Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/02/13
AREA FORECAST DISCUSSION
NWS FLAGSTAFF AZ
330 PM MST WED JUL 31 2013
.SYNOPSIS...MOISTURE AND INSTABILITY HAS INCREASED OVER NORTHERN
ARIZONA WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TODAY.
THUNDERSTORM COVERAGE SHOULD INCREASE FURTHER ON THURSDAY AND FRIDAY.
&&
.DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED FROM
NEAR DESERT VIEW AT THE GRAND CANYON...MOGOLLON RIM...TO THE WHITE
MOUNTAINS TODAY. THE STORMS ARE MOVING NORTHWARD INTO THE LCR THIS
AFTERNOON. THIS ACTIVITY IS EXPECTED TO CONTINUE INTO THIS EVENING.
VISIBLE SATELLITE SHOWED SEVERAL UPPER DISTURBANCES OVER NORTHERN
MEXICO THIS MORNING. THESE DISTURBANCES ARE MORNING NORTHWARD AND
MAY WELL CONTINUE THUNDERSTORM ACTIVITY WELL INTO THE NIGHT OVER
NORTHERN ARIZONA. THE 17Z RUN OF THE HRRR SHOWED RAIN SHOWERS
RE-DEVELOPING OVER THE RIM COUNTRY LATE THIS EVENING. HAVE KEPT
CHANCE POPS GOING THROUGH THE NIGHT FOR THE HIGHER TERRAIN OVER MUCH
OF NORTHERN ARIZONA.
HIGH PRESSURE WILL REMAIN EAST OF ARIZONA FOR THE NEXT WEEK. ARIZONA
WILL BE ON THE WESTERN EDGE OF THE HIGH WITH A SOUTH TO SOUTHWEST
FLOW OVER THE STATE. THE GFS AND EC ARE AT ODDS ON HOW MUCH MOISTURE
WILL MOVE OVER THE STATE AND IF/WHEN SIGNIFICANT DRYING WILL HAPPEN.
FORECAST LEANS MORE TOWARD THE EC GIVEN HOW IT HAS HANDLED THE
WETTER PATTERN SO FAR THIS SUMMER.
SHOWER AND THUNDERSTORM COVERAGE SHOULD INCREASE EACH DAY ACROSS
THE AREA THROUGH FRIDAY AND THEN REMAIN FAIRLY CONSTANT THROUGH THE
WEEKEND.
&&
.AVIATION...FOR THE 00Z PACKAGE...MONSOON MOISTURE IS ON THE
INCREASE. ISOLATED TO SCATTERED THUNDERSTORMS WILL CONTINUE UNTIL
04Z...DIMINISHING THE REMAINDER OF THE NIGHT. WIND GUSTS UP TO 40
KTS NEAR STORMS. THUNDERSTORM WILL DEVELOP AGAIN ON THURSDAY AFTER
18Z. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...MONSOON MOISTURE WILL PUSH BACK ACROSS NORTHERN
ARIZONA WITH AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS ON
THURSDAY AND FRIDAY.
SATURDAY THROUGH MONDAY...THE CHANCE FOR SHOWERS AND THUNDERSTORMS
WILL CONTINUE OVER NORTHERN ARIZONA.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC.........MAS
AVIATION.......MCCOLLUM
FIRE WEATHER...MCCOLLUM
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1050 PM EDT THU AUG 1 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TONIGHT AND EARLY
FRIDAY BRINGING SHOWERS AND SCATTERED THUNDERSTORMS. MOSTLY DRY
WEATHER EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. HOWEVER...THERE
IS POTENTIAL FOR SOME SPOTTY SHOWERS SAT/SUN/TUE.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
1045 PM UPDATE...REGIONAL RADAR DATA NOT PAINTING AN OVERLY
IMPRESSIVE PICTURE AS FAR AS CONVECTION GOES. WILL BE BACKING OFF
COVERAGE OF THUNDERSTORMS THIS EVENING AS INSTABILITY AND FOCUSING
MECHANISMS ARE WEAK.
AS FAR AS TIMING GOES...THINKING THE 01/23Z HRRR HAD THE BEST
HANDLE ON THE CURRENT SITUATION. THAT SAID...DO THINK THAT MODEL
IS ABOUT TWO HOURS TWO SLOW MOVING RAINFALL THROUGH SOUTHERN NEW
ENGLAND...AS IT WAS JUST AS SLOW TO BRING IT INTO OUR REGION.
NO REAL CHANGES TO TEMPERATURES OR DEW POINTS NEEDED.
PREVIOUS DISCUSSION...
A MID LEVEL SHORTWAVE MOVES EAST FROM MI INTO NEW ENG OVERNIGHT
AND COMBINED WITH INCREASED CONVERGENCE FROM THE LOW LEVEL JET AND
ELEVATED INSTABILITY WILL BRING WIDESPREAD SHOWERS AND SCT TSTMS
TO SNE TONIGHT. PWATS INCREASE TO 1.75-2" SO LOCALLY HEAVY
RAINFALL AND AREAS OF URBAN AND POOR DRAINAGE FLOODING WILL BE THE
PRIMARY THREAT. HOWEVER...MODELS ARE GENERATING SOME SFC
INSTABILITY TONIGHT..ESPECIALLY NEAR THE COAST AS THE MID LEVELS
COOL AND THERE IS MODEST 0-1KM SHEAR MOVING THROUGH WITH
INCREASING 0-6KM SHEAR MOVING IN FROM THE WEST...SO WILL HAVE TO
MONITOR RADAR TRENDS CLOSELY FOR STRONGER CONVECTION LATER
TONIGHT.
FOCUS FOR CONVECTION WILL SHIFT TO EASTERN NEW ENG 06-12Z WITH
SOME CLEARING POSSIBLE ACROSS THE CT VALLEY TOWARD 12Z.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
LINGERING CONVECTION ACROSS EASTERN NEW ENG EARLY FRI WILL END AS
THE SHORTWAVE LIFTS TO THE NE AND THE FRONT MOVES OFF THE COAST.
GENERALLY LOOKING AT A DRY DAY WITH SCT-BKN CU DEVELOPING...HOWEVER
CANT COMPLETELY RULE OUT A SPOT SHOWER IN THE AFTERNOON AS THERE
IS MARGINAL INSTABILITY AND ANOTHER SHORTWAVE APPROACHES FROM
THE WEST. 850 MB TEMPS 13-14C SO IT WILL BE A WARM DAY WITH MAXES
LOW TO MID 80S...BUT COOLER HIGHER TERRAIN. HUMID IN THE
MORNING...ESPECIALLY E NEW ENG BUT DEWPOINTS WILL BE FALLING IN
THE AFTERNOON.
FRIDAY NIGHT...
YET ANOTHER SHORTWAVE WILL BE APPROACHING NEW ENG FROM THE GT
LAKES. MODELS DIFFER ON LOCATION AND COVERAGE OF SHOWERS LATE FRI
NIGHT...SO CONFIDENCE IS LOW BUT WE HAVE CHC POPS IN W NEW ENG.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* MOSTLY DRY...SEASONABLE TO SEASONABLY COOL WEATHER
* FEW SHOWERS POSSIBLE SATURDAY...SUNDAY...AND TUESDAY
* NEXT CHANCE OF WIDESPREAD RAIN WED INTO THU
MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THIS WEEKEND THEN BEGIN
TO DIVERGE INTO EARLY NEXT WEEK. THE 01/00Z ECMWF INDICATES A MORE
ZONAL FLOW BETWEEN RIDGING TO THE SOUTH AND TROUGHING ACROSS
SOUTHERN CANADA WITH HIGH PRESSURE TO START THE WEEK. THIS RUN OF
THE ECMWF ALSO KEEPS A COASTAL LOW DEVELOPING OVER THE CAROLINAS AND
MOVING TO THE NORTHEAST TUESDAY AND THEN OUT TO SEA WEDNESDAY. THE
01/12Z GFS ON THE OTHER HAND DEVELOPS A BROAD TROUGH OVER THE
NORTHEAST WITH WESTERLY OR NORTHWESTERLY FLOW OVER SOUTHERN NEW
ENGLAND AND A COLD FRONT MOVING SLOWLY ACROSS SOUTHERN NEW ENGLAND
TUE AND WED. THE ECMWF HAS BEEN MORE CONSISTENT FROM RUN TO RUN SO
AM LEANING TOWARDS THAT SOLUTION WITH THE GREATEST THREAT OF
WIDESPREAD RAIN WEDNESDAY AND THURSDAY WITH A FEW SHOWERS POSSIBLE
SATURDAY...SUNDAY...AND TUESDAY.
SATURDAY AND SUNDAY...LOW PRESSURE IN QUEBEC BRINGS A WEAK COLD
FRONT THROUGH SOUTHERN NEW ENGLAND SATURDAY. WHILE THERE IS A LOW
PROBABILITY OF A FEW STRONG THUNDERSTORMS SATURDAY...THE TIMES OF
GREATEST SHEAR...INSTABILITY AND LIFT WITH THE FRONT ARE NOT ALIGNED
WELL SO EXPECTING MORE ALONG THE LINES OF SHOWERS AHEAD OF THE FRONT
WITH AN ISOLATED THUNDERSTORM OR TWO SATURDAY. HIGH PRESSURE STARTS
BUILDING INTO THE REGION SUNDAY BUT WITH A SHORTWAVE MOVING ACROSS
SOUTHERN NEW ENGLAND...A FEW DIURNAL SHOWERS ARE POSSIBLE SUNDAY AS
WELL. HAVE SLIGHT CHANCE TO CHANCE POPS ACROSS MUCH OF SOUTHERN NEW
ENGLAND DURING THIS TIME. OTHERWISE...EXPECT TEMPERATURES TO BE
RIGHT AROUND TO JUST BELOW NORMAL WITH PARTLY TO MOSTLY CLOUDY SKIES
DURING THE DAY.
MONDAY...HIGH PRESSURE MOVES OVER SOUTHERN NEW ENGLAND BRINGING
MOSTLY DRY WEATHER AND BELOW NORMAL TEMPS FOR EARLY AUGUST.
TUESDAY THROUGH THURSDAY...THIS IS WHERE THE MOST UNCERTAINTY IS IN
THIS FORECAST. THE GFS AND THE ECMWF HAVE FAIRLY DIFFERENT
SOLUTIONS. THE GFS BRINGS A COLD FRONT THROUGH SOUTHERN NEW ENGLAND
TUESDAY NIGHT INTO WEDNESDAY AND THE ECMWF KEEPS HIGH PRESSURE
DOMINANT OVER THE REGION WHILE A LOW PRESSURE SYSTEM MOVES UP TO THE
DELMARVA REGION FROM THE CAROLINAS AND THEN EASTWARD OUT TO SEA
DURING THE SAME TIME FRAME. THEN THURSDAY ON THE ECMWF...A PAIR OF
LOW PRESSURE SYSTEMS APPROACH SOUTHERN NEW ENGLAND BRINGING A
POSSIBILITY OF RAIN WHILE THE GFS BUILDS HIGH PRESSURE INTO THE
REGION. OVERALL THIS IS A FAIRLY UNSETTLED AND UNCERTAIN PATTERN
FOR THE MIDDLE OF NEXT WEEK. AS STATED ABOVE...LEANED MORE TOWARDS
THE MORE CONSISTENT ECMWF FOR THIS FORECAST...BUT WILL HAVE TO SEE
WHAT THE MODELS DO IN THE COMING DAYS.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE IN TRENDS THROUGH FRI...BUT LOWER CONFIDENCE IN
TIMING.
EXPECT LOWERING CONDITIONS THROUGH TONIGHT AS SHOWERS OVERSPREAD
THE REGION. WIDESPREAD MVFR WITH AREAS OF IFR DEVELOPING TONIGHT.
LOCALLY HEAVY RAIN IS POSSIBLE WITH THESE SHOWERS. IMPROVING
CONDITIONS LATE TONIGHT IN THE CT VALLEY WITH MORE WIDESPREAD
SHOWERS IN THE EAST 06-12Z.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR FROM WEST TO EAST DURING
FRIDAY...BUT NOT UNTIL THE AFTERNOON FOR THE CAPE/ISLANDS.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
TIMING. MVFR POSSIBLE IN SHOWERS DEVELOPING TONIGHT AND CANT RULE
OUT A PERIOD OF IFR CIGS...IMPROVING TO VFR FRIDAY MORNING.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
TIMING. MVFR IN SHOWERS DEVELOPING THIS EVENING...THEN IMPROVING
LATE TONIGHT. AREAS OF IFR POSSIBLE BUT CONFIDENCE IS NOT HIGH.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY AND SUNDAY...MODERATE TO HIGH CONFIDENCE. MAINLY VFR.
LOW PROBABILITY OF BRIEF MVFR/IFR CONDITIONS IN ISOLATED TO
SCATTERED SHOWERS.
MONDAY...HIGH CONFIDENCE. VFR.
TUESDAY...MODERATE CONFIDENCE. LIKELY VFR. LOW PROBABILITY OF
BRIEF MVFR/IFR CONDITIONS IN SCT SHRA.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
WINDS EXPECTED TO REMAIN BELOW SCA THRESHOLDS THROUGH FRI NIGHT.
GUSTS TO 20 KT POSSIBLE TONIGHT AS THE LOW LEVEL JET MOVES
THROUGH...WITH ANOTHER PULSE OF W/SW G20 KT FRI AFTERNOON AS LOW
LEVEL WINDS INCREASE. SEAS SHOULD REMAIN BELOW 5 FT THROUGH MUCH
OF FRI...BUT ARE EXPECTED TO BUILD TO 5 FT OVER SOUTHERN WATERS
LATE FRI AND ESPECIALLY FRI NIGHT.
OUTLOOK...SATURDAY THROUGH TUESDAY...
HIGH CONFIDENCE. MOSTLY QUIET BOATING WEATHER EXPECTED THROUGH
THIS WEEKEND INTO EARLY NEXT WEEK. LOW PROBABILITY OF SEAS UP TO 5
FEET ON THE OUTER WATERS AT TIMES SATURDAY AND SUNDAY. MAINLY
WESTERLY WINDS WILL REMAIN BELOW 25 KTS FOR THE MOST PART SHIFTING
TO THE SOUTHWEST OR NORTHWEST AT TIMES THROUGH THE PERIOD.
SATURDAY...A FEW GUSTS NEAR 25 KTS ON THE NEAR SHORE WATERS ALONG
THE SOUTH COAST.
&&
.CLIMATE...
THESE ARE THE LATEST STANDINGS FOR THE JULY AVERAGE TEMPERATURE.
ALL 4 OF THE MAJOR CLIMATE SITES FINISHED IN THE TOP 5.
BOSTON /LOGAN AIRPORT/
1. 78.0 IN 1983
2. 77.5 IN 1994 AND 1952
3. 77.3 IN 2011
4. 77.2 IN 2010 AND 1955
5. 77.1 IN 2013 AND 1911
PROVIDENCE /TF GREEN AIRPORT/
1. 78.4 IN 2013
2. 77.5 IN 2010
3. 76.6 IN 1983
4. 76.5 IN 1999
5. 76.4 IN 2008
HARTFORD/WINDSOR LOCKS /BRADLEY/
1. 77.9 IN 2013
2. 77.1 IN 2010 AND 1994
3. 77.0 IN 1955
4. 76.8 IN 1949
5. 76.5 IN 2006...1999 AND 1995
WORCESTER /AIRPORT/
1. 75.9 IN 1911
2. 74.3 IN 1952 AND 1901
3. 74.2 IN 1949
4. 74.1 IN 2013
5. 74.0 IN 2010
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KJC/RLG
NEAR TERM...BELK/KJC/RLG
SHORT TERM...KJC
LONG TERM...RLG
AVIATION...BELK/KJC/RLG
MARINE...KJC/RLG
CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
724 PM EDT THU AUG 1 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TONIGHT AND EARLY
FRIDAY BRINGING SHOWERS AND SCATTERED THUNDERSTORMS. MOSTLY DRY
WEATHER EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK. HOWEVER...
THERE IS POTENTIAL FOR SOME SPOTTY SHOWERS SAT/SUN/TUE.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
730 PM UPDATE...SCATTERED SHOWERS CONTINUE TO MOVE ACROSS
SOUTHERN NEW ENGLAND THIS EVENING. THERE WILL BE BREAKS IN THE
PRECIP AT TIMES TONIGHT. HOWEVER THERE ARE TWO AREAS OF SHOWERS TO
BE CONCERNED WITH AT THIS TIME. ONE IS AN AREA OF PRECIP SOUTH OF
LONG ISLAND CURRENTLY...WHICH SHOULD MOVE OVER SOUTHEASTERN
MASSACHUSETTS AND POSSIBLY THE SOUTHERN COAST OF RHODE ISLAND OVER
THE NEXT SEVERAL HOURS. THE OTHER IS A FINE LINE OF CONVECTION
MOVING ACROSS CENTRAL NYS. THIS LINE HAS WEAKENED SOME IN THE PAST
HOUR OR SO...WITH VERY LITTLE LIGHTNING ASSOCIATED WITH IT. THE
01/20Z HRRR LOOKS TO BE ON TRACK WITH WHAT IS HAPPENING CURRENTLY
AND WAS USED IN A BLEND WITH THE PREVIOUS FORECAST FOR THE POPS
OVERNIGHT.
PREVIOUS DISCUSSION...
A MID LEVEL SHORTWAVE MOVES EAST FROM MI INTO NEW ENG OVERNIGHT
AND COMBINED WITH INCREASED CONVERGENCE FROM THE LOW LEVEL JET AND
ELEVATED INSTABILITY WILL BRING WIDESPREAD SHOWERS AND SCT TSTMS
TO SNE TONIGHT. PWATS INCREASE TO 1.75-2" SO LOCALLY HEAVY
RAINFALL AND AREAS OF URBAN AND POOR DRAINAGE FLOODING WILL BE THE
PRIMARY THREAT. HOWEVER...MODELS ARE GENERATING SOME SFC
INSTABILITY TONIGHT..ESPECIALLY NEAR THE COAST AS THE MID LEVELS
COOL AND THERE IS MODEST 0-1KM SHEAR MOVING THROUGH WITH
INCREASING 0-6KM SHEAR MOVING IN FROM THE WEST...SO WILL HAVE TO
MONITOR RADAR TRENDS CLOSELY FOR STRONGER CONVECTION LATER
TONIGHT.
FOCUS FOR CONVECTION WILL SHIFT TO EASTERN NEW ENG 06-12Z WITH
SOME CLEARING POSSIBLE ACROSS THE CT VALLEY TOWARD 12Z.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
LINGERING CONVECTION ACROSS EASTERN NEW ENG EARLY FRI WILL END AS
THE SHORTWAVE LIFTS TO THE NE AND THE FRONT MOVES OFF THE COAST.
GENERALLY LOOKING AT A DRY DAY WITH SCT-BKN CU DEVELOPING...HOWEVER
CANT COMPLETELY RULE OUT A SPOT SHOWER IN THE AFTERNOON AS THERE
IS MARGINAL INSTABILITY AND ANOTHER SHORTWAVE APPROACHES FROM
THE WEST. 850 MB TEMPS 13-14C SO IT WILL BE A WARM DAY WITH MAXES
LOW TO MID 80S...BUT COOLER HIGHER TERRAIN. HUMID IN THE
MORNING...ESPECIALLY E NEW ENG BUT DEWPOINTS WILL BE FALLING IN
THE AFTERNOON.
FRIDAY NIGHT...
YET ANOTHER SHORTWAVE WILL BE APPROACHING NEW ENG FROM THE GT
LAKES. MODELS DIFFER ON LOCATION AND COVERAGE OF SHOWERS LATE FRI
NIGHT...SO CONFIDENCE IS LOW BUT WE HAVE CHC POPS IN W NEW ENG.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* MOSTLY DRY...SEASONABLE TO SEASONABLY COOL WEATHER
* FEW SHOWERS POSSIBLE SATURDAY...SUNDAY...AND TUESDAY
* NEXT CHANCE OF WIDESPREAD RAIN WED INTO THU
MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THIS WEEKEND THEN BEGIN
TO DIVERGE INTO EARLY NEXT WEEK. THE 01/00Z ECMWF INDICATES A MORE
ZONAL FLOW BETWEEN RIDGING TO THE SOUTH AND TROUGHING ACROSS
SOUTHERN CANADA WITH HIGH PRESSURE TO START THE WEEK. THIS RUN OF
THE ECMWF ALSO KEEPS A COASTAL LOW DEVELOPING OVER THE CAROLINAS AND
MOVING TO THE NORTHEAST TUESDAY AND THEN OUT TO SEA WEDNESDAY. THE
01/12Z GFS ON THE OTHER HAND DEVELOPS A BROAD TROUGH OVER THE
NORTHEAST WITH WESTERLY OR NORTHWESTERLY FLOW OVER SOUTHERN NEW
ENGLAND AND A COLD FRONT MOVING SLOWLY ACROSS SOUTHERN NEW ENGLAND
TUE AND WED. THE ECMWF HAS BEEN MORE CONSISTENT FROM RUN TO RUN SO
AM LEANING TOWARDS THAT SOLUTION WITH THE GREATEST THREAT OF
WIDESPREAD RAIN WEDNESDAY AND THURSDAY WITH A FEW SHOWERS POSSIBLE
SATURDAY...SUNDAY...AND TUESDAY.
SATURDAY AND SUNDAY...LOW PRESSURE IN QUEBEC BRINGS A WEAK COLD
FRONT THROUGH SOUTHERN NEW ENGLAND SATURDAY. WHILE THERE IS A LOW
PROBABILITY OF A FEW STRONG THUNDERSTORMS SATURDAY...THE TIMES OF
GREATEST SHEAR...INSTABILITY AND LIFT WITH THE FRONT ARE NOT ALIGNED
WELL SO EXPECTING MORE ALONG THE LINES OF SHOWERS AHEAD OF THE FRONT
WITH AN ISOLATED THUNDERSTORM OR TWO SATURDAY. HIGH PRESSURE STARTS
BUILDING INTO THE REGION SUNDAY BUT WITH A SHORTWAVE MOVING ACROSS
SOUTHERN NEW ENGLAND...A FEW DIURNAL SHOWERS ARE POSSIBLE SUNDAY AS
WELL. HAVE SLIGHT CHANCE TO CHANCE POPS ACROSS MUCH OF SOUTHERN NEW
ENGLAND DURING THIS TIME. OTHERWISE...EXPECT TEMPERATURES TO BE
RIGHT AROUND TO JUST BELOW NORMAL WITH PARTLY TO MOSTLY CLOUDY SKIES
DURING THE DAY.
MONDAY...HIGH PRESSURE MOVES OVER SOUTHERN NEW ENGLAND BRINGING
MOSTLY DRY WEATHER AND BELOW NORMAL TEMPS FOR EARLY AUGUST.
TUESDAY THROUGH THURSDAY...THIS IS WHERE THE MOST UNCERTAINTY IS IN
THIS FORECAST. THE GFS AND THE ECMWF HAVE FAIRLY DIFFERENT
SOLUTIONS. THE GFS BRINGS A COLD FRONT THROUGH SOUTHERN NEW ENGLAND
TUESDAY NIGHT INTO WEDNESDAY AND THE ECMWF KEEPS HIGH PRESSURE
DOMINANT OVER THE REGION WHILE A LOW PRESSURE SYSTEM MOVES UP TO THE
DELMARVA REGION FROM THE CAROLINAS AND THEN EASTWARD OUT TO SEA
DURING THE SAME TIME FRAME. THEN THURSDAY ON THE ECMWF...A PAIR OF
LOW PRESSURE SYSTEMS APPROACH SOUTHERN NEW ENGLAND BRINGING A
POSSIBILITY OF RAIN WHILE THE GFS BUILDS HIGH PRESSURE INTO THE
REGION. OVERALL THIS IS A FAIRLY UNSETTLED AND UNCERTAIN PATTERN
FOR THE MIDDLE OF NEXT WEEK. AS STATED ABOVE...LEANED MORE TOWARDS
THE MORE CONSISTENT ECMWF FOR THIS FORECAST...BUT WILL HAVE TO SEE
WHAT THE MODELS DO IN THE COMING DAYS.
&&
.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE IN TRENDS THROUGH FRI...BUT LOWER CONFIDENCE IN
TIMING.
EXPECT LOWERING CONDITIONS THROUGH TONIGHT AS SHOWERS OVERSPREAD
THE REGION. WIDESPREAD MVFR WITH AREAS OF IFR DEVELOPING TONIGHT.
LOCALLY HEAVY RAIN IS POSSIBLE WITH THESE SHOWERS. IMPROVING
CONDITIONS LATE TONIGHT IN THE CT VALLEY WITH MORE WIDESPREAD
SHOWERS IN THE EAST 06-12Z.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR FROM WEST TO EAST DURING
FRIDAY...BUT NOT UNTIL THE AFTERNOON FOR THE CAPE/ISLANDS.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
TIMING. MVFR POSSIBLE IN SHOWERS DEVELOPING TONIGHT AND CANT RULE
OUT A PERIOD OF IFR CIGS...IMPROVING TO VFR FRIDAY MORNING.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
TIMING. MVFR IN SHOWERS DEVELOPING THIS EVENING...THEN IMPROVING
LATE TONIGHT. AREAS OF IFR POSSIBLE BUT CONFIDENCE IS NOT HIGH.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY AND SUNDAY...MODERATE TO HIGH CONFIDENCE. MAINLY VFR.
LOW PROBABILITY OF BRIEF MVFR/IFR CONDITIONS IN ISOLATED TO
SCATTERED SHOWERS.
MONDAY...HIGH CONFIDENCE. VFR.
TUESDAY...MODERATE CONFIDENCE. LIKELY VFR. LOW PROBABILITY OF
BRIEF MVFR/IFR CONDITIONS IN SCT SHRA.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
WINDS EXPECTED TO REMAIN BELOW SCA THRESHOLDS THROUGH FRI NIGHT.
GUSTS TO 20 KT POSSIBLE TONIGHT AS THE LOW LEVEL JET MOVES
THROUGH...WITH ANOTHER PULSE OF W/SW G20 KT FRI AFTERNOON AS LOW
LEVEL WINDS INCREASE. SEAS SHOULD REMAIN BELOW 5 FT THROUGH MUCH
OF FRI...BUT ARE EXPECTED TO BUILD TO 5 FT OVER SOUTHERN WATERS
LATE FRI AND ESPECIALLY FRI NIGHT.
OUTLOOK...SATURDAY THROUGH TUESDAY...
HIGH CONFIDENCE. MOSTLY QUIET BOATING WEATHER EXPECTED THROUGH
THIS WEEKEND INTO EARLY NEXT WEEK. LOW PROBABILITY OF SEAS UP TO 5
FEET ON THE OUTER WATERS AT TIMES SATURDAY AND SUNDAY. MAINLY
WESTERLY WINDS WILL REMAIN BELOW 25 KTS FOR THE MOST PART SHIFTING
TO THE SOUTHWEST OR NORTHWEST AT TIMES THROUGH THE PERIOD.
SATURDAY...A FEW GUSTS NEAR 25 KTS ON THE NEAR SHORE WATERS ALONG
THE SOUTH COAST.
&&
.CLIMATE...
THESE ARE THE LATEST STANDINGS FOR THE JULY AVERAGE TEMPERATURE.
ALL 4 OF THE MAJOR CLIMATE SITES FINISHED IN THE TOP 5.
BOSTON /LOGAN AIRPORT/
1. 78.0 IN 1983
2. 77.5 IN 1994 AND 1952
3. 77.3 IN 2011
4. 77.2 IN 2010 AND 1955
5. 77.1 IN 2013 AND 1911
PROVIDENCE /TF GREEN AIRPORT/
1. 78.4 IN 2013
2. 77.5 IN 2010
3. 76.6 IN 1983
4. 76.5 IN 1999
5. 76.4 IN 2008
HARTFORD/WINDSOR LOCKS /BRADLEY/
1. 77.9 IN 2013
2. 77.1 IN 2010 AND 1994
3. 77.0 IN 1955
4. 76.8 IN 1949
5. 76.5 IN 2006...1999 AND 1995
WORCESTER /AIRPORT/
1. 75.9 IN 1911
2. 74.3 IN 1952 AND 1901
3. 74.2 IN 1949
4. 74.1 IN 2013
5. 74.0 IN 2010
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KJC/RLG
NEAR TERM...KJC/RLG
SHORT TERM...KJC
LONG TERM...RLG
AVIATION...KJC/RLG
MARINE...KJC/RLG
CLIMATE...STAFF
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
910 PM EDT THU AUG 1 2013
.UPDATE...OUTFLOW FROM STORMS IN INTERIOR HAVE REACHED POCKETS OF
INSTABILITY NEAR THE COAST AS THESE AREAS DID NOT SEE MANY AFTN
STORMS. INSTABILITY IS ALSO AIDED BY WARM GULF INFLUENCE AND LAPS
SHOWS CAPE STILL IN 3K RANGE AROUND TAMPA BAY. STORMS HAVE RE-
IGNITED ON QUE ALONG THE BOUNDARY IN LAST HALF HOUR. SENDING OUT QUICK
UPDATE TO INCREASE POPS ALONG THE COAST AND OFFSHORE.
&&
.PREV DISCUSSION... /ISSUED 756 PM EDT THU AUG 1 2013/
UPDATE...MESO SCALE MODELS DID A GOOD JOB SHOWING CONVECTION
DEVELOPING ALONG SEA BREEZE COLLISIONS FROM NEAR CLERMONT TO BARTOW
AND SOUTH TO FMY AREA. HAD A COUPLE STORMS THAT WE WERE ONE SCAN
AWAY FROM ISSUING SVRS WITH NICE CORES PUSHED ALOFT...BUT THEY ALL
WOULD WEAKEN AT THAT POINT. HRRR ESPECIALLY DID A GOOD JOB
HANDLING THIS EVENINGS CONVECTION EARLIER IN THE DAY BUT SEEMS TO
BE A BIT BIASES TO THE WEST LAST FEW HOURS. EVEN SO...THE HRRR DOES NOT
SHOW THE STORMS REACHING THE COAST THIS EVENING...ALTHOUGH THE
OUTFLOW BOUNDARY DOES PUSH OFFSHORE. WILL CONTINUE TO KEEP POPS
OUT OF THE FORECAST NEAR THE COAST FOR CEN/NRN AREAS...BUT WILL
WATCH THIS CLOSELY AS THERE MAY BE ENOUGH REMAINING INSTABILITY TO
SPARK A STORM OR TWO AROUND THE TAMPA BAY AREA. IF STORMS WIND
DOWN ON SCHEDULE...ONLY UPDATE REQUIRED LATER THIS EVENING WILL BE
TO DECREASE AND/OR REMOVE POPS FOR MOST LAND AREAS. THAT
SAID...LOW POPS WILL REMAIN ACROSS THE WATERS GIVEN AS WELL AS
PORTIONS OF THE NATURE COAST GIVEN STRONGER ONSHORE WINDS IN THAT
AREA.
AVIATION...OTHER THAN NEAR SHRA AND TSRA...MVFR CIGS/VIS NOT
ANTICIPATED. TYPICAL FLORIDA SUMMER PATTERN WILL CONTINUE WITH SCT
AFTN AND EVENING TSTMS. MAIN CLUSTERS OF TSTMS EXTEND FROM FMY TO
LAL ALONG SEA BREEZE COLLISIONS THIS EVENING. STORMS DISSIPATING
NEAR SRN SITES SO MAIN CONCERN IN LAL AP THIS EVENING. THERE IS
AN OUTSIDE CHC THAT OUTFLOWS FROM STORMS TO THE EAST WILL GENERATE
SOMETHING NEAR TAMPA BAY AREA SITES BETWEEN NOW AND LATE
EVENING...BUT HIGH RESOLUTION MODELS NOT PICKING UP ON THAT
OCCURRING...SO DID NOT MENTION IN TAFS. MAY ALSO LEAST GET A WIND
SHIFT TO THE EAST BRIEFLY BEFORE GOING VRB OVERNIGHT...BUT GIVEN
WEAK WIND SPEEDS (LESS THAN 10 KNOTS HAVE NOT INCLUDED THIS IN THE
TAFS. TOMORROW...EXPECT EARLIER START TO THE TSTMS GIVEN A MORE
WRLY LOW LEVEL FLOW. THIS ALSO MEANS HIGHER PRECIP CHCS WILL BE
INLAND ON FRI. HAVE ACCOUNTED THIS IN TIMING SHOWN IN THE VCTS IN
00Z TAFS.
PREV DISCUSSION... /ISSUED 219 PM EDT THU AUG 1 2013/
SHORT TERM (TONIGHT - SATURDAY)...AS EXPECTED...THE DEEP-LAYERED
RIDGE HAS WEAKENED ENOUGH TO ALLOW AN EARLIER AND MORE PROGRESSIVE
WEST COAST SEA BREEZE TO DEVELOP. THE SEA BREEZE HAS ALREADY MOVED
WELL INLAND OVER THE NATURE COAST AND IS PUSHING THROUGH PINELLAS
COUNTY AT THIS TIME. SCATTERED STORMS...SOME STRONG WILL ACCOMPANY
THE PASSAGE OF THE BOUNDARY. EXPECT MUCH OF THE THUNDERSTORM
ACTIVITY TO BE EAST OF I-75 FROM THE TAMPA BAY AREA NORTHWARD BY
LATE AFTERNOON.
MODELS ARE IN GOOD AGREEMENT NOW IN TAKING THE MID-LEVEL LOW...ONCE
PART OF TROPICAL STORM DORIAN...NORTHWARD ALONG OR EAST OF THE
FLORIDA EAST COAST TONIGHT THROUGH FRIDAY NIGHT. THIS IS A SMALL AND
WEAK SYSTEM AND IS NOT EXPECTED TO HAVE A SIGNIFICANT IMPACT ON OUR
WEATHER HERE IN WEST-CENTRAL FLORIDA.
SO FOR FRIDAY...MAIN AXIS OF SEA BREEZE STORMS SHOULD LINE UP EAST
OF I-75 FOR MOST OF THE REGION BUT MAY BE CLOSER TO THE COAST IN
CHARLOTTE AND LEE COUNTIES WHERE THE EASTERLIES ARE A BIT STRONGER.
WENT WELL ABOVE MAV GUIDANCE NUMBERS WITH 30 TO 40 PERCENT RAIN
CHANCES ALONG THE COAST AND 50 PERCENT INLAND.
ON SATURDAY...THE LOW-LEVEL RIDGE AXIS SLIPS A BIT MORE TO THE SOUTH
BUT EXPECT LITTLE CHANGE IN OUR WEATHER OVERALL. BEST RAIN CHANCES
WILL STILL BE EAST OF I-75 AS SEA BREEZES PUSH INLAND BY
MID-AFTERNOON.
LONG TERM (PREVIOUS DISCUSSION SATURDAY NIGHT - THURSDAY)...
THE LONG TERM FORECAST CONTINUES TO FEATURE A WET SUMMER PATTERN
FOR MUCH OF FLORIDA. THE SURFACE ATLANTIC RIDGE OF HIGH PRESSURE
REMAINS IN SOME FORM OVER THE AREA...USHERING IN MOIST AIR. AT THE
500 MB LEVEL...A TROUGH HOLDS STEADY OVER THE EASTERN UNITED
STATES. COMBINE THESE SYNOPTIC FEATURES WITH THE AFTERNOON SEA
BREEZE AND ANY POTENTIAL TROPICAL MOISTURE SOURCES...AND YOU HAVE
A NORMAL FLORIDA SUMMER PATTERN. TEMPERATURE AND POP FORECAST
BASED OFF THE MEX/GFS WITH SOME CLIMO INFLUENCES.
AVIATION...
WEST COAST SEABREEZE CONVECTION FROM THE TAMPA BAY AREA
NORTHWARD TO MOVE INLAND SHORTLY WITH VCTS AROUND NORTHERN TAF SITES
UNTIL 20Z-22Z. CENTRAL AND SW FL TAF SITES...EXPECT EAST AND WEST
COAST SEABREEZE CONVERGENCE TO PRODUCE SCT TSRA FROM AROUND 20Z-24Z
FOR REDUCED CIGS/VSBYS AND GUSTY WINDS AT OR NEAR TERMINALS. VFR
CONDITIONS TO RETURN ALL AREAS AFTER 00Z THROUGH THE NIGHT.
MARINE...SURFACE RIDGE AXIS WILL STAY OVER THE WATERS THROUGH
SATURDAY THEN BEGIN A SLOW SHIFT SOUTHWARD EARLY NEXT WEEK. THE
PRESSURE GRADIENT NORTH OF THE RIDGE AXIS DOES NOT GET
PARTICULARLY STRONG SO WINDS WILL LIKELY STAY BELOW 15 KNOTS AND
SEAS MAINLY 2 FEET OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 77 91 78 92 / 40 40 10 40
FMY 74 93 75 93 / 40 50 10 40
GIF 75 94 74 94 / 30 50 20 50
SRQ 74 90 76 92 / 40 40 10 30
BKV 72 93 72 93 / 20 50 10 40
SPG 77 93 78 92 / 40 40 10 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/MARINE/FIRE WEATHER...88/GITTINGER
LONG TERM/AVIATION...88/GITTINGER
AREA FORECAST DISCUSSION
NWS MIAMI FL
811 PM EDT THU AUG 1 2013
.UPDATE...
SHOWERS AND THUNDERSTORMS HAVE BECOME MOSTLY CONFINED TO THE WEST
COAST AND ADJACENT WATERS. THERE ARE SOME ISOLATED SHOWERS OVER
THE ATLANTIC WATERS AS WELL. THE HRRR CONTINUES TO SHOW ISOLATED
TO SCATTERED ACTIVITY THROUGH THE OVERNIGHT HOURS OVER THE
ATLANTIC WATERS. IT ALSO SHOWS THE SHOWERS, AND OR ANY
THUNDERSTORMS, WEAKENING AS THEY MOVE ONSHORE. POPS HAVE BEEN
ADJUSTED SOMEWHAT TO REFLECT THIS PATTERN.
.AVIATION...
HIGHER THAN USUAL DEGREE OF UNCERTAINTY IN THE 0Z TAF
ISSUANCES...AS THE FORECAST WILL BE IMPACTED BY THE EVOLUTION OF
THE REMNANTS OF TROPICAL STORM DORIAN. THESE REMNANTS BECAME MORE
CONCENTRATED THIS AFTERNOON...THEN DIMINISHED THIS EVENING OVER
THE NORTHWEST BAHAMAS. GUIDANCE HAS THE SYSTEM CONTINUING
NORTHWEST OVERNIGHT...GRADUALLY TURNING NORTHWARD FRIDAY. THE NAM
TAKES CONVECTION ASSOCIATED WITH THE REMNANTS ONSHORE...WHEREAS
OTHER MODELS KEEP THE MOST ROBUST PRECIPITATION OVER ATLANTIC
WATERS...WITH ONLY SCATTERED ACTIVITY ON LAND. EVEN FOR
TONIGHT...SHOWERS IN THE WESTERN-MOST BAHAMAS ARE MOVING TOWARD
SOUTH FLORIDA...AND GUIDANCE OFFERS LITTLE CONSENSUS ON WHETHER
THEY WILL HOLD TOGETHER.
LATEST TAFS KEEP VCSH THROUGH THE OVERNIGHT AND INTO
TOMORROW...BUT DID NOT CALL FOR INCREASING ACTIVITY OR VCTS FOR
FRIDAY AFTERNOON...DUE TO THE AFOREMENTIONED CONFIDENCE ISSUES.
WINDS SHOULD GENERALLY BE SOUTH OF EAST...BUT IF DORIANS REMNANTS
ARE FAIRLY ORGANIZED...WINDS ARE LIKELY TO BACK TO THE NORTHEAST
ON FRIDAY. SPEEDS SHOULD BE LESS THAN 15 KTS REGARDLESS OF THEIR
DIRECTION...EXCEPT IN AN NEAR PRECIPITATION.
&&
.PREV DISCUSSION... /ISSUED 248 PM EDT THU AUG 1 2013/
..MAIN IMPACTS FROM BAHAMAS LOW PRESSURE SYSTEM EXPECTED TO REMAIN
MOSTLY OFFSHORE...
DISCUSSION...
LOW PRESSURE SYSTEM OVER THE BAHAMAS CONTAINING THE REMNANTS OF
DORIAN HAVE BECOME MORE CONCENTRATED TODAY AS IT MOVES NORTHWEST.
SOUTH FLORIDA APPEARS TO BE UNDER A REGION OF UPPER-LEVEL
SUBSIDENCE AND ASSOCIATED DRIER AIR WHICH IS LIMITING THE
DEVELOPMENT OF THE CONVECTION OVER THE PENINSULA SO FAR THIS
AFTERNOON. IN FACT, SATELLITE IMAGERY IS SHOWING SEVERAL ARC-
SHAPED CLOUD PATTERNS SPREADING WESTWARD OVER THE WATERS OFF THE SE
FLORIDA COAST FROM THE CLUSTER OF STORMS OVER THE BAHAMAS...A
USUAL SIGN OF SUBSIDENCE PREVENTING CONVECTION FROM GETTING
ORGANIZED OR VERY STRONG AS THESE SHOWERS APPROACH THE FLORIDA
COAST. FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING,
GREATEST COVERAGE OF SHOWERS/TSTMS WILL BE OVER THE INTERIOR IN
A TYPICAL EAST FLOW PATTERN
MODELS APPEAR TO HAVE A DECENT HANDLE ON THE LOW PRESSURE AREA AND
ARE REASONABLY CONSISTENT IN KEEPING THE BULK OF THE ASSOCIATED
WEATHER OFFSHORE TONIGHT AND FRIDAY. THE GFS IS THE ONLY MODEL
WHICH BRINGS THE LOW LEVEL CIRCULATION (850 MB) ONSHORE THE EAST
COAST LATE TONIGHT AND EARLY FRIDAY, WITH THE NAM AND ECMWF
KEEPING IT OFFSHORE OVER THE STRAITS. DUE TO THE UNCERTAINTY IN
THE LOCATION OF THE LOW LEVEL CIRCULATION AND HOW CLOSE IT MAY
COME TO THE EAST COAST, WILL INDICATE SCT TSTMS (30%) FOR EAST
COAST LATE TONIGHT DESPITE MODELS NOT BEING ENTHUSIASTIC ABOUT
PRECIPITATION COVERAGE. THE LOW IS EXPECTED TO MOVE NORTH NEAR OR
JUST OFF THE COAST FRIDAY ALONG THE WESTERN PERIPHERY OF THE
ATLANTIC SUBTROPICAL RIDGE. AS MENTIONED ABOVE, THIS WOULD KEEP
MOST OF THE ASSOCIATED SHOWERS/TSTMS/GUSTY WINDS OFFSHORE, BUT A
GENERAL INCREASE IN MOISTURE ACROSS SOUTH FLORIDA ALONG WITH THE
PRESENCE OF A LOW/MID LEVEL TROUGH WILL LEAD TO SCATTERED MAINLY
AFTERNOON TSTMS. VERY HEAVY RAINFALL AND MINOR FLOODING ARE THE
MAIN THREATS WITH THE STORMS ON FRIDAY DUE TO THE EXPECTED SLOW
STORM MOTION.
FOR THE WEEKEND...THE LOW PRESSURE IS FORECAST TO MOVE NORTH OF THE
AREA FRIDAY NIGHT, LEAVING BEHIND A BUILDING LOW/MID LEVEL RIDGE
OVER SOUTH FLORIDA. THE ORIENTATION OF THE RIDGE RIGHT OVER SOUTH
FLORIDA WILL LEAD TO LIGHT SW/W WINDS AND FOCUS SCATTERED AFTERNOON
TSTMS TO THE INTERIOR/LAKE OKEECHOBEE AND PALM BEACH COUNTY AREAS
ON SATURDAY, AND GENERALLY INTERIOR AND EAST ON SUNDAY. TEMPERATURES
WILL ALSO BE ON THE RISE, PARTICULARLY THE DAYTIME HIGHS INTERIOR
AND EAST. SUNDAY COULD SEE HIGHS IN THE LOW/MID 90S EVEN INTO
PARTS OF THE EAST COAST METRO WITH MAXIMUM HEAT INDEX VALUES
100-105F JUST ABOUT EVERYWHERE, WITH ISOLATED POCKETS OF 105-109F
POSSIBLE IN THE EVERGLADES.
THE WEEKEND PATTERN LOOKS TO REMAIN IN PLACE INTO EARLY NEXT WEEK,
WITH HOT TEMPERATURES AND AFTERNOON TSTMS FOCUSING INTERIOR AND
EAST. BY WEDNESDAY, MODELS SHOW SOME DIFFERENCES WITH THE GFS
SHOWING EASTERLY FLOW RETURNING AND THE ECMWF SHOWING A LINGERING
LOW/MID LEVEL LOW OVER THE EASTERN GULF OF MEXICO. THE ECMWF
SCENARIO IS WETTER/STORMIER THAN THE GFS FOR MIDDLE OF NEXT WEEK,
BUT STILL PLENTY OF TIME TO EVALUATE TRENDS.
AVIATION...
FOR THIS AFTERNOON...BANDS OF SHOWERS WILL CONTINUE TO MOVE WESTWARD
ACROSS THE ATLANTIC WATERS AND AFFECT THE EAST COAST TAF SITES FROM
TIME TO TIME BUT MAINLY VFR CONDITIONS ARE EXPECTED TO
PREVAIL...ALTHOUGH AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT. FOR
TERMINAL KAPF...VCTS IS ASSIGNED BY 19Z WITH PERIODS OF SUB-VFR
CONDITIONS POSSIBLE AND VERY BRIEF PERIODS OF IFR CONDITIONS
POSSIBLE WITH THE OCCURRENCE OF SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN PENINSULA THIS AFTERNOON AND EARLY EVENING.
FOR TONIGHT INTO FRIDAY...THE COMBINATION OF THE REMNANTS OF DORIAN
AND AN UPPER LOW MOVING IN TANDEM WITH IT HAS CREATED A SURFACE
TROUGH AND AN AREA OF CLOUDINESS ACROSS THE CENTRAL AND NORTHWEST
BAHAMAS...WITH SHOWERS AND THUNDERSTORMS IN THESE AREAS. ALTHOUGH
THE LOW PRESSURE AND ASSOCIATED CONVECTION IS FORECAST TO REMAIN
TO THE EAST OF SOUTH FLORIDA THROUGH THE TAF PERIOD...BANDS OF
SHOWERS WILL CONTINUE TO AFFECT THE EAST COAST TAF SITES TONIGHT
INTO FRIDAY WITH ALL EAST COAST TERMINALS ASSIGNED VCSH THROUGH
THIS PERIOD.
MARINE...
MODERATE EASTERLY WINDS TODAY WILL DECREASE TONIGHT AND BECOME
S/SW AS THE LOW PRESSURE AREA MOVES NEAR THE LOCAL ATLANTIC
WATERS. UNLESS THE SYSTEM DEVELOP, WHICH IS A LOW POSSIBILITY AT
THIS TIME, WINDS WILL REMAIN LIGHT WITH THE PRIMARY CONCERN BEING
GUSTY WINDS IN AND NEAR THE SHOWERS/TSTMS OVER THE ATLANTIC. THE
LIGHT S/SW FLOW WILL CONTINUE THROUGH THE UPCOMING WEEKEND AND
LIKELY INTO EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 89 78 91 / 30 50 30 40
FORT LAUDERDALE 77 89 77 91 / 30 50 30 30
MIAMI 77 90 77 91 / 20 50 30 30
NAPLES 75 90 76 91 / 30 40 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...23/SK
AREA FORECAST DISCUSSION...UPDATED
NWS TAMPA BAY RUSKIN FL
756 PM EDT THU AUG 1 2013
.UPDATE...MESO SCALE MODELS DID A GOOD JOB SHOWING CONVECTION
DEVELOPING ALONG SEA BREEZE COLLISIONS FROM NEAR CLERMONT TO BARTOW
AND SOUTH TO FMY AREA. HAD A COUPLE STORMS THAT WE WERE ONE SCAN
AWAY FROM ISSUING SVRS WITH NICE CORES PUSHED ALOFT...BUT THEY ALL
WOULD WEAKEN AT THAT POINT. HRRR ESPECIALLY DID A GOOD JOB
HANDLING THIS EVENINGS CONVECTION EARLIER IN THE DAY BUT SEEMS TO
BE A BIT BIASES TO THE WEST LAST FEW HOURS. EVEN SO...THE HRRR DOES NOT
SHOW THE STORMS REACHING THE COAST THIS EVENING...ALTHOUGH THE
OUTFLOW BOUNDARY DOES PUSH OFFSHORE. WILL CONTINUE TO KEEP POPS
OUT OF THE FORECAST NEAR THE COAST FOR CEN/NRN AREAS...BUT WILL
WATCH THIS CLOSELY AS THERE MAY BE ENOUGH REMAINING INSTABILITY TO
SPARK A STORM OR TWO AROUND THE TAMPA BAY AREA. IF STORMS WIND
DOWN ON SCHEDULE...ONLY UPDATE REQUIRED LATER THIS EVENING WILL BE
TO DECREASE AND/OR REMOVE POPS FOR MOST LAND AREAS. THAT
SAID...LOW POPS WILL REMAIN ACROSS THE WATERS GIVEN AS WELL AS
PORTIONS OF THE NATURE COAST GIVEN STRONGER ONSHORE WINDS IN THAT
AREA.
&&
.AVIATION...OTHER THAN NEAR SHRA AND TSRA...MVFR CIGS/VIS NOT
ANTICIPATED. TYPICAL FLORIDA SUMMER PATTERN WILL CONTINUE WITH SCT
AFTN AND EVENING TSTMS. MAIN CLUSTERS OF TSTMS EXTEND FROM FMY TO
LAL ALONG SEA BREEZE COLLISIONS THIS EVENING. STORMS DISSIPATING
NEAR SRN SITES SO MAIN CONCERN IN LAL AP THIS EVENING. THERE IS
AN OUTSIDE CHC THAT OUTFLOWS FROM STORMS TO THE EAST WILL GENERATE
SOMETHING NEAR TAMPA BAY AREA SITES BETWEEN NOW AND LATE
EVENING...BUT HIGH RESOLUTION MODELS NOT PICKING UP ON THAT
OCCURRING...SO DID NOT MENTION IN TAFS. MAY ALSO LEAST GET A WIND
SHIFT TO THE EAST BRIEFLY BEFORE GOING VRB OVERNIGHT...BUT GIVEN
WEAK WIND SPEEDS (LESS THAN 10 KNOTS HAVE NOT INCLUDED THIS IN THE
TAFS. TOMORROW...EXPECT EARLIER START TO THE TSTMS GIVEN A MORE
WRLY LOW LEVEL FLOW. THIS ALSO MEANS HIGHER PRECIP CHCS WILL BE
INLAND ON FRI. HAVE ACCOUNTED THIS IN TIMING SHOWN IN THE VCTS IN
00Z TAFS.
&&
.PREV DISCUSSION... /ISSUED 219 PM EDT THU AUG 1 2013/
SHORT TERM (TONIGHT - SATURDAY)...AS EXPECTED...THE DEEP-LAYERED
RIDGE HAS WEAKENED ENOUGH TO ALLOW AN EARLIER AND MORE PROGRESSIVE
WEST COAST SEA BREEZE TO DEVELOP. THE SEA BREEZE HAS ALREADY MOVED
WELL INLAND OVER THE NATURE COAST AND IS PUSHING THROUGH PINELLAS
COUNTY AT THIS TIME. SCATTERED STORMS...SOME STRONG WILL ACCOMPANY
THE PASSAGE OF THE BOUNDARY. EXPECT MUCH OF THE THUNDERSTORM
ACTIVITY TO BE EAST OF I-75 FROM THE TAMPA BAY AREA NORTHWARD BY
LATE AFTERNOON.
MODELS ARE IN GOOD AGREEMENT NOW IN TAKING THE MID-LEVEL LOW...ONCE
PART OF TROPICAL STORM DORIAN...NORTHWARD ALONG OR EAST OF THE
FLORIDA EAST COAST TONIGHT THROUGH FRIDAY NIGHT. THIS IS A SMALL AND
WEAK SYSTEM AND IS NOT EXPECTED TO HAVE A SIGNIFICANT IMPACT ON OUR
WEATHER HERE IN WEST-CENTRAL FLORIDA.
SO FOR FRIDAY...MAIN AXIS OF SEA BREEZE STORMS SHOULD LINE UP EAST
OF I-75 FOR MOST OF THE REGION BUT MAY BE CLOSER TO THE COAST IN
CHARLOTTE AND LEE COUNTIES WHERE THE EASTERLIES ARE A BIT STRONGER.
WENT WELL ABOVE MAV GUIDANCE NUMBERS WITH 30 TO 40 PERCENT RAIN
CHANCES ALONG THE COAST AND 50 PERCENT INLAND.
ON SATURDAY...THE LOW-LEVEL RIDGE AXIS SLIPS A BIT MORE TO THE SOUTH
BUT EXPECT LITTLE CHANGE IN OUR WEATHER OVERALL. BEST RAIN CHANCES
WILL STILL BE EAST OF I-75 AS SEA BREEZES PUSH INLAND BY
MID-AFTERNOON.
LONG TERM (PREVIOUS DISCUSSION SATURDAY NIGHT - THURSDAY)...
THE LONG TERM FORECAST CONTINUES TO FEATURE A WET SUMMER PATTERN
FOR MUCH OF FLORIDA. THE SURFACE ATLANTIC RIDGE OF HIGH PRESSURE
REMAINS IN SOME FORM OVER THE AREA...USHERING IN MOIST AIR. AT THE
500 MB LEVEL...A TROUGH HOLDS STEADY OVER THE EASTERN UNITED
STATES. COMBINE THESE SYNOPTIC FEATURES WITH THE AFTERNOON SEA
BREEZE AND ANY POTENTIAL TROPICAL MOISTURE SOURCES...AND YOU HAVE
A NORMAL FLORIDA SUMMER PATTERN. TEMPERATURE AND POP FORECAST
BASED OFF THE MEX/GFS WITH SOME CLIMO INFLUENCES.
AVIATION...
WEST COAST SEABREEZE CONVECTION FROM THE TAMPA BAY AREA
NORTHWARD TO MOVE INLAND SHORTLY WITH VCTS AROUND NORTHERN TAF SITES
UNTIL 20Z-22Z. CENTRAL AND SW FL TAF SITES...EXPECT EAST AND WEST
COAST SEABREEZE CONVERGENCE TO PRODUCE SCT TSRA FROM AROUND 20Z-24Z
FOR REDUCED CIGS/VSBYS AND GUSTY WINDS AT OR NEAR TERMINALS. VFR
CONDITIONS TO RETURN ALL AREAS AFTER 00Z THROUGH THE NIGHT.
MARINE...SURFACE RIDGE AXIS WILL STAY OVER THE WATERS THROUGH
SATURDAY THEN BEGIN A SLOW SHIFT SOUTHWARD EARLY NEXT WEEK. THE
PRESSURE GRADIENT NORTH OF THE RIDGE AXIS DOES NOT GET
PARTICULARLY STRONG SO WINDS WILL LIKELY STAY BELOW 15 KNOTS AND
SEAS MAINLY 2 FEET OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 77 91 78 92 / 10 40 10 40
FMY 74 93 75 93 / 40 50 10 40
GIF 75 94 74 94 / 30 50 20 50
SRQ 74 90 76 92 / 20 40 10 30
BKV 72 93 72 93 / 10 50 10 40
SPG 77 93 78 92 / 10 40 10 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/MARINE/FIRE WEATHER...88/GITTINGER
LONG TERM/AVIATION...88/GITTINGER
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
205 PM EDT WED JUL 31 2013
.PREV DISCUSSION... /ISSUED 431 AM EDT WED JUL 31 2013/
SHORT TERM /TODAY THROUGH THURSDAY/...
RAIN ALREADY RETURNING TO THE AREA TODAY AS PERTURBATIONS MOVE
THROUGH THE UPPER LEVEL FLOW. MEDIUM RANGE AND HI RES MODELS ARE
IN AGREEMENT THAT THE CWA WILL SEE CONVECTION TODAY...HOWEVER
CONSIDERABLE DISAGREEMENT IN TERMS OF TIMING. WRF NMM SEEMS TO
HAVE A SURGE IN CONVECTION DURING THE MORNING THAN A LULL DURING
THE AFTERNOON. LOCAL WRF TENDS TO WEAKEN CONVECTION THIS
MORNING...DEVELOP ACROSS CENTRAL GEORGIA THIS AFTERNOON AND THEN
ACROSS THE NORTH DURING THE LATE AFTERNOON. HRRR CONTINUES TO
SHIFT THE CURRENT CONVECTION TO THE EAST AND THEN DEVELOP
CONVECTION ACROSS THE ENTIRE CWA AS THE AFTERNOON APPROACHES.
GIVEN ALL OF THIS AND MEDIUM RANGE MODELS...GOOD CONFIDENCE OF
HIGH POPS FOR TODAY...HOWEVER LOW CONFIDENCE IN TERMS OF TIMING.
FORECAST IS MOST CLOSELY IN LINE WITH THE HRRR.
FOR THE STORMS CURRENTLY ONGOING...MAIN CONCERN IS GUSTY WINDS. GFS
CAPE FORECAST LOOKS MORE REASONABLE TODAY...RATHER THAN LAST NIGHT
WHERE IT WAS GAPPING THE CWA WITH INSTABILITY. FORECAST CAPE VALUES
ARE AROUND 1500-2000 J/KG FOR THE AFTERNOON. STILL EXPECTING BETWEEN
20 AND 30KTS OF DEEP LAYER SHEAR TODAY AND BETWEEN THIS AND THE
INSTABILITY VALUES...COULD SEE ISOLATED SEVERE STORMS. MAIN THREAT
WILL BE DAMAGING WINDS. ALTHOUGH THE CWA HAS HAD A FEW DAYS WITHOUT
RAIN...ALLOWING US TO BE ABLE TO HANDLE MORE IN TERMS OF
RAINFALL...WILL STILL HAVE TO MONITOR RAINFALL AMOUNTS CLOSELY.
AROUND ONE TO ONE AND A HALF INCHES OF RAIN IS EXPECTED THROUGH
THURSDAY...WITH LOCALIZED HIGHER AMOUNTS POSSIBLE. 1HR FFG VALUES
ARE AROUND 2.5 TO 3.5 INCHES SO WE SHOULD BE ABLE TO HANDLE THESE
AMOUNTS...BUT THERE IS THE POTENTIAL FOR LOCALIZED FLOODING WITH
HIGHER RAINFALL VALUES.
SFC FRONT MOVES THROUGH CWA ON THURSDAY. CONVECTION SHOULD DECREASE
BY THURSDAY MORNING...BUT THEN INCREASE AGAIN ON THURSDAY ALONG AND
SOUTH OF THIS FRONT.
11
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AT THE BEGINNING OF THE PERIOD A WEAK FRONTAL BOUNDARY WILL BE
MOVING INTO CENTRAL GEORGIA. CONVECTION ASSOCIATED WITH THIS
BOUNDARY MAY BE ONGOING. EXPECT THIS CONVECTION TO BE ON A GENERAL
WEAKENING TREND THROUGH THE EVENING. AT THIS POINT FRIDAY LOOKS TO
BE THE BEST DAY FOR NO POPS ACROSS THE REGION AS WE WAIT FOR
NORTHWEST FLOW TO BRING US ANOTHER IMPULSE AND RAIN TO THE AREA.
MOISTURE ASSOCIATED WITH DORIAN SHOULD HELP IN INCREASE PWATS AND
RAIN CHANCES THIS WEEKEND AND INTO NEXT WEEK. THE MODELS SUGGEST
THAT WE KEEP NORTHWEST FLOW THROUGH AT LEAST MID NEXT WEEK...WHEN
THEY TRY TO BUILD A RIDGE INTO THE SOUTHERN UNITED STATES. MAY
CONCERN IN THE EXTENDED COULD BE RAINFALL ASSOCIATED WITH THE
SHOWERS AND THUNDERSTORMS THIS WEEKEND AND INTO EARLY NEXT WEEK.
THIS WILL NEED TO BE MONITORED CLOSELY FOR POSSIBLE FLOODING AS WE
APPROACH THIS WEEKEND.
ARG
&&
.AVIATION...
18Z UPDATE...
WITH WIDESPREAD PRECIPITATION ONGOING ACROSS THE REGION WE ALREADY
HAVE A WIDE MIXTURE OF IFR TO VFR CONDITIONS. THIS SHOULD CONTINUE
WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE
FORECAST AREA THROUGH AT LEAST 06Z. WIDESPREAD IFR CONDITIONS ARE
EXPECTED TO DEVELOP BY 06-10Z...LASTING THROUGH 12Z AND IMPROVING TO
MVFR ACROSS MOST OF THE AREA BY 14Z. WINDS HAVE BEEN SOMEWHAT
VARIABLE BUT SHOULD BEGIN TRENDING TOWARD SOUTHWESTERLY AND
EVENTUALLY WESTERLY OVERNIGHT.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 69 88 68 / 70 60 30 20
ATLANTA 84 71 87 70 / 80 60 30 10
BLAIRSVILLE 77 66 83 62 / 90 60 20 10
CARTERSVILLE 85 69 88 66 / 80 60 20 10
COLUMBUS 88 72 91 72 / 70 70 50 30
GAINESVILLE 82 70 86 68 / 70 60 30 10
MACON 87 71 90 70 / 90 50 50 30
ROME 84 70 89 66 / 90 70 20 10
PEACHTREE CITY 84 70 87 66 / 90 50 30 20
VIDALIA 88 73 88 72 / 70 80 60 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....ARG
AVIATION...SNELSON
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
804 AM EDT WED JUL 31 2013
.PREV DISCUSSION... /ISSUED 431 AM EDT WED JUL 31 2013/
SHORT TERM /TODAY THROUGH THURSDAY/...
RAIN ALREADY RETURNING TO THE AREA TODAY AS PERTURBATIONS MOVE
THROUGH THE UPPER LEVEL FLOW. MEDIUM RANGE AND HI RES MODELS ARE
IN AGREEMENT THAT THE CWA WILL SEE CONVECTION TODAY...HOWEVER
CONSIDERABLE DISAGREEMENT IN TERMS OF TIMING. WRF NMM SEEMS TO
HAVE A SURGE IN CONVECTION DURING THE MORNING THAN A LULL DURING
THE AFTERNOON. LOCAL WRF TENDS TO WEAKEN CONVECTION THIS
MORNING...DEVELOP ACROSS CENTRAL GEORGIA THIS AFTERNOON AND THEN
ACROSS THE NORTH DURING THE LATE AFTERNOON. HRRR CONTINUES TO
SHIFT THE CURRENT CONVECTION TO THE EAST AND THEN DEVELOP
CONVECTION ACROSS THE ENTIRE CWA AS THE AFTERNOON APPROACHES.
GIVEN ALL OF THIS AND MEDIUM RANGE MODELS...GOOD CONFIDENCE OF
HIGH POPS FOR TODAY...HOWEVER LOW CONFIDENCE IN TERMS OF TIMING.
FORECAST IS MOST CLOSELY IN LINE WITH THE HRRR.
FOR THE STORMS CURRENTLY ONGOING...MAIN CONCERN IS GUSTY WINDS. GFS
CAPE FORECAST LOOKS MORE REASONABLE TODAY...RATHER THAN LAST NIGHT
WHERE IT WAS GAPPING THE CWA WITH INSTABILITY. FORECAST CAPE VALUES
ARE AROUND 1500-2000 J/KG FOR THE AFTERNOON. STILL EXPECTING BETWEEN
20 AND 30KTS OF DEEP LAYER SHEAR TODAY AND BETWEEN THIS AND THE
INSTABILITY VALUES...COULD SEE ISOLATED SEVERE STORMS. MAIN THREAT
WILL BE DAMAGING WINDS. ALTHOUGH THE CWA HAS HAD A FEW DAYS WITHOUT
RAIN...ALLOWING US TO BE ABLE TO HANDLE MORE IN TERMS OF
RAINFALL...WILL STILL HAVE TO MONITOR RAINFALL AMOUNTS CLOSELY.
AROUND ONE TO ONE AND A HALF INCHES OF RAIN IS EXPECTED THROUGH
THURSDAY...WITH LOCALIZED HIGHER AMOUNTS POSSIBLE. 1HR FFG VALUES
ARE AROUND 2.5 TO 3.5 INCHES SO WE SHOULD BE ABLE TO HANDLE THESE
AMOUNTS...BUT THERE IS THE POTENTIAL FOR LOCALIZED FLOODING WITH
HIGHER RAINFALL VALUES.
SFC FRONT MOVES THROUGH CWA ON THURSDAY. CONVECTION SHOULD DECREASE
BY THURSDAY MORNING...BUT THEN INCREASE AGAIN ON THURSDAY ALONG AND
SOUTH OF THIS FRONT.
11
LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AT THE BEGINNING OF THE PERIOD A WEAK FRONTAL BOUNDARY WILL BE
MOVING INTO CENTRAL GEORGIA. CONVECTION ASSOCIATED WITH THIS
BOUNDARY MAY BE ONGOING. EXPECT THIS CONVECTION TO BE ON A GENERAL
WEAKENING TREND THROUGH THE EVENING. AT THIS POINT FRIDAY LOOKS TO
BE THE BEST DAY FOR NO POPS ACROSS THE REGION AS WE WAIT FOR
NORTHWEST FLOW TO BRING US ANOTHER IMPULSE AND RAIN TO THE AREA.
MOISTURE ASSOCIATED WITH DORIAN SHOULD HELP IN INCREASE PWATS AND
RAIN CHANCES THIS WEEKEND AND INTO NEXT WEEK. THE MODELS SUGGEST
THAT WE KEEP NORTHWEST FLOW THROUGH AT LEAST MID NEXT WEEK...WHEN
THEY TRY TO BUILD A RIDGE INTO THE SOUTHERN UNITED STATES. MAY
CONCERN IN THE EXTENDED COULD BE RAINFALL ASSOCIATED WITH THE
SHOWERS AND THUNDERSTORMS THIS WEEKEND AND INTO EARLY NEXT WEEK.
THIS WILL NEED TO BE MONITORED CLOSELY FOR POSSIBLE FLOODING AS WE
APPROACH THIS WEEKEND.
ARG
&&
.AVIATION...
12Z UPDATE...
MAIN CONCERN IS TIMING OF SHRA/TSRA THIS MORNING AND LIKELIHOOD OF
TSRA THIS AFTERNOON AND EARLY EVENING. NO SIGN THAT BANDS OF SHRA
WITH EMBEDDED TSRA OVER AL AND NW GA WILL DISSIPATE...HIGH
CONFIDENCE THAT PRECIP WILL CONTINUE THRU MUCH OF THE DAY.
INTENSITY OF TSRA WILL LIKELY BE HELD DOWN BY CLOUDS AND RAIN SO
HAVE KEPT VSBYS UP. WINDS WILL SHIFT TO SSW IN ATL AREA AIRPORTS
AROUND 17Z. WILL LIKELY SEE CIGS APPROACH IFR LATE TONIGHT AFTER
09Z.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF SHRA/TSRA. HIGH CONFIDENCE ON WIND
SHIFT.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 69 88 68 / 70 60 30 20
ATLANTA 84 71 87 70 / 80 60 30 10
BLAIRSVILLE 77 66 83 62 / 90 60 20 10
CARTERSVILLE 85 69 88 66 / 80 60 20 10
COLUMBUS 88 72 91 72 / 70 70 50 30
GAINESVILLE 82 70 86 68 / 70 60 30 10
MACON 87 71 90 70 / 90 50 50 30
ROME 84 70 89 66 / 90 70 20 10
PEACHTREE CITY 84 70 87 66 / 90 50 30 20
VIDALIA 88 73 88 72 / 70 80 60 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....ARG
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
431 AM EDT WED JUL 31 2013
.SHORT TERM /TODAY THROUGH THURSDAY/...
RAIN ALREADY RETURNING TO THE AREA TODAY AS PERTURBATIONS MOVE
THROUGH THE UPPER LEVEL FLOW. MEDIUM RANGE AND HI RES MODELS ARE
IN AGREEMENT THAT THE CWA WILL SEE CONVECTION TODAY...HOWEVER
CONSIDERABLE DISAGREEMENT IN TERMS OF TIMING. WRF NMM SEEMS TO
HAVE A SURGE IN CONVECTION DURING THE MORNING THAN A LULL DURING
THE AFTERNOON. LOCAL WRF TENDS TO WEAKEN CONVECTION THIS
MORNING...DEVELOP ACROSS CENTRAL GEORGIA THIS AFTERNOON AND THEN
ACROSS THE NORTH DURING THE LATE AFTERNOON. HRRR CONTINUES TO
SHIFT THE CURRENT CONVECTION TO THE EAST AND THEN DEVELOP
CONVECTION ACROSS THE ENTIRE CWA AS THE AFTERNOON APPROACHES.
GIVEN ALL OF THIS AND MEDIUM RANGE MODELS...GOOD CONFIDENCE OF
HIGH POPS FOR TODAY...HOWEVER LOW CONFIDENCE IN TERMS OF TIMING.
FORECAST IS MOST CLOSELY IN LINE WITH THE HRRR.
FOR THE STORMS CURRENTLY ONGOING...MAIN CONCERN IS GUSTY WINDS. GFS
CAPE FORECAST LOOKS MORE REASONABLE TODAY...RATHER THAN LAST NIGHT
WHERE IT WAS GAPPING THE CWA WITH INSTABILITY. FORECAST CAPE VALUES
ARE AROUND 1500-2000 J/KG FOR THE AFTERNOON. STILL EXPECTING BETWEEN
20 AND 30KTS OF DEEP LAYER SHEAR TODAY AND BETWEEN THIS AND THE
INSTABILITY VALUES...COULD SEE ISOLATED SEVERE STORMS. MAIN THREAT
WILL BE DAMAGING WINDS. ALTHOUGH THE CWA HAS HAD A FEW DAYS WITHOUT
RAIN...ALLOWING US TO BE ABLE TO HANDLE MORE IN TERMS OF
RAINFALL...WILL STILL HAVE TO MONITOR RAINFALL AMOUNTS CLOSELY.
AROUND ONE TO ONE AND A HALF INCHES OF RAIN IS EXPECTED THROUGH
THURSDAY...WITH LOCALIZED HIGHER AMOUNTS POSSIBLE. 1HR FFG VALUES
ARE AROUND 2.5 TO 3.5 INCHES SO WE SHOULD BE ABLE TO HANDLE THESE
AMOUNTS...BUT THERE IS THE POTENTIAL FOR LOCALIZED FLOODING WITH
HIGHER RAINFALL VALUES.
SFC FRONT MOVES THROUGH CWA ON THURSDAY. CONVECTION SHOULD DECREASE
BY THURSDAY MORNING...BUT THEN INCREASE AGAIN ON THURSDAY ALONG AND
SOUTH OF THIS FRONT.
11
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AT THE BEGINNING OF THE PERIOD A WEAK FRONTAL BOUNDARY WILL BE
MOVING INTO CENTRAL GEORGIA. CONVECTION ASSOCIATED WITH THIS
BOUNDARY MAY BE ONGOING. EXPECT THIS CONVECTION TO BE ON A GENERAL
WEAKENING TREND THROUGH THE EVENING. AT THIS POINT FRIDAY LOOKS TO
BE THE BEST DAY FOR NO POPS ACROSS THE REGION AS WE WAIT FOR
NORTHWEST FLOW TO BRING US ANOTHER IMPULSE AND RAIN TO THE AREA.
MOISTURE ASSOCIATED WITH DORIAN SHOULD HELP IN INCREASE PWATS AND
RAIN CHANCES THIS WEEKEND AND INTO NEXT WEEK. THE MODELS SUGGEST
THAT WE KEEP NORTHWEST FLOW THROUGH AT LEAST MID NEXT WEEK...WHEN
THEY TRY TO BUILD A RIDGE INTO THE SOUTHERN UNITED STATES. MAY
CONCERN IN THE EXTENDED COULD BE RAINFALL ASSOCIATED WITH THE
SHOWERS AND THUNDERSTORMS THIS WEEKEND AND INTO EARLY NEXT WEEK.
THIS WILL NEED TO BE MONITORED CLOSELY FOR POSSIBLE FLOODING AS WE
APPROACH THIS WEEKEND.
ARG
&&
.AVIATION...
06Z UPDATE...
CONVECTIVE ACTIVITY IS A LITTLE EARLIER THAN EXPECTED SO MOVED UP
TIMING OF SHRA IN THE TAFS. ALTHOUGH ISOLD TSRA ARE POSSIBLE THIS
MORNING...BETTER CHANCES STILL REMAIN INTO THE AFTERNOON. STILL
THE POTENTIAL FOR MVFR VSBYS AT AHN AND MCN THIS MORNING BUT
CONFIDENCE IS LOW. WIND SHIFT IS EXPECTED THIS AFTERNOON AT ATL
FROM SE TO SW BUT WIDE RANGE OF TIMING IN THE MODELS AND FORECAST
TIMING IS IN THE MIDDLE OF THE SOLUTIONS.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON VSBYS. LOW CONFIDENCE ON CIGS. LOW CONFIDENCE ON
WIND...DUE TO DIRECTION LATE MORNING INTO THE AFTERNOON. LOW
CONFIDENCE ON TIMING OF SHRA/TSRA.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 84 69 88 68 / 90 70 30 20
ATLANTA 84 71 87 70 / 80 70 30 10
BLAIRSVILLE 77 66 83 62 / 80 60 20 10
CARTERSVILLE 85 69 88 66 / 80 60 20 10
COLUMBUS 88 72 91 72 / 70 60 50 30
GAINESVILLE 82 70 86 68 / 80 70 30 10
MACON 87 71 90 70 / 80 70 50 30
ROME 84 70 89 66 / 80 60 20 10
PEACHTREE CITY 84 70 87 66 / 80 70 30 20
VIDALIA 88 73 88 72 / 60 50 60 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...11
LONG TERM....ARG
AVIATION...11
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1011 PM CDT THU AUG 1 2013
.DISCUSSION...
908 PM CDT
FOR EVENING UPDATE...
NO SIGNIFICANT CHANGES TO GOING FORECAST THIS EVENING...WITH ONLY
SOME MINOR ADJUSTMENTS TO OVERNIGHT POPS/HOURLY TEMPS.
SURFACE HIGH PRESSURE CENTERED DOWNSTATE WAS IN CONTROL OF OUR
WEATHER THIS EVENING...WITH GENERALLY CLEAR SKIES AND LIGHT WINDS
ALLOWING FAIRLY QUICK COOL-OFF IN TEMPS AFTER SUNSET. SERIES OF
DISTURBANCES NOTED IN SATELLITE DATA UPSTREAM ACROSS THE
CENTRAL/NORTHERN PLAINS HOWEVER...WHICH WILL INCREASE THE POTENTIAL
FOR SHOWERS/THUNDERSTORMS LATER TONIGHT AND FRIDAY. FAIRLY DEEP
SHORT WAVE NOTED DIGGING SOUTHEAST THE CANADIAN BORDER INTO NORTH
DAKOTA/MINNESOTA THIS EVENING IS EXPECTED TO BACK AND INCREASE LOW
LEVEL FLOW ACROSS THE MIDWEST OVERNIGHT...WITH WESTERLY LOW LEVEL
JET OF 35-40 KT DEVELOPING ACROSS IA/NORTHERN IL LATE. ALREADY HAVE
SEEN A FEW SCATTERED ELEVATED THUNDERSTORMS DEVELOP OVER PARTS OF
NORTHERN IA...AND WHILE THOSE HAVE WEAKENED AND DECREASED IN
INTENSITY THIS EVENING VARIOUS GUIDANCE WOULD INDICATE ADDITIONAL
DEVELOPMENT IS POSSIBLE WHICH WOULD LIKELY SPREAD EAST INTO NORTHERN
IL IN THE HOURS AFTER MIDNIGHT THROUGH SUNRISE FRIDAY MORNING. 18Z
WRF SOUNDINGS DEPICTED 400-900 J/KG OF ELEVATED CAPE DEVELOPING
PARTICULARLY ACROSS NORTH CENTRAL IL AS MOIST ADVECTION/CONVERGENCE
INCREASES ON THE NOSE OF INCREASING H8 JET AND LARGE SCALE ASCENT
GRADUALLY INCREASES WITH APPROACHING WAVE...WITH SEVERAL RUNS OF
CONVECTION ALLOWING GUIDANCE SUGGESTING ISOLATED TO SCATTERED SHOWER
AND THUNDERSTORM DEVELOPMENT DURING THE PRE-DAWN HOURS. LATEST 00Z
RUN OF HRRR HAS DECREASED COVERAGE A BIT...THOUGH MAINTAINS
CONFIDENCE IN OVERALL SCENARIO. THUS HAVE TWEAKED TIMING OF
ADVANCEMENT OF POPS JUST A BIT OVERNIGHT...AND INCREASED MORE
SOLIDLY INTO CHANCE CATEGORY ESPECIALLY NORTH CENTRAL IL.
OTHERWISE...HAVE ONLY MADE SOME TWEAKS TO HOURLY GRIDS THIS EVENING
FOR EVENING CLOUD AND COOLING TRENDS.
RATZER
//PREV DISCUSSION...
237 PM CDT
LITTLE CHANGE IN OVERALL PATTERN ACROSS MUCH OF NOAM THROUGH THE
WEEKEND AND INTO MID NEXT WEEK. AN UPPER TROUGH TO THE E AND AN
UPPER RIDGE W OF THE REGION MAINTAINS THE NW UPPER FLOW
OVERHEAD... KEEPING TEMPERATURES BELOW NORMALS...WHILE MULTIPLE
SHORT WAVES MOVING THROUGH THIS UPPER FLOW WILL BRING PERIODIC
THREATS OF SHOWERS AND THUNDERSTORMS.
A SURFACE RIDGE OF HIGH PRESSURE WILL CONTINUE TO GRADUALLY MOVE
E OVER AND TO THE E OF THE MS VALLEY THE REST OF TODAY...AND THE
SETTLE SOUTHEASTWARD TO OVER THE TN VALLEY BY 12Z FRI AS A SHORT
WAVE DROPPING S OVER THE CANADIAN PRAIRIE PROVIDENCES AT MIDDAY
REACHES THE NORTH WOODS REGION DURING FRI MORNING. MEANWHILE...A
SHORT WAVE MOVING THROUGH THE TOP OF THE WESTERN UPPER RIDGE
TURNS ESE ARRIVING OVER SW MN AND WESTERN IA BY 12Z FRI.
RETURN FLOW STRENGTHENS OVERNIGHT ON THE BACK SIDE OF THE SURFACE
RIDGE AND AS THE PAIR OF SHORT WAVES APPROACH THE REGION
OVERNIGHT. STRONG WARM AIR ADVECTION AND RESULTING ISENTROPIC
LIFT SPREADS W TO E ACROSS NORTHERN IL DURING THE LATER EVENING
AND OVERNIGHT. LOW LEVEL MOISTURE POOLING ACROSS THE FA AND THE
CONTINUED ESE MOVEMENT OVER THE MN-IA SHORT WAVE MAINTAINS THE
CHANCE OF SHOWERS AND THUNDERSTORMS GOING DURING THE DAY FRI...
AND INTO FRI NIGHT AS A COLD FRONT MOVES SLOWLY SOUTHWARD THROUGH
THE LOCAL FA WITH THE SHORT WAVE TROUGH MOVING OFF TO THE E.
MODELS SHOWING SURFACE DEW POINTS REMAINING IN THE MID AND UPPER
60S ACROSS THE SOUTHERN PORTION OF THE FA DURING SAT AS THE COLD
FRONT ONLY MAKES SLOW SOUTHWARD PROGRESS ACROSS NORTHERN IL. WITH
MODELS SUGGESTING AN ADDITIONAL MINOR DISTURBANCE OR TWO MOVING
THROUGH THE NW FLOW THE CHANCE OF SHOWERS AND THUNDERSTORMS MAY
LINGER INTO THE DAY SAT ACROSS THE FAR SOUTHERN COUNTIES OF THE
FA.
BEHIND THE COLD FRONT ANOTHER AREA OF HIGH PRESSURE MOVES FROM S
CENTRAL CANADA ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST TO
OVER THE UPPER GREAT LAKES...OH VALLEY AND MID MS VALLEY DURING
SAT NIGHT AND SUN RESULTING IN COOL TRANQUIL WEATHER ACROSS THE
REGION UNTIL OVERNIGHT SUN OR MORE LIKELY MON AS A REPEAT
SCENARIO DEVELOPS WITH THE APPROACH OF ANOTHER SHORT WAVE.
ADDITIONAL DISTURBANCES LIKELY TO BE MOVING THROUGH THE NW UPPER
FLOW THOUGH MODELS PRETTY MUCH USELESS AT THIS RANGE AS TIMING
AND/OR LOCATION HIGHLY UNCERTAIN. THUS...WILL CARRY RATHER
GENERIC SLIGHT CHANCE TO LOWER END CHANCE POPS TUE THROUGH THU
THOUGH WOULD EXPECT SIGNIFICANT PERIODS OF NO RAIN DURING THIS
TIME FRAME.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* SHRA AND TSRA POTENTIAL LATE TONIGHT INTO EARLY FRIDAY.
* PSBL VSBY REDUCTION IF SHRA DIRECTLY AFFECT TERMINALS LATE
TONIGHT INTO EARLY FRIDAY.
* SHRA AND TSRA POTENTIAL FRIDAY AFTERNOON AND EVENING.
RC
//DISCUSSION...UPDATED 00Z...
PRIMARY CONCERN IS SHRA AND TSRA POTENTIAL LATE TONIGHT AND
FRIDAY. THE LAKE BREEZE RENEWED SLOW WESTWARD MOVEMENT...BUT IF IT
MAKES IT TO MDW BY OR BEFORE 01Z...WINDS WOULD BE MOST LIKELY TO
TURN LIGHT/VARIABLE. SCATTERED TSRA OVER NE IA WILL PUSH SE AND
LIKELY OUTRUN INSTABILITY AND THUS SUPPORT FOR MAINTENANCE THIS
EVENING...BUT IF THE ACTIVITY HOLDS TOGETHER...03Z IS THE
APPROXIMATE EARLIEST TIMING AT WHICH RFD COULD BE AFFECTED. THERE
IS A MINIMAL CHANCE AT BEST FOR THIS ACTIVITY TO REACH THE EASTERN
TERMINALS.
INCREASING LOW LEVEL JET AND STRONG MID/UPPER JET APPROACHING FROM
THE NW EXPECTED TO RESULT IN SHRA DEVELOPMENT OVER THE AREA LATE
TONIGHT...LIKELY AFTER 06Z. HAVE DECENT CONFIDENCE IN AT LEAST
SCT SHRA SPREADING EASTWARD...BUT LESS CONFIDENCE IN PREVAILING
SHRA AT THE TERMINALS SO HAVE GONE WITH A VCSH MENTION. FORECAST
SOUNDINGS INDICATE THAT TSRA IS POSSIBLE WITH THIS ACTIVITY AND
MORE LIKELY TO OCCUR OUT TOWARD RFD. IF ANY SHRA DIRECTLY AFFECT
TERMINALS...INCREASING MOISTURE CONTENT OF AIRMASS COULD RESULT IN
SUB VFR VSBY. NEXT BEST SUPPORT FOR PRECIP THEN APPEARS TO BE LATE
AFTERNOON WITH APPROACH OF COLD FRONT...BUT CONFIDENCE ON COVERAGE
IS LOW SO MAINTAINED PROB30 TSRA GROUP FROM 21-24Z. SOME CONCERN
THAT UPPER DISTURBANCE SHOWN ON SOME GUIDANCE COULD KEEP CHANCE
FOR TSRA BEYOND 00Z TOMORROW EVE BUT BEST FOCUS SHOULD BE SOUTH OF
TERMINALS AT THAT TIME. FORECAST SOUNDINGS SUGGEST THAT WESTERLY
WINDS COULD GUST TO 20 KT AT TIMES FROM LATE MORNING THROUGH THE
AFTERNOON...WHICH WOULD ESPECIALLY BE THE CASE IF A PERIOD OF
SCATTERING OF CLOUDS AND MIXING OCCURS.
RC
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM CONFIDENCE IN SHRA OVER NE IL LATE TONIGHT INTO EARLY
FRIDAY...LOW-MEDIUM CONFIDENCE IN TIMING...LOW CONFIDENCE IN
DIRECT TERMINAL IMPACTS AND IN TSRA.
* LOW CONFIDENCE IN SUB VFR VSBY LATE TONIGHT INTO EARLY FRIDAY.
* LOW CONFIDENCE IN TSRA FRIDAY AFTERNOON/EARLY EVENING.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY AND SUNDAY...VFR.
MONDAY THROUGH WEDNESDAY...LOW CHANCE FOR TSRA.
RC
&&
.MARINE...
205 PM CDT
HIGH PRESSURE OVER THE CENTRAL PLAINS WILL MOVE EAST INTO THE OHIO
VALLEY TONIGHT ALLOWING FOR A GENTLE SOUTHWEST BREEZE TO DEVELOP
TONIGHT IN ADVANCE OF ANOTHER COLD FRONT SLATED TO MOVE DOWN THE
LAKE FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND
PROVIDE A MODEST INCREASE IN NORTH WINDS OVER THE WEEKEND...BUT NOT
EXPECTING ANYTHING TOO SIGNIFICANT. THE HIGH WILL THEN SETTLE IN
OVER THE LAKES EARLY NEXT WEEK WITH SEVERAL DAYS OF LIGHT WINDS WITH
AFTERNOON LAKE BREEZES.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
909 PM CDT THU AUG 1 2013
.DISCUSSION...
908 PM CDT
FOR EVENING UPDATE...
NO SIGNIFICANT CHANGES TO GOING FORECAST THIS EVENING...WITH ONLY
SOME MINOR ADJUSTMENTS TO OVERNIGHT POPS/HOURLY TEMPS.
SURFACE HIGH PRESSURE CENTERED DOWNSTATE WAS IN CONTROL OF OUR
WEATHER THIS EVENING...WITH GENERALLY CLEAR SKIES AND LIGHT WINDS
ALLOWING FAIRLY QUICK COOL-OFF IN TEMPS AFTER SUNSET. SERIES OF
DISTURBANCES NOTED IN SATELLITE DATA UPSTREAM ACROSS THE
CENTRAL/NORTHERN PLAINS HOWEVER...WHICH WILL INCREASE THE POTENTIAL
FOR SHOWERS/THUNDERSTORMS LATER TONIGHT AND FRIDAY. FAIRLY DEEP
SHORT WAVE NOTED DIGGING SOUTHEAST THE CANADIAN BORDER INTO NORTH
DAKOTA/MINNESOTA THIS EVENING IS EXPECTED TO BACK AND INCREASE LOW
LEVEL FLOW ACROSS THE MIDWEST OVERNIGHT...WITH WESTERLY LOW LEVEL
JET OF 35-40 KT DEVELOPING ACROSS IA/NORTHERN IL LATE. ALREADY HAVE
SEEN A FEW SCATTERED ELEVATED THUNDERSTORMS DEVELOP OVER PARTS OF
NORTHERN IA...AND WHILE THOSE HAVE WEAKENED AND DECREASED IN
INTENSITY THIS EVENING VARIOUS GUIDANCE WOULD INDICATE ADDITIONAL
DEVELOPMENT IS POSSIBLE WHICH WOULD LIKELY SPREAD EAST INTO NORTHERN
IL IN THE HOURS AFTER MIDNIGHT THROUGH SUNRISE FRIDAY MORNING. 18Z
WRF SOUNDINGS DEPICTED 400-900 J/KG OF ELEVATED CAPE DEVELOPING
PARTICULARLY ACROSS NORTH CENTRAL IL AS MOIST ADVECTION/CONVERGENCE
INCREASES ON THE NOSE OF INCREASING H8 JET AND LARGE SCALE ASCENT
GRADUALLY INCREASES WITH APPROACHING WAVE...WITH SEVERAL RUNS OF
CONVECTION ALLOWING GUIDANCE SUGGESTING ISOLATED TO SCATTERED SHOWER
AND THUNDERSTORM DEVELOPMENT DURING THE PRE-DAWN HOURS. LATEST 00Z
RUN OF HRRR HAS DECREASED COVERAGE A BIT...THOUGH MAINTAINS
CONFIDENCE IN OVERALL SCENARIO. THUS HAVE TWEAKED TIMING OF
ADVANCEMENT OF POPS JUST A BIT OVERNIGHT...AND INCREASED MORE
SOLIDLY INTO CHANCE CATEGORY ESPECIALLY NORTH CENTRAL IL.
OTHERWISE...HAVE ONLY MADE SOME TWEAKS TO HOURLY GRIDS THIS EVENING
FOR EVENING CLOUD AND COOLING TRENDS.
RATZER
&&
.PREV DISCUSSION...
237 PM CDT
LITTLE CHANGE IN OVERALL PATTERN ACROSS MUCH OF NOAM THROUGH THE
WEEKEND AND INTO MID NEXT WEEK. AN UPPER TROUGH TO THE E AND AN
UPPER RIDGE W OF THE REGION MAINTAINS THE NW UPPER FLOW
OVERHEAD... KEEPING TEMPERATURES BELOW NORMALS...WHILE MULTIPLE
SHORT WAVES MOVING THROUGH THIS UPPER FLOW WILL BRING PERIODIC
THREATS OF SHOWERS AND THUNDERSTORMS.
A SURFACE RIDGE OF HIGH PRESSURE WILL CONTINUE TO GRADUALLY MOVE
E OVER AND TO THE E OF THE MS VALLEY THE REST OF TODAY...AND THE
SETTLE SOUTHEASTWARD TO OVER THE TN VALLEY BY 12Z FRI AS A SHORT
WAVE DROPPING S OVER THE CANADIAN PRAIRIE PROVIDENCES AT MIDDAY
REACHES THE NORTH WOODS REGION DURING FRI MORNING. MEANWHILE...A
SHORT WAVE MOVING THROUGH THE TOP OF THE WESTERN UPPER RIDGE
TURNS ESE ARRIVING OVER SW MN AND WESTERN IA BY 12Z FRI.
RETURN FLOW STRENGTHENS OVERNIGHT ON THE BACK SIDE OF THE SURFACE
RIDGE AND AS THE PAIR OF SHORT WAVES APPROACH THE REGION
OVERNIGHT. STRONG WARM AIR ADVECTION AND RESULTING ISENTROPIC
LIFT SPREADS W TO E ACROSS NORTHERN IL DURING THE LATER EVENING
AND OVERNIGHT. LOW LEVEL MOISTURE POOLING ACROSS THE FA AND THE
CONTINUED ESE MOVEMENT OVER THE MN-IA SHORT WAVE MAINTAINS THE
CHANCE OF SHOWERS AND THUNDERSTORMS GOING DURING THE DAY FRI...
AND INTO FRI NIGHT AS A COLD FRONT MOVES SLOWLY SOUTHWARD THROUGH
THE LOCAL FA WITH THE SHORT WAVE TROUGH MOVING OFF TO THE E.
MODELS SHOWING SURFACE DEW POINTS REMAINING IN THE MID AND UPPER
60S ACROSS THE SOUTHERN PORTION OF THE FA DURING SAT AS THE COLD
FRONT ONLY MAKES SLOW SOUTHWARD PROGRESS ACROSS NORTHERN IL. WITH
MODELS SUGGESTING AN ADDITIONAL MINOR DISTURBANCE OR TWO MOVING
THROUGH THE NW FLOW THE CHANCE OF SHOWERS AND THUNDERSTORMS MAY
LINGER INTO THE DAY SAT ACROSS THE FAR SOUTHERN COUNTIES OF THE
FA.
BEHIND THE COLD FRONT ANOTHER AREA OF HIGH PRESSURE MOVES FROM S
CENTRAL CANADA ACROSS THE NORTHERN PLAINS AND UPPER MIDWEST TO
OVER THE UPPER GREAT LAKES...OH VALLEY AND MID MS VALLEY DURING
SAT NIGHT AND SUN RESULTING IN COOL TRANQUIL WEATHER ACROSS THE
REGION UNTIL OVERNIGHT SUN OR MORE LIKELY MON AS A REPEAT
SCENARIO DEVELOPS WITH THE APPROACH OF ANOTHER SHORT WAVE.
ADDITIONAL DISTURBANCES LIKELY TO BE MOVING THROUGH THE NW UPPER
FLOW THOUGH MODELS PRETTY MUCH USELESS AT THIS RANGE AS TIMING
AND/OR LOCATION HIGHLY UNCERTAIN. THUS...WILL CARRY RATHER
GENERIC SLIGHT CHANCE TO LOWER END CHANCE POPS TUE THROUGH THU
THOUGH WOULD EXPECT SIGNIFICANT PERIODS OF NO RAIN DURING THIS
TIME FRAME.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SHRA AND TSRA POTENTIAL LATE TONIGHT INTO EARLY FRIDAY.
* PSBL VSBY REDUCTION IF SHRA DIRECTLY AFFECT TERMINALS LATE
TONIGHT INTO EARLY FRIDAY.
* SHRA AND TSRA POTENTIAL FRIDAY AFTERNOON AND EVENING.
RC
//DISCUSSION...UPDATED 00Z...
PRIMARY CONCERN IS SHRA AND TSRA POTENTIAL LATE TONIGHT AND
FRIDAY. THE LAKE BREEZE RENEWED SLOW WESTWARD MOVEMENT...BUT IF IT
MAKES IT TO MDW BY OR BEFORE 01Z...WINDS WOULD BE MOST LIKELY TO
TURN LIGHT/VARIABLE. SCATTERED TSRA OVER NE IA WILL PUSH SE AND
LIKELY OUTRUN INSTABILITY AND THUS SUPPORT FOR MAINTENANCE THIS
EVENING...BUT IF THE ACTIVITY HOLDS TOGETHER...03Z IS THE
APPROXIMATE EARLIEST TIMING AT WHICH RFD COULD BE AFFECTED. THERE
IS A MINIMAL CHANCE AT BEST FOR THIS ACTIVITY TO REACH THE EASTERN
TERMINALS.
INCREASING LOW LEVEL JET AND STRONG MID/UPPER JET APPROACHING FROM
THE NW EXPECTED TO RESULT IN SHRA DEVELOPMENT OVER THE AREA LATE
TONIGHT...LIKELY AFTER 06Z. HAVE DECENT CONFIDENCE IN AT LEAST
SCT SHRA SPREADING EASTWARD...BUT LESS CONFIDENCE IN PREVAILING
SHRA AT THE TERMINALS SO HAVE GONE WITH A VCSH MENTION. FORECAST
SOUNDINGS INDICATE THAT TSRA IS POSSIBLE WITH THIS ACTIVITY AND
MORE LIKELY TO OCCUR OUT TOWARD RFD. IF ANY SHRA DIRECTLY AFFECT
TERMINALS...INCREASING MOISTURE CONTENT OF AIRMASS COULD RESULT IN
SUB VFR VSBY. NEXT BEST SUPPORT FOR PRECIP THEN APPEARS TO BE LATE
AFTERNOON WITH APPROACH OF COLD FRONT...BUT CONFIDENCE ON COVERAGE
IS LOW SO MAINTAINED PROB30 TSRA GROUP FROM 21-24Z. SOME CONCERN
THAT UPPER DISTURBANCE SHOWN ON SOME GUIDANCE COULD KEEP CHANCE
FOR TSRA BEYOND 00Z TOMORROW EVE BUT BEST FOCUS SHOULD BE SOUTH OF
TERMINALS AT THAT TIME. FORECAST SOUNDINGS SUGGEST THAT WESTERLY
WINDS COULD GUST TO 20 KT AT TIMES FROM LATE MORNING THROUGH THE
AFTERNOON...WHICH WOULD ESPECIALLY BE THE CASE IF A PERIOD OF
SCATTERING OF CLOUDS AND MIXING OCCURS.
RC
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM CONFIDENCE IN SHRA OVER NE IL LATE TONIGHT INTO EARLY
FRIDAY...LOW CONFIDENCE IN DIRECT TERMINAL IMPACTS AND IN TSRA.
* LOW CONFIDENCE IN SUB VFR VSBY LATE TONIGHT INTO EARLY FRIDAY.
* LOW CONFIDENCE IN TSRA FRIDAY AFTERNOON/EARLY EVENING.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY AND SUNDAY...VFR.
MONDAY THROUGH WEDNESDAY...LOW CHANCE FOR TSRA.
RC
&&
.MARINE...
205 PM CDT
HIGH PRESSURE OVER THE CENTRAL PLAINS WILL MOVE EAST INTO THE OHIO
VALLEY TONIGHT ALLOWING FOR A GENTLE SOUTHWEST BREEZE TO DEVELOP
TONIGHT IN ADVANCE OF ANOTHER COLD FRONT SLATED TO MOVE DOWN THE
LAKE FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND
PROVIDE A MODEST INCREASE IN NORTH WINDS OVER THE WEEKEND...BUT NOT
EXPECTING ANYTHING TOO SIGNIFICANT. THE HIGH WILL THEN SETTLE IN
OVER THE LAKES EARLY NEXT WEEK WITH SEVERAL DAYS OF LIGHT WINDS WITH
AFTERNOON LAKE BREEZES.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
948 PM CDT THU AUG 1 2013
.UPDATE...
ISSUED AT 947 PM CDT THU AUG 1 2013
AREA RADARS CONTINUE TO SHOW SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER NE IA...INTO SW WI AND NW IL...MOVING SOUTHEAST
AND GENERALLY IN DISSIPATION MODE. A LARGE COMPLEX OF
THUNDERSTORMS IS CONCENTRATED OVER THE STATE OF NEB TONIGHT WHERE
00Z UPPER AIR ANALYSIS SHOWED FEED OF 14 PLUS C DEWPOINTS AT 850
MB INTERACTING WITH A SHORTWAVE IN THE NW FLOW ALOFT. THIS MCS IS
MOVING SOUTHEAST DOWN THE BACK SIDE OF THE UPPER RIDGE TOWARD KS
AND NW MO. LATEST HIGH RES MODELS CONTINUE TO SUGGEST THE
CONVECTION TO OUR N WILL HOLD TOGETHER AND MOVE THROUGH THE
FORECAST AREA OVERNIGHT...WHICH BASED ON THE PAST FEW
RUNS...APPEARS OVERLY AGGRESSIVE. WILL MORE LIKELY SEE THESE
SHOWERS AND THUNDERSTORMS MOVE INTO FAR EAST CENTRAL IA AND NW IL
AND CONTINUE DISSIPATE OVER THE NEXT COUPLE HOURS AS THE MUCAPE
VALUES CONTINUE TO WANE. BASED ON 00Z ANALYSIS AND A LOOK AT THE
NEW 00Z WRF...THERE APPEARS TO BE LITTLE SUPPORT FOR ADDITIONAL
THUNDERSTORMS OVER THE NEXT FEW HOURS...UNTIL THE SUPPORT OVER NEB
AND WEAK 850 MOISTURE CONVERGENCE REFOCUSES ON S CENTRAL IA AND
THEN SE IA TOWARD MORNING. NEITHER THIS MODEL...OR THE BULK OF
THE OPERATIONAL MODELS FROM THE PREVIOUS RUN HAD A GOOD HANDLE ON
THE PLACEMENT OF CONVECTION IN THE PLAINS THIS EVENING.
HAVE THUS MADE SIGNIFICANT REVISIONS TO THE FORECAST TO LOWER POPS
OVER ESPECIALLY THE NORTH FOR OVERNIGHT INTO FRIDAY MORNING.
&&
.SYNOPSIS...
ISSUED AT 326 PM CDT THU AUG 1 2013
12Z UA ANALYSIS HAS A WEAK 850MB COLD FRONT FROM LAKE HURON TO THE
MN/IA BORDER. A RESPECTABLE SHORTWAVE RAN FROM THE DAKOTAS INTO
WESTERN NEBRASKA WHILE A MOISTURE GRADIENT RAN FROM WESTERN MISSOURI
INTO NEBRASKA. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOW
CONVECTION ASSOCIATED WITH THE DAKOTAS SHORT WAVE AND NEW CONVECTION
ON THE NORTH EDGE OF THE MOISTURE GRADIENT ACROSS NEBRASKA.
18Z SFC ANALYSIS HAS WEAK LOWS IN COLORADO AND SOUTHEAST WYOMING AND
ANOTHER IN WESTERN MINNESOTA. WEAK BOUNDARIES CONNECTED THE
MINNESOTA LOW TO THE LOW IN WYOMING WHILE SEVERAL WEAK TROFS WERE
ACROSS THE GREAT LAKES. A SFC MOISTURE BOUNDARY RAN FROM NEBRASKA
INTO NORTHWEST MISSOURI. DEW POINTS WERE IN THE 50S ACROSS THE GREAT
LAKES AND UPPER MIDWEST WITH 60S ACROSS MUCH OF THE PLAINS AND OHIO
VALLEY. DEW POINTS IN THE 70S WERE ACROSS THE SOUTHERN PLAINS AND
DEEP SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 326 PM CDT THU AUG 1 2013
DEEP MIXING THIS AFTERNOON HAS DROPPED THE DEW POINTS INTO THE LOW
TO MID 50S ACROSS WISCONSIN...NORTHERN ILLINOIS...AND NORTHEAST
IOWA. THE DEEP MIXING COMBINED WITH SUBSIDENCE HAS PREVENTED ANY
DIURNAL CLOUD DEVELOPMENT.
BASED ON SATELLITE AND RAP TRENDS USING THE MCS/LIFT TOOLS...THE
AGITATED CU DEVELOPMENT ALONG THE MN/IA BORDER SHOULD SLOWLY EVOLVE
INTO ISOLATED TO SCATTERED SHOWERS AND POSSIBLY A COUPLE OF
THUNDERSTORMS ACROSS THE NORTHERN CWFA DURING THE EVENING HOURS. THE
MORE SUBSTANTIAL STORM DEVELOPMENT ACROSS NEBRASKA MAY INDUCE SOME
ISOLATED SHOWERS OR A THUNDERSTORM ACROSS THE SOUTHERN HALF OF THE
CWFA BY MID TO LATE EVENING. STARTING AROUND MIDNIGHT THERE MAY BE A
LULL IN ACTIVITY FOR SEVERAL HOURS.
THE MCS TOOL IS REASONABLY CONSISTENT INDICATING A RESPECTABLE MCS
WILL DEVELOP THIS EVENING ACROSS EASTERN NEBRASKA/WESTERN IOWA AND
MOVE EAST SOUTHEAST OVERNIGHT ARRIVING IN THE SOUTHERN TWO THIRDS OF
THE CWFA PRIOR TO SUNRISE. CORFIDI VECTORS DO NOT SUGGEST ANY BACK
BUILDING BUT THE BACKWARD PROPAGATING VECTORS DO BECOME
PERPENDICULAR ACROSS THE SOUTHERN HALF OF THE CWFA SUGGESTING A WEAK
THREAT OF STORMS MOVING OVER THE SAME AREA.
THE DRIER AIR ACROSS THE AREA MAY RESULT IN SOME SMALL HAIL IN THE
STRONGER STORMS BEFORE THE ATMOSPHERE SATURATES LATE TONIGHT.
ON FRIDAY THE NOCTURNAL MCS WILL BE OVER THE CWFA DURING THE MORNING
HOURS AND WILL SLOWLY DECAY INTO MORE SHOWERS THAN THUNDERSTORMS BY
LATE MORNING. BOUNDARIES LEFT OVER FROM THIS MCS WILL THEN PROVIDE
THE FOCUS FOR NEW DEVELOPMENT DURING THE AFTERNOON. THE MCS TOOL
WHEN APPLIED TO SOME MODELS SUGGESTS THE POTENTIAL FOR ANOTHER MCS
AFFECTING THE AREA LATE FRIDAY AFTERNOON AND INTO FRIDAY NIGHT.
TEMPERATURES ON FRIDAY MAY REMAIN IN THE 60S FOR THE MORNING UNTIL
THE RAIN ENDS AND THEN CLIMBING INTO THE 70S DURING THE
AFTERNOON. ..08..
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 326 PM CDT THU AUG 1 2013
FORECAST FOCUS IS ON PERIODS FOR PRECIPITATION CHANCES AND BELOW
NORMAL TEMPERATURES THROUGH NEXT WEEK.
FRIDAY NIGHT AND SATURDAY...CHANCES FOR SHOWERS AND A FEW
THUNDERSTORMS CONTINUE FRIDAY EVENING AS UPPER SHORTWAVE ENERGY
WORKS ITS WAY ACROSS THE AREA. THE BETTER CHANCES LOOK TO BE ACROSS
THE SOUTHERN FORECAST SECTIONS...AND WILL DIMINISH SATURDAY MORNING
AS THE SHORTWAVE DEPARTS.
SUNDAY THROUGH THURSDAY...SEVERAL SHORTWAVES ARE FORECAST TO MOVE
THROUGH THE CONTINUED NORTHWEST FLOW AND BRING A COUPLE
OPPORTUNITIES FOR SHOWERS AND STORMS. AS CAN BE EXPECTED...FORECAST
MODELS ARE SHOWING QUITE A BIT OF VARIATION IN TIMING AND PLACEMENT
OF THESE SMALLER SCALE FEATURES. THEREFORE CONFIDENCE IN WHICH DAYS
HOLD THE BEST CHANCE FOR PRECIPITATION IS LOW. SEASONABLY COOL
TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MIDDLE 70S TO LOWER 80S
RANGE...AND LOWS IN THE MIDDLE 50S TO LOWER 60S FOR MOST OF THE WEEK.
STOFLET
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 646 PM CDT THU AUG 1 2013
A CLUSTER OF THUNDERSTORMS ALONG AN ELEVATED BOUNDARY WILL MOVE
INTO EASTERN IA...LIKELY AFFECTING THE EASTERN IA TERMINALS THIS
EVENING. BEYOND...A LARGER COMPLEX OF RAIN AND THUNDERSTORMS MAY
DEVELOP OVER THE AREA LATE TONIGHT AND AFFECT THE AREA INTO FRIDAY
MORNING. CONFIDENCE IN THE TIMING AND COVERAGE REMAINS LOW AND
HAVE FOR NOW HAVE GONE WITH A BROAD BRUSHED RAIN FORECAST WITH
MVFR CONDITIONS THROUGH FRIDAY MORNING. IN THE AFTERNOON...
CONDITIONS WILL BECOME FAVORABLE FOR EMBEDDED THUNDERSTORMS AND
HAVE INCLUDED THIS AS PROB30 GROUPS FOR MID TO LATE AFTERNOON.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...08
SHORT TERM...08
LONG TERM...STOFLET
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
646 PM CDT THU AUG 1 2013
.UPDATE...
ISSUED AT 646 PM CDT THU AUG 1 2013
CLUSTER OF STRONG TO SEVERE STORMS OVER NORTH CENTRAL IA...THAT
PRODUCED A FEW REPORTS OF QUARTER SIZE HAIL AND AT LEAST ONE
INSTANCE OF DAMAGING WIND BETWEEN 4 AND 5 PM WERE MIGRATING EAST
TO SOUTHEAST AROUND 30 MPH INTO A MORE STABLE AIRMASS. THESE
APPEARED TO BE ROOTED ALONG AN ELEVATED AXIS OF THETAE
CONVERGENCE...WHICH WILL CONTINUE EAST-SE THIS EVENING.
HOWEVER...THE EASTERN GRADIENT OF AN AXIS OF HIGHEST MUCAPE AND
MORE FAVORABLE SHEAR REMAINS ORIENTED NNW TO SSE JUST ALONG THE
WESTERN EDGE OF OUR EASTERN IOWA FORECAST AREA BORDER. WHILE SOME
EASTWARD SHIFT IN THESE PARAMETERS IS LIKELY THIS EVENING AS THE
SURFACE RIDGE RETREATS EASTWARD...THE POTENTIAL FOR SEVERE HAIL
LOOKS LIMITED. CURRENT TRENDS SUGGEST THE STRONGEST PULSING
STORMS...THAT PRESENT A MORE S-SE MOVEMENT MAY PRODUCE UP TO PENNY
SIZE HAIL NW OF A CID TO DBQ AXIS THIS EVENING ALONG WITH BRIEF
HEAVY RAINFALL. WILL BE ADJUSTING POPS UPWARDS FOR THIS AREA
SHORTLY.
&&
.SYNOPSIS...
ISSUED AT 326 PM CDT THU AUG 1 2013
12Z UA ANALYSIS HAS A WEAK 850MB COLD FRONT FROM LAKE HURON TO THE
MN/IA BORDER. A RESPECTABLE SHORTWAVE RAN FROM THE DAKOTAS INTO
WESTERN NEBRASKA WHILE A MOISTURE GRADIENT RAN FROM WESTERN MISSOURI
INTO NEBRASKA. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOW
CONVECTION ASSOCIATED WITH THE DAKOTAS SHORT WAVE AND NEW CONVECTION
ON THE NORTH EDGE OF THE MOISTURE GRADIENT ACROSS NEBRASKA.
18Z SFC ANALYSIS HAS WEAK LOWS IN COLORADO AND SOUTHEAST WYOMING AND
ANOTHER IN WESTERN MINNESOTA. WEAK BOUNDARIES CONNECTED THE
MINNESOTA LOW TO THE LOW IN WYOMING WHILE SEVERAL WEAK TROFS WERE
ACROSS THE GREAT LAKES. A SFC MOISTURE BOUNDARY RAN FROM NEBRASKA
INTO NORTHWEST MISSOURI. DEW POINTS WERE IN THE 50S ACROSS THE GREAT
LAKES AND UPPER MIDWEST WITH 60S ACROSS MUCH OF THE PLAINS AND OHIO
VALLEY. DEW POINTS IN THE 70S WERE ACROSS THE SOUTHERN PLAINS AND
DEEP SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 326 PM CDT THU AUG 1 2013
DEEP MIXING THIS AFTERNOON HAS DROPPED THE DEW POINTS INTO THE LOW
TO MID 50S ACROSS WISCONSIN...NORTHERN ILLINOIS...AND NORTHEAST
IOWA. THE DEEP MIXING COMBINED WITH SUBSIDENCE HAS PREVENTED ANY
DIURNAL CLOUD DEVELOPMENT.
BASED ON SATELLITE AND RAP TRENDS USING THE MCS/LIFT TOOLS...THE
AGITATED CU DEVELOPMENT ALONG THE MN/IA BORDER SHOULD SLOWLY EVOLVE
INTO ISOLATED TO SCATTERED SHOWERS AND POSSIBLY A COUPLE OF
THUNDERSTORMS ACROSS THE NORTHERN CWFA DURING THE EVENING HOURS. THE
MORE SUBSTANTIAL STORM DEVELOPMENT ACROSS NEBRASKA MAY INDUCE SOME
ISOLATED SHOWERS OR A THUNDERSTORM ACROSS THE SOUTHERN HALF OF THE
CWFA BY MID TO LATE EVENING. STARTING AROUND MIDNIGHT THERE MAY BE A
LULL IN ACTIVITY FOR SEVERAL HOURS.
THE MCS TOOL IS REASONABLY CONSISTENT INDICATING A RESPECTABLE MCS
WILL DEVELOP THIS EVENING ACROSS EASTERN NEBRASKA/WESTERN IOWA AND
MOVE EAST SOUTHEAST OVERNIGHT ARRIVING IN THE SOUTHERN TWO THIRDS OF
THE CWFA PRIOR TO SUNRISE. CORFIDI VECTORS DO NOT SUGGEST ANY BACK
BUILDING BUT THE BACKWARD PROPAGATING VECTORS DO BECOME
PERPENDICULAR ACROSS THE SOUTHERN HALF OF THE CWFA SUGGESTING A WEAK
THREAT OF STORMS MOVING OVER THE SAME AREA.
THE DRIER AIR ACROSS THE AREA MAY RESULT IN SOME SMALL HAIL IN THE
STRONGER STORMS BEFORE THE ATMOSPHERE SATURATES LATE TONIGHT.
ON FRIDAY THE NOCTURNAL MCS WILL BE OVER THE CWFA DURING THE MORNING
HOURS AND WILL SLOWLY DECAY INTO MORE SHOWERS THAN THUNDERSTORMS BY
LATE MORNING. BOUNDARIES LEFT OVER FROM THIS MCS WILL THEN PROVIDE
THE FOCUS FOR NEW DEVELOPMENT DURING THE AFTERNOON. THE MCS TOOL
WHEN APPLIED TO SOME MODELS SUGGESTS THE POTENTIAL FOR ANOTHER MCS
AFFECTING THE AREA LATE FRIDAY AFTERNOON AND INTO FRIDAY NIGHT.
TEMPERATURES ON FRIDAY MAY REMAIN IN THE 60S FOR THE MORNING UNTIL
THE RAIN ENDS AND THEN CLIMBING INTO THE 70S DURING THE
AFTERNOON. ..08..
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 326 PM CDT THU AUG 1 2013
FORECAST FOCUS IS ON PERIODS FOR PRECIPITATION CHANCES AND BELOW
NORMAL TEMPERATURES THROUGH NEXT WEEK.
FRIDAY NIGHT AND SATURDAY...CHANCES FOR SHOWERS AND A FEW
THUNDERSTORMS CONTINUE FRIDAY EVENING AS UPPER SHORTWAVE ENERGY
WORKS ITS WAY ACROSS THE AREA. THE BETTER CHANCES LOOK TO BE ACROSS
THE SOUTHERN FORECAST SECTIONS...AND WILL DIMINISH SATURDAY MORNING
AS THE SHORTWAVE DEPARTS.
SUNDAY THROUGH THURSDAY...SEVERAL SHORTWAVES ARE FORECAST TO MOVE
THROUGH THE CONTINUED NORTHWEST FLOW AND BRING A COUPLE
OPPORTUNITIES FOR SHOWERS AND STORMS. AS CAN BE EXPECTED...FORECAST
MODELS ARE SHOWING QUITE A BIT OF VARIATION IN TIMING AND PLACEMENT
OF THESE SMALLER SCALE FEATURES. THEREFORE CONFIDENCE IN WHICH DAYS
HOLD THE BEST CHANCE FOR PRECIPITATION IS LOW. SEASONABLY COOL
TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MIDDLE 70S TO LOWER 80S
RANGE...AND LOWS IN THE MIDDLE 50S TO LOWER 60S FOR MOST OF THE WEEK.
STOFLET
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 646 PM CDT THU AUG 1 2013
A CLUSTER OF THUNDERSTORMS ALONG AN ELEVATED BOUNDARY WILL MOVE
INTO EASTERN IA...LIKELY AFFECTING THE EASTERN IA TERMINALS THIS
EVENING. BEYOND...A LARGER COMPLEX OF RAIN AND THUNDERSTORMS MAY
DEVELOP OVER THE AREA LATE TONIGHT AND AFFECT THE AREA INTO FRIDAY
MORNING. CONFIDENCE IN THE TIMING AND COVERAGE REMAINS LOW AND
HAVE FOR NOW HAVE GONE WITH A BROAD BRUSHED RAIN FORECAST WITH
MVFR CONDITIONS THROUGH FRIDAY MORNING. IN THE AFTERNOON...
CONDITIONS WILL BECOME FAVORABLE FOR EMBEDDED THUNDERSTORMS AND
HAVE INCLUDED THIS AS PROB30 GROUPS FOR MID TO LATE AFTERNOON.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...08
SHORT TERM...08
LONG TERM...STOFLET
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1244 PM CDT WED JUL 31 2013
.UPDATE...
ISSUED AT 1234 PM CDT WED JUL 31 2013
THE CLEARING TREND IS SLOW BUT CONTINUES. WHERE THE CLOUDS HAVE
CLEARED DIURNAL CU HAS DEVELOPED. BASED ON OVERALL TEMPERATURE
TRENDS THE MAX TEMPERATURES HAVE BEEN LOWERED BY A DEGREE.
THE POSSIBILITY OF DIURNAL CONVECTION IS BECOMING DOUBTFUL. THE
RAP TRENDS CONTINUE TO SHOW BOTH THE THERMAL AND CONVECTIVE
TEMPERATURES RISING TO OR ABOVE THE MAX TEMPERATURES FOR THIS
AFTERNOON. THE CU THAT HAS DEVELOPED HAS SHOWN NO UPSCALE GROWTH
SUGGESTING CONVECTION IS NOT IMMINENT.
POPS FOR THIS AFTERNOON HAVE BEEN CUT BACK A BIT FURTHER BUT MAY
STILL BE TOO HIGH IN AREAL COVERAGE AND AMOUNTS. IF CONVECTION
DOES OCCUR...IT WOULD BE DURING PEAK HEATING AND THEN MAY ONLY BE
ISOLATED SHOWERS. ..08..
UPDATE ISSUED AT 959 AM CDT WED JUL 31 2013
SATELLITE TRENDS THIS MORNING SHOW THE CLOUDS ARE
THINNING/CLEARING. THIS THINNING/CLEARING WILL CONTINUE DURING THE
LATE MORNING AND EARLY AFTERNOON HOURS.
THERE ARE QUESTIONS REGARDING THE POTENTIAL FOR DIURNAL CONVECTION
THIS AFTERNOON. THERE IS NO REAL COHERENT BOUNDARY AND THE FORCING
IS QUITE WEAK. IMMEDIATE TRENDS FROM THE RAP SHOW DOWNWARD MOTION
CONTINUING INTO LATE MORNING BEFORE SOME LIFT DEVELOPS AHEAD OF
THE NEXT SHORTWAVE IN THE AFTERNOON. FCST SOUNDINGS SHOW
CONVECTIVE TEMPERATURES CLIMBING INTO THE UPPER 70S WHICH IS RIGHT
AROUND THE MAX TEMPERATURES FOR THE DAY.
SO...WILL CONTINUE THE POSSIBILITY OF ISOLATED
SHOWERS/THUNDERSTORMS ACROSS MAINLY THE NORTHERN CWFA DURING THE
AFTERNOON FOR NOW. THE POSSIBILITY DOES EXIST THAT THE PRECIP
POTENTIAL MAY GET PULLED DEPENDING UPON HOW THINGS EVOLVE DURING
THE AFTERNOON. ..08..
&&
.SYNOPSIS...
ISSUED AT 305 AM CDT WED JUL 31 2013
ANALYSIS AT 07Z (2 AM CDT) DEPICTS AREA UNDER LOW CLOUDS AND FOG AS
REMNANTS OF UPPER DISTURBANCE FROM YESTERDAY MOVES EAST. SURFACE
ANALYSIS PRESSURE RISE AND FALL PATTERN SUPPORTS UPPER AIR AND MOST
SOLUTIONS OF SLIGHTLY DRIER AIR AND SUBSIDENCE TO ARRIVE NEXT
SEVERAL HOURS FROM THE NORTHWEST. NW FLOW TO CONTINUE OVER AREA
NEXT SEVERAL DAYS KEEPING REGION NEAR TO SLIGHTLY BELOW NORMAL
REGARDING TEMPERATURES AS HAS BEEN THE CASE NOW FOR MUCH OF THIS
SUMMER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CDT WED JUL 31 2013
TODAY...ANALYSIS SUPPORTS LOW CLOUDS AND AREAS OF FOG WITH
VISIBILITIES OF 1-3 MILES TO BURN OFF BETWEEN 8-10 AM. SUBSIDENCE
WITH DIFFLUENT LOW LEVEL FLOW AND MIXING SUGGESTS CONVECTIVE
TEMPERATURES UNLIKELY TO BE REACHED AND THUS DRY CONDITIONS
WARRANTED. A WEAK UPPER DISTURBANCE IN SOUTH DAKOTA WILL NEED TO
BE MONITORED BY DAY SHIFT BUT NOWCAST TOOLS SUGGEST IT WILL BE
DRY. LOW LEVEL THERMAL FIELDS AND MODEST BL MIXING INDICATE HIGHS
WITHIN A DEGREE OR TWO OF 80 DEGREES FOR TODAY...A WARM MID SUMMER
DAY WITH DEWPOINTS IN THE LOWER TO MIDDLE 60S FOR MODERATE HUMIDITY.
THESE TEMPERATURES ARE GENERALLY 3 TO 5 DEGREES BELOW NORMAL.
TONIGHT...LIGHT NORTHWEST WINDS SHOULD BRING IN ENOUGH DRIER AIR
AND ENOUGH MIXING TO LIMIT ANY FOG FORMATION TONIGHT. MOSTLY FAIR
SKIES WILL ALLOW FOR MINS IN THE UPPER 50S FAR NW SECTIONS TO THE
LOWER 60S ELSEWHERE. AGAIN THIS IS A FEW DEGREES BELOW NORMAL.
NICHOLS
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 305 AM CDT WED JUL 31 2013
NORTHWEST FLOW WILL KEEP TEMPERATURES BELOW NORMAL THROUGH THE
EXTENDED PERIOD WITH HIGHS GENERALLY IN THE UPPER 70S TO LOWER 80S
AND LOWS IN THE LOWER TO MID 60S.
THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME MAINLY ON
FRIDAY AND THEN AGAIN SUNDAY NIGHT INTO MONDAY AS SIGNIFICANT WAVES
MOVE ALONG IN THE FLOW.
INTERESTING THAT THE 00Z ECMWF HAS BACKED OFF ON SHOWING A POLAR VORTEX
DIVING INTO NORTHERN MN ON AUGUST 8. IT NOW DEPICTS MORE OF A BROAD
TROF IN THE EASTERN UNITED STATES WITH A 1030 MB HIGH DROPPING INTO
THE UPPER MIDWEST WITH 850 MB TEMPERATURES OF +8C INTO THE DVN CWA.
WE SHALL SEE WHAT THE NEXT RUNS SHOW.
HAASE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1234 PM CDT WED JUL 31 2013
CIGS CONTINUE TO RAISE ACROSS THE AREA WITH MVFR CIGS GENERALLY
ALONG AND EAST OF THE MISSISSIPPI. VFR WX WILL DEVELOP THROUGH
00Z/01 ACROSS THE AREA WITH A VERY WEAK FRONT PASSING THROUGH.
DIURNAL CONVECTION MAY OCCUR THIS AFTERNOON BUT OVERALL COVERAGE
SHOULD BE 15 PERCENT OR LESS. THE PROBABILITY OF A SHRA OR TSRA
AFFECTING A TAF SITE THROUGH 00Z/01 IS AT BEST 5 PERCENT. AFT
00Z/01 VFR WX IS EXPECTED WITH POSSIBLY SOME VERY LOCALIZED GROUND
FOG AROUND SUNRISE. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1009 AM CDT WED JUL 31 2013
.UPDATE...
ISSUED AT 959 AM CDT WED JUL 31 2013
SATELLITE TRENDS THIS MORNING SHOW THE CLOUDS ARE
THINNING/CLEARING. THIS THINNING/CLEARING WILL CONTINUE DURING THE
LATE MORNING AND EARLY AFTERNOON HOURS.
THERE ARE QUESTIONS REGARDING THE POTENTIAL FOR DIURNAL CONVECTION
THIS AFTERNOON. THERE IS NO REAL COHERENT BOUNDARY AND THE FORCING
IS QUITE WEAK. IMMEDIATE TRENDS FROM THE RAP SHOW DOWNWARD MOTION
CONTINUING INTO LATE MORNING BEFORE SOME LIFT DEVELOPS AHEAD OF
THE NEXT SHORTWAVE IN THE AFTERNOON. FCST SOUNDINGS SHOW
CONVECTIVE TEMPERATURES CLIMBING INTO THE UPPER 70S WHICH IS RIGHT
AROUND THE MAX TEMPERATURES FOR THE DAY.
SO...WILL CONTINUE THE POSSIBILITY OF ISOLATED
SHOWERS/THUNDERSTORMS ACROSS MAINLY THE NORTHERN CWFA DURING THE
AFTERNOON FOR NOW. THE POSSIBILITY DOES EXIST THAT THE PRECIP
POTENTIAL MAY GET PULLED DEPENDING UPON HOW THINGS EVOLVE DURING
THE AFTERNOON. ..08..
&&
.SYNOPSIS...
ISSUED AT 305 AM CDT WED JUL 31 2013
ANALYSIS AT 07Z (2 AM CDT) DEPICTS AREA UNDER LOW CLOUDS AND FOG AS
REMNANTS OF UPPER DISTURBANCE FROM YESTERDAY MOVES EAST. SURFACE
ANALYSIS PRESSURE RISE AND FALL PATTERN SUPPORTS UPPER AIR AND MOST
SOLUTIONS OF SLIGHTLY DRIER AIR AND SUBSIDENCE TO ARRIVE NEXT
SEVERAL HOURS FROM THE NORTHWEST. NW FLOW TO CONTINUE OVER AREA
NEXT SEVERAL DAYS KEEPING REGION NEAR TO SLIGHTLY BELOW NORMAL
REGARDING TEMPERATURES AS HAS BEEN THE CASE NOW FOR MUCH OF THIS
SUMMER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CDT WED JUL 31 2013
TODAY...ANALYSIS SUPPORTS LOW CLOUDS AND AREAS OF FOG WITH
VISIBILITIES OF 1-3 MILES TO BURN OFF BETWEEN 8-10 AM. SUBSIDENCE
WITH DIFFLUENT LOW LEVEL FLOW AND MIXING SUGGESTS CONVECTIVE
TEMPERATURES UNLIKELY TO BE REACHED AND THUS DRY CONDITIONS
WARRANTED. A WEAK UPPER DISTURBANCE IN SOUTH DAKOTA WILL NEED TO
BE MONITORED BY DAY SHIFT BUT NOWCAST TOOLS SUGGEST IT WILL BE
DRY. LOW LEVEL THERMAL FIELDS AND MODEST BL MIXING INDICATE HIGHS
WITHIN A DEGREE OR TWO OF 80 DEGREES FOR TODAY...A WARM MID SUMMER
DAY WITH DEWPOINTS IN THE LOWER TO MIDDLE 60S FOR MODERATE HUMIDITY.
THESE TEMPERATURES ARE GENERALLY 3 TO 5 DEGREES BELOW NORMAL.
TONIGHT...LIGHT NORTHWEST WINDS SHOULD BRING IN ENOUGH DRIER AIR
AND ENOUGH MIXING TO LIMIT ANY FOG FORMATION TONIGHT. MOSTLY FAIR
SKIES WILL ALLOW FOR MINS IN THE UPPER 50S FAR NW SECTIONS TO THE
LOWER 60S ELSEWHERE. AGAIN THIS IS A FEW DEGREES BELOW NORMAL.
NICHOLS
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 305 AM CDT WED JUL 31 2013
NORTHWEST FLOW WILL KEEP TEMPERATURES BELOW NORMAL THROUGH THE
EXTENDED PERIOD WITH HIGHS GENERALLY IN THE UPPER 70S TO LOWER 80S
AND LOWS IN THE LOWER TO MID 60S.
THE NEXT CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME MAINLY ON
FRIDAY AND THEN AGAIN SUNDAY NIGHT INTO MONDAY AS SIGNIFICANT WAVES
MOVE ALONG IN THE FLOW.
INTERESTING THAT THE 00Z ECMWF HAS BACKED OFF ON SHOWING A POLAR VORTEX
DIVING INTO NORTHERN MN ON AUGUST 8. IT NOW DEPICTS MORE OF A BROAD
TROF IN THE EASTERN UNITED STATES WITH A 1030 MB HIGH DROPPING INTO
THE UPPER MIDWEST WITH 850 MB TEMPERATURES OF +8C INTO THE DVN CWA.
WE SHALL SEE WHAT THE NEXT RUNS SHOW.
HAASE
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 615 AM CDT WED JUL 31 2013
LOW CLOUDS AND AREAS OF FOG WILL DISSIPATE AT ALL THE TERMINALS
BETWEEN 31/12-15Z. THEN...VFR CONDITIONS WILL PREVAIL FOR AT LEAST
THE NEXT 24 HOURS WITH FAIR SKIES AND FEW-SCT COVERAGE OF FAIR
WEATHER CUMULUS CLOUDS WITH BASES AOA 4 K AGL. WINDS WILL BE OUT
OF THE NORTHWEST AT 5 TO 10 MPH OR LESS THROUGH THIS EVENING AND
THEN BECOMING LIGHT TOWARD 01/12Z.
NICHOLS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...NICHOLS
SHORT TERM...NICHOLS
LONG TERM...HAASE
AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
917 PM CDT Thu Aug 1 2013
.UPDATE...
ISSUED AT 917 PM CDT THU AUG 1 2013
Convection continues to progress south southeast similar to what
the backward propagating Corfidi vectors would forecast...and
latest LAPS analysis shows the axis of low level moisture
convergence over northern KS. The HRRR has shown good consistency
with bringing the MCS into the area overnight...and with the RAP
and NAM continuing to show the advection of high theta-e air into
northeast KS with persistent isentropic upglide...hard to see what
would cause the MCS to fall apart before moving across the area. With
increasing confidence that the MCS will track across the
area...have increased pops and gone with categorical wording into
Friday morning.
UPDATE ISSUED AT 610 PM CDT THU AUG 1 2013
Convection across eastern NEB continues to propagate south
southeast as the backward propagating Corfidi vectors would
forecast. Think that as the low level jet veers to the southwest
and continues to advect moisture into northeast KS...that the
storms in NEB should hold together and move into the forecast
area. The HRRR appears to have a reasonable handle on this
convection and would expect it to move into northeastern KS
between 10 pm and midnight. RAP and NAM progs suggest that the
boundary layer will be stabilizing by then so there continues to
be some uncertainty in potential for severe storms. Steep mid
level lapse rates initially as the storms move south and deep
layer sheer around 40 kts would be supportive from some organized
storms. Although it still looks like some kind of MCS will
propagate across the area overnight tonight rather than discrete
storms making strong wind gusts more of a concern if the boundary
layer does not stabilize as forecast.
&&
.SHORT TERM...(THIS EVENING THROUGH Friday)
ISSUED AT 347 PM CDT THU AUG 1 2013
Surface high pressure has slid off to the southeast this afternoon
with light southerly flow building into the area. The atmosphere
remains quite moist in the low levels with dewpoints in the middle
60s to lower 70s across the forecast area while temperatures have
risen into the upper 80s. These low level conditions have combined
with moderate lapse rates to produce a moderately unstable airmass
across central and eastern Kansas. Any cap appears to be quite weak
this afternoon but low level convergence and upper forcing are both
at a minimum, and most signs point to little to no convection
through the afternoon hours. However, a short wave trough moving
from South Dakota into Nebraska this afternoon has helped kick off a
few clusters of severe thunderstorms near the Nebraska border and
this activity is expected to move south and southeast this evening.
While the activity over Nebraska will initially be supercellular in
nature, expect it to eventually congeal cold pools and surge to the
south, likely with forward propagating segments and LEWP structures
and perhaps with embedded areas of mid level supercell rotation.
Instability will weaken a bit into the evening hours but should
still be sufficient when paired with large hodographs and strong
deep layer shear to pose a threat for severe weather as it moves
into eastern Kansas. The primary question at the current time is the
strength of the cap that will develop later in the evening. Most
model forecast soundings suggest that the cap does develop but if an
organized cold pool can lift parcels to 5 or 6 thousand feet, it
should be able to maintain surface based convection. Based on the
strength of the activity ongoing, would tend to believe that surface
based strong to severe convection could persist at least into
northern Kansas, and perhaps across the entire area as the MCS dives
south. The primary severe threat would seem to be damaging winds
although there is at least marginal potential for large hail
especially if some supercell characteristics can be maintained. The
tornado threat appears to be very very small. Will also have to
monitor potential for flooding in case the forward propagation of
the system stops and the low level jet kicks into existing
boundaries.
Expect remnant showers and convection to be ongoing Friday morning,
and any outflow boundaries will play a large role in thunderstorm
and severe weather potential for Friday afternoon. As of now, expect
a slightly better chance of outflow pushing all the way through the
forecast area, potentially keeping some of the area stable by
afternoon. However, if the sun comes out to quickly warm the post
outflow airmass, could see a fairly good severe weather setup by
afternoon. For now, there are too many uncertainties to get
specific, but the potential for storms certainly exists.
Barjenbruch
.LONG TERM...(Friday NIGHT THROUGH Thursday)
ISSUED AT 347 PM CDT THU AUG 1 2013
Friday night through Thursday...
Friday night as the LLJ increases moisture convergence develops
across NE KS which may be the focus for additional thunderstorm
development as the sfc front slowly progresses into the southern
portion of the CWA. The better chances for precip appear to be
across east central KS, although not confident if the lift will be
strong enough to get convection started. On Saturday during the day
the front continues to move south into OK as weak shortwave
disturbances slide eastward along the northern edge of the mid/upper
level high. This lift may cause an isolated shower or thunderstorm
across the southern CWA, but most areas will likely be dry. On
Saturday night a stronger shortwave is forecast to approach the area
from the central Rockies bringing the chances for rain therefore
pops increase during the overnight hours. The best chance for rain
will be Sunday as the deep layer moisture increases ahead of the
shortwave and warm air advection spreads eastward out of western KS.
High temperatures on Saturday will be in the mid to upper 80s and
slightly cooler on Sunday with cloud cover and rain chances.
Monday through Thursday...
The area remains under NW mid/upper level flow as the upper high
anchors over the southern Plains. Shortwaves embedded within the
flow are forecast to bring numerous rain chances to the area. Around
mid week a stronger mid/upper level low will dive southward into
southern Canada suppressing the ridge out west bringing more of a
zonal flow to the Central Plains. High temperatures will continue to
be below average with the chances of rain.
Sanders
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Friday EVENING)
ISSUED AT 610 PM CDT THU AUG 1 2013
Based on RAP and NAM progs of continued moisture advection into
northeast KS with decent convergence...confidence is increasing
that precip will move across the area overnight. Tracking the
convection to the north and with Corfidi vectors suggesting a
south southeast movement around 25 KT...think the most likely
timing for storms will be between 08Z and 15Z. The boundary layer
is expected to stabilize before the convection moves in. This
introduces some uncertainty in how intense the storms could be. For
now think that precip could end up being more stratiform with
embedded TS as CIN values increase to over 200 J/KG. The RAP is
showing MVFR CIGS moving in behind the precip. With little or no
support for this from objective guidance or forecast soundings...
have left the forecast VFR and will monitor trends.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...BARJENBRUCH
LONG TERM...SANDERS
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
610 PM CDT Thu Aug 1 2013
.UPDATE...
ISSUED AT 610 PM CDT THU AUG 1 2013
Convection across eastern NEB continues to propagate south
southeast as the backward propagating Corfidi vectors would
forecast. Think that as the low level jet veers to the southwest
and continues to advect moisture into northeast KS...that the
storms in NEB should hold together and move into the forecast
area. The HRRR appears to have a reasonable handle on this
convection and would expect it to move into northeastern KS
between 10 pm and midnight. RAP and NAM progs suggest that the
boundary layer will be stabilizing by then so there continues to
be some uncertainty in potential for severe storms. Steep mid
level lapse rates initially as the storms move south and deep
layer sheer around 40 kts would be supportive from some organized
storms. Although it still looks like some kind of MCS will
propagate across the area overnight tonight rather than discrete
storms making strong wind gusts more of a concern if the boundary
layer does not stabilize as forecast.
&&
.SHORT TERM...(THIS EVENING THROUGH Friday)
ISSUED AT 347 PM CDT THU AUG 1 2013
Surface high pressure has slid off to the southeast this afternoon
with light southerly flow building into the area. The atmosphere
remains quite moist in the low levels with dewpoints in the middle
60s to lower 70s across the forecast area while temperatures have
risen into the upper 80s. These low level conditions have combined
with moderate lapse rates to produce a moderately unstable airmass
across central and eastern Kansas. Any cap appears to be quite weak
this afternoon but low level convergence and upper forcing are both
at a minimum, and most signs point to little to no convection
through the afternoon hours. However, a short wave trough moving
from South Dakota into Nebraska this afternoon has helped kick off a
few clusters of severe thunderstorms near the Nebraska border and
this activity is expected to move south and southeast this evening.
While the activity over Nebraska will initially be supercellular in
nature, expect it to eventually congeal cold pools and surge to the
south, likely with forward propagating segments and LEWP structures
and perhaps with embedded areas of mid level supercell rotation.
Instability will weaken a bit into the evening hours but should
still be sufficient when paired with large hodographs and strong
deep layer shear to pose a threat for severe weather as it moves
into eastern Kansas. The primary question at the current time is the
strength of the cap that will develop later in the evening. Most
model forecast soundings suggest that the cap does develop but if an
organized cold pool can lift parcels to 5 or 6 thousand feet, it
should be able to maintain surface based convection. Based on the
strength of the activity ongoing, would tend to believe that surface
based strong to severe convection could persist at least into
northern Kansas, and perhaps across the entire area as the MCS dives
south. The primary severe threat would seem to be damaging winds
although there is at least marginal potential for large hail
especially if some supercell characteristics can be maintained. The
tornado threat appears to be very very small. Will also have to
monitor potential for flooding in case the forward propagation of
the system stops and the low level jet kicks into existing
boundaries.
Expect remnant showers and convection to be ongoing Friday morning,
and any outflow boundaries will play a large role in thunderstorm
and severe weather potential for Friday afternoon. As of now, expect
a slightly better chance of outflow pushing all the way through the
forecast area, potentially keeping some of the area stable by
afternoon. However, if the sun comes out to quickly warm the post
outflow airmass, could see a fairly good severe weather setup by
afternoon. For now, there are too many uncertainties to get
specific, but the potential for storms certainly exists.
Barjenbruch
.LONG TERM...(Friday NIGHT THROUGH Thursday)
ISSUED AT 347 PM CDT THU AUG 1 2013
Friday night through Thursday...
Friday night as the LLJ increases moisture convergence develops
across NE KS which may be the focus for additional thunderstorm
development as the sfc front slowly progresses into the southern
portion of the CWA. The better chances for precip appear to be
across east central KS, although not confident if the lift will be
strong enough to get convection started. On Saturday during the day
the front continues to move south into OK as weak shortwave
disturbances slide eastward along the northern edge of the mid/upper
level high. This lift may cause an isolated shower or thunderstorm
across the southern CWA, but most areas will likely be dry. On
Saturday night a stronger shortwave is forecast to approach the area
from the central Rockies bringing the chances for rain therefore
pops increase during the overnight hours. The best chance for rain
will be Sunday as the deep layer moisture increases ahead of the
shortwave and warm air advection spreads eastward out of western KS.
High temperatures on Saturday will be in the mid to upper 80s and
slightly cooler on Sunday with cloud cover and rain chances.
Monday through Thursday...
The area remains under NW mid/upper level flow as the upper high
anchors over the southern Plains. Shortwaves embedded within the
flow are forecast to bring numerous rain chances to the area. Around
mid week a stronger mid/upper level low will dive southward into
southern Canada suppressing the ridge out west bringing more of a
zonal flow to the Central Plains. High temperatures will continue to
be below average with the chances of rain.
Sanders
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Friday EVENING)
ISSUED AT 610 PM CDT THU AUG 1 2013
Based on RAP and NAM progs of continued moisture advection into
northeast KS with decent convergence...confidence is increasing
that precip will move across the area overnight. Tracking the
convection to the north and with Corfidi vectors suggesting a
south southeast movement around 25 KT...think the most likely
timing for storms will be between 08Z and 15Z. The boundary layer
is expected to stabilize before the convection moves in. This
introduces some uncertainty in how intense the storms could be. For
now think that precip could end up being more stratiform with
embedded TS as CIN values increase to over 200 J/KG. The RAP is
showing MVFR CIGS moving in behind the precip. With little or no
support for this from objective guidance or forecast soundings...
have left the forecast VFR and will monitor trends.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...BARJENBRUCH
LONG TERM...SANDERS
AVIATION...WOLTERS
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
116 PM MDT WED JUL 31 2013
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 116 PM MDT WED JUL 31 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS AMPLIFIED RIDGE ACROSS
THE INTER-MOUNTAIN WEST WITH NW FLOW IN PLACE ACROSS THE HIGH
PLAINS. AT THE SURFACE A COLD FRONT IS CURRENTLY IN PLACE ACROSS
CENTRAL NEBRASKA WITH SEVERAL AREAS OF WEAK CONVERGENCE ALONG A PRE
FRONTAL TROUGH THROUGH THE CENTRAL PART OF OUR CWA...AND POSSIBLY
SEVERAL OTHER WEAK SURFACE FEATURES ASSOCIATED WITH OLD OUTFLOW FROM
OVERNIGHT CONVECTION IN THE EAST.
LATEST RAP ANALYSIS INDICATES SBCAPE IN EXCESS OF 3000 J/KG...AND
PWAT VALUES 1-1.5 INCHES ACROSS OUR CWA. THIS VERY MOIST AND
UNSTABLE AIRMASS HAS COMBINED WITH PREVIOUSLY MENTIONED SURFACE
FEATURES TO DEVELOPMENT OF SEVERAL ISOLATED THUNDERSTORMS ACROSS
THE SOUTHERN PART OF OUR CWA. WITH CU FIELD IN PLACE AND
FORCING INCREASING AHEAD OF APPROACHING COLD FRONT I WOULD
ANTICIPATE THUNDERSTORM COVERAGE TO INCREASE THROUGH THIS
AFTERNOON. RAP ALSO INDICATES 0-6KM BULK SHEER IN EXCESS OF 40KT
ACROSS THE SOUTHEASTERN HALF OF OUR CWA...AND WITH LLJ INCREASING
AROUND 00Z I WOULD EXPECT SHEER TO ONLY INCREASE. WHILE I AM
MAINLY ANTICIPATING HAIL/WIND/MULTI-CELL THREAT THROUGH
TONIGHT...TORNADOES COULDNT BE RULED OUT WITH SUPERCELLS THAT
DEVELOP CONSIDERING THE LARGE SCALE SHEER PROFILES. A SEVERE
THUNDERSTORM WATCH HAS ALREADY BEEN ISSUED FOR THE SOUTHERN HALF
OF OUR CWA...AND IF ADDITIONAL ACTIVITY DEVELOPS FURTHER NORTH OF
WATCH WE MAY NEED TO DO A LOCAL EXPANSION CONSIDERING THE
ENVIRONMENT.
WITH 0-6KM STORM MOTION GENERALLY TO THE SOUTHEAST MOST ACTIVITY
SHOULD BE TRANSITIONING OUT OF OUR CWA THIS EVENING...THOUGH WITH
GOOD THETA-E CONVERGENCE AHEAD OF LLJ WE SHOULD SEE ADDITIONAL
DEVELOPMENT TONIGHT ESPECIALLY ACROSS THE NORTHEAST.
.LONG TERM...(TOMORROW THROUGH WEDNESDAY)
ISSUED AT 1244 PM MDT WED JUL 31 2013
THE UPPER PATTERN THIS PERIOD WILL FEATURE A RIDGE CENTERED OVER
TEXAS AND OCCASIONAL SHORTWAVE TROUGHS MOVING OUT OF THE CENTRAL
AND NORTHERN ROCKIES ACROSS THE PLAINS. THIS MEANS THE SAME OLD
STORY THAT HAS BEEN RUNNING A FEW WEEKS NOW: DAILY CHANCES FOR
SHOWERS AND THUNDERSTORMS AND TEMPERATURES NEAR NORMAL. MESOSCALE
DETAILS WILL ULTIMATELY PLAY A LARGE ROLE IN DETERMINING WHERE
BETTER THUNDERSTORM CHANCES WILL BE ON ANY GIVEN DAY...BUT THEY
ARE DIFFICULT TO PREDICT BEYOND A DAY OR TWO AT BEST. AS A
RESULT...POPS WILL BE RATHER BROADBRUSHED ACROSS THE AREA. ON
THURSDAY...SEVERE STORMS WILL BE POSSIBLE GIVEN SUFFICIENT
INSTABILITY AND FAVORABLE SHEAR PROFILES. SEVERE POTENTIAL FOR THE
REMAINDER OF THE PERIOD WILL BE TIED TO SHORTWAVE IMPULSES WITH
LOW PREDICTABILITY AT THIS TIME RANGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1133 AM MDT WED JUL 31 2013
SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON
AHEAD OF APPROACHING COLD FRONT WITH COVERAGE DECREASING THIS
EVENING. THUNDERSTORMS WILL THEN REDEVELOP WITH SUPPORT FROM LOW
LEVEL JET AND LINGERING MOISTURE/INSTABILITY. BEST CHANCE FOR
THUNDERSTORMS THIS AFTERNOON/EVENING SHOULD BE SOUTHEAST OF BOTH
TERMINALS...WITH KGLD MOSTLY LIKELY TO SEE ACTIVITY AT TERMINAL.
OVERNIGHT ACTIVITY WILL HAVE BEST COVERAGE NEAR KMCK WITH
CLUSTER/COMPLEX OF THUNDERSTORMS DEVELOPING OVER CENTRAL NEBRASKA.
VFR CONDITIONS SHOULD PREVAIL AT BOTH KGLD AND KMCK...THOUGH LOWER
CONDITIONS ARE CERTAINLY POSSIBLE WITH THUNDERSTORM ACTIVITY.
LIGHT FOG MAY ALSO DEVELOP AROUND SUNRISE AT KMCK WITH MOIST
AIRMASS IN PLACE...WHICH COULD RESULT IN MVFR CIGS. CONFIDENCE IS
TOO LOW IN FOG TO ADD TO TAF DUE TO POSSIBLE EFFECTS OF
OVERNIGHT THUNDERSTORM ACTIVITY. WINDS SHOULD GENERALLY REMAIN
12KT OR LESS THROUGH TONIGHT AT BOTH TERMINALS WITH WINDS SHIFTING
TO THE NORTH AND THEN SOUTH- SOUTHEAST BY THURSDAY MORNING. GUSTY
WINDS MAY DEVELOP AT KGLD SHORTLY AFTER SUNRISE...WITH LIGHTER
WINDS AT KMCK WITH FRONT NEARBY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1129 PM MDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 847 PM MDT TUE JUL 30 2013
SMALL AREA OF THUNDERSTORMS OVER FRONTIER COUNTY CONTINUES TO MOVE
SOUTHWARD INTO THE DRIER AIR. DO NOT EXPECT IT TO SUDDENLY
DISSIPATE BEFORE REACHING RED WILLOW COUNTY SO HAVE FAIRLY HIGH
CHANCES FOR PRECIP. CHANCES THERE. PRECIP. CHANCES DECLINE
FURTHER SOUTH SINCE THE STORM WILL CONTINUE TO BE IN THE DRIER AIR
WHICH SHOULD CAUSE IT TO EVENTUALLY DISSIPATE COMPLETELY.
OVERNIGHT A PLUME OF MOISTURE AHEAD OF AN UPPER LEVEL
TROUGH...CURRENTLY OVER WYOMING...WILL MOVE OVER THE NORTHERN PART
OF THE AREA. SOUNDINGS SHOW SOME ELEVATED INSTABILITY AS THE SHORT
WAVE TROUGH MOVES THROUGH. AS A RESULT WILL HAVE SOME SLIGHT
CHANCES GOING DURING THE OVERNIGHT/EARLY MORNING HOURS AS THE
SHORT WAVE TROUGH MOVES THROUGH.
SOUNDINGS OVER THE EASTERN HALF OF THE AREA ARE STILL SUGGESTING
FOG DEVELOPMENT TONIGHT. DO NOT ANTICIPATE IT TO BE AS THICK AS THE
LAST COUPLE OF NIGHTS DUE TO THE RATHER SHALLOW DEPTH TO THE
SATURATION.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 PM MDT TUE JUL 30 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS ELONGATED RIDGE ACROSS
THE SOUTHERN PLAINS WITH WESTERLY FLOW IN PLACE ACROSS THE
CENTRAL/HIGH PLAINS. A WEAK LEE TROUGH IS CURRENTLY IN PLACE ACROSS
EASTERN COLORADO WITH A WEAK CONVERGENCE REGION EXTENDING INTO OUR
WESTERN CWA.
THIS WILL ACT AS THE FOCUS FOR ISOLATED THUNDERSTORM DEVELOPMENT
THIS AFTERNOON...WITH CU FIELD ALREADY IN PLACE AND RADAR INDICATING
SEVERAL DEVELOPING UPDRAFTS JUST NW OF OUR CWA NEAR YUMA COUNTY. WITH
STORM MOTIONS OUT OF THE EAST 10-20KT MOST STORMS WILL BE SLOW
MOVERS...THOUGH WE COULD STILL SEE THIS ACTIVITY MOVE FURTHER EAST
IN OUR CWA THROUGH THE AFTERNOON BEFORE FALLING APART AFTER SUNSET
WITH LOSS OF DAYTIME HEATING AND INCREASING LOW LEVEL CINH. LATEST
RAP ANALYSIS SHOWS SB/ML CAPE VALUES RANGING FROM 1000-1500
J/KG...AND WITH ADJUSTED SOUNDINGS SUPPORTING POSSIBLE CAPE VALUES
IN THE 2000-2500J/KG RANGE LATER THIS AFTERNOON. WITH HIGH TD
DEPRESSIONS TO ABOUT 700MB THROUGH A DRY ADIABATIC AIR MASS AND HIGH
LFC/LCL IN THE 10-13KFT RANGE WE COULD SEE STRONG THUNDERSTORM GUST
POTENTIAL. IF WE REALIZE THE HIGHER CAPE VALUES I COULDNT RULE OUT
LARGE HAIL POTENTIAL...HOWEVER AT THIS POINT STRONG WINDS ARE
PROBABLY THE GREATER THREAT WITH ANY THUNDERSTORMS THAT DEVELOP.
MET/MAV GUIDANCE ARE INDICATING FOG DEVELOPMENT TONIGHT...HOWEVER
WITH W-SW WINDS TO 10KT AT THE SURFACE AND BL WINDS IN EXCESS OF
20KT...I AM NOT AS CONFIDENT WE WILL SEE A REPEAT OF LAST NIGHT.
WITH TROUGH AXIS SHIFTING EAST WE COULD STILL SEE LIGHT SURFACE
WINDS IN THE EAST WHERE FOG WOULD BE MORE LIKELY TO OCCUR...AND
WHERE I KEPT PATCHY FOG MENTION.
A WEAK COLD FRONT WILL DROP SOUTH LATE TONIGHT AND STALL ALONG THE
NE/KS STATE LINE BY MIDDAY WEDNESDAY WITH A PRE FRONTAL TROUGH
SETTLING TO OUR SOUTHEAST. AHEAD OF THE TROUGH AXIS CAPE VALUES IN
EXCESS OF 2500 J/KG ARE ADVERTISED. THIS TROUGH AXIS WILL BE THE
MAIN FOCUS WITH GOOD SURFACE CONVERGENCE IN PLACE...AND I KEPT 30/40
POPS TIED TO THIS FEATURE...AND LOWER POPS TO THE NORTH. WITH BETTER
CAPE AND MARGINALLY BETTER SHEER WE WILL SEE A CHANCE FOR
THUNDERSTORMS TO BECOME BETTER ORGANIZED WITH SEVERE WIND/HAIL A
POSSIBILITY IN OUR SOUTHEAST DURING THE AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 250 PM MDT TUE JUL 30 2013
NO MAJOR CHANGES SEEN TO THE UPPER PATTERN ACROSS THE SOUTHERN AND
CENTRAL PLAINS DURING THIS PERIOD. UPPER HIGH NOW CENTERED OVER
NEW MEXICO AND WAFFLE BACK AND FORTH OVER TO WEST TEXAS AND BACK DURING
PERIOD. ALTHOUGH THE UPPER RIDGE IS FORECAST TO ASSERT ITSELF SLIGHTLY
NORTH OVER THE MOUNTAINS...A SERIES OF WEAK UPPER IMPULSES WILL
CONTINUE TO MOVE OVER THE TOP OF THE RIDGE KEEPING IT FAIRLY
FLAT OVERALL.
THIS MAKES IT DIFFICULT TO ASSESS TIMING OF PRECIPITATION. ALL
GUIDANCE IS SUGGESTING AN ACTIVE FLOW REGIME WILL CONTINUE WITH
SLIGHT CHANCE TO CHANCE POPS EVERY DAY. RIGHT NOW THE MOST ACTIVE
PERIODS FOR PRECIPITATION LOOK TO BE THURSDAY NIGHT AND AGAIN
SATURDAY NIGHT. TEMPERATURES WILL CONTINUE SEASONAL WITH HIGHS
MOSTLY IN THE UPPER 80S TO LOWER 90S AND LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1108 PM MDT TUE JUL 30 2013
MVFR TO VFR CONDITIONS FORECAST FOR THE 6Z TAFS. LATEST RADAR
SHOWS AN AREA OF STORMS OVER SOUTHWEST NEBRASKA MOVING TO THE
SOUTHEAST. IF STORMS KEEP THEIR CURRENT COURSE/SPEED THEY WILL BE
MOVING OVER KMCK AROUND 6Z. BASED ON OGALLALA/S OBSERVATION IFR
CONDITIONS ARE POSSIBLE WHEN THE STORM MOVES THROUGH KMCK. HOWEVER
THE STORMS SHOULD BE MOVING OUT OF THE LOW LEVEL JET BY THE TIME
THEY ARE NEAR KMCK...SO THEIR INTENSITY SHOULD DIMINISH. THE
OBSERVATION FROM KIML WILL HELP DECIDE HOW LOW TO GO FOR KMCK..BUT
AM HESITANT TO GO TOO LOW SINCE THE STORM SHOULD BE WEAKENING BY
THEN. OTHERWISE ISOLATED TO SCATTERED STORMS WILL BE POSSIBLE FOR
KMCK UNTIL ALMOST THE EARLY MORNING AHEAD OF AN UPPER LEVEL TROUGH
THAT WILL MOVE THROUGH AROUND 12Z. THERE COULD BE SOME FOG LATE
TONIGHT FOR KMCK. SOUNDINGS ARE NOT TOO FAVORABLE FOR FOG
DEVELOPMENT...BUT MCK HAS FAIRLY HIGH DEW POINTS AND HAS NOT YET
CHANGED AIR MASSES...SO WILL PLACE A MENTION OF FOG IN THE TAF FOR
NOW.
WEDNESDAY STORMS SHOULD INITIALLY DEVELOP DURING THE EARLY
AFTERNOON ALONG A WEAK COLD FRONT. AS THE DAY PROGRESSES THE COLD
FRONT WILL MOVE FURTHER SOUTH...TAKING THE STORMS WITH IT. STORM
COVERAGE NEAR THE SITES SHOULD DECLINE THROUGH THE AFTERNOON AS A
RESULT. THERE MAY BE SOME MORE WIDELY SCATTERED STORMS DURING THE
EVENING AS SOME ELEVATED INSTABILITY WILL BE IN PLACE AS ANOTHER
SHORT WAVE TROUGH MOVES THROUGH...BUT WILL LEAVE OUT A MENTION OF
STORMS FOR THIS TIME FRAME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...DR
LONG TERM...DLF
AVIATION...JTL
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1207 AM CDT WED JUL 31 2013
...UPDATED FOR AVIATION...
.UPDATE...
ISSUED AT 630 PM CDT TUE JUL 30 2013
HAVE A CONCERN THROUGH THE OVERNIGHT HOURS FOR DENSE FOG. WET GROUNDS
FROM ANTECEDENT RAINS AND CALM WINDS WILL CREATE AN ENVIRONMENT THAT
IS CONDUCIVE FOR DENSE FOG. THIS IS SUGGESTED WITH HRRR AND BUFKIT GUIDANCE
AS WELL AS SOME MOS GUIDANCE. AS A RESULT, HAVE ISSUED A DENSE FOG ADVISORY.
SECOND CONCERN WAS TO REMOVE ANY STORM CHANCES THIS EVENING AS ACTIVITY
IS NORTHWEST KANSAS IS WEAKENING AND CUMULUS ACROSS THE KANSAS/COLORADO
BORDER IS NOT UNDERGOING ADEQUATE VERTICAL GROWTH.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 156 PM CDT TUE JUL 30 2013
TODAY IS SEEING A VERY SLOW CLEARING PATTERN IN THE CLOUDS FROM
WEST TO EAST. THIS SLOWNESS IN CLEARING IS PARTIALLY DUE TO THE
NORTH TO NORTHEAST LOW LEVEL FLOW, WHICH IS A SLIGHT UPSLOPE
PATTERN. THE OTHER REASON THE EAST IS SO SLOW TO CLEAR OUT IS THE
ABUNDANT SURFACE MOISTURE ACROSS OUR EASTERN ZONES, WITH PLENTY OF
LEFTOVER RAINFALL STILL ACROSS MUCH OF THE EASTERN FORECAST AREA,
ESPECIALLY SOUTHEAST OF A LINE FROM LA CROSSE TO ASHLAND. SOME OF
THESE COUNTIES RECEIVED OVER 3 INCHES OF RAINFALL MONDAY EVENING,
ESPECIALLY ACROSS PRATT AND BARBER COUNTIES. FOR THIS REASON, ALONG
WITH EXPECTED CLEAR SKIES AND LIGHT WINDS EXPECTED, THERE SHOULD
BE SOME MORE FOG FORM TOWARD 09Z TO 10Z. I HAVE DECIDED TO PUT IN
PATCHY FOG WORDING FOR NOW ACROSS OUR SOUTHEASTERN SECTIONS, AND
LATER SHIFTS CAN UPDATE TO DENSE FOG IF IT FORMS. BOTH THE NAM
AND THE HRRR MODELS ARE INDICATED AROUND 1SM VISIBILITIES IN FOG.
AS FOR LOW TEMPERATURES, NO CHANGES WERE MADE TO THE PREVIOUS
FORECAST. CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO
DROP TO THE MID 60S IN OUR WEST AND THE UPPER 60S IN OUR
SOUTHEAST.
MOSTLY SUNNY SKIES AREA EXPECTED WEDNESDAY, AFTER SOME SCATTERED
MORNING FOG. WINDS WILL BE LIGHT AND VARIABLE EARLY, THEN SHIFT TO
THE SOUTHEAST IN THE AFTERNOON AT 10 TO 20 MPH. A COLD FRONT
WILL APPROACH WESTERN KANSAS BY AFTERNOON. THE NAM MODEL BRINGS IN
THUNDERSTORMS WEDNESDAY AFTERNOON AS EARLY AS 19Z IN OUR NORTHWEST
ZONES OF SCOTT AND LANE COUNTIES, AND ADVANCES THE RAIN TOWARD
DODGE CITY AS EARLY AS 22Z. THE ECMWF AND GFS MODELS ARE A LITTLE
SLOWER, BRINGING RAIN TO SCOTT AND LANE COUNTIES AFTER 22Z AND NOT
NEAR DODGE CITY UNTIL AFTER 02Z. HAVE STARTED SLIGHT 20 PERCENT
CHANCES IN OUR FAR NORTHWEST, SUCH AS SCOTT AND LANE COUNTIES, AND
DELAYED THE ONSET OF CHANCE POP CATEGORIES IN THE DODGE CITY AREA
UNTIL 03Z. SOME OF THE LATE AFTERNOON AND EVENING STORMS COULD
CONTAIN DAMAGING WINDS AND HAIL AS LARGE AS GOLF BALLS. THE FRONT
WILL MOVE THROUGH WESTERN AND INTO CENTRAL KANSAS BY WEDNESDAY
EVENING, BRINGING RAIN CHANCES FOR SHOWERS AND THUNDERSTORMS TO
THE PRATT AND COLDWATER AREAS AFTER 00Z THURSDAY. WITH SKIES
STARTING OUT WEDNESDAY MORNING AS MOSTLY SUNNY, THEN BECOMING
PARTLY CLOUDY BY MID TO LATE AFTERNOON, AND POSSIBLY EVEN MOSTLY
CLOUDY BY EVENING, MAXIMUM TEMPERATURES COULD BE A LITTLE TRICKY.
STAYED WITH THE PREVIOUS FORECAST OF MID 90S IN THE WEST AND NEAR
90F IN THE EAST. HOW MUCH RAIN WILL FALL IS ALWAYS A LITTLE
CHALLENGING, BUT I THINK THE QPF_FM_POP PROCEDURE DID A FAIRLY
GOOD JOB WITH FORECAST RAINFALL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 PM CDT TUE JUL 30 2013
AN UPPER LEVEL LONGWAVE TROUGH WILL GENERALLY RESIDE OVER THE EASTERN
UNITED STATES THROUGH TUESDAY AUGUST 6TH, WITH UPPER LEVEL RIDGING
WAFFLING BACK AND FORTH BETWEEN NEW MEXICO AND TEXAS. ALONG THE
NORTHERN PERIPHERY OF THE RIDGE OVER THE CENTRAL HIGH PLAINS, A
QUASI-STATIONARY SURFACE FRONTAL BOUNDARY WILL EXIST, WITH LOW
LEVEL MOISTURE CONVERGING ALONG AND NORTH OF THE BOUNDARY.
ADDITIONALLY, EVAPOTRANSPIRATION FROM THE PREVIOUS HEAVY RAINS
ACROSS THE SOUTHERN AND CENTRAL PLAINS AND SUBSEQUENT TRANSPORT OF
THIS MOISTURE TO THE NORTHWEST WITH THE LOW LEVEL FLOW, WILL
ENHANCE MIXING RATIOS EVEN FURTHER. CONVECTIVE CLUSTERS WILL
ORIGINATE OFF OF THE VARIOUS TERRAIN FEATURES IN THE LEE OF THE
ROCKIES JUST ABOUT EVERY DAY, AND A FEW OF THESE COULD GROW
UPSCALE INTO LARGER CONVECTIVE CLUSTERS AND AFFECT WESTERN KANSAS
THROUGH AUGUST 6TH. THE TIMING OF THE INDIVIDUAL STORM CLUSTERS
CANNOT BE PREDICTED WITH MUCH ACCURACY IN THIS REGIME. THEREFORE,
20 TO 40% STORM CHANCES WERE GENERALLY MAINTAINED THROUGH AUGUST
6TH. ALSO, GIVEN THE UNCERTAINTY IN ANY CONVECTION AND RESULTANT
COOL OUTFLOW, HIGH TEMPERATURES WILL BE TRICKY AS WELL. OUR BEST
ESTIMATE IS THAT HIGH AND LOW TEMPERATURES WILL BE WITHIN A FEW
DEGREES OF CLIMATOLOGICAL VALUES (HIGHS 86-97F AT DODGE CITY, WITH
COOLER READINGS THAN THIS NEAR INTERSTATE 70 AND WARMER READINGS
NEAR THE OKLAHOMA STATE LINE). KEEP IN MIND THAT ANY WIDESPREAD
CLOUD COVER OR RAINFALL COULD LEAD TO MUCH COOLER TEMPERATURES ON
ANY GIVEN DAY.
AFTER AUGUST 6TH, THE VARIOUS MODELS ARE ADVERTISING A STRONG UPPER
LEVEL LOW TO DROP SOUTHWARD OUT OF CANADA INTO THE GREAT LAKES
REGION. THE ASSOCIATED COLD FRONT COULD BRING MUCH COOLER AIR INTO THE
CENTRAL PLAINS BY LATE NEXT WEEK, WITH HIGHS POSSIBLY FALLING INTO
THE 70S DEPENDING ON THE AMOUNT OF ACCOMPANYING CLOUD COVER AND
PRECIPITATION BEHIND THE FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1202 AM CDT WED JUL 31 2013
AREAS OF GROUND FOG WITH VSBYS LESS THAN 1 MILE ARE POSSIBLE
THROUGH 14-15Z, THEN EXPECT VFR CONDITIONS. A COMPLEX OF
THUNDERSTORMS IS THEN FORECAST TO DEVELOP NEAR KGCK BY 23-02Z AND
DROP SOUTH WITH SOME SEVERE. KDDC AND KHYS MAY BE CLOSE OR GET
INTO THE ACTIVITY LATER.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 93 71 97 / 30 30 30 20
GCK 68 94 71 96 / 40 30 30 20
EHA 67 95 71 97 / 40 30 30 20
LBL 69 95 72 97 / 40 30 30 20
HYS 68 92 71 89 / 30 40 40 20
P28 70 94 73 93 / 10 20 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CDT THIS MORNING FOR KSZ031-046-
065-066-079>081-089-090.
&&
$$
UPDATE...SUGDEN
SHORT TERM...BURKE
LONG TERM...FINCH
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS JACKSON KY
158 PM EDT WED JUL 31 2013
.UPDATE...
ISSUED AT 158 PM EDT WED JUL 31 2013
THE SYSTEM MOVING INTO THE AREA TURNED OUT TO BE MUCH WEAKER THAN
INDICATED ON THE MODELS...SO UPDATED THE FORECAST TO DECREASE THE
AMOUNT OF RAIN EXPECTED AND TO DECREASE THE HIGH TEMPERATURES FOR
TODAY. THE REST OF THE FORECAST IS ON TRACK.
UPDATE ISSUED AT 1130 AM EDT WED JUL 31 2013
UPDATED THE FORECAST TO BETTER TIME THE PRECIPITATION INTO THE AREA
BASED ON MODEL SOUNDINGS AND CURRENT RADAR ACTIVITY...DECREASED THE
COVERAGE AND TIMING FOR THUNDERSTORMS TODAY AND TOOK THE THUNDER OUT
OF THE TONIGHT FORECAST. STILL HAVE SOME CONCERN THAT THIS SYSTEM IS
GOING TO STAY FURTHER SOUTH THAN WHAT IS CURRENTLY FORECAST. MAY
HAVE TO DECREASE THE PROBABILITY OF PRECIPITATION FOR AREAS NORTH OF
THE MOUNTAIN PARKWAY. MAKE SOME MORE ADJUSTMENTS DURING THE 2 PM
UPDATE.
UPDATE ISSUED AT 755 AM EDT WED JUL 31 2013
HOURLY TEMP AND DEWPOINTS WERE FRESHENED UP BASED ON RECENT OBS.
UPSTREAM RADAR RETURNS STILL FAVOR HIGHER POPS IN THE FAR SOUTH. NO
SUBSTANTIAL CHANGES WERE MADE AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED JUL 31 2013
A SHORTWAVE IS CURRENTLY WORKING THROUGH THE OH VALLEY REGION IN
WEST NORTHWEST FLOW...BUT IS PRODUCING ONLY LIGHT RAIN SHOWERS
LOCALLY. A RIDGE OF HIGH PRESSURE WAS CENTERED OVER THEE SOUTHERN
ROCKIES WITH AN UPPER LEVEL LOW AND TROUGH CONTINUING TO EXIT THE
NORTHEASTERN CONUS INTO THE MARITIMES. ALSO IN THE NORTHERN
STREAM...A SHORTWAVE TRACKING NEAR THE US/CANADIAN BORDER IS
APPROACHING THE UPPER MS VALLEY AND WESTERN ONTARIO. HEAVIER
PRECIPITATION THUS FAR HAS BEEN CONFINED TO SOUTHERN MIDDLE AND
EASTERN TN AND THE NORTHERN GULF COAST STATES. THERE HAS ALSO BEEN A
SLIGHT INCREASE IN CONVECTION OVER WESTERN KY.
THE SHORTWAVE NOW WORKING THROUGH THE OH VALLEY AND INTO THE
APPALACHIAN REGION AND THE SHORTWAVE WORKING TOWARD THE WESTERN GREAT
LAKES WILL EVENTUALLY BECOME A BIT MORE PHASED BY THUS AND LEAD TO A
RETURN TO A MORE AMPLIFIED EASTERN/NORTHEASTERN CONUS THROUGH AND
ROCKIES/PLAINS RIDGE. MEANWHILE A SFC LOW IS LAGGING THE UPPER LEVEL
SHORTWAVE WORKING THROUGH THE OH VALLEY. THIS LOW WILL DRIFT THROUGH
THE LOWER OH VALLEY REGION AND REACH CENTRAL KY THIS EVENING...EVENTUALLY
BECOMING DIFFUSE AND MORE OR LESS MERGING WITH A COLD FRONT ASSOCIATED
WITH THE TROUGH WORKING THROUGH ONTARIO AND THE GREAT LAKES REGION
TONIGHT AND INTO THURSDAY. THE SFC COLD FRONT SHOULD CROSS THE CWA ON
THURSDAY.
THE 0Z NAM AND THE 4Z HRR GENERALLY INDICATE REDEVELOPMENT OF
STRONGER CONVECTION THAN THE LIGHT SHOWERS CURRENTLY OVER THE CWA
TOWARD DAWN AND THEN WORK THIS INTO EASTERN KY THIS MORNING AND INTO
THIS AFTERNOON. THE NAM HAS BULLSEYE OF QPF OVER THE LAKE CUMBERLAND
REGION...BUT MUCH OF THE OTHER GUIDANCE HAS HIGHER QPF NEAR THE TN
BORDER...AND IS NOT NEARLY AS MUCH. CONFIDENCE IN THE EVOLUTION OF
THIS CONVECTION IS BELOW AVERAGE...BUT THE MODEL CONSENSUS IS THAT
BEST CHANCES SHOULD BE ACROSS THE SOUTH TODAY. THE 5Z HRRR HAS THROWN
A BIT MORE UNCERTAINTY INTO THE PICTURE...ESPECIALLY ACROSS THE NORTH
WITH IT SUGGEST COULD LARGELY REMAIN DRY.
WE HAVE OPTED TO GO VERY CLOSE TO HPC QPF WHICH LED TO LOWER AMOUNTS
THAN THE NAM OVER THE SOUTH WITH THE HIGHEST POPS OVER THE SOUTHERN
CWA. HOWEVER...THIS STILL YIELDS NEARLY AN INCH OF RAIN THROUGH
TONIGHT. ALTHOUGH A SHORTWAVE CURRENTLY WORKING THROUGH THE OH VALLEY
AND ANOTHER UPSTREAM WILL WORK ACROSS THE AREA THIS AFTERNOON AND THE
SFC LOW WILL GRADUALLY APPROACH THE AREA...CLOUD COVER SHOULD LIMIT
OVERALL INSTABILITY. THE CLOSEST LIGHTNING AT PRESENT IS OVER WESTERN
KY. THUS WE HAVE KEPT COVERAGE OF THUNDER AT ISOLATED TO SCATTERED
LEVELS THROUGH THIS EVENING WITH HIGHER COVERAGE OF SHOWERS.
HOWEVER... CHANCES FOR CONVECTION WILL LINGER THROUGH MOST OF THE
PERIOD...UNTIL LATE ON THU WHEN A COLD FRONT WILL SWEEP THE DEEPER
MOISTURE EAST AND SOUTHEAST OF THE AREA.
MOS GUIDANCE WAS TOO WARM WITH HIGHS ON TUE AND WE HAVE WENT ON THE
COLDER END OF GUIDANCE FOR MAX T TODAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 AM EDT WED JUL 31 2013
MODELS ARE AGREEING A BIT MORE HEADING INTO THE UPCOMING
WEEKEND...SO CONFIDENCE IN THE FORECAST IS INCREASING. STARTING
THURSDAY NIGHT...HIGH PRESSURE WILL BE BUILDING INTO THE
REGION...SETTING UP A DRY AND PLEASANT END TO THE WEEK. A SHORTWAVE
TROUGH WILL THEN DRAG A SURFACE WARM FRONT BACK TO THE NORTHEAST
LATE FRIDAY NIGHT INTO SATURDAY WITH ISENTROPIC ASCENT DEVELOPING
OVER THE REGION. THIS WILL YIELD THE POTENTIAL FOR A WET PERIOD ON
SATURDAY...AS THE WARM FRONT STALLS OVER THE AREA. A SECONDARY
SHORTWAVE PUSHING ACROSS THE GREAT LAKES WILL THEN DRAG A COLD FRONT
SOUTHWARD ACROSS THE OHIO RIVER VALLEY SATURDAY NIGHT INTO EARLY
SUNDAY...WITH ANOTHER PERIOD OF UNSETTLED WEATHER EXPECTED. THIS
FRONTAL BOUNDARY WILL GET SHOVED SOUTHWARD ON SUNDAY WITH DRY
WEATHER RETURNING TO FINISH OUT THE WEEKEND. HOWEVER...THE ACTIVE
WEATHER WILL CONTINUE AS ANOTHER SHORTWAVE PUSHES EAST INTO THE AREA
ON MONDAY...BRINGING ANOTHER ROUND OF SHOWERS AND PERHAPS A
THUNDERSTORM TO THE AREA. DRIER WEATHER MAY RETURN BY TUESDAY AND
WEDNESDAY...BUT GIVEN THE TROUGH OVER THE REGION...ADDITIONAL WAVES
OF UNSETTLED WEATHER COULD IMPACT THE REGION. HIGHS THROUGH THE
PERIOD WILL BE A TOUCH BELOW NORMAL WITH A GENERAL TROUGH OVER THE
EASTERN US...KEEPING TEMPERATURES UNUSUALLY COOL FOR THIS TIME OF
YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 158 AM EDT WED JUL 31 2013
THE TAF GUIDANCE HAS BEEN ALL OVER THE PLACE AND DID NOT EVEN CAPTURE
CURRENT CONDITIONS VERY WELL. AS SUCH...CONFIDENCE IS A BIT LOWER THAN
NORMAL. A WHOLE LOT IS GOING TO DEPEND ON HOW MUCH RAIN FALLS TONIGHT
AND HOW MUCH CLOUD COVER THERE IS. EXPECT TO SEE SOME VLIFR TONIGHT
AS THERE IS SUFFICIENT LOW LEVEL MOISTURE. THIS IS THE KIND OF
FORECAST WHERE IF YOU DO NOT GET THE VSBY RIGHT...THE STRATUS COULD
STILL PUT THE FORECAST IN THE CORRECT CATEGORY. EXPECTING A COMBINATION
OF THE FOG AND STRATUS TONIGHT WILL THIS FALL LIKE SUMMER SYSTEM.
ALSO EXPECT THE CLEARING TO TAKE LONGER THAN NORM FOR THE MORNING
FORECAST
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJ
SHORT TERM...JP
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1055 AM CDT WED JUL 31 2013
.UPDATE...
ISSUED AT 1055 AM CDT WED JUL 31 2013
WEAK SFC LOW ACROSS THE AREA LATE THIS MORNING...WITH FAIRLY
EXTENSIVE LOWER CLOUD COVER...AND CONVECTION CLOSE TO THE KY/TN
BORDER...MAINLY IN NW TN. LATEST HRRR / NSSL WRF SHOWS VERY
LITTLE CONVECTION ACROSS THE AREA TODAY. WVAPOR SHOWS A VERY
SUBTLE WAVE COMING SE FROM ERN NE AND SRN IA INTO NRN MO.
CONSIDERING THAT THE MESO MODELS DEVELOP INSTABILITY ACROSS
THE AREA TODAY...SOME WEAK SFC CONVERGENCE AS THE LOW DRIFTS
ACROSS THE AREA...AND PERHAPS WEAK UPPER SUPPORT FROM THE TAIL
END OF THE AFOREMENTIONED WAVE...WILL LEAVE AT LEAST SLIGHT
CHANCE POPS FOR CONVECTION GOING THROUGH THE DAY AND MONITOR.
BEST INSTABILITY AT 15Z IS INTO SEMO...WITH SFC LI/S DOWN TO
-4 AND CAPES APPROACHING 2000. TEMPS AND CLOUDS FORECAST WERE
GENERALLY ON TRACK...SO ONLY MINOR TWEAKS THERE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 133 AM CDT WED JUL 31 2013
GFS/NAM/RAP ALL PICK UP ON SHOWERS OVER WKY MOVING EAST WITH DRIER
AIR ALREADY STARTING TO WORK IN FROM THE WEST AND SHUT PCPN
CHANCES OFF OR AT LEAST ON A DOWNWARD TREND. WILL CONTINUE POPS
THRU EARLY TODAY...THEN WANE LATER AS UPPER TROF MAKES PASSAGE AND
SURFACE HIGH PRESSURE TRIES TO BUILD INTO MS VALLEY IN THE WAKE OF
ITS DEPARTURE...BY 00Z THU.
AFOREMENTIONED SURFACE HIGH THEN REALLY SETTLES ACROSS TN VALLEY
AND BECOMES THE WEATHER FEATURE OF NOTE FOR THE ENSUING 24-36
HOURS OR AT LEAST TIL THE NEXT SYSTEM TAKES SHAPE AND MOVES IN ON
FRIDAY. BY THEN THE HIGH HAS SHIFTED EASTWARD ACROSS THE
CUMBERLAND PLATEAU AND A WARM/SOUPY RETURN FLOW DEVELOPS IN
ADVANCE OF AN INCOMING WAVE. THIS WILL TOUCH OFF SHOWER AND STORM
CHANCES BEGINNING FRIDAY AND LASTING INTO THE WEEKEND.
WE`LL SEE TEMPS AND HUMIDITY LEVELS GRADUALLY RETURN TOWARD CLIMO
NORMS HERE IN THE NEXT 24 HOURS AND PERSIST THRU THE REMAINDER OF
THE WORKWEEK.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 245 AM CDT WED JUL 31 2013
AN UNSETTLED PATTERN IS SHAPING UP OVER THE WEEKEND INTO THE FIRST
PART OF NEXT WEEK. THE QUAD STATE REGION WILL REMAIN IN NORTHWEST
FLOW ALOFT...WITH UPPER LEVEL RIDGING OVER THE WESTERN AND SOUTHERN
U.S. AND AN UPPER LEVEL TROUGH IN THE EAST. A BAROCLINIC ZONE IS
EXPECTED TO DEVELOP OVER THE REGION ON SATURDAY AND REMAIN IN CLOSE
PROXIMITY THROUGH MONDAY. THIS WILL HELP TO INCREASE THE POTENTIAL
FOR SHOWERS AND THUNDERSTORMS OVER THE WEEKEND...ESPECIALLY SATURDAY
AS A MID LEVEL WAVE PROGRESSES ACROSS THE REGION.
MODELS ARE STILL NOT IN THE BEST AGREEMENT BY SUNDAY AND MONDAY.
SOME MODEL RUNS HAVE TENDED TO SHIFT THE FRONTAL ZONE SOUTH OF THE
AREA BY EARLY IN THE NEW WEEK. OTHERS...HOWEVER...FOCUS ADDITIONAL
ACTIVITY ALONG AND NORTH OF THE BOUNDARY AS IT RETURNS TO THE NORTH
AS A WARM FRONT LATE SUNDAY INTO MONDAY. GIVEN THE LOW CONFIDENCE
FORECAST...WILL KEEP CHANCE PROBABILITIES GOING FOR NOW.
TEMPERATURES THROUGH THE PERIOD WILL BE NEAR IF NOT A FEW DEGREES
BELOW SEASONAL NORMS. EXPECT A SMALLER THAN NORMAL DIURNAL RANGE
WITH THE ANTICIPATED SKY COVER AND PRECIPITATION CHANCES. HUMIDITY
LEVELS WILL BE QUITE HIGH AS WELL WITH DEW POINTS FORECAST IN THE
UPPER 60S TO NEAR 70.
&&
.AVIATION...
ISSUED AT 1055 AM CDT WED JUL 31 2013
WILL MONITOR CONVECTIVE CHANCES THE REST OF THE DAY. GRADUAL
IMPROVEMENT IN CLOUD BASE HEIGHTS AND VSBYS EXPECTED WITH WEAK
MIXING...HEAT OF THE DAY. LOWER CLOUDS MAY LINGER TONIGHT ACROSS
PART OF THE AREA...WITH SOME LIGHT FOG POSSIBLE AS WELL.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...NOLES
AVIATION...NOLES
AREA FORECAST DISCUSSION
NWS JACKSON KY
1130 AM EDT WED JUL 31 2013
.UPDATE...
ISSUED AT 1130 AM EDT WED JUL 31 2013
UPDATED THE FORECAST TO BETTER TIME THE PRECIPITATION INTO THE AREA
BASED ON MODEL SOUNDINGS AND CURRENT RADAR ACTIVITY...DECREASED THE
COVERAGE AND TIMING FOR THUNDERSTORMS TODAY AND TOOK THE THUNDER OUT
OF THE TONIGHT FORECAST. STILL HAVE SOME CONCERN THAT THIS SYSTEM IS
GOING TO STAY FURTHER SOUTH THAN WHAT IS CURRENTLY FORECAST. MAY
HAVE TO DECREASE THE PROBABILITY OF PRECIPITATION FOR AREAS NORTH OF
THE MOUNTAIN PARKWAY. MAKE SOME MORE ADJUSTMENTS DURING THE 2 PM
UPDATE.
UPDATE ISSUED AT 755 AM EDT WED JUL 31 2013
HOURLY TEMP AND DEWPOINTS WERE FRESHENED UP BASED ON RECENT OBS.
UPSTREAM RADAR RETURNS STILL FAVOR HIGHER POPS IN THE FAR SOUTH. NO
SUBSTANTIAL CHANGES WERE MADE AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED JUL 31 2013
A SHORTWAVE IS CURRENTLY WORKING THROUGH THE OH VALLEY REGION IN
WEST NORTHWEST FLOW...BUT IS PRODUCING ONLY LIGHT RAIN SHOWERS
LOCALLY. A RIDGE OF HIGH PRESSURE WAS CENTERED OVER THEE SOUTHERN
ROCKIES WITH AN UPPER LEVEL LOW AND TROUGH CONTINUING TO EXIT THE
NORTHEASTERN CONUS INTO THE MARITIMES. ALSO IN THE NORTHERN
STREAM...A SHORTWAVE TRACKING NEAR THE US/CANADIAN BORDER IS
APPROACHING THE UPPER MS VALLEY AND WESTERN ONTARIO. HEAVIER
PRECIPITATION THUS FAR HAS BEEN CONFINED TO SOUTHERN MIDDLE AND
EASTERN TN AND THE NORTHERN GULF COAST STATES. THERE HAS ALSO BEEN A
SLIGHT INCREASE IN CONVECTION OVER WESTERN KY.
THE SHORTWAVE NOW WORKING THROUGH THE OH VALLEY AND INTO THE
APPALACHIAN REGION AND THE SHORTWAVE WORKING TOWARD THE WESTERN GREAT
LAKES WILL EVENTUALLY BECOME A BIT MORE PHASED BY THUS AND LEAD TO A
RETURN TO A MORE AMPLIFIED EASTERN/NORTHEASTERN CONUS THROUGH AND
ROCKIES/PLAINS RIDGE. MEANWHILE A SFC LOW IS LAGGING THE UPPER LEVEL
SHORTWAVE WORKING THROUGH THE OH VALLEY. THIS LOW WILL DRIFT THROUGH
THE LOWER OH VALLEY REGION AND REACH CENTRAL KY THIS EVENING...EVENTUALLY
BECOMING DIFFUSE AND MORE OR LESS MERGING WITH A COLD FRONT ASSOCIATED
WITH THE TROUGH WORKING THROUGH ONTARIO AND THE GREAT LAKES REGION
TONIGHT AND INTO THURSDAY. THE SFC COLD FRONT SHOULD CROSS THE CWA ON
THURSDAY.
THE 0Z NAM AND THE 4Z HRR GENERALLY INDICATE REDEVELOPMENT OF
STRONGER CONVECTION THAN THE LIGHT SHOWERS CURRENTLY OVER THE CWA
TOWARD DAWN AND THEN WORK THIS INTO EASTERN KY THIS MORNING AND INTO
THIS AFTERNOON. THE NAM HAS BULLSEYE OF QPF OVER THE LAKE CUMBERLAND
REGION...BUT MUCH OF THE OTHER GUIDANCE HAS HIGHER QPF NEAR THE TN
BORDER...AND IS NOT NEARLY AS MUCH. CONFIDENCE IN THE EVOLUTION OF
THIS CONVECTION IS BELOW AVERAGE...BUT THE MODEL CONSENSUS IS THAT
BEST CHANCES SHOULD BE ACROSS THE SOUTH TODAY. THE 5Z HRRR HAS THROWN
A BIT MORE UNCERTAINTY INTO THE PICTURE...ESPECIALLY ACROSS THE NORTH
WITH IT SUGGEST COULD LARGELY REMAIN DRY.
WE HAVE OPTED TO GO VERY CLOSE TO HPC QPF WHICH LED TO LOWER AMOUNTS
THAN THE NAM OVER THE SOUTH WITH THE HIGHEST POPS OVER THE SOUTHERN
CWA. HOWEVER...THIS STILL YIELDS NEARLY AN INCH OF RAIN THROUGH
TONIGHT. ALTHOUGH A SHORTWAVE CURRENTLY WORKING THROUGH THE OH VALLEY
AND ANOTHER UPSTREAM WILL WORK ACROSS THE AREA THIS AFTERNOON AND THE
SFC LOW WILL GRADUALLY APPROACH THE AREA...CLOUD COVER SHOULD LIMIT
OVERALL INSTABILITY. THE CLOSEST LIGHTNING AT PRESENT IS OVER WESTERN
KY. THUS WE HAVE KEPT COVERAGE OF THUNDER AT ISOLATED TO SCATTERED
LEVELS THROUGH THIS EVENING WITH HIGHER COVERAGE OF SHOWERS.
HOWEVER... CHANCES FOR CONVECTION WILL LINGER THROUGH MOST OF THE
PERIOD...UNTIL LATE ON THU WHEN A COLD FRONT WILL SWEEP THE DEEPER
MOISTURE EAST AND SOUTHEAST OF THE AREA.
MOS GUIDANCE WAS TOO WARM WITH HIGHS ON TUE AND WE HAVE WENT ON THE
COLDER END OF GUIDANCE FOR MAX T TODAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 AM EDT WED JUL 31 2013
MODELS ARE AGREEING A BIT MORE HEADING INTO THE UPCOMING
WEEKEND...SO CONFIDENCE IN THE FORECAST IS INCREASING. STARTING
THURSDAY NIGHT...HIGH PRESSURE WILL BE BUILDING INTO THE
REGION...SETTING UP A DRY AND PLEASANT END TO THE WEEK. A SHORTWAVE
TROUGH WILL THEN DRAG A SURFACE WARM FRONT BACK TO THE NORTHEAST
LATE FRIDAY NIGHT INTO SATURDAY WITH ISENTROPIC ASCENT DEVELOPING
OVER THE REGION. THIS WILL YIELD THE POTENTIAL FOR A WET PERIOD ON
SATURDAY...AS THE WARM FRONT STALLS OVER THE AREA. A SECONDARY
SHORTWAVE PUSHING ACROSS THE GREAT LAKES WILL THEN DRAG A COLD FRONT
SOUTHWARD ACROSS THE OHIO RIVER VALLEY SATURDAY NIGHT INTO EARLY
SUNDAY...WITH ANOTHER PERIOD OF UNSETTLED WEATHER EXPECTED. THIS
FRONTAL BOUNDARY WILL GET SHOVED SOUTHWARD ON SUNDAY WITH DRY
WEATHER RETURNING TO FINISH OUT THE WEEKEND. HOWEVER...THE ACTIVE
WEATHER WILL CONTINUE AS ANOTHER SHORTWAVE PUSHES EAST INTO THE AREA
ON MONDAY...BRINGING ANOTHER ROUND OF SHOWERS AND PERHAPS A
THUNDERSTORM TO THE AREA. DRIER WEATHER MAY RETURN BY TUESDAY AND
WEDNESDAY...BUT GIVEN THE TROUGH OVER THE REGION...ADDITIONAL WAVES
OF UNSETTLED WEATHER COULD IMPACT THE REGION. HIGHS THROUGH THE
PERIOD WILL BE A TOUCH BELOW NORMAL WITH A GENERAL TROUGH OVER THE
EASTERN US...KEEPING TEMPERATURES UNUSUALLY COOL FOR THIS TIME OF
YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 755 AM EDT WED JUL 31 2013
UPSTREAM RADAR AND SOME OF THE MODEL GUIDANCE FAVORS CONVECTION OVER
CENTRAL KY WORKING ACROSS THE SOUTHERN PART OF THE CWA THROUGH ABOUT
18Z. THIS WOULD AFFECT LOZ AND SME AND PERHAPS AS FAR NORTH AS JKL.
THE NORTHERN PART OF THE CWA SHOULD EXPERIENCE MORE IN THE WAY OF
SCATTERED CONVECTION. A BIT OF IFR IS POSSIBLE IN ANY THUNDERSTORMS
AFTER 15Z. OTHERWISE...MVR IS EXPECTED MOST OF THE TIME THROUGH 6Z.
THE PCPN THREAT SHOULD DIMINISH LATE IN THE PERIOD AS A COLD FRONT
WORKS INTO THE AREA. SOME LOW CLOUDS NEAR THE FRONT COULD LIMIT VSBY
AND CIG TO IFR OR LOWER...AND PERHAPS BELOW AIRPORT MINS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJ
SHORT TERM...JP
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
800 AM EDT WED JUL 31 2013
.UPDATE...
ISSUED AT 755 AM EDT WED JUL 31 2013
HOURLY TEMP AND DEWPOINTS WERE FRESHENED UP BASED ON RECENT OBS.
UPSTREAM RADAR RETURNS STILL FAVOR HIGHER POPS IN THE FAR SOUTH. NO
SUBSTANTIAL CHANGES WERE MADE AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED JUL 31 2013
A SHORTWAVE IS CURRENTLY WORKING THROUGH THE OH VALLEY REGION IN
WEST NORTHWEST FLOW...BUT IS PRODUCING ONLY LIGHT RAIN SHOWERS
LOCALLY. A RIDGE OF HIGH PRESSURE WAS CENTERED OVER THEE SOUTHERN
ROCKIES WITH AN UPPER LEVEL LOW AND TROUGH CONTINUING TO EXIT THE
NORTHEASTERN CONUS INTO THE MARITIMES. ALSO IN THE NORTHERN
STREAM...A SHORTWAVE TRACKING NEAR THE US/CANADIAN BORDER IS
APPROACHING THE UPPER MS VALLEY AND WESTERN ONTARIO. HEAVIER
PRECIPITATION THUS FAR HAS BEEN CONFINED TO SOUTHERN MIDDLE AND
EASTERN TN AND THE NORTHERN GULF COAST STATES. THERE HAS ALSO BEEN A
SLIGHT INCREASE IN CONVECTION OVER WESTERN KY.
THE SHORTWAVE NOW WORKING THROUGH THE OH VALLEY AND INTO THE
APPALACHIAN REGION AND THE SHORTWAVE WORKING TOWARD THE WESTERN GREAT
LAKES WILL EVENTUALLY BECOME A BIT MORE PHASED BY THUS AND LEAD TO A
RETURN TO A MORE AMPLIFIED EASTERN/NORTHEASTERN CONUS THROUGH AND
ROCKIES/PLAINS RIDGE. MEANWHILE A SFC LOW IS LAGGING THE UPPER LEVEL
SHORTWAVE WORKING THROUGH THE OH VALLEY. THIS LOW WILL DRIFT THROUGH
THE LOWER OH VALLEY REGION AND REACH CENTRAL KY THIS EVENING...EVENTUALLY
BECOMING DIFFUSE AND MORE OR LESS MERGING WITH A COLD FRONT ASSOCIATED
WITH THE TROUGH WORKING THROUGH ONTARIO AND THE GREAT LAKES REGION
TONIGHT AND INTO THURSDAY. THE SFC COLD FRONT SHOULD CROSS THE CWA ON
THURSDAY.
THE 0Z NAM AND THE 4Z HRR GENERALLY INDICATE REDEVELOPMENT OF
STRONGER CONVECTION THAN THE LIGHT SHOWERS CURRENTLY OVER THE CWA
TOWARD DAWN AND THEN WORK THIS INTO EASTERN KY THIS MORNING AND INTO
THIS AFTERNOON. THE NAM HAS BULLSEYE OF QPF OVER THE LAKE CUMBERLAND
REGION...BUT MUCH OF THE OTHER GUIDANCE HAS HIGHER QPF NEAR THE TN
BORDER...AND IS NOT NEARLY AS MUCH. CONFIDENCE IN THE EVOLUTION OF
THIS CONVECTION IS BELOW AVERAGE...BUT THE MODEL CONSENSUS IS THAT
BEST CHANCES SHOULD BE ACROSS THE SOUTH TODAY. THE 5Z HRRR HAS THROWN
A BIT MORE UNCERTAINTY INTO THE PICTURE...ESPECIALLY ACROSS THE NORTH
WITH IT SUGGEST COULD LARGELY REMAIN DRY.
WE HAVE OPTED TO GO VERY CLOSE TO HPC QPF WHICH LED TO LOWER AMOUNTS
THAN THE NAM OVER THE SOUTH WITH THE HIGHEST POPS OVER THE SOUTHERN
CWA. HOWEVER...THIS STILL YIELDS NEARLY AN INCH OF RAIN THROUGH
TONIGHT. ALTHOUGH A SHORTWAVE CURRENTLY WORKING THROUGH THE OH VALLEY
AND ANOTHER UPSTREAM WILL WORK ACROSS THE AREA THIS AFTERNOON AND THE
SFC LOW WILL GRADUALLY APPROACH THE AREA...CLOUD COVER SHOULD LIMIT
OVERALL INSTABILITY. THE CLOSEST LIGHTNING AT PRESENT IS OVER WESTERN
KY. THUS WE HAVE KEPT COVERAGE OF THUNDER AT ISOLATED TO SCATTERED
LEVELS THROUGH THIS EVENING WITH HIGHER COVERAGE OF SHOWERS.
HOWEVER... CHANCES FOR CONVECTION WILL LINGER THROUGH MOST OF THE
PERIOD...UNTIL LATE ON THU WHEN A COLD FRONT WILL SWEEP THE DEEPER
MOISTURE EAST AND SOUTHEAST OF THE AREA.
MOS GUIDANCE WAS TOO WARM WITH HIGHS ON TUE AND WE HAVE WENT ON THE
COLDER END OF GUIDANCE FOR MAX T TODAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 AM EDT WED JUL 31 2013
MODELS ARE AGREEING A BIT MORE HEADING INTO THE UPCOMING
WEEKEND...SO CONFIDENCE IN THE FORECAST IS INCREASING. STARTING
THURSDAY NIGHT...HIGH PRESSURE WILL BE BUILDING INTO THE
REGION...SETTING UP A DRY AND PLEASANT END TO THE WEEK. A SHORTWAVE
TROUGH WILL THEN DRAG A SURFACE WARM FRONT BACK TO THE NORTHEAST
LATE FRIDAY NIGHT INTO SATURDAY WITH ISENTROPIC ASCENT DEVELOPING
OVER THE REGION. THIS WILL YIELD THE POTENTIAL FOR A WET PERIOD ON
SATURDAY...AS THE WARM FRONT STALLS OVER THE AREA. A SECONDARY
SHORTWAVE PUSHING ACROSS THE GREAT LAKES WILL THEN DRAG A COLD FRONT
SOUTHWARD ACROSS THE OHIO RIVER VALLEY SATURDAY NIGHT INTO EARLY
SUNDAY...WITH ANOTHER PERIOD OF UNSETTLED WEATHER EXPECTED. THIS
FRONTAL BOUNDARY WILL GET SHOVED SOUTHWARD ON SUNDAY WITH DRY
WEATHER RETURNING TO FINISH OUT THE WEEKEND. HOWEVER...THE ACTIVE
WEATHER WILL CONTINUE AS ANOTHER SHORTWAVE PUSHES EAST INTO THE AREA
ON MONDAY...BRINGING ANOTHER ROUND OF SHOWERS AND PERHAPS A
THUNDERSTORM TO THE AREA. DRIER WEATHER MAY RETURN BY TUESDAY AND
WEDNESDAY...BUT GIVEN THE TROUGH OVER THE REGION...ADDITIONAL WAVES
OF UNSETTLED WEATHER COULD IMPACT THE REGION. HIGHS THROUGH THE
PERIOD WILL BE A TOUCH BELOW NORMAL WITH A GENERAL TROUGH OVER THE
EASTERN US...KEEPING TEMPERATURES UNUSUALLY COOL FOR THIS TIME OF
YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 755 AM EDT WED JUL 31 2013
UPSTREAM RADAR AND SOME OF THE MODEL GUIDANCE FAVORS CONVECTION OVER
CENTRAL KY WORKING ACROSS THE SOUTHERN PART OF THE CWA THROUGH ABOUT
18Z. THIS WOULD AFFECT LOZ AND SME AND PERHAPS AS FAR NORTH AS JKL.
THE NORTHERN PART OF THE CWA SHOULD EXPERIENCE MORE IN THE WAY OF
SCATTERED CONVECTION. A BIT OF IFR IS POSSIBLE IN ANY THUNDERSTORMS
AFTER 15Z. OTHERWISE...MVR IS EXPECTED MOST OF THE TIME THROUGH 6Z.
THE PCPN THREAT SHOULD DIMINISH LATE IN THE PERIOD AS A COLD FRONT
WORKS INTO THE AREA. SOME LOW CLOUDS NEAR THE FRONT COULD LIMIT VIS
AND CIG TO IFR OR LOWER...AND PERHAPS BELOW AIRPORT MINS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...JP
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
348 AM EDT WED JUL 31 2013
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 340 AM EDT WED JUL 31 2013
A SHORTWAVE IS CURRENTLY WORKING THROUGH THE OH VALLEY REGION IN
WEST NORTHWEST FLOW...BUT IS PRODUCING ONLY LIGHT RAIN SHOWERS
LOCALLY. A RIDGE OF HIGH PRESSURE WAS CENTERED OVER THEE SOUTHERN
ROCKIES WITH AN UPPER LEVEL LOW AND TROUGH CONTINUING TO EXIT THE
NORTHEASTERN CONUS INTO THE MARITIMES. ALSO IN THE NORTHERN
STREAM...A SHORTWAVE TRACKING NEAR THE US/CANADIAN BORDER IS
APPROACHING THE UPPER MS VALLEY AND WESTERN ONTARIO. HEAVIER
PRECIPITATION THUS FAR HAS BEEN CONFINED TO SOUTHERN MIDDLE AND
EASTERN TN AND THE NORTHERN GULF COAST STATES. THERE HAS ALSO BEEN A
SLIGHT INCREASE IN CONVECTION OVER WESTERN KY.
THE SHORTWAVE NOW WORKING THROUGH THE OH VALLEY AND INTO THE
APPALACHIAN REGION AND THE SHORTWAVE WORKING TOWARD THE WESTERN GREAT
LAKES WILL EVENTUALLY BECOME A BIT MORE PHASED BY THUS AND LEAD TO A
RETURN TO A MORE AMPLIFIED EASTERN/NORTHEASTERN CONUS THROUGH AND
ROCKIES/PLAINS RIDGE. MEANWHILE A SFC LOW IS LAGGING THE UPPER LEVEL
SHORTWAVE WORKING THROUGH THE OH VALLEY. THIS LOW WILL DRIFT THROUGH
THE LOWER OH VALLEY REGION AND REACH CENTRAL KY THIS EVENING...EVENTUALLY
BECOMING DIFFUSE AND MORE OR LESS MERGING WITH A COLD FRONT ASSOCIATED
WITH THE TROUGH WORKING THROUGH ONTARIO AND THE GREAT LAKES REGION
TONIGHT AND INTO THURSDAY. THE SFC COLD FRONT SHOULD CROSS THE CWA ON
THURSDAY.
THE 0Z NAM AND THE 4Z HRR GENERALLY INDICATE REDEVELOPMENT OF
STRONGER CONVECTION THAN THE LIGHT SHOWERS CURRENTLY OVER THE CWA
TOWARD DAWN AND THEN WORK THIS INTO EASTERN KY THIS MORNING AND INTO
THIS AFTERNOON. THE NAM HAS BULLSEYE OF QPF OVER THE LAKE CUMBERLAND
REGION...BUT MUCH OF THE OTHER GUIDANCE HAS HIGHER QPF NEAR THE TN
BORDER...AND IS NOT NEARLY AS MUCH. CONFIDENCE IN THE EVOLUTION OF
THIS CONVECTION IS BELOW AVERAGE...BUT THE MODEL CONSENSUS IS THAT
BEST CHANCES SHOULD BE ACROSS THE SOUTH TODAY. THE 5Z HRRR HAS THROWN
A BIT MORE UNCERTAINTY INTO THE PICTURE...ESPECIALLY ACROSS THE NORTH
WITH IT SUGGEST COULD LARGELY REMAIN DRY.
WE HAVE OPTED TO GO VERY CLOSE TO HPC QPF WHICH LED TO LOWER AMOUNTS
THAN THE NAM OVER THE SOUTH WITH THE HIGHEST POPS OVER THE SOUTHERN
CWA. HOWEVER...THIS STILL YIELDS NEARLY AN INCH OF RAIN THROUGH
TONIGHT. ALTHOUGH A SHORTWAVE CURRENTLY WORKING THROUGH THE OH VALLEY
AND ANOTHER UPSTREAM WILL WORK ACROSS THE AREA THIS AFTERNOON AND THE
SFC LOW WILL GRADUALLY APPROACH THE AREA...CLOUD COVER SHOULD LIMIT
OVERALL INSTABILITY. THE CLOSEST LIGHTNING AT PRESENT IS OVER WESTERN
KY. THUS WE HAVE KEPT COVERAGE OF THUNDER AT ISOLATED TO SCATTERED
LEVELS THROUGH THIS EVENING WITH HIGHER COVERAGE OF SHOWERS.
HOWEVER... CHANCES FOR CONVECTION WILL LINGER THROUGH MOST OF THE
PERIOD...UNTIL LATE ON THU WHEN A COLD FRONT WILL SWEEP THE DEEPER
MOISTURE EAST AND SOUTHEAST OF THE AREA.
MOS GUIDANCE WAS TOO WARM WITH HIGHS ON TUE AND WE HAVE WENT ON THE
COLDER END OF GUIDANCE FOR MAX T TODAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 300 AM EDT WED JUL 31 2013
MODELS ARE AGREEING A BIT MORE HEADING INTO THE UPCOMING
WEEKEND...SO CONFIDENCE IN THE FORECAST IS INCREASING. STARTING
THURSDAY NIGHT...HIGH PRESSURE WILL BE BUILDING INTO THE
REGION...SETTING UP A DRY AND PLEASANT END TO THE WEEK. A SHORTWAVE
TROUGH WILL THEN DRAG A SURFACE WARM FRONT BACK TO THE NORTHEAST
LATE FRIDAY NIGHT INTO SATURDAY WITH ISENTROPIC ASCENT DEVELOPING
OVER THE REGION. THIS WILL YIELD THE POTENTIAL FOR A WET PERIOD ON
SATURDAY...AS THE WARM FRONT STALLS OVER THE AREA. A SECONDARY
SHORTWAVE PUSHING ACROSS THE GREAT LAKES WILL THEN DRAG A COLD FRONT
SOUTHWARD ACROSS THE OHIO RIVER VALLEY SATURDAY NIGHT INTO EARLY
SUNDAY...WITH ANOTHER PERIOD OF UNSETTLED WEATHER EXPECTED. THIS
FRONTAL BOUNDARY WILL GET SHOVED SOUTHWARD ON SUNDAY WITH DRY
WEATHER RETURNING TO FINISH OUT THE WEEKEND. HOWEVER...THE ACTIVE
WEATHER WILL CONTINUE AS ANOTHER SHORTWAVE PUSHES EAST INTO THE AREA
ON MONDAY...BRINGING ANOTHER ROUND OF SHOWERS AND PERHAPS A
THUNDERSTORM TO THE AREA. DRIER WEATHER MAY RETURN BY TUESDAY AND
WEDNESDAY...BUT GIVEN THE TROUGH OVER THE REGION...ADDITIONAL WAVES
OF UNSETTLED WEATHER COULD IMPACT THE REGION. HIGHS THROUGH THE
PERIOD WILL BE A TOUCH BELOW NORMAL WITH A GENERAL TROUGH OVER THE
EASTERN US...KEEPING TEMPERATURES UNUSUALLY COOL FOR THIS TIME OF
YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 210 AM EDT WED JUL 31 2013
THE AREA OF RAIN CURRENTLY OVER THE REGION HAS BEEN SO LIGHT THAT
CONDITIONS HAVE GENERALLY REMAINED VFR. IF MORE INTENSE SHOWERS
DEVELOP TO OUR WEST AFTER ABOUT 8Z AND ENTER THE CWA AROUND DAWN AND
MOVE ACROSS THE AREA ON WED...AVIATION CONDITIONS SHOULD GRADUALLY
WORSEN INTO THE MVFR RANGE FOR VIS AND OR CIGS. A BIT OF IFR
IS POSSIBLE IN ANY THUNDERSTORMS AFTER 15Z. THE PCPN THREAT SHOULD
DIMINISH LATE IN THE PERIOD AS A COLD FRONT APPROACHES THE AREA.
HOWEVER...MVFR MAY BE POSSIBLE LATE IN THE PERIOD ALONG THE FRONT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JP
LONG TERM...KAS
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
211 AM EDT WED JUL 31 2013
.UPDATE...
ISSUED AT 200 AM EDT WED JUL 31 2013
ALTHOUGH THE NAM AND HRRR GUIDANCE SUGGEST SOME ELEVATED CONVECTION
MAY OCCUR TOWARD INSTABILITY APPEARS TOO LIMITED FOR ANY THUNDER FOR
THE REMAINDER OF THE NIGHT. THE HRRR WEAKENS THIS CONVECTION MOVING
INTO THE JKL CWA DURING WED MORNING AND GENERALLY SHIFTS IT INTO TN.
OPTED TO REMOVE THUNDER FROM THE FORECAST FOR THE REST OF THE
OVERNIGHT HOURS. TEMPERATURES IN A FEW WESTERN LOCATIONS PARTICULARLY
THE CUMBERLAND VALLEY WERE RUNNING A LITTLE COOLER THAN THE PREVIOUS
FORECAST AND TEMP AND DEWPOINT GRIDS HAVE BEEN ADJUSTED ACCORDINGLY.
THE 0Z NAM QPF SEEMS A BIT TOO HIGH OVER THE SOUTH EARLY ON WED AND
UNLESS SOME THUNDERSTORMS DO DEVELOP AND TRAIN A BIT EVEN THE 22Z HPC
QPF SEEMS A BIT OVERDONE AS WELL. CONFIDENCE IN THE HIGHER VALUES IS
NOT ALL THAT HIGHS SO 12Z TO 18Z QPF FOR WED WAS TONED DOWN A BIT
FROM THE INHERITED FORECAST.
UPDATE ISSUED AT 1045 PM EDT TUE JUL 30 2013
DID A QUICK UPDATE TO THE GRIDS AND ZONES TO FINE TUNE RAIN CHANCES
THROUGH THE NIGHT AS WELL AS TO PUSH BACK ANY THUNDER CHANCES UNTIL
CLOSER TOWARDS DAWN...FOR MOST LOCATIONS. ALSO TWEAKED TEMPS AND
DEWPOINTS PER THE LATEST OBS AND TRENDS. UPDATES HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 645 PM EDT TUE JUL 30 2013
22Z SFC ANALYSIS SHOWS THAT OUR COOL HIGH PRESSURE IS NOW RETREATING
TO THE EAST IN THE FACE OF A DEVELOPING AREA OF LOW PRESSURE LIFTING
INTO THE MID MISSISSIPPI VALLEY. AHEAD OF THIS LOW...AN MCV IN THE
MID LEVELS OF THE ATMOSPHERE IS PUSHING EAST INTO KENTUCKY THIS
EVENING. THIS IS HELPING TO SUSTAIN A LARGE AREA OF LIGHT TO MODERATE
RAIN SLOWLY CROSSING THE BLUEGRASS STATE. FOR EAST KENTUCKY...SO
FAR...THIS HAS MEANT LITTLE MORE THAN SOME VIRGA OVER THE CUMBERLAND
VALLEY BUT MORE SUBSTANTIAL SHOWERS ARE NOT FAR OUT. EXPECT THE RAIN
TO OVERTAKE THE CWA THROUGH THE LATE EVENING AND EARLY MORNING HOURS
FROM WEST TO EAST. A STRAY BOLT OF LIGHTNING WILL BE POSSIBLE THROUGH
THE NIGHT ALONG WITH HEAVIER AMOUNTS OF RAIN FOR THE SOUTHEAST PARTS
OF THE AREA PER THE LATEST NAM12 AND HRRR GUIDANCE. HAVE UPDATED THE
FIRST TWO PERIODS OF THE FORECAST TO REFLECT THIS. ALSO ADJUSTED
TEMPERATURES AND DEWPOINTS THROUGH THE NIGHT IN LINE WITH THE LATEST
THOUGHTS ON PCPN CHANCES AND QPF. UPDATES HAVE BEEN SENT TO THE NDFD
AND WEB SERVERS...ALONG WITH A FRESHENED SET OF ZONES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 250 PM EDT TUE JUL 30 2013
SFC WARM FRONT FROM SRN ILL TO MIDDLE TENN AND SLOWLY CREEPING TO THE
NE. CURRENT PCPN APPEARS TO BE EDGING INTO MIDDLE KY. CURRENT CLOUD
COVER OVER ERN KY IS HIGH CI WITH SOME MID LEVEL CLOUDS AND VIRGA
EDGING INTO OUR SWRN COUNTIES. SKEW-T INDICATES A WEAK SPEED MAX AT
50H COINCIDENT WITH A VERY MOIST LAYER ABOVE AND VERY DRY BELOW THAT
MAX. SHOULD SEE A GRADUAL MOISTENING OF THE LOWER LAYERS AND A
LOWERING OF THE CEILING HEIGHTS THIS EVENING INTO TONIGHT.
MODELS INDICATE THE PCPN ENTERING THE I-75 CORRIDOR AROUND MIDNIGHT
TONIGHT AS A COLD FRONT SWEEPS ACROSS THE OHIO VALLEY OVERNIGHT. THE
COLD FRONT WILL PROVIDE THE BEST RAINFALL EARLY THU BEFORE BECOMING
NEARLY STATIONARY JUST EAST OF THE APPALACHIAN MTNS WITH SEVERAL
SHORT WAVES DROPPING FROM THE GREAT LAKES TO REINFORCE THE ERN TROF.
EACH SHORT WAVE WILL BRING ANOTHER QUICK SHOT OF PCPN BUT THE
RAINFALL ON WED NITE AND THU WILL NOT BE AS HEAVY OR WIDESPREAD WITH
THE FRONTAL BNDRY HAVING WRUNG MUCH OF THE AVAILABLE MOISTURE FROM
THE AIR. THE LAST OF THE SHRA SHOULD EASE OUT OF THE STATE ON THU
MORNING WITH THE SKY BEGINNING TO CLEAR THU AFTERNOON.
CLOUD COVER AND AN INCREASE IN DEW POINTS WILL HOLD TEMPS TONIGHT IN
THE LOWER 60S. WITH THE INFLUX OF RAIN ON WED BEFORE DROPPING TO THE
MID 60S WED NITE. THEN WITH AN END TO THE RAIN AND SOME HELP FROM
BREAKS IN THE CLOUD COVER ON THU AFTERNOON...TEMPS COULD SHOOT UP TO
THE LOWER 80S. THU HIGHS ARE PREDICATED ON SOME CLEARING...SO IF THE
CLOUDS REMAIN THE HIGHS WILL NECESSARILY NEED TO BE LOWERED SOME.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 251 PM EDT TUE JUL 30 2013
THE MODELS START OFF IN VERY GOOD AGREEMENT WITH UPPER TROUGHS OVER
BOTH COASTS AND AN UPPER RIDGE OVER THE ROCKIES. WITH THIS TYPE OF
PATTERN...SYSTEMS FROM THE WEST COAST ARE BEING BLOCKED BY THE RIDGE
FROM MOVING ACROSS THE AREA. ALL THE SYSTEMS THAT COME THROUGH THE
AREA COME FROM ARES FAR TO THE NORTH AND THEN MOVE DOWN THE BACK OF
THE UPPER TROUGH. THIS SHOULD RESULT IN CONTINUED COOL WEATHER FOR
THIS TIME OF YEAR. BY SUNDAY...THE TIMING OF THE SYSTEMS STARTS TO
BECOME LESS CERTAIN AS THE MODELS DIFFER IN THE TIMING OF THE SHORT
WAVES MOVING DOWN THE BACK SIDE OF THE TROUGH. THE GFS HAS A FRONT
MOVING THROUGH THE AREA ON SATURDAY AND HAS THE LAST OF THE
PRECIPITATION MOVING OUT OF THE AREA SUNDAY MORNING. THE 00Z ECMWF
IS A LITTLE SLOWER WITH MOVING THE RAIN OUT. THE GFS BRINGS THE NEXT
SYSTEM THROUGH ON TUESDAY WHILE THE THE 00Z ECMWF THEN DOES NOT MOVE
THE NEXT SYSTEM INTO THE AREA UNTIL WEDNESDAY. WILL STAY WITH A
MODEL BLEND FOR TIMING AND THEN NUDGE IT TOWARD THE NEW ECMWF
FORECAST WHEN IT COMES IN AT 3 PM. FOR TEMPERATURES STAYED CLOSE
STAYED A BIT COOLER THAN MOS...BUT DID NOT MAKE ANY LARGE CHANGES
FROM THE CONSENSUS MODEL BLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 210 AM EDT WED JUL 31 2013
THE AREA OF RAIN CURRENTLY OVER THE REGION HAS BEEN SO LIGHT THAT
CONDITIONS HAVE GENERALLY REMAINED VFR. IF MORE INTENSE SHOWERS
DEVELOP TO OUR WEST AFTER ABOUT 8Z AND ENTER THE CWA AROUND DAWN AND
MOVE ACROSS THE AREA ON WED...AVIATION CONDITIONS SHOULD GRADUALLY
WORSEN INTO THE MVFR RANGE FOR VIS AND OR CIGS. A BIT OF IFR
IS POSSIBLE IN ANY THUNDERSTORMS AFTER 15Z. THE PCPN THREAT SHOULD
DIMINISH LATE IN THE PERIOD AS A COLD FRONT APPROACHES THE AREA.
HOWEVER...MVFR MAY BE POSSIBLE LATE IN THE PERIOD ALONG THE FRONT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...DUSTY
LONG TERM...JJ
AVIATION...JP
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
255 PM EDT WED JUL 31 2013
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE OFF THE COAST TODAY AND A COLD
FRONT WILL APPROACH FROM THE OHIO VALLEY TONIGHT. THE COLD FRONT
WILL PASS THROUGH THE AREA LATE THURSDAY INTO THURSDAY NIGHT AND
HIGH PRESSURE WILL RETURN FOR FRIDAY. HIGH PRESSURE WILL MOVE OFF
THE COAST SATURDAY AND ANOTHER COLD FRONT WILL IMPACT THE AREA
LATE SATURDAY INTO SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE HAS MADE IT OFF THE MID ATLANTIC COAST THIS
AFTERNOON. SOUTHERLY FLOW AROUND THE HIGH HAS INCREASED ACROSS LWX
WITH PWATS SLIGHTLY INCREASING. AN UPPER LEVEL DISTURBANCE HAS
MOVED EASTWARD FROM THE OHIO VALLEY AND IS ACROSS NORTH CENTRAL
VA. ANOTHER AREA OF ENERGY IS OVER SOUTHERN WV AND SW VA. ISOLATED
SHOWERS HAVE SPREAD OVER THE HIGHLANDS...CENTRAL FOOTHILLS AND
NOVA THIS MORNING. THIS SHORTWAVE ENERGY WILL MOVE EASTWARD
THROUGH THE AFTERNOON CAUSING HEIGHTS TO FALL. ISOLATED AREAS OF
THUNDERSTORMS HAVE FORMED OUTSIDE OF LWX AND ALONG DIFFERENTIAL
HEATING BOUNDARIES INCLUDING ONE NEAR RICHMOND. CU CAN ALSO BE
SEEN ON VISIBLE ACROSS MOST AREAS ALONG THE EAST COAST AND
NORTHEAST WHERE BREAKS CAUSED THEM TO GET MORE HEATING. CLOUDS
HAVE BEEN COVERING MOST OF THE MID ATLANTIC WITH THE EXCEPTION OF
NE MD TODAY. THIS AREA IS STILL DEALING WITH SUBSIDENCE FROM
DEPARTING HIGH BUT AREA COULD SEE POP UP SHOWERS THIS AFTERNOON.
A MILD DAY OF TEMPERATURES EXPECTED AS PLACES IN THE HIGHLANDS
AND CENTRAL FOOTHILLS ARE NOT OUT OF THE 60S YET. TEMPS ARE
EXPECTED TO REACH THE UPPER 70S TO THE MID 80S EAST OF THE BLUE
RIDGE.
THERE ARE A FEW DIFFERENCES IN THE MODELS FOR LATER THIS EVENING AND
OVERNIGHT. THE 12Z NAM HAS MANY VORT MAXES MOVING UP THE EAST COAST
THIS EVENING AND OVERNIGHT WHICH WOULD ULTIMATELY LEAD TO HIGHER
CHANCE OF SHOWERS. GFS/ECMWF SHOW SHORTWAVE ENERGY MOVING OFF THE
COAST THIS EVENING WITH MOISTURE INCREASING ACROSS THE HIGHLANDS.
ELSEWHERE...LITTLE FORCING MAY PRODUCE ISOLATED SHOWERS OVERNIGHT.
HI RES MODELS SUCH AS THE WRF AND HRRR HAVE ALSO SHOWN SHOWERS
MOVING UP THE EAST COAST THIS EVENING BUT ARE CURRENTLY NOT
INTIALZING WELL. LEANED TOWARDS THE GFS/ECWMF IN FORECAST SINCE
THEY HAVE TRACKED THE LATEST SHORTWAVE AND INTIALIZED THE BEST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
COLD FRONT CROSSES THE MID ATLANTIC THURSDAY. PWATS INCREASE TO 1.8
INCHES AND SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED.
COVERAGE OF SHOWERS WILL INCREASE FROM THE HIGHLANDS THURSDAY
MORNING TO THE CHESAPEAKE BAY BY THE EVENING. SYSTEM SEEMS
PROGRESSIVE AND WPC GUIDANCE HAS AROUND AN INCH OF PRECIPITATION
EXPECTED. LOCALLY HIGHER AMOUNTS ARE POSSIBLE IN THUNDERSTORMS AS
INSTABILITY INCREASES AHEAD OF THE FROPA. CLOUD COVER WILL PLAY A
ROLE IN DAMPENING A SVR THREAT BUT FLASH FLOODING WILL BE POSSIBLE. 1-HR
FFG OVER NE MD IS LOWER THAN OTHER AREAS EAST OF THE BLUE RIDGE.
THIS AREA WILL NEED TO BE WATCHED IF THUNDERSTORMS APPROACH.
PREVIOUS DISCUSSION...
THURSDAY NIGHT...QUICK CUTOFF FROM PRECIP AS THE SFC
TROUGH MOVES EAST FROM THE CWA THURSDAY EVENING. CD FROPAS ARE
RARE FOR SUMMER... BUT CONSENSUS HAS THE TROUGH REACHING THE MID-
ATLANTIC COASTLINE THROUGH THE OVERNIGHT. MAV/MET/SREF BLEND MAKES
FOR MIN TEMPS LOW TO MID 60S INLAND...AROUND 70F FOR URBAN AND
NEARSHORE LOCALES. THE RAIN ON THURSDAY SHOULD LOWER THE WATER
TEMPS A BIT...BUT THEY ARE CURRENTLY AROUND 80F.
FRIDAY...DOWNSLOPING FLOW...SUNSHINE...AND LESS HUMIDITY LEAD TO
HIGHER TEMPS THAN RAINY THURSDAY. MID 80S MAX TEMPS...NEAR NORMAL.
DRY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
UPR TROUGH PERSISTS OVER THE ERN CONUS THROUGH THE FORECAST PERIOD.
SFC TROUGH CROSSES THE MID-ATLANTIC SATURDAY INTO SUNDAY WITH CHANCE
POPS. MORE CANADIAN HIGH PRESSURE SUNDAY AND MONDAY.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
CLOUDS HAVE THICKENED TODAY AND A FEW SHOWERS HAVE FORMED AND
DIMINISHED ACROSS THE AREA. EXPECT COVERAGE TO INCREASE THROUGH
THURSDAY AS A COLD FRONT APPROACHES FROM THE WEST.
SOUTHERLY FLOW WILL CONTINUE AHEAD OF COLD FRONT AND CLOUDS WILL
LOWER LEADING TO MVFR AND IFR CONDITIONS. VSBYS MAY BE REDUCED TO
MVFR LEVELS IN ANY PRECIPITATION...ESPECIALLY LATER THIS EVENING
AND OVERNIGHT.
HEAVY SHOWERS/THUNDERSTORMS THURSDAY AHEAD OF A WEAK COLD FRONT. IFR
CONDS LIKELY IN STRONGER ACTIVITY SLY FLOW GUSTS UP TO 20
KT...HIGHER IN THUNDERSTORMS. WLY/NWLY FLOW THURSDAY NIGHT THROUGH
FRIDAY IN VFR CONDS. SFC TROUGH SATURDAY INTO SUNDAY WITH SCATTERED
THUNDERSTORMS.
&&
.MARINE...
SOUTHERLY FLOW AROUND THE SFC HIGH WILL CONTINUE THROUGH THURSDAY.
WINDS 5-10 KNOTS EXPECTED ON THE WATERS THE REST OF THE AFTERNOON
BEFORE INCREASING AS COLD FRONT NEARS. S-SE FLOW WITH GUSTS UP TO
20 KNOTS EXPECTED OVERNIGHT. A SMALL CRAFT ADVISORY IS IN EFFECT
TONIGHT FOR THE MARYLAND CHESAPEAKE BAY SOUTH OF POOLES ISLAND AND
THE LOWER TIDAL POTOMAC RIVER.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TONIGHT AND THURSDAY AS
FROPA APPROACHES FROM THE WEST. WLY/NWLY FLOW AROUND 15 KT
THURSDAY NIGHT INTO FRIDAY. WEAK DISTURBANCE SATURDAY INTO SUNDAY
BRINGS SCATTERED THUNDERSTORMS.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES HAVE INCREASED TO AROUND A HALF FOOT ABOVE NORMAL
THIS AFTERNOON. SOUTHERLY FLOW WILL CONTINUE THROUGH MOST OF
THURSDAY AND MINOR COASTAL FLOODING WILL BE POSSIBLE NEAR
SENSITIVE LOCATIONS DURING THE HIGH TIDE CYCLE LATE TONIGHT INTO
THURSDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 PM EDT
THURSDAY FOR ANZ531>534-537-539>541-543.
SMALL CRAFT ADVISORY FROM NOON TO 6 PM EDT THURSDAY FOR ANZ530-
536-538-542.
&&
$$
SYNOPSIS...HAS
NEAR TERM...HAS
SHORT TERM...HAS/BAJ
LONG TERM...BAJ
AVIATION...BAJ/HAS
MARINE...BAJ/HAS
TIDES/COASTAL FLOODING...HAS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1012 PM EDT THU AUG 1 2013
.SYNOPSIS...
ISSUED AT 407 PM EDT THU AUG 1 2013
A SERIES OF WEAK DISTURBANCES WILL DRIFT INTO NORTHERN MICHIGAN
THROUGH FRIDAY...BRINGING LOW CHANCES OF SHOWERS AND POSSIBLY A
THUNDERSTORM. THE BEST CHANCE WILL BE IN NORTHEAST LOWER
MICHIGAN BUT MOST COMMUNITIES WILL SEE RATHER PLEASANT WEATHER.
HIGH PRESSURE WILL BUILD INTO THE WESTERN GREAT LAKES OVER THE
WEEKEND...RESULTING IN COOLER AND RAIN FREE WEATHER. THE NEXT
CHANCE FOR RAIN DOES NOT ARRIVE UNTIL NEXT WORK WEEK.
&&
.UPDATE...
ISSUED AT 1012 PM EDT THU AUG 1 2013
A SOMEWHAT UNCERTAIN NIGHTTIME FORECAST. FIRST...A RENEGADE SHRA
IS STEADILY CROSSING LAKE MI...HEADING TOWARD THE COAST BETWEEN
FRANKFORT AND EMPIRE. IT ISN/T TERRIBLY HEALTHY LOOKING...BUT HAS
HELD TOGETHER BETTER THAN ANYTHING ELSE TO THIS POINT. VERY SHORT-
TERM GRIDS CONTINUE TO BE UPDATED TO ACCOUNT FOR A FEW SHRA LATE
THIS EVENING.
THE OVERNIGHT...IN THE BIG PICTURE...FEATURES LOWERING HEIGHTS AND
STEEPENING MID-LEVEL LAPSE RATES (TO 6.25-6.5C/KM 700-500MB). WV
IMAGERY SHOWS A SHORTWAVE MOVING ESE-WARD ACROSS NORTHERN MN...AS
MOST MODELS INDICATE. WAVE WILL REACH CENTRAL TO NORTHERN LOWER MI
TOWARD MORNING. CURRENTLY...MOST OF THE SHRA/TSRA ACTIVITY IS
ALONG THE NORTHERN FLANK OF THE WAVE...OVER FAR NORTHERN MN AND
ADJOINING PORTIONS OF CANADA. AT THE LOW LEVELS...WNW-ERLY FLOW WILL
PERSIST FROM 850MB ON DOWN...PERHAPS SOME VERY SHALLOW BACKING AT
950MB TOWARD 12Z. STILL...NOTHING RESEMBLING A CLASSIC LOW LEVEL JET.
SHORT-TERM HI-REZ MODELS ARE ALL OVER THE PLACE. THE NAM BRINGS
PRECIP INTO WESTERN SECTIONS BY DAWN...THE RUC DOES THE SAME TO
NORTHERN/EASTERN SECTIONS...THE WRF-NMM TO THE SOUTH...THE LOCAL
4KM WRF TO NOBODY.
GIVEN WHERE PRECIP IS NOW IN RELATION TO WHERE THE SHORTWAVE IS
PROGGED TO GO...FAVORS THE GOING FORECAST...WHICH HAS THE HIGHEST
POPS IN EASTERN UPPER INTO SOME SECTIONS OF FAR NE LOWER (RUC-
LIKE). THAT SAID...ALSO AGREE IN KEEPING AT LEAST A SLIGHT CHANCE
IN ALL AREAS AFTER 09Z.
MINOR CHANGES AT MOST TO CLOUD COVER AND MINS.
UPDATE ISSUED AT 703 PM EDT THU AUG 1 2013
DIURNAL CONVECTION OVER NORTHERN MI SEEMS TO HAVE JUST ABOUT RUN
ITS COURSE. INSTABILITY OVER FAR SE UPPER MI...AND IN THE SAGINAW
BAY REGION...HAS BEEN JUST ABOUT USED UP. SPC MESO PAGE INDICATING
LESS THAN 500J/KG ACROSS THE ENTIRE FORECAST AREA...WITH THE
HIGHEST POCKET IN NE LOWER S OF APN. INCOMING CONVECTIVE REMNANTS
HAVE MOVED INTO NW LOWER WITHOUT REGENERATION. SHOULD BE ABLE TO
GET AWAY WITH ISOLATED POPS FOR THE COUPLE OF HOURS OR SO...AND
NOTHING THEREAFTER.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CENTERED OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WHILE A VERY PERSISTENT UPPER TROUGH
REMAINS OVER CENTRAL CANADA AND THE GREAT LAKES REGION. THIS PATTERN
WILL SWEEP A COUPLE BOUNDARIES OVER NRN MI...MAINLY FRIDAY. AN UPPER
LVL COLD POOL ASSOCIATED WITH THE 500MB TROUGH NEAR HUDSON BAY WILL
CONTINUE TO SINK INTO THE NORTHERN LAKES THROUGH FRIDAY...HELPING
KEEP TEMPS AT MID LEVELS AROUND 8C/9C WHILE 500MB TEMPS DROP TO
-18C. THIS VERTICAL TEMPERATURE PROFILE WILL STEEPEN MID LEVEL
LAPSE RATES TO NEARLY 6C/KM TONIGHT INTO FRIDAY EVENING. EXPECT
CONVECTION THIS AFTERNOON WILL DIMINISH THIS EVENING WITH LACK OF
SOLAR RADIATION AND PRESENCE OF ANY BOUNDARY...THOUGH BECOME MORE
WIDESPREAD FRIDAY AFTERNOON ONCE AGAIN IN ADVANCE OF APPROACHING
SURFACE AND UPPER LEVEL FEATURES. MODEL SOUNDINGS SHOWING THE BEST
CONVERGENCE ASSOCIATED WITH APPROACHING BOUNDARIES FRIDAY...TO
FINALLY EXIT EAST INTO LAKE HURON AFTER 18Z FRIDAY.
OVERALL WILL KEEP SMALL CHC`S OF SHOWERS AND THUNDERSTORMS ACROSS
THE CWA TONIGHT AND FRIDAY. WILL MENTION HIGH TEMPS FRIDAY SIMILAR
TO THURSDAY TEMP VALUES...IN THE LOWER 70S...AS UPPER TROUGH AND
850/500MB TEMPS REMAIN THE SAME.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
OVERVIEW: 4-WAVE LONGWAVE PATTERN IN PLACE ACROSS THE NORTHERN
HEMISPHERE TO START THIS FORECAST PERIOD...ONE LONG WAVE TROUGH AXIS
BISECTED THE MIDWEST (AROUND 90W) AND BOUNDED BY RIDGING ALONG EACH
COAST. THIS PATTERN IS FORECAST TO CHANGE VERY LITTLE THROUGH THE
EXTENDED FORECAST...ALTHOUGH WITH SLOW EASTWARD MIGRATION OF THE
LONGWAVE TROUGH INTO THE GREAT LAKES/NEW ENGLAND AND SHARP
RIDGING/VERY WARM TEMPS IN THE WEST. THIS KEEPS OVERALL COOL/BELOW
NORMAL TEMPS INTACT FOR THE REGION THROUGH NEXT WEEK.
WEATHER-WISE THROUGH SUNDAY...WE START OUT ON THE UNSETTLED SIDE OF
THINGS FOR THE END OF THE WORK WEEK AS A COUPLE SHORT WAVES DIP
THROUGH THE GREAT LAKES REGION. HOWEVER...DEVELOPING NW FLOW ALOFT
FRIDAY NIGHT AND HEADING INTO THE WEEKEND LEADS TO A LARGE EXPANSE
OF HIGH PRESSURE BUILDING ACROSS THE NRN PLAINS THROUGH THE GREAT
LAKES. THIS WILL SET THE STAGE FOR QUIET WEATHER FOR THIS UPCOMING
WEEKEND...ALBEIT CONTINUED COOL-ISH WITH DAYTIME TEMPS RUNNING
AROUND 10 DEGREES BELOW NORMAL.
MONDAY THROUGH THURSDAY...QUIET WEATHER TO START NEXT WORK WEEK WITH
HIGH PRESSURE/NORTHWEST FLOW ALOFT AND COOLER TEMPS STILL SETTLED
OVER THE REGION. THEN...TUESDAY THROUGH THURSDAY BECOMES A BIT MORE
NEBULOUS AS STRONGER SHORT WAVE AND ASSOCIATED CLOSED LOW DROP OUT
OF CENTRAL CANADA DOWN INTO THE MIDWEST/GREAT LAKES. MODEL
TIMING/RUN-TO-RUN DIFFERENCES REGARDING THE PATTERN EVOLUTION ADD TO
THE UNCERTAINTY AS THE ECMWF TURNS DOWNRIGHT COOL ONCE AGAIN BY LATE
NEXT WEEK WITH ANOTHER CLOSED LOW/POCKET OF COOL AIR DESCENDING OVER
THE GREAT LAKES (BY COMPARISON...GFS IS MORE PROGRESSIVE AND
WARMER). WILL HAVE CHANCY POPS AND BELOW NORMAL TEMPS THROUGH THE
TUESDAY-THURSDAY TIMEFRAME GIVEN THE PROXIMITY TO THE TIGHTER
BAROCLINIC ZONE... ALTHOUGH A FAIR AMOUNT OF UNCERTAINTY SURROUNDS
THIS TIMEFRAME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 729 PM EDT THU AUG 1 2013
MAINLY VFR...THOUGH PRECIP COULD PRODUCE BRIEF RESTRICTIONS VERY
LATE TONIGHT INTO FRIDAY.
LOW PRESSURE ON HUDSON BAY CONTINUES TO PUSH OCCASIONAL COLD
FRONTS ACROSS NORTHERN MI. THE NEXT WILL MOVE ACROSS THE AREA AT
MIDDAY FRIDAY. SHRA ARE EXPECTED TO DEVELOP AHEAD OF
THIS...PERHAPS ARRIVING IN NW LOWER MI TOWARD DAWN. THESE ARE NOT
A SURE BET...AND ALL TAF SITES HAVE JUST A VCSH MENTION IN THEM.
THAT DOES NOT PRECLUDE BRIEF CIG/VSBY RESTRICTIONS.
LIGHT WINDS TONIGHT...STARTING OUT FROM THE SW FRIDAY MORNING THEN
VEERING NW IN THE AFTERNOON (BECOMING NE OFF THE LAKE AT APN).
&&
.MARINE...
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CURRENTLY OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WITH A COUPLE OF WEAK BOUNDARIES
SWEEPING OVER THE GREAT LAKES THROUGH FRIDAY. EXPECT WINDS AND
WAVES TO REMAIN BELOW SCA CRITERIA THRU THE PERIOD...WITH WESTERLY
WINDS TONIGHT TRENDING NORTHWEST BY FRIDAY. &&
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JZ
SYNOPSIS...NS
SHORT TERM...SR
LONG TERM...BA
AVIATION...JZ
MARINE...SR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
917 PM EDT THU AUG 1 2013
.UPDATE...
ISSUED AT 910 PM EDT THU AUG 1 2013
SHOWERS AND ISOLATED THUNDERSTORMS HAVE MOVED INTO WESTERN LAKE
SUPERIOR AHEAD OF THE UPPER SHORT WAVE OVER NW MN. THE SUSPICION IS
THAT MANY OF THESE ARE DIURNALLY DRIVEN AS THE INTENSITY OF THEM
OVER MN HAVE SEEMED TO DIMINISH OVER THE LAST HOUR OR TWO.
HOWEVER...THE COMBINATION OF THE UPPER DISTURBANCE MOVING OVER LAKE
SUPERIOR TONIGHT...AND MUCH OF THE AREA BEING UNDER THE LEFT EXIT
REGION OF THE UPPER JET WOULD SUGGEST AT SOME SCATTERED SHOWERS
MOVING ACROSS THE AREA OVERNIGHT...ESPECIALLY ACROSS LAKE SUPERIOR
AND THE KEWEENAW PENINSULA. AS SUCH...HAVE INTRODUCED SCATTERED
SHOWERS INTO THE FORECAST IN THOSE AREAS....AND ISOLATED SHOWERS
ACROSS THE REMAINDER OF THE AREA. THIS IS SIMILAR TO WHAT THE THE
LOCAL RAPID UPDATE WRF MODEL AND HRRR SUGGEST. WILL ALSO MAINTAIN A
SMALL CHANCE FOR THUNDER OVERNIGHT AS 850-500MB LAPSE RATES STEEPEN
TO NEARLY 7 C/KM AS THE UPPER WAVE MOVES OVERHEAD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 409 PM EDT THU AUG 1 2013
SMALL CHANCES OF SHOWERS WILL CONTINUE THROUGH FRIDAY AS THE REGION
REMAINS UNDER THE INFLUENCE OF MULTIPLE WEAK SHORTWAVES DIGGING
SOUTHEAST ON THE BACKSIDE OF A BROAD MID-LEVEL LOW OVER NORTHERN
ONTARIO.
TONIGHT...ONGOING SHOWERS ACROSS THE INTERIOR EAST HALF ON THE FIRST
SHORTWAVE WILL DIMINISH WITH THE LOSS OF DAYTIME HEATING THIS
EVENING. THE SECOND SHORTWAVE IN THE WEAK WAVE-TRAIN WILL PASS OVER
THE CWA OVERNIGHT...AND ONCE AGAIN BRING A SLIGHT CHANCE OF SHOWERS.
THIS WAVE IS CURRENTLY CROSSING LAKE WINNIPEG...AND IS EXPECTED TO
ARRIVE ACROSS THE WESTERN CWA AFTER MIDNIGHT. WATER VAPOR IMAGERY
GIVES THE SHORTWAVE A RATHER BENIGN LOOK AS CLOUD COVER HAS
DIMINISHED SIGNIFICANTLY OVER THE PAST DAY. IT APPEARS THAT THE WAVE
HAS BECOME SOMEWHAT SHEARED OUT OVER NORTHERN SASKATCHEWAN.
UPPER-LEVEL JET SUPPORT WILL BE MARGINAL...WITH UPPER MI SITUATED
BETWEEN THE LEFT-EXIT AND ENTRANCE REGIONS OF THE JET.
NONETHELESS...SHOWERS AND A FEW STORMS HAVE DEVELOPED OVER SOUTHWEST
ONTARIO THIS AFTERNOON AND HIGH-RES MODELS CONTINUE TO BRING SHOWERS
INTO THE WEST HALF IN THE EVENING. HAVE THEREFORE KEPT POPS IN THE
FORECAST...BUT LIMITED THEM TO LOW-END SLIGHT CHANCES FOLLOWING THE
WINDOW OF BEST FORCING FROM WEST TO EAST ACROSS THE CWA. HAVE ALSO
LEFT POPS HIGHER OVER THE EAST TOWARD 12Z FRIDAY AS THE INFLUENCE OF
THE INCOMING LAST SHORTWAVE...MENTIONED BELOW...PROVIDES SOME
ASSISTANCE TO THE DEPARTING WAVE.
FRIDAY...THE FINAL SHORTWAVE IS EXPECTED TO BE A BIT MORE POTENT
THAN THE PREVIOUS TWO...AND WILL BE TRACKING SOUTHEAST ACROSS THE
ARROWHEAD OF MN TO JUST WEST OF THUNDER BAY BY 12Z FRIDAY. MODEL
TRENDS HAVE BEEN FAIRLY CONSISTENT...THOUGH THE NAM HAS TRENDED
TOWARD A SLIGHT STRONGER TROUGH OVER THE PAST FEW RUNS. MOISTURE
AVAILABILITY WILL BE LOW...WITH LESS THAN 10 PERCENT RH THROUGH MUCH
OF THE LAYER ABOVE 700 MB ACROSS THE WEST HALF. THE BEST CHANCE OF
SEEING ANY PRECIP STILL LOOKS TO BE ACROSS THE INTERIOR EAST HALF IN
THE AFTERNOON AS HEATING AND LAKE BREEZE CONVERGENCE ASSIST WITH
LIFT FROM THE SHORTWAVE. MID-LEVEL MOISTURE WILL ALSO A BIT
HIGHER...THOUGH STILL RATHER DRY...ACROSS THE EAST HALF. SAW NO
REASON TO CHANGE THE GOING FORECAST OTHER THAN TO MAKE SOME TWEAKS
IN TIMING AND PLACEMENT IN THE MESOSCALE. THAT INCLUDED EXPANDING
POPS WESTWARD TO THE INTERIOR CENTRAL DURING PEAK HEATING GIVEN
TODAYS TRENDS OF A FEW LIGHT SHOWERS DEVELOPING ALBEIT POOR
MOISTURE. AS FOR THUNDER POTENTIAL...MLCAPE IS PROGGED TO BE A
MEAGER 500 J/KG WITH NORMALIZED CAPE LESS THAN 0.1. THIS WOULD GIVE
POTENTIAL FOR AT LEAST SOME ISOLATED LIGHTNING IN ANY OF THE
STRONGER SHOWERS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 409 PM EDT THU AUG 1 2013
TROUGH OVER THE EASTERN HALF OF CANADA AND NE U.S./GREAT LAKES
REGION STAYS IN PLACE THROUGH MOST OF THE EXTENDED PERIOD OF THE
FCST DUE TO PERSISTENT REX BLOCK OVER NW CANADA AND THE PAC NW COAST
AND MEAN RDGG OVER THE NORTH ATLANTIC. AS A RESULT OF THIS PATTERN
...TEMPS SHOULD REMAIN AT OR BELOW NORMAL THROUGH THE PERIOD. A
SERIES OF NW FLOW SHORTWAVES ROTATING ON THE SRN/WRN PERIPHERY OF
THE ERN CANADIAN TROUGH WILL BRING PERIODIC SHRA TO WEST AND CENTRAL
UPPER MI MAINLY FOR EARLY TO MID NEXT WEEK.
SAT-SUN...THE WEEKEND LOOKS DRY WITH LOW-LEVEL FLOW BECOMING
INCREASINGLY ANTICYCLONIC AS SFC-H85 HIGH PRESSURE EXPANDS FROM
CENTRAL CANADA ACROSS MUCH OF THE GREAT LAKES REGION. 5H COLD POOL
SLIDES EAST...TAKING STEEPER MID-LVL LAPSE RATES WITH IT...SO NOT
EXPECTING ANY DIURNAL AFTERNOON SHRA. TEMPS SATURDAY WILL BE ON THE
COOLER SIDE OF NORMAL ESPECIALLY NEAR LK SUPERIOR WHERE 60S READINGS
ARE EXPECTED WITH ONSHORE NW WINDS. WARMEST TEMPS WILL BE FAR SOUTH
CENTRAL AWAY FROM THE COOLING INFLUENCE OF LAKE SUPERIOR...EXPECT
READINGS THERE IN THE LOWER TO MID 70S. TEMPS ON SUNDAY SHOULD REACH
THE 70S OVER MUCH OF THE AREA...EXCEPT LOCALLY COOLER 60S READINGS
NEAR THE GREAT LAKES SHORELINES.
MON-TUE...MODELS INDICATE RETURN SW FLOW OF HIGHER SFC DEW POINTS
INTO THE AREA FOR MONDAY INTO TUESDAY AS SFC RDG AXIS SLIDES TO THE
EAST. THE INCREASED MOISTURE ALONG WITH PERIODIC SHORTWAVES AND THE
APPROACH OF A FRONTAL BOUNDARY FM THE NW WILL WARRANT CARRYING SOME
LOW CHC POPS FOR SHRA/ISOLD TSRA MAINLY CENTRAL AND EAST WHERE
INSTABILITY WILL BE GREATEST AND LOW-LVL CONVERGENCE WILL BE AIDED
BY LAKE BREEZES.
WED-THU...THE 12Z ECMWF IS STILL THE SLOWEST MOVING THROUGH INITIAL
COLD FRONT AND HAS IT POSITIONED OVER THE SCNTRL AND ERN CWA AT 12Z
WED. THUS...WILL NEED TO MAINTAIN LOW CHC POPS FOR SHRA OVER THESE
AREAS ON WED. ECMWF CONTINUES TO MAINTAIN DEEPER CLOSED LOW OVER THE
UPPER GREAT LAKES ON THU AND THE 12Z RUN SHOWS A STRONG SHORTWAVE
MOVING THROUGH THE AREA THU AFTERNOON WHILE DEVELOPING AFTERNOON
SHRA OVER THE CENTRAL AND ERN FCST AREA. THE ECMWF IS THE ONLY ONE
OF THE 12Z MODELS TO SHOW THIS STRONG SHORTWAVE/CLOSED LOW ROTATING
THROUGH THE AREA. SO FOR NOW GIVEN MODEL UNCERTAINTY WILL ONLY HAVE
SLIGHT CHC POPS FOR SHRA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 745 PM EDT THU AUG 1 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. A WEAK UPPER IMPULSE
MAY BRING ISOLATED SHOWERS TO OR NEAR THE TERMINALS LATER THIS
EVENING INTO THE OVERNIGHT PERIOD...BUT EVEN IF IT DOES THEY WILL BE
SHORT LIVED AND MAY BRING CIGS BRIEFLY TO MVFR...NOT ENOUGH
CONFIDENCE TO INCLUDE IN ANY FCST. ONCE THIS DISTURBANCE MOVES
THROUGH...FRI SHOULD BE A FAIRLY QUIET DAY. LAKE BREEZE SHOWERS AND
ISOLATED STORMS WILL DEVELOP ACROSS THE EASTERN HALF OF UPPER
MICHIGAN IN THE AFTERNOON...BUT SHOULD STAY OUT OF THE TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT THU AUG 1 2013
QUIET WEATHER WILL CONTINUE ACROSS LAKE SUPERIOR THROUGH THE
PERIOD...WITH WINDS REMAINING UNDER 20 KNOTS. A SERIES OF WEAK
TROUGHS WILL CROSS THE LAKE THROUGH FRIDAY AFTERNOON AND BRING SMALL
CHANCES OF SHOWERS. HIGH PRESSURE WILL THEN TAKE HOLD OF THE UPPER
GREAT LAKES FOR THE WEEKEND. ANOTHER TROUGH WILL TRACK SOUTHEAST
FROM NORTHERN ONTARIO INTO THE UPPER GREAT LAKES MONDAY NIGHT INTO
TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MRD
SHORT TERM...KLUBER
LONG TERM...VOSS
AVIATION...MRD
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
312 PM EDT WED JUL 31 2013
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE
.SYNOPSIS...
ISSUED AT 311 PM EDT WED JUL 31 2013
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THIS EVENING AS
A WEAK COLD FRONT PASSES THROUGH. CONDITIONS DRY OUT ON THURSDAY
BEFORE RAIN CHANCES RETURN FRIDAY MORNING WITH A WEAK UPPER AIR
WAVE. TEMPERATURES WILL REMAIN A LITTLE COOL WITH HIGHS IN THE
MID TO UPPER 70S THROUGH THE WEEKEND.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 311 PM EDT WED JUL 31 2013
EXPECT SHOWERS AND ANY POSSIBLE THUNDERSTORMS TO END BY THIS
EVENING WITH ONLY A SLIGHT CHANCE FOR SHOWERS AND STORMS TO THE
EAST TOMORROW AFTERNOON. SOLID CHANCE FOR RAIN RETURNS FRIDAY
MORNING WITH THE NEXT SHORTWAVE ROTATING THROUGH THE NORTHWEST
FLOW.
WE COULD CERTAINLY SEE SOME STORMS IMPACT SOUTHWEST LOWER MICHIGAN
AS THEY MOVE IN FROM WISCONSIN. STORMS ARE CURRENTLY DEVELOPING IN
CENTRAL WISCONSIN ALONG THE COLD FRONT. NOT OVERLY IMPRESSED...THE
BEST CHANCE FOR THUNDERSTORMS IS CERTAIN TO THE NORTHEAST. CLOUD
COVER HAS LIMITED INSTABILITY AND THE UPPER AIR DIVERGENCE IS MORE
FAVORABLE IN NORTHER LOWER MICHIGAN. THE HRRR SUGGESTS A WEAKENING
BAND OF SHOWERS WILL ENTER WEST MICHIGAN EARLY THIS EVENING...SO
WE BUMPED UP POPS SLIGHTLY.
AREAS OF FOG ARE LIKELY OVERNIGHT WITH THE RAIN COMING TO AN END BY
MIDNIGHT OR SO AND DRIER AIR FILTERING IN BEHIND THE FRONT. CLOUDS
DURING THE DAY HAVE LIMITED HIGH TEMPS AND CLOUDS CLEARING
OVERNIGHT AS WELL AS LIGHT WINDS ALL SUGGEST FAVORABLE CONDITIONS
FOR FOG DEVELOPMENT.
DUE TO THE POSITIONING OF THE UPPER LEVEL JET AND LIMITED
INSTABILITY...WE FEEL THE BEST AREA FOR SHOWERS AND STORMS ON
THURSDAY AFTERNOON IS EASTERN LWR MICHIGAN. THE UPPER JET FLOWS
DIRECTLY OVER US ON FRIDAY BRINGING THE POTENTIAL FOR ADDITIONAL
SHOWERS...HOWEVER THE ENTRANCE AND EXIT REGION DYNAMICS PASS TO
THE NORTHEAST AND SOUTHWEST. THE HEAVIER QPF AMOUNTS ARE RESERVED
TO THESE AREAS FOR THESE REASONS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 311 PM EDT WED JUL 31 2013
SEASONABLY COOL TEMPERATURES ARE EXPECTED THROUGH THE LONG RANGE
FORECAST PERIOD WITH A PERSISTENT UPPER LEVEL TROUGH IN PLACE OVER
THE NORTHERN GREAT LAKES REGION THAT WILL AMPLIFY OVER OUR REGION
TOWARD THE MIDDLE PORTION OF NEXT WEEK.
A HIGH PRESSURE RIDGE SHOULD BRING FAIR AND DRY BUT SEASONABLY COOL
WEATHER SATURDAY THROUGH SUNDAY. THE FORECAST FOR THE EARLY TO
MIDDLE PORTION OF NEXT WEEK BECOMES A LITTLE MORE UNCERTAIN SINCE THE
UPPER LEVEL TROUGH WILL AMPLIFY OVER THE NORTHERN GREAT LAKES REGION
AND SEVERAL SHORTWAVES WILL DROP DOWN FROM THE NW. THIS TYPE OF
PATTERN COULD BRING SOME SCATTERED SHOWERS AND A FEW STORMS MONDAY
THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1230 PM EDT WED JUL 31 2013
VARIABLE CONDITIONS WILL CONTINUE THIS AFTERNOON RANGING MAINLY FROM
MVFR TO IFR DUE TO LOW CIGS AND SCATTERED SHOWERS. WE CANNOT
COMPLETELY RULE OUT DEVELOPMENT OF AN ISOLATED STORM LATE THIS
AFTERNOON BUT THE BETTER CHANCE FOR STORMS WILL STAY EAST OF ALL OUR
TERMINALS OVER EASTERN LOWER MICHIGAN INTO ONTARIO CANADA THIS
EVENING.
A FEW SCATTERED SHOWERS WILL LINGER INTO THIS EVENING BEFORE THE
SHOWERS END AND CONDITIONS WILL GRADUALLY IMPROVE FROM MVFR/IFR TO
VFR OVERNIGHT THROUGH 18Z THURSDAY. THERE IS A SMALL CHANCE OF
PATCHY FOG DURING THE EARLY MORNING HOURS THURSDAY PARTICULARLY IF
SKIES TRY TO CLEAR OVERNIGHT... BUT THERE IS NOT ENOUGH POTENTIAL IN
IT TO WARRANT INCLUSION IN THE TERMINAL FCSTS AT THIS TIME.
&&
.MARINE...
ISSUED AT 311 PM EDT WED JUL 31 2013
WINDS WILL PICK UP ON THURSDAY BEHIND THE COLD FRONT OUT OF THE
NORTHWEST. WINDS WILL BE IN THE 10 TO 15 KT RANGE...KEEPING WINDS
AND WAVES BELOW SMALL CRAFT ADVISORY CRITERIA.
&&
.HYDROLOGY...
ISSUED AT 311 PM EDT WED JUL 31 2013
LIMITED QPF WILL RESULT IN FEW HYDRO CONCERNS THROUGH THE WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...EBW
SHORT TERM...WDM/EBW
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...WDM/EBW
MARINE...WDM/EBW
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
138 AM EDT WED JUL 31 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 314 PM EDT TUE JUL 30 2013
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WNW FLOW ALF
OVER THE NRN TIER CONUS AND OVER THE UPR LKS BTWN A SPRAWLING RDG
OVER THE S AND A TROF OVER CNTRL CANADA. SOME SCT -SHRA ASSOCIATED
WITH A DISTURBANCE THRU ONTARIO JUST N OF LK SUP IMPACTED UPR MI
EARLIER IN THE DAY...BUT THE ARRIVAL OF MUCH DRIER AIR ALF SHOWN
BEST ON THE 12Z MPX...ABERDEEN SDAKOTA...AND BISMARCK RAOBS IS
CAUSING THE SHRA TO DIMINISH THIS AFTN. STRONG CAPPING DEPICTED ON
THE LOCAL AND THOSE UPSTREAM RAOBS HAS PREVENTED ANY TS. THE CLDS
ARE A BIT MORE RESILIENT ESPECIALLY OVER THE W WITH LINGERING LLVL
MSTR SHOWN ON THOSE UPSTREAM RAOBS. FARTHER TO THE W...ANOTHER
SHRTWV MOVING FM THE NRN ROCKIES INTO THE NRN PLAINS IS INTERACTING
WITH THE MUCH MOISTER ENVIRONMENT SHOWN ON THE 12Z GLASGOW MT RAOB
AND CAUSING MORE SHRA/TS TO EXPAND INTO THE NRN PLAINS.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS/IMPACT ON TEMPS
TNGT AND THEN SHRA/TS CHCS LATE TNGT THRU WED ASSOCIATED WITH
DISTURBANCE NOW ROLLING INTO THE NRN PLAINS.
TNGT...WITH DRYING ALF AND LOSS OF DAYTIME HEATING...ANY LINGERING
DIURNAL -SHRA SHOULD DIMINISH ANRD 00Z...WITH THE MORE PERSISTENT
ACTIVITY ALONG DECAYING LK BREEZE BNDRY OVER THE NCENTRAL. SUPRISED
SEVERAL OF THE MODELS GENERATE PCPN THRU MUCH OF THE NGT. BUT
CONSIDERING THE MAGNITUDE OF THE DRYING SHOWN ON THE UPSTREAM RAOBS
AND LACK OF ANY SGNFT H85 THETA E ADVCTN...SUSPECT THE REST OF THE
EVNG WL FEATURE DRY WX WITH THIS MID LVL DRY AIR DOMINATING. MORE
SHRA MAY ARRIVE OVER THE W LATER TNGT AS DPVA/HGT FALLS IN ADVANCE
OF NEXT SHRTWV PUSH INTO THE AREA AND ERODE MID LVL CAPPING AND
MOISTEN THE MID LVLS. BUMPED UP POPS OVER THE W TO ACCOUNT FOR MODEL
TRENDS TOWARD FASTER ARRIVAL OF THIS DYNAMIC FORCING.
WED...SHRA/EMBEDDED TS OVER THE W IN THE MRNG IN ADVANCE OF INCOMING
SHRTWV/ATTENDANT COLD FNT WL MOVE E THRU THE DAY WITH FAIRLY POTENT
DPVA/DEEP LYR QVECTOR CNVGC. A GOOD AMOUNT OF CLD COVER/FCST NEUTRAL
TO NEGATIVE H85 THETA E ADVCTN WL LIMIT HOW MUCH DEEPER LAPSE RATES
CAN DESTABILIZE...AND MODEL FCST SDNGS SHOW NARROW/SKINNY CAPE
DESPITE MUCAPE AS HI AS 1000J/KG. SO SUSPECT SEVERE WX THREAT WL BE
QUITE LIMITED DESPITE STRENGTH OF SHRTWV/12HR HGT FALLS UP TO 60M
DURING DIURNAL HEATING TIME/DEEP LYR SHEAR 30-35KTS...ESPECIALLY
SINCE MODELS HAVE TRENDED FASTER WITH THE SHRTWV PASSAGE/COLD FROPA.
THE BETTER CHC FOR MORE WDSPRD AND STRONGER SHRA/TS WOULD BE OVER
THE E...WHERE LATER ARRIVAL OF THE FNT MIGHT ALLOW FOR MORE DIURNAL
ENHANCEMENT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 241 PM EDT TUE JUL 30 2013
MUCH OF THIS TIME PERIOD WILL BE PLAGUED BY AFTERNOON SHOWERS OR
POSSIBLE THUNDERSTORMS ACROSS MAINLY CENTRAL UPPER MICHIGAN...THANKS
TO PERSISTENT NW FLOW ALOFT USHERING IN NEARLY DAILY DISTURBANCES
THAT WILL BE ENHANCED BY DAYTIME HEATING AND POTENTIAL LAKE BREEZES.
EXPECT A NEARLY STEADY FORECAST OF THROUGH TUESDAY OF LOWS IN THE
50S /WITH A FEW UPPER 40S/ AND HIGHS IN THE 60S TO LOW 70S /WARMEST
SOUTH CENTRAL/.
BY WEDNESDAY EVENING THE MAIN SYSTEM WILL BE ON ITS WAY OUT...WITH
THE 500MB LOW SET UP ACROSS NORTHERN ONTARIO AND A BROAD TROUGH
EXTENDING FROM ALBERTA AND SASKATCHEWAN THROUGH WI AND MI. THE SLOW
MOVING SFC LOW SHOULD BE OVER N ONTARIO...WITH A COLD FRONT
EXTENDING ACROSS E UPPER MI. BEHIND THE FRONT...LIGHT W TO WNW FLOW
WILL BE THE RULE NEAR THE SFC...WITH THE SFC TROUGH SLOWLY EXITING
EASTWARD BY THE END OF THE WORK WEEK. A SECONDARY COLD FRONT/TROUGH
WILL CROSS THE REGION LATE THURSDAY AFTERNOON...WITH ANOTHER GOOD
CHANCE OF SHOWERS OR THUNDERSTORMS MAINLY INLAND FROM LAKE SUPERIOR.
HIGH PRESSURE WILL ENCOMPASS UPPER MI AND LAKE SUPERIOR LATE FRIDAY
THROUGH SUNDAY. THE GFS AND ECMWF ARE IN A SLIGHT DISAGREEMENT BY
SUNDAY NIGHT...WHICH CONTINUES THROUGH THE REMAINDER OF THE FCST
PERIOD. IT ALL STEMS FROM TIMING OF THE NEXT WAVES SWINGING IN FROM
THE NW...WITH THE GFS BUILDING IN A MORE ROBUST RIDGE AT THE SFC AND
ALOFT SUNDAY NIGHT. EXPECT WAA TO BEGIN OVER THE W LATE
SUNDAY...WITH HIGH CLOUDS ENCROACHING IN ADVANCE OF LOW PRESSURE
ORGANIZING ACROSS THE PLAINS STATES. WE MAY END UP DRY ON
MONDAY...AS THE 30/00Z IS MUCH WEAKER AND SLOWER WITH THE LOW WHEN
COMPARED TO THE 30/12Z GFS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 138 AM EDT WED JUL 31 2013
VFR CONDITIONS SHOULD PREVAIL THRU THE NIGHT AT KIWD/KCMX/KSAW.
HOWEVER...THERE IS A SMALL POTENTIAL FOR FOG OR LOWER CLOUDS TO
DEVELOP AS CURRENT STRATOCU DECK BREAKS UP SOME. WILL BE SOMETHING
TO MONITOR. WHILE THE NIGHTTIME HRS SHOULD BE DRY...THERE MAY BE A
FEW -SHRA/SPRINKLES AROUND THE AREA...PARTICULARLY IN CNTRL UPPER
MI. COVERAGE SHOULD BE TOO LOW TO INCLUDE MENTION IN FCST. BETTER
OPPORTUNITY FOR SHRA WILL ARRIVE THIS MORNING INTO THE AFTN AS COLD
FRONT SWINGS THRU THE UPPER LAKES. ANY HEAVIER SHRA COULD BRING MVFR
CONDITIONS. THERE MAY BE A FEW TSRA AS WELL...ESPECIALLY ACROSS
CNTRL UPPER MI...BUT TSRA WILL DEPEND ON AMOUNT OF DAYTIME HEATING
TO GENERATE INSTABILITY. FOR NOW...ONLY INCLUDED VCSH AT KCMX/KIWD
DUE TO BETTER INSTABILITY DEVELOPING S AND E OF THOSE TERMINALS.
OPTED TO INCLUDE VCTS AT KSAW WITH FRONT ARRIVAL COINCIDING WITH
DAYTIME HEATING. PCPN CHC WILL END NW TO SE DURING THE AFTN WITH VFR
CONDITIONS INTO THE EVENING HRS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 314 PM EDT TUE JUL 30 2013
EXPECT WINDS NO HIGHER THAN 20 KTS THIS FORECAST PERIOD WITH A WEAK
PRESSURE GRADIENT DOMINATING THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
1252 PM CDT WED JUL 31 2013
.AVIATION...
COLD AIR ALOFT HAS RESULTED IN SCATTERED CU DEVELOPMENT AROUND 3-4
KFT ACROSS THE NORTHLAND. VERY ISOLATED SHOWERS AND A POSSIBLE
THUNDERSTORM WILL BE FOUND THIS AFTERNOON...MAINLY OVER THE
MINNESOTA ARROWHEAD AND NORTHERN WISCONSIN. HAVE KEPT VCSH AT KHIB
AND KHYR THROUGH 00Z. THE STEEP LAPSE RATES HAVE ALSO ALLOWED FOR
DEEP MIXING AND GUSTY WEST-NORTHWEST WINDS. EXPECT FREQUENT GUSTS
OF 20-25 KT THROUGH THE EARLY EVENING. WINDS WILL DIMINISH QUICKLY
AROUND SUNSET. SIMILAR CONDITIONS WITH ISOLATED SHOWERS AND GUSTY
NORTHWEST WINDS WILL BE FOUND THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1030 AM CDT WED JUL 31 2013/
UPDATE...MADE MINOR TWEAK TO SKY FCST TODAY AND POPS. MAIN THEME
REMAINS THE PROGRESSION OF THE SFC COLD FRONT SOUTH AND EAST OF THE
CWA THIS AFTERNOON. RW/TRW POTENTIAL REMAINS OVER WISC ZONES WITH
FRONTAL CONVERGENCE/INSTABILITY...AND UNDER STEEPENING LAPSE RATES
OVER NRN MN ZONES. LATEST RAP13 SHOWS AN AREA OF 85/70H LAPSE
RATES OF 6C/KM TO 6.5C/KM PUSHING ACROSS BORDERLAND. DEEP LAYER
MOISTURE IS QUESTIONABLE OVER NWRN CORNER OF CWA. 85/70H RH IS
70 TO 90 PERCENT ACROSS ARROWHEAD SO BETTER CHC APPEARS TO BE IN
THAT LOCATION. PUSHED MAX TEMPS A FEW DEGREES HIGHER NEAR LAKEFRONT
IN DLH VICINITY AS WESTERLY WINDS DOWNSLOPE TO SUPERIOR. GUSTY
WINDS WILL INCREASE TODAY OVER NE MN ZONES AS MIXING LAYER DEEPENS
SIGNIFICANTLY AND TAPS INTO HIGHER WINDS ALOFT.
PREV DISCUSSION... /ISSUED 356 AM CDT WED JUL 31 2013/
SHORT TERM...TODAY THROUGH THURSDAY.
AT 330 AM...ISOLATED SHOWERS AND THUNDERSTORMS WERE DEVELOPING
ACROSS THE REGION. THE STRONGEST STORM WAS MOVING QUICKLY TOWARD
THE WESTERN PORTION OF THE CWA...SPECIFICALLY CASS COUNTY.
TEMPERATURES AT 3 AM RANGED FROM THE MID 50S TO THE MID 60S.
PATCHY FOG ALSO WAS FOUND ACROSS THE CWA. THERE HAS BEEN SOME
IMPROVEMENT AS THICKER CLOUDS HAVE MOVED IN.
THE MAIN FOCUS FOR TODAY IS ON THUNDERSTORM POTENTIAL. A FRONTAL
BOUNDARY WILL CONTINUE TO MOVE TO THE SOUTH AND EAST ACROSS THE
REGION TODAY...WITH ISOLATED THUNDERSTORMS DEVELOPING ALONG AND
AHEAD OF THE FRONT. IN ADDITION...ANOTHER TROUGH WILL FOLLOW
BEHIND THE FRONT. TOUGH TO PUT TOO MUCH INTO TIMING TODAY BUT
THINK ISOLATED WORDING WILL COVER IT WELL. IN ADDITION...THERE
SHOULD BE SOME DIURNAL SHOWERS AND STORMS ACROSS THE NORTH BY THIS
AFTERNOON. THE HRRR...4 KM NMM AND RAP ARE ALL INDICATING THAT
THERE WILL BE SOME DEVELOPMENT DUE TO DAYTIME HEATING WITH SOME
WEAK INSTABILITY BY THIS AFTERNOON. THE BEST CHANCE FOR SEEING
SOME STRONGER STORMS IS IN EC MN AND NW WI...WHERE SPC HAS A 5
PERCENT WIND AND HAIL CONTOUR.
WITH THE LOSS OF DAYTIME HEATING WE SHOULD SEE A QUICK DEMISE TO
THE SHOWERS AND THUNDERSTORMS TONIGHT. WITH COLD AIR ALOFT AND AN
UPPER LEVEL SHORTWAVE AND VORT MAX...WE SHOULD SEE MORE DIURNAL
ACTIVITY ON THURSDAY SO WILL CONTINUE WITH SMALLER POPS ACROSS
MUCH OF THE AREA BY AFTERNOON.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
THURSDAY NIGHT A WEAK TROUGH AXIS CONTINUES TO MOVE ACROSS THE
FORECAST AREA AS A SHORTWAVE MOVES THROUGH THE UPPER FLOW. SOME
MODELS ARE GENERATING A NICE MCS OVER THE FORECAST AREA AND THEN
DRIVING IT SOUTHEAST ALONG WITH THE UPPER LEVEL FLOW. BETTER
INSTABILITY WILL BE FARTHER SOUTH ALONG THE STRONGER BAROCLINIC ZONE
ACROSS SOUTH DAKOTA EXTENDING INTO IOWA...SO AM NOT TERRIBLY EXCITED
ABOUT ANYTHING SIGNIFICANT THURSDAY NIGHT...BUT AM CARRYING SOME
CHANCE POPS FOR AT LEAST A PORTION OF THE AREA. MUCH IS GOING TO
DEPEND ON THE TIMING OF THE SHORTWAVE WHICH IS HANDLED IN VARYING
WAYS BY THE MODELS THIS MORNING. MIN TEMPS TO BE KEPT MILD BY EXTRA
CLOUD COVER...AND WILL BE MAINLY IN THE 50S.
FRIDAY THROUGH MOST OF SUNDAY A STRONG SURFACE RIDGE BUILDS INTO
THE REGION. ON FRIDAY BEFORE THE RIDGE GETS FIRMLY ESTABLISHED HAVE
SOME SLIGHT CHANCE POPS AS CYCLONIC FLOW ALOFT INTERACTS WITH SOME
LINGERING LOW LEVEL MOISTURE AND CONVERGENCE. TEMPERATURES COOL OFF
FAIRLY SIGNIFICANTLY BY FRIDAY NIGHT AND SATURDAY...WITH ANOTHER
NIGHT WITH SOME 40S ALL THREE NIGHTS...AND HIGHS ONLY IN THE LOW 70S
SATURDAY.
LATE SUNDAY...SUNDAY NIGHT AND MONDAY THINGS BEGIN TO SHIFT AS ANOTHER
SHORTWAVE DIVES THROUGH THE UPPER LEVEL FLOW AND THE SURFACE RIDGE
SHIFTS EAST OF THE AREA. THIS ALLOWS THE BAROCLINIC ZONE TO SHIFT
NORTH INTO SOUTH DAKOTA AND SOUTHERN MINNESOTA...AND WITH THE UPPER
LEVEL JET OVER NORTHERN MINNESOTA BY SUNDAY NIGHT AN MCS CAN BE
EXPECTED TO GENERATE SOMEWHERE NEAR OR SOUTH OF THE FORECAST AREA
THAT NIGHT. HOWEVER...AM NOT TOO CONVINCED IT WILL BE THIS FAR
NORTH AND HAVE LIMITED HIGHER POPS TO THE SOUTHERN COUNTIES WITH
LESS ACROSS THE NORTH. TEMPERATURES REMAIN COOL WITH HIGHS IN THE
LOW 70S. THE NORTHWEST FLOW CONTINUES INTO TUESDAY AND THERE ARE
SOME INDICATIONS THAT WE WILL HAVE ANOTHER SHORTWAVE DUE THROUGH
WITH ANOTHER CHANCE OF PRECIPITATION...BUT CONFIDENCE IS NOT VERY
HIGH AT THIS TIME AND HAVE LIMITED POPS. TEMPERATURES TO REMAIN
NEAR OR SLIGHTLY BELOW NORMAL.
&&
.POINT TEMPS/POPS...
DLH 76 53 74 55 / 20 10 20 20
INL 71 49 74 51 / 20 20 30 10
BRD 76 52 76 55 / 20 10 10 10
HYR 79 50 76 53 / 20 10 20 30
ASX 76 52 75 54 / 20 20 20 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...GRANING
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1030 AM CDT WED JUL 31 2013
.UPDATE...MADE MINOR TWEAK TO SKY FCST TODAY AND POPS. MAIN THEME
REMAINS THE PROGRESSION OF THE SFC COLD FRONT SOUTH AND EAST OF THE
CWA THIS AFTERNOON. RW/TRW POTENTIAL REMAINS OVER WISC ZONES WITH
FRONTAL CONVERGENCE/INSTABILITY...AND UNDER STEEPENING LAPSE RATES
OVER NRN MN ZONES. LATEST RAP13 SHOWS AN AREA OF 85/70H LAPSE
RATES OF 6C/KM TO 6.5C/KM PUSHING ACROSS BORDERLAND. DEEP LAYER
MOISTURE IS QUESTIONABLE OVER NWRN CORNER OF CWA. 85/70H RH IS
70 TO 90 PERCENT ACROSS ARROWHEAD SO BETTER CHC APPEARS TO BE IN
THAT LOCATION. PUSHED MAX TEMPS A FEW DEGREES HIGHER NEAR LAKEFRONT
IN DLH VICINITY AS WESTERLY WINDS DOWNSLOPE TO SUPERIOR. GUSTY
WINDS WILL INCREASE TODAY OVER NE MN ZONES AS MIXING LAYER DEEPENS
SIGNIFICANTLY AND TAPS INTO HIGHER WINDS ALOFT.
&&
.PREV DISCUSSION... /ISSUED 647 AM CDT WED JUL 31 2013/
AVIATION...
A COLD FRONT SLOWLY MOVING THROUGH THE REGION TODAY IS EXPECTED TO
BRING SCATTERED SHOWERS AND A FEW THUNDERSTORMS THROUGH EARLY
AFTERNOON. PATCHY EARLY MORNING FOG IS QUICKLY BURNING OFF...AND
EXPECT VFR CONDITIONS BY 15Z THIS MORNING. KHYR CURRENTLY HAS LIFR
CONDITIONS IN FOG AND STRATUS...AND WILL TAKE A LITTLE LONGER TO
IMPROVE TO VFR. AFTERWARDS...MAINLY VFR CONDITIONS EXPECTED THROUGH
THE PERIOD. THOUGH CONVECTION EXPECTED UNTIL LATE AFTERNOON OR
EARLY EVENING...COVERAGE EXPECTED TO BE QUITE LOW AND POTENTIAL
FOR A PARTICULAR TERMINAL TO BE AFFECTED KIND OF LOW. WILL HAVE TO
MONITOR FOR LATER UPDATES. BEHIND FRONT...GUSTY WNW TO NW WINDS
WILL DEVELOP BY LATE AFTERNOON IN THE WAKE OF THE COLD FRONT. VFR
CONDITIONS ARE EXPECTED THROUGH THIS EVENING AND OVERNIGHT TONIGHT.
PREV DISCUSSION... /ISSUED 356 AM CDT WED JUL 31 2013/
SHORT TERM...TODAY THROUGH THURSDAY.
AT 330 AM...ISOLATED SHOWERS AND THUNDERSTORMS WERE DEVELOPING
ACROSS THE REGION. THE STRONGEST STORM WAS MOVING QUICKLY TOWARD
THE WESTERN PORTION OF THE CWA...SPECIFICALLY CASS COUNTY.
TEMPERATURES AT 3 AM RANGED FROM THE MID 50S TO THE MID 60S.
PATCHY FOG ALSO WAS FOUND ACROSS THE CWA. THERE HAS BEEN SOME
IMPROVEMENT AS THICKER CLOUDS HAVE MOVED IN.
THE MAIN FOCUS FOR TODAY IS ON THUNDERSTORM POTENTIAL. A FRONTAL
BOUNDARY WILL CONTINUE TO MOVE TO THE SOUTH AND EAST ACROSS THE
REGION TODAY...WITH ISOLATED THUNDERSTORMS DEVELOPING ALONG AND
AHEAD OF THE FRONT. IN ADDITION...ANOTHER TROUGH WILL FOLLOW
BEHIND THE FRONT. TOUGH TO PUT TOO MUCH INTO TIMING TODAY BUT
THINK ISOLATED WORDING WILL COVER IT WELL. IN ADDITION...THERE
SHOULD BE SOME DIURNAL SHOWERS AND STORMS ACROSS THE NORTH BY THIS
AFTERNOON. THE HRRR...4 KM NMM AND RAP ARE ALL INDICATING THAT
THERE WILL BE SOME DEVELOPMENT DUE TO DAYTIME HEATING WITH SOME
WEAK INSTABILITY BY THIS AFTERNOON. THE BEST CHANCE FOR SEEING
SOME STRONGER STORMS IS IN EC MN AND NW WI...WHERE SPC HAS A 5
PERCENT WIND AND HAIL CONTOUR.
WITH THE LOSS OF DAYTIME HEATING WE SHOULD SEE A QUICK DEMISE TO
THE SHOWERS AND THUNDERSTORMS TONIGHT. WITH COLD AIR ALOFT AND AN
UPPER LEVEL SHORTWAVE AND VORT MAX...WE SHOULD SEE MORE DIURNAL
ACTIVITY ON THURSDAY SO WILL CONTINUE WITH SMALLER POPS ACROSS
MUCH OF THE AREA BY AFTERNOON.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
THURSDAY NIGHT A WEAK TROUGH AXIS CONTINUES TO MOVE ACROSS THE
FORECAST AREA AS A SHORTWAVE MOVES THROUGH THE UPPER FLOW. SOME
MODELS ARE GENERATING A NICE MCS OVER THE FORECAST AREA AND THEN
DRIVING IT SOUTHEAST ALONG WITH THE UPPER LEVEL FLOW. BETTER
INSTABILITY WILL BE FARTHER SOUTH ALONG THE STRONGER BAROCLINIC ZONE
ACROSS SOUTH DAKOTA EXTENDING INTO IOWA...SO AM NOT TERRIBLY EXCITED
ABOUT ANYTHING SIGNIFICANT THURSDAY NIGHT...BUT AM CARRYING SOME
CHANCE POPS FOR AT LEAST A PORTION OF THE AREA. MUCH IS GOING TO
DEPEND ON THE TIMING OF THE SHORTWAVE WHICH IS HANDLED IN VARYING
WAYS BY THE MODELS THIS MORNING. MIN TEMPS TO BE KEPT MILD BY EXTRA
CLOUD COVER...AND WILL BE MAINLY IN THE 50S.
FRIDAY THROUGH MOST OF SUNDAY A STRONG SURFACE RIDGE BUILDS INTO
THE REGION. ON FRIDAY BEFORE THE RIDGE GETS FIRMLY ESTABLISHED HAVE
SOME SLIGHT CHANCE POPS AS CYCLONIC FLOW ALOFT INTERACTS WITH SOME
LINGERING LOW LEVEL MOISTURE AND CONVERGENCE. TEMPERATURES COOL OFF
FAIRLY SIGNIFICANTLY BY FRIDAY NIGHT AND SATURDAY...WITH ANOTHER
NIGHT WITH SOME 40S ALL THREE NIGHTS...AND HIGHS ONLY IN THE LOW 70S
SATURDAY.
LATE SUNDAY...SUNDAY NIGHT AND MONDAY THINGS BEGIN TO SHIFT AS ANOTHER
SHORTWAVE DIVES THROUGH THE UPPER LEVEL FLOW AND THE SURFACE RIDGE
SHIFTS EAST OF THE AREA. THIS ALLOWS THE BAROCLINIC ZONE TO SHIFT
NORTH INTO SOUTH DAKOTA AND SOUTHERN MINNESOTA...AND WITH THE UPPER
LEVEL JET OVER NORTHERN MINNESOTA BY SUNDAY NIGHT AN MCS CAN BE
EXPECTED TO GENERATE SOMEWHERE NEAR OR SOUTH OF THE FORECAST AREA
THAT NIGHT. HOWEVER...AM NOT TOO CONVINCED IT WILL BE THIS FAR
NORTH AND HAVE LIMITED HIGHER POPS TO THE SOUTHERN COUNTIES WITH
LESS ACROSS THE NORTH. TEMPERATURES REMAIN COOL WITH HIGHS IN THE
LOW 70S. THE NORTHWEST FLOW CONTINUES INTO TUESDAY AND THERE ARE
SOME INDICATIONS THAT WE WILL HAVE ANOTHER SHORTWAVE DUE THROUGH
WITH ANOTHER CHANCE OF PRECIPITATION...BUT CONFIDENCE IS NOT VERY
HIGH AT THIS TIME AND HAVE LIMITED POPS. TEMPERATURES TO REMAIN
NEAR OR SLIGHTLY BELOW NORMAL.
&&
.POINT TEMPS/POPS...
DLH 76 53 74 55 / 20 10 20 10
INL 71 49 74 51 / 20 20 30 20
BRD 76 52 76 55 / 20 10 10 10
HYR 79 50 76 53 / 20 10 20 20
ASX 76 52 75 54 / 20 20 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION
NWS DULUTH MN
647 AM CDT WED JUL 31 2013
.AVIATION...
A COLD FRONT SLOWLY MOVING THROUGH THE REGION TODAY IS EXPECTED TO
BRING SCATTERED SHOWERS AND A FEW THUNDERSTORMS THROUGH EARLY
AFTERNOON. PATCHY EARLY MORNING FOG IS QUICKLY BURNING OFF...AND
EXPECT VFR CONDITIONS BY 15Z THIS MORNING. KHYR CURRENTLY HAS LIFR
CONDITIONS IN FOG AND STRATUS...AND WILL TAKE A LITTLE LONGER TO
IMPROVE TO VFR. AFTERWARDS...MAINLY VFR CONDITIONS EXPECTED THROUGH
THE PERIOD. THOUGH CONVECTION EXPECTED UNTIL LATE AFTERNOON OR
EARLY EVENING...COVERAGE EXPECTED TO BE QUITE LOW AND POTENTIAL
FOR A PARTICULAR TERMINAL TO BE AFFECTED KIND OF LOW. WILL HAVE TO
MONITOR FOR LATER UPDATES. BEHIND FRONT...GUSTY WNW TO NW WINDS
WILL DEVELOP BY LATE AFTERNOON IN THE WAKE OF THE COLD FRONT. VFR
CONDITIONS ARE EXPECTED THROUGH THIS EVENING AND OVERNIGHT TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 356 AM CDT WED JUL 31 2013/
SHORT TERM...TODAY THROUGH THURSDAY.
AT 330 AM...ISOLATED SHOWERS AND THUNDERSTORMS WERE DEVELOPING
ACROSS THE REGION. THE STRONGEST STORM WAS MOVING QUICKLY TOWARD
THE WESTERN PORTION OF THE CWA...SPECIFICALLY CASS COUNTY.
TEMPERATURES AT 3 AM RANGED FROM THE MID 50S TO THE MID 60S.
PATCHY FOG ALSO WAS FOUND ACROSS THE CWA. THERE HAS BEEN SOME
IMPROVEMENT AS THICKER CLOUDS HAVE MOVED IN.
THE MAIN FOCUS FOR TODAY IS ON THUNDERSTORM POTENTIAL. A FRONTAL
BOUNDARY WILL CONTINUE TO MOVE TO THE SOUTH AND EAST ACROSS THE
REGION TODAY...WITH ISOLATED THUNDERSTORMS DEVELOPING ALONG AND
AHEAD OF THE FRONT. IN ADDITION...ANOTHER TROUGH WILL FOLLOW
BEHIND THE FRONT. TOUGH TO PUT TOO MUCH INTO TIMING TODAY BUT
THINK ISOLATED WORDING WILL COVER IT WELL. IN ADDITION...THERE
SHOULD BE SOME DIURNAL SHOWERS AND STORMS ACROSS THE NORTH BY THIS
AFTERNOON. THE HRRR...4 KM NMM AND RAP ARE ALL INDICATING THAT
THERE WILL BE SOME DEVELOPMENT DUE TO DAYTIME HEATING WITH SOME
WEAK INSTABILITY BY THIS AFTERNOON. THE BEST CHANCE FOR SEEING
SOME STRONGER STORMS IS IN EC MN AND NW WI...WHERE SPC HAS A 5
PERCENT WIND AND HAIL CONTOUR.
WITH THE LOSS OF DAYTIME HEATING WE SHOULD SEE A QUICK DEMISE TO
THE SHOWERS AND THUNDERSTORMS TONIGHT. WITH COLD AIR ALOFT AND AN
UPPER LEVEL SHORTWAVE AND VORT MAX...WE SHOULD SEE MORE DIURNAL
ACTIVITY ON THURSDAY SO WILL CONTINUE WITH SMALLER POPS ACROSS
MUCH OF THE AREA BY AFTERNOON.
LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
THURSDAY NIGHT A WEAK TROUGH AXIS CONTINUES TO MOVE ACROSS THE
FORECAST AREA AS A SHORTWAVE MOVES THROUGH THE UPPER FLOW. SOME
MODELS ARE GENERATING A NICE MCS OVER THE FORECAST AREA AND THEN
DRIVING IT SOUTHEAST ALONG WITH THE UPPER LEVEL FLOW. BETTER
INSTABILITY WILL BE FARTHER SOUTH ALONG THE STRONGER BAROCLINIC ZONE
ACROSS SOUTH DAKOTA EXTENDING INTO IOWA...SO AM NOT TERRIBLY EXCITED
ABOUT ANYTHING SIGNIFICANT THURSDAY NIGHT...BUT AM CARRYING SOME
CHANCE POPS FOR AT LEAST A PORTION OF THE AREA. MUCH IS GOING TO
DEPEND ON THE TIMING OF THE SHORTWAVE WHICH IS HANDLED IN VARYING
WAYS BY THE MODELS THIS MORNING. MIN TEMPS TO BE KEPT MILD BY EXTRA
CLOUD COVER...AND WILL BE MAINLY IN THE 50S.
FRIDAY THROUGH MOST OF SUNDAY A STRONG SURFACE RIDGE BUILDS INTO
THE REGION. ON FRIDAY BEFORE THE RIDGE GETS FIRMLY ESTABLISHED HAVE
SOME SLIGHT CHANCE POPS AS CYCLONIC FLOW ALOFT INTERACTS WITH SOME
LINGERING LOW LEVEL MOISTURE AND CONVERGENCE. TEMPERATURES COOL OFF
FAIRLY SIGNIFICANTLY BY FRIDAY NIGHT AND SATURDAY...WITH ANOTHER
NIGHT WITH SOME 40S ALL THREE NIGHTS...AND HIGHS ONLY IN THE LOW 70S
SATURDAY.
LATE SUNDAY...SUNDAY NIGHT AND MONDAY THINGS BEGIN TO SHIFT AS ANOTHER
SHORTWAVE DIVES THROUGH THE UPPER LEVEL FLOW AND THE SURFACE RIDGE
SHIFTS EAST OF THE AREA. THIS ALLOWS THE BAROCLINIC ZONE TO SHIFT
NORTH INTO SOUTH DAKOTA AND SOUTHERN MINNESOTA...AND WITH THE UPPER
LEVEL JET OVER NORTHERN MINNESOTA BY SUNDAY NIGHT AN MCS CAN BE
EXPECTED TO GENERATE SOMEWHERE NEAR OR SOUTH OF THE FORECAST AREA
THAT NIGHT. HOWEVER...AM NOT TOO CONVINCED IT WILL BE THIS FAR
NORTH AND HAVE LIMITED HIGHER POPS TO THE SOUTHERN COUNTIES WITH
LESS ACROSS THE NORTH. TEMPERATURES REMAIN COOL WITH HIGHS IN THE
LOW 70S. THE NORTHWEST FLOW CONTINUES INTO TUESDAY AND THERE ARE
SOME INDICATIONS THAT WE WILL HAVE ANOTHER SHORTWAVE DUE THROUGH
WITH ANOTHER CHANCE OF PRECIPITATION...BUT CONFIDENCE IS NOT VERY
HIGH AT THIS TIME AND HAVE LIMITED POPS. TEMPERATURES TO REMAIN
NEAR OR SLIGHTLY BELOW NORMAL.
&&
.POINT TEMPS/POPS...
DLH 76 53 74 55 / 20 20 20 20
INL 71 49 74 51 / 20 20 30 10
BRD 76 52 76 55 / 20 10 10 10
HYR 79 50 76 53 / 20 20 20 30
ASX 76 52 75 54 / 20 20 20 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
356 AM CDT WED JUL 31 2013
.SHORT TERM...TODAY THROUGH THURSDAY.
AT 330 AM...ISOLATED SHOWERS AND THUNDERSTORMS WERE DEVELOPING
ACROSS THE REGION. THE STRONGEST STORM WAS MOVING QUICKLY TOWARD
THE WESTERN PORTION OF THE CWA...SPECIFICALLY CASS COUNTY.
TEMPERATURES AT 3 AM RANGED FROM THE MID 50S TO THE MID 60S.
PATCHY FOG ALSO WAS FOUND ACROSS THE CWA. THERE HAS BEEN SOME
IMPROVEMENT AS THICKER CLOUDS HAVE MOVED IN.
THE MAIN FOCUS FOR TODAY IS ON THUNDERSTORM POTENTIAL. A FRONTAL
BOUNDARY WILL CONTINUE TO MOVE TO THE SOUTH AND EAST ACROSS THE
REGION TODAY...WITH ISOLATED THUNDERSTORMS DEVELOPING ALONG AND
AHEAD OF THE FRONT. IN ADDITION...ANOTHER TROUGH WILL FOLLOW
BEHIND THE FRONT. TOUGH TO PUT TOO MUCH INTO TIMING TODAY BUT
THINK ISOLATED WORDING WILL COVER IT WELL. IN ADDITION...THERE
SHOULD BE SOME DIURNAL SHOWERS AND STORMS ACROSS THE NORTH BY THIS
AFTERNOON. THE HRRR...4 KM NMM AND RAP ARE ALL INDICATING THAT
THERE WILL BE SOME DEVELOPMENT DUE TO DAYTIME HEATING WITH SOME
WEAK INSTABILITY BY THIS AFTERNOON. THE BEST CHANCE FOR SEEING
SOME STRONGER STORMS IS IN EC MN AND NW WI...WHERE SPC HAS A 5
PERCENT WIND AND HAIL CONTOUR.
WITH THE LOSS OF DAYTIME HEATING WE SHOULD SEE A QUICK DEMISE TO
THE SHOWERS AND THUNDERSTORMS TONIGHT. WITH COLD AIR ALOFT AND AN
UPPER LEVEL SHORTWAVE AND VORT MAX...WE SHOULD SEE MORE DIURNAL
ACTIVITY ON THURSDAY SO WILL CONTINUE WITH SMALLER POPS ACROSS
MUCH OF THE AREA BY AFTERNOON.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY.
THURSDAY NIGHT A WEAK TROUGH AXIS CONTINUES TO MOVE ACROSS THE
FORECAST AREA AS A SHORTWAVE MOVES THROUGH THE UPPER FLOW. SOME
MODELS ARE GENERATING A NICE MCS OVER THE FORECAST AREA AND THEN
DRIVING IT SOUTHEAST ALONG WITH THE UPPER LEVEL FLOW. BETTER
INSTABILITY WILL BE FARTHER SOUTH ALONG THE STRONGER BAROCLINIC ZONE
ACROSS SOUTH DAKOTA EXTENDING INTO IOWA...SO AM NOT TERRIBLY EXCITED
ABOUT ANYTHING SIGNIFICANT THURSDAY NIGHT...BUT AM CARRYING SOME
CHANCE POPS FOR AT LEAST A PORTION OF THE AREA. MUCH IS GOING TO
DEPEND ON THE TIMING OF THE SHORTWAVE WHICH IS HANDLED IN VARYING
WAYS BY THE MODELS THIS MORNING. MIN TEMPS TO BE KEPT MILD BY EXTRA
CLOUD COVER...AND WILL BE MAINLY IN THE 50S.
FRIDAY THROUGH MOST OF SUNDAY A STRONG SURFACE RIDGE BUILDS INTO
THE REGION. ON FRIDAY BEFORE THE RIDGE GETS FIRMLY ESTABLISHED HAVE
SOME SLIGHT CHANCE POPS AS CYCLONIC FLOW ALOFT INTERACTS WITH SOME
LINGERING LOW LEVEL MOISTURE AND CONVERGENCE. TEMPERATURES COOL OFF
FAIRLY SIGNIFICANTLY BY FRIDAY NIGHT AND SATURDAY...WITH ANOTHER
NIGHT WITH SOME 40S ALL THREE NIGHTS...AND HIGHS ONLY IN THE LOW 70S
SATURDAY.
LATE SUNDAY...SUNDAY NIGHT AND MONDAY THINGS BEGIN TO SHIFT AS ANOTHER
SHORTWAVE DIVES THROUGH THE UPPER LEVEL FLOW AND THE SURFACE RIDGE
SHIFTS EAST OF THE AREA. THIS ALLOWS THE BAROCLINIC ZONE TO SHIFT
NORTH INTO SOUTH DAKOTA AND SOUTHERN MINNESOTA...AND WITH THE UPPER
LEVEL JET OVER NORTHERN MINNESOTA BY SUNDAY NIGHT AN MCS CAN BE
EXPECTED TO GENERATE SOMEWHERE NEAR OR SOUTH OF THE FORECAST AREA
THAT NIGHT. HOWEVER...AM NOT TOO CONVINCED IT WILL BE THIS FAR
NORTH AND HAVE LIMITED HIGHER POPS TO THE SOUTHERN COUNTIES WITH
LESS ACROSS THE NORTH. TEMPERATURES REMAIN COOL WITH HIGHS IN THE
LOW 70S. THE NORTHWEST FLOW CONTINUES INTO TUESDAY AND THERE ARE
SOME INDICATIONS THAT WE WILL HAVE ANOTHER SHORTWAVE DUE THROUGH
WITH ANOTHER CHANCE OF PRECIPITATION...BUT CONFIDENCE IS NOT VERY
HIGH AT THIS TIME AND HAVE LIMITED POPS. TEMPERATURES TO REMAIN
NEAR OR SLIGHTLY BELOW NORMAL.
&&
.AVIATION.../06Z TAF ISSUANCE/
AN APPROACHING COLD FRONT WILL MOVE THROUGH NORTHEAST MINNESOTA AND
NORTHWEST WISCONSIN OVERNIGHT. IT COULD BRING SOME SHOWERS AND
STORMS TO THE REGION THROUGH EARLY WEDNESDAY AFTERNOON. PATCHY BR
AND FG COULD BRING PERIODS OF LIFR/IFR/MVFR CIGS AND VSBYS TO THE
KHYR/KDLH/KHIB AREAS THROUGH EARLY THIS MORNING...WITH KHYR LIKELY
BEING THE MOST AFFECTED. GUSTY WNW TO NW WINDS WILL DEVELOP BY
THIS AFTERNOON IN THE WAKE OF THE COLD FRONT. VFR CONDITIONS ARE
EXPECTED FOR LATE THIS MORNING THROUGH THIS EVENING.
&&
.POINT TEMPS/POPS...
DLH 76 53 74 55 / 20 20 20 20
INL 71 49 74 51 / 20 20 30 10
BRD 76 52 76 55 / 20 10 10 10
HYR 79 50 76 53 / 20 20 20 30
ASX 76 52 75 54 / 20 20 20 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...DAP
LONG TERM....LE
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
701 PM CDT THU AUG 1 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 PM CDT THU AUG 1 2013
MORNING MAP ANALYSIS INDICATES MID TO UPPER LEVEL RIDGING OVER THE
WESTERN CONUS...WITH A TROUGH OVER THE EAST. MID TO UPPER LEVEL JET
ENERGY EXTENDS FROM THE WEST-CENTRAL CONUS...NORTHEAST INTO THE
NORTHERN ROCKY MOUNTAIN RANGE...AND THEN SOUTHEAST ACROSS PORTIONS
OF THE PLAINS AND MISSISSIPPI VALLEY...AND FINALLY EAST/NORTHEAST
INTO THE EASTERN CONUS. NORTHWESTERLY MID TO UPPER LEVEL FLOW
PERSISTS OVER THE CENTRAL PLAINS AS A RESULT. A ~110KT UPPER LEVEL
JET STREAK IS ALSO NOTED EXTENDING FROM THE NORTHERN
PLAINS...SOUTHEAST INTO THE MID-MISSISSIPPI VALLEY. MID TO UPPER
LEVEL FLOW MAXES OUT AT AROUND 100KTS NEAR 200MB PER RAP ANALYSIS
AND 12Z SOUNDING DATA FROM KOAX. AT THE SURFACE A RIDGE OF HIGH
PRESSURE EXTENDS FROM THE MISSOURI RIVER VALLEY...SOUTH/SOUTHEAST
INTO PORTIONS OF THE MID-MISSISSIPPI VALLEY. LEE SIDE TROUGHING ALSO
EXTENDS FROM SOUTHEASTERN WYOMING INTO EASTERN COLORADO AND AS A
RESULT...SOUTHERLY LOW LEVEL FLOW IS INFILTRATING OUR CWA.
FOR THE REST OF THIS AFTERNOON AND EVENING...CONTINUED SOUTHERLY LOW
LEVEL FLOW...ENHANCED BY THE DEVELOPMENT OF A 25-30KT 850MB JET
STREAK...WILL PROMOTE INCREASING THERMAL ADVECTION ACROSS MUCH OF
OUR AREA. ISENTROPIC UPGLIDE AND
SATURATION...PRIMARILY ALONG THE 310-320K SURFACES...IS EXPECTED TO
PROMOTE PRECIPITATION PRODUCTION ACROSS THE AREA. INCREASED VALUES
OF LOW LEVEL MOISTURE SHOULD CONTINUE PROMOTING DECENT VALUES OF
POTENTIAL INSTABILITY...WITH THE NAM AND OPERATIONAL GFS BOTH
SUGGESTING MUCAPE VALUES NEAR 3000J/KG ACROSS MUCH OF THE AREA. IN
ADDITION TO THE POTENTIAL INSTABILITY...DEEP LAYER BULK SHEAR VALUES
ON THE ORDER OF 40-50KTS IS ALSO EXPECTED. GIVEN ALL THIS...SEVERE
WEATHER REMAINS POSSIBLE THIS AFTERNOON INTO THIS EVENING...WITH
LARGE HAIL AND STRONG THUNDERSTORM WIND GUSTS BEING THE PRIMARY
SEVERE WEATHER THREATS. IN ADDITION THE HAIL AND WIND THREAT
HOWEVER...FORECAST PROXIMITY SOUNDINGS FROM VARIOUS MODELS SUGGEST A
SIGNIFICANTLY VEERING LOW LEVEL WIND PROFILE THUS HELPING PROMOTE
SRH VALUES NEAR 200M^2/S^2 ACROSS PORTIONS OF OUR CWA. GIVEN
THIS...WILL ALSO CONTINUE THE TORNADO MENTION IN THE HWO.
GUIDANCE SUGGESTS THE AFOREMENTIONED THERMAL ADVECTION SHOULD HELP
MAINTAIN PRECIPITATION PRODUCTION ACROSS THE AREA TONIGHT...WITH
MUCH OF THIS ACTIVITY MOVING OFF TO EAST BY EARLY FRIDAY MORNING. IT
WOULD APPEAR AS THOUGH THE SEVERE WEATHER THREAT SHOULD DIMINISH
HEADING INTO THE OVERNIGHT HOURS. THAT BEING SAID...WITH A
PERSISTENT SOUTHERLY LOW LEVEL WIND FIELD...INCREASING SIGNIFICANTLY
ABOVE THE BOUNDARY LAYER PRIMARILY DUE TO A ~50KT LOW LEVEL
JET...MAY HELP PROMOTE NOCTURNAL MCS DEVELOPMENT. WILL CONTINUE THE
MENTION OF SEVERE WEATHER ACROSS THE AREA THROUGH THE OVERNIGHT
HOURS AS A RESULT...BUT THE DETAILS OF ANY POTENTIAL MCS DEVELOPMENT
WILL NOT LIKELY BECOME ANY MORE CLEAR UNTIL LATER TONIGHT.
THE PRIMARY AXIS OF THERMAL ADVECTION SHOULD DEPART THE AREA TO THE
EAST ON FRIDAY...THUS ALLOWING FOR DECREASING PRECIPITATION CHANCES.
THAT BEING SAID...MID LEVEL PERTURBATIONS MOVING OVER THE AREA WITHIN
THE MEAN FLOW SHOULD STILL PROMOTE ENOUGH OMEGA FOR FURTHER
PRECIPITATION PRODUCTION ACROSS PORTIONS OF OUR CWA STARTING FRIDAY
AFTERNOON. SHOULD THUNDERSTORM ACTIVITY BE REALIZED FRIDAY
AFTERNOON...THEN SEVERE WEATHER COULD ONCE AGAIN BE REALIZED AS
GUIDANCE SUGGESTS MUCAPE VALUES NEAR 3000J/KG WILL ACCOMPANY DEEP
LAYER BULK SHEAR VALUES OF 30-40KTS. GIVEN ALL THIS...WILL GO AHEAD
AND OUTLOOK SEVERE WEATHER FOR FRIDAY AS WELL.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CDT THU AUG 1 2013
FORECAST CONCERNS MAINLY FOCUSED ON THUNDERSTORMS.
MODELS ARE IN GOOD AGREEMENT THAT THE NORTHWEST FLOW REGIME WILL
PERSIST THROUGH THE PERIOD. THUS...EXPECT A PERIOD OF UNSETTLED
WEATHER WITH NORMAL OR BELOW NORMAL TEMPERATURES.
AT THE SURFACE...A BROAD AREA OF LOW PRESSURE ON THE LEE SIDE OF
THE ROCKIES WILL ANCHOR A WEAK FRONTAL BOUNDARY THAT WILL
OSCILLATE FROM KS TO SD THROUGH THE PERIOD. THE LOCATION OF THIS
BOUNDARY WILL BE THE FOCUS OF AFTERNOON CONVECTIVE INITIATION. THEN
STORMS SHOULD DRIFT SOUTH AND EAST THROUGH THE EVENING HOURS AS AN
MCS. THERE WILL BE GOOD INSTABILITY AND MOISTURE AVAILABLE...SO
SEVERE STORMS CAN NOT BE RULED OUT.
ALOFT...THE NORTHWEST FLOW WILL ALLOW FREQUENT AND WEAK WAVES TO
MOVE OVER THE AREA. THIS WILL OFFER ENOUGH SUPPORT TO GET INITIATE
THE CONVECTION.
TOWARDS THE END OF THE PERIOD (THURSDAY) A STRONGER COOL FRONT IS
FORECAST TO MOVE SOUTH ACROSS THE AREA. IF THIS
OCCURS...TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL AND IT
WILL BE DRY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 656 PM CDT THU AUG 1 2013
THERE IS ONGOING SEVERE WEATHER TO THE NORTH OF KGRI AND SOME OF
THESE STRONG TO SEVERE STORMS MAY TRACK TROUGH KGRI BETWEEN 9 PM
AND 1 AM. STORMS WILL BACK BUILD TO THE WEST WHILE MOVING
SOUTHEAST. STRONG WIND GUSTS WILL BE POSSIBLE IN AND AROUND
THUNDERSTORMS. THUNDERSTORM ACTIVITY SHOULD DECREASE TOMORROW
MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...BRYANT
LONG TERM...EDDY
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1240 PM CDT WED JUL 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CDT WED JUL 31 2013
TODAY AND TONIGHT...HIGH PRESSURE HAS BUILT INTO SCNTL NEB IN WAKE
OF LAST NIGHTS CRUSHING TSTM EVENT. ALL INDICATIONS ARE THE
ATMOSPHERE WILL REMAIN NEARLY QUIET THIS AFTERNOON AND THIS EVENING.
THERE IS PERHAPS THE POTENTIAL FOR DESTABILIZATION THIS AFTN ACROSS
THE CNTL HIGH PLAINS. ISOLATED STORMS COULD DEVELOP ACROSS WRN NEB
WHICH WOULD MOVE EAST AND DISSIPATE IN THE EVENING ACROSS NCNTL NEB.
THERE IS ALSO THE POTENTIAL FOR DESTABILIZATION ACROSS SWRN AND
SCNTL NEB THIS AFTN AND THIS EVENING NORTH OF A SFC FRONT CURRENTLY
LOCATED ACROSS KS AND NERN COLORADO. SPC HAS OUTLOOKED FRONTIER
COUNTY NORTHEAST THROUGH CUSTER AND HOLT COUNTIES IN THEIR DAY 1
OUTLOOK FOR SEVERE TSTM DEVELOPMENT.
FOR THIS MORNING...A CLUSTER OF SHOWERS AND TSTMS ACROSS SWRN SD
COULD SWEEP EAST AND SOUTHEAST THROUGH PARTS OF NWRN AND NCNTL NEB.
THIS IS HIGHLY SPECULATIVE GIVEN THE MODEL DYNAMIC ADJUSTMENT
PROCESS DURING THE FIRST 12 HRS. THE RAP AND HRRR HAVE THEIR OWN
IDEAS. THE RAP SHOWS SCATTERED STORM COVERAGE ACROSS NCNTL NEB WHILE
THE HRRR IS SLOWER AND FARTHER EAST JUST BRUSHING HOLT AND BOYD
COUNTIES. THE FCST IS FOR ISOLATED SHRA/TSTM COVERAGE GIVEN CURRENT
RADAR TRENDS.
TEMPERATURES TODAY ARE ON THE COOL SIDE OF AN ENVELOP OF MID 70S TO
NEAR 90. A BLEND OF MODEL DATA PLUS BIAS CORRECTION YIELDED LOW TO
UPPER 80S FOR HIGHS UNDER SCATTERED AND BROKEN CLOUD COVER.
LASTLY...THE MODELS CONTINUE TO ADVERTISE A LATE NIGHT MCS DROPPING
THROUGH NWRN NEB AROUND 06Z AND THEN PEDDLING EAST AND SOUTHEAST
THROUGH MUCH OF NCNTL NEB BETWEEN 06Z AND 12Z. THE 06Z NAM SHOWS
MODEST ELEVATED CAP AROUND 1000 J/KG AND AN MCS DROPPING MORE SOUTH
THROUGH SCNTL NEB BY 12Z. GIVEN THE TRACK OF THE STORMS TUESDAY
EVENING THIS SOLN HAS SOME CREDIBILITY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED JUL 31 2013
ACTIVE WEATHER TO CONTINUE THROUGH THE PERIOD. A WARM FRONT WILL
EXTEND WEST TO EAST ACROSS THE AREA THURSDAY AND BE THE FOCUS FOR
TSTM DEVELOPMENT. CONTINUED NORTHWEST FLOW ALOFT WILL COMBINE WITH
EAST TO SOUTHEAST WINDS AT THE SFC...PRODUCING FAVORABLE SHEAR FOR
SUPERCELL TSTMS WITH LARGE HAIL AND DAMAGING WIND POTENTIAL. WILL
ALSO HAVE TO WATCH FOR HEAVY RAIN/FLOODING POTENTIAL...AS SOME AREAS
HAVE RECEIVED WELL OVER TWO INCHES OF RAIN THE LAST FEW DAYS.
VALENTINE FOR INSTANCE HAD OVER TWO INCHES OF RAIN JUST LAST
NIGHT.
THE AFOREMENTIONED FRONT WILL REMAIN IN THE AREA FRIDAY THROUGH THE
UPCOMING WEEKEND...AND CONTINUE TO BE THE FOCUS FOR AT LEAST
SCATTERED TSTM DEVELOPMENT. RICH MOISTURE...SHEAR...AND
INSTABILITY...WILL CONTINUE TO BRING THE THREAT FOR A FEW SEVERE
STORMS AS WELL AS LOCALIZED HEAVY RAIN.
BY EARLY NEXT WEEK...HIGH PRESSURE WILL TRY TO NUDGE SOUTH INTO THE
AREA FROM THE NORTHERN PLAINS/CANADA. THIS MAY FORCE THE RICHER
MOISTURE SOUTH INTO KANSAS AND OKLAHOMA...BUT STILLS APPEARS TO BE
ENOUGH MOISTURE IN THE AREA TO CONTINUE SOME SLIGHT AND LOW END
CHANCES FOR TSTM ACTIVITY.
TEMPERATURE WISE...WITH THE FRONT REMAINING IN THE AREA...ALONG WITH
CLOUDS AND PRECIPITATION FROM TIME TO TIME...HIGHS WILL REMAIN
GENERALLY IN THE 80S. OVERNIGHT LOWS WILL BE MILD WITH THE INCREASED
MOISTURE CONTENT IN THE AIR...WITH MOST LOCALS REMAINING IN THE 60S
AT NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1239 PM CDT WED JUL 31 2013
THE 18Z TAF ISSUANCE FOR KLBF AND KVTN. STRATUS DECK CONTINUES TO
BUILD TO THE SOUTHWEST ACROSS PORTIONS OF THE NORTH CENTRAL AND
CENTRAL SANDHILLS EARLY THIS AFTERNOON. MVFR FLIGHT CEILINGS HAVE
BEEN REPORTED AT BOTH KVTN AND KLBF...THUS WILL INCLUDE A MENTION AT
BOTH SITES FOR NOW THROUGH 00Z. THERE IS A BIT OF UNCERTAINTY ON
WHETHER OR NOT THE STRATUS WILL BREAK...SO UPDATES MAY BE NEEDED.
OTHERWISE THUNDERSTORM WILL INCREASE IN COVERAGE OVERNIGHT FROM WEST
TO EAST...WITH THE POTENTIAL OF VISIBILITY REDUCTIONS FROM HEAVY
RAIN. THE MOST SIGNIFICANT CONVECTION IS EXPECTED TO FORM LATE
TONIGHT WITH STORMS DEVELOPING ACROSS THE CNTL HIGH
PLAINS...BETWEEN 03Z- 06Z AND SPINNING SOUTH AND EAST THROUGH WRN
AND NCNTL NEB THROUGH 12Z THURSDAY. NOTE THAT THE NAM SHOWS TWO
ROUNDS OF STORMS RIPPING THROUGH THE FCST AREA AND THIS SEEMS
CREDIBLE GIVEN THE VERY ACTIVE WEATHER PATTERN UNDERWAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...JACOBS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
629 AM CDT WED JUL 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CDT WED JUL 31 2013
TODAY AND TONIGHT...HIGH PRESSURE HAS BUILT INTO SCNTL NEB IN WAKE
OF LAST NIGHTS CRUSHING TSTM EVENT. ALL INDICATIONS ARE THE
ATMOSPHERE WILL REMAIN NEARLY QUIET THIS AFTERNOON AND THIS EVENING.
THERE IS PERHAPS THE POTENTIAL FOR DESTABILIZATION THIS AFTN ACROSS
THE CNTL HIGH PLAINS. ISOLATED STORMS COULD DEVELOP ACROSS WRN NEB
WHICH WOULD MOVE EAST AND DISSIPATE IN THE EVENING ACROSS NCNTL NEB.
THERE IS ALSO THE POTENTIAL FOR DESTABILIZATION ACROSS SWRN AND
SCNTL NEB THIS AFTN AND THIS EVENING NORTH OF A SFC FRONT CURRENTLY
LOCATED ACROSS KS AND NERN COLORADO. SPC HAS OUTLOOKED FRONTIER
COUNTY NORTHEAST THROUGH CUSTER AND HOLT COUNTIES IN THEIR DAY 1
OUTLOOK FOR SEVERE TSTM DEVELOPMENT.
FOR THIS MORNING...A CLUSTER OF SHOWERS AND TSTMS ACROSS SWRN SD
COULD SWEEP EAST AND SOUTHEAST THROUGH PARTS OF NWRN AND NCNTL NEB.
THIS IS HIGHLY SPECULATIVE GIVEN THE MODEL DYNAMIC ADJUSTMENT
PROCESS DURING THE FIRST 12 HRS. THE RAP AND HRRR HAVE THEIR OWN
IDEAS. THE RAP SHOWS SCATTERED STORM COVERAGE ACROSS NCNTL NEB WHILE
THE HRRR IS SLOWER AND FARTHER EAST JUST BRUSHING HOLT AND BOYD
COUNTIES. THE FCST IS FOR ISOLATED SHRA/TSTM COVERAGE GIVEN CURRENT
RADAR TRENDS.
TEMPERATURES TODAY ARE ON THE COOL SIDE OF AN ENVELOP OF MID 70S TO
NEAR 90. A BLEND OF MODEL DATA PLUS BIAS CORRECTION YIELDED LOW TO
UPPER 80S FOR HIGHS UNDER SCATTERED AND BROKEN CLOUD COVER.
LASTLY...THE MODELS CONTINUE TO ADVERTISE A LATE NIGHT MCS DROPPING
THROUGH NWRN NEB AROUND 06Z AND THEN PEDDLING EAST AND SOUTHEAST
THROUGH MUCH OF NCNTL NEB BETWEEN 06Z AND 12Z. THE 06Z NAM SHOWS
MODEST ELEVATED CAP AROUND 1000 J/KG AND AN MCS DROPPING MORE SOUTH
THROUGH SCNTL NEB BY 12Z. GIVEN THE TRACK OF THE STORMS TUESDAY
EVENING THIS SOLN HAS SOME CREDIBILITY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED JUL 31 2013
ACTIVE WEATHER TO CONTINUE THROUGH THE PERIOD. A WARM FRONT WILL
EXTEND WEST TO EAST ACROSS THE AREA THURSDAY AND BE THE FOCUS FOR
TSTM DEVELOPMENT. CONTINUED NORTHWEST FLOW ALOFT WILL COMBINE WITH
EAST TO SOUTHEAST WINDS AT THE SFC...PRODUCING FAVORABLE SHEAR FOR
SUPERCELL TSTMS WITH LARGE HAIL AND DAMAGING WIND POTENTIAL. WILL
ALSO HAVE TO WATCH FOR HEAVY RAIN/FLOODING POTENTIAL...AS SOME AREAS
HAVE RECEIVED WELL OVER TWO INCHES OF RAIN THE LAST FEW DAYS.
VALENTINE FOR INSTANCE HAD OVER TWO INCHES OF RAIN JUST LAST
NIGHT.
THE AFOREMENTIONED FRONT WILL REMAIN IN THE AREA FRIDAY THROUGH THE
UPCOMING WEEKEND...AND CONTINUE TO BE THE FOCUS FOR AT LEAST
SCATTERED TSTM DEVELOPMENT. RICH MOISTURE...SHEAR...AND
INSTABILITY...WILL CONTINUE TO BRING THE THREAT FOR A FEW SEVERE
STORMS AS WELL AS LOCALIZED HEAVY RAIN.
BY EARLY NEXT WEEK...HIGH PRESSURE WILL TRY TO NUDGE SOUTH INTO THE
AREA FROM THE NORTHERN PLAINS/CANADA. THIS MAY FORCE THE RICHER
MOISTURE SOUTH INTO KANSAS AND OKLAHOMA...BUT STILLS APPEARS TO BE
ENOUGH MOISTURE IN THE AREA TO CONTINUE SOME SLIGHT AND LOW END
CHANCES FOR TSTM ACTIVITY.
TEMPERATURE WISE...WITH THE FRONT REMAINING IN THE AREA...ALONG WITH
CLOUDS AND PRECIPITATION FROM TIME TO TIME...HIGHS WILL REMAIN
GENERALLY IN THE 80S. OVERNIGHT LOWS WILL BE MILD WITH THE INCREASED
MOISTURE CONTENT IN THE AIR...WITH MOST LOCALS REMAINING IN THE 60S
AT NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 622 AM CDT WED JUL 31 2013
A BANK OF MVFR/LOCAL IFR HAS DEVELOPED ACROSS PARTS OF WRN NEB. THIS
BANK OF CLOUDS SHOULD LIFT TO VFR AROUND 15Z-17Z. ISOLATED
SHRA/TSTMS CONTINUE TO FIRE...MAINLY EAST OF HIGHWAY 83 THIS
MORNING. THIS INSTABILITY IS EXPECTED TO SHIFT EAST AND SOUTH AND
BECOME THE FORCING MECHANISM FOR SCATTERED SEVERE THUNDERSTORMS
THIS AFTN FROM FRONTIER COUNTY NORTHEAST THROUGH CUSTER AND HOLT
COUNTIES. CONFIDENCE IS ON THE LOW SIDE WITH THIS AS NEITHER THE
HRRR OR RAP MODELS SHOW MUCH FORMING THROUGH 23Z. ALSO...ISOLATED
TSTMS MAY FORM ACROSS WRN NEB LATE THIS AFTERNOON OR THIS EVENING.
THE MOST SIGNIFICANT CONVECTION IS EXPECTED TO FORM LATE TONIGHT
WITH STORMS DEVELOPING ACROSS THE CNTL HIGH PLAINS...BETWEEN 03Z-
06Z AND SPINNING SOUTH AND EAST THROUGH WRN AND NCNTL NEB THROUGH
12Z THURSDAY. NOTE THAT THE NAM SHOWS TWO ROUNDS OF STORMS RIPPING
THROUGH THE FCST AREA AND THIS SEEMS CREDIBLE GIVEN THE VERY ACTIVE
WEATHER PATTERN UNDERWAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
354 AM CDT WED JUL 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CDT WED JUL 31 2013
TODAY AND TONIGHT...HIGH PRESSURE HAS BUILT INTO SCNTL NEB IN WAKE
OF LAST NIGHTS CRUSHING TSTM EVENT. ALL INDICATIONS ARE THE
ATMOSPHERE WILL REMAIN NEARLY QUIET THIS AFTERNOON AND THIS EVENING.
THERE IS PERHAPS THE POTENTIAL FOR DESTABILIZATION THIS AFTN ACROSS
THE CNTL HIGH PLAINS. ISOLATED STORMS COULD DEVELOP ACROSS WRN NEB
WHICH WOULD MOVE EAST AND DISSIPATE IN THE EVENING ACROSS NCNTL NEB.
THERE IS ALSO THE POTENTIAL FOR DESTABILIZATION ACROSS SWRN AND
SCNTL NEB THIS AFTN AND THIS EVENING NORTH OF A SFC FRONT CURRENTLY
LOCATED ACROSS KS AND NERN COLORADO. SPC HAS OUTLOOKED FRONTIER
COUNTY NORTHEAST THROUGH CUSTER AND HOLT COUNTIES IN THEIR DAY 1
OUTLOOK FOR SEVERE TSTM DEVELOPMENT.
FOR THIS MORNING...A CLUSTER OF SHOWERS AND TSTMS ACROSS SWRN SD
COULD SWEEP EAST AND SOUTHEAST THROUGH PARTS OF NWRN AND NCNTL NEB.
THIS IS HIGHLY SPECULATIVE GIVEN THE MODEL DYNAMIC ADJUSTMENT
PROCESS DURING THE FIRST 12 HRS. THE RAP AND HRRR HAVE THEIR OWN
IDEAS. THE RAP SHOWS SCATTERED STORM COVERAGE ACROSS NCNTL NEB WHILE
THE HRRR IS SLOWER AND FARTHER EAST JUST BRUSHING HOLT AND BOYD
COUNTIES. THE FCST IS FOR ISOLATED SHRA/TSTM COVERAGE GIVEN CURRENT
RADAR TRENDS.
TEMPERATURES TODAY ARE ON THE COOL SIDE OF AN ENVELOP OF MID 70S TO
NEAR 90. A BLEND OF MODEL DATA PLUS BIAS CORRECTION YIELDED LOW TO
UPPER 80S FOR HIGHS UNDER SCATTERED AND BROKEN CLOUD COVER.
LASTLY...THE MODELS CONTINUE TO ADVERTISE A LATE NIGHT MCS DROPPING
THROUGH NWRN NEB AROUND 06Z AND THEN PEDDLING EAST AND SOUTHEAST
THROUGH MUCH OF NCNTL NEB BETWEEN 06Z AND 12Z. THE 06Z NAM SHOWS
MODEST ELEVATED CAP AROUND 1000 J/KG AND AN MCS DROPPING MORE SOUTH
THROUGH SCNTL NEB BY 12Z. GIVEN THE TRACK OF THE STORMS TUESDAY
EVENING THIS SOLN HAS SOME CREDIBILITY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 349 AM CDT WED JUL 31 2013
ACTIVE WEATHER TO CONTINUE THROUGH THE PERIOD. A WARM FRONT WILL
EXTEND WEST TO EAST ACROSS THE AREA THURSDAY AND BE THE FOCUS FOR
TSTM DEVELOPMENT. CONTINUED NORTHWEST FLOW ALOFT WILL COMBINE WITH
EAST TO SOUTHEAST WINDS AT THE SFC...PRODUCING FAVORABLE SHEAR FOR
SUPERCELL TSTMS WITH LARGE HAIL AND DAMAGING WIND POTENTIAL. WILL
ALSO HAVE TO WATCH FOR HEAVY RAIN/FLOODING POTENTIAL...AS SOME AREAS
HAVE RECEIVED WELL OVER TWO INCHES OF RAIN THE LAST FEW DAYS.
VALENTINE FOR INSTANCE HAD OVER TWO INCHES OF RAIN JUST LAST
NIGHT.
THE AFOREMENTIONED FRONT WILL REMAIN IN THE AREA FRIDAY THROUGH THE
UPCOMING WEEKEND...AND CONTINUE TO BE THE FOCUS FOR AT LEAST
SCATTERED TSTM DEVELOPMENT. RICH MOISTURE...SHEAR...AND
INSTABILITY...WILL CONTINUE TO BRING THE THREAT FOR A FEW SEVERE
STORMS AS WELL AS LOCALIZED HEAVY RAIN.
BY EARLY NEXT WEEK...HIGH PRESSURE WILL TRY TO NUDGE SOUTH INTO THE
AREA FROM THE NORTHERN PLAINS/CANADA. THIS MAY FORCE THE RICHER
MOISTURE SOUTH INTO KANSAS AND OKLAHOMA...BUT STILLS APPEARS TO BE
ENOUGH MOISTURE IN THE AREA TO CONTINUE SOME SLIGHT AND LOW END
CHANCES FOR TSTM ACTIVITY.
TEMPERATURE WISE...WITH THE FRONT REMAINING IN THE AREA...ALONG WITH
CLOUDS AND PRECIPITATION FROM TIME TO TIME...HIGHS WILL REMAIN
GENERALLY IN THE 80S. OVERNIGHT LOWS WILL BE MILD WITH THE INCREASED
MOISTURE CONTENT IN THE AIR...WITH MOST LOCALS REMAINING IN THE 60S
AT NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1240 AM CDT WED JUL 31 2013
THE HRRR AND RAP MODELS SHOW THE STORMS ACROSS WRN SD SWEEPING
EAST SOUTHEAST THROUGH KVTN AROUND 10Z AND INTO NCNTL NEB THROUGH
12Z. IF THE HRRR IS CORRECT THE STORMS COULD TAKE A MORE SOUTHERLY
TACK AND AFFECT KLBF AROUND 12Z. CURRENT RADAR TRENDS CERTAINLY
SUPPORT A WEAK STORM MOVING THROUGH THE KVTN AREA. THE RAP MODEL
ALSO SHOWS A PERIOD OF MVFR ACROSS NRN NEB THIS MORNING WHICH
SHOULD MIX OUT BY LATE MORNING.
FOR THIS AFTN AND THIS EVENING...THE NAM WOULD SUGGEST ISOLATED TO
SCATTERED TSTM ACTIVITY DEVELOPING ACROSS WRN NEB LATE THIS
AFTERNOON WHICH WOULD MOVE EAST INTO NCNTL NEB DURING THE EVENING
AND WEAKEN.
GIVEN THE VERY VOLITILE ATMOSPHERE IN PLACE...SOME STORMS COULD BE
STRONG OR SEVERE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1253 AM CDT WED JUL 31 2013
.UPDATE...
SCATTERED STRONG TO SEVERE THUNDERSTORMS CONTINUE WITH GOOD
INSTABILITY EXTENDING NORTHWEST THROUGH CUSTER...LINCOLN AND
NORTHWEST...WITH SEVERE THUNDERSTORM WATCH NUMBER 452 TO ALSO
INCLUDE LINCOLN COUNTY. ADDITIONAL CONVECTION DEVELOPING INTO THE
FAR NORTHWEST WITH WATCH VALID UNTIL 11 PM CDT.
&&
.PREV DISCUSSION... /ISSUED 629 PM CDT TUE JUL 30 2013/
UPDATE...
ISSUED AT 620 PM CDT TUE JUL 30 2013
SEVERE THUNDERSTORM WATCH NUMBER 452 CONTINUES WITH
CUSTER...GARFIELD ...HOLT AND WHEELER COUNTIES ADDED AS SEVERE
STORMS CONTINUE TO PUSH SOUTHEAST INTO THE NORTH CENTRAL. STORM
REPORTS HAIL UP TO GOLFBALL AND WIND GUSTS TO 70 MPH.
SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT TUE JUL 30 2013
SEVERE THUNDERSTORM WATCH IN PLACE FOR NORTHERN AND WEST CENTRAL
NEBRASKA GENERALLY ALONG AND NORTH OF HIGHWAY 2. ONGOING
THUNDERSTORMS OVER NORTHERN NEBRASKA WILL CARRY EAST INTO NORTH
CENTRAL NEBRASKA OVER NIGHT AS THE FRONT OVER CENTRAL SOUTH DAKOTA
MOVES SOUTH TONIGHT. BUFR SOUNDINGS HINT AT REDEVELOPMENT OF FOG
OVER SOUTHWEST NEBRASKA EARLY WEDNESDAY MORNING. HAVE LOWERED
TEMPERATURES ACROSS WESTERN NEBRASKA TONIGHT EXCEPT OVER SOUTHWEST
AND NORTH CENTRAL WHERE CLOUDS AND FOG SHOULD KEEP TEMPERATURES UP.
FOG TO BURN OFF EARLY ON WEDNESDAY BUT COOLER AIR IN BEHIND FRONT
WILL KEEP MUCH OF NORTH CENTRAL NEBRASKA IN COOLER TEMPERATURES.
TEMPERATURES IN LOW 80S NORTH AND UPPER 80S EXTREME SOUTHWEST.
SLIGHT CHANCE OF THUNDERSTORMS IN THE ONEILL AREA THROUGH THE
MORNING AND THEN SHIFT TO SOUTHWEST AND SOUTH CENTRAL LATE AFTERNOON
WITH A WEAK LOW DEVELOPING ALONG THE FRONT OVER SOUTHWEST NEBRASKA.
LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM CDT TUE JUL 30 2013
A DISTURBANCE WILL MOVE INTO THE FORECAST AREA WEDNESDAY NIGHT. HAVE
INCREASED POPS TO 50 PERCENT PORTIONS OF SHERIDAN AND WRN CHERRY
COUNTY AFTER MIDNIGHT. THE NAM MODEL HAS BEEN CONSISTENT SHOWING
THIS AND THE 12Z GFS IS COMING IN LINE. THIS DISTURBANCE WILL SLOWLY
MOVE SOUTHEAST THURSDAY INTO THURSDAY NIGHT. HAVE INCREASED INTO
LIKELY POPS CENTRAL AND EAST. A WEAK COLD FRONT WEDNESDAY NIGHT WILL
SLOWLY LIFT NORTHEAST AS A WARM FRONT THROUGH THURSDAY
NIGHT...FURTHER AIDING IN LIFT. THERE IS THE POTENTIAL FOR SEVERE
STORMS THURSDAY INTO THURSDAY NIGHT WITH FAVORABLE DEEP LAYER SHEAR
AND INSTABILITY. HIGHS THURSDAY MAINLY IN THE MID 80S.
MAINLY A SLIGHT CHANCE FRIDAY WITH INCREASING 30-40 POPS FRIDAY
NIGHT. CREST OF UPPER RIDGE AXIS TO BE ACROSS NEBR PANHANDLE AND ERN
CO. AFTERNOON STORM DEVELOPMENT TO PUSH EAST IN THE EVENING AND
OVERNIGHT. SIMILAR SETUP THROUGH SATURDAY NIGHT. A NORTHWEST FLOW
SETS UP SUNDAY THROUGH TUESDAY WITH A 20 TO 30 PERCENT CHANCE DAILY.
HIGHS MAINLY IN THE MID 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1240 AM CDT WED JUL 31 2013
THE HRRR AND RAP MODELS SHOW THE STORMS ACROSS WRN SD SWEEPING
EAST SOUTHEAST THROUGH KVTN AROUND 10Z AND INTO NCNTL NEB THROUGH
12Z. IF THE HRRR IS CORRECT THE STORMS COULD TAKE A MORE SOUTHERLY
TACK AND AFFECT KLBF AROUND 12Z. CURRENT RADAR TRENDS CERTAINLY
SUPPORT A WEAK STORM MOVING THROUGH THE KVTN AREA. THE RAP MODEL
ALSO SHOWS A PERIOD OF MVFR ACROSS NRN NEB THIS MORNING WHICH
SHOULD MIX OUT BY LATE MORNING.
FOR THIS AFTN AND THIS EVENING...THE NAM WOULD SUGGEST ISOLATED TO
SCATTERED TSTM ACTIVITY DEVELOPING ACROSS WRN NEB LATE THIS
AFTERNOON WHICH WOULD MOVE EAST INTO NCNTL NEB DURING THE EVENING
AND WEAKEN.
GIVEN THE VERY VOLITILE ATMOSPHERE IN PLACE...SOME STORMS COULD BE
STRONG OR SEVERE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...TLK
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1237 AM CDT WED JUL 31 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 246 PM CDT TUE JUL 30 2013
MAIN UPPER LEVEL SCENARIO INCLUDES A PERSISTENT SUBTROPICAL RIDGE
OVER THE SOUTHERN UNITED STATES. SPLIT JET WITHIN QUASI-ZONAL FLOW
IN THE NORTH CONTAINS A SHORTWAVE TROUGH SKIRTING ACROSS THE
NORTHERN PLAINS WHICH SHOULD DEVELOP A LONG ADVERTISED MCS OVER
SOUTH DAKOTA THAT SHOULD MAKE ITS WAY SOUTHEAST...AND COULD JUST
SWIPE THE CWA IN THE NORTH BY LATE TONIGHT. THERE COULD BE ENOUGH
SHEAR TO GET SOME STRONG TO SEVERE WEATHER FROM THE REMNANTS OF THE
EXPECTED MCS. CONVERGENCE ALONG AN APPROACHING COLD FRONT WILL ALSO
INCREASE PRECIPITATION AND SEVERE THUNDERSTORM CHANCES. AS A SIDE
NOTE...SKY COVER IS DIFFICULT TO FORECAST FOR THIS EVENING...AND I
HAVE CURBED THE ENTHUSIASM OF MOST MODELS FOR CLEARING...AS EVEN
THE HRRR HAS SHOWN TOO MUCH OPTIMISM FOR THE CLEARING.
ALSO...MODELS HAVE CONTINUED TO ADVERTISE A FAIRLY STRONG SIGNAL FOR
FOG AND HAVE BEEN PRETTY CONSISTENT AS STRATUS IS FORECAST TO
LOWER UNTIL WE GET DENSE FOG IN OUR EAST. CONFIDENCE IS HIGHER WITH
THE RECENT CONSISTENCY...AND A FAIRLY STRONG SIGNAL IN THE
EASTERN THIRD OF THE CWA PERSISTS...PROMPTING ME TO ISSUE A DENS
FOG ADVISORY FOR LATE TONIGHT INTO WEDNESDAY MORNING.
A COLD FRONT WILL MAKE ITS WAY ACROSS THE CWA FOR WEDNESDAY AND WILL
BE THE FOCUS FOR MORE POSSIBLE SEVERE WEATHER. DEWPOINTS ARE
EXPECTED TO POOL NEAR THE BOUNDARY WITH INCREASED INSTABILITY ALONG
THE FRONT...AND CONTINUED LOW-LEVEL CONVERGENCE. BULK SHEAR WILL
ALSO BE SUFFICIENT ENOUGH FOR SEVERE WEATHER...EVEN IF THERE ARE
LIMITED BREAKS IN SKY COVER. THIS COULD WIND UP BEING A POTENTIALLY
INTERESTING DAY DEPENDING ON THE TIMING OF THE COLD FRONT. KEPT A
CHANCE OF PRECIPITATION NEAR THE FRONT...SIMILAR TO THE PREVIOUS
FORECAST.
BASED TEMPERATURES AND DEWPOINTS ON RECENT MODEL PERFORMANCE AND NOT
MUCH HAS CHANGED FOR THESE FIELDS COMPARED TO THE PREVIOUS
FORECAST...EXCEPT PERHAPS HIGHER DEWPOINTS NEAR THE PROJECTED TIMING
AND PLACEMENT OF THE COLD FRONT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 246 PM CDT TUE JUL 30 2013
GUIDANCE SUGGESTS NORTHWESTERLY MID TO UPPER LEVEL FLOW WILL PERSIST
OVER THE CENTRAL PLAINS THROUGH MUCH OF THE LONG TERM FORECAST
PERIOD. WITH MULTIPLE MID LEVEL PERTURBATIONS PERHAPS MOVING OVER
THE AREA WITHIN THE MEAN MID LEVEL FLOW...POPS REMAIN LITTERED
THROUGHOUT MOST ALL OF THE LONG TERM FORECAST PERIOD. OUT OF ALL THE
LONG TERM FORECAST PERIODS...THE HIGHEST CONFIDENCE WITH RESPECT TO
POPS EXISTS DURING THURSDAY AND THURSDAY NIGHT. THESE ARE TIME
PERIODS IN WHICH GUIDANCE SUGGESTS LOW LEVEL THERMAL ADVECTION AND
RESULTANT ISENTROPIC UPGLIDE AND SATURATION...PRIMARILY ALONG THE
315-320K SURFACES...WILL PERSIST. THIS THERMAL ADVECTION...WORKING IN
CONCERT WITH OMEGA FROM MID LEVEL PERTURBATIONS PUSHING
OVERHEAD...SHOULD BE STRONG ENOUGH TO PROMOTE PRECIPITATION
PRODUCTION ACROSS MUCH OF OUR AREA. TAKING A AVERAGE OF THE
NAM...OPERATIONAL GFS...EC...AND SREF-MEAN PROVIDES BETWEEN A
QUARTER INCH AND A HALF INCH OF RAIN ACROSS MUCH OF OUR CWA DURING
THE DAY THURSDAY...AND MUCH OF THE SAME ACROSS OUR EAST THURSDAY
NIGHT. WENT AHEAD AND INCREASED POPS ACROSS MUCH OF OUR CWA THURSDAY
INTO THURSDAY NIGHT AS A RESULT. POPS ALSO CONTINUE ACROSS OUR AREA
FOR THE MOST PART HEADING INTO FRIDAY BEFORE THE PRIMARY AXIS OF
THERMAL ADVECTION FINALLY EXITS THE AREA TO THE EAST. AS MENTIONED
ALREADY...THE POTENTIAL FOR MID LEVEL PERTURBATIONS MOVING OVER THE
AREA SUGGESTS POPS REMAIN WARRANTED ACROSS OUR AREA THROUGH THE
REMAINDER OF THE EXTENDED FORECAST PERIOD. ALLBLEND PROVIDED A
VARIETY OF POPS TO OUR AREA EACH DAY...GENERALLY IN THE 20-40%
RANGE...AND GIVEN THE LOW PROBABILITY OF IMPROVING THE FORECAST
THESE POPS WERE LEFT UNCHANGED FOR THE MOST PART.
INCREASING LOW LEVEL RETURN FLOW AND RESULTANT MOISTURE FLUX INTO
THE AREA SHOULD HELP PROMOTE RESPECTABLE VALUES OF POTENTIAL
INSTABILITY ON THURSDAY...WITH GUIDANCE FROM THE NAM...OPERATIONAL
GFS...AND EC SUGGESTING MUCAPE VALUES RANGING BETWEEN 1500 AND
3500J/KG ACROSS OUR CWA. DEEP LAYER BULK SHEAR VALUES OF 35-45KTS
ARE ALSO FORECAST ACROSS THE AREA ON THURSDAY. THERE IS A CONCERN
THAT EXPANSIVE CLOUD COVER WILL KEEP LOW LEVEL TEMPERATURES ON THE
COOL SIDE WHICH WOULD HELP PRESERVE A LOW LEVEL CAPPING
INVERSION...WHICH WOULD OBVIOUSLY INHIBIT STRONG/DEEP CONVECTION
FROM BEING REALIZED. THAT BEING SAID...IF NEAR-SURFACE BASED
CONVECTION CAN BE REALIZED THURSDAY...THEN CERTAINLY SEVERE WEATHER
WILL BE POSSIBLE AND WILL INTRODUCE SUCH WORDING TO THE HWO. BEYOND
THURSDAY...GUIDANCE SUGGESTS MUCAPE VALUES IN EXCESS OF 2000J/KG
COULD BE REALIZED MOST ANY DAY...BUT AS ALREADY MENTIONED CONFIDENCE
ON WHEN AND WHERE CONVECTION WILL BE REALIZED IS VERY LOW AND AS A
RESULT...WILL MAINTAIN VAGUE SEVERE WEATHER WORDING IN THE HWO FOR
FRIDAY AND BEYOND.
&&
.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1230 AM CDT WED JUL 31 2013
LOTS OF UNCERTAINTY OVER THE NEXT FEW HOURS AS MODELS ARE HAVING A
TOUGH TIME HANDLING CURRENT CONVECTIVE TRENDS. THAT SAID...WENT
AHEAD AN TRIED TO TIME THE AREA OF SHOWERS AND THUNDERSTORMS NEAR
THEDFORD...AND IF THEY HOLD TOGETHER...THEY SHOULD BE REACHING
KGRI AROUND 08Z. AFTER THIS AREA OF SHOWERS PASS...EXPECT SOME
LIGHT BR DEVELOPMENT JUST BEFORE SUNRISE...AND KEPT MVFR VSBYS AND
CIGS TO ACCOUNT FOR POTENTIAL FOG DEVELOPMENT AS WINDS WILL BE
LIGHT AND SOILS REMAIN FAIRLY SATURATED. THEN AS WE TRANSITION IN
TO THE DAYTIME HOURS WEDNESDAY...EXPECT AN APPROACHING FRONT TO
PROVIDE A TRIGGER FOR ADDITIONAL CONVECTIVE DEVELOPMENT...AND KEPT
A VCTS OR VCSH FROM 31/18Z ONWARD...AS THIS FRONT IS EXPECTED TO
STALL OVER THE HEART OF THE FORECAST AREA THROUGH THE EVENING AND
OVERNIGHT HOURS. OTHER THAN POTENTIAL OUTFLOW WINDS...SYNOPTIC
SCALE FLOW THROUGH THE PERIOD WILL BE LIGHT AND SOMEWHAT VARIABLE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...DENSE FOG ADVISORY FROM 4 AM TO 10 AM CDT THIS MORNING FOR
NEZ041-048-049-063-064-076-077-086-087.
KS...DENSE FOG ADVISORY FROM 4 AM TO 10 AM CDT THIS MORNING FOR
KSZ007-019.
&&
$$
SHORT TERM...HEINLEIN
LONG TERM...BRYANT
AVIATION...SAR
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1006 PM EDT THU AUG 1 2013
.SYNOPSIS...
SCATTERED SHOWERS WILL COME TO AN END BY EARLY EVENING AS A COLD
FRONT MOVES EAST OF THE REGION. DRY CONDITIONS WILL RETURN TO THE
AREA TONIGHT WITH PATCHY RIVER VALLEY FOG DEVELOPMENT LIKELY BY
MORNING. UNSETTLED CONDITIONS WITH SCATTERED SHOWERS WILL THEN
DOMINATE THROUGH THE UPCOMING WEEKEND AS A SERIES OF UPPER-LEVEL
DISTURBANCES MOVE OVER THE REGION.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
10 PM UPDATE...
LINE OF SHOWERS AND ISOLD TSTMS CONT TO PUSH THRU CWA AT THIS
TIME, ALBEIT A LITTLE SLOWER THAN PREVIOUSLY THOUGHT. THUS HV
SLOWED DOWN PROGRESSION AND HV LKLY POPS IN ACRS SE ZONES THRU AT
LEAST MIDNIGHT. 3-HR QPF AMNTS ARE GNRLY IN THE 1-1.5 INCH RANGE
IN CERTAIN LOCATIONS.
CDFNT WL NOT CLEAR CWA UNTIL AFT 06Z WITH PARTIALLY CLRNG SKIES IN
ITS WAKE. THIS WL LKLY RESULT IN RVR VLYS FOG TWD MRNG AS VRY
LITTLE DRY SFC DWPTS ARE PRESENT WITH FROPA. TEMPS HV DROPPED
RAPIDLY ACRS NRN ZONES BTWN 00Z AND 01Z AND AND HV ADJUST HRLY
GRIDS TO ACCNT FOR THIS. HWVR, NO CHGS FORESEEN TO MIN TEMP GRIDS
FOR TONIGHT.
UPDATES HV BEEN SENT EVERY HR TO ACCNT FOR SLOW MVMNT OF PCPN. AND
THIS WL CONTINUE TO BE THE TREND OVRNGT.
PREV DISCOS BLO...
630 PM UPDATE...
CDFNT HAS MADE IT TO AN OLD FORGE TO BINGHAMTON TO TOWANDA LINE
AS OF 2230Z. THIS IS BRINGING A THIN LINE OF SHOWERS AND EMBEDDED
TSTMS TO THIS AREA, HEADED EAST. AT ANY ONE LOCATION, RAIN SHOULD
NOT LAST MUCH MORE THAN ABOUT 20 MINUTES AS IT IS MOVING AT A
FAIRLY STEADY CLIP. RAINFALL AMOUNTS OVR THE PAST HOUR HV BEEN
LESS THAN 0.50 INCHES AS THIS LINE MVS THRU.
HV UPDATED POPS GRIDS TO TIME THIS LINE THRU THE CWA AND EXPECT
THIS MAIN LINE TO CLR SULLIVAN CNTY NY AND PIKE CNTY PA AROUND
03Z. DRIER AIR ALOFT WL MV IN QUICKLY FOLLOWING FROPA AND MAY
ALLOW PATCHY RVR VLY FOG TO FORM TWD MRNG.
WL UPDATE T/TD VALUES THIS EVNG AS THEY START TO DROP, OTHERWISE
NO OTHER CHGS NEEDED AT THIS TIME.
4 PM UPDATE...
COLD FRONT CURRENTLY WORKING THROUGH THE AREA WITH SCATTERED CONVECTION
NOW DEVELOPING ACROSS THE NORTHERN FINGER LAKES REGION OF CENTRAL
NY. OUT AHEAD OF THIS FEATURE...SCATTERED SHWRS PREVAILING FROM
THE LWR WYOMING VLY NORTH THROUGH THE POCONOS AND CATSKILLS. QUICK
LOOK AT LATEST SPC MESO GRAPHICS SHOWS WEAK INSTABILITY EXTENDING
NORTH FROM FROM THE CENTRAL PA THIS AFTERNOON WHICH OBVIOUSLY IS
HELPING WITH THE CURRENT CONVECTIVE DEVELOPMENT ACROSS PORTIONS OF
OUR FORECAST REGION. FORTUNATELY THROUGH...STRONGEST WIND FIELDS
ASSOCIATED WITH UPPER TROUGH DIVING SOUTHEAST INTO THE
CENTRAL/EASTERN LAKES REMAINS DISPLACED WELL TO OUR NORTH THIS
AFTERNOON. THUS...ONGOING ACTIVITY SHOULD POSE VERY LITTLE IN THE
WAY OF AN ORGANIZED SEVERE WX THREAT. IN ANY EVENT...HAVE
INCREASED POPS TO CATEGORICAL FOR THE NEXT FEW HRS ACROSS THE
NORTHERN CWA AS BOUNDARY CONTINUES MOVING EAST WITH TIME.
AFTER FRONT CLEARS THE AREA...EXPECT SKIES TO CLEAR ALOFT FOR
AWHILE...WHICH WILL LIKELY SET THE STAGE FOR ANOTHER ROUND OF
EARLY MORNING RIVER VALLEY FOG FOR AREAS SOUTH OF THE LAKE PLAIN.
OVERNIGHT LOWS WILL ALL INTO THE LOWER TO MIDDLE 50S AS SLIGHTLY
COOLER CONTINUES TO MOVE INTO THE REGION OVERNIGHT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FCST MOVING INTO THE UPCOMING WEEKEND REMAINS LOW CONFIDENCE AT
BEST AS MODELS CONTINUE TO OFFER MIXED SIGNALS WITH RESPECT TO
BOTH PRECIP TIMING AND INTENSITY. ALTHOUGH PERIOD STARTS OUT WITH
AVERAGE CONFIDENCE ON FRI...MODELS QUICKLY DIVERGE BY FRI NGT.
THAT SAID...LOOK FOR SHWRS TO REDEVELOP ACROSS THE AREA BY LATE
FRI MORNING/EARLY AFTERNOON AS THE FIRST IN A SERIES OF UPPER
SHORTWAVES DIVES SOUTHEAST TOWARDS OUR AREA IN DEVELOPING
NORTHWEST FLOW ALOFT. FOR NOW...CURRENT THINKING REMAINS THE SAME
IN THAT THE MOST LIKELY AREAS TO GET ORGANIZED SHWR ACTIVITY
WILL REMAIN ALONG AND NORTH OF THE STATE LINE AS UPPER FORCING
FROM A SOUTHEASTWARD DIVING UPPER JET STREAK (130+ KTS) CREATES
DECENT UPPER DIVERGENCE OVER THE AREA. FOR NOW...HAVE CAPPED POPS
IN THE SCT CATEGORY FOR MUCH OF THE CNY ZONES...WITH ISO-SCT
FURTHER SOUTH INTO NORTHEAST PA. BY NO MEANS SHOULD THE DAY BE A
WASHOUT AS ACTIVITY WILL LIKELY REMAIN FAIRLY SCATTERED IN NATURE.
FCST BECOMES MUCH MORE MURKY BY FRI NIGHT AS THE WRF SHOWS A SFC
LOW DRIVING EAST FROM THE CENTRAL GREAT LAKES AS THE NEXT UPPER
SHORTWAVE DIVES SOUTHEAST TOWARDS OUR AREA. AS THIS
OCCURS...SOUTHERLY FLOW WILL INCREASE WHICH WILL HELP LIFT A WARM
FRONT NORTH TOWARDS THE REGION. UPPER FORCING FROM DECENT UPPER
DIVERGENCE ALOFT COMBINED WITH THE APPROACHING SHORTWAVE AND
ISENTROPIC ASCENT ALONG AND NORTH OF THE FRONT LENDS US TO BELIEVE
ANOTHER ROUND OF SHWRS WILL BE POSSIBLE FRI NIGHT/EARLY SAT. IT
SHOULD BE STATED THAT THE GFS DOES SHOW A SHORTWAVE MOVING EAST
WITH TIME FROM THE CENTRAL LAKES...HOWEVER IT REMAINS FURTHER
NORTH WITH MAX PVA FCST OVER NORTHERN NY/SOUTHERN CANADA. JUST
ARRIVING 12Z ECMWF WHICH OFFERS SOME SUPPORT TO THE MORE AGRESSIVE
WRF SOLUTION THUS WILL MAINTAIN A SCT MENTION ACROSS THE FCST AREA
FRI NIGHT.
MOVING ONTO SATURDAY...EARLY MORNING ACTIVITY WILL LIKELY BE
EXITING STAGE RIGHT AT THE BEGINNING OF THE PERIOD...WITH ANOTHER
SHORTWAVE DIVING SOUTHEAST ON ITS HEELS. WITH EARLY MORNING SHWR
ACTIVITY EXPECTED ACROSS CNY...CURRENT MODEL TRENDS SUGGEST
OUTFLOW FROM EARLY MORNING ACTIVITY WILL LIKELY SUPPRESS THE FRONT
FURTHER SOUTH THROUGH THE AM HRS. WITH THIS BEING THE
CASE...HIGHEST SHWR POTENTIAL WILL LIKELY BE SOUTH OF THE STATE
LINE ON SATURDAY AS LINGERING FRONT INTERACTS WITH ARRIVING
SHORTWAVE ENERGY DURING THE AFTERNOON.
BY SATURDAY NIGHT...HIGH PRESSURE ACROSS THE UPPER MISS RVR VLY
WILL SLOWLY ADVANCE EAST WITH TIME WHICH COMBINED WITH THE PASSAGE
OF ANOTHER SHORTWAVE DURING THE OVERNIGHT HRS...SHOULD PROPEL THE
FRONT EVEN FURTHER SOUTH WITH TIME. THAT SAID HOWEVER...AREA WILL
REMAIN IN CYCLONIC FLOW ALOFT THROUGH THE DAY ON SUNDAY WITH
ADDITIONAL SHWR ACTIVITY LIKELY BY LATE MORNING AND AFTERNOON.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SET UP FOR THE XTNDD PD IS A LONG WV TROF OVER THE ERN US. DFRNCS EXIST
IN THE LONG TERM MODELS OVER THE DEPTH AND PERSISTENCE OF THE TROF
WITH THE GFS BEING DEEPER AND BROADER WHILE THE EURO HAS A SHARPER
TROF THAT BEGINS TO LIFT LATE IN THE PD. OTR DFRNCS INCLUDE THE
TYPICAL TIMING ISSUES WITH SHRT WVS DROPPING THRU THE TROF. LTL
MONEY TO BE MADE IN TRYING TO TIME THE WVS SO THE LATTER HALF OF
THE PD WILL SIMPLY INCLUDE CHANCE POPS WITH SHWRS WITH ISLTD CONV
PSBL. TEMPS THRU THE PD WILL CONT TO BE BLO SEASONAL NORMS...ESP
IN THE AFTN. NGT TIME TEMPS WILL BE NEARER TO NRML.
FOR THE PD...GNRLY FLWD HPC GUID AS WITH THE UNCERTAINTY THERE
WERE ONLY MINOR DFRNCS WITH THE GFS MOS...MAINLY BEING THE GFS WAS
SLGTLY WRMR.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
COLD FRONT WILL PUSH SHOWERS THROUGH AVP OVER THE NEXT 2 HOURS,
BRINGING A BRIEF PERIOD OF MVFR VISIBILITIES AND CEILINGS IN
MODERATE RAIN.
MOS OUTPUT IS FORECASTING A COMBINATION OF STRATUS FORMATION AND
DENSE VALLEY FOG FOR FRIDAY MORNING, WHICH IS QUITE A RARE
COMBINATION. LATEST RAP INSTEAD INDICATES A FEW TO SCT 6000 FOOT
DECK, WITH LIGHT FOG FORMING BETWEEN 6Z AND 12Z.
THIS LATTER FORECAST SEEMS MORE REALISTIC, AND IS WHAT WE HAVE
BASED OUR OVERNIGHT TAF PACKAGE ON.
FRIDAY AFTERNOON WILL BE QUIET, WITH WEST WINDS AROUND 10 KNOTS
AND VFR CONDITIONS PREVAILING. IFR FOG IS POSSIBLE IN THE VALLEYS
SATURDAY MORNING.
SAT THRU TUE...GNRL VFR CONDS. CHANCE MVFR IN MAINLY AFTN
SHRA/TSRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG/PVN
SHORT TERM...CMG
LONG TERM...DGM
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
738 PM EDT THU AUG 1 2013
.SYNOPSIS...
SCATTERED SHOWERS WILL COME TO AN END BY EARLY EVENING AS A COLD
FRONT MOVES EAST OF THE REGION. DRY CONDITIONS WILL RETURN TO THE
AREA TONIGHT WITH PATCHY RIVER VALLEY FOG DEVELOPMENT LIKELY BY
MORNING. UNSETTLED CONDITIONS WITH SCATTERED SHOWERS WILL THEN
DOMINATE THROUGH THE UPCOMING WEEKEND AS A SERIES OF UPPER-LEVEL
DISTURBANCES MOVE OVER THE REGION.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
630 PM UPDATE...
CDFNT HAS MADE IT TO AN OLD FORGE TO BINGHAMTON TO TOWANDA LINE AS
OF 2230Z. THIS IS BRINGING A THIN LINE OF SHOWERS AND EMBEDDED
TSTMS TO THIS AREA, HEADED EAST. AT ANY ONE LOCATION, RAIN SHOULD
NOT LAST MUCH MORE THAN ABOUT 20 MINUTES AS IT IS MOVING AT A
FAIRLY STEADY CLIP. RAINFALL AMOUNTS OVR THE PAST HOUR HV BEEN
LESS THAN 0.50 INCHES AS THIS LINE MVS THRU.
HV UPDATED POPS GRIDS TO TIME THIS LINE THRU THE CWA AND EXPECT
THIS MAIN LINE TO CLR SULLIVAN CNTY NY AND PIKE CNTY PA AROUND
03Z. DRIER AIR ALOFT WL MV IN QUICKLY FOLLOWING FROPA AND MAY
ALLOW PATCHY RVR VLY FOG TO FORM TWD MRNG.
WL UPDATE T/TD VALUES THIS EVNG AS THEY START TO DROP, OTHERWISE
NO OTHER CHGS NEEDED AT THIS TIME.
PREV DISCO BLO...
COLD FRONT CURRENTLY WORKING THROUGH THE AREA WITH SCATTERED
CONVECTION NOW DEVELOPING ACROSS THE NORTHERN FINGER LAKES REGION
OF CENTRAL NY. OUT AHEAD OF THIS FEATURE...SCATTERED SHWRS
PREVAILING FROM THE LWR WYOMING VLY NORTH THROUGH THE POCONOS
AND CATSKILLS. QUICK LOOK AT LATEST SPC MESO GRAPHICS SHOWS WEAK
INSTABILITY EXTENDING NORTH FROM FROM THE CENTRAL PA THIS
AFTERNOON WHICH OBVIOUSLY IS HELPING WITH THE CURRENT CONVECTIVE
DEVELOPMENT ACROSS PORTIONS OF OUR FORECAST REGION. FORTUNATELY
THROUGH...STRONGEST WIND FIELDS ASSOCIATED WITH UPPER TROUGH
DIVING SOUTHEAST INTO THE CENTRAL/EASTERN LAKES REMAINS DISPLACED
WELL TO OUR NORTH THIS AFTERNOON. THUS...ONGOING ACTIVITY SHOULD
POSE VERY LITTLE IN THE WAY OF AN ORGANIZED SEVERE WX THREAT. IN
ANY EVENT...HAVE INCREASED POPS TO CATEGORICAL FOR THE NEXT FEW
HRS ACROSS THE NORTHERN CWA AS BOUNDARY CONTINUES MOVING EAST WITH
TIME.
AFTER FRONT CLEARS THE AREA...EXPECT SKIES TO CLEAR ALOFT FOR
AWHILE...WHICH WILL LIKELY SET THE STAGE FOR ANOTHER ROUND OF
EARLY MORNING RIVER VALLEY FOG FOR AREAS SOUTH OF THE LAKE PLAIN.
OVERNIGHT LOWS WILL ALL INTO THE LOWER TO MIDDLE 50S AS SLIGHTLY
COOLER CONTINUES TO MOVE INTO THE REGION OVERNIGHT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FCST MOVING INTO THE UPCOMING WEEKEND REMAINS LOW CONFIDENCE AT
BEST AS MODELS CONTINUE TO OFFER MIXED SIGNALS WITH RESPECT TO
BOTH PRECIP TIMING AND INTENSITY. ALTHOUGH PERIOD STARTS OUT WITH
AVERAGE CONFIDENCE ON FRI...MODELS QUICKLY DIVERGE BY FRI NGT.
THAT SAID...LOOK FOR SHWRS TO REDEVELOP ACROSS THE AREA BY LATE
FRI MORNING/EARLY AFTERNOON AS THE FIRST IN A SERIES OF UPPER
SHORTWAVES DIVES SOUTHEAST TOWARDS OUR AREA IN DEVELOPING
NORTHWEST FLOW ALOFT. FOR NOW...CURRENT THINKING REMAINS THE SAME
IN THAT THE MOST LIKELY AREAS TO GET ORGANIZED SHWR ACTIVITY
WILL REMAIN ALONG AND NORTH OF THE STATE LINE AS UPPER FORCING
FROM A SOUTHEASTWARD DIVING UPPER JET STREAK (130+ KTS) CREATES
DECENT UPPER DIVERGENCE OVER THE AREA. FOR NOW...HAVE CAPPED POPS
IN THE SCT CATEGORY FOR MUCH OF THE CNY ZONES...WITH ISO-SCT
FURTHER SOUTH INTO NORTHEAST PA. BY NO MEANS SHOULD THE DAY BE A
WASHOUT AS ACTIVITY WILL LIKELY REMAIN FAIRLY SCATTERED IN NATURE.
FCST BECOMES MUCH MORE MURKY BY FRI NIGHT AS THE WRF SHOWS A SFC
LOW DRIVING EAST FROM THE CENTRAL GREAT LAKES AS THE NEXT UPPER
SHORTWAVE DIVES SOUTHEAST TOWARDS OUR AREA. AS THIS
OCCURS...SOUTHERLY FLOW WILL INCREASE WHICH WILL HELP LIFT A WARM
FRONT NORTH TOWARDS THE REGION. UPPER FORCING FROM DECENT UPPER
DIVERGENCE ALOFT COMBINED WITH THE APPROACHING SHORTWAVE AND
ISENTROPIC ASCENT ALONG AND NORTH OF THE FRONT LENDS US TO BELIEVE
ANOTHER ROUND OF SHWRS WILL BE POSSIBLE FRI NIGHT/EARLY SAT. IT
SHOULD BE STATED THAT THE GFS DOES SHOW A SHORTWAVE MOVING EAST
WITH TIME FROM THE CENTRAL LAKES...HOWEVER IT REMAINS FURTHER
NORTH WITH MAX PVA FCST OVER NORTHERN NY/SOUTHERN CANADA. JUST
ARRIVING 12Z ECMWF WHICH OFFERS SOME SUPPORT TO THE MORE AGRESSIVE
WRF SOLUTION THUS WILL MAINTAIN A SCT MENTION ACROSS THE FCST AREA
FRI NIGHT.
MOVING ONTO SATURDAY...EARLY MORNING ACTIVITY WILL LIKELY BE
EXITING STAGE RIGHT AT THE BEGINNING OF THE PERIOD...WITH ANOTHER
SHORTWAVE DIVING SOUTHEAST ON ITS HEELS. WITH EARLY MORNING SHWR
ACTIVITY EXPECTED ACROSS CNY...CURRENT MODEL TRENDS SUGGEST
OUTFLOW FROM EARLY MORNING ACTIVITY WILL LIKELY SUPPRESS THE FRONT
FURTHER SOUTH THROUGH THE AM HRS. WITH THIS BEING THE
CASE...HIGHEST SHWR POTENTIAL WILL LIKELY BE SOUTH OF THE STATE
LINE ON SATURDAY AS LINGERING FRONT INTERACTS WITH ARRIVING
SHORTWAVE ENERGY DURING THE AFTERNOON.
BY SATURDAY NIGHT...HIGH PRESSURE ACROSS THE UPPER MISS RVR VLY
WILL SLOWLY ADVANCE EAST WITH TIME WHICH COMBINED WITH THE PASSAGE
OF ANOTHER SHORTWAVE DURING THE OVERNIGHT HRS...SHOULD PROPEL THE
FRONT EVEN FURTHER SOUTH WITH TIME. THAT SAID HOWEVER...AREA WILL
REMAIN IN CYCLONIC FLOW ALOFT THROUGH THE DAY ON SUNDAY WITH
ADDITIONAL SHWR ACTIVITY LIKELY BY LATE MORNING AND AFTERNOON.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SET UP FOR THE XTNDD PD IS A LONG WV TROF OVER THE ERN US. DFRNCS EXIST
IN THE LONG TERM MODELS OVER THE DEPTH AND PERSISTENCE OF THE TROF
WITH THE GFS BEING DEEPER AND BROADER WHILE THE EURO HAS A SHARPER
TROF THAT BEGINS TO LIFT LATE IN THE PD. OTR DFRNCS INCLUDE THE
TYPICAL TIMING ISSUES WITH SHRT WVS DROPPING THRU THE TROF. LTL
MONEY TO BE MADE IN TRYING TO TIME THE WVS SO THE LATTER HALF OF
THE PD WILL SIMPLY INCLUDE CHANCE POPS WITH SHWRS WITH ISLTD CONV
PSBL. TEMPS THRU THE PD WILL CONT TO BE BLO SEASONAL NORMS...ESP
IN THE AFTN. NGT TIME TEMPS WILL BE NEARER TO NRML.
FOR THE PD...GNRLY FLWD HPC GUID AS WITH THE UNCERTAINTY THERE
WERE ONLY MINOR DFRNCS WITH THE GFS MOS...MAINLY BEING THE GFS WAS
SLGTLY WRMR.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
COLD FRONT WILL PUSH SHOWERS THROUGH AVP OVER THE NEXT 2 HOURS,
BRINGING A BRIEF PERIOD OF MVFR VISIBILITIES AND CEILINGS IN
MODERATE RAIN.
MOS OUTPUT IS FORECASTING A COMBINATION OF STRATUS FORMATION AND
DENSE VALLEY FOG FOR FRIDAY MORNING, WHICH IS QUITE A RARE
COMBINATION. LATEST RAP INSTEAD INDICATES A FEW TO SCT 6000 FOOT
DECK, WITH LIGHT FOG FORMING BETWEEN 6Z AND 12Z.
THIS LATTER FORECAST SEEMS MORE REALISTIC, AND IS WHAT WE HAVE
BASED OUR OVERNIGHT TAF PACKAGE ON.
FRIDAY AFTERNOON WILL BE QUIET, WITH WEST WINDS AROUND 10 KNOTS
AND VFR CONDITIONS PREVAILING. IFR FOG IS POSSIBLE IN THE VALLEYS
SATURDAY MORNING.
SAT THRU TUE...GNRL VFR CONDS. CHANCE MVFR IN MAINLY AFTN
SHRA/TSRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...CMG
NEAR TERM...CMG/PVN
SHORT TERM...CMG
LONG TERM...DGM
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
214 PM EDT WED JUL 31 2013
.SYNOPSIS...
SHOWERS AND SCATTERED THUNDERSTORMS WILL OVERSPREAD THE REGION
TONIGHT AND THURSDAY AS A COLD FRONT APPROACHES THEN CROSSES THE
REGION. LINGERING MOISTURE AND SOMEWHAT UNSTABLE AIR BEHIND THE
FRONT MAY BRING A FEW MORE SHOWERS ON FRIDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
CLOUDS WILL CONTINUE TO OVERSPREAD THE REGION AND THICKEN THIS
EVENING AS MOISTURE DEEPENS AHEAD OF THE APPROACHING COLD FRONT.
RADARS SHOWING ACTIVITY OVER SOUTHERN ONTARIO BUT THE AIR MASS IS
STILL SO DRY OVER THE REGION THAT IT WILL LIKELY BE A WHILE BEFORE
WE ACTUALLY SEE PCPN REACHING THE GROUND. THAT BEING SAID ONCE THE
RAIN DOES BEGIN THE UPPER DYNAMICS WILL BE SUCH THAT A PERIOD OF
MODERATE RAIN IS LIKELY ACROSS WESTERN NEW YORK BY MORNING AND
ACROSS THE EASTERN SECTIONS DURING THURSDAY MORNING...WITH
RAINFALL TOTALS GENERALLY AROUND A HALF INCH.
A COLD FRONT WILL CROSS THE AREA ON THURSDAY. THE SHOWERS WILL
THUS QUICKLY TAPER OFF FROM WEST TO EAST DURING THE COURSE OF THE
AFTERNOON.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
THE LONGWAVE PATTERN THAT WE WILL BE IN DURING THE NEXT WEEK TO TEN
DAYS IS ONE THAT SNOW LOVERS DREAM OF HAVING DURING THE WINTER
MONTHS...BUT ALAS...THEY WILL HAVE TO BE CONTENT WITH COMFORTABLY
COOL LATE SUMMER CONDITIONS. A DEEP TROUGH WILL BE RE-ESTABLISHED
ACROSS EASTERN CANADA AND THE GREAT LAKES REGION AT THE START OF
THIS PERIOD...WITH ADDITIONAL SHORTWAVE ENERGY DIVING INTO ITS BASE
AND THE BUILDING OF A GREENLAND BLOCK INSURING THAT THE HIGH
AMPLITUDE BLOCKING PATTERN WILL BE ANCHORED IN PLACE FOR SOME TIME
TO COME. THIS GENERAL LONGWAVE PATTERN IS STRONGLY SUPPORTED BY ALL
MEDIUM RANGE ENSEMBLE PACKAGES AS WELL AS CPC FORECASTS OF
HEMISPHERIC PROCESSES...LIKE THE NAO AND PNA. MORE ON THIS IN THE
LONG RANGE DISCUSSION BELOW. NOW FOCUSING IN ON THE DETAILS...
A COLD FRONT WILL MARCH ACROSS OUR FORECAST AREA ON THURSDAY...
WITH WIDESPREAD SHOWERS AND POSSIBLY A FEW EMBEDDED THUNDERSTORMS
EXPECTED AS A RESULT. THE GUIDANCE PACKAGES HAVE BEEN DEPICTING A
PROGRESSIVELY EARLIER ONSET OF PCPN FOR THE PAST SEVERAL RUNS...AND
IT SEEMS AS IF THIS IS TIED DIRECTLY TO THE SPEED AND PLACEMENT OF
THE FAVORABLE UPPER LEVEL LIFT SUPPLIED BY A 100KT H25 JET OVER
WESTERN QUEBEC. A 3 TO 5 HOUR PERIOD OF SHOWERS WILL BE ASSOCIATED
WITH THE LIFT FOUND WITHIN THE RR ENTRANCE REGION OF THIS JET...
WITH LINGERING SHOWERS FOUND BACK IN THE VCNTY OF THE LOW LEVEL
FORCING NEAR THE FRONT. THIS WILL BOIL DOWN TO THE BULK OF THE
SHOWERS COMING DURING THE MORNING HOURS FOR THE WRN COUNTIES...AND
DURING THE MIDDAY FOR SITES EAST OF LK ONTARIO. THE SHOWERS WILL
THUS QUICKLY TAPER OFF FROM WEST TO EAST DURING THE COURSE OF THE
AFTERNOON. HAVE RAISED POPS TO 90 REGIONWIDE WITH BASIN AVERAGE QPF
RANGING FROM A QUARTER TO A HALF INCH.
BY THURSDAY EVENING...THE PLUME OF DEEP MOISTURE AHEAD OF THE
FRONT WILL BE RACING ACROSS NEW ENGLAND WHILE THE ACTUAL SFC FRONT
WILL ONLY BE SLOWLY MAKING ITS WAY ACROSS THE EASTERN LAKE ONTARIO
REGION. THIS WILL KEEP THE LIKELIHOOD FOR SOME SHOWERS OVER THE
EASTERN FINGER LAKES AND FOR SITES EAST OF LK ONTARIO...WITH JUST
SPOTTY LIGHT SHOWERS POSSIBLE UNDER A PASSING SHORTWAVE ACROSS THE
WRN COUNTIES. THE TREND WILL DEFINTIELY BE TOWARDS DRIER WEATHER
THOUGH AS LOW LEVEL RIDGING WILL BUILD EAST FROM LOWER MICHIGAN AND
THE OHIO VALLEY.
ANOTHER ISSUE TO KEEP AN EYE ON WILL BE MARGINALLY FAVORABLE
CONDITIONS FOR NUISANCE LAKE EFFECT DURING THE WEE HOURS OF
FRIDAY MORNING. H85 TEMPS ARE FORECAST TO DROP TO AROUND 10C BY
DAYBREAK...AND WITH LK SFC TEMPS IN THE VCNTY OF 22C...THAT WOULD
ONLY SUPPORT WEAK INSTABILITY. THERE WILL ALSO BE LIMITED SYNOPTIC
MOISTURE TO WORK WITH...SO WILL CONTINUE SLGT CHC POPS EAST OF LK
ERIE AND LOW CHC POPS EAST OF LK ONTARIO FOR ANY MINOR LAKE
RESPONSE.
ON FRIDAY AND FRIDAY NIGHT...A SERIES OF WEAK SHORT WAVES WILL
ROTATE THROUGH THE BASE OF THE UPPER LEVEL TROUGH THAT WILL BE
FIRMLY ESTABLISHED OVER THE GREAT LAKES. WHILE THE VAST MAJORITY OF
THIS 24 HOUR PERIOD SHOULD BE RAIN FREE...SCATTERED LIGHT SHOWERS
WILL BE POSSIBLE. THE COMBINATION OF LATE SUMMER HEATING DURING THE
MIDDAY/AFTERNOON WILL COMBINE WITH A SEASONABLY COOL AIRMASS TO
GENERATE LOW LEVEL LAPSE RATES OF 9-10 DEG C/KM...AND THIS ALONG
WITH THE FORCING FROM THE AFOREMENTIONED SHORTWAVE SHOULD BE ENOUGH
TO SUPPORT CHC POPS THROUGH THE EVENING HOURS. THE OVERNIGHT SHOULD
LARGELY BE RAIN FREE...WITH ONLY CHC POPS EAST OF LK ONTARIO FOR
SOME LAKE EFFECT. TEMPS FRIDAY WILL AVERAGE ABOUT 5 DEG F BELOW
NORMAL WITH AFTERNOON HIGHS GENERALLY IN THE MID 70S.
SATURDAY SHOULD BE A FAIRLY NICE DAY...ALBEIT IT SEASONABLY COOL AS
SFC HIGH PRESSURE CENTERED OVER THE CANADIAN PRAIRIES WILL BUILD
SOUTHEAST ACROSS ALL OF THE GREAT LAKES. THIS SHOULD ENCOURAGE
PARTIAL SUNSHINE ACROSS THE REGION WITH H85 TEMPS HOLDING MAX TEMPS
IN THE LOW TO MID 70S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
ALL OF THE THE MEDIUM RANGE ENSEMBLES REMAIN IN STRONG AGREEMENT
THAT THE DEEP...UPPER LEVEL TROUGH WILL HOLD IN PLACE ACROSS EASTERN
NORTH AMERICA THROUGH MUCH IF NOT ALL OF NEXT WEEK. THIS SCENARIO
WILL GUARANTEE THAT WE WILL CONTINUE TO EXPERIENCE BELOW NORMAL
TEMPERATURES...ALTHOUGH NOT ANOMALOUSLY SO AS MERCURY LEVELS WILL
GENERALLY AVERAGING 3-5 DEG F BELOW NORMAL.
IN TERMS OF PCPN...THE BULK OF THIS TIME PERIOD WILL BE RAINFREE.
BESIDES THE LOW CHC FOR NUISANCE LAKE SHOWERS SOUTHEAST OF LK
ONTARIO...CANADIAN HIGH PRESSURE BUILDING ACROSS THE LOWER GREAT
SHOULD PROVIDE THE REGION WITH DRY WEATHER SUNDAY AND MONDAY. THE
ECMWF HAS BECOME THE OUTLIER ON SUNDAY IN THAT IT SUGGESTS THAT A
VIGOROUS SHORTWAVE WILL GENERATE SOME SHOWERS...BUT THIS IS A NEW
SOLUTION AND ONE THAT IS NOT SUPPORTED BY OTHER PACKAGES.
THE POTENTIAL FOR A FAIRLY POTENT SHORTWAVE AND ASSOCIATED SFC WAVE
TO PASS THROUGH THE REGION ON TUESDAY WILL NECESSITATE THE
INTRODUCTION OF CHC POPS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDS PREVAIL ACROSS THE REGION AND WILL SO THROUGH THE EARLY
EVENING. CLOUDS WILL BECOME OVERCAST DURING THE EVENING HOURS WITH
CIGS LOWERING TO MVFR BEFORE DAYBREAK ACROSS FINGER LAKES AND
WEST... AND CONTINUING TO LOWER ACROSS THE EASTERN SECTIONS
THURSDAY MORNING. SHOWERS AND SCATTERED THUNDERSTORMS WILL
OVERSPREAD FROM WEST TO EAST MAINLY FROM MIDNIGHT ONWARD.
FOLLOWING FROPA...CONDS WILL THEN IMPROVE TO VFR FROM WEST TO EAST
ON THURSDAY.
OUTLOOK...
FRIDAY AND SATURDAY...MAINLY VFR WITH A SMALL CHANCE OF SHOWERS.
SUNDAY...VFR.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE ACROSS THE
LOWER LAKES TONIGHT. AFTER A FRONT CROSSES THE LAKES ON
THURSDAY...THE WINDS WILL SWITCH TO THE SOUTHWEST AND PICK UP A
BIT...BUT CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. MORE IMPORTANTLY...THE FRONT WILL BRING A GOOD
CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS TONIGHT AND
THURSDAY...WITH LOCAL INCREASES IN WIND AND WAVES POSSIBLE.
THE PRESSURE GRADIENT BETWEEN BETWEEN A SURFACE HIGH OVER THE MIDDLE
ATLANTIC STATES AND LOW PRESSURE PUSHING ACROSS HUDSON BAY WILL
CAUSE WESTERLY WINDS TO PICK UP A LITTLE MORE ON FRIDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LEVAN
NEAR TERM...LEVAN
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...LEVAN
MARINE...LEVAN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
948 AM EDT WED JUL 31 2013
.SYNOPSIS...
HIGH PRESSURE PUSHING EAST ACROSS NEW YORK AND PENNSYLVANIA WILL
BRING DRY WEATHER AND SEASONABLE TEMPERATURES TO THE AREA TODAY.
MEANWHILE...MOISTURE ASSOCIATED WITH A PASSING COLD FRONT WILL BRING
A GOOD CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS TONIGHT AND
THURSDAY. LINGERING MOISTURE AND SOMEWHAT UNSTABLE AIR BEHIND THE
FRONT MAY BRING A FEW MORE SHOWERS ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE CENTERED OVER NEW YORK AND PA WILL PROVIDE US WITH
DRY WEATHER AND SEASONABLE TEMPERATURES TODAY. THERE WILL BE A
GRADUAL INCREASE IN MID AND HIGH LEVEL CLOUDS AS MOISTURE
ASSOCIATED WITH WARM AIR ADVECTION OVER THE OHIO VALLEY AND
CENTRAL GREAT LAKES MOVES SLOWLY TO THE EAST. REGIONAL RADARS SHOW
AN EXPANDING AREA OF SHOWERS OVER MICHIGAN AND CENTRAL
OHIO...MOVING SLOWLY TO THE EAST. THE EASTERN EDGE OF THIS PCPN
MAY REACH FAR WESTERN NEW YORK LATE IN THE DAY...BUT THE REST OF
THE AREA SHOULD STAY DRY.
A LIGHT SOUTHERLY FLOW AHEAD OF THE MIDWEST COLD FRONT FRONT WILL
ALLOW TEMPERATURES TO WARM GENERALLY INTO THE MID AND UPPER 70S
DURING THE AFTERNOON...WITH A FEW SPOTS ACROSS THE GENESEE VALLEY
AND FINGER LAKES POSSIBLY WARMING INTO THE LOWER 80S...DEPENDING ON
HOW EXTENSIVE THE MID LEVEL CLOUDS BECOME.
CONDITIONS WILL DETERIORATE THIS EVENING AND TONIGHT AS MOISTURE
DEEPENS AHEAD OF THE APPROACHING COLD FRONT. THE LATEST GUIDANCE
STILL SHOWS STRONG FRONTOGENETIC FORCING IN THE MID LEVELS OF THE
ATMOSPHERE...WHILE A DECENT UPPER LEVEL JET LIFTS NORTH INTO WESTERN
QUEBEC. AS THESE SOURCES OF FAVORABLE LIFT INTERACT WITH THE
INCREASING MOISTURE...A PERIOD OF MODERATE RAIN IS POSSIBLE
...ESPECIALLY DURING THE SECOND HALF OF THE NIGHT. WHILE THE NAM AND
GFS QPF OUTPUTS APPEAR TO BE SUFFERING FROM CONVECTIVE FEEDBACK...A
SOLID HALF INCH OF RAIN IS POSSIBLE ACROSS PARTS OF WESTERN NEW YORK
BEFORE DAYBREAK.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THE LONGWAVE PATTERN THAT WE WILL BE IN DURING THE NEXT WEEK TO TEN
DAYS IS ONE THAT SNOW LOVERS DREAM OF HAVING DURING THE WINTER
MONTHS...BUT ALAS...THEY WILL HAVE TO BE CONTENT WITH COMFORTABLY
COOL LATE SUMMER CONDITIONS. A DEEP TROUGH WILL BE RE-ESTABLISHED
ACROSS EASTERN CANADA AND THE GREAT LAKES REGION AT THE START OF
THIS PERIOD...WITH ADDITIONAL SHORTWAVE ENERGY DIVING INTO ITS BASE
AND THE BUILDING OF A GREENLAND BLOCK INSURING THAT THE HIGH
AMPLITUDE BLOCKING PATTERN WILL BE ANCHORED IN PLACE FOR SOME TIME
TO COME. THIS GENERAL LONGWAVE PATTERN IS STRONGLY SUPPORTED BY ALL
MEDIUM RANGE ENSEMBLE PACKAGES AS WELL AS CPC FORECASTS OF
HEMISPHERIC PROCESSES...LIKE THE NAO AND PNA. MORE ON THIS IN THE
LONG RANGE DISCUSSION BELOW. NOW FOCUSING IN ON THE DETAILS...
A COLD FRONT WILL MARCH ACROSS OUR FORECAST AREA ON THURSDAY...
WITH WIDESPREAD SHOWERS AND POSSIBLY A FEW EMBEDDED THUNDERSTORMS
EXPECTED AS A RESULT. THE GUIDANCE PACKAGES HAVE BEEN DEPICTING A
PROGRESSIVELY EARLIER ONSET OF PCPN FOR THE PAST SEVERAL RUNS...AND
IT SEEMS AS IF THIS IS TIED DIRECTLY TO THE SPEED AND PLACEMENT OF
THE FAVORABLE UPPER LEVEL LIFT SUPPLIED BY A 100KT H25 JET OVER
WESTERN QUEBEC. A 3 TO 5 HOUR PERIOD OF SHOWERS WILL BE ASSOCIATED
WITH THE LIFT FOUND WITHIN THE RR ENTRANCE REGION OF THIS JET...
WITH LINGERING SHOWERS FOUND BACK IN THE VCNTY OF THE LOW LEVEL
FORCING NEAR THE FRONT. THIS WILL BOIL DOWN TO THE BULK OF THE
SHOWERS COMING DURING THE MORNING HOURS FOR THE WRN COUNTIES...AND
DURING THE MIDDAY FOR SITES EAST OF LK ONTARIO. THE SHOWERS WILL
THUS QUICKLY TAPER OFF FROM WEST TO EAST DURING THE COURSE OF THE
AFTERNOON. HAVE RAISED POPS TO 90 REGIONWIDE WITH BASIN AVERAGE QPF
RANGING FROM A QUARTER TO A HALF INCH.
BY THURSDAY EVENING...THE PLUME OF DEEP MOISTURE AHEAD OF THE
FRONT WILL BE RACING ACROSS NEW ENGLAND WHILE THE ACTUAL SFC FRONT
WILL ONLY BE SLOWLY MAKING ITS WAY ACROSS THE EASTERN LAKE ONTARIO
REGION. THIS WILL KEEP THE LIKELIHOOD FOR SOME SHOWERS OVER THE
EASTERN FINGER LAKES AND FOR SITES EAST OF LK ONTARIO...WITH JUST
SPOTTY LIGHT SHOWERS POSSIBLE UNDER A PASSING SHORTWAVE ACROSS THE
WRN COUNTIES. THE TREND WILL DEFINTIELY BE TOWARDS DRIER WEATHER
THOUGH AS LOW LEVEL RIDGING WILL BUILD EAST FROM LOWER MICHIGAN AND
THE OHIO VALLEY.
ANOTHER ISSUE TO KEEP AN EYE ON WILL BE MARGINALLY FAVORABLE
CONDITIONS FOR NUISANCE LAKE EFFECT DURING THE WEE HOURS OF
FRIDAY MORNING. H85 TEMPS ARE FORECAST TO DROP TO AROUND 10C BY
DAYBREAK...AND WITH LK SFC TEMPS IN THE VCNTY OF 22C...THAT WOULD
ONLY SUPPORT WEAK INSTABILITY. THERE WILL ALSO BE LIMITED SYNOPTIC
MOISTURE TO WORK WITH...SO WILL CONTINUE SLGT CHC POPS EAST OF LK
ERIE AND LOW CHC POPS EAST OF LK ONTARIO FOR ANY MINOR LAKE
RESPONSE.
ON FRIDAY AND FRIDAY NIGHT...A SERIES OF WEAK SHORT WAVES WILL
ROTATE THROUGH THE BASE OF THE UPPER LEVEL TROUGH THAT WILL BE
FIRMLY ESTABLISHED OVER THE GREAT LAKES. WHILE THE VAST MAJORITY OF
THIS 24 HOUR PERIOD SHOULD BE RAIN FREE...SCATTERED LIGHT SHOWERS
WILL BE POSSIBLE. THE COMBINATION OF LATE SUMMER HEATING DURING THE
MIDDAY/AFTERNOON WILL COMBINE WITH A SEASONABLY COOL AIRMASS TO
GENERATE LOW LEVEL LAPSE RATES OF 9-10 DEG C/KM...AND THIS ALONG
WITH THE FORCING FROM THE AFOREMENTIONED SHORTWAVE SHOULD BE ENOUGH
TO SUPPORT CHC POPS THROUGH THE EVENING HOURS. THE OVERNIGHT SHOULD
LARGELY BE RAIN FREE...WITH ONLY CHC POPS EAST OF LK ONTARIO FOR
SOME LAKE EFFECT. TEMPS FRIDAY WILL AVERAGE ABOUT 5 DEG F BELOW
NORMAL WITH AFTERNOON HIGHS GENERALLY IN THE MID 70S.
SATURDAY SHOULD BE A FAIRLY NICE DAY...ALBEIT IT SEASONABLY COOL AS
SFC HIGH PRESSURE CENTERED OVER THE CANADIAN PRAIRIES WILL BUILD
SOUTHEAST ACROSS ALL OF THE GREAT LAKES. THIS SHOULD ENCOURAGE
PARTIAL SUNSHINE ACROSS THE REGION WITH H85 TEMPS HOLDING MAX TEMPS
IN THE LOW TO MID 70S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
ALL OF THE THE MEDIUM RANGE ENSEMBLES REMAIN IN STRONG AGREEMENT
THAT THE DEEP...UPPER LEVEL TROUGH WILL HOLD IN PLACE ACROSS EASTERN
NORTH AMERICA THROUGH MUCH IF NOT ALL OF NEXT WEEK. THIS SCENARIO
WILL GUARANTEE THAT WE WILL CONTINUE TO EXPERIENCE BELOW NORMAL
TEMPERATURES...ALTHOUGH NOT ANOMALOUSLY SO AS MERCURY LEVELS WILL
GENERALLY AVERAGING 3-5 DEG F BELOW NORMAL.
IN TERMS OF PCPN...THE BULK OF THIS TIME PERIOD WILL BE RAINFREE.
BESIDES THE LOW CHC FOR NUISANCE LAKE SHOWERS SOUTHEAST OF LK
ONTARIO...CANADIAN HIGH PRESSURE BUILDING ACROSS THE LOWER GREAT
SHOULD PROVIDE THE REGION WITH DRY WEATHER SUNDAY AND MONDAY. THE
ECMWF HAS BECOME THE OUTLIER ON SUNDAY IN THAT IT SUGGESTS THAT A
VIGOROUS SHORTWAVE WILL GENERATE SOME SHOWERS...BUT THIS IS A NEW
SOLUTION AND ONE THAT IS NOT SUPPORTED BY OTHER PACKAGES.
THE POTENTIAL FOR A FAIRLY POTENT SHORTWAVE AND ASSOCIATED SFC WAVE
TO PASS THROUGH THE REGION ON TUESDAY WILL NECESSITATE THE
INTRODUCTION OF CHC POPS.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
PATCHY FOG ACROSS THE SOUTHERN TIER WILL BURN OFF BY MID MORNING.
OTHERWISE...HIGH PRESSURE CENTERED OVER NY AND PA WILL MAINTAIN VFR
CONDITIONS ACROSS THE AREA TODAY. THERE WILL BE AN INCREASE IN MID
AND HIGH LEVEL CLOUDS LATER THIS MORNING AND DURING THE AFTERNOON AS
MOISTURE DEVELOPING AHEAD OF THE MIDWEST COLD FRONT MOVES SLOWLY TO
THE EAST.
SHOWERS AND POSSIBLE THUNDERSTORMS WILL THEN SPREAD ACROSS THE AREA
THIS EVENING AND TONIGHT AS THE APPROACHING FRONT INTERACTS WITH
INCREASING MOISTURE LIFTING NORTH FROM THE OHIO VALLEY. WITH MORE
WIDESPREAD SHOWERS...CONDITIONS WILL GRADUALLY LOWER TO MVFR BEFORE
DAYBREAK AT MOST TAF SITES WEST OF KART.
OUTLOOK...
THURSDAY...VFR/MVFR WITH SHOWERS AND A FEW SCATTERED THUNDERSTORMS
PRODUCING ASSOCIATED BRIEF IFR.
FRIDAY AND SATURDAY...MAINLY VFR WITH A SMALL CHANCE OF SHOWERS.
SUNDAY...VFR.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE ACROSS THE
LOWER LAKES TODAY AND TONIGHT. AFTER A FRONT CROSSES THE LAKES ON
THURSDAY...THE WINDS WILL SWITCH TO THE SOUTHWEST AND PICK UP A
BIT...BUT CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. MORE IMPORTANTLY...THE FRONT WILL BRING A GOOD
CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS TONIGHT AND
THURSDAY...WITH LOCAL INCREASES IN WIND AND WAVES POSSIBLE.
THE PRESSURE GRADIENT BETWEEN BETWEEN A SURFACE HIGH OVER THE MIDDLE
ATLANTIC STATES AND LOW PRESSURE PUSHING ACROSS HUDSON BAY WILL
CAUSE WESTERLY WINDS TO PICK UP A LITTLE MORE ON FRIDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TJP
NEAR TERM...LEVAN/TJP
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...LEVAN/TJP
MARINE...LEVAN/TJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
717 AM EDT WED JUL 31 2013
.SYNOPSIS...
HIGH PRESSURE PUSHING EAST ACROSS NEW YORK AND PENNSYLVANIA WILL
BRING DRY WEATHER AND SEASONABLE TEMPERATURES TO THE AREA TODAY.
MEANWHILE...MOISTURE ASSOCIATED WITH A PASSING COLD FRONT WILL BRING
A GOOD CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS TONIGHT AND
THURSDAY. LINGERING MOISTURE AND SOMEWHAT UNSTABLE AIR BEHIND THE
FRONT MAY BRING A FEW MORE SHOWERS ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
PATCHY FOG ACROSS THE SOUTHERN TIER WILL DISSIPATE BY MID
MORNING. OTHERWISE...HIGH PRESSURE CENTERED OVER NEW YORK AND PA
WILL PROVIDE US WITH DRY WEATHER AND SEASONABLE TEMPERATURES
TODAY. THERE WILL BE A GRADUAL INCREASE IN MID AND HIGH LEVEL
CLOUDS AS MOISTURE ASSOCIATED WITH WARM AIR ADVECTION OVER THE
OHIO VALLEY AND CENTRAL GREAT LAKES MOVES SLOWLY TO THE EAST.
REGIONAL RADARS SHOW AN EXPANDING AREA OF SHOWERS OVER MICHIGAN
AND CENTRAL OHIO...MOVING SLOWLY TO THE EAST. THE EASTERN EDGE OF
THIS PCPN MAY REACH FAR WESTERN NEW YORK LATE IN THE DAY...BUT THE
REST OF THE AREA SHOULD STAY DRY.
A LIGHT SOUTHERLY FLOW AHEAD OF THE MIDWEST COLD FRONT FRONT WILL
ALLOW TEMPERATURES TO WARM GENERALLY INTO THE MID AND UPPER 70S
DURING THE AFTERNOON...WITH A FEW SPOTS ACROSS THE GENESEE VALLEY
AND FINGER LAKES POSSIBLY WARMING INTO THE LOWER 80S...DEPENDING ON
HOW EXTENSIVE THE MID LEVEL CLOUDS BECOME.
CONDITIONS WILL DETERIORATE THIS EVENING AND TONIGHT AS MOISTURE
DEEPENS AHEAD OF THE APPROACHING COLD FRONT. THE LATEST GUIDANCE
STILL SHOWS STRONG FRONTOGENETIC FORCING IN THE MID LEVELS OF THE
ATMOSPHERE...WHILE A DECENT UPPER LEVEL JET LIFTS NORTH INTO WESTERN
QUEBEC. AS THESE SOURCES OF FAVORABLE LIFT INTERACT WITH THE
INCREASING MOISTURE...A PERIOD OF MODERATE RAIN IS POSSIBLE
...ESPECIALLY DURING THE SECOND HALF OF THE NIGHT. WHILE THE NAM AND
GFS QPF OUTPUTS APPEAR TO BE SUFFERING FROM CONVECTIVE FEEDBACK...A
SOLID HALF INCH OF RAIN IS POSSIBLE ACROSS PARTS OF WESTERN NEW YORK
BEFORE DAYBREAK.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THE LONGWAVE PATTERN THAT WE WILL BE IN DURING THE NEXT WEEK TO TEN
DAYS IS ONE THAT SNOW LOVERS DREAM OF HAVING DURING THE WINTER
MONTHS...BUT ALAS...THEY WILL HAVE TO BE CONTENT WITH COMFORTABLY
COOL LATE SUMMER CONDITIONS. A DEEP TROUGH WILL BE RE-ESTABLISHED
ACROSS EASTERN CANADA AND THE GREAT LAKES REGION AT THE START OF
THIS PERIOD...WITH ADDITIONAL SHORTWAVE ENERGY DIVING INTO ITS BASE
AND THE BUILDING OF A GREENLAND BLOCK INSURING THAT THE HIGH
AMPLITUDE BLOCKING PATTERN WILL BE ANCHORED IN PLACE FOR SOME TIME
TO COME. THIS GENERAL LONGWAVE PATTERN IS STRONGLY SUPPORTED BY ALL
MEDIUM RANGE ENSEMBLE PACKAGES AS WELL AS CPC FORECASTS OF
HEMISPHERIC PROCESSES...LIKE THE NAO AND PNA. MORE ON THIS IN THE
LONG RANGE DISCUSSION BELOW. NOW FOCUSING IN ON THE DETAILS...
A COLD FRONT WILL MARCH ACROSS OUR FORECAST AREA ON THURSDAY...
WITH WIDESPREAD SHOWERS AND POSSIBLY A FEW EMBEDDED THUNDERSTORMS
EXPECTED AS A RESULT. THE GUIDANCE PACKAGES HAVE BEEN DEPICTING A
PROGRESSIVELY EARLIER ONSET OF PCPN FOR THE PAST SEVERAL RUNS...AND
IT SEEMS AS IF THIS IS TIED DIRECTLY TO THE SPEED AND PLACEMENT OF
THE FAVORABLE UPPER LEVEL LIFT SUPPLIED BY A 100KT H25 JET OVER
WESTERN QUEBEC. A 3 TO 5 HOUR PERIOD OF SHOWERS WILL BE ASSOCIATED
WITH THE LIFT FOUND WITHIN THE RR ENTRANCE REGION OF THIS JET...
WITH LINGERING SHOWERS FOUND BACK IN THE VCNTY OF THE LOW LEVEL
FORCING NEAR THE FRONT. THIS WILL BOIL DOWN TO THE BULK OF THE
SHOWERS COMING DURING THE MORNING HOURS FOR THE WRN COUNTIES...AND
DURING THE MIDDAY FOR SITES EAST OF LK ONTARIO. THE SHOWERS WILL
THUS QUICKLY TAPER OFF FROM WEST TO EAST DURING THE COURSE OF THE
AFTERNOON. HAVE RAISED POPS TO 90 REGIONWIDE WITH BASIN AVERAGE QPF
RANGING FROM A QUARTER TO A HALF INCH.
BY THURSDAY EVENING...THE PLUME OF DEEP MOISTURE AHEAD OF THE
FRONT WILL BE RACING ACROSS NEW ENGLAND WHILE THE ACTUAL SFC FRONT
WILL ONLY BE SLOWLY MAKING ITS WAY ACROSS THE EASTERN LAKE ONTARIO
REGION. THIS WILL KEEP THE LIKELIHOOD FOR SOME SHOWERS OVER THE
EASTERN FINGER LAKES AND FOR SITES EAST OF LK ONTARIO...WITH JUST
SPOTTY LIGHT SHOWERS POSSIBLE UNDER A PASSING SHORTWAVE ACROSS THE
WRN COUNTIES. THE TREND WILL DEFINTIELY BE TOWARDS DRIER WEATHER
THOUGH AS LOW LEVEL RIDGING WILL BUILD EAST FROM LOWER MICHIGAN AND
THE OHIO VALLEY.
ANOTHER ISSUE TO KEEP AN EYE ON WILL BE MARGINALLY FAVORABLE
CONDITIONS FOR NUISANCE LAKE EFFECT DURING THE WEE HOURS OF
FRIDAY MORNING. H85 TEMPS ARE FORECAST TO DROP TO AROUND 10C BY
DAYBREAK...AND WITH LK SFC TEMPS IN THE VCNTY OF 22C...THAT WOULD
ONLY SUPPORT WEAK INSTABILITY. THERE WILL ALSO BE LIMITED SYNOPTIC
MOISTURE TO WORK WITH...SO WILL CONTINUE SLGT CHC POPS EAST OF LK
ERIE AND LOW CHC POPS EAST OF LK ONTARIO FOR ANY MINOR LAKE
RESPONSE.
ON FRIDAY AND FRIDAY NIGHT...A SERIES OF WEAK SHORT WAVES WILL
ROTATE THROUGH THE BASE OF THE UPPER LEVEL TROUGH THAT WILL BE
FIRMLY ESTABLISHED OVER THE GREAT LAKES. WHILE THE VAST MAJORITY OF
THIS 24 HOUR PERIOD SHOULD BE RAIN FREE...SCATTERED LIGHT SHOWERS
WILL BE POSSIBLE. THE COMBINATION OF LATE SUMMER HEATING DURING THE
MIDDAY/AFTERNOON WILL COMBINE WITH A SEASONABLY COOL AIRMASS TO
GENERATE LOW LEVEL LAPSE RATES OF 9-10 DEG C/KM...AND THIS ALONG
WITH THE FORCING FROM THE AFOREMENTIONED SHORTWAVE SHOULD BE ENOUGH
TO SUPPORT CHC POPS THROUGH THE EVENING HOURS. THE OVERNIGHT SHOULD
LARGELY BE RAIN FREE...WITH ONLY CHC POPS EAST OF LK ONTARIO FOR
SOME LAKE EFFECT. TEMPS FRIDAY WILL AVERAGE ABOUT 5 DEG F BELOW
NORMAL WITH AFTERNOON HIGHS GENERALLY IN THE MID 70S.
SATURDAY SHOULD BE A FAIRLY NICE DAY...ALBEIT IT SEASONABLY COOL AS
SFC HIGH PRESSURE CENTERED OVER THE CANADIAN PRAIRIES WILL BUILD
SOUTHEAST ACROSS ALL OF THE GREAT LAKES. THIS SHOULD ENCOURAGE
PARTIAL SUNSHINE ACROSS THE REGION WITH H85 TEMPS HOLDING MAX TEMPS
IN THE LOW TO MID 70S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
ALL OF THE THE MEDIUM RANGE ENSEMBLES REMAIN IN STRONG AGREEMENT
THAT THE DEEP...UPPER LEVEL TROUGH WILL HOLD IN PLACE ACROSS EASTERN
NORTH AMERICA THROUGH MUCH IF NOT ALL OF NEXT WEEK. THIS SCENARIO
WILL GUARANTEE THAT WE WILL CONTINUE TO EXPERIENCE BELOW NORMAL
TEMPERATURES...ALTHOUGH NOT ANOMALOUSLY SO AS MERCURY LEVELS WILL
GENERALLY AVERAGING 3-5 DEG F BELOW NORMAL.
IN TERMS OF PCPN...THE BULK OF THIS TIME PERIOD WILL BE RAINFREE.
BESIDES THE LOW CHC FOR NUISANCE LAKE SHOWERS SOUTHEAST OF LK
ONTARIO...CANADIAN HIGH PRESSURE BUILDING ACROSS THE LOWER GREAT
SHOULD PROVIDE THE REGION WITH DRY WEATHER SUNDAY AND MONDAY. THE
ECMWF HAS BECOME THE OUTLIER ON SUNDAY IN THAT IT SUGGESTS THAT A
VIGOROUS SHORTWAVE WILL GENERATE SOME SHOWERS...BUT THIS IS A NEW
SOLUTION AND ONE THAT IS NOT SUPPORTED BY OTHER PACKAGES.
THE POTENTIAL FOR A FAIRLY POTENT SHORTWAVE AND ASSOCIATED SFC WAVE
TO PASS THROUGH THE REGION ON TUESDAY WILL NECESSITATE THE
INTRODUCTION OF CHC POPS.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
PATCHY FOG ACROSS THE SOUTHERN TIER WILL BURN OFF BY MID MORNING.
OTHERWISE...HIGH PRESSURE CENTERED OVER NY AND PA WILL MAINTAIN VFR
CONDITIONS ACROSS THE AREA TODAY. THERE WILL BE AN INCREASE IN MID
AND HIGH LEVEL CLOUDS LATER THIS MORNING AND DURING THE AFTERNOON AS
MOISTURE DEVELOPING AHEAD OF THE MIDWEST COLD FRONT MOVES SLOWLY TO
THE EAST.
SHOWERS AND POSSIBLE THUNDERSTORMS WILL THEN SPREAD ACROSS THE AREA
THIS EVENING AND TONIGHT AS THE APPROACHING FRONT INTERACTS WITH
INCREASING MOISTURE LIFTING NORTH FROM THE OHIO VALLEY. WITH MORE
WIDESPREAD SHOWERS...CONDITIONS WILL GRADUALLY LOWER TO MVFR BEFORE
DAYBREAK AT MOST TAF SITES WEST OF KART.
OUTLOOK...
THURSDAY...VFR/MVFR WITH SHOWERS AND A FEW SCATTERED THUNDERSTORMS
PRODUCING ASSOCIATED BRIEF IFR.
FRIDAY AND SATURDAY...MAINLY VFR WITH A SMALL CHANCE OF SHOWERS.
SUNDAY...VFR.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE ACROSS THE
LOWER LAKES TODAY AND TONIGHT. AFTER A FRONT CROSSES THE LAKES ON
THURSDAY...THE WINDS WILL SWITCH TO THE SOUTHWEST AND PICK UP A
BIT...BUT CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. MORE IMPORTANTLY...THE FRONT WILL BRING A GOOD
CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS TONIGHT AND
THURSDAY...WITH LOCAL INCREASES IN WIND AND WAVES POSSIBLE.
THE PRESSURE GRADIENT BETWEEN BETWEEN A SURFACE HIGH OVER THE MIDDLE
ATLANTIC STATES AND LOW PRESSURE PUSHING ACROSS HUDSON BAY WILL
CAUSE WESTERLY WINDS TO PICK UP A LITTLE MORE ON FRIDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TJP
NEAR TERM...TJP
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...TJP
MARINE...TJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
447 AM EDT WED JUL 31 2013
.SYNOPSIS...
HIGH PRESSURE PUSHING EAST ACROSS NEW YORK AND PENNSYLVANIA WILL
BRING DRY WEATHER AND SEASONABLE TEMPERATURES TO THE AREA TODAY.
MEANWHILE...MOISTURE ASSOCIATED WITH A PASSING COLD FRONT WILL BRING
A GOOD CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS TONIGHT AND
THURSDAY. LINGERING MOISTURE AND SOMEWHAT UNSTABLE AIR BEHIND THE
FRONT MAY BRING A FEW MORE SHOWERS ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE CENTERED OVER NY AND PA EARLY THIS MORNING IS BRINGING
MAINLY CLEAR SKIES TO THE AREA...ALTHOUGH HIGH CLOUDS CONTINUE TO
SKIRT PARTS OF WESTERN NEW YORK AND THE SOUTHERN TIER. THE PRESENCE
OF THE CLOUDS WILL LIKELY LIMIT THE EXTENT OF VALLEY THAT DEVELOPS
BEFORE DAYBREAK...ESPECIALLY BASED ON THE LATEST TREND SHOWN ON THE
IR SATELLITE LOOP WHICH SUGGESTS THAT THE HIGH LEVEL CLOUDS WILL
EXPAND ACROSS THE AREA.
AFTER THE EARLY MORNING FOG DISSIPATES...MID AND HIGH LEVEL CLOUDS
WILL CONTINUE TO SPREAD EAST ACROSS THE AREA TODAY AS THE COLD FRONT
OVER THE PLAINS STATES MOVES EAST INTO THE CENTRAL GREAT LAKES. A
LIGHT SOUTHERLY FLOW AHEAD OF THE FRONT WILL ALLOW TEMPERATURES TO
WARM GENERALLY INTO THE MID AND UPPER 70S DURING THE
AFTERNOON...WITH A FEW SPOTS ACROSS THE SOUTHERN TIER AND FINGER
LAKES POSSIBLY WARMING INTO THE LOWER 80S...DEPENDING ON HOW
EXTENSIVE THE MID LEVEL CLOUDS BECOME.
CONDITIONS WILL DETERIORATE TONIGHT AS MOISTURE DEEPENS AHEAD OF THE
APPROACHING COLD FRONT. THE LATEST GUIDANCE STILL SHOWS STRONG
FRONTOGENETIC FORCING IN THE MID LEVELS OF THE ATMOSPHERE...WHILE A
DECENT UPPER LEVEL JET LIFTS NORTH INTO WESTERN QUEBEC. AS THESE
SOURCES OF FAVORABLE LIFT INTERACT WITH THE INCREASING MOISTURE...
A PERIOD OF MODERATE RAIN IS POSSIBLE...ESPECIALLY DURING THE SECOND
HALF OF THE NIGHT. WHILE THE NAM AND GFS QPF OUTPUTS APPEAR TO BE
SUFFERING FROM CONVECTIVE FEEDBACK...A SOLID HALF INCH OF RAIN IS
POSSIBLE ACROSS PARTS OF WESTERN NEW YORK BEFORE DAYBREAK.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THE LONGWAVE PATTERN THAT WE WILL BE IN DURING THE NEXT WEEK TO TEN
DAYS IS ONE THAT SNOW LOVERS DREAM OF HAVING DURING THE WINTER
MONTHS...BUT ALAS...THEY WILL HAVE TO BE CONTENT WITH COMFORTABLY
COOL LATE SUMMER CONDITIONS. A DEEP TROUGH WILL BE RE-ESTABLISHED
ACROSS EASTERN CANADA AND THE GREAT LAKES REGION AT THE START OF
THIS PERIOD...WITH ADDITIONAL SHORTWAVE ENERGY DIVING INTO ITS BASE
AND THE BUILDING OF A GREENLAND BLOCK INSURING THAT THE HIGH
AMPLITUDE BLOCKING PATTERN WILL BE ANCHORED IN PLACE FOR SOME TIME
TO COME. THIS GENERAL LONGWAVE PATTERN IS STRONGLY SUPPORTED BY ALL
MEDIUM RANGE ENSEMBLE PACKAGES AS WELL AS CPC FORECASTS OF
HEMISPHERIC PROCESSES...LIKE THE NAO AND PNA. MORE ON THIS IN THE
LONG RANGE DISCUSSION BELOW. NOW FOCUSING IN ON THE DETAILS...
A COLD FRONT WILL MARCH ACROSS OUR FORECAST AREA ON THURSDAY...
WITH WIDESPREAD SHOWERS AND POSSIBLY A FEW EMBEDDED THUNDERSTORMS
EXPECTED AS A RESULT. THE GUIDANCE PACKAGES HAVE BEEN DEPICTING A
PROGRESSIVELY EARLIER ONSET OF PCPN FOR THE PAST SEVERAL RUNS...AND
IT SEEMS AS IF THIS IS TIED DIRECTLY TO THE SPEED AND PLACEMENT OF
THE FAVORABLE UPPER LEVEL LIFT SUPPLIED BY A 100KT H25 JET OVER
WESTERN QUEBEC. A 3 TO 5 HOUR PERIOD OF SHOWERS WILL BE ASSOCIATED
WITH THE LIFT FOUND WITHIN THE RR ENTRANCE REGION OF THIS JET...
WITH LINGERING SHOWERS FOUND BACK IN THE VCNTY OF THE LOW LEVEL
FORCING NEAR THE FRONT. THIS WILL BOIL DOWN TO THE BULK OF THE
SHOWERS COMING DURING THE MORNING HOURS FOR THE WRN COUNTIES...AND
DURING THE MIDDAY FOR SITES EAST OF LK ONTARIO. THE SHOWERS WILL
THUS QUICKLY TAPER OFF FROM WEST TO EAST DURING THE COURSE OF THE
AFTERNOON. HAVE RAISED POPS TO 90 REGIONWIDE WITH BASIN AVERAGE QPF
RANGING FROM A QUARTER TO A HALF INCH.
BY THURSDAY EVENING...THE PLUME OF DEEP MOISTURE AHEAD OF THE
FRONT WILL BE RACING ACROSS NEW ENGLAND WHILE THE ACTUAL SFC FRONT
WILL ONLY BE SLOWLY MAKING ITS WAY ACROSS THE EASTERN LAKE ONTARIO
REGION. THIS WILL KEEP THE LIKELIHOOD FOR SOME SHOWERS OVER THE
EASTERN FINGER LAKES AND FOR SITES EAST OF LK ONTARIO...WITH JUST
SPOTTY LIGHT SHOWERS POSSIBLE UNDER A PASSING SHORTWAVE ACROSS THE
WRN COUNTIES. THE TREND WILL DEFINTIELY BE TOWARDS DRIER WEATHER
THOUGH AS LOW LEVEL RIDGING WILL BUILD EAST FROM LOWER MICHIGAN AND
THE OHIO VALLEY.
ANOTHER ISSUE TO KEEP AN EYE ON WILL BE MARGINALLY FAVORABLE
CONDITIONS FOR NUISANCE LAKE EFFECT DURING THE WEE HOURS OF
FRIDAY MORNING. H85 TEMPS ARE FORECAST TO DROP TO AROUND 10C BY
DAYBREAK...AND WITH LK SFC TEMPS IN THE VCNTY OF 22C...THAT WOULD
ONLY SUPPORT WEAK INSTABILITY. THERE WILL ALSO BE LIMITED SYNOPTIC
MOISTURE TO WORK WITH...SO WILL CONTINUE SLGT CHC POPS EAST OF LK
ERIE AND LOW CHC POPS EAST OF LK ONTARIO FOR ANY MINOR LAKE
RESPONSE.
ON FRIDAY AND FRIDAY NIGHT...A SERIES OF WEAK SHORT WAVES WILL
ROTATE THROUGH THE BASE OF THE UPPER LEVEL TROUGH THAT WILL BE
FIRMLY ESTABLISHED OVER THE GREAT LAKES. WHILE THE VAST MAJORITY OF
THIS 24 HOUR PERIOD SHOULD BE RAIN FREE...SCATTERED LIGHT SHOWERS
WILL BE POSSIBLE. THE COMBINATION OF LATE SUMMER HEATING DURING THE
MIDDAY/AFTERNOON WILL COMBINE WITH A SEASONABLY COOL AIRMASS TO
GENERATE LOW LEVEL LAPSE RATES OF 9-10 DEG C/KM...AND THIS ALONG
WITH THE FORCING FROM THE AFOREMENTIONED SHORTWAVE SHOULD BE ENOUGH
TO SUPPORT CHC POPS THROUGH THE EVENING HOURS. THE OVERNIGHT SHOULD
LARGELY BE RAIN FREE...WITH ONLY CHC POPS EAST OF LK ONTARIO FOR
SOME LAKE EFFECT. TEMPS FRIDAY WILL AVERAGE ABOUT 5 DEG F BELOW
NORMAL WITH AFTERNOON HIGHS GENERALLY IN THE MID 70S.
SATURDAY SHOULD BE A FAIRLY NICE DAY...ALBEIT IT SEASONABLY COOL AS
SFC HIGH PRESSURE CENTERED OVER THE CANADIAN PRAIRIES WILL BUILD
SOUTHEAST ACROSS ALL OF THE GREAT LAKES. THIS SHOULD ENCOURAGE
PARTIAL SUNSHINE ACROSS THE REGION WITH H85 TEMPS HOLDING MAX TEMPS
IN THE LOW TO MID 70S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
ALL OF THE THE MEDIUM RANGE ENSEMBLES REMAIN IN STRONG AGREEMENT
THAT THE DEEP...UPPER LEVEL TROUGH WILL HOLD IN PLACE ACROSS EASTERN
NORTH AMERICA THROUGH MUCH IF NOT ALL OF NEXT WEEK. THIS SCENARIO
WILL GUARANTEE THAT WE WILL CONTINUE TO EXPERIENCE BELOW NORMAL
TEMPERATURES...ALTHOUGH NOT ANOMALOUSLY SO AS MERCURY LEVELS WILL
GENERALLY AVERAGING 3-5 DEG F BELOW NORMAL.
IN TERMS OF PCPN...THE BULK OF THIS TIME PERIOD WILL BE RAINFREE.
BESIDES THE LOW CHC FOR NUISANCE LAKE SHOWERS SOUTHEAST OF LK
ONTARIO...CANADIAN HIGH PRESSURE BUILDING ACROSS THE LOWER GREAT
SHOULD PROVIDE THE REGION WITH DRY WEATHER SUNDAY AND MONDAY. THE
ECMWF HAS BECOME THE OUTLIER ON SUNDAY IN THAT IT SUGGESTS THAT A
VIGOROUS SHORTWAVE WILL GENERATE SOME SHOWERS...BUT THIS IS A NEW
SOLUTION AND ONE THAT IS NOT SUPPORTED BY OTHER PACKAGES.
THE POTENTIAL FOR A FAIRLY POTENT SHORTWAVE AND ASSOCIATED SFC WAVE
TO PASS THROUGH THE REGION ON TUESDAY WILL NECESSITATE THE
INTRODUCTION OF CHC POPS.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERED OVER NY AND PA WILL MAINTAIN VFR CONDITIONS
ACROSS MOST OF THE AREA EARLY THIS MORNING. THE MAIN EXCEPTION WILL
BE ACROSS THE SOUTHERN TIER VALLEYS WHERE RADIATIONAL COOLING MAY
RESULT IN IFR VSBYS IN FOG AT TIMES. THE PRESENCE OF HIGH LEVEL
CLOUDS WILL LIKELY LIMIT THE EXTENT OF THE IFR CONDITIONS.
EXPECT THE VALLEY FOG TO BURN OFF BY MID MORNING. AFTER THIS...MID
AND HIGH LEVEL CLOUDS WILL SPREAD EAST ACROSS THE AREA IN ADVANCE OF
THE NEXT SYSTEM.
OUTLOOK...
THURSDAY...VFR/MVFR WITH SHOWERS AND A FEW SCATTERED THUNDERSTORMS
PRODUCING ASSOCIATED BRIEF IFR.
FRIDAY AND SATURDAY...MAINLY VFR WITH A SMALL CHANCE OF SHOWERS.
SUNDAY...VFR.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL REMAIN IN PLACE ACROSS THE
LOWER LAKES TODAY AND TONIGHT. AFTER A FRONT CROSSES THE LAKES ON
THURSDAY...THE WINDS WILL SWITCH TO THE SOUTHWEST AND PICK UP A
BIT...BUT CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. MORE IMPORTANTLY...THE FRONT WILL BRING A GOOD
CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS TONIGHT AND
THURSDAY...WITH LOCAL INCREASES IN WIND AND WAVES POSSIBLE.
THE PRESSURE GRADIENT BETWEEN BETWEEN A SURFACE HIGH OVER THE MIDDLE
ATLANTIC STATES AND LOW PRESSURE PUSHING ACROSS HUDSON BAY WILL
CAUSE WESTERLY WINDS TO PICK UP A LITTLE MORE ON FRIDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TJP
NEAR TERM...TJP
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...TJP
MARINE...TJP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
947 PM EDT THU AUG 1 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT THEN STALL
AND DISSIPATE OVER THE AREA ON FRIDAY. HIGH PRESSURE OFFSHORE WILL
THEN DOMINATE INTO THE FIRST PART OF THE WEEKEND. ANOTHER COLD
FRONT WILL APPROACH FROM THE NORTHWEST SUNDAY AND MOVE SOUTH OF
THE AREA BY MONDAY AS HIGH PRESSURE BUILDS ACROSS THE AREA. THE
HIGH WILL DRIFT OFFSHORE TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 945 PM THURSDAY...ADDITIONAL SHOWERS HAVE DEVELOPED OVER THE
EASTERN PORTION OF THE PIEDMONT AND ARE MOVING INTO OUR WESTERN
CWA AS MID-LEVEL SHORTWAVE...VISIBLE ON LATEST WATER VAPOR IMAGERY
CONTINUES TO MOVE EAST. HAVE KEPT A SLIGHT CHC POP AREA-WIDE IN
THE FORECAST THROUGH ABOUT 06Z WITH THE LOW POPS MOVING TOWARD THE
COAST THROUGH THE EARLY MORNING HOURS BEFORE MOVING OFFSHORE BY
DAYBREAK. CLEARING SKIES AND WET GROUND MAY LEAD TO SOME PATCHY
FOG LATE BUT A LIGHT SSW LOW LEVEL FLOW SHUD KEEP WIDESPREAD DENSE
FOG AT BAY. LOW TEMPS WILL BE TYPICAL OF SUMMERTIME...MAINLY 70-75
COOLEST INLAND.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
WEATHER CONDITIONS MORE TYPICAL OF SUMMER RETURN FOR FRIDAY AS MID
LEVEL FLOW BECOMES MORE ZONAL. CUD SEE AN ISOLATED SHOWER OR
TSTORM ALONG THE SEABREEZE AND REMNANT WEAK SFC TROF OVER THE AREA
DURING THE AFTERNOON BUT MOST AREAS WILL BE DRY AND WARM. HIGHS
MAINLY IN THE UPPER 80S/NEAR 90 INLAND...MID 80S BEACHES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM THU...A BROAD UPPER TROF WILL REMAIN IN PLACE OVER THE
EASTERN US THROUGH THE MIDDLE OF NEXT WEEK FOLLOWED BY A RETURN TO
ZONAL FLOW. THIS UPPER TROF WILL ALLOW FOR AN UNSETTLED PATTERN TO
CONTINUE THROUGH MOST OF THE PERIOD. THE LONG TERM WILL START OUT
WITH THE REMNANTS OF A WEAK FRONT OVER THE MIDDLE OF THE STATE.
POPS WILL BE IN THE 20-30% RANGE WITH MOST OF THE ACTIVITY BEING
SEABREEZE-DRIVEN. ANY CONVECTION THAT DEVELOPS WILL DISSIPATE
QUICKLY SATURDAY EVENING. POPS RE-ENTER THE FORECAST AREA FROM THE
NORTH AFTER MIDNIGHT SATURDAY NIGHT AS A RATHER STRONG COLD FRONT
DROPS RAPIDLY SOUTH. THE FRONT WILL ENTER FROM THE NORTH SUNDAY
MORNING AND CONTINUE MOVING QUICKLY SOUTH DURING THE DAY. EXPECT
CONVECTION TO END IN THE FAR NORTH IN THE AFTERNOON AND THE
SOUTHERN COUNTIES BY LATE AFTERNOON. THE FRONT WILL HAVE A STRONG
PUSH BEHIND IT WITH GOOD LIFT AND CONVERGENCE ALONG AND AHEAD OF
THE BOUNDARY. A FEW STRONG STORMS COULD DEVELOP WITH STRONG GUSTY
WINDS THE MAIN THREAT. WINDEX VALUES FROM GFS/NAM/ECMWF FORECAST
SOUNDINGS AT 18Z SUNDAY ARE 45-50 KNOTS. A BRIEF PERIOD OF DRIER
AIR WILL SPREAD IN BEHIND THE FRONT SUNDAY NIGHT AND MONDAY WITH A
NORTH TO NORTHEAST WIND FLOW. THE POST FRONTAL HIGH WILL MOVE OFF
THE COAST ON TUESDAY WITH A SOUTHWEST FLOW RETURNING. THE FRONTAL
BOUNDARY WILL BE STATIONARY NOT FAR TO THE SOUTH THROUGH MOST OF
THE WEEK. THERE WILL BE A CHANCE OF SHOWERS/STORMS EACH
DAY...MAINLY THE SCATTERED AFTERNOON/EVENING VARIETY.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH 18Z FRIDAY/
AS OF 650 PM THURSDAY...SHOWERS WILL CONTINUE TO DIMINISH IN
COVERAGE OVERNIGHT...BUT WITH A RATHER MOIST GROUND...DO EXPECT
SOME PERIODS OF MVFR/IFR CEILINGS IN STRATUS AND SOME PATCHES OF
AT LEAST MVFR FOG TOWARD MORNING. FOG AND STRATUS SHOULD DISSIPATE
FAIRLY QUICKLY AFTER DAYBREAK FRIDAY WITH VFR CONDITIONS TO
PREVAIL THROUGH THE DAY...AS THE RISK OF LATE DAY CONVECTION WILL
BE MINIMAL.
LONG TERM /FRI NIGHT THROUGH TUE/ AS OF 3 PM
THU...SCATTERED CONVECTION POSSIBLE EACH DAY. SOUTHWEST WINDS
FRIDAY NIGHT THROUGH SUNDAY MORNING. A FRONT WILL DROP SOUTH
THROUGH THE AREA ON SUNDAY WITH WINDS SHIFTING QUICKLY FROM
SOUTHWEST TO NORTH. SCATTERED STRONG STORMS POSSIBLE ALONG AND
AHEAD OF THE FRONT WITH SURFACE WIND GUSTS AS HIGH AS 50 KNOTS.
NORTH TO NORTHEAST WIND AND DRY WEATHER FORECAST FOR SUNDAY NIGHT
INTO MONDAY. WINDS BECOME SOUTHWEST ONCE AGAIN ON TUESDAY WITH THE
CHANCE OF AFTERNOON & EVENING CONVECTION.
&&
.MARINE...
SHORT TERM /THROUGH FRIDAY/
AS OF 945 PM THURSDAY...WINDS HAVE SHOWN AN UPTICK OVER THE PAST
COUPLE OF HOURS AND HAVE BASICALLY 15 TO 20 KNOTS OVER MOST WATERS
PER THE LATEST RAP WIND FORECAST. THE BUOY 30 MILES SOUTHEAST OF
NEW RIVER INLET IS REPORTING 6 FOOT SEAS AND WAVE MODELS HAVE BEEN
CONSISTENT IN BUILDING 6+ FT SEAS IN RESPONSE TO THE INCREASING
S/SW WIND OVER CENTRAL AND SOUTHERN WATERS. THE SMALL CRAFT
ADVISORY REMAINS IN EFFECT UNTIL 6 AM SOUTH OF OCRACOKE AND UNTIL
8 AM FROM OCRACOKE UP TO OREGON INLET. WINDS GRADUALLY
DIMINISHING AND BECOMING MORE WSW LATE TONIGHT AND EARLY FRIDAY AS
GRADIENT SLACKENS WITH SEAS LIKELY FALLING BLO 6 FT BY SUNRISE
FRIDAY. SW WINDS WILL AGAIN INCREASE MODERATELY FRIDAY AFTN IN
RESPONSE TO INLAND THERMAL TROF BUT REMAINING BLO 15 KT. SEAS
MAINLY 2-4 FT FRIDAY.
LONG TERM /FRI NIGHT THROUGH TUE/
AS OF 3 PM THU...SOUTHWEST FLOW WILL CONTINUE FRIDAY NIGHT INTO
SUNDAY MORNING. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT.
WINDS NO HIGHER THAN 10-15 KNOTS AND SEAS NO HIGHER THAN 3-5
FEET. A COLD FRONT ENTERS THE REGION FROM THE NORTH AND THE
PRESSURE GRADIENT TIGHTENS SATURDAY NIGHT. WINDS WILL BE 10-15
KNOTS THROUGHOUT...EXCEPT FOR OREGON INLET TO OCRACOKE WITH 15-20
KNOTS. THE FRONT WILL DROP QUICKLY THROUGH THE MARINE AREA DURING
THE DAY SUNDAY WITH A QUICK VEERING TO NORTH AS IT PASSES. EXPECT
THIS WIND SHIFT TO OCCUR AROUND MIDDAY IN THE NORTHERN WATERS AND
LATE IN THE AFTERNOON IN THE SOUTHERN WATERS. SOME STRONG STORMS
COULD DEVELOP ALONG AND AHEAD OF THE FRONT ON SUNDAY WITH GUSTY
SURFACE WINDS UP TO 50 KNOTS. LIGHT NORTH TO NORTHEAST FLOW
FORECAST SUNDAY NIGHT INTO MONDAY WITH HIGH PRESSURE TO THE NORTH
AND A LOOSE PRESSURE GRADIENT. THE HIGH WILL MOVE OFF THE COAST
MONDAY NIGHT WITH A SOUTHERLY FLOW SETTING UP ONCE AGAIN. WINDS
AND SEAS WILL BE VERY LIGHT WITH SPEEDS 5-10 KNOTS AND SEAS 2-4
FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT FRIDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC
SHORT TERM...BTC
LONG TERM...HSA
AVIATION...CTC/HSA/BM
MARINE...CTC/BTC/HSA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 AM EDT WED JUL 31 2013
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL CROSS THE REGION FROM THE
WEST TODAY. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST ON
THURSDAY...THEN STALL OUT OVER THE EASTERN CAROLINAS ON FRIDAY.
&&
.NEAR TERM /TONIGHT/...
AS OF 950 PM TUESDAY...
A STATIONARY FRONT REMAINS DRAPED ACROSS EASTERN NC/SC AND EXTENDS
WEST ACROSS GA/AL...WITH WEAK HIGH PRESSURE NOW CENTERED OVER
SOUTHEAST VA. THE FEW SHOWERS AND STORMS IN THE VICINITY OF THE
FRONT HAVE REMAINED NEAR THE COAST THIS EVENING. UPSTREAM...A FAIRLY
PRONOUNCED VORT MAX IS MOVING ACROSS CENTRAL TN...WITH A LARGE AREA
OF MOSTLY STRATIFORM PRECIP OUT AHEAD OF IT...REACHING AS FAR EAST
AS KNOXVILLE. SOME MID/HIGH-LEVEL MOISTENING OVER WESTERN NC CAN BE
SEEN IN THE 00Z KGSO RAOB AND A LARGE VEIL OF CLOUD COVER JUST
REACHING THE WESTERN PIEDMONT. HOWEVER...THERE IS STILL QUITE A BIT
OF DRY AIR BETWEEN 600-800MB AND RAP SOUNDINGS ACTUALLY MAINTAIN
THIS LAYER OF DRY AIR THROUGH THE NIGHT AND INTO WEDNESDAY MORNING.
THE MOST RECENT RUNS OF THE HRRR SUGGEST VERY LIGHT PRECIP OVER THE
WESTERN PIEDMONT AFTER 09-10Z...WHICH MAY END UP JUST BEING
SPRINKLES OR LIGHT RAIN. BASED ON THIS...WILL REMOVE THE MENTION OF
THUNDER FROM THE FORECAST THROUGH MID-MORNING. DEWPOINTS HAVE
SURGED BACK INTO THE UPPER 60S AND LOWER 70S OVER MUCH OF THE
CWA...AND COMBINED WITH INCREASING MID/HIGH CLOUDS...FORECAST LOWS
MOSTLY IN THE UPPER 60S AND LOWER 70S APPEAR ON TRACK.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 240 PM TUESDAY...
MCS-INDUCED VORT MAX WILL MOVE ACROSS THE AREA ON WEDNESDAY...WITH
CONTINUED MOISTURE RETURN IN STRENGTHENING SOUTHWEST FLOW AHEAD OF
THE MID LEVEL SYSTEM. INSTABILITY WILL BE MARGINAL WITH WEAK
SHEAR...SBCAPE ~500J AND MID LEVEL LAPSE RATES ~5C/KM...BUT THE
VIGOROUS MID LEVEL VORT WILL BE SUPPORTED BY SOME UPPER DIFFLUENCE
WITH A 55-60KT UPPER JET EXITING THE AREA. POP WISE...WILL INTRODUCE
POPS IN THE WEST TOMORROW MORNING...WITH CONVECTION BECOMING LIKELY
ACROSS CENTRAL NC WITH THE TRANSLATION OF THE MID LEVEL SYSTEM AND
DIURNAL INSTABILITY CYCLE. HIGHS WILL BE HAMPERED BY CLOUDINESS...
ESPECIALLY IN THE WEST...WITH LOWER 80S WEST TO SOME UPPER 80S IN
THE EAST WHERE PRECIP WILL BE SLOWER TO ARRIVE.
WE REMAIN IN THE A FAVORABLE MOISTURE ADVECTION REGIME WITH DEEP
SOUTHWEST FLOW TOMORROW NIGHT WITH CYCLONIC FLOW ALOFT. POP CHANCES
WILL REMAIN IN THE HIGH CHANCE TO LIKELY RANGE WITH ONLY SMALL
CHANCES FOR THUNDER GIVEN A LULL IN MID LEVEL DISTURBANCES. MINS
WILL BE MILD GIVEN THE SOUTHERLY FLOW AND CLOUDINESS...68-72.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...
THE MODELS ARE IN VERY GOOD OVERALL AGREEMENT IN THE MEAN MID/UPPER
FLOW PATTERN AND THE RESULTANT SURFACE REFLECTIONS FRIDAY THROUGH
TUESDAY. A MEAN UPPER TROUGH WILL REMAIN ESTABLISHED FROM THE GREAT
LAKES SOUTHWARD THROUGH THE TENNESSEE VALLEY EASTWARD TO THE EASTERN
SEABOARD. THIS WILL KEEP TEMPERATURES IN CHECK FOR THE
CLIMATOLOGICALLY HOTTEST TIME OF THE YEAR. WE WILL ALSO SEE A COUPLE
OF COLD FRONTS THAT WILL BRING ENHANCED CHANCES OF SHOWERS AND
THUNDERSTORMS. NO BIG CHANGE NEEDED TO THE CURRENT FORECAST. THE
HIGHLIGHTS INCLUDE... DRY WEATHER AND BELOW NORMAL TEMPS FRI
AFTERNOON THROUGH SATURDAY. LOWS 63-68. HIGHS MID TO UPPER 80S.
A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS/STORMS SUNDAY INTO
MONDAY. DRIER AGAIN LATER MONDAY INTO TUESDAY. THEN ANOTHER FRONT
WITH A CHANCE OF CONVECTION AGAIN LATER TUE-WED.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 AM WEDNESDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREVAIL THIS MORNING GIVEN WIDESPREAD
CLOUD COVER AND A RELATIVELY LOW LIKELIHOOD OF SUB-VFR FOG OR
STRATUS DEVELOPMENT. LIGHT SHOWER ACTIVITY PROGRESSING EAST INTO THE
FOOTHILLS/PIEDMONT MAY RESULT IN PERIODIC LIGHT RAIN AT THE INT/GSO
TERMINALS THIS MORNING...THOUGH CEILINGS AND VISBYS ARE LIKELY TO
REMAIN VFR. ALTHOUGH SHOWER/THUNDERSTORM ACTIVITY IS EXPECTED TO BE
PRESENT THIS AFT/EVE AND TONIGHT...UNCERTAINTY IS GREATER THAN
NORMAL WITH REGARD TO THE LOCATION/TIMING/COVERAGE OF SUCH
ACTIVITY...AND AT THIS TIME WILL SIMPLY MENTION VCSH AT ALL
TERMINALS.
LOOKING AHEAD:
EXPECT AN INCREASING POTENTIAL FOR SUB-VFR CEILINGS BY SUNRISE THU
MORNING...ALONG WITH A CONTINUED CHANCE FOR SHOWERS AND
THUNDERSTORMS THU INTO THU NIGHT AT ALL TERMINALS AS A WEAK COLD
FRONT APPROACHES FROM THE W/NW. RELATIVELY DRIER AND VFR CONDITIONS
ARE EXPECTED FRI AS THE FRONT STALLS IN THE EASTERN CAROLINAS...
THOUGH CHANCES FOR PRIMARILY AFT/EVE SHOWERS AND STORMS WILL
INCREASE OVER THE WEEKEND AS YET ANOTHER FRONT APPROACHES THE REGION
FROM THE NORTH. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...BLS
SHORT TERM...MLM
LONG TERM...BADGETT
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
201 AM EDT WED JUL 31 2013
.SYNOPSIS...
A SERIES OF UPPER LEVEL DISTURBANCES WILL CROSS THE REGION FROM THE
WEST TODAY. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST ON
THURSDAY...THEN STALL OUT OVER THE EASTERN CAROLINAS ON FRIDAY.
&&
.NEAR TERM /TONIGHT/...
AS OF 950 PM TUESDAY...
A STATIONARY FRONT REMAINS DRAPED ACROSS EASTERN NC/SC AND EXTENDS
WEST ACROSS GA/AL...WITH WEAK HIGH PRESSURE NOW CENTERED OVER
SOUTHEAST VA. THE FEW SHOWERS AND STORMS IN THE VICINITY OF THE
FRONT HAVE REMAINED NEAR THE COAST THIS EVENING. UPSTREAM...A FAIRLY
PRONOUNCED VORT MAX IS MOVING ACROSS CENTRAL TN...WITH A LARGE AREA
OF MOSTLY STRATIFORM PRECIP OUT AHEAD OF IT...REACHING AS FAR EAST
AS KNOXVILLE. SOME MID/HIGH-LEVEL MOISTENING OVER WESTERN NC CAN BE
SEEN IN THE 00Z KGSO RAOB AND A LARGE VEIL OF CLOUD COVER JUST
REACHING THE WESTERN PIEDMONT. HOWEVER...THERE IS STILL QUITE A BIT
OF DRY AIR BETWEEN 600-800MB AND RAP SOUNDINGS ACTUALLY MAINTAIN
THIS LAYER OF DRY AIR THROUGH THE NIGHT AND INTO WEDNESDAY MORNING.
THE MOST RECENT RUNS OF THE HRRR SUGGEST VERY LIGHT PRECIP OVER THE
WESTERN PIEDMONT AFTER 09-10Z...WHICH MAY END UP JUST BEING
SPRINKLES OR LIGHT RAIN. BASED ON THIS...WILL REMOVE THE MENTION OF
THUNDER FROM THE FORECAST THROUGH MID-MORNING. DEWPOINTS HAVE
SURGED BACK INTO THE UPPER 60S AND LOWER 70S OVER MUCH OF THE
CWA...AND COMBINED WITH INCREASING MID/HIGH CLOUDS...FORECAST LOWS
MOSTLY IN THE UPPER 60S AND LOWER 70S APPEAR ON TRACK.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 240 PM TUESDAY...
MCS-INDUCED VORT MAX WILL MOVE ACROSS THE AREA ON WEDNESDAY...WITH
CONTINUED MOISTURE RETURN IN STRENGTHENING SOUTHWEST FLOW AHEAD OF
THE MID LEVEL SYSTEM. INSTABILITY WILL BE MARGINAL WITH WEAK
SHEAR...SBCAPE ~500J AND MID LEVEL LAPSE RATES ~5C/KM...BUT THE
VIGOROUS MID LEVEL VORT WILL BE SUPPORTED BY SOME UPPER DIFFLUENCE
WITH A 55-60KT UPPER JET EXITING THE AREA. POP WISE...WILL INTRODUCE
POPS IN THE WEST TOMORROW MORNING...WITH CONVECTION BECOMING LIKELY
ACROSS CENTRAL NC WITH THE TRANSLATION OF THE MID LEVEL SYSTEM AND
DIURNAL INSTABILITY CYCLE. HIGHS WILL BE HAMPERED BY CLOUDINESS...
ESPECIALLY IN THE WEST...WITH LOWER 80S WEST TO SOME UPPER 80S IN
THE EAST WHERE PRECIP WILL BE SLOWER TO ARRIVE.
WE REMAIN IN THE A FAVORABLE MOISTURE ADVECTION REGIME WITH DEEP
SOUTHWEST FLOW TOMORROW NIGHT WITH CYCLONIC FLOW ALOFT. POP CHANCES
WILL REMAIN IN THE HIGH CHANCE TO LIKELY RANGE WITH ONLY SMALL
CHANCES FOR THUNDER GIVEN A LULL IN MID LEVEL DISTURBANCES. MINS
WILL BE MILD GIVEN THE SOUTHERLY FLOW AND CLOUDINESS...68-72.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 250 PM TUESDAY...
OVERALL THE LONG TERM PERIOD WILL CONTINUE TO FEATURE A MEAN TROUGH
ACROSS THE EASTERN CONUS WITH A SERIES OF SHORTWAVES/WEAK FRONTS
PROGRESSING THROUGH THE AREA. THIS SET-UP WILL KEEP THE SUMMER HEAT
AT BAY WHILE PROVIDING PERIODS OF INCREASED SHOWER AND THUNDERSTORM
ACTIVITY.
PRECIP ASSOCIATED WITH THE NEXT UPPER TROUGH/SURFACE FRONT SHOULD BE
ONGOING TO START THE DAY ON THURSDAY. ALTHOUGH THE ACTUAL FRONT WILL
LIKELY NOT MOVE THROUGH THE AREA UNTIL LATE IN THE DAY...THE
PREFRONTAL TROUGH...HEATING (ALTHOUGH EXTENSIVE CLOUD COVER SHOULD
KEEP TEMPS DOWN SOME) AND ANY WEAK DISTURBANCES ALOFT SHOULD PROVIDE
ENOUGH OF A TRIGGER FOR CONVECTION VIRTUALLY ANYWHERE IN THE
FORECAST AREA. THEN AS THE FRONT MOVES THROUGH LATER IN THE DAY AND
INTO THE EVENING HOURS...PRECIP SHOULD TRANSLATE FROM WEST TO EAST.
ALTHOUGH WIDESPREAD SEVERE STORMS ARE NOT EXPECTED...WITH INCREASING
SHEAR AND POCKETS OF HIGHER INSTABILITY (DIFFERENTIAL HEATING FROM
ANY BREAKS IN THE CLOUDS)...AN ISOLATED STRONG TO SEVERE STORM
CANNOT BE RULED OUT. PRECIP SHOULD END FROM WEST TO EAST THURSDAY
NIGHT INTO FRIDAY MORNING.
BY FRIDAY...THE FRONT SHOULD STALL/WASH OUT SOMEWHERE NEAR THE
REGION. OVERALL...THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH PUSHING
IT SOUTH/EAST OF THE FORECAST AREA WHICH WOULD RESULT IN MOSTLY DRY
CONDITIONS FOR CENTRAL NC...WHILE THE GFS HAS SLOWER WITH THE
EASTWARD PROGRESSION (ALTHOUGH THE 12Z RUN OF THE GFS HAS COME MORE
IN LINE WITH THE ECMWF). NEVERTHELESS...GIVEN THE TIME OF THE YEAR
AND THE SIMILARITY TO RECENT EVENTS...WILL MAINTAIN AT LEAST A
MENTION OF PRECIP FOR FRIDAY AND SATURDAY...ESPECIALLY ON FRIDAY AND
MOSTLY ACROSS THE EASTERN/SOUTHERN PORTIONS OF THE FORECAST AREA.
THIS PATTERN WE ARE IN WILL CONTINUE AS YET ANOTHER SYSTEM WILL
APPROACH THE AREA LATE IN THE WEEKEND/EARLY NEXT WEEK (ALTHOUGH
TIMING REMAINS IN QUESTION). LATEST INDICATIONS SHOW PRECIP RAMPING
BACK UP LATE SATURDAY INTO SUNDAY...WITH EARLY NEXT WEEK DRYING OUT
AS THE FRONT SHIFTS/STALLS SOMEWHERE SOUTH/EAST OF THE FORECAST AREA
(ALTHOUGH AS CAN BE EXPECTED THIS FAR OUT...THIS IS TIMING SUBJECT
CHANGE.
TEMPS WILL ULTIMATELY BE DEPENDENT ON THE EXACT TIMING/EXTENT OF ANY
PRECIP THAT OCCURS...BUT SHOULD LARGELY BE NEAR TO SLIGHTLY BELOW
NORMAL THROUGH THE PERIOD.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 200 AM WEDNESDAY...
24-HR TAF PERIOD:
VFR CONDITIONS ARE EXPECTED TO PREVAIL THIS MORNING GIVEN WIDESPREAD
CLOUD COVER AND A RELATIVELY LOW LIKELIHOOD OF SUB-VFR FOG OR
STRATUS DEVELOPMENT. LIGHT SHOWER ACTIVITY PROGRESSING EAST INTO THE
FOOTHILLS/PIEDMONT MAY RESULT IN PERIODIC LIGHT RAIN AT THE INT/GSO
TERMINALS THIS MORNING...THOUGH CEILINGS AND VISBYS ARE LIKELY TO
REMAIN VFR. ALTHOUGH SHOWER/THUNDERSTORM ACTIVITY IS EXPECTED TO BE
PRESENT THIS AFT/EVE AND TONIGHT...UNCERTAINTY IS GREATER THAN
NORMAL WITH REGARD TO THE LOCATION/TIMING/COVERAGE OF SUCH
ACTIVITY...AND AT THIS TIME WILL SIMPLY MENTION VCSH AT ALL
TERMINALS.
LOOKING AHEAD:
EXPECT AN INCREASING POTENTIAL FOR SUB-VFR CEILINGS BY SUNRISE THU
MORNING...ALONG WITH A CONTINUED CHANCE FOR SHOWERS AND
THUNDERSTORMS THU INTO THU NIGHT AT ALL TERMINALS AS A WEAK COLD
FRONT APPROACHES FROM THE W/NW. RELATIVELY DRIER AND VFR CONDITIONS
ARE EXPECTED FRI AS THE FRONT STALLS IN THE EASTERN CAROLINAS...
THOUGH CHANCES FOR PRIMARILY AFT/EVE SHOWERS AND STORMS WILL
INCREASE OVER THE WEEKEND AS YET ANOTHER FRONT APPROACHES THE REGION
FROM THE NORTH. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...BLS
SHORT TERM...MLM
LONG TERM...KRR
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1208 PM CDT WED JUL 31 2013
.UPDATE...
ISSUED AT 1208 PM CDT WED JUL 31 2013
LATEST VISIBLE IMAGERY SHOWS SCATTERED CUMULUS CLOUDS EMBEDDED WITHIN
THE NORTHWEST FLOW...WITH AN ISOLATED AREA OF BROKEN CLOUDS SEEN NEAR
THE BISMARCK/MANDAN AREA. THE FORECAST REMAINS ON TRACK THIS AFTERNOON
WITH MOSTLY SUNNY SKIES. ONLY MINOR UPDATES TO HOURLY TEMPERATURES.
UPDATE ISSUED AT 901 AM CDT WED JUL 31 2013
LATEST VISIBLE SATELLITE IMAGERY SHOWS A SCT TO BKN CUMULUS FIELD
FROM NEAR CROSBY TO STANLEY AND INTO GARRISON...ASSOCIATED WITH A
COLD POCKET IN THE H85-H7 LAYER. THIS WILL CONTINUE TO MOVE
SOUTHEAST INTO THE JAMES RIVER VALLEY AS THE MID AND UPPER LEVEL
WINDS WINDS ARE NORTHWEST. WATER VAPOR IMAGERY SHOWS THE NEXT
SHORTWAVE NOW OVER NORTHWEST SASKATCHEWAN MOVING SOUTHEAST WITH
TIME. IT IS FORECAST TO SHIFT NEAR SASKATOON AROUND 00Z
THURSDAY...WITH SOME SPOTTY SHOWERS REACHING AS FAR SOUTH AS
BRANDON MANITOBA. AN ISOLATED SHOWER COULD CLIP THE TURTLE
MOUNTAINS EARLY THIS EVENING BUT NOT MUCH MORE THAN THAT.
MAIN ADJUSTMENT TO THE GRIDS THIS MORNING IS TO INCREASE SKY
COVER TO ACCOUNT FOR THE CUMULUS DECK...AS SOUNDINGS AND CROSS
SECTIONS SHOW WE WILL REMAIN NEARLY DRY ADIABATIC INTO THE
SHALLOW MOIST/COLDER H85-H7 LAYER. MIXING INTO DRIER AIR ALOFT
THIS AFTERNOON WILL LIMIT COVERAGE AND VERTICAL EXTENT.
UPDATE ISSUED AT 639 AM CDT WED JUL 31 2013
UPDATED THE FORECAST TO REMOVE FIRST PERIOD POPS FROM THE
SOUTHWESTERN ZONES BASED ON CURRENT RADAR OBS/TRENDS. FOR THE
SOUTHEASTERN ZONES...CHANGED PRECIPITATION WORDING TO COVERAGE
TERMINOLOGY TO BETTER REFLECT THE CURRENT CONDITIONS. THE
CONVECTIVE ACTIVITY SHOULD BE OUT OF THE SOUTHERN JAMES RIVER
BASIN IN THE NEXT FEW HOURS.
FURTHERMORE...ADDED PATCHY FOG WORDING AROUND DICKINSON GIVEN THE
LIGHT WINDS AND REDUCED VISIBILITIES HAVING BEEN REPORTED THERE FOR
ABOUT AN HOUR NOW. THINK VISIBILITIES WILL IMPROVE IN THE NEXT
HOUR OR SO WHEN VERTICAL MIXING COMMENCES.
THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED
GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT WED JUL 31 2013
MAIN FORECAST CONCERN WILL BE SHOWER AND THUNDERSTORM COVERAGE IN
THE NEAR TERM. LATEST RADAR AT 0818 UTC SHOWS THAT THE SCATTERED
SHOWER AND THUNDERSTORM ACTIVITY GRADUALLY SHIFTING TO THE SOUTH
AND EAST. THUNDERSTORMS ARE EXPECTED TO REMAIN SUB-SEVERE...PER THE
08 UTC SPC MESOANALYSIS...AS ML AND MU CAPE ARE MINIMAL EVEN
THOUGH 50 KTS OF 0-6 KM SHEAR IS PRESENT. THE 06 UTC HRRR AND 07
UTC RAP BOTH CONTINUE THE TREND OF MOVING SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH AND EAST...WITH ALL ACTIVITY COMING TO AN
END ACROSS THE SOUTH CENTRAL BETWEEN 13 TO 15 UTC.
FOR TODAY AND TONIGHT...NORTHWEST FLOW WILL PREVAIL
ALLOWING FOR DRY AND QUIET WEATHER TO TAKE HOLD AS HIGH PRESSURE
MOVES OVER THE REGION. COOLER THAN TEMPERATURES ARE EXPECTED WITH
HIGHS GENERALLY IN THE 70S AND LOWS IN THE UPPER 40S TO MID 50S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 347 AM CDT WED JUL 31 2013
THE MEDIUM RANGE MODELS ARE STILL IN FAIRLY GOOD AGREEMENT WITH
PERSISTENT NORTHWESTERLY FLOW ALOFT OVER WESTERN AND CENTRAL NORTH
DAKOTA THROUGH THE PERIOD. THIS PATTERN WILL MAINTAIN BELOW NORMAL
TEMPERATURES ACROSS THE STATE THROUGH THE FIRST WEEK IN AUGUST.
NORTHWEST FLOW IS ALSO NOTORIOUS FOR LOW PREDICTABILITY WAVES
YIELDING THE POTENTIAL FOR ISOLATED CONVECTION NEARLY EVERY DAY.
HOWEVER...THE BEST CHANCES FOR WIDESPREAD PRECIPITATION LOOK TO BE
SATURDAY THROUGH SUNDAY AS THE PACIFIC NORTHWEST UPPER LOW
PROPAGATES ALONG THE CREST OF THE RIDGE INTO THE NORTHERN PLAINS.
THUNDERSTORMS SHOULD REMAIN BELOW SEVERE LIMITS GIVEN THE WEAK
INSTABILITY PROGGED DURING THE WEEKEND. HOWEVER...WILL CONTINUE TO
MONITOR TRENDS AND ADJUST THE FORECAST AS NEEDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1208 PM CDT WED JUL 31 2013
VFR CIGS/VSBYS NEXT 24HR. SCT CUMULUS CLOUDS WILL CONTINUE THROUGH
SUNSET WITH CLEARING SKIES COMMENCING THEREAFTER.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...LTH
LONG TERM...TM
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
904 AM CDT WED JUL 31 2013
.UPDATE...
ISSUED AT 901 AM CDT WED JUL 31 2013
LATEST VISIBLE SATELLITE IMAGERY SHOWS A SCT TO BKN CUMULUS FIELD
FROM NEAR CROSBY TO STANLEY AND INTO GARRISON...ASSOCIATED WITH A
COLD POCKET IN THE H85-H7 LAYER. THIS WILL CONTINUE TO MOVE
SOUTHEAST INTO THE JAMES RIVER VALLEY AS THE MID AND UPPER LEVEL
WINDS WINDS ARE NORTHWEST. WATER VAPOR IMAGERY SHOWS THE NEXT
SHORTWAVE NOW OVER NORTHWEST SASKATCHEWAN MOVING SOUTHEAST WITH
TIME. IT IS FORECAST TO SHIFT NEAR SASKATOON AROUND 00Z
THURSDAY...WITH SOME SPOTTY SHOWERS REACHING AS FAR SOUTH AS
BRANDON MANITOBA. AN ISOLATED SHOWER COULD CLIP THE TURTLE
MOUNTAINS EARLY THIS EVENING BUT NOT MUCH MORE THAN THAT.
MAIN ADJUSTMENT TO THE GRIDS THIS MORNING IS TO INCREASE SKY
COVER TO ACCOUNT FOR THE CUMULUS DECK...AS SOUNDINGS AND CROSS
SECTIONS SHOW WE WILL REMAIN NEARLY DRY ADIABATIC INTO THE
SHALLOW MOIST/COLDER H85-H7 LAYER. MIXING INTO DRIER AIR ALOFT
THIS AFTERNOON WILL LIMIT COVERAGE AND VERTICAL EXTENT.
UPDATE ISSUED AT 639 AM CDT WED JUL 31 2013
UPDATED THE FORECAST TO REMOVE FIRST PERIOD POPS FROM THE
SOUTHWESTERN ZONES BASED ON CURRENT RADAR OBS/TRENDS. FOR THE
SOUTHEASTERN ZONES...CHANGED PRECIPITATION WORDING TO COVERAGE
TERMINOLOGY TO BETTER REFLECT THE CURRENT CONDITIONS. THE
CONVECTIVE ACTIVITY SHOULD BE OUT OF THE SOUTHERN JAMES RIVER
BASIN IN THE NEXT FEW HOURS.
FURTHERMORE...ADDED PATCHY FOG WORDING AROUND DICKINSON GIVEN THE
LIGHT WINDS AND REDUCED VISIBILITIES HAVING BEEN REPORTED THERE FOR
ABOUT AN HOUR NOW. THINK VISIBILITIES WILL IMPROVE IN THE NEXT
HOUR OR SO WHEN VERTICAL MIXING COMMENCES.
THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED
GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT WED JUL 31 2013
MAIN FORECAST CONCERN WILL BE SHOWER AND THUNDERSTORM COVERAGE IN
THE NEAR TERM. LATEST RADAR AT 0818 UTC SHOWS THAT THE SCATTERED
SHOWER AND THUNDERSTORM ACTIVITY GRADUALLY SHIFTING TO THE SOUTH
AND EAST. THUNDERSTORMS ARE EXPECTED TO REMAIN SUB-SEVERE...PER THE
08 UTC SPC MESOANALYSIS...AS ML AND MU CAPE ARE MINIMAL EVEN
THOUGH 50 KTS OF 0-6 KM SHEAR IS PRESENT. THE 06 UTC HRRR AND 07
UTC RAP BOTH CONTINUE THE TREND OF MOVING SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH AND EAST...WITH ALL ACTIVITY COMING TO AN
END ACROSS THE SOUTH CENTRAL BETWEEN 13 TO 15 UTC.
FOR TODAY AND TONIGHT...NORTHWEST FLOW WILL PREVAIL
ALLOWING FOR DRY AND QUIET WEATHER TO TAKE HOLD AS HIGH PRESSURE
MOVES OVER THE REGION. COOLER THAN TEMPERATURES ARE EXPECTED WITH
HIGHS GENERALLY IN THE 70S AND LOWS IN THE UPPER 40S TO MID 50S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 347 AM CDT WED JUL 31 2013
THE MEDIUM RANGE MODELS ARE STILL IN FAIRLY GOOD AGREEMENT WITH
PERSISTENT NORTHWESTERLY FLOW ALOFT OVER WESTERN AND CENTRAL NORTH
DAKOTA THROUGH THE PERIOD. THIS PATTERN WILL MAINTAIN BELOW NORMAL
TEMPERATURES ACROSS THE STATE THROUGH THE FIRST WEEK IN AUGUST.
NORTHWEST FLOW IS ALSO NOTORIOUS FOR LOW PREDICTABILITY WAVES
YIELDING THE POTENTIAL FOR ISOLATED CONVECTION NEARLY EVERY DAY.
HOWEVER...THE BEST CHANCES FOR WIDESPREAD PRECIPITATION LOOK TO BE
SATURDAY THROUGH SUNDAY AS THE PACIFIC NORTHWEST UPPER LOW
PROPAGATES ALONG THE CREST OF THE RIDGE INTO THE NORTHERN PLAINS.
THUNDERSTORMS SHOULD REMAIN BELOW SEVERE LIMITS GIVEN THE WEAK
INSTABILITY PROGGED DURING THE WEEKEND. HOWEVER...WILL CONTINUE TO
MONITOR TRENDS AND ADJUST THE FORECAST AS NEEDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 639 AM CDT WED JUL 31 2013
IFR/LIFR VSBYS IN MIST/FOG OVER KDIK SHOULD IMPROVE TO VFR AFTER
14Z AS SURFACE TEMPERATURES INCREASE. OTHERWISE...VFR CONDITIONS
WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE
REMAINDER OF THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...LTH
LONG TERM...TM
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
639 AM CDT WED JUL 31 2013
.UPDATE...
ISSUED AT 639 AM CDT WED JUL 31 2013
UPDATED THE FORECAST TO REMOVE FIRST PERIOD POPS FROM THE
SOUTHWESTERN ZONES BASED ON CURRENT RADAR OBS/TRENDS. FOR THE
SOUTHEASTERN ZONES...CHANGED PRECIPITATION WORDING TO COVERAGE
TERMINOLOGY TO BETTER REFLECT THE CURRENT CONDITIONS. THE
CONVECTIVE ACTIVITY SHOULD BE OUT OF THE SOUTHERN JAMES RIVER
BASIN IN THE NEXT FEW HOURS.
FURTHERMORE...ADDED PATCHY FOG WORDING AROUND DICKINSON GIVEN THE
LIGHT WINDS AND REDUCED VISIBILITIES HAVING BEEN REPORTED THERE FOR
ABOUT AN HOUR NOW. THINK VISIBILITIES WILL IMPROVE IN THE NEXT
HOUR OR SO WHEN VERTICAL MIXING COMMENCES.
THE REMAINING WEATHER ELEMENTS ARE IN GOOD SHAPE. THE UPDATED
GRIDDED AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT WED JUL 31 2013
MAIN FORECAST CONCERN WILL BE SHOWER AND THUNDERSTORM COVERAGE IN
THE NEAR TERM. LATEST RADAR AT 0818 UTC SHOWS THAT THE SCATTERED
SHOWER AND THUNDERSTORM ACTIVITY GRADUALLY SHIFTING TO THE SOUTH
AND EAST. THUNDERSTORMS ARE EXPECTED TO REMAIN SUB-SEVERE...PER THE
08 UTC SPC MESOANALYSIS...AS ML AND MU CAPE ARE MINIMAL EVEN
THOUGH 50 KTS OF 0-6 KM SHEAR IS PRESENT. THE 06 UTC HRRR AND 07
UTC RAP BOTH CONTINUE THE TREND OF MOVING SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH AND EAST...WITH ALL ACTIVITY COMING TO AN
END ACROSS THE SOUTH CENTRAL BETWEEN 13 TO 15 UTC.
FOR TODAY AND TONIGHT...NORTHWEST FLOW WILL PREVAIL
ALLOWING FOR DRY AND QUIET WEATHER TO TAKE HOLD AS HIGH PRESSURE
MOVES OVER THE REGION. COOLER THAN TEMPERATURES ARE EXPECTED WITH
HIGHS GENERALLY IN THE 70S AND LOWS IN THE UPPER 40S TO MID 50S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 347 AM CDT WED JUL 31 2013
THE MEDIUM RANGE MODELS ARE STILL IN FAIRLY GOOD AGREEMENT WITH
PERSISTENT NORTHWESTERLY FLOW ALOFT OVER WESTERN AND CENTRAL NORTH
DAKOTA THROUGH THE PERIOD. THIS PATTERN WILL MAINTAIN BELOW NORMAL
TEMPERATURES ACROSS THE STATE THROUGH THE FIRST WEEK IN AUGUST.
NORTHWEST FLOW IS ALSO NOTORIOUS FOR LOW PREDICTABILITY WAVES
YIELDING THE POTENTIAL FOR ISOLATED CONVECTION NEARLY EVERY DAY.
HOWEVER...THE BEST CHANCES FOR WIDESPREAD PRECIPITATION LOOK TO BE
SATURDAY THROUGH SUNDAY AS THE PACIFIC NORTHWEST UPPER LOW
PROPAGATES ALONG THE CREST OF THE RIDGE INTO THE NORTHERN PLAINS.
THUNDERSTORMS SHOULD REMAIN BELOW SEVERE LIMITS GIVEN THE WEAK
INSTABILITY PROGGED DURING THE WEEKEND. HOWEVER...WILL CONTINUE TO
MONITOR TRENDS AND ADJUST THE FORECAST AS NEEDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 639 AM CDT WED JUL 31 2013
IFR/LIFR VSBYS IN MIST/FOG OVER KDIK SHOULD IMPROVE TO VFR AFTER
14Z AS SURFACE TEMPERATURES INCREASE. OTHERWISE...VFR CONDITIONS
WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE
REMAINDER OF THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...LTH
LONG TERM...TM
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
347 AM CDT WED JUL 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CDT WED JUL 31 2013
MAIN FORECAST CONCERN WILL BE SHOWER AND THUNDERSTORM COVERAGE IN
THE NEAR TERM. LATEST RADAR AT 0818 UTC SHOWS THAT THE SCATTERED
SHOWER AND THUNDERSTORM ACTIVITY GRADUALLY SHIFTING TO THE SOUTH
AND EAST. THUNDERSTORMS ARE EXPECTED TO REMAIN SUB-SEVERE...PER THE
08 UTC SPC MESOANALYSIS...AS ML AND MU CAPE ARE MINIMAL EVEN
THOUGH 50 KTS OF 0-6 KM SHEAR IS PRESENT. THE 06 UTC HRRR AND 07
UTC RAP BOTH CONTINUE THE TREND OF MOVING SHOWER AND THUNDERSTORM
ACTIVITY TO THE SOUTH AND EAST...WITH ALL ACTIVITY COMING TO AN
END ACROSS THE SOUTH CENTRAL BETWEEN 13 TO 15 UTC.
FOR TODAY AND TONIGHT...NORTHWEST FLOW WILL PREVAIL
ALLOWING FOR DRY AND QUIET WEATHER TO TAKE HOLD AS HIGH PRESSURE
MOVES OVER THE REGION. COOLER THAN TEMPERATURES ARE EXPECTED WITH
HIGHS GENERALLY IN THE 70S AND LOWS IN THE UPPER 40S TO MID 50S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 347 AM CDT WED JUL 31 2013
THE MEDIUM RANGE MODELS ARE STILL IN FAIRLY GOOD AGREEMENT WITH
PERSISTENT NORTHWESTERLY FLOW ALOFT OVER WESTERN AND CENTRAL NORTH
DAKOTA THROUGH THE PERIOD. THIS PATTERN WILL MAINTAIN BELOW NORMAL
TEMPERATURES ACROSS THE STATE THROUGH THE FIRST WEEK IN AUGUST.
NORTHWEST FLOW IS ALSO NOTORIOUS FOR LOW PREDICTABILITY WAVES
YIELDING THE POTENTIAL FOR ISOLATED CONVECTION NEARLY EVERY DAY.
HOWEVER...THE BEST CHANCES FOR WIDESPREAD PRECIPITATION LOOK TO BE
SATURDAY THROUGH SUNDAY AS THE PACIFIC NORTHWEST UPPER LOW
PROPAGATES ALONG THE CREST OF THE RIDGE INTO THE NORTHERN PLAINS.
THUNDERSTORMS SHOULD REMAIN BELOW SEVERE LIMITS GIVEN THE WEAK
INSTABILITY PROGGED DURING THE WEEKEND. HOWEVER...WILL CONTINUE TO
MONITOR TRENDS AND ADJUST THE FORECAST AS NEEDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 112 AM CDT WED JUL 31 2013
AT 1 AM CDT...SHOWER AND THUNDERSTORM COVERAGE HAS INCREASED
SOUTH OF INTERSTATE 94 AS A WEAK COLD FRONTAL BOUNDARY CONTINUES
TO SLIDE SOUTH. HAVE INTRODUCED VCTS AT KDIK AND KBIS THROUGH 08Z.
ACTIVITY SHOULD DIMINISH OVER THE NEXT FEW HOURS...WITH VFR
CONDITIONS PREVAILING AT ALL SITES...EXCEPT FOR MVFR CONDITIONS IN
THUNDERSTORMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LTH
LONG TERM...TM
AVIATION...LTH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
350 PM EDT WED JUL 31 2013
.SYNOPSIS...
A WEAK COLD FRONT CROSSES LATE TONIGHT AND EARLY THURSDAY. HIGH
PRESSURE PASSES THURSDAY NIGHT/FRIDAY MORNING. A COLD FRONT CROSSES
THIS WEEKEND...FOLLOWED BY BELOW NORMAL TEMPERATURES EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
DISTURBANCE MOVING THRU CWA WITH MAINLY SCT -SHRA AND EVEN SOME
-DZ ABOUT THE AREA. WEAKENING VORT MAX HANGING OUT ACROSS SE OH CO
WITH LOBE APPENDAGE MOVING NE INTO N WV SERVING AS MAIN FOCUS FOR
LIFT. RUC AND HRRR SEEMS TO HAVE A MUCH BETTER HANDLE ON THINGS VS
OTHER MDLS AND HAVE USED THESE AS GUIDANCE. OTHERWISE LOOKING AT
AN ABUNDANCE OF LLVL MOISTURE REMAINDER OF AFTN.
FRONT POISED TO MOVE THRU LATE TONIGHT INTO EARLY THU MORNING WITH
A BAND OF SHRA WITH IT. THERE COULD BE AN AREA OF -RA OR DZ ALONG
AND E OF I79 TONIGHT BEFORE AFOREMENTIONED SHRA ARRIVE WITH
IMPRESSIVE DRYING SHOWING UP IN MID LVLS. THINK LOW STRATUS AND
FG WILL SETUP REGARDLESS THIS EVE...TRYING TO LIFT SOME AS FRONTAL
SHRA MOVE IN PREDAWN.
ALL OF THIS PUSHES E ON THU WITH AMPLIFYING UPR TROF ACROSS OH
VALLEY. HOWEVER...LLVL MOISTURE WILL BE VERY SLOW TO GIVE UP THE
GHOST. EVEN THOUGH LOW STRATUS LIFTS BY MIDDAY...SUSPECT THIS WILL
GIVE WAY TO AN ABUNDANCE OF CU GIVEN H85 MOISTURE UNDERNEATH A
DEVELOPING STOUT INVERSION ARND H7. AS FOR POPS DRY THINGS OUT FOR
MOST PART. DID LEAVE SOME LOW POPS FOR A FEW EARLY AFTN DEVELOPMENT
ACROSS THE MTNS.
FOR TEMPS...INHERITED NUMBERS LOOKED GOOD TONIGHT. ELECTED TO GO
CLOSER TO COOLER MET ON THU WITH EXPECTATION THAT EXTENT OF CLDS
HOLDS NUMBERS DOWN A BIT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
A FEW OF THE MESO MODELS ARE SHOWING SOME LINGERING SHOWERS BEHIND
THE COLD FRONT THURSDAY NIGHT. DUE TO THE TIME OF DAY AND DRY AIR
PUSH...DO NOT THINK THAT THIS IS REALISTIC. WILL LEAVE DRY FOR NOW.
HIGH PRESSURE THEN PROVIDES A BRIEF PERIOD OF DRY WEATHER FRIDAY
MORNING. ALL MODELS ARE SHOWING SOME MOISTURE PUSHING BACK IN LATE
FRIDAY...ALTHOUGH TIMING DIFFERENCES EXIST. WILL INCLUDE A CHANCE OF
SHOWERS...AND POSSIBLY THUNDERSTORMS...BUT NOT BE TOO DEFINITIVE. WILL
INCREASE POPS INTO SATURDAY AS FRONT APPROACHES AND MOISTURE
DEEPENS. FRONT THEN PUSHES THROUGH LATE SATURDAY/SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LOTS OF MODEL DIFFERENCES IN HOW FAR SOUTH THE FRONT AND MOISTURE
PUSH FOR THE END OF THE WEEKEND AND BEGINNING OF NEXT WEEK. USED A
BLEND OF THE ECMWF MEAN AND THE GEFS...WHICH WOULD PUT THE FRONT
JUST SOUTH OF THE FORECAST AREA. WITH SOME WAVES POSSIBLE ALONG THE
FRONT...SOME PRECIPITATION COULD MAKE IT INTO THE FORECAST
AREA...WITH THE BEST CHANCES IN THE SOUTH.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
18Z WEDNESDAY THRU 18Z THURSDAY...
UPR LVL DISTURBANCE SLOWLY PUSH NE THRU AREA THIS AFTN WITH SCT
SHRA AND EVEN PATCHY DZ. THINK KCRW...KBKW...KEKN STAND BEST CHC
OF SEEING PCPN AND THUS HAVE THOSE TERMINALS IN MVFR VSBY IN SHRA
THIS AFTN. OTHERWISE GENERALLY LOOKING AT MVFR CIGS SAVE ACROSS SE
OH AND N WV LOWLANDS. THESE WILL LWR TONIGHT INTO MAINLY IFR CIGS
WITH MVFR ACROSS SE OH/N LOWLANDS. HAVE SOME IFR VSBY COMBO FG
WHERE IT HAS RAINED. KEKN MAY SEE CIGS LWR INTO LIFR.
SLOW MOVING COLD FRONT APPROACHES AFTER 10Z WITH SOME SHRA. THESE
SHOULD ALLOW CIGS AND VSBY TO IMPROVE BY DAWN. FRONT MOVES E OF
AREA THU MORNING. LLVL MOISTURE WILL LINGER THOUGH...BENEATH A
DEVELOPING INVERSION...WHICH WILL DELAY IMPROVEMENT OF CIGS. THINK
LOW STRATUS LIFTS INTO MVFR ABUNDANCE OF CU BY AFTN. ANY LINGERING
SHRA ACROSS THE MTNS SHOULD END IN AFTN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: DEVELOPMENT OF LOW STRATUS/FOG AFTER 00Z MAY
VARY FROM CURRENT FORECAST. TIMING OF FRONT AND SHRA TONIGHT MAY
VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H M M M M M M M H H H
HTS CONSISTENCY M M M M M M H H H H H H
BKW CONSISTENCY M M M M M M H H H M M M
EKN CONSISTENCY H H M M M M M M M H H H
PKB CONSISTENCY H H H H H H H H H M M M
CKB CONSISTENCY H H H H H H H H H M M H
AFTER 18Z THURSDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS LATE FRIDAY THROUGH
SATURDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...RPY
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
230 PM EDT WED JUL 31 2013
.SYNOPSIS...
A WEAK COLD FRONT CROSSES LATE TONIGHT AND EARLY THURSDAY. HIGH
PRESSURE PASSES FRIDAY MORNING. A COLD FRONT CROSSES THIS
WEEKEND...FOLLOWED BY HIGH PRESSURE SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH THURSDAY/...
DISTURBANCE MOVING THRU CWA WITH MAINLY SCT -SHRA AND EVEN SOME
-DZ ABOUT THE AREA. WEAKENING VORT MAX HANGING OUT ACROSS SE OH CO
WITH LOBE APPENDAGE MOVING NE INTO N WV SERVING AS MAIN FOCUS FOR
LIFT. RUC AND HRRR SEEMS TO HAVE A MUCH BETTER HANDLE ON THINGS VS
OTHER MDLS AND HAVE USED THESE AS GUIDANCE. OTHERWISE LOOKING AT
AN ABUNDANCE OF LLVL MOISTURE REMAINDER OF AFTN.
FRONT POISED TO MOVE THRU LATE TONIGHT INTO EARLY THU MORNING WITH
A BAND OF SHRA WITH IT. THERE COULD BE AN AREA OF -RA OR DZ ALONG
AND E OF I79 TONIGHT BEFORE AFOREMENTIONED SHRA ARRIVE WITH
IMPRESSIVE DRYING SHOWING UP IN MID LVLS. THINK LOW STRATUS AND
FG WILL SETUP REGARDLESS THIS EVE...TRYING TO LIFT SOME AS FRONTAL
SHRA MOVE IN PREDAWN.
ALL OF THIS PUSHES E ON THU WITH AMPLIFYING UPR TROF ACROSS OH
VALLEY. HOWEVER...LLVL MOISTURE WILL BE VERY SLOW TO GIVE UP THE
GHOST. EVEN THOUGH LOW STRATUS LIFTS BY MIDDAY...SUSPECT THIS WILL
GIVE WAY TO AN ABUNDANCE OF CU GIVEN H85 MOISTURE UNDERNEATH A
DEVELOPING STOUT INVERSION ARND H7. AS FOR POPS DRY THINGS OUT FOR
MOST PART. DID LEAVE SOME LOW POPS FOR A FEW EARLY AFTN DEVELOPMENT
ACROSS THE MTNS.
FOR TEMPS...INHERITED NUMBERS LOOKED GOOD TONIGHT. ELECTED TO GO
CLOSER TO COOLER MET ON THU WITH EXPECTATION THAT EXTENT OF CLDS
HOLDS NUMBERS DOWN A BIT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
SHORT WAVE TROUGH EXITS FIRST THING IN THE MORNING...TAKING THE DEEP
LAYER MOISTURE AND THE LAST OF THE SIGNIFICANT RAINFALL WITH IT. A
SECOND SHORT WAVE TROUGH SETTLES INTO THE AREA LATE THU AFTER A WEAK
COLD FRONT CROSSES...LITTLE FORCING ASSOCIATED WITH EITHER AND NOT A
LOT OF MOISTURE TO WORK WITH OUTSIDE THE LOW LEVELS. WILL LIKELY
SEE A MURKY SOUGHT OF DAY WITH STRATUS AND FOG IN THE MORNING GIVING
WAY TO SOME SUNSHINE IN THE AFTERNOON ALONG WITH LOW COVERAGE POP UP
SHOWERS / THUNDERSTORMS.
HIGH PRESSURE PASSES S OF THE AREA THU NT INTO FRI..LIKELY LEADING
TO DENSE RIVER VALLEY FOG EARLY FRI MORNING. ANOTHER SHORT WAVE
TROUGH IN NEARLY ZONAL FLOW ALOFT ARRIVES FRI NT IN THE WORLD OF THE
NAM...AND LOOKS SIMILAR TO THE ONE ARRIVING IN THE NEAR TERM. OTHER
MODELS ARE SLOWER AND / OR FLATTER WITH THIS FEATURE. FOR NOW DID
EXTEND THE EXISTING SMALL CHANCE FOR PRECIPITATION SAT BACK INTO FRI
NT.
TEMPERATURES LOOKED GOOD FOR THU AND THU NT. USED ADJMET TO RAISE
HIGHS A BIT FRI AND CONSALL FOR SAME ON LOWS FRI NT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
GENERALLY FOLLOWED WPC THINKING WITH SOME TWEAKS. HIGH PRESSURE
SHOULD PREVAIL AT THE BEGINNING OF THE PERIOD. ANOTHER COLD FRONT
WILL THEN PUSH SLOWLY SOUTHEAST WITH A CHANCE OF SHOWERS AND
STORMS SATURDAY INTO SUNDAY NIGHT. ANOTHER SYSTEM SHOULD BRING
MORE PRECIP CHANCES FOR EARLY NEXT WEEK.
TEMPERATURES SHOULD GENERALLY REMAIN SLIGHTLY BELOW NORMAL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
18Z WEDNESDAY THRU 18Z THURSDAY...
UPR LVL DISTURBANCE SLOWLY PUSH NE THRU AREA THIS AFTN WITH SCT
SHRA AND EVEN PATCHY DZ. THINK KCRW...KBKW...KEKN STAND BEST CHC
OF SEEING PCPN AND THUS HAVE THOSE TERMINALS IN MVFR VSBY IN SHRA
THIS AFTN. OTHERWISE GENERALLY LOOKING AT MVFR CIGS SAVE ACROSS SE
OH AND N WV LOWLANDS. THESE WILL LWR TONIGHT INTO MAINLY IFR CIGS
WITH MVFR ACROSS SE OH/N LOWLANDS. HAVE SOME IFR VSBY COMBO FG
WHERE IT HAS RAINED. KEKN MAY SEE CIGS LWR INTO LIFR.
SLOW MOVING COLD FRONT APPROACHES AFTER 10Z WITH SOME SHRA. THESE
SHOULD ALLOW CIGS AND VSBY TO IMPROVE BY DAWN. FRONT MOVES E OF
AREA THU MORNING. LLVL MOISTURE WILL LINGER THOUGH...BENEATH A
DEVELOPING INVERSION...WHICH WILL DELAY IMPROVEMENT OF CIGS. THINK
LOW STRATUS LIFTS INTO MVFR ABUNDANCE OF CU BY AFTN. ANY LINGERING
SHRA ACROSS THE MTNS SHOULD END IN AFTN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: DEVELOPMENT OF LOW STRATUS/FOG AFTER 00Z MAY
VARY FROM CURRENT FORECAST. TIMING OF FRONT AND SHRA TONIGHT MAY
VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H M M M M M M M H H H
HTS CONSISTENCY M M M M M M H H H H H H
BKW CONSISTENCY M M M M M M H H H M M M
EKN CONSISTENCY H H M M M M M M M H H H
PKB CONSISTENCY H H H H H H H H H M M M
CKB CONSISTENCY H H H H H H H H H M M H
AFTER 18Z THURSDAY...
POSSIBLE IFR IN POST-RAIN STRATUS AND FOG INTO THURSDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...30
SHORT TERM...TRM
LONG TERM...JSH
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1026 AM EDT WED JUL 31 2013
.SYNOPSIS...
LOW PRESSURE CROSSES TODAY. A WEAK COLD FRONT CROSSES THURSDAY.
HIGH PRESSURE PASSES FRIDAY MORNING. A COLD FRONT CROSSES THIS
WEEKEND...FOLLOWED BY HIGH PRESSURE SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...
DISTURBANCE MOVING THRU CWA ATTM WITH MAINLY SCT -SHRA AND EVEN
SOME -DZ ABOUT THE AREA. WEAKENING VORT MAX HANGING OUT ACROSS SE OH
CO WITH LOBE APPENDAGE MOVING NE INTO N WV SERVING AS MAIN FOCUS
FOR LIFT. RUC AND HRRR SEEMS TO HAVE A MUCH BETTER HANDLE ON
THINGS VS OTHER MDLS AND HAVE USED THESE AS GUIDANCE FOR THIS
UPDATE. WILL DECREASE POPS SIGNIFICANTLY WITH PASSAGE OF THIS VORT
LOBE...LINGERING ACROSS N MTNS. SE DOWNSLOPING FLOW ALSO SERVING
TO REALLY HAMPER THINGS THIS MORNING ACROSS THE LOWLANDS. HARD TO
SEE MUCH TO LATCH ON TO FOR FORCING THIS AFTN OUTSIDE OF MTNS BUT
WILL LEAVE A LOW POP IN. WOULD THINK THAT SOME OF THE LOW CLDS
WILL BREAK UP LATER THIS AFTN BUT ABUNDANT LLVL MOISTURE REMAINS
SO NOT EXPECTING MUCH IN THE WAY OF SUN.
PREVIOUS DISCUSSION FOLLOWS...
UNSETTLED WEATHER RETURNING TO THE AREA IN THE NEAR TERM. AT THE
SURFACE...HIGH PRESSURE CONTINUES TO SLIDE OFF TO THE EAST...AS A
LOW PRESSURE SYSTEM APPROACHES FROM THE WEST. SPLIT FLOW PATTERN
ALOFT OVER THE EASTERN U.S...WITH A SHORTWAVE AT 06Z PUSHING
SOUTHEAST OUT OF THE MIDWEST TOWARDS THE REGION...TO BE FOLLOWED BY
A SECONDARY SHORTWAVE WHICH WILL MOVE EAST TO NORTHEAST ACROSS THE
CWA DURING THE DAY. MODELS HAVE BACKED OFF SOMEWHAT ON QPF AMOUNTS
ACROSS THE CWA...AND INDICATE BULK OF MOISTURE/DYNAMICS SHOULD
REMAIN TO THE SOUTH AND EAST. PREVIOUS MODEL RUNS INDICATED PW
VALUES RISING TO AROUND 2 INCHES ACROSS THE CWA...BUT NOW INDICATE
VALUES OF GENERALLY AROUND 1.6 TO 1.7. WILL STILL BE HEAVIER
SHOWERS/STORMS AT TIMES TODAY...BUT THINK CWA WILL BE SPARED ANY
MAJOR WATER ISSUES...PARTICULARLY WITH 3 HR FFG ACROSS SOUTHERN AND
MOUNTAIN ZONES...WHERE HEAVIER PRECIPITATION AMOUNTS ARE
EXPECTED...ARE GENERALLY WELL OVER 2-3 INCHES IN THE 3 HOUR PERIOD.
BULK OF PRECIPITATION WILL TAPER OFF EARLY TONIGHT...BUT POST RAIN
FOG AND LOW STRATUS WILL BE THE RULE. KEPT OVERNIGHT LOW
TEMPERATURES ON THE WARM SIDE AS A RESULT. WILL CONTINUE TO MAINTAIN
A CHANCE FOR SHOWERS/STORMS ACROSS THE CWA IN THE OVERNIGHT
HOURS...AS ANOTHER UPPER SHORTWAVE TROUGH...AND SURFACE COLD FRONT
APPROACH THE CWA FROM THE WEST...WITH FRONT WINDING UP JUST TO THE
WEST OF THE CWA AT THE END OF THE PERIOD.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
SHORT WAVE TROUGH EXITS FIRST THING IN THE MORNING...TAKING THE DEEP
LAYER MOISTURE AND THE LAST OF THE SIGNIFICANT RAINFALL WITH IT. A
SECOND SHORT WAVE TROUGH SETTLES INTO THE AREA LATE THU AFTER A WEAK
COLD FRONT CROSSES...LITTLE FORCING ASSOCIATED WITH EITHER AND NOT A
LOT OF MOISTURE TO WORK WITH OUTSIDE THE LOW LEVELS. WILL LIKELY
SEE A MURKY SOUGHT OF DAY WITH STRATUS AND FOG IN THE MORNING GIVING
WAY TO SOME SUNSHINE IN THE AFTERNOON ALONG WITH LOW COVERAGE POP UP
SHOWERS / THUNDERSTORMS.
HIGH PRESSURE PASSES S OF THE AREA THU NT INTO FRI..LIKELY LEADING
TO DENSE RIVER VALLEY FOG EARLY FRI MORNING. ANOTHER SHORT WAVE
TROUGH IN NEARLY ZONAL FLOW ALOFT ARRIVES FRI NT IN THE WORLD OF THE
NAM...AND LOOKS SIMILAR TO THE ONE ARRIVING IN THE NEAR TERM. OTHER
MODELS ARE SLOWER AND / OR FLATTER WITH THIS FEATURE. FOR NOW DID
EXTEND THE EXISTING SMALL CHANCE FOR PRECIPITATION SAT BACK INTO FRI
NT.
TEMPERATURES LOOKED GOOD FOR THU AND THU NT. USED ADJMET TO RAISE
HIGHS A BIT FRI AND CONSALL FOR SAME ON LOWS FRI NT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
GENERALLY FOLLOWED WPC THINKING WITH SOME TWEAKS. HIGH PRESSURE
SHOULD PREVAIL AT THE BEGINNING OF THE PERIOD. ANOTHER COLD FRONT
WILL THEN PUSH SLOWLY SOUTHEAST WITH A CHANCE OF SHOWERS AND
STORMS SATURDAY INTO SUNDAY NIGHT. ANOTHER SYSTEM SHOULD BRING
MORE PRECIP CHANCES FOR EARLY NEXT WEEK.
TEMPERATURES SHOULD GENERALLY REMAIN SLIGHTLY BELOW NORMAL.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
12Z WEDNESDAY THRU 12Z THURSDAY...
PATCHY MVFR VALLEY FOG WILL BURN OFF AFTER 13Z.
CLOUDS THICKENING AND LOWERING IN ADVANCE OF AN APPROACHING LOW PRESSURE
SYSTEM...WHICH IS SPREADING SHOWERS THIS MORNING...AND THUNDERSTORMS
MAINLY AFTER 16Z...BACK INTO THE AREA. EXPECT LOCAL MVFR
CONDITIONS IN VICINITY OF SHOWERS/STORMS...WITH SOUTHERN WEST
VIRGINIA...EASTERN KENTUCKY...SOUTHWEST VA...AND MOUNTAINS OF WV
THE MOST FAVORED LOCATIONS FOR ACTIVITY.
AFTER 00Z...EXPECT WIDESPREAD IFR/LIFR CONDITIONS TO DEVELOP IN LOW
STRATUS AND CONTINUED SHOWER/ISOLD THUNDERSTORM ACTIVITY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND DEVELOPMENT OF MVFR CONDITIONS IN
SHOWERS AND STORMS MAY DIFFER FROM CURRENT FORECAST. DEVELOPMENT
OF LOW STRATUS AFTER 00Z MAY VARY FROM CURRENT FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H M M M M M M
HTS CONSISTENCY H H H H M M M M M M M M
BKW CONSISTENCY H H H H M M M M M M M M
EKN CONSISTENCY L H H H H H M M M M M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z THURSDAY...
POSSIBLE IFR IN POST-RAIN STRATUS AND FOG INTO THURSDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/SL
NEAR TERM...SL/30
SHORT TERM...TRM
LONG TERM...JSH
AVIATION...SL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
725 AM EDT WED JUL 31 2013
.SYNOPSIS...
A COLD FRONT ACROSS THE NORTHERN PLAINS WILL CONTINUE SOUTHEAST
TODAY AND DROP ACROSS THE AREA EARLY THURSDAY. WEAK HIGH PRESSURE
WILL BUILD IN ON FRIDAY AHEAD OF ANOTHER COLD FRONT THAT IS
EXPECTED ON SATURDAY. CANADIAN HIGH PRESSURE WILL BUILD IN SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...NO BIG CHANGES ALTHOUGH DID INCREASE POPS TO LIKELY
SOUTHWEST COUNTIES STARTING NOW.
PREVIOUS...HIGH PRESSURE...NOW EAST OF THE AREA WILL CONTINUE TO
LOOSE ITS GRIP ON THE AREA TODAY AS A SURFACE LOW OVER SOUTHERN
ILLINOIS MOVES THROUGH KENTUCKY BEFORE EXPANDING OVER OHIO. ALSO A
COLD FRONT OVER THE NORTHERN PLAINS WILL CONTINUE TO DROP
SOUTHEAST TOWARD THE AREA. FOLLOWING THE NAM80...THE MODEL SHOWS A
SHORT WAVE MOVING INTO THE AREA FROM THE WEST DURING THE MORNING
AND AFFECTING THE EAST HALF OF THE AREA THIS AFTERNOON. MOISTURE
WILL INCREASE ACROSS THE AREA THROUGH THE DAY AND THE HRRR SHOWS
PRECIP BREAKING OUT IN THE WEST EARLY WHICH AGREES WITH THE
CURRENT RADAR. NOT EXPECTING AN ALL DAY RAIN BUT WILL HAVE CHANCE
POPS INCREASING TO LIKELY IN THE WEST TODAY WITH POPS INCREASING
TO HIGH CHANCE EAST. WILL HAVE HIGH A DEGREE OR TWO BELOW GUIDANCE
GIVEN EXPECTED CLOUDS AND PRECIP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
TONIGHT LOOKING FOR PRECIP TO EXPAND ACROSS THE AREA AS COLD FRONT
APPROACHES FROM THE NORTHWEST AND MORE JET ENERGY DROP ACROSS THE
AREA. WILL HAVE CATEGORICAL POPS EAST AND LIKELY POPS WEST. WEAK
HIGH PRESSURE BUILDS IN FRIDAY SO WILL TAPER POPS WEST THROUGH THE
NIGHT INTO THURSDAY. WILL ALSO TAPER EAST BUT WILL HOLD ONTO A LOW
CHANCE POP TO COVER ANY LINGERING MOISTURE WITH THE AFTERNOON
INSTABILITY THAT DEVELOPS UNDER THE UPPER TROF. A BIT CONCERNED
ABOUT WESTERN COUNTIES FOR THE SAME REASON BUT FOR NOW WILL KEEP
DRY. FRIDAY AFTERNOON WILL BRING BACK CHANCE POPS AS SECOND COLD
FRONT APPROACHES FROM THE NORTHWEST. BOTH THE NAM AND GFS SHOW
SHORT WAVES DROPPING ACROSS THE AREA WITH THE MEAN TROUGH
REMAINING ACROSS THE GREAT LAKES AND OHIO VALLEY. CHANCE POPS WILL
CONTINUE FRIDAY NIGHT AND SATURDAY AS THE FRONT DROPS THROUGH. DRY
AIR AND BUILDING HIGH PRESSURE EXPECTED SATURDAY NIGHT. HIGHS
RATHER UNREMARKABLE FOR THIS TIME OF YEAR WITH MOST LOCATIONS ON
MOST DAYS LIKELY NOT GETTING OUT OF THE 70S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
NOT MUCH CHANGE GOING INTO NEXT WEEK. STILL MAINTAIN AN EASTERN U.S.
TROUGH AND THEREFORE TEMPERATURES THAT WILL BE RUNNING SLIGHTLY
BELOW NORMAL. THE UPPER TROUGH AXIS WILL BE EAST OF THE AREA SUNDAY
WITH SURFACE HIGH PRESSURE BUILDING IN ACROSS THE GREAT LAKES AND
OHIO VALLEY. NEXT MINOR UPPER WAVE RE-ENFORCING THE LONGWAVE
TROUGH...MAY BRING IN A FEW SHOWERS MONDAY NIGHT...GIVE OR TAKE A
LITTLE DUE TO TIMING IT THIS FAR OUT.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
SLOW MOVING AND WEAK SYSTEM TO CROSS THE AREA BETWEEN 12Z WED AND
12Z THU. ONE BATCH OF SHOWERS MOVING EAST ALONG AND SOUTH OF A
LINE FROM FDY/MFD/CAK. SOME AREAS OF MVFR VSBY WITHIN THE RAIN.
ANY SHOWERS AFTER THIS WAVE WILL LIKELY BE SPOTTY AND HIT OR MISS
SINCE THE NEXT FEATURE TO KICK OFF SHOWERS AND POSSIBLY A RUMBLE
OF THUNDER WILL BE MOVING IN FOR THIS EVENING/TONIGHT.
PREDOMINATELY VFR UP UNTIL THIS EVENING. LIGHT/VARIABLE TO LIGHT
SOUTH WINDS TODAY. ONLY HAVE MEDIUM CONFIDENCE IN TIMING OF
PRECIP FOR TONIGHT BUT COVERAGE LOOKS LIKELY. NON-VFR CONDITIONS
IN THE SHRA/TS AND THEN LOW END MVFR OR IFR CIGS A GOOD BET WITH
AND AFTER THE COLD FRONT FOR A TIME. IMPROVEMENT THURSDAY MORNING.
.OUTLOOK...AREAS OF NON-VFR EARLY THURSDAY AND POSSIBLY AGAIN
THURSDAY AFTERNOON IN SHRA.
&&
.MARINE...
IT WILL REMAIN RELATIVELY QUIET ON THE LAKE FOR THE NEXT FEW DAYS.
ONLY FEATURES OF NOTE ARE A WEAK COLD FRONT CROSSING THE LAKE
TONIGHT. THIS AFTERNOON WINDS WILL BE LIGHT/VARIABLE...BECOMING
LIGHT SOUTH AHEAD OF THE FRONT. A SHIFT TO THE WEST CAN BE EXPECTED
AFTER THE FRONT...BUT SPEEDS STILL LIGHT. A SECONDARY TROUGH CROSSES
THE LAKE THURSDAY NIGHT AND HIGH PRESSURE THEN BUILDS ACROSS THE
OHIO VALLEY FOR FRIDAY. ANOTHER WEAK COLD FRONT SLIPS ACROSS THE
LAKE SATURDAY. UNCERTAIN AS TO IF CONDITIONS WILL GET CHOPPY ENOUGH
FOR ANY SMALL CRAFT ADV CONDITIONS. GRADIENT SEEMS FAIRLY WEAK. THE
CHOPPIER CONDITIONS MAY ACTUALLY ARRIVE BRIEFLY SUNDAY AS THE HIGH
BUILDS IN. OBVIOUSLY THERE IS LOW CONFIDENCE YET.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
637 AM EDT WED JUL 31 2013
.SYNOPSIS...
A COLD FRONT ACROSS THE NORTHERN PLAINS WILL CONTINUE SOUTHEAST
TODAY AND DROP ACROSS THE AREA EARLY THURSDAY. WEAK HIGH PRESSURE
WILL BUILD IN ON FRIDAY AHEAD OF ANOTHER COLD FRONT THAT IS
EXPECTED ON SATURDAY. CANADIAN HIGH PRESSURE WILL BUILD IN SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...NO BIG CHANGES ALTHOUGH DID INCREASE POPS TO LIKELY
SOUTHWEST COUNTIES STARTING NOW.
PREVIOUS...HIGH PRESSURE...NOW EAST OF THE AREA WILL CONTINUE TO
LOOSE ITS GRIP ON THE AREA TODAY AS A SURFACE LOW OVER SOUTHERN
ILLINOIS MOVES THROUGH KENTUCKY BEFORE EXPANDING OVER OHIO. ALSO A
COLD FRONT OVER THE NORTHERN PLAINS WILL CONTINUE TO DROP
SOUTHEAST TOWARD THE AREA. FOLLOWING THE NAM80...THE MODEL SHOWS A
SHORT WAVE MOVING INTO THE AREA FROM THE WEST DURING THE MORNING
AND AFFECTING THE EAST HALF OF THE AREA THIS AFTERNOON. MOISTURE
WILL INCREASE ACROSS THE AREA THROUGH THE DAY AND THE HRRR SHOWS
PRECIP BREAKING OUT IN THE WEST EARLY WHICH AGREES WITH THE
CURRENT RADAR. NOT EXPECTING AN ALL DAY RAIN BUT WILL HAVE CHANCE
POPS INCREASING TO LIKELY IN THE WEST TODAY WITH POPS INCREASING
TO HIGH CHANCE EAST. WILL HAVE HIGH A DEGREE OR TWO BELOW GUIDANCE
GIVEN EXPECTED CLOUDS AND PRECIP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
TONIGHT LOOKING FOR PRECIP TO EXPAND ACROSS THE AREA AS COLD FRONT
APPROACHES FROM THE NORTHWEST AND MORE JET ENERGY DROP ACROSS THE
AREA. WILL HAVE CATEGORICAL POPS EAST AND LIKELY POPS WEST. WEAK
HIGH PRESSURE BUILDS IN FRIDAY SO WILL TAPER POPS WEST THROUGH THE
NIGHT INTO THURSDAY. WILL ALSO TAPER EAST BUT WILL HOLD ONTO A LOW
CHANCE POP TO COVER ANY LINGERING MOISTURE WITH THE AFTERNOON
INSTABILITY THAT DEVELOPS UNDER THE UPPER TROF. A BIT CONCERNED
ABOUT WESTERN COUNTIES FOR THE SAME REASON BUT FOR NOW WILL KEEP
DRY. FRIDAY AFTERNOON WILL BRING BACK CHANCE POPS AS SECOND COLD
FRONT APPROACHES FROM THE NORTHWEST. BOTH THE NAM AND GFS SHOW
SHORT WAVES DROPPING ACROSS THE AREA WITH THE MEAN TROUGH
REMAINING ACROSS THE GREAT LAKES AND OHIO VALLEY. CHANCE POPS WILL
CONTINUE FRIDAY NIGHT AND SATURDAY AS THE FRONT DROPS THROUGH. DRY
AIR AND BUILDING HIGH PRESSURE EXPECTED SATURDAY NIGHT. HIGHS
RATHER UNREMARKABLE FOR THIS TIME OF YEAR WITH MOST LOCATIONS ON
MOST DAYS LIKELY NOT GETTING OUT OF THE 70S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
NOT MUCH CHANGE GOING INTO NEXT WEEK. STILL MAINTAIN AN EASTERN U.S.
TROUGH AND THEREFORE TEMPERATURES THAT WILL BE RUNNING SLIGHTLY
BELOW NORMAL. THE UPPER TROUGH AXIS WILL BE EAST OF THE AREA SUNDAY
WITH SURFACE HIGH PRESSURE BUILDING IN ACROSS THE GREAT LAKES AND
OHIO VALLEY. NEXT MINOR UPPER WAVE RE-ENFORCING THE LONGWAVE
TROUGH...MAY BRING IN A FEW SHOWERS MONDAY NIGHT...GIVE OR TAKE A
LITTLE DUE TO TIMING IT THIS FAR OUT.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SLOW MOVING AND WEAK SYSTEM TO CROSS THE AREA BETWEEN 12Z WED AND
12Z THU. FOR THE REST OF THE OVERNIGHT HOURS...VFR. ANY LIGHT SHRA
DURING THE DAYLIGHT HOURS TODAY WILL BE SPOTTY AND HIT OR MISS.
CEILINGS WILL EVER SO SLOWLY LOWER...STAYING VFR THROUGH THE
AFTERNOON. THE BEST CHANCES OF SHRA AND POSSIBLY A RUMBLE OF THUNDER
ARRIVE THIS EVENING...ALONG WITH THE CHANCES OF NON-VFR WEATHER. THE
BEST DEFINED SURFACE FEATURE...A WEAK COLD FRONT WILL BE NEARING
TOL/FDY BY 06Z THU. MAY HAVE SOME NON-VFR CEILINGS BEHIND THIS
FRONT. WINDS WILL BE LIGHT/VARIABLE TO LIGHT SOUTH TODAY AND INTO
TONIGHT.
.OUTLOOK...AREAS OF NON-VFR POSSIBLE WEDNESDAY NIGHT AND THURSDAY.
&&
.MARINE...
IT WILL REMAIN RELATIVELY QUIET ON THE LAKE FOR THE NEXT FEW DAYS.
ONLY FEATURES OF NOTE ARE A WEAK COLD FRONT CROSSING THE LAKE
TONIGHT. THIS AFTERNOON WINDS WILL BE LIGHT/VARIABLE...BECOMING
LIGHT SOUTH AHEAD OF THE FRONT. A SHIFT TO THE WEST CAN BE EXPECTED
AFTER THE FRONT...BUT SPEEDS STILL LIGHT. A SECONDARY TROUGH CROSSES
THE LAKE THURSDAY NIGHT AND HIGH PRESSURE THEN BUILDS ACROSS THE
OHIO VALLEY FOR FRIDAY. ANOTHER WEAK COLD FRONT SLIPS ACROSS THE
LAKE SATURDAY. UNCERTAIN AS TO IF CONDITIONS WILL GET CHOPPY ENOUGH
FOR ANY SMALL CRAFT ADV CONDITIONS. GRADIENT SEEMS FAIRLY WEAK. THE
CHOPPIER CONDITIONS MAY ACTUALLY ARRIVE BRIEFLY SUNDAY AS THE HIGH
BUILDS IN. OBVIOUSLY THERE IS LOW CONFIDENCE YET.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
338 AM EDT WED JUL 31 2013
.SYNOPSIS...
A COLD FRONT ACROSS THE NORTHERN PLAINS WILL CONTINUE SOUTHEAST
TODAY AND DROP ACROSS THE AREA EARLY THURSDAY. WEAK HIGH PRESSURE
WILL BUILD IN ON FRIDAY AHEAD OF ANOTHER COLD FRONT THAT IS
EXPECTED ON SATURDAY. CANADIAN HIGH PRESSURE WILL BUILD IN SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE...NOW EAST OF THE AREA WILL CONTINUE TO LOOSE ITS
GRIP ON THE AREA TODAY AS A SURFACE LOW OVER SOUTHERN ILLINOIS
MOVES THROUGH KENTUCKY BEFORE EXPANDING OVER OHIO. ALSO A COLD
FRONT OVER THE NORTHERN PLAINS WILL CONTINUE TO DROP SOUTHEAST
TOWARD THE AREA. FOLLOWING THE NAM80...THE MODEL SHOWS A SHORT WAVE
MOVING INTO THE AREA FROM THE WEST DURING THE MORNING AND
AFFECTING THE EAST HALF OF THE AREA THIS AFTERNOON. MOISTURE WILL
INCREASE ACROSS THE AREA THROUGH THE DAY AND THE HRRR SHOWS PRECIP
BREAKING OUT IN THE WEST EARLY WHICH AGREES WITH THE CURRENT RADAR.
NOT EXPECTING AN ALL DAY RAIN BUT WILL HAVE CHANCE POPS INCREASING
TO LIKELY IN THE WEST TODAY WITH POPS INCREASING TO HIGH CHANCE
EAST. WILL HAVE HIGH A DEGREE OR TWO BELOW GUIDANCE GIVEN EXPECTED
CLOUDS AND PRECIP.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
TONIGHT LOOKING FOR PRECIP TO EXPAND ACROSS THE AREA AS COLD FRONT
APPROACHES FROM THE NORTHWEST AND MORE JET ENERGY DROP ACROSS THE
AREA. WILL HAVE CATEGORICAL POPS EAST AND LIKELY POPS WEST. WEAK
HIGH PRESSURE BUILDS IN FRIDAY SO WILL TAPER POPS WEST THROUGH THE
NIGHT INTO THURSDAY. WILL ALSO TAPER EAST BUT WILL HOLD ONTO A LOW
CHANCE POP TO COVER ANY LINGERING MOISTURE WITH THE AFTERNOON
INSTABILITY THAT DEVELOPS UNDER THE UPPER TROF. A BIT CONCERNED
ABOUT WESTERN COUNTIES FOR THE SAME REASON BUT FOR NOW WILL KEEP
DRY. FRIDAY AFTERNOON WILL BRING BACK CHANCE POPS AS SECOND COLD
FRONT APPROACHES FROM THE NORTHWEST. BOTH THE NAM AND GFS SHOW
SHORT WAVES DROPPING ACROSS THE AREA WITH THE MEAN TROUGH
REMAINING ACROSS THE GREAT LAKES AND OHIO VALLEY. CHANCE POPS WILL
CONTINUE FRIDAY NIGHT AND SATURDAY AS THE FRONT DROPS THROUGH. DRY
AIR AND BUILDING HIGH PRESSURE EXPECTED SATURDAY NIGHT. HIGHS
RATHER UNREMARKABLE FOR THIS TIME OF YEAR WITH MOST LOCATIONS ON
MOST DAYS LIKELY NOT GETTING OUT OF THE 70S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
NOT MUCH CHANGE GOING INTO NEXT WEEK. STILL MAINTAIN AN EASTERN U.S.
TROUGH AND THEREFORE TEMPERATURES THAT WILL BE RUNNING SLIGHTLY
BELOW NORMAL. THE UPPER TROUGH AXIS WILL BE EAST OF THE AREA SUNDAY
WITH SURFACE HIGH PRESSURE BUILDING IN ACROSS THE GREAT LAKES AND
OHIO VALLEY. NEXT MINOR UPPER WAVE RE-ENFORCING THE LONGWAVE
TROUGH...MAY BRING IN A FEW SHOWERS MONDAY NIGHT...GIVE OR TAKE A
LITTLE DUE TO TIMING IT THIS FAR OUT.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
SLOW MOVING AND WEAK SYSTEM TO CROSS THE AREA BETWEEN 12Z WED AND
12Z THU. FOR THE REST OF THE OVERNIGHT HOURS...VFR. ANY LIGHT SHRA
DURING THE DAYLIGHT HOURS TODAY WILL BE SPOTTY AND HIT OR MISS.
CEILINGS WILL EVER SO SLOWLY LOWER...STAYING VFR THROUGH THE
AFTERNOON. THE BEST CHANCES OF SHRA AND POSSIBLY A RUMBLE OF THUNDER
ARRIVE THIS EVENING...ALONG WITH THE CHANCES OF NON-VFR WEATHER. THE
BEST DEFINED SURFACE FEATURE...A WEAK COLD FRONT WILL BE NEARING
TOL/FDY BY 06Z THU. MAY HAVE SOME NON-VFR CEILINGS BEHIND THIS
FRONT. WINDS WILL BE LIGHT/VARIABLE TO LIGHT SOUTH TODAY AND INTO
TONIGHT.
.OUTLOOK...AREAS OF NON-VFR POSSIBLE WEDNESDAY NIGHT AND THURSDAY.
&&
.MARINE...
IT WILL REMAIN RELATIVELY QUIET ON THE LAKE FOR THE NEXT FEW DAYS.
ONLY FEATURES OF NOTE ARE A WEAK COLD FRONT CROSSING THE LAKE
TONIGHT. THIS AFTERNOON WINDS WILL BE LIGHT/VARIABLE...BECOMING
LIGHT SOUTH AHEAD OF THE FRONT. A SHIFT TO THE WEST CAN BE EXPECTED
AFTER THE FRONT...BUT SPEEDS STILL LIGHT. A SECONDARY TROUGH CROSSES
THE LAKE THURSDAY NIGHT AND HIGH PRESSURE THEN BUILDS ACROSS THE
OHIO VALLEY FOR FRIDAY. ANOTHER WEAK COLD FRONT SLIPS ACROSS THE
LAKE SATURDAY. UNCERTAIN AS TO IF CONDITIONS WILL GET CHOPPY ENOUGH
FOR ANY SMALL CRAFT ADV CONDITIONS. GRADIENT SEEMS FAIRLY WEAK. THE
CHOPPIER CONDITIONS MAY ACTUALLY ARRIVE BRIEFLY SUNDAY AS THE HIGH
BUILDS IN. OBVIOUSLY THERE IS LOW CONFIDENCE YET.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS TULSA OK
1156 PM CDT TUE JUL 30 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
A FEW SHOWERS OR AN ISOLATED THUNDERSTORM WILL REMAIN POSSIBLE
OVERNIGHT AS A WEAK FRONTAL BOUNDARY REMAINS OVER THE AREA...PROBABILITY
REMAINS TOO LOW TO INCLUDE IN TAFS AT THIS TIME. MOIST AIRMASS
WILL LEAD TO MVFR VSBYS IN MANY LOCATIONS IN NE OK AND NW AR...
WITH WIDESPREAD MVFR CEILINGS LIKELY DEVELOPING IN THESE AREAS BY
12Z. CEILINGS LIFT BY AFTERNOON WITH VFR CONDITIONS THEREAFTER.
ISOLATED THUNDERSTORMS POSSIBLE IN TERRAIN OF W AR AND SE OK WED
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 959 PM CDT TUE JUL 30 2013/
DISCUSSION...
MOST OF THE AFTERNOON ACTIVITY HAS DISSIPATED WITH THE LOSS OF
DAYTIME HEATING. HOWEVER...ACTIVITY PERSISTS OVER PORTIONS OF
NORTHWEST ARKANSAS...QUITE SIMILAR TO WHAT THE HRRR MODEL WAS
SUGGESTING THIS AFTERNOON. WITH THE WEAK BOUNDARY STALLED OVER THE
REGION IT IS HARD TO RULE OUT OVERNIGHT ACTIVITY. WILL LEAVE THE
SLIGHT CHANCE POPS IN FOR THE OVERNIGHT. THE 00Z NAM STILL
SUPPORTS THE DEVELOPMENT OF FOG ACROSS NORTHEAST OKLAHOMA AND
NORTHWEST ARKANSAS LATE TONIGHT. OVERALL...WILL NOT MAKE MUCH
CHANGE TO THE GOING FORECAST.
LACY
PREV DISCUSSION... /ISSUED 625 PM CDT TUE JUL 30 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
A FEW SHOWERS OR THUNDERSTORMS WILL LINGER THROUGH 03Z AS WEAK
FRONTAL BOUNDARY PUSHES THROUGH THE AREA OVERNIGHT. MINIMAL
IMPACT AT ANY FORECAST SITE EXPECTED AT THIS TIME. RAINFALL FROM
LAST NIGHT WILL LIKELY LEAD TO MVFR VSBYS AND CEILINGS ACROSS NE
OK AND NW ARKANSAS FROM ABOUT 08-15Z...ESPECIALLY IF SUFFICIENT
CLEARING TAKES PLACE. FRONT SHOULD BE MOSTLY SE OF AREA WED
AFTERNOON.
PREV DISCUSSION... /ISSUED 344 PM CDT TUE JUL 30 2013/
DISCUSSION...
WEAK FRONTAL BOUNDARY CURRENTLY FROM WEST CENTRAL MISSOURI
ON TO CENTRAL OKLAHOMA TO NORTH TEXAS WILL SLIDE SOUTHEAST
TONIGHT TO NEAR INTERSTATE 40 BY WEDNESDAY MORNING. FRONT
CONTINUES SLIDING SOUTH WEDNESDAY TO SOUTH OF RED RIVER.
ALTHOUGH PLENTY OF MOISTURE IS AVAILABLE..UPPER SUPPORT IS
LACKING WHICH TRANSLATES TO CHANCE POPS TONIGHT...MAINLY
BEFORE MIDNIGHT.
UPPER HIGH ANCHORED / CENTERED OVER NEW MEXICO-WEST TEXAS
BRINGS DRY NORTHWEST FLOW WEDNESDAY-THURSDAY. MINOR WAVES
IN THE NORTHWEST FLOW GENERATES LOW CHANCE POPS FRIDAY AND
THE WEEKEND...MAINLY NORTHEAST AREAS.
LOW CHANCE POPS PREVAIL EARLY NEXT WEEK WITH NEAR SEASONAL
(HOT) WEATHER. UNUSUAL...FOR SUMMER...PATTERN FORECAST BY
BOTH ECMWF/GFS NEXT WEEK. SIGNIFICANT HUDSON BAY UPPER LOW
DIVES INTO NORTH CENTRAL STATES...WHILE UPPER RIDGE BUILDS
NORTH INTO BRITISH COLUMBIA YUKON & NORTHWEST TERRITORIES.
GW
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...99
LONG TERM....99
AVIATION...14
AREA FORECAST DISCUSSION...CORRECTION
NWS PENDLETON OR
1244 PM PDT WED JUL 31 2013
CORRECTION APPLIED DUE TO DISSEMINATION ISSUES
.SHORT TERM...UPDATE...AN UPPER LEVEL LOW, WITH EMBEDDED SHORTWAVE
DISTURBANCES, IS OFF THE PACIFIC COASTLINE THIS MORNING ADVECTING
MOISTURE INTO OUR REGION THIS MORNING. RADAR INDICATES THAT SHOWERS
HAVE DEVELOPED OVER THE FOOTHILLS OF THE BLUE MOUNTAINS AND THE JOHN
DAY HIGHLANDS, WHILE THE CASCADES HAVE NO RETURNS SHOWING UP. HAVE
UPDATED THE POP GRIDS THIS MORNING TO INDICATE AN ISOLATED CHANCE OF
SHOWERS FOR MAINLY THE JOHN DAY HIGHLANDS AND THE BLUE MOUNTAINS.
ALSO, AS A RESULT OF CLOUDINESS FROM MORNING ACTIVITY, HAVE TRIMMED
BACK THE MAX TEMPERATURES FOR MOST LOCATIONS.
WATER VAPOR IS SHOWING A SHORTWAVE IMPULSE NEAR THE CALIFORNIA AND
OREGON BORDER, MOVING NORTHEAST TOWARDS OUR CWA. IT IS ANTICIPATED
THAT THIS IMPULSE WILL ARRIVE IN OUR AREA BY THIS AFTERNOON,
PROVIDING A FOCUSING MECHANISM AND LIFT FOR INCREASED THUNDERSTORM
ACTIVITY LATER TODAY. MARGINAL INSTABILITY OF APPROXIMATELY 500 J
PER KG OF ELEVATED CAPE, A STRONG INVERTED V PROFILE IN FORECASTED
SOUNDINGS, AND NEAR 50 KTS OF SHEAR ARE CONDUCIVE FACTORS FOR STRONG
THUNDERSTORMS CAPABLE OF PRODUCING STRONG WINDS AND EVEN SOME SMALL
HAIL. LATEST HRRR RUNS AND HI-RES WRF ENSEMBLE INDICATE THAT THE
STORMS WILL START MAINLY OVER THE CENTRAL AND EASTERN OREGON
HIGHLANDS, THEN PROPAGATE INTO THE LOWER COLUMBIA BASIN LATER THIS
EVENING. BIEDA/SOLOMON
.LONG TERM...PREVIOUS DISCUSSION...FRIDAY NIGHT THROUGH
WEDNESDAY...AN UPPER LOW PRESSURE SYSTEM CENTERED OVER EAST CENTRAL
WASHINGTON FRIDAY NIGHT WILL MOVE OFF TO THE NORTHEAST ON SATURDAY.
IN ITS WAKE THERE WILL BE A REMNANT UPPER TROUGH OVER THE PACIFIC
NORTHWEST AND THE FORECAST AREA. THIS WILL KEEP UNSETTLED AND COOL
CONDITIONS OVER THE FORECAST AREA...ESPECIALLY IN THE NORTHERN
PORTIONS OF THE CWA ON SATURDAY. THIS UNSETTLED WEATHER WILL
DECREASE SUNDAY AND MONDAY AS AN UPPER RIDGE BUILDS OVER THE REGION.
THE UPPER RIDGE WILL BE DEVELOPING IN RESPONSE TO A NEW UPPER LOW
THAT WILL DEVELOP OFF THE NORTHERN CALIFORNIA COAST. THE RESULT WILL
BE MORE DRY CONDITIONS AND A WARMING TREND FOR EARLY NEXT WEEK. THE
LONG RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THIS SCENARIO
THROUGH MONDAY AND TUESDAY THOUGH THERE WILL BE SOME DIFFERENCES TO
EXACTLY WHERE THE UPPER LOW WILL BE CENTERED OFF THE COAST. ON
WEDNESDAY THE MODEL DIFFERENCES BECOME GREATER BUT STILL SHOW A
RIDGE OVER THE CWA WITH AN UPPER LOW OFF THE CALIFORNIA COAST. 88
&&
.AVIATION...18Z TAFS...A LOW PRESSURE SYSTEM WILL BRING AN INCREASE
IN HIGH AND MID LEVEL CLOUDS OVER THE AREA TODAY AND THROUGH
TOMORROW. ISOLATED AND SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL OCCUR ACROSS THE REGION. KDLS...KRDM AND KBDN
WILL BE AFFECTED FIRST THIS AFTERNOON AND THEN SPREAD TO THE REST OF
THE TAF SITES THIS EVENING. MAY SEE BRIEF MVFR CONDITIONS IN RAIN
DIRECTLY UNDER A THUNDERSTORM BUT OTHERWISE VFR CONDITIONS WILL
PREVAIL. CAN NOT PINPOINT EXACTLY WHEN A THUNDERSTORM WILL PASS OVER
A TAF SITE...AND THEREFORE ONLY INDICATED THE POTENTIAL WITH A MID
LEVEL CLOUD LAYER DURING THE AFTERNOON AND EVENING...WHEN THE BEST
THUNDERSTORM POTENTIAL WILL BE. EXPECT WINDS TO REMAIN LESS THAN 15
KTS THROUGH TONIGHT...BUT CAN EXPECT GUSTY WINDS NEAR THUNDERSTORMS.
AREAS OF SMOKE WILL CONTINUE DUE TO AREA WILDFIRES. DMH
&&
.FIRE WEATHER...A LOW PRESSURE SYSTEM WILL BRING THUNDERSTORMS TO
THE FORECAST AREA TODAY. THE FIRST DISTURBANCE IS ROTATING AROUND
THE LOW AND WILL ENTER OUR AREA THIS AFTERNOON. A RED FLAG WARNING
ARE FOR ALL FIRE WEATHER ZONES THROUGH THURSDAY EVENING. WHILE
THUNDERSTORMS WILL START OUT WITH LIGHT PRECIPITATION...EXPECT THEM
TO BECOME WETTER TODAY ALONG THE CASCADES AND THEN TONIGHT INTO
TOMORROW FOR THE REST OF THE REGION. THUNDERSTORMS WILL CONTINUE
TOMORROW AS THE LOW MOVES OVERHEAD. ALL RED FLAG WARNINGS WILL END
TOMORROW NIGHT AND EXPECT THUNDERSTORMS TO DECREASE IN COVERAGE
OVERNIGHT ON TOMORROW NIGHT AND INTO FRIDAY. THUNDERSTORMS ARE
EXPECTED TO HAVE THE POTENTIAL OF PRODUCING STRONG GUSTY WINDS.
SURFACE WINDS WILL ALSO INCREASE ON TOMORROW AS THE LOW MOVES
EASTWARD WITH LOCALLY BREEZY TO WINDY CONDITIONS ESPECIALLY IN THE
COLUMBIA BASIN AND NEAR THE CASCADE GAPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 81 60 83 58 / 20 30 40 30
ALW 84 64 86 62 / 20 30 30 40
PSC 87 64 88 64 / 10 30 30 40
YKM 86 63 86 62 / 20 30 30 30
HRI 85 62 87 63 / 20 30 30 30
ELN 83 61 84 62 / 20 30 40 40
RDM 84 52 76 45 / 30 30 60 20
LGD 80 57 78 54 / 20 30 60 50
GCD 82 57 76 53 / 30 30 60 30
DLS 87 63 80 61 / 30 30 30 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM 8 PM THIS EVENING TO 11 PM PDT THURSDAY
ORZ044-050-508.
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THURSDAY
ORZ049-502-503-505>507.
RED FLAG WARNING UNTIL 11 PM PDT THURSDAY ORZ041-042-509.
WA...RED FLAG WARNING FROM 8 PM THIS EVENING TO 11 PM PDT THURSDAY
WAZ026>029.
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THURSDAY
WAZ030.
RED FLAG WARNING UNTIL 11 PM PDT THURSDAY WAZ024-520-521.
FIRE WEATHER WATCH FROM 8 PM PDT THIS EVENING THROUGH THURSDAY
EVENING WAZ026-027-520.
&&
THREAT INDEX
TODAY : YELLOW
THURSDAY : YELLOW
FRIDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
98/91/84/84
AREA FORECAST DISCUSSION...CORRECTED
NWS PENDLETON OR
931 AM PDT WED JUL 31 2013
CORRECTION IN SHORT TERM DISCUSSION
.SHORT TERM...UPDATE...AN UPPER LEVEL LOW, WITH EMBEDDED SHORTWAVE
DISTURBANCES, IS OFF THE PACIFIC COASTLINE THIS MORNING ADVECTING
MOISTURE INTO OUR REGION THIS MORNING. RADAR INDICATES THAT SHOWERS
HAVE DEVELOPED OVER THE FOOTHILLS OF THE BLUE MOUNTAINS AND THE JOHN
DAY HIGHLANDS, WHILE THE CASCADES HAVE NO RETURNS SHOWING UP. HAVE
UPDATED THE POP GRIDS THIS MORNING TO INDICATE AN ISOLATED CHANCE OF
SHOWERS FOR MAINLY THE JOHN DAY HIGHLANDS AND THE BLUE MOUNTAINS.
ALSO, AS A RESULT OF CLOUDINESS FROM MORNING ACTIVITY, HAVE TRIMMED
BACK THE MAX TEMPERATURES FOR MOST LOCATIONS.
WATER VAPOR IS SHOWING A SHORTWAVE IMPULSE NEAR THE CALIFORNIA AND
OREGON BORDER, MOVING NORTHEAST TOWARDS OUR CWA. IT IS ANTICIPATED
THAT THIS IMPULSE WILL ARRIVE IN OUR AREA BY THIS AFTERNOON,
PROVIDING A FOCUSING MECHANISM AND LIFT FOR INCREASED THUNDERSTORM
ACTIVITY LATER TODAY. MARGINAL INSTABILITY OF APPROXIMATELY 500 J
PER KG OF ELEVATED CAPE, A STRONG INVERTED V PROFILE IN FORECASTED
SOUNDINGS, AND NEAR 50 KTS OF SHEAR ARE CONDUCIVE FACTORS FOR STRONG
THUNDERSTORMS CAPABLE OF PRODUCING STRONG WINDS AND EVEN SOME SMALL
HAIL. LATEST HRRR RUNS AND HI-RES WRF ENSEMBLE INDICATE THAT THE
STORMS WILL START MAINLY OVER THE CENTRAL AND EASTERN OREGON
HIGHLANDS, THEN PROPAGATE INTO THE LOWER COLUMBIA BASIN LATER THIS
EVENING. BIEDA/SOLOMON
.LONG TERM...PREVIOUS DISCUSSION...FRIDAY NIGHT THROUGH
WEDNESDAY...AN UPPER LOW PRESSURE SYSTEM CENTERED OVER EAST CENTRAL
WASHINGTON FRIDAY NIGHT WILL MOVE OFF TO THE NORTHEAST ON SATURDAY.
IN ITS WAKE THERE WILL BE A REMNANT UPPER TROUGH OVER THE PACIFIC
NORTHWEST AND THE FORECAST AREA. THIS WILL KEEP UNSETTLED AND COOL
CONDITIONS OVER THE FORECAST AREA...ESPECIALLY IN THE NORTHERN
PORTIONS OF THE CWA ON SATURDAY. THIS UNSETTLED WEATHER WILL
DECREASE SUNDAY AND MONDAY AS AN UPPER RIDGE BUILDS OVER THE REGION.
THE UPPER RIDGE WILL BE DEVELOPING IN RESPONSE TO A NEW UPPER LOW
THAT WILL DEVELOP OFF THE NORTHERN CALIFORNIA COAST. THE RESULT WILL
BE MORE DRY CONDITIONS AND A WARMING TREND FOR EARLY NEXT WEEK. THE
LONG RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THIS SCENARIO
THROUGH MONDAY AND TUESDAY THOUGH THERE WILL BE SOME DIFFERENCES TO
EXACTLY WHERE THE UPPER LOW WILL BE CENTERED OFF THE COAST. ON
WEDNESDAY THE MODEL DIFFERENCES BECOME GREATER BUT STILL SHOW A
RIDGE OVER THE CWA WITH AN UPPER LOW OFF THE CALIFORNIA COAST. 88
&&
.AVIATION...PREVIOUS DISCUSSION...12Z TAFS...VFR CONDITIONS WILL
PREVAIL. HOWEVER THERE WILL BE AN ABUNDANCE OF HIGH CLOUDS AND SOME
MID LEVEL CLOUDS AS WELL BETWEEN 100-120 AND FROM 200-250. THERE
WILL BE ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS THAT WILL AFFECT KDLS...KRDM...KBDN AND KYKM TODAY.
THE THUNDERSTORM ACTIVITY WILL THEN SPREAD OVER THE REST OF THE AREA
BY THIS EVENING. MOST STORMS THAT DEVELOP WILL BE WEAK BUT THERE
COULD BE SOME TEMPORARY MVFR CONDITIONS DUE TO LOWERING VISIBILITY
IN THE IMMEDIATE VICINITY OF SHOWERS WITH THE STRONGER STORMS.
THUNDERSTORMS WILL BE HIGH BASED SO CIGS WILL STAY WELL ABOVE VFR
MINIMUMS AT ALL TAF SITES. WINDS WILL BE LIGHT AND GENERALLY 5 TO 15
KTS THROUGH TONIGHT. AREAS OF SMOKE WILL CONTINUE IN THE VICINITY OF
WILDFIRES. 88
&&
.FIRE WEATHER...A LOW PRESSURE SYSTEM WILL BRING THUNDERSTORMS TO
THE FORECAST AREA TODAY. THE FIRST DISTURBANCE IS ROTATING AROUND
THE LOW AND WILL ENTER OUR AREA THIS AFTERNOON. A RED FLAG WARNING
ARE FOR ALL FIRE WEATHER ZONES THROUGH THURSDAY EVENING. WHILE
THUNDERSTORMS WILL START OUT WITH LIGHT PRECIPITATION...EXPECT THEM
TO BECOME WETTER TODAY ALONG THE CASCADES AND THEN TONIGHT INTO
TOMORROW FOR THE REST OF THE REGION. THUNDERSTORMS WILL CONTINUE
TOMORROW AS THE LOW MOVES OVERHEAD. ALL RED FLAG WARNINGS WILL END
TOMORROW NIGHT AND EXPECT THUNDERSTORMS TO DECREASE IN COVERAGE
OVERNIGHT ON TOMORROW NIGHT AND INTO FRIDAY. THUNDERSTORMS ARE
EXPECTED TO HAVE THE POTENTIAL OF PRODUCING STRONG GUSTY WINDS.
SURFACE WINDS WILL ALSO INCREASE ON TOMORROW AS THE LOW MOVES
EASTWARD WITH LOCALLY BREEZY TO WINDY CONDITIONS ESPECIALLY IN THE
COLUMBIA BASIN AND NEAR THE CASCADE GAPS.
&&
.PREV DISCUSSION... /ISSUED 700 AM PDT WED JUL 31 2013/
SHORT TERM...TODAY THROUGH FRIDAY AFTERNOON...TROUGH OFFSHORE SETS
UP CONDITIONS FAVORABLE FOR THUNDERSTORMS FOR THE NEXT THREE DAYS.
STRONG VERTICAL WIND SHEAR TODAY MAY SUPPORT A FEW STRONG OR
MARGINALLY SEVERE STORMS BUT INSTABILITY IS ONLY MARGINAL TODAY. AS
SUCH A FEW STORMS TODAY AND THIS EVENING MAY BE CAPABLE OF PRODUCING
MARGINALLY SEVERE HAIL TO ONE INCH IN DIAMETER AND GUSTY WINDS.
THUNDERSTORMS WILL BEGIN OVER THE MOUNTAINS IN CENTRAL OREGON AND
THE SOUTHERN BLUE MOUNTAINS BY MID AFTERNOON TODAY. SOME STORMS MAY
MOVE NORTH INTO THE LOWER COLUMBIA BASIN AS WELL AS NORTH CENTRAL
OREGON IN THE EVENING.
A MID/UPPER LEVEL SHORT WAVE SWINGS EAST OF THE OREGON CASCADES
OVERNIGHT THUS SOME STRONG DYNAMIC LIFT, WHICH WILL TRIGGER ISOLATED
TO SCATTERED NOCTURNAL THUNDERSTORMS IN THE BLUE MOUNTAINS TOWARD
DAYBREAK THURSDAY MORNING WITH STORMS BEING TRIGGERED BY DYNAMIC
LIFT FOR THE DURATION OF THURSDAY. STORMS ON THURSDAY ARE NOT
EXPECTED TO BE SEVERE. ALTHOUGH THE ATMOSPHERE WILL BE MUCH MORE
UNSTABLE DURING THE DAYTIME ON THURSDAY, ONLY WEAK VERTICAL WIND
SHEAR IS EXPECTED SO THE THUNDERSTORMS THURSDAY SHOULD BE WEAKER
THAN STORMS TODAY.
THE FOCUS FOR THUNDERSTORMS SHIFTS TO NE OREGON AND SE WASHINGTON ON
FRIDAY AS THE UPPER LEVEL TROUGH SWINGS EAST OF THE CASCADES. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 86 60 86 58 / 20 30 40 30
ALW 90 63 88 62 / 20 30 30 40
PSC 91 63 90 63 / 10 30 30 40
YKM 86 63 89 62 / 20 30 30 40
HRI 89 61 89 62 / 20 30 30 30
ELN 87 60 87 62 / 20 30 40 50
RDM 83 52 79 45 / 30 30 60 20
LGD 89 55 82 53 / 20 30 50 50
GCD 89 56 82 53 / 30 30 60 30
DLS 88 61 82 60 / 30 30 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM 8 PM THIS EVENING TO 11 PM PDT THURSDAY
ORZ044-050-508.
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THURSDAY
ORZ049-502-503-505>507.
RED FLAG WARNING UNTIL 11 PM PDT THURSDAY ORZ041-042-509.
WA...RED FLAG WARNING FROM 8 PM THIS EVENING TO 11 PM PDT THURSDAY
WAZ026>029.
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THURSDAY
WAZ030.
RED FLAG WARNING UNTIL 11 PM PDT THURSDAY WAZ024-520-521.
FIRE WEATHER WATCH FROM 8 PM PDT THIS EVENING THROUGH THURSDAY
EVENING WAZ026-027-520.
&&
THREAT INDEX
TODAY : YELLOW
THURSDAY : YELLOW
FRIDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
98/91/84/84
AREA FORECAST DISCUSSION
NWS MEDFORD OR
930 AM PDT WED JUL 31 2013
.SHORT TERM...A SHORTWAVE HAS MOVED OVER THE AREA THIS MORNING.
HOWEVER DESPITE ELEVATED INSTABILITY AND A JET ALOFT WE HAVE NOT
SEEN THUNDERSTORMS DEVELOP THIS MORNING WEST OF THE CASCADES. THE
LATEST RAP FORECAST SHOWS SOME PRECIPITATION AND POSSIBLE
THUNDERSTORM DEVELOPMENT IN PORTIONS OF DOUGLAS COUNTY AS THIS
SHORTWAVE CONTINUES TO MOVE NORTH THIS MORNING. SO WILL LEAVE
THUNDERSTORMS IN THE WESTERN VALLEYS FOR NOW BUT MAY UPDATE LATE
THIS MORNING IF NOTHING DEVELOPS TO REMOVE THEM FROM JOSEPHINE
COUNTY AND WESTERN DOUGLAS COUNTY. FURTHER EAST THIS MORNING SOME
WEAK SHOWERS HAVE DEVELOPED OVER MODOC AND LAKE COUNTY. HAVE ADDED
THESE TO THE FORECAST. THESE ARE VERY HIGH BASED AND EXPECT LITTLE
IF ANY PRECIPITATION TO REACH THE GROUND. THE SHORTWAVE ASSOCIATED
WITH THESE SHOWERS IS EXPECTED TO TRACK NORTH-NORTHEAST TODAY AND
OUT OF THE AREA IN THE AFTERNOON. WILL MONITOR THIS ISSUE AS WELL.
THEN IN THE AFTERNOON AND EVENING TODAY, THE FORECAST IS ON TRACK
FOR ISOLATED TO SCATTERED THUNDERSTORMS TO DEVELOP FROM THE
SOUTHERN OREGON CASCADES EAST INTO KLAMATH AND NORTHERN LAKE
COUNTY. ALSO SOME ISOLATED THUNDERSTORMS MAY DEVELOP OVER THE
SISKIYOUS AND MOVE INTO THE ROGUE VALLEY. ADDITIONALLY THE WESTERN
FOOTHILLS OF THE CASCADES IN JACKSON AND DOUGLAS COUNTIES MAY SEE
THUNDERSTORMS AS WELL. HAVE ADDED ISOLATED THUNDERSTORMS INTO THE
AFTERNOON AND EVENING FORECAST TODAY FOR AREAS FURTHER SOUTH WHERE
THE RAP, WRF, NAM AND GFS ARE SHOWING A POTENTIAL FOR CONVECTION -
THIS INCLUDES CENTRAL AND EASTERN SISKIYOU COUNTY AND FAR
NORTHWEST MODOC COUNTY.
SMOKE REMAINS A CONCERN OVER SOUTHWEST PORTIONS OF THE AREA AND
ESPECIALLY IN THE WESTERN SOUTHERN OREGON VALLEYS. THE LATEST
SMOKE FORECAST FOR SURFACE SMOKE INDICATES THAT CONDITIONS MAY
IMPROVE ON THURSDAY AROUND LATE MORNING BUT DEGRADE AGAIN IN THE
LATE AFTERNOON AND EVENING.
&&
.AVIATION...WILDFIRES BURNING IN DOUGLAS AND JOSEPHINE COUNTIES
WILL CONTINUE TO PRODUCE PLENTY OF SMOKE ACROSS SOUTHWEST OREGON
AND NORTHERN CALIFORNIA. THIS SMOKE WILL CAUSE MOUNTAIN
OBSCURATIONS AND REDUCE VISIBILITIES AT LOWER ELEVATIONS...EVEN
DOWN TO IFR AT TIMES.
THERE IS A SLIGHT CHANCE OF DRY THUNDERSTORMS THIS MORNING
ACROSS THE INLAND WEST SIDE VALLEYS OF OREGON AND AREAS NEAR THE
CASCADES AS WINDS AND MOISTURE INCREASE ALOFT. BY THIS AFTERNOON
AND EVENING...THUNDERSTORMS WILL ALSO BE POSSIBLE IN AND EAST OF
THE CASCADES IN OREGON, ESPECIALLY AROUND CRATER LAKE AND THE EAST
SIDE NORTH OF KLMT.
ELSEWHERE...AWAY FROM THE FIRES...EXPECT VFR, BUT MARINE STRATUS
WILL BRING MVFR/IFR CIGS AND PATCHY FOG TO COASTAL AREAS, MAINLY
NORTH OF CAPE BLANCO AND ALSO NEAR BROOKINGS. SOME OF THESE CIGS
WILL SPREAD INLAND TO THE UMPQUA BASIN. STRATUS WILL ERODE BACK TO
THE COASTLINE BY LATE MORNING.
&&
.PREV DISCUSSION... /ISSUED 100 AM PDT WED JUL 31 2013/
DISCUSSION...31/00Z NAM/GFS IN.
THE MAIN STORY THIS MORNING IS THE EXTREMELY SMOKY CONDITIONS OVER
PORTIONS OF SOUTHWEST OREGON AND NORTHERN CALIFORNIA. THERE IS
ALSO THE THREAT OF THUNDERSTORM ACTIVITY NOW THROUGH THURSDAY.
OTHER THAN THAT THERE IS MARINE STRATUS ALONG PORTIONS OF THE
COAST AND LOTS OF MIDDLE AND HIGH LEVEL CLOUD COVERAGE ASSOCIATED
WITH AN INCOMING SHORT WAVE.
A LONG WAVE UPPER TROUGH IS NOW OFFSHORE NEAR 130W. SHORT WAVES
EJECTING FROM THIS TROUGH WILL ENHANCE UPPER LEVEL INSTABILITY AND
THUS INCREASE THE CHANCES OF CONVECTION. THE FIRST IN THE SERIES
IS NOW MOVING THROUGH THE AREA. A SECOND WEAKER WAVE WILL MOVE
THROUGH WEDNESDAY AFTERNOON AND EVENING. SEVERAL MORE WEAKER WAVES
WILL FOLLOW WEDNESDAY NIGHT INTO THURSDAY AS THE LONG WAVE TROUGH
APPROACHES THE COAST. THE TROUGH WILL MOVE ONSHORE THURSDAY NIGHT
BUT WILL REMAIN OVER THE PACIFIC NORTHWEST AS SHORT WAVES MOVE
DOWN THE BACKSIDE OF THE TROUGH AND SLOW ITS PROGRESS.
THE EVENING SHIFT DID AN EXCELLENT ANALYSIS OF THE CONVECTION
POTENTIAL THROUGH WEDNESDAY. IT FOLLOWS WITH SOME ADDITIONAL
INFORMATION ADDED FROM THE 31/00Z RUNS.
31/00Z GUIDANCE SHOWS INCREASING MID LEVEL INSTABILITY AS A SHORT
WAVE ARRIVES AND MOVES THROUGH WHICH MEANS THE POTENTIAL FOR
NOCTURNAL THUNDERSTORMS TUESDAY NIGHT. THE 31/00Z KMFR SOUNDING
SHOWS INCREASING MOISTURE ALOFT BUT IS ALSO OF THE INVERTED-V TYPE
BELOW 700 MB...WHICH MEANS VERY DRY AIR REMAINS IN THE LOW
LEVELS. THUS...ANY THUNDERSTORMS THAT DO DEVELOP ARE LIKELY TO BE
DRY AND MAY RESULT IN MORE FIRE STARTS. THESE STORMS WOULD ALSO BE
CAPABLE OF STRONG GUSTY DOWNDRAFT WINDS (DCAPES > 500 J/KG) WHICH
WOULD BE VERY HAZARDOUS TO PERSONNEL FIGHTING EXISTING FIRES.
CONDITIONS WILL CONTINUE TO DESTABILIZE LATER THIS MORNING INTO
THIS AFTERNOON. THE LATEST DLP (DRY LIGHTNING POTENTIAL) GUIDANCE
SHOWS THE GREATEST THREAT FOR DRY STORMS ON THE WEST SIDE FROM
12Z-18Z WEDNESDAY WITH CONDITIONS BECOMING VERY UNSTABLE IN THE
AFTERNOON (LI`S -4 TO -6, MID LEVEL LAPSE RATES 8.5C/KM, AND CAPES
> 500 J/KG). THE MAIN THREAT WILL BE OVER THE WESTERN INTERIOR
VALLEYS AND THE CASCADES. THE STORMS WILL TEND TO BECOME WETTER
WEDNESDAY AFTERNOON OVER THE WEST SIDE...BUT THEY`LL BE MOVING
RIGHT ALONG...SO PRECIPITATION TOTALS WILL REMAIN LOW.
THE MAIN THREAT AREA WILL SHIFT TO THE CASCADES AND EAST SIDE
THURSDAY AS A MARINE PUSH BRINGS IN COOLER AIR AND MORE STABLE
CONDITIONS TO THE WEST SIDE. MODEL LIFTED INDICES ARE NOT AS
IMPRESSIVE THEN AS THEY ARE FOR WEDNESDAY. EXPECT CONTINUED
THUNDERSTORM ACTIVITY FROM THE CASCADES EAST BUT COVERAGE AND
INTENSITY WILL BE LESS. FRIDAY WILL BE MORE STABLE. THE MAIN
THREAT AREA BY THAT TIME WILL BE EAST OF THE CASCADES. IF THE
31/00Z GFS VERIFIES THERE WILL BE NO THUNDERSTORMS FRIDAY OR
SATURDAY. THE NAM IS SLIGHTLY MORE UNSTABLE AND MAY SUPPORT
ISOLATED COVERAGE OVER LAKE COUNTY FRIDAY.
WEAK LOW PRESSURE WILL LINGER OVER THE AREA THROUGH THE WEEKEND
WITH A WARMING TREND. UNSTABLE CONDITIONS MAY REDEVELOP SUNDAY AND
THE CURRENT FORECAST INCLUDES A SLIGHT CHANCE OF AFTERNOON/EVENING
THUNDERSTORMS OVER THE HIGHER TERRAIN. THE TROUGH IS CURRENTLY
PROGGED TO SHEAR EARLY NEXT WEEK...LEAVING A CUTOFF LOW OFF THE
CALIFORNIA COAST. AT THAT POINT THE FORECAST WILL BE DEPENDENT ON
THE LOCATION OF THE CUTOFF...WHICH IS A REAL DICEY FORECAST THIS
FAR OUT. THE LOW WILL LIKELY REMAIN WHEREVER IT SETS UP UNTIL AT
LEAST THE MIDDLE OF NEXT WEEK.
AVIATION...WILDFIRES BURNING IN DOUGLAS AND JOSEPHINE COUNTIES
WILL CONTINUE TO PRODUCE PLENTY OF SMOKE ACROSS SOUTHWEST OREGON
AND NORTHERN CALIFORNIA. THIS SMOKE WILL CAUSE MOUNTAIN
OBSCURATIONS AND REDUCE VISIBILITIES AT LOWER ELEVATIONS...EVEN
DOWN TO IFR AT TIMES.
ISOLATED DRY THUNDERSTORMS MAY DEVELOP LATER THIS MORNING ACROSS
THE INLAND WEST SIDE VALLEYS OF OREGON AND AREAS NEAR THE CASCADES
AS WINDS AND MOISTURE INCREASE ALOFT. BY THIS AFTERNOON AND
EVENING...THUNDERSTORMS WILL ALSO BE POSSIBLE IN AND EAST OF THE
CASCADES IN OREGON...ESPECIALLY AROUND CRATER LAKE AND THE EAST
SIDE NORTH OF KLMT.
ELSEWHERE...AWAY FROM THE FIRES...EXPECT VFR...BUT MARINE STRATUS
WILL BRING MVFR/IFR CIGS AND PATCHY FOG TO COASTAL AREAS...MAINLY
NORTH OF CAPE BLANCO AND ALSO NEAR BROOKINGS. SOME OF THESE CIGS
WILL SPREAD INLAND TO THE UMPQUA BASIN. STRATUS WILL ERODE BACK TO
THE COASTLINE BY LATE MORNING. -WRIGHT
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR ORZ021-024.
RED FLAG WARNING UNTIL 8 PM PDT THURSDAY FOR ORZ023-026.
RED FLAG WARNING UNTIL 2 PM PDT THIS AFTERNOON FOR ORZ022.
RED FLAG WARNING UNTIL 11 PM PDT THURSDAY FOR
ORZ025-027-030-031.
RED FLAG WARNING UNTIL 11 PM PDT THURSDAY FOR ORZ028-029.
CA...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR CAZ080.
PACIFIC COASTAL WATERS...NONE.
$$
CC
AREA FORECAST DISCUSSION
NWS PENDLETON OR
921 AM PDT WED JUL 31 2013
.SHORT TERM...UPDATE...AN UPPER LEVEL LOW, WITH EMBEDDED SHORTWAVE
DISTURBANCES, IS OFF THE PACIFIC COASTLINE THIS MORNING ADVECTING
MOISTURE INTO OUR REGION THIS MORNING. RADAR INDICATES THAT SHOWERS
HAVE DEVELOPED OVER THE FOOTHILLS OF THE BLUE MOUNTAINS AND THE JOHN
DAY HIGHLANDS, WHILE THE CASCADES HAVE NO RETURNS SHOWING UP. HAVE
UPDATED THE POP GRIDS THIS MORNING TO INDICATE AN ISOLATED CHANCE OF
SHOWERS FOR MAINLY THE JOHN DAY HIGHLANDS AND THE BLUE MOUNTAINS.
ALSO, AS A RESULT OF CLOUDINESS FROM MORNING ACTIVITY, HAVE TRIMMED
BACK THE MAX TEMPERATURES FOR MOST LOCATIONS.
WATER VAPOR IS SHOWING A SHORTWAVE IMPULSE NEAR THE CALIFORNIA AND
OREGON BORDER, MOVING NORTHEAST TOWARDS OUR CWA. IT IS ANTICIPATED
THAT THIS IMPULSE WILL ARRIVE IN OUR AREA BY THIS AFTERNOON,
PROVIDING A FOCUSING MECHANISM AND LIFT FOR INCREASED THUNDERSTORM
ACTIVITY LATER TODAY. MARGINAL INSTABILITY OF APPROXIMATELY 500 J
PER KG OF ELEVATED CAPE, A STRONG INVERTED V PROFILE IN FORECASTED
SOUNDINGS, AND NEAR 50 KTS ARE CONDUCIVE FACTORS FOR STRONG
THUNDERSTORMS CAPABLE OF PRODUCING STRONG WINDS AND EVEN SOME SMALL
HAIL. LATEST HRRR RUNS AND HI-RES WRF ENSEMBLE INDICATE THAT THE
STORMS WILL START MAINLY OVER THE CENTRAL AND EASTERN OREGON
HIGHLANDS, THEN PROPAGATE INTO THE LOWER COLUMBIA BASIN LATER THIS
EVENING. BIEDA/SOLOMON
.LONG TERM...PREVIOUS DISCUSSION...FRIDAY NIGHT THROUGH
WEDNESDAY...AN UPPER LOW PRESSURE SYSTEM CENTERED OVER EAST CENTRAL
WASHINGTON FRIDAY NIGHT WILL MOVE OFF TO THE NORTHEAST ON SATURDAY.
IN ITS WAKE THERE WILL BE A REMNANT UPPER TROUGH OVER THE PACIFIC
NORTHWEST AND THE FORECAST AREA. THIS WILL KEEP UNSETTLED AND COOL
CONDITIONS OVER THE FORECAST AREA...ESPECIALLY IN THE NORTHERN
PORTIONS OF THE CWA ON SATURDAY. THIS UNSETTLED WEATHER WILL
DECREASE SUNDAY AND MONDAY AS AN UPPER RIDGE BUILDS OVER THE REGION.
THE UPPER RIDGE WILL BE DEVELOPING IN RESPONSE TO A NEW UPPER LOW
THAT WILL DEVELOP OFF THE NORTHERN CALIFORNIA COAST. THE RESULT WILL
BE MORE DRY CONDITIONS AND A WARMING TREND FOR EARLY NEXT WEEK. THE
LONG RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THIS SCENARIO
THROUGH MONDAY AND TUESDAY THOUGH THERE WILL BE SOME DIFFERENCES TO
EXACTLY WHERE THE UPPER LOW WILL BE CENTERED OFF THE COAST. ON
WEDNESDAY THE MODEL DIFFERENCES BECOME GREATER BUT STILL SHOW A
RIDGE OVER THE CWA WITH AN UPPER LOW OFF THE CALIFORNIA COAST. 88
&&
.AVIATION...PREVIOUS DISCUSSION...12Z TAFS...VFR CONDITIONS WILL
PREVAIL. HOWEVER THERE WILL BE AN ABUNDANCE OF HIGH CLOUDS AND SOME
MID LEVEL CLOUDS AS WELL BETWEEN 100-120 AND FROM 200-250. THERE
WILL BE ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS THAT WILL AFFECT KDLS...KRDM...KBDN AND KYKM TODAY.
THE THUNDERSTORM ACTIVITY WILL THEN SPREAD OVER THE REST OF THE AREA
BY THIS EVENING. MOST STORMS THAT DEVELOP WILL BE WEAK BUT THERE
COULD BE SOME TEMPORARY MVFR CONDITIONS DUE TO LOWERING VISIBILITY
IN THE IMMEDIATE VICINITY OF SHOWERS WITH THE STRONGER STORMS.
THUNDERSTORMS WILL BE HIGH BASED SO CIGS WILL STAY WELL ABOVE VFR
MINIMUMS AT ALL TAF SITES. WINDS WILL BE LIGHT AND GENERALLY 5 TO 15
KTS THROUGH TONIGHT. AREAS OF SMOKE WILL CONTINUE IN THE VICINITY OF
WILDFIRES. 88
&&
.FIRE WEATHER...A LOW PRESSURE SYSTEM WILL BRING THUNDERSTORMS TO
THE FORECAST AREA TODAY. THE FIRST DISTURBANCE IS ROTATING AROUND
THE LOW AND WILL ENTER OUR AREA THIS AFTERNOON. A RED FLAG WARNING
ARE FOR ALL FIRE WEATHER ZONES THROUGH THURSDAY EVENING. WHILE
THUNDERSTORMS WILL START OUT WITH LIGHT PRECIPITATION...EXPECT THEM
TO BECOME WETTER TODAY ALONG THE CASCADES AND THEN TONIGHT INTO
TOMORROW FOR THE REST OF THE REGION. THUNDERSTORMS WILL CONTINUE
TOMORROW AS THE LOW MOVES OVERHEAD. ALL RED FLAG WARNINGS WILL END
TOMORROW NIGHT AND EXPECT THUNDERSTORMS TO DECREASE IN COVERAGE
OVERNIGHT ON TOMORROW NIGHT AND INTO FRIDAY. THUNDERSTORMS ARE
EXPECTED TO HAVE THE POTENTIAL OF PRODUCING STRONG GUSTY WINDS.
SURFACE WINDS WILL ALSO INCREASE ON TOMORROW AS THE LOW MOVES
EASTWARD WITH LOCALLY BREEZY TO WINDY CONDITIONS ESPECIALLY IN THE
COLUMBIA BASIN AND NEAR THE CASCADE GAPS.
&&
.PREV DISCUSSION... /ISSUED 700 AM PDT WED JUL 31 2013/
SHORT TERM...TODAY THROUGH FRIDAY AFTERNOON...TROUGH OFFSHORE SETS
UP CONDITIONS FAVORABLE FOR THUNDERSTORMS FOR THE NEXT THREE DAYS.
STRONG VERTICAL WIND SHEAR TODAY MAY SUPPORT A FEW STRONG OR
MARGINALLY SEVERE STORMS BUT INSTABILITY IS ONLY MARGINAL TODAY. AS
SUCH A FEW STORMS TODAY AND THIS EVENING MAY BE CAPABLE OF PRODUCING
MARGINALLY SEVERE HAIL TO ONE INCH IN DIAMETER AND GUSTY WINDS.
THUNDERSTORMS WILL BEGIN OVER THE MOUNTAINS IN CENTRAL OREGON AND
THE SOUTHERN BLUE MOUNTAINS BY MID AFTERNOON TODAY. SOME STORMS MAY
MOVE NORTH INTO THE LOWER COLUMBIA BASIN AS WELL AS NORTH CENTRAL
OREGON IN THE EVENING.
A MID/UPPER LEVEL SHORT WAVE SWINGS EAST OF THE OREGON CASCADES
OVERNIGHT THUS SOME STRONG DYNAMIC LIFT, WHICH WILL TRIGGER ISOLATED
TO SCATTERED NOCTURNAL THUNDERSTORMS IN THE BLUE MOUNTAINS TOWARD
DAYBREAK THURSDAY MORNING WITH STORMS BEING TRIGGERED BY DYNAMIC
LIFT FOR THE DURATION OF THURSDAY. STORMS ON THURSDAY ARE NOT
EXPECTED TO BE SEVERE. ALTHOUGH THE ATMOSPHERE WILL BE MUCH MORE
UNSTABLE DURING THE DAYTIME ON THURSDAY, ONLY WEAK VERTICAL WIND
SHEAR IS EXPECTED SO THE THUNDERSTORMS THURSDAY SHOULD BE WEAKER
THAN STORMS TODAY.
THE FOCUS FOR THUNDERSTORMS SHIFTS TO NE OREGON AND SE WASHINGTON ON
FRIDAY AS THE UPPER LEVEL TROUGH SWINGS EAST OF THE CASCADES. POLAN
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 86 60 86 58 / 20 30 40 30
ALW 90 63 88 62 / 20 30 30 40
PSC 91 63 90 63 / 10 30 30 40
YKM 86 63 89 62 / 20 30 30 40
HRI 89 61 89 62 / 20 30 30 30
ELN 87 60 87 62 / 20 30 40 50
RDM 83 52 79 45 / 30 30 60 20
LGD 89 55 82 53 / 20 30 50 50
GCD 89 56 82 53 / 30 30 60 30
DLS 88 61 82 60 / 30 30 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM 8 PM THIS EVENING TO 11 PM PDT THURSDAY
ORZ044-050-508.
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THURSDAY
ORZ049-502-503-505>507.
RED FLAG WARNING UNTIL 11 PM PDT THURSDAY ORZ041-042-509.
WA...RED FLAG WARNING FROM 8 PM THIS EVENING TO 11 PM PDT THURSDAY
WAZ026>029.
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THURSDAY
WAZ030.
RED FLAG WARNING UNTIL 11 PM PDT THURSDAY WAZ024-520-521.
FIRE WEATHER WATCH FROM 8 PM PDT THIS EVENING THROUGH THURSDAY
EVENING WAZ026-027-520.
&&
THREAT INDEX
TODAY : YELLOW
THURSDAY : YELLOW
FRIDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
98/91/84/84
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1103 PM CDT TUE JUL 30 2013
.UPDATE...
ISSUED AT 1000 PM CDT TUE JUL 30 2013
MAINLY DRY RIGHT NOW ACROSS THE CWA...WITH JUST MAYBE SOME SPRINKLES
NORTH OF INTERSTATE 90. CONVECTION EVOLUTION OVERNIGHT REMAINS LOW
CONFIDENCE. HOWEVER IT APPEARS LIKE WE WILL SEE A LULL OVER THE NEXT
FEW HOURS. LATER TONIGHT...SEE PRETTY STRONG THETAE ADVECTION AROUND
800 TO 850 MB...FOCUSED ACROSS THE SOUTHWEST HALF OF THE CWA.
MEANWHILE...BEST UPPER LEVEL FORCING WILL MOVE TO OUR NORTH. LATEST
NAM AND HRRR IN PRETTY GOOD AGREEMENT THAT STORMS CURRENTLY OVER
NORTHERN WYOMING AND SOUTHERN MONTANA WILL MAINTAIN THEMSELVES AS
THEY PUSH EAST TOWARDS OUR AREA. MOST MODEL SOLUTIONS HINT AT AREAS
ALONG AND SOUTH OF INTERSTATE 90 BEING FAVORED BY THIS LATE NIGHT
CONVECTION. THIS WOULD MAKE SENSE GIVEN WHERE THETAE ADVECTION SEEMS
TO WANT TO FOCUS. HOWEVER WITH THE WAVE PASSING TO OUR NORTH...AND
THE RAP AND HRRR BOTH SHOWING ACTIVITY NORTH OF INTERSTATE 90...WILL
JUST KEEP AN EQUAL THREAT OF 40 TO 50 POPS ACROSS THE ENTIRE
CWA...WITH PROGRESSION FROM WEST TO EAST FROM ABOUT 09Z TO 15Z. GIVEN
THE ELEVATED NATURE OF CONVECTION AND LOW INSTABILITY...NOT THINKING
WE SEE ANY SEVERE WEATHER WITH THIS ACTIVITY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 303 PM CDT TUE JUL 30 2013
UPPER DYNAMICS AND RESULTING LIFT SHOULD BE BEST FOR STORMS IN THE
NORTHERN PART OF OUR FORECAST AREA TONIGHT...BUT SOME SIGNIFICANT
CELLS POSSIBLE SOUTHWEST ALSO WHERE BETTER HEATING AND INSTABILITY
WILL COMBINE WITH DECENT MOISTURE. WIND FIELDS ARE NOTHING TO BRAG
ABOUT AT ANY LEVEL AND WILL KEEP TOP POPS NORTH BARELY INTO THE
LIKELY RANGE. WILL BRING THE THREAT INTO THE FAR WEST AT THE START
OF THE EVENING AND MOVE IT SLOWLY EAST. SPC MENTION OF CELLS AND
CLUSTERS SEEMS RIGHT AS IT DOES NOT LOOK LIKE AN MCS ENVIRONMENT.
SEVERE RISK SLIGHT FOR EARLY THIS EVENING OUT WEST ALSO SEEMS RIGHT.
THE SLOW MOVEMENT OF THE THREAT WILL BRING IT INTO THE EXTREME
SOUTHEAST PART OF OUR AREA...SUCH AS TO SLB IN NORTHWEST IA...ABOUT
7 AM CDT/12Z WEDNESDAY. BY THAT TIME THE THREAT WILL BEGIN TO
DECREASE FROM THE NORTHWEST. EXCEPT FOR THE 12Z NAM RUN WHICH
SUGGESTS HANGING ONTO THE THREAT SOUTHEAST WEDNESDAY EVENING...
MODELS HAVE ACTIVITY OUT OF THE DAY BY THE END OF THE WEDNESDAY
DAYTIME PERIOD. SKIES SHOULD GO MOSTLY CLEAR FROM THE NORTHWEST
WEDNESDAY BEHIND THE DECREASE IN SHOWERS AND STORMS.
ASIDE FROM THE SHOWERS AND STORMS...SOLID LOW CLOUDS MAY STAY
ANCHORED SOUTHEAST/FAR EAST INTO MUCH OF TONIGHT...THOUGH THERE ARE
A FEW HOURS OF DAYTIME HEATING LEFT TO BREAK THE CLOUDS UP A LITTLE
MORE. LOW TEMPERATURE SHOULD BE MOSTLY IN THE LOWER 60S TONIGHT.
UPPER 70S NORTHEAST TO LOWER 80S SOUTHWEST LOOK GOOD FOR HIGHS
WEDNESDAY BASED ON LINGERING CLOUD COVER WITH THE CONTINUING MORNING
PRECIPITATION.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 303 PM CDT TUE JUL 30 2013
NOT MUCH ACTIVITY WEDNESDAY NIGHT AS CONVECTIVE THREAT SHIFTS SOUTH
AND EAST AND HIGH PRESSURE BUILDS IN. WITH CLEAR SKIES AND LIGHT
WINDS WILL GO A LITTLE COOLER THAN GUIDANCE...AIMING FOR THE MID TO
UPPER 50S IN MOST SPOTS. NOT OUT OF THE QUESTION FOR A FEW LOW SPOTS
TO TOUCH 50 DEGREES.
A FAIRLY STRONG LITTLE JET MAX SCOOTS THROUGH MINNESOTA ON THURSDAY
AND THURSDAY NIGHT WHICH WILL DRIVE A BOUNDARY SOUTH THURSDAY NIGHT.
TO THE SOUTH AND SOUTHWEST OF THIS JET MAX THE LOW AND MID LEVEL
WIND FIELD ENHANCES WITH A MODERATELY STRONG LOW LEVEL JET AROUND
850MB FOCUSING AROUND THE MISSOURI RIVER FROM ABOUT 0Z FRIDAY
THROUGH 6Z FRIDAY. DEEPER LAYER SHEAR INCREASES A BIT DURING THIS
TIME AS WELL AS THE 700-500MB WINDS TURN MORE NORTHWEST AND
STRENGTHEN A BIT. A SOMEWHAT STABLE AIR MASS WILL LIKELY BE IN PLACE
INITIALLY BUT WITH THE INCREASING LOW LEVEL JET BETTER ELEVATED
INSTABILITY LIKELY TO FEED INTO THE FAR SOUTHERN CWA FROM 0Z TO 6Z
FRIDAY. WHILE THE SEVERE THREAT WILL BE HIGHER TO THE SOUTH AND
SOUTHWEST OF THE CWA THERE WILL STILL BE A THREAT IN THE FAR
SOUTHERN CWA. GOING FORECAST FOR THIS LOOKS PRETTY GOOD AND WILL NOT
STRAY TOO FAR FROM IT. THE FAR NORTHERN CWA MAY HAVE TROUBLE GETTING
ANY ACTIVITY THURSDAY AND THURSDAY NIGHT.
FRIDAY WILL SEE MORE STABLE AIR SETTLE IN FROM THE NORTH AND SHOULD
PROVIDE THE AREA WITH A QUIET AND FAIRLY PLEASANT DAY. HIGHS MAINLY
MID 70S TO LOWER 80S WITH FAIRLY AVERAGE SUMMER TIME HUMIDITY
VALUES.
FOR SATURDAY THROUGH TUESDAY...OVERALL PATTERN CONTINUES TO BE
SOMEWHAT ANOMALOUS FOR THIS TIME OF YEAR WITH A WEAK RIDGE OF HIGH
PRESSURE OVER THE WESTERN HIGH PLAINS AND MODERATE WEST TO NORTHWEST
FLOW ALOFT. THIS KEEPS THE LOWER AND MID LEVEL TEMPERATURES A LITTLE
COOLER THAN NORMAL AS WELL SO SUSPECT THAT TEMPERATURES WILL REMAIN
BELOW NORMAL THROUGH THE PERIOD. IN FACT LOOKING AT THE ECMWF
ENSEMBLE OUTPUT OF 850MB TEMPERATURES THERE IS A REALLY STRONG
SIGNAL TO REMAIN BELOW NORMAL AS 90 TO 95 PERCENT OF THE MEMBERS ARE
COOLER THAN THE THE SEASONAL NORMAL THROUGH ABOUT AUGUST 12. IT DOES
APPEAR THAT THIS PATTERN WILL BE A BIT MORE SUPPORTIVE OF RAIN
CHANCES SO WILL NEED TO INCLUDE SOME MENTION DURING THIS TIME. WILL
AIM FOR THE BEST CHANCE FOR THIS SUNDAY INTO MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1103 PM CDT TUE JUL 30 2013
QUIEST START TO THE PERIOD...WITH SCATTERED SHRA/TSRA EXPECTED TO
MOVE BACK INTO WESTERN AREAS AFTER 08Z-09Z. THIS ACTIVITY WILL MOVE
ACROSS THE FORECAST AREA THROUGH THE MORNING...FOLLOWED BY GRADUAL
CLEARING THROUGH THE AFTERNOON. WITH RELATIVELY WEAK INSTABILITY
THROUGH THE EARLY MORNING...ALONG WITH LOW CONFIDENCE IN TIMING AND
COVERAGE...HAVE LEFT MENTION OF THUNDER OUT OF KHON/KFSD TAFS...BUT
DO HAVE TEMPO GROUP FOR SHRA FOR MOST LIKELY TIME. ASIDE FROM THE
CONVECTIVE POTENTIAL...VFR CONDITIONS WILL BE DOMINANT. HOWEVER MVFR
TO LOCALLY IFR VISIBILITIES COULD EXPAND BACK INTO PARTS OF NORTHWEST
IOWA DURING THE EARLY MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...
LONG TERM...08
AVIATION...JH
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
346 PM CDT WED JUL 31 2013
.SHORT TERM...
A WEAK COLD FRONT WAS SITUATED ROUGHLY ALONG THE I-20 CORRIDOR THIS
AFTERNOON. THIS FRONT IS EXPECTED TO DROP A BIT FARTHER SOUTH INTO
NORTHERN PORTIONS OF THE CONCHO VALLEY AND HEARTLAND BEFORE STALLING
OUT TONIGHT. THE FRONT WILL BECOME MORE DIFFUSE ON THURSDAY AND
SHOULD WASH OUT ACROSS THE AREA BY AFTERNOON. AS OF 3 PM...ISOLATED
CONVECTION HAS FORMED JUST AHEAD OF THE FRONT OVER SOUTHERN PORTIONS
OF THE BIG COUNTRY. WILL KEEP ISOLATED CONVECTION IN THE FORECAST
THROUGH EARLY EVENING WITH ACTIVITY EXPECTED TO DISSIPATE AFTER
SUNSET WITH LOSS OF HEATING.
CONVECTION HAS ALSO DEVELOPED ACROSS THE HIGHER TERRAIN IN EASTERN
NEW MEXICO THIS AFTERNOON. LATEST NAM AND HRRR INDICATE THAT THIS
ACTIVITY MAY MAKE A RUN AT OUR WESTERN COUNTIES TOWARDS DAYBREAK
THURSDAY AS IT WEAKENS. NOT CONFIDENT THAT THIS WILL HAPPEN SO KEPT
THE FORECAST DRY OVERNIGHT. DRY AND HOT CONDITIONS CONTINUE THURSDAY
AFTERNOON WITH HIGHS 99 TO 102 AND HEAT INDICES 102 TO 105 DEGREES.
24
.LONG TERM...
HOT AND DRY CONDITIONS WILL DOMINATE THE WEATHER ACROSS WEST CENTRAL
TEXAS FROM FRIDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. THE
SURFACE HIGH THAT IS CURRENTLY CENTERED OVER NEW MEXICO WILL
REPOSITION ITSELF OVER TEXAS THROUGH AT LEAST THE NEXT 7 DAYS. THIS
WILL RESULT IN NEAR NIL RAIN CHANCES...WITH HIGH TEMPERATURES
RANGING FROM 98 TO 103...WHILE OVERNIGHT LOWS FALL INTO THE MID AND
UPPER 70S. VERY LITTLE RELIEF IN THE HOT AND DRY PATTERN IS EXPECTED
THROUGH THE NEXT 7 DAYS...AND POSSIBLY BEYOND...AS THE UPPER LEVEL
HIGH REMAINS PARKED OVER THE LONE STAR STATE.
DANIELS
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 76 100 75 101 75 / 10 5 0 0 0
SAN ANGELO 75 101 75 101 74 / 20 5 0 0 0
JUNCTION 75 99 73 99 72 / 10 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
24/DANIELS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
202 PM EDT WED JUL 31 2013
.SYNOPSIS...
AN UPPER-LEVEL DISTURBANCE WILL TRACK FROM THE TENNESSEE VALLEY
TOWARD THE SOUTHEAST STATES THROUGH THURSDAY BRINGING RAIN TO THE
REGION TODAY ALONG WITH UNSEASONABLY COOL TEMPERATURES. A COLD
FRONT WILL MOVE THROUGH THE AREA THURSDAY...RESULTING IN
DECREASING CLOUDS AND MORE SCATTERED SHOWER ACTIVITY. WEAK HIGH
PRESSURE WILL THEN DOMINATE THROUGH SATURDAY WHEN THE NEXT COLD
FRONT ARRIVES FROM THE OHIO VALLEY. WARMER TEMPERATURES ARE
EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND WITH SCATTERED
MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1255 PM EDT WEDNESDAY...
EARLY AFTERNOON RADAR TRENDS DEPICT THE AREA OF PRECIPITATION THAT
HAS BEEN MAKING ITS WAY SLOWLY EASTWARD ACROSS THE REGION IS
CENTERED ALONG A LINE FROM NEAR MARTINSBURG VA TO LEWISBURG WV.
AREAS ALONG AND EAST OF A LYNCHBURG VA TO DANVILLE VA LINE HAVE
EXPERIENCED LITTLE IF ANY RAIN SO FAR TODAY...BUT IN THIS
AREA...COVERAGE OF RAIN WILL BE INCREASING THIS AFTERNOON.
ALSO..THIS REGION...AND WESTWARD ALONG THE VA/NC BORDER WILL SEE
INCREASING INSTABILITY...AND THE POTENTIAL FOR HEAVIER RAIN
SHOWERS AND A STRAY THUNDERSTORM OR TWO. AREAS ALONG AND WEST OF
I-77 IN VA AND NC ARE EXPERIENCING THE LEAST AMOUNT OF
PRECIPITATION CURRENTLY. THIS AREA WILL SEE AN INCREASE IN
COVERAGE BY THE LATE AFTERNOON THANKS TO AN IMPULSE IN KY HEADING
EASTWARD...AND INCREASED INSTABILITY OVER THE NORTHERN MOUNTAINS
AND FOOTHILLS OF NC. HAVE TWEAKED THE HOURLY TEMPERATURE...DEW
POINT...WIND...AND SKY COVER THROUGH THE LATE AFTERNOON BASED UPON
THE CURRENT OBSERVATIONS AND EXPECTED TRENDS. HAVE INCREASED HIGH
TEMPERATURES BY A FEW DEGREES IN THE EAST...AND DECREASE BY A FEW
IN THE MOUNTAINS.
AS OF 1037 AM EDT WEDNESDAY...
HAVE MADE A FEW TWEAKS TO POPS FOR THE REST OF THIS MORNING BASED
ON CURRENT RADAR TRENDS...OTHERWISE CURRENT FORECAST ON-TRACK.
WHILE THE MORNING ANALYSIS SHOWS THAT THERE IS STILL PLENTY OF
SHORT WAVE ENERGY UPSTREAM...PARTICULARLY OVER THE SOUTHERN
APPALACHIANS...NOTED THAT THE LATEST HRRR RUN SHOWS THE BEST
COVERAGE OF NEW PRECIP DEVELOPMENT OCCURRING ACROSS THE SOUTH-
CENTRAL AND EASTERN ZONES LATER THIS AFTERNOON.
PREV DISC AS OF 430 AM EDT WEDNESDAY...
FOCUS FOR THE NEAR TERM WILL BE ONUPPER DISTURBANCE TRACKING FROM
THE TENNESSEE VALLEY SE TOWARD GA/SC THROUGH EARLY THU. AS
EXPECTED FOR THE PAST SEVERAL DAYS...THIS WILL BE MAINLY A -RA
EVENT FOR OUR CWA...WITH VERY LIMITED HEATING AND AN IN SITU WEDGE
DEVELOPING FROM EXTENSIVE CLOUD COVER AND -RA FALLING INTO THE
RELATIVELY DRY AIR FOR THE END OF JULY...ONLY EXPECTING -RA WITH
ISOLD MODERATE RA THROUGH 12Z THU. WHILE THERE ARE SOME
DIFFERENCES BETWEEN THE GFS/ECMWF/CMC WITH A COOLER/LESS QPF
SOLUTION AS COMPARED TO THE MUCH WETTER/STORMIER NAM...HAVE LEANED
HEAVILY TOWARD THE GFS/ECMWF/CMC SUITE WITH NEAR ZERO INSTABILITY
INDICATED TODAY PER EARLIER THINKING. CONSEQUENTLY...HAVE REMOVED
ALL MENTION OF TSRA WITH THIS PACKAGE THROUGH 12Z THU. OVERALL
RAINFALL FOR MOST OF THE CWA SHOULD BE IN THE 0.5 TO 1.0 INCH
RANGE AT BEST WITH -RA DOMINATING MOST OF THE TIME. NOTE...LATEST
1-2 DAY WPC QPF MOSTLY ONE INCH OR LESS. THUS...NO CONCERNS FOR OR
NEED FOR A FLASH FLOOD WATCH WITHIN THIS PERIOD.
HAVE CONTINUED THE TREND OF ADVERTISING BELOW TO MUCH BELOW NORMAL
TEMPERATURES TODAY PER REASONING NOTED ABOVE OF IN SITU WEDGE
FROM CLOUDS AND RAIN BEGINNING EARLY...WITH DEWPOINTS STILL IN THE
MID 50S TO LOWER 60S...RATHER LOW FOR LATE JULY. DIURNAL RANGE
WILL BE LIMITED AND COOLING OVERNIGHT INTO THU MORNING WILL ALSO
BE LIMITED...WITH MOST AREAS AT LEAST 5 DEG WARMER THAN THIS
MORNING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 232 PM EDT TUESDAY...
ANOTHER WEAK UPPER WAVE REINFORCING TROUGH WITH ASSOCIATE SURFACE
FRONT TO PUSH THROUGH ON THURSDAY. SOME SIGNS THIS WILL CONTINUE
TO TAP SOME GULF MOISTURE BUT NOTHING LIKE WHAT WE SAW THIS PAST
WEEKEND AND LOOKS TO BE A PROGRESSIVE SYSTEM SO PREFER FASTER
SOLUTIONS...WHICH ARE ECMWF AND NAM VS. SLOWER GFS. PRECIP COULD
MOVE EAST OF FCST AREA BY 21Z BUT HAVE LEFT SOME LOW CHC POPS IN
THROUGH 03Z DUE TO SOME UNCERTAINTY...BUT FEELING IS THIS IS
LIKELY TO MOVE THROUGH FASTER VS. SLOWER. WE SHOULD LOSE ANY WEAK
WEDGE AHEAD OF THE FRONT BY MORNING...SO MODEST INSTABILITY
ESPECIALLY OUT EAST AHEAD OF FRONT FROM MIDDAY ONWARD...SO THUNDER
IN GRIDS AFTER 15Z AND HIGHEST QPF AHEAD OF FRONT IN FAR EAST BY
AFTERNOON. NOT READY TO GO CATEGORICAL...MAINLY DUE TO THE
LINGERING UNCERTAINTY IN TIMING AND WHERE ALONG FRONT THERE MIGHT
BE MORE CONTINUOUS COVERAGE VS. SCATTERED SHOWERS/STORMS. AT THIS
POINT SEVERE CHANCES LOOK MINIMAL GIVEN MODERATE INSTABILITY AND
FAIRLY WEAK SHEAR. ALSO DOES NOT APPEAR CONVECTION ORGANIZED
ENOUGH FOR MUCH OF A FLASH FLOOD THREAT...NOR IS THERE ANY UPSLOPE
COMPONENT ALONG BLUE RIDGE AND AREAS OF CONVECTION SHOULD BE
MOVING QUICKLY WITH FRONTAL BOUNDARY. TEMPERATURES IN MOST PLACES
SHOULD BE ON COOL SIDE OF GUIDANCE...BUT WILL HAVE TO CONSIDER
POTENTIAL FOR DECENT AMOUNT OF SUN IN THE WEST IF FRONT MOVES
FASTER...EXCEPT FOR FAR WESTERN SLOPES WHERE CLOUDS AND A FEW
SHOWERS COULD LINGER. SO SOME SPOTS IN WESTERN VALLEYS MAY WARM TO
AS MUCH OR HIGHER THAN PIEDMONT...DEPENDING ON TIMING OF
FRONT...LINGERING PRECIP EAST IN AFTERNOON...AND SUNSHINE IN WEST.
SOMEWHAT DRIER AIR BUT NOT NECESSARILY MUCH COOLER AIRMASS BEHIND
FRONT FOR THURS NIGHT INTO FRIDAY. DOWNSLOPE AND MORE SUN SHOULD
CONTRIBUTE TO WARMER TEMPS...ESPECIALLY OUT EAST BUT PROBABLY
EVERYWHERE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 420 AM EDT WEDNESDAY...
ANOTHER FRONT TO SLIDE DOWN FROM NORTH BY END OF WEEKEND WITH WAVE
POSSIBLY BRINGING SHOWERS IN AHEAD OF IT AS EARLY AS SATURDAY
MORNING. TRICKY TO KNOW THIS FAR OUT JUST HOW MUCH THIS FRONT WILL
SAG SOUTH ACROSS FCST AREA...AND WHETHER BY LATE SUNDAY IT WILL
ACTUALLY DROP SOUTH OF THE AREA OR STALL ACROSS US...BUT LATEST
TRENDS SUGGEST IT MAY TRY TO MAKE IT THROUGH THUS MADE SOME
ADJUSTMENTS TO POPS BASED ON THIS. TEMPS LIKELY AT OR JUST BELOW
NORMAL THROUGH WEEKEND AND INTO EARLY NEXT WEEK WITH THE EFFECTS OF
THIS FRONTAL BOUNDARY PASSING THROUGH...AND THEN THE POSSIBILITY OF
LIFTING BACK ACROSS US AS A WARM FRONT BRINGING PRECIP CHANCES
AROUND WITH ONLY A SHORT BREAK...IF ANY...LATE SUNDAY INTO MONDAY.
MUCH UNCERTAINTY AT THIS TIME HOWEVER.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 145 PM EDT WEDNESDAY...
EXPANSIVE AREA OF LIGHT RAIN CONTINUES TO PROGRESS EAST ACROSS THE
REGION WITH THE GREATEST CONCENTRATION ALONG A LINE FROM KLWB-
KLYH. MOST AREAS WITHIN THIS REGION OF RAIN ARE EXPERIENCING VFR
CONDITIONS WITH POCKETS OF MVFR CIGS/VSBYS. WEST OF THE MAIN RAIN
AREA...THERE IS A GREATER EXPANSE OF MVFR CONDITIONS WITH EITHER
DRIZZLE OR VERY PATCHY LIGHT RAIN. AS THE DAY PROGRESSESS...MODEL
GUIDANCE SUGGESTS AREAS ALONG AND EAST OF A KLYH-KDAN LINE...AND
ALONG AND SOUTH OF A KDAH-KGEV LINE MAY BECOME UNSTABLE ENOUGH FOR
DISTINCT HEAVIER RAIN SHOWERS AND POSSIBLY A THUNDERSTORM OR TWO.
AS WE PROGRESS INTO THE OVERNIGHT HOURS...LOW PRESSURE WILL
PROGRESS FROM KENTUCKY TO PENNSYLVANIA WHICH WILL BRING A WARM
FRONT NORTH THROUGH THE REGION ON THE EAST SIDE OF THE LOW. WE ARE
EXPECTING A GENERAL TREND TOWARD LOWERING FLIGHT CONDITIONS
DURING THIS PERIOD TO IFR AT MOST LOCATIONS ALONG WITH PATCHY
LIGHT RAIN...DRIZZLE AND MIST/FOG. WINDS DURING THE PERIOD WILL
REMAIN LIGHT AND VARIABLE BUT TREND LIGHT FROM THE SOUTHWEST
TOWARD DAYBREAK THURSDAY.
THE COLD FRONT ASSOCIATED WITH THE LOW IS EXPECTED TO MOVE INTO
THE WESTERN PART OF THE AREA AFTER 12Z/8AM THURSDAY. ANTICIPATE
WINDS TO BECOME WESTERLY LATE IN THE MORNING NEAR A KLWB-KBLF
LINE. FLIGHT CATEGORIES WILL GRADUALLY IMPROVE THROUGH THE MORNING
HEAD OF THE COLD FRONT...BUT ONCE THE FRONT MOVES THROUGH WESTERN
TERMINAL LOCATIONS...ANTICIPATE A QUICKER RATE. SHOWERS WILL BE
POSSIBLE ALONG THE FRONT BY LATE MORNING...WITH SOME ISOLATED
THUNDERSTORMS BY THE EARLY AFTERNOON.
THE INFLUENCE OF THE FRONT WILL CONTINUE TO PROVIDE SHOWERS ACROSS
PARTS OF THE REGION INTO THURSDAY EVENING...ESPECIALLY IN THE
EAST.
HIGH PRESSURE STARTS BUILDING INTO THE AREA BY LATE THURSDAY
NIGHT AND CONTIUE OVER THE AREA THROUGH EARLY SATURDAY. MAINLY VFR
CONDITIONS ARE EXPECTED DURING THIS PERIOD EXCEPT LATE AT NIGHT
AND EARLY MORNING HOURS WHEN MOUNTAIN AND RIVER VALLEY FOG WILL BE
POSSIBLE.
THE NEXT COLD FRONT IS PROGGED TO MOVE THROUGH THE AREA SATURDAY
EVENING INTO SUNDAY MORNING. ANTICPATE A RETURN OF SCATTERED
SHOWERS AND STORMS AND SOME AREAS OF SUB-VFR CONDITIONS.
HIGH PRESSURE AND MAINLY VFR CONDITIONS RETURN BY MONDAY. EARLY
MORNING FOG WILL AGAIN BE A POSSIBILITY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...DS/NP/RAB
SHORT TERM...SK
LONG TERM...RCS/SK
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1257 PM EDT WED JUL 31 2013
.SYNOPSIS...
AN UPPER-LEVEL DISTURBANCE WILL TRACK FROM THE TENNESSEE VALLEY
TOWARD THE SOUTHEAST STATES THROUGH THURSDAY BRINGING RAIN TO THE
REGION TODAY ALONG WITH UNSEASONABLY COOL TEMPERATURES. A COLD
FRONT WILL MOVE THROUGH THE AREA THURSDAY...RESULTING IN
DECREASING CLOUDS AND MORE SCATTERED SHOWER ACTIVITY. WEAK HIGH
PRESSURE WILL THEN DOMINATE THROUGH SATURDAY WHEN THE NEXT COLD
FRONT ARRIVES FROM THE OHIO VALLEY. WARMER TEMPERATURES ARE
EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND WITH SCATTERED
MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1255 PM EDT WEDNESDAY...
EARLY AFTERNOON RADAR TRENDS DEPICT THE AREA OF PRECIPITATION THAT
HAS BEEN MAKING ITS WAY SLOWLY EASTWARD ACROSS THE REGION IS
CENTERED ALONG A LINE FROM NEAR MARTINSBURG VA TO LEWISBURG WV.
AREAS ALONG AND EAST OF A LYNCHBURG VA TO DANVILLE VA LINE HAVE
EXPERIENCED LITTLE IF ANY RAIN SO FAR TODAY...BUT IN THIS
AREA...COVERAGE OF RAIN WILL BE INCREASING THIS AFTERNOON.
ALSO..THIS REGION...AND WESTWARD ALONG THE VA/NC BORDER WILL SEE
INCREASING INSTABILITY...AND THE POTENTIAL FOR HEAVIER RAIN
SHOWERS AND A STRAY THUNDERSTORM OR TWO. AREAS ALONG AND WEST OF
I-77 IN VA AND NC ARE EXPERIENCING THE LEAST AMOUNT OF
PRECIPITATION CURRENTLY. THIS AREA WILL SEE AN INCREASE IN
COVERAGE BY THE LATE AFTERNOON THANKS TO AN IMPULSE IN KY HEADING
EASTWARD...AND INCREASED INSTABILITY OVER THE NORTHERN MOUNTAINS
AND FOOTHILLS OF NC. HAVE TWEAKED THE HOURLY TEMPERATURE...DEW
POINT...WIND...AND SKY COVER THROUGH THE LATE AFTERNOON BASED UPON
THE CURRENT OBSERVATIONS AND EXPECTED TRENDS. HAVE INCREASED HIGH
TEMPERATURES BY A FEW DEGREES IN THE EAST...AND DECREASE BY A FEW
IN THE MOUNTAINS.
AS OF 1037 AM EDT WEDNESDAY...
HAVE MADE A FEW TWEAKS TO POPS FOR THE REST OF THIS MORNING BASED
ON CURRENT RADAR TRENDS...OTHERWISE CURRENT FORECAST ON-TRACK.
WHILE THE MORNING ANALYSIS SHOWS THAT THERE IS STILL PLENTY OF
SHORT WAVE ENERGY UPSTREAM...PARTICULARLY OVER THE SOUTHERN
APPALACHIANS...NOTED THAT THE LATEST HRRR RUN SHOWS THE BEST
COVERAGE OF NEW PRECIP DEVELOPMENT OCCURRING ACROSS THE SOUTH-
CENTRAL AND EASTERN ZONES LATER THIS AFTERNOON.
PREV DISC AS OF 430 AM EDT WEDNESDAY...
FOCUS FOR THE NEAR TERM WILL BE ONUPPER DISTURBANCE TRACKING FROM
THE TENNESSEE VALLEY SE TOWARD GA/SC THROUGH EARLY THU. AS
EXPECTED FOR THE PAST SEVERAL DAYS...THIS WILL BE MAINLY A -RA
EVENT FOR OUR CWA...WITH VERY LIMITED HEATING AND AN IN SITU WEDGE
DEVELOPING FROM EXTENSIVE CLOUD COVER AND -RA FALLING INTO THE
RELATIVELY DRY AIR FOR THE END OF JULY...ONLY EXPECTING -RA WITH
ISOLD MODERATE RA THROUGH 12Z THU. WHILE THERE ARE SOME
DIFFERENCES BETWEEN THE GFS/ECMWF/CMC WITH A COOLER/LESS QPF
SOLUTION AS COMPARED TO THE MUCH WETTER/STORMIER NAM...HAVE LEANED
HEAVILY TOWARD THE GFS/ECMWF/CMC SUITE WITH NEAR ZERO INSTABILITY
INDICATED TODAY PER EARLIER THINKING. CONSEQUENTLY...HAVE REMOVED
ALL MENTION OF TSRA WITH THIS PACKAGE THROUGH 12Z THU. OVERALL
RAINFALL FOR MOST OF THE CWA SHOULD BE IN THE 0.5 TO 1.0 INCH
RANGE AT BEST WITH -RA DOMINATING MOST OF THE TIME. NOTE...LATEST
1-2 DAY WPC QPF MOSTLY ONE INCH OR LESS. THUS...NO CONCERNS FOR OR
NEED FOR A FLASH FLOOD WATCH WITHIN THIS PERIOD.
HAVE CONTINUED THE TREND OF ADVERTISING BELOW TO MUCH BELOW NORMAL
TEMPERATURES TODAY PER REASONING NOTED ABOVE OF IN SITU WEDGE
FROM CLOUDS AND RAIN BEGINNING EARLY...WITH DEWPOINTS STILL IN THE
MID 50S TO LOWER 60S...RATHER LOW FOR LATE JULY. DIURNAL RANGE
WILL BE LIMITED AND COOLING OVERNIGHT INTO THU MORNING WILL ALSO
BE LIMITED...WITH MOST AREAS AT LEAST 5 DEG WARMER THAN THIS
MORNING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 232 PM EDT TUESDAY...
ANOTHER WEAK UPPER WAVE REINFORCING TROUGH WITH ASSOCIATE SURFACE
FRONT TO PUSH THROUGH ON THURSDAY. SOME SIGNS THIS WILL CONTINUE
TO TAP SOME GULF MOISTURE BUT NOTHING LIKE WHAT WE SAW THIS PAST
WEEKEND AND LOOKS TO BE A PROGRESSIVE SYSTEM SO PREFER FASTER
SOLUTIONS...WHICH ARE ECMWF AND NAM VS. SLOWER GFS. PRECIP COULD
MOVE EAST OF FCST AREA BY 21Z BUT HAVE LEFT SOME LOW CHC POPS IN
THROUGH 03Z DUE TO SOME UNCERTAINTY...BUT FEELING IS THIS IS
LIKELY TO MOVE THROUGH FASTER VS. SLOWER. WE SHOULD LOSE ANY WEAK
WEDGE AHEAD OF THE FRONT BY MORNING...SO MODEST INSTABILITY
ESPECIALLY OUT EAST AHEAD OF FRONT FROM MIDDAY ONWARD...SO THUNDER
IN GRIDS AFTER 15Z AND HIGHEST QPF AHEAD OF FRONT IN FAR EAST BY
AFTERNOON. NOT READY TO GO CATEGORICAL...MAINLY DUE TO THE
LINGERING UNCERTAINTY IN TIMING AND WHERE ALONG FRONT THERE MIGHT
BE MORE CONTINUOUS COVERAGE VS. SCATTERED SHOWERS/STORMS. AT THIS
POINT SEVERE CHANCES LOOK MINIMAL GIVEN MODERATE INSTABILITY AND
FAIRLY WEAK SHEAR. ALSO DOES NOT APPEAR CONVECTION ORGANIZED
ENOUGH FOR MUCH OF A FLASH FLOOD THREAT...NOR IS THERE ANY UPSLOPE
COMPONENT ALONG BLUE RIDGE AND AREAS OF CONVECTION SHOULD BE
MOVING QUICKLY WITH FRONTAL BOUNDARY. TEMPERATURES IN MOST PLACES
SHOULD BE ON COOL SIDE OF GUIDANCE...BUT WILL HAVE TO CONSIDER
POTENTIAL FOR DECENT AMOUNT OF SUN IN THE WEST IF FRONT MOVES
FASTER...EXCEPT FOR FAR WESTERN SLOPES WHERE CLOUDS AND A FEW
SHOWERS COULD LINGER. SO SOME SPOTS IN WESTERN VALLEYS MAY WARM TO
AS MUCH OR HIGHER THAN PIEDMONT...DEPENDING ON TIMING OF
FRONT...LINGERING PRECIP EAST IN AFTERNOON...AND SUNSHINE IN WEST.
SOMEWHAT DRIER AIR BUT NOT NECESSARILY MUCH COOLER AIRMASS BEHIND
FRONT FOR THURS NIGHT INTO FRIDAY. DOWNSLOPE AND MORE SUN SHOULD
CONTRIBUTE TO WARMER TEMPS...ESPECIALLY OUT EAST BUT PROBABLY
EVERYWHERE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 420 AM EDT WEDNESDAY...
ANOTHER FRONT TO SLIDE DOWN FROM NORTH BY END OF WEEKEND WITH WAVE
POSSIBLY BRINGING SHOWERS IN AHEAD OF IT AS EARLY AS SATURDAY
MORNING. TRICKY TO KNOW THIS FAR OUT JUST HOW MUCH THIS FRONT WILL
SAG SOUTH ACROSS FCST AREA...AND WHETHER BY LATE SUNDAY IT WILL
ACTUALLY DROP SOUTH OF THE AREA OR STALL ACROSS US...BUT LATEST
TRENDS SUGGEST IT MAY TRY TO MAKE IT THROUGH THUS MADE SOME
ADJUSTMENTS TO POPS BASED ON THIS. TEMPS LIKELY AT OR JUST BELOW
NORMAL THROUGH WEEKEND AND INTO EARLY NEXT WEEK WITH THE EFFECTS OF
THIS FRONTAL BOUNDARY PASSING THROUGH...AND THEN THE POSSIBILITY OF
LIFTING BACK ACROSS US AS A WARM FRONT BRINGING PRECIP CHANCES
AROUND WITH ONLY A SHORT BREAK...IF ANY...LATE SUNDAY INTO MONDAY.
MUCH UNCERTAINTY AT THIS TIME HOWEVER.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 745 AM EDT WEDNESDAY...
-RA CONTINUED TO SPREAD ACROSS THE CWA FROM W-E WITH MID/HIGH VFR
CIGS. HAVE YET TO SEE ANY CLOUDS MUCH BELOW 050 ANYWHERE...MOST
AOA 080. VSBYS MOSTLY VFR WITH PCPN FALLING FROM HIGH BASED CIGS
WITH SPOTTY GROUND FOG LWB/LYH/BCB. EXPECT WIDESPREAD -RA TO
CONTINUE TO OVERSPREAD THE AREA FROM W-E INTO MID- MORNING WITH
MOSTLY VFR TO HIGH END MVFR CIGS...GENERALLY AOA035. AS THE
INSITU WEDGE EVOLVES THROUGH THE DAY...EXPECT CIGS TO LOWER TOWARD
MVFR TOWARD EVENING AND ESPECIALLY TOWARD 06Z. MODELS HINT THAT
BULK OF PCPN MAY PASS THROUGH THE CWA IN THE 12Z-20Z TIME
FRAME...MOVING EAST OF THE CWA AFT 20Z. AM CONCERNED THAT THERE
MAY BE -DZ OVERNIGHT IN THE LYH/ROA/BCB AREA...WITH ATTENDING
LOWER VSBYS AS A RESULT. OCCASIONAL MVFR VSBYS CAN BE EXPECTED
THROUGH THE DAYTIME IN -RA BR. WINDS FAVORING A SSE-SSW DIRECTION
WITH SPEEDS MOSTLY AOB 5KTS. HAVE REMOVED ALL MENTION OF TSRA AS
GFS AT LEAST SHOWS NEAR ZERO INSTABILITY TODAY AND WITH AN INSITU
WEDGE AND EXTENSIVE CLOUD COVER/LIGHT PCPN...WOULD NOT EXPECT
ENOUGH INSTABILITY TO BE REALIZED FOR TSRA. IF THERE WERE...ONLY
DAN WOULD SEEM TO HAVE THE POTENTIAL FOR SUCH.
MEDIUM TO HIGH CONFIDENCE IN CIGS THROUGH 00Z...THEN MEDIUM
CONFIDENCE.
MEDIUM CONFIDENCE IN VSBYS THROUGH TAF VALID PERIOD.
HIGH CONFIDENCE IN WIND SPD THROUGH TAF VALID PERIOD.
MEDIUM CONFIDENCE IN WIND DIR THROUGH TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN LITTLE TO NO THUNDER AT TAF SITES
THROUGH TAF VALID PERIOD.
EXTENDED AVIATION DISCUSSION...
COLD FRONT ARRIVES THURSDAY WITH POTENTIAL FOR DEEPER CONVECTION
ESPCLY EAST OF THE BLUE RIDGE THURSDAY AFTERNOON. THIS FRONT WILL
PUSH SOUTHEAST OF US THURSDAY NIGHT WITH VFR RETURNING...OUTSIDE
FOG IN THE MORNINGS AT TYPICAL SITES KLWB/KBCB...AND MAYBE
KLYH/KDAN GIVEN WET GROUND.
ANOTHER FRONT ARRIVES SOMETIME THIS WEEKEND AND COULD BRING
SHOWERS AND STORMS...WITH SUB-VFR AT TIMES.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...DS/NP/RAB
SHORT TERM...SK
LONG TERM...RCS/SK
AVIATION...JH/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
ISSUED BY NATIONAL WEATHER SERVICE RALEIGH NC
1037 AM EDT WED JUL 31 2013
.SYNOPSIS...
AN UPPER-LEVEL DISTURBANCE WILL TRACK FROM THE TENNESSEE VALLEY
TOWARD THE SOUTHEAST STATES THROUGH THURSDAY BRINGING RAIN TO THE
REGION TODAY ALONG WITH UNSEASONABLY COOL TEMPERATURES. A COLD
FRONT WILL MOVE THROUGH THE AREA THURSDAY...RESULTING IN
DECREASING CLOUDS AND MORE SCATTERED SHOWER ACTIVITY. WEAK HIGH
PRESSURE WILL THEN DOMINATE THROUGH SATURDAY WHEN THE NEXT COLD
FRONT ARRIVES FROM THE OHIO VALLEY. WARMER TEMPERATURES ARE
EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND WITH SCATTERED
MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1037 AM EDT WEDNESDAY...
HAVE MADE A FEW TWEAKS TO POPS FOR THE REST OF THIS MORNING BASED
ON CURRENT RADAR TRENDS...OTHERWISE CURRENT FORECAST ON-TRACK.
WHILE THE MORNING ANALYSIS SHOWS THAT THERE IS STILL PLENTY OF
SHORT WAVE ENERGY UPSTREAM...PARTICULARLY OVER THE SOUTHERN
APPALACHIANS...NOTED THAT THE LATEST HRRR RUN SHOWS THE BEST
COVERAGE OF NEW PRECIP DEVELOPMENT OCCURRING ACROSS THE SOUTH-
CENTRAL AND EASTERN ZONES LATER THIS AFTERNOON.
PREV DISC AS OF 430 AM EDT WEDNESDAY...
FOCUS FOR THE NEAR TERM WILL BE ONUPPER DISTURBANCE TRACKING FROM
THE TENNESSEE VALLEY SE TOWARD GA/SC THROUGH EARLY THU. AS
EXPECTED FOR THE PAST SEVERAL DAYS...THIS WILL BE MAINLY A -RA
EVENT FOR OUR CWA...WITH VERY LIMITED HEATING AND AN IN SITU WEDGE
DEVELOPING FROM EXTENSIVE CLOUD COVER AND -RA FALLING INTO THE
RELATIVELY DRY AIR FOR THE END OF JULY...ONLY EXPECTING -RA WITH
ISOLD MODERATE RA THROUGH 12Z THU. WHILE THERE ARE SOME
DIFFERENCES BETWEEN THE GFS/ECMWF/CMC WITH A COOLER/LESS QPF
SOLUTION AS COMPARED TO THE MUCH WETTER/STORMIER NAM...HAVE LEANED
HEAVILY TOWARD THE GFS/ECMWF/CMC SUITE WITH NEAR ZERO INSTABILITY
INDICATED TODAY PER EARLIER THINKING. CONSEQUENTLY...HAVE REMOVED
ALL MENTION OF TSRA WITH THIS PACKAGE THROUGH 12Z THU. OVERALL
RAINFALL FOR MOST OF THE CWA SHOULD BE IN THE 0.5 TO 1.0 INCH
RANGE AT BEST WITH -RA DOMINATING MOST OF THE TIME. NOTE...LATEST
1-2 DAY WPC QPF MOSTLY ONE INCH OR LESS. THUS...NO CONCERNS FOR OR
NEED FOR A FLASH FLOOD WATCH WITHIN THIS PERIOD.
HAVE CONTINUED THE TREND OF ADVERTISING BELOW TO MUCH BELOW NORMAL
TEMPERATURES TODAY PER REASONING NOTED ABOVE OF IN SITU WEDGE
FROM CLOUDS AND RAIN BEGINNING EARLY...WITH DEWPOINTS STILL IN THE
MID 50S TO LOWER 60S...RATHER LOW FOR LATE JULY. DIURNAL RANGE
WILL BE LIMITED AND COOLING OVERNIGHT INTO THU MORNING WILL ALSO
BE LIMITED...WITH MOST AREAS AT LEAST 5 DEG WARMER THAN THIS
MORNING.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 232 PM EDT TUESDAY...
ANOTHER WEAK UPPER WAVE REINFORCING TROUGH WITH ASSOCIATE SURFACE
FRONT TO PUSH THROUGH ON THURSDAY. SOME SIGNS THIS WILL CONTINUE
TO TAP SOME GULF MOISTURE BUT NOTHING LIKE WHAT WE SAW THIS PAST
WEEKEND AND LOOKS TO BE A PROGRESSIVE SYSTEM SO PREFER FASTER
SOLUTIONS...WHICH ARE ECMWF AND NAM VS. SLOWER GFS. PRECIP COULD
MOVE EAST OF FCST AREA BY 21Z BUT HAVE LEFT SOME LOW CHC POPS IN
THROUGH 03Z DUE TO SOME UNCERTAINTY...BUT FEELING IS THIS IS
LIKELY TO MOVE THROUGH FASTER VS. SLOWER. WE SHOULD LOSE ANY WEAK
WEDGE AHEAD OF THE FRONT BY MORNING...SO MODEST INSTABILITY
ESPECIALLY OUT EAST AHEAD OF FRONT FROM MIDDAY ONWARD...SO THUNDER
IN GRIDS AFTER 15Z AND HIGHEST QPF AHEAD OF FRONT IN FAR EAST BY
AFTERNOON. NOT READY TO GO CATEGORICAL...MAINLY DUE TO THE
LINGERING UNCERTAINTY IN TIMING AND WHERE ALONG FRONT THERE MIGHT
BE MORE CONTINUOUS COVERAGE VS. SCATTERED SHOWERS/STORMS. AT THIS
POINT SEVERE CHANCES LOOK MINIMAL GIVEN MODERATE INSTABILITY AND
FAIRLY WEAK SHEAR. ALSO DOES NOT APPEAR CONVECTION ORGANIZED
ENOUGH FOR MUCH OF A FLASH FLOOD THREAT...NOR IS THERE ANY UPSLOPE
COMPONENT ALONG BLUE RIDGE AND AREAS OF CONVECTION SHOULD BE
MOVING QUICKLY WITH FRONTAL BOUNDARY. TEMPERATURES IN MOST PLACES
SHOULD BE ON COOL SIDE OF GUIDANCE...BUT WILL HAVE TO CONSIDER
POTENTIAL FOR DECENT AMOUNT OF SUN IN THE WEST IF FRONT MOVES
FASTER...EXCEPT FOR FAR WESTERN SLOPES WHERE CLOUDS AND A FEW
SHOWERS COULD LINGER. SO SOME SPOTS IN WESTERN VALLEYS MAY WARM TO
AS MUCH OR HIGHER THAN PIEDMONT...DEPENDING ON TIMING OF
FRONT...LINGERING PRECIP EAST IN AFTERNOON...AND SUNSHINE IN WEST.
SOMEWHAT DRIER AIR BUT NOT NECESSARILY MUCH COOLER AIRMASS BEHIND
FRONT FOR THURS NIGHT INTO FRIDAY. DOWNSLOPE AND MORE SUN SHOULD
CONTRIBUTE TO WARMER TEMPS...ESPECIALLY OUT EAST BUT PROBABLY
EVERYWHERE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 420 AM EDT WEDNESDAY...
ANOTHER FRONT TO SLIDE DOWN FROM NORTH BY END OF WEEKEND WITH WAVE
POSSIBLY BRINGING SHOWERS IN AHEAD OF IT AS EARLY AS SATURDAY
MORNING. TRICKY TO KNOW THIS FAR OUT JUST HOW MUCH THIS FRONT WILL
SAG SOUTH ACROSS FCST AREA...AND WHETHER BY LATE SUNDAY IT WILL
ACTUALLY DROP SOUTH OF THE AREA OR STALL ACROSS US...BUT LATEST
TRENDS SUGGEST IT MAY TRY TO MAKE IT THROUGH THUS MADE SOME
ADJUSTMENTS TO POPS BASED ON THIS. TEMPS LIKELY AT OR JUST BELOW
NORMAL THROUGH WEEKEND AND INTO EARLY NEXT WEEK WITH THE EFFECTS OF
THIS FRONTAL BOUNDARY PASSING THROUGH...AND THEN THE POSSIBILITY OF
LIFTING BACK ACROSS US AS A WARM FRONT BRINGING PRECIP CHANCES
AROUND WITH ONLY A SHORT BREAK...IF ANY...LATE SUNDAY INTO MONDAY.
MUCH UNCERTAINTY AT THIS TIME HOWEVER.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 AM EDT WEDNESDAY...
-RA CONTINUED TO SPREAD ACROSS THE CWA FROM W-E WITH MID/HIGH VFR
CIGS. HAVE YET TO SEE ANY CLOUDS MUCH BELOW 050 ANYWHERE...MOST
AOA 080. VSBYS MOSTLY VFR WITH PCPN FALLING FROM HIGH BASED CIGS
WITH SPOTTY GROUND FOG LWB/LYH/BCB. EXPECT WIDESPREAD -RA TO
CONTINUE TO OVERSPREAD THE AREA FROM W-E INTO MID- MORNING WITH
MOSTLY VFR TO HIGH END MVFR CIGS...GENERALLY AOA035. AS THE
INSITU WEDGE EVOLVES THROUGH THE DAY...EXPECT CIGS TO LOWER TOWARD
MVFR TOWARD EVENING AND ESPECIALLY TOWARD 06Z. MODELS HINT THAT
BULK OF PCPN MAY PASS THROUGH THE CWA IN THE 12Z-20Z TIME
FRAME...MOVING EAST OF THE CWA AFT 20Z. AM CONCERNED THAT THERE
MAY BE -DZ OVERNIGHT IN THE LYH/ROA/BCB AREA...WITH ATTENDING
LOWER VSBYS AS A RESULT. OCCASIONAL MVFR VSBYS CAN BE EXPECTED
THROUGH THE DAYTIME IN -RA BR. WINDS FAVORING A SSE-SSW DIRECTION
WITH SPEEDS MOSTLY AOB 5KTS. HAVE REMOVED ALL MENTION OF TSRA AS
GFS AT LEAST SHOWS NEAR ZERO INSTABILITY TODAY AND WITH AN INSITU
WEDGE AND EXTENSIVE CLOUD COVER/LIGHT PCPN...WOULD NOT EXPECT
ENOUGH INSTABILITY TO BE REALIZED FOR TSRA. IF THERE WERE...ONLY
DAN WOULD SEEM TO HAVE THE POTENTIAL FOR SUCH.
MEDIUM TO HIGH CONFIDENCE IN CIGS THROUGH 00Z...THEN MEDIUM
CONFIDENCE.
MEDIUM CONFIDENCE IN VSBYS THROUGH TAF VALID PERIOD.
HIGH CONFIDENCE IN WIND SPD THROUGH TAF VALID PERIOD.
MEDIUM CONFIDENCE IN WIND DIR THROUGH TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN LITTLE TO NO THUNDER AT TAF SITES
THROUGH TAF VALID PERIOD.
EXTENDED AVIATION DISCUSSION...
COLD FRONT ARRIVES THURSDAY WITH POTENTIAL FOR DEEPER CONVECTION
ESPCLY EAST OF THE BLUE RIDGE THURSDAY AFTERNOON. THIS FRONT WILL
PUSH SOUTHEAST OF US THURSDAY NIGHT WITH VFR RETURNING...OUTSIDE
FOG IN THE MORNINGS AT TYPICAL SITES KLWB/KBCB...AND MAYBE
KLYH/KDAN GIVEN WET GROUND.
ANOTHER FRONT ARRIVES SOMETIME THIS WEEKEND AND COULD BRING
SHOWERS AND STORMS...WITH SUB-VFR AT TIMES.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...NP/RAB
SHORT TERM...SK
LONG TERM...RCS/SK
AVIATION...JH/RAB
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1045 PM CDT THU AUG 1 2013
.UPDATE...
HAVE EXPANDED THE CHANCE OF SHOWERS/THUNDERSTORMS AS THE 250 MB
UPPER JET MAX OF 110 KNOTS MOVES ACROSS WISCONSIN. 850/700 MB
MOISTURE CONVERGENCE INCREASES OVERNIGHT IN ADDITION TO THE JET
MAX.
&&
.AVIATION/06Z TAFS/...
MAINLY VFR CONDITIONS EXCEPT AN UPPER LEVEL JET MAX WILL GENERATE
AN INCREASE IN SHOWERS/THUNDERSTORMS. THIS AREA SHOULD MOVE OFF TO
THE SOUTHEAST BY MID MORNING. WEAK HIGH PRESSURE WILL THEN BUILD
IN TO THE UPPER MISSISSIPPI VALLEY FRIDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 330 PM CDT THU AUG 1 2013/
SHORT TERM...
TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
HRRR/WRF ARW MODELS SHOWING ISOLATED SHOWERS TRYING TO PUSH INTO
NORTHERN PORTIONS OF THE AREA LATE THIS AFTERNOON...WITH THE OTHER
MESOSCALE MODELS DRY. LATEST RAP FORECAST SOUNDINGS ACROSS THIS AREA
SHOWING VERY LITTLE MEAN LAYER CAPE. LACKING A TRIGGER AS WELL.
THUS...WILL KEEP LATE AFTERNOON DRY.
MESOSCALE MODELS DO DEVELOP MORE SHOWER/THUNDERSTORM ACTIVITY BY
LATER THIS EVENING INTO THE OVERNIGHT HOURS. SYNOPTIC SCALE MODELS
ALSO SHOWING QPF ACROSS AT LEAST THE SOUTHERN HALF OF THE AREA
TONIGHT INTO EARLY FRIDAY...WITH SOME HAVING IT ACROSS MOST OF THE
AREA.
THIS IS IN RESPONSE TO 850MB WARM AIR ADVECTION PUSHING INTO THE
AREA TONIGHT. SURFACE WARM FRONT APPROACHES THE AREA FROM THE
SOUTHWEST TONIGHT...AND LINGERS TO THE SOUTH ON FRIDAY. 500MB
VORTICITY MAXIMUM ALSO SLIDES SOUTHEAST AND CLIPS NORTHERN PORTIONS
OF THE AREA TONIGHT.
AREA FORECAST SOUNDINGS SHOWING SOME LOW LEVEL MOISTURE TONIGHT INTO
EARLY FRIDAY...WITH ELEVATED CAPES OF 250 TO 700 J/KG. KEPT LOW POPS
IN MOST OF THE NORTHERN COUNTIES DURING THIS TIME...WITH HIGHER POPS
IN THE SOUTH.
COLD FRONT THEN SLIDES SOUTHEAST ACROSS THE AREA ON FRIDAY...WITH
MOISTURE AND INSTABILITY BECOMING MEAGER. KEPT SIMILAR POPS FOR
FRIDAY AS FRONT MOVES THROUGH. SHOULD SEE HIGHS REACH THE UPPER 70S
TO LOWER 80S PER EXPECTED 925MB TEMPERATURES.
FRIDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM.
THE UPPER LEVEL FLOW PATTERN WILL REMAIN FAIRLY STATIONARY THROUGH
THE WEEKEND...WITH LOWS PARKED OVER THE NORTHWEST CONUS AND HUDSON
BAY...AND A HIGH OVER TEXAS WITH RIDGING UP THROUGH THE NORTHERN
PLAINS. AT THE SURFACE...HIGH PRESSURE WILL SPREAD ACROSS THE UPPER
GREAT LAKES REGION. ACTIVE WEATHER WILL STAY JUST TO THE SOUTH OF
WISCONSIN.
WE WILL CONTINUE TO FORECAST A DRY WEEKEND...DESPITE THE OUTLIER NAM
PERSISTENTLY PAINTING A SWATH OF LIGHT QPF ACROSS CENTRAL/SOUTHERN
WISCONSIN. IT IS KEYING IN ON A 500MB SHORTWAVE DROPPING THROUGH THE
UPPER MIDWEST AND IS PRODUCING STRONG 700MB OMEGA AND HIGH MOISTURE.
WILL STAY WITH THE DRY MODELS THAT OMIT THE STRONG WAA SIGNAL. THE
LOW LEVEL JET SIGNATURE AND MOISTURE IS JUST NOT THERE TO SUPPORT
PRECIP. WENT WITH HIGHER CLOUD COVER INSTEAD OF HIGHER POPS.
MAX TEMPS OVER THE WEEKEND WILL BE JUST BELOW CLIMATOLOGICAL
NORMAL...IN THE UPPER 70S. A LAKE BREEZE EACH DAY WILL KEEP
LAKESHORE TEMPS JUST A COUPLE DEGREES COOLER THAN FURTHER INLAND.
LONG TERM...
SUNDAY NIGHT THROUGH TUESDAY..FORECAST CONFIDENCE MEDIUM TO LOW.
RETURN FLOW AROUND THE SURFACE HIGH...COINCIDENT WITH SUBTLE 850MB
WARM AIR ADVECTION AND A WEAK 500MB SHORTWAVE...WILL LEAD TO A
PERIOD OF SHOWERS AND THUNDERSTORMS RETURNING TO WISCONSIN. TIMING
OF THIS IS QUITE UNCERTAIN AND COULD BE AS EARLY AS MONDAY
/CANADIAN/...BUT MAYBE NOT UNTIL MONDAY NIGHT /GFS/ OR TUESDAY
/ECMWF/. INCREASING CLOUDS WILL KEEP MAX TEMPS IN CHECK IN THE MID
70S FOR MONDAY...BUT EXPECTING A LITTLE WARMER ON TUESDAY.
WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDENCE MEDIUM TO LOW.
MODELS ARE ADVERTISING A STRONGER 500MB TROUGH DROPPING DOWN THROUGH
THE UPPER MIDWEST LATER IN THE WEEK...BRINGING ANOTHER OPPORTUNITY
FOR SHOWERS AND THUNDERSTORMS. THE UPPER LEVEL PATTERN WILL BE
PRETTY MUCH THE SAME AS IT IS NOW...SO EXPECTING TEMPS TO REMAIN
JUST A LITTLE BELOW NORMAL.
AVIATION/00Z TAFS/...
VFR CONDITIONS ARE EXPECTED ACROSS TAF SITES LATE THIS
AFTERNOON...TONIGHT AND FRIDAY. WEST NORTHWEST WINDS MAY GUST TO
AROUND 15 KNOTS AT TIMES INTO THE EARLY EVENING. SCATTERED TO BROKEN
DIURNAL CUMULUS CLOUDS WILL LINGER AS WELL. IF ANY LAKE BREEZE
DEVELOPS LATE THIS AFTERNOON...IT SHOULD REMAIN EAST OF MILWAUKEE
AND KENOSHA.
APPROACHING WARM FRONT FROM THE SOUTHWEST WILL BRING ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS INTO TAF SITES MAINLY AFTER 06Z
FRIDAY. BEST CHANCES WILL BE AFTER 12Z FRIDAY AT THE EASTERN TAF
SITES.
HOWEVER...THERE IS STILL SOME UNCERTAINTY WITH THE AREAL COVERAGE OF
THE PRECIPITATION. FOR NOW...WILL MENTION VICINITY SHOWERS/STORMS
ACROSS THE EASTERN SITES AFTER 12Z FRIDAY. MVFR/IFR
CEILINGS/VISIBILITIES WOULD BE POSSIBLE IN ANY STORMS...BUT WILL
LEAVE THIS OUT OF TAFS FOR NOW.
MARINE...
WINDS MAY TURN SOUTH TO SOUTHEAST ACROSS THE NEARSHORE WATERS OF
LAKE MICHIGAN...SOUTH OF NORTH POINT LIGHTHOUSE...LATE THIS
AFTERNOON. THEY ALSO MAY SHIFT TO THE SOUTH SOUTHWEST TO NORTH OF
THERE. THIS IS IN RESPONSE TO POSSIBLE LAKE BREEZE CIRCULATION
TRYING TO DEVELOP. HOWEVER...CURRENT WEST NORTHWEST WINDS MAY BE
STRONG ENOUGH TO NEGATE ITS DEVELOPMENT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD
FRIDAY NIGHT THROUGH THURSDAY...MRC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1017 PM CDT THU AUG 1 2013
NEW INFORMATION ADDED TO UPDATE AND AVIATION (FOR 06Z TAFS)
SECTIONS
.UPDATE...
ISSUED AT 1015 PM CDT THU AUG 1 2013
PCPN TRENDS ARE TRICKY TONIGHT...WITH TWO SEPARATE AREAS OF
FORCING TO CONTEND WITH OVERNIGHT.
LEANING TOWARD BUMPING UP POPS OVER NORTHERN WI...WHERE A FAIRLY
POTENT S/W TROF IS EXPECTED TO TRACK AFTER 06Z. LATEST HRRR AND
NAM SUPPORT A SIGNIFICANT INCREASE IN CONVECTION OVER NORTHERN WI
AFTER MIDNIGHT. WHILE MOST OF THE CONVECTION OVER THE MN ARROWHEAD
APPEARS POISED TO SHIFT ACROSS LK SUP INTO THE UPPER PENINSULA...A
SMALL CLUSTER OF SHOWERS HAS BEEN SLOWLY INCREASING OVER NW WI
DURING THE PAST HOUR. CURRENT PLAN IS TO INCREASE POPS TO CHC
CATEGORY OVER NC/NE WI OVERNIGHT...WITH THE HIGHEST POPS AND A
MENTION OF ISOLD THUNDER NEAR THE U.P. BORDER.
FARTHER SOUTH...CONVECTION THAT DEVELOPED OVER SE MN/NE IA/FAR
SW WI HAS BEEN GENERALLY SHIFTING E-ESE THIS EVG. THIS ACTIVITY
WAS SUPPORTED BY LOW-LEVEL WAA/MOISTURE CONVERGENCE. WITH LOW-
LEVEL WESTERLY FLOW IN PLACE...THINK THE BEST FORCING/MOISTURE/
INSTABILITY WILL BE FOCUSED ACROSS THE SOUTHERN THIRD OF WI...AND
PROBABLY REMAIN JUST SOUTH OF GRB CWA.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 330 PM CDT THU AUG 1 2013
WEATHER ACROSS MUCH OF THE FORECAST AREA WAS PRETTY TAME THROUGH
THE EARLY AFTERNOON HOURS. SOME SHOWERS DEVELOPED IN NORTH CENTRAL
AND NORTHEAST WISCONSIN DURING THE LATE MORNING AND EARLY
AFTERNOON HOURS...ASSOCIATED WITH AN UPPER LEVEL SHORT WAVE...AND
THE LEFT EXIT REGION OF A JET MAX. MU CAPE VALUES WERE IN EXCESS
OF 500J/KG IN PARTS OF NORTH CENTRAL AND NORTHEAST WISCONSIN WITH
LITTLE OR NO CIN...BUT MU CAPE VALUES WERE TRENDING DOWNWARD THIS
AFTERNOON.
SHOWERS SHOULD DISSIPATE WITH LOSS OF DAYTIME HEATING...BUT ANOTHER
SHORT WAVE PASSING THROUGH NORTHERN WISCONSIN DURING THE NIGHT
COULD KEEP ISOLATED SHOWERS GOING AS LATE AS 09Z IN FAR EASTERN
DOOR COUNTY. HAVE A SLIGHT CHANCE OF SHOWERS IN THE NORTH ONCE
AGAIN ON FRIDAY ASSOCIATED WITH THE NEXT SHORT WAVE.
SKIES SHOULD BE PARTLY CLOUDY ACROSS THE REST OF THE AREA. A MIX
OF THE PREVIOUS FORECAST AND BEST PERFORMING GUIDANCE WAS USED FOR
LOWS TONIGHT AND HIGHS ON FRIDAY.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 330 PM CDT THU AUG 1 2013
THE LATEST GFS ENSEMBLE MEAN INDICATES THAT THE PERSISTENT WESTERN
CANADA RIDGE WILL CONTINUE TO LEAD TO DOWNSTREAM TROUGHING FROM
HUDSON BAY AND THE GREAT LAKES ON EAST. ALL TROPICAL HEAT AND
HUMIDITY WILL REMAIN SHUNTED TO THE SOUTHERN TIER OF THE COUNTRY
OVER THIS PERIOD. UNCERTAINTIES REMAIN IN THE DETAILS FOR LATE IN
THE WEEKEND INTO EARLY NEXT WEEK WHEN A PIECE OF THE NW PAC UPPER
LOW DIVES ACROSS THE NORTHERN MISSISSIPPI VALLEY AND TRIES TO PUSH A
THERMAL GRADIENT INTO THE WESTERN GREAT LAKES. MODELS HAVE THE SAME
BIASES AS YESTERDAY (ECMWF ON THE FASTER SIDE...AND GFS ON THE
SLOWER SIDE). WILL SIDE WITH THE GFS ENSEMBLE MEAN WHICH SORT OF
SPLITS THE DIFFERENCE FOR LATER IN THE PERIOD.
FRIDAY NIGHT THROUGH SUNDAY...NORTHERN WISCONSIN WILL RESIDE ON THE
CYCLONIC SHEAR SIDE OF THE UPPER JET OVER THIS PERIOD. SEVERAL WEAK
SHORTWAVES WILL TRAVEL FROM WESTERN ONTARIO TO LAKE HURON...THE
STRONGEST OF WHICH WILL PASS ACROSS LAKE SUPERIOR ON SATURDAY. BUT
DEEP MOISTURE LOOKS TO BE LACKING WITH THIS WAVE AND MOST OF THE
MEAGER FORCING WILL REMAIN NORTH OF THE REGION. SO WITH HIGH
PRESSURE BUILDING SOUTHEAST INTO THE WESTERN GREAT LAKES...WILL
STICK WITH THE DRY FORECAST. AFTER A MOSTLY CLEAR SATURDAY
NIGHT...CLOUDS WILL BE INCREASING OVER THE NORTHERN MISSISSIPPI
VALLEY ON SUNDAY AHEAD OF THE NEXT SHORTWAVE. BUT WITH HIGH
PRESSURE OVER THE AREA AND THE THERMAL GRADIENT WELL OFF TO THE
SOUTHWEST...SHOULD SEE ANOTHER DAY OF SUNSHINE. HIGHS ON SATURDAY
AND SUNDAY WILL BE MAINLY IN THE LOWER TO MIDDLE 70S. LOWS IN THE
40S AND 50S.
REST OF THE FORECAST...THE NEXT SHORTWAVE WILL DIVE SE ACROSS THE
REGION LATE SUNDAY NIGHT INTO MONDAY. THE THERMAL GRADIENT FROM THE
NORTHERN PLAINS WILL SHIFT EAST INTO THE NORTHERN MISSISSIPPI
VALLEY...BUT TOUGH TO TELL HOW FAR EAST IT WILL REACH. POSITION OF
THE JET STREAM SUGGESTS IT WILL REMAIN TO OUR SOUTHWEST...BUT WILL
SEE. WILL KEEP POPS LOW LATE SUNDAY NIGHT INTO MONDAY NIGHT AS FORCING
LOOKS WEAK AND THERE IS LITTLE INSTABILITY. THEN THE NORTHERN
STREAM AMPLIFIES AND CLOSED UPPER LOW DROPS INTO THE LAKE SUPERIOR
REGION FOR MIDWEEK. MODELS HAVE DIFFERENT TRACKS FOR THIS UPPER LOW...BUT
THEY ADVERTISE A STRONG COLD FRONT DROPPING SOUTH ACROSS THE AREA AS
EARLY AS WEDNESDAY. TEMPERATURES TO REMAIN IN THE LOW TO MID 70S
MONDAY THROUGH WEDNESDAY...THEN POSSIBLY GETTING COLDER BY THURSDAY
DEPENDING UPON THE COLD FRONTAL PASSAGE.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1015 PM CDT THU AUG 1 2013
VFR CONDITONS ARE ANTICIPATED THROUGH THIS TAF PERIOD...ASIDE
FROM LOCAL MVFR CONDITIONS IN SHOWERS OVER NORTHERN WI LATE
TONIGHT.
SHOWERS AND SCT TSTMS WERE ONGOING OVER THE MN ARROWHEAD LATE
THIS EVG...WITH MORE ISOLD SHOWER ACTIVITY NOTED OVER NW WI AND
THE UPPER PENINSULA OF MI. OTHER CONVECTION WAS NOTED OVER SW WI.
SCT-BKN ALTOCUMULUS WAS OBSERVED OVER MOST OF THE GRB FCST AREA.
CURRENT TRENDS SUGGEST THAT SHOWERS AND POSSIBLY A FEW RUMBLES OF
THUNDER WILL AFFECT NC/NE WI OVERNIGHT...AS A FAIRLY POTENT UPPER
DISTURBANCE MOVES THROUGH. FARTHER SOUTH...THE CONVECTION OVER SW
WI SHOULD STAY MAINLY TO OUR SOUTH OVERNIGHT INTO EARLY FRI...BUT
TRENDS WILL NEED TO BE MONITORED FOR THE OSH VCNTY...AS IT COULD
GET CLOSE.
ANOTHER UPPER DISTURBANCE IS EXPECTED PASS BY TO OUR NORTH ON
FRIDAY...SO THINK MOST OF THE SHOWERS SHOULD REMAIN OVER THE
UPPER PENINSULA OF MI AND PERHAPS FAR NE WI. NORTHWEST WINDS WILL
GUST TO 15 TO 20 KTS AT THE TAF SITES DURING THE LATE MORNING AND
AFTERNOON. DRY CONDITIONS AND DECREASING WINDS ARE EXPECTED FRI
EVG.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MG
LONG TERM......MPC
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 PM CDT TUE JUL 30 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 215 PM CDT TUE JUL 30 2013
CURRENTLY AS OF 19Z...
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED SUBTROPICAL
RIDGING OVER THE SOUTHWESTERN U.S....TROUGHING OVER SASKATCHEWAN AND
MANITOBA...AND WEST-NORTHWEST FLOW FROM MONTANA INTO THE FORECAST
AREA. WITHIN THE FLOW...A FEW SHORTWAVES WERE CROSSING NORTH DAKOTA.
CONDITIONS ARE DRY ACROSS THE FORECAST AREA...BUT PLENTY OF STRATUS
OF THE LOW TO MID LEVEL VARIETY EXISTS. THESE CLOUDS HAVE HELD
TEMPERATURES DOWN SOMEWHAT...BUT ENOUGH SUN HAS MADE IT THROUGH WITH
THE 850MB TEMPS BETWEEN 11-13C PER 12Z RAOBS TO BRING READINGS INTO
THE 70S. TO THE WEST...A COLD FRONT WAS PRESENT OVER FAR WESTERN
MN...JUST AHEAD OF THE SHORTWAVES. THE COLD FRONT SO FAR HAS NOT
DONE ANYTHING PRECIPITATION WISE...BUT THERE HAS BEEN CONVECTION
BEHIND THE FRONT OVER SOUTHERN SOUTH DAKOTA.
SYNOPTIC OVERVIEW...
MODELS ARE IN VERY GOOD AGREEMENT DROPPING A PORTION OF THE
TROUGHING OVER SOUTH CENTRAL CANADA THROUGH THE FORECAST AREA
WEDNESDAY AFTERNOON. THIS PORTION OF THE TROUGH...OR SHORTWAVE...IS
OF MOST CONCERN...SINCE IT WILL PUSH THE COLD FRONT TO OUR WEST
ACROSS THE FORECAST AREA. IT APPEARS THE SHORTWAVES CURRENTLY ACROSS
NORTH DAKOTA WILL HEAD EAST TOWARDS UPPER MI.
HAZARDS...
SOME SEVERE WEATHER POTENTIAL WEDNESDAY AFTERNOON GIVEN 0-6 KM SHEAR
VALUES AROUND 40 KT PRESENT WITH A FRONTAL PASSAGE. HOWEVER...THERE
ARE SERIOUS CONCERNS ON AVAILABLE INSTABILITY AS DESCRIBED IN THE
DETAILS BELOW. SHOULD SEVERE WEATHER OCCUR...HAIL WILL BE THE MAIN
CONCERN.
DETAILS...
A LIGHT SOUTHERLY FLOW AHEAD OF THE WESTERN MN COLD FRONT WILL ALLOW
SOME OF THE LOWER CEILING STRATUS AND FOG THAT HAS PRESENT JUST
SOUTH OF THE FORECAST AREA TO COME UP INTO NORTHEAST IOWA AND FAR
SOUTHWEST WISCONSIN TONIGHT. HAVE ADDED SOME FOG MENTION TO THESE
LOCATIONS. OTHERWISE...TONIGHT LOOKS FAIRLY QUIET WITH BASICALLY NO
ISENTROPIC LIFT AND ALL SHORTWAVE FORCING HEADING UP TO THE NORTH.
ONE ITEM OF INTEREST PRESENT IN SOME PAST HRRR RUNS AS WELL AS THE
30.12Z ECMWF AND HIRES-ARW IS A BAND OF SHOWERS FROM NEAR WABASHA
COUNTY TO TAYLOR COUNTY BETWEEN 00-09Z. GIVEN THE 30.17Z HRRR RUN IS
DRY AND AFOREMENTIONED FORCING SIGNALS ARE WEAK TO NONE...HAVE KEPT
THE FORECAST DRY IN THIS AREA. A MIX OF LOW AND HIGHER STRATUS
SHOULD PERSIST THROUGH MUCH OF THE NIGHT...HELPING TO KEEP
TEMPERATURES UP.
ON WEDNESDAY...THE NEXT SHORTWAVE OF FOCUS DROPPING OUT OF SOUTH
CENTRAL CANADA WILL PROVIDE A PERIOD OF DPVA ACROSS THE FORECAST
AREA...ALONG WITH GIVING THE COLD FRONT OVER FAR WESTERN MN A BIGGER
PUSH. THE BIG QUESTIONS ARE BOTH FRONTAL TIMING AND HOW WARM CAN WE
GET PRIOR TO FRONTAL ARRIVAL. ALTHOUGH THERE IS NOW LESS CONCERN
FOR LOW CEILING STRATUS OVER ABOUT THE NORTHWEST 2/3 OF THE FORECAST
AREA...ISENTROPIC LIFT FIELDS SUGGEST A GOOD AMOUNT OF MID/HIGH
CLOUDS WILL OVERSPREAD THE AREA AHEAD OF THE SHORTWAVE AND COLD
FRONT. THE 30.12Z NAM EVEN DEVELOPS SOME LIGHT PRECIPITATION OUT OF
THESE CLOUDS NORTH OF I-90. MAIN COLD FRONTAL TIMING STILL LOOKS TO
BE DURING THE AFTERNOON WHICH IS GOOD...BUT THE AFOREMENTIONED
CLOUDS MAY LIMIT HEATING AND THUS BOTH CAPE AND CONVECTIVE
DEVELOPMENT ON THE FRONT. MODEL CONSENSUS IS TO GET HIGH
TEMPERATURES PRIOR TO FRONTAL ARRIVAL UP INTO THE MID 70S TO AROUND
80...WHICH RESULTS IN ABOUT 500-1000 J/KG OF TALL...THIN CAPE. THE
SKINNY NATURE OF THE CAPE WILL HELP MINIMIZE THE SEVERE WEATHER
POTENTIAL DESPITE FAVORABLE SHEAR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 215 PM CDT TUE JUL 30 2013
SYNOPTIC OVERVIEW...
30.12Z ECMWF/GFS/CANADIAN ALL SUGGEST A REX BLOCK STAYING MOSTLY IN
PLACE OVER WESTERN CANADA INTO THE GULF OF ALASKA...ALONG WITH
TROUGHING OVER SOUTHEAST CANADA INTO THE GREAT LAKES
REGION...THROUGH THE LONG TERM PERIOD. THIS MEANS THE FORECAST AREA
WILL STAY IN COOL...NORTHWEST FLOW WITH SHORTWAVES COMING THROUGH
THAT CAN BE HARD TO TIME. WHETHER OR NOT THESE SHORTWAVES PRODUCE
PRECIPITATION WILL DEPEND ON MOISTURE AVAILABILITY.
WEDNESDAY NIGHT THROUGH FRIDAY...
IN THE WAKE OF WEDNESDAYS COLD FRONTAL PASSAGE...THE 30.12Z NAM
BRINGS SOME PRECIP THROUGH THE SOUTHWESTERN HALF OF THE FORECAST
AREA WEDNESDAY NIGHT. THIS IS A RESULT OF SOME WEAK 305K ISENTROPIC
LIFT AHEAD OF A WEAK SHORTWAVE TRAVERSING IOWA...AS WELL AS BEING IN
THE LEFT EXIT REGION OF A 100 KT JET STREAK. ALL OTHER AVAILABLE
GUIDANCE IS DRY...CONSISTENT TOO WITH THE PREVIOUS FORECAST.
THEREFORE...HAVE KEPT A DRY FORECAST GOING. MODELS HAVE TRENDED
DRIER ON THURSDAY WITH ANY CONVECTIVE FORCING WELL OFF TO OUR NORTH
OR SOUTHWEST. ADDITIONALLY...IT APPEARS THERE SHOULD BE A SURGE OF
DRY AIR ON THURSDAY TO HELP MIX DEWPOINTS DOWN...ALSO FAVORING A
DRIER FORECAST. THURSDAY NIGHT INTO FRIDAY MAY STAND TO HAVE THE
BEST CHANCE FOR PRECIPITATION IN THIS NORTHWEST FLOW...IF YOU
BELIEVE THE NAM. MODELS ARE IN GOOD AGREEMENT DROPPING A SHORTWAVE
THROUGH NORTHERN WI FRIDAY MORNING. THE NAM IS MOST ROBUST IN
GENERATING BOTH LIFT AND QPF FROM THIS SHORTWAVE. HOWEVER...THE
GFS/ECMWF/CANADIAN ARE ALL MUCH DRIER AND SOME EVEN SUGGEST A DRY
FORECAST. THEREFORE...CONFIDENCE IN THE NAM SCENARIO IS QUITE LOW.
DID MAINTAIN A 20 PERCENT CHANCE FOR LATE THURSDAY NIGHT ACROSS THE
FORECAST AREA...AS WELL AS SOUTH OF I-90 ON FRIDAY...IN THE EVENT
THE NAM IS RIGHT. WITH 850MB TEMP ANOMALIES HOVERING IN THAT 0.5-1
STANDARD DEVIATION BELOW NORMAL...TEMPERATURES SHOULD CONTINUE TO
RUN ABOUT 5F DEGREES BELOW NORMAL FOR HIGHS. GENERALLY FOLLOWED A
MODEL GUIDANCE CONSENSUS FOR BOTH HIGHS AND LOWS.
FRIDAY NIGHT THROUGH TUESDAY...
DESPITE A NORTHWEST FLOW DURING THE WEEKEND...CONFIDENCE OF HAVING
IT DRY IS INCREASING. THE REASON IS THAT MODELS HAVE BEEN
CONSISTENTLY SHOWING CANADIAN HIGH PRESSURE BUILDING INTO THE
FORECAST AREA IN THE WAKE OF THAT SHORTWAVE CROSSING NORTHERN WI
FRIDAY MORNING. GIVEN THE CANADIAN SOURCE REGION...THE WEEKEND DOES
LOOK COOL...BUT NOT NEARLY AS COLD AS LAST WEEKEND. 850MB TEMPS DROP
TO 10-12C ON SATURDAY AND 8-11C ON SUNDAY WHICH AT MOST ARE 1-1.5
STANDARD DEVIATIONS BELOW NORMAL. THESE TEMPS STILL SUPPORT HIGHS IN
THE 70S. THE BIGGER QUESTION WILL BE LOWS...WHICH HIGHLY DEPENDS ON
TIMING WHEN THE SURFACE HIGH BUILDS OVERHEAD FOR PRIME RADIATIONAL
COOLING CONDITIONS. LOWS IN THE TYPICAL COLDER SPOTS IN THE 40S ARE
CERTAINLY POSSIBLE.
HEADING INTO EARLY NEXT WEEK...THERE ARE SIGNS IN THE 30.12Z
ECMWF/GFS OF A MORE SIGNIFICANT SHORTWAVE DROPPING THROUGH THE
NORTHWEST FLOW...COMING THROUGH THE FORECAST AREA ON MONDAY. THIS IS
A BIT OF A CHANGE FOR THE ECMWF...BEGINNING TO LEAN MORE TOWARDS
WHAT THE PAST FEW GFS RUNS HAVE SUGGESTED. IN ANY EVENT...CHANCES OF
SHOWERS AND THUNDERSTORMS ARE REQUIRED FOR SUNDAY NIGHT AND MONDAY
TO ACCOUNT FOR THE SHORTWAVE AND ASSOCIATED FORCING. FOR MONDAY
NIGHT AND TUESDAY...CONTINUITY AND MODEL CONSENSUS SUGGESTS HOLDING
ONTO 20-30 PERCENT CHANCES DURING THIS TIME PERIOD. THESE CHANCES
ARE ASSOCIATED WITH THE AFOREMENTIONED SHORTWAVE. HOWEVER...NEW
30.12Z GUIDANCE...PARTICULARLY THE ECMWF...SUGGESTING THAT A DRIER
FORECAST MAY BE MORE CORRECT. GIVEN THE UNCERTAINTY BEING IN
NORTHWEST FLOW AND HOW FAR OUT TUESDAY IS IN THE FORECAST...HAVE
LEFT THE CHANCES ALONE FOR NOW. 850MB TEMPS REMAIN BELOW
NORMAL...BETWEEN 10-12C...KEEPING HIGHS IN THE 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1146 PM CDT TUE JUL 30 2013
AN AREA OF CLEARING HAS DEVELOPED THIS EVENING ACROSS WESTERN AND
SOUTHERN MINNESOTA AND IS MAKING STEADY EASTWARD PROGRESS. LOOKS
LIKE IT SHOULD BE INTO KRST BY TAF ISSUANCE TIME AND THEN THE
QUESTION BECOMES WHETHER THIS WILL ALLOW FOG AND LOW CLOUDS TO
FORM OVERNIGHT WITH GOOD RADIATIONAL COOLING CONDITIONS. ALREADY
SEEING A FEW LOCATIONS WITH MVFR FOG WHERE IT HAS BEEN CLEAR FOR A
COUPLE OF HOURS...SO THE POTENTIAL IS THERE FOR THIS TO OCCUR.
THUS WILL LEAVE IN THE POSSIBILITY OF IFR CONDITIONS OVERNIGHT AT
KRST. NOT AS CLEAR CUT FOR KLSE WHETHER THE CLEARING WILL ARRIVE
IN TIME WITH ENOUGH HOURS OF COOLING LEFT IN THE NIGHT FOR THE FOG
TO DEVELOP. BUT BEFORE THAT CAN HAPPEN...A SMALL AREA OF MVFR
CLOUDS NEEDS TO MOVE THROUGH FIRST. WILL SHOW THESE COMING IN
AROUND 08Z AND WHILE IT MAY SCATTERED OUT FOR A WHILE...IT THEN
HAS THE POSSIBILITY OF FOGGING RIGHT BACK UP. WILL SHOW THE MVFR
CLOUDS HOLDING ON WITH THE POSSIBILITY OF IFR CONDITIONS AS WELL.
THE WIND SHIFT TO THE WEST AHEAD OF THE MAIN FRONT WILL OCCUR AT
BOTH SITES BETWEEN 12 AND 15Z TO END ANY MVFR/IFR CONDITIONS THAT
DEVELOP OVERNIGHT. THE 31.00Z NAM HAS COME IN WITH EVEN LESS
FORCING AND CONVERGENCE ALONG THE FRONT AND SHOWS VERY LITTLE RAIN
OCCURRING. BASED ON THIS HAVE DROPPED THE VCSH OUT OF THE FORECAST
AND WILL JUST SHOW SOME SCATTERED CUMULUS AS THE FRONT COMES
THROUGH WITH HIGH VFR CEILINGS THAT WILL THEN SCATTER OUT DURING
THE EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1132 PM MDT THU AUG 1 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
CURRENTLY...SHORTWAVE TROUGH AND UPPER VORT MAX ARE CURRENTLY
EJECTING EASTWARD ACROSS COLORADO...WHILE A SECONDARY WAVE MOVES
NORTHWARD OUT OF NEW MEXICO INTO SOUTHERN COLORADO. RADAR INDICATES
WIDESPREAD CONVECTION OVER THE MOUNTAIN AREAS AND SPREADING EAST
INTO THE I-25 CORRIDOR. TEMPERATURES HAVE BEEN WARM WITH UPPER 80S
TO LOWER 90S FOR THE PLAINS.
THROUGH TONIGHT...MODELS HAVING A HARD TIME WITH THIS UPPER LEVEL
DISTURBANCE AND THE AMOUNT OF CONVECTION FIRING ACROSS THE REGION.
THE LATEST RAP AND HRRR SEEM TO HAVE A BETTER HANDLE WITH THE LATEST
RUNS WITH CONVECTION SPREADING EAST ACROSS THE PLAINS THROUGH THE
EVENING HOURS. DEW POINTS IN THE UPPER 50S AND PWAT VALUES
APPROACHING AN INCH HAVE LED TO LOCALLY HEAVY RAINFALL WITH THESE
THUNDERSTORMS. OF CONCERN ARE AREA BURN SCARS...WHICH COULD SEE
LOCALIZED FLASH FLOODING WITH ANY HEAVY CELLS THAT MOVE OVER THEM.
WHILE THE WEST FORK COMPLEX HAS ONLY SEEN LIGHT PRECIP SO FAR
TODAY...THE UPPER DISTURBANCE MOVING NORTH OUT OF NEW MEXICO SHOULD
PROVIDE ENHANCED LIFT AND CONTINUED THREAT FOR HEAVY RAINFALL
THROUGH THIS EVENING. NOT MUCH OF A SEVERE WEATHER THREAT ACROSS
THE PLAINS THIS EVENING. THERE COULD BE SOME DIME TO PENNY SIZE
HAIL WITH THE STRONGEST CELLS...ESPECIALLY SOUTH OF HIGHWAY 50
THROUGH ABOUT 9PM TONIGHT. EXPECT MOST ACTIVITY TO SHIFT EAST WITH
THE UPPER WAVE AFTER MIDNIGHT WITH SHOWER AND THUNDERSTORM ACTIVITY
COMING TO AN END THROUGH FRIDAY MORNING. THE EXCEPTION WILL BE THE
SAN JUAN RANGE WHERE THE EJECTING UPPER DISTURBANCE WILL LIKELY KEEP
THUNDERSTORMS GOING INTO FRIDAY MORNING.
FRIDAY...THE UPPER LEVEL DISTURBANCE OUT OF NEW MEXICO WILL TRACK
INTO SOUTHWEST KANSAS BY FRIDAY AFTERNOON WHILE A WEAK BOUNDARY
SHIFTS SOUTH INTO THE PLAINS. DRIER AIR AND SUBSIDENCE BEHIND THE
DEPARTING WAVE SHOULD LIMIT THUNDERSTORM ACTIVITY TO THE MOUNTAIN
AREAS...AND NEAR THE NEW MEXICO BORDER. THE MAIN THREATS WILL
CONTINUE TO BE LOCALIZED HEAVY RAINFALL AND LIGHTNING. GIVEN THE
DECREASE IN MOISTURE...THE FLASH FLOOD RISK WILL LIKELY BE MINIMAL
OVER THE WEST FORK COMPLEX...BUT ANY CELLS THAT DO MOVE OVER THE
BURN SCAR COULD PRODUCE A QUICK BURST OF RAINFALL. TEMPERATURES
WILL REMAIN WARM WITH AFTERNOON HIGHS IN THE MID TO UPPER 90S ACROSS
THE LOWER ELEVATIONS. MOZLEY
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
...SUMMER MONSOON WILL STICK AROUND FOR A WHILE...
ALL IN ALL...GOOD NEW IN THE WEATHER DEPARTMENT...THE SUMMER MONSOON
LOOKS ALIVE AND WELL THROUGH AT LEAST NEXT WEEK. THERE WILL BE
WETTER DAYS AND DRIER DAYS...BUT THE MONSOON PLUME WILL GENERALLY
REMAIN OVER COLORADO. NOT EVERYONE WILL GET RAIN EVERYDAY...SUMMER
CONVECTION IS PRETTY MUCH ALWAYS HIT OR MISS. BUT...OVER
TIME...MOST WILL GET THERE SHARE OF THE MONSOON...MAYBE ONLY 1 DAY
IN THE NEXT 7...MAYBE 2 DAYS...MAYBE EVEN 3 DAYS OR MORE. BUT...THE
SHOWERS WILL BE AROUND...AND THE HUMIDITIES WILL BE UP...ALL GOOD
FOR COLORADO. WELL...MAYBE NOT SO GOOD FOR THE BURN SCAR AREAS...OF
COURSE.
FRIDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR ISOLATED TO
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE
AREA...ESPECIALLY MOUNTAINS AND RIDGES.
SATURDAY CONTINUES TO LOOK LIKE A GOOD CHANCE OF SHOWERS OVER MOST
OF THE AREA...BUT ESPECIALLY FOR THE EASTERN MOUNTAINS AND PLAINS.
A SIGNIFICANT SURFACE BOUNDARY IS STILL POISED TO MOVE THROUGH THE
EASTERN PLAINS THIS DAY AND INTERACT WITH THE MONSOON PLUME...TO
PRODUCE MORE WIDESPREAD PRECIPITATION THAN TYPICAL. WITH THE
GREATER NUMBER OF SHOWERS AROUND...AND THE GREATER LIFTING PROVIDED
BY THE SURFACE BOUNDARY...THIS WILL INCREASE THE HEAVY RAIN
POTENTIAL AT ANY ONE LOCATION THIS DAY. SO...THE BURN SCAR FLASH
FLOOD THREAT WILL BE UP.
SUNDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR
CONVECTION...ESPECIALLY MOUNTAINS AND RIDGES AGAIN.
LATER MONDAY THROUGH THE REMAINDER OF THE WEEK CONTINUES TO LOOK
INTERESTING WITH THE CHANCES FOR AFTERNOON AND NIGHTLY SHOWERS AND
THUNDERSTORMS GOING UP THROUGH THE PERIOD. STARTING MONDAY
NIGHT...A SERIES OF SURFACE BOUNDARIES WILL START TO MOVE THROUGH
THE EASTERN HALF OF THE FORECAST AREA. THESE BOUNDARIES WILL BE
TIED TO A SLOWLY MOVING BROAD UPPER LEVEL TROUGH DROPPING SOUTHWARD
THROUGH THE NORTHERN PLAINS DURING THE PERIOD. THE JET STREAM ON
THE SOUTH SIDE OF THIS TROUGH WILL TEND TO SEND SURFACE BOUNDARIES
SOUTH THROUGH THE PLAINS ON A REGULAR BASIS...THUS...INCREASING THE
AMOUNT OF LOW LEVEL UPSLOPE FLOW OVER THE EAST. THE INCREASED
LIFTING OF THE AIR ASSOCIATED WITH THE UPSLOPE COMBINED WITH A
STRONG MONSOON PRESENCE WILL SET THE STAGE FOR REPEATED ROUNDS OF
SHOWERS...HEAVY AT TIMES...THROUGH THE PERIOD. IF CURRENT FORECASTS
VERIFY...THE BURN SCAR AREAS WILL LIKELY NEED TO BE ON HIGH ALERT
MOST OF NEXT WEEK. LW
&&
.AVIATION...ISSUED AT 1130 PM MDT THU AUG 1 2013
VFR CONDITIONS ARE ANTICIPATED OVER THE KCOS AND KPUB TAF SITES
THROUGH TONIGHT. FOR THE KALS TAF SITE...AREAS OF LOW CLOUDS AND
FOG WILL BE POSSIBLE...ESPECIALLY AFTER MIDNIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1127 PM MDT THU AUG 1 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
CURRENTLY...SHORTWAVE TROUGH AND UPPER VORT MAX ARE CURRENTLY
EJECTING EASTWARD ACROSS COLORADO...WHILE A SECONDARY WAVE MOVES
NORTHWARD OUT OF NEW MEXICO INTO SOUTHERN COLORADO. RADAR INDICATES
WIDESPREAD CONVECTION OVER THE MOUNTAIN AREAS AND SPREADING EAST
INTO THE I-25 CORRIDOR. TEMPERATURES HAVE BEEN WARM WITH UPPER 80S
TO LOWER 90S FOR THE PLAINS.
THROUGH TONIGHT...MODELS HAVING A HARD TIME WITH THIS UPPER LEVEL
DISTURBANCE AND THE AMOUNT OF CONVECTION FIRING ACROSS THE REGION.
THE LATEST RAP AND HRRR SEEM TO HAVE A BETTER HANDLE WITH THE LATEST
RUNS WITH CONVECTION SPREADING EAST ACROSS THE PLAINS THROUGH THE
EVENING HOURS. DEW POINTS IN THE UPPER 50S AND PWAT VALUES
APPROACHING AN INCH HAVE LED TO LOCALLY HEAVY RAINFALL WITH THESE
THUNDERSTORMS. OF CONCERN ARE AREA BURN SCARS...WHICH COULD SEE
LOCALIZED FLASH FLOODING WITH ANY HEAVY CELLS THAT MOVE OVER THEM.
WHILE THE WEST FORK COMPLEX HAS ONLY SEEN LIGHT PRECIP SO FAR
TODAY...THE UPPER DISTURBANCE MOVING NORTH OUT OF NEW MEXICO SHOULD
PROVIDE ENHANCED LIFT AND CONTINUED THREAT FOR HEAVY RAINFALL
THROUGH THIS EVENING. NOT MUCH OF A SEVERE WEATHER THREAT ACROSS
THE PLAINS THIS EVENING. THERE COULD BE SOME DIME TO PENNY SIZE
HAIL WITH THE STRONGEST CELLS...ESPECIALLY SOUTH OF HIGHWAY 50
THROUGH ABOUT 9PM TONIGHT. EXPECT MOST ACTIVITY TO SHIFT EAST WITH
THE UPPER WAVE AFTER MIDNIGHT WITH SHOWER AND THUNDERSTORM ACTIVITY
COMING TO AN END THROUGH FRIDAY MORNING. THE EXCEPTION WILL BE THE
SAN JUAN RANGE WHERE THE EJECTING UPPER DISTURBANCE WILL LIKELY KEEP
THUNDERSTORMS GOING INTO FRIDAY MORNING.
FRIDAY...THE UPPER LEVEL DISTURBANCE OUT OF NEW MEXICO WILL TRACK
INTO SOUTHWEST KANSAS BY FRIDAY AFTERNOON WHILE A WEAK BOUNDARY
SHIFTS SOUTH INTO THE PLAINS. DRIER AIR AND SUBSIDENCE BEHIND THE
DEPARTING WAVE SHOULD LIMIT THUNDERSTORM ACTIVITY TO THE MOUNTAIN
AREAS...AND NEAR THE NEW MEXICO BORDER. THE MAIN THREATS WILL
CONTINUE TO BE LOCALIZED HEAVY RAINFALL AND LIGHTNING. GIVEN THE
DECREASE IN MOISTURE...THE FLASH FLOOD RISK WILL LIKELY BE MINIMAL
OVER THE WEST FORK COMPLEX...BUT ANY CELLS THAT DO MOVE OVER THE
BURN SCAR COULD PRODUCE A QUICK BURST OF RAINFALL. TEMPERATURES
WILL REMAIN WARM WITH AFTERNOON HIGHS IN THE MID TO UPPER 90S ACROSS
THE LOWER ELEVATIONS. MOZLEY
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
...SUMMER MONSOON WILL STICK AROUND FOR A WHILE...
ALL IN ALL...GOOD NEW IN THE WEATHER DEPARTMENT...THE SUMMER MONSOON
LOOKS ALIVE AND WELL THROUGH AT LEAST NEXT WEEK. THERE WILL BE
WETTER DAYS AND DRIER DAYS...BUT THE MONSOON PLUME WILL GENERALLY
REMAIN OVER COLORADO. NOT EVERYONE WILL GET RAIN EVERYDAY...SUMMER
CONVECTION IS PRETTY MUCH ALWAYS HIT OR MISS. BUT...OVER
TIME...MOST WILL GET THERE SHARE OF THE MONSOON...MAYBE ONLY 1 DAY
IN THE NEXT 7...MAYBE 2 DAYS...MAYBE EVEN 3 DAYS OR MORE. BUT...THE
SHOWERS WILL BE AROUND...AND THE HUMIDITIES WILL BE UP...ALL GOOD
FOR COLORADO. WELL...MAYBE NOT SO GOOD FOR THE BURN SCAR AREAS...OF
COURSE.
FRIDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR ISOLATED TO
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE
AREA...ESPECIALLY MOUNTAINS AND RIDGES.
SATURDAY CONTINUES TO LOOK LIKE A GOOD CHANCE OF SHOWERS OVER MOST
OF THE AREA...BUT ESPECIALLY FOR THE EASTERN MOUNTAINS AND PLAINS.
A SIGNIFICANT SURFACE BOUNDARY IS STILL POISED TO MOVE THROUGH THE
EASTERN PLAINS THIS DAY AND INTERACT WITH THE MONSOON PLUME...TO
PRODUCE MORE WIDESPREAD PRECIPITATION THAN TYPICAL. WITH THE
GREATER NUMBER OF SHOWERS AROUND...AND THE GREATER LIFTING PROVIDED
BY THE SURFACE BOUNDARY...THIS WILL INCREASE THE HEAVY RAIN
POTENTIAL AT ANY ONE LOCATION THIS DAY. SO...THE BURN SCAR FLASH
FLOOD THREAT WILL BE UP.
SUNDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR
CONVECTION...ESPECIALLY MOUNTAINS AND RIDGES AGAIN.
LATER MONDAY THROUGH THE REMAINDER OF THE WEEK CONTINUES TO LOOK
INTERESTING WITH THE CHANCES FOR AFTERNOON AND NIGHTLY SHOWERS AND
THUNDERSTORMS GOING UP THROUGH THE PERIOD. STARTING MONDAY
NIGHT...A SERIES OF SURFACE BOUNDARIES WILL START TO MOVE THROUGH
THE EASTERN HALF OF THE FORECAST AREA. THESE BOUNDARIES WILL BE
TIED TO A SLOWLY MOVING BROAD UPPER LEVEL TROUGH DROPPING SOUTHWARD
THROUGH THE NORTHERN PLAINS DURING THE PERIOD. THE JET STREAM ON
THE SOUTH SIDE OF THIS TROUGH WILL TEND TO SEND SURFACE BOUNDARIES
SOUTH THROUGH THE PLAINS ON A REGULAR BASIS...THUS...INCREASING THE
AMOUNT OF LOW LEVEL UPSLOPE FLOW OVER THE EAST. THE INCREASED
LIFTING OF THE AIR ASSOCIATED WITH THE UPSLOPE COMBINED WITH A
STRONG MONSOON PRESENCE WILL SET THE STAGE FOR REPEATED ROUNDS OF
SHOWERS...HEAVY AT TIMES...THROUGH THE PERIOD. IF CURRENT FORECASTS
VERIFY...THE BURN SCAR AREAS WILL LIKELY NEED TO BE ON HIGH ALERT
MOST OF NEXT WEEK. LW
&&
.AVIATION...ISSUED AT 1125 PM MDT THU AUG 1 2013
VFR CONDITIONS ARE ANTICIPATE OVER THE KALS...KCOS AND KPUB
TAF SITES THROUGH TONIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
148 AM EDT FRI AUG 2 2013
.AVIATION...
VERY TRICKY TAF FORECAST FOR TODAY. A TROUGH OF LOW PRESSURE WAS
SLOWLY DEVELOPING OVER THE ATLANTIC IN BETWEEN THE BAHAMAS AND
SOUTH FLORIDA. THIS FEATURE IS FORECAST TO TRACK VERY NEAR THE
COAST OR POSSIBLY EVEN OVER THE REGION LATER TODAY...AND THIS HAS
MAJOR IMPLICATIONS ON THE WIND DIRECTION/SPEED AS WELL AS RAINFALL
FOR THE EAST COAST TAF SITES.
EXPECT LIGHT WINDS TO CONTINUE THROUGH THE EARLY MORNING HOURS
TODAY...AND A FEW SHOWERS MAY MOVE TOWARDS SHORE AND AFFECT THE
EAST COAST TAF SITES. A WEAK EAST COAST SEA BREEZE MAY DEVELOP BY
LATE MORNING/EARLY AFTERNOON WITH SHOWERS AND STORMS NEAR THE TAF
SITES. THE TROUGH OF LOW PRESSURE OFF THE COAST MAY ALSO TRACK
CLOSER TO THE REGION...AND HEAVY RAIN/THUNDERSTORMS COULD AFFECT
SOME OF THE EAST COAST TERMINALS IN THE AFTERNOON. THE HIGHEST
PROBABILITY MAY BE TOWARDS KPBI. FOR KAPF...SHOWERS AND STORMS MAY
REMAIN MAINLY INLAND OF THE TAF SITE THIS AFTERNOON...BUT KEPT
VCSH IN THE TAF. LIGHT WINDS ARE EXPECTED AGAIN TONIGHT ACROSS
THE REGION.
&&
.PREV DISCUSSION... /ISSUED 811 PM EDT THU AUG 1 2013/
UPDATE...
SHOWERS AND THUNDERSTORMS HAVE BECOME MOSTLY CONFINED TO THE WEST
COAST AND ADJACENT WATERS. THERE ARE SOME ISOLATED SHOWERS OVER
THE ATLANTIC WATERS AS WELL. THE HRRR CONTINUES TO SHOW ISOLATED
TO SCATTERED ACTIVITY THROUGH THE OVERNIGHT HOURS OVER THE
ATLANTIC WATERS. IT ALSO SHOWS THE SHOWERS, AND OR ANY
THUNDERSTORMS, WEAKENING AS THEY MOVE ONSHORE. POPS HAVE BEEN
ADJUSTED SOMEWHAT TO REFLECT THIS PATTERN.
AVIATION...
HIGHER THAN USUAL DEGREE OF UNCERTAINTY IN THE 0Z TAF
ISSUANCES...AS THE FORECAST WILL BE IMPACTED BY THE EVOLUTION OF
THE REMNANTS OF TROPICAL STORM DORIAN. THESE REMNANTS BECAME MORE
CONCENTRATED THIS AFTERNOON...THEN DIMINISHED THIS EVENING OVER
THE NORTHWEST BAHAMAS. GUIDANCE HAS THE SYSTEM CONTINUING
NORTHWEST OVERNIGHT...GRADUALLY TURNING NORTHWARD FRIDAY. THE NAM
TAKES CONVECTION ASSOCIATED WITH THE REMNANTS ONSHORE...WHEREAS
OTHER MODELS KEEP THE MOST ROBUST PRECIPITATION OVER ATLANTIC
WATERS...WITH ONLY SCATTERED ACTIVITY ON LAND. EVEN FOR
TONIGHT...SHOWERS IN THE WESTERN-MOST BAHAMAS ARE MOVING TOWARD
SOUTH FLORIDA...AND GUIDANCE OFFERS LITTLE CONSENSUS ON WHETHER
THEY WILL HOLD TOGETHER.
LATEST TAFS KEEP VCSH THROUGH THE OVERNIGHT AND INTO
TOMORROW...BUT DID NOT CALL FOR INCREASING ACTIVITY OR VCTS FOR
FRIDAY AFTERNOON...DUE TO THE AFOREMENTIONED CONFIDENCE ISSUES.
WINDS SHOULD GENERALLY BE SOUTH OF EAST...BUT IF DORIANS REMNANTS
ARE FAIRLY ORGANIZED...WINDS ARE LIKELY TO BACK TO THE NORTHEAST
ON FRIDAY. SPEEDS SHOULD BE LESS THAN 15 KTS REGARDLESS OF THEIR
DIRECTION...EXCEPT IN AN NEAR PRECIPITATION.
PREV DISCUSSION... /ISSUED 248 PM EDT THU AUG 1 2013/
.MAIN IMPACTS FROM BAHAMAS LOW PRESSURE SYSTEM EXPECTED TO REMAIN
MOSTLY OFFSHORE...
DISCUSSION...
LOW PRESSURE SYSTEM OVER THE BAHAMAS CONTAINING THE REMNANTS OF
DORIAN HAVE BECOME MORE CONCENTRATED TODAY AS IT MOVES NORTHWEST.
SOUTH FLORIDA APPEARS TO BE UNDER A REGION OF UPPER-LEVEL
SUBSIDENCE AND ASSOCIATED DRIER AIR WHICH IS LIMITING THE
DEVELOPMENT OF THE CONVECTION OVER THE PENINSULA SO FAR THIS
AFTERNOON. IN FACT, SATELLITE IMAGERY IS SHOWING SEVERAL ARC-
SHAPED CLOUD PATTERNS SPREADING WESTWARD OVER THE WATERS OFF THE SE
FLORIDA COAST FROM THE CLUSTER OF STORMS OVER THE BAHAMAS...A
USUAL SIGN OF SUBSIDENCE PREVENTING CONVECTION FROM GETTING
ORGANIZED OR VERY STRONG AS THESE SHOWERS APPROACH THE FLORIDA
COAST. FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING,
GREATEST COVERAGE OF SHOWERS/TSTMS WILL BE OVER THE INTERIOR IN
A TYPICAL EAST FLOW PATTERN
MODELS APPEAR TO HAVE A DECENT HANDLE ON THE LOW PRESSURE AREA AND
ARE REASONABLY CONSISTENT IN KEEPING THE BULK OF THE ASSOCIATED
WEATHER OFFSHORE TONIGHT AND FRIDAY. THE GFS IS THE ONLY MODEL
WHICH BRINGS THE LOW LEVEL CIRCULATION (850 MB) ONSHORE THE EAST
COAST LATE TONIGHT AND EARLY FRIDAY, WITH THE NAM AND ECMWF
KEEPING IT OFFSHORE OVER THE STRAITS. DUE TO THE UNCERTAINTY IN
THE LOCATION OF THE LOW LEVEL CIRCULATION AND HOW CLOSE IT MAY
COME TO THE EAST COAST, WILL INDICATE SCT TSTMS (30%) FOR EAST
COAST LATE TONIGHT DESPITE MODELS NOT BEING ENTHUSIASTIC ABOUT
PRECIPITATION COVERAGE. THE LOW IS EXPECTED TO MOVE NORTH NEAR OR
JUST OFF THE COAST FRIDAY ALONG THE WESTERN PERIPHERY OF THE
ATLANTIC SUBTROPICAL RIDGE. AS MENTIONED ABOVE, THIS WOULD KEEP
MOST OF THE ASSOCIATED SHOWERS/TSTMS/GUSTY WINDS OFFSHORE, BUT A
GENERAL INCREASE IN MOISTURE ACROSS SOUTH FLORIDA ALONG WITH THE
PRESENCE OF A LOW/MID LEVEL TROUGH WILL LEAD TO SCATTERED MAINLY
AFTERNOON TSTMS. VERY HEAVY RAINFALL AND MINOR FLOODING ARE THE
MAIN THREATS WITH THE STORMS ON FRIDAY DUE TO THE EXPECTED SLOW
STORM MOTION.
FOR THE WEEKEND...THE LOW PRESSURE IS FORECAST TO MOVE NORTH OF THE
AREA FRIDAY NIGHT, LEAVING BEHIND A BUILDING LOW/MID LEVEL RIDGE
OVER SOUTH FLORIDA. THE ORIENTATION OF THE RIDGE RIGHT OVER SOUTH
FLORIDA WILL LEAD TO LIGHT SW/W WINDS AND FOCUS SCATTERED AFTERNOON
TSTMS TO THE INTERIOR/LAKE OKEECHOBEE AND PALM BEACH COUNTY AREAS
ON SATURDAY, AND GENERALLY INTERIOR AND EAST ON SUNDAY. TEMPERATURES
WILL ALSO BE ON THE RISE, PARTICULARLY THE DAYTIME HIGHS INTERIOR
AND EAST. SUNDAY COULD SEE HIGHS IN THE LOW/MID 90S EVEN INTO
PARTS OF THE EAST COAST METRO WITH MAXIMUM HEAT INDEX VALUES
100-105F JUST ABOUT EVERYWHERE, WITH ISOLATED POCKETS OF 105-109F
POSSIBLE IN THE EVERGLADES.
THE WEEKEND PATTERN LOOKS TO REMAIN IN PLACE INTO EARLY NEXT WEEK,
WITH HOT TEMPERATURES AND AFTERNOON TSTMS FOCUSING INTERIOR AND
EAST. BY WEDNESDAY, MODELS SHOW SOME DIFFERENCES WITH THE GFS
SHOWING EASTERLY FLOW RETURNING AND THE ECMWF SHOWING A LINGERING
LOW/MID LEVEL LOW OVER THE EASTERN GULF OF MEXICO. THE ECMWF
SCENARIO IS WETTER/STORMIER THAN THE GFS FOR MIDDLE OF NEXT WEEK,
BUT STILL PLENTY OF TIME TO EVALUATE TRENDS.
AVIATION...
FOR THIS AFTERNOON...BANDS OF SHOWERS WILL CONTINUE TO MOVE WESTWARD
ACROSS THE ATLANTIC WATERS AND AFFECT THE EAST COAST TAF SITES FROM
TIME TO TIME BUT MAINLY VFR CONDITIONS ARE EXPECTED TO
PREVAIL...ALTHOUGH AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT. FOR
TERMINAL KAPF...VCTS IS ASSIGNED BY 19Z WITH PERIODS OF SUB-VFR
CONDITIONS POSSIBLE AND VERY BRIEF PERIODS OF IFR CONDITIONS
POSSIBLE WITH THE OCCURRENCE OF SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN PENINSULA THIS AFTERNOON AND EARLY EVENING.
FOR TONIGHT INTO FRIDAY...THE COMBINATION OF THE REMNANTS OF DORIAN
AND AN UPPER LOW MOVING IN TANDEM WITH IT HAS CREATED A SURFACE
TROUGH AND AN AREA OF CLOUDINESS ACROSS THE CENTRAL AND NORTHWEST
BAHAMAS...WITH SHOWERS AND THUNDERSTORMS IN THESE AREAS. ALTHOUGH
THE LOW PRESSURE AND ASSOCIATED CONVECTION IS FORECAST TO REMAIN
TO THE EAST OF SOUTH FLORIDA THROUGH THE TAF PERIOD...BANDS OF
SHOWERS WILL CONTINUE TO AFFECT THE EAST COAST TAF SITES TONIGHT
INTO FRIDAY WITH ALL EAST COAST TERMINALS ASSIGNED VCSH THROUGH
THIS PERIOD.
MARINE...
MODERATE EASTERLY WINDS TODAY WILL DECREASE TONIGHT AND BECOME
S/SW AS THE LOW PRESSURE AREA MOVES NEAR THE LOCAL ATLANTIC
WATERS. UNLESS THE SYSTEM DEVELOP, WHICH IS A LOW POSSIBILITY AT
THIS TIME, WINDS WILL REMAIN LIGHT WITH THE PRIMARY CONCERN BEING
GUSTY WINDS IN AND NEAR THE SHOWERS/TSTMS OVER THE ATLANTIC. THE
LIGHT S/SW FLOW WILL CONTINUE THROUGH THE UPCOMING WEEKEND AND
LIKELY INTO EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 78 91 79 / 50 30 40 20
FORT LAUDERDALE 89 77 91 78 / 50 30 30 20
MIAMI 90 77 91 78 / 50 30 30 20
NAPLES 90 76 91 76 / 40 20 30 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1137 PM CDT THU AUG 1 2013
.UPDATE...
ISSUED AT 947 PM CDT THU AUG 1 2013
AREA RADARS CONTINUE TO SHOW SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER NE IA...INTO SW WI AND NW IL...MOVING SOUTHEAST
AND GENERALLY IN DISSIPATION MODE. A LARGE COMPLEX OF
THUNDERSTORMS IS CONCENTRATED OVER THE STATE OF NEB TONIGHT WHERE
00Z UPPER AIR ANALYSIS SHOWED FEED OF 14 PLUS C DEWPOINTS AT 850
MB INTERACTING WITH A SHORTWAVE IN THE NW FLOW ALOFT. THIS MCS IS
MOVING SOUTHEAST DOWN THE BACK SIDE OF THE UPPER RIDGE TOWARD KS
AND NW MO. LATEST HIGH RES MODELS CONTINUE TO SUGGEST THE
CONVECTION TO OUR N WILL HOLD TOGETHER AND MOVE THROUGH THE
FORECAST AREA OVERNIGHT...WHICH BASED ON THE PAST FEW
RUNS...APPEARS OVERLY AGGRESSIVE. WILL MORE LIKELY SEE THESE
SHOWERS AND THUNDERSTORMS MOVE INTO FAR EAST CENTRAL IA AND NW IL
AND CONTINUE DISSIPATE OVER THE NEXT COUPLE HOURS AS THE MUCAPE
VALUES CONTINUE TO WANE. BASED ON 00Z ANALYSIS AND A LOOK AT THE
NEW 00Z WRF...THERE APPEARS TO BE LITTLE SUPPORT FOR ADDITIONAL
THUNDERSTORMS OVER THE NEXT FEW HOURS...UNTIL THE SUPPORT OVER NEB
AND WEAK 850 MOISTURE CONVERGENCE REFOCUSES ON S CENTRAL IA AND
THEN SE IA TOWARD MORNING. NEITHER THIS MODEL...OR THE BULK OF
THE OPERATIONAL MODELS FROM THE PREVIOUS RUN HAD A GOOD HANDLE ON
THE PLACEMENT OF CONVECTION IN THE PLAINS THIS EVENING.
HAVE THUS MADE SIGNIFICANT REVISIONS TO THE FORECAST TO LOWER POPS
OVER ESPECIALLY THE NORTH FOR OVERNIGHT INTO FRIDAY MORNING.
&&
.SYNOPSIS...
ISSUED AT 326 PM CDT THU AUG 1 2013
12Z UA ANALYSIS HAS A WEAK 850MB COLD FRONT FROM LAKE HURON TO THE
MN/IA BORDER. A RESPECTABLE SHORTWAVE RAN FROM THE DAKOTAS INTO
WESTERN NEBRASKA WHILE A MOISTURE GRADIENT RAN FROM WESTERN MISSOURI
INTO NEBRASKA. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOW
CONVECTION ASSOCIATED WITH THE DAKOTAS SHORT WAVE AND NEW CONVECTION
ON THE NORTH EDGE OF THE MOISTURE GRADIENT ACROSS NEBRASKA.
18Z SFC ANALYSIS HAS WEAK LOWS IN COLORADO AND SOUTHEAST WYOMING AND
ANOTHER IN WESTERN MINNESOTA. WEAK BOUNDARIES CONNECTED THE
MINNESOTA LOW TO THE LOW IN WYOMING WHILE SEVERAL WEAK TROFS WERE
ACROSS THE GREAT LAKES. A SFC MOISTURE BOUNDARY RAN FROM NEBRASKA
INTO NORTHWEST MISSOURI. DEW POINTS WERE IN THE 50S ACROSS THE GREAT
LAKES AND UPPER MIDWEST WITH 60S ACROSS MUCH OF THE PLAINS AND OHIO
VALLEY. DEW POINTS IN THE 70S WERE ACROSS THE SOUTHERN PLAINS AND
DEEP SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 326 PM CDT THU AUG 1 2013
DEEP MIXING THIS AFTERNOON HAS DROPPED THE DEW POINTS INTO THE LOW
TO MID 50S ACROSS WISCONSIN...NORTHERN ILLINOIS...AND NORTHEAST
IOWA. THE DEEP MIXING COMBINED WITH SUBSIDENCE HAS PREVENTED ANY
DIURNAL CLOUD DEVELOPMENT.
BASED ON SATELLITE AND RAP TRENDS USING THE MCS/LIFT TOOLS...THE
AGITATED CU DEVELOPMENT ALONG THE MN/IA BORDER SHOULD SLOWLY EVOLVE
INTO ISOLATED TO SCATTERED SHOWERS AND POSSIBLY A COUPLE OF
THUNDERSTORMS ACROSS THE NORTHERN CWFA DURING THE EVENING HOURS. THE
MORE SUBSTANTIAL STORM DEVELOPMENT ACROSS NEBRASKA MAY INDUCE SOME
ISOLATED SHOWERS OR A THUNDERSTORM ACROSS THE SOUTHERN HALF OF THE
CWFA BY MID TO LATE EVENING. STARTING AROUND MIDNIGHT THERE MAY BE A
LULL IN ACTIVITY FOR SEVERAL HOURS.
THE MCS TOOL IS REASONABLY CONSISTENT INDICATING A RESPECTABLE MCS
WILL DEVELOP THIS EVENING ACROSS EASTERN NEBRASKA/WESTERN IOWA AND
MOVE EAST SOUTHEAST OVERNIGHT ARRIVING IN THE SOUTHERN TWO THIRDS OF
THE CWFA PRIOR TO SUNRISE. CORFIDI VECTORS DO NOT SUGGEST ANY BACK
BUILDING BUT THE BACKWARD PROPAGATING VECTORS DO BECOME
PERPENDICULAR ACROSS THE SOUTHERN HALF OF THE CWFA SUGGESTING A WEAK
THREAT OF STORMS MOVING OVER THE SAME AREA.
THE DRIER AIR ACROSS THE AREA MAY RESULT IN SOME SMALL HAIL IN THE
STRONGER STORMS BEFORE THE ATMOSPHERE SATURATES LATE TONIGHT.
ON FRIDAY THE NOCTURNAL MCS WILL BE OVER THE CWFA DURING THE MORNING
HOURS AND WILL SLOWLY DECAY INTO MORE SHOWERS THAN THUNDERSTORMS BY
LATE MORNING. BOUNDARIES LEFT OVER FROM THIS MCS WILL THEN PROVIDE
THE FOCUS FOR NEW DEVELOPMENT DURING THE AFTERNOON. THE MCS TOOL
WHEN APPLIED TO SOME MODELS SUGGESTS THE POTENTIAL FOR ANOTHER MCS
AFFECTING THE AREA LATE FRIDAY AFTERNOON AND INTO FRIDAY NIGHT.
TEMPERATURES ON FRIDAY MAY REMAIN IN THE 60S FOR THE MORNING UNTIL
THE RAIN ENDS AND THEN CLIMBING INTO THE 70S DURING THE
AFTERNOON. ..08..
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 326 PM CDT THU AUG 1 2013
FORECAST FOCUS IS ON PERIODS FOR PRECIPITATION CHANCES AND BELOW
NORMAL TEMPERATURES THROUGH NEXT WEEK.
FRIDAY NIGHT AND SATURDAY...CHANCES FOR SHOWERS AND A FEW
THUNDERSTORMS CONTINUE FRIDAY EVENING AS UPPER SHORTWAVE ENERGY
WORKS ITS WAY ACROSS THE AREA. THE BETTER CHANCES LOOK TO BE ACROSS
THE SOUTHERN FORECAST SECTIONS...AND WILL DIMINISH SATURDAY MORNING
AS THE SHORTWAVE DEPARTS.
SUNDAY THROUGH THURSDAY...SEVERAL SHORTWAVES ARE FORECAST TO MOVE
THROUGH THE CONTINUED NORTHWEST FLOW AND BRING A COUPLE
OPPORTUNITIES FOR SHOWERS AND STORMS. AS CAN BE EXPECTED...FORECAST
MODELS ARE SHOWING QUITE A BIT OF VARIATION IN TIMING AND PLACEMENT
OF THESE SMALLER SCALE FEATURES. THEREFORE CONFIDENCE IN WHICH DAYS
HOLD THE BEST CHANCE FOR PRECIPITATION IS LOW. SEASONABLY COOL
TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MIDDLE 70S TO LOWER 80S
RANGE...AND LOWS IN THE MIDDLE 50S TO LOWER 60S FOR MOST OF THE WEEK.
STOFLET
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1137 PM CDT THU AUG 1 2013
POTENTIAL FOR OVERNIGHT SHOWERS AND THUNDERSTORMS HAS GREATLY
DIMINISHED AND THIS IS REFLECTED IN THE LATEST FORECASTS. AN UPPER
LEVEL DISTURBANCE MOVING OUT OF THE PLAINS IS STILL EXPECTED TO
PRODUCE WIDESPREAD RAIN AND A FEW THUNDERSTORMS FRIDAY
MORNING...OVER ESPECIALLY SOUTHEAST IOWA INTO WEST CENTRAL
ILLINOIS. OVERNIGHT...POCKETS OF CLEARING SKIES MAY LEAD TO SOME
MVFR FOG WHICH IS INCLUDED AT CID AND DBQ. RAIN DEVELOPING FRIDAY
MORNING IS EXPECTED TO RESULT IN PERIODS OF VISIBILITIES IN A 5 TO
6 MILE RANGE. WILL CONTINUE TO FOCUS THE GREATEST POTENTIAL FOR
THUNDERSTORMS IN THE MID TO LATE AFTERNOON HOURS. RAIN AND
THUNDERSTORMS WILL END FROM NORTH TO SOUTH IN THE EVENING...
TRANSITIONING CONDITIONS TO PREVAILING VFR AT CID AND DBQ WHERE WEST
TO SOUTHWEST WINDS WILL BECOME LIGHT NORTHEAST.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...08
SHORT TERM...08
LONG TERM...STOFLET
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1132 PM CDT Thu Aug 1 2013
.UPDATE...
ISSUED AT 917 PM CDT THU AUG 1 2013
Convection continues to progress south southeast similar to what
the backward propagating Corfidi vectors would forecast...and
latest LAPS analysis shows the axis of low level moisture
convergence over northern KS. The HRRR has shown good consistency
with bringing the MCS into the area overnight...and with the RAP
and NAM continuing to show the advection of high theta-e air into
northeast KS with persistent isentropic upglide...hard to see what
would cause the MCS to fall apart before moving across the area. With
increasing confidence that the MCS will track across the
area...have increased pops and gone with categorical wording into
Friday morning.
UPDATE ISSUED AT 610 PM CDT THU AUG 1 2013
Convection across eastern NEB continues to propagate south
southeast as the backward propagating Corfidi vectors would
forecast. Think that as the low level jet veers to the southwest
and continues to advect moisture into northeast KS...that the
storms in NEB should hold together and move into the forecast
area. The HRRR appears to have a reasonable handle on this
convection and would expect it to move into northeastern KS
between 10 pm and midnight. RAP and NAM progs suggest that the
boundary layer will be stabilizing by then so there continues to
be some uncertainty in potential for severe storms. Steep mid
level lapse rates initially as the storms move south and deep
layer sheer around 40 kts would be supportive from some organized
storms. Although it still looks like some kind of MCS will
propagate across the area overnight tonight rather than discrete
storms making strong wind gusts more of a concern if the boundary
layer does not stabilize as forecast.
&&
.SHORT TERM...(THIS EVENING THROUGH Friday)
ISSUED AT 347 PM CDT THU AUG 1 2013
Surface high pressure has slid off to the southeast this afternoon
with light southerly flow building into the area. The atmosphere
remains quite moist in the low levels with dewpoints in the middle
60s to lower 70s across the forecast area while temperatures have
risen into the upper 80s. These low level conditions have combined
with moderate lapse rates to produce a moderately unstable airmass
across central and eastern Kansas. Any cap appears to be quite weak
this afternoon but low level convergence and upper forcing are both
at a minimum, and most signs point to little to no convection
through the afternoon hours. However, a short wave trough moving
from South Dakota into Nebraska this afternoon has helped kick off a
few clusters of severe thunderstorms near the Nebraska border and
this activity is expected to move south and southeast this evening.
While the activity over Nebraska will initially be supercellular in
nature, expect it to eventually congeal cold pools and surge to the
south, likely with forward propagating segments and LEWP structures
and perhaps with embedded areas of mid level supercell rotation.
Instability will weaken a bit into the evening hours but should
still be sufficient when paired with large hodographs and strong
deep layer shear to pose a threat for severe weather as it moves
into eastern Kansas. The primary question at the current time is the
strength of the cap that will develop later in the evening. Most
model forecast soundings suggest that the cap does develop but if an
organized cold pool can lift parcels to 5 or 6 thousand feet, it
should be able to maintain surface based convection. Based on the
strength of the activity ongoing, would tend to believe that surface
based strong to severe convection could persist at least into
northern Kansas, and perhaps across the entire area as the MCS dives
south. The primary severe threat would seem to be damaging winds
although there is at least marginal potential for large hail
especially if some supercell characteristics can be maintained. The
tornado threat appears to be very very small. Will also have to
monitor potential for flooding in case the forward propagation of
the system stops and the low level jet kicks into existing
boundaries.
Expect remnant showers and convection to be ongoing Friday morning,
and any outflow boundaries will play a large role in thunderstorm
and severe weather potential for Friday afternoon. As of now, expect
a slightly better chance of outflow pushing all the way through the
forecast area, potentially keeping some of the area stable by
afternoon. However, if the sun comes out to quickly warm the post
outflow airmass, could see a fairly good severe weather setup by
afternoon. For now, there are too many uncertainties to get
specific, but the potential for storms certainly exists.
Barjenbruch
.LONG TERM...(Friday NIGHT THROUGH Thursday)
ISSUED AT 347 PM CDT THU AUG 1 2013
Friday night through Thursday...
Friday night as the LLJ increases moisture convergence develops
across NE KS which may be the focus for additional thunderstorm
development as the sfc front slowly progresses into the southern
portion of the CWA. The better chances for precip appear to be
across east central KS, although not confident if the lift will be
strong enough to get convection started. On Saturday during the day
the front continues to move south into OK as weak shortwave
disturbances slide eastward along the northern edge of the mid/upper
level high. This lift may cause an isolated shower or thunderstorm
across the southern CWA, but most areas will likely be dry. On
Saturday night a stronger shortwave is forecast to approach the area
from the central Rockies bringing the chances for rain therefore
pops increase during the overnight hours. The best chance for rain
will be Sunday as the deep layer moisture increases ahead of the
shortwave and warm air advection spreads eastward out of western KS.
High temperatures on Saturday will be in the mid to upper 80s and
slightly cooler on Sunday with cloud cover and rain chances.
Monday through Thursday...
The area remains under NW mid/upper level flow as the upper high
anchors over the southern Plains. Shortwaves embedded within the
flow are forecast to bring numerous rain chances to the area. Around
mid week a stronger mid/upper level low will dive southward into
southern Canada suppressing the ridge out west bringing more of a
zonal flow to the Central Plains. High temperatures will continue to
be below average with the chances of rain.
Sanders
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Friday NIGHT)
ISSUED AT 1132 PM CDT THU AUG 1 2013
The convective system continues to move through south towards the
terminals...and has weakened suggesting the boundary layer has
stabilized somewhat. Think SHRA with embedded TS will persist
until the westward extend of the MCS dies or moves east. Models
show QPF hanging on well into Friday morning...but were also to
slow to bring the cold pool into KS. because of this will hedge to
precip ending sooner than models have. Conditions should be VFR
unless a heavier downpour moves through which could cause some
temporary MVFR VSBY and CIGS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...BARJENBRUCH
LONG TERM...SANDERS
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1141 PM CDT THU AUG 1 2013
.AVIATION...
VFR CONDITIONS EXPECTED NEXT 24-30 HOURS ALL TERMINALS. CONVECTION
EXPECTED TO BE MUCH LESS IN COVERAGE FRIDAY. 24/RR
&&
.SOUNDING DISCUSSION...
NO PROBLEMS WITH LAUNCH THIS EVENING. RATHER STEEP LAPSE RATE
SURFACE TO 850 MB...A MODEST ISOTHERMAL LAYER TO 810 MB THEN A
MOIST...POSSIBLY VIRGA MODIFIED LAPSE RATE TO 550 MB BEFORE
BECOMING PSEUDO TO TROPOPAUSE AT 145 MB. WINDS W-NW 5 KT SURFACE
TO 4500 FT...NNW-NNE 15-55 KT ABOVE...PEAK WIND 355/56KT AT
43.3KFT. P.W. 2.08 INCHES...HIGH CAPE OF 4319 J/KG AND STORM
MOTION 031/08KT. 24/RR
&&
.PREV DISCUSSION... /ISSUED 330 PM CDT THU AUG 1 2013/
SHORT TERM...
A SOMEWHAT ACTIVE AFTERNOON FOR PORTIONS OF THE FORECAST AREA
BRINGS HIGHER RAIN CHANCES. A COLD FRONT HAS BEEN SLOWLY TRACKING
RIGHT ACROSS MID MISSISSIPPI AND SHOULD BE APPROACHING LATER THIS
AFTERNOON. CONVECTION HAS BEGUN TO FIRE OFF AHEAD OF THE BOUNDARY
NORTH OF THE CWA. LOCAL WRF ALONG WITH HRRR IN FAIRLY GOOD AGREEMENT
DENOTING THAT CURRENT ACTIVITY WHICH IS TYPICAL OF THIS TIME OF
YEAR WILL INCREASE IN COVERAGE AS WELL AS INTENSITY AND MOVE ACROSS
THE CWA. PRECIP WATER VALUES ARE STILL QUITE HIGH AT OVER 2
INCHES...SO EXPECT VERY HEAVY RAIN WITH ANY STORMS THAT DO DEVELOP.
WIND SHEAR IS QUITE LIGHT AND WEST BULB TEMP WELL ABOVE 13K FEET
MEANS LITTLE THREAT OF HAIL OR TORNADOES. THUS THE MAIN THREAT WILL
BE GUSTY WINDS ON THE ORDER OF 35-45 MPH. SEVERE GUSTS NOT
IMPOSSIBLE BUT UNLIKELY. CONVECTION WILL LIKELY PERSIST THROUGH
SUNSET BUT NOT MUCH LONGER AFTER THAT. MAIN THREAT AREA APPEARS TO
BE EAST OF INTERSTATE 55 FROM MS ALL THE WAY TO SOUTH OF NEW
ORLEANS. HAVE BUMPED UP POPS SLIGHTLY FROM PREVIOUS FORECAST.
MEFFER
LONG TERM...
UPPER LEVEL TROUGH WILL LIFT NORTH AND RIDGE WILL BEGIN EXTENDING IN
OVER THE AREA FRIDAY THROUGH THE WEEKEND. WHILE A FEW STORMS MAY
DEVELOP...CONVECTION SHOULD BE QUITE LIMITED. EASTERN EDGE OF THE
UPPER LEVEL RIDGE WILL BEGIN WEAKENING LATE THIS WEEKEND THROUGH THE
MIDDLE OF NEXT WEEK. THIS WILL ALLOW FOR A FEW RAIN CHANCES TO
INCREASE ACROSS THE AREA. TEMPERATURES THROUGH THE ENTIRE PERIOD
WILL NOT CHANCE MUCH WITH HIGHS GENERALLY IN THE 90-95 DEGREE RANGE
WITH HEAT INDEX VALUES 100 TO 105. MID WEEK ONWARD THE RIDGE WILL
MOVE DIRECTLY OVER THE NORTHERN GULF COAST. ECMWF SUGGESTS A
SLIGHTLY STRONGER RIDGE WITH LOWER POPS AND HIGHER TEMPS WHILE GFS
IS MORE OF A WEAKER RIDGE WHICH WOULD ALLOW FOR MORE CONVECTION. SO
HAVE MADE LITTLE TO NO CHANGES TO THE EXTENDED FORECAST.
MEFFER
AVIATION...
GENERALLY VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH 00Z
SATURDAY AT THE TERMINAL LOCATIONS. THE POSSIBLE EXCEPTIONS WILL BE
ASSOCIATED WITH THE POTENTIAL FOR LIGHT FOG DEVELOPMENT TOWARD
DAYBREAK FRIDAY MORNING AT THE MORE FOG PRONE TAF SITES. THE
TERMINALS IN THE SOUTH HALF OF THE FORECAST AREA ARE THE ONES THAT
WILL HAVE THE BEST CHANCE OF SEEING ANY CONVECTION...NAMELY
KHUM...KNEW AND KMSY...BUT RAIN CHANCES WILL REMAIN SLIM.
18
MARINE...
A RIDGE OF HIGH PRESSURE WILL FLUCTUATE BETWEEN THE EASTERN AND
CENTRAL GULF THROUGHOUT THE FORECAST PERIOD. GENERALLY LIGHT SOUTH
TO WESTERLY AND AT TIMES VARIABLE WINDS AROUND 10 KNOTS OR LESS ARE
EXPECTED ALONG WITH WAVES HEIGHTS OF 2 FEET OR LESS.
MEFFER
DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NATURAL GAS WELL BLOWOUT SUPPORT.
SLURRY SUPPORT.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 74 95 73 94 / 10 10 10 10
BTR 77 96 76 95 / 10 10 10 10
ASD 76 94 76 93 / 20 20 10 20
MSY 79 93 78 92 / 20 20 10 20
GPT 77 93 77 93 / 20 20 10 20
PQL 73 94 73 93 / 20 20 10 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
221 AM EDT FRI AUG 2 2013
.SYNOPSIS...
ISSUED AT 407 PM EDT THU AUG 1 2013
A SERIES OF WEAK DISTURBANCES WILL DRIFT INTO NORTHERN MICHIGAN
THROUGH FRIDAY...BRINGING LOW CHANCES OF SHOWERS AND POSSIBLY A
THUNDERSTORM. THE BEST CHANCE WILL BE IN NORTHEAST LOWER
MICHIGAN BUT MOST COMMUNITIES WILL SEE RATHER PLEASANT WEATHER.
HIGH PRESSURE WILL BUILD INTO THE WESTERN GREAT LAKES OVER THE
WEEKEND...RESULTING IN COOLER AND RAIN FREE WEATHER. THE NEXT
CHANCE FOR RAIN DOES NOT ARRIVE UNTIL NEXT WORK WEEK.
&&
.UPDATE...
ISSUED AT 219 AM EDT FRI AUG 2 2013
SHOWERS ARE EXPANDING OUT AHEAD OF A SHORTWAVE IN THE ARROWHEAD OF
MN. LATEST HRRR/RUC BOTH SUPPORTING CONTINUED EXPANSION OF THE
SHOWERS AND EMBEDDED STORMS WITHIN COLD POL ALOFT AND STEEP MID
LEVEL LAPSE RATES. INCREASED CHANCES OF RAIN FOR THESE SHOWERS
ARRIVING TOWARD DAYBREAK IN EASTERN UPPER AND INTO THE REMAINDER
OF NRN MICHIGAN THIS MORNING.
UPDATE ISSUED AT 1012 PM EDT THU AUG 1 2013
A SOMEWHAT UNCERTAIN NIGHTTIME FORECAST. FIRST...A RENEGADE SHRA
IS STEADILY CROSSING LAKE MI...HEADING TOWARD THE COAST BETWEEN
FRANKFORT AND EMPIRE. IT ISN/T TERRIBLY HEALTHY LOOKING...BUT HAS
HELD TOGETHER BETTER THAN ANYTHING ELSE TO THIS POINT. VERY SHORT-
TERM GRIDS CONTINUE TO BE UPDATED TO ACCOUNT FOR A FEW SHRA LATE
THIS EVENING.
THE OVERNIGHT...IN THE BIG PICTURE...FEATURES LOWERING HEIGHTS AND
STEEPENING MID-LEVEL LAPSE RATES (TO 6.25-6.5C/KM 700-500MB). WV
IMAGERY SHOWS A SHORTWAVE MOVING ESE-WARD ACROSS NORTHERN MN...AS
MOST MODELS INDICATE. WAVE WILL REACH CENTRAL TO NORTHERN LOWER MI
TOWARD MORNING. CURRENTLY...MOST OF THE SHRA/TSRA ACTIVITY IS
ALONG THE NORTHERN FLANK OF THE WAVE...OVER FAR NORTHERN MN AND
ADJOINING PORTIONS OF CANADA. AT THE LOW LEVELS...WNW-ERLY FLOW WILL
PERSIST FROM 850MB ON DOWN...PERHAPS SOME VERY SHALLOW BACKING AT
950MB TOWARD 12Z. STILL...NOTHING RESEMBLING A CLASSIC LOW LEVEL JET.
SHORT-TERM HI-REZ MODELS ARE ALL OVER THE PLACE. THE NAM BRINGS
PRECIP INTO WESTERN SECTIONS BY DAWN...THE RUC DOES THE SAME TO
NORTHERN/EASTERN SECTIONS...THE WRF-NMM TO THE SOUTH...THE LOCAL
4KM WRF TO NOBODY.
GIVEN WHERE PRECIP IS NOW IN RELATION TO WHERE THE SHORTWAVE IS
PROGGED TO GO...FAVORS THE GOING FORECAST...WHICH HAS THE HIGHEST
POPS IN EASTERN UPPER INTO SOME SECTIONS OF FAR NE LOWER (RUC-
LIKE). THAT SAID...ALSO AGREE IN KEEPING AT LEAST A SLIGHT CHANCE
IN ALL AREAS AFTER 09Z.
MINOR CHANGES AT MOST TO CLOUD COVER AND MINS.
UPDATE ISSUED AT 703 PM EDT THU AUG 1 2013
DIURNAL CONVECTION OVER NORTHERN MI SEEMS TO HAVE JUST ABOUT RUN
ITS COURSE. INSTABILITY OVER FAR SE UPPER MI...AND IN THE SAGINAW
BAY REGION...HAS BEEN JUST ABOUT USED UP. SPC MESO PAGE INDICATING
LESS THAN 500J/KG ACROSS THE ENTIRE FORECAST AREA...WITH THE
HIGHEST POCKET IN NE LOWER S OF APN. INCOMING CONVECTIVE REMNANTS
HAVE MOVED INTO NW LOWER WITHOUT REGENERATION. SHOULD BE ABLE TO
GET AWAY WITH ISOLATED POPS FOR THE COUPLE OF HOURS OR SO...AND
NOTHING THEREAFTER.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CENTERED OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WHILE A VERY PERSISTENT UPPER TROUGH
REMAINS OVER CENTRAL CANADA AND THE GREAT LAKES REGION. THIS PATTERN
WILL SWEEP A COUPLE BOUNDARIES OVER NRN MI...MAINLY FRIDAY. AN UPPER
LVL COLD POOL ASSOCIATED WITH THE 500MB TROUGH NEAR HUDSON BAY WILL
CONTINUE TO SINK INTO THE NORTHERN LAKES THROUGH FRIDAY...HELPING
KEEP TEMPS AT MID LEVELS AROUND 8C/9C WHILE 500MB TEMPS DROP TO
-18C. THIS VERTICAL TEMPERATURE PROFILE WILL STEEPEN MID LEVEL
LAPSE RATES TO NEARLY 6C/KM TONIGHT INTO FRIDAY EVENING. EXPECT
CONVECTION THIS AFTERNOON WILL DIMINISH THIS EVENING WITH LACK OF
SOLAR RADIATION AND PRESENCE OF ANY BOUNDARY...THOUGH BECOME MORE
WIDESPREAD FRIDAY AFTERNOON ONCE AGAIN IN ADVANCE OF APPROACHING
SURFACE AND UPPER LEVEL FEATURES. MODEL SOUNDINGS SHOWING THE BEST
CONVERGENCE ASSOCIATED WITH APPROACHING BOUNDARIES FRIDAY...TO
FINALLY EXIT EAST INTO LAKE HURON AFTER 18Z FRIDAY.
OVERALL WILL KEEP SMALL CHC`S OF SHOWERS AND THUNDERSTORMS ACROSS
THE CWA TONIGHT AND FRIDAY. WILL MENTION HIGH TEMPS FRIDAY SIMILAR
TO THURSDAY TEMP VALUES...IN THE LOWER 70S...AS UPPER TROUGH AND
850/500MB TEMPS REMAIN THE SAME.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
OVERVIEW: 4-WAVE LONGWAVE PATTERN IN PLACE ACROSS THE NORTHERN
HEMISPHERE TO START THIS FORECAST PERIOD...ONE LONG WAVE TROUGH AXIS
BISECTED THE MIDWEST (AROUND 90W) AND BOUNDED BY RIDGING ALONG EACH
COAST. THIS PATTERN IS FORECAST TO CHANGE VERY LITTLE THROUGH THE
EXTENDED FORECAST...ALTHOUGH WITH SLOW EASTWARD MIGRATION OF THE
LONGWAVE TROUGH INTO THE GREAT LAKES/NEW ENGLAND AND SHARP
RIDGING/VERY WARM TEMPS IN THE WEST. THIS KEEPS OVERALL COOL/BELOW
NORMAL TEMPS INTACT FOR THE REGION THROUGH NEXT WEEK.
WEATHER-WISE THROUGH SUNDAY...WE START OUT ON THE UNSETTLED SIDE OF
THINGS FOR THE END OF THE WORK WEEK AS A COUPLE SHORT WAVES DIP
THROUGH THE GREAT LAKES REGION. HOWEVER...DEVELOPING NW FLOW ALOFT
FRIDAY NIGHT AND HEADING INTO THE WEEKEND LEADS TO A LARGE EXPANSE
OF HIGH PRESSURE BUILDING ACROSS THE NRN PLAINS THROUGH THE GREAT
LAKES. THIS WILL SET THE STAGE FOR QUIET WEATHER FOR THIS UPCOMING
WEEKEND...ALBEIT CONTINUED COOL-ISH WITH DAYTIME TEMPS RUNNING
AROUND 10 DEGREES BELOW NORMAL.
MONDAY THROUGH THURSDAY...QUIET WEATHER TO START NEXT WORK WEEK WITH
HIGH PRESSURE/NORTHWEST FLOW ALOFT AND COOLER TEMPS STILL SETTLED
OVER THE REGION. THEN...TUESDAY THROUGH THURSDAY BECOMES A BIT MORE
NEBULOUS AS STRONGER SHORT WAVE AND ASSOCIATED CLOSED LOW DROP OUT
OF CENTRAL CANADA DOWN INTO THE MIDWEST/GREAT LAKES. MODEL
TIMING/RUN-TO-RUN DIFFERENCES REGARDING THE PATTERN EVOLUTION ADD TO
THE UNCERTAINTY AS THE ECMWF TURNS DOWNRIGHT COOL ONCE AGAIN BY LATE
NEXT WEEK WITH ANOTHER CLOSED LOW/POCKET OF COOL AIR DESCENDING OVER
THE GREAT LAKES (BY COMPARISON...GFS IS MORE PROGRESSIVE AND
WARMER). WILL HAVE CHANCY POPS AND BELOW NORMAL TEMPS THROUGH THE
TUESDAY-THURSDAY TIMEFRAME GIVEN THE PROXIMITY TO THE TIGHTER
BAROCLINIC ZONE... ALTHOUGH A FAIR AMOUNT OF UNCERTAINTY SURROUNDS
THIS TIMEFRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1158 PM EDT THU AUG 1 2013
MAINLY VFR...THOUGH PRECIP COULD PRODUCE BRIEF RESTRICTIONS VERY
LATE TONIGHT INTO FRIDAY. ALSO SOME EARLY AM FOG AT PLN.
LOW PRESSURE ON HUDSON BAY CONTINUES TO PUSH OCCASIONAL COLD
FRONTS ACROSS NORTHERN MI. THE NEXT WILL MOVE ACROSS THE AREA
FRIDAY AFTERNOON. SOME SHRA CONTINUE TO PERCOLATE OVER LAKE MI
AHEAD OF THIS SYSTEM. SOMEWHAT MORE WIDESPREAD SHRA WILL DEVELOP
ESE-WARD INTO EASTERN UPPER AND FAR NORTHERN LOWER...INCLUDING
PLN/APN. ANOTHER ROUND OF SHRA/PERHAPS TSRA WILL DEVELOP AHEAD OF
THE FRONT...MAINLY OVER N CENTRAL LOWER MI AND POINTS EAST
(AGAIN...APN/PLN HAVE THE BEST CHANCE OF BEING IMPACTED).
LIGHT WINDS TONIGHT...STARTING OUT FROM THE SW FRIDAY MORNING THEN
VEERING NW TO N IN THE AFTERNOON/EVENING (BECOMING NE OFF THE
LAKE AT APN).
&&
.MARINE...
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CURRENTLY OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WITH A COUPLE OF WEAK BOUNDARIES
SWEEPING OVER THE GREAT LAKES THROUGH FRIDAY. EXPECT WINDS AND
WAVES TO REMAIN BELOW SCA CRITERIA THRU THE PERIOD...WITH WESTERLY
WINDS TONIGHT TRENDING NORTHWEST BY FRIDAY. &&
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...SD
SYNOPSIS...NS
SHORT TERM...SR
LONG TERM...BA
AVIATION...JZ
MARINE...SR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 AM EDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 910 PM EDT THU AUG 1 2013
SHOWERS AND ISOLATED THUNDERSTORMS HAVE MOVED INTO WESTERN LAKE
SUPERIOR AHEAD OF THE UPPER SHORT WAVE OVER NW MN. THE SUSPICION IS
THAT MANY OF THESE ARE DIURNALLY DRIVEN AS THE INTENSITY OF THEM
OVER MN HAVE SEEMED TO DIMINISH OVER THE LAST HOUR OR TWO.
HOWEVER...THE COMBINATION OF THE UPPER DISTURBANCE MOVING OVER LAKE
SUPERIOR TONIGHT...AND MUCH OF THE AREA BEING UNDER THE LEFT EXIT
REGION OF THE UPPER JET WOULD SUGGEST AT SOME SCATTERED SHOWERS
MOVING ACROSS THE AREA OVERNIGHT...ESPECIALLY ACROSS LAKE SUPERIOR
AND THE KEWEENAW PENINSULA. AS SUCH...HAVE INTRODUCED SCATTERED
SHOWERS INTO THE FORECAST IN THOSE AREAS....AND ISOLATED SHOWERS
ACROSS THE REMAINDER OF THE AREA. THIS IS SIMILAR TO WHAT THE THE
LOCAL RAPID UPDATE WRF MODEL AND HRRR SUGGEST. WILL ALSO MAINTAIN A
SMALL CHANCE FOR THUNDER OVERNIGHT AS 850-500MB LAPSE RATES STEEPEN
TO NEARLY 7 C/KM AS THE UPPER WAVE MOVES OVERHEAD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 409 PM EDT THU AUG 1 2013
SMALL CHANCES OF SHOWERS WILL CONTINUE THROUGH FRIDAY AS THE REGION
REMAINS UNDER THE INFLUENCE OF MULTIPLE WEAK SHORTWAVES DIGGING
SOUTHEAST ON THE BACKSIDE OF A BROAD MID-LEVEL LOW OVER NORTHERN
ONTARIO.
TONIGHT...ONGOING SHOWERS ACROSS THE INTERIOR EAST HALF ON THE FIRST
SHORTWAVE WILL DIMINISH WITH THE LOSS OF DAYTIME HEATING THIS
EVENING. THE SECOND SHORTWAVE IN THE WEAK WAVE-TRAIN WILL PASS OVER
THE CWA OVERNIGHT...AND ONCE AGAIN BRING A SLIGHT CHANCE OF SHOWERS.
THIS WAVE IS CURRENTLY CROSSING LAKE WINNIPEG...AND IS EXPECTED TO
ARRIVE ACROSS THE WESTERN CWA AFTER MIDNIGHT. WATER VAPOR IMAGERY
GIVES THE SHORTWAVE A RATHER BENIGN LOOK AS CLOUD COVER HAS
DIMINISHED SIGNIFICANTLY OVER THE PAST DAY. IT APPEARS THAT THE WAVE
HAS BECOME SOMEWHAT SHEARED OUT OVER NORTHERN SASKATCHEWAN.
UPPER-LEVEL JET SUPPORT WILL BE MARGINAL...WITH UPPER MI SITUATED
BETWEEN THE LEFT-EXIT AND ENTRANCE REGIONS OF THE JET.
NONETHELESS...SHOWERS AND A FEW STORMS HAVE DEVELOPED OVER SOUTHWEST
ONTARIO THIS AFTERNOON AND HIGH-RES MODELS CONTINUE TO BRING SHOWERS
INTO THE WEST HALF IN THE EVENING. HAVE THEREFORE KEPT POPS IN THE
FORECAST...BUT LIMITED THEM TO LOW-END SLIGHT CHANCES FOLLOWING THE
WINDOW OF BEST FORCING FROM WEST TO EAST ACROSS THE CWA. HAVE ALSO
LEFT POPS HIGHER OVER THE EAST TOWARD 12Z FRIDAY AS THE INFLUENCE OF
THE INCOMING LAST SHORTWAVE...MENTIONED BELOW...PROVIDES SOME
ASSISTANCE TO THE DEPARTING WAVE.
FRIDAY...THE FINAL SHORTWAVE IS EXPECTED TO BE A BIT MORE POTENT
THAN THE PREVIOUS TWO...AND WILL BE TRACKING SOUTHEAST ACROSS THE
ARROWHEAD OF MN TO JUST WEST OF THUNDER BAY BY 12Z FRIDAY. MODEL
TRENDS HAVE BEEN FAIRLY CONSISTENT...THOUGH THE NAM HAS TRENDED
TOWARD A SLIGHT STRONGER TROUGH OVER THE PAST FEW RUNS. MOISTURE
AVAILABILITY WILL BE LOW...WITH LESS THAN 10 PERCENT RH THROUGH MUCH
OF THE LAYER ABOVE 700 MB ACROSS THE WEST HALF. THE BEST CHANCE OF
SEEING ANY PRECIP STILL LOOKS TO BE ACROSS THE INTERIOR EAST HALF IN
THE AFTERNOON AS HEATING AND LAKE BREEZE CONVERGENCE ASSIST WITH
LIFT FROM THE SHORTWAVE. MID-LEVEL MOISTURE WILL ALSO A BIT
HIGHER...THOUGH STILL RATHER DRY...ACROSS THE EAST HALF. SAW NO
REASON TO CHANGE THE GOING FORECAST OTHER THAN TO MAKE SOME TWEAKS
IN TIMING AND PLACEMENT IN THE MESOSCALE. THAT INCLUDED EXPANDING
POPS WESTWARD TO THE INTERIOR CENTRAL DURING PEAK HEATING GIVEN
TODAYS TRENDS OF A FEW LIGHT SHOWERS DEVELOPING ALBEIT POOR
MOISTURE. AS FOR THUNDER POTENTIAL...MLCAPE IS PROGGED TO BE A
MEAGER 500 J/KG WITH NORMALIZED CAPE LESS THAN 0.1. THIS WOULD GIVE
POTENTIAL FOR AT LEAST SOME ISOLATED LIGHTNING IN ANY OF THE
STRONGER SHOWERS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 409 PM EDT THU AUG 1 2013
TROUGH OVER THE EASTERN HALF OF CANADA AND NE U.S./GREAT LAKES
REGION STAYS IN PLACE THROUGH MOST OF THE EXTENDED PERIOD OF THE
FCST DUE TO PERSISTENT REX BLOCK OVER NW CANADA AND THE PAC NW COAST
AND MEAN RDGG OVER THE NORTH ATLANTIC. AS A RESULT OF THIS PATTERN
...TEMPS SHOULD REMAIN AT OR BELOW NORMAL THROUGH THE PERIOD. A
SERIES OF NW FLOW SHORTWAVES ROTATING ON THE SRN/WRN PERIPHERY OF
THE ERN CANADIAN TROUGH WILL BRING PERIODIC SHRA TO WEST AND CENTRAL
UPPER MI MAINLY FOR EARLY TO MID NEXT WEEK.
SAT-SUN...THE WEEKEND LOOKS DRY WITH LOW-LEVEL FLOW BECOMING
INCREASINGLY ANTICYCLONIC AS SFC-H85 HIGH PRESSURE EXPANDS FROM
CENTRAL CANADA ACROSS MUCH OF THE GREAT LAKES REGION. 5H COLD POOL
SLIDES EAST...TAKING STEEPER MID-LVL LAPSE RATES WITH IT...SO NOT
EXPECTING ANY DIURNAL AFTERNOON SHRA. TEMPS SATURDAY WILL BE ON THE
COOLER SIDE OF NORMAL ESPECIALLY NEAR LK SUPERIOR WHERE 60S READINGS
ARE EXPECTED WITH ONSHORE NW WINDS. WARMEST TEMPS WILL BE FAR SOUTH
CENTRAL AWAY FROM THE COOLING INFLUENCE OF LAKE SUPERIOR...EXPECT
READINGS THERE IN THE LOWER TO MID 70S. TEMPS ON SUNDAY SHOULD REACH
THE 70S OVER MUCH OF THE AREA...EXCEPT LOCALLY COOLER 60S READINGS
NEAR THE GREAT LAKES SHORELINES.
MON-TUE...MODELS INDICATE RETURN SW FLOW OF HIGHER SFC DEW POINTS
INTO THE AREA FOR MONDAY INTO TUESDAY AS SFC RDG AXIS SLIDES TO THE
EAST. THE INCREASED MOISTURE ALONG WITH PERIODIC SHORTWAVES AND THE
APPROACH OF A FRONTAL BOUNDARY FM THE NW WILL WARRANT CARRYING SOME
LOW CHC POPS FOR SHRA/ISOLD TSRA MAINLY CENTRAL AND EAST WHERE
INSTABILITY WILL BE GREATEST AND LOW-LVL CONVERGENCE WILL BE AIDED
BY LAKE BREEZES.
WED-THU...THE 12Z ECMWF IS STILL THE SLOWEST MOVING THROUGH INITIAL
COLD FRONT AND HAS IT POSITIONED OVER THE SCNTRL AND ERN CWA AT 12Z
WED. THUS...WILL NEED TO MAINTAIN LOW CHC POPS FOR SHRA OVER THESE
AREAS ON WED. ECMWF CONTINUES TO MAINTAIN DEEPER CLOSED LOW OVER THE
UPPER GREAT LAKES ON THU AND THE 12Z RUN SHOWS A STRONG SHORTWAVE
MOVING THROUGH THE AREA THU AFTERNOON WHILE DEVELOPING AFTERNOON
SHRA OVER THE CENTRAL AND ERN FCST AREA. THE ECMWF IS THE ONLY ONE
OF THE 12Z MODELS TO SHOW THIS STRONG SHORTWAVE/CLOSED LOW ROTATING
THROUGH THE AREA. SO FOR NOW GIVEN MODEL UNCERTAINTY WILL ONLY HAVE
SLIGHT CHC POPS FOR SHRA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 139 AM EDT FRI AUG 2 2013
SCATTERED SHOWERS WITH EMBEDDED THUNDERSTORMS HAVE SPREAD INTO THE
WESTERN UPPER PENINSULA AHEAD OF A WEAK UPPER DISTURBANCE. THESE
SHOWERS SHOULD RAPIDLY MOVE EAST THROUGH THE AREA BY 12Z. AS ANY
SHOWER MOVES OVERHEAD...CONDITIONS MAY BRIEFLY DROP TO MVFR
ESPECIALLY AT IWD AND CMX...BUT OVERALL CONDITIONS SHOULD REMAIN VFR
OVERNIGHT. GENERALLY QUIET DAY ON FRIDAY WITH DRY AIR MOVING ACROSS
THE REGION. COULD SEE A SHOWER OR STORM ALONG THE LAKE BREEZE IN THE
EASTERN PART OF UPPER MICHIGAN FRI AFTN AS ANOTHER UPPER DISTURBANCE
PASSES BY...BUT THE EXPECTATION IS THAT THESE WILL STAY OUT OF THE
TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT THU AUG 1 2013
QUIET WEATHER WILL CONTINUE ACROSS LAKE SUPERIOR THROUGH THE
PERIOD...WITH WINDS REMAINING UNDER 20 KNOTS. A SERIES OF WEAK
TROUGHS WILL CROSS THE LAKE THROUGH FRIDAY AFTERNOON AND BRING SMALL
CHANCES OF SHOWERS. HIGH PRESSURE WILL THEN TAKE HOLD OF THE UPPER
GREAT LAKES FOR THE WEEKEND. ANOTHER TROUGH WILL TRACK SOUTHEAST
FROM NORTHERN ONTARIO INTO THE UPPER GREAT LAKES MONDAY NIGHT INTO
TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MRD
SHORT TERM...KLUBER
LONG TERM...VOSS
AVIATION...MRD
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1202 AM EDT FRI AUG 2 2013
.SYNOPSIS...
ISSUED AT 407 PM EDT THU AUG 1 2013
A SERIES OF WEAK DISTURBANCES WILL DRIFT INTO NORTHERN MICHIGAN
THROUGH FRIDAY...BRINGING LOW CHANCES OF SHOWERS AND POSSIBLY A
THUNDERSTORM. THE BEST CHANCE WILL BE IN NORTHEAST LOWER
MICHIGAN BUT MOST COMMUNITIES WILL SEE RATHER PLEASANT WEATHER.
HIGH PRESSURE WILL BUILD INTO THE WESTERN GREAT LAKES OVER THE
WEEKEND...RESULTING IN COOLER AND RAIN FREE WEATHER. THE NEXT
CHANCE FOR RAIN DOES NOT ARRIVE UNTIL NEXT WORK WEEK.
&&
.UPDATE...
ISSUED AT 1012 PM EDT THU AUG 1 2013
A SOMEWHAT UNCERTAIN NIGHTTIME FORECAST. FIRST...A RENEGADE SHRA
IS STEADILY CROSSING LAKE MI...HEADING TOWARD THE COAST BETWEEN
FRANKFORT AND EMPIRE. IT ISN/T TERRIBLY HEALTHY LOOKING...BUT HAS
HELD TOGETHER BETTER THAN ANYTHING ELSE TO THIS POINT. VERY SHORT-
TERM GRIDS CONTINUE TO BE UPDATED TO ACCOUNT FOR A FEW SHRA LATE
THIS EVENING.
THE OVERNIGHT...IN THE BIG PICTURE...FEATURES LOWERING HEIGHTS AND
STEEPENING MID-LEVEL LAPSE RATES (TO 6.25-6.5C/KM 700-500MB). WV
IMAGERY SHOWS A SHORTWAVE MOVING ESE-WARD ACROSS NORTHERN MN...AS
MOST MODELS INDICATE. WAVE WILL REACH CENTRAL TO NORTHERN LOWER MI
TOWARD MORNING. CURRENTLY...MOST OF THE SHRA/TSRA ACTIVITY IS
ALONG THE NORTHERN FLANK OF THE WAVE...OVER FAR NORTHERN MN AND
ADJOINING PORTIONS OF CANADA. AT THE LOW LEVELS...WNW-ERLY FLOW WILL
PERSIST FROM 850MB ON DOWN...PERHAPS SOME VERY SHALLOW BACKING AT
950MB TOWARD 12Z. STILL...NOTHING RESEMBLING A CLASSIC LOW LEVEL JET.
SHORT-TERM HI-REZ MODELS ARE ALL OVER THE PLACE. THE NAM BRINGS
PRECIP INTO WESTERN SECTIONS BY DAWN...THE RUC DOES THE SAME TO
NORTHERN/EASTERN SECTIONS...THE WRF-NMM TO THE SOUTH...THE LOCAL
4KM WRF TO NOBODY.
GIVEN WHERE PRECIP IS NOW IN RELATION TO WHERE THE SHORTWAVE IS
PROGGED TO GO...FAVORS THE GOING FORECAST...WHICH HAS THE HIGHEST
POPS IN EASTERN UPPER INTO SOME SECTIONS OF FAR NE LOWER (RUC-
LIKE). THAT SAID...ALSO AGREE IN KEEPING AT LEAST A SLIGHT CHANCE
IN ALL AREAS AFTER 09Z.
MINOR CHANGES AT MOST TO CLOUD COVER AND MINS.
UPDATE ISSUED AT 703 PM EDT THU AUG 1 2013
DIURNAL CONVECTION OVER NORTHERN MI SEEMS TO HAVE JUST ABOUT RUN
ITS COURSE. INSTABILITY OVER FAR SE UPPER MI...AND IN THE SAGINAW
BAY REGION...HAS BEEN JUST ABOUT USED UP. SPC MESO PAGE INDICATING
LESS THAN 500J/KG ACROSS THE ENTIRE FORECAST AREA...WITH THE
HIGHEST POCKET IN NE LOWER S OF APN. INCOMING CONVECTIVE REMNANTS
HAVE MOVED INTO NW LOWER WITHOUT REGENERATION. SHOULD BE ABLE TO
GET AWAY WITH ISOLATED POPS FOR THE COUPLE OF HOURS OR SO...AND
NOTHING THEREAFTER.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CENTERED OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WHILE A VERY PERSISTENT UPPER TROUGH
REMAINS OVER CENTRAL CANADA AND THE GREAT LAKES REGION. THIS PATTERN
WILL SWEEP A COUPLE BOUNDARIES OVER NRN MI...MAINLY FRIDAY. AN UPPER
LVL COLD POOL ASSOCIATED WITH THE 500MB TROUGH NEAR HUDSON BAY WILL
CONTINUE TO SINK INTO THE NORTHERN LAKES THROUGH FRIDAY...HELPING
KEEP TEMPS AT MID LEVELS AROUND 8C/9C WHILE 500MB TEMPS DROP TO
-18C. THIS VERTICAL TEMPERATURE PROFILE WILL STEEPEN MID LEVEL
LAPSE RATES TO NEARLY 6C/KM TONIGHT INTO FRIDAY EVENING. EXPECT
CONVECTION THIS AFTERNOON WILL DIMINISH THIS EVENING WITH LACK OF
SOLAR RADIATION AND PRESENCE OF ANY BOUNDARY...THOUGH BECOME MORE
WIDESPREAD FRIDAY AFTERNOON ONCE AGAIN IN ADVANCE OF APPROACHING
SURFACE AND UPPER LEVEL FEATURES. MODEL SOUNDINGS SHOWING THE BEST
CONVERGENCE ASSOCIATED WITH APPROACHING BOUNDARIES FRIDAY...TO
FINALLY EXIT EAST INTO LAKE HURON AFTER 18Z FRIDAY.
OVERALL WILL KEEP SMALL CHC`S OF SHOWERS AND THUNDERSTORMS ACROSS
THE CWA TONIGHT AND FRIDAY. WILL MENTION HIGH TEMPS FRIDAY SIMILAR
TO THURSDAY TEMP VALUES...IN THE LOWER 70S...AS UPPER TROUGH AND
850/500MB TEMPS REMAIN THE SAME.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
OVERVIEW: 4-WAVE LONGWAVE PATTERN IN PLACE ACROSS THE NORTHERN
HEMISPHERE TO START THIS FORECAST PERIOD...ONE LONG WAVE TROUGH AXIS
BISECTED THE MIDWEST (AROUND 90W) AND BOUNDED BY RIDGING ALONG EACH
COAST. THIS PATTERN IS FORECAST TO CHANGE VERY LITTLE THROUGH THE
EXTENDED FORECAST...ALTHOUGH WITH SLOW EASTWARD MIGRATION OF THE
LONGWAVE TROUGH INTO THE GREAT LAKES/NEW ENGLAND AND SHARP
RIDGING/VERY WARM TEMPS IN THE WEST. THIS KEEPS OVERALL COOL/BELOW
NORMAL TEMPS INTACT FOR THE REGION THROUGH NEXT WEEK.
WEATHER-WISE THROUGH SUNDAY...WE START OUT ON THE UNSETTLED SIDE OF
THINGS FOR THE END OF THE WORK WEEK AS A COUPLE SHORT WAVES DIP
THROUGH THE GREAT LAKES REGION. HOWEVER...DEVELOPING NW FLOW ALOFT
FRIDAY NIGHT AND HEADING INTO THE WEEKEND LEADS TO A LARGE EXPANSE
OF HIGH PRESSURE BUILDING ACROSS THE NRN PLAINS THROUGH THE GREAT
LAKES. THIS WILL SET THE STAGE FOR QUIET WEATHER FOR THIS UPCOMING
WEEKEND...ALBEIT CONTINUED COOL-ISH WITH DAYTIME TEMPS RUNNING
AROUND 10 DEGREES BELOW NORMAL.
MONDAY THROUGH THURSDAY...QUIET WEATHER TO START NEXT WORK WEEK WITH
HIGH PRESSURE/NORTHWEST FLOW ALOFT AND COOLER TEMPS STILL SETTLED
OVER THE REGION. THEN...TUESDAY THROUGH THURSDAY BECOMES A BIT MORE
NEBULOUS AS STRONGER SHORT WAVE AND ASSOCIATED CLOSED LOW DROP OUT
OF CENTRAL CANADA DOWN INTO THE MIDWEST/GREAT LAKES. MODEL
TIMING/RUN-TO-RUN DIFFERENCES REGARDING THE PATTERN EVOLUTION ADD TO
THE UNCERTAINTY AS THE ECMWF TURNS DOWNRIGHT COOL ONCE AGAIN BY LATE
NEXT WEEK WITH ANOTHER CLOSED LOW/POCKET OF COOL AIR DESCENDING OVER
THE GREAT LAKES (BY COMPARISON...GFS IS MORE PROGRESSIVE AND
WARMER). WILL HAVE CHANCY POPS AND BELOW NORMAL TEMPS THROUGH THE
TUESDAY-THURSDAY TIMEFRAME GIVEN THE PROXIMITY TO THE TIGHTER
BAROCLINIC ZONE... ALTHOUGH A FAIR AMOUNT OF UNCERTAINTY SURROUNDS
THIS TIMEFRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1158 PM EDT THU AUG 1 2013
MAINLY VFR...THOUGH PRECIP COULD PRODUCE BRIEF RESTRICTIONS VERY
LATE TONIGHT INTO FRIDAY. ALSO SOME EARLY AM FOG AT PLN.
LOW PRESSURE ON HUDSON BAY CONTINUES TO PUSH OCCASIONAL COLD
FRONTS ACROSS NORTHERN MI. THE NEXT WILL MOVE ACROSS THE AREA
FRIDAY AFTERNOON. SOME SHRA CONTINUE TO PERCOLATE OVER LAKE MI
AHEAD OF THIS SYSTEM. SOMEWHAT MORE WIDESPREAD SHRA WILL DEVELOP
ESE-WARD INTO EASTERN UPPER AND FAR NORTHERN LOWER...INCLUDING
PLN/APN. ANOTHER ROUND OF SHRA/PERHAPS TSRA WILL DEVELOP AHEAD OF
THE FRONT...MAINLY OVER N CENTRAL LOWER MI AND POINTS EAST
(AGAIN...APN/PLN HAVE THE BEST CHANCE OF BEING IMPACTED).
LIGHT WINDS TONIGHT...STARTING OUT FROM THE SW FRIDAY MORNING THEN
VEERING NW TO N IN THE AFTERNOON/EVENING (BECOMING NE OFF THE
LAKE AT APN).
&&
.MARINE...
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CURRENTLY OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WITH A COUPLE OF WEAK BOUNDARIES
SWEEPING OVER THE GREAT LAKES THROUGH FRIDAY. EXPECT WINDS AND
WAVES TO REMAIN BELOW SCA CRITERIA THRU THE PERIOD...WITH WESTERLY
WINDS TONIGHT TRENDING NORTHWEST BY FRIDAY. &&
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JZ
SYNOPSIS...NS
SHORT TERM...SR
LONG TERM...BA
AVIATION...JZ
MARINE...SR
AREA FORECAST DISCUSSION
NWS JACKSON MS
415 AM CDT FRI AUG 2 2013
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT...ANOTHER HOT DAY ON TAP
TODAY...ESPECIALLY IN THE SOUTHWEST HALF OF THE REGION WHERE THE
AIRMASS WILL BE MORE HUMID. BOUNDARY THAT PUSHED THROUGH YESTERDAY
TRIGGERING AFTERNOON SHOWERS AND STORMS IN SOUTH MS IS NOW RATHER
WASHED OUT NEAR THE COAST WITH CURRENT SURFACE REFLECTION OF LOWER
HUMIDITY AND TEMPS REALLY ONLY VERY EVIDENT FROM GREENVILLE SOUTH TO
MERIDIAN AND POINTS NORTHEAST. MOISTURE POOLED AT 5000 FEET ABOVE
GROUND DUE TO THE BOUNDARY IS NOW EVIDENT ALONG AND SOUTH OF I-20 AS
SCATTERED CLOUDS. PREVIOUS EXPECTATIONS WERE FOR VERY MINIMAL RAIN
CHANCES TODAY BUT NOW IT SEEMS AT LEAST VERY ISOLATED SHOWERS AND
STORMS WILL LIKELY TRIGGER IN MANY CENTRAL AND SOUTHERN ZONES THANKS
TO THE RESERVOIR OF POOLED MOISTURE. LATEST HRRR EXPLICIT OUTPUT
SUGGESTS AS MUCH. DO NOT THINK THIS ACTIVITY WILL ULTIMATELY WET
MANY PEOPLE OR CUT HEAT...BUT IT WAS WORTH MENTIONING IN FORECAST.
HIGHS WILL RANGE FROM 94 TO 97 WITH HOTTEST TEMPS IN CENTRAL AND
SOUTHERN ZONES WHERE PEAK HEAT INDICES MAY MEET OR EXCEED 105 FOR AN
HOUR OR TWO IN SOME SPOTS...ESPECIALLY WEST OF THE MS RIVER.
CONSIDERED A HEAT ADVISORY FOR THESE AREAS BUT EXPLICIT CRITERIA NOT
QUITE BEING MET.
TONIGHT...LARGE CURRENT SOUTHEAST PROPAGATING MCS IN EASTERN KANSAS
COULD HAVE A COUSIN CLOSER TO THE VICINITY OF MY NORTHWEST ZONES BY
THE WEE HOURS. CHANCES FOR ANY PRECIPITATION IN SUCH A SCENARIO
GETTING INTO THE REGION BEFORE DAWN ARE VERY LOW...BUT DEBRIS CLOUDS
BLOWING DOWNSTREAM COULD HOLD UP TEMPS SOMEWHAT. OTHERWISE...EXPECT
QUIET CONDITIONS WITH POTENTIAL FOR BUILDING SOUTHERLY FLOW TO
PRODUCE SOME LOW STRATUS IN SOUTHERN HALF OF ZONES BY DAWN SATURDAY.
SATURDAY AND SATURDAY NIGHT...ANY EARLY MORNING MCS ACTIVITY
REFERRED TO ABOVE SHOULD BE DECAYING AS IT TRIES TO ENTER INTO THE
REGION FROM THE NORTHWEST THROUGH THE FIRST HALF OF THE DAY.
WILDCARD OF A POTENTIAL MCV SPURRING SOME CONVECTION IN THE
NORTHEAST HALF OF ZONES WARRANTS SLIGHT CHANCE OF SHOWERS AND STORMS
MENTION...BUT ONLY THAT MUCH SINCE MANY OTHER FACTORS REMAIN RATHER
HOSTILE TO ANY MORE THAN ISOLATED COVERAGE. REGARDLESS OF WHETHER
THERE IS ACTUAL PRECIP HITTING THE GROUND ANYWHERE...CHANCES ARE
GOOD THERE WILL BE A FAIR AMOUNT OF HIGH TO MID LEVEL CLOUDS AROUND
TO REDUCE INSOLATION A BIT. THIS EXPLAINS MEX TEMPS A LITTLE COOLER
THAN TODAY IN MANY AREAS. HUMIDITY WILL BE INCREASING ACROSS THE
BOARD THOUGH AND PEAK HEAT INDEX WILL COME CLOSE OR EXCEED 100
DEGREES IN MOST LOCATIONS. BY SATURDAY NIGHT THE POTENTIAL FOR
JUXTAPOSITION OF CONVECTIVE BOUNDARIES...NON-TRIVIAL MOISTURE
CONVERGENCE...AND PASSING WEAK DISTURBANCES IN NORTHWEST FLOW
SUGGEST SOME CHANCE OF SOUTHERN FRINGE OF TN VALLEY AND MIDSOUTH
THUNDERSTORM ACTIVITY BRUSHING NORTHERN HALF OF ZONES. ONLY SLIGHT
CHANCE POPS FOR NOW. /BB/
.LONG TERM...SUNDAY THROUGH NEXT FRIDAY...MODELS CONTINUE TO AGREE
WITH KEEPING THE MID/UPPER RIDGE WEDGED INTO THE FORECAST AREA FROM
THE WEST THROUGH AT LEAST THE MID-RANGE PORTION OF THE FORECAST...
BEFORE SHIFTING IT EAST AND NEARLY DIRECTLY OVER THE ARKLAMISS
DURING THE EXTENDED. THE BEST RAIN CHANCES CONTINUE TO LOOK TO BE
FAIRLY EARLY IN THE PERIOD...SPECIFICALLY SUNDAY...MONDAY...AND
TUESDAY AFTERNOONS...AND ON THE EASTERN PERIPHERY OF THIS RIDGE AS
NORTHERLY FLOW TRIES TO SETUP OVER REGION. THIS IN ADDITION TO
INCREASED LOW LEVEL MOISTURE AND A WEAK SURFACE BOUNDARY THAT`S
PROGGED TO DROP SOUTH INTO THE CWA SUNDAY...AND EVENTUALLY WASHOUT
ON TUESDAY. CHANCES FOR SHOWERS AND STORMS WILL LINGER THROUGH THE
REMAINDER OF THE FORECAST PERIOD...WEDNESDAY THROUGH FRIDAY...BUT
CHANCES WILL BE LOWER AND THE CENTER OF THE RIDGE IS AGAIN EXPECTED
TO SHIFT ALMOST DIRECTLY OVER THE FORECAST AREA.
I DIDN`T STRAY FAR FROM GFS GUIDANCE IN TERMS OF TEMPERATURES.
OVERALL...HIGHS EACH AFTERNOON WILL CLIMB INTO THE MIDDLE 90S WITH
PLENTY OF HUMIDITY PRESENT AS DEW POINTS GENERALLY SIT AROUND 70F.
THIS LOOKS TO YIELD A FEW PERIODS THROUGHOUT EACH DAY WHERE HEAT
INDICES COULD CLIMB BETWEEN 100-105F. THAT SAID...FORECAST HIGHS
COULD OBVIOUSLY BE LOWER IF CLOUD COVER AND/OR CONVECTION ARE MORE
PREVALENT...WHICH IN TURN WOULD HELP KEEP HEAT INDEX VALUES IN
CHECK. LOWS EACH NIGHT WILL REMAIN MILD AND ONLY FALL INTO THE
MIDDLE 70S. /19/
&&
.AVIATION...POTENTIAL FOR MVFR MIST AND HAZE BEFORE 10 AM THIS
MORNING AT GLH/GWO/GTR/CBM/MEI/NMM...WHILE MVFR TO TEMPORARILY IFR
CEILINGS AND VIS POSSIBLE THROUGH THAT TIME AT PIB/HBG WHERE THE
GROUND IS DAMP FROM YESTERDAY`S RAINS. AFTER 10 AM EXPECT VFR
CONDITIONS THE REST OF THE DAY AND THROUGH THE EVENING WITH LIGHT
AND ERRATIC WINDS. AN ISOLATED SHOWER OR STORM IS POSSIBLE ALONG AND
SOUTH OF I-20 TODAY...BUT CHANCES OF HITTING TAF SITE ARE QUITE LOW.
LATE TONIGHT POTENTIAL FOR AT LEAST MVFR STRATUS OR MIST WILL EXIST
PRIMARILY AT JAN/HKS/MEI/NMM/PIB/HBG. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 97 73 95 76 / 11 9 16 16
MERIDIAN 95 71 95 74 / 3 9 17 16
VICKSBURG 96 73 95 73 / 11 8 13 13
HATTIESBURG 97 74 96 75 / 11 10 10 10
NATCHEZ 95 74 95 74 / 11 9 10 8
GREENVILLE 95 74 95 76 / 3 11 20 20
GREENWOOD 95 71 95 75 / 3 8 21 20
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BB/19
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
310 AM CDT FRI AUG 2 2013
.DISCUSSION...
A RELATIVELY UNSETTLED WEATHER PATTERN WILL CONTINUE OVER OUR PART
OF THE COUNTRY INTO NEXT WEEK AS WE REMAIN UNDER FAST WEST TO
NORTHWEST FLOW ALOFT BETWEEN LARGE/DEEP UPPER LOW IN CANADA AND
BROAD HIGH IN THE SOUTHERN STATES. SEVERAL IMPULSES WILL WORK
THROUGH THIS FLOW THROUGH NEXT WEEK...BRINGING OCCASIONAL
THUNDERSTORM CHANCES AS SURFACE FRONT WOBBLES NORTH/SOUTH
AHEAD/BEHIND EACH WAVE.
FOR TODAY...MOST THUNDERSTORM ACTIVITY ASSOCIATED WITH THURSDAY
AFTERNOON/EVENING CONVECTION HAS SHIFTED SOUTH OF OUR AREA. HOWEVER
STRENGTHENING LOW LEVEL JET IN CENTRAL NEBRASKA HAS FIRED ADDITIONAL
STORMS IN SOUTH CENTRAL SOUTH DAKOTA. THIS ACTIVITY WILL LIKELY
DRIFT/DEVELOP EAST AND SOUTHEAST INTO NORTHEAST NEBRASKA AS LOW
LEVEL JET BECOMES SOUTHWESTERLY WITH TIME THIS MORNING. MODELS WERE
NOT HANDLING THIS PRECIPITATION PARTICULARLY WELL...BUT A BLEND OF
RAP AND HRRR SOLUTIONS OFFERS SOME RELIABILITY. EXPECT RAIN WITH
EMBEDDED STORMS CURRENTLY IN SOUTH CENTRAL NEBRASKA TO SPREAD ACROSS
THE SOUTHWEST THIRD OF THE CWA THROUGH MID MORNING WITH A DECREASING
TREND INTO EARLY AFTERNOON. SEVERE STORMS ARE NOT ANTICIPATED AS
ATMOSPHERE WAS WORKED OVER FAIRLY WELL OVERNIGHT. ANOTHER ROUND OF
STORMS COULD THEN DEVELOP IN THE MID TO LATE AFTERNOON AS A
SHORTWAVE EJECTS FROM THE HIGH PLAINS OF WYOMING/MONTANA AND SLIDES
SOUTHEAST. STORMS WOULD MOST LIKELY FORM IN SOUTH CENTRAL SOUTH
DAKOTA OR NORTH CENTRAL NEBRASKA THEN SPREAD SOUTHEAST ACROSS THE
WESTERN CWA DURING THE LATE AFTERNOON AND EVENING. SURFACE DEW
POINTS ARE FORECAST TO APPROACH 70...HELPING TO GENERATE 3000 J/KG
OR GREATER SURFACE-BASED CAPE OVER PARTS OF THE CWA. EXACT AXIS OF
HIGHEST INSTABILITY WILL BE AFFECTED BY ONGOING ACTIVITY THIS
MORNING...BUT LOOKS LIKE IT WILL SET UP OVER THE SOUTHERN HALF OF
OUR AREA. FARTHER NORTH...FASTER MID LEVEL FLOW WILL YIELD 50KT OF
BULK SHEAR...SO ANY STORMS THAT WORK INTO NORTHEAST NEBRASKA WILL BE
POTENTIALLY SEVERE AS WELL.
CONVECTION SHOULD BE SETTLING SOUTH OF NEBRASKA AFTER MIDNIGHT AS
SHORTWAVE MOVES OFF TO THE EAST. MOST OF SATURDAY THEN LOOKS DRY
WITH FOCUS FOR STORMS IN THE HIGH PLAINS. THEN THE NEXT SHORTWAVE
SHOULD BE ROLLING INTO THE AREA SATURDAY NIGHT SETTING UP ANOTHER
ROUND OF STORMS AS LOW LEVEL JET ONCE AGAIN DRIVES CONVECTION IN
WARM ADVECTION REGIME. THIS CONVECTION WILL LIKELY LINGER INTO AT
LEAST SUNDAY MORNING BEFORE MOVING OFF TO THE SOUTHEAST.
MUCH OF THE SAME IS FORECAST FOR NEXT WEEK. MONDAY OFFERS THE BEST
CHANCE FOR A DRY FORECAST BEFORE A STRONGER SHORTWAVE PUSHES A FRONT
THROUGH OUR AREA TUESDAY...WHICH THEN LIFTS BACK NORTH ON WEDNESDAY.
WILL NOT CHANGE FORECAST MUCH FROM GOING NUMBERS TUESDAY THROUGH
THURSDAY AS TIMING SHORTWAVES THIS FAR OUT IS DIFFICULT. HOWEVER
PATTERN CERTAINLY FAVORS AT LEAST A CHANCE FOR STORMS EACH DAY.
DERGAN
&&
.AVIATION...06Z TAFS FOR KOFK...KOMA AND KLNK.
AREA OF THUNDERSTORMS HAD MOVED WELL SOUTH OF KOFK AND KOMA
WITH KLNK ON THE NORTHERN EDGE AT 06Z. EXPECT SOUTHEAST
TREND IN MOVEMENT TO CONTINUE WITH NO MENTION OF CONVECTION
IN THE TAFS. SOME POTENTIAL FOR LIGHT FOG AND POSSIBLE LIFR CIGS
FOR A TIME AROUND SUNRISE ESPECIALLY IF MORE SIGNIFICANT CLEARING
OCCURS WITH KOFK LOOKING TO HAVE THE BETTER CHANCE OF THIS
DEVELOPMENT. VFR CONDITIONS PREVAIL AFTER 17Z AS SOUTHEAST WINDS
INCREASE TO AROUND 10KTS.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1229 AM CDT FRI AUG 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 PM CDT THU AUG 1 2013
MORNING MAP ANALYSIS INDICATES MID TO UPPER LEVEL RIDGING OVER THE
WESTERN CONUS...WITH A TROUGH OVER THE EAST. MID TO UPPER LEVEL JET
ENERGY EXTENDS FROM THE WEST-CENTRAL CONUS...NORTHEAST INTO THE
NORTHERN ROCKY MOUNTAIN RANGE...AND THEN SOUTHEAST ACROSS PORTIONS
OF THE PLAINS AND MISSISSIPPI VALLEY...AND FINALLY EAST/NORTHEAST
INTO THE EASTERN CONUS. NORTHWESTERLY MID TO UPPER LEVEL FLOW
PERSISTS OVER THE CENTRAL PLAINS AS A RESULT. A ~110KT UPPER LEVEL
JET STREAK IS ALSO NOTED EXTENDING FROM THE NORTHERN
PLAINS...SOUTHEAST INTO THE MID-MISSISSIPPI VALLEY. MID TO UPPER
LEVEL FLOW MAXES OUT AT AROUND 100KTS NEAR 200MB PER RAP ANALYSIS
AND 12Z SOUNDING DATA FROM KOAX. AT THE SURFACE A RIDGE OF HIGH
PRESSURE EXTENDS FROM THE MISSOURI RIVER VALLEY...SOUTH/SOUTHEAST
INTO PORTIONS OF THE MID-MISSISSIPPI VALLEY. LEE SIDE TROUGHING ALSO
EXTENDS FROM SOUTHEASTERN WYOMING INTO EASTERN COLORADO AND AS A
RESULT...SOUTHERLY LOW LEVEL FLOW IS INFILTRATING OUR CWA.
FOR THE REST OF THIS AFTERNOON AND EVENING...CONTINUED SOUTHERLY LOW
LEVEL FLOW...ENHANCED BY THE DEVELOPMENT OF A 25-30KT 850MB JET
STREAK...WILL PROMOTE INCREASING THERMAL ADVECTION ACROSS MUCH OF
OUR AREA. ISENTROPIC UPGLIDE AND
SATURATION...PRIMARILY ALONG THE 310-320K SURFACES...IS EXPECTED TO
PROMOTE PRECIPITATION PRODUCTION ACROSS THE AREA. INCREASED VALUES
OF LOW LEVEL MOISTURE SHOULD CONTINUE PROMOTING DECENT VALUES OF
POTENTIAL INSTABILITY...WITH THE NAM AND OPERATIONAL GFS BOTH
SUGGESTING MUCAPE VALUES NEAR 3000J/KG ACROSS MUCH OF THE AREA. IN
ADDITION TO THE POTENTIAL INSTABILITY...DEEP LAYER BULK SHEAR VALUES
ON THE ORDER OF 40-50KTS IS ALSO EXPECTED. GIVEN ALL THIS...SEVERE
WEATHER REMAINS POSSIBLE THIS AFTERNOON INTO THIS EVENING...WITH
LARGE HAIL AND STRONG THUNDERSTORM WIND GUSTS BEING THE PRIMARY
SEVERE WEATHER THREATS. IN ADDITION THE HAIL AND WIND THREAT
HOWEVER...FORECAST PROXIMITY SOUNDINGS FROM VARIOUS MODELS SUGGEST A
SIGNIFICANTLY VEERING LOW LEVEL WIND PROFILE THUS HELPING PROMOTE
SRH VALUES NEAR 200M^2/S^2 ACROSS PORTIONS OF OUR CWA. GIVEN
THIS...WILL ALSO CONTINUE THE TORNADO MENTION IN THE HWO.
GUIDANCE SUGGESTS THE AFOREMENTIONED THERMAL ADVECTION SHOULD HELP
MAINTAIN PRECIPITATION PRODUCTION ACROSS THE AREA TONIGHT...WITH
MUCH OF THIS ACTIVITY MOVING OFF TO EAST BY EARLY FRIDAY MORNING. IT
WOULD APPEAR AS THOUGH THE SEVERE WEATHER THREAT SHOULD DIMINISH
HEADING INTO THE OVERNIGHT HOURS. THAT BEING SAID...WITH A
PERSISTENT SOUTHERLY LOW LEVEL WIND FIELD...INCREASING SIGNIFICANTLY
ABOVE THE BOUNDARY LAYER PRIMARILY DUE TO A ~50KT LOW LEVEL
JET...MAY HELP PROMOTE NOCTURNAL MCS DEVELOPMENT. WILL CONTINUE THE
MENTION OF SEVERE WEATHER ACROSS THE AREA THROUGH THE OVERNIGHT
HOURS AS A RESULT...BUT THE DETAILS OF ANY POTENTIAL MCS DEVELOPMENT
WILL NOT LIKELY BECOME ANY MORE CLEAR UNTIL LATER TONIGHT.
THE PRIMARY AXIS OF THERMAL ADVECTION SHOULD DEPART THE AREA TO THE
EAST ON FRIDAY...THUS ALLOWING FOR DECREASING PRECIPITATION CHANCES.
THAT BEING SAID...MID LEVEL PERTURBATIONS MOVING OVER THE AREA WITHIN
THE MEAN FLOW SHOULD STILL PROMOTE ENOUGH OMEGA FOR FURTHER
PRECIPITATION PRODUCTION ACROSS PORTIONS OF OUR CWA STARTING FRIDAY
AFTERNOON. SHOULD THUNDERSTORM ACTIVITY BE REALIZED FRIDAY
AFTERNOON...THEN SEVERE WEATHER COULD ONCE AGAIN BE REALIZED AS
GUIDANCE SUGGESTS MUCAPE VALUES NEAR 3000J/KG WILL ACCOMPANY DEEP
LAYER BULK SHEAR VALUES OF 30-40KTS. GIVEN ALL THIS...WILL GO AHEAD
AND OUTLOOK SEVERE WEATHER FOR FRIDAY AS WELL.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CDT THU AUG 1 2013
FORECAST CONCERNS MAINLY FOCUSED ON THUNDERSTORMS.
MODELS ARE IN GOOD AGREEMENT THAT THE NORTHWEST FLOW REGIME WILL
PERSIST THROUGH THE PERIOD. THUS...EXPECT A PERIOD OF UNSETTLED
WEATHER WITH NORMAL OR BELOW NORMAL TEMPERATURES.
AT THE SURFACE...A BROAD AREA OF LOW PRESSURE ON THE LEE SIDE OF
THE ROCKIES WILL ANCHOR A WEAK FRONTAL BOUNDARY THAT WILL
OSCILLATE FROM KS TO SD THROUGH THE PERIOD. THE LOCATION OF THIS
BOUNDARY WILL BE THE FOCUS OF AFTERNOON CONVECTIVE INITIATION. THEN
STORMS SHOULD DRIFT SOUTH AND EAST THROUGH THE EVENING HOURS AS AN
MCS. THERE WILL BE GOOD INSTABILITY AND MOISTURE AVAILABLE...SO
SEVERE STORMS CAN NOT BE RULED OUT.
ALOFT...THE NORTHWEST FLOW WILL ALLOW FREQUENT AND WEAK WAVES TO
MOVE OVER THE AREA. THIS WILL OFFER ENOUGH SUPPORT TO GET INITIATE
THE CONVECTION.
TOWARDS THE END OF THE PERIOD (THURSDAY) A STRONGER COOL FRONT IS
FORECAST TO MOVE SOUTH ACROSS THE AREA. IF THIS
OCCURS...TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL AND IT
WILL BE DRY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1228 CDT FRI AUG 2 2013
BRUNT OF THUNDERSTORMS HAVE SLID SOUTH OF THE TERMINAL BUT A FEW
WEAKER RETURNS TO THE NORTHWEST SO WILL INSERT VICINITY FOR A FEW
HOURS. JUST A SMALL CHANCE FOR REDEVELOPMENT FRI AFTERNOON AND
WILL LEAVE OUT MENTION FOR NOW. WINDS SHOULD SWING FROM SE TO NE
DURING THE FORECAST PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...BRYANT
LONG TERM...EDDY
AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1146 PM CDT THU AUG 1 2013
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
AREA OF THUNDERSTORMS HAD MOVED WELL SOUTH OF KOFK AND KOMA
WITH KLNK ON THE NORTHERN EDGE AT 06Z. EXPECT SOUTHEAST
TREND IN MOVEMENT TO CONTINUE WITH NO MENTION OF CONVECTION
IN THE TAFS. SOME POTENTIAL FOR LIGHT FOG AND POSSIBLE LIFR CIGS
FOR A TIME AROUND SUNRISE ESPECIALLY IF MORE SIGNIFICANT CLEARING
OCCURS WITH KOFK LOOKING TO HAVE THE BETTER CHANCE OF THIS
DEVELOPMENT. VFR CONDITIONS PREVAIL AFTER 17Z AS SOUTHEAST WINDS
INCREASE TO AROUND 10KTS.
&&
.PREV DISCUSSION... /ISSUED 320 PM CDT THU AUG 1 2013/
DISCUSSION...
ACTIVE WEATHER EXPECTED THIS EVENING AS A MATURE MCS ACROSS
NORTHERN NEBRASKA SHOULD ROLL EAST SOUTHEAST. SEVERE WATCH
REMAINS IN EFFECT FOR NORTHEAST NEBRASKA AND NORTHWEST IOWA...AND
A TORNADO WATCH IN EFFECT FOR MUCH OF NORTH CENTRAL NEBRASKA. HOP
WRF AND RAP SEEM TO HAVE THE BEST HANDLE ON DEVELOPING CONVECTION...
THUS WILL HAVE HIGH POPS THIS EVENING WITH A SEVERE THREAT. HAVE
ISSUED A COUPLE OF SEVERE WARNINGS IN EXTREME NORTHEAST NEBRASKA...
BUT WE HAVEN`T BEEN ABLE TO GET ANY HAIL REPORTS BIGGER THAN
DIME TO NICKEL SIZE. EFFECTIVE SHEAR REMAINS QUITE HIGH AT 50 TO
60 KNOTS...BUT MID LEVEL LAPSE RATES ARE SLIGHTLY MARGINAL. WILL
ALSO CONTINUE TO MONITOR TRENDS AND ISSUE WARNINGS AS NECESSARY
FOR LARGE HAIL AND DAMAGING WINDS WITHIN THE STRONGEST CORES...AND
MAY HAVE TO EVENTUALLY EXTEND THE WATCH FURTHER EAST/SOUTHEAST
TOWARD THE I80 CORRIDOR IN TIME. THE BACK EDGE OF THE PRECIPITATION
WILL PROBABLY STILL BE IN THE AREA FRIDAY MORNING MOVING OUT OF
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. THE AFTERNOON MAY BE MOSTLY
DRY...ALTHOUGH THERE DOES APPEAR TO BE ANOTHER WEAK SURGE OF
MOISTURE MOVING SOUTH...WHICH COULD BRING A SLIGHT CHANCE OF
STORMS FRIDAY NIGHT.
BY SATURDAY...HIGH PRESSURE NOSING SOUTH OUT OF THE DAKOTAS SHOULD
KEEP SATURDAY DRY AND SLIGHTLY COOLER. THIS NORTHEASTERLY FLOW
BECOMES EAST SATURDAY NIGHT. AT THE SAME TIME...THERE IS ANOTHER
WAVE MOVING OUT OF THE ROCKIES...SO IT WILL BE A BATTLE OF HOW FAR
EAST THIS SYSTEM CAN GET BY DAYBREAK SUNDAY...VERSUS THE DRY
EASTERLY FLOW WITH HIGH PRESSURE ACROSS THE MID MISSISSIPPI RIVER
VALLEY. CHANCES SHOULD SPREAD ACROSS THE FORECAST AREA SUNDAY
THOUGH...BUT MAY STILL STRUGGLE TO MOVE INTO WESTERN IOWA. WAVE
COULD MOSTLY BE EAST SOUTHEAST OF THE AREA SO SHOULD BE MOSTLY DRY
SUNDAY NIGHT.
FOR THE EXTENDED FORECAST...THE REGION REMAINS IN PESKY NORTHWEST
FLOW. FORECAST CHALLENGES REMAIN TRYING TO TIME WEAK WAVES INTO
THE AREA...THUS OVERALL FORECAST CONFIDENCE REMAINS LOW. TOWARD
THE END OF THE PERIOD...ANOTHER FRONT SETTLING SOUTH COULD BRING
SOME COOLER TEMPS TO THE REGION BY THURSDAY...BUT COULD ALSO SHUNT
ANY PRECIP THREAT OUT OF THE AREA AS WELL.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
408 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL CONTINUE TO DEVELOP ACROSS OUR
REGION TODAY. THIS COLD AIR ALOFT...COMBINED WITH SOME SURFACE
HEATING WILL HELP IN THE DEVELOPMENT OF ADDITIONAL SCATTERED SHOWERS
AND THUNDERSTORMS THIS AFTERNOON...WITH SOME STORMS CONTAINING SMALL
HAIL. THE CHANCES FOR SHOWERS WILL CONTINUE ON SATURDAY WITH
TEMPERATURES DROPPING TO BELOW NORMAL VALUES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 410 AM EDT FRIDAY...FCST CHALLENGE TODAY WL BE AREAL
COVERAGE/INTENSITY OF SHOWERS/ISOLATED STORMS...FOLLOWED BY
TEMPS. CRNT WATER VAPOR SHOWS DIGGING MID/UPPER LVL TROF ACRS THE
EASTERN GREAT LAKES WITH RIBBON OF ENHANCED JET STREAM WINDS FROM
THE OHIO VALLEY INTO WESTERN NY. SATL LOOP SHOWED PLENTY OF
POPCORN TYPE SHOWERS WITH EMBEDDED LIGHTNING ACTIVITY UPSTREAM
YESTERDAY AFTN ASSOCIATED WITH 5H VORT ACRS THE NORTHERN LAKES.
LARGE SCALE MODELS SHOW THIS ELONGATED VORT LOBE IMPACTING OUR
CENTRAL/NORTHERN CWA THIS AFTN...WHILE RIBBON OF ENHANCED DEEP
LAYER SHEAR ASSOCIATED WITH MID/UPPER LVL JET MAX IS LOCATED ACRS
THE MID ATLANTIC STATES. HOWEVER...FEEL ENOUGH CLRING WL DEVELOP
TO WARM SFC TEMPS INTO THE M/U 70S...AND CREATE SFC BASED CAPE
VALUES BTWN 1200 AND 1800 J/KG...ESPECIALLY AS COOLING ALOFT
OCCURS. THIS INSTABILITY WL PROMOTE STRONG ENOUGH UPDRAFTS TO
SUPPORT MENTION OF THUNDER WITH SOME SMALL HAIL POSSIBLE...GIVEN
WBZ HGHTS BTWN 8000 AND 9000 FT AND 500MB TEMPS BTWN -16C AND
-18C. WL MENTION SMALL HAIL POTENTIAL IN HWO. RAP 13 CONTS TO SHOW
BEST PVA WITH S/W ENERGY ARRIVING DURING MAX DAYTIME
HEATING...WITH BEST 850 TO 500MB RH ALONG THE INTERNATIONAL
BORDER. FEEL THE LIMITED DEEP LAYER RH AND PWS FALLING TO AROUND
1"...WL LIMIT AREAL COVERAGE OF SHOWERS/STORMS THIS AFTN...WL
MENTION CHC POPS WITH HIGHEST POPS ACRS THE NORTHERN MTNS OF
NY/VT. PROGGED 85H TEMPS BTWN 10-12C...WITH SOME MIXING/SUN WL
SUPPORT HIGHS MID/UPPER 70S CPV/SLV AND CT RIVER VALLEY WITH U60S
TO L70S MTN/NEK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 410 AM EDT FRIDAY...LITTLE CHANGE IN OVERALL FCSTER THINKING
WITH VERY GOOD AGREEMENT AMONG THE LARGE SCALE MODELS...WHICH
CONTS TO SUPPORT A DEEP MID/UPPER LVL TROF ACRS OUR CWA THRU THE
WEEKEND. THIS SYNOPTIC SCALE FEATURE WL RESULT IN BLW NORMAL TEMPS
AND CHCS FOR SHOWERS THRU SAT AFTN. FCST FOCUS WL BE TIMING
INDIVIDUAL S/W`S IN THE WEST TO NORTHWEST FLW ALOFT. POTENT 5H
VORT IS EXPECTED TO IMPACT OUR CWA BTWN 06Z AND 15Z FRIDAY
NIGHT/SATURDAY MORNING...WITH STRONG DYNAMICS AND SOME 850 TO
500MB RH PRESENT. GIVEN THE PROGGED LARGE SCALE ASCENT ASSOCIATED
WITH THIS FEATURE...WOULD NOT BE SURPRISED FOR A FEW ISOLATED
STORMS...ON FRIDAY NIGHT/SATURDAY MORNING. THIS ENERGY WL LIFT NE
OF OUR CWA BY 15Z SATURDAY...WITH MUCH DRIER AIR AND LARGE SCALE
SUBSIDENCE DEVELOPING. THINKING AREAL COVERAGE/INTENSITY OF
SHOWERS WL BE LIMITED ON SAT AFTN...DUE TO DRYING ALOFT AND PWS
FALLING BTWN 0.50 AND 0.75". WL MENTION SCHC VALLEYS TO CHC POPS
MTNS. SOUNDING PROFILES SHOW VERY MODEST CAPE/INSTABILITY WITH
VALUES BTWN 200-400 J/KG. FOR FRIDAY NIGHT TIME PERIOD...WL
MENTION HIGH CHC POPS WITH SOME LOW LIKELY POPS NORTHERN DACKS.
QPF WL RANGE BTWN 0.10 AND 0.25". PROGGED 85H TEMPS REMAIN BTWN
10-12C ON SAT...SUPPORTING SLIGHTLY BLW NORMAL TEMPS MAINLY 60S
MTNS TO 70S VALLEYS. ON SUNDAY...MID/UPPER LVL TROF SHARPENS ACRS
OUR FA...AS ANOTHER POTENT VORT AND SFC COLD FRNT IMPACT THE
REGION. GFS/NAM AND ECMWF SHOW BETTER MOISTURE PROFILES ACRS OUR
FA...ALONG WITH GREATER COVERAGE IN QPF. WL MENTION HIGH CHC POPS
ATTM...BUT AN INCREASE TO LIKELY POPS MAYBE NEEDED IF CRNT TRENDS
CONT. HIGHEST POPS AND QPF WL BE ACRS THE MTN AREAS...WITH
RAINFALL AMOUNTS BTWN 0.10 AND 0.25". SOUNDINGS SHOW LIMITED
INSTABILITY WITH CAPE VALUES ONLY BTWN 100 AND 300 J/KG...WL NOT
MENTION THUNDER ATTM. 85H TEMPS DROP SEVERAL DEGREES FROM SATURDAY
AND SUPPORT HIGHS U50S/L60S MTNS/NEK TO M60S TO L70S VALLEYS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 410 AM EDT FRIDAY...PRONOUNCED NORTHWEST FLOW ALOFT ON THE
BACKSIDE OF DEPARTING UPPER TROUGH WILL BRING COOLER AND DRIER
WEATHER TO THE AREA SUNDAY NIGHT INTO MONDAY. COLD AIR ADVECTION
ON MONDAY SUGGESTS HIGHS ONLY IN THE UPPER 60S TO THE MID
70S...WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR. DRY WEATHER CONTINUES MONDAY NIGHT INTO TUESDAY AS
FLOW ALOFT REMAINS FROM THE NORTHWEST. TEMPERATURES BEGIN TO
SLOWLY MODERATE WITH HIGH TEMPERATURES 2 TO 4 DEGREES WARMER THAN
MONDAY. THE TREND TOWARD MORE NORMAL TEMPERATURES BEGINS ON
WEDNESDAY AS FLOW ALOFT BACKS TO THE WEST AND ALLOWS FOR WARM AIR
ADVECTION TO TAKE PLACE. HIGHS WILL BE IN THE 70S TO AROUND 80
BOTH WEDNESDAY AND THURSDAY. THE WESTERLY FLOW ALOFT WILL ALLOW
FOR A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY. AS A RESULT...THE THREAT FOR SHOWERS WILL
RETURN AND WILL MENTION A CHANCE OF SHOWERS ON BOTH DAYS.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...EXPECT SHARP CHANGES IN CONDITIONS ACROSS
THE AREA THROUGH 12Z DUE TO LOW CLOUDS AND FOG. MID AND HIGH LEVEL
CLOUDS ARE GRADUALLY SHIFTING EAST EARLY THIS MORNING AND WHEREVER
THERE HAS BEEN SOME CLEARING...LOW CLOUDS AND FOG HAVE DEVELOPED.
THUS THROUGH 12Z YOU CAN GENERALLY EXPECT VFR/MVFR CONDITIONS...BUT
PERIODS OF LIFR/VLIFR CONDITIONS. AFTER 12Z...VFR CONDITIONS
SHOULD DEVELOP ALL AREAS QUICKLY AS SOUTH TO SOUTHWEST WINDS
INCREASE AND PROVIDE ENOUGH MIXING TO GET RID OF THE LOW CLOUDS
AND FOG. AN UPPER LEVEL DISTURBANCE COMBINED WITH AN INCREASINGLY
UNSTABLE ATMOSPHERE SUGGESTS SCATTERED SHOWERS AND A FEW
THUNDERSTORMS WILL DEVELOP OVER THE AREA AFTER 16Z AND CONTINUE
THROUGH THE REMAINDER OF THE PERIOD. EXPECT VFR/MVFR CONDITIONS
FROM 16Z THROUGH THE REMAINDER OF THE PERIOD.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...
06Z SATURDAY THROUGH 06Z MONDAY...SERIES OF UPPER LEVEL
DISTURBANCES WILL BRING SHOWERS TO THE REGION AT TIMES ALONG WITH
WIDELY SCATTERED STORMS. CONDITIONS LOWERING AT TIMES TO MVFR.
06Z MONDAY THROUGH 00Z WEDNESDAY...VFR CONDITIONS WITHIN A RIDGE
OF SFC HIGH PRESSURE.
&&
.EQUIPMENT...
AS OF 1100 PM EDT THURSDAY...NOAA WEATHER RADIO WXM 44...BROADCASTING
FROM THE TOP OF MOUNT ASCUTNEY VERMONT...WILL BE OFF THE AIR UNTIL
FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/RJS
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1256 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT THEN STALL
AND DISSIPATE OVER THE AREA ON FRIDAY. HIGH PRESSURE OFFSHORE WILL
THEN DOMINATE INTO THE FIRST PART OF THE WEEKEND. ANOTHER COLD
FRONT WILL APPROACH FROM THE NORTHWEST SUNDAY AND MOVE SOUTH OF
THE AREA BY MONDAY AS HIGH PRESSURE BUILDS ACROSS THE AREA. THE
HIGH WILL DRIFT OFFSHORE TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1255 AM FRIDAY...CONVECTION ASSOCIATED WITH THE UPPER
TROUGH/SHORTWAVE MOVING THROUGH CENTRAL NC AND SURFACE OUTFLOW
BOUNDARIES HAS WEAKENED DURING THE LAST HOUR AS CINH INCREAES AND
DRIER MID LEVEL AIR MIXES IN ALOFT. THE WEAK ILL DEFINED COLD
FRONT IS STILL WELL TO THE WEST FROM JUST EAST OF THE NC MONTAINS
INTO CENTRAL VIRGINIA. WITH STILL SUFFICENT LOW LEVEL INSTABILITY
AND MOISTURE TO WORK WITH WILL FORECAST 30-40% POPS THROUGH 08Z
THEN INDICATE DIMINISHING CHANCES FOR PRECIPITATION AS LOW LEVEL
CONVERGENCE DECREASES WITH THE WEAK FRONT FPRECAST TO MOVE INTO NC
COASTAL PLAIN BY 12Z FRIDAY BEFORE DISSIPATING. CLEARING SKIES
AND WET GROUND MAY LEAD TO SOME PATCHY FOG LATE BUT WINDS MAY NOT
COMPLETLY DECOUPLE WHICH SHOULD KEEP WIDESPREAD DENSE FOG AT BAY.
LOW TEMPS WILL BE TYPICAL OF SUMMERTIME...MAINLY 70-75 COOLEST
INLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM SATURDAY/...
WEATHER CONDITIONS MORE TYPICAL OF SUMMER RETURN FOR FRIDAY AS MID
LEVEL FLOW BECOMES MORE ZONAL. CUD SEE AN ISOLATED SHOWER OR
TSTORM ALONG THE SEABREEZE AND REMNANT WEAK SFC TROF OVER THE AREA
DURING THE AFTERNOON BUT MOST AREAS WILL BE DRY AND WARM. HIGHS
MAINLY IN THE UPPER 80S/NEAR 90 INLAND...MID 80S BEACHES.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
AS OF 3 PM THU...A BROAD UPPER TROF WILL REMAIN IN PLACE OVER THE
EASTERN US THROUGH THE MIDDLE OF NEXT WEEK FOLLOWED BY A RETURN TO
ZONAL FLOW. THIS UPPER TROF WILL ALLOW FOR AN UNSETTLED PATTERN TO
CONTINUE THROUGH MOST OF THE PERIOD. THE LONG TERM WILL START OUT
WITH THE REMNANTS OF A WEAK FRONT OVER THE MIDDLE OF THE STATE.
POPS WILL BE IN THE 20-30% RANGE WITH MOST OF THE ACTIVITY BEING
SEABREEZE-DRIVEN. ANY CONVECTION THAT DEVELOPS WILL DISSIPATE
QUICKLY SATURDAY EVENING. POPS RE-ENTER THE FORECAST AREA FROM THE
NORTH AFTER MIDNIGHT SATURDAY NIGHT AS A RATHER STRONG COLD FRONT
DROPS RAPIDLY SOUTH. THE FRONT WILL ENTER FROM THE NORTH SUNDAY
MORNING AND CONTINUE MOVING QUICKLY SOUTH DURING THE DAY. EXPECT
CONVECTION TO END IN THE FAR NORTH IN THE AFTERNOON AND THE
SOUTHERN COUNTIES BY LATE AFTERNOON. THE FRONT WILL HAVE A STRONG
PUSH BEHIND IT WITH GOOD LIFT AND CONVERGENCE ALONG AND AHEAD OF
THE BOUNDARY. A FEW STRONG STORMS COULD DEVELOP WITH STRONG GUSTY
WINDS THE MAIN THREAT. WINDEX VALUES FROM GFS/NAM/ECMWF FORECAST
SOUNDINGS AT 18Z SUNDAY ARE 45-50 KNOTS. A BRIEF PERIOD OF DRIER
AIR WILL SPREAD IN BEHIND THE FRONT SUNDAY NIGHT AND MONDAY WITH A
NORTH TO NORTHEAST WIND FLOW. THE POST FRONTAL HIGH WILL MOVE OFF
THE COAST ON TUESDAY WITH A SOUTHWEST FLOW RETURNING. THE FRONTAL
BOUNDARY WILL BE STATIONARY NOT FAR TO THE SOUTH THROUGH MOST OF
THE WEEK. THERE WILL BE A CHANCE OF SHOWERS/STORMS EACH
DAY...MAINLY THE SCATTERED AFTERNOON/EVENING VARIETY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH 18Z FRIDAY/
AS OF 1255 AM FRIDAY...CHANCES FOR SCATTERED
SHOWERS/THUNDERSTORMS WILL BEGIN TO DIMINISH AFTER 08Z AS DRIER
AIR ALOFT AND WEAKENING CONVERGENCE OCCUR ACROSS THE AREA. MAIN
CONCERN IS POTENTIAL FOR IFR CONDITIONS IN FOG AND STRATUS DUE TO
WET SOILS AND RADIATIONAL COOLING. NOT SURE IF WINDS COMPLETELY
DECOUPLE SO THINKING STRATUS MAY BE MORE OF A CONCERN. ALTHOUGH
THERE ARE FAVORABLE HYDROLAPSES THE UPS FOG TOOL AND BUFKIT
SUPPORT LIGHT FOG AND STRATUS VS DENSE FOG. THEREFORE LEANING
TOWARD LIMITING TO MVFR CONDITIONS ALL TAF SITES EXPCEPT FOR KOAJ
WHERE WINDS MAY DECOUPLE LONGEST. ON FRIDAY EXPECTING MAINLY VFR
CONDITIONS AS CONDITIONS WILL BE LESS FAVORBALE FOR DEEP
CONVECTION AS A DRIER AIRMASS BRIEFLY MOVES OVER THE AREA.
LONG TERM /FRI NIGHT THROUGH TUE/ AS OF 3 PM
THU...SCATTERED CONVECTION POSSIBLE EACH DAY. SOUTHWEST WINDS
FRIDAY NIGHT THROUGH SUNDAY MORNING. A FRONT WILL DROP SOUTH
THROUGH THE AREA ON SUNDAY WITH WINDS SHIFTING QUICKLY FROM
SOUTHWEST TO NORTH. SCATTERED STRONG STORMS POSSIBLE ALONG AND
AHEAD OF THE FRONT WITH SURFACE WIND GUSTS AS HIGH AS 50 KNOTS.
NORTH TO NORTHEAST WIND AND DRY WEATHER FORECAST FOR SUNDAY NIGHT
INTO MONDAY. WINDS BECOME SOUTHWEST ONCE AGAIN ON TUESDAY WITH THE
CHANCE OF AFTERNOON & EVENING CONVECTION.
&&
.MARINE...
SHORT TERM /THROUGH FRIDAY/
AS OF 1255 AM FRIDAY...NO CHANGES TO PREVIOUS FORECAST WITH
MARGINAL SMALL CRAFT ADVSIORY CONDITIONS OVER THE SOUTHERN AND
CENTRAL WATERS EXPECTED THROUGH EARLY FRIDAY. WINDS HAVE SHOWN AN
UPTICK OVER THE PAST COUPLE OF HOURS AND ARE BASICALLY 15 TO 20
KNOTS OVER MOST WATERS PER THE LATEST RAP WIND FORECAST. THE BUOY
30 MILES SOUTHEAST OF NEW RIVER INLET IS REPORTING 5-6 FOOT SEAS
AND WAVE MODELS HAVE BEEN CONSISTENT IN BUILDING 6+ FT SEAS IN
RESPONSE TO THE INCREASING S/SW WIND OVER CENTRAL AND SOUTHERN
WATERS. THE SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 6 AM
SOUTH OF OCRACOKE AND UNTIL 8 AM FROM OCRACOKE UP TO OREGON INLET.
WINDS GRADUALLY DIMINISHING AND BECOMING MORE WSW LATE TONIGHT AND
EARLY FRIDAY AS GRADIENT SLACKENS WITH SEAS LIKELY FALLING BLO 6
FT BY SUNRISE FRIDAY. SW WINDS WILL AGAIN INCREASE MODERATELY
FRIDAY AFTN IN RESPONSE TO INLAND THERMAL TROF BUT REMAINING BLO
15 KT. SEAS MAINLY 2-4 FT FRIDAY.
LONG TERM /FRI NIGHT THROUGH TUE/
AS OF 3 PM THU...SOUTHWEST FLOW WILL CONTINUE FRIDAY NIGHT INTO
SUNDAY MORNING. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT.
WINDS NO HIGHER THAN 10-15 KNOTS AND SEAS NO HIGHER THAN 3-5
FEET. A COLD FRONT ENTERS THE REGION FROM THE NORTH AND THE
PRESSURE GRADIENT TIGHTENS SATURDAY NIGHT. WINDS WILL BE 10-15
KNOTS THROUGHOUT...EXCEPT FOR OREGON INLET TO OCRACOKE WITH 15-20
KNOTS. THE FRONT WILL DROP QUICKLY THROUGH THE MARINE AREA DURING
THE DAY SUNDAY WITH A QUICK VEERING TO NORTH AS IT PASSES. EXPECT
THIS WIND SHIFT TO OCCUR AROUND MIDDAY IN THE NORTHERN WATERS AND
LATE IN THE AFTERNOON IN THE SOUTHERN WATERS. SOME STRONG STORMS
COULD DEVELOP ALONG AND AHEAD OF THE FRONT ON SUNDAY WITH GUSTY
SURFACE WINDS UP TO 50 KNOTS. LIGHT NORTH TO NORTHEAST FLOW
FORECAST SUNDAY NIGHT INTO MONDAY WITH HIGH PRESSURE TO THE NORTH
AND A LOOSE PRESSURE GRADIENT. THE HIGH WILL MOVE OFF THE COAST
MONDAY NIGHT WITH A SOUTHERLY FLOW SETTING UP ONCE AGAIN. WINDS
AND SEAS WILL BE VERY LIGHT WITH SPEEDS 5-10 KNOTS AND SEAS 2-4
FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
AMZ156-158.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC/JME
SHORT TERM...BTC
LONG TERM...HSA
AVIATION...JME/HSA
MARINE...CTC/JME/HSA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
320 AM CDT FRI AUG 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI AUG 2 2013
MAIN CONCERNS IN THE SHORT TERM WILL BE EXTENT/PLACEMENT OF SHOWERS
AND THUNDERSTORMS...AS FORECAST MODELS DIFFER ON HOW PRECIPITATION
FIELD WILL PLAY OUT.
CURRENTLY...SURFACE HIGH PRESSURE WAS CENTERED OVER NORTHERN
SASKATCHEWAN WITH THE RIDGE AXIS EXTENDING SOUTHEASTWARD ACROSS
NORTH CENTRAL AND EASTERN NORTH DAKOTA. MEANWHILE LOW PRESSURE WAS
CENTERED OVER WYOMING. AT UPPER LEVELS...A LOW/TROUGH WAS OVER THE
ROCKIES NEAR IDAHO/WESTERN MONTANA WITH SHORTWAVE ENERGY MOVING
THROUGH THE SOUTHWEST FLOW ALOFT OVER CENTRAL/EASTERN MONTANA. A
CLUSTER OF THUNDERSTORMS OVER SOUTHEASTERN MONTANA MOVED INTO
NORTHWESTERN SOUTH DAKOTA AND SOUTHWESTERN NORTH DAKOTA...ASSOCIATED
WITH THE UPPER LEVEL ENERGY IMPULSES. AS THE CONVECTION MOVED
EASTWARD IT ENTERED A MORE STABLE ENVIRONMENT OVER NORTH
DAKOTA...WHERE EFFECTIVE BULK SHEAR WAS LOW AND MOST UNSTABLE CAPE
WAS MINIMAL. THOUGH SHOWERS WERE OCCURRING IN SOUTHWESTERN NORTH
DAKOTA - LIGHTNING ACTIVITY HAD DECREASED GREATLY.
THE SREF SEEMS TO HAVE BEST CAPTURED CURRENT EXTENT OF SHOWERS OVER
THE DAKOTAS. THIS MODEL DEPICTS PRECIPITATION AREA EXPANDING
NORTHWARD AND EASTWARD INTO NORTH DAKOTA...SPREADING AS FAR AS MINOT
AND JAMESTOWN. HOWEVER THIS MODEL IS BULLISH REGARDING THE STRENGTH
OF THE UPPER LEVEL SHORTWAVE IMPULSES OVERCOMING THE LIMITING
FACTORS OF THE UPPER LEVEL RIDGE AND LACK OF ROBUST LOW LEVEL
MOISTURE. THE NAM AND GFS KEEP THE AREA OF PRECIPITATION MORE
CONFINED TO THE SOUTHWEST AND FAR SOUTH CENTRAL...MAINLY SOUTH OF
WILLISTON AND BISMARCK. THE RUC DEPICTS PRECIPITATION REMAINING WEST
AND SOUTH OF THE STATE UNTIL THIS AFTERNOON.
THE UPPER LEVEL SHORTWAVE ENERGY IS MOVING TOWARDS NORTH DAKOTA IN
SOUTHWEST FLOW ALOFT...EMERGING FROM THE AFOREMENTIONED ROCKIES
LOW/TROUGH...AND MOVING INTO THE DOWNSTREAM UPPER RIDGE OVER THE
WESTERN DAKOTAS. A STRONG HUDSON BAY LOW IS EXPECTED TO REMAIN
FAIRLY STATIONARY...KEEPING THE UPPER RIDGE IN PLACE. ALSO A DRY
SURFACE HIGH OVER SOUTH CENTRAL CANADA AND EXTENDING INTO THE
EASTERN DAKOTAS AND MINNESOTA WILL KEEP SURFACE DEWPOINTS IN THE
LOWER 50S AND LIMITING THE AVAILABLE LOW LEVEL MOISTURE.
THUS WILL KEEP HIGHER CHANCES IN THE FAR SOUTHWEST TODAY AND LESSER
CHANCES NORTHEASTWARD. SOME AFTERNOON HEATING MAY INCREASE THE
OVERALL INSTABILITY ACROSS THE REGION...BUT NO SEVERE STORMS ARE
ANTICIPATED IN NORTH DAKOTA. WILL KEEP SOME CHANCES OF
SHOWERS/THUNDER FOR TONIGHT AS WELL...BUT THE UPPER LEVEL RIDGE
BUILDS DURING THE NIGHT AND LESSEN THE CHANCES FOR PRECIPITATION.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI AUG 2 2013
VERY WEAK MID-LEVEL RIDGING NUDGING INTO THE NORTHERN PLAINS IS
PROGGED TO KEEP MOST OF THE REGION DRY SATURDAY. AN APPROACHING
SHORTWAVE WARRANTS MAINTAINING SLIGHT CHANCE POPS IN THE EXTREME
WEST SATURDAY.
THE AFOREMENTIONED SHORTWAVE IS FORECAST TO PUSH ACROSS THE REGION
SATURDAY NIGHT INTO SUNDAY. MAINTAINED HIGH-END CHANCE POPS FOR THIS
PERIOD AS UPPER FORCING APPEARS SUFFICIENT FOR CONVECTIVE
DEVELOPMENT. BOTH THE 00Z GFS/ECWMF PROG INCREASING MUCAPE VALUES
OVER SOUTHWESTERN AND SOUTHCENTRAL NORTH DAKOTA SUNDAY AFTERNOON.
HOWEVER...THE GREATEST MUCAPE VALUES (SOUTHWEST/SOUTHCENTRAL) ARE
DISPLACED FROM THE BEST UPPER LEVEL FORCING (EAST). WILL THEREFORE
KEEP SEVERE MENTION OUT OF THE ZONES AND HWO FOR NOW...BUT WILL
CONTINUE TO MONITOR FUTURE RUNS.
THE PERSISTENT NORTHWESTERLY FLOW ALOFT WILL MAINTAIN SLIGHT CHANCES
FOR PRECIP DAILY THROUGH THE END OF THE PERIOD. THE 00Z GFS/ECMWF
CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL LOW OVER HUDSON
BAY MONDAY DROPPING SOUTH ACROSS SOUTH CANADA AND POSSIBLY INTO THE
FAR NORTH CENTRAL CONUS NEXT WEDNESDAY THROUGH FRIDAY. IF THESE
SOLUTIONS VERIFY...THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL
TEMPERATURES DURING THE LATTER HALF OF NEXT WEEK. THE RAW GFS/ECMWF
MODEL SOLUTIONS PAINT HIGHS IN THE MID 60S (HIGHS IN THE MID 80S ARE
NORMAL FOR EARLY AUGUST) BY THURSDAY AUGUST 8. FOR NOW WILL CONTINUE
TO GO WITH A CONSERVATIVE BLENDED APPROACH AND FORECAST HIGHS IN THE
MID 70S FOR DAY 7 DUE TO THE UNCERTAINTY WITH FORECASTING OUT THAT
FAR IN ADVANCE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1227 AM CDT FRI AUG 2 2013
AT MIDNIGHT CDT...SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED OVER
CENTRAL/EASTERN NORTH DAKOTA WITH LOW PRESSURE IN WYOMING. AN UPPER
LEVEL SHORTWAVE WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORMS OVER
SOUTHEASTERN MONTANA MOVING INTO SOUTHWESTERN NORTH DAKOTA AFT 06Z.
THE THREAT TO KDIK LOOKS TO BE AROUND 09Z WITH INSTABILITY REMAINING
FOR MUCH OF THE DAYTIME HOURS AS UPPER LEVEL IMPULSES SLOWLY MOVE
EAST ACROSS THE STATE. THE FARTHER EAST THE UPPER IMPULSES GO IN
NORTH DAKOTA...THE MORE STABLE THE ATMOSPHERE...THUS DID NOT INCLUDE
ANY MENTION OF SHOWERS OR THUNDER AT KMOT OR KJMS. DID BRING MENTION
OF SHOWERS AT KISN AT 12Z AND AT KBIS AT 14Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JV
LONG TERM...TM
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
350 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE TENNESSEE AND LOWER OHIO VALLEY WILL MOVE
SOUTH TODAY AND ALLOW A TROUGH OF LOW PRESSURE TO DROP SOUTHEAST
ACROSS THE AREA TONIGHT AND EARLY SATURDAY. HIGH PRESSURE WILL
MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
HIGH PRESSURE OVER THE LOWER OHIO AND TENNESSEE VALLEY WILL WEAKEN
TODAY AND ALLOW A COLD FRONT TO DROP ACROSS THE CENTRAL GREAT
LAKES. A SURFACE WAVE WILL DEVELOP ON THE FRONT AND SHOULD BE NEAR
THE THUMB OF MICHIGAN BY EVENING ACCORDING TO THE NAM. THE GFS AND
SREF ARE A BIT WEAKER WITH THIS FEATURE HOWEVER ALL MODELS
INCREASE MOISTURE FROM THE WEST DURING THE LATE MORNING AND
AFTERNOON AHEAD OF THE SYSTEM. RADAR ALREADY SHOWS SHOWERS/TSTMS
ALREADY DEVELOPING INVOF ORD AND HRRR BRINGS PRECIP INTO WESTERN
COUNTIES BY MID/LATE MORNING. INCREASING CAPE SHOWN ON THE NAM
ACCOMPANYING THE MOISTURE SO WOULD EXPECT INCREASING CHANCES FOR
THUNDERSTORMS FROM THE WEST THROUGH THE MID/LATE MORNING AND INTO
THE AFTERNOON. HIGHS GENERALLY 76 TO 81.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
THIS EVENING AND OVERNIGHT MODELS SHOW A SHORT WAVE DROPPING
ACROSS THE CENTRAL GREAT LAKES AS THE COLD FRONT DROPS INTO THE
NRN COUNTIES. WITH INGREDIENTS IN PLACE...EXPECTING A DECENT CHANCE
OF PRECIP ACROSS THE AREA THROUGH THE NIGHT AND INTO SATURDAY
MORNING BEFORE TAPERING FROM THE NORTH DURING THE DAY SATURDAY AS
DRY AIR AND HIGH PRESSURE BUILD FROM THE NORTH. FOLLOWED SREF
TIMING WITH A COMPROMISE IN POPS LEAVING LIKELY FOR THE CATEGORY
THROUGH THE NIGHT. WILL BEGIN SATURDAY WITH CHANCE POPS NORTH AND
LIKELY SOUTH AS MODELS START THE DAY WITH DEEP MOISTURE STILL
ACROSS MUCH OF THE AREA AND THE FRONT ALSO STILL ACROSS THE CWA.
SATURDAY NIGHT MOISTURE WILL BE ALL BUT OUT OF THE AREA. WILL HAVE
A SLIGHT CHANCE POP EAST JUST TO COVER ANY LEFTOVER SHOWERS BUT
FOR THE MOST PART EXPECT DRY CONDITIONS. SUNDAY THROUGH MONDAY
EXPECT DRY CONDITIONS WITH HIGH PRESSURE ACROSS THE AREA. MONDAY
NIGHT DID BRING SLIGHT CHANCE POPS BACK TO THE WEST DURING THE
NIGHT AS THE SURFACE HIGH DRIFTS EAST AND THE GFS SHOWS INCREASING
MOISTURE IN A GENERAL OVERRUNNING PATTERN. STILL HOWEVER WOULD
EXPECT MOST WILL REMAIN DRY AS BEST OVERRUNNING/LIFT AND
INSTABILITY WILL REMAIN WELL WEST OF THE AREA. HIGHS GENERALLY
UNREMARKABLE FOR THIS TIME OF YEAR...MOSTLY REACHING 75 TO
80...COOLEST EAST AND WARMEST WEST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HEIGHTS WILL REBOUND SOME ON TUESDAY AS ONE UPPER LOW CURLS
NORTHEAST TOWARDS NOVA SCOTIA AND A SECONDARY ONE DEVELOPS OVER
MANITOBA. THE FLOW ALOFT ACTUALLY BECOMES NEARLY ZONAL ON THE
SOUTHERN PERIPHERY OF THE BROAD UPPER TROUGH EXTENDING ACROSS
CENTRAL AND EASTERN CANADA. TIMING CHANCES OF PRECIPITATION WILL BE
CHALLENGING IN THE EXTENDED AS MODELS STRUGGLE TO RESOLVE SHORTWAVES
MOVING THROUGH THE FLOW ALOFT. TUESDAY LOOKS LIKE A MOSTLY DRY DAY
AS HIGH PRESSURE EXITING TO THE EAST REMAINS IN CONTROL WITH A
FAIRLY DRY AIRMASS. ALTHOUGH MODELS HAVE SHOWN POOR RUN TO RUN
CONTINUITY IN THIS PATTERN...CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE ON WEDNESDAY AS A WARM FRONT IS PULLED OVER THE REGION
AHEAD THE NEXT COLD FRONT THAT PUSHES SOUTH ACROSS THE AREA
THURSDAY. MODELS ARE STARTING TO HINT AT SOME FAIRLY STRONG WARM
ADVECTION AHEAD OF THE FRONT AND TEMPERATURES ON WEDNESDAY(POSSIBLY
LINGERING INTO THURSDAY) MAY NEED TO BE RAISED SEVERAL DEGREES INTO
THE MID 80S. HAVE TRENDED HIGHS UP BUT KEPT THE FORECAST ON THE COOL
SIDE OF MEX GUIDANCE GIVEN THE UNCERTAINTY IN PATTERN EVOLUTION AND
NORTHERN REACH OF THAT WARM FRONT.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
CLEAR SKIES ARE IN PLACE OVER THE REGION TONIGHT WITH SOME BR
DEVELOPING MAINLY NE OHIO BETWEEN 10-13Z. SOME SITES WILL SEE MVFR
AND POSSIBLY IFR VISIBILITIES FOR A FEW HOURS.
MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE AHEAD OF
A FRONT LATE THIS AFTERNOON INTO TONIGHT. HAVE INCLUDED A PROB GROUP
FOR MOST LOCATIONS...STARTING IN TOL/FDY AT 21Z AND CLE AT 00Z.
THUNDERSTORMS WILL CONTAIN LOCALLY HEAVY RAIN AND SOME STRONGER WIND
GUSTS WITH CONDITIONS DROPPING TO IFR IN THE HEAVIER SHOWERS AT
TIMES. WINDS WILL ALSO BE RATHER BREEZY DURING THE AFTERNOON AS A
35-40 KNOT LOW LEVEL JET DEVELOPS ALOFT. SURFACE WINDS MAY GUST
TO 25-30 KNOTS DURING THE LATE AFTERNOON...WITH THE STRONGEST
WINDS EXPECTED AT TOL/FDY/CLE.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH
SHOWERS/STORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE FROM WEST TO EAST ACROSS THE LAKE
INTO THIS EVENING AHEAD OF THE NEXT FRONT THAT WILL PUSH SOUTH
ACROSS THE LAKE OVERNIGHT. WINDS WILL APPROACH 20 KNOTS ON THE EAST
HALF OF THE LAKE FOR A FEW HOURS WITH WAVES APPROACHING 4 FEET.
ALTHOUGH SOMEWHAT MARGINAL...A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR A PERIOD OF TIME ON THE EAST END OF THE LAKE TONIGHT.
WINDS WILL VEER AROUND TO THE NORTHWEST ON SATURDAY BEHIND THE FRONT
BUT WILL GENERALLY BE AROUND 10 KNOTS AS THE TROUGH LINGERS IN THE
VICINITY OF THE LAKE...INCREASING ON SUNDAY AS A SECONDARY COLD
FRONT PUSHES SOUTH. HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE
GREAT LAKES FROM MONDAY INTO TUESDAY WITH IMPROVING MARINE
CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS TULSA OK
331 AM CDT FRI AUG 2 2013
.DISCUSSION...
THUNDERSTORM COMPLEX MOVING INTO SOUTHEAST KANSAS LOOKS TO
AFFECT PORTIONS OF NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS
THIS MORNING. THE LAST FEW RUNS OF THE HRRR HAVE BEEN CONSISTENT
WITH BRINGING THIS COMPLEX THROUGH NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS BEFORE IT DISSIPATES. BEST CHANCES OF SHOWERS AND THUNDERSTORMS
THIS MORNING WILL BE ALONG AND NORTH OF HIGHWAY 412. ADDITIONAL SHOWERS
AND THUNDERSTORMS MAY DEVELOP LATER THIS AFTERNOON AND EVENING ALONG
ANY LEFTOVER OUTFLOW BOUNDARIES. WILL NOT ISSUE ANY HEAT HEADLINES TODAY
WITH ONLY A FEW LOCATIONS HITTING CRITERIA THIS AFTERNOON.
THUNDERSTORM COMPLEXES MOVING OUT OF KANSAS WILL AFFECT PORTIONS OF
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS FOR THE NEXT FEW NIGHTS AS
THE AREA REMAINS ON THE EDGE OF THE NORTHWESTERLY FLOW ALOFT. THIS
CHANGES SOMEWHAT TOWARDS MID-WEEK AS THE MID-LEVEL HIGH BUILDS OVER
THE AREA. A FRONTAL BOUNDARY MAKES A RUN INTO THE AREA THURSDAY
INTO FRIDAY AS A MID-LEVEL SHORTWAVE SWEEPS ACROSS THE GREAT LAKES
KEEPING CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 97 78 97 75 / 20 20 20 20
FSM 96 76 98 75 / 10 30 20 20
MLC 98 77 99 75 / 10 20 20 20
BVO 94 76 95 72 / 40 30 20 30
FYV 91 75 92 72 / 20 40 20 20
BYV 88 73 91 72 / 40 50 30 20
MKO 95 75 97 73 / 10 30 20 20
MIO 90 75 93 73 / 50 40 20 30
F10 97 78 98 74 / 10 20 20 20
HHW 98 76 100 75 / 0 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...30
LONG TERM....10
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
203 AM EDT FRI AUG 2 2013
.SYNOPSIS...
THE COLD FRONT HAS PUSHED THROUGH MOST OF THE AREA...BUT THE
UPPER TROUGH IS APPROACHING FROM THE WEST. IT SHOULD PASS
OVERHEAD TONIGHT...LEAVING GENERALLY ZONAL FLOW ALOFT FOR THE
NEXT FEW DAYS. A SECONDARY COLD FRONT WILL MOVE THROUGH THE REGION
ON SATURDAY AND BRING ANOTHER PERIOD OF SHOWERS TO THE AREA.
UNSEASONABLY COOL AND DRY WEATHER SHOULD THEN PREVAIL FROM SUNDAY
INTO MONDAY AS A CANADIAN HIGH PRESSURE SYSTEM MIGRATES SOUTHEAST
FROM THE NORTHERN PLAINS INTO THE MID-ATLANTIC STATES.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
WATER VAPOR IMAGERY AT 05Z SHOWS POTENT SHORTWAVE TROF LIFTING
THRU NE PA AND EXITING THE AREA. IN IT/S WAKE...MCLEAR SKIES AND
LIGHT WINDS ARE ALREADY RESULTING IN AREAS OF RADIATION FOG ACROSS
THE W MTNS AND ALSO ACROSS THE SUSQ VALLEY...WHERE GROUND IS WET
FROM YESTERDAY/S RAINFALL. LATEST HRRR SUPPORTS THIS IDEA OF THE
BIGGEST FOG CONCERN ACROSS THE W MTNS AND SUSQ VALLEY THRU ARND
12Z.
TEMPS ON TRACK TO BOTTOM OUT FROM ARND 50F OVR THE NW MTNS...TO
THE L/M60S ACROSS THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/...
SFC HIGH AND ASSOCIATED AREA OF LOW PWATS CENTERED OVER THE
CENTRAL APPALACHIANS SHOULD PROVIDE FAIR AND COOL WX FOR MOST OF
CENTRAL PA TODAY. A FAST-MOVING SHORTWAVE...ENTERING THE W GRT
LKS AT 06Z...WILL SWEEP THRU CENTRAL PA DURING THE LATE AM AND
AFTN HOURS...AS IT ROUNDS BASE OF UPPER LVL TROF. LATEST MDL
GUIDANCE SUGGESTS THERE WILL BE JUST ENOUGH MOISTURE AHEAD OF THIS
FEATURE TO SQUEEZE OUT A FEW ISOLD SHOWERS ACROSS THE AREA. TIMING
WOULD BE LATE AM ACROSS THE W MTNS AND DURING THE AFTN ACROSS THE
EASTERN COUNTIES.
AS UPSTREAM SATL IMAGERY WOULD SUGGEST...EXPECT SUNSHINE TO
PREDOMINATE ACROSS MOST OF CENTRAL PA TODAY. POCKET OF COLD AIR
ALOFT TRACKING ACROSS UPSTATE NY MAY RESULT IN A MORE EVEN MIX OF
SUN AND CU ACROSS THE NORTH...WHILE MAINLY SUNNY SKIES PREVAIL
ELSEWHERE. GEFS MEAN 8H TEMPS ARND 13C ARE A BIT BELOW NORMAL FOR
EARLY AUGUST AND SHOULD TRANSLATE TO HIGH TEMPS FROM THE L70S OVR
THE HIGHEST TERRAIN OF THE ALLEGHENIES...TO THE L80S ACROSS THE
SUSQ VALLEY.
ADDITIONAL SHORTWAVE ENERGY AND ASSOC WEAK SFC LOW WILL APPROACH
FROM THE WEST FRIDAY NIGHT. WAA AHEAD OF THIS FEATURE WILL LIKELY
SPREAD CLOUDS AND SHOWERS INTO CENTRAL PA FRIDAY NIGHT. A BLEND OF
LATEST OPER AND ENSEMBLE MDL DATA SUGGESTS THE HIGHEST CHC OF RAIN
FRI NIGHT WILL BE NORTH OF THE I 80 CORRIDOR.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THE MODELS SHOW A COMPLETE CHANGE AS THEY TAKE INTO ACCOUNT OF
MONSOONAL MOISTURE IN COORDINATION WITH THE WESTERLY FLOW. THOSE
INGREDIENTS SHOULD WORK IN CONJUNCTION WITH A SHORT WAVE
TRAVERSING THROUGH THE AREA WILL ALLOW FOR A GOOD CHC OF RAIN FOR
MUCH OF CENTRAL PA SATURDAY. INCREASING SPEED WIND SHEAR AHEAD OF
THIS SYSTEM COULD POTENTIALLY RESULT IN A SVR WX THREAT BY SAT
AFTN. MUCH UNCERTAINTY REMAINS WITH REGARD TO THE EXACT TRACK OF
SFC LOW AND AMT OF CLOUD COVER. THE STRONGEST REA OF MOISTURE IS
IN SOUTHERN PA WHICH COULD BECOME MODERATELY UNSTABLE IN SOME MDL
SCENARIOS...SO THIS AREA WILL HAVE TO BE WATCHED.
FAIRLY WIDE CONSENSUS AMONG MED RANGE GUIDANCE FOR ANOTHER STRETCH OF
COOL/DRY WX SUNDAY INTO EARLY NEXT WEEK...AS COLD FRONT PRESSES
SOUTH OF PA AND COOL...CANADIAN HIGH PRES BUILDS SE ACROSS THE AREA.
00Z GEFS 8H TEMPS REMAIN BLW NORMAL SUN-MON WHEN DAYTIME MAXES WILL
LIKELY BE 5-10F BLW NORMAL. EC ENSEMBLE MEAN SHOWS AXIS OF UPPER
TROUGH SHIFTING FROM THE NORTHEAST CONUS TO THE MIDWEST BY THE
MIDDLE OF NEXT WEEK...INDICATING SLIGHTLY WARMER...MORE HUMID AIR
MAY RETURN.
THE NEXT CHANCE FOR PRECIPITATION WILL BE FROM A ANOTHER TROUGH
WITH NORTHWESTERLY FLOW NEXT TUESDAY THROUGH WEDNESDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
STORMS NOW OUT OF THE AREA.
REAL STRONG STORMS STAYED JUST TO THE SOUTH OF OUR AREA.
ONE STORM HAD A HOOK ECHO...AN INTERESTING EVENING.
ANYWAY...MAIN CONCERN OVERNIGHT WILL BE THE POTENTIAL
FOR FOG FORMATION. DEWPOINT GRADIENT ACROSS THE AREA.
HARD TO SEE COLD FRONT MOVING MUCH FURTHER SE.
WAS CONCERN ABOUT THE FAR FAR NW AREAS LIKE BFD LATER
TONIGHT...AS MORE CONVECTION OVER OH WITH RATHER STRONG UPPER
LVL TROUGH WAS MOVING EASTWARD. HOWEVER...TIME OF DAY...AND
LACK OF SFC CONVERGENCE AND MOISTURE TO THE WEST AND NORTH...
HAS RESULTED IN STORMS FALLING APART.
MOST OF FRIDAY LOOKS OK...BUT AN ISOLATED SHOWER POSSIBLE
ACROSS N PA...GIVEN COLD AIR ALOFT.
MORE IN THE WAY OF WIDESPREAD SHOWERS AND THUNDERSTORMS
LIKELY LATE FRIDAY NIGHT INTO EARLY SUNDAY MORNING...AS
STRONG DYNAMICS COMBINE WITH WARM ADVECTION TO PRODUCE
ADVERSE WEATHER CONDITIONS. WIDESPREAD MVFR AND EVEN IFR
CONDITIONS POSSIBLE AT TIMES.
IMPROVING CONDITIONS FOR LATER SUNDAY...AS HIGH PRESSURE
BUILDS INTO THE AREA.
OUTLOOK...
SAT...MVFR/IFR WITH SHOWERS AND STORMS.
SUN...MVFR AND IFR EARLY WITH SHOWERS...THEN
IMPROVING CONDITIONS.
MON-TUE...VFR. NO SIG WX.
&&
.EQUIPMENT...
KCCX WIDEBAND COMMS HAS FAILED. VZ TECHS TROUBLESHOOTING.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/DEVOIR
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/CERU
AVIATION...MARTIN
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
301 AM CDT FRI AUG 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CDT FRI AUG 2 2013
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHS OVER THE PACIFIC NORTHWEST AS WELL AS FROM
HUDSON BAY INTO THE GREAT LAKES...WITH RIDGING IN-BETWEEN ALONG THE
LEE OF THE ROCKIES. THE FORECAST AREA REMAINS IN NORTHWEST FLOW EAST
OF THE RIDGING. WITHIN THIS FLOW...SHORTWAVES OF NOTE WERE OVER LAKE
WINNIPEG...NORTHERN WI AND SOUTHEAST WI. THE SOUTHEAST WI SHORTWAVE
IN CONJUNCTION WITH A SURGE OF WARM ADVECTION SEEN ON 850MB VAD WIND
PROFILE DATA HELPED BRING A BAND OF SCATTERED SHOWERS AND STORMS
ACROSS THE FORECAST AREA LAST EVENING...A FEW WHICH WERE STRONG TO
SEVERE. TO THE NORTH...A COLD POOL ACCOMPANYING THE NORTHERN WI
SHORTWAVE AS WELL AS MOISTURE SEEN ON THE 00Z INL SOUNDING BROUGHT
SHOWERS AND A FEW STORMS THROUGH NORTHERN WI OVERNIGHT. WARM
ADVECTION WELL SOUTH OF THIS SHORTWAVE AND SOME LINGERING WEAK
INSTABILITY / MUCAPE LESS THAN 500 J/KG /HAS HELPED PRODUCED SHOWERS
AND SOME STORMS SOUTH OF I-90 IN THE FORECAST AREA. SO FAR
EVERYTHING IS QUIET WITH THE LAKE WINNIPEG SHORTWAVE. ON
SATELLITE...MOSTLY CLEAR SKIES ENCOMPASSED MUCH OF THE EASTERN
DAKOTAS INTO MN...THANKS TO DRYING SEEN ON THE 00Z MPX... BIS AND
ABR SOUNDINGS. THIS DRYING IS ALSO BEHIND A SURFACE COLD FRONT WHICH
CAN BE SEEN ON MPX RADAR DROPPING THROUGH MINNEAPOLIS AT THIS TIME.
850MB TEMPS BEHIND THE COLD FRONT ARE NOT MUCH COOLER THAN THOSE
AHEAD OF IT...THOUGH...WITH READINGS GENERALLY 13-15C PER 00Z
SOUNDING DATA.
SYNOPTIC OVERVIEW...
THE NORTHWEST FLOW PATTERN CONTINUES TO PERSIST THROUGH THE SHORT
TERM PERIOD. THE SHORTWAVES OVER NORTHERN WI AS WELL AS OVER LAKE
WINNIPEG ARE PROGGED TO STAY OFF TO OUR NORTH AND EAST.
MEANWHILE...NUMEROUS WEAK SHORTWAVES ARE SUGGESTED TO COME OUT OF
THE PACIFIC NORTHWEST TROUGH AND DROP THROUGH THE FORECAST AREA
TONIGHT.
DETAILS...
THE COLD FRONT LURKING JUST OFF TO THE NORTHWEST AT 08Z LOOKS TO
PUSH THROUGH THE FORECAST AREA DURING THE MORNING HOURS. ONCE IT
PASSES...THE CONCERN FOR PRECIPITATION ENDS AS THE DRIER AIR OVER
THE DAKOTAS AND MN FLOWS IN. DESPITE THE SHORTWAVES CROSSING THE
FORECAST AREA TONIGHT...WHICH APPEAR LIKELY TO BRING SOME MID/HIGH
CLOUDS THROUGH...SOUNDINGS DEPICT PLENTY OF DRY AIR BELOW 700MB TO
PREVENT ANY PRECIPITATION. 02.00Z GFS/NAM/ECMWF/REGIONAL CANADIAN
ARE ALL DRY...FURTHER INCREASING CONFIDENCE FOR A DRY FORECAST
TONIGHT. 850MB TEMPS IN THE 12-14C RANGE PLUS A MIX OF SUN THROUGH
PASSING MID/HIGH CLOUDS SHOULD ALLOW TEMPERATURES TO CLIMB WELL INTO
THE 70S. A FEW LOW 80S ARE POSSIBLE. IT APPEARS THE MID AND HIGH
CLOUDS SHOULD GRADUALLY CLEAR OUT TONIGHT AND WITH LIGHT WINDS AND
DRIER AIR...SOME OF THE TYPICAL COLD SPOTS COULD DROP INTO THE LOW
50S. OTHERWISE...MID/UPPER 50S APPEAR LIKELY. SOME VALLEY FOG MAY
OCCUR...PARTICULARLY IN THE SMALLER TRIBUTARIES TO THE MISSISSIPPI
RIVER. THERE MAY BE TOO MUCH EVENING CLOUD COVER...AFTERNOON
DEWPOINT MIXING/DRYING TODAY AND LATE DIMINISHING IN WIND TO ALLOW
FOG IN THE MISSISSIPPI RIVER CHANNEL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CDT FRI AUG 2 2013
SYNOPTIC OVERVIEW...
02.00Z ECMWF/GFS/CANADIAN CONTINUE THE NORTHWEST FLOW PATTERN OVER
THE FORECAST AREA THROUGH THE WEEKEND AS TROUGHING REMAINS IN PLACE
OVER SOUTHEAST CANADA INTO THE GREAT LAKES. THERE ARE NOW TRENDS FOR
THE UPPER FLOW OVER THE NORTHERN TIER OF THE U.S. TO START TURNING
MORE ZONAL MONDAY AND TUESDAY...IN RESPONSE TO WHAT BASICALLY COULD
BE CONSIDERED A POLAR VORTEX DROPPING OUT OF HUDSON BAY INTO THE
LAKE WINNIPEG REGION. EVOLUTION AND TRACK OF THE POLAR VORTEX AFTER
TUESDAY IS A LITTLE MORE UNCERTAIN...WITH THE 02.00Z CANADIAN
CARVING OUT MUCH MORE OF A TROUGH ACROSS THE WESTERN GREAT LAKES
COMPARED TO THE 02.00Z ECMWF/GFS WHICH ARE FLATTER WITH THE FLOW.
DETAILS...
FOR THE WEEKEND...HIGH PRESSURE CURRENTLY CENTERED IN NORTHERN
SASKATCHEWAN LOOKS TO DROP SOUTHEAST INTO THE FORECAST AREA ON
SUNDAY...FOLLOWING THE NORTHWEST FLOW PATTERN ALOFT. DRY AIR
ACCOMPANYING THE SURFACE HIGH WILL BE ENOUGH TO KEEP THE WEEKEND
DRY. MAY SEE SOME DIURNAL CUMULUS GROWTH BUT OTHERWISE MOSTLY CLEAR
SKIES ARE LIKELY TO PREVAIL. 850MB TEMPS ARE PROGGED 10-12C ON
SATURDAY AND 8-11C ON SUNDAY...ABOUT 1-1.5 STANDARD DEVIATIONS ABOVE
NORMAL. STILL WITH THE SUN WE SHOULD BE ABLE TO HOLD HIGH TEMPS IN
THE 70S. SATURDAY NIGHT LIKELY TO BE COOL WITH HIGH PRESSURE AND DRY
AIR IN PLACE. LEANED TOWARDS THE COOLER END OF GUIDANCE WHICH ALLOWS
FOR 40S IN SOME OF THE TYPICAL COLD SPOTS OF WI. VALLEY FOG LIKELY
SATURDAY NIGHT IN THE TRIBUTARIES AND POSSIBLY THE MISSISSIPPI
CHANNEL TOO.
CONCERN FOR PRECIPITATION BEGINS TO INCREASE FOR MONDAY AND TUESDAY
WITH THE UPPER FLOW TURNING MORE ZONAL. 02.00Z ECMWF/GFS/CANADIAN
ALL SHOW THE SURFACE HIGH DRIFTING OFF TO THE EAST DURING THIS
PERIOD AS A COLD FRONT APPROACHES THE AREA FROM THE WEST. STILL
TIMING DIFFERENCES WITH THE FRONTAL PASSAGE...BUT CURRENT CONSENSUS
WOULD PUT IT COMING THROUGH SOMETIME LATE TUESDAY. 850MB MOISTURE
TRANSPORT STAYS WEST OF THE AREA SUNDAY NIGHT AND MONDAY...WHICH
SHOULD KEEP PRECIPITATION CHANCES OFF TO THE WEST. PERHAPS SOMETHING
COULD DROP INTO THE AREA ON MONDAY...PER 02.00Z GFS...BUT
CONFIDENCE IS LOW. BETTER SHOT FOR PRECIPITATION COMES MONDAY NIGHT
AS THE 850MB MOISTURE TRANSPORT AND HIGHER ELEVATED CAPE VALUES COME
INTO THE FORECAST AREA. PRECIPITATION CHANCES CONTINUE THROUGH
TUESDAY NIGHT WITH THE FRONTAL PASSAGE. THESE MAY NEED TO BE
INCREASED AS THE FRONTAL TIMING BECOMES MORE REFINED. WITH THE LOW
LEVEL WARM ADVECTION PATTERN IN PLACE MONDAY AND TUESDAY...850MB
TEMPS REBOUND TO 12-14C ON MONDAY AND PERHAPS AS HIGH AS 16-20C ON
TUESDAY. DEPENDING ON AMOUNT OF SUN ON TUESDAY...WE COULD SEE HIGH
TEMPS GO ABOVE NORMAL WITH READINGS IN THE MID TO UPPER 80S.
HOWEVER...GIVEN THE PRECIPITATION CONCERN...HAVE FOLLOWED THE
CONSENSUS HIGHS OF MID 70S ON MONDAY AND 75-80 ON TUESDAY.
FOR WEDNESDAY AND THURSDAY...ANOTHER SURGE OF DRIER AND COOLER AIR
APPEARS SLATED TO COME INTO THE AREA DURING THIS PERIOD...IN THE
WAKE OF TUESDAY/TUESDAY NIGHTS FRONTAL PASSAGE. STILL...WITH
CONCERNS ON FRONTAL TIMING AND BOTH THE 02.00Z ECMWF/CANADIAN
LINGERING SOME PRECIPITATION BACK EVEN BEHIND THE FRONT ON
WEDNESDAY...MAINTAINED 20-30 PERCENT CHANCES. ALSO KEPT SOME 20
PERCENT CHANCES NORTH OF I-90 ON THURSDAY WITH INDICATIONS OF COLDER
AIR ALOFT...BEING CLOSER TO THE TROUGHING UP TO THE NORTH. HIGHS ON
WEDNESDAY SHOULD STILL CLIMB INTO THE MID TO UPPER 70S GIVEN 12-14C
850MB TEMPS...BUT PERHAPS ONLY THE LOW TO MID 70S ON THURSDAY AS
SOME COOLER AIR FLOWS IN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1147 PM CDT THU AUG 1 2013
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. A FRONT WILL MOVE
THROUGH THE AIRFIELDS EARLY THIS MORNING AND CLEAR ANY SHOWER
ACTIVITY TO THE SOUTH. THERE IS A CHANCE FOR VALLEY FOG BOTH
SATURDAY AND SUNDAY MORNINGS AT KLSE. STAY TUNED FOR THOSE
DETAILS IN FUTURE FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1045 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A SERIES OF WEAK UPPER AIR DISTURBANCES WILL PASS MAINLY NORTH OF
THE AREA THROUGH SATURDAY. CANADIAN HIGH PRESSURE FROM THE GREAT
LAKES ON SUNDAY BUILDS INTO THE REGION THROUGH TUESDAY. THE HIGH
MOVES OFFSHORE TUESDAY NIGHT AS A FRONTAL SYSTEM APPROACHES FROM
THE WEST. THE FRONTAL SYSTEM WILL AFFECT THE AREA WEDNESDAY AND
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...MADE SOME MINOR CHANGES TO ACCOUNT FOR CURRENT
TRENDS IN SKY. BASICALLY EXPECTING KC INTO THE MID AFTN UNTIL
SHORTWAVE APPROACHES NORTHERN ZONES LATE THIS AFTERNOON INTO
EARLY THIS EVENING. CONVERTED THE PCPN TO SLIGHT CHANCE FROM
COVERAGE AS NOT CONFIDENT THAT CONVECTION WILL FORM/REACH OUR FCST
AREA. DID INCLUDE TSTMS THOUGH BASED ON WEAK INSTABILITY OF A FEW
HUNDRED JOULES SEEN IN RUC FCST SOUNDINGS.
&&
.SHORT TERM /SATURDAY/...
10 AM UPDATE...LOTS OF UNCERTAINTY AS TO IF IT WILL RAIN OR NOT AT
ALL ON SATURDAY BASED ON THE LATEST NWP. IF IT DOES...THERE IS
ALSO UNCERTAIN IF IT`S IN THE MORNING (LIKE SEEN IN 12Z NAM AND
00Z ECMWF) OR AFTN (06Z GFS). THUS HAVE KEPT FORECAST AS IS FOR NOW.
WILL BE LOOKING AT THIS MORE FOR THE NEXT UPDATE.
OTHERWISE...HIGH PRES CONTINUES TO BUILD EAST ON SATURDAY. TEMPS WILL BE
SLIGHTLY COOLER WITH HIGHS IN THE UPPER 70S TO AROUND 80.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A WEAK COLD FRONT WILL MOVE SOUTH OF THE REGION SATURDAY NIGHT AS
A SHORTWAVE ROTATES THROUGH THE UPPER TROUGH ACROSS EASTERN CANADA
AND INTO THE NORTHEASTERN UNITED STATES. AN IMPULSE WILL ALSO BE
MOVING AROUND THE BASE OF THE TROUGH FROM THE MIDWEST SATURDAY
NIGHT. SO WILL HAVE CHANCE TO SLIGHT CHANCE POPS SATURDAY NIGHT.
THE UPPER TROUGH REMAINS INTO THE BEGINNING OF NEXT WEEK...AS FLOW
BECOME NEARLY ZONAL. WITH THE NEARLY STATIONARY UPPER TROUGH AND
THE NEXT SHORTWAVE SLOWER TO ROTATE INTO THE REGION AS THE UPPER
LOW CLOSES OFF HAVE DELAYED THE ONSET OF THE NEXT CHANCE OF
PRECIPITATION UNTIL LATE TUESDAY NIGHT...WITH CHANCE POPS DELAYED
UNTIL WEDNESDAY. THE NEW ECMWF 00Z/02 INDICATING THAT
PRECIPITATION MAY HOLD OFF UNTIL LATER WEDNESDAY. WITH A BLOCKING
PATTERN SETTING UP...THEN UPPER TROUGH WILL REMAIN THROUGH THE
UPCOMING WEEK AND THE ASSOCIATED SURFACE FRONTAL SYSTEM WILL BE
SLOW TO MOVE THROUGH. SO WILL HAVE CHANCES OF PRECIPITATION FOR
WEDNESDAY AND THURSDAY...AND CONTINUING INTO FRIDAY.
WITH A WEST TO NORTHWEST FLOW INTO TUESDAY AND THEN CLOUDS AND
PRECIPITATION WEDNESDAY AND THURSDAY WILL BE A RATHER COOL PERIOD.
SUNDAY AND MONDAY TEMPERATURES WERE A BLEND OF THE ECMWF AND MEX
GUIDANCE...AND THEN LEANED TOWARD THE WPC GUIDANCE...SUNDAY NIGHT
THROUGH THURSDAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS FOR TODAY WITH WEAK HIGH PRESSURE BUILDING IN THE
WAKE OF THE COLD FRONT.
MOD CONFIDENCE ON WINDS TODAY...SHIFTING TO A W FLOW EARLY AFTN AND
BECOMING SW BY LATE AFTN. WINDS INCREASING TO AROUND 10 KTS FOR
THE AFTN. PSBL GUSTS BETWEEN 15 AND 20 KTS MAINLY AT NYC AND LI
SITES AFTER 15Z.
FEW TO SCT MID TO HIGH LEVEL CLOUDS TODAY...WITH INCREASING
COVERAGE TONIGHT. LOW CHANCE OF SHRA/TSRA AT KSWF FOR LATE TODAY
INTO EVENING SO WILL NOT INCLUDE AT THIS TIME.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE COULD BE +/- 2 HOURS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE COULD BE +/- 2 HOURS.
KLGA FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE MAY BE 1-2 HRS LATER THAN IN TAF.
KTEB FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE COULD BE +/- 2 HOURS.
KHPN FCSTER COMMENTS: WIND SHIFT TO LEFT OF 300 TRUE MAY BE 1-2
HRS LATER THAN IN TAF. OCNL GUSTS 15-20 KT PSBL THIS AFTN.
KISP FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE COULD BE +/- 2 HOURS.
.OUTLOOK FOR 12Z SAT THROUGH TUE...
.SAT-SAT NIGHT...MAINLY VFR. SUB VFR IS POSSIBLE IN SCATTERED LATE
DAY AND EVENING SHOWERS/TSTMS.
.SUN-TUE...VFR.
&&
.MARINE...
WITH A WEAK SURFACE TROUGH DEVELOPING THIS AFTERNOON THE WIND
SHIFTS BACK TO SOUTHWEST AND SEAS OF 3 TO 4 FT ON THE OCEAN
WATERS.
A FEW GUSTS TO 20 KT ARE POSSIBLE THIS AFTERNOON...OTHERWISE...TRANQUIL
CONDS ON TAP FOR THE DAY. THIS EVENING...SEAS WILL BUILD TO 5 FT
ON THE EASTERN OCEAN WATERS...SO WILL ISSUE A SCA FOR HAZARDOUS
SEAS FOR TONIGHT. CONDS ON THE EASTERN OCEAN WATERS WILL SUBSIDE
BELOW SCA BY SATURDAY MORNING. SUB-ADVISORY CONDS ON TAP FOR
SATURDAY.
ISOLATED TSTMS ARE POSSIBLE THIS EVENING AS A WEAK SHORTWAVE
SLIDES THROUGH THE REGION. ANOTHER SHORTWAVE WILL BRING SCATTERED
SHOWERS WITH ISOLATED THUNDERSTORMS SATURDAY AFTERNOON.
A WEAK COLD FRONT WILL MOVE SOUTH ACROSS THE FORECAST WATERS
SATURDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE WEST SUNDAY
THROUGH TUESDAY AND MOVES EAST OF THE FORECAST WATERS TUESDAY
NIGHT AS A FRONTAL SYSTEM APPROACHES FROM THE WEST. SEAS AND WIND
ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS SATURDAY
NIGHT THROUGH TUESDAY NIGHT.
&&
.HYDROLOGY...
SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS ARE POSSIBLE ONCE
AGAIN ON SATURDAY.
THE NEXT CHANCE FOR ORGANIZED WIDESPREAD RAINFALL WILL BE
WEDNESDAY AND THURSDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 PM THIS
EVENING TO 6 AM EDT SATURDAY FOR ANZ350.
&&
$$
SYNOPSIS...MPS/MET
NEAR TERM...MPS/TONGUE
SHORT TERM...MPS/TONGUE
LONG TERM...MET
AVIATION...SEARS/JM
MARINE...MPS/MET
HYDROLOGY...MPS
AREA FORECAST DISCUSSION...UPDATED AVIATION AND MARINE DISCUSSION
NWS MELBOURNE FL
1015 AM EDT FRI AUG 2 2013
.DISCUSSION...
CURRENT-THIS AFTERNOON...
PRIMARY CONCERN WILL BE THE TROUGH OF LOW PRESSURE BETWEEN THE
NORTHERN BAHAMA ISLANDS AND THE MARTIN AND SAINT LUCIE COUNTY COAST
AS IT INITIALLY MOVES SLOWLY NORTH NORTHWEST TODAY THEN NORTH
NORTHEAST AND AWAY FROM THE FLORIDA EAST COAST OVERNIGHT. RADAR WAS
DETECTING MOST OF THE SHOWERS AND ANY STORMS EAST OF THE TROUGH BUT
WRAP AROUND SHOWERS WILL PERIODICALLY IMPACT THE EAST CENTRAL
FLORIDA COAST THE REST OF TODAY. VISIBLE SATELLITE LOOP IS SHOWING
MOSTLY CLEAR SKIES OVER MOST OF EAST CENTRAL THAT IS AWAY FROM THE
COAST. WEAK PRESSURE GRADIENT AND FULL SUN WILL ALLOW FOR BOTH THE
EAST AND WEST COAST SEA BREEZES TO FORM AND PUSH INLAND THIS
AFTERNOON. LOCAL WRF AND RUC MODELS ARE TRYING TO SHOW LATE
AFTERNOON EAST AND WEST COAST SEA BREEZE COLLISIONS OVER LAKE COUNTY.
THE CURRENT 30 POP AT THE COAST INCREASING TO AROUND 50 OVER LAKE
COUNTY STILL LOOKS REASONABLE BASED ON SEA BREEZE COLLISIONS.
MOST SIGNIFICANT CHANGES TO THE AFTERNOON FORECAST WILL BE THE WINDS.
PREVIOUS DISCUSSION
TODAY...COMPLEX PATTERN EVOLVING ACROSS THE PENINSULA TODAY AS THE
NORTHERN STREAM UPPER LEVEL SHORTWAVE LIFTS OFF TO THE NORTHEAST.
ALSO BECOMING A PLAYER ARE THE RECENTLY REINVIGORATED REMNANTS OF
DORIAN NOW A STRONG TROUGH OR WEAK LOW NEAR ANDROS ISLAND IN THE
NORTHWESTERN BAHAMAS.
MODELS HAVE VARIOUS DEPICTIONS OF THE STRENGTH OF ANY LOW LEVEL
CIRCULATION ASSOCIATED WITH THIS FEATURE...BUT ALL KEEP THE STRONGER
WINDS/HEAVIEST RAIN ON ITS EASTERN FLANK. RIGHT NOW NHC HAS A 40
PERCENT CHANCE OF THIS AREA RE-DEVELOPING INTO A TROPICAL CYCLONE IN
THE NEXT 48 HOURS...WITH ITS PROXIMITY TO LAND...THE UPPER LEVEL
TROUGH JUST TO OUR NORTH AND...LACK OF ORGANIZATION WORKING AGAINST
IT. REGARDLESS OF DEVELOPMENT...THE STRONG TROUGH/WEAK LOW WILL MOVE
NORTHWEST TOWARDS THE SE FLORIDA COAST TODAY BEFORE SWINGING
NORTHWARDS TO PARALLEL THE EAST CENTRAL FLORIDA COAST TODAY AND
TONIGHT.
THE EXPECTED LOCATION OF THE LOW WILL PUT MOST OF EAST CENTRAL
FLORIDA WILL BE UNDER WHAT GENERALLY IS UNFAVORABLE NORTH-NORTHEAST
FLOW. HOWEVER...THE FLOW WILL REMAIN LIGHT ENOUGH FOR THE WEST COAST
SEA BREEZE TO DEVELOP AND MOVE INLAND LATE IN THE AFTERNOON. WATER
VAPOR SATELLITE SHOWS COMPARATIVELY DRIER AIR WRAPPING AROUND THE
NORTH AND WESTERN PERIPHERY OF THE CIRCULATION THIS MORNING...WHICH
WILL PIVOT INTO THE REGION THIS AFTERNOON...SHUNTING THE MOISTURE
ASSOCIATED WITH THE NORTHERN TROUGH FURTHER WEST. MODELS ARE ALL
UNANIMOUS IN KEEPING THE BEST MOISTURE/STRONGER WINDS ASSOCIATED
WITH THE REMNANTS ON THE EASTERN SIDE OF THE LOW AS IT LIFTS
NORTHWARDS. STILL...WITH WEAK TO NON EXISTENT STEERING FLOW HEAVY
RAIN WILL BE A CONCERN ESPECIALLY WITH THE LATE DAY COLLISION OF THE
SEA BREEZES. THE TREASURE COAST MAY ALSO BECOME A CONCERN FOR HEAVY
RAIN DEPENDING ON HOW FAR NORTHWEST THE MOISTURE PLUME ASSOCIATED
WITH THE LOW TRACKS BEFORE IT TURNS NORTHERLY.
THE EAST COAST SEA BREEZE WILL BE ENHANCED BY THE ONSHORE FLOW AND
QUICKLY MOVE INLAND...LIMITING RAIN CHANCES FOR MOST OF THE COAST.
THE EXCEPTION WILL BE ACROSS THE TREASURE COAST WHERE PROXIMITY TO
THE WEAK LOW WILL KEEP THE POSSIBILITY FOR ONSHORE MOVING SHOWERS
AND STORMS THROUGH THE DAY. THE BEST RAIN CHANCES WILL BE OVER THE
INTERIOR WEST OF THE ORLANDO METRO LATE THIS AFTERNOON AND EVENING.
MAV GUIDANCE SEEMS A LITTLE HIGH WITH AFTERNOON TEMPS GIVEN THE
EXPECTED ONSHORE FLOW SO HAVE KEPT THEM IN THE UPPER 80S ALONG THE
COAST AND LOW 90S INLAND.
TONIGHT...WEAK LOW LIFT FURTHER UP THE COAST AND OFF TO THE
NORTHEAST BRINGING FLOW AROUND TO THE WEST-SOUTHWEST BY THE EVENING
HOURS. THIS MAY KEEP A FEW SHOWERS AND STORMS ACROSS LAKE
COUNTY...THE KISSIMMEE RIVER...AND ALONG THE LAKE OKEECHOBEE COAST
THROUGH THE LATE EVENING HOURS.
SATURDAY...THE REMNANTS OF DORIAN SHOULD ROUND THE PERIPHERY OF THE
MID LVL RIDGE OVER THE ATLC AND BE ACROSS THE OFFSHORE WATERS EARLY
SATURDAY AND PULL FURTHER NE AWAY FROM THE AREA IN THE AFTERNOON.
LIGHT LOW LVL W/SW FLOW AND LIGHT WEST TO NW MID LYR FLOW SHOULD
ALLOW SCATTERED CONVECTION TO DEVELOP SATURDAY AFTERNOON WITH THE
DEVELOPING EAST COAST SEA BREEZE ACROSS THE COASTAL COUNTIES. FOR
NOW WILL DISCOUNT THE STRONGER NAM WIND FIELDS AND DEEPER MOISTURE
ON THE WEST SIDE OF DORIAN BUT STILL KEEP SHOWER/T-STORM CHANCES
AROUND 40 PCT.
SUNDAY...MID LVL RIDGE WILL EXTEND FROM THE NRN GULF COAST TO THE
WRN FLORIDA PENINSULA WITH SOME MID LVL DRYING LOWERING PWATS TO
AROUND 1.7 INCHES ACROSS CENTRAL SECTIONS OF THE FORECAST AREA. GFS
MOS POPS HAVE DROPPED BELOW 20 PCT BUT NAM MOS IS AROUND 40 PCT.
SOME MID TO LATE AFTERNOON SHOULD DEVELOP ON THE EASTERN SIDE OF THE
PENINSULA BUT COVERAGE SHOULD BE LOWER THAN SATURDAY. WILL LOWER
POPS TO 30 PCT FOR NOW AND KEEP AN EYE ON MOISTURE TRENDS WITH
UPCOMING MODELS. THE MAIN STORY FOR THE WEEKEND WILL BE THE HEAT IN
AREAS THAT DO NOT SEE ANY RELIEF FROM AFTERNOON STORMS. HIGHS SHOULD
HIT THE MID 90S ACROSS THE INTERIOR AND LOWER 90S ACROSS THE COASTAL
COUNTIES.
&&
.AVIATION...TEMPO MVFR CONDITIONS ALONG THE COAST AS SHOWERS AND LOW
STRATOCU MOVE NORTH TO SOUTH ALONG THE COAST THIS AFTERNOON.
TEMPO MVFR CONDITIONS INTERIOR SITES STARTING AROUND THE INTERSTATE
95 CORRIDOR EARLY AFTERNOON...16Z-18Z...THEN WORKING THEIR WAY WEST
ACROSS THE ORLANDO AREA...18Z-21Z...AND LAKE COUNTY MID TO LATE
AFTERNOON...21Z-01Z...BEFORE WINDING DOWN FOR THE NIGHT
PREVIOUS
ONSHORE FLOW AROUND THE PERIPHERY OF THE REMNANTS OF
DORIAN MOVING THROUGH THE BAHAMAS AND SE FLORIDA COAST TODAY WILL
QUICKLY PUSH THE EAST COAST SEA BREEZE INLAND WITH SCT SHRA/TSRA
POSSIBLE AT ALL TERMINALS 16Z-19Z...BEFORE SEA BREEZE SHIFTS WELL
INLAND. BEST COVERAGE WILL BE WEST OF KMCO...VCNTY KVVG-KLEE-KISM
AFTER 21Z.
&&
.MARINE...
CURRENT-THIS AFTERNOON...BUOY 009 WAS RECORDING NORTHEAST WINDS
AROUND 5 KNOTS WHILE THE REST OF THE BUOYS THAT HAD WIND RECORDING
INSTRUMENTS ON THEM WERE RECORDING WEST TO NORTHWEST WINDS AROUND 5
KNOTS. ALL THE WAVE HEIGHT RECORDING BUOYS WERE INDICATING 2 FOOT
SEAS WITH A WAVE PERIOD BETWEEN 8 AND 9 SECONDS.
EXPECT THAT THE NEARSHORE WINDS WILL SHIFT ONSHORE AND REMAIN AROUND
10 KNOTS THIS AFTERNOON AS THE EAST COAST SEA BREEZES FORMS AND
START WORKING THEIR WAY WEST.
PREVIOUS MARINE DISCUSSION
TODAY-TONIGHT...THE EXACT WIND FORECAST FOR TODAY WILL
DEPEND ON WHAT FORM THE REMNANTS OF DORIAN TAKE AS THEY MOVE THROUGH
THE BAHAMAS AND SE FLORIDA COAST TODAY AND TONIGHT. OVERALL THE
STRONGEST WINDS ARE EXPECTED TO REMAIN WELL OFFSHORE...WITH LIGHT
SOUTH-SOUTHEAST FLOW THIS MORNING BECOMING EAST-NORTHEAST AROUND
10KTS THIS AFTERNOON. WATERS SOUTH OF SEBASTIAN INLET WILL BECOME
MORE SOUTHERLY AS THE FEATURE LIFTS NORTH THIS EVENING...WITH
EVENTUALLY ALL THE WATERS BECOMING WEST-SOUTHWEST LATE TONIGHT. SEAS
2-3 FEET. COVERAGE OF SHOWERS AND STORMS WILL BE HIGHEST OVER THE
OFFSHORE WATERS AND NEARSHORE WATERS SOUTH OF SEBASTIAN INLET.
SATURDAY...DISTURBED WEATHER IS FORECAST ACROSS THE OFFSHORE WATERS
TO START THE DAY AS THE REMNANTS OF DORIAN MOVE NWD AROUND THE
RIDGE. HAVE TRENDED TOWARD WEAKER GFS WINDS WITH SEAS 2-3 FT NEAR
SHORE AND 3 FT OFFSHORE. SUNDAY...EXPECT WEST TO SOUTHWEST WINDS TO
10 KNOTS AND SEAS 2 FT NEAR THE COAST AND 3 FT OFFSHORE. SW WINDS
EARLY IN THE WEEK WILL BECOME SE BY WED/THU WITH MOST OF THE
CONVECTIVE ACTIVITY OVER THE MAINLAND IN THE AFTERNOON BY MID WEEK.
SEAS MAINLY 2-3 FT.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...WIMMER
IMPACT WX...BRAGAW
AREA FORECAST DISCUSSION
NWS JACKSON MS
1007 AM CDT FRI AUG 2 2013
.UPDATE...
SURFACE HIGH PRESSURE IS SITUATED OFF TO OUR NORTH IN THE MID
MISSISSIPPI VALLEY. ALTOGETHER...STILL EXPECTING A QUIET DAY. AN
ISOLATED STORM IN THE SOUTH TODAY CANNOT BE RULED OUT THOUGH. THERE
IS EVEN A CHANCE OF A MICROBURST IF ONE DOES FORM. SOME HIGH CIRRUS
COVERS MUCH OF THE CWA NOW. NO ADJUSTMENTS TO THE FORECAST WERE
NEEDED THIS MORNING. /10/
&&
.AVIATION...
EXPECT VFR CONDITIONS FOR THE REST OF THE DAY AND THROUGH THE
EVENING. AN ISOLATED SHOWER OR STORM IS POSSIBLE ALONG AND SOUTH OF
THE I-20 CORRIDOR TODAY...BUT CHANCES OF HITTING A TAF SITE ARE QUITE
LOW. LATE TONIGHT AND EARLY SATURDAY MORNING... POTENTIAL FOR AT
LEAST MVFR STRATUS OR MIST WILL EXIST PRIMARILY AT
JAN/HKS/MEI/NMM/PIB/HBG. EXPECT ANY FOG/STRATUS TO BURN OFF BY MID
MORNING SATURDAY WITH VFR CONDITIONS THEN ANTICIPATED FOR THE
AFTERNOON AND EVENING. /BB/EC/
&&
.PREV DISCUSSION... /ISSUED 415 AM CDT FRI AUG 2 2013/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...ANOTHER HOT DAY ON TAP
TODAY...ESPECIALLY IN THE SOUTHWEST HALF OF THE REGION WHERE THE
AIRMASS WILL BE MORE HUMID. BOUNDARY THAT PUSHED THROUGH YESTERDAY
TRIGGERING AFTERNOON SHOWERS AND STORMS IN SOUTH MS IS NOW RATHER
WASHED OUT NEAR THE COAST WITH CURRENT SURFACE REFLECTION OF LOWER
HUMIDITY AND TEMPS REALLY ONLY VERY EVIDENT FROM GREENVILLE SOUTH TO
MERIDIAN AND POINTS NORTHEAST. MOISTURE POOLED AT 5000 FEET ABOVE
GROUND DUE TO THE BOUNDARY IS NOW EVIDENT ALONG AND SOUTH OF I-20 AS
SCATTERED CLOUDS. PREVIOUS EXPECTATIONS WERE FOR VERY MINIMAL RAIN
CHANCES TODAY BUT NOW IT SEEMS AT LEAST VERY ISOLATED SHOWERS AND
STORMS WILL LIKELY TRIGGER IN MANY CENTRAL AND SOUTHERN ZONES THANKS
TO THE RESERVOIR OF POOLED MOISTURE. LATEST HRRR EXPLICIT OUTPUT
SUGGESTS AS MUCH. DO NOT THINK THIS ACTIVITY WILL ULTIMATELY WET
MANY PEOPLE OR CUT HEAT...BUT IT WAS WORTH MENTIONING IN FORECAST.
HIGHS WILL RANGE FROM 94 TO 97 WITH HOTTEST TEMPS IN CENTRAL AND
SOUTHERN ZONES WHERE PEAK HEAT INDICES MAY MEET OR EXCEED 105 FOR AN
HOUR OR TWO IN SOME SPOTS...ESPECIALLY WEST OF THE MS RIVER.
CONSIDERED A HEAT ADVISORY FOR THESE AREAS BUT EXPLICIT CRITERIA NOT
QUITE BEING MET.
TONIGHT...LARGE CURRENT SOUTHEAST PROPAGATING MCS IN EASTERN KANSAS
COULD HAVE A COUSIN CLOSER TO THE VICINITY OF MY NORTHWEST ZONES BY
THE WEE HOURS. CHANCES FOR ANY PRECIPITATION IN SUCH A SCENARIO
GETTING INTO THE REGION BEFORE DAWN ARE VERY LOW...BUT DEBRIS CLOUDS
BLOWING DOWNSTREAM COULD HOLD UP TEMPS SOMEWHAT. OTHERWISE...EXPECT
QUIET CONDITIONS WITH POTENTIAL FOR BUILDING SOUTHERLY FLOW TO
PRODUCE SOME LOW STRATUS IN SOUTHERN HALF OF ZONES BY DAWN SATURDAY.
SATURDAY AND SATURDAY NIGHT...ANY EARLY MORNING MCS ACTIVITY
REFERRED TO ABOVE SHOULD BE DECAYING AS IT TRIES TO ENTER INTO THE
REGION FROM THE NORTHWEST THROUGH THE FIRST HALF OF THE DAY.
WILDCARD OF A POTENTIAL MCV SPURRING SOME CONVECTION IN THE
NORTHEAST HALF OF ZONES WARRANTS SLIGHT CHANCE OF SHOWERS AND STORMS
MENTION...BUT ONLY THAT MUCH SINCE MANY OTHER FACTORS REMAIN RATHER
HOSTILE TO ANY MORE THAN ISOLATED COVERAGE. REGARDLESS OF WHETHER
THERE IS ACTUAL PRECIP HITTING THE GROUND ANYWHERE...CHANCES ARE
GOOD THERE WILL BE A FAIR AMOUNT OF HIGH TO MID LEVEL CLOUDS AROUND
TO REDUCE INSOLATION A BIT. THIS EXPLAINS MEX TEMPS A LITTLE COOLER
THAN TODAY IN MANY AREAS. HUMIDITY WILL BE INCREASING ACROSS THE
BOARD THOUGH AND PEAK HEAT INDEX WILL COME CLOSE OR EXCEED 100
DEGREES IN MOST LOCATIONS. BY SATURDAY NIGHT THE POTENTIAL FOR
JUXTAPOSITION OF CONVECTIVE BOUNDARIES...NON-TRIVIAL MOISTURE
CONVERGENCE...AND PASSING WEAK DISTURBANCES IN NORTHWEST FLOW
SUGGEST SOME CHANCE OF SOUTHERN FRINGE OF TN VALLEY AND MIDSOUTH
THUNDERSTORM ACTIVITY BRUSHING NORTHERN HALF OF ZONES. ONLY SLIGHT
CHANCE POPS FOR NOW. /BB/
LONG TERM...SUNDAY THROUGH NEXT FRIDAY...MODELS CONTINUE TO AGREE
WITH KEEPING THE MID/UPPER RIDGE WEDGED INTO THE FORECAST AREA FROM
THE WEST THROUGH AT LEAST THE MID-RANGE PORTION OF THE FORECAST...
BEFORE SHIFTING IT EAST AND NEARLY DIRECTLY OVER THE ARKLAMISS
DURING THE EXTENDED. THE BEST RAIN CHANCES CONTINUE TO LOOK TO BE
FAIRLY EARLY IN THE PERIOD...SPECIFICALLY SUNDAY...MONDAY...AND
TUESDAY AFTERNOONS...AND ON THE EASTERN PERIPHERY OF THIS RIDGE AS
NORTHERLY FLOW TRIES TO SETUP OVER REGION. THIS IN ADDITION TO
INCREASED LOW LEVEL MOISTURE AND A WEAK SURFACE BOUNDARY THAT`S
PROGGED TO DROP SOUTH INTO THE CWA SUNDAY...AND EVENTUALLY WASHOUT
ON TUESDAY. CHANCES FOR SHOWERS AND STORMS WILL LINGER THROUGH THE
REMAINDER OF THE FORECAST PERIOD...WEDNESDAY THROUGH FRIDAY...BUT
CHANCES WILL BE LOWER AND THE CENTER OF THE RIDGE IS AGAIN EXPECTED
TO SHIFT ALMOST DIRECTLY OVER THE FORECAST AREA.
I DIDN`T STRAY FAR FROM GFS GUIDANCE IN TERMS OF TEMPERATURES.
OVERALL...HIGHS EACH AFTERNOON WILL CLIMB INTO THE MIDDLE 90S WITH
PLENTY OF HUMIDITY PRESENT AS DEW POINTS GENERALLY SIT AROUND 70F.
THIS LOOKS TO YIELD A FEW PERIODS THROUGHOUT EACH DAY WHERE HEAT
INDICES COULD CLIMB BETWEEN 100-105F. THAT SAID...FORECAST HIGHS
COULD OBVIOUSLY BE LOWER IF CLOUD COVER AND/OR CONVECTION ARE MORE
PREVALENT...WHICH IN TURN WOULD HELP KEEP HEAT INDEX VALUES IN
CHECK. LOWS EACH NIGHT WILL REMAIN MILD AND ONLY FALL INTO THE
MIDDLE 70S. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 97 73 95 76 / 11 9 16 16
MERIDIAN 95 71 95 74 / 3 9 17 16
VICKSBURG 96 73 95 73 / 11 8 13 13
HATTIESBURG 97 74 96 75 / 11 10 10 10
NATCHEZ 95 74 95 74 / 11 9 10 8
GREENVILLE 95 74 95 76 / 3 11 20 20
GREENWOOD 95 71 95 75 / 3 8 21 20
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
657 AM CDT FRI AUG 2 2013
.AVIATION...
12Z TAFS FOR KOFK...KOMA AND KLNK.
ANOTHER ROUND OF SHOWERS AND ISOLATED THUNDERSTORMS SPROUTED
OVERNIGHT IN SOUTH DAKOTA. THESE SHOWERS ARE SPREADING SOUTHEAST
WITH TIME. FOR NOW DID MENTION SHOWERS AT KOFK AND KOMA. COVERAGE
UNCERTAIN SO LEFT OUT THUNDER. ADDITIONAL SHOWERS AND
THUNDERSTORMS MAY DEVELOP AND AFFECT LINCOLN. CONDITIONS SHOULD
GENERALLY BE VFR...HOWEVER SOME PATCHY MVFR CIGS COULD DEVELOP AT
KOFK OR KOMA. AS TEMPERATURES WARM INTO THE 80S THIS AFTERNOON
SHOWERS AND THUNDERSTORMS SHOULD RE-DEVELOP ALTHOUGH DUE TO
COVERAGE AND TIMING UNCERTAINTIES HAVE NOT INCLUDED IN THE TAFS AT
THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 310 AM CDT FRI AUG 2 2013/
DISCUSSION...
A RELATIVELY UNSETTLED WEATHER PATTERN WILL CONTINUE OVER OUR PART
OF THE COUNTRY INTO NEXT WEEK AS WE REMAIN UNDER FAST WEST TO
NORTHWEST FLOW ALOFT BETWEEN LARGE/DEEP UPPER LOW IN CANADA AND
BROAD HIGH IN THE SOUTHERN STATES. SEVERAL IMPULSES WILL WORK
THROUGH THIS FLOW THROUGH NEXT WEEK...BRINGING OCCASIONAL
THUNDERSTORM CHANCES AS SURFACE FRONT WOBBLES NORTH/SOUTH
AHEAD/BEHIND EACH WAVE.
FOR TODAY...MOST THUNDERSTORM ACTIVITY ASSOCIATED WITH THURSDAY
AFTERNOON/EVENING CONVECTION HAS SHIFTED SOUTH OF OUR AREA. HOWEVER
STRENGTHENING LOW LEVEL JET IN CENTRAL NEBRASKA HAS FIRED ADDITIONAL
STORMS IN SOUTH CENTRAL SOUTH DAKOTA. THIS ACTIVITY WILL LIKELY
DRIFT/DEVELOP EAST AND SOUTHEAST INTO NORTHEAST NEBRASKA AS LOW
LEVEL JET BECOMES SOUTHWESTERLY WITH TIME THIS MORNING. MODELS WERE
NOT HANDLING THIS PRECIPITATION PARTICULARLY WELL...BUT A BLEND OF
RAP AND HRRR SOLUTIONS OFFERS SOME RELIABILITY. EXPECT RAIN WITH
EMBEDDED STORMS CURRENTLY IN SOUTH CENTRAL NEBRASKA TO SPREAD ACROSS
THE SOUTHWEST THIRD OF THE CWA THROUGH MID MORNING WITH A DECREASING
TREND INTO EARLY AFTERNOON. SEVERE STORMS ARE NOT ANTICIPATED AS
ATMOSPHERE WAS WORKED OVER FAIRLY WELL OVERNIGHT. ANOTHER ROUND OF
STORMS COULD THEN DEVELOP IN THE MID TO LATE AFTERNOON AS A
SHORTWAVE EJECTS FROM THE HIGH PLAINS OF WYOMING/MONTANA AND SLIDES
SOUTHEAST. STORMS WOULD MOST LIKELY FORM IN SOUTH CENTRAL SOUTH
DAKOTA OR NORTH CENTRAL NEBRASKA THEN SPREAD SOUTHEAST ACROSS THE
WESTERN CWA DURING THE LATE AFTERNOON AND EVENING. SURFACE DEW
POINTS ARE FORECAST TO APPROACH 70...HELPING TO GENERATE 3000 J/KG
OR GREATER SURFACE-BASED CAPE OVER PARTS OF THE CWA. EXACT AXIS OF
HIGHEST INSTABILITY WILL BE AFFECTED BY ONGOING ACTIVITY THIS
MORNING...BUT LOOKS LIKE IT WILL SET UP OVER THE SOUTHERN HALF OF
OUR AREA. FARTHER NORTH...FASTER MID LEVEL FLOW WILL YIELD 50KT OF
BULK SHEAR...SO ANY STORMS THAT WORK INTO NORTHEAST NEBRASKA WILL BE
POTENTIALLY SEVERE AS WELL.
CONVECTION SHOULD BE SETTLING SOUTH OF NEBRASKA AFTER MIDNIGHT AS
SHORTWAVE MOVES OFF TO THE EAST. MOST OF SATURDAY THEN LOOKS DRY
WITH FOCUS FOR STORMS IN THE HIGH PLAINS. THEN THE NEXT SHORTWAVE
SHOULD BE ROLLING INTO THE AREA SATURDAY NIGHT SETTING UP ANOTHER
ROUND OF STORMS AS LOW LEVEL JET ONCE AGAIN DRIVES CONVECTION IN
WARM ADVECTION REGIME. THIS CONVECTION WILL LIKELY LINGER INTO AT
LEAST SUNDAY MORNING BEFORE MOVING OFF TO THE SOUTHEAST.
MUCH OF THE SAME IS FORECAST FOR NEXT WEEK. MONDAY OFFERS THE BEST
CHANCE FOR A DRY FORECAST BEFORE A STRONGER SHORTWAVE PUSHES A FRONT
THROUGH OUR AREA TUESDAY...WHICH THEN LIFTS BACK NORTH ON WEDNESDAY.
WILL NOT CHANGE FORECAST MUCH FROM GOING NUMBERS TUESDAY THROUGH
THURSDAY AS TIMING SHORTWAVES THIS FAR OUT IS DIFFICULT. HOWEVER
PATTERN CERTAINLY FAVORS AT LEAST A CHANCE FOR STORMS EACH DAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1030 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL CONTINUE TO DEVELOP ACROSS OUR
REGION TODAY. THIS COLD AIR ALOFT...COMBINED WITH SOME SURFACE
HEATING WILL HELP IN THE DEVELOPMENT OF ADDITIONAL SCATTERED SHOWERS
AND THUNDERSTORMS THIS AFTERNOON...WITH SOME STORMS CONTAINING SMALL
HAIL. THE CHANCES FOR SHOWERS WILL CONTINUE ON SATURDAY WITH
TEMPERATURES DROPPING TO BELOW NORMAL VALUES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM EDT FRIDAY...FORECAST IN GOOD SHAPE AS WE HEAD INTO
THE LATE MORNING HOURS. DID ADJUST SKY COVER DOWNWARD THROUGH
EARLY TO MID AFTERNOON BASED OFF CURRENT OBSERVATIONAL DATA. ALSO
TWEAKED HOURLY TEMP DATA...WHICH PER 925 MB THERMAL PROGS AND AT
LEAST A DECENT AMOUNT OF INSOLATION TODAY SUGGEST MAX TEMPS MAY BE
A BIT HIGHER THAN EARLIER INDICATIONS. PRIOR DISCUSSION FOLLOWS.
HAVE A GREAT DAY.
FCST CHALLENGE TODAY WL BE AREAL COVERAGE/INTENSITY OF
SHOWERS/ISOLATED STORMS...FOLLOWED BY TEMPS. CRNT WATER VAPOR
SHOWS DIGGING MID/UPPER LVL TROF ACRS THE EASTERN GREAT LAKES WITH
RIBBON OF ENHANCED JET STREAM WINDS FROM THE OHIO VALLEY INTO
WESTERN NY. SATL LOOP SHOWED PLENTY OF POPCORN TYPE SHOWERS WITH
EMBEDDED LIGHTNING ACTIVITY UPSTREAM YESTERDAY AFTN ASSOCIATED
WITH 5H VORT ACRS THE NORTHERN LAKES. LARGE SCALE MODELS SHOW THIS
ELONGATED VORT LOBE IMPACTING OUR CENTRAL/NORTHERN CWA THIS
AFTN...WHILE RIBBON OF ENHANCED DEEP LAYER SHEAR ASSOCIATED WITH
MID/UPPER LVL JET MAX IS LOCATED ACRS THE MID ATLANTIC STATES.
HOWEVER...FEEL ENOUGH CLRING WL DEVELOP TO WARM SFC TEMPS INTO THE
M/U 70S...AND CREATE SFC BASED CAPE VALUES BTWN 1200 AND 1800
J/KG...ESPECIALLY AS COOLING ALOFT OCCURS. THIS INSTABILITY WL
PROMOTE STRONG ENOUGH UPDRAFTS TO SUPPORT MENTION OF THUNDER WITH
SOME SMALL HAIL POSSIBLE...GIVEN WBZ HGHTS BTWN 8000 AND 9000 FT
AND 500MB TEMPS BTWN -16C AND -18C. WL MENTION SMALL HAIL
POTENTIAL IN HWO. RAP 13 CONTS TO SHOW BEST PVA WITH S/W ENERGY
ARRIVING DURING MAX DAYTIME HEATING...WITH BEST 850 TO 500MB RH
ALONG THE INTERNATIONAL BORDER. FEEL THE LIMITED DEEP LAYER RH AND
PWS FALLING TO AROUND 1"...WL LIMIT AREAL COVERAGE OF
SHOWERS/STORMS THIS AFTN...WL MENTION CHC POPS WITH HIGHEST POPS
ACRS THE NORTHERN MTNS OF NY/VT. PROGGED 85H TEMPS BTWN
10-12C...WITH SOME MIXING/SUN WL SUPPORT HIGHS MID/UPPER 70S
CPV/SLV AND CT RIVER VALLEY WITH U60S TO L70S MTN/NEK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 410 AM EDT FRIDAY...LITTLE CHANGE IN OVERALL FCSTER THINKING
WITH VERY GOOD AGREEMENT AMONG THE LARGE SCALE MODELS...WHICH
CONTS TO SUPPORT A DEEP MID/UPPER LVL TROF ACRS OUR CWA THRU THE
WEEKEND. THIS SYNOPTIC SCALE FEATURE WL RESULT IN BLW NORMAL TEMPS
AND CHCS FOR SHOWERS THRU SAT AFTN. FCST FOCUS WL BE TIMING
INDIVIDUAL S/W`S IN THE WEST TO NORTHWEST FLW ALOFT. POTENT 5H
VORT IS EXPECTED TO IMPACT OUR CWA BTWN 06Z AND 15Z FRIDAY
NIGHT/SATURDAY MORNING...WITH STRONG DYNAMICS AND SOME 850 TO
500MB RH PRESENT. GIVEN THE PROGGED LARGE SCALE ASCENT ASSOCIATED
WITH THIS FEATURE...WOULD NOT BE SURPRISED FOR A FEW ISOLATED
STORMS...ON FRIDAY NIGHT/SATURDAY MORNING. THIS ENERGY WL LIFT NE
OF OUR CWA BY 15Z SATURDAY...WITH MUCH DRIER AIR AND LARGE SCALE
SUBSIDENCE DEVELOPING. THINKING AREAL COVERAGE/INTENSITY OF
SHOWERS WL BE LIMITED ON SAT AFTN...DUE TO DRYING ALOFT AND PWS
FALLING BTWN 0.50 AND 0.75". WL MENTION SCHC VALLEYS TO CHC POPS
MTNS. SOUNDING PROFILES SHOW VERY MODEST CAPE/INSTABILITY WITH
VALUES BTWN 200-400 J/KG. FOR FRIDAY NIGHT TIME PERIOD...WL
MENTION HIGH CHC POPS WITH SOME LOW LIKELY POPS NORTHERN DACKS.
QPF WL RANGE BTWN 0.10 AND 0.25". PROGGED 85H TEMPS REMAIN BTWN
10-12C ON SAT...SUPPORTING SLIGHTLY BLW NORMAL TEMPS MAINLY 60S
MTNS TO 70S VALLEYS. ON SUNDAY...MID/UPPER LVL TROF SHARPENS ACRS
OUR FA...AS ANOTHER POTENT VORT AND SFC COLD FRNT IMPACT THE
REGION. GFS/NAM AND ECMWF SHOW BETTER MOISTURE PROFILES ACRS OUR
FA...ALONG WITH GREATER COVERAGE IN QPF. WL MENTION HIGH CHC POPS
ATTM...BUT AN INCREASE TO LIKELY POPS MAYBE NEEDED IF CRNT TRENDS
CONT. HIGHEST POPS AND QPF WL BE ACRS THE MTN AREAS...WITH
RAINFALL AMOUNTS BTWN 0.10 AND 0.25". SOUNDINGS SHOW LIMITED
INSTABILITY WITH CAPE VALUES ONLY BTWN 100 AND 300 J/KG...WL NOT
MENTION THUNDER ATTM. 85H TEMPS DROP SEVERAL DEGREES FROM SATURDAY
AND SUPPORT HIGHS U50S/L60S MTNS/NEK TO M60S TO L70S VALLEYS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 410 AM EDT FRIDAY...PRONOUNCED NORTHWEST FLOW ALOFT ON THE
BACKSIDE OF DEPARTING UPPER TROUGH WILL BRING COOLER AND DRIER
WEATHER TO THE AREA SUNDAY NIGHT INTO MONDAY. COLD AIR ADVECTION
ON MONDAY SUGGESTS HIGHS ONLY IN THE UPPER 60S TO THE MID
70S...WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR. DRY WEATHER CONTINUES MONDAY NIGHT INTO TUESDAY AS
FLOW ALOFT REMAINS FROM THE NORTHWEST. TEMPERATURES BEGIN TO
SLOWLY MODERATE WITH HIGH TEMPERATURES 2 TO 4 DEGREES WARMER THAN
MONDAY. THE TREND TOWARD MORE NORMAL TEMPERATURES BEGINS ON
WEDNESDAY AS FLOW ALOFT BACKS TO THE WEST AND ALLOWS FOR WARM AIR
ADVECTION TO TAKE PLACE. HIGHS WILL BE IN THE 70S TO AROUND 80
BOTH WEDNESDAY AND THURSDAY. THE WESTERLY FLOW ALOFT WILL ALLOW
FOR A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY. AS A RESULT...THE THREAT FOR SHOWERS WILL
RETURN AND WILL MENTION A CHANCE OF SHOWERS ON BOTH DAYS.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
THROUGH 12Z SATURDAY...STILL DEALING WITH SOME LOWER CEILINGS AND
VISIBILITIES ACROSS THE AREA. LOOK FOR MVFR TO IFR CEILINGS AND
VISIBILITIES THROUGH 14Z BEFORE VFR CONDITIONS DEVELOP ALL AREAS.
EXPECTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON AND EVENING WITH MVFR CONDITIONS POSSIBLE WITH THE
PRECIPITATION...ESPECIALLY BETWEEN 18Z AND 02Z. AFTER 02Z THERE
WILL STILL BE MVFR CEILINGS LINGERING OVER THE AREA AND SCATTERED
SHOWERS WILL ALSO EXIST...HOWEVER VISIBILITIES SHOULD REMAIN IN
THE VFR CATEGORY. WINDS WILL GENERALLY BE FROM THE SOUTH AND
SOUTHWEST FROM MID-MORNING ON...BUT SPEEDS WILL GENERALLY BE UNDER
15 KNOTS.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY...
12Z SATURDAY THROUGH 06Z MONDAY...SERIES OF UPPER LEVEL
DISTURBANCES WILL BRING SHOWERS TO THE REGION AT TIMES ALONG WITH
WIDELY SCATTERED STORMS. CONDITIONS LOWERING AT TIMES TO MVFR.
06Z MONDAY THROUGH 00Z WEDNESDAY...VFR CONDITIONS WITHIN A RIDGE
OF SFC HIGH PRESSURE.
&&
.EQUIPMENT...
AS OF 1030 AM EDT FRIDAY...NOAA WEATHER RADIO WXM
44...BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...WILL BE
OFF THE AIR UNTIL FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
KTYX RADAR WILL BE DOWN FOR A FEW HOURS THIS MORNING FOR TESTING.
THE RADAR SHOULD RETURN TO SERVICE BY THIS AFTERNOON.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...JMG/TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/RJS
EQUIPMENT...BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
727 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL CONTINUE TO DEVELOP ACROSS OUR
REGION TODAY. THIS COLD AIR ALOFT...COMBINED WITH SOME SURFACE
HEATING WILL HELP IN THE DEVELOPMENT OF ADDITIONAL SCATTERED SHOWERS
AND THUNDERSTORMS THIS AFTERNOON...WITH SOME STORMS CONTAINING SMALL
HAIL. THE CHANCES FOR SHOWERS WILL CONTINUE ON SATURDAY WITH
TEMPERATURES DROPPING TO BELOW NORMAL VALUES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 705 AM EDT FRIDAY...UPDATED FCST TO DECREASE POPS ACRS OUR
CWA THIS MORNING...AS CRNT RADAR SHOWS VERY LIMITED ACTIVITY.
WATER VAPOR SHOWS BEST DEEP LAYER RH HAS SHIFTED TO OUR
EAST...WHILE BEST PVS IS JUST NORTH OF OUR FA. BETTER DYNAMICS
LOCATED OVER THE NORTHERN GREAT LAKES WL IMPACT OUR REGION BY 18Z
THIS AFTN...WITH ADDITIONAL SHOWERS. HAVE CONTINUED TO MENTION CHC
POPS THIS AFTN WITH TEMPS WARMING INTO THE U60S MTNS TO NEAR 80F
WARMER VALLEY LOCATIONS.
FCST CHALLENGE TODAY WL BE AREAL COVERAGE/INTENSITY OF
SHOWERS/ISOLATED STORMS...FOLLOWED BY TEMPS. CRNT WATER VAPOR
SHOWS DIGGING MID/UPPER LVL TROF ACRS THE EASTERN GREAT LAKES WITH
RIBBON OF ENHANCED JET STREAM WINDS FROM THE OHIO VALLEY INTO
WESTERN NY. SATL LOOP SHOWED PLENTY OF POPCORN TYPE SHOWERS WITH
EMBEDDED LIGHTNING ACTIVITY UPSTREAM YESTERDAY AFTN ASSOCIATED
WITH 5H VORT ACRS THE NORTHERN LAKES. LARGE SCALE MODELS SHOW THIS
ELONGATED VORT LOBE IMPACTING OUR CENTRAL/NORTHERN CWA THIS
AFTN...WHILE RIBBON OF ENHANCED DEEP LAYER SHEAR ASSOCIATED WITH
MID/UPPER LVL JET MAX IS LOCATED ACRS THE MID ATLANTIC STATES.
HOWEVER...FEEL ENOUGH CLRING WL DEVELOP TO WARM SFC TEMPS INTO THE
M/U 70S...AND CREATE SFC BASED CAPE VALUES BTWN 1200 AND 1800
J/KG...ESPECIALLY AS COOLING ALOFT OCCURS. THIS INSTABILITY WL
PROMOTE STRONG ENOUGH UPDRAFTS TO SUPPORT MENTION OF THUNDER WITH
SOME SMALL HAIL POSSIBLE...GIVEN WBZ HGHTS BTWN 8000 AND 9000 FT
AND 500MB TEMPS BTWN -16C AND -18C. WL MENTION SMALL HAIL
POTENTIAL IN HWO. RAP 13 CONTS TO SHOW BEST PVA WITH S/W ENERGY
ARRIVING DURING MAX DAYTIME HEATING...WITH BEST 850 TO 500MB RH
ALONG THE INTERNATIONAL BORDER. FEEL THE LIMITED DEEP LAYER RH AND
PWS FALLING TO AROUND 1"...WL LIMIT AREAL COVERAGE OF
SHOWERS/STORMS THIS AFTN...WL MENTION CHC POPS WITH HIGHEST POPS
ACRS THE NORTHERN MTNS OF NY/VT. PROGGED 85H TEMPS BTWN
10-12C...WITH SOME MIXING/SUN WL SUPPORT HIGHS MID/UPPER 70S
CPV/SLV AND CT RIVER VALLEY WITH U60S TO L70S MTN/NEK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 410 AM EDT FRIDAY...LITTLE CHANGE IN OVERALL FCSTER THINKING
WITH VERY GOOD AGREEMENT AMONG THE LARGE SCALE MODELS...WHICH
CONTS TO SUPPORT A DEEP MID/UPPER LVL TROF ACRS OUR CWA THRU THE
WEEKEND. THIS SYNOPTIC SCALE FEATURE WL RESULT IN BLW NORMAL TEMPS
AND CHCS FOR SHOWERS THRU SAT AFTN. FCST FOCUS WL BE TIMING
INDIVIDUAL S/W`S IN THE WEST TO NORTHWEST FLW ALOFT. POTENT 5H
VORT IS EXPECTED TO IMPACT OUR CWA BTWN 06Z AND 15Z FRIDAY
NIGHT/SATURDAY MORNING...WITH STRONG DYNAMICS AND SOME 850 TO
500MB RH PRESENT. GIVEN THE PROGGED LARGE SCALE ASCENT ASSOCIATED
WITH THIS FEATURE...WOULD NOT BE SURPRISED FOR A FEW ISOLATED
STORMS...ON FRIDAY NIGHT/SATURDAY MORNING. THIS ENERGY WL LIFT NE
OF OUR CWA BY 15Z SATURDAY...WITH MUCH DRIER AIR AND LARGE SCALE
SUBSIDENCE DEVELOPING. THINKING AREAL COVERAGE/INTENSITY OF
SHOWERS WL BE LIMITED ON SAT AFTN...DUE TO DRYING ALOFT AND PWS
FALLING BTWN 0.50 AND 0.75". WL MENTION SCHC VALLEYS TO CHC POPS
MTNS. SOUNDING PROFILES SHOW VERY MODEST CAPE/INSTABILITY WITH
VALUES BTWN 200-400 J/KG. FOR FRIDAY NIGHT TIME PERIOD...WL
MENTION HIGH CHC POPS WITH SOME LOW LIKELY POPS NORTHERN DACKS.
QPF WL RANGE BTWN 0.10 AND 0.25". PROGGED 85H TEMPS REMAIN BTWN
10-12C ON SAT...SUPPORTING SLIGHTLY BLW NORMAL TEMPS MAINLY 60S
MTNS TO 70S VALLEYS. ON SUNDAY...MID/UPPER LVL TROF SHARPENS ACRS
OUR FA...AS ANOTHER POTENT VORT AND SFC COLD FRNT IMPACT THE
REGION. GFS/NAM AND ECMWF SHOW BETTER MOISTURE PROFILES ACRS OUR
FA...ALONG WITH GREATER COVERAGE IN QPF. WL MENTION HIGH CHC POPS
ATTM...BUT AN INCREASE TO LIKELY POPS MAYBE NEEDED IF CRNT TRENDS
CONT. HIGHEST POPS AND QPF WL BE ACRS THE MTN AREAS...WITH
RAINFALL AMOUNTS BTWN 0.10 AND 0.25". SOUNDINGS SHOW LIMITED
INSTABILITY WITH CAPE VALUES ONLY BTWN 100 AND 300 J/KG...WL NOT
MENTION THUNDER ATTM. 85H TEMPS DROP SEVERAL DEGREES FROM SATURDAY
AND SUPPORT HIGHS U50S/L60S MTNS/NEK TO M60S TO L70S VALLEYS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 410 AM EDT FRIDAY...PRONOUNCED NORTHWEST FLOW ALOFT ON THE
BACKSIDE OF DEPARTING UPPER TROUGH WILL BRING COOLER AND DRIER
WEATHER TO THE AREA SUNDAY NIGHT INTO MONDAY. COLD AIR ADVECTION
ON MONDAY SUGGESTS HIGHS ONLY IN THE UPPER 60S TO THE MID
70S...WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR. DRY WEATHER CONTINUES MONDAY NIGHT INTO TUESDAY AS
FLOW ALOFT REMAINS FROM THE NORTHWEST. TEMPERATURES BEGIN TO
SLOWLY MODERATE WITH HIGH TEMPERATURES 2 TO 4 DEGREES WARMER THAN
MONDAY. THE TREND TOWARD MORE NORMAL TEMPERATURES BEGINS ON
WEDNESDAY AS FLOW ALOFT BACKS TO THE WEST AND ALLOWS FOR WARM AIR
ADVECTION TO TAKE PLACE. HIGHS WILL BE IN THE 70S TO AROUND 80
BOTH WEDNESDAY AND THURSDAY. THE WESTERLY FLOW ALOFT WILL ALLOW
FOR A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY. AS A RESULT...THE THREAT FOR SHOWERS WILL
RETURN AND WILL MENTION A CHANCE OF SHOWERS ON BOTH DAYS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
THROUGH 12Z SATURDAY...STILL DEALING WITH SOME LOWER CEILINGS AND
VISIBILITIES ACROSS THE AREA. LOOK FOR MVFR TO IFR CEILINGS AND
VISIBILITIES THROUGH 14Z BEFORE VFR CONDITIONS DEVELOP ALL AREAS.
EXPECTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON AND EVENING WITH MVFR CONDITIONS POSSIBLE WITH THE
PRECIPITATION...ESPECIALLY BETWEEN 18Z AND 02Z. AFTER 02Z THERE
WILL STILL BE MVFR CEILINGS LINGERING OVER THE AREA AND SCATTERED
SHOWERS WILL ALSO EXIST...HOWEVER VISIBILITIES SHOULD REMAIN IN
THE VFR CATEGORY. WINDS WILL GENERALLY BE FROM THE SOUTH AND
SOUTHWEST FROM MID-MORNING ON...BUT SPEEDS WILL GENERALLY BE UNDER
15 KNOTS.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY...
12Z SATURDAY THROUGH 06Z MONDAY...SERIES OF UPPER LEVEL
DISTURBANCES WILL BRING SHOWERS TO THE REGION AT TIMES ALONG WITH
WIDELY SCATTERED STORMS. CONDITIONS LOWERING AT TIMES TO MVFR.
06Z MONDAY THROUGH 00Z WEDNESDAY...VFR CONDITIONS WITHIN A RIDGE
OF SFC HIGH PRESSURE.
&&
.EQUIPMENT...
AS OF 1100 PM EDT THURSDAY...NOAA WEATHER RADIO WXM 44...BROADCASTING
FROM THE TOP OF MOUNT ASCUTNEY VERMONT...WILL BE OFF THE AIR UNTIL
FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/RJS
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
704 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL CONTINUE TO DEVELOP ACROSS OUR
REGION TODAY. THIS COLD AIR ALOFT...COMBINED WITH SOME SURFACE
HEATING WILL HELP IN THE DEVELOPMENT OF ADDITIONAL SCATTERED SHOWERS
AND THUNDERSTORMS THIS AFTERNOON...WITH SOME STORMS CONTAINING SMALL
HAIL. THE CHANCES FOR SHOWERS WILL CONTINUE ON SATURDAY WITH
TEMPERATURES DROPPING TO BELOW NORMAL VALUES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 705 AM EDT FRIDAY...UPDATED FCST TO DECREASE POPS ACRS OUR
CWA THIS MORNING...AS CRNT RADAR SHOWS VERY LIMITED ACTIVITY.
WATER VAPOR SHOWS BEST DEEP LAYER RH HAS SHIFTED TO OUR
EAST...WHILE BEST PVS IS JUST NORTH OF OUR FA. BETTER DYNAMICS
LOCATED OVER THE NORTHERN GREAT LAKES WL IMPACT OUR REGION BY 18Z
THIS AFTN...WITH ADDITIONAL SHOWERS. HAVE CONTINUED TO MENTION CHC
POPS THIS AFTN WITH TEMPS WARMING INTO THE U60S MTNS TO NEAR 80F
WARMER VALLEY LOCATIONS.
FCST CHALLENGE TODAY WL BE AREAL COVERAGE/INTENSITY OF
SHOWERS/ISOLATED STORMS...FOLLOWED BY TEMPS. CRNT WATER VAPOR
SHOWS DIGGING MID/UPPER LVL TROF ACRS THE EASTERN GREAT LAKES WITH
RIBBON OF ENHANCED JET STREAM WINDS FROM THE OHIO VALLEY INTO
WESTERN NY. SATL LOOP SHOWED PLENTY OF POPCORN TYPE SHOWERS WITH
EMBEDDED LIGHTNING ACTIVITY UPSTREAM YESTERDAY AFTN ASSOCIATED
WITH 5H VORT ACRS THE NORTHERN LAKES. LARGE SCALE MODELS SHOW THIS
ELONGATED VORT LOBE IMPACTING OUR CENTRAL/NORTHERN CWA THIS
AFTN...WHILE RIBBON OF ENHANCED DEEP LAYER SHEAR ASSOCIATED WITH
MID/UPPER LVL JET MAX IS LOCATED ACRS THE MID ATLANTIC STATES.
HOWEVER...FEEL ENOUGH CLRING WL DEVELOP TO WARM SFC TEMPS INTO THE
M/U 70S...AND CREATE SFC BASED CAPE VALUES BTWN 1200 AND 1800
J/KG...ESPECIALLY AS COOLING ALOFT OCCURS. THIS INSTABILITY WL
PROMOTE STRONG ENOUGH UPDRAFTS TO SUPPORT MENTION OF THUNDER WITH
SOME SMALL HAIL POSSIBLE...GIVEN WBZ HGHTS BTWN 8000 AND 9000 FT
AND 500MB TEMPS BTWN -16C AND -18C. WL MENTION SMALL HAIL
POTENTIAL IN HWO. RAP 13 CONTS TO SHOW BEST PVA WITH S/W ENERGY
ARRIVING DURING MAX DAYTIME HEATING...WITH BEST 850 TO 500MB RH
ALONG THE INTERNATIONAL BORDER. FEEL THE LIMITED DEEP LAYER RH AND
PWS FALLING TO AROUND 1"...WL LIMIT AREAL COVERAGE OF
SHOWERS/STORMS THIS AFTN...WL MENTION CHC POPS WITH HIGHEST POPS
ACRS THE NORTHERN MTNS OF NY/VT. PROGGED 85H TEMPS BTWN
10-12C...WITH SOME MIXING/SUN WL SUPPORT HIGHS MID/UPPER 70S
CPV/SLV AND CT RIVER VALLEY WITH U60S TO L70S MTN/NEK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 410 AM EDT FRIDAY...LITTLE CHANGE IN OVERALL FCSTER THINKING
WITH VERY GOOD AGREEMENT AMONG THE LARGE SCALE MODELS...WHICH
CONTS TO SUPPORT A DEEP MID/UPPER LVL TROF ACRS OUR CWA THRU THE
WEEKEND. THIS SYNOPTIC SCALE FEATURE WL RESULT IN BLW NORMAL TEMPS
AND CHCS FOR SHOWERS THRU SAT AFTN. FCST FOCUS WL BE TIMING
INDIVIDUAL S/W`S IN THE WEST TO NORTHWEST FLW ALOFT. POTENT 5H
VORT IS EXPECTED TO IMPACT OUR CWA BTWN 06Z AND 15Z FRIDAY
NIGHT/SATURDAY MORNING...WITH STRONG DYNAMICS AND SOME 850 TO
500MB RH PRESENT. GIVEN THE PROGGED LARGE SCALE ASCENT ASSOCIATED
WITH THIS FEATURE...WOULD NOT BE SURPRISED FOR A FEW ISOLATED
STORMS...ON FRIDAY NIGHT/SATURDAY MORNING. THIS ENERGY WL LIFT NE
OF OUR CWA BY 15Z SATURDAY...WITH MUCH DRIER AIR AND LARGE SCALE
SUBSIDENCE DEVELOPING. THINKING AREAL COVERAGE/INTENSITY OF
SHOWERS WL BE LIMITED ON SAT AFTN...DUE TO DRYING ALOFT AND PWS
FALLING BTWN 0.50 AND 0.75". WL MENTION SCHC VALLEYS TO CHC POPS
MTNS. SOUNDING PROFILES SHOW VERY MODEST CAPE/INSTABILITY WITH
VALUES BTWN 200-400 J/KG. FOR FRIDAY NIGHT TIME PERIOD...WL
MENTION HIGH CHC POPS WITH SOME LOW LIKELY POPS NORTHERN DACKS.
QPF WL RANGE BTWN 0.10 AND 0.25". PROGGED 85H TEMPS REMAIN BTWN
10-12C ON SAT...SUPPORTING SLIGHTLY BLW NORMAL TEMPS MAINLY 60S
MTNS TO 70S VALLEYS. ON SUNDAY...MID/UPPER LVL TROF SHARPENS ACRS
OUR FA...AS ANOTHER POTENT VORT AND SFC COLD FRNT IMPACT THE
REGION. GFS/NAM AND ECMWF SHOW BETTER MOISTURE PROFILES ACRS OUR
FA...ALONG WITH GREATER COVERAGE IN QPF. WL MENTION HIGH CHC POPS
ATTM...BUT AN INCREASE TO LIKELY POPS MAYBE NEEDED IF CRNT TRENDS
CONT. HIGHEST POPS AND QPF WL BE ACRS THE MTN AREAS...WITH
RAINFALL AMOUNTS BTWN 0.10 AND 0.25". SOUNDINGS SHOW LIMITED
INSTABILITY WITH CAPE VALUES ONLY BTWN 100 AND 300 J/KG...WL NOT
MENTION THUNDER ATTM. 85H TEMPS DROP SEVERAL DEGREES FROM SATURDAY
AND SUPPORT HIGHS U50S/L60S MTNS/NEK TO M60S TO L70S VALLEYS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 410 AM EDT FRIDAY...PRONOUNCED NORTHWEST FLOW ALOFT ON THE
BACKSIDE OF DEPARTING UPPER TROUGH WILL BRING COOLER AND DRIER
WEATHER TO THE AREA SUNDAY NIGHT INTO MONDAY. COLD AIR ADVECTION
ON MONDAY SUGGESTS HIGHS ONLY IN THE UPPER 60S TO THE MID
70S...WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR. DRY WEATHER CONTINUES MONDAY NIGHT INTO TUESDAY AS
FLOW ALOFT REMAINS FROM THE NORTHWEST. TEMPERATURES BEGIN TO
SLOWLY MODERATE WITH HIGH TEMPERATURES 2 TO 4 DEGREES WARMER THAN
MONDAY. THE TREND TOWARD MORE NORMAL TEMPERATURES BEGINS ON
WEDNESDAY AS FLOW ALOFT BACKS TO THE WEST AND ALLOWS FOR WARM AIR
ADVECTION TO TAKE PLACE. HIGHS WILL BE IN THE 70S TO AROUND 80
BOTH WEDNESDAY AND THURSDAY. THE WESTERLY FLOW ALOFT WILL ALLOW
FOR A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY. AS A RESULT...THE THREAT FOR SHOWERS WILL
RETURN AND WILL MENTION A CHANCE OF SHOWERS ON BOTH DAYS.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...EXPECT SHARP CHANGES IN CONDITIONS ACROSS
THE AREA THROUGH 12Z DUE TO LOW CLOUDS AND FOG. MID AND HIGH LEVEL
CLOUDS ARE GRADUALLY SHIFTING EAST EARLY THIS MORNING AND WHEREVER
THERE HAS BEEN SOME CLEARING...LOW CLOUDS AND FOG HAVE DEVELOPED.
THUS THROUGH 12Z YOU CAN GENERALLY EXPECT VFR/MVFR CONDITIONS...BUT
PERIODS OF LIFR/VLIFR CONDITIONS. AFTER 12Z...VFR CONDITIONS
SHOULD DEVELOP ALL AREAS QUICKLY AS SOUTH TO SOUTHWEST WINDS
INCREASE AND PROVIDE ENOUGH MIXING TO GET RID OF THE LOW CLOUDS
AND FOG. AN UPPER LEVEL DISTURBANCE COMBINED WITH AN INCREASINGLY
UNSTABLE ATMOSPHERE SUGGESTS SCATTERED SHOWERS AND A FEW
THUNDERSTORMS WILL DEVELOP OVER THE AREA AFTER 16Z AND CONTINUE
THROUGH THE REMAINDER OF THE PERIOD. EXPECT VFR/MVFR CONDITIONS
FROM 16Z THROUGH THE REMAINDER OF THE PERIOD.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...
06Z SATURDAY THROUGH 06Z MONDAY...SERIES OF UPPER LEVEL
DISTURBANCES WILL BRING SHOWERS TO THE REGION AT TIMES ALONG WITH
WIDELY SCATTERED STORMS. CONDITIONS LOWERING AT TIMES TO MVFR.
06Z MONDAY THROUGH 00Z WEDNESDAY...VFR CONDITIONS WITHIN A RIDGE
OF SFC HIGH PRESSURE.
&&
.EQUIPMENT...
AS OF 1100 PM EDT THURSDAY...NOAA WEATHER RADIO WXM 44...BROADCASTING
FROM THE TOP OF MOUNT ASCUTNEY VERMONT...WILL BE OFF THE AIR UNTIL
FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/RJS
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1013 AM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1014 AM CDT FRI AUG 2 2013
HIGH PRESSURE WILL CONTINUE TO BUILD SOUTH FROM CANADA TODAY.
UPPER LEVEL IMPULSES ROTATING AROUND NORTHWEST U.S. UPPER LOW WILL
KEEP PRECIPITATION CHANCES OVER THE WEST TODAY...BUT WITH SURFACE
HIGH PRESSURE BUILDING SOUTH...PRECIPITATION WILL HAVE A HARD TIME
MAKING IT INTO CENTRAL NORTH DAKOTA...ESPECIALLY THE NORTH
CENTRAL. HAVE UPDATED POPS TO LIMIT PRECIPITATION CHANCES EAST OF
THE HIGHWAY 83 CORRIDOR. TEMPERATURES LOOK IN LINE BUT WILL TAKE A
CLOSER LOOK AROUND MIDDAY.
UPDATE ISSUED AT 629 AM CDT FRI AUG 2 2013
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ADJUSTED
THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. THE UPDATED GRIDDED
AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI AUG 2 2013
MAIN CONCERNS IN THE SHORT TERM WILL BE EXTENT/PLACEMENT OF SHOWERS
AND THUNDERSTORMS...AS FORECAST MODELS DIFFER ON HOW PRECIPITATION
FIELD WILL PLAY OUT.
CURRENTLY...SURFACE HIGH PRESSURE WAS CENTERED OVER NORTHERN
SASKATCHEWAN WITH THE RIDGE AXIS EXTENDING SOUTHEASTWARD ACROSS
NORTH CENTRAL AND EASTERN NORTH DAKOTA. MEANWHILE LOW PRESSURE WAS
CENTERED OVER WYOMING. AT UPPER LEVELS...A LOW/TROUGH WAS OVER THE
ROCKIES NEAR IDAHO/WESTERN MONTANA WITH SHORTWAVE ENERGY MOVING
THROUGH THE SOUTHWEST FLOW ALOFT OVER CENTRAL/EASTERN MONTANA. A
CLUSTER OF THUNDERSTORMS OVER SOUTHEASTERN MONTANA MOVED INTO
NORTHWESTERN SOUTH DAKOTA AND SOUTHWESTERN NORTH DAKOTA...ASSOCIATED
WITH THE UPPER LEVEL ENERGY IMPULSES. AS THE CONVECTION MOVED
EASTWARD IT ENTERED A MORE STABLE ENVIRONMENT OVER NORTH
DAKOTA...WHERE EFFECTIVE BULK SHEAR WAS LOW AND MOST UNSTABLE CAPE
WAS MINIMAL. THOUGH SHOWERS WERE OCCURRING IN SOUTHWESTERN NORTH
DAKOTA - LIGHTNING ACTIVITY HAD DECREASED GREATLY.
THE SREF SEEMS TO HAVE BEST CAPTURED CURRENT EXTENT OF SHOWERS OVER
THE DAKOTAS. THIS MODEL DEPICTS PRECIPITATION AREA EXPANDING
NORTHWARD AND EASTWARD INTO NORTH DAKOTA...SPREADING AS FAR AS MINOT
AND JAMESTOWN. HOWEVER THIS MODEL IS BULLISH REGARDING THE STRENGTH
OF THE UPPER LEVEL SHORTWAVE IMPULSES OVERCOMING THE LIMITING
FACTORS OF THE UPPER LEVEL RIDGE AND LACK OF ROBUST LOW LEVEL
MOISTURE. THE NAM AND GFS KEEP THE AREA OF PRECIPITATION MORE
CONFINED TO THE SOUTHWEST AND FAR SOUTH CENTRAL...MAINLY SOUTH OF
WILLISTON AND BISMARCK. THE RUC DEPICTS PRECIPITATION REMAINING WEST
AND SOUTH OF THE STATE UNTIL THIS AFTERNOON.
THE UPPER LEVEL SHORTWAVE ENERGY IS MOVING TOWARDS NORTH DAKOTA IN
SOUTHWEST FLOW ALOFT...EMERGING FROM THE AFOREMENTIONED ROCKIES
LOW/TROUGH...AND MOVING INTO THE DOWNSTREAM UPPER RIDGE OVER THE
WESTERN DAKOTAS. A STRONG HUDSON BAY LOW IS EXPECTED TO REMAIN
FAIRLY STATIONARY...KEEPING THE UPPER RIDGE IN PLACE. ALSO A DRY
SURFACE HIGH OVER SOUTH CENTRAL CANADA AND EXTENDING INTO THE
EASTERN DAKOTAS AND MINNESOTA WILL KEEP SURFACE DEWPOINTS IN THE
LOWER 50S AND LIMITING THE AVAILABLE LOW LEVEL MOISTURE.
THUS WILL KEEP HIGHER CHANCES IN THE FAR SOUTHWEST TODAY AND LESSER
CHANCES NORTHEASTWARD. SOME AFTERNOON HEATING MAY INCREASE THE
OVERALL INSTABILITY ACROSS THE REGION...BUT NO SEVERE STORMS ARE
ANTICIPATED IN NORTH DAKOTA. WILL KEEP SOME CHANCES OF
SHOWERS/THUNDER FOR TONIGHT AS WELL...BUT THE UPPER LEVEL RIDGE
BUILDS DURING THE NIGHT AND LESSEN THE CHANCES FOR PRECIPITATION.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI AUG 2 2013
VERY WEAK MID-LEVEL RIDGING NUDGING INTO THE NORTHERN PLAINS IS
PROGGED TO KEEP MOST OF THE REGION DRY SATURDAY. AN APPROACHING
SHORTWAVE WARRANTS MAINTAINING SLIGHT CHANCE POPS IN THE EXTREME
WEST SATURDAY.
THE AFOREMENTIONED SHORTWAVE IS FORECAST TO PUSH ACROSS THE REGION
SATURDAY NIGHT INTO SUNDAY. MAINTAINED HIGH-END CHANCE POPS FOR THIS
PERIOD AS UPPER FORCING APPEARS SUFFICIENT FOR CONVECTIVE
DEVELOPMENT. BOTH THE 00Z GFS/ECWMF PROG INCREASING MUCAPE VALUES
OVER SOUTHWESTERN AND SOUTHCENTRAL NORTH DAKOTA SUNDAY AFTERNOON.
HOWEVER...THE GREATEST MUCAPE VALUES (SOUTHWEST/SOUTHCENTRAL) ARE
DISPLACED FROM THE BEST UPPER LEVEL FORCING (EAST). WILL THEREFORE
KEEP SEVERE MENTION OUT OF THE ZONES AND HWO FOR NOW...BUT WILL
CONTINUE TO MONITOR FUTURE RUNS.
THE PERSISTENT NORTHWESTERLY FLOW ALOFT WILL MAINTAIN SLIGHT CHANCES
FOR PRECIP DAILY THROUGH THE END OF THE PERIOD. THE 00Z GFS/ECMWF
CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL LOW OVER HUDSON
BAY MONDAY DROPPING SOUTH ACROSS SOUTH CANADA AND POSSIBLY INTO THE
FAR NORTH CENTRAL CONUS NEXT WEDNESDAY THROUGH FRIDAY. IF THESE
SOLUTIONS VERIFY...THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL
TEMPERATURES DURING THE LATTER HALF OF NEXT WEEK. THE RAW GFS/ECMWF
MODEL SOLUTIONS PAINT HIGHS IN THE MID 60S (HIGHS IN THE MID 80S ARE
NORMAL FOR EARLY AUGUST) BY THURSDAY AUGUST 8. FOR NOW WILL CONTINUE
TO GO WITH A CONSERVATIVE BLENDED APPROACH AND FORECAST HIGHS IN THE
MID 70S FOR DAY 7 DUE TO THE UNCERTAINTY WITH FORECASTING OUT THAT
FAR IN ADVANCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1014 AM CDT FRI AUG 2 2013
AT 10 AM CDT...SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED OVER
CENTRAL NORTH DAKOTA WITH LOW PRESSURE IN WYOMING. AN UPPER LEVEL
SHORTWAVE WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORMS OVER
EASTERN MONTANA AND WESTERN NORTH DAKOTA. WILL KEEP A MENTION OF
THUNDER AT KDIK TODAY AND SHOWERS AT KISN. WILL NOT MENTION ANY
PRECIPITATION AT KMOT...KBIS AND KJMS. HIGH PRESSURE WILL BUILD
OVER THE AREA TONIGHT ENDING THE THREAT OF ANY SHOWERS IN THE WEST
AS WELL.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
629 AM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 629 AM CDT FRI AUG 2 2013
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ADJUSTED
THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. THE UPDATED GRIDDED
AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI AUG 2 2013
MAIN CONCERNS IN THE SHORT TERM WILL BE EXTENT/PLACEMENT OF SHOWERS
AND THUNDERSTORMS...AS FORECAST MODELS DIFFER ON HOW PRECIPITATION
FIELD WILL PLAY OUT.
CURRENTLY...SURFACE HIGH PRESSURE WAS CENTERED OVER NORTHERN
SASKATCHEWAN WITH THE RIDGE AXIS EXTENDING SOUTHEASTWARD ACROSS
NORTH CENTRAL AND EASTERN NORTH DAKOTA. MEANWHILE LOW PRESSURE WAS
CENTERED OVER WYOMING. AT UPPER LEVELS...A LOW/TROUGH WAS OVER THE
ROCKIES NEAR IDAHO/WESTERN MONTANA WITH SHORTWAVE ENERGY MOVING
THROUGH THE SOUTHWEST FLOW ALOFT OVER CENTRAL/EASTERN MONTANA. A
CLUSTER OF THUNDERSTORMS OVER SOUTHEASTERN MONTANA MOVED INTO
NORTHWESTERN SOUTH DAKOTA AND SOUTHWESTERN NORTH DAKOTA...ASSOCIATED
WITH THE UPPER LEVEL ENERGY IMPULSES. AS THE CONVECTION MOVED
EASTWARD IT ENTERED A MORE STABLE ENVIRONMENT OVER NORTH
DAKOTA...WHERE EFFECTIVE BULK SHEAR WAS LOW AND MOST UNSTABLE CAPE
WAS MINIMAL. THOUGH SHOWERS WERE OCCURRING IN SOUTHWESTERN NORTH
DAKOTA - LIGHTNING ACTIVITY HAD DECREASED GREATLY.
THE SREF SEEMS TO HAVE BEST CAPTURED CURRENT EXTENT OF SHOWERS OVER
THE DAKOTAS. THIS MODEL DEPICTS PRECIPITATION AREA EXPANDING
NORTHWARD AND EASTWARD INTO NORTH DAKOTA...SPREADING AS FAR AS MINOT
AND JAMESTOWN. HOWEVER THIS MODEL IS BULLISH REGARDING THE STRENGTH
OF THE UPPER LEVEL SHORTWAVE IMPULSES OVERCOMING THE LIMITING
FACTORS OF THE UPPER LEVEL RIDGE AND LACK OF ROBUST LOW LEVEL
MOISTURE. THE NAM AND GFS KEEP THE AREA OF PRECIPITATION MORE
CONFINED TO THE SOUTHWEST AND FAR SOUTH CENTRAL...MAINLY SOUTH OF
WILLISTON AND BISMARCK. THE RUC DEPICTS PRECIPITATION REMAINING WEST
AND SOUTH OF THE STATE UNTIL THIS AFTERNOON.
THE UPPER LEVEL SHORTWAVE ENERGY IS MOVING TOWARDS NORTH DAKOTA IN
SOUTHWEST FLOW ALOFT...EMERGING FROM THE AFOREMENTIONED ROCKIES
LOW/TROUGH...AND MOVING INTO THE DOWNSTREAM UPPER RIDGE OVER THE
WESTERN DAKOTAS. A STRONG HUDSON BAY LOW IS EXPECTED TO REMAIN
FAIRLY STATIONARY...KEEPING THE UPPER RIDGE IN PLACE. ALSO A DRY
SURFACE HIGH OVER SOUTH CENTRAL CANADA AND EXTENDING INTO THE
EASTERN DAKOTAS AND MINNESOTA WILL KEEP SURFACE DEWPOINTS IN THE
LOWER 50S AND LIMITING THE AVAILABLE LOW LEVEL MOISTURE.
THUS WILL KEEP HIGHER CHANCES IN THE FAR SOUTHWEST TODAY AND LESSER
CHANCES NORTHEASTWARD. SOME AFTERNOON HEATING MAY INCREASE THE
OVERALL INSTABILITY ACROSS THE REGION...BUT NO SEVERE STORMS ARE
ANTICIPATED IN NORTH DAKOTA. WILL KEEP SOME CHANCES OF
SHOWERS/THUNDER FOR TONIGHT AS WELL...BUT THE UPPER LEVEL RIDGE
BUILDS DURING THE NIGHT AND LESSEN THE CHANCES FOR PRECIPITATION.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI AUG 2 2013
VERY WEAK MID-LEVEL RIDGING NUDGING INTO THE NORTHERN PLAINS IS
PROGGED TO KEEP MOST OF THE REGION DRY SATURDAY. AN APPROACHING
SHORTWAVE WARRANTS MAINTAINING SLIGHT CHANCE POPS IN THE EXTREME
WEST SATURDAY.
THE AFOREMENTIONED SHORTWAVE IS FORECAST TO PUSH ACROSS THE REGION
SATURDAY NIGHT INTO SUNDAY. MAINTAINED HIGH-END CHANCE POPS FOR THIS
PERIOD AS UPPER FORCING APPEARS SUFFICIENT FOR CONVECTIVE
DEVELOPMENT. BOTH THE 00Z GFS/ECWMF PROG INCREASING MUCAPE VALUES
OVER SOUTHWESTERN AND SOUTHCENTRAL NORTH DAKOTA SUNDAY AFTERNOON.
HOWEVER...THE GREATEST MUCAPE VALUES (SOUTHWEST/SOUTHCENTRAL) ARE
DISPLACED FROM THE BEST UPPER LEVEL FORCING (EAST). WILL THEREFORE
KEEP SEVERE MENTION OUT OF THE ZONES AND HWO FOR NOW...BUT WILL
CONTINUE TO MONITOR FUTURE RUNS.
THE PERSISTENT NORTHWESTERLY FLOW ALOFT WILL MAINTAIN SLIGHT CHANCES
FOR PRECIP DAILY THROUGH THE END OF THE PERIOD. THE 00Z GFS/ECMWF
CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL LOW OVER HUDSON
BAY MONDAY DROPPING SOUTH ACROSS SOUTH CANADA AND POSSIBLY INTO THE
FAR NORTH CENTRAL CONUS NEXT WEDNESDAY THROUGH FRIDAY. IF THESE
SOLUTIONS VERIFY...THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL
TEMPERATURES DURING THE LATTER HALF OF NEXT WEEK. THE RAW GFS/ECMWF
MODEL SOLUTIONS PAINT HIGHS IN THE MID 60S (HIGHS IN THE MID 80S ARE
NORMAL FOR EARLY AUGUST) BY THURSDAY AUGUST 8. FOR NOW WILL CONTINUE
TO GO WITH A CONSERVATIVE BLENDED APPROACH AND FORECAST HIGHS IN THE
MID 70S FOR DAY 7 DUE TO THE UNCERTAINTY WITH FORECASTING OUT THAT
FAR IN ADVANCE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 629 AM CDT FRI AUG 2 2013
AT 6 AM CDT...SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED OVER
CENTRAL/EASTERN NORTH DAKOTA WITH LOW PRESSURE IN WYOMING. AN UPPER
LEVEL SHORTWAVE WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORMS OVER
EASTERN MONTANA AND WESTERN SOUTH DAKOTA. MORE SHOWERS AND
THUNDERSTORMS EXPECTED TO MOVE INTO SOUTHWESTERN NORTH DAKOTA AFT
12Z. THE THREAT TO KDIK LOOKS TO LINGER FOR MUCH OF THE DAY WITH
INSTABILITY REMAINING FOR MUCH OF THE DAYTIME HOURS AS UPPER LEVEL
IMPULSES SLOWLY MOVE EAST ACROSS THE STATE. THE FARTHER EAST THE
UPPER IMPULSES GO IN NORTH DAKOTA...THE MORE STABLE THE
ATMOSPHERE...THUS DID NOT INCLUDE ANY MENTION OF SHOWERS OR THUNDER
AT KMOT OR KJMS. DID BRING MENTION OF SHOWERS AT KISN AT 15Z AND AT
KBIS AT 18Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...JV
LONG TERM...TM
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1031 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE PASSES TODAY. ANOTHER COLD FRONT MOVES SOUTHEAST AND
PASSES THROUGH SATURDAY NIGHT. HIGH PRESSURE BUILDS BACK ON SUNDAY
WITH DRIER AIR INTO MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE....
NO CHANGES TO FCST NEEDED THIS MORNING. COMPLEX UPSTREAM ACROSS N
IND SHOULD CONT TO WEAKEN AS IT DROPS SE THIS AFTN. KEPT SE OH POP
FREE FOR AFTN. THINK ANY SHRA WILL HOLD OFF UNTIL THIS EVE.
PREVIOUS DISCUSSION BELOW...
VORT MAX CURRENTLY MOVING THROUGH PA PROVIDING JUST AN ISOLATED
SHOWER RIGHT ALONG NORTHERN CWA BORDER. OTHERWISE...SURFACE HIGH
PRESSURE WILL BE IN CONTROL TODAY. DESPITE VERY LIMITED MID LEVEL
MOISTURE...EXPECT AT LEAST A FEW CUMULUS CLOUDS DRIFTING AROUND
TODAY...WITH CIRRUS DECK INCREASING FROM WEST TO EAST THIS
AFTERNOON IN ADVANCE OF THE NEXT SYSTEM...AN APPROACHING COLD
FRONT AND UPPER LEVEL SHORT WAVE. HAVE POPS ENTERING FROM NW AFTER
00Z TONIGHT...WITH COLD FRONT REMAINING NORTH THROUGH THE ENTIRE
NEAR TERM PERIOD. LATEST NAM/GFS/ECMWF KEEP MOST OF THE ACTIVITY
NORTH OF CWA THROUGH THIS NEAR TERM...SO KEEP CHANCE POPS LIMITED
TO NORTHERN TIER OF COUNTIES...WITH SLIGHT CHANCE A BIT FARTHER
SOUTH. 06Z RAP HINTS AT A CONVECTIVE COMPLEX DEVELOPING OVER NW
OHIO THIS AFTERNOON...AND STEERING FLOW WOULD BRING THIS INTO
NORTHERN WV AS WELL. ONLY MINIMAL CHANGES MADE TO TEMPS...WITH
HIGHS AND LOWS NEAR TO JUST BELOW NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
00Z GFS CONTINUES TO SHOW VERY LITTLE INSTABILITY ON SATURDAY AHEAD
OF THE FRONT. LEANING MORE TOWARD THE 00Z NAM...THAT SHOWS A BIT
MORE INSTABILITY BUT STILL HAS A WARM LAYER AROUND 12 TO 15 THSD
FT. YET...THE NAM SEEM TO UNDERDO THE CONVECTIVE PCPN.
OF COURSE...THE MOST INSTABILITY ON SATURDAY WILL REMAIN TO OUR
SOUTHWEST...TOWARD WESTERN KENTUCKY...WESTERN TENNESSEE...ARKANSAS
VICINITY.
THE PRECIPITABLE WATER DOES PEAK AROUND 1.6 TO 1.8 AHEAD OF THE
FRONT IN OUR VICINITY. STILL MAY HAVE TO WATCH SOME EAST TO WEST
TRAINING...BUT WITH 25 TO 30 KNOT STEERING FLOW...WILL NOT INSERT A
WATER HAZARD INTO THE HAZARDOUS WEATHER POTENTIAL AS OF NOW. WILL
EVALUATE AGAIN TODAY.
BASING FORECAST ON FRONT NEAR MGW TO PKB TO ILN AROUND 03Z
SUNDAY...THEN REACHING SOUTH OF EKN AND CRW BY 09Z AND NR BLF AND SW
VA BY 12Z SUNDAY.
YET...STILL TOUGH TO FIGURE HOW QUICKLY TO INCREASE POPS DURING THE
DAY ON SATURDAY FURTHER SOUTH...AWAY FRONT THE FRONT...IN THE
HTS-CRW-BKW REGION. THIS ALSO CAUSES CONFIDENCE TO DROP IN
PREDICTING MAXIMUM TEMPERATURES SATURDAY AFTERNOON.
AHEAD OF THE FRONT...WILL KEEP OUR MAX POP AROUND 60 PERCENT
DROPPING DOWN INTO CENTRAL WV 00Z TO 06Z SUNDAY...BUT WILL NOT
DROP THESE LIKELY POPS FURTHER SOUTH...INTO EXTREME SOUTHERN WEST
VIRGINIA DURING THE PREDAWN HOURS. EXCEPT FOR THE FRONT...NOT MUCH
SUPPORT THAT FAR SOUTH.
MEANWHILE...NORTH OF THE FRONT...WAS FASTER LOWERING POPS 06Z TO 12Z
SUNDAY.
THINKING LINGERING OVERCAST AND A FEW SHOWERS POSSIBLE SUNDAY
MORNING IN OUR SOUTH. OTHERWISE DRIER AIR ADVECTS SOUTH DURING THE
DAY.
COOLER SUNDAY NIGHT. FIGURING ON SOME LATE NIGHT FOG MAINLY EKN-CRW
ON SOUTH.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
BROAD TROUGHING OVER THE EASTERN HALF OF THE US FROM A LARGE UPPER
LOW IN CANADA WILL KEEP TEMPERATURES A BIT BELOW NORMAL WITH DRY
CONDITIONS ON MONDAY. MOISTURE WILL BEGIN INCREASING AGAIN THROUGH
THE DAY TUESDAY WITH ISOLATED SHOWERS OR THUNDERSTORMS POSSIBLE
MAINLY IN THE MOUNTAINS. PRECIPITATION CHANCES WILL INCREASE THROUGH
MID WEEK WITH SCATTERED SHOWERS OR THUNDERSTORMS MOVING THROUGH AT
TIMES BUT HEAVIER PRECIPITATION POTENTIAL WILL REMAIN WELL SOUTH OF
THE AREA.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
FOG HAS BEEN BOUNCING AROUND SOME THIS MORNING...BUT ALL SITES
SHOULD RETURN TO VFR BY 13Z. SOME SCATTERED MID-LEVEL CUMULUS
AROUND DURING THE AFTERNOON TODAY. CIRRUS WILL ALSO BEGIN
STREAMING IN FROM THE WEST THIS AFTERNOON IN ADVANCE OF THE NEXT
SYSTEM. CALM WINDS EARLY THIS MORNING WILL GIVE WAY TO LIGHT
WESTERLY FLOW THIS AFTERNOON. TONIGHT...THICKENING CLOUDS AND SOME
REMAINING FLOW SHOULD KEEP MOST FOG AT BAY. BEST CHANCE WOULD BE
TYPICAL VALLEYS IN THE MOUNTAINS...WHERE CLOUDS WILL REMAIN
THINNER THE LONGEST. EVEN THERE DO NOT THINK DENSE FOG WILL FORM
AND KEPT AT MVFR. THINK ANY PRECIP IMPACTS WILL HOLD OFF UNTIL
DAYTIME SATURDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: DEVELOPMENT OF FOG TONIGHT MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY L H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY L H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z SATURDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY
NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...MZ/30
SHORT TERM...KTB
LONG TERM...JR
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
950 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE TENNESSEE AND LOWER OHIO VALLEY WILL MOVE
SOUTH TODAY AND ALLOW A TROUGH OF LOW PRESSURE TO DROP SOUTHEAST
ACROSS THE AREA TONIGHT AND EARLY SATURDAY. HIGH PRESSURE WILL
MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED TO ADJUST THE CLOUD COVER AND ADD A CHANCE OF SHOWERS TO
NORTHWEST OHIO FOR THIS MORNING. THE SHOWERS OVER EXTREME
NORTHWEST OHIO SHOULD DISSIPATE WITH SO MUCH DRY AIR OVER THE
REGION. STILL A QUESTION HOW QUICKLY THE SHOWERS AND THUNDERSTORMS
WILL DEVELOP THIS AFTERNOON. MANY OF THE MODELS INCLUDING THE HRRR
ARE SLOW. ALSO SOME CONCERN IF THEY COULD BE STRONG TO POSSIBLY
SEVERE. SPC HAS THE AREA IN SEE TEXT AND THIS IS REASONABLE WITH
THE 0-1KM SHEAR INCREASING THIS EVENING. SOME QUESTION HOW HIGH
THE CAPE WILL BE WITH A FAIR AMOUNT OF CLOUDS AROUND. THE STORMS
SHOULD BE MOVING...HOWEVER...SOME MINOR FLOODING OR PONDING CAN
OCCUR. WILL MENTION A THREAT IN THE HAZARDOUS WEATHER OUTLOOK FOR
LATE THIS AFTERNOON AND EVENING.
ORIGINAL...HIGH PRESSURE OVER THE LOWER OHIO AND TENNESSEE
VALLEY WILL WEAKEN TODAY AND ALLOW A COLD FRONT TO DROP ACROSS THE
CENTRAL GREAT LAKES. A SURFACE WAVE WILL DEVELOP ON THE FRONT AND
SHOULD BE NEAR THE THUMB OF MICHIGAN BY EVENING ACCORDING TO THE
NAM. THE GFS AND SREF ARE A BIT WEAKER WITH THIS FEATURE HOWEVER
ALL MODELS INCREASE MOISTURE FROM THE WEST DURING THE LATE MORNING
AND AFTERNOON AHEAD OF THE SYSTEM. RADAR ALREADY SHOWS
SHOWERS/TSTMS ALREADY DEVELOPING INVOF ORD AND HRRR BRINGS PRECIP
INTO WESTERN COUNTIES BY MID/LATE MORNING. INCREASING CAPE SHOWN
ON THE NAM ACCOMPANYING THE MOISTURE SO WOULD EXPECT INCREASING
CHANCES FOR THUNDERSTORMS FROM THE WEST THROUGH THE MID/LATE
MORNING AND INTO THE AFTERNOON. HIGHS GENERALLY 76 TO 81.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THIS EVENING AND OVERNIGHT MODELS SHOW A SHORT WAVE DROPPING
ACROSS THE CENTRAL GREAT LAKES AS THE COLD FRONT DROPS INTO THE
NRN COUNTIES. WITH INGREDIENTS IN PLACE...EXPECTING A DECENT CHANCE
OF PRECIP ACROSS THE AREA THROUGH THE NIGHT AND INTO SATURDAY
MORNING BEFORE TAPERING FROM THE NORTH DURING THE DAY SATURDAY AS
DRY AIR AND HIGH PRESSURE BUILD FROM THE NORTH. FOLLOWED SREF
TIMING WITH A COMPROMISE IN POPS LEAVING LIKELY FOR THE CATEGORY
THROUGH THE NIGHT. WILL BEGIN SATURDAY WITH CHANCE POPS NORTH AND
LIKELY SOUTH AS MODELS START THE DAY WITH DEEP MOISTURE STILL
ACROSS MUCH OF THE AREA AND THE FRONT ALSO STILL ACROSS THE CWA.
SATURDAY NIGHT MOISTURE WILL BE ALL BUT OUT OF THE AREA. WILL HAVE
A SLIGHT CHANCE POP EAST JUST TO COVER ANY LEFTOVER SHOWERS BUT
FOR THE MOST PART EXPECT DRY CONDITIONS. SUNDAY THROUGH MONDAY
EXPECT DRY CONDITIONS WITH HIGH PRESSURE ACROSS THE AREA. MONDAY
NIGHT DID BRING SLIGHT CHANCE POPS BACK TO THE WEST DURING THE
NIGHT AS THE SURFACE HIGH DRIFTS EAST AND THE GFS SHOWS INCREASING
MOISTURE IN A GENERAL OVERRUNNING PATTERN. STILL HOWEVER WOULD
EXPECT MOST WILL REMAIN DRY AS BEST OVERRUNNING/LIFT AND
INSTABILITY WILL REMAIN WELL WEST OF THE AREA. HIGHS GENERALLY
UNREMARKABLE FOR THIS TIME OF YEAR...MOSTLY REACHING 75 TO
80...COOLEST EAST AND WARMEST WEST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HEIGHTS WILL REBOUND SOME ON TUESDAY AS ONE UPPER LOW CURLS
NORTHEAST TOWARDS NOVA SCOTIA AND A SECONDARY ONE DEVELOPS OVER
MANITOBA. THE FLOW ALOFT ACTUALLY BECOMES NEARLY ZONAL ON THE
SOUTHERN PERIPHERY OF THE BROAD UPPER TROUGH EXTENDING ACROSS
CENTRAL AND EASTERN CANADA. TIMING CHANCES OF PRECIPITATION WILL BE
CHALLENGING IN THE EXTENDED AS MODELS STRUGGLE TO RESOLVE SHORTWAVES
MOVING THROUGH THE FLOW ALOFT. TUESDAY LOOKS LIKE A MOSTLY DRY DAY
AS HIGH PRESSURE EXITING TO THE EAST REMAINS IN CONTROL WITH A
FAIRLY DRY AIRMASS. ALTHOUGH MODELS HAVE SHOWN POOR RUN TO RUN
CONTINUITY IN THIS PATTERN...CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE ON WEDNESDAY AS A WARM FRONT IS PULLED OVER THE REGION
AHEAD THE NEXT COLD FRONT THAT PUSHES SOUTH ACROSS THE AREA
THURSDAY. MODELS ARE STARTING TO HINT AT SOME FAIRLY STRONG WARM
ADVECTION AHEAD OF THE FRONT AND TEMPERATURES ON WEDNESDAY(POSSIBLY
LINGERING INTO THURSDAY) MAY NEED TO BE RAISED SEVERAL DEGREES INTO
THE MID 80S. HAVE TRENDED HIGHS UP BUT KEPT THE FORECAST ON THE COOL
SIDE OF MEX GUIDANCE GIVEN THE UNCERTAINTY IN PATTERN EVOLUTION AND
NORTHERN REACH OF THAT WARM FRONT.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
SHOWERS HAVE BEEN EXPANDING ON REGIONAL RADARS ACROSS SW MICHIGAN
AND NW INDIANA. THESE WILL APPROACH TOL/FDY LATER THIS MORNING
ALTHOUGH EXPECT A GENERAL WEAKENING TREND AS THEY TRY TO PUSH EAST
INTO THE RIDGE. DID NOT INCLUDE ANY THUNDER THIS MORNING BUT CAN
NOT ENTIRELY RULE IT OUT.
DEEPER MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE LATER THIS AFTERNOON INTO TONIGHT AHEAD OF AN APPROACHING
COLD FRONT. HAVE INCLUDED TEMPO/PROB GROUP FOR MOST
LOCATIONS...STARTING IN TOL/FDY AT 21Z AND CLE AT 00Z.
THUNDERSTORMS WILL CONTAIN LOCALLY HEAVY RAIN AND SOME STRONGER
WIND GUSTS WITH CONDITIONS DROPPING TO MVFR/IFR IN THE HEAVIER SHOWERS
AT TIMES. WINDS WILL ALSO BE RATHER BREEZY DURING THE AFTERNOON AS
A 35-40 KNOT LOW LEVEL JET DEVELOPS ALOFT. SURFACE WINDS MAY GUST
TO 25-30 KNOTS DURING THE LATE AFTERNOON...WITH THE STRONGEST
WINDS EXPECTED AT TOL/FDY/CLE.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH
SHOWERS/STORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE FROM WEST TO EAST ACROSS THE LAKE
INTO THIS EVENING AHEAD OF THE NEXT FRONT THAT WILL PUSH SOUTH
ACROSS THE LAKE OVERNIGHT. WINDS WILL APPROACH 20 KNOTS ON THE EAST
HALF OF THE LAKE FOR A FEW HOURS WITH WAVES APPROACHING 4 FEET.
ALTHOUGH SOMEWHAT MARGINAL...A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR A PERIOD OF TIME ON THE EAST END OF THE LAKE TONIGHT.
WINDS WILL VEER AROUND TO THE NORTHWEST ON SATURDAY BEHIND THE FRONT
BUT WILL GENERALLY BE AROUND 10 KNOTS AS THE TROUGH LINGERS IN THE
VICINITY OF THE LAKE...INCREASING ON SUNDAY AS A SECONDARY COLD
FRONT PUSHES SOUTH. HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE
GREAT LAKES FROM MONDAY INTO TUESDAY WITH IMPROVING MARINE
CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...KIELTYKA/TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
745 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE TENNESSEE AND LOWER OHIO VALLEY WILL MOVE
SOUTH TODAY AND ALLOW A TROUGH OF LOW PRESSURE TO DROP SOUTHEAST
ACROSS THE AREA TONIGHT AND EARLY SATURDAY. HIGH PRESSURE WILL
MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...FORECAST ON TRACK. MADE ONLY MINOR UPDATES TO SKY GRIDS
BASED ON SATELLITE TRENDS.
ORIGINAL...HIGH PRESSURE OVER THE LOWER OHIO AND TENNESSEE
VALLEY WILL WEAKEN TODAY AND ALLOW A COLD FRONT TO DROP ACROSS THE
CENTRAL GREAT LAKES. A SURFACE WAVE WILL DEVELOP ON THE FRONT AND
SHOULD BE NEAR THE THUMB OF MICHIGAN BY EVENING ACCORDING TO THE
NAM. THE GFS AND SREF ARE A BIT WEAKER WITH THIS FEATURE HOWEVER
ALL MODELS INCREASE MOISTURE FROM THE WEST DURING THE LATE MORNING
AND AFTERNOON AHEAD OF THE SYSTEM. RADAR ALREADY SHOWS
SHOWERS/TSTMS ALREADY DEVELOPING INVOF ORD AND HRRR BRINGS PRECIP
INTO WESTERN COUNTIES BY MID/LATE MORNING. INCREASING CAPE SHOWN
ON THE NAM ACCOMPANYING THE MOISTURE SO WOULD EXPECT INCREASING
CHANCES FOR THUNDERSTORMS FROM THE WEST THROUGH THE MID/LATE
MORNING AND INTO THE AFTERNOON. HIGHS GENERALLY 76 TO 81.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THIS EVENING AND OVERNIGHT MODELS SHOW A SHORT WAVE DROPPING
ACROSS THE CENTRAL GREAT LAKES AS THE COLD FRONT DROPS INTO THE
NRN COUNTIES. WITH INGREDIENTS IN PLACE...EXPECTING A DECENT CHANCE
OF PRECIP ACROSS THE AREA THROUGH THE NIGHT AND INTO SATURDAY
MORNING BEFORE TAPERING FROM THE NORTH DURING THE DAY SATURDAY AS
DRY AIR AND HIGH PRESSURE BUILD FROM THE NORTH. FOLLOWED SREF
TIMING WITH A COMPROMISE IN POPS LEAVING LIKELY FOR THE CATEGORY
THROUGH THE NIGHT. WILL BEGIN SATURDAY WITH CHANCE POPS NORTH AND
LIKELY SOUTH AS MODELS START THE DAY WITH DEEP MOISTURE STILL
ACROSS MUCH OF THE AREA AND THE FRONT ALSO STILL ACROSS THE CWA.
SATURDAY NIGHT MOISTURE WILL BE ALL BUT OUT OF THE AREA. WILL HAVE
A SLIGHT CHANCE POP EAST JUST TO COVER ANY LEFTOVER SHOWERS BUT
FOR THE MOST PART EXPECT DRY CONDITIONS. SUNDAY THROUGH MONDAY
EXPECT DRY CONDITIONS WITH HIGH PRESSURE ACROSS THE AREA. MONDAY
NIGHT DID BRING SLIGHT CHANCE POPS BACK TO THE WEST DURING THE
NIGHT AS THE SURFACE HIGH DRIFTS EAST AND THE GFS SHOWS INCREASING
MOISTURE IN A GENERAL OVERRUNNING PATTERN. STILL HOWEVER WOULD
EXPECT MOST WILL REMAIN DRY AS BEST OVERRUNNING/LIFT AND
INSTABILITY WILL REMAIN WELL WEST OF THE AREA. HIGHS GENERALLY
UNREMARKABLE FOR THIS TIME OF YEAR...MOSTLY REACHING 75 TO
80...COOLEST EAST AND WARMEST WEST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HEIGHTS WILL REBOUND SOME ON TUESDAY AS ONE UPPER LOW CURLS
NORTHEAST TOWARDS NOVA SCOTIA AND A SECONDARY ONE DEVELOPS OVER
MANITOBA. THE FLOW ALOFT ACTUALLY BECOMES NEARLY ZONAL ON THE
SOUTHERN PERIPHERY OF THE BROAD UPPER TROUGH EXTENDING ACROSS
CENTRAL AND EASTERN CANADA. TIMING CHANCES OF PRECIPITATION WILL BE
CHALLENGING IN THE EXTENDED AS MODELS STRUGGLE TO RESOLVE SHORTWAVES
MOVING THROUGH THE FLOW ALOFT. TUESDAY LOOKS LIKE A MOSTLY DRY DAY
AS HIGH PRESSURE EXITING TO THE EAST REMAINS IN CONTROL WITH A
FAIRLY DRY AIRMASS. ALTHOUGH MODELS HAVE SHOWN POOR RUN TO RUN
CONTINUITY IN THIS PATTERN...CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE ON WEDNESDAY AS A WARM FRONT IS PULLED OVER THE REGION
AHEAD THE NEXT COLD FRONT THAT PUSHES SOUTH ACROSS THE AREA
THURSDAY. MODELS ARE STARTING TO HINT AT SOME FAIRLY STRONG WARM
ADVECTION AHEAD OF THE FRONT AND TEMPERATURES ON WEDNESDAY(POSSIBLY
LINGERING INTO THURSDAY) MAY NEED TO BE RAISED SEVERAL DEGREES INTO
THE MID 80S. HAVE TRENDED HIGHS UP BUT KEPT THE FORECAST ON THE COOL
SIDE OF MEX GUIDANCE GIVEN THE UNCERTAINTY IN PATTERN EVOLUTION AND
NORTHERN REACH OF THAT WARM FRONT.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHOWERS HAVE BEEN EXPANDING ON REGIONAL RADARS ACROSS SW MICHIGAN
AND NW INDIANA. THESE WILL APPROACH TOL/FDY LATER THIS MORNING
ALTHOUGH EXPECT A GENERL WEAKENING TREND AS THEY TRY TO PUSH EAST
INTO THE RIDGE. DID NOT INCLUDE ANY THUNDER THIS MORNING BUT CAN
NOT ENTIRELY RULE IT OUT.
DEEPER MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE LATER THIS AFTERNOON INTO TONIGHT AHEAD OF AN APPROACHING
COLD FRONT. HAVE INCLUDED TEMPO/PROB GROUP FOR MOST
LOCATIONS...STARTING IN TOL/FDY AT 21Z AND CLE AT 00Z.
THUNDERSTORMS WILL CONTAIN LOCALLY HEAVY RAIN AND SOME STRONGER
WIND GUSTS WITH CONDITIONS DROPPING TO MVFR/IFR IN THE HEAVIER SHOWERS
AT TIMES. WINDS WILL ALSO BE RATHER BREEZY DURING THE AFTERNOON AS
A 35-40 KNOT LOW LEVEL JET DEVELOPS ALOFT. SURFACE WINDS MAY GUST
TO 25-30 KNOTS DURING THE LATE AFTERNOON...WITH THE STRONGEST
WINDS EXPECTED AT TOL/FDY/CLE.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH
SHOWERS/STORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE FROM WEST TO EAST ACROSS THE LAKE
INTO THIS EVENING AHEAD OF THE NEXT FRONT THAT WILL PUSH SOUTH
ACROSS THE LAKE OVERNIGHT. WINDS WILL APPROACH 20 KNOTS ON THE EAST
HALF OF THE LAKE FOR A FEW HOURS WITH WAVES APPROACHING 4 FEET.
ALTHOUGH SOMEWHAT MARGINAL...A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR A PERIOD OF TIME ON THE EAST END OF THE LAKE TONIGHT.
WINDS WILL VEER AROUND TO THE NORTHWEST ON SATURDAY BEHIND THE FRONT
BUT WILL GENERALLY BE AROUND 10 KNOTS AS THE TROUGH LINGERS IN THE
VICINITY OF THE LAKE...INCREASING ON SUNDAY AS A SECONDARY COLD
FRONT PUSHES SOUTH. HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE
GREAT LAKES FROM MONDAY INTO TUESDAY WITH IMPROVING MARINE
CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
642 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE TENNESSEE AND LOWER OHIO VALLEY WILL MOVE
SOUTH TODAY AND ALLOW A TROUGH OF LOW PRESSURE TO DROP SOUTHEAST
ACROSS THE AREA TONIGHT AND EARLY SATURDAY. HIGH PRESSURE WILL
MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...FORECAST ON TRACK. MADE ONLY MINOR UPDATES TO SKY GRIDS
BASED ON SATELLITE TRENDS.
ORIGINAL...HIGH PRESSURE OVER THE LOWER OHIO AND TENNESSEE
VALLEY WILL WEAKEN TODAY AND ALLOW A COLD FRONT TO DROP ACROSS THE
CENTRAL GREAT LAKES. A SURFACE WAVE WILL DEVELOP ON THE FRONT AND
SHOULD BE NEAR THE THUMB OF MICHIGAN BY EVENING ACCORDING TO THE
NAM. THE GFS AND SREF ARE A BIT WEAKER WITH THIS FEATURE HOWEVER
ALL MODELS INCREASE MOISTURE FROM THE WEST DURING THE LATE MORNING
AND AFTERNOON AHEAD OF THE SYSTEM. RADAR ALREADY SHOWS
SHOWERS/TSTMS ALREADY DEVELOPING INVOF ORD AND HRRR BRINGS PRECIP
INTO WESTERN COUNTIES BY MID/LATE MORNING. INCREASING CAPE SHOWN
ON THE NAM ACCOMPANYING THE MOISTURE SO WOULD EXPECT INCREASING
CHANCES FOR THUNDERSTORMS FROM THE WEST THROUGH THE MID/LATE
MORNING AND INTO THE AFTERNOON. HIGHS GENERALLY 76 TO 81.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THIS EVENING AND OVERNIGHT MODELS SHOW A SHORT WAVE DROPPING
ACROSS THE CENTRAL GREAT LAKES AS THE COLD FRONT DROPS INTO THE
NRN COUNTIES. WITH INGREDIENTS IN PLACE...EXPECTING A DECENT CHANCE
OF PRECIP ACROSS THE AREA THROUGH THE NIGHT AND INTO SATURDAY
MORNING BEFORE TAPERING FROM THE NORTH DURING THE DAY SATURDAY AS
DRY AIR AND HIGH PRESSURE BUILD FROM THE NORTH. FOLLOWED SREF
TIMING WITH A COMPROMISE IN POPS LEAVING LIKELY FOR THE CATEGORY
THROUGH THE NIGHT. WILL BEGIN SATURDAY WITH CHANCE POPS NORTH AND
LIKELY SOUTH AS MODELS START THE DAY WITH DEEP MOISTURE STILL
ACROSS MUCH OF THE AREA AND THE FRONT ALSO STILL ACROSS THE CWA.
SATURDAY NIGHT MOISTURE WILL BE ALL BUT OUT OF THE AREA. WILL HAVE
A SLIGHT CHANCE POP EAST JUST TO COVER ANY LEFTOVER SHOWERS BUT
FOR THE MOST PART EXPECT DRY CONDITIONS. SUNDAY THROUGH MONDAY
EXPECT DRY CONDITIONS WITH HIGH PRESSURE ACROSS THE AREA. MONDAY
NIGHT DID BRING SLIGHT CHANCE POPS BACK TO THE WEST DURING THE
NIGHT AS THE SURFACE HIGH DRIFTS EAST AND THE GFS SHOWS INCREASING
MOISTURE IN A GENERAL OVERRUNNING PATTERN. STILL HOWEVER WOULD
EXPECT MOST WILL REMAIN DRY AS BEST OVERRUNNING/LIFT AND
INSTABILITY WILL REMAIN WELL WEST OF THE AREA. HIGHS GENERALLY
UNREMARKABLE FOR THIS TIME OF YEAR...MOSTLY REACHING 75 TO
80...COOLEST EAST AND WARMEST WEST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HEIGHTS WILL REBOUND SOME ON TUESDAY AS ONE UPPER LOW CURLS
NORTHEAST TOWARDS NOVA SCOTIA AND A SECONDARY ONE DEVELOPS OVER
MANITOBA. THE FLOW ALOFT ACTUALLY BECOMES NEARLY ZONAL ON THE
SOUTHERN PERIPHERY OF THE BROAD UPPER TROUGH EXTENDING ACROSS
CENTRAL AND EASTERN CANADA. TIMING CHANCES OF PRECIPITATION WILL BE
CHALLENGING IN THE EXTENDED AS MODELS STRUGGLE TO RESOLVE SHORTWAVES
MOVING THROUGH THE FLOW ALOFT. TUESDAY LOOKS LIKE A MOSTLY DRY DAY
AS HIGH PRESSURE EXITING TO THE EAST REMAINS IN CONTROL WITH A
FAIRLY DRY AIRMASS. ALTHOUGH MODELS HAVE SHOWN POOR RUN TO RUN
CONTINUITY IN THIS PATTERN...CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE ON WEDNESDAY AS A WARM FRONT IS PULLED OVER THE REGION
AHEAD THE NEXT COLD FRONT THAT PUSHES SOUTH ACROSS THE AREA
THURSDAY. MODELS ARE STARTING TO HINT AT SOME FAIRLY STRONG WARM
ADVECTION AHEAD OF THE FRONT AND TEMPERATURES ON WEDNESDAY(POSSIBLY
LINGERING INTO THURSDAY) MAY NEED TO BE RAISED SEVERAL DEGREES INTO
THE MID 80S. HAVE TRENDED HIGHS UP BUT KEPT THE FORECAST ON THE COOL
SIDE OF MEX GUIDANCE GIVEN THE UNCERTAINTY IN PATTERN EVOLUTION AND
NORTHERN REACH OF THAT WARM FRONT.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
CLEAR SKIES ARE IN PLACE OVER THE REGION TONIGHT WITH SOME BR
DEVELOPING MAINLY NE OHIO BETWEEN 10-13Z. SOME SITES WILL SEE MVFR
AND POSSIBLY IFR VISIBILITIES FOR A FEW HOURS.
MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE AHEAD OF
A FRONT LATE THIS AFTERNOON INTO TONIGHT. HAVE INCLUDED A PROB GROUP
FOR MOST LOCATIONS...STARTING IN TOL/FDY AT 21Z AND CLE AT 00Z.
THUNDERSTORMS WILL CONTAIN LOCALLY HEAVY RAIN AND SOME STRONGER WIND
GUSTS WITH CONDITIONS DROPPING TO IFR IN THE HEAVIER SHOWERS AT
TIMES. WINDS WILL ALSO BE RATHER BREEZY DURING THE AFTERNOON AS A
35-40 KNOT LOW LEVEL JET DEVELOPS ALOFT. SURFACE WINDS MAY GUST
TO 25-30 KNOTS DURING THE LATE AFTERNOON...WITH THE STRONGEST
WINDS EXPECTED AT TOL/FDY/CLE.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH
SHOWERS/STORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE FROM WEST TO EAST ACROSS THE LAKE
INTO THIS EVENING AHEAD OF THE NEXT FRONT THAT WILL PUSH SOUTH
ACROSS THE LAKE OVERNIGHT. WINDS WILL APPROACH 20 KNOTS ON THE EAST
HALF OF THE LAKE FOR A FEW HOURS WITH WAVES APPROACHING 4 FEET.
ALTHOUGH SOMEWHAT MARGINAL...A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR A PERIOD OF TIME ON THE EAST END OF THE LAKE TONIGHT.
WINDS WILL VEER AROUND TO THE NORTHWEST ON SATURDAY BEHIND THE FRONT
BUT WILL GENERALLY BE AROUND 10 KNOTS AS THE TROUGH LINGERS IN THE
VICINITY OF THE LAKE...INCREASING ON SUNDAY AS A SECONDARY COLD
FRONT PUSHES SOUTH. HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE
GREAT LAKES FROM MONDAY INTO TUESDAY WITH IMPROVING MARINE
CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS TULSA OK
649 AM CDT FRI AUG 2 2013
.DISCUSSION...
THE 12Z TAF DISCUSSION IS INCLUDED BELOW.
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VFR CONDITIONS WILL PREVAIL FOR THE MAJORITY OF THE TAF PERIOD.
BETTER TSRA CHANCES WILL BE ACROSS FAR NE OK AND NW AR WHERE
EITHER TEMPO OR VCTS MENTIONS ARE INCLUDED.
LACY
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT FRI AUG 2 2013/
DISCUSSION...
THUNDERSTORM COMPLEX MOVING INTO SOUTHEAST KANSAS LOOKS TO
AFFECT PORTIONS OF NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS
THIS MORNING. THE LAST FEW RUNS OF THE HRRR HAVE BEEN CONSISTENT
WITH BRINGING THIS COMPLEX THROUGH NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS BEFORE IT DISSIPATES. BEST CHANCES OF SHOWERS AND THUNDERSTORMS
THIS MORNING WILL BE ALONG AND NORTH OF HIGHWAY 412. ADDITIONAL SHOWERS
AND THUNDERSTORMS MAY DEVELOP LATER THIS AFTERNOON AND EVENING ALONG
ANY LEFTOVER OUTFLOW BOUNDARIES. WILL NOT ISSUE ANY HEAT HEADLINES TODAY
WITH ONLY A FEW LOCATIONS HITTING CRITERIA THIS AFTERNOON.
THUNDERSTORM COMPLEXES MOVING OUT OF KANSAS WILL AFFECT PORTIONS OF
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS FOR THE NEXT FEW NIGHTS AS
THE AREA REMAINS ON THE EDGE OF THE NORTHWESTERLY FLOW ALOFT. THIS
CHANGES SOMEWHAT TOWARDS MID-WEEK AS THE MID-LEVEL HIGH BUILDS OVER
THE AREA. A FRONTAL BOUNDARY MAKES A RUN INTO THE AREA THURSDAY
INTO FRIDAY AS A MID-LEVEL SHORTWAVE SWEEPS ACROSS THE GREAT LAKES
KEEPING CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 97 78 97 75 / 20 20 20 20
FSM 96 76 98 75 / 10 30 20 20
MLC 98 77 99 75 / 10 20 20 20
BVO 94 76 95 72 / 40 30 20 30
FYV 91 75 92 72 / 20 40 20 20
BYV 88 73 91 72 / 40 50 30 20
MKO 95 75 97 73 / 10 30 20 20
MIO 90 75 93 73 / 50 40 20 30
F10 97 78 98 74 / 10 20 20 20
HHW 98 76 100 75 / 0 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1058 AM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1057 AM CDT FRI AUG 2 2013
LOCATED NEAR PLATTE SD...MCV FROM OVERNIGHT CONVECTION HAS FLARED
UP QUITE AN AREA OF CONVECTION IN THE FSD CWA EARLY THIS
MORNING...AND EVEN ONE BRIEF PULSE TO A SEVERE HAILER IN THE FAR
SOUTHWEST. FOR THE CURRENT TIME... OTHER THAN SOME OF THE AREAS
ON THE SOUTHERN FLANK OF THE COMPLEX WHERE ELEVATED INSTABILITY
IS SOMEWHAT STRONGER...MOST OF THE AREA HAS DEGRADED TO A LARGE
STRATIFORM AREA WITH EMBEDDED CONVECTIVE ELEMENTS. TO SAY THE
SHORT RANGE MODELS HANDLED POORLY WOULD PERHAPS EVEN BE A
COMPLIMENT...OTHER THAN THE HRRR WHICH HAS HAD THE RIGHT
DEVELOPMENT/EVOLUTION TRENDS TO THE SOUTHEAST AREA... BUT DOES
NOT ADEQUATELY ACKNOWLEDGE THE MORE DYNAMICALLY FORCED AREA OF
SHOWERS/CONVECTION ACROSS THE NORTHWEST PORTIONS OF SD.
HAVE BOOSTED POPS CONSIDERABLY ACROSS THE SOUTHWEST 2/3 OF THE
AREA...AND MAY BE ALL BUT THE EXTREME NORTHEAST THAT EVENTUALLY
SEES A FEW SHOWERS...WITH THUNDER LIMITED TO WEST THROUGH SOUTH.
AS FAR AS SEVERE THREAT...APPEARS TO HAVE MOSTLY PASSED...
ALTHOUGH PERHAPS CANNOT IGNORE A MINIMAL THREAT FOR A MARGINAL
HAILER IN THE EXTREME SOUTH/SOUTHWEST DURING THE EARLY TO MID
AFTERNOON ALONG SOUTHERN PERIPHERY OF SECONDARY AREA OF CONVECTION
WHERE WILL HAVE PROXIMITY TO SLIGHTLY BETTER ELEVATED INSTABILITY.
PRECIP AND CLOUDS WILL HAVE A DEVASTATING IMPACT ON TEMPS TODAY...
AND IN ADDITION TO SLOWING THE DIURNAL TREND...SLASHED HIGHS BY
A SOLID 5-8F OVER MUCH OF THE AREA EXCEPT THE FAR EAST/NORTHEAST.
MAY HAVE TO DROP READINGS EVEN FURTHER...AND THIS WOULD BRING SOME
NEAR RECORD COLD HIGHS ONCE AGAIN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT FRI AUG 2 2013
CONFIDENCE ON CONVECTIVE DEVELOPMENT/EVOLUTION IS EXTREMELY LOW FOR
TODAY WITH NOT A SINGLE MODEL HANDLING OVERNIGHT CONVECTION WELL.
CURRENT RADAR SHOWING CONVECTION DEVELOPING OVER WESTERN SOUTH
DAKOTA VERY EARLY THIS MORNING...THOUGH NOT SURE IF ANY OF THIS
ACTIVITY WILL MAKE IT INTO OUR WESTERN ZONES WITH STORM MOTION TO
THE SOUTHEAST AND A MORE STABLE/DRIER ATMOSPHERE OVER OUR AREA. A
STATIONARY BOUNDARY IS SITUATED SOMEWHERE ACROSS THE AREA...THOUGH
VERY HARD TO DEFINE WITH SURFACE OBS...WITH ASSORTED OUTFLOW
BOUNDARIES AROUND THE REGION. THE ASSUMPTION AT THIS POINT IS THAT
MOST CONVECTIVE DEVELOPMENT WILL BE FOCUSED IN THE VICINITY OF THIS
BOUNDARY TODAY...WHERE EVER IT MAY END UP. IT IS PROGGED TO BE
DRAPED ACROSS OUR FAR SOUTH THIS AFTERNOON...SO KEPT THE HIGHER POPS
OVER THAT AREA AND UP THROUGH THE MISSOURI RIVER VALLEY WHERE
PROGGED INSTABILITY WILL BE GREATER. MODELS DO INDICATE THE
ATMOSPHERE BECOMING MORE STABLE THROUGH THE DAY AS BETTER
INSTABILITY IS SHUNTED TO THE SOUTH...SO THINK THAT THE BETTER
CHANCE OF ANY SEVERE WEATHER MAY BE TO THE SOUTH OF OUR CWA. THAT
BEING SAID...THE BEST CHANCE OF SEVERE STORM DEVELOPMENT IF IT WERE
TO OCCUR WOULD BE IN THE AFTERNOON THROUGH OUR LOWER SOUTH
CENTRAL/MISSOURI RIVER ZONES WHERE LINGERING INSTABILITY/STRONG
DIRECTIONAL SHEAR MAY EXIST. MODELS CONTINUE TO COME IN COOLER THAN
PREVIOUS RUNS WITH REGARD TO HIGHS TODAY UNDER AN EASTERLY LOW LEVEL
FLOW...SO DROPPED HIGHS A COUPLE MORE DEGREES...RUNNING GENERALLY
MID AND UPPER 70S...TO AROUND 80 TROUGH OUR SOUTHERN MOST IOWA ZONES.
BY TONIGHT...EXPECT ANY LINGERING THUNDERSTORM ACTIVITY IN OUR SOUTH
TO DIMINISH AS DRIER AIR CONTINUES TO FILTER INTO THE REGION AND THE
STATIONARY BOUNDARY PULLS OUT OF OUR AREA. 925 MB TEMPERATURES COOL
SLIGHTLY OVERNIGHT UNDER A NORTHEASTERLY LOW LEVEL FLOW...WITH LOWS
DROPPING INTO THE MID 50S TO NEAR 60.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI AUG 2 2013
FSD FORECAST AREA WILL BE UNDER THE INFLUENCE OF COOL CANADIAN HIGH
PRESSURE AND EASTERLY LOW LEVEL FLOW...MAKING FOR A COOL EARLY
AUGUST WEEKEND WITH HIGH TEMPS ONLY IN THE 70S. RETURN FLOW SETS UP
ACROSS WESTERN SODAK FOR SATURDAY NIGHT IN RESPONSE TO PAC NW VORT
MAX TRAVERSING THE UPPER RIDGE. MODELS NOW MOSTLY IN AGREEMENT WITH
INSTABILITY AXIS REMAINING SOUTH AND WEST...WITH A 850MB BOUNDARY
SITTING JUST SOUTH OF MO RIVER. HAVE CONCENTRATED HIGHEST CHANCE POPS
ACROSS THE MO RIVER VALLEY AREA AND WEST OF THE JAMES RIVER
ACCORDINGLY...BUT OVERALL HAVE LOWERED POPS FOR SUNDAY/SUNDAY
NIGHT. MUCAPES REMAIN BELOW 1000 J/KG AS WELL FOR SUNDAY SO SEVERE
WEATHER THREAT IS VERY LOW. ASSOCIATED LOW LEVEL COLD FRONT PUSHES
THROUGH SUNDAY OVERNIGHT AND FOR THE FIRST PART OF MONDAY WITH
SOME SCT CONVECTION STILL POSSIBLE.
CONTINUED FAST NORTHWEST FLOW ALOFT BETWEEN CANADIAN CLOSED LOW AND
SOUTHERN CONUS RIDGE WILL CONTINUE TO MAKE CONVECTIVE FORECASTING
VERY CHALLENGING. MODELS PICKING UP ON MORE SIGNIFICANT SHORT
WAVE/FRONT FROM CANADIAN LOW THAT SWINGS THROUGH ON MONDAY NIGHT
THROUGH TUESDAY OR TUESDAY NIGHT PER THE GFS OR ECMWF. LOOKS LIKE
SOME DECENT RETURN FLOW WITH GFS ADVERTISING VERY HIGH MUCAPES FOR
TUESDAY AFTERNOON ACROSS MUCH OF THE FORECAST AREA. DEEP LAYER
SHEAR 50 KTS TUESDAY AFTERNOON MAKES ORGANIZED CONVECTION A
POSSIBILITY. HOWEVER...WITH TIMING AND PLACEMENT ISSUES IN THE
MODELS AS OF LATE...CONFIDENCE OF ANY SEVERE THREAT IS LOW. WILL
MONITOR FOR CONSISTENCY IN SUBSEQUENT MODEL RUNS.
OTHERWISE RETROGRADING UPPER CANADIAN LOW WILL BRING EVEN COOLER
TEMPS FOR THE LATTER HALF OF THE WEEK...ALTHOUGH THE LATEST ECMWF IS
NOT QUITE AS BULLISH WITH THE COLD AIR ADVECTION AS IT WAS
YESTERDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 602 AM CDT FRI AUG 2 2013
SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE WEST
AND SOUTH TODAY...THOUGH CONFIDENCE IN TIMING AND EVOLUTION IS LOW
WITH MODELS HANDLING THE CONVECTION POORLY. CONVECTION MORE LIKELY
TO BRIEFLY AFFECT KHON AND KSUX THAN KFSD...AND ANY HEAVIER
THUNDERSTORM ACTIVITY COULD RESULT IN SHORT LIVED LOWERING OF
CONDITIONS. THERE WILL BE A POSSIBILITY OF MVFR CEILINGS AROUND
KSUX LATER TONIGHT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...JM
LONG TERM...
AVIATION...JM
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
316 PM MDT FRI AUG 2 2013
.SHORT TERM...AS EXPECTED...THE COLD FRONT OUT OF NE/SD HAS MOVED
INTO NORTHEASTERN COLORADO ALREADY...PUSHED QUICKER BY LAST NIGHT
AND THIS MORNINGS CONVECTION UP THERE. THIS IS ABOUT 12 HOURS
AHEAD OF WHAT THE GFS...ECMWF...NAM AND GEM MODELS HAD IT COMING
IN....THE HRRR AND THE RUC MODELS HAVE BEEN SHOWING AN EARLIER
ARRIVAL WITH EACH HOURLY RUN. HAVE ADJUSTED WIND AND WEATHER
GRIDS FOR AN EARLIER ARRIVAL.
A BUILDING UPPER RIDGE CONTINUES TO STRETCH FROM TEXAS NORTHWEST
INTO MONTANA TONIGHT INTO SATURDAY. HIGH SURFACE PRESSURE OVER THE
HIGH NORTHERN PLAINS WILL CONTINUE MOVING SOUTH AND PUSH THE COLD
FRONT FURTHER SOUTH DOWN THE EASTERN PLAINS OF COLORADO. FRONTAL
LIFT WILL CONTINUE PRODUCING ISOLATED SHOWERS AND THUNDERSTORMS
OVER THE PLAINS THROUGH TONIGHT WITH OROGRAPHIC LIFT KEEPING
ISOLATED STORMS GOING OVER THE HIGHER TERRAIN THROUGH THE
EVENING.
HIGHER MOISTURE WILL BE PUSHED IN FROM THE EAST THROUGH
SATURDAY...WITH PRECIPITABLE WATER CURRENTLY AROUND 0.7 INCHES AND
FORECASTED TO INCREASE TO NEAR 1.5 INCHES BY SATURDAY AFTERNOON.
THIS WILL HELP INCREASE CAPES UP TO NEAR 1500 J/KG OVER THE
PLAINS...THEN EASTERLY FLOW AT THE SURFACE TRANSITIONING TO
INCREASING SOUTHERLIES NEAR 700 MB THEN WESTERLIES NEAR 500 MB
WILL PROVIDE ENOUGH SHEAR FOR MAKING THE ENVIRONMENT ABLE TO
PRODUCE AND CARRY STRONGER STORMS. TEMPERATURES WILL BE COOLER AT
THE SURFACE OVER THE FOOTHILLS AND PLAINS TOMORROW WITH LOW 80S
EXPECTED. MOUNTAINS SHOULD STAY ABOVE THIS FRONTAL AIRMASS WITH
SIMILAR TEMPERATURES TO TODAY AND ISOLATED TO SCATTERED
CONVECTION. AREAS ALONG AND EAST OF THE CONTINENTAL DIVIDE WILL
SEE MORE WIDESPREAD SHOWERS AND STORMS WITH THE UPSLOPE FLOW.
RAINFALL AMOUNTS ARE EXPECTED TO BE GREATER WITH THE STRONG STORMS
WHERE A SINGLE STORM COULD PRODUCE HALF AN INCH OR MORE. THESE
STORMS WILL ALSO HAVE THE THREAT OF STRONG WINDS AND LARGE HAIL
UNDER TOMORROWS EXPECTED ENVIRONMENT. NAM MODEL IS AN OUTLIER
WITH THE FRONT AND SURFACE TROUGH MOVING BACK EAST INTO THE PLAINS
WHICH WOULD DRASTICALLY LOWER THE CHANCE OF PRECIPITATION ALONG
THE FOOTHILLS AND METRO AREAS. WITH THIS MODEL BEING THE ONLY ONE
SHOWING THIS PATTERN....WILL DISCOUNT FOR NOW...BUT NOT TOTALLY
DISREGARD THE POSSIBILITY.
.LONG TERM...MID LEVEL SHORTWAVE TO MOVE ACROSS FAR EASTERN PLAINS
SATURDAY EVENING. BEST CHANCE FOR STORMS DURING THE EVENING TO
BE ALONG AND AHEAD OF THE WAVE ACROSS FAR EASTERN PLAINS AND WILL
KEEP THE HIGHER POPS THERE. CAPE VALUES TO DECREASE DURING THE
EVENING TO LESS THAN 1000 J/KG...SO ANY THREAT FOR SEVERE STORMS
SHOULD HAVE ENDED. STILL POTENTIAL FOR STORMS TO PRODUCE BRIEF
HEAVY RAINFALL...ESPECIALLY FAR EASTERN PLAINS AND ALONG
FOOTHILLS. STORMS TO END OVERNIGHT WITH SOME CLEARING. BOUNDARY
LAYER WIND AND HUMIDITY PROGS SUGGEST SOME POTENTIAL FOR FOG OVER
THE FAR NORTHEAST CORNER TOWARDS MORNING. FOR NOW WILL HOLD OFF ON
ADDING ANY FOG. ON SUNDAY...FLOW ALOFT BECOMES A BIT MORE WESTERLY
WITH A SLIGHT DECREASE IN MOISTURE. PRECIPITABLE WATER VALUES
STILL FAIRLY HIGH ACROSS PLAINS WITH VALUES ABOVE AN INCH. STILL
BEST CHANCE FOR STORMS TO BE ACROSS MOUNTAINS AND FOOTHILLS AS
WELL AS ALONG THE PALMER DIVIDE DURING THE AFTERNOON AND EVENING
AS FORECAST SOUNDINGS SHOWING A MID LEVEL CAP OVER MUCH OF THE
PLAINS. THERE ARE SOME HINTS OF THE DEVELOPMENT OF A DENVER
CYCLONE WHICH COULD FOCUS ADDITIONAL STORM DEVELOPMENT EAST OF THE
URBAN CORRIDOR. TEMPERATURES TO BE A FEW DEGREES WARMER...CLOSER
TO NORMAL READINGS. FOR MONDAY...MODELS SHOW WESTERLY FLOW ALOFT
INCREASING WITH UPPER HIGH CENTERED OVER NORTHERN TEXAS. AIRMASS A
BIT DRIER...WITH PRECIPITABLE WATER VALUES AROUND NINE TENTHS OF
AN INCH ACROSS THE PLAINS AND SIX TENTHS OF AN INCH OVER THE
MOUNTAINS. STILL ENOUGH MOISTURE OF A SLIGHT CHANCE OF AFTERNOON
AND EVENING THUNDERSTORMS....MAINLY OVER THE MOUNTAINS. HIGHS TO
BE NEAR NORMAL. ON TUESDAY...CENTER OF UPPER HIGH SHIFTS INTO
EASTERN TEXAS WITH FLOW BECOMING SOUTHWEST. SOME INCREASE IN
SUBTROPICAL MOISTURE DURING THE AFTERNOON...MAINLY ACROSS
MOUNTAINS. BEST CHANCE FOR STORMS TO BE OVER THE HIGH COUNTRY.
HIGHS TO HOVER NEAR NORMAL.
FOR THE LATER DAYS...WEDNESDAY THROUGH FRIDAY: SOUTHWEST FLOW
ALOFT TO PREVAIL WITH UPPER HIGH SHIFTING INTO ARKANSAS BY FRIDAY.
SUBTROPICAL MOISTURE TO INCREASE WEDNESDAY AND THURSDAY WITH A
BETTER CHANCE FOR THUNDERSTORMS. IN ADDITION...MODELS SHOW A FRONT
MOVING ACROSS THE PLAINS WEDNESDAY...INCREASING THE UPSLOPE AND
LOW LEVEL MOISTURE. BY FRIDAY THERE IS SOME HINTS AT THE MOISTURE
DECREASING WITH A MORE STABLE AIRMASS WHICH SHOULD LEAD TO A LOWER
CHANCE FOR THUNDERSTORMS. TEMPERATURES TO COOL TO BELOW NORMAL BY
FRIDAY.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL TODAY WITH LIGHT WINDS.
A SLIGHT CHANCE AT SEEING A THUNDERSTORM LATE THIS AFTERNOON AND
EVENING WITH THE BEST CHANCE OVER THE HIGH TERRAIN AND NEAR THE WY
BORDER. GOOD POSSIBILITY OF OUTFLOW AT THE AREA AIRPORTS FROM
STORMS...REASON FOR VRB20G30KT. A COLD FRONT WILL BE MOVING SOUTH
ACROSS THE AREA TONIGHT WHICH WILL BRING IN HIGHER MOISTURE AND
UPSLOPE FLOW. MUCH MORE WIDESPREAD CONVECTION EXPECTED SATURDAY.
&&
.HYDROLOGY...AIRMASS IS DRIER AND MORE STABLE TODAY LEAVING
ISOLATED COVERAGE OF THUNDERSTORMS THIS AFTERNOON AND EVENING.
MODERATE TO A VERY BRIEF PERIOD OF HEAVY RAIN WILL BE POSSIBLE
FROM THE STORMS THAT DO DEVELOP...UP TO A THIRD OF AN INCH FROM A
STRONG STORM. MOISTURE WILL INCREASE BEHIND A FRONT TONIGHT AND
BRING A GOOD CHANCE FOR STORMS SATURDAY. THESE STORMS WILL BE
CAPABLE OF PRODUCING HEAVY RAIN...POSSIBLY UP TO AN INCH PER HOUR
OR LESS FROM A STRONG STORM.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KRIEDERMAN
LONG TERM....D-L
AVIATION...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
353 PM EDT FRI AUG 2 2013
.SYNOPSIS...
A COLD FRONT MOVES THROUGH NEW ENGLAND SATURDAY MORNING BRINGING A
CHANCE OF SHOWERS/THUNDERSTORMS. MOSTLY DRY WEATHER EXPECTED
EARLY NEXT WEEK WITH POTENTIAL FOR SOME SPOTTY SHOWERS SUN. A MID
WEEK STORM MAY BRING MORE WIDESPREAD RAIN.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THROUGH 00Z...
PLENTY OF DIURNAL CUMULUS POPPED DURING THE AFTERNOON AND WILL
CONTINUE THROUGH EVENING. SCATTERED SHOWERS/TSTMS ARE POSSIBLE
FROM THESE CLOUDS AS SBCAPE VALUES /PER SPC MESOANALYSIS/ ARE
1000-1500 J/KG. ONE TSTM COMPLEX MOVING ACROSS CENTRAL NY
EXTRAPOLATES TO THE CT VALLEY AROUND 22Z. HRRR AGREES WITH THIS
TIMING. WE BRING CHANCE POPS INTO THE CT VALLEY 22Z-00Z WITH
SLIGHT CHANCE POPS FARTHER EAST.
TONIGHT...
THE REMAINS OF THE NY SHOWERS/TSTMS WILL MOVE ACROSS THE REGION
00Z TO 02Z AND THEN MOVE OFFSHORE. WE ARE EXPECTING A PERIOD OF
CLEARING FOR A FEW HOURS AFTER THAT. WITH LIGHT WINDS AND
DEWPOINTS IN THE 50S INLAND...WE EXPECT TEMPS WILL DROP BELOW 60
MOST PLACES AWAY FROM THE COAST.
COLD FRONT APPROACHING FROM THE WEST WILL SPREAD MORE CLOUDS IN
LATE AT NIGHT WITH SOME POTENTIAL FOR PCPN. WE HAVE SLIGHT CHANCE
POPS DEVELOPING WEST TO EAST AFTER 2 AM.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...COLD FRONT CROSSES NEW ENGLAND THE FIRST PART OF
SATURDAY. THE RIGHT ENTRANCE REGION OF A 110 KNOT UPPER JET IS IN
PLACE TO PROVIDE UPPER VENTING...BUT MOISTURE AND INSTABILITY ARE
LESS FAVORABLE. THE GFS DOES SHOW MID LEVEL LAPSE RATES 6-6.5C/KM
SATURDAY MORNING...BUT THIS MOVES OFFSHORE BY AFTERNOON. TIMING
OF THE FROPA IS ALSO IN A LESS FAVORABLE TIME OF THE DAY. WE WILL
FEATURE CHANCE POPS ALL AREAS DURING THE MORNING AND LINGERING
POPS IN RI AND SOUTHEAST MASS FOR PART OF THE AFTERNOON.
SATURDAY NIGHT...
THIS LOOKS LIKE A QUIET COOL NIGHT. A SHORTWAVE DIGS OVER THE
GREAT LAKES AND MOVES EAST TOWARD NEW ENGLAND. THIS MAY BRING
INCREASING CLOUDS TO US LATE AT NIGHT...BUT ANY SHOWERS LOOK LIKE
THEY SHOULD STAY TO OUR WEST DURING THE NIGHT. FAIR SKIES AND
DEWPOINTS IN THE 50S SHOULD ALLOW MIN TEMPS IN THAT RANGE EXCEPT
LOW 60S ALONG THE COAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* MOSTLY DRY...SEASONABLE TO SEASONABLY COOL WEATHER
* FEW SHOWERS POSSIBLE SUNDAY
* NEXT CHANCE OF WIDESPREAD RAIN THU
MODELS ARE IN DECENT AGREEMENT THROUGH THE EARLY PART OF NEXT WEEK.
EVEN TOWARDS THE END OF NEXT WEEK THERE ARE ONLY A FEW MINOR
DISCREPANCIES AND MORE IN THE TIMING RATHER THAN THE OVERALL
PATTERN. SUNDAY THROUGH TUESDAY...HIGH PRESSURE BUILDS INTO THE
REGION AND THEN MOVES OFFSHORE BRINGING SEASONABLY COOL AND DRY
WEATHER TO SOUTHERN NEW ENGLAND. WEDNESDAY ALSO LOOKS TO BE MAINLY
DRY...THOUGH BOTH THE ECMWF AND THE GFS START TO BRING IN SOME RAIN
LATE WEDNESDAY EVENING. WIDESPREAD RAINFALL IS EXPECTED THURSDAY
AHEAD OF A COLD FRONT EXTENDING FROM LOW PRESSURE IN QUEBEC. THERE
ARE A FEW TIMING DISCREPANCIES HERE BETWEEN THE ECMWF AND GFS WITH
HOW QUICKLY THE COLD FRONT MOVES THROUGH WITH THE GFS A BIT QUICKER
WITH MOVING OUT THE PRECIP THAN THE ECMWF.
SUNDAY...HIGH PRESSURE STARTS BUILDING INTO THE REGION SUNDAY BUT
WITH A SHORTWAVE MOVING ACROSS SOUTHERN NEW ENGLAND...A FEW DIURNAL
SHOWERS ARE POSSIBLE SUNDAY AFTERNOON. HAVE SLIGHT CHANCE TO CHANCE
POPS ACROSS MUCH OF SOUTHERN NEW ENGLAND FOR THIS TIME PERIOD.
OTHERWISE...EXPECT THE BEGINNING OF A COOLING TREND WITH
TEMPERATURES RIGHT AT OR JUST BELOW NORMAL.
MONDAY AND TUESDAY...HIGH PRESSURE MOVES OVER SOUTHERN NEW ENGLAND
MONDAY AND THEN OFFSHORE TUESDAY BRINGING MOSTLY DRY WEATHER AND
BELOW NORMAL TEMPS FOR EARLY AUGUST.
WEDNESDAY THROUGH FRIDAY...A SHORTWAVE MOVES ACROSS SOUTHERN NEW
ENGLAND WEDNESDAY AS LOW PRESSURE STARTS TO MOVE INTO QUEBEC. A
COLD FRONT EXTENDING SOUTHWARD WILL MOVE ACROSS THE AREA THURSDAY
EVENING AND PUSH OFFSHORE OVERNIGHT. COULD SEE RAIN BEGIN WEDNESDAY
EVENING THEN CONTINUE THROUGH MUCH OF THURSDAY AHEAD OF THE FRONT.
THIS LOOKS LIKE IT WILL BE MORE OF A HEAVY RAIN THREAT WITH PWATS
SURGING TO ABOVE 2 INCHES AGAIN BUT THERE IS POTENTIAL FOR
THUNDERSTORMS WITH STEEP MID LEVEL LAPSE RATES AND DECENT
INSTABILITY AHEAD OF THE FRONT. THEN FRIDAY SHOULD BE ANOTHER
RELATIVELY QUIET DAY AS THE FRONT PUSHES OFFSHORE AND DRY...SLIGHTLY
COOLER WEATHER RETURNS.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE IN THE TREND TOWARD VFR...LOWER CONFIDENCE IN
EXACT TIMING OVER THE NEXT FEW HOURS.
TONIGHT...WEST WINDS AROUND 10 KNOTS AND A FEW GUSTS NEAR 20
KNOTS DIMINISHING THIS EVENING. AN AREA OF SHOWERS/TSTMS MOVES
ACROSS SOUTHERN NEW ENGLAND THIS EVENING...ENTERING THE CT VALLEY
AROUND 22Z AND LEAVING THE EAST MASS COAST AROUND 02Z. BEST CHANCE
OF SHOWERS WILL BE ALONG AND NORTH OF THE MASS TURNPIKE. GENERALLY
VFR WITH A BRIEF DIP TO MVFR CIGS/VSBYS POSSIBLE IN ANY
SHOWERS/TSTMS.
SATURDAY...A COLD FRONT MOVES THROUGH DURING THE MORNING WITH
ANOTHER CHANCE OF SHOWERS AND SCATTERED TSTMS WITH BRIEF MVFR
CIGS/VSBYS.
SATURDAY NIGHT...VFR.
KBOS TERMINAL...HIGH CONFIDENCE. BRIEF MVFR CIGS/VSBYS POSSIBLE
AROUND 9 PM AS AN AREA OF SHOWERS/TSTMS...OR THEIR
REMNANTS...WILL MOVE THROUGH. ANOTHER CHANCE OF SHOWERS TOWARD
SUNRISE SATURDAY AS A COLD FRONT MOVES THROUGH.
KBDL TERMINAL...HIGH CONFIDENCE. BRIEF MVFR CIGS/VSBYS POSSIBLE
AROUND 6-7 PM AS AN AREA OF SHOWERS/TSTMS...OR THEIR
REMNANTS...WILL MOVE THROUGH. ANOTHER CHANCE OF SHOWERS TOWARD
SUNRISE SATURDAY AS A COLD FRONT MOVES THROUGH.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...MODERATE TO HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY
OF BRIEF MVFR/IFR CONDITIONS IN ISOLATED TO SCATTERED SHOWERS.
MONDAY THROUGH WEDNESDAY...HIGH CONFIDENCE. VFR. LOW PROBABILITY
OF MVFR/IFR CONDITIONS IN SCT SHRA/FG WEDNESDAY NIGHT.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
WINDS SHOULD REMAIN BELOW 25 KNOTS MOST OF THE TIME...BUT A FEW
GUSTS NEAR 25 KNOTS POSSIBLE AROUND NANTUCKET SOUND SATURDAY
AFTERNOON. SEAS WILL BUILD ON THE SOUTHERN OUTER COASTAL WATERS
TONIGHT AND SATURDAY WITH 5 FOOT VALUES EXPECTED. SEAS THEN
DIMINISH DURING SATURDAY NIGHT.
A SMALL CRAFT ADVISORY CONTINUES FOR THE SOUTHERN OUTER COASTAL
WATERS. IF LATER INFORMATION ON WINDS GOES STRONGER...THE SCA MAY
BE EXPANDED CLOSER TO SHORE.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
HIGH CONFIDENCE. MOSTLY QUIET BOATING WEATHER EXPECTED SUNDAY
THROUGH WEDNESDAY. SEAS START TO INCREASE TO AROUND 5 FEET ON THE
OUTER WATERS ON THURSDAY. MAINLY WESTERLY WINDS WILL REMAIN BELOW
25 KTS FOR THE MOST PART SHIFTING TO THE SOUTHWEST OR NORTHWEST AT
TIMES THROUGH THE PERIOD. WINDS SHIFT TO THE SOUTH WEDNESDAY AND
WEDNESDAY NIGHT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 AM EDT SUNDAY
FOR ANZ254>256.
&&
$$
SYNOPSIS...WTB/RLG
NEAR TERM...WTB
SHORT TERM...WTB
LONG TERM...RLG
AVIATION...WTB/RLG
MARINE...WTB/RLG
AREA FORECAST DISCUSSION
NWS TAUNTON MA
347 PM EDT FRI AUG 2 2013
.SYNOPSIS...
A COLD FRONT MOVES THROUGH NEW ENGLAND SATURDAY MORNING BRINGING A
CHANCE OF SHOWERS/THUNDESTORMS. ANOTHER FRONT MOVES THROUGH ON
SUNDAY. HIGH PRESSURE THEN BRINGS DRY WEATHER FOR THE FIRST HALF
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THROUGH 00Z...
PLENTY OF DIURNAL CUMULUS POPPED DURING THE AFTERNOON AND WILL
CONTINUE THROUGH EVENING. SCATTERD SHOWERS/TSTMS ARE POSSIBLE FROM
THESE CLOUDS AS SBCAPE VALUES /PER SPC MESOANALYSIS/ ARE
1000-1500 J/KG. ONE TSTM COMPLEX MOVING ACROSS CENTRAL NY
EXTRAPOLATES TO THE CT VALLEY AROUND 22Z. HRRR AGREES WITH THIS
TIMING. WE BRING CHANCE POPS INTO THE CT VALLEY 22Z-00Z WITH
SLIGHT CHANCE POPS FARTHER EAST.
TONIGHT...
THE REMAINS OF THE NY SHOWERS/TSTMS WILL MOVE ACROSS THE REGION
00Z TO 02Z AND THEN MOVE OFFSHORE. WE ARE EXPECTING A PERIOD OF
CLEARING FOR A FEW HOURS AFTER THAT. WITH LIGHT WINDS AND
DEWPOINTS IN THE 50S INLAND...WE EXPECT TEMPS WILL DROP BELOW 60
MOST PLACES AWAY FROM THE COAST.
COLD FRONT APPROACHING FROM THE WEST WILL SPREAD MORE CLOUDS IN
LATE AT NIGHT WITH SOME POTENTIAL FOR PCPN. WE HAVE SLIGHT CHANCE
POPS DEVELOPING WEST TO EAST AFTER 2 AM.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...COLD FRONT CROSSES NEW ENGLAND THE FIRST PART OF
SATURDAY. THE RIGHT ENTRANCE REGION OF A 110 KNOT UPPER JET IS IN
PLACE TO PROVIDE UPPER VENTING...BUT MOISTURE AND INSTABILITY ARE
LESS FAVORABLE. THE GFS DOES SHOW MID LEVEL LAPSE RATES 6-6.5C/KM
SATURDAY MORNING...BUT THIS MOVES OFFSHORE BY AFTERNOON. TIMING
OF THE FROPA IS ALSO IN A LESS FAVORABLE TIME OF THE DAY. WE WILL
FEATURE CHANCE POPS ALL AREAS DURING THE MORNING AND LINGERING
POPS IN RI AND SOUTHEAST MASS FOR PART OF THE AFTERNOON.
SATURDAY NIGHT...
THIS LOOKS LIKE A QUIET COOL NIGHT. A SHORTWAVE DIGS OVER THE
GREAT LAKES AND MOVES EAST TOWARD NEW ENGLAND. THIS MAY BRING
INCREASING CLOUDS TO US LATE AT NIGHT...BUT ANY SHOWERS LOOK LIKE
THEY SHOULD STAY TO OUR WEST DURING THE NIGHT. FAIR SKIES AND
DEWPOINTS IN THE 50S SHOULD ALLOW MIN TEMPS IN THAT RANGE EXCEPT
LOW 60S ALONG THE COAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* MOSTLY DRY...SEASONABLE TO SEASONABLY COOL WEATHER
* FEW SHOWERS POSSIBLE SATURDAY...SUNDAY...AND TUESDAY
* NEXT CHANCE OF WIDESPREAD RAIN WED INTO THU
OVERVIEW AND MODEL PREFERENCES...
02/00Z MODEL GUIDANCE SUITE IS IN AT LEAST REASONABLE AGREEMENT
THROUGH THE LONG TERM SUCH THAT THE SYNOPTIC FEATURES ARE IN LINE.
THERE ARE SOME SMALLER SCALE DIFFERENCES WHICH WILL DEFINE THE WX
PARTICULARLY LATER IN THE WORK WEEK...BUT GIVEN THE FACT THAT GFS
AND ECMWF DETERMINISTIC RUNS ARE IN FAIR AGREEMENT...WILL BE USING
A BLEND OF THESE AS A BASELINE FOR THIS FORECAST UPDATE. THE SAT
NIGHT INTO SUN TIMEFRAME WILL BE UNDER THE INFLUENCE OF A STRONG
SHORTWAVE DIVING INTO THE ONTARIO/QUEBEC LONGWAVE TROF...WHICH
WILL THEN CULMINATE IN A CUTOFF MOVING INTO THE
MARITIMES...SEPARATING FROM THE HUDSON BAY CUTOFF. WITH THIS
DIGGING TROF AND SHORTWAVE...AND ITS ATTENDANT SFC COLD
FRONT...THERE WILL THE RENEWED CHANCE FOR SOME SCT PRECIP ON
SUN...PARTICULARLY THROUGH NRN NEW ENGLAND. WITH THIS INITIAL
CUTOFF SEPARATING FROM THE CUTOFF CENTERED ON HUDSON BAY...THIS
WILL ALLOW THE BROAD TROF TO GIVE WAY TO SOME ENHANCED RIDGING
FROM THE SRN CONUS...LENDING TOWARD A DRY HIGH PRES FOR MUCH OF
THE EARLY HALF OF THE WEEK.
A TRANSITION IS ON TAP FOR THE END OF THE WEEK AS VERY STRONG
RIDGING IN NW CANADA FOLDS OVER...FORCING THE HUDSON BAY CUTOFF TO
DIG S ITSELF LEADING TOWARD ANOTHER STRONG TROF FOR THE NORTHEAST.
GIVEN THE HIGHLY AMPLIFIED FLOW PATTERN DRIVING THIS SYSTEM...AND
TYPICAL MODEL BIASES IN THE EXTENDED...TIMING IS SOMEWHAT IN
QUESTION. HOWEVER...IT APPEARS THAT A DRY TO WET/UNSETTLED
TRANSITION IS LIKELY IN THE WED/THU PERIOD.
DETAILS...
SAT NIGHT AND SUN...
STRONG KICKER SHORTWAVE WILL BE SLIDING THROUGH THE LONGWAVE TROF
TO THE N WITH AN ATTENDANT COLD FRONT IN TOW. AM NOTING ENOUGH
LIFT FOR AT LEAST A FAIR AMOUNT OF CLOUD COVER WITH THIS FROPA.
HOWEVER...GENERALLY W-NW FLOW INITIALLY COLUMN MAY BE A BIT TOO
DRY FOR WIDESPREAD SHOWERS. BETTER FORCING N...SO WILL TAPER POPS
FOR SUN WITH CHANCE OVER NRN MA/SRN NH...TO SLIGHT CHANCE NEAR THE
S COAST. NOT OUT OF THE QUESTION MANY LOCATIONS REMAIN DRY WITH
THIS FINAL FRONT UNLESS BETTER DYNAMICS ARE FORECAST IN THE NEXT
48 HOURS. INSTABILITY IS MODEST...BUT APPARENT...SO WILL ALSO
INCLUDE AN ISOLATED THREAT FOR T-STORMS. TEMPS WILL BE NEAR TO
SLIGHTLY BELOW NORMAL THANKS TO COOL AIRMASS AND CLOUD COVER.
SUN NIGHT INTO TUE NIGHT...
MID LVL RIDGING GETS A CHANCE TO BUILD IN AS CUTOFF LOW SHIFTS
INTO THE MARITIMES. DRY HIGH PRES WILL SLIDE THROUGH THE REGION
FROM THE W. EXPECTING A MOSTLY DRY PERIOD. TEMPS WILL START ON THE
COOL SIDE OF NORMAL...MODERATING GRADUALLY THROUGH THE PERIOD.
HUMIDITY WILL ALSO START LOW AND INCREASE SLOWLY.
WED INTO FRI...
STRONGER WAVE OF LOW PRES ALOFT WILL SLIDE INTO SRN CANADA WITH
DEEPENING AND DIGGING TROF OVER THE NORTHEAST CONUS.
THEREFORE...EXPECT A TRANSITION TO WET AND UNSETTLED BEGINNING
WED. AT THIS TIME...THE LOW PRES ASSOCIATED WITH THIS FEATURE IS
PROGGED TO REMAIN IN QUEBEC AND ONTARIO...WITH STRONG WARM AND
COLD FRONT TO MOVE THROUGH NEW ENGLAND. IT DOES APPEAR THAT AT
LEAST SRN NEW ENGLAND WILL BREAK INTO THE WARM SECTOR SOMETIME THU
AHEAD OF THE INITIAL STRONG COLD FRONT...SO WILL BE ADDING A
THREAT FOR THUNDER.
GIVEN THE TROF WILL BE DIGGING/TRANSITIONING THROUGH THE WHOLE
THREE DAY PERIOD THE LOW PRES AND FRONT MAY BE SLOW TO MOVE
THROUGH...SO WILL BE KEEPING POPS AROUND UNTIL FRI. EVEN THOUGH
THERE WILL BE POPS THE ENTIRE THREE DAY PERIOD...SOME BREAKS ARE
POSSIBLE ESPECIALLY IF THE ACTIVITY IS MORE CONVECTIVE AS THE
RECENT MODELS SUGGEST.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE IN THE TREND TOWARD VFR...LOWER CONFIDENCE IN
EXACT TIMING OVER THE NEXT FEW HOURS.
TONIGHT...WEST WINDS AROUND 10 KNOTS AND A FEW GUSTS NEAR 20
KNOTS DIMINISHING THIS EVENING. AN AREA OF SHOWERS/TSTMS MOVES
ACROSS SOUTHERN NEW ENGLAND THIS EVENING...ENTERING THE CT VALLEY
AROUND 22Z AND LEAVING THE EAST MASS COAST AROUND 02Z. BEST CHANCE
OF SHOWERS WILL BE ALONG AND NORTH OF THE MASS TURNPIKE. GENERALLY
VFR WITH A BRIEF DIP TO MVFR CIGS/VSBYS POSSIBLE IN ANY
SHOWERS/TSTMS.
SATURDAY...A COLD FRONT MOVES THROUGH DURING THE MORNING WITH
ANOTHER CHANCE OF SHOWERS AND SCATTERED TSTMS WITH BRIEF MVFR
CIGS/VSBYS.
SATURDAY NIGHT...VFR.
KBOS TERMINAL...HIGH CONFIDENCE. BRIEF MVFR CIGS/VSBYS POSSIBLE
AROUND 9 PM AS AN AREA OF SHOWERS/TSTMS...OR THEIR
REMNANTS...WILL MOVE THROUGH. ANOTHER CHANCE OF SHOWERS TOWARD
SUNRISE SATURDAY AS A COLD FRONT MOVES THROUGH.
KBDL TERMINAL...HIGH CONFIDENCE. BRIEF MVFR CIGS/VSBYS POSSIBLE
AROUND 6-7 PM AS AN AREA OF SHOWERS/TSTMS...OR THEIR
REMNANTS...WILL MOVE THROUGH. ANOTHER CHANCE OF SHOWERS TOWARD
SUNRISE SATURDAY AS A COLD FRONT MOVES THROUGH.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF BRIEF
MVFR CONDITIONS IN ISOLATED TO SCATTERED SHOWERS.
MONDAY...HIGH CONFIDENCE.
VFR.
TUESDAY...HIGH CONFIDENCE.
MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
WINDS SHOULD REMAIN BELOW 25 KNOTS MOST OF THE TIME...BUT A FEW
GUSTS NEAR 25 KNOTS POSSIBLE AROUND NANTUCKET SOUND SATURDAY
AFTERNOON. SEAS WILL BUILD ON THE SOUTHERN OUTER COASTAL WATERS
TONIGHT AND SATURDAY WITH 5 FOOT VALUES EXPECTED. SEAS THEN
DIMINISH DURING SATURDAY NIGHT.
A SMALL CRAFT ADVISORY CONTINUES FOR THE SOUTHERN OUTER COASTAL
WATERS. IF LATER INFORMATION ON WINDS GOES STRONGER...THE SCA MAY
BE EXPANDED CLOSER TO SHORE.
OUTLOOK...SUNDAY THROUGH TUESDAY...
HIGH CONFIDENCE.
GENERALLY QUIET BOATING WEATHER THROUGH THE PERIOD. THE ONLY
CAVEATS WILL BE FOR SOME 5 FT SEAS POSSIBLE SAT NIGHT ON THE
SOUTHEAST OCEAN WATERS...AND THE CHANCE FOR 20-25 KT NW WINDS
NEAR THE SHORELINES ON MON.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 PM THIS EVENING
TO 2 AM EDT SUNDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...WTB/DOODY
NEAR TERM...WTB
SHORT TERM...WTB
LONG TERM...DOODY
AVIATION...WTB/DOODY
MARINE...WTB/DOODY
AREA FORECAST DISCUSSION
NWS NEW YORK NY
344 PM EDT FRI AUG 2 2013
.SYNOPSIS...
A SERIES OF WEAK UPPER AIR DISTURBANCES WILL PASS MAINLY NORTH OF
THE AREA THROUGH SATURDAY WITH WEAK SURFACE LOW PRESSURE PASSING
TO OUR SOUTH SATURDAY NIGHT. A COLD FRONTAL PASSAGE ON SUNDAY
WILL USHER IN SUNNY AND COOLER WEATHER FOR THE BEGINNING OF NEXT
WEEK. A WARMING TREND...ALONG WITH AN INCREASE IN HUMIDITY...WILL
FOLLOW FOR THE MIDDLE OF THE WEEK. THERE WILL BE A CHANCE FOR RAIN
LATE WEDNESDAY THROUGH THURSDAY AS THE PATTERN ATTEMPTS TO
TRANSITION AGAIN.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
3 PM UPDATE...CONVECTION OVER CENTRAL NY STATE FORM KBGM TO KSYR. LATEST
HRRR HAS A REASONABLE HANDLE ON THIS. AS THE SHORTWAVE PRESSES
EAST INTO NEW ENGLAND SOME ADDITIONAL DEVELOP SEEMS POSSIBLE TO THE
SOUTH WHICH SATELLITE SUPPORTS CURRENTLY HAPPENING OVER WESTERN
PA. THUS KEEPING POPS OUT OF THE FCST UNTIL THIS 22Z FOR NW
SECTIONS. WILL FOLLOW THE HRRR AS IT HAS CONTINUITY WITH THE 09Z
SREF PROBABILITIES FOR THIS EVENING. CARRYING A 20-30 POP WITH
HIGHEST POP ALONG NORTHERN SECTION. WILL STILL NOT CONVERT TO
COVERAGE YET AS NOT CONFIDENT THAT CONVECTION WILL ACTUALLY REACH
OUR FCST AREA. CONTINUED TO INCLUDE TSTMS BASED ON WEAK
INSTABILITY OF A FEW HUNDRED JOULES SEEN IN RUC FCST SOUNDINGS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
3 PM UPDATE...GOING MORE OPTIMISTIC BASED ON 09Z SREF AND 12Z
DETERMINISTIC MODELS. HAVE LOWERED POPS TO NIL OR SLIGHT CHANCE
FOR THE NY METRO. WITH LOWER POPS COMES WARMER TEMPS. NAM MOS IS
3-4 F WARMER THAN GFS MOS. WITH RECENT LOCAL BIAS OF MOS AND HUMAN
TO BE TOO WARM...HAVE CHOSEN TO STAY CLOSE TO BIAS CORRECT GFS MOS
- WHICH IS CLOSE TO OPERATIONAL GFS MOS.
WEAK LOW PRESSURE FORMING ALONG THE FRONTAL BOUNDARY TO OUR SOUTH
SUGGEST THE CHANCE OF LIGHT RA FOR NJ TO LONG ISLAND. SREF AND
12Z DETERMINISTIC RUNS ARE CONSISTENT WITH THIS. AND HAVE BEEN
FROM PREVIOUS RUNS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
H5 TROF AXIS PASSES AROUND 18Z SUN. THERE WILL BE THE CHC FOR AN
ISOLD SHRA OR TSTM...MAINLY ACROSS THE INTERIOR WITH LESS CIN. NAM12
PROGS SBCAPE GENERALLY AOB 800 J/KG. OTHERWISE...FAIR WX CU SHOULD
DEVELOP WITH STEEPENING MID LVL LAPSE RATES.
KEY TO TEMPS SUN NGT WILL BE WHETHER WINDS FULLY DECOUPLE. GUIDANCE
STILL SUGGESTS LOWS AROUND 50 ACROSS THE INTERIOR VALLEYS AND PINE
BARRENS.
SUNNY AND DRY ON MON. TEMPS BLW CLIMO.
DESPITE SOME WEAK MID LVL MOISTURE ADVECTION MON NGT...POTENTIAL FOR
TEMPS TO BE COOLER THAN SUN NGT WITH THE HIPRES CENTERED OVER THE
MID-ATLANTIC. TRENDED THE FCST COOLER.
HEIGHTS GRADUALLY INCREASE TUE AND WED...SO EXPECT WARMING TEMPS
THRU THE PERIOD. CHCS FOR RAIN APPEAR TO HOLD OFF TIL THE DAYTIME ON
WED...WHERE ENOUGH INSTABILITY MAY DEVELOP ACROSS THE WRN ZONES TO
ALLOW FOR CONVECTIVE INITIATION. POCKETS OF SHRA/TSTMS WILL BE
POSSIBLE THRU WED NGT WITH FOCUSED WAA ALOFT.
CWA MAY BE WEDGED BETWEEN THE SRN CONUS RIDGE AND CANADIAN H5 LOW
FOR THU AND BEYOND. THIS WILL MEAN THE CONVECTIVE ZONE COULD BE NEAR
OR OVER TO THE CWA. IT IS ALSO POSSIBLE THAT IF THIS ZONE OF
CONVECTION REMAINS JUST TO THE N...THE METRO WILL BE IN FOR A FEW
DAYS OF HOT AND HUMID WX. FOR NOW...THE OFFICIAL FCST IS CLOSER TO
THE RAINIER SOLN...AS THIS HAS BEEN THE MORE CONSISTENT PROG OVER
THE LAST FEW DAYS.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
WEAKENING HIGH PRESSURE GIVES WAY TO AN APPROACHING COLD FRONT BY
LATER ON SATURDAY. WITH EXCEPTION OF A POSSIBLE SHOWER OR
THUNDERSTORM...MAINLY THIS EVENING...PRIMARILY VFR CONDITIONS ARE
EXPECTED. THERE IS ANOTHER CHANCE OF SHOWERS AS WELL ON
SATURDAY...MAINLY TO THE WEST. SINCE CONFIDENCE IS LOW ON TIMING
AND LOCATION...SHOWERS OR THUNDERSTORMS HAVE BEEN LEFT OUT OF THE
TAFS AT THE MOMENT. ONLY EXCEPTION WOULD BE KSWF WITH VCSH...WHERE
SOME SHOWERS COULD PASS NEAR INTO EARLY THIS EVENING.
WINDS ARE OUT OF THE W-SW 10-15 KT GUSTING TO AROUND 20 KT. WINDS
LOWER TONIGHT AND PICK UP AGAIN ON SATURDAY AT AROUND THE SAME
DIRECTION AND SPEEDS AS THAT OF THE PREVIOUS DAY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY.
END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KJFK FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY.
END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KLGA FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY.
END TIME OF GUSTS COULD BE 1-2 HRS OFF. WIND DIRECTION AT TIMES
COULD BE 20-30 DEGREES OFF INTO EARLY THIS EVENING.
KTEB FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY.
END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KHPN FCSTER COMMENTS: OCCASIONAL GUSTS 15-20 KT POSSIBLE BEFORE
00Z.
KISP FCSTER COMMENTS: TIMING OF MORE SW WIND MAY BE OFF BY 1 HOUR.
GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY. END TIME OF GUSTS
COULD BE 1-2 HRS OFF.
.OUTLOOK FOR 18Z SAT THROUGH WED...
.REST OF SAT AFTN...MAINLY VFR. MVFR IS POSSIBLE IN SHOWERS.
.SAT NIGHT...CHANCE OF LIGHT RAIN MAINLY TOWARDS LONG ISLAND AND NYC
TERMINALS. MVFR POSSIBLE IN LIGHT RAIN.
.SUN-TUE...MAINLY VFR.
.WED...POSSIBLE SHOWERS AND THUNDERSTORMS WITH MVFR OR LOWER
POSSIBLE.
&&
.MARINE...
SEAS STILL EXPECTED TO REACH THE 5 FT CRITERIA ON THE EASTERN
OCEAN WATERS. THIS CONTINUES THROUGH SAT AND THERE`S POTENTIAL
FOR 25 KT GUSTS AS WELL LATE SATURDAY AFTERNOON. THUS THE SCA FOR
THE EASTERN WATERS IS EXTENDED INTO SATURDAY NIGHT.
OTHERWISE...WINDS REMAIN UP FOR EVENING LOCAL FISHING IN THE
MODERATE TO FRESH BREEZE RANGE THIS EVENING WITH MORE OF A FRESH
BREEZE LATE SATURDAY.
WINDS WILL BE BRISK ON SUN BUT EXPECTED TO REMAIN BLW SCA LVLS ATTM.
SPEEDS MAY INCREASE SUN NGT TO SCA LVLS BEHIND THE FRONT. THE NW
WINDS WILL DECREASE DURING THE DAY ON MON...WITH WINDS AND WAVES BLW
SCA LVLS TUE. 5 FT SEAS MAY DEVELOP ON THE OCEAN BY WED EVE WITH
INCREASING SLY FLOW.
&&
.HYDROLOGY...
THE NEXT CHANCE FOR ORGANIZED WIDESPREAD RAINFALL WILL BE LATE
NEXT WEEK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 PM THIS
EVENING TO MIDNIGHT EDT SATURDAY NIGHT FOR ANZ350.
&&
$$
SYNOPSIS...JMC/TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE
LONG TERM...JMC
AVIATION...JM
MARINE...JMC/TONGUE
HYDROLOGY...TONGUE
AREA FORECAST DISCUSSION
NWS NEW YORK NY
157 PM EDT FRI AUG 2 2013
.SYNOPSIS...
A SERIES OF WEAK UPPER AIR DISTURBANCES WILL PASS MAINLY NORTH OF
THE AREA THROUGH SATURDAY. CANADIAN HIGH PRESSURE FROM THE GREAT
LAKES ON SUNDAY BUILDS INTO THE REGION THROUGH TUESDAY. THE HIGH
MOVES OFFSHORE TUESDAY NIGHT AS A FRONTAL SYSTEM APPROACHES FROM
THE WEST. THE FRONTAL SYSTEM WILL AFFECT THE AREA WEDNESDAY AND
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1 PM UPDATE...CONVECTION HAS INITIATED OVER CENTRAL NY STATE WITH
MAIN AREA NOW APPROACHING KSYR. LATEST HRRR HAS GOOD HANDLE ON
THIS. THUS KEEPING POPS OUT OF THE FCST UNTIL AFTER 20Z FOR FAR NW
SECTION. WILL FOLLOW THE HRRR AS IT HAS CONTINUITY WITH THE 09Z
SREF PROBABILITIES FOR THIS EVENING. CARRYING A 20-30 POP WITH
HIGHEST POP ALONG NORTHERN SECTION. WILL NOT CONVERT TO COVERAGE
YET AS NOT CONFIDENT THAT CONVECTION WILL ACTUALLY REACH OUR FCST
AREA. CONTINUED TO INCLUDE TSTMS BASED ON WEAK INSTABILITY OF A
FEW HUNDRED JOULES SEEN IN RUC FCST SOUNDINGS.
&&
.SHORT TERM /SATURDAY/...
1 PM UPDATE...GOING MORE OPTIMISTIC BASED ON 09Z SREF AND 12Z
DETERMINISTIC MODELS. HAVE LOWERED POPS TO NIL OR SLIGHT CHANCE
FOR THE NY METRO. WITH LOWER POPS COMES WARMER TEMPS. NAM MOS IS
3-4 F WARMER THAN GFS MOS. WITH RECENT LOCAL BIAS OF MOS AND
HUMAN TO BE TOO WARM...HAVE CHOSEN TO STAY CLOSE TO BIAS CORRECT
GFS MOS - WHICH IS CLOSE TO OPERATIONAL GFS MOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A WEAK COLD FRONT WILL MOVE SOUTH OF THE REGION SATURDAY NIGHT AS
A SHORTWAVE ROTATES THROUGH THE UPPER TROUGH ACROSS EASTERN CANADA
AND INTO THE NORTHEASTERN UNITED STATES. AN IMPULSE WILL ALSO BE
MOVING AROUND THE BASE OF THE TROUGH FROM THE MIDWEST SATURDAY
NIGHT. SO WILL HAVE CHANCE TO SLIGHT CHANCE POPS SATURDAY NIGHT.
THE UPPER TROUGH REMAINS INTO THE BEGINNING OF NEXT WEEK...AS FLOW
BECOME NEARLY ZONAL. WITH THE NEARLY STATIONARY UPPER TROUGH AND
THE NEXT SHORTWAVE SLOWER TO ROTATE INTO THE REGION AS THE UPPER
LOW CLOSES OFF HAVE DELAYED THE ONSET OF THE NEXT CHANCE OF
PRECIPITATION UNTIL LATE TUESDAY NIGHT...WITH CHANCE POPS DELAYED
UNTIL WEDNESDAY. THE NEW ECMWF 00Z/02 INDICATING THAT
PRECIPITATION MAY HOLD OFF UNTIL LATER WEDNESDAY. WITH A BLOCKING
PATTERN SETTING UP...THEN UPPER TROUGH WILL REMAIN THROUGH THE
UPCOMING WEEK AND THE ASSOCIATED SURFACE FRONTAL SYSTEM WILL BE
SLOW TO MOVE THROUGH. SO WILL HAVE CHANCES OF PRECIPITATION FOR
WEDNESDAY AND THURSDAY...AND CONTINUING INTO FRIDAY.
WITH A WEST TO NORTHWEST FLOW INTO TUESDAY AND THEN CLOUDS AND
PRECIPITATION WEDNESDAY AND THURSDAY WILL BE A RATHER COOL PERIOD.
SUNDAY AND MONDAY TEMPERATURES WERE A BLEND OF THE ECMWF AND MEX
GUIDANCE...AND THEN LEANED TOWARD THE WPC GUIDANCE...SUNDAY NIGHT
THROUGH THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
WEAKENING HIGH PRESSURE GIVES WAY TO AN APPROACHING COLD FRONT BY
LATER ON SATURDAY. WITH EXCEPTION OF A POSSIBLE SHOWER OR
THUNDERSTORM...MAINLY THIS EVENING...PRIMARILY VFR CONDITIONS ARE
EXPECTED. THERE IS ANOTHER CHANCE OF SHOWERS AS WELL ON SATURDAY.
SINCE CONFIDENCE IS LOW ON TIMING AND LOCATION...SHOWERS OR
THUNDERSTORMS HAVE BEEN LEFT OUT OF THE TAFS AT THE MOMENT.
WINDS ARE OUT OF THE W-SW TODAY 10-15 KT GUSTING TO AROUND 20 KT.
WINDS LOWER TONIGHT AND PICK UP AGAIN ON SATURDAY AT AROUND THE SAME
DIRECTION AND SPEEDS AS THAT OF THE PREVIOUS DAY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS
AFTERNOON. END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KJFK FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS
AFTERNOON. END TIME OF GUSTS COULD BE 1-2 HRS OFF. WIND DIRECTION AT
TIMES COULD BE 20-30 DEGREES TO THE LEFT OF FORECAST LATE THIS
AFTERNOON.
KLGA FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS
AFTERNOON. END TIME OF GUSTS COULD BE 1-2 HRS OFF. WIND DIRECTION AT
TIMES COULD BE 20-30 DEGREES TO THE LEFT OF FORECAST LATE THIS
AFTERNOON.
KTEB FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS
AFTERNOON. END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KHPN FCSTER COMMENTS: OCCASIONAL GUSTS 15-20 KT POSSIBLE THIS
AFTERNOON.
KISP FCSTER COMMENTS: TIMING OF MORE SW WIND MAY BE OFF BY 1 HOUR.
GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS AFTERNOON. END TIME
OF GUSTS COULD BE 1-2 HRS OFF.
.OUTLOOK FOR 18Z SAT THROUGH WED...
.REST OF SAT AFTN...MAINLY VFR. MVFR IS POSSIBLE IN SHOWERS.
.SAT NIGHT...CHANCE OF LIGHT RAIN MAINLY TOWARDS LONG ISLAND AND NYC
TERMINALS. MVFR POSSIBLE IN LIGHT RAIN.
.SUN-TUE...MAINLY VFR.
.WED...POSSIBLE SHOWERS AND THUNDERSTORMS WITH MVFR OR LOWER
POSSIBLE.
&&
.MARINE...
WITH A WEAK SURFACE TROUGH DEVELOPING THIS AFTERNOON THE WIND
SHIFTS BACK TO SOUTHWEST AND SEAS OF 3 TO 4 FT ON THE OCEAN
WATERS.
A FEW GUSTS TO 20 KT ARE POSSIBLE THIS AFTERNOON...OTHERWISE...TRANQUIL
CONDS ON TAP FOR THE DAY. THIS EVENING...SEAS WILL BUILD TO 5 FT
ON THE EASTERN OCEAN WATERS...SO WILL ISSUE A SCA FOR HAZARDOUS
SEAS FOR TONIGHT. CONDS ON THE EASTERN OCEAN WATERS WILL SUBSIDE
BELOW SCA BY SATURDAY MORNING. SUB-ADVISORY CONDS ON TAP FOR
SATURDAY.
ISOLATED TSTMS ARE POSSIBLE THIS EVENING AS A WEAK SHORTWAVE
SLIDES THROUGH THE REGION. ANOTHER SHORTWAVE WILL BRING SCATTERED
SHOWERS WITH ISOLATED THUNDERSTORMS SATURDAY AFTERNOON.
A WEAK COLD FRONT WILL MOVE SOUTH ACROSS THE FORECAST WATERS
SATURDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE WEST SUNDAY
THROUGH TUESDAY AND MOVES EAST OF THE FORECAST WATERS TUESDAY
NIGHT AS A FRONTAL SYSTEM APPROACHES FROM THE WEST. SEAS AND WIND
ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS SATURDAY
NIGHT THROUGH TUESDAY NIGHT.
&&
.HYDROLOGY...
THE NEXT CHANCE FOR ORGANIZED WIDESPREAD RAINFALL WILL BE
WEDNESDAY AND THURSDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 PM THIS
EVENING TO 6 AM EDT SATURDAY FOR ANZ350.
&&
$$
SYNOPSIS...MET/TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE
LONG TERM...MET
AVIATION...JM
MARINE...MET/TONGUE
HYDROLOGY...TONGUE
Area Forecast Discussion
National Weather Service Lincoln IL
540 PM CDT Fri Aug 2 2013
.DISCUSSION...
Issued 248 PM CDT Fri Aug 2 2013
Early afternoon surface map showing the cold front had crossed
much of Wisconsin, then extended westward across southern Iowa to
along the Kansas/Nebraska border. Precipitation so far has been
pretty sparse across the area, with just some high-based very
light showers tracking just south of the I-72 corridor.
Subsidence in the wake of morning convection in northern Illinois
actually allowed for a good deal of clearing across southeast Iowa
and northern Illinois, although diurnal cumulus has been filling
in rather quickly the last couple hours. The clearing helped to
get the air more unstable, with CAPE`s of around 2000 J/kg across
the northern third of the state with little cap, as evidenced by
scattered storms forming around 2 pm just ahead of the front from
Moline to Chicago.
The primary forecast concern in the short term is with the
convective chances over the next 18-24 hours. Rain chances in the
longer range are also a concern due to MCS potential through the
first half of next week.
SHORT TERM...Tonight through Sunday...
Morning model runs have significantly struggled with the
convective trends thus far, so confidence in this part of the
forecast is lower than normal. The most recent HRRR model appears
to be closest to reality, and shows that the broken line of
showers and storms to our north will be drifting across areas
along and north of I-74 into the evening. Scattered storms
currently in Missouri should track eastward as well, affecting
the remainder of the forecast area. Precipitable water values of
1.75 to 2 inches should help produce some heavy rain with the
stronger storms. Can`t rule out some gusty winds and hail as well,
but wind shear overall is rather weak in our area and anything
that does approach severe levels should be the pulse type.
Overnight, the NAM and GFS already have the precipitation on the
wane with a faster push to the cold front, while the ECMWF and
Canadian models linger the showers/storms most of the night with a
slower frontal passage. Have gone with the highest PoPs in the
evening, but kept healthy chances over most of the area overnight.
Not too many changes needed for Saturday, as the frontal boundary
should be through most of the area by midday. Have kept the
northwest CWA dry all day, and continued with all areas north of
I-72 dry by afternoon. All precipitation should be out of the area
by early evening, as high pressure builds southeast into the
Midwest, and cooler/less humid air can be expected the rest of the
weekend.
LONG TERM...Monday through Friday...
Upper level pattern looking fairly agreeable among the GFS and
ECMWF models, with initial northwest flow flattening as a strong
cutoff low sinks southward across Manitoba. GFS remains stronger
with the high keeping our area dry into Monday, while the ECMWF
keeps us on the periphery of the MCS track across Missouri. Have
limited any PoPs to the far southwest for Sunday night and even
then just kept them at 20 percent. Next shortwave on Tuesday
should help boot the high eastward, but convection along the Gulf
Coast will help rob some of the return moisture advection for a
time, so have held off on any decent rain chances until Tuesday
night. Getting into midweek, a surface boundary will become quasi-
stationary as it becomes parallel to the upper flow. The model
differences widen at this point, with the GFS pushing the boundary
through us by late Wednesday night and the ECMWF keeping it north
of the area until Thursday evening. The ultimate position and
associated convective chances will come down to timing of fast
moving shortwaves between the upper low and a sprawling upper high
over the southern U.S. For now have favored a bit of a more
southern push with a period of drier conditions Wednesday night
and Thursday with increasing PoPs again after that.
Geelhart
&&
.AVIATION...
ISSUED 540 PM CDT Fri Aug 2 2013
Cold front was currently located just south of ORD and about to
push thru MLI early this evening. Widely scattered showers and
thunderstorms were occurring ahead of the boundary and are
expected to continue with the front to the east and south across
our area this evening. Coverage still appears too limited to go
much more than VCTS this evening based on current and expected
trends with the precip ahead of the front. The next question becomes
after the frontal passage late tonight, how much, if any MVFR cigs
will occur just behind the front. Passed few runs have been playing
it down with respect to any widespread mvfr cigs/vsbys, but will
have to watch for some patchy ground fog to form late tonight as
winds will be light and variable before mixing out to a northeast
direction at 10 kts by mid or late Saturday morning.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
253 PM CDT FRI AUG 2 2013
.DISCUSSION...
248 PM CDT
THIS AFTERNOON AND TONIGHT...
A SURFACE TROUGH IS DRAPED FROM NORTHERN LAKE MICHIGAN SOUTHWEST
ACROSS SOUTHERN WISCONSIN AND INTO NORTHWESTERN ILLINOIS. AGITATED
CU FIELD HAS DEVELOPED OUT AHEAD OF THE TROUGH FROM DOWNTOWN CHICAGO
WEST ACROSS FAR NORTHERN LA SALLE COUNTY AND SOUTHERN LEE COUNTY.
HAVE RECENTLY SEEN THE FIRST RETURNS ON RADAR DEVELOPING IN THIS
AREA WHICH LATEST SPC MESOANALYSIS SHOWS AS AN AXIS OF 1500 J/KG
UNCAPPED MLCAPE. DEEP LAYER SHEAR IS MARGINAL AT THE MOMENT WITH
ABOUT 30 KTS...BUT THIS NUMBER MAY INCREASE AS WE HEAD INTO THE LATE
AFTERNOON AND EARLY EVENING AS MID LEVEL DISTURBANCE CURRENTLY OVER
NORTH CENTRAL IOWA APPROACHES. THIS FEATURE WILL ALSO INCREASE THE
BROAD SCALE ASCENT OVER THE AREA AND SHOULD LEAD TO AN INCREASE IN
THUNDERSTORM COVERAGE AS WELL AS ORGANIZATION. THERE IS CERTAINLY AN
INCREASED CONCERN FOR SEVERE WEATHER WHICH WILL HAVE TO BE MONITORED
OVER THE NEXT SEVERAL HOURS...ESPECIALLY AS WE GET A LITTLE BETTER
MID LEVEL LAPSE RATES OVER THE AREA AND THE AFOREMENTIONED SHEAR.
THE FOCUS SHOULD SHIFT SOUTH THROUGH THE EVENING. THERE WILL
SOME TRAINING ALONG THE BOUNDARY AS IT SAGS SOUTH THIS EVENING
LEADING TO LOCALIZED HEAVY RAIN AMOUNTS...THOUGH LATEST GUIDANCE
HAS SHIFTED THE FOCUS OF THE LOW LEVEL JET FARTHER EAST OF US
OVERNIGHT...SO APPEARS FOR NOW THAT THE THREAT FOR HEAVY RAIN
OVERNIGHT WILL ALSO BE FARTHER EAST.
SATURDAY THROUGH MONDAY...
SURFACE HIGH WILL BUILD SOUTHEAST FROM THE CANADIAN PRAIRIES...OVER
LAKE MICHIGAN SUNDAY...THEN EAST TO THE MID APPALACHIAN RANGE MONDAY
AND SHOULD PROVIDE A RELATIVELY BENIGN PERIOD OF WEATHER. WE DO GET
A GLANCING BLOW OF COOLER H85 AIR WHICH BOTTOMS OUT 8-9C ON
SUNDAY OVER NORTHEAST PORTIONS OF THE CWA. CANNOT COMPLETELY RULE
OUT SOME DIURNALLY DRIVEN AFTERNOON SHOWERS...AND MODELS DO HINT
AT SEVERAL WEAK SHORTWAVE TROUGHS RIDING DOWN THE RIDGE....BUT
SEEMS MORE LIKELY THAT SUBSIDENCE ASSOCIATED WITH MODERATE MID
LEVEL HEIGHT RISES FROM THE H5 RIDGE BUILDING ACROSS THE AREA WILL
LIMIT CU GROWTH. NAM AND GFS SOUNDINGS BOTH INDICATE A SUBSIDENCE
INVERSION SETTING UP AROUND 750 MB THROUGH THE WEEKEND WHICH WILL
LIMIT THE DEPTH OF THE VERTICAL GROWTH AND SHOULD KEEP THE AREA
DRY.
THIS PERIOD WILL SEE TEMPERATURES WELL BELOW SEASONAL NORMS. AS
MENTIONED...H85 TEMPS BOTTOM OUT SUNDAY AND UPPER AIR CLIMATOLOGY
SHOWS THAT 75% OF THE TIME SURFACE TEMPS TOP OUT AT 76 OR COOLER
WITH H85 TEMPS LESS THAN AROUND 9C. THE ECMWF/GEM/GFS ALL SUPPORT
TEMPS IN THE 71-73 FOR CHICAGO AND 73-74 FOR ROCKFORD...THOUGH THE
NAM WITH ITS TYPICAL HIGH BIAS IS SEVERAL DEGREES WARMER. GIVEN THAT
EVEN MOS GUIDANCE IS CALLING FOR MID 70S...AND WE SHOULD CLOUD UP
SOME WITH COLD AIR CU GROWTH...FELT COMFORTABLE DROPPING TEMPS A
COUPLE MORE DEGREES SUNDAY...CLOSER TO THE BLEND OF RAW GUIDANCE.
TUESDAY AND WEDNESDAY...
WITH THE HIGH SHIFTING EAST OF THE AREA...AND LOW PRESSURE DEEPENING
ACROSS THE CENTRAL/NORTHERN PLAINS...RETURN FLOW INTO THE MID
MISSOURI AND MID MISSISSIPPI VALLEYS SHOULD ALLOW UPPER 60 TO LOW 70
DEWPOINTS TO OVERSPREAD THE AREA WITH MODERATE TO STRONG INSTABILITY
DEVELOPING. STRONG WESTERLIES ALOFT COULD SET THE STAGE FOR A SEVERE
WEATHER OUTBREAK SOMEWHERE NEARBY WITH CURRENT MODEL SOLUTIONS
SETTING THE STAGE JUST TO OUR WEST. WHILE IT`S DIFFICULT TO PIN DOWN
A SEVERE WEATHER THREAT THIS FAR OUT...MODELS ARE IN DECENT
AGREEMENT AND WILL HAVE TO WATCH TUESDAY AND WEDNESDAY CLOSELY.
TEMPERATURES SHOULD RETURN TO SEASONABLE...AND IF ANYTHING CURRENT
PROJECTIONS OF LOW 80S MAY BE A BIT TOO COOL. A COLD FRONT IS
PROJECTED TO PUSH OVER THE AREA WEDNESDAY NIGHT.
THURSDAY AND FRIDAY...
MODELS DIVERGE QUITE A BIT ON HOW FAR SOUTH TO PUSH THE FRONTAL
BOUNDARY. THE GFS PUSHES THE FRONT WAY SOUTH INTO THE SOUTHEASTERN
STATES BY FRIDAY WHILE THE ECMWF STALLS THE FRONT OUT INTO SOUTHERN
ILLINOIS WITH PRECIPITATION OVERRUNNING THE BOUNDARY INTO THE
SOUTHERN CWA. WHILE THE NORTH HALF OF THE CWA SHOULD BE DRY EITHER
WAY...SOUTH OF I-80 ITS LESS CERTAIN. GIVEN THAT THE GFS ENSEMBLE
MAINTAINS SOME QPF FARTHER NORTH THAN THE OPERATIONAL RUN...WILL
MAINTAIN SOME CHANCE FOR THUNDERSTORMS ACROSS THE SOUTHERN CWA LATE
IN THE WEEK.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING AND LOCATION OF NEW CONVECTION EXPECTED TO DEVELOP
EARLY- MID AFTERNOON.
* COLD FRONT PASSAGE THIS EVENING AND TONIGHT GRADUALLY VEERING
WINDS FROM WSW-WNW TO N-NNE BY DAYBREAK.
//DISCUSSION...UPDATED 18Z...
LATE NIGHT-EARLY MORNING CONVECTION HAD MOVED QUICKLY ESE AND
WEAKENED BY MID MORNING AS A SHORT WAVE MOVES INTO THE CENTRAL
GREAT LAKES.
LOSS OF SIGNIFICANT CLOUD COVER WITH DEPARTURE OF CONVECTION HAS
ALLOWED GOOD SURFACE HEATING. HEATING COMBINED WITH LOW LEVEL
MOISTURE ADVECTION INTO THE AREA /SURFACE DEW POINTS HAVE RISEN
FROM UPPER 50S TO UPPER 60S DURING THE MORNING/ IS LEADING TO
INCREASINGLY UNSTABLE CONDITIONS ACROSS THE AREA. A WEAK COLD
FRONT HAS BEEN GRADUALLY DROPPING SOUTHWARD ACROSS N CENTRAL IL
AND EXTREME SE WI DURING THE MORNING THOUGH WITH W WINDS AHEAD OF
IT AND FAIRLY LIGHT NW WINDS BEHIND THE CONVERGENCE AHEAD/ALONG
THE BOUNDARY IS MINIMAL.
WATER VAPOR SATELLITE LOOP SHOWING A SHORT WAVE/MCV OVER SD
MOVING THROUGH THE UPPER RIDGE OVER THE PLAINS. THIS FEATURE WILL
START TO TURN ESE AS IT MOVES PAST THE RIDGE AXIS TAKING IT
ACROSS IA THIS AFTERNOON AND THEN NW AND E CENTRAL IL THIS
EVENING.
HIGH RESOLUTION MODELS CONTINUE TO INDICATE MDW AND ORD BEING ON
THE NORTHERN EDGE OF WHERE THETA-E CONVERGENCE IS MAXIMIZED THIS
AFTERNOON AHEAD OF THE DISTURBANCE THOUGH WITH THE WEAK COLD
FRONT MOVING FURTHER SOUTHWARD INTO NE IL AND INTO AREA OF MAX
CAPE THIS AFTERNOON. RECENT VISIBLE SATELLITE SHOTS SHOWING
MODERATE CU DEVELOPING OVER NORTHERN IL INCLUDING AROUND THE ORD
AND MDW AREAS.
WITH CONTINUED DESTABILIZATION AND WEAK CONVERGENCE ALONG THE
COLD FRONT ANTICIPATE TS TO DEVELOP OVER THE CHI AREA BY MID
AFTERNOON... WITH THE MAIN AREA OF CONVECTION THEN SHIFTING A BIT
SOUTHWARD AS DEEP UPWARD ASSENT STARTS TO SPREAD ESE TO NW AND W
CENTRAL IL LATER IN THE AFTERNOON.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE TSRA DEVELOPING EARLY-MID AFTERNOON.
* MEDIUM CONFIDENCE IN LOCATION OF MAIN TS AREA THIS AFTERNOON.
* HIGH CONFIDENCE IN WINDS GRADUALLY VEERING THIS AFTERNOON
THROUGH OVERNIGHT.
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-00Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT-MONDAY...VFR LIKELY.
SATURDAY NIGHT-WEDNESDAY...LOW CHC OF TSRA.
THURSDAY...VFR LIKELY.
MTF
&&
.MARINE...
232 PM CDT
THUNDERSTORMS WILL PRIMARILY REMAIN OVER THE FAR SOUTHERN END OF THE
LAKE THIS AFTERNOON AND THE STRONGER STORMS MAY PRODUCE GALE FORCE
GUSTS. SOUTHWEST WINDS WILL BECOME NORTH TONIGHT BEHIND A COOL
FRONT...AND NORTH/NORTHWEST WINDS ARE EXPECTED ACROSS THE LAKE
THROUGH SUNDAY. HIGH PRESSURE MOVES OVER THE LAKE SATURDAY...AND
WINDS BECOME SOUTHEAST BY MONDAY MORNING. THE HIGH SHIFTS EAST OF
THE LAKE MONDAY AND ANOTHER LOW IS EXPECTED TO PASS NORTH OF THE
LAKE THROUGH ONTARIO MID NEXT WEEK. GUIDANCE STILL FEATURES
DIFFERENCES ON TIMING OF THE LOW...BUT TUESDAY NIGHT OR WEDNESDAY
LOOKS LIKE THE BEST TIME FRAME. GUIDANCE ALSO SUGGESTS ANOTHER LOW
MOVES IN FROM THE SOUTHWEST NEXT THURSDAY.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
249 PM CDT Fri Aug 2 2013
.DISCUSSION...
Issued 248 PM CDT Fri Aug 2 2013
Early afternoon surface map showing the cold front had crossed
much of Wisconsin, then extended westward across southern Iowa to
along the Kansas/Nebraska border. Precipitation so far has been
pretty sparse across the area, with just some high-based very
light showers tracking just south of the I-72 corridor.
Subsidence in the wake of morning convection in northern Illinois
actually allowed for a good deal of clearing across southeast Iowa
and northern Illinois, although diurnal cumulus has been filling
in rather quickly the last couple hours. The clearing helped to
get the air more unstable, with CAPE`s of around 2000 J/kg across
the northern third of the state with little cap, as evidenced by
scattered storms forming around 2 pm just ahead of the front from
Moline to Chicago.
The primary forecast concern in the short term is with the
convective chances over the next 18-24 hours. Rain chances in the
longer range are also a concern due to MCS potential through the
first half of next week.
SHORT TERM...Tonight through Sunday...
Morning model runs have significantly struggled with the
convective trends thus far, so confidence in this part of the
forecast is lower than normal. The most recent HRRR model appears
to be closest to reality, and shows that the broken line of
showers and storms to our north will be drifting across areas
along and north of I-74 into the evening. Scattered storms
currently in Missouri should track eastward as well, affecting
the remainder of the forecast area. Precipitable water values of
1.75 to 2 inches should help produce some heavy rain with the
stronger storms. Can`t rule out some gusty winds and hail as well,
but wind shear overall is rather weak in our area and anything
that does approach severe levels should be the pulse type.
Overnight, the NAM and GFS already have the precipitation on the
wane with a faster push to the cold front, while the ECMWF and
Canadian models linger the showers/storms most of the night with a
slower frontal passage. Have gone with the highest PoPs in the
evening, but kept healthy chances over most of the area overnight.
Not too many changes needed for Saturday, as the frontal boundary
should be through most of the area by midday. Have kept the
northwest CWA dry all day, and continued with all areas north of
I-72 dry by afternoon. All precipitation should be out of the area
by early evening, as high pressure builds southeast into the
Midwest, and cooler/less humid air can be expected the rest of the
weekend.
LONG TERM...Monday through Friday...
Upper level pattern looking fairly agreeable among the GFS and
ECMWF models, with initial northwest flow flattening as a strong
cutoff low sinks southward across Manitoba. GFS remains stronger
with the high keeping our area dry into Monday, while the ECMWF
keeps us on the periphery of the MCS track across Missouri. Have
limited any PoPs to the far southwest for Sunday night and even
then just kept them at 20 percent. Next shortwave on Tuesday
should help boot the high eastward, but convection along the Gulf
Coast will help rob some of the return moisture advection for a
time, so have held off on any decent rain chances until Tuesday
night. Getting into midweek, a surface boundary will become quasi-
stationary as it becomes parallel to the upper flow. The model
differences widen at this point, with the GFS pushing the boundary
through us by late Wednesday night and the ECMWF keeping it north
of the area until Thursday evening. The ultimate position and
associated convective chances will come down to timing of fast
moving shortwaves between the upper low and a sprawling upper high
over the southern U.S. For now have favored a bit of a more
southern push with a period of drier conditions Wednesday night
and Thursday with increasing PoPs again after that.
Geelhart
&&
.AVIATION...
ISSUED 1248 PM CDT Fri Aug 2 2013
Latest satellite imagery is beginning to show CU-field developing
along/ahead of an approaching cold front across Iowa into
north-central Illinois. Think scattered showers/storms will form
in this area over the next 2 to 3 hours...potentially impacting
the northern KILX terminals after 20z. Further south...convection
may not develop at the I-72 TAF sites until early evening...when
upper wave currently over the Dakotas begins to enhance lift
across the region. Since areal extent and timing of convection
remains in question...have opted to only include VCTS at the
terminals. With increasing lift and the front dropping slowly
southward toward the area...will maintain predominant showers in
the forecast through much of the evening into the first part of
the overnight hours. As boundary sags southward...southwesterly
winds this afternoon will eventually decrease and become
light/variable overnight. Main aviation concern later in the
forecast is whether or not MVFR ceilings will develop along/behind
boundary. Current satellite imagery does not support
this...however 12z NAM continues to suggest low ceilings. Will
therefore maintain a brief period of MVFR ceilings at around
2500ft after FROPA late tonight into early Saturday. After
that...clearing skies and light northeasterly winds are
anticipated Saturday morning.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
357 PM EDT FRI AUG 2 2013
.SYNOPSIS...
ISSUED AT 351 PM EDT FRI AUG 2 2013
A PAIR OF UPPER LEVEL DISTURBANCES WILL COMBINE WITH A COLD
FRONTAL BOUNDARY TO PRODUCE SHOWERS AND THUNDERSTORMS ACROSS MUCH
OF THE REGION TONIGHT INTO EARLY SATURDAY. THE BELOW NORMAL
TEMPERATURES WILL CONTINUE SUNDAY AND MONDAY BEHIND THIS FRONT
WITH MAINLY DRY CONDITIONS. A WARM FRONT WILL APPROACH THE AREA
TUESDAY BRINGING THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 351 PM EDT FRI AUG 2 2013
PRIMARY SHORT TERM FORECAST CONCERN WILL BE ON CONVECTIVE POTENTIAL
TONIGHT INTO EARLY SATURDAY.
SHOWERS AND EMBEDDED THUNDERSTORMS HAVE SHIFTED EAST OF THE FORECAST
AREA THIS AFTERNOON AS ISENTROPIC UPGLIDE HAS WEAKENED THROUGH THE
DAY AND SHIFTED NORTH AND EAST OF LOCAL AREA. WATER VAPOR IMAGERY AT
18Z INDICATING A COUPLE OF SHORT WAVES OF INTEREST FOR TONIGHT/EARLY
SATURDAY. THE FIRST OF THESE SHORT WAVES CONTINUES TO DIG ACROSS THE
ARROWHEAD OF MINNESOTA ACROSS NORTHERN WISCONSIN. ANOTHER SMALLER
SCALE WAVE APPEARS TO BE KICKING OUT OF EASTERN NEBRASKA...WITH SOME
PRONOUNCED VEERING MID/UPPER LEVEL FLOW PER MERRIMAN PROFILER DATA
PAST HOUR BEHIND THIS SHORT WAVE. A 120 KNOT UPPER JET STREAK
DIGGING THROUGH BASE OF NORTHERN GREAT LAKES UPPER TROUGH WILL PLACE
LOCAL AREA INCREASINGLY IN MORE FAVORED RIGHT ENTRANCE REGION BY
LATE EVENING. VISIBLE SATELLITE IMAGERY TRENDS OVER PAST SEVERAL
HOURS HAVE BEEN TOWARD BUILDING CU ALONG PREFRONTAL TROUGH TYPE
FEATURE FROM THE QUAD CITIES INTO NORTHEAST ILLINOIS WHERE SFC DEW
POINTS HAVE POOLED INTO THE UPPER 60S TO AROUND 70. ABOVE MID/UPPER
LEVEL FORCING MECHANISMS SHOULD INTERACT WITH NARROW PREFRONTAL
TROUGH TYPE FEATURE TO INCREASE COVERAGE OF SCATTERED SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON ACROSS NORTHEAST ILLINOIS...AND
EVENTUALLY INTO NORTHERN INDIANA/SOUTHERN LOWER MICHIGAN AS LARGER
SCALE FRONTAL RESPONSE SHIFTS INTO THE AREA. RAP INITIALIZATION DATA
DOES INDICATE THE RELATIVE STABLE BUBBLE ACROSS NORTHERN INDIANA
GIVING WAY TO AXIS OF 100 HPA MLCAPES ON THE ORDER OF 1000 J/KG LATE
THIS AFTERNOON.
BASED ON HOW CURRENT SCENARIO SEEMS TO BE UNFOLDING...HAVE NOT MADE
MANY CHANGES TO SCT POPS TRANSITIONING TO LIKELY POPS EARLY THIS
EVENING ESPECIALLY SOUTHERN HALF AS FRONTAL CIRCULATION BEGINS TO
MATURE. EXPECTING SCATTERED CONVECTION TO GENERALLY MERGE INTO
LARGER AREA OF RAIN AND EMBEDDED THUNDERSTORMS AS THIS OCCURS. SOME
DECENT RAINFALL AMOUNTS POSSIBLE ESPECIALLY SOUTHERN HALF GIVEN
MOISTURE POOLING ALONG THE FRONT AND INCREASING FRONTOGENETIC
RESPONSE LATER THIS EVENING. A FEW STRONGER CELLS ARE POSSIBLE LATE
AFTERNOON/EARLY EVENING THROUGH ABOUT 00Z ACROSS ESPECIALLY WESTERN
HALF GIVEN FAIRLY ROBUST DEEP LAYER SHEAR...BUT OVERALL SEVERE
THREAT SHOULD REMAIN ISOLATED DUE TO MARGINAL INSTABILITY PROFILES.
GENERALLY UTILIZED SREF IDEA FOR TIMING FRONTAL PROGRESSION INTO
SATURDAY MORNING WHICH LARGELY SUPPORTS GOING FORECAST SO NO
SIGNIFICANT CHANGES MADE TO SATURDAY POPS WITH BULK OF PRECIP
SHIFTING SOUTH OF THE AREA LATE MORNING.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 351 PM EDT FRI AUG 2 2013
BRIEF RETURN TO TRANQUIL WEATHER EXPECTED FOR EARLY NEXT WEEK.
SHORTWAVE RIDGING/SUBTLE MIDLEVEL HEIGHT RISES AND ANTICYCLONIC LOW
LEVEL FLOW WILL BRING DRY CONDITIONS BEGINNING SATURDAY NIGHT AS THE
COLD FRONT EXITS OUR AREA. LIGHT NORTHERLY WINDS/CAA AND DECREASING
CLOUDS SHOULD ALLOW FOR A COOL NIGHT WITH LOWS DROPPING INTO THE LOW
TO MID 50S PER CONSENSUS OF LATEST RAW AND STATISTICAL GUIDANCE.
STRONG NEGATIVE THETA-E ADVECTION WILL LEAD TO MOSTLY SUNNY SKIES ON
SUNDAY WITH JUST ENOUGH BOUNDARY LAYER MOISTURE SEEN IN FORECAST
SOUNDINGS TO SUPPORT A FEW DIURNAL CU. 850MB TEMPS ALSO DROP INTO
THE SINGLE DIGITS BUT AMPLE SUN SHOULD PUSH AFTERNOON TEMPS INTO THE
MID 70S FOR MOST LOCATIONS. SURFACE HIGH WILL DRIFT OVERHEAD BY
SUNDAY NIGHT WITH ANOTHER COOL NIGHT IN THE LOW 50S EXPECTED. A FEW
AREAS IN OUR NORTHEAST MAY EVEN TOUCH UPPER 40S IF MIDLEVEL CLOUDS
HOLD OFF LONG ENOUGH. SLIGHT MODERATION OF CANADIAN AIRMASS WILL
ALLOW TEMPS ON MONDAY TO CLIMB A DEGREE OR TWO HIGHER BUT STILL ONLY
MID TO UPPER 70S AT BEST.
BY THE MIDDLE OF NEXT WEEK A PIECE OF ENERGY IS EXPECTED TO BREAK
OFF THE POLAR VORTEX AND PHASE WITH THE PERSISTENT HUDSON BAY CLOSED
LOW...ESTABLISHING A DEEP PV ANOMALY THAT IS EXPECTED TO MEANDER
ACROSS SOUTHERN CANADA FOR MUCH OF NEXT WEEK. MEANWHILE...SEVERAL
WEAK SHORTWAVES EMANATING FROM THE NORTHWEST CONUS TROUGH WILL BE
SHEARED ACROSS THE GREAT LAKES IN FAST WNW FLOW ALOFT ON THE SOUTH
SIDE OF AFOREMENTIONED ANOMALY. RETURN FLOW ON THE BACKSIDE OF
DEPARTING SURFACE HIGH WILL ALSO BEGIN TO ADVECT A SLIGHTLY WARMER
AND MORE MOIST/UNSTABLE AIRMASS BACK INTO THE REGION DURING THIS
TIME. NEEDLESS TO SAY NUMERICAL GUIDANCE IS STRUGGLING WITH THE
EVOLUTION OF THIS PATTERN. LATEST 12Z GFS IS CONTINUING TO TREND
TOWARD THE MORE CONSISTENT ECMWF IN SHOWING THE BEST PRECIP
POTENTIAL HOLDING OFF UNTIL LATE TUESDAY AND INTO WEDNESDAY BUT
CONTINUES TO SHOW SIGNIFICANT DIFFERENCES BY LATE IN THE WEEK.
CERTAINLY COULD BE A FEW SCATTERED SHOWERS FROM WAA/ISENTROPIC
ASCENT ON TUESDAY BUT WILL HIGHLIGHT WEDNESDAY WITH THE HIGHEST POPS
AS THE MAIN SHORTWAVE/COLD FRONT PUSH THROUGH THE REGION. WILL LEAVE
THE END OF THE WEEK DRY FOR NOW UNTIL THE MODELS GET A BETTER HANDLE
ON EVOLUTION OF DEEP CANADIAN VORTEX. SLIGHTLY WARMER TEMPS EXPECTED
NEXT WEEK IN SOUTHWEST FLOW AHEAD OF FRONT BUT STILL HOVERING NEAR
TO EVEN SLIGHTLY BELOW NORMAL FOR EARLY AUGUST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 153 PM EDT FRI AUG 2 2013
ISENTROPIC FORCING WILL CONTINUE TO SHIFT EAST OF THE AREA AND
WEAKEN OVER THE NEXT FEW HOURS. THIS WILL RESULT IN LINGERING
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS FAR NORTHEAST INDIANA TO
SHIFT EAST OF KFWA BY 19Z. VISIBLE SATELLITE IMAGERY DEPICTS SOME
ENHANCEMENT TO CU BACK ACROSS NORTHERN ILLINOIS ALONG WEAK
PREFRONTAL CONVERGENCE ZONE. LARGE SCALE FORCING WILL CONTINUE TO
INCREASE OVER THE NEXT SEVERAL HOURS AS UPPER LEVEL SHORT WAVE
ACROSS THE UPPER MIDWEST DROPS INTO THE GREAT LAKES REGION. WARM
SECTOR SHOULD BECOME INCREASINGLY MORE ACTIVE WITH SHOWERS AND
EMBEDDED THUNDERSTORMS BY THE 21Z-00Z TIMEFRAME. BASED ON
ORIENTATION OF PREFRONTAL CONVERGENCE ZONE...WOULD SUSPECT BEST
CHANCE OF SHRA/TSRA AT KFWA IN THE 00Z-05Z TIMEFRAME. CONFIDENCE IN
COVERAGE/DURATION OF ADDITIONAL SHOWERS AT KSBN SOMEWHAT LOW AND
HAVE CONFINED PRECIP MENTION TO TEMPO -SHRA IN THE 21Z TO 01Z
TIMEFRAME. WINDS TO BECOME LIGHT WEST/NORTHWEST BEHIND THE FRONT
TONIGHT WITH FOCUS FOR ADDITIONAL PRECIP LIKELY REMAINING SOUTH OF
KFWA ON SATURDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...AGD
AVIATION...MARSILI
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AREA FORECAST DISCUSSION
NWS WICHITA KS
1131 AM CDT FRI AUG 2 2013
.MESOSCALE DISCUSSION...
ISSUED AT 1133 AM CDT FRI AUG 2 2013
PERSISTENT MID-LEVEL WARM ADVECTION ZONE ACROSS SOUTH CENTRAL
KANSAS IN THE WAKE OF THE DEPARTING AND WEAKENING MESOSCALE
CONVECTION ACROSS SOUTHEAST KANSAS WILL BE FOCUS FOR RENEWED
SHOWERS AND STORMS INTO THE AFTERNOON. THE 12Z GFS AND TO A
LESSER EXTENT LATEST RUC SEEM TO HAVE DECENT HANDLE ON THIS
SCENARIO. THIS IN COMBO WITH MORE CLOUD COVER WILL HAMPER
MAX TEMPS AS WELL...SO HAVE UPDATED AND TWEAKED THEM DOWN
FOR AREAS GENERALLY EAST OF I-135. ADDITIONAL SURFACE BASED
CONVECTION MAY DEVELOP TOWARD PEAK HEATING FURTHER NORTH ACROSS
NORTH CENTRAL KANSAS AND TO OUR SOUTHWEST ALONG REMNANT MESO
OUTFLOW ACROSS SOUTHWEST KANSAS INTO NORTHWEST OKLAHOMA. THE
OVERALL CONFIDENCE ON AREAL COVERAGE AND PLACEMENT OF SAID
CONVECTION INTO THE EVENING IS RELATIVELY LOW...BASED ON HOW
THINGS EVOLVE DURING THE AFTERNOON. WHILE STRONG TO LOCALLY
SEVERE STORMS WILL BE POSSIBLE...THE MAIN RISK WILL CONTINUE
TO BE HEAVY RAINFALL AND THE FLOOD THREAT.
KED
&&
.SHORT TERM...(TODAY THROUGH SUNDAY MORNING)
ISSUED AT 329 AM CDT FRI AUG 2 2013
TODAY-TONIGHT: CURRENT CONVECTIVE COMPLEX OVER NE KS IS SLOWLY
PROPAGATING S-SE...AND EXPECT IT TO DROP SOUTH OVER SOUTHEAST KS
FOR THE MORNING HOURS. MOISTURE TRANSPORT LOOKS TO CONTINUE TO
POINT EAST INTO SE KS FOR THE MORNING HOURS..POSSIBLY LEADING TO
BACKBUILDING STORMS ACROSS THE FLINT HILLS AND SOUTHEAST KS FOR
THE MORNING HOURS. THIS COULD LEAD TO A MORNING FLASH FLOODING
THREAT FOR THIS AREA...SO HAVE DECIDED TO ISSUE A FLOOD WATCH FOR
THIS THREAT...WITH THE STORMS FINALLY WANING BY THE EARLY
AFTERNOON.
EXPECTING SOME KIND OF MESO INDUCED OUTFLOW BOUNDARY/DIFFERENTIAL
HEATING BAROCLINIC ZONE TO BE DRAPED OVER PORTIONS OF CEN KS TO
ALONG THE KS TURNPIKE FOR THE AFTERNOON/EVENING HOURS. THINK THE
ELEVATED MIXED LAYER WILL KEEP THINGS CAPPED OFF INITIALLY FOR
RENEWED CONVECTION ACROSS CEN KS...BUT CAP WEAKENS ENOUGH FOR STORMS
TO DEVELOP OVER CEN KS FOR THE EVENING HOURS. EXPECTING A VERY
UNSTABLE AIRMASS (SBCAPE 4500-4800 J/KG) TO BE LOCATED ALONG OR
JUST SOUTH OF THIS BOUNDARY...WITH INVERTED-V SOUNDINGS SUGGESTING A
DAMAGING WIND THREAT...WITH DEEP LAYER SHEAR EXPECTED TO BE AROUND
35-40 KTS. THINK THE STORMS WILL INITIALLY START OUT AS HP
SUPERCELLS SOMEWHERE ALONG INTERSTATE 70 OR POSSIBLY NEAR KRSL WHERE
A PSEUDO TRIPLE POINT WILL BE LOCATED AS THE SFC LOW PRESSURE AREA
IN SW KS INCHES FURTHER EAST INTO CEN KS.
850-700H MOISTURE TRANSPORT WILL FEED INTO THE INITIAL CONVECTION...
WITH THE STORMS CONGEALING INTO SOME FORM OF SOUTH-SE MOVING
MESOSCALE CONVECTIVE COMPLEX LATE THIS EVE OR TONIGHT. MOISTURE
TRANSPORT LOOKS TO SHIFT INTO SE KS BY SAT MORNING...WHICH COULD
LEAD TO SOME BACKBUILDING OF THE CONVECTION OVER SE KS INTO SAT
MORNING. WILL HAVE TO KEEP AN EYE ON THIS...GIVEN RECENT RAINFALL
AND POSSIBLE THREAT FOR FLOODING RAINFALL. STORMS WILL CERTAINLY BE
EFFICIENT RAINFALL PRODUCERS...GIVEN PRECIP WATER VALUES OF 150-200
PERCENT OF NORMAL. SO CERTAINLY COULD SEE ONE TO TWO INCH RAINFALL
AMOUNTS...ESPECIALLY OVER SE KS BY SAT MORNING. WITH THIS IN
MIND...HAVE DECIDED TO HEIGHTEN THE AWARENESS ONCE AGAIN BY
EXPANDING THIS MORNINGS FLOOD WATCH TO INCLUDE CEN KS AND SE KS
BEGINNING TNGT THROUGH SAT.
THE MORNING MCS WILL PLAY HAVOC WITH TEMPS FOR ERN SECTIONS
TODAY...WITH WIDESPREAD CLOUD COVER AND POSSIBLE MORNING SHOWERS.
THIS COULD LEAD TO COOLER TEMPS ACROSS SERN KS...WITH WARMER TEMPS
EXPECTED ACROSS CEN/S CEN KS SOUTH OF THE OUTFLOW BOUNDARY.
SAT-SUN MORNING: AS MENTIONED ABOVE...EXPECT SOME REMNANT MCS
ACTIVITY OVER SOUTHEAST KS FOR SAT MORNING. BUT FOCUS THAN SHIFTS
TO SAT AFTN/NIGHT...AS BOTH THE GFS AND NAM/WRF SHOW THE MAIN
SYNOPTIC COLD FRONT DROPPING SOUTH ACROSS THE FORECAST AREA FOR
SAT AFTERNOON. THIS WILL BE THE FOCUS FOR ANOTHER ROUND OF
SHOWERS/STORMS AND HEAVY RAINFALL ACROSS CEN AND SOUTH CEN KS FOR
SAT AFTN/NIGHT. LOTS OF CONCERN ABOUT FLOODING THREAT OVERNIGHT
SAT INTO EARLY SUN AS 850-700H MOISTURE TRANSPORT AND 850H FN-
CONVERGENCE WILL BE FOCUSED ACROSS SRN KS ALL NIGHT SAT NIGHT.
STORMS COULD TRAIN ALONG OR JUST NORTH OF THIS BOUNDARY ACROSS
MOST OF SOUTH CEN KS. SO WILL KEEP THE FLOOD WATCH GOING FOR MOST
OF THE AREA FOR SAT INTO SUN AS WELL. THIS PERIOD WILL HAVE TO BE
WATCHED...AS THIS EXTENDED FLOOD THREAT MAY LEAD TO SERIOUS
CONCERNS FOR LOCAL RIVERS/STREAMS ALREADY SWOLLEN BY RECENT RAINS.
KETCHAM
.LONG TERM...(SUNDAY AFTERNOON THROUGH THURSDAY)
ISSUED AT 329 AM CDT FRI AUG 2 2013
COULD SEE PORTIONS OF SRN KS DRY OUT SOME FOR THE REST OF THE DAY ON
SUN THRU TUE...AS WARM ADVECTION/MOISTURE TRANSPORT LOOKS TO SHIFT
BACK TO THE NORTH INTO NEB. NOT COMPLETELY SURE THAT AN MCS OR TWO
MIGHT DROP SOUTH INTO THE FORECAST AREA FOR MON OR TUE NIGHT...BUT
WITH UNCERTAINTY WILL NOT EXTEND THE FLOOD WATCH INTO THE BEGINNING
OF THE WEEK JUST YET. STAY TUNED.
KETCHAM
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 641 AM CDT FRI AUG 2 2013
NUMEROUS SHOWERS/THUNDERSTORMS WILL CONTINUE TO TRACK SOUTHEAST
ACROSS THE REGION THIS MORNING. WINDS WILL GRADUALLY VEER OUT FROM
THE NORTHEAST BACK AROUND TO THE SOUTHEAST FOR LATE THIS MORNING
AND AFTERNOON. MORE THUNDERSTORMS ARE EXPECTED TO REDEVELOP LATE
THIS AFTERNOON AND TONIGHT ACROSS THE EASTERN HALF OF KANSAS.
JAKUB
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 91 74 91 71 / 30 40 20 50
HUTCHINSON 91 71 89 70 / 20 40 30 60
NEWTON 88 72 89 70 / 30 40 30 60
ELDORADO 88 72 89 71 / 30 40 20 60
WINFIELD-KWLD 92 75 93 72 / 40 40 20 40
RUSSELL 96 71 88 69 / 20 30 30 60
GREAT BEND 95 70 89 69 / 20 20 30 60
SALINA 91 71 88 69 / 30 40 30 60
MCPHERSON 89 71 89 69 / 20 40 30 60
COFFEYVILLE 90 76 94 72 / 90 60 30 40
CHANUTE 87 74 89 71 / 40 70 30 50
IOLA 86 73 89 70 / 40 70 30 60
PARSONS-KPPF 88 75 91 71 / 60 60 30 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR KSZ052-053-069>072-
093>096-098>100.
FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH SUNDAY AFTERNOON
FOR KSZ032-033-047>051-067-068-083-092.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
203 PM CDT Fri Aug 2 2013
.SHORT TERM...(This Evening through Sunday night)
ISSUED AT 204 PM CDT FRI AUG 2 2013
A mid level wave was seen on satellite and via radar moving across
west Missouri. Convection has formed with this wave and was moving
east. Question is, how far east will it travel over the next
several hours, as it encounters drier air across the region. Will
gradually increase pops through the night. None of the models seem
to have a good handle on convective trends. The latest RAP model
is probably closest. Given low confidence in the latest solutions,
will not stray too far from persistence.
Even after a morning chance of convection, the probability for
more development will persist as a frontal boundary sags south
through the area late. Then, will decrease PoPs from north to
south Saturday night and focus them over the west and south into
Sunday and Sunday night.
Temperatures will be a combination of the latest MAV/MET MOS and
a blend of raw model output.
.LONG TERM...(Monday through Friday)
ISSUED AT 204 PM CDT FRI AUG 2 2013
For the beginning of the extended forecast period, namely Monday and
Tuesday, there has been a little less confidence on the eastward
extent of measurable PoP`s. During the last three days, attempted to
highlight the southwestern part of the WFO PAH county warning area,
namely southeast Missouri for rain chances. The low level surface
winds/moisture convergence appears pinned to southeast Missouri
through at least 12z (7am CDT) Tuesday. Although the SREF, GFS, and
ECMWF model precipitation parametrization schemes vary, the low
level frontal zones are similar during the aforementioned time
period. Given the lack if identifiable and consistent vorticity
advection above the frontal boundary, the decision was to limit the
precipitation chances close to the boundary, plus or minus 50 nm.
By late Tuesday night into Wednesday, the southern plains ridge
builds northward, shifting and sharpening the baroclinic zone and
frontal boundary further to the north. With this in mind, the higher
rain chances are shifted into southern Illinois, southwest Indiana,
and west Kentucky. This pattern remains intact through at least
Wednesday afternoon, when the upper ridge begins to flatten and
shift eastward across the lower Mississippi River valley. This
subtle pattern change, combined with a sharper meridional gradient
flow in the faster west to east flow, should lead to a much greater
tightening of the frontal boundary through the WFO PAH forecast area
next Thursday into Friday. Attempted to show a southward shift in
focus of higher PoP`s into toward the Arkansas and Tennessee borders
during this time period. It is also at this time that the highest
PoPs in the extended forecast period should be expected in the WFO
PAH forecast area.
Tuesday through next Friday will likely see max/min temperatures
approach or tie normals for this time of year, as the forecast area
is fully enveloped in the warm sector. With variable cloud cover,
heat index values should remain in check for most of next week. The
only exception may be next Wednesday afternoon, when heat index
values around 100 degrees may be possible along the southern border
counties of southeast Missouri.
&&
.AVIATION...
ISSUED AT 1158 AM CDT FRI AUG 2 2013
Will have ssw winds aob 10 kts rest of today with some cu and variable
high cloud cover. The high clouds will continue tonight. Late in the
night and through the morning hours Saturday, will carry prob30s for
light shra. Confidence in the coverage and evolution of convection
is quite variable in the model data. Confidence is very low. Thus the
conservative approach in the inclusion of any convection at all in
the TAFs.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...Noles
LONG TERM...Smith
AVIATION...Noles
AREA FORECAST DISCUSSION
NWS CARIBOU ME
659 PM EDT FRI AUG 2 2013
.SYNOPSIS...
UNSETTLED CONDITIONS ARE EXPECTED THROUGH THE WEEKEND WHILE AN
UPPER TROUGH REMAINS ACROSS THE REGION. THE NEXT CHANCE OF DRY
WEATHER WILL BE EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
700 PM UPDATE: ADJUSTED POPS/WX/SKY FOR LATEST RADAR AND SATELLITE
TRENDS...OTHERWISE FORECAST REMAINS ON TRACK.
AN OCCLUDED FRONT WILL CONTINUE TO PUSH ACROSS THE FORECAST AREA
LATE THIS AFTERNOON INTO THIS EVENING, ALONG WITH A LINE OF SHOWERS
AND THUNDERSTORMS. ONCE THIS ACTIVITY PUSHES INTO NEW BRUNSWICK,
EXPECT A MAINLY DRY NIGHT. SREF AND HRRR BOTH INDICATE FOG WILL
DEVELOP ACROSS DOWNEAST MAINE THIS EVENING AND REMAIN THROUGH THE
NIGHT. LOWS WILL GENERALLY BE IN THE MID AND UPPER 50S AREAWIDE.
FOR TOMORROW...A SHORTWAVE WILL TRAVERSE THROUGH THE FLOW ALOFT,
ALLOWING ANOTHER ROUND OF SHOWERS TO DEVELOP BY MID MORNING.
INSTABILITY, BOTH SURFACE-BASED AND ELEVATED, WILL BE FAIRLY
LIMITED, BUT WITH STEEPENING LAPSE RATES CAN`T COMPLETELY RULE OUT
AN ISOLATED THUNDERSTORM OR TWO. HIGHS WILL RANGE FROM AROUND 70
NORTH TO THE MID 70S SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
SHOWERS WILL WIND DOWN SATURDAY NIGHT AS THE UPPER SHORTWAVE MOVES
ON TO THE EAST AND DAYTIME HEATING IS LOST. THEN ANOTHER, STRONGER
UPPER TROUGH WILL PASS OVER THE REGION ON SUNDAY, LEADING TO MORE
SHOWERS AND THUNDERSTORMS. HIGHS WILL BE VERY SIMILAR TO THOSE ON
SATURDAY; AROUND 70 NORTH AND MID TO LOWER 70S DOWNEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
ANOTHER UPPER LEVEL DISTURBANCE WILL BE MAKING ITS WAY THROUGH
MAINE. A SURFACE LOW WILL BE SET UP JUST TO THE EAST OF THE
REGION. AS THIS DISTURBANCE CONTINUES TO SLIDE EAST IT WILL KEEP
CHANCES OF SHOWERS FOR MUCH OF THE REGION. IT DOES LOOK LIKE MOST
GUIDANCE INDICATES THAT BEST CHANCES WILL BE ACROSS THE NORTH WITH
LESSER CHANCES TO THE SOUTH. RIGHT NOW NOT CONFIDENT IN ANY
THUNDERSTORM ACTIVITY ESPECIALLY SINCE MOST PORTIONS OF THE REGION
WILL STAY MOSTLY CLOUDY. THAT SAID WILL KEEP THUNDER OUT OF THE
FORECAST FOR NOW.
ANOTHER PIECE OF ENERGY WILL MOVE THOUGH THE LARGER UPPER LEVEL
LOW WITH SHOWERS TAPERING OFF MONDAY NIGHT. TUESDAY WILL HAVE A
BREAK AS SPOKE OF ENERGY MOVES EAST AND SLIGHT RIDGING ATTEMPTS TO
MOVE EAST. WHILE THERE IS STILL SOME DIVERGENCE IN THE TIMING OF
THE NEXT SYSTEM FOR MID WEEK. IT DOES LOOK LIKE THE GUIDANCE IS
MORE IN LINE WITH EACH OTHER THIS MORNING. RIGHT NOW THE 06Z GFS
IS BRINGING THE PRECIP INTO MOST OF THE REGION BY THURSDAY MORNING
WHILE THE 00Z ECMWF HOLDS BACK TIL THURSDAY AFTERNOON AND EVENING.
THE LATEST 12Z GFS IS SLOWER WITH EXITING THE PRECIP AND IS TRYING
TO COME IN TO CONSISTENCY WITH OTHER GUIDANCE. THE BOUNDARY DOES
LOOK TO EXIT THE REGION LATER ON FRIDAY BRINGING SOME IMPROVEMENT
TO THE REGION.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: KBHB WILL HOLD ON TO 200-400FT CIGS THROUGH THE NIGHT.
FOG IS ALSO EXPECTED. ELSEWHERE VFR-MVFR CONDITIONS EARLY THIS
EVENING WILL DETERIORATE TO GENERALLY IFR CONDITIONS DUE TO LOW
CLOUDS AT ALL TAF SITES BY LATE THIS EVENING AND OVERNIGHT.
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS EVENING,
ESPECIALLY AT KFVE, THE PRECIPITATION WILL WIND DOWN OVERNIGHT.
CEILINGS WILL LIFT TO VFR AFTER 14Z SATURDAY, BUT MORE SHOWERS AND
POSSIBLE THUNDERSTORMS WILL KEEP THE THREAT OF OCCASIONAL MVFR/IFR
CONDITIONS THROUGH SATURDAY.
SHORT TERM: MVFR WITH OCCASIONAL IFR WILL BE POSSIBLE RIGHT
THROUGH THE WEEKEND INTO EARLY NEXT WEEK AS AN UPPER TROUGH KEEPS
SHOWERS AND THUNDERSTORMS AROUND.
&&
.MARINE...
NEAR TERM: NO HEADLINES ARE ANTICIPATED THROUGH SATURDAY. THE
MAIN CONCERN WILL BE AREAS OF FOG, ESPECIALLY TONIGHT, WITH
VISIBILITY REDUCED TO BELOW 1SM.
SHORT TERM: NO HEADLINES WILL BE NEEDED THROUGH SUNDAY AS WINDS
AND WAVES WILL REMAIN BELOW ADVISORY CRITERIA.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...HASTINGS
LONG TERM...JORDAN
AVIATION...HASTINGS/HASTINGS
MARINE...HASTINGS/HASTINGS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
333 PM EDT FRI AUG 2 2013
.SYNOPSIS...
UNSETTLED CONDITIONS ARE EXPECTED THROUGH THE WEEKEND WHILE AN
UPPER TROUGH REMAINS ACROSS THE REGION. THE NEXT CHANCE OF DRY
WEATHER WILL BE EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN OCCLUDED FRONT WILL CONTINUE TO PUSH ACROSS THE FORECAST AREA
LATE THIS AFTERNOON INTO THIS EVENING, ALONG WITH A LINE OF SHOWERS
AND THUNDERSTORMS. ONCE THIS ACTIVITY PUSHES INTO NEW BRUNSWICK,
EXPECT A MAINLY DRY NIGHT. SREF AND HRRR BOTH INDICATE FOG WILL
DEVELOP ACROSS DOWNEAST MAINE THIS EVENING AND REMAIN THROUGH THE
NIGHT. LOWS WILL GENERALLY BE IN THE MID AND UPPER 50S AREAWIDE.
FOR TOMORROW...A SHORTWAVE WILL TRAVERSE THROUGH THE FLOW ALOFT,
ALLOWING ANOTHER ROUND OF SHOWERS TO DEVELOP BY MID MORNING.
INSTABILITY, BOTH SURFACE-BASED AND ELEVATED, WILL BE FAIRLY
LIMITED, BUT WITH STEEPENING LAPSE RATES CAN`T COMPLETELY RULE OUT
AN ISOLATED THUNDERSTORM OR TWO. HIGHS WILL RANGE FROM AROUND 70
NORTH TO THE MID 70S SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
SHOWERS WILL WIND DOWN SATURDAY NIGHT AS THE UPPER SHORTWAVE MOVES
ON TO THE EAST AND DAYTIME HEATING IS LOST. THEN ANOTHER, STRONGER
UPPER TROUGH WILL PASS OVER THE REGION ON SUNDAY, LEADING TO MORE
SHOWERS AND THUNDERSTORMS. HIGHS WILL BE VERY SIMILAR TO THOSE ON
SATURDAY; AROUND 70 NORTH AND MID TO LOWER 70S DOWNEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
ANOTHER UPPER LEVEL DISTURBANCE WILL BE MAKING ITS WAY THROUGH
MAINE. A SURFACE LOW WILL BE SET UP JUST TO THE EAST OF THE
REGION. AS THIS DISTURBANCE CONTINUES TO SLIDE EAST IT WILL KEEP
CHANCES OF SHOWERS FOR MUCH OF THE REGION. IT DOES LOOK LIKE MOST
GUIDANCE INDICATES THAT BEST CHANCES WILL BE ACROSS THE NORTH WITH
LESSER CHANCES TO THE SOUTH. RIGHT NOW NOT CONFIDENT IN ANY
THUNDERSTORM ACTIVITY ESPECIALLY SINCE MOST PORTIONS OF THE REGION
WILL STAY MOSTLY CLOUDY. THAT SAID WILL KEEP THUNDER OUT OF THE
FORECAST FOR NOW.
ANOTHER PIECE OF ENERGY WILL MOVE THOUGH THE LARGER UPPER LEVEL
LOW WITH SHOWERS TAPERING OFF MONDAY NIGHT. TUESDAY WILL HAVE A
BREAK AS SPOKE OF ENERGY MOVES EAST AND SLIGHT RIDGING ATTEMPTS TO
MOVE EAST. WHILE THERE IS STILL SOME DIVERGENCE IN THE TIMING OF
THE NEXT SYSTEM FOR MID WEEK. IT DOES LOOK LIKE THE GUIDANCE IS
MORE IN LINE WITH EACH OTHER THIS MORNING. RIGHT NOW THE 06Z GFS
IS BRINGING THE PRECIP INTO MOST OF THE REGION BY THURSDAY MORNING
WHILE THE 00Z ECMWF HOLDS BACK TIL THURSDAY AFTERNOON AND EVENING.
THE LATEST 12Z GFS IS SLOWER WITH EXITING THE PRECIP AND IS TRYING
TO COME IN TO CONSISTENCY WITH OTHER GUIDANCE. THE BOUNDARY DOES
LOOK TO EXIT THE REGION LATER ON FRIDAY BRINGING SOME IMPROVEMENT
TO THE REGION.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: IFR CONDITIONS DUE TO LOW CLOUDS WILL PREVAIL AT ALL
TAF SITES THIS EVENING AND OVERNIGHT, WITH CEILINGS OCCASIONALLY
LIFTING TO MVFR THIS EVENING. VLIFR POSSIBLE AT KBHB LATE TONIGHT
DUE TO FOG. SHOWERS AND THUNDERSTORMS ARE LIKELY THIS EVENING,
ESPECIALLY AT KBGR, THE PRECIPITATION WILL WIND DOWN OVERNIGHT.
CEILINGS WILL LIFT TO VFR AFTER 14Z SATURDAY, BUT MORE SHOWERS AND
POSSIBLE THUNDERSTORMS WILL KEEP THE THREAT OF OCCASIONAL MVFR/IFR
CONDITIONS THROUGH SATURDAY.
SHORT TERM: MVFR WITH OCCASIONAL IFR WILL BE POSSIBLE RIGHT
THROUGH THE WEEKEND INTO EARLY NEXT WEEK AS AN UPPER TROUGH KEEPS
SHOWERS AND THUNDERSTORMS AROUND.
&&
.MARINE...
NEAR TERM: NO HEADLINES ARE ANTICIPATED THROUGH SATURDAY. THE
MAIN CONCERN WILL BE AREAS OF FOG, ESPECIALLY TONIGHT, WITH
VISIBILITY REDUCED TO BELOW 1SM.
SHORT TERM: NO HEADLINES WILL BE NEEDED THROUGH SUNDAY AS WINDS
AND WAVES WILL REMAIN BELOW ADVISORY CRITERIA.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...HASTINGS
LONG TERM...JORDAN
AVIATION...HASTINGS/HASTINGS
MARINE...HASTINGS/HASTINGS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1259 PM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1150 AM CDT FRI AUG 2 2013
BELIEVE PERSISTENT 850MB WAA/ISENTROPIC ASCENT WILL CONTINUE
THREAT OF SHRA/TSRA ACROSS CENTRAL AND E MO THIS AFTERNOON...AND
ALLOW THE THREAT TO WORK EAST WITH TIME. ALTHOUGH THERE IS
TYPICALLY A LULL IN WAA-DRIVEN PRECIP IN THE WARM SEASON DURING
THE AFTERNOON BELIEVE THAT RAIN-COOLED AMS OVER CENTRAL
MO...COMBINED WITH INCREASING INSTABILITY UPSTREAM OVER E
KS...WILL ALLOW CONVECTION TO CONTINUE TO PERCOLATE THROUGHOUT THE
AFTERNOON HOURS. RUC AND NAM ARE ACTUALLY FORECASTING A
SIGNIFICANT UPSCALE GROWTH IN THE CONVECTION IN OUR AREA DURING
THE AFTERNOON...AND ALTHOUGH THE LOCATION MAY BE OFF CANT TOTALLY
DISAGREE WITH THIS GENERAL SCENARIO. GOING POP TRENDS...WHICH HAS
LIKELY POPS FROM MID MO INTO W CENTRAL IL...STILL LOOK REASONABLE
AND WILL CONTINUE WITH THEM...AND FINE TUNE AS EXACT TRENDS
BECOME A BIT MORE CLEAR.
TRUETT
&&
.SHORT TERM...(THROUGH SUNDAY)
ISSUED AT 307 AM CDT FRI AUG 2 2013
MCS CURRENTLY OVER S NE AND N KS SHOULD CONTINUE TO PUSH SOUTHEAST
THROUGH THE EARLY MORNING HOURS WITH THE MAIN EFFECT OBSERVED
WITHIN OUR CWA THROUGH MIDDAY BEING BKN TO OVC DEBRIS CLOUDS. FAR
WESTERN SECTIONS OF THE CWFA MAY SEE A LIGHT SHOWER ON THE
EAST/NORTHEAST PERIPHERY OF THE STRATIFORM RAIN. ATTENTION THEN
TURNS TO THIS AFTERNOON AND EVENING AS SFC COLD FRONT SLOWLY
APPROACHES FROM THE NORTH/NORTHWEST. AFOREMENTIONED DEBRIS CLOUDS
MAY LIMIT INSTABILITY AND THUS SEVERE THREAT TODAY. HOWEVER...IF
MORE INSTABILITY IS REALIZED...THERE COULD BE A FEW STRONG TO
SEVERE STORMS GIVEN 30-40 KNOTS OF DEEP LAYER BULK SHEAR.
REGARDLESS...CHANCES OF SHOWERS AND STORMS DO LOOK TO INCREASE
FROM NORTHWEST TO SOUTHEAST AS A SHORTWAVE EMBEDDED WITHIN NW FLOW
ALOFT MOVES ACROSS THE MID MISSOURI VALLEY.
MODELS DEPICT LLJ BEING FOCUSING STRONG LL MOISTURE CONVERGENCE
AND INTERACTING WITH SFC BAROCLINIC ZONE OVER CENTRAL AND PORTIONS
OF SOUTHEAST MISSOURI OVERNIGHT FRIDAY. HAVE THEREFORE UPPED POPS
TO CATEGORICAL. ALSO COULD BE SOME LOCALLY HEAVY RAINFALL AS PWATS
ARE WELL ABOVE 2 INCHES IN SPOTS WITH A FAVORABLE CAPE PROFILE.
FOR THE WEEKEND...CLOSELY FOLLOWED THE GFS FOR SENSIBLE WEATHER AS
SFC FRONT SHOULD CONTINUE TO PROGRESS SOUTHWARD GIVEN NW MID/UPPER
LEVEL FLOW ALOFT AND FAIRLY STRONG PRESSURE RISES PROGGED BEHIND
THE FRONT. FOCUS FOR POPS THEN ALSO SHIFTS SOUTH INTO THE SOUTHERN
THIRD OF THE CWFA BY SATURDAY AFTERNOON WITH DRY/COLD ADVECTION
FURTHER TO THE NORTH. A MAJORITY OF THE AREA SHOULD STAY DRY
SATURDAY NIGHT AND INTO SUNDAY. EXCEPTION COULD BE PORTIONS OF
CENTRAL AND SOUTHEAST MISSOURI ONCE AGAIN WHERE 850 HPA FRONT IS
FORECAST TO NEVER QUITE MAKE IT THROUGH THE AREA. CHANCES OF
SHOWERS AND STORMS TO REMAIN THROUGH THE END OF THE WEEKEND IN
THIS REGION AS WARM MOIST AIR ALOFT RISES ABOVE THE SFC BAROCLINIC
ZONE TO THE SOUTH.
GOSSELIN
.LONG TERM...(MONDAY TO THURSDAY)
ISSUED AT 307 AM CDT FRI AUG 2 2013
HAVE CHC POPS THROUGHOUT THE EXTENDED AS THE PERIOD WILL CONTINUE
TO BE DOMINATED BY NW FLOW ALOFT. TIMING INDIVIDUAL SHORTWAVES
AND ATTENDANT COLD FRONT IS VERY DIFFICULT SO DID NOT ADJUST POPS
TOO MUCH FOR THIS PERIOD FROM CR INIT. TEMPERATURES FOR THE PERIOD
SHOULD RUN SLIGHTLY BELOW NORMAL DURING THE DAY AND NEAR NORMAL AT
NIGHT DUE TO EXPECTED CLOUD COVER AND POPS. A STRONG NORTHERN
VORTEX LOOKS TO COME SOUTH TOWARD THE CONUS SOMETIME LATE NEXT
WEEK WHICH SHOULD YIELD DRIER AND UNSEASONABLY COOL WEATHER BEHIND
ITS PASSAGE.
GOSSELIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1243 PM CDT FRI AUG 2 2013
AS MENTIONED IN SHORT TERM UPDATE...ISENTROPIC ASCENT SHOULD
CONTINUE TO FUEL SHRA/TSRA OVER MUCH OF THE AREA THIS AFTERNOON.
GETTING THE IMPRESSION THAT UIN MAY BE ON THE N FRINGES OF THE
MAIN QPF AREA...WITH OTHER TAFS EXPERIENCING SOMEWHAT MORE IN THE
WAY OF PRECIP. OUTSIDE OF COU WHERE RADAR DATA MAKES CONVECTIVE
TRENDS A BIT MORE CLEAR FOR THE NEXT COUPLE OF HOURS...HAVE USED A
BROAD BRUSH APPROACH FOR ONSET OF FIRST PRECIP AND THEN OF
TS...AND WILL SIMPLY USE NOWCAST TECHNIQUES TO TWEEK THESE TRENDS.
FOR NOW THESE BROAD BRUSH TRENDS HOLD ONTO VFR...BUT OBVIOUSLY
WITH THE ASCENT OF THE MODERATLY UNSTABLE AIRMASS STRONGER STORMS
COULD CERTAINLY PRODUCE MUCH LOWER CIGS/VSBYS. ZONE OF WAA IS
FORECAST TO DEVELOP S THIS EVENING...AND BELIEVE MUCH OF THE
PRECIP WILL BE SOUTH OF ALL TAF LOCATIONS HEADING INTO THE PREDAWN
HOURS. MOS GUIDANCE AS WELL AS SREF AVIATION PROBABIILTIES HINT AT
DETERIORATING CONDITIONS N OF THE SWD PUSHING FRONTAL BOUNDARY
DURING THE PREDAWN HOURS...AND HAVE INTRODUCED THIS TREND.
SPECIFICS FOR KSTL...
VFR SHOWERS SHOULD THREATEN STL AREA EARLY THIS AFTERNOON...WITH
MORE ROBUST CONVECTION POSSIBLE BY MID AFTERNOON AS WAA PERSISTS
AND ELEVATED AMS CONTINUES TO DESTABILIZE OVER MSVLY. AS MENTIONED
ABOVE...FOR NOW HAVE USED A BROAD BRUSH APPROACH FOR TIMING...AND
WILL USE RADAR TRENDS TO FINE TUNE THIS TIMING.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1151 AM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1150 AM CDT FRI AUG 2 2013
BELIEVE PERSISTENT 850MB WAA/ISENTROPIC ASCENT WILL CONTINUE
THREAT OF SHRA/TSRA ACROSS CENTRAL AND E MO THIS AFTERNOON...AND
ALLOW THE THREAT TO WORK EAST WITH TIME. ALTHOUGH THERE IS
TYPICALLY A LULL IN WAA-DRIVEN PRECIP IN THE WARM SEASON DURING
THE AFTERNOON BELIEVE THAT RAIN-COOLED AMS OVER CENTRAL
MO...COMBINED WITH INCREASING INSTABILITY UPSTREAM OVER E
KS...WILL ALLOW CONVECTION TO CONTINUE TO PERCOLATE THROUGHOUT THE
AFTERNOON HOURS. RUC AND NAM ARE ACTUALLY FORECASTING A
SIGNIFICANT UPSCALE GROWTH IN THE CONVECTION IN OUR AREA DURING
THE AFTERNOON...AND ALTHOUGH THE LOCATION MAY BE OFF CANT TOTALLY
DISAGREE WITH THIS GENERAL SCENARIO. GOING POP TRENDS...WHICH HAS
LIKELY POPS FROM MID MO INTO W CENTRAL IL...STILL LOOK REASONABLE
AND WILL CONTINUE WITH THEM...AND FINE TUNE AS EXACT TRENDS
BECOME A BIT MORE CLEAR.
TRUETT
&&
.SHORT TERM...(THROUGH SUNDAY)
ISSUED AT 307 AM CDT FRI AUG 2 2013
MCS CURRENTLY OVER S NE AND N KS SHOULD CONTINUE TO PUSH SOUTHEAST
THROUGH THE EARLY MORNING HOURS WITH THE MAIN EFFECT OBSERVED
WITHIN OUR CWA THROUGH MIDDAY BEING BKN TO OVC DEBRIS CLOUDS. FAR
WESTERN SECTIONS OF THE CWFA MAY SEE A LIGHT SHOWER ON THE
EAST/NORTHEAST PERIPHERY OF THE STRATIFORM RAIN. ATTENTION THEN
TURNS TO THIS AFTERNOON AND EVENING AS SFC COLD FRONT SLOWLY
APPROACHES FROM THE NORTH/NORTHWEST. AFOREMENTIONED DEBRIS CLOUDS
MAY LIMIT INSTABILITY AND THUS SEVERE THREAT TODAY. HOWEVER...IF
MORE INSTABILITY IS REALIZED...THERE COULD BE A FEW STRONG TO
SEVERE STORMS GIVEN 30-40 KNOTS OF DEEP LAYER BULK SHEAR.
REGARDLESS...CHANCES OF SHOWERS AND STORMS DO LOOK TO INCREASE
FROM NORTHWEST TO SOUTHEAST AS A SHORTWAVE EMBEDDED WITHIN NW FLOW
ALOFT MOVES ACROSS THE MID MISSOURI VALLEY.
MODELS DEPICT LLJ BEING FOCUSING STRONG LL MOISTURE CONVERGENCE
AND INTERACTING WITH SFC BAROCLINIC ZONE OVER CENTRAL AND PORTIONS
OF SOUTHEAST MISSOURI OVERNIGHT FRIDAY. HAVE THEREFORE UPPED POPS
TO CATEGORICAL. ALSO COULD BE SOME LOCALLY HEAVY RAINFALL AS PWATS
ARE WELL ABOVE 2 INCHES IN SPOTS WITH A FAVORABLE CAPE PROFILE.
FOR THE WEEKEND...CLOSELY FOLLOWED THE GFS FOR SENSIBLE WEATHER AS
SFC FRONT SHOULD CONTINUE TO PROGRESS SOUTHWARD GIVEN NW MID/UPPER
LEVEL FLOW ALOFT AND FAIRLY STRONG PRESSURE RISES PROGGED BEHIND
THE FRONT. FOCUS FOR POPS THEN ALSO SHIFTS SOUTH INTO THE SOUTHERN
THIRD OF THE CWFA BY SATURDAY AFTERNOON WITH DRY/COLD ADVECTION
FURTHER TO THE NORTH. A MAJORITY OF THE AREA SHOULD STAY DRY
SATURDAY NIGHT AND INTO SUNDAY. EXCEPTION COULD BE PORTIONS OF
CENTRAL AND SOUTHEAST MISSOURI ONCE AGAIN WHERE 850 HPA FRONT IS
FORECAST TO NEVER QUITE MAKE IT THROUGH THE AREA. CHANCES OF
SHOWERS AND STORMS TO REMAIN THROUGH THE END OF THE WEEKEND IN
THIS REGION AS WARM MOIST AIR ALOFT RISES ABOVE THE SFC BAROCLINIC
ZONE TO THE SOUTH.
GOSSELIN
.LONG TERM...(MONDAY TO THURSDAY)
ISSUED AT 307 AM CDT FRI AUG 2 2013
HAVE CHC POPS THROUGHOUT THE EXTENDED AS THE PERIOD WILL CONTINUE
TO BE DOMINATED BY NW FLOW ALOFT. TIMING INDIVIDUAL SHORTWAVES
AND ATTENDANT COLD FRONT IS VERY DIFFICULT SO DID NOT ADJUST POPS
TOO MUCH FOR THIS PERIOD FROM CR INIT. TEMPERATURES FOR THE PERIOD
SHOULD RUN SLIGHTLY BELOW NORMAL DURING THE DAY AND NEAR NORMAL AT
NIGHT DUE TO EXPECTED CLOUD COVER AND POPS. A STRONG NORTHERN
VORTEX LOOKS TO COME SOUTH TOWARD THE CONUS SOMETIME LATE NEXT
WEEK WHICH SHOULD YIELD DRIER AND UNSEASONABLY COOL WEATHER BEHIND
ITS PASSAGE.
GOSSELIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 615 AM CDT FRI AUG 2 2013
A BIT OF A MESSY FORECAST. MODELS DID NOT HAVE THE MCS OVER
EASTERN KANSAS AND WESTERN MISSOURI VERY WELL FORECAST AT ALL.
THUS DO NOT HAVE A LOT OF CONFIDENCE ON THEIR SOLUTIONS FOR THE
NEXT 24 HOURS. TREND SEEMS TO BE SO DEVELOP ANOTHER MCS OVER
SOUTHWEST MO...AND PERHAPS ANOTHER TO THE NORTH FROM NORTHEAST MO
MOVING EAST INTO ILLINOIS. PLUS THERE WILL LIKELY BE SCATTERED
DEVELPMENT DUE TO OUTFLOW BOUNDARIES. SURFACE FRONT FORECAST TO
DROP INTO NORTHERN MO THIS EVENING. POSITION OF FRONT MAY CLARIFY
WHERE THE RAIN COMPLEX(ES) FORM. GIVEN THE LACK OF CLARITY WILL GO
WITH VICNINTY OR NOW...EXCEPT FOP UIN WHERE THE CHANCE FOR EVENING
TO LATE NIGHT DEVELOPMENT APPEARS TO BE A LITTLE BETTER.
SPECIFICS FOR KSTL...WILL GO WITH VICNINTY THUNDER FOR THIS
AFTERNOON AS OUTFLOWS MAY HELP TO TRIGGER SCATTERED ACTIVITY. NOT
AT ALL CERTAIN ABOUT OVERNIGHT DEVELOPMENT DUE TO THE MODELS
TRENDING TO GO NORTH AND SOUTHWEST OF STL WITH DEVELOPMENT. A LATE
NIGHT VICINITY SEEMS SUFFICIENT FOR NOW.
JPK
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 86 72 87 66 / 40 60 50 10
QUINCY 84 67 82 62 / 60 60 30 5
COLUMBIA 82 69 87 66 / 70 70 50 20
JEFFERSON CITY 83 71 88 67 / 70 80 50 30
SALEM 86 69 83 64 / 30 60 50 10
FARMINGTON 86 70 84 68 / 40 70 70 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1241 PM CDT FRI AUG 2 2013
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
MAIN CONCERN IS POTENTIAL TSRA LATER THIS AFTN. STORM DEVELOPMENT
IS REVOLVING AROUND A SFC BNDRY ALONG THE NEB...SD BORDER WHICH IS
EXPECTED TO DRIFT SLOWLY SOUTH OVER THE NEXT SEVERAL HOURS. AREAL
COVERAGE IS SOMEWHAT IN QUESTION...BUT THINK AT LEAST REASONABLE
TO INCLUDE TEMPO GROUPS AT KOFK AND KOMA. LESS CONFIDENT ANY
CONVECTION WILL MOVE INTO KLNK...THUS LEFT DRY. OTHERWISE...VFR
THRU THE FCST PD.
DEE
PREV DISCUSSION... /ISSUED 310 AM CDT FRI AUG 2 2013/
DISCUSSION...
A RELATIVELY UNSETTLED WEATHER PATTERN WILL CONTINUE OVER OUR PART
OF THE COUNTRY INTO NEXT WEEK AS WE REMAIN UNDER FAST WEST TO
NORTHWEST FLOW ALOFT BETWEEN LARGE/DEEP UPPER LOW IN CANADA AND
BROAD HIGH IN THE SOUTHERN STATES. SEVERAL IMPULSES WILL WORK
THROUGH THIS FLOW THROUGH NEXT WEEK...BRINGING OCCASIONAL
THUNDERSTORM CHANCES AS SURFACE FRONT WOBBLES NORTH/SOUTH
AHEAD/BEHIND EACH WAVE.
FOR TODAY...MOST THUNDERSTORM ACTIVITY ASSOCIATED WITH THURSDAY
AFTERNOON/EVENING CONVECTION HAS SHIFTED SOUTH OF OUR AREA. HOWEVER
STRENGTHENING LOW LEVEL JET IN CENTRAL NEBRASKA HAS FIRED ADDITIONAL
STORMS IN SOUTH CENTRAL SOUTH DAKOTA. THIS ACTIVITY WILL LIKELY
DRIFT/DEVELOP EAST AND SOUTHEAST INTO NORTHEAST NEBRASKA AS LOW
LEVEL JET BECOMES SOUTHWESTERLY WITH TIME THIS MORNING. MODELS WERE
NOT HANDLING THIS PRECIPITATION PARTICULARLY WELL...BUT A BLEND OF
RAP AND HRRR SOLUTIONS OFFERS SOME RELIABILITY. EXPECT RAIN WITH
EMBEDDED STORMS CURRENTLY IN SOUTH CENTRAL NEBRASKA TO SPREAD ACROSS
THE SOUTHWEST THIRD OF THE CWA THROUGH MID MORNING WITH A DECREASING
TREND INTO EARLY AFTERNOON. SEVERE STORMS ARE NOT ANTICIPATED AS
ATMOSPHERE WAS WORKED OVER FAIRLY WELL OVERNIGHT. ANOTHER ROUND OF
STORMS COULD THEN DEVELOP IN THE MID TO LATE AFTERNOON AS A
SHORTWAVE EJECTS FROM THE HIGH PLAINS OF WYOMING/MONTANA AND SLIDES
SOUTHEAST. STORMS WOULD MOST LIKELY FORM IN SOUTH CENTRAL SOUTH
DAKOTA OR NORTH CENTRAL NEBRASKA THEN SPREAD SOUTHEAST ACROSS THE
WESTERN CWA DURING THE LATE AFTERNOON AND EVENING. SURFACE DEW
POINTS ARE FORECAST TO APPROACH 70...HELPING TO GENERATE 3000 J/KG
OR GREATER SURFACE-BASED CAPE OVER PARTS OF THE CWA. EXACT AXIS OF
HIGHEST INSTABILITY WILL BE AFFECTED BY ONGOING ACTIVITY THIS
MORNING...BUT LOOKS LIKE IT WILL SET UP OVER THE SOUTHERN HALF OF
OUR AREA. FARTHER NORTH...FASTER MID LEVEL FLOW WILL YIELD 50KT OF
BULK SHEAR...SO ANY STORMS THAT WORK INTO NORTHEAST NEBRASKA WILL BE
POTENTIALLY SEVERE AS WELL.
CONVECTION SHOULD BE SETTLING SOUTH OF NEBRASKA AFTER MIDNIGHT AS
SHORTWAVE MOVES OFF TO THE EAST. MOST OF SATURDAY THEN LOOKS DRY
WITH FOCUS FOR STORMS IN THE HIGH PLAINS. THEN THE NEXT SHORTWAVE
SHOULD BE ROLLING INTO THE AREA SATURDAY NIGHT SETTING UP ANOTHER
ROUND OF STORMS AS LOW LEVEL JET ONCE AGAIN DRIVES CONVECTION IN
WARM ADVECTION REGIME. THIS CONVECTION WILL LIKELY LINGER INTO AT
LEAST SUNDAY MORNING BEFORE MOVING OFF TO THE SOUTHEAST.
MUCH OF THE SAME IS FORECAST FOR NEXT WEEK. MONDAY OFFERS THE BEST
CHANCE FOR A DRY FORECAST BEFORE A STRONGER SHORTWAVE PUSHES A FRONT
THROUGH OUR AREA TUESDAY...WHICH THEN LIFTS BACK NORTH ON WEDNESDAY.
WILL NOT CHANGE FORECAST MUCH FROM GOING NUMBERS TUESDAY THROUGH
THURSDAY AS TIMING SHORTWAVES THIS FAR OUT IS DIFFICULT. HOWEVER
PATTERN CERTAINLY FAVORS AT LEAST A CHANCE FOR STORMS EACH DAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS BUFFALO NY
403 PM EDT FRI AUG 2 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL REMAIN JUST NORTH OF THE REGION THROUGH THE
WEEKEND. A FEW SYSTEMS WILL SWING ALONG THE BOTTOM SIDE OF THE LOW
AND BRING SOME SHOWERS AND THUNDERSTORMS TO WESTERN NEW YORK...BUT
OVERALL THE WEEKEND WILL FEATURE MOSTLY DRY CONDITIONS WITH
TEMPERATURES SLIGHTLY BELOW AVERAGE.
&&
.NEAR TERM /THROUGH SATURDAY/...
THE UPPER LEVEL PATTERN FEATURES A LOW NEAR HUDSON BAY WITH A 140KT
JET OVER THE UPPER MI PENINSULA. THIS JET IS FORECAST TO PASS BY
JUST NORTH OF LAKE ONTARIO OVERNIGHT AND BRING A SHORTWAVE TROUGH
ACROSS THE REGION IN THE PROCESS. A WEAK SURFACE FRONTAL ZONE WILL
ACCOMPANY THE UPPER LEVEL FEATURES AND BRING A LIKELIHOOD OF SHOWERS
AND THUNDERSTORMS FOR MUCH OF WESTERN NY AND EVENTUALLY THE EASTERN
LAKE ONTARIO REGION TONIGHT.
MEANWHILE A THIN LAKE BREEZE CONVERGENT ZONE SOUTH OF LAKE ONTARIO
CONTINUES TO PRODUCE CONVECTION FROM NIAGARA COUNTY EAST TO METRO
ROC. EXPECT THIS TO EVOLVE INTO ITS OWN EASTWARD MOVING LINE LATER
TONIGHT...OR WEAKEN/MERGE WITH UPSTREAM CONVECTION. EITHER WAY...A
HIGH LIKELIHOOD OF SHOWERS AND THUNDERSTORMS LOOKS GOOD FOR THE
GENESEE VALLEY/FINGER LAKES REGION AT SOME POINT DURING THE
EVENING.
SUCCESSIVE RUNS OF THE HRRR AND LAST NIGHTS SSEO HAVE HANDLED
ONGOING AND UPSTREAM DAYTIME CONVECTION FAIRLY WELL AND WILL
GENERALLY USE THEM AS A GUIDE FOR THE TIMING AND PROBABILITY OF
PRECIPITATION TONIGHT TOGETHER WITH SREF DATA.
THE CURRENT CONVECTION OVER EAST CENTRAL MI SHOULD THEREFORE
CONTINUE TO EVOLVE AND MOVE SE INTO SOUTHERN ONTARIO AND THEN WEAKEN
SOME EARLY THIS EVENING BEFORE SOME REDEVELOPMENT FORMS OVERHEAD
/OVER FAR WESTERN NY/ OR JUST UPSTREAM LATER EVENING...PROBABLY
AROUND OR JUST AFTER SUNSET. THE RESULTING CONVECTION IS THEN
EXPECTED TO CONTINUE EASTWARD ACROSS WESTERN NY AND INTO THE
GENESEE VALLEY AND FINGER LAKES REGION BEFORE MIDNIGHT. EAST OF
LAKE ONTARIO...EXPECT DISORGANIZED CONVECTION FOR THE REMAINDER OF
THE AFTERNOON AND INTO THE EVENING...WITH A MORE CONSOLIDATED LINE
OF STORMS MOVING THROUGH TOWARD OR SHORTLY AFTER MIDNIGHT.
THEREFORE NEARLY ALL LOCATIONS HAVE A LIKELIHOOD OF MEASURABLE
RAIN...BUT ONLY FOR A FEW HOURS AT ANY LOCATION.
THE MAIN SURFACE FRONT SHOULD BE THROUGH THE REGION AFTER MIDNIGHT
WITH A DRY SECOND HALF OF THE NIGHT.
ON SATURDAY...A SHORTWAVE RIDGE WILL MOVE IN BEHIND THE WEAK COLD
FRONT AND SHOULD PROVIDE THE REGION WITH DRY WEATHER. DRIER AIR CAN
BE SEEN UPSTREAM OVER WI WITH STEADILY DROPPING DEWPOINTS.
FORECAST SOUNDINGS INDICATE AN INVERTED-V SOUNDING...INDICATING A
WELL MIXED YET DRY LOW AIRMASS...WITH A NEAR SATURATED LEVEL NEAR
850MB AND DRY AIR ABOVE ABOUT 600 OR 700MB. THUS AFTER A MOSTLY
CLEAR MORNING...EXPECT PLENTY OF AFTERNOON FLAT CUMULUS WITH A WEAK
CAP ABOVE ABOUT 700MB. THERE MAY BE AN ENHANCED LINE OF CUMULUS
ALONG THE LAKE ONTARIO CONVERGENT ZONE FROM ABOUT BUFFALO TO
ROCHESTER...BUT WILL NOT INCLUDE ANY PRECIPITATION AT THIS TIME WITH
THE MUCH DRIER AIRMASS IN PLACE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
SATURDAY NIGHT A SHORT WAVE TROUGH WILL BE DIGGING INTO THE BASE OF
THE PROLONGED UPPER LEVEL LOW THAT HAS REMAINED PARKED OVER AND TO
THE NORTH OF OUR AREA. THIS SHORTWAVE WILL BRING A REINFORCING SHOT
OF COOLER SUMMER-TIME AIR...ALONG WITH CHANCES FOR SHOWERS ALONG THE
SURFACE TROUGH. THIS TROUGH WILL DROP ACROSS THE NORTH COUNTRY
THROUGH THE NIGHT AND WILL CARRY CHANCE POPS HERE.
SUNDAY THIS SURFACE TROUGH WILL CONTINUE TO DROP SOUTHWARD WITH THE
BEST LIFT AND MOISTURE ALONG THE SHORTWAVE ACROSS THE FINGER LAKES
REGION. WILL CARRY HIGH CHANCE TO LOW LIKELY HERE...TRAILING TO
CHANCE POPS BACK ACROSS PORTIONS OF WESTERN NEW YORK. TOWARDS SW NEW
YORK STATE WHERE LIFT AND MOISTURE WILL BE MUCH LESS...THE REGION
WILL LIKELY REMAIN DRY. ALSO A FEW RUMBLES OF THUNDER ARE
POSSIBLE...MAINLY TO THE EAST WHERE LOW LEVEL LAPSE RATES WILL BE
STEEPEST UNDER THE COLD POOL ALOFT. WITH PARTLY TO MOSTLY CLOUDY
SKIES THROUGH THE AFTERNOON HOURS ALONG WITH 850 HPA TEMPERATURES OF
AROUND +5 TO +6C AFTERNOON TEMPERATURES WILL FEEL FALL-LIKE WITH
HIGHS ONLY IN THE 60S. THIS WILL BE ABOUT 10 DEGREES COOLER THAN
NORMAL.
SUNDAY NIGHT THIS SHORTWAVE AND MOISTURE WILL CARRY EASTWARD LEAVING
CLEARING SKIES AND LIGHT WINDS. HIGH PRESSURE WILL SETTLE TOWARDS
THE OHIO VALLEY...AND VALLEY FOG ACROSS THE SOUTHERN TIER IS LIKELY.
BY MONDAY MORNING TEMPERATURES AT 850 HPA WILL DROP TO AROUND +4
ACROSS THE NORTH COUNTRY AND +6C ACROSS THE SOUTHERN TIER. THIS WILL
LEAD TO COLD SUNDAY NIGHT LOWS WITH TEMPERATURES DROPPING BACK INTO
THE LOW 50S NEAR THE LAKES...AND LOW/MID 40S WELL INLAND ACROSS THE
SOUTHERN TIER AND NORTH COUNTRY. THESE READINGS WILL BE SOME 10
DEGREES BELOW NORMAL. HOWEVER THERE IS SOME UNCERTAINTY WITH THE
CLEARING SUNDAY NIGHT...AS THERE MAY BE SOME LAKE EFFECT
CLOUDINESS...AND LINGERING UPSLOPE LOW STRATUS WITH THE NORTHERLY
FLOW. IF THIS WERE TO OCCUR...LOWS OVERNIGHT WILL BE A FEW DEGREES
WARMER UNDER THESE CLOUDS.
MONDAY HIGH PRESSURE WILL REMAIN ACROSS THE EASTERN GREAT LAKES AND
OHIO VALLEY REGION. THIS WILL BRING FAIR WEATHER WITH PLENTY OF
SUNSHINE AND TEMPERATURES RECOVERING BACK TO NEAR SEASONAL LEVELS WITH
AFTERNOON HIGHS IN THE 70S. REMAINING DRY MONDAY NIGHT...AND
CONTINUED CHILLY WITH LOWS ABOUT 5-7 DEGREES BELOW THE NORM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THROUGH THE LONG TERM PERIOD AN UPPER LEVEL LOW WILL REMAIN JUST TO
OUR NORTH OF EASTERN CANADA WITH SEVERAL SHORTWAVES ROTATING THROUGH
THE FEATURE. THIS LOW WILL BEGIN TO WEAKEN...IMPART DUE TO BOTH
TELECONNECTIONS OF THE PNA AND NAO BECOMING MORE NEUTRAL THROUGH THIS
TIME PERIOD. THIS WEAKENING OF THE LOW WILL ALLOW FOR SOME WARMER
AIR TO BUILD BACK NORTHWARD...THOUGH JUST SEASONABLE...AS OPPOSED TO
THE BELOW NORMAL TEMPERATURES SINCE THE LAST WEEK OF JULY.
FOR TUESDAY HIGH PRESSURE AT THE SURFACE WILL START THE DAY OVER THE
EASTERN GREAT LAKES REGION...AND SLIDE TOWARDS THE EAST COAST
THROUGH THE DAY. ALOFT A SHORTWAVE RIDGE WILL REMAIN OVER THE
EASTERN GREAT LAKES REGION AS A SHORTWAVE TROUGH SLIDES THROUGH THE
WESTERN GREAT LAKES. THIS SHOULD ALLOW FOR A DRY DAY TUESDAY WITH
CLOUDS THICKENING THROUGH THE DAY. TEMPERATURES AHEAD OF A COLD
FRONT...AND WITH THE SOUTHERLY WIND MAY CLIMB TO A FEW DEGREES ABOVE
NORMAL TUESDAY...WITH MANY AREAS INTO THE UPPER 70S...AND LOWER 80S.
TUESDAY NIGHT WILL LIKELY REMAIN DRY AS THE SHORTWAVE SLIDES TOWARDS
THE CENTRAL LAKES...BUT THE MORE LIKELY TIME PERIOD FOR SHOWERS WILL
BE WEDNESDAY TO FRIDAY TIMEFRAME. THE GFS IS STILL A LOT FASTER THAN
THE ECMWF...WITH THE NEW 12Z ECMWF NOW BRINGING THE COLD FRONT
ACROSS THE REGION ON FRIDAY NOW. WILL CONTINUE WITH A CHANCE POP
WEDNESDAY THROUGH FRIDAY TO ACCOUNT FOR THE UNCERTAINTY...THOUGH
LIKELY AT SOME POINT IN THAT TIME FRAME SHOWERS AND THUNDERSTORMS
WILL OCCUR.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
A LAKE BREEZE CONVERGENT ZONE HAS SET UP SOUTH OF LAKE
ONTARIO...WITH MOST OF THE CONVECTION CURRENTLY NORTH OF KBUF-KROC.
THIS LINE MAY MERGE OR EVOLVE LATER THIS EVENING WITH ANOTHER
SHORTWAVE TROUGH MOVING SOUTHEASTWARD INTO SOUTHERN ONTARIO THIS
EVENING. BEHIND THE SHORTWAVE...EXPECT IMPROVING CONDITIONS TOWARD
SUNRISE WITH VALLEY FOG A POSSIBILITY IN THE SOUTHERN TIER.
IN TERMS OF FLIGHT CONDITIONS...MOST TAF LOCATIONS SHOULD REMAIN VFR
THROUGH 18Z SATURDAY...ALTHOUGH ANY THUNDERSTORM MAY BRIEFLY LOWER
CONDITIONS TO MVFR. WINDS OVERALL SHOULD SLOWLY VEER FROM SW TO NW
DURING THE COURSE OF THE TAF CYCLE AND GENERALLY REMAIN UNDER 15KTS.
OUTLOOK...
SATURDAY NIGHT THROUGH SUNDAY...MAINLY VFR WITH A SMALL CHANCE OF
SHOWERS. MONDAY...VFR.
MONDAY NIGHT AND TUESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS.
WEDNESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS/THUNDERSTORMS.
&&
.MARINE...
A WEAK COLD FRONT WILL CROSS THE REGION TONIGHT WITH A LIKELIHOOD OF
SHOWERS AND THUNDERSTORMS. WINDS WILL CONTINUE TO BE OUT OF THE
SOUTHWEST WITH SMALL CRAFT ADVISORY CONDITIONS ALONG THE EASTERN
SIDES OF THE LAKES THROUGH TONIGHT. WINDS SHOULD SLOWLY VEER TO THE
WEST OR WNW ON SATURDAY WITH SLIGHTLY LOWER WIND SPEEDS.
ANOTHER SHOT OF COLD AIR ON SUNDAY WILL THEN BRING RENEWED CHANCES
FOR SCA ADVISORIES AS WINDS AND WAVES INCREASE ON BOTH
LAKES...ESPECIALLY LAKE ONTARIO. COOL AIR ALOFT WILL ALSO MAINTAIN
THE RISK OF WATERSPOUTS THROUGH THE WEEKEND...ESPECIALLY NEAR ANY
LAKE EFFECT CLOUD BANDS AND CONVERGENCE ZONES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR
LOZ045.
&&
$$
SYNOPSIS...TJP/ZAFF
NEAR TERM...ZAFF
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...ZAFF
MARINE...ZAFF
AREA FORECAST DISCUSSION
NWS BUFFALO NY
218 PM EDT FRI AUG 2 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL REMAIN JUST NORTH OF THE REGION AND BRING
CHANCES FOR SHOWERS THROUGH THE WEEKEND...WITH BELOW AVERAGE
TEMPERATURES LASTING INTO AT LEAST EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
SHORTWAVE TROUGH MOVING EASTWARD ACROSS THE FINGER LAKES REGION THIS
AFTERNOON AND TAKING EARLIER CONVECTION WITH IT. STILL UNSTABLE
BEHIND THE SHORTWAVE WITH LAKE BREEZE CONVERGENCE STARTING TO SHOW
UP ALONG LAKE ONTARIO BREEZE. EXPECT RENEWED SHOWERS AND
THUNDERSTORMS ALONG THIS LINE LATER THIS AFTERNOON AND INTO THE
EARLY EVENING HOURS.
TONIGHT WILL HAVE TO DEAL WITH ANOTHER SHORTWAVE TROUGH WORKING ITS
WAY SOUTHEASTWARD THROUGH MI...AND INTO THE OH VALLEY. WESTERN NY
WILL BE ON THE NW SIDE OF THE ENERGY AND THUS THIS MAY GRAZE THE FAR
SOUTHWESTERN CORNER OF THE STATE. FOR NOW WILL FOLLOW THE SSEO AND
SUCCESSIVE RUNS OF THE HRRR WHICH BRING CONVECTION INTO MUCH OF
WESTERN NY BETWEEN ABOUT 03Z AND 06Z WITH THE PASSAGE OF A WEAK COLD
FRONT.
BEHIND THE COLD FRONT A WEAK SHORTWAVE RIDGE WILL END UP OVER
WESTERN NY FOR SATURDAY...WITH NO CONVECTION EXPECTED SAVE FOR A
SMALL BOUNDARY SOUTH OF LAKE ONTARIO. THIS TIME HOWEVER... THE
AIRMASS WILL BE DRIER COMPARED TO TODAY...WITH PRECIPITABLE WATER
DROPPING FROM OVER 1.5 INCHES THIS MORNING DOWN TO ABOUT 0.75 INCHES
BY SATURDAY. A WEAK CAP IS EXPECTED AS WELL WITH A THIN SATURATED
LAYER BETWEEN ABOUT 800 TO 600 MB.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
THE GENERAL PATTERN WILL CHANGE LITTLE...WITH AN UPPER LEVEL TROF
AXIS EXTENDING FROM HUDSON BAY TO NEW ENGLAND THROUGHOUT THE
PERIOD. ANOTHER SHORTWAVE WILL APPROACH SATURDAY EVENING...WITH
THIS LIKELY TO DEEPEN AND SLOW AS IT CROSSES LATE SATURDAY NIGHT
INTO SUNDAY. A CONSENSUS OF LATEST SREF/GFS/NAM/ECWMF GUIDANCE
DROPS 850 MB TEMPS TO ABOUT +5C...WHICH IS COOLER THAN PREVIOUS
MODEL CONSENSUS. THIS SHOULD GIVE SUNDAY QUITE A FALL-LIKE
FEEL...WITH COOL TEMPERATURES AND LOTS OF LAKE ENHANCED CLOUD
COVER. THE COMBINATION OF THE UPPER LEVEL SHORTWAVE AND LAKE
INDUCED CAPES OF 1000-1500 J/KG WILL RESULT IN SOME LAKE EFFECT
RAIN SHOWERS. EXPECT THESE TO BE CELLULAR IN NATURE RATHER THAN
ORGANIZED LAKE BANDS...BUT SHOULD BE FAIRLY WIDESPREAD LATE
MORNING AND EARLY AFTERNOON WITH THE PASSAGE OF THE SHORTWAVE.
COOL AIR ALOFT WILL BE FAVORABLE FOR GRAUPEL DEVELOPMENT...WHICH
WILL RESULT IN A LIMITED POTENTIAL FOR LIGHTNING...EVEN FROM LOW
TOPPED CELLS. HIGHS SHOULD BE IN THE UPPER 60S TO AROUND 70.
THE SHORTWAVE WILL GRADUALLY EXIT TO THE EAST SUNDAY NIGHT...WITH A
VERY SLOW CLEARING TREND EXPECTED AS COOL AIR ALOFT RESULTS IN LAKE
EFFECT CLOUDS. SURFACE HIGH PRESSURE IS FORECAST TO BUILD IN FROM
THE OHIO VALLEY LATE IN THE NIGHT...WITH DIMINISHING WINDS AND AT
LEAST A PARTIAL CLEARING LATE IN THE NIGHT. IT WILL BE QUITE
CHILLY...ESPECIALLY WHERE IT CLEARS OUT...WITH LOWS RANGING FROM THE
MID 40S TO THE MID 50S. BECAUSE OF THE VARIABLE CLOUD COVER...HAVE A
LOW FORECAST CONFIDENCE IN THE LOW TEMPERATURE FORECAST SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
EARLY NEXT WEEK THE UPPER LEVEL TROUGH AXIS SHIFTS JUST A TAD TO THE
EAST...AND HIGH PRESSURE NEAR THE SURFACE SHOULD SLOWLY MOVE SE INTO
THE OH VALLEY AND THEN OFF THE MID ATLANTIC COAST. THIS SHOULD
ENSURE AT LEAST ONE DAY OF DRY WEATHER - MONDAY...AND PROBABLY
TUESDAY AS WELL. 00Z GUIDANCE IS IN A BIT BETTER AGREEMENT...WITH
THE GFS/ECMWF/GGEM ALL FORECASTING A FAIRLY SIGNIFICANT UPPER LEVEL
TROF PASSAGE MID-WEEK. TIMING DIFFERENCES STILL EXIST...WITH
FORECAST BLENDING THE FASTER GFS WITH THE SLOWER ECMWF...WITH THE
BEST CHANCE FOR SHOWERS/THUNDERSTORMS ON WEDNESDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A WEAK SHORTWAVE TROUGH IS MOVING ACROSS CENTRAL NY AND PRODUCING A
BROKEN LINE OF THUNDERSTORMS OVER THE FINGER LAKES REGION NEW INTO
OSWEGO COUNTY. LATER THIS AFTERNOON EXPECT A LAKE BREEZE CONVERGENT
ZONE TO SET UP SOUTH OF LAKE ONTARIO...WITH ADDITIONAL THUNDERSTORM
DEVELOPMENT ROUGHLY ALONG THE NYS THRUWAY WITH POSSIBLE IMPACTS TO
KBUF-KROC. THIS SHOULD DIMINISH WITH THE LOSS OF DAYTIME HEATING.
LATER THIS EVENING...PROBABLY JUST AFTER SUNSET...ANOTHER SHORTWAVE
TROUGH EVIDENT ON SATELLITE IMAGERY NEAR NORTHERN MI WILL MOVE
SE....AFFECTING PORTIONS OF WESTERN NY.
IN TERMS OF FLIGHT CONDITIONS...MOST TAF LOCATIONS SHOULD REMAIN VFR
THROUGH 18Z SATURDAY...ALTHOUGH ANY THUNDERSTORM MAY BRIEFLY LOWER
CONDITIONS TO MVFR. WINDS OVERALL SHOULD SLOWLY VEER FROM SW TO NW
DURING THE COURSE OF THE TAF CYCLE AND GENERALLY REMAIN UNDER 15KTS.
OUTLOOK...
SATURDAY NIGHT THROUGH SUNDAY...MAINLY VFR WITH A SMALL CHANCE OF
SHOWERS. MONDAY...VFR.
MONDAY NIGHT AND TUESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS.
WEDNESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS/THUNDERSTORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE AGAIN TODAY...RESULTING IN MARGINAL
SMALL CRAFT ADVISORY CONDITIONS ACROSS THE EASTERN NEARSHORES OF
LAKES ERIE AND ONTARIO.
ANOTHER SHOT OF COLD AIR ON SUNDAY WILL THEN BRING RENEWED CHANCES
FOR SCA ADVISORIES AS WINDS AND WAVES INCREASE ON BOTH
LAKES...ESPECIALLY LAKE ONTARIO. COOL AIR ALOFT WILL ALSO MAINTAIN
THE RISK OF WATERSPOUTS THROUGH THE WEEKEND...ESPECIALLY NEAR ANY
LAKE EFFECT CLOUD BANDS AND CONVERGENCE ZONES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
LOZ045.
&&
$$
SYNOPSIS...TJP
NEAR TERM...AR/ZAFF
SHORT TERM...APFFEL
LONG TERM...APFFEL/ZAFF
AVIATION...ZAFF
MARINE...APFFEL/TJP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1247 PM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1247 PM CDT FRI AUG 2 2013
HIGH PRESSURE CONTINUES TO BUILD SOUTH OVER WESTERN AND CENTRAL
NORTH DAKOTA. LATEST RADAR AND SATELLITE IMAGERY SHOWS AN IMPULSE
OVER NORTH CENTRAL MONTANA WITH NUMEROUS SHOWERS PUSHING NORTHEAST
INTO FAR NORTHEAST MONTANA. ACTIVITY WEAKENS AS YOU MOVE INTO
WESTERN NORTH DAKOTA. STILL THINK WITH AFTERNOON INSTABILITY WE
WILL SEE SCATTERED SHOWERS AND PERHAPS A FEW THUNDERSTORMS BUT
CONTINUED THE TREND OF LESSENING OVERALL COVERAGE. CLOUDS
DISSIPATING BEHIND MORNING CONVECTION OVER THE SOUTHWEST HAS
ALLOWED TEMPERATURES TO RISE CLOSE TO FORECAST HIGHS SO BUMPED UP
TEMPERATURES JUST A BIT.
UPDATE ISSUED AT 1014 AM CDT FRI AUG 2 2013
HIGH PRESSURE WILL CONTINUE TO BUILD SOUTH FROM CANADA TODAY.
UPPER LEVEL IMPULSES ROTATING AROUND NORTHWEST U.S. UPPER LOW WILL
KEEP PRECIPITATION CHANCES OVER THE WEST TODAY...BUT WITH SURFACE
HIGH PRESSURE BUILDING SOUTH...PRECIPITATION WILL HAVE A HARD TIME
MAKING IT INTO CENTRAL NORTH DAKOTA...ESPECIALLY THE NORTH
CENTRAL. HAVE UPDATED POPS TO LIMIT PRECIPITATION CHANCES EAST OF
THE HIGHWAY 83 CORRIDOR. TEMPERATURES LOOK IN LINE BUT WILL TAKE A
CLOSER LOOK AROUND MIDDAY.
UPDATE ISSUED AT 629 AM CDT FRI AUG 2 2013
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ADJUSTED
THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. THE UPDATED GRIDDED
AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI AUG 2 2013
MAIN CONCERNS IN THE SHORT TERM WILL BE EXTENT/PLACEMENT OF SHOWERS
AND THUNDERSTORMS...AS FORECAST MODELS DIFFER ON HOW PRECIPITATION
FIELD WILL PLAY OUT.
CURRENTLY...SURFACE HIGH PRESSURE WAS CENTERED OVER NORTHERN
SASKATCHEWAN WITH THE RIDGE AXIS EXTENDING SOUTHEASTWARD ACROSS
NORTH CENTRAL AND EASTERN NORTH DAKOTA. MEANWHILE LOW PRESSURE WAS
CENTERED OVER WYOMING. AT UPPER LEVELS...A LOW/TROUGH WAS OVER THE
ROCKIES NEAR IDAHO/WESTERN MONTANA WITH SHORTWAVE ENERGY MOVING
THROUGH THE SOUTHWEST FLOW ALOFT OVER CENTRAL/EASTERN MONTANA. A
CLUSTER OF THUNDERSTORMS OVER SOUTHEASTERN MONTANA MOVED INTO
NORTHWESTERN SOUTH DAKOTA AND SOUTHWESTERN NORTH DAKOTA...ASSOCIATED
WITH THE UPPER LEVEL ENERGY IMPULSES. AS THE CONVECTION MOVED
EASTWARD IT ENTERED A MORE STABLE ENVIRONMENT OVER NORTH
DAKOTA...WHERE EFFECTIVE BULK SHEAR WAS LOW AND MOST UNSTABLE CAPE
WAS MINIMAL. THOUGH SHOWERS WERE OCCURRING IN SOUTHWESTERN NORTH
DAKOTA - LIGHTNING ACTIVITY HAD DECREASED GREATLY.
THE SREF SEEMS TO HAVE BEST CAPTURED CURRENT EXTENT OF SHOWERS OVER
THE DAKOTAS. THIS MODEL DEPICTS PRECIPITATION AREA EXPANDING
NORTHWARD AND EASTWARD INTO NORTH DAKOTA...SPREADING AS FAR AS MINOT
AND JAMESTOWN. HOWEVER THIS MODEL IS BULLISH REGARDING THE STRENGTH
OF THE UPPER LEVEL SHORTWAVE IMPULSES OVERCOMING THE LIMITING
FACTORS OF THE UPPER LEVEL RIDGE AND LACK OF ROBUST LOW LEVEL
MOISTURE. THE NAM AND GFS KEEP THE AREA OF PRECIPITATION MORE
CONFINED TO THE SOUTHWEST AND FAR SOUTH CENTRAL...MAINLY SOUTH OF
WILLISTON AND BISMARCK. THE RUC DEPICTS PRECIPITATION REMAINING WEST
AND SOUTH OF THE STATE UNTIL THIS AFTERNOON.
THE UPPER LEVEL SHORTWAVE ENERGY IS MOVING TOWARDS NORTH DAKOTA IN
SOUTHWEST FLOW ALOFT...EMERGING FROM THE AFOREMENTIONED ROCKIES
LOW/TROUGH...AND MOVING INTO THE DOWNSTREAM UPPER RIDGE OVER THE
WESTERN DAKOTAS. A STRONG HUDSON BAY LOW IS EXPECTED TO REMAIN
FAIRLY STATIONARY...KEEPING THE UPPER RIDGE IN PLACE. ALSO A DRY
SURFACE HIGH OVER SOUTH CENTRAL CANADA AND EXTENDING INTO THE
EASTERN DAKOTAS AND MINNESOTA WILL KEEP SURFACE DEWPOINTS IN THE
LOWER 50S AND LIMITING THE AVAILABLE LOW LEVEL MOISTURE.
THUS WILL KEEP HIGHER CHANCES IN THE FAR SOUTHWEST TODAY AND LESSER
CHANCES NORTHEASTWARD. SOME AFTERNOON HEATING MAY INCREASE THE
OVERALL INSTABILITY ACROSS THE REGION...BUT NO SEVERE STORMS ARE
ANTICIPATED IN NORTH DAKOTA. WILL KEEP SOME CHANCES OF
SHOWERS/THUNDER FOR TONIGHT AS WELL...BUT THE UPPER LEVEL RIDGE
BUILDS DURING THE NIGHT AND LESSEN THE CHANCES FOR PRECIPITATION.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI AUG 2 2013
VERY WEAK MID-LEVEL RIDGING NUDGING INTO THE NORTHERN PLAINS IS
PROGGED TO KEEP MOST OF THE REGION DRY SATURDAY. AN APPROACHING
SHORTWAVE WARRANTS MAINTAINING SLIGHT CHANCE POPS IN THE EXTREME
WEST SATURDAY.
THE AFOREMENTIONED SHORTWAVE IS FORECAST TO PUSH ACROSS THE REGION
SATURDAY NIGHT INTO SUNDAY. MAINTAINED HIGH-END CHANCE POPS FOR THIS
PERIOD AS UPPER FORCING APPEARS SUFFICIENT FOR CONVECTIVE
DEVELOPMENT. BOTH THE 00Z GFS/ECWMF PROG INCREASING MUCAPE VALUES
OVER SOUTHWESTERN AND SOUTH CENTRAL NORTH DAKOTA SUNDAY AFTERNOON.
HOWEVER...THE GREATEST MUCAPE VALUES (SOUTHWEST/SOUTH CENTRAL) ARE
DISPLACED FROM THE BEST UPPER LEVEL FORCING (EAST). WILL THEREFORE
KEEP SEVERE MENTION OUT OF THE ZONES AND HWO FOR NOW...BUT WILL
CONTINUE TO MONITOR FUTURE RUNS.
THE PERSISTENT NORTHWESTERLY FLOW ALOFT WILL MAINTAIN SLIGHT CHANCES
FOR PRECIP DAILY THROUGH THE END OF THE PERIOD. THE 00Z GFS/ECMWF
CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL LOW OVER HUDSON
BAY MONDAY DROPPING SOUTH ACROSS SOUTH CANADA AND POSSIBLY INTO THE
FAR NORTH CENTRAL CONUS NEXT WEDNESDAY THROUGH FRIDAY. IF THESE
SOLUTIONS VERIFY...THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL
TEMPERATURES DURING THE LATTER HALF OF NEXT WEEK. THE RAW GFS/ECMWF
MODEL SOLUTIONS PAINT HIGHS IN THE MID 60S (HIGHS IN THE MID 80S ARE
NORMAL FOR EARLY AUGUST) BY THURSDAY AUGUST 8. FOR NOW WILL CONTINUE
TO GO WITH A CONSERVATIVE BLENDED APPROACH AND FORECAST HIGHS IN THE
MID 70S FOR DAY 7 DUE TO THE UNCERTAINTY WITH FORECASTING OUT THAT
FAR IN ADVANCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1247 PM CDT FRI AUG 2 2013
AT 1 PM CDT...SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED OVER
CENTRAL NORTH DAKOTA WITH LOW PRESSURE IN WYOMING. AN UPPER LEVEL
SHORTWAVE WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORMS OVER
EASTERN MONTANA AND WESTERN NORTH DAKOTA. WILL KEEP A MENTION OF
THUNDER AT KDIK TODAY AND SHOWERS AT KISN. WILL NOT MENTION ANY
PRECIPITATION AT KMOT...KBIS AND KJMS. HIGH PRESSURE WILL BUILD
OVER THE AREA TONIGHT ENDING THE THREAT OF ANY SHOWERS IN THE WEST
AS WELL.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
339 PM CDT FRI AUG 2 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 338 PM CDT FRI AUG 2 2013
MCV PRECIPITATION EXITING THE FAR SOUTHEASTERN CWA AT MID
AFTERNOON...AND MONITORING THE TRAILING EDGE OF NOW SLOWLY
DISSIPATING COMPLEX OF SHOWERS AND ISOLATED THUNDER ACROSS
SOUTHEASTERN SD. SUPPORT FOR LATTER PRECIP IS MID LEVEL LIFT FORCING
WITH WAVE MOVING THROUGH NORTHEAST AND TAILING TOWARD CENTRAL SD.
FEATURE KEEPS CLIPPING ALONG LATE AFTERNOON AND INDICATION ON WATER
VAPOR LOOP FOR SLIGHTLY RISING HEIGHTS IN WHAT HAS BEEN A GRADUALLY
STABILIZED OVERALL AIRMASS AS PRECIPITATION HAS WORKED THROUGH. MID
LEVEL BOUNDARY REMAINS INTO THE NIGHT RIGHT ACROSS THE AREA...BUT
CANNOT REALLY FIND ANY DISTINCT FEATURE TO THINK IT WILL ACTIVATE
BEHIND FEATURE THIS AFTERNOON FOR QUITE SOME TIME. THEREFORE...
HAVE CUT BACK POPS FAIRLY QUICKLY FROM WEST TO EAST THROUGH THE
REMAINDER OF THE AFTERNOON. WHILE HRRR HAS HAD A PRETTY GOOD IDEA TO
EVOLUTION OF PRECIP TODAY...ITS TIMING HAS LEFT QUITE A BIT TO BE
DESIRED...AND LIKELY CONTINUES TOO SLOW OVERALL. RETAINED ISOLATED
THUNDER MENTION MAINLY THROUGH THE MISSOURI CORRIDOR EASTWARD
THROUGH NORTHWEST IOWA...AS WILL STILL HAVE A BIT OF ELEVATED
INSTABILITY TO WORK THROUGH...AND WOULD BE PRUDENT TO KEEP AN EYE TO
THE SOUTHERN END OF THE LINE AS MAY YET PULSE UP IN STRENGTH A BIT
AND PRODUCE A LITTLE HAIL. MUCH OF THE REMAINDER OF THE NIGHT SHOULD
REMAIN QUIET...WITH PARTLY TO MOSTLY CLOUDY SKIES AFTER PERHAPS A
SHORT PERIOD OF POST CONVECTIVE CLEARING.
LATER TONIGHT INTO EARLY SATURDAY...ANOTHER WAVE MOVING THROUGH THE
ROCKIES WILL LIKELY INITIATE NOCTURNAL DEVELOPMENT THROUGH THE HIGH
PLAINS. PROPAGATION OF COMPLEX SHOULD KEEP MOSTLY CLEAR OF THE
AREA...BUT POTENTIAL FOR SOMETHING DEVELOPING INITIALLY NORTH OF THE
BLACK HILLS TO CLIP THE FAR SOUTHWEST. EASTERN LOCATIONS WILL BE
PROTECTED OF SORTS BY RIDGE OF HIGH PRESSURE AND SOMEWHAT DRIER
NORTHEAST TO EAST LOW LEVEL FLOW. SHOULD BE FAIRLY OPEN TO MIX
TOWARD 850-800 HPA ON SATURDAY WHICH WOULD YIELD AN ABUNDANCE OF MID
70S TO NEAR 80 ACROSS THE AREA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 PM CDT FRI AUG 2 2013
FAIRLY ACTIVE WEATHER PATTERN CONTINUES FOR THE BULK OF NEXT WEEK
WITH SEVERAL WAVE DROPPING ACROSS THE NORTHERN PLAINS ALONG THE
NORTHWESTERLY UPPER LEVEL FLOW. OVERALL TEMPERATURE TRENDS REMAIN
BELOW NORMAL WITH ONLY MINOR WARMING TRENDS BACK INTO THE LOW AND
MID 80S...FOLLOWED BY COOLING INTO THE 70S BEHIND THE BOUNDARIES.
MID LEVEL BOUNDARY IS EXPECTED TO SET UP ACROSS WESTERN SOUTH DAKOTA
AND NEAR THE MISSOURI VALLEY SATURDAY EVENING. SOME SCATTERED TO
ISOLATED THUNDERSTORMS ARE EXPECTED TO FIRE TO THE WEST OF THE
FORECAST AREA BY AFTERNOON AND COULD DRIFT INTO OUR FAR WESTERN
COUNTIES IN THE EVENING AND OVERNIGHT. MODELS TRACK A MID LEVEL INTO
THE NORTHERN HIGH PLAINS ON SUNDAY AND THROUGH THE FORECAST AREA
SUNDAY NIGHT. WITH SOME WEAK INSTABILITY EXTENDING INTO SOUTH
CENTRAL SOUTH DAKOTA...SCATTERED CONVECTION WILL AGAIN INITIATE
ACROSS OUR WESTERN COUNTIES SUNDAY AFTERNOON AND TRACK ACROSS THE
REMAINDER OF THE FORECAST AREA OVERNIGHT.
MODELS A BIT MORE UNCERTAIN WITH THE TIMING OF WAVES IN THE
EXTENDED. THE GFS BRINGS ANOTHER DECENT SHORTWAVE THROUGH THE
FORECAST AREA MONDAY NIGHT...WHILE THE ECMWF AND GEM ARE MORE
SUBTLE. BETTER AGREEMENT IS SEEN TUESDAY NIGHT WITH A WAVE AND COLD
FRONT DROPPING THROUGH THE REGION. THIS SHOULD ALLOW A COOLER AND
DRIER PUSH TO BRING A BREAK TO THE ACTIVE WEATHER PATTERN WEDNESDAY
THROUGH FRIDAY. DID SCALE BACK ON THE SPOTTY PRECIPITATION CHANCES
GIVEN BY THE ALLBLEND IN THE EXTENDED WITH THE EXCEPTION OF SOUTH
CENTRAL SD WHICH COULD SEE SOME HIGH PLAINS CONVECTION DRIFT INTO
THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1248 PM CDT FRI AUG 2 2013
PERSISTENT PRECIPITATION ACROSS MUCH OF THE AREA AT MIDDAY WITH
FIRST CLUSTER OF SHOWERS IN FAR SOUTHEAST SOUTH DAKOTA AND
NORTHWEST IOWA...AND SECONDARY AREA SPREADING THROUGH CENTRAL SD.
FOR THE MOST PART...PRIMARILY VFR CONDITIONS CAN BE EXPECTED...
ALTHOUGH ANY HEAVIER SHOWERS OR ISOLATED THUNDERSTORMS MAY BRIEFLY
PUSH VISIBILITY TO MVFR. A FEW MVFR CEILINGS WILL ALSO LINGER
AROUND THE KSUX AREA THROUGH THE AFTERNOON. OVERALL...THUNDERSTORM
THREAT IS FAIRLY ISOLATED AND LIMITED TO THE SOUTHERN HALF OF THE
AREA...MAINLY SOUTH OF A CHAMBERLAIN TO SPENCER IA LINE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1248 PM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1057 AM CDT FRI AUG 2 2013
LOCATED NEAR PLATTE SD...MCV FROM OVERNIGHT CONVECTION HAS FLARED
UP QUITE AN AREA OF CONVECTION IN THE FSD CWA EARLY THIS
MORNING...AND EVEN ONE BRIEF PULSE TO A SEVERE HAILER IN THE FAR
SOUTHWEST. FOR THE CURRENT TIME... OTHER THAN SOME OF THE AREAS
ON THE SOUTHERN FLANK OF THE COMPLEX WHERE ELEVATED INSTABILITY
IS SOMEWHAT STRONGER...MOST OF THE AREA HAS DEGRADED TO A LARGE
STRATIFORM AREA WITH EMBEDDED CONVECTIVE ELEMENTS. TO SAY THE
SHORT RANGE MODELS HANDLED POORLY WOULD PERHAPS EVEN BE A
COMPLIMENT...OTHER THAN THE HRRR WHICH HAS HAD THE RIGHT
DEVELOPMENT/EVOLUTION TRENDS TO THE SOUTHEAST AREA... BUT DOES
NOT ADEQUATELY ACKNOWLEDGE THE MORE DYNAMICALLY FORCED AREA OF
SHOWERS/CONVECTION ACROSS THE NORTHWEST PORTIONS OF SD.
HAVE BOOSTED POPS CONSIDERABLY ACROSS THE SOUTHWEST 2/3 OF THE
AREA...AND MAY BE ALL BUT THE EXTREME NORTHEAST THAT EVENTUALLY
SEES A FEW SHOWERS...WITH THUNDER LIMITED TO WEST THROUGH SOUTH.
AS FAR AS SEVERE THREAT...APPEARS TO HAVE MOSTLY PASSED...
ALTHOUGH PERHAPS CANNOT IGNORE A MINIMAL THREAT FOR A MARGINAL
HAILER IN THE EXTREME SOUTH/SOUTHWEST DURING THE EARLY TO MID
AFTERNOON ALONG SOUTHERN PERIPHERY OF SECONDARY AREA OF CONVECTION
WHERE WILL HAVE PROXIMITY TO SLIGHTLY BETTER ELEVATED INSTABILITY.
PRECIP AND CLOUDS WILL HAVE A DEVASTATING IMPACT ON TEMPS TODAY...
AND IN ADDITION TO SLOWING THE DIURNAL TREND...SLASHED HIGHS BY
A SOLID 5-8F OVER MUCH OF THE AREA EXCEPT THE FAR EAST/NORTHEAST.
MAY HAVE TO DROP READINGS EVEN FURTHER...AND THIS WOULD BRING SOME
NEAR RECORD COLD HIGHS ONCE AGAIN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT FRI AUG 2 2013
CONFIDENCE ON CONVECTIVE DEVELOPMENT/EVOLUTION IS EXTREMELY LOW FOR
TODAY WITH NOT A SINGLE MODEL HANDLING OVERNIGHT CONVECTION WELL.
CURRENT RADAR SHOWING CONVECTION DEVELOPING OVER WESTERN SOUTH
DAKOTA VERY EARLY THIS MORNING...THOUGH NOT SURE IF ANY OF THIS
ACTIVITY WILL MAKE IT INTO OUR WESTERN ZONES WITH STORM MOTION TO
THE SOUTHEAST AND A MORE STABLE/DRIER ATMOSPHERE OVER OUR AREA. A
STATIONARY BOUNDARY IS SITUATED SOMEWHERE ACROSS THE AREA...THOUGH
VERY HARD TO DEFINE WITH SURFACE OBS...WITH ASSORTED OUTFLOW
BOUNDARIES AROUND THE REGION. THE ASSUMPTION AT THIS POINT IS THAT
MOST CONVECTIVE DEVELOPMENT WILL BE FOCUSED IN THE VICINITY OF THIS
BOUNDARY TODAY...WHERE EVER IT MAY END UP. IT IS PROGGED TO BE
DRAPED ACROSS OUR FAR SOUTH THIS AFTERNOON...SO KEPT THE HIGHER POPS
OVER THAT AREA AND UP THROUGH THE MISSOURI RIVER VALLEY WHERE
PROGGED INSTABILITY WILL BE GREATER. MODELS DO INDICATE THE
ATMOSPHERE BECOMING MORE STABLE THROUGH THE DAY AS BETTER
INSTABILITY IS SHUNTED TO THE SOUTH...SO THINK THAT THE BETTER
CHANCE OF ANY SEVERE WEATHER MAY BE TO THE SOUTH OF OUR CWA. THAT
BEING SAID...THE BEST CHANCE OF SEVERE STORM DEVELOPMENT IF IT WERE
TO OCCUR WOULD BE IN THE AFTERNOON THROUGH OUR LOWER SOUTH
CENTRAL/MISSOURI RIVER ZONES WHERE LINGERING INSTABILITY/STRONG
DIRECTIONAL SHEAR MAY EXIST. MODELS CONTINUE TO COME IN COOLER THAN
PREVIOUS RUNS WITH REGARD TO HIGHS TODAY UNDER AN EASTERLY LOW LEVEL
FLOW...SO DROPPED HIGHS A COUPLE MORE DEGREES...RUNNING GENERALLY
MID AND UPPER 70S...TO AROUND 80 TROUGH OUR SOUTHERN MOST IOWA ZONES.
BY TONIGHT...EXPECT ANY LINGERING THUNDERSTORM ACTIVITY IN OUR SOUTH
TO DIMINISH AS DRIER AIR CONTINUES TO FILTER INTO THE REGION AND THE
STATIONARY BOUNDARY PULLS OUT OF OUR AREA. 925 MB TEMPERATURES COOL
SLIGHTLY OVERNIGHT UNDER A NORTHEASTERLY LOW LEVEL FLOW...WITH LOWS
DROPPING INTO THE MID 50S TO NEAR 60.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI AUG 2 2013
FSD FORECAST AREA WILL BE UNDER THE INFLUENCE OF COOL CANADIAN HIGH
PRESSURE AND EASTERLY LOW LEVEL FLOW...MAKING FOR A COOL EARLY
AUGUST WEEKEND WITH HIGH TEMPS ONLY IN THE 70S. RETURN FLOW SETS UP
ACROSS WESTERN SODAK FOR SATURDAY NIGHT IN RESPONSE TO PAC NW VORT
MAX TRAVERSING THE UPPER RIDGE. MODELS NOW MOSTLY IN AGREEMENT WITH
INSTABILITY AXIS REMAINING SOUTH AND WEST...WITH A 850MB BOUNDARY
SITTING JUST SOUTH OF MO RIVER. HAVE CONCENTRATED HIGHEST CHANCE POPS
ACROSS THE MO RIVER VALLEY AREA AND WEST OF THE JAMES RIVER
ACCORDINGLY...BUT OVERALL HAVE LOWERED POPS FOR SUNDAY/SUNDAY
NIGHT. MUCAPES REMAIN BELOW 1000 J/KG AS WELL FOR SUNDAY SO SEVERE
WEATHER THREAT IS VERY LOW. ASSOCIATED LOW LEVEL COLD FRONT PUSHES
THROUGH SUNDAY OVERNIGHT AND FOR THE FIRST PART OF MONDAY WITH
SOME SCT CONVECTION STILL POSSIBLE.
CONTINUED FAST NORTHWEST FLOW ALOFT BETWEEN CANADIAN CLOSED LOW AND
SOUTHERN CONUS RIDGE WILL CONTINUE TO MAKE CONVECTIVE FORECASTING
VERY CHALLENGING. MODELS PICKING UP ON MORE SIGNIFICANT SHORT
WAVE/FRONT FROM CANADIAN LOW THAT SWINGS THROUGH ON MONDAY NIGHT
THROUGH TUESDAY OR TUESDAY NIGHT PER THE GFS OR ECMWF. LOOKS LIKE
SOME DECENT RETURN FLOW WITH GFS ADVERTISING VERY HIGH MUCAPES FOR
TUESDAY AFTERNOON ACROSS MUCH OF THE FORECAST AREA. DEEP LAYER
SHEAR 50 KTS TUESDAY AFTERNOON MAKES ORGANIZED CONVECTION A
POSSIBILITY. HOWEVER...WITH TIMING AND PLACEMENT ISSUES IN THE
MODELS AS OF LATE...CONFIDENCE OF ANY SEVERE THREAT IS LOW. WILL
MONITOR FOR CONSISTENCY IN SUBSEQUENT MODEL RUNS.
OTHERWISE RETROGRADING UPPER CANADIAN LOW WILL BRING EVEN COOLER
TEMPS FOR THE LATTER HALF OF THE WEEK...ALTHOUGH THE LATEST ECMWF IS
NOT QUITE AS BULLISH WITH THE COLD AIR ADVECTION AS IT WAS
YESTERDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1248 PM CDT FRI AUG 2 2013
PERSISTENT PRECIPITATION ACROSS MUCH OF THE AREA AT MIDDAY WITH
FIRST CLUSTER OF SHOWERS IN FAR SOUTHEAST SOUTH DAKOTA AND
NORTHWEST IOWA...AND SECONDARY AREA SPREADING THROUGH CENTRAL SD.
FOR THE MOST PART...PRIMARILY VFR CONDITIONS CAN BE EXPECTED...
ALTHOUGH ANY HEAVIER SHOWERS OR ISOLATED THUNDERSTORMS MAY BRIEFLY
PUSH VISIBILITY TO MVFR. A FEW MVFR CEILINGS WILL ALSO LINGER
AROUND THE KSUX AREA THROUGH THE AFTERNOON. OVERALL...THUNDERSTORM
THREAT IS FAIRLY ISOLATED AND LIMITED TO THE SOUTHERN HALF OF THE
AREA...MAINLY SOUTH OF A CHAMBERLAIN TO SPENCER IA LINE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...JM
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SPOKANE WA
231 PM PDT Fri Aug 2 2013
.SYNOPSIS...
Unsettled weather will continue this evening with rain showers
and a few thunderstorms. Lingering showers will be common near
the Canadian border through Saturday. Summer weather will return
next week with a warm up back to normal and small chances of
mainly mountain thunderstorms each day.
&&
.DISCUSSION...
Rest of today and tonight: Clouds continue to thin across
the East Slopes, Okanogan Highlands, and western Columbia Basin.
This has resulted in an increasing risk for convective showers and
isolated thunderstorms. The main threats with these storms will be
heavy rainfall given the juicy air mass in place (precipitable
water values near to over 1.00") and nearly stationary movement.
Per the last few runs of the HRRR which did a superior job with
the placement of the current convection...this activity this
evening is expected to expand/shift west toward the East Slopes of
the Cascades and portions of Douglas and Grant Counties. This
mainly focuses over northern sections of Chelan and
central/western Okanogan Counties but will need to be closely
monitored for more development closer to the larger burn scars
outside Wenatchee. There is still a risk that a few of these cells
will impact some of the scars from the Byrd, First Creek, and Goat
Fires of 2012.
Meanwhile, the deformation band over the se continues to
shrink and HRRR suggest this will continue to dissipate this
evening. These features tend to linger longer then expected and
this was evident with each run of the HRRR this afternoon which
now lingers the band through 02z. Partial clearing south of this
band has resulted in developing showers from the Blue Mtns to the
L-C Valley to the Camas Prairie. Nothing real strong but a stray
thunderstorm will be possible before sunset.
The next feature of note will be a stronger wave that will wrap
around the northern periphery of the low. This wave was over NW MT
today and has since crossed into SE BC. Some guidance dives this
wave along with a cluster of heavier showers into the northern
mountains this evening into the overnight periods but others,
including the latest run of the HRRR now keep this feature just
along or north of the border. Given the high degree of
uncertainty...we have kept at least a chance of showers for most
locations through the overnight periods but confidence is not
exceptionally high locations like Spokane, CDA, and the Palouse
will experience much more precipitation once the current
deformation band dissipates. /sb
Saturday through Monday night...A closed low that brought the
moist and unsettled weather will pull away from the area into
northern Montana on Saturday. This will bring about the beginning
of a warming and drying trend into Monday. However a broad upper
level trough will remain over the area with a weak short wave
clipping the Canadian border Sunday into Monday. This combined
with abundant low level moisture should provide adequate
instability for diurnally driven showers and mainly isolated
thunderstorms primarily along the East Slopes of the Cascades, and
northern mountains. The NAM model has uncapped CAPE values of
300-700 J/KG each afternoon in these areas. Weak shear values will
support mainly pulse type thunderstorms that last only brief
periods of time. However light steering flow will also be slow
moving storms that could produce locally heavy rain. JW
Tuesday through Friday...A struggle between a ridge trying to
poke its way into the region, and upper level troughs on either side of
the ridge will be ongoing for much of next week. While the ridge
may help keep things on the warm side of normal (by about 3 to 6
degrees), an active large scale trough over the central US will
likely allow thunderstorms to develop each afternoon over the
higher terrain. Our confidence is not high that the precipitation
will make it much off the terrain, at least until a better
organized weather system gets closer to the region. The models are
hinting at one such feature moving over the Inland Northwest by
the end of the week. If this were to occur, temperatures would
likely cool by a few degrees and precipitation chances would be
higher over a larger area. ty
&&
.AVIATION...
18Z TAFS...An expansive upper-level low over the region will bring
widespread showers and isolated thunderstorms to much of the region.
MVFR/IFR Cigs/Vis will be found under a persistent band of light to
moderate rain stretching across the Central ID Panhandle and
portions of SE WA including the Spokane-CDA Area. Further
west...light scattered showers currently should transition to
showers and isolated thunderstorms btwn 20-03z with the potential
for heavy rain and localized vis/cig restrictions and KMWH/KEAT/KOMK
will carry the highest threat for any thunder. The exception is
near the Camas Prairie and Blue Mtns where partial clearing could
lead to isold -tsra vcnty of KLWS into the early evening. Activity
will wane overnight but a weak midlevel disturbance is likely to get
hung over Ern Wa and keep a cluster of light showers into the early
morning. Showers will once again form along the higher terrain near
17z on Sat. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 55 74 57 84 61 87 / 50 30 10 10 10 10
Coeur d`Alene 53 74 53 83 55 85 / 60 40 10 10 10 10
Pullman 50 74 49 83 50 87 / 50 20 10 10 10 10
Lewiston 56 82 59 92 62 94 / 40 10 10 10 10 10
Colville 52 78 52 87 52 87 / 90 40 20 20 10 10
Sandpoint 51 71 47 81 49 82 / 80 60 30 10 10 20
Kellogg 50 74 51 82 54 84 / 60 40 10 10 10 10
Moses Lake 59 81 58 89 61 92 / 60 10 10 10 0 10
Wenatchee 61 81 61 90 65 92 / 40 20 10 10 0 10
Omak 60 84 57 89 59 92 / 90 30 20 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
320 PM CDT FRI AUG 2 2013
.VERY SHORT TERM...TONIGHT AND SATURDAY.
SURFACE COOL FRONT/DRYLINE HAS SHIFTED SOUTH. RENEWED CONVECTIVE
DEVELOPMENT IN NRN IL INVOF BETTER LOW LEVEL FRONTAL CONVERGENCE.
MUCH DRIER AIR ADVECTING SE INTO SRN WI PER ISODROSOTHERM ANALYSIS.
500 MILLIBAR PROGS SHOW ELONGATED/SHEARED VORT ACROSS THE CWA DURING
THE NIGHT. MID/HIGH LEVEL CLOUDS ON THE INCREASE INTO THE EVENING
ASSOCIATED WITH RAIN MOVING ACROSS NRN IA. THE HRRR BRUSHES THE
SOUTH WITH THIS. THE 00Z ECMWF HINTS AT THIS AS WELL WITH OTHER
MODELS SHOWING DRY AFTER 00Z. CONSSHORT POPS SKIRT THE FAR SOUTH
WITH SMALL POPS EARLY THIS EVENING. SEEMS REASONABLE AND WILL BLEND
WITH THE SRN NEIGHBORS.
NORTHWEST UPPER FLOW PERSISTS. ALL MODELS BRING A 500 MILLIBAR
SHORTWAVE ACROSS. THE NAM HAS THE STRONGER LOOK TO THIS FEATURE
WHILE OTHER MODELS SHOW A CONTINUATION OF THE MORE SHEARED LOOK TO
THE VORT PATTERN. BUFKIT SOUNDINGS SHOW THAT THE AIRMASS WILL BE DRY
AND STABLE SO STICKING WITH THE ADVERTISED DRY FORECAST. SURFACE
HIGH BUILDS IN FROM CANADA AND RIDGES SOUTHEAST INTO WRN GREAT
LAKES. 925 TEMPS 17-19C TRANSLATE TO MID TO UPPER 70S WITH SOME
COOLER TEMPS EVOLVING AS WINDS TURN MORE NE NEAR LAKE MICHIGAN.
.SHORT TERM...SATURDAY NIGHT THROUGH MONDAY.
SHORT TERM GUIDANCE IN GOOD AGREEMENT ON HIGH PRESSURE AND DRY
COLUMN IN CONTROL OF OUR WEATHER THROUGH SUNDAY. DAYTIME
TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL FOR EARLY AUGUST AS
NORTHWEST LOW LEVEL FLOW PERSISTS. WARMER AIR BEGINS TO SLOWLY
RETURN SUNDAY NIGHT AND MONDAY. 12Z NAM MOST AGRESSIVE SHOWING MCS
SKIRTING SOUTHWEST WI SUNDAY NIGHT DESPITE RELATIVELY WEAKER LOW
LEVEL RETURN FLOW. 12Z NAM APPEARS TO BE OVERDOING AMOUNT OF UPPER
LEVEL DIVERGENCE ASSOCD WITH 3H JET. EVEN THOUGH OTHER GUIDANCE
INCLUDING GFS AND ECMWF FOCUSES FARTHER WEST...LOW TO MID LEVEL RH
DOES INCREASE OVERNIGHT WITH WEAK LAYER Q-VECTOR CONVERGENCE
SPREADING INTO SRN WI. NOT ENOUGH CONFIDENCE AT THIS POINT TO
TOTALLY REMOVE POPS FOR LATER SUN NIGHT. WL CONTINUE POPS FOR
MONDAY AS WELL AS WEAK MID-LEVEL TROUGH APPROACHES AND COLUMN
MOISTURE CONTINUES TO INCREASE.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
MEDIUM RANGE GUIDANCE IN FAIR AGREEMENT ON CARRYING SHORT WAVE
TROUGH AND WEAK COLD FRONT ACROSS WESTERN GREAT LAKES DURING THE
FIRST HALF OF NEXT WEEK. SOME TIMING DIFFERENCES WITH GEM AND GFS
SLIGHTLY FASTER THAN THE LATEST ECMWF. NEVER THE LESS...LEANING
TOWARD THREAT OF CONVECTION WITH SURGE OF WARM AIR ADVECTION MONDAY
NIGHT INTO EARLY TUESDAY WITH CHANCE RETURNING LATER TUESDAY AND
TUESDAY NIGHT ASSOCIATED WITH STRONGER LAYER FORCING WITH CDFNT AND
MID-LEVEL WAVE.
THEN SLOW MOVING UPPER LOW OVER SOUTH CENTRAL CANADA LINGERS TO THE
NORTH THROUGH THURSDAY NIGHT. DRIER...ZONAL FLOW TO THE SOUTH OF
THIS FEATURE SHOULD RESULT IN NEAR OR SLIGHTLY BELOW NORMAL TEMPS
THROUGH THE LATER PART OF THE EXTENDED PERIOD. CANADIAN UPPER LOW
CONTINUES TO WEAKEN LATE IN THE WEEK AND GETS NUDGED EAST FRIDAY AND
SATURDAY.
&&
.AVIATION /00Z TAFS/...
SURFACE COOL FRONT/DRY LINE SHIFTING SE OF THE AREA WITH DRIER AIR
BEING BROUGHT IN ON NW WINDS. MOST CU VFR THOUGH A FEW SITES MVFR.
EXPECT THIS TO DISSIPATE DIURNALLY. HRRR DOES SHOW THE NW IA COMPLEX
BRUSHING SW WI LATER THIS EVE BUT WILL LEAVE PRECIP MENTION OUT OF
TAF SITES. HIGH PRESSURE BUILDS IN TO DOMINATE FOR SATURDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
.CONFIDENCE...
TONIGHT AND SATURDAY...MEDIUM.
SATURDAY THROUGH SUNDAY...HIGH.
SUNDAY NIGHT AND MONDAY...LOW TO MEDIUM.
MONDAY NIGHT THROUGH WEDNESDAY...MEDIUM.
THURSDAY AND FRIDAY...MEDIUM TO HIGH.
$$
VERY SHORT TERM AND AVIATION/MARINE...PC
SHORT TERM/LONG TERM...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1200 PM CDT FRI AUG 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CDT FRI AUG 2 2013
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHS OVER THE PACIFIC NORTHWEST AS WELL AS FROM
HUDSON BAY INTO THE GREAT LAKES...WITH RIDGING IN-BETWEEN ALONG THE
LEE OF THE ROCKIES. THE FORECAST AREA REMAINS IN NORTHWEST FLOW EAST
OF THE RIDGING. WITHIN THIS FLOW...SHORTWAVES OF NOTE WERE OVER LAKE
WINNIPEG...NORTHERN WI AND SOUTHEAST WI. THE SOUTHEAST WI SHORTWAVE
IN CONJUNCTION WITH A SURGE OF WARM ADVECTION SEEN ON 850MB VAD WIND
PROFILE DATA HELPED BRING A BAND OF SCATTERED SHOWERS AND STORMS
ACROSS THE FORECAST AREA LAST EVENING...A FEW WHICH WERE STRONG TO
SEVERE. TO THE NORTH...A COLD POOL ACCOMPANYING THE NORTHERN WI
SHORTWAVE AS WELL AS MOISTURE SEEN ON THE 00Z INL SOUNDING BROUGHT
SHOWERS AND A FEW STORMS THROUGH NORTHERN WI OVERNIGHT. WARM
ADVECTION WELL SOUTH OF THIS SHORTWAVE AND SOME LINGERING WEAK
INSTABILITY / MUCAPE LESS THAN 500 J/KG /HAS HELPED PRODUCED SHOWERS
AND SOME STORMS SOUTH OF I-90 IN THE FORECAST AREA. SO FAR
EVERYTHING IS QUIET WITH THE LAKE WINNIPEG SHORTWAVE. ON
SATELLITE...MOSTLY CLEAR SKIES ENCOMPASSED MUCH OF THE EASTERN
DAKOTAS INTO MN...THANKS TO DRYING SEEN ON THE 00Z MPX... BIS AND
ABR SOUNDINGS. THIS DRYING IS ALSO BEHIND A SURFACE COLD FRONT WHICH
CAN BE SEEN ON MPX RADAR DROPPING THROUGH MINNEAPOLIS AT THIS TIME.
850MB TEMPS BEHIND THE COLD FRONT ARE NOT MUCH COOLER THAN THOSE
AHEAD OF IT...THOUGH...WITH READINGS GENERALLY 13-15C PER 00Z
SOUNDING DATA.
SYNOPTIC OVERVIEW...
THE NORTHWEST FLOW PATTERN CONTINUES TO PERSIST THROUGH THE SHORT
TERM PERIOD. THE SHORTWAVES OVER NORTHERN WI AS WELL AS OVER LAKE
WINNIPEG ARE PROGGED TO STAY OFF TO OUR NORTH AND EAST.
MEANWHILE...NUMEROUS WEAK SHORTWAVES ARE SUGGESTED TO COME OUT OF
THE PACIFIC NORTHWEST TROUGH AND DROP THROUGH THE FORECAST AREA
TONIGHT.
DETAILS...
THE COLD FRONT LURKING JUST OFF TO THE NORTHWEST AT 08Z LOOKS TO
PUSH THROUGH THE FORECAST AREA DURING THE MORNING HOURS. ONCE IT
PASSES...THE CONCERN FOR PRECIPITATION ENDS AS THE DRIER AIR OVER
THE DAKOTAS AND MN FLOWS IN. DESPITE THE SHORTWAVES CROSSING THE
FORECAST AREA TONIGHT...WHICH APPEAR LIKELY TO BRING SOME MID/HIGH
CLOUDS THROUGH...SOUNDINGS DEPICT PLENTY OF DRY AIR BELOW 700MB TO
PREVENT ANY PRECIPITATION. 02.00Z GFS/NAM/ECMWF/REGIONAL CANADIAN
ARE ALL DRY...FURTHER INCREASING CONFIDENCE FOR A DRY FORECAST
TONIGHT. 850MB TEMPS IN THE 12-14C RANGE PLUS A MIX OF SUN THROUGH
PASSING MID/HIGH CLOUDS SHOULD ALLOW TEMPERATURES TO CLIMB WELL INTO
THE 70S. A FEW LOW 80S ARE POSSIBLE. IT APPEARS THE MID AND HIGH
CLOUDS SHOULD GRADUALLY CLEAR OUT TONIGHT AND WITH LIGHT WINDS AND
DRIER AIR...SOME OF THE TYPICAL COLD SPOTS COULD DROP INTO THE LOW
50S. OTHERWISE...MID/UPPER 50S APPEAR LIKELY. SOME VALLEY FOG MAY
OCCUR...PARTICULARLY IN THE SMALLER TRIBUTARIES TO THE MISSISSIPPI
RIVER. THERE MAY BE TOO MUCH EVENING CLOUD COVER...AFTERNOON
DEWPOINT MIXING/DRYING TODAY AND LATE DIMINISHING IN WIND TO ALLOW
FOG IN THE MISSISSIPPI RIVER CHANNEL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CDT FRI AUG 2 2013
SYNOPTIC OVERVIEW...
02.00Z ECMWF/GFS/CANADIAN CONTINUE THE NORTHWEST FLOW PATTERN OVER
THE FORECAST AREA THROUGH THE WEEKEND AS TROUGHING REMAINS IN PLACE
OVER SOUTHEAST CANADA INTO THE GREAT LAKES. THERE ARE NOW TRENDS FOR
THE UPPER FLOW OVER THE NORTHERN TIER OF THE U.S. TO START TURNING
MORE ZONAL MONDAY AND TUESDAY...IN RESPONSE TO WHAT BASICALLY COULD
BE CONSIDERED A POLAR VORTEX DROPPING OUT OF HUDSON BAY INTO THE
LAKE WINNIPEG REGION. EVOLUTION AND TRACK OF THE POLAR VORTEX AFTER
TUESDAY IS A LITTLE MORE UNCERTAIN...WITH THE 02.00Z CANADIAN
CARVING OUT MUCH MORE OF A TROUGH ACROSS THE WESTERN GREAT LAKES
COMPARED TO THE 02.00Z ECMWF/GFS WHICH ARE FLATTER WITH THE FLOW.
DETAILS...
FOR THE WEEKEND...HIGH PRESSURE CURRENTLY CENTERED IN NORTHERN
SASKATCHEWAN LOOKS TO DROP SOUTHEAST INTO THE FORECAST AREA ON
SUNDAY...FOLLOWING THE NORTHWEST FLOW PATTERN ALOFT. DRY AIR
ACCOMPANYING THE SURFACE HIGH WILL BE ENOUGH TO KEEP THE WEEKEND
DRY. MAY SEE SOME DIURNAL CUMULUS GROWTH BUT OTHERWISE MOSTLY CLEAR
SKIES ARE LIKELY TO PREVAIL. 850MB TEMPS ARE PROGGED 10-12C ON
SATURDAY AND 8-11C ON SUNDAY...ABOUT 1-1.5 STANDARD DEVIATIONS ABOVE
NORMAL. STILL WITH THE SUN WE SHOULD BE ABLE TO HOLD HIGH TEMPS IN
THE 70S. SATURDAY NIGHT LIKELY TO BE COOL WITH HIGH PRESSURE AND DRY
AIR IN PLACE. LEANED TOWARDS THE COOLER END OF GUIDANCE WHICH ALLOWS
FOR 40S IN SOME OF THE TYPICAL COLD SPOTS OF WI. VALLEY FOG LIKELY
SATURDAY NIGHT IN THE TRIBUTARIES AND POSSIBLY THE MISSISSIPPI
CHANNEL TOO.
CONCERN FOR PRECIPITATION BEGINS TO INCREASE FOR MONDAY AND TUESDAY
WITH THE UPPER FLOW TURNING MORE ZONAL. 02.00Z ECMWF/GFS/CANADIAN
ALL SHOW THE SURFACE HIGH DRIFTING OFF TO THE EAST DURING THIS
PERIOD AS A COLD FRONT APPROACHES THE AREA FROM THE WEST. STILL
TIMING DIFFERENCES WITH THE FRONTAL PASSAGE...BUT CURRENT CONSENSUS
WOULD PUT IT COMING THROUGH SOMETIME LATE TUESDAY. 850MB MOISTURE
TRANSPORT STAYS WEST OF THE AREA SUNDAY NIGHT AND MONDAY...WHICH
SHOULD KEEP PRECIPITATION CHANCES OFF TO THE WEST. PERHAPS SOMETHING
COULD DROP INTO THE AREA ON MONDAY...PER 02.00Z GFS...BUT
CONFIDENCE IS LOW. BETTER SHOT FOR PRECIPITATION COMES MONDAY NIGHT
AS THE 850MB MOISTURE TRANSPORT AND HIGHER ELEVATED CAPE VALUES COME
INTO THE FORECAST AREA. PRECIPITATION CHANCES CONTINUE THROUGH
TUESDAY NIGHT WITH THE FRONTAL PASSAGE. THESE MAY NEED TO BE
INCREASED AS THE FRONTAL TIMING BECOMES MORE REFINED. WITH THE LOW
LEVEL WARM ADVECTION PATTERN IN PLACE MONDAY AND TUESDAY...850MB
TEMPS REBOUND TO 12-14C ON MONDAY AND PERHAPS AS HIGH AS 16-20C ON
TUESDAY. DEPENDING ON AMOUNT OF SUN ON TUESDAY...WE COULD SEE HIGH
TEMPS GO ABOVE NORMAL WITH READINGS IN THE MID TO UPPER 80S.
HOWEVER...GIVEN THE PRECIPITATION CONCERN...HAVE FOLLOWED THE
CONSENSUS HIGHS OF MID 70S ON MONDAY AND 75-80 ON TUESDAY.
FOR WEDNESDAY AND THURSDAY...ANOTHER SURGE OF DRIER AND COOLER AIR
APPEARS SLATED TO COME INTO THE AREA DURING THIS PERIOD...IN THE
WAKE OF TUESDAY/TUESDAY NIGHTS FRONTAL PASSAGE. STILL...WITH
CONCERNS ON FRONTAL TIMING AND BOTH THE 02.00Z ECMWF/CANADIAN
LINGERING SOME PRECIPITATION BACK EVEN BEHIND THE FRONT ON
WEDNESDAY...MAINTAINED 20-30 PERCENT CHANCES. ALSO KEPT SOME 20
PERCENT CHANCES NORTH OF I-90 ON THURSDAY WITH INDICATIONS OF COLDER
AIR ALOFT...BEING CLOSER TO THE TROUGHING UP TO THE NORTH. HIGHS ON
WEDNESDAY SHOULD STILL CLIMB INTO THE MID TO UPPER 70S GIVEN 12-14C
850MB TEMPS...BUT PERHAPS ONLY THE LOW TO MID 70S ON THURSDAY AS
SOME COOLER AIR FLOWS IN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1200 PM CDT FRI AUG 2 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. MID TO
HIGH LEVEL CLOUDS WILL OVERSPREAD THE AREA FROM THE WEST THIS
AFTERNOON THROUGH THIS EVENING...STREAMING OFF OF A SHOWER/STORM
COMPLEX TRACKING SOUTHEAST ACROSS WESTERN AND CENTRAL IOWA. PLAN
ON CEILINGS LOWERING TO AROUND 8KFT BY THIS EVENING. IF CLEARING
OCCURS AT KLSE SOME PATCHY FOG COULD DEVELOP ALONG THE MISSISSIPPI
RIVER VALLEY LATE TONIGHT AND PERSIST INTO EARLY SATURDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1118 AM CDT FRI AUG 2 2013
.AVIATION/18Z TAFS/...SURFACE COOL FRONT/DRY LINE MOVING THROUGH
SE WI. WINDS SHIFT SW TO NW WITH THE PASSAGE OF THIS FEATURE.
STILL SOME MVFR CIGS ASSOCIATED WITH THIS. EXPECTING THIS TO MIX
OUT AND RISE TO VFR LEVELS AS THE AFTN WEARS ON. LITTLE CONCERN
FOR ADDITIONAL DEVELOPMENT BEHIND THE FRONT AS DRY PUSH PRETTY
PRONOUNCED PER 12Z KMPX SOUNDING AND SURFACE ISODROSOTHERM
ANALYSIS. HRRR DOES SHOW THE SD/NW IA COMPLEX BRUSHING SW WI LATER
THIS AFTN AND EARLY THIS EVE BUT WILL LEAVE PRECIP MENTION OUT OF
TAF SITES. HIGH PRESSURE BUILDS IN TO DOMINATE FOR SATURDAY.
PC
&&
.PREV DISCUSSION... /ISSUED 343 AM CDT FRI AUG 2 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
LOW TO MID LEVEL WARM ADVECTION/FRONTOGENESIS PATTERN AHEAD OF
APPROACHING SFC TROUGH WILL SHIFT EAST AND SOUTH THROUGH THE
MORNING...WITH TSTORMS FOLLOWING THE SAME TREND. ONLY SCT
SHOWERS/TSTORMS EXPECTED AFTER 12Z OVER THE FAR SRN CWA. CHANCE POPS
WILL CONTINUE IN THE FAR SRN CWA THROUGHOUT THE DAY AS THE SFC
TROUGH AND CAPE STALLS THERE AND OVER NRN IL...AND A WEAK COLD FRONT
THEN APPROACHES FROM THE NORTH IN THE AFTERNOON. BELIEVE MAJORITY OF
NEW DEVELOPMENT THIS AFTERNOON WILL LIKELY BE IN NRN IL WITH THE
THUNDER THREAT DIMINISHED BY EARLY EVENING OVER FAR SRN WI.
OTHERWISE...DO EXPECT SOME SUNSHINE TODAY AFTER MORNING CONVECTION
WITH 925 MB TEMPS AROUND 20-21C SUGGESTING HIGH TEMPS WILL BE IN THE
LOWER 80S. LGT NLY WINDS AND WEAK COLD ADVECTION THEN EXPECTED FOR
TNT.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA SATURDAY...MOVING
OVERHEAD ON SUNDAY. EXPECT A PLEASANT WEEKEND...WITH PARTLY CLOUDY
SKIES AND HIGH TEMPERATURES JUST A TAD BELOW AVERAGE VALUES FOR
EARLY AUGUST. LEFT A SMALL CHANCE FOR SHOWERS AND STORMS WEST FOR
LATER SUNDAY NIGHT AS A WEAK SHORTWAVE APPROACHES.
MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM
COULD SEE A FEW SHOWERS/STORMS MONDAY AS THE SHORTWAVE SLIDES
THROUGH. BETTER CHANCE FOR PRECIP TUESDAY INTO EARLY WEDNESDAY AS A
STRONGER WAVE AND COLD FRONT PUSH THROUGH THE AREA.
KEPT SOME POPS THROUGH THE DAY WEDNESDAY AS MODELS DIFFER SOMEWHAT
ON TIMING OF THE FRONT. DESPITE MODEL DIFFERENCES...LOOKS DRY BY
EVENING AS HIGH PRESSURE BEGINS TO BUILD INTO THE AREA. SHOULD BE
DRY THEN THURSDAY UNDER THE HIGH.
NO BIG CHANGE IN TEMPERATURES IS EXPECTED NEXT WEEK THROUGH
THURSDAY...WITH HIGHS REMAINING NEAR TO A COUPLE DEGREES BELOW
NORMAL.
AVIATION/12Z TAFS/...PREVAILING BROKEN CLOUD COVER FROM 5-7 KFT
THIS MORNING AS WARM ADVECTION AND SCATTERED THUNDERSTORMS MOVE
ACROSS SRN WI. CIGS AND VSBYS WILL BE REDUCED IN THE TSTORMS. LESS
COVERAGE IN TSTORMS IS EXPECTED AFTER 12Z THIS MORNING ALTHOUGH
CHANCES OF SHOWERS AND TSTORMS WILL CONTINUE OVER FAR SRN
WI...INCLUDING KENW FOR MUCH OF THE DAY AS THE SFC TROUGH STALLS
THERE. VFR CONDITIONS WILL CONTINUE TO PREVAIL THROUGH THE AFTERNOON
WITH CUMULUS CONGESTUS AROUND 5 KFT. NLY WINDS AND WEAK COLD
ADVECTION TO DRY LOW LEVEL ATMOSPHERE TNT WILL VFR CONDITIONS
CONTINUING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
SATURDAY THROUGH THURSDAY...DDV