Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/29/13
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1048 AM MDT FRI SEP 27 2013
.UPDATE...
ISSUED AT 1045 AM MDT FRI SEP 27 2013
THE EASTERN UINTA MTNS AUTOMATED TOWARDS REPORT 2-3 INCHES WITH
INSTABILITY PRODUCING THUNDERSTORMS THIS MORNING. THE UNSTABLE
COLD CORE WILL WORK THROUGH THE REGION THIS AFTERNOON.
THE COLD FRONT IS MARCHING TOWARDS THE CONTINENTAL DIVIDE THIS
LATE MORNING WITH WIDESPREAD SHOWERS ALONG IT. SNOW LEVELS ARE
DROPPING FROM ABOVE 10KFT TO AROUND 8KFT BEHIND THE FRONT. CAMS ON
INDEPENDENCE AND MONARCH PASSES SHOW GOOD ACCUMULATIONS FOR
SEPTEMBER AND THE LATEST RAP AND HRRR PRODUCE SNOW THERE AT LEAST
UNTIL 04Z. SO HAVE HOISTED A WINTER WEATHER ADVISORY FOR ZONES
9/10/12. ZONE 9/ GRAND MESA THE BEST SNOW ACCUMULATIONS THERE
EXPECTED TO BE EAST OF HIGHWAY 65. ALL MTN ZONES IN ZONE 10 SHOULD
DO WELL WITH SNOW STICKING TO THE PASS HIGHWAYS THROUGH THE
AFTERNOON AND EVENING MAKING FOR SLICK DRIVING CONDITIONS. ZONE 12
SHOULD SEE THE BEST SNOW OVER ITS NORTHERN RIDGE INCLUDING MCCLURE
PASS...BUT ALSO COTTONWOOD AND MONARCH WILL SEE ACCUMULATING
HAZARD SNOW.
SNOW EXPECTED TO END IN THE EASTERN UTAH BEFORE SUNSET AND THE
EASTERN PORTION OF THE CWA BY MIDNIGHT. COLD TEMPERATURES WILL
SETTLE OVER THE REGION AND THE MAJORITY OF THE FREEZE WATCHES
WILL LIKELY BE CONVERTED TO WARNINGS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 434 AM MDT FRI SEP 27 2013
AS OF 09Z...THE COLD FRONT ASSOCIATED WITH THE SHARP UPPER LEVEL
TROUGH WEST OF THE FORECAST AREA WAS ALONG A KCEZ-KCAG-KRWL LINE.
A BROAD SWATH OF SHOWERS COVERED MUCH OF THE REGION 60 MILES ON
EITHER SIDE OF THIS LINE. SOME SNOW EVIDENT IN THE TROUT CREEK AND
HICKERSON PARK SNOTELS WHERE AN ESTIMATED 1 AND 2 INCHES OF SNOW
WAS RECORDED. THESE SITES ARE AT AN ELEVATION OF 9400 AND 9100
FEET RESPECTIVELY. NO EVIDENCE OF SNOW IN THE HIGHER ELEVATIONS
AHEAD OF THE FRONT WHICH WAS EXPECTED AS SNOW LEVELS GENERALLY
ABOVE 10000 FEET AND SHOWERS WERE JUST MOVING INTO THE HIGHER
RANGES.
MODELS SLOWLY SHIFT THE MID-LEVEL TROUGH AXIS EASTWARD ACROSS UTAH
DURING THE DAY WITH THE 5H AXIS OVER WESTERN COLORADO BY DAYS END.
THE COLD FRONT DRIVEN ALONG AHEAD OF THE TROUGH WILL REACH THE
DIVIDE NEAR MIDDAY...THEN PUSH ONTO THE EASTERN PLAINS DURING THE
AFTERNOON. UPWARD FORCING FROM THE SURFACE TO THE JET LEVEL
CONSIDERABLE THROUGHOUT THE DAY WHICH SHOULD BRING WIDESPREAD
PRECIPITATION TO THE COLORADO MOUNTAINS. EASTERN UINTA MOUNTAINS
ALSO FAVORED AS FLOW BECOMES NORTHWESTERLY BEHIND THE TROUGH
ESTABLISHING AN OROGRAPHIC COMPONENT OF LIFT TO WANING UPPER LEVEL
DYNAMIC FORCING. HERE SNOW LEVELS DROP TO NEAR THE MOUNTAIN/S BASE
IN RESPONSE TO POST-FRONTAL ADVECTION OF COLDER AIR. MODELS STILL
SUPPORT DECENT ACCUMULATIONS SO WILL CONTINUE WITH EARLY SEASON
WINTER STORM WARNING. REALLY STRUGGLED WITH THE QUESTION OF
WHETHER TO EXPAND WINTER WEATHER ADVISORIES TO OTHER RANGES OF
THE COLORADO MOUNTAINS. IN THE END...FELT SNOW LEVELS WILL LOWER
TOO LATE TO BRING SIGNIFICANT SNOWFALL TO THE HIGHER PASSES BY
DAYS END. SHOWER ACTIVITY WILL BE FAIRLY WIDESPREAD SO NOT A
QUESTION OF QPF TODAY. SINCE SNOW LEVELS CAN BE TRICKY EARLY IN
THE SEASON WILL SUGGEST THE DAY SHIFT MONITOR SNOWFALL CLOSELY.
ELSEWHERE...A BIT OF A DRY SLOT OVER SOUTHEAST UTAH SO KEPT POPS
LOW OVER THIS AREA. TEMPERATURES MARKEDLY COOLER TODAY WITH THE
COLD FRONT THROUGH MUCH OF THE FORECAST BY MIDDAY. SHOWERS AND
CLOUDS WILL ALSO SUPPRESS HIGHS AS INDICATED IN PREVIOUS FORECAST.
WITH STRONG COLD AIR ADVECTION FROM THE NORTHWEST...DRY AND COLD AIR
BUILDS IN BEHIND THE FRONT FROM THE WEST FRI NIGHT AFTER SHOWERS
TAPER OFF IN THE EVENING. SOME LIGHT PRECIP OVER THE NORTHERN CO
MTNS AND ALONG THE CENTRAL DIVIDE WILL LINGER THROUGH FRI
EVENING...LIKELY IN THE FORM OF SNOW ABOVE 6500 FT IN NORTHERN
AREAS. OTHERWISE...SKIES WILL BE CLEARING WITH THE COLDEST LOW
TEMPERATURES OF THE SEASON SO FAR OVERNIGHT INTO SATURDAY. THERE
IS A GOOD POTENTIAL FOR A FROST OR FREEZE IN MANY VALLEYS BY
SUNRISE SATURDAY. 00Z GUIDANCE SHOWS EVEN COOLER MIN TEMP GUIDANCE
IN THE VALLEYS THAN THE PREVIOUS 12Z AND 18Z MODELS. THE FREEZE
WATCH CONTINUES FOR MOST OF WESTERN CO VALLEYS AND THE EASTERN
UINTA BASIN. IN THE GRAND VALLEY...LOWS OF 30-35 DEGREES BUT WITH
POCKETS OF UPPER 20S IN THE NORMALLY COLDER SPOTS LOOK POSSIBLE.
AFTER A COLD MORNING SATURDAY...A DRY AND CALMER ZONAL FLOW WILL
KEEP TEMPERATURES 5-10 DEGREES BELOW NORMAL.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 434 AM MDT FRI SEP 27 2013
TEMPERATURES WILL BEGIN TO CLIMB TO NEAR NORMAL BY SUNDAY WITH THE
HELP OF A SOUTHWESTERLY WIND COMPONENT AND ENHANCED WINDS ALONG THE
NORTHERN UT/CO BORDER.
SUNDAY NIGHT TO THURSDAY...FLAT ZONAL FLOW PREDOMINATES THROUGH
THE MIDDLE OF THE COMING WEEK. AS A RESULT...EXPECT DRY AND MILD
CONDITIONS THROUGH WEDNESDAY WITH A WARMING TREND RETURNING
TEMPERATURES TO NEAR NORMAL BY MONDAY. THE NEXT SYSTEM TO AFFECT
THE AREA MAY ARRIVE AS EARLY AS THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1045 AM MDT FRI SEP 27 2013
WIDESPREAD PRECIPITATION WITH A FEW EMBEDDED THUNDERSTORMS OVER
WESTERN COLORADO AND NORTHEAST UTAH WILL AT TIMES RESULT IN MVFR
VSBY AND/OR CIGS TO AIRPORTS WITHIN THOSE AREAS THROUGH
00Z/SATURDAY. MOUNTAIN OBSCURATIONS WILL BE COMMON...WITH SNOW
LEVELS DROPPING TO 8000-8500 FEET MSL TONIGHT. ELSEWHERE...EXPECT
VFR CONDITIONS ACROSS SOUTHEAST UTAH OVER THE NEXT 24 HOURS.
CONDITIONS IMPROVE TONIGHT...THOUGH LOW CLOUDS WILL RESULT IN AREAS
OF MOUNTAIN OBSCURATION THROUGH 12Z SATURDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
COZ001-002-006>008-011-020>023.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR COZ009-
010-012-013.
UT...FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR
UTZ024.
WINTER STORM WARNING UNTIL 6 PM MDT THIS EVENING FOR UTZ023.
&&
$$
UPDATE...JOE
SHORT TERM...NL/JM
LONG TERM...JM/NL
AVIATION...EH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1017 PM CDT SAT SEP 28 2013
.DISCUSSION...
730 PM CDT
THE FORECAST HAD BEEN UPDATED TO SLOW THE EASTWARD PROGRESS OF
POPS AND TO DIMINISH THEM SOME...THOUGH STILL THINK MOST AREAS WILL
SEE AT LEAST SOME LIGHT RAIN TONIGHT. ALSO DIMINISHED THE TIMING OF
THE WINDOW OF SLIGHT CHANCE OF THUNDER.
THE GOES WATER VAPOR LOOP EARLY THIS EVE DEPICTS THE WELL-
DEVELOPED AUTUMN UPPER LOW LIFTING NORTHEAST OVER WESTERN QUEBEC.
A DEEP BUT NARROW-IN-WIDTH MOIST PLUME EXTENDS FROM TX THROUGH WI
ASSOCIATED WITH THIS. THE 00Z DVN RAOB INDICATED 1.66 IN OF
PWAT...WHICH LIKELY REFLECTS THE UPPER MAGNITUDE AGAIN THAT IS IN
AN EVEN NARROWER AXIS. THERE IS A DISJOINT IN BEST DYNAMICS AND
MOISTURE TRANSPORT/MAGNITUDES WITH THIS SYSTEM OVER THE IMMEDIATE
REGION NOW AND THAT IS LEADING TO MAINLY LIGHT PRECIP COVERAGE
AND INTENSITY...AND EXPECT THIS TO CONTINUE THROUGH 9-11 PM OR SO.
THE BEST UPPER DIFLUENCE IS CURRENTLY OVER WI AND NORTHWARD WHERE
BETTER SHOWER COVERAGE EXISTS...WHILE ANOTHER SHEARED WAVE AND
FOCUSED RIGHT ENTRANCE REGION OF THE UPPER JET IS MOVING NORTHEAST
FROM MO. HAVE BEGUN TO SEE AN UPTICK IN PRECIP WITH THIS FEATURE
ACROSS PARTS OF WEST CENTRAL IL. THE SURFACE FRONT ITSELF IS
LOCATED FROM MADISON WI TO NEAR GALESBURG AND MOVING SLOWLY
EAST...WITH POST FRONTAL FORCING /F-GEN AND SOME ELEVATED
INSTABILITY/ ALLOWING FOR SHOWERS EVEN BEHIND THIS.
AS THE SHEARED WAVE FROM MO TRANSLATES NORTHEAST AND IN TANDEM
WITH A MORE PRONOUN ED LLJ/MOISTURE TRANSPORT...DO ANTICIPATE THE
INCREASE IN SHOWER COVERAGE THAT HAS BEEN ADVERTISED TO MOVE
NORTHEAST. IT LOOKS TO MAINLY BE CONFINED TO EAST OF IL HIGHWAY
47...AND IT IS POSSIBLE IT ENDS UP EVEN BEING FURTHER EAST. THIS
SOMEWHAT MORE STEADIER RAIN/SHOWER ACTIVITY THAT IS FORECAST SHOULD
BE FAIRLY NARROW...SO TRIED TO TIME THAT FOCUS FOR THE HIGHEST
/CATEGORICAL/ POPS. THE NORTH AMERICAN RAPID REFRESH ENSEMBLE
SYSTEM /NARRE-TL/ REALLY HAS A GOOD HANDLE ON WHAT IS HAPPENING
AND WHAT IS EXPECTED TO UNFOLD...AND DOES SHOW A VERY NARROW AXIS
OF HIGHER POPS. BEFORE THAT...MAINLY SOME SPOTTY LIGHT RAIN OR
EVEN DRIZZLE IMMEDIATE AHEAD OF THE FRONT IS FAVORED. ALSO BEHIND
THE FRONT EXPECT THAT SHOWER ACTIVITY SHOULD CONTINUE ALONG THE
MID- LEVEL BAROCLINIC ZONE AND POTENTIALLY INCREASE IN COVERAGE AS
THIS FURTHER TIGHTENS WITH THE UPPER JET RIDGING PARALLEL TO IT.
SO KEEP LIKELY POPS AN HOUR OR TWO BEHIND THE FRONT BUT MENTION
MAINLY LIGHT INTENSITY. OVERALL NONE OF THIS POINTS TOWARD GREAT
THUNDER CHANCES AND HAVE DIMINISHED COVERAGE AND TIMING. NO
LIGHTNING STRIKES SEEN ANYWHERE NEAR THE AREA THE PAST SEVERAL
HOURS.
TEMPERATURE TRENDS LOOK GOOD AND HAVE JUST ADJUSTED/NUDGED TO NEAR
TERM FRONTAL POSITION.
MTF
//PREV DISCUSSION...
254 PM CDT
MAIN CONCERNS TODAY REVOLVE AROUND TIMING PRECIPITATION ASSOCIATED
WITH A COLD FRONT SWEEPING ACROSS THE REGION THIS EVENING.
THIS EVENING AND TONIGHT...
A COLD FRONT SPANS FROM THE ARROWHEAD OF MINNESOTA SOUTH INTO
EASTERN IOWA THIS AFTERNOON WITH PRECIP GENERALLY OCCURRING ALONG
AND JUST AHEAD OF THIS SYSTEM. LIGHTNING ACTIVITY WAS CONFINED
MAINLY TO MISSOURI...BUT HAS REALLY DISSIPATED OVER THE PAST FEW
HOURS. LATEST RAP GUIDANCE DOES INDICATE POTENTIALLY A LITTLE MORE
ROBUST INSTABILITY THAN PREVIOUSLY THOUGHT THOUGH...AND ACCAS OVER THE
AREA THIS MORNING WOULD ALSO SUGGEST THE PRESENCE OF SOME MID LEVEL
INSTABILITY...SO WILL MAINTAIN AT LEAST A SLIGHT CHANCE MENTION FOR
THUNDERSTORMS TODAY THOUGH MAINLY EXPECT RAIN WITH A FEW EMBEDDED
MODERATE SHOWERS. WHILE THERMODYNAMICALLY UNIMPRESSIVE...DYNAMIC
FORCING THIS EVENT CONTINUES TO LEAD TO HIGH CONFIDENCE IN THE
ENTIRE CWA SEEING WETTING RAINS THIS EVENING. WATER VAPOR IMAGERY
SHOWS A WELL DEFINED NEGATIVELY TILTED VORT MAX LIFTING ACROSS THE
UPPER MIDWEST WITH DEEP MOISTURE EXTENDING SOUTH ALONG THE FRONT.
PWATS COULD BE PUSHING 2 INCHES ALONG THE FRONT AS IT SWEEPS ACROSS
THE REGION TONIGHT. WHILE THE BEST UPPER LEVEL FORCING LIES NORTH OF
THE AREA...STILL EXPECT DECENT HEIGHT FALLS TO SPREAD OVER NORTHERN
ILLINOIS...ESPECIALLY LATE THIS EVENING. NAM/GFS INDICATE COUPLED
JET WITH THE BEST AREA OF DIVERGENCE ALOFT MOVING DIRECTLY OVERHEAD
THIS EVENING. THESE COUPLED WITH THE STRONG LOW LEVEL CONVERGENCE
ALONG THE FRONT SHOULD LEAD TO A DEEP VERTICAL RESPONSE...WITH
ACTIVITY ALONG THE FRONT INCREASING IN COVERAGE/INTENSITY LATE THIS
EVENING AS THE FRONT MOVES ACROSS THE CENTRAL AND EASTERN PORTIONS
OF THE CWA.
SUNDAY THROUGH TUESDAY...
FLAT RIDGING WILL BUILD OVER THE LOCAL AREA THROUGH THIS PERIOD WITH
THE MAIN JET STREAM SETTING UP FROM THE PACIFIC NORTHWEST INTO THE
NORTHERN GREAT LAKES...RESULTING IN DRY WEATHER WITH PRECIP CHANCES
STAYING NORTH OF THE AREA. AT THE SURFACE...HIGH PRESSURE WILL BUILD
IN BEHIND THE DEPARTING COLD FRONT SUNDAY. NORTH/NORTHEAST WINDS
SUNDAY WILL KEEP CONDITIONS QUITE A BIT COOLER NEAR THE LAKE FRONT
SUNDAY...LIKELY IN THE MID 60S...BUT TEMPERATURES FARTHER INLAND
SHOULD BE ABLE TO RISE INTO THE LOW TO MID 70S. CLEAR SKIES AND CALM
WINDS UNDER THE RIDGE AXIS SUNDAY NIGHT WILL ALLOW TEMPERATURES TO
EFFECTIVELY RADIATE WITH OVERNIGHT LOWS EXPECTED IN THE LOW TO MID
40S OUTSIDE OF URBAN HEAT ISLAND OF CHICAGO...WHICH IS EXPECTED TO
STAY PROPPED INTO THE MID 50S. WOULDNT BE SURPRISED IF SOME OF THE
TYPICAL COLD SPOTS DIP INTO THE 30S. WILL HAVE TO KEEP AN EYE ON FOG
SUNDAY NIGHT...BUT FOR NOW GUIDANCE SUGGESTS THAT DEW POINTS MAY BE
TOO DRY FOR WIDESPREAD FOG DEVELOP. WITH RECENT RAINFALL
THOUGH...NOT CONFIDENT THAT MODELS ARE HANDLING LOW LEVEL MOISTURE
VERY WELL. WILL INCLUDE MENTION FOR PATCHY FOG OUTSIDE THE METRO
AREA.
WITH THE RIDGE AXIS GRADUALLY SHIFTING EAST OF THE AREA
ON MONDAY...RETURN FLOW WILL LEAD TO A WARMING TREND WITH MID TO
UPPER 70S MONDAY...AND 80S POSSIBLE AGAIN BY TUESDAY. GFS/EMCWF BOTH
SHOW THERMAL RIDGE LEANING OVER THE REGION TUESDAY WITH H85 TEMPS A
LITTLE WARMER THAN TODAY IN THE 16-18C RANGE...THOUGH IF RECENT
MODEL PERFORMANCE IS ANY INDICATOR...THIS MAY BE A BIT TOO WARM.
EVEN TAKING A CONSERVATIVE APPROACH...GUIDANCE APPEARS TO BE A BIT
ON THE COOL SIDE SO WILL MAINTAIN THE WARMER FORECAST OF LOW TO MID
80S.
WEDNESDAY THROUGH SATURDAY...
MODELS IN DECENT AGREEMENT THROUGH WEDNESDAY...WITH THE DEVELOPMENT
OF A DEEP TROUGH OVER THE WEST COAST WEDNESDAY NIGHT...THEN BEGIN TO
DIVERGE WITH TIMING/STRENGTH INTO THE WEEKEND. THE UPPER TROUGH IS
EXPECTED TO PROGRESS EAST ACROSS THE ROCKIES...WITH SURFACE LOW
DEVELOPING OVER THE PLAINS AND A WARM FRONT LIFTING NORTH ACROSS THE
LOCAL AREA. TIMING IS THE MAIN ISSUE. THE GFS IS FASTEST...FOLLOWED
BY THE ECMWF AND THEN THE GFS ENSEMBLE MEAN. A SPAGHETTI PLOT OF
GEFS MEMBERS SHOWING SIGNIFICANT SPREAD BY FRIDAY EVENING...WITH THE
MOST PROGRESSIVE MEMBER SHOWING THE TROUGH AXIS NEARING THE
MISSISSIPPI VALLEY BY FRIDAY EVENING...WHILE SLOWEST MEMBERS HAVE A
DEEPER CLOSED LOW STILL OVER THE INTERMOUNTAIN WEST. ALL THIS BOILS
DOWN TO VERY LOW CONFIDENCE IN THE EXTENDED...THUS MAINTAINED A
BLENDED MODEL SOLUTION IN THE EXTENDED FORECAST...UNTIL DETAILS
START TO BECOME MORE CLEAR.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* BAND OF RAIN APPROACHING...BRIEF IFR/MVFR VSBY POSSIBLE.
* MVFR CIGS APPROACHING NEXT 1-2 HRS...THEN CLEARING TOWARD 08/09Z.
* SOUTHWEST WINDS WITH OCCASIONAL GUSTS TO AROUND 20 KT TURNING
NORTHWEST WITH COLD FRONTAL PASSAGE TOWARD 07Z.
MDB
//DISCUSSION...UPDATED 03Z...
COLD FRONT HAS MOVED THROUGH RFD AND WILL WORK ACROSS THE
REMAINING SITES INTO THE EARLY OVERNIGHT HOURS. RAIN HAS SLOWLY
EXPANDED IN COVERAGE TO THE WEST AND SOUTHWEST OF THE CHICAGO
METRO TERMINALS AND CONTINUES TO DO SO...REACHING THE CHI
TERMINALS IN THE NEXT 1-2 HRS. WITH A RATHER MOIST AIRMASS IN
PLACE BRIEF DOWNPOURS ARE LIKELY BRINGING VSBY DOWN TO 2-3 MILES
OR SO AS HAS BEEN OBSERVED TO THE SOUTHWEST OF THE AREA RECENTLY.
MVFR CIGS ARE ALSO WORKING THEIR WAY EASTWARD WITH THEIR BACK EDGE
JUST EAST OF THE MISSISSIPPI RIVER. MAY NEED TO SPEED UP ARRIVAL
OF CLEARING WITH NEXT TAF UPDATE.
MDB
FROM 00Z...
COLD FRONT MAKING EASTWARD PROGRESS INTO NW IL AT 00Z. BAND OF
LIGHT RAIN/SPRINKLES CONTINUES TO MOVE EAST AS WELL AND IS WORKING
INTO THE CHICAGO METRO. NEW RAIN DEVELOPMENT IS UNDERWAY IN A
NARROW BAND SOUTHWEST OF THE TERMINALS NEAR KUIN AND FURTHER
DEVELOPMENT IS EXPECTED AS UPPER LEVEL SUPPORT INCREASES. EXPECT
THAT THE CURRENT BAND OF LIGHT RAIN WILL CONTINUE ACROSS THE AREA
BUT THERE MAY BE A SLIGHT UPTICK IN COVERAGE/INTENSITY AS IT DOES
SO SO WILL MAINTAIN -SHRA MENTION EARLY THIS EVENING AT
ORD/MDW/DPA/GYY WITH THE EXPANDING PRECIP TO THE SW ARRIVING LATER
THIS EVENING. AREA OF MVFR CIGS IS ALSO APPROACHING FROM THE WEST
AND SHOULD ARRIVE BY MID EVENING ACROSS THE CHI AREA AND SHORTLY
AT RFD. THERE ALSO APPEARS TO BE A VERY NARROW BAND OF DRIZZLE
WITH 2-3SM VSBY NEAR RFD NOW AND IT IS NOT CLEAR THAT THIS WILL
TRANSLATE MUCH FURTHER EASTWARD SO WILL NEED TO MONITOR. ASSUMING
THE RAIN TO THE SOUTHWEST DOES INCREASE IN COVERAGE AND ARRIVE
LATE EVENING THEN BRIEF/IFR/MVFR VSBY IS POSSIBLE. CIGS WILL ALSO
LOWER TO LOW END MVFR IF NOT BRIEF IFR WITH THE RAIN AND RIGHT
AHEAD OF THE FRONT. SLOWED TIMING OF FRONTAL PASSAGE AND RESULTANT
SHIFT TO NORTHWEST SLIGHTLY. EXPECT THAT LOWER END MVFR CIGS WILL
LINGER FOR A FEW HOURS AFTER THE FRONT PASSES AS WILL SCATTERED
SHOWERS. CLEARING IS EXPECTED OVERNIGHT WITH WINDS DIMINISHING A
BIT AS WELL. VFR IS EXPECTED FOR SUNDAY WITH A FEW CUMULUS
POSSIBLE. NORTH-NORTHWEST WINDS WILL CONTINUE BUT SHOULD TURN
NORTHEAST ACROSS THE CHICAGO METRO DURING THE AFTERNOON. HIGH
PRESSURE WILL PASS RIGHT OVER THE AREA SUNDAY EVENING ALLOWING
WINDS TO TURN SOUTHEASTERLY OR BECOME CALM/LIGHT AND VARIABLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN BAND OF RAIN CROSSING THE AREA NEXT FEW
HOURS.
* HIGH CONFIDENCE IN MVFR CIGS OCCURRING...MEDIUM-HIGH CONFIDENCE
IN ARRIVAL TIME...MEDIUM CONFIDENCE IN DURATION/DEPARTURE TIME.
* HIGH CONFIDENCE IN WINDS SHIFTING NORTHWEST WITH FRONTAL PASSAGE
AND TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH WEDNESDAY...VFR.
THURSDAY AND FRIDAY...CHANCE SHRA/TSRA.
MDB
&&
.MARINE...
220 PM CDT
HIGH PRESSURE IS OVER NEW ENGLAND WHILE A LOW IS OVER NORTHERN
MINNESOTA/SOUTHWEST ONTARIO. WINDS HAVE STRUGGLED TO STRENGTHEN
OVER THE LAKE TODAY...BUT ARE FINALLY STARTING TO PICK UP. WILL
KEEP THE SMALL CRAFT ADVISORY GOING AND END IT AT 7PM TONIGHT AS
PLANNED. THE HIGH SLOWLY SHIFTS OFF THE NE ATLANTIC COAST WHILE THE
LOW REACHES HUDSON BAY TOMORROW. GUIDANCE IS STILL SUGGESTING WINDS
WILL PICK UP TO 30KT THIS EVENING OVER THE NORTH HALF TO THE LAKE.
IN ADDITION...SOUNDINGS STILL INDICATE THAT GALE FORCE GUSTS LIE
JUST 200 FT ABOVE THE SURFACE. WILL KEEP OCNL GALE FORCE GUSTS GOING
THROUGH 03Z AND HIGHER VESSELS WILL PROBABLY ENCOUNTER MORE THAN
JUST OCNL GALE FORCE GUSTS.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE LATE THIS EVENING WITH NW
WINDS 15-20 KT BEHIND IT. A WEAK SURFACE RIDGE MOVES OVER THE LAKE
TOMORROW AND WINDS QUICKLY DIMINISH. THE HIGH PUSHES EAST WITH
SOUTH WINDS EXPECTED ACROSS THE LAKE MONDAY AND TUESDAY. ANOTHER
LOW PASSES OVER THE SOUTHERN CANADIAN PRAIRIES EARLY NEXT WEEK...AND
EXPECTING THE PRESSURE GRADIENT TO TIGHTEN OVER THE NORTHERN HALF OF
THE LAKE. THEREFORE...HAVE 30KT WINDS OVER THE NORTHERN HALF OF THE
LAKE MONDAY NIGHT AND TUESDAY. WINDS TURN WEST AS THE LOW PUSHES
EAST AND ANOTHER WEAK SURFACE RIDGE SETS UP OVER THE LAKE.
LATE NEXT WEEK STILL LOOKS INTERESTING WITH A LARGE LOW CROSSING THE
PLAINS AND PASSING OVER LAKE SUPERIOR. MODEL TIMING IS NOT
CONSISTENT BETWEEN THE MODELS AND MODEL RUNS. THAT BEING SAID
GUIDANCE IS STILL SUGGESTING STRONG SOUTH WINDS LATE NEXT WEEK AHEAD
OF THE LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
733 PM CDT SAT SEP 28 2013
.DISCUSSION...
730 PM CDT
THE FORECAST HAD BEEN UPDATED TO SLOW THE EASTWARD PROGRESS OF
POPS AND TO DIMINISH THEM SOME...THOUGH STILL THINK MOST AREAS WILL
SEE AT LEAST SOME LIGHT RAIN TONIGHT. ALSO DIMINISHED THE TIMING OF
THE WINDOW OF SLIGHT CHANCE OF THUNDER.
THE GOES WATER VAPOR LOOP EARLY THIS EVE DEPICTS THE WELL-
DEVELOPED AUTUMN UPPER LOW LIFTING NORTHEAST OVER WESTERN QUEBEC.
A DEEP BUT NARROW-IN-WIDTH MOIST PLUME EXTENDS FROM TX THROUGH WI
ASSOCIATED WITH THIS. THE 00Z DVN RAOB INDICATED 1.66 IN OF
PWAT...WHICH LIKELY REFLECTS THE UPPER MAGNITUDE AGAIN THAT IS IN
AN EVEN NARROWER AXIS. THERE IS A DISJOINT IN BEST DYNAMICS AND
MOISTURE TRANSPORT/MAGNITUDES WITH THIS SYSTEM OVER THE IMMEDIATE
REGION NOW AND THAT IS LEADING TO MAINLY LIGHT PRECIP COVERAGE
AND INTENSITY...AND EXPECT THIS TO CONTINUE THROUGH 9-11 PM OR SO.
THE BEST UPPER DIFLUENCE IS CURRENTLY OVER WI AND NORTHWARD WHERE
BETTER SHOWER COVERAGE EXISTS...WHILE ANOTHER SHEARED WAVE AND
FOCUSED RIGHT ENTRANCE REGION OF THE UPPER JET IS MOVING NORTHEAST
FROM MO. HAVE BEGUN TO SEE AN UPTICK IN PRECIP WITH THIS FEATURE
ACROSS PARTS OF WEST CENTRAL IL. THE SURFACE FRONT ITSELF IS
LOCATED FROM MADISON WI TO NEAR GALESBURG AND MOVING SLOWLY
EAST...WITH POST FRONTAL FORCING /F-GEN AND SOME ELEVATED
INSTABILITY/ ALLOWING FOR SHOWERS EVEN BEHIND THIS.
AS THE SHEARED WAVE FROM MO TRANSLATES NORTHEAST AND IN TANDEM
WITH A MORE PRONOUN ED LLJ/MOISTURE TRANSPORT...DO ANTICIPATE THE
INCREASE IN SHOWER COVERAGE THAT HAS BEEN ADVERTISED TO MOVE
NORTHEAST. IT LOOKS TO MAINLY BE CONFINED TO EAST OF IL HIGHWAY
47...AND IT IS POSSIBLE IT ENDS UP EVEN BEING FURTHER EAST. THIS
SOMEWHAT MORE STEADIER RAIN/SHOWER ACTIVITY THAT IS FORECAST SHOULD
BE FAIRLY NARROW...SO TRIED TO TIME THAT FOCUS FOR THE HIGHEST
/CATEGORICAL/ POPS. THE NORTH AMERICAN RAPID REFRESH ENSEMBLE
SYSTEM /NARRE-TL/ REALLY HAS A GOOD HANDLE ON WHAT IS HAPPENING
AND WHAT IS EXPECTED TO UNFOLD...AND DOES SHOW A VERY NARROW AXIS
OF HIGHER POPS. BEFORE THAT...MAINLY SOME SPOTTY LIGHT RAIN OR
EVEN DRIZZLE IMMEDIATE AHEAD OF THE FRONT IS FAVORED. ALSO BEHIND
THE FRONT EXPECT THAT SHOWER ACTIVITY SHOULD CONTINUE ALONG THE
MID- LEVEL BAROCLINIC ZONE AND POTENTIALLY INCREASE IN COVERAGE AS
THIS FURTHER TIGHTENS WITH THE UPPER JET RIDGING PARALLEL TO IT.
SO KEEP LIKELY POPS AN HOUR OR TWO BEHIND THE FRONT BUT MENTION
MAINLY LIGHT INTENSITY. OVERALL NONE OF THIS POINTS TOWARD GREAT
THUNDER CHANCES AND HAVE DIMINISHED COVERAGE AND TIMING. NO
LIGHTNING STRIKES SEEN ANYWHERE NEAR THE AREA THE PAST SEVERAL
HOURS.
TEMPERATURE TRENDS LOOK GOOD AND HAVE JUST ADJUSTED/NUDGED TO NEAR
TERM FRONTAL POSITION.
MTF
&&
.PREV DISCUSSION...
254 PM CDT
MAIN CONCERNS TODAY REVOLVE AROUND TIMING PRECIPITATION ASSOCIATED
WITH A COLD FRONT SWEEPING ACROSS THE REGION THIS EVENING.
THIS EVENING AND TONIGHT...
A COLD FRONT SPANS FROM THE ARROWHEAD OF MINNESOTA SOUTH INTO
EASTERN IOWA THIS AFTERNOON WITH PRECIP GENERALLY OCCURRING ALONG
AND JUST AHEAD OF THIS SYSTEM. LIGHTNING ACTIVITY WAS CONFINED
MAINLY TO MISSOURI...BUT HAS REALLY DISSIPATED OVER THE PAST FEW
HOURS. LATEST RAP GUIDANCE DOES INDICATE POTENTIALLY A LITTLE MORE
ROBUST INSTABILITY THAN PREVIOUSLY THOUGHT THOUGH...AND ACCAS OVER THE
AREA THIS MORNING WOULD ALSO SUGGEST THE PRESENCE OF SOME MID LEVEL
INSTABILITY...SO WILL MAINTAIN AT LEAST A SLIGHT CHANCE MENTION FOR
THUNDERSTORMS TODAY THOUGH MAINLY EXPECT RAIN WITH A FEW EMBEDDED
MODERATE SHOWERS. WHILE THERMODYNAMICALLY UNIMPRESSIVE...DYNAMIC
FORCING THIS EVENT CONTINUES TO LEAD TO HIGH CONFIDENCE IN THE
ENTIRE CWA SEEING WETTING RAINS THIS EVENING. WATER VAPOR IMAGERY
SHOWS A WELL DEFINED NEGATIVELY TILTED VORT MAX LIFTING ACROSS THE
UPPER MIDWEST WITH DEEP MOISTURE EXTENDING SOUTH ALONG THE FRONT.
PWATS COULD BE PUSHING 2 INCHES ALONG THE FRONT AS IT SWEEPS ACROSS
THE REGION TONIGHT. WHILE THE BEST UPPER LEVEL FORCING LIES NORTH OF
THE AREA...STILL EXPECT DECENT HEIGHT FALLS TO SPREAD OVER NORTHERN
ILLINOIS...ESPECIALLY LATE THIS EVENING. NAM/GFS INDICATE COUPLED
JET WITH THE BEST AREA OF DIVERGENCE ALOFT MOVING DIRECTLY OVERHEAD
THIS EVENING. THESE COUPLED WITH THE STRONG LOW LEVEL CONVERGENCE
ALONG THE FRONT SHOULD LEAD TO A DEEP VERTICAL RESPONSE...WITH
ACTIVITY ALONG THE FRONT INCREASING IN COVERAGE/INTENSITY LATE THIS
EVENING AS THE FRONT MOVES ACROSS THE CENTRAL AND EASTERN PORTIONS
OF THE CWA.
SUNDAY THROUGH TUESDAY...
FLAT RIDGING WILL BUILD OVER THE LOCAL AREA THROUGH THIS PERIOD WITH
THE MAIN JET STREAM SETTING UP FROM THE PACIFIC NORTHWEST INTO THE
NORTHERN GREAT LAKES...RESULTING IN DRY WEATHER WITH PRECIP CHANCES
STAYING NORTH OF THE AREA. AT THE SURFACE...HIGH PRESSURE WILL BUILD
IN BEHIND THE DEPARTING COLD FRONT SUNDAY. NORTH/NORTHEAST WINDS
SUNDAY WILL KEEP CONDITIONS QUITE A BIT COOLER NEAR THE LAKE FRONT
SUNDAY...LIKELY IN THE MID 60S...BUT TEMPERATURES FARTHER INLAND
SHOULD BE ABLE TO RISE INTO THE LOW TO MID 70S. CLEAR SKIES AND CALM
WINDS UNDER THE RIDGE AXIS SUNDAY NIGHT WILL ALLOW TEMPERATURES TO
EFFECTIVELY RADIATE WITH OVERNIGHT LOWS EXPECTED IN THE LOW TO MID
40S OUTSIDE OF URBAN HEAT ISLAND OF CHICAGO...WHICH IS EXPECTED TO
STAY PROPPED INTO THE MID 50S. WOULDNT BE SURPRISED IF SOME OF THE
TYPICAL COLD SPOTS DIP INTO THE 30S. WILL HAVE TO KEEP AN EYE ON FOG
SUNDAY NIGHT...BUT FOR NOW GUIDANCE SUGGESTS THAT DEW POINTS MAY BE
TOO DRY FOR WIDESPREAD FOG DEVELOP. WITH RECENT RAINFALL
THOUGH...NOT CONFIDENT THAT MODELS ARE HANDLING LOW LEVEL MOISTURE
VERY WELL. WILL INCLUDE MENTION FOR PATCHY FOG OUTSIDE THE METRO
AREA.
WITH THE RIDGE AXIS GRADUALLY SHIFTING EAST OF THE AREA
ON MONDAY...RETURN FLOW WILL LEAD TO A WARMING TREND WITH MID TO
UPPER 70S MONDAY...AND 80S POSSIBLE AGAIN BY TUESDAY. GFS/EMCWF BOTH
SHOW THERMAL RIDGE LEANING OVER THE REGION TUESDAY WITH H85 TEMPS A
LITTLE WARMER THAN TODAY IN THE 16-18C RANGE...THOUGH IF RECENT
MODEL PERFORMANCE IS ANY INDICATOR...THIS MAY BE A BIT TOO WARM.
EVEN TAKING A CONSERVATIVE APPROACH...GUIDANCE APPEARS TO BE A BIT
ON THE COOL SIDE SO WILL MAINTAIN THE WARMER FORECAST OF LOW TO MID
80S.
WEDNESDAY THROUGH SATURDAY...
MODELS IN DECENT AGREEMENT THROUGH WEDNESDAY...WITH THE DEVELOPMENT
OF A DEEP TROUGH OVER THE WEST COAST WEDNESDAY NIGHT...THEN BEGIN TO
DIVERGE WITH TIMING/STRENGTH INTO THE WEEKEND. THE UPPER TROUGH IS
EXPECTED TO PROGRESS EAST ACROSS THE ROCKIES...WITH SURFACE LOW
DEVELOPING OVER THE PLAINS AND A WARM FRONT LIFTING NORTH ACROSS THE
LOCAL AREA. TIMING IS THE MAIN ISSUE. THE GFS IS FASTEST...FOLLOWED
BY THE ECMWF AND THEN THE GFS ENSEMBLE MEAN. A SPAGHETTI PLOT OF
GEFS MEMBERS SHOWING SIGNIFICANT SPREAD BY FRIDAY EVENING...WITH THE
MOST PROGRESSIVE MEMBER SHOWING THE TROUGH AXIS NEARING THE
MISSISSIPPI VALLEY BY FRIDAY EVENING...WHILE SLOWEST MEMBERS HAVE A
DEEPER CLOSED LOW STILL OVER THE INTERMOUNTAIN WEST. ALL THIS BOILS
DOWN TO VERY LOW CONFIDENCE IN THE EXTENDED...THUS MAINTAINED A
BLENDED MODEL SOLUTION IN THE EXTENDED FORECAST...UNTIL DETAILS
START TO BECOME MORE CLEAR.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* INCREASING CHANCES FOR RAIN TOWARD 03/04Z WITH APPROACHING COLD FRONT.
* MVFR CIGS ARRIVING BY MID EVENING.
* WINDS SHIFTING TO NORTHWEST WITH FRONTAL PASSAGE...WITH SOME
SHOWERS AND MVFR CIGS LINGERING BEHIND FRONT BEFORE CLEARING.
MDB
//DISCUSSION...UPDATED 00Z...
COLD FRONT MAKING EASTWARD PROGRESS INTO NW IL AT 00Z. BAND OF
LIGHT RAIN/SPRINKLES CONTINUES TO MOVE EAST AS WELL AND IS WORKING
INTO THE CHICAGO METRO. NEW RAIN DEVELOPMENT IS UNDERWAY IN A
NARROW BAND SOUTHWEST OF THE TERMINALS NEAR KUIN AND FURTHER
DEVELOPMENT IS EXPECTED AS UPPER LEVEL SUPPORT INCREASES. EXPECT
THAT THE CURRENT BAND OF LIGHT RAIN WILL CONTINUE ACROSS THE AREA
BUT THERE MAY BE A SLIGHT UPTICK IN COVERAGE/INTENSITY AS IT DOES
SO SO WILL MAINTAIN -SHRA MENTION EARLY THIS EVENING AT
ORD/MDW/DPA/GYY WITH THE EXPANDING PRECIP TO THE SW ARRIVING LATER
THIS EVENING. AREA OF MVFR CIGS IS ALSO APPROACHING FROM THE WEST
AND SHOULD ARRIVE BY MID EVENING ACROSS THE CHI AREA AND SHORTLY
AT RFD. THERE ALSO APPEARS TO BE A VERY NARROW BAND OF DRIZZLE
WITH 2-3SM VSBY NEAR RFD NOW AND IT IS NOT CLEAR THAT THIS WILL
TRANSLATE MUCH FURTHER EASTWARD SO WILL NEED TO MONITOR. ASSUMING
THE RAIN TO THE SOUTHWEST DOES INCREASE IN COVERAGE AND ARRIVE
LATE EVENING THEN BRIEF/IFR/MVFR VSBY IS POSSIBLE. CIGS WILL ALSO
LOWER TO LOW END MVFR IF NOT BRIEF IFR WITH THE RAIN AND RIGHT
AHEAD OF THE FRONT. SLOWED TIMING OF FRONTAL PASSAGE AND RESULTANT
SHIFT TO NORTHWEST SLIGHTLY. EXPECT THAT LOWER END MVFR CIGS WILL
LINGER FOR A FEW HOURS AFTER THE FRONT PASSES AS WILL SCATTERED
SHOWERS. CLEARING IS EXPECTED OVERNIGHT WITH WINDS DIMINISHING A
BIT AS WELL. VFR IS EXPECTED FOR SUNDAY WITH A FEW CUMULUS
POSSIBLE. NORTH-NORTHWEST WINDS WILL CONTINUE BUT SHOULD TURN
NORTHEAST ACROSS THE CHICAGO METRO DURING THE AFTERNOON. HIGH
PRESSURE WILL PASS RIGHT OVER THE AREA SUNDAY EVENING ALLOWING
WINDS TO TURN SOUTHEASTERLY OR BECOME CALM/LIGHT AND VARIABLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH CONFIDENCE IN RAIN ARRIVING TOWARD 03/04Z...LOW-
MEDIUM CONFIDENCE IN COVERAGE/INTENSITY.
* MEDIUM-HIGH CONFIDENCE IN MVFR CIGS ARRIVING...MEDIUM CONFIDENCE
IN TIMING.
* HIGH CONFIDENCE IN WIND TRENDS...MEDIUM CONFIDENCE IN A FEW
HOURS OF LINGERING SHOWERS/MVFR BEHIND FRONT...HIGH CONFIDENCE
IN CLEARING TREND OVERNIGHT.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH WEDNESDAY...VFR.
THURSDAY AND FRIDAY...CHANCE SHRA/TSRA.
MDB
&&
.MARINE...
220 PM CDT
HIGH PRESSURE IS OVER NEW ENGLAND WHILE A LOW IS OVER NORTHERN
MINNESOTA/SOUTHWEST ONTARIO. WINDS HAVE STRUGGLED TO STRENGTHEN
OVER THE LAKE TODAY...BUT ARE FINALLY STARTING TO PICK UP. WILL
KEEP THE SMALL CRAFT ADVISORY GOING AND END IT AT 7PM TONIGHT AS
PLANNED. THE HIGH SLOWLY SHIFTS OFF THE NE ATLANTIC COAST WHILE THE
LOW REACHES HUDSON BAY TOMORROW. GUIDANCE IS STILL SUGGESTING WINDS
WILL PICK UP TO 30KT THIS EVENING OVER THE NORTH HALF TO THE LAKE.
IN ADDITION...SOUNDINGS STILL INDICATE THAT GALE FORCE GUSTS LIE
JUST 200 FT ABOVE THE SURFACE. WILL KEEP OCNL GALE FORCE GUSTS GOING
THROUGH 03Z AND HIGHER VESSELS WILL PROBABLY ENCOUNTER MORE THAN
JUST OCNL GALE FORCE GUSTS.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE LATE THIS EVENING WITH NW
WINDS 15-20 KT BEHIND IT. A WEAK SURFACE RIDGE MOVES OVER THE LAKE
TOMORROW AND WINDS QUICKLY DIMINISH. THE HIGH PUSHES EAST WITH
SOUTH WINDS EXPECTED ACROSS THE LAKE MONDAY AND TUESDAY. ANOTHER
LOW PASSES OVER THE SOUTHERN CANADIAN PRAIRIES EARLY NEXT WEEK...AND
EXPECTING THE PRESSURE GRADIENT TO TIGHTEN OVER THE NORTHERN HALF OF
THE LAKE. THEREFORE...HAVE 30KT WINDS OVER THE NORTHERN HALF OF THE
LAKE MONDAY NIGHT AND TUESDAY. WINDS TURN WEST AS THE LOW PUSHES
EAST AND ANOTHER WEAK SURFACE RIDGE SETS UP OVER THE LAKE.
LATE NEXT WEEK STILL LOOKS INTERESTING WITH A LARGE LOW CROSSING THE
PLAINS AND PASSING OVER LAKE SUPERIOR. MODEL TIMING IS NOT
CONSISTENT BETWEEN THE MODELS AND MODEL RUNS. THAT BEING SAID
GUIDANCE IS STILL SUGGESTING STRONG SOUTH WINDS LATE NEXT WEEK AHEAD
OF THE LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
657 PM CDT SAT SEP 28 2013
.DISCUSSION...
254 PM CDT
MAIN CONCERNS TODAY REVOLVE AROUND TIMING PRECIPITATION ASSOCIATED
WITH A COLD FRONT SWEEPING ACROSS THE REGION THIS EVENING.
THIS EVENING AND TONIGHT...
A COLD FRONT SPANS FROM THE ARROWHEAD OF MINNESOTA SOUTH INTO
EASTERN IOWA THIS AFTERNOON WITH PRECIP GENERALLY OCCURRING ALONG
AND JUST AHEAD OF THIS SYSTEM. LIGHTNING ACTIVITY WAS CONFINED
MAINLY TO MISSOURI...BUT HAS REALLY DISSIPATED OVER THE PAST FEW
HOURS. LATEST RAP GUIDANCE DOES INDICATE POTENTIALLY A LITTLE MORE
ROBUST INSTABILITY THAN PREVIOUSLY THOUGHT THOUGH...AND ACCAS OVER THE
AREA THIS MORNING WOULD ALSO SUGGEST THE PRESENCE OF SOME MID LEVEL
INSTABILITY...SO WILL MAINTAIN AT LEAST A SLIGHT CHANCE MENTION FOR
THUNDERSTORMS TODAY THOUGH MAINLY EXPECT RAIN WITH A FEW EMBEDDED
MODERATE SHOWERS. WHILE THERMODYNAMICALLY UNIMPRESSIVE...DYNAMIC
FORCING THIS EVENT CONTINUES TO LEAD TO HIGH CONFIDENCE IN THE
ENTIRE CWA SEEING WETTING RAINS THIS EVENING. WATER VAPOR IMAGERY
SHOWS A WELL DEFINED NEGATIVELY TILTED VORT MAX LIFTING ACROSS THE
UPPER MIDWEST WITH DEEP MOISTURE EXTENDING SOUTH ALONG THE FRONT.
PWATS COULD BE PUSHING 2 INCHES ALONG THE FRONT AS IT SWEEPS ACROSS
THE REGION TONIGHT. WHILE THE BEST UPPER LEVEL FORCING LIES NORTH OF
THE AREA...STILL EXPECT DECENT HEIGHT FALLS TO SPREAD OVER NORTHERN
ILLINOIS...ESPECIALLY LATE THIS EVENING. NAM/GFS INDICATE COUPLED
JET WITH THE BEST AREA OF DIVERGENCE ALOFT MOVING DIRECTLY OVERHEAD
THIS EVENING. THESE COUPLED WITH THE STRONG LOW LEVEL CONVERGENCE
ALONG THE FRONT SHOULD LEAD TO A DEEP VERTICAL RESPONSE...WITH
ACTIVITY ALONG THE FRONT INCREASING IN COVERAGE/INTENSITY LATE THIS
EVENING AS THE FRONT MOVES ACROSS THE CENTRAL AND EASTERN PORTIONS
OF THE CWA.
SUNDAY THROUGH TUESDAY...
FLAT RIDGING WILL BUILD OVER THE LOCAL AREA THROUGH THIS PERIOD WITH
THE MAIN JET STREAM SETTING UP FROM THE PACIFIC NORTHWEST INTO THE
NORTHERN GREAT LAKES...RESULTING IN DRY WEATHER WITH PRECIP CHANCES
STAYING NORTH OF THE AREA. AT THE SURFACE...HIGH PRESSURE WILL BUILD
IN BEHIND THE DEPARTING COLD FRONT SUNDAY. NORTH/NORTHEAST WINDS
SUNDAY WILL KEEP CONDITIONS QUITE A BIT COOLER NEAR THE LAKE FRONT
SUNDAY...LIKELY IN THE MID 60S...BUT TEMPERATURES FARTHER INLAND
SHOULD BE ABLE TO RISE INTO THE LOW TO MID 70S. CLEAR SKIES AND CALM
WINDS UNDER THE RIDGE AXIS SUNDAY NIGHT WILL ALLOW TEMPERATURES TO
EFFECTIVELY RADIATE WITH OVERNIGHT LOWS EXPECTED IN THE LOW TO MID
40S OUTSIDE OF URBAN HEAT ISLAND OF CHICAGO...WHICH IS EXPECTED TO
STAY PROPPED INTO THE MID 50S. WOULDNT BE SURPRISED IF SOME OF THE
TYPICAL COLD SPOTS DIP INTO THE 30S. WILL HAVE TO KEEP AN EYE ON FOG
SUNDAY NIGHT...BUT FOR NOW GUIDANCE SUGGESTS THAT DEW POINTS MAY BE
TOO DRY FOR WIDESPREAD FOG DEVELOP. WITH RECENT RAINFALL
THOUGH...NOT CONFIDENT THAT MODELS ARE HANDLING LOW LEVEL MOISTURE
VERY WELL. WILL INCLUDE MENTION FOR PATCHY FOG OUTSIDE THE METRO
AREA.
WITH THE RIDGE AXIS GRADUALLY SHIFTING EAST OF THE AREA
ON MONDAY...RETURN FLOW WILL LEAD TO A WARMING TREND WITH MID TO
UPPER 70S MONDAY...AND 80S POSSIBLE AGAIN BY TUESDAY. GFS/EMCWF BOTH
SHOW THERMAL RIDGE LEANING OVER THE REGION TUESDAY WITH H85 TEMPS A
LITTLE WARMER THAN TODAY IN THE 16-18C RANGE...THOUGH IF RECENT
MODEL PERFORMANCE IS ANY INDICATOR...THIS MAY BE A BIT TOO WARM.
EVEN TAKING A CONSERVATIVE APPROACH...GUIDANCE APPEARS TO BE A BIT
ON THE COOL SIDE SO WILL MAINTAIN THE WARMER FORECAST OF LOW TO MID
80S.
WEDNESDAY THROUGH SATURDAY...
MODELS IN DECENT AGREEMENT THROUGH WEDNESDAY...WITH THE DEVELOPMENT
OF A DEEP TROUGH OVER THE WEST COAST WEDNESDAY NIGHT...THEN BEGIN TO
DIVERGE WITH TIMING/STRENGTH INTO THE WEEKEND. THE UPPER TROUGH IS
EXPECTED TO PROGRESS EAST ACROSS THE ROCKIES...WITH SURFACE LOW
DEVELOPING OVER THE PLAINS AND A WARM FRONT LIFTING NORTH ACROSS THE
LOCAL AREA. TIMING IS THE MAIN ISSUE. THE GFS IS FASTEST...FOLLOWED
BY THE ECMWF AND THEN THE GFS ENSEMBLE MEAN. A SPAGHETTI PLOT OF
GEFS MEMBERS SHOWING SIGNIFICANT SPREAD BY FRIDAY EVENING...WITH THE
MOST PROGRESSIVE MEMBER SHOWING THE TROUGH AXIS NEARING THE
MISSISSIPPI VALLEY BY FRIDAY EVENING...WHILE SLOWEST MEMBERS HAVE A
DEEPER CLOSED LOW STILL OVER THE INTERMOUNTAIN WEST. ALL THIS BOILS
DOWN TO VERY LOW CONFIDENCE IN THE EXTENDED...THUS MAINTAINED A
BLENDED MODEL SOLUTION IN THE EXTENDED FORECAST...UNTIL DETAILS
START TO BECOME MORE CLEAR.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* INCREASING CHANCES FOR RAIN TOWARD 03/04Z WITH APPROACHING COLD FRONT.
* MVFR CIGS ARRIVING BY MID EVENING.
* WINDS SHIFTING TO NORTHWEST WITH FRONTAL PASSAGE...WITH SOME
SHOWERS AND MVFR CIGS LINGERING BEHIND FRONT BEFORE CLEARING.
MDB
//DISCUSSION...UPDATED 00Z...
COLD FRONT MAKING EASTWARD PROGRESS INTO NW IL AT 00Z. BAND OF
LIGHT RAIN/SPRINKLES CONTINUES TO MOVE EAST AS WELL AND IS WORKING
INTO THE CHICAGO METRO. NEW RAIN DEVELOPMENT IS UNDERWAY IN A
NARROW BAND SOUTHWEST OF THE TERMINALS NEAR KUIN AND FURTHER
DEVELOPMENT IS EXPECTED AS UPPER LEVEL SUPPORT INCREASES. EXPECT
THAT THE CURRENT BAND OF LIGHT RAIN WILL CONTINUE ACROSS THE AREA
BUT THERE MAY BE A SLIGHT UPTICK IN COVERAGE/INTENSITY AS IT DOES
SO SO WILL MAINTAIN -SHRA MENTION EARLY THIS EVENING AT
ORD/MDW/DPA/GYY WITH THE EXPANDING PRECIP TO THE SW ARRIVING LATER
THIS EVENING. AREA OF MVFR CIGS IS ALSO APPROACHING FROM THE WEST
AND SHOULD ARRIVE BY MID EVENING ACROSS THE CHI AREA AND SHORTLY
AT RFD. THERE ALSO APPEARS TO BE A VERY NARROW BAND OF DRIZZLE
WITH 2-3SM VSBY NEAR RFD NOW AND IT IS NOT CLEAR THAT THIS WILL
TRANSLATE MUCH FURTHER EASTWARD SO WILL NEED TO MONITOR. ASSUMING
THE RAIN TO THE SOUTHWEST DOES INCREASE IN COVERAGE AND ARRIVE
LATE EVENING THEN BRIEF/IFR/MVFR VSBY IS POSSIBLE. CIGS WILL ALSO
LOWER TO LOW END MVFR IF NOT BRIEF IFR WITH THE RAIN AND RIGHT
AHEAD OF THE FRONT. SLOWED TIMING OF FRONTAL PASSAGE AND RESULTANT
SHIFT TO NORTHWEST SLIGHTLY. EXPECT THAT LOWER END MVFR CIGS WILL
LINGER FOR A FEW HOURS AFTER THE FRONT PASSES AS WILL SCATTERED
SHOWERS. CLEARING IS EXPECTED OVERNIGHT WITH WINDS DIMINISHING A
BIT AS WELL. VFR IS EXPECTED FOR SUNDAY WITH A FEW CUMULUS
POSSIBLE. NORTH-NORTHWEST WINDS WILL CONTINUE BUT SHOULD TURN
NORTHEAST ACROSS THE CHICAGO METRO DURING THE AFTERNOON. HIGH
PRESSURE WILL PASS RIGHT OVER THE AREA SUNDAY EVENING ALLOWING
WINDS TO TURN SOUTHEASTERLY OR BECOME CALM/LIGHT AND VARIABLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH CONFIDENCE IN RAIN ARRIVING TOWARD 03/04Z...LOW-
MEDIUM CONFIDENCE IN COVERAGE/INTENSITY.
* MEDIUM-HIGH CONFIDENCE IN MVFR CIGS ARRIVING...MEDIUM CONFIDENCE
IN TIMING.
* HIGH CONFIDENCE IN WIND TRENDS...MEDIUM CONFIDENCE IN A FEW
HOURS OF LINGERING SHOWERS/MVFR BEHIND FRONT...HIGH CONFIDENCE
IN CLEARING TREND OVERNIGHT.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH WEDNESDAY...VFR.
THURSDAY AND FRIDAY...CHANCE SHRA/TSRA.
MDB
&&
.MARINE...
220 PM CDT
HIGH PRESSURE IS OVER NEW ENGLAND WHILE A LOW IS OVER NORTHERN
MINNESOTA/SOUTHWEST ONTARIO. WINDS HAVE STRUGGLED TO STRENGTHEN
OVER THE LAKE TODAY...BUT ARE FINALLY STARTING TO PICK UP. WILL
KEEP THE SMALL CRAFT ADVISORY GOING AND END IT AT 7PM TONIGHT AS
PLANNED. THE HIGH SLOWLY SHIFTS OFF THE NE ATLANTIC COAST WHILE THE
LOW REACHES HUDSON BAY TOMORROW. GUIDANCE IS STILL SUGGESTING WINDS
WILL PICK UP TO 30KT THIS EVENING OVER THE NORTH HALF TO THE LAKE.
IN ADDITION...SOUNDINGS STILL INDICATE THAT GALE FORCE GUSTS LIE
JUST 200 FT ABOVE THE SURFACE. WILL KEEP OCNL GALE FORCE GUSTS GOING
THROUGH 03Z AND HIGHER VESSELS WILL PROBABLY ENCOUNTER MORE THAN
JUST OCNL GALE FORCE GUSTS.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE LATE THIS EVENING WITH NW
WINDS 15-20 KT BEHIND IT. A WEAK SURFACE RIDGE MOVES OVER THE LAKE
TOMORROW AND WINDS QUICKLY DIMINISH. THE HIGH PUSHES EAST WITH
SOUTH WINDS EXPECTED ACROSS THE LAKE MONDAY AND TUESDAY. ANOTHER
LOW PASSES OVER THE SOUTHERN CANADIAN PRAIRIES EARLY NEXT WEEK...AND
EXPECTING THE PRESSURE GRADIENT TO TIGHTEN OVER THE NORTHERN HALF OF
THE LAKE. THEREFORE...HAVE 30KT WINDS OVER THE NORTHERN HALF OF THE
LAKE MONDAY NIGHT AND TUESDAY. WINDS TURN WEST AS THE LOW PUSHES
EAST AND ANOTHER WEAK SURFACE RIDGE SETS UP OVER THE LAKE.
LATE NEXT WEEK STILL LOOKS INTERESTING WITH A LARGE LOW CROSSING THE
PLAINS AND PASSING OVER LAKE SUPERIOR. MODEL TIMING IS NOT
CONSISTENT BETWEEN THE MODELS AND MODEL RUNS. THAT BEING SAID
GUIDANCE IS STILL SUGGESTING STRONG SOUTH WINDS LATE NEXT WEEK AHEAD
OF THE LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 7 PM SATURDAY.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 7 PM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
1228 PM CDT FRI SEP 27 2013
.DISCUSSION...
ISSUED AT 340AM CDT FRI SEP 27 2013
MUCH OF THE WEATHER OF NOTE THROUGH THE PERIOD IS IN THE NEXT 48
HOURS. ALTHOUGH THE PARENT LONG WAVE TROUGH FOR THIS WEEKEND IS
STILL WELL TO OUR WEST...ELEVATED INSTABILITY AND DIURNAL WARM
ADVECTION MAX HAS RECENTLY DEVELOPED OUT AHEAD RESULTING IN HIGH
BASED CONVECTION ALONG THE MO RIVER. THIS BAROCLINIC ZONE WAS NOTED
FAIRLY WELL AROUND THE 315K ISENT SURFACE AND IS COINCIDENT WITH
SEVERAL HUNDRED RAP MUCAPES TOWARD 12Z. VARIOUS HI RES MODELS SHOW
THIS DEVELOPMENT AS WELL. THIS THERMODYNAMIC FORCING WANES LATER
THIS MORNING HOWEVER WITH ATTENTION TURNING TOWARD TEMPS AND WINDS
SO ONLY HAVE SCATTERED MORNING WORDING NW. FORECAST SOUNDINGS
HANDLED HIGHS WELL YESTERDAY AND SIMILAR MIXING WOULD RESULT IN
MID/UPPER 80S FOR MAXES...WHICH WOULD COME WITHIN A FEW DEGREES OF
RECORDS IN SPOTS. MIXING WILL NOT BE DEEP...ONLY UP TO AROUND
1KM...BUT STRONG RETURN FLOW MAY BRING GUSTS INTO THE 20S AND 30S
/KTS/ IN THE BOUNDARY LAYER WITH HIGHEST GUSTS NW. ALTHOUGH MIXING
WILL NOT DROP DEWPOINTS TOO MUCH WINDS MAY LEAD TO AN ELEVATED
FIRE DANGER...ESPECIALLY NW HALF...AND THIS MENTION WILL REMAIN IN
THE HWO.
LONG WAVE TROUGH FINALLY BEGINS TO ADVANCE TONIGHT AS CURRENT STRONG
SHORT WAVE/PV ANOMALY BEGINS TO LIFT OUT OF ITS BASE FROM UT ACROSS
THE CENTRAL/NRN PLAINS INTO SAT. AS IS OFTEN TYPICAL WITH FALL
SYSTEMS IT WILL BE DIFFICULT TO GET MUCH INSTABILITY...MUCAPES ONLY
GET TO A FEW HUNDRED J/KG. DEEP AND STRONG THERMODYNAMIC AND
KINEMATIC FORCING IS NEARLY COINCIDENT WITH THE FROPA AND SATURATES
THE SOUNDINGS...REDUCING ELEVATED LAPSE RATES AND ABILITY TO
GENERATE MUCH INSOLATION AND SURFACE BASED POTENTIAL. HOWEVER
CONSIDERING THE STRENGTH OF THE FORCING CONFIDENCE REMAINS HIGH IN A
BAND OF WEAK CONVECTION MARCHING W-E ACROSS IA SAT SO HAVE CONTINUED
CATEGORICAL WORDING. PRECIP LOOKS FAIRLY TRANSIENT WITH ONLY A
THREE TO FOUR HOUR WINDOW OF RAIN PER THE NAM AND HI RES MODEL
REFLECTIVITY DEPICTIONS. SEVERE POTENTIAL IS LOW BECAUSE OF THE
LIMITED CAPE...HOWEVER IF GREATER INSTABILITY CAN SOMEHOW BE
REALIZED THE STRONG DEEP SHEAR COULD LEAD TO SUPERCELLS. 0-1KM
SHEAR IS FAIRLY STRONG TOO...BUT SOUNDINGS SHOW LITTLE HOPE OF
GETTING FAVORABLE THERMODYNAMIC CONDITIONS FOR TORNADOES.
CONFIDENCE IS SOMEWHAT LOW IN TEMPS SAT DUE TO PRECIP AND FROPA
FOLLOWED BY AFTERNOON POST-FRONTAL MIXING AND RECOVERY.
QUICKLY DEPARTING SYSTEM WILL LEAD TO FAIR WEATHER SAT NIGHT
THROUGH THE WEEKEND...AND EVEN INTO MIDWEEK. COLD ADVECTION WILL
BE STRONG IMMEDIATELY BEHIND THE FROPA...BUT LEE SIDE TROUGHING
WILL BE RIGHT BACK IN PLACE BY SUN NIGHT ALLOWING TEMPS TO QUICKLY
RECOVER BACK TO READINGS SIMILAR TO EARLIER THIS WEEK. STRONG
WESTERLIES WILL BE TO OUR NORTH KEEPING US DRY UNTIL POSSIBLY THU
AS WRN TROUGH BEGINS TO DEEPEN ONCE AGAIN. THERE ARE SOME PERIODS
OF WEAK FORCING...BUT THEY WILL BE MOISTURE STARVED. HAVE REDUCED
POPS IN THE EXTENDED...ONLY RELUCTANTLY HOLDING ONTO LOW CHANCES THU
DURING SOMEWHAT ENHANCED PERIOD OF WARM ADVECTION.
&&
.AVIATION...27/18Z
ISSUED AT 1222 PM CDT FRI SEP 27 2013
WINDS WILL REMAIN SOUTHEASTERLY AND STRONG THROUGH THE AFTERNOON
WITH GUSTS. GUSTS WILL DIMINISH AFTER 00Z...THOUGH WINDS WILL
REMAIN STRONG. APPROACHING FRONTAL BOUNDARY WILL BRING PRECIPITATION
TO SITES BEGINNING NEAR/AFTER 12Z...SPREADING EAST TO ALL SITES BY
18Z. WILL SEE MVFR CEILINGS WITH BOUNDARY AND POSSIBLE LOWER IFR
CEILINGS/VISIBILITIES WITH PRECIPITATION. CEILINGS WILL REMAIN MVFR
BEHIND PRECIPITATION.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
DISCUSSION...SMALL
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
340 AM CDT FRI SEP 27 2013
.DISCUSSION...
ISSUED AT 340 AM CDT FRI SEP 27 2013
MUCH OF THE WEATHER OF NOTE THROUGH THE PERIOD IS IN THE NEXT 48
HOURS. ALTHOUGH THE PARENT LONG WAVE TROUGH FOR THIS WEEKEND IS
STILL WELL TO OUR WEST...ELEVATED INSTABILITY AND DIURNAL WARM
ADVECTION MAX HAS RECENTLY DEVELOPED OUT AHEAD RESULTING IN HIGH
BASED CONVECTION ALONG THE MO RIVER. THIS BAROCLINIC ZONE WAS NOTED
FAIRLY WELL AROUND THE 315K ISENT SURFACE AND IS COINCIDENT WITH
SEVERAL HUNDRED RAP MUCAPES TOWARD 12Z. VARIOUS HI RES MODELS SHOW
THIS DEVELOPMENT AS WELL. THIS THERMODYNAMIC FORCING WANES LATER
THIS MORNING HOWEVER WITH ATTENTION TURNING TOWARD TEMPS AND WINDS
SO ONLY HAVE SCATTERED MORNING WORDING NW. FORECAST SOUNDINGS
HANDLED HIGHS WELL YESTERDAY AND SIMILAR MIXING WOULD RESULT IN
MID/UPPER 80S FOR MAXES...WHICH WOULD COME WITHIN A FEW DEGREES OF
RECORDS IN SPOTS. MIXING WILL NOT BE DEEP...ONLY UP TO AROUND
1KM...BUT STRONG RETURN FLOW MAY BRING GUSTS INTO THE 20S AND 30S
/KTS/ IN THE BOUNDARY LAYER WITH HIGHEST GUSTS NW. ALTHOUGH MIXING
WILL NOT DROP DEWPOINTS TOO MUCH WINDS MAY LEAD TO AN ELEVATED
FIRE DANGER...ESPECIALLY NW HALF...AND THIS MENTION WILL REMAIN IN
THE HWO.
LONG WAVE TROUGH FINALLY BEGINS TO ADVANCE TONIGHT AS CURRENT STRONG
SHORT WAVE/PV ANOMALY BEGINS TO LIFT OUT OF ITS BASE FROM UT ACROSS
THE CENTRAL/NRN PLAINS INTO SAT. AS IS OFTEN TYPICAL WITH FALL
SYSTEMS IT WILL BE DIFFICULT TO GET MUCH INSTABILITY...MUCAPES ONLY
GET TO A FEW HUNDRED J/KG. DEEP AND STRONG THERMODYNAMIC AND
KINEMATIC FORCING IS NEARLY COINCIDENT WITH THE FROPA AND SATURATES
THE SOUNDINGS...REDUCING ELEVATED LAPSE RATES AND ABILITY TO
GENERATE MUCH INSOLATION AND SURFACE BASED POTENTIAL. HOWEVER
CONSIDERING THE STRENGTH OF THE FORCING CONFIDENCE REMAINS HIGH IN A
BAND OF WEAK CONVECTION MARCHING W-E ACROSS IA SAT SO HAVE CONTINUED
CATEGORICAL WORDING. PRECIP LOOKS FAIRLY TRANSIENT WITH ONLY A
THREE TO FOUR HOUR WINDOW OF RAIN PER THE NAM AND HI RES MODEL
REFLECTIVITY DEPICTIONS. SEVERE POTENTIAL IS LOW BECAUSE OF THE
LIMITED CAPE...HOWEVER IF GREATER INSTABILITY CAN SOMEHOW BE
REALIZED THE STRONG DEEP SHEAR COULD LEAD TO SUPERCELLS. 0-1KM
SHEAR IS FAIRLY STRONG TOO...BUT SOUNDINGS SHOW LITTLE HOPE OF
GETTING FAVORABLE THERMODYNAMIC CONDITIONS FOR TORNADOES.
CONFIDENCE IS SOMEWHAT LOW IN TEMPS SAT DUE TO PRECIP AND FROPA
FOLLOWED BY AFTERNOON POST-FRONTAL MIXING AND RECOVERY.
QUICKLY DEPARTING SYSTEM WILL LEAD TO FAIR WEATHER SAT NIGHT
THROUGH THE WEEKEND...AND EVEN INTO MIDWEEK. COLD ADVECTION WILL
BE STRONG IMMEDIATELY BEHIND THE FROPA...BUT LEE SIDE TROUGHING
WILL BE RIGHT BACK IN PLACE BY SUN NIGHT ALLOWING TEMPS TO QUICKLY
RECOVER BACK TO READINGS SIMILAR TO EARLIER THIS WEEK. STRONG
WESTERLIES WILL BE TO OUR NORTH KEEPING US DRY UNTIL POSSIBLY THU
AS WRN TROUGH BEGINS TO DEEPEN ONCE AGAIN. THERE ARE SOME PERIODS
OF WEAK FORCING...BUT THEY WILL BE MOISTURE STARVED. HAVE REDUCED
POPS IN THE EXTENDED...ONLY RELUCTANTLY HOLDING ONTO LOW CHANCES THU
DURING SOMEWHAT ENHANCED PERIOD OF WARM ADVECTION.
&&
.AVIATION...27/06Z
ISSUED AT 1134 PM CDT THU SEP 26 2013
VFR CONDITIONS EXPECTED THROUGHOUT FOR TAF PERIOD. ONLY WEATHER
FEATURE WHICH MAY BE OF SLIGHT CONCERN ARE THE STRONG WINDS WHICH
SHOULD LAST FROM AROUND 14Z FRI THROUGH 00Z SAT. WINDS EXPECTED TO
BE FROM THE SOUTH TO SOUTHEAST SUSTAINED AROUND 15 TO 20 KT...WITH
GUSTS UPWARDS OF 25 TO 30 KT. FRIDAY LATE MORNING THROUGH SUNSET.
WILL GRADUALLY SEE UPPER LEVEL CLOUDS INCREASE AND THICKEN FRIDAY
AFTERNOON IN ADVANCE OF SATURDAY/S FORECAST FRONTAL PASSAGE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
DISCUSSION...SMALL
AVIATION...KOTENBERG
AREA FORECAST DISCUSSION
NWS TOPEKA KS
327 PM CDT Fri Sep 27 2013
.SHORT TERM...(This Evening through Saturday)
Issued at 252 PM CDT FRI SEP 27 2013
Tonight through Saturday...
Analysis of the water vapor imagery at 19z depicts the potent
shortwave trough axis rotating through southern Wyoming. An embedded
wave and mid level jet streak within the mean flow was lifting
northward into western Kansas. Looking at the surface, the potent
cold front was oriented southwest to northeast from eastern Colorado
through northwest Kansas, through central and northern Nebraska.
Observations noted 30 degree F temp differences between the
boundaries with upper 40s in northeast Colorado. The surface trough
undergoing lee cyclogenesis over southern Colorado continued to
provide strong southerly winds between 15 and 25 mph with gusts over
30 mph during the current peak heating hours. In turn gulf moisture
streaming northward in advance of the sfc trough has brought
dewpoint temperatures into the low 60s. The aforementioned mid level
wave in combination with the surface front has continued to generate
elevated showers lifting northward across western Kansas.
As the upper wave lifts northeastward into the northern plains,
expect the lee surface trough and frontal boundary to quickly usher
eastward towards northeast Kansas. A line of numerous showers and
thunderstorms are likely to develop in vicinity and along the
boundary during the evening and overnight hours. Consistency between
the latest runs of the 3 km HRRR peg the edge of the precip and
front entering north central areas after 07z, impacting much of east
central areas(including Topeka) after 09z. While the highest
probabilities of severe storms reside towards western and central
Kansas, expect the instability gradient to drop steadily eastward
with only a few hundred j/kg of ML cape over north central areas
around 06z. However, strong effective shear values over 50 kts may
still allow for strong gusty winds from 40 to 50 mph. Locally heavy
rain is likely with the heavier showers as pwat values range from
1.25 to 1.9 inches. QPF values did not deviate much from previous
forecast based on fast track of the front ranging from 0.30 to three
quarters of an inch. Precipitation is expected to end Saturday
afternoon with cloud cover quickly exiting southeast as a drier and
cooler airmass settles in.
Temperatures tonight depend on thickness of cloud cover and showers
with lowest readings over north central areas where cool advection
behind the front will be filtering southward. Further east, lows in
the upper 60s appear to be more common. Expect temps to hover in the
60s for much of Saturday afternoon before a gradual warmup as the
clouds thin, topping out in the low 70s. Northerly winds remain
gusty through the period as the h85 shortwave trough continues to
impact the region before exiting Saturday evening.
.LONG TERM...(Saturday Night through Friday)
Issued at 252 PM CDT FRI SEP 27 2013
As skies clear out and winds settle down behind the front on
Saturday night, overnight lows into Sunday morning are expected to
drop into the lower to middle 40s. Will need to monitor for fog
potential, but air mass is quite dry and therefore fog potential
could be limited to low spots. Sunday forecast to be sunny with
highs in the lower to middle 70s and light south winds. Lows
overnight into Monday should be a few degrees warmer as southerly
winds continue. Thermal ridge out ahead of the next approaching
trof expected to bring highs Monday through Wednesday back up
toward 80 and then lows only falling into the 50s to near 60 by
Thursday morning.
While the sensible weather forecast for Thurs/Fri remains similar
to that of mid week, the speed of an upper trof advancing eastward
into the plains will be the driver of true timing of rain chances
and colder air. Was backing off on progressive solutions as
several ensemble members along with the 00z ECMWF showing a slower
trend, however 12z runs are now coming in slightly faster. Opted
to keep slight chances for rain Thur/Fri, with timing chances too
uncertain to make large changes to a consensus forecast this far
out.
.AVIATION...(For the 18Z TAFs through 18Z Saturday
Afternoon) Issued at 1227 PM CDT FRI SEP 27 2013
VFR at KTOP/KFOE/KMHK with gusty south winds thru afternoon. Primary
focus is a cold front and line of showers/isolated thunder impacting sites
aft 07z at KMHK and 09z at KTOP/KFOE. Cigs lower to MVFR through the
early morning. Instability is limited with low confidence and only
vcts mentioned. Gusty south winds back to the southeast in the
evening before gradually veering to the west and northwest with
the fropa.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...67
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1249 PM MDT FRI SEP 27 2013
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 1230 PM MDT FRI SEP 27 2013
AS OF NOON MDT/1PM CDT...WV IMAGERY AND RAP H5 ANALYSIS SHOW
POSITIVELY TITLED TROUGH EXTENDING FROM NORTHERN ROCKIES ACROSS
THE GREAT BASIN...WITH ITS BASE NEAR THE BAJA PENINSULA. SW FLOW
IS IN PLACE ACROSS THE PLAINS WITH MID LEVEL MOISTURE PLUME
EXTENDING FROM THE PACIFIC OCEAN AND INTO WESTERN KANSAS OVER OUR
CWA. AT THE SURFACE A STATIONARY FRONT IS CURRENTLY EXTENDING FROM
ABOUT LIMON COLORADO...TO GOODLAND KS...AND NORTH INTO CENTRAL
NEBRASKA. LIGHT TO MODERATE SHOWERS HAVE DEVELOPED ALONG THE
LEADING EDGE OF THIS FRONT...WITH RECENT RADAR RETURNS SHOWING AN
INCREASE IN INTENSITY AND COVERAGE.
GUIDANCE CONTINUES TO INDICATE THIS FRONT LIFTING LATER THIS
AFTERNOON WITH INSTABILITY INCREASING EAST OF THE FRONT OVER
WESTERN/CENTRAL KANSAS. FORECAST SEEMS TO BE ON TRACK REGARDING
COVERAGE...WITH LIGHT TO MODERATE SHOWERS AND ISOLATED
THUNDERSTORMS LIKELY THIS AFTERNOON AND EVENING. HOWEVER THERE HAS
BEEN LITTLE INDICATION OF FRONT LIFTING SO FAR...AND UNTIL IT
DOES THUNDERSTORM COVERAGE (AND SEVERE THREAT) IS IN QUESTION.
LATEST RAP SHOWS 600-900 J/KG OF MUCAPE BY AROUND 00Z IN THE EAST
WHICH ISNT PARTICULARLY IMPRESSIVE...THOUGH IT IS WORTH MENTIONING
THAT THE NAM HAS OVER 1500 J/KG OF MU CAPE IN A SIMILAR AREA. THE
DIFFERENCE SEEMS TO BE TIMING/POSITION OF FRONT WITH NAM
QUICKER/FURTHER NORTH. SHEER IS VERY IMPRESSIVE WITH 0-6KM BULK
SHEER 50KT TO 80KT FROM THE EAST TO THE WEST...AND INCREASING
EFFECTIVE SHEER 40-50KT. IF WE CAN GET A STRONG ENOUGH UPDRAFT
(INSTABILITY DEPENDED) IT COULD QUICKLY BECOME SEVERE CONSIDERING
THE SHEER PROFILES. LCLS ARE STILL ADVERTISED AROUND 9-10KFT
WHICH IS PRETTY HIGH FOR A WIDESPREAD TORNADO THREAT...SO
WIND/HAIL/HEAVY RAIN CONTINUE TO BE THE PRIMARY CONCERNS THIS
AFTERNOON AND EVENING.
VERY DRY/SUBSIDENT AIR MASS WILL BUILD IN FROM THE WEST BEHIND A
COLD FRONT THIS EVENING...AND MODELS SUPPORT SHOWERS/THUNDERSTORMS
QUICKLY ENDING FROM WEST TO EAST IN THE 03-06Z PERIOD. I KEPT SOME
CHANCE POPS LINGERING THROUGH 09Z IN THE EAST TO ACCOUNT FOR A
SLOWER FRONTAL EXIT FOR THOSE LOCATIONS...HOWEVER THIS APPEARS TO
BE MAINLY A AFTERNOON/EVENING EVENT. PRECIP AMOUNTS COULD BE VERY
IMPRESSIVE CONSIDERING THE AMOUNT OF FORCING/MOISTURE
ADVERTISED...AND MODEL QPF FORECASTS CONTINUE TO SUPPORT RAINFALL
AMOUNTS FROM ONE QUARTER OF AN INCH IN THE WEST TO NEAR ONE INCH
IN THE NORTHEAST. WITH POSSIBLE TRAINING/BACK BUILDING OF
SHOWERS/THUNDERSTORMS WE WILL NEED TO MONITOR FOR POSSIBLE FLASH
FLOODING.
REGARDING WIND ADVISORY...THERE SHOULD BE A SHARP INCREASE IN
WINDS IMMEDIATELY BEHIND THE COLD FRONT THIS EVENING. LATEST MODELS
HAVE DECREASED THE WINDS ALOFT SOME FROM PREVIOUS GUIDANCE...AND
SPED UP THE FRONTAL PASSAGE. IM STILL CONFIDENT WE WILL SEE A
BRIEF PERIOD OF NEAR ADVISORY TO ABOVE ADVISORY WIND GUSTS THIS
EVENING THROUGH AROUND MIDNIGHT IN THE EAST...SO I DIDNT SEE A
REASON TO CANCEL THE WIND ADVISORY. IT CURRENTLY RUNS THROUGH
12Z...WHICH MANY BE TOO LONG...HOWEVER IT DOES COVER THE
POSSIBILITY OF A SLOWER FROPA IN THE EAST.
WITH CLEARING SKIES AND A VERY COOL/DRY AIR MASS ADVECTING IN FROM
THE WEST AFTER MIDNIGHT WE WILL LIKELY SEE SOME OF THE COOLER TEMPS
SO FAR THIS MONTH. IF WINDS DECREASE BELOW 10KT (WHICH IS NOT
CURRENTLY EXPECTED) WE COULD COOL TO THE LOW TO MID 30S IN THE
WEST WHICH WOULD PUT US WITHIN FROST ADVISORY CRITERIA
(CONSIDERING TD VALUES AROUND 33F ADVERTISED BY SHORT RANGE MODEL
CONSENSUS). LOWS ARE CURRENTLY EXPECTED TO BE FROM THE UPPER 30S
IN THE WEST TO NEAR 50 IN THE EAST...SO NO ADVISORY IS CURRENTLY
ANTICIPATED.
.LONG TERM...(TOMORROW THROUGH FRIDAY)
ISSUED AT 1237 PM MDT FRI SEP 27 2013
QUIET WEATHER IS EXPECTED THROUGH AT LEAST MID WEEK AS ZONAL FLOW
BECOMES ESTABLISHED ACROSS THE CENTRAL AND NORTHERN PLAINS. THERE
WILL BE SOME EMBEDDED WEAK DISTURBANCES...BUT THE MAIN STORM TRACK
WILL SHIFT NORTHWARD WITH TIME AND LOW LEVEL MOISTURE WILL BE VERY
LIMITED. THE NEXT FRONTAL PASSAGE MAY OCCUR WEDNESDAY NIGHT AS THE
UPPER FLOW BECOMES MORE SOUTHWEST AHEAD OF A SHORTWAVE TROUGH IN
THE NORTHERN ROCKIES. MODELS ARE IN VERY POOR AGREEMENT AT THIS
TIME...THE ECMWF HAS THE FRONT IN THE DAKOTAS WHILE THE GFS PUSHES
IT THROUGH THE LOCAL AREA WITH A CHANCE OF PRECIPITATION...SO
PREFER TO WAIT FOR BETTER MODEL CONSISTENCY BEFORE COMMITTING TO
POPS. FOR THE LATER PART OF THE WEEK...MODEL CONSISTENCY BECOMES
EVEN WORSE WITH THE ECMWF AND GFS COMPLETELY OUT OF PHASE IN THEIR
UPPER PATTERNS BY FRIDAY. GIVEN THE LOW CONFIDENCE...FORECAST WILL
HEDGE TOWARD NEAR NORMAL TEMPERATURES AND NO MENTION OF PRECIPITATION
AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1149 AM MDT FRI SEP 27 2013
SHOWERS/THUNDERSTORMS WILL CONTINUE TO INCREASE IN COVERAGE AT
BOTH KGLD AND KMCK TERMINALS. WHILE VFR SHOULD PREVAIL...I COULDNT
RULE OUT MVFR OR LOWER CONDITIONS WITH HEAVIER
SHOWERS/THUNDERSTORMS. AT THIS TIME I WAS NOT CONFIDENT ENOUGH TO
ADD MUCH LOWER THAN 6SM VIS WITH SHRA...AND WILL NEED TO
MONITOR/UPDATE BASED ON RADAR/OBS TRENDS THIS AFTERNOON. PRECIP
SHOULD QUICKLY COME TO AN END BEHIND FRONT THIS EVENING. WINDS ARE
CURRENTLY VARIABLE IN PROXIMITY TO FRONT...HOWEVER SHORT RANGE
GUIDANCE CONTINUES TO SHOW SHIFTING/INCREASING WINDS FROM THE
SOUTH AS FRONT LIFTS THIS AFTERNOON. WINDS WILL THEN BACK TO THE
NORTHWEST THIS EVENING AND INCREASE BEHIND COLD FRONT. AS THIS
FRONT MOVES EAST NORTHWEST WINDS SHOULD DECREASE WITH WINDS
FINALLY DROPPING BACK TO AROUND 12KT OR LESS AFTER 09Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY FROM 6 PM MDT /7 PM CDT/ THIS EVENING TO 5 AM MDT
/6 AM CDT/ SATURDAY FOR KSZ001>004-013>016-027>029-041-042.
CO...WIND ADVISORY FROM 6 PM THIS EVENING TO 5 AM MDT SATURDAY FOR
COZ090>092.
NE...WIND ADVISORY FROM 6 PM MDT /7 PM CDT/ THIS EVENING TO 5 AM MDT
/6 AM CDT/ SATURDAY FOR NEZ079>081.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1230 PM MDT FRI SEP 27 2013
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 1230 AM MDT FRI SEP 27 2013
AS OF NOON MDT/1PM CDT...WV IMAGERY AND RAP H5 ANALYSIS SHOW
POSITIVELY TITLED TROUGH EXTENDING FROM NORTHERN ROCKIES ACROSS
THE GREAT BASIN...WITH ITS BASE NEAR THE BAJA PENINSULA. SW FLOW
IS IN PLACE ACROSS THE PLAINS WITH MID LEVEL MOISTURE PLUME
EXTENDING FROM THE PACIFIC OCEAN AND INTO WESTERN KANSAS OVER OUR
CWA. AT THE SURFACE A STATIONARY FRONT IS CURRENTLY EXTENDING FROM
ABOUT LIMON COLORADO...TO GOODLAND KS...AND NORTH INTO CENTRAL
NEBRASKA. LIGHT TO MODERATE SHOWERS HAVE DEVELOPED ALONG THE
LEADING EDGE OF THIS FRONT...WITH RECENT RADAR RETURNS SHOWING AN
INCREASE IN INTENSITY AND COVERAGE.
GUIDANCE CONTINUES TO INDICATE THIS FRONT LIFTING LATER THIS
AFTERNOON WITH INSTABILITY INCREASING EAST OF THE FRONT OVER
WESTERN/CENTRAL KANSAS. FORECAST SEEMS TO BE ON TRACK REGARDING
COVERAGE...WITH LIGHT TO MODERATE SHOWERS AND ISOLATED
THUNDERSTORMS LIKELY THIS AFTERNOON AND EVENING. HOWEVER THERE HAS
BEEN LITTLE INDICATION OF FRONT LIFTING SO FAR...AND UNTIL IT
DOES THUNDERSTORM COVERAGE (AND SEVERE THREAT) IS IN QUESTION.
LATEST RAP SHOWS 600-900 J/KG OF MUCAPE BY AROUND 00Z IN THE EAST
WHICH ISNT PARTICULARLY IMPRESSIVE...THOUGH IT IS WORTH MENTIONING
THAT THE NAM HAS OVER 1500 J/KG OF MU CAPE IN A SIMILAR AREA. THE
DIFFERENCE SEEMS TO BE TIMING/POSITION OF FRONT WITH NAM
QUICKER/FURTHER NORTH. SHEER IS VERY IMPRESSIVE WITH 0-6KM BULK
SHEER 50KT TO 80KT FROM THE EAST TO THE WEST...AND INCREASING
EFFECTIVE SHEER 40-50KT. IF WE CAN GET A STRONG ENOUGH UPDRAFT
(INSTABILITY DEPENDED) IT COULD QUICKLY BECOME SEVERE CONSIDERING
THE SHEER PROFILES. LCLS ARE STILL ADVERTISED AROUND 9-10KFT
WHICH IS PRETTY HIGH FOR A WIDESPREAD TORNADO THREAT...SO
WIND/HAIL/HEAVY RAIN CONTINUE TO BE THE PRIMARY CONCERNS THIS
AFTERNOON AND EVENING.
VERY DRY/SUBSIDENT AIR MASS WILL BUILD IN FROM THE WEST BEHIND A
COLD FRONT THIS EVENING...AND MODELS SUPPORT SHOWERS/THUNDERSTORMS
QUICKLY ENDING FROM WEST TO EAST IN THE 03-06Z PERIOD. I KEPT SOME
CHANCE POPS LINGERING THROUGH 09Z IN THE EAST TO ACCOUNT FOR A
SLOWER FRONTAL EXIT FOR THOSE LOCATIONS...HOWEVER THIS APPEARS TO
BE MAINLY A AFTERNOON/EVENING EVENT. PRECIP AMOUNTS COULD BE VERY
IMPRESSIVE CONSIDERING THE AMOUNT OF FORCING/MOISTURE
ADVERTISED...AND MODEL QPF FORECASTS CONTINUE TO SUPPORT RAINFALL
AMOUNTS FROM ONE QUARTER OF AN INCH IN THE WEST TO NEAR ONE INCH
IN THE NORTHEAST. WITH POSSIBLE TRAINING/BACK BUILDING OF
SHOWERS/THUNDERSTORMS WE WILL NEED TO MONITOR FOR POSSIBLE FLASH
FLOODING.
REGARDING WIND ADVISORY...THERE SHOULD BE A SHARP INCREASE IN
WINDS IMMEDIATELY BEHIND THE COLD FRONT THIS EVENING. LATEST MODELS
HAVE DECREASED THE WINDS ALOFT SOME FROM PREVIOUS GUIDANCE...AND
SPED UP THE FRONTAL PASSAGE. IM STILL CONFIDENT WE WILL SEE A
BRIEF PERIOD OF NEAR ADVISORY TO ABOVE ADVISORY WIND GUSTS THIS
EVENING THROUGH AROUND MIDNIGHT IN THE EAST...SO I DIDNT SEE A
REASON TO CANCEL THE WIND ADVISORY. IT CURRENTLY RUNS THROUGH
12Z...WHICH MANY BE TOO LONG...HOWEVER IT DOES COVER THE
POSSIBILITY OF A SLOWER FROPA IN THE EAST.
WITH CLEARING SKIES AND A VERY COOL/DRY AIR MASS ADVECTING IN FROM
THE WEST AFTER MIDNIGHT WE WILL LIKELY SEE SOME OF THE COOLER TEMPS
SO FAR THIS MONTH. IF WINDS DECREASE BELOW 10KT (WHICH IS NOT
CURRENTLY EXPECTED) WE COULD COOL TO THE LOW TO MID 30S IN THE
WEST WHICH WOULD PUT US WITHIN FROST ADVISORY CRITERIA
(CONSIDERING TD VALUES AROUND 33F ADVERTISED BY SHORT RANGE MODEL
CONSENSUS). LOWS ARE CURRENTLY EXPECTED TO BE FROM THE UPPER 30S
IN THE WEST TO NEAR 50 IN THE EAST...SO NO ADVISORY IS CURRENTLY
ANTICIPATED.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 329 AM MDT FRI SEP 27 2013
MONDAY THROUGH THURSDAY...MODELS ARE PRETTY WELL IN LINE FOR THE
FIRST PART OF THE EXTENDED AND THEN HAVE SOME DIFFERENCES IN THE
TIMING...STRENGTH...AND POSITION OF THE NEXT UPPER TROUGH THAT WILL
MOVE INTO THE ROCKIES AFFECTING THE CWA TOWARDS THE END OF THE
EXTENDED. SHORTWAVE RIDGING WILL TAKE PLACE ON MONDAY...CREATING DRY
CONDITIONS. MODELS START TO HAVE SOME SLIGHT DIFFERENCES ON
TUESDAY...WITH THE GFS SHOWING A SHORTWAVE TROUGH MOVING THROUGH THE
CWA AND THE ECMWF NOT HAVING THIS FEATURE. THE GFS ALSO DID NOT HAVE
THE GREATEST MOISTURE OR SHEAR WITH THE TROUGH...SO WENT DRY FOR
TUESDAY. BY WEDNESDAY...THE ECMWF HAS A SHORTWAVE TROUGH MOVING
THROUGH THE CWA...BUT THE GFS DOES NOT HAVE THIS FEATURE.
HOWEVER...THE GFS DOES HAVE EASTERLY TO SOUTHEASTERLY FLOW BRINGING
IN SOME MOISTURE ALONG WITH INSTABILITY. THEREFORE...BASED ON THE
MOIST UPSLOPE FLOW...WENT WITH SLIGHT CHANCE TO CHANCE POPS.
THURSDAY WAS KEPT DRY...WITH THURSDAY NIGHT HAVING SLIGHT CHANCE
POPS AS THE NEXT UPPER TROUGH AND ASSOCIATED SURFACE LOW PRESSURE
THAT DEVELOPS OVER NORTHEASTERN COLORADO WITH A COLD FRONT APPROACH
THE CWA. WHEN THE MODELS ARE IN BETTER AGREEMENT WITH THE MOVEMENT
OF THE UPPER TROUGH...POPS MAY CHANGE FOR THURSDAY NIGHT. THE TIME
PERIOD OUTSIDE OF THE EXTENDED RANGE SEEMS TO HAVE THE BEST
POPS...BUT WILL HAVE TO WAIT FOR THE NEXT SET OF MODEL RUNS TO SEE
HOW THAT PANS OUT.
TEMPERATURES THROUGH THE EXTENDED WILL REMAIN ABOVE NORMAL...WITH
HIGHS IN THE MID 70S TO LOW 80S AND LOWS IN THE UPPER 40S TO MID
50S. SIGNIFICANT TEMPERATURE CHANGES WILL OCCUR OUTSIDE THE EXTENDED
PERIOD WHEN A COLD FRONT MOVES THROUGH THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1149 AM MDT FRI SEP 27 2013
SHOWERS/THUNDERSTORMS WILL CONTINUE TO INCREASE IN COVERAGE AT
BOTH KGLD AND KMCK TERMINALS. WHILE VFR SHOULD PREVAIL...I COULDNT
RULE OUT MVFR OR LOWER CONDITIONS WITH HEAVIER
SHOWERS/THUNDERSTORMS. AT THIS TIME I WAS NOT CONFIDENT ENOUGH TO
ADD MUCH LOWER THAN 6SM VIS WITH SHRA...AND WILL NEED TO
MONITOR/UPDATE BASED ON RADAR/OBS TRENDS THIS AFTERNOON. PRECIP
SHOULD QUICKLY COME TO AN END BEHIND FRONT THIS EVENING. WINDS ARE
CURRENTLY VARIABLE IN PROXIMITY TO FRONT...HOWEVER SHORT RANGE
GUIDANCE CONTINUES TO SHOW SHIFTING/INCREASING WINDS FROM THE
SOUTH AS FRONT LIFTS THIS AFTERNOON. WINDS WILL THEN BACK TO THE
NORTHWEST THIS EVENING AND INCREASE BEHIND COLD FRONT. AS THIS
FRONT MOVES EAST NORTHWEST WINDS SHOULD DECREASE WITH WINDS
FINALLY DROPPING BACK TO AROUND 12KT OR LESS AFTER 09Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY FROM 6 PM MDT /7 PM CDT/ THIS EVENING TO 5 AM MDT
/6 AM CDT/ SATURDAY FOR KSZ001>004-013>016-027>029-041-042.
CO...WIND ADVISORY FROM 6 PM THIS EVENING TO 5 AM MDT SATURDAY FOR
COZ090>092.
NE...WIND ADVISORY FROM 6 PM MDT /7 PM CDT/ THIS EVENING TO 5 AM MDT
/6 AM CDT/ SATURDAY FOR NEZ079>081.
&&
$$
SHORT TERM...DR
LONG TERM...ALW
AVIATION...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1243 PM CDT Fri Sep 27 2013
...Updated aviation discussion...
.SYNOPSIS...
ISSUED AT 1049 AM CDT FRI SEP 27 2013
At 12z Friday a surface cold front extended from south central
Nebraska into east central Colorado. A tough of low
pressure/dryline was located near the Colorado and extended south
of this cold front into extreme northeast New Mexico. Across
western Kansas surface dewpoints east of the surface lee trough
were mainly in the mid 50s. Surface dewpoints in the low to mid
60s were advecting northward across the panhandle of Texas. At the
700mb level a wedge of higher dewpoints were evident from eastern
New Mexico into northwest Kansas. Weak instability also was
present along this moisture axis based on the North Platte and RAP
proximity soundings. This area outlined the early morning light
precipitation was occurred across far western Kansas. Further west
a -23c 500mb trough was located near the four corners region and a
300mb jet streak extend from just west of this upper trough
north/northeast into southeast Wyoming.
&&
.UPDATE...
ISSUED AT 1049 AM CDT FRI SEP 27 2013
Latest RAP and HRRR suggesting mid level moisture and light
precipitation will persist and slowly move east across across
western through the early afternoon. As the mid levels cool and
upper level dynamics improve...scattered thunderstorms still
appear likely by mid day. One area will be near this mid level
moisture axis which will be located in western Kansas. The other
area will be further west near the Colorado border near the
surface lee trough and along the cold front located in northwest
Kansas. Will therefore adjust precipitation chances accordingly
through the early afternoon to reflect this trend. Strong to
severe thunderstorms still looks on track later this afternoon and
early tonight with hail, strong damaging winds and periods of
heavy rainfall.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 415 AM CDT FRI SEP 27 2013
A busy and challenging next 24 hours is in store, as a rapid
sensible weather change will occur when the Northern Plains cold
front advances across the area later tonight. The very warm
airmass over western Kansas will become undercut by increasing
moisture as dew points increase into the 60`s on southerly surface
moisture transport through the day. Weak to marginally moderate
surface based capes will result by mid afternoon as modeled by the
SREF/WRF models, generally along a 50 mile wide corridor where
surface moisture pooling is enhanced ahead of a surface dryline. A
few fast moving (35-40 knots) right movers could develop before
clusters become linear in nature, presenting more of a convective
wind threat. An initial tornado threat is possible however the
rapid movement and relative parallel upper flow does not tend to
support anything other than very brief or short lived. A
significant and rapid increase in precipitable water to above an
inch and a half will support efficient warm cloud rain processes
as well, and localized flooding may occur with any significant
cell training.
In the meantime, prior to convective development, another breezy day
is expected with southerly winds in the 20 to 30 mph range again
given the persistent gradient. Given a marked increase in jet level
cirrus, an increase in moisture and not and much downslope wind
component, maximum temperatures will be not as hot this afternoon.
Temperatures will be cooler behind the cold front (clearing skies
will support upper 40`s in the western sections) by very early
Saturday morning, with extensive mid level clouds across central
Kansas. A northwest downsloping surface wind factor will likely
preclude any widespread dense fog development despite very cool
temperatures and a moist boundary layer early Saturday.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 323 AM CDT FRI SEP 27 2013
Saturday night will see an exiting cold front down in central
Oklahoma, with a southwesterly flow aloft. This upper level southwest
flow will begin a warm up, with Sunday max temps reaching the 76F
to 78F range. By Tuesday, maximum temperatures will have climbed
in the mid 80s across our southern boundary with Oklahoma, and to
the lower 80s north of I-70. Temperatures will level off in the
lower to mid 80s Wednesday and Thursday. A small upper wave will
transverse into central Kansas Wednesday night, and there will be
a slight chance for a few thunderstorms across our northern 1/3rd
of the forecast area, basically north of highway 156. That upper
wave on Wednesday night will zip to the east or northeast quickly,
and Thursday should be dry. Looking into day 8, or Friday, the
axis of the upper trough comes into play and may bring more
widespread thunderstorm chances to all of southwest and south
central Kansas.
Minimum temperatures will also reflect a warming trend. Sunday
morning should be seasonably cool with lows in the 40s, then minimums
will rise into the middle to upper 50s by Tuesday morning, and
then even warmer to the upper 50s to the middle 60s by Thursday.
After loading the NAM model winds through 60 hours, and the ECMWF
model winds through day 8, the only windy periods appear to be
Sunday/Sunday night, and Wednesday night. It is hard to believe
SW Kansas would go so long without stronger winds, especially
since a surface high pressure is not involved. I suspect wind
speeds will need to be raised by later shifts, especially during
afternoon periods.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1238 PM CDT FRI SEP 27 2013
Gusty south winds at 20 to 25 knots can be expected through the
remainder of the day as surface pressures fall along the lee of
the Rockies. Mid level moisture will spread east across western
Kansas during the afternoon as an upper level trough approaches
the central high plains from the west. Scattered afternoon
thunderstorms are expected to develop across western Kansas with
the better time for convection at any taf site being after 00z given
0-6km shear, moisture, and instability ahead of the upper level
trough. Based on the 12z NAM bufr soundings afternoon and evening
cigs will be at or above 5000ft AGL. The exception will be near
the evening thunderstorms where cigs and/or vsbys will briefly
fall into the IFR category. A cold front will surge south across
western between 04z and 09z. As this front passes the south winds
will shift to the north and increase to near 25kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 52 71 46 / 40 70 10 10
GCK 88 50 70 47 / 50 70 10 0
EHA 84 52 69 46 / 60 70 10 0
LBL 88 53 71 47 / 50 70 10 0
HYS 89 51 71 43 / 20 70 10 10
P28 87 58 75 46 / 10 70 40 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY from 10 PM CDT /9 PM MDT/ this evening to 5 AM CDT
/4 AM MDT/ Saturday FOR KSZ030-043>045-061>064.
&&
$$
UPDATE...Burgert
SYNOPSIS...Burgert
SHORT TERM...Russell
LONG TERM...Burke
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1055 AM CDT Fri Sep 27 2013
...Updated synopsis and updated the afternoon precipitation chances...
.SYNOPSIS...
ISSUED AT 1049 AM CDT FRI SEP 27 2013
At 12z Friday a surface cold front extended from south central
Nebraska into east central Colorado. A tough of low
pressure/dryline was located near the Colorado and extended south
of this cold front into extreme northeast New Mexico. Across
western Kansas surface dewpoints east of the surface lee trough
were mainly in the mid 50s. Surface dewpoints in the low to mid
60s were advecting northward across the panhandle of Texas. At the
700mb level a wedge of higher dewpoints were evident from eastern
New Mexico into northwest Kansas. Weak instability also was
present along this moisture axis based on the North Platte and RAP
proximity soundings. This area outlined the early morning light
precipitation was occurred across far western Kansas. Further west
a -23c 500mb trough was located near the four corners region and a
300mb jet streak extend from just west of this upper trough
north/northeast into southeast Wyoming.
&&
.UPDATE...
ISSUED AT 1049 AM CDT FRI SEP 27 2013
Latest RAP and HRRR suggesting mid level moisture and light
precipitation will persist and slowly move east across across
western through the early afternoon. As the mid levels cool and
upper level dynamics improve...scattered thunderstorms still
appear likely by mid day. One area will be near this mid level
moisture axis which will be located in western Kansas. The other
area will be further west near the Colorado border near the
surface lee trough and along the cold front located in northwest
Kansas. Will therefore adjust precipitation chances accordingly
through the early afternoon to reflect this trend. Strong to
severe thunderstorms still looks on track later this afternoon and
early tonight with hail, strong damaging winds and periods of
heavy rainfall.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 415 AM CDT FRI SEP 27 2013
A busy and challenging next 24 hours is in store, as a rapid
sensible weather change will occur when the Northern Plains cold
front advances across the area later tonight. The very warm
airmass over western Kansas will become undercut by increasing
moisture as dew points increase into the 60`s on southerly surface
moisture transport through the day. Weak to marginally moderate
surface based capes will result by mid afternoon as modeled by the
SREF/WRF models, generally along a 50 mile wide corridor where
surface moisture pooling is enhanced ahead of a surface dryline. A
few fast moving (35-40 knots) right movers could develop before
clusters become linear in nature, presenting more of a convective
wind threat. An initial tornado threat is possible however the
rapid movement and relative parallel upper flow does not tend to
support anything other than very brief or short lived. A
significant and rapid increase in precipitable water to above an
inch and a half will support efficient warm cloud rain processes
as well, and localized flooding may occur with any significant
cell training.
In the meantime, prior to convective development, another breezy day
is expected with southerly winds in the 20 to 30 mph range again
given the persistent gradient. Given a marked increase in jet level
cirrus, an increase in moisture and not and much downslope wind
component, maximum temperatures will be not as hot this afternoon.
Temperatures will be cooler behind the cold front (clearing skies
will support upper 40`s in the western sections) by very early
Saturday morning, with extensive mid level clouds across central
Kansas. A northwest downsloping surface wind factor will likely
preclude any widespread dense fog development despite very cool
temperatures and a moist boundary layer early Saturday.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 323 AM CDT FRI SEP 27 2013
Saturday night will see an exiting cold front down in central
Oklahoma, with a southwesterly flow aloft. This upper level southwest
flow will begin a warm up, with Sunday max temps reaching the 76F
to 78F range. By Tuesday, maximum temperatures will have climbed
in the mid 80s across our southern boundary with Oklahoma, and to
the lower 80s north of I-70. Temperatures will level off in the
lower to mid 80s Wednesday and Thursday. A small upper wave will
transverse into central Kansas Wednesday night, and there will be
a slight chance for a few thunderstorms across our northern 1/3rd
of the forecast area, basically north of highway 156. That upper
wave on Wednesday night will zip to the east or northeast quickly,
and Thursday should be dry. Looking into day 8, or Friday, the
axis of the upper trough comes into play and may bring more
widespread thunderstorm chances to all of southwest and south
central Kansas.
Minimum temperatures will also reflect a warming trend. Sunday
morning should be seasonably cool with lows in the 40s, then minimums
will rise into the middle to upper 50s by Tuesday morning, and
then even warmer to the upper 50s to the middle 60s by Thursday.
After loading the NAM model winds through 60 hours, and the ECMWF
model winds through day 8, the only windy periods appear to be
Sunday/Sunday night, and Wednesday night. It is hard to believe
SW Kansas would go so long without stronger winds, especially
since a surface high pressure is not involved. I suspect wind
speeds will need to be raised by later shifts, especially during
afternoon periods.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 617 AM CDT FRI SEP 27 2013
An upper level wave will move through the plains today, as a surface
cold front travels south-southeast this afternoon and tonight.
Breezy south winds early today will bring in increasing levels of
moisture. As the front encounters the moisture this evening,
severe storm are likely to develop. The main time for strong to
severe storms near the terminals will be between 00z and 04z.
Vsbys could dip to as low as 1/2 mile and cigs to below ovc010.
After the front passes, lingering showers will bring vsbys to near
5sm and cigs ovc004-050.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 87 52 71 46 / 40 70 10 10
GCK 88 50 70 47 / 50 70 10 0
EHA 84 52 69 46 / 60 70 10 0
LBL 88 53 71 47 / 50 70 10 0
HYS 89 51 71 43 / 20 70 10 10
P28 87 58 75 46 / 10 70 40 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY from 10 PM CDT /9 PM MDT/ this evening to 5 AM CDT
/4 AM MDT/ Saturday FOR KSZ030-043>045-061>064.
&&
$$
UPDATE...Burgert
SYNOPSIS...Burgert
SHORT TERM...Russell
LONG TERM...Burke
AVIATION...Burke
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
117 PM EDT Fri Sep 27 2013
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1038 AM EDT Fri Sep 27 2013
Now that the dense fog is just about gone we`ll send out a new ZFP
and HWO to reflect that. The forecast is in good shape...only tweak
right now is to bump temps west of I-65 up one degree for MaxT this
afternoon.
.SHORT TERM (Now through Saturday)...
Issued at 245 AM EDT Fri Sep 27 2013
Ridge axis north/northeast of a strong upper high over the LA coast
will continue to keep subsidence over our area this period. Thus we
can expect temperatures a little warmer each day. Especially as
winds veer around from light easterly today to stronger
southwesterly Saturday, as a cold front starts getting closer to our
region.
Valley fog should become a nuisance around daybreak. Area webcams
are not yet showing any widespread issues in our forecast area at
this time. Latest HRRR continues to insist on our northeast area
getting some denser fog by daybreak. Have areas of fog in that
region in the forecast already but still think portions of south
central KY have a shot based on how high their dewpoints stayed
yesterday afternoon. We`ll be a little warmer and more moist
Saturday morning, so should have similar conditions tomorrow, but
for now will limit to patchy fog.
.LONG TERM (Saturday Night through Thursday)...
Issued at 250 AM EDT Fri Sep 27 2013
The highly amplified upper-level ridge that will stretched from the
Gulf of Mexico northeast across the Ohio Valley Saturday will break
down Saturday night, as a shortwave trough pushes into the western
Great Lakes. This trough will swing through the Great Lakes Sunday,
with an associated surface low dragging a cold front through the
Ohio Valley. Scattered showers and a few embedded rumbles of thunder
will move into southern Indiana and central Kentucky through much of
the day Sunday. Should see a slight decrease in areal coverage as
the precip pushes east into east-central Kentucky, as the front will
be moving into drier air and will also become disassociated with the
upper-level forcing Sunday evening. Rain showers will gradually
diminish across central Kentucky Sunday night and our southeast
forecast area through the first half of Monday. If the boundary
becomes far removed from the upper-level forcing than currently
forecast, precip chances might linger across more of the area Monday
as the front slows. Will continue to monitor trends. Otherwise,
rainfall totals of generally a third of an inch along the Ohio River
as well as west of I-65 in central Kentucky are possible, with
lesser amounts further east.
With the frontal boundary losing the upper-level forcing, it will
continue to weaken and wash out from roughly the upper Ohio Valley
southwest into the Tennessee Valley Monday through Tuesday. Aloft,
weak ridging will fill in over our area behind the departed trough,
producing a weak subsidence inversion late Monday through Thursday.
Cannot rule out a very isolated shower or storm, mainly across
south-central Kentucky, but currently believe capped afternoon
cumulus will be more common. So, will keep the forecast dry Monday
night through Thursday.
As for temperatures, highs will generally hold in the lower 70s
Sunday with clouds and precip across the area. Temperatures will
gradually moderate through the week, with highs ranging from the
upper 70s to lower 80s for both Wednesday and Thursday afternoon.
Overnight lows will range from the middle 50s to lower 60s.
&&
.AVIATION (18Z TAF Update)...
Issued at 116 PM EDT Fri Sep 27 2013
High pressure crossing New England and ridging back to the Gulf of
Mexico will keep our weather quiet through the TAF period. Despite
the occurrence of fog the past couple of mornings, fog tonight is
still a question mark. We`ll have a very similar synoptic set-up
tonight as the past couple of nights. However we`ll have had
another day of drying and the trend from yesterday morning to this
morning has been a decrease in fog coverage. Model data indicate
some moisture around 850hPa as well as some cirrus streaming in from
the Plains by Saturday morning. Also, models that did an excellent
job predicting this morning`s fog are forecasting little if any (at
the TAF sites) tomorrow morning. So, bottom line, will bring in
some light fog but for now won`t bring vsbys down as far as they
went this morning.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........13
Short Term.....RJS
Long Term......MJP
Aviation.......13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1038 AM EDT Fri Sep 27 2013
...Forecast Update...
Issued at 1038 AM EDT Fri Sep 27 2013
Now that the dense fog is just about gone we`ll send out a new ZFP
and HWO to reflect that. The forecast is in good shape...only tweak
right now is to bump temps west of I-65 up one degree for MaxT this
afternoon.
.SHORT TERM (Now through Saturday)...
Issued at 245 AM EDT Fri Sep 27 2013
Ridge axis north/northeast of a strong upper high over the LA coast
will continue to keep subsidence over our area this period. Thus we
can expect temperatures a little warmer each day. Especially as
winds veer around from light easterly today to stronger
southwesterly Saturday, as a cold front starts getting closer to our
region.
Valley fog should become a nuisance around daybreak. Area webcams
are not yet showing any widespread issues in our forecast area at
this time. Latest HRRR continues to insist on our northeast area
getting some denser fog by daybreak. Have areas of fog in that
region in the forecast already but still think portions of south
central KY have a shot based on how high their dewpoints stayed
yesterday afternoon. We`ll be a little warmer and more moist
Saturday morning, so should have similar conditions tomorrow, but
for now will limit to patchy fog.
.LONG TERM (Saturday Night through Thursday)...
Issued at 250 AM EDT Fri Sep 27 2013
The highly amplified upper-level ridge that will stretched from the
Gulf of Mexico northeast across the Ohio Valley Saturday will break
down Saturday night, as a shortwave trough pushes into the western
Great Lakes. This trough will swing through the Great Lakes Sunday,
with an associated surface low dragging a cold front through the
Ohio Valley. Scattered showers and a few embedded rumbles of thunder
will move into southern Indiana and central Kentucky through much of
the day Sunday. Should see a slight decrease in areal coverage as
the precip pushes east into east-central Kentucky, as the front will
be moving into drier air and will also become disassociated with the
upper-level forcing Sunday evening. Rain showers will gradually
diminish across central Kentucky Sunday night and our southeast
forecast area through the first half of Monday. If the boundary
becomes far removed from the upper-level forcing than currently
forecast, precip chances might linger across more of the area Monday
as the front slows. Will continue to monitor trends. Otherwise,
rainfall totals of generally a third of an inch along the Ohio River
as well as west of I-65 in central Kentucky are possible, with
lesser amounts further east.
With the frontal boundary losing the upper-level forcing, it will
continue to weaken and wash out from roughly the upper Ohio Valley
southwest into the Tennessee Valley Monday through Tuesday. Aloft,
weak ridging will fill in over our area behind the departed trough,
producing a weak subsidence inversion late Monday through Thursday.
Cannot rule out a very isolated shower or storm, mainly across
south-central Kentucky, but currently believe capped afternoon
cumulus will be more common. So, will keep the forecast dry Monday
night through Thursday.
As for temperatures, highs will generally hold in the lower 70s
Sunday with clouds and precip across the area. Temperatures will
gradually moderate through the week, with highs ranging from the
upper 70s to lower 80s for both Wednesday and Thursday afternoon.
Overnight lows will range from the middle 50s to lower 60s.
&&
.AVIATION (12Z TAF Update)...
Issued at 645 AM EDT Fri Sep 27 2013
Clear conditions and residual low-level moisture early this morning
have allowed patchy dense fog to form across portions of central KY.
Thanks to some drier air mixing down yesterday afternoon, the fog is
not as dense as 24-hours ago. Will continue with temporary vis/cig
restrictions at LEX and BWG to start the period. Otherwise, expect
VFR conditions as high pressure aloft will keep the region quiet
weather-wise. A weak inverted trough may provide focus for a few
lower clouds over south-central KY this afternoon. Could see a
return of patchy fog near daybreak Saturday, but low-level moisture
should dry out some more this afternoon. So, confidence is too low
for inclusion in this TAF issuance.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........13
Short Term.....RJS
Long Term......MJP
Aviation.......MJP
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
647 AM EDT Fri Sep 27 2013
...Updated Aviation Discussion...
.SHORT TERM (Now through Saturday)...
Issued at 245 AM EDT Fri Sep 27 2013
Ridge axis north/northeast of a strong upper high over the LA coast
will continue to keep subsidence over our area this period. Thus we
can expect temperatures a little warmer each day. Especially as
winds veer around from light easterly today to stronger
southwesterly Saturday, as a cold front starts getting closer to our
region.
Valley fog should become a nuisance around daybreak. Area webcams
are not yet showing any widespread issues in our forecast area at
this time. Latest HRRR continues to insist on our northeast area
getting some denser fog by daybreak. Have areas of fog in that
region in the forecast already but still think portions of south
central KY have a shot based on how high their dewpoints stayed
yesterday afternoon. We`ll be a little warmer and more moist
Saturday morning, so should have similar conditions tomorrow, but
for now will limit to patchy fog.
.LONG TERM (Saturday Night through Thursday)...
Issued at 250 AM EDT Fri Sep 27 2013
The highly amplified upper-level ridge that will stretched from the
Gulf of Mexico northeast across the Ohio Valley Saturday will break
down Saturday night, as a shortwave trough pushes into the western
Great Lakes. This trough will swing through the Great Lakes Sunday,
with an associated surface low dragging a cold front through the
Ohio Valley. Scattered showers and a few embedded rumbles of thunder
will move into southern Indiana and central Kentucky through much of
the day Sunday. Should see a slight decrease in areal coverage as
the precip pushes east into east-central Kentucky, as the front will
be moving into drier air and will also become disassociated with the
upper-level forcing Sunday evening. Rain showers will gradually
diminish across central Kentucky Sunday night and our southeast
forecast area through the first half of Monday. If the boundary
becomes far removed from the upper-level forcing than currently
forecast, precip chances might linger across more of the area Monday
as the front slows. Will continue to monitor trends. Otherwise,
rainfall totals of generally a third of an inch along the Ohio River
as well as west of I-65 in central Kentucky are possible, with
lesser amounts further east.
With the frontal boundary losing the upper-level forcing, it will
continue to weaken and wash out from roughly the upper Ohio Valley
southwest into the Tennessee Valley Monday through Tuesday. Aloft,
weak ridging will fill in over our area behind the departed trough,
producing a weak subsidence inversion late Monday through Thursday.
Cannot rule out a very isolated shower or storm, mainly across
south-central Kentucky, but currently believe capped afternoon
cumulus will be more common. So, will keep the forecast dry Monday
night through Thursday.
As for temperatures, highs will generally hold in the lower 70s
Sunday with clouds and precip across the area. Temperatures will
gradually moderate through the week, with highs ranging from the
upper 70s to lower 80s for both Wednesday and Thursday afternoon.
Overnight lows will range from the middle 50s to lower 60s.
&&
.AVIATION (12Z TAF Update)...
Issued at 645 AM EDT Fri Sep 27 2013
Clear conditions and residual low-level moisture early this morning
have allowed patchy dense fog to form across portions of central KY.
Thanks to some drier air mixing down yesterday afternoon, the fog is
not as dense as 24-hours ago. Will continue with temporary vis/cig
restrictions at LEX and BWG to start the period. Otherwise, expect
VFR conditions as high pressure aloft will keep the region quiet
weather-wise. A weak inverted trough may provide focus for a few
lower clouds over south-central KY this afternoon. Could see a
return of patchy fog near daybreak Saturday, but low-level moisture
should dry out some more this afternoon. So, confidence is too low
for inclusion in this TAF issuance.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........RJS
Long Term.........MJP
Aviation..........MJP
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
256 AM EDT Fri Sep 27 2013
.SHORT TERM (Now through Saturday)...
Issued at 245 AM EDT Fri Sep 27 2013
Ridge axis north/northeast of a strong upper high over the LA coast
will continue to keep subsidence over our area this period. Thus we
can expect temperatures a little warmer each day. Especially as
winds veer around from light easterly today to stronger
southwesterly Saturday, as a cold front starts getting closer to our
region.
Valley fog should become a nuisance around daybreak. Area webcams
are not yet showing any widespread issues in our forecast area at
this time. Latest HRRR continues to insist on our northeast area
getting some denser fog by daybreak. Have areas of fog in that
region in the forecast already but still think portions of south
central KY have a shot based on how high their dewpoints stayed
yesterday afternoon. We`ll be a little warmer and more moist
Saturday morning, so should have similar conditions tomorrow, but
for now will limit to patchy fog.
.LONG TERM (Saturday Night through Thursday)...
Issued at 250 AM EDT Fri Sep 27 2013
The highly amplified upper-level ridge that will stretched from the
Gulf of Mexico northeast across the Ohio Valley Saturday will break
down Saturday night, as a shortwave trough pushes into the western
Great Lakes. This trough will swing through the Great Lakes Sunday,
with an associated surface low dragging a cold front through the
Ohio Valley. Scattered showers and a few embedded rumbles of thunder
will move into southern Indiana and central Kentucky through much of
the day Sunday. Should see a slight decrease in areal coverage as
the precip pushes east into east-central Kentucky, as the front will
be moving into drier air and will also become disassociated with the
upper-level forcing Sunday evening. Rain showers will gradually
diminish across central Kentucky Sunday night and our southeast
forecast area through the first half of Monday. If the boundary
becomes far removed from the upper-level forcing than currently
forecast, precip chances might linger across more of the area Monday
as the front slows. Will continue to monitor trends. Otherwise,
rainfall totals of generally a third of an inch along the Ohio River
as well as west of I-65 in central Kentucky are possible, with
lesser amounts further east.
With the frontal boundary losing the upper-level forcing, it will
continue to weaken and wash out from roughly the upper Ohio Valley
southwest into the Tennessee Valley Monday through Tuesday. Aloft,
weak ridging will fill in over our area behind the departed trough,
producing a weak subsidence inversion late Monday through Thursday.
Cannot rule out a very isolated shower or storm, mainly across
south-central Kentucky, but currently believe capped afternoon
cumulus will be more common. So, will keep the forecast dry Monday
night through Thursday.
As for temperatures, highs will generally hold in the lower 70s
Sunday with clouds and precip across the area. Temperatures will
gradually moderate through the week, with highs ranging from the
upper 70s to lower 80s for both Wednesday and Thursday afternoon.
Overnight lows will range from the middle 50s to lower 60s.
&&
.AVIATION (06Z TAF Update)...
Issued at 110 AM EDT Fri Sep 27 2013
High pressure aloft will keep the region quiet weather-wise. A weak
inverted trough may provide focus for a few lower clouds over south
central KY this afternoon. Clear conditions early this morning may
allow for denser fog to form across portions of central KY. TAF
sites had some drier air mix down Thursday afternoon, which may keep
them from going as foggy as KLEX and KBWG went yesterday. Thus have
gone a little more optimistic for those sites, but still have
periods of IFR conditions around daybreak.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........RJS
Long Term.........MJP
Aviation..........RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
110 AM EDT Fri Sep 27 2013
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1225 AM EDT Fri Sep 27 2013
Latest HRRR coming in with some fog over my northeast sections.
Satellite fog product shows the East KY valleys starting to fill in.
In addition, a quick look at yesterday`s min dewpoints shows that
our eastern and southern counties have the best chance to reach
their crossover temperatures, based on forecast lows. With this in
mind have expanded the fog some north and west and gone up to areas
of fog for the coverage. Will monitor area webcams and obs overnight
to see if more dense wording/SPS/NPW`s are needed.
.SHORT TERM (Now through Friday Night)...
Issued at 236 PM EDT Thu Sep 26 2013
Quiet weather is in store across the Ohio Valley through Friday
night as high pressure at the surface and aloft remains in control.
The only real concern during this time frame will be fog potential
again across south central Kentucky. Not as impressed as last
night`s set up since drier air is working in from the northeast.
Will just mention patchy fog across south central Kentucky and
monitor trends through the evening.
Otherwise, expect mostly sunny/clear skies to end the week with a
light easterly wind. Expect low to range mainly in the mid to upper
50s in most spots tonight, with lower 50s possible in the cool
spots. Friday will bring a slight warm up from today, with highs
topping out in the 78-83 range. Friday night will be similar to
tonight, with lows mainly in the mid and upper 50s again. The cool
spots will be in the low 50s.
.LONG TERM (Saturday through Thursday)...
Issued at 245 PM EDT Thu Sep 26 2013
A strong upper level ridge will be in place Sat causing dry
conditions and high temperatures in the lower 80s.
Sat night a cold front will approach from the WNW breaking down the
ridge and bringing precipitation into our area Sun morning. The
front will weaken as it approaches our area due to the parent low
pushing much farther NE into Canada and also since the front will
have been pushing up against a strong ridge over us Sat night. By
the time rains arrive Sun, looks like they will be in the form of a
broken line of showers with embedded t-storms. Expect QPF amounts
of less than a third of an inch as convection moves through the area
Sun/Sun night. The latest model guidance indicates that the line
will break up more and dry out a bit as it moves eastward so expect
the better rainfall amounts to be west of I-65 with lesser amounts
east of I-65.
Rains should quickly move out of the area Monday morning with mostly
clear skies expected by Mon afternoon. The forecast becomes much
more uncertain for the middle of next week as the remnants of the
cold front become a weak boundary and settle over the Ohio Valley
Mon/Tues/Wed. Weak ridging aloft will be in place causing a weak
inversion and subsidence. Some models indicate the possibility of
showery activity Tues-Wed, however, they may be a bit optimistic.
Therefore will continue a dry forecast through Thurs.
Temperatures for next week will start out in the lower 70s on
Sun...increasing to the mid 70s for Mon/Tues and then upper 70s to
around 80 for Wed/Thurs. Low temperatures will range throughout the
upper 50s and lower 60s next week.
&&
.AVIATION (06Z TAF Update)...
Issued at 110 AM EDT Fri Sep 27 2013
High pressure aloft will keep the region quiet weather-wise. A weak
inverted trough may provide focus for a few lower clouds over south
central KY this afternoon. Clear conditions early this morning may
allow for denser fog to form across portions of central KY. TAF
sites had some drier air mix down Thursday afternoon, which may keep
them from going as foggy as KLEX and KBWG went yesterday. Thus have
gone a little more optimistic for those sites, but still have
periods of IFR conditions around daybreak.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....BJS
Long Term......AMS
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1228 AM EDT Fri Sep 27 2013
...Forecast Update...
Issued at 1225 AM EDT Fri Sep 27 2013
Latest HRRR coming in with some fog over my northeast sections.
Satellite fog product shows the East KY valleys starting to fill in.
In addition, a quick look at yesterday`s min dewpoints shows that
our eastern and southern counties have the best chance to reach
their crossover temperatures, based on forecast lows. With this in
mind have expanded the fog some north and west and gone up to areas
of fog for the coverage. Will monitor area webcams and obs overnight
to see if more dense wording/SPS/NPW`s are needed.
.SHORT TERM (Now through Friday Night)...
Issued at 236 PM EDT Thu Sep 26 2013
Quiet weather is in store across the Ohio Valley through Friday
night as high pressure at the surface and aloft remains in control.
The only real concern during this time frame will be fog potential
again across south central Kentucky. Not as impressed as last
night`s set up since drier air is working in from the northeast.
Will just mention patchy fog across south central Kentucky and
monitor trends through the evening.
Otherwise, expect mostly sunny/clear skies to end the week with a
light easterly wind. Expect low to range mainly in the mid to upper
50s in most spots tonight, with lower 50s possible in the cool
spots. Friday will bring a slight warm up from today, with highs
topping out in the 78-83 range. Friday night will be similar to
tonight, with lows mainly in the mid and upper 50s again. The cool
spots will be in the low 50s.
.LONG TERM (Saturday through Thursday)...
Issued at 245 PM EDT Thu Sep 26 2013
A strong upper level ridge will be in place Sat causing dry
conditions and high temperatures in the lower 80s.
Sat night a cold front will approach from the WNW breaking down the
ridge and bringing precipitation into our area Sun morning. The
front will weaken as it approaches our area due to the parent low
pushing much farther NE into Canada and also since the front will
have been pushing up against a strong ridge over us Sat night. By
the time rains arrive Sun, looks like they will be in the form of a
broken line of showers with embedded t-storms. Expect QPF amounts
of less than a third of an inch as convection moves through the area
Sun/Sun night. The latest model guidance indicates that the line
will break up more and dry out a bit as it moves eastward so expect
the better rainfall amounts to be west of I-65 with lesser amounts
east of I-65.
Rains should quickly move out of the area Monday morning with mostly
clear skies expected by Mon afternoon. The forecast becomes much
more uncertain for the middle of next week as the remnants of the
cold front become a weak boundary and settle over the Ohio Valley
Mon/Tues/Wed. Weak ridging aloft will be in place causing a weak
inversion and subsidence. Some models indicate the possibility of
showery activity Tues-Wed, however, they may be a bit optimistic.
Therefore will continue a dry forecast through Thurs.
Temperatures for next week will start out in the lower 70s on
Sun...increasing to the mid 70s for Mon/Tues and then upper 70s to
around 80 for Wed/Thurs. Low temperatures will range throughout the
upper 50s and lower 60s next week.
&&
.AVIATION (00Z TAF Update)...
ISSUED AT 650 PM EDT THU SEP 26 2013
High pressure will remain in control at the surface and aloft
through tomorrow. Winds will be light and variable to calm
overnight, becoming easterly around 5 knots tomorrow. Skies will be
mostly clear with just a few to scattered clouds. Fog may become an
issue at BWG again tonight. The latest guidance has backed off
somewhat on the fog possibility, but there may be enough low level
moisture remaining to push visibilities down into th LIFR range
towards dawn. LEX could see some light fog, while SDF is expected to
remain VFR through the TAF period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....BJS
Long Term......AMS
Aviation.......EER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
116 AM EDT FRI SEP 27 2013
.SYNOPSIS...
LOW PRESSURE SOUTHEAST OF NOVA SCOTIA WILL SLOWLY MOVE EAST THIS
EVENING AND ALLOW A LARGE RIDGE OF HIGH PRESSURE TO BUILD INTO
OUR REGION THROUGH THE WEEKEND.&&
.NEAR TERM /THROUGH TODAY/...
UPDATE 0110L: CLDS PERSIST ACROSS THE FA W/ CLRG JUST N AND NW OF
THE AREA. HIGH PRES CONTS TO SLOWLY BUILD EWRD AND STILL EXPECT
CLDS TO BEGIN TO DCRS FROM N-S THRU THE OVRNGT HRS. HAVE ADJUSTED
SKY GRIDS TO BETTER FIT CURRENT AND EXPECTED TRENDS AND ADJUSTED
HRLY TEMPS WHICH ARE RUNNING A BIT WARMER THAN FCST ACROSS THE N.
934 PM UPDATE...THE LATEST SATELLITE IMAGES AND OBSERVATIONS
CONTINUE TO SHOW CONSIDERABLE CLOUD COVER ACROSS THE CWA WITH
CEILINGS MOSTLY AROUND 4K FT AGL. THERE ARE A FEW BREAKS SHOWING
UP ACROSS THE CROWN OF MAINE. THE 00Z KCAR SOUNDING WAS LITTLE
CHANGED FROM 24 HOURS AGO WITH SIGNIFICANT MOISTURE PRESENT BELOW
750 MILLIBARS. AS HIGH PRESSURE CONTINUES TO BUILD ACROSS THE
REGION OVERNIGHT THE SUBSIDENCE ALOFT SHOULD ALLOW FOR SOME VERY
SLOW CLEARING FROM NORTH TO SOUTH. THE MAIN UPDATE WAS TO ONCE
AGAIN SLOW THE CLEARING BY A FEW HOURS...MAINLY ACROSS THE NORTH.
THE SOUTHERN HALF OF THE CWA WILL LIKELY REMAIN M/CLOUDY THROUGH
EARLY FRI MORNING.
631 PM UPDATE... THERE ARE A COUPLE OF BREAKS IN THE CLOUDS IN
PARTS OF AROOSTOOK AND PISCATAQUIS COUNTIES. OTHERWISE...MOST
AREAS ARE STILL OVC035. THE TIME HEIGHT FROM BOTH THE NAM AND GFS
INDICATE A LOT OF MOISTURE BELOW 750 MILLIBARS TONIGHT...AND IT
MAY BE VERY TOUGH TO GET RID OF THE CLOUDS UNTIL VERY LATE TONIGHT
OR EARLY FRIDAY MORNING. THE HRRR APPEARS WAY TOO QUICK TO ERODE
THE CLOUDS THIS EVENING. THE MAIN UPDATE WAS TO SLOW THE CLEARING
BY A FEW HOURS THIS EVENING ACROSS THE NORTHERN HALF OF THE CWA.
PREVIOUS DISCUSSION...
HIGH PRESSURE BUILDS OVERNIGHT WITH CLEARING SKIES ADVECTING FROM
THE CROWN OF MAINE SOUTHWARD TOWARDS BANGOR BY LATE NIGHT. LOWS
WILL RANGE FROM NEAR 40F IN THE SJV TO THE UPPER 40S FOR DOWN EAST
AND BANGOR WHERE CLOUDS WILL LINGER. THE LAST OF THE CLOUDS WILL MOVE
SOUTHWARD OUT OF THE FORECAST AREA FRIDAY MORNING. THIS WILL
PRODUCE A SUNNY DAY WITH SOME FAIR WEATHER CUMULUS AND HIGHS
REACHING THE UPPER 60S TO LOW 70S.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
DRY WEATHER PATTERN AND MILDER RIGHT THROUGH THIS TERM.
A LARGE RIDGE OF HIGH PRES WILL MOVE INTO THE CWA OVER THE WEEKEND
PROVIDING A WELL NEEDED STRETCH OF DRY WEATHER AND ABOVE NORMAL
TEMPERATURES. DECIDED ON A BLEND OF THE EMCWFMOS/BCMOS FOR MIN
TEMPERATURES FRIDAY NIGHT AND AGAIN SATURDAY NIGHT. FRIDAY NIGHT
WILL BE THE COOLEST OF THE 2 W/OVERNIGHT LOWS EXPECTED IN THE
UPPER 30S TO LOWER 40S. DAYTIME HIGHS WILL BE ABOVE NORMAL FOR
LATE SEPTEMBER. DECIDED ON A BLEND OF THE BCMOS AND GMOS SHOWING
READINGS EXPECTED TO HIT THE 70S FOR JUST ABOUT THE ENTIRE CWA.
THE COAST COULD BE A FEW DEGREES COOLER GIVEN THE POTENTIAL FOR A
SEA BREEZE AND WEAK ON SHORE WIND.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE FCST LOOKS TO CONTINUE ON THE DRY SIDE W/THE ONLY DISRUPTION
BEING A SUB-TROPICAL LOW MOVING UP FROM THE BERMUDA AREA GIVING A
GLANCING BLOW MAINLY TO THE IMMEDIATE COAST/OUTER ISLAND. THE
TIME FRAME FOR THIS WOULD BE MONDAY NIGHT INTO TUESDAY. THE 12Z
ECMWF RUN MATCHED UP W/ITS 00Z RUN OF BRINGING THE SUB-TROPICAL
SYSTEM MME AND PASSING THE EAST OF NOVA SCOTIA. IF SCENARIO WERE
TO TAKE PLACE, THE OUTER BANDS OF PRECIPITATION WOULD SKIRT THE
IMMEDIATE COAST AND THE OUTER ISLANDS. THE 12Z RUN OF THE GFS AND
GEM GLOBAL KEEP THE LOW FURTHER SOUTH AND EAST W/THE NEW ENGLAND
REGION STAYING ON THE DRY SIDE. ATTM, DECIDED TO USE A BLEND OF ALL
3 AS SOME THE GFS ENSEMBLE MEMBERS SHOW A TRACK SIMILAR TO THE
ECMWF. THEREFORE, KEPT THE MAJORITY OF THE CWA DRY INTO TUESDAY AND
HUNG ON TO A 20-30% CHC FOR RAIN ALONG THE IMMEDIATE COAST AND THE
OUTER ISLANDS MONDAY NIGHT INTO TUESDAY. WEDNESDAY AND THURSDAY
APPEAR TO BE DRY AS HIGH PRES RE-ESTABLISHES ITSELF OVER THE
NORTHEASTERN US.
DAYTIME TEMPERATURES WILL CONTINUE TO BE AOA NORMAL. DECIDED TO
BLEND THE BCMOS INCLUDING THE ECMWF FOR THE OVERNIGHT LOWS AS THE
GMOS TEMPERATURES LOOK TO BE TOO COLD GIVEN THE ESTABLISHED
PATTERN IN PLACE.
&&
.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: MOSTLY OVC040 AT THE TAF SITES THIS EVENING. THE
NORTHERN TAF SITES SHOULD REMAIN VFR WITH THE CLOUDS BECOMING SCT
OVERNIGHT. PATCHY FOG IS POSSIBLE IN THE SJV AND COULD IMPACT THE
KFVE TERMINAL FROM 08-13Z. KBGR AND KBHB WILL LIKELY REMAIN VFR
BUT MAY BRIEFLY GO BACK DOWN TO MVFR FOR A TIME OVERNIGHT. VFR AND
LIGHT WIND EXPECTED AT ALL TERMINALS FRI.
SHORT TERM: VFR RUNNING RIGHT INTO MONDAY.
&&
.MARINE...
NEAR TERM: LIGHT WINDS UNDER 15 KTS AND SEAS MOSTLY AROUND 2 FT ON
THE COASTAL WATERS AND 1 FOOT ON THE INTRA-COASTAL WATERS THROUGH
THE PERIOD.
SHORT TERM: NO HEADLINES EXPECTED. AS WINDS ADD SEAS ARE FCST TO
REMAIN BELOW SCA THRESHOLDS. WE AREA TALKING WINDS OF 10 KTS RIGHT
INTO MONDAY. THERE IS THE POTENTIAL FOR A SWELL TO BE GENERATED BY
MONDAY FROM THE LOW APCHG FROM THE S. ADJUSTED THE WAVE HEIGHTS TO
ACCOUNT FOR THIS POSSIBILITY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...KHW/CB/MCW
SHORT TERM...FITZSIMMONS
LONG TERM...FITZSIMMONS
AVIATION...KHW
MARINE...KHW/CB/MCW/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1002 AM EDT FRI SEP 27 2013
.SYNOPSIS...
HIGH PRESSURE OVER QUEBEC WILL BUILD SOUTHWARD INTO THE MID-ATLANTIC
REGION TODAY...AND REMAIN ALONG THE EASTERN SEABOARD THROUGH THE WEEKEND
INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
WE`VE DONE A COUPLE OF UPDATES THIS MRNG TO INCRS CLD CVR IN THE ERN
1/2 OF THE FCST AREA. 12Z IAD AND APG SNDGS ALONG W/ STLT IMGRY
PLAYED LARGE PARTS IN THIS. THE SYNOPTIC SITUATION LENDS ITSELF TO
CAD IN THE MID ATLC. THE AREA OF CLDS IS FAIRLY SMALL...BUT OVR A
HEAVILY POPULATED AREA. THERE ARE MANY CASES WHERE ONCE INTO A
CAD EVENT IT TAKES MULTIPLE DAYS FOR THE CLDS TO BRK...AND MDLS
HV NEVER DONE A GRT JOB AT FCSTG AT FCSTG CAD DISSIPATION. SINCE
THIS IS SUCH A SMALL AREA OF CLDS - THERE APPEARS TO BE SOME SWD
MVMT TO THESE...AND HRRR SHOWS CLDS MOVG OUT WE`LL KEEP CLDS OVR
THE ERN PART OF THE CWA DURG THE DAY THEN DIMINISHING TNGT. HIGHS
IN THE L70S.
TEMPS WEST OF THE BLUE RIDGE ARE EXPECTED TO REACH THE LM 40S
TONIGHT WHEREAS EAST AND NEAR THE WATER TEMPS SHOULD ONLY DIP INTO
THE 50S.
TEMPS WILL BE MODERATED BY THE ONSHORE FLOW AND WILL BE A FEW
DEGREES LOWER THAN THURSDAY. SOME CLEARING WILL MOVE IN BEHIND
CLOUDS THIS EVENING BUT MOISTURE IS STILL FCST IN SOUNDINGS FOR
OVERNIGHT.
&&
.SHORT TERM /SATURDAY/...
SFC HIGH PRESSURE WILL MOVE OVER NEW ENGLAND BY SATURDAY AFTERNOON
WITH N-NE WINDS CONTINUING INTO THE EVENING. 5K FEET CU FIELD SHOULD
DEVELOP SAT AFTERNOON.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A HIGHLY AMPLIFIED H5 PTTN WL EXIST ACRS THE ERN SEABRD SAT
NGT-SUN...AS L/WV RDG AXIS FM GLFMEX TO NEW ENGLND TILTS IN RESPONSE
TO DPNG LOPRES IN THE WRN ATLC. ALTHO THE AMPLITUDE OF THE RDGG WL
BE PINCHED OFF DUE TO WLYS ACRS CNDA...SUBSIDENCE WL REMAIN ACRS THE
MID ATLC. THEREFORE...WL BE PRESERVING PRVS /DRY/ FCST FOR THE PD.
SKIES SHUD BE MOSUN BY DAY AND MOCLR BY NGT. TEMPS WL BE COMPARABLE
TO SAT...BUT NELY FLOW MAY KEEP MAXT A DEGF OR TWO COOLER ALONG THE
WRN SHORE OF THE BAY.
A WK CDFNT WL APPROACH SUN NGT-MON...BUT THE OCEAN LOW WL TRAP
MID-ULVL RDG IN PLACE ALONG/E OF THE APLCNS...WHICH IN TURN WL
HASTEN THE DSPTN OF THE FNT. WL BE REMOVING POPS FM THE FCST DURING
THIS PD...BUT WL KEEP AN EWD SPREAD OF BKN CLDS.
IN THE WAKE OF THESE FEATURES...BROAD RDGG WL RETURN TO MUCH OF THE
CONUS THROUGH THE MIDDLE OF NXT WK-- CERTAINLY THE CENTRL AND ERN
CONUS. THIS WL SUPPORT MAXT AOA 80F ONCE AGN E OF THE BLURDG. DEWPTS
WL BE SLGTLY HIER TOO...WHICH WL CARRY OVER TO NEAR NORMAL MIN-T.
STILL NO RAIN XPCTD FOR THE DURATION OF THE 7-DAY FCST.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
5-7K FT STRATUS DECK IS MOVING SW THROUGH THE MID ATLANTIC TDA.
CLDS XPCTD TO DIMINISH TNGT.
SUN-THU...VFR. LGT WNDS.
&&
.MARINE...
HIGH PRESSURE WILL CONTINUE ACROSS THE WATERS THROUGH SATURDAY. NE
WINDS SHOULD STAY BELOW SCA CRITERIA TODAY AND TONIGHT. PRESSURE
GRADIENT DOES TIGHTEN SATURDAY AND A FEW 18 KT GUSTS WILL BE
POSSIBLE FOR THE LOWER TIDAL POTOMAC...TANGIER SOUND AND SOUTH OF
DRUM PT. FORECAST WINDS WILL BE KEPT BELOW SCA.
A RDG OF HIPRES ALONG THE EAST COAST WL CONTROL THE WX FOR THE
OUTLOOK PD. XPCT ELY FLOW TO CONT THRU SAT NGT...BEFORE BACKING NELY
SUN IN RESPONSE TO LOPRES MVG NWD IN THE WRN ALTC. ALTHO P-GRAD WL
BE TIGHTENING...SUSTAINED SPDS SHUD REMAIN AOB 10 KT...THO MAY HV A
FEW HIER GUSTS IN THE MID BAY SUN.
THE LOW WL EXIT SUN NGT-MON...AND HIPRES WL RTN. BY TUE OF NEXT
WK...WNDS WL BECOME SLY AS THE RDG AXIS MVS OFFSHORE. SPDS WL STILL
BE STRUGGLING TO EXCEED 10 KT.
&&
.TIDES/COASTAL FLOODING...
ONSHORE FLOW AROUND THE HIGH WILL PERSIST THROUGH THE WEEKEND.
HOWEVER...WINDS WILL BE LIGHT SO MOST AREAS ARE NOT EXPECTED TO
EXPERIENCE WIDESPREAD COASTAL FLOODING. WILL HAVE TO MONITOR TIDAL
ANOMALIES FOR SENSITIVE AREAS SUCH AS ANNAPOLIS THOUGH WITH HIGH
FRI NGT AND AGAIN ON SAT NGT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...WOODY!
PRVS...HAS/HTS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
331 PM CDT FRI SEP 27 2013
.SYNOPSIS...
ISSUED AT 330 PM CDT FRI SEP 27 2013
A HIGHLY AMPLIFIED UPPER AIR PATTERN IS IN PLACE THIS
AFTERNOON...WITH A RIDGE EXTENDING FROM THE GULF OF MEXICO UP INTO
THE GREAT LAKES AND A DEEP TROUGH EXTENDING DOWN THE ERN EDGE OF THE
ROCKIES.
AT THE SFC...CYCLOGENESIS HAS BEEN TAKING PLACE ACROSS SE COLORADO
TODAY...WHERE BETWEEN 12Z AND 19Z WE HAVE SEEN A 1001 MB LOW DEEPEN
INTO A 997 MB LOW. AT 3 PM...A MORE OR LESS STATIONARY FRONT
EXTENDED FROM THE COLORADO LOW NORTHEAST ACROSS ERN SODAK AND OFF TO
NEAR LAKE OF THE WOODS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 330 PM CDT FRI SEP 27 2013
SATELLITE IMAGERY THIS AFTERNOON IS SHOWING LIFT AHEAD OF THE
ROCKIES WAVE BEGINNING TO INCREASE AS CLOUD TOPS BEGIN TO COOL FROM
NW KS UP INTO SE SODAK. THIS IS THE BEGINNINGS OF THE POST FRONTAL
BAND OF FGEN INDUCED PRECIP THAT ALL MODELS SHOW DEVELOPING THIS
EVENING...WEST OF THE MPX AREA. BESIDE THE COOLING CLOUD
TOPS...SATELLITE ALSO SHOWING CLEARING RAPIDLY MOVING NORTH ACROSS
MN AND WE HAVE REALLY SEEN WINDS/TEMPS RESPOND TO THE
CLEARING...WITH FAIRMONT HITTING 88 AT 3 PM...ALONG WITH GUSTS
ACROSS SOUTH CENTRAL MN ALSO APPROACHING 40 MPH.
BIGGEST CHANGE MADE TO THE FORECAST WAS TO SLOW DOWN THE ARRIVAL OF
PRECIP TONIGHT. THE REASON IS THAT THE FRONT AND ITS ASSOCIATED FGEN
BAND DO NOT LOOK TO MOVE EAST UNTIL THE UPPER WAVE BEGINS TO EJECT
ACROSS THE PLAINS...WHICH DOES NOT BEGIN TO HAPPEN UNTIL AFTER 6Z.
GIVEN STRONG FORCING ASSOCIATED WITH THIS WAVE...SEEING STRONG
AGREEMENT AMONG HIRES MODELS...WITH EVERYTHING FROM THE HOPWRF
MEMBERS TO YOUR SPC/NMM/ARW WRFS SHOWING RAIN NOT BEGINNING TO MOVE
INTO WRN MN UNTIL ALMOST 9Z. THOUGHT ORIENTATION OF INHERITED POPS
FOR TONIGHT THROUGH SATURDAY LOOKED GOOD...SO MAINTAINED THE LOOK OF
THE POP GRIDS...JUST SLOWED THINGS DOWN BY 3 OR 4 HOURS TODAY.
HAVE MAINTAINED SOME CHANCE POPS IN THE NW CWA BETWEEN 00Z AND 06Z
AS THE HRRR CONTINUES TO SHOW SCATTERED CONVECTION DEVELOPING ALONG
THE COLD FRONT BETWEEN 00Z AND 02Z...BUT THE MAIN SHOW PRECIPITATION
WISE IS COMING LATE TONIGHT. IF WE DO GET CONVECTION TO FIRE AS THE
HRRR SUGGESTS...DO NOT ANTICIPATE ANY OF IT WILL BE SEVERE THANKS TO
SBCAPES LESS THAN 1000 J/KG. WOULD NEED MORE ROBUST INSTABILITY TO
GET MUCH MORE OF A SEVERE THREAT.
FOR TONIGHT...WAS TEMPTED TO REMOVE ANY THUNDER MENTION FROM THE
FORECAST SINCE FOR THE MOST PART THIS WILL JUST BE RAIN. BUT WILL
LIKELY HAVE A FEW RUMBLES OF THUNDER AS THE BAND MOVES THROUGH...SO
MAINTAINED THE ISO THUNDER WORDING.
FOR QPF...MODEL CONSENSUS HAS REMAINED QUITE HIGH IN 0.3-0.5 INCHES
FALLING ACROSS MOST OF THE AREA...SO KEPT THE QPF FORECAST CLOSE TO
A WPC/MODEL BLEND.
FINALLY FOR TEMPERATURES...BEING OUT AHEAD OF THE FRONT WE WILL HAVE
ANOTHER MILD NIGHT...WITH MUCH OF THE AREA ONLY FALLING BACK INTO
THE MID 60S FOR LOWS...WHICH IS RIGHT ABOUT NORMAL...FOR HIGHS THIS
TIME OF YEAR! FOR SATURDAY...USED THE NAM TO RUN THE DIURNAL TREND
FOR TEMPERATURES...WHICH RESULTED IN FALLING TEMPERATURES DURING THE
MORNING AND AFTERNOON IN THE ERN CWA AS THE BAND OF RAIN MOVES FROM
ERN MN INTO WRN WI.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 PM CDT FRI SEP 27 2013
AFTER SATURDAY SYSTEM MOVES ACROSS THE UPPER MIDWEST...THE MEAN
FLOW AND ASSOCIATED MOISTURE AND SFC FEATURES WILL BE WELL INTO
CANADA LEADING TO A DRY PERIOD THRU THE MIDDLE OF NEXT WEEK.
OVER THE PAST WEEK OR TWO...THE PACIFIC NW HAS BEEN VERY WET DUE
TO A PERSISTENT ONSHORE FLOW WHICH IS EXPECTED THRU THE EARLY PART
OF NEXT WEEK. OUR REGION WILL HOLD ONTO A MORE FAST WEST TO EAST
FLOW...WITH THE CENTRAL U.S. AND THE SE MUCH WARMER AS AN UPPER
LEVEL RIDGE BEGINS TO BUILD. THE MEAN LONG WAVE TROUGH ACROSS
WESTERN PART OF NORTH AMERICA IS EXPECTED TO TRANSITION TO A WEAK
UPPER RIDGE /PACIFIC NW/...WHICH IS A DRY WEATHER PATTERN.
BETWEEN THE RIDGE IN THE SE...AND THE PACIFIC NW...THE LONG WAVE
TROUGH IS EXPECTED TO MOVE ACROSS THE ROCKIES AND INTO THE NORTHERN
PLAINS BY LATE NEXT WEEK. BASICALLY THIS IS A WETTER PATTERN FOR
THE UPPER MIDWEST AS MOISTURE FROM THE GULF BEGINS TO INTERACT
WITH A POWERFUL JET STREAM PROGGED TO BE ACROSS THE NORTHERN U.S.
THE UPPER JET ALONE WILL LEAD TO A BETTER CHC OF CYCLOGENESIS
DEVELOPING IN THE PLAINS /INCREASING MOIST FROM THE GULF/ AND AN
INCREASE IN PRECIPITATION CHC/S. THE MAIN UNCERTAINTY IS TIMING OF
THIS PATTERN CHG...ESPECIALLY IN REGARDS TO SFC FEATURES. BOTH THE
GFS/EC HAVE A SIMILAR PATTERN LATE NEXT WEEK...BUT THE DIFFERENCES
ARISE IN THE AMPLIFICATION. THE GFS IS MORE AMPLIFIED...ESPECIALLY
BY FRIDAY WITH A CUT OFF SYSTEM ACROSS THE WESTERN GREAT LAKES.
THE EC IS MORE PROGRESSIVE...BUT HAS THE SAME LONG WAVE TROUGH IN
THE NORTHERN U.S. THE GFS ENSEMBLE MEAN OF THE 50H PATTERN SEEMS
TO BE MORE IN LINE OF A DEEPER TROUGH...AND BETTER UPPER LEVEL
FORCING FOR THE UPPER MIDWEST. WILL HOLD ONTO THE CHC/LIKELY POPS
FOR THU/FRI OF NEXT WEEK. HOWEVER...TRENDS OF THE MODELS WILL
DICTATE THE STRENGTH AND SPEED ONCE THE PATTERN BEGINS TO CHG
EARLY NEXT WEEK.
A FINAL NOTE...BOTH THE GFS/EC DOES SHOW A SIGNIFICANT COOL DOWN
ONCE THIS PATTERN DEVELOPS AND MOVES THRU THE WEEKEND OF OCTOBER
5TH. 85H TEMPS FRIDAY NIGHT ARE COLD ENOUGH FOR SNOW IN THE
ARROWHEAD OF MN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1244 PM CDT FRI SEP 27 2013
AREA OF SHRA WILL LIFT THROUGH CENTRAL MN THIS AFTERNOON...BRIEFLY
IMPACTING AXN/STC. MAIN SHIELD OF PRECIP WILL COME IN BEHIND THE
COLD FRONT TONIGHT...BUT BEFORE THAT COMES IN...THE HRRR DOES SHOW
THE POTENTIAL FOR SOME PREFRONTAL SHRA/TSRA IN THE AXN/RWF AREA
BETWEEN 2 AND 5Z. OTHERWISE...FOLLOWED LEAD OF GUIDANCE IN SLOWING
THE ARRIVAL OF THE RAINFALL AND ASSOCIATED MVFR CIGS TONIGHT BY A
FEW HOURS. HAVE ALSO TEMPERED WINDS SLIGHTLY TODAY AS CLOUD COVER
HAS LIMITED MIXING. ALSO SLOWED VEERING OF WINDS TONIGHT/SAT
MORNING TO THE WEST DUE TO THE SLOWER FRONTAL PROJECTION. FOR
CIGS...HAVE KEPT CIGS NO WORSE THAN MVFR...BUT COULD SEE A BRIEF
PERIOD OF IFR CIGS WITH THE RAIN MOVING THROUGH.
KMSP...WILL CONTINUE TO SEE A COUPLE OF SPRINKLES THROUGH
19Z...BUT MAIN PRECIP WILL BE COMING SAT MORNING. STRONG AGREEMENT
AMONGST HI-RES REFLECTIVITY FORECASTS WITH RAIN MOVING IN TO THE
FIELD AFTER 12Z. THEY ARE LIKELY A LITTLE SLOW...BUT BY ONLY A
COUPLE OF HOURS. FOR NOW HAVE KEPT CIGS ABOVE 017...BUT THERE WILL
LIKELY BE A FEW HOURS DURING THE MORNING WHERE CIGS BETWEEN 010
AND 015 WILL BE POSSIBLE.
/OUTLOOK FOR KMSP/
.SUN...VFR. WINDS SW 5-10 KTS.
.MON...VFR. WINDS S 10-15 KTS.
.TUE...VFR. WINDS W 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SYNOPSIS...MPG
SHORT TERM...MPG
LONG TERM...JLT
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
108 PM CDT FRI SEP 27 2013
.UPDATE...
ISSUED AT 942 AM CDT FRI SEP 27 2013
DID DECREASE POPS FOR THIS MORNING ACROSS THE TWIN CITIES UP INTO
CENTRAL MN AS THE INITIAL PUSH OF SHOWERS QUICKLY DISSIPATES AS
MAIN LLJ PUSH IS HEADING INTO NRN MN. DID HOWEVER INCREASE POPS FOR
A BIT THIS MORNING INTO SW MN AS SHOWERS CONTINUE TO DEVELOP OVER
NW IA IN A BAND IF ENHANCED MOISTURE TRANSPORT AND ISENTROPIC
LIFT. THE RAP SHOWS THIS BIT OF FORCING DIMINISHING THIS MORNING
AS IT MOVES NORTH AND GETS ABSORBED INTO THE MAIN LLJ THAT WILL BE
FROM THE TWIN CITIES ON NORTH BY 18Z.
ALSO TWEAKED TIMING OF THE RETURN OF POPS THIS AFTERNOON/EVENING...
MAINLY SLOWING THE ERN PUSH OF THINGS SOME AS THE 12Z NAM...ALONG
WITH 00Z HIRES NMM/ARW DO NOT SHOW MAIN DEFORMATION BAND OF PRECIP
MOVING INTO WRN MN UNTIL AFTER 6Z. IN FACT...THE 12Z NAM DOES NOT
SHOW THAT PRECIP MOVING IN UNTIL AFTER 9Z TONIGHT...SO MAY NEED TO
SLOW THINGS DOWN A BIT MORE DURING THE DAY.
AS FOR ANY SEVERE THREAT...THE 12Z NAM ALONG WITH THE LAST COUPLE
OF RUNS OF THE HRRR DO SHOW SOME ISO/SCT ACTIVITY DEVELOPING ALONG
THE COLD FRONT OUT IN WRN MN BETWEEN 00Z AND 03Z. UPDRAFT HELICITY
WITH THIS ACTIVITY ON THE HRRR IS NON-EXISTENT...BUT THE HRRR DOES
SHOW THE POTENTIAL FOR SOME GUSTIER WINDS WITH THE ACTIVITY IT
DEVELOPS. STILL THINK THE SEVERE THREAT IS PRETTY LOW...BUT WILL
HAVE TO BE WATCHED.
NO CHANGES WERE MADE TO TEMPS...YET. EXTENSIVE MID LEVEL CLOUD
COVER DOES HAVE ME WORRIED CURRENT HIGHS MAY BE RUNNING A LITTLE
WARM...BUT WARM NOSE WITH A TEMP OF 22C WAS SITUATED DOWN AT 900
MB ON THE 12Z MPX SOUNDING THIS MORNING. MIXING THIS DOWN TO THE
SFC WOULD RESULT IN HIGHS IN THE MID 80S. WILL NOT TAKE MUCH
MIXING...ESPECIALLY WITH THE WINDS PRESENT TO GET THE BOUNDARY
LAYER UP TO THIS DEPTH...SO LEFT HIGHS FOR TODAY ALONE...JUST
SLOWED DOWN HOW QUICKLY WE GET THERE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT FRI SEP 27 2013
TIMING OF CONVECTION FOR PRIMARILY THIS MORNING...AND THEN TONIGHT AS
THE FRONT SWINGS EAST...TO EASTERN MN LATE.
LINE OF CONVECTION DEVELOPED ALONG THE LOW LEVEL JET...MAXIMUM SURGE
OF H85 MOISTURE TRANSPORT THIS MORNING. WATER VAPOR IMAGERY IS
SHOWING WEAK SHORT WAVE ASSOCIATED WITH THIS MOVING THROUGH EASTERN
NEBRASKA/SOUTHEAST SOUTH DAKOTA THIS MORNING. LATEST HRRR SHOWS
POSSIBLY A COUPLE OF BANDS OF ACTIVITY LIFTING NORTHEAST IS NARROW
MOISTURE PLUME. WILL HAVE TO MONITOR THIS...AS THERE COULD BE
ANOTHER WEAK WAVE LIFTING NORTHEAST EXITING COLORADO REGION
NOW...BEHIND THE INITIAL ONE. DID MOVE POPS EAST TO THE MN/WI
BORDER THIS MORNING AND THEN LIFTED THEM TO THE NORTH THIS
AFTERNOON. MAX TEMPERATURES TODAY WILL BE A FUNCTION OF CLOUD
COVER. VARIOUS MODELS SUGGEST SOME WARMER MID LEVEL AIR LIFTING
INTO THE AREA BEHIND THIS INITIAL MOISTURE SURGE. THIS MAY BE
ENOUGH TO CAP THINGS FOR THE AFTERNOON...AND THIN THE CLOUD COVER
SOME. DID A BLEND OF BIAS CORRECTED AND OFFICIAL FOR TEMPERATURES
TODAY. SOUTHERLY WINDS WILL INCREASE THIS MORNING ACROSS MOST OF
THE AREA AHEAD OF THE FRONT. AGAIN SOME 35 MPH WIND GUSTS
LIKELY...ESPECIALLY OVER THE SOUTH CENTRAL PORTION OF THE AREA.
THE FRONT MOVES INTO THE AREA TONIGHT WITH AMPLE FRONTOGENETIC
FORCING FOR WIDESPREAD RAIN...PERHAPS AN ISOLD THUNDER THREAT
OVERNIGHT AS INSTABILITY IS WEAK. SHOULD MAKE IT TO THE MN/WI BORDER
THROUGH 12Z SAT. DID SOME TIME ADJUSTMENT TO POPS...BUT GOING
FORECAST LOOKED PRETTY GOOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 357 AM CDT FRI SEP 27 2013
MODELS ARE IN FINE AGREEMENT REGARDING THE PASSAGE OF THE COLD
FRONT ACROSS THE AREA ON SATURDAY...WITH A DECENT ACCOMPANYING SHORTWAVE
TROUGH SUPPLYING A SURGE OF 700-600MB FRONTOGENESIS AND 850MB
MOISTURE TRANSPORT BETWEEN 09Z AND 18Z SATURDAY. THEREFORE...HAVE
CONTINUED HIGH CONFIDENCE IN A 3 HOUR WINDOW OF CATEGORICAL
/80-100 PERCENT/ POPS ON SATURDAY MORNING /MN/ INTO EARLY
AFTERNOON /WI/. PROGGED ELEVATED INSTABILITY /BEST LIFTED INDICES/
INDICATES THE POTENTIAL FOR ISOLATED THUNDER WITH THE SHOWER
ACTIVITY /MAINLY UP TO 18Z/. LOOKS LIKE A FAIRLY WIDESPREAD
QUARTER TO HALF INCH RAINFALL EVENT...WITH ISOLATED HIGHER
AMOUNTS. BREEZY WESTERLY WINDS WILL PREVAIL SATURDAY IN THE WAKE
OF THE FRONT...WITH NEARLY STEADY TO SLIGHTLY FALLING DAYTIME
TEMPS.
IN THE WAKE OF THE SATURDAY SYSTEM...SEMI ZONAL FLOW DEVELOPS
ACROSS THE NORTHERN CONUS. TEMPERATURES MODERATE WELL INTO THE
70S FOR SUNDAY THROUGH MUCH OF THE UPCOMING WEEK...WITH DRY
WEATHER EXPECTED THROUGH WEDNESDAY.
BOTH ECMWF AND GFS MODELS FEATURE THE AMPLIFICATION OF A TROUGH
OVER THE SOUTHWESTERN CONUS DURING THE LAST HALF OF NEXT
WEEK...WITH THE ASSOCIATED SURFACE TROUGH/FRONTS LIFTING INTO THE
AREA IN THE THURSDAY-FRIDAY TIME FRAME. HAVE INCLUDED LIKELY POPS
ON THURSDAY EVE/NIGHT...ALTHOUGH THAT TIMING COULD SHIFT A BIT WITH
FUTURE MODEL RUNS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1244 PM CDT FRI SEP 27 2013
AREA OF SHRA WILL LIFT THROUGH CENTRAL MN THIS AFTERNOON...BRIEFLY
IMPACTING AXN/STC. MAIN SHIELD OF PRECIP WILL COME IN BEHIND THE
COLD FRONT TONIGHT...BUT BEFORE THAT COMES IN...THE HRRR DOES SHOW
THE POTENTIAL FOR SOME PREFRONTAL SHRA/TSRA IN THE AXN/RWF AREA
BETWEEN 2 AND 5Z. OTHERWISE...FOLLOWED LEAD OF GUIDANCE IN SLOWING
THE ARRIVAL OF THE RAINFALL AND ASSOCIATED MVFR CIGS TONIGHT BY A
FEW HOURS. HAVE ALSO TEMPERED WINDS SLIGHTLY TODAY AS CLOUD COVER
HAS LIMITED MIXING. ALSO SLOWED VEERING OF WINDS TONIGHT/SAT
MORNING TO THE WEST DUE TO THE SLOWER FRONTAL PROJECTION. FOR
CIGS...HAVE KEPT CIGS NO WORSE THAN MVFR...BUT COULD SEE A BRIEF
PERIOD OF IFR CIGS WITH THE RAIN MOVING THROUGH.
KMSP...WILL CONTINUE TO SEE A COUPLE OF SPRINKLES THROUGH
19Z...BUT MAIN PRECIP WILL BE COMING SAT MORNING. STRONG AGREEMENT
AMONGST HI-RES REFLECTIVITY FORECASTS WITH RAIN MOVING IN TO THE
FIELD AFTER 12Z. THEY ARE LIKELY A LITTLE SLOW...BUT BY ONLY A
COUPLE OF HOURS. FOR NOW HAVE KEPT CIGS ABOVE 017...BUT THERE WILL
LIKELY BE A FEW HOURS DURING THE MORNING WHERE CIGS BETWEEN 010
AND 015 WILL BE POSSIBLE.
/OUTLOOK FOR KMSP/
.SUN...VFR. WINDS SW 5-10 KTS.
.MON...VFR. WINDS S 10-15 KTS.
.TUE...VFR. WINDS W 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...MPG
SHORT TERM...DWE
LONG TERM...LS
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
943 AM CDT FRI SEP 27 2013
.UPDATE...
ISSUED AT 942 AM CDT FRI SEP 27 2013
DID DECREASE POPS FOR THIS MORNING ACROSS THE TWIN CITIES UP INTO
CENTRAL MN AS THE INITIAL PUSH OF SHOWERS QUICKLY DISSIPATES AS
MAIN LLJ PUSH IS HEADING INTO NRN MN. DID HOWEVER INCREASE POPS FOR
A BIT THIS MORNING INTO SW MN AS SHOWERS CONTINUE TO DEVELOP OVER
NW IA IN A BAND IF ENHANCED MOISTURE TRANSPORT AND ISENTROPIC
LIFT. THE RAP SHOWS THIS BIT OF FORCING DIMINISHING THIS MORNING
AS IT MOVES NORTH AND GETS ABSORBED INTO THE MAIN LLJ THAT WILL BE
FROM THE TWIN CITIES ON NORTH BY 18Z.
ALSO TWEAKED TIMING OF THE RETURN OF POPS THIS AFTERNOON/EVENING...
MAINLY SLOWING THE ERN PUSH OF THINGS SOME AS THE 12Z NAM...ALONG
WITH 00Z HIRES NMM/ARW DO NOT SHOW MAIN DEFORMATION BAND OF PRECIP
MOVING INTO WRN MN UNTIL AFTER 6Z. IN FACT...THE 12Z NAM DOES NOT
SHOW THAT PRECIP MOVING IN UNTIL AFTER 9Z TONIGHT...SO MAY NEED TO
SLOW THINGS DOWN A BIT MORE DURING THE DAY.
AS FOR ANY SEVERE THREAT...THE 12Z NAM ALONG WITH THE LAST COUPLE
OF RUNS OF THE HRRR DO SHOW SOME ISO/SCT ACTIVITY DEVELOPING ALONG
THE COLD FRONT OUT IN WRN MN BETWEEN 00Z AND 03Z. UPDRAFT HELICITY
WITH THIS ACTIVITY ON THE HRRR IS NON-EXISTENT...BUT THE HRRR DOES
SHOW THE POTENTIAL FOR SOME GUSTIER WINDS WITH THE ACTIVITY IT
DEVELOPS. STILL THINK THE SEVERE THREAT IS PRETTY LOW...BUT WILL
HAVE TO BE WATCHED.
NO CHANGES WERE MADE TO TEMPS...YET. EXTENSIVE MID LEVEL CLOUD
COVER DOES HAVE ME WORRIED CURRENT HIGHS MAY BE RUNNING A LITTLE
WARM...BUT WARM NOSE WITH A TEMP OF 22C WAS SITUATED DOWN AT 900
MB ON THE 12Z MPX SOUNDING THIS MORNING. MIXING THIS DOWN TO THE
SFC WOULD RESULT IN HIGHS IN THE MID 80S. WILL NOT TAKE MUCH
MIXING...ESPECIALLY WITH THE WINDS PRESENT TO GET THE BOUNDARY
LAYER UP TO THIS DEPTH...SO LEFT HIGHS FOR TODAY ALONE...JUST
SLOWED DOWN HOW QUICKLY WE GET THERE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT FRI SEP 27 2013
TIMING OF CONVECTION FOR PRIMARILY THIS MORNING...AND THEN TONIGHT AS
THE FRONT SWINGS EAST...TO EASTERN MN LATE.
LINE OF CONVECTION DEVELOPED ALONG THE LOW LEVEL JET...MAXIMUM SURGE
OF H85 MOISTURE TRANSPORT THIS MORNING. WATER VAPOR IMAGERY IS
SHOWING WEAK SHORT WAVE ASSOCIATED WITH THIS MOVING THROUGH EASTERN
NEBRASKA/SOUTHEAST SOUTH DAKOTA THIS MORNING. LATEST HRRR SHOWS
POSSIBLY A COUPLE OF BANDS OF ACTIVITY LIFTING NORTHEAST IS NARROW
MOISTURE PLUME. WILL HAVE TO MONITOR THIS...AS THERE COULD BE
ANOTHER WEAK WAVE LIFTING NORTHEAST EXITING COLORADO REGION
NOW...BEHIND THE INITIAL ONE. DID MOVE POPS EAST TO THE MN/WI
BORDER THIS MORNING AND THEN LIFTED THEM TO THE NORTH THIS
AFTERNOON. MAX TEMPERATURES TODAY WILL BE A FUNCTION OF CLOUD
COVER. VARIOUS MODELS SUGGEST SOME WARMER MID LEVEL AIR LIFTING
INTO THE AREA BEHIND THIS INITIAL MOISTURE SURGE. THIS MAY BE
ENOUGH TO CAP THINGS FOR THE AFTERNOON...AND THIN THE CLOUD COVER
SOME. DID A BLEND OF BIAS CORRECTED AND OFFICIAL FOR TEMPERATURES
TODAY. SOUTHERLY WINDS WILL INCREASE THIS MORNING ACROSS MOST OF
THE AREA AHEAD OF THE FRONT. AGAIN SOME 35 MPH WIND GUSTS
LIKELY...ESPECIALLY OVER THE SOUTH CENTRAL PORTION OF THE AREA.
THE FRONT MOVES INTO THE AREA TONIGHT WITH AMPLE FRONTOGENETIC
FORCING FOR WIDESPREAD RAIN...PERHAPS AN ISOLD THUNDER THREAT
OVERNIGHT AS INSTABILITY IS WEAK. SHOULD MAKE IT TO THE MN/WI BORDER
THROUGH 12Z SAT. DID SOME TIME ADJUSTMENT TO POPS...BUT GOING
FORECAST LOOKED PRETTY GOOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 357 AM CDT FRI SEP 27 2013
MODELS ARE IN FINE AGREEMENT REGARDING THE PASSAGE OF THE COLD
FRONT ACROSS THE AREA ON SATURDAY...WITH A DECENT ACCOMPANYING SHORTWAVE
TROUGH SUPPLYING A SURGE OF 700-600MB FRONTOGENESIS AND 850MB
MOISTURE TRANSPORT BETWEEN 09Z AND 18Z SATURDAY. THEREFORE...HAVE
CONTINUED HIGH CONFIDENCE IN A 3 HOUR WINDOW OF CATEGORICAL
/80-100 PERCENT/ POPS ON SATURDAY MORNING /MN/ INTO EARLY
AFTERNOON /WI/. PROGGED ELEVATED INSTABILITY /BEST LIFTED INDICES/
INDICATES THE POTENTIAL FOR ISOLATED THUNDER WITH THE SHOWER
ACTIVITY /MAINLY UP TO 18Z/. LOOKS LIKE A FAIRLY WIDESPREAD
QUARTER TO HALF INCH RAINFALL EVENT...WITH ISOLATED HIGHER
AMOUNTS. BREEZY WESTERLY WINDS WILL PREVAIL SATURDAY IN THE WAKE
OF THE FRONT...WITH NEARLY STEADY TO SLIGHTLY FALLING DAYTIME
TEMPS.
IN THE WAKE OF THE SATURDAY SYSTEM...SEMI ZONAL FLOW DEVELOPS
ACROSS THE NORTHERN CONUS. TEMPERATURES MODERATE WELL INTO THE
70S FOR SUNDAY THROUGH MUCH OF THE UPCOMING WEEK...WITH DRY
WEATHER EXPECTED THROUGH WEDNESDAY.
BOTH ECMWF AND GFS MODELS FEATURE THE AMPLIFICATION OF A TROUGH
OVER THE SOUTHWESTERN CONUS DURING THE LAST HALF OF NEXT
WEEK...WITH THE ASSOCIATED SURFACE TROUGH/FRONTS LIFTING INTO THE
AREA IN THE THURSDAY-FRIDAY TIME FRAME. HAVE INCLUDED LIKELY POPS
ON THURSDAY EVE/NIGHT...ALTHOUGH THAT TIMING COULD SHIFT A BIT WITH
FUTURE MODEL RUNS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 532 AM CDT FRI SEP 27 2013
WILL CONTINUE THE WIND SHEAR POTENTIAL EARLY OVER WESTERN
WISCONSIN WHERE SHEAR POTENTIAL IS STRONGEST...WITH LIGHTER
SOUTHEAST SURFACE WINDS. LINE OF CONVECTION LIFTING NORTHEAST
AROUND 37KTS. SOME EMBEDDED THUNDER AND WILL INCLUDE TEMPO GROUP
FOR THIS AT KRWF/KAXN/KSTC THROUGH 15Z OR SO. DO ANTICIPATE IT
WILL HOLD TOGETHER AND WILL MENTION SHRA AT KMSP. NICE SHORT WAVE
ASSOCIATED WITH THIS AS IT LIFTS TO THE NORTHEAST. ACCAS REMAINS
TO THE SOUTHWEST IN MOIST PLUME PROGGED TO CONTINUE TO LIFT
THROUGH THE AREA...AT LEAST THIS MORNING. THEN ANTICIPATE A BREAK
BEFORE THE COLD FRONT MOVES INTO THE WEST THIS EVENING. WILL
GRADUALLY SHIFT IT EAST TO KMSP AREA THROUGH 12Z SATURDAY. EXPECT
CEILINGS TO DROP GRADAULLY TO IFR BEHIND FRONT...AND WILL MOVE
THIS THROUGH THE FAR WEST AFTER 06Z.28. SOUTHEAST TO SOUTH WINDS
INCREASING TO 15-20KTS WITH GUSTS IN EXCESS OF 30KTS PSBL INTO THE
AFTERNOON. THIS SHOULD DIMINISH THIS EVENING...BUT MAY REMAIN
GUSTY OVERNIGHT IN THE EAST IN TIGHTER PRESSURE GRADIENT. WINDS
WILL SWITCH TO THE NORTHWEST WITH FROPA.
KMSP...
VFR CONDS EXPECTED THROUGH MOST OF THE TAF. SOME CHANCE OF AT
LEAST SHRA MOVING INTO THE AREA IN THE 14Z-17Z PERIOD...AS THE
SHORT WAVE OVER THE SOUTHWEST LIFTS NORTHEAST. ABUNDANT ACCAS
BEHIND THIS WAVE...SO WILL LIKELY LINGER THE SHRA THREAT SOME.
SUSTAINED SE WINDS WILL PICK UP THIS MORNING 15-20 KT RANGE WITH
GUSTS APPROACHING 30 KT. MAIN FRONT DOESNT MOVE IN UNTIL AFTER 12Z
SAT. EXPECT CIGS TO DROP OFF TO AT LEAST MVFR IN -SHRA THROUGH
NOON SAT.
/OUTLOOK FOR KMSP/
SAT...MVFR CIGS EARLY WITH -SHRA...POTENTIALLY IFR VSBY IN HEAVIER
SHOWERS. VFR BY LATE AFTN. WINDS W 12-15 KTS.
SUN...VFR. WINDS SW 5-10 KTS.
MON...VFR. WINDS S 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...MPG
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
550 AM CDT FRI SEP 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT FRI SEP 27 2013
TIMING OF CONVECTION FOR PRIMARILY THIS MORNING...AND THEN TONIGHT AS
THE FRONT SWINGS EAST...TO EASTERN MN LATE.
LINE OF CONVECTION DEVELOPED ALONG THE LOW LEVEL JET...MAXIMUM SURGE
OF H85 MOISTURE TRANSPORT THIS MORNING. WATER VAPOR IMAGERY IS
SHOWING WEAK SHORT WAVE ASSOCIATED WITH THIS MOVING THROUGH EASTERN
NEBRASKA/SOUTHEAST SOUTH DAKOTA THIS MORNING. LATEST HRRR SHOWS
POSSIBLY A COUPLE OF BANDS OF ACTIVITY LIFTING NORTHEAST IS NARROW
MOISTURE PLUME. WILL HAVE TO MONITOR THIS...AS THERE COULD BE
ANOTHER WEAK WAVE LIFTING NORTHEAST EXITING COLORADO REGION
NOW...BEHIND THE INITIAL ONE. DID MOVE POPS EAST TO THE MN/WI
BORDER THIS MORNING AND THEN LIFTED THEM TO THE NORTH THIS
AFTERNOON. MAX TEMPERATURES TODAY WILL BE A FUNCTION OF CLOUD
COVER. VARIOUS MODELS SUGGEST SOME WARMER MID LEVEL AIR LIFTING
INTO THE AREA BEHIND THIS INITIAL MOISTURE SURGE. THIS MAY BE
ENOUGH TO CAP THINGS FOR THE AFTERNOON...AND THIN THE CLOUD COVER
SOME. DID A BLEND OF BIAS CORRECTED AND OFFICIAL FOR TEMPERATURES
TODAY. SOUTHERLY WINDS WILL INCREASE THIS MORNING ACROSS MOST OF
THE AREA AHEAD OF THE FRONT. AGAIN SOME 35 MPH WIND GUSTS
LIKELY...ESPECIALLY OVER THE SOUTH CENTRAL PORTION OF THE AREA.
THE FRONT MOVES INTO THE AREA TONIGHT WITH AMPLE FRONTOGENETIC
FORCING FOR WIDESPREAD RAIN...PERHAPS AN ISOLD THUNDER THREAT
OVERNIGHT AS INSTABILITY IS WEAK. SHOULD MAKE IT TO THE MN/WI BORDER
THROUGH 12Z SAT. DID SOME TIME ADJUSTMENT TO POPS...BUT GOING
FORECAST LOOKED PRETTY GOOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 357 AM CDT FRI SEP 27 2013
MODELS ARE IN FINE AGREEMENT REGARDING THE PASSAGE OF THE COLD
FRONT ACROSS THE AREA ON SATURDAY...WITH A DECENT ACCOMPANYING SHORTWAVE
TROUGH SUPPLYING A SURGE OF 700-600MB FRONTOGENESIS AND 850MB
MOISTURE TRANSPORT BETWEEN 09Z AND 18Z SATURDAY. THEREFORE...HAVE
CONTINUED HIGH CONFIDENCE IN A 3 HOUR WINDOW OF CATEGORICAL
/80-100 PERCENT/ POPS ON SATURDAY MORNING /MN/ INTO EARLY
AFTERNOON /WI/. PROGGED ELEVATED INSTABILITY /BEST LIFTED INDICES/
INDICATES THE POTENTIAL FOR ISOLATED THUNDER WITH THE SHOWER
ACTIVITY /MAINLY UP TO 18Z/. LOOKS LIKE A FAIRLY WIDESPREAD
QUARTER TO HALF INCH RAINFALL EVENT...WITH ISOLATED HIGHER
AMOUNTS. BREEZY WESTERLY WINDS WILL PREVAIL SATURDAY IN THE WAKE
OF THE FRONT...WITH NEARLY STEADY TO SLIGHTLY FALLING DAYTIME
TEMPS.
IN THE WAKE OF THE SATURDAY SYSTEM...SEMI ZONAL FLOW DEVELOPS
ACROSS THE NORTHERN CONUS. TEMPERATURES MODERATE WELL INTO THE
70S FOR SUNDAY THROUGH MUCH OF THE UPCOMING WEEK...WITH DRY
WEATHER EXPECTED THROUGH WEDNESDAY.
BOTH ECMWF AND GFS MODELS FEATURE THE AMPLIFICATION OF A TROUGH
OVER THE SOUTHWESTERN CONUS DURING THE LAST HALF OF NEXT
WEEK...WITH THE ASSOCIATED SURFACE TROUGH/FRONTS LIFTING INTO THE
AREA IN THE THURSDAY-FRIDAY TIME FRAME. HAVE INCLUDED LIKELY POPS
ON THURSDAY EVE/NIGHT...ALTHOUGH THAT TIMING COULD SHIFT A BIT WITH
FUTURE MODEL RUNS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 532 AM CDT FRI SEP 27 2013
WILL CONTINUE THE WIND SHEAR POTENTIAL EARLY OVER WESTERN
WISCONSIN WHERE SHEAR POTENTIAL IS STRONGEST...WITH LIGHTER
SOUTHEAST SURFACE WINDS. LINE OF CONVECTION LIFTING NORTHEAST
AROUND 37KTS. SOME EMBEDDED THUNDER AND WILL INCLUDE TEMPO GROUP
FOR THIS AT KRWF/KAXN/KSTC THROUGH 15Z OR SO. DO ANTICIPATE IT
WILL HOLD TOGETHER AND WILL MENTION SHRA AT KMSP. NICE SHORT WAVE
ASSOCIATED WITH THIS AS IT LIFTS TO THE NORTHEAST. ACCAS REMAINS
TO THE SOUTHWEST IN MOIST PLUME PROGGED TO CONTINUE TO LIFT
THROUGH THE AREA...AT LEAST THIS MORNING. THEN ANTICIPATE A BREAK
BEFORE THE COLD FRONT MOVES INTO THE WEST THIS EVENING. WILL
GRADUALLY SHIFT IT EAST TO KMSP AREA THROUGH 12Z SATURDAY. EXPECT
CEILINGS TO DROP GRADAULLY TO IFR BEHIND FRONT...AND WILL MOVE
THIS THROUGH THE FAR WEST AFTER 06Z.28. SOUTHEAST TO SOUTH WINDS
INCREASING TO 15-20KTS WITH GUSTS IN EXCESS OF 30KTS PSBL INTO THE
AFTERNOON. THIS SHOULD DIMINISH THIS EVENING...BUT MAY REMAIN
GUSTY OVERNIGHT IN THE EAST IN TIGHTER PRESSURE GRADIENT. WINDS
WILL SWITCH TO THE NORTHWEST WITH FROPA.
KMSP...
VFR CONDS EXPECTED THROUGH MOST OF THE TAF. SOME CHANCE OF AT
LEAST SHRA MOVING INTO THE AREA IN THE 14Z-17Z PERIOD...AS THE
SHORT WAVE OVER THE SOUTHWEST LIFTS NORTHEAST. ABUNDANT ACCAS
BEHIND THIS WAVE...SO WILL LIKELY LINGER THE SHRA THREAT SOME.
SUSTAINED SE WINDS WILL PICK UP THIS MORNING 15-20 KT RANGE WITH
GUSTS APPROACHING 30 KT. MAIN FRONT DOESNT MOVE IN UNTIL AFTER 12Z
SAT. EXPECT CIGS TO DROP OFF TO AT LEAST MVFR IN -SHRA THROUGH
NOON SAT.
/OUTLOOK FOR KMSP/
SAT...MVFR CIGS EARLY WITH -SHRA...POTENTIALLY IFR VSBY IN HEAVIER
SHOWERS. VFR BY LATE AFTN. WINDS W 12-15 KTS.
SUN...VFR. WINDS SW 5-10 KTS.
MON...VFR. WINDS S 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
356 AM CDT FRI SEP 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM CDT FRI SEP 27 2013
TIMING OF CONVECTION FOR PRIMARILY THIS MORNING...AND THEN TONIGHT AS
THE FRONT SWINGS EAST...TO EASTERN MN LATE.
LINE OF CONVECTION DEVELOPED ALONG THE LOW LEVEL JET...MAXIMUM SURGE
OF H85 MOISTURE TRANSPORT THIS MORNING. WATER VAPOR IMAGERY IS
SHOWING WEAK SHORT WAVE ASSOCIATED WITH THIS MOVING THROUGH EASTERN
NEBRASKA/SOUTHEAST SOUTH DAKOTA THIS MORNING. LATEST HRRR SHOWS
POSSIBLY A COUPLE OF BANDS OF ACTIVITY LIFTING NORTHEAST IS NARROW
MOISTURE PLUME. WILL HAVE TO MONITOR THIS...AS THERE COULD BE
ANOTHER WEAK WAVE LIFTING NORTHEAST EXITING COLORADO REGION
NOW...BEHIND THE INITIAL ONE. DID MOVE POPS EAST TO THE MN/WI
BORDER THIS MORNING AND THEN LIFTED THEM TO THE NORTH THIS
AFTERNOON. MAX TEMPERATURES TODAY WILL BE A FUNCTION OF CLOUD
COVER. VARIOUS MODELS SUGGEST SOME WARMER MID LEVEL AIR LIFTING
INTO THE AREA BEHIND THIS INITIAL MOISTURE SURGE. THIS MAY BE
ENOUGH TO CAP THINGS FOR THE AFTERNOON...AND THIN THE CLOUD COVER
SOME. DID A BLEND OF BIAS CORRECTED AND OFFICIAL FOR TEMPERATURES
TODAY. SOUTHERLY WINDS WILL INCREASE THIS MORNING ACROSS MOST OF
THE AREA AHEAD OF THE FRONT. AGAIN SOME 35 MPH WIND GUSTS
LIKELY...ESPECIALLY OVER THE SOUTH CENTRAL PORTION OF THE AREA.
THE FRONT MOVES INTO THE AREA TONIGHT WITH AMPLE FRONTOGENETIC
FORCING FOR WIDESPREAD RAIN...PERHAPS AN ISOLD THUNDER THREAT
OVERNIGHT AS INSTABILITY IS WEAK. SHOULD MAKE IT TO THE MN/WI BORDER
THROUGH 12Z SAT. DID SOME TIME ADJUSTMENT TO POPS...BUT GOING
FORECAST LOOKED PRETTY GOOD.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 357 AM CDT FRI SEP 27 2013
MODELS ARE IN FINE AGREEMENT REGARDING THE PASSAGE OF THE COLD
FRONT ACROSS THE AREA ON SATURDAY...WITH A DECENT ACCOMPANYING SHORTWAVE
TROUGH SUPPLYING A SURGE OF 700-600MB FRONTOGENESIS AND 850MB
MOISTURE TRANSPORT BETWEEN 09Z AND 18Z SATURDAY. THEREFORE...HAVE
CONTINUED HIGH CONFIDENCE IN A 3 HOUR WINDOW OF CATEGORICAL
/80-100 PERCENT/ POPS ON SATURDAY MORNING /MN/ INTO EARLY
AFTERNOON /WI/. PROGGED ELEVATED INSTABILITY /BEST LIFTED INDICES/
INDICATES THE POTENTIAL FOR ISOLATED THUNDER WITH THE SHOWER
ACTIVITY /MAINLY UP TO 18Z/. LOOKS LIKE A FAIRLY WIDESPREAD
QUARTER TO HALF INCH RAINFALL EVENT...WITH ISOLATED HIGHER
AMOUNTS. BREEZY WESTERLY WINDS WILL PREVAIL SATURDAY IN THE WAKE
OF THE FRONT...WITH NEARLY STEADY TO SLIGHTLY FALLING DAYTIME
TEMPS.
IN THE WAKE OF THE SATURDAY SYSTEM...SEMI ZONAL FLOW DEVELOPS
ACROSS THE NORTHERN CONUS. TEMPERATURES MODERATE WELL INTO THE
70S FOR SUNDAY THROUGH MUCH OF THE UPCOMING WEEK...WITH DRY
WEATHER EXPECTED THROUGH WEDNESDAY.
BOTH ECMWF AND GFS MODELS FEATURE THE AMPLIFICATION OF A TROUGH
OVER THE SOUTHWESTERN CONUS DURING THE LAST HALF OF NEXT
WEEK...WITH THE ASSOCIATED SURFACE TROUGH/FRONTS LIFTING INTO THE
AREA IN THE THURSDAY-FRIDAY TIME FRAME. HAVE INCLUDED LIKELY POPS
ON THURSDAY EVE/NIGHT...ALTHOUGH THAT TIMING COULD SHIFT A BIT WITH
FUTURE MODEL RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1106 PM CDT THU SEP 26 2013
SE WINDS HAVE GENERALLY SETTLED DOWN TO AROUND 10 KT...EVEN
SLIGHTLY LOWER AT A FEW SITES...AND WILL REMAIN AROUND THERE
THROUGH THE REST OF THE OVERNIGHT HOURS. LLWS IS EXPECTED TO
QUICKLY DEVELOP DUE TO THE STRENGTHENING LLJ. NAM/RAP/RUC BUFKIT
SOUNDINGS CONTINUE TO INDICATE STRONG WINDS /AROUND 40 KT/
VEERING WITH HEIGHT TO 2 KFT SO HAVE MAINTAINED LLWS MENTION TO
ALL TAF SITES OVERNIGHT THROUGH DAYBREAK TMRW MRNG. CLOUDS WILL
INCRS OVER WRN MN OVERNIGHT BUT CHCS FOR PRECIP REACHING THE WFO
MPX TAF SITES ARE CONFINED TO MAINLY KAXN-KRWF. TIMING IS A BIT
DIFFICULT DUE TO A RELATIVELY DEEP DRY LAYER IN THE LOWER LEVELS
SO AM NOT LOOKING FOR PRECIP OVERNIGHT. KSTC-KMSP MAY SEE A MIDLVL
CEILING DEVELOP BUT NOTHING MORE. CLOUDS GRADUALLY LOWER AND INCRS
IN COVERAGE THRU THE DAY TMRW AS THE CDFNT MEANDERING OVER THE
DAKOTAS INTO NEBRASKA SHIFTS E. CHCS INCREASE FOR SHOWERS AND
ISOLD TSTMS TO ENTER WRN-CENTRAL MN TMRW AFTN AND TMRW EVE.
KMSP...VFR CONDS EXPECTED THROUGHOUT...ALTHOUGH CHCS FOR PRECIP
INCREASE BY DAYBREAK SAT MRNG. MAINLY A WIND FCST WITH WINDS
REMAINING SE TO S. SUSTAINED SE WINDS IN THE 6-10 KT RANGE
OVERNIGHT WILL PICK UP AGAIN AFTER DAYBREAK TOMORROW TO THE 15-20
KT RANGE WITH GUSTS APPROACHING 30 KT. HAVE MAINTAINED LLWS
MENTION WITH WINDS UP TO 2 KFT COMING IN MORE SSW AT SPEEDS IN THE
35-40KT RANGE...CREATING A SIGNIFICANT ENOUGH VECTOR DIFFERENCE FOR
LLWS MENTION. MULTIPLE CU LAYERS TMRW WILL GRADUALLY LOWER AND
THICKEN AS THE DAY PROGRESSES...EVENTUALLY DEVELOPING INTO A
MIDLVL CEILING. SHWRS WILL TRY TO MOVE IN FROM THE W LATE TMRW
NIGHT INTO SAT MRNG...BUT THE HEAVIER PRECIP WILL OCCUR AFTER
DAYBREAK SAT THRU SAT AFTN.
/OUTLOOK FOR KMSP/
SAT...MVFR CIGS EARLY WITH -SHRA...POTENTIALLY IFR VSBY IN HEAVIER
SHOWERS. VFR BY LATE AFTN. WINDS W 12-15 KTS.
SUN...VFR. WINDS SW 5-10 KTS.
MON...VFR. WINDS S 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...JPC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
836 PM MDT SAT SEP 28 2013
.UPDATE...
WIND GUSTS ARE TOUCHING ADVISORY CRITERIA IN THE FAVORED GAP
LOCATIONS...WITH A GUST TO 59 MPH AT LIVINGSTON AND 60 MPH AT NYE
REPORTED EARLIER THIS EVENING. PACIFIC SHORTWAVE APPROACHING THE
WA/OR COAST IS INDUCING AN AREA OF PRESSURE FALLS IN BC/WA...AND
THIS WILL TRANSLATE EASTWARD THROUGH THE NIGHT AND ENHANCE THE LEE
SIDE TROF IN MT OVERNIGHT INTO EARLY SUNDAY. NAM/RAP EACH SHOW
750MB STABLE LAYER WINDS TO 65-70 KTS AT LVM BY TOMORROW
MORNING...SO NO DOUBT WIND GUSTS WILL BE STEPPING UP. WILL MAKE NO
CHANGES TO THIS SOMEWHAT EARLY SEASON HIGH WIND WARNING FOR THE
GAP AREAS. WELCOME TO THE COOL SEASON LIVINGSTON AND NYE.
THINKING A LITTLE BIT ABOUT RED LODGE...BOTH THE NAM AND RAP SHOW
MOUNTAIN TOP WINDS TO 70 KTS IN A STABLE LAYER ABOVE RED LODGE BY
12-15Z SUNDAY MORNING. OTHER FACTOR TO CONSIDER IS THE BACKING-TO-
SW MID LEVEL FLOW WHICH WILL BECOME MORE FAVORABLY ORIENTED TO THE
TERRAIN WHEN CONSIDERING MTN WAVE POTENTIAL AT THAT LOCATION. DO
NOT SEE A MECHANISM TO BRING WINDS DOWN TO RED LODGE...SYNOPTIC
SCALE ASCENT SHOULD BE INCREASING BY THEN...BUT NONETHELESS HAVE
RAISED GUSTS SOME AT RED LODGE AND NEARBY BEARCREEK SUNDAY
MORNING. WILL NEED TO KEEP WATCH OF THIS...BUT FOR NOW THINKING 40
MPH AT RED LODGE AND HIGHER GUSTS ON THE MOUNTAIN.
WILL BE A MILDER NIGHT PER THE WINDS AND INCREASING CLOUD COVER.
HAVE TWEAKED EXPECTED LOWS AND SKY COVER JUST A BIT. LIVINGSTON
MAY NOT DROP BELOW 50F...AND 52F IS THEIR RECORD HIGH MIN FOR THE
29TH.
JKL
&&
.SHORT TERM...VALID FOR SUN AND MON...
WARMER AND WINDY WEATHER PATTERN WILL CONTINUE THROUGH MONDAY
ACROSS THE FORECAST AREA. MAIN CHANGE WITH THIS FORECAST PACKAGE
IS TO ISSUE A HIGH WIND WARNING FOR THE LIVINGSTON AREA AND THE
BEARTOOTH FOOTHILLS NEAR NYE FROM 9PM TONIGHT THROUGH 6PM MONDAY.
A SERIES OF TWO SHORTWAVES EMBEDDED IN AN IMPRESSIVE 125+ KT H3
JET WILL CROSS THE FORECAST AREA...ONE SUNDAY MORNING AND ONE
MONDAY MORNING. BOTH OF THESE WAVES WILL CAUSE STRONG LEE SIDE
PRESSURE FALLS ALONG THE ROCKIES FROM MONTANA TO CANADA.
ACCOMPANYING THESE STRONG SURFACE PRESSURE FALLS WILL BE AN
IMPRESSIVE BELT OF 60+ KT H7 WINDS FOR SUNDAY MORNING AND 50+ KT
H7 WINDS FOR MONDAY MORNING. GIVEN THIS SET UP...CONFIDENCE IS
HIGH FOR A LIVINGSTON TO NYE GAP WIND EVENT FOR SUNDAY MORNING AND
MONDAY MORNING. WITH THE STRONGEST SURFACE PRESSURE GRADIENT AND
STRONGEST H7 WINDS ON SUNDAY MORNING...THIS PERIOD HAS THE HIGHEST
CONFIDENCE FOR HIGH WIND WARNING CRITERIA WINDS...WITH GUSTS TO
75+ MPH. MONDAY MORNING HAS A VERY SIMILAR SET UP WITH A SLIGHTLY
WEAKER PRESSURE GRADIENT AND SLIGHTLY LOWER H7 WINDS...THUS HIGH
END ADVISORY TYPE WINDS ARE EXPECTED...WITH GUSTS TO AROUND 70
MPH. DURING THE DAY ON SUNDAY...STRONG SUBSIDENCE AND MIXING OVER
LIVINGSTON WILL RESULT IN A STRONG MIXED WIND EVENT DURING THE
DAY. HOWEVER...THE MIXING POTENTIAL SUGGESTS LOW END ADVISORY TYPE
WINDS...WITH GUSTS TO ABOUT 60 MPH. THUS HAVE ISSUED A HIGH WIND
WARNING THROUGH THE WHOLE PERIOD TO COVER THE DUAL THREAT OF GAP
WIND EVENTS SUNDAY MORNING AND MONDAY MORNING...WITH LESSER BUT
STILL STRONG WINDS IN BETWEEN.
LOCATIONS FROM BIG TIMBER TO BILLINGS WILL SEE GUSTY WINDS ON
SUNDAY AND MONDAY WITH GUSTS 35 TO 50 MPH POSSIBLE. MONDAY WILL BE
THE BETTER OF THE TWO DAYS FOR THE STRONGEST WINDS...AS A SURFACE
COLD FRONT ASSOCIATED WITH THE SECOND SHORTWAVE TRACKS ACROSS THE
FORECAST AREA. A PERIOD OF STRONG COLD AIR ADVECTION AND
SUBSIDENCE BEHIND THE FRONT ON MONDAY SHOULD HELP GET SOME
STRONGER WINDS TO THE SURFACE BY THE AFTERNOON. THE STRONG MIXED
WIND SETUP WITH THE ENHANCED SUBSIDENCE BEHIND THE FRONT MATCH THE
PATTERN FOR A BIG TIMBER TO HARLOWTON WIND EVENT...WITH SUSTAINED
WINDS 35 TO 45 MPH AND GUSTS TO 60 MPH POSSIBLE THERE ON MONDAY.
FARTHER EAST TOWARD BILLINGS...WINDS WONT BE QUIET THAT STRONG
WITH GUSTS TO 50 MPH POSSIBLE BEHIND THE COLD FRONT.
TEMPERATURES ON SUNDAY WILL BE SLIGHTLY ABOVE SEASONAL NORMALS AS
STRONG DOWNSLOPE FLOW AND H7 TEMPERATURES OF 2 TO 4 C WILL COMBAT
THE INCREASING CLOUD COVER. WITH THE MODELS NOW HAVING SPED UP THE
TIMING OF THE COLD FRONT ON MONDAY...HAD TO CAUTIOUSLY DECREASE
HIGH TEMPERATURES. EXPECT TO SEE A GOOD SURGE OF COMPRESSIONAL
WARMING AHEAD OF THE FRONT AS IT CROSSES THE FORECAST AREA.
HOWEVER...THE FRONT WILL ALSO ECLIPSE THE DIURNAL HEATING CURVE
AND KEEP MANY LOCATIONS ACROSS CENTRAL AND WESTERN ZONES FROM
REALIZING THEIR FULL POTENTIAL.
CONDITIONS WILL BE DRY ON SUNDAY...WITH JUST SOME INCREASING
MOISTURE IN THE MOUNTAINS BRINGING A SLIGHT CHANCE OF SOME SHOWERS
IN THE SOUTHWEST MOUNTAINS. MOISTURE INCREASES MORE ON MONDAY WITH
THE SECOND SHORTWAVE...THUS A CHANCE OF SHOWERS IN THE MOUNTAINS
AGAIN ON MONDAY. SHOWERS WILL ALSO BE POSSIBLE ACROSS THE PLAINS
AS THE COLD FRONT CROSSES THE AREA. THE VERY STRONG DOWNSLOPING
WILL CERTAINLY BE A LIMITING FACTOR...AND THUS EXPECT AREAS FROM
BILLINGS AND WEST COULD MAINLY SEE SOME VIRGA. HOWEVER...
LOCATIONS FARTHER EAST SHOULD HAVE A BETTER CHANCE OF ACTUALLY
GETTING SOME SCATTERED PRECIPITATION TO THE GROUND.
CHURCH
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
THE LONG TERM BEGINS TUESDAY WITH SLIGHT RIDGING AHEAD OF AN
APPROACHING UPPER LEVEL TROUGH. TUES SHOULD BE A MILD...MOSTLY DRY
DAY. THE BIG QUESTION MARK IN THE EXTENDED IS HOW THE UPPER LEVEL
TROUGH PROJECTED TO MOVE THROUGH THE REGION WED INTO FRI ACTUALLY
ENDS UP EVOLVING. WHEREAS MODEL RUNS FROM YESTERDAY HAD A MORE
PROGRESSIVE...AND WEAKER TROUGH...THE CANADIAN AND GFS HAVE
TRENDED TOWARDS A SOMEWHAT SLOWER MOVING AND DEEPER
TROUGH...WHILE THE LATEST ECMWF RUN STILL MAINTAINS A MORE
PROGRESSIVE TROUGH. OPTED TO TREND TOWARDS THE CANADIAN AND GFS
BECAUSE THOSE SOLUTIONS LOOKS REASONABLE...GIVEN HOW THE TROUGH
THAT MOVED THROUGH THE REGION EARLIER THIS WEEK EVOLVED.
DID LOWER TEMPS A BIT ACROSS A GOOD DEAL OF THE REGION WED
THROUGH FRI...AND UPPED THE CHANCE OF PRECIP WED THROUGH THURS
NIGHT WITH GOOD MID/UPPER LEVEL FORCING PROGGED TO MOVE ACROSS THE
AREA. THURS LOOKS LIKE THE COOLEST...AND POTENTIALLY WETTEST DAY
DURING THE EXTENDED. 850 MB TEMPS BELOW 4C ACROSS A GOOD PORTION
OF THE REGION INDICATE AN INCREASING POTENTIAL FOR THE MOUNTAINS
AND HIGHER FOOTHILLS TO SEE SOME SNOW. WILL NEED TO WATCH FRI. IF
THE TROUGH ENDS UP SLOWING DOWN...TEMPS FRI COULD BE COOLER THAN
ADVERTISED AND WE MAY HAVE A BETTER CHANCE OF LINGERING PRECIP. A
MAJORITY OF THE MODELS FORECAST RIDGING TO BUILD BACK INTO THE
REGION BY SAT...SO AM PRETTY CONFIDENT THAT SAT WILL BE MILDER AND
DRY.
REGARDING TEMPS...HIGHS IN THE UPPER 50S TO MID 60S ARE EXPECTED
TUES. THE PUSH OF COOL AIR ASSOCIATED WITH THE UPPER LEVEL TROUGH
MOVES INTO THE REGION LATE WED INTO WED NIGHT...BUT CLOUD COVER
MAY HELP KEEP HIGHS A FEW DEGREES COOLER ON WED THAN TUES. THURS
HIGHS LOOK TO BE IN THE 40S AND 50S...WHILE HIGHS REBOUND A BIT
FRI...INTO THE 50S. SAT HIGHS ARE EXPECTED TO BE BACK INTO THE
60S. STC
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS THE REGION. WINDS WILL CONTINUE
TO BE THE PRIMARY AVIATION HAZARD. SOUTHWEST WINDS WILL REMAIN VERY
GUSTY ACROSS THE WEST...ESPECIALLY NEAR KLVM AND BIG TIMBER.
EXPECT GUSTS IN EXCESS OF 40 KTS TO CONTINUE THROUGH
TONIGHT...WITH GUSTS IN EXCESS OF 50 KTS BY SUNDAY MORNING IN AND
AROUND KLVM. FURTHER EAST...GUSTY WEST TO SOUTHWEST WINDS WILL DIE
DOWN TONIGHT...THOUGH WIND SHEAR IS POSSIBLE NEAR KSHR AND KMLS.
SOUTHWEST WINDS FROM KBIL EAST TOWARDS KMLS AND KBHK WILL
INCREASE AGAIN BY MID DAY SUNDAY...WITH GUSTS OVER 30 KTS
POSSIBLE. STC
&&
.PRELIMINARY POINT TEMP/POPS...
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 049/072 049/071 044/064 041/059 041/051 038/056 038/063
00/N 12/W 21/B 02/W 44/W 32/W 11/U
LVM 050/068 050/063 041/059 035/057 035/046 031/052 032/061
01/N 22/W 22/W 12/W 44/W 32/W 11/U
HDN 045/076 047/074 042/065 041/062 041/053 039/057 039/065
00/B 12/W 21/B 12/W 44/W 32/W 11/U
MLS 046/078 049/073 044/065 042/064 043/056 039/059 039/065
00/N 12/W 21/U 12/W 44/W 32/W 11/U
4BQ 042/076 046/075 043/065 041/065 043/055 039/056 040/064
00/U 11/N 21/U 12/W 44/W 32/W 11/U
BHK 040/076 044/073 040/064 038/063 042/055 037/056 037/063
00/U 01/N 21/N 12/W 44/W 32/W 11/U
SHR 039/072 045/072 041/062 037/062 040/051 036/053 036/062
00/U 01/N 21/U 02/W 44/W 42/W 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...HIGH WIND WARNING IN EFFECT UNTIL 6 PM MDT MONDAY FOR ZONES
65-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1129 PM CDT THU SEP 26 2013
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
BRISK SOUTH/SOUTHEAST WINDS WILL CONTINUE OVERNIGHT WITH FAIRLY
TIGHT PRESSURE GRADIENT. WINDS WILL INCREASE MORE BY MID MORNING.
ISOLATED TSRA WILL BE POSSIBLE OVERNIGHT AND INTO FRIDAY MORNING.
DID NOT MENTION AT THIS TIME...BUT DID INCLUDE SCT TO BKN CLOUDS
AT 10 THOUSAND FEET OR ABOVE.
BRIEF MVFR CEILINGS MAY DEVELOP ALONG AND BEHIND THE COLD FRONT
THAT WILL PUSH THROUGH FRIDAY NIGHT.
MILLER
&&
.PREV DISCUSSION... /ISSUED 937 PM CDT THU SEP 26 2013/
UPDATE...
DID A MINOR UPDATE TO EXPAND THE SLIGHT CHANCE OF THUNDERSTORMS
FOR OVERNIGHT AND INTO MID MORNING FRIDAY. THIS IS IN AGREEMENT
WITH LATEST SPC DAY 1 OUTLOOK.
STORMS COULD DEVELOP AS MID LEVEL MOISTURE INCREASES ON THE NOSE
OF A 50 KNOT LOW LEVEL JET. 00Z NAM12...LATEST RUNS OF HRRR AND
HIGH RESOLUTION RAP SHOW THIS.
MILLER
&&
PREV DISCUSSION... /ISSUED 331 PM CDT THU SEP 26 2013/
DISCUSSION...
20Z SURFACE ANALYSIS INDICATED A COLD FRONT EXTENDED FROM NEAR
KHON TO KLBF. THE FRONT WAS ASSOCIATED WITH A POTENT UPPER LEVEL
STORM SYSTEM CURRENTLY MOVING INTO SRN CANADA PER AFTN WATER
VAPOR IMAGERY. THE FRONT IS BECOMING PARALLEL TO THE MID LEVEL
FLOW AND WILL BECOME STATIONARY OVER THE NEXT 12-18 HRS GENERALLY
TO THE WEST OF OUR FA. AHEAD OF THE FRONT A 40-50 KT LOW LEVEL JET
IS EXPECTED TO INCREASE FM KS INTO NEB TONIGHT WITH THE TERMINUS
OVER NORTHEAST NEBRASKA AND ADJACENT AREAS OF SD/IA/MN. ISENTROPIC
ANALYSIS INDICATES DECENT LIFT ON THE 305 AND 310 K LAYERS...BUT
CONDENSATION PRESSURE DEFICITS REMAIN GENERALLY ABOVE 75 MB
INDICATING THE ATMOSPHERE IS FAIRLY DRY IN THIS REGION OF LIFT.
POINT FORECAST SOUNDINGS FROM THE NAM/RAP INDICATE STRONG MUCIN OF
75 TO 100 J/KG FOR ELEVATED PARCELS IN THIS AREA AS WELL. THUS
CONVECTIVE POTENTIAL TONIGHT APPEARS TO BE PRETTY LIMITED IF AT
ALL IN OUR CWA. THIS SEEMS REASONABLE GIVEN THE UPSTREAM MOISTURE
ON THE 12Z UPPER AIR ANALYSIS AND WARM H85 TEMPERATURES OVER THE
CNTRL PLAINS. THUS WE HAVE REMOVED POPS FOR TONIGHT EXCEPT FOR A
SMALL AREA IN KNOX/CEDAR COUNTIES CLOSE TO THE SD BORDER. THE
FRONT IS LIKELY TO RETROGRADE A BIT ON FRIDAY AHEAD OF A POTENT
UPPER LEVEL SYSTEM IN THE BASE OVER THE TROUGH THIS AFTN OVER THE
GREAT BASIN. THIS WILL LEAVE THE CWA WITH ANOTHER WINDY AND WARM
DAY. WE HAVE INCREASED GOING HIGHS A TOUCH GIVEN THE EXPECTED
STRONG MIXING AND WARM H85 TEMPERATURES.
THE GREAT BASIN SYSTEM WILL START TO EJECT TO THE EAST ON FRIDAY
NIGHT AND ALLOW FOR THE COLD FRONT TO ACCELERATE THROUGH NEB AS
THE SURFACE LOW DEEPENS AND LIFTS NEWD INTO THE DAKOTAS. MODELS
INDICATE STRONG Q-G FORCING ASSOCIATED WITH THIS SYSTEM WITH A
WELL-DEFINED DIV-Q MAXIMUM MOVING FROM THE WESTERN HIGH PLAINS
INTO THE DAKOTAS FROM FRIDAY NIGHT THROUGH THE DAY ON SATURDAY.
STRONG LOW TO MID-LEVEL FRONTOGENESIS IS INDICATED ALONG THE
ADVANCING COLD FRONT. WITH THE STRONG CAPPING AND VERY WEAK
INSTABILITY AHEAD OF THE FRONT...WE EXPECT THE PRECIPITATION
ASSOCIATED WITH THE STORM SYSTEM TO BE ALONG AND BEHIND THE COLD
FRONT ASSOCIATED WITH THE PREVIOUSLY MENTIONED FRONTOGENESIS.
RAINFALL FOR OUR CWA APPEARS TO BE MAXIMIZED IN TWO AREAS...ONE
ALONG THE TRACK OF THE SURFACE LOW OVER NE NEB...AND SECOND OVER
SE NEB TO THE SOUTH OF THE TRACK OF THE MID LEVEL JET MAX. THE
MAIN CHANGE TO THE FORECAST IN POPS REGARD TO THIS SYSTEM WAS TO
SLOW THE TIMING ON FRIDAY NIGHT AND ALSO TO LOWER POPS ALONG THE
HIGHWAY 30 CORRIDOR BETWEEN THESE TWO FAVORED AREAS. THE FRONT
AND ASSOCIATED PRECIP WILL BE RAPIDLY EXITING THE AREAS ON SAT
MORNING. THE REST OF THE WEEKEND LOOKS QUIET AND SEASONABLE.
THE LONG RANGE MODELS ARE IN FAIR AGREEMENT IN ANOTHER SYSTEM
TOWARD THE END OF THE FORECAST PERIOD...BUT THERE REMAINS A GOOD
DEAL OF TIMING DIFFERENCES IN THE PRECIP AND ASSOCIATED FRONT.
CURRENTLY WE TRENDED TOWARD THE SLOWER EC BUT DID INCLUDE SOME
SHOWERS FOR WED NIGHT AND THU...BUT IT COULD END UP BEING JUST
PAST THE END OF THIS FORECAST PERIOD. OTHERWISE TEMPERATURES WILL
BE TRENDED WARMER AGAIN FOR NEXT WEEK WITH SOME 80S POSSIBLE ON
MON-WED.
BOUSTEAD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1142 AM MDT FRI SEP 27 2013
.AVIATION...
18Z TAF CYCLE
SURFACE COLD FRONT SLICING ACROSS CENTRAL PORTIONS OF THE STATE AS
OF THIS WRITING. THIS FRONT WILL CONTINUE EASTWARD THROUGH THE
REST OF THE DAY. THUS...WIND SHIFTS WILL BE EXPECTED TODAY AND
TONIGHT. SIGNIFICANT CLOUD BANK FOUND AHEAD AND ALONG THE MAIN
UPPER FRONT. THIS WILL IMPACT CENTRAL AND EASTERN TERMINAL SITES
THROUGH MOST OF THE DAY. EMBEDDED SHOWERS HAVE DWINDLED SOME BUT
SAF AND LVS COULD EXPERIENCE SOME EFFECT. GUP AND FMN WILL SEE A
SHARP CLEARING TRENDING EARLY THIS AFTERNOON AS THE UPPER FRONT
EDGES EASTWARD. THIS IS VERIFIED USING VISIBLE SATELLITE IMAGERY.
FAST MOVING STORMS ARE STILL POSSIBLE FOR PORTIONS OF THE EAST.
WILL MONITOR ROW AND TCC CLOSELY. MTN TOP OBSCD WILL BE PREVALENT
ACROSS THE NORTHERN MOUNTAINS THROUGH MOST OF THE DAY.
50
&&
.PREV DISCUSSION...1023 AM MDT FRI SEP 27 2013...
UPDATED FORECAST TO DECREASE 1ST PERIOD MAX TEMPS BY AN AVERAGE 5
DEGREES BEHIND THE FRONT...WHICH IS CURRENTLY LOCATED ALONG A
TAOS TO ALBUQUERQUE TO MAGDALENA LINE. ALSO INCREASED 1ST PERIOD
SKY COVER CENTRAL AND WEST GIVEN THE LATEST VISIBLE SATELLITE
IMAGERY SHOWING POST-FRONTAL CLOUDS AND A FEW LIGHT SHOWERS.
OTHERWISE...FORECAST ON TRACK.
11
.PREV DISCUSSION...301 AM MDT FRI SEP 27 2013...
COMPLICATED WEATHER SCENARIO FOR THE NEXT 24-30 HOURS OR SO. STRONG
WINDS AND POTENTIALLY STRONG THUNDERSTORMS ACROSS THE EAST THIS
AFTERNOON AND EVENING WILL BE FOLLOWED BY MUCH COLDER TEMPERATURES
TONIGHT...ESPECIALLY ACROSS THE NORTH AND WEST. WIDESPREAD FREEZING
TEMPERATURES ARE LOOKING LIKELY.
BUT FIRST...SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF THE EASTERN
PLAINS WHERE SOME SUB-TROPICAL MOISTURE HAS ADVECTED NORTHWARD OVER
THE LAST 18 HOURS. SHOWERS HAVE ALSO BEEN NOTED ACROSS MUCH OF
ARIZONA AHEAD OF THE UPPER LEVEL STORM SYSTEM...AND THIS QPF WAS NOT
HANDLED WELL BY MODELS AT ALL. THEREFORE...CONFIDENCE IS NOT HIGH
ON WHERE PRECIPITATION WILL TRANSPIRE TODAY ACROSS NM. SEEMS LIKE
THE GFS AND THE HRRR HAVE PICKED UP ON THE LINE OF SHOWERS ACROSS
THE EAST...SO HAVE LARGELY GONE WITH A BLEND OF THOSE TWO MODELS FOR
THE REST OF THE DAY. STILL EXPECT SHOWERS TO EXPAND ACROSS THE N/NW.
COULD BE SOME LIGHT SNOW ACROSS THE HIGH PEAKS OF THE NORTHERN
MOUNTAINS THIS MORNING AS WELL. OTHERWISE... MAIN CONCERN WITH
PRECIP FOR TODAY IS THIS AFTERNOON WHEN THE ATMOSPHERE DESTABILIZES
ACROSS THE PLAINS AHEAD OF THE COLD FRONT/DRYLINE. COULD SEE SOME
STRONG STORMS WITH HAIL AND GUSTY WINDS NEAR THE TEXAS BORDER.
ADDITIONALLY...MIXING HEIGHTS ARE NOT TERRIBLY HIGH...BUT A 999MB
SFC LOW ACROSS SE CO WILL RESULT IN A STRONG PRESSURE GRADIENT
ACROSS NE NM. HAVE OPTED TO GO WITH A LOW END WIND ADVISORY FOR
AREAS AROUND THE I-25 CORRIDOR. CONSIDERED ADDING UNION COUNTY AS
WELL...BUT WILL LET DAY SHIFT MONITOR TRENDS.
AS THE PACIFIC COLD FRONT SWEEPS FROM WEST TO EAST...MUCH COOLER
AND DRIER AIR WILL FILTER INTO THE STATE...ALLOWING TEMPERATURES
TO PLUMMET TONIGHT...ESPECIALLY ACROSS THE NORTH AND WEST.
WIDESPREAD FREEZING TEMPERATURES APPEAR LIKELY. HARD FREEZES ARE
POSSIBLE FOR MANY NORTHERN AND WESTERN MOUNTAIN LOCALES...AS WELL
AS THE UPPER RIO GRANDE VALLEY AND NEAR GALLUP AND GRANTS. HAVE
OPTED TO GO WITH A FREEZE WATCH FOR THE NORTHWEST PLATEAU AND
LOWER CHAMA RIVER VALLEY...ZONES 501 AND 517...WHERE LOW TEMPS BTW
29 AND 33 APPEAR LIKELY. OTHER AREAS WILL BE TEETERING CLOSE TO
THE FREEZING MARK AS WELL. HAVE OPTED TO GO JUST ABOVE FREEZING
FOR SANTA FE...DUE TO A DECENT DRAINAGE WIND MUCH OF THE
NIGHT....AS WELL AS RATON AND LAS VEGAS...WHERE NW WINDS MAY HELP
KEEP TEMPS UP A BIT OVERNIGHT. MORIARTY WILL ALSO BE CLOSE.
BACK DOOR COLD FRONT WILL CLEAR THE EASTERN PLAINS BY SATURDAY
MORNING. WILL SEE SOME RETURN FLOW ACROSS THE SOUTHEAST...BUT NOT
EXPECTING ADDITIONAL PRECIP. OTHERWISE ZONAL FLOW WITH TEMPERATURES
5 TO 10 DEGREES BELOW NORMAL. QUIET CONDITIONS WILL PERSIST THROUGH
MUCH OF THE WEEK WITH TEMPERATURES WARMING BACK TO NEAR NORMAL. THE
NEXT STORM SYSTEM MAY BEGIN IMPACTING THE STATE AS EARLY AS THURSDAY
WITH WINDS INCREASING ONCE AGAIN. GFS REMAINS MUCH FASTER WITH THE
SYSTEM PASSAGE...AS THE ECMWF CLOSES OFF THE SYSTEM OVER NORTHERN
ARIZONA AND KEEPS IT THERE THROUGH MUCH OF SATURDAY. THUS...MUCH
UNCERTAINTY IN THE EXTENDED...BUT INCREASING WINDS WITH A CHANCE FOR
PRECIP ACROSS THE NORTH AND PERHAPS EAST APPEAR POSSIBLE.
34
.FIRE WEATHER...
A POTENT COLD FRONT WILL SWEEP ACROSS NEW MEXICO TODAY USHERING IN
MUCH COOLER AIR...ESPECIALLY IN THE WEST. MOISTURE ALONG AND AHEAD
OF THE FRONT WILL COMBINE TO PRODUCE A ROUND OF SHOWERS AND
THUNDERSTORMS TODAY. SPOTTY WETTING RAINS WILL BE NOTED OVER THE
NORTHWEST THIS MORNING...WITH MORE WIDESPREAD WETTING RAINS OVER
THE FAR EASTERN PLAINS THIS AFTERNOON INTO THIS EVENING. WINDY
CONDITIONS WILL BE PRESENT OVER THE NORTHEAST WITH A WIND ADVISORY
FOR THE NORTHEAST HIGHLANDS LATE THIS MORNING THROUGH THE AFTERNOON.
THE MOISTURE AND COLD FRONT WILL CREATE LOWER TEMPERATURES AND
HIGHER RH VALUES TODAY...WHILE VENTILATION WILL BE MOSTLY
EXCELLENT...ALTHOUGH LOWERING IN THE WEST DURING THE DAY.
A TROUGH OF LOW PRESSURE WILL CROSS THE STATE TONIGHT WITH THE
CHILLIEST TEMPERATURES OF THE SEASON SO FAR FOR EARLY SATURDAY
MORNING. SOME LOWLAND LOCATIONS MAY SEE THEIR FIRST FREEZE...SUCH AS
FARMINGTON AND ESPANOLA. A FREEZE WATCH HAS BEEN ISSUED FOR THESE
LOCATIONS. SHOWERS WILL LINGER OVER THE SOUTHEAST AREA WELL INTO THE
NIGHT. A FEW SNOW SHOWERS MAY BE FOUND OVER THE HIGH PEAKS OF THE
NORTHERN MOUNTAINS THIS EVENING.
MUCH COOLER THAN NORMAL TEMPERATURES PROJECTED FOR SATURDAY AS THE
MID LEVEL DRY SLOT STAYS OVER PORTIONS OF THE FORECAST AREA. THE
VENTILATION WILL TAKE QUITE A HIT SATURDAY DUE TO POST COLD FRONTAL
INVERSION EFFECTS. LOTS OF POOR RATINGS ARE CURRENTLY SHOWING UP ON
SATURDAY FOR THE WEST. ANOTHER CHILLY NIGHT IS EXPECTED SATURDAY
NIGHT. WINDS WILL DIE DOWN AND ALLOW FOR EFFICIENT RADIATIONAL
COOLING. THE LOW LEVEL INVERSION WILL FORM QUITE NICELY ALONG THE
MIDSLOPES.
WEATHER MODELS CONTINUE TO SHOW A DRY ZONAL FLOW OVER THE FORECAST
AREA SUNDAY INTO THE MIDDLE OF NEXT WEEK. VENTILATION WILL GRADUALLY
IMPROVE AS MIXING HEIGHTS AND SURFACE TEMPERATURES SLOWLY INCREASE.
ONE EXCEPTION MAY BE THE NORTHEAST ON TUESDAY AS A WEAK TROUGH ALOFT
AND SURFACE COLD FRONT BRUSH THIS AREA.
MODELS DIVERGE GREATLY IN THE EXTENDED FORECAST. THE GFS BRINGS A
PROGRESSIVE TROUGH ACROSS NEW MEXICO FRIDAY...WHILE THE EUROPEAN HAS
A CLOSED LOW OVER THE FOUR CORNERS AREA SATURDAY...FINALLY LIFTING
THE TROUGH AWAY FROM NEW MEXICO SUNDAY. WHAT WE ARE MOST CONFIDENT
ON IS THURSDAY WILL BRING INCREASING WINDS AND FRIDAY WILL BE
COOLER. DURING THIS TIME THERE MAY BE SHOWER ACTIVITY OVER THE
NORTHERN MOUNTAINS AND NORTHEAST.
CHJ
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR THE
FOLLOWING ZONES...NMZ501-517.
WIND ADVISORY UNTIL 6 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...
NMZ515-527>529.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1023 AM MDT FRI SEP 27 2013
.UPDATE...
UPDATED FORECAST TO DECREASE 1ST PERIOD MAX TEMPS BY AN AVERAGE 5
DEGREES BEHIND THE FRONT...WHICH IS CURRENTLY LOCATED ALONG A
TAOS TO ALBUQUERQUE TO MAGDALENA LINE. ALSO INCREASED 1ST PERIOD
SKY COVER CENTRAL AND WEST GIVEN THE LATEST VISIBLE SATELLITE
IMAGERY SHOWING POST-FRONTAL CLOUDS AND A FEW LIGHT SHOWERS.
OTHERWISE...FORECAST ON TRACK.
11
&&
.PREV DISCUSSION...547 AM MDT FRI SEP 27 2013...
.AVIATION...
12Z TAF CYCLE
STRONG COLD FRONT TO CROSS THE STATE TODAY INTO TONIGHT. WIND GUSTS
TO 4O OR 45 KTS ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO
MOUNTAINS TO THE NORTHEAST AND FAR NORTHEAST HIGHLANDS AND RATON
RIDGE...JOHNSON MESA. ALSO WIND GUSTS TO 45 KTS POSSIBLE WITH THE
STRONGER THUNDERSTORMS NEAR THE TEXAS BORDER. VFR CONDITIONS NEXT
24 HOURS EXCEPT BRIEF MVFR CIGS POSSIBLE IN A THUNDERSTORM ACROSS
THE EAST BETWEEN 18Z AND 02Z AND BRIEF MVFR VSBYS IN SOME BLOWING
DUST IN THE NORTHEAST BETWEEN 18Z AND 23Z. VFR CONDITIONS EXPECTED
AT ALL TERMINAL SITES.
.PREV DISCUSSION...301 AM MDT FRI SEP 27 2013...
COMPLICATED WEATHER SCENARIO FOR THE NEXT 24-30 HOURS OR SO. STRONG
WINDS AND POTENTIALLY STRONG THUNDERSTORMS ACROSS THE EAST THIS
AFTERNOON AND EVENING WILL BE FOLLOWED BY MUCH COLDER TEMPERATURES
TONIGHT...ESPECIALLY ACROSS THE NORTH AND WEST. WIDESPREAD FREEZING
TEMPERATURES ARE LOOKING LIKELY.
BUT FIRST...SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF THE EASTERN
PLAINS WHERE SOME SUB-TROPICAL MOISTURE HAS ADVECTED NORTHWARD OVER
THE LAST 18 HOURS. SHOWERS HAVE ALSO BEEN NOTED ACROSS MUCH OF
ARIZONA AHEAD OF THE UPPER LEVEL STORM SYSTEM...AND THIS QPF WAS NOT
HANDLED WELL BY MODELS AT ALL. THEREFORE...CONFIDENCE IS NOT HIGH
ON WHERE PRECIPITATION WILL TRANSPIRE TODAY ACROSS NM. SEEMS LIKE
THE GFS AND THE HRRR HAVE PICKED UP ON THE LINE OF SHOWERS ACROSS
THE EAST...SO HAVE LARGELY GONE WITH A BLEND OF THOSE TWO MODELS FOR
THE REST OF THE DAY. STILL EXPECT SHOWERS TO EXPAND ACROSS THE N/NW.
COULD BE SOME LIGHT SNOW ACROSS THE HIGH PEAKS OF THE NORTHERN
MOUNTAINS THIS MORNING AS WELL. OTHERWISE... MAIN CONCERN WITH
PRECIP FOR TODAY IS THIS AFTERNOON WHEN THE ATMOSPHERE DESTABILIZES
ACROSS THE PLAINS AHEAD OF THE COLD FRONT/DRYLINE. COULD SEE SOME
STRONG STORMS WITH HAIL AND GUSTY WINDS NEAR THE TEXAS BORDER.
ADDITIONALLY...MIXING HEIGHTS ARE NOT TERRIBLY HIGH...BUT A 999MB
SFC LOW ACROSS SE CO WILL RESULT IN A STRONG PRESSURE GRADIENT
ACROSS NE NM. HAVE OPTED TO GO WITH A LOW END WIND ADVISORY FOR
AREAS AROUND THE I-25 CORRIDOR. CONSIDERED ADDING UNION COUNTY AS
WELL...BUT WILL LET DAY SHIFT MONITOR TRENDS.
AS THE PACIFIC COLD FRONT SWEEPS FROM WEST TO EAST...MUCH COOLER
AND DRIER AIR WILL FILTER INTO THE STATE...ALLOWING TEMPERATURES
TO PLUMMET TONIGHT...ESPECIALLY ACROSS THE NORTH AND WEST.
WIDESPREAD FREEZING TEMPERATURES APPEAR LIKELY. HARD FREEZES ARE
POSSIBLE FOR MANY NORTHERN AND WESTERN MOUNTAIN LOCALES...AS WELL
AS THE UPPER RIO GRANDE VALLEY AND NEAR GALLUP AND GRANTS. HAVE
OPTED TO GO WITH A FREEZE WATCH FOR THE NORTHWEST PLATEAU AND
LOWER CHAMA RIVER VALLEY...ZONES 501 AND 517...WHERE LOW TEMPS BTW
29 AND 33 APPEAR LIKELY. OTHER AREAS WILL BE TEETERING CLOSE TO
THE FREEZING MARK AS WELL. HAVE OPTED TO GO JUST ABOVE FREEZING
FOR SANTA FE...DUE TO A DECENT DRAINAGE WIND MUCH OF THE
NIGHT....AS WELL AS RATON AND LAS VEGAS...WHERE NW WINDS MAY HELP
KEEP TEMPS UP A BIT OVERNIGHT. MORIARTY WILL ALSO BE CLOSE.
BACK DOOR COLD FRONT WILL CLEAR THE EASTERN PLAINS BY SATURDAY
MORNING. WILL SEE SOME RETURN FLOW ACROSS THE SOUTHEAST...BUT NOT
EXPECTING ADDITIONAL PRECIP. OTHERWISE ZONAL FLOW WITH TEMPERATURES
5 TO 10 DEGREES BELOW NORMAL. QUIET CONDITIONS WILL PERSIST THROUGH
MUCH OF THE WEEK WITH TEMPERATURES WARMING BACK TO NEAR NORMAL. THE
NEXT STORM SYSTEM MAY BEGIN IMPACTING THE STATE AS EARLY AS THURSDAY
WITH WINDS INCREASING ONCE AGAIN. GFS REMAINS MUCH FASTER WITH THE
SYSTEM PASSAGE...AS THE ECMWF CLOSES OFF THE SYSTEM OVER NORTHERN
ARIZONA AND KEEPS IT THERE THROUGH MUCH OF SATURDAY. THUS...MUCH
UNCERTAINTY IN THE EXTENDED...BUT INCREASING WINDS WITH A CHANCE FOR
PRECIP ACROSS THE NORTH AND PERHAPS EAST APPEAR POSSIBLE.
34
.FIRE WEATHER...
A POTENT COLD FRONT WILL SWEEP ACROSS NEW MEXICO TODAY USHERING IN
MUCH COOLER AIR...ESPECIALLY IN THE WEST. MOISTURE ALONG AND AHEAD
OF THE FRONT WILL COMBINE TO PRODUCE A ROUND OF SHOWERS AND
THUNDERSTORMS TODAY. SPOTTY WETTING RAINS WILL BE NOTED OVER THE
NORTHWEST THIS MORNING...WITH MORE WIDESPREAD WETTING RAINS OVER
THE FAR EASTERN PLAINS THIS AFTERNOON INTO THIS EVENING. WINDY
CONDITIONS WILL BE PRESENT OVER THE NORTHEAST WITH A WIND ADVISORY
FOR THE NORTHEAST HIGHLANDS LATE THIS MORNING THROUGH THE AFTERNOON.
THE MOISTURE AND COLD FRONT WILL CREATE LOWER TEMPERATURES AND
HIGHER RH VALUES TODAY...WHILE VENTILATION WILL BE MOSTLY
EXCELLENT...ALTHOUGH LOWERING IN THE WEST DURING THE DAY.
A TROUGH OF LOW PRESSURE WILL CROSS THE STATE TONIGHT WITH THE
CHILLIEST TEMPERATURES OF THE SEASON SO FAR FOR EARLY SATURDAY
MORNING. SOME LOWLAND LOCATIONS MAY SEE THEIR FIRST FREEZE...SUCH AS
FARMINGTON AND ESPANOLA. A FREEZE WATCH HAS BEEN ISSUED FOR THESE
LOCATIONS. SHOWERS WILL LINGER OVER THE SOUTHEAST AREA WELL INTO THE
NIGHT. A FEW SNOW SHOWERS MAY BE FOUND OVER THE HIGH PEAKS OF THE
NORTHERN MOUNTAINS THIS EVENING.
MUCH COOLER THAN NORMAL TEMPERATURES PROJECTED FOR SATURDAY AS THE
MID LEVEL DRY SLOT STAYS OVER PORTIONS OF THE FORECAST AREA. THE
VENTILATION WILL TAKE QUITE A HIT SATURDAY DUE TO POST COLD FRONTAL
INVERSION EFFECTS. LOTS OF POOR RATINGS ARE CURRENTLY SHOWING UP ON
SATURDAY FOR THE WEST. ANOTHER CHILLY NIGHT IS EXPECTED SATURDAY
NIGHT. WINDS WILL DIE DOWN AND ALLOW FOR EFFICIENT RADIATIONAL
COOLING. THE LOW LEVEL INVERSION WILL FORM QUITE NICELY ALONG THE
MIDSLOPES.
WEATHER MODELS CONTINUE TO SHOW A DRY ZONAL FLOW OVER THE FORECAST
AREA SUNDAY INTO THE MIDDLE OF NEXT WEEK. VENTILATION WILL GRADUALLY
IMPROVE AS MIXING HEIGHTS AND SURFACE TEMPERATURES SLOWLY INCREASE.
ONE EXCEPTION MAY BE THE NORTHEAST ON TUESDAY AS A WEAK TROUGH ALOFT
AND SURFACE COLD FRONT BRUSH THIS AREA.
MODELS DIVERGE GREATLY IN THE EXTENDED FORECAST. THE GFS BRINGS A
PROGRESSIVE TROUGH ACROSS NEW MEXICO FRIDAY...WHILE THE EUROPEAN HAS
A CLOSED LOW OVER THE FOUR CORNERS AREA SATURDAY...FINALLY LIFTING
THE TROUGH AWAY FROM NEW MEXICO SUNDAY. WHAT WE ARE MOST CONFIDENT
ON IS THURSDAY WILL BRING INCREASING WINDS AND FRIDAY WILL BE
COOLER. DURING THIS TIME THERE MAY BE SHOWER ACTIVITY OVER THE
NORTHERN MOUNTAINS AND NORTHEAST.
CHJ
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR THE
FOLLOWING ZONES...NMZ501-517.
WIND ADVISORY UNTIL 6 PM MDT THIS EVENING FOR THE FOLLOWING ZONES...
NMZ515-527>529.
&&
$$
11
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
547 AM MDT FRI SEP 27 2013
.AVIATION...
12Z TAF CYCLE
STRONG COLD FRONT TO CROSS THE STATE TODAY INTO TONIGHT. WIND GUSTS
TO 4O OR 45 KTS ALONG THE EAST SLOPES OF THE SANGRE DE CRISTO
MOUNTAINS TO THE NORTHEAST AND FAR NORTHEAST HIGHLANDS AND RATON
RIDGE...JOHNSON MESA. ALSO WIND GUSTS TO 45 KTS POSSIBLE WITH THE
STRONGER THUNDERSTORMS NEAR THE TEXAS BORDER. VFR CONDITIONS NEXT
24 HOURS EXCEPT BRIEF MVFR CIGS POSSIBLE IN A THUNDERSTORM ACROSS
THE EAST BETWEEN 18Z AND 02Z AND BRIEF MVFR VSBYS IN SOME BLOWING
DUST IN THE NORTHEAST BETWEEN 18Z AND 23Z. VFR CONDITIONS EXPECTED
AT ALL TERMINAL SITES.
&&
.PREV DISCUSSION...301 AM MDT FRI SEP 27 2013...
COMPLICATED WEATHER SCENARIO FOR THE NEXT 24-30 HOURS OR SO. STRONG
WINDS AND POTENTIALLY STRONG THUNDERSTORMS ACROSS THE EAST THIS
AFTERNOON AND EVENING WILL BE FOLLOWED BY MUCH COLDER TEMPERATURES
TONIGHT...ESPECIALLY ACROSS THE NORTH AND WEST. WIDESPREAD FREEZING
TEMPERATURES ARE LOOKING LIKELY.
BUT FIRST...SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF THE EASTERN
PLAINS WHERE SOME SUB-TROPICAL MOISTURE HAS ADVECTED NORTHWARD OVER
THE LAST 18 HOURS. SHOWERS HAVE ALSO BEEN NOTED ACROSS MUCH OF
ARIZONA AHEAD OF THE UPPER LEVEL STORM SYSTEM...AND THIS QPF WAS NOT
HANDLED WELL BY MODELS AT ALL. THEREFORE...CONFIDENCE IS NOT HIGH
ON WHERE PRECIPITATION WILL TRANSPIRE TODAY ACROSS NM. SEEMS LIKE
THE GFS AND THE HRRR HAVE PICKED UP ON THE LINE OF SHOWERS ACROSS
THE EAST...SO HAVE LARGELY GONE WITH A BLEND OF THOSE TWO MODELS FOR
THE REST OF THE DAY. STILL EXPECT SHOWERS TO EXPAND ACROSS THE N/NW.
COULD BE SOME LIGHT SNOW ACROSS THE HIGH PEAKS OF THE NORTHERN
MOUNTAINS THIS MORNING AS WELL. OTHERWISE... MAIN CONCERN WITH
PRECIP FOR TODAY IS THIS AFTERNOON WHEN THE ATMOSPHERE DESTABILIZES
ACROSS THE PLAINS AHEAD OF THE COLD FRONT/DRYLINE. COULD SEE SOME
STRONG STORMS WITH HAIL AND GUSTY WINDS NEAR THE TEXAS BORDER.
ADDITIONALLY...MIXING HEIGHTS ARE NOT TERRIBLY HIGH...BUT A 999MB
SFC LOW ACROSS SE CO WILL RESULT IN A STRONG PRESSURE GRADIENT
ACROSS NE NM. HAVE OPTED TO GO WITH A LOW END WIND ADVISORY FOR
AREAS AROUND THE I-25 CORRIDOR. CONSIDERED ADDING UNION COUNTY AS
WELL...BUT WILL LET DAY SHIFT MONITOR TRENDS.
AS THE PACIFIC COLD FRONT SWEEPS FROM WEST TO EAST...MUCH COOLER
AND DRIER AIR WILL FILTER INTO THE STATE...ALLOWING TEMPERATURES
TO PLUMMET TONIGHT...ESPECIALLY ACROSS THE NORTH AND WEST.
WIDESPREAD FREEZING TEMPERATURES APPEAR LIKELY. HARD FREEZES ARE
POSSIBLE FOR MANY NORTHERN AND WESTERN MOUNTAIN LOCALES...AS WELL
AS THE UPPER RIO GRANDE VALLEY AND NEAR GALLUP AND GRANTS. HAVE
OPTED TO GO WITH A FREEZE WATCH FOR THE NORTHWEST PLATEAU AND
LOWER CHAMA RIVER VALLEY...ZONES 501 AND 517...WHERE LOW TEMPS BTW
29 AND 33 APPEAR LIKELY. OTHER AREAS WILL BE TEETERING CLOSE TO
THE FREEZING MARK AS WELL. HAVE OPTED TO GO JUST ABOVE FREEZING
FOR SANTA FE...DUE TO A DECENT DRAINAGE WIND MUCH OF THE
NIGHT....AS WELL AS RATON AND LAS VEGAS...WHERE NW WINDS MAY HELP
KEEP TEMPS UP A BIT OVERNIGHT. MORIARTY WILL ALSO BE CLOSE.
BACK DOOR COLD FRONT WILL CLEAR THE EASTERN PLAINS BY SATURDAY
MORNING. WILL SEE SOME RETURN FLOW ACROSS THE SOUTHEAST...BUT NOT
EXPECTING ADDITIONAL PRECIP. OTHERWISE ZONAL FLOW WITH TEMPERATURES
5 TO 10 DEGREES BELOW NORMAL. QUIET CONDITIONS WILL PERSIST THROUGH
MUCH OF THE WEEK WITH TEMPERATURES WARMING BACK TO NEAR NORMAL. THE
NEXT STORM SYSTEM MAY BEGIN IMPACTING THE STATE AS EARLY AS THURSDAY
WITH WINDS INCREASING ONCE AGAIN. GFS REMAINS MUCH FASTER WITH THE
SYSTEM PASSAGE...AS THE ECMWF CLOSES OFF THE SYSTEM OVER NORTHERN
ARIZONA AND KEEPS IT THERE THROUGH MUCH OF SATURDAY. THUS...MUCH
UNCERTAINTY IN THE EXTENDED...BUT INCREASING WINDS WITH A CHANCE FOR
PRECIP ACROSS THE NORTH AND PERHAPS EAST APPEAR POSSIBLE.
34
.FIRE WEATHER...
A POTENT COLD FRONT WILL SWEEP ACROSS NEW MEXICO TODAY USHERING IN
MUCH COOLER AIR...ESPECIALLY IN THE WEST. MOISTURE ALONG AND AHEAD
OF THE FRONT WILL COMBINE TO PRODUCE A ROUND OF SHOWERS AND
THUNDERSTORMS TODAY. SPOTTY WETTING RAINS WILL BE NOTED OVER THE
NORTHWEST THIS MORNING...WITH MORE WIDESPREAD WETTING RAINS OVER
THE FAR EASTERN PLAINS THIS AFTERNOON INTO THIS EVENING. WINDY
CONDITIONS WILL BE PRESENT OVER THE NORTHEAST WITH A WIND ADVISORY
FOR THE NORTHEAST HIGHLANDS LATE THIS MORNING THROUGH THE AFTERNOON.
THE MOISTURE AND COLD FRONT WILL CREATE LOWER TEMPERATURES AND
HIGHER RH VALUES TODAY...WHILE VENTILATION WILL BE MOSTLY
EXCELLENT...ALTHOUGH LOWERING IN THE WEST DURING THE DAY.
A TROUGH OF LOW PRESSURE WILL CROSS THE STATE TONIGHT WITH THE
CHILLIEST TEMPERATURES OF THE SEASON SO FAR FOR EARLY SATURDAY
MORNING. SOME LOWLAND LOCATIONS MAY SEE THEIR FIRST FREEZE...SUCH AS
FARMINGTON AND ESPANOLA. A FREEZE WATCH HAS BEEN ISSUED FOR THESE
LOCATIONS. SHOWERS WILL LINGER OVER THE SOUTHEAST AREA WELL INTO THE
NIGHT. A FEW SNOW SHOWERS MAY BE FOUND OVER THE HIGH PEAKS OF THE
NORTHERN MOUNTAINS THIS EVENING.
MUCH COOLER THAN NORMAL TEMPERATURES PROJECTED FOR SATURDAY AS THE
MID LEVEL DRY SLOT STAYS OVER PORTIONS OF THE FORECAST AREA. THE
VENTILATION WILL TAKE QUITE A HIT SATURDAY DUE TO POST COLD FRONTAL
INVERSION EFFECTS. LOTS OF POOR RATINGS ARE CURRENTLY SHOWING UP ON
SATURDAY FOR THE WEST. ANOTHER CHILLY NIGHT IS EXPECTED SATURDAY
NIGHT. WINDS WILL DIE DOWN AND ALLOW FOR EFFICIENT RADIATIONAL
COOLING. THE LOW LEVEL INVERSION WILL FORM QUITE NICELY ALONG THE
MIDSLOPES.
WEATHER MODELS CONTINUE TO SHOW A DRY ZONAL FLOW OVER THE FORECAST
AREA SUNDAY INTO THE MIDDLE OF NEXT WEEK. VENTILATION WILL GRADUALLY
IMPROVE AS MIXING HEIGHTS AND SURFACE TEMPERATURES SLOWLY INCREASE.
ONE EXCEPTION MAY BE THE NORTHEAST ON TUESDAY AS A WEAK TROUGH ALOFT
AND SURFACE COLD FRONT BRUSH THIS AREA.
MODELS DIVERGE GREATLY IN THE EXTENDED FORECAST. THE GFS BRINGS A
PROGRESSIVE TROUGH ACROSS NEW MEXICO FRIDAY...WHILE THE EUROPEAN HAS
A CLOSED LOW OVER THE FOUR CORNERS AREA SATURDAY...FINALLY LIFTING
THE TROUGH AWAY FROM NEW MEXICO SUNDAY. WHAT WE ARE MOST CONFIDENT
ON IS THURSDAY WILL BRING INCREASING WINDS AND FRIDAY WILL BE
COOLER. DURING THIS TIME THERE MAY BE SHOWER ACTIVITY OVER THE
NORTHERN MOUNTAINS AND NORTHEAST.
CHJ
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR THE
FOLLOWING ZONES...NMZ501-517.
WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM MDT THIS EVENING FOR
THE FOLLOWING ZONES...NMZ515-527>529.
&&
$$
40
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
301 AM MDT FRI SEP 27 2013
.DISCUSSION...
COMPLICATED WEATHER SCENARIO FOR THE NEXT 24-30 HOURS OR SO. STRONG
WINDS AND POTENTIALLY STRONG THUNDERSTORMS ACROSS THE EAST THIS
AFTERNOON AND EVENING WILL BE FOLLOWED BY MUCH COLDER TEMPERATURES
TONIGHT...ESPECIALLY ACROSS THE NORTH AND WEST. WIDESPREAD FREEZING
TEMPERATURES ARE LOOKING LIKELY.
BUT FIRST...SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF THE EASTERN
PLAINS WHERE SOME SUB-TROPICAL MOISTURE HAS ADVECTED NORTHWARD OVER
THE LAST 18 HOURS. SHOWERS HAVE ALSO BEEN NOTED ACROSS MUCH OF
ARIZONA AHEAD OF THE UPPER LEVEL STORM SYSTEM...AND THIS QPF WAS NOT
HANDLED WELL BY MODELS AT ALL. THEREFORE...CONFIDENCE IS NOT HIGH
ON WHERE PRECIPITATION WILL TRANSPIRE TODAY ACROSS NM. SEEMS LIKE
THE GFS AND THE HRRR HAVE PICKED UP ON THE LINE OF SHOWERS ACROSS
THE EAST...SO HAVE LARGELY GONE WITH A BLEND OF THOSE TWO MODELS FOR
THE REST OF THE DAY. STILL EXPECT SHOWERS TO EXPAND ACROSS THE N/NW.
COULD BE SOME LIGHT SNOW ACROSS THE HIGH PEAKS OF THE NORTHERN
MOUNTAINS THIS MORNING AS WELL. OTHERWISE... MAIN CONCERN WITH
PRECIP FOR TODAY IS THIS AFTERNOON WHEN THE ATMOSPHERE DESTABILIZES
ACROSS THE PLAINS AHEAD OF THE COLD FRONT/DRYLINE. COULD SEE SOME
STRONG STORMS WITH HAIL AND GUSTY WINDS NEAR THE TEXAS BORDER.
ADDITIONALLY...MIXING HEIGHTS ARE NOT TERRIBLY HIGH...BUT A 999MB
SFC LOW ACROSS SE CO WILL RESULT IN A STRONG PRESSURE GRADIENT
ACROSS NE NM. HAVE OPTED TO GO WITH A LOW END WIND ADVISORY FOR
AREAS AROUND THE I-25 CORRIDOR. CONSIDERED ADDING UNION COUNTY AS
WELL...BUT WILL LET DAY SHIFT MONITOR TRENDS.
AS THE PACIFIC COLD FRONT SWEEPS FROM WEST TO EAST...MUCH COOLER
AND DRIER AIR WILL FILTER INTO THE STATE...ALLOWING TEMPERATURES
TO PLUMMET TONIGHT...ESPECIALLY ACROSS THE NORTH AND WEST.
WIDESPREAD FREEZING TEMPERATURES APPEAR LIKELY. HARD FREEZES ARE
POSSIBLE FOR MANY NORTHERN AND WESTERN MOUNTAIN LOCALES...AS WELL
AS THE UPPER RIO GRANDE VALLEY AND NEAR GALLUP AND GRANTS. HAVE
OPTED TO GO WITH A FREEZE WATCH FOR THE NORTHWEST PLATEAU AND
LOWER CHAMA RIVER VALLEY...ZONES 501 AND 517...WHERE LOW TEMPS BTW
29 AND 33 APPEAR LIKELY. OTHER AREAS WILL BE TEETERING CLOSE TO
THE FREEZING MARK AS WELL. HAVE OPTED TO GO JUST ABOVE FREEZING
FOR SANTA FE...DUE TO A DECENT DRAINAGE WIND MUCH OF THE
NIGHT....AS WELL AS RATON AND LAS VEGAS...WHERE NW WINDS MAY HELP
KEEP TEMPS UP A BIT OVERNIGHT. MORIARTY WILL ALSO BE CLOSE.
BACK DOOR COLD FRONT WILL CLEAR THE EASTERN PLAINS BY SATURDAY
MORNING. WILL SEE SOME RETURN FLOW ACROSS THE SOUTHEAST...BUT NOT
EXPECTING ADDITIONAL PRECIP. OTHERWISE ZONAL FLOW WITH TEMPERATURES
5 TO 10 DEGREES BELOW NORMAL. QUIET CONDITIONS WILL PERSIST THROUGH
MUCH OF THE WEEK WITH TEMPERATURES WARMING BACK TO NEAR NORMAL. THE
NEXT STORM SYSTEM MAY BEGIN IMPACTING THE STATE AS EARLY AS THURSDAY
WITH WINDS INCREASING ONCE AGAIN. GFS REMAINS MUCH FASTER WITH THE
SYSTEM PASSAGE...AS THE ECMWF CLOSES OFF THE SYSTEM OVER NORTHERN
ARIZONA AND KEEPS IT THERE THROUGH MUCH OF SATURDAY. THUS...MUCH
UNCERTAINTY IN THE EXTENDED...BUT INCREASING WINDS WITH A CHANCE FOR
PRECIP ACROSS THE NORTH AND PERHAPS EAST APPEAR POSSIBLE.
34
&&
.FIRE WEATHER...
A POTENT COLD FRONT WILL SWEEP ACROSS NEW MEXICO TODAY USHERING IN
MUCH COOLER AIR...ESPECIALLY IN THE WEST. MOISTURE ALONG AND AHEAD
OF THE FRONT WILL COMBINE TO PRODUCE A ROUND OF SHOWERS AND
THUNDERSTORMS TODAY. SPOTTY WETTING RAINS WILL BE NOTED OVER THE
NORTHWEST THIS MORNING...WITH MORE WIDESPREAD WETTING RAINS OVER
THE FAR EASTERN PLAINS THIS AFTERNOON INTO THIS EVENING. WINDY
CONDITIONS WILL BE PRESENT OVER THE NORTHEAST WITH A WIND ADVISORY
FOR THE NORTHEAST HIGHLANDS LATE THIS MORNING THROUGH THE AFTERNOON.
THE MOISTURE AND COLD FRONT WILL CREATE LOWER TEMPERATURES AND
HIGHER RH VALUES TODAY...WHILE VENTILATION WILL BE MOSTLY
EXCELLENT...ALTHOUGH LOWERING IN THE WEST DURING THE DAY.
A TROUGH OF LOW PRESSURE WILL CROSS THE STATE TONIGHT WITH THE
CHILLIEST TEMPERATURES OF THE SEASON SO FAR FOR EARLY SATURDAY
MORNING. SOME LOWLAND LOCATIONS MAY SEE THEIR FIRST FREEZE...SUCH AS
FARMINGTON AND ESPANOLA. A FREEZE WATCH HAS BEEN ISSUED FOR THESE
LOCATIONS. SHOWERS WILL LINGER OVER THE SOUTHEAST AREA WELL INTO THE
NIGHT. A FEW SNOW SHOWERS MAY BE FOUND OVER THE HIGH PEAKS OF THE
NORTHERN MOUNTAINS THIS EVENING.
MUCH COOLER THAN NORMAL TEMPERATURES PROJECTED FOR SATURDAY AS THE
MID LEVEL DRY SLOT STAYS OVER PORTIONS OF THE FORECAST AREA. THE
VENTILATION WILL TAKE QUITE A HIT SATURDAY DUE TO POST COLD FRONTAL
INVERSION EFFECTS. LOTS OF POOR RATINGS ARE CURRENTLY SHOWING UP ON
SATURDAY FOR THE WEST. ANOTHER CHILLY NIGHT IS EXPECTED SATURDAY
NIGHT. WINDS WILL DIE DOWN AND ALLOW FOR EFFICIENT RADIATIONAL
COOLING. THE LOW LEVEL INVERSION WILL FORM QUITE NICELY ALONG THE
MIDSLOPES.
WEATHER MODELS CONTINUE TO SHOW A DRY ZONAL FLOW OVER THE FORECAST
AREA SUNDAY INTO THE MIDDLE OF NEXT WEEK. VENTILATION WILL GRADUALLY
IMPROVE AS MIXING HEIGHTS AND SURFACE TEMPERATURES SLOWLY INCREASE.
ONE EXCEPTION MAY BE THE NORTHEAST ON TUESDAY AS A WEAK TROUGH ALOFT
AND SURFACE COLD FRONT BRUSH THIS AREA.
MODELS DIVERGE GREATLY IN THE EXTENDED FORECAST. THE GFS BRINGS A
PROGRESSIVE TROUGH ACROSS NEW MEXICO FRIDAY...WHILE THE EUROPEAN HAS
A CLOSED LOW OVER THE FOUR CORNERS AREA SATURDAY...FINALLY LIFTING
THE TROUGH AWAY FROM NEW MEXICO SUNDAY. WHAT WE ARE MOST CONFIDENT
ON IS THURSDAY WILL BRING INCREASING WINDS AND FRIDAY WILL BE
COOLER. DURING THIS TIME THERE MAY BE SHOWER ACTIVITY OVER THE
NORTHERN MOUNTAINS AND NORTHEAST.
CHJ
&&
.AVIATION...
06Z TAF CYCLE
LARGE WESTERN WEATHER SYSTEM CENTERED ON GREAT SALT LAKE
CIRCULATING STRENGTHENING SOUTHWEST WINDS AND MOISTURE INTO
WESTERN NM...WITH TROPICAL PLUME OUT OF EASTERN MEXICO CROSSING
THE WEST TEXAS BIG BEND EN ROUTE FOR SOUTH CENTRAL NM. CIGS
EXCURSIONING TO MVFR WILL CROSS THE AZ AND CO BORDERS INTO
NORTHERN AND WESTERN NM THROUGH 12Z FRI MORNING...WITH SHOWER
COVERAGE AND LOWERING CIGS EXPANDING EASTWARD TO THE RIO GRANDE
VALLEY AND CENTRAL MT CHAIN THRU 15Z. CIGS LIFTING GRADUALLY FROM
21Z ONWARD...WITH STRONG TO SEVERE THUNDERSTORMS POSSIBLE OVER THE
EXTREME EASTERN PLAINS NEAR THE TX PANHANDLE FROM 22Z ONWARD
THROUGH 06Z FRIDAY EVENING. TAFS CARRYING SCT025 GROUPS SIGNALING
WINDOW OF GREATEST LIKELIHOOD FOR MVFR EXCURSION FOR THE NEXT 24 HRS.
SHY
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 66 32 66 34 / 20 0 0 0
DULCE........................... 59 26 63 28 / 50 0 0 0
CUBA............................ 62 29 65 30 / 30 0 0 0
GALLUP.......................... 64 24 65 29 / 20 0 0 0
EL MORRO........................ 61 26 63 30 / 30 0 0 0
GRANTS.......................... 65 26 66 30 / 30 0 0 0
QUEMADO......................... 66 27 68 34 / 20 0 0 0
GLENWOOD........................ 70 39 74 42 / 10 0 0 0
CHAMA........................... 58 25 59 28 / 60 10 0 0
LOS ALAMOS...................... 65 33 63 38 / 20 0 0 0
PECOS........................... 64 35 60 37 / 40 0 0 0
CERRO/QUESTA.................... 62 27 62 30 / 30 5 0 0
RED RIVER....................... 56 28 55 31 / 50 10 0 0
ANGEL FIRE...................... 61 22 60 25 / 50 5 0 0
TAOS............................ 65 25 63 29 / 30 5 0 0
MORA............................ 66 30 62 32 / 40 0 0 0
ESPANOLA........................ 72 33 68 36 / 20 0 0 0
SANTA FE........................ 67 34 64 38 / 30 0 0 0
SANTA FE AIRPORT................ 70 35 66 38 / 30 0 0 0
ALBUQUERQUE FOOTHILLS........... 72 42 70 45 / 20 0 0 0
ALBUQUERQUE HEIGHTS............. 75 45 70 48 / 10 0 0 0
ALBUQUERQUE VALLEY.............. 76 41 72 43 / 10 0 0 0
ALBUQUERQUE WEST MESA........... 74 42 70 44 / 10 0 0 0
LOS LUNAS....................... 76 39 72 42 / 10 0 0 0
RIO RANCHO...................... 73 41 72 44 / 10 0 0 0
SOCORRO......................... 81 45 74 47 / 10 0 0 0
SANDIA PARK/CEDAR CREST......... 69 37 68 40 / 30 5 0 0
TIJERAS......................... 70 38 68 40 / 20 5 0 0
MORIARTY/ESTANCIA............... 70 34 65 36 / 30 5 0 0
CLINES CORNERS.................. 68 39 64 39 / 30 5 0 0
GRAN QUIVIRA.................... 70 39 67 40 / 20 5 0 0
CARRIZOZO....................... 72 45 71 44 / 20 0 0 0
RUIDOSO......................... 66 46 64 44 / 20 5 0 0
CAPULIN......................... 72 33 64 36 / 20 5 0 0
RATON........................... 75 35 68 34 / 20 5 0 0
SPRINGER........................ 74 34 68 34 / 20 5 0 0
LAS VEGAS....................... 70 35 64 36 / 30 0 0 0
CLAYTON......................... 79 45 68 43 / 30 20 0 0
ROY............................. 75 41 64 40 / 20 5 0 0
CONCHAS......................... 80 48 69 46 / 20 5 0 0
SANTA ROSA...................... 79 45 69 45 / 20 5 0 0
TUCUMCARI....................... 82 50 73 47 / 30 10 0 0
CLOVIS.......................... 82 50 73 48 / 30 20 5 5
PORTALES........................ 83 51 73 49 / 30 20 5 5
FORT SUMNER..................... 83 50 74 50 / 30 10 0 0
ROSWELL......................... 87 56 78 52 / 30 10 5 5
PICACHO......................... 79 48 71 47 / 20 5 0 0
ELK............................. 74 47 68 46 / 20 5 5 5
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH SATURDAY MORNING FOR THE
FOLLOWING ZONES...NMZ501-517.
WIND ADVISORY FROM 11 AM THIS MORNING TO 6 PM MDT THIS EVENING FOR
THE FOLLOWING ZONES...NMZ515-527>529.
&&
$$
34
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
340 AM EDT FRI SEP 27 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE AS HIGH PRESSURE STRENGTHENS OVER THE
NORTH COUNTRY THROUGH SATURDAY. TEMPERATURES WILL GRADUALLY WARM
THROUGH THE WEEKEND. A WEAKENING COLD FRONT WILL THEN MOVE ACROSS
THE REGION SUNDAY NIGHT INTO MONDAY. THIS FRONT WILL PROVIDE A LOW
THREAT FOR RAIN SHOWERS. BEHIND THE FRONT...HIGH PRESSURE WILL
RETURN TO THE NORTHEAST.
&&
.NEAR TERM /UNTIL 11 AM THIS MORNING/...
AS OF 105 AM EDT FRIDAY...STRATUS DECK CONTINUES TO SPREAD ACROSS
THE AREA OVER MOST OF VT INTO WRN CPV THIS MORNING. THIS WILL
KEEP TEMPS MILDER THAN PREVIOUS NIGHTS. WITH HIGH PRESSURE
BUILDING OVER ERN ONTARIO AND WRN QUEBEC...INVERSION WILL BE
REINFORCED...KEEPING THE STRATUS DECK OVER THE ERN HALF TO TWO-
THIRDS OF THE CWA INTO THE LATE MORNING HRS.
PREVIOUS DISCUSSION...INFRARED SATELLITE CONTINUES TO REVEAL
PERSISTENT OVERCAST LOW CLOUD DECK ACROSS NORTHERN VERMONT AND
INTO THE EASTERN EDGE OF THE NORTHERN ADIRONDACKS...BEING
MAINTAINED BY NORTHEASTERLY LOW-LEVEL MOISTURE ADVECTION FROM THE
NORTH ATLANTIC. RIDGE AXIS ALOFT WILL ALSO BE APPROACHING THE
NORTH COUNTRY LATER TONIGHT AS WELL...WHICH WILL ALSO AID IN
MAINTAINING LOW CLOUDS. SHORT- RANGE GUIDANCE CONTINUES TO
RESOLVE THE LINGERING OVERCAST POORLY AND OF THE GUIDANCE
SUITE...THE RAP MODEL RH IS HANDLING THE SITUATION THE BEST. I
HAVE OPTED FOR A MORE PESSIMISTIC SKY COVER FORECAST THROUGH THE
OVERNIGHT...KEEPING OVERCAST AROUND ACROSS NORTHERN VERMONT AND
THE NORTHEAST KINGDOM WITH THE IDEA THAT LOW LEVEL MOISTURE WILL
PROVE DIFFICULT TO FULLY SCOUR OUT. I`VE ALSO RAISED LOW
TEMPERATURES UP A COUPLE OF IN THESE AREAS TO ACCOUNT FOR THE
INCREASE IN CLOUDS...AND REMOVED MENTION OF FOG IN THE NORTHERN
CT RIVER VALLEY GIVEN LOWER PROSPECTS FOR SIGNIFICANT RADIATIONAL
COOLING THERE. REST OF THE FORECAST REMAINS LARGELY UNCHANGED.
LOWS GENERALLY IN THE MID/UPPER 30S FOR THE NORTHERN ADIRONDACKS
TO THE 40S ELSEWHERE (UPPER 40S MOST LIKELY ADJACENT TO LAKE
CHAMPLAIN).
&&
.SHORT TERM /11 AM THIS MORNING THROUGH SUNDAY/...
AS OF 301 PM EDT THURSDAY...SURFACE RIDGE OF HIGH PRESSURE BUILDS
OVERHEAD ON FRIDAY. LOW LEVEL MOISTURE DIMINISHES THROUGHOUT THE
DAY...WHICH SHOULD RESULT IN A DECREASE IN CLOUDS. WINDS WILL BE
LIGHT WITH VALLEY HIGHS IN THE UPPER 60S AND LOWER 70S.
MOSTLY CLEAR SKIES CONTINUE FRIDAY NIGHT THROUGH SATURDAY NIGHT
AS A MASSIVE RIDGE ALOFT CRESTS OVER THE AREA AND SURFACE HIGH
PRESSURE REMAINS OVER THE REGION. THE RESULT WILL BE MAINLY CLEAR
SKIES AND LIGHT WINDS WITH A RATHER LARGE DIURNAL RANGE IN TEMPS.
MIN TEMPS FRIDAY FRIDAY NIGHT WILL RANGE FROM THE MID 30S TO THE
MID 40S...WITH HIGHS SATURDAY IN THE LOWER TO MID 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 324 AM EDT FRIDAY...NO CHANGES TO PREVIOUS FORECAST IN THE
EXTENDED PERIOD WITH HIGH PRESSURE THE DOMINANT FEATURE. DRY AND
MILD CONDITIONS THROUGH THE WEEK.
ONLY WEATHER FEATURES TO SPEAK OF ARE AT THE BEGINNING OF THIS
EXTENDED PERIOD...AS A COLD FRONT APPROACHING FROM THE WEST STALLS
OUT OVER WESTERN NY AS A COASTAL STORM MOVES UP THE EAST COAST.
RIDGE OF HIGH PRESSURE BEING SQUEEZED BETWEEN THE TWO OVER NEW
ENGLAND IN EFFECT BLOCKS BOTH FROM MOVING INTO THE FORECAST AREA.
THE FRONT REMAINS TO THE WEST AND WEAKENS...WHILE THE COASTAL
STORM MOVES NORTHEAST THROUGH THE GULF OF MAINE. THE GFS IS THE
FARTHEST WEST AND BREAKS OUT SOME LIGHT RAIN IN SOUTHERN NEW
ENGLAND INTO SOUTHERN VERMONT. ONLY WARRANTS SLIGHT CHANCE POPS
LATE MONDAY GIVEN UNCERTAINTIES AND CENTER OF LOW FORECAST TO MOVE
OVER OR JUST EAST OF THE BENCHMARK 40N/70W.
FROM TUESDAY ONWARD THEN HIGH PRESSURE BUILDS AT SURFACE AND
ALOFT. CENTER OF SURFACE RIDGE NOSES UP ATLANTIC COAST INTO
CENTRAL PA...AND SURFACE FLOW AROUND THE RIDGE BRINGS LIGHT
NORTHERLY FLOW TO THE REGION. DESPITE NORTHERLY FLOW TRAJECTORIES
ACTUALLY ORIGINATE OVER THE MIDWEST...WITH CONTINUED MILD
TEMPERATURES. SKIES TO TREND TOWARDS PARTLY CLOUDY/PARTLY SUNNY
GIVEN THE ABSENCE OF A STRONG MOISTURE FEED OR SYNOPTIC SCALE LIFT
TO GENERATE MORE CLOUDINESS.
LITTLE CHANGE IN TEMPS DAY TO DAY, WITH LOWS IN THE 40S AND LOW
50S, AND HIGHS IN THE UPPER 60S TO LOW 70S.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...MVFR CIGS AND VFR VIS WITH SCT IFR CIGS AND
VIS IN PERSISTENT CLOUD COVER THROUGH THE REST OF THE NIGHT FOR
NORTHERN HALF OF VT AND NORTHEAST NY. FOLLOWED PREVIOUS FORECAST
AND ADDED MVFR CIGS/VIS KSLK/KMPV IN LIGHT FOG/MIST FORMATION.
KMSS HAS BEEN CLEAR ALL EVENING AND NOW HAS FORMED LIFR CIG/VIS IN
RADIATION FOG. EXPECT KMSS TO REMAIN LIFR ALL NIGHT AND IMPROVE
AFTER SUNUP. DURIN DAY TODAY CIGS TO BECOME SCATTERED WITH VFR FOR
REST OF DAY AND LIGHT N WINDS.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...MAINLY VFR WITH HIGH
PRESSURE BUILDING IN. BR/FG POSSIBLE 06-14Z EACH DAY ESPECIALLY
SLK MPV.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RJS
NEAR TERM...RJS/KGM/LOCONTO
SHORT TERM...RJS
LONG TERM...HANSON
AVIATION...HANSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
122 AM EDT FRI SEP 27 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE AS HIGH PRESSURE STRENGTHENS OVER THE
NORTH COUNTRY THROUGH SATURDAY. TEMPERATURES WILL GRADUALLY WARM
THROUGH THE WEEKEND. A WEAKENING COLD FRONT WILL THEN MOVE ACROSS
THE REGION SUNDAY NIGHT INTO MONDAY. THIS FRONT WILL PROVIDE A LOW
THREAT FOR RAIN SHOWERS. BEHIND THE FRONT...HIGH PRESSURE WILL
RETURN TO THE NORTHEAST.
&&
.NEAR TERM /UNTIL 11 AM THIS MORNING/...
AS OF 105 AM EDT FRIDAY...STRATUS DECK CONTINUES TO SPREAD ACROSS
THE AREA OVER MOST OF VT INTO WRN CPV THIS MORNING. THIS WILL
KEEP TEMPS MILDER THAN PREVIOUS NIGHTS. WITH HIGH PRESSURE
BUILDING OVER ERN ONTARIO AND WRN QUEBEC...INVERSION WILL BE
REINFORCED...KEEPING THE STRATUS DECK OVER THE ERN HALF TO TWO-
THIRDS OF THE CWA INTO THE LATE MORNING HRS.
PREVIOUS DISCUSSION...INFRARED SATELLITE CONTINUES TO REVEAL
PERSISTENT OVERCAST LOW CLOUD DECK ACROSS NORTHERN VERMONT AND
INTO THE EASTERN EDGE OF THE NORTHERN ADIRONDACKS...BEING
MAINTAINED BY NORTHEASTERLY LOW-LEVEL MOISTURE ADVECTION FROM THE
NORTH ATLANTIC. RIDGE AXIS ALOFT WILL ALSO BE APPROACHING THE
NORTH COUNTRY LATER TONIGHT AS WELL...WHICH WILL ALSO AID IN
MAINTAINING LOW CLOUDS. SHORT- RANGE GUIDANCE CONTINUES TO
RESOLVE THE LINGERING OVERCAST POORLY AND OF THE GUIDANCE
SUITE...THE RAP MODEL RH IS HANDLING THE SITUATION THE BEST. I
HAVE OPTED FOR A MORE PESSIMISTIC SKY COVER FORECAST THROUGH THE
OVERNIGHT...KEEPING OVERCAST AROUND ACROSS NORTHERN VERMONT AND
THE NORTHEAST KINGDOM WITH THE IDEA THAT LOW LEVEL MOISTURE WILL
PROVE DIFFICULT TO FULLY SCOUR OUT. I`VE ALSO RAISED LOW
TEMPERATURES UP A COUPLE OF IN THESE AREAS TO ACCOUNT FOR THE
INCREASE IN CLOUDS...AND REMOVED MENTION OF FOG IN THE NORTHERN
CT RIVER VALLEY GIVEN LOWER PROSPECTS FOR SIGNIFICANT RADIATIONAL
COOLING THERE. REST OF THE FORECAST REMAINS LARGELY UNCHANGED.
LOWS GENERALLY IN THE MID/UPPER 30S FOR THE NORTHERN ADIRONDACKS
TO THE 40S ELSEWHERE (UPPER 40S MOST LIKELY ADJACENT TO LAKE
CHAMPLAIN).
&&
.SHORT TERM /11 AM THIS MORNING THROUGH SATURDAY NIGHT/...
AS OF 301 PM EDT THURSDAY...SURFACE RIDGE OF HIGH PRESSURE BUILDS
OVERHEAD ON FRIDAY. LOW LEVEL MOISTURE DIMINISHES THROUGHOUT THE
DAY...WHICH SHOULD RESULT IN A DECREASE IN CLOUDS. WINDS WILL BE
LIGHT WITH VALLEY HIGHS IN THE UPPER 60S AND LOWER 70S.
MOSTLY CLEAR SKIES CONTINUE FRIDAY NIGHT THROUGH SATURDAY NIGHT
AS A MASSIVE RIDGE ALOFT CRESTS OVER THE AREA AND SURFACE HIGH
PRESSURE REMAINS OVER THE REGION. THE RESULT WILL BE MAINLY CLEAR
SKIES AND LIGHT WINDS WITH A RATHER LARGE DIURNAL RANGE IN TEMPS.
MIN TEMPS FRIDAY FRIDAY NIGHT WILL RANGE FROM THE MID 30S TO THE
MID 40S...WITH HIGHS SATURDAY IN THE LOWER TO MID 70S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 309 PM EDT THURSDAY...PLEASANT FALL WEATHER WITH MAINLY
DRY/MILD CONDITIONS AND LITTLE CHANGE FROM DAY TO DAY IS EXPECTED
FROM THIS WEEKEND AND INTO NEXT WEEK.
HIGH PRESSURE WILL STILL MAINLY BE IN CONTROL ON SUNDAY...BUT THE
RIDGE WILL BE BREAKING DOWN AS WEAKENING UPPER TROUGH AND COLD FRONT
APPROACH FROM THE WEST AND LOW PRESSURE SYSTEM (POSSIBLY
SUBTROPICAL IN NATURE) DEVELOPS WELL OFFSHORE OF THE SOUTHEAST UNITED
STATES COAST. THAT BEING SAID MOSTLY SUNNY SKIES STILL EXPECTED TO
PREVAIL FOR MUCH OF THE DAY. COLD FRONT AND UPPER TROUGH WASH OUT
OVER THE REGION ON SUNDAY NIGHT AND MONDAY WITH MOISTURE/ENERGY
BEING TRANSFERRED OFFSHORE AS OCEAN LOW STRENGTHENS. THIS WILL
LEAD TO GENERALLY PARTLY CLOUDY SKIES WITH PERHAPS A FEW ISOLATED
RAIN SHOWERS.
SYSTEM WILL PULL AWAY MONDAY NIGHT AND TUESDAY WITH AN UPPER RIDGE
BUILDING INTO THE REGION. LITTLE TO NO CHANGE IN OVERALL AIR MASS IS
ANTICIPATED SO PARTLY CLOUDY SKIES AND MILD TEMPERATURES WILL
CONTINUE. NEXT SYSTEM WILL TRY TO WORK TOWARDS THE REGION WEDNESDAY
INTO THURSDAY BUT BUILDING UPPER RIDGE SHOULD ACT TO KEEP MOST OF
THE ENERGY/MOISTURE NORTH ACROSS SOUTHERN CANADA. STILL WITH A WEAK
FRONTAL SYSTEM CROSSING THE AREA...MAY AGAIN SEE A FEW ISOLATED RAIN
SHOWERS. BEHIND THE SYSTEM RIDGE CONTINUES TO BUILD SO RELATIVELY
UNEVENTFUL WEATHER EXPECTED TO CONTINUE THROUGH THE END OF NEXT WEEK.
TEMPERATURES WILL BE SIMILAR AND RELATIVELY MILD EACH DAY...WITH
HIGHS GENERALLY 68-73F EACH DAY SUNDAY-THURSDAY AND LOWS IN THE 40S
TO LOW 50S.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...MVFR CIGS AND VFR VIS WITH SCT IFR CIGS AND
VIS IN PERSISTENT CLOUD COVER THROUGH THE REST OF THE NIGHT FOR
NORTHERN HALF OF VT AND NORTHEAST NY. FOLLOWED PREVIOUS FORECAST
AND ADDED MVFR CIGS/VIS KSLK/KMPV IN LIGHT FOG/MIST FORMATION.
KMSS HAS BEEN CLEAR ALL EVENING AND NOW HAS FORMED LIFR CIG/VIS IN
RADIATION FOG. EXPECT KMSS TO REMAIN LIFR ALL NIGHT AND IMPROVE
AFTER SUNUP. DURIN DAY TODAY CIGS TO BECOME SCATTERED WITH VFR FOR
REST OF DAY AND LIGHT N WINDS.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...MAINLY VFR WITH HIGH
PRESSURE BUILDING IN. BR/FG POSSIBLE 06-14Z EACH DAY ESPECIALLY
SLK MPV.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RJS
NEAR TERM...RJS/KGM/LOCONTO
SHORT TERM...RJS
LONG TERM...MUCCILLI
AVIATION...HANSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
106 AM EDT FRI SEP 27 2013
.SYNOPSIS...
DRY WEATHER WILL CONTINUE AS HIGH PRESSURE STRENGTHENS OVER THE
NORTH COUNTRY THROUGH SATURDAY. TEMPERATURES WILL GRADUALLY WARM
THROUGH THE WEEKEND. A WEAKENING COLD FRONT WILL THEN MOVE ACROSS
THE REGION SUNDAY NIGHT INTO MONDAY. THIS FRONT WILL PROVIDE A LOW
THREAT FOR RAIN SHOWERS. BEHIND THE FRONT...HIGH PRESSURE WILL
RETURN TO THE NORTHEAST.
&&
.NEAR TERM /UNTIL 11 AM THIS MORNING/...
AS OF 105 AM EDT FRIDAY...STRATUS DECK CONTINUES TO SPREAD ACROSS
THE AREA OVER MOST OF VT INTO WRN CPV THIS MORNING. THIS WILL
KEEP TEMPS MILDER THAN PREVIOUS NIGHTS. WITH HIGH PRESSURE
BUILDING OVER ERN ONTARIO AND WRN QUEBEC...INVERSION WILL BE
REINFORCED...KEEPING THE STRATUS DECK OVER THE ERN HALF TO TWO-
THIRDS OF THE CWA INTO THE LATE MORNING HRS.
PREVIOUS DISCUSSION...INFRARED SATELLITE CONTINUES TO REVEAL
PERSISTENT OVERCAST LOW CLOUD DECK ACROSS NORTHERN VERMONT AND
INTO THE EASTERN EDGE OF THE NORTHERN ADIRONDACKS...BEING
MAINTAINED BY NORTHEASTERLY LOW-LEVEL MOISTURE ADVECTION FROM THE
NORTH ATLANTIC. RIDGE AXIS ALOFT WILL ALSO BE APPROACHING THE
NORTH COUNTRY LATER TONIGHT AS WELL...WHICH WILL ALSO AID IN
MAINTAINING LOW CLOUDS. SHORT- RANGE GUIDANCE CONTINUES TO
RESOLVE THE LINGERING OVERCAST POORLY AND OF THE GUIDANCE
SUITE...THE RAP MODEL RH IS HANDLING THE SITUATION THE BEST. I
HAVE OPTED FOR A MORE PESSIMISTIC SKY COVER FORECAST THROUGH THE
OVERNIGHT...KEEPING OVERCAST AROUND ACROSS NORTHERN VERMONT AND
THE NORTHEAST KINGDOM WITH THE IDEA THAT LOW LEVEL MOISTURE WILL
PROVE DIFFICULT TO FULLY SCOUR OUT. I`VE ALSO RAISED LOW
TEMPERATURES UP A COUPLE OF IN THESE AREAS TO ACCOUNT FOR THE
INCREASE IN CLOUDS...AND REMOVED MENTION OF FOG IN THE NORTHERN
CT RIVER VALLEY GIVEN LOWER PROSPECTS FOR SIGNIFICANT RADIATIONAL
COOLING THERE. REST OF THE FORECAST REMAINS LARGELY UNCHANGED.
LOWS GENERALLY IN THE MID/UPPER 30S FOR THE NORTHERN ADIRONDACKS
TO THE 40S ELSEWHERE (UPPER 40S MOST LIKELY ADJACENT TO LAKE
CHAMPLAIN).
&&
.SHORT TERM /11 AM THIS MORNING THROUGH SATURDAY NIGHT/...
AS OF 301 PM EDT THURSDAY...SURFACE RIDGE OF HIGH PRESSURE BUILDS
OVERHEAD ON FRIDAY. LOW LEVEL MOISTURE DIMINISHES THROUGHOUT THE
DAY...WHICH SHOULD RESULT IN A DECREASE IN CLOUDS. WINDS WILL BE
LIGHT WITH VALLEY HIGHS IN THE UPPER 60S AND LOWER 70S.
MOSTLY CLEAR SKIES CONTINUE FRIDAY NIGHT THROUGH SATURDAY NIGHT
AS A MASSIVE RIDGE ALOFT CRESTS OVER THE AREA AND SURFACE HIGH
PRESSURE REMAINS OVER THE REGION. THE RESULT WILL BE MAINLY CLEAR
SKIES AND LIGHT WINDS WITH A RATHER LARGE DIURNAL RANGE IN TEMPS.
MIN TEMPS FRIDAY FRIDAY NIGHT WILL RANGE FROM THE MID 30S TO THE
MID 40S...WITH HIGHS SATURDAY IN THE LOWER TO MID 70S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 309 PM EDT THURSDAY...PLEASANT FALL WEATHER WITH MAINLY
DRY/MILD CONDITIONS AND LITTLE CHANGE FROM DAY TO DAY IS EXPECTED
FROM THIS WEEKEND AND INTO NEXT WEEK.
HIGH PRESSURE WILL STILL MAINLY BE IN CONTROL ON SUNDAY...BUT THE
RIDGE WILL BE BREAKING DOWN AS WEAKENING UPPER TROUGH AND COLD FRONT
APPROACH FROM THE WEST AND LOW PRESSURE SYSTEM (POSSIBLY
SUBTROPICAL IN NATURE) DEVELOPS WELL OFFSHORE OF THE SOUTHEAST UNITED
STATES COAST. THAT BEING SAID MOSTLY SUNNY SKIES STILL EXPECTED TO
PREVAIL FOR MUCH OF THE DAY. COLD FRONT AND UPPER TROUGH WASH OUT
OVER THE REGION ON SUNDAY NIGHT AND MONDAY WITH MOISTURE/ENERGY
BEING TRANSFERRED OFFSHORE AS OCEAN LOW STRENGTHENS. THIS WILL
LEAD TO GENERALLY PARTLY CLOUDY SKIES WITH PERHAPS A FEW ISOLATED
RAIN SHOWERS.
SYSTEM WILL PULL AWAY MONDAY NIGHT AND TUESDAY WITH AN UPPER RIDGE
BUILDING INTO THE REGION. LITTLE TO NO CHANGE IN OVERALL AIR MASS IS
ANTICIPATED SO PARTLY CLOUDY SKIES AND MILD TEMPERATURES WILL
CONTINUE. NEXT SYSTEM WILL TRY TO WORK TOWARDS THE REGION WEDNESDAY
INTO THURSDAY BUT BUILDING UPPER RIDGE SHOULD ACT TO KEEP MOST OF
THE ENERGY/MOISTURE NORTH ACROSS SOUTHERN CANADA. STILL WITH A WEAK
FRONTAL SYSTEM CROSSING THE AREA...MAY AGAIN SEE A FEW ISOLATED RAIN
SHOWERS. BEHIND THE SYSTEM RIDGE CONTINUES TO BUILD SO RELATIVELY
UNEVENTFUL WEATHER EXPECTED TO CONTINUE THROUGH THE END OF NEXT WEEK.
TEMPERATURES WILL BE SIMILAR AND RELATIVELY MILD EACH DAY...WITH
HIGHS GENERALLY 68-73F EACH DAY SUNDAY-THURSDAY AND LOWS IN THE 40S
TO LOW 50S.
&&
.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
THROUGH 00Z SATURDAY...PERSISTENT CLOUD COVER OVER NORTHEAST NEW YORK AND
MOST OF VERMONT WILL LEAD TO VFR/MVFR CEILINGS THROUGH ABOUT 12Z BEFORE
CONDITIONS BECOME VFR WITH VERY LITTLE CLOUD COVER FOR THE REMAINDER
OF THE PERIOD. IN ADDITION...LOOKING FOR SOME FOG TO DEVELOP AT KSLK
AND KMPV WITH PERIODS OF LIFR AND VLIFR BETWEEN 07Z AND 12Z. ELSEWHERE
THERE MAY BE BRIEF PERIODS OF FOG REDUCING VISIBILITIES INTO THE IFR
CATEGORY BETWEEN 07Z AND 12Z AS WELL. WINDS WILL GENERALLY HAVE A NORTHERLY
COMPONENT THROUGH THE PERIOD...BUT SPEEDS WILL BE LESS THAN 10 KNOTS.
OUTLOOK 00Z SATURDAY THROUGH TUESDAY...MAINLY VFR WITH HIGH PRESSURE
BUILDING IN. BR/FG POSSIBLE 06-14Z EACH DAY ESPECIALLY SLK MPV.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RJS
NEAR TERM...RJS/KGM/LOCONTO
SHORT TERM...RJS
LONG TERM...MUCCILLI
AVIATION...EVENSON/MUCCILLI
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
314 PM CDT FRI SEP 27 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 314 PM CDT FRI SEP 27 2013
THE CHALLENGE WILL BE RAIN CHANCES AND AMOUNTS. EVERYTHING YOU
HAVE READ IN THE PAST COUPLE DAYS (SEE PREVIOUS FORECAST
DISCUSSIONS) IS STILL VALID AND THE FORECAST IS UNFOLDING
ACCORDING TO PLAN. THE 12Z NAM IS A BIT FURTHER WEST WITH THE MAIN
BAND OF RAIN TONIGHT...AND THE RAP IS ALSO WEST. WILL CONTINUE TO
FOLLOW THE MOST CONSISTENT ECMWF (WHICH MOSTLY IS IN AGREEMENT
WITH THE GFS AND GEM). THERE WILL BE AREAS OF SHOWERS INTO THIS
EVENING BEFORE THE MORE WIDESPREAD AND MODERATE RAINFALL MOVES
INTO THE REGION (MOSTLY AFTER MIDNIGHT). STILL LOOKING LIKE AROUND
AN INCH OF WIDESPREAD RAINFALL...WITH ISOLATED HIGHER AMOUNTS
POSSIBLE. AS THE UPPER WAVE PROPAGATES NORTHEAST ON
SATURDAY...RAINFALL WILL END FROM WEST TO EAST ACROSS THE REGION.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 314 PM CDT FRI SEP 27 2013
SUNDAY-MONDAY...FAST ZONAL UPPER FLOW ALONG WITH LOW LEVEL
SOUTHERLY FLOW WILL DEVELOP. THIS SHOULD LEAD TO DRY WEATHER
ALONG WITH TEMPERATURES ABOVE NORMAL. 12Z MODELS DO NOT SHOW ANY
STRONGER UPPER WAVES DURING THIS PERIOD.
MONDAY NIGHT-FRIDAY...ZONAL FLOW TO START THE EXTENDED FORECAST
PERIOD ON TUESDAY...ECMWF HINTS AT A SHORT WAVE PASSING THROUGH
THE FLOW PAINTING SOME PCPN. BUT THIS SEEMS NEW AND IS CONTRARY TO
OTHER GUIDANCE SO WILL KEEP TUESDAY DRY. 850 MB TEMPS IN THE 10 TO
15C RANGE POINT TO A WARM START TO THE WEEK WITH SOUTHERN SPOTS
MAXING OUT IN THE 70S.
ECMWF ALSO APPEARS TO BE PLACING PCPN A LITTLE TOO FAR NORTH
FOR WEDNESDAY WITH HIGH PRESSURE OVER THE REGION AND HAVE OPTED TO
CONTINUE OUR DRY FCST THROUGH MIDWEEK. SURFACE TROUGH/FRONT SHOULD
MAKE ITS WAY TO THE CWA BY THURSDAY HOWEVER...WITH INDICATIONS OF
CAPE SUITABLE FOR SOME THUNDER...TRANSITIONING TO RAIN SHOWERS BY
FRIDAY AS THE SYSTEM MOVES WELL EAST. THE MILD TEMPS OF THE FIRST
HALF OF THE WEEK WILL BE GONE BY FRIDAY...AS COLDER IS DRAWN DOWN
FROM CANADA LEE OF THE TROUGH...LEAVING THE MERCURY IN THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1240 PM CDT FRI SEP 27 2013
ABUNDANT MOISTURE TRANSLATING TO MAINLY MVFR CIGS AT OUR TAF
LOCATIONS THIS AFTERNOON...THAT WILL CONTINUE INTO THIS EVENING.
TROUGH OVER THE SPINE OF THE REGION WILL MOVE QUITE SLOWLY THE NEXT
18 HOURS KEEPING WIND DIRECTION ESSENTIALLY UNCHANGED FOR EACH SITE
DURING THIS PERIOD. PCPN WILL BE MORE SHOWERY IN NATURE THROUGH
EARLY EVENING THEN CHANGE (WITH CONCURRENT CIG LOWERING TO IFR) TO
MORE OF A STEADY LIGHT (AND BRIEFLY MODERATE) RAIN LATE
EVENING...OVERNIGHT THROUGH MID DAY SATURDAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...TG
LONG TERM...WJB/TG
AVIATION...WJB
AREA FORECAST DISCUSSION
NWS NORMAN OK
1224 PM CDT FRI SEP 27 2013
.DISCUSSION...
REFER TO THE 18Z AVIATION FORECAST BELOW...
&&
.AVIATION...
CONDITIONS OVER THE NEXT 24 HOURS WILL HINGE LARGELY ON A COLD
FRONT SET TO MOVE ACROSS ALL TERMINALS BY 18Z TOMORROW. THIS FRONT
WILL FIRST IMPACT NW TAF SITES IN THE 00Z TO 04Z TIMEFRAME...THEN
MOVE SOUTHEAST TO KOKC/KOUN BY AROUND 15Z FRIDAY. SHRA/TSRA WITH
MVFR/IFR CIGS/VSBYS WILL OCCUR...ESPECIALLY NEAR HEAVIER STORMS. A
STOUT WIND SHIFT WILL ALSO ACCOMPANY THE FRONT...SHIFTING FROM SW
TO NW AND EVENTUALLY NE. VFR CONDITIONS WILL GRADUALLY RETURN TO
NRN/WRN TAF SITES BY TOMORROW AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 1033 AM CDT FRI SEP 27 2013/
DISCUSSION...
CLOUDS WILL INCREASE OVER MOST OF THE REGION TODAY...AS MOISTURE
RETURNS AT ALL LEVELS. HAVE MADE MINOR CHANGES TO DEW
POINT/HUMIDITY FORECASTS THROUGH THIS EVENING. SHORT-RANGE
GUIDANCE SUGGESTS THAT SOME OF OUR AFTERNOON HIGH TEMPERATURES
MIGHT BE A DEGREE OR TWO LOW...BUT WITH THE EXPECTED INCREASE IN
CLOUD COVER...IT SEEMS PREMATURE TO MAKE UPWARD CHANGES AT THIS
POINT. WILL REEVALUATE IN EARLY AFTERNOON.
RAIN CHANCES WILL REMAIN VERY LOW THROUGH ABOUT 00Z...THEN
INCREASE RAPIDLY ALONG OUR WESTERN BORDER. THE LATEST HRRR MODEL
AND LARGER-SCALE MODELS ALL AGREE ON THIS POINT.
PREV DISCUSSION... /ISSUED 630 AM CDT FRI SEP 27 2013/
AVIATION...
27/12Z TAFS...VFR AND WINDY CONDITIONS EXPECTED A MAJORITY OF
FORECAST PERIOD. MVFR TO OCCASIONAL IFR CONDITIONS POSSIBLE THIS
EVENING AND OVERNIGHT AS WIDESPREAD RAIN WITH EMBEDDED TSRA
EXPECTED NEAR/BEHIND COLD FRONT. WE WILL KEEP TIMING CLOSE TO
PREVIOUS FORECAST. MOST OF THE RAIN WILL BE CONFINED OVER
NORTHWEST AND WEST-CENTRAL OKLAHOMA TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 69 78 57 79 / 40 80 40 0
HOBART OK 68 79 55 79 / 80 70 20 0
WICHITA FALLS TX 71 81 61 80 / 30 80 50 10
GAGE OK 60 77 47 79 / 80 30 10 0
PONCA CITY OK 67 76 53 79 / 60 80 10 0
DURANT OK 70 86 65 83 / 10 70 80 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
84/23
AREA FORECAST DISCUSSION
NWS NORMAN OK
1033 AM CDT FRI SEP 27 2013
.DISCUSSION...
CLOUDS WILL INCREASE OVER MOST OF THE REGION TODAY...AS MOISTURE
RETURNS AT ALL LEVELS. HAVE MADE MINOR CHANGES TO DEW
POINT/HUMIDITY FORECASTS THROUGH THIS EVENING. SHORT-RANGE
GUIDANCE SUGGESTS THAT SOME OF OUR AFTERNOON HIGH TEMPERATURES
MIGHT BE A DEGREE OR TWO LOW...BUT WITH THE EXPECTED INCREASE IN
CLOUD COVER...IT SEEMS PREMATURE TO MAKE UPWARD CHANGES AT THIS
POINT. WILL REEVALUATE IN EARLY AFTERNOON.
RAIN CHANCES WILL REMAIN VERY LOW THROUGH ABOUT 00Z...THEN
INCREASE RAPIDLY ALONG OUR WESTERN BORDER. THE LATEST HRRR MODEL
AND LARGER-SCALE MODELS ALL AGREE ON THIS POINT.
&&
.PREV DISCUSSION... /ISSUED 630 AM CDT FRI SEP 27 2013/
AVIATION...
27/12Z TAFS...VFR AND WINDY CONDITIONS EXPECTED A MAJORITY OF
FORECAST PERIOD. MVFR TO OCCASIONAL IFR CONDITIONS POSSIBLE THIS
EVENING AND OVERNIGHT AS WIDESPREAD RAIN WITH EMBEDDED TSRA
EXPECTED NEAR/BEHIND COLD FRONT. WE WILL KEEP TIMING CLOSE TO
PREVIOUS FORECAST. MOST OF THE RAIN WILL BE CONFINED OVER
NORTHWEST AND WEST-CENTRAL OKLAHOMA TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 89 69 78 57 / 0 40 80 40
HOBART OK 90 68 79 55 / 0 80 70 20
WICHITA FALLS TX 93 71 81 61 / 0 30 80 50
GAGE OK 86 60 77 47 / 10 80 30 10
PONCA CITY OK 89 67 76 53 / 0 60 80 10
DURANT OK 92 70 86 65 / 0 10 70 80
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
23/84
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
914 PM CDT SAT SEP 28 2013
.DISCUSSION...02Z SURFACE ANALYSIS PLACES A COLD FRONT FROM
MILWAUKEE TO SAINT LOUIS...AND WESTERN ARKANSAS. KLZK WSR-88D
RADAR TRENDS OVER THE PAST COUPLE OF HOURS HAVE SHOWN CONSIDERABLE
WEAKENING OF THE CONVECTIVE RAIN SHOWERS AND PERHAPS AN EMBEDDED
THUNDERSTORM OR TWO OVER CENTRAL ARKANSAS AS THEY BEGIN TO
APPROACH EAST AND NORTHEAST ARKANSAS LATE THIS EVENING AND
ENCOUNTER A DRIER AND MORE STABLE AIRMASS OVER THE MID SOUTH. 00Z
UPPER AIR SOUNDINGS AT JACKSON MS AND NASHVILLE INDICATE A
SUBSTANTIAL 800-700 MB CAPPING INVERSION PRESENT ACROSS THE
REMAINDER OF THE LOWER MISSISSIPPI VALLEY. LATEST 3KM HRRR AND 00Z
WRF INDICATE MOST IF NOT ALL OF THE RAIN SHOWERS WILL STRUGGLE TO
GET PAST THE MISSISSIPPI RIVER BEFORE 12Z. /7 AM CDT/ WILL MAKE
FURTHER ADJUSTMENTS TO OVERNIGHT RAIN CHANCES TO REDUCE THUNDER
MENTION AND KEEP MOST OF THE RAIN CHANCES ALONG/WEST OF THE
MISSISSIPPI RIVER. WILL MAKE ANY OTHER ADJUSTMENTS TO GRIDS AS
NEEDED TO ACCOUNT FOR LATEST TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 638 PM CDT SAT SEP 28 2013/
DISCUSSION...23Z SURFACE ANALYSIS PLACES A COLD FRONT FROM
WISCONSIN BACK THROUGH EAST CENTRAL MISSOURI AND NORTHWEST
ARKANSAS/EASTERN OKLAHOMA. LATEST KLZK/REGIONAL WSR-88D RADAR
TRENDS SHOW THE LEADING EDGE OF RAIN SHOWERS AND PERHAPS AN
EMBEDDED ISOLATED THUNDERSTORM OR TWO LOCATED JUST WEST OF LITTLE
ROCK AND HOT SPRINGS. LATEST SHORT TERM TRENDS INCLUDING THE 3KM
HRRR INDICATE SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL ENTER
PORTIONS OF EAST/NORTHEAST ARKANSAS AND THE MISSOURI BOOTHEEL MUCH
SOONER THAN PREVIOUS FORECAST. THUS...HAVE INCREASED RAIN CHANCES
WEST OF THE MISSISSIPPI RIVER THIS EVENING...ESPECIALLY AFTER 3Z.
/10 PM CDT/ OTHERWISE...REMAINDER OF FORECAST REMAINS IN GOOD
SHAPE AT THIS TIME.
UPDATED GRIDS ALREADY SENT.
CJC
PREV DISCUSSION... /ISSUED 613 PM CDT SAT SEP 28 2013/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 328 PM CDT SAT SEP 28 2013/
DISCUSSION...
A COLD FRONT CURRENTLY STRETCHES FROM NEAR KIRKSVILLE MISSOURI TO
NEAR FORT SMITH ARKANSAS. A BAND OF SHOWERS HAS FORMED ALONG THE
FRONT FROM SOUTHWEST MISSOURI TO EASTERN OKLAHOMA INTO NORTHWEST
ARKANSAS. THIS FRONT WILL MOVE INTO THE MIDSOUTH LATE TONIGHT.
CURRENTLY ACROSS THE MIDSOUTH...TEMPERATURES HAVE RISEN INTO THE
80S THANKS TO AN UPPER RIDGE THAT HAS BEEN POSITIONED ALONG THE
GULF COAST FOR THE LAST COUPLE OF DAYS. THE RIDGE WILL RETREAT
EASTWARD THIS EVENING. EXPECT BAND OF SHOWERS TO MOVE INTO
RANDOLPH/LAWRENCE COUNTIES BETWEEN 9 PM AND MIDNIGHT. THE BAND OF
SHOWERS WILL SLOWLY PUSH SOUTH AND EAST AFTER MIDNIGHT. EXPECT
BAND TO BE ROUGHLY LOCATED ALONG THE MISSISSIPPI RIVER BETWEEN
6 AM-8 AM. CAN/T RULE OUT A FEW EMBEDDED THUNDERSTORMS DEVELOPING
IN THE BAND SO WILL KEEP MENTION OF THUNDER. LOWS WILL BE IN THE
60S.
SUNDAY...COLD FRONT IS STILL EXPECTED TO STALL OUT ACROSS THE
MIDSOUTH LIKELY IN THE AREA FROM JACKSON TENNESSEE TO CLARKSDALE
MISSISSIPPI. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP
ALONG AND AHEAD OF THE FRONT. EXPECT HIGHS TO BE COOLER WITH
READINGS IN THE MID 70S TO LOWER 80S.
FRONT WILL EVENTUALLY PUSH BACK NORTHWARD AS A WARM FRONT ON
MONDAY. AS A RESULT...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
CONTINUE SUNDAY NIGHT AND MONDAY. BEST CHANCES WILL OCCUR ALONG
THE FRONT.
STILL HARD TO SAY WHAT EXACTLY WILL HAPPEN DURING THE MONDAY NIGHT
THROUGH WEDNESDAY TIME FRAME. UPPER RIDGE WILL BUILD BACK OVER THE
AREA BUT CHANCES FOR RAIN WILL DEPEND ON IF A DISTURBANCE GETS
TRAPPED UNDERNEATH RIDGE. TOO MANY IF/S RIGHT NOW...SO WILL
CONTINUE WITH FORECAST AS IS. DO EXPECT TEMPERATURES TO RETURN TO
ABOVE NORMAL WITH THE RIDGE BUILDING BACK INTO THE REGION.
00Z MODELS PUSHED TIMING OF NEXT FRONT BACK 24 HOURS BUT 12Z ECMWF
HAS PUSHED TIMING BACK TO THURSDAY NIGHT INTO FRIDAY. 12Z GFS
REMAINS 24 HOURS SLOWER. WILL CONTINUE WITH SMALL POPS DURING THE
THURSDAY NIGHT THROUGH SATURDAY TIME FRAME FOR NOW. TEMPERATURES
WILL COOL DOWN BEHIND NEXT FRONT.
KRM
&&
.AVIATION...
00Z TAF CYCLE
A COLD WEAKENING FRONT WILL APPROACH FROM THE WEST TONIGHT.
SHOWERS APPEAR TO BE SLIGHTLY AHEAD OF SCHEDULE COMPARED TO THE
LAST TAF UPDATE. BROUGHT THEM IN A COUPLE O HOURS SOONER AT ALL
SITES. SHRAS WITH ISOLATED TSRAS ALONG WITH MVFR CIGS AND VSBYS
WILL SPREAD INTO KJBR AROUND 29/06Z...KMEM BY 29/12Z AND KMKL BY
29/14Z. KTUP WILL BE IMPACTED MAINLY AFTER 29/16Z. TOMORROW AS THE
FRONT CONTINUES TO WEAKEN...OUTFLOW FROM SHOWERS AND THUNDERSTORMS
WILL MASK THE ACTUAL FRONT...THUS WINDS WILL BE HIGHLY VARIABLE.
HOWEVER...WIND SPEEDS SHOULD REMAIN FAIRLY WEAK...LESS THAN 8 KTS.
SHOWERS RESULTING IN MVFR CIGS AND VIS WILL LIKELY PREVAIL AT ALL
SITES EXCEPT TUP FOR MOST OF THE DAY TOMORROW.
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 67 77 67 81 / 30 70 40 20
MKL 62 74 62 80 / 10 70 40 20
JBR 65 74 62 80 / 70 70 30 20
TUP 60 83 64 83 / 10 40 20 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
748 PM PDT Sat Sep 28 2013
.SYNOPSIS...
Tonight will be wet and windy with the passage of a strong cold
front. Another stronger cold front will bring more wind and rain
to the region Sunday night into Monday. High mountain snow is
expected Monday into Tuesday. The wild weather will begin to
settle down on Wednesday. The nicest weather of the week will
occur Thursday and Friday, but temperatures will remain below
average through the end of the week.
&&
.DISCUSSION...
The cold front is making its way through western WA early this
evening with widespread moderate rainfall and pockets of heavy
rainfall being reported along the front. Numerous reports of heavy
rainfall of over 2 inches have been reported west of the Cascades
so far with this system. The cold front is expected to push across
eastern WA and into the ID Panhandle overnight. The HRRR model
seems to have a good handle with the timing of the front and the
forecast is reflective of this latest model solution. We are
expecting the front to begin to push east of the Cascade Mountains
after 1100 PM tonight. A strong moist warm sector ahead of the
cold front combined with strong frontal dynamics is expected to
produce moderate to heavy rainfall just out ahead of the cold
front. Heaviest rainfall rates are anticipated closer to the
leading edge of the front. I increased precipitation chances and
rainfall amounts for tonight, primarily across the eastern half of
the forecast area. 12 HR rainfall totals through 500 AM this
morning are expected to generally be between a quarter and a half
an inch across extreme eastern WA with the Panhandle seeing these
totals between a half and three-quarters.
The cold front is expected to have passed southeast of the region
around the early morning hours on Sunday. A chance of showers will
be possible across the ID Panhandle behind the front due to
orographics across this area. The Cascade Crest will also continue
to see showers with the higher elevations above 5500 feet likely
switching over to snow. Locations in between these areas will
likely dry out at least into the morning hours on Sunday.
Winds will continue to be gusty ahead of and especially with
frontal passage. Some observations across the Moses Lake Area, on
the Waterville Plateau and in the Okanogan Valley have reported
gusts of between 40 and 55 mph. Although these winds have not been
quite as windy further east across the Upper Columbia Basin and
into the Spokane/Coeur d`Alene Area and across the Palouse, I do
think we will see a better chance for some stronger winds with
cold front passage. Some locations may see a brief period of
reaching advisory criteria winds where we have canceled the
advisory earlier, but I think these stronger winds will be
relatively brief as the cold front moves over the area. Thus, I do
not anticipate making any updates to the Wind Advisory at this
time. Winds should weaken a bit behind the front as strongest
winds aloft will shift eastward with the cold front. /SVH
&&
.AVIATION...
00Z TAFS: The region will remain in the moist warm sector of a
Pacific storm system through 06Z this evening. Although light rain
will continue at most of the taf locations, cigs are expected to
generally remain above 3 kft agl over the next 6 hours. MVFR vis will
be possible at times under more moderate rain bands. The trailing
cold front will then sweep east of the Cascades pushing through
KEAT and KMWH between 04-06Z; the cold front will then push through
KGEG, KSFF, KCOE, KPUW and KLWS between 06-11Z overnight. This
front will result in some heavier rainfall across the region with
a better chance for cigs/vis down into MVFR category. Low stratus
is expected to develop across extreme eastern WA and into the
Panhandle behind the cold front for at least a few hours. Winds
will shift from the south-southeast to a southwesterly orientation
and become more gusty with cold front passage. Expect some low
level wind shear at KLWS and KEAT through tonight where stronger
winds aloft will have a harder time mixing down to the surface.
/SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 57 45 56 44 56 / 100 50 80 30 20 50
Coeur d`Alene 48 55 44 53 43 55 / 100 70 100 50 30 50
Pullman 48 56 46 56 43 57 / 100 80 90 30 10 30
Lewiston 54 62 50 63 46 64 / 70 70 80 20 10 20
Colville 50 58 45 57 43 57 / 100 60 100 50 30 50
Sandpoint 49 55 43 49 41 53 / 100 80 100 70 70 50
Kellogg 47 52 43 49 40 52 / 100 90 100 90 70 50
Moses Lake 50 66 47 65 45 64 / 40 20 50 10 10 20
Wenatchee 47 62 47 63 45 62 / 40 30 60 10 10 20
Omak 47 64 44 63 40 62 / 70 40 70 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch through late Sunday night for Northern Panhandle.
WA...Flood Watch through late Sunday night for East Slopes Northern
Cascades.
Wind Advisory until 2 AM PDT Sunday for Moses Lake Area-Upper
Columbia Basin-Waterville Plateau.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
923 PM CDT SAT SEP 28 2013
.UPDATE...
THE COLD FRONT CONTINUES TO MAKE STEADY PROGRESS ACROSS THE AREA
THIS EVENING. THE RAIN HAS BEEN RATHER SPOTTY ACROSS THE AREA WITH
ANY MODERATE SHOWERS MOVING THROUGH VERY QUICKLY RESULTING IN VERY
LIMITED RAINFALL AMOUNTS. MOST AREAS ONLY SEEING .05-.10 OF AN
INCH OF RAIN. CURRENT TIMING HAS THE FRONT MOVING THROUGH
MILWAUKEE BY 11 PM. THERE IS ABOUT AN HOUR OF POST FRONTAL RAIN
BEFORE A SHARP CLEARING LINE MOVES IN. THEN ANOTHER QUIET STRETCH
OF WEATHER SETTLES IN FOR THE FIRST HALF OF THE WEEK.
&&
.AVIATION/06Z TAFS/...
BY THE TIME THE 06Z TAFS ARE COMPOSED...CLEARING WILL HAVE WORKED
INTO KMSN...WITH THIS CLEARING HITTING THE KMKE/KUES/KENW BY 07Z.
UNTIL THEN...LOOK FOR A SOME SCATTERED IFR CIGS/VSBYS RIGHT ALONG
AND JUST BEHIND THE PASSING COLD FRONT. THAT FRONT WILL MOVE
THROUGH KMKE AROUND 04Z...KUES ABOUT 03-0330Z AND KENW ABOUT
0430Z. VFR CONDITIONS ARE EXPECTED THROUGH THE REMAINDER OF THE
TAF PERIOD ONCE THE CLEARING ARRIVES.
&&
.MARINE...
WILL LET THE SMALL CRAFT ADVISORY EXPIRE OVER THE SOUTHERN HALF OF
THE MARINE AREAS AT 10 PM AS WINDS ARE DIMINISHING WITH THE SFC
TROF MOVING OVERHEAD. THE NORTHERN HALF WILL CONTINUE THROUGH 1 AM
DUE TO EXPECTED LARGER WAVES UP THERE.
&&
.PREV DISCUSSION... /ISSUED 313 PM CDT SAT SEP 28 2013/
SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM
WATER VAPOR/RUC COMBO SHOWS UPPER TROUGH WITH DECENT 200-300
MILLIBAR SPEED MAX ON THE EASTERN SIDE. BRUNT OF MAIN VORT LIFTING
NORTHEAST FROM NRN MN. TIGHT PRESSURE GRADIENT WITH GUSTY
SOUTH/SOUTHEAST WINDS WILL GRADUALLY GIVE WAY TO WEST/NORTHWEST
WINDS AFTER FROPA. SURFACE LOW LIFTING INTO CANADA FROM MN. BAND
OF SHOWERS TO PUSH THROUGH SRN WI THROUGH THE EVENING HOURS. THIS
WILL BE HELPED ALONG BY THE COMBO OF LOW LEVEL FORCING AND THE
STRONG JET ACTION ON THE EASTERN SIDE OF UPPER TROUGH. DECENT
MOISTURE SURGE WITH LOW TO MID 60S DP/S INTO SE IA. HRRR HAS BEEN
LINGERING PRECIP IN THE FAR SE A BIT LONGER WITH EACH RUN. WILL
HANG ONTO SOME SMALL CHANCES IN THE SE AFTER MIDNIGHT FOR A TIME.
SUNDAY...FORECAST CONFIDENCE HIGH
SURFACE HIGH AND DRY AIRMASS TAKES HOLD. LINGERING 850 COOL POOL
GETS DISPLACED AS WEAK WARM AIR ADVECTION COMMENCES IN THE
AFTERNOON. 925 TEMPS OF 14-16C SET UP FOR HIGHS MOSTLY IN THE
UPPER 60S TO LOW 70S.
SUNDAY NIGHT THROUGH TUESDAY NIGHT...FORECAST CONFIDENCE HIGH
A 100 KT WSWLY POLAR JET STREAM WILL STRETCH FROM THE PACIFIC NW
TO ONTARIO CANADA THROUGH THIS PERIOD WITH LOW AMPLITUDE RIDGING
OVER THE ERN USA. AT THE SFC...A HIGH PRESSURE RIDGE WILL EXTEND
FROM MI TO MO SUN NT THEN MOVE TO THE ERN GREAT LAKES AND THE OHIO
RIVER VALLEY FOR MON AND TUE. ALSO...A STRONG AND OCCLUDED LOW WILL MOVE
EAST ACROSS SRN CANADA DURING THIS TIME.
SLY FLOW AND LOW TO MID LEVEL WARM ADVECTION WILL DEVELOP DURING
THIS PERIOD...BEING WEAK FOR SUN NT...BUT INCREASING MON AND TUE.
A THERMAL RIDGE WILL THEN MOVE ACROSS THE REGION ON TUE AHEAD OF
THE WEAKENING TAIL END OF THE COLD FRONT EXTENDING OUT OF CANADA.
WARM AND DRY CONDITIONS ARE EXPECTED. 925 MB TEMPS IN THE UPPER
TEENS TO LOWER 20S CELSIUS SUPPORT HIGH TEMPS IN THE MID 70S MON
AND LOWER 80S FOR TUE. SUN NT WILL BE COOL DUE TO THE CLOSE
PROXIMITY OF THE HIGH AND DECOUPLED WINDS...BUT WITH MILD NIGHTS
THEREAFTER VIA SLY FLOW AND WAA.
LONG TERM...
WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE LOW TO MEDIUM
THE EXTENDED MODELS DEPICT AN UPPER TROUGH DIGGING INTO THE PACIFIC
NW ON WED...BUT THEN DIFFER ON THE TIMING AND EVOLUTION OF THE
UPPER TROUGH AND EVENTUAL LEE SIDE TROUGH AND CYCLOGENESIS AS IT
MOVES IN THE CENTRAL USA AND GREAT LAKES. THE BEST ESTIMATE AT
THIS TIME IS FOR A SFC TROUGH TO EXTEND FROM THE CENTRAL PLAINS
INTO MN ON THU FOLLOWED BY CYCLOGENESIS NEWD INTO ONTARIO FOR THU
NT INTO SAT. WED WILL BE DRY WITH A SFC RIDGE OVER THE AREA BUT WARM
ADVECTION PCPN WILL BE POSSIBLE WED NT INTO THU NT FOLLOWED BY
FROPA PCPN ANYTIME FROM FRI INTO SAT. ABOVE NORMAL TEMPS WILL
CONTINUE UNTIL COLD FROPA.
AVIATION/00Z TAFS/...VFR CONDITIONS CONTINUE THIS AFTERNOON WITH
GUSTY SSE WINDS AHEAD OF APPROACHING FRONTAL BOUNDARY. WATER VAPOR
SHOWS THE UPPER TROUGH QUITE WELL WITH STRONG JET MAX ON EASTERN
SIDE. RAIN PUSHING INTO WRN WI AND CONTINUE TO SPREAD ACROSS THE
AREA INTO EARLY THIS EVENING. CURRENT TIMING IN TAFS LOOK PRETTY
GOOD SO NOT EXPECTING ANY SIGGY CHANGES THERE...21Z IN KMSN AND
CLOSE TO 00Z AT KMKE. JUST A FEW HOURS OF PRECIP POTENTIAL AT ANY
GIVEN LOCATION. HIGH PRESSURE DOMINATES SUNDAY. MOS AND LLVL RH
PROGS SHOW A GOOD DEAL OF SUNSHINE.
MARINE...THE TIGHT SURFACE PRESSURE GRADIENT AHEAD OF A COLD FRONT
HAS BROUGHT GUSTS AT OR ABOVE CRITERIA. THE SOUTHEAST WINDS WILL
SHIFT SOUTH WITH FREQUENT GUSTS UP TO 25 KNOTS. THE GUSTY WINDS WILL
GENERATE HIGH WAVES...ESPECIALLY NORTH OF PORT WASHINGTON. WINDS
WILL EASE EARLY THIS EVENING AS GRADIENT WEAKENS AHEAD OF
FRONT...BUT 06Z END TIME LOOKS ON TRACK TO ALLOW WAVES TO SUBSIDE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LMZ644>646.
SMALL CRAFT ADVISORY UNTIL 1 AM CDT SUNDAY FOR LMZ643.
&&
$$
UPDATE...99
TONIGHT/SUNDAY AND AVIATION/MARINE...99
SUNDAY NIGHT THROUGH SATURDAY...DAVIS
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY
ISSUED AT 204 PM CDT FRI SEP 27 2013
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE MOVING OVER EASTERN NORTH AMERICA...WHILE A COLD FRONT IS
SHIFTING EVER SO SLIGHTLY TO THE EAST ACROSS THE GREAT PLAINS AND
NORTHERN MISSISSIPPI VALLEY. A FEW SHOWERS HAVE PUSHED INTO FAR
NORTHWEST WISCONSIN AHEAD OF THE FRONT AND A MID-DECK IS JUST
BRUSHING PAST N-C WISCONSIN. OTHERWISE...MAINLY CLEAR SKIES EXIST
ACROSS THE FORECAST AREA EARLY THIS AFTERNOON WITH TEMPS IN THE MID
70S TO LOW 80S. AS THE COLD FRONT GRADUALLY MOVES EAST OVER THE
NEXT 24 HOURS...PRECIP CHANCES ARE THE MAIN FORECAST CONCERN THROUGH
SATURDAY.
TONIGHT...THE COLD FRONT OVER THE NORTHERN MISSISSIPPI VALLEY WILL
MAKE LITTLE PROGRESS TO THE EAST. MID AND UPPER LEVEL DRY AIR OVER
IOWA AND MISSOURI WILL PUSH THE CLOUD COVER OVER NORTHWEST WISCONSIN
NORTH OF THE REGION LATE IN THE EVENING AND OVERNIGHT...WHICH WILL
SET UP A PERIOD OF CLEAR SKIES ACROSS THE FORECAST AREA. UNLIKE THE
PAST FEW NIGHTS...A DECENT PRESSURE GRADIENT WILL BE IN PLACE...SO
WILL NOT HAVE TO WORRY ABOUT FOG FORMATION. LOW TEMPS WILL BE
SEVERAL DEGREES WARMER THAN LAST NIGHT...AND WILL GO WITH MINS IN
THE LOW TO MID 50S.
SATURDAY...CLOUDS WILL BE ON THE INCREASE DURING THE MORNING AS A
STRONG SHORTWAVE FINALLY PUSHES THE COLD FRONT TO THE EAST. MODELS
POINT TOWARD SHOWERS ARRIVING AHEAD OF THE FRONT ACROSS WESTERN
SECTIONS OF THE FORECAST AREA DURING THE EARLY TO MIDDLE AFTERNOON
HOURS. THE FRONT WILL HAVE PWATS UPWARDS OF 1.5 INCHES...AND PLENTY
OF FORCING ALOFT IN THE FORM OF MID-LEVEL FGEN AND DPVA...SO WILL
INCREASE POPS ACROSS THE WESTERN HALF TO NEARLY 100 PCT. THE ONLY
THING LACK IS INSTABILITY SINCE MID-LEVEL LAPSE RATES ARE BETWEEN 5
AND 6 C/KM AND 850-700MB THETAE LAPSE RATES ARE POSITIVE. MODIFYING
A FEW SOUNDINGS SHOW CAPES BETWEEN 50-100 J/KG...SO AN ISOLATED
LIGHTNING STRIKE SEEMS POSSIBLE. SLOWED DOWN THE PRECIP ACROSS THE
EAST A BIT AS MOST MODELS KEEP THE LAKE MICHIGAN SHORELINE DRY
THROUGH 00Z. HIGHS REACHING FROM THE MID TO UPPER 70S...THEN
COOLING AS CLOUDS INCREASE AND RAIN ARRIVES.
.LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
ISSUED AT 204 PM CDT FRI SEP 27 2013
TROF LIFTS OUT OF CENTRAL US ON SUNDAY WITH LESS
AMPLIFIED/PROGRESSIVE FLOW OVER CONUS THROUGH LATE NEXT WEEK.
THROUGH WED...BRUNT OF SHORT WAVE ACTIVITY TO PASS NORTH AND
WEST OF CWA. TAIL END OF SFC FRONT TO PASS THROUGH TUE/WED
PERIOD...THOUGH MOISTURE LIMITED SO EXPECTED TO COME THROUGH DRY.
RATHER MILD PERIOD EXPECTED WITH HIGHS AROUND 70 AND LOWS IN THE
50S.
BY THU...SEE MORE AMPLIFICATION WITH TROF IN THE WEST...THOUGH
PATTERN STILL PROGRESSIVE. MOISTURE EXPECTED TO LIFT NORTH OUT OF
GULF AHEAD OF SYSTEM...WITH SFC WARM FRONT EXPECTED TO BE OVER OR
NEAR STATE ON THU. HAVE CONTINUED CHANCE POPS FOR WED/THU...GIVEN
UNCERTAINTY. COLD FRONT TO APPROACH LATER FRI.
IN NEAR TERM...WILL CONTINUE WITH PROGRESSING FRONT THROUGH REGION
SAT EVENING...ENDING PCPN ALONG LAKESHORE BETWEEN 06Z-09Z. HIGH
PRESSURE TO MOVE IN FOR MOSTLY SUNNY AND DRY DAY. TEMPERATURES SUN
TO RUN NEAR OR ABOVE NORMAL.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1220 PM CDT FRI SEP 27 2013
ONLY SCT TO BKN HIGH CLOUDS ALONG SLOW MOVING COLD FRONT
THROUGH TONIGHT. HOWEVER...LLWS WILL DEVELOP AHEAD OF THE FRONT
THIS EVENING AT ALL TAF SITES. CLOUDS THICKEN SATURDAY MORNING
BEFORE THE COLD FRONT MOVES ACROSS THE AREA SATURDAY AFTERNOON AND
EVENING. IT WILL BE ACCOMPANIED BY MVFR CONDITIONS AND SHOWERS OR
THUNDERSTORMS. GUSTY SOUTH SURFACE WINDS ALSO EXPECTED SATURDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TE
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1211 PM CDT FRI SEP 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CDT FRI SEP 27 2013
MAIN FOCUS IN THE SHORT TERM WILL BE GUSTY SOUTH WINDS AND
UNSEASONABLY WARM TEMPERATURES TODAY.
WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING A HIGHLY AMPLIFIED
RIDGE IN PLACE FROM THE GULF OF MEXICO NORTHWARD THROUGH THE GREAT
LAKES REGION AND INTO EASTERN ONTARIO/QUEBEC. MEANWHILE...A DEEP
TROUGH OF LOW PRESSURE WAS PUSHING INTO THE INTERMOUNTAIN WEST.
SOUTHWEST FLOW BETWEEN THESE TOW SYSTEM WAS DRAWING AN UNSEASONABLY
WARM AIRMASS INTO THE UPPER MISSISSIPPI RIVER REGION. ALSO OF NOW WAS
SOME MID-LEVEL INSTABILITY ASSOCIATED WITH A WEAK EMBEDDED SHORTWAVE
TROUGH EJECTING OUT OF KS INTO NEB. INCREASING 850MB MOISTURE
TRANSPORT AND FAIRLY STRONG ISENTROPIC LIFT ON THE 305K SURFACE PER
THE RAP WAS PRODUCING WIDELY SCATTERED ACCAS/THUNDER IN A BAND FROM
EASTERN SD INTO EASTERN NEB. OTHERWISE...TEMPERATURES ACROSS OUR
AREA EARLY THIS MORNING ARE ALMOST CLOSER TO WHAT WE CAN TYPICALLY
EXPECT FOR DAYTIME HIGHS FOR LATE SEPTEMBER. READINGS AROUND THE
AREA RANGED FROM THE MIDDLE 50S ALONG AN NORTH OF I-94...TO THE
LOWER AND MIDDLE 60S ALONG AND WEST OF THE MISSISSIPPI RIVER.
FOR TODAY...SURFACE HIGH PRESSURE REMAINS ANCHORED ACROSS THE GREAT
LAKES WHILE A COLD FRONTAL BOUNDARY REMAINS IN PLACE FROM NORTHWEST
MN THROUGH CENTRAL NEB. RESULTING TIGHT PRESSURE GRADIENT WILL
PRODUCE GUSTY SOUTH WINDS IN THE 15 TO 25 MPH RANGE WITH GUSTS
AROUND 30-35 MPH...ESPECIALLY ACROSS THE HIGHER TERRAIN OF SOUTHEAST
MN AND NORTHEAST IA. THIS WILL AID IN ADVECTING/MIXING WARMER AIR INTO THE
REGION. NAM SHOWING 925MB TEMPERATURES WARMING INTO THE 21-24C RANGE
BY THIS AFTERNOON. THIS SHOULD RESULT IN PUSHING HIGH TEMPERATURES
TODAY INTO THE UPPER 70S TO THE MIDDLE 80S...WHICH IS NEARLY 15
DEGREES ABOVE NORMAL. HOWEVER...WILL HAVE TO WATCH THAT
AFOREMENTIONED ELEVATED SHRA/TS WEST OF US THROUGH THE DAY. CLOUD
COVER FROM THIS COULD OFFSET WARMING SOME ACROSS PORTIONS OF
NORTHEAST IA/SOUTHEAST MN. TEMPERATURES TODAY WILL BE FLIRTING WITH
RECORD HIGHS. THE RECORD FOR ROCHESTER AND LA CROSSE IS 86 SET IN
1987 AND 1943 RESPECTIVELY.
THE AREA WILL REMAIN FIRMLY ENTRENCHED IN WARM AND INCREASINGLY HUMID
SOUTH FLOW TONIGHT AS THE COLD FRONT APPROACHES BUT REMAINING JUST
WEST OF THE AREA OVERNIGHT. LOOKS LIKE THE AREA WILL REMAIN
RAIN-FREE AS A RESULT SINCE MOST OF THE SHRA/TS ACTIVITY LOOKS
MAINLY POST-FRONTAL AND TIED TO THE MID-LEVEL TROUGH APPROACHING FROM
THE PLAINS. OTHERWISE...PLAN ON UNSEASONABLY MILD OVERNIGHT LOWS IN
THE UPPER 50S TO THE LOWER 60S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 305 AM CDT FRI SEP 27 2013
MODELS ARE IN EXCELLENT AGREEMENT WITH A COLD FRONTAL PASSAGE ACROSS
THE AREA ON SATURDAY. APPEARS ABOUT A 50 MILE WIDE BAND OF SHOWERS
AND EMBEDDED THUNDER WILL BE SEEN WITH THE FRONTAL AND MID-LEVEL
TROUGH PASSAGE. ALTHOUGH THERMODYNAMIC PROFILES/CAPE SEEMS
MINIMAL...CHANCE OF THUNDER WILL BE TIED MORE TO DYNAMIC FORCING
ASSOCIATED WITH RIGHT ENTRANCE REGION OF 300MB JET/STRONG 850-700MB
FRONTOGENETIC FORCING COUPLED WITH NEGATIVE EPV ABOVE THIS.
OTHERWISE...LOOK FOR HIGHS TOPPING OFF IN THE UPPER 60S TO UPPER 70S
AROUND THE NOON HOUR WITH NEARLY STEADY OR SLOWLY FALLING
TEMPERATURES DURING THE AFTERNOON HOURS. PLAN ON SHOWER CHANCES
EXITING THE AREA SATURDAY EVENING WITH CLEARING SKIES OVERNIGHT.
LOWS SATURDAY NIGHT ARE THEN EXPECTED TO DIP INTO THE 40S.
A RIDGE OF HIGH PRESSURE BUILDS INTO THE AREA ON SUNDAY...THEN
SLOWLY BECOME MORE AMPLIFIED THROUGH WEDNESDAY OVERHEAD AND ACROSS
THE EASTERN CONUS. AS A RESULT...LOOK FOR TEMPERATURES TO REMAIN
ABOVE NORMAL INTO NEXT WEEK WITH HIGHS IN THE 70S AND LOWS MAINLY IN
THE 50S.
THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE ON THURSDAY
AS LOW PRESSURE LIFTS OUT OF THE INTERMOUNTAIN WEST TOWARD THE
REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1211 PM CDT FRI SEP 27 2013
A COLD FRONT EXTENDS FROM NORTHWEST MINNESOTA INTO EASTERN SOUTH
DAKOTA EARLY THIS AFTERNOON. GRADIENT AHEAD OF THE FRONT IS TIGHT
ENOUGH TO PRODUCE SOME GUSTS INTO THE 20 TO 25 KNOT RANGE FOR THE
AFTERNOON. THESE WILL DIMINISH LATE THIS AFTERNOON/EARLY THIS
EVENING AS THE LOW LEVEL INVERSION SETS UP AND LIMITS THE MIXING.
AS THIS HAPPENS HOWEVER...THE LOW LEVEL WINDS JUST ABOVE THE
SURFACE LOOK TO INCREASE WITH THE LOW LEVEL JET CREATING A WIND
SHEAR POTENTIAL AT BOTH SITES FOR THE OVERNIGHT HOURS. MIXING
SHOULD RAPIDLY INCREASE SATURDAY MORNING AS THE FRONT MOVES CLOSER
ALLOWING THE WIND SPEED DIFFERENCE TO DECREASE AND DROPPED THE
WIND SHEAR BY 13Z AT BOTH SITES. GOOD FORCING IS EXPECTED TO OCCUR
ALONG AND BEHIND THE FRONT TO PRODUCE A BAND OF SHOWERS. CURRENT
TIMING SHOULD BRING THESE SHOWERS INTO KRST BY MID MORNING WITH
THE WIND SHIFT BEHIND THE COLD FRONT OCCURRING JUST PAST THE VALID
TIME OF THE TAF. SHOWERS SHOULD GET TO KLSE VERY NEAR THE END OF
THE TAF PERIOD SO FOR NOW HAVE NOT INCLUDED THESE IN THE FORECAST.
CONDITIONS LOOK TO INITIALLY START VFR WITH THE SHOWERS BUT QUICKLY
GO DOWN TO MVFR. WOULD NOT BE SURPRISED TO SEE A SHORT PERIOD OF
IFR CEILINGS AT KRST AROUND THE TIME OF THE FRONT PASSAGE.
INSTABILITY LOOKS TO BE VERY LIMITED AND HAVE NOT INCLUDED ANY
MENTION OF THUNDER. HOWEVER...WITH THE STRENGTH OF THE FORCING
THERE COULD BE RUMBLE OR TWO HEARD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1153 AM CDT FRI SEP 27 2013
.UPDATE...
.AVIATION/18Z TAFS/...
VFR CONDITIONS THROUGH THE EVENING. LESS FOG POTENTIAL LATE TONIGHT
WITH THE INCREASING PRESSURE GRADIENT. A NORTH TO SOUTH ORIENTED
COLD FRONT WILL TRACK EAST ACROSS WISCONSIN SATURDAY. THERE IS GOOD
AGREEMENT ABOUT TIMING BETWEEN ALL THE MODELS. ONLY A SMALL CHANCE
FOR THUNDER...SO WILL KEEP IT OUT OF THE TAFS. THE RAIN WILL HIT
MADISON LATE SATURDAY AFTERNOON AND MILWAUKEE EARLY SATURDAY
EVENING. PLAN ON ABOUT A 3 HOUR PERIOD OF LIGHT TO MODERATE RAIN
WITH 0.2 TO 0.4 INCH ACCUMULATION.
&&
.PREV DISCUSSION... /ISSUED 903 AM CDT FRI SEP 27 2013/
UPDATE...THE DENSE FOG ADVISORY HAS BEEN CANCELLED DUE TO FOG
BURNING OFF. THE HIGH TEMPERATURE FORECAST OF NEAR 80F OVER SOUTH
CENTRAL WI AND LOWER 70S NEAR THE LAKE IS ON TARGET FOR TODAY.
AVIATION/18Z TAFS/...COMING LATER THIS MORNING.
PREV DISCUSSION... /ISSUED 320 AM CDT FRI SEP 27 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM TO HIGH
250 MB RIDGE AXIS WILL EXTEND ACROSS EASTERN WISCONSIN AND THEN INTO
LOWER MICHIGAN TONIGHT. THE 500 MB RIDGE AXIS IS A LITTLE FARTHER
EAST WITH SOUTHWEST FLOW ACROSS SOUTHERN WISCONSIN LATER TONIGHT
AHEAD OF THE APPROACHING SHORTWAVE MOVING ACROSS THE CENTRAL AND
NORTHERN PLAINS.
THE 850/700/500 MB LAYERS REMAIN DRY UNTIL LATE TONIGHT WHEN 850 MB
RH INCREASES IN AREAS WEST OF MADISON. THE 850 MB/700 SOUTH JET MAX
REMAINS WEST OF THE AREA THROUGH TONIGHT ALTHOUGH 850 MB WINDS DO
INCREASE TO AROUND 30 KNOTS LATE TONIGHT.
LITTLE CHANCE IN 850/700 MB TEMPERATURES LATER TODAY.
THE SURFACE RIDGE WILL REMAIN OVER THE EASTERN GREAT LAKES BUT THE
PRESSURE GRADIENT INCREASES ESPECIALLY TONIGHT AS THE SOUTHEAST FLOW
INCREASES.
MAIN ISSUE WILL BE THE VERY SHORT TERM WITH FOG. THE LAKE BREEZE HAD
BROUGHT SLIGHTLY HIGHER DEWPOINTS INTO SOUTHEAST AND EAST CENTRAL
WISCONSIN...BUT THE LIGHT FLOW CLEAR SKIES AND GOOD LONG WAVE
RADIATIONAL CONDITIONS HAS CAUSED TEMPERATURES/DEWPOINTS TO COME TO
SATURATION AND HAVE COOLED...WHICH IS HELPING THE FOG TO BECOME MORE
DENSE JUST INLAND FROM THE LAKE. THE HRRR MODEL CONTINUES TO
SHOW ALL OF THE LAKESHORE COUNTIES AND THE NEXT TIER INLAND TO
DEVELOP LOW VISIBILITIES DURING THE EARLY MORNING HOURS. THE DENSE
FOG ADVISORY WILL THEREFOR BE EXPANDED SOUTH. HOWEVER VISIBILITIES
WERE FLUCTUATING BETWEEN 1/4 AND 3 MILES AND THE BOUNDARY LAYER
WINDS WILL INCREASE SLIGHTLY. THEREFORE THE DENSE FOG IS NOT LIKELY
TO BE WIDESPREAD.
THE FOG POTENTIAL IS LESS IN THE FAR WESTERN FORECAST AREA DUE TO AN
INCREASING PRESSURE GRADIENT.
SATURDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
SURFACE LOW PRESSURE SLIDING BY WELL TO THE NORTH WILL DRAG A COLD
FRONT THROUGH SOUTHERN WISCONSIN SATURDAY AFTERNOON INTO THE
EVENING. THERE WILL BE A PRETTY QUICK INCREASE IN PRECIPITABLE WATER
AHEAD OF THE FRONT...GETTING AS HIGH AS 1.80 INCHES ON THE LATEST
MODEL SOUNDINGS. WITH THE HIGH MOISTURE CONTENT AND AMPLE
FRONTOGENETIC LIFT...MAINTAINED HIGH POPS FOR THE AFTERNOON AND
EVENING. NOT SEEING MUCH INSTABILITY IN SOUNDINGS...SO ONLY WENT
WITH ISOLATED THUNDER. MAIN ISSUE FOR THE DAY WILL BE TIMING THE
PRECIP...WITH MODELS STILL DIFFERING BY A COUPLE HOURS.
OVERALL...SHOULD NOT BE A VERY LONG EVENT...WITH THE BULK OF PRECIP
LIKELY MOVING THROUGH IN A FEW HOURS. SINCE THE FRONT IS EXPECTED TO
ARRIVE LATER IN THE DAY...SHOULD BE A GOOD WINDOW TO WARM THINGS UP
AHEAD OF THE FRONT. 925 MB TEMPS WILL APPROACH OR REACH 20C...SO
UPPER 70S STILL SEEM REASONABLE...WITH A FEW SPOTS PROBABLY HITTING
80.
SUNDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM
A WEAKENING TROUGH WILL SLIDE BY TO THE NORTH TUESDAY...BUT
OTHERWISE HIGH PRESSURE WILL MOVE IN SUNDAY AND THEN GENERALLY HOLD
THROUGH THE MIDDLE OF THE WEEK. WENT WITH A DRY FORECAST THROUGH
WEDNESDAY...WITH SOME LOW POPS THURSDAY AS MODELS ARE SHOWING SOME
WARM ADVECTION AHEAD OF DEVELOPING LOW PRESSURE TO THE WEST.
TEMPERATURES WILL BE COOLER SUNDAY BEHIND THE COLD FRONT...THOUGH
HIGHS WILL STILL BE NEAR TO EVEN A COUPLE DEGREES ABOVE NORMAL. WILL
LIKELY SEE ABOVE NORMAL TEMPS THEN THROUGH THURSDAY UNDER MAINLY
SOUTHERLY LOW LEVEL FLOW.
AVIATION/12Z TAFS/...
LIFR FOG ESPECIALLY OVER SOUTHEAST WISCONSIN. SOME IFR/LIFR IN LOW
AREAS AND RIVER VALLEYS OVER SOUTH CENTRAL WISCONSIN. FOG WILL
DISSIPATE DURING THE MID TO LATE MORNING. STILL SOME MOISTURE BELOW
THE INVERSION 4 THSD FT TO GENERATE FEW FAIR WEATHER CUMULUS WITH
VFR CONDITIONS BY AFTERNOON. SURFACE RIDGE WILL REMAIN OVER THE
GREAT LAKES WITH AN INCREASING PRESSURE GRADIENT TONIGHT.
VFR CONDITIONS DURING THE EVENING. LESS FOG POTENTIAL LATE TONIGHT
WITH THE INCREASING PRESSURE GRADIENT.
MARINE...
SOME POTENTIAL FOR FOG ACROSS THE NEARSHORE WATERS IN DEVELOPING
SOUTHEAST FLOW. DEW POINTS MOVING ACROSS THE THE LAKE ARE NOT THAT
HIGH.
WINDS AND WAVES WILL LIKELY REACH SMALL CRAFT ADVISORY LEVELS
SATURDAY INTO SATURDAY EVENING ACROSS THE NEARSHORE WATERS OF LAKE
MICHIGAN. A TIGHT PRESSURE GRADIENT AHEAD OF A COLD FRONT SHOULD
BRING GUSTY SOUTH/SOUTHEAST WINDS UP TO 25 KNOTS. THE GUSTY WINDS
SHOULD GENERATE HIGH WAVES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...DDV
SATURDAY THROUGH THURSDAY...HENTZ
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
903 AM CDT FRI SEP 27 2013
.UPDATE...THE DENSE FOG ADVISORY HAS BEEN CANCELLED DUE TO FOG
BURNING OFF. THE HIGH TEMPERATURE FORECAST OF NEAR 80F OVER SOUTH
CENTRAL WI AND LOWER 70S NEAR THE LAKE IS ON TARGET FOR TODAY.
&&
.AVIATION/18Z TAFS/...COMING LATER THIS MORNING.
&&
.PREV DISCUSSION... /ISSUED 320 AM CDT FRI SEP 27 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM TO HIGH
250 MB RIDGE AXIS WILL EXTEND ACROSS EASTERN WISCONSIN AND THEN INTO
LOWER MICHIGAN TONIGHT. THE 500 MB RIDGE AXIS IS A LITTLE FARTHER
EAST WITH SOUTHWEST FLOW ACROSS SOUTHERN WISCONSIN LATER TONIGHT
AHEAD OF THE APPROACHING SHORTWAVE MOVING ACROSS THE CENTRAL AND
NORTHERN PLAINS.
THE 850/700/500 MB LAYERS REMAIN DRY UNTIL LATE TONIGHT WHEN 850 MB
RH INCREASES IN AREAS WEST OF MADISON. THE 850 MB/700 SOUTH JET MAX
REMAINS WEST OF THE AREA THROUGH TONIGHT ALTHOUGH 850 MB WINDS DO
INCREASE TO AROUND 30 KNOTS LATE TONIGHT.
LITTLE CHANCE IN 850/700 MB TEMPERATURES LATER TODAY.
THE SURFACE RIDGE WILL REMAIN OVER THE EASTERN GREAT LAKES BUT THE
PRESSURE GRADIENT INCREASES ESPECIALLY TONIGHT AS THE SOUTHEAST FLOW
INCREASES.
MAIN ISSUE WILL BE THE VERY SHORT TERM WITH FOG. THE LAKE BREEZE HAD
BROUGHT SLIGHTLY HIGHER DEWPOINTS INTO SOUTHEAST AND EAST CENTRAL
WISCONSIN...BUT THE LIGHT FLOW CLEAR SKIES AND GOOD LONG WAVE
RADIATIONAL CONDITIONS HAS CAUSED TEMPERATURES/DEWPOINTS TO COME TO
SATURATION AND HAVE COOLED...WHICH IS HELPING THE FOG TO BECOME MORE
DENSE JUST INLAND FROM THE LAKE. THE HRRR MODEL CONTINUES TO
SHOW ALL OF THE LAKESHORE COUNTIES AND THE NEXT TIER INLAND TO
DEVELOP LOW VISIBILITIES DURING THE EARLY MORNING HOURS. THE DENSE
FOG ADVISORY WILL THEREFOR BE EXPANDED SOUTH. HOWEVER VISIBILITIES
WERE FLUCTUATING BETWEEN 1/4 AND 3 MILES AND THE BOUNDARY LAYER
WINDS WILL INCREASE SLIGHTLY. THEREFORE THE DENSE FOG IS NOT LIKELY
TO BE WIDESPREAD.
THE FOG POTENTIAL IS LESS IN THE FAR WESTERN FORECAST AREA DUE TO AN
INCREASING PRESSURE GRADIENT.
SATURDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
SURFACE LOW PRESSURE SLIDING BY WELL TO THE NORTH WILL DRAG A COLD
FRONT THROUGH SOUTHERN WISCONSIN SATURDAY AFTERNOON INTO THE
EVENING. THERE WILL BE A PRETTY QUICK INCREASE IN PRECIPITABLE WATER
AHEAD OF THE FRONT...GETTING AS HIGH AS 1.80 INCHES ON THE LATEST
MODEL SOUNDINGS. WITH THE HIGH MOISTURE CONTENT AND AMPLE
FRONTOGENETIC LIFT...MAINTAINED HIGH POPS FOR THE AFTERNOON AND
EVENING. NOT SEEING MUCH INSTABILITY IN SOUNDINGS...SO ONLY WENT
WITH ISOLATED THUNDER. MAIN ISSUE FOR THE DAY WILL BE TIMING THE
PRECIP...WITH MODELS STILL DIFFERING BY A COUPLE HOURS.
OVERALL...SHOULD NOT BE A VERY LONG EVENT...WITH THE BULK OF PRECIP
LIKELY MOVING THROUGH IN A FEW HOURS. SINCE THE FRONT IS EXPECTED TO
ARRIVE LATER IN THE DAY...SHOULD BE A GOOD WINDOW TO WARM THINGS UP
AHEAD OF THE FRONT. 925 MB TEMPS WILL APPROACH OR REACH 20C...SO
UPPER 70S STILL SEEM REASONABLE...WITH A FEW SPOTS PROBABLY HITTING
80.
SUNDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM
A WEAKENING TROUGH WILL SLIDE BY TO THE NORTH TUESDAY...BUT
OTHERWISE HIGH PRESSURE WILL MOVE IN SUNDAY AND THEN GENERALLY HOLD
THROUGH THE MIDDLE OF THE WEEK. WENT WITH A DRY FORECAST THROUGH
WEDNESDAY...WITH SOME LOW POPS THURSDAY AS MODELS ARE SHOWING SOME
WARM ADVECTION AHEAD OF DEVELOPING LOW PRESSURE TO THE WEST.
TEMPERATURES WILL BE COOLER SUNDAY BEHIND THE COLD FRONT...THOUGH
HIGHS WILL STILL BE NEAR TO EVEN A COUPLE DEGREES ABOVE NORMAL. WILL
LIKELY SEE ABOVE NORMAL TEMPS THEN THROUGH THURSDAY UNDER MAINLY
SOUTHERLY LOW LEVEL FLOW.
AVIATION/12Z TAFS/...
LIFR FOG ESPECIALLY OVER SOUTHEAST WISCONSIN. SOME IFR/LIFR IN LOW
AREAS AND RIVER VALLEYS OVER SOUTH CENTRAL WISCONSIN. FOG WILL
DISSIPATE DURING THE MID TO LATE MORNING. STILL SOME MOISTURE BELOW
THE INVERSION 4 THSD FT TO GENERATE FEW FAIR WEATHER CUMULUS WITH
VFR CONDITIONS BY AFTERNOON. SURFACE RIDGE WILL REMAIN OVER THE
GREAT LAKES WITH AN INCREASING PRESSURE GRADIENT TONIGHT.
VFR CONDITIONS DURING THE EVENING. LESS FOG POTENTIAL LATE TONIGHT
WITH THE INCREASING PRESSURE GRADIENT.
MARINE...
SOME POTENTIAL FOR FOG ACROSS THE NEARSHORE WATERS IN DEVELOPING
SOUTHEAST FLOW. DEW POINTS MOVING ACROSS THE THE LAKE ARE NOT THAT
HIGH.
WINDS AND WAVES WILL LIKELY REACH SMALL CRAFT ADVISORY LEVELS
SATURDAY INTO SATURDAY EVENING ACROSS THE NEARSHORE WATERS OF LAKE
MICHIGAN. A TIGHT PRESSURE GRADIENT AHEAD OF A COLD FRONT SHOULD
BRING GUSTY SOUTH/SOUTHEAST WINDS UP TO 25 KNOTS. THE GUSTY WINDS
SHOULD GENERATE HIGH WAVES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...GEHRING
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
SATURDAY THROUGH THURSDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
622 AM CDT FRI SEP 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CDT FRI SEP 27 2013
MAIN FOCUS IN THE SHORT TERM WILL BE GUSTY SOUTH WINDS AND
UNSEASONABLY WARM TEMPERATURES TODAY.
WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING A HIGHLY AMPLIFIED
RIDGE IN PLACE FROM THE GULF OF MEXICO NORTHWARD THROUGH THE GREAT
LAKES REGION AND INTO EASTERN ONTARIO/QUEBEC. MEANWHILE...A DEEP
TROUGH OF LOW PRESSURE WAS PUSHING INTO THE INTERMOUNTAIN WEST.
SOUTHWEST FLOW BETWEEN THESE TOW SYSTEM WAS DRAWING AN UNSEASONABLY
WARM AIRMASS INTO THE UPPER MISSISSIPPI RIVER REGION. ALSO OF NOW WAS
SOME MID-LEVEL INSTABILITY ASSOCIATED WITH A WEAK EMBEDDED SHORTWAVE
TROUGH EJECTING OUT OF KS INTO NEB. INCREASING 850MB MOISTURE
TRANSPORT AND FAIRLY STRONG ISENTROPIC LIFT ON THE 305K SURFACE PER
THE RAP WAS PRODUCING WIDELY SCATTERED ACCAS/THUNDER IN A BAND FROM
EASTERN SD INTO EASTERN NEB. OTHERWISE...TEMPERATURES ACROSS OUR
AREA EARLY THIS MORNING ARE ALMOST CLOSER TO WHAT WE CAN TYPICALLY
EXPECT FOR DAYTIME HIGHS FOR LATE SEPTEMBER. READINGS AROUND THE
AREA RANGED FROM THE MIDDLE 50S ALONG AN NORTH OF I-94...TO THE
LOWER AND MIDDLE 60S ALONG AND WEST OF THE MISSISSIPPI RIVER.
FOR TODAY...SURFACE HIGH PRESSURE REMAINS ANCHORED ACROSS THE GREAT
LAKES WHILE A COLD FRONTAL BOUNDARY REMAINS IN PLACE FROM NORTHWEST
MN THROUGH CENTRAL NEB. RESULTING TIGHT PRESSURE GRADIENT WILL
PRODUCE GUSTY SOUTH WINDS IN THE 15 TO 25 MPH RANGE WITH GUSTS
AROUND 30-35 MPH...ESPECIALLY ACROSS THE HIGHER TERRAIN OF SOUTHEAST
MN AND NORTHEAST IA. THIS WILL AID IN ADVECTING/MIXING WARMER AIR INTO THE
REGION. NAM SHOWING 925MB TEMPERATURES WARMING INTO THE 21-24C RANGE
BY THIS AFTERNOON. THIS SHOULD RESULT IN PUSHING HIGH TEMPERATURES
TODAY INTO THE UPPER 70S TO THE MIDDLE 80S...WHICH IS NEARLY 15
DEGREES ABOVE NORMAL. HOWEVER...WILL HAVE TO WATCH THAT
AFOREMENTIONED ELEVATED SHRA/TS WEST OF US THROUGH THE DAY. CLOUD
COVER FROM THIS COULD OFFSET WARMING SOME ACROSS PORTIONS OF
NORTHEAST IA/SOUTHEAST MN. TEMPERATURES TODAY WILL BE FLIRTING WITH
RECORD HIGHS. THE RECORD FOR ROCHESTER AND LA CROSSE IS 86 SET IN
1987 AND 1943 RESPECTIVELY.
THE AREA WILL REMAIN FIRMLY ENTRENCHED IN WARM AND INCREASINGLY HUMID
SOUTH FLOW TONIGHT AS THE COLD FRONT APPROACHES BUT REMAINING JUST
WEST OF THE AREA OVERNIGHT. LOOKS LIKE THE AREA WILL REMAIN
RAIN-FREE AS A RESULT SINCE MOST OF THE SHRA/TS ACTIVITY LOOKS
MAINLY POST-FRONTAL AND TIED TO THE MID-LEVEL TROUGH APPROACHING FROM
THE PLAINS. OTHERWISE...PLAN ON UNSEASONABLY MILD OVERNIGHT LOWS IN
THE UPPER 50S TO THE LOWER 60S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 305 AM CDT FRI SEP 27 2013
MODELS ARE IN EXCELLENT AGREEMENT WITH A COLD FRONTAL PASSAGE ACROSS
THE AREA ON SATURDAY. APPEARS ABOUT A 50 MILE WIDE BAND OF SHOWERS
AND EMBEDDED THUNDER WILL BE SEEN WITH THE FRONTAL AND MID-LEVEL
TROUGH PASSAGE. ALTHOUGH THERMODYNAMIC PROFILES/CAPE SEEMS
MINIMAL...CHANCE OF THUNDER WILL BE TIED MORE TO DYNAMIC FORCING
ASSOCIATED WITH RIGHT ENTRANCE REGION OF 300MB JET/STRONG 850-700MB
FRONTOGENETIC FORCING COUPLED WITH NEGATIVE EPV ABOVE THIS.
OTHERWISE...LOOK FOR HIGHS TOPPING OFF IN THE UPPER 60S TO UPPER 70S
AROUND THE NOON HOUR WITH NEARLY STEADY OR SLOWLY FALLING
TEMPERATURES DURING THE AFTERNOON HOURS. PLAN ON SHOWER CHANCES
EXITING THE AREA SATURDAY EVENING WITH CLEARING SKIES OVERNIGHT.
LOWS SATURDAY NIGHT ARE THEN EXPECTED TO DIP INTO THE 40S.
A RIDGE OF HIGH PRESSURE BUILDS INTO THE AREA ON SUNDAY...THEN
SLOWLY BECOME MORE AMPLIFIED THROUGH WEDNESDAY OVERHEAD AND ACROSS
THE EASTERN CONUS. AS A RESULT...LOOK FOR TEMPERATURES TO REMAIN
ABOVE NORMAL INTO NEXT WEEK WITH HIGHS IN THE 70S AND LOWS MAINLY IN
THE 50S.
THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE ON THURSDAY
AS LOW PRESSURE LIFTS OUT OF THE INTERMOUNTAIN WEST TOWARD THE
REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 622 AM CDT FRI SEP 27 2013
A SOUTH TO SOUTHEAST FLOW OF DRY AIR...EMANATING OUT OF HIGH
PRESSURE OVER THE GREAT LAKES...WILL HELP MAINTAIN VFR CONDITIONS
THROUGH TONIGHT. THAT FLOW IS EXPECTED TO BE FAIRLY STRONG TODAY
AS AN APPROACHING COLD FRONT OVER MINNESOTA TIGHTENS UP THE
PRESSURE GRADIENT. PLAN ON GUSTS OF 25-30 KT...PERHAPS SLIGHTLY
HIGHER AT RST...TO OCCUR LATE THIS MORNING THROUGH THE AFTERNOON.
THE GUSTS WILL DIMINISH THIS EVENING WITH LOSS OF HEATING.
HOWEVER... IMMEDIATELY THEREAFTER LOW LEVEL WIND SHEAR LOOKS TO
DEVELOP AS SOUTH TO SOUTHWEST 40-45 KT WINDS DEVELOP BETWEEN
1000-1500 FT ABOVE THE SURFACE.
LOOKING AHEAD TO SATURDAY...THE COLD FRONT IS SLATED TO COME
THROUGH THE TAF SITES BETWEEN LATE MORNING AND EARLY AFTERNOON.
IMMEDIATELY IN ITS WAKE...A COUPLE HOURS OF RAIN ALONG WITH MVFR
TO POSSIBLY IFR CEILINGS ARE POSSIBLE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
320 AM CDT FRI SEP 27 2013
.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM TO HIGH
250 MB RIDGE AXIS WILL EXTEND ACROSS EASTERN WISCONSIN AND THEN INTO
LOWER MICHIGAN TONIGHT. THE 500 MB RIDGE AXIS IS A LITTLE FARTHER
EAST WITH SOUTHWEST FLOW ACROSS SOUTHERN WISCONSIN LATER TONIGHT
AHEAD OF THE APPROACHING SHORTWAVE MOVING ACROSS THE CENTRAL AND
NORTHERN PLAINS.
THE 850/700/500 MB LAYERS REMAIN DRY UNTIL LATE TONIGHT WHEN 850 MB
RH INCREASES IN AREAS WEST OF MADISON. THE 850 MB/700 SOUTH JET MAX
REMAINS WEST OF THE AREA THROUGH TONIGHT ALTHOUGH 850 MB WINDS DO
INCREASE TO AROUND 30 KNOTS LATE TONIGHT.
LITTLE CHANCE IN 850/700 MB TEMPERATURES LATER TODAY.
THE SURFACE RIDGE WILL REMAIN OVER THE EASTERN GREAT LAKES BUT THE
PRESSURE GRADIENT INCREASES ESPECIALLY TONIGHT AS THE SOUTHEAST FLOW
INCREASES.
MAIN ISSUE WILL BE THE VERY SHORT TERM WITH FOG. THE LAKE BREEZE HAD
BROUGHT SLIGHTLY HIGHER DEWPOINTS INTO SOUTHEAST AND EAST CENTRAL
WISCONSIN...BUT THE LIGHT FLOW CLEAR SKIES AND GOOD LONG WAVE
RADIATIONAL CONDITIONS HAS CAUSED TEMPERATURES/DEWPOINTS TO COME TO
SATURATION AND HAVE COOLED...WHICH IS HELPING THE FOG TO BECOME MORE
DENSE JUST INLAND FROM THE LAKE. THE HRRR MODEL CONTINUES TO
SHOW ALL OF THE LAKESHORE COUNTIES AND THE NEXT TIER INLAND TO
DEVELOP LOW VISIBILITIES DURING THE EARLY MORNING HOURS. THE DENSE
FOG ADVISORY WILL THEREFOR BE EXPANDED SOUTH. HOWEVER VISIBILITIES
WERE FLUCTUATING BETWEEN 1/4 AND 3 MILES AND THE BOUNDARY LAYER
WINDS WILL INCREASE SLIGHTLY. THEREFORE THE DENSE FOG IS NOT LIKELY
TO BE WIDESPREAD.
THE FOG POTENTIAL IS LESS IN THE FAR WESTERN FORECAST AREA DUE TO AN
INCREASING PRESSURE GRADIENT.
.SATURDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
SURFACE LOW PRESSURE SLIDING BY WELL TO THE NORTH WILL DRAG A COLD
FRONT THROUGH SOUTHERN WISCONSIN SATURDAY AFTERNOON INTO THE
EVENING. THERE WILL BE A PRETTY QUICK INCREASE IN PRECIPITABLE WATER
AHEAD OF THE FRONT...GETTING AS HIGH AS 1.80 INCHES ON THE LATEST
MODEL SOUNDINGS. WITH THE HIGH MOISTURE CONTENT AND AMPLE
FRONTOGENETIC LIFT...MAINTAINED HIGH POPS FOR THE AFTERNOON AND
EVENING. NOT SEEING MUCH INSTABILITY IN SOUNDINGS...SO ONLY WENT
WITH ISOLATED THUNDER. MAIN ISSUE FOR THE DAY WILL BE TIMING THE
PRECIP...WITH MODELS STILL DIFFERING BY A COUPLE HOURS.
OVERALL...SHOULD NOT BE A VERY LONG EVENT...WITH THE BULK OF PRECIP
LIKELY MOVING THROUGH IN A FEW HOURS. SINCE THE FRONT IS EXPECTED TO
ARRIVE LATER IN THE DAY...SHOULD BE A GOOD WINDOW TO WARM THINGS UP
AHEAD OF THE FRONT. 925 MB TEMPS WILL APPROACH OR REACH 20C...SO
UPPER 70S STILL SEEM REASONABLE...WITH A FEW SPOTS PROBABLY HITTING
80.
.SUNDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM
A WEAKENING TROUGH WILL SLIDE BY TO THE NORTH TUESDAY...BUT
OTHERWISE HIGH PRESSURE WILL MOVE IN SUNDAY AND THEN GENERALLY HOLD
THROUGH THE MIDDLE OF THE WEEK. WENT WITH A DRY FORECAST THROUGH
WEDNESDAY...WITH SOME LOW POPS THURSDAY AS MODELS ARE SHOWING SOME
WARM ADVECTION AHEAD OF DEVELOPING LOW PRESSURE TO THE WEST.
TEMPERATURES WILL BE COOLER SUNDAY BEHIND THE COLD FRONT...THOUGH
HIGHS WILL STILL BE NEAR TO EVEN A COUPLE DEGREES ABOVE NORMAL. WILL
LIKELY SEE ABOVE NORMAL TEMPS THEN THROUGH THURSDAY UNDER MAINLY
SOUTHERLY LOW LEVEL FLOW.
&&
.AVIATION/12Z TAFS/...
LIFR FOG ESPECIALLY OVER SOUTHEAST WISCONSIN. SOME IFR/LIFR IN LOW
AREAS AND RIVER VALLEYS OVER SOUTH CENTRAL WISCONSIN. FOG WILL
DISSIPATE DURING THE MID TO LATE MORNING. STILL SOME MOISTURE BELOW
THE INVERSION 4 THSD FT TO GENERATE FEW FAIR WEATHER CUMULUS WITH
VFR CONDITIONS BY AFTERNOON. SURFACE RIDGE WILL REMAIN OVER THE
GREAT LAKES WITH AN INCREASING PRESSURE GRADIENT TONIGHT.
VFR CONDITIONS DURING THE EVENING. LESS FOG POTENTIAL LATE TONIGHT
WITH THE INCREASING PRESSURE GRADIENT.
.MARINE...
SOME POTENTIAL FOR FOG ACROSS THE NEARSHORE WATERS IN DEVELOPING
SOUTHEAST FLOW. DEW POINTS MOVING ACROSS THE THE LAKE ARE NOT THAT
HIGH.
WINDS AND WAVES WILL LIKELY REACH SMALL CRAFT ADVISORY LEVELS
SATURDAY INTO SATURDAY EVENING ACROSS THE NEARSHORE WATERS OF LAKE
MICHIGAN. A TIGHT PRESSURE GRADIENT AHEAD OF A COLD FRONT SHOULD
BRING GUSTY SOUTH/SOUTHEAST WINDS UP TO 25 KNOTS. THE GUSTY WINDS
SHOULD GENERATE HIGH WAVES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR WIZ051-052-
059-060-065-066-070>072.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
SATURDAY THROUGH THURSDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
305 AM CDT FRI SEP 27 2013
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 305 AM CDT FRI SEP 27 2013
MAIN FOCUS IN THE SHORT TERM WILL BE GUSTY SOUTH WINDS AND
UNSEASONABLY WARM TEMPERATURES TODAY.
WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING A HIGHLY AMPLIFIED
RIDGE IN PLACE FROM THE GULF OF MEXICO NORTHWARD THROUGH THE GREAT
LAKES REGION AND INTO EASTERN ONTARIO/QUEBEC. MEANWHILE...A DEEP
TROUGH OF LOW PRESSURE WAS PUSHING INTO THE INTERMOUNTAIN WEST.
SOUTHWEST FLOW BETWEEN THESE TOW SYSTEM WAS DRAWING AN UNSEASONABLY
WARM AIRMASS INTO THE UPPER MISSISSIPPI RIVER REGION. ALSO OF NOW WAS
SOME MID-LEVEL INSTABILITY ASSOCIATED WITH A WEAK EMBEDDED SHORTWAVE
TROUGH EJECTING OUT OF KS INTO NEB. INCREASING 850MB MOISTURE
TRANSPORT AND FAIRLY STRONG ISENTROPIC LIFT ON THE 305K SURFACE PER
THE RAP WAS PRODUCING WIDELY SCATTERED ACCAS/THUNDER IN A BAND FROM
EASTERN SD INTO EASTERN NEB. OTHERWISE...TEMPERATURES ACROSS OUR
AREA EARLY THIS MORNING ARE ALMOST CLOSER TO WHAT WE CAN TYPICALLY
EXPECT FOR DAYTIME HIGHS FOR LATE SEPTEMBER. READINGS AROUND THE
AREA RANGED FROM THE MIDDLE 50S ALONG AN NORTH OF I-94...TO THE
LOWER AND MIDDLE 60S ALONG AND WEST OF THE MISSISSIPPI RIVER.
FOR TODAY...SURFACE HIGH PRESSURE REMAINS ANCHORED ACROSS THE GREAT
LAKES WHILE A COLD FRONTAL BOUNDARY REMAINS IN PLACE FROM NORTHWEST
MN THROUGH CENTRAL NEB. RESULTING TIGHT PRESSURE GRADIENT WILL
PRODUCE GUSTY SOUTH WINDS IN THE 15 TO 25 MPH RANGE WITH GUSTS
AROUND 30-35 MPH...ESPECIALLY ACROSS THE HIGHER TERRAIN OF SOUTHEAST
MN AND NORTHEAST IA. THIS WILL AID IN ADVECTING/MIXING WARMER AIR INTO THE
REGION. NAM SHOWING 925MB TEMPERATURES WARMING INTO THE 21-24C RANGE
BY THIS AFTERNOON. THIS SHOULD RESULT IN PUSHING HIGH TEMPERATURES
TODAY INTO THE UPPER 70S TO THE MIDDLE 80S...WHICH IS NEARLY 15
DEGREES ABOVE NORMAL. HOWEVER...WILL HAVE TO WATCH THAT
AFOREMENTIONED ELEVATED SHRA/TS WEST OF US THROUGH THE DAY. CLOUD
COVER FROM THIS COULD OFFSET WARMING SOME ACROSS PORTIONS OF
NORTHEAST IA/SOUTHEAST MN. TEMPERATURES TODAY WILL BE FLIRTING WITH
RECORD HIGHS. THE RECORD FOR ROCHESTER AND LA CROSSE IS 86 SET IN
1987 AND 1943 RESPECTIVELY.
THE AREA WILL REMAIN FIRMLY ENTRENCHED IN WARM AND INCREASINGLY HUMID
SOUTH FLOW TONIGHT AS THE COLD FRONT APPROACHES BUT REMAINING JUST
WEST OF THE AREA OVERNIGHT. LOOKS LIKE THE AREA WILL REMAIN
RAIN-FREE AS A RESULT SINCE MOST OF THE SHRA/TS ACTIVITY LOOKS
MAINLY POST-FRONTAL AND TIED TO THE MID-LEVEL TROUGH APPROACHING FROM
THE PLAINS. OTHERWISE...PLAN ON UNSEASONABLY MILD OVERNIGHT LOWS IN
THE UPPER 50S TO THE LOWER 60S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 305 AM CDT FRI SEP 27 2013
MODELS ARE IN EXCELLENT AGREEMENT WITH A COLD FRONTAL PASSAGE ACROSS
THE AREA ON SATURDAY. APPEARS ABOUT A 50 MILE WIDE BAND OF SHOWERS
AND EMBEDDED THUNDER WILL BE SEEN WITH THE FRONTAL AND MID-LEVEL
TROUGH PASSAGE. ALTHOUGH THERMODYNAMIC PROFILES/CAPE SEEMS
MINIMAL...CHANCE OF THUNDER WILL BE TIED MORE TO DYNAMIC FORCING
ASSOCIATED WITH RIGHT ENTRANCE REGION OF 300MB JET/STRONG 850-700MB
FRONTOGENETIC FORCING COUPLED WITH NEGATIVE EPV ABOVE THIS.
OTHERWISE...LOOK FOR HIGHS TOPPING OFF IN THE UPPER 60S TO UPPER 70S
AROUND THE NOON HOUR WITH NEARLY STEADY OR SLOWLY FALLING
TEMPERATURES DURING THE AFTERNOON HOURS. PLAN ON SHOWER CHANCES
EXITING THE AREA SATURDAY EVENING WITH CLEARING SKIES OVERNIGHT.
LOWS SATURDAY NIGHT ARE THEN EXPECTED TO DIP INTO THE 40S.
A RIDGE OF HIGH PRESSURE BUILDS INTO THE AREA ON SUNDAY...THEN
SLOWLY BECOME MORE AMPLIFIED THROUGH WEDNESDAY OVERHEAD AND ACROSS
THE EASTERN CONUS. AS A RESULT...LOOK FOR TEMPERATURES TO REMAIN
ABOVE NORMAL INTO NEXT WEEK WITH HIGHS IN THE 70S AND LOWS MAINLY IN
THE 50S.
THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS TO BE ON THURSDAY
AS LOW PRESSURE LIFTS OUT OF THE INTERMOUNTAIN WEST TOWARD THE
REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT
1110 PM CDT THU SEP 26 2013
TIGHT PRESSURE GRADIENT WILL SIT ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY THROUGH FRIDAY EVENING...KEEPING THE ATMOSPHERE FAIRLY
STIRRED IN THE VERTICAL. KLSE HAS DECOUPLED...RESULTING IN CONCERNS
FOR LLWS. LATEST RAP/NAM BUFKIT SOUNDINGS NOT AS ROBUST WITH THE SUB
2 KFT WINDS AS THEY WERE EARLIER IN THE DAY...BUT IT IS BLOWING
PRETTY GOOD HERE AT THE NWS OFFICE. WILL STICK WITH THE LLWS FOR
NOW.
BREEZY ON FRIDAY...WITH MIXING RESULTING IN LATE MORNING/AFTERNOON
GUSTS. A FEW 30 KTS AT KRST NOT OUT OF THE QUESTION. SHOULD SEE SOME
INCREASE IN HIGH/MID LEVEL CLOUDS FRIDAY AFTERNOON...AHEAD OF AN
APPROACHING COLD FRONT. CIGS WILL LOWER TOWARD SAT MORNING...WITH
SHRA/TS LIKELY FOR A FEW HOURS ON SAT. EXPECT SOME MVFR CIGS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1241 PM MDT FRI SEP 27 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 415 AM MDT FRI SEP 27 2013
INFRARED IMAGERY THIS MORNING SHOWS THE COLD CLOUD TOPS ASSOCIATED
WITH THE UPPER LEVEL SYSTEM MAINLY ACROSS CARBON COUNTY AND
LOCATIONS WESTWARD. PRECIP TYPE HAS BEEN RAIN SO FAR ACROSS LOWER
ELEVATIONS OF CONVERSE AND CARBON COUNTIES WITH TEMPS GENERALLY IN
THE MID-TO-UPPER 30S. STILL LOOKS LIKE THE FREEZING LEVEL WILL BE
AROUND 8000 FT DURING THE PERIOD OF HIGHEST PRECIP RATES. GOOD
ISENTROPIC LIFT AND FRONTAL FORCING WILL PROGRESS EASTWARD ACROSS
THE CWA THROUGH THE AFTERNOON. BOTH THE GFS AND NAM SHOW MIDLEVEL
FRONTOGENESIS INCREASING TO THE EAST OF THE LARAMIE RANGE DURING
THE AFTERNOON SO HAVE LIKELY POPS ACROSS MUCH OF THE PLAINS. QPF
AMOUNTS WITH THIS SYSTEM WILL BE LIMITED BY THE PROGRESSIVE NATURE
OF THIS SYSTEM AS THE UPPER LEVEL TROUGH QUICKLY SCOOTS EASTWARD.
SNOWFALL AMOUNTS IN THE HIGHER ELEVATIONS ABOVE 8000 FT ARE
EXPECTED TO BE IN THE 1-3 INCH RANGE. OTHER CONCERN THROUGH THIS
MORNING IS THE AREAS OF FOG ALONG THE SOUTHERN LARAMIE RANGE.
INCLUDED FOG THROUGH MID-MORNING BUT THE HRRR MODEL SHOWS LIFR
CONDITIONS ALONG THE RANGE PERSISTING THROUGH MIDDAY UNTIL AFTER
THE FROPA.
WINDS WILL BE QUITE BREEZY BEHIND THE FROPA...PARTICULARLY ACROSS
ALBANY AND LARAMIE COUNTIES IN SOUTHEAST WY. THE GFS SHOWS
WESTERLY WINDS TO 50 KTS JUST ABOVE THE SURFACE WHEREAS THE NAM IS
WEAKER AT AROUND 40 KTS. GOOD COLD AIR ADVECTION WILL ENHANCE
DOWNWARD TRANSPORT OF THE WINDS BUT LLVL MIXING WILL NOT BE IDEAL
SINCE THE STRONGEST WINDS WILL OCCUR DURING THE LATE EVENING
THROUGH THE NIGHT. AT THIS TIME EXPECTING GUSTS TO 35-45 MPH
OVERNIGHT. TEMPS WILL DROP BELOW FREEZING IN THE LOWER ELEVATIONS
TO THE WEST OF THE LARAMIE RANGE. HOWEVER...SINCE THESE AREAS HAVE
SEEN SUB-FREEZING TEMPS ALREADY THIS FALL SEASON...DID NOT ISSUE
ANY FREEZING HEADLINES THERE. TEMPS TO THE EAST OF THE LARAMIE
RANGE WILL LIKELY BE ABOVE 36 AS THE BREEZY CONDITIONS WILL
PREVENT OPTIMAL RADIATIONAL COOLING. CONVERSE COUNTY MAY GET CLOSE
TO A FROST ADVISORY WITH WEAKER WINDS THROUGH MUCH OF THE NIGHT.
TEMPS WILL WARM TO AROUND AVERAGE ON SATURDAY AS HEIGHTS RISE
BEHIND THE UPPER LEVEL TROUGH. STILL GOING TO BE QUITE BREEZY IN
SOUTHEAST WY WITH 700MB WINDS AT 35-40 KTS AND GOOD MIXING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 415 AM MDT FRI SEP 27 2013
FAIRLY ZONAL FLOW INTO THE NRN ROCKIES WILL PERIODICALLY BACK TO
THE SOUTHWEST THROUGH THE MIDDLE OF NEXT WEEK AS A SERIES OF
SHORTWAVES RIDE A 130+ KNOT JET STREAK NORTH OF THE CWA. THIS
PATTERN SUGGESTS UNSEASONABLY WARM CONDITIONS ALONG WITH
BREEZY CONDITIONS ESPECIALLY FOR AREAS ALONG AND WEST OF
INTERSTATE 25. SO...EXPECT DRY CONDITIONS TO PREVAIL SUNDAY THROUGH
WEDNESDAY. H7 TEMPERATURES OF 8-10C WILL YIELD UPPER 60S WEST OF THE
LARAMIE RANGE AND 70S/LOW 80S OUT ON THE EASTERN PLAINS FOR SUNDAY
AND MONDAY. ONE OF THE SERIES OF THE AFOREMENTIONED SHORTWAVES WILL
TRACK NORTH OF THE CWFA LATE MONDAY...DRAGGING A SURFACE BOUNDARY
THROUGH. H7 TEMPERATURES WILL DIP A FEW DEGREES IN WEAK LLVL CAA ON
TUESDAY. THIS WILL YIELD A SLIGHT COOL DOWN FOR TUESDAY MID 60S OVR
CARBON/ALBANY COUNTIES AND 70S EAST OF THE MOUNTAINS.
ADDITIONALLY...A DEVELOPING LEE-SIDE SFC TROF WILL AMPLIFY ON SUNDAY
AND MONDAY AS WELL...INCREASING LLVL SFC WINDS. H7 WIND PROGS PEAK
AT AROUND 40 KNOTS. SO...DO NOT ANTICIPATE A HIGH WIND EVENT HOWEVER
WOULD EXPECT 40 TO 50 MPH TO BE COMMON ESPECIALLY NR ARLINGTON AND
ALONG THE SOUTHERN LARAMIE RANGE AND ADJACENT FOOTHILLS.
ADDITIONALLY...WARM TEMPERATURES...BREEZY SOUTHWEST WINDS AND DRY
AFTERNOON HUMIDITIES WILL HEIGHTEN FIRE WEATHER CONCERNS LATE IN THE
WEEKEND AND EARLY NEXT WEEK.
THE NEXT LONGWAVE TROF WILL SWING ONTO THE WEST COAST LATE
WEDNESDAY. FLOW WILL BACK TO THE SOUTHWEST OVER THE INTERMOUNTAIN
WEST IN ADVANCE OF THIS FEATURE. LATEST MEDIUM RANGE GUIDANCE DIFFER
SOME ON THE TIMING...WITH THE ECMWF THE SLOWEST AND COLDEST. GIVEN
TIMING UNCERTAINTY...DID BEGIN TO INTRODUCE PRECIPITATION CHANCES AS
EARLY AS WEDNESDAY NIGHT AND THURSDAY. HOWEVER...IF THE CURRENT
TRENDS CONTINUE WOULD SUSPECT THAT THIS MAY END UP BEING A BIT EARLY
AND THAT THE BEST CHANCES FOR PRECIPITATION WOULD HOLD OFF UNTIL
THURSDAY NIGHT AND FRIDAY. THE LATEST ECMWF WOULD BE COLD ENOUGH TO
SUPPORT SNOW FRIDAY NIGHT/EARLY SATURDAY. ALTHOUGH STILL TOO FAR OUT
TO FEEL MUCH CONFIDENCE...WILL NEED TO KEEP AN EYE ON THIS SYSTEM
OVER THE COMING DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY MORNING)
ISSUED AT 1241 PM MDT FRI SEP 27 2013
A BAND OF RAIN IS MOVING NORTHEAST OFF THE SOUTHERN LARAMIE RANGE
AT 18Z...AND WILL BECOME MORE WIDESPREAD ACROSS THE PLAINS OF
SOUTHEAST WYOMING AND THE WESTERN NEBRASKA PANHANDLE THROUGH THE
AFTERNOON. LOOKING AT MVFR TO IFR CONDITIONS IN RAIN. AHEAD OF
THIS BAND...LOW STRATUS WILL PERSIST IN NORTHERLY WINDS. THE
MAIN COLD FRONT IS MOVING THROUGH THE MOUNTAINS ZONES AT THIS
HOUR...AND WILL TREK EASTWARD THROUGH THE AFTERNOON. WINDS WILL
TURN TO THE WEST BEHIND THE FRONT AND WILL GUST 25 TO 30 MPH. A
FEW SHOWERS WILL PERSIST OVER THE MOUNTAINS FOR A FEW HOURS BEHIND
THE FRONT...OTHERWISE CONDITIONS WILL IMPROVE WITH FROPA.
&&
.FIRE WEATHER...
ISSUED AT 415 AM MDT FRI SEP 27 2013
WIDESPREAD SHOWERS WILL OCCUR ACROSS THE REGION THROUGH THIS
EVENING AS AN UPPER LEVEL SYSTEM MOVES OVERHEAD. TEMPERATURES WILL
RISE BY THIS WEEKEND AND INTO EARLY NEXT WEEK AND DRIER AIR WILL
MOVE INTO THE AREA...CAUSING MINIMUM AFTERNOON HUMIDITIES TO DROP
INTO THE 15-20 PERCENT RANGE BY SUNDAY AND MONDAY. WEST TO SOUTHWEST
WINDS WILL BE QUITE BREEZY ESPECIALLY OVER SOUTHEAST WYOMING ON
SUNDAY AND MONDAY WITH OCCASIONAL GUSTS TO 30-40 MPH. THUS...AN
ELEVATED FIRE WEATHER THREAT WILL EXIST WHERE FUELS STILL SUPPORT
FIRE GROWTH.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...RJM
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
632 AM MDT FRI SEP 27 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 415 AM MDT FRI SEP 27 2013
INFRARED IMAGERY THIS MORNING SHOWS THE COLD CLOUD TOPS ASSOCIATED
WITH THE UPPER LEVEL SYSTEM MAINLY ACROSS CARBON COUNTY AND
LOCATIONS WESTWARD. PRECIP TYPE HAS BEEN RAIN SO FAR ACROSS LOWER
ELEVATIONS OF CONVERSE AND CARBON COUNTIES WITH TEMPS GENERALLY IN
THE MID-TO-UPPER 30S. STILL LOOKS LIKE THE FREEZING LEVEL WILL BE
AROUND 8000 FT DURING THE PERIOD OF HIGHEST PRECIP RATES. GOOD
ISENTROPIC LIFT AND FRONTAL FORCING WILL PROGRESS EASTWARD ACROSS
THE CWA THROUGH THE AFTERNOON. BOTH THE GFS AND NAM SHOW MIDLEVEL
FRONTOGENESIS INCREASING TO THE EAST OF THE LARAMIE RANGE DURING
THE AFTERNOON SO HAVE LIKELY POPS ACROSS MUCH OF THE PLAINS. QPF
AMOUNTS WITH THIS SYSTEM WILL BE LIMITED BY THE PROGRESSIVE NATURE
OF THIS SYSTEM AS THE UPPER LEVEL TROUGH QUICKLY SCOOTS EASTWARD.
SNOWFALL AMOUNTS IN THE HIGHER ELEVATIONS ABOVE 8000 FT ARE
EXPECTED TO BE IN THE 1-3 INCH RANGE. OTHER CONCERN THROUGH THIS
MORNING IS THE AREAS OF FOG ALONG THE SOUTHERN LARAMIE RANGE.
INCLUDED FOG THROUGH MID-MORNING BUT THE HRRR MODEL SHOWS LIFR
CONDITIONS ALONG THE RANGE PERSISTING THROUGH MIDDAY UNTIL AFTER
THE FROPA.
WINDS WILL BE QUITE BREEZY BEHIND THE FROPA...PARTICULARLY ACROSS
ALBANY AND LARAMIE COUNTIES IN SOUTHEAST WY. THE GFS SHOWS
WESTERLY WINDS TO 50 KTS JUST ABOVE THE SURFACE WHEREAS THE NAM IS
WEAKER AT AROUND 40 KTS. GOOD COLD AIR ADVECTION WILL ENHANCE
DOWNWARD TRANSPORT OF THE WINDS BUT LLVL MIXING WILL NOT BE IDEAL
SINCE THE STRONGEST WINDS WILL OCCUR DURING THE LATE EVENING
THROUGH THE NIGHT. AT THIS TIME EXPECTING GUSTS TO 35-45 MPH
OVERNIGHT. TEMPS WILL DROP BELOW FREEZING IN THE LOWER ELEVATIONS
TO THE WEST OF THE LARAMIE RANGE. HOWEVER...SINCE THESE AREAS HAVE
SEEN SUB-FREEZING TEMPS ALREADY THIS FALL SEASON...DID NOT ISSUE
ANY FREEZING HEADLINES THERE. TEMPS TO THE EAST OF THE LARAMIE
RANGE WILL LIKELY BE ABOVE 36 AS THE BREEZY CONDITIONS WILL
PREVENT OPTIMAL RADIATIONAL COOLING. CONVERSE COUNTY MAY GET CLOSE
TO A FROST ADVISORY WITH WEAKER WINDS THROUGH MUCH OF THE NIGHT.
TEMPS WILL WARM TO AROUND AVERAGE ON SATURDAY AS HEIGHTS RISE
BEHIND THE UPPER LEVEL TROUGH. STILL GOING TO BE QUITE BREEZY IN
SOUTHEAST WY WITH 700MB WINDS AT 35-40 KTS AND GOOD MIXING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 415 AM MDT FRI SEP 27 2013
FAIRLY ZONAL FLOW INTO THE NRN ROCKIES WILL PERIODICALLY BACK TO
THE SOUTHWEST THROUGH THE MIDDLE OF NEXT WEEK AS A SERIES OF
SHORTWAVES RIDE A 130+ KNOT JET STREAK NORTH OF THE CWA. THIS
PATTERN SUGGESTS UNSEASONABLY WARM CONDITIONS ALONG WITH
BREEZY CONDITIONS ESPECIALLY FOR AREAS ALONG AND WEST OF
INTERSTATE 25. SO...EXPECT DRY CONDITIONS TO PREVAIL SUNDAY THROUGH
WEDNESDAY. H7 TEMPERATURES OF 8-10C WILL YIELD UPPER 60S WEST OF THE
LARAMIE RANGE AND 70S/LOW 80S OUT ON THE EASTERN PLAINS FOR SUNDAY
AND MONDAY. ONE OF THE SERIES OF THE AFOREMENTIONED SHORTWAVES WILL
TRACK NORTH OF THE CWFA LATE MONDAY...DRAGGING A SURFACE BOUNDARY
THROUGH. H7 TEMPERATURES WILL DIP A FEW DEGREES IN WEAK LLVL CAA ON
TUESDAY. THIS WILL YIELD A SLIGHT COOL DOWN FOR TUESDAY MID 60S OVR
CARBON/ALBANY COUNTIES AND 70S EAST OF THE MOUNTAINS.
ADDITIONALLY...A DEVELOPING LEE-SIDE SFC TROF WILL AMPLIFY ON SUNDAY
AND MONDAY AS WELL...INCREASING LLVL SFC WINDS. H7 WIND PROGS PEAK
AT AROUND 40 KNOTS. SO...DO NOT ANTICIPATE A HIGH WIND EVENT HOWEVER
WOULD EXPECT 40 TO 50 MPH TO BE COMMON ESPECIALLY NR ARLINGTON AND
ALONG THE SOUTHERN LARAMIE RANGE AND ADJACENT FOOTHILLS.
ADDITIONALLY...WARM TEMPERATURES...BREEZY SOUTHWEST WINDS AND DRY
AFTERNOON HUMIDITIES WILL HEIGHTEN FIRE WEATHER CONCERNS LATE IN THE
WEEKEND AND EARLY NEXT WEEK.
THE NEXT LONGWAVE TROF WILL SWING ONTO THE WEST COAST LATE
WEDNESDAY. FLOW WILL BACK TO THE SOUTHWEST OVER THE INTERMOUNTAIN
WEST IN ADVANCE OF THIS FEATURE. LATEST MEDIUM RANGE GUIDANCE DIFFER
SOME ON THE TIMING...WITH THE ECMWF THE SLOWEST AND COLDEST. GIVEN
TIMING UNCERTAINTY...DID BEGIN TO INTRODUCE PRECIPITATION CHANCES AS
EARLY AS WEDNESDAY NIGHT AND THURSDAY. HOWEVER...IF THE CURRENT
TRENDS CONTINUE WOULD SUSPECT THAT THIS MAY END UP BEING A BIT EARLY
AND THAT THE BEST CHANCES FOR PRECIPITATION WOULD HOLD OFF UNTIL
THURSDAY NIGHT AND FRIDAY. THE LATEST ECMWF WOULD BE COLD ENOUGH TO
SUPPORT SNOW FRIDAY NIGHT/EARLY SATURDAY. ALTHOUGH STILL TOO FAR OUT
TO FEEL MUCH CONFIDENCE...WILL NEED TO KEEP AN EYE ON THIS SYSTEM
OVER THE COMING DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 627 AM MDT FRI SEP 27 2013
STILL EXPECTING IFR CONDITIONS TO CONTINUE AT KCYS THROUGH THE
MORNING IN MOIST EAST UPSLOPE WINDS. KEPT THE NEBRASKA PANHANDLE
WITH MVFR CIGS. A BAND OF RAIN SHOWERS WILL MOVE EASTWARD ACROSS
THE REGION DURING THE LATE MORNING THROUGH THE AFTERNOON BEHIND A
COLD FRONT. NORTHWEST WIND GUSTS TO 25-30 MPH WILL BE POSSIBLE
AFTER THE FRONTAL PASSAGE. SHOWERS WILL COME TO AN END DURING THE
EVENING...HOWEVER BREEZY WINDS WILL CONTINUE THROUGH THE REMAINDER
OF THE TAF PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 415 AM MDT FRI SEP 27 2013
WIDESPREAD SHOWERS WILL OCCUR ACROSS THE REGION THROUGH THIS
EVENING AS AN UPPER LEVEL SYSTEM MOVES OVERHEAD. TEMPERATURES WILL
RISE BY THIS WEEKEND AND INTO EARLY NEXT WEEK AND DRIER AIR WILL
MOVE INTO THE AREA...CAUSING MINIMUM AFTERNOON HUMIDITIES TO DROP
INTO THE 15-20 PERCENT RANGE BY SUNDAY AND MONDAY. WEST TO SOUTHWEST
WINDS WILL BE QUITE BREEZY ESPECIALLY OVER SOUTHEAST WYOMING ON
SUNDAY AND MONDAY WITH OCCASIONAL GUSTS TO 30-40 MPH. THUS...AN
ELEVATED FIRE WEATHER THREAT WILL EXIST WHERE FUELS STILL SUPPORT
FIRE GROWTH.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...FINCH
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
437 AM MDT FRI SEP 27 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 415 AM MDT FRI SEP 27 2013
INFRARED IMAGERY THIS MORNING SHOWS THE COLD CLOUD TOPS ASSOCIATED
WITH THE UPPER LEVEL SYSTEM MAINLY ACROSS CARBON COUNTY AND
LOCATIONS WESTWARD. PRECIP TYPE HAS BEEN RAIN SO FAR ACROSS LOWER
ELEVATIONS OF CONVERSE AND CARBON COUNTIES WITH TEMPS GENERALLY IN
THE MID-TO-UPPER 30S. STILL LOOKS LIKE THE FREEZING LEVEL WILL BE
AROUND 8000 FT DURING THE PERIOD OF HIGHEST PRECIP RATES. GOOD
ISENTROPIC LIFT AND FRONTAL FORCING WILL PROGRESS EASTWARD ACROSS
THE CWA THROUGH THE AFTERNOON. BOTH THE GFS AND NAM SHOW MIDLEVEL
FRONTOGENESIS INCREASING TO THE EAST OF THE LARAMIE RANGE DURING
THE AFTERNOON SO HAVE LIKELY POPS ACROSS MUCH OF THE PLAINS. QPF
AMOUNTS WITH THIS SYSTEM WILL BE LIMITED BY THE PROGRESSIVE NATURE
OF THIS SYSTEM AS THE UPPER LEVEL TROUGH QUICKLY SCOOTS EASTWARD.
SNOWFALL AMOUNTS IN THE HIGHER ELEVATIONS ABOVE 8000 FT ARE
EXPECTED TO BE IN THE 1-3 INCH RANGE. OTHER CONCERN THROUGH THIS
MORNING IS THE AREAS OF FOG ALONG THE SOUTHERN LARAMIE RANGE.
INCLUDED FOG THROUGH MID-MORNING BUT THE HRRR MODEL SHOWS LIFR
CONDITIONS ALONG THE RANGE PERSISTING THROUGH MIDDAY UNTIL AFTER
THE FROPA.
WINDS WILL BE QUITE BREEZY BEHIND THE FROPA...PARTICULARLY ACROSS
ALBANY AND LARAMIE COUNTIES IN SOUTHEAST WY. THE GFS SHOWS
WESTERLY WINDS TO 50 KTS JUST ABOVE THE SURFACE WHEREAS THE NAM IS
WEAKER AT AROUND 40 KTS. GOOD COLD AIR ADVECTION WILL ENHANCE
DOWNWARD TRANSPORT OF THE WINDS BUT LLVL MIXING WILL NOT BE IDEAL
SINCE THE STRONGEST WINDS WILL OCCUR DURING THE LATE EVENING
THROUGH THE NIGHT. AT THIS TIME EXPECTING GUSTS TO 35-45 MPH
OVERNIGHT. TEMPS WILL DROP BELOW FREEZING IN THE LOWER ELEVATIONS
TO THE WEST OF THE LARAMIE RANGE. HOWEVER...SINCE THESE AREAS HAVE
SEEN SUB-FREEZING TEMPS ALREADY THIS FALL SEASON...DID NOT ISSUE
ANY FREEZING HEADLINES THERE. TEMPS TO THE EAST OF THE LARAMIE
RANGE WILL LIKELY BE ABOVE 36 AS THE BREEZY CONDITIONS WILL
PREVENT OPTIMAL RADIATIONAL COOLING. CONVERSE COUNTY MAY GET CLOSE
TO A FROST ADVISORY WITH WEAKER WINDS THROUGH MUCH OF THE NIGHT.
TEMPS WILL WARM TO AROUND AVERAGE ON SATURDAY AS HEIGHTS RISE
BEHIND THE UPPER LEVEL TROUGH. STILL GOING TO BE QUITE BREEZY IN
SOUTHEAST WY WITH 700MB WINDS AT 35-40 KTS AND GOOD MIXING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 415 AM MDT FRI SEP 27 2013
FAIRLY ZONAL FLOW INTO THE NRN ROCKIES WILL PERIODICALLY BACK TO
THE SOUTHWEST THROUGH THE MIDDLE OF NEXT WEEK AS A SERIES OF
SHORTWAVES RIDE A 130+ KNOT JET STREAK NORTH OF THE CWA. THIS
PATTERN SUGGESTS UNSEASONABLY WARM CONDITIONS ALONG WITH
BREEZY CONDITIONS ESPECIALLY FOR AREAS ALONG AND WEST OF
INTERSTATE 25. SO...EXPECT DRY CONDITIONS TO PREVAIL SUNDAY THROUGH
WEDNESDAY. H7 TEMPERATURES OF 8-10C WILL YIELD UPPER 60S WEST OF THE
LARAMIE RANGE AND 70S/LOW 80S OUT ON THE EASTERN PLAINS FOR SUNDAY
AND MONDAY. ONE OF THE SERIES OF THE AFOREMENTIONED SHORTWAVES WILL
TRACK NORTH OF THE CWFA LATE MONDAY...DRAGGING A SURFACE BOUNDARY
THROUGH. H7 TEMPERATURES WILL DIP A FEW DEGREES IN WEAK LLVL CAA ON
TUESDAY. THIS WILL YIELD A SLIGHT COOL DOWN FOR TUESDAY MID 60S OVR
CARBON/ALBANY COUNTIES AND 70S EAST OF THE MOUNTAINS.
ADDITIONALLY...A DEVELOPING LEE-SIDE SFC TROF WILL AMPLIFY ON SUNDAY
AND MONDAY AS WELL...INCREASING LLVL SFC WINDS. H7 WIND PROGS PEAK
AT AROUND 40 KNOTS. SO...DO NOT ANTICIPATE A HIGH WIND EVENT HOWEVER
WOULD EXPECT 40 TO 50 MPH TO BE COMMON ESPECIALLY NR ARLINGTON AND
ALONG THE SOUTHERN LARAMIE RANGE AND ADJACENT FOOTHILLS.
ADDITIONALLY...WARM TEMPERATURES...BREEZY SOUTHWEST WINDS AND DRY
AFTERNOON HUMIDITIES WILL HEIGHTEN FIRE WEATHER CONCERNS LATE IN THE
WEEKEND AND EARLY NEXT WEEK.
THE NEXT LONGWAVE TROF WILL SWING ONTO THE WEST COAST LATE
WEDNESDAY. FLOW WILL BACK TO THE SOUTHWEST OVER THE INTERMOUNTAIN
WEST IN ADVANCE OF THIS FEATURE. LATEST MEDIUM RANGE GUIDANCE DIFFER
SOME ON THE TIMING...WITH THE ECMWF THE SLOWEST AND COLDEST. GIVEN
TIMING UNCERTAINTY...DID BEGIN TO INTRODUCE PRECIPITATION CHANCES AS
EARLY AS WEDNESDAY NIGHT AND THURSDAY. HOWEVER...IF THE CURRENT
TRENDS CONTINUE WOULD SUSPECT THAT THIS MAY END UP BEING A BIT EARLY
AND THAT THE BEST CHANCES FOR PRECIPITATION WOULD HOLD OFF UNTIL
THURSDAY NIGHT AND FRIDAY. THE LATEST ECMWF WOULD BE COLD ENOUGH TO
SUPPORT SNOW FRIDAY NIGHT/EARLY SATURDAY. ALTHOUGH STILL TOO FAR OUT
TO FEEL MUCH CONFIDENCE...WILL NEED TO KEEP AN EYE ON THIS SYSTEM
OVER THE COMING DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1218 AM MDT FRI SEP 27 2013
MOIST NORTHEAST WINDS ACROSS THE PLAINS WILL RESULT IN IFR/MVFR
CIGS DEVELOPING FIRST AT KCYS AND THEN SPREADING INTO THE NEBRASKA
PANHANDLE. A COLD FRONT ASSOCIATED WITH AN UPPER LEVEL SYSTEM WILL
MOVE OVER THE SITES FROM LATE MORNING THROUGH THE AFTERNOON WITH
GUSTY NORTHWEST WINDS BEHIND IT. WINDS COULD OCCASIONALLY GUST TO
35 MPH FROM LATE AFTERNOON THROUGH THE EVENING. SCATTERED SHOWERS
WILL ALSO BE POSSIBLE BEHIND THE FRONT. SKIES WILL BEGIN TO CLEAR
BY LATE IN THE TAF PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 415 AM MDT FRI SEP 27 2013
WIDESPREAD SHOWERS WILL OCCUR ACROSS THE REGION THROUGH THIS
EVENING AS AN UPPER LEVEL SYSTEM MOVES OVERHEAD. TEMPERATURES WILL
RISE BY THIS WEEKEND AND INTO EARLY NEXT WEEK AND DRIER AIR WILL
MOVE INTO THE AREA...CAUSING MINIMUM AFTERNOON HUMIDITIES TO DROP
INTO THE 15-20 PERCENT RANGE BY SUNDAY AND MONDAY. WEST TO SOUTHWEST
WINDS WILL BE QUITE BREEZY ESPECIALLY OVER SOUTHEAST WYOMING ON
SUNDAY AND MONDAY WITH OCCASIONAL GUSTS TO 30-40 MPH. THUS...AN
ELEVATED FIRE WEATHER THREAT WILL EXIST WHERE FUELS STILL SUPPORT
FIRE GROWTH.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...HAHN
AVIATION...FINCH
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1246 AM CDT SUN SEP 29 2013
.DISCUSSION...
730 PM CDT
THE FORECAST HAD BEEN UPDATED TO SLOW THE EASTWARD PROGRESS OF
POPS AND TO DIMINISH THEM SOME...THOUGH STILL THINK MOST AREAS WILL
SEE AT LEAST SOME LIGHT RAIN TONIGHT. ALSO DIMINISHED THE TIMING OF
THE WINDOW OF SLIGHT CHANCE OF THUNDER.
THE GOES WATER VAPOR LOOP EARLY THIS EVE DEPICTS THE WELL-
DEVELOPED AUTUMN UPPER LOW LIFTING NORTHEAST OVER WESTERN QUEBEC.
A DEEP BUT NARROW-IN-WIDTH MOIST PLUME EXTENDS FROM TX THROUGH WI
ASSOCIATED WITH THIS. THE 00Z DVN RAOB INDICATED 1.66 IN OF
PWAT...WHICH LIKELY REFLECTS THE UPPER MAGNITUDE AGAIN THAT IS IN
AN EVEN NARROWER AXIS. THERE IS A DISJOINT IN BEST DYNAMICS AND
MOISTURE TRANSPORT/MAGNITUDES WITH THIS SYSTEM OVER THE IMMEDIATE
REGION NOW AND THAT IS LEADING TO MAINLY LIGHT PRECIP COVERAGE
AND INTENSITY...AND EXPECT THIS TO CONTINUE THROUGH 9-11 PM OR SO.
THE BEST UPPER DIFLUENCE IS CURRENTLY OVER WI AND NORTHWARD WHERE
BETTER SHOWER COVERAGE EXISTS...WHILE ANOTHER SHEARED WAVE AND
FOCUSED RIGHT ENTRANCE REGION OF THE UPPER JET IS MOVING NORTHEAST
FROM MO. HAVE BEGUN TO SEE AN UPTICK IN PRECIP WITH THIS FEATURE
ACROSS PARTS OF WEST CENTRAL IL. THE SURFACE FRONT ITSELF IS
LOCATED FROM MADISON WI TO NEAR GALESBURG AND MOVING SLOWLY
EAST...WITH POST FRONTAL FORCING /F-GEN AND SOME ELEVATED
INSTABILITY/ ALLOWING FOR SHOWERS EVEN BEHIND THIS.
AS THE SHEARED WAVE FROM MO TRANSLATES NORTHEAST AND IN TANDEM
WITH A MORE PRONOUN ED LLJ/MOISTURE TRANSPORT...DO ANTICIPATE THE
INCREASE IN SHOWER COVERAGE THAT HAS BEEN ADVERTISED TO MOVE
NORTHEAST. IT LOOKS TO MAINLY BE CONFINED TO EAST OF IL HIGHWAY
47...AND IT IS POSSIBLE IT ENDS UP EVEN BEING FURTHER EAST. THIS
SOMEWHAT MORE STEADIER RAIN/SHOWER ACTIVITY THAT IS FORECAST SHOULD
BE FAIRLY NARROW...SO TRIED TO TIME THAT FOCUS FOR THE HIGHEST
/CATEGORICAL/ POPS. THE NORTH AMERICAN RAPID REFRESH ENSEMBLE
SYSTEM /NARRE-TL/ REALLY HAS A GOOD HANDLE ON WHAT IS HAPPENING
AND WHAT IS EXPECTED TO UNFOLD...AND DOES SHOW A VERY NARROW AXIS
OF HIGHER POPS. BEFORE THAT...MAINLY SOME SPOTTY LIGHT RAIN OR
EVEN DRIZZLE IMMEDIATE AHEAD OF THE FRONT IS FAVORED. ALSO BEHIND
THE FRONT EXPECT THAT SHOWER ACTIVITY SHOULD CONTINUE ALONG THE
MID- LEVEL BAROCLINIC ZONE AND POTENTIALLY INCREASE IN COVERAGE AS
THIS FURTHER TIGHTENS WITH THE UPPER JET RIDGING PARALLEL TO IT.
SO KEEP LIKELY POPS AN HOUR OR TWO BEHIND THE FRONT BUT MENTION
MAINLY LIGHT INTENSITY. OVERALL NONE OF THIS POINTS TOWARD GREAT
THUNDER CHANCES AND HAVE DIMINISHED COVERAGE AND TIMING. NO
LIGHTNING STRIKES SEEN ANYWHERE NEAR THE AREA THE PAST SEVERAL
HOURS.
TEMPERATURE TRENDS LOOK GOOD AND HAVE JUST ADJUSTED/NUDGED TO NEAR
TERM FRONTAL POSITION.
MTF
//PREV DISCUSSION...
254 PM CDT
MAIN CONCERNS TODAY REVOLVE AROUND TIMING PRECIPITATION ASSOCIATED
WITH A COLD FRONT SWEEPING ACROSS THE REGION THIS EVENING.
THIS EVENING AND TONIGHT...
A COLD FRONT SPANS FROM THE ARROWHEAD OF MINNESOTA SOUTH INTO
EASTERN IOWA THIS AFTERNOON WITH PRECIP GENERALLY OCCURRING ALONG
AND JUST AHEAD OF THIS SYSTEM. LIGHTNING ACTIVITY WAS CONFINED
MAINLY TO MISSOURI...BUT HAS REALLY DISSIPATED OVER THE PAST FEW
HOURS. LATEST RAP GUIDANCE DOES INDICATE POTENTIALLY A LITTLE MORE
ROBUST INSTABILITY THAN PREVIOUSLY THOUGHT THOUGH...AND ACCAS OVER THE
AREA THIS MORNING WOULD ALSO SUGGEST THE PRESENCE OF SOME MID LEVEL
INSTABILITY...SO WILL MAINTAIN AT LEAST A SLIGHT CHANCE MENTION FOR
THUNDERSTORMS TODAY THOUGH MAINLY EXPECT RAIN WITH A FEW EMBEDDED
MODERATE SHOWERS. WHILE THERMODYNAMICALLY UNIMPRESSIVE...DYNAMIC
FORCING THIS EVENT CONTINUES TO LEAD TO HIGH CONFIDENCE IN THE
ENTIRE CWA SEEING WETTING RAINS THIS EVENING. WATER VAPOR IMAGERY
SHOWS A WELL DEFINED NEGATIVELY TILTED VORT MAX LIFTING ACROSS THE
UPPER MIDWEST WITH DEEP MOISTURE EXTENDING SOUTH ALONG THE FRONT.
PWATS COULD BE PUSHING 2 INCHES ALONG THE FRONT AS IT SWEEPS ACROSS
THE REGION TONIGHT. WHILE THE BEST UPPER LEVEL FORCING LIES NORTH OF
THE AREA...STILL EXPECT DECENT HEIGHT FALLS TO SPREAD OVER NORTHERN
ILLINOIS...ESPECIALLY LATE THIS EVENING. NAM/GFS INDICATE COUPLED
JET WITH THE BEST AREA OF DIVERGENCE ALOFT MOVING DIRECTLY OVERHEAD
THIS EVENING. THESE COUPLED WITH THE STRONG LOW LEVEL CONVERGENCE
ALONG THE FRONT SHOULD LEAD TO A DEEP VERTICAL RESPONSE...WITH
ACTIVITY ALONG THE FRONT INCREASING IN COVERAGE/INTENSITY LATE THIS
EVENING AS THE FRONT MOVES ACROSS THE CENTRAL AND EASTERN PORTIONS
OF THE CWA.
SUNDAY THROUGH TUESDAY...
FLAT RIDGING WILL BUILD OVER THE LOCAL AREA THROUGH THIS PERIOD WITH
THE MAIN JET STREAM SETTING UP FROM THE PACIFIC NORTHWEST INTO THE
NORTHERN GREAT LAKES...RESULTING IN DRY WEATHER WITH PRECIP CHANCES
STAYING NORTH OF THE AREA. AT THE SURFACE...HIGH PRESSURE WILL BUILD
IN BEHIND THE DEPARTING COLD FRONT SUNDAY. NORTH/NORTHEAST WINDS
SUNDAY WILL KEEP CONDITIONS QUITE A BIT COOLER NEAR THE LAKE FRONT
SUNDAY...LIKELY IN THE MID 60S...BUT TEMPERATURES FARTHER INLAND
SHOULD BE ABLE TO RISE INTO THE LOW TO MID 70S. CLEAR SKIES AND CALM
WINDS UNDER THE RIDGE AXIS SUNDAY NIGHT WILL ALLOW TEMPERATURES TO
EFFECTIVELY RADIATE WITH OVERNIGHT LOWS EXPECTED IN THE LOW TO MID
40S OUTSIDE OF URBAN HEAT ISLAND OF CHICAGO...WHICH IS EXPECTED TO
STAY PROPPED INTO THE MID 50S. WOULDNT BE SURPRISED IF SOME OF THE
TYPICAL COLD SPOTS DIP INTO THE 30S. WILL HAVE TO KEEP AN EYE ON FOG
SUNDAY NIGHT...BUT FOR NOW GUIDANCE SUGGESTS THAT DEW POINTS MAY BE
TOO DRY FOR WIDESPREAD FOG DEVELOP. WITH RECENT RAINFALL
THOUGH...NOT CONFIDENT THAT MODELS ARE HANDLING LOW LEVEL MOISTURE
VERY WELL. WILL INCLUDE MENTION FOR PATCHY FOG OUTSIDE THE METRO
AREA.
WITH THE RIDGE AXIS GRADUALLY SHIFTING EAST OF THE AREA
ON MONDAY...RETURN FLOW WILL LEAD TO A WARMING TREND WITH MID TO
UPPER 70S MONDAY...AND 80S POSSIBLE AGAIN BY TUESDAY. GFS/EMCWF BOTH
SHOW THERMAL RIDGE LEANING OVER THE REGION TUESDAY WITH H85 TEMPS A
LITTLE WARMER THAN TODAY IN THE 16-18C RANGE...THOUGH IF RECENT
MODEL PERFORMANCE IS ANY INDICATOR...THIS MAY BE A BIT TOO WARM.
EVEN TAKING A CONSERVATIVE APPROACH...GUIDANCE APPEARS TO BE A BIT
ON THE COOL SIDE SO WILL MAINTAIN THE WARMER FORECAST OF LOW TO MID
80S.
WEDNESDAY THROUGH SATURDAY...
MODELS IN DECENT AGREEMENT THROUGH WEDNESDAY...WITH THE DEVELOPMENT
OF A DEEP TROUGH OVER THE WEST COAST WEDNESDAY NIGHT...THEN BEGIN TO
DIVERGE WITH TIMING/STRENGTH INTO THE WEEKEND. THE UPPER TROUGH IS
EXPECTED TO PROGRESS EAST ACROSS THE ROCKIES...WITH SURFACE LOW
DEVELOPING OVER THE PLAINS AND A WARM FRONT LIFTING NORTH ACROSS THE
LOCAL AREA. TIMING IS THE MAIN ISSUE. THE GFS IS FASTEST...FOLLOWED
BY THE ECMWF AND THEN THE GFS ENSEMBLE MEAN. A SPAGHETTI PLOT OF
GEFS MEMBERS SHOWING SIGNIFICANT SPREAD BY FRIDAY EVENING...WITH THE
MOST PROGRESSIVE MEMBER SHOWING THE TROUGH AXIS NEARING THE
MISSISSIPPI VALLEY BY FRIDAY EVENING...WHILE SLOWEST MEMBERS HAVE A
DEEPER CLOSED LOW STILL OVER THE INTERMOUNTAIN WEST. ALL THIS BOILS
DOWN TO VERY LOW CONFIDENCE IN THE EXTENDED...THUS MAINTAINED A
BLENDED MODEL SOLUTION IN THE EXTENDED FORECAST...UNTIL DETAILS
START TO BECOME MORE CLEAR.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* RAIN WITH PERIODIC IFR TO START TAF CYCLE
* WIND SHIFT TO NORTHEAST WITH LAKE BREEZE SUNDAY AFTERNOON
IZZI
//DISCUSSION...UPDATED 06Z...
WELL ADVERTISED FRONTAL BAND OF RAIN WITH SOME EMBEDDED HEAVIER
ELEMENTS IS PROGRESSING ACROSS THE REGION. GENERALLY MVFR
CIGS/VSBY THOUGH SOME BRIEF PERIODS OF IFR EXPECTED WITH THE
HEAVIER RAIN. RAIN SHOULD END IN THE NEXT COUPLE HOURS WITH A
RAPID TRANSITION TO VFR AND CLEAR SKIES. NORTHWEST WINDS MOSTLY
LESS THAN 10 KT WILL SHIFT TO NORTHEAST OFF THE LAKE SUNDAY
AFTERNOON BEFORE GOING LIGHT/VARIABLE SUNDAY EVENING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE IN TIMING OF WIND SHIFT TO NE SUN PM
* HIGH CONFIDENCE IN ALL OTHER ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH WEDNESDAY...VFR.
THURSDAY AND FRIDAY...CHANCE SHRA/TSRA.
MDB
&&
.MARINE...
220 PM CDT
HIGH PRESSURE IS OVER NEW ENGLAND WHILE A LOW IS OVER NORTHERN
MINNESOTA/SOUTHWEST ONTARIO. WINDS HAVE STRUGGLED TO STRENGTHEN
OVER THE LAKE TODAY...BUT ARE FINALLY STARTING TO PICK UP. WILL
KEEP THE SMALL CRAFT ADVISORY GOING AND END IT AT 7PM TONIGHT AS
PLANNED. THE HIGH SLOWLY SHIFTS OFF THE NE ATLANTIC COAST WHILE THE
LOW REACHES HUDSON BAY TOMORROW. GUIDANCE IS STILL SUGGESTING WINDS
WILL PICK UP TO 30KT THIS EVENING OVER THE NORTH HALF TO THE LAKE.
IN ADDITION...SOUNDINGS STILL INDICATE THAT GALE FORCE GUSTS LIE
JUST 200 FT ABOVE THE SURFACE. WILL KEEP OCNL GALE FORCE GUSTS GOING
THROUGH 03Z AND HIGHER VESSELS WILL PROBABLY ENCOUNTER MORE THAN
JUST OCNL GALE FORCE GUSTS.
THE LOWS COLD FRONT SWEEPS OVER THE LAKE LATE THIS EVENING WITH NW
WINDS 15-20 KT BEHIND IT. A WEAK SURFACE RIDGE MOVES OVER THE LAKE
TOMORROW AND WINDS QUICKLY DIMINISH. THE HIGH PUSHES EAST WITH
SOUTH WINDS EXPECTED ACROSS THE LAKE MONDAY AND TUESDAY. ANOTHER
LOW PASSES OVER THE SOUTHERN CANADIAN PRAIRIES EARLY NEXT WEEK...AND
EXPECTING THE PRESSURE GRADIENT TO TIGHTEN OVER THE NORTHERN HALF OF
THE LAKE. THEREFORE...HAVE 30KT WINDS OVER THE NORTHERN HALF OF THE
LAKE MONDAY NIGHT AND TUESDAY. WINDS TURN WEST AS THE LOW PUSHES
EAST AND ANOTHER WEAK SURFACE RIDGE SETS UP OVER THE LAKE.
LATE NEXT WEEK STILL LOOKS INTERESTING WITH A LARGE LOW CROSSING THE
PLAINS AND PASSING OVER LAKE SUPERIOR. MODEL TIMING IS NOT
CONSISTENT BETWEEN THE MODELS AND MODEL RUNS. THAT BEING SAID
GUIDANCE IS STILL SUGGESTING STRONG SOUTH WINDS LATE NEXT WEEK AHEAD
OF THE LOW.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
556 AM EDT SUN SEP 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 531 AM EDT SUN SEP 29 2013
08Z WV IMAGERY AND RUC ANALYSIS SHOW A PROMINENT SHORTWAVE TROUGH
MOVING THROUGH THE UPPER GREAT LAKES. THIS SHORTWAVE HAS PUSHED A
SFC COLD FRONT EAST OF UPPER MI EARLY THIS MORNING. LATEST RADAR
IMAGERY SHOWS THAT LAST OF SHRA ASSOC WITH FRONT HAS PUSHED EAST OF
THE FCST AREA. GUSTY WESTERLY WINDS AT OR ABOVE 30 KT OVER THE
PORTAGE CANAL AND CENTRAL/ERN LAKE SUPERIOR IN THE WAKE OF THE COLD
FRONT SHOULD DIE DOWN QUICKLY IN THE NEXT FEW HOURS AS THE PRES
GRADIENT SLACKENS WITH THE HIGH PRES RDG BUILDING IN FM THE
WEST.
TODAY...MODELS IN AGREEMENT SHOWING SHORTWAVE TROUGH LIFTING INTO
NORTHERN ONTARIO AND REACHING JAMES BAY THIS AFTERNOON.
SUBSIDENCE/DRYING IN THE WAKE OF THE COLD FRONT HAS RESULTED IN
CLEAR SKIES ACROSS THE FCST AREA EARLY THIS MORNING. HOWEVER...THE
850 MB THERMAL TROUGH SHOULD SUPPORT THE DEVELOPMENT OF SCT-BKN
STRATOCU CLOUDS OVR THE CNTRL AND EASTERN FCST AREA BY LATE MORNING
INTO EARLY AFTERNOON. MIXING TO 850 MB RESULTS IN MAX TEMPS IN THE
MID TO UPPER 60S MOST LOCATIONS.
TONIGHT...CLEAR SKIES AND LIGHT WINDS ESPECIALLY INTO THE EARLY
OVERNIGHT HOURS SHOULD ALLOW FOR MIN TEMPS TO DIP INTO THE LOWER TO
MID 40S OVER THE INTERIOR CENTRAL AND EAST WHILE SOUTHERLY DOWNSLOPE
WINDS AND ASSOC MIXING WILL KEEP TEMPS CLOSER TO 50F ALONG THE LAKE
SUPERIOR SHORE. LEFT IN PATCHY FOG OVER THE INTERIOR EAST HALF AS
LIGHT SOUTHERLY UPSLOPE FLOW FROM LAKE MI COULD CONTRIBUTE ADDED
MOISTENING FOR SOME FOG DEVELOPMENT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 531 AM EDT SUN SEP 29 2013
UPCOMING WEEK FEATURES A NEGATIVE PACIFIC AND NORTH AMERICAN /PNA/
TELECONNECTION PATTERN WITH BROAD ENERGETIC TROUGHING GULF OF ALASKA
INTO PACIFIC NORTHWEST EARLY THIS WEEK EVENTUALLY TRANSLATING INTO A
STRONG TROUGH INTO THE CNTRL CONUS MID TO LATE WEEK. AS TROUGH MOVES
TO CNTRL CONUS...LOW LEVEL CYCLOGENESIS DEVELOPS FROM CNTRL PLAINS
TO THE UPPER MISSISSIPPI RIVER VALLEY ON THURSDAY. SFC LOW AND A
COLD FRONT SLIDES ACROSS UPPER GREAT LAKES ON FRIDAY THOUGH IT IS
PRETTY UNCERTAIN HOW STRONG OF SYSTEM WILL OCCUR. MUCH COOLER AIR
DROPS ACROSS UPPER LAKES IN WAKE OF THE LOW LATER FRIDAY INTO
SATURDAY. AIRMASS LOOKS CERTAINTY COLD ENOUGH TO RESULT IN SOME LK
EFFECT RAIN...BUT PROBABLY JUST STAYS WARM ENOUGH TO KEEP MIXED
PRECIPITATION OUT OF THE PICTURE...AT LEAST FOR NOW.
AHEAD OF THE DEVELOPING TROUGHING ALOFT AND EVENTUALLY AT THE
SFC...WARM AIR ADVECTION ALOFT AND DIVERGENCE ALOFT WILL SPREAD
VEILS OF MID AND HIGH CLOUDS ACROSS NORTHERN PLAINS AND UPPER LAKES
EARLY THIS WEEK. LOW-LEVELS TOO DRY TO ADD ANY RAIN SHOWERS DESPITE
THE WARM AIR ADVECTION. WITH A LOWER SUN ANGLE NOW BECOMING A
FACTOR...CLOUDS WILL CUT INTO EXPECTED MAX TEMPS SOME BUT WILL
STILL SEE TEMPS 10-15 DEGREES ABOVE NORMAL WITH READINGS TOPPING
OUT IN THE LOW TO MID 70S. BOTH DAYS MAY BE ON THE BREEZY SIDE AS
WELL...WITH BEST SHOT OF SEEING 30+ MPH GUSTS ON MONDAY AS LOW-LEVEL
JET SLIDES ACROSS AREA. HIGHER CLOUDS WILL DAMPEN DEEPER MIXING
POTENTIAL AND WILL LIKELY KEEP HUMIDITY VALUES FROM BOTTOMING OUT
TOO MUCH...BUT STILL COULD SEE INTERIOR WEST CWA DROP TO 35 PCT
BOTH MONDAY AND TUESDAY AFTN. IF TRENDS HOLD UP COULD SEE NEED FOR
A WILDFIRE POTENTIAL STATEMENT OR AT LEAST A MENTION IN HAZARDOUS
WEATHER OUTLOOK. LEAD SFC TROUGH CROSSES THE REGION LATE TUESDAY
NIGHT INTO WEDNESDAY. STILL TOO DRY FOR ANY RAIN...BUT SHOULD SEE
YET ANOTHER SURGE OF MID CLOUDS AND WILL SEE TEMPS COOL 5-10F
COMPARED TO MONDAY AND TUESDAY. WESTERLY WINDS RESULT IN THE MOST
NOTEABLE COOLING OVER THE KEWEENAW. HUMIDITY VALUES ACTUALLY COULD
BE LOWER ON WEDNESDAY AS DWPNTS DROP FURTHER.
MAIN WEATHER FOCUS FOR THE WEEK WILL BE LATE THIS WEEK AND INTO NEXT
WEEKEND AS DEEP TROUGH AFFECTS THE GREAT LAKES. UNCERTAINTY ABOUNDS.
MODELS CONTINUE TO STRUGGLE IN HOW QUICKLY TO BRING INITIAL
LOW-LEVEL TROUGHING AND THE RESULTANT SURGE OF WARM AIR ADVECTION
AND UPPER DIVERGENCE GENERATED SHOWERS INTO THE UPPER LAKES. LATEST
GFS SHOWING A QUICKER TREND IN BRINGING QPF ACROSS MOST OF CWA BY
12Z THURSDAY THAN PREVIOUS THREE RUNS DID. ECMWF WHICH HAS REALLY
BEEN ALL OVER THE PLACE WITH ITS TIMING HAS JOINED GFS IN SHOWING
QUICKER EASTWARD TREND. GEM-NH IS GENERALLY CONSISTENT WITH PREVIOUS
RUNS IN KEEPING MOST OF THE QPF WEST OF CWA BY 12Z THURSDAY AND ONLY
SLOWLY BRINGING IT ACROSS AS MAJORITY OF DIVERGENCE ALOFT HELPS TO
FOCUS CONCENTRATED AREA OF RAIN OVR MINNESOTA INTO NW ONTARIO ALONG
AND NORTH OF COOLER SIDE OF DEVELOPING SFC-H85 LOWS IN ENHANCED FGEN
AREA. GIVEN UNCERTAINTY AND INCONSISTENCIES BTWN THE GFS...ECMWF AND
GEM-NH HAVE STAYED CLOSE TO CONSENSUS HIGHER CHANCE POPS THURSDAY
INTO FRIDAY. PROBABLY WILL BE ONE OR TWO PERIODS OF GREATER RAIN
CHANCES...BUT DETAILS ARE FAR FM CERTAIN. ELEVATED INSTABILITY WITH
SI/S BLO 0C LED TO ADDING TSRA OVER SCNTRL ON THURSDAY IN WHAT
SHOULD BE THE WARMER SECTOR OF THE CYCLONE. FRONTAL BOUNDARY RAINS
MOVE THROUGH THURSDAY NIGHT OR FRIDAY. MAIN STICKING POINT IS JUST
HOW WRAPPED UP WILL SFC LOW TREND AS IT MOVES THROUGH...MAINLY
LEADING TO RAIN COVERAGE ISSUES WITH POTENTIAL DRY SLOT. AT THIS
POINT...APPEARS THAT UPPER LAKES WOULD BE ON COOLER/WETTER SIDE OF
THE LOW WITH SOME POTENTIAL FOR HEAVIER RAIN WITH PWATS OF 1.5
INCHES OR 200 PCT OF NORMAL INTERACTING WITH LOW-LEVEL FGEN AND
UPSLOPE FLOW OFF LK SUPERIOR.
THOUGH DETAILS OF HOW WE GET THERE ARE UNCLEAR...IT EVENTUALLY TURNS
MUCH COOLER LATER FRIDAY INTO SATURDAY AS THE LOW SLOWLY MOVES AWAY
FROM REGION AS UPPER TROUGH DEEPENS OVER GREAT LAKES. H85 TEMPS TO
AT LEAST -4C SEEM LIKE GOOD BET...LEADING TO PLENTY OF LK EFFECT
CLOUDS /LK SFC TEMPS AROUND +12C ON AVERAGE/ AND PROBABLY SOME LK
EFFECT SHOWERS FRIDAY NIGHT INTO SATURDAY MORNING IF THERE IS ENOUGH
SYNOPTIC MOISTURE/CYCLONIC FLOW LINGERING DURING THIS TIME. THE
MOISTURE WILL ALSO FACTOR IN ON WHETHER THE FIRST SNOWFLAKES OF THE
YEAR WILL FLY OVER THE CWA. RIGHT NOW WILL KEEP THE SNOW OUT OF THE
FORECAST AS LATEST RUNS ARE MORE PROGRESSIVE WITH THE LOW AND DRY
OUT THE H85-H7 LAYER CONSIDERABLY. IN THE FOR WHAT IT IS WORTH
DEPARTMENT...TWO CLOSEST SLU CIPS ANALOGS TURNED UP EVENTS FROM LATE
SEPTEMBER AND MID OCTOBER THAT PRODUCED OVER AN INCH OF RAIN ACROSS
PARTS OF CWA WITH SOME SNOW AS THOSE SYSTEMS DEPARTED. WE SHALL SEE
ON THIS ONE. CERTAINLY WILL BE A CHILLY START TO NEXT WEEKEND WITH
THE HIGHER TERRAIN OF THE NORTH STAYING IN THE 40S AS A GUSTY NW WIND
ONLY ADDS TO THE CHILL.
COOLER PATTERN DOES NOT LOOK TO PERSIST THOUGH AS BOTH GFS/ECMWF
INDICATE WARMER TEMPS RETURNING IN SOME SHAPE OR FORM DAYS 7-10.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 135 AM EDT SUN SEP 29 2013
MVFR CONDITIONS AT KCMX SHOULD IMPROVE TO VFR SHORTLY AFT 06Z AS
DRIER AIR WORKS IN FROM THE WEST. VFR CONDITIONS WILL CONTINUE
THROUGH THE PERIOD AT KIWD AND KSAW. SOME LLWS IS EXPECTED SUN NIGHT
AT KIWD AS A LOW-LVL JET MAX NOSES IN FROM THE WEST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 531 AM EDT SUN SEP 29 2013
THERE COULD BE A BRIEF PD OF GALE FORCE GUSTS ALONG AND EAST OF THE
KEWEENAW PENINSULA EARLY THIS MORNING DUE TO FAVORED WESTERLY
CONVERGENT FLOW IN THE WAKE OF THE COLD FRONT. HIGH PRESSURE WILL
THEN BUILD IN TODAY AND QUICKLY DECREASE THE WINDS ACROSS THE
LAKE. THIS HIGH WILL SHIFT SOUTHEAST LATE MONDAY...AS A LOW PRESSURE
SYSTEM MOVES ACROSS CENTRAL CANADA. THIS WILL RESULT IN A BRIEF
INCREASE IN SOUTHERLY WINDS OVER LAKE SUPERIOR LATE MONDAY AND INTO
TUE MORNING WITH A FEW GUSTS REACHING 25 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...07/VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
539 AM EDT SUN SEP 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 531 AM EDT SUN SEP 29 2013
08Z WV IMAGERY AND RUC ANALYSIS SHOW A PROMINENT SHORTWAVE TROUGH
MOVING THROUGH THE UPPER GREAT LAKES. THIS SHORTWAVE HAS PUSHED A
SFC COLD FRONT EAST OF UPPER MI EARLY THIS MORNING. LATEST RADAR
IMAGERY SHOWS THAT LAST OF SHRA ASSOC WITH FRONT HAS PUSHED EAST OF
THE FCST AREA. GUSTY WESTERLY WINDS AT OR ABOVE 30 KT OVER THE
PORTAGE CANAL AND CENTRAL/ERN LAKE SUPERIOR IN THE WAKE OF THE COLD
FRONT SHOULD DIE DOWN QUICKLY IN THE NEXT FEW HOURS AS THE PRES
GRADIENT SLACKENS WITH THE HIGH PRES RDG BUILDING IN FM THE
WEST.
TODAY...MODELS IN AGREEMENT SHOWING SHORTWAVE TROUGH LIFTING INTO
NORTHERN ONTARIO AND REACHING JAMES BAY THIS AFTERNOON.
SUBSIDENCE/DRYING IN THE WAKE OF THE COLD FRONT HAS RESULTED IN
CLEAR SKIES ACROSS THE FCST AREA EARLY THIS MORNING. HOWEVER...THE
850 MB THERMAL TROUGH SHOULD SUPPORT THE DEVELOPMENT OF SCT-BKN
STRATOCU CLOUDS OVR THE CNTRL AND EASTERN FCST AREA BY LATE MORNING
INTO EARLY AFTERNOON. MIXING TO 850 MB RESULTS IN MAX TEMPS IN THE
MID TO UPPER 60S MOST LOCATIONS.
TONIGHT...CLEAR SKIES AND LIGHT WINDS ESPECIALLY INTO THE EARLY
OVERNIGHT HOURS SHOULD ALLOW FOR MIN TEMPS TO DIP INTO THE LOWER TO
MID 40S OVER THE INTERIOR CENTRAL AND EAST WHILE SOUTHERLY DOWNSLOPE
WINDS AND ASSOC MIXING WILL KEEP TEMPS CLOSER TO 50F ALONG THE LAKE
SUPERIOR SHORE. LEFT IN PATCHY FOG OVER THE INTERIOR EAST HALF AS
LIGHT SOUTHERLY UPSLOPE FLOW FROM LAKE MI COULD CONTRIBUTE ADDED
MOISTENING FOR SOME FOG DEVELOPMENT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 531 AM EDT SUN SEP 29 2013
UPCOMING WEEK FEATURES A NEGATIVE PACIFIC AND NORTH AMERICAN /PNA/
TELECONNECTION PATTERN WITH BROAD ENERGETIC TROUGHING GULF OF ALASKA
INTO PACIFIC NORTHWEST EARLY THIS WEEK EVENTUALLY TRANSLATING INTO A
STRONG TROUGH INTO THE CNTRL CONUS MID TO LATE WEEK. AS TROUGH MOVES
TO CNTRL CONUS...LOW LEVEL CYCLOGENESIS DEVELOPS FROM CNTRL PLAINS
TO THE UPPER MISSISSIPPI RIVER VALLEY ON THURSDAY. SFC LOW AND A
COLD FRONT SLIDES ACROSS UPPER GREAT LAKES ON FRIDAY THOUGH IT IS
PRETTY UNCERTAIN HOW STRONG OF SYSTEM WILL OCCUR. MUCH COOLER AIR
DROPS ACROSS UPPER LAKES IN WAKE OF THE LOW LATER FRIDAY INTO
SATURDAY. AIRMASS LOOKS CERTAINTY COLD ENOUGH TO RESULT IN SOME LK
EFFECT RAIN...BUT PROBABLY JUST STAYS WARM ENOUGH TO KEEP MIXED
PRECIPITATION OUT OF THE PICTURE...AT LEAST FOR NOW.
AHEAD OF THE DEVELOPING TROUGHING ALOFT AND EVENTUALLY AT THE
SFC...WARM AIR ADVECTION ALOFT AND DIVERGENCE ALOFT WILL SPREAD
VEILS OF MID AND HIGH CLOUDS ACROSS NORTHERN PLAINS AND UPPER LAKES
EARLY THIS WEEK. LOW-LEVELS TOO DRY TO ADD ANY RAIN SHOWERS DESPITE
THE WARM AIR ADVECTION. WITH A LOWER SUN ANGLE NOW BECOMING A
FACTOR...CLOUDS WILL CUT INTO EXPECTED MAX TEMPS SOME BUT WILL
STILL SEE TEMPS 10-15 DEGREES ABOVE NORMAL WITH READINGS TOPPING
OUT IN THE LOW TO MID 70S. BOTH DAYS MAY BE ON THE BREEZY SIDE AS
WELL...WITH BEST SHOT OF SEEING 30+ MPH GUSTS ON MONDAY AS LOW-LEVEL
JET SLIDES ACROSS AREA. HIGHER CLOUDS WILL DAMPEN DEEPER MIXING
POTENTIAL AND WILL LIKELY KEEP HUMIDITY VALUES FROM BOTTOMING OUT
TOO MUCH...SO FIRE CONCERNS SHOULD BE MITIGATED. LEAD SFC TROUGH
CROSSES THE REGION LATE TUESDAY NIGHT INTO WEDNESDAY. STILL TOO DRY
FOR ANY RAIN...BUT SHOULD SEE YET ANOTHER SURGE OF MID CLOUDS AND
WILL SEE TEMPS COOL 5-10F COMPARED TO MONDAY AND TUESDAY. WESTERLY
WINDS RESULT IN THE MOST NOTEABLE COOLING OVER THE KEWEENAW.
MAIN WEATHER FOCUS FOR THE WEEK WILL BE LATE THIS WEEK AND INTO NEXT
WEEKEND AS DEEP TROUGH AFFECTS THE GREAT LAKES. UNCERTAINTY ABOUNDS.
MODELS CONTINUE TO STRUGGLE IN HOW QUICKLY TO BRING INITIAL
LOW-LEVEL TROUGHING AND THE RESULTANT SURGE OF WARM AIR ADVECTION
AND UPPER DIVERGENCE GENERATED SHOWERS INTO THE UPPER LAKES. LATEST
GFS SHOWING A QUICKER TREND IN BRINGING QPF ACROSS MOST OF CWA BY
12Z THURSDAY THAN PREVIOUS THREE RUNS DID. ECMWF WHICH HAS REALLY
BEEN ALL OVER THE PLACE WITH ITS TIMING HAS JOINED GFS IN SHOWING
QUICKER EASTWARD TREND. GEM-NH IS GENERALLY CONSISTENT WITH PREVIOUS
RUNS IN KEEPING MOST OF THE QPF WEST OF CWA BY 12Z THURSDAY AND ONLY
SLOWLY BRINGING IT ACROSS AS MAJORITY OF DIVERGENCE ALOFT HELPS TO
FOCUS CONCENTRATED AREA OF RAIN OVR MINNESOTA INTO NW ONTARIO ALONG
AND NORTH OF COOLER SIDE OF DEVELOPING SFC-H85 LOWS IN ENHANCED FGEN
AREA. GIVEN UNCERTAINTY AND INCONSISTENCIES BTWN THE GFS...ECMWF AND
GEM-NH HAVE STAYED CLOSE TO CONSENSUS HIGHER CHANCE POPS THURSDAY
INTO FRIDAY. PROBABLY WILL BE ONE OR TWO PERIODS OF GREATER RAIN
CHANCES...BUT DETAILS ARE FAR FM CERTAIN. ELEVATED INSTABILITY WITH
SI/S BLO 0C LED TO ADDING TSRA OVER SCNTRL ON THURSDAY IN WHAT
SHOULD BE THE WARMER SECTOR OF THE CYCLONE. FRONTAL BOUNDARY RAINS
MOVE THROUGH THURSDAY NIGHT OR FRIDAY. MAIN STICKING POINT IS JUST
HOW WRAPPED UP WILL SFC LOW TREND AS IT MOVES THROUGH...MAINLY
LEADING TO RAIN COVERAGE ISSUES WITH POTENTIAL DRY SLOT. AT THIS
POINT...APPEARS THAT UPPER LAKES WOULD BE ON COOLER/WETTER SIDE OF
THE LOW WITH SOME POTENTIAL FOR HEAVIER RAIN WITH PWATS OF 1.5
INCHES OR 200 PCT OF NORMAL INTERACTING WITH LOW-LEVEL FGEN AND
UPSLOPE FLOW OFF LK SUPERIOR.
THOUGH DETAILS OF HOW WE GET THERE ARE UNCLEAR...IT EVENTUALLY TURNS
MUCH COOLER LATER FRIDAY INTO SATURDAY AS THE LOW SLOWLY MOVES AWAY
FROM REGION AS UPPER TROUGH DEEPENS OVER GREAT LAKES. H85 TEMPS TO
AT LEAST -4C SEEM LIKE GOOD BET...LEADING TO PLENTY OF LK EFFECT
CLOUDS /LK SFC TEMPS AROUND +12C ON AVERAGE/ AND PROBABLY SOME LK
EFFECT SHOWERS FRIDAY NIGHT INTO SATURDAY MORNING IF THERE IS ENOUGH
SYNOPTIC MOISTURE/CYCLONIC FLOW LINGERING DURING THIS TIME. THE
MOISTURE WILL ALSO FACTOR IN ON WHETHER THE FIRST SNOWFLAKES OF THE
YEAR WILL FLY OVER THE CWA. RIGHT NOW WILL KEEP THE SNOW OUT OF THE
FORECAST AS LATEST RUNS ARE MORE PROGRESSIVE WITH THE LOW AND DRY
OUT THE H85-H7 LAYER CONSIDERABLY. IN THE FOR WHAT IT IS WORTH
DEPARTMENT...TWO CLOSEST SLU CIPS ANALOGS TURNED UP EVENTS FROM LATE
SEPTEMBER AND MID OCTOBER THAT PRODUCED OVER AN INCH OF RAIN ACROSS
PARTS OF CWA WITH SOME SNOW AS THOSE SYSTEMS DEPARTED. WE SHALL SEE
ON THIS ONE. CERTAINLY WILL BE A CHILLY START TO NEXT WEEKEND WITH
THE HIGHER TERRAIN OF THE NORTH STAYING IN THE 40S AS A GUSTY NW WIND
ONLY ADDS TO THE CHILL.
COOLER PATTERN DOES NOT LOOK TO PERSIST THOUGH AS BOTH GFS/ECMWF
INDICATE WARMER TEMPS RETURNING IN SOME SHAPE OR FORM DAYS 7-10.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 135 AM EDT SUN SEP 29 2013
MVFR CONDITIONS AT KCMX SHOULD IMPROVE TO VFR SHORTLY AFT 06Z AS
DRIER AIR WORKS IN FROM THE WEST. VFR CONDITIONS WILL CONTINUE THROUGH
THE PERIOD AT KIWD AND KSAW. SOME LLWS IS EXPECTED SUN NIGHT AT KIWD
AS A LOW-LVL JET MAX NOSES IN FROM THE WEST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 531 AM EDT SUN SEP 29 2013
THERE COULD BE A BRIEF PD OF GALE FORCE GUSTS ALONG AND EAST OF THE
KEWEENAW PENINSULA EARLY THIS MORNING DUE TO FAVORED WESTERLY
CONVERGENT FLOW IN THE WAKE OF THE COLD FRONT. HIGH PRESSURE WILL
THEN BUILD IN TODAY AND QUICKLY DECREASE THE WINDS ACROSS THE
LAKE. THIS HIGH WILL SHIFT SOUTHEAST LATE MONDAY...AS A LOW PRESSURE
SYSTEM MOVES ACROSS CENTRAL CANADA. THIS WILL RESULT IN A BRIEF
INCREASE IN SOUTHERLY WINDS OVER LAKE SUPERIOR LATE MONDAY AND INTO
TUE MORNING WITH A FEW GUSTS REACHING 25 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...07/VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
148 AM EDT SUN SEP 29 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 412 PM EDT SAT SEEP 28 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A PROMINENT SHORTWAVE TROUGH
FROM ERN NORTH DAKOTA INTO SW MN. AN AREA OF RAIN ALONG AND BEHIND
THE SFC COLD FRONT FROM NE MN THROUGH WRN WI WAS ADVANCING STEADILY
TOWARD UPPER MI. THE COLD FRONT WAS DEFINED BY A VERY NARROW HEAVIER
N-S RAIN BAND TO NEAR HYR AT 1930Z.
TONIGHT...FCST ONSET OF PCPN WAS DELAYED SLIGHTLY COMPARED TO THE
PREVIOUS FCSTS...PER RADAR TRENDS AND SHORT TERM MODELS. OTHERWISE...
THE COMBINATION OF MODERATE TO STRONG 700-300 MB QVECTOR
CONV...AROUND 100M 5H HEIGHT FALLS WITH TROUGH...STRONG 850-700MB
FGEN AND RIGHT ENTRANCE REGION FORCING FROM A 120 KNOT 250-300 MB
JET...AND GOOD MOISTURE AVAILABILITY WITH PWAT VALUES AT OR ABOVE 1.6
INCHES WILL SUSTAIN THE RAIN BAND AS IT MOVES THROUGH THE CWA
TONIGHT. THE SPEED OF THE FRONT MAY LIMIT OVERALL QPF AMOUNTS TO
0.20-0.35 INCH WITH LESSER AMOUNTS IN LOW LEVEL SRLY DOWNSLOPE FLOW
LOCATIONS NEAR LAKE SUPERIOR. THE FRONT AND POST-FRONTAL PCPN WILL
EXIT THE ERN CWA SHORTLY AFTER 06Z SUN WITH GOOD SUBSIDENCE/CLEARING
EXPECTED IN THE WAKE OF THE FRONT LATE TONIGHT.
SUNDAY...THE SHORTWAVE TROUGH WILL CONTINUE TO LIFT INTO NORTHERN
ONTARIO REACHING JAMES BAY BY SUN AFTERNOON. THOUGH SUBSIDENCE BEHIND
THE WAVE SHOULD CLEAR OUT MOST OF THE CLOUDS BY SUNRISE ON
SUNDAY...850-750 MB THERMAL TROUGH SUPPORT SCT-BKN STRATOCU CLOUDS
DEVELOPING OVR CNTRL AND EAST. MIXING TO 850 MB RESULTS IN MAX TEMPS
IN THE MID TO UPPERR 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 412 PM EDT SAT SEP 28 2013
STARTING 00Z MON...THE TROUGH/COLD FRONT THAT WILL MOVE THROUGH
TONIGHT WILL BE WELL E OF THE CWA...AS WILL ALL ASSOCIATED PRECIP.
MORE ZONAL UPPER LEVEL FLOW WILL BE PRESENT OVER THE REGION...WITH
UPPER TROUGHING OVER THE NW CONUS. THROUGH WED...ZONAL FLOW LOOKS TO
REMAIN THE DOMINANT UPPER PATTERN OVER THE CWA...WITH SEVERAL
DISTURBANCES MOVING ACROSS CANADA BUT STAYING FAR ENOUGH N OF THE
CWA TO RULE OUT SIGNIFICANT PRECIP.
WITH A WEAK SFC TROUGH/COLD FRONT BUILDING TO OUR W MON AND MON
NIGHT...THEN MOVING THROUGH THE CWA LATE TUE AND TUE NIGHT...WINDS
WILL INCREASE OUT OF THE SW AHEAD OF THE TROUGH...THEN TURN W TO WNW
LAT TUE THROUGH WED BEHIND THE TROUGH. THIS LEADS TO 850MB TEMPS
INCREASING TO AROUND 15C BY 00Z TUE /AN INCREASE OF AROUND 9C FROM
SUN/...AND POSSIBLY WARMING A BIT MORE THROUGH MON NIGHT. WHILE
HIGHS ON SUN LOOK TO BE IN THE 60S...HIGHS ON MON ARE EXPECTED TO BE
IN THE 70S TO NEAR 80 IN SOME SPOTS OVER WRN UPPER MI. LOWS ON MON
NIGHT SHOULD THEN BE IN THE MID 40S IN THE COLDEST SPOTS OVER ERN
UPPER MI TO THE MID 50S NEAR LAKE SUPERIOR AND W. LOOKS LIKE ANY
PRECIP WITH FROPA ON TUE/TUE NIGHT WILL STAY N OF LAKE SUPERIOR WITH
THE BETTER UPPER LEVEL FORCING. TUE SHOULD SEE SIMILAR TEMPS TO
MON...OR POSSIBLY A COUPLE OF DEGREES WARMER GIVEN THE WARM LOW
TEMPS MON NIGHT.
COOLER AIR ARRIVES TUE NIGHT...BUT BREEZY WINDS BEHIND THE COLD FRONT
WILL HELP KEEP LOW TEMPS FROM FALLING TOO LOW. WITH 850MB TEMPS OF
7-8C ON WED...TEMPS WILL BE COOLER THAN TUE WITH HIGHS PRIMARILY IN
THE 60S TO AROUND 70.
THINGS BECOME MUCH MORE UNCLEAR THU THROUGH NEXT SAT AS MODELS
CONTINUE TO SHOW SOME SORT OF UPPER LEVEL ENERGY MOVING INTO THE
CENTRAL CONUS. WHILE MODELS DO AGREE THAT THE ENERGY WILL BE
STRONGER /AND EITHER A DEEP TROUGH OR A CLOSED LOW/...THEY HAVE POOR
RUN TO RUN CONTINUITY AND POOR MODEL TO MODEL AGREEMENT. THIS LENDS
VERY LITTLE CONFIDENCE IN DETAILS FOR THIS PORTION OF THE FORECAST.
FOR THIS REASON...WILL LOAD A GENERAL CONSENSUS OF MODEL
GUIDANCE...AND AM FINE WITH HIGHER END POPS AS ALL MODEL SCENARIOS
WOULD LEAD TO PRECIP AT ONE TIME OR ANOTHER. IT IS WORTH POINTING
OUT THAT ALL MODELS AT THIS TIME ARE WARM ENOUGH TO NOT WARRANT
TALKING ABOUT MIXED PRECIP...SO IT SEEMS THAT THERE WILL NOT BE ANY
WINTER QUITE YET.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 135 AM EDT SUN SEP 29 2013
MVFR CONDITIONS AT KCMX SHOULD IMPROVE TO VFR SHORTLY AFT 06Z AS
DRIER AIR WORKS IN FROM THE WEST. VFR CONDITIONS WILL CONTINUE THROUGH
THE PERIOD AT KIWD AND KSAW. SOME LLWS IS EXPECTED SUN NIGHT AT KIWD
AS A LOW-LVL JET MAX NOSES IN FROM THE WEST.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 PM EDT SAT SEP 28 2013
A FRONT WILL SLIDE EAST ACROSS LAKE SUPERIOR THIS EVENING AND
DURING THE EARLY OVERNIGHT HOURS...SHIFTING THE WINDS TO THE WEST.
THERE COULD BE A FEW HOUR PERIOD OF GALE FORCE GUSTS OVER THE
WESTERN LAKE THIS EVENING BEHIND THE FRONT. HIGH PRESSURE
WILL THEN BUILD IN FOR SUNDAY AND QUICKLY DECREASE THE WINDS ACROSS
THE LAKE. THIS HIGH WILL SHIFT SOUTHEAST LATE MONDAY...AS A LOW
PRESSURE SYSTEM MOVES ACROSS CENTRAL CANADA. THIS WILL RESULT IN A
BRIEF INCREASE IN SOUTHERLY WINDS OVER LAKE SUPERIOR MONDAY NIGHT
WITH A FEW GUSTS REACHING 25 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07/VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1230 AM CDT SUN SEP 29 2013
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION.
&&
.DISCUSSION...02Z SURFACE ANALYSIS PLACES A COLD FRONT FROM
MILWAUKEE TO SAINT LOUIS...AND WESTERN ARKANSAS. KLZK WSR-88D
RADAR TRENDS OVER THE PAST COUPLE OF HOURS HAVE SHOWN CONSIDERABLE
WEAKENING OF THE CONVECTIVE RAIN SHOWERS AND PERHAPS AN EMBEDDED
THUNDERSTORM OR TWO OVER CENTRAL ARKANSAS AS THEY BEGIN TO
APPROACH EAST AND NORTHEAST ARKANSAS LATE THIS EVENING AND
ENCOUNTER A DRIER AND MORE STABLE AIRMASS OVER THE MID SOUTH. 00Z
UPPER AIR SOUNDINGS AT JACKSON MS AND NASHVILLE INDICATE A
SUBSTANTIAL 800-700 MB CAPPING INVERSION PRESENT ACROSS THE
REMAINDER OF THE LOWER MISSISSIPPI VALLEY. LATEST 3KM HRRR AND 00Z
WRF INDICATE MOST IF NOT ALL OF THE RAIN SHOWERS WILL STRUGGLE TO
GET PAST THE MISSISSIPPI RIVER BEFORE 12Z. /7 AM CDT/ WILL MAKE
FURTHER ADJUSTMENTS TO OVERNIGHT RAIN CHANCES TO REDUCE THUNDER
MENTION AND KEEP MOST OF THE RAIN CHANCES ALONG/WEST OF THE
MISSISSIPPI RIVER. WILL MAKE ANY OTHER ADJUSTMENTS TO GRIDS AS
NEEDED TO ACCOUNT FOR LATEST TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.DISCUSSION...
A COLD FRONT CURRENTLY STRETCHES FROM NEAR KIRKSVILLE MISSOURI TO
NEAR FORT SMITH ARKANSAS. A BAND OF SHOWERS HAS FORMED ALONG THE
FRONT FROM SOUTHWEST MISSOURI TO EASTERN OKLAHOMA INTO NORTHWEST
ARKANSAS. THIS FRONT WILL MOVE INTO THE MIDSOUTH LATE TONIGHT.
CURRENTLY ACROSS THE MIDSOUTH...TEMPERATURES HAVE RISEN INTO THE
80S THANKS TO AN UPPER RIDGE THAT HAS BEEN POSITIONED ALONG THE
GULF COAST FOR THE LAST COUPLE OF DAYS. THE RIDGE WILL RETREAT
EASTWARD THIS EVENING. EXPECT BAND OF SHOWERS TO MOVE INTO
RANDOLPH/LAWRENCE COUNTIES BETWEEN 9 PM AND MIDNIGHT. THE BAND OF
SHOWERS WILL SLOWLY PUSH SOUTH AND EAST AFTER MIDNIGHT. EXPECT
BAND TO BE ROUGHLY LOCATED ALONG THE MISSISSIPPI RIVER BETWEEN
6 AM-8 AM. CAN/T RULE OUT A FEW EMBEDDED THUNDERSTORMS DEVELOPING
IN THE BAND SO WILL KEEP MENTION OF THUNDER. LOWS WILL BE IN THE
60S.
SUNDAY...COLD FRONT IS STILL EXPECTED TO STALL OUT ACROSS THE
MIDSOUTH LIKELY IN THE AREA FROM JACKSON TENNESSEE TO CLARKSDALE
MISSISSIPPI. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP
ALONG AND AHEAD OF THE FRONT. EXPECT HIGHS TO BE COOLER WITH
READINGS IN THE MID 70S TO LOWER 80S.
FRONT WILL EVENTUALLY PUSH BACK NORTHWARD AS A WARM FRONT ON
MONDAY. AS A RESULT...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
CONTINUE SUNDAY NIGHT AND MONDAY. BEST CHANCES WILL OCCUR ALONG
THE FRONT.
STILL HARD TO SAY WHAT EXACTLY WILL HAPPEN DURING THE MONDAY NIGHT
THROUGH WEDNESDAY TIME FRAME. UPPER RIDGE WILL BUILD BACK OVER THE
AREA BUT CHANCES FOR RAIN WILL DEPEND ON IF A DISTURBANCE GETS
TRAPPED UNDERNEATH RIDGE. TOO MANY IF/S RIGHT NOW...SO WILL
CONTINUE WITH FORECAST AS IS. DO EXPECT TEMPERATURES TO RETURN TO
ABOVE NORMAL WITH THE RIDGE BUILDING BACK INTO THE REGION.
00Z MODELS PUSHED TIMING OF NEXT FRONT BACK 24 HOURS BUT 12Z ECMWF
HAS PUSHED TIMING BACK TO THURSDAY NIGHT INTO FRIDAY. 12Z GFS
REMAINS 24 HOURS SLOWER. WILL CONTINUE WITH SMALL POPS DURING THE
THURSDAY NIGHT THROUGH SATURDAY TIME FRAME FOR NOW. TEMPERATURES
WILL COOL DOWN BEHIND NEXT FRONT.
KRM
&&
.AVIATION...
06Z TAF CYCLE
RAIN TONIGHT LOOKS EVEN LESS LIKELY AS SHOWERS ARE MOVING INTO A
DRIER AIRMASS. SCALED BACK RAIN ON STATION TO VCSH
TONIGHT...BRINGING IN SHRA AS WE BEGIN TO DESTABILIZE TOMORROW.
A WEAKENING COLD FRONT WILL BECOME DIFFICULT TO IDENTIFY OVER THE
NEXT 24 HOURS AS IT MOVES ACROSS THE MIDSOUTH...BECOMING MASKED BY
OUTFLOW FROM SHOWERS AND THUNDERSTORMS. AS A RESULT THUS WINDS
WILL BE HIGHLY VARIABLE TOMORROW INTO TOMORROW NIGHT.
HOWEVER...WIND SPEEDS SHOULD REMAIN FAIRLY WEAK...LESS THAN 8 KTS.
SHOWERS RESULTING IN MVFR CIGS AND VIS WILL LIKELY PREVAIL AT ALL
SITES EXCEPT TUP FOR MOST OF THE DAY TOMORROW. CIGS SHOULD LOWER
EVEN FURTHER AFTER SUNSET...POSSIBLE TO IFR LEVELS...BUT FEEL LIKE
LOW MVFR WILL PREVAIL. SHOWERS WILL LIKELY LINGER AT MKL...MEM AND
TUP AS WELL.
JDS/AC3
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 67 81 67 85 / 40 20 10 10
MKL 62 80 61 84 / 40 20 10 10
JBR 62 80 64 83 / 30 20 10 10
TUP 64 83 64 85 / 20 20 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1056 PM PDT Sat Sep 28 2013
.SYNOPSIS...
Tonight will be wet and windy with the passage of a strong cold
front. Another stronger cold front will bring more wind and rain
to the region Sunday night into Monday. High mountain snow is
expected Monday into Tuesday. The wild weather will begin to
settle down on Wednesday. The nicest weather of the week will
occur Thursday and Friday, but temperatures will remain below
average through the end of the week.
&&
.DISCUSSION...
The cold front is making its way through western WA early this
evening with widespread moderate rainfall and pockets of heavy
rainfall being reported along the front. Numerous reports of heavy
rainfall of over 2 inches have been reported west of the Cascades
so far with this system. The cold front is expected to push across
eastern WA and into the ID Panhandle overnight. The HRRR model
seems to have a good handle with the timing of the front and the
forecast is reflective of this latest model solution. We are
expecting the front to begin to push east of the Cascade Mountains
after 1100 PM tonight. A strong moist warm sector ahead of the
cold front combined with strong frontal dynamics is expected to
produce moderate to heavy rainfall just out ahead of the cold
front. Heaviest rainfall rates are anticipated closer to the
leading edge of the front. I increased precipitation chances and
rainfall amounts for tonight, primarily across the eastern half of
the forecast area. 12 HR rainfall totals through 500 AM this
morning are expected to generally be between a quarter and a half
an inch across extreme eastern WA with the Panhandle seeing these
totals between a half and three-quarters.
The cold front is expected to have passed southeast of the region
around the early morning hours on Sunday. A chance of showers will
be possible across the ID Panhandle behind the front due to
orographics across this area. The Cascade Crest will also continue
to see showers with the higher elevations above 5500 feet likely
switching over to snow. Locations in between these areas will
likely dry out at least into the morning hours on Sunday.
Winds will continue to be gusty ahead of and especially with
frontal passage. Some observations across the Moses Lake Area, on
the Waterville Plateau and in the Okanogan Valley have reported
gusts of between 40 and 55 mph. Although these winds have not been
quite as windy further east across the Upper Columbia Basin and
into the Spokane/Coeur d`Alene Area and across the Palouse, I do
think we will see a better chance for some stronger winds with
cold front passage. Some locations may see a brief period of
reaching advisory criteria winds where we have canceled the
advisory earlier, but I think these stronger winds will be
relatively brief as the cold front moves over the area. Thus, I do
not anticipate making any updates to the Wind Advisory at this
time. Winds should weaken a bit behind the front as strongest
winds aloft will shift eastward with the cold front. /SVH
&&
.AVIATION...
06Z TAFS: A cold front will sweep across eastern WA and into the ID
Panhandle over the next 6 hours. The front is currently passing
through KMWH at 06Z tonight and will continue east with time and is
expected to pass through KGEG, KSFF, KCOE, KPUW and KLWS between 07Z
and 11Z tonight. This front will result in some heavier rainfall
across the region with a better chance for cigs/vis down into MVFR/IFR
category. Low stratus is expected to develop across extreme eastern
WA and into the Panhandle behind the cold front for at least a few
hours. Winds will shift from the south-southeast to a southwesterly
orientation and become more gusty with cold front passage. A second,
similar system, will pass through the region Sunday evening into
Sunday night with more rain and gusty winds expected. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 47 57 45 56 44 56 / 100 50 80 30 20 50
Coeur d`Alene 48 55 44 53 43 55 / 100 70 100 50 30 50
Pullman 48 56 46 56 43 57 / 100 80 90 30 10 30
Lewiston 54 62 50 63 46 64 / 70 70 80 20 10 20
Colville 50 58 45 57 43 57 / 100 60 100 50 30 50
Sandpoint 49 55 43 49 41 53 / 100 80 100 70 70 50
Kellogg 47 52 43 49 40 52 / 100 90 100 90 70 50
Moses Lake 50 66 47 65 45 64 / 40 20 50 10 10 20
Wenatchee 47 62 47 63 45 62 / 40 30 60 10 10 20
Omak 47 64 44 63 40 62 / 70 40 70 10 10 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch through late Sunday night for Northern Panhandle.
WA...Flood Watch through late Sunday night for East Slopes Northern
Cascades.
Wind Advisory until 2 AM PDT Sunday for Moses Lake Area-Upper
Columbia Basin-Waterville Plateau.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1025 AM EDT SUN SEP 29 2013
.UPDATE...
ISSUED AT 1025 AM EDT SUN SEP 29 2013
13Z SFC ANALYSIS SHOWS HIGH PRESSURE MOVING OFF TO THE EAST IN THE
FACE OF AN INBOUND...BUT SHEARING...COLD FRONT. THIS FRONT HAS A
SOLID BAND OF SHOWERS ALONG IT THROUGH THE WESTERN PARTS OF THE STATE
UP INTO SOUTHEAST INDIANA...CURRENTLY. THE MODELS DIFFER ON THE
EXTENT THAT THIS PCPN BAND CAN HOLD TOGETHER INTO EAST KENTUCKY LATE
THIS AFTERNOON. THE HRRR AND 06Z NAM12 ARE RATHER BULLISH...THOUGH
BOTH QUITE DIMINISHED FROM ITS CURRENT STATE. HOWEVER...THE RAP13 AND
00Z ECMWF KEEP EAST KENTUCKY DRY THROUGH THIS EVENING. THE 06Z GFS IS
PROBABLY THE MOST AGGRESSIVE AND WET MODEL WITH THIS DIEING BOUNDARY
AND SEEMS WAY OVERDONE. TAKING ALL TOGETHER...AM UNCOMFORTABLE WITH
TRYING TO GO DRY THROUGH 12Z ACROSS THE AREA AS THE FRONT DIES OUT
OVERHEAD OR JUST TO THE WEST. ACCORDINGLY...HAVE REINTRODUCED
ISOLATED SHOWERS INTO THE FORECAST FOR THE CWA FROM LATER THIS
AFTERNOON AND THROUGH THE NIGHT. THE BEST CHANCES WILL BE OVER OUR
WESTERNMOST COUNTIES...BUT EVEN THERE MOST PLACES WILL LIKELY STAY
DRY. OTHERWISE...THE FORECAST IS ON TRACK SO HAVE MADE ONLY SMALL
CHANGES TO THE SKY COVER...T...AND TD GRIDS THROUGH THE REST OF THE
DAY BASED ON THE LATEST OBS...TRENDS...AND CONSSHORT GUIDANCE. THESE
UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH THE
ISSUANCE OF A FRESH SET OF ZONES.
UPDATE ISSUED AT 637 AM EDT SUN SEP 29 2013
ASIDE FROM INGESTING OBSERVATION DATA INTO THE FORECAST GRIDS TO
ESTABLISH NEW TRENDS...NO CHANGES WERE MADE TO THE FORECAST.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 316 AM EDT SUN SEP 29 2013
A VERY QUIET FORECAST ON TAP FOR TODAY THROUGH TOMORROW. HIGH
PRESSURE WILL KEEP THE WEATHER OF EASTERN KENTUCKY DRY AND MILD AGAIN
TODAY AND TONIGHT...AS IT MOVES OFF TO THE NORTHEAST. THE FORECAST
MODELS ARE HAVING A VERY DIFFICULT TIME OVERCOMING THE RIDGE OF HIGH
PRESSURE THAT IS CURRENTLY PARKED OVER THE EASTERN THIRD OF THE
CONUS. THE MODELS ALL HAVE A COLD FRONT APPROACHING THE AREA FROM THE
WEST...WITH RAIN SHOWERS FORMING ALONG IT THIS EVENING AND EARLY
TONIGHT ACROSS INDIANA AND CENTRAL KENTUCKY. THE ISSUE IS THAT THESE
SAME MODELS ARE ALL WASHING THE FRONT OUT AND STALLING IT BEFORE IT
HAS A CHANCE TO MOVE ACROSS EASTERN KENTUCKY OVERNIGHT. THE ONLY HINT
OF THE FRONT OVERNIGHT WILL LIKELY BE A DIFFICULT TO DETECT WIND
SHIFT. WITH THAT IN MIND...DECIDED TO GO WITH A RAIN FREE FORECAST
FOR THE OVERNIGHT HOURS...AS THE LACK OF DAYTIME HEATING WILL LIKELY
RENDER THE FRONT UNABLE TO PRODUCE EVEN AN ISOLATED RAIN SHOWER.
HOWEVER...WITH THE REMNANTS OF THE FRONT STILL SHOWING UP IN THE
MODELS ON MONDAY...DID DECIDE TO KEEP IN A SLIGHT CHANCE OF SHOWERS
AS WHAT IS LEFT OF THE BOUNDARY COULD BECOME ACTIVE DURING DAYTIME
HEATING. CONFIDENCE IN THAT SCENARIO IS ALSO LOW CONSIDERING HOW
DIFFUSE THE FRONT APPEARS TO BE IN THE LATEST MODELS.
TEMPERATURES TODAY AND TOMORROW WILL BE RUNNING AT OR SLIGHTLY ABOVE
NORMAL...WITH THE WARMER DAY BEING TODAY...AS EASTERN KENTUCKY WILL
BE EXPERIENCING A SOUTHERLY FLOW PATTERN AND ONLY PARTLY CLOUDY SKIES
FOR THE FIRST HALF OF THE DAY. HIGHS ARE EXPECTED TO BE MOSTLY IN THE
MID 70S TODAY AND IN THE LOW TO MID 70S ON MONDAY. THE RIVER VALLEYS
WILL ALSO LIKELY EXPERIENCE AREAS OF FOG AGAIN TONIGHT...AS WINDS GO
NEAR CALM AND MOISTURE RECOVERY BEGINS TO OCCUR AHEAD OF AN
APPROACHING ALBEIT RAPIDLY DISINTEGRATING COLD FRONT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 316 AM EDT SUN SEP 29 2013
OTHER THAN AN AREA OF LOW PRESSURE OFF THE COAST OF CAPE COD...THE
50H PATTERN IS NEARLY ZONAL ACROSS THE CONUS. THERE IS A SHORT WAVE
TRACKING ACROSS THE CANADIAN PLAINS. HOWEVER ANY EFFECTS OF THIS
SHOULD REMAIN NORTH OF THE BORDER. BY WED AFTERNOON THE PATTERN
BEGINS TO CHANGE WITH HIGH PRESSURE BUILDING OVER THE SERN STATES AND
A TROF SWINGING INTO THE NRN ROCKIES. THIS PATTERN WILL CONTINUE TO
DEVELOP UNTIL BY THU NIGHT A WELL DEVELOPED TROF RESIDES OVER THE
NRN PLAINS WITH THE RIDGE MOVING INTO THE ATLANTIC OFF THE FLA
COAST. AS THE HIGH PRESSURE CONTINUES TO MOVE FURTHER INTO THE
ATLANTIC...THE PLAINS TROF WILL SURGE INTO THE GREAT LAKES UNTIL IT
SITS OVER THE ERN CONUS BY SAT NIGHT WITH RIDGING ACROSS THE
ROCKIES.
AT THE SFC...MON NITE SEES THE REMNANTS OF THE COLD FRONT
DISSIPATING AND WEATHER TURNING DRY. THE HIGH WILL KEEP ERN KY DRY
UNTIL LATE THU NITE WHEN THE SFC REFLECTION OF THE 50H TROF SWINGS
THE NEXT COLD FRONT INTO THE COMMONWEALTH. THIS FRONT APPEARS TO BE
RELATIVELY PROGRESSIVE AND SHOULD BRING SHOWERS FRIDAY AND FRIDAY
NITE WITH A FEW THUNDERSTORMS POSSIBLE FRIDAY AFTERNOON. BY SAT HIGH
PRESSURE WILL ONCE AGAIN BUILD INTO THE OH/TN VALLEY AND RETURN DRY
WEATHER TO THE AREA. HIGH TEMPS WILL REMAIN AROUND 80 UNTIL SAT WHEN
THE COLD FRONT DROPS READINGS INTO THE MID 70S. LOOK FOR THE COOL
TEMPS TO REMAIN THRU THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM EDT SUN SEP 29 2013
BROKEN TO OVERCAST CIGS HAVE BEEN AFFECTING THE TAF SITES SEVERAL
HOURS EARLIER THAN EXPECTED IN THE PREVIOUS FORECAST. NOT EXPECTING
ANY PRECIPITATION AT THE TAF SITES THROUGH THE END OF THE TAF PERIOD.
THE FOG THAT IS IN PLACE SHOULD BE GONE BY 13Z AT MOST LOCATIONS. MID
LEVEL CIGS CONTINUE WITH APPROACHING COLD FRONT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...AR
LONG TERM...DUSTY
AVIATION...DUSTY
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
724 AM EDT SUN SEP 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 531 AM EDT SUN SEP 29 2013
08Z WV IMAGERY AND RUC ANALYSIS SHOW A PROMINENT SHORTWAVE TROUGH
MOVING THROUGH THE UPPER GREAT LAKES. THIS SHORTWAVE HAS PUSHED A
SFC COLD FRONT EAST OF UPPER MI EARLY THIS MORNING. LATEST RADAR
IMAGERY SHOWS THAT LAST OF SHRA ASSOC WITH FRONT HAS PUSHED EAST OF
THE FCST AREA. GUSTY WESTERLY WINDS AT OR ABOVE 30 KT OVER THE
PORTAGE CANAL AND CENTRAL/ERN LAKE SUPERIOR IN THE WAKE OF THE COLD
FRONT SHOULD DIE DOWN QUICKLY IN THE NEXT FEW HOURS AS THE PRES
GRADIENT SLACKENS WITH THE HIGH PRES RDG BUILDING IN FM THE
WEST.
TODAY...MODELS IN AGREEMENT SHOWING SHORTWAVE TROUGH LIFTING INTO
NORTHERN ONTARIO AND REACHING JAMES BAY THIS AFTERNOON.
SUBSIDENCE/DRYING IN THE WAKE OF THE COLD FRONT HAS RESULTED IN
CLEAR SKIES ACROSS THE FCST AREA EARLY THIS MORNING. HOWEVER...THE
850 MB THERMAL TROUGH SHOULD SUPPORT THE DEVELOPMENT OF SCT-BKN
STRATOCU CLOUDS OVR THE CNTRL AND EASTERN FCST AREA BY LATE MORNING
INTO EARLY AFTERNOON. MIXING TO 850 MB RESULTS IN MAX TEMPS IN THE
MID TO UPPER 60S MOST LOCATIONS.
TONIGHT...CLEAR SKIES AND LIGHT WINDS ESPECIALLY INTO THE EARLY
OVERNIGHT HOURS SHOULD ALLOW FOR MIN TEMPS TO DIP INTO THE LOWER TO
MID 40S OVER THE INTERIOR CENTRAL AND EAST WHILE SOUTHERLY DOWNSLOPE
WINDS AND ASSOC MIXING WILL KEEP TEMPS CLOSER TO 50F ALONG THE LAKE
SUPERIOR SHORE. LEFT IN PATCHY FOG OVER THE INTERIOR EAST HALF AS
LIGHT SOUTHERLY UPSLOPE FLOW FROM LAKE MI COULD CONTRIBUTE ADDED
MOISTENING FOR SOME FOG DEVELOPMENT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 531 AM EDT SUN SEP 29 2013
UPCOMING WEEK FEATURES A NEGATIVE PACIFIC AND NORTH AMERICAN /PNA/
TELECONNECTION PATTERN WITH BROAD ENERGETIC TROUGHING GULF OF ALASKA
INTO PACIFIC NORTHWEST EARLY THIS WEEK EVENTUALLY TRANSLATING INTO A
STRONG TROUGH INTO THE CNTRL CONUS MID TO LATE WEEK. AS TROUGH MOVES
TO CNTRL CONUS...LOW LEVEL CYCLOGENESIS DEVELOPS FROM CNTRL PLAINS
TO THE UPPER MISSISSIPPI RIVER VALLEY ON THURSDAY. SFC LOW AND A
COLD FRONT SLIDES ACROSS UPPER GREAT LAKES ON FRIDAY THOUGH IT IS
PRETTY UNCERTAIN HOW STRONG OF SYSTEM WILL OCCUR. MUCH COOLER AIR
DROPS ACROSS UPPER LAKES IN WAKE OF THE LOW LATER FRIDAY INTO
SATURDAY. AIRMASS LOOKS CERTAINTY COLD ENOUGH TO RESULT IN SOME LK
EFFECT RAIN...BUT PROBABLY JUST STAYS WARM ENOUGH TO KEEP MIXED
PRECIPITATION OUT OF THE PICTURE...AT LEAST FOR NOW.
AHEAD OF THE DEVELOPING TROUGHING ALOFT AND EVENTUALLY AT THE
SFC...WARM AIR ADVECTION ALOFT AND DIVERGENCE ALOFT WILL SPREAD
VEILS OF MID AND HIGH CLOUDS ACROSS NORTHERN PLAINS AND UPPER LAKES
EARLY THIS WEEK. LOW-LEVELS TOO DRY TO ADD ANY RAIN SHOWERS DESPITE
THE WARM AIR ADVECTION. WITH A LOWER SUN ANGLE NOW BECOMING A
FACTOR...CLOUDS WILL CUT INTO EXPECTED MAX TEMPS SOME BUT WILL
STILL SEE TEMPS 10-15 DEGREES ABOVE NORMAL WITH READINGS TOPPING
OUT IN THE LOW TO MID 70S. BOTH DAYS MAY BE ON THE BREEZY SIDE AS
WELL...WITH BEST SHOT OF SEEING 30+ MPH GUSTS ON MONDAY AS LOW-LEVEL
JET SLIDES ACROSS AREA. HIGHER CLOUDS WILL DAMPEN DEEPER MIXING
POTENTIAL AND WILL LIKELY KEEP HUMIDITY VALUES FROM BOTTOMING OUT
TOO MUCH...BUT STILL COULD SEE INTERIOR WEST CWA DROP TO 35 PCT
BOTH MONDAY AND TUESDAY AFTN. IF TRENDS HOLD UP COULD SEE NEED FOR
A WILDFIRE POTENTIAL STATEMENT OR AT LEAST A MENTION IN HAZARDOUS
WEATHER OUTLOOK. LEAD SFC TROUGH CROSSES THE REGION LATE TUESDAY
NIGHT INTO WEDNESDAY. STILL TOO DRY FOR ANY RAIN...BUT SHOULD SEE
YET ANOTHER SURGE OF MID CLOUDS AND WILL SEE TEMPS COOL 5-10F
COMPARED TO MONDAY AND TUESDAY. WESTERLY WINDS RESULT IN THE MOST
NOTEABLE COOLING OVER THE KEWEENAW. HUMIDITY VALUES ACTUALLY COULD
BE LOWER ON WEDNESDAY AS DWPNTS DROP FURTHER.
MAIN WEATHER FOCUS FOR THE WEEK WILL BE LATE THIS WEEK AND INTO NEXT
WEEKEND AS DEEP TROUGH AFFECTS THE GREAT LAKES. UNCERTAINTY ABOUNDS.
MODELS CONTINUE TO STRUGGLE IN HOW QUICKLY TO BRING INITIAL
LOW-LEVEL TROUGHING AND THE RESULTANT SURGE OF WARM AIR ADVECTION
AND UPPER DIVERGENCE GENERATED SHOWERS INTO THE UPPER LAKES. LATEST
GFS SHOWING A QUICKER TREND IN BRINGING QPF ACROSS MOST OF CWA BY
12Z THURSDAY THAN PREVIOUS THREE RUNS DID. ECMWF WHICH HAS REALLY
BEEN ALL OVER THE PLACE WITH ITS TIMING HAS JOINED GFS IN SHOWING
QUICKER EASTWARD TREND. GEM-NH IS GENERALLY CONSISTENT WITH PREVIOUS
RUNS IN KEEPING MOST OF THE QPF WEST OF CWA BY 12Z THURSDAY AND ONLY
SLOWLY BRINGING IT ACROSS AS MAJORITY OF DIVERGENCE ALOFT HELPS TO
FOCUS CONCENTRATED AREA OF RAIN OVR MINNESOTA INTO NW ONTARIO ALONG
AND NORTH OF COOLER SIDE OF DEVELOPING SFC-H85 LOWS IN ENHANCED FGEN
AREA. GIVEN UNCERTAINTY AND INCONSISTENCIES BTWN THE GFS...ECMWF AND
GEM-NH HAVE STAYED CLOSE TO CONSENSUS HIGHER CHANCE POPS THURSDAY
INTO FRIDAY. PROBABLY WILL BE ONE OR TWO PERIODS OF GREATER RAIN
CHANCES...BUT DETAILS ARE FAR FM CERTAIN. ELEVATED INSTABILITY WITH
SI/S BLO 0C LED TO ADDING TSRA OVER SCNTRL ON THURSDAY IN WHAT
SHOULD BE THE WARMER SECTOR OF THE CYCLONE. FRONTAL BOUNDARY RAINS
MOVE THROUGH THURSDAY NIGHT OR FRIDAY. MAIN STICKING POINT IS JUST
HOW WRAPPED UP WILL SFC LOW TREND AS IT MOVES THROUGH...MAINLY
LEADING TO RAIN COVERAGE ISSUES WITH POTENTIAL DRY SLOT. AT THIS
POINT...APPEARS THAT UPPER LAKES WOULD BE ON COOLER/WETTER SIDE OF
THE LOW WITH SOME POTENTIAL FOR HEAVIER RAIN WITH PWATS OF 1.5
INCHES OR 200 PCT OF NORMAL INTERACTING WITH LOW-LEVEL FGEN AND
UPSLOPE FLOW OFF LK SUPERIOR.
THOUGH DETAILS OF HOW WE GET THERE ARE UNCLEAR...IT EVENTUALLY TURNS
MUCH COOLER LATER FRIDAY INTO SATURDAY AS THE LOW SLOWLY MOVES AWAY
FROM REGION AS UPPER TROUGH DEEPENS OVER GREAT LAKES. H85 TEMPS TO
AT LEAST -4C SEEM LIKE GOOD BET...LEADING TO PLENTY OF LK EFFECT
CLOUDS /LK SFC TEMPS AROUND +12C ON AVERAGE/ AND PROBABLY SOME LK
EFFECT SHOWERS FRIDAY NIGHT INTO SATURDAY MORNING IF THERE IS ENOUGH
SYNOPTIC MOISTURE/CYCLONIC FLOW LINGERING DURING THIS TIME. THE
MOISTURE WILL ALSO FACTOR IN ON WHETHER THE FIRST SNOWFLAKES OF THE
YEAR WILL FLY OVER THE CWA. RIGHT NOW WILL KEEP THE SNOW OUT OF THE
FORECAST AS LATEST RUNS ARE MORE PROGRESSIVE WITH THE LOW AND DRY
OUT THE H85-H7 LAYER CONSIDERABLY. IN THE FOR WHAT IT IS WORTH
DEPARTMENT...TWO CLOSEST SLU CIPS ANALOGS TURNED UP EVENTS FROM LATE
SEPTEMBER AND MID OCTOBER THAT PRODUCED OVER AN INCH OF RAIN ACROSS
PARTS OF CWA WITH SOME SNOW AS THOSE SYSTEMS DEPARTED. WE SHALL SEE
ON THIS ONE. CERTAINLY WILL BE A CHILLY START TO NEXT WEEKEND WITH
THE HIGHER TERRAIN OF THE NORTH STAYING IN THE 40S AS A GUSTY NW WIND
ONLY ADDS TO THE CHILL.
COOLER PATTERN DOES NOT LOOK TO PERSIST THOUGH AS BOTH GFS/ECMWF
INDICATE WARMER TEMPS RETURNING IN SOME SHAPE OR FORM DAYS 7-10.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 720 AM EDT SUN SEP 29 2013
HIGH PRESSURE OVER THE REGION WILL RESULT IN VFR CONDITIONS AT ALL
TAF SITES. SOME LLWS IS EXPECTED AT KIWD AND KCMX LATE TONIGHT AS A
LOW-LEVEL JET MAX PUSHES IN FM THE WEST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 531 AM EDT SUN SEP 29 2013
THERE COULD BE A BRIEF PD OF GALE FORCE GUSTS ALONG AND EAST OF THE
KEWEENAW PENINSULA EARLY THIS MORNING DUE TO FAVORED WESTERLY
CONVERGENT FLOW IN THE WAKE OF THE COLD FRONT. HIGH PRESSURE WILL
THEN BUILD IN TODAY AND QUICKLY DECREASE THE WINDS ACROSS THE
LAKE. THIS HIGH WILL SHIFT SOUTHEAST LATE MONDAY...AS A LOW PRESSURE
SYSTEM MOVES ACROSS CENTRAL CANADA. THIS WILL RESULT IN A BRIEF
INCREASE IN SOUTHERLY WINDS OVER LAKE SUPERIOR LATE MONDAY AND INTO
TUE MORNING WITH A FEW GUSTS REACHING 25 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1008 AM CDT SUN SEP 29 2013
.UPDATE...
ISSUED AT 1008 AM CDT SUN SEP 29 2013
ONLY MINOR CHANGES TO THIS UPDATE...MAINLY TO INCREASE THE CLOUD
COVER ACROSS THE NORTH. VISIBLE SAT SHOWS WHAT APPEARS TO BE
THICKER CIRRUS MOVING TO THE E/NE. CROSS-SECTIONS USING THE RAP AND
GFS IN FAIR AGREEMENT WITH THE VISIBLE. OTHERWISE WITH SOUTHWEST
FLOW SUSPECT TEMPERATURES ON TRACK FOR MIDDLE TO UPPER 70S MOST AREAS.
UPDATE ISSUED AT 650 AM CDT SUN SEP 29 2013
FORECAST IS IN GOOD SHAPE WITH NO CHANGES NEEDED AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 332 AM CDT SUN SEP 29 2013
CHALLENGES INCLUDE TEMPERATURES AND WIND THROUGH THE PERIOD. WILL
FOLLOW A BLEND OF THE NAM/ECMWF/GEM AS THE LATEST GFS IS TOO FAST
WITH THE FRONTAL PASSAGE MONDAY NIGHT.
FOR TODAY...EXPECT PLENTY OF SUN BETWEEN PERIODS OF HIGH CLOUDS AS
THE REGION REMAINS BETWEEN WEATHER SYSTEMS. MODEL SOUNDINGS SHOW A
7 TO 10 C RISE IN BOUNDARY LAYER TEMPERATURES COMPARED TO YESTERDAY...
RESULTING IN AFTERNOON HIGHS IN THE LOWER TO MID 70S. WITH 25 TO 30
KTS TO MIX TO THE SURFACE...SOUTHERLY WINDS WILL BECOME BREEZY
WITH SOME GUSTS TO 25 MPH.
MONDAY WILL BE SIMILAR TODAY...EXCEPT A BIT WARMER WITH LESS WIND.
HIGHS WILL TOP OUT IN THE MID TO UPPER 70S WITH SOUTH-SOUTHWEST
WIND FROM 10 TO 15 MPH.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 AM CDT SUN SEP 29 2013
A COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA MONDAY NIGHT...
BRINGING A SLIGHT CHANCE OF RAIN SHOWERS ACROSS THE NORTH. BEST
FORCING AND MOISTURE IS NORTH OF THE CANADIAN BORDER...SO NOT
EXPECTING MUCH ACCUMULATION IF ANYTHING DOES DEVELOP. BIGGER
SENSIBLE WEATHER IMPACT WILL BE INCREASING WEST-SOUTHWEST WIND
BEHIND THE FRONT. BOUNDARY LAYER DEEPENS TO NEAR 800 HPA BY
TUESDAY MID-AFTERNOON WITH 35 TO 40 KTS TO MIX TO THE SURFACE.
THIS COULD RESULT IN SUSTAINED WINDS IN EXCESS OF 30 MPH...THUS
REQUIRING A WIND ADVISORY. WAY TOO EARLY TO CONSIDER ISSUANCE...
BUT FOR SURE LOOKS TO BE A WINDY DAY. TEMPERATURES WILL ALSO DROP
BEHIND THE FRONT WITH HIGHS FROM THE MID 60S TO MID 70S.
LONG RANGE MODELS COMING INTO BETTER AGREEMENT WITH A MORE SOUTHERN
SOLN FOR THU-FRI SYSTEM AS 500 TROUGH DIGS A BIT INTO WYOMING AND
UPPER RIDGE TO THE EAST OVER THE GREAT LAKES IS FLATTER. 00Z EURO
CAME IN RESEMBLING THE 18Z SAT AND 00Z SUN GFS IN SHOWING THIS.
AFTER MUCH COORDINATION WENT CLOSER TO THIS SOLN WHICH REQUIRED
SIGNIFICANT CHANGES TO THE ALL BLEND FCST. KEPT SOME LOW SHOWER
CHANCES WEDNESDAY IN SE ND INTO NRN MN AS A WEAK SHORT WAVE MOVES
THRU...THEN LIMITED ANY CHANCE OF SHOWERS TO SOUTHEAST HALF OF THE
FCST AREA THU-THU NIGHT AND THEN DRY FRIDAY AS COLDER AIR MOVES
SOUTH. 00Z EURO HAS 850 MB TEMPS -4 TO -5C IN NE ND/NW MN FRI WITH
HIGH PRESSURE MOVING IN WHICH WOULD TRANSLATE TO A CHILLY FRI
NIGHT WITH WIDESPREAD SUB FREEZING LOWS. GFS NOT AS COLD BUT STILL
A BIT BLO 0C 850 MB TEMPS. LOWERED TEMPS A BIT FROM ALL BLEND TOOL
TO SHOW WIDESPREAD LOW-MID 30S FOR SAT MORNING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 650 AM CDT SUN SEP 29 2013
MOSTLY SUNNY/CLEAR SKIES WILL PERSIST AT ALL TAF SITES THE NEXT 24
HOURS. LIGHT SOUTHERLY WIND WILL INCREASE LATE MORNING WITH GUSTS
UP TO 25 KTS BY MID AFTERNOON. WINDS WILL DECREASE AFTER SUNSET
AND REMAIN NEAR 10 KTS OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...EWENS
SHORT TERM...ROGERS
LONG TERM...ROGERS/RIDDLE
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS JACKSON KY
543 PM EDT SUN SEP 29 2013
.UPDATE...
ISSUED AT 542 PM EDT SUN SEP 29 2013
LATEST RADAR IS SHOWING SOME LIGHT SHOWERS/SPRINKLES MOVING INTO THE
FAR SOUTHWESTERN COUNTIES ABOUT AN HOUR OR SO FASTER THAN WAS
PREVIOUSLY FORECASTED. NOT A BIG CHANGE...BUT WENT AHEAD AND SPED UP
ISOLATED PRECIP ABOUT AN HOUR TO START AT 21Z /NOW/. ALSO LOADED IN
THE LATEST OBSERVATIONAL DATA TO MAKE SURE ONGOING FORECAST WAS
MATCHING UP WITH CURRENT TEMPERATURES AND WINDS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 355 PM EDT SUN SEP 29 2013
19Z SFC ANALYSIS SHOWS THE DYING FRONT SETTLING INTO CENTRAL KENTUCKY
WHILE ITS ASSOCIATED SHOWERS AND WANING. A FEW OF THESE SHOULD BE
ABLE TO MAKE INTO THE WESTERN PARTS OF THE CWA OVER THE NEXT FEW
HOURS ALONG WITH A FEW POP UP SHOWERS FURTHER EAST. PLENTY OF CLOUDS
ARE FOUND THROUGH EAST KENTUCKY OUT AHEAD OF THESE SHOWERS...BUT
TEMPERATURES STILL MANAGED TO MAKE IT INTO THE LOWER AND MID 70S IN
MOST LOCATIONS. MEANWHILE...WITH LIGHT SOUTHWEST WINDS...DEWPOINTS
ARE HOLDING IN THE UPPER 50S AND LOWER 60S.
THE MODELS ARE IN GOOD AGREEMENT ALOFT LIFTING A TROUGH TO THE
NORTHEAST FROM THE GREAT LAKES AND SHEARING IT OUT AS IT MOVES DEEPER
INTO EASTERN CANADA TONIGHT. SOME LEFTOVER ENERGY WILL DRIFT INTO
THE LOWER OHIO VALLEY TONIGHT AND ALSO DIMINISH IN THE FACE OF WEAK
FLOW AT MID LEVELS ON MONDAY AND RISING HEIGHTS THAT NIGHT. GIVEN THE
AGREEMENT IN THE MODELS...HAVE FOLLOWED A GENERAL BLEND FOR WEATHER
DETAILS WITH A STRONGER LEAN THAN NORMAL TOWARD THE NEAR-TERM...HIGHER
RESOLUTION HRRR AND RAP13 MODELS.
SENSIBLE WEATHER WILL FEATURE THE MUDDLED REMNANTS OF THE FRONT AND
ITS DISSIPATING SHOWERS PUSHING INTO THE CWA TONIGHT AND LINGERING
IN THE AREA ON MONDAY. THIS WILL NECESSITATE THE INCLUSION OF
ISOLATED SHOWERS IN THE FORECAST...THOUGH MOST PLACES WILL STAY DRY
AND QPF WILL AVERAGE BELOW A TENTH OF AN INCH WHERE ANY SHOWER MANAGE
TO PASS OVER. WILL KEEP THE TEMPERATURES RATHER MILD TONIGHT AND
MONDAY NIGHT GIVEN THE CLOUDS AND CONTINUED ELEVATED MOISTURE
CONTENT. DID ADD LIGHT FOG IN THE VALLEYS BOTH NIGHTS SHOULD THE
CLOUDS CLEAR ENOUGH TO ALLOW FOR SOME RADIATIONAL COOLING.
AGAIN USED THE CONSSHORT AND ITS BC BROTHER TO JUMP START THE TD AND
WIND GRIDS THROUGH 12Z MONDAY...AND THE CONSALL THEREAFTER. FOR
TEMPERATURES...USED THE OBS DATABASE AS A BASIS FOR THE DIURNAL
CURVE ALONG WITH MODIFIED CONSALL MAX AND MIN TEMPS...ONLY MINOR
TERRAIN ADJUSTMENT TONIGHT AND MONDAY NIGHT. AS FOR POPS...ENDED UP
MOST SIMILAR TO THE MET NUMBERS THROUGH FIRST PART OF THE SHORT
TERM.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 PM EDT SUN SEP 29 2013
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY WITH A ZONAL AND
PROGRESSIVE UPPER LEVEL PATTERN IN PLACE AS THE JET WILL WILL REMAIN
ALONG THE CANADIAN BORDER. MID AND UPPER LEVEL RIDGING FURTHER
DEVELOPS OVER THE SOUTHEAST TUESDAY AND WEDNESDAY. DURING LATE
TUESDAY AND WEDNESDAY...A MID LEVEL WAVE MOVE NORTHWARD OUT OF THE
GULF AND INTO THE OHIO VALLEY REGION. THIS DISTURBANCE COUPLED WITH
AN INCREASE OF MOIST SOUTHERLY FLOW WILL BE THE FOCUS OF SOME PRECIP
CHANCES BY THURSDAY AND FRIDAY. ALSO...THE 12Z RUN OF THE GFS AND 00Z RUN
OF THE EURO SHOW SOME AGREEMENT ON THIS SOLUTION. THEREFORE...BASED
ON THE ALL BLENDS SOLUTION...WILL LIKELY PUT SOME CHANCE POPS IN FOR
THURSDAY. THE INTERESTING PART OF THE FORECAST COMES INTO PLAY BY
FRIDAY AND SATURDAY AS A DEEP TROUGH DEVELOPS OVER THE FRONT RANGE
AND SHIFTS EAST. AT THIS POINT...THE GFS AND EURO ARE ADVERTISING
THE FIRST FALL STRONG COLD FRONT WITH QUITE A COOL SHOT BEHIND THIS
SYSTEM. WILL INTRODUCE CHANCE POPS BY FRIDAY AGAIN BASED ON THE ALL
MODEL BLEND SOLUTION. IN DEALING WITH THE WEEKEND SYSTEM...BASED ON
THE NEW EURO RUN AND COLLABORATION WITH NEIGHBORING OFFICES...WENT
WITH A GOOD CHANCE OF PRECIP ON SATURDAY AND SUNDAY. MODELS AT THIS
POINT ARE IN GOOD AGREEMENT WITH A SIGNIFICANT FRONT MOVING THROUGH
BY NEXT WEEKEND.
WITH SOUTHERLY FLOW THROUGH THE EARLY PART OF THE
EXTENDED...TEMPERATURES WILL BE 3 TO 5 DEGREES ABOVE NORMAL BEFORE
THE COLD FRONT MOVES THROUGH BY SUNDAY RESULTING IN A SIGNIFICANT
COOL DOWN WITH TEMPERATURES 5 TO 10 DEGREES BELOW NORMAL. THIS WILL
RESULT IN THE COOLEST AIR OF THE SEASON SO FAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 230 PM EDT SUN SEP 29 2013
MID LEVEL AND VFR LOWER CLOUDS ACCOMPANY THE FRONT AND ITS DYING
BATCH OF RAIN SHOWERS HEADING TOWARD THE CWA THIS AFTERNOON. HAVE
ADDED A VCSH FOR THESE SHOWERS TO THE TAFS FOR LATE THIS AFTERNOON
AND THROUGH THE EVENING. PATCHY MVFR FOG WILL BE POSSIBLE LATE
TONIGHT BEFORE CLEARING OUT SHORTLY AFTER SUNRISE ON MONDAY. WINDS
WILL BE GENERALLY BETWEEN 5 AND 10 KTS FOR THE REMAINDER OF THIS
AFTERNOON...FROM THE SOUTHWEST...AND LIGHT AND VARIABLE TONIGHT INTO
MONDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
355 PM EDT SUN SEP 29 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 355 PM EDT SUN SEP 29 2013
19Z SFC ANALYSIS SHOWS THE DYING FRONT SETTLING INTO CENTRAL KENTUCKY
WHILE ITS ASSOCIATED SHOWERS AND WANING. A FEW OF THESE SHOULD BE
ABLE TO MAKE INTO THE WESTERN PARTS OF THE CWA OVER THE NEXT FEW
HOURS ALONG WITH A FEW POP UP SHOWERS FURTHER EAST. PLENTY OF CLOUDS
ARE FOUND THROUGH EAST KENTUCKY OUT AHEAD OF THESE SHOWERS...BUT
TEMPERATURES STILL MANAGED TO MAKE IT INTO THE LOWER AND MID 70S IN
MOST LOCATIONS. MEANWHILE...WITH LIGHT SOUTHWEST WINDS...DEWPOINTS
ARE HOLDING IN THE UPPER 50S AND LOWER 60S.
THE MODELS ARE IN GOOD AGREEMENT ALOFT LIFTING A TROUGH TO THE
NORTHEAST FROM THE GREAT LAKES AND SHEARING IT OUT AS IT MOVES DEEPER
INTO EASTERN CANADA TONIGHT. SOME LEFTOVER ENERGY WILL DRIFT INTO
THE LOWER OHIO VALLEY TONIGHT AND ALSO DIMINISH IN THE FACE OF WEAK
FLOW AT MID LEVELS ON MONDAY AND RISING HEIGHTS THAT NIGHT. GIVEN THE
AGREEMENT IN THE MODELS...HAVE FOLLOWED A GENERAL BLEND FOR WEATHER
DETAILS WITH A STRONGER LEAN THAN NORMAL TOWARD THE NEAR-TERM...HIGHER
RESOLUTION HRRR AND RAP13 MODELS.
SENSIBLE WEATHER WILL FEATURE THE MUDDLED REMNANTS OF THE FRONT AND
ITS DISSIPATING SHOWERS PUSHING INTO THE CWA TONIGHT AND LINGERING
IN THE AREA ON MONDAY. THIS WILL NECESSITATE THE INCLUSION OF
ISOLATED SHOWERS IN THE FORECAST...THOUGH MOST PLACES WILL STAY DRY
AND QPF WILL AVERAGE BELOW A TENTH OF AN INCH WHERE ANY SHOWER MANAGE
TO PASS OVER. WILL KEEP THE TEMPERATURES RATHER MILD TONIGHT AND
MONDAY NIGHT GIVEN THE CLOUDS AND CONTINUED ELEVATED MOISTURE
CONTENT. DID ADD LIGHT FOG IN THE VALLEYS BOTH NIGHTS SHOULD THE
CLOUDS CLEAR ENOUGH TO ALLOW FOR SOME RADIATIONAL COOLING.
AGAIN USED THE CONSSHORT AND ITS BC BROTHER TO JUMP START THE TD AND
WIND GRIDS THROUGH 12Z MONDAY...AND THE CONSALL THEREAFTER. FOR
TEMPERATURES...USED THE OBS DATABASE AS A BASIS FOR THE DIURNAL
CURVE ALONG WITH MODIFIED CONSALL MAX AND MIN TEMPS...ONLY MINOR
TERRAIN ADJUSTMENT TONIGHT AND MONDAY NIGHT. AS FOR POPS...ENDED UP
MOST SIMILAR TO THE MET NUMBERS THROUGH FIRST PART OF THE SHORT
TERM.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 PM EDT SUN SEP 29 2013
THE EXTENDED FORECAST PERIOD BEGINS ON TUESDAY WITH A ZONAL AND
PROGRESSIVE UPPER LEVEL PATTERN IN PLACE AS THE JET WILL WILL REMAIN
ALONG THE CANADIAN BORDER. MID AND UPPER LEVEL RIDGING FURTHER
DEVELOPS OVER THE SOUTHEAST TUESDAY AND WEDNESDAY. DURING LATE
TUESDAY AND WEDNESDAY...A MID LEVEL WAVE MOVE NORTHWARD OUT OF THE
GULF AND INTO THE OHIO VALLEY REGION. THIS DISTURBANCE COUPLED WITH
AN INCREASE OF MOIST SOUTHERLY FLOW WILL BE THE FOCUS OF SOME PRECIP
CHANCES BY THURSDAY AND FRIDAY. ALSO...THE 12Z RUN OF THE GFS AND 00Z RUN
OF THE EURO SHOW SOME AGREEMENT ON THIS SOLUTION. THEREFORE...BASED
ON THE ALL BLENDS SOLUTION...WILL LIKELY PUT SOME CHANCE POPS IN FOR
THURSDAY. THE INTERESTING PART OF THE FORECAST COMES INTO PLAY BY
FRIDAY AND SATURDAY AS A DEEP TROUGH DEVELOPS OVER THE FRONT RANGE
AND SHIFTS EAST. AT THIS POINT...THE GFS AND EURO ARE ADVERTISING
THE FIRST FALL STRONG COLD FRONT WITH QUITE A COOL SHOT BEHIND THIS
SYSTEM. WILL INTRODUCE CHANCE POPS BY FRIDAY AGAIN BASED ON THE ALL
MODEL BLEND SOLUTION. IN DEALING WITH THE WEEKEND SYSTEM...BASED ON
THE NEW EURO RUN AND COLLABORATION WITH NEIGHBORING OFFICES...WENT
WITH A GOOD CHANCE OF PRECIP ON SATURDAY AND SUNDAY. MODELS AT THIS
POINT ARE IN GOOD AGREEMENT WITH A SIGNIFICANT FRONT MOVING THROUGH
BY NEXT WEEKEND.
WITH SOUTHERLY FLOW THROUGH THE EARLY PART OF THE
EXTENDED...TEMPERATURES WILL BE 3 TO 5 DEGREES ABOVE NORMAL BEFORE
THE COLD FRONT MOVES THROUGH BY SUNDAY RESULTING IN A SIGNIFICANT
COOL DOWN WITH TEMPERATURES 5 TO 10 DEGREES BELOW NORMAL. THIS WILL
RESULT IN THE COOLEST AIR OF THE SEASON SO FAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 230 PM EDT SUN SEP 29 2013
MID LEVEL AND VFR LOWER CLOUDS ACCOMPANY THE FRONT AND ITS DYING
BATCH OF RAIN SHOWERS HEADING TOWARD THE CWA THIS AFTERNOON. HAVE
ADDED A VCSH FOR THESE SHOWERS TO THE TAFS FOR LATE THIS AFTERNOON
AND THROUGH THE EVENING. PATCHY MVFR FOG WILL BE POSSIBLE LATE
TONIGHT BEFORE CLEARING OUT SHORTLY AFTER SUNRISE ON MONDAY. WINDS
WILL BE GENERALLY BETWEEN 5 AND 10 KTS FOR THE REMAINDER OF THIS
AFTERNOON...FROM THE SOUTHWEST...AND LIGHT AND VARIABLE TONIGHT INTO
MONDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
230 PM EDT SUN SEP 29 2013
.UPDATE...
ISSUED AT 225 PM EDT SUN SEP 29 2013
A BAND OF SHOWERS ASSOCIATED WITH THE DISSIPATING FRONT CONTINUE TO
APPROACH THE CWA FROM THE WEST...BUT THEY ARE DIMINISHING...TOO.
STILL EXPECT THE MINIMAL THREAT TO CROSS INTO OUR AREA LATE THIS
AFTERNOON AND SPREAD SLOWLY EAST THROUGH THE EVENING. EVEN SO...MOST
PLACES WILL STAY DRY AND ANY SPOTS THAT GET A SHOWER WILL SEE
MEASUREMENTS IN ONLY A FEW HUNDREDTHS OF AN INCH...AT WORST. HAVE
UPDATED THE FORECAST TO CONTINUE THIS LINE OF THINKING AND MATCH UP
THE LATEST OBS AND TRENDS FROM THE SKY/T/TD TO THE GRIDS. UPDATES
HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1025 AM EDT SUN SEP 29 2013
13Z SFC ANALYSIS SHOWS HIGH PRESSURE MOVING OFF TO THE EAST IN THE
FACE OF AN INBOUND...BUT SHEARING...COLD FRONT. THIS FRONT HAS A
SOLID BAND OF SHOWERS ALONG IT THROUGH THE WESTERN PARTS OF THE STATE
UP INTO SOUTHEAST INDIANA...CURRENTLY. THE MODELS DIFFER ON THE
EXTENT THAT THIS PCPN BAND CAN HOLD TOGETHER INTO EAST KENTUCKY LATE
THIS AFTERNOON. THE HRRR AND 06Z NAM12 ARE RATHER BULLISH...THOUGH
BOTH QUITE DIMINISHED FROM ITS CURRENT STATE. HOWEVER...THE RAP13 AND
00Z ECMWF KEEP EAST KENTUCKY DRY THROUGH THIS EVENING. THE 06Z GFS IS
PROBABLY THE MOST AGGRESSIVE AND WET MODEL WITH THIS DIEING BOUNDARY
AND SEEMS WAY OVERDONE. TAKING ALL TOGETHER...AM UNCOMFORTABLE WITH
TRYING TO GO DRY THROUGH 12Z ACROSS THE AREA AS THE FRONT DIES OUT
OVERHEAD OR JUST TO THE WEST. ACCORDINGLY...HAVE REINTRODUCED
ISOLATED SHOWERS INTO THE FORECAST FOR THE CWA FROM LATER THIS
AFTERNOON AND THROUGH THE NIGHT. THE BEST CHANCES WILL BE OVER OUR
WESTERNMOST COUNTIES...BUT EVEN THERE MOST PLACES WILL LIKELY STAY
DRY. OTHERWISE...THE FORECAST IS ON TRACK SO HAVE MADE ONLY SMALL
CHANGES TO THE SKY COVER...T...AND TD GRIDS THROUGH THE REST OF THE
DAY BASED ON THE LATEST OBS...TRENDS...AND CONSSHORT GUIDANCE. THESE
UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS ALONG WITH THE
ISSUANCE OF A FRESH SET OF ZONES.
UPDATE ISSUED AT 637 AM EDT SUN SEP 29 2013
ASIDE FROM INGESTING OBSERVATION DATA INTO THE FORECAST GRIDS TO
ESTABLISH NEW TRENDS...NO CHANGES WERE MADE TO THE FORECAST.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 316 AM EDT SUN SEP 29 2013
A VERY QUIET FORECAST ON TAP FOR TODAY THROUGH TOMORROW. HIGH
PRESSURE WILL KEEP THE WEATHER OF EASTERN KENTUCKY DRY AND MILD AGAIN
TODAY AND TONIGHT...AS IT MOVES OFF TO THE NORTHEAST. THE FORECAST
MODELS ARE HAVING A VERY DIFFICULT TIME OVERCOMING THE RIDGE OF HIGH
PRESSURE THAT IS CURRENTLY PARKED OVER THE EASTERN THIRD OF THE
CONUS. THE MODELS ALL HAVE A COLD FRONT APPROACHING THE AREA FROM THE
WEST...WITH RAIN SHOWERS FORMING ALONG IT THIS EVENING AND EARLY
TONIGHT ACROSS INDIANA AND CENTRAL KENTUCKY. THE ISSUE IS THAT THESE
SAME MODELS ARE ALL WASHING THE FRONT OUT AND STALLING IT BEFORE IT
HAS A CHANCE TO MOVE ACROSS EASTERN KENTUCKY OVERNIGHT. THE ONLY HINT
OF THE FRONT OVERNIGHT WILL LIKELY BE A DIFFICULT TO DETECT WIND
SHIFT. WITH THAT IN MIND...DECIDED TO GO WITH A RAIN FREE FORECAST
FOR THE OVERNIGHT HOURS...AS THE LACK OF DAYTIME HEATING WILL LIKELY
RENDER THE FRONT UNABLE TO PRODUCE EVEN AN ISOLATED RAIN SHOWER.
HOWEVER...WITH THE REMNANTS OF THE FRONT STILL SHOWING UP IN THE
MODELS ON MONDAY...DID DECIDE TO KEEP IN A SLIGHT CHANCE OF SHOWERS
AS WHAT IS LEFT OF THE BOUNDARY COULD BECOME ACTIVE DURING DAYTIME
HEATING. CONFIDENCE IN THAT SCENARIO IS ALSO LOW CONSIDERING HOW
DIFFUSE THE FRONT APPEARS TO BE IN THE LATEST MODELS.
TEMPERATURES TODAY AND TOMORROW WILL BE RUNNING AT OR SLIGHTLY ABOVE
NORMAL...WITH THE WARMER DAY BEING TODAY...AS EASTERN KENTUCKY WILL
BE EXPERIENCING A SOUTHERLY FLOW PATTERN AND ONLY PARTLY CLOUDY SKIES
FOR THE FIRST HALF OF THE DAY. HIGHS ARE EXPECTED TO BE MOSTLY IN THE
MID 70S TODAY AND IN THE LOW TO MID 70S ON MONDAY. THE RIVER VALLEYS
WILL ALSO LIKELY EXPERIENCE AREAS OF FOG AGAIN TONIGHT...AS WINDS GO
NEAR CALM AND MOISTURE RECOVERY BEGINS TO OCCUR AHEAD OF AN
APPROACHING ALBEIT RAPIDLY DISINTEGRATING COLD FRONT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 316 AM EDT SUN SEP 29 2013
OTHER THAN AN AREA OF LOW PRESSURE OFF THE COAST OF CAPE COD...THE
50H PATTERN IS NEARLY ZONAL ACROSS THE CONUS. THERE IS A SHORT WAVE
TRACKING ACROSS THE CANADIAN PLAINS. HOWEVER ANY EFFECTS OF THIS
SHOULD REMAIN NORTH OF THE BORDER. BY WED AFTERNOON THE PATTERN
BEGINS TO CHANGE WITH HIGH PRESSURE BUILDING OVER THE SERN STATES AND
A TROF SWINGING INTO THE NRN ROCKIES. THIS PATTERN WILL CONTINUE TO
DEVELOP UNTIL BY THU NIGHT A WELL DEVELOPED TROF RESIDES OVER THE
NRN PLAINS WITH THE RIDGE MOVING INTO THE ATLANTIC OFF THE FLA
COAST. AS THE HIGH PRESSURE CONTINUES TO MOVE FURTHER INTO THE
ATLANTIC...THE PLAINS TROF WILL SURGE INTO THE GREAT LAKES UNTIL IT
SITS OVER THE ERN CONUS BY SAT NIGHT WITH RIDGING ACROSS THE
ROCKIES.
AT THE SFC...MON NITE SEES THE REMNANTS OF THE COLD FRONT
DISSIPATING AND WEATHER TURNING DRY. THE HIGH WILL KEEP ERN KY DRY
UNTIL LATE THU NITE WHEN THE SFC REFLECTION OF THE 50H TROF SWINGS
THE NEXT COLD FRONT INTO THE COMMONWEALTH. THIS FRONT APPEARS TO BE
RELATIVELY PROGRESSIVE AND SHOULD BRING SHOWERS FRIDAY AND FRIDAY
NITE WITH A FEW THUNDERSTORMS POSSIBLE FRIDAY AFTERNOON. BY SAT HIGH
PRESSURE WILL ONCE AGAIN BUILD INTO THE OH/TN VALLEY AND RETURN DRY
WEATHER TO THE AREA. HIGH TEMPS WILL REMAIN AROUND 80 UNTIL SAT WHEN
THE COLD FRONT DROPS READINGS INTO THE MID 70S. LOOK FOR THE COOL
TEMPS TO REMAIN THRU THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 230 PM EDT SUN SEP 29 2013
MID LEVEL AND VFR LOWER CLOUDS ACCOMPANY THE FRONT AND ITS DIEING
BATCH OF RAIN SHOWERS HEADING TOWARD THE CWA THIS AFTERNOON. HAVE
ADDED A VCSH FOR THESE SHOWERS TO THE TAFS FOR LATE THIS AFTERNOON
AND THROUGH THE EVENING. PATCHY MVFR FOG WILL BE POSSIBLE LATE
TONIGHT BEFORE CLEARING OUT SHORTLY AFTER SUNRISE ON MONDAY. WINDS
WILL BE GENERALLY BETWEEN 5 AND 10 KTS FOR THE REMAINDER OF THIS
AFTERNOON...FROM THE SOUTHWEST...AND LIGHT AND VARIABLE TONIGHT INTO
MONDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...AR
LONG TERM...DUSTY
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
406 PM EDT SUN SEP 29 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 405 PM EDT SUN SEP 29 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A 130 KNOT 250-300 MB JET INTO
THE PAC NW AS A TROUGH LINGERS OFFSHORE FROM BC. DOWNSTREAM HEIGHTS
WERE RISING ACROSS THE UPPER MS VALLEY AND WRN GREAT LAKES IN THE
WEAK OF THE DEPARTING TROUGH INTO NE ONTARIO. AT THE SFC...SW WINDS
WERE INCREASING AS SFC RIDGE FROM NRN LOWER MI TO SE KS GRADUALLY
SLIDES TO THE SE.
TONIGHT...CLEAR SKIES AND LIGHT WINDS ESPECIALLY INTO THE EARLY
OVERNIGHT HOURS SHOULD ALLOW FOR MIN TEMPS TO DIP INTO THE LOWER TO
MID 40S OVER THE INTERIOR CENTRAL AND EAST WHILE SOUTHERLY DOWNSLOPE
WINDS AND ASSOC MIXING WILL KEEP TEMPS IN THE LOWER 50S ALONG LAKE
SUPERIOR. PATCHY FOG OVER THE INTERIOR EAST HALF WILL BE POSSIBLE
AS LIGHT SOUTHERLY UPSLOPE FLOW FROM LAKE MI WILL CONTRIBUTE ADDED
LOW LEVEL MOISTENING.
MONDAY...SW WAA WILL INCREASE...PUSHING 850 MB TEMPS INTO THE 12C TO
14C RANGE. DESPITE SOME INCREASE IN HIGH CLOUDS...PER 600-400 MB RH
FCST...SUNSHINE AND MIXING INTO THE 875-850 MB LAYER SUPPORTS MAX
TEMPS ON THE HIGHER SIDE OF GUIDANCE...INTO THE LOWER TO MID 70S.
FCST MIXED LAYER WINDS INTO THE 25-30 KNOT RANGE SHOULD RESULT IN
WIND WINDS GUSTING TO AROUND 30 MPH IN THE AFTERNOON. WITH DEWPOINTS
ALSO DROPPING INTO THE LOWER 40S RESULTING IN RH VALUES OF AROUND 35
PERCENT...FIRE WEATHER RISKS WILL INCREASE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 405 PM EDT SUN SEP 29 2013
FOR MON NIGHT THROUGH WED...A LOW PRESSURE SYSTEM WILL MOVE ACROSS
NRN ONTARIO ON TUESDAY...DRAGGING A WEAK SFC TROUGH/COLD FRONT
ACROSS THE CWA TUE AFTERNOON INTO EARLY TUE NIGHT. 850MB TEMPS
INCREASE BY 3-4C TO AROUND 17C MON NIGHT IN INCREASING SW FLOW AHEAD
OF THE TROUGH. THIS WILL MAKE FOR A WARM AND GUSTY MON
NIGHT...ESPECIALLY IN DOWNSLOPING REGIONS FROM THE NW WINDS. WHILE
THE FRONT MOVES THROUGH ON TUE...DO NOT EXPECT ANY PRECIP. THE
00Z/29 ECMWF BROUGHT RAIN A BIT FARTHER S THAN THE PREVIOUS
RUNS...BUT IT IS ONE OF THE ONLY MODELS SHOWING PRECIP THAT FAR
S...AND IT DOES NOT SEEM REALISTIC SINCE THE BEST FORCING FROM THE
LOW WILL BE N OF THE CWA AND THE RIGHT EXIT REGION OF THE UPPER JET
WILL BE OVER THE AREA. WILL KEEP THE TIME PERIOD DRY AT THIS TIME.
WITH WNW WINDS AND COOLER TEMPS OVERHEAD...WED LOOKS TO SEE CLOSER
TO SEASONAL TEMPS...BUT STILL ABOVE NORMAL WITH HIGHS IN THE 60S TO
AROUND 70.
THINGS BECOME SIGNIFICANTLY MORE UNCERTAIN THU THROUGH SUN AS MODELS
CONTINUE TO HAVE VERY POOR RUN TO RUN CONTINUITY AND MODEL TO MODEL
AGREEMENT IS LACKING. THE UNCERTAINTY IS WITH MORE SIGNIFICANT UPPER
LEVEL ENERGY THAT MODELS HAVE MOVING INTO THE CENTRAL CONUS LATE IN
THE WEEK INTO NEXT WEEKEND...WHICH COMBINES WITH OTHER MORE SUBTLE
PIECES OF UPPER ENERGY TO POSSIBLY CAUSE RAPID SFC CYCLOGENESIS OVER
THE PLAINS. WITH THIS TYPE OF VOLATILE SYSTEM...SUBTLE FEATURES THAT
ARE BEYOND THE PREDICTABLE CAPABILITIES OF LOWER RESOLUTION MODELS
AT THIS RANGE WILL MAKE SIGNIFICANT DIFFERENCES IN THE STRENGTH AND
TRACK OF THE SYSTEM...WHICH MAKES FOR HUGE CHANGES IN THE
FORECAST...ESPECIALLY WITH MORE SPECIFIC DETAILS. IF THE SYSTEM DOES
FOLLOW THE WORST CASE SCENARIO...WINDS WOULD BE THE PRIMARY THREAT
AS THE SYSTEM WOULD DEEPEN WHILE MOVING ACROSS THE CWA BEFORE VERY
QUICKLY MOVING OFF TO THE NE...CAUSING A RAPID PRESSURE CHANGE AND
STRONG GRADIENT FLOW. THIS WORST CASE SCENARIO WOULD RESULT IN VERY
STRONG WINDS /ESPECIALLY OVER THE GREAT LAKES/ WITH STORM FORCE
WINDS POSSIBLE. OTHERWISE...PRECIP LOOKS TO FALL ENTIRELY...OR AT
LEAST MOSTLY...IN THE FORM OF RAIN. HOWEVER...IT IS WORTH NOTING
AGAIN THAT THE FORECAST FOR THIS SYSTEM IS VERY UNCERTAIN AND MODEL
DEPICTIONS WILL SURELY CHANGE OVER THE NEXT FEW DAYS. WHILE THERE IS
NO VALUE IN ADDING TOO MANY SPECIFIC DETAILS ABOUT THE
SYSTEM...THOSE WITH VULNERABLE INTERESTS /ESPECIALLY TO WINDS/
SHOULD KEEP UPDATED ON THIS PART OF THE FORECAST. ONE THING THAT
DOES LOOK MORE CERTAIN IS THAT COLDER TEMPS AND MORE
UNSETTLED/WETTER WEATHER LOOKS IN STORE FOR THE LAST FEW DAYS OF THE
FORECAST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 133 PM EDT SUN SEP 29 2013
VFR CONDITIONS WILL CONTINUE THROUGH THE FCST PERIOD. LLWS IS
EXPECTED AT IWD AND CMX TONIGHT AS STRONG SW WINDS DEVELOP ABOVE THE
DECOUPLED SFC LAYER.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EDT SUN SEP 29 2013
AS HIGH PRESSURE SHIFTS TO THE SOUTHEAST AND A TROUGH DEVELOPS OVER
THE NORTHERN PLAINS SOUTH WINDS WILL INCREASE TO 15 TO 25 KNOTS LATE
TONIGHT AND MONDAY WITH A GRADUAL SHIFT TO THE SOUTHWEST ON TUESDAY.
WINDS WILL DIMINISH WED AS A RIDGE BUILDS INTO THE AREA. CONFIDENCE
IN THE WIND FORECAST DROPS OFF BY LATE THIS WEEK AS MODELS OFFER
DIFFERING SOLUTIONS ON THE DEVELOPMENT AND MOVEMENT OF A SURFACE LOW
INTO THE WESTERN GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
148 PM EDT SUN SEP 29 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 531 AM EDT SUN SEP 29 2013
08Z WV IMAGERY AND RUC ANALYSIS SHOW A PROMINENT SHORTWAVE TROUGH
MOVING THROUGH THE UPPER GREAT LAKES. THIS SHORTWAVE HAS PUSHED A
SFC COLD FRONT EAST OF UPPER MI EARLY THIS MORNING. LATEST RADAR
IMAGERY SHOWS THAT LAST OF SHRA ASSOC WITH FRONT HAS PUSHED EAST OF
THE FCST AREA. GUSTY WESTERLY WINDS AT OR ABOVE 30 KT OVER THE
PORTAGE CANAL AND CENTRAL/ERN LAKE SUPERIOR IN THE WAKE OF THE COLD
FRONT SHOULD DIE DOWN QUICKLY IN THE NEXT FEW HOURS AS THE PRES
GRADIENT SLACKENS WITH THE HIGH PRES RDG BUILDING IN FM THE
WEST.
TODAY...MODELS IN AGREEMENT SHOWING SHORTWAVE TROUGH LIFTING INTO
NORTHERN ONTARIO AND REACHING JAMES BAY THIS AFTERNOON.
SUBSIDENCE/DRYING IN THE WAKE OF THE COLD FRONT HAS RESULTED IN
CLEAR SKIES ACROSS THE FCST AREA EARLY THIS MORNING. HOWEVER...THE
850 MB THERMAL TROUGH SHOULD SUPPORT THE DEVELOPMENT OF SCT-BKN
STRATOCU CLOUDS OVR THE CNTRL AND EASTERN FCST AREA BY LATE MORNING
INTO EARLY AFTERNOON. MIXING TO 850 MB RESULTS IN MAX TEMPS IN THE
MID TO UPPER 60S MOST LOCATIONS.
TONIGHT...CLEAR SKIES AND LIGHT WINDS ESPECIALLY INTO THE EARLY
OVERNIGHT HOURS SHOULD ALLOW FOR MIN TEMPS TO DIP INTO THE LOWER TO
MID 40S OVER THE INTERIOR CENTRAL AND EAST WHILE SOUTHERLY DOWNSLOPE
WINDS AND ASSOC MIXING WILL KEEP TEMPS CLOSER TO 50F ALONG THE LAKE
SUPERIOR SHORE. LEFT IN PATCHY FOG OVER THE INTERIOR EAST HALF AS
LIGHT SOUTHERLY UPSLOPE FLOW FROM LAKE MI COULD CONTRIBUTE ADDED
MOISTENING FOR SOME FOG DEVELOPMENT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 531 AM EDT SUN SEP 29 2013
UPCOMING WEEK FEATURES A NEGATIVE PACIFIC AND NORTH AMERICAN /PNA/
TELECONNECTION PATTERN WITH BROAD ENERGETIC TROUGHING GULF OF ALASKA
INTO PACIFIC NORTHWEST EARLY THIS WEEK EVENTUALLY TRANSLATING INTO A
STRONG TROUGH INTO THE CNTRL CONUS MID TO LATE WEEK. AS TROUGH MOVES
TO CNTRL CONUS...LOW LEVEL CYCLOGENESIS DEVELOPS FROM CNTRL PLAINS
TO THE UPPER MISSISSIPPI RIVER VALLEY ON THURSDAY. SFC LOW AND A
COLD FRONT SLIDES ACROSS UPPER GREAT LAKES ON FRIDAY THOUGH IT IS
PRETTY UNCERTAIN HOW STRONG OF SYSTEM WILL OCCUR. MUCH COOLER AIR
DROPS ACROSS UPPER LAKES IN WAKE OF THE LOW LATER FRIDAY INTO
SATURDAY. AIRMASS LOOKS CERTAINTY COLD ENOUGH TO RESULT IN SOME LK
EFFECT RAIN...BUT PROBABLY JUST STAYS WARM ENOUGH TO KEEP MIXED
PRECIPITATION OUT OF THE PICTURE...AT LEAST FOR NOW.
AHEAD OF THE DEVELOPING TROUGHING ALOFT AND EVENTUALLY AT THE
SFC...WARM AIR ADVECTION ALOFT AND DIVERGENCE ALOFT WILL SPREAD
VEILS OF MID AND HIGH CLOUDS ACROSS NORTHERN PLAINS AND UPPER LAKES
EARLY THIS WEEK. LOW-LEVELS TOO DRY TO ADD ANY RAIN SHOWERS DESPITE
THE WARM AIR ADVECTION. WITH A LOWER SUN ANGLE NOW BECOMING A
FACTOR...CLOUDS WILL CUT INTO EXPECTED MAX TEMPS SOME BUT WILL
STILL SEE TEMPS 10-15 DEGREES ABOVE NORMAL WITH READINGS TOPPING
OUT IN THE LOW TO MID 70S. BOTH DAYS MAY BE ON THE BREEZY SIDE AS
WELL...WITH BEST SHOT OF SEEING 30+ MPH GUSTS ON MONDAY AS LOW-LEVEL
JET SLIDES ACROSS AREA. HIGHER CLOUDS WILL DAMPEN DEEPER MIXING
POTENTIAL AND WILL LIKELY KEEP HUMIDITY VALUES FROM BOTTOMING OUT
TOO MUCH...BUT STILL COULD SEE INTERIOR WEST CWA DROP TO 35 PCT
BOTH MONDAY AND TUESDAY AFTN. IF TRENDS HOLD UP COULD SEE NEED FOR
A WILDFIRE POTENTIAL STATEMENT OR AT LEAST A MENTION IN HAZARDOUS
WEATHER OUTLOOK. LEAD SFC TROUGH CROSSES THE REGION LATE TUESDAY
NIGHT INTO WEDNESDAY. STILL TOO DRY FOR ANY RAIN...BUT SHOULD SEE
YET ANOTHER SURGE OF MID CLOUDS AND WILL SEE TEMPS COOL 5-10F
COMPARED TO MONDAY AND TUESDAY. WESTERLY WINDS RESULT IN THE MOST
NOTEABLE COOLING OVER THE KEWEENAW. HUMIDITY VALUES ACTUALLY COULD
BE LOWER ON WEDNESDAY AS DWPNTS DROP FURTHER.
MAIN WEATHER FOCUS FOR THE WEEK WILL BE LATE THIS WEEK AND INTO NEXT
WEEKEND AS DEEP TROUGH AFFECTS THE GREAT LAKES. UNCERTAINTY ABOUNDS.
MODELS CONTINUE TO STRUGGLE IN HOW QUICKLY TO BRING INITIAL
LOW-LEVEL TROUGHING AND THE RESULTANT SURGE OF WARM AIR ADVECTION
AND UPPER DIVERGENCE GENERATED SHOWERS INTO THE UPPER LAKES. LATEST
GFS SHOWING A QUICKER TREND IN BRINGING QPF ACROSS MOST OF CWA BY
12Z THURSDAY THAN PREVIOUS THREE RUNS DID. ECMWF WHICH HAS REALLY
BEEN ALL OVER THE PLACE WITH ITS TIMING HAS JOINED GFS IN SHOWING
QUICKER EASTWARD TREND. GEM-NH IS GENERALLY CONSISTENT WITH PREVIOUS
RUNS IN KEEPING MOST OF THE QPF WEST OF CWA BY 12Z THURSDAY AND ONLY
SLOWLY BRINGING IT ACROSS AS MAJORITY OF DIVERGENCE ALOFT HELPS TO
FOCUS CONCENTRATED AREA OF RAIN OVR MINNESOTA INTO NW ONTARIO ALONG
AND NORTH OF COOLER SIDE OF DEVELOPING SFC-H85 LOWS IN ENHANCED FGEN
AREA. GIVEN UNCERTAINTY AND INCONSISTENCIES BTWN THE GFS...ECMWF AND
GEM-NH HAVE STAYED CLOSE TO CONSENSUS HIGHER CHANCE POPS THURSDAY
INTO FRIDAY. PROBABLY WILL BE ONE OR TWO PERIODS OF GREATER RAIN
CHANCES...BUT DETAILS ARE FAR FM CERTAIN. ELEVATED INSTABILITY WITH
SI/S BLO 0C LED TO ADDING TSRA OVER SCNTRL ON THURSDAY IN WHAT
SHOULD BE THE WARMER SECTOR OF THE CYCLONE. FRONTAL BOUNDARY RAINS
MOVE THROUGH THURSDAY NIGHT OR FRIDAY. MAIN STICKING POINT IS JUST
HOW WRAPPED UP WILL SFC LOW TREND AS IT MOVES THROUGH...MAINLY
LEADING TO RAIN COVERAGE ISSUES WITH POTENTIAL DRY SLOT. AT THIS
POINT...APPEARS THAT UPPER LAKES WOULD BE ON COOLER/WETTER SIDE OF
THE LOW WITH SOME POTENTIAL FOR HEAVIER RAIN WITH PWATS OF 1.5
INCHES OR 200 PCT OF NORMAL INTERACTING WITH LOW-LEVEL FGEN AND
UPSLOPE FLOW OFF LK SUPERIOR.
THOUGH DETAILS OF HOW WE GET THERE ARE UNCLEAR...IT EVENTUALLY TURNS
MUCH COOLER LATER FRIDAY INTO SATURDAY AS THE LOW SLOWLY MOVES AWAY
FROM REGION AS UPPER TROUGH DEEPENS OVER GREAT LAKES. H85 TEMPS TO
AT LEAST -4C SEEM LIKE GOOD BET...LEADING TO PLENTY OF LK EFFECT
CLOUDS /LK SFC TEMPS AROUND +12C ON AVERAGE/ AND PROBABLY SOME LK
EFFECT SHOWERS FRIDAY NIGHT INTO SATURDAY MORNING IF THERE IS ENOUGH
SYNOPTIC MOISTURE/CYCLONIC FLOW LINGERING DURING THIS TIME. THE
MOISTURE WILL ALSO FACTOR IN ON WHETHER THE FIRST SNOWFLAKES OF THE
YEAR WILL FLY OVER THE CWA. RIGHT NOW WILL KEEP THE SNOW OUT OF THE
FORECAST AS LATEST RUNS ARE MORE PROGRESSIVE WITH THE LOW AND DRY
OUT THE H85-H7 LAYER CONSIDERABLY. IN THE FOR WHAT IT IS WORTH
DEPARTMENT...TWO CLOSEST SLU CIPS ANALOGS TURNED UP EVENTS FROM LATE
SEPTEMBER AND MID OCTOBER THAT PRODUCED OVER AN INCH OF RAIN ACROSS
PARTS OF CWA WITH SOME SNOW AS THOSE SYSTEMS DEPARTED. WE SHALL SEE
ON THIS ONE. CERTAINLY WILL BE A CHILLY START TO NEXT WEEKEND WITH
THE HIGHER TERRAIN OF THE NORTH STAYING IN THE 40S AS A GUSTY NW WIND
ONLY ADDS TO THE CHILL.
COOLER PATTERN DOES NOT LOOK TO PERSIST THOUGH AS BOTH GFS/ECMWF
INDICATE WARMER TEMPS RETURNING IN SOME SHAPE OR FORM DAYS 7-10.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 133 PM EDT SUN SEP 29 2013
VFR CONDITIONS WILL CONTINUE THROUGH THE FCST PERIOD. LLWS IS
EXPECTED AT IWD AND CMX TONIGHT AS STRONG SW WINDS DEVELOP ABOVE THE
DECOUPLED SFC LAYER.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 531 AM EDT SUN SEP 29 2013
THERE COULD BE A BRIEF PD OF GALE FORCE GUSTS ALONG AND EAST OF THE
KEWEENAW PENINSULA EARLY THIS MORNING DUE TO FAVORED WESTERLY
CONVERGENT FLOW IN THE WAKE OF THE COLD FRONT. HIGH PRESSURE WILL
THEN BUILD IN TODAY AND QUICKLY DECREASE THE WINDS ACROSS THE
LAKE. THIS HIGH WILL SHIFT SOUTHEAST LATE MONDAY...AS A LOW PRESSURE
SYSTEM MOVES ACROSS CENTRAL CANADA. THIS WILL RESULT IN A BRIEF
INCREASE IN SOUTHERLY WINDS OVER LAKE SUPERIOR LATE MONDAY AND INTO
TUE MORNING WITH A FEW GUSTS REACHING 25 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1242 PM CDT SUN SEP 29 2013
.UPDATE...
ISSUED AT 1240 PM CDT SUN SEP 29 2013
THICKENING CIRRUS OVERSPREADING THE NORTHWEST 2/3 OF THE CWFA
HAVING A LITTLE IMPACT ON INSOLATION. TEMPERATURES ARE RISING
FASTER ACROSS THE SOUTH BUT WITHIN A DEGREE OR TWO ACROSS THE
NORTH. WILL TWEAK THE CURVE BUT OTHERWISE THE FORECAST APPEARS
STILL ON TRACK.
UPDATE ISSUED AT 1008 AM CDT SUN SEP 29 2013
ONLY MINOR CHANGES TO THIS UPDATE...MAINLY TO INCREASE THE CLOUD
COVER ACROSS THE NORTH. VISIBLE SAT SHOWS WHAT APPEARS TO BE
THICKER CIRRUS MOVING TO THE E/NE. CROSS-SECTIONS USING THE RAP AND
GFS IN FAIR AGREEMENT WITH THE VISIBLE. OTHERWISE WITH SOUTHWEST
FLOW SUSPECT TEMPERATURES ON TRACK FOR MIDDLE TO UPPER 70S MOST AREAS.
UPDATE ISSUED AT 650 AM CDT SUN SEP 29 2013
FORECAST IS IN GOOD SHAPE WITH NO CHANGES NEEDED AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 332 AM CDT SUN SEP 29 2013
CHALLENGES INCLUDE TEMPERATURES AND WIND THROUGH THE PERIOD. WILL
FOLLOW A BLEND OF THE NAM/ECMWF/GEM AS THE LATEST GFS IS TOO FAST
WITH THE FRONTAL PASSAGE MONDAY NIGHT.
FOR TODAY...EXPECT PLENTY OF SUN BETWEEN PERIODS OF HIGH CLOUDS AS
THE REGION REMAINS BETWEEN WEATHER SYSTEMS. MODEL SOUNDINGS SHOW A
7 TO 10 C RISE IN BOUNDARY LAYER TEMPERATURES COMPARED TO YESTERDAY...
RESULTING IN AFTERNOON HIGHS IN THE LOWER TO MID 70S. WITH 25 TO 30
KTS TO MIX TO THE SURFACE...SOUTHERLY WINDS WILL BECOME BREEZY
WITH SOME GUSTS TO 25 MPH.
MONDAY WILL BE SIMILAR TODAY...EXCEPT A BIT WARMER WITH LESS WIND.
HIGHS WILL TOP OUT IN THE MID TO UPPER 70S WITH SOUTH-SOUTHWEST
WIND FROM 10 TO 15 MPH.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 AM CDT SUN SEP 29 2013
A COLD FRONT WILL SWEEP ACROSS THE FORECAST AREA MONDAY NIGHT...
BRINGING A SLIGHT CHANCE OF RAIN SHOWERS ACROSS THE NORTH. BEST
FORCING AND MOISTURE IS NORTH OF THE CANADIAN BORDER...SO NOT
EXPECTING MUCH ACCUMULATION IF ANYTHING DOES DEVELOP. BIGGER
SENSIBLE WEATHER IMPACT WILL BE INCREASING WEST-SOUTHWEST WIND
BEHIND THE FRONT. BOUNDARY LAYER DEEPENS TO NEAR 800 HPA BY
TUESDAY MID-AFTERNOON WITH 35 TO 40 KTS TO MIX TO THE SURFACE.
THIS COULD RESULT IN SUSTAINED WINDS IN EXCESS OF 30 MPH...THUS
REQUIRING A WIND ADVISORY. WAY TOO EARLY TO CONSIDER ISSUANCE...
BUT FOR SURE LOOKS TO BE A WINDY DAY. TEMPERATURES WILL ALSO DROP
BEHIND THE FRONT WITH HIGHS FROM THE MID 60S TO MID 70S.
LONG RANGE MODELS COMING INTO BETTER AGREEMENT WITH A MORE SOUTHERN
SOLN FOR THU-FRI SYSTEM AS 500 TROUGH DIGS A BIT INTO WYOMING AND
UPPER RIDGE TO THE EAST OVER THE GREAT LAKES IS FLATTER. 00Z EURO
CAME IN RESEMBLING THE 18Z SAT AND 00Z SUN GFS IN SHOWING THIS.
AFTER MUCH COORDINATION WENT CLOSER TO THIS SOLN WHICH REQUIRED
SIGNIFICANT CHANGES TO THE ALL BLEND FCST. KEPT SOME LOW SHOWER
CHANCES WEDNESDAY IN SE ND INTO NRN MN AS A WEAK SHORT WAVE MOVES
THRU...THEN LIMITED ANY CHANCE OF SHOWERS TO SOUTHEAST HALF OF THE
FCST AREA THU-THU NIGHT AND THEN DRY FRIDAY AS COLDER AIR MOVES
SOUTH. 00Z EURO HAS 850 MB TEMPS -4 TO -5C IN NE ND/NW MN FRI WITH
HIGH PRESSURE MOVING IN WHICH WOULD TRANSLATE TO A CHILLY FRI
NIGHT WITH WIDESPREAD SUB FREEZING LOWS. GFS NOT AS COLD BUT STILL
A BIT BLO 0C 850 MB TEMPS. LOWERED TEMPS A BIT FROM ALL BLEND TOOL
TO SHOW WIDESPREAD LOW-MID 30S FOR SAT MORNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1240 PM CDT SUN SEP 29 2013
CIRRUS POSSIBLE THROUGH THE PERIOD. OTHERWISE...THE MAIN CONCERN
WILL BE SOUTHERLY WINDS THIS AFTERNOON GUSTING UP TO 22-24 KNOTS.
THE GUSTINESS WILL CEASE AROUND SUNSET...WITH WINDS REMAINING
AROUND 10 KNOTS OVERNIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...EWENS
SHORT TERM...ROGERS
LONG TERM...ROGERS/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
244 PM CDT SUN SEP 29 2013
.SHORT TERM /NOW THROUGH MONDAY NIGHT/...FAIRLY COMPLEX
SYNOPTIC/MESOSCALE PATTERN THIS AFTERNOON. THERE APPEARS TO BE A
WEAK SFC RIDGE ABOUT 50 MILES EAST OF SOUTH PADRE ISLAND...AND A
WEAK PRESSURE TROUGH THAT HAS MOVED SOUTHEAST TO ROUGHLY A MCALLEN
TO BAFFIN BAY LINE. AT THE SAME TIME RADAR AND VISIBLE SATELLITE
SHOW AN MCV/CLOSED CYCLONE PATTERN ABOUT 20 MILES WEST OF ZAPATA
COUNTY WHICH IS MORE FOCUSED THAN THE 850MB TROUGH THAT SHOWED UP
ON THE 12Z UPPER AIR CHART. THIS FEATURE HAS LITTLE APPARENT
SURFACE REFLECTION. UPPER LEVEL RIDGING STRETCHES FROM THE WESTERN
GULF OF MEXICO INTO NORTH CENTRAL MEXICO AND A JET MAX ASSOCIATED
WITH A DEEPENING WEST TEXAS TROUGH IS BECOMING SLIGHTLY MORE
DIFFLUENT JUST TO OUR NORTHWEST AS IT PARTIALLY CURVES SOUTHWARD
AROUND THE RIDGE. COLUMN MOISTURE APPEARS TO BE INCREASING PER
SATELLITE PWAT ESTIMATES AND PERIODIC LOW CLOUD COVERAGE AND
MODIFIED RAP AND OBSERVED SOUNDINGS SUGGEST THE BOUNDARY LAYER IS
MODERATELY UNSTABLE BUT A RESIDUAL 850MB CAP IS VERY LIKELY
HOLDING BACK INITIATION AT THIS HOUR WHICH BASED ON THE VERTICAL
EXTENT OF CUMULUS CLOUDS SO FAR SEEMS TO MAKE SENSE.
REST OF THE AFTERNOON...VWP SHOWS MODEST WESTERLY WINDS WHICH
SHOULD BE TRANSPORTING THE RICHER COLUMN MOISTURE INTO THE
REGION...WHICH IS FAIRLY COUNTER INTUITIVE FOR OUR GEOGRAPHY. DO NOT
BELIEVE THAT THE VELOCITY OR TRAJECTORY WILL INCREASE OUR
CAPPING...BUT IT MAY...AND THAT MAY KEEP CONVECTIVE INITIATION HELD
BACK UNTIL UPPER TROUGHING GETS CLOSER. RESIDUAL OUTFLOW BOUNDARIES
AND A SEABREEZE FRONT SHOULD BE ABLE TO GET AT LEAST SOMETHING GOING
BY 4 PM HOWEVER. ANYTHING THAT GOES UP WILL BE VIRTUALLY STATIONARY
AND WITH INCREASING PWATS A HEAVY RAIN/FLOODING THREAT EXISTS.
TONIGHT...GFS IS THE SLOWEST BRINGING THE TROUGH THROUGH AND DOES
NOT SUBSTANTIALLY INCREASE UPPER DIVERGENCE/LIFT UNTIL ABOUT
MIDNIGHT TONIGHT AND KEEPS THE WINDOW OPEN FOR HIGHER CONVECTIVE
COVERAGE MONDAY. RAP/HRRR/NAM START LARGE SCALE UPPER LIFT
EARLIER...BY LATE AFTERNOON...AND CLEARS THE AREA FASTER ON MONDAY.
WATER VAPOR AND GOES DERIVED WINDS LEAD ME TO BELIEVE AT LEAST SOME
DIFFLUENCE WILL BEGIN SHORTLY AND LIKELY HELP GET A DECENT AMOUNT OF
CONVECTION GOING OVER AT LEAST THE CENTRAL PART OF THE CWA BY 6 OR 7
PM...WITH THE CHANCE MOVING EASTWARD THROUGH THE EVENING. UPPER LIFT
PEAKS AROUND 06Z/100 AM CDT OVER THE AREA AND THE FORECAST REFLECTS
THE HIGHEST RAINFALL CHANCES AROUND THIS TIME. BUMPED UP TO LIKELY
POPS OVER THE COASTAL WATERS WHERE INSTABILITY WILL BE STRONGER IN
THE PRE DAWN HOURS. LOCALLY HEAVY RAINFALL/FLOODING WILL BE A
CONCERN...ESPECIALLY UNTIL LATER IN THE NIGHT WHEN THE DEEPER LAYER
STEERING WINDS INCREASE AND START TO MOVE THE CONVECTION ALONG MORE
QUICKLY.
MONDAY...BELIEVE THE GFS IS ON THE RIGHT TRACK AS FAR AS COMPLETE
CLEARING OF THE SHORTWAVE TROUGH...AND THE 12Z ECMWF AGREES FAIRLY
WELL. SO KEPT 30/40 PCT POPS THROUGH THE DAY ON MONDAY WITH THE
CHANCE STARTING TO WANE AFTER ABOUT 2100Z/400 PM AS THE TROUGH AXIS
CLEARS. CONVECTION SHOULD BE FASTER MOVING ON MONDAY. PREVAILING
WINDS WILL BE FAIRLY LIGHT WITH TEMPERATURES FLUCTUATING AROUND
CONVECTION WITH A WINDOW FOR HEATING BEFORE REDEVELOPMENT IN THE
MORNING...AND AFTER STORMS START TO WANE IN THE LATE AFTERNOON.
MONDAY NIGHT...BEHIND THE DEPARTING TROUGH UPPER SUBSIDENCE SHOULD
LIMIT RAIN CHANCES TO THE COASTAL WATERS WITH LIGHT WINDS. DEPENDING
ON HOW MUCH RAIN FALLS THERE MAY BE A THREAT FOR GROUND FOG OR
RADIATION FOG GIVEN THE EXPECTED LIGHT WINDS...BUT DID NOT INCLUDE
IN THE GRIDS FOR NOW. /68-JGG/
.LONG TERM /TUESDAY THROUGH SUNDAY/...500MB LOW ACROSS EAST TEXAS
AND LOUISIANA TUESDAY SHOULD PROVIDE SUBSIDENCE ACROSS SOUTHWEST
TX BUT LOW TO MID LEVEL MOISTURE IS PROGGED TO LINGER ACROSS
NORTHEAST MEXICO AND THE NORTHWEST GULF OF MEXICO SO WILL KEEP A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE CWA TUESDAY.
THE UPPER LEVEL FEATURE ACROSS THE NORTHWEST GULF COAST LINGERS
WEDNESDAY BEFORE MOVING NORTHEAST THURSDAY. A 500MB TROUGH WILL
DEVELOP ACROSS THE WESTERN UNITED STATES THURSDAY AND MOVE EASTWARD
FRIDAY BRINGING A WEAK COLD FRONT INTO SOUTH TX SATURDAY. THIS
WILL PROVIDE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FRI
NIGHT INTO SATURDAY ACROSS THE RIO GRANDE VALLEY AS MOISTURE POOLS
ALONG AND AHEAD OF THE FRONT. DRIER AND SLIGHTLY COOLER AIR WILL
FILTER INTO THE AREA IN THE WAKE OF THE FRONT SAT NIGHT INTO SUNDAY.
&&
.MARINE...
NOW THROUGH MONDAY NIGHT...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO START BY LATE EVENING AND PERSIST
THROUGH MONDAY. PREVAILING WINDS AND SEAS WILL BE FAIRLY LIGHT OUT
OF THE EAST TO SOUTHEAST OVERNIGHT WITH LOW TO MODERATE SEAS. MORE
MODERATE SOUTH TO SOUTHEAST WINDS ARE EXPECTED TO BUILD IN MONDAY
MORNING PERSISTING THROUGH MONDAY NIGHT WITH LOW TO MODERATE SEAS.
TUESDAY THROUGH FRIDAY...LIGHT TO MODERATE SOUTH TO SOUTHEAST WINDS
WILL PREVAIL ACROSS THE COASTAL WATERS TUESDAY AND WEDNESDAY WITH
HIGH PRESSURE ACROSS THE SOUTHEAST UNITED STATES. THE PRESSURE
GRADIENT WILL INCREASE SLIGHTLY ACROSS THE WESTERN GULF OF MEXICO ON
THURSDAY AS LOW PRESSURE DEVELOPS ACROSS THE LEE SIDE OF THE
ROCKIES. MODERATE SOUTHEAST TO SOUTH WINDS WILL PREVAIL ACROSS THE
LOWER TEXAS COAST THURSDAY INTO FRIDAY AS A WEAK COLD FRONT MOVES
INTO NORTHWEST TX FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 77 91 78 90 / 50 40 20 20
BROWNSVILLE 77 91 76 91 / 50 40 20 20
HARLINGEN 75 91 76 93 / 50 40 20 20
MCALLEN 76 92 76 95 / 50 40 10 20
RIO GRANDE CITY 74 91 77 93 / 30 30 10 20
SOUTH PADRE ISLAND 79 87 79 87 / 60 40 20 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/61/MARTINEZ