NOT A LOT OF RAIN THROUGH 03Z...WITH ONLY SOME LIGHT DRIZZLE OR
LIGHT RAIN. WILL ADD MENTION OF FOG THROUGH THE EARLY EVENING HOURS
BEFORE MORE WIDESPREAD RAIN MOVES IN AFTER 03Z. 13.18Z RAP AND 13.12Z
NAM AND GFS ALL SHOWING JUST 200-300 J/KG OF MOST UNSTABLE CAPES
THIS EVENING AND THUS DID KEEP SCATTERED THUNDER IN THE FORECAST.
WAVE ROTATES THROUGH ILLINOIS EARLY SUNDAY MORNING AND INTO LOWER
MICHIGAN BY AFTERNOON. DEFORMATION PRECIPITATION AREA TO REMAIN OVER
THE FAR SOUTHERN COUNTIES THROUGH THE MORNING HOURS...WITH THE
PRECIPITATION THEN LIFTING TO THE EAST IN THE AFTERNOON. STILL
EXPECTING ANOTHER INCH OR SO OF RAINFALL FOR PORTIONS OF SOUTHWEST
WISCONSIN AND NORTHEAST IOWA THROUGH SUNDAY.
UPPER LEVEL RIDGING THEN BUILDS INTO THE REGION FOR SUNDAY NIGHT
INTO MONDAY. EXPECT THE CLOUDS TO BEGIN CLEARING OUT FROM WEST TO
EAST SUNDAY AFTERNOON...WITH CLEAR SKIES EXPECTED SUNDAY NIGHT. WITH
THE SURFACE HIGH DROPPING SOUTH THROUGH THE CENTRAL
PLAINS...SOUTHERLY WINDS ON MONDAY WILL PULL SOME WARMER AIR
NORTHWARD...WITH TEMPERATURES EXPECTED TO BE ABOVE NORMAL...PERHAPS
HITTING 70 DEGREES OVER SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
THE NEXT WAVE THEN BEGINS TO DROP THROUGH THE NORTHERN PLAINS
MONDAY NIGHT INTO TUESDAY. SOUTHERLY WINDS WILL KEEP THE
TEMPERATURES UP MONDAY NIGHT WITH THE FRONT THEN APPROACHING THE
AREA TUESDAY. UPPER WAVE LOOKS TO TRACK ACROSS NORTHERN WISCONSIN
TUESDAY AND ALTHOUGH NOT A LOT OF MOISTURE TO WORK WITH...COULD SEE
A FEW SHOWERS AND THUS LOWER END PROBABILITIES LOOK REASONABLE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
305 PM CDT SAT OCT 13 2012
THIS PERIOD LOOKS TO BE DOMINATED BY A DIGGING TROUGH ACROSS THE
NORTHERN PLAINS INTO THE GREAT LAKES REGION. BOTH THE 13.12Z ECMWF
AND GFS BOTH CARVE THIS UPPER LOW OUT IN THE WEDNESDAY/THURSDAY TIME
FRAME...BUT THEN DIVERGE IN THEIR SOLUTIONS BEYOND THURSDAY. GFS
MORE PROGRESSIVE IN OPENING THE WAVE UP AND PUSHING IT EASTWARD
FRIDAY/SATURDAY...WHILE THE ECMWF SPINS THE UPPER LOW OVER THE UPPER
MIDWEST/GREAT LAKES REGION INTO SATURDAY. GIVEN THESE UNCERTAINTIES
FEEL THAT PROBABILITIES ARE WARRANTED THROUGH THE ENTIRE PERIOD.
TEMPERATURES LOOK TO BE AT OR BELOW NORMAL FOR MUCH OF THE TIME
PERIOD.
&&
.AVIATION...THROUGH SUNDAY MORNING
101 AM CDT SAT OCT 13 2012
FOR THIS AFTERNOON...KRST WILL HAVE LIFR CEILINGS AND DENSE FOG
THROUGH 13.21Z AND THEN THE CEILINGS AND VISIBILTIES WILL IMPROVE
A BIT. THERE WILL ALSO BE SOME DRIZZLE/LIGHT RAIN DURING THIS
TIME. KLSE WILL HAVE IFR CEILINGS AND MVFR VISIBILITIES.
FOR TONIGHT...A LOW PRESSURE SYSTEM WILL MOVE NORTHEAST FROM
EASTERN KANSAS TO NORTHERN ILLINOIS. AS THIS LOW PRESSURE SYSTEM
APPROACHES ANOTHER ROUND OF SHOWERS AND SCATTERED THUNDERSTORMS
WILL MOVE INTO THE AREA BETWEEN 14.00Z AND 14.03Z...AND THEN
LINGER INTO SUNDAY MORNING. THE THUNDERSTORM THREAT LOOKS TOO
SMALL TO BE MENTIONED IN THE TAFS. SOUNDINGS SUGGEST THAT THE LOW
LEVELS WILL BE SATURATED SO EXPECT LIFR/IFR CEILINGS TONIGHT.
VISIBILITIES WILL BE RESTRICTED 3 MILES OR LESS MAINLY DUE TO THE
MIST/FOG.
ON SUNDAY MORNING...AS THE LOW PRESSURE SYSTEM SLOWLY PULLS AWAY
FROM THE AREA. BOTH THE CEILINGS AND VISIBILITIES WILL SLOWLY IMPROVE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 PM CDT SAT OCT 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
634 AM CDT SAT OCT 13 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
306 AM CDT SAT OCT 13 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH SUNDAY
AS WELL AS POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND EVENING.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED SPLIT FLOW ACROSS NORTH AMERICA. THE NORTHERN STREAM IS A
WEST-NORTHWEST FLOW FROM SOUTHWEST CANADA INTO NEW ENGLAND...WITH A
100 KT JET STREAK PRESENT OVER ONTARIO AT 200MB WITHIN THE FLOW. IN
THE SOUTHERN STREAM...AN UPPER LOW WAS PRESENT OVER WESTERN COLORADO
WITH A POTENT SHORTWAVE IN EASTERN ARIZONA...WHILE SUBTROPICAL
RIDGING WAS BUILDING AHEAD OF IT ACROSS MUCH OF THE MISSISSIPPI
RIVER VALLEY. 850MB PROFILER AND VWP DATA SHOWING SOUTH TO SOUTHWEST
WINDS OF 40-50 KT UNDER THE SUBTROPICAL RIDGE...HELPING TO ADVECT
GULF OF MEXICO MOISTURE TOWARDS THE FORECAST AREA. GOES DERIVED
PRECIPITABLE WATER SHOWED VALUES OF 1.3 INCHES APPROACHING NORTHEAST
IOWA WITH 1.5-1.7 INCH VALUES LURKING TO THE SOUTHWEST IN THE
KANSAS CITY AREA. SHOWER AND THUNDERSTORM DEVELOPMENT HAS BEEN
TAKING PLACE ON THE LEADING EDGE OF THIS MOISTURE SURGE ACROSS
WISCONSIN...AIDED TOO BY THE RIGHT ENTRANCE REGION OF THE NORTHERN
STREAM UPPER JET STREAK. ANOTHER SURGE OF MOISTURE LEADING TO
SHOWER AND THUNDERSTORM DEVELOPMENT OVER EASTERN NEBRASKA INTO
NORTHERN MISSOURI. AT THE SURFACE...A GENERAL LEE TROUGH WAS
PRESENT ALL UP AND DOWN THE WESTERN SIDE OF THE PLAINS...WITH A
RELATIVELY TIGHT PRESSURE GRADIENT PRESENT AHEAD OF THE TROUGH
EASTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF INCREASING
CLOUDS AND WARM/MOIST ADVECTION ON THE SOUTHERLY BREEZE HAVE
HELPED TO BRING TEMPERATURES UP OVERNIGHT.
UPPER LEVEL PATTERN DISCUSSION...MODELS HAVE DEFINITELY TRENDED
FARTHER SOUTH AND SLOWER WITH THE UPPER LOW COMING OUT OF COLORADO
OVER THE PAST FEW DAYS. LATEST 13.00Z GUIDANCE...WHICH FOLLOWS A
SUGGESTION MADE BY THE 12.06Z NAM YESTERDAY...SUGGESTS THE UPPER LOW
IS GOING TO STAY MORE PHASED WITH THE POTENT SHORTWAVE COMING OUT OF
ARIZONA. AS A RESULT...THE UPPER LOW TAKES A TRACK ACROSS KANSAS
THIS AFTERNOON INTO TONIGHT...REACHING WESTERN MISSOURI BY 12Z
SUNDAY. AFTER 12Z SUNDAY...MODELS SPLIT INTO TWO CAMPS WITH THE
EJECTION NORTHEASTWARD OF THE UPPER LOW BY NORTHERN STREAM SHORTWAVE
TROUGHING DROPPING INTO THE NORTHERN PLAINS. THE 13.00Z
GFS/UKMET/CANADIAN/ECMWF TAKE A TRACK THROUGH CHICAGO INTO NORTHERN
LOWER MICHIGAN BY LATE SUNDAY...WHEREAS THE 13.00Z NAM AND 12.21Z
SREF MEAN HAVE A FARTHER SOUTHEAST TRACK TOWARDS TOLEDO OH. THESE
DIFFERENCES IN TRACKS ARE REFLECTED TOO AT THE SURFACE WITH THE
GFS/UKMET/CANADIAN/ECMWF DEPICTING THE ASSOCIATED SURFACE LOW GOING
FROM ST JOSEPH MO THROUGH MILWAUKEE AT 18Z SUNDAY...COMPARED TO THE
NAM/SREF HEADING THROUGH GARY INDIANA AT THE SAME TIME. THIS SETS UP
ISSUES WITH WHERE THE DEFORMATION BAND WILL IMPACT FOR THE TONIGHT
THROUGH SUNDAY TIME PERIOD...DISCUSSED BELOW. PLAN ON TAKING A
COMPROMISE APPROACH TO GIVE CREDIT TO THE NAM SUGGESTING A FARTHER
SOUTH TRACK WITH THE UPPER LOW TODAY.
TODAY...CURRENT AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS OVER
WESTERN WISCONSIN SHOULD KEEP PRESSING EAST THIS MORNING...AS IT IS
TIED TO THE LEADING EDGE OF 850MB MOISTURE TRANSPORT WHICH IS
PUSHING NORTHEAST. ADDITIONAL CONVECTIVE ACTIVITY LOOKS TO DEVELOP
SHORTLY OVER NORTHERN IOWA...AS SUGGESTED BY THE 13.00Z
NAM/CANADIAN/LOCAL WRF RUN...ASSOCIATED WITH THE NOSE OF A SECOND
MAXIMA OF 850MB MOISTURE TRANSPORT WITHIN THE MAIN MOISTURE
TRANSPORT ZONE. THIS COULD BE THE CURRENT CONVECTION SLIDING INTO
SOUTHWEST IOWA TOO ON THE LEADING EDGE OF HIGHER PRECIPITABLE
WATER. THE CONVECTIVE ACTIVITY WOULD SLIDE EAST ACROSS SOUTHERN
PORTIONS OF THE FORECAST AREA THIS MORNING. THUS...HIGHEST
PRECIPITATION CHANCES EXIST SOUTH OF I-90 THIS MORNING. DURING THE
AFTERNOON...PRECIPITATION SIGNALS ARE LESS CLEAR. ALL 850MB
MOISTURE TRANSPORT IS KIND OF POINTED AWAY FROM THE AREA...OR WE
ARE JUST UNDER THE STREAM WITH NO FOCUS AREAS. ALOFT AT
500MB...THERE REALLY IS NO FEATURE TO AID IN CONVECTIVE
DEVELOPMENT...AND IF ANYTHING WE ARE UNDER SOME WEAK SHORTWAVE
RIDGING AHEAD OF THE UPPER LOW. WE DO HAVE A WARM FRONTAL BOUNDARY
EXTENDING ACROSS NORTHERN IOWA INTO SOUTHERN WISCONSIN...WHICH
COMBINED WITH 500-1000 J/KG OF PROGGED MUCAPE COULD TRIGGER
CONVECTION. MODEL QPF FIELDS REFLECT THE LACK OF A PRECIPITATION
FOCUSING MECHANISM AS WELL. AS SUCH...HAVE KNOCKED PRECIPITATION
CHANCES DOWN INTO THE 50-70 RANGE FOR THE AFTERNOON. SHOULD
CONVECTION FIRE NEAR/ALONG THE WARM FRONT... 0-6KM...0-3KM AND
0-1KM SHEAR STILL SUPPORT POTENTIAL FOR SUPERCELLS AND LINE
SEGMENTS...WITH DAMAGING WIND AND TORNADOES POSSIBLE. THE SEVERE
CHANCES REALLY DEPEND ON IF WE CAN GET SOME SUN THIS AFTERNOON TO
HELP REACH THAT PROGGED INSTABILITY...WHICH IS HIGHLY UNCERTAIN
GIVEN THE STREAM OF CLOUDS WITHIN THE 850MB MOISTURE TRANSPORT
ZONE. GREATER CHANCES OF SEVERE WEATHER EXPECTED SOUTH OF THE
FORECAST AREA WHERE DYNAMICAL FORCING IS STRONGER. HIGH
TEMPERATURES ARE TRICKY TODAY. DID END UP COOLING THEM SOME DOWN
INTO THE 50S ALONG AND NORTHEAST OF I-94 WITH THE WARM FRONT
EXPECTED FARTHER SOUTH. ELSEWHERE...ADVECTION AND POTENTIAL FOR
SOME SLIGHT AMOUNT OF SUN SHOULD PUSH HIGHS INTO THE 60S AS
SUGGESTED BY MOST GUIDANCE. SHOULD MORE SUN OCCUR...850MB TEMPS OF
10-13C WOULD ALLOW READINGS TO TOP OUT WELL INTO THE 70S.
TONIGHT INTO SUNDAY...FOLLOWING THE COMPROMISE APPROACH MENTIONED IN
THE UPPER LEVEL DISCUSSION SECTION...WE SHOULD SEE A DEFORMATION
BAND OF PRECIPITATION FORM ON THE NORTH SIDE OF THE WARM FRONT THIS
EVENING. THIS BAND WOULD AFFECT THE SOUTHERN TWO-THIRDS OF THE AREA.
AS THE SURFACE LOW HEADS NORTHEAST INTO FAR SOUTHERN WISCONSIN
SUNDAY MORNING...ANTICIPATE THE BAND TO CONTINUE TO AFFECT THE SAME
AREA AND PERHAPS INTENSIFY AS THE LOW DEEPENS. DUE TO THE SLOWER
PROGRESS OF THE SYSTEM...HAVE HELD ONTO PRECIPITATION CHANCES
LONGER...WITH ONLY SOME OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA
DRYING OUT IN THE AFTERNOON. AN AREA SOUTHEAST OF A LINE FROM
DECORAH TO LA CROSSE AND BLACK RIVER FALLS STILL SEEMS POSSIBLE TO
PICK UP UPWARDS OF 1 TO 2 INCHES DURING THIS TIME PERIOD...
ESPECIALLY IF THE 13.00Z GFS/ECMWF PAN OUT. WITH MORE
CLOUDS/PRECIPITATION ON SUNDAY...COOLED HIGHS DOWN A BIT. MAY HAVE
TO LOWER MORE...AGAIN IF THE 13.00Z GFS/ECMWF PAN OUT. TONIGHTS
LOWS STILL SEEM REASONABLE WITH LITTLE CHANGE NEEDED.
SUNDAY NIGHT THROUGH MONDAY NIGHT...ATTENTION SHIFTS TO HOW QUICKLY
THE UPPER TROUGHING OVER THE FORECAST AREA...LEFT OVER BEHIND THE
STORM SYSTEM AND THE NEXT SHORTWAVE DROPPING INTO THE NORTHERN
PLAINS...SHIFTS OFF TO THE EAST. THE KICKING MECHANISM TO PUSH IT TO
THE EAST IS A SERIES OF SHORTWAVES DROPPING INTO MONTANA ON MONDAY.
THE 13.00Z NAM IS BY FAR THE FASTEST KICKING THE TROUGH OFF TO THE
EAST...RELATED TO THE SPEED OF THE STORM SYSTEM. THE OTHER SIDE OF
THE COIN IS THE 13.00Z GFS WHICH HANGS THE TROUGH UP OVER THE
EASTERN GREAT LAKES FOR MONDAY. THE ECMWF/UKMET LIE BETWEEN THE TWO
AND ARE PREFERRED. SKIES SHOULD GRADUALLY CLEAR SUNDAY NIGHT AS
SUBSIDENCE BUILDS IN BEHIND THE DEPARTING STORM SYSTEM AND HIGH
PRESSURE BUILDS IN AT THE SURFACE. DEPENDING ON THE SPEED OF
CLEARING...COULD SEE LOWS DIP BELOW FREEZING...ESPECIALLY AT THE
TYPICAL COLD SPOTS. DECENT WARMING OCCURS MONDAY...THOUGH...AS THE
SURFACE RIDGE HEADS EAST. 850MB TEMPS COULD POP UP TO 7-11C BY 00Z
TUESDAY. PREVIOUS FORECAST HIGHS HAVE THE WARMING HANDLED WELL.
WARMER NIGHT ON TAP MONDAY NIGHT WITH A RELATIVELY TIGHT PRESSURE
GRADIENT IN PLACE AHEAD OF THE MONTANA SHORTWAVES DROPPING INTO THE
DAKOTAS. NO PRECIPITATION ANTICIPATED WITH A DRY AIRMASS IN PLACE
AND THE BEST FORCING SITUATED NORTH OF THE AREA.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
306 AM CDT SAT OCT 13 2012
GENERAL THEME CONTINUES WITH THE 13.00Z GFS/ECMWF/CANADIAN AND GFS
ENSEMBLES OF DEEP TROUGHING DEVELOPING OVER THE NORTHERN PLAINS AND
UPPER MISSISSIPPI RIVER VALLEY REGION BY THURSDAY. HOWEVER...THE WAY
WE GET THERE IS SLIGHTLY DIFFERENT NOW. AT 12Z TUESDAY...MODELS
DEPICT A POTENT SHORTWAVE COMING INTO SOUTHERN BRITISH COLUMBIA WITH
A 140 KT JET AT 250MB ON ITS SOUTH SIDE. THE SHORTWAVE THEN DIGS
DOWN INTO THE NORTHERN PLAINS WITH ALL MODELS SHOWING UPPER LOW
DEVELOPMENT...PERHAPS AS EARLY AS WEDNESDAY. PRIOR TO THE UPPER LOW
ARRIVAL...THERE IS THOSE SHORTWAVES THAT WERE MOVING INTO THE
DAKOTAS AT 12Z TUESDAY. THESE END UP COMING ACROSS THE FORECAST AREA
TUESDAY NIGHT. ALTHOUGH THE AIRMASS IS SOMEWHAT DRY...THE FORCING
FROM THE WAVE...ESPECIALLY ACROSS NORTHERN PORTIONS OF THE
AREA...MAY BE STRONG ENOUGH TO OVERCOME THE DRY AIR AND RESULT IN
SOME LIGHT PRECIPITATION. NEXT CHANCE OF RAIN COMES WEDNESDAY AS
MOISTURE TRANSPORT AND DPVA INCREASE AHEAD OF THE DEVELOPING UPPER
LOW. THESE CHANCES MAY NEED TO BE RAISED IN FUTURE FORECASTS IF
TRENDS CONTINUE ON THE UPPER LOW DEVELOPMENT. THIS UPPER LOW THEN
SHIFTS INTO THE FORECAST AREA...BRINGING IN COOLER AIR AND LIKELY
MORE SHOWER ACTIVITY. MODELS THEN DIVERGE WITH HOW FAST THE UPPER
LOW LEAVES THE AREA FOR THE END OF THE WEEK. THE ECMWF SUGGESTS IT
GETS CUT OFF DUE TO BUILDING RIDGING ALONG THE EASTERN SEABOARD AND
IN THE WESTERN U.S.. THIS SCENARIO WOULD RESULT IN COOL...SHOWERY
DAYS AND NIGHTS. THE GFS AND MAJORITY OF ITS ENSEMBLES MEMBERS
SUGGEST A SLOW PROGRESSION NORTHEASTWARD...ALLOWING FOR DRYING
CONDITIONS TO COME IN FOR FRIDAY. TAKING THE CONSENSUS APPROACH FOR
NOW WITH 20-30 PERCENT CHANCES. COOL WEATHER STILL LOOKS REASONABLE
EVEN IN THE GFS CAMP AS 850MB TEMPS FALL TO 0-2C.
&&
.AVIATION...TODAY AND TONIGHT
634 AM CDT SAT OCT 13 2012
IFR/MVFR CONDITIONS ARE EXPECTED AT THE TAF SITES TODAY INTO
TONIGHT. A WARM FRONT WILL LIFT INTO NORTHEAST IOWA AND SOUTHWEST
WISCONSIN TODAY. SHOWERS AND SCATTERED THUNDERSTORMS WILL IMPACT
THE AREA TODAY INTO TONIGHT AS THE WARM FRONT STALLS NEAR THE
INTERSTATE 90 CORRIDOR AND A STRONG LOW PRESSURE SYSTEM OVER THE
CENTRAL PLAINS LIFTS NORTHEAST INTO THE UPPER MISSISSIPPI RIVER
VALLEY. LOW STRATUS WILL BRING IFR/MVFR CONDITIONS TO THE TAF
SITES. BRIEF LIFR CONDITIONS ARE POSSIBLE THIS MORNING AT KRST WITH
CLOUD BASES AROUND 400 FT. CLOUD BASES ARE EXPECTED TO BE AROUND
1000 FT AT KLSE THIS MORNING. CEILINGS SHOULD RISE SLIGHTLY THIS
AFTERNOON TO AROUND 1500FT. FORECAST SOUNDINGS SHOW THE POTENTIAL
FOR IFR/LIFR CONDITIONS IN LOW STRATUS AND FOG THIS EVENING INTO
THE OVERNIGHT HOURS. PLAN ON CEILINGS FALLING TO AROUND 900FT AT
KLSE BY 3Z...AND FALLING TO AROUND 500FT AT KRST BY 08Z. IN
ADDITION...FOG COULD REDUCE VISIBILITIES TO 4SM OR LESS AT KRST
TONIGHT AS EASTERLY UPSLOPE WINDS ADVECT LOW STRATUS INTO THE TAF
SITE.
&&
.HYDROLOGY...THROUGH SUNDAY
306 AM CDT SAT OCT 12 2012
QPF FORECAST STILL PROBLEMATIC...AGAIN DUE TO THE TRACK OF THE
STORM SYSTEM. MAIN FOCUS IS GOING TO BE ON THE DEFORMATION BAND ON
THE NORTH SIDE OF THE STORM SYSTEM TRACK...SINCE THIS IS GOING TO
HAVE THE BULK OF THE HEAVIER RAIN. THE LATEST 13.00Z ECMWF PROGS
A BAND OF 3-3.5 INCHES FROM PRAIRIE DU CHEIN NORTHEAST TOWARDS
WISCONSIN RAPIDS. THE 13.00Z GFS IS NOT TOO FAR OFF WITH A SIMILAR
BAND OF 2-4 INCHES IN ABOUT THE SAME PLACE. ON THE OTHER
HAND...THE FARTHER SOUTH AND FASTER 13.00Z NAM ENDS UP PRODUCING
THE HEAVY RAIN BAND ACROSS MUCH OF NORTHERN ILLINOIS. HAVE TAKEN A
COMPROMISE APPROACH BETWEEN THE TWO SCENARIOS...RESULTING IN AN
AREA OF 2 INCHES ACROSS THE SOUTHEASTERN 1/3 OF THE FORECAST AREA.
WILL HAVE TO SEE EVENTUALLY WHERE THE DEFORMATION BAND SETS UP TO
DETERMINE WHICH SCENARIO TO FOLLOW. NEEDLESS TO SAY...THE
LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN THE SEVERE
TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO FLOODING IS
ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 AM CDT SAT OCT 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
306 AM CDT SAT OCT 13 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
306 AM CDT SAT OCT 13 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH SUNDAY
AS WELL AS POTENTIAL FOR SEVERE WEATHER THIS AFTERNOON AND EVENING.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED SPLIT FLOW ACROSS NORTH AMERICA. THE NORTHERN STREAM IS A
WEST-NORTHWEST FLOW FROM SOUTHWEST CANADA INTO NEW ENGLAND...WITH A
100 KT JET STREAK PRESENT OVER ONTARIO AT 200MB WITHIN THE FLOW. IN
THE SOUTHERN STREAM...AN UPPER LOW WAS PRESENT OVER WESTERN COLORADO
WITH A POTENT SHORTWAVE IN EASTERN ARIZONA...WHILE SUBTROPICAL
RIDGING WAS BUILDING AHEAD OF IT ACROSS MUCH OF THE MISSISSIPPI
RIVER VALLEY. 850MB PROFILER AND VWP DATA SHOWING SOUTH TO SOUTHWEST
WINDS OF 40-50 KT UNDER THE SUBTROPICAL RIDGE...HELPING TO ADVECT
GULF OF MEXICO MOISTURE TOWARDS THE FORECAST AREA. GOES DERIVED
PRECIPITABLE WATER SHOWED VALUES OF 1.3 INCHES APPROACHING NORTHEAST
IOWA WITH 1.5-1.7 INCH VALUES LURKING TO THE SOUTHWEST IN THE
KANSAS CITY AREA. SHOWER AND THUNDERSTORM DEVELOPMENT HAS BEEN
TAKING PLACE ON THE LEADING EDGE OF THIS MOISTURE SURGE ACROSS
WISCONSIN...AIDED TOO BY THE RIGHT ENTRANCE REGION OF THE NORTHERN
STREAM UPPER JET STREAK. ANOTHER SURGE OF MOISTURE LEADING TO
SHOWER AND THUNDERSTORM DEVELOPMENT OVER EASTERN NEBRASKA INTO
NORTHERN MISSOURI. AT THE SURFACE...A GENERAL LEE TROUGH WAS
PRESENT ALL UP AND DOWN THE WESTERN SIDE OF THE PLAINS...WITH A
RELATIVELY TIGHT PRESSURE GRADIENT PRESENT AHEAD OF THE TROUGH
EASTWARD ACROSS THE FORECAST AREA. THE COMBINATION OF INCREASING
CLOUDS AND WARM/MOIST ADVECTION ON THE SOUTHERLY BREEZE HAVE
HELPED TO BRING TEMPERATURES UP OVERNIGHT.
UPPER LEVEL PATTERN DISCUSSION...MODELS HAVE DEFINITELY TRENDED
FARTHER SOUTH AND SLOWER WITH THE UPPER LOW COMING OUT OF COLORADO
OVER THE PAST FEW DAYS. LATEST 13.00Z GUIDANCE...WHICH FOLLOWS A
SUGGESTION MADE BY THE 12.06Z NAM YESTERDAY...SUGGESTS THE UPPER LOW
IS GOING TO STAY MORE PHASED WITH THE POTENT SHORTWAVE COMING OUT OF
ARIZONA. AS A RESULT...THE UPPER LOW TAKES A TRACK ACROSS KANSAS
THIS AFTERNOON INTO TONIGHT...REACHING WESTERN MISSOURI BY 12Z
SUNDAY. AFTER 12Z SUNDAY...MODELS SPLIT INTO TWO CAMPS WITH THE
EJECTION NORTHEASTWARD OF THE UPPER LOW BY NORTHERN STREAM SHORTWAVE
TROUGHING DROPPING INTO THE NORTHERN PLAINS. THE 13.00Z
GFS/UKMET/CANADIAN/ECMWF TAKE A TRACK THROUGH CHICAGO INTO NORTHERN
LOWER MICHIGAN BY LATE SUNDAY...WHEREAS THE 13.00Z NAM AND 12.21Z
SREF MEAN HAVE A FARTHER SOUTHEAST TRACK TOWARDS TOLEDO OH. THESE
DIFFERENCES IN TRACKS ARE REFLECTED TOO AT THE SURFACE WITH THE
GFS/UKMET/CANADIAN/ECMWF DEPICTING THE ASSOCIATED SURFACE LOW GOING
FROM ST JOSEPH MO THROUGH MILWAUKEE AT 18Z SUNDAY...COMPARED TO THE
NAM/SREF HEADING THROUGH GARY INDIANA AT THE SAME TIME. THIS SETS UP
ISSUES WITH WHERE THE DEFORMATION BAND WILL IMPACT FOR THE TONIGHT
THROUGH SUNDAY TIME PERIOD...DISCUSSED BELOW. PLAN ON TAKING A
COMPROMISE APPROACH TO GIVE CREDIT TO THE NAM SUGGESTING A FARTHER
SOUTH TRACK WITH THE UPPER LOW TODAY.
TODAY...CURRENT AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS OVER
WESTERN WISCONSIN SHOULD KEEP PRESSING EAST THIS MORNING...AS IT IS
TIED TO THE LEADING EDGE OF 850MB MOISTURE TRANSPORT WHICH IS
PUSHING NORTHEAST. ADDITIONAL CONVECTIVE ACTIVITY LOOKS TO DEVELOP
SHORTLY OVER NORTHERN IOWA...AS SUGGESTED BY THE 13.00Z
NAM/CANADIAN/LOCAL WRF RUN...ASSOCIATED WITH THE NOSE OF A SECOND
MAXIMA OF 850MB MOISTURE TRANSPORT WITHIN THE MAIN MOISTURE
TRANSPORT ZONE. THIS COULD BE THE CURRENT CONVECTION SLIDING INTO
SOUTHWEST IOWA TOO ON THE LEADING EDGE OF HIGHER PRECIPITABLE
WATER. THE CONVECTIVE ACTIVITY WOULD SLIDE EAST ACROSS SOUTHERN
PORTIONS OF THE FORECAST AREA THIS MORNING. THUS...HIGHEST
PRECIPITATION CHANCES EXIST SOUTH OF I-90 THIS MORNING. DURING THE
AFTERNOON...PRECIPITATION SIGNALS ARE LESS CLEAR. ALL 850MB
MOISTURE TRANSPORT IS KIND OF POINTED AWAY FROM THE AREA...OR WE
ARE JUST UNDER THE STREAM WITH NO FOCUS AREAS. ALOFT AT
500MB...THERE REALLY IS NO FEATURE TO AID IN CONVECTIVE
DEVELOPMENT...AND IF ANYTHING WE ARE UNDER SOME WEAK SHORTWAVE
RIDGING AHEAD OF THE UPPER LOW. WE DO HAVE A WARM FRONTAL BOUNDARY
EXTENDING ACROSS NORTHERN IOWA INTO SOUTHERN WISCONSIN...WHICH
COMBINED WITH 500-1000 J/KG OF PROGGED MUCAPE COULD TRIGGER
CONVECTION. MODEL QPF FIELDS REFLECT THE LACK OF A PRECIPITATION
FOCUSING MECHANISM AS WELL. AS SUCH...HAVE KNOCKED PRECIPITATION
CHANCES DOWN INTO THE 50-70 RANGE FOR THE AFTERNOON. SHOULD
CONVECTION FIRE NEAR/ALONG THE WARM FRONT... 0-6KM...0-3KM AND
0-1KM SHEAR STILL SUPPORT POTENTIAL FOR SUPERCELLS AND LINE
SEGMENTS...WITH DAMAGING WIND AND TORNADOES POSSIBLE. THE SEVERE
CHANCES REALLY DEPEND ON IF WE CAN GET SOME SUN THIS AFTERNOON TO
HELP REACH THAT PROGGED INSTABILITY...WHICH IS HIGHLY UNCERTAIN
GIVEN THE STREAM OF CLOUDS WITHIN THE 850MB MOISTURE TRANSPORT
ZONE. GREATER CHANCES OF SEVERE WEATHER EXPECTED SOUTH OF THE
FORECAST AREA WHERE DYNAMICAL FORCING IS STRONGER. HIGH
TEMPERATURES ARE TRICKY TODAY. DID END UP COOLING THEM SOME DOWN
INTO THE 50S ALONG AND NORTHEAST OF I-94 WITH THE WARM FRONT
EXPECTED FARTHER SOUTH. ELSEWHERE...ADVECTION AND POTENTIAL FOR
SOME SLIGHT AMOUNT OF SUN SHOULD PUSH HIGHS INTO THE 60S AS
SUGGESTED BY MOST GUIDANCE. SHOULD MORE SUN OCCUR...850MB TEMPS OF
10-13C WOULD ALLOW READINGS TO TOP OUT WELL INTO THE 70S.
TONIGHT INTO SUNDAY...FOLLOWING THE COMPROMISE APPROACH MENTIONED IN
THE UPPER LEVEL DISCUSSION SECTION...WE SHOULD SEE A DEFORMATION
BAND OF PRECIPITATION FORM ON THE NORTH SIDE OF THE WARM FRONT THIS
EVENING. THIS BAND WOULD AFFECT THE SOUTHERN TWO-THIRDS OF THE AREA.
AS THE SURFACE LOW HEADS NORTHEAST INTO FAR SOUTHERN WISCONSIN
SUNDAY MORNING...ANTICIPATE THE BAND TO CONTINUE TO AFFECT THE SAME
AREA AND PERHAPS INTENSIFY AS THE LOW DEEPENS. DUE TO THE SLOWER
PROGRESS OF THE SYSTEM...HAVE HELD ONTO PRECIPITATION CHANCES
LONGER...WITH ONLY SOME OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA
DRYING OUT IN THE AFTERNOON. AN AREA SOUTHEAST OF A LINE FROM
DECORAH TO LA CROSSE AND BLACK RIVER FALLS STILL SEEMS POSSIBLE TO
PICK UP UPWARDS OF 1 TO 2 INCHES DURING THIS TIME PERIOD...
ESPECIALLY IF THE 13.00Z GFS/ECMWF PAN OUT. WITH MORE
CLOUDS/PRECIPITATION ON SUNDAY...COOLED HIGHS DOWN A BIT. MAY HAVE
TO LOWER MORE...AGAIN IF THE 13.00Z GFS/ECMWF PAN OUT. TONIGHTS
LOWS STILL SEEM REASONABLE WITH LITTLE CHANGE NEEDED.
SUNDAY NIGHT THROUGH MONDAY NIGHT...ATTENTION SHIFTS TO HOW QUICKLY
THE UPPER TROUGHING OVER THE FORECAST AREA...LEFT OVER BEHIND THE
STORM SYSTEM AND THE NEXT SHORTWAVE DROPPING INTO THE NORTHERN
PLAINS...SHIFTS OFF TO THE EAST. THE KICKING MECHANISM TO PUSH IT TO
THE EAST IS A SERIES OF SHORTWAVES DROPPING INTO MONTANA ON MONDAY.
THE 13.00Z NAM IS BY FAR THE FASTEST KICKING THE TROUGH OFF TO THE
EAST...RELATED TO THE SPEED OF THE STORM SYSTEM. THE OTHER SIDE OF
THE COIN IS THE 13.00Z GFS WHICH HANGS THE TROUGH UP OVER THE
EASTERN GREAT LAKES FOR MONDAY. THE ECMWF/UKMET LIE BETWEEN THE TWO
AND ARE PREFERRED. SKIES SHOULD GRADUALLY CLEAR SUNDAY NIGHT AS
SUBSIDENCE BUILDS IN BEHIND THE DEPARTING STORM SYSTEM AND HIGH
PRESSURE BUILDS IN AT THE SURFACE. DEPENDING ON THE SPEED OF
CLEARING...COULD SEE LOWS DIP BELOW FREEZING...ESPECIALLY AT THE
TYPICAL COLD SPOTS. DECENT WARMING OCCURS MONDAY...THOUGH...AS THE
SURFACE RIDGE HEADS EAST. 850MB TEMPS COULD POP UP TO 7-11C BY 00Z
TUESDAY. PREVIOUS FORECAST HIGHS HAVE THE WARMING HANDLED WELL.
WARMER NIGHT ON TAP MONDAY NIGHT WITH A RELATIVELY TIGHT PRESSURE
GRADIENT IN PLACE AHEAD OF THE MONTANA SHORTWAVES DROPPING INTO THE
DAKOTAS. NO PRECIPITATION ANTICIPATED WITH A DRY AIRMASS IN PLACE
AND THE BEST FORCING SITUATED NORTH OF THE AREA.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
306 AM CDT SAT OCT 13 2012
GENERAL THEME CONTINUES WITH THE 13.00Z GFS/ECMWF/CANADIAN AND GFS
ENSEMBLES OF DEEP TROUGHING DEVELOPING OVER THE NORTHERN PLAINS AND
UPPER MISSISSIPPI RIVER VALLEY REGION BY THURSDAY. HOWEVER...THE WAY
WE GET THERE IS SLIGHTLY DIFFERENT NOW. AT 12Z TUESDAY...MODELS
DEPICT A POTENT SHORTWAVE COMING INTO SOUTHERN BRITISH COLUMBIA WITH
A 140 KT JET AT 250MB ON ITS SOUTH SIDE. THE SHORTWAVE THEN DIGS
DOWN INTO THE NORTHERN PLAINS WITH ALL MODELS SHOWING UPPER LOW
DEVELOPMENT...PERHAPS AS EARLY AS WEDNESDAY. PRIOR TO THE UPPER LOW
ARRIVAL...THERE IS THOSE SHORTWAVES THAT WERE MOVING INTO THE
DAKOTAS AT 12Z TUESDAY. THESE END UP COMING ACROSS THE FORECAST AREA
TUESDAY NIGHT. ALTHOUGH THE AIRMASS IS SOMEWHAT DRY...THE FORCING
FROM THE WAVE...ESPECIALLY ACROSS NORTHERN PORTIONS OF THE
AREA...MAY BE STRONG ENOUGH TO OVERCOME THE DRY AIR AND RESULT IN
SOME LIGHT PRECIPITATION. NEXT CHANCE OF RAIN COMES WEDNESDAY AS
MOISTURE TRANSPORT AND DPVA INCREASE AHEAD OF THE DEVELOPING UPPER
LOW. THESE CHANCES MAY NEED TO BE RAISED IN FUTURE FORECASTS IF
TRENDS CONTINUE ON THE UPPER LOW DEVELOPMENT. THIS UPPER LOW THEN
SHIFTS INTO THE FORECAST AREA...BRINGING IN COOLER AIR AND LIKELY
MORE SHOWER ACTIVITY. MODELS THEN DIVERGE WITH HOW FAST THE UPPER
LOW LEAVES THE AREA FOR THE END OF THE WEEK. THE ECMWF SUGGESTS IT
GETS CUT OFF DUE TO BUILDING RIDGING ALONG THE EASTERN SEABOARD AND
IN THE WESTERN U.S.. THIS SCENARIO WOULD RESULT IN COOL...SHOWERY
DAYS AND NIGHTS. THE GFS AND MAJORITY OF ITS ENSEMBLES MEMBERS
SUGGEST A SLOW PROGRESSION NORTHEASTWARD...ALLOWING FOR DRYING
CONDITIONS TO COME IN FOR FRIDAY. TAKING THE CONSENSUS APPROACH FOR
NOW WITH 20-30 PERCENT CHANCES. COOL WEATHER STILL LOOKS REASONABLE
EVEN IN THE GFS CAMP AS 850MB TEMPS FALL TO 0-2C.
&&
.AVIATION...THROUGH 06Z SUNDAY
1154 PM CDT FRI OCT 12 2012
FIRST ROUND OF SHOWERS MOVING ACROSS THE AREA NOW WITHOUT ANY
VISIBILITY RESTRICTIONS AND VFR CEILINGS. CONCERNS BASED ON THE
13.00Z NAM AND 12.12Z MESO MODELS IS JUST HOW MUCH RAIN IS GOING
TO DEVELOP OVERNIGHT INTO SATURDAY. REGIONAL RADARS NOT SHOWING A
WHOLE LOT GOING ON TO THE SOUTH AT THIS TIME. HOWEVER...AS THE LOW
LEVEL JET INTERACTS WITH THE WARM FRONT/DEW POINT BOUNDARY ACROSS
CENTRAL IOWA...EXPECT TO SEE AN INCREASE IN THE COVERAGE. THIS MAY
NOT HAPPEN UNTIL LATE TONIGHT OR EARLY SATURDAY MORNING AS INITIAL
DEVELOPMENT WOULD BE TO THE SOUTH WITH THE ACTIVITY THEN MOVING
NORTH. AS A RESULT...PLAN TO JUST STAY WITH VICINITY THUNDER OR
SHOWERS THROUGH THE NIGHT. THEN EXPECT THE ACTIVITY THAT DEVELOPS
TO REDUCE THE VISIBILITY FOR A FEW HOURS SATURDAY MORNING WITH
EITHER VFR OR MVFR BUT TAKING THE CEILINGS DOWN TO IFR. THE
NAM...HI-RES ARW...NMM AND HRRR ALL THEN SHOW THIS ACTIVITY MOVING
OFF TO THE EAST WITH A BREAK DURING THE LATE MORNING INTO THE
AFTERNOON BEFORE THE NEXT ROUND OF DEVELOPS AS THE SURFACE LOW AND
COLD FRONT MOVE IN FROM THE WEST. HOWEVER...WITH THE HIGH RAIN
CHANCES IN THE PUBLIC FORECAST OBLIGATED TO CARRY THUNDER THROUGH
THE DAY EVEN THOUGH IS SEEMS UNLIKELY THAT THIS WILL OCCUR. IT IS
NOW APPEARING THAT THE BEST CHANCE FOR STEADY RAINS WITH REDUCED
VISIBILITY AND IFR CEILINGS WILL OCCUR SATURDAY EVENING AS THE
MAIN SHORT WAVE TROUGH STARTS TO EJECT OUT AND INCREASES THE LIFT
IN THE VICINITY OF THE SURFACE LOW WHICH SHOULD BE OVER WESTERN
IOWA WITH THE WARM FRONT INTO THE AREA. OVERALL CONFIDENCE ON HOW
THIS IS GOING TO ALL PLAY OUT IS NOT HIGH SO NOT A LOT OF DETAILS
IN THE FORECAST YET.
&&
.HYDROLOGY...THROUGH SUNDAY
306 AM CDT SAT OCT 12 2012
QPF FORECAST STILL PROBLEMATIC...AGAIN DUE TO THE TRACK OF THE
STORM SYSTEM. MAIN FOCUS IS GOING TO BE ON THE DEFORMATION BAND ON
THE NORTH SIDE OF THE STORM SYSTEM TRACK...SINCE THIS IS GOING TO
HAVE THE BULK OF THE HEAVIER RAIN. THE LATEST 13.00Z ECMWF PROGS
A BAND OF 3-3.5 INCHES FROM PRAIRIE DU CHEIN NORTHEAST TOWARDS
WISCONSIN RAPIDS. THE 13.00Z GFS IS NOT TOO FAR OFF WITH A SIMILAR
BAND OF 2-4 INCHES IN ABOUT THE SAME PLACE. ON THE OTHER
HAND...THE FARTHER SOUTH AND FASTER 13.00Z NAM ENDS UP PRODUCING
THE HEAVY RAIN BAND ACROSS MUCH OF NORTHERN ILLINOIS. HAVE TAKEN A
COMPROMISE APPROACH BETWEEN THE TWO SCENARIOS...RESULTING IN AN
AREA OF 2 INCHES ACROSS THE SOUTHEASTERN 1/3 OF THE FORECAST AREA.
WILL HAVE TO SEE EVENTUALLY WHERE THE DEFORMATION BAND SETS UP TO
DETERMINE WHICH SCENARIO TO FOLLOW. NEEDLESS TO SAY...THE
LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN THE SEVERE
TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO FLOODING IS
ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
306 AM CDT SAT OCT 13 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1154 PM CDT FRI OCT 12 2012
.SHORT TERM...TONIGHT THROUGH MONDAY
345 PM CDT FRI OCT 12 2012
AT 3 PM...A 1030 MB CANADIAN HIGH WAS CENTERED OVER LOWER MICHIGAN.
THIS HIGH KEPT SKIES CLEAR ACROSS THE UPPER MISSISSIPPI RIVER VALLEY
THIS AFTERNOON. DESPITE THE SUNSHINE...TEMPERATURES HAVE ONLY
CLIMBED INTO THE 46 TO 54 DEGREE RANGE. FURTHER SOUTH...CLOUDS HAVE
BEEN RAPIDLY MOVING NORTH INTO SOUTHERN AND WESTERN IOWA. THESE
CLOUDS ARE ASSOCIATED WITH A SHORT WAVE TROUGH THAT IS MOVING
NORTHEAST OUT OF THE SOUTHERN PLAINS. THE 12.12Z MODELS CONTINUE TO
SHOW GOOD CONSISTENCY THAT AS THIS WAVE MOVES NORTHEAST TOWARD OUR
AREA THIS EVENING THERE WILL BE A RAPID INFLUX OF 875 TO 600 MB
MOISTURE INTO THE AREA. THIS WILL RESULT IN THE RAPID DEVELOPMENT OF
SHOWERS ACROSS SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND WESTERN
WISCONSIN BETWEEN 13.03Z AND 13.06Z...AND THEN ACROSS THE REMAINDER
OF THE AREA DURING THE OVERNIGHT. WITH 0-3KM MOST UNSTABLE OF 300 TO
900 J/KG ALONG AND SOUTH OF THE INTERSTATE 90 CORRIDOR...THERE
SHOULD ALSO BE SOME THUNDERSTORMS. WITH THE 1-7 KM BULK SHEAR LESS
THAN 20 KNOTS...NOT EXPECTING ANY OF THESE THUNDERSTORMS TO BECOME
SEVERE.
FOR SATURDAY INTO SUNDAY...THE 12.12Z MODELS ARE STARTING TO
DIVERGE. MUCH OF THIS IS HOW FAST THEY ARE EJECTING THE LOW
PRESSURE SYSTEM OUT OF THE SOUTHWEST UNITED STATES AND HOW IT
INTERACTS WITH THE NORTHERN STREAM TROUGH. THIS ULTIMATELY AFFECTS
THE CYCLOGENESIS THAT MANY OF THE PREVIOUS MODELS HAVE BEEN
SHOWING OVER THE PAST COUPLE OF DAYS OVER THE UPPER MISSISSIPPI
RIVER VALLEY. THE NAM/WRF IS THE SLOWEST AT MOVING THIS WAVE OUT
OF THE SOUTHERN PLAINS. AS A RESULT...IT HAS LITTLE PRECIPITATION
IN THE WAKE OF THE INITIAL SHORT WAVE TROUGH. BY THE TIME THIS
WAVE STARTS TO MOVE NORTHEAST...THE SURFACE LOW IS TOO SOUTHEAST
OF THE FORECAST AREA TO GET MUCH FROM THE LOW PRESSURE SYSTEM ON
SATURDAY NIGHT AND SUNDAY. HOWEVER THE 18Z NAM/WRF IS SHOWING THAT
ANOTHER WAVE WILL COME UP AND IT GENERATES PRECIPITATION DURING
THE AFTERNOON AND EVENING. THE GFS KEEPS SOME INTERACTION BETWEEN
THE NORTHERN AND SOUTHERN STREAMS. THIS RESULTS IN SOME WEAK
CYCLOGENESIS ACROSS THE REGION. AS A RESULT...IT CONTINUES THE
MOISTURE TRANSPORT INTO THE REGION AND THERE ARE SEVERAL ROUND
SHOWERS AND THUNDERSTORMS THAT MOVE THROUGH THE REGION.
FINALLY...THE ECMWF IS SIMILAR TO THE GFS FOR SATURDAY...BUT ON
SATURDAY NIGHT AND SUNDAY IT BRINGS THE SOUTHERN STREAM MUCH
FURTHER NORTHWEST...THEREFORE...IT LINGERS THE PRECIPITATION
THROUGHOUT THE DAY SUNDAY. THIS SOLUTION IS THE WETTEST FOR THE
FORECAST AREA. AS A RESULT...THE FORECAST CONFIDENCE HAS DECLINED
QUITE A BIT. DECIDED THE BEST OPTION WAS TO TRY AND GO WITH A
CONSENSUS FORECAST FOR NOW.
DESPITE THE DIFFERENCES IN THE MODELS...THEY ARE STILL IN AGREEMENT
THAT THERE WILL BE 500 TO 1000 J/KG OF ML CAPE ALONG AND SOUTH OF
THE INTERSTATE 90 CORRIDOR ON SATURDAY AFTERNOON AND EVENING. IN
ADDITION...THE 0-6 KM SHEAR WILL BE FAVORABLE FOR THE DEVELOPMENT OF
SUPERCELLS. THE 0-1 KM SHEAR IS STRONG ENOUGH FOR THE POSSIBILITY OF
TORNADOES. HOWEVER THIS WOULD BE HIGHLY DEPENDENT UPON WHETHER THE
CONVECTION CAN BECOME SURFACE BASED. THIS WOULD ALSO AFFECT OUR
WIND THREAT. WITH THE CAPES BEING SKINNY AND FREEZING LEVELS BEING
HIGH...THERE IS SOME UNCERTAINTY WHETHER THERE WILL BE ANY SEVERE
HAIL. FINALLY...THE CYCLOGENESIS LOOKS MUCH MORE WEAKER. THIS
MEANS THAT THE DYNAMICS ARE MUCH WEAKER. IF SEVERE WEATHER HAPPENS
TO DEVELOP...THE GFS WOULD HAVE ITS THREAT OF SEVERE WEATHER FROM 4 TO
9 PM. MEANWHILE THE NAM/WRF WOULD SUGGEST THAT THE THREAT WOULD
EXIST FROM 12 PM TO 6 PM.
ON MONDAY...THE MAIN FORECAST QUESTION IS HOW WARM WILL WE GET.
THE GFS 850 TEMPERATURES ARE ABOUT 6C COLDER THAN THE NAM/WRF AND
ECMWF. AS RESULT...TOOK THE CONSALL AND BLENDED IT WITH THE ECMWF
TO TREND TOWARD A WARMER SOLUTION.
.LONG TERM...MONDAY NIGHT THROUGH THURSDAY
345 PM CDT FRI OCT 12 2012
LIKE THE PAST COUPLE OF DAYS...THE 12.12Z MODELS ARE IN FAIRLY
GOOD AGREEMENT THAT A BROAD TROUGH DEVELOP ACROSS THE CENTRAL AND
EASTERN UNITED STATES. THE ONLY QUESTION IS HOW DEEP WILL THIS
TROUGH GET AND HOW MUCH COLD AIR IT WILL BRING SOUTHWARD INTO THE
REGION. SINCE THERE CONTINUES TO BE SOME UNCERTAINTY ON
THIS...JUST WENT WITH THE CONSALL.
&&
.AVIATION...THROUGH 06Z SUNDAY
1154 PM CDT FRI OCT 12 2012
FIRST ROUND OF SHOWERS MOVING ACROSS THE AREA NOW WITHOUT ANY
VISIBILITY RESTRICTIONS AND VFR CEILINGS. CONCERNS BASED ON THE
13.00Z NAM AND 12.12Z MESO MODELS IS JUST HOW MUCH RAIN IS GOING
TO DEVELOP OVERNIGHT INTO SATURDAY. REGIONAL RADARS NOT SHOWING A
WHOLE LOT GOING ON TO THE SOUTH AT THIS TIME. HOWEVER...AS THE LOW
LEVEL JET INTERACTS WITH THE WARM FRONT/DEW POINT BOUNDARY ACROSS
CENTRAL IOWA...EXPECT TO SEE AN INCREASE IN THE COVERAGE. THIS MAY
NOT HAPPEN UNTIL LATE TONIGHT OR EARLY SATURDAY MORNING AS INITIAL
DEVELOPMENT WOULD BE TO THE SOUTH WITH THE ACTIVITY THEN MOVING
NORTH. AS A RESULT...PLAN TO JUST STAY WITH VICINITY THUNDER OR
SHOWERS THROUGH THE NIGHT. THEN EXPECT THE ACTIVITY THAT DEVELOPS
TO REDUCE THE VISIBILITY FOR A FEW HOURS SATURDAY MORNING WITH
EITHER VFR OR MVFR BUT TAKING THE CEILINGS DOWN TO IFR. THE
NAM...HI-RES ARW...NMM AND HRRR ALL THEN SHOW THIS ACTIVITY MOVING
OFF TO THE EAST WITH A BREAK DURING THE LATE MORNING INTO THE
AFTERNOON BEFORE THE NEXT ROUND OF DEVELOPS AS THE SURFACE LOW AND
COLD FRONT MOVE IN FROM THE WEST. HOWEVER...WITH THE HIGH RAIN
CHANCES IN THE PUBLIC FORECAST OBLIGATED TO CARRY THUNDER THROUGH
THE DAY EVEN THOUGH IS SEEMS UNLIKELY THAT THIS WILL OCCUR. IT IS
NOW APPEARING THAT THE BEST CHANCE FOR STEADY RAINS WITH REDUCED
VISIBILITY AND IFR CEILINGS WILL OCCUR SATURDAY EVENING AS THE
MAIN SHORT WAVE TROUGH STARTS TO EJECT OUT AND INCREASES THE LIFT
IN THE VICINITY OF THE SURFACE LOW WHICH SHOULD BE OVER WESTERN
IOWA WITH THE WARM FRONT INTO THE AREA. OVERALL CONFIDENCE ON HOW
THIS IS GOING TO ALL PLAY OUT IS NOT HIGH SO NOT A LOT OF DETAILS
IN THE FORECAST YET.
&&
.HYDROLOGY...TONIGHT THROUGH SUNDAY
258 AM CDT FRI OCT 12 2012
QPF WISE FOR THE TONIGHT THROUGH SUNDAY MORNING SYSTEM...REALLY HARD
TO SAY. THE MAXIMUM AREA SHOULD BE OVER THE SOUTHEASTERN 1/3 OF THE
FORECAST AREA...WHERE THE LONGEST PERIOD OF 850MB MOISTURE TRANSPORT
NOSES IN AND THEN GETS HIT BY THE DEFORMATION ON THE BACK SIDE OF
THE SYSTEM. PRECIPITABLE WATER VALUES CLIMB TO AROUND 1.5 INCHES OR
200-250 PERCENT OF NORMAL TONIGHT AND HOVER AROUND THERE INTO SUNDAY
MORNING. POTENTIAL IS DEFINITELY THERE TO GET 1 TO 2 INCHES FOR THE
ENTIRE TIME PERIOD...AS SUGGESTED BY HPC FORECASTS AND SREF
PROBABILITIES...WITH LOCALLY HIGHER AMOUNTS DUE TO THE CONVECTIVE
NATURE. IN FACT...THE LATEST 12.00Z ECMWF HAS UPWARDS OF 3-3.5
INCHES. THE LANDSCAPE AND RIVERS REALLY COULD USE THIS RAIN GIVEN
THE SEVERE TO EXTREME DROUGHT CONDITIONS IN PLACE. THEREFORE...NO
FLOODING IS ANTICIPATED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
345 PM CDT FRI OCT 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS NEW YORK NY
430 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION TODAY...AND
PASS TONIGHT. GUSTY WINDS WILL USHER IN A COOLER AIRMASS FOR
TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT
THROUGH THURSDAY...BEFORE MOVING EAST OF THE AREA THURSDAY NIGHT.
A STORM SYSTEM MAY IMPACT THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
THE COLD FRONT WAS APPROACHING THE OH/PA BORDER AT 3AM. CWA WILL
REMAIN IN THE WARM SECTOR BEFORE THE FRONT ARRIVES. TEMPS MILD THIS
MRNG AND WITH CLOUDS OVERSPREADING WRN ZONES...TEMPS THERE WILL
REMAIN STEADY OR RISE BEFORE SUNRISE. SIMILAR TEMP SCENARIO ALONG
THE COASTS WITH THE WIND COMING IN OFF THE WATER. PCPN WILL STAY W
OF THE CWA CLOSER TO THE UPR FORCING THRU THE MRNG HRS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM TUESDAY/...
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN THE
DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV.
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW AND
THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
TEMPS START OFF SLIGHTLY BELOW NORMAL ON TUE...GRADUALLY WARMING
TO A FEW DEGREES ABOVE NORMAL BY THU.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES FROM THE WEST TODAY BEFORE PASSING THROUGH
LATE IN THE DAY INTO THIS EVENING.
S/SW WINDS AVERAGING MOSTLY 10-15 KT WITH GUSTS AROUND 20 KT BECOME
SLIGHTLY LIGHTER THIS AFTERNOON AND LESS GUSTY. WIND SHIFT TO NW
ARRIVES CLOSE TO MIDNIGHT.
PRIMARILY VFR. CIGS COULD POSSIBLY PREVAIL 1500-3000 FT DURING THE
TIME WHERE TEMPO GROUPS WITH SHRA ARE IN THE TAFS. AN ISOLATED
THUNDERSTORM IS ALSO POSSIBLE DURING THESE TEMPO PERIODS...BUT NOT
ENOUGH PROBABILITY AND COVERAGE TO MENTION IN THE FORECAST AT THIS
TIME. SHOWERS WILL ALSO BE POSSIBLE A COUPLE OF HOURS BEFORE THE
TIME INDICATED IN TAFS.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE THROUGH
15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KHPN FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL.
KISP FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL AFTER 16Z.
OUTLOOK FOR 06Z TUE THROUGH FRIDAY...
.MONDAY NIGHT...VFR. OCCASIONAL NW GUSTS AROUND 20 KT.
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
322 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION TODAY...AND
PASS TONIGHT. GUSTY WINDS WILL USHER IN A COOLER AIRMASS FOR
TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT
THROUGH THURSDAY...BEFORE MOVING EAST OF THE AREA THURSDAY NIGHT.
A STORM SYSTEM MAY IMPACT THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
THE COLD FRONT WAS APPROACHING THE OH/PA BORDER AT 3AM. CWA WILL
REMAIN IN THE WARM SECTOR BEFORE THE FRONT ARRIVES. TEMPS MILD THIS
MRNG AND WITH CLOUDS OVERSPREADING WRN ZONES...TEMPS THERE WILL
REMAIN STEADY OR RISE BEFORE SUNRISE. SIMILAR TEMP SCENARIO ALONG
THE COASTS WITH THE WIND COMING IN OFF THE WATER. PCPN WILL STAY W
OF THE CWA CLOSER TO THE UPR FORCING THRU THE MRNG HRS.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM TUESDAY/...
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN THE
DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV.
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW AND
THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
TEMPS START OFF SLIGHTLY BELOW NORMAL ON TUE...GRADUALLY WARMING
TO A FEW DEGREES ABOVE NORMAL BY THU.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES FROM THE WEST TODAY BEFORE PASSING THROUGH
LATE IN THE DAY INTO THIS EVENING.
S/SW WINDS AVERAGING MOSTLY 10-15 KTS BECOME SLIGHTLY LIGHTER THIS
AFTERNOON AND LESS GUSTY. WIND SHIFT TO NW ARRIVES CLOSE TO
MIDNIGHT.
PRIMARILY VFR. CIGS COULD POSSIBLY PREVAIL 1500-3000 FT DURING THE
TIME WHERE TEMPO GROUPS WITH SHRA ARE IN THE TAFS. AN ISOLATED
THUNDERSTORM IS ALSO POSSIBLE DURING THESE TEMPO PERIODS...BUT NOT
ENOUGH PROBABILITY AND COVERAGE TO MENTION IN THE FORECAST AT THIS
TIME.
OUTLOOK FOR 06Z TUE THROUGH FRIDAY...
.MONDAY NIGHT...VFR. OCCASIONAL NW GUSTS AROUND 20 KT.
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
201 AM EDT MON OCT 15 2012
.PREV DISCUSSION... /ISSUED 954 PM EDT SUN OCT 14 2012/
UPDATE...
HAVE MADE SEVERAL MINOR TWEAKS TO GRIDS...MOSTLY TO UPDATE FOR
CURRENT TRENDS BUT ALSO TO TWEAK POPS/WX GRIDS. INITIALLY
DECREASED POPS ESPECIALLY ACROSS THE METRO AREA TO ACCOUNT FOR THE
MOVEMENT OF THE FRONT...THEN INCREASED POPS ACROSS THE NORTH AS
CONVECTION FILLS IN. SPC MESOANALYSIS BARELY BRINGS 100 J/KG
SBCAPE INTO THE AREA AND RAP FORECAST NOT REALLY ANY BETTER...SO
CONTINUED TREND OF LIMITING THUNDER WORDING TO SLIGHT CHANCE WHILE
KEEPING OVERALL POPS LIKELY TO CATEGORICAL. ADDED PATCHY FOG
WORDING AS WELL. WILL BE KEEPING AN EYE ON CONVECTION ALONG THE
FRONT AS CELLS HAVE SHOWN SIGNS OF ROTATION...BUT WITH THE LACK OF
INSTABILITY DO NOT EXPECT ENOUGH UPDRAFTS TO CAUSE CONCERN ACROSS
OUR AREA. UPDATED PRODUCTS WILL BE OUT SHORTLY.
TDP
PREV DISCUSSION... /ISSUED 745 PM EDT SUN OCT 14 2012/
PREV DISCUSSION... /ISSUED 346 PM EDT SUN OCT 14 2012/
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
VARIABLE CLOUDINESS PREVAILS AT THIS TIME WITH SCATTERED SHOWERS
AND ISOLATED TSTMS IN EAST CENTRAL GA DUE TO ATLANTIC MOISTURE
INTERACTING WITH THE DIURNAL HEATING. OTHERWISE...A LINE OF SHOWERS
AND A FEW TSTMS IN NORTH AL WAS WELL AHEAD OF THE COLD FRONT IN THE
MS RIVER VALLEY. STILL EXPECTING MEASURABLE RAIN OVER NORTHWEST GA
AFTER 800 PM IN ADVANCE OF THE APPROACHING COLD FRONT AND AFTER
MIDNIGHT IN THE ATLANTA AND ATHENS METRO AREAS. THE SHOWERS AND A FEW
TSTMS WILL DIMINISH BY SUNRISE OVER NORTH GA AND CONTINUE MOVING
THROUGH CENTRAL GA ON MONDAY MORNING ENDING BY AFTERNOON. A
SOUTHWEST FLOW ALOFT IN ADVANCE OF THE FRONT WILL ALLOW MODERATE
AMOUNTS OF GULF MOISTURE...PWS AROUND 1.6 INCHES...TO FLOW INTO THE
STATE WITH WEAK INSTABILITY...CAPES AROUND 1000 J/KG. CONSEQUENTLY
EXPECTING NUMEROUS SHOWERS WITH A FEW TSTMS PRIOR TO AND WITH THE
FRONTAL PASSAGE. QPF AMOUNTS OF AROUND ONE HALF INCH CAN BE
ANTICIPATED. HIGH PRESSURE WILL BUILD OVER THE FORECAST AREA ON
MONDAY AFTERNOON WITH A BREEZY NORTHWEST FLOW. COLD AIR ADVECTION
WILL CAUSE MIN TEMPS TO BE AROUND 5 DEGREES BELOW NORMAL FOR MONDAY
NIGHT.
CONTINUED TO LEAN TOWARD THE MET MOS GUIDANCE MORE FOR WEATHER
ELEMENTS THROUGH THE FIRST 18 HOURS BASED ON TIMING OF CONVECTION.
USED A BLEND OF MET/MAV MOS GUIDANCE IN THE 18 TO 36 HOUR RANGE.
16
LONG TERM /TUESDAY THROUGH SUNDAY/...
BIG STORY THROUGH THE LONG TERM CONTINUES TO BE THE COLD FRONT
ANTICIPATED TO PUSH THROUGH THE TENNESSEE VALLEY AND INTO
NORTHWEST GEORGIA EARLY THURSDAY. LATEST ECMWF MORE IN ALIGNMENT
WITH THE GFS WITH REGARDS TO INITIAL TIMING AND STRENGTH...THOUGH
IT CONTINUES TO BE MORE AGGRESSIVE WITH SECONDARY LOW DEVELOPING
OVER EASTERN GEORGIA AND THE CAROLINAS EARLY FRIDAY. THAT BEING
SAID...THE 12Z ECMWF DOES APPEAR LESS ENTHUSIASTIC WITH THE
IMPACTS TO OUR CWA THAN THE PREVIOUS RUNS. GIVEN THE HIGH
UNCERTAINTY THAT SURROUNDS THIS EVENT...HAVE ONLY MADE MINOR
CHANGES TO THE EXTENDED FORECAST. HAVE GONE AHEAD AND INCREASED
POPS FROM SLIGHT CHANCE TO CHANCE ACROSS EASTERN GEORGIA EARLY
FRIDAY DUE TO A SLIGHTLY BETTER MODEL CONSENSUS ON THE PRECIP
DURING THAT TIME. OTHERWISE...HAVE GENERALLY ONLY MADE CHANGES TO
TEMPERATURES AND DEWPOINTS...THOUGH FAIRLY MINOR. THE PREVIOUS
DISCUSSION IS INCLUDED BELOW FOR REFERENCE.
31
/ISSUED 419 AM EDT SUN OCT 14 2012/
IN WAKE OF FROPA SUNDAY NIGHT INTO MONDAY...HIGH PRESSURE WILL
BUILD INTO THE AREA AND ALLOW FOR DRY CONDITIONS INTO MIDWEEK. THE
MAIN FORECAST CONCERN FOR THE LONG TERM WILL BE FROM A SECOND COLD
FRONT PROGGED TO INFLUENCE THE FORECAST AREA ON THURSDAY INTO
FRIDAY. MODEL SOLUTIONS CONTINUE TO HAVE SIGNIFICANT DISCREPANCIES
ON THE TIMING AND PRECIP POTENTIAL WITH THIS FEATURE. THE LATEST
GFS STILL SUGGESTS A MOSTLY DRY PASSAGE COMPARED TO THE
ECMWF...WHICH CONTRASTINGLY DEVELOPS A SECONDARY LOW OVER THE
SOUTHEAST CONUS AND DRAWS IN A MUCH MORE EXPANSIVE MOISTURE FIELD.
THE GFS ALSO IS MUCH MORE PROGRESSIVE THAN THE ECMWF...PUSHING THE
FRONT THROUGH ON THURSDAY MORNING AND AFTERNOON INSTEAD OF THE
LATTER THURSDAY NIGHT INTO FRIDAY SOLUTION. WILL THEREFORE
CONTINUE TO GO WITH A GENERAL BLEND AND INCLUDE SLIGHT TO CHANCE
POPS THROUGH THE PERIOD AND HAVE ISOLATED THUNDER POTENTIAL DURING
THURSDAY INTO THURSDAY NIGHT.
BY NEXT WEEKEND...THE GFS HAS THE UPPER TROUGH EXITING THE
REGION...WHILE THE ECMWF LINGERS AN UPPER CLOSED LOW OVER THE GREAT
LAKES AND HAS THE MAJORITY OF HIGH RH VALUES NORTH OF GEORGIA. IF
THE CLOSED LOW SOLUTION PANS OUT THEN ANY LOBES OF VORTICITY
TRACKING ALONG THE TROUGH WOULD ENHANCE CLOUD COVERAGE OR PRECIP
POTENTIAL. DUE TO THIS LARGE VARIATION AMONG GUIDANCE...WILL GO WITH
A DRY FORECAST THROUGH THE WEEKEND AND WILL MAKE ADJUSTMENTS ONCE
CONFIDENCE INCREASES WITH WEIGHING IN ON MODEL CONSISTENCY OR
CONSENSUS.
GENERALLY STUCK A BIT WARMER THAN MEX GUIDANCE FOR TEMPS AS THE
ECMWF HAS A WARMER SOLUTION THROUGH THE MAJORITY OF THE LONG TERM.
BAKER
&&
.AVIATION...
06Z UPDATE...
MONITORING WHAT IS NOW A BKN LINE OF SHRA AND EMBEDDED
THUNDERSTORMS MOVING INTO NW GEORGIA. CURRENT TIMING HAS LINE
APPROACHING OUTER MOST ATL AREA TERMINALS AT 08Z AND SLOWLY
PUSHING THROUGH BY 12Z. HAVE PREDOMINANT SHRA WITH VCTS AND WILL
MONITOR FOR POSSIBLE TEMPO TSRA AS LINE APPROACHES. LOW CLOUDS TO
FILTER IN FRO A BRIEF TIME BEHIND LINE OF SHOWERS WITH IFR NOW
LIKELY THROUGH 14Z. VFR TO TAKE HOLD AFTER 16Z HOWEVER WITH GUSTY
NW WINDS TO 25 KTS.
//ATL CONFIDENCE...06Z UPDATE...
HIGH ON SHRA OVERNIGHT...LOW ON POSSIBILITY OF TSRA.
HIGH ON CIGS OVERNIGHT.
HIGH ON WINDS MONDAY.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 76 46 74 48 / 50 0 5 10
ATLANTA 74 49 72 52 / 10 0 5 10
BLAIRSVILLE 67 41 69 42 / 10 0 5 10
CARTERSVILLE 73 42 73 46 / 10 0 5 10
COLUMBUS 80 50 76 55 / 30 0 5 10
GAINESVILLE 74 47 70 50 / 10 0 5 10
MACON 82 47 78 48 / 30 0 5 10
ROME 73 42 74 47 / 10 0 5 10
PEACHTREE CITY 77 42 75 46 / 10 0 5 10
VIDALIA 83 54 79 56 / 30 0 5 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....BAKER
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1122 PM MDT SUN OCT 14 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 1251 PM MDT SUN OCT 14 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW RIDGE ACROSS NORTHERN
ROCKIES WITH LARGE SCALE TROUGH STILL IN PLACE OVER UPPER
MISSISSIPPI RIVER VALLEY. NW FLOW REMAINS IN PLACE ACROSS THE PLAINS
BETWEEN THESE FEATURES. AT THE SURFACE HIGH PRESSURE IS IN PLACE
OVER EASTERN COLORADO...WITH A LARGE AREA OF LOW PRESSURE OVER THE
CENTRAL MISSISSIPPI RIVER VALLEY. BETWEEN THESE FEATURES...TIGHTENED
PRESSURE GRADIENT OVER THE CWA HAS LED TO GUSTY WINDS BETWEEN 25 AND
30 MPH. THESE WINDS SHOULD DIMINISH AROUND SUNSET WITH AN END OF
DAYTIME MIXING.
A SURFACE TROUGH WILL DEVELOP ALONG THE KS/CO STATE LINE BY EARLY
MONDAY MORNING...WITH GRADIENT RELAXING ACROSS THE CWA. RESULT WILL
BE DEVELOPMENT OF LIGHT SW WINDS AND WAA AT H85. DESPITE WARMER
TEMPS ALOFT...CLEAR SKIES AND CALM WINDS WILL SUPPORT GOOD
RADIATIONAL COOLING OVERNIGHT. MOST LOCATIONS SHOULD SEE LOWS IN THE
LOW TO MID 40S...AND UPPER 30S AT TRADITIONAL COLD SPOTS. H5 RIDGE
WILL CONTINUE TO BUILD EAST OVERNIGHT AND SHOULD BE OVER CWA BY
EARLY MONDAY MORNING. WITH LARGE SCALE SUBSIDENCE IN PLACE MOSTLY
CLEAR SKIES AND DRY CONDITIONS SHOULD PREVAIL THROUGH MONDAY.
AIR MASS WILL CONTINUE TO MODERATE THROUGH MONDAY AFTERNOON...WITH
H85 TEMPS ABOUT 5-7C WARMER THAN THIS AFTERNOON. THIS SHOULD
SUPPORT AFTERNOON HIGH TEMPERATURES IN THE UPPER 70S TO LOW 80S
ACROSS THE CWA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 217 PM MDT SUN OCT 14 2012
LATE MONDAY NIGHT AN UPPER LEVEL SHORT WAVE TROUGH AND SURFACE
TROUGH/WEAK COLD FRONT WILL MOVE THROUGH THE NORTHEAST HALF OF THE
AREA. SOUNDINGS SHOW LITTLE MOISTURE TO WORK WITH SO AM ONLY
ANTICIPATING A FEW CLOUDS DURING THE OVERNIGHT HOURS.
TUESDAY A SHORT WAVE RIDGE AND SURFACE HIGH FOLLOW THE SURFACE
TROUGH INTO THE AREA. WINDS TURN TO THE SOUTHWEST AS THE RIDGE
BUILDS IN CAUSING TEMPERATURES TO WARM WELL ABOVE NORMAL.
TUESDAY NIGHT A STRONGER COLD FRONT MOVES INTO THE AREA DURING THE
EVENING...AND EXITS THE AREA DURING THE OVERNIGHT HOURS. THERE IS
SOME 700-500MB MOISTURE TO WORK WITH...HOWEVER A DRY LAYER WILL
STILL EXIST BELOW 700MB. MODELS DISAGREE WITH THE 500 AND 300MB
JET PLACEMENT BEHIND THE FRONT...BUT THE MAJORITY OF THE MODELS
INDICATE THE LEFT EXIT REGION OF THE JET MAY BE IN A FAVORABLE
LOCATION FOR THE NORTHERN HALF OF THE AREA TO RECEIVE PRECIP. THE
DOWNFALL IS THE DRY LAYER PRESENT BETWEEN 700MB AND THE SURFACE
WILL PREVENT ANY PRECIP THAT MAY FORM FROM REACHING THE GROUND.
UPPER LEVEL LIFT IMPROVES BEHIND THE FRONT AS A DEEPENING LONG
WAVE TROUGH MOVES IN...BUT SOUNDINGS SHOW THE ENVIRONMENT DRYING
OUT BEHIND THE FRONT. IN ADDITION GEFS AND SREF MEMBERS PLACE THE
PRECIP NORTH OF THE TRI-STATE AREA. WITH UNCERTAINTIES REGARDING THE
AMOUNT OF MOISTURE AVAILABLE WILL ONLY PLACE IN SILENT CHANCES FOR
THE AREA.
FOR THE WEDNESDAY THROUGH SUNDAY PERIOD THE FORECAST WILL CONTINUE
TO BE DRY. THE LONG WAVE TROUGH WILL CONTINUE TO DEEPEN WEDNESDAY
AS IT PROGRESSES EAST...BECOMING A CLOSED LOW OVER THE UPPER
MIDWEST AND LINGERING THERE THROUGH SATURDAY. MEANWHILE NORTHWEST
WINDS WILL STRENGTHEN WEDNESDAY BEHIND THE COLD FRONT FROM TUESDAY
NIGHT. THURSDAY THE WINDS WILL STRENGTHEN FURTHER DUE TO 40-50KT
850MB WINDS WINDS MIXING DOWN. WEDNESDAY AND THURSDAY AFTERNOON
THE FIRE DANGER WILL INCREASE ACROSS THE AREA DUE TO WINDS GUSTING
TO 35 MPH ON WEDNESDAY...45 MPH ON THURSDAY WITH RELATIVE
HUMIDITIES AROUND 20 PERCENT BOTH DAYS. OTHERWISE TEMPERATURES
WILL BE NEAR TO BELOW NORMAL THROUGH FRIDAY THEN ABOVE NORMAL
TEMPERATURES RETURN FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1107 PM MDT SUN OCT 14 2012
VFR CONDITIONS COMBINED WITH LIGHT AND VARIABLE WIND WILL PERSIST FOR
THE NEXT 24 HOURS AT KGLD AND KMCK AS HIGH PRESSURE DRIFTS EAST
AND IS REPLACED BY WEAK LOW PRESSURE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...FS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 AM EDT MON OCT 15 2012
.UPDATE...
ISSUED AT 625 PM EDT SUN OCT 14 2012
DID AN EARLY UPDATE THIS EVENING TO ACCOUNT FOR A MORE EXTENSIVE
PERIOD OF RAIN ACROSS THE EASTERN HALF OF THE FORECAST AREA. THE LOW
OVER NRN MICHIGAN WILL BE SLOW TO MOVE NORTHEAST TONIGHT AS THE
UPPER TROUGH BECOMES NEGATIVELY TILTED. THIS WILL ALLOW FOR
DEEPENING TO CONTINUE THIS EVENING WITH A TROWAL TYPE FEATURE
EVENTUALLY DEVELOPING AS THE LOW OCCLUDES OUT. THIS TROWAL WILL HELP
TO STRENGTHEN THE FRONTOGENETIC FORCING TO THE NORTHWEST OF THE LOW
AND ALLOW FOR PCPN TO PERSIST FOR MUCH OF THE OVERNIGHT ACROSS THE
EASTERN 1/3 OF UPPER MICHIGAN. THE LATEST RAP RUN CLEARLY SHOWS PCPN
HANGING ON FOR MUCH OF THE NIGHT AT ERY. MEANWHILE...NORTH CENTRAL
UPPER MICHIGAN IS SEEING THE TERRAIN LIGHT UP DUE TO THE DEEPER
MOISTURE AND SLIGHTLY MORE NORTHERLY PBL FLOW. WITH ALL OF THIS
SAID...HAVE OPTED TO RAISE POPS TO CATEGORICAL THIS EVENING ACROSS
N-CENTRAL UPPER MICHIGAN AND THEN GRADUALLY DIMINISH OVERNIGHT AS
DRIER AIR MOVES IN. WILL ALSO MAINTAIN CATEGORICAL POPS ALL NIGHT
ACROSS THE EAST. SOME PLACES ACROSS THE EASTERN HALF OF UPPER MI
WILL SEE OVER 2 INCHES OF RAIN BY MONDAY MORNING. MANY PLACES ARE
ALREADY WELL OVER 1 INCH TODAY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 351 PM EDT SUN OCT 14 2012
CURRENT /18Z/ ANALYSIS SHOWS A STRONG UPPER SHORTWAVE TROUGH
STRETCHING FROM N MN TO N IL...WITH AN ELONGATED 998MB SFC LOW FROM
N IL TO NE LOWER MI. THE NE PORTION OF THE SFC LOW SHOULD BEGIN TO
DOMINATE AS THE DRY SLOT IS MOVING OVER REDUCING STATIC
STABILITY...AND SINCE THE UPPER SHORTWAVE FOCUS OVER THIS
AREA...FAVORING CYCLOGENESIS. THE 850MB LOW IS JUST SE OF
MENOMINEE...WITH A LARGE SHIELD OF MODERATE TO HEAVY RAINFALL ON THE
NW SIDE OF THIS FEATURE. THE NW EXTENT OF THE RAIN SHIELD EXTENDS
FROM NEAR ARX...TO RHI...TO CRYSTAL FALLS...TO MQT...TO E LAKE
SUPERIOR. AS NOTED BEFORE...HEAVY RAIN HAS BEEN REPORTED...MAINLY
CLOSER TO LAKE MICHIGAN WITH RAIN AMOUNTS UP TO AN INCH SO FAR OVER
SCENTRAL UPPER M. ADDITIONALLY...UPSLOPE FLOW AND AMPLE LOW LEVEL
MOISTURE IS BRINGING DRIZZLE/BR AND RAIN SHOWERS TO MUCH OF THE REST
OF THE CWA. ON THE NW SIDE OF THE SYSTEM IS A SFC RIDGE THAT WILL
MOVE INTO THE CWA TOMORROW.
THE DEFORMATION/FGEN FORCING AXIS AND ASSOCIATED PRECIP IS NOT
EXPECTED TO MOVE MUCH MORE NW THAN WHAT IT IS NOW SINCE IT IS
PIVOTING AROUND THE 850MB LOW...AND IS ALREADY STARTING TO PUSH
SLOWLY E ALONG THE WI BORDER. AS THE UPPER SHORTWAVE MOVES TO THE
ERN CWA BY 06Z MON...THE SFC LOW WILL MOVE TO LAKE HURON AND THE
BAND OF SYNOPTIC PRECIP WILL MOVE TO THE FAR ERN CWA OR JUST E OF
THE CWA. AS MODERATELY COLD 850MB TEMPS OF -2C TO -4C MOVES OVER
LAKE SUPERIOR BY 06Z MON...EXPECT SOME ISOLATED TO SCATTERED LAKE
EFFECT RAIN SHOWERS AND DRIZZLE FROM THE NLY UPSLOPE FLOW. BY TIME
THE COLDER AIR MOVES INTO THE NEAR SFC LAYER...LOW LOW LEVEL
MOISTURE WILL BE PRESENT...SO NOW SNOW IS EXPECTED. THE LAKE EFFECT
PRECIP WILL TAPER OFF FROM W TO E AS DRIER LOW LEVEL AIR MOVES IN
WITH THE SFC RIDGE. THE RIDGE WILL MOVE TO NEAR IWD BY 18Z
MON...THEN TO THE CENTER OF THE CWA BY 00Z TUE...BRINGING A RETURN
OF WARMER 850MB TEMPS UP TO 4C.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 449 PM EDT SUN OCT 14 2012
MONDAY NIGHT INTO TUE...MDLS WERE IN REASONABLE AGREEMENT WITH THE
MID LEVEL AND SFC RIDGE SLIDING QUICKLY TO THE EAST AND A MAINLY
ZONAL PATTERN ACROSS THE NRN CONUS. WAA/ISENTROPIC LIFT AHEAD OF THE
NEXT SHORTWAVE TROUGH WILL BRING INCREASING CLOUDS ACROSS THE AREA
MON NIGHT WITH RAIN CHANCES SPREADING INTO WRN UPPER MI. MODERATE TO
STRONG 300K ASCENT WITH MOISTURE INFLOW BRINGING PWAT VALUES TO
AROUND AN INCH SUPPORT LIKELY POPS OVER MOST OF THE CWA...ESPECIALLY
FOR THE CNTRL AND EAST EVEN IF QPF VALUES ARE ONLY A TENTH OF TWO.
EXPECT THAT THE PCPN WILL TAPER OFF IN THE WEST HALF BY AFTERNOON
AND THE EAST LATE.
TUE NIGHT AND WED...MDLS SUGGEST THAT AS STRONG UPPER LEVEL JET
ENERGY INTO THE PAC NW DIGS TO THE SE A BROAD MID/UPPER LEVEL TROUGH
WILL DEVELOP OVER THE PLAINS. WAA WILL INCREASE AHEAD OF A SFC
TROUGH EXTENDED FROM SRN MANITOBA INTO WRN MN BY 12Z/WED. THE ECMWF
WAS PREFERRED WITH A SLIGHTLY LATER ARRIVAL OF ANY PCPN INTO UPPER
MI AS THE STRONGER FORCING WITH THE JET AND MID LEVEL LOW REMAIN TO
THE SW OF UPPER MI. EVEN THOUGH 850 MB TEMPS CLIMB TO AROUND
10C...INCREASING CLOUDS SHOULD LIMIT MAX READINGS TO AROUND 60.
THU-SUN...MDLS DIFFERENCES BECOME MORE SIGNFICANT AS THE GFS/GEFS
BECOME MORE PROGRESSIVE BY NEXT WEEKEND COMPARED TO THE 00Z ECMWF
AND ASSOCIATED ENSEMBLES. EVEN THOUGH THE 12Z ECMWF HAS TRENDED MORE
TOWARD THE GFS...CONFIDENCE IN THE OVERALL PATTERN AND DETAILS IS
LOW. EXPECT THE BEST CHANCE OF PCPN FROM WED NIGHT INTO THU AS THE
SFC TROUGH AND MOISTURE AXIS LIFTS INTO THE REGION. BEYOND THU...THE
POSITION OF THE DRY SLOT OR ADDITIONAL WEAK IMPULSES AROUND THE MID
LEVEL LOW IS VERY UNCERTAIN. ABOVE NORMAL TEMPS WILL COOL BACK AGAIN
AOB SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 143 AM EDT MON OCT 15 2012
THE RAIN IS STARTING TO MOVE EAST...AND THE TERMINALS ARE CURRENTLY
MVFR. EXPECT CONDITIONS TO IMPROVE TO VFR AT IWD AND CMX BY MORNING
WITH CONTINUED VFR CONDITIONS AT THOSE SITES THROUGH THE DAY. AT
SAW...THE N WINDS SHOULD ALLOW FOR MVFR CIGS TO CONTINUE THROUGH
MONDAY MORNING BEFORE SCOURING OUT BY MONDAY AFTN. COULD SEE AN MVFR
VSBY RESTRICTION AT SAW WITH ANY RAIN...BUT THE HEAVIEST RAIN IS
LIKELY OVER SO EVEN THAT IS UNLIKELY. GUSTY N WINDS WILL PERSIST AT
SAW AND CMX OVERNIGHT WITH A FEW GUSTS CLOSE TO 30 KT POSSIBLE.
HOWEVER...THOSE WINDS SHOULD SUBSIDE AS THE LOW MOVES NORTHEAST.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 301 PM EDT SUN OCT 14 2012
EXPECT N TO NE WINDS TO INCREASE INTO TONIGHT AS A LOW PRESSURE
SYSTEM OVER NORTHERN LAKE MICHIGAN LIFTS NE TO LAKE HURON BY LATE
TONIGHT. LATE THIS AFTERNOON AND EARLY EVENING...WINDS SHOULD BE IN
THE 20-30KT RANGE OVER PRIMARILY THE CENTRAL AND ERN PORTIONS OF
LAKE SUPERIOR. WINDS WILL BE LIGHTER OVER THE FAR WRN LAKE. EXPECT
NORTHERLY GALES TO DEVELOP OVER ROUGHLY THE EASTERN HALF OF LAKE
SUPERIOR LATE THIS EVENING AND THEN CONTINUE INTO MONDAY MORNING AS
THE LOW RAPIDLY DEEPENS AND MOVES EAST OF THE AREA AND HIGH PRESSURE
PUSHES IN FROM THE WEST. WINDS SETTLE DOWN MONDAY AFTERNOON AND
MONDAY NIGHT WITH ARRIVAL OF HIGH PRESSURE. ANOTHER LOW PRESSURE
SYSTEM WILL MOVE INTO THE UPPER GREAT LAKES ON WEDNESDAY INTO
WEDNESDAY NIGHT. SOUTH WINDS AHEAD OF THIS LOW COULD BRIEFLY REACH
GALES TO 35 KTS OVER ERN LAKE SUPERIOR TUE AFTERNOON.
OTHERWISE...WINDS IN THE VICINITY OF THE LOW SHOULD REMAIN LESS THAN
20 KTS WEDNESDAY THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EDT THIS MORNING FOR LSZ249>251-266-267.
LAKE MICHIGAN...
GALE WARNING UNTIL 11 AM EDT THIS MORNING FOR LMZ221-250.
&&
$$
UPDATE...MRD
SHORT TERM...TITUS
LONG TERM...JLB
AVIATION...MRD
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
332 AM CDT MON OCT 15 2012
.DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE HIGH TEMPERATURES OVER THE NEXT
COUPLE DAYS AND PRECIPITATION CHANCES TUESDAY NIGHT INTO MID
WEEK.
LATEST WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWS THE NATIONS
MID SECTION IN NORTHWEST FLOW LYING IN BETWEEN A TROUGH TO OUR
EAST AND A WEAK RIDGE TO THE WEST. SHORTWAVE ENERGY CURRENTLY OVER
THE NORTHWEST CONUS IS FORECAST TO RIDE DOWN THE WEAK RIDGE AND
TOWARD CENTRAL NEBRASKA BY 06Z TONIGHT. AS WEAK SFC LOW PRESSURE
MOVES ACROSS THE NRN PLAINS AHEAD OF THIS UPPER SHORTWAVE...THE
FORECAST AREA WILL BE UNDER WEAK SOUTHERLY SFC FLOW. COMBINED WITH
LOW LEVEL WARM AIR ADVECTION THROUGHOUT THE DAY...TODAY WILL BE
VERY MILD WITH HIGHS APPROACHING UPPER 70S TO NEAR 80. STRONGER
MIXING IS LIKELY ON TUESDAY AHEAD OF AN APPROACHING COOL FRONT IN
ADVANCE OF ABOVE MENTIONED UPPER LEVEL SHORTWAVE. HIGHS SHOULD
APPROACH 80 ONCE AGAIN WITH SLIGHTLY COOLER READINGS IN OUR FAR
NORTHERN COUNTIES BEHIND THE COOL FRONT.
A STRONGER UPPER LEVEL SHORTWAVE TROUGH WILL PUSH ACROSS MONTANA AND
CLOSE OFF AS IT SKIRTS THE NORTH DAKOTA/CANADIAN BORDER MID WEEK.
THIS WILL PUSH A STRONGER COLD FRONT INTO THE FORECAST AREA BY
WEDNESDAY MORNING. INCREASING MOISTURE AND FRONTOGENETICAL FORCING
SHOULD BE ENOUGH TO GENERATE LIGHT PCPN BEHIND THE SURFACE FRONT
THROUGH THE DAY WEDNESDAY. INCREASING PRESSURE GRADIENT BEHIND THE
BOUNDARY WILL CREATE BREEZY IF NOT WINDY CONDITIONS THROUGH THE
DAY WEDNESDAY.
THE UPPER CLOSED LOW WILL CONTINUE TO SINK SOUTHEAST AND DEEPEN AS
IT MOVES INTO THE GREAT LAKES REGION LATE IN THE SCHOOL/WORK WEEK.
DEPENDING ON LOCATION AND TIMING...AREA COULD SEE RAIN SHOWERS SINK
SOUTH INTO THE CWA AROUND THE BACKSIDE OF THE UPPER LOW. ALREADY HAD
POPS GOING FOR THURSDAY SO WILL CONTINUE. ALSO LOOKS AS THOUGH SFC
PRESSURE GRADIENT WILL REMAIN QUITE STRONG WHILE 850MB NORTHWEST
WINDS ARE FORECAST AROUND 45-55KTS. SOME OF THIS WOULD LIKELY MIX
DOWN AND CREATE QUITE BLUSTERY CONDITIONS THROUGH LATE WEEK.
QUIET AND WARMER CONDITIONS ARE EXPECTED INTO THE WEEKEND.
KERN
&&
.AVIATION...
06Z TAFS FOR KOFK...KLNK AND KOMA.
VFR CONDITIONS ARE FORECAST THROUGH MONDAY EVENING. HIGH PRESSURE
WILL MOVE EAST OF EASTERN NEBRASKA MONDAY. LIGHT WINDS AND CLEAR
SKIES OVERNIGHT WILL BECOME SOUTH AND SOUTHWEST NEAR 10KT WITH
SCATTERED TO BROKEN HIGH CLOUDS DURING THE DAY MONDAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
426 AM EDT MON OCT 15 2012
.SYNOPSIS...
COLD FRONT EXITS EAST BY LATE MORNING. MUCH COOLER AIR BEHIND IT THIS
AFTERNOON TO SUNDAY. HIGH PRESSURE TUESDAY INTO WEDNESDAY. NEXT
COLD FRONT THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LIGHT CONVECTION ASSOCIATED WITH PASSING COLD FRONT ACROSS THE
EASTERN THIRD OF THE AREA BY 430 AM...EXPECTED TO EXIT EASTERN
MOUNTAINS BY 7 AM. SFC OBS INDICATED A WIND SHIFT WITH THIS LINE
OF CONVECTION...HOWEVER...DEWPOINTS GRADIENT REMAINS ACROSS
SOUTHEAST OH. AN UPPER LEVEL TROUGH...WITH DESCENT VORTICITY MAX
WILL PASS OVERHEAD THIS AFTERNOON...AND COULD SQUEEZE SOME OF THE
LINGERING MOISTURE INTO ADDITIONAL LIGHT SHOWERS...AND PUSH THE
ACTUAL FRONT EAST OF THE APPALACHIANS AS WELL. THE SFC LOW
PRESSURE OVER THE GREAT LAKES REGION LIFTS NORTHEAST TODAY...BUT
SOME RAP AROUND MOISTURE AND COLDER TEMPS AT H850 WILL STILL UNDER
THE INFLUENCE OF THE AFOREMENTIONED UPPER TROUGH.
SFC HIGH PRESSURE BUILDS BEHIND THE FRONT BUILDS TONIGHT INTO
TUESDAY TO BRING COLDER TEMPERATURES TONIGHT...GENERALLY INTO THE
UPPER 30S EXTREME NORTHWEST...RANGING INTO THE LOWER 40S HIGHER
ELEVATIONS AS THE FREEZING LINE AT H850 APPROACHES FROM THE
NORTHWEST.
WINDS WILL DECREASE SOME TODAY...TURNING WEST NORTHWEST...WITH FEW
WIND GUSTS OVER THE HIGHER TERRAIN THROUGH THE AFTERNOON HOURS.
WENT WITH A BLEND OF MAV AND MET TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
RISING HEIGHTS WITH NW FLOW ALOFT AND SFC HIGH PRESSURE WILL BE
BUILDING INTO THE AREA TUESDAY AS THE UPPER TROUGH CONTINUES TO MOVE
TO THE NORTHEAST. AFTER SOME LINGERING EARLY MORNING CLOUDS AND
PERHAPS A FEW LIGHT SPRINKLES ACROSS THE NORTHEAST HIGH COUNTRY...A
PLEASANTLY COOL DAY UNDER MOSTLY SUNNY SKIES WILL BE IN STORE FOR
THE FORECAST AREA. INHERITED MAX TEMPS IN THE LOW/MID 60S LOWLANDS
AND AROUND 50F FOR THE HIGHEST LOCALES SUCH AS SNOWSHOE LOOK GOOD.
SFC HIGH PRESSURE WILL BEGIN TO SLIDE OFF TO THE EAST OVERNIGHT TUE
NIGHT/EARLY WED. WITH SOME MODEST WARM ADVECTION NOTED AT 850MB AND
SFC WINDS BACKING FROM THE WEST TO THE SOUTH/SOUTHEAST...DID NUDGE
OVERNIGHT LOWS UP GENERALLY BY A COUPLE OF DEGREES.
BY WEDNESDAY ZONAL FLOW ALOFT TRANSITIONS TO SOUTHWESTERLY BY END OF
DAY WITH THE APPROACH OF THE NEXT UPPER LEVEL TROUGH MOVING SE-WARD
ACROSS THE UPPER MIDWEST. A QUICK MOVING S/W TROUGH IN THE MEAN FLOW
WILL SKIRT ACROSS THE SOUTHERN GREAT LAKES AREA TO THE NORTH WED
MORNING...BUT SHOULD ONLY RESULT IN INCREASED MID-LEVEL CLOUDS
MAINLY DURING THE MORNING HOURS. WARMER TEMPS WILL MOVE INTO THE AREA
AS THE SFC HIGH PRESSURE CONTINUES TO MOVE EAST OF AREA. WITH 850MB
TEMPS OF AROUND 10C-11C PROGGED...INHERITED MAX TEMPS IN THE
MID/UPPER 70S LOWLANDS STILL LOOK GOOD WITH A FEW MINOR TWEAKS.
BY THURSDAY THE UPPER LEVEL LOW ACROSS THE MIDWEST ACROSS THE
WESTERN GREAT LAKES WHILE ITS ATTENDANT SFC LOW DEEPENS AND
PINWHEELS AROUND IT PUSHING NORTHWARD ROUGHLY AROUND LAKE SUPERIOR
OR NORTH. CONSIDERABLE DIFFERENCES WITH THE TIMING AND LOCATION OF
UPPER LOW AND SFC FRONT STILL EXIST...WITH THE NAM/EC SLOWER AND GFS
AND OTHERS AMONG THE FASTER SOLUTIONS. THERE APPEARS TO BE DECENT
ENSEMBLE SUPPORT WITH THE SLOWER SOLN/S AND WILL LEAN THE FORECAST
IN THIS DIRECTION...BRINGING POPS INTO THE NW ZONES BY 12Z THU WITH
HIGHER POPS LATER THURSDAY. STILL...WITH THE UNCERTAINTIES WILL CAP
POPS ONLY AT HIGH CHANCE. DID ELECT TO NUDGE MAX TEMPS DOWN SLIGHTLY
WITH 850MB TEMP GUIDANCE DEPICTING THU PM TEMPS OF AROUND 6C-7C.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
OVERALL UNSETTLED WEATHER PATTERN IN THE LONG TERM...WITH MODELS
STARTING TO COME INTO BETTER AGREEMENT THAN IN PREVIOUS RUNS. PERIOD
STARTS OUT WITH AN UPPER TROUGH DEEPENING OVER THE MIDWEST...AND
EVENTUALLY SWINGING A COLD FRONT THROUGH THE AREA EITHER THURSDAY OR
FRIDAY. THIS WILL BRING AN INCREASE IN SHOWER...AND ISOLD
THUNDERSTORM ACTIVITY...AS WELL AS WARMING TEMPERATURES OUT AHEAD OF
THE FRONT. AFTER FRONT EXITS TO THE EAST...UPPER LEVEL LOW WILL
DEEPEN ACROSS THE U.S...AND AFFECT THE AREA OVER THE NEXT SEVERAL
DAYS. ECMWF IS STARTING TO COME INTO LINE A BIT BETTER WITH THE
GFS...WITH LOW DEEPENING ACROSS THE UPPER MIDWEST...KEEPING THE AREA
IN A WARM SOUTHWESTERLY FLOW...UNTIL IT FINALLY KICKS OFF TO THE
EAST LATE IN THE WEEK. ECMWF IS STILL A LITTLE DEEPER WITH THIS
TROUGH ACROSS THE U.S. THAN THE GFS...BUT OVERALL...MODELS STARTING
TO COME INTO AGREEMENT.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
CONVECTION ASSOCIATED WITH COLD FRONT EVIDENT ON RADAR IMAGES AND
SFC OBS ACROSS HTS...NORTH NORTHEAST TO JUST WEST OF PKB BY
06Z...WILL PRODUCE BRIEF PERIODS OF IFR VISIBILITIES UNDER
MODERATE TO HEAVY RAIN. BRIEF PERIODS OF STRONG GUSTY WINGS ARE
POSSIBLE JUST AHEAD OF THE FRONT REACHING 25-30 KNOTS AS WELL.
THE FRONT WILL ADVANCE QUICKLY EAST TO REACH CRW BY
0630-07Z...AND THE REST OF EASTERN SITES BY 09-10Z. EXPECT
STRONGER WINDS AT HIGHER ELEVATIONS OVERNIGHT AS THE COLD FRONT
PASSES THROUGH. VFR CONDITIONS WILL PREVAIL...EXCEPT IFR ALONG
STRONG SHOWERS...BUT WILL LAST LEST THAN 40 MINUTES. MVFR
CEILINGS WILL FOLLOW BEHIND THE FRONT ABOUT 2500 FEET.
FRONT EXITS THE MOUNTAINS AROUND 12Z. BEHIND THE FRONT...SCATTERED
SHOWERS WILL CONTINUE THRU THE DAY MAINLY NORTHERN SITES. MVFR
CEILINGS...LINGERING INTO MONDAY.
HIGH PRESSURE BUILDS OVERHEAD TAKING CONTROL EARLY TUESDAY AND
WEDNESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF STRONG WIND ALOFT AND MIXING DOWN TO
SFC WITH CONVECTION COULD VARY. TIMING ON TRANSITIONS TO/FROM MVFR
COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 10/15/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY M M M H H H M M M M M M
HTS CONSISTENCY M M M M M M M M M M H H
BKW CONSISTENCY H H H H H H M M M M M M
EKN CONSISTENCY H H H H H H M M H H M M
PKB CONSISTENCY M H H H H H H H M M H H
CKB CONSISTENCY H H M H H H M M H M M M
AFTER 06Z TUESDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...SL
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1147 PM CDT SUN OCT 14 2012
.DISCUSSION...
SEE 06Z TAF DISCUSSION...
&&
.AVIATION...
COLD FRONT VERY SLOWLY CREEPING IN TO HOUSTON METRO AREA.
ADDED PRE-FRONTAL VCSH TO TERMINALS FROM IAH EASTWARD. ISOLATED
LIGHT RAIN SHOWERS ARE POPPING UP AS THE FRONT APPROACHES THE
COAST. EXPECT LOW CIGS CLEARING AT IAH BY 08Z...HOU BY 09Z...AND
GLS BY 13Z.
BEHIND THE FRONT...CLEAR SKIES...UNLIMITED VISIBILITY...AND NORTH
WINDS BETWEEN 5-10 KNOTS SHOULD PREVAIL. 44
&&
.PREV DISCUSSION... /ISSUED 942 PM CDT SUN OCT 14 2012/
DISCUSSION...
AT 9 PM THE COLD FRONT HAD MOVE THROUGH CROCKETT...MADISONVILLE...
COLLEGE STATION. SHOWER AND THUNDERSTORM ACTIVITY HAD DIMINISHED
OVER THE PAST COUPLE OF HOURS...HOWEVER BETWEEN 9 AND 930 PM
ISOLATED SHOWERS WERE BEGINNING TO DEVELOP ALONG A PREFRONTAL
TROUGH IN THE METRO HOUSTON AREA.
A LOOK AT THE 00Z UPPER AIR ANALYSES SHOWS THAT THE BEST 700 MB
MOISTURE WAS JUST TO THE EAST AND WEST OF THE FORECAST AREA.
HOWEVER...850 MB DEWPOINTS WERE BETWEEN 12 AND 14 CELCIUS. THE
LATEST RAP MODEL ALSO SHOWS THE BEST LOW-LEVEL CONVERGENCE OVER
THE SE TX COASTAL AREAS.
WITH THIS IN MIND...WILL ADJUST THE POPS SLIGHTLY DOWNWARD FOR THE
REMAINDER OF THIS EVENING...MAINLY TO ACCOUNT FOR THE LOCATION OF
THE FRONT AND THE CURRENT LACK OF SHOWER ACTIVITY. DO THINK THAT
BETTER COVERAGE WILL OCCUR AS THE FRONT MOVES INTO THE BETTER
MOISTURE ALONG THE COAST...AND WILL KEEP THE OVERNIGHT POPS IN
PLACE.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 59 84 59 81 64 / 10 10 0 10 10
HOUSTON (IAH) 65 86 59 83 64 / 30 10 0 10 10
GALVESTON (GLS) 73 83 70 82 73 / 30 10 0 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...40
AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1052 PM PDT Sun Oct 14 2012
.SYNOPSIS...Rain is expected to spread over the remainder of the
Inland Northwest tonight, as a cold front moves through the region.
A strong storm will arrive early Tuesday morning, bringing widespread
rain and windy conditions. Wind gusts of 35 to 45 mph will be
likely on Tuesday afternoon over portions of the Inland Northwest.
A drier, more stable pattern is expected for Wednesday and
Thursday, before more precipitation chances enter late in the week
with cooler temperatures.
&&
.DISCUSSION...
The cold front is beginning to make its way east of the Cascades.
Latest radar imagery at around 8:30 PM PDT this evening is
starting to show some enhanced echos developing over the Moses
Lake Area and Upper Columbia Basin. The leading edge of the front is
slightly further to the northwest, stretching from around Oroville
to Lincoln City in northeast Oregon. Out ahead of the front,
further east over the basin and into the ID Panhandle, very light
rain has been falling due to some weak isentropic accent. These
showers have generally yielded a few hundredths of an inch of
rainfall, except in the mountains where orographic have produced
slightly higher amounts up to around a tenth or more in the last
five hours or so. Expect rainfall to pick up in intensity a bit as
the cold front produces stronger lift as it moves east across the
region tonight.
Increased precipitation chances a bit and rainfall amounts,
especially in the basin where around a tenth of an inch from the
frontal band is expected. The HRRR model seems to have a better
handle on this frontal band with it moving through the Palouse,
Spokane Area and Northeast Mountains between 10:00 PM and 2:00 AM
tonight. Some lingering showers will pop up behind the front as low
to mid levels of the atmosphere become slightly more unstable with
the upper level shortwave moving through. However, the upper level
wave is fairly weak and the atmosphere will dry out from the top
down; so, I don`t expect a lot of shower activity once the front
pushes east and rain may just transition to a little drizzle
instead. Showers will continue to be more likely in the Panhandle
mountains due to terrain effects. Rainfall amounts will be highest
in the ID Panhandle where a quarter of an inch of rain or more is
expected between midnight tonight and tomorrow morning. These
amounts shouldn`t be much of a concern and probably will be well
received due to our extended stretch dry weather since late July
through early October. /SVH
&&
.AVIATION...
06Z TAFS: Light to moderate rainfall will continue to fill in over
the region southeast of a line from Wenatchee to Republic as a cold
front moves southeast across the region. Expect cigs to lower into
MVFR/IFR category with rain transitioning over to some light drizzle
with low stratus through the morning hours over extreme eastern WA.
Showers will continue in the ID Panhandle through tomorrow
afternoon. A stronger and wetter storm system will begin to move in
early Monday evening. This storm will feature a very moist air mass
ahead of a strong cold front. This will bring moderate to heavy rain
with reduced visibilities likely under heavier rain bands. Strong
westerly winds will likely mix down to the surface with cold front
passage Sunday night as well. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 53 64 50 57 36 55 / 100 40 100 50 10 0
Coeur d`Alene 52 61 49 54 34 53 / 100 90 100 70 10 10
Pullman 51 66 50 55 34 54 / 100 70 90 80 10 0
Lewiston 55 72 56 60 40 59 / 70 60 80 60 10 0
Colville 50 63 49 57 29 56 / 90 40 100 30 10 10
Sandpoint 50 58 50 52 32 51 / 100 100 100 70 10 10
Kellogg 49 58 50 50 33 49 / 100 100 100 100 20 10
Moses Lake 52 71 51 64 36 59 / 70 30 30 10 0 0
Wenatchee 52 68 51 61 38 58 / 40 20 50 10 0 0
Omak 47 66 47 60 34 59 / 50 20 60 10 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
227 AM CDT MON OCT 15 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
227 AM CDT MON OCT 15 2012
MAIN FORECAST CONCERN IS THE IMPACTS ON THE AREA FROM A DEEP UPPER
TROUGH DROPPING INTO THE NORTHERN PLAINS TUESDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED NEARLY ZONAL FLOW ACROSS THE NORTHERN ROCKIES AND
SOUTHWEST CANADA...AND TROUGHING ACROSS THE WESTERN GREAT LAKES
REGION INTO ILLINOIS. THE FORECAST AREA LIES ON THE WESTERN SIDE
OF THIS TROUGHING...FAVORING SUBSIDENCE AND DRY AIR. 00Z SOUNDINGS
FROM ABR AND MPX REFLECT THESE ATTRIBUTES...WITH PRECIPITABLE
WATER VALUES NEAR 0.5 INCH. SATELLITE IMAGERY ALSO REFLECTS THE
DRY AIR WITH CLEARING ACROSS MUCH OF MINNESOTA AND IOWA. SOME
COOLER AIR TOO FLOWING IN ON THE BACK SIDE OF THE TROUGH WITH
850MB TEMPS OF 3C AT MPX AT 00Z. HOWEVER...WARMER READINGS OF
7-15C AT 850MB WERE OBSERVED IN THE DAKOTAS. AT THE SURFACE...A
RIDGE OF HIGH PRESSURE WAS PRESENT ACROSS WESTERN MINNESOTA WHILE
A NEW LOW PRESSURE SYSTEM WAS TAKING SHAPE ACROSS SOUTHERN
SASKATCHEWAN.
TODAY AND TONIGHT...FOCUS IS ON A COLLECTION OF SHORTWAVES IN THE
ZONAL FLOW OVER WASHINGTON. MODELS ARE IN GOOD AGREEMENT SENDING
THESE EAST INTO THE EASTERN DAKOTAS AND WESTERN MINNESOTA BY 12Z
TUESDAY. THERE EVEN APPEARS TO BE A WEAK TROUGH SIGNATURE IN THE
500MB HEIGHT FIELD AT 12Z WITH THESE SHORTWAVES. AS THESE SHORTWAVES
HEAD EAST...THEY WILL HELP PICK UP THE CURRENT SYSTEM IN SOUTH
CENTRAL SASKATCHEWAN...SENDING A TROUGH INTO MINNESOTA BY 12Z
TUESDAY. WARM ADVECTION AHEAD OF THIS SYSTEM WILL COMMENCE OVER THE
FORECAST AREA THIS AFTERNOON...WITH 850MB TEMPS TOPPING OUT BETWEEN
4-8C BY 00Z...WARMEST WEST. OTHER THAN SOME INCREASE IN WARM
ADVECTION HIGH AND PERHAPS MID CLOUDS AS WELL LATE IN THE DAY...
CURRENTLY OBSERVED CROSSING THE DAKOTAS...SHOULD SEE PLENTY OF SUN.
AS A RESULT...ANTICIPATING TEMPERATURES TO TOP OUT IN THE MID 50S TO
MID 60S. FOR TONIGHT...PLANNING ON THE MID AND HIGH CLOUDS TO
QUICKLY ENCOMPASS THE AREA...HELPING TO LIMIT TEMPERATURE FALL. IN
ADDITION...MODELS SHOW AN INCREASE OF 850MB MOISTURE TRANSPORT
THROUGH THE NIGHT AHEAD OF THE TROUGH COMING INTO MINNESOTA. NOSE OF
THIS MOISTURE TRANSPORT...AS WELL AS THE BULK OF ISENTROPIC LIFT...
APPEARS TO BE SITUATED MAINLY NORTH OF THE AREA. AS SUCH...EXPECTING
MOST PRECIPITATION TO STAY NORTH. HOWEVER...DID INTRODUCE A 20
PERCENT CHANCE IN TAYLOR COUNTY SINCE THEY LOOK TO BE RIGHT ON THE
EDGE OF WHERE THE WARM ADVECTION PRECIPITATION MAY EXIST. FOLLOWED A
BLEND OF GUIDANCE FOR LOWS.
TUESDAY...THE WEAK UPPER TROUGH SIGNATURE PRESENT OVER THE
EASTERN DAKOTAS AT 12Z TUESDAY IS FORECAST BY ALL MODELS TO CROSS
THE AREA ON TUESDAY. THE SAME QUESTIONS REMAIN IF THIS TROUGH CAN
PRODUCE PRECIPITATION AS IT MOVES THROUGH. THE 14.12Z ECMWF WAS MUCH
MORE IMPRESSIVE WITH QPF COMPARED TO ITS PREVIOUS RUN WITH MUCH OF
THE AREA AFFECTED. MEANWHILE THE 15.00Z NAM CONTINUES TO PAINT A
MOSTLY DRY SCENARIO OUTSIDE OF SOME LINGERING WARM ADVECTION PRECIP
OVER TAYLOR COUNTY IN THE MORNING. THE 15.00Z GFS LIES IN-BETWEEN
THE TWO SCENARIOS WITH QPF MAINLY IN THE MORNING ALONG AND NORTHEAST
OF I-94. THINKING THE ECMWF IS OVERDONE WITH THE AMOUNT OF QPF GIVEN
THE OVERALL LACK OF MOISTURE AVAILABILITY...ESPECIALLY IN THE LOWER
LEVELS. THEREFORE...HAVE STAYED CLOSE TO THE PREVIOUS FORECAST OF
20-30 PERCENT CHANCES ALONG AND NORTHEAST OF I-94. NEW 15.00Z ECMWF
HAS A LITTLE LESS QPF...AND FOCUSES ITS MAIN AREA SIMILAR TO WHERE
THE FORECAST HAS IT. TEMPERATURES ARE A BIT TRICKY ON TUESDAY AS
MUCH OF THE MORNING WILL LIKELY BE CLOUDY WITH MID AND HIGH CLOUDS
AROUND. AS THE TROUGH COMES THROUGH...THE OPPORTUNITY FOR CLEARING
EXISTS. 850MB TEMPS REALLY DO NOT COOL WITH THE TROUGH...HOVERING
BETWEEN 9C NORTH AND 13C SOUTH. HERE TOO WILL STAY PRETTY CLOSE TO
THE PREVIOUS FORECAST WITH HIGHS FROM THE MID 60S EAST (MOST CLOUDS)
TO LOW 70S WEST.
TUESDAY NIGHT...A VERY POTENT UPPER TROUGH IS PROGGED TO DIG DOWN
INTO MONTANA AND THE NORTHERN PLAINS BY 12Z WEDNESDAY. AS THIS
TROUGH DIGS IN...A COLD FRONT GETS SENT EASTWARD...PERHAPS REACHING
WESTERN PORTIONS OF THE FORECAST AREA BY 12Z WEDNESDAY. THE 15.00Z
GFS AND NAM...AS WELL AS THE 14.12Z/15.00Z ECMWF KEEP PRECIPITATION
NORTHWEST OF THE AREA THROUGH TUESDAY NIGHT. THIS SEEMS REASONABLE
GIVEN THAT THE BULK OF THE PRECIPITATION LOOKS TO OCCUR POST-FRONTAL
AND MORE ASSOCIATED WITH DPVA FROM THE POTENT TROUGH. AS SUCH...HAVE
REMOVED ANY LOW CHANCES OF PRECIPITATION IN FAR WESTERN PORTIONS OF
THE AREA. TEMPERATURES COULD DROP QUICKLY IN THE EVENING...
ESPECIALLY AT THE TYPICAL COLD SPOTS...WITH MOSTLY CLEAR SKIES AND A
BAGGY PRESSURE GRADIENT IN PLACE. INCREASING MID AND HIGH CLOUDS AS
WELL AS WINDS AHEAD OF THE FRONT AND UPPER TROUGH SHOULD HELP TO
HOLD TEMPERATURES STEADY OR EVEN RISE AFTER MIDNIGHT.
WEDNESDAY AND WEDNESDAY NIGHT...MODELS ARE IN REALLY GOOD AGREEMENT
THAT THE POTENT UPPER TROUGH WILL CONTINUE TO DIG SOUTHEASTWARD...
FULLY ENCOMPASSING THE AREA BY WEDNESDAY NIGHT. HOWEVER...THERE ARE
SOME IMPORTANT DETAILS WITHIN THE UPPER TROUGH THAT MODELS DIFFER
ON. THE FIRST IS WITH A SHORTWAVE EXTENDING SOUTH OF AN UPPER LOW
CONTAINED WITHIN THE TROUGH. THIS SHORTWAVE...PROGGED NEAR BISMARCK
NORTH DAKOTA AT 12Z WEDNESDAY...THE 15.00Z GFS IS MUCH FASTER THAN
ANY OTHER MODEL WITH IT BY BRINGING IT INTO THE FORECAST AREA BY
00Z. THE 15.00Z NAM/UKMET/CANADIAN/ECMWF ARE ALL SLOWER...ONLY
REACHING WESTERN MINNESOTA BY 00Z. THIS IS A SIGNIFICANT ISSUE AS
THE FASTER GFS WOULD NOT ALLOW AS MUCH MOISTURE RETURN FROM THE GULF
OF MEXICO TO COME UP INTO THE FORECAST AREA. THUS...THE GFS ENDS UP
AS A DRY SOLUTION. ALL THE OTHER MODELS PRODUCE PRECIPITATION ON
WEDNESDAY WHICH SEEMS REASONABLE. THUS...THE 60 PERCENT CHANCES ARE
STILL ON TRACK. WEDNESDAY NIGHT IS A LITTLE MORE UP IN THE AIR...
THOUGH. THINGS IN PLAY WITH PRECIPITATION CHANCES INCLUDE: TRACK OF
THE UPPER LOW WITHIN THE TROUGH...A POSSIBLE DRY SLOT...AND A TROWAL
AND COLD CONVEYOR BELT AREA WRAPPING AROUND THE UPPER LOW. THE
PMDHMD FROM HPC DISCUSSES THIS SITUATION WELL...WITH MODELS ALL OVER
THE PLACE WITH THESE FEATURES AND ALL PLAUSIBLE. THEREFORE...PLAN ON
TAKING A CONSENSUS APPROACH. AS THE PMDHMD STATES TOO...THE SYSTEM
RESPONSIBLE FOR THE POTENT UPPER TROUGH IS IN A DATA SPARSE REGION
OF THE NORTHERN/NORTHEAST PACIFIC. SO IT MAY TAKE AWHILE BEFORE
MODELS SETTLE DOWN ON A SOLUTION WITH THE VARIOUS FEATURES. THE
CONSENSUS APPROACH RESULTS IN 30 TO 50 PERCENT CHANCES...HIGHEST
ACROSS THE NORTH. ALSO FOLLOWED THE CONSENSUS APPROACH FOR
TEMPERATURES. SHOULD STILL BE NEAR NORMAL ON WEDNESDAY WITH THE WARM
ADVECTION AHEAD OF A SURFACE COLD FRONTAL PASSAGE. HOWEVER...
TEMPERATURES LOOK TO FALL IN THE AFTERNOON AS THE FRONT PASSES AND
RAIN DEVELOPS. IF A DEEP DRY SLOT ENTERS THE PICTURE WEDNESDAY
NIGHT...LOWS COULD BOTTOM OUT IN 30S. HOWEVER...WILL PLAY MORE
CLOUDS AND WIND TO KEEP LOWS IN THE 40S.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
227 AM CDT MON OCT 15 2012
15.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN FAIRLY GOOD
AGREEMENT ON HANDLING THE UPPER TROUGH AND ITS LIFT OUT NORTHEAST
AWAY FROM THE AREA. THE GFS AGAIN IS SLIGHTLY FAST...BUT ALL MODELS
AGREE THAT BY FRIDAY NIGHT...THE UPPER TROUGH WILL BE FAR ENOUGH
EAST OF THE AREA TO ALLOW CONDITIONS TO DRY OUT. UNTIL THEN...SAME
CONCERNS THAT WERE PRESENT ON WEDNESDAY NIGHT WITH POSITIONS OF THE
UPPER LOW IN THE TROUGH...DRY SLOT...TROWAL AND COLD CONVEYOR BELT
STILL PERSIST THROUGH FRIDAY. AS A RESULT...HAVE CONTINUED TO FOLLOW
A CONSENSUS APPROACH. HIGHEST CHANCES OF PRECIPITATION EXPECTED ON
THURSDAY SINCE THERE ARE INDICATIONS THAT THE TROUGH WILL FILL AFTER
THEN. COOL CONDITIONS ARE LIKELY TOO WITH THE UPPER TROUGH IN PLACE.
850MB TEMPS ARE ONLY PROGGED IN THE 0-2C RANGE. COMBINE THIS WITH
PRECIPITATION COULD END UP KEEPING HIGHS IN SOME LOCATIONS FROM EVEN
REACHING 50...ESPECIALLY ON THURSDAY.
FOR THE WEEKEND...MODELS ARE INDICATING THAT A POTENT UPPER TROUGH
WILL DROP SOUTH OUT OF THE GULF OF ALASKA AND AT LEAST INTO BRITISH
COLUMBIA. THE 14.12Z AND 15.00Z ECMWF RUNS AS WELL AS SOME OF THE
GFS ENSEMBLES TAKE IT ONE STEP FURTHER AND DIG THE TROUGH INTO THE
PACIFIC NORTHWEST. ALL SOLUTIONS THUS WOULD YIELD AT LEAST ZONAL
FLOW DOWNSTREAM INTO THE FORECAST AREA...RESULTING IN WARMING AND
DRY CONDITIONS. IN THE CASE OF THE ECMWF...RIDGING ENDS UP BUILDING
INTO THE FORECAST AREA. FOR NOW HAVE FOLLOWED THE CONSENSUS APPROACH
FOR TEMPERATURES GIVEN THE SPREAD IN HOW THE UPPER FLOW EVOLVES...
BUT SHOULD THE ECMWF VERIFY...TEMPERATURES MAY NEED TO BE INCREASED.
BY 18Z SUNDAY...THE ECMWF SUGGESTS 850MB TEMPS OF 10-14C...COMPARED
TO 4-8C FROM THE GFS.
&&
.AVIATION...THROUGH 06Z TUESDAY
1139 PM CDT SUN OCT 14 2012
CLEAR SKIES AND RECENT RAINS HAVE ALLOWED SOME FOG TO FORM AT KLSE
BUT IT IS HAVING PROBLEMS SUSTAINING ITSELF DUE TO SOME STRONGER
WINDS JUST ABOVE THE RIDGE TOP LEVEL AND DRIER AIR THAT IS SLOWLY
ADVECTING IN FROM THE NORTH. THE FOG WILL ALSO BE INHIBITED FOR A
WHILE AS A DECK OF MID LEVEL CLOUDS MOVES ACROSS THE REGION.
EXPECTING THESE TO CLEAR OUT SOON ENOUGH TO POSSIBLY ALLOW THE FOG
TO REFORM AGAIN LATE TONIGHT WHEN THE 15.00Z NAM SOUNDING SUGGEST
SATURATION AT THE SURFACE COULD OCCUR. THIS FOG SHOULD THEN
DISSIPATE SHORTLY AFTER SUNRISE LEAVING CLEAR SKIES AND VFR
CONDITIONS FOR MUCH OF MONDAY AT BOTH TAF SITES. THE NEXT SHORT
WAVE TROUGH WILL QUICKLY BE APPROACHING FROM THE NORTHWEST AND
SHOULD START TO SPREAD IN A DECK OF MID LEVEL CLOUDS DURING THE
LATE AFTERNOON. UPSTREAM OBSERVATIONS ACROSS NORTH DAKOTA AND
MONTANA INDICATE THESE CLOUDS SHOULD BE AROUND 10K FEET WITH SKIES
QUICKLY GOING FROM CLEAR TO BROKEN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CDT MON OCT 15 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1139 PM CDT SUN OCT 14 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
307 PM CDT SUN OCT 14 2012
BIGGEST FORECAST CHALLENGES ARE ON THE TIMING OF THE ENDING OF THE
PRECIPITATION TONIGHT ALONG WITH CLOUD TRENDS. ALSO RAIN CHANCES ON
WEDNESDAY.
18Z SURFACE ANALYSIS SHOWS AN AREA OF LOW PRESSURE OVER NORTHERN
ILLINOIS...WITH RADAR SHOWING A DEFORMATION BAND OF RAIN OVER
SOUTHERN AND CENTRAL WISCONSIN AND NORTHERN ILLINOIS. THE BACK EDGE
HAS STEADILY BEEN MOVING EASTWARD AND NOW EXTENDS FROM AROUND
NEILLSVILLE WISCONSIN...TO MONONA IOWA. VISIBLE SATELLITE IMAGERY
SHOWING BACK EDGE OF CLOUDS PUSHING INTO EASTERN MINNESOTA...WITH A
BATCH OF MID LEVEL CLOUDS OVER NORTHERN MINNESOTA.
14.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. IN THE
NEAR TERM...SURFACE LOW WILL CONTINUE TO PULL NORTHEAST INTO LOWER
MICHIGAN THIS EVENING. DEFORMATION AREA OF RAIN WILL CONTINUE TO
SHIFT EASTWARD. THE 14.12Z RAP AND 14.12Z GFS PUSH THE PRECIPITATION
TO THE EAST OF THE AREA BY 00Z...WHILE THE NAM IS A LITTLE SLOWER.
BASED ON MOVEMENT OF THE BACK EDGE...BELIEVE IT WILL CLEAR THE
FORECAST AREA BY 00Z. QUESTION THEN BECOMES HOW QUICKLY THE SKIES
CLEAR. BOTH THE NAM AND GFS RELATIVE HUMIDITY PROGS SHOW THE LOWER
STRATUS TO ADVECT EASTWARD THIS EVENING...BUT SOME MID LEVEL MOISTURE
AROUND 700MB ROTATES SOUTHWARD FROM NORTHERN MINNESOTA INTO THE
AREA. VISIBLE SATELLITE IMAGERY SHOWS THIS MOISTURE NOW OVER NORTHERN
MINNESOTA. THUS DID ADD DOME MORE CLOUDS TO THE EVENING HOURS BEFORE
CLEARING AFTER MIDNIGHT. BETWEEN THE CLOUDS AND THE PRESSURE
GRADIENT REMAINING TIGHT DO NOT EXPECT ANY FOG FORMATION DESPITE THE WET
GROUND FROM THE RAIN.
SURFACE HIGH PRESSURE BUILDS IN MONDAY...WITH THE RIDGE AXIS
QUICKLY MOVING EAST MONDAY NIGHT. 850MB TEMPERATURES IN THE 5 TO 7
DEGREE RANGE CELSIUS AND PLENTY OF SUN WILL MAKE FOR TEMPERATURES
NEAR THE SEASONAL NORMALS. WARM ADVECTION SPREADS ACROSS THE AREA ON
THE BACK SIDE OF THE HIGH MONDAY NIGHT AS A A WEAK SHORTWAVE DROPS
ACROSS THE PLAINS. FORCING SIGNALS RATHER WEAK AND FEEL BEST CHANCES
FOR PRECIPITATION WILL BE ACROSS THE FAR NORTH.
WARM ADVECTION CONTINUES IN EARNEST ON TUESDAY AS 850MB TEMPERATURES
RISE INTO THE LOWER TEENS CELSIUS. WITH A SOUTHWESTER LOW LEVEL
FLOW...EXPECT TEMPERATURES TO TOP OFF IN THE 60S TO LOWER 70S. A
SHORTWAVE WILL TRANSLATE ALONG THE CANADIAN BORDER WITH SOME WEAK
FORCING ACROSS NORTHERN WISCONSIN. GFS AND ECMWF DO GENERATE SOME
LIGHT QPF ACROSS THE FAR NORTHERN COUNTIES...WHILE NAM IS RELATIVELY
DRY. DID KEEP THE LOWER END PROBABILITIES FOR THIS TIME FRAME.
ON WEDNESDAY...A 130 KNOT 300MB JET DIGS DOWN ACROSS THE ROCKIES
INTO THE PLAINS. IN RESPONSE A STRENGTHENING 500MB CLOSED LOW WILL
DROP SOUTHWARD TO NEAR LAKE WINNIPEG. THIS AMPLIFIED FLOW WILL PUSH
A COLD FRONT ACROSS THE AREA...WITH RATHER IMPRESSIVE COLD ADVECTION
IN ITS WAKE. STRONG DYNAMIC FORCING WITH FGEN SIGNAL PUSHES ACROSS
THE AREA. MODELS CONSISTENT WITH PUSHING A BAND OF PRECIPITATION
ACROSS THE AREA WEDNESDAY. SOME WEAK INSTABILITIES LOOK TO BE
PRESENT ACROSS IOWA AND SOUTHWEST WISCONSIN. DID RAISE PROBABILITIES
IN THIS TIME FRAME AND KEPT THE MENTION OF THUNDER ACROSS THE SOUTH.
THESE PRECIPITATION CHANCES WILL REMAIN WEDNESDAY NIGHT AS 500MB
CLOSED LOW SLOWLY CONTINUES TO SINK SOUTHWARD INTO THE AREA.
.LONG TERM...THURSDAY THROUGH SUNDAY
307 PM CDT SUN OCT 14 2012
THE AFOREMENTIONED 500MB LOW WILL BE THE MAIN WEATHER FEATURE OF
INTEREST AT LEAST THROUGH THE EARLY PORTIONS OF THE WEEKEND. ONCE
AGAIN THE 14.12Z GFS IS FASTER AT OPENING THE WAVE UP AND PUSHING IT
EASTWARD ON SATURDAY...WHILE THE ECMWF MAINTAINS ITS CONTINUITY IN
SLOWLY LIFTING IT NORTHEAST LATER IN THE WEEKEND. GIVEN STRENGTH OF
SYSTEM THE SLOWER SOLUTIONS LOOKS MORE REASONABLE AT THIS POINT. WILL
CONTINUE TO SEE RAIN CHANCES THROUGH THE ENTIRE PERIOD. TEMPERATURES
LOOK TO BE BELOW NORMAL...WITH SLOW WARMING TREND BY SUNDAY AS THE
LOW PUSHES AWAY. WILL HAVE TO WAIT FOR LATER MODEL RUNS TO PIN DOWN
ANY OF THE DETAILS.
&&
.AVIATION...THROUGH 06Z TUESDAY
1139 PM CDT SUN OCT 14 2012
CLEAR SKIES AND RECENT RAINS HAVE ALLOWED SOME FOG TO FORM AT KLSE
BUT IT IS HAVING PROBLEMS SUSTAINING ITSELF DUE TO SOME STRONGER
WINDS JUST ABOVE THE RIDGE TOP LEVEL AND DRIER AIR THAT IS SLOWLY
ADVECTING IN FROM THE NORTH. THE FOG WILL ALSO BE INHIBITED FOR A
WHILE AS A DECK OF MID LEVEL CLOUDS MOVES ACROSS THE REGION.
EXPECTING THESE TO CLEAR OUT SOON ENOUGH TO POSSIBLY ALLOW THE FOG
TO REFORM AGAIN LATE TONIGHT WHEN THE 15.00Z NAM SOUNDING SUGGEST
SATURATION AT THE SURFACE COULD OCCUR. THIS FOG SHOULD THEN
DISSIPATE SHORTLY AFTER SUNRISE LEAVING CLEAR SKIES AND VFR
CONDITIONS FOR MUCH OF MONDAY AT BOTH TAF SITES. THE NEXT SHORT
WAVE TROUGH WILL QUICKLY BE APPROACHING FROM THE NORTHWEST AND
SHOULD START TO SPREAD IN A DECK OF MID LEVEL CLOUDS DURING THE
LATE AFTERNOON. UPSTREAM OBSERVATIONS ACROSS NORTH DAKOTA AND
MONTANA INDICATE THESE CLOUDS SHOULD BE AROUND 10K FEET WITH SKIES
QUICKLY GOING FROM CLEAR TO BROKEN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
307 PM CDT SUN OCT 14 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...04
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1101 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION THIS
AFTERNOON...AND THEN PASS TONIGHT. GUSTY WINDS WILL USHER IN A
COOLER AIRMASS FOR TUESDAY. HIGH PRESSURE WILL BUILD INTO THE
REGION TUESDAY NIGHT THROUGH THURSDAY...BEFORE MOVING EAST OF THE
AREA THURSDAY NIGHT. A STORM SYSTEM MAY IMPACT THE AREA NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT WAS LOCATED OVER CENTRAL PENNSYLVANIA WITH SHOWERS
BREAKING OUT ACROSS THE MID ATLANTIC AND SE PA. RAIN WILL BEGIN TO
OVERSPREAD THE AREA BY EARLY THIS AFTERNOON AND IS IN LINE WITH
THE CURRENT FORECAST PRODUCT SUITE. JUST NEEDED TO MAKE A FEW
ADJUSTMENTS TO ACCOUNT FOR CURRENT CONDITIONS. THERE HAVE ALSO BEEN
A FEW BREAKS IN THE CLOUD DECK WITH SKIES BECOMING PARTLY SUNNY.
THIS WILL BE SHORT LIVED AS THE THE RAIN SHIELD EXPANDS TO THE NE
IN RESPONSE TO A DIGGING UPPER TROF OVER THE OH AND TN VALLEYS.
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN
THE DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV/LAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW
AND THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
A COLD FRONT THAT EXTENDS FROM CENTRAL NY STATE TO CENTRAL PA AS
OF 15Z WILL REACH THE NY METRO AROUND SUNSET AS IT PROGRESSES EAST
AT JUST UNDER 20 KT. HIGH PRESSURE BUILDS IN FOR TUESDAY.
MOIST S/SW FLOW AHEAD OF THE FRONT WILL ALLOW SHOWER ACTIVITY
AHEAD OF THE FRONT TO QUICKLY EXPAND NE ACROSS THE NY METRO
REGION. THERE IS UNCERTAINTY HOW FAST LOWER CIGS WILL FORM AND HOW
LOW THEY`LL GO - BUT MODERATELY CONFIDENT OF NOTHING LOWER THAN MARGINAL
VFR CIGS...THOUGH THEY COULD BE IN THE THE 1000-2000 RANGE BY LATE
AFTN.
AN ISO TSTM IS ALSO POSSIBLE DURING TEMPO PERIODS WITH OCCASIONAL HEAVY
PCPN.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. CIGS OF
1000-1500 POSSIBLE WITH BRIEF 2SM VSBY IN TEMPO PERIOD TIMES.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. OCCASIONAL
GUSTS TO 20 KT POSSIBLE INTO THE LATE AFTN. CIGS OF 1000-2000
POSSIBLE WITH BRIEF 2SM VSBY IN TEMPO PERIOD TIMES.
KLGA FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. OCCASIONAL
GUSTS TO 20 KT POSSIBLE INTO THE LATE AFTN. CIGS OF 1500-2000
POSSIBLE WITH BRIEF 2SM VSBY IN TEMPO PERIOD TIMES.
KTEB FCSTER COMMENTS: HIGH CONFIDENCE IN WND FCST. CIGS OF
1000-1500 POSSIBLE WITH BRIEF 2SM VSBY IN TEMPO PERIOD TIMES.
KHPN FCSTER COMMENTS: BRIEF IFR POSSIBLE IN HEAVY PCPN DURING TEMPO
PERIOD TIMES.
KISP FCSTER COMMENTS: BRIEF IFR POSSIBLE IN HEAVY PCPN DURING TEMPO
PERIOD TIMES.
OUTLOOK FOR 15Z TUE THROUGH FRIDAY...
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC/DW
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC/TONGUE
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS NEW YORK NY
732 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION TODAY...AND
PASS TONIGHT. GUSTY WINDS WILL USHER IN A COOLER AIRMASS FOR
TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT
THROUGH THURSDAY...BEFORE MOVING EAST OF THE AREA THURSDAY NIGHT.
A STORM SYSTEM MAY IMPACT THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS LOCATED IN WESTERN PENNSYLVANIA THIS MORNING. THE
CWA WILL REMAIN IN THE WARM SECTOR BEFORE THE FRONT ARRIVES.
CLOUDS HAVE OVERSPREAD MUCH OF THE CWA...HOWEVER IT WILL TAKE
SLIGHTLY LONGER FOR PRECIPITATION TO MOVE IN.
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN
THE DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV/LAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW
AND THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES FROM THE WEST TODAY BEFORE PASSING THROUGH
LATE IN THE DAY INTO THIS EVENING.
S/SW WINDS AVERAGING MOSTLY 10-15 KT WITH GUSTS AROUND 20 KT BECOME
SLIGHTLY LIGHTER THIS AFTERNOON AND LESS GUSTY. WIND SHIFT TO NW
ARRIVES CLOSE TO MIDNIGHT.
CHC CIGS PREVAIL 1500-3000 FT INSTEAD OF TEMPO. ISO TSTM IS ALSO
POSSIBLE DURING THESE TEMPO PERIODS. CHC -SHRA A COUPLE OF HOURS
BEFORE THE TIME INDICATED IN TAFS.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT THROUGH 15Z. GUSTS
MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: OCCASIONAL GUSTS 20-24 KT THROUGH 15Z. GUSTS
MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE THROUGH
15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE THROUGH
15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KHPN FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL.
KISP FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL AFTER 16Z.
OUTLOOK FOR 12Z TUE THROUGH FRIDAY...
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
728 AM EDT MON OCT 15 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING BREEZY AND WARM WEATHER
TODAY ALONG WITH A ROUND OF SHOWERS...MAINLY LATER THIS AFTERNOON
INTO TONIGHT. DRY AND COOLER WEATHER FOLLOWS TUESDAY THEN A
WARMING TREND WEDNESDAY INTO THURSDAY. MOISTURE WILL INCREASE
ALONG WITH A CHANCE OF SHOWERS BY FRI/SAT AS A COLD FRONT
APPROACHES FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
730 AM UPDATE...
MADE MINOR UPDATES TO ACCOUNT FOR CURRENT TRENDS. TEMPS CONTINUE
TO INCREASE THIS MORNING DUE TO STRONG WAA AHEAD OF APPROACHING
COLD FRONT. INCREASED HIGH TEMPS UP A DEG OR TWO. RADAR IMAGERY
SHOWING LIGHT ECHOES ON THE SCOPE...HOWEVER THESE ARE NOT HITTING
THE GROUND AS TEMP DEWPOINT SPREAD IS TO GREAT...SO POSSIBLE VIRGA
FALLING FROM THE SKY. WINDS HAVE ALREADY STARTED TO GUSTS AND
SEEING JKF VAD PROFILER AT 50 KTS AT 925 MB BELIEVE ANOTHER WINDY
DAY IS IN STORE FOR TODAY. DID A MODEL BLEND OF THE HRRR AND
LAVRUC AS THESE MODELS HAVE BEEN PERFORMING THE BEST IN THE SHORT
TERM THIS MORNING. OTHERWISE FORECAST REMAINS ON TRACK FOR TODAY.
PREV DISCUSSION...
COLD FRONT MOVES EAST FROM THE EASTERN GT LAKES AND WILL APPROACH
WESTERN NEW ENG TOWARD EVENING. MODELS INDICATE A BAND OF DEEP
MOISTURE AND OMEGA AHEAD OF THE FRONT MOVING INTO W ZONES MID TO
LATE AFTERNOON WHICH WILL LEAD TO SHOWERS DEVELOPING. THERE IS
ALSO SOME ELEVATED INSTABILITY SO CANT RULE OUT AN ISOLD TSTM.
WE HAVE INCREASED POPS TO CATEGORICAL CT VALLEY WEST WHERE HIGHEST
PROB OF AFTERNOON SHOWERS...WITH POPS DECREASING TO THE EAST. HAVE
JUST SLIGHT CHC POPS SE MA AND THE CAPE WHERE IT SHOULD REMAIN
MOSTLY DRY TODAY. HOWEVER...AN AREA OF MOISTURE LIFTING NE FROM
THE OCEAN MAY CLIP ACK WITH A FEW SHOWERS THIS AFTERNOON.
CONFIDENCE IS LOW IN THIS OCCURRING AND ANY SHOWERS COULD REMAIN
OFFSHORE.
A RATHER MILD START TO THE DAY WITH SOME SUNSHINE POSSIBLE THIS
MORNING...ESPECIALLY E ZONES WILL LEAD TO A WARM DAY WITH MAXES
REACHING INTO THE LOWER 70S WITH UPPER 60S NW HIGHER TERRAIN. IT
WILL ALSO BE BREEZY AND HUMID WITH DEWPOINTS CLIMBING INTO THE
LOWER 60S NEAR THE COAST ALONG WITH GUSTY SW WINDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...
WIDESPREAD SHOWERS ARE EXPECTED TO MOVE EAST ACROSS SNE TONIGHT AS
THE FRONT MOVES ACROSS THE REGION AND WE HAVE CATEGORICAL POPS.
BRIEF HEAVY RAINFALL IS POSSIBLE AS THERE IS GOOD FORCING FROM
RIGHT ENTRANCE REGION OF STRONG UPPER JET AND PWATS CLIMB TO 1.5"
WHICH IS ABOUT +2SD. THE FRONT WILL BE QUICK MOVING SO DURATION OF
ANY HEAVY RAINFALL WILL BE BRIEF AND NOT LAST MORE THAN A FEW
HOURS. THE SHOWERS SHOULD BE MOVING EAST OF THE CAPE 06-09Z.
TUESDAY...
COLD FRONT WILL BE OFFSHORE WITH GUSTY NW WINDS EXPECTED. MID
LEVEL TROF WILL BE LIFTING NORTH AND EAST OF SNE DURING THE
MORNING SO EXPECT A DRY DAY ALTHOUGH DIURNAL CU WILL DEVELOP. IT
WILL BE A NOTICEABLY COOLER DAY THAN TODAY AS 850 MB TEMPS FALL TO
NEAR 0C WITH MAXES RANGING FROM LOWER 50S NW HIGHER TERRAIN TO
NEAR 60 COASTAL PLAIN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* HIGH PRESSURE FOR MID-WEEK WITH MILD TEMPS.
* PERIODS OF SHOWERS POSSIBLY SOMETIME FRIDAY INTO THE WEEKEND.
DETAILS...
MODELS/PATTERN...
00Z MODELS IN GOOD AGREEMENT FOR THE MID-WEEK BEFORE DIVERGING
FRIDAY INTO THE WEEKEND. UPPER LEVEL RIDGE WILL BUILD IN ACROSS THE
FORECAST REGION BEGINNING TUESDAY NIGHT. THE 00Z ECMWF IS MORE
AMPLIFIED THEN THE GFS...NO MATTER HIGH PRESSURE WILL DOMINATE. MAIN
FOCUS FOR THE LONG TERM IS THE CUT-OFF LOW OVER THE UPPER
MISSISSIPPI VALLEY AND ITS TRENDS FOR LATE WEEK. THERE ARE 2 MAIN
CLUSTERS...THE NAM/GFS WHICH IS THE NORTHERN SOLUTION COMPARED TO
THE UKMET/ECMWF WHICH IS MORE AMPLIFIED. BECAUSE OF THE SPLIT
BETWEEN THE MODELS...CONTINUED PREV FORECAST WITH A SLIGHT TREND
TOWARDS HPC/UKMET/ECMWF. EXPECT CUT OFF LOW TO MOVE OVER NEW ENGLAND
BY FRI/SAT BEFORE EXITING THE REGION BY SUNDAY. BUILDING HIGH
PRESSURE ACROSS THE SOUTHEAST WILL BUILD A RIDGE OVER THE AREA FOR
EARLY NEXT WEEK.
MID-WEEK...HIGH CONFIDENCE
HIGH PRESSURE OVER THE MID-ATLANTIC WILL CONTINUE TO BUILD ACROSS
THE REGION STARTING LATE TUESDAY THROUGH THURSDAY. QUICK MOVING
SHORTWAVE IN THE FLOW WILL BRING SOME CLOUDS TO THE AREA ON WED.
HOWEVER AN EXCELLENT FALL LIKE DAY WITH TEMPS IN THE MID TO UPPER
60S. BELIEVE A FEW 70S MAY SNEAK OUT ACROSS THE SOUTHERN HALF OF THE
AREA...ALL DEPENDENT ON CLOUD COVER AND MIXING POTENTIAL. AS RIDGE
CONTINUE TO BUILD ACROSS THE REGION...STRONG WAA WILL OCCUR
OVERNIGHT WED INTO THURS MORNING. WENT WITH A NON-DIURNAL TREND AS
TEMPS WILL REMAIN STEADY AND/OR INCREASE OVERNIGHT.
HIGH PRESSURE WILL SLIDE SOUTHEAST OF THE CAPE AND ISLAND BY
THURSDAY SWITCHING THE WINDS TO THE SOUTHWEST. TIGHT PRESSURE
GRADIENT FROM AN APPROACHING SYSTEM OUT WEST WILL HELP AID IN GUSTY
WINDS. TEMPS ON THURSDAY MAY BE FORECASTED A TAD TOO LOW AS IT IS
DEPENDENT ON THE APPROACHING SYSTEM...IF IT AMPLIFIES MORE AND THUS
SLOW DOWN OR CONTINUE ITS CURRENT PATH. IF IT SLOWS DOWN THEN THERE
COULD BE TEMPS IN THE LOW TO MID 70S...WILL HAVE TO MONITOR AS
MODELS GET A BETTER HANDLE ON APPROACHING CUT-OFF LOW.
FRIDAY AND BEYOND...LOW CONFIDENCE
HUGE DIFFERENCE IN THE MODELS HAVE LEAD TO LOW CONFIDENCE FOR THE
END OF THE WEEK INTO THE WEEKEND. AS STATED EARLIER CUT-OFF LOW
APPROACH THE REGION SOMETIME LATE IN THE WEEK. CURRENTLY THERE IS A
LARGE PLACEMENT ON THE LOWS LOCATION AS STATED EARLIER. HAVE KEPT
CURRENT FORECAST WITH A TREND TOWARDS HPC SINCE THEY COMBINED THE
ECMWF AND UKMET. CUT OFF LOW WILL BRING A COLD FRONT ACROSS THE
REGION SOMETIME FRIDAY INTO SATURDAY. RAIN MAY BE HEAVY AT TIMES AS
THERE IS PLENTY OF MOISTURE AHEAD OF THE SYSTEM. STAY TUNED TO LATER
FORECAST AS TRACK OF THE SYSTEM COULD CHANGE AS MODELS WILL NOT HAVE
A GOOD SAMPLE ON THE SYSTEM UNTIL TUESDAY...WHEN IT MOVES INTO THE
CONUS.
MODELS ARE SHOWING STRONG HIGH PRESSURE DEVELOPING ACROSS THE
SOUTHEAST AND BUILDING INTO NEW ENGLAND BY EARLY NEXT WEEK. THIS
WILL KEEP THE ABOVE AVG TREND GOING.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT
MODERATE...30 PERCENT TO 60 PERCENT
HIGH...GREATER THAN 60 PERCENT
OVERVIEW...MODERATE CONFIDENCE.
ISOLD MVFR OR EVEN IFR ST/FOG POSSIBLE IN THE UPPER CT VALLEY
THROUGH EARLY THIS MORNING...OTHERWISE MAINLY VFR THROUGH THE MORNING. A
PERIOD OF MVFR/IFR IS LIKELY BY LATE AFTERNOON ACROSS W ZONES AS
BAND OF SHOWERS WITH THE COLD FRONT MOVE THROUGH...THEN SHOWERS
AND LOWER CONDITIONS SPREADING EAST ACROSS REST OF SNE 00-06Z
TONIGHT. LOW PROB OF AN ISOLD TSTM. SW WIND GUSTS TO 30 KT POSSIBLE
TODAY IN THE COASTAL PLAIN. MAINLY VFR TUESDAY.
KBOS TAF...MODERATE CONFIDENCE. A PERIOD OF MVFR CIGS/VSBYS LIKELY
THIS EVENING MAINLY AFT 22Z AS SHOWERS MOVE THROUGH...AND THERE
IS A CHANCE CIGS COULD BRIEFLY DROP TO IFR. SW WIND GUSTS TO 30 KT
POSSIBLE TODAY.
KBDL TAF...MODERATE CONFIDENCE. A PERIOD OF MVFR CIGS/VSBYS LIKELY
LATE AFTERNOON AND EARLY EVENING MAINLY AFT 20Z AS SHOWERS MOVE
THROUGH.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUESDAY NIGHT TROUGH THURSDAY...
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THURSDAY AS HIGH PRESSURE
WILL PREVAIL. GUSTY SW WINDS MAY OCCUR ON THURSDAY REACHING 25 KTS.
FRIDAY INTO THE WEEKEND...
LOW CONFIDENCE. EXPECT MAINLY VFR HOWEVER MAY SEE SOME MVFR TO IFR
CONDITIONS DUE TO SHOWERS EVENTUALLY MOVING INTO THE REGION. VERY
UNCERTAIN ON TIMING.
&&
.MARINE...
HIGH CONFIDENCE. MODEST LOW LEVEL JET ACROSS THE REGION WILL LEAD
TO SW WIND GUSTS TO 25 KT ON THE WATERS TODAY AND HAVE SCA FOR
ENTIRE MARINE AREA. WINDS SHOULD BEGIN TO DIMINISH LATE TODAY AS
THE LLJ MOVES EAST THEN SHIFT TO W/NW LATER TONIGHT BEHIND FROPA.
THE POST FRONTAL COLD AIR ADVECTION WILL LEAD TO ANOTHER SURGE OF
NW GUSTS TO NEAR 25 KT ON TUE.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUESDAY NIGHT...HIGH CONFIDENCE IN SCA WIND GUSTS ACROSS THE OPEN
WATERS WITHIN THE COOL ADVECTION PATTERN.
WEDNESDAY AND THURSDAY...MODERATE CONFIDENCE. WEAK RIDGE OF HIGH
PRESSURE SHOULD KEEP WINDS BELOW SCA LEVELS. HOWEVER...TROPICAL
STORM RAFAEL WHICH IS EXPECTED TO BECOME A HURRICANE WILL PASS WELL
TO THE EAST OF SOUTHERN NEW ENGLAND. THIS WILL LIKELY RESULT IN
EASTERLY SWELL AND SCA SEAS ACROSS OUR OUTER-WATERS WED INTO THU.
FRIDAY...LOW CONFIDENCE. SCA CONDITIONS MAY DEVELOP AHEAD OF AN
APPROACHING COLD FRONT BUT VERY UNCERTAIN ON THE TIMING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR
ANZ230>234-236-251.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...KJC/DUNTEN
NEAR TERM...KJC/DUNTEN
SHORT TERM...KJC
LONG TERM...DUNTEN
AVIATION...KJC/DUNTEN
MARINE...KJC/DUNTEN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
654 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL SLOWLY APPROACH THE TRI-STATE REGION TODAY...AND
PASS TONIGHT. GUSTY WINDS WILL USHER IN A COOLER AIRMASS FOR
TUESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY NIGHT
THROUGH THURSDAY...BEFORE MOVING EAST OF THE AREA THURSDAY NIGHT.
A STORM SYSTEM MAY IMPACT THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS LOCATED IN WESTERN PENNSYLVANIA THIS MORNING. THE
CWA WILL REMAIN IN THE WARM SECTOR BEFORE THE FRONT ARRIVES.
CLOUDS HAVE OVERSPREAD MUCH OF THE CWA...HOWEVER IT WILL TAKE
SLIGHTLY LONGER FOR PRECIPITATION TO MOVE IN.
H3 JET WILL SLOWLY APPROACH FROM THE W TODAY. THIS WILL AID IN
THE DEVELOPMENT OF RAIN ALONG AND AHEAD OF THE FRONT. MODELS VERY
CLOSE WITH TIMING AND PLACEMENT AND A BLEND WAS USED FOR THE FCST.
MAIN BAND OF PCPN APPEARS TO COME THRU IN THE LATE AFTN AND EVE IN
ASSOCIATION WITH THE RR QUAD OF THE JET. CAPE IS WEAK AND SKINNY.
WITH STRONG WINDS IN THE MID TO UPR LVLS...EXPECT ANY UPDRAFTS TO
BE SHEARED APART. WILL THEREFORE NOT FCST TSTMS. TEMPS TODAY CLOSE
TO THE BCMAV/LAV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
RAIN TRAVERSES THE CWA FROM W TO E TNGT. WINDS SHIFT TO THE NW
AND THE PCPN CUTS OFF AFT FROPA. FRONT AND PCPN TIMED TO CLEAR ERN
ZONES BEFORE SUNRISE TUE. TEMPS CLOSE TO THE MET WITH WINDS
STAYING UP. MAV APPEARS TOO COLD BASED ON UPSTREAM TEMPS CURRENTLY
BEING RECORDED.
SUNNY AND BREEZY ON TUE WITH A 1015 HIGH OVER THE SERN CONUS AND A
990 LOW OVER THE MARITIMES. HIGHS BLW CLIMO BY A FEW DEGREES WITH
H85 TEMPS IN THE LOW SINGLE DIGITS C.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS INTO THE REGION TO START THE LONG TERM PERIOD
TUESDAY NIGHT. THIS HIGH IS FORECAST TO REMAIN OVER THE REGION
THROUGH THURSDAY MORNING...PROVIDING THE LOCAL AREA WITH FAIR AND DRY
CONDITIONS. A WEAK SHORTWAVE PASSING NORTH OF THE REGION COULD
PROVIDE THE AREA WITH SOME CLOUDS WEDNESDAY...OTHERWISE WE ARE
LOOKING FOR MOSTLY CLEAR CONDITIONS.
THE HIGH WILL MOVE OFF TO THE EAST THURSDAY AFTERNOON AND
EVENING...WITH THE ARRIVAL OF THE NEXT STORM SYSTEM. WITH MODEL
DISCREPANCIES...HAVE NOT MADE ANY SIGNIFICANT CHANGES TO THE
FORECAST.
THE EC/CMC MEANS ARE FURTHER S WITH THE UPPER LOW NEAR IOWA ON
THU WHILE THE GFS MEAN IS CLOSER TO LAKE SUPERIOR. THE
DETERMINISTIC MODELS SUPPORT THE SLOWER FURTHER S SOLN AND THIS
GENERAL IDEA WAS FOLLOWED ALTHOUGH HAVE NOT TOTALLY DISREGARDED
THE FASTER GFS. LONG PERIOD OF POPS STARTING THU NIGHT AND
CONTINUING RIGHT THROUGH SUN. THIS IS MAINLY DUE TO THE TIMING
DISCREPANCIES AND SHOULD NARROW IN THE COMING DAYS. HOWEVER...DUE
TO THE SLOW NATURE OF THIS SYSTEM...A SIGNIFICANT RAINFALL IS
POSSIBLE NEXT WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A COLD FRONT APPROACHES FROM THE WEST TODAY BEFORE PASSING THROUGH
LATE IN THE DAY INTO THIS EVENING.
S/SW WINDS AVERAGING MOSTLY 10-15 KT WITH GUSTS AROUND 20 KT BECOME
SLIGHTLY LIGHTER THIS AFTERNOON AND LESS GUSTY. WIND SHIFT TO NW
ARRIVES CLOSE TO MIDNIGHT.
PRIMARILY VFR. CIGS COULD POSSIBLY PREVAIL 1500-3000 FT DURING THE
TIME WHERE TEMPO GROUPS WITH SHRA ARE IN THE TAFS. AN ISOLATED
THUNDERSTORM IS ALSO POSSIBLE DURING THESE TEMPO PERIODS...BUT NOT
ENOUGH PROBABILITY AND COVERAGE TO MENTION IN THE FORECAST AT THIS
TIME. SHOWERS WILL ALSO BE POSSIBLE A COUPLE OF HOURS BEFORE THE
TIME INDICATED IN TAFS.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE THROUGH
15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KLGA FCSTER COMMENTS: OCCASIONAL GUSTS AROUND 20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KTEB FCSTER COMMENTS: OCCASIONAL GUSTS 16-20 KT POSSIBLE FROM
12Z-15Z. GUSTS MAY ALSO ONLY BE OCCASIONAL AFTER 15Z.
KHPN FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL.
KISP FCSTER COMMENTS: GUSTS MAY ONLY BE OCCASIONAL AFTER 16Z.
OUTLOOK FOR 06Z TUE THROUGH FRIDAY...
.MONDAY NIGHT...VFR. OCCASIONAL NW GUSTS AROUND 20 KT.
.TUESDAY...VFR. NW GUSTS AROUND 25 KT.
.WEDNESDAY-THURSDAY...VFR.
.FRIDAY...S GUSTS 20-25 KT. CHC SHRA/CIGS BLO 3KFT IN RAIN.
&&
.MARINE...
SCA CONDITIONS WILL CONTINUE TODAY ON S WINDS. WINDS WILL DECREASE
A BIT TNGT...BUT SEAS WILL REMAIN ELEVATED ON THE OCEAN. WILL
ALLOW THE SCA TO END ON THE PROTECTED WATERS THIS EVE...AND
MAINTAIN IT ON THE OCEAN. EXTENDED THE SCA ON THE OCEAN THRU TUE
WITH INCREASING NW WINDS. CONDITIONS WILL BE CLOSE TO SCA LVLS ON
THE REMAINDER OF THE WATERS...SO AN ADVY IS POSSIBLE FOR TUE.
WINDS WILL GRADUALLY FALL BELOW SCA LEVELS TUESDAY NIGHT AND
REMAIN BELOW SCA LEVELS THROUGH AT LEAST THURSDAY WITH A WEAK
PRESSURE GRADIENT ACROSS THE AREA.
WINDS INCREASE ON FRIDAY AND SHOULD REMAIN UP THROUGH THE WEEKEND AS
A STORM SYSTEM APPROACHES AND MOVES ACROSS THE AREA WATERS. QUESTION
REMAINS ON THE EXACT TIMING OF WHEN THE SMALL CRAFT ADVISORY WINDS
IMPACT THE AREA WATERS...WHICH WILL DEPEND ON HOW THE STORM SYSTEM
EVOLVES COMING OUT OF THE MID-SECTION OF THE COUNTRY.
SEAS ON THE OCEAN WATERS ARE A DIFFERENT STORY. INCREASING SWELLS
FROM RAFAEL COULD KEEP SEAS ABOVE 5 FT THROUGH THE FORECAST PERIOD.
FOR THE LATEST ON RAFAEL...PLEASE REFER TO PRODUCTS ISSUED BY THE
NATIONAL HURRICANE CENTER.
&&
.HYDROLOGY...
3/4 OF AN INCH OR LESS OF RAIN IS EXPECTED THRU TNGT. FLOODING IS
NOT EXPECTED. DRY WEATHER TUE THRU AT LEAST THU.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...BC/JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...BC
AVIATION...JC
MARINE...BC/JMC
HYDROLOGY...JMC
AREA FORECAST DISCUSSION
NWS MIAMI FL
1135 AM EDT MON OCT 15 2012
.UPDATE...
OUTSIDE OF A FEW MINOR UPDATES WITHIN THE GRIDDED FORECAST
DATABASE BASED ON THE LATEST OBSERVATIONS AND RADAR TRENDS...THE
PREVIOUS FORECAST REMAINS ON TRACK. THE FOG THAT OCCURRED THIS
MORNING ACROSS WESTERN COLLIER COUNTY HAS LIFTED OR BURNED OFF.
THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTHWEST FROM GEORGIA TO LOUISIANA WITH PLENTY OF DRY AIR
OVERSPREADING THE REGION IN ITS WAKE. OUT AHEAD OF THIS BOUNDARY
OVER OUR AREA...MOISTURE AND DEWPOINTS HAVE INCREASED OVER THE
PAST DAY. THE MORNING UPPER SOUNDING IN MIAMI SHOWED A
PRECIPITABLE WATER VALUE OF 1.51 INCHES...WHICH IS FORECAST TO
CONTINUE TO INCREASE SLIGHTLY THROUGH TONIGHT ACROSS THE AREA.
THIS INCREASE IN MOISTURE COMBINED WITH DIURNAL HEATING AND LOCAL
SEA BREEZES WILL BE ENOUGH TO TRIGGER SCATTERED SHOWERS THIS
AFTERNOON AND ISOLATED TSTMS. THE LATEST HRRR AND WRF MODEL
REFLECTIVITIES SHOW SIMILAR RESULTS AND INDICATE MAINLY ISOLATED
TO SCATTERED AFTERNOON COVERAGE FAVORING THE INLAND AND WEST GULF
COAST AREAS TODAY.
THERE WAS A REPORT OF SOME MINOR STREET FLOODING IN THE SOUTH
BEACH AREA ALONG PURDY AVE/20TH STREET DURING THE HIGH TIDE CYCLE
THIS MORNING. THIS IS MOSTLY CONTRIBUTED TO THE PERIGEAN SPRING
TIDE AND WATER LEVELS RUNNING SLIGHT ABOVE NORMAL. EXPECT THIS
POTENTIAL TO CONTINUE AT EACH HIGH TIDE CYCLE THROUGH TUESDAY OR
WEDNESDAY BEFORE SUBSIDING. ALTHOUGH THE THREAT IS LOW...ANY
ADDITIONAL RAINFALL THAT BECOMES CONCENTRATED OVER THESE AREAS MAY
LEAD TO ADDITIONAL FLOODING OR STANDING WATER CONCERNS THROUGH
THIS TIME. THE NEXT HIGH TIDE CYCLE WILL COME LATER THIS EVENING
BETWEEN 8 AND 9 PM. 85/AG
&&
.PREV DISCUSSION... /ISSUED 721 AM EDT MON OCT 15 2012/
AVIATION...
SCATTERED SHOWERS OVER THE ATLANTIC IN MOIST E-NE LOW LEVEL WIND
FLOW WILL AFFECT PORTIONS OF E COAST THROUGH 16Z. THIS WILL KEEP
SHOWERS IN THE VICINITY OF MOST EAST COAST TERMINALS WITH BRIEF MVFR
CONDITIONS POSSIBLE BUT NOT ENOUGH TO PUT IN TAFS. ALONG WEST COAST
AT KAPF, PATCH OF BKN/OVC STRATUS BELOW 1000 FT FORECAST SLOWLY BURN
OFF BY AROUND 13Z, ALTHOUGH WOULDN`T BE SURPRISED IF LOW CEILINGS
LINGER UNTIL PERHAPS 14Z DUE TO LIGHT WINDS AND PERSISTENT NATURE OF
THE CLOUD DECK. SLIGHTLY DRIER AIR WILL TRY TO MOVE INTO SOUTH
FLORIDA AFTER 18Z, BUT WILL KEEP VCSH ALL SITES IN LIGHT NE FLOW.
EXPECT A FEW TSTMS OVER THE INTERIOR OF THE PENINSULA 17Z-00Z BUT THESE
WILL BE ISOLATED ENOUGH TO NOT MENTION AT TAF SITES. GULF SEA BREEZE
FORECAST TO AFFECT KAPF BY 18Z WITH NW WINDS. DRIER N-NE WIND FLOW
00Z-12Z TUESDAY.
PREV DISCUSSION... /ISSUED 345 AM EDT MON OCT 15 2012/
DISCUSSION...
SOME DRIER AIR HAS ALREADY BEGUN TO MOVE INTO THE AREA FROM THE EAST
WITH GPS MET DATA SHOWING THE PWAT DOWN TO 1.5-1.6 INCHES ALONG THE
ATLANTIC COAST BUT STILL 1.8-2.0 INCHES FROM THE LAKE TO NAPLES.
EVEN WITH SOME DRYING FROM THE EAST TODAY, MOISTURE WILL BE
SUFFICIENT, ALONG WITH DEVELOPING SEA BREEZES DUE TO A LIGHTER
SYNOPTIC SCALE WIND FLOW, TO ALLOW FOR SCATTERED SHOWERS TO DEVELOP
ACROSS THE AREA. THE FOCUS IS EXPECTED TO BE ACROSS THE EAST COAST
THROUGH EARLY AFTERNOON, BEFORE SHIFTING TO THE INTERIOR/GULF COAST
LATER IN THE DAY. HAVE GONE WITH THE HIGHEST POPS OVER THE INTERIOR
WHERE THE BEST CONVERGENCE IS EXPECTED. THERE COULD BE A FEW
THUNDERSTORMS AS WELL TODAY, ESPECIALLY OVER THE INTERIOR LATE THIS
AFTERNOON. GFS/ECMWF/SREF ARE IN GENERAL AGREEMENT ON THIS
SCENARIO...AND ACTUALLY OVER THE NEXT FEW DAYS.
ONSHORE WINDS ALONG THE ATLANTIC COAST WILL CONTINUE TO RELAX, BUT
THERE IS STILL A MODERATE RISK OF RIP CURRENTS. THE WEAKER ONSHORE
WINDS MAY PRECLUDE ANY COASTAL FLOODING DESPITE HIGH TIDAL LEVELS.
THIS WILL BE MONITORED OVER THE NEXT COUPLE OF DAYS AS WE ARE IN THE
SPRING TIDE WHICH RESULTS IN HIGHER THAN NORMAL WATER LEVELS.
THIS EVENING AND THROUGH TUESDAY, FURTHER DRYING IS EXPECTED TO
ENTER INTO SOUTH FL FROM THE NORTH. A SHORTWAVE WILL BE PASSING BY
TO THE NORTH TODAY FOLLOWED BY A WEAKENING FRONTAL BOUNDARY MOVING
INTO THE AREA TONIGHT AND BECOMING DIFFUSE OVER OR JUST SOUTH OF THE
AREA ON TUESDAY WHILE WASHING OUT. PWATS ARE FORECAST TO FALL INTO
THE 1.2-1.5 INCH RANGE ON TUESDAY. HOWEVER, LINGERING LOW LEVEL
MOISTURE COULD STILL ALLOW FOR ISOLATED SHOWERS ACROSS THE EAST
COAST, SO KEPT SLIGHT CHANCE POPS EAST HALF FOR TUESDAY.
THE RIP CURRENT RISK ALONG THE ATLANTIC COAST WILL CONTINUE TO
SUBSIDE OVER THE NEXT FEW DAYS. HOWEVER, ONE CAVEAT IS THAT THE
SWAN MODEL IS SHOWING A 15 SECOND EASTERLY SWELL MOVING THROUGH
THE PROVIDENCE CHANNEL OF THE BAHAMAS AND REACHING THE SOUTHERN
PALM BEACH COAST TUE AFTERNOON. GRANTED, RIGHT NOW THE MODEL ONLY
SHOWS A SWELL HEIGHT OF 2 FT, BUT THIS COULD END UP SLIGHTLY
HIGHER. EVEN SO, GIVEN THE LONG PERIOD OF THE SWELL (15 SEC),
ROUGH SURF/DANGEROUS RIP CURRENTS COULD BRIEFLY OCCUR ACROSS SE
PALM BEACH COUNTY ON TUESDAY AFTERNOON/EVENING.
ANOTHER SHORTWAVE DIGS INTO THE GULF AND APPROACHES SOUTH FL ON WED,
WITH MOISTURE INCREASING IN ADVANCE OF THIS TROUGH. SEA BREEZE
CONVERGENCE IS EXPECTED WED, AND WITH THE HIGHER MOISTURE, THERE`S A
BETTER CHANCE OF SHOWERS AND A FEW THUNDERSTORMS ESPECIALLY
INTERIOR-EAST ON WED...DUE TO A MEAN WESTERLY STORM STEERING FLOW.
FOR LATE WEEK INTO NEXT WEEKEND, BOTH GFS/ECMWF SHOW A STRONG CLOSED
MID/UPPER LOW DIVING ACROSS THE GREAT LAKES STATES WITH A TROUGH
EXTENDING SOUTH INTO THE GULF OF MEXICO. BOTH MODELS SHOW WARM,
HUMID CONDITIONS LATE WEEK AHEAD OF THIS SYSTEM AND JUST CANNOT
SHUT MENTION OF SHOWERS/TSTORMS OFF ANY DAY DUE TO SUFFICIENT
MOISTURE/INSTABILITY CONTINUING...ESPECIALLY OVER THE WEEKEND.
BOTH MODELS HAVE BEEN GRADUALLY BACKING OFF ON THE THRUST OF THIS
COLD FRONT FOR SOUTH FLORIDA...ESPECIALLY NOW THE GFS WHICH KEEPS
DEWPOINTS IN THE LOWER 70S ALL THE WAY THROUGH NEXT WEEKEND AND
INTO NEXT WEEK. THE ECMWF SHOWS SLIGHTLY DRIER AIR BEHIND THE
BOUNDARY BY MONDAY...BUT EVEN IT SHOWS WINDS QUICKLY TO THE EAST
BEHIND IT. SO THE BOTTOM LINE IS WARM, HUMID CONDITIONS LOOK TO
PREVAIL THROUGH THE FORECAST PERIOD ALONG WITH DAILY CHANCES OF
SHOWERS/TSTORMS.
MARINE...WINDS ARE CONTINUING TO DECREASE ACROSS THE LOCAL
WATERS. SWAN OUTPUT SHOWS SIG WAVEHEIGHT OF 7 FT EARLY THIS
MORNING OVER THE PALM BEACH WATERS BEFORE DECREASING THROUGHOUT
THE DAY. SO WILL CONTINUE THE SMALL CRAFT ADVISORY FOR JUST THE
PALM BEACH WATERS THROUGH 8 AM THIS MORNING. THEN SEAS OF 4 FT OR
LESS ARE EXPECTED THROUGH LATE WED BEFORE EVEN LOWERING FURTHER
LATE WEEK AS LIGHT WINDS PREVAIL.
SWAN SHOWS A LONG PERIOD (15 SECONDS) SWELL MOVING THROUGH THE
PROVIDENCE CHANNEL ONSHORE SOUTHERN PALM BEACH COUNTY TUE
AFTERNOON-NIGHT, UP TO 2 FT. THIS IS ORIGINATING FROM
TROPICAL STORM RAFAEL MOVING NNW WELL TO OUR EAST ALONG ABOUT 65
DEGREES WEST LONGITUDE. WILL HAVE TO WATCH THIS FOR A BRIEF PERIOD
OF POTENTIALLY ROUGH SURF/RIP CURRENTS ALONG THE SOUTHERN PALM
BEACH COAST.
FIRE WEATHER...NO CONCERNS AS RH`S REMAIN ELEVATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 74 86 71 / 30 10 20 20
FORT LAUDERDALE 88 76 87 74 / 30 10 20 20
MIAMI 88 75 87 73 / 30 10 20 20
NAPLES 88 72 86 71 / 30 20 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...55/CWC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
618 AM CDT MON OCT 15 2012
.AVIATION...12Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS
EXPECTED THROUGH THE PERIOD WITH WINDS GENERALLY 10KTS OR LESS.
COULD SEE A SMALL WINDOW AT KOFK WITH WINDS OF 12 TO 15KTS BY LATE
MORNING THROUGH THE AFTERNOON. A SURFACE TROUGH APPROACHES THE
AREA LATE TONIGHT...WITH A WIND SHIFT TO THE NORTHWEST EXPECTED AT
KOFK BY 10Z...AND NOT UNTIL TUESDAY MORNING BY 15 TO 18Z JUST
BEYOND THIS TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 332 AM CDT MON OCT 15 2012/
DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE HIGH TEMPERATURES OVER THE NEXT
COUPLE DAYS AND PRECIPITATION CHANCES TUESDAY NIGHT INTO MID
WEEK.
LATEST WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWS THE NATIONS
MID SECTION IN NORTHWEST FLOW LYING IN BETWEEN A TROUGH TO OUR
EAST AND A WEAK RIDGE TO THE WEST. SHORTWAVE ENERGY CURRENTLY OVER
THE NORTHWEST CONUS IS FORECAST TO RIDE DOWN THE WEAK RIDGE AND
TOWARD CENTRAL NEBRASKA BY 06Z TONIGHT. AS WEAK SFC LOW PRESSURE
MOVES ACROSS THE NRN PLAINS AHEAD OF THIS UPPER SHORTWAVE...THE
FORECAST AREA WILL BE UNDER WEAK SOUTHERLY SFC FLOW. COMBINED WITH
LOW LEVEL WARM AIR ADVECTION THROUGHOUT THE DAY...TODAY WILL BE
VERY MILD WITH HIGHS APPROACHING UPPER 70S TO NEAR 80. STRONGER
MIXING IS LIKELY ON TUESDAY AHEAD OF AN APPROACHING COOL FRONT IN
ADVANCE OF ABOVE MENTIONED UPPER LEVEL SHORTWAVE. HIGHS SHOULD
APPROACH 80 ONCE AGAIN WITH SLIGHTLY COOLER READINGS IN OUR FAR
NORTHERN COUNTIES BEHIND THE COOL FRONT.
A STRONGER UPPER LEVEL SHORTWAVE TROUGH WILL PUSH ACROSS MONTANA AND
CLOSE OFF AS IT SKIRTS THE NORTH DAKOTA/CANADIAN BORDER MID WEEK.
THIS WILL PUSH A STRONGER COLD FRONT INTO THE FORECAST AREA BY
WEDNESDAY MORNING. INCREASING MOISTURE AND FRONTOGENETICAL FORCING
SHOULD BE ENOUGH TO GENERATE LIGHT PCPN BEHIND THE SURFACE FRONT
THROUGH THE DAY WEDNESDAY. INCREASING PRESSURE GRADIENT BEHIND THE
BOUNDARY WILL CREATE BREEZY IF NOT WINDY CONDITIONS THROUGH THE
DAY WEDNESDAY.
THE UPPER CLOSED LOW WILL CONTINUE TO SINK SOUTHEAST AND DEEPEN AS
IT MOVES INTO THE GREAT LAKES REGION LATE IN THE SCHOOL/WORK WEEK.
DEPENDING ON LOCATION AND TIMING...AREA COULD SEE RAIN SHOWERS SINK
SOUTH INTO THE CWA AROUND THE BACKSIDE OF THE UPPER LOW. ALREADY HAD
POPS GOING FOR THURSDAY SO WILL CONTINUE. ALSO LOOKS AS THOUGH SFC
PRESSURE GRADIENT WILL REMAIN QUITE STRONG WHILE 850MB NORTHWEST
WINDS ARE FORECAST AROUND 45-55KTS. SOME OF THIS WOULD LIKELY MIX
DOWN AND CREATE QUITE BLUSTERY CONDITIONS THROUGH LATE WEEK.
QUIET AND WARMER CONDITIONS ARE EXPECTED INTO THE WEEKEND.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DEWALD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1015 AM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE CAROLINAS AND SOUTHERN VIRGINIA THIS
AFTERNOON AND THIS EVENING. COOL HIGH PRESSURE WILL BUILD INTO THE
REGION IN THE WAKE OF THE FRONT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM MONDAY...
FOR THE REST OF TODAY:
THE LATEST SURFACE MAP DEPICTS THE COLD FRONT STILL BACK OVER FAR
ERN TN... MOVING SLOWLY EASTWARD. JUST OFF THE SURFACE... 35-40 KT
SWRLY JET AT 925 MB AND 40-50 KT JETTING AT 850 MB STRETCHES FROM
WRN NC INTO NEW ENGLAND. FURTHER ALOFT... DEEP MID LEVEL TROUGHING
FROM ONTARIO THROUGH MI TO LA WILL SWING EASTWARD AND DEEPEN FURTHER
TODAY... SPREADING INTENSE HEIGHT FALLS (80-120 METERS IN 12 HRS)
OVER NC/VA LATER TODAY. THIS TROUGH`S APPROACH WILL STRENGTHEN THE
UPPER JET OVER MD/PA/NY THIS AFTERNOON... INSTIGATING STRONG UPPER
DIVERGENCE OVER CENTRAL/ERN NC... JUST AHEAD OF STRONG MID LEVEL
DPVA.
THE RISK OF SHOWERS AND STORMS GENERATING STRONG WIND GUSTS WILL
PERSIST THROUGH THE AFTERNOON. AN INITIAL BROAD BAND OF HEAVY
SHOWERS AND STORMS MOVING THROUGH THE TRIAD AND WRN PIEDMONT APPEARS
TO BE LINKED TO A MID LEVEL WAVE NOTED ON WATER VAPOR IMAGERY
PUSHING THROUGH THE SRN/CENTRAL MOUNTAINS/FOOTHILLS. AS THIS FEATURE
CONTINUES TO LIFT RAPIDLY NE... THIS HEAVY PRECIP AREA SHOULD
LIKEWISE TRANSLATE NNE INTO VA... LEAVING BEHIND A THIN BROKEN LINE
OF WEAKER SHOWERS FOR A FEW HOURS. AS THE UPPER DIVERGENCE
STRENGTHENS WITH THE APPROACH OF THE SURFACE FRONT BY EARLY TO MID
AFTERNOON... THE IMPROVING DYNAMICS WILL COINCIDE WITH MARGINAL
DESTABILIZATION (800-1200 J/KG MLCAPE)... AND REDEVELOPMENT OF A
BAND OF STORMS OVER THE CENTRAL/ERN PIEDMONT APPEARS LIKELY JUST
AHEAD OF THE FRONT... A SCENARIO DEPICTED BY THE LATEST HRRR MODEL
RUNS. FORECAST RAIN CHANCES FOR TODAY REFLECT SUCH A TIMING SCENARIO
FAIRLY WELL AND ONLY SMALL CHANGES ARE NEEDED.
THE LOW LEVEL JET IS EXPECTED TO WEAKEN A BIT OVER NC AS THE HEART
OF THE JET LIFTS TO OUR NORTH... HOWEVER THE OTHERWISE FAVORABLE
KINEMATICS COMBINED WITH LARGER SCALE FORCING ROOTED IN THE UPPER
LEVELS... STILL-FORMIDABLE LOWER LEVEL MASS CONVERGENCE... 30-40 KTS
OF DEEP LAYER SHEAR... AND MARGINAL INSTABILITY MAY LEAD TO A FEW
DISCRETE BOWING SEGMENTS EMBEDDED WITHIN THE LARGER LINE OF
CONVECTION. BACKGROUND WINDS ALONE WILL SUPPORT PERIODIC GUSTS OF
25-30 KTS WITH ANY CONVECTION... AND STRONGER GUSTS OVER 45 KTS
REMAIN POSSIBLE IN CONJUNCTION WITH ANY BOWING SEGMENTS OR DISCRETE
CELLS. FAIRLY MEAGER MID LEVEL LAPSE RATES WILL PRECLUDE A MAJOR
HAIL THREAT... PARTICULARLY CONSIDERING THE LACK OF A BROAD "FAT"
CAPE TO SUPPORT ESPECIALLY VIGOROUS UPDRAFTS... ALTHOUGH IF WE CAN
GET A FEW HOURS OF SUNSHINE IN THE COASTAL PLAIN... POCKETS OF
HIGHER CAPE AND STRONGER DIFFERENTIAL HEATING COULD INTENSIFY
CONVECTION THERE. FINALLY... TRAINING OF SHOWERS AND STORMS
PARTICULARLY OVER URBAN AREAS COULD LEAD TO LOCALIZED FLOODING
PROBLEMS IN SUSCEPTIBLE LOCATIONS THROUGH THIS AFTERNOON. WILL MAKE
APPROPRIATE ADJUSTMENTS TO THE HAZARDOUS WEATHER OUTLOOK TO REFLECT
THIS.
TEMPS ARE A CHALLENGE GIVEN THE STEADY PRECIP OVER THE WRN CWA
BALANCED WITH THE STRONG WARM AIR ADVECTION. WILL MAKE A MINOR
DOWNWARD ADJUSTMENT MAINLY IN THE WEST WHERE READINGS HOLD IN THE
LOW-MID 60S. OVERALL... EXPECT HIGHS NEAR 70 TO THE MID 70S. -GIH
TONIGHT...WITH FROPA OCCURRING LATER THIS AFTERNOON THROUGH EARLY
EVENING AND STRONG SUBSIDENCE NOTED BEHIND THE FRONT...EXPECT
SHOWERS TO END QUICKLY WITH THE FRONTAL PASSAGE...WITH SKIES
CLEARING SHORTLY AFTER. STEADY NW FLOW OVERNIGHT WILL USHER A COOLER
AND DRIER AIR MASS INTO THE REGION. MOS GUIDANCE ACCEPTED WITH MINOR
TWEAKS. -WSS
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 255 AM MONDAY...
TUESDAY AND TUESDAY NIGHT...SURFACE HIGH PRESSURE WILL BUILD INTO
AND CROSS THE REGION. 850MB THERMAL TROUGH OVER THE AREA THROUGH
TUESDAY NIGHT. THIS RESULTS IN THICKNESSES IN THE MID 1360S TUESDAY
AFTERNOON...ABOUT 10-12M BELOW NORMAL. THIS SUPPORTS MAX TEMPS ABOUT
3-5 DEGREES COOLER THAN NORMAL. MAX TEMPS TUESDAY MID 60S N-NW TO
AROUND 70 SOUTH.
SURFACE RIDGE EXTENDS ACROSS REGION TUESDAY NIGHT. THIS WOULD
SUGGEST SURFACE WINDS DECOUPLING NEAR SUNSET. WOULD NORMALLY EXPECT
CLEAR SKIES IN THIS REGIME BUT SEVERAL OF THE MODELS DEPICT AN
INCREASE IN HIGH LEVEL MOISTURE ASSOCIATED WITH A MID-UPPER S/W IN
THE WLY FLOW ALOFT. THE GFS QUITE MOIST ABOVE 500MB...DEPICTING A
SOLID VEIL OF CIRRUS. THE ECMWF AND NAM NOT AS ROBUST BUT DO HINT AT
POTENTIAL FOR HIGH LEVEL CLOUDINESS. THUS...EXISTENCE OF CIRRUS
SHIELD MAY BE ENOUGH TO PREVENT SURFACE AIR MASS FROM REALIZING FULL
COOLING POTENTIAL. WILL FORECAST MIN TEMPS IN THE 40-45 DEGREE
RANGE. IF CIRRUS SHIELD THINNER THAN ANTICIPATED...THIS WOULD LEAD
TO COOLER MIN TEMPS AND SOME UPPER 30S PROBABLE AT THE NORMALLY
COLDER SITES. -WSS
WEDNESDAY AND WEDNESDAY NIGHT:
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OFFSHORE ON WEDNESDAY
ALLOWING FOR A WARMING SOUTHERLY RETURN FLOW TO DEVELOP. HOWEVER...
THIS MAY BE TEMPERED A BIT BY A WEAK S/W ALOFT TRACKING ACROSS THE
AREA WEDNESDAY MORNING INTO AFTERNOON (WITH THE STRONGEST PORTIONS
OF THE IMPULSE STAYING TO THE SOUTH OF THE AREA). THIS SHOULD ALOFT
FOR A PERIOD OF SCATTERED TO BROKEN MID/HIGH LEVEL CLOUDS ON
WEDNESDAY MORNING INTO THE AFTERNOON... WITH CLEARING SKIES FROM NW
TO SE IN THE AFTERNOON TO LATE AFTERNOON. NOT EXPECTING ANY PRECIP
WITH THIS FEATURE AS PW`S WILL REMAIN GENERALLY NEAR OR BELOW 0.60".
AFTERNOON LOW LEVEL THICKNESS VALUES ARE EXPECTED TO TOP OUT IN THE
1365 TO 1370 METER RANGE. THIS SHOULD GENERALLY YIELD TEMPS FROM THE
LOWER TO MID 70S ACROSS THE AREA.
WEDNESDAY NIGHT EXPECT SKIES WILL GENERALLY BE MOSTLY CLEAR OUTSIDE
OF SOME INCREASING HIGH LEVEL CLOUD COVER AHEAD OF THE NEXT SYSTEM
EXPECTED TO AFFECT THE AREA IN THE EXTENDED PORTION OF THE FORECAST.
HOWEVER... WITH THE SURFACE HIGH TO THE EAST OF THE AREA EXPECT
OVERNIGHT LOWS WILL NOT BE AS COOL/COLD AS THE PREVIOUS NIGHT.
THUS... WILL GO WITH LOWS THURSDAY MORNING IN THE UPPER 40S TO LOWER
50S. -BSD
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT SHOWING A CLOSED LOW
DEVELOPING/MOVING INTO THE UPPER MIDWEST AND GREAT LAKES REGION LATE
WEEK... CREATING A FULL LATITUDE TROUGH OVER THE EASTERN HALF OF THE
COUNTRY. HOWEVER... MODELS CONTINUE TO STRUGGLE WITH THE PROGRESSION
OF THIS SYSTEM.
AS THE ABOVE MENTIONED UPPER LOW SLOWLY SHIFTS EASTWARD AND
EVENTUALLY BEGINS TO LIFT NORTH-NORTHEASTWARD EXPECT AN ASSOCIATED
COLD FRONT WILL APPROACH CENTRAL NC ON THURSDAY... MOVING INTO THE
AREA SOMETIME IN THE LATE THURSDAY TO FRIDAY TIMEFRAME. MODELS
CONTINUE TO STRUGGLE WITH THE TIMING OF THE FRONT AND ITS
PROGRESSION THROUGH THE AREA... WITH THE OPERATIONAL 00Z GFS AND
CANADIAN SHOWING THE LEADING FRONT TO THE EAST OF THE AREA BY MID TO
LATE FRIDAY. WITH THE 12Z HIRES ECMWF SHOWING THE FRONT STILL TO THE
WEST OF THE AREA AT THIS TIME (ECMWF MOVES THE FRONT SLOWLY THROUGH
THE AREA FROM FRIDAY NIGHT TROUGH SATURDAY AFTERNOON). THUS... MUCH
UNCERTAINTY STILL EXISTS FOR THE THURSDAY NIGHT THROUGH SATURDAY
TIMEFRAME. HOWEVER... WITH THE 00Z LOWRES ECMWF SHOWING THE FRONT
MOVING THROUGH THE AREA A BIT QUICKER THAN PREVIOUSLY INDICATED WILL
NARROW THE TIME RANGE FOR CHANCE POPS DOWN A BIT AND ACCORDINGLY
ADJUST TEMPS TO FIT A BIT FASTER FRONTAL PASSAGE THAN PREVIOUSLY
INDICATED... WITH DRY WEATHER RETURNING BY MID/LATE SATURDAY THROUGH
SUNDAY AS SURFACE HIGH PRESSURE BUILDS BACK INTO THE REGION. FOR NOW
WILL GO WITH CHANCE POPS THURSDAY NIGHT INTO FRIDAY NIGHT... WITH
ONLY A SLIGHT CHANCE FOR SATURDAY WITH THE POTENTIAL OF THE SLOWER
ECMWF AND POSSIBLE POST FRONTAL PRECIP.
EXPECT HIGH TEMPS ON THURSDAY WILL RANGE FROM THE LOWER 70S IN THE
NW TO NEAR 80 IN THE SE... WITH THE POTENTIAL FOR HIGHS TO BE A BIT
COOLER IN THE NW IF THE MORE PROGRESSIVE SET OF GUIDANCE IS CORRECT
AND MOVES THE FRONT INTO OUR NW THURSDAY AFTERNOON. LOWS AND HIGHS
FRIDAY AND SATURDAY WILL ULTIMATELY DEPEND ON THE TIMING OF THE
FRONT... THUS... TRICKY LOW AND HIGH TEMP FORECAST. FOR NOW WILL GO
WITH HIGHS IN THE MID TO UPPER 60S NW TO LOWER TO MID 70S E. EXPECT
LOWS FRIDAY MORNING TO RANGE FROM THE LOWER 50S NW TO AROUND 60
SE... WITH LOWS SATURDAY MORNING EXPECTED TO RANGE FROM THE AROUND
50 NW TO THE UPPER 50S NEAR 60 IN THE EAST. EXPECT LOWS SUNDAY
MORNING TO RANGE FROM THE MID 40 TO AROUND 50. HIGH SUNDAY ARE
EXPECTED TO BE IN THE MID/UPPER 60S TO NEAR 70 IN THE SE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 705 AM MONDAY...
AVIATION CONDITIONS BEGINNING TO DETERIORATE WEST-TO-EAST EARLY THIS
MORNING AS A COLD FRONT APPROACH THE REGION FROM THE WEST. CEILINGS
MAINLY IN THE MVFR CATEGORY OVER THE WESTERN PIEDMONT WITH SHOWER
COVERAGE INCREASING WITH THE PROBABILITY OF IFR CEILINGS IN VICINITY
OF THE HEAVIER SHOWERS. EXPECT CEILINGS TO LOWER INTO THE MVFR
CATEGORY OVER THE REMAINDER OF CENTRAL NC PRIOR TO 10 AM WITH
SHOWERS BECOMING NUMEROUS IN THE AFTERNOON. A FEW STRONG TO SEVERE
STORMS CAN BE EXPECTED THIS AFTERNOON...MAINLY IN THE EASTERN
PIEDMONT...COASTAL PLAIN AND SANDHILLS...WITH WIND GUSTS IN EXCESS
OF 40 KTS PROBABLE.
THE COLD FRONT WILL CROSS CENTRAL NC THIS AFTERNOON THROUGH EARLY
EVENING. THE FRONT SHOULD CROSS THE TRIAD TERMINAL BETWEEN 2 AND 4
PM...KRDU AND KFAY BETWEEN 5 AND 7 PM...AND KRWI BETWEEN 7 AND 9 PM.
THE FRONTAL PASSAGE WILL BE NOTED BY THE SURFACE WINDS VEERING FROM
THE SW TO THE NW. THE SHOWERS SHOULD END AND CEILINGS LIFT INTO THE
VFR CATEGORY WITHIN AN HOUR OF FROPA...AND CLOUDS DISSIPATING WITHIN
A COUPLE HOURS AFTER FROPA.
LATE TONIGHT THROUGH WEDNESDAY...EXPECT VFR CONDITIONS AS HIGH
PRESSURE BUILDS INTO THEN LINGERS OVER THE CAROLINAS. THERE IS THE
POSSIBILITY OF SUB-VFR FOG EARLY THURSDAY MORNING. LATER THURSDAY
INTO FRIDAY...AVIATION CONDITIONS ARE EXPECTED TO DETERIORATE AS
ANOTHER COLD FRONT APPROACHES FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS/BSD
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1052 AM EDT MON OCT 15 2012
.SYNOPSIS...
COLD FRONT EXITS EAST BY LATE MORNING. MUCH COOLER AIR BEHIND IT THIS
AFTERNOON TO SUNDAY. HIGH PRESSURE TUESDAY INTO WEDNESDAY. NEXT
COLD FRONT THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030AM UPDATE...
-SHRA HAVE PRETTY MUCH COME TO AN END ACROSS CWA ATTM...EXCEPT
SOME -SHRA/DZ ACROSS PORTIONS OF SE OH ASSOCIATED WITH COLD POOL
AND S/W TROF APPROACHING. THIS WILL ROTATE THRU AS DAY WEARS ON
WITH JUST ENOUGH LIFT AND MOISTURE FOR SOME MAINLY DIURNALLY
DRIVEN AFTN SCT -SHRA ACROSS SE OH INTO N WV LOWLANDS AND N MTNS.
COULD BE SOME -DZ ACROSS SE OH AND MTNS...BUT ELECTED TO KEEP THIS
OUT OF WX GRIDS FOR NOW. THIS IS WHERE LOW POPS WERE MAINTAINED
WITH UPDATE. OTHERWISE...LOOKING AT CLD FCST TDY. THINK MINI LLVL
DRY SLOT WORKING THRU WV WILL FILL IN OVER NEXT FEW HRS. ANY
SUNSHINE OVER NEXT FEW HRS ACROSS WV LOWLANDS WILL HELP TO PROLONG
WIND GUSTS UP INTO THE 20KT RANGE.
PREVIOUS DISCUSSION BELOW...
LIGHT CONVECTION ASSOCIATED WITH PASSING COLD FRONT ACROSS THE
EASTERN THIRD OF THE AREA BY 430 AM...EXPECTED TO EXIT EASTERN
MOUNTAINS BY 7 AM. SFC OBS INDICATED A WIND SHIFT WITH THIS LINE
OF CONVECTION...HOWEVER...DEWPOINTS GRADIENT REMAINS ACROSS
SOUTHEAST OH. AN UPPER LEVEL TROUGH...WITH DESCENT VORTICITY MAX
WILL PASS OVERHEAD THIS AFTERNOON...AND COULD SQUEEZE SOME OF THE
LINGERING MOISTURE INTO ADDITIONAL LIGHT SHOWERS...AND PUSH THE
ACTUAL FRONT EAST OF THE APPALACHIANS AS WELL. THE SFC LOW
PRESSURE OVER THE GREAT LAKES REGION LIFTS NORTHEAST TODAY...BUT
SOME RAP AROUND MOISTURE AND COLDER TEMPS AT H850 WILL STILL UNDER
THE INFLUENCE OF THE AFOREMENTIONED UPPER TROUGH.
SFC HIGH PRESSURE BUILDS BEHIND THE FRONT BUILDS TONIGHT INTO
TUESDAY TO BRING COLDER TEMPERATURES TONIGHT...GENERALLY INTO THE
UPPER 30S EXTREME NORTHWEST...RANGING INTO THE LOWER 40S HIGHER
ELEVATIONS AS THE FREEZING LINE AT H850 APPROACHES FROM THE
NORTHWEST.
WINDS WILL DECREASE SOME TODAY...TURNING WEST NORTHWEST...WITH FEW
WIND GUSTS OVER THE HIGHER TERRAIN THROUGH THE AFTERNOON HOURS.
WENT WITH A BLEND OF MAV AND MET TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
RISING HEIGHTS WITH NW FLOW ALOFT AND SFC HIGH PRESSURE WILL BE
BUILDING INTO THE AREA TUESDAY AS THE UPPER TROUGH CONTINUES TO MOVE
TO THE NORTHEAST. AFTER SOME LINGERING EARLY MORNING CLOUDS AND
PERHAPS A FEW LIGHT SPRINKLES ACROSS THE NORTHEAST HIGH COUNTRY...A
PLEASANTLY COOL DAY UNDER MOSTLY SUNNY SKIES WILL BE IN STORE FOR
THE FORECAST AREA. INHERITED MAX TEMPS IN THE LOW/MID 60S LOWLANDS
AND AROUND 50F FOR THE HIGHEST LOCALES SUCH AS SNOWSHOE LOOK GOOD.
SFC HIGH PRESSURE WILL BEGIN TO SLIDE OFF TO THE EAST OVERNIGHT TUE
NIGHT/EARLY WED. WITH SOME MODEST WARM ADVECTION NOTED AT 850MB AND
SFC WINDS BACKING FROM THE WEST TO THE SOUTH/SOUTHEAST...DID NUDGE
OVERNIGHT LOWS UP GENERALLY BY A COUPLE OF DEGREES.
BY WEDNESDAY ZONAL FLOW ALOFT TRANSITIONS TO SOUTHWESTERLY BY END OF
DAY WITH THE APPROACH OF THE NEXT UPPER LEVEL TROUGH MOVING SE-WARD
ACROSS THE UPPER MIDWEST. A QUICK MOVING S/W TROUGH IN THE MEAN FLOW
WILL SKIRT ACROSS THE SOUTHERN GREAT LAKES AREA TO THE NORTH WED
MORNING...BUT SHOULD ONLY RESULT IN INCREASED MID-LEVEL CLOUDS
MAINLY DURING THE MORNING HOURS. WARMER TEMPS WILL MOVE INTO THE AREA
AS THE SFC HIGH PRESSURE CONTINUES TO MOVE EAST OF AREA. WITH 850MB
TEMPS OF AROUND 10C-11C PROGGED...INHERITED MAX TEMPS IN THE
MID/UPPER 70S LOWLANDS STILL LOOK GOOD WITH A FEW MINOR TWEAKS.
BY THURSDAY THE UPPER LEVEL LOW ACROSS THE MIDWEST ACROSS THE
WESTERN GREAT LAKES WHILE ITS ATTENDANT SFC LOW DEEPENS AND
PINWHEELS AROUND IT PUSHING NORTHWARD ROUGHLY AROUND LAKE SUPERIOR
OR NORTH. CONSIDERABLE DIFFERENCES WITH THE TIMING AND LOCATION OF
UPPER LOW AND SFC FRONT STILL EXIST...WITH THE NAM/EC SLOWER AND GFS
AND OTHERS AMONG THE FASTER SOLUTIONS. THERE APPEARS TO BE DECENT
ENSEMBLE SUPPORT WITH THE SLOWER SOLN/S AND WILL LEAN THE FORECAST
IN THIS DIRECTION...BRINGING POPS INTO THE NW ZONES BY 12Z THU WITH
HIGHER POPS LATER THURSDAY. STILL...WITH THE UNCERTAINTIES WILL CAP
POPS ONLY AT HIGH CHANCE. DID ELECT TO NUDGE MAX TEMPS DOWN SLIGHTLY
WITH 850MB TEMP GUIDANCE DEPICTING THU PM TEMPS OF AROUND 6C-7C.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
OVERALL UNSETTLED WEATHER PATTERN IN THE LONG TERM...WITH MODELS
STARTING TO COME INTO BETTER AGREEMENT THAN IN PREVIOUS RUNS. PERIOD
STARTS OUT WITH AN UPPER TROUGH DEEPENING OVER THE MIDWEST...AND
EVENTUALLY SWINGING A COLD FRONT THROUGH THE AREA EITHER THURSDAY OR
FRIDAY. THIS WILL BRING AN INCREASE IN SHOWER...AND ISOLD
THUNDERSTORM ACTIVITY...AS WELL AS WARMING TEMPERATURES OUT AHEAD OF
THE FRONT. AFTER FRONT EXITS TO THE EAST...UPPER LEVEL LOW WILL
DEEPEN ACROSS THE U.S...AND AFFECT THE AREA OVER THE NEXT SEVERAL
DAYS. ECMWF IS STARTING TO COME INTO LINE A BIT BETTER WITH THE
GFS...WITH LOW DEEPENING ACROSS THE UPPER MIDWEST...KEEPING THE AREA
IN A WARM SOUTHWESTERLY FLOW...UNTIL IT FINALLY KICKS OFF TO THE
EAST LATE IN THE WEEK. ECMWF IS STILL A LITTLE DEEPER WITH THIS
TROUGH ACROSS THE U.S. THAN THE GFS...BUT OVERALL...MODELS STARTING
TO COME INTO AGREEMENT.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
IFR CLOUD DECK AROUND 1500 FEET WILL AFFECT THE MOUNTAINS SITES
THIS MORNING...AS A COLD FRONT PUSHES EAST BY 15Z. ALTHOUGH THERE
HAS BEEN A WIND SHIFT FROM SOUTHWEST TO WEST NORTHWEST IN THE
LOWER LEVELS....DEWPOINTS GRADIENT CONTINUES ACROSS SOUTHEAST OH
SUGGESTING THE ELUSIVE COLD FRONT MAY STAY CLOSE TO THE OH RIVER
BY 11Z. MODELS CONTINUE TO SHOW LOW LEVEL FLOW TURNING MORE
NORTHWEST BRINGING COLDER AND DRIER AIR...TO SQUEEZE ANY MOISTURE
IN A FORM OF LOW CLOUDS OR FEW SPRINKLES OUT THIS AFTERNOON...AS A
VORTICITY MAX ASSOCIATED WITH AT HIGH AMPLITUDE H5 TROUGH SWEEPS
THE AREA THIS AFTERNOON.
THEREFORE...EXPECT MVFR CEILINGS UNDER AREAS OF RAIN MAINLY
ACROSS THE NORTHERN SITES...AND PERHAPS NORTHEAST MOUNTAINS THROUGH
THIS AFTERNOON.
HIGH PRESSURE BUILDS OVERHEAD...TAKING CONTROL EARLY TUESDAY AND
WEDNESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: DURATION OF LOW LEVEL DECK AROUND 1500 FEET
OVER THE MOUNTAINS AND NORTHERN SECTIONS COULD VARY. TIMING ON
TRANSITIONS TO/FROM MVFR COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H M M M H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H M M M H M H H H
EKN CONSISTENCY H H H M M M M M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H M M H H H H H
AFTER 12Z TUESDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ/30
SHORT TERM...50
LONG TERM...SL
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
642 AM EDT MON OCT 15 2012
.SYNOPSIS...
COLD FRONT EXITS EAST BY LATE MORNING. MUCH COOLER AIR BEHIND IT THIS
AFTERNOON TO SUNDAY. HIGH PRESSURE TUESDAY INTO WEDNESDAY. NEXT
COLD FRONT THURSDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LIGHT CONVECTION ASSOCIATED WITH PASSING COLD FRONT ACROSS THE
EASTERN THIRD OF THE AREA BY 430 AM...EXPECTED TO EXIT EASTERN
MOUNTAINS BY 7 AM. SFC OBS INDICATED A WIND SHIFT WITH THIS LINE
OF CONVECTION...HOWEVER...DEWPOINTS GRADIENT REMAINS ACROSS
SOUTHEAST OH. AN UPPER LEVEL TROUGH...WITH DESCENT VORTICITY MAX
WILL PASS OVERHEAD THIS AFTERNOON...AND COULD SQUEEZE SOME OF THE
LINGERING MOISTURE INTO ADDITIONAL LIGHT SHOWERS...AND PUSH THE
ACTUAL FRONT EAST OF THE APPALACHIANS AS WELL. THE SFC LOW
PRESSURE OVER THE GREAT LAKES REGION LIFTS NORTHEAST TODAY...BUT
SOME RAP AROUND MOISTURE AND COLDER TEMPS AT H850 WILL STILL UNDER
THE INFLUENCE OF THE AFOREMENTIONED UPPER TROUGH.
SFC HIGH PRESSURE BUILDS BEHIND THE FRONT BUILDS TONIGHT INTO
TUESDAY TO BRING COLDER TEMPERATURES TONIGHT...GENERALLY INTO THE
UPPER 30S EXTREME NORTHWEST...RANGING INTO THE LOWER 40S HIGHER
ELEVATIONS AS THE FREEZING LINE AT H850 APPROACHES FROM THE
NORTHWEST.
WINDS WILL DECREASE SOME TODAY...TURNING WEST NORTHWEST...WITH FEW
WIND GUSTS OVER THE HIGHER TERRAIN THROUGH THE AFTERNOON HOURS.
WENT WITH A BLEND OF MAV AND MET TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
RISING HEIGHTS WITH NW FLOW ALOFT AND SFC HIGH PRESSURE WILL BE
BUILDING INTO THE AREA TUESDAY AS THE UPPER TROUGH CONTINUES TO MOVE
TO THE NORTHEAST. AFTER SOME LINGERING EARLY MORNING CLOUDS AND
PERHAPS A FEW LIGHT SPRINKLES ACROSS THE NORTHEAST HIGH COUNTRY...A
PLEASANTLY COOL DAY UNDER MOSTLY SUNNY SKIES WILL BE IN STORE FOR
THE FORECAST AREA. INHERITED MAX TEMPS IN THE LOW/MID 60S LOWLANDS
AND AROUND 50F FOR THE HIGHEST LOCALES SUCH AS SNOWSHOE LOOK GOOD.
SFC HIGH PRESSURE WILL BEGIN TO SLIDE OFF TO THE EAST OVERNIGHT TUE
NIGHT/EARLY WED. WITH SOME MODEST WARM ADVECTION NOTED AT 850MB AND
SFC WINDS BACKING FROM THE WEST TO THE SOUTH/SOUTHEAST...DID NUDGE
OVERNIGHT LOWS UP GENERALLY BY A COUPLE OF DEGREES.
BY WEDNESDAY ZONAL FLOW ALOFT TRANSITIONS TO SOUTHWESTERLY BY END OF
DAY WITH THE APPROACH OF THE NEXT UPPER LEVEL TROUGH MOVING SE-WARD
ACROSS THE UPPER MIDWEST. A QUICK MOVING S/W TROUGH IN THE MEAN FLOW
WILL SKIRT ACROSS THE SOUTHERN GREAT LAKES AREA TO THE NORTH WED
MORNING...BUT SHOULD ONLY RESULT IN INCREASED MID-LEVEL CLOUDS
MAINLY DURING THE MORNING HOURS. WARMER TEMPS WILL MOVE INTO THE AREA
AS THE SFC HIGH PRESSURE CONTINUES TO MOVE EAST OF AREA. WITH 850MB
TEMPS OF AROUND 10C-11C PROGGED...INHERITED MAX TEMPS IN THE
MID/UPPER 70S LOWLANDS STILL LOOK GOOD WITH A FEW MINOR TWEAKS.
BY THURSDAY THE UPPER LEVEL LOW ACROSS THE MIDWEST ACROSS THE
WESTERN GREAT LAKES WHILE ITS ATTENDANT SFC LOW DEEPENS AND
PINWHEELS AROUND IT PUSHING NORTHWARD ROUGHLY AROUND LAKE SUPERIOR
OR NORTH. CONSIDERABLE DIFFERENCES WITH THE TIMING AND LOCATION OF
UPPER LOW AND SFC FRONT STILL EXIST...WITH THE NAM/EC SLOWER AND GFS
AND OTHERS AMONG THE FASTER SOLUTIONS. THERE APPEARS TO BE DECENT
ENSEMBLE SUPPORT WITH THE SLOWER SOLN/S AND WILL LEAN THE FORECAST
IN THIS DIRECTION...BRINGING POPS INTO THE NW ZONES BY 12Z THU WITH
HIGHER POPS LATER THURSDAY. STILL...WITH THE UNCERTAINTIES WILL CAP
POPS ONLY AT HIGH CHANCE. DID ELECT TO NUDGE MAX TEMPS DOWN SLIGHTLY
WITH 850MB TEMP GUIDANCE DEPICTING THU PM TEMPS OF AROUND 6C-7C.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
OVERALL UNSETTLED WEATHER PATTERN IN THE LONG TERM...WITH MODELS
STARTING TO COME INTO BETTER AGREEMENT THAN IN PREVIOUS RUNS. PERIOD
STARTS OUT WITH AN UPPER TROUGH DEEPENING OVER THE MIDWEST...AND
EVENTUALLY SWINGING A COLD FRONT THROUGH THE AREA EITHER THURSDAY OR
FRIDAY. THIS WILL BRING AN INCREASE IN SHOWER...AND ISOLD
THUNDERSTORM ACTIVITY...AS WELL AS WARMING TEMPERATURES OUT AHEAD OF
THE FRONT. AFTER FRONT EXITS TO THE EAST...UPPER LEVEL LOW WILL
DEEPEN ACROSS THE U.S...AND AFFECT THE AREA OVER THE NEXT SEVERAL
DAYS. ECMWF IS STARTING TO COME INTO LINE A BIT BETTER WITH THE
GFS...WITH LOW DEEPENING ACROSS THE UPPER MIDWEST...KEEPING THE AREA
IN A WARM SOUTHWESTERLY FLOW...UNTIL IT FINALLY KICKS OFF TO THE
EAST LATE IN THE WEEK. ECMWF IS STILL A LITTLE DEEPER WITH THIS
TROUGH ACROSS THE U.S. THAN THE GFS...BUT OVERALL...MODELS STARTING
TO COME INTO AGREEMENT.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
IFR CLOUD DECK AROUND 1500 FEET WILL AFFECT THE MOUNTAINS SITES
THIS MORNING...AS A COLD FRONT PUSHES EAST BY 15Z. ALTHOUGH THERE
HAS BEEN A WIND SHIFT FROM SOUTHWEST TO WEST NORTHWEST IN THE
LOWER LEVELS....DEWPOINTS GRADIENT CONTINUES ACROSS SOUTHEAST OH
SUGGESTING THE ELUSIVE COLD FRONT MAY STAY CLOSE TO THE OH RIVER
BY 11Z. MODELS CONTINUE TO SHOW LOW LEVEL FLOW TURNING MORE
NORTHWEST BRINGING COLDER AND DRIER AIR...TO SQUEEZE ANY MOISTURE
IN A FORM OF LOW CLOUDS OR FEW SPRINKLES OUT THIS AFTERNOON...AS A
VORTICITY MAX ASSOCIATED WITH AT HIGH AMPLITUDE H5 TROUGH SWEEPS
THE AREA THIS AFTERNOON.
THEREFORE...EXPECT MVFR CEILINGS UNDER AREAS OF RAIN MAINLY
ACROSS THE NORTHERN SITES...AND PERHAPS NORTHEAST MOUNTAINS THROUGH
THIS AFTERNOON.
HIGH PRESSURE BUILDS OVERHEAD...TAKING CONTROL EARLY TUESDAY AND
WEDNESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: DURATION OF LOW LEVEL DECK AROUND 1500 FEET
OVER THE MOUNTAINS AND NORTHERN SECTIONS COULD VARY. TIMING ON
TRANSITIONS TO/FROM MVFR COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY M M M M M M M M M H H H
HTS CONSISTENCY M M M M H M M H H H H H
BKW CONSISTENCY H M M H M M M M M M H M
EKN CONSISTENCY M H H M H M M M M M M M
PKB CONSISTENCY H H M H H H M H H H H H
CKB CONSISTENCY M M M H M M M M M M H H
AFTER 12Z TUESDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...SL
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
556 AM CDT MON OCT 15 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
227 AM CDT MON OCT 15 2012
MAIN FORECAST CONCERN IS THE IMPACTS ON THE AREA FROM A DEEP UPPER
TROUGH DROPPING INTO THE NORTHERN PLAINS TUESDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED NEARLY ZONAL FLOW ACROSS THE NORTHERN ROCKIES AND
SOUTHWEST CANADA...AND TROUGHING ACROSS THE WESTERN GREAT LAKES
REGION INTO ILLINOIS. THE FORECAST AREA LIES ON THE WESTERN SIDE
OF THIS TROUGHING...FAVORING SUBSIDENCE AND DRY AIR. 00Z SOUNDINGS
FROM ABR AND MPX REFLECT THESE ATTRIBUTES...WITH PRECIPITABLE
WATER VALUES NEAR 0.5 INCH. SATELLITE IMAGERY ALSO REFLECTS THE
DRY AIR WITH CLEARING ACROSS MUCH OF MINNESOTA AND IOWA. SOME
COOLER AIR TOO FLOWING IN ON THE BACK SIDE OF THE TROUGH WITH
850MB TEMPS OF 3C AT MPX AT 00Z. HOWEVER...WARMER READINGS OF
7-15C AT 850MB WERE OBSERVED IN THE DAKOTAS. AT THE SURFACE...A
RIDGE OF HIGH PRESSURE WAS PRESENT ACROSS WESTERN MINNESOTA WHILE
A NEW LOW PRESSURE SYSTEM WAS TAKING SHAPE ACROSS SOUTHERN
SASKATCHEWAN.
TODAY AND TONIGHT...FOCUS IS ON A COLLECTION OF SHORTWAVES IN THE
ZONAL FLOW OVER WASHINGTON. MODELS ARE IN GOOD AGREEMENT SENDING
THESE EAST INTO THE EASTERN DAKOTAS AND WESTERN MINNESOTA BY 12Z
TUESDAY. THERE EVEN APPEARS TO BE A WEAK TROUGH SIGNATURE IN THE
500MB HEIGHT FIELD AT 12Z WITH THESE SHORTWAVES. AS THESE SHORTWAVES
HEAD EAST...THEY WILL HELP PICK UP THE CURRENT SYSTEM IN SOUTH
CENTRAL SASKATCHEWAN...SENDING A TROUGH INTO MINNESOTA BY 12Z
TUESDAY. WARM ADVECTION AHEAD OF THIS SYSTEM WILL COMMENCE OVER THE
FORECAST AREA THIS AFTERNOON...WITH 850MB TEMPS TOPPING OUT BETWEEN
4-8C BY 00Z...WARMEST WEST. OTHER THAN SOME INCREASE IN WARM
ADVECTION HIGH AND PERHAPS MID CLOUDS AS WELL LATE IN THE DAY...
CURRENTLY OBSERVED CROSSING THE DAKOTAS...SHOULD SEE PLENTY OF SUN.
AS A RESULT...ANTICIPATING TEMPERATURES TO TOP OUT IN THE MID 50S TO
MID 60S. FOR TONIGHT...PLANNING ON THE MID AND HIGH CLOUDS TO
QUICKLY ENCOMPASS THE AREA...HELPING TO LIMIT TEMPERATURE FALL. IN
ADDITION...MODELS SHOW AN INCREASE OF 850MB MOISTURE TRANSPORT
THROUGH THE NIGHT AHEAD OF THE TROUGH COMING INTO MINNESOTA. NOSE OF
THIS MOISTURE TRANSPORT...AS WELL AS THE BULK OF ISENTROPIC LIFT...
APPEARS TO BE SITUATED MAINLY NORTH OF THE AREA. AS SUCH...EXPECTING
MOST PRECIPITATION TO STAY NORTH. HOWEVER...DID INTRODUCE A 20
PERCENT CHANCE IN TAYLOR COUNTY SINCE THEY LOOK TO BE RIGHT ON THE
EDGE OF WHERE THE WARM ADVECTION PRECIPITATION MAY EXIST. FOLLOWED A
BLEND OF GUIDANCE FOR LOWS.
TUESDAY...THE WEAK UPPER TROUGH SIGNATURE PRESENT OVER THE
EASTERN DAKOTAS AT 12Z TUESDAY IS FORECAST BY ALL MODELS TO CROSS
THE AREA ON TUESDAY. THE SAME QUESTIONS REMAIN IF THIS TROUGH CAN
PRODUCE PRECIPITATION AS IT MOVES THROUGH. THE 14.12Z ECMWF WAS MUCH
MORE IMPRESSIVE WITH QPF COMPARED TO ITS PREVIOUS RUN WITH MUCH OF
THE AREA AFFECTED. MEANWHILE THE 15.00Z NAM CONTINUES TO PAINT A
MOSTLY DRY SCENARIO OUTSIDE OF SOME LINGERING WARM ADVECTION PRECIP
OVER TAYLOR COUNTY IN THE MORNING. THE 15.00Z GFS LIES IN-BETWEEN
THE TWO SCENARIOS WITH QPF MAINLY IN THE MORNING ALONG AND NORTHEAST
OF I-94. THINKING THE ECMWF IS OVERDONE WITH THE AMOUNT OF QPF GIVEN
THE OVERALL LACK OF MOISTURE AVAILABILITY...ESPECIALLY IN THE LOWER
LEVELS. THEREFORE...HAVE STAYED CLOSE TO THE PREVIOUS FORECAST OF
20-30 PERCENT CHANCES ALONG AND NORTHEAST OF I-94. NEW 15.00Z ECMWF
HAS A LITTLE LESS QPF...AND FOCUSES ITS MAIN AREA SIMILAR TO WHERE
THE FORECAST HAS IT. TEMPERATURES ARE A BIT TRICKY ON TUESDAY AS
MUCH OF THE MORNING WILL LIKELY BE CLOUDY WITH MID AND HIGH CLOUDS
AROUND. AS THE TROUGH COMES THROUGH...THE OPPORTUNITY FOR CLEARING
EXISTS. 850MB TEMPS REALLY DO NOT COOL WITH THE TROUGH...HOVERING
BETWEEN 9C NORTH AND 13C SOUTH. HERE TOO WILL STAY PRETTY CLOSE TO
THE PREVIOUS FORECAST WITH HIGHS FROM THE MID 60S EAST (MOST CLOUDS)
TO LOW 70S WEST.
TUESDAY NIGHT...A VERY POTENT UPPER TROUGH IS PROGGED TO DIG DOWN
INTO MONTANA AND THE NORTHERN PLAINS BY 12Z WEDNESDAY. AS THIS
TROUGH DIGS IN...A COLD FRONT GETS SENT EASTWARD...PERHAPS REACHING
WESTERN PORTIONS OF THE FORECAST AREA BY 12Z WEDNESDAY. THE 15.00Z
GFS AND NAM...AS WELL AS THE 14.12Z/15.00Z ECMWF KEEP PRECIPITATION
NORTHWEST OF THE AREA THROUGH TUESDAY NIGHT. THIS SEEMS REASONABLE
GIVEN THAT THE BULK OF THE PRECIPITATION LOOKS TO OCCUR POST-FRONTAL
AND MORE ASSOCIATED WITH DPVA FROM THE POTENT TROUGH. AS SUCH...HAVE
REMOVED ANY LOW CHANCES OF PRECIPITATION IN FAR WESTERN PORTIONS OF
THE AREA. TEMPERATURES COULD DROP QUICKLY IN THE EVENING...
ESPECIALLY AT THE TYPICAL COLD SPOTS...WITH MOSTLY CLEAR SKIES AND A
BAGGY PRESSURE GRADIENT IN PLACE. INCREASING MID AND HIGH CLOUDS AS
WELL AS WINDS AHEAD OF THE FRONT AND UPPER TROUGH SHOULD HELP TO
HOLD TEMPERATURES STEADY OR EVEN RISE AFTER MIDNIGHT.
WEDNESDAY AND WEDNESDAY NIGHT...MODELS ARE IN REALLY GOOD AGREEMENT
THAT THE POTENT UPPER TROUGH WILL CONTINUE TO DIG SOUTHEASTWARD...
FULLY ENCOMPASSING THE AREA BY WEDNESDAY NIGHT. HOWEVER...THERE ARE
SOME IMPORTANT DETAILS WITHIN THE UPPER TROUGH THAT MODELS DIFFER
ON. THE FIRST IS WITH A SHORTWAVE EXTENDING SOUTH OF AN UPPER LOW
CONTAINED WITHIN THE TROUGH. THIS SHORTWAVE...PROGGED NEAR BISMARCK
NORTH DAKOTA AT 12Z WEDNESDAY...THE 15.00Z GFS IS MUCH FASTER THAN
ANY OTHER MODEL WITH IT BY BRINGING IT INTO THE FORECAST AREA BY
00Z. THE 15.00Z NAM/UKMET/CANADIAN/ECMWF ARE ALL SLOWER...ONLY
REACHING WESTERN MINNESOTA BY 00Z. THIS IS A SIGNIFICANT ISSUE AS
THE FASTER GFS WOULD NOT ALLOW AS MUCH MOISTURE RETURN FROM THE GULF
OF MEXICO TO COME UP INTO THE FORECAST AREA. THUS...THE GFS ENDS UP
AS A DRY SOLUTION. ALL THE OTHER MODELS PRODUCE PRECIPITATION ON
WEDNESDAY WHICH SEEMS REASONABLE. THUS...THE 60 PERCENT CHANCES ARE
STILL ON TRACK. WEDNESDAY NIGHT IS A LITTLE MORE UP IN THE AIR...
THOUGH. THINGS IN PLAY WITH PRECIPITATION CHANCES INCLUDE: TRACK OF
THE UPPER LOW WITHIN THE TROUGH...A POSSIBLE DRY SLOT...AND A TROWAL
AND COLD CONVEYOR BELT AREA WRAPPING AROUND THE UPPER LOW. THE
PMDHMD FROM HPC DISCUSSES THIS SITUATION WELL...WITH MODELS ALL OVER
THE PLACE WITH THESE FEATURES AND ALL PLAUSIBLE. THEREFORE...PLAN ON
TAKING A CONSENSUS APPROACH. AS THE PMDHMD STATES TOO...THE SYSTEM
RESPONSIBLE FOR THE POTENT UPPER TROUGH IS IN A DATA SPARSE REGION
OF THE NORTHERN/NORTHEAST PACIFIC. SO IT MAY TAKE AWHILE BEFORE
MODELS SETTLE DOWN ON A SOLUTION WITH THE VARIOUS FEATURES. THE
CONSENSUS APPROACH RESULTS IN 30 TO 50 PERCENT CHANCES...HIGHEST
ACROSS THE NORTH. ALSO FOLLOWED THE CONSENSUS APPROACH FOR
TEMPERATURES. SHOULD STILL BE NEAR NORMAL ON WEDNESDAY WITH THE WARM
ADVECTION AHEAD OF A SURFACE COLD FRONTAL PASSAGE. HOWEVER...
TEMPERATURES LOOK TO FALL IN THE AFTERNOON AS THE FRONT PASSES AND
RAIN DEVELOPS. IF A DEEP DRY SLOT ENTERS THE PICTURE WEDNESDAY
NIGHT...LOWS COULD BOTTOM OUT IN 30S. HOWEVER...WILL PLAY MORE
CLOUDS AND WIND TO KEEP LOWS IN THE 40S.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
227 AM CDT MON OCT 15 2012
15.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN FAIRLY GOOD
AGREEMENT ON HANDLING THE UPPER TROUGH AND ITS LIFT OUT NORTHEAST
AWAY FROM THE AREA. THE GFS AGAIN IS SLIGHTLY FAST...BUT ALL MODELS
AGREE THAT BY FRIDAY NIGHT...THE UPPER TROUGH WILL BE FAR ENOUGH
EAST OF THE AREA TO ALLOW CONDITIONS TO DRY OUT. UNTIL THEN...SAME
CONCERNS THAT WERE PRESENT ON WEDNESDAY NIGHT WITH POSITIONS OF THE
UPPER LOW IN THE TROUGH...DRY SLOT...TROWAL AND COLD CONVEYOR BELT
STILL PERSIST THROUGH FRIDAY. AS A RESULT...HAVE CONTINUED TO FOLLOW
A CONSENSUS APPROACH. HIGHEST CHANCES OF PRECIPITATION EXPECTED ON
THURSDAY SINCE THERE ARE INDICATIONS THAT THE TROUGH WILL FILL AFTER
THEN. COOL CONDITIONS ARE LIKELY TOO WITH THE UPPER TROUGH IN PLACE.
850MB TEMPS ARE ONLY PROGGED IN THE 0-2C RANGE. COMBINE THIS WITH
PRECIPITATION COULD END UP KEEPING HIGHS IN SOME LOCATIONS FROM EVEN
REACHING 50...ESPECIALLY ON THURSDAY.
FOR THE WEEKEND...MODELS ARE INDICATING THAT A POTENT UPPER TROUGH
WILL DROP SOUTH OUT OF THE GULF OF ALASKA AND AT LEAST INTO BRITISH
COLUMBIA. THE 14.12Z AND 15.00Z ECMWF RUNS AS WELL AS SOME OF THE
GFS ENSEMBLES TAKE IT ONE STEP FURTHER AND DIG THE TROUGH INTO THE
PACIFIC NORTHWEST. ALL SOLUTIONS THUS WOULD YIELD AT LEAST ZONAL
FLOW DOWNSTREAM INTO THE FORECAST AREA...RESULTING IN WARMING AND
DRY CONDITIONS. IN THE CASE OF THE ECMWF...RIDGING ENDS UP BUILDING
INTO THE FORECAST AREA. FOR NOW HAVE FOLLOWED THE CONSENSUS APPROACH
FOR TEMPERATURES GIVEN THE SPREAD IN HOW THE UPPER FLOW EVOLVES...
BUT SHOULD THE ECMWF VERIFY...TEMPERATURES MAY NEED TO BE INCREASED.
BY 18Z SUNDAY...THE ECMWF SUGGESTS 850MB TEMPS OF 10-14C...COMPARED
TO 4-8C FROM THE GFS.
&&
.AVIATION...TODAY AND TONIGHT
556 AM CDT MON OCT 15 2012
MVFR CONDITIONS AT KLSE IN SHALLOW FOG WILL RAPIDLY IMPROVE THIS
MORNING AFTER SUNRISE. OTHERWISE PLAN ON VFR CONDITIONS AT KLSE AND
KRST THROUGH THIS EVENING AS HIGH PRESSURE MOVES OVER THE UPPER
MISSISSIPPI RIVER VALLEY. WINDS WILL BE LIGHT OUT OF THE THE
WEST/NORTHWEST...GRADUALLY SWITCHING TO THE SOUTHWEST LATE THIS
AFTERNOON AS THE HIGH MOVES EAST OF THE REGION. A TROUGH OF LOW
PRESSURE WILL MOVE INTO THE AREA TONIGHT WITH CLOUDS INCREASING
AT THE TAF SITES. LOOK FOR CEILINGS TO LOWER INTO THE 9 TO 12 KFT
RANGE OVERNIGHT. WINDS WILL INCREASE OUT OF THE SOUTH TONIGHT INTO
THE 9 TO 15 KT RANGE. WILL HAVE TO KEEP A CLOSE WATCH ON THE
POTENTIAL FOR LOW LEVEL WIND SHEAR. FORECAST SOUNDINGS ARE SHOWING
WINDS INCREASING TO AROUND 45 KTS AT 2000FT. IT APPEARS SURFACE
WINDS WILL STAY UP JUST ENOUGH FOR KRST TO FALL SHORT OF LLWS
CRITERIA. SURFACE WINDS WILL BE LESS AT KLSE...AROUND 9KTS. THERE
IS UNCERTAINTY REGARDING HOW MUCH DECOUPLING WILL OCCUR TONIGHT SO
HAVE DECIDED NOT INCLUDE LOW LEVEL WIND SHEAR IN THE TAFS AT THIS
TIME. SPRINKLES ARE POSSIBLE AT THE TAF SITES TUESDAY MORNING AS
THE TROUGH MOVES IN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CDT MON OCT 15 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS MIAMI FL
332 PM EDT MON OCT 15 2012
.SHORT TERM (TONIGHT-WEDNESDAY NIGHT)...
THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTHWEST FROM THE CAROLINAS TO THE NORTHERN GULF OF MEXICO WITH
PLENTY OF DRY AIR OVERSPREADING THE REGION IN ITS WAKE. OUT AHEAD OF
THIS BOUNDARY OVER OUR AREA...MOISTURE AND DEWPOINTS HAVE INCREASED
OVER THE PAST DAY. THIS INCREASE IN MOISTURE (MOSTLY LOW LEVEL)
COMBINED WITH DIURNAL HEATING AND LOCAL SEA BREEZES HAVE ALREADY
BEEN ENOUGH TO TRIGGER SCATTERED SHOWERS EARLIER THIS AFTERNOON
ACROSS THE WESTERN HALF OF THE SRN FL PENINSULA. THE LATEST HRRR AND
WRF MODEL REFLECTIVITIES SHOW SIMILAR RESULTS AND INDICATE MAINLY
ISOLATED TO SCATTERED AFTERNOON COVERAGE FAVORING THE INLAND AND
WEST GULF COAST CONTINUING THROUGH THE EVENING HOURS WITH MAINLY
ISOLATED THUNDERSTORMS.
TUESDAY THROUGH THE MID WEEK...A FAIRLY PROGRESSIVE UPPER PATTERN IS
EXPECTED ACROSS THE REGION CHARACTERIZED BY A SERIES OF SHORTWAVE
TROUGHS TRANSLATING EWD. THE FIRST OF WHICH IS FORECAST TO PASS OVER
THE STATE EARLY TUESDAY MORNING USHERING IN ANOTHER SURGE OF DRIER
AIR THAT WILL SPREAD INTO THE LOCAL AREA FROM NORTH TO SOUTH THROUGH
THE COURSE OF THE DAY TUESDAY ALONG WITH THE PREVIOUSLY MENTIONED
COLD FRONT AS IT CONTINUES SOUTH INTO THE AREA AND BEGINS TO
DIMINISH. DEWPOINTS ARE FORECAST TO BRIEFLY DIP BACK INTO THE MID TO
UPPER 60S THROUGH THIS TIME...MAINLY INLAND. THEREFORE...MAINLY
ISOLATED SHOWERS WILL BE POSSIBLE WITHIN THE NORTHEAST FLOW OFF THE
ATL WATERS ACROSS THE EAST AND SRN AREAS TOMORROW AFTN/EVENING. ON
WEDNESDAY...MODELS INDICATE ANOTHER SHORTWAVE TROUGH TRANSLATING EWD
ACROSS THE REGION WITH INCREASING DEEP LAYER MOISTURE. WESTERLY FLOW
THAT IS FORECAST...SHOULD RESULT IN THE BULK OF THE ACTIVITY AND
COVERAGE TO SETUP OVER THE INTERIOR AND EAST COAST SECTIONS OF THE
LOCAL AREA THROUGH THIS TIME. THEREFORE...WILL BRING BACK THE CHANCE
FOR SHOWER/TSTMS LATER WEDNESDAY INTO WEDNESDAY NIGHT AHEAD OF THIS
UPPER FEATURE.
MIAMI BEACH COASTAL FLOODING CONCERNS....EARLIER THIS
MORNING...THERE WERE REPORTS OF SOME MINOR STREET FLOODING IN THE
SOUTH BEACH AREA ALONG PURDY AVE/20TH STREET DURING THE HIGH TIDE
CYCLE (AS WELL AS A FEW OTHER STREETS IN THE SAME GENERAL AREA).
THIS WAS MOSTLY CONTRIBUTED TO THE WATER LEVELS RUNNING SLIGHTLY
ABOVE NORMAL DUE TO THE COMBINATION OF SPRING TIDES AND THE
INFLUENCE OF THE STRONG ONSHORE WINDS AND ELEVATED SEAS OBSERVED
OVER THE WEEKEND. EXPECT THIS POTENTIAL TO CONTINUE AT EACH HIGH
TIDE CYCLE THIS EVENING AND AGAIN TUESDAY MORNING JUST AFTER
DAYBREAK BEFORE DECREASING THROUGH THE MID-WEEK PERIOD. ALTHOUGH THE
THREAT IS LOW...ANY ADDITIONAL RAINFALL THAT BECOMES CONCENTRATED
OVER THESE AREAS COULD RESULT IN ADDITIONAL FLOODING OR STANDING
WATER CONCERNS THROUGH THIS TIME. THE NEXT HIGH TIDE CYCLE WILL COME
LATER THIS EVENING BETWEEN 8 AND 9 PM AND AGAIN TOMORROW MORNING
AROUND THE MID-MORNING TIME FRAME.
.LONG TERM (THURSDAY-WEEKEND)...
FOR LATE WEEK INTO NEXT WEEKEND, BOTH GFS/ECMWF SHOW A STRONG CLOSED
MID/UPPER LOW DIVING ACROSS THE GREAT LAKES STATES WITH A TROUGH
EXTENDING SOUTH INTO THE GULF OF MEXICO. BOTH MODELS SHOW WARM,
HUMID CONDITIONS LATE WEEK AHEAD OF THIS SYSTEM AND JUST CANNOT
SHUT MENTION OF SHOWERS/TSTORMS OFF ANY DAY DUE TO SUFFICIENT
MOISTURE/INSTABILITY CONTINUING...ESPECIALLY OVER THE WEEKEND.
BOTH MODELS HAVE BEEN GRADUALLY BACKING OFF ON THE THRUST OF THIS
COLD FRONT FOR SOUTH FLORIDA...ESPECIALLY NOW THE GFS WHICH KEEPS
DEWPOINTS IN THE LOWER 70S ALL THE WAY THROUGH NEXT WEEKEND AND
INTO NEXT WEEK. THE ECMWF SHOWS SLIGHTLY DRIER AIR BEHIND THE
BOUNDARY BY MONDAY...BUT EVEN IT SHOWS WINDS QUICKLY TO THE EAST
BEHIND IT. SO THE BOTTOM LINE IS WARM, HUMID CONDITIONS LOOK TO
PREVAIL THROUGH THE FORECAST PERIOD ALONG WITH DAILY CHANCES OF
SHOWERS/TSTORMS.
&&
.MARINE...
WINDS AND SEAS WILL CONTINUE TO SUBSIDE OVER THE MARINE AREA THROUGH
THE MID WEEK AS A WEAKENING COLD FRONT APPROACHES AND MOVES INTO THE
AREA FROM THE NORTH. AN EASTERLY SWELL WILL BEGIN TO OVERSPREAD THE
ATLANTIC WATERS THROUGH THE DAY TUESDAY AND CONTINUE THROUGH THE MID
WEEK PERIOD BEFORE SUBSIDING. OUTSIDE OF THE SWELL ENERGY THAT
PROGRESSES THROUGH THE PROVIDENCE CHANNEL AND SPREADS OVER THE
MARINE AREAS...MOST OF THIS ACTIVITY WILL IMPACT THE FLORIDA EAST
COAST NORTH OF JUPITER INLET THROUGH THIS TIME. ISOLATED TO
SCATTERED SHOWERS WILL REMAIN POSSIBLE EACH DAY THROUGH THE PERIOD.
&&
.FIRE WEATHER...
RELATIVE HUMIDITIES ARE FORECAST TO REMAIN WELL ABOVE CRITICAL
LEVELS WITH NO RED FLAG CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 88 72 86 / 10 20 20 40
FORT LAUDERDALE 74 87 74 85 / 10 20 20 40
MIAMI 75 87 73 87 / 10 20 20 40
NAPLES 73 87 71 84 / 20 10 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...55/CWC
LONG TERM...DG
AREA FORECAST DISCUSSION
NWS MIAMI FL
132 PM EDT MON OCT 15 2012
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD.
SLIGHTLY DRIER AIR WILL MOVE INTO THE REGION THIS AFTERNOON,
HOWEVER WE WILL KEEP THE VCSH IN ACROSS ALL TERMINALS. THERE COULD
BE A FEW THUNDERSTORMS ACROSS INTERIOR SECTIONS, HOWEVER THEY
SHOULD BE FAR ENOUGH AWAY FROM THE TERMINALS. WINDS WILL REMAIN
OUT OF THE NORTHEAST THIS AFTERNOON ACROSS THE EAST COAST
TERMINALS. AT KAPF A GULF SEA BREEZE WILL DEVELOP THIS AFTERNOON
ALLOWING THE WINDS TO SHIFT TO THE WEST NORTHWEST. THESE WINDS
WILL SHIFT BACK TO THE NORTHEAST THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 1135 AM EDT MON OCT 15 2012/
UPDATE...
OUTSIDE OF A FEW MINOR UPDATES WITHIN THE GRIDDED FORECAST
DATABASE BASED ON THE LATEST OBSERVATIONS AND RADAR TRENDS...THE
PREVIOUS FORECAST REMAINS ON TRACK. THE FOG THAT OCCURRED THIS
MORNING ACROSS WESTERN COLLIER COUNTY HAS LIFTED OR BURNED OFF.
THE LATEST SURFACE ANALYSIS SHOWED A COLD FRONT EXTENDING
SOUTHWEST FROM GEORGIA TO LOUISIANA WITH PLENTY OF DRY AIR
OVERSPREADING THE REGION IN ITS WAKE. OUT AHEAD OF THIS BOUNDARY
OVER OUR AREA...MOISTURE AND DEWPOINTS HAVE INCREASED OVER THE
PAST DAY. THE MORNING UPPER SOUNDING IN MIAMI SHOWED A
PRECIPITABLE WATER VALUE OF 1.51 INCHES...WHICH IS FORECAST TO
CONTINUE TO INCREASE SLIGHTLY THROUGH TONIGHT ACROSS THE AREA.
THIS INCREASE IN MOISTURE COMBINED WITH DIURNAL HEATING AND LOCAL
SEA BREEZES WILL BE ENOUGH TO TRIGGER SCATTERED SHOWERS THIS
AFTERNOON AND ISOLATED TSTMS. THE LATEST HRRR AND WRF MODEL
REFLECTIVITIES SHOW SIMILAR RESULTS AND INDICATE MAINLY ISOLATED
TO SCATTERED AFTERNOON COVERAGE FAVORING THE INLAND AND WEST GULF
COAST AREAS TODAY.
THERE WAS A REPORT OF SOME MINOR STREET FLOODING IN THE SOUTH
BEACH AREA ALONG PURDY AVE/20TH STREET DURING THE HIGH TIDE CYCLE
THIS MORNING. THIS IS MOSTLY CONTRIBUTED TO THE PERIGEAN SPRING
TIDE AND WATER LEVELS RUNNING SLIGHT ABOVE NORMAL. EXPECT THIS
POTENTIAL TO CONTINUE AT EACH HIGH TIDE CYCLE THROUGH TUESDAY OR
WEDNESDAY BEFORE SUBSIDING. ALTHOUGH THE THREAT IS LOW...ANY
ADDITIONAL RAINFALL THAT BECOMES CONCENTRATED OVER THESE AREAS MAY
LEAD TO ADDITIONAL FLOODING OR STANDING WATER CONCERNS THROUGH
THIS TIME. THE NEXT HIGH TIDE CYCLE WILL COME LATER THIS EVENING
BETWEEN 8 AND 9 PM. 85/AG
PREV DISCUSSION... /ISSUED 721 AM EDT MON OCT 15 2012/
AVIATION...
SCATTERED SHOWERS OVER THE ATLANTIC IN MOIST E-NE LOW LEVEL WIND
FLOW WILL AFFECT PORTIONS OF E COAST THROUGH 16Z. THIS WILL KEEP
SHOWERS IN THE VICINITY OF MOST EAST COAST TERMINALS WITH BRIEF MVFR
CONDITIONS POSSIBLE BUT NOT ENOUGH TO PUT IN TAFS. ALONG WEST COAST
AT KAPF, PATCH OF BKN/OVC STRATUS BELOW 1000 FT FORECAST SLOWLY BURN
OFF BY AROUND 13Z, ALTHOUGH WOULDN`T BE SURPRISED IF LOW CEILINGS
LINGER UNTIL PERHAPS 14Z DUE TO LIGHT WINDS AND PERSISTENT NATURE OF
THE CLOUD DECK. SLIGHTLY DRIER AIR WILL TRY TO MOVE INTO SOUTH
FLORIDA AFTER 18Z, BUT WILL KEEP VCSH ALL SITES IN LIGHT NE FLOW.
EXPECT A FEW TSTMS OVER THE INTERIOR OF THE PENINSULA 17Z-00Z BUT THESE
WILL BE ISOLATED ENOUGH TO NOT MENTION AT TAF SITES. GULF SEA BREEZE
FORECAST TO AFFECT KAPF BY 18Z WITH NW WINDS. DRIER N-NE WIND FLOW
00Z-12Z TUESDAY.
PREV DISCUSSION... /ISSUED 345 AM EDT MON OCT 15 2012/
DISCUSSION...
SOME DRIER AIR HAS ALREADY BEGUN TO MOVE INTO THE AREA FROM THE EAST
WITH GPS MET DATA SHOWING THE PWAT DOWN TO 1.5-1.6 INCHES ALONG THE
ATLANTIC COAST BUT STILL 1.8-2.0 INCHES FROM THE LAKE TO NAPLES.
EVEN WITH SOME DRYING FROM THE EAST TODAY, MOISTURE WILL BE
SUFFICIENT, ALONG WITH DEVELOPING SEA BREEZES DUE TO A LIGHTER
SYNOPTIC SCALE WIND FLOW, TO ALLOW FOR SCATTERED SHOWERS TO DEVELOP
ACROSS THE AREA. THE FOCUS IS EXPECTED TO BE ACROSS THE EAST COAST
THROUGH EARLY AFTERNOON, BEFORE SHIFTING TO THE INTERIOR/GULF COAST
LATER IN THE DAY. HAVE GONE WITH THE HIGHEST POPS OVER THE INTERIOR
WHERE THE BEST CONVERGENCE IS EXPECTED. THERE COULD BE A FEW
THUNDERSTORMS AS WELL TODAY, ESPECIALLY OVER THE INTERIOR LATE THIS
AFTERNOON. GFS/ECMWF/SREF ARE IN GENERAL AGREEMENT ON THIS
SCENARIO...AND ACTUALLY OVER THE NEXT FEW DAYS.
ONSHORE WINDS ALONG THE ATLANTIC COAST WILL CONTINUE TO RELAX, BUT
THERE IS STILL A MODERATE RISK OF RIP CURRENTS. THE WEAKER ONSHORE
WINDS MAY PRECLUDE ANY COASTAL FLOODING DESPITE HIGH TIDAL LEVELS.
THIS WILL BE MONITORED OVER THE NEXT COUPLE OF DAYS AS WE ARE IN THE
SPRING TIDE WHICH RESULTS IN HIGHER THAN NORMAL WATER LEVELS.
THIS EVENING AND THROUGH TUESDAY, FURTHER DRYING IS EXPECTED TO
ENTER INTO SOUTH FL FROM THE NORTH. A SHORTWAVE WILL BE PASSING BY
TO THE NORTH TODAY FOLLOWED BY A WEAKENING FRONTAL BOUNDARY MOVING
INTO THE AREA TONIGHT AND BECOMING DIFFUSE OVER OR JUST SOUTH OF THE
AREA ON TUESDAY WHILE WASHING OUT. PWATS ARE FORECAST TO FALL INTO
THE 1.2-1.5 INCH RANGE ON TUESDAY. HOWEVER, LINGERING LOW LEVEL
MOISTURE COULD STILL ALLOW FOR ISOLATED SHOWERS ACROSS THE EAST
COAST, SO KEPT SLIGHT CHANCE POPS EAST HALF FOR TUESDAY.
THE RIP CURRENT RISK ALONG THE ATLANTIC COAST WILL CONTINUE TO
SUBSIDE OVER THE NEXT FEW DAYS. HOWEVER, ONE CAVEAT IS THAT THE
SWAN MODEL IS SHOWING A 15 SECOND EASTERLY SWELL MOVING THROUGH
THE PROVIDENCE CHANNEL OF THE BAHAMAS AND REACHING THE SOUTHERN
PALM BEACH COAST TUE AFTERNOON. GRANTED, RIGHT NOW THE MODEL ONLY
SHOWS A SWELL HEIGHT OF 2 FT, BUT THIS COULD END UP SLIGHTLY
HIGHER. EVEN SO, GIVEN THE LONG PERIOD OF THE SWELL (15 SEC),
ROUGH SURF/DANGEROUS RIP CURRENTS COULD BRIEFLY OCCUR ACROSS SE
PALM BEACH COUNTY ON TUESDAY AFTERNOON/EVENING.
ANOTHER SHORTWAVE DIGS INTO THE GULF AND APPROACHES SOUTH FL ON WED,
WITH MOISTURE INCREASING IN ADVANCE OF THIS TROUGH. SEA BREEZE
CONVERGENCE IS EXPECTED WED, AND WITH THE HIGHER MOISTURE, THERE`S A
BETTER CHANCE OF SHOWERS AND A FEW THUNDERSTORMS ESPECIALLY
INTERIOR-EAST ON WED...DUE TO A MEAN WESTERLY STORM STEERING FLOW.
FOR LATE WEEK INTO NEXT WEEKEND, BOTH GFS/ECMWF SHOW A STRONG CLOSED
MID/UPPER LOW DIVING ACROSS THE GREAT LAKES STATES WITH A TROUGH
EXTENDING SOUTH INTO THE GULF OF MEXICO. BOTH MODELS SHOW WARM,
HUMID CONDITIONS LATE WEEK AHEAD OF THIS SYSTEM AND JUST CANNOT
SHUT MENTION OF SHOWERS/TSTORMS OFF ANY DAY DUE TO SUFFICIENT
MOISTURE/INSTABILITY CONTINUING...ESPECIALLY OVER THE WEEKEND.
BOTH MODELS HAVE BEEN GRADUALLY BACKING OFF ON THE THRUST OF THIS
COLD FRONT FOR SOUTH FLORIDA...ESPECIALLY NOW THE GFS WHICH KEEPS
DEWPOINTS IN THE LOWER 70S ALL THE WAY THROUGH NEXT WEEKEND AND
INTO NEXT WEEK. THE ECMWF SHOWS SLIGHTLY DRIER AIR BEHIND THE
BOUNDARY BY MONDAY...BUT EVEN IT SHOWS WINDS QUICKLY TO THE EAST
BEHIND IT. SO THE BOTTOM LINE IS WARM, HUMID CONDITIONS LOOK TO
PREVAIL THROUGH THE FORECAST PERIOD ALONG WITH DAILY CHANCES OF
SHOWERS/TSTORMS.
MARINE...WINDS ARE CONTINUING TO DECREASE ACROSS THE LOCAL
WATERS. SWAN OUTPUT SHOWS SIG WAVEHEIGHT OF 7 FT EARLY THIS
MORNING OVER THE PALM BEACH WATERS BEFORE DECREASING THROUGHOUT
THE DAY. SO WILL CONTINUE THE SMALL CRAFT ADVISORY FOR JUST THE
PALM BEACH WATERS THROUGH 8 AM THIS MORNING. THEN SEAS OF 4 FT OR
LESS ARE EXPECTED THROUGH LATE WED BEFORE EVEN LOWERING FURTHER
LATE WEEK AS LIGHT WINDS PREVAIL.
SWAN SHOWS A LONG PERIOD (15 SECONDS) SWELL MOVING THROUGH THE
PROVIDENCE CHANNEL ONSHORE SOUTHERN PALM BEACH COUNTY TUE
AFTERNOON-NIGHT, UP TO 2 FT. THIS IS ORIGINATING FROM
TROPICAL STORM RAFAEL MOVING NNW WELL TO OUR EAST ALONG ABOUT 65
DEGREES WEST LONGITUDE. WILL HAVE TO WATCH THIS FOR A BRIEF PERIOD
OF POTENTIALLY ROUGH SURF/RIP CURRENTS ALONG THE SOUTHERN PALM
BEACH COAST.
FIRE WEATHER...NO CONCERNS AS RH`S REMAIN ELEVATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 74 86 71 84 / 10 20 20 40
FORT LAUDERDALE 76 87 74 85 / 10 20 20 40
MIAMI 75 87 73 85 / 10 20 20 40
NAPLES 72 86 71 84 / 20 10 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...55/CWC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 PM EDT MON OCT 15 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 414 PM EDT MON OCT 15 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH EAST
OF LAKE HURON LEAVING MAINLY ZONAL FLOW TO THE WEST FROM THE PAC NW TO
THE UPPER MS VALLEY. AN UPSTREAM SHORTWAVE TROUGH WAS MOVING FROM
THE NRN ROCKIES INTO THE NRN PLAINS. AT THE SFC...A RIDGE WAS
BUILDING ACROSS WRN LAKE SUPERIOR AND W UPPER MI. SRLY WINDS WERE
INCREASING OVER MN AHEAD OF A TROUGH FROM SRN MANITOBA INTO THE
CNTRL DAKOTAS. VIS LOOP SHOWED CLEARING SKIES OVER THE W HALF OF
UPPER MI. HOWEVER...HIGH CLOUDS SUPPORTED BY WAA AHEAD OF THE TROUGH
WERE QUICKLY STREAMING FROM MN INTO WRN WI. SOME LIGHT RAIN HAD ALSO
DEVELOPED FROM NEAR WINNIPEG INTO NW MN WITH WAA/ISENTROPIC LIFT
AHEAD OF THE TROUGH.
THE MODELS WERE IN GOOD AGREEMENT WITH THE MID LEVEL TROUGH DIGGING
FROM THE NRN PLAINS INTO THE UPPER MS VALLEY TONIGHT INTO TUE.
EXPECT THE AREA OF RAIN TO THE WEST TO EXPAND LATE TONIGHT AND
SPREAD INTO THE WRN CWA AS 925-850 MB MOISTURE TRANSPORT AND
295-300K ISENTROPIC LIFT INCREASE. AS THE 850-700 MB WARM FRONT
MOVES THROUGH THE AREA TUE...PCPN WILL SPREAD ACROSS THE CWA.
ALTHOUGH LIKELY-CATEGORICAL POPS WERE WARRANTED...THE HEAVIER PCPN
(INTO THE 0.25 TO 0.50 RANGE) IS EXPECTED MAINLY ACROSS THE NORTH
AND EAST FROM THE KEWEENAW INTO THE ERN CWA WHERE THE STRONGEST LIFT
AHEAD OF THE 850 MB WARM FRONT IS PROGGED....PER NAM/REGIONAL-GEM.
MODELS TIMING HAS ALSO BEEN CONSISTENT WITH THE PCPN ENDING OVER THE
WEST BY EARLY AFTERNOON AND OVER THE EAST LATE.
TEMPS WILL DROP INTO THE LOW TO MID 30S THIS EVENING BEFORE THE
CLOUDS THICKEN AND SRLY WINDS INCREASE RESULTING IN SLOWLY CLIMBING
TEMPS OVERNIGHT. AS THE PCPN ENDS TUE AFTERNOON...WAA WILL ALSO DRAW
ENOUGH WARM AIR INTO THE REGION TO PUSH MAX READINGS INTO UPPER 50S
WEST WHILE TEMPS LINGER AROUND 50 OVER THE EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 414 PM EDT MON OCT 15 2012
MID WEEK WILL REMAIN UNSETTLED AS A DEEP UPPER TROUGH OVER THE
CANADIAN PRAIRIE PROVINCES CLOSES OFF OVER THE UPPER MIDWEST/GREAT
LAKES. THIS WILL ALLOW FOR PRECIPITATION CHANCES THROUGH THURSDAY
WITH AT OR SLIGHTLY BELOW NORMAL TEMPERATURES.
FOR THE DETAILS...EXPECT THE WARM ADVECTION/ISENTROPIC LIFT PCPN
ASSOCIATED WITH THE 850MB WARM FRONT TO MOVE EAST OF THE FORECAST
AREA TUESDAY NIGHT...LEADING TO THE AREA BEING IN THE WARM SECTOR
AHEAD OF THE DEEP SFC LOW AND OCCLUDED FRONT EXTENDING FROM LAKE
WINNIPEG INTO THE PLAINS. WILL MAINTAIN LOW CHANCE POPS IN THE
EVENING EAST OF MARQUETTE DUE TO CONTINUED WEAK ISENTROPIC LIFT AND
MID LVL Q-VECT CONVERGENCE. LOW CLOUDS/FOG WILL REMAIN A CONCERN
OVERNIGHT DUE TO CLEARING SKIES AND LEFTOVER LOW LEVEL MOISTURE FROM
AFTN/EVENING RAINFALL AND AS SUCH HAVE MAINTAINED FOG CHANCES.
THE OCCLUDED FRONT WILL MOVE EAST ON WEDNESDAY AS THE UPPER SYSTEM
CLOSES OFF. EXPECT A BAND OF SHOWERS TO MOVE INTO THE WESTERN U.P.
WEDNESDAY AFTERNOON ASSOCIATED WITH PRECIPITABLE WATER VALUES IN
EXCESS OF 1 INCH AND MID LVL Q-VECTOR CONVERGENCE. DUE TO THE LOW
CLOSING OFF...THE BAND OF SHOWERS WILL ONLY SLOWLY MOVE EAST WED
AFTN/NIGHT. IN FACT...THERE WILL LIKELY BE A PROLONGED PERIOD OF
STEADY RAIN WED EVENING ACROSS UPPER MICHIGAN DUE TO THE ROTATION
AND TIGHTENING OF THE 850MB ISOTHERMS CONTRIBUTING TO INCREASED
FN/FS VECTOR CONVERGENCE IN THE TROWAL REGION. WILL THEREFORE
MAINTAIN LIKELY POPS ACROSS THE ENTIRE U.P. WED NIGHT.
TRICKY AND UNCERTAIN FORECAST FOR THURSDAY. THE ECMWF SUGGESTS THAT
MOST OF THE U.P. WILL BE DRY WITH THE COMMA HEAD MOISTURE/PCPN BACK
INTO MN AND NW WISCONSIN DUE TO THE UPPER LOW BEING FURTHER WEST
THAN THE GFS WHICH HAS THE UPPER LOW OVERHEAD. AM THINKING THAT THE
BEST CHANCES FOR PCPN WILL BE ACROSS THE WEST AND HAVE OPTED TO
MAINTAIN HIGH CHANCE POPS FOR THAT AREA. DUE TO SIGNIFICANT
UNCERTAINTY...WILL STILL NEED TO MAINTAIN CHANCE POPS TO THE EAST.
CONFIDENCE IN THE EXTENDED FORECAST FOR FRIDAY-MONDAY STILL QUITE
LOW WITH DIFFERENCES BETWEEN THE ECWMF...GFS AND CANADIAN IN HOW
FAST THE GREAT LAKES CLOSED LOW EJECTS TO THE NORTHEAST. TEND TO
BELIEVE THE SLOWER ECMWF SOLUTION WHICH WOULD KEEP A DRIER FORECAST
FOR THE UPPER LAKES FOR THE WEEKEND DUE TO UPPER RIDGING HANGING ON
ACROSS THE UPPER MIDWEST. THE BELOW CONFIDENCE FORECAST NOT ONLY
APPLIES TO PRECIPITATION CHANCES...BUT ALSO TO TEMPERATURES AS THE
ECMWF WOULD BE WARMER COMPARED TO THE CLOUDY/COOL GFS.
WITH ALL OF THIS SAID...WILL TREND TOWARD THE 00Z AND 12Z ECMWF AND
LOWER POPS TO SLIGHT CHANCE OR LOW CHANCE POPS EACH DAY IN THE
EXTENDED. IN FACT IF THE 00Z ECMWF VERIFIES IT WILL END UP BEING A
DECENT WEEKEND. ON THE OTHER HAND...IF THE GFS VERIFIES IT COULD BE
MUCH WETTER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 143 PM EDT MON OCT 15 2012
EXPECT CONDITIONS TO IMPROVE TO VFR AT CMX AND SAW BY LATE AFTERNOON
AS A RIDGE WITH BACKING WINDS AND DRIER AIR MOVES INTO THE REGION.
ANOTHER TROUGH WILL MOVE TOWARD THE AREA TONIGHT BRINGING THICKENING
CLOUDS AND THE POTENTIAL FOR SOME LIGHT RAIN LATE TONIGHT. EXPECT
RAIN WITH MVFR CIGS TO MOVE IN TUESDAY...WITH CIGS BLO 2K FT MORE
LIKELY AT CMX AND SAW WITH LOCAL SE OR SRLY FLOW THAT FAVORS LOWER
CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 414 PM EDT MON OCT 15 2012
WINDS WILL CONTINUE TO DIMINISH THIS EVENING AS HIGH PRES BUILDS
INTO THE REGION. ANOTHER LOW PRESSURE TROUGH APPROACHING THE UPPER
GREAT LAKES LATE TONIGHT WILL RESULT IN SOUTH WINDS OF 15 TO 25 KT
WITH AREAS TO NEAR 30 KT OVER ERN LAKE SUPERIOR LATE TUE AFTERNOON
AND EVENING. A DEEPER LOW PRESSURE SYSTEM MOVING INTO THE UPPER GREAT LAKES
ON THURSDAY COULD CAUSE AN INCREASE IN ERLY WINDS TO 30 KT LATE WED
NIGHT INTO THURSDAY. OTHERWISE...WINDS IN THE VICINITY OF THE LOW
SHOULD GENERALLY REMAIN LESS THAN 20 KTS WEDNESDAY THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1232 PM CDT MON OCT 15 2012
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE. A FRONT WILL
BRING A FEW MID-LEVEL CLOUDS...BUT MORE IMPORTANTLY...A SHIFT
FROM SOUTHERLY WINDS AT OR BELOW 10KT TO NORTHWESTERLY WINDS
GUSTING TO AROUND 22-25KT BY LATE TUESDAY MORNING.
MAYES
&&
.PREV DISCUSSION... /ISSUED 332 AM CDT MON OCT 15 2012/
DISCUSSION...
MAIN FORECAST CHALLENGE WILL BE HIGH TEMPERATURES OVER THE NEXT
COUPLE DAYS AND PRECIPITATION CHANCES TUESDAY NIGHT INTO MID
WEEK.
LATEST WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWS THE NATIONS
MID SECTION IN NORTHWEST FLOW LYING IN BETWEEN A TROUGH TO OUR
EAST AND A WEAK RIDGE TO THE WEST. SHORTWAVE ENERGY CURRENTLY OVER
THE NORTHWEST CONUS IS FORECAST TO RIDE DOWN THE WEAK RIDGE AND
TOWARD CENTRAL NEBRASKA BY 06Z TONIGHT. AS WEAK SFC LOW PRESSURE
MOVES ACROSS THE NRN PLAINS AHEAD OF THIS UPPER SHORTWAVE...THE
FORECAST AREA WILL BE UNDER WEAK SOUTHERLY SFC FLOW. COMBINED WITH
LOW LEVEL WARM AIR ADVECTION THROUGHOUT THE DAY...TODAY WILL BE
VERY MILD WITH HIGHS APPROACHING UPPER 70S TO NEAR 80. STRONGER
MIXING IS LIKELY ON TUESDAY AHEAD OF AN APPROACHING COOL FRONT IN
ADVANCE OF ABOVE MENTIONED UPPER LEVEL SHORTWAVE. HIGHS SHOULD
APPROACH 80 ONCE AGAIN WITH SLIGHTLY COOLER READINGS IN OUR FAR
NORTHERN COUNTIES BEHIND THE COOL FRONT.
A STRONGER UPPER LEVEL SHORTWAVE TROUGH WILL PUSH ACROSS MONTANA AND
CLOSE OFF AS IT SKIRTS THE NORTH DAKOTA/CANADIAN BORDER MID WEEK.
THIS WILL PUSH A STRONGER COLD FRONT INTO THE FORECAST AREA BY
WEDNESDAY MORNING. INCREASING MOISTURE AND FRONTOGENETICAL FORCING
SHOULD BE ENOUGH TO GENERATE LIGHT PCPN BEHIND THE SURFACE FRONT
THROUGH THE DAY WEDNESDAY. INCREASING PRESSURE GRADIENT BEHIND THE
BOUNDARY WILL CREATE BREEZY IF NOT WINDY CONDITIONS THROUGH THE
DAY WEDNESDAY.
THE UPPER CLOSED LOW WILL CONTINUE TO SINK SOUTHEAST AND DEEPEN AS
IT MOVES INTO THE GREAT LAKES REGION LATE IN THE SCHOOL/WORK WEEK.
DEPENDING ON LOCATION AND TIMING...AREA COULD SEE RAIN SHOWERS SINK
SOUTH INTO THE CWA AROUND THE BACKSIDE OF THE UPPER LOW. ALREADY HAD
POPS GOING FOR THURSDAY SO WILL CONTINUE. ALSO LOOKS AS THOUGH SFC
PRESSURE GRADIENT WILL REMAIN QUITE STRONG WHILE 850MB NORTHWEST
WINDS ARE FORECAST AROUND 45-55KTS. SOME OF THIS WOULD LIKELY MIX
DOWN AND CREATE QUITE BLUSTERY CONDITIONS THROUGH LATE WEEK.
QUIET AND WARMER CONDITIONS ARE EXPECTED INTO THE WEEKEND.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
153 PM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE CAROLINAS AND SOUTHERN VIRGINIA THIS
AFTERNOON AND THIS EVENING. COOL HIGH PRESSURE WILL BUILD INTO THE
REGION IN THE WAKE OF THE FRONT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM MONDAY...
FOR THE REST OF TODAY:
THE LATEST SURFACE MAP DEPICTS THE COLD FRONT STILL BACK OVER FAR
ERN TN... MOVING SLOWLY EASTWARD. JUST OFF THE SURFACE... 35-40 KT
SWRLY JET AT 925 MB AND 40-50 KT JETTING AT 850 MB STRETCHES FROM
WRN NC INTO NEW ENGLAND. FURTHER ALOFT... DEEP MID LEVEL TROUGHING
FROM ONTARIO THROUGH MI TO LA WILL SWING EASTWARD AND DEEPEN FURTHER
TODAY... SPREADING INTENSE HEIGHT FALLS (80-120 METERS IN 12 HRS)
OVER NC/VA LATER TODAY. THIS TROUGH`S APPROACH WILL STRENGTHEN THE
UPPER JET OVER MD/PA/NY THIS AFTERNOON... INSTIGATING STRONG UPPER
DIVERGENCE OVER CENTRAL/ERN NC... JUST AHEAD OF STRONG MID LEVEL
DPVA.
THE RISK OF SHOWERS AND STORMS GENERATING STRONG WIND GUSTS WILL
PERSIST THROUGH THE AFTERNOON. AN INITIAL BROAD BAND OF HEAVY
SHOWERS AND STORMS MOVING THROUGH THE TRIAD AND WRN PIEDMONT APPEARS
TO BE LINKED TO A MID LEVEL WAVE NOTED ON WATER VAPOR IMAGERY
PUSHING THROUGH THE SRN/CENTRAL MOUNTAINS/FOOTHILLS. AS THIS FEATURE
CONTINUES TO LIFT RAPIDLY NE... THIS HEAVY PRECIP AREA SHOULD
LIKEWISE TRANSLATE NNE INTO VA... LEAVING BEHIND A THIN BROKEN LINE
OF WEAKER SHOWERS FOR A FEW HOURS. AS THE UPPER DIVERGENCE
STRENGTHENS WITH THE APPROACH OF THE SURFACE FRONT BY EARLY TO MID
AFTERNOON... THE IMPROVING DYNAMICS WILL COINCIDE WITH MARGINAL
DESTABILIZATION (800-1200 J/KG MLCAPE)... AND REDEVELOPMENT OF A
BAND OF STORMS OVER THE CENTRAL/ERN PIEDMONT APPEARS LIKELY JUST
AHEAD OF THE FRONT... A SCENARIO DEPICTED BY THE LATEST HRRR MODEL
RUNS. FORECAST RAIN CHANCES FOR TODAY REFLECT SUCH A TIMING SCENARIO
FAIRLY WELL AND ONLY SMALL CHANGES ARE NEEDED.
THE LOW LEVEL JET IS EXPECTED TO WEAKEN A BIT OVER NC AS THE HEART
OF THE JET LIFTS TO OUR NORTH... HOWEVER THE OTHERWISE FAVORABLE
KINEMATICS COMBINED WITH LARGER SCALE FORCING ROOTED IN THE UPPER
LEVELS... STILL-FORMIDABLE LOWER LEVEL MASS CONVERGENCE... 30-40 KTS
OF DEEP LAYER SHEAR... AND MARGINAL INSTABILITY MAY LEAD TO A FEW
DISCRETE BOWING SEGMENTS EMBEDDED WITHIN THE LARGER LINE OF
CONVECTION. BACKGROUND WINDS ALONE WILL SUPPORT PERIODIC GUSTS OF
25-30 KTS WITH ANY CONVECTION... AND STRONGER GUSTS OVER 45 KTS
REMAIN POSSIBLE IN CONJUNCTION WITH ANY BOWING SEGMENTS OR DISCRETE
CELLS. FAIRLY MEAGER MID LEVEL LAPSE RATES WILL PRECLUDE A MAJOR
HAIL THREAT... PARTICULARLY CONSIDERING THE LACK OF A BROAD "FAT"
CAPE TO SUPPORT ESPECIALLY VIGOROUS UPDRAFTS... ALTHOUGH IF WE CAN
GET A FEW HOURS OF SUNSHINE IN THE COASTAL PLAIN... POCKETS OF
HIGHER CAPE AND STRONGER DIFFERENTIAL HEATING COULD INTENSIFY
CONVECTION THERE. FINALLY... TRAINING OF SHOWERS AND STORMS
PARTICULARLY OVER URBAN AREAS COULD LEAD TO LOCALIZED FLOODING
PROBLEMS IN SUSCEPTIBLE LOCATIONS THROUGH THIS AFTERNOON. WILL MAKE
APPROPRIATE ADJUSTMENTS TO THE HAZARDOUS WEATHER OUTLOOK TO REFLECT
THIS.
TEMPS ARE A CHALLENGE GIVEN THE STEADY PRECIP OVER THE WRN CWA
BALANCED WITH THE STRONG WARM AIR ADVECTION. WILL MAKE A MINOR
DOWNWARD ADJUSTMENT MAINLY IN THE WEST WHERE READINGS HOLD IN THE
LOW-MID 60S. OVERALL... EXPECT HIGHS NEAR 70 TO THE MID 70S. -GIH
TONIGHT...WITH FROPA OCCURRING LATER THIS AFTERNOON THROUGH EARLY
EVENING AND STRONG SUBSIDENCE NOTED BEHIND THE FRONT...EXPECT
SHOWERS TO END QUICKLY WITH THE FRONTAL PASSAGE...WITH SKIES
CLEARING SHORTLY AFTER. STEADY NW FLOW OVERNIGHT WILL USHER A COOLER
AND DRIER AIR MASS INTO THE REGION. MOS GUIDANCE ACCEPTED WITH MINOR
TWEAKS. -WSS
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 255 AM MONDAY...
TUESDAY AND TUESDAY NIGHT...SURFACE HIGH PRESSURE WILL BUILD INTO
AND CROSS THE REGION. 850MB THERMAL TROUGH OVER THE AREA THROUGH
TUESDAY NIGHT. THIS RESULTS IN THICKNESSES IN THE MID 1360S TUESDAY
AFTERNOON...ABOUT 10-12M BELOW NORMAL. THIS SUPPORTS MAX TEMPS ABOUT
3-5 DEGREES COOLER THAN NORMAL. MAX TEMPS TUESDAY MID 60S N-NW TO
AROUND 70 SOUTH.
SURFACE RIDGE EXTENDS ACROSS REGION TUESDAY NIGHT. THIS WOULD
SUGGEST SURFACE WINDS DECOUPLING NEAR SUNSET. WOULD NORMALLY EXPECT
CLEAR SKIES IN THIS REGIME BUT SEVERAL OF THE MODELS DEPICT AN
INCREASE IN HIGH LEVEL MOISTURE ASSOCIATED WITH A MID-UPPER S/W IN
THE WLY FLOW ALOFT. THE GFS QUITE MOIST ABOVE 500MB...DEPICTING A
SOLID VEIL OF CIRRUS. THE ECMWF AND NAM NOT AS ROBUST BUT DO HINT AT
POTENTIAL FOR HIGH LEVEL CLOUDINESS. THUS...EXISTENCE OF CIRRUS
SHIELD MAY BE ENOUGH TO PREVENT SURFACE AIR MASS FROM REALIZING FULL
COOLING POTENTIAL. WILL FORECAST MIN TEMPS IN THE 40-45 DEGREE
RANGE. IF CIRRUS SHIELD THINNER THAN ANTICIPATED...THIS WOULD LEAD
TO COOLER MIN TEMPS AND SOME UPPER 30S PROBABLE AT THE NORMALLY
COLDER SITES. -WSS
WEDNESDAY AND WEDNESDAY NIGHT:
SURFACE HIGH PRESSURE IS EXPECTED TO MOVE OFFSHORE ON WEDNESDAY
ALLOWING FOR A WARMING SOUTHERLY RETURN FLOW TO DEVELOP. HOWEVER...
THIS MAY BE TEMPERED A BIT BY A WEAK S/W ALOFT TRACKING ACROSS THE
AREA WEDNESDAY MORNING INTO AFTERNOON (WITH THE STRONGEST PORTIONS
OF THE IMPULSE STAYING TO THE SOUTH OF THE AREA). THIS SHOULD ALOFT
FOR A PERIOD OF SCATTERED TO BROKEN MID/HIGH LEVEL CLOUDS ON
WEDNESDAY MORNING INTO THE AFTERNOON... WITH CLEARING SKIES FROM NW
TO SE IN THE AFTERNOON TO LATE AFTERNOON. NOT EXPECTING ANY PRECIP
WITH THIS FEATURE AS PW`S WILL REMAIN GENERALLY NEAR OR BELOW 0.60".
AFTERNOON LOW LEVEL THICKNESS VALUES ARE EXPECTED TO TOP OUT IN THE
1365 TO 1370 METER RANGE. THIS SHOULD GENERALLY YIELD TEMPS FROM THE
LOWER TO MID 70S ACROSS THE AREA.
WEDNESDAY NIGHT EXPECT SKIES WILL GENERALLY BE MOSTLY CLEAR OUTSIDE
OF SOME INCREASING HIGH LEVEL CLOUD COVER AHEAD OF THE NEXT SYSTEM
EXPECTED TO AFFECT THE AREA IN THE EXTENDED PORTION OF THE FORECAST.
HOWEVER... WITH THE SURFACE HIGH TO THE EAST OF THE AREA EXPECT
OVERNIGHT LOWS WILL NOT BE AS COOL/COLD AS THE PREVIOUS NIGHT.
THUS... WILL GO WITH LOWS THURSDAY MORNING IN THE UPPER 40S TO LOWER
50S. -BSD
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 305 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT SHOWING A CLOSED LOW
DEVELOPING/MOVING INTO THE UPPER MIDWEST AND GREAT LAKES REGION LATE
WEEK... CREATING A FULL LATITUDE TROUGH OVER THE EASTERN HALF OF THE
COUNTRY. HOWEVER... MODELS CONTINUE TO STRUGGLE WITH THE PROGRESSION
OF THIS SYSTEM.
AS THE ABOVE MENTIONED UPPER LOW SLOWLY SHIFTS EASTWARD AND
EVENTUALLY BEGINS TO LIFT NORTH-NORTHEASTWARD EXPECT AN ASSOCIATED
COLD FRONT WILL APPROACH CENTRAL NC ON THURSDAY... MOVING INTO THE
AREA SOMETIME IN THE LATE THURSDAY TO FRIDAY TIMEFRAME. MODELS
CONTINUE TO STRUGGLE WITH THE TIMING OF THE FRONT AND ITS
PROGRESSION THROUGH THE AREA... WITH THE OPERATIONAL 00Z GFS AND
CANADIAN SHOWING THE LEADING FRONT TO THE EAST OF THE AREA BY MID TO
LATE FRIDAY. WITH THE 12Z HIRES ECMWF SHOWING THE FRONT STILL TO THE
WEST OF THE AREA AT THIS TIME (ECMWF MOVES THE FRONT SLOWLY THROUGH
THE AREA FROM FRIDAY NIGHT TROUGH SATURDAY AFTERNOON). THUS... MUCH
UNCERTAINTY STILL EXISTS FOR THE THURSDAY NIGHT THROUGH SATURDAY
TIMEFRAME. HOWEVER... WITH THE 00Z LOWRES ECMWF SHOWING THE FRONT
MOVING THROUGH THE AREA A BIT QUICKER THAN PREVIOUSLY INDICATED WILL
NARROW THE TIME RANGE FOR CHANCE POPS DOWN A BIT AND ACCORDINGLY
ADJUST TEMPS TO FIT A BIT FASTER FRONTAL PASSAGE THAN PREVIOUSLY
INDICATED... WITH DRY WEATHER RETURNING BY MID/LATE SATURDAY THROUGH
SUNDAY AS SURFACE HIGH PRESSURE BUILDS BACK INTO THE REGION. FOR NOW
WILL GO WITH CHANCE POPS THURSDAY NIGHT INTO FRIDAY NIGHT... WITH
ONLY A SLIGHT CHANCE FOR SATURDAY WITH THE POTENTIAL OF THE SLOWER
ECMWF AND POSSIBLE POST FRONTAL PRECIP.
EXPECT HIGH TEMPS ON THURSDAY WILL RANGE FROM THE LOWER 70S IN THE
NW TO NEAR 80 IN THE SE... WITH THE POTENTIAL FOR HIGHS TO BE A BIT
COOLER IN THE NW IF THE MORE PROGRESSIVE SET OF GUIDANCE IS CORRECT
AND MOVES THE FRONT INTO OUR NW THURSDAY AFTERNOON. LOWS AND HIGHS
FRIDAY AND SATURDAY WILL ULTIMATELY DEPEND ON THE TIMING OF THE
FRONT... THUS... TRICKY LOW AND HIGH TEMP FORECAST. FOR NOW WILL GO
WITH HIGHS IN THE MID TO UPPER 60S NW TO LOWER TO MID 70S E. EXPECT
LOWS FRIDAY MORNING TO RANGE FROM THE LOWER 50S NW TO AROUND 60
SE... WITH LOWS SATURDAY MORNING EXPECTED TO RANGE FROM THE AROUND
50 NW TO THE UPPER 50S NEAR 60 IN THE EAST. EXPECT LOWS SUNDAY
MORNING TO RANGE FROM THE MID 40 TO AROUND 50. HIGH SUNDAY ARE
EXPECTED TO BE IN THE MID/UPPER 60S TO NEAR 70 IN THE SE.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 150 PM MONDAY...
AVIATION CONDITIONS WILL SHOW AN IMPROVING TREND OVER THE NEXT 6-9
HOURS. IFR CIGS AT INT/GSO WILL MIX OUT WITH CIGS RISING TO VFR
AFTER 20Z THIS AFTERNOON... BEHIND A COLD FRONT THAT WILL MOVE
EASTWARD THROUGH CENTRAL NC LATE AFTERNOON THROUGH VERY EARLY
EVENING. THE FRONT WILL MOVE INT/GSO AT 19-21Z AND THROUGH
RDU/FAY/RWI 21Z-23Z. SW WINDS UNDER 12 KTS WILL SWING AROUND TO
WESTERLY OR FROM THE WNW WITH FRONTAL PASSAGE AT SPEEDS OF 8-12 KTS
GUSTING TO 15-20 KTS FOR A FEW HOURS... BEFORE WINDS COME OUT OF THE
NORTH AND DECREASE TO UNDER 8 KTS LATE EVENING ONWARD. SCATTERED
STORMS ARE EXPECTED NEAR RDU/FAY BETWEEN 18Z AND 22Z... AND NEAR RWI
19Z-23Z... AND BRIEF MVFR OR IFR CIGS ARE POSSIBLE BUT UNLIKELY TO
LAST MORE THAN AN HOUR. LINGERING VFR CIGS ESPECIALLY NEAR FAY THIS
EVENING WILL DISSIPATE AFTER 03Z WITH GENERALLY CLEAR SKIES AND CALM
CONDITIONS AREAWIDE OVERNIGHT THROUGH 18Z TUESDAY.
LOOKING BEYOND EARLY TUESDAY AFTERNOON... VFR CONDITIONS ARE LIKELY
TUESDAY THROUGH WEDNESDAY WITH ONLY HIGH CLOUDS AFFECTING THE AREA
UNDER HIGH PRESSURE. A PERIOD OF MVFR/IFR CIGS/VSBYS IN FOG IS
POSSIBLE EARLY THURSDAY MORNING WITH BORDERLINE LLWS CONDITIONS AS
SW WINDS STRENGTHEN ABOVE 2 KFT. ISOLATED SHOWERS WITH MVFR
CONDITIONS ARE POSSIBLE FRIDAY AFTERNOON WITH AN APPROACHING WEAK
COLD FRONT. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS/BSD
LONG TERM...BSD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
640 PM EDT MON OCT 15 2012
.SYNOPSIS...
A COLD FRONT OVER FAR EASTERN PENNSYLVANIA THIS EVENING WILL EXIT
OFF THE MID ATLANTIC COAST OVERNIGHT. MAINLY DRY AND MILD WEATHER
WILL FOLLOW FOR THE MID-WEEK PERIOD. A DEEP UPPER LEVEL LOW WILL
DEVELOP OVER THE UPPER PLAINS AND MIDWEST OVER THE NEXT FEW DAYS.
THE DEEP LOW WILL THEN MOVE TO THE EAST AND PUSH A COLD FRONT
THROUGH LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SFC COLD FRONT IS CURRENTLY APPROACHING THE DELAWARE VALLEY AND
WILL MOVE OFF THE MID ATLANTIC COAST OVERNIGHT. STRATIFORM RAIN
HAS EXITED OUR FAR SERN ZONES...FOLLOWED BY SOME PARTIAL CLEARING
AS LLVL DOWNSLOPE WESTERLY FLOW KICKS IN ACROSS THE CENTRAL MTS
AND SUSQ VALLEY THIS EVENING...AND THE DEEPER LIFT ALOFT WANES
AS THE LEFT ENTRANCE REGION OF A NORTH/SOUTH 115 KT UPPER JET
DRAGS ACROSS CENTRAL PENN AND THE SUSQUEHANNA REGION.
FURTHER WEST...STRONG MID LEVEL /700-500MB/ COLD ADVECTION AND A
POCKET OF STEEP 850-700 MB LAPSE RATES WAS SUPPORTING AN AREA OF
LIGHT TO MODERATE RAIN SHOWERS MOVING ACROSS THE WEST CENTRAL MTNS
AND LAUREL HIGHLANDS. LATEST HRRR GUIDANCE SHOWS THIS AREA OF
SHOWERS DWINDLING AS IT MOVES EAST OF THE ALLEGHENY FRONT BETWEEN
23-01Z.
RAINFALL AMOUNTS ACROSS THE SW 1/4 OF THE CWA WILL RANGE FROM JUST
A FEW HUNDREDTHS...TO AROUND 0NE TENTH OF AN INCH IN SOME SPOTS.
THIS POCKET OF COLD AIR ALOFT WITH 700 MB TEMPS INITIALLY AROUND
-8C EARLY THIS EVENING...WILL GRADUALLY FILL/WARM BY 3-4C AS IT
CROSSES CENTRAL PENN...AND REACHES THE SUSQ VALLEY LATE TONIGHT.
A FEW BRIEF SHOWERS ARE POSSIBLE THROUGH EARLY TONIGHT ACROSS THE
CENTRAL RIDGE AND VALLEY REGION /MORE LIKELY SPRINKLES/...BUT MOST
LOCATIONS WILL NOT SEE ENOUGH RAIN TO WET THE GROUND.
GUSTY WEST WINDS ACROSS THE CENTRAL AND WESTERN ZONES
AT DUSK WILL SLACKEN OFF BY MIDNIGHT...BUT THEY WON/T GO CALM
OVERNIGHT CONSIDERING THAT THE RIDGE AXIS IS STILL SEVERAL HUNDRED
MILES OFF TO THE WEST.
THE MOISTURE LAYER BECOMES THINNER AS SUBSIDENCE INCREASES AND
UPPER HEIGHTS RISE LATE TONIGHT....AND PRACTICALLY ALL OF THE
SHOWERS WILL HAVE ENDED BY 07-09Z TUESDAY /EXCEPT FOR THE
LINGERING LAKE EFFECT VARIETY NEAR AND TO THE WEST OF KBFD/.
LOWS TONIGHT WILL BE RIGHT AROUND NORMAL WITH M-U30S ACROSS THE NW
AND M40S IN THE SE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
ANY ISOLD SHRA IN THE NW SHOULD BE DONE AROUND SUNRISE TUES...SO
WILL KEEP POPS NIL AREAWIDE FOR THE DAYTIME. DAYTIME TEMPS WILL
REMAIN VERY CLOSE TO SEASONAL NORMALS...TOPPING OUT IN THE M50S-
M60S. RIDGE AXIS STILL OFF TO THE WEST IN THE MORNING...BUT
OVERHEAD LATE IN THE DAY...SO WINDS SHOULD BEGIN 8-10KTS AND COULD
INCREASE/GUST A LITTLE BUT THEN LIGHTEN UP - ESP IN THE W -
THROUGH THE AFTN. AN UNEVENTFUL BUT TYPICAL AUTUMN DAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE RIDGE OVER THE REGION FOR MIDWEEK WITH WESTERLY
FLOW TURNING SW ALOFT AHEAD OF DEVELOPING TROUGH. SO DRY WEATHER
WILL PREVAIL TUE NIGHT INTO THU. CHILLY NIGHT TUE NIGHT WITH LOWS IN
THE 30S...BUT RETURN FLOW ON BACK SIDE OF HIGH WILL PUSH TEMPS
SLIGHTLY ABOVE NORMAL ON WED. MILDER NIGHT WED NIGHT...THEN
INCREASING CLOUD COVER WILL BRING SEASONAL TEMPS FOR THU.
TROUGH EDGES TOWARD PA LATE WEEK...WITH FRONT RUNNING OUT AHEAD OF
SYSTEM FOR THU NIGHT/FRI BRINGING BEST CHANCE FOR WIDESPREAD RAIN
THIS WEEK. EASTERN SECTIONS COULD SEE HIGHEST AMOUNTS...WITH QPF
AROUND 0.25 INCHES...POSS UP TO 0.75 INCHES ON EASTERN EDGE.
UNFORTUNATELY...MODELS REMAIN STEADFAST IN THEIR DIFFERENCES THIS
WEEKEND WITH GFS REMAINING WEAKER AND MORE PROGRESSIVE WHILE THE
ECMWF STICKS WITH A LARGER AND SLOWER MOVING LOW. SO FORECAST
CONTINUES TO TRY TO MITIGATE THESE DIFFERENCES INTO A COMPROMISE
SOLUTION. AFTER BEST RAIN CHANCES CENTERED ON FRIDAY...KEPT SCT
SHOWERS POSS INTO THE WEEKEND WITH DRYING TREND LATE. TEMPS DO
COOL OFF A BIT OVER THE WEEKEND INTO EARLY NEXT WEEK...BUT REMAIN
CLOSE TO SEASONAL AVERAGES.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
COLD FRONT HAS PUSHED EAST OF THE REGION THIS EVENING AND
DOWNSLOPING WESTERLY FLOW IN IT/S WAKE IS PRODUCING CLEARING SKIES
ACROSS PORTIONS OF THE SUSQ VALLEY. RESIDUAL LOW LVL MOISTURE
ASCENDING THE W MTNS WILL PRODUCE PERSISTENT MVFR STRATO-CU AT
BFD AND JST OVERNIGHT WITH SREF DATA EVEN SUGGESTING THE POSSIBILITY
OF CIGS DIPPING TO IFR LATE TONIGHT. A FEW SHRA NOTED ON RADAR
ACROSS WESTERN PA AT 21Z ASSOC WITH APPROACH OF UPPER LVL TROUGH.
THESE SHRA SHOULD BE CONFINED MAINLY THE W MTNS THIS EVENING.
WHERE SKIES REMAIN CLOUDY...ATMOS WILL REMAIN WELL MIXED AND FAVOR
FREQUENT WIND GUSTS TO NR 20KTS OVERNIGHT ACROSS THE W MTNS.
DOWNSLOPING FLOW EAST OF THE MTNS WILL RESULT IN BRKS IN THE
OVERCAST...SOME RAD COOLING AND LIGHTER WIND SPEEDS.
SOME EARLY LOW CIGS ARE POSSIBLE TO START TUESDAY. HOWEVER...HIGH
PRES BUILDING INTO THE STATE SUPPORTS A HIGH CONFIDENCE FCST OF
VFR CONDS EVERYWHERE BY MIDDAY.
OUTLOOK...
WED-EARLY THUR...NO SIG WX EXPECTED.
LATE THU-FRI...FROPA WITH RAIN/LOW CIGS POSSIBLE.
SAT...BREEZY WITH MVFR CIGS W...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...DANGELO/FITZGERALD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1243 PM CDT MON OCT 15 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
227 AM CDT MON OCT 15 2012
MAIN FORECAST CONCERN IS THE IMPACTS ON THE AREA FROM A DEEP UPPER
TROUGH DROPPING INTO THE NORTHERN PLAINS TUESDAY NIGHT.
CURRENTLY AS OF 07Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED NEARLY ZONAL FLOW ACROSS THE NORTHERN ROCKIES AND
SOUTHWEST CANADA...AND TROUGHING ACROSS THE WESTERN GREAT LAKES
REGION INTO ILLINOIS. THE FORECAST AREA LIES ON THE WESTERN SIDE
OF THIS TROUGHING...FAVORING SUBSIDENCE AND DRY AIR. 00Z SOUNDINGS
FROM ABR AND MPX REFLECT THESE ATTRIBUTES...WITH PRECIPITABLE
WATER VALUES NEAR 0.5 INCH. SATELLITE IMAGERY ALSO REFLECTS THE
DRY AIR WITH CLEARING ACROSS MUCH OF MINNESOTA AND IOWA. SOME
COOLER AIR TOO FLOWING IN ON THE BACK SIDE OF THE TROUGH WITH
850MB TEMPS OF 3C AT MPX AT 00Z. HOWEVER...WARMER READINGS OF
7-15C AT 850MB WERE OBSERVED IN THE DAKOTAS. AT THE SURFACE...A
RIDGE OF HIGH PRESSURE WAS PRESENT ACROSS WESTERN MINNESOTA WHILE
A NEW LOW PRESSURE SYSTEM WAS TAKING SHAPE ACROSS SOUTHERN
SASKATCHEWAN.
TODAY AND TONIGHT...FOCUS IS ON A COLLECTION OF SHORTWAVES IN THE
ZONAL FLOW OVER WASHINGTON. MODELS ARE IN GOOD AGREEMENT SENDING
THESE EAST INTO THE EASTERN DAKOTAS AND WESTERN MINNESOTA BY 12Z
TUESDAY. THERE EVEN APPEARS TO BE A WEAK TROUGH SIGNATURE IN THE
500MB HEIGHT FIELD AT 12Z WITH THESE SHORTWAVES. AS THESE SHORTWAVES
HEAD EAST...THEY WILL HELP PICK UP THE CURRENT SYSTEM IN SOUTH
CENTRAL SASKATCHEWAN...SENDING A TROUGH INTO MINNESOTA BY 12Z
TUESDAY. WARM ADVECTION AHEAD OF THIS SYSTEM WILL COMMENCE OVER THE
FORECAST AREA THIS AFTERNOON...WITH 850MB TEMPS TOPPING OUT BETWEEN
4-8C BY 00Z...WARMEST WEST. OTHER THAN SOME INCREASE IN WARM
ADVECTION HIGH AND PERHAPS MID CLOUDS AS WELL LATE IN THE DAY...
CURRENTLY OBSERVED CROSSING THE DAKOTAS...SHOULD SEE PLENTY OF SUN.
AS A RESULT...ANTICIPATING TEMPERATURES TO TOP OUT IN THE MID 50S TO
MID 60S. FOR TONIGHT...PLANNING ON THE MID AND HIGH CLOUDS TO
QUICKLY ENCOMPASS THE AREA...HELPING TO LIMIT TEMPERATURE FALL. IN
ADDITION...MODELS SHOW AN INCREASE OF 850MB MOISTURE TRANSPORT
THROUGH THE NIGHT AHEAD OF THE TROUGH COMING INTO MINNESOTA. NOSE OF
THIS MOISTURE TRANSPORT...AS WELL AS THE BULK OF ISENTROPIC LIFT...
APPEARS TO BE SITUATED MAINLY NORTH OF THE AREA. AS SUCH...EXPECTING
MOST PRECIPITATION TO STAY NORTH. HOWEVER...DID INTRODUCE A 20
PERCENT CHANCE IN TAYLOR COUNTY SINCE THEY LOOK TO BE RIGHT ON THE
EDGE OF WHERE THE WARM ADVECTION PRECIPITATION MAY EXIST. FOLLOWED A
BLEND OF GUIDANCE FOR LOWS.
TUESDAY...THE WEAK UPPER TROUGH SIGNATURE PRESENT OVER THE
EASTERN DAKOTAS AT 12Z TUESDAY IS FORECAST BY ALL MODELS TO CROSS
THE AREA ON TUESDAY. THE SAME QUESTIONS REMAIN IF THIS TROUGH CAN
PRODUCE PRECIPITATION AS IT MOVES THROUGH. THE 14.12Z ECMWF WAS MUCH
MORE IMPRESSIVE WITH QPF COMPARED TO ITS PREVIOUS RUN WITH MUCH OF
THE AREA AFFECTED. MEANWHILE THE 15.00Z NAM CONTINUES TO PAINT A
MOSTLY DRY SCENARIO OUTSIDE OF SOME LINGERING WARM ADVECTION PRECIP
OVER TAYLOR COUNTY IN THE MORNING. THE 15.00Z GFS LIES IN-BETWEEN
THE TWO SCENARIOS WITH QPF MAINLY IN THE MORNING ALONG AND NORTHEAST
OF I-94. THINKING THE ECMWF IS OVERDONE WITH THE AMOUNT OF QPF GIVEN
THE OVERALL LACK OF MOISTURE AVAILABILITY...ESPECIALLY IN THE LOWER
LEVELS. THEREFORE...HAVE STAYED CLOSE TO THE PREVIOUS FORECAST OF
20-30 PERCENT CHANCES ALONG AND NORTHEAST OF I-94. NEW 15.00Z ECMWF
HAS A LITTLE LESS QPF...AND FOCUSES ITS MAIN AREA SIMILAR TO WHERE
THE FORECAST HAS IT. TEMPERATURES ARE A BIT TRICKY ON TUESDAY AS
MUCH OF THE MORNING WILL LIKELY BE CLOUDY WITH MID AND HIGH CLOUDS
AROUND. AS THE TROUGH COMES THROUGH...THE OPPORTUNITY FOR CLEARING
EXISTS. 850MB TEMPS REALLY DO NOT COOL WITH THE TROUGH...HOVERING
BETWEEN 9C NORTH AND 13C SOUTH. HERE TOO WILL STAY PRETTY CLOSE TO
THE PREVIOUS FORECAST WITH HIGHS FROM THE MID 60S EAST (MOST CLOUDS)
TO LOW 70S WEST.
TUESDAY NIGHT...A VERY POTENT UPPER TROUGH IS PROGGED TO DIG DOWN
INTO MONTANA AND THE NORTHERN PLAINS BY 12Z WEDNESDAY. AS THIS
TROUGH DIGS IN...A COLD FRONT GETS SENT EASTWARD...PERHAPS REACHING
WESTERN PORTIONS OF THE FORECAST AREA BY 12Z WEDNESDAY. THE 15.00Z
GFS AND NAM...AS WELL AS THE 14.12Z/15.00Z ECMWF KEEP PRECIPITATION
NORTHWEST OF THE AREA THROUGH TUESDAY NIGHT. THIS SEEMS REASONABLE
GIVEN THAT THE BULK OF THE PRECIPITATION LOOKS TO OCCUR POST-FRONTAL
AND MORE ASSOCIATED WITH DPVA FROM THE POTENT TROUGH. AS SUCH...HAVE
REMOVED ANY LOW CHANCES OF PRECIPITATION IN FAR WESTERN PORTIONS OF
THE AREA. TEMPERATURES COULD DROP QUICKLY IN THE EVENING...
ESPECIALLY AT THE TYPICAL COLD SPOTS...WITH MOSTLY CLEAR SKIES AND A
BAGGY PRESSURE GRADIENT IN PLACE. INCREASING MID AND HIGH CLOUDS AS
WELL AS WINDS AHEAD OF THE FRONT AND UPPER TROUGH SHOULD HELP TO
HOLD TEMPERATURES STEADY OR EVEN RISE AFTER MIDNIGHT.
WEDNESDAY AND WEDNESDAY NIGHT...MODELS ARE IN REALLY GOOD AGREEMENT
THAT THE POTENT UPPER TROUGH WILL CONTINUE TO DIG SOUTHEASTWARD...
FULLY ENCOMPASSING THE AREA BY WEDNESDAY NIGHT. HOWEVER...THERE ARE
SOME IMPORTANT DETAILS WITHIN THE UPPER TROUGH THAT MODELS DIFFER
ON. THE FIRST IS WITH A SHORTWAVE EXTENDING SOUTH OF AN UPPER LOW
CONTAINED WITHIN THE TROUGH. THIS SHORTWAVE...PROGGED NEAR BISMARCK
NORTH DAKOTA AT 12Z WEDNESDAY...THE 15.00Z GFS IS MUCH FASTER THAN
ANY OTHER MODEL WITH IT BY BRINGING IT INTO THE FORECAST AREA BY
00Z. THE 15.00Z NAM/UKMET/CANADIAN/ECMWF ARE ALL SLOWER...ONLY
REACHING WESTERN MINNESOTA BY 00Z. THIS IS A SIGNIFICANT ISSUE AS
THE FASTER GFS WOULD NOT ALLOW AS MUCH MOISTURE RETURN FROM THE GULF
OF MEXICO TO COME UP INTO THE FORECAST AREA. THUS...THE GFS ENDS UP
AS A DRY SOLUTION. ALL THE OTHER MODELS PRODUCE PRECIPITATION ON
WEDNESDAY WHICH SEEMS REASONABLE. THUS...THE 60 PERCENT CHANCES ARE
STILL ON TRACK. WEDNESDAY NIGHT IS A LITTLE MORE UP IN THE AIR...
THOUGH. THINGS IN PLAY WITH PRECIPITATION CHANCES INCLUDE: TRACK OF
THE UPPER LOW WITHIN THE TROUGH...A POSSIBLE DRY SLOT...AND A TROWAL
AND COLD CONVEYOR BELT AREA WRAPPING AROUND THE UPPER LOW. THE
PMDHMD FROM HPC DISCUSSES THIS SITUATION WELL...WITH MODELS ALL OVER
THE PLACE WITH THESE FEATURES AND ALL PLAUSIBLE. THEREFORE...PLAN ON
TAKING A CONSENSUS APPROACH. AS THE PMDHMD STATES TOO...THE SYSTEM
RESPONSIBLE FOR THE POTENT UPPER TROUGH IS IN A DATA SPARSE REGION
OF THE NORTHERN/NORTHEAST PACIFIC. SO IT MAY TAKE AWHILE BEFORE
MODELS SETTLE DOWN ON A SOLUTION WITH THE VARIOUS FEATURES. THE
CONSENSUS APPROACH RESULTS IN 30 TO 50 PERCENT CHANCES...HIGHEST
ACROSS THE NORTH. ALSO FOLLOWED THE CONSENSUS APPROACH FOR
TEMPERATURES. SHOULD STILL BE NEAR NORMAL ON WEDNESDAY WITH THE WARM
ADVECTION AHEAD OF A SURFACE COLD FRONTAL PASSAGE. HOWEVER...
TEMPERATURES LOOK TO FALL IN THE AFTERNOON AS THE FRONT PASSES AND
RAIN DEVELOPS. IF A DEEP DRY SLOT ENTERS THE PICTURE WEDNESDAY
NIGHT...LOWS COULD BOTTOM OUT IN 30S. HOWEVER...WILL PLAY MORE
CLOUDS AND WIND TO KEEP LOWS IN THE 40S.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
227 AM CDT MON OCT 15 2012
15.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN FAIRLY GOOD
AGREEMENT ON HANDLING THE UPPER TROUGH AND ITS LIFT OUT NORTHEAST
AWAY FROM THE AREA. THE GFS AGAIN IS SLIGHTLY FAST...BUT ALL MODELS
AGREE THAT BY FRIDAY NIGHT...THE UPPER TROUGH WILL BE FAR ENOUGH
EAST OF THE AREA TO ALLOW CONDITIONS TO DRY OUT. UNTIL THEN...SAME
CONCERNS THAT WERE PRESENT ON WEDNESDAY NIGHT WITH POSITIONS OF THE
UPPER LOW IN THE TROUGH...DRY SLOT...TROWAL AND COLD CONVEYOR BELT
STILL PERSIST THROUGH FRIDAY. AS A RESULT...HAVE CONTINUED TO FOLLOW
A CONSENSUS APPROACH. HIGHEST CHANCES OF PRECIPITATION EXPECTED ON
THURSDAY SINCE THERE ARE INDICATIONS THAT THE TROUGH WILL FILL AFTER
THEN. COOL CONDITIONS ARE LIKELY TOO WITH THE UPPER TROUGH IN PLACE.
850MB TEMPS ARE ONLY PROGGED IN THE 0-2C RANGE. COMBINE THIS WITH
PRECIPITATION COULD END UP KEEPING HIGHS IN SOME LOCATIONS FROM EVEN
REACHING 50...ESPECIALLY ON THURSDAY.
FOR THE WEEKEND...MODELS ARE INDICATING THAT A POTENT UPPER TROUGH
WILL DROP SOUTH OUT OF THE GULF OF ALASKA AND AT LEAST INTO BRITISH
COLUMBIA. THE 14.12Z AND 15.00Z ECMWF RUNS AS WELL AS SOME OF THE
GFS ENSEMBLES TAKE IT ONE STEP FURTHER AND DIG THE TROUGH INTO THE
PACIFIC NORTHWEST. ALL SOLUTIONS THUS WOULD YIELD AT LEAST ZONAL
FLOW DOWNSTREAM INTO THE FORECAST AREA...RESULTING IN WARMING AND
DRY CONDITIONS. IN THE CASE OF THE ECMWF...RIDGING ENDS UP BUILDING
INTO THE FORECAST AREA. FOR NOW HAVE FOLLOWED THE CONSENSUS APPROACH
FOR TEMPERATURES GIVEN THE SPREAD IN HOW THE UPPER FLOW EVOLVES...
BUT SHOULD THE ECMWF VERIFY...TEMPERATURES MAY NEED TO BE INCREASED.
BY 18Z SUNDAY...THE ECMWF SUGGESTS 850MB TEMPS OF 10-14C...COMPARED
TO 4-8C FROM THE GFS.
&&
.AVIATION...THROUGH 18Z TUESDAY
1243 PM CDT MON OCT 15 2012
A WARM FRONT WILL MOVE SLOWLY EAST ACROSS THE AREA TONIGHT. HIGH
CLOUDS...MAINLY ABOVE 20K FEET...WILL ADVANCE INTO THE AREA THIS
AFTERNOON. THESE CLOUDS WILL LOWER TO AROUND 10K FEET BETWEEN
16.00Z AND 16.03Z...AND REMAIN THERE THROUGH TUESDAY MORNING.
THE LIGHT WINDS WILL SHIFT TO SOUTH AND CLIMB INTO THE 10 TO
15 KNOT RANGE THIS EVENING...AND CHANGE LITTLE FOR THE REMAINDER
OF THIS PERIOD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
227 AM CDT MON OCT 15 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1224 PM CDT MON OCT 15 2012
.UPDATE...A FEW CHANGES MADE TO THE TODAY FORECAST PERIOD. SFC HIGH
PRESSURE IN THE LOWER MISSISSIPPI VALLEY WILL STEADILY BUILD INTO
SOUTHERN WISCONSIN FROM THE SOUTH AS YESTERDAYS LOW PRESSURE SYSTEM
EXITS EAST. THE MAIN CONCERN...AND WHERE THE GREATEST CHANGES WERE
MADE...HAD TO DO WITH SKY GRIDS. A LOW-LEVEL CLOUD DECK...WITH CIGS
21 HFT TO 25 HFT...IS POSITIONED OVER THE FAR EASTERN SECTION OF THE
CWA AND DID NOT DISSIPATE/CLEAR OUT TO THE EAST AS PREVIOUSLY
THOUGHT THIS MORNING. VIS SAT TRENDS SHOW SOME SLIGHT MOVEMENT OF
THE DECK EAST...BUT IT IS NOT QUICK TO DO SO. IN ADDITION...THERE IS
SOME BREAKS ON THE FAR WESTERN EDGE OF IT. BUFKIT SOUNDINGS SHOW
THIS LOW-LEVEL MOISTURE REALLY WELL...IF NOT MAYBE OVER DONE IN
REGARD TO HOW LONG IT KEEPS IT IN. FURTHER...THE CLOUD DECK
CORRESPONDS WELL WITH RAP 925-850 MEAN RH FIELD.
GIVEN BUFKIT SOUNDINGS...MODEL RH...AND SAT TRENDS...EXPECT CLOUDS
TO DIMINISH GRADUALLY AND MOVE EAST OVER COURSE OF THE DAY. CLOUDS
SHOULD PERSIST INTO THE AFTERNOON IN THE FAR EAST. GIVEN CHANGES IN
SKY COVER...ALSO LOWERED HIGH TEMPERATURES WHERE THE DECK RESIDES
BY A FEW DEGREES.
.AVIATION/18Z TAFS/...AREA OF MVFR/VFR CEILINGS WITH CLOUD DECK
SHOULD LINGER THROUGH THE AFTERNOON AT THE EASTERN TAF SITES. THESE
CLOUDS SHOULD SLOWLY THIN OUT LATER THIS AFTERNOON OR EARLY THIS
EVENING...WITH THE LOSS OF BOTH DAYTIME HEATING AND THE MOIST LAYER
IN THE LOW LEVELS. NORTHWEST WINDS AROUND 10 KNOTS ARE EXPECTED
THROUGH 00Z TUESDAY.
VFR CONDITIONS ARE THEN EXPECTED TONIGHT AND TUESDAY. BROKEN TO
OVERCAST MIDDLE TO HIGH CLOUDS WILL MOVE SOUTHEAST INTO THE AREA
LATER THIS EVENING AND AFTER MIDNIGHT...AND LINGER THROUGH TUESDAY.
ANY LIGHT RAIN SHOWERS OR DRIZZLE SHOULD REMAIN NORTH OF TAF SITES.
WINDS WILL GRADUALLY INCREASE OUT OF THE SOUTH TONIGHT INTO
TUESDAY...WITH GUSTS OF 20 TO 25 KNOTS POSSIBLE TUESDAY AFTERNOON.
&&
.MARINE...WILL LET SMALL CRAFT ADVISORY EXPIRE AT 18Z ACROSS THE
NEARSHORE WATERS. CURRENT OBSERVATIONS ALONG AND NEAR THE SHORE ARE
ONLY GUSTING TO AROUND 15 KNOTS. THE MID LAKE BUOY STILL HAS SOME
GUSTS TO 25 KNOTS OCCURRING...WHICH MAY STILL BE OCCURRING TOWARD
THE OPEN WATERS. HOWEVER...WINDS SHOULD CONTINUE TO WEAKEN...AS
PRESSURE GRADIENT WEAKENS. AREA WEB CAMERAS SHOWING WAVES NON
EXISTENT NEAR THE SHORE...TO BE EXPECTED GIVEN THE OFFSHORE WINDS. 6
FOOT WAVES AT THE MID LAKE BUOY SUGGEST WAVES TOWARD THE OPEN WATERS
SHOULD BE IN THE 2 TO 4 FOOT RANGE.
.PREV DISCUSSION... /ISSUED 333 AM CDT MON OCT 15 2012/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
CLOUDS THE FIRST ISSUE AS THEY SLOWLY CLEAR FROM WEST TO EAST
ACROSS THE REMAINDER OF CWA WITH DEPARTING CYCLONIC FLOW AROUND
MID-UPPER LEVEL LOW...WHICH WAS NEAR SSM AT 06Z ON WATER VAPOR
LOOPS...AS IT LIFTS AWAY TO THE NORTHEAST.
CURRENT LOW LEVEL CLOUD DECK CLOSELY TIED TO 925-850 MB LAYER
RELATIVE HUMIDITY OF 80 PCT OR HIGHER...WHICH PUSHES EAST OF CWA
AT/AROUND 12Z TODAY. WILL KEEP AT LEAST PARTLY CLOUDY IN REGIONS ON
THE CYCLONIC SIDE OF 500 MB SHEARED VORTICITY AXIS UNTIL IT CLEARS
FORECAST AREA AROUND OR SHORTLY AFTER 18Z. MIXING UP TO 925 MB
TEMPERATURES THAT CLIMB TO AROUND +7C NORTHEAST TO +9C SOUTHWEST BY
00Z BRINGING MID 50S NORTHEAST...UPPER 50S MOST LOCATIONS...AND
AROUND 60 SOUTHWEST...WHICH IS IN GOOD AGREEMENT WITH CONSENSUS MOS
AND RAW TEMPERATURES.
MAINLY CLEAR SKIES AS WEAK RIDGING BUILDS IN FOR THE REST OF THE
AFTERNOON AND EVENING AHEAD OF THE NEXT SHORT WAVE TROUGH...WHICH
MOVES OUT INTO THE NORTHERN PLAINS THIS EVENING. THE MODELS HAVE
THE TROUGH AXIS REACHING A CONSENSUS POSITION FROM NORTHERN MINNESOTA
TO EASTERN NEBRASKA BY 12Z TUESDAY.
700-850MB WARM AIR ADVECTION BRINGS A MID-DECK BACK ACROSS THE
FORECAST AREA BETWEEN 06Z AND 12Z TUESDAY...BUT PRECIPITATION WILL
REMAIN NORTH OF CWA WITH BEST ISENTROPIC ADIABATIC OMEGA AND
FRONTOGENETIC FORCING ACROSS NORTHERN WISCONSIN. CLOUDS WILL HALT
TEMP FALL WITH LOWS BEING REACHED BETWEEN 06Z AND 09Z TUESDAY.
TUESDAY...FORECAST CONFIDENCE HIGH.
EXPECTING MILD AND CLOUDY CONDITIONS WITH BREEZY SOUTH WINDS. TEMPS
WARMING INTO THE LOWER/MID 60S IS CONSERVATIVE DUE TO THE EXPECTED
CLOUD COVER. STRAIGHT 925MB TEMPS WITH DRY ADIABATIC MIXING WOULD
SUGGEST MAX TEMPS IN THE LOWER 70. THERE COULD BE SOME WEAK
VORTICITY ADVECTION DUE TO A SHORTWAVE MOVING ACROSS...SO KEPT SMALL
POPS IN NORTHEAST FORECAST AREA. AMOUNTS SHOULD BE LIGHT OR NONE AT
ALL.
PRECIP CHANCES MOVE EAST OUT OF THE AREA TUE NIGHT WITH THE EXITING
SHORTWAVE. MID CLOUDS AND WARM AIR ADVECTION AHEAD OF THE NEXT UPPER
TROUGH WILL KEEP TEMPS MILD OVERNIGHT...WITH LOWS EXPECTED IN THE
UPPER 40S/LOWER 50S.
WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
AN UPPER LEVEL TROUGH WILL AMPLIFY AS A 120 KT JET STREAMS INTO THE
PLAINS FROM THE PACIFIC NORTHWEST ON WED. THE 500MB TROUGH WILL
DEVELOP INTO A CLOSED UPPER LOW AND MEANDER ACROSS MN AND WI THROUGH
THU NIGHT. THIS WILL BRING A ROUND OF MODERATE RAIN TO SOUTHERN WI
WITH THE LEADING COLD FRONT. GFS APPEARS TOO FAST WITH THE
FRONT...SO DISREGARDED ITS SOLUTION. ECMWF AND UKMET ARE THE SLOWEST
WITH THE NAM AND CANADIAN ARE SOMEWHERE IN BETWEEN. GENERALLY
COMPROMISED AND WENT WITH LIKELY POPS IN THE WESTERN FORECAST AREA
WED AFTERNOON THEN LIKELY IN THE EASTERN AREA WED EVENING.
IF THE SLOWER SOLUTION PANS OUT WITH PRECIP NOT SPREADING INTO
FORECAST AREA UNTIL WED EVE...THEN MAX TEMPS WILL BE HIGHER THAN
WHAT I HAVE IN THERE. WAS COUNTING ON CLOUDS AND PRECIP TO KEEP THE
TEMPS DOWN.
SOME MODELS DRY SLOT SOUTHERN WI ON THU AS THE LOW OCCLUDES WHILE
OTHERS HAVE US IN A BULLSEYE OF PRECIP. WENT WITH MODEL CONSENSUS OF
CHANCE POPS FOR NOW. AS HPC STATES...WE WILL HAVE TO WAIT UNTIL TUE
WHEN THIS UPPER TROUGH/JET REACH THE CONTINENTAL NORTHWEST AND
MODELS CAN RESOLVE THE DATA BETTER.
LONG TERM...
SATURDAY THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM TO LOW.
DISREGARDING PRECIP CHANCES IN THE GFS MODEL SOLUTION ON SAT AS AIR
SHOULD BE TOO DRY DESPITE THE WARM AIR ADVECTION AND SHORTWAVE
MOVING ACROSS THE REGION. THE ECMWF IS NOW QUICKER WITH MOVING THAT
UPPER LOW OUT EAST...CLOSER TO THE GFS SOLUTION. THIS MEANS DRY
WEATHER ON SATURDAY.
MAJOR UPPER LEVEL MODEL DIFFERENCES FOR LATER IN THE WEEKEND AS THE
GFS GOES ZONAL AND THE ECMWF DEVELOPS ANOTHER BIG TROUGH. GFS
SUGGESTS COOL RAIN AND ECMWF SUGGESTS DRY AND WARM RIDGING.
AVIATION/12Z TAFS/...
REMAINING MVFR CLOUD DECK SHOULD BE OUT OF EASTERN TAF SITES BY
12Z...WITH A MID-DECK LINGERING UNTIL AT LEAST MID MORNING WHEN
CYCLONIC FLOW SHOULD BE LIFTING AWAY FROM FORECAST AREA. VFR
CONDITIONS FOR THE REMAINDER OF THE FORECAST...WITH WARM AIR
ADVECTION CLOUDS AT OR ABOVE 8K FT OVERSPREADING THE REGION FROM
WEST TO EAST BETWEEN 06Z AND 09Z TUESDAY.
MARINE...
WILL LEAVE SMALL CRAFT ADVISORY END TIME AS IS...WITH SOUNDINGS
SHOWING POTENTIAL FOR FREQUENT GUSTS OVER THE WATER UNTIL AT LEAST
15Z. NEXT SHIFT MAY BE ABLE TO DROP EARLY IF GRADIENT SLACKENS
SOONER THAN EXPECTED WITH SURFACE RIDGE BUILDING IN. TIGHTENING
GRADIENT AHEAD OF NEXT LOW PRESSURE AREA MOVING TOWARD THE WESTERN
GREAT LAKES MAY REQUIRE ANOTHER ADVISORY FOR TUESDAY AFTERNOON AND
EVENING FOR GUSTY SOUTH TO SOUTHWEST WINDS. GFS WINDS STRONGER THAN
NAM...ECMWF OR GEM BUT ALL SHOW THE POTENTIAL FOR ADVISORY LEVEL
WINDS. WILL MENTION POSSIBLE NEED FOR A SMALL CRAFT AND LET NEXT
SHIFT ASSESS NEXT MODEL RUNS FOR TIMING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR
LMZ643>646.
&&
$$
UPDATE...WOOD/ET
TODAY/TONIGHT AND AVIATION/MARINE...REM
TUESDAY THROUGH SUNDAY...MRC